pack: move static state variables
[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"
b2141fc1 10#include "config.h"
6eac50d8 11#include "string-list.h"
697cc8ef 12#include "lockfile.h"
1f688557 13#include "delta.h"
a733cb60 14#include "pack.h"
8e440259
PE
15#include "blob.h"
16#include "commit.h"
4dd1fbc7 17#include "run-command.h"
8e440259
PE
18#include "tag.h"
19#include "tree.h"
c879daa2 20#include "tree-walk.h"
f35a6d3b 21#include "refs.h"
70f5d5d3 22#include "pack-revindex.h"
628522ec 23#include "sha1-lookup.h"
568508e7 24#include "bulk-checkin.h"
090ea126 25#include "streaming.h"
543c5caa 26#include "dir.h"
a73cdd21 27#include "mru.h"
12d95ef6 28#include "list.h"
c4c6effa 29#include "mergesort.h"
cf3c6352 30#include "quote.h"
4f39cd82 31#include "packfile.h"
0fcfd160 32
28bd70d8
JN
33#define SZ_FMT PRIuMAX
34static inline uintmax_t sz_fmt(size_t s) { return s; }
e05db0fd 35
96f1e58f 36const unsigned char null_sha1[20];
3e56e724 37const struct object_id null_oid;
8576fde6
JK
38const struct object_id empty_tree_oid = {
39 EMPTY_TREE_SHA1_BIN_LITERAL
40};
41const struct object_id empty_blob_oid = {
42 EMPTY_BLOB_SHA1_BIN_LITERAL
43};
88cd621d 44
c597ba80
NTND
45/*
46 * This is meant to hold a *small* number of objects that you would
47 * want read_sha1_file() to be able to return, but yet you do not want
48 * to write them into the object store (e.g. a browse-only
49 * application).
50 */
51static struct cached_object {
52 unsigned char sha1[20];
53 enum object_type type;
54 void *buf;
55 unsigned long size;
56} *cached_objects;
57static int cached_object_nr, cached_object_alloc;
58
59static struct cached_object empty_tree = {
dab0d410 60 EMPTY_TREE_SHA1_BIN_LITERAL,
c597ba80
NTND
61 OBJ_TREE,
62 "",
63 0
64};
65
66static struct cached_object *find_cached_object(const unsigned char *sha1)
67{
68 int i;
69 struct cached_object *co = cached_objects;
70
71 for (i = 0; i < cached_object_nr; i++, co++) {
72 if (!hashcmp(co->sha1, sha1))
73 return co;
74 }
75 if (!hashcmp(sha1, empty_tree.sha1))
76 return &empty_tree;
77 return NULL;
78}
79
90a6464b
JH
80int mkdir_in_gitdir(const char *path)
81{
82 if (mkdir(path, 0777)) {
83 int saved_errno = errno;
84 struct stat st;
85 struct strbuf sb = STRBUF_INIT;
86
87 if (errno != EEXIST)
88 return -1;
89 /*
90 * Are we looking at a path in a symlinked worktree
91 * whose original repository does not yet have it?
92 * e.g. .git/rr-cache pointing at its original
93 * repository in which the user hasn't performed any
94 * conflict resolution yet?
95 */
96 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
97 strbuf_readlink(&sb, path, st.st_size) ||
98 !is_absolute_path(sb.buf) ||
99 mkdir(sb.buf, 0777)) {
100 strbuf_release(&sb);
101 errno = saved_errno;
102 return -1;
103 }
104 strbuf_release(&sb);
105 }
106 return adjust_shared_perm(path);
107}
108
0be0521b 109enum scld_error safe_create_leading_directories(char *path)
b2cb9425 110{
26c8ae2a 111 char *next_component = path + offset_1st_component(path);
0be0521b 112 enum scld_error ret = SCLD_OK;
67d42212 113
0be0521b 114 while (ret == SCLD_OK && next_component) {
f0502332 115 struct stat st;
0f527403 116 char *slash = next_component, slash_character;
f0502332 117
0f527403
MH
118 while (*slash && !is_dir_sep(*slash))
119 slash++;
120
121 if (!*slash)
b2cb9425 122 break;
bf10cf70 123
26c8ae2a 124 next_component = slash + 1;
0f527403 125 while (is_dir_sep(*next_component))
bf10cf70 126 next_component++;
26c8ae2a 127 if (!*next_component)
5f0bdf50 128 break;
831651fd 129
0f527403 130 slash_character = *slash;
831651fd 131 *slash = '\0';
67d42212
JR
132 if (!stat(path, &st)) {
133 /* path exists */
204a047f
MH
134 if (!S_ISDIR(st.st_mode)) {
135 errno = ENOTDIR;
0be0521b 136 ret = SCLD_EXISTS;
204a047f 137 }
53a39721 138 } else if (mkdir(path, 0777)) {
928734d9 139 if (errno == EEXIST &&
9e6f885d 140 !stat(path, &st) && S_ISDIR(st.st_mode))
928734d9 141 ; /* somebody created it since we checked */
18d37e86
MH
142 else if (errno == ENOENT)
143 /*
144 * Either mkdir() failed because
