7a121f39e8217d74fc185bc37bc10c323487967a
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_object_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_loose_path(struct strbuf *buf, const struct object_id *oid)
337{
338 int i;
339 for (i = 0; i < the_hash_algo->rawsz; i++) {
340 static char hex[] = "0123456789abcdef";
341 unsigned int val = oid->hash[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
349static const char *odb_loose_path(struct object_directory *odb,
350 struct strbuf *buf,
351 const struct object_id *oid)
352{
353 strbuf_reset(buf);
354 strbuf_addstr(buf, odb->path);
355 strbuf_addch(buf, '/');
356 fill_loose_path(buf, oid);
357 return buf->buf;
358}
359
360const char *loose_object_path(struct repository *r, struct strbuf *buf,
361 const struct object_id *oid)
362{
363 return odb_loose_path(r->objects->odb, buf, oid);
364}
365
366/*
367 * Return non-zero iff the path is usable as an alternate object database.
368 */
369static int alt_odb_usable(struct raw_object_store *o,
370 struct strbuf *path,
371 const char *normalized_objdir)
372{
373 struct object_directory *odb;
374
375 /* Detect cases where alternate disappeared */
376 if (!is_directory(path->buf)) {
377 error(_("object directory %s does not exist; "
378 "check .git/objects/info/alternates"),
379 path->buf);
380 return 0;
381 }
382
383 /*
384 * Prevent the common mistake of listing the same
385 * thing twice, or object directory itself.
386 */
387 for (odb = o->odb; odb; odb = odb->next) {
388 if (!fspathcmp(path->buf, odb->path))
389 return 0;
390 }
391 if (!fspathcmp(path->buf, normalized_objdir))
392 return 0;
393
394 return 1;
395}
396
397/*
398 * Prepare alternate object database registry.
399 *
400 * The variable alt_odb_list points at the list of struct
401 * object_directory. The elements on this list come from
402 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
403 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
404 * whose contents is similar to that environment variable but can be
405 * LF separated. Its base points at a statically allocated buffer that
406 * contains "/the/directory/corresponding/to/.git/objects/...", while
407 * its name points just after the slash at the end of ".git/objects/"
408 * in the example above, and has enough space to hold 40-byte hex
409 * SHA1, an extra slash for the first level indirection, and the
410 * terminating NUL.
411 */
412static void read_info_alternates(struct repository *r,
413 const char *relative_base,
414 int depth);
415static int link_alt_odb_entry(struct repository *r, const char *entry,
416 const char *relative_base, int depth, const char *normalized_objdir)
417{
418 struct object_directory *ent;
419 struct strbuf pathbuf = STRBUF_INIT;
420
421 if (!is_absolute_path(entry) && relative_base) {
422 strbuf_realpath(&pathbuf, relative_base, 1);
423 strbuf_addch(&pathbuf, '/');
424 }
425 strbuf_addstr(&pathbuf, entry);
426
427 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
428 error(_("unable to normalize alternate object path: %s"),
429 pathbuf.buf);
430 strbuf_release(&pathbuf);
431 return -1;
432 }
433
434 /*
435 * The trailing slash after the directory name is given by
436 * this function at the end. Remove duplicates.
437 */
438 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
439 strbuf_setlen(&pathbuf, pathbuf.len - 1);
440
441 if (!alt_odb_usable(r->objects, &pathbuf, normalized_objdir)) {
442 strbuf_release(&pathbuf);
443 return -1;
444 }
445
446 ent = xcalloc(1, sizeof(*ent));
447 ent->path = xstrdup(pathbuf.buf);
448
449 /* add the alternate entry */
450 *r->objects->odb_tail = ent;
451 r->objects->odb_tail = &(ent->next);
452 ent->next = NULL;
453
454 /* recursively add alternates */
455 read_info_alternates(r, pathbuf.buf, depth + 1);
456
457 strbuf_release(&pathbuf);
458 return 0;
459}
460
461static const char *parse_alt_odb_entry(const char *string,
462 int sep,
463 struct strbuf *out)
464{
465 const char *end;
466
467 strbuf_reset(out);
468
469 if (*string == '#') {
470 /* comment; consume up to next separator */
471 end = strchrnul(string, sep);
472 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
473 /*
474 * quoted path; unquote_c_style has copied the
475 * data for us and set "end". Broken quoting (e.g.,
476 * an entry that doesn't end with a quote) falls
477 * back to the unquoted case below.
478 */
479 } else {
480 /* normal, unquoted path */
481 end = strchrnul(string, sep);
482 strbuf_add(out, string, end - string);
483 }
484
485 if (*end)
486 end++;
487 return end;
488}
489
490static void link_alt_odb_entries(struct repository *r, const char *alt,
491 int sep, const char *relative_base, int depth)
492{
493 struct strbuf objdirbuf = STRBUF_INIT;
494 struct strbuf entry = STRBUF_INIT;
495
496 if (!alt || !*alt)
497 return;
498
499 if (depth > 5) {
500 error(_("%s: ignoring alternate object stores, nesting too deep"),
501 relative_base);
502 return;
503 }
504
505 strbuf_add_absolute_path(&objdirbuf, r->objects->odb->path);
506 if (strbuf_normalize_path(&objdirbuf) < 0)
507 die(_("unable to normalize object directory: %s"),
508 objdirbuf.buf);
509
510 while (*alt) {
511 alt = parse_alt_odb_entry(alt, sep, &entry);
512 if (!entry.len)
513 continue;
514 link_alt_odb_entry(r, entry.buf,
515 relative_base, depth, objdirbuf.buf);
516 }
517 strbuf_release(&entry);
518 strbuf_release(&objdirbuf);
519}
520
521static void read_info_alternates(struct repository *r,
522 const char *relative_base,
523 int depth)
524{
525 char *path;
526 struct strbuf buf = STRBUF_INIT;
527
528 path = xstrfmt("%s/info/alternates", relative_base);
529 if (strbuf_read_file(&buf, path, 1024) < 0) {
530 warn_on_fopen_errors(path);
531 free(path);
532 return;
533 }
534
535 link_alt_odb_entries(r, buf.buf, '\n', relative_base, depth);
536 strbuf_release(&buf);
537 free(path);
538}
539
540void add_to_alternates_file(const char *reference)
541{
542 struct lock_file lock = LOCK_INIT;
543 char *alts = git_pathdup("objects/info/alternates");
544 FILE *in, *out;
545 int found = 0;
546
547 hold_lock_file_for_update(&lock, alts, LOCK_DIE_ON_ERROR);
548 out = fdopen_lock_file(&lock, "w");
549 if (!out)
550 die_errno(_("unable to fdopen alternates lockfile"));
551
552 in = fopen(alts, "r");
553 if (in) {
554 struct strbuf line = STRBUF_INIT;
555
556 while (strbuf_getline(&line, in) != EOF) {
557 if (!strcmp(reference, line.buf)) {
558 found = 1;
559 break;
560 }
561 fprintf_or_die(out, "%s\n", line.buf);
562 }
563
564 strbuf_release(&line);
565 fclose(in);
566 }
567 else if (errno != ENOENT)
568 die_errno(_("unable to read alternates file"));
569
570 if (found) {
571 rollback_lock_file(&lock);
572 } else {
573 fprintf_or_die(out, "%s\n", reference);
574 if (commit_lock_file(&lock))
575 die_errno(_("unable to move new alternates file into place"));
576 if (the_repository->objects->loaded_alternates)
577 link_alt_odb_entries(the_repository, reference,
578 '\n', NULL, 0);
579 }
580 free(alts);
581}
582
583void add_to_alternates_memory(const char *reference)
584{
585 /*
586 * Make sure alternates are initialized, or else our entry may be
587 * overwritten when they are.
