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 static unsigned int sha1_file_open_flag = O_NOATIME;
25 static unsigned hexval(char c)
27 if (c >= '0' && c <= '9')
29 if (c >= 'a' && c <= 'f')
31 if (c >= 'A' && c <= 'F')
36 int get_sha1_hex(const char *hex, unsigned char *sha1)
39 for (i = 0; i < 20; i++) {
40 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
49 static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir,
51 static void setup_git_env(void)
53 git_dir = getenv(GIT_DIR_ENVIRONMENT);
55 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
56 git_object_dir = getenv(DB_ENVIRONMENT);
57 if (!git_object_dir) {
58 git_object_dir = xmalloc(strlen(git_dir) + 9);
59 sprintf(git_object_dir, "%s/objects", git_dir);
61 git_refs_dir = xmalloc(strlen(git_dir) + 6);
62 sprintf(git_refs_dir, "%s/refs", git_dir);
63 git_index_file = getenv(INDEX_ENVIRONMENT);
64 if (!git_index_file) {
65 git_index_file = xmalloc(strlen(git_dir) + 7);
66 sprintf(git_index_file, "%s/index", git_dir);
68 git_graft_file = getenv(GRAFT_ENVIRONMENT);
70 git_graft_file = strdup(git_path("info/grafts"));
73 char *get_git_dir(void)
80 char *get_object_directory(void)
84 return git_object_dir;
87 char *get_refs_directory(void)
94 char *get_index_file(void)
98 return git_index_file;
101 char *get_graft_file(void)
105 return git_graft_file;
108 int safe_create_leading_directories(char *path)
113 pos = strchr(pos, '/');
117 if (mkdir(path, 0777) < 0)
118 if (errno != EEXIST) {
127 char * sha1_to_hex(const unsigned char *sha1)
129 static char buffer[50];
130 static const char hex[] = "0123456789abcdef";
134 for (i = 0; i < 20; i++) {
135 unsigned int val = *sha1++;
136 *buf++ = hex[val >> 4];
137 *buf++ = hex[val & 0xf];
142 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
145 for (i = 0; i < 20; i++) {
146 static char hex[] = "0123456789abcdef";
147 unsigned int val = sha1[i];
148 char *pos = pathbuf + i*2 + (i > 0);
149 *pos++ = hex[val >> 4];
150 *pos = hex[val & 0xf];
155 * NOTE! This returns a statically allocated buffer, so you have to be
156 * careful about using it. Do a "strdup()" if you need to save the
159 * Also note that this returns the location for creating. Reading
160 * SHA1 file can happen from any alternate directory listed in the
161 * DB_ENVIRONMENT environment variable if it is not found in
162 * the primary object database.
164 char *sha1_file_name(const unsigned char *sha1)
166 static char *name, *base;
169 const char *sha1_file_directory = get_object_directory();
170 int len = strlen(sha1_file_directory);
171 base = xmalloc(len + 60);
172 memcpy(base, sha1_file_directory, len);
173 memset(base+len, 0, 60);
176 name = base + len + 1;
178 fill_sha1_path(name, sha1);
182 char *sha1_pack_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.pack", 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 char *sha1_pack_index_name(const unsigned char *sha1)
209 static const char hex[] = "0123456789abcdef";
210 static char *name, *base, *buf;
214 const char *sha1_file_directory = get_object_directory();
215 int len = strlen(sha1_file_directory);
216 base = xmalloc(len + 60);
217 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
218 name = base + len + 11;
223 for (i = 0; i < 20; i++) {
224 unsigned int val = *sha1++;
225 *buf++ = hex[val >> 4];
226 *buf++ = hex[val & 0xf];
232 struct alternate_object_database *alt_odb_list;
233 static struct alternate_object_database **alt_odb_tail;
236 * Prepare alternate object database registry.
