Merge tag 'v2.14.1'
[git/raj.git] / sha1_file.c
blobb60ae15f7068c157df6407933ea7ee94a53f0640
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 "config.h"
11 #include "string-list.h"
12 #include "lockfile.h"
13 #include "delta.h"
14 #include "pack.h"
15 #include "blob.h"
16 #include "commit.h"
17 #include "run-command.h"
18 #include "tag.h"
19 #include "tree.h"
20 #include "tree-walk.h"
21 #include "refs.h"
22 #include "pack-revindex.h"
23 #include "sha1-lookup.h"
24 #include "bulk-checkin.h"
25 #include "streaming.h"
26 #include "dir.h"
27 #include "mru.h"
28 #include "list.h"
29 #include "mergesort.h"
30 #include "quote.h"
32 #define SZ_FMT PRIuMAX
33 static inline uintmax_t sz_fmt(size_t s) { return s; }
35 const unsigned char null_sha1[20];
36 const struct object_id null_oid;
37 const struct object_id empty_tree_oid = {
38 EMPTY_TREE_SHA1_BIN_LITERAL
40 const struct object_id empty_blob_oid = {
41 EMPTY_BLOB_SHA1_BIN_LITERAL
45 * This is meant to hold a *small* number of objects that you would
46 * want read_sha1_file() to be able to return, but yet you do not want
47 * to write them into the object store (e.g. a browse-only
48 * application).
50 static struct cached_object {
51 unsigned char sha1[20];
52 enum object_type type;
53 void *buf;
54 unsigned long size;
55 } *cached_objects;
56 static int cached_object_nr, cached_object_alloc;
58 static struct cached_object empty_tree = {
59 EMPTY_TREE_SHA1_BIN_LITERAL,
60 OBJ_TREE,
61 "",
65 static struct cached_object *find_cached_object(const unsigned char *sha1)
67 int i;
68 struct cached_object *co = cached_objects;
70 for (i = 0; i < cached_object_nr; i++, co++) {
71 if (!hashcmp(co->sha1, sha1))
72 return co;
74 if (!hashcmp(sha1, empty_tree.sha1))
75 return &empty_tree;
76 return NULL;
79 int mkdir_in_gitdir(const char *path)
81 if (mkdir(path, 0777)) {
82 int saved_errno = errno;
83 struct stat st;
84 struct strbuf sb = STRBUF_INIT;
86 if (errno != EEXIST)
87 return -1;
89 * Are we looking at a path in a symlinked worktree
90 * whose original repository does not yet have it?
91 * e.g. .git/rr-cache pointing at its original
92 * repository in which the user hasn't performed any
93 * conflict resolution yet?
95 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
96 strbuf_readlink(&sb, path, st.st_size) ||
97 !is_absolute_path(sb.buf) ||
98 mkdir(sb.buf, 0777)) {
99 strbuf_release(&sb);
100 errno = saved_errno;
101 return -1;
103 strbuf_release(&sb);
105 return adjust_shared_perm(path);
108 enum scld_error safe_create_leading_directories(char *path)
110 char *next_component = path + offset_1st_component(path);
111 enum scld_error ret = SCLD_OK;
113 while (ret == SCLD_OK && next_component) {
114 struct stat st;
115 char *slash = next_component, slash_character;
117 while (*slash && !is_dir_sep(*slash))
118 slash++;
120 if (!*slash)
121 break;
123 next_component = slash + 1;
124 while (is_dir_sep(*next_component))
125 next_component++;
126 if (!*next_component)
127 break;
129 slash_character = *slash;
130 *slash = '\0';
131 if (!stat(path, &st)) {
132 /* path exists */
133 if (!S_ISDIR(st.st_mode)) {
134 errno = ENOTDIR;
135 ret = SCLD_EXISTS;
137 } else if (mkdir(path, 0777)) {
138 if (errno == EEXIST &&
139 !stat(path, &st) && S_ISDIR(st.st_mode))
140 ; /* somebody created it since we checked */
141 else if (errno == ENOENT)
143 * Either mkdir() failed because
144 * somebody just pruned the containing
145 * directory, or stat() failed because
146 * the file that was in our way was
147 * just removed. Either way, inform
148 * the caller that it might be worth
149 * trying again:
151 ret = SCLD_VANISHED;
152 else
153 ret = SCLD_FAILED;
154 } else if (adjust_shared_perm(path)) {
155 ret = SCLD_PERMS;
157 *slash = slash_character;
159 return ret;
162 enum scld_error safe_create_leading_directories_const(const char *path)
164 int save_errno;
165 /* path points to cache entries, so xstrdup before messing with it */
166 char *buf = xstrdup(path);
167 enum scld_error result = safe_create_leading_directories(buf);
169 save_errno = errno;
170 free(buf);
171 errno = save_errno;
172 return result;
175 int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
178 * The number of times we will try to remove empty directories
179 * in the way of path. This is only 1 because if another
180 * process is racily creating directories that conflict with
181 * us, we don't want to fight against them.
183 int remove_directories_remaining = 1;
186 * The number of times that we will try to create the
187 * directories containing path. We are willing to attempt this
188 * more than once, because another process could be trying to
189 * clean up empty directories at the same time as we are
190 * trying to create them.
192 int create_directories_remaining = 3;
194 /* A scratch copy of path, filled lazily if we need it: */
195 struct strbuf path_copy = STRBUF_INIT;
197 int ret, save_errno;
199 /* Sanity check: */
200 assert(*path);
202 retry_fn:
203 ret = fn(path, cb);
204 save_errno = errno;
205 if (!ret)
206 goto out;
208 if (errno == EISDIR && remove_directories_remaining-- > 0) {
210 * A directory is in the way. Maybe it is empty; try
211 * to remove it:
213 if (!path_copy.len)
214 strbuf_addstr(&path_copy, path);
216 if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
217 goto retry_fn;
218 } else if (errno == ENOENT && create_directories_remaining-- > 0) {
220 * Maybe the containing directory didn't exist, or
221 * maybe it was just deleted by a process that is
222 * racing with us to clean up empty directories. Try
223 * to create it:
225 enum scld_error scld_result;
227 if (!path_copy.len)
228 strbuf_addstr(&path_copy, path);
230 do {
231 scld_result = safe_create_leading_directories(path_copy.buf);
232 if (scld_result == SCLD_OK)
233 goto retry_fn;
234 } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
237 out:
238 strbuf_release(&path_copy);
239 errno = save_errno;
240 return ret;
243 static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
245 int i;
246 for (i = 0; i < 20; i++) {
247 static char hex[] = "0123456789abcdef";
248 unsigned int val = sha1[i];
249 strbuf_addch(buf, hex[val >> 4]);
250 strbuf_addch(buf, hex[val & 0xf]);
251 if (!i)
252 strbuf_addch(buf, '/');
256 const char *sha1_file_name(const unsigned char *sha1)
258 static struct strbuf buf = STRBUF_INIT;
260 strbuf_reset(&buf);
261 strbuf_addf(&buf, "%s/", get_object_directory());
263 fill_sha1_path(&buf, sha1);
264 return buf.buf;
267 struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
269 strbuf_setlen(&alt->scratch, alt->base_len);
270 return &alt->scratch;
273 static const char *alt_sha1_path(struct alternate_object_database *alt,
274 const unsigned char *sha1)
276 struct strbuf *buf = alt_scratch_buf(alt);
277 fill_sha1_path(buf, sha1);
278 return buf->buf;
281 char *odb_pack_name(struct strbuf *buf,
282 const unsigned char *sha1,
283 const char *ext)
285 strbuf_reset(buf);
286 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
287 sha1_to_hex(sha1), ext);
288 return buf->buf;
291 char *sha1_pack_name(const unsigned char *sha1)
293 static struct strbuf buf = STRBUF_INIT;
294 return odb_pack_name(&buf, sha1, "pack");
297 char *sha1_pack_index_name(const unsigned char *sha1)
299 static struct strbuf buf = STRBUF_INIT;
300 return odb_pack_name(&buf, sha1, "idx");
303 struct alternate_object_database *alt_odb_list;
304 static struct alternate_object_database **alt_odb_tail;
307 * Return non-zero iff the path is usable as an alternate object database.
309 static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
311 struct alternate_object_database *alt;
313 /* Detect cases where alternate disappeared */
314 if (!is_directory(path->buf)) {
315 error("object directory %s does not exist; "
316 "check .git/objects/info/alternates.",
317 path->buf);
318 return 0;
322 * Prevent the common mistake of listing the same
323 * thing twice, or object directory itself.
325 for (alt = alt_odb_list; alt; alt = alt->next) {
326 if (!fspathcmp(path->buf, alt->path))
327 return 0;
329 if (!fspathcmp(path->buf, normalized_objdir))
330 return 0;
332 return 1;
336 * Prepare alternate object database registry.
338 * The variable alt_odb_list points at the list of struct
339 * alternate_object_database. The elements on this list come from
340 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
341 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
342 * whose contents is similar to that environment variable but can be
343 * LF separated. Its base points at a statically allocated buffer that
344 * contains "/the/directory/corresponding/to/.git/objects/...", while
345 * its name points just after the slash at the end of ".git/objects/"
346 * in the example above, and has enough space to hold 40-byte hex
347 * SHA1, an extra slash for the first level indirection, and the
348 * terminating NUL.
350 static int link_alt_odb_entry(const char *entry, const char *relative_base,
351 int depth, const char *normalized_objdir)
353 struct alternate_object_database *ent;
354 struct strbuf pathbuf = STRBUF_INIT;
356 if (!is_absolute_path(entry) && relative_base) {
357 strbuf_realpath(&pathbuf, relative_base, 1);
358 strbuf_addch(&pathbuf, '/');
360 strbuf_addstr(&pathbuf, entry);
362 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
363 error("unable to normalize alternate object path: %s",
364 pathbuf.buf);
365 strbuf_release(&pathbuf);
366 return -1;
370 * The trailing slash after the directory name is given by
371 * this function at the end. Remove duplicates.
373 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
374 strbuf_setlen(&pathbuf, pathbuf.len - 1);
376 if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
377 strbuf_release(&pathbuf);
378 return -1;
381 ent = alloc_alt_odb(pathbuf.buf);
383 /* add the alternate entry */
384 *alt_odb_tail = ent;
385 alt_odb_tail = &(ent->next);
386 ent->next = NULL;
388 /* recursively add alternates */
389 read_info_alternates(pathbuf.buf, depth + 1);
391 strbuf_release(&pathbuf);
392 return 0;
395 static const char *parse_alt_odb_entry(const char *string,
396 int sep,
397 struct strbuf *out)
399 const char *end;
401 strbuf_reset(out);
403 if (*string == '#') {
404 /* comment; consume up to next separator */
405 end = strchrnul(string, sep);
406 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
408 * quoted path; unquote_c_style has copied the
409 * data for us and set "end". Broken quoting (e.g.,
410 * an entry that doesn't end with a quote) falls
411 * back to the unquoted case below.
413 } else {
414 /* normal, unquoted path */
415 end = strchrnul(string, sep);
416 strbuf_add(out, string, end - string);
419 if (*end)
420 end++;
421 return end;
424 static void link_alt_odb_entries(const char *alt, int len, int sep,
425 const char *relative_base, int depth)
427 struct strbuf objdirbuf = STRBUF_INIT;
428 struct strbuf entry = STRBUF_INIT;
430 if (depth > 5) {
431 error("%s: ignoring alternate object stores, nesting too deep.",
432 relative_base);
433 return;
436 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
437 if (strbuf_normalize_path(&objdirbuf) < 0)
438 die("unable to normalize object directory: %s",
439 objdirbuf.buf);
441 while (*alt) {
442 alt = parse_alt_odb_entry(alt, sep, &entry);
443 if (!entry.len)
444 continue;
445 link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
447 strbuf_release(&entry);
448 strbuf_release(&objdirbuf);
451 void read_info_alternates(const char * relative_base, int depth)
453 char *map;
454 size_t mapsz;
455 struct stat st;
456 char *path;
457 int fd;
459 path = xstrfmt("%s/info/alternates", relative_base);
460 fd = git_open(path);
461 free(path);
462 if (fd < 0)
463 return;
464 if (fstat(fd, &st) || (st.st_size == 0)) {
465 close(fd);
466 return;
468 mapsz = xsize_t(st.st_size);
469 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
470 close(fd);
472 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
474 munmap(map, mapsz);
477 struct alternate_object_database *alloc_alt_odb(const char *dir)
479 struct alternate_object_database *ent;
481 FLEX_ALLOC_STR(ent, path, dir);
482 strbuf_init(&ent->scratch, 0);
483 strbuf_addf(&ent->scratch, "%s/", dir);
484 ent->base_len = ent->scratch.len;
486 return ent;
489 void add_to_alternates_file(const char *reference)
491 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
492 char *alts = git_pathdup("objects/info/alternates");
493 FILE *in, *out;
495 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
496 out = fdopen_lock_file(lock, "w");
497 if (!out)
498 die_errno("unable to fdopen alternates lockfile");
500 in = fopen(alts, "r");
501 if (in) {
502 struct strbuf line = STRBUF_INIT;
503 int found = 0;
505 while (strbuf_getline(&line, in) != EOF) {
506 if (!strcmp(reference, line.buf)) {
507 found = 1;
508 break;
510 fprintf_or_die(out, "%s\n", line.buf);
513 strbuf_release(&line);
514 fclose(in);
516 if (found) {
517 rollback_lock_file(lock);
518 lock = NULL;
521 else if (errno != ENOENT)
522 die_errno("unable to read alternates file");
524 if (lock) {
525 fprintf_or_die(out, "%s\n", reference);
526 if (commit_lock_file(lock))
527 die_errno("unable to move new alternates file into place");
528 if (alt_odb_tail)
529 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
531 free(alts);
534 void add_to_alternates_memory(const char *reference)
537 * Make sure alternates are initialized, or else our entry may be
538 * overwritten when they are.
