t6300: abstract away SHA-1-specific constants
[git/raj.git] / sha1-file.c
blobc36ca5a545542dc53f2bafa072b1cb689f0700f8
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "config.h"
11 #include "string-list.h"
12 #include "lockfile.h"
13 #include "delta.h"
14 #include "pack.h"
15 #include "blob.h"
16 #include "commit.h"
17 #include "run-command.h"
18 #include "tag.h"
19 #include "tree.h"
20 #include "tree-walk.h"
21 #include "refs.h"
22 #include "pack-revindex.h"
23 #include "sha1-lookup.h"
24 #include "bulk-checkin.h"
25 #include "repository.h"
26 #include "replace-object.h"
27 #include "streaming.h"
28 #include "dir.h"
29 #include "list.h"
30 #include "mergesort.h"
31 #include "quote.h"
32 #include "packfile.h"
33 #include "object-store.h"
34 #include "promisor-remote.h"
36 /* The maximum size for an object header. */
37 #define MAX_HEADER_LEN 32
40 #define EMPTY_TREE_SHA1_BIN_LITERAL \
41 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
42 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
43 #define EMPTY_TREE_SHA256_BIN_LITERAL \
44 "\x6e\xf1\x9b\x41\x22\x5c\x53\x69\xf1\xc1" \
45 "\x04\xd4\x5d\x8d\x85\xef\xa9\xb0\x57\xb5" \
46 "\x3b\x14\xb4\xb9\xb9\x39\xdd\x74\xde\xcc" \
47 "\x53\x21"
49 #define EMPTY_BLOB_SHA1_BIN_LITERAL \
50 "\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
51 "\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
52 #define EMPTY_BLOB_SHA256_BIN_LITERAL \
53 "\x47\x3a\x0f\x4c\x3b\xe8\xa9\x36\x81\xa2" \
54 "\x67\xe3\xb1\xe9\xa7\xdc\xda\x11\x85\x43" \
55 "\x6f\xe1\x41\xf7\x74\x91\x20\xa3\x03\x72" \
56 "\x18\x13"
58 const struct object_id null_oid;
59 static const struct object_id empty_tree_oid = {
60 EMPTY_TREE_SHA1_BIN_LITERAL
62 static const struct object_id empty_blob_oid = {
63 EMPTY_BLOB_SHA1_BIN_LITERAL
65 static const struct object_id empty_tree_oid_sha256 = {
66 EMPTY_TREE_SHA256_BIN_LITERAL
68 static const struct object_id empty_blob_oid_sha256 = {
69 EMPTY_BLOB_SHA256_BIN_LITERAL
72 static void git_hash_sha1_init(git_hash_ctx *ctx)
74 git_SHA1_Init(&ctx->sha1);
77 static void git_hash_sha1_clone(git_hash_ctx *dst, const git_hash_ctx *src)
79 git_SHA1_Clone(&dst->sha1, &src->sha1);
82 static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
84 git_SHA1_Update(&ctx->sha1, data, len);
87 static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
89 git_SHA1_Final(hash, &ctx->sha1);
93 static void git_hash_sha256_init(git_hash_ctx *ctx)
95 git_SHA256_Init(&ctx->sha256);
98 static void git_hash_sha256_clone(git_hash_ctx *dst, const git_hash_ctx *src)
100 git_SHA256_Clone(&dst->sha256, &src->sha256);
103 static void git_hash_sha256_update(git_hash_ctx *ctx, const void *data, size_t len)
105 git_SHA256_Update(&ctx->sha256, data, len);
108 static void git_hash_sha256_final(unsigned char *hash, git_hash_ctx *ctx)
110 git_SHA256_Final(hash, &ctx->sha256);
113 static void git_hash_unknown_init(git_hash_ctx *ctx)
115 BUG("trying to init unknown hash");
118 static void git_hash_unknown_clone(git_hash_ctx *dst, const git_hash_ctx *src)
120 BUG("trying to clone unknown hash");
123 static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
125 BUG("trying to update unknown hash");
128 static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
130 BUG("trying to finalize unknown hash");
133 const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
135 NULL,
136 0x00000000,
140 git_hash_unknown_init,
141 git_hash_unknown_clone,
142 git_hash_unknown_update,
143 git_hash_unknown_final,
144 NULL,
145 NULL,
148 "sha1",
149 /* "sha1", big-endian */
150 0x73686131,
151 GIT_SHA1_RAWSZ,
152 GIT_SHA1_HEXSZ,
153 GIT_SHA1_BLKSZ,
154 git_hash_sha1_init,
155 git_hash_sha1_clone,
156 git_hash_sha1_update,
157 git_hash_sha1_final,
158 &empty_tree_oid,
159 &empty_blob_oid,
162 "sha256",
163 /* "s256", big-endian */
164 0x73323536,
165 GIT_SHA256_RAWSZ,
166 GIT_SHA256_HEXSZ,
167 GIT_SHA256_BLKSZ,
168 git_hash_sha256_init,
169 git_hash_sha256_clone,
170 git_hash_sha256_update,
171 git_hash_sha256_final,
172 &empty_tree_oid_sha256,
173 &empty_blob_oid_sha256,
177 const char *empty_tree_oid_hex(void)
179 static char buf[GIT_MAX_HEXSZ + 1];
180 return oid_to_hex_r(buf, the_hash_algo->empty_tree);
183 const char *empty_blob_oid_hex(void)
185 static char buf[GIT_MAX_HEXSZ + 1];
186 return oid_to_hex_r(buf, the_hash_algo->empty_blob);
189 int hash_algo_by_name(const char *name)
191 int i;
192 if (!name)
193 return GIT_HASH_UNKNOWN;
194 for (i = 1; i < GIT_HASH_NALGOS; i++)
195 if (!strcmp(name, hash_algos[i].name))
196 return i;
197 return GIT_HASH_UNKNOWN;
200 int hash_algo_by_id(uint32_t format_id)
202 int i;
203 for (i = 1; i < GIT_HASH_NALGOS; i++)
204 if (format_id == hash_algos[i].format_id)
205 return i;
206 return GIT_HASH_UNKNOWN;
209 int hash_algo_by_length(int len)
211 int i;
212 for (i = 1; i < GIT_HASH_NALGOS; i++)
213 if (len == hash_algos[i].rawsz)
214 return i;
215 return GIT_HASH_UNKNOWN;
219 * This is meant to hold a *small* number of objects that you would
220 * want read_object_file() to be able to return, but yet you do not want
221 * to write them into the object store (e.g. a browse-only
222 * application).
224 static struct cached_object {
225 struct object_id oid;
226 enum object_type type;
227 void *buf;
228 unsigned long size;
229 } *cached_objects;
230 static int cached_object_nr, cached_object_alloc;
232 static struct cached_object empty_tree = {
233 { EMPTY_TREE_SHA1_BIN_LITERAL },
234 OBJ_TREE,
239 static struct cached_object *find_cached_object(const struct object_id *oid)
241 int i;
242 struct cached_object *co = cached_objects;
244 for (i = 0; i < cached_object_nr; i++, co++) {
245 if (oideq(&co->oid, oid))
246 return co;
248 if (oideq(oid, the_hash_algo->empty_tree))
249 return &empty_tree;
250 return NULL;
254 static int get_conv_flags(unsigned flags)
256 if (flags & HASH_RENORMALIZE)
257 return CONV_EOL_RENORMALIZE;
258 else if (flags & HASH_WRITE_OBJECT)
259 return global_conv_flags_eol | CONV_WRITE_OBJECT;
260 else
261 return 0;
265 int mkdir_in_gitdir(const char *path)
267 if (mkdir(path, 0777)) {
268 int saved_errno = errno;
269 struct stat st;
270 struct strbuf sb = STRBUF_INIT;
272 if (errno != EEXIST)
273 return -1;
275 * Are we looking at a path in a symlinked worktree
276 * whose original repository does not yet have it?
277 * e.g. .git/rr-cache pointing at its original
278 * repository in which the user hasn't performed any
279 * conflict resolution yet?
281 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
282 strbuf_readlink(&sb, path, st.st_size) ||
283 !is_absolute_path(sb.buf) ||
284 mkdir(sb.buf, 0777)) {
285 strbuf_release(&sb);
286 errno = saved_errno;
287 return -1;
289 strbuf_release(&sb);
291 return adjust_shared_perm(path);
294 enum scld_error safe_create_leading_directories(char *path)
296 char *next_component = path + offset_1st_component(path);
297 enum scld_error ret = SCLD_OK;
299 while (ret == SCLD_OK && next_component) {
300 struct stat st;
301 char *slash = next_component, slash_character;
303 while (*slash && !is_dir_sep(*slash))
304 slash++;
306 if (!*slash)
307 break;
309 next_component = slash + 1;
310 while (is_dir_sep(*next_component))
311 next_component++;
312 if (!*next_component)
313 break;
315 slash_character = *slash;
316 *slash = '\0';
317 if (!stat(path, &st)) {
318 /* path exists */
319 if (!S_ISDIR(st.st_mode)) {
320 errno = ENOTDIR;
321 ret = SCLD_EXISTS;
323 } else if (mkdir(path, 0777)) {
324 if (errno == EEXIST &&
325 !stat(path, &st) && S_ISDIR(st.st_mode))
326 ; /* somebody created it since we checked */
327 else if (errno == ENOENT)
329 * Either mkdir() failed because
330 * somebody just pruned the containing
331 * directory, or stat() failed because
332 * the file that was in our way was
333 * just removed. Either way, inform
334 * the caller that it might be worth
335 * trying again:
337 ret = SCLD_VANISHED;
338 else
339 ret = SCLD_FAILED;
340 } else if (adjust_shared_perm(path)) {
341 ret = SCLD_PERMS;
343 *slash = slash_character;
345 return ret;
348 enum scld_error safe_create_leading_directories_const(const char *path)
350 int save_errno;
351 /* path points to cache entries, so xstrdup before messing with it */
352 char *buf = xstrdup(path);
353 enum scld_error result = safe_create_leading_directories(buf);
355 save_errno = errno;
356 free(buf);
357 errno = save_errno;
358 return result;
361 int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
364 * The number of times we will try to remove empty directories
365 * in the way of path. This is only 1 because if another
366 * process is racily creating directories that conflict with
367 * us, we don't want to fight against them.
