2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
16 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
17 #define O_NOATIME 01000000
23 const unsigned char null_sha1[20] = { 0, };
25 static unsigned int sha1_file_open_flag = O_NOATIME;
27 static unsigned hexval(char c)
29 if (c >= '0' && c <= '9')
31 if (c >= 'a' && c <= 'f')
33 if (c >= 'A' && c <= 'F')
38 int get_sha1_hex(const char *hex, unsigned char *sha1)
41 for (i = 0; i < 20; i++) {
42 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
51 int adjust_shared_perm(const char *path)
56 if (!shared_repository)
58 if (lstat(path, &st) < 0)
69 if (chmod(path, mode) < 0)
74 int safe_create_leading_directories(char *path)
81 pos = strchr(pos, '/');
85 if (mkdir(path, 0777) < 0) {
86 if (errno != EEXIST) {
91 else if (adjust_shared_perm(path)) {
100 char * sha1_to_hex(const unsigned char *sha1)
102 static char buffer[50];
103 static const char hex[] = "0123456789abcdef";
107 for (i = 0; i < 20; i++) {
108 unsigned int val = *sha1++;
109 *buf++ = hex[val >> 4];
110 *buf++ = hex[val & 0xf];
117 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
120 for (i = 0; i < 20; i++) {
121 static char hex[] = "0123456789abcdef";
122 unsigned int val = sha1[i];
123 char *pos = pathbuf + i*2 + (i > 0);
124 *pos++ = hex[val >> 4];
125 *pos = hex[val & 0xf];
130 * NOTE! This returns a statically allocated buffer, so you have to be
131 * careful about using it. Do a "strdup()" if you need to save the
134 * Also note that this returns the location for creating. Reading
135 * SHA1 file can happen from any alternate directory listed in the
136 * DB_ENVIRONMENT environment variable if it is not found in
137 * the primary object database.
139 char *sha1_file_name(const unsigned char *sha1)
141 static char *name, *base;
144 const char *sha1_file_directory = get_object_directory();
145 int len = strlen(sha1_file_directory);
146 base = xmalloc(len + 60);
147 memcpy(base, sha1_file_directory, len);
148 memset(base+len, 0, 60);
151 name = base + len + 1;
153 fill_sha1_path(name, sha1);
157 char *sha1_pack_name(const unsigned char *sha1)
159 static const char hex[] = "0123456789abcdef";
160 static char *name, *base, *buf;
164 const char *sha1_file_directory = get_object_directory();
165 int len = strlen(sha1_file_directory);
166 base = xmalloc(len + 60);
167 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
168 name = base + len + 11;
173 for (i = 0; i < 20; i++) {
174 unsigned int val = *sha1++;
175 *buf++ = hex[val >> 4];
176 *buf++ = hex[val & 0xf];
182 char *sha1_pack_index_name(const unsigned char *sha1)
184 static const char hex[] = "0123456789abcdef";
185 static char *name, *base, *buf;
189 const char *sha1_file_directory = get_object_directory();
190 int len = strlen(sha1_file_directory);
191 base = xmalloc(len + 60);
192 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
193 name = base + len + 11;
198 for (i = 0; i < 20; i++) {
199 unsigned int val = *sha1++;
200 *buf++ = hex[val >> 4];
201 *buf++ = hex[val & 0xf];
207 struct alternate_object_database *alt_odb_list;
208 static struct alternate_object_database **alt_odb_tail;
211 * Prepare alternate object database registry.