238 * The variable alt_odb_list points at the list of struct
239 * alternate_object_database. The elements on this list come from
240 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
241 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
242 * whose contents is exactly in the same format as that environment
243 * variable. Its base points at a statically allocated buffer that
244 * contains "/the/directory/corresponding/to/.git/objects/...", while
245 * its name points just after the slash at the end of ".git/objects/"
246 * in the example above, and has enough space to hold 40-byte hex
247 * SHA1, an extra slash for the first level indirection, and the
250 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
251 const char *relative_base)
253 const char *cp, *last;
254 struct alternate_object_database *ent;
260 if (cp < ep && *cp == '#') {
261 while (cp < ep && *cp != sep)
266 for ( ; cp < ep && *cp != sep; cp++)
269 /* 43 = 40-byte + 2 '/' + terminating NUL */
270 int pfxlen = cp - last;
271 int entlen = pfxlen + 43;
273 if (*last != '/' && relative_base) {
274 /* Relative alt-odb */
276 base_len = strlen(relative_base) + 1;
280 ent = xmalloc(sizeof(*ent) + entlen);
282 alt_odb_tail = &(ent->next);
284 if (*last != '/' && relative_base) {
285 memcpy(ent->base, relative_base, base_len - 1);
286 ent->base[base_len - 1] = '/';
287 memcpy(ent->base + base_len,
291 memcpy(ent->base, last, pfxlen);
292 ent->name = ent->base + pfxlen + 1;
293 ent->base[pfxlen] = ent->base[pfxlen + 3] = '/';
294 ent->base[entlen-1] = 0;
296 while (cp < ep && *cp == sep)
302 void prepare_alt_odb(void)
310 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
315 alt_odb_tail = &alt_odb_list;
316 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL);
318 sprintf(path, "%s/info/alternates", get_object_directory());
319 fd = open(path, O_RDONLY);
322 if (fstat(fd, &st) || (st.st_size == 0)) {
326 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
328 if (map == MAP_FAILED)
331 link_alt_odb_entries(map, map + st.st_size, '\n',
332 get_object_directory());
333 munmap(map, st.st_size);
336 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
338 char *name = sha1_file_name(sha1);
339 struct alternate_object_database *alt;
344 for (alt = alt_odb_list; alt; alt = alt->next) {
346 fill_sha1_path(name, sha1);
347 if (!stat(alt->base, st))
353 #define PACK_MAX_SZ (1<<26)
354 static int pack_used_ctr;
355 static unsigned long pack_mapped;
356 struct packed_git *packed_git;
358 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
363 unsigned long idx_size;
365 int fd = open(path, O_RDONLY);
369 if (fstat(fd, &st)) {
373 idx_size = st.st_size;
374 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
376 if (idx_map == MAP_FAILED)
381 *idx_size_ = idx_size;
383 /* check index map */
384 if (idx_size < 4*256 + 20 + 20)
385 return error("index file too small");
387 for (i = 0; i < 256; i++) {
388 unsigned int n = ntohl(index[i]);
390 return error("non-monotonic index");
396 * - 256 index entries 4 bytes each
397 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
398 * - 20-byte SHA1 of the packfile
399 * - 20-byte SHA1 file checksum
401 if (idx_size != 4*256 + nr * 24 + 20 + 20)
402 return error("wrong index file size");
407 static int unuse_one_packed_git(void)
409 struct packed_git *p, *lru = NULL;
411 for (p = packed_git; p; p = p->next) {
412 if (p->pack_use_cnt || !p->pack_base)
414 if (!lru || p->pack_last_used < lru->pack_last_used)
419 munmap(lru->pack_base, lru->pack_size);
420 lru->pack_base = NULL;
424 void unuse_packed_git(struct packed_git *p)
429 int use_packed_git(struct packed_git *p)
433 // We created the struct before we had the pack
434 stat(p->pack_name, &st);
435 if (!S_ISREG(st.st_mode))
436 die("packfile %s not a regular file", p->pack_name);
437 p->pack_size = st.st_size;
444 pack_mapped += p->pack_size;
445 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
447 fd = open(p->pack_name, O_RDONLY);
449 die("packfile %s cannot be opened", p->pack_name);
450 if (fstat(fd, &st)) {
452 die("packfile %s cannot be opened", p->pack_name);
454 if (st.st_size != p->pack_size)
455 die("packfile %s size mismatch.", p->pack_name);
456 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
458 if (map == MAP_FAILED)
459 die("packfile %s cannot be mapped.", p->pack_name);
462 /* Check if the pack file matches with the index file.
