Merge branch 'nd/init-core-worktree-in-multi-worktree-world'
[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
30 #ifndef O_NOATIME
31 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
32 #define O_NOATIME 01000000
33 #else
34 #define O_NOATIME 0
35 #endif
36 #endif
37
38 #define SZ_FMT PRIuMAX
39 static inline uintmax_t sz_fmt(size_t s) { return s; }
40
41 const unsigned char null_sha1[20];
42 const struct object_id null_oid;
43 const struct object_id empty_tree_oid = {
44 EMPTY_TREE_SHA1_BIN_LITERAL
45 };
46 const struct object_id empty_blob_oid = {
47 EMPTY_BLOB_SHA1_BIN_LITERAL
48 };
49
50 /*
51 * This is meant to hold a *small* number of objects that you would
52 * want read_sha1_file() to be able to return, but yet you do not want
53 * to write them into the object store (e.g. a browse-only
54 * application).
55 */
56 static struct cached_object {
57 unsigned char sha1[20];
58 enum object_type type;
59 void *buf;
60 unsigned long size;
61 } *cached_objects;
62 static int cached_object_nr, cached_object_alloc;
63
64 static struct cached_object empty_tree = {
65 EMPTY_TREE_SHA1_BIN_LITERAL,
66 OBJ_TREE,
67 "",
68 0
69 };
70
71 static struct cached_object *find_cached_object(const unsigned char *sha1)
72 {
73 int i;
74 struct cached_object *co = cached_objects;
75
76 for (i = 0; i < cached_object_nr; i++, co++) {
77 if (!hashcmp(co->sha1, sha1))
78 return co;
79 }
80 if (!hashcmp(sha1, empty_tree.sha1))
81 return &empty_tree;
82 return NULL;
83 }
84
85 int mkdir_in_gitdir(const char *path)
86 {
87 if (mkdir(path, 0777)) {
88 int saved_errno = errno;
89 struct stat st;
90 struct strbuf sb = STRBUF_INIT;
91
92 if (errno != EEXIST)
93 return -1;
94 /*
95 * Are we looking at a path in a symlinked worktree
96 * whose original repository does not yet have it?
97 * e.g. .git/rr-cache pointing at its original
98 * repository in which the user hasn't performed any
99 * conflict resolution yet?
100 */
101 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
102 strbuf_readlink(&sb, path, st.st_size) ||
103 !is_absolute_path(sb.buf) ||
104 mkdir(sb.buf, 0777)) {
105 strbuf_release(&sb);
106 errno = saved_errno;
107 return -1;
108 }
109 strbuf_release(&sb);
110 }
111 return adjust_shared_perm(path);
112 }
113
114 enum scld_error safe_create_leading_directories(char *path)
115 {
116 char *next_component = path + offset_1st_component(path);
117 enum scld_error ret = SCLD_OK;
118
119 while (ret == SCLD_OK && next_component) {
120 struct stat st;
121 char *slash = next_component, slash_character;
122
123 while (*slash && !is_dir_sep(*slash))
124 slash++;
125
126 if (!*slash)
127 break;
128
129 next_component = slash + 1;
130 while (is_dir_sep(*next_component))
131 next_component++;
132 if (!*next_component)
133 break;
134
135 slash_character = *slash;
136 *slash = '\0';
137 if (!stat(path, &st)) {
138 /* path exists */
139 if (!S_ISDIR(st.st_mode))
140 ret = SCLD_EXISTS;
141 } else if (mkdir(path, 0777)) {
142 if (errno == EEXIST &&
143 !stat(path, &st) && S_ISDIR(st.st_mode))
144 ; /* somebody created it since we checked */
145 else if (errno == ENOENT)
146 /*
147 * Either mkdir() failed because
148 * somebody just pruned the containing
149 * directory, or stat() failed because
150 * the file that was in our way was
151 * just removed. Either way, inform
152 * the caller that it might be worth
153 * trying again:
154 */
155 ret = SCLD_VANISHED;
156 else
157 ret = SCLD_FAILED;
158 } else if (adjust_shared_perm(path)) {
159 ret = SCLD_PERMS;
160 }
161 *slash = slash_character;
162 }
163 return ret;
164 }
165
166 enum scld_error safe_create_leading_directories_const(const char *path)
167 {
168 /* path points to cache entries, so xstrdup before messing with it */
169 char *buf = xstrdup(path);
170 enum scld_error result = safe_create_leading_directories(buf);
171 free(buf);
172 return result;
173 }
174
175 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
176 {
177 int i;
178 for (i = 0; i < 20; i++) {
179 static char hex[] = "0123456789abcdef";
180 unsigned int val = sha1[i];
181 char *pos = pathbuf + i*2 + (i > 0);
182 *pos++ = hex[val >> 4];
183 *pos = hex[val & 0xf];
184 }
185 }
186
187 const char *sha1_file_name(const unsigned char *sha1)
188 {
189 static char buf[PATH_MAX];
190 const char *objdir;
191 int len;
192
193 objdir = get_object_directory();
194 len = strlen(objdir);
195
196 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
197 if (len + 43 > PATH_MAX)
198 die("insanely long object directory %s", objdir);
199 memcpy(buf, objdir, len);
200 buf[len] = '/';
201 buf[len+3] = '/';
202 buf[len+42] = '\0';
203 fill_sha1_path(buf + len + 1, sha1);
204 return buf;
205 }
206
207 /*
208 * Return the name of the pack or index file with the specified sha1
209 * in its filename. *base and *name are scratch space that must be
210 * provided by the caller. which should be "pack" or "idx".
211 */
212 static char *sha1_get_pack_name(const unsigned char *sha1,
213 struct strbuf *buf,
214 const char *which)
215 {
216 strbuf_reset(buf);
217 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
218 sha1_to_hex(sha1), which);
219 return buf->buf;
220 }
221
222 char *sha1_pack_name(const unsigned char *sha1)
223 {
224 static struct strbuf buf = STRBUF_INIT;
225 return sha1_get_pack_name(sha1, &buf, "pack");
226 }
227
228 char *sha1_pack_index_name(const unsigned char *sha1)
229 {
230 static struct strbuf buf = STRBUF_INIT;
231 return sha1_get_pack_name(sha1, &buf, "idx");
232 }
233
234 struct alternate_object_database *alt_odb_list;
235 static struct alternate_object_database **alt_odb_tail;
236
237 /*
238 * Prepare alternate object database registry.
239 *
240 * The variable alt_odb_list points at the list of struct
241 * alternate_object_database. The elements on this list come from
242 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
243 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
244 * whose contents is similar to that environment variable but can be
245 * LF separated. Its base points at a statically allocated buffer that
246 * contains "/the/directory/corresponding/to/.git/objects/...", while
247 * its name points just after the slash at the end of ".git/objects/"
248 * in the example above, and has enough space to hold 40-byte hex
249 * SHA1, an extra slash for the first level indirection, and the
250 * terminating NUL.
251 */
252 static int link_alt_odb_entry(const char *entry, const char *relative_base,
253 int depth, const char *normalized_objdir)
254 {
255 struct alternate_object_database *ent;
256 struct alternate_object_database *alt;
257 size_t pfxlen, entlen;
258 struct strbuf pathbuf = STRBUF_INIT;
259
260 if (!is_absolute_path(entry) && relative_base) {
261 strbuf_addstr(&pathbuf, real_path(relative_base));
262 strbuf_addch(&pathbuf, '/');
263 }
264 strbuf_addstr(&pathbuf, entry);
265
266 normalize_path_copy(pathbuf.buf, pathbuf.buf);
267
268 pfxlen = strlen(pathbuf.buf);
269
270 /*
271 * The trailing slash after the directory name is given by
272 * this function at the end. Remove duplicates.
273 */
274 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
275 pfxlen -= 1;
276
277 entlen = st_add(pfxlen, 43); /* '/' + 2 hex + '/' + 38 hex + NUL */
278 ent = xmalloc(st_add(sizeof(*ent), entlen));
279 memcpy(ent->base, pathbuf.buf, pfxlen);
280 strbuf_release(&pathbuf);
281
282 ent->name = ent->base + pfxlen + 1;
283 ent->base[pfxlen + 3] = '/';
284 ent->base[pfxlen] = ent->base[entlen-1] = 0;
285
286 /* Detect cases where alternate disappeared */
287 if (!is_directory(ent->base)) {
288 error("object directory %s does not exist; "
289 "check .git/objects/info/alternates.",
290 ent->base);
291 free(ent);
292 return -1;
293 }
294
295 /* Prevent the common mistake of listing the same
296 * thing twice, or object directory itself.
297 */
298 for (alt = alt_odb_list; alt; alt = alt->next) {
299 if (pfxlen == alt->name - alt->base - 1 &&
300 !memcmp(ent->base, alt->base, pfxlen)) {
301 free(ent);
302 return -1;
303 }
304 }
305 if (!fspathcmp(ent->base, normalized_objdir)) {
306 free(ent);
307 return -1;
308 }
309
310 /* add the alternate entry */
311 *alt_odb_tail = ent;
312 alt_odb_tail = &(ent->next);
313 ent->next = NULL;
314
315 /* recursively add alternates */
316 read_info_alternates(ent->base, depth + 1);
317
318 ent->base[pfxlen] = '/';
319
320 return 0;
321 }
322
323 static void link_alt_odb_entries(const char *alt, int len, int sep,
324 const char *relative_base, int depth)
325 {
326 struct string_list entries = STRING_LIST_INIT_NODUP;
327 char *alt_copy;
328 int i;
329 struct strbuf objdirbuf = STRBUF_INIT;
330
331 if (depth > 5) {
332 error("%s: ignoring alternate object stores, nesting too deep.",
333 relative_base);
334 return;
335 }
336
337 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
338 normalize_path_copy(objdirbuf.buf, objdirbuf.buf);
339
340 alt_copy = xmemdupz(alt, len);
341 string_list_split_in_place(&entries, alt_copy, sep, -1);
342 for (i = 0; i < entries.nr; i++) {
343 const char *entry = entries.items[i].string;
344 if (entry[0] == '\0' || entry[0] == '#')
345 continue;
346 if (!is_absolute_path(entry) && depth) {
347 error("%s: ignoring relative alternate object store %s",
348 relative_base, entry);
349 } else {
350 link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf);
351 }
352 }
353 string_list_clear(&entries, 0);
354 free(alt_copy);
355 strbuf_release(&objdirbuf);
356 }
357
358 void read_info_alternates(const char * relative_base, int depth)
359 {
360 char *map;
361 size_t mapsz;
362 struct stat st;
363 char *path;
364 int fd;
365
366 path = xstrfmt("%s/info/alternates", relative_base);
367 fd = git_open_noatime(path);
368 free(path);
369 if (fd < 0)
370 return;
371 if (fstat(fd, &st) || (st.st_size == 0)) {
372 close(fd);
373 return;
374 }
375 mapsz = xsize_t(st.st_size);
376 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
377 close(fd);
378
379 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
380
381 munmap(map, mapsz);
382 }
383
384 void add_to_alternates_file(const char *reference)
385 {
386 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
387 char *alts = git_pathdup("objects/info/alternates");
388 FILE *in, *out;
389
390 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
391 out = fdopen_lock_file(lock, "w");
392 if (!out)
393 die_errno("unable to fdopen alternates lockfile");
394
395 in = fopen(alts, "r");
396 if (in) {
397 struct strbuf line = STRBUF_INIT;
398 int found = 0;
399
400 while (strbuf_getline(&line, in) != EOF) {
401 if (!strcmp(reference, line.buf)) {
402 found = 1;
403 break;
404 }
405 fprintf_or_die(out, "%s\n", line.buf);
406 }
407
408 strbuf_release(&line);
409 fclose(in);
410
411 if (found) {
412 rollback_lock_file(lock);
413 lock = NULL;
414 }
415 }
416 else if (errno != ENOENT)
417 die_errno("unable to read alternates file");
418
419 if (lock) {
420 fprintf_or_die(out, "%s\n", reference);
421 if (commit_lock_file(lock))
422 die_errno("unable to move new alternates file into place");
423 if (alt_odb_tail)
424 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
425 }
426 free(alts);
427 }
428
429 /*
430 * Compute the exact path an alternate is at and returns it. In case of
431 * error NULL is returned and the human readable error is added to `err`
432 * `path` may be relative and should point to $GITDIR.
433 * `err` must not be null.
