2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
18 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
19 #define O_NOATIME 01000000
25 const unsigned char null_sha1[20];
27 static unsigned int sha1_file_open_flag = O_NOATIME;
29 static unsigned hexval(char c)
31 if (c >= '0' && c <= '9')
33 if (c >= 'a' && c <= 'f')
35 if (c >= 'A' && c <= 'F')
40 int get_sha1_hex(const char *hex, unsigned char *sha1)
43 for (i = 0; i < 20; i++) {
44 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
53 int safe_create_leading_directories(char *path)
62 pos = strchr(pos, '/');
66 if (!stat(path, &st)) {
68 if (!S_ISDIR(st.st_mode)) {
73 else if (mkdir(path, 0777)) {
77 else if (adjust_shared_perm(path)) {
86 char * sha1_to_hex(const unsigned char *sha1)
89 static char hexbuffer[4][50];
90 static const char hex[] = "0123456789abcdef";
91 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
94 for (i = 0; i < 20; i++) {
95 unsigned int val = *sha1++;
96 *buf++ = hex[val >> 4];
97 *buf++ = hex[val & 0xf];
104 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
107 for (i = 0; i < 20; i++) {
108 static char hex[] = "0123456789abcdef";
109 unsigned int val = sha1[i];
110 char *pos = pathbuf + i*2 + (i > 0);
111 *pos++ = hex[val >> 4];
112 *pos = hex[val & 0xf];
117 * NOTE! This returns a statically allocated buffer, so you have to be
118 * careful about using it. Do a "strdup()" if you need to save the
121 * Also note that this returns the location for creating. Reading
122 * SHA1 file can happen from any alternate directory listed in the
123 * DB_ENVIRONMENT environment variable if it is not found in
124 * the primary object database.
126 char *sha1_file_name(const unsigned char *sha1)
128 static char *name, *base;
131 const char *sha1_file_directory = get_object_directory();
132 int len = strlen(sha1_file_directory);
133 base = xmalloc(len + 60);
134 memcpy(base, sha1_file_directory, len);
135 memset(base+len, 0, 60);
138 name = base + len + 1;
140 fill_sha1_path(name, sha1);
144 char *sha1_pack_name(const unsigned char *sha1)
146 static const char hex[] = "0123456789abcdef";
147 static char *name, *base, *buf;
151 const char *sha1_file_directory = get_object_directory();
152 int len = strlen(sha1_file_directory);
153 base = xmalloc(len + 60);
154 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
155 name = base + len + 11;
160 for (i = 0; i < 20; i++) {
161 unsigned int val = *sha1++;
162 *buf++ = hex[val >> 4];
163 *buf++ = hex[val & 0xf];
169 char *sha1_pack_index_name(const unsigned char *sha1)
171 static const char hex[] = "0123456789abcdef";
172 static char *name, *base, *buf;
176 const char *sha1_file_directory = get_object_directory();
177 int len = strlen(sha1_file_directory);
178 base = xmalloc(len + 60);
179 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
180 name = base + len + 11;
185 for (i = 0; i < 20; i++) {
186 unsigned int val = *sha1++;
187 *buf++ = hex[val >> 4];
188 *buf++ = hex[val & 0xf];
194 struct alternate_object_database *alt_odb_list;
195 static struct alternate_object_database **alt_odb_tail;
197 static void read_info_alternates(const char * alternates, int depth);
200 * Prepare alternate object database registry.
202 * The variable alt_odb_list points at the list of struct
203 * alternate_object_database. The elements on this list come from
204 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
205 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
206 * whose contents is similar to that environment variable but can be
207 * LF separated. Its base points at a statically allocated buffer that
208 * contains "/the/directory/corresponding/to/.git/objects/...", while
209 * its name points just after the slash at the end of ".git/objects/"
210 * in the example above, and has enough space to hold 40-byte hex
211 * SHA1, an extra slash for the first level indirection, and the
214 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
217 const char *objdir = get_object_directory();
218 struct alternate_object_database *ent;
219 struct alternate_object_database *alt;
220 /* 43 = 40-byte + 2 '/' + terminating NUL */
222 int entlen = pfxlen + 43;
225 if (*entry != '/' && relative_base) {
226 /* Relative alt-odb */
228 base_len = strlen(relative_base) + 1;
232 ent = xmalloc(sizeof(*ent) + entlen);
234 if (*entry != '/' && relative_base) {
235 memcpy(ent->base, relative_base, base_len - 1);
236 ent->base[base_len - 1] = '/';
237 memcpy(ent->base + base_len, entry, len);
240 memcpy(ent->base, entry, pfxlen);
242 ent->name = ent->base + pfxlen + 1;
243 ent->base[pfxlen + 3] = '/';
244 ent->base[pfxlen] = ent->base[entlen-1] = 0;
246 /* Detect cases where alternate disappeared */
247 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
248 error("object directory %s does not exist; "
249 "check .git/objects/info/alternates.",
255 /* Prevent the common mistake of listing the same
256 * thing twice, or object directory itself.
