5081d585a2ee17f6f456867c6b321a2e5e9c1e0a
[git/git.git] / sha1_file.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "config.h"
11 #include "string-list.h"
12 #include "lockfile.h"
13 #include "delta.h"
14 #include "pack.h"
15 #include "blob.h"
16 #include "commit.h"
17 #include "run-command.h"
18 #include "tag.h"
19 #include "tree.h"
20 #include "tree-walk.h"
21 #include "refs.h"
22 #include "pack-revindex.h"
23 #include "sha1-lookup.h"
24 #include "bulk-checkin.h"
25 #include "streaming.h"
26 #include "dir.h"
27 #include "list.h"
28 #include "mergesort.h"
29 #include "quote.h"
30 #include "packfile.h"
31 #include "fetch-object.h"
32
33 const unsigned char null_sha1[GIT_MAX_RAWSZ];
34 const struct object_id null_oid;
35 const struct object_id empty_tree_oid = {
36 EMPTY_TREE_SHA1_BIN_LITERAL
37 };
38 const struct object_id empty_blob_oid = {
39 EMPTY_BLOB_SHA1_BIN_LITERAL
40 };
41
42 static void git_hash_sha1_init(git_hash_ctx *ctx)
43 {
44 git_SHA1_Init(&ctx->sha1);
45 }
46
47 static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
48 {
49 git_SHA1_Update(&ctx->sha1, data, len);
50 }
51
52 static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
53 {
54 git_SHA1_Final(hash, &ctx->sha1);
55 }
56
57 static void git_hash_unknown_init(git_hash_ctx *ctx)
58 {
59 die("trying to init unknown hash");
60 }
61
62 static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
63 {
64 die("trying to update unknown hash");
65 }
66
67 static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
68 {
69 die("trying to finalize unknown hash");
70 }
71
72 const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
73 {
74 NULL,
75 0x00000000,
76 0,
77 0,
78 git_hash_unknown_init,
79 git_hash_unknown_update,
80 git_hash_unknown_final,
81 NULL,
82 NULL,
83 },
84 {
85 "sha-1",
86 /* "sha1", big-endian */
87 0x73686131,
88 GIT_SHA1_RAWSZ,
89 GIT_SHA1_HEXSZ,
90 git_hash_sha1_init,
91 git_hash_sha1_update,
92 git_hash_sha1_final,
93 &empty_tree_oid,
94 &empty_blob_oid,
95 },
96 };
97
98 /*
99 * This is meant to hold a *small* number of objects that you would
100 * want read_sha1_file() to be able to return, but yet you do not want
101 * to write them into the object store (e.g. a browse-only
102 * application).
103 */
104 static struct cached_object {
105 unsigned char sha1[20];
106 enum object_type type;
107 void *buf;
108 unsigned long size;
109 } *cached_objects;
110 static int cached_object_nr, cached_object_alloc;
111
112 static struct cached_object empty_tree = {
113 EMPTY_TREE_SHA1_BIN_LITERAL,
114 OBJ_TREE,
115 "",
116 0
117 };
118
119 static struct cached_object *find_cached_object(const unsigned char *sha1)
120 {
121 int i;
122 struct cached_object *co = cached_objects;
123
124 for (i = 0; i < cached_object_nr; i++, co++) {
125 if (!hashcmp(co->sha1, sha1))
126 return co;
127 }
128 if (!hashcmp(sha1, empty_tree.sha1))
129 return &empty_tree;
130 return NULL;
131 }
132
133
134 static int get_conv_flags(unsigned flags)
135 {
136 if (flags & HASH_RENORMALIZE)
137 return CONV_EOL_RENORMALIZE;
138 else if (flags & HASH_WRITE_OBJECT)
139 return global_conv_flags_eol;
140 else
141 return 0;
142 }
143
144
145 int mkdir_in_gitdir(const char *path)
146 {
147 if (mkdir(path, 0777)) {
148 int saved_errno = errno;
149 struct stat st;
150 struct strbuf sb = STRBUF_INIT;
151
152 if (errno != EEXIST)
153 return -1;
154 /*
155 * Are we looking at a path in a symlinked worktree
156 * whose original repository does not yet have it?
157 * e.g. .git/rr-cache pointing at its original
158 * repository in which the user hasn't performed any
159 * conflict resolution yet?
160 */
161 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
162 strbuf_readlink(&sb, path, st.st_size) ||
163 !is_absolute_path(sb.buf) ||
164 mkdir(sb.buf, 0777)) {
165 strbuf_release(&sb);
166 errno = saved_errno;
167 return -1;
168 }
169 strbuf_release(&sb);
170 }
171 return adjust_shared_perm(path);
172 }
173
174 enum scld_error safe_create_leading_directories(char *path)
175 {
176 char *next_component = path + offset_1st_component(path);
177 enum scld_error ret = SCLD_OK;
178
179 while (ret == SCLD_OK && next_component) {
180 struct stat st;
181 char *slash = next_component, slash_character;
182
183 while (*slash && !is_dir_sep(*slash))
184 slash++;
185
186 if (!*slash)
187 break;
188
189 next_component = slash + 1;
190 while (is_dir_sep(*next_component))
191 next_component++;
192 if (!*next_component)
193 break;
194
195 slash_character = *slash;
196 *slash = '\0';
197 if (!stat(path, &st)) {
198 /* path exists */
199 if (!S_ISDIR(st.st_mode)) {
200 errno = ENOTDIR;
201 ret = SCLD_EXISTS;
202 }
203 } else if (mkdir(path, 0777)) {
204 if (errno == EEXIST &&
205 !stat(path, &st) && S_ISDIR(st.st_mode))
206 ; /* somebody created it since we checked */
207 else if (errno == ENOENT)
208 /*
209 * Either mkdir() failed because
210 * somebody just pruned the containing
211 * directory, or stat() failed because
212 * the file that was in our way was
213 * just removed. Either way, inform
214 * the caller that it might be worth
215 * trying again:
216 */
217 ret = SCLD_VANISHED;
218 else
219 ret = SCLD_FAILED;
220 } else if (adjust_shared_perm(path)) {
221 ret = SCLD_PERMS;
222 }
223 *slash = slash_character;
224 }
225 return ret;
226 }
227
228 enum scld_error safe_create_leading_directories_const(const char *path)
229 {
230 int save_errno;
231 /* path points to cache entries, so xstrdup before messing with it */
232 char *buf = xstrdup(path);
233 enum scld_error result = safe_create_leading_directories(buf);
234
235 save_errno = errno;
236 free(buf);
237 errno = save_errno;
238 return result;
239 }
240
241 int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
242 {
243 /*
244 * The number of times we will try to remove empty directories
245 * in the way of path. This is only 1 because if another
246 * process is racily creating directories that conflict with
247 * us, we don't want to fight against them.
248 */
249 int remove_directories_remaining = 1;
250
251 /*
252 * The number of times that we will try to create the
253 * directories containing path. We are willing to attempt this
254 * more than once, because another process could be trying to
255 * clean up empty directories at the same time as we are
256 * trying to create them.
257 */
258 int create_directories_remaining = 3;
259
260 /* A scratch copy of path, filled lazily if we need it: */
261 struct strbuf path_copy = STRBUF_INIT;
262
263 int ret, save_errno;
264
265 /* Sanity check: */
266 assert(*path);
267
268 retry_fn:
269 ret = fn(path, cb);
270 save_errno = errno;
271 if (!ret)
272 goto out;
273
274 if (errno == EISDIR && remove_directories_remaining-- > 0) {
275 /*
276 * A directory is in the way. Maybe it is empty; try
277 * to remove it:
278 */
279 if (!path_copy.len)
280 strbuf_addstr(&path_copy, path);
281
282 if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
283 goto retry_fn;
284 } else if (errno == ENOENT && create_directories_remaining-- > 0) {
285 /*
286 * Maybe the containing directory didn't exist, or
287 * maybe it was just deleted by a process that is
288 * racing with us to clean up empty directories. Try
289 * to create it:
290 */
291 enum scld_error scld_result;
292
293 if (!path_copy.len)
294 strbuf_addstr(&path_copy, path);
295
296 do {
297 scld_result = safe_create_leading_directories(path_copy.buf);
298 if (scld_result == SCLD_OK)
299 goto retry_fn;
300 } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
301 }
302
303 out:
304 strbuf_release(&path_copy);
305 errno = save_errno;
306 return ret;
307 }
308
309 static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
310 {
311 int i;
312 for (i = 0; i < 20; i++) {
313 static char hex[] = "0123456789abcdef";
314 unsigned int val = sha1[i];
315 strbuf_addch(buf, hex[val >> 4]);
316 strbuf_addch(buf, hex[val & 0xf]);
317 if (!i)
318 strbuf_addch(buf, '/');
319 }
320 }
321
322 void sha1_file_name(struct strbuf *buf, const unsigned char *sha1)
323 {
324 strbuf_addstr(buf, get_object_directory());
325 strbuf_addch(buf, '/');
326 fill_sha1_path(buf, sha1);
327 }
328
329 struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
330 {
331 strbuf_setlen(&alt->scratch, alt->base_len);
332 return &alt->scratch;
333 }
334
335 static const char *alt_sha1_path(struct alternate_object_database *alt,
336 const unsigned char *sha1)
337 {
338 struct strbuf *buf = alt_scratch_buf(alt);
339 fill_sha1_path(buf, sha1);
340 return buf->buf;
341 }
342
343 struct alternate_object_database *alt_odb_list;
344 static struct alternate_object_database **alt_odb_tail;
345
346 /*
347 * Return non-zero iff the path is usable as an alternate object database.
