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 const signed char hexval_table[256] = {
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
42 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
45 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
46 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
47 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
51 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
68 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
69 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
70 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
73 int get_sha1_hex(const char *hex, unsigned char *sha1)
76 for (i = 0; i < 20; i++) {
77 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
86 int safe_create_leading_directories(char *path)
91 if (is_absolute_path(path))
95 pos = strchr(pos, '/');
99 if (!stat(path, &st)) {
101 if (!S_ISDIR(st.st_mode)) {
106 else if (mkdir(path, 0777)) {
110 else if (adjust_shared_perm(path)) {
119 char *sha1_to_hex(const unsigned char *sha1)
122 static char hexbuffer[4][50];
123 static const char hex[] = "0123456789abcdef";
124 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
127 for (i = 0; i < 20; i++) {
128 unsigned int val = *sha1++;
129 *buf++ = hex[val >> 4];
130 *buf++ = hex[val & 0xf];
137 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
140 for (i = 0; i < 20; i++) {
141 static char hex[] = "0123456789abcdef";
142 unsigned int val = sha1[i];
143 char *pos = pathbuf + i*2 + (i > 0);
144 *pos++ = hex[val >> 4];
145 *pos = hex[val & 0xf];
150 * NOTE! This returns a statically allocated buffer, so you have to be
151 * careful about using it. Do an "xstrdup()" if you need to save the
154 * Also note that this returns the location for creating. Reading
155 * SHA1 file can happen from any alternate directory listed in the
156 * DB_ENVIRONMENT environment variable if it is not found in
157 * the primary object database.
159 char *sha1_file_name(const unsigned char *sha1)
161 static char *name, *base;
164 const char *sha1_file_directory = get_object_directory();
165 int len = strlen(sha1_file_directory);
166 base = xmalloc(len + 60);
167 memcpy(base, sha1_file_directory, len);
168 memset(base+len, 0, 60);
171 name = base + len + 1;
173 fill_sha1_path(name, sha1);
177 static char *sha1_get_pack_name(const unsigned char *sha1,
178 char **name, char **base, const char *which)
180 static const char hex[] = "0123456789abcdef";
185 const char *sha1_file_directory = get_object_directory();
186 int len = strlen(sha1_file_directory);
187 *base = xmalloc(len + 60);
188 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
189 sha1_file_directory, which);
190 *name = *base + len + 11;
195 for (i = 0; i < 20; i++) {
196 unsigned int val = *sha1++;
197 *buf++ = hex[val >> 4];
198 *buf++ = hex[val & 0xf];
204 char *sha1_pack_name(const unsigned char *sha1)
206 static char *name, *base;
208 return sha1_get_pack_name(sha1, &name, &base, "pack");
211 char *sha1_pack_index_name(const unsigned char *sha1)
213 static char *name, *base;
215 return sha1_get_pack_name(sha1, &name, &base, "idx");
218 struct alternate_object_database *alt_odb_list;
219 static struct alternate_object_database **alt_odb_tail;
221 static void read_info_alternates(const char * alternates, int depth);
224 * Prepare alternate object database registry.
226 * The variable alt_odb_list points at the list of struct
227 * alternate_object_database. The elements on this list come from
228 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
229 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
230 * whose contents is similar to that environment variable but can be
231 * LF separated. Its base points at a statically allocated buffer that
232 * contains "/the/directory/corresponding/to/.git/objects/...", while
233 * its name points just after the slash at the end of ".git/objects/"
234 * in the example above, and has enough space to hold 40-byte hex
235 * SHA1, an extra slash for the first level indirection, and the
238 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
241 const char *objdir = get_object_directory();
242 struct alternate_object_database *ent;
243 struct alternate_object_database *alt;
244 /* 43 = 40-byte + 2 '/' + terminating NUL */
246 int entlen = pfxlen + 43;
249 if (!is_absolute_path(entry) && relative_base) {
250 /* Relative alt-odb */
252 base_len = strlen(relative_base) + 1;
256 ent = xmalloc(sizeof(*ent) + entlen);
258 if (!is_absolute_path(entry) && relative_base) {
259 memcpy(ent->base, relative_base, base_len - 1);
260 ent->base[base_len - 1] = '/';
261 memcpy(ent->base + base_len, entry, len);
264 memcpy(ent->base, entry, pfxlen);
266 ent->name = ent->base + pfxlen + 1;
267 ent->base[pfxlen + 3] = '/';
268 ent->base[pfxlen] = ent->base[entlen-1] = 0;
270 /* Detect cases where alternate disappeared */
271 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
272 error("object directory %s does not exist; "
273 "check .git/objects/info/alternates.",
279 /* Prevent the common mistake of listing the same
280 * thing twice, or object directory itself.