213 * The variable alt_odb_list points at the list of struct
214 * alternate_object_database. The elements on this list come from
215 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
216 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
217 * whose contents is similar to that environment variable but can be
218 * LF separated. Its base points at a statically allocated buffer that
219 * contains "/the/directory/corresponding/to/.git/objects/...", while
220 * its name points just after the slash at the end of ".git/objects/"
221 * in the example above, and has enough space to hold 40-byte hex
222 * SHA1, an extra slash for the first level indirection, and the
225 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
226 const char *relative_base)
228 const char *cp, *last;
229 struct alternate_object_database *ent;
230 const char *objdir = get_object_directory();
236 if (cp < ep && *cp == '#') {
237 while (cp < ep && *cp != sep)
242 for ( ; cp < ep && *cp != sep; cp++)
245 struct alternate_object_database *alt;
246 /* 43 = 40-byte + 2 '/' + terminating NUL */
247 int pfxlen = cp - last;
248 int entlen = pfxlen + 43;
250 if (*last != '/' && relative_base) {
251 /* Relative alt-odb */
253 base_len = strlen(relative_base) + 1;
257 ent = xmalloc(sizeof(*ent) + entlen);
259 if (*last != '/' && relative_base) {
260 memcpy(ent->base, relative_base, base_len - 1);
261 ent->base[base_len - 1] = '/';
262 memcpy(ent->base + base_len,
266 memcpy(ent->base, last, pfxlen);
267 ent->name = ent->base + pfxlen + 1;
268 ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
269 ent->base[entlen-1] = 0;
271 /* Prevent the common mistake of listing the same
272 * thing twice, or object directory itself.
274 for (alt = alt_odb_list; alt; alt = alt->next)
275 if (!memcmp(ent->base, alt->base, pfxlen))
277 if (!memcmp(ent->base, objdir, pfxlen)) {
283 alt_odb_tail = &(ent->next);
287 while (cp < ep && *cp == sep)
293 void prepare_alt_odb(void)
301 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
306 alt_odb_tail = &alt_odb_list;
307 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL);
309 sprintf(path, "%s/info/alternates", get_object_directory());
310 fd = open(path, O_RDONLY);
313 if (fstat(fd, &st) || (st.st_size == 0)) {
317 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
319 if (map == MAP_FAILED)
322 link_alt_odb_entries(map, map + st.st_size, '\n',
323 get_object_directory());
324 munmap(map, st.st_size);
327 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
329 char *name = sha1_file_name(sha1);
330 struct alternate_object_database *alt;
335 for (alt = alt_odb_list; alt; alt = alt->next) {
337 fill_sha1_path(name, sha1);
338 if (!stat(alt->base, st))
344 #define PACK_MAX_SZ (1<<26)
345 static int pack_used_ctr;
346 static unsigned long pack_mapped;
347 struct packed_git *packed_git;
349 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
354 unsigned long idx_size;
356 int fd = open(path, O_RDONLY);
360 if (fstat(fd, &st)) {
364 idx_size = st.st_size;
365 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
367 if (idx_map == MAP_FAILED)
372 *idx_size_ = idx_size;
374 /* check index map */
375 if (idx_size < 4*256 + 20 + 20)
376 return error("index file too small");
378 for (i = 0; i < 256; i++) {
379 unsigned int n = ntohl(index[i]);
381 return error("non-monotonic index");
387 * - 256 index entries 4 bytes each
388 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
389 * - 20-byte SHA1 of the packfile
390 * - 20-byte SHA1 file checksum
392 if (idx_size != 4*256 + nr * 24 + 20 + 20)
393 return error("wrong index file size");
398 static int unuse_one_packed_git(void)
400 struct packed_git *p, *lru = NULL;
402 for (p = packed_git; p; p = p->next) {
403 if (p->pack_use_cnt || !p->pack_base)
405 if (!lru || p->pack_last_used < lru->pack_last_used)
410 munmap(lru->pack_base, lru->pack_size);
411 lru->pack_base = NULL;
415 void unuse_packed_git(struct packed_git *p)
420 int use_packed_git(struct packed_git *p)
424 // We created the struct before we had the pack
425 stat(p->pack_name, &st);
426 if (!S_ISREG(st.st_mode))
427 die("packfile %s not a regular file", p->pack_name);
428 p->pack_size = st.st_size;
435 pack_mapped += p->pack_size;
436 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
438 fd = open(p->pack_name, O_RDONLY);
440 die("packfile %s cannot be opened", p->pack_name);
441 if (fstat(fd, &st)) {
443 die("packfile %s cannot be opened", p->pack_name);
445 if (st.st_size != p->pack_size)
446 die("packfile %s size mismatch.", p->pack_name);
447 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
449 if (map == MAP_FAILED)
450 die("packfile %s cannot be mapped.", p->pack_name);
453 /* Check if the pack file matches with the index file.
