sha1_file: move delta base cache code up
[git/git.git] / sha1_file.c
CommitLineData
0fcfd160
LT
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 */
0fcfd160 9#include "cache.h"
6eac50d8 10#include "string-list.h"
697cc8ef 11#include "lockfile.h"
1f688557 12#include "delta.h"
a733cb60 13#include "pack.h"
8e440259
PE
14#include "blob.h"
15#include "commit.h"
4dd1fbc7 16#include "run-command.h"
8e440259
PE
17#include "tag.h"
18#include "tree.h"
c879daa2 19#include "tree-walk.h"
f35a6d3b 20#include "refs.h"
70f5d5d3 21#include "pack-revindex.h"
628522ec 22#include "sha1-lookup.h"
568508e7 23#include "bulk-checkin.h"
090ea126 24#include "streaming.h"
543c5caa 25#include "dir.h"
a73cdd21 26#include "mru.h"
12d95ef6 27#include "list.h"
c4c6effa 28#include "mergesort.h"
cf3c6352 29#include "quote.h"
0fcfd160 30
28bd70d8
JN
31#define SZ_FMT PRIuMAX
32static inline uintmax_t sz_fmt(size_t s) { return s; }
e05db0fd 33
96f1e58f 34const unsigned char null_sha1[20];
3e56e724 35const struct object_id null_oid;
8576fde6
JK
36const struct object_id empty_tree_oid = {
37 EMPTY_TREE_SHA1_BIN_LITERAL
38};
39const struct object_id empty_blob_oid = {
40 EMPTY_BLOB_SHA1_BIN_LITERAL
41};
88cd621d 42
c597ba80
NTND
43/*
44 * This is meant to hold a *small* number of objects that you would
45 * want read_sha1_file() to be able to return, but yet you do not want
46 * to write them into the object store (e.g. a browse-only
47 * application).
48 */
49static struct cached_object {
50 unsigned char sha1[20];
51 enum object_type type;
52 void *buf;
53 unsigned long size;
54} *cached_objects;
55static int cached_object_nr, cached_object_alloc;
56
57static struct cached_object empty_tree = {
dab0d410 58 EMPTY_TREE_SHA1_BIN_LITERAL,
c597ba80
NTND
59 OBJ_TREE,
60 "",
61 0
62};
63
64static struct cached_object *find_cached_object(const unsigned char *sha1)
65{
66 int i;
67 struct cached_object *co = cached_objects;
68
69 for (i = 0; i < cached_object_nr; i++, co++) {
70 if (!hashcmp(co->sha1, sha1))
71 return co;
72 }
73 if (!hashcmp(sha1, empty_tree.sha1))
74 return &empty_tree;
75 return NULL;
76}
77
90a6464b
JH
78int mkdir_in_gitdir(const char *path)
79{
80 if (mkdir(path, 0777)) {
81 int saved_errno = errno;
82 struct stat st;
83 struct strbuf sb = STRBUF_INIT;
84
85 if (errno != EEXIST)
86 return -1;
87 /*
88 * Are we looking at a path in a symlinked worktree
89 * whose original repository does not yet have it?
90 * e.g. .git/rr-cache pointing at its original
91 * repository in which the user hasn't performed any
92 * conflict resolution yet?
93 */
94 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
95 strbuf_readlink(&sb, path, st.st_size) ||
96 !is_absolute_path(sb.buf) ||
97 mkdir(sb.buf, 0777)) {
98 strbuf_release(&sb);
99 errno = saved_errno;
100 return -1;
101 }
102 strbuf_release(&sb);
103 }
104 return adjust_shared_perm(path);
105}
106
0be0521b 107enum scld_error safe_create_leading_directories(char *path)
b2cb9425 108{
26c8ae2a 109 char *next_component = path + offset_1st_component(path);
0be0521b 110 enum scld_error ret = SCLD_OK;
67d42212 111
0be0521b 112 while (ret == SCLD_OK && next_component) {
f0502332 113 struct stat st;
0f527403 114 char *slash = next_component, slash_character;
f0502332 115
0f527403
MH
116 while (*slash && !is_dir_sep(*slash))
117 slash++;
118
119 if (!*slash)
b2cb9425 120 break;
bf10cf70 121
26c8ae2a 122 next_component = slash + 1;
0f527403 123 while (is_dir_sep(*next_component))
bf10cf70 124 next_component++;
26c8ae2a 125 if (!*next_component)
5f0bdf50 126 break;
831651fd 127
0f527403 128 slash_character = *slash;
831651fd 129 *slash = '\0';
67d42212
JR
130 if (!stat(path, &st)) {
131 /* path exists */
204a047f
MH
132 if (!S_ISDIR(st.st_mode)) {
133 errno = ENOTDIR;
0be0521b 134 ret = SCLD_EXISTS;
204a047f 135 }
53a39721 136 } else if (mkdir(path, 0777)) {
928734d9 137 if (errno == EEXIST &&
9e6f885d 138 !stat(path, &st) && S_ISDIR(st.st_mode))
928734d9 139 ; /* somebody created it since we checked */
18d37e86
MH
140 else if (errno == ENOENT)
141 /*
142 * Either mkdir() failed because
143 * somebody just pruned the containing
144 * directory, or stat() failed because
145 * the file that was in our way was
146 * just removed. Either way, inform
147 * the caller that it might be worth
148 * trying again:
149 */
150 ret = SCLD_VANISHED;
9e6f885d 151 else
0be0521b 152 ret = SCLD_FAILED;
53a39721 153 } else if (adjust_shared_perm(path)) {
0be0521b 154 ret = SCLD_PERMS;
457f06d6 155 }
0f527403 156 *slash = slash_character;
b2cb9425 157 }
9e6f885d 158 return ret;
b2cb9425 159}
723c31fe 160
0be0521b 161enum scld_error safe_create_leading_directories_const(const char *path)
8e21d63b 162{
02944307 163 int save_errno;
8e21d63b
JK
164 /* path points to cache entries, so xstrdup before messing with it */
165 char *buf = xstrdup(path);
0be0521b 166 enum scld_error result = safe_create_leading_directories(buf);
02944307
MH
167
168 save_errno = errno;
8e21d63b 169 free(buf);
02944307 170 errno = save_errno;
8e21d63b
JK
171 return result;
172}
173
177978f5
MH
174int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
175{
176 /*
177 * The number of times we will try to remove empty directories
178 * in the way of path. This is only 1 because if another
179 * process is racily creating directories that conflict with
180 * us, we don't want to fight against them.
181 */
182 int remove_directories_remaining = 1;
183
184 /*
185 * The number of times that we will try to create the
186 * directories containing path. We are willing to attempt this
187 * more than once, because another process could be trying to
188 * clean up empty directories at the same time as we are
189 * trying to create them.
190 */
191 int create_directories_remaining = 3;
192
193 /* A scratch copy of path, filled lazily if we need it: */
194 struct strbuf path_copy = STRBUF_INIT;
195
196 int ret, save_errno;
197
198 /* Sanity check: */
199 assert(*path);
200
201retry_fn:
202 ret = fn(path, cb);
203 save_errno = errno;
204 if (!ret)
205 goto out;
206
207 if (errno == EISDIR && remove_directories_remaining-- > 0) {
208 /*
209 * A directory is in the way. Maybe it is empty; try
210 * to remove it:
211 */
212 if (!path_copy.len)
213 strbuf_addstr(&path_copy, path);
214
215 if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
216 goto retry_fn;
217 } else if (errno == ENOENT && create_directories_remaining-- > 0) {
218 /*
219 * Maybe the containing directory didn't exist, or
220 * maybe it was just deleted by a process that is
221 * racing with us to clean up empty directories. Try
222 * to create it:
223 */
224 enum scld_error scld_result;
225
226 if (!path_copy.len)
227 strbuf_addstr(&path_copy, path);
228
229 do {
230 scld_result = safe_create_leading_directories(path_copy.buf);
231 if (scld_result == SCLD_OK)
232 goto retry_fn;
233 } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
234 }
235
236out:
237 strbuf_release(&path_copy);
238 errno = save_errno;
239 return ret;
240}
241
f7b7774f 242static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
ace1534d
JH
243{
244 int i;
245 for (i = 0; i < 20; i++) {
246 static char hex[] = "0123456789abcdef";
247 unsigned int val = sha1[i];
f7b7774f
JK
248 strbuf_addch(buf, hex[val >> 4]);
249 strbuf_addch(buf, hex[val & 0xf]);
afbba2f0 250 if (!i)
f7b7774f 251 strbuf_addch(buf, '/');
ace1534d
JH
252 }
253}
254
30d6c6ea 255const char *sha1_file_name(const unsigned char *sha1)
0fcfd160 256{
f7b7774f 257 static struct strbuf buf = STRBUF_INIT;
0fcfd160 258
f7b7774f
JK
259 strbuf_reset(&buf);
260 strbuf_addf(&buf, "%s/", get_object_directory());
560fb6a1 261
f7b7774f
JK
262 fill_sha1_path(&buf, sha1);
263 return buf.buf;
0fcfd160
LT
264}
265
38dbe5f0
JK
266struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
267{
268 strbuf_setlen(&alt->scratch, alt->base_len);
269 return &alt->scratch;
270}
271
29ec6af2
JK
272static const char *alt_sha1_path(struct alternate_object_database *alt,
273 const unsigned char *sha1)
274{
38dbe5f0 275 struct strbuf *buf = alt_scratch_buf(alt);
f7b7774f 276 fill_sha1_path(buf, sha1);
38dbe5f0 277 return buf->buf;
0fcfd160
LT
278}
279
1cec8c63
JK
280 char *odb_pack_name(struct strbuf *buf,
281 const unsigned char *sha1,
282 const char *ext)
bf592c50 283{
ac5190cc
JK
284 strbuf_reset(buf);
285 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
1cec8c63 286 sha1_to_hex(sha1), ext);
ac5190cc 287 return buf->buf;
bf592c50
DB
288}
289
633f43e1 290char *sha1_pack_name(const unsigned char *sha1)
bf592c50 291{
ac5190cc 292 static struct strbuf buf = STRBUF_INIT;
1cec8c63 293 return odb_pack_name(&buf, sha1, "pack");
633f43e1 294}
bf592c50 295
633f43e1
HO
296char *sha1_pack_index_name(const unsigned char *sha1)
297{
ac5190cc 298 static struct strbuf buf = STRBUF_INIT;
1cec8c63 299 return odb_pack_name(&buf, sha1, "idx");
bf592c50
DB
300}
301
d5a63b99
JH
302struct alternate_object_database *alt_odb_list;
303static struct alternate_object_database **alt_odb_tail;
ace1534d 304
4ea82473
JK
305/*
306 * Return non-zero iff the path is usable as an alternate object database.
307 */
308static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
309{
310 struct alternate_object_database *alt;
311
312 /* Detect cases where alternate disappeared */
313 if (!is_directory(path->buf)) {
314 error("object directory %s does not exist; "
315 "check .git/objects/info/alternates.",
316 path->buf);
317 return 0;
318 }
319
320 /*
321 * Prevent the common mistake of listing the same
322 * thing twice, or object directory itself.
323 */
324 for (alt = alt_odb_list; alt; alt = alt->next) {
ea0fc3b4 325 if (!fspathcmp(path->buf, alt->path))
4ea82473
JK
326 return 0;
327 }
328 if (!fspathcmp(path->buf, normalized_objdir))
329 return 0;
330
331 return 1;
332}
333
ddd5d056
JH
334/*
335 * Prepare alternate object database registry.
d5a63b99
JH
336 *
337 * The variable alt_odb_list points at the list of struct
338 * alternate_object_database. The elements on this list come from
339 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
340 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
341 * whose contents is similar to that environment variable but can be
342 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
343 * contains "/the/directory/corresponding/to/.git/objects/...", while
344 * its name points just after the slash at the end of ".git/objects/"
345 * in the example above, and has enough space to hold 40-byte hex
346 * SHA1, an extra slash for the first level indirection, and the
347 * terminating NUL.
ddd5d056 348 */
539e7506
EK
349static int link_alt_odb_entry(const char *entry, const char *relative_base,
350 int depth, const char *normalized_objdir)
ace1534d 351{
c2f493a4 352 struct alternate_object_database *ent;
5bdf0a84 353 struct strbuf pathbuf = STRBUF_INIT;
d5a63b99 354
85dadc38 355 if (!is_absolute_path(entry) && relative_base) {
4ac9006f 356 strbuf_realpath(&pathbuf, relative_base, 1);
5bdf0a84 357 strbuf_addch(&pathbuf, '/');
c2f493a4 358 }
6eac50d8 359 strbuf_addstr(&pathbuf, entry);
c2f493a4 360
37a95862 361 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
670c359d
JK
362 error("unable to normalize alternate object path: %s",
363 pathbuf.buf);
364 strbuf_release(&pathbuf);
365 return -1;
366 }
5bdf0a84
HW
367
368 /*
369 * The trailing slash after the directory name is given by
370 * this function at the end. Remove duplicates.
371 */
4ea82473
JK
372 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
373 strbuf_setlen(&pathbuf, pathbuf.len - 1);
5bdf0a84 374
4ea82473
JK
375 if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
376 strbuf_release(&pathbuf);
c2f493a4
MW
377 return -1;
378 }
379
7f0fa2c0 380 ent = alloc_alt_odb(pathbuf.buf);
c2f493a4
MW
381
382 /* add the alternate entry */
383 *alt_odb_tail = ent;
384 alt_odb_tail = &(ent->next);
385 ent->next = NULL;
386
387 /* recursively add alternates */
4ea82473 388 read_info_alternates(pathbuf.buf, depth + 1);
c2f493a4 389
4ea82473 390 strbuf_release(&pathbuf);
c2f493a4
MW
391 return 0;
392}
393
cf3c6352
JK
394static const char *parse_alt_odb_entry(const char *string,
395 int sep,
396 struct strbuf *out)
397{
398 const char *end;
399
400 strbuf_reset(out);
401
402 if (*string == '#') {
403 /* comment; consume up to next separator */
404 end = strchrnul(string, sep);
405 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
406 /*
407 * quoted path; unquote_c_style has copied the
408 * data for us and set "end". Broken quoting (e.g.,
409 * an entry that doesn't end with a quote) falls
410 * back to the unquoted case below.