540 prepare_alt_odb();
542 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
546 * Compute the exact path an alternate is at and returns it. In case of
547 * error NULL is returned and the human readable error is added to `err`
548 * `path` may be relative and should point to $GITDIR.
549 * `err` must not be null.
551 char *compute_alternate_path(const char *path, struct strbuf *err)
553 char *ref_git = NULL;
554 const char *repo, *ref_git_s;
555 int seen_error = 0;
557 ref_git_s = real_path_if_valid(path);
558 if (!ref_git_s) {
559 seen_error = 1;
560 strbuf_addf(err, _("path '%s' does not exist"), path);
561 goto out;
562 } else
564 * Beware: read_gitfile(), real_path() and mkpath()
565 * return static buffer
567 ref_git = xstrdup(ref_git_s);
569 repo = read_gitfile(ref_git);
570 if (!repo)
571 repo = read_gitfile(mkpath("%s/.git", ref_git));
572 if (repo) {
573 free(ref_git);
574 ref_git = xstrdup(repo);
577 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
578 char *ref_git_git = mkpathdup("%s/.git", ref_git);
579 free(ref_git);
580 ref_git = ref_git_git;
581 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
582 struct strbuf sb = STRBUF_INIT;
583 seen_error = 1;
584 if (get_common_dir(&sb, ref_git)) {
585 strbuf_addf(err,
586 _("reference repository '%s' as a linked "
587 "checkout is not supported yet."),
588 path);
589 goto out;
592 strbuf_addf(err, _("reference repository '%s' is not a "
593 "local repository."), path);
594 goto out;
597 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
598 strbuf_addf(err, _("reference repository '%s' is shallow"),
599 path);
600 seen_error = 1;
601 goto out;
604 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
605 strbuf_addf(err,
606 _("reference repository '%s' is grafted"),
607 path);
608 seen_error = 1;
609 goto out;
612 out:
613 if (seen_error) {
614 FREE_AND_NULL(ref_git);
617 return ref_git;
620 int foreach_alt_odb(alt_odb_fn fn, void *cb)
622 struct alternate_object_database *ent;
623 int r = 0;
625 prepare_alt_odb();
626 for (ent = alt_odb_list; ent; ent = ent->next) {
627 r = fn(ent, cb);
628 if (r)
629 break;
631 return r;
634 void prepare_alt_odb(void)
636 const char *alt;
638 if (alt_odb_tail)
639 return;
641 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
642 if (!alt) alt = "";
644 alt_odb_tail = &alt_odb_list;
645 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
647 read_info_alternates(get_object_directory(), 0);
650 /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
651 static int freshen_file(const char *fn)
653 struct utimbuf t;
654 t.actime = t.modtime = time(NULL);
655 return !utime(fn, &t);
659 * All of the check_and_freshen functions return 1 if the file exists and was
660 * freshened (if freshening was requested), 0 otherwise. If they return
661 * 0, you should not assume that it is safe to skip a write of the object (it
662 * either does not exist on disk, or has a stale mtime and may be subject to
663 * pruning).
665 int check_and_freshen_file(const char *fn, int freshen)
667 if (access(fn, F_OK))
668 return 0;
669 if (freshen && !freshen_file(fn))
670 return 0;
671 return 1;
674 static int check_and_freshen_local(const unsigned char *sha1, int freshen)
676 return check_and_freshen_file(sha1_file_name(sha1), freshen);
679 static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
681 struct alternate_object_database *alt;
682 prepare_alt_odb();
683 for (alt = alt_odb_list; alt; alt = alt->next) {
684 const char *path = alt_sha1_path(alt, sha1);
685 if (check_and_freshen_file(path, freshen))
686 return 1;
688 return 0;
691 static int check_and_freshen(const unsigned char *sha1, int freshen)
693 return check_and_freshen_local(sha1, freshen) ||
694 check_and_freshen_nonlocal(sha1, freshen);
697 int has_loose_object_nonlocal(const unsigned char *sha1)
699 return check_and_freshen_nonlocal(sha1, 0);
702 static int has_loose_object(const unsigned char *sha1)
704 return check_and_freshen(sha1, 0);
707 static unsigned int pack_used_ctr;
708 static unsigned int pack_mmap_calls;
709 static unsigned int peak_pack_open_windows;
710 static unsigned int pack_open_windows;
711 static unsigned int pack_open_fds;
712 static unsigned int pack_max_fds;
713 static size_t peak_pack_mapped;
714 static size_t pack_mapped;
715 struct packed_git *packed_git;
717 static struct mru packed_git_mru_storage;
718 struct mru *packed_git_mru = &packed_git_mru_storage;
720 void pack_report(void)
722 fprintf(stderr,
723 "pack_report: getpagesize() = %10" SZ_FMT "\n"
724 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
725 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
726 sz_fmt(getpagesize()),
727 sz_fmt(packed_git_window_size),
728 sz_fmt(packed_git_limit));
729 fprintf(stderr,
730 "pack_report: pack_used_ctr = %10u\n"
731 "pack_report: pack_mmap_calls = %10u\n"
732 "pack_report: pack_open_windows = %10u / %10u\n"
733 "pack_report: pack_mapped = "
734 "%10" SZ_FMT " / %10" SZ_FMT "\n",
735 pack_used_ctr,
736 pack_mmap_calls,
737 pack_open_windows, peak_pack_open_windows,
738 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
742 * Open and mmap the index file at path, perform a couple of
743 * consistency checks, then record its information to p. Return 0 on
744 * success.
746 static int check_packed_git_idx(const char *path, struct packed_git *p)
748 void *idx_map;
749 struct pack_idx_header *hdr;
750 size_t idx_size;
751 uint32_t version, nr, i, *index;
752 int fd = git_open(path);
753 struct stat st;
755 if (fd < 0)
756 return -1;
757 if (fstat(fd, &st)) {
758 close(fd);
759 return -1;
761 idx_size = xsize_t(st.st_size);
762 if (idx_size < 4 * 256 + 20 + 20) {
763 close(fd);
764 return error("index file %s is too small", path);
766 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
767 close(fd);
769 hdr = idx_map;
770 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
771 version = ntohl(hdr->idx_version);
772 if (version < 2 || version > 2) {
773 munmap(idx_map, idx_size);
774 return error("index file %s is version %"PRIu32
775 " and is not supported by this binary"
776 " (try upgrading GIT to a newer version)",
777 path, version);
779 } else
780 version = 1;
782 nr = 0;
783 index = idx_map;
784 if (version > 1)
785 index += 2; /* skip index header */
786 for (i = 0; i < 256; i++) {
787 uint32_t n = ntohl(index[i]);
788 if (n < nr) {
789 munmap(idx_map, idx_size);
790 return error("non-monotonic index %s", path);
792 nr = n;
795 if (version == 1) {
797 * Total size:
798 * - 256 index entries 4 bytes each
799 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
800 * - 20-byte SHA1 of the packfile
801 * - 20-byte SHA1 file checksum
803 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
804 munmap(idx_map, idx_size);
805 return error("wrong index v1 file size in %s", path);
807 } else if (version == 2) {
809 * Minimum size:
810 * - 8 bytes of header
811 * - 256 index entries 4 bytes each
812 * - 20-byte sha1 entry * nr
813 * - 4-byte crc entry * nr
814 * - 4-byte offset entry * nr
815 * - 20-byte SHA1 of the packfile
816 * - 20-byte SHA1 file checksum
817 * And after the 4-byte offset table might be a
818 * variable sized table containing 8-byte entries
819 * for offsets larger than 2^31.
821 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
822 unsigned long max_size = min_size;
823 if (nr)
824 max_size += (nr - 1)*8;
825 if (idx_size < min_size || idx_size > max_size) {
826 munmap(idx_map, idx_size);
827 return error("wrong index v2 file size in %s", path);
829 if (idx_size != min_size &&
831 * make sure we can deal with large pack offsets.
832 * 31-bit signed offset won't be enough, neither
833 * 32-bit unsigned one will be.
835 (sizeof(off_t) <= 4)) {
836 munmap(idx_map, idx_size);
837 return error("pack too large for current definition of off_t in %s", path);
841 p->index_version = version;
842 p->index_data = idx_map;
843 p->index_size = idx_size;
844 p->num_objects = nr;
845 return 0;
848 int open_pack_index(struct packed_git *p)
850 char *idx_name;
851 size_t len;
852 int ret;
854 if (p->index_data)
855 return 0;
857 if (!strip_suffix(p->pack_name, ".pack", &len))
858 die("BUG: pack_name does not end in .pack");
859 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
860 ret = check_packed_git_idx(idx_name, p);
861 free(idx_name);
862 return ret;
865 static void scan_windows(struct packed_git *p,
866 struct packed_git **lru_p,
867 struct pack_window **lru_w,
868 struct pack_window **lru_l)
870 struct pack_window *w, *w_l;
872 for (w_l = NULL, w = p->windows; w; w = w->next) {
873 if (!w->inuse_cnt) {
874 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
875 *lru_p = p;
876 *lru_w = w;
877 *lru_l = w_l;
880 w_l = w;
884 static int unuse_one_window(struct packed_git *current)
886 struct packed_git *p, *lru_p = NULL;
887 struct pack_window *lru_w = NULL, *lru_l = NULL;
889 if (current)
890 scan_windows(current, &lru_p, &lru_w, &lru_l);
891 for (p = packed_git; p; p = p->next)
892 scan_windows(p, &lru_p, &lru_w, &lru_l);
893 if (lru_p) {
894 munmap(lru_w->base, lru_w->len);
895 pack_mapped -= lru_w->len;
896 if (lru_l)
897 lru_l->next = lru_w->next;
898 else
899 lru_p->windows = lru_w->next;
900 free(lru_w);
901 pack_open_windows--;
902 return 1;
904 return 0;
907 void release_pack_memory(size_t need)
909 size_t cur = pack_mapped;
910 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
911 ; /* nothing */
914 static void mmap_limit_check(size_t length)
916 static size_t limit = 0;
917 if (!limit) {
918 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
919 if (!limit)
920 limit = SIZE_MAX;
922 if (length > limit)
923 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
924 (uintmax_t)length, (uintmax_t)limit);
927 void *xmmap_gently(void *start, size_t length,
928 int prot, int flags, int fd, off_t offset)
930 void *ret;
932 mmap_limit_check(length);
933 ret = mmap(start, length, prot, flags, fd, offset);
934 if (ret == MAP_FAILED) {
935 if (!length)
936 return NULL;
937 release_pack_memory(length);
938 ret = mmap(start, length, prot, flags, fd, offset);
940 return ret;
943 void *xmmap(void *start, size_t length,
944 int prot, int flags, int fd, off_t offset)
946 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
947 if (ret == MAP_FAILED)
948 die_errno("mmap failed");
949 return ret;
952 void close_pack_windows(struct packed_git *p)
954 while (p->windows) {
955 struct pack_window *w = p->windows;
957 if (w->inuse_cnt)
958 die("pack '%s' still has open windows to it",
959 p->pack_name);
960 munmap(w->base, w->len);
961 pack_mapped -= w->len;
962 pack_open_windows--;
963 p->windows = w->next;
964 free(w);
968 static int close_pack_fd(struct packed_git *p)
970 if (p->pack_fd < 0)
971 return 0;
973 close(p->pack_fd);
974 pack_open_fds--;
975 p->pack_fd = -1;
977 return 1;
980 static void close_pack(struct packed_git *p)
982 close_pack_windows(p);
983 close_pack_fd(p);
984 close_pack_index(p);
987 void close_all_packs(void)
989 struct packed_git *p;
991 for (p = packed_git; p; p = p->next)
992 if (p->do_not_close)
993 die("BUG: want to close pack marked 'do-not-close'");
994 else
995 close_pack(p);
1000 * The LRU pack is the one with the oldest MRU window, preferring packs
1001 * with no used windows, or the oldest mtime if it has no windows allocated.
1003 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
1005 struct pack_window *w, *this_mru_w;
1006 int has_windows_inuse = 0;
1009 * Reject this pack if it has windows and the previously selected
1010 * one does not. If this pack does not have windows, reject
1011 * it if the pack file is newer than the previously selected one.
1013 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
1014 return;
1016 for (w = this_mru_w = p->windows; w; w = w->next) {
1018 * Reject this pack if any of its windows are in use,
1019 * but the previously selected pack did not have any
1020 * inuse windows. Otherwise, record that this pack
1021 * has windows in use.
1023 if (w->inuse_cnt) {
1024 if (*accept_windows_inuse)
1025 has_windows_inuse = 1;
1026 else
1027 return;
1030 if (w->last_used > this_mru_w->last_used)
1031 this_mru_w = w;
1034 * Reject this pack if it has windows that have been
1035 * used more recently than the previously selected pack.
1036 * If the previously selected pack had windows inuse and
1037 * we have not encountered a window in this pack that is
1038 * inuse, skip this check since we prefer a pack with no
1039 * inuse windows to one that has inuse windows.
1041 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
1042 this_mru_w->last_used > (*mru_w)->last_used)
1043 return;
1047 * Select this pack.