456 if (memcmp((char*)(p->index_base) + p->index_size - 40,
457 p->pack_base + p->pack_size - 20, 20)) {
459 die("packfile %s does not match index.", p->pack_name);
462 p->pack_last_used = pack_used_ctr++;
467 struct packed_git *add_packed_git(char *path, int path_len, int local)
470 struct packed_git *p;
471 unsigned long idx_size;
473 unsigned char sha1[20];
475 if (check_packed_git_idx(path, &idx_size, &idx_map))
478 /* do we have a corresponding .pack file? */
479 strcpy(path + path_len - 4, ".pack");
480 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
481 munmap(idx_map, idx_size);
484 /* ok, it looks sane as far as we can check without
485 * actually mapping the pack file.
487 p = xmalloc(sizeof(*p) + path_len + 2);
488 strcpy(p->pack_name, path);
489 p->index_size = idx_size;
490 p->pack_size = st.st_size;
491 p->index_base = idx_map;
494 p->pack_last_used = 0;
496 p->pack_local = local;
497 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
498 memcpy(p->sha1, sha1, 20);
502 struct packed_git *parse_pack_index(unsigned char *sha1)
504 char *path = sha1_pack_index_name(sha1);
505 return parse_pack_index_file(sha1, path);
508 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
510 struct packed_git *p;
511 unsigned long idx_size;
515 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
518 path = sha1_pack_name(sha1);
520 p = xmalloc(sizeof(*p) + strlen(path) + 2);
521 strcpy(p->pack_name, path);
522 p->index_size = idx_size;
524 p->index_base = idx_map;
527 p->pack_last_used = 0;
529 memcpy(p->sha1, sha1, 20);
533 void install_packed_git(struct packed_git *pack)
535 pack->next = packed_git;
539 static void prepare_packed_git_one(char *objdir, int local)
546 sprintf(path, "%s/pack", objdir);
552 while ((de = readdir(dir)) != NULL) {
553 int namelen = strlen(de->d_name);
554 struct packed_git *p;
556 if (strcmp(de->d_name + namelen - 4, ".idx"))
559 /* we have .idx. Is it a file we can map? */
560 strcpy(path + len, de->d_name);
561 p = add_packed_git(path, len + namelen, local);
564 p->next = packed_git;
570 void prepare_packed_git(void)
572 static int run_once = 0;
573 struct alternate_object_database *alt;
577 prepare_packed_git_one(get_object_directory(), 1);
579 for (alt = alt_odb_list; alt; alt = alt->next) {
581 prepare_packed_git_one(alt->base, 0);
587 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
590 unsigned char real_sha1[20];
594 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
595 SHA1_Update(&c, map, size);
596 SHA1_Final(real_sha1, &c);
597 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
600 static void *map_sha1_file_internal(const unsigned char *sha1,
606 char *filename = find_sha1_file(sha1, &st);
612 fd = open(filename, O_RDONLY | sha1_file_open_flag);
614 /* See if it works without O_NOATIME */
615 switch (sha1_file_open_flag) {
617 fd = open(filename, O_RDONLY);
625 /* If it failed once, it will probably fail again.