411 */
412 } else {
413 /* normal, unquoted path */
414 end = strchrnul(string, sep);
415 strbuf_add(out, string, end - string);
416 }
417
418 if (*end)
419 end++;
420 return end;
421}
422
c5950164 423static void link_alt_odb_entries(const char *alt, int len, int sep,
c2f493a4
MW
424 const char *relative_base, int depth)
425{
539e7506 426 struct strbuf objdirbuf = STRBUF_INIT;
cf3c6352 427 struct strbuf entry = STRBUF_INIT;
c2f493a4
MW
428
429 if (depth > 5) {
430 error("%s: ignoring alternate object stores, nesting too deep.",
431 relative_base);
432 return;
433 }
434
f655651e 435 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
670c359d
JK
436 if (strbuf_normalize_path(&objdirbuf) < 0)
437 die("unable to normalize object directory: %s",
438 objdirbuf.buf);
539e7506 439
cf3c6352
JK
440 while (*alt) {
441 alt = parse_alt_odb_entry(alt, sep, &entry);
442 if (!entry.len)
9577e7e3 443 continue;
cf3c6352 444 link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
9577e7e3 445 }
cf3c6352 446 strbuf_release(&entry);
539e7506 447 strbuf_release(&objdirbuf);
d5a63b99
JH
448}
449
5e73633d 450void read_info_alternates(const char * relative_base, int depth)
d5a63b99 451{
9577e7e3 452 char *map;
dc49cd76 453 size_t mapsz;
d5a63b99 454 struct stat st;
5015f01c 455 char *path;
c2f493a4 456 int fd;
d5a63b99 457
5015f01c 458 path = xstrfmt("%s/info/alternates", relative_base);
a5436b57 459 fd = git_open(path);
5015f01c 460 free(path);
d5a63b99
JH
461 if (fd < 0)
462 return;
463 if (fstat(fd, &st) || (st.st_size == 0)) {
464 close(fd);
9a217f2a 465 return;
ace1534d 466 }
dc49cd76
SP
467 mapsz = xsize_t(st.st_size);
468 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 469 close(fd);
d5a63b99 470
c5950164 471 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
c2f493a4 472
dc49cd76 473 munmap(map, mapsz);
ace1534d
JH
474}
475
7f0fa2c0
JK
476struct alternate_object_database *alloc_alt_odb(const char *dir)
477{
478 struct alternate_object_database *ent;
7f0fa2c0 479
597f9134 480 FLEX_ALLOC_STR(ent, path, dir);
38dbe5f0
JK
481 strbuf_init(&ent->scratch, 0);
482 strbuf_addf(&ent->scratch, "%s/", dir);
483 ent->base_len = ent->scratch.len;
7f0fa2c0
JK
484
485 return ent;
486}
487
bef70b22
DB
488void add_to_alternates_file(const char *reference)
489{
490 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
77b9b1d1
JK
491 char *alts = git_pathdup("objects/info/alternates");
492 FILE *in, *out;
493
494 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
495 out = fdopen_lock_file(lock, "w");
496 if (!out)
497 die_errno("unable to fdopen alternates lockfile");
498
499 in = fopen(alts, "r");
500 if (in) {
501 struct strbuf line = STRBUF_INIT;
502 int found = 0;
503
3f163962 504 while (strbuf_getline(&line, in) != EOF) {
77b9b1d1
JK
505 if (!strcmp(reference, line.buf)) {
506 found = 1;
507 break;
508 }
509 fprintf_or_die(out, "%s\n", line.buf);
510 }
511
512 strbuf_release(&line);
513 fclose(in);
514
515 if (found) {
516 rollback_lock_file(lock);
517 lock = NULL;
518 }
519 }
520 else if (errno != ENOENT)
521 die_errno("unable to read alternates file");
522
523 if (lock) {
524 fprintf_or_die(out, "%s\n", reference);
525 if (commit_lock_file(lock))
526 die_errno("unable to move new alternates file into place");
527 if (alt_odb_tail)
528 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
529 }
530 free(alts);
bef70b22
DB
531}
532
a5b34d21
JK
533void add_to_alternates_memory(const char *reference)
534{
535 /*
536 * Make sure alternates are initialized, or else our entry may be
537 * overwritten when they are.
538 */
539 prepare_alt_odb();
540
541 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
542}
543
9eeea7d2
SB
544/*
545 * Compute the exact path an alternate is at and returns it. In case of
546 * error NULL is returned and the human readable error is added to `err`
547 * `path` may be relative and should point to $GITDIR.
548 * `err` must not be null.
549 */
550char *compute_alternate_path(const char *path, struct strbuf *err)
551{
552 char *ref_git = NULL;
553 const char *repo, *ref_git_s;
554 int seen_error = 0;
555
556 ref_git_s = real_path_if_valid(path);
557 if (!ref_git_s) {
558 seen_error = 1;
559 strbuf_addf(err, _("path '%s' does not exist"), path);
560 goto out;
561 } else
562 /*
563 * Beware: read_gitfile(), real_path() and mkpath()
564 * return static buffer
565 */
566 ref_git = xstrdup(ref_git_s);
567
568 repo = read_gitfile(ref_git);
569 if (!repo)
570 repo = read_gitfile(mkpath("%s/.git", ref_git));
571 if (repo) {
572 free(ref_git);
573 ref_git = xstrdup(repo);
574 }
575
576 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
577 char *ref_git_git = mkpathdup("%s/.git", ref_git);
578 free(ref_git);
579 ref_git = ref_git_git;
580 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
581 struct strbuf sb = STRBUF_INIT;
582 seen_error = 1;
583 if (get_common_dir(&sb, ref_git)) {
584 strbuf_addf(err,
585 _("reference repository '%s' as a linked "
586 "checkout is not supported yet."),
587 path);
588 goto out;
589 }
590
591 strbuf_addf(err, _("reference repository '%s' is not a "
592 "local repository."), path);
593 goto out;
594 }
595
596 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
597 strbuf_addf(err, _("reference repository '%s' is shallow"),
598 path);
599 seen_error = 1;
600 goto out;
601 }
602
603 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
604 strbuf_addf(err,
605 _("reference repository '%s' is grafted"),
606 path);
607 seen_error = 1;
608 goto out;
609 }
610
611out:
612 if (seen_error) {
613 free(ref_git);
614 ref_git = NULL;
615 }
616
617 return ref_git;
618}
619
fe1b2268 620int foreach_alt_odb(alt_odb_fn fn, void *cb)
d79796bc
JH
621{
622 struct alternate_object_database *ent;
fe1b2268 623 int r = 0;
d79796bc
JH
624
625 prepare_alt_odb();
fe1b2268
JK
626 for (ent = alt_odb_list; ent; ent = ent->next) {
627 r = fn(ent, cb);
628 if (r)
629 break;
630 }
631 return r;
d79796bc
JH
632}
633
c2f493a4
MW
634void prepare_alt_odb(void)
635{
554fe20d 636 const char *alt;
c2f493a4 637
7dc24aa5
SP
638 if (alt_odb_tail)
639 return;
640
c2f493a4
MW
641 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
642 if (!alt) alt = "";
643
c2f493a4 644 alt_odb_tail = &alt_odb_list;
c5950164 645 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
646
647 read_info_alternates(get_object_directory(), 0);
648}
649
3096b2ec 650/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
33d4221c 651static int freshen_file(const char *fn)
ace1534d 652{
33d4221c
JK
653 struct utimbuf t;
654 t.actime = t.modtime = time(NULL);
655 return !utime(fn, &t);
0f4dc14a 656}
ace1534d 657
3096b2ec
JK
658/*
659 * All of the check_and_freshen functions return 1 if the file exists and was
660 * freshened (if freshening was requested), 0 otherwise. If they return
661 * 0, you should not assume that it is safe to skip a write of the object (it
662 * either does not exist on disk, or has a stale mtime and may be subject to
663 * pruning).
664 */
6a5e6f5e 665int check_and_freshen_file(const char *fn, int freshen)
33d4221c
JK
666{
667 if (access(fn, F_OK))
668 return 0;
3096b2ec 669 if (freshen && !freshen_file(fn))
33d4221c
JK
670 return 0;
671 return 1;
672}
673
674static int check_and_freshen_local(const unsigned char *sha1, int freshen)
675{
676 return check_and_freshen_file(sha1_file_name(sha1), freshen);
677}
678
679static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
0f4dc14a
BC
680{
681 struct alternate_object_database *alt;
9a217f2a 682 prepare_alt_odb();
d5a63b99 683 for (alt = alt_odb_list; alt; alt = alt->next) {
29ec6af2
JK
684 const char *path = alt_sha1_path(alt, sha1);
685 if (check_and_freshen_file(path, freshen))
c529d75a 686 return 1;
ace1534d 687 }
c529d75a 688 return 0;
ace1534d
JH
689}
690
33d4221c
JK
691static int check_and_freshen(const unsigned char *sha1, int freshen)
692{
693 return check_and_freshen_local(sha1, freshen) ||
694 check_and_freshen_nonlocal(sha1, freshen);
695}
696
697int has_loose_object_nonlocal(const unsigned char *sha1)
698{
699 return check_and_freshen_nonlocal(sha1, 0);
700}
701
0f4dc14a
BC
702static int has_loose_object(const unsigned char *sha1)
703{
33d4221c 704 return check_and_freshen(sha1, 0);
0f4dc14a
BC
705}
706
60bb8b14 707static unsigned int pack_used_ctr;
a53128b6
SP
708static unsigned int pack_mmap_calls;
709static unsigned int peak_pack_open_windows;
710static unsigned int pack_open_windows;
c7934306
SP
711static unsigned int pack_open_fds;
712static unsigned int pack_max_fds;
a53128b6 713static size_t peak_pack_mapped;
60bb8b14 714static size_t pack_mapped;
9a217f2a 715struct packed_git *packed_git;
1f688557 716
a73cdd21
JK
717static struct mru packed_git_mru_storage;
718struct mru *packed_git_mru = &packed_git_mru_storage;
719
b79d18c9 720void pack_report(void)
a53128b6
SP
721{
722 fprintf(stderr,
e05db0fd
PR
723 "pack_report: getpagesize() = %10" SZ_FMT "\n"
724 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
725 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
726 sz_fmt(getpagesize()),
727 sz_fmt(packed_git_window_size),
728 sz_fmt(packed_git_limit));
a53128b6
SP
729 fprintf(stderr,
730 "pack_report: pack_used_ctr = %10u\n"
731 "pack_report: pack_mmap_calls = %10u\n"
732 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
733 "pack_report: pack_mapped = "
734 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
735 pack_used_ctr,
736 pack_mmap_calls,
737 pack_open_windows, peak_pack_open_windows,
9e42d6a1 738 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
739}
740
d40d535b
MH
741/*
742 * Open and mmap the index file at path, perform a couple of
743 * consistency checks, then record its information to p. Return 0 on
744 * success.
745 */
746static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
747{
748 void *idx_map;
42873078 749 struct pack_idx_header *hdr;
dc49cd76 750 size_t idx_size;
74e34e1f 751 uint32_t version, nr, i, *index;
a5436b57 752 int fd = git_open(path);
1f688557 753 struct stat st;
42873078 754
1f688557
JH
755 if (fd < 0)
756 return -1;
757 if (fstat(fd, &st)) {
758 close(fd);
759 return -1;
760 }
dc49cd76 761 idx_size = xsize_t(st.st_size);
2d88451b
SP
762 if (idx_size < 4 * 256 + 20 + 20) {
763 close(fd);
764 return error("index file %s is too small", path);
765 }
c4712e45 766 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 767 close(fd);
1f688557 768
42873078
NP
769 hdr = idx_map;
770 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
771 version = ntohl(hdr->idx_version);
772 if (version < 2 || version > 2) {
773 munmap(idx_map, idx_size);
6e1c2344 774 return error("index file %s is version %"PRIu32
74e34e1f
NP
775 " and is not supported by this binary"
776 " (try upgrading GIT to a newer version)",
777 path, version);
778 }
779 } else
780 version = 1;
df1b059d 781
1f688557 782 nr = 0;
42873078 783 index = idx_map;
74e34e1f
NP
784 if (version > 1)
785 index += 2; /* skip index header */
1f688557 786 for (i = 0; i < 256; i++) {
326bf396 787 uint32_t n = ntohl(index[i]);
2d88451b
SP
788 if (n < nr) {
789 munmap(idx_map, idx_size);
df1b059d 790 return error("non-monotonic index %s", path);
2d88451b 791 }
1f688557
JH
792 nr = n;
793 }
794
74e34e1f
NP
795 if (version == 1) {
796 /*
797 * Total size:
798 * - 256 index entries 4 bytes each
799 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
800 * - 20-byte SHA1 of the packfile
801 * - 20-byte SHA1 file checksum
802 */
803 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
804 munmap(idx_map, idx_size);
eef427a0 805 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
806 }
807 } else if (version == 2) {
808 /*
809 * Minimum size:
810 * - 8 bytes of header
811 * - 256 index entries 4 bytes each
812 * - 20-byte sha1 entry * nr
813 * - 4-byte crc entry * nr
814 * - 4-byte offset entry * nr
815 * - 20-byte SHA1 of the packfile
816 * - 20-byte SHA1 file checksum
817 * And after the 4-byte offset table might be a
818 * variable sized table containing 8-byte entries
819 * for offsets larger than 2^31.
820 */
821 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
822 unsigned long max_size = min_size;
823 if (nr)
824 max_size += (nr - 1)*8;
825 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 826 munmap(idx_map, idx_size);
eef427a0 827 return error("wrong index v2 file size in %s", path);
74e34e1f 828 }
7109c889
JH
829 if (idx_size != min_size &&
830 /*
831 * make sure we can deal with large pack offsets.
832 * 31-bit signed offset won't be enough, neither
833 * 32-bit unsigned one will be.
834 */
835 (sizeof(off_t) <= 4)) {
836 munmap(idx_map, idx_size);
837 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 838 }
2d88451b 839 }
1f688557 840
74e34e1f 841 p->index_version = version;
42873078
NP
842 p->index_data = idx_map;
843 p->index_size = idx_size;
57059091 844 p->num_objects = nr;
1f688557
JH
845 return 0;
846}
847
bc8e478a 848int open_pack_index(struct packed_git *p)
d079837e
SP
849{
850 char *idx_name;
9ae97018 851 size_t len;
d079837e
SP
852 int ret;
853
854 if (p->index_data)
855 return 0;
856
9ae97018
JK
857 if (!strip_suffix(p->pack_name, ".pack", &len))
858 die("BUG: pack_name does not end in .pack");
859 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
d079837e
SP
860 ret = check_packed_git_idx(idx_name, p);
861 free(idx_name);
862 return ret;
863}
864
11daf39b
SP
865static void scan_windows(struct packed_git *p,
866 struct packed_git **lru_p,
867 struct pack_window **lru_w,
868 struct pack_window **lru_l)
1f688557 869{
11daf39b
SP
870 struct pack_window *w, *w_l;
871
872 for (w_l = NULL, w = p->windows; w; w = w->next) {
873 if (!w->inuse_cnt) {
874 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
875 *lru_p = p;
876 *lru_w = w;
877 *lru_l = w_l;
54044bf8 878 }
54044bf8 879 }
11daf39b 880 w_l = w;
f9253394 881 }
11daf39b
SP
882}
883
7c3ecb32 884static int unuse_one_window(struct packed_git *current)
11daf39b
SP
885{
886 struct packed_git *p, *lru_p = NULL;
887 struct pack_window *lru_w = NULL, *lru_l = NULL;
888
889 if (current)
890 scan_windows(current, &lru_p, &lru_w, &lru_l);
891 for (p = packed_git; p; p = p->next)
892 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
893 if (lru_p) {
894 munmap(lru_w->base, lru_w->len);
895 pack_mapped -= lru_w->len;
896 if (lru_l)
897 lru_l->next = lru_w->next;
7c3ecb32 898 else
54044bf8 899 lru_p->windows = lru_w->next;
54044bf8 900 free(lru_w);
a53128b6 901 pack_open_windows--;
54044bf8
SP
902 return 1;
903 }
904 return 0;
f9253394
JH
905}
906
7c3ecb32 907void release_pack_memory(size_t need)
97bfeb34
SP
908{
909 size_t cur = pack_mapped;
7c3ecb32 910 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
97bfeb34
SP
911 ; /* nothing */
912}
913
02710228
SP
914static void mmap_limit_check(size_t length)
915{
916 static size_t limit = 0;
917 if (!limit) {
918 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
919 if (!limit)
920 limit = SIZE_MAX;
921 }
922 if (length > limit)
923 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
924 (uintmax_t)length, (uintmax_t)limit);
925}
926
1570856b
JK
927void *xmmap_gently(void *start, size_t length,
928 int prot, int flags, int fd, off_t offset)
58ecbd5e 929{
02710228
SP
930 void *ret;
931
932 mmap_limit_check(length);
933 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
934 if (ret == MAP_FAILED) {
935 if (!length)
936 return NULL;
7c3ecb32 937 release_pack_memory(length);
58ecbd5e 938 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
939 }
940 return ret;
941}
942
1570856b
JK
943void *xmmap(void *start, size_t length,
944 int prot, int flags, int fd, off_t offset)
945{
946 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
947 if (ret == MAP_FAILED)
9ca0aaf6 948 die_errno("mmap failed");
1570856b
JK
949 return ret;
950}
951
c9ced051
SP
952void close_pack_windows(struct packed_git *p)
953{
954 while (p->windows) {
955 struct pack_window *w = p->windows;
956
957 if (w->inuse_cnt)
958 die("pack '%s' still has open windows to it",
959 p->pack_name);
960 munmap(w->base, w->len);
961 pack_mapped -= w->len;
962 pack_open_windows--;
963 p->windows = w->next;
964 free(w);
965 }
966}
967
71fe5d7f
JS
968static int close_pack_fd(struct packed_git *p)
969{
970 if (p->pack_fd < 0)
971 return 0;
972
973 close(p->pack_fd);
974 pack_open_fds--;
975 p->pack_fd = -1;
976
977 return 1;
978}
979
38849a81
JS
980static void close_pack(struct packed_git *p)
981{
982 close_pack_windows(p);
983 close_pack_fd(p);
984 close_pack_index(p);
985}
986
987void close_all_packs(void)
988{
989 struct packed_git *p;
990
991 for (p = packed_git; p; p = p->next)
992 if (p->do_not_close)
ef1177d1 993 die("BUG: want to close pack marked 'do-not-close'");
38849a81
JS
994 else
995 close_pack(p);
996}
997
998
88d0db55
BC
999/*
1000 * The LRU pack is the one with the oldest MRU window, preferring packs
1001 * with no used windows, or the oldest mtime if it has no windows allocated.
