e53da0b7013bc281f398565ddcc78bbc9a291319
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
349static const char *odb_loose_path(struct object_directory *odb,
350 struct strbuf *buf,
351 const unsigned char *sha1)
352{
353 strbuf_reset(buf);
354 strbuf_addstr(buf, odb->path);
355 strbuf_addch(buf, '/');
356 fill_sha1_path(buf, sha1);
357 return buf->buf;
358}
359
360const char *loose_object_path(struct repository *r, struct strbuf *buf,
361 const unsigned char *sha1)
362{
363 return odb_loose_path(r->objects->odb, buf, sha1);
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->hash);
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 "sha1" to detect object corruption.
802 * With "map" == NULL, try reading the object named with "sha1" 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 %lu", type_name(obj_type), 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 "sha1" 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_sha1_file().
881 */
882static int stat_sha1_file(struct repository *r, const unsigned char *sha1,
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, sha1);
891 if (!lstat(*path, st))
892 return 0;
893 }
894
895 return -1;
896}
897
898/*
899 * Like stat_sha1_file(), but actually open the object and return the
900 * descriptor. See the caveats on the "path" parameter above.
901 */
902static int open_sha1_file(struct repository *r,
903 const unsigned char *sha1, 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, sha1);
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 unsigned char *sha1)
926{
927 int subdir_nr = sha1[0];
928 struct object_id oid;
929 struct object_directory *odb;
930
931 hashcpy(oid.hash, sha1);
932
933 prepare_alt_odb(r);
934 for (odb = r->objects->odb; odb; odb = odb->next) {
935 odb_load_loose_cache(odb, subdir_nr);
936 if (oid_array_lookup(&odb->loose_objects_cache, &oid) >= 0)
937 return 1;
938 }
939 return 0;
940}
941
942/*
943 * Map the loose object at "path" if it is not NULL, or the path found by
944 * searching for a loose object named "sha1".
945 */
946static void *map_sha1_file_1(struct repository *r, const char *path,
947 const unsigned char *sha1, unsigned long *size)
948{
949 void *map;
950 int fd;
951
952 if (path)
953 fd = git_open(path);
954 else
955 fd = open_sha1_file(r, sha1, &path);
956 map = NULL;
957 if (fd >= 0) {
958 struct stat st;
959
960 if (!fstat(fd, &st)) {
961 *size = xsize_t(st.st_size);
962 if (!*size) {
963 /* mmap() is forbidden on empty files */
964 error(_("object file %s is empty"), path);
965 return NULL;
966 }
967 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
968 }
969 close(fd);
970 }
971 return map;
972}
973
974void *map_sha1_file(struct repository *r,
975 const unsigned char *sha1, unsigned long *size)
976{
977 return map_sha1_file_1(r, NULL, sha1, size);
978}
979
980static int unpack_sha1_short_header(git_zstream *stream,
981 unsigned char *map, unsigned long mapsize,
982 void *buffer, unsigned long bufsiz)
983{
984 /* Get the data stream */
985 memset(stream, 0, sizeof(*stream));
986 stream->next_in = map;
987 stream->avail_in = mapsize;
988 stream->next_out = buffer;
989 stream->avail_out = bufsiz;
990
991 git_inflate_init(stream);
992 return git_inflate(stream, 0);
993}
994
995int unpack_sha1_header(git_zstream *stream,
996 unsigned char *map, unsigned long mapsize,
997 void *buffer, unsigned long bufsiz)
998{
999 int status = unpack_sha1_short_header(stream, map, mapsize,
1000 buffer, bufsiz);
1001
1002 if (status < Z_OK)
1003 return status;
1004
1005 /* Make sure we have the terminating NUL */
1006 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1007 return -1;
1008 return 0;
1009}
1010
1011static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1012 unsigned long mapsize, void *buffer,
1013 unsigned long bufsiz, struct strbuf *header)
1014{
1015 int status;
1016
1017 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
1018 if (status < Z_OK)
1019 return -1;
1020
1021 /*
1022 * Check if entire header is unpacked in the first iteration.
1023 */
1024 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1025 return 0;
1026
1027 /*
1028 * buffer[0..bufsiz] was not large enough. Copy the partial
1029 * result out to header, and then append the result of further
1030 * reading the stream.
1031 */
1032 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1033 stream->next_out = buffer;
1034 stream->avail_out = bufsiz;
1035
1036 do {
1037 status = git_inflate(stream, 0);
1038 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1039 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1040 return 0;
1041 stream->next_out = buffer;
1042 stream->avail_out = bufsiz;
1043 } while (status != Z_STREAM_END);
1044 return -1;
1045}
1046
1047static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1048{
1049 int bytes = strlen(buffer) + 1;
1050 unsigned char *buf = xmallocz(size);
1051 unsigned long n;
1052 int status = Z_OK;
1053
1054 n = stream->total_out - bytes;
1055 if (n > size)
1056 n = size;
1057 memcpy(buf, (char *) buffer + bytes, n);
1058 bytes = n;
1059 if (bytes <= size) {
1060 /*
1061 * The above condition must be (bytes <= size), not
1062 * (bytes < size). In other words, even though we
1063 * expect no more output and set avail_out to zero,
1064 * the input zlib stream may have bytes that express
1065 * "this concludes the stream", and we *do* want to
1066 * eat that input.
