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
31 const unsigned char null_sha1[20];
33 static unsigned int sha1_file_open_flag = O_NOATIME;
35 signed char hexval_table[256] = {
36 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
37 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
38 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
42 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
43 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
44 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
45 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
46 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
47 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
48 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
51 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
70 int get_sha1_hex(const char *hex, unsigned char *sha1)
73 for (i = 0; i < 20; i++) {
74 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
83 int safe_create_leading_directories(char *path)
92 pos = strchr(pos, '/');
96 if (!stat(path, &st)) {
98 if (!S_ISDIR(st.st_mode)) {
103 else if (mkdir(path, 0777)) {
107 else if (adjust_shared_perm(path)) {
116 char * sha1_to_hex(const unsigned char *sha1)
119 static char hexbuffer[4][50];
120 static const char hex[] = "0123456789abcdef";
121 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
124 for (i = 0; i < 20; i++) {
125 unsigned int val = *sha1++;
126 *buf++ = hex[val >> 4];
127 *buf++ = hex[val & 0xf];
134 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
137 for (i = 0; i < 20; i++) {
138 static char hex[] = "0123456789abcdef";
139 unsigned int val = sha1[i];
140 char *pos = pathbuf + i*2 + (i > 0);
141 *pos++ = hex[val >> 4];
142 *pos = hex[val & 0xf];
147 * NOTE! This returns a statically allocated buffer, so you have to be
148 * careful about using it. Do a "xstrdup()" if you need to save the
151 * Also note that this returns the location for creating. Reading
152 * SHA1 file can happen from any alternate directory listed in the
153 * DB_ENVIRONMENT environment variable if it is not found in
154 * the primary object database.
156 char *sha1_file_name(const unsigned char *sha1)
158 static char *name, *base;
161 const char *sha1_file_directory = get_object_directory();
162 int len = strlen(sha1_file_directory);
163 base = xmalloc(len + 60);
164 memcpy(base, sha1_file_directory, len);
165 memset(base+len, 0, 60);
168 name = base + len + 1;
170 fill_sha1_path(name, sha1);
174 char *sha1_pack_name(const unsigned char *sha1)
176 static const char hex[] = "0123456789abcdef";
177 static char *name, *base, *buf;
181 const char *sha1_file_directory = get_object_directory();
182 int len = strlen(sha1_file_directory);
183 base = xmalloc(len + 60);
184 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
185 name = base + len + 11;
190 for (i = 0; i < 20; i++) {
191 unsigned int val = *sha1++;
192 *buf++ = hex[val >> 4];
193 *buf++ = hex[val & 0xf];
199 char *sha1_pack_index_name(const unsigned char *sha1)
201 static const char hex[] = "0123456789abcdef";
202 static char *name, *base, *buf;
206 const char *sha1_file_directory = get_object_directory();
207 int len = strlen(sha1_file_directory);
208 base = xmalloc(len + 60);
209 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
210 name = base + len + 11;
215 for (i = 0; i < 20; i++) {
216 unsigned int val = *sha1++;
217 *buf++ = hex[val >> 4];
218 *buf++ = hex[val & 0xf];
224 struct alternate_object_database *alt_odb_list;
225 static struct alternate_object_database **alt_odb_tail;
227 static void read_info_alternates(const char * alternates, int depth);
230 * Prepare alternate object database registry.
232 * The variable alt_odb_list points at the list of struct
233 * alternate_object_database. The elements on this list come from
234 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
235 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
236 * whose contents is similar to that environment variable but can be
237 * LF separated. Its base points at a statically allocated buffer that
238 * contains "/the/directory/corresponding/to/.git/objects/...", while
239 * its name points just after the slash at the end of ".git/objects/"
240 * in the example above, and has enough space to hold 40-byte hex
241 * SHA1, an extra slash for the first level indirection, and the
244 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
247 const char *objdir = get_object_directory();
248 struct alternate_object_database *ent;
249 struct alternate_object_database *alt;
250 /* 43 = 40-byte + 2 '/' + terminating NUL */
252 int entlen = pfxlen + 43;
255 if (*entry != '/' && relative_base) {
256 /* Relative alt-odb */
258 base_len = strlen(relative_base) + 1;
262 ent = xmalloc(sizeof(*ent) + entlen);
264 if (*entry != '/' && relative_base) {
265 memcpy(ent->base, relative_base, base_len - 1);
266 ent->base[base_len - 1] = '/';
267 memcpy(ent->base + base_len, entry, len);
270 memcpy(ent->base, entry, pfxlen);
272 ent->name = ent->base + pfxlen + 1;
273 ent->base[pfxlen + 3] = '/';
274 ent->base[pfxlen] = ent->base[entlen-1] = 0;
276 /* Detect cases where alternate disappeared */
277 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
278 error("object directory %s does not exist; "
279 "check .git/objects/info/alternates.",
285 /* Prevent the common mistake of listing the same
286 * thing twice, or object directory itself.
