index-pack: group the delta-base array entries also by type
Entries in the delta_base array are only grouped by the bytepattern in
the delta_base union, some of which have 20-byte object name of the base
object (i.e. base for REF_DELTA objects), while others have sizeof(off_t)
bytes followed by enough NULs to fill 20-byte. The loops to iterate
through a range inside this array still needs to inspect the type of the
delta, and skip over false hits.
Group the entries also by type to eliminate the potential of false hits.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 8dc5c0b..1b5d83a 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -391,7 +391,18 @@
return data;
}
-static int find_delta(const union delta_base *base)
+static int compare_delta_bases(const union delta_base *base1,
+ const union delta_base *base2,
+ enum object_type type1,
+ enum object_type type2)
+{
+ int cmp = type1 - type2;
+ if (cmp)
+ return cmp;
+ return memcmp(base1, base2, UNION_BASE_SZ);
+}
+
+static int find_delta(const union delta_base *base, enum object_type type)
{
int first = 0, last = nr_deltas;
@@ -400,7 +411,8 @@
struct delta_entry *delta = &deltas[next];
int cmp;
- cmp = memcmp(base, &delta->base, UNION_BASE_SZ);
+ cmp = compare_delta_bases(base, &delta->base,
+ type, objects[delta->obj_no].type);
if (!cmp)
return next;
if (cmp < 0) {
@@ -413,9 +425,10 @@
}
static void find_delta_children(const union delta_base *base,
- int *first_index, int *last_index)
+ int *first_index, int *last_index,
+ enum object_type type)
{
- int first = find_delta(base);
+ int first = find_delta(base, type);
int last = first;
int end = nr_deltas - 1;
@@ -543,11 +556,13 @@
union delta_base base_spec;
hashcpy(base_spec.sha1, base->obj->idx.sha1);
- find_delta_children(&base_spec, &ref_first, &ref_last);
+ find_delta_children(&base_spec,
+ &ref_first, &ref_last, OBJ_REF_DELTA);
memset(&base_spec, 0, sizeof(base_spec));
base_spec.offset = base->obj->idx.offset;
- find_delta_children(&base_spec, &ofs_first, &ofs_last);
+ find_delta_children(&base_spec,
+ &ofs_first, &ofs_last, OBJ_OFS_DELTA);
}
if (ref_last == -1 && ofs_last == -1) {
@@ -559,24 +574,24 @@
for (i = ref_first; i <= ref_last; i++) {
struct object_entry *child = objects + deltas[i].obj_no;
- if (child->real_type == OBJ_REF_DELTA) {
- struct base_data result;
- resolve_delta(child, base, &result);
- if (i == ref_last && ofs_last == -1)
- free_base_data(base);
- find_unresolved_deltas(&result, base);
- }
+ struct base_data result;
+
+ assert(child->real_type == OBJ_REF_DELTA);
+ resolve_delta(child, base, &result);
+ if (i == ref_last && ofs_last == -1)
+ free_base_data(base);
+ find_unresolved_deltas(&result, base);
}
for (i = ofs_first; i <= ofs_last; i++) {
struct object_entry *child = objects + deltas[i].obj_no;
- if (child->real_type == OBJ_OFS_DELTA) {
- struct base_data result;
- resolve_delta(child, base, &result);
- if (i == ofs_last)
- free_base_data(base);
- find_unresolved_deltas(&result, base);
- }
+ struct base_data result;
+
+ assert(child->real_type == OBJ_OFS_DELTA);
+ resolve_delta(child, base, &result);
+ if (i == ofs_last)
+ free_base_data(base);
+ find_unresolved_deltas(&result, base);
}
unlink_base_data(base);
@@ -586,7 +601,11 @@
{
const struct delta_entry *delta_a = a;
const struct delta_entry *delta_b = b;
- return memcmp(&delta_a->base, &delta_b->base, UNION_BASE_SZ);
+
+ /* group by type (ref vs ofs) and then by value (sha-1 or offset) */
+ return compare_delta_bases(&delta_a->base, &delta_b->base,
+ objects[delta_a->obj_no].type,
+ objects[delta_b->obj_no].type);
}
/* Parse all objects and return the pack content SHA1 hash */