588 */
589 prepare_alt_odb(the_repository);
590
591 link_alt_odb_entries(the_repository, reference,
592 '\n', NULL, 0);
593}
594
595/*
596 * Compute the exact path an alternate is at and returns it. In case of
597 * error NULL is returned and the human readable error is added to `err`
598 * `path` may be relative and should point to $GIT_DIR.
599 * `err` must not be null.
600 */
601char *compute_alternate_path(const char *path, struct strbuf *err)
602{
603 char *ref_git = NULL;
604 const char *repo, *ref_git_s;
605 int seen_error = 0;
606
607 ref_git_s = real_path_if_valid(path);
608 if (!ref_git_s) {
609 seen_error = 1;
610 strbuf_addf(err, _("path '%s' does not exist"), path);
611 goto out;
612 } else
613 /*
614 * Beware: read_gitfile(), real_path() and mkpath()
615 * return static buffer
616 */
617 ref_git = xstrdup(ref_git_s);
618
619 repo = read_gitfile(ref_git);
620 if (!repo)
621 repo = read_gitfile(mkpath("%s/.git", ref_git));
622 if (repo) {
623 free(ref_git);
624 ref_git = xstrdup(repo);
625 }
626
627 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
628 char *ref_git_git = mkpathdup("%s/.git", ref_git);
629 free(ref_git);
630 ref_git = ref_git_git;
631 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
632 struct strbuf sb = STRBUF_INIT;
633 seen_error = 1;
634 if (get_common_dir(&sb, ref_git)) {
635 strbuf_addf(err,
636 _("reference repository '%s' as a linked "
637 "checkout is not supported yet."),
638 path);
639 goto out;
640 }
641
642 strbuf_addf(err, _("reference repository '%s' is not a "
643 "local repository."), path);
644 goto out;
645 }
646
647 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
648 strbuf_addf(err, _("reference repository '%s' is shallow"),
649 path);
650 seen_error = 1;
651 goto out;
652 }
653
654 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
655 strbuf_addf(err,
656 _("reference repository '%s' is grafted"),
657 path);
658 seen_error = 1;
659 goto out;
660 }
661
662out:
663 if (seen_error) {
664 FREE_AND_NULL(ref_git);
665 }
666
667 return ref_git;
668}
669
670int foreach_alt_odb(alt_odb_fn fn, void *cb)
671{
672 struct object_directory *ent;
673 int r = 0;
674
675 prepare_alt_odb(the_repository);
676 for (ent = the_repository->objects->odb->next; ent; ent = ent->next) {
677 r = fn(ent, cb);
678 if (r)
679 break;
680 }
681 return r;
682}
683
684void prepare_alt_odb(struct repository *r)
685{
686 if (r->objects->loaded_alternates)
687 return;
688
689 link_alt_odb_entries(r, r->objects->alternate_db, PATH_SEP, NULL, 0);
690
691 read_info_alternates(r, r->objects->odb->path, 0);
692 r->objects->loaded_alternates = 1;
693}
694
695/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
696static int freshen_file(const char *fn)
697{
698 struct utimbuf t;
699 t.actime = t.modtime = time(NULL);
700 return !utime(fn, &t);
701}
702
703/*
704 * All of the check_and_freshen functions return 1 if the file exists and was
705 * freshened (if freshening was requested), 0 otherwise. If they return
706 * 0, you should not assume that it is safe to skip a write of the object (it
707 * either does not exist on disk, or has a stale mtime and may be subject to
708 * pruning).
709 */
710int check_and_freshen_file(const char *fn, int freshen)
711{
712 if (access(fn, F_OK))
713 return 0;
714 if (freshen && !freshen_file(fn))
715 return 0;
716 return 1;
717}
718
719static int check_and_freshen_odb(struct object_directory *odb,
720 const struct object_id *oid,
721 int freshen)
722{
723 static struct strbuf path = STRBUF_INIT;
724 odb_loose_path(odb, &path, oid);
725 return check_and_freshen_file(path.buf, freshen);
726}
727
728static int check_and_freshen_local(const struct object_id *oid, int freshen)
729{
730 return check_and_freshen_odb(the_repository->objects->odb, oid, freshen);
731}
732
733static int check_and_freshen_nonlocal(const struct object_id *oid, int freshen)
734{
735 struct object_directory *odb;
736
737 prepare_alt_odb(the_repository);
738 for (odb = the_repository->objects->odb->next; odb; odb = odb->next) {
739 if (check_and_freshen_odb(odb, oid, freshen))
740 return 1;
741 }
742 return 0;
743}
744
745static int check_and_freshen(const struct object_id *oid, int freshen)
746{
747 return check_and_freshen_local(oid, freshen) ||
748 check_and_freshen_nonlocal(oid, freshen);
749}
750
751int has_loose_object_nonlocal(const struct object_id *oid)
752{
753 return check_and_freshen_nonlocal(oid, 0);
754}
755
756static int has_loose_object(const struct object_id *oid)
757{
758 return check_and_freshen(oid, 0);
759}
760
761static void mmap_limit_check(size_t length)
762{
763 static size_t limit = 0;
764 if (!limit) {
765 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
766 if (!limit)
767 limit = SIZE_MAX;
768 }
769 if (length > limit)
770 die(_("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX),
771 (uintmax_t)length, (uintmax_t)limit);
772}
773
774void *xmmap_gently(void *start, size_t length,
775 int prot, int flags, int fd, off_t offset)
776{
777 void *ret;
778
779 mmap_limit_check(length);
780 ret = mmap(start, length, prot, flags, fd, offset);
781 if (ret == MAP_FAILED) {
782 if (!length)
783 return NULL;
784 release_pack_memory(length);
785 ret = mmap(start, length, prot, flags, fd, offset);
786 }
787 return ret;
788}
789
790void *xmmap(void *start, size_t length,
791 int prot, int flags, int fd, off_t offset)
792{
793 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
794 if (ret == MAP_FAILED)
795 die_errno(_("mmap failed"));
796 return ret;
797}
798
799/*
800 * With an in-core object data in "map", rehash it to make sure the
801 * object name actually matches "oid" to detect object corruption.
802 * With "map" == NULL, try reading the object named with "oid" using
803 * the streaming interface and rehash it to do the same.
804 */
805int check_object_signature(const struct object_id *oid, void *map,
806 unsigned long size, const char *type)
807{
808 struct object_id real_oid;
809 enum object_type obj_type;
810 struct git_istream *st;
811 git_hash_ctx c;
812 char hdr[MAX_HEADER_LEN];
813 int hdrlen;
814
815 if (map) {
816 hash_object_file(map, size, type, &real_oid);
817 return !oideq(oid, &real_oid) ? -1 : 0;
818 }
819
820 st = open_istream(oid, &obj_type, &size, NULL);
821 if (!st)
822 return -1;
823
824 /* Generate the header */
825 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(obj_type), (uintmax_t)size) + 1;
826
827 /* Sha1.. */
828 the_hash_algo->init_fn(&c);
829 the_hash_algo->update_fn(&c, hdr, hdrlen);
830 for (;;) {
831 char buf[1024 * 16];
832 ssize_t readlen = read_istream(st, buf, sizeof(buf));
833
834 if (readlen < 0) {
835 close_istream(st);
836 return -1;
837 }
838 if (!readlen)
839 break;
840 the_hash_algo->update_fn(&c, buf, readlen);
841 }
842 the_hash_algo->final_fn(real_oid.hash, &c);
843 close_istream(st);
844 return !oideq(oid, &real_oid) ? -1 : 0;
845}
846
847int git_open_cloexec(const char *name, int flags)
848{
849 int fd;
850 static int o_cloexec = O_CLOEXEC;
851
852 fd = open(name, flags | o_cloexec);
853 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
854 /* Try again w/o O_CLOEXEC: the kernel might not support it */
855 o_cloexec &= ~O_CLOEXEC;
856 fd = open(name, flags | o_cloexec);
857 }
858
859#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
860 {
861 static int fd_cloexec = FD_CLOEXEC;
862
863 if (!o_cloexec && 0 <= fd && fd_cloexec) {
864 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
865 int flags = fcntl(fd, F_GETFD);
866 if (fcntl(fd, F_SETFD, flags | fd_cloexec))
867 fd_cloexec = 0;
868 }
869 }
870#endif
871 return fd;
872}
873
874/*
875 * Find "oid" as a loose object in the local repository or in an alternate.