282 for (alt = alt_odb_list; alt; alt = alt->next) {
283 if (!memcmp(ent->base, alt->base, pfxlen)) {
288 if (!memcmp(ent->base, objdir, pfxlen)) {
293 /* add the alternate entry */
295 alt_odb_tail = &(ent->next);
298 /* recursively add alternates */
299 read_info_alternates(ent->base, depth + 1);
301 ent->base[pfxlen] = '/';
306 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
307 const char *relative_base, int depth)
309 const char *cp, *last;
312 error("%s: ignoring alternate object stores, nesting too deep.",
320 if (cp < ep && *cp == '#') {
321 while (cp < ep && *cp != sep)
326 while (cp < ep && *cp != sep)
329 if (!is_absolute_path(last) && depth) {
330 error("%s: ignoring relative alternate object store %s",
331 relative_base, last);
333 link_alt_odb_entry(last, cp - last,
334 relative_base, depth);
337 while (cp < ep && *cp == sep)
343 static void read_info_alternates(const char * relative_base, int depth)
348 const char alt_file_name[] = "info/alternates";
349 /* Given that relative_base is no longer than PATH_MAX,
350 ensure that "path" has enough space to append "/", the
351 file name, "info/alternates", and a trailing NUL. */
352 char path[PATH_MAX + 1 + sizeof alt_file_name];
355 sprintf(path, "%s/%s", relative_base, alt_file_name);
356 fd = open(path, O_RDONLY);
359 if (fstat(fd, &st) || (st.st_size == 0)) {
363 mapsz = xsize_t(st.st_size);
364 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
367 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
372 void add_to_alternates_file(const char *reference)
374 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
375 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), 1);
376 char *alt = mkpath("%s/objects\n", reference);
377 write_or_die(fd, alt, strlen(alt));
378 if (commit_lock_file(lock))
379 die("could not close alternates file");
381 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
384 void prepare_alt_odb(void)
391 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
394 alt_odb_tail = &alt_odb_list;
395 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
397 read_info_alternates(get_object_directory(), 0);
400 static int has_loose_object(const unsigned char *sha1)
402 char *name = sha1_file_name(sha1);
403 struct alternate_object_database *alt;
405 if (!access(name, F_OK))
408 for (alt = alt_odb_list; alt; alt = alt->next) {
410 fill_sha1_path(name, sha1);
411 if (!access(alt->base, F_OK))
417 static unsigned int pack_used_ctr;
418 static unsigned int pack_mmap_calls;
419 static unsigned int peak_pack_open_windows;
420 static unsigned int pack_open_windows;
421 static size_t peak_pack_mapped;
422 static size_t pack_mapped;
423 struct packed_git *packed_git;
425 void pack_report(void)
428 "pack_report: getpagesize() = %10" SZ_FMT "\n"
429 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
430 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
431 sz_fmt(getpagesize()),
432 sz_fmt(packed_git_window_size),
433 sz_fmt(packed_git_limit));
435 "pack_report: pack_used_ctr = %10u\n"
436 "pack_report: pack_mmap_calls = %10u\n"
437 "pack_report: pack_open_windows = %10u / %10u\n"
438 "pack_report: pack_mapped = "
439 "%10" SZ_FMT " / %10" SZ_FMT "\n",
442 pack_open_windows, peak_pack_open_windows,
443 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
446 static int check_packed_git_idx(const char *path, struct packed_git *p)
449 struct pack_idx_header *hdr;
451 uint32_t version, nr, i, *index;
452 int fd = open(path, O_RDONLY);
457 if (fstat(fd, &st)) {
461 idx_size = xsize_t(st.st_size);
462 if (idx_size < 4 * 256 + 20 + 20) {
464 return error("index file %s is too small", path);
466 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
470 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
471 version = ntohl(hdr->idx_version);
472 if (version < 2 || version > 2) {
473 munmap(idx_map, idx_size);
474 return error("index file %s is version %d"
475 " and is not supported by this binary"
476 " (try upgrading GIT to a newer version)",
485 index += 2; /* skip index header */
486 for (i = 0; i < 256; i++) {
487 uint32_t n = ntohl(index[i]);
489 munmap(idx_map, idx_size);
490 return error("non-monotonic index %s", path);
498 * - 256 index entries 4 bytes each
499 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
500 * - 20-byte SHA1 of the packfile
501 * - 20-byte SHA1 file checksum
503 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
504 munmap(idx_map, idx_size);
505 return error("wrong index v1 file size in %s", path);
507 } else if (version == 2) {
510 * - 8 bytes of header
511 * - 256 index entries 4 bytes each
512 * - 20-byte sha1 entry * nr
513 * - 4-byte crc entry * nr
514 * - 4-byte offset entry * nr
515 * - 20-byte SHA1 of the packfile
516 * - 20-byte SHA1 file checksum
517 * And after the 4-byte offset table might be a
518 * variable sized table containing 8-byte entries
519 * for offsets larger than 2^31.
521 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
522 unsigned long max_size = min_size;
524 max_size += (nr - 1)*8;
525 if (idx_size < min_size || idx_size > max_size) {
526 munmap(idx_map, idx_size);
527 return error("wrong index v2 file size in %s", path);
529 if (idx_size != min_size &&
531 * make sure we can deal with large pack offsets.
532 * 31-bit signed offset won't be enough, neither
533 * 32-bit unsigned one will be.
535 (sizeof(off_t) <= 4)) {
536 munmap(idx_map, idx_size);
537 return error("pack too large for current definition of off_t in %s", path);
541 p->index_version = version;
542 p->index_data = idx_map;
543 p->index_size = idx_size;
548 int open_pack_index(struct packed_git *p)
556 idx_name = xstrdup(p->pack_name);
557 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
558 ret = check_packed_git_idx(idx_name, p);
563 static void scan_windows(struct packed_git *p,
564 struct packed_git **lru_p,
565 struct pack_window **lru_w,
566 struct pack_window **lru_l)
568 struct pack_window *w, *w_l;
570 for (w_l = NULL, w = p->windows; w; w = w->next) {
572 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
582 static int unuse_one_window(struct packed_git *current, int keep_fd)
584 struct packed_git *p, *lru_p = NULL;
585 struct pack_window *lru_w = NULL, *lru_l = NULL;
588 scan_windows(current, &lru_p, &lru_w, &lru_l);
589 for (p = packed_git; p; p = p->next)
590 scan_windows(p, &lru_p, &lru_w, &lru_l);
592 munmap(lru_w->base, lru_w->len);
593 pack_mapped -= lru_w->len;
595 lru_l->next = lru_w->next;
597 lru_p->windows = lru_w->next;
598 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
599 close(lru_p->pack_fd);
610 void release_pack_memory(size_t need, int fd)
612 size_t cur = pack_mapped;
613 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
617 void close_pack_windows(struct packed_git *p)
620 struct pack_window *w = p->windows;
623 die("pack '%s' still has open windows to it",
625 munmap(w->base, w->len);
626 pack_mapped -= w->len;
628 p->windows = w->next;
633 void unuse_pack(struct pack_window **w_cursor)
635 struct pack_window *w = *w_cursor;
643 * Do not call this directly as this leaks p->pack_fd on error return;
644 * call open_packed_git() instead.
