2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
17 #include "pack-revindex.h"
18 #include "sha1-lookup.h"
21 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
22 #define O_NOATIME 01000000
30 static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
33 static size_t sz_fmt(size_t s) { return s; }
36 const unsigned char null_sha1[20];
38 static inline int offset_1st_component(const char *path)
40 if (has_dos_drive_prefix(path))
41 return 2 + (path[2] == '/');
45 int safe_create_leading_directories(char *path)
47 char *pos = path + offset_1st_component(path);
51 pos = strchr(pos, '/');
59 if (!stat(path, &st)) {
61 if (!S_ISDIR(st.st_mode)) {
66 else if (mkdir(path, 0777)) {
70 else if (adjust_shared_perm(path)) {
79 int safe_create_leading_directories_const(const char *path)
81 /* path points to cache entries, so xstrdup before messing with it */
82 char *buf = xstrdup(path);
83 int result = safe_create_leading_directories(buf);
88 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
91 for (i = 0; i < 20; i++) {
92 static char hex[] = "0123456789abcdef";
93 unsigned int val = sha1[i];
94 char *pos = pathbuf + i*2 + (i > 0);
95 *pos++ = hex[val >> 4];
96 *pos = hex[val & 0xf];
101 * NOTE! This returns a statically allocated buffer, so you have to be
102 * careful about using it. Do an "xstrdup()" if you need to save the
105 * Also note that this returns the location for creating. Reading
106 * SHA1 file can happen from any alternate directory listed in the
107 * DB_ENVIRONMENT environment variable if it is not found in
108 * the primary object database.
110 char *sha1_file_name(const unsigned char *sha1)
112 static char *name, *base;
115 const char *sha1_file_directory = get_object_directory();
116 int len = strlen(sha1_file_directory);
117 base = xmalloc(len + 60);
118 memcpy(base, sha1_file_directory, len);
119 memset(base+len, 0, 60);
122 name = base + len + 1;
124 fill_sha1_path(name, sha1);
128 static char *sha1_get_pack_name(const unsigned char *sha1,
129 char **name, char **base, const char *which)
131 static const char hex[] = "0123456789abcdef";
136 const char *sha1_file_directory = get_object_directory();
137 int len = strlen(sha1_file_directory);
138 *base = xmalloc(len + 60);
139 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
140 sha1_file_directory, which);
141 *name = *base + len + 11;
146 for (i = 0; i < 20; i++) {
147 unsigned int val = *sha1++;
148 *buf++ = hex[val >> 4];
149 *buf++ = hex[val & 0xf];
155 char *sha1_pack_name(const unsigned char *sha1)
157 static char *name, *base;
159 return sha1_get_pack_name(sha1, &name, &base, "pack");
162 char *sha1_pack_index_name(const unsigned char *sha1)
164 static char *name, *base;
166 return sha1_get_pack_name(sha1, &name, &base, "idx");
169 struct alternate_object_database *alt_odb_list;
170 static struct alternate_object_database **alt_odb_tail;
172 static void read_info_alternates(const char * alternates, int depth);
175 * Prepare alternate object database registry.
177 * The variable alt_odb_list points at the list of struct
178 * alternate_object_database. The elements on this list come from
179 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
180 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
181 * whose contents is similar to that environment variable but can be
182 * LF separated. Its base points at a statically allocated buffer that
183 * contains "/the/directory/corresponding/to/.git/objects/...", while
184 * its name points just after the slash at the end of ".git/objects/"
185 * in the example above, and has enough space to hold 40-byte hex
186 * SHA1, an extra slash for the first level indirection, and the
189 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
191 const char *objdir = get_object_directory();
192 struct alternate_object_database *ent;
193 struct alternate_object_database *alt;
194 /* 43 = 40-byte + 2 '/' + terminating NUL */
196 int entlen = pfxlen + 43;
199 if (!is_absolute_path(entry) && relative_base) {
200 /* Relative alt-odb */
202 base_len = strlen(relative_base) + 1;
206 ent = xmalloc(sizeof(*ent) + entlen);
208 if (!is_absolute_path(entry) && relative_base) {
209 memcpy(ent->base, relative_base, base_len - 1);
210 ent->base[base_len - 1] = '/';
211 memcpy(ent->base + base_len, entry, len);
214 memcpy(ent->base, entry, pfxlen);
216 ent->name = ent->base + pfxlen + 1;
217 ent->base[pfxlen + 3] = '/';
218 ent->base[pfxlen] = ent->base[entlen-1] = 0;
220 /* Detect cases where alternate disappeared */
221 if (!is_directory(ent->base)) {
222 error("object directory %s does not exist; "
223 "check .git/objects/info/alternates.",
229 /* Prevent the common mistake of listing the same
230 * thing twice, or object directory itself.
232 for (alt = alt_odb_list; alt; alt = alt->next) {
233 if (!memcmp(ent->base, alt->base, pfxlen)) {
238 if (!memcmp(ent->base, objdir, pfxlen)) {
243 /* add the alternate entry */
245 alt_odb_tail = &(ent->next);
248 /* recursively add alternates */
249 read_info_alternates(ent->base, depth + 1);
251 ent->base[pfxlen] = '/';
256 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
257 const char *relative_base, int depth)
259 const char *cp, *last;
262 error("%s: ignoring alternate object stores, nesting too deep.",
270 if (cp < ep && *cp == '#') {
271 while (cp < ep && *cp != sep)
276 while (cp < ep && *cp != sep)
279 if (!is_absolute_path(last) && depth) {
280 error("%s: ignoring relative alternate object store %s",
281 relative_base, last);
283 link_alt_odb_entry(last, cp - last,
284 relative_base, depth);
287 while (cp < ep && *cp == sep)
293 static void read_info_alternates(const char * relative_base, int depth)
298 const char alt_file_name[] = "info/alternates";
299 /* Given that relative_base is no longer than PATH_MAX,
300 ensure that "path" has enough space to append "/", the
301 file name, "info/alternates", and a trailing NUL. */
302 char path[PATH_MAX + 1 + sizeof alt_file_name];
305 sprintf(path, "%s/%s", relative_base, alt_file_name);
306 fd = open(path, O_RDONLY);
309 if (fstat(fd, &st) || (st.st_size == 0)) {
313 mapsz = xsize_t(st.st_size);
314 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
317 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
322 void add_to_alternates_file(const char *reference)
324 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
325 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
326 char *alt = mkpath("%s/objects\n", reference);
327 write_or_die(fd, alt, strlen(alt));
328 if (commit_lock_file(lock))
329 die("could not close alternates file");