1049 *mru_w = this_mru_w;
1050 *lru_p = p;
1051 *accept_windows_inuse = has_windows_inuse;
1054 static int close_one_pack(void)
1056 struct packed_git *p, *lru_p = NULL;
1057 struct pack_window *mru_w = NULL;
1058 int accept_windows_inuse = 1;
1060 for (p = packed_git; p; p = p->next) {
1061 if (p->pack_fd == -1)
1062 continue;
1063 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
1066 if (lru_p)
1067 return close_pack_fd(lru_p);
1069 return 0;
1072 void unuse_pack(struct pack_window **w_cursor)
1074 struct pack_window *w = *w_cursor;
1075 if (w) {
1076 w->inuse_cnt--;
1077 *w_cursor = NULL;
1081 void close_pack_index(struct packed_git *p)
1083 if (p->index_data) {
1084 munmap((void *)p->index_data, p->index_size);
1085 p->index_data = NULL;
1089 static unsigned int get_max_fd_limit(void)
1091 #ifdef RLIMIT_NOFILE
1093 struct rlimit lim;
1095 if (!getrlimit(RLIMIT_NOFILE, &lim))
1096 return lim.rlim_cur;
1098 #endif
1100 #ifdef _SC_OPEN_MAX
1102 long open_max = sysconf(_SC_OPEN_MAX);
1103 if (0 < open_max)
1104 return open_max;
1106 * Otherwise, we got -1 for one of the two
1107 * reasons:
1109 * (1) sysconf() did not understand _SC_OPEN_MAX
1110 * and signaled an error with -1; or
1111 * (2) sysconf() said there is no limit.
1113 * We _could_ clear errno before calling sysconf() to
1114 * tell these two cases apart and return a huge number
1115 * in the latter case to let the caller cap it to a
1116 * value that is not so selfish, but letting the
1117 * fallback OPEN_MAX codepath take care of these cases
1118 * is a lot simpler.
1121 #endif
1123 #ifdef OPEN_MAX
1124 return OPEN_MAX;
1125 #else
1126 return 1; /* see the caller ;-) */
1127 #endif
1131 * Do not call this directly as this leaks p->pack_fd on error return;
1132 * call open_packed_git() instead.
1134 static int open_packed_git_1(struct packed_git *p)
1136 struct stat st;
1137 struct pack_header hdr;
1138 unsigned char sha1[20];
1139 unsigned char *idx_sha1;
1140 long fd_flag;
1142 if (!p->index_data && open_pack_index(p))
1143 return error("packfile %s index unavailable", p->pack_name);
1145 if (!pack_max_fds) {
1146 unsigned int max_fds = get_max_fd_limit();
1148 /* Save 3 for stdin/stdout/stderr, 22 for work */
1149 if (25 < max_fds)
1150 pack_max_fds = max_fds - 25;
1151 else
1152 pack_max_fds = 1;
1155 while (pack_max_fds <= pack_open_fds && close_one_pack())
1156 ; /* nothing */
1158 p->pack_fd = git_open(p->pack_name);
1159 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
1160 return -1;
1161 pack_open_fds++;
1163 /* If we created the struct before we had the pack we lack size. */
1164 if (!p->pack_size) {
1165 if (!S_ISREG(st.st_mode))
1166 return error("packfile %s not a regular file", p->pack_name);
1167 p->pack_size = st.st_size;
1168 } else if (p->pack_size != st.st_size)
1169 return error("packfile %s size changed", p->pack_name);
1171 /* We leave these file descriptors open with sliding mmap;
1172 * there is no point keeping them open across exec(), though.
1174 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
1175 if (fd_flag < 0)
1176 return error("cannot determine file descriptor flags");
1177 fd_flag |= FD_CLOEXEC;
1178 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
1179 return error("cannot set FD_CLOEXEC");
1181 /* Verify we recognize this pack file format. */
1182 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
1183 return error("file %s is far too short to be a packfile", p->pack_name);
1184 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
1185 return error("file %s is not a GIT packfile", p->pack_name);
1186 if (!pack_version_ok(hdr.hdr_version))
1187 return error("packfile %s is version %"PRIu32" and not"
1188 " supported (try upgrading GIT to a newer version)",
1189 p->pack_name, ntohl(hdr.hdr_version));
1191 /* Verify the pack matches its index. */
1192 if (p->num_objects != ntohl(hdr.hdr_entries))
1193 return error("packfile %s claims to have %"PRIu32" objects"
1194 " while index indicates %"PRIu32" objects",
1195 p->pack_name, ntohl(hdr.hdr_entries),
1196 p->num_objects);
1197 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
1198 return error("end of packfile %s is unavailable", p->pack_name);
1199 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
1200 return error("packfile %s signature is unavailable", p->pack_name);
1201 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
1202 if (hashcmp(sha1, idx_sha1))
1203 return error("packfile %s does not match index", p->pack_name);
1204 return 0;
1207 static int open_packed_git(struct packed_git *p)
1209 if (!open_packed_git_1(p))
1210 return 0;
1211 close_pack_fd(p);
1212 return -1;
1215 static int in_window(struct pack_window *win, off_t offset)
1217 /* We must promise at least 20 bytes (one hash) after the
1218 * offset is available from this window, otherwise the offset
1219 * is not actually in this window and a different window (which
1220 * has that one hash excess) must be used. This is to support
1221 * the object header and delta base parsing routines below.
1223 off_t win_off = win->offset;
1224 return win_off <= offset
1225 && (offset + 20) <= (win_off + win->len);
1228 unsigned char *use_pack(struct packed_git *p,
1229 struct pack_window **w_cursor,
1230 off_t offset,
1231 unsigned long *left)
1233 struct pack_window *win = *w_cursor;
1235 /* Since packfiles end in a hash of their content and it's
1236 * pointless to ask for an offset into the middle of that
1237 * hash, and the in_window function above wouldn't match
1238 * don't allow an offset too close to the end of the file.
1240 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1241 die("packfile %s cannot be accessed", p->pack_name);
1242 if (offset > (p->pack_size - 20))
1243 die("offset beyond end of packfile (truncated pack?)");
1244 if (offset < 0)
1245 die(_("offset before end of packfile (broken .idx?)"));
1247 if (!win || !in_window(win, offset)) {
1248 if (win)
1249 win->inuse_cnt--;
1250 for (win = p->windows; win; win = win->next) {
1251 if (in_window(win, offset))
1252 break;
1254 if (!win) {
1255 size_t window_align = packed_git_window_size / 2;
1256 off_t len;
1258 if (p->pack_fd == -1 && open_packed_git(p))
1259 die("packfile %s cannot be accessed", p->pack_name);
1261 win = xcalloc(1, sizeof(*win));
1262 win->offset = (offset / window_align) * window_align;
1263 len = p->pack_size - win->offset;
1264 if (len > packed_git_window_size)
1265 len = packed_git_window_size;
1266 win->len = (size_t)len;
1267 pack_mapped += win->len;
1268 while (packed_git_limit < pack_mapped
1269 && unuse_one_window(p))
1270 ; /* nothing */
1271 win->base = xmmap(NULL, win->len,
1272 PROT_READ, MAP_PRIVATE,
1273 p->pack_fd, win->offset);
1274 if (win->base == MAP_FAILED)
1275 die_errno("packfile %s cannot be mapped",
1276 p->pack_name);
1277 if (!win->offset && win->len == p->pack_size
1278 && !p->do_not_close)
1279 close_pack_fd(p);
1280 pack_mmap_calls++;
1281 pack_open_windows++;
1282 if (pack_mapped > peak_pack_mapped)
1283 peak_pack_mapped = pack_mapped;
1284 if (pack_open_windows > peak_pack_open_windows)
1285 peak_pack_open_windows = pack_open_windows;
1286 win->next = p->windows;
1287 p->windows = win;
1290 if (win != *w_cursor) {
1291 win->last_used = pack_used_ctr++;
1292 win->inuse_cnt++;
1293 *w_cursor = win;
1295 offset -= win->offset;
1296 if (left)
1297 *left = win->len - xsize_t(offset);
1298 return win->base + offset;
1301 static struct packed_git *alloc_packed_git(int extra)
1303 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
1304 memset(p, 0, sizeof(*p));
1305 p->pack_fd = -1;
1306 return p;
1309 static void try_to_free_pack_memory(size_t size)
1311 release_pack_memory(size);
1314 struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1316 static int have_set_try_to_free_routine;
1317 struct stat st;
1318 size_t alloc;
1319 struct packed_git *p;
1321 if (!have_set_try_to_free_routine) {
1322 have_set_try_to_free_routine = 1;
1323 set_try_to_free_routine(try_to_free_pack_memory);
1327 * Make sure a corresponding .pack file exists and that
1328 * the index looks sane.
1330 if (!strip_suffix_mem(path, &path_len, ".idx"))
1331 return NULL;
1334 * ".pack" is long enough to hold any suffix we're adding (and
1335 * the use xsnprintf double-checks that)
1337 alloc = st_add3(path_len, strlen(".pack"), 1);
1338 p = alloc_packed_git(alloc);
1339 memcpy(p->pack_name, path, path_len);
1341 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
1342 if (!access(p->pack_name, F_OK))
1343 p->pack_keep = 1;
1345 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
1346 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
1347 free(p);
1348 return NULL;
1351 /* ok, it looks sane as far as we can check without
1352 * actually mapping the pack file.
1354 p->pack_size = st.st_size;
1355 p->pack_local = local;
1356 p->mtime = st.st_mtime;
1357 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1358 hashclr(p->sha1);
1359 return p;
1362 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
1364 const char *path = sha1_pack_name(sha1);
1365 size_t alloc = st_add(strlen(path), 1);
1366 struct packed_git *p = alloc_packed_git(alloc);
1368 memcpy(p->pack_name, path, alloc); /* includes NUL */
1369 hashcpy(p->sha1, sha1);
1370 if (check_packed_git_idx(idx_path, p)) {
1371 free(p);
1372 return NULL;
1375 return p;
1378 void install_packed_git(struct packed_git *pack)
1380 if (pack->pack_fd != -1)
1381 pack_open_fds++;
1383 pack->next = packed_git;
1384 packed_git = pack;
1387 void (*report_garbage)(unsigned seen_bits, const char *path);
1389 static void report_helper(const struct string_list *list,
1390 int seen_bits, int first, int last)
1392 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
1393 return;
1395 for (; first < last; first++)
1396 report_garbage(seen_bits, list->items[first].string);
1399 static void report_pack_garbage(struct string_list *list)
1401 int i, baselen = -1, first = 0, seen_bits = 0;
1403 if (!report_garbage)
1404 return;
1406 string_list_sort(list);
1408 for (i = 0; i < list->nr; i++) {
1409 const char *path = list->items[i].string;
1410 if (baselen != -1 &&
1411 strncmp(path, list->items[first].string, baselen)) {
1412 report_helper(list, seen_bits, first, i);
1413 baselen = -1;
1414 seen_bits = 0;
1416 if (baselen == -1) {
1417 const char *dot = strrchr(path, '.');
1418 if (!dot) {
1419 report_garbage(PACKDIR_FILE_GARBAGE, path);
1420 continue;
1422 baselen = dot - path + 1;
1423 first = i;
1425 if (!strcmp(path + baselen, "pack"))
1426 seen_bits |= 1;
1427 else if (!strcmp(path + baselen, "idx"))
1428 seen_bits |= 2;
1430 report_helper(list, seen_bits, first, list->nr);
1433 static void prepare_packed_git_one(char *objdir, int local)
1435 struct strbuf path = STRBUF_INIT;
1436 size_t dirnamelen;
1437 DIR *dir;
1438 struct dirent *de;
1439 struct string_list garbage = STRING_LIST_INIT_DUP;
1441 strbuf_addstr(&path, objdir);
1442 strbuf_addstr(&path, "/pack");
1443 dir = opendir(path.buf);
1444 if (!dir) {
1445 if (errno != ENOENT)
1446 error_errno("unable to open object pack directory: %s",
1447 path.buf);
1448 strbuf_release(&path);
1449 return;
1451 strbuf_addch(&path, '/');
1452 dirnamelen = path.len;
1453 while ((de = readdir(dir)) != NULL) {
1454 struct packed_git *p;
1455 size_t base_len;
1457 if (is_dot_or_dotdot(de->d_name))
1458 continue;
1460 strbuf_setlen(&path, dirnamelen);
1461 strbuf_addstr(&path, de->d_name);
1463 base_len = path.len;
1464 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
1465 /* Don't reopen a pack we already have. */
1466 for (p = packed_git; p; p = p->next) {
1467 size_t len;
1468 if (strip_suffix(p->pack_name, ".pack", &len) &&
1469 len == base_len &&
1470 !memcmp(p->pack_name, path.buf, len))
1471 break;
1473 if (p == NULL &&
1475 * See if it really is a valid .idx file with
1476 * corresponding .pack file that we can map.
1478 (p = add_packed_git(path.buf, path.len, local)) != NULL)
1479 install_packed_git(p);
1482 if (!report_garbage)
1483 continue;
1485 if (ends_with(de->d_name, ".idx") ||
1486 ends_with(de->d_name, ".pack") ||
1487 ends_with(de->d_name, ".bitmap") ||
1488 ends_with(de->d_name, ".keep"))
1489 string_list_append(&garbage, path.buf);
1490 else
1491 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1493 closedir(dir);
1494 report_pack_garbage(&garbage);
1495 string_list_clear(&garbage, 0);
1496 strbuf_release(&path);
1499 static int approximate_object_count_valid;
1502 * Give a fast, rough count of the number of objects in the repository. This
1503 * ignores loose objects completely. If you have a lot of them, then either
1504 * you should repack because your performance will be awful, or they are
1505 * all unreachable objects about to be pruned, in which case they're not really
1506 * interesting as a measure of repo size in the first place.
1508 unsigned long approximate_object_count(void)
1510 static unsigned long count;
1511 if (!approximate_object_count_valid) {
1512 struct packed_git *p;
1514 prepare_packed_git();
1515 count = 0;
1516 for (p = packed_git; p; p = p->next) {
1517 if (open_pack_index(p))
1518 continue;
1519 count += p->num_objects;
1522 return count;
1525 static void *get_next_packed_git(const void *p)
1527 return ((const struct packed_git *)p)->next;
1530 static void set_next_packed_git(void *p, void *next)
1532 ((struct packed_git *)p)->next = next;
1535 static int sort_pack(const void *a_, const void *b_)
1537 const struct packed_git *a = a_;
1538 const struct packed_git *b = b_;
1539 int st;
1542 * Local packs tend to contain objects specific to our
1543 * variant of the project than remote ones. In addition,
1544 * remote ones could be on a network mounted filesystem.
