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