626 * Stop using O_NOATIME
628 sha1_file_open_flag = 0;
630 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
632 if (map == MAP_FAILED)
638 int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
640 /* Get the data stream */
641 memset(stream, 0, sizeof(*stream));
642 stream->next_in = map;
643 stream->avail_in = mapsize;
644 stream->next_out = buffer;
645 stream->avail_out = size;
648 return inflate(stream, 0);
651 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
653 int bytes = strlen(buffer) + 1;
654 unsigned char *buf = xmalloc(1+size);
656 memcpy(buf, buffer + bytes, stream->total_out - bytes);
657 bytes = stream->total_out - bytes;
659 stream->next_out = buf + bytes;
660 stream->avail_out = size - bytes;
661 while (inflate(stream, Z_FINISH) == Z_OK)
670 * We used to just use "sscanf()", but that's actually way
671 * too permissive for what we want to check. So do an anal
672 * object header parse by hand.
674 int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
680 * The type can be at most ten bytes (including the
681 * terminating '\0' that we add), and is followed by
696 * The length must follow immediately, and be in canonical
697 * decimal format (ie "010" is not valid).
704 unsigned long c = *hdr - '0';
708 size = size * 10 + c;
714 * The length must be followed by a zero byte
716 return *hdr ? -1 : 0;
719 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
725 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
726 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
729 return unpack_sha1_rest(&stream, hdr, *size);
732 /* forward declaration for a mutually recursive function */
733 static int packed_object_info(struct pack_entry *entry,
734 char *type, unsigned long *sizep);
736 static int packed_delta_info(unsigned char *base_sha1,
737 unsigned long delta_size,
740 unsigned long *sizep,
741 struct packed_git *p)
743 struct pack_entry base_ent;
746 die("truncated pack file");
748 /* The base entry _must_ be in the same pack */
749 if (!find_pack_entry_one(base_sha1, &base_ent, p))
750 die("failed to find delta-pack base object %s",
751 sha1_to_hex(base_sha1));
753 /* We choose to only get the type of the base object and
754 * ignore potentially corrupt pack file that expects the delta
755 * based on a base with a wrong size. This saves tons of
759 if (packed_object_info(&base_ent, type, NULL))
760 die("cannot get info for delta-pack base");
763 const unsigned char *data;
764 unsigned char delta_head[64];
765 unsigned long result_size;
769 memset(&stream, 0, sizeof(stream));
771 data = stream.next_in = base_sha1 + 20;
772 stream.avail_in = left - 20;
773 stream.next_out = delta_head;
774 stream.avail_out = sizeof(delta_head);
776 inflateInit(&stream);
777 st = inflate(&stream, Z_FINISH);
779 if ((st != Z_STREAM_END) &&
780 stream.total_out != sizeof(delta_head))
781 die("delta data unpack-initial failed");
783 /* Examine the initial part of the delta to figure out
787 get_delta_hdr_size(&data); /* ignore base size */
789 /* Read the result size */
790 result_size = get_delta_hdr_size(&data);
791 *sizep = result_size;
796 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
797 enum object_type *type, unsigned long *sizep)
800 unsigned char *pack, c;
803 if (offset >= p->pack_size)
804 die("object offset outside of pack file");
806 pack = p->pack_base + offset;
809 *type = (c >> 4) & 7;
813 if (offset >= p->pack_size)
814 die("object offset outside of pack file");
817 size += (c & 0x7f) << shift;
824 void packed_object_info_detail(struct pack_entry *e,
827 unsigned long *store_size,
828 int *delta_chain_length,
829 unsigned char *base_sha1)
831 struct packed_git *p = e->p;
832 unsigned long offset, left;
834 enum object_type kind;
836 offset = unpack_object_header(p, e->offset, &kind, size);
