478eac326b65c4528ec8be464bf02407306dfc31
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 "repository.h"
26#include "replace-object.h"
27#include "streaming.h"
28#include "dir.h"
29#include "list.h"
30#include "mergesort.h"
31#include "quote.h"
32#include "packfile.h"
33#include "fetch-object.h"
34#include "object-store.h"
35
36/* The maximum size for an object header. */
37#define MAX_HEADER_LEN 32
38
39
40#define EMPTY_TREE_SHA1_BIN_LITERAL \
41 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
42 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
43
44#define EMPTY_BLOB_SHA1_BIN_LITERAL \
45 "\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
46 "\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
47
48const unsigned char null_sha1[GIT_MAX_RAWSZ];
49const struct object_id null_oid;
50static const struct object_id empty_tree_oid = {
51 EMPTY_TREE_SHA1_BIN_LITERAL
52};
53static const struct object_id empty_blob_oid = {
54 EMPTY_BLOB_SHA1_BIN_LITERAL
55};
56
57static void git_hash_sha1_init(git_hash_ctx *ctx)
58{
59 git_SHA1_Init(&ctx->sha1);
60}
61
62static void git_hash_sha1_update(git_hash_ctx *ctx, const void *data, size_t len)
63{
64 git_SHA1_Update(&ctx->sha1, data, len);
65}
66
67static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx)
68{
69 git_SHA1_Final(hash, &ctx->sha1);
70}
71
72static void git_hash_unknown_init(git_hash_ctx *ctx)
73{
74 BUG("trying to init unknown hash");
75}
76
77static void git_hash_unknown_update(git_hash_ctx *ctx, const void *data, size_t len)
78{
79 BUG("trying to update unknown hash");
80}
81
82static void git_hash_unknown_final(unsigned char *hash, git_hash_ctx *ctx)
83{
84 BUG("trying to finalize unknown hash");
85}
86
87const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = {
88 {
89 NULL,
90 0x00000000,
91 0,
92 0,
93 git_hash_unknown_init,
94 git_hash_unknown_update,
95 git_hash_unknown_final,
96 NULL,
97 NULL,
98 },
99 {
100 "sha-1",
101 /* "sha1", big-endian */
102 0x73686131,
103 GIT_SHA1_RAWSZ,
104 GIT_SHA1_HEXSZ,
105 git_hash_sha1_init,
106 git_hash_sha1_update,
107 git_hash_sha1_final,
108 &empty_tree_oid,
109 &empty_blob_oid,
110 },
111};
112
113const char *empty_tree_oid_hex(void)
114{
115 static char buf[GIT_MAX_HEXSZ + 1];
116 return oid_to_hex_r(buf, the_hash_algo->empty_tree);
117}
118
119const char *empty_blob_oid_hex(void)
120{
121 static char buf[GIT_MAX_HEXSZ + 1];
122 return oid_to_hex_r(buf, the_hash_algo->empty_blob);
123}
124
125/*
126 * This is meant to hold a *small* number of objects that you would
127 * want read_sha1_file() to be able to return, but yet you do not want
128 * to write them into the object store (e.g. a browse-only
129 * application).
130 */
131static struct cached_object {
132 struct object_id oid;
133 enum object_type type;
134 void *buf;
135 unsigned long size;
136} *cached_objects;
137static int cached_object_nr, cached_object_alloc;
138
139static struct cached_object empty_tree = {
140 { EMPTY_TREE_SHA1_BIN_LITERAL },
141 OBJ_TREE,
142 "",
143 0
144};
145
146static struct cached_object *find_cached_object(const struct object_id *oid)
147{
148 int i;
149 struct cached_object *co = cached_objects;
150
151 for (i = 0; i < cached_object_nr; i++, co++) {
152 if (oideq(&co->oid, oid))
153 return co;
154 }
155 if (oideq(oid, the_hash_algo->empty_tree))
156 return &empty_tree;
157 return NULL;
158}
159
160
161static int get_conv_flags(unsigned flags)
162{
163 if (flags & HASH_RENORMALIZE)
164 return CONV_EOL_RENORMALIZE;
165 else if (flags & HASH_WRITE_OBJECT)
166 return global_conv_flags_eol | CONV_WRITE_OBJECT;
167 else
168 return 0;
169}
170
171
172int mkdir_in_gitdir(const char *path)
173{
174 if (mkdir(path, 0777)) {
175 int saved_errno = errno;
176 struct stat st;
177 struct strbuf sb = STRBUF_INIT;
178
179 if (errno != EEXIST)
180 return -1;
181 /*
182 * Are we looking at a path in a symlinked worktree
183 * whose original repository does not yet have it?
184 * e.g. .git/rr-cache pointing at its original
185 * repository in which the user hasn't performed any
186 * conflict resolution yet?
187 */
188 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
189 strbuf_readlink(&sb, path, st.st_size) ||
190 !is_absolute_path(sb.buf) ||
191 mkdir(sb.buf, 0777)) {
192 strbuf_release(&sb);
193 errno = saved_errno;
194 return -1;
195 }
196 strbuf_release(&sb);
197 }
198 return adjust_shared_perm(path);
199}
200
201enum scld_error safe_create_leading_directories(char *path)
202{
203 char *next_component = path + offset_1st_component(path);
204 enum scld_error ret = SCLD_OK;
205
206 while (ret == SCLD_OK && next_component) {
207 struct stat st;
208 char *slash = next_component, slash_character;
209
210 while (*slash && !is_dir_sep(*slash))
211 slash++;
212
213 if (!*slash)
214 break;
215
216 next_component = slash + 1;
217 while (is_dir_sep(*next_component))
218 next_component++;
219 if (!*next_component)
220 break;
221
222 slash_character = *slash;
223 *slash = '\0';
224 if (!stat(path, &st)) {
225 /* path exists */
226 if (!S_ISDIR(st.st_mode)) {
227 errno = ENOTDIR;
228 ret = SCLD_EXISTS;
229 }
230 } else if (mkdir(path, 0777)) {
231 if (errno == EEXIST &&
232 !stat(path, &st) && S_ISDIR(st.st_mode))
233 ; /* somebody created it since we checked */
234 else if (errno == ENOENT)
235 /*
236 * Either mkdir() failed because
237 * somebody just pruned the containing
238 * directory, or stat() failed because
239 * the file that was in our way was
240 * just removed. Either way, inform
241 * the caller that it might be worth
242 * trying again:
243 */
244 ret = SCLD_VANISHED;
245 else
246 ret = SCLD_FAILED;
247 } else if (adjust_shared_perm(path)) {
248 ret = SCLD_PERMS;
249 }
250 *slash = slash_character;
251 }
252 return ret;
253}
254
255enum scld_error safe_create_leading_directories_const(const char *path)
256{
257 int save_errno;
258 /* path points to cache entries, so xstrdup before messing with it */
259 char *buf = xstrdup(path);
260 enum scld_error result = safe_create_leading_directories(buf);
261
262 save_errno = errno;
263 free(buf);
264 errno = save_errno;
265 return result;
266}
267
268int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
269{
270 /*
271 * The number of times we will try to remove empty directories
272 * in the way of path. This is only 1 because if another
273 * process is racily creating directories that conflict with
274 * us, we don't want to fight against them.
275 */
276 int remove_directories_remaining = 1;
277
278 /*
279 * The number of times that we will try to create the
280 * directories containing path. We are willing to attempt this
281 * more than once, because another process could be trying to
282 * clean up empty directories at the same time as we are
283 * trying to create them.
284 */
285 int create_directories_remaining = 3;
286
287 /* A scratch copy of path, filled lazily if we need it: */
288 struct strbuf path_copy = STRBUF_INIT;
289
290 int ret, save_errno;
291
292 /* Sanity check: */
293 assert(*path);
294
295retry_fn:
296 ret = fn(path, cb);
297 save_errno = errno;
298 if (!ret)
299 goto out;
300
301 if (errno == EISDIR && remove_directories_remaining-- > 0) {
302 /*
303 * A directory is in the way. Maybe it is empty; try
304 * to remove it:
305 */
306 if (!path_copy.len)
307 strbuf_addstr(&path_copy, path);
308
309 if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
310 goto retry_fn;
311 } else if (errno == ENOENT && create_directories_remaining-- > 0) {
312 /*
313 * Maybe the containing directory didn't exist, or
314 * maybe it was just deleted by a process that is
315 * racing with us to clean up empty directories. Try
316 * to create it:
317 */
318 enum scld_error scld_result;
319
320 if (!path_copy.len)
321 strbuf_addstr(&path_copy, path);
322
323 do {
324 scld_result = safe_create_leading_directories(path_copy.buf);
325 if (scld_result == SCLD_OK)
326 goto retry_fn;
327 } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
328 }
329
330out:
331 strbuf_release(&path_copy);
332 errno = save_errno;
333 return ret;
334}
335
336static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
337{
338 int i;
339 for (i = 0; i < the_hash_algo->rawsz; i++) {
340 static char hex[] = "0123456789abcdef";
341 unsigned int val = sha1[i];
342 strbuf_addch(buf, hex[val >> 4]);
343 strbuf_addch(buf, hex[val & 0xf]);
344 if (!i)
345 strbuf_addch(buf, '/');
346 }
347}
348
349void loose_object_path(struct repository *r, struct strbuf *buf,
350 const unsigned char *sha1)
351{
352 strbuf_reset(buf);
353 strbuf_addstr(buf, r->objects->objectdir);
354 strbuf_addch(buf, '/');
355 fill_sha1_path(buf, sha1);
356}
357
358struct strbuf *alt_scratch_buf(struct object_directory *odb)
359{
360 strbuf_setlen(&odb->scratch, odb->base_len);
361 return &odb->scratch;
362}
363
364static const char *alt_sha1_path(struct object_directory *odb,
365 const unsigned char *sha1)
366{
367 struct strbuf *buf = alt_scratch_buf(odb);
368 fill_sha1_path(buf, sha1);
369 return buf->buf;
370}
371
372/*
373 * Return non-zero iff the path is usable as an alternate object database.
