diff options
Diffstat (limited to 'pack.h')
| -rw-r--r-- | pack.h | 92 |
1 files changed, 71 insertions, 21 deletions
@@ -1,20 +1,7 @@ #ifndef PACK_H #define PACK_H -/* - * The packed object type is stored in 3 bits. - * The type value 0 is a reserved prefix if ever there is more than 7 - * object types, or any future format extensions. - */ -enum object_type { - OBJ_EXT = 0, - OBJ_COMMIT = 1, - OBJ_TREE = 2, - OBJ_BLOB = 3, - OBJ_TAG = 4, - /* 5/6 for future expansion */ - OBJ_DELTA = 7, -}; +#include "object.h" /* * Packed object header @@ -23,13 +10,76 @@ enum object_type { #define PACK_VERSION 2 #define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3)) struct pack_header { - unsigned int hdr_signature; - unsigned int hdr_version; - unsigned int hdr_entries; + 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 + + 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; }; -extern int verify_pack(struct packed_git *, int); -extern int check_reuse_pack_delta(struct packed_git *, unsigned long, - unsigned char *, unsigned long *, - enum object_type *); +extern 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 { + unsigned char sha1[20]; + uint32_t crc32; + off_t offset; +}; + +extern const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects, int nr_objects, const struct pack_idx_option *, unsigned char *sha1); +extern int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr); +extern int verify_pack_index(struct packed_git *); +extern int verify_pack(struct packed_git *); +extern void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t); +extern char *index_pack_lockfile(int fd); +extern int encode_in_pack_object_header(enum object_type, uintmax_t, unsigned char *); + +#define PH_ERROR_EOF (-1) +#define PH_ERROR_PACK_SIGNATURE (-2) +#define PH_ERROR_PROTOCOL (-3) +extern int read_pack_header(int fd, struct pack_header *); #endif |