1067 *
1068 * Otherwise we would not be able to test that we
1069 * consumed all the input to reach the expected size;
1070 * we also want to check that zlib tells us that all
1071 * went well with status == Z_STREAM_END at the end.
1072 */
1073 stream->next_out = buf + bytes;
1074 stream->avail_out = size - bytes;
1075 while (status == Z_OK)
1076 status = git_inflate(stream, Z_FINISH);
1077 }
1078 if (status == Z_STREAM_END && !stream->avail_in) {
1079 git_inflate_end(stream);
1080 return buf;
1081 }
1082
1083 if (status < 0)
1084 error(_("corrupt loose object '%s'"), sha1_to_hex(sha1));
1085 else if (stream->avail_in)
1086 error(_("garbage at end of loose object '%s'"),
1087 sha1_to_hex(sha1));
1088 free(buf);
1089 return NULL;
1090}
1091
1092/*
1093 * We used to just use "sscanf()", but that's actually way
1094 * too permissive for what we want to check. So do an anal
1095 * object header parse by hand.
1096 */
1097static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1098 unsigned int flags)
1099{
1100 const char *type_buf = hdr;
1101 unsigned long size;
1102 int type, type_len = 0;
1103
1104 /*
1105 * The type can be of any size but is followed by
1106 * a space.
1107 */
1108 for (;;) {
1109 char c = *hdr++;
1110 if (!c)
1111 return -1;
1112 if (c == ' ')
1113 break;
1114 type_len++;
1115 }
1116
1117 type = type_from_string_gently(type_buf, type_len, 1);
1118 if (oi->type_name)
1119 strbuf_add(oi->type_name, type_buf, type_len);
1120 /*
1121 * Set type to 0 if its an unknown object and
1122 * we're obtaining the type using '--allow-unknown-type'
1123 * option.
1124 */
1125 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
1126 type = 0;
1127 else if (type < 0)
1128 die(_("invalid object type"));
1129 if (oi->typep)
1130 *oi->typep = type;
1131
1132 /*
1133 * The length must follow immediately, and be in canonical
1134 * decimal format (ie "010" is not valid).
1135 */
1136 size = *hdr++ - '0';
1137 if (size > 9)
1138 return -1;
1139 if (size) {
1140 for (;;) {
1141 unsigned long c = *hdr - '0';
1142 if (c > 9)
1143 break;
1144 hdr++;
1145 size = size * 10 + c;
1146 }
1147 }
1148
1149 if (oi->sizep)
1150 *oi->sizep = size;
1151
1152 /*
1153 * The length must be followed by a zero byte
1154 */
1155 return *hdr ? -1 : type;
1156}
1157
1158int parse_sha1_header(const char *hdr, unsigned long *sizep)
1159{
1160 struct object_info oi = OBJECT_INFO_INIT;
1161
1162 oi.sizep = sizep;
1163 return parse_sha1_header_extended(hdr, &oi, 0);
1164}
1165
1166static int sha1_loose_object_info(struct repository *r,
1167 const unsigned char *sha1,
1168 struct object_info *oi, int flags)
1169{
1170 int status = 0;
1171 unsigned long mapsize;
1172 void *map;
1173 git_zstream stream;
1174 char hdr[MAX_HEADER_LEN];
1175 struct strbuf hdrbuf = STRBUF_INIT;
1176 unsigned long size_scratch;
1177
1178 if (oi->delta_base_sha1)
1179 hashclr(oi->delta_base_sha1);
1180
1181 /*
1182 * If we don't care about type or size, then we don't
1183 * need to look inside the object at all. Note that we
1184 * do not optimize out the stat call, even if the
1185 * caller doesn't care about the disk-size, since our
1186 * return value implicitly indicates whether the
1187 * object even exists.
1188 */
1189 if (!oi->typep && !oi->type_name && !oi->sizep && !oi->contentp) {
1190 const char *path;
1191 struct stat st;
1192 if (!oi->disk_sizep && (flags & OBJECT_INFO_QUICK))
1193 return quick_has_loose(r, sha1) ? 0 : -1;
1194 if (stat_sha1_file(r, sha1, &st, &path) < 0)
1195 return -1;
1196 if (oi->disk_sizep)
1197 *oi->disk_sizep = st.st_size;
1198 return 0;
1199 }
1200
1201 map = map_sha1_file(r, sha1, &mapsize);
1202 if (!map)
1203 return -1;
1204
1205 if (!oi->sizep)
1206 oi->sizep = &size_scratch;
1207
1208 if (oi->disk_sizep)
1209 *oi->disk_sizep = mapsize;
1210 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
1211 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
1212 status = error(_("unable to unpack %s header with --allow-unknown-type"),
1213 sha1_to_hex(sha1));
1214 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1215 status = error(_("unable to unpack %s header"),
1216 sha1_to_hex(sha1));
1217 if (status < 0)
1218 ; /* Do nothing */
1219 else if (hdrbuf.len) {
1220 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
1221 status = error(_("unable to parse %s header with --allow-unknown-type"),
1222 sha1_to_hex(sha1));
1223 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
1224 status = error(_("unable to parse %s header"), sha1_to_hex(sha1));
1225
1226 if (status >= 0 && oi->contentp) {
1227 *oi->contentp = unpack_sha1_rest(&stream, hdr,
1228 *oi->sizep, sha1);