374 */
375static int alt_odb_usable(struct raw_object_store *o,
376 struct strbuf *path,
377 const char *normalized_objdir)
378{
379 struct object_directory *odb;
380
381 /* Detect cases where alternate disappeared */
382 if (!is_directory(path->buf)) {
383 error(_("object directory %s does not exist; "
384 "check .git/objects/info/alternates"),
385 path->buf);
386 return 0;
387 }
388
389 /*
390 * Prevent the common mistake of listing the same
391 * thing twice, or object directory itself.
392 */
393 for (odb = o->alt_odb_list; odb; odb = odb->next) {
394 if (!fspathcmp(path->buf, odb->path))
395 return 0;
396 }
397 if (!fspathcmp(path->buf, normalized_objdir))
398 return 0;
399
400 return 1;
401}
402
403/*
404 * Prepare alternate object database registry.
405 *
406 * The variable alt_odb_list points at the list of struct
407 * object_directory. The elements on this list come from
408 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
409 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
410 * whose contents is similar to that environment variable but can be
411 * LF separated. Its base points at a statically allocated buffer that
412 * contains "/the/directory/corresponding/to/.git/objects/...", while
413 * its name points just after the slash at the end of ".git/objects/"
414 * in the example above, and has enough space to hold 40-byte hex
415 * SHA1, an extra slash for the first level indirection, and the
416 * terminating NUL.
417 */
418static void read_info_alternates(struct repository *r,
419 const char *relative_base,
420 int depth);
421static int link_alt_odb_entry(struct repository *r, const char *entry,
422 const char *relative_base, int depth, const char *normalized_objdir)
423{
424 struct object_directory *ent;
425 struct strbuf pathbuf = STRBUF_INIT;
426
427 if (!is_absolute_path(entry) && relative_base) {
428 strbuf_realpath(&pathbuf, relative_base, 1);
429 strbuf_addch(&pathbuf, '/');
430 }
431 strbuf_addstr(&pathbuf, entry);
432
433 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
434 error(_("unable to normalize alternate object path: %s"),
435 pathbuf.buf);
436 strbuf_release(&pathbuf);
437 return -1;
438 }
439
440 /*
441 * The trailing slash after the directory name is given by
442 * this function at the end. Remove duplicates.
443 */
444 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
445 strbuf_setlen(&pathbuf, pathbuf.len - 1);
446
447 if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir)) {
448 strbuf_release(&pathbuf);
449 return -1;
450 }
451
452 ent = alloc_alt_odb(pathbuf.buf);
453
454 /* add the alternate entry */
455 *r->objects->alt_odb_tail = ent;
456 r->objects->alt_odb_tail = &(ent->next);
457 ent->next = NULL;
458
459 /* recursively add alternates */
460 read_info_alternates(r, pathbuf.buf, depth + 1);
461
462 strbuf_release(&pathbuf);
463 return 0;
464}
465
466static const char *parse_alt_odb_entry(const char *string,
467 int sep,
468 struct strbuf *out)
469{
470 const char *end;
471
472 strbuf_reset(out);
473
474 if (*string == '#') {
475 /* comment; consume up to next separator */
476 end = strchrnul(string, sep);
477 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
478 /*
479 * quoted path; unquote_c_style has copied the
480 * data for us and set "end". Broken quoting (e.g.,
481 * an entry that doesn't end with a quote) falls
482 * back to the unquoted case below.
483 */
484 } else {
485 /* normal, unquoted path */
486 end = strchrnul(string, sep);
487 strbuf_add(out, string, end - string);
488 }
489
490 if (*end)
491 end++;
492 return end;
493}
494
495static void link_alt_odb_entries(struct repository *r, const char *alt,
496 int sep, const char *relative_base, int depth)
497{
498 struct strbuf objdirbuf = STRBUF_INIT;
499 struct strbuf entry = STRBUF_INIT;
500
501 if (!alt || !*alt)
502 return;
503
504 if (depth > 5) {
505 error(_("%s: ignoring alternate object stores, nesting too deep"),
506 relative_base);
507 return;
508 }
509
510 strbuf_add_absolute_path(&objdirbuf, r->objects->objectdir);
511 if (strbuf_normalize_path(&objdirbuf) < 0)
512 die(_("unable to normalize object directory: %s"),
513 objdirbuf.buf);
514
515 while (*alt) {
516 alt = parse_alt_odb_entry(alt, sep, &entry);
517 if (!entry.len)
518 continue;
519 link_alt_odb_entry(r, entry.buf,
520 relative_base, depth, objdirbuf.buf);
521 }
522 strbuf_release(&entry);
523 strbuf_release(&objdirbuf);
524}
525
526static void read_info_alternates(struct repository *r,
527 const char *relative_base,
528 int depth)
529{
530 char *path;
531 struct strbuf buf = STRBUF_INIT;
532
533 path = xstrfmt("%s/info/alternates", relative_base);
534 if (strbuf_read_file(&buf, path, 1024) < 0) {
535 warn_on_fopen_errors(path);
536 free(path);
537 return;
538 }
539
540 link_alt_odb_entries(r, buf.buf, '\n', relative_base, depth);
541 strbuf_release(&buf);
542 free(path);
543}
544
545struct object_directory *alloc_alt_odb(const char *dir)
546{
547 struct object_directory *ent;
548
549 FLEX_ALLOC_STR(ent, path, dir);
550 strbuf_init(&ent->scratch, 0);
551 strbuf_addf(&ent->scratch, "%s/", dir);
552 ent->base_len = ent->scratch.len;
553
554 return ent;
555}
556
557void add_to_alternates_file(const char *reference)
558{
559 struct lock_file lock = LOCK_INIT;
560 char *alts = git_pathdup("objects/info/alternates");
561 FILE *in, *out;
562 int found = 0;
563
564 hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
565 out = fdopen_lock_file(&lock, "w");
566 if (!out)
567 die_errno(_("unable to fdopen alternates lockfile"));
568
569 in = fopen(alts, "r");
570 if (in) {
571 struct strbuf line = STRBUF_INIT;
572
573 while (strbuf_getline(&line, in) != EOF) {
574 if (!strcmp(reference, line.buf)) {
575 found = 1;
576 break;
577 }
578 fprintf_or_die(out, "%s\n", line.buf);
579 }
580
581 strbuf_release(&line);
582 fclose(in);
583 }
584 else if (errno != ENOENT)
585 die_errno(_("unable to read alternates file"));
586
587 if (found) {
588 rollback_lock_file(&lock);
589 } else {
590 fprintf_or_die(out, "%s\n", reference);
591 if (commit_lock_file(&lock))
592 die_errno(_("unable to move new alternates file into place"));
593 if (the_repository->objects->alt_odb_tail)
594 link_alt_odb_entries(the_repository, reference,
595 '\n', NULL, 0);
596 }
597 free(alts);
598}
599
600void add_to_alternates_memory(const char *reference)
601{
602 /*
603 * Make sure alternates are initialized, or else our entry may be
604 * overwritten when they are.
605 */
606 prepare_alt_odb(the_repository);
607
608 link_alt_odb_entries(the_repository, reference,
609 '\n', NULL, 0);
610}
611
612/*
613 * Compute the exact path an alternate is at and returns it. In case of
614 * error NULL is returned and the human readable error is added to `err`
615 * `path` may be relative and should point to $GIT_DIR.
616 * `err` must not be null.