348 */
349 static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
350 {
351 struct alternate_object_database *alt;
352
353 /* Detect cases where alternate disappeared */
354 if (!is_directory(path->buf)) {
355 error("object directory %s does not exist; "
356 "check .git/objects/info/alternates.",
357 path->buf);
358 return 0;
359 }
360
361 /*
362 * Prevent the common mistake of listing the same
363 * thing twice, or object directory itself.
364 */
365 for (alt = alt_odb_list; alt; alt = alt->next) {
366 if (!fspathcmp(path->buf, alt->path))
367 return 0;
368 }
369 if (!fspathcmp(path->buf, normalized_objdir))
370 return 0;
371
372 return 1;
373 }
374
375 /*
376 * Prepare alternate object database registry.
377 *
378 * The variable alt_odb_list points at the list of struct
379 * alternate_object_database. The elements on this list come from
380 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
381 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
382 * whose contents is similar to that environment variable but can be
383 * LF separated. Its base points at a statically allocated buffer that
384 * contains "/the/directory/corresponding/to/.git/objects/...", while
385 * its name points just after the slash at the end of ".git/objects/"
386 * in the example above, and has enough space to hold 40-byte hex
387 * SHA1, an extra slash for the first level indirection, and the
388 * terminating NUL.
389 */
390 static void read_info_alternates(const char * relative_base, int depth);
391 static int link_alt_odb_entry(const char *entry, const char *relative_base,
392 int depth, const char *normalized_objdir)
393 {
394 struct alternate_object_database *ent;
395 struct strbuf pathbuf = STRBUF_INIT;
396
397 if (!is_absolute_path(entry) && relative_base) {
398 strbuf_realpath(&pathbuf, relative_base, 1);
399 strbuf_addch(&pathbuf, '/');
400 }
401 strbuf_addstr(&pathbuf, entry);
402
403 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
404 error("unable to normalize alternate object path: %s",
405 pathbuf.buf);
406 strbuf_release(&pathbuf);
407 return -1;
408 }
409
410 /*
411 * The trailing slash after the directory name is given by
412 * this function at the end. Remove duplicates.
413 */
414 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
415 strbuf_setlen(&pathbuf, pathbuf.len - 1);
416
417 if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
418 strbuf_release(&pathbuf);
419 return -1;
420 }
421
422 ent = alloc_alt_odb(pathbuf.buf);
423
424 /* add the alternate entry */
425 *alt_odb_tail = ent;
426 alt_odb_tail = &(ent->next);
427 ent->next = NULL;
428
429 /* recursively add alternates */
430 read_info_alternates(pathbuf.buf, depth + 1);
431
432 strbuf_release(&pathbuf);
433 return 0;
434 }
435
436 static const char *parse_alt_odb_entry(const char *string,
437 int sep,
438 struct strbuf *out)
439 {
440 const char *end;
441
442 strbuf_reset(out);
443
444 if (*string == '#') {
445 /* comment; consume up to next separator */
446 end = strchrnul(string, sep);
447 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
448 /*
449 * quoted path; unquote_c_style has copied the
450 * data for us and set "end". Broken quoting (e.g.,
451 * an entry that doesn't end with a quote) falls
452 * back to the unquoted case below.
453 */
454 } else {
455 /* normal, unquoted path */
456 end = strchrnul(string, sep);
457 strbuf_add(out, string, end - string);
458 }
459
460 if (*end)
461 end++;
462 return end;
463 }
464
465 static void link_alt_odb_entries(const char *alt, int sep,
466 const char *relative_base, int depth)
467 {
468 struct strbuf objdirbuf = STRBUF_INIT;
469 struct strbuf entry = STRBUF_INIT;
470
471 if (!alt || !*alt)
472 return;
473
474 if (depth > 5) {
475 error("%s: ignoring alternate object stores, nesting too deep.",
476 relative_base);
477 return;
478 }
479
480 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
481 if (strbuf_normalize_path(&objdirbuf) < 0)
482 die("unable to normalize object directory: %s",
483 objdirbuf.buf);
484
485 while (*alt) {
486 alt = parse_alt_odb_entry(alt, sep, &entry);
487 if (!entry.len)
488 continue;
489 link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
490 }
491 strbuf_release(&entry);
492 strbuf_release(&objdirbuf);
493 }
494
495 static void read_info_alternates(const char * relative_base, int depth)
496 {
497 char *path;
498 struct strbuf buf = STRBUF_INIT;
499
500 path = xstrfmt("%s/info/alternates", relative_base);
501 if (strbuf_read_file(&buf, path, 1024) < 0) {
502 warn_on_fopen_errors(path);
503 free(path);
504 return;
505 }
506
507 link_alt_odb_entries(buf.buf, '\n', relative_base, depth);
508 strbuf_release(&buf);
509 free(path);
510 }
511
512 struct alternate_object_database *alloc_alt_odb(const char *dir)
513 {
514 struct alternate_object_database *ent;
515
516 FLEX_ALLOC_STR(ent, path, dir);
517 strbuf_init(&ent->scratch, 0);
518 strbuf_addf(&ent->scratch, "%s/", dir);
519 ent->base_len = ent->scratch.len;
520
521 return ent;
522 }
523
524 void add_to_alternates_file(const char *reference)
525 {
526 struct lock_file lock = LOCK_INIT;
527 char *alts = git_pathdup("objects/info/alternates");
528 FILE *in, *out;
529 int found = 0;
530
531 hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
532 out = fdopen_lock_file(&lock, "w");
533 if (!out)
534 die_errno("unable to fdopen alternates lockfile");
535
536 in = fopen(alts, "r");
537 if (in) {
538 struct strbuf line = STRBUF_INIT;
539
540 while (strbuf_getline(&line, in) != EOF) {
541 if (!strcmp(reference, line.buf)) {
542 found = 1;
543 break;
544 }
545 fprintf_or_die(out, "%s\n", line.buf);
546 }
547
548 strbuf_release(&line);
549 fclose(in);
550 }
551 else if (errno != ENOENT)
552 die_errno("unable to read alternates file");
553
554 if (found) {
555 rollback_lock_file(&lock);
556 } else {
557 fprintf_or_die(out, "%s\n", reference);
558 if (commit_lock_file(&lock))
559 die_errno("unable to move new alternates file into place");
560 if (alt_odb_tail)
561 link_alt_odb_entries(reference, '\n', NULL, 0);
562 }
563 free(alts);
564 }
565
566 void add_to_alternates_memory(const char *reference)
567 {
568 /*
569 * Make sure alternates are initialized, or else our entry may be
570 * overwritten when they are.
571 */
572 prepare_alt_odb();
573
574 link_alt_odb_entries(reference, '\n', NULL, 0);
575 }
576
577 /*
578 * Compute the exact path an alternate is at and returns it. In case of
579 * error NULL is returned and the human readable error is added to `err`
580 * `path` may be relative and should point to $GITDIR.
581 * `err` must not be null.