837 pack = p->pack_base + offset;
838 left = p->pack_size - offset;
839 if (kind != OBJ_DELTA)
840 *delta_chain_length = 0;
842 int chain_length = 0;
843 memcpy(base_sha1, pack, 20);
845 struct pack_entry base_ent;
848 find_pack_entry_one(pack, &base_ent, p);
849 offset = unpack_object_header(p, base_ent.offset,
851 pack = p->pack_base + offset;
853 } while (kind == OBJ_DELTA);
854 *delta_chain_length = chain_length;
858 strcpy(type, "commit");
861 strcpy(type, "tree");
864 strcpy(type, "blob");
870 die("corrupted pack file %s containing object of kind %d",
873 *store_size = 0; /* notyet */
876 static int packed_object_info(struct pack_entry *entry,
877 char *type, unsigned long *sizep)
879 struct packed_git *p = entry->p;
880 unsigned long offset, size, left;
882 enum object_type kind;
885 if (use_packed_git(p))
886 die("cannot map packed file");
888 offset = unpack_object_header(p, entry->offset, &kind, &size);
889 pack = p->pack_base + offset;
890 left = p->pack_size - offset;
894 retval = packed_delta_info(pack, size, left, type, sizep, p);
898 strcpy(type, "commit");
901 strcpy(type, "tree");
904 strcpy(type, "blob");
910 die("corrupted pack file %s containing object of kind %d",
919 /* forward declaration for a mutually recursive function */
920 static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
922 static void *unpack_delta_entry(unsigned char *base_sha1,
923 unsigned long delta_size,
926 unsigned long *sizep,
927 struct packed_git *p)
929 struct pack_entry base_ent;
930 void *data, *delta_data, *result, *base;
931 unsigned long data_size, result_size, base_size;
936 die("truncated pack file");
937 data = base_sha1 + 20;
938 data_size = left - 20;
939 delta_data = xmalloc(delta_size);
941 memset(&stream, 0, sizeof(stream));
943 stream.next_in = data;
944 stream.avail_in = data_size;
945 stream.next_out = delta_data;
946 stream.avail_out = delta_size;
948 inflateInit(&stream);
949 st = inflate(&stream, Z_FINISH);
951 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
952 die("delta data unpack failed");
954 /* The base entry _must_ be in the same pack */
955 if (!find_pack_entry_one(base_sha1, &base_ent, p))
956 die("failed to find delta-pack base object %s",
957 sha1_to_hex(base_sha1));
958 base = unpack_entry_gently(&base_ent, type, &base_size);
960 die("failed to read delta-pack base object %s",
961 sha1_to_hex(base_sha1));
962 result = patch_delta(base, base_size,
963 delta_data, delta_size,
966 die("failed to apply delta");
969 *sizep = result_size;
973 static void *unpack_non_delta_entry(unsigned char *data,
979 unsigned char *buffer;
981 buffer = xmalloc(size + 1);
983 memset(&stream, 0, sizeof(stream));
984 stream.next_in = data;
985 stream.avail_in = left;
986 stream.next_out = buffer;
987 stream.avail_out = size;
989 inflateInit(&stream);
990 st = inflate(&stream, Z_FINISH);
992 if ((st != Z_STREAM_END) || stream.total_out != size) {
1000 static void *unpack_entry(struct pack_entry *entry,
1001 char *type, unsigned long *sizep)
1003 struct packed_git *p = entry->p;
1006 if (use_packed_git(p))
1007 die("cannot map packed file");
1008 retval = unpack_entry_gently(entry, type, sizep);
1009 unuse_packed_git(p);
1011 die("corrupted pack file %s", p->pack_name);
1015 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1016 void *unpack_entry_gently(struct pack_entry *entry,
1017 char *type, unsigned long *sizep)
1019 struct packed_git *p = entry->p;
1020 unsigned long offset, size, left;
1021 unsigned char *pack;
1022 enum object_type kind;
1025 offset = unpack_object_header(p, entry->offset, &kind, &size);
1026 pack = p->pack_base + offset;
1027 left = p->pack_size - offset;
1030 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
1033 strcpy(type, "commit");
1036 strcpy(type, "tree");