1229 if (!*oi->contentp) {
1230 git_inflate_end(&stream);
1231 status = -1;
1232 }
1233 } else
1234 git_inflate_end(&stream);
1235
1236 munmap(map, mapsize);
1237 if (status && oi->typep)
1238 *oi->typep = status;
1239 if (oi->sizep == &size_scratch)
1240 oi->sizep = NULL;
1241 strbuf_release(&hdrbuf);
1242 oi->whence = OI_LOOSE;
1243 return (status < 0) ? status : 0;
1244}
1245
1246int fetch_if_missing = 1;
1247
1248int oid_object_info_extended(struct repository *r, const struct object_id *oid,
1249 struct object_info *oi, unsigned flags)
1250{
1251 static struct object_info blank_oi = OBJECT_INFO_INIT;
1252 struct pack_entry e;
1253 int rtype;
1254 const struct object_id *real = oid;
1255 int already_retried = 0;
1256
1257 if (flags & OBJECT_INFO_LOOKUP_REPLACE)
1258 real = lookup_replace_object(r, oid);
1259
1260 if (is_null_oid(real))
1261 return -1;
1262
1263 if (!oi)
1264 oi = &blank_oi;
1265
1266 if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
1267 struct cached_object *co = find_cached_object(real);
1268 if (co) {
1269 if (oi->typep)
1270 *(oi->typep) = co->type;
1271 if (oi->sizep)
1272 *(oi->sizep) = co->size;
1273 if (oi->disk_sizep)
1274 *(oi->disk_sizep) = 0;
1275 if (oi->delta_base_sha1)
1276 hashclr(oi->delta_base_sha1);
1277 if (oi->type_name)
1278 strbuf_addstr(oi->type_name, type_name(co->type));
1279 if (oi->contentp)
1280 *oi->contentp = xmemdupz(co->buf, co->size);
1281 oi->whence = OI_CACHED;
1282 return 0;
1283 }
1284 }
1285
1286 while (1) {
1287 if (find_pack_entry(r, real, &e))
1288 break;
1289
1290 if (flags & OBJECT_INFO_IGNORE_LOOSE)
1291 return -1;
1292
1293 /* Most likely it's a loose object. */
1294 if (!sha1_loose_object_info(r, real->hash, oi, flags))
1295 return 0;
1296
1297 /* Not a loose object; someone else may have just packed it. */
1298 if (!(flags & OBJECT_INFO_QUICK)) {
1299 reprepare_packed_git(r);
1300 if (find_pack_entry(r, real, &e))
1301 break;
1302 }
1303
1304 /* Check if it is a missing object */
1305 if (fetch_if_missing && repository_format_partial_clone &&
1306 !already_retried && r == the_repository) {
1307 /*
1308 * TODO Investigate having fetch_object() return
1309 * TODO error/success and stopping the music here.
1310 * TODO Pass a repository struct through fetch_object,
1311 * such that arbitrary repositories work.
1312 */
1313 fetch_objects(repository_format_partial_clone, real, 1);
1314 already_retried = 1;
1315 continue;
1316 }
1317
1318 return -1;
1319 }
1320
1321 if (oi == &blank_oi)
1322 /*
1323 * We know that the caller doesn't actually need the
1324 * information below, so return early.
1325 */
1326 return 0;
1327 rtype = packed_object_info(r, e.p, e.offset, oi);
1328 if (rtype < 0) {
1329 mark_bad_packed_object(e.p, real->hash);
1330 return oid_object_info_extended(r, real, oi, 0);
1331 } else if (oi->whence == OI_PACKED) {
1332 oi->u.packed.offset = e.offset;
1333 oi->u.packed.pack = e.p;
1334 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
1335 rtype == OBJ_OFS_DELTA);
1336 }
1337
1338 return 0;
1339}
1340
1341/* returns enum object_type or negative */
1342int oid_object_info(struct repository *r,
1343 const struct object_id *oid,
1344 unsigned long *sizep)
1345{
1346 enum object_type type;
1347 struct object_info oi = OBJECT_INFO_INIT;
1348
1349 oi.typep = &type;
1350 oi.sizep = sizep;
1351 if (oid_object_info_extended(r, oid, &oi,
1352 OBJECT_INFO_LOOKUP_REPLACE) < 0)
1353 return -1;
1354 return type;
1355}
1356
1357static void *read_object(const unsigned char *sha1, enum object_type *type,
1358 unsigned long *size)
1359{
1360 struct object_id oid;
1361 struct object_info oi = OBJECT_INFO_INIT;
1362 void *content;
1363 oi.typep = type;
1364 oi.sizep = size;
1365 oi.contentp = &content;
1366
1367 hashcpy(oid.hash, sha1);
1368
1369 if (oid_object_info_extended(the_repository, &oid, &oi, 0) < 0)
1370 return NULL;
1371 return content;
1372}
1373
1374int pretend_object_file(void *buf, unsigned long len, enum object_type type,
1375 struct object_id *oid)
1376{
1377 struct cached_object *co;
1378
1379 hash_object_file(buf, len, type_name(type), oid);
1380 if (has_sha1_file(oid->hash) || find_cached_object(oid))
1381 return 0;
1382 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
1383 co = &cached_objects[cached_object_nr++];
1384 co->size = len;
1385 co->type = type;
1386 co->buf = xmalloc(len);
1387 memcpy(co->buf, buf, len);
1388 oidcpy(&co->oid, oid);
1389 return 0;
1390}
1391
1392/*
1393 * This function dies on corrupt objects; the callers who want to
1394 * deal with them should arrange to call read_object() and give error
1395 * messages themselves.
