strbuf change: be sure ->buf is never ever NULL.
[git/git.git] / strbuf.c
CommitLineData
812666c8 1#include "cache.h"
d1df5743 2
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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 */
8char strbuf_slopbuf[1];
9
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10void strbuf_init(struct strbuf *sb, size_t hint)
11{
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12 sb->alloc = sb->len = 0;
13 sb->buf = strbuf_slopbuf;
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14 if (hint)
15 strbuf_grow(sb, hint);
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16}
17
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18void strbuf_release(struct strbuf *sb)
19{
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20 if (sb->alloc) {
21 free(sb->buf);
22 strbuf_init(sb, 0);
23 }
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24}
25
b315c5c0 26char *strbuf_detach(struct strbuf *sb, size_t *sz)
917c9a71 27{
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28 char *res = sb->alloc ? sb->buf : NULL;
29 if (sz)
30 *sz = sb->len;
f1696ee3 31 strbuf_init(sb, 0);
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32 return res;
33}
34
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35void 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
45void strbuf_grow(struct strbuf *sb, size_t extra)
46{
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47 if (sb->len + extra + 1 <= sb->len)
48 die("you want to use way too much memory");
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49 if (!sb->alloc)
50 sb->buf = NULL;
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51 ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
52}
53
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54void 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
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61int 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
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73void 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
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92void 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
97void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
98{
99 strbuf_splice(sb, pos, len, NULL, 0);
100}
101
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102void strbuf_add(struct strbuf *sb, const void *data, size_t len)
103{
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104 strbuf_grow(sb, len);
105 memcpy(sb->buf + sb->len, data, len);
106 strbuf_setlen(sb, sb->len + len);
107}
108
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109void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
110{
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111 int len;
112 va_list ap;
113
114 va_start(ap, fmt);
115 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
116 va_end(ap);
117 if (len < 0) {
118 len = 0;
119 }
f1696ee3 120 if (len > strbuf_avail(sb)) {
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121 strbuf_grow(sb, len);
122 va_start(ap, fmt);
123 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
124 va_end(ap);
f1696ee3 125 if (len > strbuf_avail(sb)) {
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126 die("this should not happen, your snprintf is broken");
127 }
128 }
129 strbuf_setlen(sb, sb->len + len);
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130}
131
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132size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
133{
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134 size_t res;
135
136 strbuf_grow(sb, size);
137 res = fread(sb->buf + sb->len, 1, size, f);
138 if (res > 0) {
139 strbuf_setlen(sb, sb->len + res);
d1df5743 140 }
b449f4cf 141 return res;
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142}
143
f1696ee3 144ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
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145{
146 size_t oldlen = sb->len;
147
f1696ee3 148 strbuf_grow(sb, hint ? hint : 8192);
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149 for (;;) {
150 ssize_t cnt;
151
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152 cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
153 if (cnt < 0) {
154 strbuf_setlen(sb, oldlen);
155 return -1;
156 }
157 if (!cnt)
158 break;
159 sb->len += cnt;
f1696ee3 160 strbuf_grow(sb, 8192);
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161 }
162
163 sb->buf[sb->len] = '\0';
164 return sb->len - oldlen;
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165}
166
e6c019d0 167int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
917c9a71 168{
d1df5743 169 int ch;
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170
171 strbuf_grow(sb, 0);
172 if (feof(fp))
173 return EOF;
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174
175 strbuf_reset(sb);
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176 while ((ch = fgetc(fp)) != EOF) {
177 if (ch == term)
178 break;
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179 strbuf_grow(sb, 1);
180 sb->buf[sb->len++] = ch;
d1df5743 181 }
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182 if (ch == EOF && sb->len == 0)
183 return EOF;
b449f4cf 184
b449f4cf 185 sb->buf[sb->len] = '\0';
e6c019d0 186 return 0;
d1df5743 187}
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188
189int strbuf_read_file(struct strbuf *sb, const char *path)
190{
191 int fd, len;
192
193 fd = open(path, O_RDONLY);
194 if (fd < 0)
195 return -1;
196 len = strbuf_read(sb, fd, 0);
197 close(fd);
198 if (len < 0)
199 return -1;
200
201 return len;
202}