434 */
435 char *compute_alternate_path(const char *path, struct strbuf *err)
436 {
437 char *ref_git = NULL;
438 const char *repo, *ref_git_s;
439 int seen_error = 0;
440
441 ref_git_s = real_path_if_valid(path);
442 if (!ref_git_s) {
443 seen_error = 1;
444 strbuf_addf(err, _("path '%s' does not exist"), path);
445 goto out;
446 } else
447 /*
448 * Beware: read_gitfile(), real_path() and mkpath()
449 * return static buffer
450 */
451 ref_git = xstrdup(ref_git_s);
452
453 repo = read_gitfile(ref_git);
454 if (!repo)
455 repo = read_gitfile(mkpath("%s/.git", ref_git));
456 if (repo) {
457 free(ref_git);
458 ref_git = xstrdup(repo);
459 }
460
461 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
462 char *ref_git_git = mkpathdup("%s/.git", ref_git);
463 free(ref_git);
464 ref_git = ref_git_git;
465 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
466 struct strbuf sb = STRBUF_INIT;
467 seen_error = 1;
468 if (get_common_dir(&sb, ref_git)) {
469 strbuf_addf(err,
470 _("reference repository '%s' as a linked "
471 "checkout is not supported yet."),
472 path);
473 goto out;
474 }
475
476 strbuf_addf(err, _("reference repository '%s' is not a "
477 "local repository."), path);
478 goto out;
479 }
480
481 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
482 strbuf_addf(err, _("reference repository '%s' is shallow"),
483 path);
484 seen_error = 1;
485 goto out;
486 }
487
488 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
489 strbuf_addf(err,
490 _("reference repository '%s' is grafted"),
491 path);
492 seen_error = 1;
493 goto out;
494 }
495
496 out:
497 if (seen_error) {
498 free(ref_git);
499 ref_git = NULL;
500 }
501
502 return ref_git;
503 }
504
505 int foreach_alt_odb(alt_odb_fn fn, void *cb)
506 {
507 struct alternate_object_database *ent;
508 int r = 0;
509
510 prepare_alt_odb();
511 for (ent = alt_odb_list; ent; ent = ent->next) {
512 r = fn(ent, cb);
513 if (r)
514 break;
515 }
516 return r;
517 }
518
519 void prepare_alt_odb(void)
520 {
521 const char *alt;
522
523 if (alt_odb_tail)
524 return;
525
526 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
527 if (!alt) alt = "";
528
529 alt_odb_tail = &alt_odb_list;
530 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
531
532 read_info_alternates(get_object_directory(), 0);
533 }
534
535 /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
536 static int freshen_file(const char *fn)
537 {
538 struct utimbuf t;
539 t.actime = t.modtime = time(NULL);
540 return !utime(fn, &t);
541 }
542
543 /*
544 * All of the check_and_freshen functions return 1 if the file exists and was
545 * freshened (if freshening was requested), 0 otherwise. If they return
546 * 0, you should not assume that it is safe to skip a write of the object (it
547 * either does not exist on disk, or has a stale mtime and may be subject to
548 * pruning).
549 */
550 static int check_and_freshen_file(const char *fn, int freshen)
551 {
552 if (access(fn, F_OK))
553 return 0;
554 if (freshen && !freshen_file(fn))
555 return 0;
556 return 1;
557 }
558
559 static int check_and_freshen_local(const unsigned char *sha1, int freshen)
560 {
561 return check_and_freshen_file(sha1_file_name(sha1), freshen);
562 }
563
564 static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
565 {
566 struct alternate_object_database *alt;
567 prepare_alt_odb();
568 for (alt = alt_odb_list; alt; alt = alt->next) {
569 fill_sha1_path(alt->name, sha1);
570 if (check_and_freshen_file(alt->base, freshen))
571 return 1;
572 }
573 return 0;
574 }
575
576 static int check_and_freshen(const unsigned char *sha1, int freshen)
577 {
578 return check_and_freshen_local(sha1, freshen) ||
579 check_and_freshen_nonlocal(sha1, freshen);
580 }
581
582 int has_loose_object_nonlocal(const unsigned char *sha1)
583 {
584 return check_and_freshen_nonlocal(sha1, 0);
585 }
586
587 static int has_loose_object(const unsigned char *sha1)
588 {
589 return check_and_freshen(sha1, 0);
590 }
591
592 static unsigned int pack_used_ctr;
593 static unsigned int pack_mmap_calls;
594 static unsigned int peak_pack_open_windows;
595 static unsigned int pack_open_windows;
596 static unsigned int pack_open_fds;
597 static unsigned int pack_max_fds;
598 static size_t peak_pack_mapped;
599 static size_t pack_mapped;
600 struct packed_git *packed_git;
601
602 static struct mru packed_git_mru_storage;
603 struct mru *packed_git_mru = &packed_git_mru_storage;
604
605 void pack_report(void)
606 {
607 fprintf(stderr,
608 "pack_report: getpagesize() = %10" SZ_FMT "\n"
609 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
610 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
611 sz_fmt(getpagesize()),
612 sz_fmt(packed_git_window_size),
613 sz_fmt(packed_git_limit));
614 fprintf(stderr,
615 "pack_report: pack_used_ctr = %10u\n"
616 "pack_report: pack_mmap_calls = %10u\n"
617 "pack_report: pack_open_windows = %10u / %10u\n"
618 "pack_report: pack_mapped = "
619 "%10" SZ_FMT " / %10" SZ_FMT "\n",
620 pack_used_ctr,
621 pack_mmap_calls,
622 pack_open_windows, peak_pack_open_windows,
623 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
624 }
625
626 /*
627 * Open and mmap the index file at path, perform a couple of
628 * consistency checks, then record its information to p. Return 0 on
629 * success.
630 */
631 static int check_packed_git_idx(const char *path, struct packed_git *p)
632 {
633 void *idx_map;
634 struct pack_idx_header *hdr;
635 size_t idx_size;
636 uint32_t version, nr, i, *index;
637 int fd = git_open_noatime(path);
638 struct stat st;
639
640 if (fd < 0)
641 return -1;
642 if (fstat(fd, &st)) {
643 close(fd);
644 return -1;
645 }
646 idx_size = xsize_t(st.st_size);
647 if (idx_size < 4 * 256 + 20 + 20) {
648 close(fd);
649 return error("index file %s is too small", path);
650 }
651 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
652 close(fd);
653
654 hdr = idx_map;
655 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
656 version = ntohl(hdr->idx_version);
657 if (version < 2 || version > 2) {
658 munmap(idx_map, idx_size);
659 return error("index file %s is version %"PRIu32
660 " and is not supported by this binary"
661 " (try upgrading GIT to a newer version)",
662 path, version);
663 }
664 } else
665 version = 1;
666
667 nr = 0;
668 index = idx_map;
669 if (version > 1)
670 index += 2; /* skip index header */
671 for (i = 0; i < 256; i++) {
672 uint32_t n = ntohl(index[i]);
673 if (n < nr) {
674 munmap(idx_map, idx_size);
675 return error("non-monotonic index %s", path);
676 }
677 nr = n;
678 }
679
680 if (version == 1) {
681 /*
682 * Total size:
683 * - 256 index entries 4 bytes each
684 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
685 * - 20-byte SHA1 of the packfile
686 * - 20-byte SHA1 file checksum
687 */
688 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
689 munmap(idx_map, idx_size);
690 return error("wrong index v1 file size in %s", path);
691 }
692 } else if (version == 2) {
693 /*
694 * Minimum size:
695 * - 8 bytes of header
696 * - 256 index entries 4 bytes each
697 * - 20-byte sha1 entry * nr
698 * - 4-byte crc entry * nr
699 * - 4-byte offset entry * nr
700 * - 20-byte SHA1 of the packfile
701 * - 20-byte SHA1 file checksum
702 * And after the 4-byte offset table might be a
703 * variable sized table containing 8-byte entries
704 * for offsets larger than 2^31.
705 */
706 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
707 unsigned long max_size = min_size;
708 if (nr)
709 max_size += (nr - 1)*8;
710 if (idx_size < min_size || idx_size > max_size) {
711 munmap(idx_map, idx_size);
712 return error("wrong index v2 file size in %s", path);
713 }
714 if (idx_size != min_size &&
715 /*
716 * make sure we can deal with large pack offsets.
717 * 31-bit signed offset won't be enough, neither
718 * 32-bit unsigned one will be.
719 */
720 (sizeof(off_t) <= 4)) {
721 munmap(idx_map, idx_size);
722 return error("pack too large for current definition of off_t in %s", path);
723 }
724 }
725
726 p->index_version = version;
727 p->index_data = idx_map;
728 p->index_size = idx_size;
729 p->num_objects = nr;
730 return 0;
731 }
732
733 int open_pack_index(struct packed_git *p)
734 {
735 char *idx_name;
736 size_t len;
737 int ret;
738
739 if (p->index_data)
740 return 0;
741
742 if (!strip_suffix(p->pack_name, ".pack", &len))
743 die("BUG: pack_name does not end in .pack");
744 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
745 ret = check_packed_git_idx(idx_name, p);
746 free(idx_name);
747 return ret;
748 }
749
750 static void scan_windows(struct packed_git *p,
751 struct packed_git **lru_p,
752 struct pack_window **lru_w,
753 struct pack_window **lru_l)
754 {
755 struct pack_window *w, *w_l;
756
757 for (w_l = NULL, w = p->windows; w; w = w->next) {
758 if (!w->inuse_cnt) {
759 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
760 *lru_p = p;
761 *lru_w = w;
762 *lru_l = w_l;
763 }
764 }
765 w_l = w;
766 }
767 }
768
769 static int unuse_one_window(struct packed_git *current)
770 {
771 struct packed_git *p, *lru_p = NULL;
772 struct pack_window *lru_w = NULL, *lru_l = NULL;
773
774 if (current)
775 scan_windows(current, &lru_p, &lru_w, &lru_l);
776 for (p = packed_git; p; p = p->next)
777 scan_windows(p, &lru_p, &lru_w, &lru_l);
778 if (lru_p) {
779 munmap(lru_w->base, lru_w->len);
780 pack_mapped -= lru_w->len;
781 if (lru_l)
782 lru_l->next = lru_w->next;
783 else
784 lru_p->windows = lru_w->next;
785 free(lru_w);
786 pack_open_windows--;
787 return 1;
788 }
789 return 0;
790 }
791
792 void release_pack_memory(size_t need)
793 {
794 size_t cur = pack_mapped;
795 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
796 ; /* nothing */
797 }
798
799 static void mmap_limit_check(size_t length)
800 {
801 static size_t limit = 0;
802 if (!limit) {
803 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
804 if (!limit)
805 limit = SIZE_MAX;
806 }
807 if (length > limit)
808 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
809 (uintmax_t)length, (uintmax_t)limit);
810 }
811
812 void *xmmap_gently(void *start, size_t length,
813 int prot, int flags, int fd, off_t offset)
814 {
815 void *ret;
816
817 mmap_limit_check(length);
818 ret = mmap(start, length, prot, flags, fd, offset);
819 if (ret == MAP_FAILED) {
820 if (!length)
821 return NULL;
822 release_pack_memory(length);
823 ret = mmap(start, length, prot, flags, fd, offset);
824 }
825 return ret;
826 }
827
828 void *xmmap(void *start, size_t length,
829 int prot, int flags, int fd, off_t offset)
830 {
831 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
832 if (ret == MAP_FAILED)
833 die_errno("mmap failed");
834 return ret;
835 }
836
837 void close_pack_windows(struct packed_git *p)
838 {
839 while (p->windows) {
840 struct pack_window *w = p->windows;
841
842 if (w->inuse_cnt)
843 die("pack '%s' still has open windows to it",
844 p->pack_name);
845 munmap(w->base, w->len);
846 pack_mapped -= w->len;
847 pack_open_windows--;
848 p->windows = w->next;
849 free(w);
850 }
851 }
852
853 static int close_pack_fd(struct packed_git *p)
854 {
855 if (p->pack_fd < 0)
856 return 0;
857
858 close(p->pack_fd);
859 pack_open_fds--;
860 p->pack_fd = -1;
861
862 return 1;
863 }
864
865 static void close_pack(struct packed_git *p)
866 {
867 close_pack_windows(p);
868 close_pack_fd(p);
869 close_pack_index(p);
870 }
871
872 void close_all_packs(void)
873 {
874 struct packed_git *p;
875
876 for (p = packed_git; p; p = p->next)
877 if (p->do_not_close)
878 die("BUG: want to close pack marked 'do-not-close'");
879 else
880 close_pack(p);
881 }
882
883
884 /*
885 * The LRU pack is the one with the oldest MRU window, preferring packs
886 * with no used windows, or the oldest mtime if it has no windows allocated.
887 */
888 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
889 {
890 struct pack_window *w, *this_mru_w;
891 int has_windows_inuse = 0;
892
893 /*
894 * Reject this pack if it has windows and the previously selected
895 * one does not. If this pack does not have windows, reject
896 * it if the pack file is newer than the previously selected one.
897 */
898 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
899 return;
900
901 for (w = this_mru_w = p->windows; w; w = w->next) {
902 /*
903 * Reject this pack if any of its windows are in use,
904 * but the previously selected pack did not have any
905 * inuse windows. Otherwise, record that this pack
906 * has windows in use.
907 */
908 if (w->inuse_cnt) {
909 if (*accept_windows_inuse)
910 has_windows_inuse = 1;
911 else
912 return;
913 }
914
915 if (w->last_used > this_mru_w->last_used)
916 this_mru_w = w;
917
918 /*
919 * Reject this pack if it has windows that have been
920 * used more recently than the previously selected pack.
921 * If the previously selected pack had windows inuse and
922 * we have not encountered a window in this pack that is
923 * inuse, skip this check since we prefer a pack with no
924 * inuse windows to one that has inuse windows.
925 */
926 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
927 this_mru_w->last_used > (*mru_w)->last_used)
928 return;
929 }
930
931 /*
932 * Select this pack.
933 */
934 *mru_w = this_mru_w;
935 *lru_p = p;
936 *accept_windows_inuse = has_windows_inuse;
937 }
938
939 static int close_one_pack(void)
940 {
941 struct packed_git *p, *lru_p = NULL;
942 struct pack_window *mru_w = NULL;
943 int accept_windows_inuse = 1;
944
945 for (p = packed_git; p; p = p->next) {
946 if (p->pack_fd == -1)
947 continue;
948 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
949 }
950
951 if (lru_p)
952 return close_pack_fd(lru_p);
953
954 return 0;
955 }
956
957 void unuse_pack(struct pack_window **w_cursor)
958 {
959 struct pack_window *w = *w_cursor;
960 if (w) {
961 w->inuse_cnt--;
962 *w_cursor = NULL;
963 }
964 }
965
966 void close_pack_index(struct packed_git *p)
967 {
968 if (p->index_data) {
969 munmap((void *)p->index_data, p->index_size);
970 p->index_data = NULL;
971 }
972 }
973
974 static unsigned int get_max_fd_limit(void)
975 {
976 #ifdef RLIMIT_NOFILE
977 {
978 struct rlimit lim;
979
980 if (!getrlimit(RLIMIT_NOFILE, &lim))
981 return lim.rlim_cur;
982 }
983 #endif
984
985 #ifdef _SC_OPEN_MAX
986 {
987 long open_max = sysconf(_SC_OPEN_MAX);
988 if (0 < open_max)
989 return open_max;
990 /*
991 * Otherwise, we got -1 for one of the two
992 * reasons:
993 *
994 * (1) sysconf() did not understand _SC_OPEN_MAX
995 * and signaled an error with -1; or
996 * (2) sysconf() said there is no limit.
