Merge branch 'jc/config-case-cmdline-take-2' into maint
[git/git.git] / sha1_file.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "string-list.h"
11 #include "lockfile.h"
12 #include "delta.h"
13 #include "pack.h"
14 #include "blob.h"
15 #include "commit.h"
16 #include "run-command.h"
17 #include "tag.h"
18 #include "tree.h"
19 #include "tree-walk.h"
20 #include "refs.h"
21 #include "pack-revindex.h"
22 #include "sha1-lookup.h"
23 #include "bulk-checkin.h"
24 #include "streaming.h"
25 #include "dir.h"
26 #include "mru.h"
27 #include "list.h"
28 #include "mergesort.h"
29 #include "quote.h"
30
31 #define SZ_FMT PRIuMAX
32 static inline uintmax_t sz_fmt(size_t s) { return s; }
33
34 const unsigned char null_sha1[20];
35 const struct object_id null_oid;
36 const struct object_id empty_tree_oid = {
37 EMPTY_TREE_SHA1_BIN_LITERAL
38 };
39 const struct object_id empty_blob_oid = {
40 EMPTY_BLOB_SHA1_BIN_LITERAL
41 };
42
43 /*
44 * This is meant to hold a *small* number of objects that you would
45 * want read_sha1_file() to be able to return, but yet you do not want
46 * to write them into the object store (e.g. a browse-only
47 * application).
48 */
49 static struct cached_object {
50 unsigned char sha1[20];
51 enum object_type type;
52 void *buf;
53 unsigned long size;
54 } *cached_objects;
55 static int cached_object_nr, cached_object_alloc;
56
57 static struct cached_object empty_tree = {
58 EMPTY_TREE_SHA1_BIN_LITERAL,
59 OBJ_TREE,
60 "",
61 0
62 };
63
64 static struct cached_object *find_cached_object(const unsigned char *sha1)
65 {
66 int i;
67 struct cached_object *co = cached_objects;
68
69 for (i = 0; i < cached_object_nr; i++, co++) {
70 if (!hashcmp(co->sha1, sha1))
71 return co;
72 }
73 if (!hashcmp(sha1, empty_tree.sha1))
74 return &empty_tree;
75 return NULL;
76 }
77
78 int mkdir_in_gitdir(const char *path)
79 {
80 if (mkdir(path, 0777)) {
81 int saved_errno = errno;
82 struct stat st;
83 struct strbuf sb = STRBUF_INIT;
84
85 if (errno != EEXIST)
86 return -1;
87 /*
88 * Are we looking at a path in a symlinked worktree
89 * whose original repository does not yet have it?
90 * e.g. .git/rr-cache pointing at its original
91 * repository in which the user hasn't performed any
92 * conflict resolution yet?
93 */
94 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
95 strbuf_readlink(&sb, path, st.st_size) ||
96 !is_absolute_path(sb.buf) ||
97 mkdir(sb.buf, 0777)) {
98 strbuf_release(&sb);
99 errno = saved_errno;
100 return -1;
101 }
102 strbuf_release(&sb);
103 }
104 return adjust_shared_perm(path);
105 }
106
107 enum scld_error safe_create_leading_directories(char *path)
108 {
109 char *next_component = path + offset_1st_component(path);
110 enum scld_error ret = SCLD_OK;
111
112 while (ret == SCLD_OK && next_component) {
113 struct stat st;
114 char *slash = next_component, slash_character;
115
116 while (*slash && !is_dir_sep(*slash))
117 slash++;
118
119 if (!*slash)
120 break;
121
122 next_component = slash + 1;
123 while (is_dir_sep(*next_component))
124 next_component++;
125 if (!*next_component)
126 break;
127
128 slash_character = *slash;
129 *slash = '\0';
130 if (!stat(path, &st)) {
131 /* path exists */
132 if (!S_ISDIR(st.st_mode))
133 ret = SCLD_EXISTS;
134 } else if (mkdir(path, 0777)) {
135 if (errno == EEXIST &&
136 !stat(path, &st) && S_ISDIR(st.st_mode))
137 ; /* somebody created it since we checked */
138 else if (errno == ENOENT)
139 /*
140 * Either mkdir() failed because
141 * somebody just pruned the containing
142 * directory, or stat() failed because
143 * the file that was in our way was
144 * just removed. Either way, inform
145 * the caller that it might be worth
146 * trying again:
147 */
148 ret = SCLD_VANISHED;
149 else
150 ret = SCLD_FAILED;
151 } else if (adjust_shared_perm(path)) {
152 ret = SCLD_PERMS;
153 }
154 *slash = slash_character;
155 }
156 return ret;
157 }
158
159 enum scld_error safe_create_leading_directories_const(const char *path)
160 {
161 /* path points to cache entries, so xstrdup before messing with it */
162 char *buf = xstrdup(path);
163 enum scld_error result = safe_create_leading_directories(buf);
164 free(buf);
165 return result;
166 }
167
168 static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
169 {
170 int i;
171 for (i = 0; i < 20; i++) {
172 static char hex[] = "0123456789abcdef";
173 unsigned int val = sha1[i];
174 strbuf_addch(buf, hex[val >> 4]);
175 strbuf_addch(buf, hex[val & 0xf]);
176 if (!i)
177 strbuf_addch(buf, '/');
178 }
179 }
180
181 const char *sha1_file_name(const unsigned char *sha1)
182 {
183 static struct strbuf buf = STRBUF_INIT;
184
185 strbuf_reset(&buf);
186 strbuf_addf(&buf, "%s/", get_object_directory());
187
188 fill_sha1_path(&buf, sha1);
189 return buf.buf;
190 }
191
192 struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
193 {
194 strbuf_setlen(&alt->scratch, alt->base_len);
195 return &alt->scratch;
196 }
197
198 static const char *alt_sha1_path(struct alternate_object_database *alt,
199 const unsigned char *sha1)
200 {
201 struct strbuf *buf = alt_scratch_buf(alt);
202 fill_sha1_path(buf, sha1);
203 return buf->buf;
204 }
205
206 /*
207 * Return the name of the pack or index file with the specified sha1
208 * in its filename. *base and *name are scratch space that must be
209 * provided by the caller. which should be "pack" or "idx".
210 */
211 static char *sha1_get_pack_name(const unsigned char *sha1,
212 struct strbuf *buf,
213 const char *which)
214 {
215 strbuf_reset(buf);
216 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
217 sha1_to_hex(sha1), which);
218 return buf->buf;
219 }
220
221 char *sha1_pack_name(const unsigned char *sha1)
222 {
223 static struct strbuf buf = STRBUF_INIT;
224 return sha1_get_pack_name(sha1, &buf, "pack");
225 }
226
227 char *sha1_pack_index_name(const unsigned char *sha1)
228 {
229 static struct strbuf buf = STRBUF_INIT;
230 return sha1_get_pack_name(sha1, &buf, "idx");
231 }
232
233 struct alternate_object_database *alt_odb_list;
234 static struct alternate_object_database **alt_odb_tail;
235
236 /*
237 * Return non-zero iff the path is usable as an alternate object database.
238 */
239 static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
240 {
241 struct alternate_object_database *alt;
242
243 /* Detect cases where alternate disappeared */
244 if (!is_directory(path->buf)) {
245 error("object directory %s does not exist; "
246 "check .git/objects/info/alternates.",
247 path->buf);
248 return 0;
249 }
250
251 /*
252 * Prevent the common mistake of listing the same
253 * thing twice, or object directory itself.
254 */
255 for (alt = alt_odb_list; alt; alt = alt->next) {
256 if (!fspathcmp(path->buf, alt->path))
257 return 0;
258 }
259 if (!fspathcmp(path->buf, normalized_objdir))
260 return 0;
261
262 return 1;
263 }
264
265 /*
266 * Prepare alternate object database registry.
267 *
268 * The variable alt_odb_list points at the list of struct
269 * alternate_object_database. The elements on this list come from
270 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
271 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
272 * whose contents is similar to that environment variable but can be
273 * LF separated. Its base points at a statically allocated buffer that
274 * contains "/the/directory/corresponding/to/.git/objects/...", while
275 * its name points just after the slash at the end of ".git/objects/"
276 * in the example above, and has enough space to hold 40-byte hex
277 * SHA1, an extra slash for the first level indirection, and the
278 * terminating NUL.
279 */
280 static int link_alt_odb_entry(const char *entry, const char *relative_base,
281 int depth, const char *normalized_objdir)
282 {
283 struct alternate_object_database *ent;
284 struct strbuf pathbuf = STRBUF_INIT;
285
286 if (!is_absolute_path(entry) && relative_base) {
287 strbuf_realpath(&pathbuf, relative_base, 1);
288 strbuf_addch(&pathbuf, '/');
289 }
290 strbuf_addstr(&pathbuf, entry);
291
292 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
293 error("unable to normalize alternate object path: %s",
294 pathbuf.buf);
295 strbuf_release(&pathbuf);
296 return -1;
297 }
298
299 /*
300 * The trailing slash after the directory name is given by
301 * this function at the end. Remove duplicates.
302 */
303 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
304 strbuf_setlen(&pathbuf, pathbuf.len - 1);
305
306 if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
307 strbuf_release(&pathbuf);
308 return -1;
309 }
310
311 ent = alloc_alt_odb(pathbuf.buf);
312
313 /* add the alternate entry */
314 *alt_odb_tail = ent;
315 alt_odb_tail = &(ent->next);
316 ent->next = NULL;
317
318 /* recursively add alternates */
319 read_info_alternates(pathbuf.buf, depth + 1);
320
321 strbuf_release(&pathbuf);
322 return 0;
323 }
324
325 static const char *parse_alt_odb_entry(const char *string,
326 int sep,
327 struct strbuf *out)
328 {
329 const char *end;
330
331 strbuf_reset(out);
332
333 if (*string == '#') {
334 /* comment; consume up to next separator */
335 end = strchrnul(string, sep);
336 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
337 /*
338 * quoted path; unquote_c_style has copied the
339 * data for us and set "end". Broken quoting (e.g.,
340 * an entry that doesn't end with a quote) falls
341 * back to the unquoted case below.
342 */
343 } else {
344 /* normal, unquoted path */
345 end = strchrnul(string, sep);
346 strbuf_add(out, string, end - string);
347 }
348
349 if (*end)
350 end++;
351 return end;
352 }
353
354 static void link_alt_odb_entries(const char *alt, int len, int sep,
355 const char *relative_base, int depth)
356 {
357 struct strbuf objdirbuf = STRBUF_INIT;
358 struct strbuf entry = STRBUF_INIT;
359
360 if (depth > 5) {
361 error("%s: ignoring alternate object stores, nesting too deep.",
362 relative_base);
363 return;
364 }
365
366 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
367 if (strbuf_normalize_path(&objdirbuf) < 0)
368 die("unable to normalize object directory: %s",
369 objdirbuf.buf);
370
371 while (*alt) {
372 alt = parse_alt_odb_entry(alt, sep, &entry);
373 if (!entry.len)
374 continue;
375 link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
376 }
377 strbuf_release(&entry);
378 strbuf_release(&objdirbuf);
379 }
380
381 void read_info_alternates(const char * relative_base, int depth)
382 {
383 char *map;
384 size_t mapsz;
385 struct stat st;
386 char *path;
387 int fd;
388
389 path = xstrfmt("%s/info/alternates", relative_base);
390 fd = git_open(path);
391 free(path);
392 if (fd < 0)
393 return;
394 if (fstat(fd, &st) || (st.st_size == 0)) {
395 close(fd);
396 return;
397 }
398 mapsz = xsize_t(st.st_size);
399 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
400 close(fd);
401
402 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
403
404 munmap(map, mapsz);
405 }
406
407 struct alternate_object_database *alloc_alt_odb(const char *dir)
408 {
409 struct alternate_object_database *ent;
410
411 FLEX_ALLOC_STR(ent, path, dir);
412 strbuf_init(&ent->scratch, 0);
413 strbuf_addf(&ent->scratch, "%s/", dir);
414 ent->base_len = ent->scratch.len;
415
416 return ent;
417 }
418
419 void add_to_alternates_file(const char *reference)
420 {
421 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
422 char *alts = git_pathdup("objects/info/alternates");
423 FILE *in, *out;
424
425 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
426 out = fdopen_lock_file(lock, "w");
427 if (!out)
428 die_errno("unable to fdopen alternates lockfile");
429
430 in = fopen(alts, "r");
431 if (in) {
432 struct strbuf line = STRBUF_INIT;
433 int found = 0;
434
435 while (strbuf_getline(&line, in) != EOF) {
436 if (!strcmp(reference, line.buf)) {
437 found = 1;
438 break;
439 }
440 fprintf_or_die(out, "%s\n", line.buf);
441 }
442
443 strbuf_release(&line);
444 fclose(in);
445
446 if (found) {
447 rollback_lock_file(lock);
448 lock = NULL;
449 }
450 }
451 else if (errno != ENOENT)
452 die_errno("unable to read alternates file");
453
454 if (lock) {
455 fprintf_or_die(out, "%s\n", reference);
456 if (commit_lock_file(lock))
457 die_errno("unable to move new alternates file into place");
458 if (alt_odb_tail)
459 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
460 }
461 free(alts);
462 }
463
464 void add_to_alternates_memory(const char *reference)
465 {
466 /*
467 * Make sure alternates are initialized, or else our entry may be
468 * overwritten when they are.
469 */
470 prepare_alt_odb();
471
472 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
473 }
474
475 /*
476 * Compute the exact path an alternate is at and returns it. In case of
477 * error NULL is returned and the human readable error is added to `err`
478 * `path` may be relative and should point to $GITDIR.
479 * `err` must not be null.