369 int remove_directories_remaining = 1;
372 * The number of times that we will try to create the
373 * directories containing path. We are willing to attempt this
374 * more than once, because another process could be trying to
375 * clean up empty directories at the same time as we are
376 * trying to create them.
378 int create_directories_remaining = 3;
380 /* A scratch copy of path, filled lazily if we need it: */
381 struct strbuf path_copy = STRBUF_INIT;
383 int ret, save_errno;
385 /* Sanity check: */
386 assert(*path);
388 retry_fn:
389 ret = fn(path, cb);
390 save_errno = errno;
391 if (!ret)
392 goto out;
394 if (errno == EISDIR && remove_directories_remaining-- > 0) {
396 * A directory is in the way. Maybe it is empty; try
397 * to remove it:
399 if (!path_copy.len)
400 strbuf_addstr(&path_copy, path);
402 if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
403 goto retry_fn;
404 } else if (errno == ENOENT && create_directories_remaining-- > 0) {
406 * Maybe the containing directory didn't exist, or
407 * maybe it was just deleted by a process that is
408 * racing with us to clean up empty directories. Try
409 * to create it:
411 enum scld_error scld_result;
413 if (!path_copy.len)
414 strbuf_addstr(&path_copy, path);
416 do {
417 scld_result = safe_create_leading_directories(path_copy.buf);
418 if (scld_result == SCLD_OK)
419 goto retry_fn;
420 } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
423 out:
424 strbuf_release(&path_copy);
425 errno = save_errno;
426 return ret;
429 static void fill_loose_path(struct strbuf *buf, const struct object_id *oid)
431 int i;
432 for (i = 0; i < the_hash_algo->rawsz; i++) {
433 static char hex[] = "0123456789abcdef";
434 unsigned int val = oid->hash[i];
435 strbuf_addch(buf, hex[val >> 4]);
436 strbuf_addch(buf, hex[val & 0xf]);
437 if (!i)
438 strbuf_addch(buf, '/');
442 static const char *odb_loose_path(struct object_directory *odb,
443 struct strbuf *buf,
444 const struct object_id *oid)
446 strbuf_reset(buf);
447 strbuf_addstr(buf, odb->path);
448 strbuf_addch(buf, '/');
449 fill_loose_path(buf, oid);
450 return buf->buf;
453 const char *loose_object_path(struct repository *r, struct strbuf *buf,
454 const struct object_id *oid)
456 return odb_loose_path(r->objects->odb, buf, oid);
460 * Return non-zero iff the path is usable as an alternate object database.
462 static int alt_odb_usable(struct raw_object_store *o,
463 struct strbuf *path,
464 const char *normalized_objdir)
466 struct object_directory *odb;
468 /* Detect cases where alternate disappeared */
469 if (!is_directory(path->buf)) {
470 error(_("object directory %s does not exist; "
471 "check .git/objects/info/alternates"),
472 path->buf);
473 return 0;
477 * Prevent the common mistake of listing the same
478 * thing twice, or object directory itself.
480 for (odb = o->odb; odb; odb = odb->next) {
481 if (!fspathcmp(path->buf, odb->path))
482 return 0;
484 if (!fspathcmp(path->buf, normalized_objdir))
485 return 0;
487 return 1;
491 * Prepare alternate object database registry.
493 * The variable alt_odb_list points at the list of struct
494 * object_directory. The elements on this list come from
495 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
496 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
497 * whose contents is similar to that environment variable but can be
498 * LF separated. Its base points at a statically allocated buffer that
499 * contains "/the/directory/corresponding/to/.git/objects/...", while
500 * its name points just after the slash at the end of ".git/objects/"
501 * in the example above, and has enough space to hold 40-byte hex
502 * SHA1, an extra slash for the first level indirection, and the
503 * terminating NUL.
505 static void read_info_alternates(struct repository *r,
506 const char *relative_base,
507 int depth);
508 static int link_alt_odb_entry(struct repository *r, const char *entry,
509 const char *relative_base, int depth, const char *normalized_objdir)
511 struct object_directory *ent;
512 struct strbuf pathbuf = STRBUF_INIT;
514 if (!is_absolute_path(entry) && relative_base) {
515 strbuf_realpath(&pathbuf, relative_base, 1);
516 strbuf_addch(&pathbuf, '/');
518 strbuf_addstr(&pathbuf, entry);
520 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
521 error(_("unable to normalize alternate object path: %s"),
522 pathbuf.buf);
523 strbuf_release(&pathbuf);
524 return -1;
528 * The trailing slash after the directory name is given by
529 * this function at the end. Remove duplicates.
531 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
532 strbuf_setlen(&pathbuf, pathbuf.len - 1);
534 if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir)) {
535 strbuf_release(&pathbuf);
536 return -1;
539 ent = xcalloc(1, sizeof(*ent));
540 ent->path = xstrdup(pathbuf.buf);
542 /* add the alternate entry */
543 *r->objects->odb_tail = ent;
544 r->objects->odb_tail = &(ent->next);
545 ent->next = NULL;
547 /* recursively add alternates */
548 read_info_alternates(r, pathbuf.buf, depth + 1);
550 strbuf_release(&pathbuf);
551 return 0;
554 static const char *parse_alt_odb_entry(const char *string,
555 int sep,
556 struct strbuf *out)
558 const char *end;
560 strbuf_reset(out);
562 if (*string == '#') {
563 /* comment; consume up to next separator */
564 end = strchrnul(string, sep);
565 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
567 * quoted path; unquote_c_style has copied the
568 * data for us and set "end". Broken quoting (e.g.,
569 * an entry that doesn't end with a quote) falls
570 * back to the unquoted case below.
572 } else {
573 /* normal, unquoted path */
574 end = strchrnul(string, sep);
575 strbuf_add(out, string, end - string);
578 if (*end)
579 end++;
580 return end;
583 static void link_alt_odb_entries(struct repository *r, const char *alt,
584 int sep, const char *relative_base, int depth)
586 struct strbuf objdirbuf = STRBUF_INIT;
587 struct strbuf entry = STRBUF_INIT;
589 if (!alt || !*alt)
590 return;
592 if (depth > 5) {
593 error(_("%s: ignoring alternate object stores, nesting too deep"),
594 relative_base);
595 return;
598 strbuf_add_absolute_path(&objdirbuf, r->objects->odb->path);
599 if (strbuf_normalize_path(&objdirbuf) < 0)
600 die(_("unable to normalize object directory: %s"),
601 objdirbuf.buf);
603 while (*alt) {
604 alt = parse_alt_odb_entry(alt, sep, &entry);
605 if (!entry.len)
606 continue;
607 link_alt_odb_entry(r, entry.buf,
608 relative_base, depth, objdirbuf.buf);
610 strbuf_release(&entry);
611 strbuf_release(&objdirbuf);
614 static void read_info_alternates(struct repository *r,
615 const char *relative_base,
616 int depth)
618 char *path;
619 struct strbuf buf = STRBUF_INIT;
621 path = xstrfmt("%s/info/alternates", relative_base);
622 if (strbuf_read_file(&buf, path, 1024) < 0) {
623 warn_on_fopen_errors(path);
624 free(path);
625 return;
628 link_alt_odb_entries(r, buf.buf, '\n', relative_base, depth);
629 strbuf_release(&buf);
630 free(path);
633 void add_to_alternates_file(const char *reference)
635 struct lock_file lock = LOCK_INIT;
636 char *alts = git_pathdup("objects/info/alternates");
637 FILE *in, *out;
638 int found = 0;
640 hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
641 out = fdopen_lock_file(&lock, "w");
642 if (!out)
643 die_errno(_("unable to fdopen alternates lockfile"));
645 in = fopen(alts, "r");
646 if (in) {
647 struct strbuf line = STRBUF_INIT;
649 while (strbuf_getline(&line, in) != EOF) {
650 if (!strcmp(reference, line.buf)) {
651 found = 1;
652 break;
654 fprintf_or_die(out, "%s\n", line.buf);
657 strbuf_release(&line);
658 fclose(in);
660 else if (errno != ENOENT)
661 die_errno(_("unable to read alternates file"));
663 if (found) {
664 rollback_lock_file(&lock);
665 } else {
666 fprintf_or_die(out, "%s\n", reference);
667 if (commit_lock_file(&lock))
668 die_errno(_("unable to move new alternates file into place"));
669 if (the_repository->objects->loaded_alternates)
670 link_alt_odb_entries(the_repository, reference,
671 '\n', NULL, 0);
673 free(alts);
676 void add_to_alternates_memory(const char *reference)
679 * Make sure alternates are initialized, or else our entry may be
680 * overwritten when they are.