876 * Returns 0 on success, negative on failure.
877 *
878 * The "path" out-parameter will give the path of the object we found (if any).
879 * Note that it may point to static storage and is only valid until another
880 * call to stat_loose_object().
881 */
882static int stat_loose_object(struct repository *r, const struct object_id *oid,
883 struct stat *st, const char **path)
884{
885 struct object_directory *odb;
886 static struct strbuf buf = STRBUF_INIT;
887
888 prepare_alt_odb(r);
889 for (odb = r->objects->odb; odb; odb = odb->next) {
890 *path = odb_loose_path(odb, &buf, oid);
891 if (!lstat(*path, st))
892 return 0;
893 }
894
895 return -1;
896}
897
898/*
899 * Like stat_loose_object(), but actually open the object and return the
900 * descriptor. See the caveats on the "path" parameter above.
901 */
902static int open_loose_object(struct repository *r,
903 const struct object_id *oid, const char **path)
904{
905 int fd;
906 struct object_directory *odb;
907 int most_interesting_errno = ENOENT;
908 static struct strbuf buf = STRBUF_INIT;
909
910 prepare_alt_odb(r);
911 for (odb = r->objects->odb; odb; odb = odb->next) {
912 *path = odb_loose_path(odb, &buf, oid);
913 fd = git_open(*path);
914 if (fd >= 0)
915 return fd;
916
917 if (most_interesting_errno == ENOENT)
918 most_interesting_errno = errno;
919 }
920 errno = most_interesting_errno;
921 return -1;
922}
923
924static int quick_has_loose(struct repository *r,
925 const struct object_id *oid)
926{
927 struct object_directory *odb;
928
929 prepare_alt_odb(r);
930 for (odb = r->objects->odb; odb; odb = odb->next) {
931 if (oid_array_lookup(odb_loose_cache(odb, oid), oid) >= 0)
932 return 1;
933 }
934 return 0;
935}
936
937/*
938 * Map the loose object at "path" if it is not NULL, or the path found by
939 * searching for a loose object named "oid".
940 */
941static void *map_loose_object_1(struct repository *r, const char *path,
942 const struct object_id *oid, unsigned long *size)
943{
944 void *map;
945 int fd;
946
947 if (path)
948 fd = git_open(path);
949 else
950 fd = open_loose_object(r, oid, &path);
951 map = NULL;
952 if (fd >= 0) {
953 struct stat st;
954
955 if (!fstat(fd, &st)) {
956 *size = xsize_t(st.st_size);
957 if (!*size) {
958 /* mmap() is forbidden on empty files */
959 error(_("object file %s is empty"), path);
960 return NULL;
961 }
962 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
963 }
964 close(fd);
965 }
966 return map;
967}
968
969void *map_loose_object(struct repository *r,
970 const struct object_id *oid,
971 unsigned long *size)
972{
973 return map_loose_object_1(r, NULL, oid, size);
974}
975
976static int unpack_loose_short_header(git_zstream *stream,
977 unsigned char *map, unsigned long mapsize,
978 void *buffer, unsigned long bufsiz)
979{
980 /* Get the data stream */
981 memset(stream, 0, sizeof(*stream));
982 stream->next_in = map;
983 stream->avail_in = mapsize;
984 stream->next_out = buffer;
985 stream->avail_out = bufsiz;
986
987 git_inflate_init(stream);
988 return git_inflate(stream, 0);
989}
990
991int unpack_loose_header(git_zstream *stream,
992 unsigned char *map, unsigned long mapsize,
993 void *buffer, unsigned long bufsiz)
994{
995 int status = unpack_loose_short_header(stream, map, mapsize,
996 buffer, bufsiz);
997
998 if (status < Z_OK)
999 return status;
1000
1001 /* Make sure we have the terminating NUL */
1002 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1003 return -1;
1004 return 0;
1005}
1006
1007static int unpack_loose_header_to_strbuf(git_zstream *stream, unsigned char *map,
1008 unsigned long mapsize, void *buffer,
1009 unsigned long bufsiz, struct strbuf *header)
1010{
1011 int status;
1012
1013 status = unpack_loose_short_header(stream, map, mapsize, buffer, bufsiz);
1014 if (status < Z_OK)
1015 return -1;
1016
1017 /*
1018 * Check if entire header is unpacked in the first iteration.
1019 */
1020 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1021 return 0;
1022
1023 /*
1024 * buffer[0..bufsiz] was not large enough. Copy the partial
1025 * result out to header, and then append the result of further
1026 * reading the stream.
1027 */
1028 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1029 stream->next_out = buffer;
1030 stream->avail_out = bufsiz;
1031
1032 do {
1033 status = git_inflate(stream, 0);
1034 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1035 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1036 return 0;
1037 stream->next_out = buffer;
1038 stream->avail_out = bufsiz;
1039 } while (status != Z_STREAM_END);
1040 return -1;
1041}
1042
1043static void *unpack_loose_rest(git_zstream *stream,
1044 void *buffer, unsigned long size,
1045 const struct object_id *oid)
1046{
1047 int bytes = strlen(buffer) + 1;
1048 unsigned char *buf = xmallocz(size);
1049 unsigned long n;
1050 int status = Z_OK;
1051
1052 n = stream->total_out - bytes;
1053 if (n > size)
1054 n = size;
1055 memcpy(buf, (char *) buffer + bytes, n);
1056 bytes = n;
1057 if (bytes <= size) {
1058 /*
1059 * The above condition must be (bytes <= size), not
1060 * (bytes < size). In other words, even though we
1061 * expect no more output and set avail_out to zero,
1062 * the input zlib stream may have bytes that express
1063 * "this concludes the stream", and we *do* want to
1064 * eat that input.
1065 *
1066 * Otherwise we would not be able to test that we
1067 * consumed all the input to reach the expected size;
1068 * we also want to check that zlib tells us that all
1069 * went well with status == Z_STREAM_END at the end.
1070 */
1071 stream->next_out = buf + bytes;
1072 stream->avail_out = size - bytes;
1073 while (status == Z_OK)
1074 status = git_inflate(stream, Z_FINISH);
1075 }
1076 if (status == Z_STREAM_END && !stream->avail_in) {
1077 git_inflate_end(stream);
1078 return buf;
1079 }
1080
1081 if (status < 0)
1082 error(_("corrupt loose object '%s'"), oid_to_hex(oid));
1083 else if (stream->avail_in)
1084 error(_("garbage at end of loose object '%s'"),
1085 oid_to_hex(oid));
1086 free(buf);
1087 return NULL;
1088}
1089
1090/*
1091 * We used to just use "sscanf()", but that's actually way
1092 * too permissive for what we want to check. So do an anal
1093 * object header parse by hand.
1094 */
1095static int parse_loose_header_extended(const char *hdr, struct object_info *oi,
1096 unsigned int flags)
1097{
1098 const char *type_buf = hdr;
1099 unsigned long size;
1100 int type, type_len = 0;
1101
1102 /*
1103 * The type can be of any size but is followed by
1104 * a space.
1105 */
1106 for (;;) {
1107 char c = *hdr++;
1108 if (!c)
1109 return -1;
1110 if (c == ' ')
1111 break;
1112 type_len++;
1113 }
1114
1115 type = type_from_string_gently(type_buf, type_len, 1);
1116 if (oi->type_name)
1117 strbuf_add(oi->type_name, type_buf, type_len);
1118 /*
1119 * Set type to 0 if its an unknown object and
1120 * we're obtaining the type using '--allow-unknown-type'
1121 * option.