1039 strcpy(type, "blob");
1042 strcpy(type, "tag");
1048 retval = unpack_non_delta_entry(pack, size, left);
1052 int num_packed_objects(const struct packed_git *p)
1054 /* See check_packed_git_idx() */
1055 return (p->index_size - 20 - 20 - 4*256) / 24;
1058 int nth_packed_object_sha1(const struct packed_git *p, int n,
1059 unsigned char* sha1)
1061 void *index = p->index_base + 256;
1062 if (n < 0 || num_packed_objects(p) <= n)
1064 memcpy(sha1, (index + 24 * n + 4), 20);
1068 int find_pack_entry_one(const unsigned char *sha1,
1069 struct pack_entry *e, struct packed_git *p)
1071 unsigned int *level1_ofs = p->index_base;
1072 int hi = ntohl(level1_ofs[*sha1]);
1073 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1074 void *index = p->index_base + 256;
1077 int mi = (lo + hi) / 2;
1078 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
1080 e->offset = ntohl(*((int*)(index + 24 * mi)));
1081 memcpy(e->sha1, sha1, 20);
1093 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1095 struct packed_git *p;
1096 prepare_packed_git();
1098 for (p = packed_git; p; p = p->next) {
1099 if (find_pack_entry_one(sha1, e, p))
1105 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1106 struct packed_git *packs)
1108 struct packed_git *p;
1109 struct pack_entry e;
1111 for (p = packs; p; p = p->next) {
1112 if (find_pack_entry_one(sha1, &e, p))
1119 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1122 unsigned long mapsize, size;
1127 map = map_sha1_file_internal(sha1, &mapsize);
1129 struct pack_entry e;
1131 if (!find_pack_entry(sha1, &e))
1132 return error("unable to find %s", sha1_to_hex(sha1));
1133 return packed_object_info(&e, type, sizep);
1135 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1136 status = error("unable to unpack %s header",
1138 if (parse_sha1_header(hdr, type, &size) < 0)
1139 status = error("unable to parse %s header", sha1_to_hex(sha1));
1145 inflateEnd(&stream);
1146 munmap(map, mapsize);
1150 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1152 struct pack_entry e;
1154 if (!find_pack_entry(sha1, &e)) {
1155 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1158 return unpack_entry(&e, type, size);
1161 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1163 unsigned long mapsize;
1165 struct pack_entry e;
1167 if (find_pack_entry(sha1, &e))
1168 return read_packed_sha1(sha1, type, size);
1169 map = map_sha1_file_internal(sha1, &mapsize);
1171 buf = unpack_sha1_file(map, mapsize, type, size);
1172 munmap(map, mapsize);
1178 void *read_object_with_reference(const unsigned char *sha1,
1179 const char *required_type,
1180 unsigned long *size,
1181 unsigned char *actual_sha1_return)
1185 unsigned long isize;
1186 unsigned char actual_sha1[20];
1188 memcpy(actual_sha1, sha1, 20);
1190 int ref_length = -1;
1191 const char *ref_type = NULL;
1193 buffer = read_sha1_file(actual_sha1, type, &isize);
1196 if (!strcmp(type, required_type)) {
1198 if (actual_sha1_return)
1199 memcpy(actual_sha1_return, actual_sha1, 20);
1202 /* Handle references */
1203 else if (!strcmp(type, "commit"))
1205 else if (!strcmp(type, "tag"))
1206 ref_type = "object ";
1211 ref_length = strlen(ref_type);
1213 if (memcmp(buffer, ref_type, ref_length) ||
1214 get_sha1_hex(buffer + ref_length, actual_sha1)) {
1219 /* Now we have the ID of the referred-to object in
1220 * actual_sha1. Check again. */
1224 char *write_sha1_file_prepare(void *buf,
1227 unsigned char *sha1,
1233 /* Generate the header */
1234 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1238 SHA1_Update(&c, hdr, *hdrlen);
1239 SHA1_Update(&c, buf, len);
1240 SHA1_Final(sha1, &c);
1242 return sha1_file_name(sha1);
1246 * Link the tempfile to the final place, possibly creating the
1247 * last directory level as you do so.