682 prepare_alt_odb(the_repository);
684 link_alt_odb_entries(the_repository, reference,
685 '\n', NULL, 0);
689 * Compute the exact path an alternate is at and returns it. In case of
690 * error NULL is returned and the human readable error is added to `err`
691 * `path` may be relative and should point to $GIT_DIR.
692 * `err` must not be null.
694 char *compute_alternate_path(const char *path, struct strbuf *err)
696 char *ref_git = NULL;
697 const char *repo, *ref_git_s;
698 int seen_error = 0;
700 ref_git_s = real_path_if_valid(path);
701 if (!ref_git_s) {
702 seen_error = 1;
703 strbuf_addf(err, _("path '%s' does not exist"), path);
704 goto out;
705 } else
707 * Beware: read_gitfile(), real_path() and mkpath()
708 * return static buffer
710 ref_git = xstrdup(ref_git_s);
712 repo = read_gitfile(ref_git);
713 if (!repo)
714 repo = read_gitfile(mkpath("%s/.git", ref_git));
715 if (repo) {
716 free(ref_git);
717 ref_git = xstrdup(repo);
720 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
721 char *ref_git_git = mkpathdup("%s/.git", ref_git);
722 free(ref_git);
723 ref_git = ref_git_git;
724 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
725 struct strbuf sb = STRBUF_INIT;
726 seen_error = 1;
727 if (get_common_dir(&sb, ref_git)) {
728 strbuf_addf(err,
729 _("reference repository '%s' as a linked "
730 "checkout is not supported yet."),
731 path);
732 goto out;
735 strbuf_addf(err, _("reference repository '%s' is not a "
736 "local repository."), path);
737 goto out;
740 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
741 strbuf_addf(err, _("reference repository '%s' is shallow"),
742 path);
743 seen_error = 1;
744 goto out;
747 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
748 strbuf_addf(err,
749 _("reference repository '%s' is grafted"),
750 path);
751 seen_error = 1;
752 goto out;
755 out:
756 if (seen_error) {
757 FREE_AND_NULL(ref_git);
760 return ref_git;
763 static void fill_alternate_refs_command(struct child_process *cmd,
764 const char *repo_path)
766 const char *value;
768 if (!git_config_get_value("core.alternateRefsCommand", &value)) {
769 cmd->use_shell = 1;
771 argv_array_push(&cmd->args, value);
772 argv_array_push(&cmd->args, repo_path);
773 } else {
774 cmd->git_cmd = 1;
776 argv_array_pushf(&cmd->args, "--git-dir=%s", repo_path);
777 argv_array_push(&cmd->args, "for-each-ref");
778 argv_array_push(&cmd->args, "--format=%(objectname)");
780 if (!git_config_get_value("core.alternateRefsPrefixes", &value)) {
781 argv_array_push(&cmd->args, "--");
782 argv_array_split(&cmd->args, value);
786 cmd->env = local_repo_env;
787 cmd->out = -1;
790 static void read_alternate_refs(const char *path,
791 alternate_ref_fn *cb,
792 void *data)
794 struct child_process cmd = CHILD_PROCESS_INIT;
795 struct strbuf line = STRBUF_INIT;
796 FILE *fh;
798 fill_alternate_refs_command(&cmd, path);
800 if (start_command(&cmd))
801 return;
803 fh = xfdopen(cmd.out, "r");
804 while (strbuf_getline_lf(&line, fh) != EOF) {
805 struct object_id oid;
806 const char *p;
808 if (parse_oid_hex(line.buf, &oid, &p) || *p) {
809 warning(_("invalid line while parsing alternate refs: %s"),
810 line.buf);
811 break;
814 cb(&oid, data);
817 fclose(fh);
818 finish_command(&cmd);
819 strbuf_release(&line);
822 struct alternate_refs_data {
823 alternate_ref_fn *fn;
824 void *data;
827 static int refs_from_alternate_cb(struct object_directory *e,
828 void *data)
830 struct strbuf path = STRBUF_INIT;
831 size_t base_len;
832 struct alternate_refs_data *cb = data;
834 if (!strbuf_realpath(&path, e->path, 0))
835 goto out;
836 if (!strbuf_strip_suffix(&path, "/objects"))
837 goto out;
838 base_len = path.len;
840 /* Is this a git repository with refs? */
841 strbuf_addstr(&path, "/refs");
842 if (!is_directory(path.buf))
843 goto out;
844 strbuf_setlen(&path, base_len);
846 read_alternate_refs(path.buf, cb->fn, cb->data);
848 out:
849 strbuf_release(&path);
850 return 0;
853 void for_each_alternate_ref(alternate_ref_fn fn, void *data)
855 struct alternate_refs_data cb;
856 cb.fn = fn;
857 cb.data = data;
858 foreach_alt_odb(refs_from_alternate_cb, &cb);
861 int foreach_alt_odb(alt_odb_fn fn, void *cb)
863 struct object_directory *ent;
864 int r = 0;
866 prepare_alt_odb(the_repository);
867 for (ent = the_repository->objects->odb->next; ent; ent = ent->next) {
868 r = fn(ent, cb);
869 if (r)
870 break;
872 return r;
875 void prepare_alt_odb(struct repository *r)
877 if (r->objects->loaded_alternates)
878 return;
880 link_alt_odb_entries(r, r->objects->alternate_db, PATH_SEP, NULL, 0);
882 read_info_alternates(r, r->objects->odb->path, 0);
883 r->objects->loaded_alternates = 1;
886 /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
887 static int freshen_file(const char *fn)
889 struct utimbuf t;
890 t.actime = t.modtime = time(NULL);
891 return !utime(fn, &t);
895 * All of the check_and_freshen functions return 1 if the file exists and was
896 * freshened (if freshening was requested), 0 otherwise. If they return
897 * 0, you should not assume that it is safe to skip a write of the object (it
898 * either does not exist on disk, or has a stale mtime and may be subject to
899 * pruning).
901 int check_and_freshen_file(const char *fn, int freshen)
903 if (access(fn, F_OK))
904 return 0;
905 if (freshen && !freshen_file(fn))
906 return 0;
907 return 1;
910 static int check_and_freshen_odb(struct object_directory *odb,
911 const struct object_id *oid,
912 int freshen)
914 static struct strbuf path = STRBUF_INIT;
915 odb_loose_path(odb, &path, oid);
916 return check_and_freshen_file(path.buf, freshen);
919 static int check_and_freshen_local(const struct object_id *oid, int freshen)
921 return check_and_freshen_odb(the_repository->objects->odb, oid, freshen);
924 static int check_and_freshen_nonlocal(const struct object_id *oid, int freshen)
926 struct object_directory *odb;
928 prepare_alt_odb(the_repository);
929 for (odb = the_repository->objects->odb->next; odb; odb = odb->next) {
930 if (check_and_freshen_odb(odb, oid, freshen))
931 return 1;
933 return 0;
936 static int check_and_freshen(const struct object_id *oid, int freshen)
938 return check_and_freshen_local(oid, freshen) ||
939 check_and_freshen_nonlocal(oid, freshen);
942 int has_loose_object_nonlocal(const struct object_id *oid)
944 return check_and_freshen_nonlocal(oid, 0);
947 static int has_loose_object(const struct object_id *oid)
949 return check_and_freshen(oid, 0);
952 static void mmap_limit_check(size_t length)
954 static size_t limit = 0;
955 if (!limit) {
956 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
957 if (!limit)
958 limit = SIZE_MAX;
960 if (length > limit)
961 die(_("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX),
962 (uintmax_t)length, (uintmax_t)limit);
965 void *xmmap_gently(void *start, size_t length,
966 int prot, int flags, int fd, off_t offset)
968 void *ret;
970 mmap_limit_check(length);
971 ret = mmap(start, length, prot, flags, fd, offset);
972 if (ret == MAP_FAILED && !length)
973 ret = NULL;
974 return ret;
977 void *xmmap(void *start, size_t length,
978 int prot, int flags, int fd, off_t offset)
980 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
981 if (ret == MAP_FAILED)
982 die_errno(_("mmap failed"));
983 return ret;
987 * With an in-core object data in "map", rehash it to make sure the
988 * object name actually matches "oid" to detect object corruption.
989 * With "map" == NULL, try reading the object named with "oid" using
990 * the streaming interface and rehash it to do the same.