646 static int open_packed_git_1(struct packed_git *p)
649 struct pack_header hdr;
650 unsigned char sha1[20];
651 unsigned char *idx_sha1;
654 if (!p->index_data && open_pack_index(p))
655 return error("packfile %s index unavailable", p->pack_name);
657 p->pack_fd = open(p->pack_name, O_RDONLY);
658 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
661 /* If we created the struct before we had the pack we lack size. */
663 if (!S_ISREG(st.st_mode))
664 return error("packfile %s not a regular file", p->pack_name);
665 p->pack_size = st.st_size;
666 } else if (p->pack_size != st.st_size)
667 return error("packfile %s size changed", p->pack_name);
669 /* We leave these file descriptors open with sliding mmap;
670 * there is no point keeping them open across exec(), though.
672 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
674 return error("cannot determine file descriptor flags");
675 fd_flag |= FD_CLOEXEC;
676 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
677 return error("cannot set FD_CLOEXEC");
679 /* Verify we recognize this pack file format. */
680 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
681 return error("file %s is far too short to be a packfile", p->pack_name);
682 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
683 return error("file %s is not a GIT packfile", p->pack_name);
684 if (!pack_version_ok(hdr.hdr_version))
685 return error("packfile %s is version %u and not supported"
686 " (try upgrading GIT to a newer version)",
687 p->pack_name, ntohl(hdr.hdr_version));
689 /* Verify the pack matches its index. */
690 if (p->num_objects != ntohl(hdr.hdr_entries))
691 return error("packfile %s claims to have %u objects"
692 " while index indicates %u objects",
693 p->pack_name, ntohl(hdr.hdr_entries),
695 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
696 return error("end of packfile %s is unavailable", p->pack_name);
697 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
698 return error("packfile %s signature is unavailable", p->pack_name);
699 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
700 if (hashcmp(sha1, idx_sha1))
701 return error("packfile %s does not match index", p->pack_name);
705 static int open_packed_git(struct packed_git *p)
707 if (!open_packed_git_1(p))
709 if (p->pack_fd != -1) {
716 static int in_window(struct pack_window *win, off_t offset)
718 /* We must promise at least 20 bytes (one hash) after the
719 * offset is available from this window, otherwise the offset
720 * is not actually in this window and a different window (which
721 * has that one hash excess) must be used. This is to support
722 * the object header and delta base parsing routines below.
724 off_t win_off = win->offset;
725 return win_off <= offset
726 && (offset + 20) <= (win_off + win->len);
729 unsigned char* use_pack(struct packed_git *p,
730 struct pack_window **w_cursor,
734 struct pack_window *win = *w_cursor;
736 if (p->pack_fd == -1 && open_packed_git(p))
737 die("packfile %s cannot be accessed", p->pack_name);
739 /* Since packfiles end in a hash of their content and its
740 * pointless to ask for an offset into the middle of that
741 * hash, and the in_window function above wouldn't match
742 * don't allow an offset too close to the end of the file.
744 if (offset > (p->pack_size - 20))
745 die("offset beyond end of packfile (truncated pack?)");
747 if (!win || !in_window(win, offset)) {
750 for (win = p->windows; win; win = win->next) {
751 if (in_window(win, offset))
755 size_t window_align = packed_git_window_size / 2;
757 win = xcalloc(1, sizeof(*win));
758 win->offset = (offset / window_align) * window_align;
759 len = p->pack_size - win->offset;
760 if (len > packed_git_window_size)
761 len = packed_git_window_size;
762 win->len = (size_t)len;
763 pack_mapped += win->len;
764 while (packed_git_limit < pack_mapped
765 && unuse_one_window(p, p->pack_fd))
767 win->base = xmmap(NULL, win->len,
768 PROT_READ, MAP_PRIVATE,
769 p->pack_fd, win->offset);
770 if (win->base == MAP_FAILED)
771 die("packfile %s cannot be mapped: %s",
776 if (pack_mapped > peak_pack_mapped)
777 peak_pack_mapped = pack_mapped;
778 if (pack_open_windows > peak_pack_open_windows)
779 peak_pack_open_windows = pack_open_windows;
780 win->next = p->windows;
784 if (win != *w_cursor) {
785 win->last_used = pack_used_ctr++;
789 offset -= win->offset;
791 *left = win->len - xsize_t(offset);
792 return win->base + offset;
795 struct packed_git *add_packed_git(const char *path, int path_len, int local)
798 struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
801 * Make sure a corresponding .pack file exists and that
802 * the index looks sane.
804 path_len -= strlen(".idx");
807 memcpy(p->pack_name, path, path_len);
808 strcpy(p->pack_name + path_len, ".pack");
809 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
814 /* ok, it looks sane as far as we can check without
815 * actually mapping the pack file.
817 p->index_version = 0;
818 p->index_data = NULL;
821 p->pack_size = st.st_size;
825 p->pack_local = local;
826 p->mtime = st.st_mtime;
827 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
832 struct packed_git *parse_pack_index(unsigned char *sha1)
834 const char *idx_path = sha1_pack_index_name(sha1);
835 const char *path = sha1_pack_name(sha1);
836 struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
838 if (check_packed_git_idx(idx_path, p)) {
843 strcpy(p->pack_name, path);
848 hashcpy(p->sha1, sha1);
852 void install_packed_git(struct packed_git *pack)
854 pack->next = packed_git;
858 static void prepare_packed_git_one(char *objdir, int local)
860 /* Ensure that this buffer is large enough so that we can
861 append "/pack/" without clobbering the stack even if
862 strlen(objdir) were PATH_MAX. */
863 char path[PATH_MAX + 1 + 4 + 1 + 1];
868 sprintf(path, "%s/pack", objdir);
873 error("unable to open object pack directory: %s: %s",
874 path, strerror(errno));
878 while ((de = readdir(dir)) != NULL) {
879 int namelen = strlen(de->d_name);
880 struct packed_git *p;
882 if (!has_extension(de->d_name, ".idx"))
885 if (len + namelen + 1 > sizeof(path))
888 /* Don't reopen a pack we already have. */
889 strcpy(path + len, de->d_name);
890 for (p = packed_git; p; p = p->next) {
891 if (!memcmp(path, p->pack_name, len + namelen - 4))
896 /* See if it really is a valid .idx file with corresponding
897 * .pack file that we can map.