331 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
334 void foreach_alt_odb(alt_odb_fn fn, void *cb)
336 struct alternate_object_database *ent;
339 for (ent = alt_odb_list; ent; ent = ent->next)
344 void prepare_alt_odb(void)
351 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
354 alt_odb_tail = &alt_odb_list;
355 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
357 read_info_alternates(get_object_directory(), 0);
360 static int has_loose_object_local(const unsigned char *sha1)
362 char *name = sha1_file_name(sha1);
363 return !access(name, F_OK);
366 int has_loose_object_nonlocal(const unsigned char *sha1)
368 struct alternate_object_database *alt;
370 for (alt = alt_odb_list; alt; alt = alt->next) {
371 fill_sha1_path(alt->name, sha1);
372 if (!access(alt->base, F_OK))
378 static int has_loose_object(const unsigned char *sha1)
380 return has_loose_object_local(sha1) ||
381 has_loose_object_nonlocal(sha1);
384 static unsigned int pack_used_ctr;
385 static unsigned int pack_mmap_calls;
386 static unsigned int peak_pack_open_windows;
387 static unsigned int pack_open_windows;
388 static size_t peak_pack_mapped;
389 static size_t pack_mapped;
390 struct packed_git *packed_git;
392 void pack_report(void)
395 "pack_report: getpagesize() = %10" SZ_FMT "\n"
396 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
397 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
398 sz_fmt(getpagesize()),
399 sz_fmt(packed_git_window_size),
400 sz_fmt(packed_git_limit));
402 "pack_report: pack_used_ctr = %10u\n"
403 "pack_report: pack_mmap_calls = %10u\n"
404 "pack_report: pack_open_windows = %10u / %10u\n"
405 "pack_report: pack_mapped = "
406 "%10" SZ_FMT " / %10" SZ_FMT "\n",
409 pack_open_windows, peak_pack_open_windows,
410 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
413 static int check_packed_git_idx(const char *path, struct packed_git *p)
416 struct pack_idx_header *hdr;
418 uint32_t version, nr, i, *index;
419 int fd = open(path, O_RDONLY);
424 if (fstat(fd, &st)) {
428 idx_size = xsize_t(st.st_size);
429 if (idx_size < 4 * 256 + 20 + 20) {
431 return error("index file %s is too small", path);
433 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
437 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
438 version = ntohl(hdr->idx_version);
439 if (version < 2 || version > 2) {
440 munmap(idx_map, idx_size);
441 return error("index file %s is version %"PRIu32
442 " and is not supported by this binary"
443 " (try upgrading GIT to a newer version)",
452 index += 2; /* skip index header */
453 for (i = 0; i < 256; i++) {
454 uint32_t n = ntohl(index[i]);
456 munmap(idx_map, idx_size);
457 return error("non-monotonic index %s", path);
465 * - 256 index entries 4 bytes each
466 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
467 * - 20-byte SHA1 of the packfile
468 * - 20-byte SHA1 file checksum
470 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
471 munmap(idx_map, idx_size);
472 return error("wrong index v1 file size in %s", path);
474 } else if (version == 2) {
477 * - 8 bytes of header
478 * - 256 index entries 4 bytes each
479 * - 20-byte sha1 entry * nr
480 * - 4-byte crc entry * nr
481 * - 4-byte offset entry * nr
482 * - 20-byte SHA1 of the packfile
483 * - 20-byte SHA1 file checksum
484 * And after the 4-byte offset table might be a
485 * variable sized table containing 8-byte entries
486 * for offsets larger than 2^31.
488 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
489 unsigned long max_size = min_size;
491 max_size += (nr - 1)*8;
492 if (idx_size < min_size || idx_size > max_size) {
493 munmap(idx_map, idx_size);
494 return error("wrong index v2 file size in %s", path);
496 if (idx_size != min_size &&
498 * make sure we can deal with large pack offsets.
499 * 31-bit signed offset won't be enough, neither
500 * 32-bit unsigned one will be.
502 (sizeof(off_t) <= 4)) {
503 munmap(idx_map, idx_size);
504 return error("pack too large for current definition of off_t in %s", path);
508 p->index_version = version;
509 p->index_data = idx_map;
510 p->index_size = idx_size;
515 int open_pack_index(struct packed_git *p)
523 idx_name = xstrdup(p->pack_name);
524 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
525 ret = check_packed_git_idx(idx_name, p);
530 static void scan_windows(struct packed_git *p,
531 struct packed_git **lru_p,
532 struct pack_window **lru_w,
533 struct pack_window **lru_l)
535 struct pack_window *w, *w_l;
537 for (w_l = NULL, w = p->windows; w; w = w->next) {
539 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
549 static int unuse_one_window(struct packed_git *current, int keep_fd)
551 struct packed_git *p, *lru_p = NULL;
552 struct pack_window *lru_w = NULL, *lru_l = NULL;
555 scan_windows(current, &lru_p, &lru_w, &lru_l);
556 for (p = packed_git; p; p = p->next)
557 scan_windows(p, &lru_p, &lru_w, &lru_l);
559 munmap(lru_w->base, lru_w->len);
560 pack_mapped -= lru_w->len;
562 lru_l->next = lru_w->next;
564 lru_p->windows = lru_w->next;
565 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
566 close(lru_p->pack_fd);
577 void release_pack_memory(size_t need, int fd)
579 size_t cur = pack_mapped;
580 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
584 void close_pack_windows(struct packed_git *p)
587 struct pack_window *w = p->windows;
590 die("pack '%s' still has open windows to it",
592 munmap(w->base, w->len);
593 pack_mapped -= w->len;
595 p->windows = w->next;
600 void unuse_pack(struct pack_window **w_cursor)
602 struct pack_window *w = *w_cursor;
609 void close_pack_index(struct packed_git *p)
612 munmap((void *)p->index_data, p->index_size);
613 p->index_data = NULL;
618 * This is used by git-repack in case a newly created pack happens to
619 * contain the same set of objects as an existing one. In that case
620 * the resulting file might be different even if its name would be the
621 * same. It is best to close any reference to the old pack before it is
622 * replaced on disk. Of course no index pointers nor windows for given pack
623 * must subsist at this point. If ever objects from this pack are requested
624 * again, the new version of the pack will be reinitialized through
625 * reprepare_packed_git().
627 void free_pack_by_name(const char *pack_name)
629 struct packed_git *p, **pp = &packed_git;
633 if (strcmp(pack_name, p->pack_name) == 0) {
634 clear_delta_base_cache();
635 close_pack_windows(p);
636 if (p->pack_fd != -1)
639 free(p->bad_object_sha1);
649 * Do not call this directly as this leaks p->pack_fd on error return;
650 * call open_packed_git() instead.