1396 */
1397void *read_object_file_extended(const struct object_id *oid,
1398 enum object_type *type,
1399 unsigned long *size,
1400 int lookup_replace)
1401{
1402 void *data;
1403 const struct packed_git *p;
1404 const char *path;
1405 struct stat st;
1406 const struct object_id *repl = lookup_replace ?
1407 lookup_replace_object(the_repository, oid) : oid;
1408
1409 errno = 0;
1410 data = read_object(repl->hash, type, size);
1411 if (data)
1412 return data;
1413
1414 if (errno && errno != ENOENT)
1415 die_errno(_("failed to read object %s"), oid_to_hex(oid));
1416
1417 /* die if we replaced an object with one that does not exist */
1418 if (repl != oid)
1419 die(_("replacement %s not found for %s"),
1420 oid_to_hex(repl), oid_to_hex(oid));
1421
1422 if (!stat_sha1_file(the_repository, repl->hash, &st, &path))
1423 die(_("loose object %s (stored in %s) is corrupt"),
1424 oid_to_hex(repl), path);
1425
1426 if ((p = has_packed_and_bad(repl->hash)) != NULL)
1427 die(_("packed object %s (stored in %s) is corrupt"),
1428 oid_to_hex(repl), p->pack_name);
1429
1430 return NULL;
1431}
1432
1433void *read_object_with_reference(const struct object_id *oid,
1434 const char *required_type_name,
1435 unsigned long *size,
1436 struct object_id *actual_oid_return)
1437{
1438 enum object_type type, required_type;
1439 void *buffer;
1440 unsigned long isize;
1441 struct object_id actual_oid;
1442
1443 required_type = type_from_string(required_type_name);
1444 oidcpy(&actual_oid, oid);
1445 while (1) {
1446 int ref_length = -1;
1447 const char *ref_type = NULL;
1448
1449 buffer = read_object_file(&actual_oid, &type, &isize);
1450 if (!buffer)
1451 return NULL;
1452 if (type == required_type) {
1453 *size = isize;
1454 if (actual_oid_return)
1455 oidcpy(actual_oid_return, &actual_oid);
1456 return buffer;
1457 }
1458 /* Handle references */
1459 else if (type == OBJ_COMMIT)
1460 ref_type = "tree ";
1461 else if (type == OBJ_TAG)
1462 ref_type = "object ";
1463 else {
1464 free(buffer);
1465 return NULL;
1466 }
1467 ref_length = strlen(ref_type);
1468
1469 if (ref_length + the_hash_algo->hexsz > isize ||
1470 memcmp(buffer, ref_type, ref_length) ||
1471 get_oid_hex((char *) buffer + ref_length, &actual_oid)) {
1472 free(buffer);
1473 return NULL;
1474 }
1475 free(buffer);
1476 /* Now we have the ID of the referred-to object in
1477 * actual_oid. Check again. */
1478 }
1479}
1480
1481static void write_object_file_prepare(const void *buf, unsigned long len,
1482 const char *type, struct object_id *oid,
1483 char *hdr, int *hdrlen)
1484{
1485 git_hash_ctx c;
1486
1487 /* Generate the header */
1488 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
1489
1490 /* Sha1.. */
1491 the_hash_algo->init_fn(&c);
1492 the_hash_algo->update_fn(&c, hdr, *hdrlen);
1493 the_hash_algo->update_fn(&c, buf, len);
1494 the_hash_algo->final_fn(oid->hash, &c);
1495}
1496
1497/*
1498 * Move the just written object into its final resting place.
1499 */
1500int finalize_object_file(const char *tmpfile, const char *filename)
1501{
1502 int ret = 0;
1503
1504 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
1505 goto try_rename;
1506 else if (link(tmpfile, filename))
1507 ret = errno;
1508
1509 /*
1510 * Coda hack - coda doesn't like cross-directory links,
1511 * so we fall back to a rename, which will mean that it
1512 * won't be able to check collisions, but that's not a
1513 * big deal.
1514 *
1515 * The same holds for FAT formatted media.
1516 *
1517 * When this succeeds, we just return. We have nothing
1518 * left to unlink.
1519 */
1520 if (ret && ret != EEXIST) {
1521 try_rename:
1522 if (!rename(tmpfile, filename))
1523 goto out;
1524 ret = errno;
1525 }
1526 unlink_or_warn(tmpfile);
1527 if (ret) {
1528 if (ret != EEXIST) {
1529 return error_errno(_("unable to write sha1 filename %s"), filename);
1530 }
1531 /* FIXME!!! Collision check here ? */
1532 }
1533
1534out:
1535 if (adjust_shared_perm(filename))
1536 return error(_("unable to set permission to '%s'"), filename);
1537 return 0;
1538}
1539
1540static int write_buffer(int fd, const void *buf, size_t len)
1541{
1542 if (write_in_full(fd, buf, len) < 0)
1543 return error_errno(_("file write error"));
1544 return 0;
1545}
1546
1547int hash_object_file(const void *buf, unsigned long len, const char *type,
1548 struct object_id *oid)
1549{
1550 char hdr[MAX_HEADER_LEN];
1551 int hdrlen = sizeof(hdr);
1552 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1553 return 0;
1554}
1555
1556/* Finalize a file on disk, and close it. */
1557static void close_sha1_file(int fd)
1558{
1559 if (fsync_object_files)
1560 fsync_or_die(fd, "sha1 file");
1561 if (close(fd) != 0)
1562 die_errno(_("error when closing sha1 file"));
1563}
1564
1565/* Size of directory component, including the ending '/' */
1566static inline int directory_size(const char *filename)
1567{
1568 const char *s = strrchr(filename, '/');
1569 if (!s)
1570 return 0;
1571 return s - filename + 1;
1572}
1573
1574/*
1575 * This creates a temporary file in the same directory as the final
1576 * 'filename'
1577 *
1578 * We want to avoid cross-directory filename renames, because those
1579 * can have problems on various filesystems (FAT, NFS, Coda).