582 */
583 char *compute_alternate_path(const char *path, struct strbuf *err)
584 {
585 char *ref_git = NULL;
586 const char *repo, *ref_git_s;
587 int seen_error = 0;
588
589 ref_git_s = real_path_if_valid(path);
590 if (!ref_git_s) {
591 seen_error = 1;
592 strbuf_addf(err, _("path '%s' does not exist"), path);
593 goto out;
594 } else
595 /*
596 * Beware: read_gitfile(), real_path() and mkpath()
597 * return static buffer
598 */
599 ref_git = xstrdup(ref_git_s);
600
601 repo = read_gitfile(ref_git);
602 if (!repo)
603 repo = read_gitfile(mkpath("%s/.git", ref_git));
604 if (repo) {
605 free(ref_git);
606 ref_git = xstrdup(repo);
607 }
608
609 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
610 char *ref_git_git = mkpathdup("%s/.git", ref_git);
611 free(ref_git);
612 ref_git = ref_git_git;
613 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
614 struct strbuf sb = STRBUF_INIT;
615 seen_error = 1;
616 if (get_common_dir(&sb, ref_git)) {
617 strbuf_addf(err,
618 _("reference repository '%s' as a linked "
619 "checkout is not supported yet."),
620 path);
621 goto out;
622 }
623
624 strbuf_addf(err, _("reference repository '%s' is not a "
625 "local repository."), path);
626 goto out;
627 }
628
629 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
630 strbuf_addf(err, _("reference repository '%s' is shallow"),
631 path);
632 seen_error = 1;
633 goto out;
634 }
635
636 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
637 strbuf_addf(err,
638 _("reference repository '%s' is grafted"),
639 path);
640 seen_error = 1;
641 goto out;
642 }
643
644 out:
645 if (seen_error) {
646 FREE_AND_NULL(ref_git);
647 }
648
649 return ref_git;
650 }
651
652 int foreach_alt_odb(alt_odb_fn fn, void *cb)
653 {
654 struct alternate_object_database *ent;
655 int r = 0;
656
657 prepare_alt_odb();
658 for (ent = alt_odb_list; ent; ent = ent->next) {
659 r = fn(ent, cb);
660 if (r)
661 break;
662 }
663 return r;
664 }
665
666 void prepare_alt_odb(void)
667 {
668 const char *alt;
669
670 if (alt_odb_tail)
671 return;
672
673 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
674
675 alt_odb_tail = &alt_odb_list;
676 link_alt_odb_entries(alt, PATH_SEP, NULL, 0);
677
678 read_info_alternates(get_object_directory(), 0);
679 }
680
681 /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
682 static int freshen_file(const char *fn)
683 {
684 struct utimbuf t;
685 t.actime = t.modtime = time(NULL);
686 return !utime(fn, &t);
687 }
688
689 /*
690 * All of the check_and_freshen functions return 1 if the file exists and was
691 * freshened (if freshening was requested), 0 otherwise. If they return
692 * 0, you should not assume that it is safe to skip a write of the object (it
693 * either does not exist on disk, or has a stale mtime and may be subject to
694 * pruning).
695 */
696 int check_and_freshen_file(const char *fn, int freshen)
697 {
698 if (access(fn, F_OK))
699 return 0;
700 if (freshen && !freshen_file(fn))
701 return 0;
702 return 1;
703 }
704
705 static int check_and_freshen_local(const unsigned char *sha1, int freshen)
706 {
707 static struct strbuf buf = STRBUF_INIT;
708
709 strbuf_reset(&buf);
710 sha1_file_name(&buf, sha1);
711
712 return check_and_freshen_file(buf.buf, freshen);
713 }
714
715 static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
716 {
717 struct alternate_object_database *alt;
718 prepare_alt_odb();
719 for (alt = alt_odb_list; alt; alt = alt->next) {
720 const char *path = alt_sha1_path(alt, sha1);
721 if (check_and_freshen_file(path, freshen))
722 return 1;
723 }
724 return 0;
725 }
726
727 static int check_and_freshen(const unsigned char *sha1, int freshen)
728 {
729 return check_and_freshen_local(sha1, freshen) ||
730 check_and_freshen_nonlocal(sha1, freshen);
731 }
732
733 int has_loose_object_nonlocal(const unsigned char *sha1)
734 {
735 return check_and_freshen_nonlocal(sha1, 0);
736 }
737
738 static int has_loose_object(const unsigned char *sha1)
739 {
740 return check_and_freshen(sha1, 0);
741 }
742
743 static void mmap_limit_check(size_t length)
744 {
745 static size_t limit = 0;
746 if (!limit) {
747 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
748 if (!limit)
749 limit = SIZE_MAX;
750 }
751 if (length > limit)
752 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
753 (uintmax_t)length, (uintmax_t)limit);
754 }
755
756 void *xmmap_gently(void *start, size_t length,
757 int prot, int flags, int fd, off_t offset)
758 {
759 void *ret;
760
761 mmap_limit_check(length);
762 ret = mmap(start, length, prot, flags, fd, offset);
763 if (ret == MAP_FAILED) {
764 if (!length)
765 return NULL;
766 release_pack_memory(length);
767 ret = mmap(start, length, prot, flags, fd, offset);
768 }
769 return ret;
770 }
771
772 void *xmmap(void *start, size_t length,
773 int prot, int flags, int fd, off_t offset)
774 {
775 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
776 if (ret == MAP_FAILED)
777 die_errno("mmap failed");
778 return ret;
779 }
780
781 /*
782 * With an in-core object data in "map", rehash it to make sure the
783 * object name actually matches "sha1" to detect object corruption.
784 * With "map" == NULL, try reading the object named with "sha1" using
785 * the streaming interface and rehash it to do the same.
786 */
787 int check_sha1_signature(const unsigned char *sha1, void *map,
788 unsigned long size, const char *type)
789 {
790 struct object_id real_oid;
791 enum object_type obj_type;
792 struct git_istream *st;
793 git_hash_ctx c;
794 char hdr[32];
795 int hdrlen;
796
797 if (map) {
798 hash_object_file(map, size, type, &real_oid);
799 return hashcmp(sha1, real_oid.hash) ? -1 : 0;
800 }
801
802 st = open_istream(sha1, &obj_type, &size, NULL);
803 if (!st)
804 return -1;
805
806 /* Generate the header */
807 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(obj_type), size) + 1;
808
809 /* Sha1.. */
810 the_hash_algo->init_fn(&c);
811 the_hash_algo->update_fn(&c, hdr, hdrlen);
812 for (;;) {
813 char buf[1024 * 16];
814 ssize_t readlen = read_istream(st, buf, sizeof(buf));
815
816 if (readlen < 0) {
817 close_istream(st);
818 return -1;
819 }
820 if (!readlen)
821 break;
822 the_hash_algo->update_fn(&c, buf, readlen);
823 }
824 the_hash_algo->final_fn(real_oid.hash, &c);
825 close_istream(st);
826 return hashcmp(sha1, real_oid.hash) ? -1 : 0;
827 }
828
829 int git_open_cloexec(const char *name, int flags)
830 {
831 int fd;
832 static int o_cloexec = O_CLOEXEC;
833
834 fd = open(name, flags | o_cloexec);
835 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
836 /* Try again w/o O_CLOEXEC: the kernel might not support it */
837 o_cloexec &= ~O_CLOEXEC;
838 fd = open(name, flags | o_cloexec);
839 }
840
841 #if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
842 {
843 static int fd_cloexec = FD_CLOEXEC;
844
845 if (!o_cloexec && 0 <= fd && fd_cloexec) {
846 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
847 int flags = fcntl(fd, F_GETFD);
848 if (fcntl(fd, F_SETFD, flags | fd_cloexec))
849 fd_cloexec = 0;
850 }
851 }
852 #endif
853 return fd;
854 }
855
856 /*
857 * Find "sha1" as a loose object in the local repository or in an alternate.
858 * Returns 0 on success, negative on failure.
859 *
860 * The "path" out-parameter will give the path of the object we found (if any).
861 * Note that it may point to static storage and is only valid until another
862 * call to sha1_file_name(), etc.
863 */
864 static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
865 const char **path)
866 {
867 struct alternate_object_database *alt;
868 static struct strbuf buf = STRBUF_INIT;
869
870 strbuf_reset(&buf);
871 sha1_file_name(&buf, sha1);
872 *path = buf.buf;
873
874 if (!lstat(*path, st))
875 return 0;
876
877 prepare_alt_odb();
878 errno = ENOENT;
879 for (alt = alt_odb_list; alt; alt = alt->next) {
880 *path = alt_sha1_path(alt, sha1);
881 if (!lstat(*path, st))
882 return 0;
883 }
884
885 return -1;
886 }
887
888 /*
889 * Like stat_sha1_file(), but actually open the object and return the
890 * descriptor. See the caveats on the "path" parameter above.