992 int check_object_signature(struct repository *r, const struct object_id *oid,
993 void *map, unsigned long size, const char *type)
995 struct object_id real_oid;
996 enum object_type obj_type;
997 struct git_istream *st;
998 git_hash_ctx c;
999 char hdr[MAX_HEADER_LEN];
1000 int hdrlen;
1002 if (map) {
1003 hash_object_file(r->hash_algo, map, size, type, &real_oid);
1004 return !oideq(oid, &real_oid) ? -1 : 0;
1007 st = open_istream(r, oid, &obj_type, &size, NULL);
1008 if (!st)
1009 return -1;
1011 /* Generate the header */
1012 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(obj_type), (uintmax_t)size) + 1;
1014 /* Sha1.. */
1015 r->hash_algo->init_fn(&c);
1016 r->hash_algo->update_fn(&c, hdr, hdrlen);
1017 for (;;) {
1018 char buf[1024 * 16];
1019 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1021 if (readlen < 0) {
1022 close_istream(st);
1023 return -1;
1025 if (!readlen)
1026 break;
1027 r->hash_algo->update_fn(&c, buf, readlen);
1029 r->hash_algo->final_fn(real_oid.hash, &c);
1030 close_istream(st);
1031 return !oideq(oid, &real_oid) ? -1 : 0;
1034 int git_open_cloexec(const char *name, int flags)
1036 int fd;
1037 static int o_cloexec = O_CLOEXEC;
1039 fd = open(name, flags | o_cloexec);
1040 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
1041 /* Try again w/o O_CLOEXEC: the kernel might not support it */
1042 o_cloexec &= ~O_CLOEXEC;
1043 fd = open(name, flags | o_cloexec);
1046 #if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
1048 static int fd_cloexec = FD_CLOEXEC;
1050 if (!o_cloexec && 0 <= fd && fd_cloexec) {
1051 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
1052 int flags = fcntl(fd, F_GETFD);
1053 if (fcntl(fd, F_SETFD, flags | fd_cloexec))
1054 fd_cloexec = 0;
1057 #endif
1058 return fd;
1062 * Find "oid" as a loose object in the local repository or in an alternate.
1063 * Returns 0 on success, negative on failure.
1065 * The "path" out-parameter will give the path of the object we found (if any).
1066 * Note that it may point to static storage and is only valid until another
1067 * call to stat_loose_object().
1069 static int stat_loose_object(struct repository *r, const struct object_id *oid,
1070 struct stat *st, const char **path)
1072 struct object_directory *odb;
1073 static struct strbuf buf = STRBUF_INIT;
1075 prepare_alt_odb(r);
1076 for (odb = r->objects->odb; odb; odb = odb->next) {
1077 *path = odb_loose_path(odb, &buf, oid);
1078 if (!lstat(*path, st))
1079 return 0;
1082 return -1;
1086 * Like stat_loose_object(), but actually open the object and return the
1087 * descriptor. See the caveats on the "path" parameter above.
1089 static int open_loose_object(struct repository *r,
1090 const struct object_id *oid, const char **path)
1092 int fd;
1093 struct object_directory *odb;
1094 int most_interesting_errno = ENOENT;
1095 static struct strbuf buf = STRBUF_INIT;
1097 prepare_alt_odb(r);
1098 for (odb = r->objects->odb; odb; odb = odb->next) {
1099 *path = odb_loose_path(odb, &buf, oid);
1100 fd = git_open(*path);
1101 if (fd >= 0)
1102 return fd;
1104 if (most_interesting_errno == ENOENT)
1105 most_interesting_errno = errno;
1107 errno = most_interesting_errno;
1108 return -1;
1111 static int quick_has_loose(struct repository *r,
1112 const struct object_id *oid)
1114 struct object_directory *odb;
1116 prepare_alt_odb(r);
1117 for (odb = r->objects->odb; odb; odb = odb->next) {
1118 if (oid_array_lookup(odb_loose_cache(odb, oid), oid) >= 0)
1119 return 1;
1121 return 0;
1125 * Map the loose object at "path" if it is not NULL, or the path found by
1126 * searching for a loose object named "oid".
1128 static void *map_loose_object_1(struct repository *r, const char *path,
1129 const struct object_id *oid, unsigned long *size)
1131 void *map;
1132 int fd;
1134 if (path)
1135 fd = git_open(path);
1136 else
1137 fd = open_loose_object(r, oid, &path);
1138 map = NULL;
1139 if (fd >= 0) {
1140 struct stat st;
1142 if (!fstat(fd, &st)) {
1143 *size = xsize_t(st.st_size);
1144 if (!*size) {
1145 /* mmap() is forbidden on empty files */
1146 error(_("object file %s is empty"), path);
1147 close(fd);
1148 return NULL;
1150 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1152 close(fd);
1154 return map;
1157 void *map_loose_object(struct repository *r,
1158 const struct object_id *oid,
1159 unsigned long *size)
1161 return map_loose_object_1(r, NULL, oid, size);
1164 static int unpack_loose_short_header(git_zstream *stream,
1165 unsigned char *map, unsigned long mapsize,
1166 void *buffer, unsigned long bufsiz)
1168 int ret;
1170 /* Get the data stream */
1171 memset(stream, 0, sizeof(*stream));
1172 stream->next_in = map;
1173 stream->avail_in = mapsize;
1174 stream->next_out = buffer;
1175 stream->avail_out = bufsiz;
1177 git_inflate_init(stream);
1178 obj_read_unlock();
1179 ret = git_inflate(stream, 0);
1180 obj_read_lock();
1182 return ret;
1185 int unpack_loose_header(git_zstream *stream,
1186 unsigned char *map, unsigned long mapsize,
1187 void *buffer, unsigned long bufsiz)
1189 int status = unpack_loose_short_header(stream, map, mapsize,
1190 buffer, bufsiz);
1192 if (status < Z_OK)
1193 return status;
1195 /* Make sure we have the terminating NUL */
1196 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1197 return -1;
1198 return 0;
1201 static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map,
1202 unsigned long mapsize, void *buffer,
1203 unsigned long bufsiz, struct strbuf *header)
1205 int status;
1207 status = unpack_loose_short_header(stream, map, mapsize, buffer, bufsiz);
1208 if (status < Z_OK)
1209 return -1;
1212 * Check if entire header is unpacked in the first iteration.
1214 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1215 return 0;
1218 * buffer[0..bufsiz] was not large enough. Copy the partial
1219 * result out to header, and then append the result of further
1220 * reading the stream.
1222 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1223 stream->next_out = buffer;
1224 stream->avail_out = bufsiz;
1226 do {
1227 obj_read_unlock();
1228 status = git_inflate(stream, 0);
1229 obj_read_lock();
1230 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1231 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1232 return 0;
1233 stream->next_out = buffer;
1234 stream->avail_out = bufsiz;
1235 } while (status != Z_STREAM_END);
1236 return -1;
1239 static void *unpack_loose_rest(git_zstream *stream,
1240 void *buffer, unsigned long size,
1241 const struct object_id *oid)
1243 int bytes = strlen(buffer) + 1;
1244 unsigned char *buf = xmallocz(size);
1245 unsigned long n;
1246 int status = Z_OK;
1248 n = stream->total_out - bytes;
1249 if (n > size)
1250 n = size;
1251 memcpy(buf, (char *) buffer + bytes, n);
1252 bytes = n;
1253 if (bytes <= size) {
1255 * The above condition must be (bytes <= size), not
1256 * (bytes < size). In other words, even though we
1257 * expect no more output and set avail_out to zero,
1258 * the input zlib stream may have bytes that express
1259 * "this concludes the stream", and we *do* want to
1260 * eat that input.
1262 * Otherwise we would not be able to test that we
1263 * consumed all the input to reach the expected size;
1264 * we also want to check that zlib tells us that all
1265 * went well with status == Z_STREAM_END at the end.
1267 stream->next_out = buf + bytes;
1268 stream->avail_out = size - bytes;
1269 while (status == Z_OK) {
1270 obj_read_unlock();
1271 status = git_inflate(stream, Z_FINISH);
1272 obj_read_lock();
1275 if (status == Z_STREAM_END && !stream->avail_in) {
1276 git_inflate_end(stream);
1277 return buf;
1280 if (status < 0)
1281 error(_("corrupt loose object '%s'"), oid_to_hex(oid));
1282 else if (stream->avail_in)
1283 error(_("garbage at end of loose object '%s'"),
1284 oid_to_hex(oid));
1285 free(buf);
1286 return NULL;
1290 * We used to just use "sscanf()", but that's actually way
1291 * too permissive for what we want to check. So do an anal
1292 * object header parse by hand.
1294 static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
1295 unsigned int flags)
1297 const char *type_buf = hdr;
1298 unsigned long size;
1299 int type, type_len = 0;
1302 * The type can be of any size but is followed by
1303 * a space.
1305 for (;;) {
1306 char c = *hdr++;
1307 if (!c)
1308 return -1;
1309 if (c == ' ')
1310 break;
1311 type_len++;
1314 type = type_from_string_gently(type_buf, type_len, 1);
1315 if (oi->type_name)
1316 strbuf_add(oi->type_name, type_buf, type_len);
1318 * Set type to 0 if its an unknown object and
1319 * we're obtaining the type using '--allow-unknown-type'
1320 * option.
1322 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
1323 type = 0;
1324 else if (type < 0)
1325 die(_("invalid object type"));
1326 if (oi->typep)
1327 *oi->typep = type;
1330 * The length must follow immediately, and be in canonical
1331 * decimal format (ie "010" is not valid).