480 */
481 char *compute_alternate_path(const char *path, struct strbuf *err)
482 {
483 char *ref_git = NULL;
484 const char *repo, *ref_git_s;
485 int seen_error = 0;
486
487 ref_git_s = real_path_if_valid(path);
488 if (!ref_git_s) {
489 seen_error = 1;
490 strbuf_addf(err, _("path '%s' does not exist"), path);
491 goto out;
492 } else
493 /*
494 * Beware: read_gitfile(), real_path() and mkpath()
495 * return static buffer
496 */
497 ref_git = xstrdup(ref_git_s);
498
499 repo = read_gitfile(ref_git);
500 if (!repo)
501 repo = read_gitfile(mkpath("%s/.git", ref_git));
502 if (repo) {
503 free(ref_git);
504 ref_git = xstrdup(repo);
505 }
506
507 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
508 char *ref_git_git = mkpathdup("%s/.git", ref_git);
509 free(ref_git);
510 ref_git = ref_git_git;
511 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
512 struct strbuf sb = STRBUF_INIT;
513 seen_error = 1;
514 if (get_common_dir(&sb, ref_git)) {
515 strbuf_addf(err,
516 _("reference repository '%s' as a linked "
517 "checkout is not supported yet."),
518 path);
519 goto out;
520 }
521
522 strbuf_addf(err, _("reference repository '%s' is not a "
523 "local repository."), path);
524 goto out;
525 }
526
527 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
528 strbuf_addf(err, _("reference repository '%s' is shallow"),
529 path);
530 seen_error = 1;
531 goto out;
532 }
533
534 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
535 strbuf_addf(err,
536 _("reference repository '%s' is grafted"),
537 path);
538 seen_error = 1;
539 goto out;
540 }
541
542 out:
543 if (seen_error) {
544 free(ref_git);
545 ref_git = NULL;
546 }
547
548 return ref_git;
549 }
550
551 int foreach_alt_odb(alt_odb_fn fn, void *cb)
552 {
553 struct alternate_object_database *ent;
554 int r = 0;
555
556 prepare_alt_odb();
557 for (ent = alt_odb_list; ent; ent = ent->next) {
558 r = fn(ent, cb);
559 if (r)
560 break;
561 }
562 return r;
563 }
564
565 void prepare_alt_odb(void)
566 {
567 const char *alt;
568
569 if (alt_odb_tail)
570 return;
571
572 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
573 if (!alt) alt = "";
574
575 alt_odb_tail = &alt_odb_list;
576 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
577
578 read_info_alternates(get_object_directory(), 0);
579 }
580
581 /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
582 static int freshen_file(const char *fn)
583 {
584 struct utimbuf t;
585 t.actime = t.modtime = time(NULL);
586 return !utime(fn, &t);
587 }
588
589 /*
590 * All of the check_and_freshen functions return 1 if the file exists and was
591 * freshened (if freshening was requested), 0 otherwise. If they return
592 * 0, you should not assume that it is safe to skip a write of the object (it
593 * either does not exist on disk, or has a stale mtime and may be subject to
594 * pruning).
595 */
596 static int check_and_freshen_file(const char *fn, int freshen)
597 {
598 if (access(fn, F_OK))
599 return 0;
600 if (freshen && !freshen_file(fn))
601 return 0;
602 return 1;
603 }
604
605 static int check_and_freshen_local(const unsigned char *sha1, int freshen)
606 {
607 return check_and_freshen_file(sha1_file_name(sha1), freshen);
608 }
609
610 static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
611 {
612 struct alternate_object_database *alt;
613 prepare_alt_odb();
614 for (alt = alt_odb_list; alt; alt = alt->next) {
615 const char *path = alt_sha1_path(alt, sha1);
616 if (check_and_freshen_file(path, freshen))
617 return 1;
618 }
619 return 0;
620 }
621
622 static int check_and_freshen(const unsigned char *sha1, int freshen)
623 {
624 return check_and_freshen_local(sha1, freshen) ||
625 check_and_freshen_nonlocal(sha1, freshen);
626 }
627
628 int has_loose_object_nonlocal(const unsigned char *sha1)
629 {
630 return check_and_freshen_nonlocal(sha1, 0);
631 }
632
633 static int has_loose_object(const unsigned char *sha1)
634 {
635 return check_and_freshen(sha1, 0);
636 }
637
638 static unsigned int pack_used_ctr;
639 static unsigned int pack_mmap_calls;
640 static unsigned int peak_pack_open_windows;
641 static unsigned int pack_open_windows;
642 static unsigned int pack_open_fds;
643 static unsigned int pack_max_fds;
644 static size_t peak_pack_mapped;
645 static size_t pack_mapped;
646 struct packed_git *packed_git;
647
648 static struct mru packed_git_mru_storage;
649 struct mru *packed_git_mru = &packed_git_mru_storage;
650
651 void pack_report(void)
652 {
653 fprintf(stderr,
654 "pack_report: getpagesize() = %10" SZ_FMT "\n"
655 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
656 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
657 sz_fmt(getpagesize()),
658 sz_fmt(packed_git_window_size),
659 sz_fmt(packed_git_limit));
660 fprintf(stderr,
661 "pack_report: pack_used_ctr = %10u\n"
662 "pack_report: pack_mmap_calls = %10u\n"
663 "pack_report: pack_open_windows = %10u / %10u\n"
664 "pack_report: pack_mapped = "
665 "%10" SZ_FMT " / %10" SZ_FMT "\n",
666 pack_used_ctr,
667 pack_mmap_calls,
668 pack_open_windows, peak_pack_open_windows,
669 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
670 }
671
672 /*
673 * Open and mmap the index file at path, perform a couple of
674 * consistency checks, then record its information to p. Return 0 on
675 * success.
676 */
677 static int check_packed_git_idx(const char *path, struct packed_git *p)
678 {
679 void *idx_map;
680 struct pack_idx_header *hdr;
681 size_t idx_size;
682 uint32_t version, nr, i, *index;
683 int fd = git_open(path);
684 struct stat st;
685
686 if (fd < 0)
687 return -1;
688 if (fstat(fd, &st)) {
689 close(fd);
690 return -1;
691 }
692 idx_size = xsize_t(st.st_size);
693 if (idx_size < 4 * 256 + 20 + 20) {
694 close(fd);
695 return error("index file %s is too small", path);
696 }
697 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
698 close(fd);
699
700 hdr = idx_map;
701 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
702 version = ntohl(hdr->idx_version);
703 if (version < 2 || version > 2) {
704 munmap(idx_map, idx_size);
705 return error("index file %s is version %"PRIu32
706 " and is not supported by this binary"
707 " (try upgrading GIT to a newer version)",
708 path, version);
709 }
710 } else
711 version = 1;
712
713 nr = 0;
714 index = idx_map;
715 if (version > 1)
716 index += 2; /* skip index header */
717 for (i = 0; i < 256; i++) {
718 uint32_t n = ntohl(index[i]);
719 if (n < nr) {
720 munmap(idx_map, idx_size);
721 return error("non-monotonic index %s", path);
722 }
723 nr = n;
724 }
725
726 if (version == 1) {
727 /*
728 * Total size:
729 * - 256 index entries 4 bytes each
730 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
731 * - 20-byte SHA1 of the packfile
732 * - 20-byte SHA1 file checksum
733 */
734 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
735 munmap(idx_map, idx_size);
736 return error("wrong index v1 file size in %s", path);
737 }
738 } else if (version == 2) {
739 /*
740 * Minimum size:
741 * - 8 bytes of header
742 * - 256 index entries 4 bytes each
743 * - 20-byte sha1 entry * nr
744 * - 4-byte crc entry * nr
745 * - 4-byte offset entry * nr
746 * - 20-byte SHA1 of the packfile
747 * - 20-byte SHA1 file checksum
748 * And after the 4-byte offset table might be a
749 * variable sized table containing 8-byte entries
750 * for offsets larger than 2^31.
751 */
752 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
753 unsigned long max_size = min_size;
754 if (nr)
755 max_size += (nr - 1)*8;
756 if (idx_size < min_size || idx_size > max_size) {
757 munmap(idx_map, idx_size);
758 return error("wrong index v2 file size in %s", path);
759 }
760 if (idx_size != min_size &&
761 /*
762 * make sure we can deal with large pack offsets.
763 * 31-bit signed offset won't be enough, neither
764 * 32-bit unsigned one will be.
765 */
766 (sizeof(off_t) <= 4)) {
767 munmap(idx_map, idx_size);
768 return error("pack too large for current definition of off_t in %s", path);
769 }
770 }
771
772 p->index_version = version;
773 p->index_data = idx_map;
774 p->index_size = idx_size;
775 p->num_objects = nr;
776 return 0;
777 }
778
779 int open_pack_index(struct packed_git *p)
780 {
781 char *idx_name;
782 size_t len;
783 int ret;
784
785 if (p->index_data)
786 return 0;
787
788 if (!strip_suffix(p->pack_name, ".pack", &len))
789 die("BUG: pack_name does not end in .pack");
790 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
791 ret = check_packed_git_idx(idx_name, p);
792 free(idx_name);
793 return ret;
794 }
795
796 static void scan_windows(struct packed_git *p,
797 struct packed_git **lru_p,
798 struct pack_window **lru_w,
799 struct pack_window **lru_l)
800 {
801 struct pack_window *w, *w_l;
802
803 for (w_l = NULL, w = p->windows; w; w = w->next) {
804 if (!w->inuse_cnt) {
805 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
806 *lru_p = p;
807 *lru_w = w;
808 *lru_l = w_l;
809 }
810 }
811 w_l = w;
812 }
813 }
814
815 static int unuse_one_window(struct packed_git *current)
816 {
817 struct packed_git *p, *lru_p = NULL;
818 struct pack_window *lru_w = NULL, *lru_l = NULL;
819
820 if (current)
821 scan_windows(current, &lru_p, &lru_w, &lru_l);
822 for (p = packed_git; p; p = p->next)
823 scan_windows(p, &lru_p, &lru_w, &lru_l);
824 if (lru_p) {
825 munmap(lru_w->base, lru_w->len);
826 pack_mapped -= lru_w->len;
827 if (lru_l)
828 lru_l->next = lru_w->next;
829 else
830 lru_p->windows = lru_w->next;
831 free(lru_w);
832 pack_open_windows--;
833 return 1;
834 }
835 return 0;
836 }
837
838 void release_pack_memory(size_t need)
839 {
840 size_t cur = pack_mapped;
841 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
842 ; /* nothing */
843 }
844
845 static void mmap_limit_check(size_t length)
846 {
847 static size_t limit = 0;
848 if (!limit) {
849 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
850 if (!limit)
851 limit = SIZE_MAX;
852 }
853 if (length > limit)
854 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
855 (uintmax_t)length, (uintmax_t)limit);
856 }
857
858 void *xmmap_gently(void *start, size_t length,
859 int prot, int flags, int fd, off_t offset)
860 {
861 void *ret;
862
863 mmap_limit_check(length);
864 ret = mmap(start, length, prot, flags, fd, offset);
865 if (ret == MAP_FAILED) {
866 if (!length)
867 return NULL;
868 release_pack_memory(length);
869 ret = mmap(start, length, prot, flags, fd, offset);
870 }
871 return ret;
872 }
873
874 void *xmmap(void *start, size_t length,
875 int prot, int flags, int fd, off_t offset)
876 {
877 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
878 if (ret == MAP_FAILED)
879 die_errno("mmap failed");
880 return ret;
881 }
882
883 void close_pack_windows(struct packed_git *p)
884 {
885 while (p->windows) {
886 struct pack_window *w = p->windows;
887
888 if (w->inuse_cnt)
889 die("pack '%s' still has open windows to it",
890 p->pack_name);
891 munmap(w->base, w->len);
892 pack_mapped -= w->len;
893 pack_open_windows--;
894 p->windows = w->next;
895 free(w);
896 }
897 }
898
899 static int close_pack_fd(struct packed_git *p)
900 {
901 if (p->pack_fd < 0)
902 return 0;
903
904 close(p->pack_fd);
905 pack_open_fds--;
906 p->pack_fd = -1;
907
908 return 1;
909 }
910
911 static void close_pack(struct packed_git *p)
912 {
913 close_pack_windows(p);
914 close_pack_fd(p);
915 close_pack_index(p);
916 }
917
918 void close_all_packs(void)
919 {
920 struct packed_git *p;
921
922 for (p = packed_git; p; p = p->next)
923 if (p->do_not_close)
924 die("BUG: want to close pack marked 'do-not-close'");
925 else
926 close_pack(p);
927 }
928
929
930 /*
931 * The LRU pack is the one with the oldest MRU window, preferring packs
932 * with no used windows, or the oldest mtime if it has no windows allocated.
933 */
934 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
935 {
936 struct pack_window *w, *this_mru_w;
937 int has_windows_inuse = 0;
938
939 /*
940 * Reject this pack if it has windows and the previously selected
941 * one does not. If this pack does not have windows, reject
942 * it if the pack file is newer than the previously selected one.
943 */
944 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
945 return;
946
947 for (w = this_mru_w = p->windows; w; w = w->next) {
948 /*
949 * Reject this pack if any of its windows are in use,
950 * but the previously selected pack did not have any
951 * inuse windows. Otherwise, record that this pack
952 * has windows in use.
953 */
954 if (w->inuse_cnt) {
955 if (*accept_windows_inuse)
956 has_windows_inuse = 1;
957 else
958 return;
959 }
960
961 if (w->last_used > this_mru_w->last_used)
962 this_mru_w = w;
963
964 /*
965 * Reject this pack if it has windows that have been
966 * used more recently than the previously selected pack.
967 * If the previously selected pack had windows inuse and
968 * we have not encountered a window in this pack that is
969 * inuse, skip this check since we prefer a pack with no
970 * inuse windows to one that has inuse windows.
971 */
972 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
973 this_mru_w->last_used > (*mru_w)->last_used)
974 return;
975 }
976
977 /*
978 * Select this pack.
979 */
980 *mru_w = this_mru_w;
981 *lru_p = p;
982 *accept_windows_inuse = has_windows_inuse;
983 }
984
985 static int close_one_pack(void)
986 {
987 struct packed_git *p, *lru_p = NULL;
988 struct pack_window *mru_w = NULL;
989 int accept_windows_inuse = 1;
990
991 for (p = packed_git; p; p = p->next) {
992 if (p->pack_fd == -1)
993 continue;
994 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
995 }
996
997 if (lru_p)
998 return close_pack_fd(lru_p);
999
1000 return 0;
1001 }
1002
1003 void unuse_pack(struct pack_window **w_cursor)
1004 {
1005 struct pack_window *w = *w_cursor;
1006 if (w) {
1007 w->inuse_cnt--;
1008 *w_cursor = NULL;
1009 }
1010 }
1011
1012 void close_pack_index(struct packed_git *p)
1013 {
1014 if (p->index_data) {
1015 munmap((void *)p->index_data, p->index_size);
1016 p->index_data = NULL;
1017 }
1018 }
1019
1020 static unsigned int get_max_fd_limit(void)
1021 {
1022 #ifdef RLIMIT_NOFILE
1023 {
1024 struct rlimit lim;
1025
1026 if (!getrlimit(RLIMIT_NOFILE, &lim))
1027 return lim.rlim_cur;
1028 }
1029 #endif
1030
1031 #ifdef _SC_OPEN_MAX
1032 {
1033 long open_max = sysconf(_SC_OPEN_MAX);
1034 if (0 < open_max)
1035 return open_max;
1036 /*
1037 * Otherwise, we got -1 for one of the two
1038 * reasons:
1039 *
1040 * (1) sysconf() did not understand _SC_OPEN_MAX
1041 * and signaled an error with -1; or
1042 * (2) sysconf() said there is no limit.
