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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#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
54static void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
55 const void *data, size_t dlen)
56{
57 if (pos + len < pos)
58 die("you want to use way too much memory");
59 if (pos > sb->len)
60 die("`pos' is too far after the end of the buffer");
61 if (pos + len > sb->len)
62 die("`pos + len' is too far after the end of the buffer");
63
64 if (dlen >= len)
65 strbuf_grow(sb, dlen - len);
66 memmove(sb->buf + pos + dlen,
67 sb->buf + pos + len,
68 sb->len - pos - len);
69 memcpy(sb->buf + pos, data, dlen);
70 strbuf_setlen(sb, sb->len + dlen - len);
71}
72
73void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
74{
75 strbuf_splice(sb, pos, len, NULL, 0);
76}
77
78void strbuf_add(struct strbuf *sb, const void *data, size_t len)
79{
80 strbuf_grow(sb, len);
81 memcpy(sb->buf + sb->len, data, len);
82 strbuf_setlen(sb, sb->len + len);
83}
84
85void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
86{
87 int len;
88 va_list ap;
89
90 if (!strbuf_avail(sb))
91 strbuf_grow(sb, 64);
92 va_start(ap, fmt);
93 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
94 va_end(ap);
95 if (len < 0)
96 die("your vsnprintf is broken");
97 if (len > strbuf_avail(sb)) {
98 strbuf_grow(sb, len);
99 va_start(ap, fmt);
100 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
101 va_end(ap);
102 if (len > strbuf_avail(sb)) {
103 die("this should not happen, your vsnprintf is broken");
104 }
105 }
106 strbuf_setlen(sb, sb->len + len);
107}
108
109ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
110{
111 size_t oldlen = sb->len;
112 size_t oldalloc = sb->alloc;
113
114 strbuf_grow(sb, hint ? hint : 8192);
115 for (;;) {
116 ssize_t cnt;
117
118 cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
119 if (cnt < 0) {
120 if (oldalloc == 0)
121 strbuf_release(sb);
122 else
123 strbuf_setlen(sb, oldlen);
124 return -1;
125 }
126 if (!cnt)
127 break;
128 sb->len += cnt;
129 strbuf_grow(sb, 8192);
130 }
131
132 sb->buf[sb->len] = '\0';
133 return sb->len - oldlen;
134}