899 p = add_packed_git(path, len + namelen, local);
902 install_packed_git(p);
907 static int sort_pack(const void *a_, const void *b_)
909 struct packed_git *a = *((struct packed_git **)a_);
910 struct packed_git *b = *((struct packed_git **)b_);
914 * Local packs tend to contain objects specific to our
915 * variant of the project than remote ones. In addition,
916 * remote ones could be on a network mounted filesystem.
917 * Favor local ones for these reasons.
919 st = a->pack_local - b->pack_local;
924 * Younger packs tend to contain more recent objects,
925 * and more recent objects tend to get accessed more
928 if (a->mtime < b->mtime)
930 else if (a->mtime == b->mtime)
935 static void rearrange_packed_git(void)
937 struct packed_git **ary, *p;
940 for (n = 0, p = packed_git; p; p = p->next)
945 /* prepare an array of packed_git for easier sorting */
946 ary = xcalloc(n, sizeof(struct packed_git *));
947 for (n = 0, p = packed_git; p; p = p->next)
950 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
952 /* link them back again */
953 for (i = 0; i < n - 1; i++)
954 ary[i]->next = ary[i + 1];
955 ary[n - 1]->next = NULL;
961 static int prepare_packed_git_run_once = 0;
962 void prepare_packed_git(void)
964 struct alternate_object_database *alt;
966 if (prepare_packed_git_run_once)
968 prepare_packed_git_one(get_object_directory(), 1);
970 for (alt = alt_odb_list; alt; alt = alt->next) {
972 prepare_packed_git_one(alt->base, 0);
975 rearrange_packed_git();
976 prepare_packed_git_run_once = 1;
979 void reprepare_packed_git(void)
981 prepare_packed_git_run_once = 0;
982 prepare_packed_git();
985 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
987 unsigned char real_sha1[20];
988 hash_sha1_file(map, size, type, real_sha1);
989 return hashcmp(sha1, real_sha1) ? -1 : 0;
992 static int git_open_noatime(const char *name)
994 static int sha1_file_open_flag = O_NOATIME;
995 int fd = open(name, O_RDONLY | sha1_file_open_flag);
997 /* Might the failure be due to O_NOATIME? */
998 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
999 fd = open(name, O_RDONLY);
1001 sha1_file_open_flag = 0;
1006 static int open_sha1_file(const unsigned char *sha1)
1009 char *name = sha1_file_name(sha1);
1010 struct alternate_object_database *alt;
1012 fd = git_open_noatime(name);
1018 for (alt = alt_odb_list; alt; alt = alt->next) {
1020 fill_sha1_path(name, sha1);
1021 fd = git_open_noatime(alt->base);
1028 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1033 fd = open_sha1_file(sha1);
1038 if (!fstat(fd, &st)) {
1039 *size = xsize_t(st.st_size);
1040 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1047 static int legacy_loose_object(unsigned char *map)
1052 * Is it a zlib-compressed buffer? If so, the first byte
1053 * must be 0x78 (15-bit window size, deflated), and the
1054 * first 16-bit word is evenly divisible by 31
1056 word = (map[0] << 8) + map[1];
1057 if (map[0] == 0x78 && !(word % 31))
1063 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
1068 unsigned long used = 0;
1071 *type = (c >> 4) & 7;
1077 if (sizeof(long) * 8 <= shift)
1080 size += (c & 0x7f) << shift;
1087 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1089 unsigned long size, used;
1090 static const char valid_loose_object_type[8] = {
1092 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1093 0, /* "delta" and others are invalid in a loose object */
1095 enum object_type type;
1097 /* Get the data stream */
1098 memset(stream, 0, sizeof(*stream));
1099 stream->next_in = map;
1100 stream->avail_in = mapsize;
1101 stream->next_out = buffer;
1102 stream->avail_out = bufsiz;
1104 if (legacy_loose_object(map)) {
1105 inflateInit(stream);
1106 return inflate(stream, 0);
1111 * There used to be a second loose object header format which
1112 * was meant to mimic the in-pack format, allowing for direct
1113 * copy of the object data. This format turned up not to be
1114 * really worth it and we don't write it any longer. But we
1115 * can still read it.
1117 used = unpack_object_header_gently(map, mapsize, &type, &size);
1118 if (!used || !valid_loose_object_type[type])
1123 /* Set up the stream for the rest.. */
1124 stream->next_in = map;
1125 stream->avail_in = mapsize;
1126 inflateInit(stream);
1128 /* And generate the fake traditional header */
1129 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1130 typename(type), size);
1134 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1136 int bytes = strlen(buffer) + 1;
1137 unsigned char *buf = xmalloc(1+size);
1141 n = stream->total_out - bytes;
1144 memcpy(buf, (char *) buffer + bytes, n);
1146 if (bytes <= size) {
1148 * The above condition must be (bytes <= size), not
1149 * (bytes < size). In other words, even though we
1150 * expect no more output and set avail_out to zer0,
1151 * the input zlib stream may have bytes that express
1152 * "this concludes the stream", and we *do* want to
1155 * Otherwise we would not be able to test that we
1156 * consumed all the input to reach the expected size;
1157 * we also want to check that zlib tells us that all
1158 * went well with status == Z_STREAM_END at the end.
1160 stream->next_out = buf + bytes;
1161 stream->avail_out = size - bytes;
1162 while (status == Z_OK)
1163 status = inflate(stream, Z_FINISH);
1166 if (status == Z_STREAM_END && !stream->avail_in) {
1172 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1173 else if (stream->avail_in)
1174 error("garbage at end of loose object '%s'",
1181 * We used to just use "sscanf()", but that's actually way
1182 * too permissive for what we want to check. So do an anal
1183 * object header parse by hand.