891 */
892 static int open_sha1_file(const unsigned char *sha1, const char **path)
893 {
894 int fd;
895 struct alternate_object_database *alt;
896 int most_interesting_errno;
897 static struct strbuf buf = STRBUF_INIT;
898
899 strbuf_reset(&buf);
900 sha1_file_name(&buf, sha1);
901 *path = buf.buf;
902
903 fd = git_open(*path);
904 if (fd >= 0)
905 return fd;
906 most_interesting_errno = errno;
907
908 prepare_alt_odb();
909 for (alt = alt_odb_list; alt; alt = alt->next) {
910 *path = alt_sha1_path(alt, sha1);
911 fd = git_open(*path);
912 if (fd >= 0)
913 return fd;
914 if (most_interesting_errno == ENOENT)
915 most_interesting_errno = errno;
916 }
917 errno = most_interesting_errno;
918 return -1;
919 }
920
921 /*
922 * Map the loose object at "path" if it is not NULL, or the path found by
923 * searching for a loose object named "sha1".
924 */
925 static void *map_sha1_file_1(const char *path,
926 const unsigned char *sha1,
927 unsigned long *size)
928 {
929 void *map;
930 int fd;
931
932 if (path)
933 fd = git_open(path);
934 else
935 fd = open_sha1_file(sha1, &path);
936 map = NULL;
937 if (fd >= 0) {
938 struct stat st;
939
940 if (!fstat(fd, &st)) {
941 *size = xsize_t(st.st_size);
942 if (!*size) {
943 /* mmap() is forbidden on empty files */
944 error("object file %s is empty", path);
945 return NULL;
946 }
947 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
948 }
949 close(fd);
950 }
951 return map;
952 }
953
954 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
955 {
956 return map_sha1_file_1(NULL, sha1, size);
957 }
958
959 static int unpack_sha1_short_header(git_zstream *stream,
960 unsigned char *map, unsigned long mapsize,
961 void *buffer, unsigned long bufsiz)
962 {
963 /* Get the data stream */
964 memset(stream, 0, sizeof(*stream));
965 stream->next_in = map;
966 stream->avail_in = mapsize;
967 stream->next_out = buffer;
968 stream->avail_out = bufsiz;
969
970 git_inflate_init(stream);
971 return git_inflate(stream, 0);
972 }
973
974 int unpack_sha1_header(git_zstream *stream,
975 unsigned char *map, unsigned long mapsize,
976 void *buffer, unsigned long bufsiz)
977 {
978 int status = unpack_sha1_short_header(stream, map, mapsize,
979 buffer, bufsiz);
980
981 if (status < Z_OK)
982 return status;
983
984 /* Make sure we have the terminating NUL */
985 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
986 return -1;
987 return 0;
988 }
989
990 static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
991 unsigned long mapsize, void *buffer,
992 unsigned long bufsiz, struct strbuf *header)
993 {
994 int status;
995
996 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
997 if (status < Z_OK)
998 return -1;
999
1000 /*
1001 * Check if entire header is unpacked in the first iteration.
1002 */
1003 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1004 return 0;
1005
1006 /*
1007 * buffer[0..bufsiz] was not large enough. Copy the partial
1008 * result out to header, and then append the result of further
1009 * reading the stream.
1010 */
1011 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1012 stream->next_out = buffer;
1013 stream->avail_out = bufsiz;
1014
1015 do {
1016 status = git_inflate(stream, 0);
1017 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1018 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1019 return 0;
1020 stream->next_out = buffer;
1021 stream->avail_out = bufsiz;
1022 } while (status != Z_STREAM_END);
1023 return -1;
1024 }
1025
1026 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1027 {
1028 int bytes = strlen(buffer) + 1;
1029 unsigned char *buf = xmallocz(size);
1030 unsigned long n;
1031 int status = Z_OK;
1032
1033 n = stream->total_out - bytes;
1034 if (n > size)
1035 n = size;
1036 memcpy(buf, (char *) buffer + bytes, n);
1037 bytes = n;
1038 if (bytes <= size) {
1039 /*
1040 * The above condition must be (bytes <= size), not
1041 * (bytes < size). In other words, even though we
1042 * expect no more output and set avail_out to zero,
1043 * the input zlib stream may have bytes that express
1044 * "this concludes the stream", and we *do* want to
1045 * eat that input.
1046 *
1047 * Otherwise we would not be able to test that we
1048 * consumed all the input to reach the expected size;
1049 * we also want to check that zlib tells us that all
1050 * went well with status == Z_STREAM_END at the end.
1051 */
1052 stream->next_out = buf + bytes;
1053 stream->avail_out = size - bytes;
1054 while (status == Z_OK)
1055 status = git_inflate(stream, Z_FINISH);
1056 }
1057 if (status == Z_STREAM_END && !stream->avail_in) {
1058 git_inflate_end(stream);
1059 return buf;
1060 }
1061
1062 if (status < 0)
1063 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1064 else if (stream->avail_in)
1065 error("garbage at end of loose object '%s'",
1066 sha1_to_hex(sha1));
1067 free(buf);
1068 return NULL;
1069 }
1070
1071 /*
1072 * We used to just use "sscanf()", but that's actually way
1073 * too permissive for what we want to check. So do an anal
1074 * object header parse by hand.
1075 */
1076 static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1077 unsigned int flags)
1078 {
1079 const char *type_buf = hdr;
1080 unsigned long size;
1081 int type, type_len = 0;
1082
1083 /*
1084 * The type can be of any size but is followed by
1085 * a space.
1086 */
1087 for (;;) {
1088 char c = *hdr++;
1089 if (!c)
1090 return -1;
1091 if (c == ' ')
1092 break;
1093 type_len++;
1094 }
1095
1096 type = type_from_string_gently(type_buf, type_len, 1);
1097 if (oi->type_name)
1098 strbuf_add(oi->type_name, type_buf, type_len);
1099 /*
1100 * Set type to 0 if its an unknown object and
1101 * we're obtaining the type using '--allow-unknown-type'
1102 * option.
1103 */
1104 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
1105 type = 0;
1106 else if (type < 0)
1107 die("invalid object type");
1108 if (oi->typep)
1109 *oi->typep = type;
1110
1111 /*
1112 * The length must follow immediately, and be in canonical
1113 * decimal format (ie "010" is not valid).
1114 */
1115 size = *hdr++ - '0';
1116 if (size > 9)
1117 return -1;
1118 if (size) {
1119 for (;;) {
1120 unsigned long c = *hdr - '0';
1121 if (c > 9)
1122 break;
1123 hdr++;
1124 size = size * 10 + c;
1125 }
1126 }
1127
1128 if (oi->sizep)
1129 *oi->sizep = size;
1130
1131 /*
1132 * The length must be followed by a zero byte
1133 */
1134 return *hdr ? -1 : type;
1135 }
1136
1137 int parse_sha1_header(const char *hdr, unsigned long *sizep)
1138 {
1139 struct object_info oi = OBJECT_INFO_INIT;
1140
1141 oi.sizep = sizep;
1142 return parse_sha1_header_extended(hdr, &oi, 0);
1143 }
1144
1145 static int sha1_loose_object_info(const unsigned char *sha1,
1146 struct object_info *oi,
1147 int flags)
1148 {
1149 int status = 0;
1150 unsigned long mapsize;
1151 void *map;
1152 git_zstream stream;
1153 char hdr[32];
1154 struct strbuf hdrbuf = STRBUF_INIT;
1155 unsigned long size_scratch;
1156
1157 if (oi->delta_base_sha1)
1158 hashclr(oi->delta_base_sha1);
1159
1160 /*
1161 * If we don't care about type or size, then we don't
1162 * need to look inside the object at all. Note that we
1163 * do not optimize out the stat call, even if the
1164 * caller doesn't care about the disk-size, since our
1165 * return value implicitly indicates whether the
1166 * object even exists.
