e1292c11fd55eb58fc8db805e9c71f6362bc8348
[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_object_signature(const struct object_id *oid, 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 oidcmp(oid, &real_oid) ? -1 : 0;
800 }
801
802 st = open_istream(oid, &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 oidcmp(oid, &real_oid) ? -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 oid_object_info_extended(const struct object_id *oid, 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(oid->hash) :
1232 oid->hash;
1233 int already_retried = 0;
1234 struct object_id realoid;
1235
1236 hashcpy(realoid.hash, real);
1237
1238 if (is_null_sha1(real))
1239 return -1;
1240
1241 if (!oi)
1242 oi = &blank_oi;
1243
1244 if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
1245 struct cached_object *co = find_cached_object(real);
1246 if (co) {
1247 if (oi->typep)
1248 *(oi->typep) = co->type;
1249 if (oi->sizep)
1250 *(oi->sizep) = co->size;
1251 if (oi->disk_sizep)
1252 *(oi->disk_sizep) = 0;
1253 if (oi->delta_base_sha1)
1254 hashclr(oi->delta_base_sha1);
1255 if (oi->type_name)
1256 strbuf_addstr(oi->type_name, type_name(co->type));
1257 if (oi->contentp)
1258 *oi->contentp = xmemdupz(co->buf, co->size);
1259 oi->whence = OI_CACHED;
1260 return 0;
1261 }
1262 }
1263
1264 while (1) {
1265 if (find_pack_entry(real, &e))
1266 break;
1267
1268 /* Most likely it's a loose object. */
1269 if (!sha1_loose_object_info(real, oi, flags))
1270 return 0;
1271
1272 /* Not a loose object; someone else may have just packed it. */
1273 reprepare_packed_git();
1274 if (find_pack_entry(real, &e))
1275 break;
1276
1277 /* Check if it is a missing object */
1278 if (fetch_if_missing && repository_format_partial_clone &&
1279 !already_retried) {
1280 /*
1281 * TODO Investigate haveing fetch_object() return
1282 * TODO error/success and stopping the music here.
1283 */
1284 fetch_object(repository_format_partial_clone, real);
1285 already_retried = 1;
1286 continue;
1287 }
1288
1289 return -1;
1290 }
1291
1292 if (oi == &blank_oi)
1293 /*
1294 * We know that the caller doesn't actually need the
1295 * information below, so return early.
1296 */
1297 return 0;
1298 rtype = packed_object_info(e.p, e.offset, oi);
1299 if (rtype < 0) {
1300 mark_bad_packed_object(e.p, real);
1301 return oid_object_info_extended(&realoid, oi, 0);
1302 } else if (oi->whence == OI_PACKED) {
1303 oi->u.packed.offset = e.offset;
1304 oi->u.packed.pack = e.p;
1305 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
1306 rtype == OBJ_OFS_DELTA);
1307 }
1308
1309 return 0;
1310 }
1311
1312 /* returns enum object_type or negative */
1313 int oid_object_info(const struct object_id *oid, unsigned long *sizep)
1314 {
1315 enum object_type type;
1316 struct object_info oi = OBJECT_INFO_INIT;
1317
1318 oi.typep = &type;
1319 oi.sizep = sizep;
1320 if (oid_object_info_extended(oid, &oi,
1321 OBJECT_INFO_LOOKUP_REPLACE) < 0)
1322 return -1;
1323 return type;
1324 }
1325
1326 static void *read_object(const unsigned char *sha1, enum object_type *type,
1327 unsigned long *size)
1328 {
1329 struct object_id oid;
1330 struct object_info oi = OBJECT_INFO_INIT;
1331 void *content;
1332 oi.typep = type;
1333 oi.sizep = size;
1334 oi.contentp = &content;
1335
1336 hashcpy(oid.hash, sha1);
1337
1338 if (oid_object_info_extended(&oid, &oi, 0) < 0)
1339 return NULL;
1340 return content;
1341 }
1342
1343 int pretend_object_file(void *buf, unsigned long len, enum object_type type,
1344 struct object_id *oid)
1345 {
1346 struct cached_object *co;
1347
1348 hash_object_file(buf, len, type_name(type), oid);
1349 if (has_sha1_file(oid->hash) || find_cached_object(oid->hash))
1350 return 0;
1351 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
1352 co = &cached_objects[cached_object_nr++];
1353 co->size = len;
1354 co->type = type;
1355 co->buf = xmalloc(len);
1356 memcpy(co->buf, buf, len);
1357 hashcpy(co->sha1, oid->hash);
1358 return 0;
1359 }
1360
1361 /*
1362 * This function dies on corrupt objects; the callers who want to
1363 * deal with them should arrange to call read_object() and give error
1364 * messages themselves.