1043 *
1044 * We _could_ clear errno before calling sysconf() to
1045 * tell these two cases apart and return a huge number
1046 * in the latter case to let the caller cap it to a
1047 * value that is not so selfish, but letting the
1048 * fallback OPEN_MAX codepath take care of these cases
1049 * is a lot simpler.
1050 */
1051 }
1052 #endif
1053
1054 #ifdef OPEN_MAX
1055 return OPEN_MAX;
1056 #else
1057 return 1; /* see the caller ;-) */
1058 #endif
1059 }
1060
1061 /*
1062 * Do not call this directly as this leaks p->pack_fd on error return;
1063 * call open_packed_git() instead.
1064 */
1065 static int open_packed_git_1(struct packed_git *p)
1066 {
1067 struct stat st;
1068 struct pack_header hdr;
1069 unsigned char sha1[20];
1070 unsigned char *idx_sha1;
1071 long fd_flag;
1072
1073 if (!p->index_data && open_pack_index(p))
1074 return error("packfile %s index unavailable", p->pack_name);
1075
1076 if (!pack_max_fds) {
1077 unsigned int max_fds = get_max_fd_limit();
1078
1079 /* Save 3 for stdin/stdout/stderr, 22 for work */
1080 if (25 < max_fds)
1081 pack_max_fds = max_fds - 25;
1082 else
1083 pack_max_fds = 1;
1084 }
1085
1086 while (pack_max_fds <= pack_open_fds && close_one_pack())
1087 ; /* nothing */
1088
1089 p->pack_fd = git_open(p->pack_name);
1090 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
1091 return -1;
1092 pack_open_fds++;
1093
1094 /* If we created the struct before we had the pack we lack size. */
1095 if (!p->pack_size) {
1096 if (!S_ISREG(st.st_mode))
1097 return error("packfile %s not a regular file", p->pack_name);
1098 p->pack_size = st.st_size;
1099 } else if (p->pack_size != st.st_size)
1100 return error("packfile %s size changed", p->pack_name);
1101
1102 /* We leave these file descriptors open with sliding mmap;
1103 * there is no point keeping them open across exec(), though.
1104 */
1105 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
1106 if (fd_flag < 0)
1107 return error("cannot determine file descriptor flags");
1108 fd_flag |= FD_CLOEXEC;
1109 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
1110 return error("cannot set FD_CLOEXEC");
1111
1112 /* Verify we recognize this pack file format. */
1113 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
1114 return error("file %s is far too short to be a packfile", p->pack_name);
1115 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
1116 return error("file %s is not a GIT packfile", p->pack_name);
1117 if (!pack_version_ok(hdr.hdr_version))
1118 return error("packfile %s is version %"PRIu32" and not"
1119 " supported (try upgrading GIT to a newer version)",
1120 p->pack_name, ntohl(hdr.hdr_version));
1121
1122 /* Verify the pack matches its index. */
1123 if (p->num_objects != ntohl(hdr.hdr_entries))
1124 return error("packfile %s claims to have %"PRIu32" objects"
1125 " while index indicates %"PRIu32" objects",
1126 p->pack_name, ntohl(hdr.hdr_entries),
1127 p->num_objects);
1128 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
1129 return error("end of packfile %s is unavailable", p->pack_name);
1130 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
1131 return error("packfile %s signature is unavailable", p->pack_name);
1132 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
1133 if (hashcmp(sha1, idx_sha1))
1134 return error("packfile %s does not match index", p->pack_name);
1135 return 0;
1136 }
1137
1138 static int open_packed_git(struct packed_git *p)
1139 {
1140 if (!open_packed_git_1(p))
1141 return 0;
1142 close_pack_fd(p);
1143 return -1;
1144 }
1145
1146 static int in_window(struct pack_window *win, off_t offset)
1147 {
1148 /* We must promise at least 20 bytes (one hash) after the
1149 * offset is available from this window, otherwise the offset
1150 * is not actually in this window and a different window (which
1151 * has that one hash excess) must be used. This is to support
1152 * the object header and delta base parsing routines below.
1153 */
1154 off_t win_off = win->offset;
1155 return win_off <= offset
1156 && (offset + 20) <= (win_off + win->len);
1157 }
1158
1159 unsigned char *use_pack(struct packed_git *p,
1160 struct pack_window **w_cursor,
1161 off_t offset,
1162 unsigned long *left)
1163 {
1164 struct pack_window *win = *w_cursor;
1165
1166 /* Since packfiles end in a hash of their content and it's
1167 * pointless to ask for an offset into the middle of that
1168 * hash, and the in_window function above wouldn't match
1169 * don't allow an offset too close to the end of the file.
1170 */
1171 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1172 die("packfile %s cannot be accessed", p->pack_name);
1173 if (offset > (p->pack_size - 20))
1174 die("offset beyond end of packfile (truncated pack?)");
1175 if (offset < 0)
1176 die(_("offset before end of packfile (broken .idx?)"));
1177
1178 if (!win || !in_window(win, offset)) {
1179 if (win)
1180 win->inuse_cnt--;
1181 for (win = p->windows; win; win = win->next) {
1182 if (in_window(win, offset))
1183 break;
1184 }
1185 if (!win) {
1186 size_t window_align = packed_git_window_size / 2;
1187 off_t len;
1188
1189 if (p->pack_fd == -1 && open_packed_git(p))
1190 die("packfile %s cannot be accessed", p->pack_name);
1191
1192 win = xcalloc(1, sizeof(*win));
1193 win->offset = (offset / window_align) * window_align;
1194 len = p->pack_size - win->offset;
1195 if (len > packed_git_window_size)
1196 len = packed_git_window_size;
1197 win->len = (size_t)len;
1198 pack_mapped += win->len;
1199 while (packed_git_limit < pack_mapped
1200 && unuse_one_window(p))
1201 ; /* nothing */
1202 win->base = xmmap(NULL, win->len,
1203 PROT_READ, MAP_PRIVATE,
1204 p->pack_fd, win->offset);
1205 if (win->base == MAP_FAILED)
1206 die_errno("packfile %s cannot be mapped",
1207 p->pack_name);
1208 if (!win->offset && win->len == p->pack_size
1209 && !p->do_not_close)
1210 close_pack_fd(p);
1211 pack_mmap_calls++;
1212 pack_open_windows++;
1213 if (pack_mapped > peak_pack_mapped)
1214 peak_pack_mapped = pack_mapped;
1215 if (pack_open_windows > peak_pack_open_windows)
1216 peak_pack_open_windows = pack_open_windows;
1217 win->next = p->windows;
1218 p->windows = win;
1219 }
1220 }
1221 if (win != *w_cursor) {
1222 win->last_used = pack_used_ctr++;
1223 win->inuse_cnt++;
1224 *w_cursor = win;
1225 }
1226 offset -= win->offset;
1227 if (left)
1228 *left = win->len - xsize_t(offset);
1229 return win->base + offset;
1230 }
1231
1232 static struct packed_git *alloc_packed_git(int extra)
1233 {
1234 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
1235 memset(p, 0, sizeof(*p));
1236 p->pack_fd = -1;
1237 return p;
1238 }
1239
1240 static void try_to_free_pack_memory(size_t size)
1241 {
1242 release_pack_memory(size);
1243 }
1244
1245 struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1246 {
1247 static int have_set_try_to_free_routine;
1248 struct stat st;
1249 size_t alloc;
1250 struct packed_git *p;
1251
1252 if (!have_set_try_to_free_routine) {
1253 have_set_try_to_free_routine = 1;
1254 set_try_to_free_routine(try_to_free_pack_memory);
1255 }
1256
1257 /*
1258 * Make sure a corresponding .pack file exists and that
1259 * the index looks sane.
1260 */
1261 if (!strip_suffix_mem(path, &path_len, ".idx"))
1262 return NULL;
1263
1264 /*
1265 * ".pack" is long enough to hold any suffix we're adding (and
1266 * the use xsnprintf double-checks that)
1267 */
1268 alloc = st_add3(path_len, strlen(".pack"), 1);
1269 p = alloc_packed_git(alloc);
1270 memcpy(p->pack_name, path, path_len);
1271
1272 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
1273 if (!access(p->pack_name, F_OK))
1274 p->pack_keep = 1;
1275
1276 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
1277 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
1278 free(p);
1279 return NULL;
1280 }
1281
1282 /* ok, it looks sane as far as we can check without
1283 * actually mapping the pack file.
1284 */
1285 p->pack_size = st.st_size;
1286 p->pack_local = local;
1287 p->mtime = st.st_mtime;
1288 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1289 hashclr(p->sha1);
1290 return p;
1291 }
1292
1293 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
1294 {
1295 const char *path = sha1_pack_name(sha1);
1296 size_t alloc = st_add(strlen(path), 1);
1297 struct packed_git *p = alloc_packed_git(alloc);
1298
1299 memcpy(p->pack_name, path, alloc); /* includes NUL */
1300 hashcpy(p->sha1, sha1);
1301 if (check_packed_git_idx(idx_path, p)) {
1302 free(p);
1303 return NULL;
1304 }
1305
1306 return p;
1307 }
1308
1309 void install_packed_git(struct packed_git *pack)
1310 {
1311 if (pack->pack_fd != -1)
1312 pack_open_fds++;
1313
1314 pack->next = packed_git;
1315 packed_git = pack;
1316 }
1317
1318 void (*report_garbage)(unsigned seen_bits, const char *path);
1319
1320 static void report_helper(const struct string_list *list,
1321 int seen_bits, int first, int last)
1322 {
1323 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
1324 return;
1325
1326 for (; first < last; first++)
1327 report_garbage(seen_bits, list->items[first].string);
1328 }
1329
1330 static void report_pack_garbage(struct string_list *list)
1331 {
1332 int i, baselen = -1, first = 0, seen_bits = 0;
1333
1334 if (!report_garbage)
1335 return;
1336
1337 string_list_sort(list);
1338
1339 for (i = 0; i < list->nr; i++) {
1340 const char *path = list->items[i].string;
1341 if (baselen != -1 &&
1342 strncmp(path, list->items[first].string, baselen)) {
1343 report_helper(list, seen_bits, first, i);
1344 baselen = -1;
1345 seen_bits = 0;
1346 }
1347 if (baselen == -1) {
1348 const char *dot = strrchr(path, '.');
1349 if (!dot) {
1350 report_garbage(PACKDIR_FILE_GARBAGE, path);
1351 continue;
1352 }
1353 baselen = dot - path + 1;
1354 first = i;
1355 }
1356 if (!strcmp(path + baselen, "pack"))
1357 seen_bits |= 1;
1358 else if (!strcmp(path + baselen, "idx"))
1359 seen_bits |= 2;
1360 }
1361 report_helper(list, seen_bits, first, list->nr);
1362 }
1363
1364 static void prepare_packed_git_one(char *objdir, int local)
1365 {
1366 struct strbuf path = STRBUF_INIT;
1367 size_t dirnamelen;
1368 DIR *dir;
1369 struct dirent *de;
1370 struct string_list garbage = STRING_LIST_INIT_DUP;
1371
1372 strbuf_addstr(&path, objdir);
1373 strbuf_addstr(&path, "/pack");
1374 dir = opendir(path.buf);
1375 if (!dir) {
1376 if (errno != ENOENT)
1377 error_errno("unable to open object pack directory: %s",
1378 path.buf);
1379 strbuf_release(&path);
1380 return;
1381 }
1382 strbuf_addch(&path, '/');
1383 dirnamelen = path.len;
1384 while ((de = readdir(dir)) != NULL) {
1385 struct packed_git *p;
1386 size_t base_len;
1387
1388 if (is_dot_or_dotdot(de->d_name))
1389 continue;
1390
1391 strbuf_setlen(&path, dirnamelen);
1392 strbuf_addstr(&path, de->d_name);
1393
1394 base_len = path.len;
1395 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
1396 /* Don't reopen a pack we already have. */
1397 for (p = packed_git; p; p = p->next) {
1398 size_t len;
1399 if (strip_suffix(p->pack_name, ".pack", &len) &&
1400 len == base_len &&
1401 !memcmp(p->pack_name, path.buf, len))
1402 break;
1403 }
1404 if (p == NULL &&
1405 /*
1406 * See if it really is a valid .idx file with
1407 * corresponding .pack file that we can map.
1408 */
1409 (p = add_packed_git(path.buf, path.len, local)) != NULL)
1410 install_packed_git(p);
1411 }
1412
1413 if (!report_garbage)
1414 continue;
1415
1416 if (ends_with(de->d_name, ".idx") ||
1417 ends_with(de->d_name, ".pack") ||
1418 ends_with(de->d_name, ".bitmap") ||
1419 ends_with(de->d_name, ".keep"))
1420 string_list_append(&garbage, path.buf);
1421 else
1422 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1423 }
1424 closedir(dir);
1425 report_pack_garbage(&garbage);
1426 string_list_clear(&garbage, 0);
1427 strbuf_release(&path);
1428 }
1429
1430 static int approximate_object_count_valid;
1431
1432 /*
1433 * Give a fast, rough count of the number of objects in the repository. This
1434 * ignores loose objects completely. If you have a lot of them, then either
1435 * you should repack because your performance will be awful, or they are
1436 * all unreachable objects about to be pruned, in which case they're not really
1437 * interesting as a measure of repo size in the first place.
1438 */
1439 unsigned long approximate_object_count(void)
1440 {
1441 static unsigned long count;
1442 if (!approximate_object_count_valid) {
1443 struct packed_git *p;
1444
1445 prepare_packed_git();
1446 count = 0;
1447 for (p = packed_git; p; p = p->next) {
1448 if (open_pack_index(p))
1449 continue;
1450 count += p->num_objects;
1451 }
1452 }
1453 return count;
1454 }
1455
1456 static void *get_next_packed_git(const void *p)
1457 {
1458 return ((const struct packed_git *)p)->next;
1459 }
1460
1461 static void set_next_packed_git(void *p, void *next)
1462 {
1463 ((struct packed_git *)p)->next = next;
1464 }
1465
1466 static int sort_pack(const void *a_, const void *b_)
1467 {
1468 const struct packed_git *a = a_;
1469 const struct packed_git *b = b_;
1470 int st;
1471
1472 /*
1473 * Local packs tend to contain objects specific to our
1474 * variant of the project than remote ones. In addition,
1475 * remote ones could be on a network mounted filesystem.
