branch: add test for -m renaming multiple config sections
[git.git] / sha1_file.c
blob59a4ed2ed32336b41ab8f3b1d4aca30f045aa084
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "string-list.h"
11 #include "lockfile.h"
12 #include "delta.h"
13 #include "pack.h"
14 #include "blob.h"
15 #include "commit.h"
16 #include "run-command.h"
17 #include "tag.h"
18 #include "tree.h"
19 #include "tree-walk.h"
20 #include "refs.h"
21 #include "pack-revindex.h"
22 #include "sha1-lookup.h"
23 #include "bulk-checkin.h"
24 #include "streaming.h"
25 #include "dir.h"
26 #include "mru.h"
27 #include "list.h"
28 #include "mergesort.h"
29 #include "quote.h"
31 #define SZ_FMT PRIuMAX
32 static inline uintmax_t sz_fmt(size_t s) { return s; }
34 const unsigned char null_sha1[20];
35 const struct object_id null_oid;
36 const struct object_id empty_tree_oid = {
37 EMPTY_TREE_SHA1_BIN_LITERAL
39 const struct object_id empty_blob_oid = {
40 EMPTY_BLOB_SHA1_BIN_LITERAL
44 * This is meant to hold a *small* number of objects that you would
45 * want read_sha1_file() to be able to return, but yet you do not want
46 * to write them into the object store (e.g. a browse-only
47 * application).
49 static struct cached_object {
50 unsigned char sha1[20];
51 enum object_type type;
52 void *buf;
53 unsigned long size;
54 } *cached_objects;
55 static int cached_object_nr, cached_object_alloc;
57 static struct cached_object empty_tree = {
58 EMPTY_TREE_SHA1_BIN_LITERAL,
59 OBJ_TREE,
60 "",
64 static struct cached_object *find_cached_object(const unsigned char *sha1)
66 int i;
67 struct cached_object *co = cached_objects;
69 for (i = 0; i < cached_object_nr; i++, co++) {
70 if (!hashcmp(co->sha1, sha1))
71 return co;
73 if (!hashcmp(sha1, empty_tree.sha1))
74 return &empty_tree;
75 return NULL;
78 int mkdir_in_gitdir(const char *path)
80 if (mkdir(path, 0777)) {
81 int saved_errno = errno;
82 struct stat st;
83 struct strbuf sb = STRBUF_INIT;
85 if (errno != EEXIST)
86 return -1;
88 * Are we looking at a path in a symlinked worktree
89 * whose original repository does not yet have it?
90 * e.g. .git/rr-cache pointing at its original
91 * repository in which the user hasn't performed any
92 * conflict resolution yet?
94 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
95 strbuf_readlink(&sb, path, st.st_size) ||
96 !is_absolute_path(sb.buf) ||
97 mkdir(sb.buf, 0777)) {
98 strbuf_release(&sb);
99 errno = saved_errno;
100 return -1;
102 strbuf_release(&sb);
104 return adjust_shared_perm(path);
107 enum scld_error safe_create_leading_directories(char *path)
109 char *next_component = path + offset_1st_component(path);
110 enum scld_error ret = SCLD_OK;
112 while (ret == SCLD_OK && next_component) {
113 struct stat st;
114 char *slash = next_component, slash_character;
116 while (*slash && !is_dir_sep(*slash))
117 slash++;
119 if (!*slash)
120 break;
122 next_component = slash + 1;
123 while (is_dir_sep(*next_component))
124 next_component++;
125 if (!*next_component)
126 break;
128 slash_character = *slash;
129 *slash = '\0';
130 if (!stat(path, &st)) {
131 /* path exists */
132 if (!S_ISDIR(st.st_mode)) {
133 errno = ENOTDIR;
134 ret = SCLD_EXISTS;
136 } else if (mkdir(path, 0777)) {
137 if (errno == EEXIST &&
138 !stat(path, &st) && S_ISDIR(st.st_mode))
139 ; /* somebody created it since we checked */
140 else if (errno == ENOENT)
142 * Either mkdir() failed because
143 * somebody just pruned the containing
144 * directory, or stat() failed because
145 * the file that was in our way was
146 * just removed. Either way, inform
147 * the caller that it might be worth
148 * trying again:
150 ret = SCLD_VANISHED;
151 else
152 ret = SCLD_FAILED;
153 } else if (adjust_shared_perm(path)) {
154 ret = SCLD_PERMS;
156 *slash = slash_character;
158 return ret;
161 enum scld_error safe_create_leading_directories_const(const char *path)
163 int save_errno;
164 /* path points to cache entries, so xstrdup before messing with it */
165 char *buf = xstrdup(path);
166 enum scld_error result = safe_create_leading_directories(buf);
168 save_errno = errno;
169 free(buf);
170 errno = save_errno;
171 return result;
174 int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
177 * The number of times we will try to remove empty directories
178 * in the way of path. This is only 1 because if another
179 * process is racily creating directories that conflict with
180 * us, we don't want to fight against them.
182 int remove_directories_remaining = 1;
185 * The number of times that we will try to create the
186 * directories containing path. We are willing to attempt this
187 * more than once, because another process could be trying to
188 * clean up empty directories at the same time as we are
189 * trying to create them.
191 int create_directories_remaining = 3;
193 /* A scratch copy of path, filled lazily if we need it: */
194 struct strbuf path_copy = STRBUF_INIT;
196 int ret, save_errno;
198 /* Sanity check: */
199 assert(*path);
201 retry_fn:
202 ret = fn(path, cb);
203 save_errno = errno;
204 if (!ret)
205 goto out;
207 if (errno == EISDIR && remove_directories_remaining-- > 0) {
209 * A directory is in the way. Maybe it is empty; try
210 * to remove it:
212 if (!path_copy.len)
213 strbuf_addstr(&path_copy, path);
215 if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
216 goto retry_fn;
217 } else if (errno == ENOENT && create_directories_remaining-- > 0) {
219 * Maybe the containing directory didn't exist, or
220 * maybe it was just deleted by a process that is
221 * racing with us to clean up empty directories. Try
222 * to create it:
224 enum scld_error scld_result;
226 if (!path_copy.len)
227 strbuf_addstr(&path_copy, path);
229 do {
230 scld_result = safe_create_leading_directories(path_copy.buf);
231 if (scld_result == SCLD_OK)
232 goto retry_fn;
233 } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
236 out:
237 strbuf_release(&path_copy);
238 errno = save_errno;
239 return ret;
242 static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
244 int i;
245 for (i = 0; i < 20; i++) {
246 static char hex[] = "0123456789abcdef";
247 unsigned int val = sha1[i];
248 strbuf_addch(buf, hex[val >> 4]);
249 strbuf_addch(buf, hex[val & 0xf]);
250 if (!i)
251 strbuf_addch(buf, '/');
255 const char *sha1_file_name(const unsigned char *sha1)
257 static struct strbuf buf = STRBUF_INIT;
259 strbuf_reset(&buf);
260 strbuf_addf(&buf, "%s/", get_object_directory());
262 fill_sha1_path(&buf, sha1);
263 return buf.buf;
266 struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
268 strbuf_setlen(&alt->scratch, alt->base_len);
269 return &alt->scratch;
272 static const char *alt_sha1_path(struct alternate_object_database *alt,
273 const unsigned char *sha1)
275 struct strbuf *buf = alt_scratch_buf(alt);
276 fill_sha1_path(buf, sha1);
277 return buf->buf;
280 char *odb_pack_name(struct strbuf *buf,
281 const unsigned char *sha1,
282 const char *ext)
284 strbuf_reset(buf);
285 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
286 sha1_to_hex(sha1), ext);
287 return buf->buf;
290 char *sha1_pack_name(const unsigned char *sha1)
292 static struct strbuf buf = STRBUF_INIT;
293 return odb_pack_name(&buf, sha1, "pack");
296 char *sha1_pack_index_name(const unsigned char *sha1)
298 static struct strbuf buf = STRBUF_INIT;
299 return odb_pack_name(&buf, sha1, "idx");
302 struct alternate_object_database *alt_odb_list;
303 static struct alternate_object_database **alt_odb_tail;
306 * Return non-zero iff the path is usable as an alternate object database.
308 static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
310 struct alternate_object_database *alt;
312 /* Detect cases where alternate disappeared */
313 if (!is_directory(path->buf)) {
314 error("object directory %s does not exist; "
315 "check .git/objects/info/alternates.",
316 path->buf);
317 return 0;
321 * Prevent the common mistake of listing the same
322 * thing twice, or object directory itself.
324 for (alt = alt_odb_list; alt; alt = alt->next) {
325 if (!fspathcmp(path->buf, alt->path))
326 return 0;
328 if (!fspathcmp(path->buf, normalized_objdir))
329 return 0;
331 return 1;
335 * Prepare alternate object database registry.
