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> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Shawn O. Pearce committed
Jul 13, 2008 at 22:07 UTC
f41aebd46998c8b6df3733196d55aeb7162b3df6
1 file changed
+33
-27
index-pack.c
+33
-27
@@ -26,6 +26,11 @@ union delta_base {
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off_t offset;
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};
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+struct base_data {
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+ void *data;
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+ unsigned long size;
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+};
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+
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/*
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* Even if sizeof(union delta_base) == 24 on 64-bit archs, we really want
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* to memcmp() only the first 20 bytes.
@@ -425,25 +430,25 @@ static void sha1_object(const void *data, unsigned long size,
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}
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}
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-static void resolve_delta(struct object_entry *delta_obj, void *base_data,
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- unsigned long base_size, enum object_type type)
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+static void resolve_delta(struct object_entry *delta_obj,
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+ struct base_data *base_obj, enum object_type type)
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{
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void *delta_data;
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unsigned long delta_size;
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- void *result;
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- unsigned long result_size;
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union delta_base delta_base;
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int j, first, last;
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+ struct base_data result;
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delta_obj->real_type = type;
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delta_data = get_data_from_pack(delta_obj);
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delta_size = delta_obj->size;
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- result = patch_delta(base_data, base_size, delta_data, delta_size,
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- &result_size);
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+ result.data = patch_delta(base_obj->data, base_obj->size,
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+ delta_data, delta_size,
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+ &result.size);
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free(delta_data);
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- if (!result)
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+ if (!result.data)
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bad_object(delta_obj->idx.offset, "failed to apply delta");
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- sha1_object(result, result_size, type, delta_obj->idx.sha1);
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+ sha1_object(result.data, result.size, type, delta_obj->idx.sha1);
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nr_resolved_deltas++;
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hashcpy(delta_base.sha1, delta_obj->idx.sha1);
@@ -451,7 +456,7 @@ static void resolve_delta(struct object_entry *delta_obj, void *base_data,
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for (j = first; j <= last; j++) {
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struct object_entry *child = objects + deltas[j].obj_no;
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if (child->real_type == OBJ_REF_DELTA)
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- resolve_delta(child, result, result_size, type);
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+ resolve_delta(child, &result, type);
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}
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}
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@@ -461,11 +466,11 @@ static void resolve_delta(struct object_entry *delta_obj, void *base_data,
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for (j = first; j <= last; j++) {
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struct object_entry *child = objects + deltas[j].obj_no;
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if (child->real_type == OBJ_OFS_DELTA)
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- resolve_delta(child, result, result_size, type);
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+ resolve_delta(child, &result, type);
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}
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}
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- free(result);
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+ free(result.data);
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}
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static int compare_delta_entry(const void *a, const void *b)
@@ -480,7 +485,6 @@ static void parse_pack_objects(unsigned char *sha1)
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{
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int i;
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struct delta_entry *delta = deltas;
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- void *data;
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struct stat st;
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/*
@@ -495,7 +499,7 @@ static void parse_pack_objects(unsigned char *sha1)
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nr_objects);
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for (i = 0; i < nr_objects; i++) {
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struct object_entry *obj = &objects[i];
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- data = unpack_raw_entry(obj, &delta->base);
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+ void *data = unpack_raw_entry(obj, &delta->base);
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obj->real_type = obj->type;
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if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
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nr_deltas++;
@@ -544,6 +548,7 @@ static void parse_pack_objects(unsigned char *sha1)
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struct object_entry *obj = &objects[i];
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union delta_base base;
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int j, ref, ref_first, ref_last, ofs, ofs_first, ofs_last;
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+ struct base_data base_obj;
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if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
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continue;
@@ -554,22 +559,22 @@ static void parse_pack_objects(unsigned char *sha1)
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ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
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if (!ref && !ofs)
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continue;
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- data = get_data_from_pack(obj);
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+ base_obj.data = get_data_from_pack(obj);
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+ base_obj.size = obj->size;
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+
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if (ref)
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for (j = ref_first; j <= ref_last; j++) {
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struct object_entry *child = objects + deltas[j].obj_no;
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if (child->real_type == OBJ_REF_DELTA)
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- resolve_delta(child, data,
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- obj->size, obj->type);
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+ resolve_delta(child, &base_obj, obj->type);
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}
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if (ofs)
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for (j = ofs_first; j <= ofs_last; j++) {
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struct object_entry *child = objects + deltas[j].obj_no;
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if (child->real_type == OBJ_OFS_DELTA)
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- resolve_delta(child, data,
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- obj->size, obj->type);
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+ resolve_delta(child, &base_obj, obj->type);
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}
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- free(data);
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+ free(base_obj.data);
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display_progress(progress, nr_resolved_deltas);
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}
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}
@@ -655,28 +660,29 @@ static void fix_unresolved_deltas(int nr_unresolved)
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for (i = 0; i < n; i++) {
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struct delta_entry *d = sorted_by_pos[i];
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- void *data;
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- unsigned long size;
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enum object_type type;
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int j, first, last;
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+ struct base_data base_obj;
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if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
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continue;
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- data = read_sha1_file(d->base.sha1, &type, &size);
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- if (!data)
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+ base_obj.data = read_sha1_file(d->base.sha1, &type, &base_obj.size);
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+ if (!base_obj.data)
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continue;
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find_delta_children(&d->base, &first, &last);
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for (j = first; j <= last; j++) {
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struct object_entry *child = objects + deltas[j].obj_no;
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if (child->real_type == OBJ_REF_DELTA)
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- resolve_delta(child, data, size, type);
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+ resolve_delta(child, &base_obj, type);
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}
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- if (check_sha1_signature(d->base.sha1, data, size, typename(type)))
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+ if (check_sha1_signature(d->base.sha1, base_obj.data,
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+ base_obj.size, typename(type)))
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die("local object %s is corrupt", sha1_to_hex(d->base.sha1));
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- append_obj_to_pack(d->base.sha1, data, size, type);
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- free(data);
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+ append_obj_to_pack(d->base.sha1, base_obj.data,
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+ base_obj.size, type);
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+ free(base_obj.data);
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display_progress(progress, nr_resolved_deltas);
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}
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free(sorted_by_pos);