[PATCH 1/4] index-pack: Refactor base arguments of resolve_delta into a struct
We need to discard base objects which are not recently used if our memory gets low, such as when we are unpacking a long delta chain of a very large object.
To support tracking the available base objects we combine the pointer and size into a struct. Future changes would allow the data pointer to be free'd and marked NULL if memory gets low.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
---
index-pack.c | 60 +++++++++++++++++++++++++++++++--------------------------
1 files changed, 33 insertions(+), 27 deletions(-)
diff --git a/index-pack.c b/index-pack.c
index 25db5db..db03478 100644
--- a/index-pack.c
+++ b/index-pack.c
@@ -26,6 +26,11 @@ union delta_base {
off_t offset;
};
+struct base_data {
+ void *data;
+ unsigned long size;
+};
+
/*
* Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
* to memcmp() only the first 20 bytes.
@@ -426,25 +431,25 @@ static void sha1_object(const void *data, unsigned long size,
}
}
-static void resolve_delta(struct object_entry *delta_obj, void *base_data,
- unsigned long base_size, enum object_type type)
+static void resolve_delta(struct object_entry *delta_obj,
+ struct base_data *base_obj, enum object_type type)
{
void *delta_data;
unsigned long delta_size;
- void *result;
- unsigned long result_size;
union delta_base delta_base;
int j, first, last;
+ struct base_data result;
delta_obj->real_type = type;
delta_data = get_data_from_pack(delta_obj);
delta_size = delta_obj->size;
- result = patch_delta(base_data, base_size, delta_data, delta_size,
- &result_size);
+ result.data = patch_delta(base_obj->data, base_obj->size,
+ delta_data, delta_size,
+ &result.size);
free(delta_data);
- if (!result)
+ if (!result.data)
bad_object(delta_obj->idx.offset, "failed to apply delta");
- sha1_object(result, result_size, type, delta_obj->idx.sha1);
+ sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
nr_resolved_deltas++;
hashcpy(delta_base.sha1, delta_obj->idx.sha1);
@@ -452,7 +457,7 @@ static void resolve_delta(struct object_entry *delta_obj, void *base_data,
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, result_size, type);
+ resolve_delta(child, &result, type);
}
}
@@ -462,11 +467,11 @@ static void resolve_delta(struct object_entry *delta_obj, void *base_data,
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, result_size, type);
+ resolve_delta(child, &result, type);
}
}
- free(result);
+ free(result.data);
}
static int compare_delta_entry(const void *a, const void *b)
@@ -481,7 +486,6 @@ static void parse_pack_objects(unsigned char *sha1)
{
int i;
struct delta_entry *delta = deltas;
- void *data;
struct stat st;
/*
@@ -496,7 +500,7 @@ static void parse_pack_objects(unsigned char *sha1)
nr_objects);
for (i = 0; i < nr_objects; i++) {
struct object_entry *obj = &objects[i];
- data = unpack_raw_entry(obj, &delta->base);
+ void *data = unpack_raw_entry(obj, &delta->base);
obj->real_type = obj->type;
if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
nr_deltas++;
@@ -545,6 +549,7 @@ static void parse_pack_objects(unsigned char *sha1)
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;
@@ -555,22 +560,22 @@ static void parse_pack_objects(unsigned char *sha1)
ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
if (!ref && !ofs)
continue;
- data = get_data_from_pack(obj);
+ base_obj.data = get_data_from_pack(obj);
+ base_obj.size = obj->size;
+
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, data,
- obj->size, obj->type);
+ 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, data,
- obj->size, obj->type);
+ resolve_delta(child, &base_obj, obj->type);
}
- free(data);
+ free(base_obj.data);
display_progress(progress, nr_resolved_deltas);
}
}
@@ -656,28 +661,29 @@ static void fix_unresolved_deltas(int nr_unresolved)
for (i = 0; i < n; i++) {
struct delta_entry *d = sorted_by_pos[i];
- void *data;
- unsigned long size;
enum object_type type;
int j, first, last;
+ struct base_data base_obj;
if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
continue;
- data = read_sha1_file(d->base.sha1, &type, &size);
- if (!data)
+ base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
+ if (!base_obj.data)
continue;
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, data, size, type);
+ resolve_delta(child, &base_obj, type);
}
- if (check_sha1_signature(d->base.sha1, data, size, typename(type)))
+ if (check_sha1_signature(d->base.sha1, base_obj.data,
+ base_obj.size, typename(type)))
die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
- append_obj_to_pack(d->base.sha1, data, size, type);
- free(data);
+ append_obj_to_pack(d->base.sha1, base_obj.data,
+ base_obj.size, type);
+ free(base_obj.data);
display_progress(progress, nr_resolved_deltas);
}
free(sorted_by_pos);
--
1.5.6.2.393.g45096