337 * The variable alt_odb_list points at the list of struct
338 * alternate_object_database. The elements on this list come from
339 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
340 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
341 * whose contents is similar to that environment variable but can be
342 * LF separated. Its base points at a statically allocated buffer that
343 * contains "/the/directory/corresponding/to/.git/objects/...", while
344 * its name points just after the slash at the end of ".git/objects/"
345 * in the example above, and has enough space to hold 40-byte hex
346 * SHA1, an extra slash for the first level indirection, and the
347 * terminating NUL.
349 static int link_alt_odb_entry(const char *entry, const char *relative_base,
350 int depth, const char *normalized_objdir)
352 struct alternate_object_database *ent;
353 struct strbuf pathbuf = STRBUF_INIT;
355 if (!is_absolute_path(entry) && relative_base) {
356 strbuf_realpath(&pathbuf, relative_base, 1);
357 strbuf_addch(&pathbuf, '/');
359 strbuf_addstr(&pathbuf, entry);
361 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
362 error("unable to normalize alternate object path: %s",
363 pathbuf.buf);
364 strbuf_release(&pathbuf);
365 return -1;
369 * The trailing slash after the directory name is given by
370 * this function at the end. Remove duplicates.
372 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
373 strbuf_setlen(&pathbuf, pathbuf.len - 1);
375 if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
376 strbuf_release(&pathbuf);
377 return -1;
380 ent = alloc_alt_odb(pathbuf.buf);
382 /* add the alternate entry */
383 *alt_odb_tail = ent;
384 alt_odb_tail = &(ent->next);
385 ent->next = NULL;
387 /* recursively add alternates */
388 read_info_alternates(pathbuf.buf, depth + 1);
390 strbuf_release(&pathbuf);
391 return 0;
394 static const char *parse_alt_odb_entry(const char *string,
395 int sep,
396 struct strbuf *out)
398 const char *end;
400 strbuf_reset(out);
402 if (*string == '#') {
403 /* comment; consume up to next separator */
404 end = strchrnul(string, sep);
405 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
407 * quoted path; unquote_c_style has copied the
408 * data for us and set "end". Broken quoting (e.g.,
409 * an entry that doesn't end with a quote) falls
410 * back to the unquoted case below.
412 } else {
413 /* normal, unquoted path */
414 end = strchrnul(string, sep);
415 strbuf_add(out, string, end - string);
418 if (*end)
419 end++;
420 return end;
423 static void link_alt_odb_entries(const char *alt, int len, int sep,
424 const char *relative_base, int depth)
426 struct strbuf objdirbuf = STRBUF_INIT;
427 struct strbuf entry = STRBUF_INIT;
429 if (depth > 5) {
430 error("%s: ignoring alternate object stores, nesting too deep.",
431 relative_base);
432 return;
435 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
436 if (strbuf_normalize_path(&objdirbuf) < 0)
437 die("unable to normalize object directory: %s",
438 objdirbuf.buf);
440 while (*alt) {
441 alt = parse_alt_odb_entry(alt, sep, &entry);
442 if (!entry.len)
443 continue;
444 link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
446 strbuf_release(&entry);
447 strbuf_release(&objdirbuf);
450 void read_info_alternates(const char * relative_base, int depth)
452 char *map;
453 size_t mapsz;
454 struct stat st;
455 char *path;
456 int fd;
458 path = xstrfmt("%s/info/alternates", relative_base);
459 fd = git_open(path);
460 free(path);
461 if (fd < 0)
462 return;
463 if (fstat(fd, &st) || (st.st_size == 0)) {
464 close(fd);
465 return;
467 mapsz = xsize_t(st.st_size);
468 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
469 close(fd);
471 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
473 munmap(map, mapsz);
476 struct alternate_object_database *alloc_alt_odb(const char *dir)
478 struct alternate_object_database *ent;
480 FLEX_ALLOC_STR(ent, path, dir);
481 strbuf_init(&ent->scratch, 0);
482 strbuf_addf(&ent->scratch, "%s/", dir);
483 ent->base_len = ent->scratch.len;
485 return ent;
488 void add_to_alternates_file(const char *reference)
490 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
491 char *alts = git_pathdup("objects/info/alternates");
492 FILE *in, *out;
494 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
495 out = fdopen_lock_file(lock, "w");
496 if (!out)
497 die_errno("unable to fdopen alternates lockfile");
499 in = fopen(alts, "r");
500 if (in) {
501 struct strbuf line = STRBUF_INIT;
502 int found = 0;
504 while (strbuf_getline(&line, in) != EOF) {
505 if (!strcmp(reference, line.buf)) {
506 found = 1;
507 break;
509 fprintf_or_die(out, "%s\n", line.buf);
512 strbuf_release(&line);
513 fclose(in);
515 if (found) {
516 rollback_lock_file(lock);
517 lock = NULL;
520 else if (errno != ENOENT)
521 die_errno("unable to read alternates file");
523 if (lock) {
524 fprintf_or_die(out, "%s\n", reference);
525 if (commit_lock_file(lock))
526 die_errno("unable to move new alternates file into place");
527 if (alt_odb_tail)
528 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
530 free(alts);
533 void add_to_alternates_memory(const char *reference)
536 * Make sure alternates are initialized, or else our entry may be
537 * overwritten when they are.
539 prepare_alt_odb();
541 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
545 * Compute the exact path an alternate is at and returns it. In case of
546 * error NULL is returned and the human readable error is added to `err`
547 * `path` may be relative and should point to $GITDIR.
548 * `err` must not be null.
550 char *compute_alternate_path(const char *path, struct strbuf *err)
552 char *ref_git = NULL;
553 const char *repo, *ref_git_s;
554 int seen_error = 0;
556 ref_git_s = real_path_if_valid(path);
557 if (!ref_git_s) {
558 seen_error = 1;
559 strbuf_addf(err, _("path '%s' does not exist"), path);
560 goto out;
561 } else
563 * Beware: read_gitfile(), real_path() and mkpath()
564 * return static buffer
566 ref_git = xstrdup(ref_git_s);
568 repo = read_gitfile(ref_git);
569 if (!repo)
570 repo = read_gitfile(mkpath("%s/.git", ref_git));
571 if (repo) {
572 free(ref_git);
573 ref_git = xstrdup(repo);
576 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
577 char *ref_git_git = mkpathdup("%s/.git", ref_git);
578 free(ref_git);
579 ref_git = ref_git_git;
580 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
581 struct strbuf sb = STRBUF_INIT;
582 seen_error = 1;
583 if (get_common_dir(&sb, ref_git)) {
584 strbuf_addf(err,
585 _("reference repository '%s' as a linked "
586 "checkout is not supported yet."),
587 path);
588 goto out;
591 strbuf_addf(err, _("reference repository '%s' is not a "
592 "local repository."), path);
593 goto out;
596 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
597 strbuf_addf(err, _("reference repository '%s' is shallow"),
598 path);
599 seen_error = 1;
600 goto out;
603 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
604 strbuf_addf(err,
605 _("reference repository '%s' is grafted"),
606 path);
607 seen_error = 1;
608 goto out;
611 out:
612 if (seen_error) {
613 free(ref_git);
614 ref_git = NULL;
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_GETFL) && defined(F_SETFL) && 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_GETFL);
1694 if (fcntl(fd, F_SETFL, 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 & LOOKUP_UNKNOWN_OBJECT) && (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, LOOKUP_REPLACE_OBJECT);
2008 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
2010 int ret;
2011 git_zstream stream;
2012 char hdr[8192];
2014 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
2015 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
2016 return NULL;
2018 return unpack_sha1_rest(&stream, hdr, *size, sha1);
2021 unsigned long get_size_from_delta(struct packed_git *p,
2022 struct pack_window **w_curs,
2023 off_t curpos)
2025 const unsigned char *data;
2026 unsigned char delta_head[20], *in;
2027 git_zstream stream;
2028 int st;
2030 memset(&stream, 0, sizeof(stream));
2031 stream.next_out = delta_head;
2032 stream.avail_out = sizeof(delta_head);
2034 git_inflate_init(&stream);
2035 do {
2036 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2037 stream.next_in = in;
2038 st = git_inflate(&stream, Z_FINISH);
2039 curpos += stream.next_in - in;
2040 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
2041 stream.total_out < sizeof(delta_head));
2042 git_inflate_end(&stream);
2043 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
2044 error("delta data unpack-initial failed");
2045 return 0;
2048 /* Examine the initial part of the delta to figure out
2049 * the result size.
2051 data = delta_head;
2053 /* ignore base size */
2054 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2056 /* Read the result size */
2057 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2060 static off_t get_delta_base(struct packed_git *p,
2061 struct pack_window **w_curs,
2062 off_t *curpos,
2063 enum object_type type,
2064 off_t delta_obj_offset)
2066 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
2067 off_t base_offset;
2069 /* use_pack() assured us we have [base_info, base_info + 20)
2070 * as a range that we can look at without walking off the
2071 * end of the mapped window. Its actually the hash size
2072 * that is assured. An OFS_DELTA longer than the hash size
2073 * is stupid, as then a REF_DELTA would be smaller to store.
