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   1/*
   2 * Copyright (c) Yann Collet, Facebook, Inc.
   3 * All rights reserved.
   4 *
   5 * This source code is licensed under both the BSD-style license (found in the
   6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
   7 * in the COPYING file in the root directory of this source tree).
   8 * You may select, at your option, one of the above-listed licenses.
   9 */
  10
  11/*-*************************************
  12*  Dependencies
  13***************************************/
  14#include "../common/zstd_deps.h"  /* INT_MAX, ZSTD_memset, ZSTD_memcpy */
  15#include "../common/mem.h"
  16#include "hist.h"           /* HIST_countFast_wksp */
  17#define FSE_STATIC_LINKING_ONLY   /* FSE_encodeSymbol */
  18#include "../common/fse.h"
  19#define HUF_STATIC_LINKING_ONLY
  20#include "../common/huf.h"
  21#include "zstd_compress_internal.h"
  22#include "zstd_compress_sequences.h"
  23#include "zstd_compress_literals.h"
  24#include "zstd_fast.h"
  25#include "zstd_double_fast.h"
  26#include "zstd_lazy.h"
  27#include "zstd_opt.h"
  28#include "zstd_ldm.h"
  29#include "zstd_compress_superblock.h"
  30
  31/* ***************************************************************
  32*  Tuning parameters
  33*****************************************************************/
  34/*!
  35 * COMPRESS_HEAPMODE :
  36 * Select how default decompression function ZSTD_compress() allocates its context,
  37 * on stack (0, default), or into heap (1).
  38 * Note that functions with explicit context such as ZSTD_compressCCtx() are unaffected.
  39 */
  40
  41/*!
  42 * ZSTD_HASHLOG3_MAX :
  43 * Maximum size of the hash table dedicated to find 3-bytes matches,
  44 * in log format, aka 17 => 1 << 17 == 128Ki positions.
  45 * This structure is only used in zstd_opt.
  46 * Since allocation is centralized for all strategies, it has to be known here.
  47 * The actual (selected) size of the hash table is then stored in ZSTD_matchState_t.hashLog3,
  48 * so that zstd_opt.c doesn't need to know about this constant.
  49 */
  50#ifndef ZSTD_HASHLOG3_MAX
  51#  define ZSTD_HASHLOG3_MAX 17
  52#endif
  53
  54/*-*************************************
  55*  Helper functions
  56***************************************/
  57/* ZSTD_compressBound()
  58 * Note that the result from this function is only compatible with the "normal"
  59 * full-block strategy.
  60 * When there are a lot of small blocks due to frequent flush in streaming mode
  61 * the overhead of headers can make the compressed data to be larger than the
  62 * return value of ZSTD_compressBound().
  63 */
  64size_t ZSTD_compressBound(size_t srcSize) {
  65    return ZSTD_COMPRESSBOUND(srcSize);
  66}
  67
  68
  69/*-*************************************
  70*  Context memory management
  71***************************************/
  72struct ZSTD_CDict_s {
  73    const void* dictContent;
  74    size_t dictContentSize;
  75    ZSTD_dictContentType_e dictContentType; /* The dictContentType the CDict was created with */
  76    U32* entropyWorkspace; /* entropy workspace of HUF_WORKSPACE_SIZE bytes */
  77    ZSTD_cwksp workspace;
  78    ZSTD_matchState_t matchState;
  79    ZSTD_compressedBlockState_t cBlockState;
  80    ZSTD_customMem customMem;
  81    U32 dictID;
  82    int compressionLevel; /* 0 indicates that advanced API was used to select CDict params */
  83    ZSTD_paramSwitch_e useRowMatchFinder; /* Indicates whether the CDict was created with params that would use
  84                                           * row-based matchfinder. Unless the cdict is reloaded, we will use
  85                                           * the same greedy/lazy matchfinder at compression time.
  86                                           */
  87};  /* typedef'd to ZSTD_CDict within "zstd.h" */
  88
  89ZSTD_CCtx* ZSTD_createCCtx(void)
  90{
  91    return ZSTD_createCCtx_advanced(ZSTD_defaultCMem);
  92}
  93
  94static void ZSTD_initCCtx(ZSTD_CCtx* cctx, ZSTD_customMem memManager)
  95{
  96    assert(cctx != NULL);
  97    ZSTD_memset(cctx, 0, sizeof(*cctx));
  98    cctx->customMem = memManager;
  99    cctx->bmi2 = ZSTD_cpuSupportsBmi2();
 100    {   size_t const err = ZSTD_CCtx_reset(cctx, ZSTD_reset_parameters);
 101        assert(!ZSTD_isError(err));
 102        (void)err;
 103    }
 104}
 105
 106ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem)
 107{
 108    ZSTD_STATIC_ASSERT(zcss_init==0);
 109    ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN==(0ULL - 1));
 110    if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL;
 111    {   ZSTD_CCtx* const cctx = (ZSTD_CCtx*)ZSTD_customMalloc(sizeof(ZSTD_CCtx), customMem);
 112        if (!cctx) return NULL;
 113        ZSTD_initCCtx(cctx, customMem);
 114        return cctx;
 115    }
 116}
 117
 118ZSTD_CCtx* ZSTD_initStaticCCtx(void* workspace, size_t workspaceSize)
 119{
 120    ZSTD_cwksp ws;
 121    ZSTD_CCtx* cctx;
 122    if (workspaceSize <= sizeof(ZSTD_CCtx)) return NULL;  /* minimum size */
 123    if ((size_t)workspace & 7) return NULL;  /* must be 8-aligned */
 124    ZSTD_cwksp_init(&ws, workspace, workspaceSize, ZSTD_cwksp_static_alloc);
 125
 126    cctx = (ZSTD_CCtx*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CCtx));
 127    if (cctx == NULL) return NULL;
 128
 129    ZSTD_memset(cctx, 0, sizeof(ZSTD_CCtx));
 130    ZSTD_cwksp_move(&cctx->workspace, &ws);
 131    cctx->staticSize = workspaceSize;
 132
 133    /* statically sized space. entropyWorkspace never moves (but prev/next block swap places) */
 134    if (!ZSTD_cwksp_check_available(&cctx->workspace, ENTROPY_WORKSPACE_SIZE + 2 * sizeof(ZSTD_compressedBlockState_t))) return NULL;
 135    cctx->blockState.prevCBlock = (ZSTD_compressedBlockState_t*)ZSTD_cwksp_reserve_object(&cctx->workspace, sizeof(ZSTD_compressedBlockState_t));
 136    cctx->blockState.nextCBlock = (ZSTD_compressedBlockState_t*)ZSTD_cwksp_reserve_object(&cctx->workspace, sizeof(ZSTD_compressedBlockState_t));
 137    cctx->entropyWorkspace = (U32*)ZSTD_cwksp_reserve_object(&cctx->workspace, ENTROPY_WORKSPACE_SIZE);
 138    cctx->bmi2 = ZSTD_cpuid_bmi2(ZSTD_cpuid());
 139    return cctx;
 140}
 141
 142/*
 143 * Clears and frees all of the dictionaries in the CCtx.
 144 */
 145static void ZSTD_clearAllDicts(ZSTD_CCtx* cctx)
 146{
 147    ZSTD_customFree(cctx->localDict.dictBuffer, cctx->customMem);
 148    ZSTD_freeCDict(cctx->localDict.cdict);
 149    ZSTD_memset(&cctx->localDict, 0, sizeof(cctx->localDict));
 150    ZSTD_memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));
 151    cctx->cdict = NULL;
 152}
 153
 154static size_t ZSTD_sizeof_localDict(ZSTD_localDict dict)
 155{
 156    size_t const bufferSize = dict.dictBuffer != NULL ? dict.dictSize : 0;
 157    size_t const cdictSize = ZSTD_sizeof_CDict(dict.cdict);
 158    return bufferSize + cdictSize;
 159}
 160
 161static void ZSTD_freeCCtxContent(ZSTD_CCtx* cctx)
 162{
 163    assert(cctx != NULL);
 164    assert(cctx->staticSize == 0);
 165    ZSTD_clearAllDicts(cctx);
 166    ZSTD_cwksp_free(&cctx->workspace, cctx->customMem);
 167}
 168
 169size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx)
 170{
 171    if (cctx==NULL) return 0;   /* support free on NULL */
 172    RETURN_ERROR_IF(cctx->staticSize, memory_allocation,
 173                    "not compatible with static CCtx");
 174    {
 175        int cctxInWorkspace = ZSTD_cwksp_owns_buffer(&cctx->workspace, cctx);
 176        ZSTD_freeCCtxContent(cctx);
 177        if (!cctxInWorkspace) {
 178            ZSTD_customFree(cctx, cctx->customMem);
 179        }
 180    }
 181    return 0;
 182}
 183
 184
 185static size_t ZSTD_sizeof_mtctx(const ZSTD_CCtx* cctx)
 186{
 187    (void)cctx;
 188    return 0;
 189}
 190
 191
 192size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx)
 193{
 194    if (cctx==NULL) return 0;   /* support sizeof on NULL */
 195    /* cctx may be in the workspace */
 196    return (cctx->workspace.workspace == cctx ? 0 : sizeof(*cctx))
 197           + ZSTD_cwksp_sizeof(&cctx->workspace)
 198           + ZSTD_sizeof_localDict(cctx->localDict)
 199           + ZSTD_sizeof_mtctx(cctx);
 200}
 201
 202size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs)
 203{
 204    return ZSTD_sizeof_CCtx(zcs);  /* same object */
 205}
 206
 207/* private API call, for dictBuilder only */
 208const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx) { return &(ctx->seqStore); }
 209
 210/* Returns true if the strategy supports using a row based matchfinder */
 211static int ZSTD_rowMatchFinderSupported(const ZSTD_strategy strategy) {
 212    return (strategy >= ZSTD_greedy && strategy <= ZSTD_lazy2);
 213}
 214
 215/* Returns true if the strategy and useRowMatchFinder mode indicate that we will use the row based matchfinder
 216 * for this compression.
 217 */
 218static int ZSTD_rowMatchFinderUsed(const ZSTD_strategy strategy, const ZSTD_paramSwitch_e mode) {
 219    assert(mode != ZSTD_ps_auto);
 220    return ZSTD_rowMatchFinderSupported(strategy) && (mode == ZSTD_ps_enable);
 221}
 222
 223/* Returns row matchfinder usage given an initial mode and cParams */
 224static ZSTD_paramSwitch_e ZSTD_resolveRowMatchFinderMode(ZSTD_paramSwitch_e mode,
 225                                                         const ZSTD_compressionParameters* const cParams) {
 226#if defined(ZSTD_ARCH_X86_SSE2) || defined(ZSTD_ARCH_ARM_NEON)
 227    int const kHasSIMD128 = 1;
 228#else
 229    int const kHasSIMD128 = 0;
 230#endif
 231    if (mode != ZSTD_ps_auto) return mode; /* if requested enabled, but no SIMD, we still will use row matchfinder */
 232    mode = ZSTD_ps_disable;
 233    if (!ZSTD_rowMatchFinderSupported(cParams->strategy)) return mode;
 234    if (kHasSIMD128) {
 235        if (cParams->windowLog > 14) mode = ZSTD_ps_enable;
 236    } else {
 237        if (cParams->windowLog > 17) mode = ZSTD_ps_enable;
 238    }
 239    return mode;
 240}
 241
 242/* Returns block splitter usage (generally speaking, when using slower/stronger compression modes) */
 243static ZSTD_paramSwitch_e ZSTD_resolveBlockSplitterMode(ZSTD_paramSwitch_e mode,
 244                                                        const ZSTD_compressionParameters* const cParams) {
 245    if (mode != ZSTD_ps_auto) return mode;
 246    return (cParams->strategy >= ZSTD_btopt && cParams->windowLog >= 17) ? ZSTD_ps_enable : ZSTD_ps_disable;
 247}
 248
 249/* Returns 1 if the arguments indicate that we should allocate a chainTable, 0 otherwise */
 250static int ZSTD_allocateChainTable(const ZSTD_strategy strategy,
 251                                   const ZSTD_paramSwitch_e useRowMatchFinder,
 252                                   const U32 forDDSDict) {
 253    assert(useRowMatchFinder != ZSTD_ps_auto);
 254    /* We always should allocate a chaintable if we are allocating a matchstate for a DDS dictionary matchstate.
 255     * We do not allocate a chaintable if we are using ZSTD_fast, or are using the row-based matchfinder.
 256     */
 257    return forDDSDict || ((strategy != ZSTD_fast) && !ZSTD_rowMatchFinderUsed(strategy, useRowMatchFinder));
 258}
 259
 260/* Returns 1 if compression parameters are such that we should
 261 * enable long distance matching (wlog >= 27, strategy >= btopt).
 262 * Returns 0 otherwise.
 263 */
 264static ZSTD_paramSwitch_e ZSTD_resolveEnableLdm(ZSTD_paramSwitch_e mode,
 265                                 const ZSTD_compressionParameters* const cParams) {
 266    if (mode != ZSTD_ps_auto) return mode;
 267    return (cParams->strategy >= ZSTD_btopt && cParams->windowLog >= 27) ? ZSTD_ps_enable : ZSTD_ps_disable;
 268}
 269
 270static ZSTD_CCtx_params ZSTD_makeCCtxParamsFromCParams(
 271        ZSTD_compressionParameters cParams)
 272{
 273    ZSTD_CCtx_params cctxParams;
 274    /* should not matter, as all cParams are presumed properly defined */
 275    ZSTD_CCtxParams_init(&cctxParams, ZSTD_CLEVEL_DEFAULT);
 276    cctxParams.cParams = cParams;
 277
 278    /* Adjust advanced params according to cParams */
 279    cctxParams.ldmParams.enableLdm = ZSTD_resolveEnableLdm(cctxParams.ldmParams.enableLdm, &cParams);
 280    if (cctxParams.ldmParams.enableLdm == ZSTD_ps_enable) {
 281        ZSTD_ldm_adjustParameters(&cctxParams.ldmParams, &cParams);
 282        assert(cctxParams.ldmParams.hashLog >= cctxParams.ldmParams.bucketSizeLog);
 283        assert(cctxParams.ldmParams.hashRateLog < 32);
 284    }
 285    cctxParams.useBlockSplitter = ZSTD_resolveBlockSplitterMode(cctxParams.useBlockSplitter, &cParams);
 286    cctxParams.useRowMatchFinder = ZSTD_resolveRowMatchFinderMode(cctxParams.useRowMatchFinder, &cParams);
 287    assert(!ZSTD_checkCParams(cParams));
 288    return cctxParams;
 289}
 290
 291static ZSTD_CCtx_params* ZSTD_createCCtxParams_advanced(
 292        ZSTD_customMem customMem)
 293{
 294    ZSTD_CCtx_params* params;
 295    if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL;
 296    params = (ZSTD_CCtx_params*)ZSTD_customCalloc(
 297            sizeof(ZSTD_CCtx_params), customMem);
 298    if (!params) { return NULL; }
 299    ZSTD_CCtxParams_init(params, ZSTD_CLEVEL_DEFAULT);
 300    params->customMem = customMem;
 301    return params;
 302}
 303
 304ZSTD_CCtx_params* ZSTD_createCCtxParams(void)
 305{
 306    return ZSTD_createCCtxParams_advanced(ZSTD_defaultCMem);
 307}
 308
 309size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params)
 310{
 311    if (params == NULL) { return 0; }
 312    ZSTD_customFree(params, params->customMem);
 313    return 0;
 314}
 315
 316size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params)
 317{
 318    return ZSTD_CCtxParams_init(params, ZSTD_CLEVEL_DEFAULT);
 319}
 320
 321size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel) {
 322    RETURN_ERROR_IF(!cctxParams, GENERIC, "NULL pointer!");
 323    ZSTD_memset(cctxParams, 0, sizeof(*cctxParams));
 324    cctxParams->compressionLevel = compressionLevel;
 325    cctxParams->fParams.contentSizeFlag = 1;
 326    return 0;
 327}
 328
 329#define ZSTD_NO_CLEVEL 0
 330
 331/*
 332 * Initializes the cctxParams from params and compressionLevel.
 333 * @param compressionLevel If params are derived from a compression level then that compression level, otherwise ZSTD_NO_CLEVEL.
 334 */
 335static void ZSTD_CCtxParams_init_internal(ZSTD_CCtx_params* cctxParams, ZSTD_parameters const* params, int compressionLevel)
 336{
 337    assert(!ZSTD_checkCParams(params->cParams));
 338    ZSTD_memset(cctxParams, 0, sizeof(*cctxParams));
 339    cctxParams->cParams = params->cParams;
 340    cctxParams->fParams = params->fParams;
 341    /* Should not matter, as all cParams are presumed properly defined.
 342     * But, set it for tracing anyway.
 343     */
 344    cctxParams->compressionLevel = compressionLevel;
 345    cctxParams->useRowMatchFinder = ZSTD_resolveRowMatchFinderMode(cctxParams->useRowMatchFinder, &params->cParams);
 346    cctxParams->useBlockSplitter = ZSTD_resolveBlockSplitterMode(cctxParams->useBlockSplitter, &params->cParams);
 347    cctxParams->ldmParams.enableLdm = ZSTD_resolveEnableLdm(cctxParams->ldmParams.enableLdm, &params->cParams);
 348    DEBUGLOG(4, "ZSTD_CCtxParams_init_internal: useRowMatchFinder=%d, useBlockSplitter=%d ldm=%d",
 349                cctxParams->useRowMatchFinder, cctxParams->useBlockSplitter, cctxParams->ldmParams.enableLdm);
 350}
 351
 352size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params)
 353{
 354    RETURN_ERROR_IF(!cctxParams, GENERIC, "NULL pointer!");
 355    FORWARD_IF_ERROR( ZSTD_checkCParams(params.cParams) , "");
 356    ZSTD_CCtxParams_init_internal(cctxParams, &params, ZSTD_NO_CLEVEL);
 357    return 0;
 358}
 359
 360/*
 361 * Sets cctxParams' cParams and fParams from params, but otherwise leaves them alone.
 362 * @param param Validated zstd parameters.
 363 */
 364static void ZSTD_CCtxParams_setZstdParams(
 365        ZSTD_CCtx_params* cctxParams, const ZSTD_parameters* params)
 366{
 367    assert(!ZSTD_checkCParams(params->cParams));
 368    cctxParams->cParams = params->cParams;
 369    cctxParams->fParams = params->fParams;
 370    /* Should not matter, as all cParams are presumed properly defined.
 371     * But, set it for tracing anyway.
 372     */
 373    cctxParams->compressionLevel = ZSTD_NO_CLEVEL;
 374}
 375
 376ZSTD_bounds ZSTD_cParam_getBounds(ZSTD_cParameter param)
 377{
 378    ZSTD_bounds bounds = { 0, 0, 0 };
 379
 380    switch(param)
 381    {
 382    case ZSTD_c_compressionLevel:
 383        bounds.lowerBound = ZSTD_minCLevel();
 384        bounds.upperBound = ZSTD_maxCLevel();
 385        return bounds;
 386
 387    case ZSTD_c_windowLog:
 388        bounds.lowerBound = ZSTD_WINDOWLOG_MIN;
 389        bounds.upperBound = ZSTD_WINDOWLOG_MAX;
 390        return bounds;
 391
 392    case ZSTD_c_hashLog:
 393        bounds.lowerBound = ZSTD_HASHLOG_MIN;
 394        bounds.upperBound = ZSTD_HASHLOG_MAX;
 395        return bounds;
 396
 397    case ZSTD_c_chainLog:
 398        bounds.lowerBound = ZSTD_CHAINLOG_MIN;
 399        bounds.upperBound = ZSTD_CHAINLOG_MAX;
 400        return bounds;
 401
 402    case ZSTD_c_searchLog:
 403        bounds.lowerBound = ZSTD_SEARCHLOG_MIN;
 404        bounds.upperBound = ZSTD_SEARCHLOG_MAX;
 405        return bounds;
 406
 407    case ZSTD_c_minMatch:
 408        bounds.lowerBound = ZSTD_MINMATCH_MIN;
 409        bounds.upperBound = ZSTD_MINMATCH_MAX;
 410        return bounds;
 411
 412    case ZSTD_c_targetLength:
 413        bounds.lowerBound = ZSTD_TARGETLENGTH_MIN;
 414        bounds.upperBound = ZSTD_TARGETLENGTH_MAX;
 415        return bounds;
 416
 417    case ZSTD_c_strategy:
 418        bounds.lowerBound = ZSTD_STRATEGY_MIN;
 419        bounds.upperBound = ZSTD_STRATEGY_MAX;
 420        return bounds;
 421
 422    case ZSTD_c_contentSizeFlag:
 423        bounds.lowerBound = 0;
 424        bounds.upperBound = 1;
 425        return bounds;
 426
 427    case ZSTD_c_checksumFlag:
 428        bounds.lowerBound = 0;
 429        bounds.upperBound = 1;
 430        return bounds;
 431
 432    case ZSTD_c_dictIDFlag:
 433        bounds.lowerBound = 0;
 434        bounds.upperBound = 1;
 435        return bounds;
 436
 437    case ZSTD_c_nbWorkers:
 438        bounds.lowerBound = 0;
 439        bounds.upperBound = 0;
 440        return bounds;
 441
 442    case ZSTD_c_jobSize:
 443        bounds.lowerBound = 0;
 444        bounds.upperBound = 0;
 445        return bounds;
 446
 447    case ZSTD_c_overlapLog:
 448        bounds.lowerBound = 0;
 449        bounds.upperBound = 0;
 450        return bounds;
 451
 452    case ZSTD_c_enableDedicatedDictSearch:
 453        bounds.lowerBound = 0;
 454        bounds.upperBound = 1;
 455        return bounds;
 456
 457    case ZSTD_c_enableLongDistanceMatching:
 458        bounds.lowerBound = 0;
 459        bounds.upperBound = 1;
 460        return bounds;
 461
 462    case ZSTD_c_ldmHashLog:
 463        bounds.lowerBound = ZSTD_LDM_HASHLOG_MIN;
 464        bounds.upperBound = ZSTD_LDM_HASHLOG_MAX;
 465        return bounds;
 466
 467    case ZSTD_c_ldmMinMatch:
 468        bounds.lowerBound = ZSTD_LDM_MINMATCH_MIN;
 469        bounds.upperBound = ZSTD_LDM_MINMATCH_MAX;
 470        return bounds;
 471
 472    case ZSTD_c_ldmBucketSizeLog:
 473        bounds.lowerBound = ZSTD_LDM_BUCKETSIZELOG_MIN;
 474        bounds.upperBound = ZSTD_LDM_BUCKETSIZELOG_MAX;
 475        return bounds;
 476
 477    case ZSTD_c_ldmHashRateLog:
 478        bounds.lowerBound = ZSTD_LDM_HASHRATELOG_MIN;
 479        bounds.upperBound = ZSTD_LDM_HASHRATELOG_MAX;
 480        return bounds;
 481
 482    /* experimental parameters */
 483    case ZSTD_c_rsyncable:
 484        bounds.lowerBound = 0;
 485        bounds.upperBound = 1;
 486        return bounds;
 487
 488    case ZSTD_c_forceMaxWindow :
 489        bounds.lowerBound = 0;
 490        bounds.upperBound = 1;
 491        return bounds;
 492
 493    case ZSTD_c_format:
 494        ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
 495        bounds.lowerBound = ZSTD_f_zstd1;
 496        bounds.upperBound = ZSTD_f_zstd1_magicless;   /* note : how to ensure at compile time that this is the highest value enum ? */
 497        return bounds;
 498
 499    case ZSTD_c_forceAttachDict:
 500        ZSTD_STATIC_ASSERT(ZSTD_dictDefaultAttach < ZSTD_dictForceLoad);
 501        bounds.lowerBound = ZSTD_dictDefaultAttach;
 502        bounds.upperBound = ZSTD_dictForceLoad;       /* note : how to ensure at compile time that this is the highest value enum ? */
 503        return bounds;
 504
 505    case ZSTD_c_literalCompressionMode:
 506        ZSTD_STATIC_ASSERT(ZSTD_ps_auto < ZSTD_ps_enable && ZSTD_ps_enable < ZSTD_ps_disable);
 507        bounds.lowerBound = (int)ZSTD_ps_auto;
 508        bounds.upperBound = (int)ZSTD_ps_disable;
 509        return bounds;
 510
 511    case ZSTD_c_targetCBlockSize:
 512        bounds.lowerBound = ZSTD_TARGETCBLOCKSIZE_MIN;
 513        bounds.upperBound = ZSTD_TARGETCBLOCKSIZE_MAX;
 514        return bounds;
 515
 516    case ZSTD_c_srcSizeHint:
 517        bounds.lowerBound = ZSTD_SRCSIZEHINT_MIN;
 518        bounds.upperBound = ZSTD_SRCSIZEHINT_MAX;
 519        return bounds;
 520
 521    case ZSTD_c_stableInBuffer:
 522    case ZSTD_c_stableOutBuffer:
 523        bounds.lowerBound = (int)ZSTD_bm_buffered;
 524        bounds.upperBound = (int)ZSTD_bm_stable;
 525        return bounds;
 526
 527    case ZSTD_c_blockDelimiters:
 528        bounds.lowerBound = (int)ZSTD_sf_noBlockDelimiters;
 529        bounds.upperBound = (int)ZSTD_sf_explicitBlockDelimiters;
 530        return bounds;
 531
 532    case ZSTD_c_validateSequences:
 533        bounds.lowerBound = 0;
 534        bounds.upperBound = 1;
 535        return bounds;
 536
 537    case ZSTD_c_useBlockSplitter:
 538        bounds.lowerBound = (int)ZSTD_ps_auto;
 539        bounds.upperBound = (int)ZSTD_ps_disable;
 540        return bounds;
 541
 542    case ZSTD_c_useRowMatchFinder:
 543        bounds.lowerBound = (int)ZSTD_ps_auto;
 544        bounds.upperBound = (int)ZSTD_ps_disable;
 545        return bounds;
 546
 547    case ZSTD_c_deterministicRefPrefix:
 548        bounds.lowerBound = 0;
 549        bounds.upperBound = 1;
 550        return bounds;
 551
 552    default:
 553        bounds.error = ERROR(parameter_unsupported);
 554        return bounds;
 555    }
 556}
 557
 558/* ZSTD_cParam_clampBounds:
 559 * Clamps the value into the bounded range.
 560 */
 561static size_t ZSTD_cParam_clampBounds(ZSTD_cParameter cParam, int* value)
 562{
 563    ZSTD_bounds const bounds = ZSTD_cParam_getBounds(cParam);
 564    if (ZSTD_isError(bounds.error)) return bounds.error;
 565    if (*value < bounds.lowerBound) *value = bounds.lowerBound;
 566    if (*value > bounds.upperBound) *value = bounds.upperBound;
 567    return 0;
 568}
 569
 570#define BOUNDCHECK(cParam, val) { \
 571    RETURN_ERROR_IF(!ZSTD_cParam_withinBounds(cParam,val), \
 572                    parameter_outOfBound, "Param out of bounds"); \
 573}
 574
 575
 576static int ZSTD_isUpdateAuthorized(ZSTD_cParameter param)
 577{
 578    switch(param)
 579    {
 580    case ZSTD_c_compressionLevel:
 581    case ZSTD_c_hashLog:
 582    case ZSTD_c_chainLog:
 583    case ZSTD_c_searchLog:
 584    case ZSTD_c_minMatch:
 585    case ZSTD_c_targetLength:
 586    case ZSTD_c_strategy:
 587        return 1;
 588
 589    case ZSTD_c_format:
 590    case ZSTD_c_windowLog:
 591    case ZSTD_c_contentSizeFlag:
 592    case ZSTD_c_checksumFlag:
 593    case ZSTD_c_dictIDFlag:
 594    case ZSTD_c_forceMaxWindow :
 595    case ZSTD_c_nbWorkers:
 596    case ZSTD_c_jobSize:
 597    case ZSTD_c_overlapLog:
 598    case ZSTD_c_rsyncable:
 599    case ZSTD_c_enableDedicatedDictSearch:
 600    case ZSTD_c_enableLongDistanceMatching:
 601    case ZSTD_c_ldmHashLog:
 602    case ZSTD_c_ldmMinMatch:
 603    case ZSTD_c_ldmBucketSizeLog:
 604    case ZSTD_c_ldmHashRateLog:
 605    case ZSTD_c_forceAttachDict:
 606    case ZSTD_c_literalCompressionMode:
 607    case ZSTD_c_targetCBlockSize:
 608    case ZSTD_c_srcSizeHint:
 609    case ZSTD_c_stableInBuffer:
 610    case ZSTD_c_stableOutBuffer:
 611    case ZSTD_c_blockDelimiters:
 612    case ZSTD_c_validateSequences:
 613    case ZSTD_c_useBlockSplitter:
 614    case ZSTD_c_useRowMatchFinder:
 615    case ZSTD_c_deterministicRefPrefix:
 616    default:
 617        return 0;
 618    }
 619}
 620
 621size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int value)
 622{
 623    DEBUGLOG(4, "ZSTD_CCtx_setParameter (%i, %i)", (int)param, value);
 624    if (cctx->streamStage != zcss_init) {
 625        if (ZSTD_isUpdateAuthorized(param)) {
 626            cctx->cParamsChanged = 1;
 627        } else {
 628            RETURN_ERROR(stage_wrong, "can only set params in ctx init stage");
 629    }   }
 630
 631    switch(param)
 632    {
 633    case ZSTD_c_nbWorkers:
 634        RETURN_ERROR_IF((value!=0) && cctx->staticSize, parameter_unsupported,
 635                        "MT not compatible with static alloc");
 636        break;
 637
 638    case ZSTD_c_compressionLevel:
 639    case ZSTD_c_windowLog:
 640    case ZSTD_c_hashLog:
 641    case ZSTD_c_chainLog:
 642    case ZSTD_c_searchLog:
 643    case ZSTD_c_minMatch:
 644    case ZSTD_c_targetLength:
 645    case ZSTD_c_strategy:
 646    case ZSTD_c_ldmHashRateLog:
 647    case ZSTD_c_format:
 648    case ZSTD_c_contentSizeFlag:
 649    case ZSTD_c_checksumFlag:
 650    case ZSTD_c_dictIDFlag:
 651    case ZSTD_c_forceMaxWindow:
 652    case ZSTD_c_forceAttachDict:
 653    case ZSTD_c_literalCompressionMode:
 654    case ZSTD_c_jobSize:
 655    case ZSTD_c_overlapLog:
 656    case ZSTD_c_rsyncable:
 657    case ZSTD_c_enableDedicatedDictSearch:
 658    case ZSTD_c_enableLongDistanceMatching:
 659    case ZSTD_c_ldmHashLog:
 660    case ZSTD_c_ldmMinMatch:
 661    case ZSTD_c_ldmBucketSizeLog:
 662    case ZSTD_c_targetCBlockSize:
 663    case ZSTD_c_srcSizeHint:
 664    case ZSTD_c_stableInBuffer:
 665    case ZSTD_c_stableOutBuffer:
 666    case ZSTD_c_blockDelimiters:
 667    case ZSTD_c_validateSequences:
 668    case ZSTD_c_useBlockSplitter:
 669    case ZSTD_c_useRowMatchFinder:
 670    case ZSTD_c_deterministicRefPrefix:
 671        break;
 672
 673    default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
 674    }
 675    return ZSTD_CCtxParams_setParameter(&cctx->requestedParams, param, value);
 676}
 677
 678size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* CCtxParams,
 679                                    ZSTD_cParameter param, int value)
 680{
 681    DEBUGLOG(4, "ZSTD_CCtxParams_setParameter (%i, %i)", (int)param, value);
 682    switch(param)
 683    {
 684    case ZSTD_c_format :
 685        BOUNDCHECK(ZSTD_c_format, value);
 686        CCtxParams->format = (ZSTD_format_e)value;
 687        return (size_t)CCtxParams->format;
 688
 689    case ZSTD_c_compressionLevel : {
 690        FORWARD_IF_ERROR(ZSTD_cParam_clampBounds(param, &value), "");
 691        if (value == 0)
 692            CCtxParams->compressionLevel = ZSTD_CLEVEL_DEFAULT; /* 0 == default */
 693        else
 694            CCtxParams->compressionLevel = value;
 695        if (CCtxParams->compressionLevel >= 0) return (size_t)CCtxParams->compressionLevel;
 696        return 0;  /* return type (size_t) cannot represent negative values */
 697    }
 698
 699    case ZSTD_c_windowLog :
 700        if (value!=0)   /* 0 => use default */
 701            BOUNDCHECK(ZSTD_c_windowLog, value);
 702        CCtxParams->cParams.windowLog = (U32)value;
 703        return CCtxParams->cParams.windowLog;
 704
 705    case ZSTD_c_hashLog :
 706        if (value!=0)   /* 0 => use default */
 707            BOUNDCHECK(ZSTD_c_hashLog, value);
 708        CCtxParams->cParams.hashLog = (U32)value;
 709        return CCtxParams->cParams.hashLog;
 710
 711    case ZSTD_c_chainLog :
 712        if (value!=0)   /* 0 => use default */
 713            BOUNDCHECK(ZSTD_c_chainLog, value);
 714        CCtxParams->cParams.chainLog = (U32)value;
 715        return CCtxParams->cParams.chainLog;
 716
 717    case ZSTD_c_searchLog :
 718        if (value!=0)   /* 0 => use default */
 719            BOUNDCHECK(ZSTD_c_searchLog, value);
 720        CCtxParams->cParams.searchLog = (U32)value;
 721        return (size_t)value;
 722
 723    case ZSTD_c_minMatch :
 724        if (value!=0)   /* 0 => use default */
 725            BOUNDCHECK(ZSTD_c_minMatch, value);
 726        CCtxParams->cParams.minMatch = value;
 727        return CCtxParams->cParams.minMatch;
 728
 729    case ZSTD_c_targetLength :
 730        BOUNDCHECK(ZSTD_c_targetLength, value);
 731        CCtxParams->cParams.targetLength = value;
 732        return CCtxParams->cParams.targetLength;
 733
 734    case ZSTD_c_strategy :
 735        if (value!=0)   /* 0 => use default */
 736            BOUNDCHECK(ZSTD_c_strategy, value);
 737        CCtxParams->cParams.strategy = (ZSTD_strategy)value;
 738        return (size_t)CCtxParams->cParams.strategy;
 739
 740    case ZSTD_c_contentSizeFlag :
 741        /* Content size written in frame header _when known_ (default:1) */
 742        DEBUGLOG(4, "set content size flag = %u", (value!=0));
 743        CCtxParams->fParams.contentSizeFlag = value != 0;
 744        return CCtxParams->fParams.contentSizeFlag;
 745
 746    case ZSTD_c_checksumFlag :
 747        /* A 32-bits content checksum will be calculated and written at end of frame (default:0) */
 748        CCtxParams->fParams.checksumFlag = value != 0;
 749        return CCtxParams->fParams.checksumFlag;
 750
 751    case ZSTD_c_dictIDFlag : /* When applicable, dictionary's dictID is provided in frame header (default:1) */
 752        DEBUGLOG(4, "set dictIDFlag = %u", (value!=0));
 753        CCtxParams->fParams.noDictIDFlag = !value;
 754        return !CCtxParams->fParams.noDictIDFlag;
 755
 756    case ZSTD_c_forceMaxWindow :
 757        CCtxParams->forceWindow = (value != 0);
 758        return CCtxParams->forceWindow;
 759
 760    case ZSTD_c_forceAttachDict : {
 761        const ZSTD_dictAttachPref_e pref = (ZSTD_dictAttachPref_e)value;
 762        BOUNDCHECK(ZSTD_c_forceAttachDict, pref);
 763        CCtxParams->attachDictPref = pref;
 764        return CCtxParams->attachDictPref;
 765    }
 766
 767    case ZSTD_c_literalCompressionMode : {
 768        const ZSTD_paramSwitch_e lcm = (ZSTD_paramSwitch_e)value;
 769        BOUNDCHECK(ZSTD_c_literalCompressionMode, lcm);
 770        CCtxParams->literalCompressionMode = lcm;
 771        return CCtxParams->literalCompressionMode;
 772    }
 773
 774    case ZSTD_c_nbWorkers :
 775        RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
 776        return 0;
 777
 778    case ZSTD_c_jobSize :
 779        RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
 780        return 0;
 781
 782    case ZSTD_c_overlapLog :
 783        RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
 784        return 0;
 785
 786    case ZSTD_c_rsyncable :
 787        RETURN_ERROR_IF(value!=0, parameter_unsupported, "not compiled with multithreading");
 788        return 0;
 789
 790    case ZSTD_c_enableDedicatedDictSearch :
 791        CCtxParams->enableDedicatedDictSearch = (value!=0);
 792        return CCtxParams->enableDedicatedDictSearch;
 793
 794    case ZSTD_c_enableLongDistanceMatching :
 795        CCtxParams->ldmParams.enableLdm = (ZSTD_paramSwitch_e)value;
 796        return CCtxParams->ldmParams.enableLdm;
 797
 798    case ZSTD_c_ldmHashLog :
 799        if (value!=0)   /* 0 ==> auto */
 800            BOUNDCHECK(ZSTD_c_ldmHashLog, value);
 801        CCtxParams->ldmParams.hashLog = value;
 802        return CCtxParams->ldmParams.hashLog;
 803
 804    case ZSTD_c_ldmMinMatch :
 805        if (value!=0)   /* 0 ==> default */
 806            BOUNDCHECK(ZSTD_c_ldmMinMatch, value);
 807        CCtxParams->ldmParams.minMatchLength = value;
 808        return CCtxParams->ldmParams.minMatchLength;
 809
 810    case ZSTD_c_ldmBucketSizeLog :
 811        if (value!=0)   /* 0 ==> default */
 812            BOUNDCHECK(ZSTD_c_ldmBucketSizeLog, value);
 813        CCtxParams->ldmParams.bucketSizeLog = value;
 814        return CCtxParams->ldmParams.bucketSizeLog;
 815
 816    case ZSTD_c_ldmHashRateLog :
 817        if (value!=0)   /* 0 ==> default */
 818            BOUNDCHECK(ZSTD_c_ldmHashRateLog, value);
 819        CCtxParams->ldmParams.hashRateLog = value;
 820        return CCtxParams->ldmParams.hashRateLog;
 821
 822    case ZSTD_c_targetCBlockSize :
 823        if (value!=0)   /* 0 ==> default */
 824            BOUNDCHECK(ZSTD_c_targetCBlockSize, value);
 825        CCtxParams->targetCBlockSize = value;
 826        return CCtxParams->targetCBlockSize;
 827
 828    case ZSTD_c_srcSizeHint :
 829        if (value!=0)    /* 0 ==> default */
 830            BOUNDCHECK(ZSTD_c_srcSizeHint, value);
 831        CCtxParams->srcSizeHint = value;
 832        return CCtxParams->srcSizeHint;
 833
 834    case ZSTD_c_stableInBuffer:
 835        BOUNDCHECK(ZSTD_c_stableInBuffer, value);
 836        CCtxParams->inBufferMode = (ZSTD_bufferMode_e)value;
 837        return CCtxParams->inBufferMode;
 838
 839    case ZSTD_c_stableOutBuffer:
 840        BOUNDCHECK(ZSTD_c_stableOutBuffer, value);
 841        CCtxParams->outBufferMode = (ZSTD_bufferMode_e)value;
 842        return CCtxParams->outBufferMode;
 843
 844    case ZSTD_c_blockDelimiters:
 845        BOUNDCHECK(ZSTD_c_blockDelimiters, value);
 846        CCtxParams->blockDelimiters = (ZSTD_sequenceFormat_e)value;
 847        return CCtxParams->blockDelimiters;
 848
 849    case ZSTD_c_validateSequences:
 850        BOUNDCHECK(ZSTD_c_validateSequences, value);
 851        CCtxParams->validateSequences = value;
 852        return CCtxParams->validateSequences;
 853
 854    case ZSTD_c_useBlockSplitter:
 855        BOUNDCHECK(ZSTD_c_useBlockSplitter, value);
 856        CCtxParams->useBlockSplitter = (ZSTD_paramSwitch_e)value;
 857        return CCtxParams->useBlockSplitter;
 858
 859    case ZSTD_c_useRowMatchFinder:
 860        BOUNDCHECK(ZSTD_c_useRowMatchFinder, value);
 861        CCtxParams->useRowMatchFinder = (ZSTD_paramSwitch_e)value;
 862        return CCtxParams->useRowMatchFinder;
 863
 864    case ZSTD_c_deterministicRefPrefix:
 865        BOUNDCHECK(ZSTD_c_deterministicRefPrefix, value);
 866        CCtxParams->deterministicRefPrefix = !!value;
 867        return CCtxParams->deterministicRefPrefix;
 868
 869    default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
 870    }
 871}
 872
 873size_t ZSTD_CCtx_getParameter(ZSTD_CCtx const* cctx, ZSTD_cParameter param, int* value)
 874{
 875    return ZSTD_CCtxParams_getParameter(&cctx->requestedParams, param, value);
 876}
 877
 878size_t ZSTD_CCtxParams_getParameter(
 879        ZSTD_CCtx_params const* CCtxParams, ZSTD_cParameter param, int* value)
 880{
 881    switch(param)
 882    {
 883    case ZSTD_c_format :
 884        *value = CCtxParams->format;
 885        break;
 886    case ZSTD_c_compressionLevel :
 887        *value = CCtxParams->compressionLevel;
 888        break;
 889    case ZSTD_c_windowLog :
 890        *value = (int)CCtxParams->cParams.windowLog;
 891        break;
 892    case ZSTD_c_hashLog :
 893        *value = (int)CCtxParams->cParams.hashLog;
 894        break;
 895    case ZSTD_c_chainLog :
 896        *value = (int)CCtxParams->cParams.chainLog;
 897        break;
 898    case ZSTD_c_searchLog :
 899        *value = CCtxParams->cParams.searchLog;
 900        break;
 901    case ZSTD_c_minMatch :
 902        *value = CCtxParams->cParams.minMatch;
 903        break;
 904    case ZSTD_c_targetLength :
 905        *value = CCtxParams->cParams.targetLength;
 906        break;
 907    case ZSTD_c_strategy :
 908        *value = (unsigned)CCtxParams->cParams.strategy;
 909        break;
 910    case ZSTD_c_contentSizeFlag :
 911        *value = CCtxParams->fParams.contentSizeFlag;
 912        break;
 913    case ZSTD_c_checksumFlag :
 914        *value = CCtxParams->fParams.checksumFlag;
 915        break;
 916    case ZSTD_c_dictIDFlag :
 917        *value = !CCtxParams->fParams.noDictIDFlag;
 918        break;
 919    case ZSTD_c_forceMaxWindow :
 920        *value = CCtxParams->forceWindow;
 921        break;
 922    case ZSTD_c_forceAttachDict :
 923        *value = CCtxParams->attachDictPref;
 924        break;
 925    case ZSTD_c_literalCompressionMode :
 926        *value = CCtxParams->literalCompressionMode;
 927        break;
 928    case ZSTD_c_nbWorkers :
 929        assert(CCtxParams->nbWorkers == 0);
 930        *value = CCtxParams->nbWorkers;
 931        break;
 932    case ZSTD_c_jobSize :
 933        RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
 934    case ZSTD_c_overlapLog :
 935        RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
 936    case ZSTD_c_rsyncable :
 937        RETURN_ERROR(parameter_unsupported, "not compiled with multithreading");
 938    case ZSTD_c_enableDedicatedDictSearch :
 939        *value = CCtxParams->enableDedicatedDictSearch;
 940        break;
 941    case ZSTD_c_enableLongDistanceMatching :
 942        *value = CCtxParams->ldmParams.enableLdm;
 943        break;
 944    case ZSTD_c_ldmHashLog :
 945        *value = CCtxParams->ldmParams.hashLog;
 946        break;
 947    case ZSTD_c_ldmMinMatch :
 948        *value = CCtxParams->ldmParams.minMatchLength;
 949        break;
 950    case ZSTD_c_ldmBucketSizeLog :
 951        *value = CCtxParams->ldmParams.bucketSizeLog;
 952        break;
 953    case ZSTD_c_ldmHashRateLog :
 954        *value = CCtxParams->ldmParams.hashRateLog;
 955        break;
 956    case ZSTD_c_targetCBlockSize :
 957        *value = (int)CCtxParams->targetCBlockSize;
 958        break;
 959    case ZSTD_c_srcSizeHint :
 960        *value = (int)CCtxParams->srcSizeHint;
 961        break;
 962    case ZSTD_c_stableInBuffer :
 963        *value = (int)CCtxParams->inBufferMode;
 964        break;
 965    case ZSTD_c_stableOutBuffer :
 966        *value = (int)CCtxParams->outBufferMode;
 967        break;
 968    case ZSTD_c_blockDelimiters :
 969        *value = (int)CCtxParams->blockDelimiters;
 970        break;
 971    case ZSTD_c_validateSequences :
 972        *value = (int)CCtxParams->validateSequences;
 973        break;
 974    case ZSTD_c_useBlockSplitter :
 975        *value = (int)CCtxParams->useBlockSplitter;
 976        break;
 977    case ZSTD_c_useRowMatchFinder :
 978        *value = (int)CCtxParams->useRowMatchFinder;
 979        break;
 980    case ZSTD_c_deterministicRefPrefix:
 981        *value = (int)CCtxParams->deterministicRefPrefix;
 982        break;
 983    default: RETURN_ERROR(parameter_unsupported, "unknown parameter");
 984    }
 985    return 0;
 986}
 987
 988/* ZSTD_CCtx_setParametersUsingCCtxParams() :
 989 *  just applies `params` into `cctx`
 990 *  no action is performed, parameters are merely stored.