652 static int open_packed_git_1(struct packed_git *p)
655 struct pack_header hdr;
656 unsigned char sha1[20];
657 unsigned char *idx_sha1;
660 if (!p->index_data && open_pack_index(p))
661 return error("packfile %s index unavailable", p->pack_name);
663 p->pack_fd = open(p->pack_name, O_RDONLY);
664 while (p->pack_fd < 0 && errno == EMFILE && unuse_one_window(p, -1))
665 p->pack_fd = open(p->pack_name, O_RDONLY);
666 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
669 /* If we created the struct before we had the pack we lack size. */
671 if (!S_ISREG(st.st_mode))
672 return error("packfile %s not a regular file", p->pack_name);
673 p->pack_size = st.st_size;
674 } else if (p->pack_size != st.st_size)
675 return error("packfile %s size changed", p->pack_name);
677 /* We leave these file descriptors open with sliding mmap;
678 * there is no point keeping them open across exec(), though.
680 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
682 return error("cannot determine file descriptor flags");
683 fd_flag |= FD_CLOEXEC;
684 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
685 return error("cannot set FD_CLOEXEC");
687 /* Verify we recognize this pack file format. */
688 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
689 return error("file %s is far too short to be a packfile", p->pack_name);
690 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
691 return error("file %s is not a GIT packfile", p->pack_name);
692 if (!pack_version_ok(hdr.hdr_version))
693 return error("packfile %s is version %"PRIu32" and not"
694 " supported (try upgrading GIT to a newer version)",
695 p->pack_name, ntohl(hdr.hdr_version));
697 /* Verify the pack matches its index. */
698 if (p->num_objects != ntohl(hdr.hdr_entries))
699 return error("packfile %s claims to have %"PRIu32" objects"
700 " while index indicates %"PRIu32" objects",
701 p->pack_name, ntohl(hdr.hdr_entries),
703 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
704 return error("end of packfile %s is unavailable", p->pack_name);
705 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
706 return error("packfile %s signature is unavailable", p->pack_name);
707 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
708 if (hashcmp(sha1, idx_sha1))
709 return error("packfile %s does not match index", p->pack_name);
713 static int open_packed_git(struct packed_git *p)
715 if (!open_packed_git_1(p))
717 if (p->pack_fd != -1) {
724 static int in_window(struct pack_window *win, off_t offset)
726 /* We must promise at least 20 bytes (one hash) after the
727 * offset is available from this window, otherwise the offset
728 * is not actually in this window and a different window (which
729 * has that one hash excess) must be used. This is to support
730 * the object header and delta base parsing routines below.
732 off_t win_off = win->offset;
733 return win_off <= offset
734 && (offset + 20) <= (win_off + win->len);
737 unsigned char *use_pack(struct packed_git *p,
738 struct pack_window **w_cursor,
742 struct pack_window *win = *w_cursor;
744 if (p->pack_fd == -1 && open_packed_git(p))
745 die("packfile %s cannot be accessed", p->pack_name);
747 /* Since packfiles end in a hash of their content and it's
748 * pointless to ask for an offset into the middle of that
749 * hash, and the in_window function above wouldn't match
750 * don't allow an offset too close to the end of the file.
752 if (offset > (p->pack_size - 20))
753 die("offset beyond end of packfile (truncated pack?)");
755 if (!win || !in_window(win, offset)) {
758 for (win = p->windows; win; win = win->next) {
759 if (in_window(win, offset))
763 size_t window_align = packed_git_window_size / 2;
765 win = xcalloc(1, sizeof(*win));
766 win->offset = (offset / window_align) * window_align;
767 len = p->pack_size - win->offset;
768 if (len > packed_git_window_size)
769 len = packed_git_window_size;
770 win->len = (size_t)len;
771 pack_mapped += win->len;
772 while (packed_git_limit < pack_mapped
773 && unuse_one_window(p, p->pack_fd))
775 win->base = xmmap(NULL, win->len,
776 PROT_READ, MAP_PRIVATE,
777 p->pack_fd, win->offset);
778 if (win->base == MAP_FAILED)
779 die("packfile %s cannot be mapped: %s",
784 if (pack_mapped > peak_pack_mapped)
785 peak_pack_mapped = pack_mapped;
786 if (pack_open_windows > peak_pack_open_windows)
787 peak_pack_open_windows = pack_open_windows;
788 win->next = p->windows;
792 if (win != *w_cursor) {
793 win->last_used = pack_used_ctr++;
797 offset -= win->offset;
799 *left = win->len - xsize_t(offset);
800 return win->base + offset;
803 static struct packed_git *alloc_packed_git(int extra)
805 struct packed_git *p = xmalloc(sizeof(*p) + extra);
806 memset(p, 0, sizeof(*p));
811 struct packed_git *add_packed_git(const char *path, int path_len, int local)
814 struct packed_git *p = alloc_packed_git(path_len + 2);
817 * Make sure a corresponding .pack file exists and that
818 * the index looks sane.
820 path_len -= strlen(".idx");
825 memcpy(p->pack_name, path, path_len);
827 strcpy(p->pack_name + path_len, ".keep");
828 if (!access(p->pack_name, F_OK))
831 strcpy(p->pack_name + path_len, ".pack");
832 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
837 /* ok, it looks sane as far as we can check without
838 * actually mapping the pack file.
840 p->pack_size = st.st_size;
841 p->pack_local = local;
842 p->mtime = st.st_mtime;
843 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
848 struct packed_git *parse_pack_index(unsigned char *sha1)
850 const char *idx_path = sha1_pack_index_name(sha1);
851 const char *path = sha1_pack_name(sha1);
852 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
854 strcpy(p->pack_name, path);
855 hashcpy(p->sha1, sha1);
856 if (check_packed_git_idx(idx_path, p)) {
864 void install_packed_git(struct packed_git *pack)
866 pack->next = packed_git;
870 static void prepare_packed_git_one(char *objdir, int local)
872 /* Ensure that this buffer is large enough so that we can
873 append "/pack/" without clobbering the stack even if
874 strlen(objdir) were PATH_MAX. */
875 char path[PATH_MAX + 1 + 4 + 1 + 1];
880 sprintf(path, "%s/pack", objdir);
883 while (!dir && errno == EMFILE && unuse_one_window(packed_git, -1))
887 error("unable to open object pack directory: %s: %s",
888 path, strerror(errno));
892 while ((de = readdir(dir)) != NULL) {
893 int namelen = strlen(de->d_name);
894 struct packed_git *p;
896 if (!has_extension(de->d_name, ".idx"))
899 if (len + namelen + 1 > sizeof(path))
902 /* Don't reopen a pack we already have. */
903 strcpy(path + len, de->d_name);
904 for (p = packed_git; p; p = p->next) {
905 if (!memcmp(path, p->pack_name, len + namelen - 4))
910 /* See if it really is a valid .idx file with corresponding
911 * .pack file that we can map.
913 p = add_packed_git(path, len + namelen, local);
916 install_packed_git(p);
921 static int sort_pack(const void *a_, const void *b_)
923 struct packed_git *a = *((struct packed_git **)a_);
924 struct packed_git *b = *((struct packed_git **)b_);
928 * Local packs tend to contain objects specific to our
929 * variant of the project than remote ones. In addition,
930 * remote ones could be on a network mounted filesystem.