1167 */
1168 if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
1169 const char *path;
1170 struct stat st;
1171 if (stat_sha1_file(sha1, &st, &path) < 0)
1172 return -1;
1173 if (oi->disk_sizep)
1174 *oi->disk_sizep = st.st_size;
1175 return 0;
1176 }
1177
1178 map = map_sha1_file(sha1, &mapsize);
1179 if (!map)
1180 return -1;
1181
1182 if (!oi->sizep)
1183 oi->sizep = &size_scratch;
1184
1185 if (oi->disk_sizep)
1186 *oi->disk_sizep = mapsize;
1187 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
1188 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
1189 status = error("unable to unpack %s header with --allow-unknown-type",
1190 sha1_to_hex(sha1));
1191 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1192 status = error("unable to unpack %s header",
1193 sha1_to_hex(sha1));
1194 if (status < 0)
1195 ; /* Do nothing */
1196 else if (hdrbuf.len) {
1197 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
1198 status = error("unable to parse %s header with --allow-unknown-type",
1199 sha1_to_hex(sha1));
1200 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
1201 status = error("unable to parse %s header", sha1_to_hex(sha1));
1202
1203 if (status >= 0 && oi->contentp) {
1204 *oi->contentp = unpack_sha1_rest(&stream, hdr,
1205 *oi->sizep, sha1);
1206 if (!*oi->contentp) {
1207 git_inflate_end(&stream);
1208 status = -1;
1209 }
1210 } else
1211 git_inflate_end(&stream);
1212
1213 munmap(map, mapsize);
1214 if (status && oi->typep)
1215 *oi->typep = status;
1216 if (oi->sizep == &size_scratch)
1217 oi->sizep = NULL;
1218 strbuf_release(&hdrbuf);
1219 oi->whence = OI_LOOSE;
1220 return (status < 0) ? status : 0;
1221 }
1222
1223 int fetch_if_missing = 1;
1224
1225 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
1226 {
1227 static struct object_info blank_oi = OBJECT_INFO_INIT;
1228 struct pack_entry e;
1229 int rtype;
1230 const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ?
1231 lookup_replace_object(sha1) :
1232 sha1;
1233 int already_retried = 0;
1234
1235 if (is_null_sha1(real))
1236 return -1;
1237
1238 if (!oi)
1239 oi = &blank_oi;
1240
1241 if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
1242 struct cached_object *co = find_cached_object(real);
1243 if (co) {
1244 if (oi->typep)
1245 *(oi->typep) = co->type;
1246 if (oi->sizep)
1247 *(oi->sizep) = co->size;
1248 if (oi->disk_sizep)
1249 *(oi->disk_sizep) = 0;
1250 if (oi->delta_base_sha1)
1251 hashclr(oi->delta_base_sha1);
1252 if (oi->type_name)
1253 strbuf_addstr(oi->type_name, type_name(co->type));
1254 if (oi->contentp)
1255 *oi->contentp = xmemdupz(co->buf, co->size);
1256 oi->whence = OI_CACHED;
1257 return 0;
1258 }
1259 }
1260
1261 while (1) {
1262 if (find_pack_entry(real, &e))
1263 break;
1264
1265 /* Most likely it's a loose object. */
1266 if (!sha1_loose_object_info(real, oi, flags))
1267 return 0;
1268
1269 /* Not a loose object; someone else may have just packed it. */
1270 reprepare_packed_git();
1271 if (find_pack_entry(real, &e))
1272 break;
1273
1274 /* Check if it is a missing object */
1275 if (fetch_if_missing && repository_format_partial_clone &&
1276 !already_retried) {
1277 /*
1278 * TODO Investigate haveing fetch_object() return
1279 * TODO error/success and stopping the music here.
1280 */
1281 fetch_object(repository_format_partial_clone, real);
1282 already_retried = 1;
1283 continue;
1284 }
1285
1286 return -1;
1287 }
1288
1289 if (oi == &blank_oi)
1290 /*
1291 * We know that the caller doesn't actually need the
1292 * information below, so return early.
1293 */
1294 return 0;
1295 rtype = packed_object_info(e.p, e.offset, oi);
1296 if (rtype < 0) {
1297 mark_bad_packed_object(e.p, real);
1298 return sha1_object_info_extended(real, oi, 0);
1299 } else if (oi->whence == OI_PACKED) {
1300 oi->u.packed.offset = e.offset;
1301 oi->u.packed.pack = e.p;
1302 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
1303 rtype == OBJ_OFS_DELTA);
1304 }
1305
1306 return 0;
1307 }
1308
1309 /* returns enum object_type or negative */
1310 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1311 {
1312 enum object_type type;
1313 struct object_info oi = OBJECT_INFO_INIT;
1314
1315 oi.typep = &type;
1316 oi.sizep = sizep;
1317 if (sha1_object_info_extended(sha1, &oi,
1318 OBJECT_INFO_LOOKUP_REPLACE) < 0)
1319 return -1;
1320 return type;
1321 }
1322
1323 static void *read_object(const unsigned char *sha1, enum object_type *type,
1324 unsigned long *size)
1325 {
1326 struct object_info oi = OBJECT_INFO_INIT;
1327 void *content;
1328 oi.typep = type;
1329 oi.sizep = size;
1330 oi.contentp = &content;
1331
1332 if (sha1_object_info_extended(sha1, &oi, 0) < 0)
1333 return NULL;
1334 return content;
1335 }
1336
1337 int pretend_object_file(void *buf, unsigned long len, enum object_type type,
1338 struct object_id *oid)
1339 {
1340 struct cached_object *co;
1341
1342 hash_object_file(buf, len, type_name(type), oid);
1343 if (has_sha1_file(oid->hash) || find_cached_object(oid->hash))
1344 return 0;
1345 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
1346 co = &cached_objects[cached_object_nr++];
1347 co->size = len;
1348 co->type = type;
1349 co->buf = xmalloc(len);
1350 memcpy(co->buf, buf, len);
1351 hashcpy(co->sha1, oid->hash);
1352 return 0;
1353 }
1354
1355 /*
1356 * This function dies on corrupt objects; the callers who want to
1357 * deal with them should arrange to call read_object() and give error
1358 * messages themselves.
1359 */
1360 void *read_sha1_file_extended(const unsigned char *sha1,
1361 enum object_type *type,
1362 unsigned long *size,
1363 int lookup_replace)
1364 {
1365 void *data;
1366 const struct packed_git *p;
1367 const char *path;
1368 struct stat st;
1369 const unsigned char *repl = lookup_replace ? lookup_replace_object(sha1)
1370 : sha1;
1371
1372 errno = 0;
1373 data = read_object(repl, type, size);
1374 if (data)
1375 return data;
1376
1377 if (errno && errno != ENOENT)
1378 die_errno("failed to read object %s", sha1_to_hex(sha1));
1379
1380 /* die if we replaced an object with one that does not exist */
1381 if (repl != sha1)
1382 die("replacement %s not found for %s",
1383 sha1_to_hex(repl), sha1_to_hex(sha1));
1384
1385 if (!stat_sha1_file(repl, &st, &path))
1386 die("loose object %s (stored in %s) is corrupt",
1387 sha1_to_hex(repl), path);
1388
1389 if ((p = has_packed_and_bad(repl)) != NULL)
1390 die("packed object %s (stored in %s) is corrupt",
1391 sha1_to_hex(repl), p->pack_name);
1392
1393 return NULL;
1394 }
1395
1396 void *read_object_with_reference(const unsigned char *sha1,
1397 const char *required_type_name,
1398 unsigned long *size,
1399 unsigned char *actual_sha1_return)
1400 {
1401 enum object_type type, required_type;
1402 void *buffer;
1403 unsigned long isize;
1404 unsigned char actual_sha1[20];
1405
1406 required_type = type_from_string(required_type_name);
1407 hashcpy(actual_sha1, sha1);
1408 while (1) {
1409 int ref_length = -1;
1410 const char *ref_type = NULL;
1411
1412 buffer = read_sha1_file(actual_sha1, &type, &isize);
1413 if (!buffer)
1414 return NULL;
1415 if (type == required_type) {
1416 *size = isize;
1417 if (actual_sha1_return)
1418 hashcpy(actual_sha1_return, actual_sha1);
1419 return buffer;
1420 }
1421 /* Handle references */
1422 else if (type == OBJ_COMMIT)
1423 ref_type = "tree ";
1424 else if (type == OBJ_TAG)
1425 ref_type = "object ";
1426 else {
1427 free(buffer);
1428 return NULL;
1429 }
1430 ref_length = strlen(ref_type);
1431
1432 if (ref_length + 40 > isize ||
1433 memcmp(buffer, ref_type, ref_length) ||
1434 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1435 free(buffer);
1436 return NULL;
1437 }
1438 free(buffer);
1439 /* Now we have the ID of the referred-to object in
1440 * actual_sha1. Check again. */
1441 }
1442 }
1443
1444 static void write_object_file_prepare(const void *buf, unsigned long len,
1445 const char *type, struct object_id *oid,
1446 char *hdr, int *hdrlen)
1447 {
1448 git_hash_ctx c;
1449
1450 /* Generate the header */
1451 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
1452
1453 /* Sha1.. */
1454 the_hash_algo->init_fn(&c);
1455 the_hash_algo->update_fn(&c, hdr, *hdrlen);
1456 the_hash_algo->update_fn(&c, buf, len);
1457 the_hash_algo->final_fn(oid->hash, &c);
1458 }
1459
1460 /*
1461 * Move the just written object into its final resting place.