 991 *  If ZSTDMT is enabled, parameters are pushed to cctx->mtctx.
 992 *    This is possible even if a compression is ongoing.
 993 *    In which case, new parameters will be applied on the fly, starting with next compression job.
 994 */
 995size_t ZSTD_CCtx_setParametersUsingCCtxParams(
 996        ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params)
 997{
 998    DEBUGLOG(4, "ZSTD_CCtx_setParametersUsingCCtxParams");
 999    RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong,
1000                    "The context is in the wrong stage!");
1001    RETURN_ERROR_IF(cctx->cdict, stage_wrong,
1002                    "Can't override parameters with cdict attached (some must "
1003                    "be inherited from the cdict).");
1004
1005    cctx->requestedParams = *params;
1006    return 0;
1007}
1008
1009size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize)
1010{
1011    DEBUGLOG(4, "ZSTD_CCtx_setPledgedSrcSize to %u bytes", (U32)pledgedSrcSize);
1012    RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong,
1013                    "Can't set pledgedSrcSize when not in init stage.");
1014    cctx->pledgedSrcSizePlusOne = pledgedSrcSize+1;
1015    return 0;
1016}
1017
1018static ZSTD_compressionParameters ZSTD_dedicatedDictSearch_getCParams(
1019        int const compressionLevel,
1020        size_t const dictSize);
1021static int ZSTD_dedicatedDictSearch_isSupported(
1022        const ZSTD_compressionParameters* cParams);
1023static void ZSTD_dedicatedDictSearch_revertCParams(
1024        ZSTD_compressionParameters* cParams);
1025
1026/*
1027 * Initializes the local dict using the requested parameters.
1028 * NOTE: This does not use the pledged src size, because it may be used for more
1029 * than one compression.
1030 */
1031static size_t ZSTD_initLocalDict(ZSTD_CCtx* cctx)
1032{
1033    ZSTD_localDict* const dl = &cctx->localDict;
1034    if (dl->dict == NULL) {
1035        /* No local dictionary. */
1036        assert(dl->dictBuffer == NULL);
1037        assert(dl->cdict == NULL);
1038        assert(dl->dictSize == 0);
1039        return 0;
1040    }
1041    if (dl->cdict != NULL) {
1042        assert(cctx->cdict == dl->cdict);
1043        /* Local dictionary already initialized. */
1044        return 0;
1045    }
1046    assert(dl->dictSize > 0);
1047    assert(cctx->cdict == NULL);
1048    assert(cctx->prefixDict.dict == NULL);
1049
1050    dl->cdict = ZSTD_createCDict_advanced2(
1051            dl->dict,
1052            dl->dictSize,
1053            ZSTD_dlm_byRef,
1054            dl->dictContentType,
1055            &cctx->requestedParams,
1056            cctx->customMem);
1057    RETURN_ERROR_IF(!dl->cdict, memory_allocation, "ZSTD_createCDict_advanced failed");
1058    cctx->cdict = dl->cdict;
1059    return 0;
1060}
1061
1062size_t ZSTD_CCtx_loadDictionary_advanced(
1063        ZSTD_CCtx* cctx, const void* dict, size_t dictSize,
1064        ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType)
1065{
1066    RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong,
1067                    "Can't load a dictionary when ctx is not in init stage.");
1068    DEBUGLOG(4, "ZSTD_CCtx_loadDictionary_advanced (size: %u)", (U32)dictSize);
1069    ZSTD_clearAllDicts(cctx);  /* in case one already exists */
1070    if (dict == NULL || dictSize == 0)  /* no dictionary mode */
1071        return 0;
1072    if (dictLoadMethod == ZSTD_dlm_byRef) {
1073        cctx->localDict.dict = dict;
1074    } else {
1075        void* dictBuffer;
1076        RETURN_ERROR_IF(cctx->staticSize, memory_allocation,
1077                        "no malloc for static CCtx");
1078        dictBuffer = ZSTD_customMalloc(dictSize, cctx->customMem);
1079        RETURN_ERROR_IF(!dictBuffer, memory_allocation, "NULL pointer!");
1080        ZSTD_memcpy(dictBuffer, dict, dictSize);
1081        cctx->localDict.dictBuffer = dictBuffer;
1082        cctx->localDict.dict = dictBuffer;
1083    }
1084    cctx->localDict.dictSize = dictSize;
1085    cctx->localDict.dictContentType = dictContentType;
1086    return 0;
1087}
1088
1089size_t ZSTD_CCtx_loadDictionary_byReference(
1090      ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
1091{
1092    return ZSTD_CCtx_loadDictionary_advanced(
1093            cctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
1094}
1095
1096size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize)
1097{
1098    return ZSTD_CCtx_loadDictionary_advanced(
1099            cctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
1100}
1101
1102
1103size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
1104{
1105    RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong,
1106                    "Can't ref a dict when ctx not in init stage.");
1107    /* Free the existing local cdict (if any) to save memory. */
1108    ZSTD_clearAllDicts(cctx);
1109    cctx->cdict = cdict;
1110    return 0;
1111}
1112
1113size_t ZSTD_CCtx_refThreadPool(ZSTD_CCtx* cctx, ZSTD_threadPool* pool)
1114{
1115    RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong,
1116                    "Can't ref a pool when ctx not in init stage.");
1117    cctx->pool = pool;
1118    return 0;
1119}
1120
1121size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize)
1122{
1123    return ZSTD_CCtx_refPrefix_advanced(cctx, prefix, prefixSize, ZSTD_dct_rawContent);
1124}
1125
1126size_t ZSTD_CCtx_refPrefix_advanced(
1127        ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
1128{
1129    RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong,
1130                    "Can't ref a prefix when ctx not in init stage.");
1131    ZSTD_clearAllDicts(cctx);
1132    if (prefix != NULL && prefixSize > 0) {
1133        cctx->prefixDict.dict = prefix;
1134        cctx->prefixDict.dictSize = prefixSize;
1135        cctx->prefixDict.dictContentType = dictContentType;
1136    }
1137    return 0;
1138}
1139
1140/*! ZSTD_CCtx_reset() :
1141 *  Also dumps dictionary */
1142size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx, ZSTD_ResetDirective reset)
1143{
1144    if ( (reset == ZSTD_reset_session_only)
1145      || (reset == ZSTD_reset_session_and_parameters) ) {
1146        cctx->streamStage = zcss_init;
1147        cctx->pledgedSrcSizePlusOne = 0;
1148    }
1149    if ( (reset == ZSTD_reset_parameters)
1150      || (reset == ZSTD_reset_session_and_parameters) ) {
1151        RETURN_ERROR_IF(cctx->streamStage != zcss_init, stage_wrong,
1152                        "Can't reset parameters only when not in init stage.");
1153        ZSTD_clearAllDicts(cctx);
1154        return ZSTD_CCtxParams_reset(&cctx->requestedParams);
1155    }
1156    return 0;
1157}
1158
1159
1160/* ZSTD_checkCParams() :
1161    control CParam values remain within authorized range.
1162    @return : 0, or an error code if one value is beyond authorized range */
1163size_t ZSTD_checkCParams(ZSTD_compressionParameters cParams)
1164{
1165    BOUNDCHECK(ZSTD_c_windowLog, (int)cParams.windowLog);
1166    BOUNDCHECK(ZSTD_c_chainLog,  (int)cParams.chainLog);
1167    BOUNDCHECK(ZSTD_c_hashLog,   (int)cParams.hashLog);
1168    BOUNDCHECK(ZSTD_c_searchLog, (int)cParams.searchLog);
1169    BOUNDCHECK(ZSTD_c_minMatch,  (int)cParams.minMatch);
1170    BOUNDCHECK(ZSTD_c_targetLength,(int)cParams.targetLength);
1171    BOUNDCHECK(ZSTD_c_strategy,  cParams.strategy);
1172    return 0;
1173}
1174
1175/* ZSTD_clampCParams() :
1176 *  make CParam values within valid range.
1177 *  @return : valid CParams */
1178static ZSTD_compressionParameters
1179ZSTD_clampCParams(ZSTD_compressionParameters cParams)
1180{
1181#   define CLAMP_TYPE(cParam, val, type) {                                \
1182        ZSTD_bounds const bounds = ZSTD_cParam_getBounds(cParam);         \
1183        if ((int)val<bounds.lowerBound) val=(type)bounds.lowerBound;      \
1184        else if ((int)val>bounds.upperBound) val=(type)bounds.upperBound; \
1185    }
1186#   define CLAMP(cParam, val) CLAMP_TYPE(cParam, val, unsigned)
1187    CLAMP(ZSTD_c_windowLog, cParams.windowLog);
1188    CLAMP(ZSTD_c_chainLog,  cParams.chainLog);
1189    CLAMP(ZSTD_c_hashLog,   cParams.hashLog);
1190    CLAMP(ZSTD_c_searchLog, cParams.searchLog);
1191    CLAMP(ZSTD_c_minMatch,  cParams.minMatch);
1192    CLAMP(ZSTD_c_targetLength,cParams.targetLength);
1193    CLAMP_TYPE(ZSTD_c_strategy,cParams.strategy, ZSTD_strategy);
1194    return cParams;
1195}
1196
1197/* ZSTD_cycleLog() :
1198 *  condition for correct operation : hashLog > 1 */
1199U32 ZSTD_cycleLog(U32 hashLog, ZSTD_strategy strat)
1200{
1201    U32 const btScale = ((U32)strat >= (U32)ZSTD_btlazy2);
1202    return hashLog - btScale;
1203}
1204
1205/* ZSTD_dictAndWindowLog() :
1206 * Returns an adjusted window log that is large enough to fit the source and the dictionary.
1207 * The zstd format says that the entire dictionary is valid if one byte of the dictionary
1208 * is within the window. So the hashLog and chainLog should be large enough to reference both
1209 * the dictionary and the window. So we must use this adjusted dictAndWindowLog when downsizing
1210 * the hashLog and windowLog.
1211 * NOTE: srcSize must not be ZSTD_CONTENTSIZE_UNKNOWN.
1212 */
1213static U32 ZSTD_dictAndWindowLog(U32 windowLog, U64 srcSize, U64 dictSize)
1214{
1215    const U64 maxWindowSize = 1ULL << ZSTD_WINDOWLOG_MAX;
1216    /* No dictionary ==> No change */
1217    if (dictSize == 0) {
1218        return windowLog;
1219    }
1220    assert(windowLog <= ZSTD_WINDOWLOG_MAX);
1221    assert(srcSize != ZSTD_CONTENTSIZE_UNKNOWN); /* Handled in ZSTD_adjustCParams_internal() */
1222    {
1223        U64 const windowSize = 1ULL << windowLog;
1224        U64 const dictAndWindowSize = dictSize + windowSize;
1225        /* If the window size is already large enough to fit both the source and the dictionary
1226         * then just use the window size. Otherwise adjust so that it fits the dictionary and
1227         * the window.
1228         */
1229        if (windowSize >= dictSize + srcSize) {
1230            return windowLog; /* Window size large enough already */
1231        } else if (dictAndWindowSize >= maxWindowSize) {
1232            return ZSTD_WINDOWLOG_MAX; /* Larger than max window log */
1233        } else  {
1234            return ZSTD_highbit32((U32)dictAndWindowSize - 1) + 1;
1235        }
1236    }
1237}
1238
1239/* ZSTD_adjustCParams_internal() :
1240 *  optimize `cPar` for a specified input (`srcSize` and `dictSize`).
1241 *  mostly downsize to reduce memory consumption and initialization latency.
1242 * `srcSize` can be ZSTD_CONTENTSIZE_UNKNOWN when not known.
1243 * `mode` is the mode for parameter adjustment. See docs for `ZSTD_cParamMode_e`.
1244 *  note : `srcSize==0` means 0!
1245 *  condition : cPar is presumed validated (can be checked using ZSTD_checkCParams()). */
1246static ZSTD_compressionParameters
1247ZSTD_adjustCParams_internal(ZSTD_compressionParameters cPar,
1248                            unsigned long long srcSize,
1249                            size_t dictSize,
1250                            ZSTD_cParamMode_e mode)
1251{
1252    const U64 minSrcSize = 513; /* (1<<9) + 1 */
1253    const U64 maxWindowResize = 1ULL << (ZSTD_WINDOWLOG_MAX-1);
1254    assert(ZSTD_checkCParams(cPar)==0);
1255
1256    switch (mode) {
1257    case ZSTD_cpm_unknown:
1258    case ZSTD_cpm_noAttachDict:
1259        /* If we don't know the source size, don't make any
1260         * assumptions about it. We will already have selected
1261         * smaller parameters if a dictionary is in use.
1262         */
1263        break;
1264    case ZSTD_cpm_createCDict:
1265        /* Assume a small source size when creating a dictionary
1266         * with an unknown source size.
1267         */
1268        if (dictSize && srcSize == ZSTD_CONTENTSIZE_UNKNOWN)
1269            srcSize = minSrcSize;
1270        break;
1271    case ZSTD_cpm_attachDict:
1272        /* Dictionary has its own dedicated parameters which have
1273         * already been selected. We are selecting parameters
1274         * for only the source.
1275         */
1276        dictSize = 0;
1277        break;
1278    default:
1279        assert(0);
1280        break;
1281    }
1282
1283    /* resize windowLog if input is small enough, to use less memory */
1284    if ( (srcSize < maxWindowResize)
1285      && (dictSize < maxWindowResize) )  {
1286        U32 const tSize = (U32)(srcSize + dictSize);
1287        static U32 const hashSizeMin = 1 << ZSTD_HASHLOG_MIN;
1288        U32 const srcLog = (tSize < hashSizeMin) ? ZSTD_HASHLOG_MIN :
1289                            ZSTD_highbit32(tSize-1) + 1;
1290        if (cPar.windowLog > srcLog) cPar.windowLog = srcLog;
1291    }
1292    if (srcSize != ZSTD_CONTENTSIZE_UNKNOWN) {
1293        U32 const dictAndWindowLog = ZSTD_dictAndWindowLog(cPar.windowLog, (U64)srcSize, (U64)dictSize);
1294        U32 const cycleLog = ZSTD_cycleLog(cPar.chainLog, cPar.strategy);
1295        if (cPar.hashLog > dictAndWindowLog+1) cPar.hashLog = dictAndWindowLog+1;
1296        if (cycleLog > dictAndWindowLog)
1297            cPar.chainLog -= (cycleLog - dictAndWindowLog);
1298    }
1299
1300    if (cPar.windowLog < ZSTD_WINDOWLOG_ABSOLUTEMIN)
1301        cPar.windowLog = ZSTD_WINDOWLOG_ABSOLUTEMIN;  /* minimum wlog required for valid frame header */
1302
1303    return cPar;
1304}
1305
1306ZSTD_compressionParameters
1307ZSTD_adjustCParams(ZSTD_compressionParameters cPar,
1308                   unsigned long long srcSize,
1309                   size_t dictSize)
1310{
1311    cPar = ZSTD_clampCParams(cPar);   /* resulting cPar is necessarily valid (all parameters within range) */
1312    if (srcSize == 0) srcSize = ZSTD_CONTENTSIZE_UNKNOWN;
1313    return ZSTD_adjustCParams_internal(cPar, srcSize, dictSize, ZSTD_cpm_unknown);
1314}
1315
1316static ZSTD_compressionParameters ZSTD_getCParams_internal(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize, ZSTD_cParamMode_e mode);
1317static ZSTD_parameters ZSTD_getParams_internal(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize, ZSTD_cParamMode_e mode);
1318
1319static void ZSTD_overrideCParams(
1320              ZSTD_compressionParameters* cParams,
1321        const ZSTD_compressionParameters* overrides)
1322{
1323    if (overrides->windowLog)    cParams->windowLog    = overrides->windowLog;
1324    if (overrides->hashLog)      cParams->hashLog      = overrides->hashLog;
1325    if (overrides->chainLog)     cParams->chainLog     = overrides->chainLog;
1326    if (overrides->searchLog)    cParams->searchLog    = overrides->searchLog;
1327    if (overrides->minMatch)     cParams->minMatch     = overrides->minMatch;
1328    if (overrides->targetLength) cParams->targetLength = overrides->targetLength;
1329    if (overrides->strategy)     cParams->strategy     = overrides->strategy;
1330}
1331
1332ZSTD_compressionParameters ZSTD_getCParamsFromCCtxParams(
1333        const ZSTD_CCtx_params* CCtxParams, U64 srcSizeHint, size_t dictSize, ZSTD_cParamMode_e mode)
1334{
1335    ZSTD_compressionParameters cParams;
1336    if (srcSizeHint == ZSTD_CONTENTSIZE_UNKNOWN && CCtxParams->srcSizeHint > 0) {
1337      srcSizeHint = CCtxParams->srcSizeHint;
1338    }
1339    cParams = ZSTD_getCParams_internal(CCtxParams->compressionLevel, srcSizeHint, dictSize, mode);
1340    if (CCtxParams->ldmParams.enableLdm == ZSTD_ps_enable) cParams.windowLog = ZSTD_LDM_DEFAULT_WINDOW_LOG;
1341    ZSTD_overrideCParams(&cParams, &CCtxParams->cParams);
1342    assert(!ZSTD_checkCParams(cParams));
1343    /* srcSizeHint == 0 means 0 */
1344    return ZSTD_adjustCParams_internal(cParams, srcSizeHint, dictSize, mode);
1345}
1346
1347static size_t
1348ZSTD_sizeof_matchState(const ZSTD_compressionParameters* const cParams,
1349                       const ZSTD_paramSwitch_e useRowMatchFinder,
1350                       const U32 enableDedicatedDictSearch,
1351                       const U32 forCCtx)
1352{
1353    /* chain table size should be 0 for fast or row-hash strategies */
1354    size_t const chainSize = ZSTD_allocateChainTable(cParams->strategy, useRowMatchFinder, enableDedicatedDictSearch && !forCCtx)
1355                                ? ((size_t)1 << cParams->chainLog)
1356                                : 0;
1357    size_t const hSize = ((size_t)1) << cParams->hashLog;
1358    U32    const hashLog3 = (forCCtx && cParams->minMatch==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
1359    size_t const h3Size = hashLog3 ? ((size_t)1) << hashLog3 : 0;
1360    /* We don't use ZSTD_cwksp_alloc_size() here because the tables aren't
1361     * surrounded by redzones in ASAN. */
1362    size_t const tableSpace = chainSize * sizeof(U32)
1363                            + hSize * sizeof(U32)
1364                            + h3Size * sizeof(U32);
1365    size_t const optPotentialSpace =
1366        ZSTD_cwksp_aligned_alloc_size((MaxML+1) * sizeof(U32))
1367      + ZSTD_cwksp_aligned_alloc_size((MaxLL+1) * sizeof(U32))
1368      + ZSTD_cwksp_aligned_alloc_size((MaxOff+1) * sizeof(U32))
1369      + ZSTD_cwksp_aligned_alloc_size((1<<Litbits) * sizeof(U32))
1370      + ZSTD_cwksp_aligned_alloc_size((ZSTD_OPT_NUM+1) * sizeof(ZSTD_match_t))
1371      + ZSTD_cwksp_aligned_alloc_size((ZSTD_OPT_NUM+1) * sizeof(ZSTD_optimal_t));
1372    size_t const lazyAdditionalSpace = ZSTD_rowMatchFinderUsed(cParams->strategy, useRowMatchFinder)
1373                                            ? ZSTD_cwksp_aligned_alloc_size(hSize*sizeof(U16))
1374                                            : 0;
1375    size_t const optSpace = (forCCtx && (cParams->strategy >= ZSTD_btopt))
1376                                ? optPotentialSpace
1377                                : 0;
1378    size_t const slackSpace = ZSTD_cwksp_slack_space_required();
1379
1380    /* tables are guaranteed to be sized in multiples of 64 bytes (or 16 uint32_t) */
1381    ZSTD_STATIC_ASSERT(ZSTD_HASHLOG_MIN >= 4 && ZSTD_WINDOWLOG_MIN >= 4 && ZSTD_CHAINLOG_MIN >= 4);
1382    assert(useRowMatchFinder != ZSTD_ps_auto);
1383
1384    DEBUGLOG(4, "chainSize: %u - hSize: %u - h3Size: %u",
1385                (U32)chainSize, (U32)hSize, (U32)h3Size);
1386    return tableSpace + optSpace + slackSpace + lazyAdditionalSpace;
1387}
1388
1389static size_t ZSTD_estimateCCtxSize_usingCCtxParams_internal(
1390        const ZSTD_compressionParameters* cParams,
1391        const ldmParams_t* ldmParams,
1392        const int isStatic,
1393        const ZSTD_paramSwitch_e useRowMatchFinder,
1394        const size_t buffInSize,
1395        const size_t buffOutSize,
1396        const U64 pledgedSrcSize)
1397{
1398    size_t const windowSize = (size_t) BOUNDED(1ULL, 1ULL << cParams->windowLog, pledgedSrcSize);
1399    size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
1400    U32    const divider = (cParams->minMatch==3) ? 3 : 4;
1401    size_t const maxNbSeq = blockSize / divider;
1402    size_t const tokenSpace = ZSTD_cwksp_alloc_size(WILDCOPY_OVERLENGTH + blockSize)
1403                            + ZSTD_cwksp_aligned_alloc_size(maxNbSeq * sizeof(seqDef))
1404                            + 3 * ZSTD_cwksp_alloc_size(maxNbSeq * sizeof(BYTE));
1405    size_t const entropySpace = ZSTD_cwksp_alloc_size(ENTROPY_WORKSPACE_SIZE);
1406    size_t const blockStateSpace = 2 * ZSTD_cwksp_alloc_size(sizeof(ZSTD_compressedBlockState_t));
1407    size_t const matchStateSize = ZSTD_sizeof_matchState(cParams, useRowMatchFinder, /* enableDedicatedDictSearch */ 0, /* forCCtx */ 1);
1408
1409    size_t const ldmSpace = ZSTD_ldm_getTableSize(*ldmParams);
1410    size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(*ldmParams, blockSize);
1411    size_t const ldmSeqSpace = ldmParams->enableLdm == ZSTD_ps_enable ?
1412        ZSTD_cwksp_aligned_alloc_size(maxNbLdmSeq * sizeof(rawSeq)) : 0;
1413
1414
1415    size_t const bufferSpace = ZSTD_cwksp_alloc_size(buffInSize)
1416                             + ZSTD_cwksp_alloc_size(buffOutSize);
1417
1418    size_t const cctxSpace = isStatic ? ZSTD_cwksp_alloc_size(sizeof(ZSTD_CCtx)) : 0;
1419
1420    size_t const neededSpace =
1421        cctxSpace +
1422        entropySpace +
1423        blockStateSpace +
1424        ldmSpace +
1425        ldmSeqSpace +
1426        matchStateSize +
1427        tokenSpace +
1428        bufferSpace;
1429
1430    DEBUGLOG(5, "estimate workspace : %u", (U32)neededSpace);
1431    return neededSpace;
1432}
1433
1434size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params)
1435{
1436    ZSTD_compressionParameters const cParams =
1437                ZSTD_getCParamsFromCCtxParams(params, ZSTD_CONTENTSIZE_UNKNOWN, 0, ZSTD_cpm_noAttachDict);
1438    ZSTD_paramSwitch_e const useRowMatchFinder = ZSTD_resolveRowMatchFinderMode(params->useRowMatchFinder,
1439                                                                               &cParams);
1440
1441    RETURN_ERROR_IF(params->nbWorkers > 0, GENERIC, "Estimate CCtx size is supported for single-threaded compression only.");
1442    /* estimateCCtxSize is for one-shot compression. So no buffers should
1443     * be needed. However, we still allocate two 0-sized buffers, which can
1444     * take space under ASAN. */
1445    return ZSTD_estimateCCtxSize_usingCCtxParams_internal(
1446        &cParams, &params->ldmParams, 1, useRowMatchFinder, 0, 0, ZSTD_CONTENTSIZE_UNKNOWN);
1447}
1448
1449size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams)
1450{
1451    ZSTD_CCtx_params initialParams = ZSTD_makeCCtxParamsFromCParams(cParams);
1452    if (ZSTD_rowMatchFinderSupported(cParams.strategy)) {
1453        /* Pick bigger of not using and using row-based matchfinder for greedy and lazy strategies */
1454        size_t noRowCCtxSize;
1455        size_t rowCCtxSize;
1456        initialParams.useRowMatchFinder = ZSTD_ps_disable;
1457        noRowCCtxSize = ZSTD_estimateCCtxSize_usingCCtxParams(&initialParams);
1458        initialParams.useRowMatchFinder = ZSTD_ps_enable;
1459        rowCCtxSize = ZSTD_estimateCCtxSize_usingCCtxParams(&initialParams);
1460        return MAX(noRowCCtxSize, rowCCtxSize);
1461    } else {
1462        return ZSTD_estimateCCtxSize_usingCCtxParams(&initialParams);
1463    }
1464}
1465
1466static size_t ZSTD_estimateCCtxSize_internal(int compressionLevel)
1467{
1468    int tier = 0;
1469    size_t largestSize = 0;
1470    static const unsigned long long srcSizeTiers[4] = {16 KB, 128 KB, 256 KB, ZSTD_CONTENTSIZE_UNKNOWN};
1471    for (; tier < 4; ++tier) {
1472        /* Choose the set of cParams for a given level across all srcSizes that give the largest cctxSize */
1473        ZSTD_compressionParameters const cParams = ZSTD_getCParams_internal(compressionLevel, srcSizeTiers[tier], 0, ZSTD_cpm_noAttachDict);
1474        largestSize = MAX(ZSTD_estimateCCtxSize_usingCParams(cParams), largestSize);
1475    }
1476    return largestSize;
1477}
1478
1479size_t ZSTD_estimateCCtxSize(int compressionLevel)
1480{
1481    int level;
1482    size_t memBudget = 0;
1483    for (level=MIN(compressionLevel, 1); level<=compressionLevel; level++) {
1484        /* Ensure monotonically increasing memory usage as compression level increases */
1485        size_t const newMB = ZSTD_estimateCCtxSize_internal(level);
1486        if (newMB > memBudget) memBudget = newMB;
1487    }
1488    return memBudget;
1489}
1490
1491size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params)
1492{
1493    RETURN_ERROR_IF(params->nbWorkers > 0, GENERIC, "Estimate CCtx size is supported for single-threaded compression only.");
1494    {   ZSTD_compressionParameters const cParams =
1495                ZSTD_getCParamsFromCCtxParams(params, ZSTD_CONTENTSIZE_UNKNOWN, 0, ZSTD_cpm_noAttachDict);
1496        size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, (size_t)1 << cParams.windowLog);
1497        size_t const inBuffSize = (params->inBufferMode == ZSTD_bm_buffered)
1498                ? ((size_t)1 << cParams.windowLog) + blockSize
1499                : 0;
1500        size_t const outBuffSize = (params->outBufferMode == ZSTD_bm_buffered)
1501                ? ZSTD_compressBound(blockSize) + 1
1502                : 0;
1503        ZSTD_paramSwitch_e const useRowMatchFinder = ZSTD_resolveRowMatchFinderMode(params->useRowMatchFinder, &params->cParams);
1504
1505        return ZSTD_estimateCCtxSize_usingCCtxParams_internal(
1506            &cParams, &params->ldmParams, 1, useRowMatchFinder, inBuffSize, outBuffSize,
1507            ZSTD_CONTENTSIZE_UNKNOWN);
1508    }
1509}
1510
1511size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams)
1512{
1513    ZSTD_CCtx_params initialParams = ZSTD_makeCCtxParamsFromCParams(cParams);
1514    if (ZSTD_rowMatchFinderSupported(cParams.strategy)) {
1515        /* Pick bigger of not using and using row-based matchfinder for greedy and lazy strategies */
1516        size_t noRowCCtxSize;
1517        size_t rowCCtxSize;
1518        initialParams.useRowMatchFinder = ZSTD_ps_disable;
1519        noRowCCtxSize = ZSTD_estimateCStreamSize_usingCCtxParams(&initialParams);
1520        initialParams.useRowMatchFinder = ZSTD_ps_enable;
1521        rowCCtxSize = ZSTD_estimateCStreamSize_usingCCtxParams(&initialParams);
1522        return MAX(noRowCCtxSize, rowCCtxSize);
1523    } else {
1524        return ZSTD_estimateCStreamSize_usingCCtxParams(&initialParams);
1525    }
1526}
1527
1528static size_t ZSTD_estimateCStreamSize_internal(int compressionLevel)
1529{
1530    ZSTD_compressionParameters const cParams = ZSTD_getCParams_internal(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, 0, ZSTD_cpm_noAttachDict);
1531    return ZSTD_estimateCStreamSize_usingCParams(cParams);
1532}
1533
1534size_t ZSTD_estimateCStreamSize(int compressionLevel)
1535{
1536    int level;
1537    size_t memBudget = 0;
1538    for (level=MIN(compressionLevel, 1); level<=compressionLevel; level++) {
1539        size_t const newMB = ZSTD_estimateCStreamSize_internal(level);
1540        if (newMB > memBudget) memBudget = newMB;
1541    }
1542    return memBudget;
1543}
1544
1545/* ZSTD_getFrameProgression():
1546 * tells how much data has been consumed (input) and produced (output) for current frame.
1547 * able to count progression inside worker threads (non-blocking mode).
1548 */
1549ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx* cctx)
1550{
1551    {   ZSTD_frameProgression fp;
1552        size_t const buffered = (cctx->inBuff == NULL) ? 0 :
1553                                cctx->inBuffPos - cctx->inToCompress;
1554        if (buffered) assert(cctx->inBuffPos >= cctx->inToCompress);
1555        assert(buffered <= ZSTD_BLOCKSIZE_MAX);
1556        fp.ingested = cctx->consumedSrcSize + buffered;
1557        fp.consumed = cctx->consumedSrcSize;
1558        fp.produced = cctx->producedCSize;
1559        fp.flushed  = cctx->producedCSize;   /* simplified; some data might still be left within streaming output buffer */
1560        fp.currentJobID = 0;
1561        fp.nbActiveWorkers = 0;
1562        return fp;
1563}   }
1564
1565/*! ZSTD_toFlushNow()
1566 *  Only useful for multithreading scenarios currently (nbWorkers >= 1).
1567 */
1568size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx)
1569{
1570    (void)cctx;
1571    return 0;   /* over-simplification; could also check if context is currently running in streaming mode, and in which case, report how many bytes are left to be flushed within output buffer */
1572}
1573
1574static void ZSTD_assertEqualCParams(ZSTD_compressionParameters cParams1,
1575                                    ZSTD_compressionParameters cParams2)
1576{
1577    (void)cParams1;
1578    (void)cParams2;
1579    assert(cParams1.windowLog    == cParams2.windowLog);
1580    assert(cParams1.chainLog     == cParams2.chainLog);
1581    assert(cParams1.hashLog      == cParams2.hashLog);
1582    assert(cParams1.searchLog    == cParams2.searchLog);
1583    assert(cParams1.minMatch     == cParams2.minMatch);
1584    assert(cParams1.targetLength == cParams2.targetLength);
1585    assert(cParams1.strategy     == cParams2.strategy);
1586}
1587
1588void ZSTD_reset_compressedBlockState(ZSTD_compressedBlockState_t* bs)
1589{
1590    int i;
1591    for (i = 0; i < ZSTD_REP_NUM; ++i)
1592        bs->rep[i] = repStartValue[i];
1593    bs->entropy.huf.repeatMode = HUF_repeat_none;
1594    bs->entropy.fse.offcode_repeatMode = FSE_repeat_none;
1595    bs->entropy.fse.matchlength_repeatMode = FSE_repeat_none;
1596    bs->entropy.fse.litlength_repeatMode = FSE_repeat_none;
1597}
1598
1599/*! ZSTD_invalidateMatchState()
1600 *  Invalidate all the matches in the match finder tables.
1601 *  Requires nextSrc and base to be set (can be NULL).
1602 */
1603static void ZSTD_invalidateMatchState(ZSTD_matchState_t* ms)
1604{
1605    ZSTD_window_clear(&ms->window);
1606
1607    ms->nextToUpdate = ms->window.dictLimit;
1608    ms->loadedDictEnd = 0;
1609    ms->opt.litLengthSum = 0;  /* force reset of btopt stats */
1610    ms->dictMatchState = NULL;
1611}
1612
1613/*
1614 * Controls, for this matchState reset, whether the tables need to be cleared /
1615 * prepared for the coming compression (ZSTDcrp_makeClean), or whether the
1616 * tables can be left unclean (ZSTDcrp_leaveDirty), because we know that a
1617 * subsequent operation will overwrite the table space anyways (e.g., copying
1618 * the matchState contents in from a CDict).
1619 */
1620typedef enum {
1621    ZSTDcrp_makeClean,
1622    ZSTDcrp_leaveDirty
1623} ZSTD_compResetPolicy_e;
1624
1625/*
1626 * Controls, for this matchState reset, whether indexing can continue where it
1627 * left off (ZSTDirp_continue), or whether it needs to be restarted from zero
1628 * (ZSTDirp_reset).