2075 if (type == OBJ_OFS_DELTA) {
2076 unsigned used = 0;
2077 unsigned char c = base_info[used++];
2078 base_offset = c & 127;
2079 while (c & 128) {
2080 base_offset += 1;
2081 if (!base_offset || MSB(base_offset, 7))
2082 return 0; /* overflow */
2083 c = base_info[used++];
2084 base_offset = (base_offset << 7) + (c & 127);
2086 base_offset = delta_obj_offset - base_offset;
2087 if (base_offset <= 0 || base_offset >= delta_obj_offset)
2088 return 0; /* out of bound */
2089 *curpos += used;
2090 } else if (type == OBJ_REF_DELTA) {
2091 /* The base entry _must_ be in the same pack */
2092 base_offset = find_pack_entry_one(base_info, p);
2093 *curpos += 20;
2094 } else
2095 die("I am totally screwed");
2096 return base_offset;
2100 * Like get_delta_base above, but we return the sha1 instead of the pack
2101 * offset. This means it is cheaper for REF deltas (we do not have to do
2102 * the final object lookup), but more expensive for OFS deltas (we
2103 * have to load the revidx to convert the offset back into a sha1).
2105 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
2106 struct pack_window **w_curs,
2107 off_t curpos,
2108 enum object_type type,
2109 off_t delta_obj_offset)
2111 if (type == OBJ_REF_DELTA) {
2112 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
2113 return base;
2114 } else if (type == OBJ_OFS_DELTA) {
2115 struct revindex_entry *revidx;
2116 off_t base_offset = get_delta_base(p, w_curs, &curpos,
2117 type, delta_obj_offset);
2119 if (!base_offset)
2120 return NULL;
2122 revidx = find_pack_revindex(p, base_offset);
2123 if (!revidx)
2124 return NULL;
2126 return nth_packed_object_sha1(p, revidx->nr);
2127 } else
2128 return NULL;
2131 int unpack_object_header(struct packed_git *p,
2132 struct pack_window **w_curs,
2133 off_t *curpos,
2134 unsigned long *sizep)
2136 unsigned char *base;
2137 unsigned long left;
2138 unsigned long used;
2139 enum object_type type;
2141 /* use_pack() assures us we have [base, base + 20) available
2142 * as a range that we can look at. (Its actually the hash
2143 * size that is assured.) With our object header encoding
2144 * the maximum deflated object size is 2^137, which is just
2145 * insane, so we know won't exceed what we have been given.
2147 base = use_pack(p, w_curs, *curpos, &left);
2148 used = unpack_object_header_buffer(base, left, &type, sizep);
2149 if (!used) {
2150 type = OBJ_BAD;
2151 } else
2152 *curpos += used;
2154 return type;
2157 static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
2159 int type;
2160 struct revindex_entry *revidx;
2161 const unsigned char *sha1;
2162 revidx = find_pack_revindex(p, obj_offset);
2163 if (!revidx)
2164 return OBJ_BAD;
2165 sha1 = nth_packed_object_sha1(p, revidx->nr);
2166 mark_bad_packed_object(p, sha1);
2167 type = sha1_object_info(sha1, NULL);
2168 if (type <= OBJ_NONE)
2169 return OBJ_BAD;
2170 return type;
2173 #define POI_STACK_PREALLOC 64
2175 static enum object_type packed_to_object_type(struct packed_git *p,
2176 off_t obj_offset,
2177 enum object_type type,
2178 struct pack_window **w_curs,
2179 off_t curpos)
2181 off_t small_poi_stack[POI_STACK_PREALLOC];
2182 off_t *poi_stack = small_poi_stack;
2183 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
2185 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2186 off_t base_offset;
2187 unsigned long size;
2188 /* Push the object we're going to leave behind */
2189 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
2190 poi_stack_alloc = alloc_nr(poi_stack_nr);
2191 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
2192 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
2193 } else {
2194 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
2196 poi_stack[poi_stack_nr++] = obj_offset;
2197 /* If parsing the base offset fails, just unwind */
2198 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
2199 if (!base_offset)
2200 goto unwind;
2201 curpos = obj_offset = base_offset;
2202 type = unpack_object_header(p, w_curs, &curpos, &size);
2203 if (type <= OBJ_NONE) {
2204 /* If getting the base itself fails, we first
2205 * retry the base, otherwise unwind */
2206 type = retry_bad_packed_offset(p, base_offset);
2207 if (type > OBJ_NONE)
2208 goto out;
2209 goto unwind;
2213 switch (type) {
2214 case OBJ_BAD:
2215 case OBJ_COMMIT:
2216 case OBJ_TREE:
2217 case OBJ_BLOB:
2218 case OBJ_TAG:
2219 break;
2220 default:
2221 error("unknown object type %i at offset %"PRIuMAX" in %s",
2222 type, (uintmax_t)obj_offset, p->pack_name);
2223 type = OBJ_BAD;
2226 out:
2227 if (poi_stack != small_poi_stack)
2228 free(poi_stack);
2229 return type;
2231 unwind:
2232 while (poi_stack_nr) {
2233 obj_offset = poi_stack[--poi_stack_nr];
2234 type = retry_bad_packed_offset(p, obj_offset);
2235 if (type > OBJ_NONE)
2236 goto out;
2238 type = OBJ_BAD;
2239 goto out;
2242 int packed_object_info(struct packed_git *p, off_t obj_offset,
2243 struct object_info *oi)
2245 struct pack_window *w_curs = NULL;
2246 unsigned long size;
2247 off_t curpos = obj_offset;
2248 enum object_type type;
2251 * We always get the representation type, but only convert it to
2252 * a "real" type later if the caller is interested.
2254 type = unpack_object_header(p, &w_curs, &curpos, &size);
2256 if (oi->sizep) {
2257 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2258 off_t tmp_pos = curpos;
2259 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2260 type, obj_offset);
2261 if (!base_offset) {
2262 type = OBJ_BAD;
2263 goto out;
2265 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2266 if (*oi->sizep == 0) {
2267 type = OBJ_BAD;
2268 goto out;
2270 } else {
2271 *oi->sizep = size;
2275 if (oi->disk_sizep) {
2276 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2277 *oi->disk_sizep = revidx[1].offset - obj_offset;
2280 if (oi->typep) {
2281 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
2282 if (*oi->typep < 0) {
2283 type = OBJ_BAD;
2284 goto out;
2288 if (oi->delta_base_sha1) {
2289 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2290 const unsigned char *base;
2292 base = get_delta_base_sha1(p, &w_curs, curpos,
2293 type, obj_offset);
2294 if (!base) {
2295 type = OBJ_BAD;
2296 goto out;
2299 hashcpy(oi->delta_base_sha1, base);
2300 } else
2301 hashclr(oi->delta_base_sha1);
2304 out:
2305 unuse_pack(&w_curs);
2306 return type;
2309 static void *unpack_compressed_entry(struct packed_git *p,
2310 struct pack_window **w_curs,
2311 off_t curpos,
2312 unsigned long size)
2314 int st;
2315 git_zstream stream;
2316 unsigned char *buffer, *in;
2318 buffer = xmallocz_gently(size);
2319 if (!buffer)
2320 return NULL;
2321 memset(&stream, 0, sizeof(stream));
2322 stream.next_out = buffer;
2323 stream.avail_out = size + 1;
2325 git_inflate_init(&stream);
2326 do {
2327 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2328 stream.next_in = in;
2329 st = git_inflate(&stream, Z_FINISH);
2330 if (!stream.avail_out)
2331 break; /* the payload is larger than it should be */
2332 curpos += stream.next_in - in;
2333 } while (st == Z_OK || st == Z_BUF_ERROR);
2334 git_inflate_end(&stream);
2335 if ((st != Z_STREAM_END) || stream.total_out != size) {
2336 free(buffer);
2337 return NULL;
2340 return buffer;
2343 static struct hashmap delta_base_cache;
2344 static size_t delta_base_cached;
2346 static LIST_HEAD(delta_base_cache_lru);
2348 struct delta_base_cache_key {
2349 struct packed_git *p;
2350 off_t base_offset;
2353 struct delta_base_cache_entry {
2354 struct hashmap hash;
2355 struct delta_base_cache_key key;
2356 struct list_head lru;
2357 void *data;
2358 unsigned long size;
2359 enum object_type type;
2362 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
2364 unsigned int hash;
2366 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
2367 hash += (hash >> 8) + (hash >> 16);
2368 return hash;
2371 static struct delta_base_cache_entry *
2372 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
2374 struct hashmap_entry entry;
2375 struct delta_base_cache_key key;
2377 if (!delta_base_cache.cmpfn)
2378 return NULL;
2380 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
2381 key.p = p;
2382 key.base_offset = base_offset;
2383 return hashmap_get(&delta_base_cache, &entry, &key);
2386 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
2387 const struct delta_base_cache_key *b)
2389 return a->p == b->p && a->base_offset == b->base_offset;
2392 static int delta_base_cache_hash_cmp(const void *va, const void *vb,
2393 const void *vkey)
2395 const struct delta_base_cache_entry *a = va, *b = vb;
2396 const struct delta_base_cache_key *key = vkey;
2397 if (key)
2398 return !delta_base_cache_key_eq(&a->key, key);
2399 else
2400 return !delta_base_cache_key_eq(&a->key, &b->key);
2403 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2405 return !!get_delta_base_cache_entry(p, base_offset);
2409 * Remove the entry from the cache, but do _not_ free the associated
2410 * entry data. The caller takes ownership of the "data" buffer, and
2411 * should copy out any fields it wants before detaching.