1476 * Favor local ones for these reasons.
1477 */
1478 st = a->pack_local - b->pack_local;
1479 if (st)
1480 return -st;
1481
1482 /*
1483 * Younger packs tend to contain more recent objects,
1484 * and more recent objects tend to get accessed more
1485 * often.
1486 */
1487 if (a->mtime < b->mtime)
1488 return 1;
1489 else if (a->mtime == b->mtime)
1490 return 0;
1491 return -1;
1492 }
1493
1494 static void rearrange_packed_git(void)
1495 {
1496 packed_git = llist_mergesort(packed_git, get_next_packed_git,
1497 set_next_packed_git, sort_pack);
1498 }
1499
1500 static void prepare_packed_git_mru(void)
1501 {
1502 struct packed_git *p;
1503
1504 mru_clear(packed_git_mru);
1505 for (p = packed_git; p; p = p->next)
1506 mru_append(packed_git_mru, p);
1507 }
1508
1509 static int prepare_packed_git_run_once = 0;
1510 void prepare_packed_git(void)
1511 {
1512 struct alternate_object_database *alt;
1513
1514 if (prepare_packed_git_run_once)
1515 return;
1516 prepare_packed_git_one(get_object_directory(), 1);
1517 prepare_alt_odb();
1518 for (alt = alt_odb_list; alt; alt = alt->next)
1519 prepare_packed_git_one(alt->path, 0);
1520 rearrange_packed_git();
1521 prepare_packed_git_mru();
1522 prepare_packed_git_run_once = 1;
1523 }
1524
1525 void reprepare_packed_git(void)
1526 {
1527 approximate_object_count_valid = 0;
1528 prepare_packed_git_run_once = 0;
1529 prepare_packed_git();
1530 }
1531
1532 static void mark_bad_packed_object(struct packed_git *p,
1533 const unsigned char *sha1)
1534 {
1535 unsigned i;
1536 for (i = 0; i < p->num_bad_objects; i++)
1537 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
1538 return;
1539 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1540 st_mult(GIT_SHA1_RAWSZ,
1541 st_add(p->num_bad_objects, 1)));
1542 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
1543 p->num_bad_objects++;
1544 }
1545
1546 static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1547 {
1548 struct packed_git *p;
1549 unsigned i;
1550
1551 for (p = packed_git; p; p = p->next)
1552 for (i = 0; i < p->num_bad_objects; i++)
1553 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1554 return p;
1555 return NULL;
1556 }
1557
1558 /*
1559 * With an in-core object data in "map", rehash it to make sure the
1560 * object name actually matches "sha1" to detect object corruption.
1561 * With "map" == NULL, try reading the object named with "sha1" using
1562 * the streaming interface and rehash it to do the same.
1563 */
1564 int check_sha1_signature(const unsigned char *sha1, void *map,
1565 unsigned long size, const char *type)
1566 {
1567 unsigned char real_sha1[20];
1568 enum object_type obj_type;
1569 struct git_istream *st;
1570 git_SHA_CTX c;
1571 char hdr[32];
1572 int hdrlen;
1573
1574 if (map) {
1575 hash_sha1_file(map, size, type, real_sha1);
1576 return hashcmp(sha1, real_sha1) ? -1 : 0;
1577 }
1578
1579 st = open_istream(sha1, &obj_type, &size, NULL);
1580 if (!st)
1581 return -1;
1582
1583 /* Generate the header */
1584 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
1585
1586 /* Sha1.. */
1587 git_SHA1_Init(&c);
1588 git_SHA1_Update(&c, hdr, hdrlen);
1589 for (;;) {
1590 char buf[1024 * 16];
1591 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1592
1593 if (readlen < 0) {
1594 close_istream(st);
1595 return -1;
1596 }
1597 if (!readlen)
1598 break;
1599 git_SHA1_Update(&c, buf, readlen);
1600 }
1601 git_SHA1_Final(real_sha1, &c);
1602 close_istream(st);
1603 return hashcmp(sha1, real_sha1) ? -1 : 0;
1604 }
1605
1606 int git_open_cloexec(const char *name, int flags)
1607 {
1608 int fd;
1609 static int o_cloexec = O_CLOEXEC;
1610
1611 fd = open(name, flags | o_cloexec);
1612 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
1613 /* Try again w/o O_CLOEXEC: the kernel might not support it */
1614 o_cloexec &= ~O_CLOEXEC;
1615 fd = open(name, flags | o_cloexec);
1616 }
1617
1618 #if defined(F_GETFL) && defined(F_SETFL) && defined(FD_CLOEXEC)
1619 {
1620 static int fd_cloexec = FD_CLOEXEC;
1621
1622 if (!o_cloexec && 0 <= fd && fd_cloexec) {
1623 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
1624 int flags = fcntl(fd, F_GETFL);
1625 if (fcntl(fd, F_SETFL, flags | fd_cloexec))
1626 fd_cloexec = 0;
1627 }
1628 }
1629 #endif
1630 return fd;
1631 }
1632
1633 /*
1634 * Find "sha1" as a loose object in the local repository or in an alternate.
1635 * Returns 0 on success, negative on failure.
1636 *
1637 * The "path" out-parameter will give the path of the object we found (if any).
1638 * Note that it may point to static storage and is only valid until another
1639 * call to sha1_file_name(), etc.
1640 */
1641 static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
1642 const char **path)
1643 {
1644 struct alternate_object_database *alt;
1645
1646 *path = sha1_file_name(sha1);
1647 if (!lstat(*path, st))
1648 return 0;
1649
1650 prepare_alt_odb();
1651 errno = ENOENT;
1652 for (alt = alt_odb_list; alt; alt = alt->next) {
1653 *path = alt_sha1_path(alt, sha1);
1654 if (!lstat(*path, st))
1655 return 0;
1656 }
1657
1658 return -1;
1659 }
1660
1661 /*
1662 * Like stat_sha1_file(), but actually open the object and return the
1663 * descriptor. See the caveats on the "path" parameter above.
1664 */
1665 static int open_sha1_file(const unsigned char *sha1, const char **path)
1666 {
1667 int fd;
1668 struct alternate_object_database *alt;
1669 int most_interesting_errno;
1670
1671 *path = sha1_file_name(sha1);
1672 fd = git_open(*path);
1673 if (fd >= 0)
1674 return fd;
1675 most_interesting_errno = errno;
1676
1677 prepare_alt_odb();
1678 for (alt = alt_odb_list; alt; alt = alt->next) {
1679 *path = alt_sha1_path(alt, sha1);
1680 fd = git_open(*path);
1681 if (fd >= 0)
1682 return fd;
1683 if (most_interesting_errno == ENOENT)
1684 most_interesting_errno = errno;
1685 }
1686 errno = most_interesting_errno;
1687 return -1;
1688 }
1689
1690 /*
1691 * Map the loose object at "path" if it is not NULL, or the path found by
1692 * searching for a loose object named "sha1".
1693 */
1694 static void *map_sha1_file_1(const char *path,
1695 const unsigned char *sha1,
1696 unsigned long *size)
1697 {
1698 void *map;
1699 int fd;
1700
1701 if (path)
1702 fd = git_open(path);
1703 else
1704 fd = open_sha1_file(sha1, &path);
1705 map = NULL;
1706 if (fd >= 0) {
1707 struct stat st;
1708
1709 if (!fstat(fd, &st)) {
1710 *size = xsize_t(st.st_size);
1711 if (!*size) {
1712 /* mmap() is forbidden on empty files */
1713 error("object file %s is empty", path);
1714 return NULL;
1715 }
1716 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1717 }
1718 close(fd);
1719 }
1720 return map;
1721 }
1722
1723 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1724 {
1725 return map_sha1_file_1(NULL, sha1, size);
1726 }
1727
1728 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1729 unsigned long len, enum object_type *type, unsigned long *sizep)
1730 {
1731 unsigned shift;
1732 unsigned long size, c;
1733 unsigned long used = 0;
1734
1735 c = buf[used++];
1736 *type = (c >> 4) & 7;
1737 size = c & 15;
1738 shift = 4;
1739 while (c & 0x80) {
1740 if (len <= used || bitsizeof(long) <= shift) {
1741 error("bad object header");
1742 size = used = 0;
1743 break;
1744 }
1745 c = buf[used++];
1746 size += (c & 0x7f) << shift;
1747 shift += 7;
1748 }
1749 *sizep = size;
1750 return used;
1751 }
1752
1753 static int unpack_sha1_short_header(git_zstream *stream,
1754 unsigned char *map, unsigned long mapsize,
1755 void *buffer, unsigned long bufsiz)
1756 {
1757 /* Get the data stream */
1758 memset(stream, 0, sizeof(*stream));
1759 stream->next_in = map;
1760 stream->avail_in = mapsize;
1761 stream->next_out = buffer;
1762 stream->avail_out = bufsiz;
1763
1764 git_inflate_init(stream);
1765 return git_inflate(stream, 0);
1766 }
1767
1768 int unpack_sha1_header(git_zstream *stream,
1769 unsigned char *map, unsigned long mapsize,
1770 void *buffer, unsigned long bufsiz)
1771 {
1772 int status = unpack_sha1_short_header(stream, map, mapsize,
1773 buffer, bufsiz);
1774
1775 if (status < Z_OK)
1776 return status;
1777
1778 /* Make sure we have the terminating NUL */
1779 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1780 return -1;
1781 return 0;
1782 }
1783
1784 static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1785 unsigned long mapsize, void *buffer,
1786 unsigned long bufsiz, struct strbuf *header)
1787 {
1788 int status;
1789
1790 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
1791 if (status < Z_OK)
1792 return -1;
1793
1794 /*
1795 * Check if entire header is unpacked in the first iteration.
1796 */
1797 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1798 return 0;
1799
1800 /*
1801 * buffer[0..bufsiz] was not large enough. Copy the partial
1802 * result out to header, and then append the result of further
1803 * reading the stream.
1804 */
1805 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1806 stream->next_out = buffer;
1807 stream->avail_out = bufsiz;
1808
1809 do {
1810 status = git_inflate(stream, 0);
1811 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1812 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1813 return 0;
1814 stream->next_out = buffer;
1815 stream->avail_out = bufsiz;
1816 } while (status != Z_STREAM_END);
1817 return -1;
1818 }
1819
1820 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1821 {
1822 int bytes = strlen(buffer) + 1;
1823 unsigned char *buf = xmallocz(size);
1824 unsigned long n;
1825 int status = Z_OK;
1826
1827 n = stream->total_out - bytes;
1828 if (n > size)
1829 n = size;
1830 memcpy(buf, (char *) buffer + bytes, n);
1831 bytes = n;
1832 if (bytes <= size) {
1833 /*
1834 * The above condition must be (bytes <= size), not
1835 * (bytes < size). In other words, even though we
1836 * expect no more output and set avail_out to zero,
1837 * the input zlib stream may have bytes that express
1838 * "this concludes the stream", and we *do* want to
1839 * eat that input.
1840 *
1841 * Otherwise we would not be able to test that we
1842 * consumed all the input to reach the expected size;
1843 * we also want to check that zlib tells us that all
1844 * went well with status == Z_STREAM_END at the end.
1845 */
1846 stream->next_out = buf + bytes;
1847 stream->avail_out = size - bytes;
1848 while (status == Z_OK)
1849 status = git_inflate(stream, Z_FINISH);
1850 }
1851 if (status == Z_STREAM_END && !stream->avail_in) {
1852 git_inflate_end(stream);
1853 return buf;
1854 }
1855
1856 if (status < 0)
1857 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1858 else if (stream->avail_in)
1859 error("garbage at end of loose object '%s'",
1860 sha1_to_hex(sha1));
1861 free(buf);
1862 return NULL;
1863 }
1864
1865 /*
1866 * We used to just use "sscanf()", but that's actually way
1867 * too permissive for what we want to check. So do an anal
1868 * object header parse by hand.
1869 */
1870 static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1871 unsigned int flags)
1872 {
1873 const char *type_buf = hdr;
1874 unsigned long size;
1875 int type, type_len = 0;
1876
1877 /*
1878 * The type can be of any size but is followed by
1879 * a space.
1880 */
1881 for (;;) {
1882 char c = *hdr++;
1883 if (!c)
1884 return -1;
1885 if (c == ' ')
1886 break;
1887 type_len++;
1888 }
1889
1890 type = type_from_string_gently(type_buf, type_len, 1);
1891 if (oi->typename)
1892 strbuf_add(oi->typename, type_buf, type_len);
1893 /*
1894 * Set type to 0 if its an unknown object and
1895 * we're obtaining the type using '--allow-unknown-type'
1896 * option.
1897 */
1898 if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
1899 type = 0;
1900 else if (type < 0)
1901 die("invalid object type");
1902 if (oi->typep)
1903 *oi->typep = type;
1904
1905 /*
1906 * The length must follow immediately, and be in canonical
1907 * decimal format (ie "010" is not valid).
1908 */
1909 size = *hdr++ - '0';
1910 if (size > 9)
1911 return -1;
1912 if (size) {
1913 for (;;) {
1914 unsigned long c = *hdr - '0';
1915 if (c > 9)
1916 break;
1917 hdr++;
1918 size = size * 10 + c;
1919 }
1920 }
1921
1922 if (oi->sizep)
1923 *oi->sizep = size;
1924
1925 /*
1926 * The length must be followed by a zero byte
1927 */
1928 return *hdr ? -1 : type;
1929 }
1930
1931 int parse_sha1_header(const char *hdr, unsigned long *sizep)
1932 {
1933 struct object_info oi = OBJECT_INFO_INIT;
1934
1935 oi.sizep = sizep;
1936 return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
1937 }
1938
1939 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1940 {
1941 int ret;
1942 git_zstream stream;
1943 char hdr[8192];
1944
1945 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1946 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1947 return NULL;
1948
1949 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1950 }
1951
1952 unsigned long get_size_from_delta(struct packed_git *p,
1953 struct pack_window **w_curs,
1954 off_t curpos)
1955 {
1956 const unsigned char *data;
1957 unsigned char delta_head[20], *in;
1958 git_zstream stream;
1959 int st;
1960
1961 memset(&stream, 0, sizeof(stream));
1962 stream.next_out = delta_head;
1963 stream.avail_out = sizeof(delta_head);
1964
1965 git_inflate_init(&stream);
1966 do {
1967 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1968 stream.next_in = in;
1969 st = git_inflate(&stream, Z_FINISH);
1970 curpos += stream.next_in - in;
1971 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1972 stream.total_out < sizeof(delta_head));
1973 git_inflate_end(&stream);
1974 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1975 error("delta data unpack-initial failed");
1976 return 0;
1977 }
1978
1979 /* Examine the initial part of the delta to figure out
1980 * the result size.