1629 */
1630typedef enum {
1631    ZSTDirp_continue,
1632    ZSTDirp_reset
1633} ZSTD_indexResetPolicy_e;
1634
1635typedef enum {
1636    ZSTD_resetTarget_CDict,
1637    ZSTD_resetTarget_CCtx
1638} ZSTD_resetTarget_e;
1639
1640
1641static size_t
1642ZSTD_reset_matchState(ZSTD_matchState_t* ms,
1643                      ZSTD_cwksp* ws,
1644                const ZSTD_compressionParameters* cParams,
1645                const ZSTD_paramSwitch_e useRowMatchFinder,
1646                const ZSTD_compResetPolicy_e crp,
1647                const ZSTD_indexResetPolicy_e forceResetIndex,
1648                const ZSTD_resetTarget_e forWho)
1649{
1650    /* disable chain table allocation for fast or row-based strategies */
1651    size_t const chainSize = ZSTD_allocateChainTable(cParams->strategy, useRowMatchFinder,
1652                                                     ms->dedicatedDictSearch && (forWho == ZSTD_resetTarget_CDict))
1653                                ? ((size_t)1 << cParams->chainLog)
1654                                : 0;
1655    size_t const hSize = ((size_t)1) << cParams->hashLog;
1656    U32    const hashLog3 = ((forWho == ZSTD_resetTarget_CCtx) && cParams->minMatch==3) ? MIN(ZSTD_HASHLOG3_MAX, cParams->windowLog) : 0;
1657    size_t const h3Size = hashLog3 ? ((size_t)1) << hashLog3 : 0;
1658
1659    DEBUGLOG(4, "reset indices : %u", forceResetIndex == ZSTDirp_reset);
1660    assert(useRowMatchFinder != ZSTD_ps_auto);
1661    if (forceResetIndex == ZSTDirp_reset) {
1662        ZSTD_window_init(&ms->window);
1663        ZSTD_cwksp_mark_tables_dirty(ws);
1664    }
1665
1666    ms->hashLog3 = hashLog3;
1667
1668    ZSTD_invalidateMatchState(ms);
1669
1670    assert(!ZSTD_cwksp_reserve_failed(ws)); /* check that allocation hasn't already failed */
1671
1672    ZSTD_cwksp_clear_tables(ws);
1673
1674    DEBUGLOG(5, "reserving table space");
1675    /* table Space */
1676    ms->hashTable = (U32*)ZSTD_cwksp_reserve_table(ws, hSize * sizeof(U32));
1677    ms->chainTable = (U32*)ZSTD_cwksp_reserve_table(ws, chainSize * sizeof(U32));
1678    ms->hashTable3 = (U32*)ZSTD_cwksp_reserve_table(ws, h3Size * sizeof(U32));
1679    RETURN_ERROR_IF(ZSTD_cwksp_reserve_failed(ws), memory_allocation,
1680                    "failed a workspace allocation in ZSTD_reset_matchState");
1681
1682    DEBUGLOG(4, "reset table : %u", crp!=ZSTDcrp_leaveDirty);
1683    if (crp!=ZSTDcrp_leaveDirty) {
1684        /* reset tables only */
1685        ZSTD_cwksp_clean_tables(ws);
1686    }
1687
1688    /* opt parser space */
1689    if ((forWho == ZSTD_resetTarget_CCtx) && (cParams->strategy >= ZSTD_btopt)) {
1690        DEBUGLOG(4, "reserving optimal parser space");
1691        ms->opt.litFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (1<<Litbits) * sizeof(unsigned));
1692        ms->opt.litLengthFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxLL+1) * sizeof(unsigned));
1693        ms->opt.matchLengthFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxML+1) * sizeof(unsigned));
1694        ms->opt.offCodeFreq = (unsigned*)ZSTD_cwksp_reserve_aligned(ws, (MaxOff+1) * sizeof(unsigned));
1695        ms->opt.matchTable = (ZSTD_match_t*)ZSTD_cwksp_reserve_aligned(ws, (ZSTD_OPT_NUM+1) * sizeof(ZSTD_match_t));
1696        ms->opt.priceTable = (ZSTD_optimal_t*)ZSTD_cwksp_reserve_aligned(ws, (ZSTD_OPT_NUM+1) * sizeof(ZSTD_optimal_t));
1697    }
1698
1699    if (ZSTD_rowMatchFinderUsed(cParams->strategy, useRowMatchFinder)) {
1700        {   /* Row match finder needs an additional table of hashes ("tags") */
1701            size_t const tagTableSize = hSize*sizeof(U16);
1702            ms->tagTable = (U16*)ZSTD_cwksp_reserve_aligned(ws, tagTableSize);
1703            if (ms->tagTable) ZSTD_memset(ms->tagTable, 0, tagTableSize);
1704        }
1705        {   /* Switch to 32-entry rows if searchLog is 5 (or more) */
1706            U32 const rowLog = BOUNDED(4, cParams->searchLog, 6);
1707            assert(cParams->hashLog >= rowLog);
1708            ms->rowHashLog = cParams->hashLog - rowLog;
1709        }
1710    }
1711
1712    ms->cParams = *cParams;
1713
1714    RETURN_ERROR_IF(ZSTD_cwksp_reserve_failed(ws), memory_allocation,
1715                    "failed a workspace allocation in ZSTD_reset_matchState");
1716    return 0;
1717}
1718
1719/* ZSTD_indexTooCloseToMax() :
1720 * minor optimization : prefer memset() rather than reduceIndex()
1721 * which is measurably slow in some circumstances (reported for Visual Studio).
1722 * Works when re-using a context for a lot of smallish inputs :
1723 * if all inputs are smaller than ZSTD_INDEXOVERFLOW_MARGIN,
1724 * memset() will be triggered before reduceIndex().
1725 */
1726#define ZSTD_INDEXOVERFLOW_MARGIN (16 MB)
1727static int ZSTD_indexTooCloseToMax(ZSTD_window_t w)
1728{
1729    return (size_t)(w.nextSrc - w.base) > (ZSTD_CURRENT_MAX - ZSTD_INDEXOVERFLOW_MARGIN);
1730}
1731
1732/* ZSTD_dictTooBig():
1733 * When dictionaries are larger than ZSTD_CHUNKSIZE_MAX they can't be loaded in
1734 * one go generically. So we ensure that in that case we reset the tables to zero,
1735 * so that we can load as much of the dictionary as possible.
1736 */
1737static int ZSTD_dictTooBig(size_t const loadedDictSize)
1738{
1739    return loadedDictSize > ZSTD_CHUNKSIZE_MAX;
1740}
1741
1742/*! ZSTD_resetCCtx_internal() :
1743 * @param loadedDictSize The size of the dictionary to be loaded
1744 * into the context, if any. If no dictionary is used, or the
1745 * dictionary is being attached / copied, then pass 0.
1746 * note : `params` are assumed fully validated at this stage.
1747 */
1748static size_t ZSTD_resetCCtx_internal(ZSTD_CCtx* zc,
1749                                      ZSTD_CCtx_params const* params,
1750                                      U64 const pledgedSrcSize,
1751                                      size_t const loadedDictSize,
1752                                      ZSTD_compResetPolicy_e const crp,
1753                                      ZSTD_buffered_policy_e const zbuff)
1754{
1755    ZSTD_cwksp* const ws = &zc->workspace;
1756    DEBUGLOG(4, "ZSTD_resetCCtx_internal: pledgedSrcSize=%u, wlog=%u, useRowMatchFinder=%d useBlockSplitter=%d",
1757                (U32)pledgedSrcSize, params->cParams.windowLog, (int)params->useRowMatchFinder, (int)params->useBlockSplitter);
1758    assert(!ZSTD_isError(ZSTD_checkCParams(params->cParams)));
1759
1760    zc->isFirstBlock = 1;
1761
1762    /* Set applied params early so we can modify them for LDM,
1763     * and point params at the applied params.
1764     */
1765    zc->appliedParams = *params;
1766    params = &zc->appliedParams;
1767
1768    assert(params->useRowMatchFinder != ZSTD_ps_auto);
1769    assert(params->useBlockSplitter != ZSTD_ps_auto);
1770    assert(params->ldmParams.enableLdm != ZSTD_ps_auto);
1771    if (params->ldmParams.enableLdm == ZSTD_ps_enable) {
1772        /* Adjust long distance matching parameters */
1773        ZSTD_ldm_adjustParameters(&zc->appliedParams.ldmParams, &params->cParams);
1774        assert(params->ldmParams.hashLog >= params->ldmParams.bucketSizeLog);
1775        assert(params->ldmParams.hashRateLog < 32);
1776    }
1777
1778    {   size_t const windowSize = MAX(1, (size_t)MIN(((U64)1 << params->cParams.windowLog), pledgedSrcSize));
1779        size_t const blockSize = MIN(ZSTD_BLOCKSIZE_MAX, windowSize);
1780        U32    const divider = (params->cParams.minMatch==3) ? 3 : 4;
1781        size_t const maxNbSeq = blockSize / divider;
1782        size_t const buffOutSize = (zbuff == ZSTDb_buffered && params->outBufferMode == ZSTD_bm_buffered)
1783                ? ZSTD_compressBound(blockSize) + 1
1784                : 0;
1785        size_t const buffInSize = (zbuff == ZSTDb_buffered && params->inBufferMode == ZSTD_bm_buffered)
1786                ? windowSize + blockSize
1787                : 0;
1788        size_t const maxNbLdmSeq = ZSTD_ldm_getMaxNbSeq(params->ldmParams, blockSize);
1789
1790        int const indexTooClose = ZSTD_indexTooCloseToMax(zc->blockState.matchState.window);
1791        int const dictTooBig = ZSTD_dictTooBig(loadedDictSize);
1792        ZSTD_indexResetPolicy_e needsIndexReset =
1793            (indexTooClose || dictTooBig || !zc->initialized) ? ZSTDirp_reset : ZSTDirp_continue;
1794
1795        size_t const neededSpace =
1796            ZSTD_estimateCCtxSize_usingCCtxParams_internal(
1797                &params->cParams, &params->ldmParams, zc->staticSize != 0, params->useRowMatchFinder,
1798                buffInSize, buffOutSize, pledgedSrcSize);
1799        int resizeWorkspace;
1800
1801        FORWARD_IF_ERROR(neededSpace, "cctx size estimate failed!");
1802
1803        if (!zc->staticSize) ZSTD_cwksp_bump_oversized_duration(ws, 0);
1804
1805        {   /* Check if workspace is large enough, alloc a new one if needed */
1806            int const workspaceTooSmall = ZSTD_cwksp_sizeof(ws) < neededSpace;
1807            int const workspaceWasteful = ZSTD_cwksp_check_wasteful(ws, neededSpace);
1808            resizeWorkspace = workspaceTooSmall || workspaceWasteful;
1809            DEBUGLOG(4, "Need %zu B workspace", neededSpace);
1810            DEBUGLOG(4, "windowSize: %zu - blockSize: %zu", windowSize, blockSize);
1811
1812            if (resizeWorkspace) {
1813                DEBUGLOG(4, "Resize workspaceSize from %zuKB to %zuKB",
1814                            ZSTD_cwksp_sizeof(ws) >> 10,
1815                            neededSpace >> 10);
1816
1817                RETURN_ERROR_IF(zc->staticSize, memory_allocation, "static cctx : no resize");
1818
1819                needsIndexReset = ZSTDirp_reset;
1820
1821                ZSTD_cwksp_free(ws, zc->customMem);
1822                FORWARD_IF_ERROR(ZSTD_cwksp_create(ws, neededSpace, zc->customMem), "");
1823
1824                DEBUGLOG(5, "reserving object space");
1825                /* Statically sized space.
1826                 * entropyWorkspace never moves,
1827                 * though prev/next block swap places */
1828                assert(ZSTD_cwksp_check_available(ws, 2 * sizeof(ZSTD_compressedBlockState_t)));
1829                zc->blockState.prevCBlock = (ZSTD_compressedBlockState_t*) ZSTD_cwksp_reserve_object(ws, sizeof(ZSTD_compressedBlockState_t));
1830                RETURN_ERROR_IF(zc->blockState.prevCBlock == NULL, memory_allocation, "couldn't allocate prevCBlock");
1831                zc->blockState.nextCBlock = (ZSTD_compressedBlockState_t*) ZSTD_cwksp_reserve_object(ws, sizeof(ZSTD_compressedBlockState_t));
1832                RETURN_ERROR_IF(zc->blockState.nextCBlock == NULL, memory_allocation, "couldn't allocate nextCBlock");
1833                zc->entropyWorkspace = (U32*) ZSTD_cwksp_reserve_object(ws, ENTROPY_WORKSPACE_SIZE);
1834                RETURN_ERROR_IF(zc->entropyWorkspace == NULL, memory_allocation, "couldn't allocate entropyWorkspace");
1835        }   }
1836
1837        ZSTD_cwksp_clear(ws);
1838
1839        /* init params */
1840        zc->blockState.matchState.cParams = params->cParams;
1841        zc->pledgedSrcSizePlusOne = pledgedSrcSize+1;
1842        zc->consumedSrcSize = 0;
1843        zc->producedCSize = 0;
1844        if (pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN)
1845            zc->appliedParams.fParams.contentSizeFlag = 0;
1846        DEBUGLOG(4, "pledged content size : %u ; flag : %u",
1847            (unsigned)pledgedSrcSize, zc->appliedParams.fParams.contentSizeFlag);
1848        zc->blockSize = blockSize;
1849
1850        xxh64_reset(&zc->xxhState, 0);
1851        zc->stage = ZSTDcs_init;
1852        zc->dictID = 0;
1853        zc->dictContentSize = 0;
1854
1855        ZSTD_reset_compressedBlockState(zc->blockState.prevCBlock);
1856
1857        /* ZSTD_wildcopy() is used to copy into the literals buffer,
1858         * so we have to oversize the buffer by WILDCOPY_OVERLENGTH bytes.
1859         */
1860        zc->seqStore.litStart = ZSTD_cwksp_reserve_buffer(ws, blockSize + WILDCOPY_OVERLENGTH);
1861        zc->seqStore.maxNbLit = blockSize;
1862
1863        /* buffers */
1864        zc->bufferedPolicy = zbuff;
1865        zc->inBuffSize = buffInSize;
1866        zc->inBuff = (char*)ZSTD_cwksp_reserve_buffer(ws, buffInSize);
1867        zc->outBuffSize = buffOutSize;
1868        zc->outBuff = (char*)ZSTD_cwksp_reserve_buffer(ws, buffOutSize);
1869
1870        /* ldm bucketOffsets table */
1871        if (params->ldmParams.enableLdm == ZSTD_ps_enable) {
1872            /* TODO: avoid memset? */
1873            size_t const numBuckets =
1874                  ((size_t)1) << (params->ldmParams.hashLog -
1875                                  params->ldmParams.bucketSizeLog);
1876            zc->ldmState.bucketOffsets = ZSTD_cwksp_reserve_buffer(ws, numBuckets);
1877            ZSTD_memset(zc->ldmState.bucketOffsets, 0, numBuckets);
1878        }
1879
1880        /* sequences storage */
1881        ZSTD_referenceExternalSequences(zc, NULL, 0);
1882        zc->seqStore.maxNbSeq = maxNbSeq;
1883        zc->seqStore.llCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
1884        zc->seqStore.mlCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
1885        zc->seqStore.ofCode = ZSTD_cwksp_reserve_buffer(ws, maxNbSeq * sizeof(BYTE));
1886        zc->seqStore.sequencesStart = (seqDef*)ZSTD_cwksp_reserve_aligned(ws, maxNbSeq * sizeof(seqDef));
1887
1888        FORWARD_IF_ERROR(ZSTD_reset_matchState(
1889            &zc->blockState.matchState,
1890            ws,
1891            &params->cParams,
1892            params->useRowMatchFinder,
1893            crp,
1894            needsIndexReset,
1895            ZSTD_resetTarget_CCtx), "");
1896
1897        /* ldm hash table */
1898        if (params->ldmParams.enableLdm == ZSTD_ps_enable) {
1899            /* TODO: avoid memset? */
1900            size_t const ldmHSize = ((size_t)1) << params->ldmParams.hashLog;
1901            zc->ldmState.hashTable = (ldmEntry_t*)ZSTD_cwksp_reserve_aligned(ws, ldmHSize * sizeof(ldmEntry_t));
1902            ZSTD_memset(zc->ldmState.hashTable, 0, ldmHSize * sizeof(ldmEntry_t));
1903            zc->ldmSequences = (rawSeq*)ZSTD_cwksp_reserve_aligned(ws, maxNbLdmSeq * sizeof(rawSeq));
1904            zc->maxNbLdmSequences = maxNbLdmSeq;
1905
1906            ZSTD_window_init(&zc->ldmState.window);
1907            zc->ldmState.loadedDictEnd = 0;
1908        }
1909
1910        DEBUGLOG(3, "wksp: finished allocating, %zd bytes remain available", ZSTD_cwksp_available_space(ws));
1911        assert(ZSTD_cwksp_estimated_space_within_bounds(ws, neededSpace, resizeWorkspace));
1912
1913        zc->initialized = 1;
1914
1915        return 0;
1916    }
1917}
1918
1919/* ZSTD_invalidateRepCodes() :
1920 * ensures next compression will not use repcodes from previous block.
1921 * Note : only works with regular variant;
1922 *        do not use with extDict variant ! */
1923void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx) {
1924    int i;
1925    for (i=0; i<ZSTD_REP_NUM; i++) cctx->blockState.prevCBlock->rep[i] = 0;
1926    assert(!ZSTD_window_hasExtDict(cctx->blockState.matchState.window));
1927}
1928
1929/* These are the approximate sizes for each strategy past which copying the
1930 * dictionary tables into the working context is faster than using them
1931 * in-place.
1932 */
1933static const size_t attachDictSizeCutoffs[ZSTD_STRATEGY_MAX+1] = {
1934    8 KB,  /* unused */
1935    8 KB,  /* ZSTD_fast */
1936    16 KB, /* ZSTD_dfast */
1937    32 KB, /* ZSTD_greedy */
1938    32 KB, /* ZSTD_lazy */
1939    32 KB, /* ZSTD_lazy2 */
1940    32 KB, /* ZSTD_btlazy2 */
1941    32 KB, /* ZSTD_btopt */
1942    8 KB,  /* ZSTD_btultra */
1943    8 KB   /* ZSTD_btultra2 */
1944};
1945
1946static int ZSTD_shouldAttachDict(const ZSTD_CDict* cdict,
1947                                 const ZSTD_CCtx_params* params,
1948                                 U64 pledgedSrcSize)
1949{
1950    size_t cutoff = attachDictSizeCutoffs[cdict->matchState.cParams.strategy];
1951    int const dedicatedDictSearch = cdict->matchState.dedicatedDictSearch;
1952    return dedicatedDictSearch
1953        || ( ( pledgedSrcSize <= cutoff
1954            || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
1955            || params->attachDictPref == ZSTD_dictForceAttach )
1956          && params->attachDictPref != ZSTD_dictForceCopy
1957          && !params->forceWindow ); /* dictMatchState isn't correctly
1958                                      * handled in _enforceMaxDist */
1959}
1960
1961static size_t
1962ZSTD_resetCCtx_byAttachingCDict(ZSTD_CCtx* cctx,
1963                        const ZSTD_CDict* cdict,
1964                        ZSTD_CCtx_params params,
1965                        U64 pledgedSrcSize,
1966                        ZSTD_buffered_policy_e zbuff)
1967{
1968    DEBUGLOG(4, "ZSTD_resetCCtx_byAttachingCDict() pledgedSrcSize=%llu",
1969                (unsigned long long)pledgedSrcSize);
1970    {
1971        ZSTD_compressionParameters adjusted_cdict_cParams = cdict->matchState.cParams;
1972        unsigned const windowLog = params.cParams.windowLog;
1973        assert(windowLog != 0);
1974        /* Resize working context table params for input only, since the dict
1975         * has its own tables. */
1976        /* pledgedSrcSize == 0 means 0! */
1977
1978        if (cdict->matchState.dedicatedDictSearch) {
1979            ZSTD_dedicatedDictSearch_revertCParams(&adjusted_cdict_cParams);
1980        }
1981
1982        params.cParams = ZSTD_adjustCParams_internal(adjusted_cdict_cParams, pledgedSrcSize,
1983                                                     cdict->dictContentSize, ZSTD_cpm_attachDict);
1984        params.cParams.windowLog = windowLog;
1985        params.useRowMatchFinder = cdict->useRowMatchFinder;    /* cdict overrides */
1986        FORWARD_IF_ERROR(ZSTD_resetCCtx_internal(cctx, &params, pledgedSrcSize,
1987                                                 /* loadedDictSize */ 0,
1988                                                 ZSTDcrp_makeClean, zbuff), "");
1989        assert(cctx->appliedParams.cParams.strategy == adjusted_cdict_cParams.strategy);
1990    }
1991
1992    {   const U32 cdictEnd = (U32)( cdict->matchState.window.nextSrc
1993                                  - cdict->matchState.window.base);
1994        const U32 cdictLen = cdictEnd - cdict->matchState.window.dictLimit;
1995        if (cdictLen == 0) {
1996            /* don't even attach dictionaries with no contents */
1997            DEBUGLOG(4, "skipping attaching empty dictionary");
1998        } else {
1999            DEBUGLOG(4, "attaching dictionary into context");
2000            cctx->blockState.matchState.dictMatchState = &cdict->matchState;
2001
2002            /* prep working match state so dict matches never have negative indices
2003             * when they are translated to the working context's index space. */
2004            if (cctx->blockState.matchState.window.dictLimit < cdictEnd) {
2005                cctx->blockState.matchState.window.nextSrc =
2006                    cctx->blockState.matchState.window.base + cdictEnd;
2007                ZSTD_window_clear(&cctx->blockState.matchState.window);
2008            }
2009            /* loadedDictEnd is expressed within the referential of the active context */
2010            cctx->blockState.matchState.loadedDictEnd = cctx->blockState.matchState.window.dictLimit;
2011    }   }
2012
2013    cctx->dictID = cdict->dictID;
2014    cctx->dictContentSize = cdict->dictContentSize;
2015
2016    /* copy block state */
2017    ZSTD_memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
2018
2019    return 0;
2020}
2021
2022static size_t ZSTD_resetCCtx_byCopyingCDict(ZSTD_CCtx* cctx,
2023                            const ZSTD_CDict* cdict,
2024                            ZSTD_CCtx_params params,
2025                            U64 pledgedSrcSize,
2026                            ZSTD_buffered_policy_e zbuff)
2027{
2028    const ZSTD_compressionParameters *cdict_cParams = &cdict->matchState.cParams;
2029
2030    assert(!cdict->matchState.dedicatedDictSearch);
2031    DEBUGLOG(4, "ZSTD_resetCCtx_byCopyingCDict() pledgedSrcSize=%llu",
2032                (unsigned long long)pledgedSrcSize);
2033
2034    {   unsigned const windowLog = params.cParams.windowLog;
2035        assert(windowLog != 0);
2036        /* Copy only compression parameters related to tables. */
2037        params.cParams = *cdict_cParams;
2038        params.cParams.windowLog = windowLog;
2039        params.useRowMatchFinder = cdict->useRowMatchFinder;
2040        FORWARD_IF_ERROR(ZSTD_resetCCtx_internal(cctx, &params, pledgedSrcSize,
2041                                                 /* loadedDictSize */ 0,
2042                                                 ZSTDcrp_leaveDirty, zbuff), "");
2043        assert(cctx->appliedParams.cParams.strategy == cdict_cParams->strategy);
2044        assert(cctx->appliedParams.cParams.hashLog == cdict_cParams->hashLog);
2045        assert(cctx->appliedParams.cParams.chainLog == cdict_cParams->chainLog);
2046    }
2047
2048    ZSTD_cwksp_mark_tables_dirty(&cctx->workspace);
2049    assert(params.useRowMatchFinder != ZSTD_ps_auto);
2050
2051    /* copy tables */
2052    {   size_t const chainSize = ZSTD_allocateChainTable(cdict_cParams->strategy, cdict->useRowMatchFinder, 0 /* DDS guaranteed disabled */)
2053                                                            ? ((size_t)1 << cdict_cParams->chainLog)
2054                                                            : 0;
2055        size_t const hSize =  (size_t)1 << cdict_cParams->hashLog;
2056
2057        ZSTD_memcpy(cctx->blockState.matchState.hashTable,
2058               cdict->matchState.hashTable,
2059               hSize * sizeof(U32));
2060        /* Do not copy cdict's chainTable if cctx has parameters such that it would not use chainTable */
2061        if (ZSTD_allocateChainTable(cctx->appliedParams.cParams.strategy, cctx->appliedParams.useRowMatchFinder, 0 /* forDDSDict */)) {
2062            ZSTD_memcpy(cctx->blockState.matchState.chainTable,
2063               cdict->matchState.chainTable,
2064               chainSize * sizeof(U32));
2065        }
2066        /* copy tag table */
2067        if (ZSTD_rowMatchFinderUsed(cdict_cParams->strategy, cdict->useRowMatchFinder)) {
2068            size_t const tagTableSize = hSize*sizeof(U16);
2069            ZSTD_memcpy(cctx->blockState.matchState.tagTable,
2070                cdict->matchState.tagTable,
2071                tagTableSize);
2072        }
2073    }
2074
2075    /* Zero the hashTable3, since the cdict never fills it */
2076    {   int const h3log = cctx->blockState.matchState.hashLog3;
2077        size_t const h3Size = h3log ? ((size_t)1 << h3log) : 0;
2078        assert(cdict->matchState.hashLog3 == 0);
2079        ZSTD_memset(cctx->blockState.matchState.hashTable3, 0, h3Size * sizeof(U32));
2080    }
2081
2082    ZSTD_cwksp_mark_tables_clean(&cctx->workspace);
2083
2084    /* copy dictionary offsets */
2085    {   ZSTD_matchState_t const* srcMatchState = &cdict->matchState;
2086        ZSTD_matchState_t* dstMatchState = &cctx->blockState.matchState;
2087        dstMatchState->window       = srcMatchState->window;
2088        dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
2089        dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
2090    }
2091
2092    cctx->dictID = cdict->dictID;
2093    cctx->dictContentSize = cdict->dictContentSize;
2094
2095    /* copy block state */
2096    ZSTD_memcpy(cctx->blockState.prevCBlock, &cdict->cBlockState, sizeof(cdict->cBlockState));
2097
2098    return 0;
2099}
2100
2101/* We have a choice between copying the dictionary context into the working
2102 * context, or referencing the dictionary context from the working context
2103 * in-place. We decide here which strategy to use. */
2104static size_t ZSTD_resetCCtx_usingCDict(ZSTD_CCtx* cctx,
2105                            const ZSTD_CDict* cdict,
2106                            const ZSTD_CCtx_params* params,
2107                            U64 pledgedSrcSize,
2108                            ZSTD_buffered_policy_e zbuff)
2109{
2110
2111    DEBUGLOG(4, "ZSTD_resetCCtx_usingCDict (pledgedSrcSize=%u)",
2112                (unsigned)pledgedSrcSize);
2113
2114    if (ZSTD_shouldAttachDict(cdict, params, pledgedSrcSize)) {
2115        return ZSTD_resetCCtx_byAttachingCDict(
2116            cctx, cdict, *params, pledgedSrcSize, zbuff);
2117    } else {
2118        return ZSTD_resetCCtx_byCopyingCDict(
2119            cctx, cdict, *params, pledgedSrcSize, zbuff);
2120    }
2121}
2122
2123/*! ZSTD_copyCCtx_internal() :
2124 *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
2125 *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
2126 *  The "context", in this case, refers to the hash and chain tables,
2127 *  entropy tables, and dictionary references.
2128 * `windowLog` value is enforced if != 0, otherwise value is copied from srcCCtx.
2129 * @return : 0, or an error code */
2130static size_t ZSTD_copyCCtx_internal(ZSTD_CCtx* dstCCtx,
2131                            const ZSTD_CCtx* srcCCtx,
2132                            ZSTD_frameParameters fParams,
2133                            U64 pledgedSrcSize,
2134                            ZSTD_buffered_policy_e zbuff)
2135{
2136    RETURN_ERROR_IF(srcCCtx->stage!=ZSTDcs_init, stage_wrong,
2137                    "Can't copy a ctx that's not in init stage.");
2138    DEBUGLOG(5, "ZSTD_copyCCtx_internal");
2139    ZSTD_memcpy(&dstCCtx->customMem, &srcCCtx->customMem, sizeof(ZSTD_customMem));
2140    {   ZSTD_CCtx_params params = dstCCtx->requestedParams;
2141        /* Copy only compression parameters related to tables. */
2142        params.cParams = srcCCtx->appliedParams.cParams;
2143        assert(srcCCtx->appliedParams.useRowMatchFinder != ZSTD_ps_auto);
2144        assert(srcCCtx->appliedParams.useBlockSplitter != ZSTD_ps_auto);
2145        assert(srcCCtx->appliedParams.ldmParams.enableLdm != ZSTD_ps_auto);
2146        params.useRowMatchFinder = srcCCtx->appliedParams.useRowMatchFinder;
2147        params.useBlockSplitter = srcCCtx->appliedParams.useBlockSplitter;
2148        params.ldmParams = srcCCtx->appliedParams.ldmParams;
2149        params.fParams = fParams;
2150        ZSTD_resetCCtx_internal(dstCCtx, &params, pledgedSrcSize,
2151                                /* loadedDictSize */ 0,
2152                                ZSTDcrp_leaveDirty, zbuff);
2153        assert(dstCCtx->appliedParams.cParams.windowLog == srcCCtx->appliedParams.cParams.windowLog);
2154        assert(dstCCtx->appliedParams.cParams.strategy == srcCCtx->appliedParams.cParams.strategy);
2155        assert(dstCCtx->appliedParams.cParams.hashLog == srcCCtx->appliedParams.cParams.hashLog);
2156        assert(dstCCtx->appliedParams.cParams.chainLog == srcCCtx->appliedParams.cParams.chainLog);
2157        assert(dstCCtx->blockState.matchState.hashLog3 == srcCCtx->blockState.matchState.hashLog3);
2158    }
2159
2160    ZSTD_cwksp_mark_tables_dirty(&dstCCtx->workspace);
2161
2162    /* copy tables */
2163    {   size_t const chainSize = ZSTD_allocateChainTable(srcCCtx->appliedParams.cParams.strategy,
2164                                                         srcCCtx->appliedParams.useRowMatchFinder,
2165                                                         0 /* forDDSDict */)
2166                                    ? ((size_t)1 << srcCCtx->appliedParams.cParams.chainLog)
2167                                    : 0;
2168        size_t const hSize =  (size_t)1 << srcCCtx->appliedParams.cParams.hashLog;
2169        int const h3log = srcCCtx->blockState.matchState.hashLog3;
2170        size_t const h3Size = h3log ? ((size_t)1 << h3log) : 0;
2171
2172        ZSTD_memcpy(dstCCtx->blockState.matchState.hashTable,
2173               srcCCtx->blockState.matchState.hashTable,
2174               hSize * sizeof(U32));
2175        ZSTD_memcpy(dstCCtx->blockState.matchState.chainTable,
2176               srcCCtx->blockState.matchState.chainTable,
2177               chainSize * sizeof(U32));
2178        ZSTD_memcpy(dstCCtx->blockState.matchState.hashTable3,
2179               srcCCtx->blockState.matchState.hashTable3,
2180               h3Size * sizeof(U32));
2181    }
2182
2183    ZSTD_cwksp_mark_tables_clean(&dstCCtx->workspace);
2184
2185    /* copy dictionary offsets */
2186    {
2187        const ZSTD_matchState_t* srcMatchState = &srcCCtx->blockState.matchState;
2188        ZSTD_matchState_t* dstMatchState = &dstCCtx->blockState.matchState;
2189        dstMatchState->window       = srcMatchState->window;
2190        dstMatchState->nextToUpdate = srcMatchState->nextToUpdate;
2191        dstMatchState->loadedDictEnd= srcMatchState->loadedDictEnd;
2192    }
2193    dstCCtx->dictID = srcCCtx->dictID;
2194    dstCCtx->dictContentSize = srcCCtx->dictContentSize;
2195
2196    /* copy block state */
2197    ZSTD_memcpy(dstCCtx->blockState.prevCBlock, srcCCtx->blockState.prevCBlock, sizeof(*srcCCtx->blockState.prevCBlock));
2198
2199    return 0;
2200}
2201
2202/*! ZSTD_copyCCtx() :
2203 *  Duplicate an existing context `srcCCtx` into another one `dstCCtx`.
2204 *  Only works during stage ZSTDcs_init (i.e. after creation, but before first call to ZSTD_compressContinue()).
2205 *  pledgedSrcSize==0 means "unknown".
2206*   @return : 0, or an error code */
2207size_t ZSTD_copyCCtx(ZSTD_CCtx* dstCCtx, const ZSTD_CCtx* srcCCtx, unsigned long long pledgedSrcSize)
2208{
2209    ZSTD_frameParameters fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
2210    ZSTD_buffered_policy_e const zbuff = srcCCtx->bufferedPolicy;
2211    ZSTD_STATIC_ASSERT((U32)ZSTDb_buffered==1);
2212    if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;
2213    fParams.contentSizeFlag = (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN);
2214
2215    return ZSTD_copyCCtx_internal(dstCCtx, srcCCtx,
2216                                fParams, pledgedSrcSize,
2217                                zbuff);
2218}
2219
2220
2221#define ZSTD_ROWSIZE 16
2222/*! ZSTD_reduceTable() :
2223 *  reduce table indexes by `reducerValue`, or squash to zero.
2224 *  PreserveMark preserves "unsorted mark" for btlazy2 strategy.
2225 *  It must be set to a clear 0/1 value, to remove branch during inlining.
2226 *  Presume table size is a multiple of ZSTD_ROWSIZE
2227 *  to help auto-vectorization */
2228FORCE_INLINE_TEMPLATE void
2229ZSTD_reduceTable_internal (U32* const table, U32 const size, U32 const reducerValue, int const preserveMark)
2230{
2231    int const nbRows = (int)size / ZSTD_ROWSIZE;
2232    int cellNb = 0;
2233    int rowNb;
2234    /* Protect special index values < ZSTD_WINDOW_START_INDEX. */
2235    U32 const reducerThreshold = reducerValue + ZSTD_WINDOW_START_INDEX;
2236    assert((size & (ZSTD_ROWSIZE-1)) == 0);  /* multiple of ZSTD_ROWSIZE */
2237    assert(size < (1U<<31));   /* can be casted to int */
2238
2239
2240    for (rowNb=0 ; rowNb < nbRows ; rowNb++) {
2241        int column;
2242        for (column=0; column<ZSTD_ROWSIZE; column++) {
2243            U32 newVal;
2244            if (preserveMark && table[cellNb] == ZSTD_DUBT_UNSORTED_MARK) {
2245                /* This write is pointless, but is required(?) for the compiler
2246                 * to auto-vectorize the loop. */
2247                newVal = ZSTD_DUBT_UNSORTED_MARK;
2248            } else if (table[cellNb] < reducerThreshold) {
2249                newVal = 0;
2250            } else {
2251                newVal = table[cellNb] - reducerValue;
2252            }
2253            table[cellNb] = newVal;
2254            cellNb++;
2255    }   }
2256}
2257
2258static void ZSTD_reduceTable(U32* const table, U32 const size, U32 const reducerValue)
2259{
2260    ZSTD_reduceTable_internal(table, size, reducerValue, 0);
2261}
2262
2263static void ZSTD_reduceTable_btlazy2(U32* const table, U32 const size, U32 const reducerValue)
2264{
2265    ZSTD_reduceTable_internal(table, size, reducerValue, 1);
2266}
2267
2268/*! ZSTD_reduceIndex() :
2269*   rescale all indexes to avoid future overflow (indexes are U32) */
2270static void ZSTD_reduceIndex (ZSTD_matchState_t* ms, ZSTD_CCtx_params const* params, const U32 reducerValue)
2271{
2272    {   U32 const hSize = (U32)1 << params->cParams.hashLog;
2273        ZSTD_reduceTable(ms->hashTable, hSize, reducerValue);
2274    }
2275
2276    if (ZSTD_allocateChainTable(params->cParams.strategy, params->useRowMatchFinder, (U32)ms->dedicatedDictSearch)) {
2277        U32 const chainSize = (U32)1 << params->cParams.chainLog;
2278        if (params->cParams.strategy == ZSTD_btlazy2)
2279            ZSTD_reduceTable_btlazy2(ms->chainTable, chainSize, reducerValue);
2280        else
2281            ZSTD_reduceTable(ms->chainTable, chainSize, reducerValue);
2282    }
2283
2284    if (ms->hashLog3) {
2285        U32 const h3Size = (U32)1 << ms->hashLog3;
2286        ZSTD_reduceTable(ms->hashTable3, h3Size, reducerValue);
2287    }
2288}
2289
2290
2291/*-*******************************************************
2292*  Block entropic compression
2293*********************************************************/
2294
2295/* See doc/zstd_compression_format.md for detailed format description */
2296
2297void ZSTD_seqToCodes(const seqStore_t* seqStorePtr)
2298{
2299    const seqDef* const sequences = seqStorePtr->sequencesStart;
2300    BYTE* const llCodeTable = seqStorePtr->llCode;
2301    BYTE* const ofCodeTable = seqStorePtr->ofCode;
2302    BYTE* const mlCodeTable = seqStorePtr->mlCode;
2303    U32 const nbSeq = (U32)(seqStorePtr->sequences - seqStorePtr->sequencesStart);
2304    U32 u;
2305    assert(nbSeq <= seqStorePtr->maxNbSeq);
2306    for (u=0; u<nbSeq; u++) {
2307        U32 const llv = sequences[u].litLength;
2308        U32 const mlv = sequences[u].mlBase;
2309        llCodeTable[u] = (BYTE)ZSTD_LLcode(llv);
2310        ofCodeTable[u] = (BYTE)ZSTD_highbit32(sequences[u].offBase);
2311        mlCodeTable[u] = (BYTE)ZSTD_MLcode(mlv);
2312    }
2313    if (seqStorePtr->longLengthType==ZSTD_llt_literalLength)
2314        llCodeTable[seqStorePtr->longLengthPos] = MaxLL;
2315    if (seqStorePtr->longLengthType==ZSTD_llt_matchLength)
2316        mlCodeTable[seqStorePtr->longLengthPos] = MaxML;
2317}
2318
2319/* ZSTD_useTargetCBlockSize():
2320 * Returns if target compressed block size param is being used.
2321 * If used, compression will do best effort to make a compressed block size to be around targetCBlockSize.
2322 * Returns 1 if true, 0 otherwise. */
2323static int ZSTD_useTargetCBlockSize(const ZSTD_CCtx_params* cctxParams)
2324{
2325    DEBUGLOG(5, "ZSTD_useTargetCBlockSize (targetCBlockSize=%zu)", cctxParams->targetCBlockSize);
2326    return (cctxParams->targetCBlockSize != 0);
2327}
2328
2329/* ZSTD_blockSplitterEnabled():
2330 * Returns if block splitting param is being used
2331 * If used, compression will do best effort to split a block in order to improve compression ratio.
2332 * At the time this function is called, the parameter must be finalized.
2333 * Returns 1 if true, 0 otherwise. */
2334static int ZSTD_blockSplitterEnabled(ZSTD_CCtx_params* cctxParams)
2335{
2336    DEBUGLOG(5, "ZSTD_blockSplitterEnabled (useBlockSplitter=%d)", cctxParams->useBlockSplitter);
2337    assert(cctxParams->useBlockSplitter != ZSTD_ps_auto);
2338    return (cctxParams->useBlockSplitter == ZSTD_ps_enable);
2339}
2340
2341/* Type returned by ZSTD_buildSequencesStatistics containing finalized symbol encoding types
2342 * and size of the sequences statistics
2343 */
2344typedef struct {
2345    U32 LLtype;
2346    U32 Offtype;
2347    U32 MLtype;
2348    size_t size;
2349    size_t lastCountSize; /* Accounts for bug in 1.3.4. More detail in ZSTD_entropyCompressSeqStore_internal() */
2350} ZSTD_symbolEncodingTypeStats_t;
2351
2352/* ZSTD_buildSequencesStatistics():
2353 * Returns a ZSTD_symbolEncodingTypeStats_t, or a zstd error code in the `size` field.
2354 * Modifies `nextEntropy` to have the appropriate values as a side effect.
2355 * nbSeq must be greater than 0.