288 for (alt = alt_odb_list; alt; alt = alt->next) {
289 if (!memcmp(ent->base, alt->base, pfxlen)) {
294 if (!memcmp(ent->base, objdir, pfxlen)) {
299 /* add the alternate entry */
301 alt_odb_tail = &(ent->next);
304 /* recursively add alternates */
305 read_info_alternates(ent->base, depth + 1);
307 ent->base[pfxlen] = '/';
312 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
313 const char *relative_base, int depth)
315 const char *cp, *last;
318 error("%s: ignoring alternate object stores, nesting too deep.",
326 if (cp < ep && *cp == '#') {
327 while (cp < ep && *cp != sep)
332 while (cp < ep && *cp != sep)
335 if ((*last != '/') && depth) {
336 error("%s: ignoring relative alternate object store %s",
337 relative_base, last);
339 link_alt_odb_entry(last, cp - last,
340 relative_base, depth);
343 while (cp < ep && *cp == sep)
349 static void read_info_alternates(const char * relative_base, int depth)
356 sprintf(path, "%s/info/alternates", relative_base);
357 fd = open(path, O_RDONLY);
360 if (fstat(fd, &st) || (st.st_size == 0)) {
364 map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
367 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
369 munmap(map, st.st_size);
372 void prepare_alt_odb(void)
376 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
381 alt_odb_tail = &alt_odb_list;
382 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
384 read_info_alternates(get_object_directory(), 0);
387 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
389 char *name = sha1_file_name(sha1);
390 struct alternate_object_database *alt;
395 for (alt = alt_odb_list; alt; alt = alt->next) {
397 fill_sha1_path(name, sha1);
398 if (!stat(alt->base, st))
404 static unsigned int pack_used_ctr;
405 static unsigned int pack_mmap_calls;
406 static unsigned int peak_pack_open_windows;
407 static unsigned int pack_open_windows;
408 static size_t peak_pack_mapped;
409 static size_t pack_mapped;
410 static size_t page_size;
411 struct packed_git *packed_git;
416 "pack_report: getpagesize() = %10" SZ_FMT "\n"
417 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
418 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
420 packed_git_window_size,
423 "pack_report: pack_used_ctr = %10u\n"
424 "pack_report: pack_mmap_calls = %10u\n"
425 "pack_report: pack_open_windows = %10u / %10u\n"
426 "pack_report: pack_mapped = "
427 "%10" SZ_FMT " / %10" SZ_FMT "\n",
430 pack_open_windows, peak_pack_open_windows,
431 pack_mapped, peak_pack_mapped);
434 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
439 unsigned long idx_size;
441 int fd = open(path, O_RDONLY);
445 if (fstat(fd, &st)) {
449 idx_size = st.st_size;
450 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
455 *idx_size_ = idx_size;
457 /* check index map */
458 if (idx_size < 4*256 + 20 + 20)
459 return error("index file too small");
461 for (i = 0; i < 256; i++) {
462 unsigned int n = ntohl(index[i]);
464 return error("non-monotonic index");
470 * - 256 index entries 4 bytes each
471 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
472 * - 20-byte SHA1 of the packfile
473 * - 20-byte SHA1 file checksum
475 if (idx_size != 4*256 + nr * 24 + 20 + 20)
476 return error("wrong index file size");
481 static void scan_windows(struct packed_git *p,
482 struct packed_git **lru_p,
483 struct pack_window **lru_w,
484 struct pack_window **lru_l)
486 struct pack_window *w, *w_l;
488 for (w_l = NULL, w = p->windows; w; w = w->next) {
490 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
500 static int unuse_one_window(struct packed_git *current)
502 struct packed_git *p, *lru_p = NULL;
503 struct pack_window *lru_w = NULL, *lru_l = NULL;
506 scan_windows(current, &lru_p, &lru_w, &lru_l);
507 for (p = packed_git; p; p = p->next)
508 scan_windows(p, &lru_p, &lru_w, &lru_l);
510 munmap(lru_w->base, lru_w->len);
511 pack_mapped -= lru_w->len;
513 lru_l->next = lru_w->next;
515 lru_p->windows = lru_w->next;
516 if (!lru_p->windows && lru_p != current) {
517 close(lru_p->pack_fd);
528 void release_pack_memory(size_t need)
530 size_t cur = pack_mapped;
531 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
535 void unuse_pack(struct pack_window **w_cursor)
537 struct pack_window *w = *w_cursor;
544 static void open_packed_git(struct packed_git *p)
547 struct pack_header hdr;
548 unsigned char sha1[20];
549 unsigned char *idx_sha1;
552 p->pack_fd = open(p->pack_name, O_RDONLY);
553 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
554 die("packfile %s cannot be opened", p->pack_name);
556 /* If we created the struct before we had the pack we lack size. */
558 if (!S_ISREG(st.st_mode))
559 die("packfile %s not a regular file", p->pack_name);
560 p->pack_size = st.st_size;
561 } else if (p->pack_size != st.st_size)
562 die("packfile %s size changed", p->pack_name);
564 /* We leave these file descriptors open with sliding mmap;
565 * there is no point keeping them open across exec(), though.