617 */
618char *compute_alternate_path(const char *path, struct strbuf *err)
619{
620 char *ref_git = NULL;
621 const char *repo, *ref_git_s;
622 int seen_error = 0;
623
624 ref_git_s = real_path_if_valid(path);
625 if (!ref_git_s) {
626 seen_error = 1;
627 strbuf_addf(err, _("path '%s' does not exist"), path);
628 goto out;
629 } else
630 /*
631 * Beware: read_gitfile(), real_path() and mkpath()
632 * return static buffer
633 */
634 ref_git = xstrdup(ref_git_s);
635
636 repo = read_gitfile(ref_git);
637 if (!repo)
638 repo = read_gitfile(mkpath("%s/.git", ref_git));
639 if (repo) {
640 free(ref_git);
641 ref_git = xstrdup(repo);
642 }
643
644 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
645 char *ref_git_git = mkpathdup("%s/.git", ref_git);
646 free(ref_git);
647 ref_git = ref_git_git;
648 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
649 struct strbuf sb = STRBUF_INIT;
650 seen_error = 1;
651 if (get_common_dir(&sb, ref_git)) {
652 strbuf_addf(err,
653 _("reference repository '%s' as a linked "
654 "checkout is not supported yet."),
655 path);
656 goto out;
657 }
658
659 strbuf_addf(err, _("reference repository '%s' is not a "
660 "local repository."), path);
661 goto out;
662 }
663
664 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
665 strbuf_addf(err, _("reference repository '%s' is shallow"),
666 path);
667 seen_error = 1;
668 goto out;
669 }
670
671 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
672 strbuf_addf(err,
673 _("reference repository '%s' is grafted"),
674 path);
675 seen_error = 1;
676 goto out;
677 }
678
679out:
680 if (seen_error) {
681 FREE_AND_NULL(ref_git);
682 }
683
684 return ref_git;
685}
686
687int foreach_alt_odb(alt_odb_fn fn, void *cb)
688{
689 struct object_directory *ent;
690 int r = 0;
691
692 prepare_alt_odb(the_repository);
693 for (ent = the_repository->objects->alt_odb_list; ent; ent = ent->next) {
694 r = fn(ent, cb);
695 if (r)
696 break;
697 }
698 return r;
699}
700
701void prepare_alt_odb(struct repository *r)
702{
703 if (r->objects->alt_odb_tail)
704 return;
705
706 r->objects->alt_odb_tail = &r->objects->alt_odb_list;
707 link_alt_odb_entries(r, r->objects->alternate_db, PATH_SEP, NULL, 0);
708
709 read_info_alternates(r, r->objects->objectdir, 0);
710}
711
712/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
713static int freshen_file(const char *fn)
714{
715 struct utimbuf t;
716 t.actime = t.modtime = time(NULL);
717 return !utime(fn, &t);
718}
719
720/*
721 * All of the check_and_freshen functions return 1 if the file exists and was
722 * freshened (if freshening was requested), 0 otherwise. If they return
723 * 0, you should not assume that it is safe to skip a write of the object (it
724 * either does not exist on disk, or has a stale mtime and may be subject to
725 * pruning).
726 */
727int check_and_freshen_file(const char *fn, int freshen)
728{
729 if (access(fn, F_OK))
730 return 0;
731 if (freshen && !freshen_file(fn))
732 return 0;
733 return 1;
734}
735
736static int check_and_freshen_local(const struct object_id *oid, int freshen)
737{
738 static struct strbuf buf = STRBUF_INIT;
739
740 loose_object_path(the_repository, &buf, oid->hash);
741
742 return check_and_freshen_file(buf.buf, freshen);
743}
744
745static int check_and_freshen_nonlocal(const struct object_id *oid, int freshen)
746{
747 struct object_directory *odb;
748 prepare_alt_odb(the_repository);
749 for (odb = the_repository->objects->alt_odb_list; odb; odb = odb->next) {
750 const char *path = alt_sha1_path(odb, oid->hash);
751 if (check_and_freshen_file(path, freshen))
752 return 1;
753 }
754 return 0;
755}
756
757static int check_and_freshen(const struct object_id *oid, int freshen)
758{
759 return check_and_freshen_local(oid, freshen) ||
760 check_and_freshen_nonlocal(oid, freshen);
761}
762
763int has_loose_object_nonlocal(const struct object_id *oid)
764{
765 return check_and_freshen_nonlocal(oid, 0);
766}
767
768static int has_loose_object(const struct object_id *oid)
769{
770 return check_and_freshen(oid, 0);
771}
772
773static void mmap_limit_check(size_t length)
774{
775 static size_t limit = 0;
776 if (!limit) {
777 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
778 if (!limit)
779 limit = SIZE_MAX;
780 }
781 if (length > limit)
782 die(_("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX),
783 (uintmax_t)length, (uintmax_t)limit);
784}
785
786void *xmmap_gently(void *start, size_t length,
787 int prot, int flags, int fd, off_t offset)
788{
789 void *ret;
790
791 mmap_limit_check(length);
792 ret = mmap(start, length, prot, flags, fd, offset);
793 if (ret == MAP_FAILED) {
794 if (!length)
795 return NULL;
796 release_pack_memory(length);
797 ret = mmap(start, length, prot, flags, fd, offset);
798 }
799 return ret;
800}
801
802void *xmmap(void *start, size_t length,
803 int prot, int flags, int fd, off_t offset)
804{
805 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
806 if (ret == MAP_FAILED)
807 die_errno(_("mmap failed"));
808 return ret;
809}
810
811/*
812 * With an in-core object data in "map", rehash it to make sure the
813 * object name actually matches "sha1" to detect object corruption.
814 * With "map" == NULL, try reading the object named with "sha1" using
815 * the streaming interface and rehash it to do the same.
816 */
817int check_object_signature(const struct object_id *oid, void *map,
818 unsigned long size, const char *type)
819{
820 struct object_id real_oid;
821 enum object_type obj_type;
822 struct git_istream *st;
823 git_hash_ctx c;
824 char hdr[MAX_HEADER_LEN];
825 int hdrlen;
826
827 if (map) {
828 hash_object_file(map, size, type, &real_oid);
829 return !oideq(oid, &real_oid) ? -1 : 0;
830 }
831
832 st = open_istream(oid, &obj_type, &size, NULL);
833 if (!st)
834 return -1;
835
836 /* Generate the header */
837 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(obj_type), size) + 1;
838
839 /* Sha1.. */
840 the_hash_algo->init_fn(&c);
841 the_hash_algo->update_fn(&c, hdr, hdrlen);
842 for (;;) {
843 char buf[1024 * 16];
844 ssize_t readlen = read_istream(st, buf, sizeof(buf));
845
846 if (readlen < 0) {
847 close_istream(st);
848 return -1;
849 }
850 if (!readlen)
851 break;
852 the_hash_algo->update_fn(&c, buf, readlen);
853 }
854 the_hash_algo->final_fn(real_oid.hash, &c);
855 close_istream(st);
856 return !oideq(oid, &real_oid) ? -1 : 0;
857}
858
859int git_open_cloexec(const char *name, int flags)
860{
861 int fd;
862 static int o_cloexec = O_CLOEXEC;
863
864 fd = open(name, flags | o_cloexec);
865 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
866 /* Try again w/o O_CLOEXEC: the kernel might not support it */
867 o_cloexec &= ~O_CLOEXEC;
868 fd = open(name, flags | o_cloexec);
869 }
870
871#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
872 {
873 static int fd_cloexec = FD_CLOEXEC;
874
875 if (!o_cloexec && 0 <= fd && fd_cloexec) {
876 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
877 int flags = fcntl(fd, F_GETFD);
878 if (fcntl(fd, F_SETFD, flags | fd_cloexec))
879 fd_cloexec = 0;
880 }
881 }
882#endif
883 return fd;
884}
885
886/*
887 * Find "sha1" as a loose object in the local repository or in an alternate.
888 * Returns 0 on success, negative on failure.
889 *
890 * The "path" out-parameter will give the path of the object we found (if any).
891 * Note that it may point to static storage and is only valid until another
892 * call to loose_object_path(), etc.
893 */
894static int stat_sha1_file(struct repository *r, const unsigned char *sha1,
895 struct stat *st, const char **path)
896{
897 struct object_directory *odb;
898 static struct strbuf buf = STRBUF_INIT;
899
900 loose_object_path(r, &buf, sha1);
901 *path = buf.buf;
902
903 if (!lstat(*path, st))
904 return 0;
905
906 prepare_alt_odb(r);
907 errno = ENOENT;
908 for (odb = r->objects->alt_odb_list; odb; odb = odb->next) {
909 *path = alt_sha1_path(odb, sha1);
910 if (!lstat(*path, st))
911 return 0;
912 }
913
914 return -1;
915}
916
917/*
918 * Like stat_sha1_file(), but actually open the object and return the
919 * descriptor. See the caveats on the "path" parameter above.
