1 #include "cache.h"
2 #include <linux/kernel.h>
3
prefixcmp(const char * str,const char * prefix)4 int 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 */
18 char strbuf_slopbuf[1];
19
strbuf_init(struct strbuf * sb,ssize_t hint)20 void 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
strbuf_release(struct strbuf * sb)28 void strbuf_release(struct strbuf *sb)
29 {
30 if (sb->alloc) {
31 zfree(&sb->buf);
32 strbuf_init(sb, 0);
33 }
34 }
35
strbuf_detach(struct strbuf * sb,size_t * sz)36 char *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
strbuf_grow(struct strbuf * sb,size_t extra)45 void 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
strbuf_splice(struct strbuf * sb,size_t pos,size_t len,const void * data,size_t dlen)54 static 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
strbuf_remove(struct strbuf * sb,size_t pos,size_t len)73 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
74 {
75 strbuf_splice(sb, pos, len, NULL, 0);
76 }
77
strbuf_add(struct strbuf * sb,const void * data,size_t len)78 void 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
strbuf_addf(struct strbuf * sb,const char * fmt,...)85 void 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
strbuf_read(struct strbuf * sb,int fd,ssize_t hint)109 ssize_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 }
135