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}

  1// SPDX-License-Identifier: GPL-2.0
  2#include "cache.h"
  3#include "debug.h"
  4#include "strbuf.h"
  5#include <linux/kernel.h>
  6#include <linux/string.h>
  7#include <linux/zalloc.h>
  8#include <errno.h>
  9#include <stdio.h>
 10#include <stdlib.h>
 11#include <unistd.h>
 12
 13/*
 14 * Used as the default ->buf value, so that people can always assume
 15 * buf is non NULL and ->buf is NUL terminated even for a freshly
 16 * initialized strbuf.
 17 */
 18char strbuf_slopbuf[1];
 19
 20int strbuf_init(struct strbuf *sb, ssize_t hint)
 21{
 22	sb->alloc = sb->len = 0;
 23	sb->buf = strbuf_slopbuf;
 24	if (hint)
 25		return strbuf_grow(sb, hint);
 26	return 0;
 27}
 28
 29void strbuf_release(struct strbuf *sb)
 30{
 31	if (sb->alloc) {
 32		zfree(&sb->buf);
 33		strbuf_init(sb, 0);
 34	}
 35}
 36
 37char *strbuf_detach(struct strbuf *sb, size_t *sz)
 38{
 39	char *res = sb->alloc ? sb->buf : NULL;
 40	if (sz)
 41		*sz = sb->len;
 42	strbuf_init(sb, 0);
 43	return res;
 44}
 45
 46int strbuf_grow(struct strbuf *sb, size_t extra)
 47{
 48	char *buf;
 49	size_t nr = sb->len + extra + 1;
 50
 51	if (nr < sb->alloc)
 52		return 0;
 53
 54	if (nr <= sb->len)
 55		return -E2BIG;
 56
 57	if (alloc_nr(sb->alloc) > nr)
 58		nr = alloc_nr(sb->alloc);
 59
 60	/*
 61	 * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is
 62	 * a static variable. Thus we have to avoid passing it to realloc.
 63	 */
 64	buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf));
 65	if (!buf)
 66		return -ENOMEM;
 67
 68	sb->buf = buf;
 69	sb->alloc = nr;
 70	return 0;
 71}
 72
 73int strbuf_addch(struct strbuf *sb, int c)
 74{
 75	int ret = strbuf_grow(sb, 1);
 76	if (ret)
 77		return ret;
 78
 79	sb->buf[sb->len++] = c;
 80	sb->buf[sb->len] = '\0';
 81	return 0;
 82}
 83
 84int strbuf_add(struct strbuf *sb, const void *data, size_t len)
 85{
 86	int ret = strbuf_grow(sb, len);
 87	if (ret)
 88		return ret;
 89
 90	memcpy(sb->buf + sb->len, data, len);
 91	return strbuf_setlen(sb, sb->len + len);
 92}
 93
 94static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
 95{
 96	int len, ret;
 97	va_list ap_saved;
 98
 99	if (!strbuf_avail(sb)) {
100		ret = strbuf_grow(sb, 64);
101		if (ret)
102			return ret;
103	}
104
105	va_copy(ap_saved, ap);
106	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
107	if (len < 0) {
108		va_end(ap_saved);
109		return len;
110	}
111	if (len > strbuf_avail(sb)) {
112		ret = strbuf_grow(sb, len);
113		if (ret) {
114			va_end(ap_saved);
115			return ret;
116		}
117		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
 
118		if (len > strbuf_avail(sb)) {
119			pr_debug("this should not happen, your vsnprintf is broken");
120			va_end(ap_saved);
121			return -EINVAL;
122		}
123	}
124	va_end(ap_saved);
125	return strbuf_setlen(sb, sb->len + len);
126}
127
128int strbuf_addf(struct strbuf *sb, const char *fmt, ...)
129{
130	va_list ap;
131	int ret;
132
133	va_start(ap, fmt);
134	ret = strbuf_addv(sb, fmt, ap);
135	va_end(ap);
136	return ret;
137}
138
139ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
140{
141	size_t oldlen = sb->len;
142	size_t oldalloc = sb->alloc;
143	int ret;
144
145	ret = strbuf_grow(sb, hint ? hint : 8192);
146	if (ret)
147		return ret;
148
149	for (;;) {
150		ssize_t cnt;
151
152		cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
153		if (cnt < 0) {
154			if (oldalloc == 0)
155				strbuf_release(sb);
156			else
157				strbuf_setlen(sb, oldlen);
158			return cnt;
159		}
160		if (!cnt)
161			break;
162		sb->len += cnt;
163		ret = strbuf_grow(sb, 8192);
164		if (ret)
165			return ret;
166	}
167
168	sb->buf[sb->len] = '\0';
169	return sb->len - oldlen;
170}