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[git.git] / sha1_file.c
blob7e38148fe52959e1cb8435132c65491dba6850b0
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "string-list.h"
11 #include "lockfile.h"
12 #include "delta.h"
13 #include "pack.h"
14 #include "blob.h"
15 #include "commit.h"
16 #include "run-command.h"
17 #include "tag.h"
18 #include "tree.h"
19 #include "tree-walk.h"
20 #include "refs.h"
21 #include "pack-revindex.h"
22 #include "sha1-lookup.h"
23 #include "bulk-checkin.h"
24 #include "streaming.h"
25 #include "dir.h"
27 #ifndef O_NOATIME
28 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
29 #define O_NOATIME 01000000
30 #else
31 #define O_NOATIME 0
32 #endif
33 #endif
35 #define SZ_FMT PRIuMAX
36 static inline uintmax_t sz_fmt(size_t s) { return s; }
38 const unsigned char null_sha1[20];
41 * This is meant to hold a *small* number of objects that you would
42 * want read_sha1_file() to be able to return, but yet you do not want
43 * to write them into the object store (e.g. a browse-only
44 * application).
46 static struct cached_object {
47 unsigned char sha1[20];
48 enum object_type type;
49 void *buf;
50 unsigned long size;
51 } *cached_objects;
52 static int cached_object_nr, cached_object_alloc;
54 static struct cached_object empty_tree = {
55 EMPTY_TREE_SHA1_BIN_LITERAL,
56 OBJ_TREE,
57 "",
62 * A pointer to the last packed_git in which an object was found.
63 * When an object is sought, we look in this packfile first, because
64 * objects that are looked up at similar times are often in the same
65 * packfile as one another.
67 static struct packed_git *last_found_pack;
69 static struct cached_object *find_cached_object(const unsigned char *sha1)
71 int i;
72 struct cached_object *co = cached_objects;
74 for (i = 0; i < cached_object_nr; i++, co++) {
75 if (!hashcmp(co->sha1, sha1))
76 return co;
78 if (!hashcmp(sha1, empty_tree.sha1))
79 return &empty_tree;
80 return NULL;
83 int mkdir_in_gitdir(const char *path)
85 if (mkdir(path, 0777)) {
86 int saved_errno = errno;
87 struct stat st;
88 struct strbuf sb = STRBUF_INIT;
90 if (errno != EEXIST)
91 return -1;
93 * Are we looking at a path in a symlinked worktree
94 * whose original repository does not yet have it?
95 * e.g. .git/rr-cache pointing at its original
96 * repository in which the user hasn't performed any
97 * conflict resolution yet?
99 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
100 strbuf_readlink(&sb, path, st.st_size) ||
101 !is_absolute_path(sb.buf) ||
102 mkdir(sb.buf, 0777)) {
103 strbuf_release(&sb);
104 errno = saved_errno;
105 return -1;
107 strbuf_release(&sb);
109 return adjust_shared_perm(path);
112 enum scld_error safe_create_leading_directories(char *path)
114 char *next_component = path + offset_1st_component(path);
115 enum scld_error ret = SCLD_OK;
117 while (ret == SCLD_OK && next_component) {
118 struct stat st;
119 char *slash = next_component, slash_character;
121 while (*slash && !is_dir_sep(*slash))
122 slash++;
124 if (!*slash)
125 break;
127 next_component = slash + 1;
128 while (is_dir_sep(*next_component))
129 next_component++;
130 if (!*next_component)
131 break;
133 slash_character = *slash;
134 *slash = '\0';
135 if (!stat(path, &st)) {
136 /* path exists */
137 if (!S_ISDIR(st.st_mode))
138 ret = SCLD_EXISTS;
139 } else if (mkdir(path, 0777)) {
140 if (errno == EEXIST &&
141 !stat(path, &st) && S_ISDIR(st.st_mode))
142 ; /* somebody created it since we checked */
143 else if (errno == ENOENT)
145 * Either mkdir() failed because
146 * somebody just pruned the containing
147 * directory, or stat() failed because
148 * the file that was in our way was
149 * just removed. Either way, inform
150 * the caller that it might be worth
151 * trying again:
153 ret = SCLD_VANISHED;
154 else
155 ret = SCLD_FAILED;
156 } else if (adjust_shared_perm(path)) {
157 ret = SCLD_PERMS;
159 *slash = slash_character;
161 return ret;
164 enum scld_error safe_create_leading_directories_const(const char *path)
166 /* path points to cache entries, so xstrdup before messing with it */
167 char *buf = xstrdup(path);
168 enum scld_error result = safe_create_leading_directories(buf);
169 free(buf);
170 return result;
173 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
175 int i;
176 for (i = 0; i < 20; i++) {
177 static char hex[] = "0123456789abcdef";
178 unsigned int val = sha1[i];
179 char *pos = pathbuf + i*2 + (i > 0);
180 *pos++ = hex[val >> 4];
181 *pos = hex[val & 0xf];
185 const char *sha1_file_name(const unsigned char *sha1)
187 static char buf[PATH_MAX];
188 const char *objdir;
189 int len;
191 objdir = get_object_directory();
192 len = strlen(objdir);
194 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
195 if (len + 43 > PATH_MAX)
196 die("insanely long object directory %s", objdir);
197 memcpy(buf, objdir, len);
198 buf[len] = '/';
199 buf[len+3] = '/';
200 buf[len+42] = '\0';
201 fill_sha1_path(buf + len + 1, sha1);
202 return buf;
206 * Return the name of the pack or index file with the specified sha1
207 * in its filename. *base and *name are scratch space that must be
208 * provided by the caller. which should be "pack" or "idx".
210 static char *sha1_get_pack_name(const unsigned char *sha1,
211 char **name, char **base, const char *which)
213 static const char hex[] = "0123456789abcdef";
214 char *buf;
215 int i;
217 if (!*base) {
218 const char *sha1_file_directory = get_object_directory();
219 int len = strlen(sha1_file_directory);
220 *base = xmalloc(len + 60);
221 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
222 sha1_file_directory, which);
223 *name = *base + len + 11;
226 buf = *name;
228 for (i = 0; i < 20; i++) {
229 unsigned int val = *sha1++;
230 *buf++ = hex[val >> 4];
231 *buf++ = hex[val & 0xf];
234 return *base;
237 char *sha1_pack_name(const unsigned char *sha1)
239 static char *name, *base;
241 return sha1_get_pack_name(sha1, &name, &base, "pack");
244 char *sha1_pack_index_name(const unsigned char *sha1)
246 static char *name, *base;
248 return sha1_get_pack_name(sha1, &name, &base, "idx");
251 struct alternate_object_database *alt_odb_list;
252 static struct alternate_object_database **alt_odb_tail;
255 * Prepare alternate object database registry.
257 * The variable alt_odb_list points at the list of struct
258 * alternate_object_database. The elements on this list come from
259 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
260 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
261 * whose contents is similar to that environment variable but can be
262 * LF separated. Its base points at a statically allocated buffer that
263 * contains "/the/directory/corresponding/to/.git/objects/...", while
264 * its name points just after the slash at the end of ".git/objects/"
265 * in the example above, and has enough space to hold 40-byte hex
266 * SHA1, an extra slash for the first level indirection, and the
267 * terminating NUL.
269 static int link_alt_odb_entry(const char *entry, const char *relative_base,
270 int depth, const char *normalized_objdir)
272 struct alternate_object_database *ent;
273 struct alternate_object_database *alt;
274 int pfxlen, entlen;
275 struct strbuf pathbuf = STRBUF_INIT;
277 if (!is_absolute_path(entry) && relative_base) {
278 strbuf_addstr(&pathbuf, real_path(relative_base));
279 strbuf_addch(&pathbuf, '/');
281 strbuf_addstr(&pathbuf, entry);
283 normalize_path_copy(pathbuf.buf, pathbuf.buf);
285 pfxlen = strlen(pathbuf.buf);
288 * The trailing slash after the directory name is given by
289 * this function at the end. Remove duplicates.
291 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
292 pfxlen -= 1;
294 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
295 ent = xmalloc(sizeof(*ent) + entlen);
296 memcpy(ent->base, pathbuf.buf, pfxlen);
297 strbuf_release(&pathbuf);
299 ent->name = ent->base + pfxlen + 1;
300 ent->base[pfxlen + 3] = '/';
301 ent->base[pfxlen] = ent->base[entlen-1] = 0;
303 /* Detect cases where alternate disappeared */
304 if (!is_directory(ent->base)) {
305 error("object directory %s does not exist; "
306 "check .git/objects/info/alternates.",
307 ent->base);
308 free(ent);
309 return -1;
312 /* Prevent the common mistake of listing the same
313 * thing twice, or object directory itself.
315 for (alt = alt_odb_list; alt; alt = alt->next) {
316 if (pfxlen == alt->name - alt->base - 1 &&
317 !memcmp(ent->base, alt->base, pfxlen)) {
318 free(ent);
319 return -1;
322 if (!strcmp_icase(ent->base, normalized_objdir)) {
323 free(ent);
324 return -1;
327 /* add the alternate entry */
328 *alt_odb_tail = ent;
329 alt_odb_tail = &(ent->next);
330 ent->next = NULL;
332 /* recursively add alternates */
333 read_info_alternates(ent->base, depth + 1);
335 ent->base[pfxlen] = '/';
337 return 0;
340 static void link_alt_odb_entries(const char *alt, int len, int sep,
341 const char *relative_base, int depth)
343 struct string_list entries = STRING_LIST_INIT_NODUP;
344 char *alt_copy;
345 int i;
346 struct strbuf objdirbuf = STRBUF_INIT;
348 if (depth > 5) {
349 error("%s: ignoring alternate object stores, nesting too deep.",
350 relative_base);
351 return;
354 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
355 normalize_path_copy(objdirbuf.buf, objdirbuf.buf);
357 alt_copy = xmemdupz(alt, len);
358 string_list_split_in_place(&entries, alt_copy, sep, -1);
359 for (i = 0; i < entries.nr; i++) {
360 const char *entry = entries.items[i].string;
361 if (entry[0] == '\0' || entry[0] == '#')
362 continue;
363 if (!is_absolute_path(entry) && depth) {
364 error("%s: ignoring relative alternate object store %s",
365 relative_base, entry);
366 } else {
367 link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf);
370 string_list_clear(&entries, 0);
371 free(alt_copy);
372 strbuf_release(&objdirbuf);
375 void read_info_alternates(const char * relative_base, int depth)
377 char *map;
378 size_t mapsz;
379 struct stat st;
380 const char alt_file_name[] = "info/alternates";
381 /* Given that relative_base is no longer than PATH_MAX,
382 ensure that "path" has enough space to append "/", the
383 file name, "info/alternates", and a trailing NUL. */
384 char path[PATH_MAX + 1 + sizeof alt_file_name];
385 int fd;
387 sprintf(path, "%s/%s", relative_base, alt_file_name);
388 fd = git_open_noatime(path);
389 if (fd < 0)
390 return;
391 if (fstat(fd, &st) || (st.st_size == 0)) {
392 close(fd);
393 return;
395 mapsz = xsize_t(st.st_size);
396 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
397 close(fd);
399 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
401 munmap(map, mapsz);
404 void add_to_alternates_file(const char *reference)
406 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
407 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
408 const char *alt = mkpath("%s\n", reference);
409 write_or_die(fd, alt, strlen(alt));
410 if (commit_lock_file(lock))
411 die("could not close alternates file");
412 if (alt_odb_tail)
413 link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
416 int foreach_alt_odb(alt_odb_fn fn, void *cb)
418 struct alternate_object_database *ent;
419 int r = 0;
421 prepare_alt_odb();
422 for (ent = alt_odb_list; ent; ent = ent->next) {
423 r = fn(ent, cb);
424 if (r)
425 break;
427 return r;
430 void prepare_alt_odb(void)
432 const char *alt;
434 if (alt_odb_tail)
435 return;
437 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
438 if (!alt) alt = "";
440 alt_odb_tail = &alt_odb_list;
441 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
443 read_info_alternates(get_object_directory(), 0);
446 static int freshen_file(const char *fn)
448 struct utimbuf t;
449 t.actime = t.modtime = time(NULL);
450 return !utime(fn, &t);
453 static int check_and_freshen_file(const char *fn, int freshen)
455 if (access(fn, F_OK))
456 return 0;
457 if (freshen && freshen_file(fn))
458 return 0;
459 return 1;
462 static int check_and_freshen_local(const unsigned char *sha1, int freshen)
464 return check_and_freshen_file(sha1_file_name(sha1), freshen);
467 static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
469 struct alternate_object_database *alt;
470 prepare_alt_odb();
471 for (alt = alt_odb_list; alt; alt = alt->next) {
472 fill_sha1_path(alt->name, sha1);
473 if (check_and_freshen_file(alt->base, freshen))
474 return 1;
476 return 0;
479 static int check_and_freshen(const unsigned char *sha1, int freshen)
481 return check_and_freshen_local(sha1, freshen) ||
482 check_and_freshen_nonlocal(sha1, freshen);
485 int has_loose_object_nonlocal(const unsigned char *sha1)
487 return check_and_freshen_nonlocal(sha1, 0);
490 static int has_loose_object(const unsigned char *sha1)
492 return check_and_freshen(sha1, 0);
495 static unsigned int pack_used_ctr;
496 static unsigned int pack_mmap_calls;
497 static unsigned int peak_pack_open_windows;
498 static unsigned int pack_open_windows;
499 static unsigned int pack_open_fds;
500 static unsigned int pack_max_fds;
501 static size_t peak_pack_mapped;
502 static size_t pack_mapped;
503 struct packed_git *packed_git;
505 void pack_report(void)
507 fprintf(stderr,
508 "pack_report: getpagesize() = %10" SZ_FMT "\n"
509 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
510 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
511 sz_fmt(getpagesize()),
512 sz_fmt(packed_git_window_size),
513 sz_fmt(packed_git_limit));
514 fprintf(stderr,
515 "pack_report: pack_used_ctr = %10u\n"
516 "pack_report: pack_mmap_calls = %10u\n"
517 "pack_report: pack_open_windows = %10u / %10u\n"
518 "pack_report: pack_mapped = "
519 "%10" SZ_FMT " / %10" SZ_FMT "\n",
520 pack_used_ctr,
521 pack_mmap_calls,
522 pack_open_windows, peak_pack_open_windows,
523 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
527 * Open and mmap the index file at path, perform a couple of
528 * consistency checks, then record its information to p. Return 0 on
529 * success.