258 for (alt = alt_odb_list; alt; alt = alt->next) {
259 if (!memcmp(ent->base, alt->base, pfxlen)) {
264 if (!memcmp(ent->base, objdir, pfxlen)) {
269 /* add the alternate entry */
271 alt_odb_tail = &(ent->next);
274 /* recursively add alternates */
275 read_info_alternates(ent->base, depth + 1);
277 ent->base[pfxlen] = '/';
282 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
283 const char *relative_base, int depth)
285 const char *cp, *last;
288 error("%s: ignoring alternate object stores, nesting too deep.",
296 if (cp < ep && *cp == '#') {
297 while (cp < ep && *cp != sep)
302 while (cp < ep && *cp != sep)
305 if ((*last != '/') && depth) {
306 error("%s: ignoring relative alternate object store %s",
307 relative_base, last);
309 link_alt_odb_entry(last, cp - last,
310 relative_base, depth);
313 while (cp < ep && *cp == sep)
319 static void read_info_alternates(const char * relative_base, int depth)
326 sprintf(path, "%s/info/alternates", relative_base);
327 fd = open(path, O_RDONLY);
330 if (fstat(fd, &st) || (st.st_size == 0)) {
334 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
336 if (map == MAP_FAILED)
339 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
341 munmap(map, st.st_size);
344 void prepare_alt_odb(void)
348 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
353 alt_odb_tail = &alt_odb_list;
354 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
356 read_info_alternates(get_object_directory(), 0);
359 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
361 char *name = sha1_file_name(sha1);
362 struct alternate_object_database *alt;
367 for (alt = alt_odb_list; alt; alt = alt->next) {
369 fill_sha1_path(name, sha1);
370 if (!stat(alt->base, st))
376 #define PACK_MAX_SZ (1<<26)
377 static int pack_used_ctr;
378 static unsigned long pack_mapped;
379 struct packed_git *packed_git;
381 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
386 unsigned long idx_size;
388 int fd = open(path, O_RDONLY);
392 if (fstat(fd, &st)) {
396 idx_size = st.st_size;
397 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
399 if (idx_map == MAP_FAILED)
404 *idx_size_ = idx_size;
406 /* check index map */
407 if (idx_size < 4*256 + 20 + 20)
408 return error("index file too small");
410 for (i = 0; i < 256; i++) {
411 unsigned int n = ntohl(index[i]);
413 return error("non-monotonic index");
419 * - 256 index entries 4 bytes each
420 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
421 * - 20-byte SHA1 of the packfile
422 * - 20-byte SHA1 file checksum
424 if (idx_size != 4*256 + nr * 24 + 20 + 20)
425 return error("wrong index file size");
430 static int unuse_one_packed_git(void)
432 struct packed_git *p, *lru = NULL;
434 for (p = packed_git; p; p = p->next) {
435 if (p->pack_use_cnt || !p->pack_base)
437 if (!lru || p->pack_last_used < lru->pack_last_used)
442 munmap(lru->pack_base, lru->pack_size);
443 lru->pack_base = NULL;
447 void unuse_packed_git(struct packed_git *p)
452 int use_packed_git(struct packed_git *p)
456 /* We created the struct before we had the pack */
457 stat(p->pack_name, &st);
458 if (!S_ISREG(st.st_mode))
459 die("packfile %s not a regular file", p->pack_name);
460 p->pack_size = st.st_size;
466 struct pack_header *hdr;
468 pack_mapped += p->pack_size;
469 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
471 fd = open(p->pack_name, O_RDONLY);
473 die("packfile %s cannot be opened", p->pack_name);
474 if (fstat(fd, &st)) {
476 die("packfile %s cannot be opened", p->pack_name);
478 if (st.st_size != p->pack_size)
479 die("packfile %s size mismatch.", p->pack_name);
480 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
482 if (map == MAP_FAILED)
483 die("packfile %s cannot be mapped.", p->pack_name);
486 /* Check if we understand this pack file. If we don't we're
487 * likely too old to handle it.