1981 */
1982 data = delta_head;
1983
1984 /* ignore base size */
1985 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1986
1987 /* Read the result size */
1988 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1989 }
1990
1991 static off_t get_delta_base(struct packed_git *p,
1992 struct pack_window **w_curs,
1993 off_t *curpos,
1994 enum object_type type,
1995 off_t delta_obj_offset)
1996 {
1997 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1998 off_t base_offset;
1999
2000 /* use_pack() assured us we have [base_info, base_info + 20)
2001 * as a range that we can look at without walking off the
2002 * end of the mapped window. Its actually the hash size
2003 * that is assured. An OFS_DELTA longer than the hash size
2004 * is stupid, as then a REF_DELTA would be smaller to store.
2005 */
2006 if (type == OBJ_OFS_DELTA) {
2007 unsigned used = 0;
2008 unsigned char c = base_info[used++];
2009 base_offset = c & 127;
2010 while (c & 128) {
2011 base_offset += 1;
2012 if (!base_offset || MSB(base_offset, 7))
2013 return 0; /* overflow */
2014 c = base_info[used++];
2015 base_offset = (base_offset << 7) + (c & 127);
2016 }
2017 base_offset = delta_obj_offset - base_offset;
2018 if (base_offset <= 0 || base_offset >= delta_obj_offset)
2019 return 0; /* out of bound */
2020 *curpos += used;
2021 } else if (type == OBJ_REF_DELTA) {
2022 /* The base entry _must_ be in the same pack */
2023 base_offset = find_pack_entry_one(base_info, p);
2024 *curpos += 20;
2025 } else
2026 die("I am totally screwed");
2027 return base_offset;
2028 }
2029
2030 /*
2031 * Like get_delta_base above, but we return the sha1 instead of the pack
2032 * offset. This means it is cheaper for REF deltas (we do not have to do
2033 * the final object lookup), but more expensive for OFS deltas (we
2034 * have to load the revidx to convert the offset back into a sha1).
2035 */
2036 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
2037 struct pack_window **w_curs,
2038 off_t curpos,
2039 enum object_type type,
2040 off_t delta_obj_offset)
2041 {
2042 if (type == OBJ_REF_DELTA) {
2043 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
2044 return base;
2045 } else if (type == OBJ_OFS_DELTA) {
2046 struct revindex_entry *revidx;
2047 off_t base_offset = get_delta_base(p, w_curs, &curpos,
2048 type, delta_obj_offset);
2049
2050 if (!base_offset)
2051 return NULL;
2052
2053 revidx = find_pack_revindex(p, base_offset);
2054 if (!revidx)
2055 return NULL;
2056
2057 return nth_packed_object_sha1(p, revidx->nr);
2058 } else
2059 return NULL;
2060 }
2061
2062 int unpack_object_header(struct packed_git *p,
2063 struct pack_window **w_curs,
2064 off_t *curpos,
2065 unsigned long *sizep)
2066 {
2067 unsigned char *base;
2068 unsigned long left;
2069 unsigned long used;
2070 enum object_type type;
2071
2072 /* use_pack() assures us we have [base, base + 20) available
2073 * as a range that we can look at. (Its actually the hash
2074 * size that is assured.) With our object header encoding
2075 * the maximum deflated object size is 2^137, which is just
2076 * insane, so we know won't exceed what we have been given.
2077 */
2078 base = use_pack(p, w_curs, *curpos, &left);
2079 used = unpack_object_header_buffer(base, left, &type, sizep);
2080 if (!used) {
2081 type = OBJ_BAD;
2082 } else
2083 *curpos += used;
2084
2085 return type;
2086 }
2087
2088 static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
2089 {
2090 int type;
2091 struct revindex_entry *revidx;
2092 const unsigned char *sha1;
2093 revidx = find_pack_revindex(p, obj_offset);
2094 if (!revidx)
2095 return OBJ_BAD;
2096 sha1 = nth_packed_object_sha1(p, revidx->nr);
2097 mark_bad_packed_object(p, sha1);
2098 type = sha1_object_info(sha1, NULL);
2099 if (type <= OBJ_NONE)
2100 return OBJ_BAD;
2101 return type;
2102 }
2103
2104 #define POI_STACK_PREALLOC 64
2105
2106 static enum object_type packed_to_object_type(struct packed_git *p,
2107 off_t obj_offset,
2108 enum object_type type,
2109 struct pack_window **w_curs,
2110 off_t curpos)
2111 {
2112 off_t small_poi_stack[POI_STACK_PREALLOC];
2113 off_t *poi_stack = small_poi_stack;
2114 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
2115
2116 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2117 off_t base_offset;
2118 unsigned long size;
2119 /* Push the object we're going to leave behind */
2120 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
2121 poi_stack_alloc = alloc_nr(poi_stack_nr);
2122 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
2123 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
2124 } else {
2125 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
2126 }
2127 poi_stack[poi_stack_nr++] = obj_offset;
2128 /* If parsing the base offset fails, just unwind */
2129 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
2130 if (!base_offset)
2131 goto unwind;
2132 curpos = obj_offset = base_offset;
2133 type = unpack_object_header(p, w_curs, &curpos, &size);
2134 if (type <= OBJ_NONE) {
2135 /* If getting the base itself fails, we first
2136 * retry the base, otherwise unwind */
2137 type = retry_bad_packed_offset(p, base_offset);
2138 if (type > OBJ_NONE)
2139 goto out;
2140 goto unwind;
2141 }
2142 }
2143
2144 switch (type) {
2145 case OBJ_BAD:
2146 case OBJ_COMMIT:
2147 case OBJ_TREE:
2148 case OBJ_BLOB:
2149 case OBJ_TAG:
2150 break;
2151 default:
2152 error("unknown object type %i at offset %"PRIuMAX" in %s",
2153 type, (uintmax_t)obj_offset, p->pack_name);
2154 type = OBJ_BAD;
2155 }
2156
2157 out:
2158 if (poi_stack != small_poi_stack)
2159 free(poi_stack);
2160 return type;
2161
2162 unwind:
2163 while (poi_stack_nr) {
2164 obj_offset = poi_stack[--poi_stack_nr];
2165 type = retry_bad_packed_offset(p, obj_offset);
2166 if (type > OBJ_NONE)
2167 goto out;
2168 }
2169 type = OBJ_BAD;
2170 goto out;
2171 }
2172
2173 int packed_object_info(struct packed_git *p, off_t obj_offset,
2174 struct object_info *oi)
2175 {
2176 struct pack_window *w_curs = NULL;
2177 unsigned long size;
2178 off_t curpos = obj_offset;
2179 enum object_type type;
2180
2181 /*
2182 * We always get the representation type, but only convert it to
2183 * a "real" type later if the caller is interested.
2184 */
2185 type = unpack_object_header(p, &w_curs, &curpos, &size);
2186
2187 if (oi->sizep) {
2188 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2189 off_t tmp_pos = curpos;
2190 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2191 type, obj_offset);
2192 if (!base_offset) {
2193 type = OBJ_BAD;
2194 goto out;
2195 }
2196 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2197 if (*oi->sizep == 0) {
2198 type = OBJ_BAD;
2199 goto out;
2200 }
2201 } else {
2202 *oi->sizep = size;
2203 }
2204 }
2205
2206 if (oi->disk_sizep) {
2207 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2208 *oi->disk_sizep = revidx[1].offset - obj_offset;
2209 }
2210
2211 if (oi->typep) {
2212 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
2213 if (*oi->typep < 0) {
2214 type = OBJ_BAD;
2215 goto out;
2216 }
2217 }
2218
2219 if (oi->delta_base_sha1) {
2220 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2221 const unsigned char *base;
2222
2223 base = get_delta_base_sha1(p, &w_curs, curpos,
2224 type, obj_offset);
2225 if (!base) {
2226 type = OBJ_BAD;
2227 goto out;
2228 }
2229
2230 hashcpy(oi->delta_base_sha1, base);
2231 } else
2232 hashclr(oi->delta_base_sha1);
2233 }
2234
2235 out:
2236 unuse_pack(&w_curs);
2237 return type;
2238 }
2239
2240 static void *unpack_compressed_entry(struct packed_git *p,
2241 struct pack_window **w_curs,
2242 off_t curpos,
2243 unsigned long size)
2244 {
2245 int st;
2246 git_zstream stream;
2247 unsigned char *buffer, *in;
2248
2249 buffer = xmallocz_gently(size);
2250 if (!buffer)
2251 return NULL;
2252 memset(&stream, 0, sizeof(stream));
2253 stream.next_out = buffer;
2254 stream.avail_out = size + 1;
2255
2256 git_inflate_init(&stream);
2257 do {
2258 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2259 stream.next_in = in;
2260 st = git_inflate(&stream, Z_FINISH);
2261 if (!stream.avail_out)
2262 break; /* the payload is larger than it should be */
2263 curpos += stream.next_in - in;
2264 } while (st == Z_OK || st == Z_BUF_ERROR);
2265 git_inflate_end(&stream);
2266 if ((st != Z_STREAM_END) || stream.total_out != size) {
2267 free(buffer);
2268 return NULL;
2269 }
2270
2271 return buffer;
2272 }
2273
2274 static struct hashmap delta_base_cache;
2275 static size_t delta_base_cached;
2276
2277 static LIST_HEAD(delta_base_cache_lru);
2278
2279 struct delta_base_cache_key {
2280 struct packed_git *p;
2281 off_t base_offset;
2282 };
2283
2284 struct delta_base_cache_entry {
2285 struct hashmap hash;
2286 struct delta_base_cache_key key;
2287 struct list_head lru;
2288 void *data;
2289 unsigned long size;
2290 enum object_type type;
2291 };
2292
2293 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
2294 {
2295 unsigned int hash;
2296
2297 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
2298 hash += (hash >> 8) + (hash >> 16);
2299 return hash;
2300 }
2301
2302 static struct delta_base_cache_entry *
2303 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
2304 {
2305 struct hashmap_entry entry;
2306 struct delta_base_cache_key key;
2307
2308 if (!delta_base_cache.cmpfn)
2309 return NULL;
2310
2311 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
2312 key.p = p;
2313 key.base_offset = base_offset;
2314 return hashmap_get(&delta_base_cache, &entry, &key);
2315 }
2316
2317 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
2318 const struct delta_base_cache_key *b)
2319 {
2320 return a->p == b->p && a->base_offset == b->base_offset;
2321 }
2322
2323 static int delta_base_cache_hash_cmp(const void *va, const void *vb,
2324 const void *vkey)
2325 {
2326 const struct delta_base_cache_entry *a = va, *b = vb;
2327 const struct delta_base_cache_key *key = vkey;
2328 if (key)
2329 return !delta_base_cache_key_eq(&a->key, key);
2330 else
2331 return !delta_base_cache_key_eq(&a->key, &b->key);
2332 }
2333
2334 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2335 {
2336 return !!get_delta_base_cache_entry(p, base_offset);
2337 }
2338
2339 /*
2340 * Remove the entry from the cache, but do _not_ free the associated
2341 * entry data. The caller takes ownership of the "data" buffer, and
2342 * should copy out any fields it wants before detaching.