2356 *
2357 * entropyWkspSize must be of size at least ENTROPY_WORKSPACE_SIZE - (MaxSeq + 1)*sizeof(U32)
2358 */
2359static ZSTD_symbolEncodingTypeStats_t
2360ZSTD_buildSequencesStatistics(seqStore_t* seqStorePtr, size_t nbSeq,
2361                        const ZSTD_fseCTables_t* prevEntropy, ZSTD_fseCTables_t* nextEntropy,
2362                              BYTE* dst, const BYTE* const dstEnd,
2363                              ZSTD_strategy strategy, unsigned* countWorkspace,
2364                              void* entropyWorkspace, size_t entropyWkspSize) {
2365    BYTE* const ostart = dst;
2366    const BYTE* const oend = dstEnd;
2367    BYTE* op = ostart;
2368    FSE_CTable* CTable_LitLength = nextEntropy->litlengthCTable;
2369    FSE_CTable* CTable_OffsetBits = nextEntropy->offcodeCTable;
2370    FSE_CTable* CTable_MatchLength = nextEntropy->matchlengthCTable;
2371    const BYTE* const ofCodeTable = seqStorePtr->ofCode;
2372    const BYTE* const llCodeTable = seqStorePtr->llCode;
2373    const BYTE* const mlCodeTable = seqStorePtr->mlCode;
2374    ZSTD_symbolEncodingTypeStats_t stats;
2375
2376    stats.lastCountSize = 0;
2377    /* convert length/distances into codes */
2378    ZSTD_seqToCodes(seqStorePtr);
2379    assert(op <= oend);
2380    assert(nbSeq != 0); /* ZSTD_selectEncodingType() divides by nbSeq */
2381    /* build CTable for Literal Lengths */
2382    {   unsigned max = MaxLL;
2383        size_t const mostFrequent = HIST_countFast_wksp(countWorkspace, &max, llCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);   /* can't fail */
2384        DEBUGLOG(5, "Building LL table");
2385        nextEntropy->litlength_repeatMode = prevEntropy->litlength_repeatMode;
2386        stats.LLtype = ZSTD_selectEncodingType(&nextEntropy->litlength_repeatMode,
2387                                        countWorkspace, max, mostFrequent, nbSeq,
2388                                        LLFSELog, prevEntropy->litlengthCTable,
2389                                        LL_defaultNorm, LL_defaultNormLog,
2390                                        ZSTD_defaultAllowed, strategy);
2391        assert(set_basic < set_compressed && set_rle < set_compressed);
2392        assert(!(stats.LLtype < set_compressed && nextEntropy->litlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
2393        {   size_t const countSize = ZSTD_buildCTable(
2394                op, (size_t)(oend - op),
2395                CTable_LitLength, LLFSELog, (symbolEncodingType_e)stats.LLtype,
2396                countWorkspace, max, llCodeTable, nbSeq,
2397                LL_defaultNorm, LL_defaultNormLog, MaxLL,
2398                prevEntropy->litlengthCTable,
2399                sizeof(prevEntropy->litlengthCTable),
2400                entropyWorkspace, entropyWkspSize);
2401            if (ZSTD_isError(countSize)) {
2402                DEBUGLOG(3, "ZSTD_buildCTable for LitLens failed");
2403                stats.size = countSize;
2404                return stats;
2405            }
2406            if (stats.LLtype == set_compressed)
2407                stats.lastCountSize = countSize;
2408            op += countSize;
2409            assert(op <= oend);
2410    }   }
2411    /* build CTable for Offsets */
2412    {   unsigned max = MaxOff;
2413        size_t const mostFrequent = HIST_countFast_wksp(
2414            countWorkspace, &max, ofCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);  /* can't fail */
2415        /* We can only use the basic table if max <= DefaultMaxOff, otherwise the offsets are too large */
2416        ZSTD_defaultPolicy_e const defaultPolicy = (max <= DefaultMaxOff) ? ZSTD_defaultAllowed : ZSTD_defaultDisallowed;
2417        DEBUGLOG(5, "Building OF table");
2418        nextEntropy->offcode_repeatMode = prevEntropy->offcode_repeatMode;
2419        stats.Offtype = ZSTD_selectEncodingType(&nextEntropy->offcode_repeatMode,
2420                                        countWorkspace, max, mostFrequent, nbSeq,
2421                                        OffFSELog, prevEntropy->offcodeCTable,
2422                                        OF_defaultNorm, OF_defaultNormLog,
2423                                        defaultPolicy, strategy);
2424        assert(!(stats.Offtype < set_compressed && nextEntropy->offcode_repeatMode != FSE_repeat_none)); /* We don't copy tables */
2425        {   size_t const countSize = ZSTD_buildCTable(
2426                op, (size_t)(oend - op),
2427                CTable_OffsetBits, OffFSELog, (symbolEncodingType_e)stats.Offtype,
2428                countWorkspace, max, ofCodeTable, nbSeq,
2429                OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
2430                prevEntropy->offcodeCTable,
2431                sizeof(prevEntropy->offcodeCTable),
2432                entropyWorkspace, entropyWkspSize);
2433            if (ZSTD_isError(countSize)) {
2434                DEBUGLOG(3, "ZSTD_buildCTable for Offsets failed");
2435                stats.size = countSize;
2436                return stats;
2437            }
2438            if (stats.Offtype == set_compressed)
2439                stats.lastCountSize = countSize;
2440            op += countSize;
2441            assert(op <= oend);
2442    }   }
2443    /* build CTable for MatchLengths */
2444    {   unsigned max = MaxML;
2445        size_t const mostFrequent = HIST_countFast_wksp(
2446            countWorkspace, &max, mlCodeTable, nbSeq, entropyWorkspace, entropyWkspSize);   /* can't fail */
2447        DEBUGLOG(5, "Building ML table (remaining space : %i)", (int)(oend-op));
2448        nextEntropy->matchlength_repeatMode = prevEntropy->matchlength_repeatMode;
2449        stats.MLtype = ZSTD_selectEncodingType(&nextEntropy->matchlength_repeatMode,
2450                                        countWorkspace, max, mostFrequent, nbSeq,
2451                                        MLFSELog, prevEntropy->matchlengthCTable,
2452                                        ML_defaultNorm, ML_defaultNormLog,
2453                                        ZSTD_defaultAllowed, strategy);
2454        assert(!(stats.MLtype < set_compressed && nextEntropy->matchlength_repeatMode != FSE_repeat_none)); /* We don't copy tables */
2455        {   size_t const countSize = ZSTD_buildCTable(
2456                op, (size_t)(oend - op),
2457                CTable_MatchLength, MLFSELog, (symbolEncodingType_e)stats.MLtype,
2458                countWorkspace, max, mlCodeTable, nbSeq,
2459                ML_defaultNorm, ML_defaultNormLog, MaxML,
2460                prevEntropy->matchlengthCTable,
2461                sizeof(prevEntropy->matchlengthCTable),
2462                entropyWorkspace, entropyWkspSize);
2463            if (ZSTD_isError(countSize)) {
2464                DEBUGLOG(3, "ZSTD_buildCTable for MatchLengths failed");
2465                stats.size = countSize;
2466                return stats;
2467            }
2468            if (stats.MLtype == set_compressed)
2469                stats.lastCountSize = countSize;
2470            op += countSize;
2471            assert(op <= oend);
2472    }   }
2473    stats.size = (size_t)(op-ostart);
2474    return stats;
2475}
2476
2477/* ZSTD_entropyCompressSeqStore_internal():
2478 * compresses both literals and sequences
2479 * Returns compressed size of block, or a zstd error.
2480 */
2481#define SUSPECT_UNCOMPRESSIBLE_LITERAL_RATIO 20
2482MEM_STATIC size_t
2483ZSTD_entropyCompressSeqStore_internal(seqStore_t* seqStorePtr,
2484                          const ZSTD_entropyCTables_t* prevEntropy,
2485                                ZSTD_entropyCTables_t* nextEntropy,
2486                          const ZSTD_CCtx_params* cctxParams,
2487                                void* dst, size_t dstCapacity,
2488                                void* entropyWorkspace, size_t entropyWkspSize,
2489                          const int bmi2)
2490{
2491    const int longOffsets = cctxParams->cParams.windowLog > STREAM_ACCUMULATOR_MIN;
2492    ZSTD_strategy const strategy = cctxParams->cParams.strategy;
2493    unsigned* count = (unsigned*)entropyWorkspace;
2494    FSE_CTable* CTable_LitLength = nextEntropy->fse.litlengthCTable;
2495    FSE_CTable* CTable_OffsetBits = nextEntropy->fse.offcodeCTable;
2496    FSE_CTable* CTable_MatchLength = nextEntropy->fse.matchlengthCTable;
2497    const seqDef* const sequences = seqStorePtr->sequencesStart;
2498    const size_t nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
2499    const BYTE* const ofCodeTable = seqStorePtr->ofCode;
2500    const BYTE* const llCodeTable = seqStorePtr->llCode;
2501    const BYTE* const mlCodeTable = seqStorePtr->mlCode;
2502    BYTE* const ostart = (BYTE*)dst;
2503    BYTE* const oend = ostart + dstCapacity;
2504    BYTE* op = ostart;
2505    size_t lastCountSize;
2506
2507    entropyWorkspace = count + (MaxSeq + 1);
2508    entropyWkspSize -= (MaxSeq + 1) * sizeof(*count);
2509
2510    DEBUGLOG(4, "ZSTD_entropyCompressSeqStore_internal (nbSeq=%zu)", nbSeq);
2511    ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<<MAX(MLFSELog,LLFSELog)));
2512    assert(entropyWkspSize >= HUF_WORKSPACE_SIZE);
2513
2514    /* Compress literals */
2515    {   const BYTE* const literals = seqStorePtr->litStart;
2516        size_t const numSequences = seqStorePtr->sequences - seqStorePtr->sequencesStart;
2517        size_t const numLiterals = seqStorePtr->lit - seqStorePtr->litStart;
2518        /* Base suspicion of uncompressibility on ratio of literals to sequences */
2519        unsigned const suspectUncompressible = (numSequences == 0) || (numLiterals / numSequences >= SUSPECT_UNCOMPRESSIBLE_LITERAL_RATIO);
2520        size_t const litSize = (size_t)(seqStorePtr->lit - literals);
2521        size_t const cSize = ZSTD_compressLiterals(
2522                                    &prevEntropy->huf, &nextEntropy->huf,
2523                                    cctxParams->cParams.strategy,
2524                                    ZSTD_literalsCompressionIsDisabled(cctxParams),
2525                                    op, dstCapacity,
2526                                    literals, litSize,
2527                                    entropyWorkspace, entropyWkspSize,
2528                                    bmi2, suspectUncompressible);
2529        FORWARD_IF_ERROR(cSize, "ZSTD_compressLiterals failed");
2530        assert(cSize <= dstCapacity);
2531        op += cSize;
2532    }
2533
2534    /* Sequences Header */
2535    RETURN_ERROR_IF((oend-op) < 3 /*max nbSeq Size*/ + 1 /*seqHead*/,
2536                    dstSize_tooSmall, "Can't fit seq hdr in output buf!");
2537    if (nbSeq < 128) {
2538        *op++ = (BYTE)nbSeq;
2539    } else if (nbSeq < LONGNBSEQ) {
2540        op[0] = (BYTE)((nbSeq>>8) + 0x80);
2541        op[1] = (BYTE)nbSeq;
2542        op+=2;
2543    } else {
2544        op[0]=0xFF;
2545        MEM_writeLE16(op+1, (U16)(nbSeq - LONGNBSEQ));
2546        op+=3;
2547    }
2548    assert(op <= oend);
2549    if (nbSeq==0) {
2550        /* Copy the old tables over as if we repeated them */
2551        ZSTD_memcpy(&nextEntropy->fse, &prevEntropy->fse, sizeof(prevEntropy->fse));
2552        return (size_t)(op - ostart);
2553    }
2554    {
2555        ZSTD_symbolEncodingTypeStats_t stats;
2556        BYTE* seqHead = op++;
2557        /* build stats for sequences */
2558        stats = ZSTD_buildSequencesStatistics(seqStorePtr, nbSeq,
2559                                             &prevEntropy->fse, &nextEntropy->fse,
2560                                              op, oend,
2561                                              strategy, count,
2562                                              entropyWorkspace, entropyWkspSize);
2563        FORWARD_IF_ERROR(stats.size, "ZSTD_buildSequencesStatistics failed!");
2564        *seqHead = (BYTE)((stats.LLtype<<6) + (stats.Offtype<<4) + (stats.MLtype<<2));
2565        lastCountSize = stats.lastCountSize;
2566        op += stats.size;
2567    }
2568
2569    {   size_t const bitstreamSize = ZSTD_encodeSequences(
2570                                        op, (size_t)(oend - op),
2571                                        CTable_MatchLength, mlCodeTable,
2572                                        CTable_OffsetBits, ofCodeTable,
2573                                        CTable_LitLength, llCodeTable,
2574                                        sequences, nbSeq,
2575                                        longOffsets, bmi2);
2576        FORWARD_IF_ERROR(bitstreamSize, "ZSTD_encodeSequences failed");
2577        op += bitstreamSize;
2578        assert(op <= oend);
2579        /* zstd versions <= 1.3.4 mistakenly report corruption when
2580         * FSE_readNCount() receives a buffer < 4 bytes.
2581         * Fixed by https://github.com/facebook/zstd/pull/1146.
2582         * This can happen when the last set_compressed table present is 2
2583         * bytes and the bitstream is only one byte.
2584         * In this exceedingly rare case, we will simply emit an uncompressed
2585         * block, since it isn't worth optimizing.
2586         */
2587        if (lastCountSize && (lastCountSize + bitstreamSize) < 4) {
2588            /* lastCountSize >= 2 && bitstreamSize > 0 ==> lastCountSize == 3 */
2589            assert(lastCountSize + bitstreamSize == 3);
2590            DEBUGLOG(5, "Avoiding bug in zstd decoder in versions <= 1.3.4 by "
2591                        "emitting an uncompressed block.");
2592            return 0;
2593        }
2594    }
2595
2596    DEBUGLOG(5, "compressed block size : %u", (unsigned)(op - ostart));
2597    return (size_t)(op - ostart);
2598}
2599
2600MEM_STATIC size_t
2601ZSTD_entropyCompressSeqStore(seqStore_t* seqStorePtr,
2602                       const ZSTD_entropyCTables_t* prevEntropy,
2603                             ZSTD_entropyCTables_t* nextEntropy,
2604                       const ZSTD_CCtx_params* cctxParams,
2605                             void* dst, size_t dstCapacity,
2606                             size_t srcSize,
2607                             void* entropyWorkspace, size_t entropyWkspSize,
2608                             int bmi2)
2609{
2610    size_t const cSize = ZSTD_entropyCompressSeqStore_internal(
2611                            seqStorePtr, prevEntropy, nextEntropy, cctxParams,
2612                            dst, dstCapacity,
2613                            entropyWorkspace, entropyWkspSize, bmi2);
2614    if (cSize == 0) return 0;
2615    /* When srcSize <= dstCapacity, there is enough space to write a raw uncompressed block.
2616     * Since we ran out of space, block must be not compressible, so fall back to raw uncompressed block.
2617     */
2618    if ((cSize == ERROR(dstSize_tooSmall)) & (srcSize <= dstCapacity))
2619        return 0;  /* block not compressed */
2620    FORWARD_IF_ERROR(cSize, "ZSTD_entropyCompressSeqStore_internal failed");
2621
2622    /* Check compressibility */
2623    {   size_t const maxCSize = srcSize - ZSTD_minGain(srcSize, cctxParams->cParams.strategy);
2624        if (cSize >= maxCSize) return 0;  /* block not compressed */
2625    }
2626    DEBUGLOG(4, "ZSTD_entropyCompressSeqStore() cSize: %zu", cSize);
2627    return cSize;
2628}
2629
2630/* ZSTD_selectBlockCompressor() :
2631 * Not static, but internal use only (used by long distance matcher)
2632 * assumption : strat is a valid strategy */
2633ZSTD_blockCompressor ZSTD_selectBlockCompressor(ZSTD_strategy strat, ZSTD_paramSwitch_e useRowMatchFinder, ZSTD_dictMode_e dictMode)
2634{
2635    static const ZSTD_blockCompressor blockCompressor[4][ZSTD_STRATEGY_MAX+1] = {
2636        { ZSTD_compressBlock_fast  /* default for 0 */,
2637          ZSTD_compressBlock_fast,
2638          ZSTD_compressBlock_doubleFast,
2639          ZSTD_compressBlock_greedy,
2640          ZSTD_compressBlock_lazy,
2641          ZSTD_compressBlock_lazy2,
2642          ZSTD_compressBlock_btlazy2,
2643          ZSTD_compressBlock_btopt,
2644          ZSTD_compressBlock_btultra,
2645          ZSTD_compressBlock_btultra2 },
2646        { ZSTD_compressBlock_fast_extDict  /* default for 0 */,
2647          ZSTD_compressBlock_fast_extDict,
2648          ZSTD_compressBlock_doubleFast_extDict,
2649          ZSTD_compressBlock_greedy_extDict,
2650          ZSTD_compressBlock_lazy_extDict,
2651          ZSTD_compressBlock_lazy2_extDict,
2652          ZSTD_compressBlock_btlazy2_extDict,
2653          ZSTD_compressBlock_btopt_extDict,
2654          ZSTD_compressBlock_btultra_extDict,
2655          ZSTD_compressBlock_btultra_extDict },
2656        { ZSTD_compressBlock_fast_dictMatchState  /* default for 0 */,
2657          ZSTD_compressBlock_fast_dictMatchState,
2658          ZSTD_compressBlock_doubleFast_dictMatchState,
2659          ZSTD_compressBlock_greedy_dictMatchState,
2660          ZSTD_compressBlock_lazy_dictMatchState,
2661          ZSTD_compressBlock_lazy2_dictMatchState,
2662          ZSTD_compressBlock_btlazy2_dictMatchState,
2663          ZSTD_compressBlock_btopt_dictMatchState,
2664          ZSTD_compressBlock_btultra_dictMatchState,
2665          ZSTD_compressBlock_btultra_dictMatchState },
2666        { NULL  /* default for 0 */,
2667          NULL,
2668          NULL,
2669          ZSTD_compressBlock_greedy_dedicatedDictSearch,
2670          ZSTD_compressBlock_lazy_dedicatedDictSearch,
2671          ZSTD_compressBlock_lazy2_dedicatedDictSearch,
2672          NULL,
2673          NULL,
2674          NULL,
2675          NULL }
2676    };
2677    ZSTD_blockCompressor selectedCompressor;
2678    ZSTD_STATIC_ASSERT((unsigned)ZSTD_fast == 1);
2679
2680    assert(ZSTD_cParam_withinBounds(ZSTD_c_strategy, strat));
2681    DEBUGLOG(4, "Selected block compressor: dictMode=%d strat=%d rowMatchfinder=%d", (int)dictMode, (int)strat, (int)useRowMatchFinder);
2682    if (ZSTD_rowMatchFinderUsed(strat, useRowMatchFinder)) {
2683        static const ZSTD_blockCompressor rowBasedBlockCompressors[4][3] = {
2684            { ZSTD_compressBlock_greedy_row,
2685            ZSTD_compressBlock_lazy_row,
2686            ZSTD_compressBlock_lazy2_row },
2687            { ZSTD_compressBlock_greedy_extDict_row,
2688            ZSTD_compressBlock_lazy_extDict_row,
2689            ZSTD_compressBlock_lazy2_extDict_row },
2690            { ZSTD_compressBlock_greedy_dictMatchState_row,
2691            ZSTD_compressBlock_lazy_dictMatchState_row,
2692            ZSTD_compressBlock_lazy2_dictMatchState_row },
2693            { ZSTD_compressBlock_greedy_dedicatedDictSearch_row,
2694            ZSTD_compressBlock_lazy_dedicatedDictSearch_row,
2695            ZSTD_compressBlock_lazy2_dedicatedDictSearch_row }
2696        };
2697        DEBUGLOG(4, "Selecting a row-based matchfinder");
2698        assert(useRowMatchFinder != ZSTD_ps_auto);
2699        selectedCompressor = rowBasedBlockCompressors[(int)dictMode][(int)strat - (int)ZSTD_greedy];
2700    } else {
2701        selectedCompressor = blockCompressor[(int)dictMode][(int)strat];
2702    }
2703    assert(selectedCompressor != NULL);
2704    return selectedCompressor;
2705}
2706
2707static void ZSTD_storeLastLiterals(seqStore_t* seqStorePtr,
2708                                   const BYTE* anchor, size_t lastLLSize)
2709{
2710    ZSTD_memcpy(seqStorePtr->lit, anchor, lastLLSize);
2711    seqStorePtr->lit += lastLLSize;
2712}
2713
2714void ZSTD_resetSeqStore(seqStore_t* ssPtr)
2715{
2716    ssPtr->lit = ssPtr->litStart;
2717    ssPtr->sequences = ssPtr->sequencesStart;
2718    ssPtr->longLengthType = ZSTD_llt_none;
2719}
2720
2721typedef enum { ZSTDbss_compress, ZSTDbss_noCompress } ZSTD_buildSeqStore_e;
2722
2723static size_t ZSTD_buildSeqStore(ZSTD_CCtx* zc, const void* src, size_t srcSize)
2724{
2725    ZSTD_matchState_t* const ms = &zc->blockState.matchState;
2726    DEBUGLOG(5, "ZSTD_buildSeqStore (srcSize=%zu)", srcSize);
2727    assert(srcSize <= ZSTD_BLOCKSIZE_MAX);
2728    /* Assert that we have correctly flushed the ctx params into the ms's copy */
2729    ZSTD_assertEqualCParams(zc->appliedParams.cParams, ms->cParams);
2730    if (srcSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) {
2731        if (zc->appliedParams.cParams.strategy >= ZSTD_btopt) {
2732            ZSTD_ldm_skipRawSeqStoreBytes(&zc->externSeqStore, srcSize);
2733        } else {
2734            ZSTD_ldm_skipSequences(&zc->externSeqStore, srcSize, zc->appliedParams.cParams.minMatch);
2735        }
2736        return ZSTDbss_noCompress; /* don't even attempt compression below a certain srcSize */
2737    }
2738    ZSTD_resetSeqStore(&(zc->seqStore));
2739    /* required for optimal parser to read stats from dictionary */
2740    ms->opt.symbolCosts = &zc->blockState.prevCBlock->entropy;
2741    /* tell the optimal parser how we expect to compress literals */
2742    ms->opt.literalCompressionMode = zc->appliedParams.literalCompressionMode;
2743    /* a gap between an attached dict and the current window is not safe,
2744     * they must remain adjacent,
2745     * and when that stops being the case, the dict must be unset */
2746    assert(ms->dictMatchState == NULL || ms->loadedDictEnd == ms->window.dictLimit);
2747
2748    /* limited update after a very long match */
2749    {   const BYTE* const base = ms->window.base;
2750        const BYTE* const istart = (const BYTE*)src;
2751        const U32 curr = (U32)(istart-base);
2752        if (sizeof(ptrdiff_t)==8) assert(istart - base < (ptrdiff_t)(U32)(-1));   /* ensure no overflow */
2753        if (curr > ms->nextToUpdate + 384)
2754            ms->nextToUpdate = curr - MIN(192, (U32)(curr - ms->nextToUpdate - 384));
2755    }
2756
2757    /* select and store sequences */
2758    {   ZSTD_dictMode_e const dictMode = ZSTD_matchState_dictMode(ms);
2759        size_t lastLLSize;
2760        {   int i;
2761            for (i = 0; i < ZSTD_REP_NUM; ++i)
2762                zc->blockState.nextCBlock->rep[i] = zc->blockState.prevCBlock->rep[i];
2763        }
2764        if (zc->externSeqStore.pos < zc->externSeqStore.size) {
2765            assert(zc->appliedParams.ldmParams.enableLdm == ZSTD_ps_disable);
2766            /* Updates ldmSeqStore.pos */
2767            lastLLSize =
2768                ZSTD_ldm_blockCompress(&zc->externSeqStore,
2769                                       ms, &zc->seqStore,
2770                                       zc->blockState.nextCBlock->rep,
2771                                       zc->appliedParams.useRowMatchFinder,
2772                                       src, srcSize);
2773            assert(zc->externSeqStore.pos <= zc->externSeqStore.size);
2774        } else if (zc->appliedParams.ldmParams.enableLdm == ZSTD_ps_enable) {
2775            rawSeqStore_t ldmSeqStore = kNullRawSeqStore;
2776
2777            ldmSeqStore.seq = zc->ldmSequences;
2778            ldmSeqStore.capacity = zc->maxNbLdmSequences;
2779            /* Updates ldmSeqStore.size */
2780            FORWARD_IF_ERROR(ZSTD_ldm_generateSequences(&zc->ldmState, &ldmSeqStore,
2781                                               &zc->appliedParams.ldmParams,
2782                                               src, srcSize), "");
2783            /* Updates ldmSeqStore.pos */
2784            lastLLSize =
2785                ZSTD_ldm_blockCompress(&ldmSeqStore,
2786                                       ms, &zc->seqStore,
2787                                       zc->blockState.nextCBlock->rep,
2788                                       zc->appliedParams.useRowMatchFinder,
2789                                       src, srcSize);
2790            assert(ldmSeqStore.pos == ldmSeqStore.size);
2791        } else {   /* not long range mode */
2792            ZSTD_blockCompressor const blockCompressor = ZSTD_selectBlockCompressor(zc->appliedParams.cParams.strategy,
2793                                                                                    zc->appliedParams.useRowMatchFinder,
2794                                                                                    dictMode);
2795            ms->ldmSeqStore = NULL;
2796            lastLLSize = blockCompressor(ms, &zc->seqStore, zc->blockState.nextCBlock->rep, src, srcSize);
2797        }
2798        {   const BYTE* const lastLiterals = (const BYTE*)src + srcSize - lastLLSize;
2799            ZSTD_storeLastLiterals(&zc->seqStore, lastLiterals, lastLLSize);
2800    }   }
2801    return ZSTDbss_compress;
2802}
2803
2804static void ZSTD_copyBlockSequences(ZSTD_CCtx* zc)
2805{
2806    const seqStore_t* seqStore = ZSTD_getSeqStore(zc);
2807    const seqDef* seqStoreSeqs = seqStore->sequencesStart;
2808    size_t seqStoreSeqSize = seqStore->sequences - seqStoreSeqs;
2809    size_t seqStoreLiteralsSize = (size_t)(seqStore->lit - seqStore->litStart);
2810    size_t literalsRead = 0;
2811    size_t lastLLSize;
2812
2813    ZSTD_Sequence* outSeqs = &zc->seqCollector.seqStart[zc->seqCollector.seqIndex];
2814    size_t i;
2815    repcodes_t updatedRepcodes;
2816
2817    assert(zc->seqCollector.seqIndex + 1 < zc->seqCollector.maxSequences);
2818    /* Ensure we have enough space for last literals "sequence" */
2819    assert(zc->seqCollector.maxSequences >= seqStoreSeqSize + 1);
2820    ZSTD_memcpy(updatedRepcodes.rep, zc->blockState.prevCBlock->rep, sizeof(repcodes_t));
2821    for (i = 0; i < seqStoreSeqSize; ++i) {
2822        U32 rawOffset = seqStoreSeqs[i].offBase - ZSTD_REP_NUM;
2823        outSeqs[i].litLength = seqStoreSeqs[i].litLength;
2824        outSeqs[i].matchLength = seqStoreSeqs[i].mlBase + MINMATCH;
2825        outSeqs[i].rep = 0;
2826
2827        if (i == seqStore->longLengthPos) {
2828            if (seqStore->longLengthType == ZSTD_llt_literalLength) {
2829                outSeqs[i].litLength += 0x10000;
2830            } else if (seqStore->longLengthType == ZSTD_llt_matchLength) {
2831                outSeqs[i].matchLength += 0x10000;
2832            }
2833        }
2834
2835        if (seqStoreSeqs[i].offBase <= ZSTD_REP_NUM) {
2836            /* Derive the correct offset corresponding to a repcode */
2837            outSeqs[i].rep = seqStoreSeqs[i].offBase;
2838            if (outSeqs[i].litLength != 0) {
2839                rawOffset = updatedRepcodes.rep[outSeqs[i].rep - 1];
2840            } else {
2841                if (outSeqs[i].rep == 3) {
2842                    rawOffset = updatedRepcodes.rep[0] - 1;
2843                } else {
2844                    rawOffset = updatedRepcodes.rep[outSeqs[i].rep];
2845                }
2846            }
2847        }
2848        outSeqs[i].offset = rawOffset;
2849        /* seqStoreSeqs[i].offset == offCode+1, and ZSTD_updateRep() expects offCode
2850           so we provide seqStoreSeqs[i].offset - 1 */
2851        ZSTD_updateRep(updatedRepcodes.rep,
2852                       seqStoreSeqs[i].offBase - 1,
2853                       seqStoreSeqs[i].litLength == 0);
2854        literalsRead += outSeqs[i].litLength;
2855    }
2856    /* Insert last literals (if any exist) in the block as a sequence with ml == off == 0.
2857     * If there are no last literals, then we'll emit (of: 0, ml: 0, ll: 0), which is a marker
2858     * for the block boundary, according to the API.
2859     */
2860    assert(seqStoreLiteralsSize >= literalsRead);
2861    lastLLSize = seqStoreLiteralsSize - literalsRead;
2862    outSeqs[i].litLength = (U32)lastLLSize;
2863    outSeqs[i].matchLength = outSeqs[i].offset = outSeqs[i].rep = 0;
2864    seqStoreSeqSize++;
2865    zc->seqCollector.seqIndex += seqStoreSeqSize;
2866}
2867
2868size_t ZSTD_generateSequences(ZSTD_CCtx* zc, ZSTD_Sequence* outSeqs,
2869                              size_t outSeqsSize, const void* src, size_t srcSize)
2870{
2871    const size_t dstCapacity = ZSTD_compressBound(srcSize);
2872    void* dst = ZSTD_customMalloc(dstCapacity, ZSTD_defaultCMem);
2873    SeqCollector seqCollector;
2874
2875    RETURN_ERROR_IF(dst == NULL, memory_allocation, "NULL pointer!");
2876
2877    seqCollector.collectSequences = 1;
2878    seqCollector.seqStart = outSeqs;
2879    seqCollector.seqIndex = 0;
2880    seqCollector.maxSequences = outSeqsSize;
2881    zc->seqCollector = seqCollector;
2882
2883    ZSTD_compress2(zc, dst, dstCapacity, src, srcSize);
2884    ZSTD_customFree(dst, ZSTD_defaultCMem);
2885    return zc->seqCollector.seqIndex;
2886}
2887
2888size_t ZSTD_mergeBlockDelimiters(ZSTD_Sequence* sequences, size_t seqsSize) {
2889    size_t in = 0;
2890    size_t out = 0;
2891    for (; in < seqsSize; ++in) {
2892        if (sequences[in].offset == 0 && sequences[in].matchLength == 0) {
2893            if (in != seqsSize - 1) {
2894                sequences[in+1].litLength += sequences[in].litLength;
2895            }
2896        } else {
2897            sequences[out] = sequences[in];
2898            ++out;
2899        }
2900    }
2901    return out;
2902}
2903
2904/* Unrolled loop to read four size_ts of input at a time. Returns 1 if is RLE, 0 if not. */
2905static int ZSTD_isRLE(const BYTE* src, size_t length) {
2906    const BYTE* ip = src;
2907    const BYTE value = ip[0];
2908    const size_t valueST = (size_t)((U64)value * 0x0101010101010101ULL);
2909    const size_t unrollSize = sizeof(size_t) * 4;
2910    const size_t unrollMask = unrollSize - 1;
2911    const size_t prefixLength = length & unrollMask;
2912    size_t i;
2913    size_t u;
2914    if (length == 1) return 1;
2915    /* Check if prefix is RLE first before using unrolled loop */
2916    if (prefixLength && ZSTD_count(ip+1, ip, ip+prefixLength) != prefixLength-1) {
2917        return 0;
2918    }
2919    for (i = prefixLength; i != length; i += unrollSize) {
2920        for (u = 0; u < unrollSize; u += sizeof(size_t)) {
2921            if (MEM_readST(ip + i + u) != valueST) {
2922                return 0;
2923            }
2924        }
2925    }
2926    return 1;
2927}
2928
2929/* Returns true if the given block may be RLE.
2930 * This is just a heuristic based on the compressibility.
2931 * It may return both false positives and false negatives.
2932 */
2933static int ZSTD_maybeRLE(seqStore_t const* seqStore)
2934{
2935    size_t const nbSeqs = (size_t)(seqStore->sequences - seqStore->sequencesStart);
2936    size_t const nbLits = (size_t)(seqStore->lit - seqStore->litStart);
2937
2938    return nbSeqs < 4 && nbLits < 10;
2939}
2940
2941static void ZSTD_blockState_confirmRepcodesAndEntropyTables(ZSTD_blockState_t* const bs)
2942{
2943    ZSTD_compressedBlockState_t* const tmp = bs->prevCBlock;
2944    bs->prevCBlock = bs->nextCBlock;
2945    bs->nextCBlock = tmp;
2946}
2947
2948/* Writes the block header */
2949static void writeBlockHeader(void* op, size_t cSize, size_t blockSize, U32 lastBlock) {
2950    U32 const cBlockHeader = cSize == 1 ?
2951                        lastBlock + (((U32)bt_rle)<<1) + (U32)(blockSize << 3) :
2952                        lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
2953    MEM_writeLE24(op, cBlockHeader);
2954    DEBUGLOG(3, "writeBlockHeader: cSize: %zu blockSize: %zu lastBlock: %u", cSize, blockSize, lastBlock);
2955}
2956
2957/* ZSTD_buildBlockEntropyStats_literals() :
2958 *  Builds entropy for the literals.
2959 *  Stores literals block type (raw, rle, compressed, repeat) and
2960 *  huffman description table to hufMetadata.
2961 *  Requires ENTROPY_WORKSPACE_SIZE workspace
2962 *  @return : size of huffman description table or error code */
2963static size_t ZSTD_buildBlockEntropyStats_literals(void* const src, size_t srcSize,
2964                                            const ZSTD_hufCTables_t* prevHuf,
2965                                                  ZSTD_hufCTables_t* nextHuf,
2966                                                  ZSTD_hufCTablesMetadata_t* hufMetadata,
2967                                                  const int literalsCompressionIsDisabled,
2968                                                  void* workspace, size_t wkspSize)
2969{
2970    BYTE* const wkspStart = (BYTE*)workspace;
2971    BYTE* const wkspEnd = wkspStart + wkspSize;
2972    BYTE* const countWkspStart = wkspStart;
2973    unsigned* const countWksp = (unsigned*)workspace;
2974    const size_t countWkspSize = (HUF_SYMBOLVALUE_MAX + 1) * sizeof(unsigned);
2975    BYTE* const nodeWksp = countWkspStart + countWkspSize;
2976    const size_t nodeWkspSize = wkspEnd-nodeWksp;
2977    unsigned maxSymbolValue = HUF_SYMBOLVALUE_MAX;
2978    unsigned huffLog = HUF_TABLELOG_DEFAULT;
2979    HUF_repeat repeat = prevHuf->repeatMode;
2980    DEBUGLOG(5, "ZSTD_buildBlockEntropyStats_literals (srcSize=%zu)", srcSize);
2981
2982    /* Prepare nextEntropy assuming reusing the existing table */
2983    ZSTD_memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
2984
2985    if (literalsCompressionIsDisabled) {
2986        DEBUGLOG(5, "set_basic - disabled");
2987        hufMetadata->hType = set_basic;
2988        return 0;
2989    }
2990
2991    /* small ? don't even attempt compression (speed opt) */
2992#ifndef COMPRESS_LITERALS_SIZE_MIN
2993#define COMPRESS_LITERALS_SIZE_MIN 63
2994#endif
2995    {   size_t const minLitSize = (prevHuf->repeatMode == HUF_repeat_valid) ? 6 : COMPRESS_LITERALS_SIZE_MIN;
2996        if (srcSize <= minLitSize) {
2997            DEBUGLOG(5, "set_basic - too small");
2998            hufMetadata->hType = set_basic;
2999            return 0;
3000        }
3001    }
3002
3003    /* Scan input and build symbol stats */
3004    {   size_t const largest = HIST_count_wksp (countWksp, &maxSymbolValue, (const BYTE*)src, srcSize, workspace, wkspSize);
3005        FORWARD_IF_ERROR(largest, "HIST_count_wksp failed");
3006        if (largest == srcSize) {
3007            DEBUGLOG(5, "set_rle");
3008            hufMetadata->hType = set_rle;
3009            return 0;
3010        }
3011        if (largest <= (srcSize >> 7)+4) {
3012            DEBUGLOG(5, "set_basic - no gain");
3013            hufMetadata->hType = set_basic;
3014            return 0;
3015        }
3016    }
3017
3018    /* Validate the previous Huffman table */
3019    if (repeat == HUF_repeat_check && !HUF_validateCTable((HUF_CElt const*)prevHuf->CTable, countWksp, maxSymbolValue)) {
3020        repeat = HUF_repeat_none;
3021    }
3022
3023    /* Build Huffman Tree */
3024    ZSTD_memset(nextHuf->CTable, 0, sizeof(nextHuf->CTable));
3025    huffLog = HUF_optimalTableLog(huffLog, srcSize, maxSymbolValue);
3026    {   size_t const maxBits = HUF_buildCTable_wksp((HUF_CElt*)nextHuf->CTable, countWksp,
3027                                                    maxSymbolValue, huffLog,
3028                                                    nodeWksp, nodeWkspSize);
3029        FORWARD_IF_ERROR(maxBits, "HUF_buildCTable_wksp");
3030        huffLog = (U32)maxBits;
3031        {   /* Build and write the CTable */
3032            size_t const newCSize = HUF_estimateCompressedSize(
3033                    (HUF_CElt*)nextHuf->CTable, countWksp, maxSymbolValue);
3034            size_t const hSize = HUF_writeCTable_wksp(
3035                    hufMetadata->hufDesBuffer, sizeof(hufMetadata->hufDesBuffer),
3036                    (HUF_CElt*)nextHuf->CTable, maxSymbolValue, huffLog,
3037                    nodeWksp, nodeWkspSize);
3038            /* Check against repeating the previous CTable */
3039            if (repeat != HUF_repeat_none) {
3040                size_t const oldCSize = HUF_estimateCompressedSize(
3041                        (HUF_CElt const*)prevHuf->CTable, countWksp, maxSymbolValue);
3042                if (oldCSize < srcSize && (oldCSize <= hSize + newCSize || hSize + 12 >= srcSize)) {
3043                    DEBUGLOG(5, "set_repeat - smaller");
3044                    ZSTD_memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
3045                    hufMetadata->hType = set_repeat;
3046                    return 0;
3047                }
3048            }
3049            if (newCSize + hSize >= srcSize) {
3050                DEBUGLOG(5, "set_basic - no gains");
3051                ZSTD_memcpy(nextHuf, prevHuf, sizeof(*prevHuf));
3052                hufMetadata->hType = set_basic;
3053                return 0;
3054            }
3055            DEBUGLOG(5, "set_compressed (hSize=%u)", (U32)hSize);
3056            hufMetadata->hType = set_compressed;
3057            nextHuf->repeatMode = HUF_repeat_check;
3058            return hSize;
3059        }
3060    }
3061}
3062
3063
3064/* ZSTD_buildDummySequencesStatistics():
3065 * Returns a ZSTD_symbolEncodingTypeStats_t with all encoding types as set_basic,
3066 * and updates nextEntropy to the appropriate repeatMode.
3067 */
3068static ZSTD_symbolEncodingTypeStats_t
3069ZSTD_buildDummySequencesStatistics(ZSTD_fseCTables_t* nextEntropy) {
3070    ZSTD_symbolEncodingTypeStats_t stats = {set_basic, set_basic, set_basic, 0, 0};
3071    nextEntropy->litlength_repeatMode = FSE_repeat_none;
3072    nextEntropy->offcode_repeatMode = FSE_repeat_none;
3073    nextEntropy->matchlength_repeatMode = FSE_repeat_none;
3074    return stats;
3075}
3076
3077/* ZSTD_buildBlockEntropyStats_sequences() :
3078 *  Builds entropy for the sequences.
3079 *  Stores symbol compression modes and fse table to fseMetadata.
3080 *  Requires ENTROPY_WORKSPACE_SIZE wksp.