1002 */
1003static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
1004{
1005 struct pack_window *w, *this_mru_w;
1006 int has_windows_inuse = 0;
1007
1008 /*
1009 * Reject this pack if it has windows and the previously selected
1010 * one does not. If this pack does not have windows, reject
1011 * it if the pack file is newer than the previously selected one.
1012 */
1013 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
1014 return;
1015
1016 for (w = this_mru_w = p->windows; w; w = w->next) {
1017 /*
1018 * Reject this pack if any of its windows are in use,
1019 * but the previously selected pack did not have any
1020 * inuse windows. Otherwise, record that this pack
1021 * has windows in use.
1022 */
1023 if (w->inuse_cnt) {
1024 if (*accept_windows_inuse)
1025 has_windows_inuse = 1;
1026 else
1027 return;
1028 }
1029
1030 if (w->last_used > this_mru_w->last_used)
1031 this_mru_w = w;
1032
1033 /*
1034 * Reject this pack if it has windows that have been
1035 * used more recently than the previously selected pack.
1036 * If the previously selected pack had windows inuse and
1037 * we have not encountered a window in this pack that is
1038 * inuse, skip this check since we prefer a pack with no
1039 * inuse windows to one that has inuse windows.
1040 */
1041 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
1042 this_mru_w->last_used > (*mru_w)->last_used)
1043 return;
1044 }
1045
1046 /*
1047 * Select this pack.
1048 */
1049 *mru_w = this_mru_w;
1050 *lru_p = p;
1051 *accept_windows_inuse = has_windows_inuse;
1052}
1053
1054static int close_one_pack(void)
1055{
1056 struct packed_git *p, *lru_p = NULL;
1057 struct pack_window *mru_w = NULL;
1058 int accept_windows_inuse = 1;
1059
1060 for (p = packed_git; p; p = p->next) {
1061 if (p->pack_fd == -1)
1062 continue;
1063 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
1064 }
1065
71fe5d7f
JS
1066 if (lru_p)
1067 return close_pack_fd(lru_p);
88d0db55
BC
1068
1069 return 0;
1070}
1071
03e79c88 1072void unuse_pack(struct pack_window **w_cursor)
f9253394 1073{
03e79c88
SP
1074 struct pack_window *w = *w_cursor;
1075 if (w) {
1076 w->inuse_cnt--;
1077 *w_cursor = NULL;
1078 }
1f688557
JH
1079}
1080
fa5fc15d
SP
1081void close_pack_index(struct packed_git *p)
1082{
1083 if (p->index_data) {
1084 munmap((void *)p->index_data, p->index_size);
1085 p->index_data = NULL;
1086 }
1087}
1088
a0788266
JS
1089static unsigned int get_max_fd_limit(void)
1090{
1091#ifdef RLIMIT_NOFILE
491a8dec
JH
1092 {
1093 struct rlimit lim;
a0788266 1094
491a8dec
JH
1095 if (!getrlimit(RLIMIT_NOFILE, &lim))
1096 return lim.rlim_cur;
1097 }
1098#endif
1099
1100#ifdef _SC_OPEN_MAX
1101 {
1102 long open_max = sysconf(_SC_OPEN_MAX);
1103 if (0 < open_max)
1104 return open_max;
1105 /*
1106 * Otherwise, we got -1 for one of the two
1107 * reasons:
1108 *
1109 * (1) sysconf() did not understand _SC_OPEN_MAX
1110 * and signaled an error with -1; or
1111 * (2) sysconf() said there is no limit.
1112 *
1113 * We _could_ clear errno before calling sysconf() to
1114 * tell these two cases apart and return a huge number
1115 * in the latter case to let the caller cap it to a
1116 * value that is not so selfish, but letting the
1117 * fallback OPEN_MAX codepath take care of these cases
1118 * is a lot simpler.
1119 */
1120 }
1121#endif
a0788266 1122
491a8dec 1123#ifdef OPEN_MAX
a0788266
JS
1124 return OPEN_MAX;
1125#else
1126 return 1; /* see the caller ;-) */
1127#endif
1128}
1129
3cf8b462
SP
1130/*
1131 * Do not call this directly as this leaks p->pack_fd on error return;
1132 * call open_packed_git() instead.
1133 */
1134static int open_packed_git_1(struct packed_git *p)
1f688557 1135{
9bc879c1
SP
1136 struct stat st;
1137 struct pack_header hdr;
1138 unsigned char sha1[20];
1139 unsigned char *idx_sha1;
2c039da8 1140 long fd_flag;
9bc879c1 1141
d079837e
SP
1142 if (!p->index_data && open_pack_index(p))
1143 return error("packfile %s index unavailable", p->pack_name);
1144
c7934306 1145 if (!pack_max_fds) {
a0788266 1146 unsigned int max_fds = get_max_fd_limit();
c7934306
SP
1147
1148 /* Save 3 for stdin/stdout/stderr, 22 for work */
1149 if (25 < max_fds)
1150 pack_max_fds = max_fds - 25;
1151 else
1152 pack_max_fds = 1;
1153 }
1154
88d0db55 1155 while (pack_max_fds <= pack_open_fds && close_one_pack())
c7934306
SP
1156 ; /* nothing */
1157
a5436b57 1158 p->pack_fd = git_open(p->pack_name);
9bc879c1 1159 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 1160 return -1;
c7934306 1161 pack_open_fds++;
9bc879c1
SP
1162
1163 /* If we created the struct before we had the pack we lack size. */
bf592c50 1164 if (!p->pack_size) {
bf592c50 1165 if (!S_ISREG(st.st_mode))
072db278 1166 return error("packfile %s not a regular file", p->pack_name);
bf592c50 1167 p->pack_size = st.st_size;
9bc879c1 1168 } else if (p->pack_size != st.st_size)
072db278 1169 return error("packfile %s size changed", p->pack_name);
9bc879c1 1170
2c039da8
JH
1171 /* We leave these file descriptors open with sliding mmap;
1172 * there is no point keeping them open across exec(), though.
1173 */
1174 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
1175 if (fd_flag < 0)
072db278 1176 return error("cannot determine file descriptor flags");
2c039da8
JH
1177 fd_flag |= FD_CLOEXEC;
1178 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 1179 return error("cannot set FD_CLOEXEC");
2c039da8 1180
9bc879c1 1181 /* Verify we recognize this pack file format. */
e6e2bd62 1182 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 1183 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 1184 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 1185 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 1186 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
1187 return error("packfile %s is version %"PRIu32" and not"
1188 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
1189 p->pack_name, ntohl(hdr.hdr_version));
1190
1191 /* Verify the pack matches its index. */
57059091 1192 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
1193 return error("packfile %s claims to have %"PRIu32" objects"
1194 " while index indicates %"PRIu32" objects",
57059091
NP
1195 p->pack_name, ntohl(hdr.hdr_entries),
1196 p->num_objects);
9bc879c1 1197 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 1198 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 1199 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 1200 return error("packfile %s signature is unavailable", p->pack_name);
42873078 1201 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 1202 if (hashcmp(sha1, idx_sha1))
072db278
SP
1203 return error("packfile %s does not match index", p->pack_name);
1204 return 0;
9bc879c1
SP
1205}
1206
3cf8b462
SP
1207static int open_packed_git(struct packed_git *p)
1208{
1209 if (!open_packed_git_1(p))
1210 return 0;
71fe5d7f 1211 close_pack_fd(p);
3cf8b462
SP
1212 return -1;
1213}
1214
c4001d92 1215static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
1216{
1217 /* We must promise at least 20 bytes (one hash) after the
1218 * offset is available from this window, otherwise the offset
1219 * is not actually in this window and a different window (which
1220 * has that one hash excess) must be used. This is to support
1221 * the object header and delta base parsing routines below.
1222 */
1223 off_t win_off = win->offset;
1224 return win_off <= offset
1225 && (offset + 20) <= (win_off + win->len);
1226}
1227
4b25d091 1228unsigned char *use_pack(struct packed_git *p,
03e79c88 1229 struct pack_window **w_cursor,
c4001d92 1230 off_t offset,
ef49a7a0 1231 unsigned long *left)
9bc879c1 1232{
60bb8b14 1233 struct pack_window *win = *w_cursor;
03e79c88 1234
a9d98a14 1235 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
1236 * pointless to ask for an offset into the middle of that
1237 * hash, and the in_window function above wouldn't match
1238 * don't allow an offset too close to the end of the file.
1239 */
d131b7af
SP
1240 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1241 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
1242 if (offset > (p->pack_size - 20))
1243 die("offset beyond end of packfile (truncated pack?)");
13e0b0d3 1244 if (offset < 0)
7465feba 1245 die(_("offset before end of packfile (broken .idx?)"));
60bb8b14
SP
1246
1247 if (!win || !in_window(win, offset)) {
1248 if (win)
1249 win->inuse_cnt--;
1250 for (win = p->windows; win; win = win->next) {
1251 if (in_window(win, offset))
1252 break;
1253 }
1254 if (!win) {
78a28df9 1255 size_t window_align = packed_git_window_size / 2;
dc49cd76 1256 off_t len;
d131b7af
SP
1257
1258 if (p->pack_fd == -1 && open_packed_git(p))
1259 die("packfile %s cannot be accessed", p->pack_name);
1260
60bb8b14 1261 win = xcalloc(1, sizeof(*win));
78a28df9 1262 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
1263 len = p->pack_size - win->offset;
1264 if (len > packed_git_window_size)
1265 len = packed_git_window_size;
1266 win->len = (size_t)len;
60bb8b14 1267 pack_mapped += win->len;
11daf39b 1268 while (packed_git_limit < pack_mapped
7c3ecb32 1269 && unuse_one_window(p))
60bb8b14 1270 ; /* nothing */
c4712e45 1271 win->base = xmmap(NULL, win->len,
60bb8b14
SP
1272 PROT_READ, MAP_PRIVATE,
1273 p->pack_fd, win->offset);
1274 if (win->base == MAP_FAILED)
7616c6ca
NTND
1275 die_errno("packfile %s cannot be mapped",
1276 p->pack_name);
d131b7af 1277 if (!win->offset && win->len == p->pack_size
71fe5d7f
JS
1278 && !p->do_not_close)
1279 close_pack_fd(p);
a53128b6
SP
1280 pack_mmap_calls++;
1281 pack_open_windows++;
1282 if (pack_mapped > peak_pack_mapped)
1283 peak_pack_mapped = pack_mapped;
1284 if (pack_open_windows > peak_pack_open_windows)
1285 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
1286 win->next = p->windows;
1287 p->windows = win;
1288 }
1f688557 1289 }
03e79c88
SP
1290 if (win != *w_cursor) {
1291 win->last_used = pack_used_ctr++;
1292 win->inuse_cnt++;
1293 *w_cursor = win;
1294 }
60bb8b14 1295 offset -= win->offset;
03e79c88 1296 if (left)
dc49cd76 1297 *left = win->len - xsize_t(offset);
03e79c88 1298 return win->base + offset;
1f688557
JH
1299}
1300
27d69a46
NP
1301static struct packed_git *alloc_packed_git(int extra)
1302{
50a6c8ef 1303 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
27d69a46
NP
1304 memset(p, 0, sizeof(*p));
1305 p->pack_fd = -1;
1306 return p;
1307}
1308
e0500293
JN
1309static void try_to_free_pack_memory(size_t size)
1310{
7c3ecb32 1311 release_pack_memory(size);
e0500293
JN
1312}
1313
48bcc1c3 1314struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1f688557 1315{
e0500293 1316 static int have_set_try_to_free_routine;
1f688557 1317 struct stat st;
48bcc1c3
JK
1318 size_t alloc;
1319 struct packed_git *p;
1f688557 1320
e0500293
JN
1321 if (!have_set_try_to_free_routine) {
1322 have_set_try_to_free_routine = 1;
1323 set_try_to_free_routine(try_to_free_pack_memory);
1324 }
1325
42873078
NP
1326 /*
1327 * Make sure a corresponding .pack file exists and that
1328 * the index looks sane.
1329 */
48bcc1c3 1330 if (!strip_suffix_mem(path, &path_len, ".idx"))
1f688557 1331 return NULL;
48bcc1c3
JK
1332
1333 /*
1334 * ".pack" is long enough to hold any suffix we're adding (and
1335 * the use xsnprintf double-checks that)
1336 */
50a6c8ef 1337 alloc = st_add3(path_len, strlen(".pack"), 1);
48bcc1c3 1338 p = alloc_packed_git(alloc);
42873078 1339 memcpy(p->pack_name, path, path_len);
8d25931d 1340
48bcc1c3 1341 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
8d25931d
BC
1342 if (!access(p->pack_name, F_OK))
1343 p->pack_keep = 1;
1344
48bcc1c3 1345 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
d079837e 1346 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 1347 free(p);
1f688557
JH
1348 return NULL;
1349 }
42873078 1350
1f688557
JH
1351 /* ok, it looks sane as far as we can check without
1352 * actually mapping the pack file.
