1 #include "cache.h"
2
prefixcmp(const char * str,const char * prefix)3 int 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 */
17 char strbuf_slopbuf[1];
18
strbuf_init(struct strbuf * sb,ssize_t hint)19 void strbuf_init(struct strbuf *sb, ssize_t hint)
20 {
21 sb->alloc = sb->len = 0;
22 sb->buf = strbuf_slopbuf;
23 if (hint)
24 strbuf_grow(sb, hint);
25 }
26
strbuf_release(struct strbuf * sb)27 void strbuf_release(struct strbuf *sb)
28 {
29 if (sb->alloc) {
30 free(sb->buf);
31 strbuf_init(sb, 0);
32 }
33 }
34
strbuf_detach(struct strbuf * sb,size_t * sz)35 char *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
strbuf_grow(struct strbuf * sb,size_t extra)44 void 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
strbuf_splice(struct strbuf * sb,size_t pos,size_t len,const void * data,size_t dlen)53 static void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
54 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
strbuf_remove(struct strbuf * sb,size_t pos,size_t len)72 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
73 {
74 strbuf_splice(sb, pos, len, NULL, 0);
75 }
76
strbuf_add(struct strbuf * sb,const void * data,size_t len)77 void 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
strbuf_addf(struct strbuf * sb,const char * fmt,...)84 void 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
strbuf_read(struct strbuf * sb,int fd,ssize_t hint)108 ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint)
109 {
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 }
134