490 if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
491 die("packfile %s isn't actually a pack.", p->pack_name);
492 if (!pack_version_ok(hdr->hdr_version))
493 die("packfile %s is version %i and not supported"
494 " (try upgrading GIT to a newer version)",
495 p->pack_name, ntohl(hdr->hdr_version));
497 /* Check if the pack file matches with the index file.
500 if (hashcmp((unsigned char *)(p->index_base) +
502 (unsigned char *)p->pack_base +
503 p->pack_size - 20)) {
504 die("packfile %s does not match index.", p->pack_name);
507 p->pack_last_used = pack_used_ctr++;
512 struct packed_git *add_packed_git(char *path, int path_len, int local)
515 struct packed_git *p;
516 unsigned long idx_size;
518 unsigned char sha1[20];
520 if (check_packed_git_idx(path, &idx_size, &idx_map))
523 /* do we have a corresponding .pack file? */
524 strcpy(path + path_len - 4, ".pack");
525 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
526 munmap(idx_map, idx_size);
529 /* ok, it looks sane as far as we can check without
530 * actually mapping the pack file.
532 p = xmalloc(sizeof(*p) + path_len + 2);
533 strcpy(p->pack_name, path);
534 p->index_size = idx_size;
535 p->pack_size = st.st_size;
536 p->index_base = idx_map;
539 p->pack_last_used = 0;
541 p->pack_local = local;
542 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
543 hashcpy(p->sha1, sha1);
547 struct packed_git *parse_pack_index(unsigned char *sha1)
549 char *path = sha1_pack_index_name(sha1);
550 return parse_pack_index_file(sha1, path);
553 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
555 struct packed_git *p;
556 unsigned long idx_size;
560 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
563 path = sha1_pack_name(sha1);
565 p = xmalloc(sizeof(*p) + strlen(path) + 2);
566 strcpy(p->pack_name, path);
567 p->index_size = idx_size;
569 p->index_base = idx_map;
572 p->pack_last_used = 0;
574 hashcpy(p->sha1, sha1);
578 void install_packed_git(struct packed_git *pack)
580 pack->next = packed_git;
584 static void prepare_packed_git_one(char *objdir, int local)
591 sprintf(path, "%s/pack", objdir);
596 error("unable to open object pack directory: %s: %s",
597 path, strerror(errno));
601 while ((de = readdir(dir)) != NULL) {
602 int namelen = strlen(de->d_name);
603 struct packed_git *p;
605 if (!has_extension(de->d_name, ".idx"))
608 /* we have .idx. Is it a file we can map? */
609 strcpy(path + len, de->d_name);
610 for (p = packed_git; p; p = p->next) {
611 if (!memcmp(path, p->pack_name, len + namelen - 4))
616 p = add_packed_git(path, len + namelen, local);
619 p->next = packed_git;
625 static int prepare_packed_git_run_once = 0;
626 void prepare_packed_git(void)
628 struct alternate_object_database *alt;
630 if (prepare_packed_git_run_once)
632 prepare_packed_git_one(get_object_directory(), 1);
634 for (alt = alt_odb_list; alt; alt = alt->next) {
636 prepare_packed_git_one(alt->base, 0);
639 prepare_packed_git_run_once = 1;
642 static void reprepare_packed_git(void)
644 prepare_packed_git_run_once = 0;
645 prepare_packed_git();
648 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
651 unsigned char real_sha1[20];
655 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
656 SHA1_Update(&c, map, size);
657 SHA1_Final(real_sha1, &c);
658 return hashcmp(sha1, real_sha1) ? -1 : 0;
661 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
666 char *filename = find_sha1_file(sha1, &st);
672 fd = open(filename, O_RDONLY | sha1_file_open_flag);
674 /* See if it works without O_NOATIME */
675 switch (sha1_file_open_flag) {
677 fd = open(filename, O_RDONLY);
685 /* If it failed once, it will probably fail again.