1353 */
1f688557 1354 p->pack_size = st.st_size;
9d835df2 1355 p->pack_local = local;
b867092f 1356 p->mtime = st.st_mtime;
42873078
NP
1357 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1358 hashclr(p->sha1);
1f688557
JH
1359 return p;
1360}
1361
7b64469a 1362struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 1363{
42873078 1364 const char *path = sha1_pack_name(sha1);
50a6c8ef 1365 size_t alloc = st_add(strlen(path), 1);
c7ab0ba3 1366 struct packed_git *p = alloc_packed_git(alloc);
bf592c50 1367
c7ab0ba3 1368 memcpy(p->pack_name, path, alloc); /* includes NUL */
27d69a46 1369 hashcpy(p->sha1, sha1);
42873078
NP
1370 if (check_packed_git_idx(idx_path, p)) {
1371 free(p);
bf592c50 1372 return NULL;
42873078 1373 }
bf592c50 1374
bf592c50
DB
1375 return p;
1376}
1377
1378void install_packed_git(struct packed_git *pack)
1379{
c7934306
SP
1380 if (pack->pack_fd != -1)
1381 pack_open_fds++;
1382
bf592c50
DB
1383 pack->next = packed_git;
1384 packed_git = pack;
1385}
1386
0a489b06 1387void (*report_garbage)(unsigned seen_bits, const char *path);
543c5caa
NTND
1388
1389static void report_helper(const struct string_list *list,
1390 int seen_bits, int first, int last)
1391{
0a489b06 1392 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
543c5caa 1393 return;
0a489b06 1394
543c5caa 1395 for (; first < last; first++)
0a489b06 1396 report_garbage(seen_bits, list->items[first].string);
543c5caa
NTND
1397}
1398
1399static void report_pack_garbage(struct string_list *list)
1400{
1401 int i, baselen = -1, first = 0, seen_bits = 0;
1402
1403 if (!report_garbage)
1404 return;
1405
3383e199 1406 string_list_sort(list);
543c5caa
NTND
1407
1408 for (i = 0; i < list->nr; i++) {
1409 const char *path = list->items[i].string;
1410 if (baselen != -1 &&
1411 strncmp(path, list->items[first].string, baselen)) {
1412 report_helper(list, seen_bits, first, i);
1413 baselen = -1;
1414 seen_bits = 0;
1415 }
1416 if (baselen == -1) {
1417 const char *dot = strrchr(path, '.');
1418 if (!dot) {
0a489b06 1419 report_garbage(PACKDIR_FILE_GARBAGE, path);
543c5caa
NTND
1420 continue;
1421 }
1422 baselen = dot - path + 1;
1423 first = i;
1424 }
1425 if (!strcmp(path + baselen, "pack"))
1426 seen_bits |= 1;
1427 else if (!strcmp(path + baselen, "idx"))
1428 seen_bits |= 2;
1429 }
1430 report_helper(list, seen_bits, first, list->nr);
1431}
1432
9d835df2 1433static void prepare_packed_git_one(char *objdir, int local)
1f688557 1434{
880fb8de
RS
1435 struct strbuf path = STRBUF_INIT;
1436 size_t dirnamelen;
1f688557
JH
1437 DIR *dir;
1438 struct dirent *de;
543c5caa 1439 struct string_list garbage = STRING_LIST_INIT_DUP;
1f688557 1440
880fb8de
RS
1441 strbuf_addstr(&path, objdir);
1442 strbuf_addstr(&path, "/pack");
1443 dir = opendir(path.buf);
b5b16990 1444 if (!dir) {
26125f6b 1445 if (errno != ENOENT)
7616c6ca
NTND
1446 error_errno("unable to open object pack directory: %s",
1447 path.buf);
880fb8de 1448 strbuf_release(&path);
1f688557 1449 return;
b5b16990 1450 }
880fb8de
RS
1451 strbuf_addch(&path, '/');
1452 dirnamelen = path.len;
1f688557 1453 while ((de = readdir(dir)) != NULL) {
1f688557 1454 struct packed_git *p;
47bf4b0f 1455 size_t base_len;
543c5caa
NTND
1456
1457 if (is_dot_or_dotdot(de->d_name))
9cb18f56
JM
1458 continue;
1459
880fb8de
RS
1460 strbuf_setlen(&path, dirnamelen);
1461 strbuf_addstr(&path, de->d_name);
d90906a9 1462
47bf4b0f
JK
1463 base_len = path.len;
1464 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
d90906a9
NTND
1465 /* Don't reopen a pack we already have. */
1466 for (p = packed_git; p; p = p->next) {
47bf4b0f
JK
1467 size_t len;
1468 if (strip_suffix(p->pack_name, ".pack", &len) &&
1469 len == base_len &&
1470 !memcmp(p->pack_name, path.buf, len))
d90906a9
NTND
1471 break;
1472 }
1473 if (p == NULL &&
1474 /*
1475 * See if it really is a valid .idx file with
1476 * corresponding .pack file that we can map.
1477 */
880fb8de 1478 (p = add_packed_git(path.buf, path.len, local)) != NULL)
d90906a9 1479 install_packed_git(p);
86f7780c 1480 }
543c5caa
NTND
1481
1482 if (!report_garbage)
1483 continue;
1484
2975c770
JK
1485 if (ends_with(de->d_name, ".idx") ||
1486 ends_with(de->d_name, ".pack") ||
1487 ends_with(de->d_name, ".bitmap") ||
1488 ends_with(de->d_name, ".keep"))
880fb8de 1489 string_list_append(&garbage, path.buf);
543c5caa 1490 else
0a489b06 1491 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1f688557 1492 }
5b35bcd5 1493 closedir(dir);
543c5caa
NTND
1494 report_pack_garbage(&garbage);
1495 string_list_clear(&garbage, 0);
880fb8de 1496 strbuf_release(&path);
1f688557
JH
1497}
1498
8e3f52d7
JK
1499static int approximate_object_count_valid;
1500
1501/*
1502 * Give a fast, rough count of the number of objects in the repository. This
1503 * ignores loose objects completely. If you have a lot of them, then either
1504 * you should repack because your performance will be awful, or they are
1505 * all unreachable objects about to be pruned, in which case they're not really
1506 * interesting as a measure of repo size in the first place.
1507 */
1508unsigned long approximate_object_count(void)
1509{
1510 static unsigned long count;
1511 if (!approximate_object_count_valid) {
1512 struct packed_git *p;
1513
1514 prepare_packed_git();
1515 count = 0;
1516 for (p = packed_git; p; p = p->next) {
1517 if (open_pack_index(p))
1518 continue;
1519 count += p->num_objects;
1520 }
1521 }
1522 return count;
1523}
1524
c4c6effa
RS
1525static void *get_next_packed_git(const void *p)
1526{
1527 return ((const struct packed_git *)p)->next;
1528}
1529
1530static void set_next_packed_git(void *p, void *next)
1531{
1532 ((struct packed_git *)p)->next = next;
1533}
1534
b867092f
JH
1535static int sort_pack(const void *a_, const void *b_)
1536{
c4c6effa
RS
1537 const struct packed_git *a = a_;
1538 const struct packed_git *b = b_;
b867092f
JH
1539 int st;
1540
1541 /*
1542 * Local packs tend to contain objects specific to our
1543 * variant of the project than remote ones. In addition,
1544 * remote ones could be on a network mounted filesystem.
1545 * Favor local ones for these reasons.
1546 */
1547 st = a->pack_local - b->pack_local;
1548 if (st)
1549 return -st;
1550
1551 /*
1552 * Younger packs tend to contain more recent objects,
1553 * and more recent objects tend to get accessed more
1554 * often.
1555 */
1556 if (a->mtime < b->mtime)
1557 return 1;
1558 else if (a->mtime == b->mtime)
1559 return 0;
1560 return -1;
1561}
1562
1563static void rearrange_packed_git(void)
1564{
c4c6effa
RS
1565 packed_git = llist_mergesort(packed_git, get_next_packed_git,
1566 set_next_packed_git, sort_pack);
b867092f
JH
1567}
1568
a73cdd21
JK
1569static void prepare_packed_git_mru(void)
1570{
1571 struct packed_git *p;
1572
1573 mru_clear(packed_git_mru);
1574 for (p = packed_git; p; p = p->next)
1575 mru_append(packed_git_mru, p);
1576}
1577
637cdd9d 1578static int prepare_packed_git_run_once = 0;
9a217f2a 1579void prepare_packed_git(void)
1f688557 1580{
d5a63b99 1581 struct alternate_object_database *alt;
1f688557 1582
637cdd9d 1583 if (prepare_packed_git_run_once)
1f688557 1584 return;
9d835df2 1585 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1586 prepare_alt_odb();
597f9134
JK
1587 for (alt = alt_odb_list; alt; alt = alt->next)
1588 prepare_packed_git_one(alt->path, 0);
b867092f 1589 rearrange_packed_git();
a73cdd21 1590 prepare_packed_git_mru();
637cdd9d
JK
1591 prepare_packed_git_run_once = 1;
1592}
1593
fc04c412 1594void reprepare_packed_git(void)
637cdd9d 1595{
8e3f52d7 1596 approximate_object_count_valid = 0;
637cdd9d
JK
1597 prepare_packed_git_run_once = 0;
1598 prepare_packed_git();
1f688557
JH
1599}
1600
8eca0b47
NP
1601static void mark_bad_packed_object(struct packed_git *p,
1602 const unsigned char *sha1)
1603{
1604 unsigned i;
1605 for (i = 0; i < p->num_bad_objects; i++)
50a6c8ef 1606 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
8eca0b47 1607 return;
50a6c8ef 1608 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
cd02599c 1609 st_mult(GIT_MAX_RAWSZ,
50a6c8ef
JK
1610 st_add(p->num_bad_objects, 1)));
1611 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
8eca0b47
NP
1612 p->num_bad_objects++;
1613}
1614
b6c4cecc 1615static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1616{
1617 struct packed_git *p;
1618 unsigned i;
1619
1620 for (p = packed_git; p; p = p->next)
1621 for (i = 0; i < p->num_bad_objects; i++)
1622 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1623 return p;
1624 return NULL;
ac939109
NP
1625}
1626
090ea126
NTND
1627/*
1628 * With an in-core object data in "map", rehash it to make sure the
1629 * object name actually matches "sha1" to detect object corruption.
1630 * With "map" == NULL, try reading the object named with "sha1" using
1631 * the streaming interface and rehash it to do the same.
1632 */
1633int check_sha1_signature(const unsigned char *sha1, void *map,
1634 unsigned long size, const char *type)
0fcfd160
LT
1635{
1636 unsigned char real_sha1[20];
090ea126
NTND
1637 enum object_type obj_type;
1638 struct git_istream *st;
1639 git_SHA_CTX c;
1640 char hdr[32];
1641 int hdrlen;
1642
1643 if (map) {
1644 hash_sha1_file(map, size, type, real_sha1);
1645 return hashcmp(sha1, real_sha1) ? -1 : 0;
1646 }
1647
1648 st = open_istream(sha1, &obj_type, &size, NULL);
1649 if (!st)
1650 return -1;
1651
1652 /* Generate the header */
ef1286d3 1653 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
090ea126
NTND
1654
1655 /* Sha1.. */
1656 git_SHA1_Init(&c);
1657 git_SHA1_Update(&c, hdr, hdrlen);
1658 for (;;) {
1659 char buf[1024 * 16];
1660 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1661
f54fac53
JK
1662 if (readlen < 0) {
1663 close_istream(st);
1664 return -1;
1665 }
090ea126
NTND
1666 if (!readlen)
1667 break;
1668 git_SHA1_Update(&c, buf, readlen);
1669 }
1670 git_SHA1_Final(real_sha1, &c);
1671 close_istream(st);
a89fccd2 1672 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1673}
1674
1b8ac5ea 1675int git_open_cloexec(const char *name, int flags)
44d1c19e 1676{
1e3001a8
JH
1677 int fd;
1678 static int o_cloexec = O_CLOEXEC;
f2e872aa 1679
1e3001a8
JH
1680 fd = open(name, flags | o_cloexec);
1681 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
cd66ada0 1682 /* Try again w/o O_CLOEXEC: the kernel might not support it */
1e3001a8
JH
1683 o_cloexec &= ~O_CLOEXEC;
1684 fd = open(name, flags | o_cloexec);
1b8ac5ea 1685 }
f2e872aa 1686
1e3001a8
JH
1687#if defined(F_GETFL) && defined(F_SETFL) && defined(FD_CLOEXEC)
1688 {
1689 static int fd_cloexec = FD_CLOEXEC;
1690
1691 if (!o_cloexec && 0 <= fd && fd_cloexec) {
1692 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
1693 int flags = fcntl(fd, F_GETFL);
1694 if (fcntl(fd, F_SETFL, flags | fd_cloexec))
1695 fd_cloexec = 0;
cd66ada0 1696 }
44d1c19e 1697 }
1e3001a8 1698#endif
1b8ac5ea 1699 return fd;
44d1c19e
LT
1700}
1701
771e7d57
JK
1702/*
1703 * Find "sha1" as a loose object in the local repository or in an alternate.
1704 * Returns 0 on success, negative on failure.
1705 *
1706 * The "path" out-parameter will give the path of the object we found (if any).
1707 * Note that it may point to static storage and is only valid until another
1708 * call to sha1_file_name(), etc.
1709 */
1710static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
1711 const char **path)
052fe5ea 1712{
052fe5ea
JK
1713 struct alternate_object_database *alt;
1714
771e7d57
JK
1715 *path = sha1_file_name(sha1);
1716 if (!lstat(*path, st))
052fe5ea
JK
1717 return 0;
1718
1719 prepare_alt_odb();
1720 errno = ENOENT;
1721 for (alt = alt_odb_list; alt; alt = alt->next) {
771e7d57
JK
1722 *path = alt_sha1_path(alt, sha1);
1723 if (!lstat(*path, st))
052fe5ea
JK
1724 return 0;
1725 }
1726
1727 return -1;
1728}
1729
771e7d57
JK
1730/*
1731 * Like stat_sha1_file(), but actually open the object and return the
1732 * descriptor. See the caveats on the "path" parameter above.
1733 */
1734static int open_sha1_file(const unsigned char *sha1, const char **path)
44d1c19e
LT
1735{
1736 int fd;
44d1c19e 1737 struct alternate_object_database *alt;
d6c8a05b 1738 int most_interesting_errno;
44d1c19e 1739
771e7d57
JK
1740 *path = sha1_file_name(sha1);
1741 fd = git_open(*path);
44d1c19e
LT
1742 if (fd >= 0)
1743 return fd;
d6c8a05b 1744 most_interesting_errno = errno;
44d1c19e
LT
1745
1746 prepare_alt_odb();
44d1c19e 1747 for (alt = alt_odb_list; alt; alt = alt->next) {
771e7d57
JK
1748 *path = alt_sha1_path(alt, sha1);
1749 fd = git_open(*path);
44d1c19e
LT
1750 if (fd >= 0)
1751 return fd;
d6c8a05b
JK
1752 if (most_interesting_errno == ENOENT)
1753 most_interesting_errno = errno;
44d1c19e 1754 }
d6c8a05b 1755 errno = most_interesting_errno;
44d1c19e
LT
1756 return -1;
1757}
1758
f6371f92
JK
1759/*
1760 * Map the loose object at "path" if it is not NULL, or the path found by
1761 * searching for a loose object named "sha1".