465 if (memcmp((char*)(p->index_base) + p->index_size - 40,
466 p->pack_base + p->pack_size - 20, 20)) {
468 die("packfile %s does not match index.", p->pack_name);
471 p->pack_last_used = pack_used_ctr++;
476 struct packed_git *add_packed_git(char *path, int path_len)
479 struct packed_git *p;
480 unsigned long idx_size;
483 if (check_packed_git_idx(path, &idx_size, &idx_map))
486 /* do we have a corresponding .pack file? */
487 strcpy(path + path_len - 4, ".pack");
488 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
489 munmap(idx_map, idx_size);
492 /* ok, it looks sane as far as we can check without
493 * actually mapping the pack file.
495 p = xmalloc(sizeof(*p) + path_len + 2);
496 strcpy(p->pack_name, path);
497 p->index_size = idx_size;
498 p->pack_size = st.st_size;
499 p->index_base = idx_map;
502 p->pack_last_used = 0;
507 struct packed_git *parse_pack_index(unsigned char *sha1)
509 char *path = sha1_pack_index_name(sha1);
510 return parse_pack_index_file(sha1, path);
513 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
515 struct packed_git *p;
516 unsigned long idx_size;
520 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
523 path = sha1_pack_name(sha1);
525 p = xmalloc(sizeof(*p) + strlen(path) + 2);
526 strcpy(p->pack_name, path);
527 p->index_size = idx_size;
529 p->index_base = idx_map;
532 p->pack_last_used = 0;
534 memcpy(p->sha1, sha1, 20);
538 void install_packed_git(struct packed_git *pack)
540 pack->next = packed_git;
544 static void prepare_packed_git_one(char *objdir)
551 sprintf(path, "%s/pack", objdir);
557 while ((de = readdir(dir)) != NULL) {
558 int namelen = strlen(de->d_name);
559 struct packed_git *p;
561 if (strcmp(de->d_name + namelen - 4, ".idx"))
564 /* we have .idx. Is it a file we can map? */
565 strcpy(path + len, de->d_name);
566 p = add_packed_git(path, len + namelen);
569 p->next = packed_git;
575 void prepare_packed_git(void)
577 static int run_once = 0;
578 struct alternate_object_database *alt;
582 prepare_packed_git_one(get_object_directory());
584 for (alt = alt_odb_list; alt; alt = alt->next) {
586 prepare_packed_git_one(alt->base);
591 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
594 unsigned char real_sha1[20];
598 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
599 SHA1_Update(&c, map, size);
600 SHA1_Final(real_sha1, &c);
601 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
604 static void *map_sha1_file_internal(const unsigned char *sha1,
610 char *filename = find_sha1_file(sha1, &st);
616 fd = open(filename, O_RDONLY | sha1_file_open_flag);
618 /* See if it works without O_NOATIME */
619 switch (sha1_file_open_flag) {
621 fd = open(filename, O_RDONLY);
629 /* If it failed once, it will probably fail again.
630 * Stop using O_NOATIME
632 sha1_file_open_flag = 0;
634 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
636 if (map == MAP_FAILED)
642 int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
644 /* Get the data stream */
645 memset(stream, 0, sizeof(*stream));
646 stream->next_in = map;
647 stream->avail_in = mapsize;
648 stream->next_out = buffer;
649 stream->avail_out = size;
652 return inflate(stream, 0);
655 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
657 int bytes = strlen(buffer) + 1;
658 unsigned char *buf = xmalloc(1+size);
660 memcpy(buf, buffer + bytes, stream->total_out - bytes);
661 bytes = stream->total_out - bytes;
663 stream->next_out = buf + bytes;
664 stream->avail_out = size - bytes;
665 while (inflate(stream, Z_FINISH) == Z_OK)
674 * We used to just use "sscanf()", but that's actually way
675 * too permissive for what we want to check. So do an anal
676 * object header parse by hand.