1122 */
1123 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
1124 type = 0;
1125 else if (type < 0)
1126 die(_("invalid object type"));
1127 if (oi->typep)
1128 *oi->typep = type;
1129
1130 /*
1131 * The length must follow immediately, and be in canonical
1132 * decimal format (ie "010" is not valid).
1133 */
1134 size = *hdr++ - '0';
1135 if (size > 9)
1136 return -1;
1137 if (size) {
1138 for (;;) {
1139 unsigned long c = *hdr - '0';
1140 if (c > 9)
1141 break;
1142 hdr++;
1143 size = size * 10 + c;
1144 }
1145 }
1146
1147 if (oi->sizep)
1148 *oi->sizep = size;
1149
1150 /*
1151 * The length must be followed by a zero byte
1152 */
1153 return *hdr ? -1 : type;
1154}
1155
1156int parse_loose_header(const char *hdr, unsigned long *sizep)
1157{
1158 struct object_info oi = OBJECT_INFO_INIT;
1159
1160 oi.sizep = sizep;
1161 return parse_loose_header_extended(hdr, &oi, 0);
1162}
1163
1164static int loose_object_info(struct repository *r,
1165 const struct object_id *oid,
1166 struct object_info *oi, int flags)
1167{
1168 int status = 0;
1169 unsigned long mapsize;
1170 void *map;
1171 git_zstream stream;
1172 char hdr[MAX_HEADER_LEN];
1173 struct strbuf hdrbuf = STRBUF_INIT;
1174 unsigned long size_scratch;
1175
1176 if (oi->delta_base_sha1)
1177 hashclr(oi->delta_base_sha1);
1178
1179 /*
1180 * If we don't care about type or size, then we don't
1181 * need to look inside the object at all. Note that we
1182 * do not optimize out the stat call, even if the
1183 * caller doesn't care about the disk-size, since our
1184 * return value implicitly indicates whether the
1185 * object even exists.
1186 */
1187 if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
1188 const char *path;
1189 struct stat st;
1190 if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
1191 return quick_has_loose(r, oid) ? 0 : -1;
1192 if (stat_loose_object(r, oid, &st, &path) < 0)
1193 return -1;
1194 if (oi->disk_sizep)
1195 *oi->disk_sizep = st.st_size;
1196 return 0;
1197 }
1198
1199 map = map_loose_object(r, oid, &mapsize);
1200 if (!map)
1201 return -1;
1202
1203 if (!oi->sizep)
1204 oi->sizep = &size_scratch;
1205
1206 if (oi->disk_sizep)
1207 *oi->disk_sizep = mapsize;
1208 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
1209 if (unpack_loose_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
1210 status = error(_("unable to unpack %s header with --allow-unknown-type"),
1211 oid_to_hex(oid));
1212 } else if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1213 status = error(_("unable to unpack %s header"),
1214 oid_to_hex(oid));
1215 if (status < 0)
1216 ; /* Do nothing */
1217 else if (hdrbuf.len) {
1218 if ((status = parse_loose_header_extended(hdrbuf.buf, oi, flags)) < 0)
1219 status = error(_("unable to parse %s header with --allow-unknown-type"),
1220 oid_to_hex(oid));
1221 } else if ((status = parse_loose_header_extended(hdr, oi, flags)) < 0)
1222 status = error(_("unable to parse %s header"), oid_to_hex(oid));
1223
1224 if (status >= 0 && oi->contentp) {
1225 *oi->contentp = unpack_loose_rest(&stream, hdr,
1226 *oi->sizep, oid);
1227 if (!*oi->contentp) {
1228 git_inflate_end(&stream);
1229 status = -1;
1230 }
1231 } else
1232 git_inflate_end(&stream);
1233
1234 munmap(map, mapsize);
1235 if (status && oi->typep)
1236 *oi->typep = status;
1237 if (oi->sizep == &size_scratch)
1238 oi->sizep = NULL;
1239 strbuf_release(&hdrbuf);
1240 oi->whence = OI_LOOSE;
1241 return (status < 0) ? status : 0;
1242}
1243
1244int fetch_if_missing = 1;
1245
1246int oid_object_info_extended(struct repository *r, const struct object_id *oid,
1247 struct object_info *oi, unsigned flags)
1248{
1249 static struct object_info blank_oi = OBJECT_INFO_INIT;
1250 struct pack_entry e;
1251 int rtype;
1252 const struct object_id *real = oid;
1253 int already_retried = 0;
1254
1255 if (flags & OBJECT_INFO_LOOKUP_REPLACE)
1256 real = lookup_replace_object(r, oid);
1257
1258 if (is_null_oid(real))
1259 return -1;
1260
1261 if (!oi)
1262 oi = &blank_oi;
1263
1264 if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
1265 struct cached_object *co = find_cached_object(real);
1266 if (co) {
1267 if (oi->typep)
1268 *(oi->typep) = co->type;
1269 if (oi->sizep)
1270 *(oi->sizep) = co->size;
1271 if (oi->disk_sizep)
1272 *(oi->disk_sizep) = 0;
1273 if (oi->delta_base_sha1)
1274 hashclr(oi->delta_base_sha1);
1275 if (oi->type_name)
1276 strbuf_addstr(oi->type_name, type_name(co->type));
1277 if (oi->contentp)
1278 *oi->contentp = xmemdupz(co->buf, co->size);
1279 oi->whence = OI_CACHED;
1280 return 0;
1281 }
1282 }
1283
1284 while (1) {
1285 if (find_pack_entry(r, real, &e))
1286 break;
1287
1288 if (flags & OBJECT_INFO_IGNORE_LOOSE)
1289 return -1;
1290
1291 /* Most likely it's a loose object. */
1292 if (!loose_object_info(r, real, oi, flags))
1293 return 0;
1294
1295 /* Not a loose object; someone else may have just packed it. */
1296 if (!(flags & OBJECT_INFO_QUICK)) {
1297 reprepare_packed_git(r);
1298 if (find_pack_entry(r, real, &e))
1299 break;
1300 }
1301
1302 /* Check if it is a missing object */
1303 if (fetch_if_missing && repository_format_partial_clone &&
1304 !already_retried && r == the_repository) {
1305 /*
1306 * TODO Investigate having fetch_object() return
1307 * TODO error/success and stopping the music here.
1308 * TODO Pass a repository struct through fetch_object,
1309 * such that arbitrary repositories work.
1310 */
1311 fetch_objects(repository_format_partial_clone, real, 1);
1312 already_retried = 1;
1313 continue;
1314 }
1315
1316 return -1;
1317 }
1318
1319 if (oi == &blank_oi)
1320 /*
1321 * We know that the caller doesn't actually need the
1322 * information below, so return early.
