diff options
Diffstat (limited to 'diff.c')
| -rw-r--r-- | diff.c | 83 |
1 files changed, 81 insertions, 2 deletions
@@ -12,6 +12,7 @@ static const char *diff_opts = "-pu"; static unsigned char null_sha1[20] = { 0, }; static int reverse_diff; +static int use_size_cache; static const char *external_diff(void) { @@ -222,12 +223,60 @@ static int work_tree_matches(const char *name, const unsigned char *sha1) return 1; } +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; +} + /* * While doing rename detection and pickaxe operation, we may need to * grab the data for the blob (or file) for our own in-core comparison. * diff_filespec has data and size fields for this purpose. */ -int diff_populate_filespec(struct diff_filespec *s) +int diff_populate_filespec(struct diff_filespec *s, int size_only) { int err = 0; if (!DIFF_FILE_VALID(s)) @@ -235,6 +284,9 @@ int diff_populate_filespec(struct diff_filespec *s) if (S_ISDIR(s->mode)) return -1; + if (!use_size_cache) + size_only = 0; + if (s->data) return err; if (!s->sha1_valid || @@ -254,6 +306,8 @@ int diff_populate_filespec(struct diff_filespec *s) s->size = st.st_size; if (!s->size) goto empty; + if (size_only) + return 0; if (S_ISLNK(st.st_mode)) { int ret; s->data = xmalloc(s->size); @@ -273,9 +327,21 @@ int diff_populate_filespec(struct diff_filespec *s) close(fd); } else { + /* We cannot do size only for SHA1 blobs */ char type[20]; + struct sha1_size_cache *e; + + if (size_only) { + e = locate_size_cache(s->sha1, UINT_MAX); + if (e) { + s->size = e->size; + return 0; + } + } s->data = read_sha1_file(s->sha1, type, &s->size); s->should_free = 1; + if (s->data && size_only) + locate_size_cache(s->sha1, s->size); } return 0; } @@ -361,7 +427,7 @@ static void prepare_temp_file(const char *name, return; } else { - if (diff_populate_filespec(one)) + if (diff_populate_filespec(one, 0)) die("cannot read data blob for %s", one->path); prep_temp_blob(temp, one->data, one->size, one->sha1, one->mode); @@ -496,6 +562,19 @@ void diff_setup(int flags) { if (flags & DIFF_SETUP_REVERSE) reverse_diff = 1; + if (flags & DIFF_SETUP_USE_CACHE) { + if (!active_cache) + /* read-cache does not die even when it fails + * so it is safe for us to do this here. Also + * it does not smudge active_cache or active_nr + * when it fails, so we do not have to worry about + * cleaning it up oufselves either. + */ + read_cache(); + } + if (flags & DIFF_SETUP_USE_SIZE_CACHE) + use_size_cache = 1; + } struct diff_queue_struct diff_queued_diff; |