686 * Stop using O_NOATIME
688 sha1_file_open_flag = 0;
690 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
692 if (map == MAP_FAILED)
698 int legacy_loose_object(unsigned char *map)
703 * Is it a zlib-compressed buffer? If so, the first byte
704 * must be 0x78 (15-bit window size, deflated), and the
705 * first 16-bit word is evenly divisible by 31
707 word = (map[0] << 8) + map[1];
708 if (map[0] == 0x78 && !(word % 31))
714 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
719 static const char *typename[8] = {
721 "commit", "tree", "blob", "tag",
726 /* Get the data stream */
727 memset(stream, 0, sizeof(*stream));
728 stream->next_in = map;
729 stream->avail_in = mapsize;
730 stream->next_out = buffer;
731 stream->avail_out = bufsiz;
733 if (legacy_loose_object(map)) {
735 return inflate(stream, 0);
740 type = typename[(c >> 4) & 7];
747 if (bits >= 8*sizeof(long))
750 size += (c & 0x7f) << bits;
755 /* Set up the stream for the rest.. */
756 stream->next_in = map;
757 stream->avail_in = mapsize;
760 /* And generate the fake traditional header */
761 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", type, size);
765 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
767 int bytes = strlen(buffer) + 1;
768 unsigned char *buf = xmalloc(1+size);
771 n = stream->total_out - bytes;
774 memcpy(buf, (char *) buffer + bytes, n);
777 stream->next_out = buf + bytes;
778 stream->avail_out = size - bytes;
779 while (inflate(stream, Z_FINISH) == Z_OK)
788 * We used to just use "sscanf()", but that's actually way
789 * too permissive for what we want to check. So do an anal
790 * object header parse by hand.
792 static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
798 * The type can be at most ten bytes (including the
799 * terminating '\0' that we add), and is followed by
814 * The length must follow immediately, and be in canonical
815 * decimal format (ie "010" is not valid).
822 unsigned long c = *hdr - '0';
826 size = size * 10 + c;
832 * The length must be followed by a zero byte
834 return *hdr ? -1 : 0;
837 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
843 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
844 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
847 return unpack_sha1_rest(&stream, hdr, *size);
850 /* forward declaration for a mutually recursive function */
851 static int packed_object_info(struct pack_entry *entry,
852 char *type, unsigned long *sizep);
854 static int packed_delta_info(unsigned char *base_sha1,
855 unsigned long delta_size,
858 unsigned long *sizep,
859 struct packed_git *p)
861 struct pack_entry base_ent;
864 die("truncated pack file");
866 /* The base entry _must_ be in the same pack */
867 if (!find_pack_entry_one(base_sha1, &base_ent, p))
868 die("failed to find delta-pack base object %s",
869 sha1_to_hex(base_sha1));
871 /* We choose to only get the type of the base object and
872 * ignore potentially corrupt pack file that expects the delta
873 * based on a base with a wrong size. This saves tons of
877 if (packed_object_info(&base_ent, type, NULL))
878 die("cannot get info for delta-pack base");
881 const unsigned char *data;
882 unsigned char delta_head[64];
883 unsigned long result_size;
887 memset(&stream, 0, sizeof(stream));
889 data = stream.next_in = base_sha1 + 20;
890 stream.avail_in = left - 20;
891 stream.next_out = delta_head;
892 stream.avail_out = sizeof(delta_head);
894 inflateInit(&stream);
895 st = inflate(&stream, Z_FINISH);
897 if ((st != Z_STREAM_END) &&
898 stream.total_out != sizeof(delta_head))
899 die("delta data unpack-initial failed");
901 /* Examine the initial part of the delta to figure out
906 /* ignore base size */
907 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
909 /* Read the result size */
910 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
911 *sizep = result_size;
916 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
917 enum object_type *type, unsigned long *sizep)
923 if (offset >= p->pack_size)
924 die("object offset outside of pack file");
925 c = *((unsigned char *)p->pack_base + offset++);
926 *type = (c >> 4) & 7;
930 if (offset >= p->pack_size)
931 die("object offset outside of pack file");