567 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
569 die("cannot determine file descriptor flags");
570 fd_flag |= FD_CLOEXEC;
571 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
572 die("cannot set FD_CLOEXEC");
574 /* Verify we recognize this pack file format. */
575 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
576 die("file %s is far too short to be a packfile", p->pack_name);
577 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
578 die("file %s is not a GIT packfile", p->pack_name);
579 if (!pack_version_ok(hdr.hdr_version))
580 die("packfile %s is version %u and not supported"
581 " (try upgrading GIT to a newer version)",
582 p->pack_name, ntohl(hdr.hdr_version));
584 /* Verify the pack matches its index. */
585 if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
586 die("packfile %s claims to have %u objects"
587 " while index size indicates %u objects",
588 p->pack_name, ntohl(hdr.hdr_entries),
589 num_packed_objects(p));
590 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
591 die("end of packfile %s is unavailable", p->pack_name);
592 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
593 die("packfile %s signature is unavailable", p->pack_name);
594 idx_sha1 = ((unsigned char *)p->index_base) + p->index_size - 40;
595 if (hashcmp(sha1, idx_sha1))
596 die("packfile %s does not match index", p->pack_name);
599 static int in_window(struct pack_window *win, unsigned long offset)
601 /* We must promise at least 20 bytes (one hash) after the
602 * offset is available from this window, otherwise the offset
603 * is not actually in this window and a different window (which
604 * has that one hash excess) must be used. This is to support
605 * the object header and delta base parsing routines below.
607 off_t win_off = win->offset;
608 return win_off <= offset
609 && (offset + 20) <= (win_off + win->len);
612 unsigned char* use_pack(struct packed_git *p,
613 struct pack_window **w_cursor,
614 unsigned long offset,
617 struct pack_window *win = *w_cursor;
619 if (p->pack_fd == -1)
622 /* Since packfiles end in a hash of their content and its
623 * pointless to ask for an offset into the middle of that
624 * hash, and the in_window function above wouldn't match
625 * don't allow an offset too close to the end of the file.
627 if (offset > (p->pack_size - 20))
628 die("offset beyond end of packfile (truncated pack?)");
630 if (!win || !in_window(win, offset)) {
633 for (win = p->windows; win; win = win->next) {
634 if (in_window(win, offset))
639 page_size = getpagesize();
640 win = xcalloc(1, sizeof(*win));
641 win->offset = (offset / page_size) * page_size;
642 win->len = p->pack_size - win->offset;
643 if (win->len > packed_git_window_size)
644 win->len = packed_git_window_size;
645 pack_mapped += win->len;
646 while (packed_git_limit < pack_mapped
647 && unuse_one_window(p))
649 win->base = xmmap(NULL, win->len,
650 PROT_READ, MAP_PRIVATE,
651 p->pack_fd, win->offset);
652 if (win->base == MAP_FAILED)
653 die("packfile %s cannot be mapped: %s",
658 if (pack_mapped > peak_pack_mapped)
659 peak_pack_mapped = pack_mapped;
660 if (pack_open_windows > peak_pack_open_windows)
661 peak_pack_open_windows = pack_open_windows;
662 win->next = p->windows;
666 if (win != *w_cursor) {
667 win->last_used = pack_used_ctr++;
671 offset -= win->offset;
673 *left = win->len - offset;
674 return win->base + offset;
677 struct packed_git *add_packed_git(char *path, int path_len, int local)
680 struct packed_git *p;
681 unsigned long idx_size;
683 unsigned char sha1[20];
685 if (check_packed_git_idx(path, &idx_size, &idx_map))
688 /* do we have a corresponding .pack file? */
689 strcpy(path + path_len - 4, ".pack");
690 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
691 munmap(idx_map, idx_size);
694 /* ok, it looks sane as far as we can check without
695 * actually mapping the pack file.
697 p = xmalloc(sizeof(*p) + path_len + 2);
698 strcpy(p->pack_name, path);
699 p->index_size = idx_size;
700 p->pack_size = st.st_size;
701 p->index_base = idx_map;
705 p->pack_local = local;
706 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
707 hashcpy(p->sha1, sha1);
711 struct packed_git *parse_pack_index(unsigned char *sha1)
713 char *path = sha1_pack_index_name(sha1);
714 return parse_pack_index_file(sha1, path);
717 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
719 struct packed_git *p;
720 unsigned long idx_size;
724 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
727 path = sha1_pack_name(sha1);
729 p = xmalloc(sizeof(*p) + strlen(path) + 2);
730 strcpy(p->pack_name, path);
731 p->index_size = idx_size;
733 p->index_base = idx_map;
737 hashcpy(p->sha1, sha1);
741 void install_packed_git(struct packed_git *pack)
743 pack->next = packed_git;
747 static void prepare_packed_git_one(char *objdir, int local)
754 sprintf(path, "%s/pack", objdir);
759 error("unable to open object pack directory: %s: %s",
760 path, strerror(errno));
764 while ((de = readdir(dir)) != NULL) {
765 int namelen = strlen(de->d_name);
766 struct packed_git *p;
768 if (!has_extension(de->d_name, ".idx"))
771 /* we have .idx. Is it a file we can map? */
772 strcpy(path + len, de->d_name);
773 for (p = packed_git; p; p = p->next) {
774 if (!memcmp(path, p->pack_name, len + namelen - 4))
779 p = add_packed_git(path, len + namelen, local);
782 p->next = packed_git;
788 static int prepare_packed_git_run_once = 0;
789 void prepare_packed_git(void)
791 struct alternate_object_database *alt;
793 if (prepare_packed_git_run_once)
795 prepare_packed_git_one(get_object_directory(), 1);
797 for (alt = alt_odb_list; alt; alt = alt->next) {
799 prepare_packed_git_one(alt->base, 0);
802 prepare_packed_git_run_once = 1;
805 void reprepare_packed_git(void)
807 prepare_packed_git_run_once = 0;
808 prepare_packed_git();
811 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
813 unsigned char real_sha1[20];
814 hash_sha1_file(map, size, type, real_sha1);
815 return hashcmp(sha1, real_sha1) ? -1 : 0;
818 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
823 char *filename = find_sha1_file(sha1, &st);
829 fd = open(filename, O_RDONLY | sha1_file_open_flag);
831 /* See if it works without O_NOATIME */
832 switch (sha1_file_open_flag) {
834 fd = open(filename, O_RDONLY);
842 /* If it failed once, it will probably fail again.