531 static int check_packed_git_idx(const char *path, struct packed_git *p)
533 void *idx_map;
534 struct pack_idx_header *hdr;
535 size_t idx_size;
536 uint32_t version, nr, i, *index;
537 int fd = git_open_noatime(path);
538 struct stat st;
540 if (fd < 0)
541 return -1;
542 if (fstat(fd, &st)) {
543 close(fd);
544 return -1;
546 idx_size = xsize_t(st.st_size);
547 if (idx_size < 4 * 256 + 20 + 20) {
548 close(fd);
549 return error("index file %s is too small", path);
551 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
552 close(fd);
554 hdr = idx_map;
555 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
556 version = ntohl(hdr->idx_version);
557 if (version < 2 || version > 2) {
558 munmap(idx_map, idx_size);
559 return error("index file %s is version %"PRIu32
560 " and is not supported by this binary"
561 " (try upgrading GIT to a newer version)",
562 path, version);
564 } else
565 version = 1;
567 nr = 0;
568 index = idx_map;
569 if (version > 1)
570 index += 2; /* skip index header */
571 for (i = 0; i < 256; i++) {
572 uint32_t n = ntohl(index[i]);
573 if (n < nr) {
574 munmap(idx_map, idx_size);
575 return error("non-monotonic index %s", path);
577 nr = n;
580 if (version == 1) {
582 * Total size:
583 * - 256 index entries 4 bytes each
584 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
585 * - 20-byte SHA1 of the packfile
586 * - 20-byte SHA1 file checksum
588 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
589 munmap(idx_map, idx_size);
590 return error("wrong index v1 file size in %s", path);
592 } else if (version == 2) {
594 * Minimum size:
595 * - 8 bytes of header
596 * - 256 index entries 4 bytes each
597 * - 20-byte sha1 entry * nr
598 * - 4-byte crc entry * nr
599 * - 4-byte offset entry * nr
600 * - 20-byte SHA1 of the packfile
601 * - 20-byte SHA1 file checksum
602 * And after the 4-byte offset table might be a
603 * variable sized table containing 8-byte entries
604 * for offsets larger than 2^31.
606 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
607 unsigned long max_size = min_size;
608 if (nr)
609 max_size += (nr - 1)*8;
610 if (idx_size < min_size || idx_size > max_size) {
611 munmap(idx_map, idx_size);
612 return error("wrong index v2 file size in %s", path);
614 if (idx_size != min_size &&
616 * make sure we can deal with large pack offsets.
617 * 31-bit signed offset won't be enough, neither
618 * 32-bit unsigned one will be.
620 (sizeof(off_t) <= 4)) {
621 munmap(idx_map, idx_size);
622 return error("pack too large for current definition of off_t in %s", path);
626 p->index_version = version;
627 p->index_data = idx_map;
628 p->index_size = idx_size;
629 p->num_objects = nr;
630 return 0;
633 int open_pack_index(struct packed_git *p)
635 char *idx_name;
636 int ret;
638 if (p->index_data)
639 return 0;
641 idx_name = xstrdup(p->pack_name);
642 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
643 ret = check_packed_git_idx(idx_name, p);
644 free(idx_name);
645 return ret;
648 static void scan_windows(struct packed_git *p,
649 struct packed_git **lru_p,
650 struct pack_window **lru_w,
651 struct pack_window **lru_l)
653 struct pack_window *w, *w_l;
655 for (w_l = NULL, w = p->windows; w; w = w->next) {
656 if (!w->inuse_cnt) {
657 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
658 *lru_p = p;
659 *lru_w = w;
660 *lru_l = w_l;
663 w_l = w;
667 static int unuse_one_window(struct packed_git *current)
669 struct packed_git *p, *lru_p = NULL;
670 struct pack_window *lru_w = NULL, *lru_l = NULL;
672 if (current)
673 scan_windows(current, &lru_p, &lru_w, &lru_l);
674 for (p = packed_git; p; p = p->next)
675 scan_windows(p, &lru_p, &lru_w, &lru_l);
676 if (lru_p) {
677 munmap(lru_w->base, lru_w->len);
678 pack_mapped -= lru_w->len;
679 if (lru_l)
680 lru_l->next = lru_w->next;
681 else
682 lru_p->windows = lru_w->next;
683 free(lru_w);
684 pack_open_windows--;
685 return 1;
687 return 0;
690 void release_pack_memory(size_t need)
692 size_t cur = pack_mapped;
693 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
694 ; /* nothing */
697 static void mmap_limit_check(size_t length)
699 static size_t limit = 0;
700 if (!limit) {
701 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
702 if (!limit)
703 limit = SIZE_MAX;
705 if (length > limit)
706 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
707 (uintmax_t)length, (uintmax_t)limit);
710 void *xmmap(void *start, size_t length,
711 int prot, int flags, int fd, off_t offset)
713 void *ret;
715 mmap_limit_check(length);
716 ret = mmap(start, length, prot, flags, fd, offset);
717 if (ret == MAP_FAILED) {
718 if (!length)
719 return NULL;
720 release_pack_memory(length);
721 ret = mmap(start, length, prot, flags, fd, offset);
722 if (ret == MAP_FAILED)
723 die_errno("Out of memory? mmap failed");
725 return ret;
728 void close_pack_windows(struct packed_git *p)
730 while (p->windows) {
731 struct pack_window *w = p->windows;
733 if (w->inuse_cnt)
734 die("pack '%s' still has open windows to it",
735 p->pack_name);
736 munmap(w->base, w->len);
737 pack_mapped -= w->len;
738 pack_open_windows--;
739 p->windows = w->next;
740 free(w);
745 * The LRU pack is the one with the oldest MRU window, preferring packs
746 * with no used windows, or the oldest mtime if it has no windows allocated.
748 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
750 struct pack_window *w, *this_mru_w;
751 int has_windows_inuse = 0;
754 * Reject this pack if it has windows and the previously selected
755 * one does not. If this pack does not have windows, reject
756 * it if the pack file is newer than the previously selected one.
758 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
759 return;
761 for (w = this_mru_w = p->windows; w; w = w->next) {
763 * Reject this pack if any of its windows are in use,
764 * but the previously selected pack did not have any
765 * inuse windows. Otherwise, record that this pack
766 * has windows in use.
768 if (w->inuse_cnt) {
769 if (*accept_windows_inuse)
770 has_windows_inuse = 1;
771 else
772 return;
775 if (w->last_used > this_mru_w->last_used)
776 this_mru_w = w;
779 * Reject this pack if it has windows that have been
780 * used more recently than the previously selected pack.
781 * If the previously selected pack had windows inuse and
782 * we have not encountered a window in this pack that is
783 * inuse, skip this check since we prefer a pack with no
784 * inuse windows to one that has inuse windows.
786 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
787 this_mru_w->last_used > (*mru_w)->last_used)
788 return;
792 * Select this pack.
794 *mru_w = this_mru_w;
795 *lru_p = p;
796 *accept_windows_inuse = has_windows_inuse;
799 static int close_one_pack(void)
801 struct packed_git *p, *lru_p = NULL;
802 struct pack_window *mru_w = NULL;
803 int accept_windows_inuse = 1;
805 for (p = packed_git; p; p = p->next) {
806 if (p->pack_fd == -1)
807 continue;
808 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
811 if (lru_p) {
812 close(lru_p->pack_fd);
813 pack_open_fds--;
814 lru_p->pack_fd = -1;
815 return 1;
818 return 0;
821 void unuse_pack(struct pack_window **w_cursor)
823 struct pack_window *w = *w_cursor;
824 if (w) {
825 w->inuse_cnt--;
826 *w_cursor = NULL;
830 void close_pack_index(struct packed_git *p)
832 if (p->index_data) {
833 munmap((void *)p->index_data, p->index_size);
834 p->index_data = NULL;
839 * This is used by git-repack in case a newly created pack happens to
840 * contain the same set of objects as an existing one. In that case
841 * the resulting file might be different even if its name would be the
842 * same. It is best to close any reference to the old pack before it is
843 * replaced on disk. Of course no index pointers or windows for given pack
844 * must subsist at this point. If ever objects from this pack are requested
845 * again, the new version of the pack will be reinitialized through
846 * reprepare_packed_git().
848 void free_pack_by_name(const char *pack_name)
850 struct packed_git *p, **pp = &packed_git;
852 while (*pp) {
853 p = *pp;
854 if (strcmp(pack_name, p->pack_name) == 0) {
855 clear_delta_base_cache();
856 close_pack_windows(p);
857 if (p->pack_fd != -1) {
858 close(p->pack_fd);
859 pack_open_fds--;
861 close_pack_index(p);
862 free(p->bad_object_sha1);
863 *pp = p->next;
864 if (last_found_pack == p)
865 last_found_pack = NULL;
866 free(p);
867 return;
869 pp = &p->next;
873 static unsigned int get_max_fd_limit(void)
875 #ifdef RLIMIT_NOFILE
877 struct rlimit lim;
879 if (!getrlimit(RLIMIT_NOFILE, &lim))
880 return lim.rlim_cur;
882 #endif
884 #ifdef _SC_OPEN_MAX
886 long open_max = sysconf(_SC_OPEN_MAX);
887 if (0 < open_max)
888 return open_max;
890 * Otherwise, we got -1 for one of the two
891 * reasons:
893 * (1) sysconf() did not understand _SC_OPEN_MAX
894 * and signaled an error with -1; or
895 * (2) sysconf() said there is no limit.
897 * We _could_ clear errno before calling sysconf() to
898 * tell these two cases apart and return a huge number
899 * in the latter case to let the caller cap it to a
900 * value that is not so selfish, but letting the
901 * fallback OPEN_MAX codepath take care of these cases
902 * is a lot simpler.
905 #endif
907 #ifdef OPEN_MAX
908 return OPEN_MAX;
909 #else
910 return 1; /* see the caller ;-) */
911 #endif
915 * Do not call this directly as this leaks p->pack_fd on error return;
916 * call open_packed_git() instead.
