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/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#ifndef INCLUDE_pack_h__
#define INCLUDE_pack_h__
#include <zlib.h>
#include "git2/oid.h"
#include "common.h"
#include "map.h"
#include "mwindow.h"
#include "odb.h"
#include "oidmap.h"
#define GIT_PACK_FILE_MODE 0444
#define PACK_SIGNATURE 0x5041434b /* "PACK" */
#define PACK_VERSION 2
#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
struct git_pack_header {
uint32_t hdr_signature;
uint32_t hdr_version;
uint32_t hdr_entries;
};
/*
* The first four bytes of index formats later than version 1 should
* start with this signature, as all older git binaries would find this
* value illegal and abort reading the file.
*
* This is the case because the number of objects in a packfile
* cannot exceed 1,431,660,000 as every object would need at least
* 3 bytes of data and the overall packfile cannot exceed 4 GiB with
* version 1 of the index file due to the offsets limited to 32 bits.
* Clearly the signature exceeds this maximum.
*
* Very old git binaries will also compare the first 4 bytes to the
* next 4 bytes in the index and abort with a "non-monotonic index"
* error if the second 4 byte word is smaller than the first 4
* byte word. This would be true in the proposed future index
* format as idx_signature would be greater than idx_version.
*/
#define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */
struct git_pack_idx_header {
uint32_t idx_signature;
uint32_t idx_version;
};
typedef struct git_pack_cache_entry {
size_t last_usage; /* enough? */
git_atomic refcount;
git_rawobj raw;
} git_pack_cache_entry;
#include "offmap.h"
GIT__USE_OFFMAP;
GIT__USE_OIDMAP;
#define GIT_PACK_CACHE_MEMORY_LIMIT 16 * 1024 * 1024
#define GIT_PACK_CACHE_SIZE_LIMIT 1024 * 1024 /* don't bother caching anything over 1MB */
typedef struct {
size_t memory_used;
size_t memory_limit;
size_t use_ctr;
git_mutex lock;
git_offmap *entries;
} git_pack_cache;
struct git_pack_file {
git_mwindow_file mwf;
git_map index_map;
git_mutex lock; /* protect updates to mwf and index_map */
uint32_t num_objects;
uint32_t num_bad_objects;
git_oid *bad_object_sha1; /* array of git_oid */
int index_version;
git_time_t mtime;
unsigned pack_local:1, pack_keep:1, has_cache:1;
git_oid sha1;
git_oidmap *idx_cache;
git_oid **oids;
git_pack_cache bases; /* delta base cache */
/* something like ".git/objects/pack/xxxxx.pack" */
char pack_name[GIT_FLEX_ARRAY]; /* more */
};
struct git_pack_entry {
git_off_t offset;
git_oid sha1;
struct git_pack_file *p;
};
typedef struct git_packfile_stream {
git_off_t curpos;
int done;
z_stream zstream;
struct git_pack_file *p;
git_mwindow *mw;
} git_packfile_stream;
int git_packfile_unpack_header(
size_t *size_p,
git_otype *type_p,
git_mwindow_file *mwf,
git_mwindow **w_curs,
git_off_t *curpos);
int git_packfile_resolve_header(
size_t *size_p,
git_otype *type_p,
struct git_pack_file *p,
git_off_t offset);
int git_packfile_unpack(git_rawobj *obj, struct git_pack_file *p, git_off_t *obj_offset);
int packfile_unpack_compressed(
git_rawobj *obj,
struct git_pack_file *p,
git_mwindow **w_curs,
git_off_t *curpos,
size_t size,
git_otype type);
int git_packfile_stream_open(git_packfile_stream *obj, struct git_pack_file *p, git_off_t curpos);
ssize_t git_packfile_stream_read(git_packfile_stream *obj, void *buffer, size_t len);
void git_packfile_stream_free(git_packfile_stream *obj);
git_off_t get_delta_base(struct git_pack_file *p, git_mwindow **w_curs,
git_off_t *curpos, git_otype type,
git_off_t delta_obj_offset);
void git_packfile_free(struct git_pack_file *p);
int git_packfile_alloc(struct git_pack_file **pack_out, const char *path);
int git_pack_entry_find(
struct git_pack_entry *e,
struct git_pack_file *p,
const git_oid *short_oid,
size_t len);
int git_pack_foreach_entry(
struct git_pack_file *p,
git_odb_foreach_cb cb,
void *data);
#endif
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