843 * Stop using O_NOATIME
845 sha1_file_open_flag = 0;
847 map = xmmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
853 int legacy_loose_object(unsigned char *map)
858 * Is it a zlib-compressed buffer? If so, the first byte
859 * must be 0x78 (15-bit window size, deflated), and the
860 * first 16-bit word is evenly divisible by 31
862 word = (map[0] << 8) + map[1];
863 if (map[0] == 0x78 && !(word % 31))
869 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
874 unsigned long used = 0;
877 *type = (c >> 4) & 7;
883 if (sizeof(long) * 8 <= shift)
886 size += (c & 0x7f) << shift;
893 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
895 unsigned long size, used;
896 static const char valid_loose_object_type[8] = {
898 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
899 0, /* "delta" and others are invalid in a loose object */
901 enum object_type type;
903 /* Get the data stream */
904 memset(stream, 0, sizeof(*stream));
905 stream->next_in = map;
906 stream->avail_in = mapsize;
907 stream->next_out = buffer;
908 stream->avail_out = bufsiz;
910 if (legacy_loose_object(map)) {
912 return inflate(stream, 0);
915 used = unpack_object_header_gently(map, mapsize, &type, &size);
916 if (!used || !valid_loose_object_type[type])
921 /* Set up the stream for the rest.. */
922 stream->next_in = map;
923 stream->avail_in = mapsize;
926 /* And generate the fake traditional header */
927 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
928 type_names[type], size);
932 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
934 int bytes = strlen(buffer) + 1;
935 unsigned char *buf = xmalloc(1+size);
938 n = stream->total_out - bytes;
941 memcpy(buf, (char *) buffer + bytes, n);
944 stream->next_out = buf + bytes;
945 stream->avail_out = size - bytes;
946 while (inflate(stream, Z_FINISH) == Z_OK)
955 * We used to just use "sscanf()", but that's actually way
956 * too permissive for what we want to check. So do an anal
957 * object header parse by hand.
959 static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
965 * The type can be at most ten bytes (including the
966 * terminating '\0' that we add), and is followed by
981 * The length must follow immediately, and be in canonical
982 * decimal format (ie "010" is not valid).
989 unsigned long c = *hdr - '0';
993 size = size * 10 + c;
999 * The length must be followed by a zero byte
1001 return *hdr ? -1 : 0;
1004 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
1010 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1011 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
1014 return unpack_sha1_rest(&stream, hdr, *size);
1017 static unsigned long get_delta_base(struct packed_git *p,
1018 struct pack_window **w_curs,
1019 unsigned long offset,
1020 enum object_type kind,
1021 unsigned long delta_obj_offset,
1022 unsigned long *base_obj_offset)
1024 unsigned char *base_info = use_pack(p, w_curs, offset, NULL);
1025 unsigned long base_offset;
1027 /* use_pack() assured us we have [base_info, base_info + 20)
1028 * as a range that we can look at without walking off the
1029 * end of the mapped window. Its actually the hash size
1030 * that is assured. An OFS_DELTA longer than the hash size
1031 * is stupid, as then a REF_DELTA would be smaller to store.