1249 * Returns the errno on failure, 0 on success.
1251 static int link_temp_to_file(const char *tmpfile, char *filename)
1255 if (!link(tmpfile, filename))
1259 * Try to mkdir the last path component if that failed
1262 * Re-try the "link()" regardless of whether the mkdir
1263 * succeeds, since a race might mean that somebody
1267 if (ret == ENOENT) {
1268 char *dir = strrchr(filename, '/');
1271 mkdir(filename, 0777);
1272 if (adjust_shared_perm(filename))
1275 if (!link(tmpfile, filename))
1284 * Move the just written object into its final resting place
1286 int move_temp_to_file(const char *tmpfile, char *filename)
1288 int ret = link_temp_to_file(tmpfile, filename);
1291 * Coda hack - coda doesn't like cross-directory links,
1292 * so we fall back to a rename, which will mean that it
1293 * won't be able to check collisions, but that's not a
1296 * The same holds for FAT formatted media.
1298 * When this succeeds, we just return 0. We have nothing
1301 if (ret && ret != EEXIST) {
1302 if (!rename(tmpfile, filename))
1308 if (ret != EEXIST) {
1309 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1312 /* FIXME!!! Collision check here ? */
1318 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1321 unsigned char *compressed;
1323 unsigned char sha1[20];
1325 static char tmpfile[PATH_MAX];
1326 unsigned char hdr[50];
1329 /* Normally if we have it in the pack then we do not bother writing
1330 * it out into .git/objects/??/?{38} file.
1332 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1334 memcpy(returnsha1, sha1, 20);
1335 if (has_sha1_file(sha1))
1337 fd = open(filename, O_RDONLY);
1340 * FIXME!!! We might do collision checking here, but we'd
1341 * need to uncompress the old file and check it. Later.
1347 if (errno != ENOENT) {
1348 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1352 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1354 fd = mkstemp(tmpfile);
1356 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1361 memset(&stream, 0, sizeof(stream));
1362 deflateInit(&stream, Z_BEST_COMPRESSION);
1363 size = deflateBound(&stream, len+hdrlen);
1364 compressed = xmalloc(size);
1367 stream.next_out = compressed;
1368 stream.avail_out = size;
1370 /* First header.. */
1371 stream.next_in = hdr;
1372 stream.avail_in = hdrlen;
1373 while (deflate(&stream, 0) == Z_OK)
1376 /* Then the data itself.. */
1377 stream.next_in = buf;
1378 stream.avail_in = len;
1379 while (deflate(&stream, Z_FINISH) == Z_OK)
1381 deflateEnd(&stream);
1382 size = stream.total_out;
1384 if (write(fd, compressed, size) != size)
1385 die("unable to write file");
1390 return move_temp_to_file(tmpfile, filename);
1393 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1396 unsigned long objsize;
1398 void *map = map_sha1_file_internal(sha1, &objsize);
1400 void *temp_obj = NULL;
1404 unsigned char *unpacked;
1409 // need to unpack and recompress it by itself
1410 unpacked = read_packed_sha1(sha1, type, &len);
1412 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1415 memset(&stream, 0, sizeof(stream));
1416 deflateInit(&stream, Z_BEST_COMPRESSION);
1417 size = deflateBound(&stream, len + hdrlen);
1418 temp_obj = buf = xmalloc(size);
1421 stream.next_out = buf;
1422 stream.avail_out = size;
1424 /* First header.. */
1425 stream.next_in = (void *)hdr;
1426 stream.avail_in = hdrlen;
1427 while (deflate(&stream, 0) == Z_OK)
1430 /* Then the data itself.. */
1431 stream.next_in = unpacked;
1432 stream.avail_in = len;