3081 *  @return : size of fse tables or error code */
3082static size_t ZSTD_buildBlockEntropyStats_sequences(seqStore_t* seqStorePtr,
3083                                              const ZSTD_fseCTables_t* prevEntropy,
3084                                                    ZSTD_fseCTables_t* nextEntropy,
3085                                              const ZSTD_CCtx_params* cctxParams,
3086                                                    ZSTD_fseCTablesMetadata_t* fseMetadata,
3087                                                    void* workspace, size_t wkspSize)
3088{
3089    ZSTD_strategy const strategy = cctxParams->cParams.strategy;
3090    size_t const nbSeq = seqStorePtr->sequences - seqStorePtr->sequencesStart;
3091    BYTE* const ostart = fseMetadata->fseTablesBuffer;
3092    BYTE* const oend = ostart + sizeof(fseMetadata->fseTablesBuffer);
3093    BYTE* op = ostart;
3094    unsigned* countWorkspace = (unsigned*)workspace;
3095    unsigned* entropyWorkspace = countWorkspace + (MaxSeq + 1);
3096    size_t entropyWorkspaceSize = wkspSize - (MaxSeq + 1) * sizeof(*countWorkspace);
3097    ZSTD_symbolEncodingTypeStats_t stats;
3098
3099    DEBUGLOG(5, "ZSTD_buildBlockEntropyStats_sequences (nbSeq=%zu)", nbSeq);
3100    stats = nbSeq != 0 ? ZSTD_buildSequencesStatistics(seqStorePtr, nbSeq,
3101                                          prevEntropy, nextEntropy, op, oend,
3102                                          strategy, countWorkspace,
3103                                          entropyWorkspace, entropyWorkspaceSize)
3104                       : ZSTD_buildDummySequencesStatistics(nextEntropy);
3105    FORWARD_IF_ERROR(stats.size, "ZSTD_buildSequencesStatistics failed!");
3106    fseMetadata->llType = (symbolEncodingType_e) stats.LLtype;
3107    fseMetadata->ofType = (symbolEncodingType_e) stats.Offtype;
3108    fseMetadata->mlType = (symbolEncodingType_e) stats.MLtype;
3109    fseMetadata->lastCountSize = stats.lastCountSize;
3110    return stats.size;
3111}
3112
3113
3114/* ZSTD_buildBlockEntropyStats() :
3115 *  Builds entropy for the block.
3116 *  Requires workspace size ENTROPY_WORKSPACE_SIZE
3117 *
3118 *  @return : 0 on success or error code
3119 */
3120size_t ZSTD_buildBlockEntropyStats(seqStore_t* seqStorePtr,
3121                             const ZSTD_entropyCTables_t* prevEntropy,
3122                                   ZSTD_entropyCTables_t* nextEntropy,
3123                             const ZSTD_CCtx_params* cctxParams,
3124                                   ZSTD_entropyCTablesMetadata_t* entropyMetadata,
3125                                   void* workspace, size_t wkspSize)
3126{
3127    size_t const litSize = seqStorePtr->lit - seqStorePtr->litStart;
3128    entropyMetadata->hufMetadata.hufDesSize =
3129        ZSTD_buildBlockEntropyStats_literals(seqStorePtr->litStart, litSize,
3130                                            &prevEntropy->huf, &nextEntropy->huf,
3131                                            &entropyMetadata->hufMetadata,
3132                                            ZSTD_literalsCompressionIsDisabled(cctxParams),
3133                                            workspace, wkspSize);
3134    FORWARD_IF_ERROR(entropyMetadata->hufMetadata.hufDesSize, "ZSTD_buildBlockEntropyStats_literals failed");
3135    entropyMetadata->fseMetadata.fseTablesSize =
3136        ZSTD_buildBlockEntropyStats_sequences(seqStorePtr,
3137                                              &prevEntropy->fse, &nextEntropy->fse,
3138                                              cctxParams,
3139                                              &entropyMetadata->fseMetadata,
3140                                              workspace, wkspSize);
3141    FORWARD_IF_ERROR(entropyMetadata->fseMetadata.fseTablesSize, "ZSTD_buildBlockEntropyStats_sequences failed");
3142    return 0;
3143}
3144
3145/* Returns the size estimate for the literals section (header + content) of a block */
3146static size_t ZSTD_estimateBlockSize_literal(const BYTE* literals, size_t litSize,
3147                                                const ZSTD_hufCTables_t* huf,
3148                                                const ZSTD_hufCTablesMetadata_t* hufMetadata,
3149                                                void* workspace, size_t wkspSize,
3150                                                int writeEntropy)
3151{
3152    unsigned* const countWksp = (unsigned*)workspace;
3153    unsigned maxSymbolValue = HUF_SYMBOLVALUE_MAX;
3154    size_t literalSectionHeaderSize = 3 + (litSize >= 1 KB) + (litSize >= 16 KB);
3155    U32 singleStream = litSize < 256;
3156
3157    if (hufMetadata->hType == set_basic) return litSize;
3158    else if (hufMetadata->hType == set_rle) return 1;
3159    else if (hufMetadata->hType == set_compressed || hufMetadata->hType == set_repeat) {
3160        size_t const largest = HIST_count_wksp (countWksp, &maxSymbolValue, (const BYTE*)literals, litSize, workspace, wkspSize);
3161        if (ZSTD_isError(largest)) return litSize;
3162        {   size_t cLitSizeEstimate = HUF_estimateCompressedSize((const HUF_CElt*)huf->CTable, countWksp, maxSymbolValue);
3163            if (writeEntropy) cLitSizeEstimate += hufMetadata->hufDesSize;
3164            if (!singleStream) cLitSizeEstimate += 6; /* multi-stream huffman uses 6-byte jump table */
3165            return cLitSizeEstimate + literalSectionHeaderSize;
3166    }   }
3167    assert(0); /* impossible */
3168    return 0;
3169}
3170
3171/* Returns the size estimate for the FSE-compressed symbols (of, ml, ll) of a block */
3172static size_t ZSTD_estimateBlockSize_symbolType(symbolEncodingType_e type,
3173                        const BYTE* codeTable, size_t nbSeq, unsigned maxCode,
3174                        const FSE_CTable* fseCTable,
3175                        const U8* additionalBits,
3176                        short const* defaultNorm, U32 defaultNormLog, U32 defaultMax,
3177                        void* workspace, size_t wkspSize)
3178{
3179    unsigned* const countWksp = (unsigned*)workspace;
3180    const BYTE* ctp = codeTable;
3181    const BYTE* const ctStart = ctp;
3182    const BYTE* const ctEnd = ctStart + nbSeq;
3183    size_t cSymbolTypeSizeEstimateInBits = 0;
3184    unsigned max = maxCode;
3185
3186    HIST_countFast_wksp(countWksp, &max, codeTable, nbSeq, workspace, wkspSize);  /* can't fail */
3187    if (type == set_basic) {
3188        /* We selected this encoding type, so it must be valid. */
3189        assert(max <= defaultMax);
3190        (void)defaultMax;
3191        cSymbolTypeSizeEstimateInBits = ZSTD_crossEntropyCost(defaultNorm, defaultNormLog, countWksp, max);
3192    } else if (type == set_rle) {
3193        cSymbolTypeSizeEstimateInBits = 0;
3194    } else if (type == set_compressed || type == set_repeat) {
3195        cSymbolTypeSizeEstimateInBits = ZSTD_fseBitCost(fseCTable, countWksp, max);
3196    }
3197    if (ZSTD_isError(cSymbolTypeSizeEstimateInBits)) {
3198        return nbSeq * 10;
3199    }
3200    while (ctp < ctEnd) {
3201        if (additionalBits) cSymbolTypeSizeEstimateInBits += additionalBits[*ctp];
3202        else cSymbolTypeSizeEstimateInBits += *ctp; /* for offset, offset code is also the number of additional bits */
3203        ctp++;
3204    }
3205    return cSymbolTypeSizeEstimateInBits >> 3;
3206}
3207
3208/* Returns the size estimate for the sequences section (header + content) of a block */
3209static size_t ZSTD_estimateBlockSize_sequences(const BYTE* ofCodeTable,
3210                                                  const BYTE* llCodeTable,
3211                                                  const BYTE* mlCodeTable,
3212                                                  size_t nbSeq,
3213                                                  const ZSTD_fseCTables_t* fseTables,
3214                                                  const ZSTD_fseCTablesMetadata_t* fseMetadata,
3215                                                  void* workspace, size_t wkspSize,
3216                                                  int writeEntropy)
3217{
3218    size_t sequencesSectionHeaderSize = 1 /* seqHead */ + 1 /* min seqSize size */ + (nbSeq >= 128) + (nbSeq >= LONGNBSEQ);
3219    size_t cSeqSizeEstimate = 0;
3220    cSeqSizeEstimate += ZSTD_estimateBlockSize_symbolType(fseMetadata->ofType, ofCodeTable, nbSeq, MaxOff,
3221                                         fseTables->offcodeCTable, NULL,
3222                                         OF_defaultNorm, OF_defaultNormLog, DefaultMaxOff,
3223                                         workspace, wkspSize);
3224    cSeqSizeEstimate += ZSTD_estimateBlockSize_symbolType(fseMetadata->llType, llCodeTable, nbSeq, MaxLL,
3225                                         fseTables->litlengthCTable, LL_bits,
3226                                         LL_defaultNorm, LL_defaultNormLog, MaxLL,
3227                                         workspace, wkspSize);
3228    cSeqSizeEstimate += ZSTD_estimateBlockSize_symbolType(fseMetadata->mlType, mlCodeTable, nbSeq, MaxML,
3229                                         fseTables->matchlengthCTable, ML_bits,
3230                                         ML_defaultNorm, ML_defaultNormLog, MaxML,
3231                                         workspace, wkspSize);
3232    if (writeEntropy) cSeqSizeEstimate += fseMetadata->fseTablesSize;
3233    return cSeqSizeEstimate + sequencesSectionHeaderSize;
3234}
3235
3236/* Returns the size estimate for a given stream of literals, of, ll, ml */
3237static size_t ZSTD_estimateBlockSize(const BYTE* literals, size_t litSize,
3238                                     const BYTE* ofCodeTable,
3239                                     const BYTE* llCodeTable,
3240                                     const BYTE* mlCodeTable,
3241                                     size_t nbSeq,
3242                                     const ZSTD_entropyCTables_t* entropy,
3243                                     const ZSTD_entropyCTablesMetadata_t* entropyMetadata,
3244                                     void* workspace, size_t wkspSize,
3245                                     int writeLitEntropy, int writeSeqEntropy) {
3246    size_t const literalsSize = ZSTD_estimateBlockSize_literal(literals, litSize,
3247                                                         &entropy->huf, &entropyMetadata->hufMetadata,
3248                                                         workspace, wkspSize, writeLitEntropy);
3249    size_t const seqSize = ZSTD_estimateBlockSize_sequences(ofCodeTable, llCodeTable, mlCodeTable,
3250                                                         nbSeq, &entropy->fse, &entropyMetadata->fseMetadata,
3251                                                         workspace, wkspSize, writeSeqEntropy);
3252    return seqSize + literalsSize + ZSTD_blockHeaderSize;
3253}
3254
3255/* Builds entropy statistics and uses them for blocksize estimation.
3256 *
3257 * Returns the estimated compressed size of the seqStore, or a zstd error.
3258 */
3259static size_t ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(seqStore_t* seqStore, ZSTD_CCtx* zc) {
3260    ZSTD_entropyCTablesMetadata_t* entropyMetadata = &zc->blockSplitCtx.entropyMetadata;
3261    DEBUGLOG(6, "ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize()");
3262    FORWARD_IF_ERROR(ZSTD_buildBlockEntropyStats(seqStore,
3263                    &zc->blockState.prevCBlock->entropy,
3264                    &zc->blockState.nextCBlock->entropy,
3265                    &zc->appliedParams,
3266                    entropyMetadata,
3267                    zc->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */), "");
3268    return ZSTD_estimateBlockSize(seqStore->litStart, (size_t)(seqStore->lit - seqStore->litStart),
3269                    seqStore->ofCode, seqStore->llCode, seqStore->mlCode,
3270                    (size_t)(seqStore->sequences - seqStore->sequencesStart),
3271                    &zc->blockState.nextCBlock->entropy, entropyMetadata, zc->entropyWorkspace, ENTROPY_WORKSPACE_SIZE,
3272                    (int)(entropyMetadata->hufMetadata.hType == set_compressed), 1);
3273}
3274
3275/* Returns literals bytes represented in a seqStore */
3276static size_t ZSTD_countSeqStoreLiteralsBytes(const seqStore_t* const seqStore) {
3277    size_t literalsBytes = 0;
3278    size_t const nbSeqs = seqStore->sequences - seqStore->sequencesStart;
3279    size_t i;
3280    for (i = 0; i < nbSeqs; ++i) {
3281        seqDef seq = seqStore->sequencesStart[i];
3282        literalsBytes += seq.litLength;
3283        if (i == seqStore->longLengthPos && seqStore->longLengthType == ZSTD_llt_literalLength) {
3284            literalsBytes += 0x10000;
3285        }
3286    }
3287    return literalsBytes;
3288}
3289
3290/* Returns match bytes represented in a seqStore */
3291static size_t ZSTD_countSeqStoreMatchBytes(const seqStore_t* const seqStore) {
3292    size_t matchBytes = 0;
3293    size_t const nbSeqs = seqStore->sequences - seqStore->sequencesStart;
3294    size_t i;
3295    for (i = 0; i < nbSeqs; ++i) {
3296        seqDef seq = seqStore->sequencesStart[i];
3297        matchBytes += seq.mlBase + MINMATCH;
3298        if (i == seqStore->longLengthPos && seqStore->longLengthType == ZSTD_llt_matchLength) {
3299            matchBytes += 0x10000;
3300        }
3301    }
3302    return matchBytes;
3303}
3304
3305/* Derives the seqStore that is a chunk of the originalSeqStore from [startIdx, endIdx).
3306 * Stores the result in resultSeqStore.
3307 */
3308static void ZSTD_deriveSeqStoreChunk(seqStore_t* resultSeqStore,
3309                               const seqStore_t* originalSeqStore,
3310                                     size_t startIdx, size_t endIdx) {
3311    BYTE* const litEnd = originalSeqStore->lit;
3312    size_t literalsBytes;
3313    size_t literalsBytesPreceding = 0;
3314
3315    *resultSeqStore = *originalSeqStore;
3316    if (startIdx > 0) {
3317        resultSeqStore->sequences = originalSeqStore->sequencesStart + startIdx;
3318        literalsBytesPreceding = ZSTD_countSeqStoreLiteralsBytes(resultSeqStore);
3319    }
3320
3321    /* Move longLengthPos into the correct position if necessary */
3322    if (originalSeqStore->longLengthType != ZSTD_llt_none) {
3323        if (originalSeqStore->longLengthPos < startIdx || originalSeqStore->longLengthPos > endIdx) {
3324            resultSeqStore->longLengthType = ZSTD_llt_none;
3325        } else {
3326            resultSeqStore->longLengthPos -= (U32)startIdx;
3327        }
3328    }
3329    resultSeqStore->sequencesStart = originalSeqStore->sequencesStart + startIdx;
3330    resultSeqStore->sequences = originalSeqStore->sequencesStart + endIdx;
3331    literalsBytes = ZSTD_countSeqStoreLiteralsBytes(resultSeqStore);
3332    resultSeqStore->litStart += literalsBytesPreceding;
3333    if (endIdx == (size_t)(originalSeqStore->sequences - originalSeqStore->sequencesStart)) {
3334        /* This accounts for possible last literals if the derived chunk reaches the end of the block */
3335        resultSeqStore->lit = litEnd;
3336    } else {
3337        resultSeqStore->lit = resultSeqStore->litStart+literalsBytes;
3338    }
3339    resultSeqStore->llCode += startIdx;
3340    resultSeqStore->mlCode += startIdx;
3341    resultSeqStore->ofCode += startIdx;
3342}
3343
3344/*
3345 * Returns the raw offset represented by the combination of offCode, ll0, and repcode history.
3346 * offCode must represent a repcode in the numeric representation of ZSTD_storeSeq().
3347 */
3348static U32
3349ZSTD_resolveRepcodeToRawOffset(const U32 rep[ZSTD_REP_NUM], const U32 offCode, const U32 ll0)
3350{
3351    U32 const adjustedOffCode = STORED_REPCODE(offCode) - 1 + ll0;  /* [ 0 - 3 ] */
3352    assert(STORED_IS_REPCODE(offCode));
3353    if (adjustedOffCode == ZSTD_REP_NUM) {
3354        /* litlength == 0 and offCode == 2 implies selection of first repcode - 1 */
3355        assert(rep[0] > 0);
3356        return rep[0] - 1;
3357    }
3358    return rep[adjustedOffCode];
3359}
3360
3361/*
3362 * ZSTD_seqStore_resolveOffCodes() reconciles any possible divergences in offset history that may arise
3363 * due to emission of RLE/raw blocks that disturb the offset history,
3364 * and replaces any repcodes within the seqStore that may be invalid.
3365 *
3366 * dRepcodes are updated as would be on the decompression side.
3367 * cRepcodes are updated exactly in accordance with the seqStore.
3368 *
3369 * Note : this function assumes seq->offBase respects the following numbering scheme :
3370 *        0 : invalid
3371 *        1-3 : repcode 1-3
3372 *        4+ : real_offset+3
3373 */
3374static void ZSTD_seqStore_resolveOffCodes(repcodes_t* const dRepcodes, repcodes_t* const cRepcodes,
3375                                          seqStore_t* const seqStore, U32 const nbSeq) {
3376    U32 idx = 0;
3377    for (; idx < nbSeq; ++idx) {
3378        seqDef* const seq = seqStore->sequencesStart + idx;
3379        U32 const ll0 = (seq->litLength == 0);
3380        U32 const offCode = OFFBASE_TO_STORED(seq->offBase);
3381        assert(seq->offBase > 0);
3382        if (STORED_IS_REPCODE(offCode)) {
3383            U32 const dRawOffset = ZSTD_resolveRepcodeToRawOffset(dRepcodes->rep, offCode, ll0);
3384            U32 const cRawOffset = ZSTD_resolveRepcodeToRawOffset(cRepcodes->rep, offCode, ll0);
3385            /* Adjust simulated decompression repcode history if we come across a mismatch. Replace
3386             * the repcode with the offset it actually references, determined by the compression
3387             * repcode history.
3388             */
3389            if (dRawOffset != cRawOffset) {
3390                seq->offBase = cRawOffset + ZSTD_REP_NUM;
3391            }
3392        }
3393        /* Compression repcode history is always updated with values directly from the unmodified seqStore.
3394         * Decompression repcode history may use modified seq->offset value taken from compression repcode history.
3395         */
3396        ZSTD_updateRep(dRepcodes->rep, OFFBASE_TO_STORED(seq->offBase), ll0);
3397        ZSTD_updateRep(cRepcodes->rep, offCode, ll0);
3398    }
3399}
3400
3401/* ZSTD_compressSeqStore_singleBlock():
3402 * Compresses a seqStore into a block with a block header, into the buffer dst.
3403 *
3404 * Returns the total size of that block (including header) or a ZSTD error code.
3405 */
3406static size_t
3407ZSTD_compressSeqStore_singleBlock(ZSTD_CCtx* zc, seqStore_t* const seqStore,
3408                                  repcodes_t* const dRep, repcodes_t* const cRep,
3409                                  void* dst, size_t dstCapacity,
3410                                  const void* src, size_t srcSize,
3411                                  U32 lastBlock, U32 isPartition)
3412{
3413    const U32 rleMaxLength = 25;
3414    BYTE* op = (BYTE*)dst;
3415    const BYTE* ip = (const BYTE*)src;
3416    size_t cSize;
3417    size_t cSeqsSize;
3418
3419    /* In case of an RLE or raw block, the simulated decompression repcode history must be reset */
3420    repcodes_t const dRepOriginal = *dRep;
3421    DEBUGLOG(5, "ZSTD_compressSeqStore_singleBlock");
3422    if (isPartition)
3423        ZSTD_seqStore_resolveOffCodes(dRep, cRep, seqStore, (U32)(seqStore->sequences - seqStore->sequencesStart));
3424
3425    RETURN_ERROR_IF(dstCapacity < ZSTD_blockHeaderSize, dstSize_tooSmall, "Block header doesn't fit");
3426    cSeqsSize = ZSTD_entropyCompressSeqStore(seqStore,
3427                &zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
3428                &zc->appliedParams,
3429                op + ZSTD_blockHeaderSize, dstCapacity - ZSTD_blockHeaderSize,
3430                srcSize,
3431                zc->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
3432                zc->bmi2);
3433    FORWARD_IF_ERROR(cSeqsSize, "ZSTD_entropyCompressSeqStore failed!");
3434
3435    if (!zc->isFirstBlock &&
3436        cSeqsSize < rleMaxLength &&
3437        ZSTD_isRLE((BYTE const*)src, srcSize)) {
3438        /* We don't want to emit our first block as a RLE even if it qualifies because
3439        * doing so will cause the decoder (cli only) to throw a "should consume all input error."
3440        * This is only an issue for zstd <= v1.4.3
3441        */
3442        cSeqsSize = 1;
3443    }
3444
3445    if (zc->seqCollector.collectSequences) {
3446        ZSTD_copyBlockSequences(zc);
3447        ZSTD_blockState_confirmRepcodesAndEntropyTables(&zc->blockState);
3448        return 0;
3449    }
3450
3451    if (cSeqsSize == 0) {
3452        cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, srcSize, lastBlock);
3453        FORWARD_IF_ERROR(cSize, "Nocompress block failed");
3454        DEBUGLOG(4, "Writing out nocompress block, size: %zu", cSize);
3455        *dRep = dRepOriginal; /* reset simulated decompression repcode history */
3456    } else if (cSeqsSize == 1) {
3457        cSize = ZSTD_rleCompressBlock(op, dstCapacity, *ip, srcSize, lastBlock);
3458        FORWARD_IF_ERROR(cSize, "RLE compress block failed");
3459        DEBUGLOG(4, "Writing out RLE block, size: %zu", cSize);
3460        *dRep = dRepOriginal; /* reset simulated decompression repcode history */
3461    } else {
3462        ZSTD_blockState_confirmRepcodesAndEntropyTables(&zc->blockState);
3463        writeBlockHeader(op, cSeqsSize, srcSize, lastBlock);
3464        cSize = ZSTD_blockHeaderSize + cSeqsSize;
3465        DEBUGLOG(4, "Writing out compressed block, size: %zu", cSize);
3466    }
3467
3468    if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
3469        zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
3470
3471    return cSize;
3472}
3473
3474/* Struct to keep track of where we are in our recursive calls. */
3475typedef struct {
3476    U32* splitLocations;    /* Array of split indices */
3477    size_t idx;             /* The current index within splitLocations being worked on */
3478} seqStoreSplits;
3479
3480#define MIN_SEQUENCES_BLOCK_SPLITTING 300
3481
3482/* Helper function to perform the recursive search for block splits.
3483 * Estimates the cost of seqStore prior to split, and estimates the cost of splitting the sequences in half.
3484 * If advantageous to split, then we recurse down the two sub-blocks. If not, or if an error occurred in estimation, then
3485 * we do not recurse.
3486 *
3487 * Note: The recursion depth is capped by a heuristic minimum number of sequences, defined by MIN_SEQUENCES_BLOCK_SPLITTING.
3488 * In theory, this means the absolute largest recursion depth is 10 == log2(maxNbSeqInBlock/MIN_SEQUENCES_BLOCK_SPLITTING).
3489 * In practice, recursion depth usually doesn't go beyond 4.
3490 *
3491 * Furthermore, the number of splits is capped by ZSTD_MAX_NB_BLOCK_SPLITS. At ZSTD_MAX_NB_BLOCK_SPLITS == 196 with the current existing blockSize
3492 * maximum of 128 KB, this value is actually impossible to reach.
3493 */
3494static void
3495ZSTD_deriveBlockSplitsHelper(seqStoreSplits* splits, size_t startIdx, size_t endIdx,
3496                             ZSTD_CCtx* zc, const seqStore_t* origSeqStore)
3497{
3498    seqStore_t* fullSeqStoreChunk = &zc->blockSplitCtx.fullSeqStoreChunk;
3499    seqStore_t* firstHalfSeqStore = &zc->blockSplitCtx.firstHalfSeqStore;
3500    seqStore_t* secondHalfSeqStore = &zc->blockSplitCtx.secondHalfSeqStore;
3501    size_t estimatedOriginalSize;
3502    size_t estimatedFirstHalfSize;
3503    size_t estimatedSecondHalfSize;
3504    size_t midIdx = (startIdx + endIdx)/2;
3505
3506    if (endIdx - startIdx < MIN_SEQUENCES_BLOCK_SPLITTING || splits->idx >= ZSTD_MAX_NB_BLOCK_SPLITS) {
3507        DEBUGLOG(6, "ZSTD_deriveBlockSplitsHelper: Too few sequences");
3508        return;
3509    }
3510    DEBUGLOG(4, "ZSTD_deriveBlockSplitsHelper: startIdx=%zu endIdx=%zu", startIdx, endIdx);
3511    ZSTD_deriveSeqStoreChunk(fullSeqStoreChunk, origSeqStore, startIdx, endIdx);
3512    ZSTD_deriveSeqStoreChunk(firstHalfSeqStore, origSeqStore, startIdx, midIdx);
3513    ZSTD_deriveSeqStoreChunk(secondHalfSeqStore, origSeqStore, midIdx, endIdx);
3514    estimatedOriginalSize = ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(fullSeqStoreChunk, zc);
3515    estimatedFirstHalfSize = ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(firstHalfSeqStore, zc);
3516    estimatedSecondHalfSize = ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(secondHalfSeqStore, zc);
3517    DEBUGLOG(4, "Estimated original block size: %zu -- First half split: %zu -- Second half split: %zu",
3518             estimatedOriginalSize, estimatedFirstHalfSize, estimatedSecondHalfSize);
3519    if (ZSTD_isError(estimatedOriginalSize) || ZSTD_isError(estimatedFirstHalfSize) || ZSTD_isError(estimatedSecondHalfSize)) {
3520        return;
3521    }
3522    if (estimatedFirstHalfSize + estimatedSecondHalfSize < estimatedOriginalSize) {
3523        ZSTD_deriveBlockSplitsHelper(splits, startIdx, midIdx, zc, origSeqStore);
3524        splits->splitLocations[splits->idx] = (U32)midIdx;
3525        splits->idx++;
3526        ZSTD_deriveBlockSplitsHelper(splits, midIdx, endIdx, zc, origSeqStore);
3527    }
3528}
3529
3530/* Base recursive function. Populates a table with intra-block partition indices that can improve compression ratio.
3531 *
3532 * Returns the number of splits made (which equals the size of the partition table - 1).
3533 */
3534static size_t ZSTD_deriveBlockSplits(ZSTD_CCtx* zc, U32 partitions[], U32 nbSeq) {
3535    seqStoreSplits splits = {partitions, 0};
3536    if (nbSeq <= 4) {
3537        DEBUGLOG(4, "ZSTD_deriveBlockSplits: Too few sequences to split");
3538        /* Refuse to try and split anything with less than 4 sequences */
3539        return 0;
3540    }
3541    ZSTD_deriveBlockSplitsHelper(&splits, 0, nbSeq, zc, &zc->seqStore);
3542    splits.splitLocations[splits.idx] = nbSeq;
3543    DEBUGLOG(5, "ZSTD_deriveBlockSplits: final nb partitions: %zu", splits.idx+1);
3544    return splits.idx;
3545}
3546
3547/* ZSTD_compressBlock_splitBlock():
3548 * Attempts to split a given block into multiple blocks to improve compression ratio.
3549 *
3550 * Returns combined size of all blocks (which includes headers), or a ZSTD error code.
3551 */
3552static size_t
3553ZSTD_compressBlock_splitBlock_internal(ZSTD_CCtx* zc, void* dst, size_t dstCapacity,
3554                                       const void* src, size_t blockSize, U32 lastBlock, U32 nbSeq)
3555{
3556    size_t cSize = 0;
3557    const BYTE* ip = (const BYTE*)src;
3558    BYTE* op = (BYTE*)dst;
3559    size_t i = 0;
3560    size_t srcBytesTotal = 0;
3561    U32* partitions = zc->blockSplitCtx.partitions; /* size == ZSTD_MAX_NB_BLOCK_SPLITS */
3562    seqStore_t* nextSeqStore = &zc->blockSplitCtx.nextSeqStore;
3563    seqStore_t* currSeqStore = &zc->blockSplitCtx.currSeqStore;
3564    size_t numSplits = ZSTD_deriveBlockSplits(zc, partitions, nbSeq);
3565
3566    /* If a block is split and some partitions are emitted as RLE/uncompressed, then repcode history
3567     * may become invalid. In order to reconcile potentially invalid repcodes, we keep track of two
3568     * separate repcode histories that simulate repcode history on compression and decompression side,
3569     * and use the histories to determine whether we must replace a particular repcode with its raw offset.
3570     *
3571     * 1) cRep gets updated for each partition, regardless of whether the block was emitted as uncompressed
3572     *    or RLE. This allows us to retrieve the offset value that an invalid repcode references within
3573     *    a nocompress/RLE block.
3574     * 2) dRep gets updated only for compressed partitions, and when a repcode gets replaced, will use
3575     *    the replacement offset value rather than the original repcode to update the repcode history.
3576     *    dRep also will be the final repcode history sent to the next block.
3577     *
3578     * See ZSTD_seqStore_resolveOffCodes() for more details.
3579     */
3580    repcodes_t dRep;
3581    repcodes_t cRep;
3582    ZSTD_memcpy(dRep.rep, zc->blockState.prevCBlock->rep, sizeof(repcodes_t));
3583    ZSTD_memcpy(cRep.rep, zc->blockState.prevCBlock->rep, sizeof(repcodes_t));
3584    ZSTD_memset(nextSeqStore, 0, sizeof(seqStore_t));
3585
3586    DEBUGLOG(4, "ZSTD_compressBlock_splitBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
3587                (unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit,
3588                (unsigned)zc->blockState.matchState.nextToUpdate);
3589
3590    if (numSplits == 0) {
3591        size_t cSizeSingleBlock = ZSTD_compressSeqStore_singleBlock(zc, &zc->seqStore,
3592                                                                   &dRep, &cRep,
3593                                                                    op, dstCapacity,
3594                                                                    ip, blockSize,
3595                                                                    lastBlock, 0 /* isPartition */);
3596        FORWARD_IF_ERROR(cSizeSingleBlock, "Compressing single block from splitBlock_internal() failed!");
3597        DEBUGLOG(5, "ZSTD_compressBlock_splitBlock_internal: No splits");
3598        assert(cSizeSingleBlock <= ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize);
3599        return cSizeSingleBlock;
3600    }
3601
3602    ZSTD_deriveSeqStoreChunk(currSeqStore, &zc->seqStore, 0, partitions[0]);
3603    for (i = 0; i <= numSplits; ++i) {
3604        size_t srcBytes;
3605        size_t cSizeChunk;
3606        U32 const lastPartition = (i == numSplits);
3607        U32 lastBlockEntireSrc = 0;
3608
3609        srcBytes = ZSTD_countSeqStoreLiteralsBytes(currSeqStore) + ZSTD_countSeqStoreMatchBytes(currSeqStore);
3610        srcBytesTotal += srcBytes;
3611        if (lastPartition) {
3612            /* This is the final partition, need to account for possible last literals */
3613            srcBytes += blockSize - srcBytesTotal;
3614            lastBlockEntireSrc = lastBlock;
3615        } else {
3616            ZSTD_deriveSeqStoreChunk(nextSeqStore, &zc->seqStore, partitions[i], partitions[i+1]);
3617        }
3618
3619        cSizeChunk = ZSTD_compressSeqStore_singleBlock(zc, currSeqStore,
3620                                                      &dRep, &cRep,
3621                                                       op, dstCapacity,
3622                                                       ip, srcBytes,
3623                                                       lastBlockEntireSrc, 1 /* isPartition */);
3624        DEBUGLOG(5, "Estimated size: %zu actual size: %zu", ZSTD_buildEntropyStatisticsAndEstimateSubBlockSize(currSeqStore, zc), cSizeChunk);
3625        FORWARD_IF_ERROR(cSizeChunk, "Compressing chunk failed!");
3626
3627        ip += srcBytes;
3628        op += cSizeChunk;
3629        dstCapacity -= cSizeChunk;
3630        cSize += cSizeChunk;
3631        *currSeqStore = *nextSeqStore;
3632        assert(cSizeChunk <= ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize);
3633    }
3634    /* cRep and dRep may have diverged during the compression. If so, we use the dRep repcodes
3635     * for the next block.
3636     */
3637    ZSTD_memcpy(zc->blockState.prevCBlock->rep, dRep.rep, sizeof(repcodes_t));
3638    return cSize;
3639}
3640
3641static size_t
3642ZSTD_compressBlock_splitBlock(ZSTD_CCtx* zc,
3643                              void* dst, size_t dstCapacity,
3644                              const void* src, size_t srcSize, U32 lastBlock)
3645{
3646    const BYTE* ip = (const BYTE*)src;
3647    BYTE* op = (BYTE*)dst;
3648    U32 nbSeq;
3649    size_t cSize;
3650    DEBUGLOG(4, "ZSTD_compressBlock_splitBlock");
3651    assert(zc->appliedParams.useBlockSplitter == ZSTD_ps_enable);
3652
3653    {   const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
3654        FORWARD_IF_ERROR(bss, "ZSTD_buildSeqStore failed");
3655        if (bss == ZSTDbss_noCompress) {
3656            if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
3657                zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
3658            cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, srcSize, lastBlock);
3659            FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed");
3660            DEBUGLOG(4, "ZSTD_compressBlock_splitBlock: Nocompress block");
3661            return cSize;
3662        }
3663        nbSeq = (U32)(zc->seqStore.sequences - zc->seqStore.sequencesStart);
3664    }
3665
3666    cSize = ZSTD_compressBlock_splitBlock_internal(zc, dst, dstCapacity, src, srcSize, lastBlock, nbSeq);
3667    FORWARD_IF_ERROR(cSize, "Splitting blocks failed!");
3668    return cSize;
3669}
3670
3671static size_t
3672ZSTD_compressBlock_internal(ZSTD_CCtx* zc,
3673                            void* dst, size_t dstCapacity,
3674                            const void* src, size_t srcSize, U32 frame)
3675{
3676    /* This the upper bound for the length of an rle block.
3677     * This isn't the actual upper bound. Finding the real threshold
3678     * needs further investigation.
3679     */
3680    const U32 rleMaxLength = 25;
3681    size_t cSize;
3682    const BYTE* ip = (const BYTE*)src;
3683    BYTE* op = (BYTE*)dst;
3684    DEBUGLOG(5, "ZSTD_compressBlock_internal (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u)",
3685                (unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit,
3686                (unsigned)zc->blockState.matchState.nextToUpdate);
3687
3688    {   const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
3689        FORWARD_IF_ERROR(bss, "ZSTD_buildSeqStore failed");
3690        if (bss == ZSTDbss_noCompress) { cSize = 0; goto out; }
3691    }
3692
3693    if (zc->seqCollector.collectSequences) {
3694        ZSTD_copyBlockSequences(zc);
3695        ZSTD_blockState_confirmRepcodesAndEntropyTables(&zc->blockState);
3696        return 0;
3697    }
3698
3699    /* encode sequences and literals */
3700    cSize = ZSTD_entropyCompressSeqStore(&zc->seqStore,
3701            &zc->blockState.prevCBlock->entropy, &zc->blockState.nextCBlock->entropy,
3702            &zc->appliedParams,
3703            dst, dstCapacity,
3704            srcSize,
3705            zc->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
3706            zc->bmi2);
3707
3708    if (frame &&
3709        /* We don't want to emit our first block as a RLE even if it qualifies because
3710         * doing so will cause the decoder (cli only) to throw a "should consume all input error."
3711         * This is only an issue for zstd <= v1.4.3
3712         */
3713        !zc->isFirstBlock &&
3714        cSize < rleMaxLength &&
3715        ZSTD_isRLE(ip, srcSize))
3716    {
3717        cSize = 1;
3718        op[0] = ip[0];
3719    }
3720
3721out:
3722    if (!ZSTD_isError(cSize) && cSize > 1) {
3723        ZSTD_blockState_confirmRepcodesAndEntropyTables(&zc->blockState);
3724    }
3725    /* We check that dictionaries have offset codes available for the first
3726     * block. After the first block, the offcode table might not have large
3727     * enough codes to represent the offsets in the data.
3728     */
3729    if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
3730        zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
3731
3732    return cSize;
3733}
3734
3735static size_t ZSTD_compressBlock_targetCBlockSize_body(ZSTD_CCtx* zc,
3736                               void* dst, size_t dstCapacity,
3737                               const void* src, size_t srcSize,
3738                               const size_t bss, U32 lastBlock)
3739{
3740    DEBUGLOG(6, "Attempting ZSTD_compressSuperBlock()");
3741    if (bss == ZSTDbss_compress) {
3742        if (/* We don't want to emit our first block as a RLE even if it qualifies because
3743            * doing so will cause the decoder (cli only) to throw a "should consume all input error."
3744            * This is only an issue for zstd <= v1.4.3
3745            */
3746            !zc->isFirstBlock &&
3747            ZSTD_maybeRLE(&zc->seqStore) &&
3748            ZSTD_isRLE((BYTE const*)src, srcSize))
3749        {
3750            return ZSTD_rleCompressBlock(dst, dstCapacity, *(BYTE const*)src, srcSize, lastBlock);
3751        }
3752        /* Attempt superblock compression.
3753         *
3754         * Note that compressed size of ZSTD_compressSuperBlock() is not bound by the
3755         * standard ZSTD_compressBound(). This is a problem, because even if we have
3756         * space now, taking an extra byte now could cause us to run out of space later
3757         * and violate ZSTD_compressBound().
3758         *
3759         * Define blockBound(blockSize) = blockSize + ZSTD_blockHeaderSize.
3760         *
3761         * In order to respect ZSTD_compressBound() we must attempt to emit a raw
3762         * uncompressed block in these cases:
3763         *   * cSize == 0: Return code for an uncompressed block.
3764         *   * cSize == dstSize_tooSmall: We may have expanded beyond blockBound(srcSize).
3765         *     ZSTD_noCompressBlock() will return dstSize_tooSmall if we are really out of
3766         *     output space.
3767         *   * cSize >= blockBound(srcSize): We have expanded the block too much so
3768         *     emit an uncompressed block.
3769         */
3770        {
3771            size_t const cSize = ZSTD_compressSuperBlock(zc, dst, dstCapacity, src, srcSize, lastBlock);
3772            if (cSize != ERROR(dstSize_tooSmall)) {
3773                size_t const maxCSize = srcSize - ZSTD_minGain(srcSize, zc->appliedParams.cParams.strategy);
3774                FORWARD_IF_ERROR(cSize, "ZSTD_compressSuperBlock failed");
3775                if (cSize != 0 && cSize < maxCSize + ZSTD_blockHeaderSize) {
3776                    ZSTD_blockState_confirmRepcodesAndEntropyTables(&zc->blockState);
3777                    return cSize;
3778                }
3779            }
3780        }
3781    }
3782
3783    DEBUGLOG(6, "Resorting to ZSTD_noCompressBlock()");
3784    /* Superblock compression failed, attempt to emit a single no compress block.
3785     * The decoder will be able to stream this block since it is uncompressed.
3786     */
3787    return ZSTD_noCompressBlock(dst, dstCapacity, src, srcSize, lastBlock);
3788}
3789
3790static size_t ZSTD_compressBlock_targetCBlockSize(ZSTD_CCtx* zc,
3791                               void* dst, size_t dstCapacity,
3792                               const void* src, size_t srcSize,
3793                               U32 lastBlock)
3794{
3795    size_t cSize = 0;
3796    const size_t bss = ZSTD_buildSeqStore(zc, src, srcSize);
3797    DEBUGLOG(5, "ZSTD_compressBlock_targetCBlockSize (dstCapacity=%u, dictLimit=%u, nextToUpdate=%u, srcSize=%zu)",
3798                (unsigned)dstCapacity, (unsigned)zc->blockState.matchState.window.dictLimit, (unsigned)zc->blockState.matchState.nextToUpdate, srcSize);
3799    FORWARD_IF_ERROR(bss, "ZSTD_buildSeqStore failed");
3800
3801    cSize = ZSTD_compressBlock_targetCBlockSize_body(zc, dst, dstCapacity, src, srcSize, bss, lastBlock);
3802    FORWARD_IF_ERROR(cSize, "ZSTD_compressBlock_targetCBlockSize_body failed");
3803
3804    if (zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
3805        zc->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
3806
3807    return cSize;
3808}
3809
3810static void ZSTD_overflowCorrectIfNeeded(ZSTD_matchState_t* ms,
3811                                         ZSTD_cwksp* ws,
3812                                         ZSTD_CCtx_params const* params,
3813                                         void const* ip,
3814                                         void const* iend)
3815{
3816    U32 const cycleLog = ZSTD_cycleLog(params->cParams.chainLog, params->cParams.strategy);
3817    U32 const maxDist = (U32)1 << params->cParams.windowLog;
3818    if (ZSTD_window_needOverflowCorrection(ms->window, cycleLog, maxDist, ms->loadedDictEnd, ip, iend)) {
3819        U32 const correction = ZSTD_window_correctOverflow(&ms->window, cycleLog, maxDist, ip);
3820        ZSTD_STATIC_ASSERT(ZSTD_CHAINLOG_MAX <= 30);
3821        ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX_32 <= 30);
3822        ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31);
3823        ZSTD_cwksp_mark_tables_dirty(ws);
3824        ZSTD_reduceIndex(ms, params, correction);
3825        ZSTD_cwksp_mark_tables_clean(ws);
3826        if (ms->nextToUpdate < correction) ms->nextToUpdate = 0;
3827        else ms->nextToUpdate -= correction;
3828        /* invalidate dictionaries on overflow correction */
3829        ms->loadedDictEnd = 0;
3830        ms->dictMatchState = NULL;
3831    }
3832}
3833
3834/*! ZSTD_compress_frameChunk() :
3835*   Compress a chunk of data into one or multiple blocks.