1365 */
1366 void *read_sha1_file_extended(const unsigned char *sha1,
1367 enum object_type *type,
1368 unsigned long *size,
1369 int lookup_replace)
1370 {
1371 void *data;
1372 const struct packed_git *p;
1373 const char *path;
1374 struct stat st;
1375 const unsigned char *repl = lookup_replace ? lookup_replace_object(sha1)
1376 : sha1;
1377
1378 errno = 0;
1379 data = read_object(repl, type, size);
1380 if (data)
1381 return data;
1382
1383 if (errno && errno != ENOENT)
1384 die_errno("failed to read object %s", sha1_to_hex(sha1));
1385
1386 /* die if we replaced an object with one that does not exist */
1387 if (repl != sha1)
1388 die("replacement %s not found for %s",
1389 sha1_to_hex(repl), sha1_to_hex(sha1));
1390
1391 if (!stat_sha1_file(repl, &st, &path))
1392 die("loose object %s (stored in %s) is corrupt",
1393 sha1_to_hex(repl), path);
1394
1395 if ((p = has_packed_and_bad(repl)) != NULL)
1396 die("packed object %s (stored in %s) is corrupt",
1397 sha1_to_hex(repl), p->pack_name);
1398
1399 return NULL;
1400 }
1401
1402 void *read_object_with_reference(const unsigned char *sha1,
1403 const char *required_type_name,
1404 unsigned long *size,
1405 unsigned char *actual_sha1_return)
1406 {
1407 enum object_type type, required_type;
1408 void *buffer;
1409 unsigned long isize;
1410 unsigned char actual_sha1[20];
1411
1412 required_type = type_from_string(required_type_name);
1413 hashcpy(actual_sha1, sha1);
1414 while (1) {
1415 int ref_length = -1;
1416 const char *ref_type = NULL;
1417
1418 buffer = read_sha1_file(actual_sha1, &type, &isize);
1419 if (!buffer)
1420 return NULL;
1421 if (type == required_type) {
1422 *size = isize;
1423 if (actual_sha1_return)
1424 hashcpy(actual_sha1_return, actual_sha1);
1425 return buffer;
1426 }
1427 /* Handle references */
1428 else if (type == OBJ_COMMIT)
1429 ref_type = "tree ";
1430 else if (type == OBJ_TAG)
1431 ref_type = "object ";
1432 else {
1433 free(buffer);
1434 return NULL;
1435 }
1436 ref_length = strlen(ref_type);
1437
1438 if (ref_length + 40 > isize ||
1439 memcmp(buffer, ref_type, ref_length) ||
1440 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1441 free(buffer);
1442 return NULL;
1443 }
1444 free(buffer);
1445 /* Now we have the ID of the referred-to object in
1446 * actual_sha1. Check again. */
1447 }
1448 }
1449
1450 static void write_object_file_prepare(const void *buf, unsigned long len,
1451 const char *type, struct object_id *oid,
1452 char *hdr, int *hdrlen)
1453 {
1454 git_hash_ctx c;
1455
1456 /* Generate the header */
1457 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
1458
1459 /* Sha1.. */
1460 the_hash_algo->init_fn(&c);
1461 the_hash_algo->update_fn(&c, hdr, *hdrlen);
1462 the_hash_algo->update_fn(&c, buf, len);
1463 the_hash_algo->final_fn(oid->hash, &c);
1464 }
1465
1466 /*
1467 * Move the just written object into its final resting place.
1468 */
1469 int finalize_object_file(const char *tmpfile, const char *filename)
1470 {
1471 int ret = 0;
1472
1473 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
1474 goto try_rename;
1475 else if (link(tmpfile, filename))
1476 ret = errno;
1477
1478 /*
1479 * Coda hack - coda doesn't like cross-directory links,
1480 * so we fall back to a rename, which will mean that it
1481 * won't be able to check collisions, but that's not a
1482 * big deal.
