mirror of
https://github.com/git/git.git
synced 2024-06-05 19:06:10 +02:00
make index-pack able to complete thin packs.
A new flag, --fix-thin, instructs git-index-pack to append any missing objects to a thin pack to make it self contained and indexable. Of course objects missing from the pack must be present elsewhere in the local repository. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
This commit is contained in:
Nicolas Pitre
Junio C Hamano
parent
e42797f5b6
commit
636171cb80
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@ -8,7 +8,8 @@ git-index-pack - Build pack index file for an existing packed archive
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SYNOPSIS
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--------
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'git-index-pack' [-o <index-file>] { <pack-file> | --stdin [<pack-file>] }
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'git-index-pack' [-o <index-file>] <pack-file>
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'git-index-pack' --stdin [--fix-thin] [-o <index-file>] [<pack-file>]
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DESCRIPTION
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@ -36,6 +37,17 @@ OPTIONS
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objects/pack/ directory of the current git repository with
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a default name determined from the pack content.
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--fix-thin::
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It is possible for gitlink:git-pack-objects[1] to build
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"thin" pack, which records objects in deltified form based on
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objects not included in the pack to reduce network traffic.
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Those objects are expected to be present on the receiving end
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and they must be included in the pack for that pack to be self
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contained and indexable. Without this option any attempt to
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index a thin pack will fail. This option only makes sense in
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conjonction with --stdin.
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Author
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------
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Written by Sergey Vlasov <vsu@altlinux.ru>
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256
index-pack.c
256
index-pack.c
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@ -8,7 +8,7 @@
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#include "tree.h"
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static const char index_pack_usage[] =
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"git-index-pack [-o <index-file>] { <pack-file> | --stdin [<pack-file>] }";
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"git-index-pack [-o <index-file>] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
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struct object_entry
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{
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@ -33,14 +33,15 @@ union delta_base {
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struct delta_entry
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{
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struct object_entry *obj;
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union delta_base base;
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int obj_no;
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};
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static struct object_entry *objects;
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static struct delta_entry *deltas;
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static int nr_objects;
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static int nr_deltas;
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static int nr_resolved_deltas;
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static int from_stdin;
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@ -50,6 +51,18 @@ static unsigned long input_offset, input_len, consumed_bytes;
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static SHA_CTX input_ctx;
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static int input_fd, output_fd, mmap_fd;
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/* Discard current buffer used content. */
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static void flush()
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{
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if (input_offset) {
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if (output_fd >= 0)
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write_or_die(output_fd, input_buffer, input_offset);
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SHA1_Update(&input_ctx, input_buffer, input_offset);
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memcpy(input_buffer, input_buffer + input_offset, input_len);
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input_offset = 0;
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}
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}
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/*
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* Make sure at least "min" bytes are available in the buffer, and
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* return the pointer to the buffer.
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@ -60,13 +73,7 @@ static void * fill(int min)
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return input_buffer + input_offset;
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if (min > sizeof(input_buffer))
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die("cannot fill %d bytes", min);
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if (input_offset) {
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if (output_fd >= 0)
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write_or_die(output_fd, input_buffer, input_offset);
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SHA1_Update(&input_ctx, input_buffer, input_offset);
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memcpy(input_buffer, input_buffer + input_offset, input_len);
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input_offset = 0;
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}
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flush();
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do {
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int ret = xread(input_fd, input_buffer + input_len,
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sizeof(input_buffer) - input_len);
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@ -323,10 +330,9 @@ static void sha1_object(const void *data, unsigned long size,
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SHA1_Final(sha1, &ctx);
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}
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static void resolve_delta(struct delta_entry *delta, void *base_data,
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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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{
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struct object_entry *obj = delta->obj;
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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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@ -334,29 +340,34 @@ static void resolve_delta(struct delta_entry *delta, void *base_data,
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union delta_base delta_base;
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int j, first, last;
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obj->real_type = type;
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delta_data = get_data_from_pack(obj);
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delta_size = obj->size;
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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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free(delta_data);
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if (!result)
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bad_object(obj->offset, "failed to apply delta");
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sha1_object(result, result_size, type, obj->sha1);
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bad_object(delta_obj->offset, "failed to apply delta");
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sha1_object(result, result_size, type, delta_obj->sha1);
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nr_resolved_deltas++;
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hashcpy(delta_base.sha1, obj->sha1);
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hashcpy(delta_base.sha1, delta_obj->sha1);
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if (!find_delta_childs(&delta_base, &first, &last)) {
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for (j = first; j <= last; j++)
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if (deltas[j].obj->type == OBJ_REF_DELTA)
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resolve_delta(&deltas[j], result, result_size, type);
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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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}
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}
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memset(&delta_base, 0, sizeof(delta_base));