1580 */
1581static int create_tmpfile(struct strbuf *tmp, const char *filename)
1582{
1583 int fd, dirlen = directory_size(filename);
1584
1585 strbuf_reset(tmp);
1586 strbuf_add(tmp, filename, dirlen);
1587 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
1588 fd = git_mkstemp_mode(tmp->buf, 0444);
1589 if (fd < 0 && dirlen && errno == ENOENT) {
1590 /*
1591 * Make sure the directory exists; note that the contents
1592 * of the buffer are undefined after mkstemp returns an
1593 * error, so we have to rewrite the whole buffer from
1594 * scratch.
1595 */
1596 strbuf_reset(tmp);
1597 strbuf_add(tmp, filename, dirlen - 1);
1598 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
1599 return -1;
1600 if (adjust_shared_perm(tmp->buf))
1601 return -1;
1602
1603 /* Try again */
1604 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
1605 fd = git_mkstemp_mode(tmp->buf, 0444);
1606 }
1607 return fd;
1608}
1609
1610static int write_loose_object(const struct object_id *oid, char *hdr,
1611 int hdrlen, const void *buf, unsigned long len,
1612 time_t mtime)
1613{
1614 int fd, ret;
1615 unsigned char compressed[4096];
1616 git_zstream stream;
1617 git_hash_ctx c;
1618 struct object_id parano_oid;
1619 static struct strbuf tmp_file = STRBUF_INIT;
1620 static struct strbuf filename = STRBUF_INIT;
1621
1622 loose_object_path(the_repository, &filename, oid->hash);
1623
1624 fd = create_tmpfile(&tmp_file, filename.buf);
1625 if (fd < 0) {
1626 if (errno == EACCES)
1627 return error(_("insufficient permission for adding an object to repository database %s"), get_object_directory());
1628 else
1629 return error_errno(_("unable to create temporary file"));
1630 }
1631
1632 /* Set it up */
1633 git_deflate_init(&stream, zlib_compression_level);
1634 stream.next_out = compressed;
1635 stream.avail_out = sizeof(compressed);
1636 the_hash_algo->init_fn(&c);
1637
1638 /* First header.. */
1639 stream.next_in = (unsigned char *)hdr;
1640 stream.avail_in = hdrlen;
1641 while (git_deflate(&stream, 0) == Z_OK)
1642 ; /* nothing */
1643 the_hash_algo->update_fn(&c, hdr, hdrlen);
1644
1645 /* Then the data itself.. */
1646 stream.next_in = (void *)buf;
1647 stream.avail_in = len;
1648 do {
1649 unsigned char *in0 = stream.next_in;
1650 ret = git_deflate(&stream, Z_FINISH);
1651 the_hash_algo->update_fn(&c, in0, stream.next_in - in0);
1652 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
1653 die(_("unable to write sha1 file"));
1654 stream.next_out = compressed;
1655 stream.avail_out = sizeof(compressed);
1656 } while (ret == Z_OK);
1657
1658 if (ret != Z_STREAM_END)
1659 die(_("unable to deflate new object %s (%d)"), oid_to_hex(oid),
1660 ret);
1661 ret = git_deflate_end_gently(&stream);
1662 if (ret != Z_OK)
1663 die(_("deflateEnd on object %s failed (%d)"), oid_to_hex(oid),
1664 ret);
1665 the_hash_algo->final_fn(parano_oid.hash, &c);
1666 if (!oideq(oid, ¶no_oid))
1667 die(_("confused by unstable object source data for %s"),
1668 oid_to_hex(oid));
1669
1670 close_sha1_file(fd);
1671
1672 if (mtime) {
1673 struct utimbuf utb;
1674 utb.actime = mtime;
1675 utb.modtime = mtime;
1676 if (utime(tmp_file.buf, &utb) < 0)
1677 warning_errno(_("failed utime() on %s"), tmp_file.buf);
1678 }
1679
1680 return finalize_object_file(tmp_file.buf, filename.buf);
1681}
1682
1683static int freshen_loose_object(const struct object_id *oid)
1684{
1685 return check_and_freshen(oid, 1);
1686}
1687
1688static int freshen_packed_object(const struct object_id *oid)
1689{
1690 struct pack_entry e;
1691 if (!find_pack_entry(the_repository, oid, &e))
1692 return 0;
1693 if (e.p->freshened)
1694 return 1;
1695 if (!freshen_file(e.p->pack_name))
1696 return 0;
1697 e.p->freshened = 1;
1698 return 1;
1699}
1700
1701int write_object_file(const void *buf, unsigned long len, const char *type,
1702 struct object_id *oid)
1703{
1704 char hdr[MAX_HEADER_LEN];
1705 int hdrlen = sizeof(hdr);
1706
1707 /* Normally if we have it in the pack then we do not bother writing
1708 * it out into .git/objects/??/?{38} file.
