strbuf.c

   1 #include "cache.h"
   2
   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
  19 void strbuf_init(struct strbuf *sb, size_t hint)
  20 {
  21         sb->alloc = sb->len = 0;
  22         sb->buf = strbuf_slopbuf;
  23         if (hint)
  24                 strbuf_grow(sb, hint);
  25 }
  26
  27 void strbuf_release(struct strbuf *sb)
  28 {
  29         if (sb->alloc) {
  30                 free(sb->buf);
  31                 strbuf_init(sb, 0);
  32         }
  33 }
  34
  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
  44 void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
  45 {
  46         strbuf_release(sb);
  47         sb->buf   = buf;
  48         sb->len   = len;
  49         sb->alloc = alloc;
  50         strbuf_grow(sb, 0);
  51         sb->buf[sb->len] = '\0';
  52 }
  53
  54 void strbuf_grow(struct strbuf *sb, size_t extra)
  55 {
  56         if (sb->len + extra + 1 <= sb->len)
  57                 die("you want to use way too much memory");
  58         if (!sb->alloc)
  59                 sb->buf = NULL;
  60         ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
  61 }
  62
  63 void strbuf_rtrim(struct strbuf *sb)
  64 {
  65         while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
  66                 sb->len--;
  67         sb->buf[sb->len] = '\0';
  68 }
  69
  70 int strbuf_cmp(struct strbuf *a, struct strbuf *b)
  71 {
  72         int cmp;
  73         if (a->len < b->len) {
  74                 cmp = memcmp(a->buf, b->buf, a->len);
  75                 return cmp ? cmp : -1;
  76         } else {
  77                 cmp = memcmp(a->buf, b->buf, b->len);
  78                 return cmp ? cmp : a->len != b->len;
  79         }
  80 }
  81
  82 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
  83                                    const void *data, size_t dlen)
  84 {
  85         if (pos + len < pos)
  86                 die("you want to use way too much memory");
  87         if (pos > sb->len)
  88                 die("`pos' is too far after the end of the buffer");
  89         if (pos + len > sb->len)
  90                 die("`pos + len' is too far after the end of the buffer");
  91
  92         if (dlen >= len)
  93                 strbuf_grow(sb, dlen - len);
  94         memmove(sb->buf + pos + dlen,
  95                         sb->buf + pos + len,
  96                         sb->len - pos - len);
  97         memcpy(sb->buf + pos, data, dlen);
  98         strbuf_setlen(sb, sb->len + dlen - len);
  99 }
 100
 101 void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
 102 {
 103         strbuf_splice(sb, pos, 0, data, len);
 104 }
 105
 106 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
 107 {
 108         strbuf_splice(sb, pos, len, NULL, 0);
 109 }
 110
 111 void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 112 {
 113         strbuf_grow(sb, len);
 114         memcpy(sb->buf + sb->len, data, len);
 115         strbuf_setlen(sb, sb->len + len);
 116 }
 117
 118 void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len)
 119 {
 120         strbuf_grow(sb, len);
 121         memcpy(sb->buf + sb->len, sb->buf + pos, len);
 122         strbuf_setlen(sb, sb->len + len);
 123 }
 124
 125 void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 126 {
 127         int len;
 128         va_list ap;
 129
 130         if (!strbuf_avail(sb))
 131                 strbuf_grow(sb, 64);
 132         va_start(ap, fmt);
 133         len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 134         va_end(ap);
 135         if (len < 0)
 136                 die("your vsnprintf is broken");
 137         if (len > strbuf_avail(sb)) {
 138                 strbuf_grow(sb, len);
 139                 va_start(ap, fmt);
 140                 len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 141                 va_end(ap);
 142                 if (len > strbuf_avail(sb)) {
 143                         die("this should not happen, your snprintf is broken");
 144                 }
 145         }
 146         strbuf_setlen(sb, sb->len + len);
 147 }
 148
 149 void strbuf_expand(struct strbuf *sb, const char *format,
 150                    const char **placeholders, expand_fn_t fn, void *context)
 151 {
 152         for (;;) {
 153                 const char *percent, **p;
 154
 155                 percent = strchrnul(format, '%');
 156                 strbuf_add(sb, format, percent - format);
 157                 if (!*percent)
 158                         break;
 159                 format = percent + 1;
 160
 161                 for (p = placeholders; *p; p++) {
 162                         if (!prefixcmp(format, *p))
 163                                 break;
 164                 }
 165                 if (*p) {
 166                         fn(sb, *p, context);
 167                         format += strlen(*p);
 168                 } else
 169                         strbuf_addch(sb, '%');
 170         }
 171 }
 172
 173 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 174 {
 175         size_t res;
 176
 177         strbuf_grow(sb, size);
 178         res = fread(sb->buf + sb->len, 1, size, f);
 179         if (res > 0) {
 180                 strbuf_setlen(sb, sb->len + res);
 181         }
 182         return res;
 183 }
 184
 185 ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 186 {
 187         size_t oldlen = sb->len;
 188
 189         strbuf_grow(sb, hint ? hint : 8192);
 190         for (;;) {
 191                 ssize_t cnt;
 192
 193                 cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
 194                 if (cnt < 0) {
 195                         strbuf_setlen(sb, oldlen);
 196                         return -1;
 197                 }
 198                 if (!cnt)
 199                         break;
 200                 sb->len += cnt;
 201                 strbuf_grow(sb, 8192);
 202         }
 203
 204         sb->buf[sb->len] = '\0';
 205         return sb->len - oldlen;
 206 }
 207
 208 int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
 209 {
 210         int ch;
 211
 212         strbuf_grow(sb, 0);
 213         if (feof(fp))
 214                 return EOF;
 215
 216         strbuf_reset(sb);
 217         while ((ch = fgetc(fp)) != EOF) {
 218                 if (ch == term)
 219                         break;
 220                 strbuf_grow(sb, 1);
 221                 sb->buf[sb->len++] = ch;
 222         }
 223         if (ch == EOF && sb->len == 0)
 224                 return EOF;
 225
 226         sb->buf[sb->len] = '\0';
 227         return 0;
 228 }
 229
 230 int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 231 {
 232         int fd, len;
 233
 234         fd = open(path, O_RDONLY);
 235         if (fd < 0)
 236                 return -1;
 237         len = strbuf_read(sb, fd, hint);
 238         close(fd);
 239         if (len < 0)
 240                 return -1;
 241
 242         return len;
 243 }