918 static int open_packed_git_1(struct packed_git *p)
920 struct stat st;
921 struct pack_header hdr;
922 unsigned char sha1[20];
923 unsigned char *idx_sha1;
924 long fd_flag;
926 if (!p->index_data && open_pack_index(p))
927 return error("packfile %s index unavailable", p->pack_name);
929 if (!pack_max_fds) {
930 unsigned int max_fds = get_max_fd_limit();
932 /* Save 3 for stdin/stdout/stderr, 22 for work */
933 if (25 < max_fds)
934 pack_max_fds = max_fds - 25;
935 else
936 pack_max_fds = 1;
939 while (pack_max_fds <= pack_open_fds && close_one_pack())
940 ; /* nothing */
942 p->pack_fd = git_open_noatime(p->pack_name);
943 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
944 return -1;
945 pack_open_fds++;
947 /* If we created the struct before we had the pack we lack size. */
948 if (!p->pack_size) {
949 if (!S_ISREG(st.st_mode))
950 return error("packfile %s not a regular file", p->pack_name);
951 p->pack_size = st.st_size;
952 } else if (p->pack_size != st.st_size)
953 return error("packfile %s size changed", p->pack_name);
955 /* We leave these file descriptors open with sliding mmap;
956 * there is no point keeping them open across exec(), though.
958 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
959 if (fd_flag < 0)
960 return error("cannot determine file descriptor flags");
961 fd_flag |= FD_CLOEXEC;
962 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
963 return error("cannot set FD_CLOEXEC");
965 /* Verify we recognize this pack file format. */
966 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
967 return error("file %s is far too short to be a packfile", p->pack_name);
968 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
969 return error("file %s is not a GIT packfile", p->pack_name);
970 if (!pack_version_ok(hdr.hdr_version))
971 return error("packfile %s is version %"PRIu32" and not"
972 " supported (try upgrading GIT to a newer version)",
973 p->pack_name, ntohl(hdr.hdr_version));
975 /* Verify the pack matches its index. */
976 if (p->num_objects != ntohl(hdr.hdr_entries))
977 return error("packfile %s claims to have %"PRIu32" objects"
978 " while index indicates %"PRIu32" objects",
979 p->pack_name, ntohl(hdr.hdr_entries),
980 p->num_objects);
981 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
982 return error("end of packfile %s is unavailable", p->pack_name);
983 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
984 return error("packfile %s signature is unavailable", p->pack_name);
985 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
986 if (hashcmp(sha1, idx_sha1))
987 return error("packfile %s does not match index", p->pack_name);
988 return 0;
991 static int open_packed_git(struct packed_git *p)
993 if (!open_packed_git_1(p))
994 return 0;
995 if (p->pack_fd != -1) {
996 close(p->pack_fd);
997 pack_open_fds--;
998 p->pack_fd = -1;
1000 return -1;
1003 static int in_window(struct pack_window *win, off_t offset)
1005 /* We must promise at least 20 bytes (one hash) after the
1006 * offset is available from this window, otherwise the offset
1007 * is not actually in this window and a different window (which
1008 * has that one hash excess) must be used. This is to support
1009 * the object header and delta base parsing routines below.
1011 off_t win_off = win->offset;
1012 return win_off <= offset
1013 && (offset + 20) <= (win_off + win->len);
1016 unsigned char *use_pack(struct packed_git *p,
1017 struct pack_window **w_cursor,
1018 off_t offset,
1019 unsigned long *left)
1021 struct pack_window *win = *w_cursor;
1023 /* Since packfiles end in a hash of their content and it's
1024 * pointless to ask for an offset into the middle of that
1025 * hash, and the in_window function above wouldn't match
1026 * don't allow an offset too close to the end of the file.
1028 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1029 die("packfile %s cannot be accessed", p->pack_name);
1030 if (offset > (p->pack_size - 20))
1031 die("offset beyond end of packfile (truncated pack?)");
1033 if (!win || !in_window(win, offset)) {
1034 if (win)
1035 win->inuse_cnt--;
1036 for (win = p->windows; win; win = win->next) {
1037 if (in_window(win, offset))
1038 break;
1040 if (!win) {
1041 size_t window_align = packed_git_window_size / 2;
1042 off_t len;
1044 if (p->pack_fd == -1 && open_packed_git(p))
1045 die("packfile %s cannot be accessed", p->pack_name);
1047 win = xcalloc(1, sizeof(*win));
1048 win->offset = (offset / window_align) * window_align;
1049 len = p->pack_size - win->offset;
1050 if (len > packed_git_window_size)
1051 len = packed_git_window_size;
1052 win->len = (size_t)len;
1053 pack_mapped += win->len;
1054 while (packed_git_limit < pack_mapped
1055 && unuse_one_window(p))
1056 ; /* nothing */
1057 win->base = xmmap(NULL, win->len,
1058 PROT_READ, MAP_PRIVATE,
1059 p->pack_fd, win->offset);
1060 if (win->base == MAP_FAILED)
1061 die("packfile %s cannot be mapped: %s",
1062 p->pack_name,
1063 strerror(errno));
1064 if (!win->offset && win->len == p->pack_size
1065 && !p->do_not_close) {
1066 close(p->pack_fd);
1067 pack_open_fds--;
1068 p->pack_fd = -1;
1070 pack_mmap_calls++;
1071 pack_open_windows++;
1072 if (pack_mapped > peak_pack_mapped)
1073 peak_pack_mapped = pack_mapped;
1074 if (pack_open_windows > peak_pack_open_windows)
1075 peak_pack_open_windows = pack_open_windows;
1076 win->next = p->windows;
1077 p->windows = win;
1080 if (win != *w_cursor) {
1081 win->last_used = pack_used_ctr++;
1082 win->inuse_cnt++;
1083 *w_cursor = win;
1085 offset -= win->offset;
1086 if (left)
1087 *left = win->len - xsize_t(offset);
1088 return win->base + offset;
1091 static struct packed_git *alloc_packed_git(int extra)
1093 struct packed_git *p = xmalloc(sizeof(*p) + extra);
1094 memset(p, 0, sizeof(*p));
1095 p->pack_fd = -1;
1096 return p;
1099 static void try_to_free_pack_memory(size_t size)
1101 release_pack_memory(size);
1104 struct packed_git *add_packed_git(const char *path, int path_len, int local)
1106 static int have_set_try_to_free_routine;
1107 struct stat st;
1108 struct packed_git *p = alloc_packed_git(path_len + 2);
1110 if (!have_set_try_to_free_routine) {
1111 have_set_try_to_free_routine = 1;
1112 set_try_to_free_routine(try_to_free_pack_memory);
1116 * Make sure a corresponding .pack file exists and that
1117 * the index looks sane.
1119 path_len -= strlen(".idx");
1120 if (path_len < 1) {
1121 free(p);
1122 return NULL;
1124 memcpy(p->pack_name, path, path_len);
1126 strcpy(p->pack_name + path_len, ".keep");
1127 if (!access(p->pack_name, F_OK))
1128 p->pack_keep = 1;
1130 strcpy(p->pack_name + path_len, ".pack");
1131 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
1132 free(p);
1133 return NULL;
1136 /* ok, it looks sane as far as we can check without
1137 * actually mapping the pack file.
1139 p->pack_size = st.st_size;
1140 p->pack_local = local;
1141 p->mtime = st.st_mtime;
1142 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1143 hashclr(p->sha1);
1144 return p;
1147 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
1149 const char *path = sha1_pack_name(sha1);
1150 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
1152 strcpy(p->pack_name, path);
1153 hashcpy(p->sha1, sha1);
1154 if (check_packed_git_idx(idx_path, p)) {
1155 free(p);
1156 return NULL;
1159 return p;
1162 void install_packed_git(struct packed_git *pack)
1164 if (pack->pack_fd != -1)
1165 pack_open_fds++;
1167 pack->next = packed_git;
1168 packed_git = pack;
1171 void (*report_garbage)(const char *desc, const char *path);
1173 static void report_helper(const struct string_list *list,
1174 int seen_bits, int first, int last)
1176 const char *msg;
1177 switch (seen_bits) {
1178 case 0:
1179 msg = "no corresponding .idx or .pack";
1180 break;
1181 case 1:
1182 msg = "no corresponding .idx";
1183 break;
1184 case 2:
1185 msg = "no corresponding .pack";
1186 break;
1187 default:
1188 return;
1190 for (; first < last; first++)
1191 report_garbage(msg, list->items[first].string);
1194 static void report_pack_garbage(struct string_list *list)
1196 int i, baselen = -1, first = 0, seen_bits = 0;
1198 if (!report_garbage)
1199 return;
1201 string_list_sort(list);
1203 for (i = 0; i < list->nr; i++) {
1204 const char *path = list->items[i].string;
1205 if (baselen != -1 &&
1206 strncmp(path, list->items[first].string, baselen)) {
1207 report_helper(list, seen_bits, first, i);
1208 baselen = -1;
1209 seen_bits = 0;
1211 if (baselen == -1) {
1212 const char *dot = strrchr(path, '.');
1213 if (!dot) {
1214 report_garbage("garbage found", path);
1215 continue;
1217 baselen = dot - path + 1;
1218 first = i;
1220 if (!strcmp(path + baselen, "pack"))
1221 seen_bits |= 1;
1222 else if (!strcmp(path + baselen, "idx"))
1223 seen_bits |= 2;
1225 report_helper(list, seen_bits, first, list->nr);
1228 static void prepare_packed_git_one(char *objdir, int local)
1230 struct strbuf path = STRBUF_INIT;
1231 size_t dirnamelen;
1232 DIR *dir;
1233 struct dirent *de;
1234 struct string_list garbage = STRING_LIST_INIT_DUP;
1236 strbuf_addstr(&path, objdir);
1237 strbuf_addstr(&path, "/pack");
1238 dir = opendir(path.buf);
1239 if (!dir) {
1240 if (errno != ENOENT)
1241 error("unable to open object pack directory: %s: %s",
1242 path.buf, strerror(errno));
1243 strbuf_release(&path);
1244 return;
1246 strbuf_addch(&path, '/');
1247 dirnamelen = path.len;
1248 while ((de = readdir(dir)) != NULL) {
1249 struct packed_git *p;
1250 size_t base_len;
1252 if (is_dot_or_dotdot(de->d_name))
1253 continue;
1255 strbuf_setlen(&path, dirnamelen);
1256 strbuf_addstr(&path, de->d_name);
1258 base_len = path.len;
1259 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
1260 /* Don't reopen a pack we already have. */
1261 for (p = packed_git; p; p = p->next) {
1262 size_t len;
1263 if (strip_suffix(p->pack_name, ".pack", &len) &&
1264 len == base_len &&
1265 !memcmp(p->pack_name, path.buf, len))
1266 break;
1268 if (p == NULL &&
1270 * See if it really is a valid .idx file with
1271 * corresponding .pack file that we can map.
1273 (p = add_packed_git(path.buf, path.len, local)) != NULL)
1274 install_packed_git(p);
1277 if (!report_garbage)
1278 continue;
1280 if (ends_with(de->d_name, ".idx") ||
1281 ends_with(de->d_name, ".pack") ||
1282 ends_with(de->d_name, ".bitmap") ||
1283 ends_with(de->d_name, ".keep"))
1284 string_list_append(&garbage, path.buf);
1285 else
1286 report_garbage("garbage found", path.buf);
1288 closedir(dir);
1289 report_pack_garbage(&garbage);
1290 string_list_clear(&garbage, 0);
1291 strbuf_release(&path);
1294 static int sort_pack(const void *a_, const void *b_)
1296 struct packed_git *a = *((struct packed_git **)a_);
1297 struct packed_git *b = *((struct packed_git **)b_);
1298 int st;
1301 * Local packs tend to contain objects specific to our
1302 * variant of the project than remote ones. In addition,
1303 * remote ones could be on a network mounted filesystem.
1304 * Favor local ones for these reasons.
1306 st = a->pack_local - b->pack_local;
1307 if (st)
1308 return -st;
1311 * Younger packs tend to contain more recent objects,
1312 * and more recent objects tend to get accessed more
1313 * often.