1483 *
1484 * The same holds for FAT formatted media.
1485 *
1486 * When this succeeds, we just return. We have nothing
1487 * left to unlink.
1488 */
1489 if (ret && ret != EEXIST) {
1490 try_rename:
1491 if (!rename(tmpfile, filename))
1492 goto out;
1493 ret = errno;
1494 }
1495 unlink_or_warn(tmpfile);
1496 if (ret) {
1497 if (ret != EEXIST) {
1498 return error_errno("unable to write sha1 filename %s", filename);
1499 }
1500 /* FIXME!!! Collision check here ? */
1501 }
1502
1503 out:
1504 if (adjust_shared_perm(filename))
1505 return error("unable to set permission to '%s'", filename);
1506 return 0;
1507 }
1508
1509 static int write_buffer(int fd, const void *buf, size_t len)
1510 {
1511 if (write_in_full(fd, buf, len) < 0)
1512 return error_errno("file write error");
1513 return 0;
1514 }
1515
1516 int hash_object_file(const void *buf, unsigned long len, const char *type,
1517 struct object_id *oid)
1518 {
1519 char hdr[32];
1520 int hdrlen = sizeof(hdr);
1521 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1522 return 0;
1523 }
1524
1525 /* Finalize a file on disk, and close it. */
1526 static void close_sha1_file(int fd)
1527 {
1528 if (fsync_object_files)
1529 fsync_or_die(fd, "sha1 file");
1530 if (close(fd) != 0)
1531 die_errno("error when closing sha1 file");
1532 }
1533
1534 /* Size of directory component, including the ending '/' */
1535 static inline int directory_size(const char *filename)
1536 {
1537 const char *s = strrchr(filename, '/');
1538 if (!s)
1539 return 0;
1540 return s - filename + 1;
1541 }
1542
1543 /*
1544 * This creates a temporary file in the same directory as the final
1545 * 'filename'
1546 *
1547 * We want to avoid cross-directory filename renames, because those
1548 * can have problems on various filesystems (FAT, NFS, Coda).
1549 */
1550 static int create_tmpfile(struct strbuf *tmp, const char *filename)
1551 {
1552 int fd, dirlen = directory_size(filename);
1553
1554 strbuf_reset(tmp);
1555 strbuf_add(tmp, filename, dirlen);
1556 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
1557 fd = git_mkstemp_mode(tmp->buf, 0444);
1558 if (fd < 0 && dirlen && errno == ENOENT) {
1559 /*
1560 * Make sure the directory exists; note that the contents
1561 * of the buffer are undefined after mkstemp returns an
1562 * error, so we have to rewrite the whole buffer from
1563 * scratch.
1564 */
1565 strbuf_reset(tmp);
1566 strbuf_add(tmp, filename, dirlen - 1);
1567 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
1568 return -1;
1569 if (adjust_shared_perm(tmp->buf))
1570 return -1;
1571
1572 /* Try again */
1573 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
1574 fd = git_mkstemp_mode(tmp->buf, 0444);
1575 }
1576 return fd;
1577 }
1578
1579 static int write_loose_object(const struct object_id *oid, char *hdr,
1580 int hdrlen, const void *buf, unsigned long len,
1581 time_t mtime)
1582 {
1583 int fd, ret;
1584 unsigned char compressed[4096];
1585 git_zstream stream;
1586 git_hash_ctx c;
1587 struct object_id parano_oid;
1588 static struct strbuf tmp_file = STRBUF_INIT;
1589 static struct strbuf filename = STRBUF_INIT;
1590
1591 strbuf_reset(&filename);
1592 sha1_file_name(&filename, oid->hash);
1593
1594 fd = create_tmpfile(&tmp_file, filename.buf);
1595 if (fd < 0) {
1596 if (errno == EACCES)
1597 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
1598 else
1599 return error_errno("unable to create temporary file");
1600 }
1601
1602 /* Set it up */
1603 git_deflate_init(&stream, zlib_compression_level);
1604 stream.next_out = compressed;
1605 stream.avail_out = sizeof(compressed);
1606 the_hash_algo->init_fn(&c);
1607
1608 /* First header.. */
1609 stream.next_in = (unsigned char *)hdr;
1610 stream.avail_in = hdrlen;
1611 while (git_deflate(&stream, 0) == Z_OK)
1612 ; /* nothing */
1613 the_hash_algo->update_fn(&c, hdr, hdrlen);
