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