3836*   All blocks will be terminated, all input will be consumed.
3837*   Function will issue an error if there is not enough `dstCapacity` to hold the compressed content.
3838*   Frame is supposed already started (header already produced)
3839*   @return : compressed size, or an error code
3840*/
3841static size_t ZSTD_compress_frameChunk(ZSTD_CCtx* cctx,
3842                                     void* dst, size_t dstCapacity,
3843                               const void* src, size_t srcSize,
3844                                     U32 lastFrameChunk)
3845{
3846    size_t blockSize = cctx->blockSize;
3847    size_t remaining = srcSize;
3848    const BYTE* ip = (const BYTE*)src;
3849    BYTE* const ostart = (BYTE*)dst;
3850    BYTE* op = ostart;
3851    U32 const maxDist = (U32)1 << cctx->appliedParams.cParams.windowLog;
3852
3853    assert(cctx->appliedParams.cParams.windowLog <= ZSTD_WINDOWLOG_MAX);
3854
3855    DEBUGLOG(4, "ZSTD_compress_frameChunk (blockSize=%u)", (unsigned)blockSize);
3856    if (cctx->appliedParams.fParams.checksumFlag && srcSize)
3857        xxh64_update(&cctx->xxhState, src, srcSize);
3858
3859    while (remaining) {
3860        ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
3861        U32 const lastBlock = lastFrameChunk & (blockSize >= remaining);
3862
3863        RETURN_ERROR_IF(dstCapacity < ZSTD_blockHeaderSize + MIN_CBLOCK_SIZE,
3864                        dstSize_tooSmall,
3865                        "not enough space to store compressed block");
3866        if (remaining < blockSize) blockSize = remaining;
3867
3868        ZSTD_overflowCorrectIfNeeded(
3869            ms, &cctx->workspace, &cctx->appliedParams, ip, ip + blockSize);
3870        ZSTD_checkDictValidity(&ms->window, ip + blockSize, maxDist, &ms->loadedDictEnd, &ms->dictMatchState);
3871        ZSTD_window_enforceMaxDist(&ms->window, ip, maxDist, &ms->loadedDictEnd, &ms->dictMatchState);
3872
3873        /* Ensure hash/chain table insertion resumes no sooner than lowlimit */
3874        if (ms->nextToUpdate < ms->window.lowLimit) ms->nextToUpdate = ms->window.lowLimit;
3875
3876        {   size_t cSize;
3877            if (ZSTD_useTargetCBlockSize(&cctx->appliedParams)) {
3878                cSize = ZSTD_compressBlock_targetCBlockSize(cctx, op, dstCapacity, ip, blockSize, lastBlock);
3879                FORWARD_IF_ERROR(cSize, "ZSTD_compressBlock_targetCBlockSize failed");
3880                assert(cSize > 0);
3881                assert(cSize <= blockSize + ZSTD_blockHeaderSize);
3882            } else if (ZSTD_blockSplitterEnabled(&cctx->appliedParams)) {
3883                cSize = ZSTD_compressBlock_splitBlock(cctx, op, dstCapacity, ip, blockSize, lastBlock);
3884                FORWARD_IF_ERROR(cSize, "ZSTD_compressBlock_splitBlock failed");
3885                assert(cSize > 0 || cctx->seqCollector.collectSequences == 1);
3886            } else {
3887                cSize = ZSTD_compressBlock_internal(cctx,
3888                                        op+ZSTD_blockHeaderSize, dstCapacity-ZSTD_blockHeaderSize,
3889                                        ip, blockSize, 1 /* frame */);
3890                FORWARD_IF_ERROR(cSize, "ZSTD_compressBlock_internal failed");
3891
3892                if (cSize == 0) {  /* block is not compressible */
3893                    cSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
3894                    FORWARD_IF_ERROR(cSize, "ZSTD_noCompressBlock failed");
3895                } else {
3896                    U32 const cBlockHeader = cSize == 1 ?
3897                        lastBlock + (((U32)bt_rle)<<1) + (U32)(blockSize << 3) :
3898                        lastBlock + (((U32)bt_compressed)<<1) + (U32)(cSize << 3);
3899                    MEM_writeLE24(op, cBlockHeader);
3900                    cSize += ZSTD_blockHeaderSize;
3901                }
3902            }
3903
3904
3905            ip += blockSize;
3906            assert(remaining >= blockSize);
3907            remaining -= blockSize;
3908            op += cSize;
3909            assert(dstCapacity >= cSize);
3910            dstCapacity -= cSize;
3911            cctx->isFirstBlock = 0;
3912            DEBUGLOG(5, "ZSTD_compress_frameChunk: adding a block of size %u",
3913                        (unsigned)cSize);
3914    }   }
3915
3916    if (lastFrameChunk && (op>ostart)) cctx->stage = ZSTDcs_ending;
3917    return (size_t)(op-ostart);
3918}
3919
3920
3921static size_t ZSTD_writeFrameHeader(void* dst, size_t dstCapacity,
3922                                    const ZSTD_CCtx_params* params, U64 pledgedSrcSize, U32 dictID)
3923{   BYTE* const op = (BYTE*)dst;
3924    U32   const dictIDSizeCodeLength = (dictID>0) + (dictID>=256) + (dictID>=65536);   /* 0-3 */
3925    U32   const dictIDSizeCode = params->fParams.noDictIDFlag ? 0 : dictIDSizeCodeLength;   /* 0-3 */
3926    U32   const checksumFlag = params->fParams.checksumFlag>0;
3927    U32   const windowSize = (U32)1 << params->cParams.windowLog;
3928    U32   const singleSegment = params->fParams.contentSizeFlag && (windowSize >= pledgedSrcSize);
3929    BYTE  const windowLogByte = (BYTE)((params->cParams.windowLog - ZSTD_WINDOWLOG_ABSOLUTEMIN) << 3);
3930    U32   const fcsCode = params->fParams.contentSizeFlag ?
3931                     (pledgedSrcSize>=256) + (pledgedSrcSize>=65536+256) + (pledgedSrcSize>=0xFFFFFFFFU) : 0;  /* 0-3 */
3932    BYTE  const frameHeaderDescriptionByte = (BYTE)(dictIDSizeCode + (checksumFlag<<2) + (singleSegment<<5) + (fcsCode<<6) );
3933    size_t pos=0;
3934
3935    assert(!(params->fParams.contentSizeFlag && pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN));
3936    RETURN_ERROR_IF(dstCapacity < ZSTD_FRAMEHEADERSIZE_MAX, dstSize_tooSmall,
3937                    "dst buf is too small to fit worst-case frame header size.");
3938    DEBUGLOG(4, "ZSTD_writeFrameHeader : dictIDFlag : %u ; dictID : %u ; dictIDSizeCode : %u",
3939                !params->fParams.noDictIDFlag, (unsigned)dictID, (unsigned)dictIDSizeCode);
3940    if (params->format == ZSTD_f_zstd1) {
3941        MEM_writeLE32(dst, ZSTD_MAGICNUMBER);
3942        pos = 4;
3943    }
3944    op[pos++] = frameHeaderDescriptionByte;
3945    if (!singleSegment) op[pos++] = windowLogByte;
3946    switch(dictIDSizeCode)
3947    {
3948        default:
3949            assert(0); /* impossible */
3950            ZSTD_FALLTHROUGH;
3951        case 0 : break;
3952        case 1 : op[pos] = (BYTE)(dictID); pos++; break;
3953        case 2 : MEM_writeLE16(op+pos, (U16)dictID); pos+=2; break;
3954        case 3 : MEM_writeLE32(op+pos, dictID); pos+=4; break;
3955    }
3956    switch(fcsCode)
3957    {
3958        default:
3959            assert(0); /* impossible */
3960            ZSTD_FALLTHROUGH;
3961        case 0 : if (singleSegment) op[pos++] = (BYTE)(pledgedSrcSize); break;
3962        case 1 : MEM_writeLE16(op+pos, (U16)(pledgedSrcSize-256)); pos+=2; break;
3963        case 2 : MEM_writeLE32(op+pos, (U32)(pledgedSrcSize)); pos+=4; break;
3964        case 3 : MEM_writeLE64(op+pos, (U64)(pledgedSrcSize)); pos+=8; break;
3965    }
3966    return pos;
3967}
3968
3969/* ZSTD_writeSkippableFrame_advanced() :
3970 * Writes out a skippable frame with the specified magic number variant (16 are supported),
3971 * from ZSTD_MAGIC_SKIPPABLE_START to ZSTD_MAGIC_SKIPPABLE_START+15, and the desired source data.
3972 *
3973 * Returns the total number of bytes written, or a ZSTD error code.
3974 */
3975size_t ZSTD_writeSkippableFrame(void* dst, size_t dstCapacity,
3976                                const void* src, size_t srcSize, unsigned magicVariant) {
3977    BYTE* op = (BYTE*)dst;
3978    RETURN_ERROR_IF(dstCapacity < srcSize + ZSTD_SKIPPABLEHEADERSIZE /* Skippable frame overhead */,
3979                    dstSize_tooSmall, "Not enough room for skippable frame");
3980    RETURN_ERROR_IF(srcSize > (unsigned)0xFFFFFFFF, srcSize_wrong, "Src size too large for skippable frame");
3981    RETURN_ERROR_IF(magicVariant > 15, parameter_outOfBound, "Skippable frame magic number variant not supported");
3982
3983    MEM_writeLE32(op, (U32)(ZSTD_MAGIC_SKIPPABLE_START + magicVariant));
3984    MEM_writeLE32(op+4, (U32)srcSize);
3985    ZSTD_memcpy(op+8, src, srcSize);
3986    return srcSize + ZSTD_SKIPPABLEHEADERSIZE;
3987}
3988
3989/* ZSTD_writeLastEmptyBlock() :
3990 * output an empty Block with end-of-frame mark to complete a frame
3991 * @return : size of data written into `dst` (== ZSTD_blockHeaderSize (defined in zstd_internal.h))
3992 *           or an error code if `dstCapacity` is too small (<ZSTD_blockHeaderSize)
3993 */
3994size_t ZSTD_writeLastEmptyBlock(void* dst, size_t dstCapacity)
3995{
3996    RETURN_ERROR_IF(dstCapacity < ZSTD_blockHeaderSize, dstSize_tooSmall,
3997                    "dst buf is too small to write frame trailer empty block.");
3998    {   U32 const cBlockHeader24 = 1 /*lastBlock*/ + (((U32)bt_raw)<<1);  /* 0 size */
3999        MEM_writeLE24(dst, cBlockHeader24);
4000        return ZSTD_blockHeaderSize;
4001    }
4002}
4003
4004size_t ZSTD_referenceExternalSequences(ZSTD_CCtx* cctx, rawSeq* seq, size_t nbSeq)
4005{
4006    RETURN_ERROR_IF(cctx->stage != ZSTDcs_init, stage_wrong,
4007                    "wrong cctx stage");
4008    RETURN_ERROR_IF(cctx->appliedParams.ldmParams.enableLdm == ZSTD_ps_enable,
4009                    parameter_unsupported,
4010                    "incompatible with ldm");
4011    cctx->externSeqStore.seq = seq;
4012    cctx->externSeqStore.size = nbSeq;
4013    cctx->externSeqStore.capacity = nbSeq;
4014    cctx->externSeqStore.pos = 0;
4015    cctx->externSeqStore.posInSequence = 0;
4016    return 0;
4017}
4018
4019
4020static size_t ZSTD_compressContinue_internal (ZSTD_CCtx* cctx,
4021                              void* dst, size_t dstCapacity,
4022                        const void* src, size_t srcSize,
4023                               U32 frame, U32 lastFrameChunk)
4024{
4025    ZSTD_matchState_t* const ms = &cctx->blockState.matchState;
4026    size_t fhSize = 0;
4027
4028    DEBUGLOG(5, "ZSTD_compressContinue_internal, stage: %u, srcSize: %u",
4029                cctx->stage, (unsigned)srcSize);
4030    RETURN_ERROR_IF(cctx->stage==ZSTDcs_created, stage_wrong,
4031                    "missing init (ZSTD_compressBegin)");
4032
4033    if (frame && (cctx->stage==ZSTDcs_init)) {
4034        fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, &cctx->appliedParams,
4035                                       cctx->pledgedSrcSizePlusOne-1, cctx->dictID);
4036        FORWARD_IF_ERROR(fhSize, "ZSTD_writeFrameHeader failed");
4037        assert(fhSize <= dstCapacity);
4038        dstCapacity -= fhSize;
4039        dst = (char*)dst + fhSize;
4040        cctx->stage = ZSTDcs_ongoing;
4041    }
4042
4043    if (!srcSize) return fhSize;  /* do not generate an empty block if no input */
4044
4045    if (!ZSTD_window_update(&ms->window, src, srcSize, ms->forceNonContiguous)) {
4046        ms->forceNonContiguous = 0;
4047        ms->nextToUpdate = ms->window.dictLimit;
4048    }
4049    if (cctx->appliedParams.ldmParams.enableLdm == ZSTD_ps_enable) {
4050        ZSTD_window_update(&cctx->ldmState.window, src, srcSize, /* forceNonContiguous */ 0);
4051    }
4052
4053    if (!frame) {
4054        /* overflow check and correction for block mode */
4055        ZSTD_overflowCorrectIfNeeded(
4056            ms, &cctx->workspace, &cctx->appliedParams,
4057            src, (BYTE const*)src + srcSize);
4058    }
4059
4060    DEBUGLOG(5, "ZSTD_compressContinue_internal (blockSize=%u)", (unsigned)cctx->blockSize);
4061    {   size_t const cSize = frame ?
4062                             ZSTD_compress_frameChunk (cctx, dst, dstCapacity, src, srcSize, lastFrameChunk) :
4063                             ZSTD_compressBlock_internal (cctx, dst, dstCapacity, src, srcSize, 0 /* frame */);
4064        FORWARD_IF_ERROR(cSize, "%s", frame ? "ZSTD_compress_frameChunk failed" : "ZSTD_compressBlock_internal failed");
4065        cctx->consumedSrcSize += srcSize;
4066        cctx->producedCSize += (cSize + fhSize);
4067        assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
4068        if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
4069            ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
4070            RETURN_ERROR_IF(
4071                cctx->consumedSrcSize+1 > cctx->pledgedSrcSizePlusOne,
4072                srcSize_wrong,
4073                "error : pledgedSrcSize = %u, while realSrcSize >= %u",
4074                (unsigned)cctx->pledgedSrcSizePlusOne-1,
4075                (unsigned)cctx->consumedSrcSize);
4076        }
4077        return cSize + fhSize;
4078    }
4079}
4080
4081size_t ZSTD_compressContinue (ZSTD_CCtx* cctx,
4082                              void* dst, size_t dstCapacity,
4083                        const void* src, size_t srcSize)
4084{
4085    DEBUGLOG(5, "ZSTD_compressContinue (srcSize=%u)", (unsigned)srcSize);
4086    return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 1 /* frame mode */, 0 /* last chunk */);
4087}
4088
4089
4090size_t ZSTD_getBlockSize(const ZSTD_CCtx* cctx)
4091{
4092    ZSTD_compressionParameters const cParams = cctx->appliedParams.cParams;
4093    assert(!ZSTD_checkCParams(cParams));
4094    return MIN (ZSTD_BLOCKSIZE_MAX, (U32)1 << cParams.windowLog);
4095}
4096
4097size_t ZSTD_compressBlock(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
4098{
4099    DEBUGLOG(5, "ZSTD_compressBlock: srcSize = %u", (unsigned)srcSize);
4100    { size_t const blockSizeMax = ZSTD_getBlockSize(cctx);
4101      RETURN_ERROR_IF(srcSize > blockSizeMax, srcSize_wrong, "input is larger than a block"); }
4102
4103    return ZSTD_compressContinue_internal(cctx, dst, dstCapacity, src, srcSize, 0 /* frame mode */, 0 /* last chunk */);
4104}
4105
4106/*! ZSTD_loadDictionaryContent() :
4107 *  @return : 0, or an error code
4108 */
4109static size_t ZSTD_loadDictionaryContent(ZSTD_matchState_t* ms,
4110                                         ldmState_t* ls,
4111                                         ZSTD_cwksp* ws,
4112                                         ZSTD_CCtx_params const* params,
4113                                         const void* src, size_t srcSize,
4114                                         ZSTD_dictTableLoadMethod_e dtlm)
4115{
4116    const BYTE* ip = (const BYTE*) src;
4117    const BYTE* const iend = ip + srcSize;
4118    int const loadLdmDict = params->ldmParams.enableLdm == ZSTD_ps_enable && ls != NULL;
4119
4120    /* Assert that we the ms params match the params we're being given */
4121    ZSTD_assertEqualCParams(params->cParams, ms->cParams);
4122
4123    if (srcSize > ZSTD_CHUNKSIZE_MAX) {
4124        /* Allow the dictionary to set indices up to exactly ZSTD_CURRENT_MAX.
4125         * Dictionaries right at the edge will immediately trigger overflow
4126         * correction, but I don't want to insert extra constraints here.
4127         */
4128        U32 const maxDictSize = ZSTD_CURRENT_MAX - 1;
4129        /* We must have cleared our windows when our source is this large. */
4130        assert(ZSTD_window_isEmpty(ms->window));
4131        if (loadLdmDict)
4132            assert(ZSTD_window_isEmpty(ls->window));
4133        /* If the dictionary is too large, only load the suffix of the dictionary. */
4134        if (srcSize > maxDictSize) {
4135            ip = iend - maxDictSize;
4136            src = ip;
4137            srcSize = maxDictSize;
4138        }
4139    }
4140
4141    DEBUGLOG(4, "ZSTD_loadDictionaryContent(): useRowMatchFinder=%d", (int)params->useRowMatchFinder);
4142    ZSTD_window_update(&ms->window, src, srcSize, /* forceNonContiguous */ 0);
4143    ms->loadedDictEnd = params->forceWindow ? 0 : (U32)(iend - ms->window.base);
4144    ms->forceNonContiguous = params->deterministicRefPrefix;
4145
4146    if (loadLdmDict) {
4147        ZSTD_window_update(&ls->window, src, srcSize, /* forceNonContiguous */ 0);
4148        ls->loadedDictEnd = params->forceWindow ? 0 : (U32)(iend - ls->window.base);
4149    }
4150
4151    if (srcSize <= HASH_READ_SIZE) return 0;
4152
4153    ZSTD_overflowCorrectIfNeeded(ms, ws, params, ip, iend);
4154
4155    if (loadLdmDict)
4156        ZSTD_ldm_fillHashTable(ls, ip, iend, &params->ldmParams);
4157
4158    switch(params->cParams.strategy)
4159    {
4160    case ZSTD_fast:
4161        ZSTD_fillHashTable(ms, iend, dtlm);
4162        break;
4163    case ZSTD_dfast:
4164        ZSTD_fillDoubleHashTable(ms, iend, dtlm);
4165        break;
4166
4167    case ZSTD_greedy:
4168    case ZSTD_lazy:
4169    case ZSTD_lazy2:
4170        assert(srcSize >= HASH_READ_SIZE);
4171        if (ms->dedicatedDictSearch) {
4172            assert(ms->chainTable != NULL);
4173            ZSTD_dedicatedDictSearch_lazy_loadDictionary(ms, iend-HASH_READ_SIZE);
4174        } else {
4175            assert(params->useRowMatchFinder != ZSTD_ps_auto);
4176            if (params->useRowMatchFinder == ZSTD_ps_enable) {
4177                size_t const tagTableSize = ((size_t)1 << params->cParams.hashLog) * sizeof(U16);
4178                ZSTD_memset(ms->tagTable, 0, tagTableSize);
4179                ZSTD_row_update(ms, iend-HASH_READ_SIZE);
4180                DEBUGLOG(4, "Using row-based hash table for lazy dict");
4181            } else {
4182                ZSTD_insertAndFindFirstIndex(ms, iend-HASH_READ_SIZE);
4183                DEBUGLOG(4, "Using chain-based hash table for lazy dict");
4184            }
4185        }
4186        break;
4187
4188    case ZSTD_btlazy2:   /* we want the dictionary table fully sorted */
4189    case ZSTD_btopt:
4190    case ZSTD_btultra:
4191    case ZSTD_btultra2:
4192        assert(srcSize >= HASH_READ_SIZE);
4193        ZSTD_updateTree(ms, iend-HASH_READ_SIZE, iend);
4194        break;
4195
4196    default:
4197        assert(0);  /* not possible : not a valid strategy id */
4198    }
4199
4200    ms->nextToUpdate = (U32)(iend - ms->window.base);
4201    return 0;
4202}
4203
4204
4205/* Dictionaries that assign zero probability to symbols that show up causes problems
4206 * when FSE encoding. Mark dictionaries with zero probability symbols as FSE_repeat_check
4207 * and only dictionaries with 100% valid symbols can be assumed valid.
4208 */
4209static FSE_repeat ZSTD_dictNCountRepeat(short* normalizedCounter, unsigned dictMaxSymbolValue, unsigned maxSymbolValue)
4210{
4211    U32 s;
4212    if (dictMaxSymbolValue < maxSymbolValue) {
4213        return FSE_repeat_check;
4214    }
4215    for (s = 0; s <= maxSymbolValue; ++s) {
4216        if (normalizedCounter[s] == 0) {
4217            return FSE_repeat_check;
4218        }
4219    }
4220    return FSE_repeat_valid;
4221}
4222
4223size_t ZSTD_loadCEntropy(ZSTD_compressedBlockState_t* bs, void* workspace,
4224                         const void* const dict, size_t dictSize)
4225{
4226    short offcodeNCount[MaxOff+1];
4227    unsigned offcodeMaxValue = MaxOff;
4228    const BYTE* dictPtr = (const BYTE*)dict;    /* skip magic num and dict ID */
4229    const BYTE* const dictEnd = dictPtr + dictSize;
4230    dictPtr += 8;
4231    bs->entropy.huf.repeatMode = HUF_repeat_check;
4232
4233    {   unsigned maxSymbolValue = 255;
4234        unsigned hasZeroWeights = 1;
4235        size_t const hufHeaderSize = HUF_readCTable((HUF_CElt*)bs->entropy.huf.CTable, &maxSymbolValue, dictPtr,
4236            dictEnd-dictPtr, &hasZeroWeights);
4237
4238        /* We only set the loaded table as valid if it contains all non-zero
4239         * weights. Otherwise, we set it to check */
4240        if (!hasZeroWeights)
4241            bs->entropy.huf.repeatMode = HUF_repeat_valid;
4242
4243        RETURN_ERROR_IF(HUF_isError(hufHeaderSize), dictionary_corrupted, "");
4244        RETURN_ERROR_IF(maxSymbolValue < 255, dictionary_corrupted, "");
4245        dictPtr += hufHeaderSize;
4246    }
4247
4248    {   unsigned offcodeLog;
4249        size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, dictEnd-dictPtr);
4250        RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted, "");
4251        RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted, "");
4252        /* fill all offset symbols to avoid garbage at end of table */
4253        RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
4254                bs->entropy.fse.offcodeCTable,
4255                offcodeNCount, MaxOff, offcodeLog,
4256                workspace, HUF_WORKSPACE_SIZE)),
4257            dictionary_corrupted, "");
4258        /* Defer checking offcodeMaxValue because we need to know the size of the dictionary content */
4259        dictPtr += offcodeHeaderSize;
4260    }
4261
4262    {   short matchlengthNCount[MaxML+1];
4263        unsigned matchlengthMaxValue = MaxML, matchlengthLog;
4264        size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, dictEnd-dictPtr);
4265        RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted, "");
4266        RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted, "");
4267        RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
4268                bs->entropy.fse.matchlengthCTable,
4269                matchlengthNCount, matchlengthMaxValue, matchlengthLog,
4270                workspace, HUF_WORKSPACE_SIZE)),
4271            dictionary_corrupted, "");
4272        bs->entropy.fse.matchlength_repeatMode = ZSTD_dictNCountRepeat(matchlengthNCount, matchlengthMaxValue, MaxML);
4273        dictPtr += matchlengthHeaderSize;
4274    }
4275
4276    {   short litlengthNCount[MaxLL+1];
4277        unsigned litlengthMaxValue = MaxLL, litlengthLog;
4278        size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, dictEnd-dictPtr);
4279        RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted, "");
4280        RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted, "");
4281        RETURN_ERROR_IF(FSE_isError(FSE_buildCTable_wksp(
4282                bs->entropy.fse.litlengthCTable,
4283                litlengthNCount, litlengthMaxValue, litlengthLog,
4284                workspace, HUF_WORKSPACE_SIZE)),
4285            dictionary_corrupted, "");
4286        bs->entropy.fse.litlength_repeatMode = ZSTD_dictNCountRepeat(litlengthNCount, litlengthMaxValue, MaxLL);
4287        dictPtr += litlengthHeaderSize;
4288    }
4289
4290    RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted, "");
4291    bs->rep[0] = MEM_readLE32(dictPtr+0);
4292    bs->rep[1] = MEM_readLE32(dictPtr+4);
4293    bs->rep[2] = MEM_readLE32(dictPtr+8);
4294    dictPtr += 12;
4295
4296    {   size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
4297        U32 offcodeMax = MaxOff;
4298        if (dictContentSize <= ((U32)-1) - 128 KB) {
4299            U32 const maxOffset = (U32)dictContentSize + 128 KB; /* The maximum offset that must be supported */
4300            offcodeMax = ZSTD_highbit32(maxOffset); /* Calculate minimum offset code required to represent maxOffset */
4301        }
4302        /* All offset values <= dictContentSize + 128 KB must be representable for a valid table */
4303        bs->entropy.fse.offcode_repeatMode = ZSTD_dictNCountRepeat(offcodeNCount, offcodeMaxValue, MIN(offcodeMax, MaxOff));
4304
4305        /* All repCodes must be <= dictContentSize and != 0 */
4306        {   U32 u;
4307            for (u=0; u<3; u++) {
4308                RETURN_ERROR_IF(bs->rep[u] == 0, dictionary_corrupted, "");
4309                RETURN_ERROR_IF(bs->rep[u] > dictContentSize, dictionary_corrupted, "");
4310    }   }   }
4311
4312    return dictPtr - (const BYTE*)dict;
4313}
4314
4315/* Dictionary format :
4316 * See :
4317 * https://github.com/facebook/zstd/blob/release/doc/zstd_compression_format.md#dictionary-format
4318 */
4319/*! ZSTD_loadZstdDictionary() :
4320 * @return : dictID, or an error code
4321 *  assumptions : magic number supposed already checked
4322 *                dictSize supposed >= 8
4323 */
4324static size_t ZSTD_loadZstdDictionary(ZSTD_compressedBlockState_t* bs,
4325                                      ZSTD_matchState_t* ms,
4326                                      ZSTD_cwksp* ws,
4327                                      ZSTD_CCtx_params const* params,
4328                                      const void* dict, size_t dictSize,
4329                                      ZSTD_dictTableLoadMethod_e dtlm,
4330                                      void* workspace)
4331{
4332    const BYTE* dictPtr = (const BYTE*)dict;
4333    const BYTE* const dictEnd = dictPtr + dictSize;
4334    size_t dictID;
4335    size_t eSize;
4336    ZSTD_STATIC_ASSERT(HUF_WORKSPACE_SIZE >= (1<<MAX(MLFSELog,LLFSELog)));
4337    assert(dictSize >= 8);
4338    assert(MEM_readLE32(dictPtr) == ZSTD_MAGIC_DICTIONARY);
4339
4340    dictID = params->fParams.noDictIDFlag ? 0 :  MEM_readLE32(dictPtr + 4 /* skip magic number */ );
4341    eSize = ZSTD_loadCEntropy(bs, workspace, dict, dictSize);
4342    FORWARD_IF_ERROR(eSize, "ZSTD_loadCEntropy failed");
4343    dictPtr += eSize;
4344
4345    {
4346        size_t const dictContentSize = (size_t)(dictEnd - dictPtr);
4347        FORWARD_IF_ERROR(ZSTD_loadDictionaryContent(
4348            ms, NULL, ws, params, dictPtr, dictContentSize, dtlm), "");
4349    }
4350    return dictID;
4351}
4352
4353/* ZSTD_compress_insertDictionary() :
4354*   @return : dictID, or an error code */
4355static size_t
4356ZSTD_compress_insertDictionary(ZSTD_compressedBlockState_t* bs,
4357                               ZSTD_matchState_t* ms,
4358                               ldmState_t* ls,
4359                               ZSTD_cwksp* ws,
4360                         const ZSTD_CCtx_params* params,
4361                         const void* dict, size_t dictSize,
4362                               ZSTD_dictContentType_e dictContentType,
4363                               ZSTD_dictTableLoadMethod_e dtlm,
4364                               void* workspace)
4365{
4366    DEBUGLOG(4, "ZSTD_compress_insertDictionary (dictSize=%u)", (U32)dictSize);
4367    if ((dict==NULL) || (dictSize<8)) {
4368        RETURN_ERROR_IF(dictContentType == ZSTD_dct_fullDict, dictionary_wrong, "");
4369        return 0;
4370    }
4371
4372    ZSTD_reset_compressedBlockState(bs);
4373
4374    /* dict restricted modes */
4375    if (dictContentType == ZSTD_dct_rawContent)
4376        return ZSTD_loadDictionaryContent(ms, ls, ws, params, dict, dictSize, dtlm);
4377
4378    if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) {
4379        if (dictContentType == ZSTD_dct_auto) {
4380            DEBUGLOG(4, "raw content dictionary detected");
4381            return ZSTD_loadDictionaryContent(
4382                ms, ls, ws, params, dict, dictSize, dtlm);
4383        }
4384        RETURN_ERROR_IF(dictContentType == ZSTD_dct_fullDict, dictionary_wrong, "");
4385        assert(0);   /* impossible */
4386    }
4387
4388    /* dict as full zstd dictionary */
4389    return ZSTD_loadZstdDictionary(
4390        bs, ms, ws, params, dict, dictSize, dtlm, workspace);
4391}
4392
4393#define ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF (128 KB)
4394#define ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER (6ULL)
4395
4396/*! ZSTD_compressBegin_internal() :
4397 * @return : 0, or an error code */
4398static size_t ZSTD_compressBegin_internal(ZSTD_CCtx* cctx,
4399                                    const void* dict, size_t dictSize,
4400                                    ZSTD_dictContentType_e dictContentType,
4401                                    ZSTD_dictTableLoadMethod_e dtlm,
4402                                    const ZSTD_CDict* cdict,
4403                                    const ZSTD_CCtx_params* params, U64 pledgedSrcSize,
4404                                    ZSTD_buffered_policy_e zbuff)
4405{
4406    size_t const dictContentSize = cdict ? cdict->dictContentSize : dictSize;
4407    DEBUGLOG(4, "ZSTD_compressBegin_internal: wlog=%u", params->cParams.windowLog);
4408    /* params are supposed to be fully validated at this point */
4409    assert(!ZSTD_isError(ZSTD_checkCParams(params->cParams)));
4410    assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
4411    if ( (cdict)
4412      && (cdict->dictContentSize > 0)
4413      && ( pledgedSrcSize < ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF
4414        || pledgedSrcSize < cdict->dictContentSize * ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER
4415        || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
4416        || cdict->compressionLevel == 0)
4417      && (params->attachDictPref != ZSTD_dictForceLoad) ) {
4418        return ZSTD_resetCCtx_usingCDict(cctx, cdict, params, pledgedSrcSize, zbuff);
4419    }
4420
4421    FORWARD_IF_ERROR( ZSTD_resetCCtx_internal(cctx, params, pledgedSrcSize,
4422                                     dictContentSize,
4423                                     ZSTDcrp_makeClean, zbuff) , "");
4424    {   size_t const dictID = cdict ?
4425                ZSTD_compress_insertDictionary(
4426                        cctx->blockState.prevCBlock, &cctx->blockState.matchState,
4427                        &cctx->ldmState, &cctx->workspace, &cctx->appliedParams, cdict->dictContent,
4428                        cdict->dictContentSize, cdict->dictContentType, dtlm,
4429                        cctx->entropyWorkspace)
4430              : ZSTD_compress_insertDictionary(
4431                        cctx->blockState.prevCBlock, &cctx->blockState.matchState,
4432                        &cctx->ldmState, &cctx->workspace, &cctx->appliedParams, dict, dictSize,
4433                        dictContentType, dtlm, cctx->entropyWorkspace);
4434        FORWARD_IF_ERROR(dictID, "ZSTD_compress_insertDictionary failed");
4435        assert(dictID <= UINT_MAX);
4436        cctx->dictID = (U32)dictID;
4437        cctx->dictContentSize = dictContentSize;
4438    }
4439    return 0;
4440}
4441
4442size_t ZSTD_compressBegin_advanced_internal(ZSTD_CCtx* cctx,
4443                                    const void* dict, size_t dictSize,
4444                                    ZSTD_dictContentType_e dictContentType,
4445                                    ZSTD_dictTableLoadMethod_e dtlm,
4446                                    const ZSTD_CDict* cdict,
4447                                    const ZSTD_CCtx_params* params,
4448                                    unsigned long long pledgedSrcSize)
4449{
4450    DEBUGLOG(4, "ZSTD_compressBegin_advanced_internal: wlog=%u", params->cParams.windowLog);
4451    /* compression parameters verification and optimization */
4452    FORWARD_IF_ERROR( ZSTD_checkCParams(params->cParams) , "");
4453    return ZSTD_compressBegin_internal(cctx,
4454                                       dict, dictSize, dictContentType, dtlm,
4455                                       cdict,
4456                                       params, pledgedSrcSize,
4457                                       ZSTDb_not_buffered);
4458}
4459
4460/*! ZSTD_compressBegin_advanced() :
4461*   @return : 0, or an error code */
4462size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx,
4463                             const void* dict, size_t dictSize,
4464                                   ZSTD_parameters params, unsigned long long pledgedSrcSize)
4465{
4466    ZSTD_CCtx_params cctxParams;
4467    ZSTD_CCtxParams_init_internal(&cctxParams, &params, ZSTD_NO_CLEVEL);
4468    return ZSTD_compressBegin_advanced_internal(cctx,
4469                                            dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast,
4470                                            NULL /*cdict*/,
4471                                            &cctxParams, pledgedSrcSize);
4472}
4473
4474size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel)
4475{
4476    ZSTD_CCtx_params cctxParams;
4477    {
4478        ZSTD_parameters const params = ZSTD_getParams_internal(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize, ZSTD_cpm_noAttachDict);
4479        ZSTD_CCtxParams_init_internal(&cctxParams, &params, (compressionLevel == 0) ? ZSTD_CLEVEL_DEFAULT : compressionLevel);
4480    }
4481    DEBUGLOG(4, "ZSTD_compressBegin_usingDict (dictSize=%u)", (unsigned)dictSize);
4482    return ZSTD_compressBegin_internal(cctx, dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
4483                                       &cctxParams, ZSTD_CONTENTSIZE_UNKNOWN, ZSTDb_not_buffered);
4484}
4485
4486size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel)
4487{
4488    return ZSTD_compressBegin_usingDict(cctx, NULL, 0, compressionLevel);
4489}
4490
4491
4492/*! ZSTD_writeEpilogue() :
4493*   Ends a frame.