1614
1615 /* Then the data itself.. */
1616 stream.next_in = (void *)buf;
1617 stream.avail_in = len;
1618 do {
1619 unsigned char *in0 = stream.next_in;
1620 ret = git_deflate(&stream, Z_FINISH);
1621 the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
1622 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
1623 die("unable to write sha1 file");
1624 stream.next_out = compressed;
1625 stream.avail_out = sizeof(compressed);
1626 } while (ret == Z_OK);
1627
1628 if (ret != Z_STREAM_END)
1629 die("unable to deflate new object %s (%d)", oid_to_hex(oid),
1630 ret);
1631 ret = git_deflate_end_gently(&stream);
1632 if (ret != Z_OK)
1633 die("deflateEnd on object %s failed (%d)", oid_to_hex(oid),
1634 ret);
1635 the_hash_algo->final_fn(parano_oid.hash, &c);
1636 if (oidcmp(oid, &parano_oid) != 0)
1637 die("confused by unstable object source data for %s",
1638 oid_to_hex(oid));
1639
1640 close_sha1_file(fd);
1641
1642 if (mtime) {
1643 struct utimbuf utb;
1644 utb.actime = mtime;
1645 utb.modtime = mtime;
1646 if (utime(tmp_file.buf, &utb) < 0)
1647 warning_errno("failed utime() on %s", tmp_file.buf);
1648 }
1649
1650 return finalize_object_file(tmp_file.buf, filename.buf);
1651 }
1652
1653 static int freshen_loose_object(const unsigned char *sha1)
1654 {
1655 return check_and_freshen(sha1, 1);
1656 }
1657
1658 static int freshen_packed_object(const unsigned char *sha1)
1659 {
1660 struct pack_entry e;
1661 if (!find_pack_entry(sha1, &e))
1662 return 0;
1663 if (e.p->freshened)
1664 return 1;
1665 if (!freshen_file(e.p->pack_name))
1666 return 0;
1667 e.p->freshened = 1;
1668 return 1;
1669 }
1670
1671 int write_object_file(const void *buf, unsigned long len, const char *type,
1672 struct object_id *oid)
1673 {
1674 char hdr[32];
1675 int hdrlen = sizeof(hdr);
1676
1677 /* Normally if we have it in the pack then we do not bother writing
1678 * it out into .git/objects/??/?{38} file.
1679 */
1680 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1681 if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
1682 return 0;
1683 return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
1684 }
1685
1686 int hash_object_file_literally(const void *buf, unsigned long len,
1687 const char *type, struct object_id *oid,
1688 unsigned flags)
1689 {
1690 char *header;
1691 int hdrlen, status = 0;
1692
1693 /* type string, SP, %lu of the length plus NUL must fit this */
1694 hdrlen = strlen(type) + 32;
1695 header = xmalloc(hdrlen);
1696 write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
1697
1698 if (!(flags & HASH_WRITE_OBJECT))
1699 goto cleanup;
1700 if (freshen_packed_object(oid->hash) || freshen_loose_object(oid->hash))
1701 goto cleanup;
1702 status = write_loose_object(oid, header, hdrlen, buf, len, 0);
1703
1704 cleanup:
1705 free(header);
1706 return status;
1707 }
1708
1709 int force_object_loose(const struct object_id *oid, time_t mtime)
1710 {
1711 void *buf;
1712 unsigned long len;
1713 enum object_type type;
1714 char hdr[32];
1715 int hdrlen;
1716 int ret;
1717
1718 if (has_loose_object(oid->hash))
1719 return 0;
1720 buf = read_object(oid->hash, &type, &len);
1721 if (!buf)
1722 return error("cannot read sha1_file for %s", oid_to_hex(oid));
1723 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
1724 ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
1725 free(buf);
1726
1727 return ret;
1728 }
1729
1730 int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
1731 {
1732 struct object_id oid;
1733 if (!startup_info->have_repository)
1734 return 0;
1735 hashcpy(oid.hash, sha1);
1736 return oid_object_info_extended(&oid, NULL,
1737 flags | OBJECT_INFO_SKIP_CACHED) >= 0;
1738 }
1739
1740 int has_object_file(const struct object_id *oid)
1741 {
1742 return has_sha1_file(oid->hash);
1743 }
1744
1745 int has_object_file_with_flags(const struct object_id *oid, int flags)