1545 * Favor local ones for these reasons.
1547 st = a->pack_local - b->pack_local;
1548 if (st)
1549 return -st;
1552 * Younger packs tend to contain more recent objects,
1553 * and more recent objects tend to get accessed more
1554 * often.
1556 if (a->mtime < b->mtime)
1557 return 1;
1558 else if (a->mtime == b->mtime)
1559 return 0;
1560 return -1;
1563 static void rearrange_packed_git(void)
1565 packed_git = llist_mergesort(packed_git, get_next_packed_git,
1566 set_next_packed_git, sort_pack);
1569 static void prepare_packed_git_mru(void)
1571 struct packed_git *p;
1573 mru_clear(packed_git_mru);
1574 for (p = packed_git; p; p = p->next)
1575 mru_append(packed_git_mru, p);
1578 static int prepare_packed_git_run_once = 0;
1579 void prepare_packed_git(void)
1581 struct alternate_object_database *alt;
1583 if (prepare_packed_git_run_once)
1584 return;
1585 prepare_packed_git_one(get_object_directory(), 1);
1586 prepare_alt_odb();
1587 for (alt = alt_odb_list; alt; alt = alt->next)
1588 prepare_packed_git_one(alt->path, 0);
1589 rearrange_packed_git();
1590 prepare_packed_git_mru();
1591 prepare_packed_git_run_once = 1;
1594 void reprepare_packed_git(void)
1596 approximate_object_count_valid = 0;
1597 prepare_packed_git_run_once = 0;
1598 prepare_packed_git();
1601 static void mark_bad_packed_object(struct packed_git *p,
1602 const unsigned char *sha1)
1604 unsigned i;
1605 for (i = 0; i < p->num_bad_objects; i++)
1606 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
1607 return;
1608 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1609 st_mult(GIT_MAX_RAWSZ,
1610 st_add(p->num_bad_objects, 1)));
1611 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
1612 p->num_bad_objects++;
1615 static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1617 struct packed_git *p;
1618 unsigned i;
1620 for (p = packed_git; p; p = p->next)
1621 for (i = 0; i < p->num_bad_objects; i++)
1622 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1623 return p;
1624 return NULL;
1628 * With an in-core object data in "map", rehash it to make sure the
1629 * object name actually matches "sha1" to detect object corruption.
1630 * With "map" == NULL, try reading the object named with "sha1" using
1631 * the streaming interface and rehash it to do the same.
1633 int check_sha1_signature(const unsigned char *sha1, void *map,
1634 unsigned long size, const char *type)
1636 unsigned char real_sha1[20];
1637 enum object_type obj_type;
1638 struct git_istream *st;
1639 git_SHA_CTX c;
1640 char hdr[32];
1641 int hdrlen;
1643 if (map) {
1644 hash_sha1_file(map, size, type, real_sha1);
1645 return hashcmp(sha1, real_sha1) ? -1 : 0;
1648 st = open_istream(sha1, &obj_type, &size, NULL);
1649 if (!st)
1650 return -1;
1652 /* Generate the header */
1653 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
1655 /* Sha1.. */
1656 git_SHA1_Init(&c);
1657 git_SHA1_Update(&c, hdr, hdrlen);
1658 for (;;) {
1659 char buf[1024 * 16];
1660 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1662 if (readlen < 0) {
1663 close_istream(st);
1664 return -1;
1666 if (!readlen)
1667 break;
1668 git_SHA1_Update(&c, buf, readlen);
1670 git_SHA1_Final(real_sha1, &c);
1671 close_istream(st);
1672 return hashcmp(sha1, real_sha1) ? -1 : 0;
1675 int git_open_cloexec(const char *name, int flags)
1677 int fd;
1678 static int o_cloexec = O_CLOEXEC;
1680 fd = open(name, flags | o_cloexec);
1681 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
1682 /* Try again w/o O_CLOEXEC: the kernel might not support it */
1683 o_cloexec &= ~O_CLOEXEC;
1684 fd = open(name, flags | o_cloexec);
1687 #if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
1689 static int fd_cloexec = FD_CLOEXEC;
1691 if (!o_cloexec && 0 <= fd && fd_cloexec) {
1692 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
1693 int flags = fcntl(fd, F_GETFD);
1694 if (fcntl(fd, F_SETFD, flags | fd_cloexec))
1695 fd_cloexec = 0;
1698 #endif
1699 return fd;
1703 * Find "sha1" as a loose object in the local repository or in an alternate.
1704 * Returns 0 on success, negative on failure.
1706 * The "path" out-parameter will give the path of the object we found (if any).
1707 * Note that it may point to static storage and is only valid until another
1708 * call to sha1_file_name(), etc.
1710 static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
1711 const char **path)
1713 struct alternate_object_database *alt;
1715 *path = sha1_file_name(sha1);
1716 if (!lstat(*path, st))
1717 return 0;
1719 prepare_alt_odb();
1720 errno = ENOENT;
1721 for (alt = alt_odb_list; alt; alt = alt->next) {
1722 *path = alt_sha1_path(alt, sha1);
1723 if (!lstat(*path, st))
1724 return 0;
1727 return -1;
1731 * Like stat_sha1_file(), but actually open the object and return the
1732 * descriptor. See the caveats on the "path" parameter above.
1734 static int open_sha1_file(const unsigned char *sha1, const char **path)
1736 int fd;
1737 struct alternate_object_database *alt;
1738 int most_interesting_errno;
1740 *path = sha1_file_name(sha1);
1741 fd = git_open(*path);
1742 if (fd >= 0)
1743 return fd;
1744 most_interesting_errno = errno;
1746 prepare_alt_odb();
1747 for (alt = alt_odb_list; alt; alt = alt->next) {
1748 *path = alt_sha1_path(alt, sha1);
1749 fd = git_open(*path);
1750 if (fd >= 0)
1751 return fd;
1752 if (most_interesting_errno == ENOENT)
1753 most_interesting_errno = errno;
1755 errno = most_interesting_errno;
1756 return -1;
1760 * Map the loose object at "path" if it is not NULL, or the path found by
1761 * searching for a loose object named "sha1".
1763 static void *map_sha1_file_1(const char *path,
1764 const unsigned char *sha1,
1765 unsigned long *size)
1767 void *map;
1768 int fd;
1770 if (path)
1771 fd = git_open(path);
1772 else
1773 fd = open_sha1_file(sha1, &path);
1774 map = NULL;
1775 if (fd >= 0) {
1776 struct stat st;
1778 if (!fstat(fd, &st)) {
1779 *size = xsize_t(st.st_size);
1780 if (!*size) {
1781 /* mmap() is forbidden on empty files */
1782 error("object file %s is empty", path);
1783 return NULL;
1785 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1787 close(fd);
1789 return map;
1792 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1794 return map_sha1_file_1(NULL, sha1, size);
1797 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1798 unsigned long len, enum object_type *type, unsigned long *sizep)
1800 unsigned shift;
1801 unsigned long size, c;
1802 unsigned long used = 0;
1804 c = buf[used++];
1805 *type = (c >> 4) & 7;
1806 size = c & 15;
1807 shift = 4;
1808 while (c & 0x80) {
1809 if (len <= used || bitsizeof(long) <= shift) {
1810 error("bad object header");
1811 size = used = 0;
1812 break;
1814 c = buf[used++];
1815 size += (c & 0x7f) << shift;
1816 shift += 7;
1818 *sizep = size;
1819 return used;
1822 static int unpack_sha1_short_header(git_zstream *stream,
1823 unsigned char *map, unsigned long mapsize,
1824 void *buffer, unsigned long bufsiz)
1826 /* Get the data stream */
1827 memset(stream, 0, sizeof(*stream));
1828 stream->next_in = map;
1829 stream->avail_in = mapsize;
1830 stream->next_out = buffer;
1831 stream->avail_out = bufsiz;
1833 git_inflate_init(stream);
1834 return git_inflate(stream, 0);
1837 int unpack_sha1_header(git_zstream *stream,
1838 unsigned char *map, unsigned long mapsize,
1839 void *buffer, unsigned long bufsiz)
1841 int status = unpack_sha1_short_header(stream, map, mapsize,
1842 buffer, bufsiz);
1844 if (status < Z_OK)
1845 return status;
1847 /* Make sure we have the terminating NUL */
1848 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1849 return -1;
1850 return 0;
1853 static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1854 unsigned long mapsize, void *buffer,
1855 unsigned long bufsiz, struct strbuf *header)
1857 int status;
1859 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
1860 if (status < Z_OK)
1861 return -1;
1864 * Check if entire header is unpacked in the first iteration.
1866 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1867 return 0;
1870 * buffer[0..bufsiz] was not large enough. Copy the partial
1871 * result out to header, and then append the result of further
1872 * reading the stream.
1874 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1875 stream->next_out = buffer;
1876 stream->avail_out = bufsiz;
1878 do {
1879 status = git_inflate(stream, 0);
1880 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1881 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1882 return 0;
1883 stream->next_out = buffer;
1884 stream->avail_out = bufsiz;
1885 } while (status != Z_STREAM_END);
1886 return -1;
1889 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1891 int bytes = strlen(buffer) + 1;
1892 unsigned char *buf = xmallocz(size);
1893 unsigned long n;
1894 int status = Z_OK;
1896 n = stream->total_out - bytes;
1897 if (n > size)
1898 n = size;
1899 memcpy(buf, (char *) buffer + bytes, n);
1900 bytes = n;
1901 if (bytes <= size) {
1903 * The above condition must be (bytes <= size), not
1904 * (bytes < size). In other words, even though we
1905 * expect no more output and set avail_out to zero,
1906 * the input zlib stream may have bytes that express
1907 * "this concludes the stream", and we *do* want to
1908 * eat that input.
1910 * Otherwise we would not be able to test that we
1911 * consumed all the input to reach the expected size;
1912 * we also want to check that zlib tells us that all
1913 * went well with status == Z_STREAM_END at the end.
1915 stream->next_out = buf + bytes;
1916 stream->avail_out = size - bytes;
1917 while (status == Z_OK)
1918 status = git_inflate(stream, Z_FINISH);
1920 if (status == Z_STREAM_END && !stream->avail_in) {
1921 git_inflate_end(stream);
1922 return buf;
1925 if (status < 0)
1926 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1927 else if (stream->avail_in)
1928 error("garbage at end of loose object '%s'",
1929 sha1_to_hex(sha1));
1930 free(buf);
1931 return NULL;
1935 * We used to just use "sscanf()", but that's actually way
1936 * too permissive for what we want to check. So do an anal
1937 * object header parse by hand.
1939 static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1940 unsigned int flags)
1942 const char *type_buf = hdr;
1943 unsigned long size;
1944 int type, type_len = 0;
1947 * The type can be of any size but is followed by
1948 * a space.
1950 for (;;) {
1951 char c = *hdr++;
1952 if (!c)
1953 return -1;
1954 if (c == ' ')
1955 break;
1956 type_len++;
1959 type = type_from_string_gently(type_buf, type_len, 1);
1960 if (oi->typename)
1961 strbuf_add(oi->typename, type_buf, type_len);
1963 * Set type to 0 if its an unknown object and
1964 * we're obtaining the type using '--allow-unknown-type'
1965 * option.
1967 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
1968 type = 0;
1969 else if (type < 0)
1970 die("invalid object type");
1971 if (oi->typep)
1972 *oi->typep = type;
1975 * The length must follow immediately, and be in canonical
1976 * decimal format (ie "010" is not valid).
1978 size = *hdr++ - '0';
1979 if (size > 9)
1980 return -1;
1981 if (size) {
1982 for (;;) {
1983 unsigned long c = *hdr - '0';
1984 if (c > 9)
1985 break;
1986 hdr++;
1987 size = size * 10 + c;
1991 if (oi->sizep)
1992 *oi->sizep = size;
1995 * The length must be followed by a zero byte
1997 return *hdr ? -1 : type;
2000 int parse_sha1_header(const char *hdr, unsigned long *sizep)
2002 struct object_info oi = OBJECT_INFO_INIT;
2004 oi.sizep = sizep;
2005 return parse_sha1_header_extended(hdr, &oi, 0);
2008 unsigned long get_size_from_delta(struct packed_git *p,
2009 struct pack_window **w_curs,
2010 off_t curpos)
2012 const unsigned char *data;
2013 unsigned char delta_head[20], *in;
2014 git_zstream stream;
2015 int st;
2017 memset(&stream, 0, sizeof(stream));
2018 stream.next_out = delta_head;
2019 stream.avail_out = sizeof(delta_head);
2021 git_inflate_init(&stream);
2022 do {
2023 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2024 stream.next_in = in;
2025 st = git_inflate(&stream, Z_FINISH);
2026 curpos += stream.next_in - in;
2027 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
2028 stream.total_out < sizeof(delta_head));
2029 git_inflate_end(&stream);
2030 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
2031 error("delta data unpack-initial failed");
2032 return 0;
2035 /* Examine the initial part of the delta to figure out
2036 * the result size.
2038 data = delta_head;
2040 /* ignore base size */
2041 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2043 /* Read the result size */
2044 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2047 static off_t get_delta_base(struct packed_git *p,
2048 struct pack_window **w_curs,
2049 off_t *curpos,
2050 enum object_type type,
2051 off_t delta_obj_offset)
2053 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
2054 off_t base_offset;
2056 /* use_pack() assured us we have [base_info, base_info + 20)
2057 * as a range that we can look at without walking off the
2058 * end of the mapped window. Its actually the hash size
2059 * that is assured. An OFS_DELTA longer than the hash size
2060 * is stupid, as then a REF_DELTA would be smaller to store.