2343 */
2344 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2345 {
2346 hashmap_remove(&delta_base_cache, ent, &ent->key);
2347 list_del(&ent->lru);
2348 delta_base_cached -= ent->size;
2349 free(ent);
2350 }
2351
2352 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
2353 unsigned long *base_size, enum object_type *type)
2354 {
2355 struct delta_base_cache_entry *ent;
2356
2357 ent = get_delta_base_cache_entry(p, base_offset);
2358 if (!ent)
2359 return unpack_entry(p, base_offset, type, base_size);
2360
2361 *type = ent->type;
2362 *base_size = ent->size;
2363 return xmemdupz(ent->data, ent->size);
2364 }
2365
2366 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2367 {
2368 free(ent->data);
2369 detach_delta_base_cache_entry(ent);
2370 }
2371
2372 void clear_delta_base_cache(void)
2373 {
2374 struct list_head *lru, *tmp;
2375 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2376 struct delta_base_cache_entry *entry =
2377 list_entry(lru, struct delta_base_cache_entry, lru);
2378 release_delta_base_cache(entry);
2379 }
2380 }
2381
2382 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2383 void *base, unsigned long base_size, enum object_type type)
2384 {
2385 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
2386 struct list_head *lru, *tmp;
2387
2388 delta_base_cached += base_size;
2389
2390 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2391 struct delta_base_cache_entry *f =
2392 list_entry(lru, struct delta_base_cache_entry, lru);
2393 if (delta_base_cached <= delta_base_cache_limit)
2394 break;
2395 release_delta_base_cache(f);
2396 }
2397
2398 ent->key.p = p;
2399 ent->key.base_offset = base_offset;
2400 ent->type = type;
2401 ent->data = base;
2402 ent->size = base_size;
2403 list_add_tail(&ent->lru, &delta_base_cache_lru);
2404
2405 if (!delta_base_cache.cmpfn)
2406 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, 0);
2407 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
2408 hashmap_add(&delta_base_cache, ent);
2409 }
2410
2411 static void *read_object(const unsigned char *sha1, enum object_type *type,
2412 unsigned long *size);
2413
2414 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2415 {
2416 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2417 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2418 p->pack_name, (uintmax_t)obj_offset);
2419 }
2420
2421 int do_check_packed_object_crc;
2422
2423 #define UNPACK_ENTRY_STACK_PREALLOC 64
2424 struct unpack_entry_stack_ent {
2425 off_t obj_offset;
2426 off_t curpos;
2427 unsigned long size;
2428 };
2429
2430 void *unpack_entry(struct packed_git *p, off_t obj_offset,
2431 enum object_type *final_type, unsigned long *final_size)
2432 {
2433 struct pack_window *w_curs = NULL;
2434 off_t curpos = obj_offset;
2435 void *data = NULL;
2436 unsigned long size;
2437 enum object_type type;
2438 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2439 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2440 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2441 int base_from_cache = 0;
2442
2443 write_pack_access_log(p, obj_offset);
2444
2445 /* PHASE 1: drill down to the innermost base object */
2446 for (;;) {
2447 off_t base_offset;
2448 int i;
2449 struct delta_base_cache_entry *ent;
2450
2451 ent = get_delta_base_cache_entry(p, curpos);
2452 if (ent) {
2453 type = ent->type;
2454 data = ent->data;
2455 size = ent->size;
2456 detach_delta_base_cache_entry(ent);
2457 base_from_cache = 1;
2458 break;
2459 }
2460
2461 if (do_check_packed_object_crc && p->index_version > 1) {
2462 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2463 off_t len = revidx[1].offset - obj_offset;
2464 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2465 const unsigned char *sha1 =
2466 nth_packed_object_sha1(p, revidx->nr);
2467 error("bad packed object CRC for %s",
2468 sha1_to_hex(sha1));
2469 mark_bad_packed_object(p, sha1);
2470 unuse_pack(&w_curs);
2471 return NULL;
2472 }
2473 }
2474
2475 type = unpack_object_header(p, &w_curs, &curpos, &size);
2476 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2477 break;
2478
2479 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2480 if (!base_offset) {
2481 error("failed to validate delta base reference "
2482 "at offset %"PRIuMAX" from %s",
2483 (uintmax_t)curpos, p->pack_name);
2484 /* bail to phase 2, in hopes of recovery */
2485 data = NULL;
2486 break;
2487 }
2488
2489 /* push object, proceed to base */
2490 if (delta_stack_nr >= delta_stack_alloc
2491 && delta_stack == small_delta_stack) {
2492 delta_stack_alloc = alloc_nr(delta_stack_nr);
2493 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
2494 memcpy(delta_stack, small_delta_stack,
2495 sizeof(*delta_stack)*delta_stack_nr);
2496 } else {
2497 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2498 }
2499 i = delta_stack_nr++;
2500 delta_stack[i].obj_offset = obj_offset;
2501 delta_stack[i].curpos = curpos;
2502 delta_stack[i].size = size;
2503
2504 curpos = obj_offset = base_offset;
2505 }
2506
2507 /* PHASE 2: handle the base */
2508 switch (type) {
2509 case OBJ_OFS_DELTA:
2510 case OBJ_REF_DELTA:
2511 if (data)
2512 die("BUG: unpack_entry: left loop at a valid delta");
2513 break;
2514 case OBJ_COMMIT:
2515 case OBJ_TREE:
2516 case OBJ_BLOB:
2517 case OBJ_TAG:
2518 if (!base_from_cache)
2519 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2520 break;
2521 default:
2522 data = NULL;
2523 error("unknown object type %i at offset %"PRIuMAX" in %s",
2524 type, (uintmax_t)obj_offset, p->pack_name);
2525 }
2526
2527 /* PHASE 3: apply deltas in order */
2528
2529 /* invariants:
2530 * 'data' holds the base data, or NULL if there was corruption
2531 */
2532 while (delta_stack_nr) {
2533 void *delta_data;
2534 void *base = data;
2535 void *external_base = NULL;
2536 unsigned long delta_size, base_size = size;
2537 int i;
2538
2539 data = NULL;
2540
2541 if (base)
2542 add_delta_base_cache(p, obj_offset, base, base_size, type);
2543
2544 if (!base) {
2545 /*
2546 * We're probably in deep shit, but let's try to fetch
2547 * the required base anyway from another pack or loose.
2548 * This is costly but should happen only in the presence
2549 * of a corrupted pack, and is better than failing outright.
2550 */
2551 struct revindex_entry *revidx;
2552 const unsigned char *base_sha1;
2553 revidx = find_pack_revindex(p, obj_offset);
2554 if (revidx) {
2555 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2556 error("failed to read delta base object %s"
2557 " at offset %"PRIuMAX" from %s",
2558 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2559 p->pack_name);
2560 mark_bad_packed_object(p, base_sha1);
2561 base = read_object(base_sha1, &type, &base_size);
2562 external_base = base;
2563 }
2564 }
2565
2566 i = --delta_stack_nr;
2567 obj_offset = delta_stack[i].obj_offset;
2568 curpos = delta_stack[i].curpos;
2569 delta_size = delta_stack[i].size;
2570
2571 if (!base)
2572 continue;
2573
2574 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2575
2576 if (!delta_data) {
2577 error("failed to unpack compressed delta "
2578 "at offset %"PRIuMAX" from %s",
2579 (uintmax_t)curpos, p->pack_name);
2580 data = NULL;
2581 free(external_base);
2582 continue;
2583 }
2584
2585 data = patch_delta(base, base_size,
2586 delta_data, delta_size,
2587 &size);
2588
2589 /*
2590 * We could not apply the delta; warn the user, but keep going.
2591 * Our failure will be noticed either in the next iteration of
2592 * the loop, or if this is the final delta, in the caller when
2593 * we return NULL. Those code paths will take care of making
2594 * a more explicit warning and retrying with another copy of
2595 * the object.
2596 */
2597 if (!data)
2598 error("failed to apply delta");
2599
2600 free(delta_data);
2601 free(external_base);
2602 }
2603
2604 *final_type = type;
2605 *final_size = size;
2606
2607 unuse_pack(&w_curs);
2608
2609 if (delta_stack != small_delta_stack)
2610 free(delta_stack);
2611
2612 return data;
2613 }
2614
2615 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2616 uint32_t n)
2617 {
2618 const unsigned char *index = p->index_data;
2619 if (!index) {
2620 if (open_pack_index(p))
2621 return NULL;
2622 index = p->index_data;
2623 }
2624 if (n >= p->num_objects)
2625 return NULL;
2626 index += 4 * 256;
2627 if (p->index_version == 1) {
2628 return index + 24 * n + 4;
2629 } else {
2630 index += 8;
2631 return index + 20 * n;
2632 }
2633 }
2634
2635 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2636 {
2637 const unsigned char *ptr = vptr;
2638 const unsigned char *start = p->index_data;
2639 const unsigned char *end = start + p->index_size;
2640 if (ptr < start)
2641 die(_("offset before start of pack index for %s (corrupt index?)"),
2642 p->pack_name);
2643 /* No need to check for underflow; .idx files must be at least 8 bytes */
2644 if (ptr >= end - 8)
2645 die(_("offset beyond end of pack index for %s (truncated index?)"),
2646 p->pack_name);
2647 }
2648
2649 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2650 {
2651 const unsigned char *index = p->index_data;
2652 index += 4 * 256;
2653 if (p->index_version == 1) {
2654 return ntohl(*((uint32_t *)(index + 24 * n)));
2655 } else {
2656 uint32_t off;
2657 index += 8 + p->num_objects * (20 + 4);
2658 off = ntohl(*((uint32_t *)(index + 4 * n)));
2659 if (!(off & 0x80000000))
2660 return off;
2661 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2662 check_pack_index_ptr(p, index);
2663 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2664 ntohl(*((uint32_t *)(index + 4)));
2665 }
2666 }
2667
2668 off_t find_pack_entry_one(const unsigned char *sha1,
2669 struct packed_git *p)
2670 {
2671 const uint32_t *level1_ofs = p->index_data;
2672 const unsigned char *index = p->index_data;
2673 unsigned hi, lo, stride;
2674 static int use_lookup = -1;
2675 static int debug_lookup = -1;
2676
2677 if (debug_lookup < 0)
2678 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2679
2680 if (!index) {
2681 if (open_pack_index(p))
2682 return 0;
2683 level1_ofs = p->index_data;
2684 index = p->index_data;
2685 }
2686 if (p->index_version > 1) {
2687 level1_ofs += 2;
2688 index += 8;
2689 }
2690 index += 4 * 256;
2691 hi = ntohl(level1_ofs[*sha1]);
2692 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2693 if (p->index_version > 1) {
2694 stride = 20;
2695 } else {
2696 stride = 24;
2697 index += 4;
2698 }
2699
2700 if (debug_lookup)
2701 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2702 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2703
2704 if (use_lookup < 0)
2705 use_lookup = !!getenv("GIT_USE_LOOKUP");
2706 if (use_lookup) {
2707 int pos = sha1_entry_pos(index, stride, 0,
2708 lo, hi, p->num_objects, sha1);
2709 if (pos < 0)
2710 return 0;
2711 return nth_packed_object_offset(p, pos);
2712 }
2713
2714 do {
2715 unsigned mi = (lo + hi) / 2;
2716 int cmp = hashcmp(index + mi * stride, sha1);
2717
2718 if (debug_lookup)
2719 printf("lo %u hi %u rg %u mi %u\n",
2720 lo, hi, hi - lo, mi);
2721 if (!cmp)
2722 return nth_packed_object_offset(p, mi);
2723 if (cmp > 0)
2724 hi = mi;
2725 else
2726 lo = mi+1;
2727 } while (lo < hi);
2728 return 0;
2729 }
2730
2731 int is_pack_valid(struct packed_git *p)
2732 {
2733 /* An already open pack is known to be valid. */
2734 if (p->pack_fd != -1)
2735 return 1;
2736
2737 /* If the pack has one window completely covering the
2738 * file size, the pack is known to be valid even if
2739 * the descriptor is not currently open.
2740 */
2741 if (p->windows) {
2742 struct pack_window *w = p->windows;
2743
2744 if (!w->offset && w->len == p->pack_size)
2745 return 1;
2746 }
2747
2748 /* Force the pack to open to prove its valid. */
2749 return !open_packed_git(p);
2750 }
2751
2752 static int fill_pack_entry(const unsigned char *sha1,
2753 struct pack_entry *e,
2754 struct packed_git *p)
2755 {
2756 off_t offset;
2757
2758 if (p->num_bad_objects) {
2759 unsigned i;
2760 for (i = 0; i < p->num_bad_objects; i++)
2761 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2762 return 0;
2763 }
2764
2765 offset = find_pack_entry_one(sha1, p);
2766 if (!offset)
2767 return 0;
2768
2769 /*
2770 * We are about to tell the caller where they can locate the
2771 * requested object. We better make sure the packfile is
2772 * still here and can be accessed before supplying that
2773 * answer, as it may have been deleted since the index was
2774 * loaded!
2775 */
2776 if (!is_pack_valid(p))
2777 return 0;
2778 e->offset = offset;
2779 e->p = p;
2780 hashcpy(e->sha1, sha1);
2781 return 1;
2782 }
2783
2784 /*
2785 * Iff a pack file contains the object named by sha1, return true and
2786 * store its location to e.
2787 */
2788 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2789 {
2790 struct mru_entry *p;
2791
2792 prepare_packed_git();
2793 if (!packed_git)
2794 return 0;
2795
2796 for (p = packed_git_mru->head; p; p = p->next) {
2797 if (fill_pack_entry(sha1, e, p->item)) {
2798 mru_mark(packed_git_mru, p);
2799 return 1;
2800 }
2801 }
2802 return 0;
2803 }
2804
2805 struct packed_git *find_sha1_pack(const unsigned char *sha1,
2806 struct packed_git *packs)
2807 {
2808 struct packed_git *p;
2809
2810 for (p = packs; p; p = p->next) {
2811 if (find_pack_entry_one(sha1, p))
2812 return p;
2813 }
2814 return NULL;
2815
2816 }
2817
2818 static int sha1_loose_object_info(const unsigned char *sha1,
2819 struct object_info *oi,
2820 int flags)
2821 {
2822 int status = 0;
2823 unsigned long mapsize;
2824 void *map;
2825 git_zstream stream;
2826 char hdr[32];
2827 struct strbuf hdrbuf = STRBUF_INIT;
2828
2829 if (oi->delta_base_sha1)
2830 hashclr(oi->delta_base_sha1);
2831
2832 /*
2833 * If we don't care about type or size, then we don't
2834 * need to look inside the object at all. Note that we
2835 * do not optimize out the stat call, even if the
2836 * caller doesn't care about the disk-size, since our
2837 * return value implicitly indicates whether the
2838 * object even exists.
2839 */
2840 if (!oi->typep && !oi->typename && !oi->sizep) {
2841 const char *path;
2842 struct stat st;
2843 if (stat_sha1_file(sha1, &st, &path) < 0)
2844 return -1;
2845 if (oi->disk_sizep)
2846 *oi->disk_sizep = st.st_size;
2847 return 0;
2848 }
2849
2850 map = map_sha1_file(sha1, &mapsize);
2851 if (!map)
2852 return -1;
2853 if (oi->disk_sizep)
2854 *oi->disk_sizep = mapsize;
2855 if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
2856 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2857 status = error("unable to unpack %s header with --allow-unknown-type",
2858 sha1_to_hex(sha1));
2859 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2860 status = error("unable to unpack %s header",
2861 sha1_to_hex(sha1));
2862 if (status < 0)
2863 ; /* Do nothing */
2864 else if (hdrbuf.len) {
2865 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2866 status = error("unable to parse %s header with --allow-unknown-type",
2867 sha1_to_hex(sha1));
2868 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
2869 status = error("unable to parse %s header", sha1_to_hex(sha1));
2870 git_inflate_end(&stream);
2871 munmap(map, mapsize);
2872 if (status && oi->typep)
2873 *oi->typep = status;
2874 strbuf_release(&hdrbuf);
2875 return 0;
2876 }
2877
2878 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
2879 {
2880 struct cached_object *co;
2881 struct pack_entry e;
2882 int rtype;
2883 enum object_type real_type;
2884 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
2885
2886 co = find_cached_object(real);
2887 if (co) {
2888 if (oi->typep)
2889 *(oi->typep) = co->type;
2890 if (oi->sizep)
2891 *(oi->sizep) = co->size;
2892 if (oi->disk_sizep)
2893 *(oi->disk_sizep) = 0;
2894 if (oi->delta_base_sha1)
2895 hashclr(oi->delta_base_sha1);
2896 if (oi->typename)
2897 strbuf_addstr(oi->typename, typename(co->type));
2898 oi->whence = OI_CACHED;
2899 return 0;
2900 }
2901
2902 if (!find_pack_entry(real, &e)) {
2903 /* Most likely it's a loose object. */
2904 if (!sha1_loose_object_info(real, oi, flags)) {
2905 oi->whence = OI_LOOSE;
2906 return 0;
2907 }
2908
2909 /* Not a loose object; someone else may have just packed it. */
2910 reprepare_packed_git();
2911 if (!find_pack_entry(real, &e))
2912 return -1;
2913 }
2914
2915 /*
2916 * packed_object_info() does not follow the delta chain to
2917 * find out the real type, unless it is given oi->typep.
