Handle broken vsnprintf implementations in strbuf
[git/git.git] / strbuf.c
1 #include "cache.h"
2
3 /*
4 * Used as the default ->buf value, so that people can always assume
5 * buf is non NULL and ->buf is NUL terminated even for a freshly
6 * initialized strbuf.
7 */
8 char strbuf_slopbuf[1];
9
10 void strbuf_init(struct strbuf *sb, size_t hint)
11 {
12 sb->alloc = sb->len = 0;
13 sb->buf = strbuf_slopbuf;
14 if (hint)
15 strbuf_grow(sb, hint);
16 }
17
18 void strbuf_release(struct strbuf *sb)
19 {
20 if (sb->alloc) {
21 free(sb->buf);
22 strbuf_init(sb, 0);
23 }
24 }
25
26 char *strbuf_detach(struct strbuf *sb, size_t *sz)
27 {
28 char *res = sb->alloc ? sb->buf : NULL;
29 if (sz)
30 *sz = sb->len;
31 strbuf_init(sb, 0);
32 return res;
33 }
34
35 void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
36 {
37 strbuf_release(sb);
38 sb->buf = buf;
39 sb->len = len;
40 sb->alloc = alloc;
41 strbuf_grow(sb, 0);
42 sb->buf[sb->len] = '\0';
43 }
44
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
54 void strbuf_rtrim(struct strbuf *sb)
55 {
56 while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
57 sb->len--;
58 sb->buf[sb->len] = '\0';
59 }
60
61 int strbuf_cmp(struct strbuf *a, struct strbuf *b)
62 {
63 int cmp;
64 if (a->len < b->len) {
65 cmp = memcmp(a->buf, b->buf, a->len);
66 return cmp ? cmp : -1;
67 } else {
68 cmp = memcmp(a->buf, b->buf, b->len);
69 return cmp ? cmp : a->len != b->len;
70 }
71 }
72
73 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
74 const void *data, size_t dlen)
75 {
76 if (pos + len < pos)
77 die("you want to use way too much memory");
78 if (pos > sb->len)
79 die("`pos' is too far after the end of the buffer");
80 if (pos + len > sb->len)
81 die("`pos + len' is too far after the end of the buffer");
82
83 if (dlen >= len)
84 strbuf_grow(sb, dlen - len);
85 memmove(sb->buf + pos + dlen,
86 sb->buf + pos + len,
87 sb->len - pos - len);
88 memcpy(sb->buf + pos, data, dlen);
89 strbuf_setlen(sb, sb->len + dlen - len);
90 }
91
92 void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
93 {
94 strbuf_splice(sb, pos, 0, data, len);
95 }
96
97 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
98 {
99 strbuf_splice(sb, pos, len, NULL, 0);
100 }
101
102 void strbuf_add(struct strbuf *sb, const void *data, size_t len)
103 {
104 strbuf_grow(sb, len);
105 memcpy(sb->buf + sb->len, data, len);
106 strbuf_setlen(sb, sb->len + len);
107 }
108
109 void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
110 {
111 int len;
112 va_list ap;
113
114 if (!strbuf_avail(sb))
115 strbuf_grow(sb, 64);
116 va_start(ap, fmt);
117 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
118 va_end(ap);
119 if (len < 0)
120 die("your vsnprintf is broken");
121 if (len > strbuf_avail(sb)) {
122 strbuf_grow(sb, len);
123 va_start(ap, fmt);
124 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
125 va_end(ap);
126 if (len > strbuf_avail(sb)) {
127 die("this should not happen, your snprintf is broken");
128 }
129 }
130 strbuf_setlen(sb, sb->len + len);
131 }
132
133 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
134 {
135 size_t res;
136
137 strbuf_grow(sb, size);
138 res = fread(sb->buf + sb->len, 1, size, f);
139 if (res > 0) {
140 strbuf_setlen(sb, sb->len + res);
141 }
142 return res;
143 }
144
145 ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
146 {
147 size_t oldlen = sb->len;
148
149 strbuf_grow(sb, hint ? hint : 8192);
150 for (;;) {
151 ssize_t cnt;
152
153 cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
154 if (cnt < 0) {
155 strbuf_setlen(sb, oldlen);
156 return -1;
157 }
158 if (!cnt)
159 break;
160 sb->len += cnt;
161 strbuf_grow(sb, 8192);
162 }
163
164 sb->buf[sb->len] = '\0';
165 return sb->len - oldlen;
166 }
167
168 int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
169 {
170 int ch;
171
172 strbuf_grow(sb, 0);
173 if (feof(fp))
174 return EOF;
175
176 strbuf_reset(sb);
177 while ((ch = fgetc(fp)) != EOF) {
178 if (ch == term)
179 break;
180 strbuf_grow(sb, 1);
181 sb->buf[sb->len++] = ch;
182 }
183 if (ch == EOF && sb->len == 0)
184 return EOF;
185
186 sb->buf[sb->len] = '\0';
187 return 0;
188 }
189
190 int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
191 {
192 int fd, len;
193
194 fd = open(path, O_RDONLY);
195 if (fd < 0)
196 return -1;
197 len = strbuf_read(sb, fd, hint);
198 close(fd);
199 if (len < 0)
200 return -1;
201
202 return len;
203 }