1315 if (a->mtime < b->mtime)
1316 return 1;
1317 else if (a->mtime == b->mtime)
1318 return 0;
1319 return -1;
1322 static void rearrange_packed_git(void)
1324 struct packed_git **ary, *p;
1325 int i, n;
1327 for (n = 0, p = packed_git; p; p = p->next)
1328 n++;
1329 if (n < 2)
1330 return;
1332 /* prepare an array of packed_git for easier sorting */
1333 ary = xcalloc(n, sizeof(struct packed_git *));
1334 for (n = 0, p = packed_git; p; p = p->next)
1335 ary[n++] = p;
1337 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1339 /* link them back again */
1340 for (i = 0; i < n - 1; i++)
1341 ary[i]->next = ary[i + 1];
1342 ary[n - 1]->next = NULL;
1343 packed_git = ary[0];
1345 free(ary);
1348 static int prepare_packed_git_run_once = 0;
1349 void prepare_packed_git(void)
1351 struct alternate_object_database *alt;
1353 if (prepare_packed_git_run_once)
1354 return;
1355 prepare_packed_git_one(get_object_directory(), 1);
1356 prepare_alt_odb();
1357 for (alt = alt_odb_list; alt; alt = alt->next) {
1358 alt->name[-1] = 0;
1359 prepare_packed_git_one(alt->base, 0);
1360 alt->name[-1] = '/';
1362 rearrange_packed_git();
1363 prepare_packed_git_run_once = 1;
1366 void reprepare_packed_git(void)
1368 prepare_packed_git_run_once = 0;
1369 prepare_packed_git();
1372 static void mark_bad_packed_object(struct packed_git *p,
1373 const unsigned char *sha1)
1375 unsigned i;
1376 for (i = 0; i < p->num_bad_objects; i++)
1377 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1378 return;
1379 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1380 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1381 p->num_bad_objects++;
1384 static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1386 struct packed_git *p;
1387 unsigned i;
1389 for (p = packed_git; p; p = p->next)
1390 for (i = 0; i < p->num_bad_objects; i++)
1391 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1392 return p;
1393 return NULL;
1397 * With an in-core object data in "map", rehash it to make sure the
1398 * object name actually matches "sha1" to detect object corruption.
1399 * With "map" == NULL, try reading the object named with "sha1" using
1400 * the streaming interface and rehash it to do the same.
1402 int check_sha1_signature(const unsigned char *sha1, void *map,
1403 unsigned long size, const char *type)
1405 unsigned char real_sha1[20];
1406 enum object_type obj_type;
1407 struct git_istream *st;
1408 git_SHA_CTX c;
1409 char hdr[32];
1410 int hdrlen;
1412 if (map) {
1413 hash_sha1_file(map, size, type, real_sha1);
1414 return hashcmp(sha1, real_sha1) ? -1 : 0;
1417 st = open_istream(sha1, &obj_type, &size, NULL);
1418 if (!st)
1419 return -1;
1421 /* Generate the header */
1422 hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
1424 /* Sha1.. */
1425 git_SHA1_Init(&c);
1426 git_SHA1_Update(&c, hdr, hdrlen);
1427 for (;;) {
1428 char buf[1024 * 16];
1429 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1431 if (readlen < 0) {
1432 close_istream(st);
1433 return -1;
1435 if (!readlen)
1436 break;
1437 git_SHA1_Update(&c, buf, readlen);
1439 git_SHA1_Final(real_sha1, &c);
1440 close_istream(st);
1441 return hashcmp(sha1, real_sha1) ? -1 : 0;
1444 int git_open_noatime(const char *name)
1446 static int sha1_file_open_flag = O_NOATIME;
1448 for (;;) {
1449 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1450 if (fd >= 0)
1451 return fd;
1453 /* Might the failure be due to O_NOATIME? */
1454 if (errno != ENOENT && sha1_file_open_flag) {
1455 sha1_file_open_flag = 0;
1456 continue;
1459 return -1;
1463 static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1465 struct alternate_object_database *alt;
1467 if (!lstat(sha1_file_name(sha1), st))
1468 return 0;
1470 prepare_alt_odb();
1471 errno = ENOENT;
1472 for (alt = alt_odb_list; alt; alt = alt->next) {
1473 fill_sha1_path(alt->name, sha1);
1474 if (!lstat(alt->base, st))
1475 return 0;
1478 return -1;
1481 static int open_sha1_file(const unsigned char *sha1)
1483 int fd;
1484 struct alternate_object_database *alt;
1485 int most_interesting_errno;
1487 fd = git_open_noatime(sha1_file_name(sha1));
1488 if (fd >= 0)
1489 return fd;
1490 most_interesting_errno = errno;
1492 prepare_alt_odb();
1493 for (alt = alt_odb_list; alt; alt = alt->next) {
1494 fill_sha1_path(alt->name, sha1);
1495 fd = git_open_noatime(alt->base);
1496 if (fd >= 0)
1497 return fd;
1498 if (most_interesting_errno == ENOENT)
1499 most_interesting_errno = errno;
1501 errno = most_interesting_errno;
1502 return -1;
1505 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1507 void *map;
1508 int fd;
1510 fd = open_sha1_file(sha1);
1511 map = NULL;
1512 if (fd >= 0) {
1513 struct stat st;
1515 if (!fstat(fd, &st)) {
1516 *size = xsize_t(st.st_size);
1517 if (!*size) {
1518 /* mmap() is forbidden on empty files */
1519 error("object file %s is empty", sha1_file_name(sha1));
1520 return NULL;
1522 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1524 close(fd);
1526 return map;
1529 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1530 unsigned long len, enum object_type *type, unsigned long *sizep)
1532 unsigned shift;
1533 unsigned long size, c;
1534 unsigned long used = 0;
1536 c = buf[used++];
1537 *type = (c >> 4) & 7;
1538 size = c & 15;
1539 shift = 4;
1540 while (c & 0x80) {
1541 if (len <= used || bitsizeof(long) <= shift) {
1542 error("bad object header");
1543 size = used = 0;
1544 break;
1546 c = buf[used++];
1547 size += (c & 0x7f) << shift;
1548 shift += 7;
1550 *sizep = size;
1551 return used;
1554 int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1556 /* Get the data stream */
1557 memset(stream, 0, sizeof(*stream));
1558 stream->next_in = map;
1559 stream->avail_in = mapsize;
1560 stream->next_out = buffer;
1561 stream->avail_out = bufsiz;
1563 git_inflate_init(stream);
1564 return git_inflate(stream, 0);
1567 static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1568 unsigned long mapsize, void *buffer,
1569 unsigned long bufsiz, struct strbuf *header)
1571 int status;
1573 status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
1576 * Check if entire header is unpacked in the first iteration.
1578 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1579 return 0;
1582 * buffer[0..bufsiz] was not large enough. Copy the partial
1583 * result out to header, and then append the result of further
1584 * reading the stream.
1586 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1587 stream->next_out = buffer;
1588 stream->avail_out = bufsiz;
1590 do {
1591 status = git_inflate(stream, 0);
1592 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1593 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1594 return 0;
1595 stream->next_out = buffer;
1596 stream->avail_out = bufsiz;
1597 } while (status != Z_STREAM_END);
1598 return -1;
1601 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1603 int bytes = strlen(buffer) + 1;
1604 unsigned char *buf = xmallocz(size);
1605 unsigned long n;
1606 int status = Z_OK;
1608 n = stream->total_out - bytes;
1609 if (n > size)
1610 n = size;
1611 memcpy(buf, (char *) buffer + bytes, n);
1612 bytes = n;
1613 if (bytes <= size) {
1615 * The above condition must be (bytes <= size), not
1616 * (bytes < size). In other words, even though we
1617 * expect no more output and set avail_out to zero,
1618 * the input zlib stream may have bytes that express
1619 * "this concludes the stream", and we *do* want to
1620 * eat that input.
1622 * Otherwise we would not be able to test that we
1623 * consumed all the input to reach the expected size;
1624 * we also want to check that zlib tells us that all
1625 * went well with status == Z_STREAM_END at the end.
1627 stream->next_out = buf + bytes;
1628 stream->avail_out = size - bytes;
1629 while (status == Z_OK)
1630 status = git_inflate(stream, Z_FINISH);
1632 if (status == Z_STREAM_END && !stream->avail_in) {
1633 git_inflate_end(stream);
1634 return buf;
1637 if (status < 0)
1638 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1639 else if (stream->avail_in)
1640 error("garbage at end of loose object '%s'",
1641 sha1_to_hex(sha1));
1642 free(buf);
1643 return NULL;
1647 * We used to just use "sscanf()", but that's actually way
1648 * too permissive for what we want to check. So do an anal
1649 * object header parse by hand.
1651 static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1652 unsigned int flags)
1654 const char *type_buf = hdr;
1655 unsigned long size;
1656 int type, type_len = 0;
1659 * The type can be of any size but is followed by
1660 * a space.
1662 for (;;) {
1663 char c = *hdr++;
1664 if (c == ' ')
1665 break;
1666 type_len++;
1669 type = type_from_string_gently(type_buf, type_len, 1);
1670 if (oi->typename)
1671 strbuf_add(oi->typename, type_buf, type_len);
1673 * Set type to 0 if its an unknown object and
1674 * we're obtaining the type using '--allow-unkown-type'
1675 * option.
1677 if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
1678 type = 0;
1679 else if (type < 0)
1680 die("invalid object type");
1681 if (oi->typep)
1682 *oi->typep = type;
1685 * The length must follow immediately, and be in canonical
1686 * decimal format (ie "010" is not valid).
1688 size = *hdr++ - '0';
1689 if (size > 9)
1690 return -1;
1691 if (size) {
1692 for (;;) {
1693 unsigned long c = *hdr - '0';
1694 if (c > 9)
1695 break;
1696 hdr++;
1697 size = size * 10 + c;
1701 if (oi->sizep)
1702 *oi->sizep = size;
1705 * The length must be followed by a zero byte
1707 return *hdr ? -1 : type;
1710 int parse_sha1_header(const char *hdr, unsigned long *sizep)
1712 struct object_info oi;
1714 oi.sizep = sizep;
1715 oi.typename = NULL;
1716 oi.typep = NULL;
1717 return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
1720 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1722 int ret;
1723 git_zstream stream;
1724 char hdr[8192];
1726 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1727 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1728 return NULL;
1730 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1733 unsigned long get_size_from_delta(struct packed_git *p,
1734 struct pack_window **w_curs,
1735 off_t curpos)
1737 const unsigned char *data;
1738 unsigned char delta_head[20], *in;
1739 git_zstream stream;
1740 int st;
1742 memset(&stream, 0, sizeof(stream));
1743 stream.next_out = delta_head;
1744 stream.avail_out = sizeof(delta_head);
1746 git_inflate_init(&stream);
1747 do {
1748 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1749 stream.next_in = in;
1750 st = git_inflate(&stream, Z_FINISH);
1751 curpos += stream.next_in - in;
1752 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1753 stream.total_out < sizeof(delta_head));
1754 git_inflate_end(&stream);
1755 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1756 error("delta data unpack-initial failed");
1757 return 0;
1760 /* Examine the initial part of the delta to figure out
1761 * the result size.
1763 data = delta_head;
1765 /* ignore base size */
1766 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1768 /* Read the result size */
1769 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1772 static off_t get_delta_base(struct packed_git *p,
1773 struct pack_window **w_curs,
1774 off_t *curpos,
1775 enum object_type type,
1776 off_t delta_obj_offset)
1778 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1779 off_t base_offset;
1781 /* use_pack() assured us we have [base_info, base_info + 20)
1782 * as a range that we can look at without walking off the
1783 * end of the mapped window. Its actually the hash size
1784 * that is assured. An OFS_DELTA longer than the hash size
1785 * is stupid, as then a REF_DELTA would be smaller to store.
1787 if (type == OBJ_OFS_DELTA) {
1788 unsigned used = 0;
1789 unsigned char c = base_info[used++];
1790 base_offset = c & 127;
1791 while (c & 128) {
1792 base_offset += 1;
1793 if (!base_offset || MSB(base_offset, 7))
1794 return 0; /* overflow */
1795 c = base_info[used++];
1796 base_offset = (base_offset << 7) + (c & 127);
1798 base_offset = delta_obj_offset - base_offset;
1799 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1800 return 0; /* out of bound */
1801 *curpos += used;
1802 } else if (type == OBJ_REF_DELTA) {
1803 /* The base entry _must_ be in the same pack */
1804 base_offset = find_pack_entry_one(base_info, p);
1805 *curpos += 20;
1806 } else
1807 die("I am totally screwed");
1808 return base_offset;
1812 * Like get_delta_base above, but we return the sha1 instead of the pack
1813 * offset. This means it is cheaper for REF deltas (we do not have to do
1814 * the final object lookup), but more expensive for OFS deltas (we
1815 * have to load the revidx to convert the offset back into a sha1).
