2 718b3ab0 2018-03-17 stsp * Copyright (c) 2018 Stefan Sperling <stsp@openbsd.org>
4 718b3ab0 2018-03-17 stsp * Permission to use, copy, modify, and distribute this software for any
5 718b3ab0 2018-03-17 stsp * purpose with or without fee is hereby granted, provided that the above
6 718b3ab0 2018-03-17 stsp * copyright notice and this permission notice appear in all copies.
8 718b3ab0 2018-03-17 stsp * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 718b3ab0 2018-03-17 stsp * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 718b3ab0 2018-03-17 stsp * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 718b3ab0 2018-03-17 stsp * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 718b3ab0 2018-03-17 stsp * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 718b3ab0 2018-03-17 stsp * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 718b3ab0 2018-03-17 stsp * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 718b3ab0 2018-03-17 stsp /* An open pack file. */
18 718b3ab0 2018-03-17 stsp struct got_pack {
19 718b3ab0 2018-03-17 stsp char *path_packfile;
21 718b3ab0 2018-03-17 stsp size_t filesize;
24 718b3ab0 2018-03-17 stsp void got_pack_close(struct got_pack *);
26 718b3ab0 2018-03-17 stsp /* See Documentation/technical/pack-format.txt in Git. */
28 718b3ab0 2018-03-17 stsp struct got_packidx_trailer {
29 718b3ab0 2018-03-17 stsp u_int8_t packfile_sha1[SHA1_DIGEST_LENGTH];
30 718b3ab0 2018-03-17 stsp u_int8_t packidx_sha1[SHA1_DIGEST_LENGTH];
31 718b3ab0 2018-03-17 stsp } __attribute__((__packed__));
33 57b35b75 2018-06-22 stsp struct got_packidx_object_id {
34 57b35b75 2018-06-22 stsp u_int8_t sha1[SHA1_DIGEST_LENGTH];
35 57b35b75 2018-06-22 stsp } __attribute__((__packed__));
37 718b3ab0 2018-03-17 stsp /* Ignore pack index version 1 which is no longer written by Git. */
38 718b3ab0 2018-03-17 stsp #define GOT_PACKIDX_VERSION 2
40 718b3ab0 2018-03-17 stsp struct got_packidx_v2_hdr {
41 57b35b75 2018-06-22 stsp uint32_t *magic; /* big endian */
42 718b3ab0 2018-03-17 stsp #define GOT_PACKIDX_V2_MAGIC 0xff744f63 /* "\377t0c" */
43 57b35b75 2018-06-22 stsp uint32_t *version;
46 718b3ab0 2018-03-17 stsp * Each entry N in the fanout table contains the number of objects in
47 718b3ab0 2018-03-17 stsp * the packfile whose SHA1 begins with a byte less than or equal to N.
48 718b3ab0 2018-03-17 stsp * The last entry (index 255) contains the number of objects in the
49 718b3ab0 2018-03-17 stsp * pack file whose first SHA1 byte is <= 0xff, and thus records the
50 718b3ab0 2018-03-17 stsp * total number of objects in the pack file. All pointer variables
51 718b3ab0 2018-03-17 stsp * below point to tables with a corresponding number of entries.
53 57b35b75 2018-06-22 stsp uint32_t *fanout_table; /* values are big endian */
54 57b35b75 2018-06-22 stsp #define GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS (0xff + 1)
56 718b3ab0 2018-03-17 stsp /* Sorted SHA1 checksums for each object in the pack file. */
57 57b35b75 2018-06-22 stsp struct got_packidx_object_id *sorted_ids;
59 718b3ab0 2018-03-17 stsp /* CRC32 of the packed representation of each object. */
60 718b3ab0 2018-03-17 stsp uint32_t *crc32;
62 718b3ab0 2018-03-17 stsp /* Offset into the pack file for each object. */
63 718b3ab0 2018-03-17 stsp uint32_t *offsets; /* values are big endian */
64 718b3ab0 2018-03-17 stsp #define GOT_PACKIDX_OFFSET_VAL_MASK 0x7fffffff
65 718b3ab0 2018-03-17 stsp #define GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX 0x80000000
67 718b3ab0 2018-03-17 stsp /* Large offsets table is empty for pack files < 2 GB. */
68 718b3ab0 2018-03-17 stsp uint64_t *large_offsets; /* values are big endian */
70 57b35b75 2018-06-22 stsp struct got_packidx_trailer *trailer;
73 6fd11751 2018-06-04 stsp /* An open pack index file. */
74 6fd11751 2018-06-04 stsp struct got_packidx {
75 6fd11751 2018-06-04 stsp char *path_packidx; /* actual on-disk path */
77 57b35b75 2018-06-22 stsp uint8_t *map;
79 57b35b75 2018-06-22 stsp struct got_packidx_v2_hdr hdr; /* convenient pointers into map */
82 718b3ab0 2018-03-17 stsp struct got_packfile_hdr {
83 718b3ab0 2018-03-17 stsp uint32_t signature;
84 718b3ab0 2018-03-17 stsp #define GOT_PACKFILE_SIGNATURE 0x5041434b /* 'P' 'A' 'C' 'K' */
85 718b3ab0 2018-03-17 stsp uint32_t version; /* big endian */
86 718b3ab0 2018-03-17 stsp #define GOT_PACKFILE_VERSION 2
87 718b3ab0 2018-03-17 stsp uint32_t nobjects; /* big endian */
90 718b3ab0 2018-03-17 stsp struct got_packfile_obj_hdr {
92 718b3ab0 2018-03-17 stsp * The object size field uses a variable length encoding:
93 718b3ab0 2018-03-17 stsp * size0...sizeN form a 4+7+7+...+7 bit integer, where size0 is the
94 718b3ab0 2018-03-17 stsp * least significant part and sizeN is the most significant part.