1323 */
1324 return 0;
1325 rtype = packed_object_info(r, e.p, e.offset, oi);
1326 if (rtype < 0) {
1327 mark_bad_packed_object(e.p, real->hash);
1328 return oid_object_info_extended(r, real, oi, 0);
1329 } else if (oi->whence == OI_PACKED) {
1330 oi->u.packed.offset = e.offset;
1331 oi->u.packed.pack = e.p;
1332 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
1333 rtype == OBJ_OFS_DELTA);
1334 }
1335
1336 return 0;
1337}
1338
1339/* returns enum object_type or negative */
1340int oid_object_info(struct repository *r,
1341 const struct object_id *oid,
1342 unsigned long *sizep)
1343{
1344 enum object_type type;
1345 struct object_info oi = OBJECT_INFO_INIT;
1346
1347 oi.typep = &type;
1348 oi.sizep = sizep;
1349 if (oid_object_info_extended(r, oid, &oi,
1350 OBJECT_INFO_LOOKUP_REPLACE) < 0)
1351 return -1;
1352 return type;
1353}
1354
1355static void *read_object(const struct object_id *oid, enum object_type *type,
1356 unsigned long *size)
1357{
1358 struct object_info oi = OBJECT_INFO_INIT;
1359 void *content;
1360 oi.typep = type;
1361 oi.sizep = size;
1362 oi.contentp = &content;
1363
1364 if (oid_object_info_extended(the_repository, oid, &oi, 0) < 0)
1365 return NULL;
1366 return content;
1367}
1368
1369int pretend_object_file(void *buf, unsigned long len, enum object_type type,
1370 struct object_id *oid)
1371{
1372 struct cached_object *co;
1373
1374 hash_object_file(buf, len, type_name(type), oid);
1375 if (has_object_file(oid) || find_cached_object(oid))
1376 return 0;
1377 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
1378 co = &cached_objects[cached_object_nr++];
1379 co->size = len;
1380 co->type = type;
1381 co->buf = xmalloc(len);
1382 memcpy(co->buf, buf, len);
1383 oidcpy(&co->oid, oid);
1384 return 0;
1385}
1386
1387/*
1388 * This function dies on corrupt objects; the callers who want to
1389 * deal with them should arrange to call read_object() and give error
1390 * messages themselves.
1391 */
1392void *read_object_file_extended(const struct object_id *oid,
1393 enum object_type *type,
1394 unsigned long *size,
1395 int lookup_replace)
1396{
1397 void *data;
1398 const struct packed_git *p;
1399 const char *path;
1400 struct stat st;
1401 const struct object_id *repl = lookup_replace ?
1402 lookup_replace_object(the_repository, oid) : oid;
1403
1404 errno = 0;
1405 data = read_object(repl, type, size);
1406 if (data)
1407 return data;
1408
1409 if (errno && errno != ENOENT)
1410 die_errno(_("failed to read object %s"), oid_to_hex(oid));
1411
1412 /* die if we replaced an object with one that does not exist */
1413 if (repl != oid)
1414 die(_("replacement %s not found for %s"),
1415 oid_to_hex(repl), oid_to_hex(oid));
1416
1417 if (!stat_loose_object(the_repository, repl, &st, &path))
1418 die(_("loose object %s (stored in %s) is corrupt"),
1419 oid_to_hex(repl), path);
1420
1421 if ((p = has_packed_and_bad(repl->hash)) != NULL)
1422 die(_("packed object %s (stored in %s) is corrupt"),
1423 oid_to_hex(repl), p->pack_name);
1424
1425 return NULL;
1426}
1427
1428void *read_object_with_reference(const struct object_id *oid,
1429 const char *required_type_name,
1430 unsigned long *size,
1431 struct object_id *actual_oid_return)
1432{
1433 enum object_type type, required_type;
1434 void *buffer;
1435 unsigned long isize;
1436 struct object_id actual_oid;
1437
1438 required_type = type_from_string(required_type_name);
1439 oidcpy(&actual_oid, oid);
1440 while (1) {
1441 int ref_length = -1;
1442 const char *ref_type = NULL;
1443
1444 buffer = read_object_file(&actual_oid, &type, &isize);
1445 if (!buffer)
1446 return NULL;
1447 if (type == required_type) {
1448 *size = isize;
1449 if (actual_oid_return)
1450 oidcpy(actual_oid_return, &actual_oid);
1451 return buffer;
1452 }
1453 /* Handle references */
1454 else if (type == OBJ_COMMIT)
1455 ref_type = "tree ";
1456 else if (type == OBJ_TAG)
1457 ref_type = "object ";
1458 else {
1459 free(buffer);
1460 return NULL;
1461 }
1462 ref_length = strlen(ref_type);
1463
1464 if (ref_length + the_hash_algo->hexsz > isize ||
1465 memcmp(buffer, ref_type, ref_length) ||
1466 get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
1467 free(buffer);
1468 return NULL;
1469 }
1470 free(buffer);
1471 /* Now we have the ID of the referred-to object in
1472 * actual_oid. Check again. */
1473 }
1474}
1475
1476static void write_object_file_prepare(const void *buf, unsigned long len,
1477 const char *type, struct object_id *oid,
1478 char *hdr, int *hdrlen)
1479{
1480 git_hash_ctx c;
1481
1482 /* Generate the header */
1483 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %"PRIuMAX , type, (uintmax_t)len)+1;
1484
1485 /* Sha1.. */
1486 the_hash_algo->init_fn(&c);
1487 the_hash_algo->update_fn(&c, hdr, *hdrlen);
1488 the_hash_algo->update_fn(&c, buf, len);
1489 the_hash_algo->final_fn(oid->hash, &c);
1490}
1491
1492/*
1493 * Move the just written object into its final resting place.
1494 */
1495int finalize_object_file(const char *tmpfile, const char *filename)
1496{
1497 int ret = 0;
1498
1499 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
1500 goto try_rename;
1501 else if (link(tmpfile, filename))
1502 ret = errno;
1503
1504 /*
1505 * Coda hack - coda doesn't like cross-directory links,
1506 * so we fall back to a rename, which will mean that it
1507 * won't be able to check collisions, but that's not a
1508 * big deal.
1509 *
1510 * The same holds for FAT formatted media.
1511 *
1512 * When this succeeds, we just return. We have nothing
1513 * left to unlink.
1514 */
1515 if (ret && ret != EEXIST) {
1516 try_rename:
1517 if (!rename(tmpfile, filename))
1518 goto out;
1519 ret = errno;
1520 }
1521 unlink_or_warn(tmpfile);
1522 if (ret) {
1523 if (ret != EEXIST) {
1524 return error_errno(_("unable to write sha1 filename %s"), filename);
1525 }
1526 /* FIXME!!! Collision check here ? */
1527 }
1528
1529out:
1530 if (adjust_shared_perm(filename))
1531 return error(_("unable to set permission to '%s'"), filename);
1532 return 0;
1533}
1534
1535static int write_buffer(int fd, const void *buf, size_t len)
1536{
1537 if (write_in_full(fd, buf, len) < 0)
1538 return error_errno(_("file write error"));
1539 return 0;
1540}
1541
1542int hash_object_file(const void *buf, unsigned long len, const char *type,
1543 struct object_id *oid)
1544{
1545 char hdr[MAX_HEADER_LEN];
1546 int hdrlen = sizeof(hdr);
1547 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1548 return 0;
1549}
1550
1551/* Finalize a file on disk, and close it. */
1552static void close_loose_object(int fd)
1553{
1554 if (fsync_object_files)
1555 fsync_or_die(fd, "loose object file");
1556 if (close(fd) != 0)
1557 die_errno(_("error when closing loose object file"));
1558}
1559
1560/* Size of directory component, including the ending '/' */
1561static inline int directory_size(const char *filename)
1562{
1563 const char *s = strrchr(filename, '/');
1564 if (!s)
1565 return 0;
1566 return s - filename + 1;
1567}
1568
1569/*
1570 * This creates a temporary file in the same directory as the final
1571 * 'filename'
1572 *
1573 * We want to avoid cross-directory filename renames, because those
1574 * can have problems on various filesystems (FAT, NFS, Coda).
1575 */
1576static int create_tmpfile(struct strbuf *tmp, const char *filename)
1577{
1578 int fd, dirlen = directory_size(filename);
1579
1580 strbuf_reset(tmp);
1581 strbuf_add(tmp, filename, dirlen);
1582 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
1583 fd = git_mkstemp_mode(tmp->buf, 0444);
1584 if (fd < 0 && dirlen && errno == ENOENT) {
1585 /*
1586 * Make sure the directory exists; note that the contents
1587 * of the buffer are undefined after mkstemp returns an
1588 * error, so we have to rewrite the whole buffer from
1589 * scratch.