2062 if (type == OBJ_OFS_DELTA) {
2063 unsigned used = 0;
2064 unsigned char c = base_info[used++];
2065 base_offset = c & 127;
2066 while (c & 128) {
2067 base_offset += 1;
2068 if (!base_offset || MSB(base_offset, 7))
2069 return 0; /* overflow */
2070 c = base_info[used++];
2071 base_offset = (base_offset << 7) + (c & 127);
2073 base_offset = delta_obj_offset - base_offset;
2074 if (base_offset <= 0 || base_offset >= delta_obj_offset)
2075 return 0; /* out of bound */
2076 *curpos += used;
2077 } else if (type == OBJ_REF_DELTA) {
2078 /* The base entry _must_ be in the same pack */
2079 base_offset = find_pack_entry_one(base_info, p);
2080 *curpos += 20;
2081 } else
2082 die("I am totally screwed");
2083 return base_offset;
2087 * Like get_delta_base above, but we return the sha1 instead of the pack
2088 * offset. This means it is cheaper for REF deltas (we do not have to do
2089 * the final object lookup), but more expensive for OFS deltas (we
2090 * have to load the revidx to convert the offset back into a sha1).
2092 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
2093 struct pack_window **w_curs,
2094 off_t curpos,
2095 enum object_type type,
2096 off_t delta_obj_offset)
2098 if (type == OBJ_REF_DELTA) {
2099 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
2100 return base;
2101 } else if (type == OBJ_OFS_DELTA) {
2102 struct revindex_entry *revidx;
2103 off_t base_offset = get_delta_base(p, w_curs, &curpos,
2104 type, delta_obj_offset);
2106 if (!base_offset)
2107 return NULL;
2109 revidx = find_pack_revindex(p, base_offset);
2110 if (!revidx)
2111 return NULL;
2113 return nth_packed_object_sha1(p, revidx->nr);
2114 } else
2115 return NULL;
2118 int unpack_object_header(struct packed_git *p,
2119 struct pack_window **w_curs,
2120 off_t *curpos,
2121 unsigned long *sizep)
2123 unsigned char *base;
2124 unsigned long left;
2125 unsigned long used;
2126 enum object_type type;
2128 /* use_pack() assures us we have [base, base + 20) available
2129 * as a range that we can look at. (Its actually the hash
2130 * size that is assured.) With our object header encoding
2131 * the maximum deflated object size is 2^137, which is just
2132 * insane, so we know won't exceed what we have been given.
2134 base = use_pack(p, w_curs, *curpos, &left);
2135 used = unpack_object_header_buffer(base, left, &type, sizep);
2136 if (!used) {
2137 type = OBJ_BAD;
2138 } else
2139 *curpos += used;
2141 return type;
2144 static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
2146 int type;
2147 struct revindex_entry *revidx;
2148 const unsigned char *sha1;
2149 revidx = find_pack_revindex(p, obj_offset);
2150 if (!revidx)
2151 return OBJ_BAD;
2152 sha1 = nth_packed_object_sha1(p, revidx->nr);
2153 mark_bad_packed_object(p, sha1);
2154 type = sha1_object_info(sha1, NULL);
2155 if (type <= OBJ_NONE)
2156 return OBJ_BAD;
2157 return type;
2160 #define POI_STACK_PREALLOC 64
2162 static enum object_type packed_to_object_type(struct packed_git *p,
2163 off_t obj_offset,
2164 enum object_type type,
2165 struct pack_window **w_curs,
2166 off_t curpos)
2168 off_t small_poi_stack[POI_STACK_PREALLOC];
2169 off_t *poi_stack = small_poi_stack;
2170 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
2172 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2173 off_t base_offset;
2174 unsigned long size;
2175 /* Push the object we're going to leave behind */
2176 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
2177 poi_stack_alloc = alloc_nr(poi_stack_nr);
2178 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
2179 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
2180 } else {
2181 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
2183 poi_stack[poi_stack_nr++] = obj_offset;
2184 /* If parsing the base offset fails, just unwind */
2185 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
2186 if (!base_offset)
2187 goto unwind;
2188 curpos = obj_offset = base_offset;
2189 type = unpack_object_header(p, w_curs, &curpos, &size);
2190 if (type <= OBJ_NONE) {
2191 /* If getting the base itself fails, we first
2192 * retry the base, otherwise unwind */
2193 type = retry_bad_packed_offset(p, base_offset);
2194 if (type > OBJ_NONE)
2195 goto out;
2196 goto unwind;
2200 switch (type) {
2201 case OBJ_BAD:
2202 case OBJ_COMMIT:
2203 case OBJ_TREE:
2204 case OBJ_BLOB:
2205 case OBJ_TAG:
2206 break;
2207 default:
2208 error("unknown object type %i at offset %"PRIuMAX" in %s",
2209 type, (uintmax_t)obj_offset, p->pack_name);
2210 type = OBJ_BAD;
2213 out:
2214 if (poi_stack != small_poi_stack)
2215 free(poi_stack);
2216 return type;
2218 unwind:
2219 while (poi_stack_nr) {
2220 obj_offset = poi_stack[--poi_stack_nr];
2221 type = retry_bad_packed_offset(p, obj_offset);
2222 if (type > OBJ_NONE)
2223 goto out;
2225 type = OBJ_BAD;
2226 goto out;
2229 static struct hashmap delta_base_cache;
2230 static size_t delta_base_cached;
2232 static LIST_HEAD(delta_base_cache_lru);
2234 struct delta_base_cache_key {
2235 struct packed_git *p;
2236 off_t base_offset;
2239 struct delta_base_cache_entry {
2240 struct hashmap hash;
2241 struct delta_base_cache_key key;
2242 struct list_head lru;
2243 void *data;
2244 unsigned long size;
2245 enum object_type type;
2248 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
2250 unsigned int hash;
2252 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
2253 hash += (hash >> 8) + (hash >> 16);
2254 return hash;
2257 static struct delta_base_cache_entry *
2258 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
2260 struct hashmap_entry entry;
2261 struct delta_base_cache_key key;
2263 if (!delta_base_cache.cmpfn)
2264 return NULL;
2266 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
2267 key.p = p;
2268 key.base_offset = base_offset;
2269 return hashmap_get(&delta_base_cache, &entry, &key);
2272 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
2273 const struct delta_base_cache_key *b)
2275 return a->p == b->p && a->base_offset == b->base_offset;
2278 static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
2279 const void *va, const void *vb,
2280 const void *vkey)
2282 const struct delta_base_cache_entry *a = va, *b = vb;
2283 const struct delta_base_cache_key *key = vkey;
2284 if (key)
2285 return !delta_base_cache_key_eq(&a->key, key);
2286 else
2287 return !delta_base_cache_key_eq(&a->key, &b->key);
2290 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2292 return !!get_delta_base_cache_entry(p, base_offset);
2296 * Remove the entry from the cache, but do _not_ free the associated
2297 * entry data. The caller takes ownership of the "data" buffer, and
2298 * should copy out any fields it wants before detaching.
2300 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2302 hashmap_remove(&delta_base_cache, ent, &ent->key);
2303 list_del(&ent->lru);
2304 delta_base_cached -= ent->size;
2305 free(ent);
2308 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
2309 unsigned long *base_size, enum object_type *type)
2311 struct delta_base_cache_entry *ent;
2313 ent = get_delta_base_cache_entry(p, base_offset);
2314 if (!ent)
2315 return unpack_entry(p, base_offset, type, base_size);
2317 if (type)
2318 *type = ent->type;
2319 if (base_size)
2320 *base_size = ent->size;
2321 return xmemdupz(ent->data, ent->size);
2324 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2326 free(ent->data);
2327 detach_delta_base_cache_entry(ent);
2330 void clear_delta_base_cache(void)
2332 struct list_head *lru, *tmp;
2333 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2334 struct delta_base_cache_entry *entry =
2335 list_entry(lru, struct delta_base_cache_entry, lru);
2336 release_delta_base_cache(entry);
2340 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2341 void *base, unsigned long base_size, enum object_type type)
2343 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
2344 struct list_head *lru, *tmp;
2346 delta_base_cached += base_size;
2348 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2349 struct delta_base_cache_entry *f =
2350 list_entry(lru, struct delta_base_cache_entry, lru);
2351 if (delta_base_cached <= delta_base_cache_limit)
2352 break;
2353 release_delta_base_cache(f);
2356 ent->key.p = p;
2357 ent->key.base_offset = base_offset;
2358 ent->type = type;
2359 ent->data = base;
2360 ent->size = base_size;
2361 list_add_tail(&ent->lru, &delta_base_cache_lru);
2363 if (!delta_base_cache.cmpfn)
2364 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
2365 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
2366 hashmap_add(&delta_base_cache, ent);
2369 int packed_object_info(struct packed_git *p, off_t obj_offset,
2370 struct object_info *oi)
2372 struct pack_window *w_curs = NULL;
2373 unsigned long size;
2374 off_t curpos = obj_offset;
2375 enum object_type type;
2378 * We always get the representation type, but only convert it to
2379 * a "real" type later if the caller is interested.
2381 if (oi->contentp) {
2382 *oi->contentp = cache_or_unpack_entry(p, obj_offset, oi->sizep,
2383 &type);
2384 if (!*oi->contentp)
2385 type = OBJ_BAD;
2386 } else {
2387 type = unpack_object_header(p, &w_curs, &curpos, &size);
2390 if (!oi->contentp && oi->sizep) {
2391 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2392 off_t tmp_pos = curpos;
2393 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2394 type, obj_offset);
2395 if (!base_offset) {
2396 type = OBJ_BAD;
2397 goto out;
2399 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2400 if (*oi->sizep == 0) {
2401 type = OBJ_BAD;
2402 goto out;
2404 } else {
2405 *oi->sizep = size;
2409 if (oi->disk_sizep) {
2410 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2411 *oi->disk_sizep = revidx[1].offset - obj_offset;
2414 if (oi->typep || oi->typename) {
2415 enum object_type ptot;
2416 ptot = packed_to_object_type(p, obj_offset, type, &w_curs,
2417 curpos);
2418 if (oi->typep)
2419 *oi->typep = ptot;
2420 if (oi->typename) {
2421 const char *tn = typename(ptot);
2422 if (tn)
2423 strbuf_addstr(oi->typename, tn);
2425 if (ptot < 0) {
2426 type = OBJ_BAD;
2427 goto out;
2431 if (oi->delta_base_sha1) {
2432 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2433 const unsigned char *base;
2435 base = get_delta_base_sha1(p, &w_curs, curpos,
2436 type, obj_offset);
2437 if (!base) {
2438 type = OBJ_BAD;
2439 goto out;
2442 hashcpy(oi->delta_base_sha1, base);
2443 } else
2444 hashclr(oi->delta_base_sha1);
2447 out:
2448 unuse_pack(&w_curs);
2449 return type;
2452 static void *unpack_compressed_entry(struct packed_git *p,
2453 struct pack_window **w_curs,
2454 off_t curpos,
2455 unsigned long size)
2457 int st;
2458 git_zstream stream;
2459 unsigned char *buffer, *in;
2461 buffer = xmallocz_gently(size);
2462 if (!buffer)
2463 return NULL;
2464 memset(&stream, 0, sizeof(stream));
2465 stream.next_out = buffer;
2466 stream.avail_out = size + 1;
2468 git_inflate_init(&stream);
2469 do {
2470 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2471 stream.next_in = in;
2472 st = git_inflate(&stream, Z_FINISH);
2473 if (!stream.avail_out)
2474 break; /* the payload is larger than it should be */
2475 curpos += stream.next_in - in;
2476 } while (st == Z_OK || st == Z_BUF_ERROR);
2477 git_inflate_end(&stream);
2478 if ((st != Z_STREAM_END) || stream.total_out != size) {
2479 free(buffer);
2480 return NULL;
2483 return buffer;
2486 static void *read_object(const unsigned char *sha1, enum object_type *type,
2487 unsigned long *size);
2489 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2491 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2492 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2493 p->pack_name, (uintmax_t)obj_offset);
2496 int do_check_packed_object_crc;
2498 #define UNPACK_ENTRY_STACK_PREALLOC 64
2499 struct unpack_entry_stack_ent {
2500 off_t obj_offset;
2501 off_t curpos;
2502 unsigned long size;
2505 void *unpack_entry(struct packed_git *p, off_t obj_offset,
2506 enum object_type *final_type, unsigned long *final_size)
2508 struct pack_window *w_curs = NULL;
2509 off_t curpos = obj_offset;
2510 void *data = NULL;
2511 unsigned long size;
2512 enum object_type type;
2513 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2514 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2515 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2516 int base_from_cache = 0;
2518 write_pack_access_log(p, obj_offset);
2520 /* PHASE 1: drill down to the innermost base object */
2521 for (;;) {
2522 off_t base_offset;
2523 int i;
2524 struct delta_base_cache_entry *ent;
2526 ent = get_delta_base_cache_entry(p, curpos);
2527 if (ent) {
2528 type = ent->type;
2529 data = ent->data;
2530 size = ent->size;
2531 detach_delta_base_cache_entry(ent);
2532 base_from_cache = 1;
2533 break;
2536 if (do_check_packed_object_crc && p->index_version > 1) {
2537 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2538 off_t len = revidx[1].offset - obj_offset;
2539 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2540 const unsigned char *sha1 =
2541 nth_packed_object_sha1(p, revidx->nr);
2542 error("bad packed object CRC for %s",
2543 sha1_to_hex(sha1));
2544 mark_bad_packed_object(p, sha1);
2545 unuse_pack(&w_curs);
2546 return NULL;
2550 type = unpack_object_header(p, &w_curs, &curpos, &size);
2551 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2552 break;
2554 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2555 if (!base_offset) {
2556 error("failed to validate delta base reference "
2557 "at offset %"PRIuMAX" from %s",
2558 (uintmax_t)curpos, p->pack_name);
2559 /* bail to phase 2, in hopes of recovery */
2560 data = NULL;
2561 break;
2564 /* push object, proceed to base */
2565 if (delta_stack_nr >= delta_stack_alloc
2566 && delta_stack == small_delta_stack) {
2567 delta_stack_alloc = alloc_nr(delta_stack_nr);
2568 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
2569 memcpy(delta_stack, small_delta_stack,
2570 sizeof(*delta_stack)*delta_stack_nr);
2571 } else {
2572 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2574 i = delta_stack_nr++;
2575 delta_stack[i].obj_offset = obj_offset;
2576 delta_stack[i].curpos = curpos;
2577 delta_stack[i].size = size;
2579 curpos = obj_offset = base_offset;
2582 /* PHASE 2: handle the base */
2583 switch (type) {
2584 case OBJ_OFS_DELTA:
2585 case OBJ_REF_DELTA:
2586 if (data)
2587 die("BUG: unpack_entry: left loop at a valid delta");
2588 break;
2589 case OBJ_COMMIT:
2590 case OBJ_TREE:
2591 case OBJ_BLOB:
2592 case OBJ_TAG:
2593 if (!base_from_cache)
2594 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2595 break;
2596 default:
2597 data = NULL;
2598 error("unknown object type %i at offset %"PRIuMAX" in %s",
2599 type, (uintmax_t)obj_offset, p->pack_name);
2602 /* PHASE 3: apply deltas in order */
2604 /* invariants:
2605 * 'data' holds the base data, or NULL if there was corruption
2607 while (delta_stack_nr) {
2608 void *delta_data;
2609 void *base = data;
2610 void *external_base = NULL;
2611 unsigned long delta_size, base_size = size;
2612 int i;
2614 data = NULL;
2616 if (base)
2617 add_delta_base_cache(p, obj_offset, base, base_size, type);
2619 if (!base) {
2621 * We're probably in deep shit, but let's try to fetch
2622 * the required base anyway from another pack or loose.