1462 */
1463 int finalize_object_file(const char *tmpfile, const char *filename)
1464 {
1465 int ret = 0;
1466
1467 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
1468 goto try_rename;
1469 else if (link(tmpfile, filename))
1470 ret = errno;
1471
1472 /*
1473 * Coda hack - coda doesn't like cross-directory links,
1474 * so we fall back to a rename, which will mean that it
1475 * won't be able to check collisions, but that's not a
1476 * big deal.
1477 *
1478 * The same holds for FAT formatted media.
1479 *
1480 * When this succeeds, we just return. We have nothing
1481 * left to unlink.
1482 */
1483 if (ret && ret != EEXIST) {
1484 try_rename:
1485 if (!rename(tmpfile, filename))
1486 goto out;
1487 ret = errno;
1488 }
1489 unlink_or_warn(tmpfile);
1490 if (ret) {
1491 if (ret != EEXIST) {
1492 return error_errno("unable to write sha1 filename %s", filename);
1493 }
1494 /* FIXME!!! Collision check here ? */
1495 }
1496
1497 out:
1498 if (adjust_shared_perm(filename))
1499 return error("unable to set permission to '%s'", filename);
1500 return 0;
1501 }
1502
1503 static int write_buffer(int fd, const void *buf, size_t len)
1504 {
1505 if (write_in_full(fd, buf, len) < 0)
1506 return error_errno("file write error");
1507 return 0;
1508 }
1509
1510 int hash_object_file(const void *buf, unsigned long len, const char *type,
1511 struct object_id *oid)
1512 {
1513 char hdr[32];
1514 int hdrlen = sizeof(hdr);
1515 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1516 return 0;
1517 }
1518
1519 /* Finalize a file on disk, and close it. */
1520 static void close_sha1_file(int fd)
1521 {
1522 if (fsync_object_files)
1523 fsync_or_die(fd, "sha1 file");
1524 if (close(fd) != 0)
1525 die_errno("error when closing sha1 file");
1526 }
1527
1528 /* Size of directory component, including the ending '/' */
1529 static inline int directory_size(const char *filename)
1530 {
1531 const char *s = strrchr(filename, '/');
1532 if (!s)
1533 return 0;
1534 return s - filename + 1;
1535 }
1536
1537 /*
1538 * This creates a temporary file in the same directory as the final
1539 * 'filename'
1540 *
1541 * We want to avoid cross-directory filename renames, because those
1542 * can have problems on various filesystems (FAT, NFS, Coda).
1543 */
1544 static int create_tmpfile(struct strbuf *tmp, const char *filename)
1545 {
1546 int fd, dirlen = directory_size(filename);
1547
1548 strbuf_reset(tmp);
1549 strbuf_add(tmp, filename, dirlen);
1550 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
1551 fd = git_mkstemp_mode(tmp->buf, 0444);
1552 if (fd < 0 && dirlen && errno == ENOENT) {
1553 /*
1554 * Make sure the directory exists; note that the contents
1555 * of the buffer are undefined after mkstemp returns an
1556 * error, so we have to rewrite the whole buffer from
1557 * scratch.
1558 */
1559 strbuf_reset(tmp);
1560 strbuf_add(tmp, filename, dirlen - 1);
1561 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
1562 return -1;
1563 if (adjust_shared_perm(tmp->buf))
1564 return -1;
1565
1566 /* Try again */
1567 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
1568 fd = git_mkstemp_mode(tmp->buf, 0444);
1569 }
1570 return fd;
1571 }
1572
1573 static int write_loose_object(const struct object_id *oid, char *hdr,
1574 int hdrlen, const void *buf, unsigned long len,
1575 time_t mtime)
1576 {
1577 int fd, ret;
1578 unsigned char compressed[4096];
1579 git_zstream stream;
1580 git_hash_ctx c;
1581 struct object_id parano_oid;
1582 static struct strbuf tmp_file = STRBUF_INIT;
1583 static struct strbuf filename = STRBUF_INIT;
1584
1585 strbuf_reset(&filename);
1586 sha1_file_name(&filename, oid->hash);
1587
1588 fd = create_tmpfile(&tmp_file, filename.buf);
1589 if (fd < 0) {
1590 if (errno == EACCES)
1591 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
1592 else
1593 return error_errno("unable to create temporary file");
1594 }
1595
1596 /* Set it up */
1597 git_deflate_init(&stream, zlib_compression_level);
1598 stream.next_out = compressed;
1599 stream.avail_out = sizeof(compressed);
1600 the_hash_algo->init_fn(&c);
1601
1602 /* First header.. */
1603 stream.next_in = (unsigned char *)hdr;
1604 stream.avail_in = hdrlen;
1605 while (git_deflate(&stream, 0) == Z_OK)
1606 ; /* nothing */
1607 the_hash_algo->update_fn(&c, hdr, hdrlen);
1608
1609 /* Then the data itself.. */
1610 stream.next_in = (void *)buf;
1611 stream.avail_in = len;
1612 do {
1613 unsigned char *in0 = stream.next_in;
1614 ret = git_deflate(&stream, Z_FINISH);
1615 the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
1616 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
1617 die("unable to write sha1 file");
1618 stream.next_out = compressed;
1619 stream.avail_out = sizeof(compressed);
1620 } while (ret == Z_OK);
1621
1622 if (ret != Z_STREAM_END)
1623 die("unable to deflate new object %s (%d)", oid_to_hex(oid),
1624 ret);
1625 ret = git_deflate_end_gently(&stream);
1626 if (ret != Z_OK)
1627 die("deflateEnd on object %s failed (%d)", oid_to_hex(oid),
1628 ret);
1629 the_hash_algo->final_fn(parano_oid.hash, &c);
1630 if (oidcmp(oid, &parano_oid) != 0)
1631 die("confused by unstable object source data for %s",
1632 oid_to_hex(oid));
1633
1634 close_sha1_file(fd);
1635
1636 if (mtime) {
1637 struct utimbuf utb;
1638 utb.actime = mtime;
1639 utb.modtime = mtime;
1640 if (utime(tmp_file.buf, &utb) < 0)
1641 warning_errno("failed utime() on %s", tmp_file.buf);
1642 }
1643
1644 return finalize_object_file(tmp_file.buf, filename.buf);
1645 }
1646
1647 static int freshen_loose_object(const unsigned char *sha1)
1648 {
1649 return check_and_freshen(sha1, 1);
1650 }
1651
1652 static int freshen_packed_object(const unsigned char *sha1)
1653 {
1654 struct pack_entry e;
1655 if (!find_pack_entry(sha1, &e))
1656 return 0;
1657 if (e.p->freshened)
1658 return 1;
1659 if (!freshen_file(e.p->pack_name))
1660 return 0;
1661 e.p->freshened = 1;
1662 return 1;
1663 }
1664
1665 int write_object_file(const void *buf, unsigned long len, const char *type,
1666 struct object_id *oid)
1667 {
1668 char hdr[32];
1669 int hdrlen = sizeof(hdr);
1670
1671 /* Normally if we have it in the pack then we do not bother writing
1672 * it out into .git/objects/??/?{38} file.
