compat/strbuf.c

   1 /*
   2  * From git 1.7.3.1
   3  * License: GPL-2
   4  *
   5  * Modifications (2010-10-19):
   6  *  - add license header.
   7  *  - use compat-util.h in place of cache.h.
   8  *  - include strbuf.h directly instead of through refs.h.
   9  *  - remove unneeded functions.
  10  * Modifications (2012-05-18):
  11  *  - restore functions needed for downstream changes.
  12  */
  13
  14 #include "compat-util.h"
  15 #include "strbuf.h"
  16
  17 /*
  18  * Used as the default ->buf value, so that people can always assume
  19  * buf is non NULL and ->buf is NUL terminated even for a freshly
  20  * initialized strbuf.
  21  */
  22 char strbuf_slopbuf[1];
  23
  24 void strbuf_init(struct strbuf *sb, size_t hint)
  25 {
  26         sb->alloc = sb->len = 0;
  27         sb->buf = strbuf_slopbuf;
  28         if (hint)
  29                 strbuf_grow(sb, hint);
  30 }
  31
  32 void strbuf_release(struct strbuf *sb)
  33 {
  34         if (sb->alloc) {
  35                 free(sb->buf);
  36                 strbuf_init(sb, 0);
  37         }
  38 }
  39
  40 void strbuf_grow(struct strbuf *sb, size_t extra)
  41 {
  42         if (sb->len + extra + 1 <= sb->len)
  43                 die("you want to use way too much memory");
  44         if (!sb->alloc)
  45                 sb->buf = NULL;
  46         ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
  47 }
  48
  49 void strbuf_add(struct strbuf *sb, const void *data, size_t len)
  50 {
  51         strbuf_grow(sb, len);
  52         memcpy(sb->buf + sb->len, data, len);
  53         strbuf_setlen(sb, sb->len + len);
  54 }
  55
  56 size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
  57 {
  58         size_t res;
  59         size_t oldalloc = sb->alloc;
  60
  61         strbuf_grow(sb, size);
  62         res = fread(sb->buf + sb->len, 1, size, f);
  63         if (res > 0)
  64                 strbuf_setlen(sb, sb->len + res);
  65         else if (oldalloc == 0)
  66                 strbuf_release(sb);
  67         return res;
  68 }
  69
  70 void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
  71                                    const void *data, size_t dlen)
  72 {
  73         if (unsigned_add_overflows(pos, len))
  74                 die("you want to use way too much memory");
  75         if (pos > sb->len)
  76                 die("`pos' is too far after the end of the buffer");
  77         if (pos + len > sb->len)
  78                 die("`pos + len' is too far after the end of the buffer");
  79
  80         if (dlen >= len)
  81                 strbuf_grow(sb, dlen - len);
  82         memmove(sb->buf + pos + dlen,
  83                         sb->buf + pos + len,
  84                         sb->len - pos - len);
  85         memcpy(sb->buf + pos, data, dlen);
  86         strbuf_setlen(sb, sb->len + dlen - len);
  87 }
  88
  89 void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
  90 {
  91         strbuf_splice(sb, pos, 0, data, len);
  92 }
  93
  94 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
  95 {
  96         strbuf_splice(sb, pos, len, NULL, 0);
  97 }