1033 if (kind == OBJ_OFS_DELTA) {
1035 unsigned char c = base_info[used++];
1036 base_offset = c & 127;
1039 if (!base_offset || base_offset & ~(~0UL >> 7))
1040 die("offset value overflow for delta base object");
1041 c = base_info[used++];
1042 base_offset = (base_offset << 7) + (c & 127);
1044 base_offset = delta_obj_offset - base_offset;
1045 if (base_offset >= delta_obj_offset)
1046 die("delta base offset out of bound");
1048 } else if (kind == OBJ_REF_DELTA) {
1049 /* The base entry _must_ be in the same pack */
1050 base_offset = find_pack_entry_one(base_info, p);
1052 die("failed to find delta-pack base object %s",
1053 sha1_to_hex(base_info));
1056 die("I am totally screwed");
1057 *base_obj_offset = base_offset;
1061 /* forward declaration for a mutually recursive function */
1062 static int packed_object_info(struct packed_git *p, unsigned long offset,
1063 char *type, unsigned long *sizep);
1065 static int packed_delta_info(struct packed_git *p,
1066 struct pack_window **w_curs,
1067 unsigned long offset,
1068 enum object_type kind,
1069 unsigned long obj_offset,
1071 unsigned long *sizep)
1073 unsigned long base_offset;
1075 offset = get_delta_base(p, w_curs, offset, kind,
1076 obj_offset, &base_offset);
1078 /* We choose to only get the type of the base object and
1079 * ignore potentially corrupt pack file that expects the delta
1080 * based on a base with a wrong size. This saves tons of
1083 if (packed_object_info(p, base_offset, type, NULL))
1084 die("cannot get info for delta-pack base");
1087 const unsigned char *data;
1088 unsigned char delta_head[20], *in;
1089 unsigned long result_size;
1093 memset(&stream, 0, sizeof(stream));
1094 stream.next_out = delta_head;
1095 stream.avail_out = sizeof(delta_head);
1097 inflateInit(&stream);
1099 in = use_pack(p, w_curs, offset, &stream.avail_in);
1100 stream.next_in = in;
1101 st = inflate(&stream, Z_FINISH);
1102 offset += stream.next_in - in;
1103 } while ((st == Z_OK || st == Z_BUF_ERROR)
1104 && stream.total_out < sizeof(delta_head));
1105 inflateEnd(&stream);
1106 if ((st != Z_STREAM_END) &&
1107 stream.total_out != sizeof(delta_head))
1108 die("delta data unpack-initial failed");
1110 /* Examine the initial part of the delta to figure out
1115 /* ignore base size */
1116 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1118 /* Read the result size */
1119 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1120 *sizep = result_size;
1125 static unsigned long unpack_object_header(struct packed_git *p,
1126 struct pack_window **w_curs,
1127 unsigned long offset,
1128 enum object_type *type,
1129 unsigned long *sizep)
1131 unsigned char *base;
1135 /* use_pack() assures us we have [base, base + 20) available
1136 * as a range that we can look at at. (Its actually the hash
1137 * size that is assurred.) With our object header encoding
1138 * the maximum deflated object size is 2^137, which is just
1139 * insane, so we know won't exceed what we have been given.
1141 base = use_pack(p, w_curs, offset, &left);
1142 used = unpack_object_header_gently(base, left, type, sizep);
1144 die("object offset outside of pack file");
1146 return offset + used;
1149 void packed_object_info_detail(struct packed_git *p,
1150 unsigned long offset,
1152 unsigned long *size,
1153 unsigned long *store_size,
1154 unsigned int *delta_chain_length,
1155 unsigned char *base_sha1)
1157 struct pack_window *w_curs = NULL;
1158 unsigned long obj_offset, val;
1159 unsigned char *next_sha1;
1160 enum object_type kind;
1162 *delta_chain_length = 0;
1163 obj_offset = offset;
1164 offset = unpack_object_header(p, &w_curs, offset, &kind, size);
1169 die("pack %s contains unknown object type %d",
1170 p->pack_name, kind);
1175 strcpy(type, type_names[kind]);
1176 *store_size = 0; /* notyet */
1177 unuse_pack(&w_curs);
1180 get_delta_base(p, &w_curs, offset, kind,
1181 obj_offset, &offset);
1182 if (*delta_chain_length == 0) {
1183 /* TODO: find base_sha1 as pointed by offset */
1187 next_sha1 = use_pack(p, &w_curs, offset, NULL);
1188 if (*delta_chain_length == 0)
1189 hashcpy(base_sha1, next_sha1);
1190 offset = find_pack_entry_one(next_sha1, p);
1193 obj_offset = offset;
1194 offset = unpack_object_header(p, &w_curs, offset, &kind, &val);
1195 (*delta_chain_length)++;
1199 static int packed_object_info(struct packed_git *p, unsigned long offset,
1200 char *type, unsigned long *sizep)
1202 struct pack_window *w_curs = NULL;
1203 unsigned long size, obj_offset = offset;
1204 enum object_type kind;
1207 offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
1212 r = packed_delta_info(p, &w_curs, offset, kind,
1213 obj_offset, type, sizep);
1214 unuse_pack(&w_curs);
1220 strcpy(type, type_names[kind]);
1221 unuse_pack(&w_curs);
1224 die("pack %s contains unknown object type %d",
1225 p->pack_name, kind);
1232 static void *unpack_compressed_entry(struct packed_git *p,
1233 struct pack_window **w_curs,
1234 unsigned long offset,
1239 unsigned char *buffer, *in;
1241 buffer = xmalloc(size + 1);
1243 memset(&stream, 0, sizeof(stream));
1244 stream.next_out = buffer;
1245 stream.avail_out = size;
1247 inflateInit(&stream);
1249 in = use_pack(p, w_curs, offset, &stream.avail_in);
1250 stream.next_in = in;
1251 st = inflate(&stream, Z_FINISH);
1252 offset += stream.next_in - in;
1253 } while (st == Z_OK || st == Z_BUF_ERROR);
1254 inflateEnd(&stream);
1255 if ((st != Z_STREAM_END) || stream.total_out != size) {
1263 static void *unpack_delta_entry(struct packed_git *p,
1264 struct pack_window **w_curs,
1265 unsigned long offset,
1266 unsigned long delta_size,