678 int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
684 * The type can be at most ten bytes (including the
685 * terminating '\0' that we add), and is followed by
700 * The length must follow immediately, and be in canonical
701 * decimal format (ie "010" is not valid).
708 unsigned long c = *hdr - '0';
712 size = size * 10 + c;
718 * The length must be followed by a zero byte
720 return *hdr ? -1 : 0;
723 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
729 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
730 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
733 return unpack_sha1_rest(&stream, hdr, *size);
736 /* forward declaration for a mutually recursive function */
737 static int packed_object_info(struct pack_entry *entry,
738 char *type, unsigned long *sizep);
740 static int packed_delta_info(unsigned char *base_sha1,
741 unsigned long delta_size,
744 unsigned long *sizep,
745 struct packed_git *p)
747 struct pack_entry base_ent;
750 die("truncated pack file");
752 /* The base entry _must_ be in the same pack */
753 if (!find_pack_entry_one(base_sha1, &base_ent, p))
754 die("failed to find delta-pack base object %s",
755 sha1_to_hex(base_sha1));
757 /* We choose to only get the type of the base object and
758 * ignore potentially corrupt pack file that expects the delta
759 * based on a base with a wrong size. This saves tons of
763 if (packed_object_info(&base_ent, type, NULL))
764 die("cannot get info for delta-pack base");
767 const unsigned char *data;
768 unsigned char delta_head[64];
769 unsigned long result_size;
773 memset(&stream, 0, sizeof(stream));
775 data = stream.next_in = base_sha1 + 20;
776 stream.avail_in = left - 20;
777 stream.next_out = delta_head;
778 stream.avail_out = sizeof(delta_head);
780 inflateInit(&stream);
781 st = inflate(&stream, Z_FINISH);
783 if ((st != Z_STREAM_END) &&
784 stream.total_out != sizeof(delta_head))
785 die("delta data unpack-initial failed");
787 /* Examine the initial part of the delta to figure out
791 get_delta_hdr_size(&data); /* ignore base size */
793 /* Read the result size */
794 result_size = get_delta_hdr_size(&data);
795 *sizep = result_size;
800 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
801 enum object_type *type, unsigned long *sizep)
804 unsigned char *pack, c;
807 if (offset >= p->pack_size)
808 die("object offset outside of pack file");
810 pack = p->pack_base + offset;
813 *type = (c >> 4) & 7;
817 if (offset >= p->pack_size)
818 die("object offset outside of pack file");
821 size += (c & 0x7f) << shift;
828 void packed_object_info_detail(struct pack_entry *e,
831 unsigned long *store_size,
832 int *delta_chain_length,
833 unsigned char *base_sha1)
835 struct packed_git *p = e->p;
836 unsigned long offset, left;
838 enum object_type kind;
840 offset = unpack_object_header(p, e->offset, &kind, size);
841 pack = p->pack_base + offset;
842 left = p->pack_size - offset;
843 if (kind != OBJ_DELTA)
844 *delta_chain_length = 0;
846 int chain_length = 0;
847 memcpy(base_sha1, pack, 20);
849 struct pack_entry base_ent;
852 find_pack_entry_one(pack, &base_ent, p);
853 offset = unpack_object_header(p, base_ent.offset,
855 pack = p->pack_base + offset;
857 } while (kind == OBJ_DELTA);
858 *delta_chain_length = chain_length;
862 strcpy(type, "commit");
865 strcpy(type, "tree");
868 strcpy(type, "blob");
874 die("corrupted pack file %s containing object of kind %d",
877 *store_size = 0; /* notyet */
880 static int packed_object_info(struct pack_entry *entry,
881 char *type, unsigned long *sizep)
883 struct packed_git *p = entry->p;
884 unsigned long offset, size, left;