920 */
921static int open_sha1_file(struct repository *r,
922 const unsigned char *sha1, const char **path)
923{
924 int fd;
925 struct object_directory *odb;
926 int most_interesting_errno;
927 static struct strbuf buf = STRBUF_INIT;
928
929 loose_object_path(r, &buf, sha1);
930 *path = buf.buf;
931
932 fd = git_open(*path);
933 if (fd >= 0)
934 return fd;
935 most_interesting_errno = errno;
936
937 prepare_alt_odb(r);
938 for (odb = r->objects->alt_odb_list; odb; odb = odb->next) {
939 *path = alt_sha1_path(odb, sha1);
940 fd = git_open(*path);
941 if (fd >= 0)
942 return fd;
943 if (most_interesting_errno == ENOENT)
944 most_interesting_errno = errno;
945 }
946 errno = most_interesting_errno;
947 return -1;
948}
949
950/*
951 * Map the loose object at "path" if it is not NULL, or the path found by
952 * searching for a loose object named "sha1".
953 */
954static void *map_sha1_file_1(struct repository *r, const char *path,
955 const unsigned char *sha1, unsigned long *size)
956{
957 void *map;
958 int fd;
959
960 if (path)
961 fd = git_open(path);
962 else
963 fd = open_sha1_file(r, sha1, &path);
964 map = NULL;
965 if (fd >= 0) {
966 struct stat st;
967
968 if (!fstat(fd, &st)) {
969 *size = xsize_t(st.st_size);
970 if (!*size) {
971 /* mmap() is forbidden on empty files */
972 error(_("object file %s is empty"), path);
973 return NULL;
974 }
975 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
976 }
977 close(fd);
978 }
979 return map;
980}
981
982void *map_sha1_file(struct repository *r,
983 const unsigned char *sha1, unsigned long *size)
984{
985 return map_sha1_file_1(r, NULL, sha1, size);
986}
987
988static int unpack_sha1_short_header(git_zstream *stream,
989 unsigned char *map, unsigned long mapsize,
990 void *buffer, unsigned long bufsiz)
991{
992 /* Get the data stream */
993 memset(stream, 0, sizeof(*stream));
994 stream->next_in = map;
995 stream->avail_in = mapsize;
996 stream->next_out = buffer;
997 stream->avail_out = bufsiz;
998
999 git_inflate_init(stream);
1000 return git_inflate(stream, 0);
1001}
1002
1003int unpack_sha1_header(git_zstream *stream,
1004 unsigned char *map, unsigned long mapsize,
1005 void *buffer, unsigned long bufsiz)
1006{
1007 int status = unpack_sha1_short_header(stream, map, mapsize,
1008 buffer, bufsiz);
1009
1010 if (status < Z_OK)
1011 return status;
1012
1013 /* Make sure we have the terminating NUL */
1014 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1015 return -1;
1016 return 0;
1017}
1018
1019static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1020 unsigned long mapsize, void *buffer,
1021 unsigned long bufsiz, struct strbuf *header)
1022{
1023 int status;
1024
1025 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
1026 if (status < Z_OK)
1027 return -1;
1028
1029 /*
1030 * Check if entire header is unpacked in the first iteration.
1031 */
1032 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1033 return 0;
1034
1035 /*
1036 * buffer[0..bufsiz] was not large enough. Copy the partial
1037 * result out to header, and then append the result of further
1038 * reading the stream.
1039 */
1040 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1041 stream->next_out = buffer;
1042 stream->avail_out = bufsiz;
1043
1044 do {
1045 status = git_inflate(stream, 0);
1046 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1047 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1048 return 0;
1049 stream->next_out = buffer;
1050 stream->avail_out = bufsiz;
1051 } while (status != Z_STREAM_END);
1052 return -1;
1053}
1054
1055static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1056{
1057 int bytes = strlen(buffer) + 1;
1058 unsigned char *buf = xmallocz(size);
1059 unsigned long n;
1060 int status = Z_OK;
1061
1062 n = stream->total_out - bytes;
1063 if (n > size)
1064 n = size;
1065 memcpy(buf, (char *) buffer + bytes, n);
1066 bytes = n;
1067 if (bytes <= size) {
1068 /*
1069 * The above condition must be (bytes <= size), not
1070 * (bytes < size). In other words, even though we
1071 * expect no more output and set avail_out to zero,
1072 * the input zlib stream may have bytes that express
1073 * "this concludes the stream", and we *do* want to
1074 * eat that input.
1075 *
1076 * Otherwise we would not be able to test that we
1077 * consumed all the input to reach the expected size;
1078 * we also want to check that zlib tells us that all
1079 * went well with status == Z_STREAM_END at the end.
1080 */
1081 stream->next_out = buf + bytes;
1082 stream->avail_out = size - bytes;
1083 while (status == Z_OK)
1084 status = git_inflate(stream, Z_FINISH);
1085 }
1086 if (status == Z_STREAM_END && !stream->avail_in) {
1087 git_inflate_end(stream);
1088 return buf;
1089 }
1090
1091 if (status < 0)
1092 error(_("corrupt loose object '%s'"), sha1_to_hex(sha1));
1093 else if (stream->avail_in)
1094 error(_("garbage at end of loose object '%s'"),
1095 sha1_to_hex(sha1));
1096 free(buf);
1097 return NULL;
1098}
1099
1100/*
1101 * We used to just use "sscanf()", but that's actually way
1102 * too permissive for what we want to check. So do an anal
1103 * object header parse by hand.
1104 */
1105static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1106 unsigned int flags)
1107{
1108 const char *type_buf = hdr;
1109 unsigned long size;
1110 int type, type_len = 0;
1111
1112 /*
1113 * The type can be of any size but is followed by
1114 * a space.
1115 */
1116 for (;;) {
1117 char c = *hdr++;
1118 if (!c)
1119 return -1;
1120 if (c == ' ')
1121 break;
1122 type_len++;
1123 }
1124
1125 type = type_from_string_gently(type_buf, type_len, 1);
1126 if (oi->type_name)
1127 strbuf_add(oi->type_name, type_buf, type_len);
1128 /*
1129 * Set type to 0 if its an unknown object and
1130 * we're obtaining the type using '--allow-unknown-type'
1131 * option.
1132 */
1133 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
1134 type = 0;
1135 else if (type < 0)
1136 die(_("invalid object type"));
1137 if (oi->typep)
1138 *oi->typep = type;
1139
1140 /*
1141 * The length must follow immediately, and be in canonical
1142 * decimal format (ie "010" is not valid).
1143 */
1144 size = *hdr++ - '0';
1145 if (size > 9)
1146 return -1;
1147 if (size) {
1148 for (;;) {
1149 unsigned long c = *hdr - '0';
1150 if (c > 9)
1151 break;
1152 hdr++;
1153 size = size * 10 + c;
1154 }
1155 }
1156
1157 if (oi->sizep)
1158 *oi->sizep = size;
1159
1160 /*
1161 * The length must be followed by a zero byte
1162 */
1163 return *hdr ? -1 : type;
1164}
1165
1166int parse_sha1_header(const char *hdr, unsigned long *sizep)
1167{
1168 struct object_info oi = OBJECT_INFO_INIT;
1169
1170 oi.sizep = sizep;
1171 return parse_sha1_header_extended(hdr, &oi, 0);
1172}
1173
1174static int sha1_loose_object_info(struct repository *r,
1175 const unsigned char *sha1,
1176 struct object_info *oi, int flags)
1177{
1178 int status = 0;
1179 unsigned long mapsize;
1180 void *map;
1181 git_zstream stream;
1182 char hdr[MAX_HEADER_LEN];
1183 struct strbuf hdrbuf = STRBUF_INIT;
1184 unsigned long size_scratch;
1185
1186 if (oi->delta_base_sha1)
1187 hashclr(oi->delta_base_sha1);
1188
1189 /*
1190 * If we don't care about type or size, then we don't
1191 * need to look inside the object at all. Note that we
1192 * do not optimize out the stat call, even if the
1193 * caller doesn't care about the disk-size, since our
1194 * return value implicitly indicates whether the
1195 * object even exists.