1746 {
1747 return has_sha1_file_with_flags(oid->hash, flags);
1748 }
1749
1750 static void check_tree(const void *buf, size_t size)
1751 {
1752 struct tree_desc desc;
1753 struct name_entry entry;
1754
1755 init_tree_desc(&desc, buf, size);
1756 while (tree_entry(&desc, &entry))
1757 /* do nothing
1758 * tree_entry() will die() on malformed entries */
1759 ;
1760 }
1761
1762 static void check_commit(const void *buf, size_t size)
1763 {
1764 struct commit c;
1765 memset(&c, 0, sizeof(c));
1766 if (parse_commit_buffer(&c, buf, size))
1767 die("corrupt commit");
1768 }
1769
1770 static void check_tag(const void *buf, size_t size)
1771 {
1772 struct tag t;
1773 memset(&t, 0, sizeof(t));
1774 if (parse_tag_buffer(&t, buf, size))
1775 die("corrupt tag");
1776 }
1777
1778 static int index_mem(struct object_id *oid, void *buf, size_t size,
1779 enum object_type type,
1780 const char *path, unsigned flags)
1781 {
1782 int ret, re_allocated = 0;
1783 int write_object = flags & HASH_WRITE_OBJECT;
1784
1785 if (!type)
1786 type = OBJ_BLOB;
1787
1788 /*
1789 * Convert blobs to git internal format
1790 */
1791 if ((type == OBJ_BLOB) && path) {
1792 struct strbuf nbuf = STRBUF_INIT;
1793 if (convert_to_git(&the_index, path, buf, size, &nbuf,
1794 get_conv_flags(flags))) {
1795 buf = strbuf_detach(&nbuf, &size);
1796 re_allocated = 1;
1797 }
1798 }
1799 if (flags & HASH_FORMAT_CHECK) {
1800 if (type == OBJ_TREE)
1801 check_tree(buf, size);
1802 if (type == OBJ_COMMIT)
1803 check_commit(buf, size);
1804 if (type == OBJ_TAG)
1805 check_tag(buf, size);
1806 }
1807
1808 if (write_object)
1809 ret = write_object_file(buf, size, type_name(type), oid);
1810 else
1811 ret = hash_object_file(buf, size, type_name(type), oid);
1812 if (re_allocated)
1813 free(buf);
1814 return ret;
1815 }
1816
1817 static int index_stream_convert_blob(struct object_id *oid, int fd,
1818 const char *path, unsigned flags)
1819 {
1820 int ret;
1821 const int write_object = flags & HASH_WRITE_OBJECT;
1822 struct strbuf sbuf = STRBUF_INIT;
1823
1824 assert(path);
1825 assert(would_convert_to_git_filter_fd(path));
1826
1827 convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
1828 get_conv_flags(flags));
1829
1830 if (write_object)
1831 ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1832 oid);
1833 else
1834 ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1835 oid);
1836 strbuf_release(&sbuf);
1837 return ret;
1838 }
1839
1840 static int index_pipe(struct object_id *oid, int fd, enum object_type type,
1841 const char *path, unsigned flags)
1842 {
1843 struct strbuf sbuf = STRBUF_INIT;
1844 int ret;
1845
1846 if (strbuf_read(&sbuf, fd, 4096) >= 0)
1847 ret = index_mem(oid, sbuf.buf, sbuf.len, type, path, flags);
1848 else
1849 ret = -1;
1850 strbuf_release(&sbuf);
1851 return ret;
1852 }
1853
1854 #define SMALL_FILE_SIZE (32*1024)
1855
1856 static int index_core(struct object_id *oid, int fd, size_t size,
1857 enum object_type type, const char *path,
1858 unsigned flags)
1859 {
1860 int ret;
1861
1862 if (!size) {
1863 ret = index_mem(oid, "", size, type, path, flags);
1864 } else if (size <= SMALL_FILE_SIZE) {
1865 char *buf = xmalloc(size);
1866 ssize_t read_result = read_in_full(fd, buf, size);
1867 if (read_result < 0)
1868 ret = error_errno("read error while indexing %s",
1869 path ? path : "<unknown>");
1870 else if (read_result != size)
1871 ret = error("short read while indexing %s",
1872 path ? path : "<unknown>");
1873 else
1874 ret = index_mem(oid, buf, size, type, path, flags);
1875 free(buf);
1876 } else {
1877 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1878 ret = index_mem(oid, buf, size, type, path, flags);
1879 munmap(buf, size);
1880 }
1881 return ret;
1882 }
1883
1884 /*
1885 * This creates one packfile per large blob unless bulk-checkin
1886 * machinery is "plugged".