886 enum object_type kind;
889 if (use_packed_git(p))
890 die("cannot map packed file");
892 offset = unpack_object_header(p, entry->offset, &kind, &size);
893 pack = p->pack_base + offset;
894 left = p->pack_size - offset;
898 retval = packed_delta_info(pack, size, left, type, sizep, p);
902 strcpy(type, "commit");
905 strcpy(type, "tree");
908 strcpy(type, "blob");
914 die("corrupted pack file %s containing object of kind %d",
923 /* forward declaration for a mutually recursive function */
924 static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
926 static void *unpack_delta_entry(unsigned char *base_sha1,
927 unsigned long delta_size,
930 unsigned long *sizep,
931 struct packed_git *p)
933 struct pack_entry base_ent;
934 void *data, *delta_data, *result, *base;
935 unsigned long data_size, result_size, base_size;
940 die("truncated pack file");
941 data = base_sha1 + 20;
942 data_size = left - 20;
943 delta_data = xmalloc(delta_size);
945 memset(&stream, 0, sizeof(stream));
947 stream.next_in = data;
948 stream.avail_in = data_size;
949 stream.next_out = delta_data;
950 stream.avail_out = delta_size;
952 inflateInit(&stream);
953 st = inflate(&stream, Z_FINISH);
955 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
956 die("delta data unpack failed");
958 /* The base entry _must_ be in the same pack */
959 if (!find_pack_entry_one(base_sha1, &base_ent, p))
960 die("failed to find delta-pack base object %s",
961 sha1_to_hex(base_sha1));
962 base = unpack_entry_gently(&base_ent, type, &base_size);
964 die("failed to read delta-pack base object %s",
965 sha1_to_hex(base_sha1));
966 result = patch_delta(base, base_size,
967 delta_data, delta_size,
970 die("failed to apply delta");
973 *sizep = result_size;
977 static void *unpack_non_delta_entry(unsigned char *data,
983 unsigned char *buffer;
985 buffer = xmalloc(size + 1);
987 memset(&stream, 0, sizeof(stream));
988 stream.next_in = data;
989 stream.avail_in = left;
990 stream.next_out = buffer;
991 stream.avail_out = size;
993 inflateInit(&stream);
994 st = inflate(&stream, Z_FINISH);
996 if ((st != Z_STREAM_END) || stream.total_out != size) {
1004 static void *unpack_entry(struct pack_entry *entry,
1005 char *type, unsigned long *sizep)
1007 struct packed_git *p = entry->p;
1010 if (use_packed_git(p))
1011 die("cannot map packed file");
1012 retval = unpack_entry_gently(entry, type, sizep);
1013 unuse_packed_git(p);
1015 die("corrupted pack file %s", p->pack_name);
1019 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1020 void *unpack_entry_gently(struct pack_entry *entry,
1021 char *type, unsigned long *sizep)
1023 struct packed_git *p = entry->p;
1024 unsigned long offset, size, left;
1025 unsigned char *pack;
1026 enum object_type kind;
1029 offset = unpack_object_header(p, entry->offset, &kind, &size);
1030 pack = p->pack_base + offset;
1031 left = p->pack_size - offset;
1034 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
1037 strcpy(type, "commit");
1040 strcpy(type, "tree");
1043 strcpy(type, "blob");
1046 strcpy(type, "tag");
1052 retval = unpack_non_delta_entry(pack, size, left);
1056 int num_packed_objects(const struct packed_git *p)
1058 /* See check_packed_git_idx() */
1059 return (p->index_size - 20 - 20 - 4*256) / 24;
1062 int nth_packed_object_sha1(const struct packed_git *p, int n,
1063 unsigned char* sha1)
1065 void *index = p->index_base + 256;
1066 if (n < 0 || num_packed_objects(p) <= n)
1068 memcpy(sha1, (index + 24 * n + 4), 20);
1072 int find_pack_entry_one(const unsigned char *sha1,
1073 struct pack_entry *e, struct packed_git *p)
1075 unsigned int *level1_ofs = p->index_base;