1196 */
1197 if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
1198 const char *path;
1199 struct stat st;
1200 if (stat_sha1_file(r, sha1, &st, &path) < 0)
1201 return -1;
1202 if (oi->disk_sizep)
1203 *oi->disk_sizep = st.st_size;
1204 return 0;
1205 }
1206
1207 map = map_sha1_file(r, sha1, &mapsize);
1208 if (!map)
1209 return -1;
1210
1211 if (!oi->sizep)
1212 oi->sizep = &size_scratch;
1213
1214 if (oi->disk_sizep)
1215 *oi->disk_sizep = mapsize;
1216 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
1217 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
1218 status = error(_("unable to unpack %s header with --allow-unknown-type"),
1219 sha1_to_hex(sha1));
1220 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1221 status = error(_("unable to unpack %s header"),
1222 sha1_to_hex(sha1));
1223 if (status < 0)
1224 ; /* Do nothing */
1225 else if (hdrbuf.len) {
1226 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
1227 status = error(_("unable to parse %s header with --allow-unknown-type"),
1228 sha1_to_hex(sha1));
1229 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
1230 status = error(_("unable to parse %s header"), sha1_to_hex(sha1));
1231
1232 if (status >= 0 && oi->contentp) {
1233 *oi->contentp = unpack_sha1_rest(&stream, hdr,
1234 *oi->sizep, sha1);
1235 if (!*oi->contentp) {
1236 git_inflate_end(&stream);
1237 status = -1;
1238 }
1239 } else
1240 git_inflate_end(&stream);
1241
1242 munmap(map, mapsize);
1243 if (status && oi->typep)
1244 *oi->typep = status;
1245 if (oi->sizep == &size_scratch)
1246 oi->sizep = NULL;
1247 strbuf_release(&hdrbuf);
1248 oi->whence = OI_LOOSE;
1249 return (status < 0) ? status : 0;
1250}
1251
1252int fetch_if_missing = 1;
1253
1254int oid_object_info_extended(struct repository *r, const struct object_id *oid,
1255 struct object_info *oi, unsigned flags)
1256{
1257 static struct object_info blank_oi = OBJECT_INFO_INIT;
1258 struct pack_entry e;
1259 int rtype;
1260 const struct object_id *real = oid;
1261 int already_retried = 0;
1262
1263 if (flags & OBJECT_INFO_LOOKUP_REPLACE)
1264 real = lookup_replace_object(r, oid);
1265
1266 if (is_null_oid(real))
1267 return -1;
1268
1269 if (!oi)
1270 oi = &blank_oi;
1271
1272 if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
1273 struct cached_object *co = find_cached_object(real);
1274 if (co) {
1275 if (oi->typep)
1276 *(oi->typep) = co->type;
1277 if (oi->sizep)
1278 *(oi->sizep) = co->size;
1279 if (oi->disk_sizep)
1280 *(oi->disk_sizep) = 0;
1281 if (oi->delta_base_sha1)
1282 hashclr(oi->delta_base_sha1);
1283 if (oi->type_name)
1284 strbuf_addstr(oi->type_name, type_name(co->type));
1285 if (oi->contentp)
1286 *oi->contentp = xmemdupz(co->buf, co->size);
1287 oi->whence = OI_CACHED;
1288 return 0;
1289 }
1290 }
1291
1292 while (1) {
1293 if (find_pack_entry(r, real, &e))
1294 break;
1295
1296 if (flags & OBJECT_INFO_IGNORE_LOOSE)
1297 return -1;
1298
1299 /* Most likely it's a loose object. */
1300 if (!sha1_loose_object_info(r, real->hash, oi, flags))
1301 return 0;
1302
1303 /* Not a loose object; someone else may have just packed it. */
1304 if (!(flags & OBJECT_INFO_QUICK)) {
1305 reprepare_packed_git(r);
1306 if (find_pack_entry(r, real, &e))
1307 break;
1308 }
1309
1310 /* Check if it is a missing object */
1311 if (fetch_if_missing && repository_format_partial_clone &&
1312 !already_retried && r == the_repository) {
1313 /*
1314 * TODO Investigate having fetch_object() return
1315 * TODO error/success and stopping the music here.
1316 * TODO Pass a repository struct through fetch_object,
1317 * such that arbitrary repositories work.
1318 */
1319 fetch_objects(repository_format_partial_clone, real, 1);
1320 already_retried = 1;
1321 continue;
1322 }
1323
1324 return -1;
1325 }
1326
1327 if (oi == &blank_oi)
1328 /*
1329 * We know that the caller doesn't actually need the
1330 * information below, so return early.
1331 */
1332 return 0;
1333 rtype = packed_object_info(r, e.p, e.offset, oi);
1334 if (rtype < 0) {
1335 mark_bad_packed_object(e.p, real->hash);
1336 return oid_object_info_extended(r, real, oi, 0);
1337 } else if (oi->whence == OI_PACKED) {
1338 oi->u.packed.offset = e.offset;
1339 oi->u.packed.pack = e.p;
1340 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
1341 rtype == OBJ_OFS_DELTA);
1342 }
1343
1344 return 0;
1345}
1346
1347/* returns enum object_type or negative */
1348int oid_object_info(struct repository *r,
1349 const struct object_id *oid,
1350 unsigned long *sizep)
1351{
1352 enum object_type type;
1353 struct object_info oi = OBJECT_INFO_INIT;
1354
1355 oi.typep = &type;
1356 oi.sizep = sizep;
1357 if (oid_object_info_extended(r, oid, &oi,
1358 OBJECT_INFO_LOOKUP_REPLACE) < 0)
1359 return -1;
1360 return type;
1361}
1362
1363static void *read_object(const unsigned char *sha1, enum object_type *type,
1364 unsigned long *size)
1365{
1366 struct object_id oid;
1367 struct object_info oi = OBJECT_INFO_INIT;
1368 void *content;
1369 oi.typep = type;
1370 oi.sizep = size;
1371 oi.contentp = &content;
1372
1373 hashcpy(oid.hash, sha1);
1374
1375 if (oid_object_info_extended(the_repository, &oid, &oi, 0) < 0)
1376 return NULL;
1377 return content;
1378}
1379
1380int pretend_object_file(void *buf, unsigned long len, enum object_type type,
1381 struct object_id *oid)
1382{
1383 struct cached_object *co;
1384
1385 hash_object_file(buf, len, type_name(type), oid);
1386 if (has_sha1_file(oid->hash) || find_cached_object(oid))
1387 return 0;
1388 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
1389 co = &cached_objects[cached_object_nr++];
1390 co->size = len;
1391 co->type = type;
1392 co->buf = xmalloc(len);
1393 memcpy(co->buf, buf, len);
1394 oidcpy(&co->oid, oid);
1395 return 0;
1396}
1397
1398/*
1399 * This function dies on corrupt objects; the callers who want to
1400 * deal with them should arrange to call read_object() and give error
1401 * messages themselves.
1402 */
1403void *read_object_file_extended(const struct object_id *oid,
1404 enum object_type *type,
1405 unsigned long *size,
1406 int lookup_replace)
1407{
1408 void *data;
1409 const struct packed_git *p;
1410 const char *path;
1411 struct stat st;
1412 const struct object_id *repl = lookup_replace ?
1413 lookup_replace_object(the_repository, oid) : oid;
1414
1415 errno = 0;
1416 data = read_object(repl->hash, type, size);
1417 if (data)
1418 return data;
1419
1420 if (errno && errno != ENOENT)
1421 die_errno(_("failed to read object %s"), oid_to_hex(oid));
1422
1423 /* die if we replaced an object with one that does not exist */
1424 if (repl != oid)
1425 die(_("replacement %s not found for %s"),
1426 oid_to_hex(repl), oid_to_hex(oid));
1427
1428 if (!stat_sha1_file(the_repository, repl->hash, &st, &path))
1429 die(_("loose object %s (stored in %s) is corrupt"),
1430 oid_to_hex(repl), path);
1431
1432 if ((p = has_packed_and_bad(repl->hash)) != NULL)
1433 die(_("packed object %s (stored in %s) is corrupt"),
1434 oid_to_hex(repl), p->pack_name);
1435
1436 return NULL;
1437}
1438
1439void *read_object_with_reference(const struct object_id *oid,
1440 const char *required_type_name,
1441 unsigned long *size,
1442 struct object_id *actual_oid_return)
1443{
1444 enum object_type type, required_type;
1445 void *buffer;
1446 unsigned long isize;
1447 struct object_id actual_oid;
1448
1449 required_type = type_from_string(required_type_name);
1450 oidcpy(&actual_oid, oid);
1451 while (1) {
1452 int ref_length = -1;
1453 const char *ref_type = NULL;
1454
1455 buffer = read_object_file(&actual_oid, &type, &isize);
1456 if (!buffer)
1457 return NULL;
1458 if (type == required_type) {
1459 *size = isize;
1460 if (actual_oid_return)
1461 oidcpy(actual_oid_return, &actual_oid);
1462 return buffer;
1463 }
1464 /* Handle references */
1465 else if (type == OBJ_COMMIT)
1466 ref_type = "tree ";
1467 else if (type == OBJ_TAG)
1468 ref_type = "object ";
1469 else {
1470 free(buffer);
1471 return NULL;
1472 }
1473 ref_length = strlen(ref_type);
1474
1475 if (ref_length + the_hash_algo->hexsz > isize ||
1476 memcmp(buffer, ref_type, ref_length) ||
1477 get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
1478 free(buffer);
1479 return NULL;
1480 }
1481 free(buffer);
1482 /* Now we have the ID of the referred-to object in
1483 * actual_oid. Check again. */
1484 }
1485}
1486
1487static void write_object_file_prepare(const void *buf, unsigned long len,
1488 const char *type, struct object_id *oid,
1489 char *hdr, int *hdrlen)
1490{
1491 git_hash_ctx c;
1492
1493 /* Generate the header */
1494 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
1495
1496 /* Sha1.. */
1497 the_hash_algo->init_fn(&c);
1498 the_hash_algo->update_fn(&c, hdr, *hdrlen);
1499 the_hash_algo->update_fn(&c, buf, len);
1500 the_hash_algo->final_fn(oid->hash, &c);
1501}
1502
1503/*
1504 * Move the just written object into its final resting place.