4494*   @return : nb of bytes written into dst (or an error code) */
4495static size_t ZSTD_writeEpilogue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity)
4496{
4497    BYTE* const ostart = (BYTE*)dst;
4498    BYTE* op = ostart;
4499    size_t fhSize = 0;
4500
4501    DEBUGLOG(4, "ZSTD_writeEpilogue");
4502    RETURN_ERROR_IF(cctx->stage == ZSTDcs_created, stage_wrong, "init missing");
4503
4504    /* special case : empty frame */
4505    if (cctx->stage == ZSTDcs_init) {
4506        fhSize = ZSTD_writeFrameHeader(dst, dstCapacity, &cctx->appliedParams, 0, 0);
4507        FORWARD_IF_ERROR(fhSize, "ZSTD_writeFrameHeader failed");
4508        dstCapacity -= fhSize;
4509        op += fhSize;
4510        cctx->stage = ZSTDcs_ongoing;
4511    }
4512
4513    if (cctx->stage != ZSTDcs_ending) {
4514        /* write one last empty block, make it the "last" block */
4515        U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1) + 0;
4516        RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall, "no room for epilogue");
4517        MEM_writeLE32(op, cBlockHeader24);
4518        op += ZSTD_blockHeaderSize;
4519        dstCapacity -= ZSTD_blockHeaderSize;
4520    }
4521
4522    if (cctx->appliedParams.fParams.checksumFlag) {
4523        U32 const checksum = (U32) xxh64_digest(&cctx->xxhState);
4524        RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall, "no room for checksum");
4525        DEBUGLOG(4, "ZSTD_writeEpilogue: write checksum : %08X", (unsigned)checksum);
4526        MEM_writeLE32(op, checksum);
4527        op += 4;
4528    }
4529
4530    cctx->stage = ZSTDcs_created;  /* return to "created but no init" status */
4531    return op-ostart;
4532}
4533
4534void ZSTD_CCtx_trace(ZSTD_CCtx* cctx, size_t extraCSize)
4535{
4536    (void)cctx;
4537    (void)extraCSize;
4538}
4539
4540size_t ZSTD_compressEnd (ZSTD_CCtx* cctx,
4541                         void* dst, size_t dstCapacity,
4542                   const void* src, size_t srcSize)
4543{
4544    size_t endResult;
4545    size_t const cSize = ZSTD_compressContinue_internal(cctx,
4546                                dst, dstCapacity, src, srcSize,
4547                                1 /* frame mode */, 1 /* last chunk */);
4548    FORWARD_IF_ERROR(cSize, "ZSTD_compressContinue_internal failed");
4549    endResult = ZSTD_writeEpilogue(cctx, (char*)dst + cSize, dstCapacity-cSize);
4550    FORWARD_IF_ERROR(endResult, "ZSTD_writeEpilogue failed");
4551    assert(!(cctx->appliedParams.fParams.contentSizeFlag && cctx->pledgedSrcSizePlusOne == 0));
4552    if (cctx->pledgedSrcSizePlusOne != 0) {  /* control src size */
4553        ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_UNKNOWN == (unsigned long long)-1);
4554        DEBUGLOG(4, "end of frame : controlling src size");
4555        RETURN_ERROR_IF(
4556            cctx->pledgedSrcSizePlusOne != cctx->consumedSrcSize+1,
4557            srcSize_wrong,
4558             "error : pledgedSrcSize = %u, while realSrcSize = %u",
4559            (unsigned)cctx->pledgedSrcSizePlusOne-1,
4560            (unsigned)cctx->consumedSrcSize);
4561    }
4562    ZSTD_CCtx_trace(cctx, endResult);
4563    return cSize + endResult;
4564}
4565
4566size_t ZSTD_compress_advanced (ZSTD_CCtx* cctx,
4567                               void* dst, size_t dstCapacity,
4568                         const void* src, size_t srcSize,
4569                         const void* dict,size_t dictSize,
4570                               ZSTD_parameters params)
4571{
4572    DEBUGLOG(4, "ZSTD_compress_advanced");
4573    FORWARD_IF_ERROR(ZSTD_checkCParams(params.cParams), "");
4574    ZSTD_CCtxParams_init_internal(&cctx->simpleApiParams, &params, ZSTD_NO_CLEVEL);
4575    return ZSTD_compress_advanced_internal(cctx,
4576                                           dst, dstCapacity,
4577                                           src, srcSize,
4578                                           dict, dictSize,
4579                                           &cctx->simpleApiParams);
4580}
4581
4582/* Internal */
4583size_t ZSTD_compress_advanced_internal(
4584        ZSTD_CCtx* cctx,
4585        void* dst, size_t dstCapacity,
4586        const void* src, size_t srcSize,
4587        const void* dict,size_t dictSize,
4588        const ZSTD_CCtx_params* params)
4589{
4590    DEBUGLOG(4, "ZSTD_compress_advanced_internal (srcSize:%u)", (unsigned)srcSize);
4591    FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
4592                         dict, dictSize, ZSTD_dct_auto, ZSTD_dtlm_fast, NULL,
4593                         params, srcSize, ZSTDb_not_buffered) , "");
4594    return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
4595}
4596
4597size_t ZSTD_compress_usingDict(ZSTD_CCtx* cctx,
4598                               void* dst, size_t dstCapacity,
4599                         const void* src, size_t srcSize,
4600                         const void* dict, size_t dictSize,
4601                               int compressionLevel)
4602{
4603    {
4604        ZSTD_parameters const params = ZSTD_getParams_internal(compressionLevel, srcSize, dict ? dictSize : 0, ZSTD_cpm_noAttachDict);
4605        assert(params.fParams.contentSizeFlag == 1);
4606        ZSTD_CCtxParams_init_internal(&cctx->simpleApiParams, &params, (compressionLevel == 0) ? ZSTD_CLEVEL_DEFAULT: compressionLevel);
4607    }
4608    DEBUGLOG(4, "ZSTD_compress_usingDict (srcSize=%u)", (unsigned)srcSize);
4609    return ZSTD_compress_advanced_internal(cctx, dst, dstCapacity, src, srcSize, dict, dictSize, &cctx->simpleApiParams);
4610}
4611
4612size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
4613                         void* dst, size_t dstCapacity,
4614                   const void* src, size_t srcSize,
4615                         int compressionLevel)
4616{
4617    DEBUGLOG(4, "ZSTD_compressCCtx (srcSize=%u)", (unsigned)srcSize);
4618    assert(cctx != NULL);
4619    return ZSTD_compress_usingDict(cctx, dst, dstCapacity, src, srcSize, NULL, 0, compressionLevel);
4620}
4621
4622size_t ZSTD_compress(void* dst, size_t dstCapacity,
4623               const void* src, size_t srcSize,
4624                     int compressionLevel)
4625{
4626    size_t result;
4627    ZSTD_CCtx* cctx = ZSTD_createCCtx();
4628    RETURN_ERROR_IF(!cctx, memory_allocation, "ZSTD_createCCtx failed");
4629    result = ZSTD_compressCCtx(cctx, dst, dstCapacity, src, srcSize, compressionLevel);
4630    ZSTD_freeCCtx(cctx);
4631    return result;
4632}
4633
4634
4635/* =====  Dictionary API  ===== */
4636
4637/*! ZSTD_estimateCDictSize_advanced() :
4638 *  Estimate amount of memory that will be needed to create a dictionary with following arguments */
4639size_t ZSTD_estimateCDictSize_advanced(
4640        size_t dictSize, ZSTD_compressionParameters cParams,
4641        ZSTD_dictLoadMethod_e dictLoadMethod)
4642{
4643    DEBUGLOG(5, "sizeof(ZSTD_CDict) : %u", (unsigned)sizeof(ZSTD_CDict));
4644    return ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict))
4645         + ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE)
4646         /* enableDedicatedDictSearch == 1 ensures that CDict estimation will not be too small
4647          * in case we are using DDS with row-hash. */
4648         + ZSTD_sizeof_matchState(&cParams, ZSTD_resolveRowMatchFinderMode(ZSTD_ps_auto, &cParams),
4649                                  /* enableDedicatedDictSearch */ 1, /* forCCtx */ 0)
4650         + (dictLoadMethod == ZSTD_dlm_byRef ? 0
4651            : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void *))));
4652}
4653
4654size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel)
4655{
4656    ZSTD_compressionParameters const cParams = ZSTD_getCParams_internal(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize, ZSTD_cpm_createCDict);
4657    return ZSTD_estimateCDictSize_advanced(dictSize, cParams, ZSTD_dlm_byCopy);
4658}
4659
4660size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict)
4661{
4662    if (cdict==NULL) return 0;   /* support sizeof on NULL */
4663    DEBUGLOG(5, "sizeof(*cdict) : %u", (unsigned)sizeof(*cdict));
4664    /* cdict may be in the workspace */
4665    return (cdict->workspace.workspace == cdict ? 0 : sizeof(*cdict))
4666        + ZSTD_cwksp_sizeof(&cdict->workspace);
4667}
4668
4669static size_t ZSTD_initCDict_internal(
4670                    ZSTD_CDict* cdict,
4671              const void* dictBuffer, size_t dictSize,
4672                    ZSTD_dictLoadMethod_e dictLoadMethod,
4673                    ZSTD_dictContentType_e dictContentType,
4674                    ZSTD_CCtx_params params)
4675{
4676    DEBUGLOG(3, "ZSTD_initCDict_internal (dictContentType:%u)", (unsigned)dictContentType);
4677    assert(!ZSTD_checkCParams(params.cParams));
4678    cdict->matchState.cParams = params.cParams;
4679    cdict->matchState.dedicatedDictSearch = params.enableDedicatedDictSearch;
4680    if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dictBuffer) || (!dictSize)) {
4681        cdict->dictContent = dictBuffer;
4682    } else {
4683         void *internalBuffer = ZSTD_cwksp_reserve_object(&cdict->workspace, ZSTD_cwksp_align(dictSize, sizeof(void*)));
4684        RETURN_ERROR_IF(!internalBuffer, memory_allocation, "NULL pointer!");
4685        cdict->dictContent = internalBuffer;
4686        ZSTD_memcpy(internalBuffer, dictBuffer, dictSize);
4687    }
4688    cdict->dictContentSize = dictSize;
4689    cdict->dictContentType = dictContentType;
4690
4691    cdict->entropyWorkspace = (U32*)ZSTD_cwksp_reserve_object(&cdict->workspace, HUF_WORKSPACE_SIZE);
4692
4693
4694    /* Reset the state to no dictionary */
4695    ZSTD_reset_compressedBlockState(&cdict->cBlockState);
4696    FORWARD_IF_ERROR(ZSTD_reset_matchState(
4697        &cdict->matchState,
4698        &cdict->workspace,
4699        &params.cParams,
4700        params.useRowMatchFinder,
4701        ZSTDcrp_makeClean,
4702        ZSTDirp_reset,
4703        ZSTD_resetTarget_CDict), "");
4704    /* (Maybe) load the dictionary
4705     * Skips loading the dictionary if it is < 8 bytes.
4706     */
4707    {   params.compressionLevel = ZSTD_CLEVEL_DEFAULT;
4708        params.fParams.contentSizeFlag = 1;
4709        {   size_t const dictID = ZSTD_compress_insertDictionary(
4710                    &cdict->cBlockState, &cdict->matchState, NULL, &cdict->workspace,
4711                    &params, cdict->dictContent, cdict->dictContentSize,
4712                    dictContentType, ZSTD_dtlm_full, cdict->entropyWorkspace);
4713            FORWARD_IF_ERROR(dictID, "ZSTD_compress_insertDictionary failed");
4714            assert(dictID <= (size_t)(U32)-1);
4715            cdict->dictID = (U32)dictID;
4716        }
4717    }
4718
4719    return 0;
4720}
4721
4722static ZSTD_CDict* ZSTD_createCDict_advanced_internal(size_t dictSize,
4723                                      ZSTD_dictLoadMethod_e dictLoadMethod,
4724                                      ZSTD_compressionParameters cParams,
4725                                      ZSTD_paramSwitch_e useRowMatchFinder,
4726                                      U32 enableDedicatedDictSearch,
4727                                      ZSTD_customMem customMem)
4728{
4729    if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL;
4730
4731    {   size_t const workspaceSize =
4732            ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict)) +
4733            ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE) +
4734            ZSTD_sizeof_matchState(&cParams, useRowMatchFinder, enableDedicatedDictSearch, /* forCCtx */ 0) +
4735            (dictLoadMethod == ZSTD_dlm_byRef ? 0
4736             : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void*))));
4737        void* const workspace = ZSTD_customMalloc(workspaceSize, customMem);
4738        ZSTD_cwksp ws;
4739        ZSTD_CDict* cdict;
4740
4741        if (!workspace) {
4742            ZSTD_customFree(workspace, customMem);
4743            return NULL;
4744        }
4745
4746        ZSTD_cwksp_init(&ws, workspace, workspaceSize, ZSTD_cwksp_dynamic_alloc);
4747
4748        cdict = (ZSTD_CDict*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CDict));
4749        assert(cdict != NULL);
4750        ZSTD_cwksp_move(&cdict->workspace, &ws);
4751        cdict->customMem = customMem;
4752        cdict->compressionLevel = ZSTD_NO_CLEVEL; /* signals advanced API usage */
4753        cdict->useRowMatchFinder = useRowMatchFinder;
4754        return cdict;
4755    }
4756}
4757
4758ZSTD_CDict* ZSTD_createCDict_advanced(const void* dictBuffer, size_t dictSize,
4759                                      ZSTD_dictLoadMethod_e dictLoadMethod,
4760                                      ZSTD_dictContentType_e dictContentType,
4761                                      ZSTD_compressionParameters cParams,
4762                                      ZSTD_customMem customMem)
4763{
4764    ZSTD_CCtx_params cctxParams;
4765    ZSTD_memset(&cctxParams, 0, sizeof(cctxParams));
4766    ZSTD_CCtxParams_init(&cctxParams, 0);
4767    cctxParams.cParams = cParams;
4768    cctxParams.customMem = customMem;
4769    return ZSTD_createCDict_advanced2(
4770        dictBuffer, dictSize,
4771        dictLoadMethod, dictContentType,
4772        &cctxParams, customMem);
4773}
4774
4775ZSTD_CDict* ZSTD_createCDict_advanced2(
4776        const void* dict, size_t dictSize,
4777        ZSTD_dictLoadMethod_e dictLoadMethod,
4778        ZSTD_dictContentType_e dictContentType,
4779        const ZSTD_CCtx_params* originalCctxParams,
4780        ZSTD_customMem customMem)
4781{
4782    ZSTD_CCtx_params cctxParams = *originalCctxParams;
4783    ZSTD_compressionParameters cParams;
4784    ZSTD_CDict* cdict;
4785
4786    DEBUGLOG(3, "ZSTD_createCDict_advanced2, mode %u", (unsigned)dictContentType);
4787    if (!customMem.customAlloc ^ !customMem.customFree) return NULL;
4788
4789    if (cctxParams.enableDedicatedDictSearch) {
4790        cParams = ZSTD_dedicatedDictSearch_getCParams(
4791            cctxParams.compressionLevel, dictSize);
4792        ZSTD_overrideCParams(&cParams, &cctxParams.cParams);
4793    } else {
4794        cParams = ZSTD_getCParamsFromCCtxParams(
4795            &cctxParams, ZSTD_CONTENTSIZE_UNKNOWN, dictSize, ZSTD_cpm_createCDict);
4796    }
4797
4798    if (!ZSTD_dedicatedDictSearch_isSupported(&cParams)) {
4799        /* Fall back to non-DDSS params */
4800        cctxParams.enableDedicatedDictSearch = 0;
4801        cParams = ZSTD_getCParamsFromCCtxParams(
4802            &cctxParams, ZSTD_CONTENTSIZE_UNKNOWN, dictSize, ZSTD_cpm_createCDict);
4803    }
4804
4805    DEBUGLOG(3, "ZSTD_createCDict_advanced2: DDS: %u", cctxParams.enableDedicatedDictSearch);
4806    cctxParams.cParams = cParams;
4807    cctxParams.useRowMatchFinder = ZSTD_resolveRowMatchFinderMode(cctxParams.useRowMatchFinder, &cParams);
4808
4809    cdict = ZSTD_createCDict_advanced_internal(dictSize,
4810                        dictLoadMethod, cctxParams.cParams,
4811                        cctxParams.useRowMatchFinder, cctxParams.enableDedicatedDictSearch,
4812                        customMem);
4813    if (!cdict)
4814        return NULL;
4815
4816    if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
4817                                    dict, dictSize,
4818                                    dictLoadMethod, dictContentType,
4819                                    cctxParams) )) {
4820        ZSTD_freeCDict(cdict);
4821        return NULL;
4822    }
4823
4824    return cdict;
4825}
4826
4827ZSTD_CDict* ZSTD_createCDict(const void* dict, size_t dictSize, int compressionLevel)
4828{
4829    ZSTD_compressionParameters cParams = ZSTD_getCParams_internal(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize, ZSTD_cpm_createCDict);
4830    ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dict, dictSize,
4831                                                  ZSTD_dlm_byCopy, ZSTD_dct_auto,
4832                                                  cParams, ZSTD_defaultCMem);
4833    if (cdict)
4834        cdict->compressionLevel = (compressionLevel == 0) ? ZSTD_CLEVEL_DEFAULT : compressionLevel;
4835    return cdict;
4836}
4837
4838ZSTD_CDict* ZSTD_createCDict_byReference(const void* dict, size_t dictSize, int compressionLevel)
4839{
4840    ZSTD_compressionParameters cParams = ZSTD_getCParams_internal(compressionLevel, ZSTD_CONTENTSIZE_UNKNOWN, dictSize, ZSTD_cpm_createCDict);
4841    ZSTD_CDict* const cdict = ZSTD_createCDict_advanced(dict, dictSize,
4842                                     ZSTD_dlm_byRef, ZSTD_dct_auto,
4843                                     cParams, ZSTD_defaultCMem);
4844    if (cdict)
4845        cdict->compressionLevel = (compressionLevel == 0) ? ZSTD_CLEVEL_DEFAULT : compressionLevel;
4846    return cdict;
4847}
4848
4849size_t ZSTD_freeCDict(ZSTD_CDict* cdict)
4850{
4851    if (cdict==NULL) return 0;   /* support free on NULL */
4852    {   ZSTD_customMem const cMem = cdict->customMem;
4853        int cdictInWorkspace = ZSTD_cwksp_owns_buffer(&cdict->workspace, cdict);
4854        ZSTD_cwksp_free(&cdict->workspace, cMem);
4855        if (!cdictInWorkspace) {
4856            ZSTD_customFree(cdict, cMem);
4857        }
4858        return 0;
4859    }
4860}
4861
4862/*! ZSTD_initStaticCDict_advanced() :
4863 *  Generate a digested dictionary in provided memory area.
4864 *  workspace: The memory area to emplace the dictionary into.
4865 *             Provided pointer must 8-bytes aligned.
4866 *             It must outlive dictionary usage.
4867 *  workspaceSize: Use ZSTD_estimateCDictSize()
4868 *                 to determine how large workspace must be.
4869 *  cParams : use ZSTD_getCParams() to transform a compression level
4870 *            into its relevants cParams.
4871 * @return : pointer to ZSTD_CDict*, or NULL if error (size too small)
4872 *  Note : there is no corresponding "free" function.
4873 *         Since workspace was allocated externally, it must be freed externally.
4874 */
4875const ZSTD_CDict* ZSTD_initStaticCDict(
4876                                 void* workspace, size_t workspaceSize,
4877                           const void* dict, size_t dictSize,
4878                                 ZSTD_dictLoadMethod_e dictLoadMethod,
4879                                 ZSTD_dictContentType_e dictContentType,
4880                                 ZSTD_compressionParameters cParams)
4881{
4882    ZSTD_paramSwitch_e const useRowMatchFinder = ZSTD_resolveRowMatchFinderMode(ZSTD_ps_auto, &cParams);
4883    /* enableDedicatedDictSearch == 1 ensures matchstate is not too small in case this CDict will be used for DDS + row hash */
4884    size_t const matchStateSize = ZSTD_sizeof_matchState(&cParams, useRowMatchFinder, /* enableDedicatedDictSearch */ 1, /* forCCtx */ 0);
4885    size_t const neededSize = ZSTD_cwksp_alloc_size(sizeof(ZSTD_CDict))
4886                            + (dictLoadMethod == ZSTD_dlm_byRef ? 0
4887                               : ZSTD_cwksp_alloc_size(ZSTD_cwksp_align(dictSize, sizeof(void*))))
4888                            + ZSTD_cwksp_alloc_size(HUF_WORKSPACE_SIZE)
4889                            + matchStateSize;
4890    ZSTD_CDict* cdict;
4891    ZSTD_CCtx_params params;
4892
4893    if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
4894
4895    {
4896        ZSTD_cwksp ws;
4897        ZSTD_cwksp_init(&ws, workspace, workspaceSize, ZSTD_cwksp_static_alloc);
4898        cdict = (ZSTD_CDict*)ZSTD_cwksp_reserve_object(&ws, sizeof(ZSTD_CDict));
4899        if (cdict == NULL) return NULL;
4900        ZSTD_cwksp_move(&cdict->workspace, &ws);
4901    }
4902
4903    DEBUGLOG(4, "(workspaceSize < neededSize) : (%u < %u) => %u",
4904        (unsigned)workspaceSize, (unsigned)neededSize, (unsigned)(workspaceSize < neededSize));
4905    if (workspaceSize < neededSize) return NULL;
4906
4907    ZSTD_CCtxParams_init(&params, 0);
4908    params.cParams = cParams;
4909    params.useRowMatchFinder = useRowMatchFinder;
4910    cdict->useRowMatchFinder = useRowMatchFinder;
4911
4912    if (ZSTD_isError( ZSTD_initCDict_internal(cdict,
4913                                              dict, dictSize,
4914                                              dictLoadMethod, dictContentType,
4915                                              params) ))
4916        return NULL;
4917
4918    return cdict;
4919}
4920
4921ZSTD_compressionParameters ZSTD_getCParamsFromCDict(const ZSTD_CDict* cdict)
4922{
4923    assert(cdict != NULL);
4924    return cdict->matchState.cParams;
4925}
4926
4927/*! ZSTD_getDictID_fromCDict() :
4928 *  Provides the dictID of the dictionary loaded into `cdict`.
4929 *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
4930 *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
4931unsigned ZSTD_getDictID_fromCDict(const ZSTD_CDict* cdict)
4932{
4933    if (cdict==NULL) return 0;
4934    return cdict->dictID;
4935}
4936
4937/* ZSTD_compressBegin_usingCDict_internal() :
4938 * Implementation of various ZSTD_compressBegin_usingCDict* functions.
4939 */
4940static size_t ZSTD_compressBegin_usingCDict_internal(
4941    ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict,
4942    ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize)
4943{
4944    ZSTD_CCtx_params cctxParams;
4945    DEBUGLOG(4, "ZSTD_compressBegin_usingCDict_internal");
4946    RETURN_ERROR_IF(cdict==NULL, dictionary_wrong, "NULL pointer!");
4947    /* Initialize the cctxParams from the cdict */
4948    {
4949        ZSTD_parameters params;
4950        params.fParams = fParams;
4951        params.cParams = ( pledgedSrcSize < ZSTD_USE_CDICT_PARAMS_SRCSIZE_CUTOFF
4952                        || pledgedSrcSize < cdict->dictContentSize * ZSTD_USE_CDICT_PARAMS_DICTSIZE_MULTIPLIER
4953                        || pledgedSrcSize == ZSTD_CONTENTSIZE_UNKNOWN
4954                        || cdict->compressionLevel == 0 ) ?
4955                ZSTD_getCParamsFromCDict(cdict)
4956              : ZSTD_getCParams(cdict->compressionLevel,
4957                                pledgedSrcSize,
4958                                cdict->dictContentSize);
4959        ZSTD_CCtxParams_init_internal(&cctxParams, &params, cdict->compressionLevel);
4960    }
4961    /* Increase window log to fit the entire dictionary and source if the
4962     * source size is known. Limit the increase to 19, which is the
4963     * window log for compression level 1 with the largest source size.
4964     */
4965    if (pledgedSrcSize != ZSTD_CONTENTSIZE_UNKNOWN) {
4966        U32 const limitedSrcSize = (U32)MIN(pledgedSrcSize, 1U << 19);
4967        U32 const limitedSrcLog = limitedSrcSize > 1 ? ZSTD_highbit32(limitedSrcSize - 1) + 1 : 1;
4968        cctxParams.cParams.windowLog = MAX(cctxParams.cParams.windowLog, limitedSrcLog);
4969    }
4970    return ZSTD_compressBegin_internal(cctx,
4971                                        NULL, 0, ZSTD_dct_auto, ZSTD_dtlm_fast,
4972                                        cdict,
4973                                        &cctxParams, pledgedSrcSize,
4974                                        ZSTDb_not_buffered);
4975}
4976
4977
4978/* ZSTD_compressBegin_usingCDict_advanced() :
4979 * This function is DEPRECATED.
4980 * cdict must be != NULL */
4981size_t ZSTD_compressBegin_usingCDict_advanced(
4982    ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict,
4983    ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize)
4984{
4985    return ZSTD_compressBegin_usingCDict_internal(cctx, cdict, fParams, pledgedSrcSize);
4986}
4987
4988/* ZSTD_compressBegin_usingCDict() :
4989 * cdict must be != NULL */
4990size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict)
4991{
4992    ZSTD_frameParameters const fParams = { 0 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
4993    return ZSTD_compressBegin_usingCDict_internal(cctx, cdict, fParams, ZSTD_CONTENTSIZE_UNKNOWN);
4994}
4995
4996/*! ZSTD_compress_usingCDict_internal():
4997 * Implementation of various ZSTD_compress_usingCDict* functions.
4998 */
4999static size_t ZSTD_compress_usingCDict_internal(ZSTD_CCtx* cctx,
5000                                void* dst, size_t dstCapacity,
5001                                const void* src, size_t srcSize,
5002                                const ZSTD_CDict* cdict, ZSTD_frameParameters fParams)
5003{
5004    FORWARD_IF_ERROR(ZSTD_compressBegin_usingCDict_internal(cctx, cdict, fParams, srcSize), ""); /* will check if cdict != NULL */
5005    return ZSTD_compressEnd(cctx, dst, dstCapacity, src, srcSize);
5006}
5007
5008/*! ZSTD_compress_usingCDict_advanced():
5009 * This function is DEPRECATED.
5010 */
5011size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
5012                                void* dst, size_t dstCapacity,
5013                                const void* src, size_t srcSize,
5014                                const ZSTD_CDict* cdict, ZSTD_frameParameters fParams)
5015{
5016    return ZSTD_compress_usingCDict_internal(cctx, dst, dstCapacity, src, srcSize, cdict, fParams);
5017}
5018
5019/*! ZSTD_compress_usingCDict() :
5020 *  Compression using a digested Dictionary.
5021 *  Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
5022 *  Note that compression parameters are decided at CDict creation time
5023 *  while frame parameters are hardcoded */
5024size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
5025                                void* dst, size_t dstCapacity,
5026                                const void* src, size_t srcSize,
5027                                const ZSTD_CDict* cdict)
5028{
5029    ZSTD_frameParameters const fParams = { 1 /*content*/, 0 /*checksum*/, 0 /*noDictID*/ };
5030    return ZSTD_compress_usingCDict_internal(cctx, dst, dstCapacity, src, srcSize, cdict, fParams);
5031}
5032
5033
5034
5035/* ******************************************************************
5036*  Streaming
5037********************************************************************/
5038
5039ZSTD_CStream* ZSTD_createCStream(void)
5040{
5041    DEBUGLOG(3, "ZSTD_createCStream");
5042    return ZSTD_createCStream_advanced(ZSTD_defaultCMem);
5043}
5044
5045ZSTD_CStream* ZSTD_initStaticCStream(void *workspace, size_t workspaceSize)
5046{
5047    return ZSTD_initStaticCCtx(workspace, workspaceSize);
5048}
5049
5050ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem)
5051{   /* CStream and CCtx are now same object */
5052    return ZSTD_createCCtx_advanced(customMem);
5053}
5054
5055size_t ZSTD_freeCStream(ZSTD_CStream* zcs)
5056{
5057    return ZSTD_freeCCtx(zcs);   /* same object */
5058}
5059
5060
5061
5062/*======   Initialization   ======*/
5063
5064size_t ZSTD_CStreamInSize(void)  { return ZSTD_BLOCKSIZE_MAX; }
5065
5066size_t ZSTD_CStreamOutSize(void)
5067{
5068    return ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + 4 /* 32-bits hash */ ;
5069}
5070
5071static ZSTD_cParamMode_e ZSTD_getCParamMode(ZSTD_CDict const* cdict, ZSTD_CCtx_params const* params, U64 pledgedSrcSize)
5072{
5073    if (cdict != NULL && ZSTD_shouldAttachDict(cdict, params, pledgedSrcSize))
5074        return ZSTD_cpm_attachDict;
5075    else
5076        return ZSTD_cpm_noAttachDict;
5077}
5078
5079/* ZSTD_resetCStream():
5080 * pledgedSrcSize == 0 means "unknown" */
5081size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pss)
5082{
5083    /* temporary : 0 interpreted as "unknown" during transition period.
5084     * Users willing to specify "unknown" **must** use ZSTD_CONTENTSIZE_UNKNOWN.
5085     * 0 will be interpreted as "empty" in the future.
5086     */
5087    U64 const pledgedSrcSize = (pss==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
5088    DEBUGLOG(4, "ZSTD_resetCStream: pledgedSrcSize = %u", (unsigned)pledgedSrcSize);
5089    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5090    FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) , "");
5091    return 0;
5092}
5093
5094/*! ZSTD_initCStream_internal() :
5095 *  Note : for lib/compress only. Used by zstdmt_compress.c.
5096 *  Assumption 1 : params are valid
5097 *  Assumption 2 : either dict, or cdict, is defined, not both */
5098size_t ZSTD_initCStream_internal(ZSTD_CStream* zcs,
5099                    const void* dict, size_t dictSize, const ZSTD_CDict* cdict,
5100                    const ZSTD_CCtx_params* params,
5101                    unsigned long long pledgedSrcSize)
5102{
5103    DEBUGLOG(4, "ZSTD_initCStream_internal");
5104    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5105    FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) , "");
5106    assert(!ZSTD_isError(ZSTD_checkCParams(params->cParams)));
5107    zcs->requestedParams = *params;
5108    assert(!((dict) && (cdict)));  /* either dict or cdict, not both */
5109    if (dict) {
5110        FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) , "");
5111    } else {
5112        /* Dictionary is cleared if !cdict */
5113        FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) , "");
5114    }
5115    return 0;
5116}
5117
5118/* ZSTD_initCStream_usingCDict_advanced() :
5119 * same as ZSTD_initCStream_usingCDict(), with control over frame parameters */
5120size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs,
5121                                            const ZSTD_CDict* cdict,
5122                                            ZSTD_frameParameters fParams,
5123                                            unsigned long long pledgedSrcSize)
5124{
5125    DEBUGLOG(4, "ZSTD_initCStream_usingCDict_advanced");
5126    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5127    FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) , "");
5128    zcs->requestedParams.fParams = fParams;
5129    FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) , "");
5130    return 0;
5131}
5132
5133/* note : cdict must outlive compression session */
5134size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict)
5135{
5136    DEBUGLOG(4, "ZSTD_initCStream_usingCDict");
5137    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5138    FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, cdict) , "");
5139    return 0;
5140}
5141
5142
5143/* ZSTD_initCStream_advanced() :
5144 * pledgedSrcSize must be exact.
5145 * if srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN.
5146 * dict is loaded with default parameters ZSTD_dct_auto and ZSTD_dlm_byCopy. */
5147size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
5148                                 const void* dict, size_t dictSize,
5149                                 ZSTD_parameters params, unsigned long long pss)
5150{
5151    /* for compatibility with older programs relying on this behavior.
5152     * Users should now specify ZSTD_CONTENTSIZE_UNKNOWN.
5153     * This line will be removed in the future.
5154     */
5155    U64 const pledgedSrcSize = (pss==0 && params.fParams.contentSizeFlag==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
5156    DEBUGLOG(4, "ZSTD_initCStream_advanced");
5157    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5158    FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) , "");
5159    FORWARD_IF_ERROR( ZSTD_checkCParams(params.cParams) , "");
5160    ZSTD_CCtxParams_setZstdParams(&zcs->requestedParams, &params);
5161    FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) , "");
5162    return 0;
5163}
5164
5165size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel)
5166{
5167    DEBUGLOG(4, "ZSTD_initCStream_usingDict");
5168    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5169    FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) , "");
5170    FORWARD_IF_ERROR( ZSTD_CCtx_loadDictionary(zcs, dict, dictSize) , "");
5171    return 0;
5172}
5173
5174size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pss)
5175{
5176    /* temporary : 0 interpreted as "unknown" during transition period.
5177     * Users willing to specify "unknown" **must** use ZSTD_CONTENTSIZE_UNKNOWN.
5178     * 0 will be interpreted as "empty" in the future.
5179     */
5180    U64 const pledgedSrcSize = (pss==0) ? ZSTD_CONTENTSIZE_UNKNOWN : pss;
5181    DEBUGLOG(4, "ZSTD_initCStream_srcSize");
5182    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5183    FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, NULL) , "");
5184    FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) , "");
5185    FORWARD_IF_ERROR( ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize) , "");
5186    return 0;
5187}
5188
5189size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel)
5190{
5191    DEBUGLOG(4, "ZSTD_initCStream");
5192    FORWARD_IF_ERROR( ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only) , "");
5193    FORWARD_IF_ERROR( ZSTD_CCtx_refCDict(zcs, NULL) , "");
5194    FORWARD_IF_ERROR( ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel) , "");
5195    return 0;
5196}
5197
5198/*======   Compression   ======*/
5199
5200static size_t ZSTD_nextInputSizeHint(const ZSTD_CCtx* cctx)
5201{
5202    size_t hintInSize = cctx->inBuffTarget - cctx->inBuffPos;
5203    if (hintInSize==0) hintInSize = cctx->blockSize;
5204    return hintInSize;
5205}
5206
5207/* ZSTD_compressStream_generic():
5208 *  internal function for all *compressStream*() variants
5209 *  non-static, because can be called from zstdmt_compress.c
5210 * @return : hint size for next input */
5211static size_t ZSTD_compressStream_generic(ZSTD_CStream* zcs,
5212                                          ZSTD_outBuffer* output,
5213                                          ZSTD_inBuffer* input,
5214                                          ZSTD_EndDirective const flushMode)
5215{
5216    const char* const istart = (const char*)input->src;
5217    const char* const iend = input->size != 0 ? istart + input->size : istart;
5218    const char* ip = input->pos != 0 ? istart + input->pos : istart;
5219    char* const ostart = (char*)output->dst;
5220    char* const oend = output->size != 0 ? ostart + output->size : ostart;
5221    char* op = output->pos != 0 ? ostart + output->pos : ostart;
5222    U32 someMoreWork = 1;
5223
5224    /* check expectations */
5225    DEBUGLOG(5, "ZSTD_compressStream_generic, flush=%u", (unsigned)flushMode);
5226    if (zcs->appliedParams.inBufferMode == ZSTD_bm_buffered) {
5227        assert(zcs->inBuff != NULL);
5228        assert(zcs->inBuffSize > 0);
5229    }
5230    if (zcs->appliedParams.outBufferMode == ZSTD_bm_buffered) {
5231        assert(zcs->outBuff !=  NULL);
5232        assert(zcs->outBuffSize > 0);
5233    }
5234    assert(output->pos <= output->size);
5235    assert(input->pos <= input->size);
5236    assert((U32)flushMode <= (U32)ZSTD_e_end);
5237
5238    while (someMoreWork) {
5239        switch(zcs->streamStage)
5240        {
5241        case zcss_init:
5242            RETURN_ERROR(init_missing, "call ZSTD_initCStream() first!");
5243
5244        case zcss_load:
5245            if ( (flushMode == ZSTD_e_end)
5246              && ( (size_t)(oend-op) >= ZSTD_compressBound(iend-ip)     /* Enough output space */
5247                || zcs->appliedParams.outBufferMode == ZSTD_bm_stable)  /* OR we are allowed to return dstSizeTooSmall */
5248              && (zcs->inBuffPos == 0) ) {
5249                /* shortcut to compression pass directly into output buffer */
5250                size_t const cSize = ZSTD_compressEnd(zcs,
5251                                                op, oend-op, ip, iend-ip);
5252                DEBUGLOG(4, "ZSTD_compressEnd : cSize=%u", (unsigned)cSize);
5253                FORWARD_IF_ERROR(cSize, "ZSTD_compressEnd failed");
5254                ip = iend;
5255                op += cSize;
5256                zcs->frameEnded = 1;
5257                ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
5258                someMoreWork = 0; break;
5259            }
5260            /* complete loading into inBuffer in buffered mode */
5261            if (zcs->appliedParams.inBufferMode == ZSTD_bm_buffered) {
5262                size_t const toLoad = zcs->inBuffTarget - zcs->inBuffPos;
5263                size_t const loaded = ZSTD_limitCopy(
5264                                        zcs->inBuff + zcs->inBuffPos, toLoad,
5265                                        ip, iend-ip);
5266                zcs->inBuffPos += loaded;
5267                if (loaded != 0)
5268                    ip += loaded;
5269                if ( (flushMode == ZSTD_e_continue)
5270                  && (zcs->inBuffPos < zcs->inBuffTarget) ) {
5271                    /* not enough input to fill full block : stop here */
5272                    someMoreWork = 0; break;
5273                }
5274                if ( (flushMode == ZSTD_e_flush)
5275                  && (zcs->inBuffPos == zcs->inToCompress) ) {
5276                    /* empty */
5277                    someMoreWork = 0; break;
5278                }
5279            }
5280            /* compress current block (note : this stage cannot be stopped in the middle) */
5281            DEBUGLOG(5, "stream compression stage (flushMode==%u)", flushMode);
5282            {   int const inputBuffered = (zcs->appliedParams.inBufferMode == ZSTD_bm_buffered);
5283                void* cDst;
5284                size_t cSize;
5285                size_t oSize = oend-op;
5286                size_t const iSize = inputBuffered
5287                    ? zcs->inBuffPos - zcs->inToCompress
5288                    : MIN((size_t)(iend - ip), zcs->blockSize);
5289                if (oSize >= ZSTD_compressBound(iSize) || zcs->appliedParams.outBufferMode == ZSTD_bm_stable)
5290                    cDst = op;   /* compress into output buffer, to skip flush stage */
5291                else
5292                    cDst = zcs->outBuff, oSize = zcs->outBuffSize;
5293                if (inputBuffered) {
5294                    unsigned const lastBlock = (flushMode == ZSTD_e_end) && (ip==iend);
5295                    cSize = lastBlock ?
5296                            ZSTD_compressEnd(zcs, cDst, oSize,
5297                                        zcs->inBuff + zcs->inToCompress, iSize) :
5298                            ZSTD_compressContinue(zcs, cDst, oSize,
5299                                        zcs->inBuff + zcs->inToCompress, iSize);
5300                    FORWARD_IF_ERROR(cSize, "%s", lastBlock ? "ZSTD_compressEnd failed" : "ZSTD_compressContinue failed");
5301                    zcs->frameEnded = lastBlock;
5302                    /* prepare next block */
5303                    zcs->inBuffTarget = zcs->inBuffPos + zcs->blockSize;
5304                    if (zcs->inBuffTarget > zcs->inBuffSize)
5305                        zcs->inBuffPos = 0, zcs->inBuffTarget = zcs->blockSize;
5306                    DEBUGLOG(5, "inBuffTarget:%u / inBuffSize:%u",
5307                            (unsigned)zcs->inBuffTarget, (unsigned)zcs->inBuffSize);
5308                    if (!lastBlock)
5309                        assert(zcs->inBuffTarget <= zcs->inBuffSize);
5310                    zcs->inToCompress = zcs->inBuffPos;
5311                } else {
5312                    unsigned const lastBlock = (ip + iSize == iend);
5313                    assert(flushMode == ZSTD_e_end /* Already validated */);
5314                    cSize = lastBlock ?
5315                            ZSTD_compressEnd(zcs, cDst, oSize, ip, iSize) :
5316                            ZSTD_compressContinue(zcs, cDst, oSize, ip, iSize);
5317                    /* Consume the input prior to error checking to mirror buffered mode. */
5318                    if (iSize > 0)
5319                        ip += iSize;
5320                    FORWARD_IF_ERROR(cSize, "%s", lastBlock ? "ZSTD_compressEnd failed" : "ZSTD_compressContinue failed");
5321                    zcs->frameEnded = lastBlock;
5322                    if (lastBlock)
5323                        assert(ip == iend);
5324                }
5325                if (cDst == op) {  /* no need to flush */
5326                    op += cSize;
5327                    if (zcs->frameEnded) {
5328                        DEBUGLOG(5, "Frame completed directly in outBuffer");
5329                        someMoreWork = 0;
5330                        ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
5331                    }
5332                    break;
5333                }
5334                zcs->outBuffContentSize = cSize;
5335                zcs->outBuffFlushedSize = 0;
5336                zcs->streamStage = zcss_flush; /* pass-through to flush stage */
5337            }
5338	    ZSTD_FALLTHROUGH;
5339        case zcss_flush:
5340            DEBUGLOG(5, "flush stage");
5341            assert(zcs->appliedParams.outBufferMode == ZSTD_bm_buffered);
5342            {   size_t const toFlush = zcs->outBuffContentSize - zcs->outBuffFlushedSize;
5343                size_t const flushed = ZSTD_limitCopy(op, (size_t)(oend-op),
5344                            zcs->outBuff + zcs->outBuffFlushedSize, toFlush);
5345                DEBUGLOG(5, "toFlush: %u into %u ==> flushed: %u",
5346                            (unsigned)toFlush, (unsigned)(oend-op), (unsigned)flushed);
5347                if (flushed)
5348                    op += flushed;
5349                zcs->outBuffFlushedSize += flushed;
5350                if (toFlush!=flushed) {
5351                    /* flush not fully completed, presumably because dst is too small */
5352                    assert(op==oend);
5353                    someMoreWork = 0;
5354                    break;
5355                }
5356                zcs->outBuffContentSize = zcs->outBuffFlushedSize = 0;
5357                if (zcs->frameEnded) {
5358                    DEBUGLOG(5, "Frame completed on flush");
5359                    someMoreWork = 0;
5360                    ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
5361                    break;
5362                }
5363                zcs->streamStage = zcss_load;
5364                break;
5365            }
5366
5367        default: /* impossible */
5368            assert(0);
5369        }
5370    }
5371
5372    input->pos = ip - istart;
5373    output->pos = op - ostart;
5374    if (zcs->frameEnded) return 0;
5375    return ZSTD_nextInputSizeHint(zcs);
5376}
5377
5378static size_t ZSTD_nextInputSizeHint_MTorST(const ZSTD_CCtx* cctx)
5379{
5380    return ZSTD_nextInputSizeHint(cctx);
5381
5382}
5383
5384size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
5385{
5386    FORWARD_IF_ERROR( ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue) , "");
5387    return ZSTD_nextInputSizeHint_MTorST(zcs);
5388}
5389
5390/* After a compression call set the expected input/output buffer.
5391 * This is validated at the start of the next compression call.
5392 */
5393static void ZSTD_setBufferExpectations(ZSTD_CCtx* cctx, ZSTD_outBuffer const* output, ZSTD_inBuffer const* input)
5394{
5395    if (cctx->appliedParams.inBufferMode == ZSTD_bm_stable) {
5396        cctx->expectedInBuffer = *input;
5397    }
5398    if (cctx->appliedParams.outBufferMode == ZSTD_bm_stable) {
5399        cctx->expectedOutBufferSize = output->size - output->pos;
5400    }
5401}
5402
5403/* Validate that the input/output buffers match the expectations set by
5404 * ZSTD_setBufferExpectations.
