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authorNicolas Pitre <nico@cam.org>2008-10-17 19:57:57 (GMT)
committerJunio C Hamano <gitster@pobox.com>2008-10-18 13:17:32 (GMT)
commit9441b61dc5c3f1f984114ec8bd470dc20c55dfe0 (patch)
treee2f151e936faa408f2e03e777f7dac153866a2cb /index-pack.c
parent46dc1b0e332612aa32c139007fa33f4b429de9d1 (diff)
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index-pack: rationalize delta resolution code
Instead of having strange loops for walking unresolved deltas with the same base duplicated in many places, let's rework the code so this is done in a single place instead. This simplifies callers quite a bit too. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'index-pack.c')
-rw-r--r--index-pack.c123
1 files changed, 58 insertions, 65 deletions
diff --git a/index-pack.c b/index-pack.c
index d3a4d31..82843e7 100644
--- a/index-pack.c
+++ b/index-pack.c
@@ -244,7 +244,8 @@ static void link_base_data(struct base_data *base, struct base_data *c)
c->base = base;
c->child = NULL;
- base_cache_used += c->size;
+ if (c->data)
+ base_cache_used += c->size;
prune_base_data(c);
}
@@ -494,8 +495,10 @@ static void *get_base_data(struct base_data *c)
free(raw);
if (!c->data)
bad_object(obj->idx.offset, "failed to apply delta");
- } else
+ } else {
c->data = get_data_from_pack(obj);
+ c->size = obj->size;
+ }
base_cache_used += c->size;
prune_base_data(c);
@@ -504,49 +507,73 @@ static void *get_base_data(struct base_data *c)
}
static void resolve_delta(struct object_entry *delta_obj,
- struct base_data *base_obj, enum object_type type)
+ struct base_data *base, struct base_data *result)
{
void *delta_data;
unsigned long delta_size;
- union delta_base delta_base;
- int j, first, last;
- struct base_data result;
- delta_obj->real_type = type;
+ delta_obj->real_type = base->obj->type;
delta_data = get_data_from_pack(delta_obj);
delta_size = delta_obj->size;
- result.data = patch_delta(get_base_data(base_obj), base_obj->size,
- delta_data, delta_size,
- &result.size);
+ result->obj = delta_obj;
+ result->data = patch_delta(get_base_data(base), base->obj->size,
+ delta_data, delta_size, &result->size);
free(delta_data);
- if (!result.data)
+ if (!result->data)
bad_object(delta_obj->idx.offset, "failed to apply delta");
- sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
+ sha1_object(result->data, result->size, delta_obj->real_type,
+ delta_obj->idx.sha1);
nr_resolved_deltas++;
+}
+
+static void find_unresolved_deltas(struct base_data *base,
+ struct base_data *prev_base)
+{
+ int i, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
+
+ /*
+ * This is a recursive function. Those brackets should help reducing
+ * stack usage by limiting the scope of the delta_base union.
+ */
+ {
+ union delta_base base_spec;
+
+ hashcpy(base_spec.sha1, base->obj->idx.sha1);
+ ref = !find_delta_children(&base_spec, &ref_first, &ref_last);
+
+ memset(&base_spec, 0, sizeof(base_spec));
+ base_spec.offset = base->obj->idx.offset;
+ ofs = !find_delta_children(&base_spec, &ofs_first, &ofs_last);
+ }
+
+ if (!ref && !ofs)
+ return;
- result.obj = delta_obj;
- link_base_data(base_obj, &result);
+ link_base_data(prev_base, base);
- hashcpy(delta_base.sha1, delta_obj->idx.sha1);
- if (!find_delta_children(&delta_base, &first, &last)) {
- for (j = first; j <= last; j++) {
- struct object_entry *child = objects + deltas[j].obj_no;
- if (child->real_type == OBJ_REF_DELTA)
- resolve_delta(child, &result, type);
+ if (ref) {
+ 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);
+ find_unresolved_deltas(&result, base);
+ }
}
}
- memset(&delta_base, 0, sizeof(delta_base));
- delta_base.offset = delta_obj->idx.offset;
- if (!find_delta_children(&delta_base, &first, &last)) {
- for (j = first; j <= last; j++) {
- struct object_entry *child = objects + deltas[j].obj_no;
- if (child->real_type == OBJ_OFS_DELTA)
- resolve_delta(child, &result, type);
+ if (ofs) {
+ 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);
+ find_unresolved_deltas(&result, base);
+ }
}
}
- unlink_base_data(&result);
+ unlink_base_data(base);
}
static int compare_delta_entry(const void *a, const void *b)
@@ -622,37 +649,13 @@ static void parse_pack_objects(unsigned char *sha1)
progress = start_progress("Resolving deltas", nr_deltas);
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
- union delta_base base;
- int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
struct base_data base_obj;
if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
continue;
- hashcpy(base.sha1, obj->idx.sha1);
- ref = !find_delta_children(&base, &ref_first, &ref_last);
- memset(&base, 0, sizeof(base));
- base.offset = obj->idx.offset;
- ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
- if (!ref && !ofs)
- continue;
- base_obj.data = get_data_from_pack(obj);
- base_obj.size = obj->size;
base_obj.obj = obj;
- link_base_data(NULL, &base_obj);
-
- if (ref)
- for (j = ref_first; j <= ref_last; j++) {
- struct object_entry *child = objects + deltas[j].obj_no;
- if (child->real_type == OBJ_REF_DELTA)
- resolve_delta(child, &base_obj, obj->type);
- }
- if (ofs)
- for (j = ofs_first; j <= ofs_last; j++) {
- struct object_entry *child = objects + deltas[j].obj_no;
- if (child->real_type == OBJ_OFS_DELTA)
- resolve_delta(child, &base_obj, obj->type);
- }
- unlink_base_data(&base_obj);
+ base_obj.data = NULL;
+ find_unresolved_deltas(&base_obj, NULL);
display_progress(progress, nr_resolved_deltas);
}
}
@@ -745,7 +748,6 @@ static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
for (i = 0; i < n; i++) {
struct delta_entry *d = sorted_by_pos[i];
enum object_type type;
- int j, first, last;
struct base_data base_obj;
if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
@@ -759,16 +761,7 @@ static void fix_unresolved_deltas(struct sha1file *f, int nr_unresolved)
die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
base_obj.obj = append_obj_to_pack(f, d->base.sha1,
base_obj.data, base_obj.size, type);
- link_base_data(NULL, &base_obj);
-
- find_delta_children(&d->base, &first, &last);
- for (j = first; j <= last; j++) {
- struct object_entry *child = objects + deltas[j].obj_no;
- if (child->real_type == OBJ_REF_DELTA)
- resolve_delta(child, &base_obj, type);
- }
-
- unlink_base_data(&base_obj);
+ find_unresolved_deltas(&base_obj, NULL);
display_progress(progress, nr_resolved_deltas);
}
free(sorted_by_pos);