95 718b3ab0 2018-03-17 stsp * If the MSB of a size byte is set, an additional size byte follows.
96 718b3ab0 2018-03-17 stsp * Of the 7 remaining bits of size0, the first 3 bits indicate the
97 718b3ab0 2018-03-17 stsp * object's type, and the remaining 4 bits contribute to the size.
99 718b3ab0 2018-03-17 stsp uint8_t *size; /* variable length */
100 718b3ab0 2018-03-17 stsp #define GOT_PACK_OBJ_SIZE_MORE 0x80
101 718b3ab0 2018-03-17 stsp #define GOT_PACK_OBJ_SIZE0_TYPE_MASK 0x70 /* See struct got_object->type */
102 718b3ab0 2018-03-17 stsp #define GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT 4
103 718b3ab0 2018-03-17 stsp #define GOT_PACK_OBJ_SIZE0_VAL_MASK 0x0f
104 718b3ab0 2018-03-17 stsp #define GOT_PACK_OBJ_SIZE_VAL_MASK 0x7f
107 718b3ab0 2018-03-17 stsp /* If object is not a DELTA type. */
108 718b3ab0 2018-03-17 stsp struct got_packfile_object_data {
109 718b3ab0 2018-03-17 stsp uint8_t *data; /* compressed */
112 718b3ab0 2018-03-17 stsp /* If object is of type GOT_OBJ_TYPE_REF_DELTA. */
113 718b3ab0 2018-03-17 stsp struct got_packfile_object_data_ref_delta {
114 718b3ab0 2018-03-17 stsp uint8_t sha1[SHA1_DIGEST_LENGTH];
115 718b3ab0 2018-03-17 stsp uint8_t *delta_data; /* compressed */
118 718b3ab0 2018-03-17 stsp /* If object is of type GOT_OBJ_TYPE_OFFSET_DELTA. */
119 718b3ab0 2018-03-17 stsp struct got_packfile_object_data_offset_delta {
121 718b3ab0 2018-03-17 stsp * This offset is interpreted as a negative offset from
122 718b3ab0 2018-03-17 stsp * the got_packfile_obj_hdr corresponding to this object.
123 718b3ab0 2018-03-17 stsp * The size provided in the header specifies the amount
124 718b3ab0 2018-03-17 stsp * of compressed delta data that follows.
126 718b3ab0 2018-03-17 stsp * This field uses a variable length encoding of N bytes,
127 718b3ab0 2018-03-17 stsp * where the MSB is always set except for the last byte.
128 718b3ab0 2018-03-17 stsp * The value is encoded as a series of N 7 bit integers,
129 718b3ab0 2018-03-17 stsp * which are concatenated, and if N > 1 the value 2^7 +
130 718b3ab0 2018-03-17 stsp * 2^14 + ... + 2^(7 * (n-1)) is added to the result.
132 718b3ab0 2018-03-17 stsp uint8_t *offset; /* variable length */
133 718b3ab0 2018-03-17 stsp #define GOT_PACK_OBJ_DELTA_OFF_MORE 0x80
134 718b3ab0 2018-03-17 stsp #define GOT_PACK_OBJ_DELTA_OFF_VAL_MASK 0x7f
135 718b3ab0 2018-03-17 stsp uint8_t *delta_data; /* compressed */
138 718b3ab0 2018-03-17 stsp struct got_packfile_obj_data {
140 718b3ab0 2018-03-17 stsp struct got_packfile_object_data data;
141 718b3ab0 2018-03-17 stsp struct got_packfile_object_data_ref_delta ref_delta;
142 718b3ab0 2018-03-17 stsp struct got_packfile_object_data_offset_delta offset_delta;
143 718b3ab0 2018-03-17 stsp } __attribute__((__packed__));
144 718b3ab0 2018-03-17 stsp } __attribute__((__packed__));
146 6fd11751 2018-06-04 stsp const struct got_error *got_packidx_open(struct got_packidx **,
147 718b3ab0 2018-03-17 stsp const char *);
148 57b35b75 2018-06-22 stsp const struct got_error* got_packidx_close(struct got_packidx *);
150 718b3ab0 2018-03-17 stsp const struct got_error *got_packfile_open_object(struct got_object **,
151 718b3ab0 2018-03-17 stsp struct got_object_id *, struct got_repository *);
152 718b3ab0 2018-03-17 stsp const struct got_error *got_packfile_extract_object(FILE **,
153 718b3ab0 2018-03-17 stsp struct got_object *, struct got_repository *);
154 718b3ab0 2018-03-17 stsp const struct got_error *got_packfile_extract_object_to_mem(uint8_t **, size_t *,
155 718b3ab0 2018-03-17 stsp struct got_object *, struct got_repository *);