1887 *
1888 * This also bypasses the usual "convert-to-git" dance, and that is on
1889 * purpose. We could write a streaming version of the converting
1890 * functions and insert that before feeding the data to fast-import
1891 * (or equivalent in-core API described above). However, that is
1892 * somewhat complicated, as we do not know the size of the filter
1893 * result, which we need to know beforehand when writing a git object.
1894 * Since the primary motivation for trying to stream from the working
1895 * tree file and to avoid mmaping it in core is to deal with large
1896 * binary blobs, they generally do not want to get any conversion, and
1897 * callers should avoid this code path when filters are requested.
1898 */
1899 static int index_stream(struct object_id *oid, int fd, size_t size,
1900 enum object_type type, const char *path,
1901 unsigned flags)
1902 {
1903 return index_bulk_checkin(oid, fd, size, type, path, flags);
1904 }
1905
1906 int index_fd(struct object_id *oid, int fd, struct stat *st,
1907 enum object_type type, const char *path, unsigned flags)
1908 {
1909 int ret;
1910
1911 /*
1912 * Call xsize_t() only when needed to avoid potentially unnecessary
1913 * die() for large files.
1914 */
1915 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
1916 ret = index_stream_convert_blob(oid, fd, path, flags);
1917 else if (!S_ISREG(st->st_mode))
1918 ret = index_pipe(oid, fd, type, path, flags);
1919 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
1920 (path && would_convert_to_git(&the_index, path)))
1921 ret = index_core(oid, fd, xsize_t(st->st_size), type, path,
1922 flags);
1923 else
1924 ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
1925 flags);
1926 close(fd);
1927 return ret;
1928 }
1929
1930 int index_path(struct object_id *oid, const char *path, struct stat *st, unsigned flags)
1931 {
1932 int fd;
1933 struct strbuf sb = STRBUF_INIT;
1934 int rc = 0;
1935
1936 switch (st->st_mode & S_IFMT) {
1937 case S_IFREG:
1938 fd = open(path, O_RDONLY);
1939 if (fd < 0)
1940 return error_errno("open(\"%s\")", path);
1941 if (index_fd(oid, fd, st, OBJ_BLOB, path, flags) < 0)
1942 return error("%s: failed to insert into database",
1943 path);
1944 break;
1945 case S_IFLNK:
1946 if (strbuf_readlink(&sb, path, st->st_size))
1947 return error_errno("readlink(\"%s\")", path);
1948 if (!(flags & HASH_WRITE_OBJECT))
1949 hash_object_file(sb.buf, sb.len, blob_type, oid);
1950 else if (write_object_file(sb.buf, sb.len, blob_type, oid))
1951 rc = error("%s: failed to insert into database", path);
1952 strbuf_release(&sb);
1953 break;
1954 case S_IFDIR:
1955 return resolve_gitlink_ref(path, "HEAD", oid);
1956 default:
1957 return error("%s: unsupported file type", path);
1958 }
1959 return rc;
1960 }
1961
1962 int read_pack_header(int fd, struct pack_header *header)
1963 {
1964 if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
1965 /* "eof before pack header was fully read" */
1966 return PH_ERROR_EOF;
1967
1968 if (header->hdr_signature != htonl(PACK_SIGNATURE))
1969 /* "protocol error (pack signature mismatch detected)" */
1970 return PH_ERROR_PACK_SIGNATURE;
1971 if (!pack_version_ok(header->hdr_version))
1972 /* "protocol error (pack version unsupported)" */
1973 return PH_ERROR_PROTOCOL;
1974 return 0;
1975 }
1976
1977 void assert_oid_type(const struct object_id *oid, enum object_type expect)
1978 {
1979 enum object_type type = oid_object_info(oid, NULL);
1980 if (type < 0)
1981 die("%s is not a valid object", oid_to_hex(oid));
1982 if (type != expect)
1983 die("%s is not a valid '%s' object", oid_to_hex(oid),
1984 type_name(expect));
1985 }
1986
1987 int for_each_file_in_obj_subdir(unsigned int subdir_nr,
1988 struct strbuf *path,
1989 each_loose_object_fn obj_cb,