932 c = *((unsigned char *)p->pack_base + offset++);
933 size += (c & 0x7f) << shift;
940 int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
941 unsigned char *base, unsigned long *sizep,
942 enum object_type *kindp)
949 ptr = unpack_object_header(p, ptr, kindp, sizep);
950 if (*kindp != OBJ_DELTA)
952 hashcpy(base, (unsigned char *) p->pack_base + ptr);
959 void packed_object_info_detail(struct pack_entry *e,
962 unsigned long *store_size,
963 unsigned int *delta_chain_length,
964 unsigned char *base_sha1)
966 struct packed_git *p = e->p;
967 unsigned long offset;
969 enum object_type kind;
971 offset = unpack_object_header(p, e->offset, &kind, size);
972 pack = (unsigned char *) p->pack_base + offset;
973 if (kind != OBJ_DELTA)
974 *delta_chain_length = 0;
976 unsigned int chain_length = 0;
977 if (p->pack_size <= offset + 20)
978 die("pack file %s records an incomplete delta base",
980 hashcpy(base_sha1, pack);
982 struct pack_entry base_ent;
985 find_pack_entry_one(pack, &base_ent, p);
986 offset = unpack_object_header(p, base_ent.offset,
988 pack = (unsigned char *) p->pack_base + offset;
990 } while (kind == OBJ_DELTA);
991 *delta_chain_length = chain_length;
998 strcpy(type, type_names[kind]);
1001 die("corrupted pack file %s containing object of kind %d",
1002 p->pack_name, kind);
1004 *store_size = 0; /* notyet */
1007 static int packed_object_info(struct pack_entry *entry,
1008 char *type, unsigned long *sizep)
1010 struct packed_git *p = entry->p;
1011 unsigned long offset, size, left;
1012 unsigned char *pack;
1013 enum object_type kind;
1016 if (use_packed_git(p))
1017 die("cannot map packed file");
1019 offset = unpack_object_header(p, entry->offset, &kind, &size);
1020 pack = (unsigned char *) p->pack_base + offset;
1021 left = p->pack_size - offset;
1025 retval = packed_delta_info(pack, size, left, type, sizep, p);
1026 unuse_packed_git(p);
1032 strcpy(type, type_names[kind]);
1035 die("corrupted pack file %s containing object of kind %d",
1036 p->pack_name, kind);
1040 unuse_packed_git(p);
1044 static void *unpack_compressed_entry(struct packed_git *p,
1045 unsigned long offset,
1050 unsigned char *buffer;
1052 buffer = xmalloc(size + 1);
1054 memset(&stream, 0, sizeof(stream));
1055 stream.next_in = (unsigned char*)p->pack_base + offset;
1056 stream.avail_in = p->pack_size - offset;
1057 stream.next_out = buffer;
1058 stream.avail_out = size;
1060 inflateInit(&stream);
1061 st = inflate(&stream, Z_FINISH);
1062 inflateEnd(&stream);
1063 if ((st != Z_STREAM_END) || stream.total_out != size) {
1071 static void *unpack_delta_entry(struct packed_git *p,
1072 unsigned long offset,
1073 unsigned long delta_size,
1075 unsigned long *sizep)
1077 struct pack_entry base_ent;
1078 void *delta_data, *result, *base;
1079 unsigned long result_size, base_size;
1080 unsigned char* base_sha1;
1082 if ((offset + 20) >= p->pack_size)
1083 die("truncated pack file");
1085 /* The base entry _must_ be in the same pack */
1086 base_sha1 = (unsigned char*)p->pack_base + offset;
1087 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1088 die("failed to find delta-pack base object %s",
1089 sha1_to_hex(base_sha1));
1090 base = unpack_entry_gently(&base_ent, type, &base_size);
1092 die("failed to read delta-pack base object %s",
1093 sha1_to_hex(base_sha1));
1095 delta_data = unpack_compressed_entry(p, offset + 20, delta_size);
1096 result = patch_delta(base, base_size,
1097 delta_data, delta_size,
1100 die("failed to apply delta");
1103 *sizep = result_size;
1107 static void *unpack_entry(struct pack_entry *entry,
1108 char *type, unsigned long *sizep)
1110 struct packed_git *p = entry->p;
1113 if (use_packed_git(p))
1114 die("cannot map packed file");
1115 retval = unpack_entry_gently(entry, type, sizep);
1116 unuse_packed_git(p);
1118 die("corrupted pack file %s", p->pack_name);
1122 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1123 void *unpack_entry_gently(struct pack_entry *entry,
1124 char *type, unsigned long *sizep)
1126 struct packed_git *p = entry->p;
1127 unsigned long offset, size;
1128 enum object_type kind;
1130 offset = unpack_object_header(p, entry->offset, &kind, &size);
1133 return unpack_delta_entry(p, offset, size, type, sizep);