931 * Favor local ones for these reasons.
933 st = a->pack_local - b->pack_local;
938 * Younger packs tend to contain more recent objects,
939 * and more recent objects tend to get accessed more
942 if (a->mtime < b->mtime)
944 else if (a->mtime == b->mtime)
949 static void rearrange_packed_git(void)
951 struct packed_git **ary, *p;
954 for (n = 0, p = packed_git; p; p = p->next)
959 /* prepare an array of packed_git for easier sorting */
960 ary = xcalloc(n, sizeof(struct packed_git *));
961 for (n = 0, p = packed_git; p; p = p->next)
964 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
966 /* link them back again */
967 for (i = 0; i < n - 1; i++)
968 ary[i]->next = ary[i + 1];
969 ary[n - 1]->next = NULL;
975 static int prepare_packed_git_run_once = 0;
976 void prepare_packed_git(void)
978 struct alternate_object_database *alt;
980 if (prepare_packed_git_run_once)
982 prepare_packed_git_one(get_object_directory(), 1);
984 for (alt = alt_odb_list; alt; alt = alt->next) {
986 prepare_packed_git_one(alt->base, 0);
989 rearrange_packed_git();
990 prepare_packed_git_run_once = 1;
993 void reprepare_packed_git(void)
996 prepare_packed_git_run_once = 0;
997 prepare_packed_git();
1000 static void mark_bad_packed_object(struct packed_git *p,
1001 const unsigned char *sha1)
1004 for (i = 0; i < p->num_bad_objects; i++)
1005 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1007 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1008 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1009 p->num_bad_objects++;
1012 static int has_packed_and_bad(const unsigned char *sha1)
1014 struct packed_git *p;
1017 for (p = packed_git; p; p = p->next)
1018 for (i = 0; i < p->num_bad_objects; i++)
1019 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1024 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
1026 unsigned char real_sha1[20];
1027 hash_sha1_file(map, size, type, real_sha1);
1028 return hashcmp(sha1, real_sha1) ? -1 : 0;
1031 static int git_open_noatime(const char *name)
1033 static int sha1_file_open_flag = O_NOATIME;
1034 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1036 /* Might the failure be due to O_NOATIME? */
1037 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1038 fd = open(name, O_RDONLY);
1040 sha1_file_open_flag = 0;
1045 static int open_sha1_file(const unsigned char *sha1)
1048 char *name = sha1_file_name(sha1);
1049 struct alternate_object_database *alt;
1051 fd = git_open_noatime(name);
1057 for (alt = alt_odb_list; alt; alt = alt->next) {
1059 fill_sha1_path(name, sha1);
1060 fd = git_open_noatime(alt->base);
1067 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1072 fd = open_sha1_file(sha1);
1077 if (!fstat(fd, &st)) {
1078 *size = xsize_t(st.st_size);
1079 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1086 static int legacy_loose_object(unsigned char *map)
1091 * Is it a zlib-compressed buffer? If so, the first byte
1092 * must be 0x78 (15-bit window size, deflated), and the
1093 * first 16-bit word is evenly divisible by 31
1095 word = (map[0] << 8) + map[1];
1096 if (map[0] == 0x78 && !(word % 31))
1102 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1103 unsigned long len, enum object_type *type, unsigned long *sizep)
1106 unsigned long size, c;
1107 unsigned long used = 0;
1110 *type = (c >> 4) & 7;
1114 if (len <= used || bitsizeof(long) <= shift) {
1115 error("bad object header");
1119 size += (c & 0x7f) << shift;
1126 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1128 unsigned long size, used;
1129 static const char valid_loose_object_type[8] = {
1131 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1132 0, /* "delta" and others are invalid in a loose object */
1134 enum object_type type;
1136 /* Get the data stream */
1137 memset(stream, 0, sizeof(*stream));
1138 stream->next_in = map;
1139 stream->avail_in = mapsize;
1140 stream->next_out = buffer;
1141 stream->avail_out = bufsiz;
1143 if (legacy_loose_object(map)) {
1144 git_inflate_init(stream);
1145 return git_inflate(stream, 0);
1150 * There used to be a second loose object header format which
1151 * was meant to mimic the in-pack format, allowing for direct
1152 * copy of the object data. This format turned up not to be
1153 * really worth it and we don't write it any longer. But we
1154 * can still read it.
1156 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1157 if (!used || !valid_loose_object_type[type])
1162 /* Set up the stream for the rest.. */
1163 stream->next_in = map;
1164 stream->avail_in = mapsize;
1165 git_inflate_init(stream);
1167 /* And generate the fake traditional header */
1168 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1169 typename(type), size);
1173 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1175 int bytes = strlen(buffer) + 1;
1176 unsigned char *buf = xmallocz(size);
1180 n = stream->total_out - bytes;
1183 memcpy(buf, (char *) buffer + bytes, n);
1185 if (bytes <= size) {
1187 * The above condition must be (bytes <= size), not
1188 * (bytes < size). In other words, even though we
1189 * expect no more output and set avail_out to zer0,
1190 * the input zlib stream may have bytes that express
1191 * "this concludes the stream", and we *do* want to
1194 * Otherwise we would not be able to test that we
1195 * consumed all the input to reach the expected size;
1196 * we also want to check that zlib tells us that all
1197 * went well with status == Z_STREAM_END at the end.
1199 stream->next_out = buf + bytes;
1200 stream->avail_out = size - bytes;
1201 while (status == Z_OK)
1202 status = git_inflate(stream, Z_FINISH);
1204 if (status == Z_STREAM_END && !stream->avail_in) {
1205 git_inflate_end(stream);
1210 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1211 else if (stream->avail_in)
1212 error("garbage at end of loose object '%s'",
1219 * We used to just use "sscanf()", but that's actually way
1220 * too permissive for what we want to check. So do an anal
1221 * object header parse by hand.
1223 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1230 * The type can be at most ten bytes (including the
1231 * terminating '\0' that we add), and is followed by
1240 if (i >= sizeof(type))
1246 * The length must follow immediately, and be in canonical
1247 * decimal format (ie "010" is not valid).