1817 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1818 struct pack_window **w_curs,
1819 off_t curpos,
1820 enum object_type type,
1821 off_t delta_obj_offset)
1823 if (type == OBJ_REF_DELTA) {
1824 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1825 return base;
1826 } else if (type == OBJ_OFS_DELTA) {
1827 struct revindex_entry *revidx;
1828 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1829 type, delta_obj_offset);
1831 if (!base_offset)
1832 return NULL;
1834 revidx = find_pack_revindex(p, base_offset);
1835 if (!revidx)
1836 return NULL;
1838 return nth_packed_object_sha1(p, revidx->nr);
1839 } else
1840 return NULL;
1843 int unpack_object_header(struct packed_git *p,
1844 struct pack_window **w_curs,
1845 off_t *curpos,
1846 unsigned long *sizep)
1848 unsigned char *base;
1849 unsigned long left;
1850 unsigned long used;
1851 enum object_type type;
1853 /* use_pack() assures us we have [base, base + 20) available
1854 * as a range that we can look at. (Its actually the hash
1855 * size that is assured.) With our object header encoding
1856 * the maximum deflated object size is 2^137, which is just
1857 * insane, so we know won't exceed what we have been given.
1859 base = use_pack(p, w_curs, *curpos, &left);
1860 used = unpack_object_header_buffer(base, left, &type, sizep);
1861 if (!used) {
1862 type = OBJ_BAD;
1863 } else
1864 *curpos += used;
1866 return type;
1869 static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1871 int type;
1872 struct revindex_entry *revidx;
1873 const unsigned char *sha1;
1874 revidx = find_pack_revindex(p, obj_offset);
1875 if (!revidx)
1876 return OBJ_BAD;
1877 sha1 = nth_packed_object_sha1(p, revidx->nr);
1878 mark_bad_packed_object(p, sha1);
1879 type = sha1_object_info(sha1, NULL);
1880 if (type <= OBJ_NONE)
1881 return OBJ_BAD;
1882 return type;
1885 #define POI_STACK_PREALLOC 64
1887 static enum object_type packed_to_object_type(struct packed_git *p,
1888 off_t obj_offset,
1889 enum object_type type,
1890 struct pack_window **w_curs,
1891 off_t curpos)
1893 off_t small_poi_stack[POI_STACK_PREALLOC];
1894 off_t *poi_stack = small_poi_stack;
1895 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1897 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1898 off_t base_offset;
1899 unsigned long size;
1900 /* Push the object we're going to leave behind */
1901 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1902 poi_stack_alloc = alloc_nr(poi_stack_nr);
1903 poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
1904 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1905 } else {
1906 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1908 poi_stack[poi_stack_nr++] = obj_offset;
1909 /* If parsing the base offset fails, just unwind */
1910 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1911 if (!base_offset)
1912 goto unwind;
1913 curpos = obj_offset = base_offset;
1914 type = unpack_object_header(p, w_curs, &curpos, &size);
1915 if (type <= OBJ_NONE) {
1916 /* If getting the base itself fails, we first
1917 * retry the base, otherwise unwind */
1918 type = retry_bad_packed_offset(p, base_offset);
1919 if (type > OBJ_NONE)
1920 goto out;
1921 goto unwind;
1925 switch (type) {
1926 case OBJ_BAD:
1927 case OBJ_COMMIT:
1928 case OBJ_TREE:
1929 case OBJ_BLOB:
1930 case OBJ_TAG:
1931 break;
1932 default:
1933 error("unknown object type %i at offset %"PRIuMAX" in %s",
1934 type, (uintmax_t)obj_offset, p->pack_name);
1935 type = OBJ_BAD;
1938 out:
1939 if (poi_stack != small_poi_stack)
1940 free(poi_stack);
1941 return type;
1943 unwind:
1944 while (poi_stack_nr) {
1945 obj_offset = poi_stack[--poi_stack_nr];
1946 type = retry_bad_packed_offset(p, obj_offset);
1947 if (type > OBJ_NONE)
1948 goto out;
1950 type = OBJ_BAD;
1951 goto out;
1954 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1955 struct object_info *oi)
1957 struct pack_window *w_curs = NULL;
1958 unsigned long size;
1959 off_t curpos = obj_offset;
1960 enum object_type type;
1963 * We always get the representation type, but only convert it to
1964 * a "real" type later if the caller is interested.
1966 type = unpack_object_header(p, &w_curs, &curpos, &size);
1968 if (oi->sizep) {
1969 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1970 off_t tmp_pos = curpos;
1971 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1972 type, obj_offset);
1973 if (!base_offset) {
1974 type = OBJ_BAD;
1975 goto out;
1977 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1978 if (*oi->sizep == 0) {
1979 type = OBJ_BAD;
1980 goto out;
1982 } else {
1983 *oi->sizep = size;
1987 if (oi->disk_sizep) {
1988 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1989 *oi->disk_sizep = revidx[1].offset - obj_offset;
1992 if (oi->typep) {
1993 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
1994 if (*oi->typep < 0) {
1995 type = OBJ_BAD;
1996 goto out;
2000 if (oi->delta_base_sha1) {
2001 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2002 const unsigned char *base;
2004 base = get_delta_base_sha1(p, &w_curs, curpos,
2005 type, obj_offset);
2006 if (!base) {
2007 type = OBJ_BAD;
2008 goto out;
2011 hashcpy(oi->delta_base_sha1, base);
2012 } else
2013 hashclr(oi->delta_base_sha1);
2016 out:
2017 unuse_pack(&w_curs);
2018 return type;
2021 static void *unpack_compressed_entry(struct packed_git *p,
2022 struct pack_window **w_curs,
2023 off_t curpos,
2024 unsigned long size)
2026 int st;
2027 git_zstream stream;
2028 unsigned char *buffer, *in;
2030 buffer = xmallocz_gently(size);
2031 if (!buffer)
2032 return NULL;
2033 memset(&stream, 0, sizeof(stream));
2034 stream.next_out = buffer;
2035 stream.avail_out = size + 1;
2037 git_inflate_init(&stream);
2038 do {
2039 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2040 stream.next_in = in;
2041 st = git_inflate(&stream, Z_FINISH);
2042 if (!stream.avail_out)
2043 break; /* the payload is larger than it should be */
2044 curpos += stream.next_in - in;
2045 } while (st == Z_OK || st == Z_BUF_ERROR);
2046 git_inflate_end(&stream);
2047 if ((st != Z_STREAM_END) || stream.total_out != size) {
2048 free(buffer);
2049 return NULL;
2052 return buffer;
2055 #define MAX_DELTA_CACHE (256)
2057 static size_t delta_base_cached;
2059 static struct delta_base_cache_lru_list {
2060 struct delta_base_cache_lru_list *prev;
2061 struct delta_base_cache_lru_list *next;
2062 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
2064 static struct delta_base_cache_entry {
2065 struct delta_base_cache_lru_list lru;
2066 void *data;
2067 struct packed_git *p;
2068 off_t base_offset;
2069 unsigned long size;
2070 enum object_type type;
2071 } delta_base_cache[MAX_DELTA_CACHE];
2073 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
2075 unsigned long hash;
2077 hash = (unsigned long)p + (unsigned long)base_offset;
2078 hash += (hash >> 8) + (hash >> 16);
2079 return hash % MAX_DELTA_CACHE;
2082 static struct delta_base_cache_entry *
2083 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
2085 unsigned long hash = pack_entry_hash(p, base_offset);
2086 return delta_base_cache + hash;
2089 static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
2090 struct packed_git *p, off_t base_offset)
2092 return (ent->data && ent->p == p && ent->base_offset == base_offset);
2095 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2097 struct delta_base_cache_entry *ent;
2098 ent = get_delta_base_cache_entry(p, base_offset);
2099 return eq_delta_base_cache_entry(ent, p, base_offset);
2102 static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2104 ent->data = NULL;
2105 ent->lru.next->prev = ent->lru.prev;
2106 ent->lru.prev->next = ent->lru.next;
2107 delta_base_cached -= ent->size;
2110 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
2111 unsigned long *base_size, enum object_type *type, int keep_cache)
2113 struct delta_base_cache_entry *ent;
2114 void *ret;
2116 ent = get_delta_base_cache_entry(p, base_offset);
2118 if (!eq_delta_base_cache_entry(ent, p, base_offset))
2119 return unpack_entry(p, base_offset, type, base_size);
2121 ret = ent->data;
2123 if (!keep_cache)
2124 clear_delta_base_cache_entry(ent);
2125 else
2126 ret = xmemdupz(ent->data, ent->size);
2127 *type = ent->type;
2128 *base_size = ent->size;
2129 return ret;
2132 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2134 if (ent->data) {
2135 free(ent->data);
2136 ent->data = NULL;
2137 ent->lru.next->prev = ent->lru.prev;
2138 ent->lru.prev->next = ent->lru.next;
2139 delta_base_cached -= ent->size;
2143 void clear_delta_base_cache(void)
2145 unsigned long p;
2146 for (p = 0; p < MAX_DELTA_CACHE; p++)
2147 release_delta_base_cache(&delta_base_cache[p]);
2150 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2151 void *base, unsigned long base_size, enum object_type type)
2153 unsigned long hash = pack_entry_hash(p, base_offset);
2154 struct delta_base_cache_entry *ent = delta_base_cache + hash;
2155 struct delta_base_cache_lru_list *lru;
2157 release_delta_base_cache(ent);
2158 delta_base_cached += base_size;
2160 for (lru = delta_base_cache_lru.next;
2161 delta_base_cached > delta_base_cache_limit
2162 && lru != &delta_base_cache_lru;
2163 lru = lru->next) {
2164 struct delta_base_cache_entry *f = (void *)lru;
2165 if (f->type == OBJ_BLOB)
2166 release_delta_base_cache(f);
2168 for (lru = delta_base_cache_lru.next;
2169 delta_base_cached > delta_base_cache_limit
2170 && lru != &delta_base_cache_lru;
2171 lru = lru->next) {
2172 struct delta_base_cache_entry *f = (void *)lru;
2173 release_delta_base_cache(f);
2176 ent->p = p;
2177 ent->base_offset = base_offset;
2178 ent->type = type;
2179 ent->data = base;
2180 ent->size = base_size;
2181 ent->lru.next = &delta_base_cache_lru;
2182 ent->lru.prev = delta_base_cache_lru.prev;
2183 delta_base_cache_lru.prev->next = &ent->lru;
2184 delta_base_cache_lru.prev = &ent->lru;
2187 static void *read_object(const unsigned char *sha1, enum object_type *type,
2188 unsigned long *size);
2190 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2192 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2193 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2194 p->pack_name, (uintmax_t)obj_offset);
2197 int do_check_packed_object_crc;
2199 #define UNPACK_ENTRY_STACK_PREALLOC 64
2200 struct unpack_entry_stack_ent {
2201 off_t obj_offset;
2202 off_t curpos;
2203 unsigned long size;
2206 void *unpack_entry(struct packed_git *p, off_t obj_offset,
2207 enum object_type *final_type, unsigned long *final_size)
2209 struct pack_window *w_curs = NULL;
2210 off_t curpos = obj_offset;
2211 void *data = NULL;
2212 unsigned long size;
2213 enum object_type type;
2214 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2215 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2216 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2217 int base_from_cache = 0;
2219 write_pack_access_log(p, obj_offset);
2221 /* PHASE 1: drill down to the innermost base object */
2222 for (;;) {
2223 off_t base_offset;
2224 int i;
2225 struct delta_base_cache_entry *ent;
2227 ent = get_delta_base_cache_entry(p, curpos);
2228 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2229 type = ent->type;
2230 data = ent->data;
2231 size = ent->size;
2232 clear_delta_base_cache_entry(ent);
2233 base_from_cache = 1;
2234 break;
2237 if (do_check_packed_object_crc && p->index_version > 1) {
2238 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2239 unsigned long len = revidx[1].offset - obj_offset;
2240 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2241 const unsigned char *sha1 =
2242 nth_packed_object_sha1(p, revidx->nr);
2243 error("bad packed object CRC for %s",
2244 sha1_to_hex(sha1));
2245 mark_bad_packed_object(p, sha1);
2246 unuse_pack(&w_curs);
2247 return NULL;
2251 type = unpack_object_header(p, &w_curs, &curpos, &size);
2252 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2253 break;
2255 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2256 if (!base_offset) {
2257 error("failed to validate delta base reference "
2258 "at offset %"PRIuMAX" from %s",
2259 (uintmax_t)curpos, p->pack_name);
2260 /* bail to phase 2, in hopes of recovery */
2261 data = NULL;
2262 break;
2265 /* push object, proceed to base */
2266 if (delta_stack_nr >= delta_stack_alloc
2267 && delta_stack == small_delta_stack) {
2268 delta_stack_alloc = alloc_nr(delta_stack_nr);
2269 delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
2270 memcpy(delta_stack, small_delta_stack,
2271 sizeof(*delta_stack)*delta_stack_nr);
2272 } else {
2273 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2275 i = delta_stack_nr++;
2276 delta_stack[i].obj_offset = obj_offset;
2277 delta_stack[i].curpos = curpos;
2278 delta_stack[i].size = size;
2280 curpos = obj_offset = base_offset;
2283 /* PHASE 2: handle the base */
2284 switch (type) {
2285 case OBJ_OFS_DELTA:
2286 case OBJ_REF_DELTA:
2287 if (data)
2288 die("BUG in unpack_entry: left loop at a valid delta");
2289 break;
2290 case OBJ_COMMIT:
2291 case OBJ_TREE:
2292 case OBJ_BLOB:
2293 case OBJ_TAG:
2294 if (!base_from_cache)
2295 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2296 break;
2297 default:
2298 data = NULL;
2299 error("unknown object type %i at offset %"PRIuMAX" in %s",
2300 type, (uintmax_t)obj_offset, p->pack_name);
2303 /* PHASE 3: apply deltas in order */
2305 /* invariants:
2306 * 'data' holds the base data, or NULL if there was corruption
2308 while (delta_stack_nr) {
2309 void *delta_data;
2310 void *base = data;
2311 unsigned long delta_size, base_size = size;
2312 int i;
2314 data = NULL;
2316 if (base)
2317 add_delta_base_cache(p, obj_offset, base, base_size, type);
2319 if (!base) {
2321 * We're probably in deep shit, but let's try to fetch
2322 * the required base anyway from another pack or loose.