1185 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1192 * The type can be at most ten bytes (including the
1193 * terminating '\0' that we add), and is followed by
1202 if (i >= sizeof(type))
1208 * The length must follow immediately, and be in canonical
1209 * decimal format (ie "010" is not valid).
1211 size = *hdr++ - '0';
1216 unsigned long c = *hdr - '0';
1220 size = size * 10 + c;
1226 * The length must be followed by a zero byte
1228 return *hdr ? -1 : type_from_string(type);
1231 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1237 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1238 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1241 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1244 unsigned long get_size_from_delta(struct packed_git *p,
1245 struct pack_window **w_curs,
1248 const unsigned char *data;
1249 unsigned char delta_head[20], *in;
1253 memset(&stream, 0, sizeof(stream));
1254 stream.next_out = delta_head;
1255 stream.avail_out = sizeof(delta_head);
1257 inflateInit(&stream);
1259 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1260 stream.next_in = in;
1261 st = inflate(&stream, Z_FINISH);
1262 curpos += stream.next_in - in;
1263 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1264 stream.total_out < sizeof(delta_head));
1265 inflateEnd(&stream);
1266 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1267 die("delta data unpack-initial failed");
1269 /* Examine the initial part of the delta to figure out
1274 /* ignore base size */
1275 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1277 /* Read the result size */
1278 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1281 static off_t get_delta_base(struct packed_git *p,
1282 struct pack_window **w_curs,
1284 enum object_type type,
1285 off_t delta_obj_offset)
1287 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1290 /* use_pack() assured us we have [base_info, base_info + 20)
1291 * as a range that we can look at without walking off the
1292 * end of the mapped window. Its actually the hash size
1293 * that is assured. An OFS_DELTA longer than the hash size
1294 * is stupid, as then a REF_DELTA would be smaller to store.
1296 if (type == OBJ_OFS_DELTA) {
1298 unsigned char c = base_info[used++];
1299 base_offset = c & 127;
1302 if (!base_offset || MSB(base_offset, 7))
1303 die("offset value overflow for delta base object");
1304 c = base_info[used++];
1305 base_offset = (base_offset << 7) + (c & 127);
1307 base_offset = delta_obj_offset - base_offset;
1308 if (base_offset >= delta_obj_offset)
1309 die("delta base offset out of bound");
1311 } else if (type == OBJ_REF_DELTA) {
1312 /* The base entry _must_ be in the same pack */
1313 base_offset = find_pack_entry_one(base_info, p);
1315 die("failed to find delta-pack base object %s",
1316 sha1_to_hex(base_info));
1319 die("I am totally screwed");
1323 /* forward declaration for a mutually recursive function */
1324 static int packed_object_info(struct packed_git *p, off_t offset,
1325 unsigned long *sizep);
1327 static int packed_delta_info(struct packed_git *p,
1328 struct pack_window **w_curs,
1330 enum object_type type,
1332 unsigned long *sizep)
1336 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1337 type = packed_object_info(p, base_offset, NULL);
1339 /* We choose to only get the type of the base object and
1340 * ignore potentially corrupt pack file that expects the delta
1341 * based on a base with a wrong size. This saves tons of
1345 *sizep = get_size_from_delta(p, w_curs, curpos);
1350 static int unpack_object_header(struct packed_git *p,
1351 struct pack_window **w_curs,
1353 unsigned long *sizep)
1355 unsigned char *base;
1358 enum object_type type;
1360 /* use_pack() assures us we have [base, base + 20) available
1361 * as a range that we can look at at. (Its actually the hash
1362 * size that is assured.) With our object header encoding
1363 * the maximum deflated object size is 2^137, which is just
1364 * insane, so we know won't exceed what we have been given.
1366 base = use_pack(p, w_curs, *curpos, &left);
1367 used = unpack_object_header_gently(base, left, &type, sizep);
1369 die("object offset outside of pack file");
1375 const char *packed_object_info_detail(struct packed_git *p,
1377 unsigned long *size,
1378 unsigned long *store_size,
1379 unsigned int *delta_chain_length,
1380 unsigned char *base_sha1)
1382 struct pack_window *w_curs = NULL;
1384 unsigned long dummy;
1385 unsigned char *next_sha1;
1386 enum object_type type;
1387 struct revindex_entry *revidx;
1389 *delta_chain_length = 0;
1390 curpos = obj_offset;
1391 type = unpack_object_header(p, &w_curs, &curpos, size);
1393 revidx = find_pack_revindex(p, obj_offset);
1394 *store_size = revidx[1].offset - obj_offset;
1399 die("pack %s contains unknown object type %d",
1400 p->pack_name, type);
1405 unuse_pack(&w_curs);
1406 return typename(type);
1408 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1409 if (*delta_chain_length == 0) {
1410 revidx = find_pack_revindex(p, obj_offset);
1411 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
1415 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1416 if (*delta_chain_length == 0)
1417 hashcpy(base_sha1, next_sha1);
1418 obj_offset = find_pack_entry_one(next_sha1, p);
1421 (*delta_chain_length)++;
1422 curpos = obj_offset;
1423 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1427 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1428 unsigned long *sizep)
1430 struct pack_window *w_curs = NULL;
1432 off_t curpos = obj_offset;
1433 enum object_type type;
1435 type = unpack_object_header(p, &w_curs, &curpos, &size);
1440 type = packed_delta_info(p, &w_curs, curpos,
1441 type, obj_offset, sizep);
1451 die("pack %s contains unknown object type %d",
1452 p->pack_name, type);
1454 unuse_pack(&w_curs);
1458 static void *unpack_compressed_entry(struct packed_git *p,
1459 struct pack_window **w_curs,
1465 unsigned char *buffer, *in;