1333 size = *hdr++ - '0';
1334 if (size > 9)
1335 return -1;
1336 if (size) {
1337 for (;;) {
1338 unsigned long c = *hdr - '0';
1339 if (c > 9)
1340 break;
1341 hdr++;
1342 size = size * 10 + c;
1346 if (oi->sizep)
1347 *oi->sizep = size;
1350 * The length must be followed by a zero byte
1352 return *hdr ? -1 : type;
1355 int parse_loose_header(const char *hdr, unsigned long *sizep)
1357 struct object_info oi = OBJECT_INFO_INIT;
1359 oi.sizep = sizep;
1360 return parse_loose_header_extended(hdr, &oi, 0);
1363 static int loose_object_info(struct repository *r,
1364 const struct object_id *oid,
1365 struct object_info *oi, int flags)
1367 int status = 0;
1368 unsigned long mapsize;
1369 void *map;
1370 git_zstream stream;
1371 char hdr[MAX_HEADER_LEN];
1372 struct strbuf hdrbuf = STRBUF_INIT;
1373 unsigned long size_scratch;
1375 if (oi->delta_base_sha1)
1376 hashclr(oi->delta_base_sha1);
1379 * If we don't care about type or size, then we don't
1380 * need to look inside the object at all. Note that we
1381 * do not optimize out the stat call, even if the
1382 * caller doesn't care about the disk-size, since our
1383 * return value implicitly indicates whether the
1384 * object even exists.
1386 if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
1387 const char *path;
1388 struct stat st;
1389 if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
1390 return quick_has_loose(r, oid) ? 0 : -1;
1391 if (stat_loose_object(r, oid, &st, &path) < 0)
1392 return -1;
1393 if (oi->disk_sizep)
1394 *oi->disk_sizep = st.st_size;
1395 return 0;
1398 map = map_loose_object(r, oid, &mapsize);
1399 if (!map)
1400 return -1;
1402 if (!oi->sizep)
1403 oi->sizep = &size_scratch;
1405 if (oi->disk_sizep)
1406 *oi->disk_sizep = mapsize;
1407 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
1408 if (unpack_loose_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
1409 status = error(_("unable to unpack %s header with --allow-unknown-type"),
1410 oid_to_hex(oid));
1411 } else if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1412 status = error(_("unable to unpack %s header"),
1413 oid_to_hex(oid));
1414 if (status < 0)
1415 ; /* Do nothing */
1416 else if (hdrbuf.len) {
1417 if ((status = parse_loose_header_extended(hdrbuf.buf, oi, flags)) < 0)
1418 status = error(_("unable to parse %s header with --allow-unknown-type"),
1419 oid_to_hex(oid));
1420 } else if ((status = parse_loose_header_extended(hdr, oi, flags)) < 0)
1421 status = error(_("unable to parse %s header"), oid_to_hex(oid));
1423 if (status >= 0 && oi->contentp) {
1424 *oi->contentp = unpack_loose_rest(&stream, hdr,
1425 *oi->sizep, oid);
1426 if (!*oi->contentp) {
1427 git_inflate_end(&stream);
1428 status = -1;
1430 } else
1431 git_inflate_end(&stream);
1433 munmap(map, mapsize);
1434 if (status && oi->typep)
1435 *oi->typep = status;
1436 if (oi->sizep == &size_scratch)
1437 oi->sizep = NULL;
1438 strbuf_release(&hdrbuf);
1439 oi->whence = OI_LOOSE;
1440 return (status < 0) ? status : 0;
1443 int obj_read_use_lock = 0;
1444 pthread_mutex_t obj_read_mutex;
1446 void enable_obj_read_lock(void)
1448 if (obj_read_use_lock)
1449 return;
1451 obj_read_use_lock = 1;
1452 init_recursive_mutex(&obj_read_mutex);
1455 void disable_obj_read_lock(void)
1457 if (!obj_read_use_lock)
1458 return;
1460 obj_read_use_lock = 0;
1461 pthread_mutex_destroy(&obj_read_mutex);
1464 int fetch_if_missing = 1;
1466 static int do_oid_object_info_extended(struct repository *r,
1467 const struct object_id *oid,
1468 struct object_info *oi, unsigned flags)
1470 static struct object_info blank_oi = OBJECT_INFO_INIT;
1471 struct cached_object *co;
1472 struct pack_entry e;
1473 int rtype;
1474 const struct object_id *real = oid;
1475 int already_retried = 0;
1478 if (flags & OBJECT_INFO_LOOKUP_REPLACE)
1479 real = lookup_replace_object(r, oid);
1481 if (is_null_oid(real))
1482 return -1;
1484 if (!oi)
1485 oi = &blank_oi;
1487 co = find_cached_object(real);
1488 if (co) {
1489 if (oi->typep)
1490 *(oi->typep) = co->type;
1491 if (oi->sizep)
1492 *(oi->sizep) = co->size;
1493 if (oi->disk_sizep)
1494 *(oi->disk_sizep) = 0;
1495 if (oi->delta_base_sha1)
1496 hashclr(oi->delta_base_sha1);
1497 if (oi->type_name)
1498 strbuf_addstr(oi->type_name, type_name(co->type));
1499 if (oi->contentp)
1500 *oi->contentp = xmemdupz(co->buf, co->size);
1501 oi->whence = OI_CACHED;
1502 return 0;
1505 while (1) {
1506 if (find_pack_entry(r, real, &e))
1507 break;
1509 if (flags & OBJECT_INFO_IGNORE_LOOSE)
1510 return -1;
1512 /* Most likely it's a loose object. */
1513 if (!loose_object_info(r, real, oi, flags))
1514 return 0;
1516 /* Not a loose object; someone else may have just packed it. */
1517 if (!(flags & OBJECT_INFO_QUICK)) {
1518 reprepare_packed_git(r);
1519 if (find_pack_entry(r, real, &e))
1520 break;
1523 /* Check if it is a missing object */
1524 if (fetch_if_missing && has_promisor_remote() &&
1525 !already_retried && r == the_repository &&
1526 !(flags & OBJECT_INFO_SKIP_FETCH_OBJECT)) {
1528 * TODO Investigate checking promisor_remote_get_direct()
1529 * TODO return value and stopping on error here.
1530 * TODO Pass a repository struct through
1531 * promisor_remote_get_direct(), such that arbitrary
1532 * repositories work.
1534 promisor_remote_get_direct(r, real, 1);
1535 already_retried = 1;
1536 continue;
1539 return -1;
1542 if (oi == &blank_oi)
1544 * We know that the caller doesn't actually need the
1545 * information below, so return early.
1547 return 0;
1548 rtype = packed_object_info(r, e.p, e.offset, oi);
1549 if (rtype < 0) {
1550 mark_bad_packed_object(e.p, real->hash);
1551 return do_oid_object_info_extended(r, real, oi, 0);
1552 } else if (oi->whence == OI_PACKED) {
1553 oi->u.packed.offset = e.offset;
1554 oi->u.packed.pack = e.p;
1555 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
1556 rtype == OBJ_OFS_DELTA);
1559 return 0;
1562 int oid_object_info_extended(struct repository *r, const struct object_id *oid,
1563 struct object_info *oi, unsigned flags)
1565 int ret;
1566 obj_read_lock();
1567 ret = do_oid_object_info_extended(r, oid, oi, flags);
1568 obj_read_unlock();
1569 return ret;
1573 /* returns enum object_type or negative */
1574 int oid_object_info(struct repository *r,
1575 const struct object_id *oid,
1576 unsigned long *sizep)
1578 enum object_type type;
1579 struct object_info oi = OBJECT_INFO_INIT;
1581 oi.typep = &type;
1582 oi.sizep = sizep;
1583 if (oid_object_info_extended(r, oid, &oi,
1584 OBJECT_INFO_LOOKUP_REPLACE) < 0)
1585 return -1;
1586 return type;
1589 static void *read_object(struct repository *r,
1590 const struct object_id *oid, enum object_type *type,
1591 unsigned long *size)
1593 struct object_info oi = OBJECT_INFO_INIT;
1594 void *content;
1595 oi.typep = type;
1596 oi.sizep = size;
1597 oi.contentp = &content;
1599 if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1600 return NULL;
1601 return content;
1604 int pretend_object_file(void *buf, unsigned long len, enum object_type type,
1605 struct object_id *oid)
1607 struct cached_object *co;
1609 hash_object_file(the_hash_algo, buf, len, type_name(type), oid);
1610 if (has_object_file(oid) || find_cached_object(oid))
1611 return 0;
1612 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
1613 co = &cached_objects[cached_object_nr++];
1614 co->size = len;
1615 co->type = type;
1616 co->buf = xmalloc(len);
1617 memcpy(co->buf, buf, len);
1618 oidcpy(&co->oid, oid);
1619 return 0;
1623 * This function dies on corrupt objects; the callers who want to
1624 * deal with them should arrange to call read_object() and give error
1625 * messages themselves.
1627 void *read_object_file_extended(struct repository *r,
1628 const struct object_id *oid,
1629 enum object_type *type,
1630 unsigned long *size,
1631 int lookup_replace)
1633 void *data;
1634 const struct packed_git *p;
1635 const char *path;
1636 struct stat st;
1637 const struct object_id *repl = lookup_replace ?