1138 strcpy(type, type_names[kind]);
1140 return unpack_compressed_entry(p, offset, size);
1146 int num_packed_objects(const struct packed_git *p)
1148 /* See check_packed_git_idx() */
1149 return (p->index_size - 20 - 20 - 4*256) / 24;
1152 int nth_packed_object_sha1(const struct packed_git *p, int n,
1153 unsigned char* sha1)
1155 void *index = p->index_base + 256;
1156 if (n < 0 || num_packed_objects(p) <= n)
1158 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1162 int find_pack_entry_one(const unsigned char *sha1,
1163 struct pack_entry *e, struct packed_git *p)
1165 unsigned int *level1_ofs = p->index_base;
1166 int hi = ntohl(level1_ofs[*sha1]);
1167 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1168 void *index = p->index_base + 256;
1171 int mi = (lo + hi) / 2;
1172 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1174 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1175 hashcpy(e->sha1, sha1);
1187 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1189 struct packed_git *p;
1190 prepare_packed_git();
1192 for (p = packed_git; p; p = p->next) {
1193 if (find_pack_entry_one(sha1, e, p))
1199 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1200 struct packed_git *packs)
1202 struct packed_git *p;
1203 struct pack_entry e;
1205 for (p = packs; p; p = p->next) {
1206 if (find_pack_entry_one(sha1, &e, p))
1213 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1216 unsigned long mapsize, size;
1221 map = map_sha1_file(sha1, &mapsize);
1223 struct pack_entry e;
1225 if (find_pack_entry(sha1, &e))
1226 return packed_object_info(&e, type, sizep);
1227 reprepare_packed_git();
1228 if (find_pack_entry(sha1, &e))
1229 return packed_object_info(&e, type, sizep);
1230 return error("unable to find %s", sha1_to_hex(sha1));
1232 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1233 status = error("unable to unpack %s header",
1235 if (parse_sha1_header(hdr, type, &size) < 0)
1236 status = error("unable to parse %s header", sha1_to_hex(sha1));
1242 inflateEnd(&stream);
1243 munmap(map, mapsize);
1247 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1249 struct pack_entry e;
1251 if (!find_pack_entry(sha1, &e)) {
1252 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1255 return unpack_entry(&e, type, size);
1258 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1260 unsigned long mapsize;
1262 struct pack_entry e;
1264 if (find_pack_entry(sha1, &e))
1265 return read_packed_sha1(sha1, type, size);
1266 map = map_sha1_file(sha1, &mapsize);
1268 buf = unpack_sha1_file(map, mapsize, type, size);
1269 munmap(map, mapsize);
1272 reprepare_packed_git();
1273 if (find_pack_entry(sha1, &e))
1274 return read_packed_sha1(sha1, type, size);
1278 void *read_object_with_reference(const unsigned char *sha1,
1279 const char *required_type,
1280 unsigned long *size,
1281 unsigned char *actual_sha1_return)
1285 unsigned long isize;
1286 unsigned char actual_sha1[20];
1288 hashcpy(actual_sha1, sha1);
1290 int ref_length = -1;
1291 const char *ref_type = NULL;
1293 buffer = read_sha1_file(actual_sha1, type, &isize);
1296 if (!strcmp(type, required_type)) {
1298 if (actual_sha1_return)
1299 hashcpy(actual_sha1_return, actual_sha1);
1302 /* Handle references */
1303 else if (!strcmp(type, commit_type))
1305 else if (!strcmp(type, tag_type))
1306 ref_type = "object ";
1311 ref_length = strlen(ref_type);
1313 if (memcmp(buffer, ref_type, ref_length) ||
1314 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1319 /* Now we have the ID of the referred-to object in
1320 * actual_sha1. Check again. */
1324 char *write_sha1_file_prepare(void *buf,
1327 unsigned char *sha1,
1333 /* Generate the header */
1334 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1338 SHA1_Update(&c, hdr, *hdrlen);
1339 SHA1_Update(&c, buf, len);
1340 SHA1_Final(sha1, &c);
1342 return sha1_file_name(sha1);
1346 * Link the tempfile to the final place, possibly creating the
1347 * last directory level as you do so.
1349 * Returns the errno on failure, 0 on success.
1351 static int link_temp_to_file(const char *tmpfile, char *filename)
1356 if (!link(tmpfile, filename))
1360 * Try to mkdir the last path component if that failed.