1505 */
1506int finalize_object_file(const char *tmpfile, const char *filename)
1507{
1508 int ret = 0;
1509
1510 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
1511 goto try_rename;
1512 else if (link(tmpfile, filename))
1513 ret = errno;
1514
1515 /*
1516 * Coda hack - coda doesn't like cross-directory links,
1517 * so we fall back to a rename, which will mean that it
1518 * won't be able to check collisions, but that's not a
1519 * big deal.
1520 *
1521 * The same holds for FAT formatted media.
1522 *
1523 * When this succeeds, we just return. We have nothing
1524 * left to unlink.
1525 */
1526 if (ret && ret != EEXIST) {
1527 try_rename:
1528 if (!rename(tmpfile, filename))
1529 goto out;
1530 ret = errno;
1531 }
1532 unlink_or_warn(tmpfile);
1533 if (ret) {
1534 if (ret != EEXIST) {
1535 return error_errno(_("unable to write sha1 filename %s"), filename);
1536 }
1537 /* FIXME!!! Collision check here ? */
1538 }
1539
1540out:
1541 if (adjust_shared_perm(filename))
1542 return error(_("unable to set permission to '%s'"), filename);
1543 return 0;
1544}
1545
1546static int write_buffer(int fd, const void *buf, size_t len)
1547{
1548 if (write_in_full(fd, buf, len) < 0)
1549 return error_errno(_("file write error"));
1550 return 0;
1551}
1552
1553int hash_object_file(const void *buf, unsigned long len, const char *type,
1554 struct object_id *oid)
1555{
1556 char hdr[MAX_HEADER_LEN];
1557 int hdrlen = sizeof(hdr);
1558 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1559 return 0;
1560}
1561
1562/* Finalize a file on disk, and close it. */
1563static void close_sha1_file(int fd)
1564{
1565 if (fsync_object_files)
1566 fsync_or_die(fd, "sha1 file");
1567 if (close(fd) != 0)
1568 die_errno(_("error when closing sha1 file"));
1569}
1570
1571/* Size of directory component, including the ending '/' */
1572static inline int directory_size(const char *filename)
1573{
1574 const char *s = strrchr(filename, '/');
1575 if (!s)
1576 return 0;
1577 return s - filename + 1;
1578}
1579
1580/*
1581 * This creates a temporary file in the same directory as the final
1582 * 'filename'
1583 *
1584 * We want to avoid cross-directory filename renames, because those
1585 * can have problems on various filesystems (FAT, NFS, Coda).
1586 */
1587static int create_tmpfile(struct strbuf *tmp, const char *filename)
1588{
1589 int fd, dirlen = directory_size(filename);
1590
1591 strbuf_reset(tmp);
1592 strbuf_add(tmp, filename, dirlen);
1593 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
1594 fd = git_mkstemp_mode(tmp->buf, 0444);
1595 if (fd < 0 && dirlen && errno == ENOENT) {
1596 /*
1597 * Make sure the directory exists; note that the contents
1598 * of the buffer are undefined after mkstemp returns an
1599 * error, so we have to rewrite the whole buffer from
1600 * scratch.
1601 */
1602 strbuf_reset(tmp);
1603 strbuf_add(tmp, filename, dirlen - 1);
1604 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
1605 return -1;
1606 if (adjust_shared_perm(tmp->buf))
1607 return -1;
1608
1609 /* Try again */
1610 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
1611 fd = git_mkstemp_mode(tmp->buf, 0444);
1612 }
1613 return fd;
1614}
1615
1616static int write_loose_object(const struct object_id *oid, char *hdr,
1617 int hdrlen, const void *buf, unsigned long len,
1618 time_t mtime)
1619{
1620 int fd, ret;
1621 unsigned char compressed[4096];
1622 git_zstream stream;
1623 git_hash_ctx c;
1624 struct object_id parano_oid;
1625 static struct strbuf tmp_file = STRBUF_INIT;
1626 static struct strbuf filename = STRBUF_INIT;
1627
1628 loose_object_path(the_repository, &filename, oid->hash);
1629
1630 fd = create_tmpfile(&tmp_file, filename.buf);
1631 if (fd < 0) {
1632 if (errno == EACCES)
1633 return error(_("insufficient permission for adding an object to repository database %s"), get_object_directory());
1634 else
1635 return error_errno(_("unable to create temporary file"));
1636 }
1637
1638 /* Set it up */
1639 git_deflate_init(&stream, zlib_compression_level);
1640 stream.next_out = compressed;
1641 stream.avail_out = sizeof(compressed);
1642 the_hash_algo->init_fn(&c);
1643
1644 /* First header.. */
1645 stream.next_in = (unsigned char *)hdr;
1646 stream.avail_in = hdrlen;
1647 while (git_deflate(&stream, 0) == Z_OK)
1648 ; /* nothing */
1649 the_hash_algo->update_fn(&c, hdr, hdrlen);
1650
1651 /* Then the data itself.. */
1652 stream.next_in = (void *)buf;
1653 stream.avail_in = len;
1654 do {
1655 unsigned char *in0 = stream.next_in;
1656 ret = git_deflate(&stream, Z_FINISH);
1657 the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
1658 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
1659 die(_("unable to write sha1 file"));
1660 stream.next_out = compressed;
1661 stream.avail_out = sizeof(compressed);
1662 } while (ret == Z_OK);
1663
1664 if (ret != Z_STREAM_END)
1665 die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
1666 ret);
1667 ret = git_deflate_end_gently(&stream);
1668 if (ret != Z_OK)
1669 die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
1670 ret);
1671 the_hash_algo->final_fn(parano_oid.hash, &c);
1672 if (!oideq(oid, ¶no_oid))
1673 die(_("confused by unstable object source data for %s"),
1674 oid_to_hex(oid));
1675
1676 close_sha1_file(fd);
1677
1678 if (mtime) {
1679 struct utimbuf utb;
1680 utb.actime = mtime;
1681 utb.modtime = mtime;
1682 if (utime(tmp_file.buf, &utb) < 0)
1683 warning_errno(_("failed utime() on %s"), tmp_file.buf);
1684 }
1685
1686 return finalize_object_file(tmp_file.buf, filename.buf);
1687}
1688
1689static int freshen_loose_object(const struct object_id *oid)
1690{
1691 return check_and_freshen(oid, 1);
1692}
1693
1694static int freshen_packed_object(const struct object_id *oid)
1695{
1696 struct pack_entry e;
1697 if (!find_pack_entry(the_repository, oid, &e))
1698 return 0;
1699 if (e.p->freshened)
1700 return 1;
1701 if (!freshen_file(e.p->pack_name))
1702 return 0;
1703 e.p->freshened = 1;
1704 return 1;
1705}
1706
1707int write_object_file(const void *buf, unsigned long len, const char *type,
1708 struct object_id *oid)
1709{
1710 char hdr[MAX_HEADER_LEN];
1711 int hdrlen = sizeof(hdr);
1712
1713 /* Normally if we have it in the pack then we do not bother writing
1714 * it out into .git/objects/??/?{38} file.