1709 */
1710 write_object_file_prepare(buf, len, type, oid, hdr, &hdrlen);
1711 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1712 return 0;
1713 return write_loose_object(oid, hdr, hdrlen, buf, len, 0);
1714}
1715
1716int hash_object_file_literally(const void *buf, unsigned long len,
1717 const char *type, struct object_id *oid,
1718 unsigned flags)
1719{
1720 char *header;
1721 int hdrlen, status = 0;
1722
1723 /* type string, SP, %lu of the length plus NUL must fit this */
1724 hdrlen = strlen(type) + MAX_HEADER_LEN;
1725 header = xmalloc(hdrlen);
1726 write_object_file_prepare(buf, len, type, oid, header, &hdrlen);
1727
1728 if (!(flags & HASH_WRITE_OBJECT))
1729 goto cleanup;
1730 if (freshen_packed_object(oid) || freshen_loose_object(oid))
1731 goto cleanup;
1732 status = write_loose_object(oid, header, hdrlen, buf, len, 0);
1733
1734cleanup:
1735 free(header);
1736 return status;
1737}
1738
1739int force_object_loose(const struct object_id *oid, time_t mtime)
1740{
1741 void *buf;
1742 unsigned long len;
1743 enum object_type type;
1744 char hdr[MAX_HEADER_LEN];
1745 int hdrlen;
1746 int ret;
1747
1748 if (has_loose_object(oid))
1749 return 0;
1750 buf = read_object(oid->hash, &type, &len);
1751 if (!buf)
1752 return error(_("cannot read sha1_file for %s"), oid_to_hex(oid));
1753 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", type_name(type), len) + 1;
1754 ret = write_loose_object(oid, hdr, hdrlen, buf, len, mtime);
1755 free(buf);
1756
1757 return ret;
1758}
1759
1760int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
1761{
1762 struct object_id oid;
1763 if (!startup_info->have_repository)
1764 return 0;
1765 hashcpy(oid.hash, sha1);
1766 return oid_object_info_extended(the_repository, &oid, NULL,
1767 flags | OBJECT_INFO_SKIP_CACHED) >= 0;
1768}
1769
1770int has_object_file(const struct object_id *oid)
1771{
1772 return has_sha1_file(oid->hash);
1773}
1774
1775int has_object_file_with_flags(const struct object_id *oid, int flags)
1776{
1777 return has_sha1_file_with_flags(oid->hash, flags);
1778}
1779
1780static void check_tree(const void *buf, size_t size)
1781{
1782 struct tree_desc desc;
1783 struct name_entry entry;
1784
1785 init_tree_desc(&desc, buf, size);
1786 while (tree_entry(&desc, &entry))
1787 /* do nothing
1788 * tree_entry() will die() on malformed entries */
1789 ;
1790}
1791
1792static void check_commit(const void *buf, size_t size)
1793{
1794 struct commit c;
1795 memset(&c, 0, sizeof(c));
1796 if (parse_commit_buffer(the_repository, &c, buf, size, 0))
1797 die(_("corrupt commit"));
1798}
1799
1800static void check_tag(const void *buf, size_t size)
1801{
1802 struct tag t;
1803 memset(&t, 0, sizeof(t));
1804 if (parse_tag_buffer(the_repository, &t, buf, size))
1805 die(_("corrupt tag"));
1806}
1807
1808static int index_mem(struct index_state *istate,
1809 struct object_id *oid, void *buf, size_t size,
1810 enum object_type type,
1811 const char *path, unsigned flags)
1812{
1813 int ret, re_allocated = 0;
1814 int write_object = flags & HASH_WRITE_OBJECT;
1815
1816 if (!type)
1817 type = OBJ_BLOB;
1818
1819 /*
1820 * Convert blobs to git internal format
1821 */
1822 if ((type == OBJ_BLOB) && path) {
1823 struct strbuf nbuf = STRBUF_INIT;
1824 if (convert_to_git(istate, path, buf, size, &nbuf,
1825 get_conv_flags(flags))) {
1826 buf = strbuf_detach(&nbuf, &size);
1827 re_allocated = 1;
1828 }
1829 }
1830 if (flags & HASH_FORMAT_CHECK) {
1831 if (type == OBJ_TREE)
1832 check_tree(buf, size);
1833 if (type == OBJ_COMMIT)
1834 check_commit(buf, size);
1835 if (type == OBJ_TAG)
1836 check_tag(buf, size);
1837 }
1838
1839 if (write_object)
1840 ret = write_object_file(buf, size, type_name(type), oid);
1841 else
1842 ret = hash_object_file(buf, size, type_name(type), oid);
1843 if (re_allocated)
1844 free(buf);
1845 return ret;
1846}
1847
1848static int index_stream_convert_blob(struct index_state *istate,
1849 struct object_id *oid,
1850 int fd,
1851 const char *path,
1852 unsigned flags)
1853{
1854 int ret;
1855 const int write_object = flags & HASH_WRITE_OBJECT;
1856 struct strbuf sbuf = STRBUF_INIT;
1857
1858 assert(path);
1859 assert(would_convert_to_git_filter_fd(istate, path));
1860
1861 convert_to_git_filter_fd(istate, path, fd, &sbuf,
1862 get_conv_flags(flags));
1863
1864 if (write_object)
1865 ret = write_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1866 oid);
1867 else
1868 ret = hash_object_file(sbuf.buf, sbuf.len, type_name(OBJ_BLOB),
1869 oid);