2323 * This is costly but should happen only in the presence
2324 * of a corrupted pack, and is better than failing outright.
2326 struct revindex_entry *revidx;
2327 const unsigned char *base_sha1;
2328 revidx = find_pack_revindex(p, obj_offset);
2329 if (revidx) {
2330 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2331 error("failed to read delta base object %s"
2332 " at offset %"PRIuMAX" from %s",
2333 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2334 p->pack_name);
2335 mark_bad_packed_object(p, base_sha1);
2336 base = read_object(base_sha1, &type, &base_size);
2340 i = --delta_stack_nr;
2341 obj_offset = delta_stack[i].obj_offset;
2342 curpos = delta_stack[i].curpos;
2343 delta_size = delta_stack[i].size;
2345 if (!base)
2346 continue;
2348 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2350 if (!delta_data) {
2351 error("failed to unpack compressed delta "
2352 "at offset %"PRIuMAX" from %s",
2353 (uintmax_t)curpos, p->pack_name);
2354 data = NULL;
2355 continue;
2358 data = patch_delta(base, base_size,
2359 delta_data, delta_size,
2360 &size);
2363 * We could not apply the delta; warn the user, but keep going.
2364 * Our failure will be noticed either in the next iteration of
2365 * the loop, or if this is the final delta, in the caller when
2366 * we return NULL. Those code paths will take care of making
2367 * a more explicit warning and retrying with another copy of
2368 * the object.
2370 if (!data)
2371 error("failed to apply delta");
2373 free(delta_data);
2376 *final_type = type;
2377 *final_size = size;
2379 unuse_pack(&w_curs);
2381 if (delta_stack != small_delta_stack)
2382 free(delta_stack);
2384 return data;
2387 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2388 uint32_t n)
2390 const unsigned char *index = p->index_data;
2391 if (!index) {
2392 if (open_pack_index(p))
2393 return NULL;
2394 index = p->index_data;
2396 if (n >= p->num_objects)
2397 return NULL;
2398 index += 4 * 256;
2399 if (p->index_version == 1) {
2400 return index + 24 * n + 4;
2401 } else {
2402 index += 8;
2403 return index + 20 * n;
2407 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2409 const unsigned char *index = p->index_data;
2410 index += 4 * 256;
2411 if (p->index_version == 1) {
2412 return ntohl(*((uint32_t *)(index + 24 * n)));
2413 } else {
2414 uint32_t off;
2415 index += 8 + p->num_objects * (20 + 4);
2416 off = ntohl(*((uint32_t *)(index + 4 * n)));
2417 if (!(off & 0x80000000))
2418 return off;
2419 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2420 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2421 ntohl(*((uint32_t *)(index + 4)));
2425 off_t find_pack_entry_one(const unsigned char *sha1,
2426 struct packed_git *p)
2428 const uint32_t *level1_ofs = p->index_data;
2429 const unsigned char *index = p->index_data;
2430 unsigned hi, lo, stride;
2431 static int use_lookup = -1;
2432 static int debug_lookup = -1;
2434 if (debug_lookup < 0)
2435 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2437 if (!index) {
2438 if (open_pack_index(p))
2439 return 0;
2440 level1_ofs = p->index_data;
2441 index = p->index_data;
2443 if (p->index_version > 1) {
2444 level1_ofs += 2;
2445 index += 8;
2447 index += 4 * 256;
2448 hi = ntohl(level1_ofs[*sha1]);
2449 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2450 if (p->index_version > 1) {
2451 stride = 20;
2452 } else {
2453 stride = 24;
2454 index += 4;
2457 if (debug_lookup)
2458 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2459 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2461 if (use_lookup < 0)
2462 use_lookup = !!getenv("GIT_USE_LOOKUP");
2463 if (use_lookup) {
2464 int pos = sha1_entry_pos(index, stride, 0,
2465 lo, hi, p->num_objects, sha1);
2466 if (pos < 0)
2467 return 0;
2468 return nth_packed_object_offset(p, pos);
2471 do {
2472 unsigned mi = (lo + hi) / 2;
2473 int cmp = hashcmp(index + mi * stride, sha1);
2475 if (debug_lookup)
2476 printf("lo %u hi %u rg %u mi %u\n",
2477 lo, hi, hi - lo, mi);
2478 if (!cmp)
2479 return nth_packed_object_offset(p, mi);
2480 if (cmp > 0)
2481 hi = mi;
2482 else
2483 lo = mi+1;
2484 } while (lo < hi);
2485 return 0;
2488 int is_pack_valid(struct packed_git *p)
2490 /* An already open pack is known to be valid. */
2491 if (p->pack_fd != -1)
2492 return 1;
2494 /* If the pack has one window completely covering the
2495 * file size, the pack is known to be valid even if
2496 * the descriptor is not currently open.
2498 if (p->windows) {
2499 struct pack_window *w = p->windows;
2501 if (!w->offset && w->len == p->pack_size)
2502 return 1;
2505 /* Force the pack to open to prove its valid. */
2506 return !open_packed_git(p);
2509 static int fill_pack_entry(const unsigned char *sha1,
2510 struct pack_entry *e,
2511 struct packed_git *p)
2513 off_t offset;
2515 if (p->num_bad_objects) {
2516 unsigned i;
2517 for (i = 0; i < p->num_bad_objects; i++)
2518 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2519 return 0;
2522 offset = find_pack_entry_one(sha1, p);
2523 if (!offset)
2524 return 0;
2527 * We are about to tell the caller where they can locate the
2528 * requested object. We better make sure the packfile is
2529 * still here and can be accessed before supplying that
2530 * answer, as it may have been deleted since the index was
2531 * loaded!
2533 if (!is_pack_valid(p))
2534 return 0;
2535 e->offset = offset;
2536 e->p = p;
2537 hashcpy(e->sha1, sha1);
2538 return 1;
2542 * Iff a pack file contains the object named by sha1, return true and
2543 * store its location to e.
2545 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2547 struct packed_git *p;
2549 prepare_packed_git();
2550 if (!packed_git)
2551 return 0;
2553 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2554 return 1;
2556 for (p = packed_git; p; p = p->next) {
2557 if (p == last_found_pack)
2558 continue; /* we already checked this one */
2560 if (fill_pack_entry(sha1, e, p)) {
2561 last_found_pack = p;
2562 return 1;
2565 return 0;
2568 struct packed_git *find_sha1_pack(const unsigned char *sha1,
2569 struct packed_git *packs)
2571 struct packed_git *p;
2573 for (p = packs; p; p = p->next) {
2574 if (find_pack_entry_one(sha1, p))
2575 return p;
2577 return NULL;
2581 static int sha1_loose_object_info(const unsigned char *sha1,
2582 struct object_info *oi,
2583 int flags)
2585 int status = 0;
2586 unsigned long mapsize;
2587 void *map;
2588 git_zstream stream;
2589 char hdr[32];
2590 struct strbuf hdrbuf = STRBUF_INIT;
2592 if (oi->delta_base_sha1)
2593 hashclr(oi->delta_base_sha1);
2596 * If we don't care about type or size, then we don't
2597 * need to look inside the object at all. Note that we
2598 * do not optimize out the stat call, even if the
2599 * caller doesn't care about the disk-size, since our
2600 * return value implicitly indicates whether the
2601 * object even exists.
2603 if (!oi->typep && !oi->typename && !oi->sizep) {
2604 struct stat st;
2605 if (stat_sha1_file(sha1, &st) < 0)
2606 return -1;
2607 if (oi->disk_sizep)
2608 *oi->disk_sizep = st.st_size;
2609 return 0;
2612 map = map_sha1_file(sha1, &mapsize);
2613 if (!map)
2614 return -1;
2615 if (oi->disk_sizep)
2616 *oi->disk_sizep = mapsize;
2617 if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
2618 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2619 status = error("unable to unpack %s header with --allow-unknown-type",
2620 sha1_to_hex(sha1));
2621 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2622 status = error("unable to unpack %s header",
2623 sha1_to_hex(sha1));
2624 if (status < 0)
2625 ; /* Do nothing */
2626 else if (hdrbuf.len) {
2627 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2628 status = error("unable to parse %s header with --allow-unknown-type",
2629 sha1_to_hex(sha1));
2630 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
2631 status = error("unable to parse %s header", sha1_to_hex(sha1));
2632 git_inflate_end(&stream);
2633 munmap(map, mapsize);
2634 if (status && oi->typep)
2635 *oi->typep = status;
2636 strbuf_release(&hdrbuf);
2637 return 0;
2640 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
2642 struct cached_object *co;
2643 struct pack_entry e;
2644 int rtype;
2645 enum object_type real_type;
2646 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
2648 co = find_cached_object(real);
2649 if (co) {
2650 if (oi->typep)
2651 *(oi->typep) = co->type;
2652 if (oi->sizep)
2653 *(oi->sizep) = co->size;
2654 if (oi->disk_sizep)
2655 *(oi->disk_sizep) = 0;
2656 if (oi->delta_base_sha1)
2657 hashclr(oi->delta_base_sha1);
2658 if (oi->typename)
2659 strbuf_addstr(oi->typename, typename(co->type));
2660 oi->whence = OI_CACHED;
2661 return 0;
2664 if (!find_pack_entry(real, &e)) {
2665 /* Most likely it's a loose object. */
2666 if (!sha1_loose_object_info(real, oi, flags)) {
2667 oi->whence = OI_LOOSE;
2668 return 0;
2671 /* Not a loose object; someone else may have just packed it. */
2672 reprepare_packed_git();
2673 if (!find_pack_entry(real, &e))
2674 return -1;
2678 * packed_object_info() does not follow the delta chain to
2679 * find out the real type, unless it is given oi->typep.