997 *
998 * We _could_ clear errno before calling sysconf() to
999 * tell these two cases apart and return a huge number
1000 * in the latter case to let the caller cap it to a
1001 * value that is not so selfish, but letting the
1002 * fallback OPEN_MAX codepath take care of these cases
1003 * is a lot simpler.
1004 */
1005 }
1006 #endif
1007
1008 #ifdef OPEN_MAX
1009 return OPEN_MAX;
1010 #else
1011 return 1; /* see the caller ;-) */
1012 #endif
1013 }
1014
1015 /*
1016 * Do not call this directly as this leaks p->pack_fd on error return;
1017 * call open_packed_git() instead.
1018 */
1019 static int open_packed_git_1(struct packed_git *p)
1020 {
1021 struct stat st;
1022 struct pack_header hdr;
1023 unsigned char sha1[20];
1024 unsigned char *idx_sha1;
1025 long fd_flag;
1026
1027 if (!p->index_data && open_pack_index(p))
1028 return error("packfile %s index unavailable", p->pack_name);
1029
1030 if (!pack_max_fds) {
1031 unsigned int max_fds = get_max_fd_limit();
1032
1033 /* Save 3 for stdin/stdout/stderr, 22 for work */
1034 if (25 < max_fds)
1035 pack_max_fds = max_fds - 25;
1036 else
1037 pack_max_fds = 1;
1038 }
1039
1040 while (pack_max_fds <= pack_open_fds && close_one_pack())
1041 ; /* nothing */
1042
1043 p->pack_fd = git_open_noatime(p->pack_name);
1044 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
1045 return -1;
1046 pack_open_fds++;
1047
1048 /* If we created the struct before we had the pack we lack size. */
1049 if (!p->pack_size) {
1050 if (!S_ISREG(st.st_mode))
1051 return error("packfile %s not a regular file", p->pack_name);
1052 p->pack_size = st.st_size;
1053 } else if (p->pack_size != st.st_size)
1054 return error("packfile %s size changed", p->pack_name);
1055
1056 /* We leave these file descriptors open with sliding mmap;
1057 * there is no point keeping them open across exec(), though.
1058 */
1059 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
1060 if (fd_flag < 0)
1061 return error("cannot determine file descriptor flags");
1062 fd_flag |= FD_CLOEXEC;
1063 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
1064 return error("cannot set FD_CLOEXEC");
1065
1066 /* Verify we recognize this pack file format. */
1067 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
1068 return error("file %s is far too short to be a packfile", p->pack_name);
1069 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
1070 return error("file %s is not a GIT packfile", p->pack_name);
1071 if (!pack_version_ok(hdr.hdr_version))
1072 return error("packfile %s is version %"PRIu32" and not"
1073 " supported (try upgrading GIT to a newer version)",
1074 p->pack_name, ntohl(hdr.hdr_version));
1075
1076 /* Verify the pack matches its index. */
1077 if (p->num_objects != ntohl(hdr.hdr_entries))
1078 return error("packfile %s claims to have %"PRIu32" objects"
1079 " while index indicates %"PRIu32" objects",
1080 p->pack_name, ntohl(hdr.hdr_entries),
1081 p->num_objects);
1082 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
1083 return error("end of packfile %s is unavailable", p->pack_name);
1084 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
1085 return error("packfile %s signature is unavailable", p->pack_name);
1086 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
1087 if (hashcmp(sha1, idx_sha1))
1088 return error("packfile %s does not match index", p->pack_name);
1089 return 0;
1090 }
1091
1092 static int open_packed_git(struct packed_git *p)
1093 {
1094 if (!open_packed_git_1(p))
1095 return 0;
1096 close_pack_fd(p);
1097 return -1;
1098 }
1099
1100 static int in_window(struct pack_window *win, off_t offset)
1101 {
1102 /* We must promise at least 20 bytes (one hash) after the
1103 * offset is available from this window, otherwise the offset
1104 * is not actually in this window and a different window (which
1105 * has that one hash excess) must be used. This is to support
1106 * the object header and delta base parsing routines below.
1107 */
1108 off_t win_off = win->offset;
1109 return win_off <= offset
1110 && (offset + 20) <= (win_off + win->len);
1111 }
1112
1113 unsigned char *use_pack(struct packed_git *p,
1114 struct pack_window **w_cursor,
1115 off_t offset,
1116 unsigned long *left)
1117 {
1118 struct pack_window *win = *w_cursor;
1119
1120 /* Since packfiles end in a hash of their content and it's
1121 * pointless to ask for an offset into the middle of that
1122 * hash, and the in_window function above wouldn't match
1123 * don't allow an offset too close to the end of the file.
1124 */
1125 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1126 die("packfile %s cannot be accessed", p->pack_name);
1127 if (offset > (p->pack_size - 20))
1128 die("offset beyond end of packfile (truncated pack?)");
1129 if (offset < 0)
1130 die(_("offset before end of packfile (broken .idx?)"));
1131
1132 if (!win || !in_window(win, offset)) {
1133 if (win)
1134 win->inuse_cnt--;
1135 for (win = p->windows; win; win = win->next) {
1136 if (in_window(win, offset))
1137 break;
1138 }
1139 if (!win) {
1140 size_t window_align = packed_git_window_size / 2;
1141 off_t len;
1142
1143 if (p->pack_fd == -1 && open_packed_git(p))
1144 die("packfile %s cannot be accessed", p->pack_name);
1145
1146 win = xcalloc(1, sizeof(*win));
1147 win->offset = (offset / window_align) * window_align;
1148 len = p->pack_size - win->offset;
1149 if (len > packed_git_window_size)
1150 len = packed_git_window_size;
1151 win->len = (size_t)len;
1152 pack_mapped += win->len;
1153 while (packed_git_limit < pack_mapped
1154 && unuse_one_window(p))
1155 ; /* nothing */
1156 win->base = xmmap(NULL, win->len,
1157 PROT_READ, MAP_PRIVATE,
1158 p->pack_fd, win->offset);
1159 if (win->base == MAP_FAILED)
1160 die_errno("packfile %s cannot be mapped",
1161 p->pack_name);
1162 if (!win->offset && win->len == p->pack_size
1163 && !p->do_not_close)
1164 close_pack_fd(p);
1165 pack_mmap_calls++;
1166 pack_open_windows++;
1167 if (pack_mapped > peak_pack_mapped)
1168 peak_pack_mapped = pack_mapped;
1169 if (pack_open_windows > peak_pack_open_windows)
1170 peak_pack_open_windows = pack_open_windows;
1171 win->next = p->windows;
1172 p->windows = win;
1173 }
1174 }
1175 if (win != *w_cursor) {
1176 win->last_used = pack_used_ctr++;
1177 win->inuse_cnt++;
1178 *w_cursor = win;
1179 }
1180 offset -= win->offset;
1181 if (left)
1182 *left = win->len - xsize_t(offset);
1183 return win->base + offset;
1184 }
1185
1186 static struct packed_git *alloc_packed_git(int extra)
1187 {
1188 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
1189 memset(p, 0, sizeof(*p));
1190 p->pack_fd = -1;
1191 return p;
1192 }
1193
1194 static void try_to_free_pack_memory(size_t size)
1195 {
1196 release_pack_memory(size);
1197 }
1198
1199 struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1200 {
1201 static int have_set_try_to_free_routine;
1202 struct stat st;
1203 size_t alloc;
1204 struct packed_git *p;
1205
1206 if (!have_set_try_to_free_routine) {
1207 have_set_try_to_free_routine = 1;
1208 set_try_to_free_routine(try_to_free_pack_memory);
1209 }
1210
1211 /*
1212 * Make sure a corresponding .pack file exists and that
1213 * the index looks sane.
1214 */
1215 if (!strip_suffix_mem(path, &path_len, ".idx"))
1216 return NULL;
1217
1218 /*
1219 * ".pack" is long enough to hold any suffix we're adding (and
1220 * the use xsnprintf double-checks that)
1221 */
1222 alloc = st_add3(path_len, strlen(".pack"), 1);
1223 p = alloc_packed_git(alloc);
1224 memcpy(p->pack_name, path, path_len);
1225
1226 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
1227 if (!access(p->pack_name, F_OK))
1228 p->pack_keep = 1;
1229
1230 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
1231 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
1232 free(p);
1233 return NULL;
1234 }
1235
1236 /* ok, it looks sane as far as we can check without
1237 * actually mapping the pack file.
1238 */
1239 p->pack_size = st.st_size;
1240 p->pack_local = local;
1241 p->mtime = st.st_mtime;
1242 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1243 hashclr(p->sha1);
1244 return p;
1245 }
1246
1247 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
1248 {
1249 const char *path = sha1_pack_name(sha1);
1250 size_t alloc = st_add(strlen(path), 1);
1251 struct packed_git *p = alloc_packed_git(alloc);
1252
1253 memcpy(p->pack_name, path, alloc); /* includes NUL */
1254 hashcpy(p->sha1, sha1);
1255 if (check_packed_git_idx(idx_path, p)) {
1256 free(p);
1257 return NULL;
1258 }
1259
1260 return p;
1261 }
1262
1263 void install_packed_git(struct packed_git *pack)
1264 {
1265 if (pack->pack_fd != -1)
1266 pack_open_fds++;
1267
1268 pack->next = packed_git;
1269 packed_git = pack;
1270 }
1271
1272 void (*report_garbage)(unsigned seen_bits, const char *path);
1273
1274 static void report_helper(const struct string_list *list,
1275 int seen_bits, int first, int last)
1276 {
1277 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
1278 return;
1279
1280 for (; first < last; first++)
1281 report_garbage(seen_bits, list->items[first].string);
1282 }
1283
1284 static void report_pack_garbage(struct string_list *list)
1285 {
1286 int i, baselen = -1, first = 0, seen_bits = 0;
1287
1288 if (!report_garbage)
1289 return;
1290
1291 string_list_sort(list);
1292
1293 for (i = 0; i < list->nr; i++) {
1294 const char *path = list->items[i].string;
1295 if (baselen != -1 &&
1296 strncmp(path, list->items[first].string, baselen)) {
1297 report_helper(list, seen_bits, first, i);
1298 baselen = -1;
1299 seen_bits = 0;
1300 }
1301 if (baselen == -1) {
1302 const char *dot = strrchr(path, '.');
1303 if (!dot) {
1304 report_garbage(PACKDIR_FILE_GARBAGE, path);
1305 continue;
1306 }
1307 baselen = dot - path + 1;
1308 first = i;
1309 }
1310 if (!strcmp(path + baselen, "pack"))
1311 seen_bits |= 1;
1312 else if (!strcmp(path + baselen, "idx"))
1313 seen_bits |= 2;
1314 }
1315 report_helper(list, seen_bits, first, list->nr);
1316 }
1317
1318 static void prepare_packed_git_one(char *objdir, int local)
1319 {
1320 struct strbuf path = STRBUF_INIT;
1321 size_t dirnamelen;
1322 DIR *dir;
1323 struct dirent *de;
1324 struct string_list garbage = STRING_LIST_INIT_DUP;
1325
1326 strbuf_addstr(&path, objdir);
1327 strbuf_addstr(&path, "/pack");
1328 dir = opendir(path.buf);
1329 if (!dir) {
1330 if (errno != ENOENT)
1331 error_errno("unable to open object pack directory: %s",
1332 path.buf);
1333 strbuf_release(&path);
1334 return;
1335 }
1336 strbuf_addch(&path, '/');
1337 dirnamelen = path.len;
1338 while ((de = readdir(dir)) != NULL) {
1339 struct packed_git *p;
1340 size_t base_len;
1341
1342 if (is_dot_or_dotdot(de->d_name))
1343 continue;
1344
1345 strbuf_setlen(&path, dirnamelen);
1346 strbuf_addstr(&path, de->d_name);
1347
1348 base_len = path.len;
1349 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
1350 /* Don't reopen a pack we already have. */
1351 for (p = packed_git; p; p = p->next) {
1352 size_t len;
1353 if (strip_suffix(p->pack_name, ".pack", &len) &&
1354 len == base_len &&
1355 !memcmp(p->pack_name, path.buf, len))
1356 break;
1357 }
1358 if (p == NULL &&
1359 /*
1360 * See if it really is a valid .idx file with
1361 * corresponding .pack file that we can map.
1362 */
1363 (p = add_packed_git(path.buf, path.len, local)) != NULL)
1364 install_packed_git(p);
1365 }
1366
1367 if (!report_garbage)
1368 continue;
1369
1370 if (ends_with(de->d_name, ".idx") ||
1371 ends_with(de->d_name, ".pack") ||
1372 ends_with(de->d_name, ".bitmap") ||
1373 ends_with(de->d_name, ".keep"))
1374 string_list_append(&garbage, path.buf);
1375 else
1376 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1377 }
1378 closedir(dir);
1379 report_pack_garbage(&garbage);
1380 string_list_clear(&garbage, 0);
1381 strbuf_release(&path);
1382 }
1383
1384 static void *get_next_packed_git(const void *p)
1385 {
1386 return ((const struct packed_git *)p)->next;
1387 }
1388
1389 static void set_next_packed_git(void *p, void *next)
1390 {
1391 ((struct packed_git *)p)->next = next;
1392 }
1393
1394 static int sort_pack(const void *a_, const void *b_)
1395 {
1396 const struct packed_git *a = a_;
1397 const struct packed_git *b = b_;
1398 int st;
1399
1400 /*
1401 * Local packs tend to contain objects specific to our
1402 * variant of the project than remote ones. In addition,
1403 * remote ones could be on a network mounted filesystem.
