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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}
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}