1467 buffer = xmalloc(size + 1);
1469 memset(&stream, 0, sizeof(stream));
1470 stream.next_out = buffer;
1471 stream.avail_out = size;
1473 inflateInit(&stream);
1475 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1476 stream.next_in = in;
1477 st = inflate(&stream, Z_FINISH);
1478 curpos += stream.next_in - in;
1479 } while (st == Z_OK || st == Z_BUF_ERROR);
1480 inflateEnd(&stream);
1481 if ((st != Z_STREAM_END) || stream.total_out != size) {
1489 #define MAX_DELTA_CACHE (256)
1491 static size_t delta_base_cached;
1493 static struct delta_base_cache_lru_list {
1494 struct delta_base_cache_lru_list *prev;
1495 struct delta_base_cache_lru_list *next;
1496 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1498 static struct delta_base_cache_entry {
1499 struct delta_base_cache_lru_list lru;
1501 struct packed_git *p;
1504 enum object_type type;
1505 } delta_base_cache[MAX_DELTA_CACHE];
1507 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1511 hash = (unsigned long)p + (unsigned long)base_offset;
1512 hash += (hash >> 8) + (hash >> 16);
1513 return hash % MAX_DELTA_CACHE;
1516 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1517 unsigned long *base_size, enum object_type *type, int keep_cache)
1520 unsigned long hash = pack_entry_hash(p, base_offset);
1521 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1524 if (ret && ent->p == p && ent->base_offset == base_offset)
1525 goto found_cache_entry;
1526 return unpack_entry(p, base_offset, type, base_size);
1531 ent->lru.next->prev = ent->lru.prev;
1532 ent->lru.prev->next = ent->lru.next;
1533 delta_base_cached -= ent->size;
1535 ret = xmemdupz(ent->data, ent->size);
1538 *base_size = ent->size;
1542 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1547 ent->lru.next->prev = ent->lru.prev;
1548 ent->lru.prev->next = ent->lru.next;
1549 delta_base_cached -= ent->size;
1553 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1554 void *base, unsigned long base_size, enum object_type type)
1556 unsigned long hash = pack_entry_hash(p, base_offset);
1557 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1558 struct delta_base_cache_lru_list *lru;
1560 release_delta_base_cache(ent);
1561 delta_base_cached += base_size;
1563 for (lru = delta_base_cache_lru.next;
1564 delta_base_cached > delta_base_cache_limit
1565 && lru != &delta_base_cache_lru;
1567 struct delta_base_cache_entry *f = (void *)lru;
1568 if (f->type == OBJ_BLOB)
1569 release_delta_base_cache(f);
1571 for (lru = delta_base_cache_lru.next;
1572 delta_base_cached > delta_base_cache_limit
1573 && lru != &delta_base_cache_lru;
1575 struct delta_base_cache_entry *f = (void *)lru;
1576 release_delta_base_cache(f);
1580 ent->base_offset = base_offset;
1583 ent->size = base_size;
1584 ent->lru.next = &delta_base_cache_lru;
1585 ent->lru.prev = delta_base_cache_lru.prev;
1586 delta_base_cache_lru.prev->next = &ent->lru;
1587 delta_base_cache_lru.prev = &ent->lru;
1590 static void *unpack_delta_entry(struct packed_git *p,
1591 struct pack_window **w_curs,
1593 unsigned long delta_size,
1595 enum object_type *type,
1596 unsigned long *sizep)
1598 void *delta_data, *result, *base;
1599 unsigned long base_size;
1602 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1603 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1605 die("failed to read delta base object"
1606 " at %"PRIuMAX" from %s",
1607 (uintmax_t)base_offset, p->pack_name);
1609 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1611 die("failed to unpack compressed delta"
1612 " at %"PRIuMAX" from %s",
1613 (uintmax_t)curpos, p->pack_name);
1614 result = patch_delta(base, base_size,
1615 delta_data, delta_size,
1618 die("failed to apply delta");
1620 add_delta_base_cache(p, base_offset, base, base_size, *type);
1624 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1625 enum object_type *type, unsigned long *sizep)
1627 struct pack_window *w_curs = NULL;
1628 off_t curpos = obj_offset;
1631 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1635 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1636 obj_offset, type, sizep);
1642 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1645 die("unknown object type %i in %s", *type, p->pack_name);
1647 unuse_pack(&w_curs);
1651 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1654 const unsigned char *index = p->index_data;
1656 if (open_pack_index(p))
1658 index = p->index_data;
1660 if (n >= p->num_objects)
1663 if (p->index_version == 1) {
1664 return index + 24 * n + 4;
1667 return index + 20 * n;
1671 static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1673 const unsigned char *index = p->index_data;
1675 if (p->index_version == 1) {
1676 return ntohl(*((uint32_t *)(index + 24 * n)));
1679 index += 8 + p->num_objects * (20 + 4);
1680 off = ntohl(*((uint32_t *)(index + 4 * n)));
1681 if (!(off & 0x80000000))
1683 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1684 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1685 ntohl(*((uint32_t *)(index + 4)));
1689 off_t find_pack_entry_one(const unsigned char *sha1,
1690 struct packed_git *p)
1692 const uint32_t *level1_ofs = p->index_data;
1693 const unsigned char *index = p->index_data;
1694 unsigned hi, lo, stride;
1695 static int use_lookup = -1;
1696 static int debug_lookup = -1;
1698 if (debug_lookup < 0)
1699 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
1702 if (open_pack_index(p))
1704 level1_ofs = p->index_data;
1705 index = p->index_data;
1707 if (p->index_version > 1) {
1712 hi = ntohl(level1_ofs[*sha1]);
1713 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1714 if (p->index_version > 1) {
1722 printf("%02x%02x%02x... lo %u hi %u nr %u\n",
1723 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1726 use_lookup = !!getenv("GIT_USE_LOOKUP");
1728 int pos = sha1_entry_pos(index, stride, 0,
1729 lo, hi, p->num_objects, sha1);
1732 return nth_packed_object_offset(p, pos);
1736 unsigned mi = (lo + hi) / 2;
1737 int cmp = hashcmp(index + mi * stride, sha1);
