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v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2#include "debug.h"
  3#include "util.h"
  4#include <linux/kernel.h>
  5#include <errno.h>
 
 
 
 
 
  6
  7/*
  8 * Used as the default ->buf value, so that people can always assume
  9 * buf is non NULL and ->buf is NUL terminated even for a freshly
 10 * initialized strbuf.
 11 */
 12char strbuf_slopbuf[1];
 13
 14int strbuf_init(struct strbuf *sb, ssize_t hint)
 15{
 16	sb->alloc = sb->len = 0;
 17	sb->buf = strbuf_slopbuf;
 18	if (hint)
 19		return strbuf_grow(sb, hint);
 20	return 0;
 21}
 22
 23void strbuf_release(struct strbuf *sb)
 24{
 25	if (sb->alloc) {
 26		zfree(&sb->buf);
 27		strbuf_init(sb, 0);
 28	}
 29}
 30
 31char *strbuf_detach(struct strbuf *sb, size_t *sz)
 32{
 33	char *res = sb->alloc ? sb->buf : NULL;
 34	if (sz)
 35		*sz = sb->len;
 36	strbuf_init(sb, 0);
 37	return res;
 38}
 39
 40int strbuf_grow(struct strbuf *sb, size_t extra)
 41{
 42	char *buf;
 43	size_t nr = sb->len + extra + 1;
 44
 45	if (nr < sb->alloc)
 46		return 0;
 47
 48	if (nr <= sb->len)
 49		return -E2BIG;
 50
 51	if (alloc_nr(sb->alloc) > nr)
 52		nr = alloc_nr(sb->alloc);
 53
 54	/*
 55	 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
 56	 * a static variable. Thus we have to avoid passing it to realloc.
 57	 */
 58	buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
 59	if (!buf)
 60		return -ENOMEM;
 61
 62	sb->buf = buf;
 63	sb->alloc = nr;
 64	return 0;
 65}
 66
 67int strbuf_addch(struct strbuf *sb, int c)
 
 68{
 69	int ret = strbuf_grow(sb, 1);
 70	if (ret)
 71		return ret;
 
 
 
 72
 73	sb->buf[sb->len++] = c;
 74	sb->buf[sb->len] = '\0';
 75	return 0;
 
 
 
 
 76}
 77
 78int strbuf_add(struct strbuf *sb, const void *data, size_t len)
 79{
 80	int ret = strbuf_grow(sb, len);
 81	if (ret)
 82		return ret;
 83
 
 
 
 84	memcpy(sb->buf + sb->len, data, len);
 85	return strbuf_setlen(sb, sb->len + len);
 86}
 87
 88static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
 89{
 90	int len, ret;
 91	va_list ap_saved;
 92
 93	if (!strbuf_avail(sb)) {
 94		ret = strbuf_grow(sb, 64);
 95		if (ret)
 96			return ret;
 97	}
 98
 99	va_copy(ap_saved, ap);
 
 
100	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 
101	if (len < 0)
102		return len;
103	if (len > strbuf_avail(sb)) {
104		ret = strbuf_grow(sb, len);
105		if (ret)
106			return ret;
107		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
108		va_end(ap_saved);
109		if (len > strbuf_avail(sb)) {
110			pr_debug("this should not happen, your vsnprintf is broken");
111			return -EINVAL;
112		}
113	}
114	return strbuf_setlen(sb, sb->len + len);
115}
116
117int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
118{
119	va_list ap;
120	int ret;
121
122	va_start(ap, fmt);
123	ret = strbuf_addv(sb, fmt, ap);
124	va_end(ap);
125	return ret;
126}
127
128ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
129{
130	size_t oldlen = sb->len;
131	size_t oldalloc = sb->alloc;
132	int ret;
133
134	ret = strbuf_grow(sb, hint ? hint : 8192);
135	if (ret)
136		return ret;
137
 