1433 while (deflate(&stream, Z_FINISH) == Z_OK)
1435 deflateEnd(&stream);
1438 objsize = stream.total_out;
1442 size = write(fd, buf + posn, objsize - posn);
1445 fprintf(stderr, "write closed\n");
1452 } while (posn < objsize);
1455 munmap(map, objsize);
1462 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1463 size_t bufsize, size_t *bufposn)
1465 char tmpfile[PATH_MAX];
1468 unsigned char real_sha1[20];
1469 unsigned char discard[4096];
1473 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1475 local = mkstemp(tmpfile);
1477 return error("Couldn't open %s for %s\n", tmpfile, sha1_to_hex(sha1));
1479 memset(&stream, 0, sizeof(stream));
1481 inflateInit(&stream);
1488 stream.avail_in = *bufposn;
1489 stream.next_in = (unsigned char *) buffer;
1491 stream.next_out = discard;
1492 stream.avail_out = sizeof(discard);
1493 ret = inflate(&stream, Z_SYNC_FLUSH);
1494 SHA1_Update(&c, discard, sizeof(discard) -
1496 } while (stream.avail_in && ret == Z_OK);
1497 write(local, buffer, *bufposn - stream.avail_in);
1498 memmove(buffer, buffer + *bufposn - stream.avail_in,
1500 *bufposn = stream.avail_in;
1504 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1509 return error("Connection closed?");
1510 perror("Reading from connection");
1515 inflateEnd(&stream);
1518 SHA1_Final(real_sha1, &c);
1519 if (ret != Z_STREAM_END) {
1521 return error("File %s corrupted", sha1_to_hex(sha1));
1523 if (memcmp(sha1, real_sha1, 20)) {
1525 return error("File %s has bad hash\n", sha1_to_hex(sha1));
1528 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1531 int has_pack_index(const unsigned char *sha1)
1534 if (stat(sha1_pack_index_name(sha1), &st))
1539 int has_pack_file(const unsigned char *sha1)
1542 if (stat(sha1_pack_name(sha1), &st))
1547 int has_sha1_pack(const unsigned char *sha1)
1549 struct pack_entry e;
1550 return find_pack_entry(sha1, &e);
1553 int has_sha1_file(const unsigned char *sha1)
1556 struct pack_entry e;
1558 if (find_pack_entry(sha1, &e))
1560 return find_sha1_file(sha1, &st) ? 1 : 0;
1563 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1565 unsigned long size = 4096;
1566 char *buf = malloc(size);
1568 unsigned long off = 0;
1569 unsigned char hdr[50];
1572 iret = read(fd, buf + off, size - off);
1577 buf = realloc(buf, size);
1588 ret = write_sha1_file(buf, off, type, sha1);
1590 write_sha1_file_prepare(buf, off, type, sha1, hdr, &hdrlen);
1597 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1599 unsigned long size = st->st_size;
1602 unsigned char hdr[50];
1607 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1609 if (buf == MAP_FAILED)
1615 ret = write_sha1_file(buf, size, type, sha1);
1617 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1625 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1630 switch (st->st_mode & S_IFMT) {
1632 fd = open(path, O_RDONLY);
1634 return error("open(\"%s\"): %s", path,
1636 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1637 return error("%s: failed to insert into database",
1641 target = xmalloc(st->st_size+1);
1642 if (readlink(path, target, st->st_size+1) != st->st_size) {
1643 char *errstr = strerror(errno);
1645 return error("readlink(\"%s\"): %s", path,
1648 if (!write_object) {
1649 unsigned char hdr[50];
1651 write_sha1_file_prepare(target, st->st_size, "blob",
1652 sha1, hdr, &hdrlen);
1653 } else if (write_sha1_file(target, st->st_size, "blob", sha1))
1654 return error("%s: failed to insert into database",
1659 return error("%s: unsupported file type", path);