Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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}