2413 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2415 hashmap_remove(&delta_base_cache, ent, &ent->key);
2416 list_del(&ent->lru);
2417 delta_base_cached -= ent->size;
2418 free(ent);
2421 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
2422 unsigned long *base_size, enum object_type *type)
2424 struct delta_base_cache_entry *ent;
2426 ent = get_delta_base_cache_entry(p, base_offset);
2427 if (!ent)
2428 return unpack_entry(p, base_offset, type, base_size);
2430 *type = ent->type;
2431 *base_size = ent->size;
2432 return xmemdupz(ent->data, ent->size);
2435 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2437 free(ent->data);
2438 detach_delta_base_cache_entry(ent);
2441 void clear_delta_base_cache(void)
2443 struct list_head *lru, *tmp;
2444 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2445 struct delta_base_cache_entry *entry =
2446 list_entry(lru, struct delta_base_cache_entry, lru);
2447 release_delta_base_cache(entry);
2451 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2452 void *base, unsigned long base_size, enum object_type type)
2454 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
2455 struct list_head *lru, *tmp;
2457 delta_base_cached += base_size;
2459 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2460 struct delta_base_cache_entry *f =
2461 list_entry(lru, struct delta_base_cache_entry, lru);
2462 if (delta_base_cached <= delta_base_cache_limit)
2463 break;
2464 release_delta_base_cache(f);
2467 ent->key.p = p;
2468 ent->key.base_offset = base_offset;
2469 ent->type = type;
2470 ent->data = base;
2471 ent->size = base_size;
2472 list_add_tail(&ent->lru, &delta_base_cache_lru);
2474 if (!delta_base_cache.cmpfn)
2475 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, 0);
2476 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
2477 hashmap_add(&delta_base_cache, ent);
2480 static void *read_object(const unsigned char *sha1, enum object_type *type,
2481 unsigned long *size);
2483 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2485 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2486 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2487 p->pack_name, (uintmax_t)obj_offset);
2490 int do_check_packed_object_crc;
2492 #define UNPACK_ENTRY_STACK_PREALLOC 64
2493 struct unpack_entry_stack_ent {
2494 off_t obj_offset;
2495 off_t curpos;
2496 unsigned long size;
2499 void *unpack_entry(struct packed_git *p, off_t obj_offset,
2500 enum object_type *final_type, unsigned long *final_size)
2502 struct pack_window *w_curs = NULL;
2503 off_t curpos = obj_offset;
2504 void *data = NULL;
2505 unsigned long size;
2506 enum object_type type;
2507 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2508 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2509 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2510 int base_from_cache = 0;
2512 write_pack_access_log(p, obj_offset);
2514 /* PHASE 1: drill down to the innermost base object */
2515 for (;;) {
2516 off_t base_offset;
2517 int i;
2518 struct delta_base_cache_entry *ent;
2520 ent = get_delta_base_cache_entry(p, curpos);
2521 if (ent) {
2522 type = ent->type;
2523 data = ent->data;
2524 size = ent->size;
2525 detach_delta_base_cache_entry(ent);
2526 base_from_cache = 1;
2527 break;
2530 if (do_check_packed_object_crc && p->index_version > 1) {
2531 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2532 off_t len = revidx[1].offset - obj_offset;
2533 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2534 const unsigned char *sha1 =
2535 nth_packed_object_sha1(p, revidx->nr);
2536 error("bad packed object CRC for %s",
2537 sha1_to_hex(sha1));
2538 mark_bad_packed_object(p, sha1);
2539 unuse_pack(&w_curs);
2540 return NULL;
2544 type = unpack_object_header(p, &w_curs, &curpos, &size);
2545 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2546 break;
2548 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2549 if (!base_offset) {
2550 error("failed to validate delta base reference "
2551 "at offset %"PRIuMAX" from %s",
2552 (uintmax_t)curpos, p->pack_name);
2553 /* bail to phase 2, in hopes of recovery */
2554 data = NULL;
2555 break;
2558 /* push object, proceed to base */
2559 if (delta_stack_nr >= delta_stack_alloc
2560 && delta_stack == small_delta_stack) {
2561 delta_stack_alloc = alloc_nr(delta_stack_nr);
2562 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
2563 memcpy(delta_stack, small_delta_stack,
2564 sizeof(*delta_stack)*delta_stack_nr);
2565 } else {
2566 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2568 i = delta_stack_nr++;
2569 delta_stack[i].obj_offset = obj_offset;
2570 delta_stack[i].curpos = curpos;
2571 delta_stack[i].size = size;
2573 curpos = obj_offset = base_offset;
2576 /* PHASE 2: handle the base */
2577 switch (type) {
2578 case OBJ_OFS_DELTA:
2579 case OBJ_REF_DELTA:
2580 if (data)
2581 die("BUG: unpack_entry: left loop at a valid delta");
2582 break;
2583 case OBJ_COMMIT:
2584 case OBJ_TREE:
2585 case OBJ_BLOB:
2586 case OBJ_TAG:
2587 if (!base_from_cache)
2588 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2589 break;
2590 default:
2591 data = NULL;
2592 error("unknown object type %i at offset %"PRIuMAX" in %s",
2593 type, (uintmax_t)obj_offset, p->pack_name);
2596 /* PHASE 3: apply deltas in order */
2598 /* invariants:
2599 * 'data' holds the base data, or NULL if there was corruption
2601 while (delta_stack_nr) {
2602 void *delta_data;
2603 void *base = data;
2604 void *external_base = NULL;
2605 unsigned long delta_size, base_size = size;
2606 int i;
2608 data = NULL;
2610 if (base)
2611 add_delta_base_cache(p, obj_offset, base, base_size, type);
2613 if (!base) {
2615 * We're probably in deep shit, but let's try to fetch
2616 * the required base anyway from another pack or loose.
2617 * This is costly but should happen only in the presence
2618 * of a corrupted pack, and is better than failing outright.
2620 struct revindex_entry *revidx;
2621 const unsigned char *base_sha1;
2622 revidx = find_pack_revindex(p, obj_offset);
2623 if (revidx) {
2624 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2625 error("failed to read delta base object %s"
2626 " at offset %"PRIuMAX" from %s",
2627 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2628 p->pack_name);
2629 mark_bad_packed_object(p, base_sha1);
2630 base = read_object(base_sha1, &type, &base_size);
2631 external_base = base;
2635 i = --delta_stack_nr;
2636 obj_offset = delta_stack[i].obj_offset;
2637 curpos = delta_stack[i].curpos;
2638 delta_size = delta_stack[i].size;
2640 if (!base)
2641 continue;
2643 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2645 if (!delta_data) {
2646 error("failed to unpack compressed delta "
2647 "at offset %"PRIuMAX" from %s",
2648 (uintmax_t)curpos, p->pack_name);
2649 data = NULL;
2650 free(external_base);
2651 continue;
2654 data = patch_delta(base, base_size,
2655 delta_data, delta_size,
2656 &size);
2659 * We could not apply the delta; warn the user, but keep going.
2660 * Our failure will be noticed either in the next iteration of
2661 * the loop, or if this is the final delta, in the caller when
2662 * we return NULL. Those code paths will take care of making
2663 * a more explicit warning and retrying with another copy of
2664 * the object.