1762 */
1763static void *map_sha1_file_1(const char *path,
1764 const unsigned char *sha1,
1765 unsigned long *size)
0fcfd160 1766{
0fcfd160 1767 void *map;
144bde78 1768 int fd;
ace1534d 1769
f6371f92
JK
1770 if (path)
1771 fd = git_open(path);
1772 else
1773 fd = open_sha1_file(sha1, &path);
44d1c19e
LT
1774 map = NULL;
1775 if (fd >= 0) {
1776 struct stat st;
0fcfd160 1777
44d1c19e
LT
1778 if (!fstat(fd, &st)) {
1779 *size = xsize_t(st.st_size);
33e42de0
MM
1780 if (!*size) {
1781 /* mmap() is forbidden on empty files */
771e7d57 1782 error("object file %s is empty", path);
33e42de0
MM
1783 return NULL;
1784 }
44d1c19e 1785 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1786 }
44d1c19e 1787 close(fd);
0fcfd160 1788 }
0fcfd160
LT
1789 return map;
1790}
1791
f6371f92
JK
1792void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1793{
1794 return map_sha1_file_1(NULL, sha1, size);
1795}
1796
09ded04b
NP
1797unsigned long unpack_object_header_buffer(const unsigned char *buf,
1798 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1799{
ad1ed5ee 1800 unsigned shift;
48fb7deb 1801 unsigned long size, c;
ad1ed5ee
JH
1802 unsigned long used = 0;
1803
1804 c = buf[used++];
1805 *type = (c >> 4) & 7;
1806 size = c & 15;
1807 shift = 4;
1808 while (c & 0x80) {
f630cfda 1809 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1810 error("bad object header");
ea4f9685
JH
1811 size = used = 0;
1812 break;
09ded04b 1813 }
ad1ed5ee
JH
1814 c = buf[used++];
1815 size += (c & 0x7f) << shift;
1816 shift += 7;
1817 }
1818 *sizep = size;
1819 return used;
1820}
1821
d21f8426
JH
1822static int unpack_sha1_short_header(git_zstream *stream,
1823 unsigned char *map, unsigned long mapsize,
1824 void *buffer, unsigned long bufsiz)
ad1ed5ee 1825{
c4483576
LT
1826 /* Get the data stream */
1827 memset(stream, 0, sizeof(*stream));
1828 stream->next_in = map;
1829 stream->avail_in = mapsize;
1830 stream->next_out = buffer;
93821bd9
LT
1831 stream->avail_out = bufsiz;
1832
39c68542 1833 git_inflate_init(stream);
cc5c54e7 1834 return git_inflate(stream, 0);
c4483576
LT
1835}
1836
d21f8426
JH
1837int unpack_sha1_header(git_zstream *stream,
1838 unsigned char *map, unsigned long mapsize,
1839 void *buffer, unsigned long bufsiz)
1840{
1841 int status = unpack_sha1_short_header(stream, map, mapsize,
1842 buffer, bufsiz);
1843
1844 if (status < Z_OK)
1845 return status;
1846
1847 /* Make sure we have the terminating NUL */
1848 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1849 return -1;
1850 return 0;
1851}
1852
46f03448
KN
1853static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1854 unsigned long mapsize, void *buffer,
1855 unsigned long bufsiz, struct strbuf *header)
1856{
1857 int status;
1858
d21f8426
JH
1859 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
1860 if (status < Z_OK)
1861 return -1;
46f03448
KN
1862
1863 /*
1864 * Check if entire header is unpacked in the first iteration.
1865 */
1866 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1867 return 0;
1868
1869 /*
1870 * buffer[0..bufsiz] was not large enough. Copy the partial
1871 * result out to header, and then append the result of further
1872 * reading the stream.
1873 */
1874 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1875 stream->next_out = buffer;
1876 stream->avail_out = bufsiz;
1877
1878 do {
1879 status = git_inflate(stream, 0);
1880 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1881 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1882 return 0;
1883 stream->next_out = buffer;
1884 stream->avail_out = bufsiz;
1885 } while (status != Z_STREAM_END);
1886 return -1;
1887}
1888
ef49a7a0 1889static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1890{
1891 int bytes = strlen(buffer) + 1;
3aee68aa 1892 unsigned char *buf = xmallocz(size);
93821bd9 1893 unsigned long n;
7efbff75 1894 int status = Z_OK;
5180cacc 1895
93821bd9
LT
1896 n = stream->total_out - bytes;
1897 if (n > size)
1898 n = size;
1899 memcpy(buf, (char *) buffer + bytes, n);
1900 bytes = n;
456cdf6e
LT
1901 if (bytes <= size) {
1902 /*
1903 * The above condition must be (bytes <= size), not
1904 * (bytes < size). In other words, even though we
ccf5ace0 1905 * expect no more output and set avail_out to zero,
456cdf6e
LT
1906 * the input zlib stream may have bytes that express
1907 * "this concludes the stream", and we *do* want to
1908 * eat that input.
1909 *
1910 * Otherwise we would not be able to test that we
1911 * consumed all the input to reach the expected size;
1912 * we also want to check that zlib tells us that all
1913 * went well with status == Z_STREAM_END at the end.
1914 */
5180cacc
LT
1915 stream->next_out = buf + bytes;
1916 stream->avail_out = size - bytes;
7efbff75 1917 while (status == Z_OK)
39c68542 1918 status = git_inflate(stream, Z_FINISH);
5180cacc 1919 }
456cdf6e 1920 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1921 git_inflate_end(stream);
7efbff75
JH
1922 return buf;
1923 }
1924
1925 if (status < 0)
1926 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1927 else if (stream->avail_in)
1928 error("garbage at end of loose object '%s'",
1929 sha1_to_hex(sha1));
1930 free(buf);
1931 return NULL;
5180cacc
LT
1932}
1933
1934/*
1935 * We used to just use "sscanf()", but that's actually way
1936 * too permissive for what we want to check. So do an anal
1937 * object header parse by hand.
1938 */
46f03448
KN
1939static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1940 unsigned int flags)
5180cacc 1941{
46f03448 1942 const char *type_buf = hdr;
5180cacc 1943 unsigned long size;
46f03448 1944 int type, type_len = 0;
5180cacc
LT
1945
1946 /*
46f03448 1947 * The type can be of any size but is followed by
21666f1a 1948 * a space.
5180cacc 1949 */
5180cacc
LT
1950 for (;;) {
1951 char c = *hdr++;
d21f8426
JH
1952 if (!c)
1953 return -1;
5180cacc
LT
1954 if (c == ' ')
1955 break;
46f03448 1956 type_len++;
5180cacc 1957 }
46f03448
KN
1958
1959 type = type_from_string_gently(type_buf, type_len, 1);
1960 if (oi->typename)
1961 strbuf_add(oi->typename, type_buf, type_len);
1962 /*
1963 * Set type to 0 if its an unknown object and
2e3a16b2 1964 * we're obtaining the type using '--allow-unknown-type'
46f03448
KN
1965 * option.
1966 */
19fc5e84 1967 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
46f03448
KN
1968 type = 0;
1969 else if (type < 0)
1970 die("invalid object type");
1971 if (oi->typep)
1972 *oi->typep = type;
5180cacc
LT
1973
1974 /*
1975 * The length must follow immediately, and be in canonical
1976 * decimal format (ie "010" is not valid).
1977 */
1978 size = *hdr++ - '0';
1979 if (size > 9)
1980 return -1;
1981 if (size) {
1982 for (;;) {
1983 unsigned long c = *hdr - '0';
1984 if (c > 9)
1985 break;
1986 hdr++;
1987 size = size * 10 + c;
1988 }
1989 }
46f03448
KN
1990
1991 if (oi->sizep)
1992 *oi->sizep = size;
5180cacc
LT
1993
1994 /*
1995 * The length must be followed by a zero byte
1996 */
46f03448
KN
1997 return *hdr ? -1 : type;
1998}
1999
2000int parse_sha1_header(const char *hdr, unsigned long *sizep)
2001{
27b5c1a0 2002 struct object_info oi = OBJECT_INFO_INIT;
46f03448
KN
2003
2004 oi.sizep = sizep;
1f0c0d36 2005 return parse_sha1_header_extended(hdr, &oi, 0);
5180cacc
LT
2006}
2007
7efbff75 2008static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 2009{
5180cacc 2010 int ret;
ef49a7a0 2011 git_zstream stream;
5180cacc 2012 char hdr[8192];
0fcfd160 2013
5180cacc 2014 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 2015 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
2016 return NULL;
2017
7efbff75 2018 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
2019}
2020
54dab52a
NP
2021unsigned long get_size_from_delta(struct packed_git *p,
2022 struct pack_window **w_curs,
2023 off_t curpos)
2024{
2025 const unsigned char *data;
2026 unsigned char delta_head[20], *in;
ef49a7a0 2027 git_zstream stream;
54dab52a
NP
2028 int st;
2029
2030 memset(&stream, 0, sizeof(stream));
2031 stream.next_out = delta_head;
2032 stream.avail_out = sizeof(delta_head);
2033
39c68542 2034 git_inflate_init(&stream);
54dab52a
NP
2035 do {
2036 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2037 stream.next_in = in;
39c68542 2038 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
2039 curpos += stream.next_in - in;
2040 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
2041 stream.total_out < sizeof(delta_head));
39c68542 2042 git_inflate_end(&stream);
3d77d877
NP
2043 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
2044 error("delta data unpack-initial failed");
2045 return 0;
2046 }
54dab52a
NP
2047
2048 /* Examine the initial part of the delta to figure out
2049 * the result size.
2050 */
2051 data = delta_head;
2052
2053 /* ignore base size */
2054 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2055
2056 /* Read the result size */
2057 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2058}
2059
c4001d92 2060static off_t get_delta_base(struct packed_git *p,
03e79c88 2061 struct pack_window **w_curs,
c4001d92 2062 off_t *curpos,
21666f1a 2063 enum object_type type,
c4001d92 2064 off_t delta_obj_offset)
eb32d236 2065{
2b87c45b 2066 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 2067 off_t base_offset;
eb32d236 2068
8d8a4ea5
SP
2069 /* use_pack() assured us we have [base_info, base_info + 20)
2070 * as a range that we can look at without walking off the
2071 * end of the mapped window. Its actually the hash size
2072 * that is assured. An OFS_DELTA longer than the hash size
2073 * is stupid, as then a REF_DELTA would be smaller to store.
2074 */
21666f1a 2075 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
2076 unsigned used = 0;
2077 unsigned char c = base_info[used++];
2078 base_offset = c & 127;
2079 while (c & 128) {
2080 base_offset += 1;
8723f216 2081 if (!base_offset || MSB(base_offset, 7))
8eca0b47 2082 return 0; /* overflow */
eb32d236
NP
2083 c = base_info[used++];
2084 base_offset = (base_offset << 7) + (c & 127);
2085 }
2086 base_offset = delta_obj_offset - base_offset;
d8f32556 2087 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 2088 return 0; /* out of bound */
2b87c45b 2089 *curpos += used;
21666f1a 2090 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
2091 /* The base entry _must_ be in the same pack */
2092 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 2093 *curpos += 20;
eb32d236
NP
2094 } else
2095 die("I am totally screwed");
2b87c45b 2096 return base_offset;
eb32d236
NP
2097}
2098
5d642e75
JK
2099/*
2100 * Like get_delta_base above, but we return the sha1 instead of the pack
2101 * offset. This means it is cheaper for REF deltas (we do not have to do
2102 * the final object lookup), but more expensive for OFS deltas (we
2103 * have to load the revidx to convert the offset back into a sha1).
2104 */
2105static const unsigned char *get_delta_base_sha1(struct packed_git *p,
2106 struct pack_window **w_curs,
2107 off_t curpos,
2108 enum object_type type,
2109 off_t delta_obj_offset)
2110{
2111 if (type == OBJ_REF_DELTA) {
2112 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
2113 return base;
2114 } else if (type == OBJ_OFS_DELTA) {
2115 struct revindex_entry *revidx;
2116 off_t base_offset = get_delta_base(p, w_curs, &curpos,
2117 type, delta_obj_offset);
2118
2119 if (!base_offset)
2120 return NULL;
2121
2122 revidx = find_pack_revindex(p, base_offset);
2123 if (!revidx)
2124 return NULL;
2125
2126 return nth_packed_object_sha1(p, revidx->nr);
2127 } else
2128 return NULL;
2129}
2130
f8c8abc5
JH
2131int unpack_object_header(struct packed_git *p,
2132 struct pack_window **w_curs,
2133 off_t *curpos,
2134 unsigned long *sizep)
a733cb60 2135{
03e79c88 2136 unsigned char *base;
ef49a7a0 2137 unsigned long left;
ad1ed5ee 2138 unsigned long used;
2b87c45b 2139 enum object_type type;
a733cb60 2140
8d8a4ea5 2141 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 2142 * as a range that we can look at. (Its actually the hash
3dff5379 2143 * size that is assured.) With our object header encoding
8d8a4ea5
SP
2144 * the maximum deflated object size is 2^137, which is just
2145 * insane, so we know won't exceed what we have been given.
2146 */
2b87c45b 2147 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
2148 used = unpack_object_header_buffer(base, left, &type, sizep);
2149 if (!used) {
2150 type = OBJ_BAD;
2151 } else
2152 *curpos += used;
ad1ed5ee 2153
2b87c45b 2154 return type;
a733cb60
LT
2155}
2156
790d96c0
TR
2157static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
2158{
2159 int type;
2160 struct revindex_entry *revidx;
2161 const unsigned char *sha1;
2162 revidx = find_pack_revindex(p, obj_offset);
2163 if (!revidx)
2164 return OBJ_BAD;
2165 sha1 = nth_packed_object_sha1(p, revidx->nr);
2166 mark_bad_packed_object(p, sha1);
2167 type = sha1_object_info(sha1, NULL);
2168 if (type <= OBJ_NONE)
2169 return OBJ_BAD;
2170 return type;
2171}
2172
790d96c0
TR
2173#define POI_STACK_PREALLOC 64
2174
90191d37
JK
2175static enum object_type packed_to_object_type(struct packed_git *p,
2176 off_t obj_offset,
2177 enum object_type type,
2178 struct pack_window **w_curs,
2179 off_t curpos)
1f688557 2180{
790d96c0
TR
2181 off_t small_poi_stack[POI_STACK_PREALLOC];
2182 off_t *poi_stack = small_poi_stack;
2183 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
5db47c2b 2184
790d96c0
TR
2185 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2186 off_t base_offset;
90191d37 2187 unsigned long size;
790d96c0
TR
2188 /* Push the object we're going to leave behind */
2189 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
2190 poi_stack_alloc = alloc_nr(poi_stack_nr);
b32fa95f 2191 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
790d96c0
TR
2192 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
2193 } else {
2194 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
2195 }
2196 poi_stack[poi_stack_nr++] = obj_offset;
2197 /* If parsing the base offset fails, just unwind */
90191d37 2198 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
790d96c0
TR
2199 if (!base_offset)
2200 goto unwind;
2201 curpos = obj_offset = base_offset;
90191d37 2202 type = unpack_object_header(p, w_curs, &curpos, &size);
790d96c0
TR
2203 if (type <= OBJ_NONE) {
2204 /* If getting the base itself fails, we first
2205 * retry the base, otherwise unwind */
2206 type = retry_bad_packed_offset(p, base_offset);
2207 if (type > OBJ_NONE)
2208 goto out;
2209 goto unwind;
2210 }
2211 }
2212
21666f1a 2213 switch (type) {
790d96c0 2214 case OBJ_BAD:
a733cb60 2215 case OBJ_COMMIT:
a733cb60 2216 case OBJ_TREE:
a733cb60 2217 case OBJ_BLOB:
a733cb60 2218 case OBJ_TAG:
a69d0943 2219 break;
1f688557 2220 default:
3d77d877
NP
2221 error("unknown object type %i at offset %"PRIuMAX" in %s",
2222 type, (uintmax_t)obj_offset, p->pack_name);
2223 type = OBJ_BAD;
1f688557 2224 }
790d96c0
TR
2225
2226out:
2227 if (poi_stack != small_poi_stack)
2228 free(poi_stack);
21666f1a 2229 return type;
790d96c0
TR
2230
2231unwind:
2232 while (poi_stack_nr) {
2233 obj_offset = poi_stack[--poi_stack_nr];
2234 type = retry_bad_packed_offset(p, obj_offset);
2235 if (type > OBJ_NONE)
2236 goto out;
2237 }
2238 type = OBJ_BAD;
2239 goto out;
1f688557
JH
2240}
2241
8261e1f1 2242static struct hashmap delta_base_cache;
18bdec11 2243static size_t delta_base_cached;
5e08ecbf 2244
12d95ef6 2245static LIST_HEAD(delta_base_cache_lru);
5e08ecbf 2246
8261e1f1 2247struct delta_base_cache_key {
e5e01619
LT
2248 struct packed_git *p;
2249 off_t base_offset;
8261e1f1
JK
2250};
2251
2252struct delta_base_cache_entry {
2253 struct hashmap hash;
2254 struct delta_base_cache_key key;
2255 struct list_head lru;
2256 void *data;
e5e01619 2257 unsigned long size;
e5e01619 2258 enum object_type type;
8261e1f1 2259};
e5e01619 2260
8261e1f1 2261static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
e5e01619 2262{
8261e1f1 2263 unsigned int hash;
e5e01619 2264
8261e1f1 2265 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
e5e01619 2266 hash += (hash >> 8) + (hash >> 16);
8261e1f1 2267 return hash;
e5e01619
LT
2268}
2269
84dd81c1
TR
2270static struct delta_base_cache_entry *
2271get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
5266d369 2272{
8261e1f1
JK
2273 struct hashmap_entry entry;
2274 struct delta_base_cache_key key;
2275
2276 if (!delta_base_cache.cmpfn)
2277 return NULL;
2278
2279 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
2280 key.p = p;
2281 key.base_offset = base_offset;
2282 return hashmap_get(&delta_base_cache, &entry, &key);
2283}
2284
2285static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
2286 const struct delta_base_cache_key *b)
2287{
2288 return a->p == b->p && a->base_offset == b->base_offset;
84dd81c1
TR
2289}
2290
8261e1f1
JK
2291static int delta_base_cache_hash_cmp(const void *va, const void *vb,
2292 const void *vkey)
84dd81c1 2293{
8261e1f1
JK
2294 const struct delta_base_cache_entry *a = va, *b = vb;
2295 const struct delta_base_cache_key *key = vkey;
2296 if (key)
2297 return !delta_base_cache_key_eq(&a->key, key);
2298 else
2299 return !delta_base_cache_key_eq(&a->key, &b->key);
5266d369
JH
2300}
2301
84dd81c1
TR
2302static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2303{
8261e1f1 2304 return !!get_delta_base_cache_entry(p, base_offset);
84dd81c1
TR
2305}
2306
4a5397ca
JK
2307/*
2308 * Remove the entry from the cache, but do _not_ free the associated
2309 * entry data. The caller takes ownership of the "data" buffer, and
2310 * should copy out any fields it wants before detaching.