1404 * Favor local ones for these reasons.
1405 */
1406 st = a->pack_local - b->pack_local;
1407 if (st)
1408 return -st;
1409
1410 /*
1411 * Younger packs tend to contain more recent objects,
1412 * and more recent objects tend to get accessed more
1413 * often.
1414 */
1415 if (a->mtime < b->mtime)
1416 return 1;
1417 else if (a->mtime == b->mtime)
1418 return 0;
1419 return -1;
1420 }
1421
1422 static void rearrange_packed_git(void)
1423 {
1424 packed_git = llist_mergesort(packed_git, get_next_packed_git,
1425 set_next_packed_git, sort_pack);
1426 }
1427
1428 static void prepare_packed_git_mru(void)
1429 {
1430 struct packed_git *p;
1431
1432 mru_clear(packed_git_mru);
1433 for (p = packed_git; p; p = p->next)
1434 mru_append(packed_git_mru, p);
1435 }
1436
1437 static int prepare_packed_git_run_once = 0;
1438 void prepare_packed_git(void)
1439 {
1440 struct alternate_object_database *alt;
1441
1442 if (prepare_packed_git_run_once)
1443 return;
1444 prepare_packed_git_one(get_object_directory(), 1);
1445 prepare_alt_odb();
1446 for (alt = alt_odb_list; alt; alt = alt->next) {
1447 alt->name[-1] = 0;
1448 prepare_packed_git_one(alt->base, 0);
1449 alt->name[-1] = '/';
1450 }
1451 rearrange_packed_git();
1452 prepare_packed_git_mru();
1453 prepare_packed_git_run_once = 1;
1454 }
1455
1456 void reprepare_packed_git(void)
1457 {
1458 prepare_packed_git_run_once = 0;
1459 prepare_packed_git();
1460 }
1461
1462 static void mark_bad_packed_object(struct packed_git *p,
1463 const unsigned char *sha1)
1464 {
1465 unsigned i;
1466 for (i = 0; i < p->num_bad_objects; i++)
1467 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
1468 return;
1469 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1470 st_mult(GIT_SHA1_RAWSZ,
1471 st_add(p->num_bad_objects, 1)));
1472 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
1473 p->num_bad_objects++;
1474 }
1475
1476 static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1477 {
1478 struct packed_git *p;
1479 unsigned i;
1480
1481 for (p = packed_git; p; p = p->next)
1482 for (i = 0; i < p->num_bad_objects; i++)
1483 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1484 return p;
1485 return NULL;
1486 }
1487
1488 /*
1489 * With an in-core object data in "map", rehash it to make sure the
1490 * object name actually matches "sha1" to detect object corruption.
1491 * With "map" == NULL, try reading the object named with "sha1" using
1492 * the streaming interface and rehash it to do the same.
1493 */
1494 int check_sha1_signature(const unsigned char *sha1, void *map,
1495 unsigned long size, const char *type)
1496 {
1497 unsigned char real_sha1[20];
1498 enum object_type obj_type;
1499 struct git_istream *st;
1500 git_SHA_CTX c;
1501 char hdr[32];
1502 int hdrlen;
1503
1504 if (map) {
1505 hash_sha1_file(map, size, type, real_sha1);
1506 return hashcmp(sha1, real_sha1) ? -1 : 0;
1507 }
1508
1509 st = open_istream(sha1, &obj_type, &size, NULL);
1510 if (!st)
1511 return -1;
1512
1513 /* Generate the header */
1514 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
1515
1516 /* Sha1.. */
1517 git_SHA1_Init(&c);
1518 git_SHA1_Update(&c, hdr, hdrlen);
1519 for (;;) {
1520 char buf[1024 * 16];
1521 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1522
1523 if (readlen < 0) {
1524 close_istream(st);
1525 return -1;
1526 }
1527 if (!readlen)
1528 break;
1529 git_SHA1_Update(&c, buf, readlen);
1530 }
1531 git_SHA1_Final(real_sha1, &c);
1532 close_istream(st);
1533 return hashcmp(sha1, real_sha1) ? -1 : 0;
1534 }
1535
1536 int git_open_noatime(const char *name)
1537 {
1538 static int sha1_file_open_flag = O_NOATIME;
1539
1540 for (;;) {
1541 int fd;
1542
1543 errno = 0;
1544 fd = open(name, O_RDONLY | sha1_file_open_flag);
1545 if (fd >= 0)
1546 return fd;
1547
1548 /* Might the failure be due to O_NOATIME? */
1549 if (errno != ENOENT && sha1_file_open_flag) {
1550 sha1_file_open_flag = 0;
1551 continue;
1552 }
1553
1554 return -1;
1555 }
1556 }
1557
1558 static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1559 {
1560 struct alternate_object_database *alt;
1561
1562 if (!lstat(sha1_file_name(sha1), st))
1563 return 0;
1564
1565 prepare_alt_odb();
1566 errno = ENOENT;
1567 for (alt = alt_odb_list; alt; alt = alt->next) {
1568 fill_sha1_path(alt->name, sha1);
1569 if (!lstat(alt->base, st))
1570 return 0;
1571 }
1572
1573 return -1;
1574 }
1575
1576 static int open_sha1_file(const unsigned char *sha1)
1577 {
1578 int fd;
1579 struct alternate_object_database *alt;
1580 int most_interesting_errno;
1581
1582 fd = git_open_noatime(sha1_file_name(sha1));
1583 if (fd >= 0)
1584 return fd;
1585 most_interesting_errno = errno;
1586
1587 prepare_alt_odb();
1588 for (alt = alt_odb_list; alt; alt = alt->next) {
1589 fill_sha1_path(alt->name, sha1);
1590 fd = git_open_noatime(alt->base);
1591 if (fd >= 0)
1592 return fd;
1593 if (most_interesting_errno == ENOENT)
1594 most_interesting_errno = errno;
1595 }
1596 errno = most_interesting_errno;
1597 return -1;
1598 }
1599
1600 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1601 {
1602 void *map;
1603 int fd;
1604
1605 fd = open_sha1_file(sha1);
1606 map = NULL;
1607 if (fd >= 0) {
1608 struct stat st;
1609
1610 if (!fstat(fd, &st)) {
1611 *size = xsize_t(st.st_size);
1612 if (!*size) {
1613 /* mmap() is forbidden on empty files */
1614 error("object file %s is empty", sha1_file_name(sha1));
1615 return NULL;
1616 }
1617 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1618 }
1619 close(fd);
1620 }
1621 return map;
1622 }
1623
1624 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1625 unsigned long len, enum object_type *type, unsigned long *sizep)
1626 {
1627 unsigned shift;
1628 unsigned long size, c;
1629 unsigned long used = 0;
1630
1631 c = buf[used++];
1632 *type = (c >> 4) & 7;
1633 size = c & 15;
1634 shift = 4;
1635 while (c & 0x80) {
1636 if (len <= used || bitsizeof(long) <= shift) {
1637 error("bad object header");
1638 size = used = 0;
1639 break;
1640 }
1641 c = buf[used++];
1642 size += (c & 0x7f) << shift;
1643 shift += 7;
1644 }
1645 *sizep = size;
1646 return used;
1647 }
1648
1649 int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1650 {
1651 /* Get the data stream */
1652 memset(stream, 0, sizeof(*stream));
1653 stream->next_in = map;
1654 stream->avail_in = mapsize;
1655 stream->next_out = buffer;
1656 stream->avail_out = bufsiz;
1657
1658 git_inflate_init(stream);
1659 return git_inflate(stream, 0);
1660 }
1661
1662 static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1663 unsigned long mapsize, void *buffer,
1664 unsigned long bufsiz, struct strbuf *header)
1665 {
1666 int status;
1667
1668 status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
1669
1670 /*
1671 * Check if entire header is unpacked in the first iteration.
1672 */
1673 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1674 return 0;
1675
1676 /*
1677 * buffer[0..bufsiz] was not large enough. Copy the partial
1678 * result out to header, and then append the result of further
1679 * reading the stream.
1680 */
1681 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1682 stream->next_out = buffer;
1683 stream->avail_out = bufsiz;
1684
1685 do {
1686 status = git_inflate(stream, 0);
1687 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1688 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1689 return 0;
1690 stream->next_out = buffer;
1691 stream->avail_out = bufsiz;
1692 } while (status != Z_STREAM_END);
1693 return -1;
1694 }
1695
1696 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1697 {
1698 int bytes = strlen(buffer) + 1;
1699 unsigned char *buf = xmallocz(size);
1700 unsigned long n;
1701 int status = Z_OK;
1702
1703 n = stream->total_out - bytes;
1704 if (n > size)
1705 n = size;
1706 memcpy(buf, (char *) buffer + bytes, n);
1707 bytes = n;
1708 if (bytes <= size) {
1709 /*
1710 * The above condition must be (bytes <= size), not
1711 * (bytes < size). In other words, even though we
1712 * expect no more output and set avail_out to zero,
1713 * the input zlib stream may have bytes that express
1714 * "this concludes the stream", and we *do* want to
1715 * eat that input.
1716 *
1717 * Otherwise we would not be able to test that we
1718 * consumed all the input to reach the expected size;
1719 * we also want to check that zlib tells us that all
1720 * went well with status == Z_STREAM_END at the end.
1721 */
1722 stream->next_out = buf + bytes;
1723 stream->avail_out = size - bytes;
1724 while (status == Z_OK)
1725 status = git_inflate(stream, Z_FINISH);
1726 }
1727 if (status == Z_STREAM_END && !stream->avail_in) {
1728 git_inflate_end(stream);
1729 return buf;
1730 }
1731
1732 if (status < 0)
1733 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1734 else if (stream->avail_in)
1735 error("garbage at end of loose object '%s'",
1736 sha1_to_hex(sha1));
1737 free(buf);
1738 return NULL;
1739 }
1740
1741 /*
1742 * We used to just use "sscanf()", but that's actually way
1743 * too permissive for what we want to check. So do an anal
1744 * object header parse by hand.
1745 */
1746 static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1747 unsigned int flags)
1748 {
1749 const char *type_buf = hdr;
1750 unsigned long size;
1751 int type, type_len = 0;
1752
1753 /*
1754 * The type can be of any size but is followed by
1755 * a space.
1756 */
1757 for (;;) {
1758 char c = *hdr++;
1759 if (c == ' ')
1760 break;
1761 type_len++;
1762 }
1763
1764 type = type_from_string_gently(type_buf, type_len, 1);
1765 if (oi->typename)
1766 strbuf_add(oi->typename, type_buf, type_len);
1767 /*
1768 * Set type to 0 if its an unknown object and
1769 * we're obtaining the type using '--allow-unknown-type'
1770 * option.
1771 */
1772 if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
1773 type = 0;
1774 else if (type < 0)
1775 die("invalid object type");
1776 if (oi->typep)
1777 *oi->typep = type;
1778
1779 /*
1780 * The length must follow immediately, and be in canonical
1781 * decimal format (ie "010" is not valid).
1782 */
1783 size = *hdr++ - '0';
1784 if (size > 9)
1785 return -1;
1786 if (size) {
1787 for (;;) {
1788 unsigned long c = *hdr - '0';
1789 if (c > 9)
1790 break;
1791 hdr++;
1792 size = size * 10 + c;
1793 }
1794 }
1795
1796 if (oi->sizep)
1797 *oi->sizep = size;
1798
1799 /*
1800 * The length must be followed by a zero byte
1801 */
1802 return *hdr ? -1 : type;
1803 }
1804
1805 int parse_sha1_header(const char *hdr, unsigned long *sizep)
1806 {
1807 struct object_info oi;
1808
1809 oi.sizep = sizep;
1810 oi.typename = NULL;
1811 oi.typep = NULL;
1812 return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
1813 }
1814
1815 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1816 {
1817 int ret;
1818 git_zstream stream;
1819 char hdr[8192];
1820
1821 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1822 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1823 return NULL;
1824
1825 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1826 }
1827
1828 unsigned long get_size_from_delta(struct packed_git *p,
1829 struct pack_window **w_curs,
1830 off_t curpos)
1831 {
1832 const unsigned char *data;
1833 unsigned char delta_head[20], *in;
1834 git_zstream stream;
1835 int st;
1836
1837 memset(&stream, 0, sizeof(stream));
1838 stream.next_out = delta_head;
1839 stream.avail_out = sizeof(delta_head);
1840
1841 git_inflate_init(&stream);
1842 do {
1843 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1844 stream.next_in = in;
1845 st = git_inflate(&stream, Z_FINISH);
1846 curpos += stream.next_in - in;
1847 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1848 stream.total_out < sizeof(delta_head));
1849 git_inflate_end(&stream);
1850 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1851 error("delta data unpack-initial failed");
1852 return 0;
1853 }
1854
1855 /* Examine the initial part of the delta to figure out
1856 * the result size.
1857 */
1858 data = delta_head;
1859
1860 /* ignore base size */
1861 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1862
1863 /* Read the result size */
1864 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1865 }
1866
1867 static off_t get_delta_base(struct packed_git *p,
1868 struct pack_window **w_curs,
1869 off_t *curpos,
1870 enum object_type type,
1871 off_t delta_obj_offset)
1872 {
1873 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1874 off_t base_offset;
1875
1876 /* use_pack() assured us we have [base_info, base_info + 20)
1877 * as a range that we can look at without walking off the
1878 * end of the mapped window. Its actually the hash size
1879 * that is assured. An OFS_DELTA longer than the hash size
1880 * is stupid, as then a REF_DELTA would be smaller to store.