1590 */
1591 strbuf_reset(tmp);
1592 strbuf_add(tmp, filename, dirlen - 1);
1593 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
1594 return -1;
1595 if (adjust_shared_perm(tmp->buf))
1596 return -1;
1597
1598 /* Try again */
1599 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
1600 fd = git_mkstemp_mode(tmp->buf, 0444);
1601 }
1602 return fd;
1603}
1604
1605static int write_loose_object(const struct object_id *oid, char *hdr,
1606 int hdrlen, const void *buf, unsigned long len,
1607 time_t mtime)
1608{
1609 int fd, ret;
1610 unsigned char compressed[4096];
1611 git_zstream stream;
1612 git_hash_ctx c;
1613 struct object_id parano_oid;
1614 static struct strbuf tmp_file = STRBUF_INIT;
1615 static struct strbuf filename = STRBUF_INIT;
1616
1617 loose_object_path(the_repository, &filename, oid);
1618
1619 fd = create_tmpfile(&tmp_file, filename.buf);
1620 if (fd < 0) {
1621 if (errno == EACCES)
1622 return error(_("insufficient permission for adding an object to repository database %s"), get_object_directory());
1623 else
1624 return error_errno(_("unable to create temporary file"));
1625 }
1626
1627 /* Set it up */
1628 git_deflate_init(&stream, zlib_compression_level);
1629 stream.next_out = compressed;
1630 stream.avail_out = sizeof(compressed);
1631 the_hash_algo->init_fn(&c);
1632
1633 /* First header.. */
1634 stream.next_in = (unsigned char *)hdr;
1635 stream.avail_in = hdrlen;
1636 while (git_deflate(&stream, 0) == Z_OK)
1637 ; /* nothing */
1638 the_hash_algo->update_fn(&c, hdr, hdrlen);
1639
1640 /* Then the data itself.. */
1641 stream.next_in = (void *)buf;
1642 stream.avail_in = len;
1643 do {
1644 unsigned char *in0 = stream.next_in;
1645 ret = git_deflate(&stream, Z_FINISH);
1646 the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
1647 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
1648 die(_("unable to write loose object file"));
1649 stream.next_out = compressed;
1650 stream.avail_out = sizeof(compressed);
1651 } while (ret == Z_OK);
1652
1653 if (ret != Z_STREAM_END)
1654 die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
1655 ret);
1656 ret = git_deflate_end_gently(&stream);
1657 if (ret != Z_OK)
1658 die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
1659 ret);
1660 the_hash_algo->final_fn(parano_oid.hash, &c);
1661 if (!oideq(oid, ¶no_oid))
1662 die(_("confused by unstable object source data for %s"),
1663 oid_to_hex(oid));
1664
1665 close_loose_object(fd);
1666
1667 if (mtime) {
1668 struct utimbuf utb;
1669 utb.actime = mtime;
1670 utb.modtime = mtime;
1671 if (utime(tmp_file.buf, &utb) < 0)
1672 warning_errno(_("failed utime() on %s"), tmp_file.buf);
1673 }
1674
1675 return finalize_object_file(tmp_file.buf, filename.buf);
1676}
1677
1678static int freshen_loose_object(const struct object_id *oid)
1679{
1680 return check_and_freshen(oid, 1);
1681}
1682
1683static int freshen_packed_object(const struct object_id *oid)
1684{
1685 struct pack_entry e;
1686 if (!find_pack_entry(the_repository, oid, &e))
1687 return 0;
1688 if (e.p->freshened)
1689 return 1;
1690 if (!freshen_file(e.p->pack_name))
1691 return 0;
1692 e.p->freshened = 1;
1693 return 1;
1694}
1695
1696int write_object_file(const void *buf, unsigned long len, const char *type,
1697 struct object_id *oid)
1698{
1699 char hdr[MAX_HEADER_LEN];
1700 int hdrlen = sizeof(hdr);
1701
1702 /* Normally if we have it in the pack then we do not bother writing
1703 * it out into .git/objects/??/?{38} file.
1704 */
1705 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1706 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1707 return 0;
1708 return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
1709}
1710
1711int hash_object_file_literally(const void *buf, unsigned long len,
1712 const char *type, struct object_id *oid,
1713 unsigned flags)
1714{
1715 char *header;
1716 int hdrlen, status = 0;
1717
1718 /* type string, SP, %lu of the length plus NUL must fit this */
1719 hdrlen = strlen(type) + MAX_HEADER_LEN;
1720 header = xmalloc(hdrlen);
1721 write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
1722
1723 if (!(flags & HASH_WRITE_OBJECT))
1724 goto cleanup;
1725 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1726 goto cleanup;
1727 status = write_loose_object(oid, header, hdrlen, buf, len, 0);
1728
1729cleanup:
1730 free(header);
1731 return status;
1732}
1733
1734int force_object_loose(const struct object_id *oid, time_t mtime)
1735{
1736 void *buf;
1737 unsigned long len;
1738 enum object_type type;
1739 char hdr[MAX_HEADER_LEN];
1740 int hdrlen;
1741 int ret;
1742
1743 if (has_loose_object(oid))
1744 return 0;
1745 buf = read_object(oid, &type, &len);
1746 if (!buf)
1747 return error(_("cannot read sha1_file for %s"), oid_to_hex(oid));
1748 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %"PRIuMAX , type_name(type), (uintmax_t)len) + 1;
1749 ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
1750 free(buf);
1751
1752 return ret;
1753}
1754
1755int has_object_file_with_flags(const struct object_id *oid, int flags)
1756{
1757 if (!startup_info->have_repository)
1758 return 0;
1759 return oid_object_info_extended(the_repository, oid, NULL,
1760 flags | OBJECT_INFO_SKIP_CACHED) >= 0;
1761}
1762
1763static void check_tree(const void *buf, size_t size)
1764{
1765 struct tree_desc desc;
1766 struct name_entry entry;
1767
1768 init_tree_desc(&desc, buf, size);
1769 while (tree_entry(&desc, &entry))
1770 /* do nothing
1771 * tree_entry() will die() on malformed entries */
1772 ;
1773}
1774
1775static void check_commit(const void *buf, size_t size)
1776{
1777 struct commit c;
1778 memset(&c, 0, sizeof(c));
1779 if (parse_commit_buffer(the_repository, &c, buf, size, 0))
1780 die(_("corrupt commit"));
1781}
1782
1783static void check_tag(const void *buf, size_t size)
1784{
1785 struct tag t;
1786 memset(&t, 0, sizeof(t));
1787 if (parse_tag_buffer(the_repository, &t, buf, size))
1788 die(_("corrupt tag"));
1789}
1790
1791static int index_mem(struct index_state *istate,
1792 struct object_id *oid, void *buf, size_t size,
1793 enum object_type type,
1794 const char *path, unsigned flags)
1795{
1796 int ret, re_allocated = 0;
1797 int write_object = flags & HASH_WRITE_OBJECT;
1798
1799 if (!type)
1800 type = OBJ_BLOB;
1801
1802 /*
1803 * Convert blobs to git internal format
1804 */
1805 if ((type == OBJ_BLOB) && path) {
1806 struct strbuf nbuf = STRBUF_INIT;
1807 if (convert_to_git(istate, path, buf, size, &nbuf,
1808 get_conv_flags(flags))) {
1809 buf = strbuf_detach(&nbuf, &size);
1810 re_allocated = 1;
1811 }
1812 }
1813 if (flags & HASH_FORMAT_CHECK) {
1814 if (type == OBJ_TREE)
1815 check_tree(buf, size);
1816 if (type == OBJ_COMMIT)
1817 check_commit(buf, size);
1818 if (type == OBJ_TAG)
1819 check_tag(buf, size);