2623 * This is costly but should happen only in the presence
2624 * of a corrupted pack, and is better than failing outright.
2626 struct revindex_entry *revidx;
2627 const unsigned char *base_sha1;
2628 revidx = find_pack_revindex(p, obj_offset);
2629 if (revidx) {
2630 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2631 error("failed to read delta base object %s"
2632 " at offset %"PRIuMAX" from %s",
2633 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2634 p->pack_name);
2635 mark_bad_packed_object(p, base_sha1);
2636 base = read_object(base_sha1, &type, &base_size);
2637 external_base = base;
2641 i = --delta_stack_nr;
2642 obj_offset = delta_stack[i].obj_offset;
2643 curpos = delta_stack[i].curpos;
2644 delta_size = delta_stack[i].size;
2646 if (!base)
2647 continue;
2649 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2651 if (!delta_data) {
2652 error("failed to unpack compressed delta "
2653 "at offset %"PRIuMAX" from %s",
2654 (uintmax_t)curpos, p->pack_name);
2655 data = NULL;
2656 free(external_base);
2657 continue;
2660 data = patch_delta(base, base_size,
2661 delta_data, delta_size,
2662 &size);
2665 * We could not apply the delta; warn the user, but keep going.
2666 * Our failure will be noticed either in the next iteration of
2667 * the loop, or if this is the final delta, in the caller when
2668 * we return NULL. Those code paths will take care of making
2669 * a more explicit warning and retrying with another copy of
2670 * the object.
2672 if (!data)
2673 error("failed to apply delta");
2675 free(delta_data);
2676 free(external_base);
2679 if (final_type)
2680 *final_type = type;
2681 if (final_size)
2682 *final_size = size;
2684 unuse_pack(&w_curs);
2686 if (delta_stack != small_delta_stack)
2687 free(delta_stack);
2689 return data;
2692 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2693 uint32_t n)
2695 const unsigned char *index = p->index_data;
2696 if (!index) {
2697 if (open_pack_index(p))
2698 return NULL;
2699 index = p->index_data;
2701 if (n >= p->num_objects)
2702 return NULL;
2703 index += 4 * 256;
2704 if (p->index_version == 1) {
2705 return index + 24 * n + 4;
2706 } else {
2707 index += 8;
2708 return index + 20 * n;
2712 const struct object_id *nth_packed_object_oid(struct object_id *oid,
2713 struct packed_git *p,
2714 uint32_t n)
2716 const unsigned char *hash = nth_packed_object_sha1(p, n);
2717 if (!hash)
2718 return NULL;
2719 hashcpy(oid->hash, hash);
2720 return oid;
2723 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2725 const unsigned char *ptr = vptr;
2726 const unsigned char *start = p->index_data;
2727 const unsigned char *end = start + p->index_size;
2728 if (ptr < start)
2729 die(_("offset before start of pack index for %s (corrupt index?)"),
2730 p->pack_name);
2731 /* No need to check for underflow; .idx files must be at least 8 bytes */
2732 if (ptr >= end - 8)
2733 die(_("offset beyond end of pack index for %s (truncated index?)"),
2734 p->pack_name);
2737 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2739 const unsigned char *index = p->index_data;
2740 index += 4 * 256;
2741 if (p->index_version == 1) {
2742 return ntohl(*((uint32_t *)(index + 24 * n)));
2743 } else {
2744 uint32_t off;
2745 index += 8 + p->num_objects * (20 + 4);
2746 off = ntohl(*((uint32_t *)(index + 4 * n)));
2747 if (!(off & 0x80000000))
2748 return off;
2749 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2750 check_pack_index_ptr(p, index);
2751 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2752 ntohl(*((uint32_t *)(index + 4)));
2756 off_t find_pack_entry_one(const unsigned char *sha1,
2757 struct packed_git *p)
2759 const uint32_t *level1_ofs = p->index_data;
2760 const unsigned char *index = p->index_data;
2761 unsigned hi, lo, stride;
2762 static int use_lookup = -1;
2763 static int debug_lookup = -1;
2765 if (debug_lookup < 0)
2766 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2768 if (!index) {
2769 if (open_pack_index(p))
2770 return 0;
2771 level1_ofs = p->index_data;
2772 index = p->index_data;
2774 if (p->index_version > 1) {
2775 level1_ofs += 2;
2776 index += 8;
2778 index += 4 * 256;
2779 hi = ntohl(level1_ofs[*sha1]);
2780 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2781 if (p->index_version > 1) {
2782 stride = 20;
2783 } else {
2784 stride = 24;
2785 index += 4;
2788 if (debug_lookup)
2789 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2790 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2792 if (use_lookup < 0)
2793 use_lookup = !!getenv("GIT_USE_LOOKUP");
2794 if (use_lookup) {
2795 int pos = sha1_entry_pos(index, stride, 0,
2796 lo, hi, p->num_objects, sha1);
2797 if (pos < 0)
2798 return 0;
2799 return nth_packed_object_offset(p, pos);
2802 do {
2803 unsigned mi = (lo + hi) / 2;
2804 int cmp = hashcmp(index + mi * stride, sha1);
2806 if (debug_lookup)
2807 printf("lo %u hi %u rg %u mi %u\n",
2808 lo, hi, hi - lo, mi);
2809 if (!cmp)
2810 return nth_packed_object_offset(p, mi);
2811 if (cmp > 0)
2812 hi = mi;
2813 else
2814 lo = mi+1;
2815 } while (lo < hi);
2816 return 0;
2819 int is_pack_valid(struct packed_git *p)
2821 /* An already open pack is known to be valid. */
2822 if (p->pack_fd != -1)
2823 return 1;
2825 /* If the pack has one window completely covering the
2826 * file size, the pack is known to be valid even if
2827 * the descriptor is not currently open.
2829 if (p->windows) {
2830 struct pack_window *w = p->windows;
2832 if (!w->offset && w->len == p->pack_size)
2833 return 1;
2836 /* Force the pack to open to prove its valid. */
2837 return !open_packed_git(p);
2840 static int fill_pack_entry(const unsigned char *sha1,
2841 struct pack_entry *e,
2842 struct packed_git *p)
2844 off_t offset;
2846 if (p->num_bad_objects) {
2847 unsigned i;
2848 for (i = 0; i < p->num_bad_objects; i++)
2849 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2850 return 0;
2853 offset = find_pack_entry_one(sha1, p);
2854 if (!offset)
2855 return 0;
2858 * We are about to tell the caller where they can locate the
2859 * requested object. We better make sure the packfile is
2860 * still here and can be accessed before supplying that
2861 * answer, as it may have been deleted since the index was
2862 * loaded!
2864 if (!is_pack_valid(p))
2865 return 0;
2866 e->offset = offset;
2867 e->p = p;
2868 hashcpy(e->sha1, sha1);
2869 return 1;
2873 * Iff a pack file contains the object named by sha1, return true and
2874 * store its location to e.
2876 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2878 struct mru_entry *p;
2880 prepare_packed_git();
2881 if (!packed_git)
2882 return 0;
2884 for (p = packed_git_mru->head; p; p = p->next) {
2885 if (fill_pack_entry(sha1, e, p->item)) {
2886 mru_mark(packed_git_mru, p);
2887 return 1;
2890 return 0;
2893 struct packed_git *find_sha1_pack(const unsigned char *sha1,
2894 struct packed_git *packs)
2896 struct packed_git *p;
2898 for (p = packs; p; p = p->next) {
2899 if (find_pack_entry_one(sha1, p))
2900 return p;
2902 return NULL;
2906 static int sha1_loose_object_info(const unsigned char *sha1,
2907 struct object_info *oi,
2908 int flags)
2910 int status = 0;
2911 unsigned long mapsize;
2912 void *map;
2913 git_zstream stream;
2914 char hdr[32];
2915 struct strbuf hdrbuf = STRBUF_INIT;
2916 unsigned long size_scratch;
2918 if (oi->delta_base_sha1)
2919 hashclr(oi->delta_base_sha1);
2922 * If we don't care about type or size, then we don't
2923 * need to look inside the object at all. Note that we
2924 * do not optimize out the stat call, even if the
2925 * caller doesn't care about the disk-size, since our
2926 * return value implicitly indicates whether the
2927 * object even exists.
2929 if (!oi->typep && !oi->typename && !oi->sizep && !oi->contentp) {
2930 const char *path;
2931 struct stat st;
2932 if (stat_sha1_file(sha1, &st, &path) < 0)
2933 return -1;
2934 if (oi->disk_sizep)
2935 *oi->disk_sizep = st.st_size;
2936 return 0;
2939 map = map_sha1_file(sha1, &mapsize);
2940 if (!map)
2941 return -1;
2943 if (!oi->sizep)
2944 oi->sizep = &size_scratch;
2946 if (oi->disk_sizep)
2947 *oi->disk_sizep = mapsize;
2948 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
2949 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2950 status = error("unable to unpack %s header with --allow-unknown-type",
2951 sha1_to_hex(sha1));
2952 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2953 status = error("unable to unpack %s header",
2954 sha1_to_hex(sha1));
2955 if (status < 0)
2956 ; /* Do nothing */
2957 else if (hdrbuf.len) {
2958 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2959 status = error("unable to parse %s header with --allow-unknown-type",
2960 sha1_to_hex(sha1));
2961 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
2962 status = error("unable to parse %s header", sha1_to_hex(sha1));
2964 if (status >= 0 && oi->contentp)
2965 *oi->contentp = unpack_sha1_rest(&stream, hdr,
2966 *oi->sizep, sha1);
2967 else
2968 git_inflate_end(&stream);
2970 munmap(map, mapsize);
2971 if (status && oi->typep)
2972 *oi->typep = status;
2973 if (oi->sizep == &size_scratch)
2974 oi->sizep = NULL;
2975 strbuf_release(&hdrbuf);
2976 return (status < 0) ? status : 0;
2979 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
2981 static struct object_info blank_oi = OBJECT_INFO_INIT;
2982 struct pack_entry e;
2983 int rtype;
2984 const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ?
2985 lookup_replace_object(sha1) :
2986 sha1;
2988 if (!oi)
2989 oi = &blank_oi;
2991 if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
2992 struct cached_object *co = find_cached_object(real);
2993 if (co) {
2994 if (oi->typep)
2995 *(oi->typep) = co->type;
2996 if (oi->sizep)
2997 *(oi->sizep) = co->size;
2998 if (oi->disk_sizep)
2999 *(oi->disk_sizep) = 0;
3000 if (oi->delta_base_sha1)
3001 hashclr(oi->delta_base_sha1);
3002 if (oi->typename)
3003 strbuf_addstr(oi->typename, typename(co->type));
3004 if (oi->contentp)
3005 *oi->contentp = xmemdupz(co->buf, co->size);
3006 oi->whence = OI_CACHED;
3007 return 0;
3011 if (!find_pack_entry(real, &e)) {
3012 /* Most likely it's a loose object. */
3013 if (!sha1_loose_object_info(real, oi, flags)) {
3014 oi->whence = OI_LOOSE;
3015 return 0;
3018 /* Not a loose object; someone else may have just packed it. */
3019 if (flags & OBJECT_INFO_QUICK) {
3020 return -1;
3021 } else {
3022 reprepare_packed_git();
3023 if (!find_pack_entry(real, &e))
3024 return -1;
3028 if (oi == &blank_oi)
3030 * We know that the caller doesn't actually need the
3031 * information below, so return early.