1076 int hi = ntohl(level1_ofs[*sha1]);
1077 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1078 void *index = p->index_base + 256;
1081 int mi = (lo + hi) / 2;
1082 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
1084 e->offset = ntohl(*((int*)(index + 24 * mi)));
1085 memcpy(e->sha1, sha1, 20);
1097 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1099 struct packed_git *p;
1100 prepare_packed_git();
1102 for (p = packed_git; p; p = p->next) {
1103 if (find_pack_entry_one(sha1, e, p))
1109 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1110 struct packed_git *packs)
1112 struct packed_git *p;
1113 struct pack_entry e;
1115 for (p = packs; p; p = p->next) {
1116 if (find_pack_entry_one(sha1, &e, p))
1123 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1126 unsigned long mapsize, size;
1131 map = map_sha1_file_internal(sha1, &mapsize);
1133 struct pack_entry e;
1135 if (!find_pack_entry(sha1, &e))
1136 return error("unable to find %s", sha1_to_hex(sha1));
1137 return packed_object_info(&e, type, sizep);
1139 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1140 status = error("unable to unpack %s header",
1142 if (parse_sha1_header(hdr, type, &size) < 0)
1143 status = error("unable to parse %s header", sha1_to_hex(sha1));
1149 inflateEnd(&stream);
1150 munmap(map, mapsize);
1154 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1156 struct pack_entry e;
1158 if (!find_pack_entry(sha1, &e)) {
1159 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1162 return unpack_entry(&e, type, size);
1165 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1167 unsigned long mapsize;
1169 struct pack_entry e;
1171 if (find_pack_entry(sha1, &e))
1172 return read_packed_sha1(sha1, type, size);
1173 map = map_sha1_file_internal(sha1, &mapsize);
1175 buf = unpack_sha1_file(map, mapsize, type, size);
1176 munmap(map, mapsize);
1182 void *read_object_with_reference(const unsigned char *sha1,
1183 const char *required_type,
1184 unsigned long *size,
1185 unsigned char *actual_sha1_return)
1189 unsigned long isize;
1190 unsigned char actual_sha1[20];
1192 memcpy(actual_sha1, sha1, 20);
1194 int ref_length = -1;
1195 const char *ref_type = NULL;
1197 buffer = read_sha1_file(actual_sha1, type, &isize);
1200 if (!strcmp(type, required_type)) {
1202 if (actual_sha1_return)
1203 memcpy(actual_sha1_return, actual_sha1, 20);
1206 /* Handle references */
1207 else if (!strcmp(type, "commit"))
1209 else if (!strcmp(type, "tag"))
1210 ref_type = "object ";
1215 ref_length = strlen(ref_type);
1217 if (memcmp(buffer, ref_type, ref_length) ||
1218 get_sha1_hex(buffer + ref_length, actual_sha1)) {
1223 /* Now we have the ID of the referred-to object in
1224 * actual_sha1. Check again. */
1228 char *write_sha1_file_prepare(void *buf,
1231 unsigned char *sha1,
1237 /* Generate the header */
1238 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1242 SHA1_Update(&c, hdr, *hdrlen);
1243 SHA1_Update(&c, buf, len);
1244 SHA1_Final(sha1, &c);
1246 return sha1_file_name(sha1);
1249 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1252 unsigned char *compressed;
1254 unsigned char sha1[20];
1256 static char tmpfile[PATH_MAX];
1257 unsigned char hdr[50];
1258 int fd, hdrlen, ret;
1260 /* Normally if we have it in the pack then we do not bother writing
1261 * it out into .git/objects/??/?{38} file.
1263 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1265 memcpy(returnsha1, sha1, 20);
1266 if (has_sha1_file(sha1))
1268 fd = open(filename, O_RDONLY);
1271 * FIXME!!! We might do collision checking here, but we'd
1272 * need to uncompress the old file and check it. Later.