1881 */
1882 if (type == OBJ_OFS_DELTA) {
1883 unsigned used = 0;
1884 unsigned char c = base_info[used++];
1885 base_offset = c & 127;
1886 while (c & 128) {
1887 base_offset += 1;
1888 if (!base_offset || MSB(base_offset, 7))
1889 return 0; /* overflow */
1890 c = base_info[used++];
1891 base_offset = (base_offset << 7) + (c & 127);
1892 }
1893 base_offset = delta_obj_offset - base_offset;
1894 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1895 return 0; /* out of bound */
1896 *curpos += used;
1897 } else if (type == OBJ_REF_DELTA) {
1898 /* The base entry _must_ be in the same pack */
1899 base_offset = find_pack_entry_one(base_info, p);
1900 *curpos += 20;
1901 } else
1902 die("I am totally screwed");
1903 return base_offset;
1904 }
1905
1906 /*
1907 * Like get_delta_base above, but we return the sha1 instead of the pack
1908 * offset. This means it is cheaper for REF deltas (we do not have to do
1909 * the final object lookup), but more expensive for OFS deltas (we
1910 * have to load the revidx to convert the offset back into a sha1).
1911 */
1912 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1913 struct pack_window **w_curs,
1914 off_t curpos,
1915 enum object_type type,
1916 off_t delta_obj_offset)
1917 {
1918 if (type == OBJ_REF_DELTA) {
1919 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1920 return base;
1921 } else if (type == OBJ_OFS_DELTA) {
1922 struct revindex_entry *revidx;
1923 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1924 type, delta_obj_offset);
1925
1926 if (!base_offset)
1927 return NULL;
1928
1929 revidx = find_pack_revindex(p, base_offset);
1930 if (!revidx)
1931 return NULL;
1932
1933 return nth_packed_object_sha1(p, revidx->nr);
1934 } else
1935 return NULL;
1936 }
1937
1938 int unpack_object_header(struct packed_git *p,
1939 struct pack_window **w_curs,
1940 off_t *curpos,
1941 unsigned long *sizep)
1942 {
1943 unsigned char *base;
1944 unsigned long left;
1945 unsigned long used;
1946 enum object_type type;
1947
1948 /* use_pack() assures us we have [base, base + 20) available
1949 * as a range that we can look at. (Its actually the hash
1950 * size that is assured.) With our object header encoding
1951 * the maximum deflated object size is 2^137, which is just
1952 * insane, so we know won't exceed what we have been given.
1953 */
1954 base = use_pack(p, w_curs, *curpos, &left);
1955 used = unpack_object_header_buffer(base, left, &type, sizep);
1956 if (!used) {
1957 type = OBJ_BAD;
1958 } else
1959 *curpos += used;
1960
1961 return type;
1962 }
1963
1964 static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1965 {
1966 int type;
1967 struct revindex_entry *revidx;
1968 const unsigned char *sha1;
1969 revidx = find_pack_revindex(p, obj_offset);
1970 if (!revidx)
1971 return OBJ_BAD;
1972 sha1 = nth_packed_object_sha1(p, revidx->nr);
1973 mark_bad_packed_object(p, sha1);
1974 type = sha1_object_info(sha1, NULL);
1975 if (type <= OBJ_NONE)
1976 return OBJ_BAD;
1977 return type;
1978 }
1979
1980 #define POI_STACK_PREALLOC 64
1981
1982 static enum object_type packed_to_object_type(struct packed_git *p,
1983 off_t obj_offset,
1984 enum object_type type,
1985 struct pack_window **w_curs,
1986 off_t curpos)
1987 {
1988 off_t small_poi_stack[POI_STACK_PREALLOC];
1989 off_t *poi_stack = small_poi_stack;
1990 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1991
1992 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1993 off_t base_offset;
1994 unsigned long size;
1995 /* Push the object we're going to leave behind */
1996 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1997 poi_stack_alloc = alloc_nr(poi_stack_nr);
1998 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1999 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
2000 } else {
2001 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
2002 }
2003 poi_stack[poi_stack_nr++] = obj_offset;
2004 /* If parsing the base offset fails, just unwind */
2005 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
2006 if (!base_offset)
2007 goto unwind;
2008 curpos = obj_offset = base_offset;
2009 type = unpack_object_header(p, w_curs, &curpos, &size);
2010 if (type <= OBJ_NONE) {
2011 /* If getting the base itself fails, we first
2012 * retry the base, otherwise unwind */
2013 type = retry_bad_packed_offset(p, base_offset);
2014 if (type > OBJ_NONE)
2015 goto out;
2016 goto unwind;
2017 }
2018 }
2019
2020 switch (type) {
2021 case OBJ_BAD:
2022 case OBJ_COMMIT:
2023 case OBJ_TREE:
2024 case OBJ_BLOB:
2025 case OBJ_TAG:
2026 break;
2027 default:
2028 error("unknown object type %i at offset %"PRIuMAX" in %s",
2029 type, (uintmax_t)obj_offset, p->pack_name);
2030 type = OBJ_BAD;
2031 }
2032
2033 out:
2034 if (poi_stack != small_poi_stack)
2035 free(poi_stack);
2036 return type;
2037
2038 unwind:
2039 while (poi_stack_nr) {
2040 obj_offset = poi_stack[--poi_stack_nr];
2041 type = retry_bad_packed_offset(p, obj_offset);
2042 if (type > OBJ_NONE)
2043 goto out;
2044 }
2045 type = OBJ_BAD;
2046 goto out;
2047 }
2048
2049 static int packed_object_info(struct packed_git *p, off_t obj_offset,
2050 struct object_info *oi)
2051 {
2052 struct pack_window *w_curs = NULL;
2053 unsigned long size;
2054 off_t curpos = obj_offset;
2055 enum object_type type;
2056
2057 /*
2058 * We always get the representation type, but only convert it to
2059 * a "real" type later if the caller is interested.
2060 */
2061 type = unpack_object_header(p, &w_curs, &curpos, &size);
2062
2063 if (oi->sizep) {
2064 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2065 off_t tmp_pos = curpos;
2066 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2067 type, obj_offset);
2068 if (!base_offset) {
2069 type = OBJ_BAD;
2070 goto out;
2071 }
2072 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2073 if (*oi->sizep == 0) {
2074 type = OBJ_BAD;
2075 goto out;
2076 }
2077 } else {
2078 *oi->sizep = size;
2079 }
2080 }
2081
2082 if (oi->disk_sizep) {
2083 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2084 *oi->disk_sizep = revidx[1].offset - obj_offset;
2085 }
2086
2087 if (oi->typep) {
2088 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
2089 if (*oi->typep < 0) {
2090 type = OBJ_BAD;
2091 goto out;
2092 }
2093 }
2094
2095 if (oi->delta_base_sha1) {
2096 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2097 const unsigned char *base;
2098
2099 base = get_delta_base_sha1(p, &w_curs, curpos,
2100 type, obj_offset);
2101 if (!base) {
2102 type = OBJ_BAD;
2103 goto out;
2104 }
2105
2106 hashcpy(oi->delta_base_sha1, base);
2107 } else
2108 hashclr(oi->delta_base_sha1);
2109 }
2110
2111 out:
2112 unuse_pack(&w_curs);
2113 return type;
2114 }
2115
2116 static void *unpack_compressed_entry(struct packed_git *p,
2117 struct pack_window **w_curs,
2118 off_t curpos,
2119 unsigned long size)
2120 {
2121 int st;
2122 git_zstream stream;
2123 unsigned char *buffer, *in;
2124
2125 buffer = xmallocz_gently(size);
2126 if (!buffer)
2127 return NULL;
2128 memset(&stream, 0, sizeof(stream));
2129 stream.next_out = buffer;
2130 stream.avail_out = size + 1;
2131
2132 git_inflate_init(&stream);
2133 do {
2134 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2135 stream.next_in = in;
2136 st = git_inflate(&stream, Z_FINISH);
2137 if (!stream.avail_out)
2138 break; /* the payload is larger than it should be */
2139 curpos += stream.next_in - in;
2140 } while (st == Z_OK || st == Z_BUF_ERROR);
2141 git_inflate_end(&stream);
2142 if ((st != Z_STREAM_END) || stream.total_out != size) {
2143 free(buffer);
2144 return NULL;
2145 }
2146
2147 return buffer;
2148 }
2149
2150 static struct hashmap delta_base_cache;
2151 static size_t delta_base_cached;
2152
2153 static LIST_HEAD(delta_base_cache_lru);
2154
2155 struct delta_base_cache_key {
2156 struct packed_git *p;
2157 off_t base_offset;
2158 };
2159
2160 struct delta_base_cache_entry {
2161 struct hashmap hash;
2162 struct delta_base_cache_key key;
2163 struct list_head lru;
2164 void *data;
2165 unsigned long size;
2166 enum object_type type;
2167 };
2168
2169 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
2170 {
2171 unsigned int hash;
2172
2173 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
2174 hash += (hash >> 8) + (hash >> 16);
2175 return hash;
2176 }
2177
2178 static struct delta_base_cache_entry *
2179 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
2180 {
2181 struct hashmap_entry entry;
2182 struct delta_base_cache_key key;
2183
2184 if (!delta_base_cache.cmpfn)
2185 return NULL;
2186
2187 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
2188 key.p = p;
2189 key.base_offset = base_offset;
2190 return hashmap_get(&delta_base_cache, &entry, &key);
2191 }
2192
2193 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
2194 const struct delta_base_cache_key *b)
2195 {
2196 return a->p == b->p && a->base_offset == b->base_offset;
2197 }
2198
2199 static int delta_base_cache_hash_cmp(const void *va, const void *vb,
2200 const void *vkey)
2201 {
2202 const struct delta_base_cache_entry *a = va, *b = vb;
2203 const struct delta_base_cache_key *key = vkey;
2204 if (key)
2205 return !delta_base_cache_key_eq(&a->key, key);
2206 else
2207 return !delta_base_cache_key_eq(&a->key, &b->key);
2208 }
2209
2210 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2211 {
2212 return !!get_delta_base_cache_entry(p, base_offset);
2213 }
2214
2215 /*
2216 * Remove the entry from the cache, but do _not_ free the associated
2217 * entry data. The caller takes ownership of the "data" buffer, and
2218 * should copy out any fields it wants before detaching.
2219 */
2220 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2221 {
2222 hashmap_remove(&delta_base_cache, ent, &ent->key);
2223 list_del(&ent->lru);
2224 delta_base_cached -= ent->size;
2225 free(ent);
2226 }
2227
2228 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
2229 unsigned long *base_size, enum object_type *type)
2230 {
2231 struct delta_base_cache_entry *ent;
2232
2233 ent = get_delta_base_cache_entry(p, base_offset);
2234 if (!ent)
2235 return unpack_entry(p, base_offset, type, base_size);
2236
2237 *type = ent->type;
2238 *base_size = ent->size;
2239 return xmemdupz(ent->data, ent->size);
2240 }
2241
2242 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2243 {
2244 free(ent->data);
2245 detach_delta_base_cache_entry(ent);
2246 }
2247
2248 void clear_delta_base_cache(void)
2249 {
2250 struct hashmap_iter iter;
2251 struct delta_base_cache_entry *entry;
2252 for (entry = hashmap_iter_first(&delta_base_cache, &iter);
2253 entry;
2254 entry = hashmap_iter_next(&iter)) {
2255 release_delta_base_cache(entry);
2256 }
2257 }
2258
2259 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2260 void *base, unsigned long base_size, enum object_type type)
2261 {
2262 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
2263 struct list_head *lru, *tmp;
2264
2265 delta_base_cached += base_size;
2266
2267 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2268 struct delta_base_cache_entry *f =
2269 list_entry(lru, struct delta_base_cache_entry, lru);
2270 if (delta_base_cached <= delta_base_cache_limit)
2271 break;
2272 release_delta_base_cache(f);
2273 }
2274
2275 ent->key.p = p;
2276 ent->key.base_offset = base_offset;
2277 ent->type = type;
2278 ent->data = base;
2279 ent->size = base_size;
2280 list_add_tail(&ent->lru, &delta_base_cache_lru);
2281
2282 if (!delta_base_cache.cmpfn)
2283 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, 0);
2284 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
2285 hashmap_add(&delta_base_cache, ent);
2286 }
2287
2288 static void *read_object(const unsigned char *sha1, enum object_type *type,
2289 unsigned long *size);
2290
2291 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2292 {
2293 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2294 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2295 p->pack_name, (uintmax_t)obj_offset);
2296 }
2297
2298 int do_check_packed_object_crc;
2299
2300 #define UNPACK_ENTRY_STACK_PREALLOC 64
2301 struct unpack_entry_stack_ent {
2302 off_t obj_offset;
2303 off_t curpos;
2304 unsigned long size;
2305 };
2306
2307 void *unpack_entry(struct packed_git *p, off_t obj_offset,
2308 enum object_type *final_type, unsigned long *final_size)
2309 {
2310 struct pack_window *w_curs = NULL;
2311 off_t curpos = obj_offset;
2312 void *data = NULL;
2313 unsigned long size;
2314 enum object_type type;
2315 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2316 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2317 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2318 int base_from_cache = 0;
2319
2320 write_pack_access_log(p, obj_offset);
2321
2322 /* PHASE 1: drill down to the innermost base object */
2323 for (;;) {
2324 off_t base_offset;
2325 int i;
2326 struct delta_base_cache_entry *ent;
2327
2328 ent = get_delta_base_cache_entry(p, curpos);
2329 if (ent) {
2330 type = ent->type;
2331 data = ent->data;
2332 size = ent->size;
2333 detach_delta_base_cache_entry(ent);
2334 base_from_cache = 1;
2335 break;
2336 }
2337
2338 if (do_check_packed_object_crc && p->index_version > 1) {
2339 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2340 off_t len = revidx[1].offset - obj_offset;
2341 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2342 const unsigned char *sha1 =
2343 nth_packed_object_sha1(p, revidx->nr);
2344 error("bad packed object CRC for %s",
2345 sha1_to_hex(sha1));
2346 mark_bad_packed_object(p, sha1);
2347 unuse_pack(&w_curs);
2348 return NULL;
2349 }
2350 }
2351
2352 type = unpack_object_header(p, &w_curs, &curpos, &size);
2353 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2354 break;
2355
2356 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2357 if (!base_offset) {
2358 error("failed to validate delta base reference "
2359 "at offset %"PRIuMAX" from %s",
2360 (uintmax_t)curpos, p->pack_name);
2361 /* bail to phase 2, in hopes of recovery */
2362 data = NULL;
2363 break;
2364 }
2365
2366 /* push object, proceed to base */
2367 if (delta_stack_nr >= delta_stack_alloc
2368 && delta_stack == small_delta_stack) {
2369 delta_stack_alloc = alloc_nr(delta_stack_nr);
2370 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
2371 memcpy(delta_stack, small_delta_stack,
2372 sizeof(*delta_stack)*delta_stack_nr);
2373 } else {
2374 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2375 }
2376 i = delta_stack_nr++;
2377 delta_stack[i].obj_offset = obj_offset;
2378 delta_stack[i].curpos = curpos;
2379 delta_stack[i].size = size;
2380
2381 curpos = obj_offset = base_offset;
2382 }
2383
2384 /* PHASE 2: handle the base */
2385 switch (type) {
2386 case OBJ_OFS_DELTA:
2387 case OBJ_REF_DELTA:
2388 if (data)
2389 die("BUG: unpack_entry: left loop at a valid delta");
2390 break;
2391 case OBJ_COMMIT:
2392 case OBJ_TREE:
2393 case OBJ_BLOB:
2394 case OBJ_TAG:
2395 if (!base_from_cache)
2396 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2397 break;
2398 default:
2399 data = NULL;
2400 error("unknown object type %i at offset %"PRIuMAX" in %s",
2401 type, (uintmax_t)obj_offset, p->pack_name);
2402 }
2403
2404 /* PHASE 3: apply deltas in order */
2405
2406 /* invariants:
2407 * 'data' holds the base data, or NULL if there was corruption
2408 */
2409 while (delta_stack_nr) {
2410 void *delta_data;
2411 void *base = data;
2412 unsigned long delta_size, base_size = size;
2413 int i;
2414
2415 data = NULL;
2416
2417 if (base)
2418 add_delta_base_cache(p, obj_offset, base, base_size, type);
2419
2420 if (!base) {
2421 /*
2422 * We're probably in deep shit, but let's try to fetch
2423 * the required base anyway from another pack or loose.