1990 each_loose_cruft_fn cruft_cb,
1991 each_loose_subdir_fn subdir_cb,
1992 void *data)
1993 {
1994 size_t origlen, baselen;
1995 DIR *dir;
1996 struct dirent *de;
1997 int r = 0;
1998 struct object_id oid;
1999
2000 if (subdir_nr > 0xff)
2001 BUG("invalid loose object subdirectory: %x", subdir_nr);
2002
2003 origlen = path->len;
2004 strbuf_complete(path, '/');
2005 strbuf_addf(path, "%02x", subdir_nr);
2006
2007 dir = opendir(path->buf);
2008 if (!dir) {
2009 if (errno != ENOENT)
2010 r = error_errno("unable to open %s", path->buf);
2011 strbuf_setlen(path, origlen);
2012 return r;
2013 }
2014
2015 oid.hash[0] = subdir_nr;
2016 strbuf_addch(path, '/');
2017 baselen = path->len;
2018
2019 while ((de = readdir(dir))) {
2020 size_t namelen;
2021 if (is_dot_or_dotdot(de->d_name))
2022 continue;
2023
2024 namelen = strlen(de->d_name);
2025 strbuf_setlen(path, baselen);
2026 strbuf_add(path, de->d_name, namelen);
2027 if (namelen == GIT_SHA1_HEXSZ - 2 &&
2028 !hex_to_bytes(oid.hash + 1, de->d_name,
2029 GIT_SHA1_RAWSZ - 1)) {
2030 if (obj_cb) {
2031 r = obj_cb(&oid, path->buf, data);
2032 if (r)
2033 break;
2034 }
2035 continue;
2036 }
2037
2038 if (cruft_cb) {
2039 r = cruft_cb(de->d_name, path->buf, data);
2040 if (r)
2041 break;
2042 }
2043 }
2044 closedir(dir);
2045
2046 strbuf_setlen(path, baselen - 1);
2047 if (!r && subdir_cb)
2048 r = subdir_cb(subdir_nr, path->buf, data);
2049
2050 strbuf_setlen(path, origlen);
2051
2052 return r;
2053 }
2054
2055 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
2056 each_loose_object_fn obj_cb,
2057 each_loose_cruft_fn cruft_cb,
2058 each_loose_subdir_fn subdir_cb,
2059 void *data)
2060 {
2061 int r = 0;
2062 int i;
2063
2064 for (i = 0; i < 256; i++) {
2065 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
2066 subdir_cb, data);
2067 if (r)
2068 break;
2069 }
2070
2071 return r;
2072 }
2073
2074 int for_each_loose_file_in_objdir(const char *path,
2075 each_loose_object_fn obj_cb,
2076 each_loose_cruft_fn cruft_cb,
2077 each_loose_subdir_fn subdir_cb,
2078 void *data)
2079 {
2080 struct strbuf buf = STRBUF_INIT;
2081 int r;
2082
2083 strbuf_addstr(&buf, path);
2084 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
2085 subdir_cb, data);
2086 strbuf_release(&buf);
2087
2088 return r;
2089 }
2090
2091 struct loose_alt_odb_data {
2092 each_loose_object_fn *cb;
2093 void *data;
2094 };
2095
2096 static int loose_from_alt_odb(struct alternate_object_database *alt,
2097 void *vdata)
2098 {
2099 struct loose_alt_odb_data *data = vdata;
2100 struct strbuf buf = STRBUF_INIT;
2101 int r;
2102
2103 strbuf_addstr(&buf, alt->path);
2104 r = for_each_loose_file_in_objdir_buf(&buf,
2105 data->cb, NULL, NULL,
2106 data->data);
2107 strbuf_release(&buf);
2108 return r;
2109 }
2110
2111 int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
2112 {
2113 struct loose_alt_odb_data alt;
2114 int r;
2115
2116 r = for_each_loose_file_in_objdir(get_object_directory(),
2117 cb, NULL, NULL, data);
2118 if (r)
2119 return r;
2120
2121 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
2122 return 0;
2123
2124 alt.cb = cb;
2125 alt.data = data;
2126 return foreach_alt_odb(loose_from_alt_odb, &alt);
2127 }
2128
2129 static int check_stream_sha1(git_zstream *stream,
2130 const char *hdr,
2131 unsigned long size,
2132 const char *path,
2133 const unsigned char *expected_sha1)
2134 {
2135 git_hash_ctx c;
2136 unsigned char real_sha1[GIT_MAX_RAWSZ];
2137 unsigned char buf[4096];
2138 unsigned long total_read;
2139 int status = Z_OK;
2140
2141 the_hash_algo->init_fn(&c);
2142 the_hash_algo->update_fn(&c, hdr, stream->total_out);
2143
2144 /*
2145 * We already read some bytes into hdr, but the ones up to the NUL
2146 * do not count against the object's content size.