138	for (;;) {
139		ssize_t cnt;
140
141		cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
142		if (cnt < 0) {
143			if (oldalloc == 0)
144				strbuf_release(sb);
145			else
146				strbuf_setlen(sb, oldlen);
147			return cnt;
148		}
149		if (!cnt)
150			break;
151		sb->len += cnt;
152		ret = strbuf_grow(sb, 8192);
153		if (ret)
154			return ret;
155	}
156
157	sb->buf[sb->len] = '\0';
158	return sb->len - oldlen;
159}
v3.1
  1#include "cache.h"
  2
  3int prefixcmp(const char *str, const char *prefix)
  4{
  5	for (; ; str++, prefix++)
  6		if (!*prefix)
  7			return 0;
  8		else if (*str != *prefix)
  9			return (unsigned char)*prefix - (unsigned char)*str;
 10}
 11
 12/*
 13 * Used as the default ->buf value, so that people can always assume
 14 * buf is non NULL and ->buf is NUL terminated even for a freshly
 15 * initialized strbuf.
 16 */
 17char strbuf_slopbuf[1];
 18
 19void strbuf_init(struct strbuf *sb, ssize_t hint)
 20{
 21	sb->alloc = sb->len = 0;
 22	sb->buf = strbuf_slopbuf;
 23	if (hint)
 24		strbuf_grow(sb, hint);
 
 25}
 26
 27void strbuf_release(struct strbuf *sb)
 28{
 29	if (sb->alloc) {
 30		free(sb->buf);
 31		strbuf_init(sb, 0);
 32	}
 33}
 34
 35char *strbuf_detach(struct strbuf *sb, size_t *sz)
 36{
 37	char *res = sb->alloc ? sb->buf : NULL;
 38	if (sz)
 39		*sz = sb->len;
 40	strbuf_init(sb, 0);
 41	return res;
 42}
 43
 44void strbuf_grow(struct strbuf *sb, size_t extra)
 45{
 46	if (sb->len + extra + 1 <= sb->len)
 47		die("you want to use way too much memory");
 48	if (!sb->alloc)
 49		sb->buf = NULL;
 50	ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 51}
 52
 53static void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 54				   const void *data, size_t dlen)
 55{
 56	if (pos + len < pos)
 57		die("you want to use way too much memory");
 58	if (pos > sb->len)
 59		die("`pos' is too far after the end of the buffer");
 60	if (pos + len > sb->len)
 61		die("`pos + len' is too far after the end of the buffer");
 62
 63	if (dlen >= len)
 64		strbuf_grow(sb, dlen - len);
 65	memmove(sb->buf + pos + dlen,
 66			sb->buf + pos + len,
 67			sb->len - pos - len);
 68	memcpy(sb->buf + pos, data, dlen);
 69	strbuf_setlen(sb, sb->len + dlen - len);
 70}
 71
 72void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
 73{
 74	strbuf_splice(sb, pos, len, NULL, 0);
 75}
 
 76
 77void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 78{
 79	strbuf_grow(sb, len);
 80	memcpy(sb->buf + sb->len, data, len);
 81	strbuf_setlen(sb, sb->len + len);
 82}
 83
 84void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 85{
 86	int len;
 87	va_list ap;
 
 
 
 
 
 
 88
 89	if (!strbuf_avail(sb))
 90		strbuf_grow(sb, 64);
 91	va_start(ap, fmt);
 92	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 93	va_end(ap);
 94	if (len < 0)
 95		die("your vsnprintf is broken");
 96	if (len > strbuf_avail(sb)) {
 97		strbuf_grow(sb, len);
 98		va_start(ap, fmt);
 99		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
100		va_end(ap);
 
101		if (len > strbuf_avail(sb)) {
102			die("this should not happen, your snprintf is broken");
 
103		}
104	}
105	strbuf_setlen(sb, sb->len + len);
 
 
 
 
 
 
 
 
 
 
 
106}
107
108ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
109{
110	size_t oldlen = sb->len;
111	size_t oldalloc = sb->alloc;
 
 
 
 
 
112
113	strbuf_grow(sb, hint ? hint : 8192);
114	for (;;) {
115		ssize_t cnt;
116
117		cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
118		if (cnt < 0) {
119			if (oldalloc == 0)
120				strbuf_release(sb);
121			else
122				strbuf_setlen(sb, oldlen);
123			return -1;
124		}
125		if (!cnt)
126			break;
127		sb->len += cnt;
128		strbuf_grow(sb, 8192);
 
 
129	}
130
131	sb->buf[sb->len] = '\0';
132	return sb->len - oldlen;
133}