2424 * This is costly but should happen only in the presence
2425 * of a corrupted pack, and is better than failing outright.
2426 */
2427 struct revindex_entry *revidx;
2428 const unsigned char *base_sha1;
2429 revidx = find_pack_revindex(p, obj_offset);
2430 if (revidx) {
2431 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2432 error("failed to read delta base object %s"
2433 " at offset %"PRIuMAX" from %s",
2434 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2435 p->pack_name);
2436 mark_bad_packed_object(p, base_sha1);
2437 base = read_object(base_sha1, &type, &base_size);
2438 }
2439 }
2440
2441 i = --delta_stack_nr;
2442 obj_offset = delta_stack[i].obj_offset;
2443 curpos = delta_stack[i].curpos;
2444 delta_size = delta_stack[i].size;
2445
2446 if (!base)
2447 continue;
2448
2449 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2450
2451 if (!delta_data) {
2452 error("failed to unpack compressed delta "
2453 "at offset %"PRIuMAX" from %s",
2454 (uintmax_t)curpos, p->pack_name);
2455 data = NULL;
2456 continue;
2457 }
2458
2459 data = patch_delta(base, base_size,
2460 delta_data, delta_size,
2461 &size);
2462
2463 /*
2464 * We could not apply the delta; warn the user, but keep going.
2465 * Our failure will be noticed either in the next iteration of
2466 * the loop, or if this is the final delta, in the caller when
2467 * we return NULL. Those code paths will take care of making
2468 * a more explicit warning and retrying with another copy of
2469 * the object.
2470 */
2471 if (!data)
2472 error("failed to apply delta");
2473
2474 free(delta_data);
2475 }
2476
2477 *final_type = type;
2478 *final_size = size;
2479
2480 unuse_pack(&w_curs);
2481
2482 if (delta_stack != small_delta_stack)
2483 free(delta_stack);
2484
2485 return data;
2486 }
2487
2488 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2489 uint32_t n)
2490 {
2491 const unsigned char *index = p->index_data;
2492 if (!index) {
2493 if (open_pack_index(p))
2494 return NULL;
2495 index = p->index_data;
2496 }
2497 if (n >= p->num_objects)
2498 return NULL;
2499 index += 4 * 256;
2500 if (p->index_version == 1) {
2501 return index + 24 * n + 4;
2502 } else {
2503 index += 8;
2504 return index + 20 * n;
2505 }
2506 }
2507
2508 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2509 {
2510 const unsigned char *ptr = vptr;
2511 const unsigned char *start = p->index_data;
2512 const unsigned char *end = start + p->index_size;
2513 if (ptr < start)
2514 die(_("offset before start of pack index for %s (corrupt index?)"),
2515 p->pack_name);
2516 /* No need to check for underflow; .idx files must be at least 8 bytes */
2517 if (ptr >= end - 8)
2518 die(_("offset beyond end of pack index for %s (truncated index?)"),
2519 p->pack_name);
2520 }
2521
2522 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2523 {
2524 const unsigned char *index = p->index_data;
2525 index += 4 * 256;
2526 if (p->index_version == 1) {
2527 return ntohl(*((uint32_t *)(index + 24 * n)));
2528 } else {
2529 uint32_t off;
2530 index += 8 + p->num_objects * (20 + 4);
2531 off = ntohl(*((uint32_t *)(index + 4 * n)));
2532 if (!(off & 0x80000000))
2533 return off;
2534 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2535 check_pack_index_ptr(p, index);
2536 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2537 ntohl(*((uint32_t *)(index + 4)));
2538 }
2539 }
2540
2541 off_t find_pack_entry_one(const unsigned char *sha1,
2542 struct packed_git *p)
2543 {
2544 const uint32_t *level1_ofs = p->index_data;
2545 const unsigned char *index = p->index_data;
2546 unsigned hi, lo, stride;
2547 static int use_lookup = -1;
2548 static int debug_lookup = -1;
2549
2550 if (debug_lookup < 0)
2551 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2552
2553 if (!index) {
2554 if (open_pack_index(p))
2555 return 0;
2556 level1_ofs = p->index_data;
2557 index = p->index_data;
2558 }
2559 if (p->index_version > 1) {
2560 level1_ofs += 2;
2561 index += 8;
2562 }
2563 index += 4 * 256;
2564 hi = ntohl(level1_ofs[*sha1]);
2565 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2566 if (p->index_version > 1) {
2567 stride = 20;
2568 } else {
2569 stride = 24;
2570 index += 4;
2571 }
2572
2573 if (debug_lookup)
2574 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2575 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2576
2577 if (use_lookup < 0)
2578 use_lookup = !!getenv("GIT_USE_LOOKUP");
2579 if (use_lookup) {
2580 int pos = sha1_entry_pos(index, stride, 0,
2581 lo, hi, p->num_objects, sha1);
2582 if (pos < 0)
2583 return 0;
2584 return nth_packed_object_offset(p, pos);
2585 }
2586
2587 do {
2588 unsigned mi = (lo + hi) / 2;
2589 int cmp = hashcmp(index + mi * stride, sha1);
2590
2591 if (debug_lookup)
2592 printf("lo %u hi %u rg %u mi %u\n",
2593 lo, hi, hi - lo, mi);
2594 if (!cmp)
2595 return nth_packed_object_offset(p, mi);
2596 if (cmp > 0)
2597 hi = mi;
2598 else
2599 lo = mi+1;
2600 } while (lo < hi);
2601 return 0;
2602 }
2603
2604 int is_pack_valid(struct packed_git *p)
2605 {
2606 /* An already open pack is known to be valid. */
2607 if (p->pack_fd != -1)
2608 return 1;
2609
2610 /* If the pack has one window completely covering the
2611 * file size, the pack is known to be valid even if
2612 * the descriptor is not currently open.
2613 */
2614 if (p->windows) {
2615 struct pack_window *w = p->windows;
2616
2617 if (!w->offset && w->len == p->pack_size)
2618 return 1;
2619 }
2620
2621 /* Force the pack to open to prove its valid. */
2622 return !open_packed_git(p);
2623 }
2624
2625 static int fill_pack_entry(const unsigned char *sha1,
2626 struct pack_entry *e,
2627 struct packed_git *p)
2628 {
2629 off_t offset;
2630
2631 if (p->num_bad_objects) {
2632 unsigned i;
2633 for (i = 0; i < p->num_bad_objects; i++)
2634 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2635 return 0;
2636 }
2637
2638 offset = find_pack_entry_one(sha1, p);
2639 if (!offset)
2640 return 0;
2641
2642 /*
2643 * We are about to tell the caller where they can locate the
2644 * requested object. We better make sure the packfile is
2645 * still here and can be accessed before supplying that
2646 * answer, as it may have been deleted since the index was
2647 * loaded!
2648 */
2649 if (!is_pack_valid(p))
2650 return 0;
2651 e->offset = offset;
2652 e->p = p;
2653 hashcpy(e->sha1, sha1);
2654 return 1;
2655 }
2656
2657 /*
2658 * Iff a pack file contains the object named by sha1, return true and
2659 * store its location to e.
2660 */
2661 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2662 {
2663 struct mru_entry *p;
2664
2665 prepare_packed_git();
2666 if (!packed_git)
2667 return 0;
2668
2669 for (p = packed_git_mru->head; p; p = p->next) {
2670 if (fill_pack_entry(sha1, e, p->item)) {
2671 mru_mark(packed_git_mru, p);
2672 return 1;
2673 }
2674 }
2675 return 0;
2676 }
2677
2678 struct packed_git *find_sha1_pack(const unsigned char *sha1,
2679 struct packed_git *packs)
2680 {
2681 struct packed_git *p;
2682
2683 for (p = packs; p; p = p->next) {
2684 if (find_pack_entry_one(sha1, p))
2685 return p;
2686 }
2687 return NULL;
2688
2689 }
2690
2691 static int sha1_loose_object_info(const unsigned char *sha1,
2692 struct object_info *oi,
2693 int flags)
2694 {
2695 int status = 0;
2696 unsigned long mapsize;
2697 void *map;
2698 git_zstream stream;
2699 char hdr[32];
2700 struct strbuf hdrbuf = STRBUF_INIT;
2701
2702 if (oi->delta_base_sha1)
2703 hashclr(oi->delta_base_sha1);
2704
2705 /*
2706 * If we don't care about type or size, then we don't
2707 * need to look inside the object at all. Note that we
2708 * do not optimize out the stat call, even if the
2709 * caller doesn't care about the disk-size, since our
2710 * return value implicitly indicates whether the
2711 * object even exists.
2712 */
2713 if (!oi->typep && !oi->typename && !oi->sizep) {
2714 struct stat st;
2715 if (stat_sha1_file(sha1, &st) < 0)
2716 return -1;
2717 if (oi->disk_sizep)
2718 *oi->disk_sizep = st.st_size;
2719 return 0;
2720 }
2721
2722 map = map_sha1_file(sha1, &mapsize);
2723 if (!map)
2724 return -1;
2725 if (oi->disk_sizep)
2726 *oi->disk_sizep = mapsize;
2727 if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
2728 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2729 status = error("unable to unpack %s header with --allow-unknown-type",
2730 sha1_to_hex(sha1));
2731 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2732 status = error("unable to unpack %s header",
2733 sha1_to_hex(sha1));
2734 if (status < 0)
2735 ; /* Do nothing */
2736 else if (hdrbuf.len) {
2737 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2738 status = error("unable to parse %s header with --allow-unknown-type",
2739 sha1_to_hex(sha1));
2740 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
2741 status = error("unable to parse %s header", sha1_to_hex(sha1));
2742 git_inflate_end(&stream);
2743 munmap(map, mapsize);
2744 if (status && oi->typep)
2745 *oi->typep = status;
2746 strbuf_release(&hdrbuf);
2747 return 0;
2748 }
2749
2750 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
2751 {
2752 struct cached_object *co;
2753 struct pack_entry e;
2754 int rtype;
2755 enum object_type real_type;
2756 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
2757
2758 co = find_cached_object(real);
2759 if (co) {
2760 if (oi->typep)
2761 *(oi->typep) = co->type;
2762 if (oi->sizep)
2763 *(oi->sizep) = co->size;
2764 if (oi->disk_sizep)
2765 *(oi->disk_sizep) = 0;
2766 if (oi->delta_base_sha1)
2767 hashclr(oi->delta_base_sha1);
2768 if (oi->typename)
2769 strbuf_addstr(oi->typename, typename(co->type));
2770 oi->whence = OI_CACHED;
2771 return 0;
2772 }
2773
2774 if (!find_pack_entry(real, &e)) {
2775 /* Most likely it's a loose object. */
2776 if (!sha1_loose_object_info(real, oi, flags)) {
2777 oi->whence = OI_LOOSE;
2778 return 0;
2779 }
2780
2781 /* Not a loose object; someone else may have just packed it. */
2782 reprepare_packed_git();
2783 if (!find_pack_entry(real, &e))
2784 return -1;
2785 }
2786
2787 /*
2788 * packed_object_info() does not follow the delta chain to
2789 * find out the real type, unless it is given oi->typep.
