1 #ifndef PACK_H 2 #define PACK_H 3 4 #include "object.h" 5 #include "csum-file.h" 6 7 struct repository; 8 9 /* 10 * Packed object header 11 */ 12 #define PACK_SIGNATURE 0x5041434b /* "PACK" */ 13 #define PACK_VERSION 2 14 #define pack_version_ok(v) ((v) == htonl(2) || (v) == htonl(3)) 15 struct pack_header { 16 uint32_t hdr_signature; 17 uint32_t hdr_version; 18 uint32_t hdr_entries; 19 }; 20 21 /* 22 * The first four bytes of index formats later than version 1 should 23 * start with this signature, as all older git binaries would find this 24 * value illegal and abort reading the file. 25 * 26 * This is the case because the number of objects in a packfile 27 * cannot exceed 1,431,660,000 as every object would need at least 28 * 3 bytes of data and the overall packfile cannot exceed 4 GiB with 29 * version 1 of the index file due to the offsets limited to 32 bits. 30 * Clearly the signature exceeds this maximum. 31 * 32 * Very old git binaries will also compare the first 4 bytes to the 33 * next 4 bytes in the index and abort with a "non-monotonic index" 34 * error if the second 4 byte word is smaller than the first 4 35 * byte word. This would be true in the proposed future index 36 * format as idx_signature would be greater than idx_version. 37 */ 38 #define PACK_IDX_SIGNATURE 0xff744f63 /* "\377tOc" */ 39 40 struct pack_idx_option { 41 unsigned flags; 42 /* flag bits */ 43 #define WRITE_IDX_VERIFY 01 /* verify only, do not write the idx file */ 44 #define WRITE_IDX_STRICT 02 45 46 uint32_t version; 47 uint32_t off32_limit; 48 49 /* 50 * List of offsets that would fit within off32_limit but 51 * need to be written out as 64-bit entity for byte-for-byte 52 * verification. 53 */ 54 int anomaly_alloc, anomaly_nr; 55 uint32_t *anomaly; 56 }; 57 58 void reset_pack_idx_option(struct pack_idx_option *); 59 60 /* 61 * Packed object index header 62 */ 63 struct pack_idx_header { 64 uint32_t idx_signature; 65 uint32_t idx_version; 66 }; 67 68 /* 69 * Common part of object structure used for write_idx_file 70 */ 71 struct pack_idx_entry { 72 struct object_id oid; 73 uint32_t crc32; 74 off_t offset; 75 }; 76 77 78 struct progress; 79 /* Note, the data argument could be NULL if object type is blob */ 80 typedef int (*verify_fn)(const struct object_id *, enum object_type, unsigned long, void*, int*); 81 82 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); 83 int check_pack_crc(struct packed_git *p, struct pack_window **w_curs, off_t offset, off_t len, unsigned int nr); 84 int verify_pack_index(struct packed_git *); 85 int verify_pack(struct repository *, struct packed_git *, verify_fn fn, struct progress *, uint32_t); 86 off_t write_pack_header(struct hashfile *f, uint32_t); 87 void fixup_pack_header_footer(int, unsigned char *, const char *, uint32_t, unsigned char *, off_t); 88 char *index_pack_lockfile(int fd); 89 90 /* 91 * The "hdr" output buffer should be at least this big, which will handle sizes 92 * up to 2^67. 93 */ 94 #define MAX_PACK_OBJECT_HEADER 10 95 int encode_in_pack_object_header(unsigned char *hdr, int hdr_len, 96 enum object_type, uintmax_t); 97 98 #define PH_ERROR_EOF (-1) 99 #define PH_ERROR_PACK_SIGNATURE (-2) 100 #define PH_ERROR_PROTOCOL (-3) 101 int read_pack_header(int fd, struct pack_header *); 102 103 struct hashfile *create_tmp_packfile(char **pack_tmp_name); 104 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[]); 105 106 #endif 107