1820 }
1821
1822 if (write_object)
1823 ret = write_object_file(buf, size, type_name(type), oid);
1824 else
1825 ret = hash_object_file(buf, size, type_name(type), oid);
1826 if (re_allocated)
1827 free(buf);
1828 return ret;
1829}
1830
1831static int index_stream_convert_blob(struct index_state *istate,
1832 struct object_id *oid,
1833 int fd,
1834 const char *path,
1835 unsigned flags)
1836{
1837 int ret;
1838 const int write_object = flags & HASH_WRITE_OBJECT;
1839 struct strbuf sbuf = STRBUF_INIT;
1840
1841 assert(path);
1842 assert(would_convert_to_git_filter_fd(istate, path));
1843
1844 convert_to_git_filter_fd(istate, path, fd, &sbuf,
1845 get_conv_flags(flags));
1846
1847 if (write_object)
1848 ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1849 oid);
1850 else
1851 ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1852 oid);
1853 strbuf_release(&sbuf);
1854 return ret;
1855}
1856
1857static int index_pipe(struct index_state *istate, struct object_id *oid,
1858 int fd, enum object_type type,
1859 const char *path, unsigned flags)
1860{
1861 struct strbuf sbuf = STRBUF_INIT;
1862 int ret;
1863
1864 if (strbuf_read(&sbuf, fd, 4096) >= 0)
1865 ret = index_mem(istate, oid, sbuf.buf, sbuf.len, type, path, flags);
1866 else
1867 ret = -1;
1868 strbuf_release(&sbuf);
1869 return ret;
1870}
1871
1872#define SMALL_FILE_SIZE (32*1024)
1873
1874static int index_core(struct index_state *istate,
1875 struct object_id *oid, int fd, size_t size,
1876 enum object_type type, const char *path,
1877 unsigned flags)
1878{
1879 int ret;
1880
1881 if (!size) {
1882 ret = index_mem(istate, oid, "", size, type, path, flags);
1883 } else if (size <= SMALL_FILE_SIZE) {
1884 char *buf = xmalloc(size);
1885 ssize_t read_result = read_in_full(fd, buf, size);
1886 if (read_result < 0)
1887 ret = error_errno(_("read error while indexing %s"),
1888 path ? path : "<unknown>");
1889 else if (read_result != size)
1890 ret = error(_("short read while indexing %s"),
1891 path ? path : "<unknown>");
1892 else
1893 ret = index_mem(istate, oid, buf, size, type, path, flags);
1894 free(buf);
1895 } else {
1896 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1897 ret = index_mem(istate, oid, buf, size, type, path, flags);
1898 munmap(buf, size);
1899 }
1900 return ret;
1901}
1902
1903/*
1904 * This creates one packfile per large blob unless bulk-checkin
1905 * machinery is "plugged".
1906 *
1907 * This also bypasses the usual "convert-to-git" dance, and that is on
1908 * purpose. We could write a streaming version of the converting
1909 * functions and insert that before feeding the data to fast-import
1910 * (or equivalent in-core API described above). However, that is
1911 * somewhat complicated, as we do not know the size of the filter
1912 * result, which we need to know beforehand when writing a git object.
1913 * Since the primary motivation for trying to stream from the working
1914 * tree file and to avoid mmaping it in core is to deal with large
1915 * binary blobs, they generally do not want to get any conversion, and
1916 * callers should avoid this code path when filters are requested.
1917 */
1918static int index_stream(struct object_id *oid, int fd, size_t size,
1919 enum object_type type, const char *path,
1920 unsigned flags)
1921{
1922 return index_bulk_checkin(oid, fd, size, type, path, flags);
1923}
1924
1925int index_fd(struct index_state *istate, struct object_id *oid,
1926 int fd, struct stat *st,
1927 enum object_type type, const char *path, unsigned flags)
1928{
1929 int ret;
1930
1931 /*
1932 * Call xsize_t() only when needed to avoid potentially unnecessary
1933 * die() for large files.
1934 */
1935 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
1936 ret = index_stream_convert_blob(istate, oid, fd, path, flags);
1937 else if (!S_ISREG(st->st_mode))
1938 ret = index_pipe(istate, oid, fd, type, path, flags);
1939 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
1940 (path && would_convert_to_git(istate, path)))
1941 ret = index_core(istate, oid, fd, xsize_t(st->st_size),
1942 type, path, flags);
1943 else
1944 ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
1945 flags);
1946 close(fd);
1947 return ret;
1948}
1949
1950int index_path(struct index_state *istate, struct object_id *oid,
1951 const char *path, struct stat *st, unsigned flags)
1952{
1953 int fd;
1954 struct strbuf sb = STRBUF_INIT;
1955 int rc = 0;
1956
1957 switch (st->st_mode & S_IFMT) {
1958 case S_IFREG:
1959 fd = open(path, O_RDONLY);
1960 if (fd < 0)
1961 return error_errno("open(\"%s\")", path);
1962 if (index_fd(istate, oid, fd, st, OBJ_BLOB, path, flags) < 0)
1963 return error(_("%s: failed to insert into database"),
1964 path);
1965 break;
1966 case S_IFLNK:
1967 if (strbuf_readlink(&sb, path, st->st_size))
1968 return error_errno("readlink(\"%s\")", path);
1969 if (!(flags & HASH_WRITE_OBJECT))
1970 hash_object_file(sb.buf, sb.len, blob_type, oid);
1971 else if (write_object_file(sb.buf, sb.len, blob_type, oid))
1972 rc = error(_("%s: failed to insert into database"), path);
1973 strbuf_release(&sb);
1974 break;
1975 case S_IFDIR:
1976 return resolve_gitlink_ref(path, "HEAD", oid);
1977 default:
1978 return error(_("%s: unsupported file type"), path);
1979 }
1980 return rc;
1981}
1982
1983int read_pack_header(int fd, struct pack_header *header)
1984{
1985 if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
1986 /* "eof before pack header was fully read" */
1987 return PH_ERROR_EOF;
1988
1989 if (header->hdr_signature != htonl(PACK_SIGNATURE))
1990 /* "protocol error (pack signature mismatch detected)" */
1991 return PH_ERROR_PACK_SIGNATURE;
1992 if (!pack_version_ok(header->hdr_version))
1993 /* "protocol error (pack version unsupported)" */
1994 return PH_ERROR_PROTOCOL;
1995 return 0;
1996}
1997
1998void assert_oid_type(const struct object_id *oid, enum object_type expect)
1999{
2000 enum object_type type = oid_object_info(the_repository, oid, NULL);
2001 if (type < 0)
2002 die(_("%s is not a valid object"), oid_to_hex(oid));
2003 if (type != expect)
2004 die(_("%s is not a valid '%s' object"), oid_to_hex(oid),
2005 type_name(expect));
2006}
2007
2008int for_each_file_in_obj_subdir(unsigned int subdir_nr,
2009 struct strbuf *path,
2010 each_loose_object_fn obj_cb,
2011 each_loose_cruft_fn cruft_cb,
2012 each_loose_subdir_fn subdir_cb,
2013 void *data)
2014{
2015 size_t origlen, baselen;
2016 DIR *dir;
2017 struct dirent *de;
2018 int r = 0;
2019 struct object_id oid;
2020
2021 if (subdir_nr > 0xff)
2022 BUG("invalid loose object subdirectory: %x", subdir_nr);
2023
2024 origlen = path->len;
2025 strbuf_complete(path, '/');
2026 strbuf_addf(path, "%02x", subdir_nr);
2027
2028 dir = opendir(path->buf);
2029 if (!dir) {
2030 if (errno != ENOENT)
