| 1 | #include "git-compat-util.h" |
| 2 | #include "gettext.h" |
| 3 | #include "pack-mtimes.h" |
| 4 | #include "odb.h" |
| 5 | #include "packfile.h" |
| 6 | #include "strbuf.h" |
| 7 | |
| 8 | static char *pack_mtimes_filename(struct packed_git *p) |
| 9 | { |
| 10 | size_t len; |
| 11 | if (!strip_suffix(p->pack_name, ".pack", &len)) |
| 12 | BUG("pack_name does not end in .pack"); |
| 13 | return xstrfmt("%.*s.mtimes", (int)len, p->pack_name); |
| 14 | } |
| 15 | |
| 16 | #define MTIMES_HEADER_SIZE (12) |
| 17 | |
| 18 | struct mtimes_header { |
| 19 | uint32_t signature; |
| 20 | uint32_t version; |
| 21 | uint32_t hash_id; |
| 22 | }; |
| 23 | |
| 24 | static int load_pack_mtimes_file(char *mtimes_file, |
| 25 | uint32_t num_objects, |
| 26 | const uint32_t **data_p, size_t *len_p) |
| 27 | { |
| 28 | int fd, ret = 0; |
| 29 | struct stat st; |
| 30 | uint32_t *data = NULL; |
| 31 | size_t mtimes_size, expected_size; |
| 32 | struct mtimes_header header; |
| 33 | |
| 34 | fd = git_open(mtimes_file); |
| 35 | |
| 36 | if (fd < 0) { |
| 37 | ret = -1; |
| 38 | goto cleanup; |
| 39 | } |
| 40 | if (fstat(fd, &st)) { |
| 41 | ret = error_errno(_("failed to read %s"), mtimes_file); |
| 42 | goto cleanup; |
| 43 | } |
| 44 | |
| 45 | mtimes_size = xsize_t(st.st_size); |
| 46 | |
| 47 | if (mtimes_size < MTIMES_HEADER_SIZE) { |
| 48 | ret = error(_("mtimes file %s is too small"), mtimes_file); |
| 49 | goto cleanup; |
| 50 | } |
| 51 | |
| 52 | data = xmmap(NULL, mtimes_size, PROT_READ, MAP_PRIVATE, fd, 0); |
| 53 | |
| 54 | header.signature = ntohl(data[0]); |
| 55 | header.version = ntohl(data[1]); |
| 56 | header.hash_id = ntohl(data[2]); |
| 57 | |
| 58 | if (header.signature != MTIMES_SIGNATURE) { |
| 59 | ret = error(_("mtimes file %s has unknown signature"), mtimes_file); |
| 60 | goto cleanup; |
| 61 | } |
| 62 | |
| 63 | if (header.version != 1) { |
| 64 | ret = error(_("mtimes file %s has unsupported version %"PRIu32), |
| 65 | mtimes_file, header.version); |
| 66 | goto cleanup; |
| 67 | } |
| 68 | |
| 69 | if (!(header.hash_id == 1 || header.hash_id == 2)) { |
| 70 | ret = error(_("mtimes file %s has unsupported hash id %"PRIu32), |
| 71 | mtimes_file, header.hash_id); |
| 72 | goto cleanup; |
| 73 | } |
| 74 | |
| 75 | |
| 76 | expected_size = MTIMES_HEADER_SIZE; |
| 77 | expected_size = st_add(expected_size, st_mult(sizeof(uint32_t), num_objects)); |
| 78 | expected_size = st_add(expected_size, 2 * (header.hash_id == 1 ? GIT_SHA1_RAWSZ : GIT_SHA256_RAWSZ)); |
| 79 | |
| 80 | if (mtimes_size != expected_size) { |
| 81 | ret = error(_("mtimes file %s is corrupt"), mtimes_file); |
| 82 | goto cleanup; |
| 83 | } |
| 84 | |
| 85 | cleanup: |
| 86 | if (ret) { |
| 87 | if (data) |
| 88 | munmap(data, mtimes_size); |
| 89 | } else { |
| 90 | *len_p = mtimes_size; |
| 91 | *data_p = data; |
| 92 | } |
| 93 | |
| 94 | if (fd >= 0) |
| 95 | close(fd); |
| 96 | return ret; |
| 97 | } |
| 98 | |
| 99 | int load_pack_mtimes(struct packed_git *p) |
| 100 | { |
| 101 | char *mtimes_name = NULL; |
| 102 | int ret = 0; |
| 103 | |
| 104 | if (!p->is_cruft) |
| 105 | return ret; /* not a cruft pack */ |
| 106 | if (p->mtimes_map) |
| 107 | return ret; /* already loaded */ |
| 108 | |
| 109 | ret = open_pack_index(p); |
| 110 | if (ret < 0) |
| 111 | goto cleanup; |
| 112 | |
| 113 | mtimes_name = pack_mtimes_filename(p); |
| 114 | ret = load_pack_mtimes_file(mtimes_name, |
| 115 | p->num_objects, |
| 116 | &p->mtimes_map, |
| 117 | &p->mtimes_size); |
| 118 | cleanup: |
| 119 | free(mtimes_name); |
| 120 | return ret; |
| 121 | } |
| 122 | |
| 123 | uint32_t nth_packed_mtime(struct packed_git *p, uint32_t pos) |
| 124 | { |
| 125 | if (!p->mtimes_map) |
| 126 | BUG("pack .mtimes file not loaded for %s", p->pack_name); |
| 127 | if (p->num_objects <= pos) |
| 128 | BUG("pack .mtimes out-of-bounds (%"PRIu32" vs %"PRIu32")", |
| 129 | pos, p->num_objects); |
| 130 | |
| 131 | return get_be32(p->mtimes_map + pos + 3); |
| 132 | } |