2666 if (!data)
2667 error("failed to apply delta");
2669 free(delta_data);
2670 free(external_base);
2673 *final_type = type;
2674 *final_size = size;
2676 unuse_pack(&w_curs);
2678 if (delta_stack != small_delta_stack)
2679 free(delta_stack);
2681 return data;
2684 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2685 uint32_t n)
2687 const unsigned char *index = p->index_data;
2688 if (!index) {
2689 if (open_pack_index(p))
2690 return NULL;
2691 index = p->index_data;
2693 if (n >= p->num_objects)
2694 return NULL;
2695 index += 4 * 256;
2696 if (p->index_version == 1) {
2697 return index + 24 * n + 4;
2698 } else {
2699 index += 8;
2700 return index + 20 * n;
2704 const struct object_id *nth_packed_object_oid(struct object_id *oid,
2705 struct packed_git *p,
2706 uint32_t n)
2708 const unsigned char *hash = nth_packed_object_sha1(p, n);
2709 if (!hash)
2710 return NULL;
2711 hashcpy(oid->hash, hash);
2712 return oid;
2715 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2717 const unsigned char *ptr = vptr;
2718 const unsigned char *start = p->index_data;
2719 const unsigned char *end = start + p->index_size;
2720 if (ptr < start)
2721 die(_("offset before start of pack index for %s (corrupt index?)"),
2722 p->pack_name);
2723 /* No need to check for underflow; .idx files must be at least 8 bytes */
2724 if (ptr >= end - 8)
2725 die(_("offset beyond end of pack index for %s (truncated index?)"),
2726 p->pack_name);
2729 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2731 const unsigned char *index = p->index_data;
2732 index += 4 * 256;
2733 if (p->index_version == 1) {
2734 return ntohl(*((uint32_t *)(index + 24 * n)));
2735 } else {
2736 uint32_t off;
2737 index += 8 + p->num_objects * (20 + 4);
2738 off = ntohl(*((uint32_t *)(index + 4 * n)));
2739 if (!(off & 0x80000000))
2740 return off;
2741 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2742 check_pack_index_ptr(p, index);
2743 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2744 ntohl(*((uint32_t *)(index + 4)));
2748 off_t find_pack_entry_one(const unsigned char *sha1,
2749 struct packed_git *p)
2751 const uint32_t *level1_ofs = p->index_data;
2752 const unsigned char *index = p->index_data;
2753 unsigned hi, lo, stride;
2754 static int use_lookup = -1;
2755 static int debug_lookup = -1;
2757 if (debug_lookup < 0)
2758 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2760 if (!index) {
2761 if (open_pack_index(p))
2762 return 0;
2763 level1_ofs = p->index_data;
2764 index = p->index_data;
2766 if (p->index_version > 1) {
2767 level1_ofs += 2;
2768 index += 8;
2770 index += 4 * 256;
2771 hi = ntohl(level1_ofs[*sha1]);
2772 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2773 if (p->index_version > 1) {
2774 stride = 20;
2775 } else {
2776 stride = 24;
2777 index += 4;
2780 if (debug_lookup)
2781 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2782 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2784 if (use_lookup < 0)
2785 use_lookup = !!getenv("GIT_USE_LOOKUP");
2786 if (use_lookup) {
2787 int pos = sha1_entry_pos(index, stride, 0,
2788 lo, hi, p->num_objects, sha1);
2789 if (pos < 0)
2790 return 0;
2791 return nth_packed_object_offset(p, pos);
2794 do {
2795 unsigned mi = (lo + hi) / 2;
2796 int cmp = hashcmp(index + mi * stride, sha1);
2798 if (debug_lookup)
2799 printf("lo %u hi %u rg %u mi %u\n",
2800 lo, hi, hi - lo, mi);
2801 if (!cmp)
2802 return nth_packed_object_offset(p, mi);
2803 if (cmp > 0)
2804 hi = mi;
2805 else
2806 lo = mi+1;
2807 } while (lo < hi);
2808 return 0;
2811 int is_pack_valid(struct packed_git *p)
2813 /* An already open pack is known to be valid. */
2814 if (p->pack_fd != -1)
2815 return 1;
2817 /* If the pack has one window completely covering the
2818 * file size, the pack is known to be valid even if
2819 * the descriptor is not currently open.
2821 if (p->windows) {
2822 struct pack_window *w = p->windows;
2824 if (!w->offset && w->len == p->pack_size)
2825 return 1;
2828 /* Force the pack to open to prove its valid. */
2829 return !open_packed_git(p);
2832 static int fill_pack_entry(const unsigned char *sha1,
2833 struct pack_entry *e,
2834 struct packed_git *p)
2836 off_t offset;
2838 if (p->num_bad_objects) {
2839 unsigned i;
2840 for (i = 0; i < p->num_bad_objects; i++)
2841 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2842 return 0;
2845 offset = find_pack_entry_one(sha1, p);
2846 if (!offset)
2847 return 0;
2850 * We are about to tell the caller where they can locate the
2851 * requested object. We better make sure the packfile is
2852 * still here and can be accessed before supplying that
2853 * answer, as it may have been deleted since the index was
2854 * loaded!
2856 if (!is_pack_valid(p))
2857 return 0;
2858 e->offset = offset;
2859 e->p = p;
2860 hashcpy(e->sha1, sha1);
2861 return 1;
2865 * Iff a pack file contains the object named by sha1, return true and
2866 * store its location to e.
2868 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2870 struct mru_entry *p;
2872 prepare_packed_git();
2873 if (!packed_git)
2874 return 0;
2876 for (p = packed_git_mru->head; p; p = p->next) {
2877 if (fill_pack_entry(sha1, e, p->item)) {
2878 mru_mark(packed_git_mru, p);
2879 return 1;
2882 return 0;
2885 struct packed_git *find_sha1_pack(const unsigned char *sha1,
2886 struct packed_git *packs)
2888 struct packed_git *p;
2890 for (p = packs; p; p = p->next) {
2891 if (find_pack_entry_one(sha1, p))
2892 return p;
2894 return NULL;
2898 static int sha1_loose_object_info(const unsigned char *sha1,
2899 struct object_info *oi,
2900 int flags)
2902 int status = 0;
2903 unsigned long mapsize;
2904 void *map;
2905 git_zstream stream;
2906 char hdr[32];
2907 struct strbuf hdrbuf = STRBUF_INIT;
2909 if (oi->delta_base_sha1)
2910 hashclr(oi->delta_base_sha1);
2913 * If we don't care about type or size, then we don't
2914 * need to look inside the object at all. Note that we
2915 * do not optimize out the stat call, even if the
2916 * caller doesn't care about the disk-size, since our
2917 * return value implicitly indicates whether the
2918 * object even exists.
2920 if (!oi->typep && !oi->typename && !oi->sizep) {
2921 const char *path;
2922 struct stat st;
2923 if (stat_sha1_file(sha1, &st, &path) < 0)
2924 return -1;
2925 if (oi->disk_sizep)
2926 *oi->disk_sizep = st.st_size;
2927 return 0;
2930 map = map_sha1_file(sha1, &mapsize);
2931 if (!map)
2932 return -1;
2933 if (oi->disk_sizep)
2934 *oi->disk_sizep = mapsize;
2935 if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
2936 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2937 status = error("unable to unpack %s header with --allow-unknown-type",
2938 sha1_to_hex(sha1));
2939 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2940 status = error("unable to unpack %s header",
2941 sha1_to_hex(sha1));
2942 if (status < 0)
2943 ; /* Do nothing */
2944 else if (hdrbuf.len) {
2945 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2946 status = error("unable to parse %s header with --allow-unknown-type",
2947 sha1_to_hex(sha1));
2948 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
2949 status = error("unable to parse %s header", sha1_to_hex(sha1));
2950 git_inflate_end(&stream);
2951 munmap(map, mapsize);
2952 if (status && oi->typep)
2953 *oi->typep = status;
2954 strbuf_release(&hdrbuf);
2955 return (status < 0) ? status : 0;
2958 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
2960 struct cached_object *co;
2961 struct pack_entry e;
2962 int rtype;
2963 enum object_type real_type;
2964 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
2966 co = find_cached_object(real);
2967 if (co) {
2968 if (oi->typep)
2969 *(oi->typep) = co->type;
2970 if (oi->sizep)
2971 *(oi->sizep) = co->size;
2972 if (oi->disk_sizep)
2973 *(oi->disk_sizep) = 0;
2974 if (oi->delta_base_sha1)
2975 hashclr(oi->delta_base_sha1);
2976 if (oi->typename)
2977 strbuf_addstr(oi->typename, typename(co->type));
2978 oi->whence = OI_CACHED;
2979 return 0;
2982 if (!find_pack_entry(real, &e)) {
2983 /* Most likely it's a loose object. */
2984 if (!sha1_loose_object_info(real, oi, flags)) {
2985 oi->whence = OI_LOOSE;
2986 return 0;
2989 /* Not a loose object; someone else may have just packed it. */
2990 reprepare_packed_git();
2991 if (!find_pack_entry(real, &e))
2992 return -1;
2996 * packed_object_info() does not follow the delta chain to
2997 * find out the real type, unless it is given oi->typep.
2999 if (oi->typename && !oi->typep)
3000 oi->typep = &real_type;
3002 rtype = packed_object_info(e.p, e.offset, oi);
3003 if (rtype < 0) {
3004 mark_bad_packed_object(e.p, real);
3005 if (oi->typep == &real_type)
3006 oi->typep = NULL;
3007 return sha1_object_info_extended(real, oi, 0);
3008 } else if (in_delta_base_cache(e.p, e.offset)) {
3009 oi->whence = OI_DBCACHED;
3010 } else {
3011 oi->whence = OI_PACKED;
3012 oi->u.packed.offset = e.offset;
3013 oi->u.packed.pack = e.p;
3014 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
3015 rtype == OBJ_OFS_DELTA);
3017 if (oi->typename)
3018 strbuf_addstr(oi->typename, typename(*oi->typep));
3019 if (oi->typep == &real_type)
3020 oi->typep = NULL;
3022 return 0;
3025 /* returns enum object_type or negative */
3026 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
3028 enum object_type type;
3029 struct object_info oi = OBJECT_INFO_INIT;
3031 oi.typep = &type;
3032 oi.sizep = sizep;
3033 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
3034 return -1;
3035 return type;
3038 static void *read_packed_sha1(const unsigned char *sha1,
3039 enum object_type *type, unsigned long *size)
3041 struct pack_entry e;
3042 void *data;
3044 if (!find_pack_entry(sha1, &e))
3045 return NULL;
3046 data = cache_or_unpack_entry(e.p, e.offset, size, type);
3047 if (!data) {
3049 * We're probably in deep shit, but let's try to fetch
3050 * the required object anyway from another pack or loose.