2311 */
2312static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
84dd81c1 2313{
8261e1f1 2314 hashmap_remove(&delta_base_cache, ent, &ent->key);
12d95ef6 2315 list_del(&ent->lru);
84dd81c1 2316 delta_base_cached -= ent->size;
8261e1f1 2317 free(ent);
84dd81c1
TR
2318}
2319
62f255ad 2320static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
85fe35ab 2321 unsigned long *base_size, enum object_type *type)
62f255ad 2322{
84dd81c1 2323 struct delta_base_cache_entry *ent;
e5e01619 2324
84dd81c1 2325 ent = get_delta_base_cache_entry(p, base_offset);
8261e1f1 2326 if (!ent)
749bc58c 2327 return unpack_entry(p, base_offset, type, base_size);
e5e01619 2328
e5e01619
LT
2329 *type = ent->type;
2330 *base_size = ent->size;
85fe35ab 2331 return xmemdupz(ent->data, ent->size);
62f255ad
LT
2332}
2333
18bdec11
SP
2334static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2335{
8261e1f1
JK
2336 free(ent->data);
2337 detach_delta_base_cache_entry(ent);
18bdec11
SP
2338}
2339
3d20c636
SP
2340void clear_delta_base_cache(void)
2341{
abd5a002
JK
2342 struct list_head *lru, *tmp;
2343 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2344 struct delta_base_cache_entry *entry =
2345 list_entry(lru, struct delta_base_cache_entry, lru);
8261e1f1
JK
2346 release_delta_base_cache(entry);
2347 }
3d20c636
SP
2348}
2349
62f255ad
LT
2350static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2351 void *base, unsigned long base_size, enum object_type type)
2352{
8261e1f1 2353 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
4b92bae7 2354 struct list_head *lru, *tmp;
e5e01619 2355
18bdec11 2356 delta_base_cached += base_size;
5e08ecbf 2357
4b92bae7 2358 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
12d95ef6
JK
2359 struct delta_base_cache_entry *f =
2360 list_entry(lru, struct delta_base_cache_entry, lru);
2361 if (delta_base_cached <= delta_base_cache_limit)
2362 break;
5e08ecbf
NP
2363 release_delta_base_cache(f);
2364 }
18bdec11 2365
8261e1f1
JK
2366 ent->key.p = p;
2367 ent->key.base_offset = base_offset;
e5e01619
LT
2368 ent->type = type;
2369 ent->data = base;
2370 ent->size = base_size;
12d95ef6 2371 list_add_tail(&ent->lru, &delta_base_cache_lru);
8261e1f1
JK
2372
2373 if (!delta_base_cache.cmpfn)
2374 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, 0);
2375 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
2376 hashmap_add(&delta_base_cache, ent);
62f255ad
LT
2377}
2378
845b102b
JT
2379int packed_object_info(struct packed_git *p, off_t obj_offset,
2380 struct object_info *oi)
2381{
2382 struct pack_window *w_curs = NULL;
2383 unsigned long size;
2384 off_t curpos = obj_offset;
2385 enum object_type type;
2386
2387 /*
2388 * We always get the representation type, but only convert it to
2389 * a "real" type later if the caller is interested.
2390 */
2391 type = unpack_object_header(p, &w_curs, &curpos, &size);
2392
2393 if (oi->sizep) {
2394 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2395 off_t tmp_pos = curpos;
2396 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2397 type, obj_offset);
2398 if (!base_offset) {
2399 type = OBJ_BAD;
2400 goto out;
2401 }
2402 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2403 if (*oi->sizep == 0) {
2404 type = OBJ_BAD;
2405 goto out;
2406 }
2407 } else {
2408 *oi->sizep = size;
2409 }
2410 }
2411
2412 if (oi->disk_sizep) {
2413 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2414 *oi->disk_sizep = revidx[1].offset - obj_offset;
2415 }
2416
2417 if (oi->typep || oi->typename) {
2418 enum object_type ptot;
2419 ptot = packed_to_object_type(p, obj_offset, type, &w_curs,
2420 curpos);
2421 if (oi->typep)
2422 *oi->typep = ptot;
2423 if (oi->typename) {
2424 const char *tn = typename(ptot);
2425 if (tn)
2426 strbuf_addstr(oi->typename, tn);
2427 }
2428 if (ptot < 0) {
2429 type = OBJ_BAD;
2430 goto out;
2431 }
2432 }
2433
2434 if (oi->delta_base_sha1) {
2435 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2436 const unsigned char *base;
2437
2438 base = get_delta_base_sha1(p, &w_curs, curpos,
2439 type, obj_offset);
2440 if (!base) {
2441 type = OBJ_BAD;
2442 goto out;
2443 }
2444
2445 hashcpy(oi->delta_base_sha1, base);
2446 } else
2447 hashclr(oi->delta_base_sha1);
2448 }
2449
2450out:
2451 unuse_pack(&w_curs);
2452 return type;
2453}
2454
2455static void *unpack_compressed_entry(struct packed_git *p,
2456 struct pack_window **w_curs,
2457 off_t curpos,
2458 unsigned long size)
2459{
2460 int st;
2461 git_zstream stream;
2462 unsigned char *buffer, *in;
2463
2464 buffer = xmallocz_gently(size);
2465 if (!buffer)
2466 return NULL;
2467 memset(&stream, 0, sizeof(stream));
2468 stream.next_out = buffer;
2469 stream.avail_out = size + 1;
2470
2471 git_inflate_init(&stream);
2472 do {
2473 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2474 stream.next_in = in;
2475 st = git_inflate(&stream, Z_FINISH);
2476 if (!stream.avail_out)
2477 break; /* the payload is larger than it should be */
2478 curpos += stream.next_in - in;
2479 } while (st == Z_OK || st == Z_BUF_ERROR);
2480 git_inflate_end(&stream);
2481 if ((st != Z_STREAM_END) || stream.total_out != size) {
2482 free(buffer);
2483 return NULL;
2484 }
2485
2486 return buffer;
2487}
2488
c2c5b270
CC
2489static void *read_object(const unsigned char *sha1, enum object_type *type,
2490 unsigned long *size);
2491
5f44324d
JH
2492static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2493{
67dc598e
KB
2494 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2495 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2496 p->pack_name, (uintmax_t)obj_offset);
5f44324d
JH
2497}
2498
0e8189e2
NP
2499int do_check_packed_object_crc;
2500
abe601bb
TR
2501#define UNPACK_ENTRY_STACK_PREALLOC 64
2502struct unpack_entry_stack_ent {
2503 off_t obj_offset;
2504 off_t curpos;
2505 unsigned long size;
2506};
2507
c4001d92 2508void *unpack_entry(struct packed_git *p, off_t obj_offset,
abe601bb 2509 enum object_type *final_type, unsigned long *final_size)
1f688557 2510{
03e79c88 2511 struct pack_window *w_curs = NULL;
c4001d92 2512 off_t curpos = obj_offset;
abe601bb
TR
2513 void *data = NULL;
2514 unsigned long size;
2515 enum object_type type;
2516 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2517 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2518 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2519 int base_from_cache = 0;
1f688557 2520
67dc598e 2521 write_pack_access_log(p, obj_offset);
5f44324d 2522
abe601bb
TR
2523 /* PHASE 1: drill down to the innermost base object */
2524 for (;;) {
2525 off_t base_offset;
2526 int i;
2527 struct delta_base_cache_entry *ent;
2528
77965f8b 2529 ent = get_delta_base_cache_entry(p, curpos);
8261e1f1 2530 if (ent) {
77965f8b
NTND
2531 type = ent->type;
2532 data = ent->data;
2533 size = ent->size;
4a5397ca 2534 detach_delta_base_cache_entry(ent);
77965f8b
NTND
2535 base_from_cache = 1;
2536 break;
2537 }
2538
abe601bb
TR
2539 if (do_check_packed_object_crc && p->index_version > 1) {
2540 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
211c61c6 2541 off_t len = revidx[1].offset - obj_offset;
abe601bb
TR
2542 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2543 const unsigned char *sha1 =
2544 nth_packed_object_sha1(p, revidx->nr);
2545 error("bad packed object CRC for %s",
2546 sha1_to_hex(sha1));
2547 mark_bad_packed_object(p, sha1);
2548 unuse_pack(&w_curs);
2549 return NULL;
2550 }
2551 }
2552
abe601bb
TR
2553 type = unpack_object_header(p, &w_curs, &curpos, &size);
2554 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2555 break;
2556
2557 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2558 if (!base_offset) {
2559 error("failed to validate delta base reference "
2560 "at offset %"PRIuMAX" from %s",
2561 (uintmax_t)curpos, p->pack_name);
2562 /* bail to phase 2, in hopes of recovery */
2563 data = NULL;
2564 break;
2565 }
2566
2567 /* push object, proceed to base */
2568 if (delta_stack_nr >= delta_stack_alloc
2569 && delta_stack == small_delta_stack) {
2570 delta_stack_alloc = alloc_nr(delta_stack_nr);
b32fa95f 2571 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
abe601bb
TR
2572 memcpy(delta_stack, small_delta_stack,
2573 sizeof(*delta_stack)*delta_stack_nr);
2574 } else {
2575 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2576 }
2577 i = delta_stack_nr++;
2578 delta_stack[i].obj_offset = obj_offset;
2579 delta_stack[i].curpos = curpos;
2580 delta_stack[i].size = size;
2581
2582 curpos = obj_offset = base_offset;
0e8189e2
NP
2583 }
2584
abe601bb
TR
2585 /* PHASE 2: handle the base */
2586 switch (type) {
eb32d236
NP
2587 case OBJ_OFS_DELTA:
2588 case OBJ_REF_DELTA:
abe601bb 2589 if (data)
ef1177d1 2590 die("BUG: unpack_entry: left loop at a valid delta");
4d703a1a 2591 break;
a733cb60 2592 case OBJ_COMMIT:
a733cb60 2593 case OBJ_TREE:
a733cb60 2594 case OBJ_BLOB:
a733cb60 2595 case OBJ_TAG:
abe601bb
TR
2596 if (!base_from_cache)
2597 data = unpack_compressed_entry(p, &w_curs, curpos, size);
4d703a1a 2598 break;
1f688557 2599 default:
8eca0b47
NP
2600 data = NULL;
2601 error("unknown object type %i at offset %"PRIuMAX" in %s",
abe601bb
TR
2602 type, (uintmax_t)obj_offset, p->pack_name);
2603 }
2604
2605 /* PHASE 3: apply deltas in order */
2606
2607 /* invariants:
2608 * 'data' holds the base data, or NULL if there was corruption
2609 */
2610 while (delta_stack_nr) {
2611 void *delta_data;
2612 void *base = data;
886ddf47 2613 void *external_base = NULL;
abe601bb
TR
2614 unsigned long delta_size, base_size = size;
2615 int i;
2616
2617 data = NULL;
2618
2619 if (base)
2620 add_delta_base_cache(p, obj_offset, base, base_size, type);
2621
2622 if (!base) {
2623 /*
2624 * We're probably in deep shit, but let's try to fetch
2625 * the required base anyway from another pack or loose.
2626 * This is costly but should happen only in the presence
2627 * of a corrupted pack, and is better than failing outright.
2628 */
2629 struct revindex_entry *revidx;
2630 const unsigned char *base_sha1;
2631 revidx = find_pack_revindex(p, obj_offset);
2632 if (revidx) {
2633 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2634 error("failed to read delta base object %s"
2635 " at offset %"PRIuMAX" from %s",
2636 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2637 p->pack_name);
2638 mark_bad_packed_object(p, base_sha1);
2639 base = read_object(base_sha1, &type, &base_size);
886ddf47 2640 external_base = base;
abe601bb
TR
2641 }
2642 }
2643
2644 i = --delta_stack_nr;
2645 obj_offset = delta_stack[i].obj_offset;
2646 curpos = delta_stack[i].curpos;
2647 delta_size = delta_stack[i].size;
2648
2649 if (!base)
2650 continue;
2651
2652 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2653
2654 if (!delta_data) {
2655 error("failed to unpack compressed delta "
2656 "at offset %"PRIuMAX" from %s",
2657 (uintmax_t)curpos, p->pack_name);
abe601bb 2658 data = NULL;
886ddf47 2659 free(external_base);
abe601bb
TR
2660 continue;
2661 }
2662
2663 data = patch_delta(base, base_size,
2664 delta_data, delta_size,
2665 &size);
1ee886c1
JK
2666
2667 /*
2668 * We could not apply the delta; warn the user, but keep going.
2669 * Our failure will be noticed either in the next iteration of
2670 * the loop, or if this is the final delta, in the caller when
2671 * we return NULL. Those code paths will take care of making
2672 * a more explicit warning and retrying with another copy of
2673 * the object.