1870 strbuf_release(&sbuf);
1871 return ret;
1872}
1873
1874static int index_pipe(struct index_state *istate, struct object_id *oid,
1875 int fd, enum object_type type,
1876 const char *path, unsigned flags)
1877{
1878 struct strbuf sbuf = STRBUF_INIT;
1879 int ret;
1880
1881 if (strbuf_read(&sbuf, fd, 4096) >= 0)
1882 ret = index_mem(istate, oid, sbuf.buf, sbuf.len, type, path, flags);
1883 else
1884 ret = -1;
1885 strbuf_release(&sbuf);
1886 return ret;
1887}
1888
1889#define SMALL_FILE_SIZE (32*1024)
1890
1891static int index_core(struct index_state *istate,
1892 struct object_id *oid, int fd, size_t size,
1893 enum object_type type, const char *path,
1894 unsigned flags)
1895{
1896 int ret;
1897
1898 if (!size) {
1899 ret = index_mem(istate, oid, "", size, type, path, flags);
1900 } else if (size <= SMALL_FILE_SIZE) {
1901 char *buf = xmalloc(size);
1902 ssize_t read_result = read_in_full(fd, buf, size);
1903 if (read_result < 0)
1904 ret = error_errno(_("read error while indexing %s"),
1905 path ? path : "<unknown>");
1906 else if (read_result != size)
1907 ret = error(_("short read while indexing %s"),
1908 path ? path : "<unknown>");
1909 else
1910 ret = index_mem(istate, oid, buf, size, type, path, flags);
1911 free(buf);
1912 } else {
1913 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1914 ret = index_mem(istate, oid, buf, size, type, path, flags);
1915 munmap(buf, size);
1916 }
1917 return ret;
1918}
1919
1920/*
1921 * This creates one packfile per large blob unless bulk-checkin
1922 * machinery is "plugged".
1923 *
1924 * This also bypasses the usual "convert-to-git" dance, and that is on
1925 * purpose. We could write a streaming version of the converting
1926 * functions and insert that before feeding the data to fast-import
1927 * (or equivalent in-core API described above). However, that is
1928 * somewhat complicated, as we do not know the size of the filter
1929 * result, which we need to know beforehand when writing a git object.
1930 * Since the primary motivation for trying to stream from the working
1931 * tree file and to avoid mmaping it in core is to deal with large
1932 * binary blobs, they generally do not want to get any conversion, and
1933 * callers should avoid this code path when filters are requested.
1934 */
1935static int index_stream(struct object_id *oid, int fd, size_t size,
1936 enum object_type type, const char *path,
1937 unsigned flags)
1938{
1939 return index_bulk_checkin(oid, fd, size, type, path, flags);
1940}
1941
1942int index_fd(struct index_state *istate, struct object_id *oid,
1943 int fd, struct stat *st,
1944 enum object_type type, const char *path, unsigned flags)
1945{
1946 int ret;
1947
1948 /*
1949 * Call xsize_t() only when needed to avoid potentially unnecessary
1950 * die() for large files.
1951 */
1952 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(istate, path))
1953 ret = index_stream_convert_blob(istate, oid, fd, path, flags);
1954 else if (!S_ISREG(st->st_mode))
1955 ret = index_pipe(istate, oid, fd, type, path, flags);
1956 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
1957 (path && would_convert_to_git(istate, path)))
1958 ret = index_core(istate, oid, fd, xsize_t(st->st_size),
1959 type, path, flags);
1960 else
1961 ret = index_stream(oid, fd, xsize_t(st->st_size), type, path,
1962 flags);
1963 close(fd);
1964 return ret;
1965}
1966
1967int index_path(struct index_state *istate, struct object_id *oid,
1968 const char *path, struct stat *st, unsigned flags)
1969{
1970 int fd;
1971 struct strbuf sb = STRBUF_INIT;
1972 int rc = 0;
1973
1974 switch (st->st_mode & S_IFMT) {
1975 case S_IFREG:
1976 fd = open(path, O_RDONLY);
1977 if (fd < 0)
1978 return error_errno("open(\"%s\")", path);
1979 if (index_fd(istate, oid, fd, st, OBJ_BLOB, path, flags) < 0)
1980 return error(_("%s: failed to insert into database"),
1981 path);
1982 break;
1983 case S_IFLNK:
1984 if (strbuf_readlink(&sb, path, st->st_size))
1985 return error_errno("readlink(\"%s\")", path);
1986 if (!(flags & HASH_WRITE_OBJECT))
1987 hash_object_file(sb.buf, sb.len, blob_type, oid);
1988 else if (write_object_file(sb.buf, sb.len, blob_type, oid))
1989 rc = error(_("%s: failed to insert into database"), path);
1990 strbuf_release(&sb);
1991 break;
1992 case S_IFDIR:
1993 return resolve_gitlink_ref(path, "HEAD", oid);
1994 default:
1995 return error(_("%s: unsupported file type"), path);
1996 }
1997 return rc;
1998}
1999
2000int read_pack_header(int fd, struct pack_header *header)