3051 * This should happen only in the presence of a corrupted
3052 * pack, and is better than failing outright.
3054 error("failed to read object %s at offset %"PRIuMAX" from %s",
3055 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
3056 mark_bad_packed_object(e.p, sha1);
3057 data = read_object(sha1, type, size);
3059 return data;
3062 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
3063 unsigned char *sha1)
3065 struct cached_object *co;
3067 hash_sha1_file(buf, len, typename(type), sha1);
3068 if (has_sha1_file(sha1) || find_cached_object(sha1))
3069 return 0;
3070 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
3071 co = &cached_objects[cached_object_nr++];
3072 co->size = len;
3073 co->type = type;
3074 co->buf = xmalloc(len);
3075 memcpy(co->buf, buf, len);
3076 hashcpy(co->sha1, sha1);
3077 return 0;
3080 static void *read_object(const unsigned char *sha1, enum object_type *type,
3081 unsigned long *size)
3083 unsigned long mapsize;
3084 void *map, *buf;
3085 struct cached_object *co;
3087 co = find_cached_object(sha1);
3088 if (co) {
3089 *type = co->type;
3090 *size = co->size;
3091 return xmemdupz(co->buf, co->size);
3094 buf = read_packed_sha1(sha1, type, size);
3095 if (buf)
3096 return buf;
3097 map = map_sha1_file(sha1, &mapsize);
3098 if (map) {
3099 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
3100 munmap(map, mapsize);
3101 return buf;
3103 reprepare_packed_git();
3104 return read_packed_sha1(sha1, type, size);
3108 * This function dies on corrupt objects; the callers who want to
3109 * deal with them should arrange to call read_object() and give error
3110 * messages themselves.
3112 void *read_sha1_file_extended(const unsigned char *sha1,
3113 enum object_type *type,
3114 unsigned long *size,
3115 unsigned flag)
3117 void *data;
3118 const struct packed_git *p;
3119 const char *path;
3120 struct stat st;
3121 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
3123 errno = 0;
3124 data = read_object(repl, type, size);
3125 if (data)
3126 return data;
3128 if (errno && errno != ENOENT)
3129 die_errno("failed to read object %s", sha1_to_hex(sha1));
3131 /* die if we replaced an object with one that does not exist */
3132 if (repl != sha1)
3133 die("replacement %s not found for %s",
3134 sha1_to_hex(repl), sha1_to_hex(sha1));
3136 if (!stat_sha1_file(repl, &st, &path))
3137 die("loose object %s (stored in %s) is corrupt",
3138 sha1_to_hex(repl), path);
3140 if ((p = has_packed_and_bad(repl)) != NULL)
3141 die("packed object %s (stored in %s) is corrupt",
3142 sha1_to_hex(repl), p->pack_name);
3144 return NULL;
3147 void *read_object_with_reference(const unsigned char *sha1,
3148 const char *required_type_name,
3149 unsigned long *size,
3150 unsigned char *actual_sha1_return)
3152 enum object_type type, required_type;
3153 void *buffer;
3154 unsigned long isize;
3155 unsigned char actual_sha1[20];
3157 required_type = type_from_string(required_type_name);
3158 hashcpy(actual_sha1, sha1);
3159 while (1) {
3160 int ref_length = -1;
3161 const char *ref_type = NULL;
3163 buffer = read_sha1_file(actual_sha1, &type, &isize);
3164 if (!buffer)
3165 return NULL;
3166 if (type == required_type) {
3167 *size = isize;
3168 if (actual_sha1_return)
3169 hashcpy(actual_sha1_return, actual_sha1);
3170 return buffer;
3172 /* Handle references */
3173 else if (type == OBJ_COMMIT)
3174 ref_type = "tree ";
3175 else if (type == OBJ_TAG)
3176 ref_type = "object ";
3177 else {
3178 free(buffer);
3179 return NULL;
3181 ref_length = strlen(ref_type);
3183 if (ref_length + 40 > isize ||
3184 memcmp(buffer, ref_type, ref_length) ||
3185 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
3186 free(buffer);
3187 return NULL;
3189 free(buffer);
3190 /* Now we have the ID of the referred-to object in
3191 * actual_sha1. Check again. */
3195 static void write_sha1_file_prepare(const void *buf, unsigned long len,
3196 const char *type, unsigned char *sha1,
3197 char *hdr, int *hdrlen)
3199 git_SHA_CTX c;
3201 /* Generate the header */
3202 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
3204 /* Sha1.. */
3205 git_SHA1_Init(&c);
3206 git_SHA1_Update(&c, hdr, *hdrlen);
3207 git_SHA1_Update(&c, buf, len);
3208 git_SHA1_Final(sha1, &c);
3212 * Move the just written object into its final resting place.
3214 int finalize_object_file(const char *tmpfile, const char *filename)
3216 int ret = 0;
3218 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
3219 goto try_rename;
3220 else if (link(tmpfile, filename))
3221 ret = errno;
3224 * Coda hack - coda doesn't like cross-directory links,
3225 * so we fall back to a rename, which will mean that it
3226 * won't be able to check collisions, but that's not a
3227 * big deal.
3229 * The same holds for FAT formatted media.
3231 * When this succeeds, we just return. We have nothing
3232 * left to unlink.
3234 if (ret && ret != EEXIST) {
3235 try_rename:
3236 if (!rename(tmpfile, filename))
3237 goto out;
3238 ret = errno;
3240 unlink_or_warn(tmpfile);
3241 if (ret) {
3242 if (ret != EEXIST) {
3243 return error_errno("unable to write sha1 filename %s", filename);
3245 /* FIXME!!! Collision check here ? */
3248 out:
3249 if (adjust_shared_perm(filename))
3250 return error("unable to set permission to '%s'", filename);
3251 return 0;
3254 static int write_buffer(int fd, const void *buf, size_t len)
3256 if (write_in_full(fd, buf, len) < 0)
3257 return error_errno("file write error");
3258 return 0;
3261 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
3262 unsigned char *sha1)
3264 char hdr[32];
3265 int hdrlen = sizeof(hdr);
3266 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3267 return 0;
3270 /* Finalize a file on disk, and close it. */
3271 static void close_sha1_file(int fd)
3273 if (fsync_object_files)
3274 fsync_or_die(fd, "sha1 file");
3275 if (close(fd) != 0)
3276 die_errno("error when closing sha1 file");
3279 /* Size of directory component, including the ending '/' */
3280 static inline int directory_size(const char *filename)
3282 const char *s = strrchr(filename, '/');
3283 if (!s)
3284 return 0;
3285 return s - filename + 1;
3289 * This creates a temporary file in the same directory as the final
3290 * 'filename'
3292 * We want to avoid cross-directory filename renames, because those
3293 * can have problems on various filesystems (FAT, NFS, Coda).
3295 static int create_tmpfile(struct strbuf *tmp, const char *filename)
3297 int fd, dirlen = directory_size(filename);
3299 strbuf_reset(tmp);
3300 strbuf_add(tmp, filename, dirlen);
3301 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3302 fd = git_mkstemp_mode(tmp->buf, 0444);
3303 if (fd < 0 && dirlen && errno == ENOENT) {
3305 * Make sure the directory exists; note that the contents
3306 * of the buffer are undefined after mkstemp returns an
3307 * error, so we have to rewrite the whole buffer from
3308 * scratch.
