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v4.6
  1#include "cache.h"
 
 
  2#include <linux/kernel.h>
  3
  4int prefixcmp(const char *str, const char *prefix)
  5{
  6	for (; ; str++, prefix++)
  7		if (!*prefix)
  8			return 0;
  9		else if (*str != *prefix)
 10			return (unsigned char)*prefix - (unsigned char)*str;
 11}
 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
 20void strbuf_init(struct strbuf *sb, ssize_t hint)
 21{
 22	sb->alloc = sb->len = 0;
 23	sb->buf = strbuf_slopbuf;
 24	if (hint)
 25		strbuf_grow(sb, hint);
 
 26}
 27
 28void strbuf_release(struct strbuf *sb)
 29{
 30	if (sb->alloc) {
 31		zfree(&sb->buf);
 32		strbuf_init(sb, 0);
 33	}
 34}
 35
 36char *strbuf_detach(struct strbuf *sb, size_t *sz)
 37{
 38	char *res = sb->alloc ? sb->buf : NULL;
 39	if (sz)
 40		*sz = sb->len;
 41	strbuf_init(sb, 0);
 42	return res;
 43}
 44
 45void strbuf_grow(struct strbuf *sb, size_t extra)
 46{
 47	if (sb->len + extra + 1 <= sb->len)
 48		die("you want to use way too much memory");
 49	if (!sb->alloc)
 50		sb->buf = NULL;
 51	ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 52}
 53
 54void strbuf_addch(struct strbuf *sb, int c)
 55{
 56	strbuf_grow(sb, 1);
 
 
 
 57	sb->buf[sb->len++] = c;
 58	sb->buf[sb->len] = '\0';
 
 59}
 60
 61void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 62{
 63	strbuf_grow(sb, len);
 
 
 
 64	memcpy(sb->buf + sb->len, data, len);
 65	strbuf_setlen(sb, sb->len + len);
 66}
 67
 68static void strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap)
 69{
 70	int len;
 71	va_list ap_saved;
 72
 73	if (!strbuf_avail(sb))
 74		strbuf_grow(sb, 64);
 
 
 
 75
 76	va_copy(ap_saved, ap);
 77	len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 78	if (len < 0)
 79		die("your vsnprintf is broken");
 80	if (len > strbuf_avail(sb)) {
 81		strbuf_grow(sb, len);
 
 
 82		len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved);
 83		va_end(ap_saved);
 84		if (len > strbuf_avail(sb)) {
 85			die("this should not happen, your vsnprintf is broken");
 
 86		}
 87	}
 88	strbuf_setlen(sb, sb->len + len);
 89}
 90
 91void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 92{
 93	va_list ap;
 
 94
 95	va_start(ap, fmt);
 96	strbuf_addv(sb, fmt, ap);
 97	va_end(ap);
 
 98}
 99
100ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
101{
102	size_t oldlen = sb->len;
103	size_t oldalloc = sb->alloc;
 
 
 
 
 
104
105	strbuf_grow(sb, hint ? hint : 8192);
106	for (;;) {
107		ssize_t cnt;
108
109		cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
110		if (cnt < 0) {
111			if (oldalloc == 0)
112				strbuf_release(sb);
113			else
114				strbuf_setlen(sb, oldlen);
115			return -1;
116		}
117		if (!cnt)
118			break;
119		sb->len += cnt;
120		strbuf_grow(sb, 8192);
 
 
121	}
122
123	sb->buf[sb->len] = '\0';
124	return sb->len - oldlen;
125}
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}