1249 size = *hdr++ - '0';
1254 unsigned long c = *hdr - '0';
1258 size = size * 10 + c;
1264 * The length must be followed by a zero byte
1266 return *hdr ? -1 : type_from_string(type);
1269 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1275 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1276 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1279 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1282 unsigned long get_size_from_delta(struct packed_git *p,
1283 struct pack_window **w_curs,
1286 const unsigned char *data;
1287 unsigned char delta_head[20], *in;
1291 memset(&stream, 0, sizeof(stream));
1292 stream.next_out = delta_head;
1293 stream.avail_out = sizeof(delta_head);
1295 git_inflate_init(&stream);
1297 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1298 stream.next_in = in;
1299 st = git_inflate(&stream, Z_FINISH);
1300 curpos += stream.next_in - in;
1301 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1302 stream.total_out < sizeof(delta_head));
1303 git_inflate_end(&stream);
1304 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1305 error("delta data unpack-initial failed");
1309 /* Examine the initial part of the delta to figure out
1314 /* ignore base size */
1315 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1317 /* Read the result size */
1318 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1321 static off_t get_delta_base(struct packed_git *p,
1322 struct pack_window **w_curs,
1324 enum object_type type,
1325 off_t delta_obj_offset)
1327 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1330 /* use_pack() assured us we have [base_info, base_info + 20)
1331 * as a range that we can look at without walking off the
1332 * end of the mapped window. Its actually the hash size
1333 * that is assured. An OFS_DELTA longer than the hash size
1334 * is stupid, as then a REF_DELTA would be smaller to store.
1336 if (type == OBJ_OFS_DELTA) {
1338 unsigned char c = base_info[used++];
1339 base_offset = c & 127;
1342 if (!base_offset || MSB(base_offset, 7))
1343 return 0; /* overflow */
1344 c = base_info[used++];
1345 base_offset = (base_offset << 7) + (c & 127);
1347 base_offset = delta_obj_offset - base_offset;
1348 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1349 return 0; /* out of bound */
1351 } else if (type == OBJ_REF_DELTA) {
1352 /* The base entry _must_ be in the same pack */
1353 base_offset = find_pack_entry_one(base_info, p);
1356 die("I am totally screwed");
1360 /* forward declaration for a mutually recursive function */
1361 static int packed_object_info(struct packed_git *p, off_t offset,
1362 unsigned long *sizep);
1364 static int packed_delta_info(struct packed_git *p,
1365 struct pack_window **w_curs,
1367 enum object_type type,
1369 unsigned long *sizep)
1373 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1376 type = packed_object_info(p, base_offset, NULL);
1377 if (type <= OBJ_NONE) {
1378 struct revindex_entry *revidx;
1379 const unsigned char *base_sha1;
1380 revidx = find_pack_revindex(p, base_offset);
1383 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1384 mark_bad_packed_object(p, base_sha1);
1385 type = sha1_object_info(base_sha1, NULL);
1386 if (type <= OBJ_NONE)
1390 /* We choose to only get the type of the base object and
1391 * ignore potentially corrupt pack file that expects the delta
1392 * based on a base with a wrong size. This saves tons of
1396 *sizep = get_size_from_delta(p, w_curs, curpos);
1404 static int unpack_object_header(struct packed_git *p,
1405 struct pack_window **w_curs,
1407 unsigned long *sizep)
1409 unsigned char *base;
1412 enum object_type type;
1414 /* use_pack() assures us we have [base, base + 20) available
1415 * as a range that we can look at at. (Its actually the hash
1416 * size that is assured.) With our object header encoding
1417 * the maximum deflated object size is 2^137, which is just
1418 * insane, so we know won't exceed what we have been given.
1420 base = use_pack(p, w_curs, *curpos, &left);
1421 used = unpack_object_header_buffer(base, left, &type, sizep);
1430 const char *packed_object_info_detail(struct packed_git *p,
1432 unsigned long *size,
1433 unsigned long *store_size,
1434 unsigned int *delta_chain_length,
1435 unsigned char *base_sha1)
1437 struct pack_window *w_curs = NULL;
1439 unsigned long dummy;
1440 unsigned char *next_sha1;
1441 enum object_type type;
1442 struct revindex_entry *revidx;
1444 *delta_chain_length = 0;
1445 curpos = obj_offset;
1446 type = unpack_object_header(p, &w_curs, &curpos, size);
1448 revidx = find_pack_revindex(p, obj_offset);
1449 *store_size = revidx[1].offset - obj_offset;
1454 die("pack %s contains unknown object type %d",
1455 p->pack_name, type);
1460 unuse_pack(&w_curs);
1461 return typename(type);
1463 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1465 die("pack %s contains bad delta base reference of type %s",
1466 p->pack_name, typename(type));
1467 if (*delta_chain_length == 0) {
1468 revidx = find_pack_revindex(p, obj_offset);
1469 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
1473 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1474 if (*delta_chain_length == 0)
1475 hashcpy(base_sha1, next_sha1);
1476 obj_offset = find_pack_entry_one(next_sha1, p);
1479 (*delta_chain_length)++;
1480 curpos = obj_offset;
1481 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1485 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1486 unsigned long *sizep)
1488 struct pack_window *w_curs = NULL;
1490 off_t curpos = obj_offset;
1491 enum object_type type;
1493 type = unpack_object_header(p, &w_curs, &curpos, &size);
1498 type = packed_delta_info(p, &w_curs, curpos,
1499 type, obj_offset, sizep);
1509 error("unknown object type %i at offset %"PRIuMAX" in %s",
1510 type, (uintmax_t)obj_offset, p->pack_name);
1513 unuse_pack(&w_curs);
1517 static void *unpack_compressed_entry(struct packed_git *p,
1518 struct pack_window **w_curs,
1524 unsigned char *buffer, *in;
1526 buffer = xmallocz(size);
1527 memset(&stream, 0, sizeof(stream));
1528 stream.next_out = buffer;
1529 stream.avail_out = size + 1;
1531 git_inflate_init(&stream);
1533 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1534 stream.next_in = in;
1535 st = git_inflate(&stream, Z_FINISH);
1536 if (!stream.avail_out)
1537 break; /* the payload is larger than it should be */
1538 curpos += stream.next_in - in;
1539 } while (st == Z_OK || st == Z_BUF_ERROR);
1540 git_inflate_end(&stream);
1541 if ((st != Z_STREAM_END) || stream.total_out != size) {
1549 #define MAX_DELTA_CACHE (256)
1551 static size_t delta_base_cached;
1553 static struct delta_base_cache_lru_list {
1554 struct delta_base_cache_lru_list *prev;
1555 struct delta_base_cache_lru_list *next;
1556 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1558 static struct delta_base_cache_entry {
1559 struct delta_base_cache_lru_list lru;
1561 struct packed_git *p;
1564 enum object_type type;
1565 } delta_base_cache[MAX_DELTA_CACHE];
1567 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1571 hash = (unsigned long)p + (unsigned long)base_offset;
1572 hash += (hash >> 8) + (hash >> 16);
1573 return hash % MAX_DELTA_CACHE;
1576 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1577 unsigned long *base_size, enum object_type *type, int keep_cache)
1580 unsigned long hash = pack_entry_hash(p, base_offset);
1581 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1584 if (!ret || ent->p != p || ent->base_offset != base_offset)
1585 return unpack_entry(p, base_offset, type, base_size);
1589 ent->lru.next->prev = ent->lru.prev;
1590 ent->lru.prev->next = ent->lru.next;
1591 delta_base_cached -= ent->size;
1593 ret = xmemdupz(ent->data, ent->size);
1596 *base_size = ent->size;
1600 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1605 ent->lru.next->prev = ent->lru.prev;
1606 ent->lru.prev->next = ent->lru.next;
1607 delta_base_cached -= ent->size;
1611 void clear_delta_base_cache(void)
1614 for (p = 0; p < MAX_DELTA_CACHE; p++)