1638 lookup_replace_object(r, oid) : oid;
1640 errno = 0;
1641 data = read_object(r, repl, type, size);
1642 if (data)
1643 return data;
1645 obj_read_lock();
1646 if (errno && errno != ENOENT)
1647 die_errno(_("failed to read object %s"), oid_to_hex(oid));
1649 /* die if we replaced an object with one that does not exist */
1650 if (repl != oid)
1651 die(_("replacement %s not found for %s"),
1652 oid_to_hex(repl), oid_to_hex(oid));
1654 if (!stat_loose_object(r, repl, &st, &path))
1655 die(_("loose object %s (stored in %s) is corrupt"),
1656 oid_to_hex(repl), path);
1658 if ((p = has_packed_and_bad(r, repl->hash)) != NULL)
1659 die(_("packed object %s (stored in %s) is corrupt"),
1660 oid_to_hex(repl), p->pack_name);
1661 obj_read_unlock();
1663 return NULL;
1666 void *read_object_with_reference(struct repository *r,
1667 const struct object_id *oid,
1668 const char *required_type_name,
1669 unsigned long *size,
1670 struct object_id *actual_oid_return)
1672 enum object_type type, required_type;
1673 void *buffer;
1674 unsigned long isize;
1675 struct object_id actual_oid;
1677 required_type = type_from_string(required_type_name);
1678 oidcpy(&actual_oid, oid);
1679 while (1) {
1680 int ref_length = -1;
1681 const char *ref_type = NULL;
1683 buffer = repo_read_object_file(r, &actual_oid, &type, &isize);
1684 if (!buffer)
1685 return NULL;
1686 if (type == required_type) {
1687 *size = isize;
1688 if (actual_oid_return)
1689 oidcpy(actual_oid_return, &actual_oid);
1690 return buffer;
1692 /* Handle references */
1693 else if (type == OBJ_COMMIT)
1694 ref_type = "tree ";
1695 else if (type == OBJ_TAG)
1696 ref_type = "object ";
1697 else {
1698 free(buffer);
1699 return NULL;
1701 ref_length = strlen(ref_type);
1703 if (ref_length + the_hash_algo->hexsz > isize ||
1704 memcmp(buffer, ref_type, ref_length) ||
1705 get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
1706 free(buffer);
1707 return NULL;
1709 free(buffer);
1710 /* Now we have the ID of the referred-to object in
1711 * actual_oid. Check again. */
1715 static void write_object_file_prepare(const struct git_hash_algo *algo,
1716 const void *buf, unsigned long len,
1717 const char *type, struct object_id *oid,
1718 char *hdr, int *hdrlen)
1720 git_hash_ctx c;
1722 /* Generate the header */
1723 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %"PRIuMAX , type, (uintmax_t)len)+1;
1725 /* Sha1.. */
1726 algo->init_fn(&c);
1727 algo->update_fn(&c, hdr, *hdrlen);
1728 algo->update_fn(&c, buf, len);
1729 algo->final_fn(oid->hash, &c);
1733 * Move the just written object into its final resting place.
1735 int finalize_object_file(const char *tmpfile, const char *filename)
1737 int ret = 0;
1739 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
1740 goto try_rename;
1741 else if (link(tmpfile, filename))
1742 ret = errno;
1745 * Coda hack - coda doesn't like cross-directory links,
1746 * so we fall back to a rename, which will mean that it
1747 * won't be able to check collisions, but that's not a
1748 * big deal.
1750 * The same holds for FAT formatted media.
1752 * When this succeeds, we just return. We have nothing
1753 * left to unlink.
1755 if (ret && ret != EEXIST) {
1756 try_rename:
1757 if (!rename(tmpfile, filename))
1758 goto out;
1759 ret = errno;
1761 unlink_or_warn(tmpfile);
1762 if (ret) {
1763 if (ret != EEXIST) {
1764 return error_errno(_("unable to write file %s"), filename);
1766 /* FIXME!!! Collision check here ? */
1769 out:
1770 if (adjust_shared_perm(filename))
1771 return error(_("unable to set permission to '%s'"), filename);
1772 return 0;
1775 static int write_buffer(int fd, const void *buf, size_t len)
1777 if (write_in_full(fd, buf, len) < 0)
1778 return error_errno(_("file write error"));
1779 return 0;
1782 int hash_object_file(const struct git_hash_algo *algo, const void *buf,
1783 unsigned long len, const char *type,
1784 struct object_id *oid)
1786 char hdr[MAX_HEADER_LEN];
1787 int hdrlen = sizeof(hdr);
1788 write_object_file_prepare(algo, buf, len, type, oid, hdr, &hdrlen);
1789 return 0;
1792 /* Finalize a file on disk, and close it. */
1793 static void close_loose_object(int fd)
1795 if (fsync_object_files)
1796 fsync_or_die(fd, "loose object file");
1797 if (close(fd) != 0)
1798 die_errno(_("error when closing loose object file"));
1801 /* Size of directory component, including the ending '/' */
1802 static inline int directory_size(const char *filename)
1804 const char *s = strrchr(filename, '/');
1805 if (!s)
1806 return 0;
1807 return s - filename + 1;
1811 * This creates a temporary file in the same directory as the final
1812 * 'filename'
1814 * We want to avoid cross-directory filename renames, because those
1815 * can have problems on various filesystems (FAT, NFS, Coda).
1817 static int create_tmpfile(struct strbuf *tmp, const char *filename)
1819 int fd, dirlen = directory_size(filename);
1821 strbuf_reset(tmp);
1822 strbuf_add(tmp, filename, dirlen);
1823 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
1824 fd = git_mkstemp_mode(tmp->buf, 0444);
1825 if (fd < 0 && dirlen && errno == ENOENT) {
1827 * Make sure the directory exists; note that the contents
1828 * of the buffer are undefined after mkstemp returns an
1829 * error, so we have to rewrite the whole buffer from
1830 * scratch.
1832 strbuf_reset(tmp);
1833 strbuf_add(tmp, filename, dirlen - 1);
1834 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
1835 return -1;
1836 if (adjust_shared_perm(tmp->buf))
1837 return -1;
1839 /* Try again */
1840 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
1841 fd = git_mkstemp_mode(tmp->buf, 0444);
1843 return fd;
1846 static int write_loose_object(const struct object_id *oid, char *hdr,
1847 int hdrlen, const void *buf, unsigned long len,
1848 time_t mtime)
1850 int fd, ret;
1851 unsigned char compressed[4096];
1852 git_zstream stream;
1853 git_hash_ctx c;
1854 struct object_id parano_oid;
1855 static struct strbuf tmp_file = STRBUF_INIT;
1856 static struct strbuf filename = STRBUF_INIT;
1858 loose_object_path(the_repository, &filename, oid);
1860 fd = create_tmpfile(&tmp_file, filename.buf);
1861 if (fd < 0) {
1862 if (errno == EACCES)
1863 return error(_("insufficient permission for adding an object to repository database %s"), get_object_directory());
1864 else
1865 return error_errno(_("unable to create temporary file"));
1868 /* Set it up */
1869 git_deflate_init(&stream, zlib_compression_level);
1870 stream.next_out = compressed;
1871 stream.avail_out = sizeof(compressed);
1872 the_hash_algo->init_fn(&c);
1874 /* First header.. */
1875 stream.next_in = (unsigned char *)hdr;
1876 stream.avail_in = hdrlen;
1877 while (git_deflate(&stream, 0) == Z_OK)
1878 ; /* nothing */
1879 the_hash_algo->update_fn(&c, hdr, hdrlen);
1881 /* Then the data itself.. */
1882 stream.next_in = (void *)buf;
1883 stream.avail_in = len;
1884 do {
1885 unsigned char *in0 = stream.next_in;
1886 ret = git_deflate(&stream, Z_FINISH);
1887 the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
1888 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
1889 die(_("unable to write loose object file"));
1890 stream.next_out = compressed;
1891 stream.avail_out = sizeof(compressed);
1892 } while (ret == Z_OK);
1894 if (ret != Z_STREAM_END)
1895 die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
1896 ret);
1897 ret = git_deflate_end_gently(&stream);
1898 if (ret != Z_OK)
1899 die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
1900 ret);
1901 the_hash_algo->final_fn(parano_oid.hash, &c);
1902 if (!oideq(oid, &parano_oid))
1903 die(_("confused by unstable object source data for %s"),
1904 oid_to_hex(oid));
1906 close_loose_object(fd);
1908 if (mtime) {
1909 struct utimbuf utb;
1910 utb.actime = mtime;
1911 utb.modtime = mtime;
1912 if (utime(tmp_file.buf, &utb) < 0)
1913 warning_errno(_("failed utime() on %s"), tmp_file.buf);
1916 return finalize_object_file(tmp_file.buf, filename.buf);
1919 static int freshen_loose_object(const struct object_id *oid)
1921 return check_and_freshen(oid, 1);
1924 static int freshen_packed_object(const struct object_id *oid)
1926 struct pack_entry e;
1927 if (!find_pack_entry(the_repository, oid, &e))
1928 return 0;
1929 if (e.p->freshened)
1930 return 1;
1931 if (!freshen_file(e.p->pack_name))
1932 return 0;
1933 e.p->freshened = 1;
1934 return 1;
1937 int write_object_file(const void *buf, unsigned long len, const char *type,
1938 struct object_id *oid)
1940 char hdr[MAX_HEADER_LEN];
1941 int hdrlen = sizeof(hdr);
1943 /* Normally if we have it in the pack then we do not bother writing
1944 * it out into .git/objects/??/?{38} file.