1740 printf("lo %u hi %u rg %u mi %u\n",
1741 lo, hi, hi - lo, mi);
1743 return nth_packed_object_offset(p, mi);
1752 int matches_pack_name(struct packed_git *p, const char *name)
1754 const char *last_c, *c;
1756 if (!strcmp(p->pack_name, name))
1759 for (c = p->pack_name, last_c = c; *c;)
1764 if (!strcmp(last_c, name))
1770 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1772 static struct packed_git *last_found = (void *)1;
1773 struct packed_git *p;
1776 prepare_packed_git();
1779 p = (last_found == (void *)1) ? packed_git : last_found;
1782 if (ignore_packed) {
1784 for (ig = ignore_packed; *ig; ig++)
1785 if (matches_pack_name(p, *ig))
1791 offset = find_pack_entry_one(sha1, p);
1794 * We are about to tell the caller where they can
1795 * locate the requested object. We better make
1796 * sure the packfile is still here and can be
1797 * accessed before supplying that answer, as
1798 * it may have been deleted since the index
1801 if (p->pack_fd == -1 && open_packed_git(p)) {
1802 error("packfile %s cannot be accessed", p->pack_name);
1807 hashcpy(e->sha1, sha1);
1813 if (p == last_found)
1817 if (p == last_found)
1823 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1824 struct packed_git *packs)
1826 struct packed_git *p;
1828 for (p = packs; p; p = p->next) {
1829 if (find_pack_entry_one(sha1, p))
1836 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1839 unsigned long mapsize, size;
1844 map = map_sha1_file(sha1, &mapsize);
1846 return error("unable to find %s", sha1_to_hex(sha1));
1847 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1848 status = error("unable to unpack %s header",
1850 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1851 status = error("unable to parse %s header", sha1_to_hex(sha1));
1854 inflateEnd(&stream);
1855 munmap(map, mapsize);
1859 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1861 struct pack_entry e;
1863 if (!find_pack_entry(sha1, &e, NULL)) {
1864 reprepare_packed_git();
1865 if (!find_pack_entry(sha1, &e, NULL))
1866 return sha1_loose_object_info(sha1, sizep);
1868 return packed_object_info(e.p, e.offset, sizep);
1871 static void *read_packed_sha1(const unsigned char *sha1,
1872 enum object_type *type, unsigned long *size)
1874 struct pack_entry e;
1876 if (!find_pack_entry(sha1, &e, NULL))
1879 return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1883 * This is meant to hold a *small* number of objects that you would
1884 * want read_sha1_file() to be able to return, but yet you do not want
1885 * to write them into the object store (e.g. a browse-only
1888 static struct cached_object {
1889 unsigned char sha1[20];
1890 enum object_type type;
1894 static int cached_object_nr, cached_object_alloc;
1896 static struct cached_object empty_tree = {
1897 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
1898 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
1899 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
1905 static struct cached_object *find_cached_object(const unsigned char *sha1)
1908 struct cached_object *co = cached_objects;
1910 for (i = 0; i < cached_object_nr; i++, co++) {
1911 if (!hashcmp(co->sha1, sha1))
1914 if (!hashcmp(sha1, empty_tree.sha1))
1919 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1920 unsigned char *sha1)
1922 struct cached_object *co;
1924 hash_sha1_file(buf, len, typename(type), sha1);
1925 if (has_sha1_file(sha1) || find_cached_object(sha1))
1927 if (cached_object_alloc <= cached_object_nr) {
1928 cached_object_alloc = alloc_nr(cached_object_alloc);
1929 cached_objects = xrealloc(cached_objects,
1930 sizeof(*cached_objects) *
1931 cached_object_alloc);
1933 co = &cached_objects[cached_object_nr++];
1936 co->buf = xmalloc(len);
1937 memcpy(co->buf, buf, len);
1938 hashcpy(co->sha1, sha1);
1942 void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
1943 unsigned long *size)
1945 unsigned long mapsize;
1947 struct cached_object *co;
1949 co = find_cached_object(sha1);
1953 return xmemdupz(co->buf, co->size);
1956 buf = read_packed_sha1(sha1, type, size);
1959 map = map_sha1_file(sha1, &mapsize);
1961 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
1962 munmap(map, mapsize);
1965 reprepare_packed_git();
1966 return read_packed_sha1(sha1, type, size);
1969 void *read_object_with_reference(const unsigned char *sha1,
1970 const char *required_type_name,
1971 unsigned long *size,
1972 unsigned char *actual_sha1_return)
1974 enum object_type type, required_type;
1976 unsigned long isize;
1977 unsigned char actual_sha1[20];
1979 required_type = type_from_string(required_type_name);
1980 hashcpy(actual_sha1, sha1);
1982 int ref_length = -1;
1983 const char *ref_type = NULL;
1985 buffer = read_sha1_file(actual_sha1, &type, &isize);
1988 if (type == required_type) {
1990 if (actual_sha1_return)
1991 hashcpy(actual_sha1_return, actual_sha1);
1994 /* Handle references */
1995 else if (type == OBJ_COMMIT)
1997 else if (type == OBJ_TAG)
1998 ref_type = "object ";
2003 ref_length = strlen(ref_type);
2005 if (ref_length + 40 > isize ||
2006 memcmp(buffer, ref_type, ref_length) ||
2007 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2012 /* Now we have the ID of the referred-to object in
2013 * actual_sha1. Check again. */
2017 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2018 const char *type, unsigned char *sha1,
2019 char *hdr, int *hdrlen)
2023 /* Generate the header */
2024 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2028 SHA1_Update(&c, hdr, *hdrlen);
2029 SHA1_Update(&c, buf, len);
2030 SHA1_Final(sha1, &c);
2034 * Move the just written object into its final resting place
2036 int move_temp_to_file(const char *tmpfile, const char *filename)
2038 int ret = link(tmpfile, filename);
2041 * Coda hack - coda doesn't like cross-directory links,
2042 * so we fall back to a rename, which will mean that it
2043 * won't be able to check collisions, but that's not a
2046 * The same holds for FAT formatted media.