1362 * Re-try the "link()" regardless of whether the mkdir
1363 * succeeds, since a race might mean that somebody
1367 dir = strrchr(filename, '/');
1370 mkdir(filename, 0777);
1371 if (adjust_shared_perm(filename))
1374 if (!link(tmpfile, filename))
1382 * Move the just written object into its final resting place
1384 int move_temp_to_file(const char *tmpfile, char *filename)
1386 int ret = link_temp_to_file(tmpfile, filename);
1389 * Coda hack - coda doesn't like cross-directory links,
1390 * so we fall back to a rename, which will mean that it
1391 * won't be able to check collisions, but that's not a
1394 * The same holds for FAT formatted media.
1396 * When this succeeds, we just return 0. We have nothing
1399 if (ret && ret != EEXIST) {
1400 if (!rename(tmpfile, filename))
1406 if (ret != EEXIST) {
1407 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1410 /* FIXME!!! Collision check here ? */
1416 static int write_buffer(int fd, const void *buf, size_t len)
1421 size = write(fd, buf, len);
1423 return error("file write: disk full");
1425 if (errno == EINTR || errno == EAGAIN)
1427 return error("file write error (%s)", strerror(errno));
1430 buf = (char *) buf + size;
1435 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1440 c = (type << 4) | (len & 15);
1453 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1457 if (use_legacy_headers) {
1458 while (deflate(stream, 0) == Z_OK)
1462 if (!strcmp(type, blob_type))
1463 obj_type = OBJ_BLOB;
1464 else if (!strcmp(type, tree_type))
1465 obj_type = OBJ_TREE;
1466 else if (!strcmp(type, commit_type))
1467 obj_type = OBJ_COMMIT;
1468 else if (!strcmp(type, tag_type))
1471 die("trying to generate bogus object of type '%s'", type);
1472 hdr = write_binary_header(stream->next_out, obj_type, len);
1473 stream->total_out = hdr;
1474 stream->next_out += hdr;
1475 stream->avail_out -= hdr;
1478 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1481 unsigned char *compressed;
1483 unsigned char sha1[20];
1485 static char tmpfile[PATH_MAX];
1486 unsigned char hdr[50];
1489 /* Normally if we have it in the pack then we do not bother writing
1490 * it out into .git/objects/??/?{38} file.
1492 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1494 hashcpy(returnsha1, sha1);
1495 if (has_sha1_file(sha1))
1497 fd = open(filename, O_RDONLY);
1500 * FIXME!!! We might do collision checking here, but we'd
1501 * need to uncompress the old file and check it. Later.
1507 if (errno != ENOENT) {
1508 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1512 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1514 fd = mkstemp(tmpfile);
1516 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1521 memset(&stream, 0, sizeof(stream));
1522 deflateInit(&stream, zlib_compression_level);
1523 size = 8 + deflateBound(&stream, len+hdrlen);
1524 compressed = xmalloc(size);
1527 stream.next_out = compressed;
1528 stream.avail_out = size;
1530 /* First header.. */
1531 stream.next_in = hdr;
1532 stream.avail_in = hdrlen;
1533 setup_object_header(&stream, type, len);
1535 /* Then the data itself.. */
1536 stream.next_in = buf;
1537 stream.avail_in = len;
1538 while (deflate(&stream, Z_FINISH) == Z_OK)
1540 deflateEnd(&stream);
1541 size = stream.total_out;
1543 if (write_buffer(fd, compressed, size) < 0)
1544 die("unable to write sha1 file");
1549 return move_temp_to_file(tmpfile, filename);
1553 * We need to unpack and recompress the object for writing
1554 * it out to a different file.