2001{
2002 if (read_in_full(fd, header, sizeof(*header)) != sizeof(*header))
2003 /* "eof before pack header was fully read" */
2004 return PH_ERROR_EOF;
2005
2006 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2007 /* "protocol error (pack signature mismatch detected)" */
2008 return PH_ERROR_PACK_SIGNATURE;
2009 if (!pack_version_ok(header->hdr_version))
2010 /* "protocol error (pack version unsupported)" */
2011 return PH_ERROR_PROTOCOL;
2012 return 0;
2013}
2014
2015void assert_oid_type(const struct object_id *oid, enum object_type expect)
2016{
2017 enum object_type type = oid_object_info(the_repository, oid, NULL);
2018 if (type < 0)
2019 die(_("%s is not a valid object"), oid_to_hex(oid));
2020 if (type != expect)
2021 die(_("%s is not a valid '%s' object"), oid_to_hex(oid),
2022 type_name(expect));
2023}
2024
2025int for_each_file_in_obj_subdir(unsigned int subdir_nr,
2026 struct strbuf *path,
2027 each_loose_object_fn obj_cb,
2028 each_loose_cruft_fn cruft_cb,
2029 each_loose_subdir_fn subdir_cb,
2030 void *data)
2031{
2032 size_t origlen, baselen;
2033 DIR *dir;
2034 struct dirent *de;
2035 int r = 0;
2036 struct object_id oid;
2037
2038 if (subdir_nr > 0xff)
2039 BUG("invalid loose object subdirectory: %x", subdir_nr);
2040
2041 origlen = path->len;
2042 strbuf_complete(path, '/');
2043 strbuf_addf(path, "%02x", subdir_nr);
2044
2045 dir = opendir(path->buf);
2046 if (!dir) {
2047 if (errno != ENOENT)
2048 r = error_errno(_("unable to open %s"), path->buf);
2049 strbuf_setlen(path, origlen);
2050 return r;
2051 }
2052
2053 oid.hash[0] = subdir_nr;
2054 strbuf_addch(path, '/');
2055 baselen = path->len;
2056
2057 while ((de = readdir(dir))) {
2058 size_t namelen;
2059 if (is_dot_or_dotdot(de->d_name))
2060 continue;
2061
2062 namelen = strlen(de->d_name);
2063 strbuf_setlen(path, baselen);
2064 strbuf_add(path, de->d_name, namelen);
2065 if (namelen == the_hash_algo->hexsz - 2 &&
2066 !hex_to_bytes(oid.hash + 1, de->d_name,
2067 the_hash_algo->rawsz - 1)) {
2068 if (obj_cb) {
2069 r = obj_cb(&oid, path->buf, data);
2070 if (r)
2071 break;
2072 }
2073 continue;
2074 }
2075
2076 if (cruft_cb) {
2077 r = cruft_cb(de->d_name, path->buf, data);
2078 if (r)
2079 break;
2080 }
2081 }
2082 closedir(dir);
2083
2084 strbuf_setlen(path, baselen - 1);
2085 if (!r && subdir_cb)
2086 r = subdir_cb(subdir_nr, path->buf, data);
2087
2088 strbuf_setlen(path, origlen);
2089
2090 return r;
2091}
2092
2093int for_each_loose_file_in_objdir_buf(struct strbuf *path,
2094 each_loose_object_fn obj_cb,
2095 each_loose_cruft_fn cruft_cb,
2096 each_loose_subdir_fn subdir_cb,
2097 void *data)
2098{
2099 int r = 0;
2100 int i;
2101
2102 for (i = 0; i < 256; i++) {
2103 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
2104 subdir_cb, data);
2105 if (r)
2106 break;
2107 }
2108
2109 return r;
2110}
2111
2112int for_each_loose_file_in_objdir(const char *path,
2113 each_loose_object_fn obj_cb,
2114 each_loose_cruft_fn cruft_cb,
2115 each_loose_subdir_fn subdir_cb,
2116 void *data)
2117{
2118 struct strbuf buf = STRBUF_INIT;
2119 int r;
2120
2121 strbuf_addstr(&buf, path);
2122 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
2123 subdir_cb, data);
2124 strbuf_release(&buf);
2125
2126 return r;
2127}
2128
2129int for_each_loose_object(each_loose_object_fn cb, void *data,
2130 enum for_each_object_flags flags)
2131{
2132 struct object_directory *odb;
2133
2134 prepare_alt_odb(the_repository);
2135 for (odb = the_repository->objects->odb; odb; odb = odb->next) {
2136 int r = for_each_loose_file_in_objdir(odb->path, cb, NULL,
2137 NULL, data);
2138 if (r)
2139 return r;
2140
2141 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
2142 break;
2143 }
2144
2145 return 0;
2146}
2147
2148static int append_loose_object(const struct object_id *oid, const char *path,
2149 void *data)
2150{
2151 oid_array_append(data, oid);
2152 return 0;
2153}
2154
2155void odb_load_loose_cache(struct object_directory *odb, int subdir_nr)
2156{
2157 struct strbuf buf = STRBUF_INIT;
2158
2159 if (subdir_nr < 0 ||
2160 subdir_nr >= ARRAY_SIZE(odb->loose_objects_subdir_seen))
2161 BUG("subdir_nr out of range");
2162
2163 if (odb->loose_objects_subdir_seen[subdir_nr])
2164 return;
2165
2166 strbuf_addstr(&buf, odb->path);
2167 for_each_file_in_obj_subdir(subdir_nr, &buf,
2168 append_loose_object,
2169 NULL, NULL,
2170 &odb->loose_objects_cache);
2171 odb->loose_objects_subdir_seen[subdir_nr] = 1;
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}