5405 */
5406static size_t ZSTD_checkBufferStability(ZSTD_CCtx const* cctx,
5407                                        ZSTD_outBuffer const* output,
5408                                        ZSTD_inBuffer const* input,
5409                                        ZSTD_EndDirective endOp)
5410{
5411    if (cctx->appliedParams.inBufferMode == ZSTD_bm_stable) {
5412        ZSTD_inBuffer const expect = cctx->expectedInBuffer;
5413        if (expect.src != input->src || expect.pos != input->pos || expect.size != input->size)
5414            RETURN_ERROR(srcBuffer_wrong, "ZSTD_c_stableInBuffer enabled but input differs!");
5415        if (endOp != ZSTD_e_end)
5416            RETURN_ERROR(srcBuffer_wrong, "ZSTD_c_stableInBuffer can only be used with ZSTD_e_end!");
5417    }
5418    if (cctx->appliedParams.outBufferMode == ZSTD_bm_stable) {
5419        size_t const outBufferSize = output->size - output->pos;
5420        if (cctx->expectedOutBufferSize != outBufferSize)
5421            RETURN_ERROR(dstBuffer_wrong, "ZSTD_c_stableOutBuffer enabled but output size differs!");
5422    }
5423    return 0;
5424}
5425
5426static size_t ZSTD_CCtx_init_compressStream2(ZSTD_CCtx* cctx,
5427                                             ZSTD_EndDirective endOp,
5428                                             size_t inSize) {
5429    ZSTD_CCtx_params params = cctx->requestedParams;
5430    ZSTD_prefixDict const prefixDict = cctx->prefixDict;
5431    FORWARD_IF_ERROR( ZSTD_initLocalDict(cctx) , ""); /* Init the local dict if present. */
5432    ZSTD_memset(&cctx->prefixDict, 0, sizeof(cctx->prefixDict));   /* single usage */
5433    assert(prefixDict.dict==NULL || cctx->cdict==NULL);    /* only one can be set */
5434    if (cctx->cdict && !cctx->localDict.cdict) {
5435        /* Let the cdict's compression level take priority over the requested params.
5436         * But do not take the cdict's compression level if the "cdict" is actually a localDict
5437         * generated from ZSTD_initLocalDict().
5438         */
5439        params.compressionLevel = cctx->cdict->compressionLevel;
5440    }
5441    DEBUGLOG(4, "ZSTD_compressStream2 : transparent init stage");
5442    if (endOp == ZSTD_e_end) cctx->pledgedSrcSizePlusOne = inSize + 1;  /* auto-fix pledgedSrcSize */
5443    {
5444        size_t const dictSize = prefixDict.dict
5445                ? prefixDict.dictSize
5446                : (cctx->cdict ? cctx->cdict->dictContentSize : 0);
5447        ZSTD_cParamMode_e const mode = ZSTD_getCParamMode(cctx->cdict, &params, cctx->pledgedSrcSizePlusOne - 1);
5448        params.cParams = ZSTD_getCParamsFromCCtxParams(
5449                &params, cctx->pledgedSrcSizePlusOne-1,
5450                dictSize, mode);
5451    }
5452
5453    params.useBlockSplitter = ZSTD_resolveBlockSplitterMode(params.useBlockSplitter, &params.cParams);
5454    params.ldmParams.enableLdm = ZSTD_resolveEnableLdm(params.ldmParams.enableLdm, &params.cParams);
5455    params.useRowMatchFinder = ZSTD_resolveRowMatchFinderMode(params.useRowMatchFinder, &params.cParams);
5456
5457    {   U64 const pledgedSrcSize = cctx->pledgedSrcSizePlusOne - 1;
5458        assert(!ZSTD_isError(ZSTD_checkCParams(params.cParams)));
5459        FORWARD_IF_ERROR( ZSTD_compressBegin_internal(cctx,
5460                prefixDict.dict, prefixDict.dictSize, prefixDict.dictContentType, ZSTD_dtlm_fast,
5461                cctx->cdict,
5462                &params, pledgedSrcSize,
5463                ZSTDb_buffered) , "");
5464        assert(cctx->appliedParams.nbWorkers == 0);
5465        cctx->inToCompress = 0;
5466        cctx->inBuffPos = 0;
5467        if (cctx->appliedParams.inBufferMode == ZSTD_bm_buffered) {
5468            /* for small input: avoid automatic flush on reaching end of block, since
5469            * it would require to add a 3-bytes null block to end frame
5470            */
5471            cctx->inBuffTarget = cctx->blockSize + (cctx->blockSize == pledgedSrcSize);
5472        } else {
5473            cctx->inBuffTarget = 0;
5474        }
5475        cctx->outBuffContentSize = cctx->outBuffFlushedSize = 0;
5476        cctx->streamStage = zcss_load;
5477        cctx->frameEnded = 0;
5478    }
5479    return 0;
5480}
5481
5482size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
5483                             ZSTD_outBuffer* output,
5484                             ZSTD_inBuffer* input,
5485                             ZSTD_EndDirective endOp)
5486{
5487    DEBUGLOG(5, "ZSTD_compressStream2, endOp=%u ", (unsigned)endOp);
5488    /* check conditions */
5489    RETURN_ERROR_IF(output->pos > output->size, dstSize_tooSmall, "invalid output buffer");
5490    RETURN_ERROR_IF(input->pos  > input->size, srcSize_wrong, "invalid input buffer");
5491    RETURN_ERROR_IF((U32)endOp > (U32)ZSTD_e_end, parameter_outOfBound, "invalid endDirective");
5492    assert(cctx != NULL);
5493
5494    /* transparent initialization stage */
5495    if (cctx->streamStage == zcss_init) {
5496        FORWARD_IF_ERROR(ZSTD_CCtx_init_compressStream2(cctx, endOp, input->size), "CompressStream2 initialization failed");
5497        ZSTD_setBufferExpectations(cctx, output, input);    /* Set initial buffer expectations now that we've initialized */
5498    }
5499    /* end of transparent initialization stage */
5500
5501    FORWARD_IF_ERROR(ZSTD_checkBufferStability(cctx, output, input, endOp), "invalid buffers");
5502    /* compression stage */
5503    FORWARD_IF_ERROR( ZSTD_compressStream_generic(cctx, output, input, endOp) , "");
5504    DEBUGLOG(5, "completed ZSTD_compressStream2");
5505    ZSTD_setBufferExpectations(cctx, output, input);
5506    return cctx->outBuffContentSize - cctx->outBuffFlushedSize; /* remaining to flush */
5507}
5508
5509size_t ZSTD_compressStream2_simpleArgs (
5510                            ZSTD_CCtx* cctx,
5511                            void* dst, size_t dstCapacity, size_t* dstPos,
5512                      const void* src, size_t srcSize, size_t* srcPos,
5513                            ZSTD_EndDirective endOp)
5514{
5515    ZSTD_outBuffer output = { dst, dstCapacity, *dstPos };
5516    ZSTD_inBuffer  input  = { src, srcSize, *srcPos };
5517    /* ZSTD_compressStream2() will check validity of dstPos and srcPos */
5518    size_t const cErr = ZSTD_compressStream2(cctx, &output, &input, endOp);
5519    *dstPos = output.pos;
5520    *srcPos = input.pos;
5521    return cErr;
5522}
5523
5524size_t ZSTD_compress2(ZSTD_CCtx* cctx,
5525                      void* dst, size_t dstCapacity,
5526                      const void* src, size_t srcSize)
5527{
5528    ZSTD_bufferMode_e const originalInBufferMode = cctx->requestedParams.inBufferMode;
5529    ZSTD_bufferMode_e const originalOutBufferMode = cctx->requestedParams.outBufferMode;
5530    DEBUGLOG(4, "ZSTD_compress2 (srcSize=%u)", (unsigned)srcSize);
5531    ZSTD_CCtx_reset(cctx, ZSTD_reset_session_only);
5532    /* Enable stable input/output buffers. */
5533    cctx->requestedParams.inBufferMode = ZSTD_bm_stable;
5534    cctx->requestedParams.outBufferMode = ZSTD_bm_stable;
5535    {   size_t oPos = 0;
5536        size_t iPos = 0;
5537        size_t const result = ZSTD_compressStream2_simpleArgs(cctx,
5538                                        dst, dstCapacity, &oPos,
5539                                        src, srcSize, &iPos,
5540                                        ZSTD_e_end);
5541        /* Reset to the original values. */
5542        cctx->requestedParams.inBufferMode = originalInBufferMode;
5543        cctx->requestedParams.outBufferMode = originalOutBufferMode;
5544        FORWARD_IF_ERROR(result, "ZSTD_compressStream2_simpleArgs failed");
5545        if (result != 0) {  /* compression not completed, due to lack of output space */
5546            assert(oPos == dstCapacity);
5547            RETURN_ERROR(dstSize_tooSmall, "");
5548        }
5549        assert(iPos == srcSize);   /* all input is expected consumed */
5550        return oPos;
5551    }
5552}
5553
5554typedef struct {
5555    U32 idx;             /* Index in array of ZSTD_Sequence */
5556    U32 posInSequence;   /* Position within sequence at idx */
5557    size_t posInSrc;        /* Number of bytes given by sequences provided so far */
5558} ZSTD_sequencePosition;
5559
5560/* ZSTD_validateSequence() :
5561 * @offCode : is presumed to follow format required by ZSTD_storeSeq()
5562 * @returns a ZSTD error code if sequence is not valid
5563 */
5564static size_t
5565ZSTD_validateSequence(U32 offCode, U32 matchLength,
5566                      size_t posInSrc, U32 windowLog, size_t dictSize)
5567{
5568    U32 const windowSize = 1 << windowLog;
5569    /* posInSrc represents the amount of data the decoder would decode up to this point.
5570     * As long as the amount of data decoded is less than or equal to window size, offsets may be
5571     * larger than the total length of output decoded in order to reference the dict, even larger than
5572     * window size. After output surpasses windowSize, we're limited to windowSize offsets again.
5573     */
5574    size_t const offsetBound = posInSrc > windowSize ? (size_t)windowSize : posInSrc + (size_t)dictSize;
5575    RETURN_ERROR_IF(offCode > STORE_OFFSET(offsetBound), corruption_detected, "Offset too large!");
5576    RETURN_ERROR_IF(matchLength < MINMATCH, corruption_detected, "Matchlength too small");
5577    return 0;
5578}
5579
5580/* Returns an offset code, given a sequence's raw offset, the ongoing repcode array, and whether litLength == 0 */
5581static U32 ZSTD_finalizeOffCode(U32 rawOffset, const U32 rep[ZSTD_REP_NUM], U32 ll0)
5582{
5583    U32 offCode = STORE_OFFSET(rawOffset);
5584
5585    if (!ll0 && rawOffset == rep[0]) {
5586        offCode = STORE_REPCODE_1;
5587    } else if (rawOffset == rep[1]) {
5588        offCode = STORE_REPCODE(2 - ll0);
5589    } else if (rawOffset == rep[2]) {
5590        offCode = STORE_REPCODE(3 - ll0);
5591    } else if (ll0 && rawOffset == rep[0] - 1) {
5592        offCode = STORE_REPCODE_3;
5593    }
5594    return offCode;
5595}
5596
5597/* Returns 0 on success, and a ZSTD_error otherwise. This function scans through an array of
5598 * ZSTD_Sequence, storing the sequences it finds, until it reaches a block delimiter.
5599 */
5600static size_t
5601ZSTD_copySequencesToSeqStoreExplicitBlockDelim(ZSTD_CCtx* cctx,
5602                                              ZSTD_sequencePosition* seqPos,
5603                                        const ZSTD_Sequence* const inSeqs, size_t inSeqsSize,
5604                                        const void* src, size_t blockSize)
5605{
5606    U32 idx = seqPos->idx;
5607    BYTE const* ip = (BYTE const*)(src);
5608    const BYTE* const iend = ip + blockSize;
5609    repcodes_t updatedRepcodes;
5610    U32 dictSize;
5611
5612    if (cctx->cdict) {
5613        dictSize = (U32)cctx->cdict->dictContentSize;
5614    } else if (cctx->prefixDict.dict) {
5615        dictSize = (U32)cctx->prefixDict.dictSize;
5616    } else {
5617        dictSize = 0;
5618    }
5619    ZSTD_memcpy(updatedRepcodes.rep, cctx->blockState.prevCBlock->rep, sizeof(repcodes_t));
5620    for (; (inSeqs[idx].matchLength != 0 || inSeqs[idx].offset != 0) && idx < inSeqsSize; ++idx) {
5621        U32 const litLength = inSeqs[idx].litLength;
5622        U32 const ll0 = (litLength == 0);
5623        U32 const matchLength = inSeqs[idx].matchLength;
5624        U32 const offCode = ZSTD_finalizeOffCode(inSeqs[idx].offset, updatedRepcodes.rep, ll0);
5625        ZSTD_updateRep(updatedRepcodes.rep, offCode, ll0);
5626
5627        DEBUGLOG(6, "Storing sequence: (of: %u, ml: %u, ll: %u)", offCode, matchLength, litLength);
5628        if (cctx->appliedParams.validateSequences) {
5629            seqPos->posInSrc += litLength + matchLength;
5630            FORWARD_IF_ERROR(ZSTD_validateSequence(offCode, matchLength, seqPos->posInSrc,
5631                                                cctx->appliedParams.cParams.windowLog, dictSize),
5632                                                "Sequence validation failed");
5633        }
5634        RETURN_ERROR_IF(idx - seqPos->idx > cctx->seqStore.maxNbSeq, memory_allocation,
5635                        "Not enough memory allocated. Try adjusting ZSTD_c_minMatch.");
5636        ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offCode, matchLength);
5637        ip += matchLength + litLength;
5638    }
5639    ZSTD_memcpy(cctx->blockState.nextCBlock->rep, updatedRepcodes.rep, sizeof(repcodes_t));
5640
5641    if (inSeqs[idx].litLength) {
5642        DEBUGLOG(6, "Storing last literals of size: %u", inSeqs[idx].litLength);
5643        ZSTD_storeLastLiterals(&cctx->seqStore, ip, inSeqs[idx].litLength);
5644        ip += inSeqs[idx].litLength;
5645        seqPos->posInSrc += inSeqs[idx].litLength;
5646    }
5647    RETURN_ERROR_IF(ip != iend, corruption_detected, "Blocksize doesn't agree with block delimiter!");
5648    seqPos->idx = idx+1;
5649    return 0;
5650}
5651
5652/* Returns the number of bytes to move the current read position back by. Only non-zero
5653 * if we ended up splitting a sequence. Otherwise, it may return a ZSTD error if something
5654 * went wrong.
5655 *
5656 * This function will attempt to scan through blockSize bytes represented by the sequences
5657 * in inSeqs, storing any (partial) sequences.
5658 *
5659 * Occasionally, we may want to change the actual number of bytes we consumed from inSeqs to
5660 * avoid splitting a match, or to avoid splitting a match such that it would produce a match
5661 * smaller than MINMATCH. In this case, we return the number of bytes that we didn't read from this block.
5662 */
5663static size_t
5664ZSTD_copySequencesToSeqStoreNoBlockDelim(ZSTD_CCtx* cctx, ZSTD_sequencePosition* seqPos,
5665                                   const ZSTD_Sequence* const inSeqs, size_t inSeqsSize,
5666                                   const void* src, size_t blockSize)
5667{
5668    U32 idx = seqPos->idx;
5669    U32 startPosInSequence = seqPos->posInSequence;
5670    U32 endPosInSequence = seqPos->posInSequence + (U32)blockSize;
5671    size_t dictSize;
5672    BYTE const* ip = (BYTE const*)(src);
5673    BYTE const* iend = ip + blockSize;  /* May be adjusted if we decide to process fewer than blockSize bytes */
5674    repcodes_t updatedRepcodes;
5675    U32 bytesAdjustment = 0;
5676    U32 finalMatchSplit = 0;
5677
5678    if (cctx->cdict) {
5679        dictSize = cctx->cdict->dictContentSize;
5680    } else if (cctx->prefixDict.dict) {
5681        dictSize = cctx->prefixDict.dictSize;
5682    } else {
5683        dictSize = 0;
5684    }
5685    DEBUGLOG(5, "ZSTD_copySequencesToSeqStore: idx: %u PIS: %u blockSize: %zu", idx, startPosInSequence, blockSize);
5686    DEBUGLOG(5, "Start seq: idx: %u (of: %u ml: %u ll: %u)", idx, inSeqs[idx].offset, inSeqs[idx].matchLength, inSeqs[idx].litLength);
5687    ZSTD_memcpy(updatedRepcodes.rep, cctx->blockState.prevCBlock->rep, sizeof(repcodes_t));
5688    while (endPosInSequence && idx < inSeqsSize && !finalMatchSplit) {
5689        const ZSTD_Sequence currSeq = inSeqs[idx];
5690        U32 litLength = currSeq.litLength;
5691        U32 matchLength = currSeq.matchLength;
5692        U32 const rawOffset = currSeq.offset;
5693        U32 offCode;
5694
5695        /* Modify the sequence depending on where endPosInSequence lies */
5696        if (endPosInSequence >= currSeq.litLength + currSeq.matchLength) {
5697            if (startPosInSequence >= litLength) {
5698                startPosInSequence -= litLength;
5699                litLength = 0;
5700                matchLength -= startPosInSequence;
5701            } else {
5702                litLength -= startPosInSequence;
5703            }
5704            /* Move to the next sequence */
5705            endPosInSequence -= currSeq.litLength + currSeq.matchLength;
5706            startPosInSequence = 0;
5707            idx++;
5708        } else {
5709            /* This is the final (partial) sequence we're adding from inSeqs, and endPosInSequence
5710               does not reach the end of the match. So, we have to split the sequence */
5711            DEBUGLOG(6, "Require a split: diff: %u, idx: %u PIS: %u",
5712                     currSeq.litLength + currSeq.matchLength - endPosInSequence, idx, endPosInSequence);
5713            if (endPosInSequence > litLength) {
5714                U32 firstHalfMatchLength;
5715                litLength = startPosInSequence >= litLength ? 0 : litLength - startPosInSequence;
5716                firstHalfMatchLength = endPosInSequence - startPosInSequence - litLength;
5717                if (matchLength > blockSize && firstHalfMatchLength >= cctx->appliedParams.cParams.minMatch) {
5718                    /* Only ever split the match if it is larger than the block size */
5719                    U32 secondHalfMatchLength = currSeq.matchLength + currSeq.litLength - endPosInSequence;
5720                    if (secondHalfMatchLength < cctx->appliedParams.cParams.minMatch) {
5721                        /* Move the endPosInSequence backward so that it creates match of minMatch length */
5722                        endPosInSequence -= cctx->appliedParams.cParams.minMatch - secondHalfMatchLength;
5723                        bytesAdjustment = cctx->appliedParams.cParams.minMatch - secondHalfMatchLength;
5724                        firstHalfMatchLength -= bytesAdjustment;
5725                    }
5726                    matchLength = firstHalfMatchLength;
5727                    /* Flag that we split the last match - after storing the sequence, exit the loop,
5728                       but keep the value of endPosInSequence */
5729                    finalMatchSplit = 1;
5730                } else {
5731                    /* Move the position in sequence backwards so that we don't split match, and break to store
5732                     * the last literals. We use the original currSeq.litLength as a marker for where endPosInSequence
5733                     * should go. We prefer to do this whenever it is not necessary to split the match, or if doing so
5734                     * would cause the first half of the match to be too small
5735                     */
5736                    bytesAdjustment = endPosInSequence - currSeq.litLength;
5737                    endPosInSequence = currSeq.litLength;
5738                    break;
5739                }
5740            } else {
5741                /* This sequence ends inside the literals, break to store the last literals */
5742                break;
5743            }
5744        }
5745        /* Check if this offset can be represented with a repcode */
5746        {   U32 const ll0 = (litLength == 0);
5747            offCode = ZSTD_finalizeOffCode(rawOffset, updatedRepcodes.rep, ll0);
5748            ZSTD_updateRep(updatedRepcodes.rep, offCode, ll0);
5749        }
5750
5751        if (cctx->appliedParams.validateSequences) {
5752            seqPos->posInSrc += litLength + matchLength;
5753            FORWARD_IF_ERROR(ZSTD_validateSequence(offCode, matchLength, seqPos->posInSrc,
5754                                                   cctx->appliedParams.cParams.windowLog, dictSize),
5755                                                   "Sequence validation failed");
5756        }
5757        DEBUGLOG(6, "Storing sequence: (of: %u, ml: %u, ll: %u)", offCode, matchLength, litLength);
5758        RETURN_ERROR_IF(idx - seqPos->idx > cctx->seqStore.maxNbSeq, memory_allocation,
5759                        "Not enough memory allocated. Try adjusting ZSTD_c_minMatch.");
5760        ZSTD_storeSeq(&cctx->seqStore, litLength, ip, iend, offCode, matchLength);
5761        ip += matchLength + litLength;
5762    }
5763    DEBUGLOG(5, "Ending seq: idx: %u (of: %u ml: %u ll: %u)", idx, inSeqs[idx].offset, inSeqs[idx].matchLength, inSeqs[idx].litLength);
5764    assert(idx == inSeqsSize || endPosInSequence <= inSeqs[idx].litLength + inSeqs[idx].matchLength);
5765    seqPos->idx = idx;
5766    seqPos->posInSequence = endPosInSequence;
5767    ZSTD_memcpy(cctx->blockState.nextCBlock->rep, updatedRepcodes.rep, sizeof(repcodes_t));
5768
5769    iend -= bytesAdjustment;
5770    if (ip != iend) {
5771        /* Store any last literals */
5772        U32 lastLLSize = (U32)(iend - ip);
5773        assert(ip <= iend);
5774        DEBUGLOG(6, "Storing last literals of size: %u", lastLLSize);
5775        ZSTD_storeLastLiterals(&cctx->seqStore, ip, lastLLSize);
5776        seqPos->posInSrc += lastLLSize;
5777    }
5778
5779    return bytesAdjustment;
5780}
5781
5782typedef size_t (*ZSTD_sequenceCopier) (ZSTD_CCtx* cctx, ZSTD_sequencePosition* seqPos,
5783                                       const ZSTD_Sequence* const inSeqs, size_t inSeqsSize,
5784                                       const void* src, size_t blockSize);
5785static ZSTD_sequenceCopier ZSTD_selectSequenceCopier(ZSTD_sequenceFormat_e mode)
5786{
5787    ZSTD_sequenceCopier sequenceCopier = NULL;
5788    assert(ZSTD_cParam_withinBounds(ZSTD_c_blockDelimiters, mode));
5789    if (mode == ZSTD_sf_explicitBlockDelimiters) {
5790        return ZSTD_copySequencesToSeqStoreExplicitBlockDelim;
5791    } else if (mode == ZSTD_sf_noBlockDelimiters) {
5792        return ZSTD_copySequencesToSeqStoreNoBlockDelim;
5793    }
5794    assert(sequenceCopier != NULL);
5795    return sequenceCopier;
5796}
5797
5798/* Compress, block-by-block, all of the sequences given.
5799 *
5800 * Returns the cumulative size of all compressed blocks (including their headers),
5801 * otherwise a ZSTD error.
5802 */
5803static size_t
5804ZSTD_compressSequences_internal(ZSTD_CCtx* cctx,
5805                                void* dst, size_t dstCapacity,
5806                          const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
5807                          const void* src, size_t srcSize)
5808{
5809    size_t cSize = 0;
5810    U32 lastBlock;
5811    size_t blockSize;
5812    size_t compressedSeqsSize;
5813    size_t remaining = srcSize;
5814    ZSTD_sequencePosition seqPos = {0, 0, 0};
5815
5816    BYTE const* ip = (BYTE const*)src;
5817    BYTE* op = (BYTE*)dst;
5818    ZSTD_sequenceCopier const sequenceCopier = ZSTD_selectSequenceCopier(cctx->appliedParams.blockDelimiters);
5819
5820    DEBUGLOG(4, "ZSTD_compressSequences_internal srcSize: %zu, inSeqsSize: %zu", srcSize, inSeqsSize);
5821    /* Special case: empty frame */
5822    if (remaining == 0) {
5823        U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1);
5824        RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall, "No room for empty frame block header");
5825        MEM_writeLE32(op, cBlockHeader24);
5826        op += ZSTD_blockHeaderSize;
5827        dstCapacity -= ZSTD_blockHeaderSize;
5828        cSize += ZSTD_blockHeaderSize;
5829    }
5830
5831    while (remaining) {
5832        size_t cBlockSize;
5833        size_t additionalByteAdjustment;
5834        lastBlock = remaining <= cctx->blockSize;
5835        blockSize = lastBlock ? (U32)remaining : (U32)cctx->blockSize;
5836        ZSTD_resetSeqStore(&cctx->seqStore);
5837        DEBUGLOG(4, "Working on new block. Blocksize: %zu", blockSize);
5838
5839        additionalByteAdjustment = sequenceCopier(cctx, &seqPos, inSeqs, inSeqsSize, ip, blockSize);
5840        FORWARD_IF_ERROR(additionalByteAdjustment, "Bad sequence copy");
5841        blockSize -= additionalByteAdjustment;
5842
5843        /* If blocks are too small, emit as a nocompress block */
5844        if (blockSize < MIN_CBLOCK_SIZE+ZSTD_blockHeaderSize+1) {
5845            cBlockSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
5846            FORWARD_IF_ERROR(cBlockSize, "Nocompress block failed");
5847            DEBUGLOG(4, "Block too small, writing out nocompress block: cSize: %zu", cBlockSize);
5848            cSize += cBlockSize;
5849            ip += blockSize;
5850            op += cBlockSize;
5851            remaining -= blockSize;
5852            dstCapacity -= cBlockSize;
5853            continue;
5854        }
5855
5856        compressedSeqsSize = ZSTD_entropyCompressSeqStore(&cctx->seqStore,
5857                                &cctx->blockState.prevCBlock->entropy, &cctx->blockState.nextCBlock->entropy,
5858                                &cctx->appliedParams,
5859                                op + ZSTD_blockHeaderSize /* Leave space for block header */, dstCapacity - ZSTD_blockHeaderSize,
5860                                blockSize,
5861                                cctx->entropyWorkspace, ENTROPY_WORKSPACE_SIZE /* statically allocated in resetCCtx */,
5862                                cctx->bmi2);
5863        FORWARD_IF_ERROR(compressedSeqsSize, "Compressing sequences of block failed");
5864        DEBUGLOG(4, "Compressed sequences size: %zu", compressedSeqsSize);
5865
5866        if (!cctx->isFirstBlock &&
5867            ZSTD_maybeRLE(&cctx->seqStore) &&
5868            ZSTD_isRLE((BYTE const*)src, srcSize)) {
5869            /* We don't want to emit our first block as a RLE even if it qualifies because
5870            * doing so will cause the decoder (cli only) to throw a "should consume all input error."
5871            * This is only an issue for zstd <= v1.4.3
5872            */
5873            compressedSeqsSize = 1;
5874        }
5875
5876        if (compressedSeqsSize == 0) {
5877            /* ZSTD_noCompressBlock writes the block header as well */
5878            cBlockSize = ZSTD_noCompressBlock(op, dstCapacity, ip, blockSize, lastBlock);
5879            FORWARD_IF_ERROR(cBlockSize, "Nocompress block failed");
5880            DEBUGLOG(4, "Writing out nocompress block, size: %zu", cBlockSize);
5881        } else if (compressedSeqsSize == 1) {
5882            cBlockSize = ZSTD_rleCompressBlock(op, dstCapacity, *ip, blockSize, lastBlock);
5883            FORWARD_IF_ERROR(cBlockSize, "RLE compress block failed");
5884            DEBUGLOG(4, "Writing out RLE block, size: %zu", cBlockSize);
5885        } else {
5886            U32 cBlockHeader;
5887            /* Error checking and repcodes update */
5888            ZSTD_blockState_confirmRepcodesAndEntropyTables(&cctx->blockState);
5889            if (cctx->blockState.prevCBlock->entropy.fse.offcode_repeatMode == FSE_repeat_valid)
5890                cctx->blockState.prevCBlock->entropy.fse.offcode_repeatMode = FSE_repeat_check;
5891
5892            /* Write block header into beginning of block*/
5893            cBlockHeader = lastBlock + (((U32)bt_compressed)<<1) + (U32)(compressedSeqsSize << 3);
5894            MEM_writeLE24(op, cBlockHeader);
5895            cBlockSize = ZSTD_blockHeaderSize + compressedSeqsSize;
5896            DEBUGLOG(4, "Writing out compressed block, size: %zu", cBlockSize);
5897        }
5898
5899        cSize += cBlockSize;
5900        DEBUGLOG(4, "cSize running total: %zu", cSize);
5901
5902        if (lastBlock) {
5903            break;
5904        } else {
5905            ip += blockSize;
5906            op += cBlockSize;
5907            remaining -= blockSize;
5908            dstCapacity -= cBlockSize;
5909            cctx->isFirstBlock = 0;
5910        }
5911    }
5912
5913    return cSize;
5914}
5915
5916size_t ZSTD_compressSequences(ZSTD_CCtx* const cctx, void* dst, size_t dstCapacity,
5917                              const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
5918                              const void* src, size_t srcSize)
5919{
5920    BYTE* op = (BYTE*)dst;
5921    size_t cSize = 0;
5922    size_t compressedBlocksSize = 0;
5923    size_t frameHeaderSize = 0;
5924
5925    /* Transparent initialization stage, same as compressStream2() */
5926    DEBUGLOG(3, "ZSTD_compressSequences()");
5927    assert(cctx != NULL);
5928    FORWARD_IF_ERROR(ZSTD_CCtx_init_compressStream2(cctx, ZSTD_e_end, srcSize), "CCtx initialization failed");
5929    /* Begin writing output, starting with frame header */
5930    frameHeaderSize = ZSTD_writeFrameHeader(op, dstCapacity, &cctx->appliedParams, srcSize, cctx->dictID);
5931    op += frameHeaderSize;
5932    dstCapacity -= frameHeaderSize;
5933    cSize += frameHeaderSize;
5934    if (cctx->appliedParams.fParams.checksumFlag && srcSize) {
5935        xxh64_update(&cctx->xxhState, src, srcSize);
5936    }
5937    /* cSize includes block header size and compressed sequences size */
5938    compressedBlocksSize = ZSTD_compressSequences_internal(cctx,
5939                                                           op, dstCapacity,
5940                                                           inSeqs, inSeqsSize,
5941                                                           src, srcSize);
5942    FORWARD_IF_ERROR(compressedBlocksSize, "Compressing blocks failed!");
5943    cSize += compressedBlocksSize;
5944    dstCapacity -= compressedBlocksSize;
5945
5946    if (cctx->appliedParams.fParams.checksumFlag) {
5947        U32 const checksum = (U32) xxh64_digest(&cctx->xxhState);
5948        RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall, "no room for checksum");
5949        DEBUGLOG(4, "Write checksum : %08X", (unsigned)checksum);
5950        MEM_writeLE32((char*)dst + cSize, checksum);
5951        cSize += 4;
5952    }
5953
5954    DEBUGLOG(3, "Final compressed size: %zu", cSize);
5955    return cSize;
5956}
5957
5958/*======   Finalize   ======*/
5959
5960/*! ZSTD_flushStream() :
5961 * @return : amount of data remaining to flush */
5962size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
5963{
5964    ZSTD_inBuffer input = { NULL, 0, 0 };
5965    return ZSTD_compressStream2(zcs, output, &input, ZSTD_e_flush);
5966}
5967
5968
5969size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output)
5970{
5971    ZSTD_inBuffer input = { NULL, 0, 0 };
5972    size_t const remainingToFlush = ZSTD_compressStream2(zcs, output, &input, ZSTD_e_end);
5973    FORWARD_IF_ERROR( remainingToFlush , "ZSTD_compressStream2 failed");
5974    if (zcs->appliedParams.nbWorkers > 0) return remainingToFlush;   /* minimal estimation */
5975    /* single thread mode : attempt to calculate remaining to flush more precisely */
5976    {   size_t const lastBlockSize = zcs->frameEnded ? 0 : ZSTD_BLOCKHEADERSIZE;
5977        size_t const checksumSize = (size_t)(zcs->frameEnded ? 0 : zcs->appliedParams.fParams.checksumFlag * 4);
5978        size_t const toFlush = remainingToFlush + lastBlockSize + checksumSize;
5979        DEBUGLOG(4, "ZSTD_endStream : remaining to flush : %u", (unsigned)toFlush);
5980        return toFlush;
5981    }
5982}
5983
5984
5985/*-=====  Pre-defined compression levels  =====-*/
5986#include "clevels.h"
5987
5988int ZSTD_maxCLevel(void) { return ZSTD_MAX_CLEVEL; }
5989int ZSTD_minCLevel(void) { return (int)-ZSTD_TARGETLENGTH_MAX; }
5990int ZSTD_defaultCLevel(void) { return ZSTD_CLEVEL_DEFAULT; }
5991
5992static ZSTD_compressionParameters ZSTD_dedicatedDictSearch_getCParams(int const compressionLevel, size_t const dictSize)
5993{
5994    ZSTD_compressionParameters cParams = ZSTD_getCParams_internal(compressionLevel, 0, dictSize, ZSTD_cpm_createCDict);
5995    switch (cParams.strategy) {
5996        case ZSTD_fast:
5997        case ZSTD_dfast:
5998            break;
5999        case ZSTD_greedy:
6000        case ZSTD_lazy:
6001        case ZSTD_lazy2:
6002            cParams.hashLog += ZSTD_LAZY_DDSS_BUCKET_LOG;
6003            break;
6004        case ZSTD_btlazy2:
6005        case ZSTD_btopt:
6006        case ZSTD_btultra:
6007        case ZSTD_btultra2:
6008            break;
6009    }
6010    return cParams;
6011}
6012
6013static int ZSTD_dedicatedDictSearch_isSupported(
6014        ZSTD_compressionParameters const* cParams)
6015{
6016    return (cParams->strategy >= ZSTD_greedy)
6017        && (cParams->strategy <= ZSTD_lazy2)
6018        && (cParams->hashLog > cParams->chainLog)
6019        && (cParams->chainLog <= 24);
6020}
6021
6022/*
6023 * Reverses the adjustment applied to cparams when enabling dedicated dict
6024 * search. This is used to recover the params set to be used in the working
6025 * context. (Otherwise, those tables would also grow.)
6026 */
6027static void ZSTD_dedicatedDictSearch_revertCParams(
6028        ZSTD_compressionParameters* cParams) {
6029    switch (cParams->strategy) {
6030        case ZSTD_fast:
6031        case ZSTD_dfast:
6032            break;
6033        case ZSTD_greedy:
6034        case ZSTD_lazy:
6035        case ZSTD_lazy2:
6036            cParams->hashLog -= ZSTD_LAZY_DDSS_BUCKET_LOG;
6037            if (cParams->hashLog < ZSTD_HASHLOG_MIN) {
6038                cParams->hashLog = ZSTD_HASHLOG_MIN;
6039            }
6040            break;
6041        case ZSTD_btlazy2:
6042        case ZSTD_btopt:
6043        case ZSTD_btultra:
6044        case ZSTD_btultra2:
6045            break;
6046    }
6047}
6048
6049static U64 ZSTD_getCParamRowSize(U64 srcSizeHint, size_t dictSize, ZSTD_cParamMode_e mode)
6050{
6051    switch (mode) {
6052    case ZSTD_cpm_unknown:
6053    case ZSTD_cpm_noAttachDict:
6054    case ZSTD_cpm_createCDict:
6055        break;
6056    case ZSTD_cpm_attachDict:
6057        dictSize = 0;
6058        break;
6059    default:
6060        assert(0);
6061        break;
6062    }
6063    {   int const unknown = srcSizeHint == ZSTD_CONTENTSIZE_UNKNOWN;
6064        size_t const addedSize = unknown && dictSize > 0 ? 500 : 0;
6065        return unknown && dictSize == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : srcSizeHint+dictSize+addedSize;
6066    }
6067}
6068
6069/*! ZSTD_getCParams_internal() :
6070 * @return ZSTD_compressionParameters structure for a selected compression level, srcSize and dictSize.
6071 *  Note: srcSizeHint 0 means 0, use ZSTD_CONTENTSIZE_UNKNOWN for unknown.
6072 *        Use dictSize == 0 for unknown or unused.
6073 *  Note: `mode` controls how we treat the `dictSize`. See docs for `ZSTD_cParamMode_e`. */
6074static ZSTD_compressionParameters ZSTD_getCParams_internal(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize, ZSTD_cParamMode_e mode)
6075{
6076    U64 const rSize = ZSTD_getCParamRowSize(srcSizeHint, dictSize, mode);
6077    U32 const tableID = (rSize <= 256 KB) + (rSize <= 128 KB) + (rSize <= 16 KB);
6078    int row;
6079    DEBUGLOG(5, "ZSTD_getCParams_internal (cLevel=%i)", compressionLevel);
6080
6081    /* row */
6082    if (compressionLevel == 0) row = ZSTD_CLEVEL_DEFAULT;   /* 0 == default */
6083    else if (compressionLevel < 0) row = 0;   /* entry 0 is baseline for fast mode */
6084    else if (compressionLevel > ZSTD_MAX_CLEVEL) row = ZSTD_MAX_CLEVEL;
6085    else row = compressionLevel;
6086
6087    {   ZSTD_compressionParameters cp = ZSTD_defaultCParameters[tableID][row];
6088        DEBUGLOG(5, "ZSTD_getCParams_internal selected tableID: %u row: %u strat: %u", tableID, row, (U32)cp.strategy);
6089        /* acceleration factor */
6090        if (compressionLevel < 0) {
6091            int const clampedCompressionLevel = MAX(ZSTD_minCLevel(), compressionLevel);
6092            cp.targetLength = (unsigned)(-clampedCompressionLevel);
6093        }
6094        /* refine parameters based on srcSize & dictSize */
6095        return ZSTD_adjustCParams_internal(cp, srcSizeHint, dictSize, mode);
6096    }
6097}
6098
6099/*! ZSTD_getCParams() :
6100 * @return ZSTD_compressionParameters structure for a selected compression level, srcSize and dictSize.
6101 *  Size values are optional, provide 0 if not known or unused */
6102ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize)
6103{
6104    if (srcSizeHint == 0) srcSizeHint = ZSTD_CONTENTSIZE_UNKNOWN;
6105    return ZSTD_getCParams_internal(compressionLevel, srcSizeHint, dictSize, ZSTD_cpm_unknown);
6106}
6107
6108/*! ZSTD_getParams() :
6109 *  same idea as ZSTD_getCParams()
6110 * @return a `ZSTD_parameters` structure (instead of `ZSTD_compressionParameters`).
6111 *  Fields of `ZSTD_frameParameters` are set to default values */
6112static ZSTD_parameters ZSTD_getParams_internal(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize, ZSTD_cParamMode_e mode) {
6113    ZSTD_parameters params;
6114    ZSTD_compressionParameters const cParams = ZSTD_getCParams_internal(compressionLevel, srcSizeHint, dictSize, mode);
6115    DEBUGLOG(5, "ZSTD_getParams (cLevel=%i)", compressionLevel);
6116    ZSTD_memset(&params, 0, sizeof(params));
6117    params.cParams = cParams;
6118    params.fParams.contentSizeFlag = 1;
6119    return params;
6120}
6121
6122/*! ZSTD_getParams() :
6123 *  same idea as ZSTD_getCParams()
6124 * @return a `ZSTD_parameters` structure (instead of `ZSTD_compressionParameters`).
6125 *  Fields of `ZSTD_frameParameters` are set to default values */
6126ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSizeHint, size_t dictSize) {
6127    if (srcSizeHint == 0) srcSizeHint = ZSTD_CONTENTSIZE_UNKNOWN;
6128    return ZSTD_getParams_internal(compressionLevel, srcSizeHint, dictSize, ZSTD_cpm_unknown);
6129}