1715 */
1716 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1717 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1718 return 0;
1719 return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
1720}
1721
1722int hash_object_file_literally(const void *buf, unsigned long len,
1723 const char *type, struct object_id *oid,
1724 unsigned flags)
1725{
1726 char *header;
1727 int hdrlen, status = 0;
1728
1729 /* type string, SP, %lu of the length plus NUL must fit this */
1730 hdrlen = strlen(type) + MAX_HEADER_LEN;
1731 header = xmalloc(hdrlen);
1732 write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
1733
1734 if (!(flags & HASH_WRITE_OBJECT))
1735 goto cleanup;
1736 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1737 goto cleanup;
1738 status = write_loose_object(oid, header, hdrlen, buf, len, 0);
1739
1740cleanup:
1741 free(header);
1742 return status;
1743}
1744
1745int force_object_loose(const struct object_id *oid, time_t mtime)
1746{
1747 void *buf;
1748 unsigned long len;
1749 enum object_type type;
1750 char hdr[MAX_HEADER_LEN];
1751 int hdrlen;
1752 int ret;
1753
1754 if (has_loose_object(oid))
1755 return 0;
1756 buf = read_object(oid->hash, &type, &len);
1757 if (!buf)
1758 return error(_("cannot read sha1_file for %s"), oid_to_hex(oid));
1759 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
1760 ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
1761 free(buf);
1762
1763 return ret;
1764}
1765
1766int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
1767{
1768 struct object_id oid;
1769 if (!startup_info->have_repository)
1770 return 0;
1771 hashcpy(oid.hash, sha1);
1772 return oid_object_info_extended(the_repository, &oid, NULL,
1773 flags | OBJECT_INFO_SKIP_CACHED) >= 0;
1774}
1775
1776int has_object_file(const struct object_id *oid)
1777{
1778 return has_sha1_file(oid->hash);
1779}
1780
1781int has_object_file_with_flags(const struct object_id *oid, int flags)
1782{
1783 return has_sha1_file_with_flags(oid->hash, flags);
1784}
1785
1786static void check_tree(const void *buf, size_t size)
1787{
1788 struct tree_desc desc;
1789 struct name_entry entry;
1790
1791 init_tree_desc(&desc, buf, size);
1792 while (tree_entry(&desc, &entry))
1793 /* do nothing
1794 * tree_entry() will die() on malformed entries */
1795 ;
1796}
1797
1798static void check_commit(const void *buf, size_t size)
1799{
1800 struct commit c;
1801 memset(&c, 0, sizeof(c));
1802 if (parse_commit_buffer(the_repository, &c, buf, size, 0))
1803 die(_("corrupt commit"));
1804}
1805
1806static void check_tag(const void *buf, size_t size)
1807{
1808 struct tag t;
1809 memset(&t, 0, sizeof(t));
1810 if (parse_tag_buffer(the_repository, &t, buf, size))
1811 die(_("corrupt tag"));
1812}
1813
1814static int index_mem(struct index_state *istate,
1815 struct object_id *oid, void *buf, size_t size,
1816 enum object_type type,
1817 const char *path, unsigned flags)
1818{
1819 int ret, re_allocated = 0;
1820 int write_object = flags & HASH_WRITE_OBJECT;
1821
1822 if (!type)
1823 type = OBJ_BLOB;
1824
1825 /*
1826 * Convert blobs to git internal format
1827 */
1828 if ((type == OBJ_BLOB) && path) {
1829 struct strbuf nbuf = STRBUF_INIT;
1830 if (convert_to_git(istate, path, buf, size, &nbuf,
1831 get_conv_flags(flags))) {
1832 buf = strbuf_detach(&nbuf, &size);
1833 re_allocated = 1;
1834 }
1835 }
1836 if (flags & HASH_FORMAT_CHECK) {
1837 if (type == OBJ_TREE)
1838 check_tree(buf, size);
1839 if (type == OBJ_COMMIT)
1840 check_commit(buf, size);
1841 if (type == OBJ_TAG)
1842 check_tag(buf, size);
1843 }
1844
1845 if (write_object)
1846 ret = write_object_file(buf, size, type_name(type), oid);
1847 else
1848 ret = hash_object_file(buf, size, type_name(type), oid);
1849 if (re_allocated)
1850 free(buf);
1851 return ret;
1852}
1853
1854static int index_stream_convert_blob(struct index_state *istate,
1855 struct object_id *oid,
1856 int fd,
1857 const char *path,
1858 unsigned flags)
1859{
1860 int ret;
1861 const int write_object = flags & HASH_WRITE_OBJECT;
1862 struct strbuf sbuf = STRBUF_INIT;
1863
1864 assert(path);
1865 assert(would_convert_to_git_filter_fd(istate, path));
1866
1867 convert_to_git_filter_fd(istate, path, fd, &sbuf,
1868 get_conv_flags(flags));
1869
1870 if (write_object)
1871 ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1872 oid);
1873 else
1874 ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1875 oid);
1876 strbuf_release(&sbuf);
1877 return ret;
1878}
1879
1880static int index_pipe(struct index_state *istate, struct object_id *oid,
1881 int fd, enum object_type type,
1882 const char *path, unsigned flags)
1883{
1884 struct strbuf sbuf = STRBUF_INIT;
1885 int ret;
1886
1887 if (strbuf_read(&sbuf, fd, 4096) >= 0)
1888 ret = index_mem(istate, oid, sbuf.buf, sbuf.len, type, path, flags);
1889 else
1890 ret = -1;
1891 strbuf_release(&sbuf);
1892 return ret;
1893}
1894
1895#define SMALL_FILE_SIZE (32*1024)
1896
1897static int index_core(struct index_state *istate,
1898 struct object_id *oid, int fd, size_t size,
1899 enum object_type type, const char *path,
1900 unsigned flags)
1901{
1902 int ret;
1903
1904 if (!size) {
1905 ret = index_mem(istate, oid, "", size, type, path, flags);
1906 } else if (size <= SMALL_FILE_SIZE) {
1907 char *buf = xmalloc(size);
1908 ssize_t read_result = read_in_full(fd, buf, size);
1909 if (read_result < 0)
1910 ret = error_errno(_("read error while indexing %s"),
1911 path ? path : "<unknown>");
1912 else if (read_result != size)
1913 ret = error(_("short read while indexing %s"),
1914 path ? path : "<unknown>");
1915 else
1916 ret = index_mem(istate, oid, buf, size, type, path, flags);
1917 free(buf);
1918 } else {
1919 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1920 ret = index_mem(istate, oid, buf, size, type, path, flags);
1921 munmap(buf, size);
1922 }
1923 return ret;
1924}
1925
1926/*
1927 * This creates one packfile per large blob unless bulk-checkin
1928 * machinery is "plugged".
1929 *
1930 * This also bypasses the usual "convert-to-git" dance, and that is on
1931 * purpose. We could write a streaming version of the converting
1932 * functions and insert that before feeding the data to fast-import
1933 * (or equivalent in-core API described above). However, that is
1934 * somewhat complicated, as we do not know the size of the filter
1935 * result, which we need to know beforehand when writing a git object.
1936 * Since the primary motivation for trying to stream from the working
1937 * tree file and to avoid mmaping it in core is to deal with large
1938 * binary blobs, they generally do not want to get any conversion, and
1939 * callers should avoid this code path when filters are requested.
1940 */
1941static int index_stream(struct object_id *oid, int fd, size_t size,
1942 enum object_type type, const char *path,
1943 unsigned flags)
1944{
1945 return index_bulk_checkin(oid, fd, size, type, path, flags);
1946}
1947
1948int index_fd(struct index_state *istate, struct object_id *oid,
1949 int fd, struct stat *st,
1950 enum object_type type, const char *path, unsigned flags)
1951{
1952 int ret;
1953
1954 /*
1955 * Call xsize_t() only when needed to avoid potentially unnecessary
1956 * die() for large files.
