+static struct sha1_size_cache {
+ unsigned char sha1[20];
+ unsigned long size;
+} **sha1_size_cache;
+static int sha1_size_cache_nr, sha1_size_cache_alloc;
+
+static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
+ unsigned long size)
+{
+ int first, last;
+ struct sha1_size_cache *e;
+
+ first = 0;
+ last = sha1_size_cache_nr;
+ while (last > first) {
+ int next = (last + first) >> 1;
+ e = sha1_size_cache[next];
+ int cmp = memcmp(e->sha1, sha1, 20);
+ if (!cmp)
+ return e;
+ if (cmp < 0) {
+ last = next;
+ continue;
+ }
+ first = next+1;
+ }
+ /* not found */
+ if (size == UINT_MAX)
+ return NULL;
+ /* insert to make it at "first" */
+ if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
+ sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
+ sha1_size_cache = xrealloc(sha1_size_cache,
+ sha1_size_cache_alloc *
+ sizeof(*sha1_size_cache));
+ }
+ sha1_size_cache_nr++;
+ if (first < sha1_size_cache_nr)
+ memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
+ (sha1_size_cache_nr - first - 1) *
+ sizeof(*sha1_size_cache));
+ e = xmalloc(sizeof(struct sha1_size_cache));
+ sha1_size_cache[first] = e;
+ memcpy(e->sha1, sha1, 20);
+ e->size = size;
+ return e;
+}
+