1556 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1560 unsigned char *unpacked;
1567 /* need to unpack and recompress it by itself */
1568 unpacked = read_packed_sha1(sha1, type, &len);
1570 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1573 memset(&stream, 0, sizeof(stream));
1574 deflateInit(&stream, zlib_compression_level);
1575 size = deflateBound(&stream, len + hdrlen);
1576 buf = xmalloc(size);
1579 stream.next_out = buf;
1580 stream.avail_out = size;
1582 /* First header.. */
1583 stream.next_in = (void *)hdr;
1584 stream.avail_in = hdrlen;
1585 while (deflate(&stream, 0) == Z_OK)
1588 /* Then the data itself.. */
1589 stream.next_in = unpacked;
1590 stream.avail_in = len;
1591 while (deflate(&stream, Z_FINISH) == Z_OK)
1593 deflateEnd(&stream);
1596 *objsize = stream.total_out;
1600 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1603 unsigned long objsize;
1604 void *buf = map_sha1_file(sha1, &objsize);
1607 retval = write_buffer(fd, buf, objsize);
1608 munmap(buf, objsize);
1612 buf = repack_object(sha1, &objsize);
1613 retval = write_buffer(fd, buf, objsize);
1618 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1619 size_t bufsize, size_t *bufposn)
1621 char tmpfile[PATH_MAX];
1624 unsigned char real_sha1[20];
1625 unsigned char discard[4096];
1629 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1631 local = mkstemp(tmpfile);
1633 return error("Couldn't open %s for %s",
1634 tmpfile, sha1_to_hex(sha1));
1636 memset(&stream, 0, sizeof(stream));
1638 inflateInit(&stream);
1645 stream.avail_in = *bufposn;
1646 stream.next_in = (unsigned char *) buffer;
1648 stream.next_out = discard;
1649 stream.avail_out = sizeof(discard);
1650 ret = inflate(&stream, Z_SYNC_FLUSH);
1651 SHA1_Update(&c, discard, sizeof(discard) -
1653 } while (stream.avail_in && ret == Z_OK);
1654 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1655 die("unable to write sha1 file");
1656 memmove(buffer, buffer + *bufposn - stream.avail_in,
1658 *bufposn = stream.avail_in;
1662 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1667 return error("Connection closed?");
1668 perror("Reading from connection");
1673 inflateEnd(&stream);
1676 SHA1_Final(real_sha1, &c);
1677 if (ret != Z_STREAM_END) {
1679 return error("File %s corrupted", sha1_to_hex(sha1));
1681 if (hashcmp(sha1, real_sha1)) {
1683 return error("File %s has bad hash", sha1_to_hex(sha1));
1686 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1689 int has_pack_index(const unsigned char *sha1)
1692 if (stat(sha1_pack_index_name(sha1), &st))
1697 int has_pack_file(const unsigned char *sha1)
1700 if (stat(sha1_pack_name(sha1), &st))
1705 int has_sha1_pack(const unsigned char *sha1)
1707 struct pack_entry e;
1708 return find_pack_entry(sha1, &e);
1711 int has_sha1_file(const unsigned char *sha1)
1714 struct pack_entry e;
1716 if (find_pack_entry(sha1, &e))
1718 return find_sha1_file(sha1, &st) ? 1 : 0;
1722 * reads from fd as long as possible into a supplied buffer of size bytes.
1723 * If necessary the buffer's size is increased using realloc()
1725 * returns 0 if anything went fine and -1 otherwise
1727 * NOTE: both buf and size may change, but even when -1 is returned
1728 * you still have to free() it yourself.
1730 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1732 char* buf = *return_buf;
1733 unsigned long size = *return_size;
1735 unsigned long off = 0;
1738 iret = xread(fd, buf + off, size - off);
1743 buf = xrealloc(buf, size);
1756 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1758 unsigned long size = 4096;
1759 char *buf = xmalloc(size);
1761 unsigned char hdr[50];
1764 if (read_pipe(fd, &buf, &size)) {
1772 ret = write_sha1_file(buf, size, type, sha1);
1774 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1781 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1783 unsigned long size = st->st_size;
1786 unsigned char hdr[50];
1791 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1793 if (buf == MAP_FAILED)
1799 ret = write_sha1_file(buf, size, type, sha1);
1801 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1809 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1814 switch (st->st_mode & S_IFMT) {
1816 fd = open(path, O_RDONLY);
1818 return error("open(\"%s\"): %s", path,
1820 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1821 return error("%s: failed to insert into database",
1825 target = xmalloc(st->st_size+1);
1826 if (readlink(path, target, st->st_size+1) != st->st_size) {
1827 char *errstr = strerror(errno);
1829 return error("readlink(\"%s\"): %s", path,
1832 if (!write_object) {
1833 unsigned char hdr[50];
1835 write_sha1_file_prepare(target, st->st_size, blob_type,
1836 sha1, hdr, &hdrlen);
1837 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1838 return error("%s: failed to insert into database",
1843 return error("%s: unsupported file type", path);