2048 * When this succeeds, we just return 0. We have nothing
2051 if (ret && ret != EEXIST) {
2052 if (!rename(tmpfile, filename))
2058 if (ret != EEXIST) {
2059 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
2061 /* FIXME!!! Collision check here ? */
2067 static int write_buffer(int fd, const void *buf, size_t len)
2069 if (write_in_full(fd, buf, len) < 0)
2070 return error("file write error (%s)", strerror(errno));
2074 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2075 unsigned char *sha1)
2079 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2083 /* Finalize a file on disk, and close it. */
2084 static void close_sha1_file(int fd)
2086 /* For safe-mode, we could fsync_or_die(fd, "sha1 file") here */
2089 die("unable to write sha1 file");
2092 /* Size of directory component, including the ending '/' */
2093 static inline int directory_size(const char *filename)
2095 const char *s = strrchr(filename, '/');
2098 return s - filename + 1;
2102 * This creates a temporary file in the same directory as the final
2105 * We want to avoid cross-directory filename renames, because those
2106 * can have problems on various filesystems (FAT, NFS, Coda).
2108 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2110 int fd, dirlen = directory_size(filename);
2112 if (dirlen + 20 > bufsiz) {
2113 errno = ENAMETOOLONG;
2116 memcpy(buffer, filename, dirlen);
2117 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2118 fd = mkstemp(buffer);
2119 if (fd < 0 && dirlen) {
2120 /* Make sure the directory exists */
2121 buffer[dirlen-1] = 0;
2122 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2126 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2127 fd = mkstemp(buffer);
2132 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2133 void *buf, unsigned long len, time_t mtime)
2136 unsigned char *compressed;
2139 static char tmpfile[PATH_MAX];
2141 filename = sha1_file_name(sha1);
2142 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2145 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2147 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2151 memset(&stream, 0, sizeof(stream));
2152 deflateInit(&stream, zlib_compression_level);
2153 size = 8 + deflateBound(&stream, len+hdrlen);
2154 compressed = xmalloc(size);
2157 stream.next_out = compressed;
2158 stream.avail_out = size;
2160 /* First header.. */
2161 stream.next_in = (unsigned char *)hdr;
2162 stream.avail_in = hdrlen;
2163 while (deflate(&stream, 0) == Z_OK)
2166 /* Then the data itself.. */
2167 stream.next_in = buf;
2168 stream.avail_in = len;
2169 ret = deflate(&stream, Z_FINISH);
2170 if (ret != Z_STREAM_END)
2171 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2173 ret = deflateEnd(&stream);
2175 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2177 size = stream.total_out;
2179 if (write_buffer(fd, compressed, size) < 0)
2180 die("unable to write sha1 file");
2181 close_sha1_file(fd);
2187 utb.modtime = mtime;
2188 if (utime(tmpfile, &utb) < 0)
2189 warning("failed utime() on %s: %s",
2190 tmpfile, strerror(errno));
2193 return move_temp_to_file(tmpfile, filename);
2196 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2198 unsigned char sha1[20];
2202 /* Normally if we have it in the pack then we do not bother writing
2203 * it out into .git/objects/??/?{38} file.
2205 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2207 hashcpy(returnsha1, sha1);
2208 if (has_sha1_file(sha1))
2210 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2213 int force_object_loose(const unsigned char *sha1, time_t mtime)
2217 enum object_type type;
2221 if (has_loose_object(sha1))
2223 buf = read_packed_sha1(sha1, &type, &len);
2225 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2226 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2227 return write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2230 int has_pack_index(const unsigned char *sha1)
2233 if (stat(sha1_pack_index_name(sha1), &st))
2238 int has_pack_file(const unsigned char *sha1)
2241 if (stat(sha1_pack_name(sha1), &st))
2246 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
2248 struct pack_entry e;
2249 return find_pack_entry(sha1, &e, ignore_packed);
2252 int has_sha1_file(const unsigned char *sha1)
2254 struct pack_entry e;
2256 if (find_pack_entry(sha1, &e, NULL))
2258 return has_loose_object(sha1);
2261 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2266 strbuf_init(&buf, 0);
2267 if (strbuf_read(&buf, fd, 4096) < 0) {
2268 strbuf_release(&buf);
2275 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
2277 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
2278 strbuf_release(&buf);
2283 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2284 enum object_type type, const char *path)
2286 size_t size = xsize_t(st->st_size);
2288 int ret, re_allocated = 0;
2291 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2298 * Convert blobs to git internal format
2300 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
2302 strbuf_init(&nbuf, 0);
2303 if (convert_to_git(path, buf, size, &nbuf,
2304 write_object ? safe_crlf : 0)) {
2306 buf = strbuf_detach(&nbuf, &size);
2312 ret = write_sha1_file(buf, size, typename(type), sha1);
2314 ret = hash_sha1_file(buf, size, typename(type), sha1);
2324 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2330 switch (st->st_mode & S_IFMT) {
2332 fd = open(path, O_RDONLY);
2334 return error("open(\"%s\"): %s", path,
2336 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2337 return error("%s: failed to insert into database",
2341 len = xsize_t(st->st_size);
2342 target = xmalloc(len + 1);
2343 if (readlink(path, target, len + 1) != st->st_size) {
2344 char *errstr = strerror(errno);
2346 return error("readlink(\"%s\"): %s", path,
2350 hash_sha1_file(target, len, blob_type, sha1);
2351 else if (write_sha1_file(target, len, blob_type, sha1))
2352 return error("%s: failed to insert into database",
2357 return resolve_gitlink_ref(path, "HEAD", sha1);
2359 return error("%s: unsupported file type", path);
2364 int read_pack_header(int fd, struct pack_header *header)
2366 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2367 /* "eof before pack header was fully read" */
2368 return PH_ERROR_EOF;
2370 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2371 /* "protocol error (pack signature mismatch detected)" */
2372 return PH_ERROR_PACK_SIGNATURE;
2373 if (!pack_version_ok(header->hdr_version))
2374 /* "protocol error (pack version unsupported)" */
2375 return PH_ERROR_PROTOCOL;