2790 */
2791 if (oi->typename && !oi->typep)
2792 oi->typep = &real_type;
2793
2794 rtype = packed_object_info(e.p, e.offset, oi);
2795 if (rtype < 0) {
2796 mark_bad_packed_object(e.p, real);
2797 if (oi->typep == &real_type)
2798 oi->typep = NULL;
2799 return sha1_object_info_extended(real, oi, 0);
2800 } else if (in_delta_base_cache(e.p, e.offset)) {
2801 oi->whence = OI_DBCACHED;
2802 } else {
2803 oi->whence = OI_PACKED;
2804 oi->u.packed.offset = e.offset;
2805 oi->u.packed.pack = e.p;
2806 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2807 rtype == OBJ_OFS_DELTA);
2808 }
2809 if (oi->typename)
2810 strbuf_addstr(oi->typename, typename(*oi->typep));
2811 if (oi->typep == &real_type)
2812 oi->typep = NULL;
2813
2814 return 0;
2815 }
2816
2817 /* returns enum object_type or negative */
2818 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2819 {
2820 enum object_type type;
2821 struct object_info oi = {NULL};
2822
2823 oi.typep = &type;
2824 oi.sizep = sizep;
2825 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
2826 return -1;
2827 return type;
2828 }
2829
2830 static void *read_packed_sha1(const unsigned char *sha1,
2831 enum object_type *type, unsigned long *size)
2832 {
2833 struct pack_entry e;
2834 void *data;
2835
2836 if (!find_pack_entry(sha1, &e))
2837 return NULL;
2838 data = cache_or_unpack_entry(e.p, e.offset, size, type);
2839 if (!data) {
2840 /*
2841 * We're probably in deep shit, but let's try to fetch
2842 * the required object anyway from another pack or loose.
2843 * This should happen only in the presence of a corrupted
2844 * pack, and is better than failing outright.
2845 */
2846 error("failed to read object %s at offset %"PRIuMAX" from %s",
2847 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2848 mark_bad_packed_object(e.p, sha1);
2849 data = read_object(sha1, type, size);
2850 }
2851 return data;
2852 }
2853
2854 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2855 unsigned char *sha1)
2856 {
2857 struct cached_object *co;
2858
2859 hash_sha1_file(buf, len, typename(type), sha1);
2860 if (has_sha1_file(sha1) || find_cached_object(sha1))
2861 return 0;
2862 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
2863 co = &cached_objects[cached_object_nr++];
2864 co->size = len;
2865 co->type = type;
2866 co->buf = xmalloc(len);
2867 memcpy(co->buf, buf, len);
2868 hashcpy(co->sha1, sha1);
2869 return 0;
2870 }
2871
2872 static void *read_object(const unsigned char *sha1, enum object_type *type,
2873 unsigned long *size)
2874 {
2875 unsigned long mapsize;
2876 void *map, *buf;
2877 struct cached_object *co;
2878
2879 co = find_cached_object(sha1);
2880 if (co) {
2881 *type = co->type;
2882 *size = co->size;
2883 return xmemdupz(co->buf, co->size);
2884 }
2885
2886 buf = read_packed_sha1(sha1, type, size);
2887 if (buf)
2888 return buf;
2889 map = map_sha1_file(sha1, &mapsize);
2890 if (map) {
2891 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2892 munmap(map, mapsize);
2893 return buf;
2894 }
2895 reprepare_packed_git();
2896 return read_packed_sha1(sha1, type, size);
2897 }
2898
2899 /*
2900 * This function dies on corrupt objects; the callers who want to
2901 * deal with them should arrange to call read_object() and give error
2902 * messages themselves.
2903 */
2904 void *read_sha1_file_extended(const unsigned char *sha1,
2905 enum object_type *type,
2906 unsigned long *size,
2907 unsigned flag)
2908 {
2909 void *data;
2910 const struct packed_git *p;
2911 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
2912
2913 errno = 0;
2914 data = read_object(repl, type, size);
2915 if (data)
2916 return data;
2917
2918 if (errno && errno != ENOENT)
2919 die_errno("failed to read object %s", sha1_to_hex(sha1));
2920
2921 /* die if we replaced an object with one that does not exist */
2922 if (repl != sha1)
2923 die("replacement %s not found for %s",
2924 sha1_to_hex(repl), sha1_to_hex(sha1));
2925
2926 if (has_loose_object(repl)) {
2927 const char *path = sha1_file_name(sha1);
2928
2929 die("loose object %s (stored in %s) is corrupt",
2930 sha1_to_hex(repl), path);
2931 }
2932
2933 if ((p = has_packed_and_bad(repl)) != NULL)
2934 die("packed object %s (stored in %s) is corrupt",
2935 sha1_to_hex(repl), p->pack_name);
2936
2937 return NULL;
2938 }
2939
2940 void *read_object_with_reference(const unsigned char *sha1,
2941 const char *required_type_name,
2942 unsigned long *size,
2943 unsigned char *actual_sha1_return)
2944 {
2945 enum object_type type, required_type;
2946 void *buffer;
2947 unsigned long isize;
2948 unsigned char actual_sha1[20];
2949
2950 required_type = type_from_string(required_type_name);
2951 hashcpy(actual_sha1, sha1);
2952 while (1) {
2953 int ref_length = -1;
2954 const char *ref_type = NULL;
2955
2956 buffer = read_sha1_file(actual_sha1, &type, &isize);
2957 if (!buffer)
2958 return NULL;
2959 if (type == required_type) {
2960 *size = isize;
2961 if (actual_sha1_return)
2962 hashcpy(actual_sha1_return, actual_sha1);
2963 return buffer;
2964 }
2965 /* Handle references */
2966 else if (type == OBJ_COMMIT)
2967 ref_type = "tree ";
2968 else if (type == OBJ_TAG)
2969 ref_type = "object ";
2970 else {
2971 free(buffer);
2972 return NULL;
2973 }
2974 ref_length = strlen(ref_type);
2975
2976 if (ref_length + 40 > isize ||
2977 memcmp(buffer, ref_type, ref_length) ||
2978 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2979 free(buffer);
2980 return NULL;
2981 }
2982 free(buffer);
2983 /* Now we have the ID of the referred-to object in
2984 * actual_sha1. Check again. */
2985 }
2986 }
2987
2988 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2989 const char *type, unsigned char *sha1,
2990 char *hdr, int *hdrlen)
2991 {
2992 git_SHA_CTX c;
2993
2994 /* Generate the header */
2995 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
2996
2997 /* Sha1.. */
2998 git_SHA1_Init(&c);
2999 git_SHA1_Update(&c, hdr, *hdrlen);
3000 git_SHA1_Update(&c, buf, len);
3001 git_SHA1_Final(sha1, &c);
3002 }
3003
3004 /*
3005 * Move the just written object into its final resting place.
3006 */
3007 int finalize_object_file(const char *tmpfile, const char *filename)
3008 {
3009 int ret = 0;
3010
3011 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
3012 goto try_rename;
3013 else if (link(tmpfile, filename))
3014 ret = errno;
3015
3016 /*
3017 * Coda hack - coda doesn't like cross-directory links,
3018 * so we fall back to a rename, which will mean that it
3019 * won't be able to check collisions, but that's not a
3020 * big deal.
3021 *
3022 * The same holds for FAT formatted media.
3023 *
3024 * When this succeeds, we just return. We have nothing
3025 * left to unlink.
3026 */
3027 if (ret && ret != EEXIST) {
3028 try_rename:
3029 if (!rename(tmpfile, filename))
3030 goto out;
3031 ret = errno;
3032 }
3033 unlink_or_warn(tmpfile);
3034 if (ret) {
3035 if (ret != EEXIST) {
3036 return error_errno("unable to write sha1 filename %s", filename);
3037 }
3038 /* FIXME!!! Collision check here ? */
3039 }
3040
3041 out:
3042 if (adjust_shared_perm(filename))
3043 return error("unable to set permission to '%s'", filename);
3044 return 0;
3045 }
3046
3047 static int write_buffer(int fd, const void *buf, size_t len)
3048 {
3049 if (write_in_full(fd, buf, len) < 0)
3050 return error_errno("file write error");
3051 return 0;
3052 }
3053
3054 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
3055 unsigned char *sha1)
3056 {
3057 char hdr[32];
3058 int hdrlen = sizeof(hdr);
3059 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3060 return 0;
3061 }
3062
3063 /* Finalize a file on disk, and close it. */
3064 static void close_sha1_file(int fd)
3065 {
3066 if (fsync_object_files)
3067 fsync_or_die(fd, "sha1 file");
3068 if (close(fd) != 0)
3069 die_errno("error when closing sha1 file");
3070 }
3071
3072 /* Size of directory component, including the ending '/' */
3073 static inline int directory_size(const char *filename)
3074 {
3075 const char *s = strrchr(filename, '/');
3076 if (!s)
3077 return 0;
3078 return s - filename + 1;
3079 }
3080
3081 /*
3082 * This creates a temporary file in the same directory as the final
3083 * 'filename'
3084 *
3085 * We want to avoid cross-directory filename renames, because those
3086 * can have problems on various filesystems (FAT, NFS, Coda).
3087 */
3088 static int create_tmpfile(struct strbuf *tmp, const char *filename)
3089 {
3090 int fd, dirlen = directory_size(filename);
3091
3092 strbuf_reset(tmp);
3093 strbuf_add(tmp, filename, dirlen);
3094 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3095 fd = git_mkstemp_mode(tmp->buf, 0444);
3096 if (fd < 0 && dirlen && errno == ENOENT) {
3097 /*
3098 * Make sure the directory exists; note that the contents
3099 * of the buffer are undefined after mkstemp returns an
3100 * error, so we have to rewrite the whole buffer from
3101 * scratch.
3102 */
3103 strbuf_reset(tmp);
3104 strbuf_add(tmp, filename, dirlen - 1);
3105 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
3106 return -1;
3107 if (adjust_shared_perm(tmp->buf))
3108 return -1;
3109
3110 /* Try again */
3111 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3112 fd = git_mkstemp_mode(tmp->buf, 0444);
3113 }
3114 return fd;
3115 }
3116
3117 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
3118 const void *buf, unsigned long len, time_t mtime)
3119 {
3120 int fd, ret;
3121 unsigned char compressed[4096];
3122 git_zstream stream;
3123 git_SHA_CTX c;
3124 unsigned char parano_sha1[20];
3125 static struct strbuf tmp_file = STRBUF_INIT;
3126 const char *filename = sha1_file_name(sha1);
3127
3128 fd = create_tmpfile(&tmp_file, filename);
3129 if (fd < 0) {
3130 if (errno == EACCES)
3131 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
3132 else
3133 return error_errno("unable to create temporary file");
3134 }
3135
3136 /* Set it up */
3137 git_deflate_init(&stream, zlib_compression_level);
3138 stream.next_out = compressed;
3139 stream.avail_out = sizeof(compressed);
3140 git_SHA1_Init(&c);
3141
3142 /* First header.. */
3143 stream.next_in = (unsigned char *)hdr;
3144 stream.avail_in = hdrlen;
3145 while (git_deflate(&stream, 0) == Z_OK)
3146 ; /* nothing */
3147 git_SHA1_Update(&c, hdr, hdrlen);
3148
3149 /* Then the data itself.. */
3150 stream.next_in = (void *)buf;
3151 stream.avail_in = len;
3152 do {
3153 unsigned char *in0 = stream.next_in;
3154 ret = git_deflate(&stream, Z_FINISH);
3155 git_SHA1_Update(&c, in0, stream.next_in - in0);
3156 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3157 die("unable to write sha1 file");
3158 stream.next_out = compressed;
3159 stream.avail_out = sizeof(compressed);
3160 } while (ret == Z_OK);
3161
3162 if (ret != Z_STREAM_END)
3163 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
3164 ret = git_deflate_end_gently(&stream);
3165 if (ret != Z_OK)
3166 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
3167 git_SHA1_Final(parano_sha1, &c);
3168 if (hashcmp(sha1, parano_sha1) != 0)
3169 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
3170
3171 close_sha1_file(fd);
3172
3173 if (mtime) {
3174 struct utimbuf utb;
3175 utb.actime = mtime;
3176 utb.modtime = mtime;
3177 if (utime(tmp_file.buf, &utb) < 0)
3178 warning_errno("failed utime() on %s", tmp_file.buf);
3179 }
3180
3181 return finalize_object_file(tmp_file.buf, filename);
3182 }
3183
3184 static int freshen_loose_object(const unsigned char *sha1)
3185 {
3186 return check_and_freshen(sha1, 1);
3187 }
3188
3189 static int freshen_packed_object(const unsigned char *sha1)
3190 {
3191 struct pack_entry e;
3192 if (!find_pack_entry(sha1, &e))
3193 return 0;
3194 if (e.p->freshened)
3195 return 1;
3196 if (!freshen_file(e.p->pack_name))
3197 return 0;
3198 e.p->freshened = 1;
3199 return 1;
3200 }
3201
3202 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
3203 {
3204 char hdr[32];
3205 int hdrlen = sizeof(hdr);
3206
3207 /* Normally if we have it in the pack then we do not bother writing
3208 * it out into .git/objects/??/?{38} file.