1946 write_object_file_prepare(the_hash_algo, buf, len, type, oid, hdr,
1947 &hdrlen);
1948 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1949 return 0;
1950 return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
1953 int hash_object_file_literally(const void *buf, unsigned long len,
1954 const char *type, struct object_id *oid,
1955 unsigned flags)
1957 char *header;
1958 int hdrlen, status = 0;
1960 /* type string, SP, %lu of the length plus NUL must fit this */
1961 hdrlen = strlen(type) + MAX_HEADER_LEN;
1962 header = xmalloc(hdrlen);
1963 write_object_file_prepare(the_hash_algo, buf, len, type, oid, header,
1964 &hdrlen);
1966 if (!(flags & HASH_WRITE_OBJECT))
1967 goto cleanup;
1968 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1969 goto cleanup;
1970 status = write_loose_object(oid, header, hdrlen, buf, len, 0);
1972 cleanup:
1973 free(header);
1974 return status;
1977 int force_object_loose(const struct object_id *oid, time_t mtime)
1979 void *buf;
1980 unsigned long len;
1981 enum object_type type;
1982 char hdr[MAX_HEADER_LEN];
1983 int hdrlen;
1984 int ret;
1986 if (has_loose_object(oid))
1987 return 0;
1988 buf = read_object(the_repository, oid, &type, &len);
1989 if (!buf)
1990 return error(_("cannot read object for %s"), oid_to_hex(oid));
1991 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(type), (uintmax_t)len) + 1;
1992 ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
1993 free(buf);
1995 return ret;
1998 int repo_has_object_file_with_flags(struct repository *r,
1999 const struct object_id *oid, int flags)
2001 if (!startup_info->have_repository)
2002 return 0;
2003 return oid_object_info_extended(r, oid, NULL, flags) >= 0;
2006 int repo_has_object_file(struct repository *r,
2007 const struct object_id *oid)
2009 return repo_has_object_file_with_flags(r, oid, 0);
2012 static void check_tree(const void *buf, size_t size)
2014 struct tree_desc desc;
2015 struct name_entry entry;
2017 init_tree_desc(&desc, buf, size);
2018 while (tree_entry(&desc, &entry))
2019 /* do nothing
2020 * tree_entry() will die() on malformed entries */
2024 static void check_commit(const void *buf, size_t size)
2026 struct commit c;
2027 memset(&c, 0, sizeof(c));
2028 if (parse_commit_buffer(the_repository, &c, buf, size, 0))
2029 die(_("corrupt commit"));
2032 static void check_tag(const void *buf, size_t size)
2034 struct tag t;
2035 memset(&t, 0, sizeof(t));
2036 if (parse_tag_buffer(the_repository, &t, buf, size))
2037 die(_("corrupt tag"));
2040 static int index_mem(struct index_state *istate,
2041 struct object_id *oid, void *buf, size_t size,
2042 enum object_type type,
2043 const char *path, unsigned flags)
2045 int ret, re_allocated = 0;
2046 int write_object = flags & HASH_WRITE_OBJECT;
2048 if (!type)
2049 type = OBJ_BLOB;
2052 * Convert blobs to git internal format
2054 if ((type == OBJ_BLOB) && path) {
2055 struct strbuf nbuf = STRBUF_INIT;
2056 if (convert_to_git(istate, path, buf, size, &nbuf,
2057 get_conv_flags(flags))) {
2058 buf = strbuf_detach(&nbuf, &size);
2059 re_allocated = 1;
2062 if (flags & HASH_FORMAT_CHECK) {
2063 if (type == OBJ_TREE)
2064 check_tree(buf, size);
2065 if (type == OBJ_COMMIT)
2066 check_commit(buf, size);
2067 if (type == OBJ_TAG)
2068 check_tag(buf, size);
2071 if (write_object)
2072 ret = write_object_file(buf, size, type_name(type), oid);
2073 else
2074 ret = hash_object_file(the_hash_algo, buf, size,
2075 type_name(type), oid);
2076 if (re_allocated)
2077 free(buf);
2078 return ret;
2081 static int index_stream_convert_blob(struct index_state *istate,
2082 struct object_id *oid,
2083 int fd,
2084 const char *path,
2085 unsigned flags)
2087 int ret;
2088 const int write_object = flags & HASH_WRITE_OBJECT;
2089 struct strbuf sbuf = STRBUF_INIT;
2091 assert(path);
2092 assert(would_convert_to_git_filter_fd(istate, path));
2094 convert_to_git_filter_fd(istate, path, fd, &sbuf,
2095 get_conv_flags(flags));
2097 if (write_object)
2098 ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
2099 oid);
2100 else
2101 ret = hash_object_file(the_hash_algo, sbuf.buf, sbuf.len,
2102 type_name(OBJ_BLOB), oid);
2103 strbuf_release(&sbuf);
2104 return ret;
2107 static int index_pipe(struct index_state *istate, struct object_id *oid,
2108 int fd, enum object_type type,
2109 const char *path, unsigned flags)
2111 struct strbuf sbuf = STRBUF_INIT;
2112 int ret;
2114 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2115 ret = index_mem(istate, oid, sbuf.buf, sbuf.len, type, path, flags);
2116 else
2117 ret = -1;
2118 strbuf_release(&sbuf);
2119 return ret;
2122 #define SMALL_FILE_SIZE (32*1024)
2124 static int index_core(struct index_state *istate,
2125 struct object_id *oid, int fd, size_t size,
2126 enum object_type type, const char *path,
2127 unsigned flags)
2129 int ret;
2131 if (!size) {
2132 ret = index_mem(istate, oid, "", size, type, path, flags);
2133 } else if (size <= SMALL_FILE_SIZE) {
2134 char *buf = xmalloc(size);
2135 ssize_t read_result = read_in_full(fd, buf, size);
2136 if (read_result < 0)
2137 ret = error_errno(_("read error while indexing %s"),
2138 path ? path : "<unknown>");
2139 else if (read_result != size)
2140 ret = error(_("short read while indexing %s"),
2141 path ? path : "<unknown>");
2142 else
2143 ret = index_mem(istate, oid, buf, size, type, path, flags);
2144 free(buf);
2145 } else {
2146 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2147 ret = index_mem(istate, oid, buf, size, type, path, flags);
2148 munmap(buf, size);
2150 return ret;
2154 * This creates one packfile per large blob unless bulk-checkin
2155 * machinery is "plugged".
2157 * This also bypasses the usual "convert-to-git" dance, and that is on
2158 * purpose. We could write a streaming version of the converting
2159 * functions and insert that before feeding the data to fast-import
2160 * (or equivalent in-core API described above). However, that is
2161 * somewhat complicated, as we do not know the size of the filter
2162 * result, which we need to know beforehand when writing a git object.
2163 * Since the primary motivation for trying to stream from the working
2164 * tree file and to avoid mmaping it in core is to deal with large
2165 * binary blobs, they generally do not want to get any conversion, and
2166 * callers should avoid this code path when filters are requested.
2168 static int index_stream(struct object_id *oid, int fd, size_t size,
2169 enum object_type type, const char *path,
2170 unsigned flags)
2172 return index_bulk_checkin(oid, fd, size, type, path, flags);
2175 int index_fd(struct index_state *istate, struct object_id *oid,
2176 int fd, struct stat *st,
2177 enum object_type type, const char *path, unsigned flags)
2179 int ret;
2182 * Call xsize_t() only when needed to avoid potentially unnecessary
2183 * die() for large files.