2147 */
2148 total_read = stream->total_out - strlen(hdr) - 1;
2149
2150 /*
2151 * This size comparison must be "<=" to read the final zlib packets;
2152 * see the comment in unpack_sha1_rest for details.
2153 */
2154 while (total_read <= size &&
2155 (status == Z_OK || status == Z_BUF_ERROR)) {
2156 stream->next_out = buf;
2157 stream->avail_out = sizeof(buf);
2158 if (size - total_read < stream->avail_out)
2159 stream->avail_out = size - total_read;
2160 status = git_inflate(stream, Z_FINISH);
2161 the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
2162 total_read += stream->next_out - buf;
2163 }
2164 git_inflate_end(stream);
2165
2166 if (status != Z_STREAM_END) {
2167 error("corrupt loose object '%s'", sha1_to_hex(expected_sha1));
2168 return -1;
2169 }
2170 if (stream->avail_in) {
2171 error("garbage at end of loose object '%s'",
2172 sha1_to_hex(expected_sha1));
2173 return -1;
2174 }
2175
2176 the_hash_algo->final_fn(real_sha1, &c);
2177 if (hashcmp(expected_sha1, real_sha1)) {
2178 error("sha1 mismatch for %s (expected %s)", path,
2179 sha1_to_hex(expected_sha1));
2180 return -1;
2181 }
2182
2183 return 0;
2184 }
2185
2186 int read_loose_object(const char *path,
2187 const struct object_id *expected_oid,
2188 enum object_type *type,
2189 unsigned long *size,
2190 void **contents)
2191 {
2192 int ret = -1;
2193 void *map = NULL;
2194 unsigned long mapsize;
2195 git_zstream stream;
2196 char hdr[32];
2197
2198 *contents = NULL;
2199
2200 map = map_sha1_file_1(path, NULL, &mapsize);
2201 if (!map) {
2202 error_errno("unable to mmap %s", path);
2203 goto out;
2204 }
2205
2206 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
2207 error("unable to unpack header of %s", path);
2208 goto out;
2209 }
2210
2211 *type = parse_sha1_header(hdr, size);
2212 if (*type < 0) {
2213 error("unable to parse header of %s", path);
2214 git_inflate_end(&stream);
2215 goto out;
2216 }
2217
2218 if (*type == OBJ_BLOB) {
2219 if (check_stream_sha1(&stream, hdr, *size, path, expected_oid->hash) < 0)
2220 goto out;
2221 } else {
2222 *contents = unpack_sha1_rest(&stream, hdr, *size, expected_oid->hash);
2223 if (!*contents) {
2224 error("unable to unpack contents of %s", path);
2225 git_inflate_end(&stream);
2226 goto out;
2227 }
2228 if (check_object_signature(expected_oid, *contents,
2229 *size, type_name(*type))) {
2230 error("sha1 mismatch for %s (expected %s)", path,
2231 oid_to_hex(expected_oid));
2232 free(*contents);
2233 goto out;
2234 }
2235 }
2236
2237 ret = 0; /* everything checks out */
2238
2239 out:
2240 if (map)
2241 munmap(map, mapsize);
2242 return ret;
2243 }