1673 */
1674 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1675 if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
1676 return 0;
1677 return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
1678 }
1679
1680 int hash_object_file_literally(const void *buf, unsigned long len,
1681 const char *type, struct object_id *oid,
1682 unsigned flags)
1683 {
1684 char *header;
1685 int hdrlen, status = 0;
1686
1687 /* type string, SP, %lu of the length plus NUL must fit this */
1688 hdrlen = strlen(type) + 32;
1689 header = xmalloc(hdrlen);
1690 write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
1691
1692 if (!(flags & HASH_WRITE_OBJECT))
1693 goto cleanup;
1694 if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
1695 goto cleanup;
1696 status = write_loose_object(oid, header, hdrlen, buf, len, 0);
1697
1698 cleanup:
1699 free(header);
1700 return status;
1701 }
1702
1703 int force_object_loose(const struct object_id *oid, time_t mtime)
1704 {
1705 void *buf;
1706 unsigned long len;
1707 enum object_type type;
1708 char hdr[32];
1709 int hdrlen;
1710 int ret;
1711
1712 if (has_loose_object(oid->hash))
1713 return 0;
1714 buf = read_object(oid->hash, &type, &len);
1715 if (!buf)
1716 return error("cannot read sha1_file for %s", oid_to_hex(oid));
1717 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
1718 ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
1719 free(buf);
1720
1721 return ret;
1722 }
1723
1724 int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
1725 {
1726 if (!startup_info->have_repository)
1727 return 0;
1728 return sha1_object_info_extended(sha1, NULL,
1729 flags | OBJECT_INFO_SKIP_CACHED) >= 0;
1730 }
1731
1732 int has_object_file(const struct object_id *oid)
1733 {
1734 return has_sha1_file(oid->hash);
1735 }
1736
1737 int has_object_file_with_flags(const struct object_id *oid, int flags)
1738 {
1739 return has_sha1_file_with_flags(oid->hash, flags);
1740 }
1741
1742 static void check_tree(const void *buf, size_t size)
1743 {
1744 struct tree_desc desc;
1745 struct name_entry entry;
1746
1747 init_tree_desc(&desc, buf, size);
1748 while (tree_entry(&desc, &entry))
1749 /* do nothing
1750 * tree_entry() will die() on malformed entries */
1751 ;
1752 }
1753
1754 static void check_commit(const void *buf, size_t size)
1755 {
1756 struct commit c;
1757 memset(&c, 0, sizeof(c));
1758 if (parse_commit_buffer(&c, buf, size))
1759 die("corrupt commit");
1760 }
1761
1762 static void check_tag(const void *buf, size_t size)
1763 {
1764 struct tag t;
1765 memset(&t, 0, sizeof(t));
1766 if (parse_tag_buffer(&t, buf, size))
1767 die("corrupt tag");
1768 }
1769
1770 static int index_mem(struct object_id *oid, void *buf, size_t size,
1771 enum object_type type,
1772 const char *path, unsigned flags)
1773 {
1774 int ret, re_allocated = 0;
1775 int write_object = flags & HASH_WRITE_OBJECT;
1776
1777 if (!type)
1778 type = OBJ_BLOB;
1779
1780 /*
1781 * Convert blobs to git internal format
1782 */
1783 if ((type == OBJ_BLOB) && path) {
1784 struct strbuf nbuf = STRBUF_INIT;
1785 if (convert_to_git(&the_index, path, buf, size, &nbuf,
1786 get_conv_flags(flags))) {
1787 buf = strbuf_detach(&nbuf, &size);
1788 re_allocated = 1;
1789 }
1790 }
1791 if (flags & HASH_FORMAT_CHECK) {
1792 if (type == OBJ_TREE)
1793 check_tree(buf, size);
1794 if (type == OBJ_COMMIT)
1795 check_commit(buf, size);
1796 if (type == OBJ_TAG)
1797 check_tag(buf, size);
1798 }
1799
1800 if (write_object)
1801 ret = write_object_file(buf, size, type_name(type), oid);
1802 else
1803 ret = hash_object_file(buf, size, type_name(type), oid);
1804 if (re_allocated)
1805 free(buf);
1806 return ret;
1807 }
1808
1809 static int index_stream_convert_blob(struct object_id *oid, int fd,
1810 const char *path, unsigned flags)
1811 {
1812 int ret;
1813 const int write_object = flags & HASH_WRITE_OBJECT;
1814 struct strbuf sbuf = STRBUF_INIT;
1815
1816 assert(path);
1817 assert(would_convert_to_git_filter_fd(path));
1818
1819 convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
1820 get_conv_flags(flags));
1821
1822 if (write_object)
1823 ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1824 oid);
1825 else
1826 ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1827 oid);
1828 strbuf_release(&sbuf);
1829 return ret;
1830 }
1831
1832 static int index_pipe(struct object_id *oid, int fd, enum object_type type,
1833 const char *path, unsigned flags)
1834 {
1835 struct strbuf sbuf = STRBUF_INIT;
1836 int ret;
1837
1838 if (strbuf_read(&sbuf, fd, 4096) >= 0)
1839 ret = index_mem(oid, sbuf.buf, sbuf.len, type, path, flags);
1840 else
1841 ret = -1;
1842 strbuf_release(&sbuf);
1843 return ret;
1844 }
1845
1846 #define SMALL_FILE_SIZE (32*1024)
1847
1848 static int index_core(struct object_id *oid, int fd, size_t size,
1849 enum object_type type, const char *path,
1850 unsigned flags)
1851 {
1852 int ret;
1853
1854 if (!size) {
1855 ret = index_mem(oid, "", size, type, path, flags);
1856 } else if (size <= SMALL_FILE_SIZE) {
1857 char *buf = xmalloc(size);
1858 ssize_t read_result = read_in_full(fd, buf, size);
1859 if (read_result < 0)
1860 ret = error_errno("read error while indexing %s",
1861 path ? path : "<unknown>");
1862 else if (read_result != size)
1863 ret = error("short read while indexing %s",
1864 path ? path : "<unknown>");
1865 else
1866 ret = index_mem(oid, buf, size, type, path, flags);
1867 free(buf);
1868 } else {
1869 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1870 ret = index_mem(oid, buf, size, type, path, flags);
1871 munmap(buf, size);
1872 }
1873 return ret;
1874 }
1875
1876 /*
1877 * This creates one packfile per large blob unless bulk-checkin
1878 * machinery is "plugged".
1879 *
1880 * This also bypasses the usual "convert-to-git" dance, and that is on
1881 * purpose. We could write a streaming version of the converting
1882 * functions and insert that before feeding the data to fast-import
1883 * (or equivalent in-core API described above). However, that is
1884 * somewhat complicated, as we do not know the size of the filter
1885 * result, which we need to know beforehand when writing a git object.
1886 * Since the primary motivation for trying to stream from the working
1887 * tree file and to avoid mmaping it in core is to deal with large
1888 * binary blobs, they generally do not want to get any conversion, and
1889 * callers should avoid this code path when filters are requested.
1890 */
1891 static int index_stream(struct object_id *oid, int fd, size_t size,
1892 enum object_type type, const char *path,
1893 unsigned flags)
1894 {
1895 return index_bulk_checkin(oid, fd, size, type, path, flags);
1896 }
1897
1898 int index_fd(struct object_id *oid, int fd, struct stat *st,
1899 enum object_type type, const char *path, unsigned flags)
1900 {
1901 int ret;
1902
1903 /*
1904 * Call xsize_t() only when needed to avoid potentially unnecessary
1905 * die() for large files.