1615 release_delta_base_cache(&delta_base_cache[p]);
1618 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1619 void *base, unsigned long base_size, enum object_type type)
1621 unsigned long hash = pack_entry_hash(p, base_offset);
1622 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1623 struct delta_base_cache_lru_list *lru;
1625 release_delta_base_cache(ent);
1626 delta_base_cached += base_size;
1628 for (lru = delta_base_cache_lru.next;
1629 delta_base_cached > delta_base_cache_limit
1630 && lru != &delta_base_cache_lru;
1632 struct delta_base_cache_entry *f = (void *)lru;
1633 if (f->type == OBJ_BLOB)
1634 release_delta_base_cache(f);
1636 for (lru = delta_base_cache_lru.next;
1637 delta_base_cached > delta_base_cache_limit
1638 && lru != &delta_base_cache_lru;
1640 struct delta_base_cache_entry *f = (void *)lru;
1641 release_delta_base_cache(f);
1645 ent->base_offset = base_offset;
1648 ent->size = base_size;
1649 ent->lru.next = &delta_base_cache_lru;
1650 ent->lru.prev = delta_base_cache_lru.prev;
1651 delta_base_cache_lru.prev->next = &ent->lru;
1652 delta_base_cache_lru.prev = &ent->lru;
1655 static void *read_object(const unsigned char *sha1, enum object_type *type,
1656 unsigned long *size);
1658 static void *unpack_delta_entry(struct packed_git *p,
1659 struct pack_window **w_curs,
1661 unsigned long delta_size,
1663 enum object_type *type,
1664 unsigned long *sizep)
1666 void *delta_data, *result, *base;
1667 unsigned long base_size;
1670 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1672 error("failed to validate delta base reference "
1673 "at offset %"PRIuMAX" from %s",
1674 (uintmax_t)curpos, p->pack_name);
1678 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1681 * We're probably in deep shit, but let's try to fetch
1682 * the required base anyway from another pack or loose.
1683 * This is costly but should happen only in the presence
1684 * of a corrupted pack, and is better than failing outright.
1686 struct revindex_entry *revidx;
1687 const unsigned char *base_sha1;
1688 revidx = find_pack_revindex(p, base_offset);
1691 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1692 error("failed to read delta base object %s"
1693 " at offset %"PRIuMAX" from %s",
1694 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1696 mark_bad_packed_object(p, base_sha1);
1697 base = read_object(base_sha1, type, &base_size);
1702 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1704 error("failed to unpack compressed delta "
1705 "at offset %"PRIuMAX" from %s",
1706 (uintmax_t)curpos, p->pack_name);
1710 result = patch_delta(base, base_size,
1711 delta_data, delta_size,
1714 die("failed to apply delta");
1716 add_delta_base_cache(p, base_offset, base, base_size, *type);
1720 int do_check_packed_object_crc;
1722 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1723 enum object_type *type, unsigned long *sizep)
1725 struct pack_window *w_curs = NULL;
1726 off_t curpos = obj_offset;
1729 if (do_check_packed_object_crc && p->index_version > 1) {
1730 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1731 unsigned long len = revidx[1].offset - obj_offset;
1732 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1733 const unsigned char *sha1 =
1734 nth_packed_object_sha1(p, revidx->nr);
1735 error("bad packed object CRC for %s",
1737 mark_bad_packed_object(p, sha1);
1738 unuse_pack(&w_curs);
1743 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1747 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1748 obj_offset, type, sizep);
1754 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1758 error("unknown object type %i at offset %"PRIuMAX" in %s",
1759 *type, (uintmax_t)obj_offset, p->pack_name);
1761 unuse_pack(&w_curs);
1765 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1768 const unsigned char *index = p->index_data;
1770 if (open_pack_index(p))
1772 index = p->index_data;
1774 if (n >= p->num_objects)
1777 if (p->index_version == 1) {
1778 return index + 24 * n + 4;
1781 return index + 20 * n;
1785 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1787 const unsigned char *index = p->index_data;
1789 if (p->index_version == 1) {
1790 return ntohl(*((uint32_t *)(index + 24 * n)));
1793 index += 8 + p->num_objects * (20 + 4);
1794 off = ntohl(*((uint32_t *)(index + 4 * n)));
1795 if (!(off & 0x80000000))
1797 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1798 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1799 ntohl(*((uint32_t *)(index + 4)));
1803 off_t find_pack_entry_one(const unsigned char *sha1,
1804 struct packed_git *p)
1806 const uint32_t *level1_ofs = p->index_data;
1807 const unsigned char *index = p->index_data;
1808 unsigned hi, lo, stride;
1809 static int use_lookup = -1;
1810 static int debug_lookup = -1;
1812 if (debug_lookup < 0)
1813 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
1816 if (open_pack_index(p))
1818 level1_ofs = p->index_data;
1819 index = p->index_data;
1821 if (p->index_version > 1) {
1826 hi = ntohl(level1_ofs[*sha1]);
1827 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1828 if (p->index_version > 1) {
1836 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
1837 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1840 use_lookup = !!getenv("GIT_USE_LOOKUP");
1842 int pos = sha1_entry_pos(index, stride, 0,
1843 lo, hi, p->num_objects, sha1);
1846 return nth_packed_object_offset(p, pos);
1850 unsigned mi = (lo + hi) / 2;
1851 int cmp = hashcmp(index + mi * stride, sha1);
1854 printf("lo %u hi %u rg %u mi %u\n",
1855 lo, hi, hi - lo, mi);
1857 return nth_packed_object_offset(p, mi);
1866 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1868 static struct packed_git *last_found = (void *)1;
1869 struct packed_git *p;
1872 prepare_packed_git();
1875 p = (last_found == (void *)1) ? packed_git : last_found;
1878 if (p->num_bad_objects) {
1880 for (i = 0; i < p->num_bad_objects; i++)
1881 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1885 offset = find_pack_entry_one(sha1, p);
1888 * We are about to tell the caller where they can
1889 * locate the requested object. We better make
1890 * sure the packfile is still here and can be
1891 * accessed before supplying that answer, as
1892 * it may have been deleted since the index
1895 if (p->pack_fd == -1 && open_packed_git(p)) {
1896 error("packfile %s cannot be accessed", p->pack_name);
1901 hashcpy(e->sha1, sha1);
1907 if (p == last_found)
1911 if (p == last_found)
1917 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1918 struct packed_git *packs)
1920 struct packed_git *p;
1922 for (p = packs; p; p = p->next) {
1923 if (find_pack_entry_one(sha1, p))
1930 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1933 unsigned long mapsize, size;
1938 map = map_sha1_file(sha1, &mapsize);
1940 return error("unable to find %s", sha1_to_hex(sha1));
1941 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1942 status = error("unable to unpack %s header",
1944 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1945 status = error("unable to parse %s header", sha1_to_hex(sha1));
1948 git_inflate_end(&stream);
1949 munmap(map, mapsize);
1953 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1955 struct pack_entry e;
1958 if (!find_pack_entry(sha1, &e)) {
1959 /* Most likely it's a loose object. */
1960 status = sha1_loose_object_info(sha1, sizep);
1964 /* Not a loose object; someone else may have just packed it. */
1965 reprepare_packed_git();
1966 if (!find_pack_entry(sha1, &e))
1970 status = packed_object_info(e.p, e.offset, sizep);
1972 mark_bad_packed_object(e.p, sha1);
1973 status = sha1_object_info(sha1, sizep);
1979 static void *read_packed_sha1(const unsigned char *sha1,
1980 enum object_type *type, unsigned long *size)
1982 struct pack_entry e;
1985 if (!find_pack_entry(sha1, &e))
1987 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1990 * We're probably in deep shit, but let's try to fetch
1991 * the required object anyway from another pack or loose.