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delta_base.offset = obj->offset;
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delta_base.offset = delta_obj->offset;
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if (!find_delta_childs(&delta_base, &first, &last)) {
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for (j = first; j <= last; j++)
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if (deltas[j].obj->type == OBJ_OFS_DELTA)
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resolve_delta(&deltas[j], result, result_size, type);
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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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}
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}
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free(result);
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@ -389,7 +400,7 @@ static void parse_pack_objects(unsigned char *sha1)
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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++;
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delta->obj = obj;
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delta->obj_no = i;
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delta++;
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} else
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sha1_object(data, obj->size, obj->type, obj->sha1);
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@ -398,18 +409,15 @@ static void parse_pack_objects(unsigned char *sha1)
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objects[i].offset = consumed_bytes;
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/* Check pack integrity */
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SHA1_Update(&input_ctx, input_buffer, input_offset);
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flush();
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SHA1_Final(sha1, &input_ctx);
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if (hashcmp(fill(20), sha1))
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die("pack is corrupted (SHA1 mismatch)");
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use(20);
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if (output_fd >= 0)
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write_or_die(output_fd, input_buffer, input_offset);
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/* If input_fd is a file, we should have reached its end now. */
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if (fstat(input_fd, &st))
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die("cannot fstat packfile: %s", strerror(errno));
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if (S_ISREG(st.st_mode) && st.st_size != consumed_bytes)
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if (S_ISREG(st.st_mode) && st.st_size != consumed_bytes + 20)
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die("pack has junk at the end");
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/* Sort deltas by base SHA1/offset for fast searching */
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@ -440,24 +448,161 @@ static void parse_pack_objects(unsigned char *sha1)
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continue;
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data = get_data_from_pack(obj);
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if (ref)
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for (j = ref_first; j <= ref_last; j++)
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if (deltas[j].obj->type == OBJ_REF_DELTA)
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resolve_delta(&deltas[j], data,
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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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}
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if (ofs)
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for (j = ofs_first; j <= ofs_last; j++)
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if (deltas[j].obj->type == OBJ_OFS_DELTA)
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resolve_delta(&deltas[j], data,
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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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}
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free(data);
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}
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}
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/* Check for unresolved deltas */
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for (i = 0; i < nr_deltas; i++) {
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if (deltas[i].obj->real_type == OBJ_REF_DELTA ||
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deltas[i].obj->real_type == OBJ_OFS_DELTA)
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die("pack has unresolved deltas");
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static int write_compressed(int fd, void *in, unsigned int size)
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{
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z_stream stream;
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unsigned long maxsize;
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void *out;
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memset(&stream, 0, sizeof(stream));
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deflateInit(&stream, zlib_compression_level);
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maxsize = deflateBound(&stream, size);
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out = xmalloc(maxsize);
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/* Compress it */
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stream.next_in = in;
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stream.avail_in = size;
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stream.next_out = out;
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stream.avail_out = maxsize;
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while (deflate(&stream, Z_FINISH) == Z_OK);
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deflateEnd(&stream);
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size = stream.total_out;
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write_or_die(fd, out, size);
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free(out);
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return size;
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}
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static void append_obj_to_pack(void *buf,
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unsigned long size, enum object_type type)
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{
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struct object_entry *obj = &objects[nr_objects++];
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unsigned char header[10];
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unsigned long s = size;
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int n = 0;
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unsigned char c = (type << 4) | (s & 15);
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s >>= 4;
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while (s) {
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header[n++] = c | 0x80;
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c = s & 0x7f;
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s >>= 7;
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}
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header[n++] = c;
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write_or_die(output_fd, header, n);
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obj[1].offset = obj[0].offset + n;
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obj[1].offset += write_compressed(output_fd, buf, size);
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sha1_object(buf, size, type, obj->sha1);
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}
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static int delta_pos_compare(const void *_a, const void *_b)
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{
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struct delta_entry *a = *(struct delta_entry **)_a;
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struct delta_entry *b = *(struct delta_entry **)_b;
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return a->obj_no - b->obj_no;
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}
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static void fix_unresolved_deltas(int nr_unresolved)
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{
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struct delta_entry **sorted_by_pos;
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int i, n = 0;
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/*
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* Since many unresolved deltas may well be themselves base objects
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* for more unresolved deltas, we really want to include the
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* smallest number of base objects that would cover as much delta
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* as possible by picking the
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* trunc deltas first, allowing for other deltas to resolve without
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* additional base objects. Since most base objects are to be found
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* before deltas depending on them, a good heuristic is to start
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* resolving deltas in the same order as their position in the pack.
