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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#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}