3209 */
3210 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3211 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3212 return 0;
3213 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3214 }
3215
3216 int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3217 unsigned char *sha1, unsigned flags)
3218 {
3219 char *header;
3220 int hdrlen, status = 0;
3221
3222 /* type string, SP, %lu of the length plus NUL must fit this */
3223 hdrlen = strlen(type) + 32;
3224 header = xmalloc(hdrlen);
3225 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3226
3227 if (!(flags & HASH_WRITE_OBJECT))
3228 goto cleanup;
3229 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
3230 goto cleanup;
3231 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3232
3233 cleanup:
3234 free(header);
3235 return status;
3236 }
3237
3238 int force_object_loose(const unsigned char *sha1, time_t mtime)
3239 {
3240 void *buf;
3241 unsigned long len;
3242 enum object_type type;
3243 char hdr[32];
3244 int hdrlen;
3245 int ret;
3246
3247 if (has_loose_object(sha1))
3248 return 0;
3249 buf = read_packed_sha1(sha1, &type, &len);
3250 if (!buf)
3251 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
3252 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
3253 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3254 free(buf);
3255
3256 return ret;
3257 }
3258
3259 int has_pack_index(const unsigned char *sha1)
3260 {
3261 struct stat st;
3262 if (stat(sha1_pack_index_name(sha1), &st))
3263 return 0;
3264 return 1;
3265 }
3266
3267 int has_sha1_pack(const unsigned char *sha1)
3268 {
3269 struct pack_entry e;
3270 return find_pack_entry(sha1, &e);
3271 }
3272
3273 int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
3274 {
3275 struct pack_entry e;
3276
3277 if (find_pack_entry(sha1, &e))
3278 return 1;
3279 if (has_loose_object(sha1))
3280 return 1;
3281 if (flags & HAS_SHA1_QUICK)
3282 return 0;
3283 reprepare_packed_git();
3284 return find_pack_entry(sha1, &e);
3285 }
3286
3287 int has_object_file(const struct object_id *oid)
3288 {
3289 return has_sha1_file(oid->hash);
3290 }
3291
3292 static void check_tree(const void *buf, size_t size)
3293 {
3294 struct tree_desc desc;
3295 struct name_entry entry;
3296
3297 init_tree_desc(&desc, buf, size);
3298 while (tree_entry(&desc, &entry))
3299 /* do nothing
3300 * tree_entry() will die() on malformed entries */
3301 ;
3302 }
3303
3304 static void check_commit(const void *buf, size_t size)
3305 {
3306 struct commit c;
3307 memset(&c, 0, sizeof(c));
3308 if (parse_commit_buffer(&c, buf, size))
3309 die("corrupt commit");
3310 }
3311
3312 static void check_tag(const void *buf, size_t size)
3313 {
3314 struct tag t;
3315 memset(&t, 0, sizeof(t));
3316 if (parse_tag_buffer(&t, buf, size))
3317 die("corrupt tag");
3318 }
3319
3320 static int index_mem(unsigned char *sha1, void *buf, size_t size,
3321 enum object_type type,
3322 const char *path, unsigned flags)
3323 {
3324 int ret, re_allocated = 0;
3325 int write_object = flags & HASH_WRITE_OBJECT;
3326
3327 if (!type)
3328 type = OBJ_BLOB;
3329
3330 /*
3331 * Convert blobs to git internal format
3332 */
3333 if ((type == OBJ_BLOB) && path) {
3334 struct strbuf nbuf = STRBUF_INIT;
3335 if (convert_to_git(path, buf, size, &nbuf,
3336 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
3337 buf = strbuf_detach(&nbuf, &size);
3338 re_allocated = 1;
3339 }
3340 }
3341 if (flags & HASH_FORMAT_CHECK) {
3342 if (type == OBJ_TREE)
3343 check_tree(buf, size);
3344 if (type == OBJ_COMMIT)
3345 check_commit(buf, size);
3346 if (type == OBJ_TAG)
3347 check_tag(buf, size);
3348 }
3349
3350 if (write_object)
3351 ret = write_sha1_file(buf, size, typename(type), sha1);
3352 else
3353 ret = hash_sha1_file(buf, size, typename(type), sha1);
3354 if (re_allocated)
3355 free(buf);
3356 return ret;
3357 }
3358
3359 static int index_stream_convert_blob(unsigned char *sha1, int fd,
3360 const char *path, unsigned flags)
3361 {
3362 int ret;
3363 const int write_object = flags & HASH_WRITE_OBJECT;
3364 struct strbuf sbuf = STRBUF_INIT;
3365
3366 assert(path);
3367 assert(would_convert_to_git_filter_fd(path));
3368
3369 convert_to_git_filter_fd(path, fd, &sbuf,
3370 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3371
3372 if (write_object)
3373 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3374 sha1);
3375 else
3376 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3377 sha1);
3378 strbuf_release(&sbuf);
3379 return ret;
3380 }
3381
3382 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3383 const char *path, unsigned flags)
3384 {
3385 struct strbuf sbuf = STRBUF_INIT;
3386 int ret;
3387
3388 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3389 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3390 else
3391 ret = -1;
3392 strbuf_release(&sbuf);
3393 return ret;
3394 }
3395
3396 #define SMALL_FILE_SIZE (32*1024)
3397
3398 static int index_core(unsigned char *sha1, int fd, size_t size,
3399 enum object_type type, const char *path,
3400 unsigned flags)
3401 {
3402 int ret;
3403
3404 if (!size) {
3405 ret = index_mem(sha1, "", size, type, path, flags);
3406 } else if (size <= SMALL_FILE_SIZE) {
3407 char *buf = xmalloc(size);
3408 if (size == read_in_full(fd, buf, size))
3409 ret = index_mem(sha1, buf, size, type, path, flags);
3410 else
3411 ret = error_errno("short read");
3412 free(buf);
3413 } else {
3414 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3415 ret = index_mem(sha1, buf, size, type, path, flags);
3416 munmap(buf, size);
3417 }
3418 return ret;
3419 }
3420
3421 /*
3422 * This creates one packfile per large blob unless bulk-checkin
3423 * machinery is "plugged".
3424 *
3425 * This also bypasses the usual "convert-to-git" dance, and that is on
3426 * purpose. We could write a streaming version of the converting
3427 * functions and insert that before feeding the data to fast-import
3428 * (or equivalent in-core API described above). However, that is
3429 * somewhat complicated, as we do not know the size of the filter
3430 * result, which we need to know beforehand when writing a git object.
3431 * Since the primary motivation for trying to stream from the working
3432 * tree file and to avoid mmaping it in core is to deal with large
3433 * binary blobs, they generally do not want to get any conversion, and
3434 * callers should avoid this code path when filters are requested.
3435 */
3436 static int index_stream(unsigned char *sha1, int fd, size_t size,
3437 enum object_type type, const char *path,
3438 unsigned flags)
3439 {
3440 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3441 }
3442
3443 int index_fd(unsigned char *sha1, int fd, struct stat *st,
3444 enum object_type type, const char *path, unsigned flags)
3445 {
3446 int ret;
3447
3448 /*
3449 * Call xsize_t() only when needed to avoid potentially unnecessary
3450 * die() for large files.
3451 */
3452 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3453 ret = index_stream_convert_blob(sha1, fd, path, flags);
3454 else if (!S_ISREG(st->st_mode))
3455 ret = index_pipe(sha1, fd, type, path, flags);
3456 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
3457 (path && would_convert_to_git(path)))
3458 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3459 flags);
3460 else
3461 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3462 flags);
3463 close(fd);
3464 return ret;
3465 }
3466
3467 int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3468 {
3469 int fd;
3470 struct strbuf sb = STRBUF_INIT;
3471
3472 switch (st->st_mode & S_IFMT) {
3473 case S_IFREG:
3474 fd = open(path, O_RDONLY);
3475 if (fd < 0)
3476 return error_errno("open(\"%s\")", path);
3477 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3478 return error("%s: failed to insert into database",
3479 path);
3480 break;
3481 case S_IFLNK:
3482 if (strbuf_readlink(&sb, path, st->st_size))
3483 return error_errno("readlink(\"%s\")", path);
3484 if (!(flags & HASH_WRITE_OBJECT))
3485 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3486 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3487 return error("%s: failed to insert into database",
3488 path);
3489 strbuf_release(&sb);
3490 break;
3491 case S_IFDIR:
3492 return resolve_gitlink_ref(path, "HEAD", sha1);
3493 default:
3494 return error("%s: unsupported file type", path);
3495 }
3496 return 0;
3497 }
3498
3499 int read_pack_header(int fd, struct pack_header *header)
3500 {
3501 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3502 /* "eof before pack header was fully read" */
3503 return PH_ERROR_EOF;
3504
3505 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3506 /* "protocol error (pack signature mismatch detected)" */
3507 return PH_ERROR_PACK_SIGNATURE;
3508 if (!pack_version_ok(header->hdr_version))
3509 /* "protocol error (pack version unsupported)" */
3510 return PH_ERROR_PROTOCOL;
3511 return 0;
3512 }
3513
3514 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3515 {
3516 enum object_type type = sha1_object_info(sha1, NULL);
3517 if (type < 0)
3518 die("%s is not a valid object", sha1_to_hex(sha1));
3519 if (type != expect)
3520 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3521 typename(expect));
3522 }
3523
3524 static int for_each_file_in_obj_subdir(int subdir_nr,
3525 struct strbuf *path,
3526 each_loose_object_fn obj_cb,
3527 each_loose_cruft_fn cruft_cb,
3528 each_loose_subdir_fn subdir_cb,
3529 void *data)
3530 {
3531 size_t baselen = path->len;
3532 DIR *dir = opendir(path->buf);
3533 struct dirent *de;
3534 int r = 0;
3535
3536 if (!dir) {
3537 if (errno == ENOENT)
3538 return 0;
3539 return error_errno("unable to open %s", path->buf);
3540 }
3541
3542 while ((de = readdir(dir))) {
3543 if (is_dot_or_dotdot(de->d_name))
3544 continue;
3545
3546 strbuf_setlen(path, baselen);
3547 strbuf_addf(path, "/%s", de->d_name);
3548
3549 if (strlen(de->d_name) == 38) {
3550 char hex[41];
3551 unsigned char sha1[20];
3552
3553 snprintf(hex, sizeof(hex), "%02x%s",
3554 subdir_nr, de->d_name);
3555 if (!get_sha1_hex(hex, sha1)) {
3556 if (obj_cb) {
3557 r = obj_cb(sha1, path->buf, data);
3558 if (r)
3559 break;
3560 }
3561 continue;
3562 }
3563 }
3564
3565 if (cruft_cb) {
3566 r = cruft_cb(de->d_name, path->buf, data);
3567 if (r)
3568 break;
3569 }
3570 }
3571 closedir(dir);
3572
3573 strbuf_setlen(path, baselen);
3574 if (!r && subdir_cb)
3575 r = subdir_cb(subdir_nr, path->buf, data);
3576
3577 return r;
3578 }
3579
3580 int for_each_loose_file_in_objdir_buf(struct strbuf *path,
3581 each_loose_object_fn obj_cb,
3582 each_loose_cruft_fn cruft_cb,
3583 each_loose_subdir_fn subdir_cb,
3584 void *data)
3585 {
3586 size_t baselen = path->len;
3587 int r = 0;
3588 int i;
3589
3590 for (i = 0; i < 256; i++) {
3591 strbuf_addf(path, "/%02x", i);
3592 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
3593 subdir_cb, data);
3594 strbuf_setlen(path, baselen);
3595 if (r)
3596 break;
3597 }
3598
3599 return r;
3600 }
3601
3602 int for_each_loose_file_in_objdir(const char *path,
3603 each_loose_object_fn obj_cb,
3604 each_loose_cruft_fn cruft_cb,
3605 each_loose_subdir_fn subdir_cb,
3606 void *data)
3607 {
3608 struct strbuf buf = STRBUF_INIT;
3609 int r;
3610
3611 strbuf_addstr(&buf, path);
3612 r = for_each_loose_file_in_objdir_buf(&buf, obj_cb, cruft_cb,
3613 subdir_cb, data);
3614 strbuf_release(&buf);
3615
3616 return r;
3617 }
3618
3619 struct loose_alt_odb_data {
3620 each_loose_object_fn *cb;
3621 void *data;
3622 };
3623
3624 static int loose_from_alt_odb(struct alternate_object_database *alt,
3625 void *vdata)
3626 {
3627 struct loose_alt_odb_data *data = vdata;
3628 struct strbuf buf = STRBUF_INIT;
3629 int r;
3630
3631 /* copy base not including trailing '/' */
3632 strbuf_add(&buf, alt->base, alt->name - alt->base - 1);
3633 r = for_each_loose_file_in_objdir_buf(&buf,
3634 data->cb, NULL, NULL,
3635 data->data);
3636 strbuf_release(&buf);
3637 return r;
3638 }
3639
3640 int for_each_loose_object(each_loose_object_fn cb, void *data, unsigned flags)
3641 {
3642 struct loose_alt_odb_data alt;
3643 int r;
3644
3645 r = for_each_loose_file_in_objdir(get_object_directory(),
3646 cb, NULL, NULL, data);
3647 if (r)
3648 return r;
3649
3650 if (flags & FOR_EACH_OBJECT_LOCAL_ONLY)
3651 return 0;
3652
3653 alt.cb = cb;
3654 alt.data = data;
3655 return foreach_alt_odb(loose_from_alt_odb, &alt);
3656 }
3657
3658 static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
3659 {
3660 uint32_t i;
3661 int r = 0;
3662
3663 for (i = 0; i < p->num_objects; i++) {
3664 const unsigned char *sha1 = nth_packed_object_sha1(p, i);
3665
3666 if (!sha1)
3667 return error("unable to get sha1 of object %u in %s",
3668 i, p->pack_name);
3669
3670 r = cb(sha1, p, i, data);
3671 if (r)
3672 break;
3673 }
3674 return r;
3675 }
3676
3677 int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
3678 {
3679 struct packed_git *p;
3680 int r = 0;
3681 int pack_errors = 0;
3682
3683 prepare_packed_git();
3684 for (p = packed_git; p; p = p->next) {
3685 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
3686 continue;
3687 if (open_pack_index(p)) {
3688 pack_errors = 1;
3689 continue;
3690 }
3691 r = for_each_object_in_pack(p, cb, data);
3692 if (r)
3693 break;
3694 }
3695 return r ? r : pack_errors;
3696 }