1992 * This should happen only in the presence of a corrupted
1993 * pack, and is better than failing outright.
1995 error("failed to read object %s at offset %"PRIuMAX" from %s",
1996 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1997 mark_bad_packed_object(e.p, sha1);
1998 data = read_object(sha1, type, size);
2004 * This is meant to hold a *small* number of objects that you would
2005 * want read_sha1_file() to be able to return, but yet you do not want
2006 * to write them into the object store (e.g. a browse-only
2009 static struct cached_object {
2010 unsigned char sha1[20];
2011 enum object_type type;
2015 static int cached_object_nr, cached_object_alloc;
2017 static struct cached_object empty_tree = {
2018 EMPTY_TREE_SHA1_BIN,
2024 static struct cached_object *find_cached_object(const unsigned char *sha1)
2027 struct cached_object *co = cached_objects;
2029 for (i = 0; i < cached_object_nr; i++, co++) {
2030 if (!hashcmp(co->sha1, sha1))
2033 if (!hashcmp(sha1, empty_tree.sha1))
2038 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2039 unsigned char *sha1)
2041 struct cached_object *co;
2043 hash_sha1_file(buf, len, typename(type), sha1);
2044 if (has_sha1_file(sha1) || find_cached_object(sha1))
2046 if (cached_object_alloc <= cached_object_nr) {
2047 cached_object_alloc = alloc_nr(cached_object_alloc);
2048 cached_objects = xrealloc(cached_objects,
2049 sizeof(*cached_objects) *
2050 cached_object_alloc);
2052 co = &cached_objects[cached_object_nr++];
2055 co->buf = xmalloc(len);
2056 memcpy(co->buf, buf, len);
2057 hashcpy(co->sha1, sha1);
2061 static void *read_object(const unsigned char *sha1, enum object_type *type,
2062 unsigned long *size)
2064 unsigned long mapsize;
2066 struct cached_object *co;
2068 co = find_cached_object(sha1);
2072 return xmemdupz(co->buf, co->size);
2075 buf = read_packed_sha1(sha1, type, size);
2078 map = map_sha1_file(sha1, &mapsize);
2080 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2081 munmap(map, mapsize);
2084 reprepare_packed_git();
2085 return read_packed_sha1(sha1, type, size);
2088 void *read_sha1_file_repl(const unsigned char *sha1,
2089 enum object_type *type,
2090 unsigned long *size,
2091 const unsigned char **replacement)
2093 const unsigned char *repl = lookup_replace_object(sha1);
2094 void *data = read_object(repl, type, size);
2096 /* die if we replaced an object with one that does not exist */
2097 if (!data && repl != sha1)
2098 die("replacement %s not found for %s",
2099 sha1_to_hex(repl), sha1_to_hex(sha1));
2101 /* legacy behavior is to die on corrupted objects */
2102 if (!data && (has_loose_object(repl) || has_packed_and_bad(repl)))
2103 die("object %s is corrupted", sha1_to_hex(repl));
2106 *replacement = repl;
2111 void *read_object_with_reference(const unsigned char *sha1,
2112 const char *required_type_name,
2113 unsigned long *size,
2114 unsigned char *actual_sha1_return)
2116 enum object_type type, required_type;
2118 unsigned long isize;
2119 unsigned char actual_sha1[20];
2121 required_type = type_from_string(required_type_name);
2122 hashcpy(actual_sha1, sha1);
2124 int ref_length = -1;
2125 const char *ref_type = NULL;
2127 buffer = read_sha1_file(actual_sha1, &type, &isize);
2130 if (type == required_type) {
2132 if (actual_sha1_return)
2133 hashcpy(actual_sha1_return, actual_sha1);
2136 /* Handle references */
2137 else if (type == OBJ_COMMIT)
2139 else if (type == OBJ_TAG)
2140 ref_type = "object ";
2145 ref_length = strlen(ref_type);
2147 if (ref_length + 40 > isize ||
2148 memcmp(buffer, ref_type, ref_length) ||
2149 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2154 /* Now we have the ID of the referred-to object in
2155 * actual_sha1. Check again. */
2159 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2160 const char *type, unsigned char *sha1,
2161 char *hdr, int *hdrlen)
2165 /* Generate the header */
2166 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2170 git_SHA1_Update(&c, hdr, *hdrlen);
2171 git_SHA1_Update(&c, buf, len);
2172 git_SHA1_Final(sha1, &c);
2176 * Move the just written object into its final resting place.
2177 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2178 * "moving" is only a part of what it does, when no patch between
2179 * master to pu changes the call sites of this function.
2181 int move_temp_to_file(const char *tmpfile, const char *filename)
2185 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2187 else if (link(tmpfile, filename))
2191 * Coda hack - coda doesn't like cross-directory links,
2192 * so we fall back to a rename, which will mean that it
2193 * won't be able to check collisions, but that's not a
2196 * The same holds for FAT formatted media.