2681 if (oi->typename && !oi->typep)
2682 oi->typep = &real_type;
2684 rtype = packed_object_info(e.p, e.offset, oi);
2685 if (rtype < 0) {
2686 mark_bad_packed_object(e.p, real);
2687 if (oi->typep == &real_type)
2688 oi->typep = NULL;
2689 return sha1_object_info_extended(real, oi, 0);
2690 } else if (in_delta_base_cache(e.p, e.offset)) {
2691 oi->whence = OI_DBCACHED;
2692 } else {
2693 oi->whence = OI_PACKED;
2694 oi->u.packed.offset = e.offset;
2695 oi->u.packed.pack = e.p;
2696 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2697 rtype == OBJ_OFS_DELTA);
2699 if (oi->typename)
2700 strbuf_addstr(oi->typename, typename(*oi->typep));
2701 if (oi->typep == &real_type)
2702 oi->typep = NULL;
2704 return 0;
2707 /* returns enum object_type or negative */
2708 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2710 enum object_type type;
2711 struct object_info oi = {NULL};
2713 oi.typep = &type;
2714 oi.sizep = sizep;
2715 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
2716 return -1;
2717 return type;
2720 static void *read_packed_sha1(const unsigned char *sha1,
2721 enum object_type *type, unsigned long *size)
2723 struct pack_entry e;
2724 void *data;
2726 if (!find_pack_entry(sha1, &e))
2727 return NULL;
2728 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2729 if (!data) {
2731 * We're probably in deep shit, but let's try to fetch
2732 * the required object anyway from another pack or loose.
2733 * This should happen only in the presence of a corrupted
2734 * pack, and is better than failing outright.
2736 error("failed to read object %s at offset %"PRIuMAX" from %s",
2737 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2738 mark_bad_packed_object(e.p, sha1);
2739 data = read_object(sha1, type, size);
2741 return data;
2744 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2745 unsigned char *sha1)
2747 struct cached_object *co;
2749 hash_sha1_file(buf, len, typename(type), sha1);
2750 if (has_sha1_file(sha1) || find_cached_object(sha1))
2751 return 0;
2752 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
2753 co = &cached_objects[cached_object_nr++];
2754 co->size = len;
2755 co->type = type;
2756 co->buf = xmalloc(len);
2757 memcpy(co->buf, buf, len);
2758 hashcpy(co->sha1, sha1);
2759 return 0;
2762 static void *read_object(const unsigned char *sha1, enum object_type *type,
2763 unsigned long *size)
2765 unsigned long mapsize;
2766 void *map, *buf;
2767 struct cached_object *co;
2769 co = find_cached_object(sha1);
2770 if (co) {
2771 *type = co->type;
2772 *size = co->size;
2773 return xmemdupz(co->buf, co->size);
2776 buf = read_packed_sha1(sha1, type, size);
2777 if (buf)
2778 return buf;
2779 map = map_sha1_file(sha1, &mapsize);
2780 if (map) {
2781 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2782 munmap(map, mapsize);
2783 return buf;
2785 reprepare_packed_git();
2786 return read_packed_sha1(sha1, type, size);
2790 * This function dies on corrupt objects; the callers who want to
2791 * deal with them should arrange to call read_object() and give error
2792 * messages themselves.
2794 void *read_sha1_file_extended(const unsigned char *sha1,
2795 enum object_type *type,
2796 unsigned long *size,
2797 unsigned flag)
2799 void *data;
2800 const struct packed_git *p;
2801 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
2803 errno = 0;
2804 data = read_object(repl, type, size);
2805 if (data)
2806 return data;
2808 if (errno && errno != ENOENT)
2809 die_errno("failed to read object %s", sha1_to_hex(sha1));
2811 /* die if we replaced an object with one that does not exist */
2812 if (repl != sha1)
2813 die("replacement %s not found for %s",
2814 sha1_to_hex(repl), sha1_to_hex(sha1));
2816 if (has_loose_object(repl)) {
2817 const char *path = sha1_file_name(sha1);
2819 die("loose object %s (stored in %s) is corrupt",
2820 sha1_to_hex(repl), path);
2823 if ((p = has_packed_and_bad(repl)) != NULL)
2824 die("packed object %s (stored in %s) is corrupt",
2825 sha1_to_hex(repl), p->pack_name);
2827 return NULL;
2830 void *read_object_with_reference(const unsigned char *sha1,
2831 const char *required_type_name,
2832 unsigned long *size,
2833 unsigned char *actual_sha1_return)
2835 enum object_type type, required_type;
2836 void *buffer;
2837 unsigned long isize;
2838 unsigned char actual_sha1[20];
2840 required_type = type_from_string(required_type_name);
2841 hashcpy(actual_sha1, sha1);
2842 while (1) {
2843 int ref_length = -1;
2844 const char *ref_type = NULL;
2846 buffer = read_sha1_file(actual_sha1, &type, &isize);
2847 if (!buffer)
2848 return NULL;
2849 if (type == required_type) {
2850 *size = isize;
2851 if (actual_sha1_return)
2852 hashcpy(actual_sha1_return, actual_sha1);
2853 return buffer;
2855 /* Handle references */
2856 else if (type == OBJ_COMMIT)
2857 ref_type = "tree ";
2858 else if (type == OBJ_TAG)
2859 ref_type = "object ";
2860 else {
2861 free(buffer);
2862 return NULL;
2864 ref_length = strlen(ref_type);
2866 if (ref_length + 40 > isize ||
2867 memcmp(buffer, ref_type, ref_length) ||
2868 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2869 free(buffer);
2870 return NULL;
2872 free(buffer);
2873 /* Now we have the ID of the referred-to object in
2874 * actual_sha1. Check again. */
2878 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2879 const char *type, unsigned char *sha1,
2880 char *hdr, int *hdrlen)
2882 git_SHA_CTX c;
2884 /* Generate the header */
2885 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2887 /* Sha1.. */
2888 git_SHA1_Init(&c);
2889 git_SHA1_Update(&c, hdr, *hdrlen);
2890 git_SHA1_Update(&c, buf, len);
2891 git_SHA1_Final(sha1, &c);
2895 * Move the just written object into its final resting place.
2896 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2897 * "moving" is only a part of what it does, when no patch between
2898 * master to pu changes the call sites of this function.
2900 int move_temp_to_file(const char *tmpfile, const char *filename)
2902 int ret = 0;
2904 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2905 goto try_rename;
2906 else if (link(tmpfile, filename))
2907 ret = errno;
2910 * Coda hack - coda doesn't like cross-directory links,
2911 * so we fall back to a rename, which will mean that it
2912 * won't be able to check collisions, but that's not a
2913 * big deal.
2915 * The same holds for FAT formatted media.
2917 * When this succeeds, we just return. We have nothing
2918 * left to unlink.
2920 if (ret && ret != EEXIST) {
2921 try_rename:
2922 if (!rename(tmpfile, filename))
2923 goto out;
2924 ret = errno;
2926 unlink_or_warn(tmpfile);
2927 if (ret) {
2928 if (ret != EEXIST) {
2929 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
2931 /* FIXME!!! Collision check here ? */
2934 out:
2935 if (adjust_shared_perm(filename))
2936 return error("unable to set permission to '%s'", filename);
2937 return 0;
2940 static int write_buffer(int fd, const void *buf, size_t len)
2942 if (write_in_full(fd, buf, len) < 0)
2943 return error("file write error (%s)", strerror(errno));
2944 return 0;
2947 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2948 unsigned char *sha1)
2950 char hdr[32];
2951 int hdrlen;
2952 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2953 return 0;
2956 /* Finalize a file on disk, and close it. */
2957 static void close_sha1_file(int fd)
2959 if (fsync_object_files)
2960 fsync_or_die(fd, "sha1 file");
2961 if (close(fd) != 0)
2962 die_errno("error when closing sha1 file");
2965 /* Size of directory component, including the ending '/' */
2966 static inline int directory_size(const char *filename)
2968 const char *s = strrchr(filename, '/');
2969 if (!s)
2970 return 0;
2971 return s - filename + 1;
2975 * This creates a temporary file in the same directory as the final
2976 * 'filename'
2978 * We want to avoid cross-directory filename renames, because those
2979 * can have problems on various filesystems (FAT, NFS, Coda).
2981 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2983 int fd, dirlen = directory_size(filename);
2985 if (dirlen + 20 > bufsiz) {
2986 errno = ENAMETOOLONG;
2987 return -1;
2989 memcpy(buffer, filename, dirlen);
2990 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2991 fd = git_mkstemp_mode(buffer, 0444);
2992 if (fd < 0 && dirlen && errno == ENOENT) {
2993 /* Make sure the directory exists */
2994 memcpy(buffer, filename, dirlen);
2995 buffer[dirlen-1] = 0;
2996 if (mkdir(buffer, 0777) && errno != EEXIST)
2997 return -1;
2998 if (adjust_shared_perm(buffer))
2999 return -1;
3001 /* Try again */
3002 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
3003 fd = git_mkstemp_mode(buffer, 0444);
3005 return fd;
3008 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
3009 const void *buf, unsigned long len, time_t mtime)
3011 int fd, ret;
3012 unsigned char compressed[4096];
3013 git_zstream stream;
3014 git_SHA_CTX c;
3015 unsigned char parano_sha1[20];
3016 static char tmp_file[PATH_MAX];
3017 const char *filename = sha1_file_name(sha1);
3019 fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
3020 if (fd < 0) {
3021 if (errno == EACCES)
3022 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
3023 else
3024 return error("unable to create temporary file: %s", strerror(errno));
3027 /* Set it up */
3028 git_deflate_init(&stream, zlib_compression_level);
3029 stream.next_out = compressed;
3030 stream.avail_out = sizeof(compressed);
3031 git_SHA1_Init(&c);
3033 /* First header.. */
3034 stream.next_in = (unsigned char *)hdr;
3035 stream.avail_in = hdrlen;
3036 while (git_deflate(&stream, 0) == Z_OK)
3037 ; /* nothing */
3038 git_SHA1_Update(&c, hdr, hdrlen);
3040 /* Then the data itself.. */
3041 stream.next_in = (void *)buf;
3042 stream.avail_in = len;
3043 do {
3044 unsigned char *in0 = stream.next_in;
3045 ret = git_deflate(&stream, Z_FINISH);
3046 git_SHA1_Update(&c, in0, stream.next_in - in0);
3047 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3048 die("unable to write sha1 file");
3049 stream.next_out = compressed;
3050 stream.avail_out = sizeof(compressed);
3051 } while (ret == Z_OK);
3053 if (ret != Z_STREAM_END)
3054 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
3055 ret = git_deflate_end_gently(&stream);
3056 if (ret != Z_OK)
3057 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
3058 git_SHA1_Final(parano_sha1, &c);
3059 if (hashcmp(sha1, parano_sha1) != 0)
3060 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
3062 close_sha1_file(fd);
3064 if (mtime) {
3065 struct utimbuf utb;
3066 utb.actime = mtime;
3067 utb.modtime = mtime;
3068 if (utime(tmp_file, &utb) < 0)
3069 warning("failed utime() on %s: %s",
3070 tmp_file, strerror(errno));
3073 return move_temp_to_file(tmp_file, filename);
3076 static int freshen_loose_object(const unsigned char *sha1)
3078 return check_and_freshen(sha1, 1);
3081 static int freshen_packed_object(const unsigned char *sha1)
3083 struct pack_entry e;
3084 if (!find_pack_entry(sha1, &e))
3085 return 0;
3086 if (e.p->freshened)
3087 return 1;
3088 if (!freshen_file(e.p->pack_name))
3089 return 0;
3090 e.p->freshened = 1;
3091 return 1;
3094 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
3096 char hdr[32];
3097 int hdrlen;
3099 /* Normally if we have it in the pack then we do not bother writing
3100 * it out into .git/objects/??/?{38} file.