3033 return 0;
3035 rtype = packed_object_info(e.p, e.offset, oi);
3036 if (rtype < 0) {
3037 mark_bad_packed_object(e.p, real);
3038 return sha1_object_info_extended(real, oi, 0);
3039 } else if (in_delta_base_cache(e.p, e.offset)) {
3040 oi->whence = OI_DBCACHED;
3041 } else {
3042 oi->whence = OI_PACKED;
3043 oi->u.packed.offset = e.offset;
3044 oi->u.packed.pack = e.p;
3045 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
3046 rtype == OBJ_OFS_DELTA);
3049 return 0;
3052 /* returns enum object_type or negative */
3053 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
3055 enum object_type type;
3056 struct object_info oi = OBJECT_INFO_INIT;
3058 oi.typep = &type;
3059 oi.sizep = sizep;
3060 if (sha1_object_info_extended(sha1, &oi,
3061 OBJECT_INFO_LOOKUP_REPLACE) < 0)
3062 return -1;
3063 return type;
3066 static void *read_packed_sha1(const unsigned char *sha1,
3067 enum object_type *type, unsigned long *size)
3069 struct pack_entry e;
3070 void *data;
3072 if (!find_pack_entry(sha1, &e))
3073 return NULL;
3074 data = cache_or_unpack_entry(e.p, e.offset, size, type);
3075 if (!data) {
3077 * We're probably in deep shit, but let's try to fetch
3078 * the required object anyway from another pack or loose.
3079 * This should happen only in the presence of a corrupted
3080 * pack, and is better than failing outright.
3082 error("failed to read object %s at offset %"PRIuMAX" from %s",
3083 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
3084 mark_bad_packed_object(e.p, sha1);
3085 data = read_object(sha1, type, size);
3087 return data;
3090 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
3091 unsigned char *sha1)
3093 struct cached_object *co;
3095 hash_sha1_file(buf, len, typename(type), sha1);
3096 if (has_sha1_file(sha1) || find_cached_object(sha1))
3097 return 0;
3098 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
3099 co = &cached_objects[cached_object_nr++];
3100 co->size = len;
3101 co->type = type;
3102 co->buf = xmalloc(len);
3103 memcpy(co->buf, buf, len);
3104 hashcpy(co->sha1, sha1);
3105 return 0;
3108 static void *read_object(const unsigned char *sha1, enum object_type *type,
3109 unsigned long *size)
3111 struct object_info oi = OBJECT_INFO_INIT;
3112 void *content;
3113 oi.typep = type;
3114 oi.sizep = size;
3115 oi.contentp = &content;
3117 if (sha1_object_info_extended(sha1, &oi, 0) < 0)
3118 return NULL;
3119 return content;
3123 * This function dies on corrupt objects; the callers who want to
3124 * deal with them should arrange to call read_object() and give error
3125 * messages themselves.
3127 void *read_sha1_file_extended(const unsigned char *sha1,
3128 enum object_type *type,
3129 unsigned long *size,
3130 int lookup_replace)
3132 void *data;
3133 const struct packed_git *p;
3134 const char *path;
3135 struct stat st;
3136 const unsigned char *repl = lookup_replace ? lookup_replace_object(sha1)
3137 : sha1;
3139 errno = 0;
3140 data = read_object(repl, type, size);
3141 if (data)
3142 return data;
3144 if (errno && errno != ENOENT)
3145 die_errno("failed to read object %s", sha1_to_hex(sha1));
3147 /* die if we replaced an object with one that does not exist */
3148 if (repl != sha1)
3149 die("replacement %s not found for %s",
3150 sha1_to_hex(repl), sha1_to_hex(sha1));
3152 if (!stat_sha1_file(repl, &st, &path))
3153 die("loose object %s (stored in %s) is corrupt",
3154 sha1_to_hex(repl), path);
3156 if ((p = has_packed_and_bad(repl)) != NULL)
3157 die("packed object %s (stored in %s) is corrupt",
3158 sha1_to_hex(repl), p->pack_name);
3160 return NULL;
3163 void *read_object_with_reference(const unsigned char *sha1,
3164 const char *required_type_name,
3165 unsigned long *size,
3166 unsigned char *actual_sha1_return)
3168 enum object_type type, required_type;
3169 void *buffer;
3170 unsigned long isize;
3171 unsigned char actual_sha1[20];
3173 required_type = type_from_string(required_type_name);
3174 hashcpy(actual_sha1, sha1);
3175 while (1) {
3176 int ref_length = -1;
3177 const char *ref_type = NULL;
3179 buffer = read_sha1_file(actual_sha1, &type, &isize);
3180 if (!buffer)
3181 return NULL;
3182 if (type == required_type) {
3183 *size = isize;
3184 if (actual_sha1_return)
3185 hashcpy(actual_sha1_return, actual_sha1);
3186 return buffer;
3188 /* Handle references */
3189 else if (type == OBJ_COMMIT)
3190 ref_type = "tree ";
3191 else if (type == OBJ_TAG)
3192 ref_type = "object ";
3193 else {
3194 free(buffer);
3195 return NULL;
3197 ref_length = strlen(ref_type);
3199 if (ref_length + 40 > isize ||
3200 memcmp(buffer, ref_type, ref_length) ||
3201 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
3202 free(buffer);
3203 return NULL;
3205 free(buffer);
3206 /* Now we have the ID of the referred-to object in
3207 * actual_sha1. Check again. */
3211 static void write_sha1_file_prepare(const void *buf, unsigned long len,
3212 const char *type, unsigned char *sha1,
3213 char *hdr, int *hdrlen)
3215 git_SHA_CTX c;
3217 /* Generate the header */
3218 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
3220 /* Sha1.. */
3221 git_SHA1_Init(&c);
3222 git_SHA1_Update(&c, hdr, *hdrlen);
3223 git_SHA1_Update(&c, buf, len);
3224 git_SHA1_Final(sha1, &c);
3228 * Move the just written object into its final resting place.
3230 int finalize_object_file(const char *tmpfile, const char *filename)
3232 int ret = 0;
3234 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
3235 goto try_rename;
3236 else if (link(tmpfile, filename))
3237 ret = errno;
3240 * Coda hack - coda doesn't like cross-directory links,
3241 * so we fall back to a rename, which will mean that it
3242 * won't be able to check collisions, but that's not a
3243 * big deal.
3245 * The same holds for FAT formatted media.
3247 * When this succeeds, we just return. We have nothing
3248 * left to unlink.
3250 if (ret && ret != EEXIST) {
3251 try_rename:
3252 if (!rename(tmpfile, filename))
3253 goto out;
3254 ret = errno;
3256 unlink_or_warn(tmpfile);
3257 if (ret) {
3258 if (ret != EEXIST) {
3259 return error_errno("unable to write sha1 filename %s", filename);
3261 /* FIXME!!! Collision check here ? */
3264 out:
3265 if (adjust_shared_perm(filename))
3266 return error("unable to set permission to '%s'", filename);
3267 return 0;
3270 static int write_buffer(int fd, const void *buf, size_t len)
3272 if (write_in_full(fd, buf, len) < 0)
3273 return error_errno("file write error");
3274 return 0;
3277 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
3278 unsigned char *sha1)
3280 char hdr[32];
3281 int hdrlen = sizeof(hdr);
3282 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3283 return 0;
3286 /* Finalize a file on disk, and close it. */
3287 static void close_sha1_file(int fd)
3289 if (fsync_object_files)
3290 fsync_or_die(fd, "sha1 file");
3291 if (close(fd) != 0)
3292 die_errno("error when closing sha1 file");
3295 /* Size of directory component, including the ending '/' */
3296 static inline int directory_size(const char *filename)
3298 const char *s = strrchr(filename, '/');
3299 if (!s)
3300 return 0;
3301 return s - filename + 1;
3305 * This creates a temporary file in the same directory as the final
3306 * 'filename'
3308 * We want to avoid cross-directory filename renames, because those
3309 * can have problems on various filesystems (FAT, NFS, Coda).
3311 static int create_tmpfile(struct strbuf *tmp, const char *filename)
3313 int fd, dirlen = directory_size(filename);
3315 strbuf_reset(tmp);
3316 strbuf_add(tmp, filename, dirlen);
3317 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3318 fd = git_mkstemp_mode(tmp->buf, 0444);
3319 if (fd < 0 && dirlen && errno == ENOENT) {
3321 * Make sure the directory exists; note that the contents
3322 * of the buffer are undefined after mkstemp returns an
3323 * error, so we have to rewrite the whole buffer from
3324 * scratch.
3326 strbuf_reset(tmp);
3327 strbuf_add(tmp, filename, dirlen - 1);
3328 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
3329 return -1;
3330 if (adjust_shared_perm(tmp->buf))
3331 return -1;
3333 /* Try again */
3334 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3335 fd = git_mkstemp_mode(tmp->buf, 0444);
3337 return fd;
3340 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
3341 const void *buf, unsigned long len, time_t mtime)
3343 int fd, ret;
3344 unsigned char compressed[4096];
3345 git_zstream stream;
3346 git_SHA_CTX c;
3347 unsigned char parano_sha1[20];
3348 static struct strbuf tmp_file = STRBUF_INIT;
3349 const char *filename = sha1_file_name(sha1);
3351 fd = create_tmpfile(&tmp_file, filename);
3352 if (fd < 0) {
3353 if (errno == EACCES)
3354 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
3355 else
3356 return error_errno("unable to create temporary file");
3359 /* Set it up */
3360 git_deflate_init(&stream, zlib_compression_level);
3361 stream.next_out = compressed;
3362 stream.avail_out = sizeof(compressed);
3363 git_SHA1_Init(&c);
3365 /* First header.. */
3366 stream.next_in = (unsigned char *)hdr;
3367 stream.avail_in = hdrlen;
3368 while (git_deflate(&stream, 0) == Z_OK)
3369 ; /* nothing */
3370 git_SHA1_Update(&c, hdr, hdrlen);
3372 /* Then the data itself.. */
3373 stream.next_in = (void *)buf;
3374 stream.avail_in = len;
3375 do {
3376 unsigned char *in0 = stream.next_in;
3377 ret = git_deflate(&stream, Z_FINISH);
3378 git_SHA1_Update(&c, in0, stream.next_in - in0);
3379 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3380 die("unable to write sha1 file");
3381 stream.next_out = compressed;
3382 stream.avail_out = sizeof(compressed);
3383 } while (ret == Z_OK);
3385 if (ret != Z_STREAM_END)
3386 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
3387 ret = git_deflate_end_gently(&stream);
3388 if (ret != Z_OK)
3389 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
3390 git_SHA1_Final(parano_sha1, &c);
3391 if (hashcmp(sha1, parano_sha1) != 0)
3392 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
3394 close_sha1_file(fd);
3396 if (mtime) {
3397 struct utimbuf utb;
3398 utb.actime = mtime;
3399 utb.modtime = mtime;
3400 if (utime(tmp_file.buf, &utb) < 0)
3401 warning_errno("failed utime() on %s", tmp_file.buf);
3404 return finalize_object_file(tmp_file.buf, filename);
3407 static int freshen_loose_object(const unsigned char *sha1)
3409 return check_and_freshen(sha1, 1);
3412 static int freshen_packed_object(const unsigned char *sha1)
3414 struct pack_entry e;
3415 if (!find_pack_entry(sha1, &e))
3416 return 0;
3417 if (e.p->freshened)
3418 return 1;
3419 if (!freshen_file(e.p->pack_name))
3420 return 0;
3421 e.p->freshened = 1;
3422 return 1;
3425 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
3427 char hdr[32];
3428 int hdrlen = sizeof(hdr);
3430 /* Normally if we have it in the pack then we do not bother writing
3431 * it out into .git/objects/??/?{38} file.