2674 */
abe601bb 2675 if (!data)
1ee886c1 2676 error("failed to apply delta");
abe601bb 2677
4b8f772c 2678 free(delta_data);
886ddf47 2679 free(external_base);
1f688557 2680 }
abe601bb
TR
2681
2682 *final_type = type;
2683 *final_size = size;
2684
03e79c88 2685 unuse_pack(&w_curs);
019d1e65
NTND
2686
2687 if (delta_stack != small_delta_stack)
2688 free(delta_stack);
2689
21666f1a 2690 return data;
1f688557
JH
2691}
2692
d079837e 2693const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 2694 uint32_t n)
9a217f2a 2695{
42873078 2696 const unsigned char *index = p->index_data;
d079837e
SP
2697 if (!index) {
2698 if (open_pack_index(p))
2699 return NULL;
2700 index = p->index_data;
2701 }
57059091 2702 if (n >= p->num_objects)
d72308e0 2703 return NULL;
74e34e1f
NP
2704 index += 4 * 256;
2705 if (p->index_version == 1) {
2706 return index + 24 * n + 4;
2707 } else {
2708 index += 8;
2709 return index + 20 * n;
2710 }
2711}
2712
068f85e3 2713const struct object_id *nth_packed_object_oid(struct object_id *oid,
2714 struct packed_git *p,
2715 uint32_t n)
2716{
2717 const unsigned char *hash = nth_packed_object_sha1(p, n);
2718 if (!hash)
2719 return NULL;
2720 hashcpy(oid->hash, hash);
2721 return oid;
2722}
2723
47fe3f6e
JK
2724void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2725{
2726 const unsigned char *ptr = vptr;
2727 const unsigned char *start = p->index_data;
2728 const unsigned char *end = start + p->index_size;
2729 if (ptr < start)
7465feba 2730 die(_("offset before start of pack index for %s (corrupt index?)"),
47fe3f6e
JK
2731 p->pack_name);
2732 /* No need to check for underflow; .idx files must be at least 8 bytes */
2733 if (ptr >= end - 8)
7465feba 2734 die(_("offset beyond end of pack index for %s (truncated index?)"),
47fe3f6e
JK
2735 p->pack_name);
2736}
2737
99093238 2738off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
2739{
2740 const unsigned char *index = p->index_data;
2741 index += 4 * 256;
2742 if (p->index_version == 1) {
2743 return ntohl(*((uint32_t *)(index + 24 * n)));
2744 } else {
2745 uint32_t off;
2746 index += 8 + p->num_objects * (20 + 4);
2747 off = ntohl(*((uint32_t *)(index + 4 * n)));
2748 if (!(off & 0x80000000))
2749 return off;
2750 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
47fe3f6e 2751 check_pack_index_ptr(p, index);
74e34e1f
NP
2752 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2753 ntohl(*((uint32_t *)(index + 4)));
2754 }
9a217f2a
JH
2755}
2756
c4001d92 2757off_t find_pack_entry_one(const unsigned char *sha1,
43057304 2758 struct packed_git *p)
1f688557 2759{
42873078 2760 const uint32_t *level1_ofs = p->index_data;
42873078 2761 const unsigned char *index = p->index_data;
628522ec
JH
2762 unsigned hi, lo, stride;
2763 static int use_lookup = -1;
2764 static int debug_lookup = -1;
2765
2766 if (debug_lookup < 0)
2767 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 2768
d079837e
SP
2769 if (!index) {
2770 if (open_pack_index(p))
2771 return 0;
2772 level1_ofs = p->index_data;
2773 index = p->index_data;
2774 }
74e34e1f
NP
2775 if (p->index_version > 1) {
2776 level1_ofs += 2;
2777 index += 8;
2778 }
42873078 2779 index += 4 * 256;
74e34e1f
NP
2780 hi = ntohl(level1_ofs[*sha1]);
2781 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2782 if (p->index_version > 1) {
2783 stride = 20;
2784 } else {
2785 stride = 24;
2786 index += 4;
2787 }
2788
2789 if (debug_lookup)
6e1c2344 2790 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2791 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2792
2793 if (use_lookup < 0)
2794 use_lookup = !!getenv("GIT_USE_LOOKUP");
2795 if (use_lookup) {
2796 int pos = sha1_entry_pos(index, stride, 0,
2797 lo, hi, p->num_objects, sha1);
2798 if (pos < 0)
2799 return 0;
2800 return nth_packed_object_offset(p, pos);
2801 }
1f688557
JH
2802
2803 do {
74e34e1f 2804 unsigned mi = (lo + hi) / 2;
628522ec
JH
2805 int cmp = hashcmp(index + mi * stride, sha1);
2806
2807 if (debug_lookup)
2808 printf("lo %u hi %u rg %u mi %u\n",
2809 lo, hi, hi - lo, mi);
43057304 2810 if (!cmp)
74e34e1f 2811 return nth_packed_object_offset(p, mi);
1f688557
JH
2812 if (cmp > 0)
2813 hi = mi;
2814 else
2815 lo = mi+1;
2816 } while (lo < hi);
2817 return 0;
2818}
2819
4c080182 2820int is_pack_valid(struct packed_git *p)
d131b7af
SP
2821{
2822 /* An already open pack is known to be valid. */
2823 if (p->pack_fd != -1)
2824 return 1;
2825
2826 /* If the pack has one window completely covering the
2827 * file size, the pack is known to be valid even if
2828 * the descriptor is not currently open.
2829 */
2830 if (p->windows) {
2831 struct pack_window *w = p->windows;
2832
2833 if (!w->offset && w->len == p->pack_size)
2834 return 1;
2835 }
2836
2837 /* Force the pack to open to prove its valid. */
2838 return !open_packed_git(p);
2839}
2840
95099731
NTND
2841static int fill_pack_entry(const unsigned char *sha1,
2842 struct pack_entry *e,
2843 struct packed_git *p)
2844{
2845 off_t offset;
2846
2847 if (p->num_bad_objects) {
2848 unsigned i;
2849 for (i = 0; i < p->num_bad_objects; i++)
2850 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2851 return 0;
2852 }
2853
2854 offset = find_pack_entry_one(sha1, p);
2855 if (!offset)
2856 return 0;
2857
2858 /*
2859 * We are about to tell the caller where they can locate the
2860 * requested object. We better make sure the packfile is
2861 * still here and can be accessed before supplying that
2862 * answer, as it may have been deleted since the index was
2863 * loaded!
2864 */
319b678a 2865 if (!is_pack_valid(p))
95099731 2866 return 0;
95099731
NTND
2867 e->offset = offset;
2868 e->p = p;
2869 hashcpy(e->sha1, sha1);
2870 return 1;
2871}
2872
d40d535b
MH
2873/*
2874 * Iff a pack file contains the object named by sha1, return true and
2875 * store its location to e.
2876 */
4d6acb70 2877static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557 2878{
a73cdd21 2879 struct mru_entry *p;
43057304 2880
1f688557 2881 prepare_packed_git();
f7c22cc6
NP
2882 if (!packed_git)
2883 return 0;
1f688557 2884
a73cdd21
JK
2885 for (p = packed_git_mru->head; p; p = p->next) {
2886 if (fill_pack_entry(sha1, e, p->item)) {
2887 mru_mark(packed_git_mru, p);
1b1005d1
MH
2888 return 1;
2889 }
c01f51cc 2890 }
1f688557
JH
2891 return 0;
2892}
2893
a6080a0a 2894struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2895 struct packed_git *packs)
2896{
2897 struct packed_git *p;
bf592c50
DB
2898
2899 for (p = packs; p; p = p->next) {
43057304 2900 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2901 return p;
2902 }
2903 return NULL;
21666f1a 2904
bf592c50
DB
2905}
2906
052fe5ea 2907static int sha1_loose_object_info(const unsigned char *sha1,
46f03448
KN
2908 struct object_info *oi,
2909 int flags)
65c2e0c3 2910{
46f03448
KN
2911 int status = 0;
2912 unsigned long mapsize;
65c2e0c3 2913 void *map;
ef49a7a0 2914 git_zstream stream;
d65a16f6 2915 char hdr[32];
46f03448 2916 struct strbuf hdrbuf = STRBUF_INIT;
65c2e0c3 2917
5d642e75
JK
2918 if (oi->delta_base_sha1)
2919 hashclr(oi->delta_base_sha1);
2920
052fe5ea
JK
2921 /*
2922 * If we don't care about type or size, then we don't
4ef8d1dd
JH
2923 * need to look inside the object at all. Note that we
2924 * do not optimize out the stat call, even if the
2925 * caller doesn't care about the disk-size, since our
2926 * return value implicitly indicates whether the
2927 * object even exists.
052fe5ea 2928 */
46f03448 2929 if (!oi->typep && !oi->typename && !oi->sizep) {
771e7d57 2930 const char *path;
4ef8d1dd 2931 struct stat st;
771e7d57 2932 if (stat_sha1_file(sha1, &st, &path) < 0)
4ef8d1dd
JH
2933 return -1;
2934 if (oi->disk_sizep)
23c339c0 2935 *oi->disk_sizep = st.st_size;
052fe5ea
JK
2936 return 0;
2937 }
2938
bb6b8e4f 2939 map = map_sha1_file(sha1, &mapsize);
f0df4ed5 2940 if (!map)
dbea72a8 2941 return -1;
23c339c0
JK
2942 if (oi->disk_sizep)
2943 *oi->disk_sizep = mapsize;
19fc5e84 2944 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
46f03448
KN
2945 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2946 status = error("unable to unpack %s header with --allow-unknown-type",
2947 sha1_to_hex(sha1));
2948 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
36e4d74a
JH
2949 status = error("unable to unpack %s header",
2950 sha1_to_hex(sha1));
46f03448
KN
2951 if (status < 0)
2952 ; /* Do nothing */
2953 else if (hdrbuf.len) {
2954 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2955 status = error("unable to parse %s header with --allow-unknown-type",
2956 sha1_to_hex(sha1));
2957 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
36e4d74a 2958 status = error("unable to parse %s header", sha1_to_hex(sha1));
39c68542 2959 git_inflate_end(&stream);
65c2e0c3 2960 munmap(map, mapsize);
46f03448 2961 if (status && oi->typep)
23c339c0 2962 *oi->typep = status;
46f03448 2963 strbuf_release(&hdrbuf);
93cff9a9 2964 return (status < 0) ? status : 0;
65c2e0c3
JH
2965}
2966
de7b5d62 2967int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
f0df4ed5 2968{
c4d9986f 2969 struct cached_object *co;
f0df4ed5 2970 struct pack_entry e;
5b086407 2971 int rtype;
1f0c0d36
JT
2972 const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ?
2973 lookup_replace_object(sha1) :
2974 sha1;
f0df4ed5 2975
1f7117ef 2976 co = find_cached_object(real);
c4d9986f 2977 if (co) {
5b086407
JK
2978 if (oi->typep)
2979 *(oi->typep) = co->type;
9a490590
JH
2980 if (oi->sizep)
2981 *(oi->sizep) = co->size;
161f00e7
JK
2982 if (oi->disk_sizep)
2983 *(oi->disk_sizep) = 0;
5d642e75
JK
2984 if (oi->delta_base_sha1)
2985 hashclr(oi->delta_base_sha1);
46f03448
KN
2986 if (oi->typename)
2987 strbuf_addstr(oi->typename, typename(co->type));
9a490590 2988 oi->whence = OI_CACHED;
5b086407 2989 return 0;
c4d9986f
NTND
2990 }
2991
1f7117ef 2992 if (!find_pack_entry(real, &e)) {
ddd63e64 2993 /* Most likely it's a loose object. */
46f03448 2994 if (!sha1_loose_object_info(real, oi, flags)) {
9a490590 2995 oi->whence = OI_LOOSE;
5b086407 2996 return 0;
9a490590 2997 }
ddd63e64
SG
2998
2999 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 3000 reprepare_packed_git();
1f7117ef 3001 if (!find_pack_entry(real, &e))
052fe5ea 3002 return -1;
f0df4ed5 3003 }
3d77d877 3004
23c339c0 3005 rtype = packed_object_info(e.p, e.offset, oi);
412916ee 3006 if (rtype < 0) {
1f7117ef
CC
3007 mark_bad_packed_object(e.p, real);
3008 return sha1_object_info_extended(real, oi, 0);
5266d369
JH
3009 } else if (in_delta_base_cache(e.p, e.offset)) {
3010 oi->whence = OI_DBCACHED;
9a490590
JH
3011 } else {
3012 oi->whence = OI_PACKED;
3013 oi->u.packed.offset = e.offset;
3014 oi->u.packed.pack = e.p;
3015 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
3016 rtype == OBJ_OFS_DELTA);
3d77d877
NP
3017 }
3018
5b086407 3019 return 0;
f0df4ed5
JS
3020}
3021
3fc0dca9 3022/* returns enum object_type or negative */
9a490590
JH
3023int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
3024{
5b086407 3025 enum object_type type;
27b5c1a0 3026 struct object_info oi = OBJECT_INFO_INIT;
9a490590 3027
5b086407 3028 oi.typep = &type;
9a490590 3029 oi.sizep = sizep;
1f0c0d36
JT
3030 if (sha1_object_info_extended(sha1, &oi,
3031 OBJECT_INFO_LOOKUP_REPLACE) < 0)
5b086407
JK
3032 return -1;
3033 return type;
9a490590
JH
3034}
3035
21666f1a
NP
3036static void *read_packed_sha1(const unsigned char *sha1,
3037 enum object_type *type, unsigned long *size)
1f688557
JH
3038{
3039 struct pack_entry e;
8eca0b47 3040 void *data;
1f688557 3041
cd673c1f 3042 if (!find_pack_entry(sha1, &e))
1f688557 3043 return NULL;
85fe35ab 3044 data = cache_or_unpack_entry(e.p, e.offset, size, type);
8eca0b47
NP
3045 if (!data) {
3046 /*
3047 * We're probably in deep shit, but let's try to fetch
3048 * the required object anyway from another pack or loose.
3049 * This should happen only in the presence of a corrupted
3050 * pack, and is better than failing outright.
3051 */
3052 error("failed to read object %s at offset %"PRIuMAX" from %s",
3053 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
3054 mark_bad_packed_object(e.p, sha1);
ac939109 3055 data = read_object(sha1, type, size);
8eca0b47
NP
3056 }
3057 return data;
1f688557
JH
3058}
3059
21666f1a
NP
3060int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
3061 unsigned char *sha1)
d66b37bb
JH
3062{
3063 struct cached_object *co;
3064
21666f1a 3065 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
3066 if (has_sha1_file(sha1) || find_cached_object(sha1))
3067 return 0;
c7353967 3068 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
d66b37bb
JH
3069 co = &cached_objects[cached_object_nr++];
3070 co->size = len;
21666f1a 3071 co->type = type;
efa13f7b
JH
3072 co->buf = xmalloc(len);
3073 memcpy(co->buf, buf, len);
d66b37bb
JH
3074 hashcpy(co->sha1, sha1);
3075 return 0;
3076}
3077
c2c5b270
CC
3078static void *read_object(const unsigned char *sha1, enum object_type *type,
3079 unsigned long *size)
0fcfd160
LT
3080{
3081 unsigned long mapsize;
3082 void *map, *buf;
d66b37bb
JH
3083 struct cached_object *co;
3084
3085 co = find_cached_object(sha1);
3086 if (co) {
21666f1a 3087 *type = co->type;
d66b37bb 3088 *size = co->size;
182af834 3089 return xmemdupz(co->buf, co->size);
d66b37bb 3090 }
0fcfd160 3091
8276c007
PE
3092 buf = read_packed_sha1(sha1, type, size);
3093 if (buf)
3094 return buf;
bb6b8e4f 3095 map = map_sha1_file(sha1, &mapsize);
0fcfd160 3096 if (map) {
7efbff75 3097 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
3098 munmap(map, mapsize);
3099 return buf;
3100 }
637cdd9d 3101 reprepare_packed_git();
8276c007 3102 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
3103}
3104
b6c4cecc
JH
3105/*
3106 * This function dies on corrupt objects; the callers who want to
3107 * deal with them should arrange to call read_object() and give error
3108 * messages themselves.