1278 if (errno != ENOENT) {
1279 fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
1283 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1285 fd = mkstemp(tmpfile);
1287 fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
1292 memset(&stream, 0, sizeof(stream));
1293 deflateInit(&stream, Z_BEST_COMPRESSION);
1294 size = deflateBound(&stream, len+hdrlen);
1295 compressed = xmalloc(size);
1298 stream.next_out = compressed;
1299 stream.avail_out = size;
1301 /* First header.. */
1302 stream.next_in = hdr;
1303 stream.avail_in = hdrlen;
1304 while (deflate(&stream, 0) == Z_OK)
1307 /* Then the data itself.. */
1308 stream.next_in = buf;
1309 stream.avail_in = len;
1310 while (deflate(&stream, Z_FINISH) == Z_OK)
1312 deflateEnd(&stream);
1313 size = stream.total_out;
1315 if (write(fd, compressed, size) != size)
1316 die("unable to write file");
1321 ret = link(tmpfile, filename);
1326 * Coda hack - coda doesn't like cross-directory links,
1327 * so we fall back to a rename, which will mean that it
1328 * won't be able to check collisions, but that's not a
1331 * When this succeeds, we just return 0. We have nothing
1334 if (ret == EXDEV && !rename(tmpfile, filename))
1339 if (ret != EEXIST) {
1340 fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
1343 /* FIXME!!! Collision check here ? */
1349 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1352 unsigned long objsize;
1354 void *map = map_sha1_file_internal(sha1, &objsize);
1356 void *temp_obj = NULL;
1360 unsigned char *unpacked;
1365 // need to unpack and recompress it by itself
1366 unpacked = read_packed_sha1(sha1, type, &len);
1368 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1371 memset(&stream, 0, sizeof(stream));
1372 deflateInit(&stream, Z_BEST_COMPRESSION);
1373 size = deflateBound(&stream, len + hdrlen);
1374 temp_obj = buf = xmalloc(size);
1377 stream.next_out = buf;
1378 stream.avail_out = size;
1380 /* First header.. */
1381 stream.next_in = (void *)hdr;
1382 stream.avail_in = hdrlen;
1383 while (deflate(&stream, 0) == Z_OK)
1386 /* Then the data itself.. */
1387 stream.next_in = unpacked;
1388 stream.avail_in = len;
1389 while (deflate(&stream, Z_FINISH) == Z_OK)
1391 deflateEnd(&stream);
1394 objsize = stream.total_out;
1398 size = write(fd, buf + posn, objsize - posn);
1401 fprintf(stderr, "write closed");
1408 } while (posn < objsize);
1411 munmap(map, objsize);
1418 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1419 size_t bufsize, size_t *bufposn)
1421 char *filename = sha1_file_name(sha1);
1425 unsigned char real_sha1[20];
1426 unsigned char discard[4096];
1430 local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
1433 return error("Couldn't open %s\n", filename);
1435 memset(&stream, 0, sizeof(stream));
1437 inflateInit(&stream);
1444 stream.avail_in = *bufposn;
1445 stream.next_in = (unsigned char *) buffer;
1447 stream.next_out = discard;
1448 stream.avail_out = sizeof(discard);
1449 ret = inflate(&stream, Z_SYNC_FLUSH);
1450 SHA1_Update(&c, discard, sizeof(discard) -
1452 } while (stream.avail_in && ret == Z_OK);
1453 write(local, buffer, *bufposn - stream.avail_in);
1454 memmove(buffer, buffer + *bufposn - stream.avail_in,
1456 *bufposn = stream.avail_in;
1460 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1465 return error("Connection closed?");
1466 perror("Reading from connection");
1471 inflateEnd(&stream);
1474 SHA1_Final(real_sha1, &c);
1475 if (ret != Z_STREAM_END) {
1477 return error("File %s corrupted", sha1_to_hex(sha1));
1479 if (memcmp(sha1, real_sha1, 20)) {
1481 return error("File %s has bad hash\n", sha1_to_hex(sha1));
1487 int has_pack_index(const unsigned char *sha1)
1490 if (stat(sha1_pack_index_name(sha1), &st))
1495 int has_pack_file(const unsigned char *sha1)
1498 if (stat(sha1_pack_name(sha1), &st))
1503 int has_sha1_pack(const unsigned char *sha1)
1505 struct pack_entry e;
1506 return find_pack_entry(sha1, &e);
1509 int has_sha1_file(const unsigned char *sha1)
1512 struct pack_entry e;
1514 if (find_pack_entry(sha1, &e))
1516 return find_sha1_file(sha1, &st) ? 1 : 0;
1519 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1521 unsigned long size = st->st_size;
1524 unsigned char hdr[50];
1529 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1531 if (buf == MAP_FAILED)
1537 ret = write_sha1_file(buf, size, type, sha1);
1539 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);