1906 */
1907 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
1908 ret = index_stream_convert_blob(oid, fd, path, flags);
1909 else if (!S_ISREG(st->st_mode))
1910 ret = index_pipe(oid, fd, type, path, flags);
1911 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
1912 (path && would_convert_to_git(&the_index, path)))
1913 ret = index_core(oid, fd, xsize_t(st->st_size), type, path,
1914 flags);
1915 else
1916 ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
1917 flags);
1918 close(fd);
1919 return ret;
1920 }
1921
1922 int index_path(struct object_id *oid, const char *path, struct stat *st, unsigned flags)
1923 {
1924 int fd;
1925 struct strbuf sb = STRBUF_INIT;
1926 int rc = 0;
1927
1928 switch (st->st_mode & S_IFMT) {
1929 case S_IFREG:
1930 fd = open(path, O_RDONLY);
1931 if (fd < 0)
1932 return error_errno("open(\"%s\")", path);
1933 if (index_fd(oid, fd, st, OBJ_BLOB, path, flags) < 0)
1934 return error("%s: failed to insert into database",
1935 path);
1936 break;
1937 case S_IFLNK:
1938 if (strbuf_readlink(&sb, path, st->st_size))
1939 return error_errno("readlink(\"%s\")", path);
1940 if (!(flags & HASH_WRITE_OBJECT))
1941 hash_object_file(sb.buf, sb.len, blob_type, oid);
1942 else if (write_object_file(sb.buf, sb.len, blob_type, oid))
1943 rc = error("%s: failed to insert into database", path);
1944 strbuf_release(&sb);
1945 break;
1946 case S_IFDIR:
1947 return resolve_gitlink_ref(path, "HEAD", oid);
1948 default:
1949 return error("%s: unsupported file type", path);
1950 }
1951 return rc;
1952 }
1953
1954 int read_pack_header(int fd, struct pack_header *header)
1955 {
1956 if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
1957 /* "eof before pack header was fully read" */
1958 return PH_ERROR_EOF;
1959
1960 if (header->hdr_signature != htonl(PACK_SIGNATURE))
1961 /* "protocol error (pack signature mismatch detected)" */
1962 return PH_ERROR_PACK_SIGNATURE;
1963 if (!pack_version_ok(header->hdr_version))
1964 /* "protocol error (pack version unsupported)" */
1965 return PH_ERROR_PROTOCOL;
1966 return 0;
1967 }
1968
1969 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
1970 {
1971 enum object_type type = sha1_object_info(sha1, NULL);
1972 if (type < 0)
1973 die("%s is not a valid object", sha1_to_hex(sha1));
1974 if (type != expect)
1975 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
1976 type_name(expect));
1977 }
1978
1979 int for_each_file_in_obj_subdir(unsigned int subdir_nr,
1980 struct strbuf *path,
1981 each_loose_object_fn obj_cb,
1982 each_loose_cruft_fn cruft_cb,
1983 each_loose_subdir_fn subdir_cb,
1984 void *data)
1985 {
1986 size_t origlen, baselen;
1987 DIR *dir;
1988 struct dirent *de;
1989 int r = 0;
1990 struct object_id oid;
1991
1992 if (subdir_nr > 0xff)
1993 BUG("invalid loose object subdirectory: %x", subdir_nr);
1994
1995 origlen = path->len;
1996 strbuf_complete(path, '/');
1997 strbuf_addf(path, "%02x", subdir_nr);
1998
1999 dir = opendir(path->buf);
2000 if (!dir) {
2001 if (errno != ENOENT)
2002 r = error_errno("unable to open %s", path->buf);
2003 strbuf_setlen(path, origlen);
2004 return r;
2005 }
2006
2007 oid.hash[0] = subdir_nr;
2008 strbuf_addch(path, '/');
2009 baselen = path->len;
2010
2011 while ((de = readdir(dir))) {
2012 size_t namelen;
2013 if (is_dot_or_dotdot(de->d_name))
2014 continue;
2015
2016 namelen = strlen(de->d_name);
2017 strbuf_setlen(path, baselen);
2018 strbuf_add(path, de->d_name, namelen);
2019 if (namelen == GIT_SHA1_HEXSZ - 2 &&
2020 !hex_to_bytes(oid.hash + 1, de->d_name,
2021 GIT_SHA1_RAWSZ - 1)) {
2022 if (obj_cb) {
2023 r = obj_cb(&oid, path->buf, data);
2024 if (r)
2025 break;
2026 }
2027 continue;
2028 }
2029
2030 if (cruft_cb) {
2031 r = cruft_cb(de->d_name, path->buf, data);
2032 if (r)
2033 break;
2034 }
2035 }
2036 closedir(dir);
2037
2038 strbuf_setlen(path, baselen - 1);
2039 if (!r && subdir_cb)
2040 r = subdir_cb(subdir_nr, path->buf, data);
2041
2042 strbuf_setlen(path, origlen);
2043
2044 return r;
2045 }
2046
2047 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
2048 each_loose_object_fn obj_cb,
2049 each_loose_cruft_fn cruft_cb,
2050 each_loose_subdir_fn subdir_cb,
2051 void *data)
2052 {
2053 int r = 0;
2054 int i;
2055
2056 for (i = 0; i < 256; i++) {
2057 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
2058 subdir_cb, data);
2059 if (r)
2060 break;
2061 }
2062
2063 return r;
2064 }
2065
2066 int for_each_loose_file_in_objdir(const char *path,
2067 each_loose_object_fn obj_cb,
2068 each_loose_cruft_fn cruft_cb,
2069 each_loose_subdir_fn subdir_cb,
2070 void *data)
2071 {
2072 struct strbuf buf = STRBUF_INIT;
2073 int r;
2074
2075 strbuf_addstr(&buf, path);
2076 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
2077 subdir_cb, data);
2078 strbuf_release(&buf);
2079
2080 return r;
2081 }
2082
2083 struct loose_alt_odb_data {
2084 each_loose_object_fn *cb;
2085 void *data;
2086 };
2087
2088 static int loose_from_alt_odb(struct alternate_object_database *alt,
2089 void *vdata)
2090 {
2091 struct loose_alt_odb_data *data = vdata;
2092 struct strbuf buf = STRBUF_INIT;
2093 int r;
2094
2095 strbuf_addstr(&buf, alt->path);
2096 r = for_each_loose_file_in_objdir_buf(&buf,
2097 data->cb, NULL, NULL,
2098 data->data);
2099 strbuf_release(&buf);
2100 return r;
2101 }
2102
2103 int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
2104 {
2105 struct loose_alt_odb_data alt;
2106 int r;
2107
2108 r = for_each_loose_file_in_objdir(get_object_directory(),
2109 cb, NULL, NULL, data);
2110 if (r)
2111 return r;
2112
2113 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
2114 return 0;
2115
2116 alt.cb = cb;
2117 alt.data = data;
2118 return foreach_alt_odb(loose_from_alt_odb, &alt);
2119 }
2120
2121 static int check_stream_sha1(git_zstream *stream,
2122 const char *hdr,
2123 unsigned long size,
2124 const char *path,
2125 const unsigned char *expected_sha1)
2126 {
2127 git_hash_ctx c;
2128 unsigned char real_sha1[GIT_MAX_RAWSZ];
2129 unsigned char buf[4096];
2130 unsigned long total_read;
2131 int status = Z_OK;
2132
2133 the_hash_algo->init_fn(&c);
2134 the_hash_algo->update_fn(&c, hdr, stream->total_out);
2135
2136 /*
2137 * We already read some bytes into hdr, but the ones up to the NUL
2138 * do not count against the object's content size.
2139 */
2140 total_read = stream->total_out - strlen(hdr) - 1;
2141
2142 /*
2143 * This size comparison must be "<=" to read the final zlib packets;
2144 * see the comment in unpack_sha1_rest for details.
2145 */
2146 while (total_read <= size &&
2147 (status == Z_OK || status == Z_BUF_ERROR)) {
2148 stream->next_out = buf;
2149 stream->avail_out = sizeof(buf);
2150 if (size - total_read < stream->avail_out)
2151 stream->avail_out = size - total_read;
2152 status = git_inflate(stream, Z_FINISH);
2153 the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
2154 total_read += stream->next_out - buf;
2155 }
2156 git_inflate_end(stream);
2157
2158 if (status != Z_STREAM_END) {
2159 error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
2160 return -1;
2161 }
2162 if (stream->avail_in) {
2163 error("garbage at end of loose object '%s'",
2164 sha1_to_hex(expected_sha1));
2165 return -1;
2166 }
2167
2168 the_hash_algo->final_fn(real_sha1, &c);
2169 if (hashcmp(expected_sha1, real_sha1)) {
2170 error("sha1 mismatch for %s (expected %s)", path,
2171 sha1_to_hex(expected_sha1));
2172 return -1;
2173 }
2174
2175 return 0;
2176 }
2177
2178 int read_loose_object(const char *path,
2179 const struct object_id *expected_oid,
2180 enum object_type *type,
2181 unsigned long *size,
2182 void **contents)
2183 {
2184 int ret = -1;
2185 void *map = NULL;
2186 unsigned long mapsize;
2187 git_zstream stream;
2188 char hdr[32];
2189
2190 *contents = NULL;
2191
2192 map = map_sha1_file_1(path, NULL, &mapsize);
2193 if (!map) {
2194 error_errno("unable to mmap %s", path);
2195 goto out;
2196 }
2197
2198 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
2199 error("unable to unpack header of %s", path);
2200 goto out;
2201 }
2202
2203 *type = parse_sha1_header(hdr, size);
2204 if (*type < 0) {
2205 error("unable to parse header of %s", path);
2206 git_inflate_end(&stream);
2207 goto out;
2208 }
2209
2210 if (*type == OBJ_BLOB) {
2211 if (check_stream_sha1(&stream, hdr, *size, path, expected_oid->hash) < 0)
2212 goto out;
2213 } else {
2214 *contents = unpack_sha1_rest(&stream, hdr, *size, expected_oid->hash);
2215 if (!*contents) {
2216 error("unable to unpack contents of %s", path);
2217 git_inflate_end(&stream);
2218 goto out;
2219 }
2220 if (check_sha1_signature(expected_oid->hash, *contents,
2221 *size, type_name(*type))) {
2222 error("sha1 mismatch for %s (expected %s)", path,
2223 oid_to_hex(expected_oid));
2224 free(*contents);
2225 goto out;
2226 }
2227 }
2228
2229 ret = 0; /* everything checks out */
2230
2231 out:
2232 if (map)
2233 munmap(map, mapsize);
2234 return ret;
2235 }