3310 strbuf_reset(tmp);
3311 strbuf_add(tmp, filename, dirlen - 1);
3312 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
3313 return -1;
3314 if (adjust_shared_perm(tmp->buf))
3315 return -1;
3317 /* Try again */
3318 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3319 fd = git_mkstemp_mode(tmp->buf, 0444);
3321 return fd;
3324 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
3325 const void *buf, unsigned long len, time_t mtime)
3327 int fd, ret;
3328 unsigned char compressed[4096];
3329 git_zstream stream;
3330 git_SHA_CTX c;
3331 unsigned char parano_sha1[20];
3332 static struct strbuf tmp_file = STRBUF_INIT;
3333 const char *filename = sha1_file_name(sha1);
3335 fd = create_tmpfile(&tmp_file, filename);
3336 if (fd < 0) {
3337 if (errno == EACCES)
3338 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
3339 else
3340 return error_errno("unable to create temporary file");
3343 /* Set it up */
3344 git_deflate_init(&stream, zlib_compression_level);
3345 stream.next_out = compressed;
3346 stream.avail_out = sizeof(compressed);
3347 git_SHA1_Init(&c);
3349 /* First header.. */
3350 stream.next_in = (unsigned char *)hdr;
3351 stream.avail_in = hdrlen;
3352 while (git_deflate(&stream, 0) == Z_OK)
3353 ; /* nothing */
3354 git_SHA1_Update(&c, hdr, hdrlen);
3356 /* Then the data itself.. */
3357 stream.next_in = (void *)buf;
3358 stream.avail_in = len;
3359 do {
3360 unsigned char *in0 = stream.next_in;
3361 ret = git_deflate(&stream, Z_FINISH);
3362 git_SHA1_Update(&c, in0, stream.next_in - in0);
3363 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3364 die("unable to write sha1 file");
3365 stream.next_out = compressed;
3366 stream.avail_out = sizeof(compressed);
3367 } while (ret == Z_OK);
3369 if (ret != Z_STREAM_END)
3370 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
3371 ret = git_deflate_end_gently(&stream);
3372 if (ret != Z_OK)
3373 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
3374 git_SHA1_Final(parano_sha1, &c);
3375 if (hashcmp(sha1, parano_sha1) != 0)
3376 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
3378 close_sha1_file(fd);
3380 if (mtime) {
3381 struct utimbuf utb;
3382 utb.actime = mtime;
3383 utb.modtime = mtime;
3384 if (utime(tmp_file.buf, &utb) < 0)
3385 warning_errno("failed utime() on %s", tmp_file.buf);
3388 return finalize_object_file(tmp_file.buf, filename);
3391 static int freshen_loose_object(const unsigned char *sha1)
3393 return check_and_freshen(sha1, 1);
3396 static int freshen_packed_object(const unsigned char *sha1)
3398 struct pack_entry e;
3399 if (!find_pack_entry(sha1, &e))
3400 return 0;
3401 if (e.p->freshened)
3402 return 1;
3403 if (!freshen_file(e.p->pack_name))
3404 return 0;
3405 e.p->freshened = 1;
3406 return 1;
3409 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
3411 char hdr[32];
3412 int hdrlen = sizeof(hdr);
3414 /* Normally if we have it in the pack then we do not bother writing
3415 * it out into .git/objects/??/?{38} file.
3417 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3418 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3419 return 0;
3420 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3423 int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3424 unsigned char *sha1, unsigned flags)
3426 char *header;
3427 int hdrlen, status = 0;
3429 /* type string, SP, %lu of the length plus NUL must fit this */
3430 hdrlen = strlen(type) + 32;
3431 header = xmalloc(hdrlen);
3432 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3434 if (!(flags & HASH_WRITE_OBJECT))
3435 goto cleanup;
3436 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3437 goto cleanup;
3438 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3440 cleanup:
3441 free(header);
3442 return status;
3445 int force_object_loose(const unsigned char *sha1, time_t mtime)
3447 void *buf;
3448 unsigned long len;
3449 enum object_type type;
3450 char hdr[32];
3451 int hdrlen;
3452 int ret;
3454 if (has_loose_object(sha1))
3455 return 0;
3456 buf = read_packed_sha1(sha1, &type, &len);
3457 if (!buf)
3458 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
3459 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
3460 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3461 free(buf);
3463 return ret;
3466 int has_pack_index(const unsigned char *sha1)
3468 struct stat st;
3469 if (stat(sha1_pack_index_name(sha1), &st))
3470 return 0;
3471 return 1;
3474 int has_sha1_pack(const unsigned char *sha1)
3476 struct pack_entry e;
3477 return find_pack_entry(sha1, &e);
3480 int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
3482 struct pack_entry e;
3484 if (!startup_info->have_repository)
3485 return 0;
3486 if (find_pack_entry(sha1, &e))
3487 return 1;
3488 if (has_loose_object(sha1))
3489 return 1;
3490 if (flags & HAS_SHA1_QUICK)
3491 return 0;
3492 reprepare_packed_git();
3493 return find_pack_entry(sha1, &e);
3496 int has_object_file(const struct object_id *oid)
3498 return has_sha1_file(oid->hash);
3501 int has_object_file_with_flags(const struct object_id *oid, int flags)
3503 return has_sha1_file_with_flags(oid->hash, flags);
3506 static void check_tree(const void *buf, size_t size)
3508 struct tree_desc desc;
3509 struct name_entry entry;
3511 init_tree_desc(&desc, buf, size);
3512 while (tree_entry(&desc, &entry))
3513 /* do nothing
3514 * tree_entry() will die() on malformed entries */
3518 static void check_commit(const void *buf, size_t size)
3520 struct commit c;
3521 memset(&c, 0, sizeof(c));
3522 if (parse_commit_buffer(&c, buf, size))
3523 die("corrupt commit");
3526 static void check_tag(const void *buf, size_t size)
3528 struct tag t;
3529 memset(&t, 0, sizeof(t));
3530 if (parse_tag_buffer(&t, buf, size))
3531 die("corrupt tag");
3534 static int index_mem(unsigned char *sha1, void *buf, size_t size,
3535 enum object_type type,
3536 const char *path, unsigned flags)
3538 int ret, re_allocated = 0;
3539 int write_object = flags & HASH_WRITE_OBJECT;
3541 if (!type)
3542 type = OBJ_BLOB;
3545 * Convert blobs to git internal format
3547 if ((type == OBJ_BLOB) && path) {
3548 struct strbuf nbuf = STRBUF_INIT;
3549 if (convert_to_git(path, buf, size, &nbuf,
3550 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
3551 buf = strbuf_detach(&nbuf, &size);
3552 re_allocated = 1;
3555 if (flags & HASH_FORMAT_CHECK) {
3556 if (type == OBJ_TREE)
3557 check_tree(buf, size);
3558 if (type == OBJ_COMMIT)
3559 check_commit(buf, size);
3560 if (type == OBJ_TAG)
3561 check_tag(buf, size);
3564 if (write_object)
3565 ret = write_sha1_file(buf, size, typename(type), sha1);
3566 else
3567 ret = hash_sha1_file(buf, size, typename(type), sha1);
3568 if (re_allocated)
3569 free(buf);
3570 return ret;
3573 static int index_stream_convert_blob(unsigned char *sha1, int fd,
3574 const char *path, unsigned flags)
3576 int ret;
3577 const int write_object = flags & HASH_WRITE_OBJECT;
3578 struct strbuf sbuf = STRBUF_INIT;
3580 assert(path);
3581 assert(would_convert_to_git_filter_fd(path));
3583 convert_to_git_filter_fd(path, fd, &sbuf,
3584 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3586 if (write_object)
3587 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3588 sha1);
3589 else
3590 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3591 sha1);
3592 strbuf_release(&sbuf);
3593 return ret;
3596 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3597 const char *path, unsigned flags)
3599 struct strbuf sbuf = STRBUF_INIT;
3600 int ret;
3602 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3603 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3604 else
3605 ret = -1;
3606 strbuf_release(&sbuf);
3607 return ret;
3610 #define SMALL_FILE_SIZE (32*1024)
3612 static int index_core(unsigned char *sha1, int fd, size_t size,
3613 enum object_type type, const char *path,
3614 unsigned flags)
3616 int ret;
3618 if (!size) {
3619 ret = index_mem(sha1, "", size, type, path, flags);
3620 } else if (size <= SMALL_FILE_SIZE) {
3621 char *buf = xmalloc(size);
3622 if (size == read_in_full(fd, buf, size))
3623 ret = index_mem(sha1, buf, size, type, path, flags);
3624 else
3625 ret = error_errno("short read");
3626 free(buf);
3627 } else {
3628 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3629 ret = index_mem(sha1, buf, size, type, path, flags);
3630 munmap(buf, size);
3632 return ret;
3636 * This creates one packfile per large blob unless bulk-checkin
3637 * machinery is "plugged".
3639 * This also bypasses the usual "convert-to-git" dance, and that is on
3640 * purpose. We could write a streaming version of the converting
3641 * functions and insert that before feeding the data to fast-import
3642 * (or equivalent in-core API described above). However, that is
3643 * somewhat complicated, as we do not know the size of the filter
3644 * result, which we need to know beforehand when writing a git object.
3645 * Since the primary motivation for trying to stream from the working
3646 * tree file and to avoid mmaping it in core is to deal with large
3647 * binary blobs, they generally do not want to get any conversion, and
3648 * callers should avoid this code path when filters are requested.
3650 static int index_stream(unsigned char *sha1, int fd, size_t size,
3651 enum object_type type, const char *path,
3652 unsigned flags)
3654 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3657 int index_fd(unsigned char *sha1, int fd, struct stat *st,
3658 enum object_type type, const char *path, unsigned flags)
3660 int ret;
3663 * Call xsize_t() only when needed to avoid potentially unnecessary
3664 * die() for large files.
