116 lines
3.8 KiB

#ifndef PACK_H
#define PACK_H
#include "object.h"
#include "csum-file.h"
struct repository;
* Packed object header
#define PACK_SIGNATURE 0x5041434b /* "PACK" */
#define PACK_VERSION 2
#define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3))
struct 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 pack_idx_option {
unsigned flags;
/* flag bits */
#define WRITE_IDX_VERIFY 01 /* verify only, do not write the idx file */
#define WRITE_REV 04
#define WRITE_REV_VERIFY 010
uint32_t version;
uint32_t off32_limit;
* List of offsets that would fit within off32_limit but
* need to be written out as 64-bit entity for byte-for-byte
* verification.
int anomaly_alloc, anomaly_nr;
uint32_t *anomaly;
void reset_pack_idx_option(struct pack_idx_option *);
* Packed object index header
struct pack_idx_header {
uint32_t idx_signature;
uint32_t idx_version;
* Common part of object structure used for write_idx_file
struct pack_idx_entry {
struct object_id oid;
uint32_t crc32;
off_t offset;
struct progress;
/* Note, the data argument could be NULL if object type is blob */
typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*);
const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, const unsigned char *sha1);
int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr);
int verify_pack_index(struct packed_git *);
int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t);
off_t write_pack_header(struct hashfile *f, uint32_t);
void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t);
char *index_pack_lockfile(int fd, int *is_well_formed);
struct ref;
void write_promisor_file(const char *promisor_name, struct ref **sought, int nr_sought);
const char *write_rev_file(const char *rev_name, struct pack_idx_entry **objects, uint32_t nr_objects, const unsigned char *hash, unsigned flags);
const char *write_rev_file_order(const char *rev_name, uint32_t *pack_order, uint32_t nr_objects, const unsigned char *hash, unsigned flags);
* The "hdr" output buffer should be at least this big, which will handle sizes
* up to 2^67.
int encode_in_pack_object_header(unsigned char *hdr, int hdr_len,
enum object_type, uintmax_t);
#define PH_ERROR_EOF (-1)
#define PH_ERROR_PROTOCOL (-3)
int read_pack_header(int fd, struct pack_header *);
struct hashfile *create_tmp_packfile(char **pack_tmp_name);
void finish_tmp_packfile(struct strbuf *name_buffer, const char *pack_tmp_name, struct pack_idx_entry **written_list, uint32_t nr_written, struct pack_idx_option *pack_idx_opts, unsigned char sha1[]);