3102 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3103 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3104 return 0;
3105 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3108 int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3109 unsigned char *sha1, unsigned flags)
3111 char *header;
3112 int hdrlen, status = 0;
3114 /* type string, SP, %lu of the length plus NUL must fit this */
3115 header = xmalloc(strlen(type) + 32);
3116 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3118 if (!(flags & HASH_WRITE_OBJECT))
3119 goto cleanup;
3120 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3121 goto cleanup;
3122 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3124 cleanup:
3125 free(header);
3126 return status;
3129 int force_object_loose(const unsigned char *sha1, time_t mtime)
3131 void *buf;
3132 unsigned long len;
3133 enum object_type type;
3134 char hdr[32];
3135 int hdrlen;
3136 int ret;
3138 if (has_loose_object(sha1))
3139 return 0;
3140 buf = read_packed_sha1(sha1, &type, &len);
3141 if (!buf)
3142 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
3143 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
3144 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3145 free(buf);
3147 return ret;
3150 int has_pack_index(const unsigned char *sha1)
3152 struct stat st;
3153 if (stat(sha1_pack_index_name(sha1), &st))
3154 return 0;
3155 return 1;
3158 int has_sha1_pack(const unsigned char *sha1)
3160 struct pack_entry e;
3161 return find_pack_entry(sha1, &e);
3164 int has_sha1_file(const unsigned char *sha1)
3166 struct pack_entry e;
3168 if (find_pack_entry(sha1, &e))
3169 return 1;
3170 if (has_loose_object(sha1))
3171 return 1;
3172 reprepare_packed_git();
3173 return find_pack_entry(sha1, &e);
3176 static void check_tree(const void *buf, size_t size)
3178 struct tree_desc desc;
3179 struct name_entry entry;
3181 init_tree_desc(&desc, buf, size);
3182 while (tree_entry(&desc, &entry))
3183 /* do nothing
3184 * tree_entry() will die() on malformed entries */
3188 static void check_commit(const void *buf, size_t size)
3190 struct commit c;
3191 memset(&c, 0, sizeof(c));
3192 if (parse_commit_buffer(&c, buf, size))
3193 die("corrupt commit");
3196 static void check_tag(const void *buf, size_t size)
3198 struct tag t;
3199 memset(&t, 0, sizeof(t));
3200 if (parse_tag_buffer(&t, buf, size))
3201 die("corrupt tag");
3204 static int index_mem(unsigned char *sha1, void *buf, size_t size,
3205 enum object_type type,
3206 const char *path, unsigned flags)
3208 int ret, re_allocated = 0;
3209 int write_object = flags & HASH_WRITE_OBJECT;
3211 if (!type)
3212 type = OBJ_BLOB;
3215 * Convert blobs to git internal format
3217 if ((type == OBJ_BLOB) && path) {
3218 struct strbuf nbuf = STRBUF_INIT;
3219 if (convert_to_git(path, buf, size, &nbuf,
3220 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
3221 buf = strbuf_detach(&nbuf, &size);
3222 re_allocated = 1;
3225 if (flags & HASH_FORMAT_CHECK) {
3226 if (type == OBJ_TREE)
3227 check_tree(buf, size);
3228 if (type == OBJ_COMMIT)
3229 check_commit(buf, size);
3230 if (type == OBJ_TAG)
3231 check_tag(buf, size);
3234 if (write_object)
3235 ret = write_sha1_file(buf, size, typename(type), sha1);
3236 else
3237 ret = hash_sha1_file(buf, size, typename(type), sha1);
3238 if (re_allocated)
3239 free(buf);
3240 return ret;
3243 static int index_stream_convert_blob(unsigned char *sha1, int fd,
3244 const char *path, unsigned flags)
3246 int ret;
3247 const int write_object = flags & HASH_WRITE_OBJECT;
3248 struct strbuf sbuf = STRBUF_INIT;
3250 assert(path);
3251 assert(would_convert_to_git_filter_fd(path));
3253 convert_to_git_filter_fd(path, fd, &sbuf,
3254 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3256 if (write_object)
3257 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3258 sha1);
3259 else
3260 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3261 sha1);
3262 strbuf_release(&sbuf);
3263 return ret;
3266 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3267 const char *path, unsigned flags)
3269 struct strbuf sbuf = STRBUF_INIT;
3270 int ret;
3272 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3273 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3274 else
3275 ret = -1;
3276 strbuf_release(&sbuf);
3277 return ret;
3280 #define SMALL_FILE_SIZE (32*1024)
3282 static int index_core(unsigned char *sha1, int fd, size_t size,
3283 enum object_type type, const char *path,
3284 unsigned flags)
3286 int ret;
3288 if (!size) {
3289 ret = index_mem(sha1, "", size, type, path, flags);
3290 } else if (size <= SMALL_FILE_SIZE) {
3291 char *buf = xmalloc(size);
3292 if (size == read_in_full(fd, buf, size))
3293 ret = index_mem(sha1, buf, size, type, path, flags);
3294 else
3295 ret = error("short read %s", strerror(errno));
3296 free(buf);
3297 } else {
3298 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3299 ret = index_mem(sha1, buf, size, type, path, flags);
3300 munmap(buf, size);
3302 return ret;
3306 * This creates one packfile per large blob unless bulk-checkin
3307 * machinery is "plugged".
3309 * This also bypasses the usual "convert-to-git" dance, and that is on
3310 * purpose. We could write a streaming version of the converting
3311 * functions and insert that before feeding the data to fast-import
3312 * (or equivalent in-core API described above). However, that is
3313 * somewhat complicated, as we do not know the size of the filter
3314 * result, which we need to know beforehand when writing a git object.
3315 * Since the primary motivation for trying to stream from the working
3316 * tree file and to avoid mmaping it in core is to deal with large
3317 * binary blobs, they generally do not want to get any conversion, and
3318 * callers should avoid this code path when filters are requested.
3320 static int index_stream(unsigned char *sha1, int fd, size_t size,
3321 enum object_type type, const char *path,
3322 unsigned flags)
3324 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3327 int index_fd(unsigned char *sha1, int fd, struct stat *st,
3328 enum object_type type, const char *path, unsigned flags)
3330 int ret;
3333 * Call xsize_t() only when needed to avoid potentially unnecessary
3334 * die() for large files.
3336 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3337 ret = index_stream_convert_blob(sha1, fd, path, flags);
3338 else if (!S_ISREG(st->st_mode))
3339 ret = index_pipe(sha1, fd, type, path, flags);
3340 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
3341 (path && would_convert_to_git(path)))
3342 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3343 flags);
3344 else
3345 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3346 flags);
3347 close(fd);
3348 return ret;
3351 int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3353 int fd;
3354 struct strbuf sb = STRBUF_INIT;
3356 switch (st->st_mode & S_IFMT) {
3357 case S_IFREG:
3358 fd = open(path, O_RDONLY);
3359 if (fd < 0)
3360 return error("open(\"%s\"): %s", path,
3361 strerror(errno));
3362 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3363 return error("%s: failed to insert into database",
3364 path);
3365 break;
3366 case S_IFLNK:
3367 if (strbuf_readlink(&sb, path, st->st_size)) {
3368 char *errstr = strerror(errno);
3369 return error("readlink(\"%s\"): %s", path,
3370 errstr);
3372 if (!(flags & HASH_WRITE_OBJECT))
3373 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3374 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3375 return error("%s: failed to insert into database",
3376 path);
3377 strbuf_release(&sb);
3378 break;
3379 case S_IFDIR:
3380 return resolve_gitlink_ref(path, "HEAD", sha1);
3381 default:
3382 return error("%s: unsupported file type", path);
3384 return 0;
3387 int read_pack_header(int fd, struct pack_header *header)
3389 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3390 /* "eof before pack header was fully read" */
3391 return PH_ERROR_EOF;
3393 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3394 /* "protocol error (pack signature mismatch detected)" */
3395 return PH_ERROR_PACK_SIGNATURE;
3396 if (!pack_version_ok(header->hdr_version))
3397 /* "protocol error (pack version unsupported)" */
3398 return PH_ERROR_PROTOCOL;
3399 return 0;
3402 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3404 enum object_type type = sha1_object_info(sha1, NULL);
3405 if (type < 0)
3406 die("%s is not a valid object", sha1_to_hex(sha1));
3407 if (type != expect)
3408 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3409 typename(expect));
3412 static int for_each_file_in_obj_subdir(int subdir_nr,
3413 struct strbuf *path,
3414 each_loose_object_fn obj_cb,
3415 each_loose_cruft_fn cruft_cb,
3416 each_loose_subdir_fn subdir_cb,
3417 void *data)
3419 size_t baselen = path->len;
3420 DIR *dir = opendir(path->buf);
3421 struct dirent *de;
3422 int r = 0;
3424 if (!dir) {
3425 if (errno == ENOENT)
3426 return 0;
3427 return error("unable to open %s: %s", path->buf, strerror(errno));
3430 while ((de = readdir(dir))) {
3431 if (is_dot_or_dotdot(de->d_name))
3432 continue;
3434 strbuf_setlen(path, baselen);
3435 strbuf_addf(path, "/%s", de->d_name);
3437 if (strlen(de->d_name) == 38) {
3438 char hex[41];
3439 unsigned char sha1[20];
3441 snprintf(hex, sizeof(hex), "%02x%s",
3442 subdir_nr, de->d_name);
3443 if (!get_sha1_hex(hex, sha1)) {
3444 if (obj_cb) {
3445 r = obj_cb(sha1, path->buf, data);
3446 if (r)
3447 break;
3449 continue;
3453 if (cruft_cb) {
3454 r = cruft_cb(de->d_name, path->buf, data);
3455 if (r)
3456 break;
3459 strbuf_setlen(path, baselen);
3461 if (!r && subdir_cb)
3462 r = subdir_cb(subdir_nr, path->buf, data);
3464 closedir(dir);
3465 return r;
3468 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
3469 each_loose_object_fn obj_cb,
3470 each_loose_cruft_fn cruft_cb,
3471 each_loose_subdir_fn subdir_cb,
3472 void *data)
3474 size_t baselen = path->len;
3475 int r = 0;
3476 int i;
3478 for (i = 0; i < 256; i++) {
3479 strbuf_addf(path, "/%02x", i);
3480 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
3481 subdir_cb, data);
3482 strbuf_setlen(path, baselen);
3483 if (r)
3484 break;
3487 return r;
3490 int for_each_loose_file_in_objdir(const char *path,
3491 each_loose_object_fn obj_cb,
3492 each_loose_cruft_fn cruft_cb,
3493 each_loose_subdir_fn subdir_cb,
3494 void *data)
3496 struct strbuf buf = STRBUF_INIT;
3497 int r;
3499 strbuf_addstr(&buf, path);
3500 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
3501 subdir_cb, data);
3502 strbuf_release(&buf);
3504 return r;
3507 struct loose_alt_odb_data {
3508 each_loose_object_fn *cb;
3509 void *data;
3512 static int loose_from_alt_odb(struct alternate_object_database *alt,
3513 void *vdata)
3515 struct loose_alt_odb_data *data = vdata;
3516 struct strbuf buf = STRBUF_INIT;
3517 int r;
3519 /* copy base not including trailing '/' */
3520 strbuf_add(&buf, alt->base, alt->name - alt->base - 1);
3521 r = for_each_loose_file_in_objdir_buf(&buf,
3522 data->cb, NULL, NULL,
3523 data->data);
3524 strbuf_release(&buf);
3525 return r;
3528 int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
3530 struct loose_alt_odb_data alt;
3531 int r;
3533 r = for_each_loose_file_in_objdir(get_object_directory(),
3534 cb, NULL, NULL, data);
3535 if (r)
3536 return r;
3538 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
3539 return 0;
3541 alt.cb = cb;
3542 alt.data = data;
3543 return foreach_alt_odb(loose_from_alt_odb, &alt);
3546 static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
3548 uint32_t i;
3549 int r = 0;
3551 for (i = 0; i < p->num_objects; i++) {
3552 const unsigned char *sha1 = nth_packed_object_sha1(p, i);
3554 if (!sha1)
3555 return error("unable to get sha1 of object %u in %s",
3556 i, p->pack_name);
3558 r = cb(sha1, p, i, data);
3559 if (r)
3560 break;
3562 return r;
3565 int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
3567 struct packed_git *p;
3568 int r = 0;
3570 prepare_packed_git();
3571 for (p = packed_git; p; p = p->next) {
3572 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
3573 continue;
3574 r = for_each_object_in_pack(p, cb, data);
3575 if (r)
3576 break;
3578 return r;