1267 enum object_type kind,
1268 unsigned long obj_offset,
1270 unsigned long *sizep)
1272 void *delta_data, *result, *base;
1273 unsigned long result_size, base_size, base_offset;
1275 offset = get_delta_base(p, w_curs, offset, kind,
1276 obj_offset, &base_offset);
1277 base = unpack_entry(p, base_offset, type, &base_size);
1279 die("failed to read delta base object at %lu from %s",
1280 base_offset, p->pack_name);
1282 delta_data = unpack_compressed_entry(p, w_curs, offset, delta_size);
1283 result = patch_delta(base, base_size,
1284 delta_data, delta_size,
1287 die("failed to apply delta");
1290 *sizep = result_size;
1294 void *unpack_entry(struct packed_git *p, unsigned long offset,
1295 char *type, unsigned long *sizep)
1297 struct pack_window *w_curs = NULL;
1298 unsigned long size, obj_offset = offset;
1299 enum object_type kind;
1302 offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
1306 retval = unpack_delta_entry(p, &w_curs, offset, size,
1307 kind, obj_offset, type, sizep);
1313 strcpy(type, type_names[kind]);
1315 retval = unpack_compressed_entry(p, &w_curs, offset, size);
1318 die("unknown object type %i in %s", kind, p->pack_name);
1320 unuse_pack(&w_curs);
1324 int num_packed_objects(const struct packed_git *p)
1326 /* See check_packed_git_idx() */
1327 return (p->index_size - 20 - 20 - 4*256) / 24;
1330 int nth_packed_object_sha1(const struct packed_git *p, int n,
1331 unsigned char* sha1)
1333 void *index = p->index_base + 256;
1334 if (n < 0 || num_packed_objects(p) <= n)
1336 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1340 unsigned long find_pack_entry_one(const unsigned char *sha1,
1341 struct packed_git *p)
1343 unsigned int *level1_ofs = p->index_base;
1344 int hi = ntohl(level1_ofs[*sha1]);
1345 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1346 void *index = p->index_base + 256;
1349 int mi = (lo + hi) / 2;
1350 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1352 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1361 static int matches_pack_name(struct packed_git *p, const char *ig)
1363 const char *last_c, *c;
1365 if (!strcmp(p->pack_name, ig))
1368 for (c = p->pack_name, last_c = c; *c;)
1373 if (!strcmp(last_c, ig))
1379 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1381 struct packed_git *p;
1382 unsigned long offset;
1384 prepare_packed_git();
1386 for (p = packed_git; p; p = p->next) {
1387 if (ignore_packed) {
1389 for (ig = ignore_packed; *ig; ig++)
1390 if (!matches_pack_name(p, *ig))
1395 offset = find_pack_entry_one(sha1, p);
1399 hashcpy(e->sha1, sha1);
1406 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1407 struct packed_git *packs)
1409 struct packed_git *p;
1411 for (p = packs; p; p = p->next) {
1412 if (find_pack_entry_one(sha1, p))
1419 static int sha1_loose_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1422 unsigned long mapsize, size;
1427 map = map_sha1_file(sha1, &mapsize);
1429 return error("unable to find %s", sha1_to_hex(sha1));
1430 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1431 status = error("unable to unpack %s header",
1433 if (parse_sha1_header(hdr, type, &size) < 0)
1434 status = error("unable to parse %s header", sha1_to_hex(sha1));
1440 inflateEnd(&stream);
1441 munmap(map, mapsize);
1445 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1447 struct pack_entry e;
1449 if (!find_pack_entry(sha1, &e, NULL)) {
1450 reprepare_packed_git();
1451 if (!find_pack_entry(sha1, &e, NULL))
1452 return sha1_loose_object_info(sha1, type, sizep);
1454 return packed_object_info(e.p, e.offset, type, sizep);
1457 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1459 struct pack_entry e;
1461 if (!find_pack_entry(sha1, &e, NULL)) {
1462 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1465 return unpack_entry(e.p, e.offset, type, size);
1468 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1470 unsigned long mapsize;
1472 struct pack_entry e;
1474 if (find_pack_entry(sha1, &e, NULL))
1475 return read_packed_sha1(sha1, type, size);
1476 map = map_sha1_file(sha1, &mapsize);
1478 buf = unpack_sha1_file(map, mapsize, type, size);
1479 munmap(map, mapsize);
1482 reprepare_packed_git();
1483 if (find_pack_entry(sha1, &e, NULL))
1484 return read_packed_sha1(sha1, type, size);
1488 void *read_object_with_reference(const unsigned char *sha1,
1489 const char *required_type,
1490 unsigned long *size,
1491 unsigned char *actual_sha1_return)
1495 unsigned long isize;
1496 unsigned char actual_sha1[20];
1498 hashcpy(actual_sha1, sha1);
1500 int ref_length = -1;
1501 const char *ref_type = NULL;
1503 buffer = read_sha1_file(actual_sha1, type, &isize);
1506 if (!strcmp(type, required_type)) {
1508 if (actual_sha1_return)
1509 hashcpy(actual_sha1_return, actual_sha1);
1512 /* Handle references */
1513 else if (!strcmp(type, commit_type))
1515 else if (!strcmp(type, tag_type))
1516 ref_type = "object ";
1521 ref_length = strlen(ref_type);
1523 if (memcmp(buffer, ref_type, ref_length) ||
1524 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1529 /* Now we have the ID of the referred-to object in
1530 * actual_sha1. Check again. */
1534 static void write_sha1_file_prepare(void *buf, unsigned long len,
1535 const char *type, unsigned char *sha1,
1536 unsigned char *hdr, int *hdrlen)
1540 /* Generate the header */
1541 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1545 SHA1_Update(&c, hdr, *hdrlen);
1546 SHA1_Update(&c, buf, len);
1547 SHA1_Final(sha1, &c);
1551 * Link the tempfile to the final place, possibly creating the
1552 * last directory level as you do so.