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*/
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sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
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for (i = 0; i < nr_deltas; i++) {
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if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
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continue;
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sorted_by_pos[n++] = &deltas[i];
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}
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qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
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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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char type[10];
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enum object_type obj_type;
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int j, first, last;
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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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continue;
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if (!strcmp(type, blob_type)) obj_type = OBJ_BLOB;
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else if (!strcmp(type, tree_type)) obj_type = OBJ_TREE;
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else if (!strcmp(type, commit_type)) obj_type = OBJ_COMMIT;
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else if (!strcmp(type, tag_type)) obj_type = OBJ_TAG;
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else die("base object %s is of type '%s'",
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sha1_to_hex(d->base.sha1), type);
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find_delta_childs(&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, obj_type);
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}
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append_obj_to_pack(data, size, obj_type);
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free(data);
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}
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free(sorted_by_pos);
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}
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static void readjust_pack_header_and_sha1(unsigned char *sha1)
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{
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struct pack_header hdr;
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SHA_CTX ctx;
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int size;
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/* Rewrite pack header with updated object number */
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if (lseek(output_fd, 0, SEEK_SET) != 0)
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die("cannot seek back: %s", strerror(errno));
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if (xread(output_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
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die("cannot read pack header back: %s", strerror(errno));
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hdr.hdr_entries = htonl(nr_objects);
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if (lseek(output_fd, 0, SEEK_SET) != 0)
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die("cannot seek back: %s", strerror(errno));
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write_or_die(output_fd, &hdr, sizeof(hdr));
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if (lseek(output_fd, 0, SEEK_SET) != 0)
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die("cannot seek back: %s", strerror(errno));
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/* Recompute and store the new pack's SHA1 */
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SHA1_Init(&ctx);
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do {
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unsigned char *buf[4096];
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size = xread(output_fd, buf, sizeof(buf));
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if (size < 0)
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die("cannot read pack data back: %s", strerror(errno));
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SHA1_Update(&ctx, buf, size);
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} while (size > 0);
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SHA1_Final(sha1, &ctx);
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write_or_die(output_fd, sha1, 20);
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}
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static int sha1_compare(const void *_a, const void *_b)
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@ -588,7 +733,7 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
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int main(int argc, char **argv)
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{
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int i;
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int i, fix_thin_pack = 0;
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const char *curr_pack, *pack_name = NULL;
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const char *curr_index, *index_name = NULL;
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char *index_name_buf = NULL;
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@ -600,6 +745,8 @@ int main(int argc, char **argv)
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if (*arg == '-') {
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if (!strcmp(arg, "--stdin")) {
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from_stdin = 1;
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} else if (!strcmp(arg, "--fix-thin")) {
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fix_thin_pack = 1;
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} else if (!strcmp(arg, "-o")) {
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if (index_name || (i+1) >= argc)
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usage(index_pack_usage);
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@ -616,6 +763,8 @@ int main(int argc, char **argv)
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if (!pack_name && !from_stdin)
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usage(index_pack_usage);
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if (fix_thin_pack && !from_stdin)
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die("--fix-thin cannot be used without --stdin");
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if (!index_name && pack_name) {
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int len = strlen(pack_name);
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if (!has_extension(pack_name, ".pack"))
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@ -629,9 +778,28 @@ int main(int argc, char **argv)
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curr_pack = open_pack_file(pack_name);
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parse_pack_header();
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objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
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deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
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objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
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deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
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parse_pack_objects(sha1);
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if (nr_deltas != nr_resolved_deltas) {
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if (fix_thin_pack) {
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int nr_unresolved = nr_deltas - nr_resolved_deltas;
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if (nr_unresolved <= 0)
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die("confusion beyond insanity");
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objects = xrealloc(objects,
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(nr_objects + nr_unresolved + 1)
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* sizeof(*objects));
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fix_unresolved_deltas(nr_unresolved);
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readjust_pack_header_and_sha1(sha1);
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}
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if (nr_deltas != nr_resolved_deltas)
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die("pack has %d unresolved deltas",
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nr_deltas - nr_resolved_deltas);
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} else {
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/* Flush remaining pack final 20-byte SHA1. */
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use(20);
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flush();
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}
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free(deltas);
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curr_index = write_index_file(index_name, sha1);
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final(pack_name, curr_pack, index_name, curr_index, sha1);
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