2198 * When this succeeds, we just return. We have nothing
2201 if (ret && ret != EEXIST) {
2203 if (!rename(tmpfile, filename))
2207 unlink_or_warn(tmpfile);
2209 if (ret != EEXIST) {
2210 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
2212 /* FIXME!!! Collision check here ? */
2216 if (adjust_shared_perm(filename))
2217 return error("unable to set permission to '%s'", filename);
2221 static int write_buffer(int fd, const void *buf, size_t len)
2223 if (write_in_full(fd, buf, len) < 0)
2224 return error("file write error (%s)", strerror(errno));
2228 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2229 unsigned char *sha1)
2233 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2237 /* Finalize a file on disk, and close it. */
2238 static void close_sha1_file(int fd)
2240 if (fsync_object_files)
2241 fsync_or_die(fd, "sha1 file");
2243 die_errno("error when closing sha1 file");
2246 /* Size of directory component, including the ending '/' */
2247 static inline int directory_size(const char *filename)
2249 const char *s = strrchr(filename, '/');
2252 return s - filename + 1;
2256 * This creates a temporary file in the same directory as the final
2259 * We want to avoid cross-directory filename renames, because those
2260 * can have problems on various filesystems (FAT, NFS, Coda).
2262 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2264 int fd, dirlen = directory_size(filename);
2266 if (dirlen + 20 > bufsiz) {
2267 errno = ENAMETOOLONG;
2270 memcpy(buffer, filename, dirlen);
2271 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2272 fd = git_mkstemp_mode(buffer, 0444);
2273 if (fd < 0 && dirlen && errno == ENOENT) {
2274 /* Make sure the directory exists */
2275 memcpy(buffer, filename, dirlen);
2276 buffer[dirlen-1] = 0;
2277 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2281 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2282 fd = git_mkstemp_mode(buffer, 0444);
2287 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2288 void *buf, unsigned long len, time_t mtime)
2291 unsigned char compressed[4096];
2294 unsigned char parano_sha1[20];
2296 static char tmpfile[PATH_MAX];
2298 filename = sha1_file_name(sha1);
2299 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2300 while (fd < 0 && errno == EMFILE && unuse_one_window(packed_git, -1))
2301 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2303 if (errno == EACCES)
2304 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2306 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2310 memset(&stream, 0, sizeof(stream));
2311 deflateInit(&stream, zlib_compression_level);
2312 stream.next_out = compressed;
2313 stream.avail_out = sizeof(compressed);
2316 /* First header.. */
2317 stream.next_in = (unsigned char *)hdr;
2318 stream.avail_in = hdrlen;
2319 while (deflate(&stream, 0) == Z_OK)
2321 git_SHA1_Update(&c, hdr, hdrlen);
2323 /* Then the data itself.. */
2324 stream.next_in = buf;
2325 stream.avail_in = len;
2327 unsigned char *in0 = stream.next_in;
2328 ret = deflate(&stream, Z_FINISH);
2329 git_SHA1_Update(&c, in0, stream.next_in - in0);
2330 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2331 die("unable to write sha1 file");
2332 stream.next_out = compressed;
2333 stream.avail_out = sizeof(compressed);
2334 } while (ret == Z_OK);
2336 if (ret != Z_STREAM_END)
2337 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2338 ret = deflateEnd(&stream);
2340 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2341 git_SHA1_Final(parano_sha1, &c);
2342 if (hashcmp(sha1, parano_sha1) != 0)
2343 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
2345 close_sha1_file(fd);
2350 utb.modtime = mtime;
2351 if (utime(tmpfile, &utb) < 0)
2352 warning("failed utime() on %s: %s",
2353 tmpfile, strerror(errno));
2356 return move_temp_to_file(tmpfile, filename);
2359 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2361 unsigned char sha1[20];
2365 /* Normally if we have it in the pack then we do not bother writing
2366 * it out into .git/objects/??/?{38} file.
2368 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2370 hashcpy(returnsha1, sha1);
2371 if (has_sha1_file(sha1))
2373 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2376 int force_object_loose(const unsigned char *sha1, time_t mtime)
2380 enum object_type type;
2385 if (has_loose_object(sha1))
2387 buf = read_packed_sha1(sha1, &type, &len);
2389 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2390 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2391 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2397 int has_pack_index(const unsigned char *sha1)
2400 if (stat(sha1_pack_index_name(sha1), &st))
2405 int has_sha1_pack(const unsigned char *sha1)
2407 struct pack_entry e;
2408 return find_pack_entry(sha1, &e);
2411 int has_sha1_file(const unsigned char *sha1)
2413 struct pack_entry e;
2415 if (find_pack_entry(sha1, &e))
2417 return has_loose_object(sha1);
2420 static int index_mem(unsigned char *sha1, void *buf, size_t size,
2421 int write_object, enum object_type type, const char *path)
2423 int ret, re_allocated = 0;
2429 * Convert blobs to git internal format
2431 if ((type == OBJ_BLOB) && path) {
2432 struct strbuf nbuf = STRBUF_INIT;
2433 if (convert_to_git(path, buf, size, &nbuf,
2434 write_object ? safe_crlf : 0)) {
2435 buf = strbuf_detach(&nbuf, &size);
2441 ret = write_sha1_file(buf, size, typename(type), sha1);
2443 ret = hash_sha1_file(buf, size, typename(type), sha1);
2449 #define SMALL_FILE_SIZE (32*1024)
2451 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2452 enum object_type type, const char *path)
2455 size_t size = xsize_t(st->st_size);
2457 if (!S_ISREG(st->st_mode)) {
2458 struct strbuf sbuf = STRBUF_INIT;
2459 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2460 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2464 strbuf_release(&sbuf);
2465 } else if (size <= SMALL_FILE_SIZE) {
2466 char *buf = xmalloc(size);
2467 if (size == read_in_full(fd, buf, size))
2468 ret = index_mem(sha1, buf, size, write_object, type,
2471 ret = error("short read %s", strerror(errno));
2474 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2475 ret = index_mem(sha1, buf, size, write_object, type, path);
2478 ret = index_mem(sha1, NULL, size, write_object, type, path);
2483 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2486 struct strbuf sb = STRBUF_INIT;
2488 switch (st->st_mode & S_IFMT) {
2490 fd = open(path, O_RDONLY);
2492 return error("open(\"%s\"): %s", path,
2494 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2495 return error("%s: failed to insert into database",
2499 if (strbuf_readlink(&sb, path, st->st_size)) {
2500 char *errstr = strerror(errno);
2501 return error("readlink(\"%s\"): %s", path,
2505 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2506 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
2507 return error("%s: failed to insert into database",
2509 strbuf_release(&sb);
2512 return resolve_gitlink_ref(path, "HEAD", sha1);
2514 return error("%s: unsupported file type", path);
2519 int read_pack_header(int fd, struct pack_header *header)
2521 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2522 /* "eof before pack header was fully read" */
2523 return PH_ERROR_EOF;
2525 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2526 /* "protocol error (pack signature mismatch detected)" */
2527 return PH_ERROR_PACK_SIGNATURE;
2528 if (!pack_version_ok(header->hdr_version))
2529 /* "protocol error (pack version unsupported)" */
2530 return PH_ERROR_PROTOCOL;