1554 * Returns the errno on failure, 0 on success.
1556 static int link_temp_to_file(const char *tmpfile, const char *filename)
1561 if (!link(tmpfile, filename))
1565 * Try to mkdir the last path component if that failed.
1567 * Re-try the "link()" regardless of whether the mkdir
1568 * succeeds, since a race might mean that somebody
1572 dir = strrchr(filename, '/');
1575 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
1580 if (!link(tmpfile, filename))
1588 * Move the just written object into its final resting place
1590 int move_temp_to_file(const char *tmpfile, const char *filename)
1592 int ret = link_temp_to_file(tmpfile, filename);
1595 * Coda hack - coda doesn't like cross-directory links,
1596 * so we fall back to a rename, which will mean that it
1597 * won't be able to check collisions, but that's not a
1600 * The same holds for FAT formatted media.
1602 * When this succeeds, we just return 0. We have nothing
1605 if (ret && ret != EEXIST) {
1606 if (!rename(tmpfile, filename))
1612 if (ret != EEXIST) {
1613 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1615 /* FIXME!!! Collision check here ? */
1621 static int write_buffer(int fd, const void *buf, size_t len)
1623 if (write_in_full(fd, buf, len) < 0)
1624 return error("file write error (%s)", strerror(errno));
1628 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1633 c = (type << 4) | (len & 15);
1646 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1650 if (use_legacy_headers) {
1651 while (deflate(stream, 0) == Z_OK)
1655 if (!strcmp(type, blob_type))
1656 obj_type = OBJ_BLOB;
1657 else if (!strcmp(type, tree_type))
1658 obj_type = OBJ_TREE;
1659 else if (!strcmp(type, commit_type))
1660 obj_type = OBJ_COMMIT;
1661 else if (!strcmp(type, tag_type))
1664 die("trying to generate bogus object of type '%s'", type);
1665 hdr = write_binary_header(stream->next_out, obj_type, len);
1666 stream->total_out = hdr;
1667 stream->next_out += hdr;
1668 stream->avail_out -= hdr;
1671 int hash_sha1_file(void *buf, unsigned long len, const char *type,
1672 unsigned char *sha1)
1674 unsigned char hdr[50];
1676 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1680 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1683 unsigned char *compressed;
1685 unsigned char sha1[20];
1687 static char tmpfile[PATH_MAX];
1688 unsigned char hdr[50];
1691 /* Normally if we have it in the pack then we do not bother writing
1692 * it out into .git/objects/??/?{38} file.
1694 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1695 filename = sha1_file_name(sha1);
1697 hashcpy(returnsha1, sha1);
1698 if (has_sha1_file(sha1))
1700 fd = open(filename, O_RDONLY);
1703 * FIXME!!! We might do collision checking here, but we'd
1704 * need to uncompress the old file and check it. Later.
1710 if (errno != ENOENT) {
1711 return error("sha1 file %s: %s\n", filename, strerror(errno));
1714 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1716 fd = mkstemp(tmpfile);
1719 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1721 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1725 memset(&stream, 0, sizeof(stream));
1726 deflateInit(&stream, zlib_compression_level);
1727 size = 8 + deflateBound(&stream, len+hdrlen);
1728 compressed = xmalloc(size);
1731 stream.next_out = compressed;
1732 stream.avail_out = size;
1734 /* First header.. */
1735 stream.next_in = hdr;
1736 stream.avail_in = hdrlen;
1737 setup_object_header(&stream, type, len);
1739 /* Then the data itself.. */
1740 stream.next_in = buf;
1741 stream.avail_in = len;
1742 while (deflate(&stream, Z_FINISH) == Z_OK)
1744 deflateEnd(&stream);
1745 size = stream.total_out;
1747 if (write_buffer(fd, compressed, size) < 0)
1748 die("unable to write sha1 file");
1753 return move_temp_to_file(tmpfile, filename);
1757 * We need to unpack and recompress the object for writing
1758 * it out to a different file.