1957 */
1958 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
1959 ret = index_stream_convert_blob(istate, oid, fd, path, flags);
1960 else if (!S_ISREG(st->st_mode))
1961 ret = index_pipe(istate, oid, fd, type, path, flags);
1962 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
1963 (path && would_convert_to_git(istate, path)))
1964 ret = index_core(istate, oid, fd, xsize_t(st->st_size),
1965 type, path, flags);
1966 else
1967 ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
1968 flags);
1969 close(fd);
1970 return ret;
1971}
1972
1973int index_path(struct index_state *istate, struct object_id *oid,
1974 const char *path, struct stat *st, unsigned flags)
1975{
1976 int fd;
1977 struct strbuf sb = STRBUF_INIT;
1978 int rc = 0;
1979
1980 switch (st->st_mode & S_IFMT) {
1981 case S_IFREG:
1982 fd = open(path, O_RDONLY);
1983 if (fd < 0)
1984 return error_errno("open(\"%s\")", path);
1985 if (index_fd(istate, oid, fd, st, OBJ_BLOB, path, flags) < 0)
1986 return error(_("%s: failed to insert into database"),
1987 path);
1988 break;
1989 case S_IFLNK:
1990 if (strbuf_readlink(&sb, path, st->st_size))
1991 return error_errno("readlink(\"%s\")", path);
1992 if (!(flags & HASH_WRITE_OBJECT))
1993 hash_object_file(sb.buf, sb.len, blob_type, oid);
1994 else if (write_object_file(sb.buf, sb.len, blob_type, oid))
1995 rc = error(_("%s: failed to insert into database"), path);
1996 strbuf_release(&sb);
1997 break;
1998 case S_IFDIR:
1999 return resolve_gitlink_ref(path, "HEAD", oid);
2000 default:
2001 return error(_("%s: unsupported file type"), path);
2002 }
2003 return rc;
2004}
2005
2006int read_pack_header(int fd, struct pack_header *header)
2007{
2008 if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
2009 /* "eof before pack header was fully read" */
2010 return PH_ERROR_EOF;
2011
2012 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2013 /* "protocol error (pack signature mismatch detected)" */
2014 return PH_ERROR_PACK_SIGNATURE;
2015 if (!pack_version_ok(header->hdr_version))
2016 /* "protocol error (pack version unsupported)" */
2017 return PH_ERROR_PROTOCOL;
2018 return 0;
2019}
2020
2021void assert_oid_type(const struct object_id *oid, enum object_type expect)
2022{
2023 enum object_type type = oid_object_info(the_repository, oid, NULL);
2024 if (type < 0)
2025 die(_("%s is not a valid object"), oid_to_hex(oid));
2026 if (type != expect)
2027 die(_("%s is not a valid '%s' object"), oid_to_hex(oid),
2028 type_name(expect));
2029}
2030
2031int for_each_file_in_obj_subdir(unsigned int subdir_nr,
2032 struct strbuf *path,
2033 each_loose_object_fn obj_cb,
2034 each_loose_cruft_fn cruft_cb,
2035 each_loose_subdir_fn subdir_cb,
2036 void *data)
2037{
2038 size_t origlen, baselen;
2039 DIR *dir;
2040 struct dirent *de;
2041 int r = 0;
2042 struct object_id oid;
2043
2044 if (subdir_nr > 0xff)
2045 BUG("invalid loose object subdirectory: %x", subdir_nr);
2046
2047 origlen = path->len;
2048 strbuf_complete(path, '/');
2049 strbuf_addf(path, "%02x", subdir_nr);
2050
2051 dir = opendir(path->buf);
2052 if (!dir) {
2053 if (errno != ENOENT)
2054 r = error_errno(_("unable to open %s"), path->buf);
2055 strbuf_setlen(path, origlen);
2056 return r;
2057 }
2058
2059 oid.hash[0] = subdir_nr;
2060 strbuf_addch(path, '/');
2061 baselen = path->len;
2062
2063 while ((de = readdir(dir))) {
2064 size_t namelen;
2065 if (is_dot_or_dotdot(de->d_name))
2066 continue;
2067
2068 namelen = strlen(de->d_name);
2069 strbuf_setlen(path, baselen);
2070 strbuf_add(path, de->d_name, namelen);
2071 if (namelen == the_hash_algo->hexsz - 2 &&
2072 !hex_to_bytes(oid.hash + 1, de->d_name,
2073 the_hash_algo->rawsz - 1)) {
2074 if (obj_cb) {
2075 r = obj_cb(&oid, path->buf, data);
2076 if (r)
2077 break;
2078 }
2079 continue;
2080 }
2081
2082 if (cruft_cb) {
2083 r = cruft_cb(de->d_name, path->buf, data);
2084 if (r)
2085 break;
2086 }
2087 }
2088 closedir(dir);
2089
2090 strbuf_setlen(path, baselen - 1);
2091 if (!r && subdir_cb)
2092 r = subdir_cb(subdir_nr, path->buf, data);
2093
2094 strbuf_setlen(path, origlen);
2095
2096 return r;
2097}
2098
2099int for_each_loose_file_in_objdir_buf(struct strbuf *path,
2100 each_loose_object_fn obj_cb,
2101 each_loose_cruft_fn cruft_cb,
2102 each_loose_subdir_fn subdir_cb,
2103 void *data)
2104{
2105 int r = 0;
2106 int i;
2107
2108 for (i = 0; i < 256; i++) {
2109 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
2110 subdir_cb, data);
2111 if (r)
2112 break;
2113 }
2114
2115 return r;
2116}
2117
2118int for_each_loose_file_in_objdir(const char *path,
2119 each_loose_object_fn obj_cb,
2120 each_loose_cruft_fn cruft_cb,
2121 each_loose_subdir_fn subdir_cb,
2122 void *data)
2123{
2124 struct strbuf buf = STRBUF_INIT;
2125 int r;
2126
2127 strbuf_addstr(&buf, path);
2128 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
2129 subdir_cb, data);
2130 strbuf_release(&buf);
2131
2132 return r;
2133}
2134
2135struct loose_alt_odb_data {
2136 each_loose_object_fn *cb;
2137 void *data;
2138};
2139
2140static int loose_from_alt_odb(struct object_directory *odb,
2141 void *vdata)
2142{
2143 struct loose_alt_odb_data *data = vdata;
2144 struct strbuf buf = STRBUF_INIT;
2145 int r;
2146
2147 strbuf_addstr(&buf, odb->path);
2148 r = for_each_loose_file_in_objdir_buf(&buf,
2149 data->cb, NULL, NULL,
2150 data->data);
2151 strbuf_release(&buf);
2152 return r;
2153}
2154
2155int for_each_loose_object(each_loose_object_fn cb, void *data,
2156 enum for_each_object_flags flags)
2157{
2158 struct loose_alt_odb_data alt;
2159 int r;
2160
2161 r = for_each_loose_file_in_objdir(get_object_directory(),
2162 cb, NULL, NULL, data);
2163 if (r)
2164 return r;
2165
2166 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
2167 return 0;
2168
2169 alt.cb = cb;
2170 alt.data = data;
2171 return foreach_alt_odb(loose_from_alt_odb, &alt);
2172}
2173
2174static int check_stream_sha1(git_zstream *stream,
2175 const char *hdr,
2176 unsigned long size,
2177 const char *path,
2178 const unsigned char *expected_sha1)
2179{
2180 git_hash_ctx c;
2181 unsigned char real_sha1[GIT_MAX_RAWSZ];
2182 unsigned char buf[4096];
2183 unsigned long total_read;
2184 int status = Z_OK;
2185
2186 the_hash_algo->init_fn(&c);
2187 the_hash_algo->update_fn(&c, hdr, stream->total_out);
2188
2189 /*
2190 * We already read some bytes into hdr, but the ones up to the NUL
2191 * do not count against the object's content size.
2192 */
2193 total_read = stream->total_out - strlen(hdr) - 1;
2194
2195 /*
2196 * This size comparison must be "<=" to read the final zlib packets;
2197 * see the comment in unpack_sha1_rest for details.
2198 */
2199 while (total_read <= size &&
2200 (status == Z_OK || status == Z_BUF_ERROR)) {
2201 stream->next_out = buf;
2202 stream->avail_out = sizeof(buf);
2203 if (size - total_read < stream->avail_out)
2204 stream->avail_out = size - total_read;
2205 status = git_inflate(stream, Z_FINISH);
2206 the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
2207 total_read += stream->next_out - buf;
2208 }
2209 git_inflate_end(stream);
2210
2211 if (status != Z_STREAM_END) {
2212 error(_("corrupt loose object '%s'"), sha1_to_hex(expected_sha1));
2213 return -1;
2214 }
2215 if (stream->avail_in) {
2216 error(_("garbage at end of loose object '%s'"),
2217 sha1_to_hex(expected_sha1));
2218 return -1;
2219 }
2220
2221 the_hash_algo->final_fn(real_sha1, &c);
2222 if (!hasheq(expected_sha1, real_sha1)) {
2223 error(_("sha1 mismatch for %s (expected %s)"), path,
2224 sha1_to_hex(expected_sha1));
2225 return -1;
2226 }
2227
2228 return 0;
2229}
2230
2231int read_loose_object(const char *path,
2232 const struct object_id *expected_oid,
2233 enum object_type *type,
2234 unsigned long *size,
2235 void **contents)
2236{
2237 int ret = -1;
2238 void *map = NULL;
2239 unsigned long mapsize;
2240 git_zstream stream;
2241 char hdr[MAX_HEADER_LEN];
2242
2243 *contents = NULL;
2244
2245 map = map_sha1_file_1(the_repository, path, NULL, &mapsize);
2246 if (!map) {
2247 error_errno(_("unable to mmap %s"), path);
2248 goto out;
2249 }
2250
2251 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
2252 error(_("unable to unpack header of %s"), path);
2253 goto out;
2254 }
2255
2256 *type = parse_sha1_header(hdr, size);
2257 if (*type < 0) {
2258 error(_("unable to parse header of %s"), path);
2259 git_inflate_end(&stream);
2260 goto out;
2261 }
2262
2263 if (*type == OBJ_BLOB && *size > big_file_threshold) {
2264 if (check_stream_sha1(&stream, hdr, *size, path, expected_oid->hash) < 0)
2265 goto out;
2266 } else {
2267 *contents = unpack_sha1_rest(&stream, hdr, *size, expected_oid->hash);
2268 if (!*contents) {
2269 error(_("unable to unpack contents of %s"), path);
2270 git_inflate_end(&stream);
2271 goto out;
2272 }
2273 if (check_object_signature(expected_oid, *contents,
2274 *size, type_name(*type))) {
2275 error(_("sha1 mismatch for %s (expected %s)"), path,
2276 oid_to_hex(expected_oid));
2277 free(*contents);
2278 goto out;
2279 }
2280 }
2281
2282 ret = 0; /* everything checks out */
2283
2284out:
2285 if (map)
2286 munmap(map, mapsize);
2287 return ret;
2288}