3666 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3667 ret = index_stream_convert_blob(sha1, fd, path, flags);
3668 else if (!S_ISREG(st->st_mode))
3669 ret = index_pipe(sha1, fd, type, path, flags);
3670 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
3671 (path && would_convert_to_git(path)))
3672 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3673 flags);
3674 else
3675 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3676 flags);
3677 close(fd);
3678 return ret;
3681 int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3683 int fd;
3684 struct strbuf sb = STRBUF_INIT;
3686 switch (st->st_mode & S_IFMT) {
3687 case S_IFREG:
3688 fd = open(path, O_RDONLY);
3689 if (fd < 0)
3690 return error_errno("open(\"%s\")", path);
3691 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3692 return error("%s: failed to insert into database",
3693 path);
3694 break;
3695 case S_IFLNK:
3696 if (strbuf_readlink(&sb, path, st->st_size))
3697 return error_errno("readlink(\"%s\")", path);
3698 if (!(flags & HASH_WRITE_OBJECT))
3699 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3700 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3701 return error("%s: failed to insert into database",
3702 path);
3703 strbuf_release(&sb);
3704 break;
3705 case S_IFDIR:
3706 return resolve_gitlink_ref(path, "HEAD", sha1);
3707 default:
3708 return error("%s: unsupported file type", path);
3710 return 0;
3713 int read_pack_header(int fd, struct pack_header *header)
3715 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3716 /* "eof before pack header was fully read" */
3717 return PH_ERROR_EOF;
3719 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3720 /* "protocol error (pack signature mismatch detected)" */
3721 return PH_ERROR_PACK_SIGNATURE;
3722 if (!pack_version_ok(header->hdr_version))
3723 /* "protocol error (pack version unsupported)" */
3724 return PH_ERROR_PROTOCOL;
3725 return 0;
3728 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3730 enum object_type type = sha1_object_info(sha1, NULL);
3731 if (type < 0)
3732 die("%s is not a valid object", sha1_to_hex(sha1));
3733 if (type != expect)
3734 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3735 typename(expect));
3738 static int for_each_file_in_obj_subdir(int subdir_nr,
3739 struct strbuf *path,
3740 each_loose_object_fn obj_cb,
3741 each_loose_cruft_fn cruft_cb,
3742 each_loose_subdir_fn subdir_cb,
3743 void *data)
3745 size_t baselen = path->len;
3746 DIR *dir = opendir(path->buf);
3747 struct dirent *de;
3748 int r = 0;
3750 if (!dir) {
3751 if (errno == ENOENT)
3752 return 0;
3753 return error_errno("unable to open %s", path->buf);
3756 while ((de = readdir(dir))) {
3757 if (is_dot_or_dotdot(de->d_name))
3758 continue;
3760 strbuf_setlen(path, baselen);
3761 strbuf_addf(path, "/%s", de->d_name);
3763 if (strlen(de->d_name) == GIT_SHA1_HEXSZ - 2) {
3764 char hex[GIT_MAX_HEXSZ+1];
3765 struct object_id oid;
3767 xsnprintf(hex, sizeof(hex), "%02x%s",
3768 subdir_nr, de->d_name);
3769 if (!get_oid_hex(hex, &oid)) {
3770 if (obj_cb) {
3771 r = obj_cb(&oid, path->buf, data);
3772 if (r)
3773 break;
3775 continue;
3779 if (cruft_cb) {
3780 r = cruft_cb(de->d_name, path->buf, data);
3781 if (r)
3782 break;
3785 closedir(dir);
3787 strbuf_setlen(path, baselen);
3788 if (!r && subdir_cb)
3789 r = subdir_cb(subdir_nr, path->buf, data);
3791 return r;
3794 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
3795 each_loose_object_fn obj_cb,
3796 each_loose_cruft_fn cruft_cb,
3797 each_loose_subdir_fn subdir_cb,
3798 void *data)
3800 size_t baselen = path->len;
3801 int r = 0;
3802 int i;
3804 for (i = 0; i < 256; i++) {
3805 strbuf_addf(path, "/%02x", i);
3806 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
3807 subdir_cb, data);
3808 strbuf_setlen(path, baselen);
3809 if (r)
3810 break;
3813 return r;
3816 int for_each_loose_file_in_objdir(const char *path,
3817 each_loose_object_fn obj_cb,
3818 each_loose_cruft_fn cruft_cb,
3819 each_loose_subdir_fn subdir_cb,
3820 void *data)
3822 struct strbuf buf = STRBUF_INIT;
3823 int r;
3825 strbuf_addstr(&buf, path);
3826 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
3827 subdir_cb, data);
3828 strbuf_release(&buf);
3830 return r;
3833 struct loose_alt_odb_data {
3834 each_loose_object_fn *cb;
3835 void *data;
3838 static int loose_from_alt_odb(struct alternate_object_database *alt,
3839 void *vdata)
3841 struct loose_alt_odb_data *data = vdata;
3842 struct strbuf buf = STRBUF_INIT;
3843 int r;
3845 strbuf_addstr(&buf, alt->path);
3846 r = for_each_loose_file_in_objdir_buf(&buf,
3847 data->cb, NULL, NULL,
3848 data->data);
3849 strbuf_release(&buf);
3850 return r;
3853 int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
3855 struct loose_alt_odb_data alt;
3856 int r;
3858 r = for_each_loose_file_in_objdir(get_object_directory(),
3859 cb, NULL, NULL, data);
3860 if (r)
3861 return r;
3863 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
3864 return 0;
3866 alt.cb = cb;
3867 alt.data = data;
3868 return foreach_alt_odb(loose_from_alt_odb, &alt);
3871 static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
3873 uint32_t i;
3874 int r = 0;
3876 for (i = 0; i < p->num_objects; i++) {
3877 struct object_id oid;
3879 if (!nth_packed_object_oid(&oid, p, i))
3880 return error("unable to get sha1 of object %u in %s",
3881 i, p->pack_name);
3883 r = cb(&oid, p, i, data);
3884 if (r)
3885 break;
3887 return r;
3890 int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
3892 struct packed_git *p;
3893 int r = 0;
3894 int pack_errors = 0;
3896 prepare_packed_git();
3897 for (p = packed_git; p; p = p->next) {
3898 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
3899 continue;
3900 if (open_pack_index(p)) {
3901 pack_errors = 1;
3902 continue;
3904 r = for_each_object_in_pack(p, cb, data);
3905 if (r)
3906 break;
3908 return r ? r : pack_errors;
3911 static int check_stream_sha1(git_zstream *stream,
3912 const char *hdr,
3913 unsigned long size,
3914 const char *path,
3915 const unsigned char *expected_sha1)
3917 git_SHA_CTX c;
3918 unsigned char real_sha1[GIT_MAX_RAWSZ];
3919 unsigned char buf[4096];
3920 unsigned long total_read;
3921 int status = Z_OK;
3923 git_SHA1_Init(&c);
3924 git_SHA1_Update(&c, hdr, stream->total_out);
3927 * We already read some bytes into hdr, but the ones up to the NUL
3928 * do not count against the object's content size.
3930 total_read = stream->total_out - strlen(hdr) - 1;
3933 * This size comparison must be "<=" to read the final zlib packets;
3934 * see the comment in unpack_sha1_rest for details.
3936 while (total_read <= size &&
3937 (status == Z_OK || status == Z_BUF_ERROR)) {
3938 stream->next_out = buf;
3939 stream->avail_out = sizeof(buf);
3940 if (size - total_read < stream->avail_out)
3941 stream->avail_out = size - total_read;
3942 status = git_inflate(stream, Z_FINISH);
3943 git_SHA1_Update(&c, buf, stream->next_out - buf);
3944 total_read += stream->next_out - buf;
3946 git_inflate_end(stream);
3948 if (status != Z_STREAM_END) {
3949 error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
3950 return -1;
3952 if (stream->avail_in) {
3953 error("garbage at end of loose object '%s'",
3954 sha1_to_hex(expected_sha1));
3955 return -1;
3958 git_SHA1_Final(real_sha1, &c);
3959 if (hashcmp(expected_sha1, real_sha1)) {
3960 error("sha1 mismatch for %s (expected %s)", path,
3961 sha1_to_hex(expected_sha1));
3962 return -1;
3965 return 0;
3968 int read_loose_object(const char *path,
3969 const unsigned char *expected_sha1,
3970 enum object_type *type,
3971 unsigned long *size,
3972 void **contents)
3974 int ret = -1;
3975 void *map = NULL;
3976 unsigned long mapsize;
3977 git_zstream stream;
3978 char hdr[32];
3980 *contents = NULL;
3982 map = map_sha1_file_1(path, NULL, &mapsize);
3983 if (!map) {
3984 error_errno("unable to mmap %s", path);
3985 goto out;
3988 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
3989 error("unable to unpack header of %s", path);
3990 goto out;
3993 *type = parse_sha1_header(hdr, size);
3994 if (*type < 0) {
3995 error("unable to parse header of %s", path);
3996 git_inflate_end(&stream);
3997 goto out;
4000 if (*type == OBJ_BLOB) {
4001 if (check_stream_sha1(&stream, hdr, *size, path, expected_sha1) < 0)
4002 goto out;
4003 } else {
4004 *contents = unpack_sha1_rest(&stream, hdr, *size, expected_sha1);
4005 if (!*conten