2031 r = error_errno(_("unable to open %s"), path->buf);
2032 strbuf_setlen(path, origlen);
2033 return r;
2034 }
2035
2036 oid.hash[0] = subdir_nr;
2037 strbuf_addch(path, '/');
2038 baselen = path->len;
2039
2040 while ((de = readdir(dir))) {
2041 size_t namelen;
2042 if (is_dot_or_dotdot(de->d_name))
2043 continue;
2044
2045 namelen = strlen(de->d_name);
2046 strbuf_setlen(path, baselen);
2047 strbuf_add(path, de->d_name, namelen);
2048 if (namelen == the_hash_algo->hexsz - 2 &&
2049 !hex_to_bytes(oid.hash + 1, de->d_name,
2050 the_hash_algo->rawsz - 1)) {
2051 if (obj_cb) {
2052 r = obj_cb(&oid, path->buf, data);
2053 if (r)
2054 break;
2055 }
2056 continue;
2057 }
2058
2059 if (cruft_cb) {
2060 r = cruft_cb(de->d_name, path->buf, data);
2061 if (r)
2062 break;
2063 }
2064 }
2065 closedir(dir);
2066
2067 strbuf_setlen(path, baselen - 1);
2068 if (!r && subdir_cb)
2069 r = subdir_cb(subdir_nr, path->buf, data);
2070
2071 strbuf_setlen(path, origlen);
2072
2073 return r;
2074}
2075
2076int for_each_loose_file_in_objdir_buf(struct strbuf *path,
2077 each_loose_object_fn obj_cb,
2078 each_loose_cruft_fn cruft_cb,
2079 each_loose_subdir_fn subdir_cb,
2080 void *data)
2081{
2082 int r = 0;
2083 int i;
2084
2085 for (i = 0; i < 256; i++) {
2086 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
2087 subdir_cb, data);
2088 if (r)
2089 break;
2090 }
2091
2092 return r;
2093}
2094
2095int for_each_loose_file_in_objdir(const char *path,
2096 each_loose_object_fn obj_cb,
2097 each_loose_cruft_fn cruft_cb,
2098 each_loose_subdir_fn subdir_cb,
2099 void *data)
2100{
2101 struct strbuf buf = STRBUF_INIT;
2102 int r;
2103
2104 strbuf_addstr(&buf, path);
2105 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
2106 subdir_cb, data);
2107 strbuf_release(&buf);
2108
2109 return r;
2110}
2111
2112int for_each_loose_object(each_loose_object_fn cb, void *data,
2113 enum for_each_object_flags flags)
2114{
2115 struct object_directory *odb;
2116
2117 prepare_alt_odb(the_repository);
2118 for (odb = the_repository->objects->odb; odb; odb = odb->next) {
2119 int r = for_each_loose_file_in_objdir(odb->path, cb, NULL,
2120 NULL, data);
2121 if (r)
2122 return r;
2123
2124 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
2125 break;
2126 }
2127
2128 return 0;
2129}
2130
2131static int append_loose_object(const struct object_id *oid, const char *path,
2132 void *data)
2133{
2134 oid_array_append(data, oid);
2135 return 0;
2136}
2137
2138struct oid_array *odb_loose_cache(struct object_directory *odb,
2139 const struct object_id *oid)
2140{
2141 int subdir_nr = oid->hash[0];
2142 struct strbuf buf = STRBUF_INIT;
2143
2144 if (subdir_nr < 0 ||
2145 subdir_nr >= ARRAY_SIZE(odb->loose_objects_subdir_seen))
2146 BUG("subdir_nr out of range");
2147
2148 if (odb->loose_objects_subdir_seen[subdir_nr])
2149 return &odb->loose_objects_cache[subdir_nr];
2150
2151 strbuf_addstr(&buf, odb->path);
2152 for_each_file_in_obj_subdir(subdir_nr, &buf,
2153 append_loose_object,
2154 NULL, NULL,
2155 &odb->loose_objects_cache[subdir_nr]);
2156 odb->loose_objects_subdir_seen[subdir_nr] = 1;
2157 strbuf_release(&buf);
2158 return &odb->loose_objects_cache[subdir_nr];
2159}
2160
2161void odb_clear_loose_cache(struct object_directory *odb)
2162{
2163 int i;
2164
2165 for (i = 0; i < ARRAY_SIZE(odb->loose_objects_cache); i++)
2166 oid_array_clear(&odb->loose_objects_cache[i]);
2167 memset(&odb->loose_objects_subdir_seen, 0,
2168 sizeof(odb->loose_objects_subdir_seen));
2169}
2170
2171static int check_stream_oid(git_zstream *stream,
2172 const char *hdr,
2173 unsigned long size,
2174 const char *path,
2175 const struct object_id *expected_oid)
2176{
2177 git_hash_ctx c;
2178 struct object_id real_oid;
2179 unsigned char buf[4096];
2180 unsigned long total_read;
2181 int status = Z_OK;
2182
2183 the_hash_algo->init_fn(&c);
2184 the_hash_algo->update_fn(&c, hdr, stream->total_out);
2185
2186 /*
2187 * We already read some bytes into hdr, but the ones up to the NUL
2188 * do not count against the object's content size.
2189 */
2190 total_read = stream->total_out - strlen(hdr) - 1;
2191
2192 /*
2193 * This size comparison must be "<=" to read the final zlib packets;
2194 * see the comment in unpack_loose_rest for details.
2195 */
2196 while (total_read <= size &&
2197 (status == Z_OK ||
2198 (status == Z_BUF_ERROR && !stream->avail_out))) {
2199 stream->next_out = buf;
2200 stream->avail_out = sizeof(buf);
2201 if (size - total_read < stream->avail_out)
2202 stream->avail_out = size - total_read;
2203 status = git_inflate(stream, Z_FINISH);
2204 the_hash_algo->update_fn(&c, buf, stream->next_out - buf);
2205 total_read += stream->next_out - buf;
2206 }
2207 git_inflate_end(stream);
2208
2209 if (status != Z_STREAM_END) {
2210 error(_("corrupt loose object '%s'"), oid_to_hex(expected_oid));
2211 return -1;
2212 }
2213 if (stream->avail_in) {
2214 error(_("garbage at end of loose object '%s'"),
2215 oid_to_hex(expected_oid));
2216 return -1;
2217 }
2218
2219 the_hash_algo->final_fn(real_oid.hash, &c);
2220 if (!oideq(expected_oid, &real_oid)) {
2221 error(_("sha1 mismatch for %s (expected %s)"), path,
2222 oid_to_hex(expected_oid));
2223 return -1;
2224 }
2225
2226 return 0;
2227}
2228
2229int read_loose_object(const char *path,
2230 const struct object_id *expected_oid,
2231 enum object_type *type,
2232 unsigned long *size,
2233 void **contents)
2234{
2235 int ret = -1;
2236 void *map = NULL;
2237 unsigned long mapsize;
2238 git_zstream stream;
2239 char hdr[MAX_HEADER_LEN];
2240
2241 *contents = NULL;
2242
2243 map = map_loose_object_1(the_repository, path, NULL, &mapsize);
2244 if (!map) {
2245 error_errno(_("unable to mmap %s"), path);
2246 goto out;
2247 }
2248
2249 if (unpack_loose_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0) {
2250 error(_("unable to unpack header of %s"), path);
2251 goto out;
2252 }
2253
2254 *type = parse_loose_header(hdr, size);
2255 if (*type < 0) {
2256 error(_("unable to parse header of %s"), path);
2257 git_inflate_end(&stream);
2258 goto out;
2259 }
2260
2261 if (*type == OBJ_BLOB && *size > big_file_threshold) {
2262 if (check_stream_oid(&stream, hdr, *size, path, expected_oid) < 0)
2263 goto out;
2264 } else {
2265 *contents = unpack_loose_rest(&stream, hdr, *size, expected_oid);
2266 if (!*contents) {
2267 error(_("unable to unpack contents of %s"), path);
2268 git_inflate_end(&stream);
2269 goto out;
2270 }
2271 if (check_object_signature(expected_oid, *contents,
2272 *size, type_name(*type))) {
2273 error(_("sha1 mismatch for %s (expected %s)"), path,
2274 oid_to_hex(expected_oid));
2275 free(*contents);
2276 goto out;
2277 }
2278 }
2279
2280 ret = 0; /* everything checks out */
2281
2282out:
2283 if (map)
2284 munmap(map, mapsize);
2285 return ret;
2286}