3109 */
5bf29b95
JH
3110void *read_sha1_file_extended(const unsigned char *sha1,
3111 enum object_type *type,
3112 unsigned long *size,
1f0c0d36 3113 int lookup_replace)
ac939109 3114{
3ba7a065 3115 void *data;
b6c4cecc 3116 const struct packed_git *p;
771e7d57
JK
3117 const char *path;
3118 struct stat st;
1f0c0d36
JT
3119 const unsigned char *repl = lookup_replace ? lookup_replace_object(sha1)
3120 : sha1;
b6c4cecc 3121
3ba7a065
JH
3122 errno = 0;
3123 data = read_object(repl, type, size);
4bbf5a26 3124 if (data)
b6c4cecc 3125 return data;
68095570 3126
25f3af3f 3127 if (errno && errno != ENOENT)
3ba7a065
JH
3128 die_errno("failed to read object %s", sha1_to_hex(sha1));
3129
68095570 3130 /* die if we replaced an object with one that does not exist */
b6c4cecc 3131 if (repl != sha1)
68095570
CC
3132 die("replacement %s not found for %s",
3133 sha1_to_hex(repl), sha1_to_hex(sha1));
3134
771e7d57 3135 if (!stat_sha1_file(repl, &st, &path))
b6c4cecc
JH
3136 die("loose object %s (stored in %s) is corrupt",
3137 sha1_to_hex(repl), path);
68095570 3138
b6c4cecc
JH
3139 if ((p = has_packed_and_bad(repl)) != NULL)
3140 die("packed object %s (stored in %s) is corrupt",
3141 sha1_to_hex(repl), p->pack_name);
f5552aee 3142
b6c4cecc 3143 return NULL;
ac939109
NP
3144}
3145
40469ee9 3146void *read_object_with_reference(const unsigned char *sha1,
21666f1a 3147 const char *required_type_name,
40469ee9
JH
3148 unsigned long *size,
3149 unsigned char *actual_sha1_return)
f4913f91 3150{
21666f1a 3151 enum object_type type, required_type;
f4913f91
JH
3152 void *buffer;
3153 unsigned long isize;
40469ee9 3154 unsigned char actual_sha1[20];
f4913f91 3155
21666f1a 3156 required_type = type_from_string(required_type_name);
e702496e 3157 hashcpy(actual_sha1, sha1);
40469ee9
JH
3158 while (1) {
3159 int ref_length = -1;
3160 const char *ref_type = NULL;
f4913f91 3161
21666f1a 3162 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
3163 if (!buffer)
3164 return NULL;
21666f1a 3165 if (type == required_type) {
40469ee9
JH
3166 *size = isize;
3167 if (actual_sha1_return)
e702496e 3168 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
3169 return buffer;
3170 }
3171 /* Handle references */
21666f1a 3172 else if (type == OBJ_COMMIT)
40469ee9 3173 ref_type = "tree ";
21666f1a 3174 else if (type == OBJ_TAG)
40469ee9
JH
3175 ref_type = "object ";
3176 else {
3177 free(buffer);
3178 return NULL;
3179 }
3180 ref_length = strlen(ref_type);
f4913f91 3181
50974ec9
MK
3182 if (ref_length + 40 > isize ||
3183 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 3184 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
3185 free(buffer);
3186 return NULL;
3187 }
1cf58e72 3188 free(buffer);
40469ee9
JH
3189 /* Now we have the ID of the referred-to object in
3190 * actual_sha1. Check again. */
f4913f91 3191 }
f4913f91
JH
3192}
3193
ce9fbf16 3194static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 3195 const char *type, unsigned char *sha1,
d65a16f6 3196 char *hdr, int *hdrlen)
d410c0f5 3197{
9126f009 3198 git_SHA_CTX c;
d410c0f5
JH
3199
3200 /* Generate the header */
ef1286d3 3201 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
d410c0f5
JH
3202
3203 /* Sha1.. */
9126f009
NP
3204 git_SHA1_Init(&c);
3205 git_SHA1_Update(&c, hdr, *hdrlen);
3206 git_SHA1_Update(&c, buf, len);
3207 git_SHA1_Final(sha1, &c);
d410c0f5
JH
3208}
3209
230f1322 3210/*
5a688fe4 3211 * Move the just written object into its final resting place.
230f1322 3212 */
cb5add58 3213int finalize_object_file(const char *tmpfile, const char *filename)
230f1322 3214{
e32c0a9c 3215 int ret = 0;
5a688fe4 3216
348df166 3217 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
3218 goto try_rename;
3219 else if (link(tmpfile, filename))
e32c0a9c 3220 ret = errno;
7ebb6fca
LT
3221
3222 /*
3223 * Coda hack - coda doesn't like cross-directory links,
3224 * so we fall back to a rename, which will mean that it
3225 * won't be able to check collisions, but that's not a
3226 * big deal.
3227 *
3228 * The same holds for FAT formatted media.
3229 *
3be1f18e 3230 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
3231 * left to unlink.
3232 */
3233 if (ret && ret != EEXIST) {
be66a6c4 3234 try_rename:
7ebb6fca 3235 if (!rename(tmpfile, filename))
3be1f18e 3236 goto out;
9e48b389 3237 ret = errno;
230f1322 3238 }
691f1a28 3239 unlink_or_warn(tmpfile);
230f1322
LT
3240 if (ret) {
3241 if (ret != EEXIST) {
7616c6ca 3242 return error_errno("unable to write sha1 filename %s", filename);
230f1322
LT
3243 }
3244 /* FIXME!!! Collision check here ? */
3245 }
3246
3be1f18e 3247out:
5256b006 3248 if (adjust_shared_perm(filename))
5a688fe4 3249 return error("unable to set permission to '%s'", filename);
230f1322
LT
3250 return 0;
3251}
3252
4d548150
LT
3253static int write_buffer(int fd, const void *buf, size_t len)
3254{
d34cf19b 3255 if (write_in_full(fd, buf, len) < 0)
7616c6ca 3256 return error_errno("file write error");
4d548150
LT
3257 return 0;
3258}
3259
ce9fbf16 3260int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
3261 unsigned char *sha1)
3262{
d65a16f6 3263 char hdr[32];
ef1286d3 3264 int hdrlen = sizeof(hdr);
abdc3fc8
RS
3265 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3266 return 0;
3267}
3268
e9039dd3
LT
3269/* Finalize a file on disk, and close it. */
3270static void close_sha1_file(int fd)
3271{
aafe9fba
LT
3272 if (fsync_object_files)
3273 fsync_or_die(fd, "sha1 file");
e9039dd3 3274 if (close(fd) != 0)
d824cbba 3275 die_errno("error when closing sha1 file");
e9039dd3
LT
3276}
3277
5723fe7e
LT
3278/* Size of directory component, including the ending '/' */
3279static inline int directory_size(const char *filename)
3280{
3281 const char *s = strrchr(filename, '/');
3282 if (!s)
3283 return 0;
3284 return s - filename + 1;
3285}
3286
3287/*
3288 * This creates a temporary file in the same directory as the final
3289 * 'filename'
3290 *
3291 * We want to avoid cross-directory filename renames, because those
3292 * can have problems on various filesystems (FAT, NFS, Coda).
3293 */
d4b3d11a 3294static int create_tmpfile(struct strbuf *tmp, const char *filename)
5723fe7e
LT
3295{
3296 int fd, dirlen = directory_size(filename);
3297
d4b3d11a
JK
3298 strbuf_reset(tmp);
3299 strbuf_add(tmp, filename, dirlen);
3300 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3301 fd = git_mkstemp_mode(tmp->buf, 0444);
cbacbf4e 3302 if (fd < 0 && dirlen && errno == ENOENT) {
d4b3d11a
JK
3303 /*
3304 * Make sure the directory exists; note that the contents
3305 * of the buffer are undefined after mkstemp returns an
3306 * error, so we have to rewrite the whole buffer from
3307 * scratch.
3308 */
3309 strbuf_reset(tmp);
3310 strbuf_add(tmp, filename, dirlen - 1);
3311 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
b2476a60 3312 return -1;
d4b3d11a 3313 if (adjust_shared_perm(tmp->buf))
5723fe7e
LT
3314 return -1;
3315
3316 /* Try again */
d4b3d11a
JK
3317 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3318 fd = git_mkstemp_mode(tmp->buf, 0444);
5723fe7e
LT
3319 }
3320 return fd;
3321}
3322
bbac7311 3323static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 3324 const void *buf, unsigned long len, time_t mtime)
0fcfd160 3325{
915308b1 3326 int fd, ret;
9892beba 3327 unsigned char compressed[4096];
ef49a7a0 3328 git_zstream stream;
748af44c
NP
3329 git_SHA_CTX c;
3330 unsigned char parano_sha1[20];
d4b3d11a 3331 static struct strbuf tmp_file = STRBUF_INIT;
30d6c6ea 3332 const char *filename = sha1_file_name(sha1);
a44c9a5e 3333
d4b3d11a 3334 fd = create_tmpfile(&tmp_file, filename);
aac17941 3335 if (fd < 0) {
35243577 3336 if (errno == EACCES)
82247e9b 3337 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 3338 else
7616c6ca 3339 return error_errno("unable to create temporary file");
aac17941
LT
3340 }
3341
0fcfd160 3342 /* Set it up */
55bb5c91 3343 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 3344 stream.next_out = compressed;
9892beba 3345 stream.avail_out = sizeof(compressed);
748af44c 3346 git_SHA1_Init(&c);
a44c9a5e
LT
3347
3348 /* First header.. */
d65a16f6 3349 stream.next_in = (unsigned char *)hdr;
a44c9a5e 3350 stream.avail_in = hdrlen;
55bb5c91
JH
3351 while (git_deflate(&stream, 0) == Z_OK)
3352 ; /* nothing */
748af44c 3353 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
3354
3355 /* Then the data itself.. */
c00e657d 3356 stream.next_in = (void *)buf;
a44c9a5e 3357 stream.avail_in = len;
9892beba 3358 do {
748af44c 3359 unsigned char *in0 = stream.next_in;
55bb5c91 3360 ret = git_deflate(&stream, Z_FINISH);
748af44c 3361 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
3362 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3363 die("unable to write sha1 file");
3364 stream.next_out = compressed;
3365 stream.avail_out = sizeof(compressed);
3366 } while (ret == Z_OK);
3367
ac54c277
LT
3368 if (ret != Z_STREAM_END)
3369 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 3370 ret = git_deflate_end_gently(&stream);
ac54c277
LT
3371 if (ret != Z_OK)
3372 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
3373 git_SHA1_Final(parano_sha1, &c);
3374 if (hashcmp(sha1, parano_sha1) != 0)
3375 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 3376
e9039dd3 3377 close_sha1_file(fd);
0fcfd160 3378
bbac7311
NP
3379 if (mtime) {
3380 struct utimbuf utb;
3381 utb.actime = mtime;
3382 utb.modtime = mtime;
d4b3d11a 3383 if (utime(tmp_file.buf, &utb) < 0)
7616c6ca 3384 warning_errno("failed utime() on %s", tmp_file.buf);
bbac7311
NP
3385 }
3386
d4b3d11a 3387 return finalize_object_file(tmp_file.buf, filename);
0fcfd160 3388}
8237b185 3389
33d4221c
JK
3390static int freshen_loose_object(const unsigned char *sha1)
3391{
3392 return check_and_freshen(sha1, 1);
3393}
3394
3395static int freshen_packed_object(const unsigned char *sha1)
3396{
3397 struct pack_entry e;
ee1c6c34
JK
3398 if (!find_pack_entry(sha1, &e))
3399 return 0;
3400 if (e.p->freshened)
3401 return 1;
3402 if (!freshen_file(e.p->pack_name))
3403 return 0;
3404 e.p->freshened = 1;
3405 return 1;
33d4221c
JK
3406}
3407
1427a7ff 3408int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
bbac7311 3409{
bbac7311 3410 char hdr[32];
ef1286d3 3411 int hdrlen = sizeof(hdr);
bbac7311
NP
3412
3413 /* Normally if we have it in the pack then we do not bother writing
3414 * it out into .git/objects/??/?{38} file.
3415 */
3416 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
b5f52f37 3417 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
bbac7311
NP
3418 return 0;
3419 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3420}
3421
0c3db67c
ES
3422int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3423 unsigned char *sha1, unsigned flags)
3424{
3425 char *header;
3426 int hdrlen, status = 0;
3427
3428 /* type string, SP, %lu of the length plus NUL must fit this */
ef1286d3
JK
3429 hdrlen = strlen(type) + 32;
3430 header = xmalloc(hdrlen);
0c3db67c
ES
3431 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3432
3433 if (!(flags & HASH_WRITE_OBJECT))
3434 goto cleanup;
051086b9 3435 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
0c3db67c
ES
3436 goto cleanup;
3437 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3438
3439cleanup:
3440 free(header);
3441 return status;
3442}
3443
bbac7311
NP
3444int force_object_loose(const unsigned char *sha1, time_t mtime)
3445{
bbac7311
NP
3446 void *buf;
3447 unsigned long len;
3448 enum object_type type;
3449 char hdr[32];
3450 int hdrlen;
1fb23e65 3451 int ret;
bbac7311 3452
c529d75a 3453 if (has_loose_object(sha1))
bbac7311
NP
3454 return 0;
3455 buf = read_packed_sha1(sha1, &type, &len);
3456 if (!buf)
3457 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
ef1286d3 3458 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
1fb23e65
BS
3459 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3460 free(buf);
3461
3462 return ret;
bbac7311
NP
3463}
3464
bf592c50
DB
3465int has_pack_index(const unsigned char *sha1)
3466{
3467 struct stat st;
3468 if (stat(sha1_pack_index_name(sha1), &st))
3469 return 0;
3470 return 1;
bf592c50
DB
3471}
3472
cd673c1f
JH
3473int has_sha1_pack(const unsigned char *sha1)
3474{
3475 struct pack_entry e;
3476 return find_pack_entry(sha1, &e);
3477}
3478
0eeb077b 3479int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
8237b185 3480{
1f688557
JH
3481 struct pack_entry e;
3482
3e8b7d3c
JN
3483 if (!startup_info->have_repository)
3484 return 0;
cd673c1f 3485 if (find_pack_entry(sha1, &e))
1f688557 3486 return 1;
45e8a748
JK
3487 if (has_loose_object(sha1))
3488 return 1;
0eeb077b
JK
3489 if (flags & HAS_SHA1_QUICK)
3490 return 0;
45e8a748
JK
3491 reprepare_packed_git();
3492 return find_pack_entry(sha1, &e);
b419aa25 3493}
3494
3495int has_object_file(const struct object_id *oid)
3496{
3497 return has_sha1_file(oid->hash);
8237b185 3498}
74400e71 3499
5827a035
JK
3500int has_object_file_with_flags(const struct object_id *oid, int flags)
3501{
3502 return has_sha1_file_with_flags(oid->hash, flags);
3503}
3504
c879daa2
NTND
3505static void check_tree(const void *buf, size_t size)
3506{
3507 struct tree_desc desc;
3508 struct name_entry entry;
3509
3510 init_tree_desc(&desc, buf, size);
3511 while (tree_entry(&desc, &entry))
3512 /* do nothing
3513 * tree_entry() will die() on malformed entries */
3514 ;
3515}
3516
3517static void check_commit(const void *buf, size_t size)
3518{
3519 struct commit c;
3520 memset(&c, 0, sizeof(c));
3521 if (parse_commit_buffer(&c, buf, size))
3522 die("corrupt commit");
3523}
3524
3525static void check_tag(const void *buf, size_t size)
3526{
3527 struct tag t;
3528 memset(&t, 0, sizeof(t));
3529 if (parse_tag_buffer(&t, buf, size))
3530 die("corrupt tag");
3531}
3532
43df4f86 3533static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
3534 enum object_type type,
3535 const char *path, unsigned flags)
e7332f96 3536{
6c510bee 3537 int ret, re_allocated = 0;
c4ce46fc 3538 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 3539
7672db20 3540 if (!type)
edaec3fb 3541 type = OBJ_BLOB;
6c510bee
LT
3542
3543 /*
3544 * Convert blobs to git internal format
3545 */
43df4f86 3546 if ((type == OBJ_BLOB) && path) {
f285a2d7 3547 struct strbuf nbuf = STRBUF_INIT;
21e5ad50 3548 if (convert_to_git(path, buf, size, &nbuf,
5e12e78e 3549 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 3550 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
3551 re_allocated = 1;
3552 }
3553 }
c4ce46fc 3554 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
3555 if (type == OBJ_TREE)
3556 check_tree(buf, size);