blob: 92e068517c1aa0a83dbc4e227ed0d544d0336b44 [file] [log] [blame]
Ingo Molnar07800602009-04-20 15:00:56 +02001#include "cache.h"
2
3int prefixcmp(const char *str, const char *prefix)
4{
5 for (; ; str++, prefix++)
6 if (!*prefix)
7 return 0;
8 else if (*str != *prefix)
9 return (unsigned char)*prefix - (unsigned char)*str;
10}
11
12/*
13 * Used as the default ->buf value, so that people can always assume
14 * buf is non NULL and ->buf is NUL terminated even for a freshly
15 * initialized strbuf.
16 */
17char strbuf_slopbuf[1];
18
Ingo Molnarf37a2912009-07-01 12:37:06 +020019void strbuf_init(struct strbuf *sb, ssize_t hint)
Ingo Molnar07800602009-04-20 15:00:56 +020020{
21 sb->alloc = sb->len = 0;
22 sb->buf = strbuf_slopbuf;
23 if (hint)
24 strbuf_grow(sb, hint);
25}
26
27void strbuf_release(struct strbuf *sb)
28{
29 if (sb->alloc) {
30 free(sb->buf);
31 strbuf_init(sb, 0);
32 }
33}
34
35char *strbuf_detach(struct strbuf *sb, size_t *sz)
36{
37 char *res = sb->alloc ? sb->buf : NULL;
38 if (sz)
39 *sz = sb->len;
40 strbuf_init(sb, 0);
41 return res;
42}
43
Ingo Molnar07800602009-04-20 15:00:56 +020044void strbuf_grow(struct strbuf *sb, size_t extra)
45{
46 if (sb->len + extra + 1 <= sb->len)
47 die("you want to use way too much memory");
48 if (!sb->alloc)
49 sb->buf = NULL;
50 ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
51}
52
Arnaldo Carvalho de Meloa41794c2010-05-18 18:29:23 -030053static void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
Ingo Molnar07800602009-04-20 15:00:56 +020054 const void *data, size_t dlen)
55{
56 if (pos + len < pos)
57 die("you want to use way too much memory");
58 if (pos > sb->len)
59 die("`pos' is too far after the end of the buffer");
60 if (pos + len > sb->len)
61 die("`pos + len' is too far after the end of the buffer");
62
63 if (dlen >= len)
64 strbuf_grow(sb, dlen - len);
65 memmove(sb->buf + pos + dlen,
66 sb->buf + pos + len,
67 sb->len - pos - len);
68 memcpy(sb->buf + pos, data, dlen);
69 strbuf_setlen(sb, sb->len + dlen - len);
70}
71
Ingo Molnar07800602009-04-20 15:00:56 +020072void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
73{
74 strbuf_splice(sb, pos, len, NULL, 0);
75}
76
77void strbuf_add(struct strbuf *sb, const void *data, size_t len)
78{
79 strbuf_grow(sb, len);
80 memcpy(sb->buf + sb->len, data, len);
81 strbuf_setlen(sb, sb->len + len);
82}
83
Ingo Molnar07800602009-04-20 15:00:56 +020084void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
85{
86 int len;
87 va_list ap;
88
89 if (!strbuf_avail(sb))
90 strbuf_grow(sb, 64);
91 va_start(ap, fmt);
92 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
93 va_end(ap);
94 if (len < 0)
95 die("your vsnprintf is broken");
96 if (len > strbuf_avail(sb)) {
97 strbuf_grow(sb, len);
98 va_start(ap, fmt);
99 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
100 va_end(ap);
101 if (len > strbuf_avail(sb)) {
102 die("this should not happen, your snprintf is broken");
103 }
104 }
105 strbuf_setlen(sb, sb->len + len);
106}
107
Ingo Molnarf37a2912009-07-01 12:37:06 +0200108ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
Ingo Molnar07800602009-04-20 15:00:56 +0200109{
110 size_t oldlen = sb->len;
111 size_t oldalloc = sb->alloc;
112
113 strbuf_grow(sb, hint ? hint : 8192);
114 for (;;) {
115 ssize_t cnt;
116
117 cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
118 if (cnt < 0) {
119 if (oldalloc == 0)
120 strbuf_release(sb);
121 else
122 strbuf_setlen(sb, oldlen);
123 return -1;
124 }
125 if (!cnt)
126 break;
127 sb->len += cnt;
128 strbuf_grow(sb, 8192);
129 }
130
131 sb->buf[sb->len] = '\0';
132 return sb->len - oldlen;
133}