2918 */
2919 if (oi->typename && !oi->typep)
2920 oi->typep = &real_type;
2921
2922 rtype = packed_object_info(e.p, e.offset, oi);
2923 if (rtype < 0) {
2924 mark_bad_packed_object(e.p, real);
2925 if (oi->typep == &real_type)
2926 oi->typep = NULL;
2927 return sha1_object_info_extended(real, oi, 0);
2928 } else if (in_delta_base_cache(e.p, e.offset)) {
2929 oi->whence = OI_DBCACHED;
2930 } else {
2931 oi->whence = OI_PACKED;
2932 oi->u.packed.offset = e.offset;
2933 oi->u.packed.pack = e.p;
2934 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2935 rtype == OBJ_OFS_DELTA);
2936 }
2937 if (oi->typename)
2938 strbuf_addstr(oi->typename, typename(*oi->typep));
2939 if (oi->typep == &real_type)
2940 oi->typep = NULL;
2941
2942 return 0;
2943 }
2944
2945 /* returns enum object_type or negative */
2946 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2947 {
2948 enum object_type type;
2949 struct object_info oi = OBJECT_INFO_INIT;
2950
2951 oi.typep = &type;
2952 oi.sizep = sizep;
2953 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
2954 return -1;
2955 return type;
2956 }
2957
2958 static void *read_packed_sha1(const unsigned char *sha1,
2959 enum object_type *type, unsigned long *size)
2960 {
2961 struct pack_entry e;
2962 void *data;
2963
2964 if (!find_pack_entry(sha1, &e))
2965 return NULL;
2966 data = cache_or_unpack_entry(e.p, e.offset, size, type);
2967 if (!data) {
2968 /*
2969 * We're probably in deep shit, but let's try to fetch
2970 * the required object anyway from another pack or loose.
2971 * This should happen only in the presence of a corrupted
2972 * pack, and is better than failing outright.
2973 */
2974 error("failed to read object %s at offset %"PRIuMAX" from %s",
2975 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2976 mark_bad_packed_object(e.p, sha1);
2977 data = read_object(sha1, type, size);
2978 }
2979 return data;
2980 }
2981
2982 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2983 unsigned char *sha1)
2984 {
2985 struct cached_object *co;
2986
2987 hash_sha1_file(buf, len, typename(type), sha1);
2988 if (has_sha1_file(sha1) || find_cached_object(sha1))
2989 return 0;
2990 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
2991 co = &cached_objects[cached_object_nr++];
2992 co->size = len;
2993 co->type = type;
2994 co->buf = xmalloc(len);
2995 memcpy(co->buf, buf, len);
2996 hashcpy(co->sha1, sha1);
2997 return 0;
2998 }
2999
3000 static void *read_object(const unsigned char *sha1, enum object_type *type,
3001 unsigned long *size)
3002 {
3003 unsigned long mapsize;
3004 void *map, *buf;
3005 struct cached_object *co;
3006
3007 co = find_cached_object(sha1);
3008 if (co) {
3009 *type = co->type;
3010 *size = co->size;
3011 return xmemdupz(co->buf, co->size);
3012 }
3013
3014 buf = read_packed_sha1(sha1, type, size);
3015 if (buf)
3016 return buf;
3017 map = map_sha1_file(sha1, &mapsize);
3018 if (map) {
3019 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
3020 munmap(map, mapsize);
3021 return buf;
3022 }
3023 reprepare_packed_git();
3024 return read_packed_sha1(sha1, type, size);
3025 }
3026
3027 /*
3028 * This function dies on corrupt objects; the callers who want to
3029 * deal with them should arrange to call read_object() and give error
3030 * messages themselves.
3031 */
3032 void *read_sha1_file_extended(const unsigned char *sha1,
3033 enum object_type *type,
3034 unsigned long *size,
3035 unsigned flag)
3036 {
3037 void *data;
3038 const struct packed_git *p;
3039 const char *path;
3040 struct stat st;
3041 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
3042
3043 errno = 0;
3044 data = read_object(repl, type, size);
3045 if (data)
3046 return data;
3047
3048 if (errno && errno != ENOENT)
3049 die_errno("failed to read object %s", sha1_to_hex(sha1));
3050
3051 /* die if we replaced an object with one that does not exist */
3052 if (repl != sha1)
3053 die("replacement %s not found for %s",
3054 sha1_to_hex(repl), sha1_to_hex(sha1));
3055
3056 if (!stat_sha1_file(repl, &st, &path))
3057 die("loose object %s (stored in %s) is corrupt",
3058 sha1_to_hex(repl), path);
3059
3060 if ((p = has_packed_and_bad(repl)) != NULL)
3061 die("packed object %s (stored in %s) is corrupt",
3062 sha1_to_hex(repl), p->pack_name);
3063
3064 return NULL;
3065 }
3066
3067 void *read_object_with_reference(const unsigned char *sha1,
3068 const char *required_type_name,
3069 unsigned long *size,
3070 unsigned char *actual_sha1_return)
3071 {
3072 enum object_type type, required_type;
3073 void *buffer;
3074 unsigned long isize;
3075 unsigned char actual_sha1[20];
3076
3077 required_type = type_from_string(required_type_name);
3078 hashcpy(actual_sha1, sha1);
3079 while (1) {
3080 int ref_length = -1;
3081 const char *ref_type = NULL;
3082
3083 buffer = read_sha1_file(actual_sha1, &type, &isize);
3084 if (!buffer)
3085 return NULL;
3086 if (type == required_type) {
3087 *size = isize;
3088 if (actual_sha1_return)
3089 hashcpy(actual_sha1_return, actual_sha1);
3090 return buffer;
3091 }
3092 /* Handle references */
3093 else if (type == OBJ_COMMIT)
3094 ref_type = "tree ";
3095 else if (type == OBJ_TAG)
3096 ref_type = "object ";
3097 else {
3098 free(buffer);
3099 return NULL;
3100 }
3101 ref_length = strlen(ref_type);
3102
3103 if (ref_length + 40 > isize ||
3104 memcmp(buffer, ref_type, ref_length) ||
3105 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
3106 free(buffer);
3107 return NULL;
3108 }
3109 free(buffer);
3110 /* Now we have the ID of the referred-to object in
3111 * actual_sha1. Check again. */
3112 }
3113 }
3114
3115 static void write_sha1_file_prepare(const void *buf, unsigned long len,
3116 const char *type, unsigned char *sha1,
3117 char *hdr, int *hdrlen)
3118 {
3119 git_SHA_CTX c;
3120
3121 /* Generate the header */
3122 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
3123
3124 /* Sha1.. */
3125 git_SHA1_Init(&c);
3126 git_SHA1_Update(&c, hdr, *hdrlen);
3127 git_SHA1_Update(&c, buf, len);
3128 git_SHA1_Final(sha1, &c);
3129 }
3130
3131 /*
3132 * Move the just written object into its final resting place.
3133 */
3134 int finalize_object_file(const char *tmpfile, const char *filename)
3135 {
3136 int ret = 0;
3137
3138 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
3139 goto try_rename;
3140 else if (link(tmpfile, filename))
3141 ret = errno;
3142
3143 /*
3144 * Coda hack - coda doesn't like cross-directory links,
3145 * so we fall back to a rename, which will mean that it
3146 * won't be able to check collisions, but that's not a
3147 * big deal.
3148 *
3149 * The same holds for FAT formatted media.
3150 *
3151 * When this succeeds, we just return. We have nothing
3152 * left to unlink.
3153 */
3154 if (ret && ret != EEXIST) {
3155 try_rename:
3156 if (!rename(tmpfile, filename))
3157 goto out;
3158 ret = errno;
3159 }
3160 unlink_or_warn(tmpfile);
3161 if (ret) {
3162 if (ret != EEXIST) {
3163 return error_errno("unable to write sha1 filename %s", filename);
3164 }
3165 /* FIXME!!! Collision check here ? */
3166 }
3167
3168 out:
3169 if (adjust_shared_perm(filename))
3170 return error("unable to set permission to '%s'", filename);
3171 return 0;
3172 }
3173
3174 static int write_buffer(int fd, const void *buf, size_t len)
3175 {
3176 if (write_in_full(fd, buf, len) < 0)
3177 return error_errno("file write error");
3178 return 0;
3179 }
3180
3181 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
3182 unsigned char *sha1)
3183 {
3184 char hdr[32];
3185 int hdrlen = sizeof(hdr);
3186 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3187 return 0;
3188 }
3189
3190 /* Finalize a file on disk, and close it. */
3191 static void close_sha1_file(int fd)
3192 {
3193 if (fsync_object_files)
3194 fsync_or_die(fd, "sha1 file");
3195 if (close(fd) != 0)
3196 die_errno("error when closing sha1 file");
3197 }
3198
3199 /* Size of directory component, including the ending '/' */
3200 static inline int directory_size(const char *filename)
3201 {
3202 const char *s = strrchr(filename, '/');
3203 if (!s)
3204 return 0;
3205 return s - filename + 1;
3206 }
3207
3208 /*
3209 * This creates a temporary file in the same directory as the final
3210 * 'filename'
3211 *
3212 * We want to avoid cross-directory filename renames, because those
3213 * can have problems on various filesystems (FAT, NFS, Coda).
3214 */
3215 static int create_tmpfile(struct strbuf *tmp, const char *filename)
3216 {
3217 int fd, dirlen = directory_size(filename);
3218
3219 strbuf_reset(tmp);
3220 strbuf_add(tmp, filename, dirlen);
3221 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3222 fd = git_mkstemp_mode(tmp->buf, 0444);
3223 if (fd < 0 && dirlen && errno == ENOENT) {
3224 /*
3225 * Make sure the directory exists; note that the contents
3226 * of the buffer are undefined after mkstemp returns an
3227 * error, so we have to rewrite the whole buffer from
3228 * scratch.
3229 */
3230 strbuf_reset(tmp);
3231 strbuf_add(tmp, filename, dirlen - 1);
3232 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
3233 return -1;
3234 if (adjust_shared_perm(tmp->buf))
3235 return -1;
3236
3237 /* Try again */
3238 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3239 fd = git_mkstemp_mode(tmp->buf, 0444);
3240 }
3241 return fd;
3242 }
3243
3244 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
3245 const void *buf, unsigned long len, time_t mtime)
3246 {
3247 int fd, ret;
3248 unsigned char compressed[4096];
3249 git_zstream stream;
3250 git_SHA_CTX c;
3251 unsigned char parano_sha1[20];
3252 static struct strbuf tmp_file = STRBUF_INIT;
3253 const char *filename = sha1_file_name(sha1);
3254
3255 fd = create_tmpfile(&tmp_file, filename);
3256 if (fd < 0) {
3257 if (errno == EACCES)
3258 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
3259 else
3260 return error_errno("unable to create temporary file");
3261 }
3262
3263 /* Set it up */
3264 git_deflate_init(&stream, zlib_compression_level);
3265 stream.next_out = compressed;
3266 stream.avail_out = sizeof(compressed);
3267 git_SHA1_Init(&c);
3268
3269 /* First header.. */
3270 stream.next_in = (unsigned char *)hdr;
3271 stream.avail_in = hdrlen;
3272 while (git_deflate(&stream, 0) == Z_OK)
3273 ; /* nothing */
3274 git_SHA1_Update(&c, hdr, hdrlen);
3275
3276 /* Then the data itself.. */
3277 stream.next_in = (void *)buf;
3278 stream.avail_in = len;
3279 do {
3280 unsigned char *in0 = stream.next_in;
3281 ret = git_deflate(&stream, Z_FINISH);
3282 git_SHA1_Update(&c, in0, stream.next_in - in0);
3283 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3284 die("unable to write sha1 file");
3285 stream.next_out = compressed;
3286 stream.avail_out = sizeof(compressed);
3287 } while (ret == Z_OK);
3288
3289 if (ret != Z_STREAM_END)
3290 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
3291 ret = git_deflate_end_gently(&stream);
3292 if (ret != Z_OK)
3293 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
3294 git_SHA1_Final(parano_sha1, &c);
3295 if (hashcmp(sha1, parano_sha1) != 0)
3296 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
3297
3298 close_sha1_file(fd);
3299
3300 if (mtime) {
3301 struct utimbuf utb;
3302 utb.actime = mtime;
3303 utb.modtime = mtime;
3304 if (utime(tmp_file.buf, &utb) < 0)
3305 warning_errno("failed utime() on %s", tmp_file.buf);
3306 }
3307
3308 return finalize_object_file(tmp_file.buf, filename);
3309 }
3310
3311 static int freshen_loose_object(const unsigned char *sha1)
3312 {
3313 return check_and_freshen(sha1, 1);
3314 }
3315
3316 static int freshen_packed_object(const unsigned char *sha1)
3317 {
3318 struct pack_entry e;
3319 if (!find_pack_entry(sha1, &e))
3320 return 0;
3321 if (e.p->freshened)
3322 return 1;
3323 if (!freshen_file(e.p->pack_name))
3324 return 0;
3325 e.p->freshened = 1;
3326 return 1;
3327 }
3328
3329 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
3330 {
3331 char hdr[32];
3332 int hdrlen = sizeof(hdr);
3333
3334 /* Normally if we have it in the pack then we do not bother writing
3335 * it out into .git/objects/??/?{38} file.