2185 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
2186 ret = index_stream_convert_blob(istate, oid, fd, path, flags);
2187 else if (!S_ISREG(st->st_mode))
2188 ret = index_pipe(istate, oid, fd, type, path, flags);
2189 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
2190 (path && would_convert_to_git(istate, path)))
2191 ret = index_core(istate, oid, fd, xsize_t(st->st_size),
2192 type, path, flags);
2193 else
2194 ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
2195 flags);
2196 close(fd);
2197 return ret;
2200 int index_path(struct index_state *istate, struct object_id *oid,
2201 const char *path, struct stat *st, unsigned flags)
2203 int fd;
2204 struct strbuf sb = STRBUF_INIT;
2205 int rc = 0;
2207 switch (st->st_mode & S_IFMT) {
2208 case S_IFREG:
2209 fd = open(path, O_RDONLY);
2210 if (fd < 0)
2211 return error_errno("open(\"%s\")", path);
2212 if (index_fd(istate, oid, fd, st, OBJ_BLOB, path, flags) < 0)
2213 return error(_("%s: failed to insert into database"),
2214 path);
2215 break;
2216 case S_IFLNK:
2217 if (strbuf_readlink(&sb, path, st->st_size))
2218 return error_errno("readlink(\"%s\")", path);
2219 if (!(flags & HASH_WRITE_OBJECT))
2220 hash_object_file(the_hash_algo, sb.buf, sb.len,
2221 blob_type, oid);
2222 else if (write_object_file(sb.buf, sb.len, blob_type, oid))
2223 rc = error(_("%s: failed to insert into database"), path);
2224 strbuf_release(&sb);
2225 break;
2226 case S_IFDIR:
2227 return resolve_gitlink_ref(path, "HEAD", oid);
2228 default:
2229 return error(_("%s: unsupported file type"), path);
2231 return rc;
2234 int read_pack_header(int fd, struct pack_header *header)
2236 if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
2237 /* "eof before pack header was fully read" */
2238 return PH_ERROR_EOF;
2240 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2241 /* "protocol error (pack signature mismatch detected)" */
2242 return PH_ERROR_PACK_SIGNATURE;
2243 if (!pack_version_ok(header->hdr_version))
2244 /* "protocol error (pack version unsupported)" */
2245 return PH_ERROR_PROTOCOL;
2246 return 0;
2249 void assert_oid_type(const struct object_id *oid, enum object_type expect)
2251 enum object_type type = oid_object_info(the_repository, oid, NULL);
2252 if (type < 0)
2253 die(_("%s is not a valid object"), oid_to_hex(oid));
2254 if (type != expect)
2255 die(_("%s is not a valid '%s' object"), oid_to_hex(oid),
2256 type_name(expect));
2259 int for_each_file_in_obj_subdir(unsigned int subdir_nr,
2260 struct strbuf *path,
2261 each_loose_object_fn obj_cb,
2262 each_loose_cruft_fn cruft_cb,
2263 each_loose_subdir_fn subdir_cb,
2264 void *data)
2266 size_t origlen, baselen;
2267 DIR *dir;
2268 struct dirent *de;
2269 int r = 0;
2270 struct object_id oid;
2272 if (subdir_nr > 0xff)
2273 BUG("invalid loose object subdirectory: %x", subdir_nr);
2275 origlen = path->len;
2276 strbuf_complete(path, '/');
2277 strbuf_addf(path, "%02x", subdir_nr);
2279 dir = opendir(path->buf);
2280 if (!dir) {
2281 if (errno != ENOENT)
2282 r = error_errno(_("unable to open %s"), path->buf);
2283 strbuf_setlen(path, origlen);
2284 return r;
2287 oid.hash[0] = subdir_nr;
2288 strbuf_addch(path, '/');
2289 baselen = path->len;
2291 while ((de = readdir(dir))) {
2292 size_t namelen;
2293 if (is_dot_or_dotdot(de->d_name))
2294 continue;
2296 namelen = strlen(de->d_name);
2297 strbuf_setlen(path, baselen);
2298 strbuf_add(path, de->d_name, namelen);
2299 if (namelen == the_hash_algo->hexsz - 2 &&
2300 !hex_to_bytes(oid.hash + 1, de->d_name,
2301 the_hash_algo->rawsz - 1)) {
2302 if (obj_cb) {
2303 r = obj_cb(&oid, path->buf, data);
2304 if (r)
2305 break;
2307 continue;
2310 if (cruft_cb) {
2311 r = cruft_cb(de->d_name, path->buf, data);
2312 if (r)
2313 break;
2316 closedir(dir);
2318 strbuf_setlen(path, baselen - 1);
2319 if (!r && subdir_cb)
2320 r = subdir_cb(subdir_nr, path->buf, data);
2322 strbuf_setlen(path, origlen);
2324 return r;
2327 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
2328 each_loose_object_fn obj_cb,
2329 each_loose_cruft_fn cruft_cb,
2330 each_loose_subdir_fn subdir_cb,
2331 void *data)
2333 int r = 0;
2334 int i;
2336 for (i = 0; i < 256; i++) {
2337 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
2338 subdir_cb, data);
2339 if (r)
2340 break;
2343 return r;
2346 int for_each_loose_file_in_objdir(const char *path,
2347 each_loose_object_fn obj_cb,
2348 each_loose_cruft_fn cruft_cb,
2349 each_loose_subdir_fn subdir_cb,
2350 void *data)
2352 struct strbuf buf = STRBUF_INIT;
2353 int r;
2355 strbuf_addstr(&buf, path);
2356 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
2357 subdir_cb, data);
2358 strbuf_release(&buf);
2360 return r;
2363 int for_each_loose_object(each_loose_object_fn cb, void *data,
2364 enum for_each_object_flags flags)
2366 struct object_directory *odb;
2368 prepare_alt_odb(the_repository);
2369 for (odb = the_repository->objects->odb; odb; odb = odb->next) {
2370 int r = for_each_loose_file_in_objdir(odb->path, cb, NULL,
2371 NULL, data);
2372 if (r)
2373 return r;
2375 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
2376 break;
2379 return 0;
2382 static int append_loose_object(const struct object_id *oid, const char *path,
2383 void *data)
2385 oid_array_append(data, oid);
2386 return 0;
2389 struct oid_array *odb_loose_cache(struct object_directory *odb,
2390 const struct object_id *oid)
2392 int subdir_nr = oid->hash[0];
2393 struct strbuf buf = STRBUF_INIT;
2395 if (subdir_nr < 0 ||
2396 subdir_nr >= ARRAY_SIZE(odb->loose_objects_subdir_seen))
2397 BUG("subdir_nr out of range");
2399 if (odb->loose_objects_subdir_seen[subdir_nr])
2400 return &odb->loose_objects_cache[subdir_nr];
2402 strbuf_addstr(&buf, odb->path);
2403 for_each_file_in_obj_subdir(subdir_nr, &buf,
2404 append_loose_object,
2405 NULL, NULL,
2406 &odb->loose_objects_cache[subdir_nr]);
2407 odb->loose_objects_subdir_seen[subdir_nr] = 1;
2408 strbuf_release(&buf);
2409 return &odb->loose_objects_cache[subdir_nr];
2412 void odb_clear_loose_cache(struct object_directory *odb)
2414 int i;
2416 for (i = 0; i < ARRAY_SIZE(odb->loose_objects_cache); i++)
2417 oid_array_clear(&odb->loose_objects_cache[i]);
2418 memset(&odb->loose_objects_subdir_seen, 0,
2419 sizeof(odb->loose_objects_subdir_seen));
2422 static int check_stream_oid(git_zstream *stream,
2423 const char *hdr,
2424 unsigned long size,
2425 const char *path,
2426 const struct object_id *expected_oid)
2428 git_hash_ctx c;
2429 struct object_id real_oid;
2430 unsigned char buf[4096];
2431 unsigned long total_read;
2432 int status = Z_OK;
2434 the_hash_algo->init_fn(&c);
2435 the_hash_algo->update_fn(&c, hdr, stream->total_out);
2438 * We already read some bytes into hdr, but the ones up to the NUL
2439 * do not count against the object's content size.
2441 total_read = stream->total_out - strlen(hdr) - 1;
2444 * This size comparison must be "<=" to read the final zlib packets;
2445 * see the comment in unpack_loose_rest for details.
2447 while (total_read <= size &&
2448 (status == Z_OK ||
2449 (status == Z_BUF_ERROR && !stream->avail_out))) {
2450 stream->next_out = buf;
2451 stream->avail_out = sizeof(buf);
2452 if (size - total_read < stream->avail_out)
2453 stream->avail_out = size - total_read;
2454 status = git_inflate(stream, Z_FINISH);
2455 the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
2456 total_read += stream->next_out - buf;
2458 git_inflate_end(stream);
2460 if (status != Z_STREAM_END) {
2461 error(_("corrupt loose object '%s'"), oid_to_hex(expected_oid));
2462 return -1;
2464 if (stream->avail_in) {
2465 error(_("garbage at end of loose object '%s'"),
2466 oid_to_hex(expected_oid));
2467 return -1;
2470 the_hash_algo->final_fn(real_oid.hash, &c);
2471 if (!oideq(expected_oid, &real_oid)) {
2472 error(_("hash mismatch for %s (expected %s)"), path,
2473 oid_to_hex(expected_oid));
2474 return -1;
2477 return 0;
2480 int read_loose_object(const char *path,
2481 const struct object_id *expected_oid,
2482 enum object_type *type,
2483 unsigned long *size,
2484 void **contents)
2486 int ret = -1;
2487 void *map = NULL;
2488 unsigned long mapsize;
2489 git_zstream stream;
2490 char hdr[MAX_HEADER_LEN];
2492 *contents = NULL;
2494 map = map_loose_object_1(the_repository, path, NULL, &mapsize);
2495 if (!map) {
2496 error_errno(_("unable to mmap %s"), path);
2497 goto out;
2500 if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
2501 error(_("unable to unpack header of %s"), path);
2502 goto out;
2505 *type = parse_loose_header(hdr, size);
2506 if (*type < 0) {
2507 error(_("unable to parse header of %s"), path);
2508 git_inflate_end(&stream);
2509 goto out;
2512 if (*type == OBJ_BLOB && *size > big_file_threshold) {
2513 if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
2514 goto out;
2515 } else {
2516 *contents = unpack_loose_rest(&stream, hdr, *size, expected_oid);
2517 if (!*contents) {
2518 error(_("unable to unpack contents of %s"), path);
2519 git_inflate_end(&stream);
2520 goto out;
2522 if (check_object_signature(the_repository, expected_oid,
2523 *contents, *size,
2524 type_name(*type))) {
2525 error(_("hash mismatch for %s (expected %s)"), path,
2526 oid_to_hex(expected_oid));
2527 free(*contents);
2528 goto out;
2532 ret = 0; /* everything checks out */
2534 out:
2535 if (map)
2536 munmap(map, mapsize);
2537 return ret;