1760 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1764 unsigned char *unpacked;
1771 /* need to unpack and recompress it by itself */
1772 unpacked = read_packed_sha1(sha1, type, &len);
1774 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1777 memset(&stream, 0, sizeof(stream));
1778 deflateInit(&stream, zlib_compression_level);
1779 size = deflateBound(&stream, len + hdrlen);
1780 buf = xmalloc(size);
1783 stream.next_out = buf;
1784 stream.avail_out = size;
1786 /* First header.. */
1787 stream.next_in = (void *)hdr;
1788 stream.avail_in = hdrlen;
1789 while (deflate(&stream, 0) == Z_OK)
1792 /* Then the data itself.. */
1793 stream.next_in = unpacked;
1794 stream.avail_in = len;
1795 while (deflate(&stream, Z_FINISH) == Z_OK)
1797 deflateEnd(&stream);
1800 *objsize = stream.total_out;
1804 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1807 unsigned long objsize;
1808 void *buf = map_sha1_file(sha1, &objsize);
1811 retval = write_buffer(fd, buf, objsize);
1812 munmap(buf, objsize);
1816 buf = repack_object(sha1, &objsize);
1817 retval = write_buffer(fd, buf, objsize);
1822 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1823 size_t bufsize, size_t *bufposn)
1825 char tmpfile[PATH_MAX];
1828 unsigned char real_sha1[20];
1829 unsigned char discard[4096];
1833 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1835 local = mkstemp(tmpfile);
1838 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1840 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1843 memset(&stream, 0, sizeof(stream));
1845 inflateInit(&stream);
1852 stream.avail_in = *bufposn;
1853 stream.next_in = (unsigned char *) buffer;
1855 stream.next_out = discard;
1856 stream.avail_out = sizeof(discard);
1857 ret = inflate(&stream, Z_SYNC_FLUSH);
1858 SHA1_Update(&c, discard, sizeof(discard) -
1860 } while (stream.avail_in && ret == Z_OK);
1861 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1862 die("unable to write sha1 file");
1863 memmove(buffer, buffer + *bufposn - stream.avail_in,
1865 *bufposn = stream.avail_in;
1869 size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
1874 return error("Connection closed?");
1875 perror("Reading from connection");
1880 inflateEnd(&stream);
1883 SHA1_Final(real_sha1, &c);
1884 if (ret != Z_STREAM_END) {
1886 return error("File %s corrupted", sha1_to_hex(sha1));
1888 if (hashcmp(sha1, real_sha1)) {
1890 return error("File %s has bad hash", sha1_to_hex(sha1));
1893 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1896 int has_pack_index(const unsigned char *sha1)
1899 if (stat(sha1_pack_index_name(sha1), &st))
1904 int has_pack_file(const unsigned char *sha1)
1907 if (stat(sha1_pack_name(sha1), &st))
1912 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1914 struct pack_entry e;
1915 return find_pack_entry(sha1, &e, ignore_packed);
1918 int has_sha1_file(const unsigned char *sha1)
1921 struct pack_entry e;
1923 if (find_pack_entry(sha1, &e, NULL))
1925 return find_sha1_file(sha1, &st) ? 1 : 0;
1929 * reads from fd as long as possible into a supplied buffer of size bytes.
1930 * If necessary the buffer's size is increased using realloc()
1932 * returns 0 if anything went fine and -1 otherwise
1934 * NOTE: both buf and size may change, but even when -1 is returned
1935 * you still have to free() it yourself.
1937 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1939 char* buf = *return_buf;
1940 unsigned long size = *return_size;
1942 unsigned long off = 0;
1945 iret = xread(fd, buf + off, size - off);
1950 buf = xrealloc(buf, size);
1963 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1965 unsigned long size = 4096;
1966 char *buf = xmalloc(size);
1969 if (read_pipe(fd, &buf, &size)) {
1977 ret = write_sha1_file(buf, size, type, sha1);
1979 ret = hash_sha1_file(buf, size, type, sha1);
1984 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1986 unsigned long size = st->st_size;
1992 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1998 ret = write_sha1_file(buf, size, type, sha1);
2000 ret = hash_sha1_file(buf, size, type, sha1);
2006 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2011 switch (st->st_mode & S_IFMT) {
2013 fd = open(path, O_RDONLY);
2015 return error("open(\"%s\"): %s", path,
2017 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
2018 return error("%s: failed to insert into database",
2022 target = xmalloc(st->st_size+1);
2023 if (readlink(path, target, st->st_size+1) != st->st_size) {
2024 char *errstr = strerror(errno);
2026 return error("readlink(\"%s\"): %s", path,
2030 hash_sha1_file(target, st->st_size, blob_type, sha1);
2031 else if (write_sha1_file(target, st->st_size, blob_type, sha1))
2032 return error("%s: failed to insert into database",
2037 return error("%s: unsupported file type", path);