3336 */
3337 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3338 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3339 return 0;
3340 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3341 }
3342
3343 int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3344 unsigned char *sha1, unsigned flags)
3345 {
3346 char *header;
3347 int hdrlen, status = 0;
3348
3349 /* type string, SP, %lu of the length plus NUL must fit this */
3350 hdrlen = strlen(type) + 32;
3351 header = xmalloc(hdrlen);
3352 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3353
3354 if (!(flags & HASH_WRITE_OBJECT))
3355 goto cleanup;
3356 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3357 goto cleanup;
3358 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3359
3360 cleanup:
3361 free(header);
3362 return status;
3363 }
3364
3365 int force_object_loose(const unsigned char *sha1, time_t mtime)
3366 {
3367 void *buf;
3368 unsigned long len;
3369 enum object_type type;
3370 char hdr[32];
3371 int hdrlen;
3372 int ret;
3373
3374 if (has_loose_object(sha1))
3375 return 0;
3376 buf = read_packed_sha1(sha1, &type, &len);
3377 if (!buf)
3378 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
3379 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
3380 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3381 free(buf);
3382
3383 return ret;
3384 }
3385
3386 int has_pack_index(const unsigned char *sha1)
3387 {
3388 struct stat st;
3389 if (stat(sha1_pack_index_name(sha1), &st))
3390 return 0;
3391 return 1;
3392 }
3393
3394 int has_sha1_pack(const unsigned char *sha1)
3395 {
3396 struct pack_entry e;
3397 return find_pack_entry(sha1, &e);
3398 }
3399
3400 int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
3401 {
3402 struct pack_entry e;
3403
3404 if (find_pack_entry(sha1, &e))
3405 return 1;
3406 if (has_loose_object(sha1))
3407 return 1;
3408 if (flags & HAS_SHA1_QUICK)
3409 return 0;
3410 reprepare_packed_git();
3411 return find_pack_entry(sha1, &e);
3412 }
3413
3414 int has_object_file(const struct object_id *oid)
3415 {
3416 return has_sha1_file(oid->hash);
3417 }
3418
3419 int has_object_file_with_flags(const struct object_id *oid, int flags)
3420 {
3421 return has_sha1_file_with_flags(oid->hash, flags);
3422 }
3423
3424 static void check_tree(const void *buf, size_t size)
3425 {
3426 struct tree_desc desc;
3427 struct name_entry entry;
3428
3429 init_tree_desc(&desc, buf, size);
3430 while (tree_entry(&desc, &entry))
3431 /* do nothing
3432 * tree_entry() will die() on malformed entries */
3433 ;
3434 }
3435
3436 static void check_commit(const void *buf, size_t size)
3437 {
3438 struct commit c;
3439 memset(&c, 0, sizeof(c));
3440 if (parse_commit_buffer(&c, buf, size))
3441 die("corrupt commit");
3442 }
3443
3444 static void check_tag(const void *buf, size_t size)
3445 {
3446 struct tag t;
3447 memset(&t, 0, sizeof(t));
3448 if (parse_tag_buffer(&t, buf, size))
3449 die("corrupt tag");
3450 }
3451
3452 static int index_mem(unsigned char *sha1, void *buf, size_t size,
3453 enum object_type type,
3454 const char *path, unsigned flags)
3455 {
3456 int ret, re_allocated = 0;
3457 int write_object = flags & HASH_WRITE_OBJECT;
3458
3459 if (!type)
3460 type = OBJ_BLOB;
3461
3462 /*
3463 * Convert blobs to git internal format
3464 */
3465 if ((type == OBJ_BLOB) && path) {
3466 struct strbuf nbuf = STRBUF_INIT;
3467 if (convert_to_git(path, buf, size, &nbuf,
3468 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
3469 buf = strbuf_detach(&nbuf, &size);
3470 re_allocated = 1;
3471 }
3472 }
3473 if (flags & HASH_FORMAT_CHECK) {
3474 if (type == OBJ_TREE)
3475 check_tree(buf, size);
3476 if (type == OBJ_COMMIT)
3477 check_commit(buf, size);
3478 if (type == OBJ_TAG)
3479 check_tag(buf, size);
3480 }
3481
3482 if (write_object)
3483 ret = write_sha1_file(buf, size, typename(type), sha1);
3484 else
3485 ret = hash_sha1_file(buf, size, typename(type), sha1);
3486 if (re_allocated)
3487 free(buf);
3488 return ret;
3489 }
3490
3491 static int index_stream_convert_blob(unsigned char *sha1, int fd,
3492 const char *path, unsigned flags)
3493 {
3494 int ret;
3495 const int write_object = flags & HASH_WRITE_OBJECT;
3496 struct strbuf sbuf = STRBUF_INIT;
3497
3498 assert(path);
3499 assert(would_convert_to_git_filter_fd(path));
3500
3501 convert_to_git_filter_fd(path, fd, &sbuf,
3502 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3503
3504 if (write_object)
3505 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3506 sha1);
3507 else
3508 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3509 sha1);
3510 strbuf_release(&sbuf);
3511 return ret;
3512 }
3513
3514 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3515 const char *path, unsigned flags)
3516 {
3517 struct strbuf sbuf = STRBUF_INIT;
3518 int ret;
3519
3520 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3521 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3522 else
3523 ret = -1;
3524 strbuf_release(&sbuf);
3525 return ret;
3526 }
3527
3528 #define SMALL_FILE_SIZE (32*1024)
3529
3530 static int index_core(unsigned char *sha1, int fd, size_t size,
3531 enum object_type type, const char *path,
3532 unsigned flags)
3533 {
3534 int ret;
3535
3536 if (!size) {
3537 ret = index_mem(sha1, "", size, type, path, flags);
3538 } else if (size <= SMALL_FILE_SIZE) {
3539 char *buf = xmalloc(size);
3540 if (size == read_in_full(fd, buf, size))
3541 ret = index_mem(sha1, buf, size, type, path, flags);
3542 else
3543 ret = error_errno("short read");
3544 free(buf);
3545 } else {
3546 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3547 ret = index_mem(sha1, buf, size, type, path, flags);
3548 munmap(buf, size);
3549 }
3550 return ret;
3551 }
3552
3553 /*
3554 * This creates one packfile per large blob unless bulk-checkin
3555 * machinery is "plugged".
3556 *
3557 * This also bypasses the usual "convert-to-git" dance, and that is on
3558 * purpose. We could write a streaming version of the converting
3559 * functions and insert that before feeding the data to fast-import
3560 * (or equivalent in-core API described above). However, that is
3561 * somewhat complicated, as we do not know the size of the filter
3562 * result, which we need to know beforehand when writing a git object.
3563 * Since the primary motivation for trying to stream from the working
3564 * tree file and to avoid mmaping it in core is to deal with large
3565 * binary blobs, they generally do not want to get any conversion, and
3566 * callers should avoid this code path when filters are requested.
3567 */
3568 static int index_stream(unsigned char *sha1, int fd, size_t size,
3569 enum object_type type, const char *path,
3570 unsigned flags)
3571 {
3572 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3573 }
3574
3575 int index_fd(unsigned char *sha1, int fd, struct stat *st,
3576 enum object_type type, const char *path, unsigned flags)
3577 {
3578 int ret;
3579
3580 /*
3581 * Call xsize_t() only when needed to avoid potentially unnecessary
3582 * die() for large files.
3583 */
3584 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3585 ret = index_stream_convert_blob(sha1, fd, path, flags);
3586 else if (!S_ISREG(st->st_mode))
3587 ret = index_pipe(sha1, fd, type, path, flags);
3588 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
3589 (path && would_convert_to_git(path)))
3590 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3591 flags);
3592 else
3593 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3594 flags);
3595 close(fd);
3596 return ret;
3597 }
3598
3599 int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3600 {
3601 int fd;
3602 struct strbuf sb = STRBUF_INIT;
3603
3604 switch (st->st_mode & S_IFMT) {
3605 case S_IFREG:
3606 fd = open(path, O_RDONLY);
3607 if (fd < 0)
3608 return error_errno("open(\"%s\")", path);
3609 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3610 return error("%s: failed to insert into database",
3611 path);
3612 break;
3613 case S_IFLNK:
3614 if (strbuf_readlink(&sb, path, st->st_size))
3615 return error_errno("readlink(\"%s\")", path);
3616 if (!(flags & HASH_WRITE_OBJECT))
3617 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3618 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3619 return error("%s: failed to insert into database",
3620 path);
3621 strbuf_release(&sb);
3622 break;
3623 case S_IFDIR:
3624 return resolve_gitlink_ref(path, "HEAD", sha1);
3625 default:
3626 return error("%s: unsupported file type", path);
3627 }
3628 return 0;
3629 }
3630
3631 int read_pack_header(int fd, struct pack_header *header)
3632 {
3633 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3634 /* "eof before pack header was fully read" */
3635 return PH_ERROR_EOF;
3636
3637 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3638 /* "protocol error (pack signature mismatch detected)" */
3639 return PH_ERROR_PACK_SIGNATURE;
3640 if (!pack_version_ok(header->hdr_version))
3641 /* "protocol error (pack version unsupported)" */
3642 return PH_ERROR_PROTOCOL;
3643 return 0;
3644 }
3645
3646 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3647 {
3648 enum object_type type = sha1_object_info(sha1, NULL);
3649 if (type < 0)
3650 die("%s is not a valid object", sha1_to_hex(sha1));
3651 if (type != expect)
3652 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3653 typename(expect));
3654 }
3655
3656 static int for_each_file_in_obj_subdir(int subdir_nr,
3657 struct strbuf *path,
3658 each_loose_object_fn obj_cb,
3659 each_loose_cruft_fn cruft_cb,
3660 each_loose_subdir_fn subdir_cb,
3661 void *data)
3662 {
3663 size_t baselen = path->len;
3664 DIR *dir = opendir(path->buf);
3665 struct dirent *de;
3666 int r = 0;
3667
3668 if (!dir) {
3669 if (errno == ENOENT)
3670 return 0;
3671 return error_errno("unable to open %s", path->buf);
3672 }
3673
3674 while ((de = readdir(dir))) {
3675 if (is_dot_or_dotdot(de->d_name))
3676 continue;
3677
3678 strbuf_setlen(path, baselen);
3679 strbuf_addf(path, "/%s", de->d_name);
3680
3681 if (strlen(de->d_name) == 38) {
3682 char hex[41];
3683 unsigned char sha1[20];
3684
3685 snprintf(hex, sizeof(hex), "%02x%s",
3686 subdir_nr, de->d_name);
3687 if (!get_sha1_hex(hex, sha1)) {
3688 if (obj_cb) {
3689 r = obj_cb(sha1, path->buf, data);
3690 if (r)
3691 break;
3692 }
3693 continue;
3694 }
3695 }
3696
3697 if (cruft_cb) {
3698 r = cruft_cb(de->d_name, path->buf, data);
3699 if (r)
3700 break;
3701 }
3702 }
3703 closedir(dir);
3704
3705 strbuf_setlen(path, baselen);
3706 if (!r && subdir_cb)
3707 r = subdir_cb(subdir_nr, path->buf, data);
3708
3709 return r;
3710 }
3711
3712 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
3713 each_loose_object_fn obj_cb,
3714 each_loose_cruft_fn cruft_cb,
3715 each_loose_subdir_fn subdir_cb,
3716 void *data)
3717 {
3718 size_t baselen = path->len;
3719 int r = 0;
3720 int i;
3721
3722 for (i = 0; i < 256; i++) {
3723 strbuf_addf(path, "/%02x", i);
3724 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
3725 subdir_cb, data);
3726 strbuf_setlen(path, baselen);
3727 if (r)
3728 break;
3729 }
3730
3731 return r;
3732 }
3733
3734 int for_each_loose_file_in_objdir(const char *path,
3735 each_loose_object_fn obj_cb,
3736 each_loose_cruft_fn cruft_cb,
3737 each_loose_subdir_fn subdir_cb,
3738 void *data)
3739 {
3740 struct strbuf buf = STRBUF_INIT;
3741 int r;
3742
3743 strbuf_addstr(&buf, path);
3744 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
3745 subdir_cb, data);
3746 strbuf_release(&buf);
3747
3748 return r;
3749 }
3750
3751 struct loose_alt_odb_data {
3752 each_loose_object_fn *cb;
3753 void *data;
3754 };
3755
3756 static int loose_from_alt_odb(struct alternate_object_database *alt,
3757 void *vdata)
3758 {
3759 struct loose_alt_odb_data *data = vdata;
3760 struct strbuf buf = STRBUF_INIT;
3761 int r;
3762
3763 strbuf_addstr(&buf, alt->path);
3764 r = for_each_loose_file_in_objdir_buf(&buf,
3765 data->cb, NULL, NULL,
3766 data->data);
3767 strbuf_release(&buf);
3768 return r;
3769 }
3770
3771 int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
3772 {
3773 struct loose_alt_odb_data alt;
3774 int r;
3775
3776 r = for_each_loose_file_in_objdir(get_object_directory(),
3777 cb, NULL, NULL, data);
3778 if (r)
3779 return r;
3780
3781 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
3782 return 0;
3783
3784 alt.cb = cb;
3785 alt.data = data;
3786 return foreach_alt_odb(loose_from_alt_odb, &alt);
3787 }
3788
3789 static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
3790 {
3791 uint32_t i;
3792 int r = 0;
3793
3794 for (i = 0; i < p->num_objects; i++) {
3795 const unsigned char *sha1 = nth_packed_object_sha1(p, i);
3796
3797 if (!sha1)
3798 return error("unable to get sha1 of object %u in %s",
3799 i, p->pack_name);
3800
3801 r = cb(sha1, p, i, data);
3802 if (r)
3803 break;
3804 }
3805 return r;
3806 }
3807
3808 int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
3809 {
3810 struct packed_git *p;
3811 int r = 0;
3812 int pack_errors = 0;
3813
3814 prepare_packed_git();
3815 for (p = packed_git; p; p = p->next) {
3816 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
3817 continue;
3818 if (open_pack_index(p)) {
3819 pack_errors = 1;
3820 continue;
3821 }
3822 r = for_each_object_in_pack(p, cb, data);
3823 if (r)
3824 break;
3825 }
3826 return r ? r : pack_errors;
3827 }
3828
3829 static int check_stream_sha1(git_zstream *stream,
3830 const char *hdr,
3831 unsigned long size,
3832 const char *path,
3833 const unsigned char *expected_sha1)
3834 {
3835 git_SHA_CTX c;
3836 unsigned char real_sha1[GIT_SHA1_RAWSZ];
3837 unsigned char buf[4096];
3838 unsigned long total_read;
3839 int status = Z_OK;
3840
3841 git_SHA1_Init(&c);
3842 git_SHA1_Update(&c, hdr, stream->total_out);
3843
3844 /*
3845 * We already read some bytes into hdr, but the ones up to the NUL
3846 * do not count against the object's content size.
3847 */
3848 total_read = stream->total_out - strlen(hdr) - 1;
3849
3850 /*
3851 * This size comparison must be "<=" to read the final zlib packets;
3852 * see the comment in unpack_sha1_rest for details.
3853 */
3854 while (total_read <= size &&
3855 (status == Z_OK || status == Z_BUF_ERROR)) {
3856 stream->next_out = buf;
3857 stream->avail_out = sizeof(buf