3433 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3434 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3435 return 0;
3436 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3439 int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3440 unsigned char *sha1, unsigned flags)
3442 char *header;
3443 int hdrlen, status = 0;
3445 /* type string, SP, %lu of the length plus NUL must fit this */
3446 hdrlen = strlen(type) + 32;
3447 header = xmalloc(hdrlen);
3448 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3450 if (!(flags & HASH_WRITE_OBJECT))
3451 goto cleanup;
3452 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3453 goto cleanup;
3454 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3456 cleanup:
3457 free(header);
3458 return status;
3461 int force_object_loose(const unsigned char *sha1, time_t mtime)
3463 void *buf;
3464 unsigned long len;
3465 enum object_type type;
3466 char hdr[32];
3467 int hdrlen;
3468 int ret;
3470 if (has_loose_object(sha1))
3471 return 0;
3472 buf = read_packed_sha1(sha1, &type, &len);
3473 if (!buf)
3474 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
3475 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
3476 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3477 free(buf);
3479 return ret;
3482 int has_pack_index(const unsigned char *sha1)
3484 struct stat st;
3485 if (stat(sha1_pack_index_name(sha1), &st))
3486 return 0;
3487 return 1;
3490 int has_sha1_pack(const unsigned char *sha1)
3492 struct pack_entry e;
3493 return find_pack_entry(sha1, &e);
3496 int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
3498 if (!startup_info->have_repository)
3499 return 0;
3500 return sha1_object_info_extended(sha1, NULL,
3501 flags | OBJECT_INFO_SKIP_CACHED) >= 0;
3504 int has_object_file(const struct object_id *oid)
3506 return has_sha1_file(oid->hash);
3509 int has_object_file_with_flags(const struct object_id *oid, int flags)
3511 return has_sha1_file_with_flags(oid->hash, flags);
3514 static void check_tree(const void *buf, size_t size)
3516 struct tree_desc desc;
3517 struct name_entry entry;
3519 init_tree_desc(&desc, buf, size);
3520 while (tree_entry(&desc, &entry))
3521 /* do nothing
3522 * tree_entry() will die() on malformed entries */
3526 static void check_commit(const void *buf, size_t size)
3528 struct commit c;
3529 memset(&c, 0, sizeof(c));
3530 if (parse_commit_buffer(&c, buf, size))
3531 die("corrupt commit");
3534 static void check_tag(const void *buf, size_t size)
3536 struct tag t;
3537 memset(&t, 0, sizeof(t));
3538 if (parse_tag_buffer(&t, buf, size))
3539 die("corrupt tag");
3542 static int index_mem(unsigned char *sha1, void *buf, size_t size,
3543 enum object_type type,
3544 const char *path, unsigned flags)
3546 int ret, re_allocated = 0;
3547 int write_object = flags & HASH_WRITE_OBJECT;
3549 if (!type)
3550 type = OBJ_BLOB;
3553 * Convert blobs to git internal format
3555 if ((type == OBJ_BLOB) && path) {
3556 struct strbuf nbuf = STRBUF_INIT;
3557 if (convert_to_git(&the_index, path, buf, size, &nbuf,
3558 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
3559 buf = strbuf_detach(&nbuf, &size);
3560 re_allocated = 1;
3563 if (flags & HASH_FORMAT_CHECK) {
3564 if (type == OBJ_TREE)
3565 check_tree(buf, size);
3566 if (type == OBJ_COMMIT)
3567 check_commit(buf, size);
3568 if (type == OBJ_TAG)
3569 check_tag(buf, size);
3572 if (write_object)
3573 ret = write_sha1_file(buf, size, typename(type), sha1);
3574 else
3575 ret = hash_sha1_file(buf, size, typename(type), sha1);
3576 if (re_allocated)
3577 free(buf);
3578 return ret;
3581 static int index_stream_convert_blob(unsigned char *sha1, int fd,
3582 const char *path, unsigned flags)
3584 int ret;
3585 const int write_object = flags & HASH_WRITE_OBJECT;
3586 struct strbuf sbuf = STRBUF_INIT;
3588 assert(path);
3589 assert(would_convert_to_git_filter_fd(path));
3591 convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
3592 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3594 if (write_object)
3595 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3596 sha1);
3597 else
3598 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3599 sha1);
3600 strbuf_release(&sbuf);
3601 return ret;
3604 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3605 const char *path, unsigned flags)
3607 struct strbuf sbuf = STRBUF_INIT;
3608 int ret;
3610 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3611 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3612 else
3613 ret = -1;
3614 strbuf_release(&sbuf);
3615 return ret;
3618 #define SMALL_FILE_SIZE (32*1024)
3620 static int index_core(unsigned char *sha1, int fd, size_t size,
3621 enum object_type type, const char *path,
3622 unsigned flags)
3624 int ret;
3626 if (!size) {
3627 ret = index_mem(sha1, "", size, type, path, flags);
3628 } else if (size <= SMALL_FILE_SIZE) {
3629 char *buf = xmalloc(size);
3630 if (size == read_in_full(fd, buf, size))
3631 ret = index_mem(sha1, buf, size, type, path, flags);
3632 else
3633 ret = error_errno("short read");
3634 free(buf);
3635 } else {
3636 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3637 ret = index_mem(sha1, buf, size, type, path, flags);
3638 munmap(buf, size);
3640 return ret;
3644 * This creates one packfile per large blob unless bulk-checkin
3645 * machinery is "plugged".
3647 * This also bypasses the usual "convert-to-git" dance, and that is on
3648 * purpose. We could write a streaming version of the converting
3649 * functions and insert that before feeding the data to fast-import
3650 * (or equivalent in-core API described above). However, that is
3651 * somewhat complicated, as we do not know the size of the filter
3652 * result, which we need to know beforehand when writing a git object.
3653 * Since the primary motivation for trying to stream from the working
3654 * tree file and to avoid mmaping it in core is to deal with large
3655 * binary blobs, they generally do not want to get any conversion, and
3656 * callers should avoid this code path when filters are requested.
3658 static int index_stream(unsigned char *sha1, int fd, size_t size,
3659 enum object_type type, const char *path,
3660 unsigned flags)
3662 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3665 int index_fd(unsigned char *sha1, int fd, struct stat *st,
3666 enum object_type type, const char *path, unsigned flags)
3668 int ret;
3671 * Call xsize_t() only when needed to avoid potentially unnecessary
3672 * die() for large files.
3674 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3675 ret = index_stream_convert_blob(sha1, fd, path, flags);
3676 else if (!S_ISREG(st->st_mode))
3677 ret = index_pipe(sha1, fd, type, path, flags);
3678 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
3679 (path && would_convert_to_git(&the_index, path)))
3680 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3681 flags);
3682 else
3683 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3684 flags);
3685 close(fd);
3686 return ret;
3689 int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3691 int fd;
3692 struct strbuf sb = STRBUF_INIT;
3694 switch (st->st_mode & S_IFMT) {
3695 case S_IFREG:
3696 fd = open(path, O_RDONLY);
3697 if (fd < 0)
3698 return error_errno("open(\"%s\")", path);
3699 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3700 return error("%s: failed to insert into database",
3701 path);
3702 break;
3703 case S_IFLNK:
3704 if (strbuf_readlink(&sb, path, st->st_size))
3705 return error_errno("readlink(\"%s\")", path);
3706 if (!(flags & HASH_WRITE_OBJECT))
3707 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3708 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3709 return error("%s: failed to insert into database",
3710 path);
3711 strbuf_release(&sb);
3712 break;
3713 case S_IFDIR:
3714 return resolve_gitlink_ref(path, "HEAD", sha1);
3715 default:
3716 return error("%s: unsupported file type", path);
3718 return 0;
3721 int read_pack_header(int fd, struct pack_header *header)
3723 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3724 /* "eof before pack header was fully read" */
3725 return PH_ERROR_EOF;
3727 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3728 /* "protocol error (pack signature mismatch detected)" */
3729 return PH_ERROR_PACK_SIGNATURE;
3730 if (!pack_version_ok(header->hdr_version))
3731 /* "protocol error (pack version unsupported)" */
3732 return PH_ERROR_PROTOCOL;
3733 return 0;
3736 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3738 enum object_type type = sha1_object_info(sha1, NULL);
3739 if (type < 0)
3740 die("%s is not a valid object", sha1_to_hex(sha1));
3741 if (type != expect)
3742 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3743 typename(expect));
3746 int for_each_file_in_obj_subdir(unsigned int subdir_nr,
3747 struct strbuf *path,
3748 each_loose_object_fn obj_cb,
3749 each_loose_cruft_fn cruft_cb,
3750 each_loose_subdir_fn subdir_cb,
3751 void *data)
3753 size_t origlen, baselen;
3754 DIR *dir;
3755 struct dirent *de;
3756 int r = 0;
3758 if (subdir_nr > 0xff)
3759 BUG("invalid loose object subdirectory: %x", subdir_nr);
3761 origlen = path->len;
3762 strbuf_complete(path, '/');
3763 strbuf_addf(path, "%02x", subdir_nr);
3764 baselen = path->len;
3766 dir = opendir(path->buf);
3767 if (!dir) {
3768 if (errno != ENOENT)
3769 r = error_errno("unable to open %s", path->buf);
3770 strbuf_setlen(path, origlen);
3771 return r;
3774 while ((de = readdir(dir))) {
3775 if (is_dot_or_dotdot(de->d_name))
3776 continue;
3778 strbuf_setlen(path, baselen);
3779 strbuf_addf(path, "/%s", de->d_name);
3781 if (strlen(de->d_name) == GIT_SHA1_HEXSZ - 2) {
3782 char hex[GIT_MAX_HEXSZ+1];
3783 struct object_id oid;
3785 xsnprintf(hex, sizeof(hex), "%02x%s",
3786 subdir_nr, de->d_name);
3787 if (!get_oid_hex(hex, &oid)) {
3788 if (obj_cb) {
3789 r = obj_cb(&oid, path->buf, data);
3790 if (r)
3791 break;
3793 continue;
3797 if (cruft_cb) {
3798 r = cruft_cb(de->d_name, path->buf, data);
3799 if (r)
3800 break;
3803 closedir(dir);
3805 strbuf_setlen(path, baselen);
3806 if (!r && subdir_cb)
3807 r = subdir_cb(subdir_nr, path->buf, data);
3809 strbuf_setlen(path, origlen);
3811 return r;
3814 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
3815 each_loose_object_fn obj_cb,
3816 each_loose_cruft_fn cruft_cb,
3817 each_loose_subdir_fn subdir_cb,
3818 void *data)
3820 int r = 0;
3821 int i;
3823 for (i = 0; i < 256; i++) {
3824 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
3825 subdir_cb, data);
3826 if (r)
3827 break;
3830 return r;
3833 int for_each_loose_file_in_objdir(const char *path,
3834 each_loose_object_fn obj_cb,
3835 each_loose_cruft_fn cruft_cb,
3836 each_loose_subdir_fn subdir_cb,
3837 void *data)
3839 struct strbuf buf = STRBUF_INIT;
3840 int r;
3842 strbuf_addstr(&buf, path);
3843 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
3844 subdir_cb, data);
3845 strbuf_release(&buf);
3847 return r;
3850 struct loose_alt_odb_data {
3851 each_loose_object_fn *cb;
3852 void *data;
3855 static int loose_from_alt_odb(struct alternate_object_database *alt,
3856 void *vdata)
3858 struct loose_alt_odb_data *data = vdata;
3859 struct strbuf buf = STRBUF_INIT;
3860 int r;
3862 strbuf_addstr(&buf, alt->path);
3863 r = for_each_loose_file_in_objdir_buf(&buf,
3864 data->cb, NULL, NULL,
3865 data->data);
3866 strbuf_release(&buf);
3867 return r;
3870 int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
3872 struct loose_alt_odb_data alt;
3873 int r;
3875 r = for_each_loose_file_in_objdir(get_object_directory(),
3876 cb, NULL, NULL, data);
3877 if (r)
3878 return r;
3880 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
3881 return 0;
3883 alt.cb = cb;
3884 alt.data = data;
3885 return foreach_alt_odb(loose_from_alt_odb, &alt);
3888 static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
3890 uint32_t i;
3891 int r = 0;
3893 for (i = 0; i < p->num_objects; i++) {
3894 struct object_id oid;
3896 if (!nth_packed_object_oid(&oid, p, i))
3897 return error("unable to get sha1 of object %u in %s",
3898 i, p->pack_name);
3900 r = cb(&oid, p, i, data);
3901 if (r)
3902 break;
3904 return r;
3907 int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
3909 struct packed_git *p;
3910 int r = 0;
3911 int pack_errors = 0;
3913 prepare_packed_git();
3914 for (p = packed_git; p; p = p->next) {
3915 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
3916 continue;
3917 if (open_pack_index(p)) {
3918 pack_errors = 1;
3919 continue;
3921 r = for_each_object_in_pack(p, cb, data);
3922 if (r)
3923 break;
3925 return r ? r : pack_errors;
3928 static int check_stream_sha1(git_zstream *stream,
3929 const char *hdr,
3930 unsigned long size,
3931 const char *path,
3932 const unsigned char *expected_sha1)
3934 git_SHA_CTX c;
3935 unsigned char real_sha1[GIT_MAX_RAWSZ];
3936 unsigned char buf[4096];
3937 unsigned long total_read;
3938 int status = Z_OK;
3940 git_SHA1_Init(&c);
3941 git_SHA1_Update(&c, hdr, stream->total_out);
3944 * We already read some bytes into hdr, but the ones up to the NUL
3945 * do not count against the object's content size.
3947 total_read = stream->total_out - strlen(hdr) - 1;
3950 * This size comparison must be "<=" to read the final zlib packets;
3951 * see the comment in unpack_sha1_rest for details.
3953 while (total_read <= size &&
3954 (status == Z_OK || status == Z_BUF_ERROR)) {
3955 stream->next_out = buf;
3956 stream->avail_out = sizeof(buf);
3957 if (size - total_read < stream->avail_out)
3958 stream->avail_out = size - total_read;
3959 status = git_inflate(stream, Z_FINISH);
3960 git_SHA1_Update(&c, buf, stream->next_out - buf);
3961 total_read += stream->next_out - buf;
3963 git_inflate_end(stream);
3965 if (status != Z_STREAM_END) {
3966 error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
3967 return -1;
3969 if (stream->avail_in) {
3970 error("garbage at end of loose object '%s'",
3971 sha1_to_hex(expected_sha1));
3972 return -1;
3975 git_SHA1_Final(real_sha1, &c);
3976 if (hashcmp(expected_sha1, real_sha1)) {
3977 error("sha1 mismatch for %s (expected %s)", path,
3978 sha1_to_hex(expected_sha1));
3979 return -1;
3982 return 0;
3985 int read_loose_object(const char *path,
3986 const unsigned char *expected_sha1,
3987 enum object_type *type,
3988 unsigned long *size,
3989 void **contents)
3991 int ret = -1;
3992 void *map = NULL;
3993 unsigned long mapsize;
3994 git_zstream stream;
3995 char hdr[32];
3997 *contents = NULL;
3999 map = map_sha1_file_1(path, NULL, &mapsize);
4000 if (!map) {
4001 error_errno("unable to mmap %s", path);
4002 goto out;
4005 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
4006 error("unable to unpack header of %s", path);
4007 goto out;
4010 *type = parse_sha1_header(hdr, size);
4011 if (*type < 0) {
4012 error("unable to parse header of %s", path);
4013 git_inflate_end(&stream);
4014 goto out;
4017 if (*type == OBJ_BLOB) {
4018 if (check_stream_sha1(&stream, hdr, *size, path, expected_sha1) < 0)
4019 goto out;
4020 } else {
4021 *contents = unpack_sha1_rest(&stream, hdr, *size, expected_sha1);
4022 if (!*contents) {
4023 error("unable to unpack contents of %s", path);
4024 git_inflate_end(&stream);
4025 goto out;
4027 if (check_sha1_signature(expected_sha1, *contents,
4028 *size, typename(*type))) {
4029 error("sha1 mismatch for %s (expected %s)", path,
4030 sha1_to_hex(expected_sha1));
4031 free(*contents);
4032 goto out;
4036 ret = 0; /* everything checks out */
4038 out:
4039 if (map)
4040 munmap(map, mapsize);
4041 return ret;