145 * somebody just pruned the containing
146 * directory, or stat() failed because
147 * the file that was in our way was
148 * just removed. Either way, inform
149 * the caller that it might be worth
150 * trying again:
151 */
152 ret = SCLD_VANISHED;
9e6f885d 153 else
0be0521b 154 ret = SCLD_FAILED;
53a39721 155 } else if (adjust_shared_perm(path)) {
0be0521b 156 ret = SCLD_PERMS;
457f06d6 157 }
0f527403 158 *slash = slash_character;
b2cb9425 159 }
9e6f885d 160 return ret;
b2cb9425 161}
723c31fe 162
0be0521b 163enum scld_error safe_create_leading_directories_const(const char *path)
8e21d63b 164{
02944307 165 int save_errno;
8e21d63b
JK
166 /* path points to cache entries, so xstrdup before messing with it */
167 char *buf = xstrdup(path);
0be0521b 168 enum scld_error result = safe_create_leading_directories(buf);
02944307
MH
169
170 save_errno = errno;
8e21d63b 171 free(buf);
02944307 172 errno = save_errno;
8e21d63b
JK
173 return result;
174}
175
177978f5
MH
176int raceproof_create_file(const char *path, create_file_fn fn, void *cb)
177{
178 /*
179 * The number of times we will try to remove empty directories
180 * in the way of path. This is only 1 because if another
181 * process is racily creating directories that conflict with
182 * us, we don't want to fight against them.
183 */
184 int remove_directories_remaining = 1;
185
186 /*
187 * The number of times that we will try to create the
188 * directories containing path. We are willing to attempt this
189 * more than once, because another process could be trying to
190 * clean up empty directories at the same time as we are
191 * trying to create them.
192 */
193 int create_directories_remaining = 3;
194
195 /* A scratch copy of path, filled lazily if we need it: */
196 struct strbuf path_copy = STRBUF_INIT;
197
198 int ret, save_errno;
199
200 /* Sanity check: */
201 assert(*path);
202
203retry_fn:
204 ret = fn(path, cb);
205 save_errno = errno;
206 if (!ret)
207 goto out;
208
209 if (errno == EISDIR && remove_directories_remaining-- > 0) {
210 /*
211 * A directory is in the way. Maybe it is empty; try
212 * to remove it:
213 */
214 if (!path_copy.len)
215 strbuf_addstr(&path_copy, path);
216
217 if (!remove_dir_recursively(&path_copy, REMOVE_DIR_EMPTY_ONLY))
218 goto retry_fn;
219 } else if (errno == ENOENT && create_directories_remaining-- > 0) {
220 /*
221 * Maybe the containing directory didn't exist, or
222 * maybe it was just deleted by a process that is
223 * racing with us to clean up empty directories. Try
224 * to create it:
225 */
226 enum scld_error scld_result;
227
228 if (!path_copy.len)
229 strbuf_addstr(&path_copy, path);
230
231 do {
232 scld_result = safe_create_leading_directories(path_copy.buf);
233 if (scld_result == SCLD_OK)
234 goto retry_fn;
235 } while (scld_result == SCLD_VANISHED && create_directories_remaining-- > 0);
236 }
237
238out:
239 strbuf_release(&path_copy);
240 errno = save_errno;
241 return ret;
242}
243
f7b7774f 244static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
ace1534d
JH
245{
246 int i;
247 for (i = 0; i < 20; i++) {
248 static char hex[] = "0123456789abcdef";
249 unsigned int val = sha1[i];
f7b7774f
JK
250 strbuf_addch(buf, hex[val >> 4]);
251 strbuf_addch(buf, hex[val & 0xf]);
afbba2f0 252 if (!i)
f7b7774f 253 strbuf_addch(buf, '/');
ace1534d
JH
254 }
255}
256
30d6c6ea 257const char *sha1_file_name(const unsigned char *sha1)
0fcfd160 258{
f7b7774f 259 static struct strbuf buf = STRBUF_INIT;
0fcfd160 260
f7b7774f
JK
261 strbuf_reset(&buf);
262 strbuf_addf(&buf, "%s/", get_object_directory());
560fb6a1 263
f7b7774f
JK
264 fill_sha1_path(&buf, sha1);
265 return buf.buf;
0fcfd160
LT
266}
267
38dbe5f0
JK
268struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
269{
270 strbuf_setlen(&alt->scratch, alt->base_len);
271 return &alt->scratch;
272}
273
29ec6af2
JK
274static const char *alt_sha1_path(struct alternate_object_database *alt,
275 const unsigned char *sha1)
276{
38dbe5f0 277 struct strbuf *buf = alt_scratch_buf(alt);
f7b7774f 278 fill_sha1_path(buf, sha1);
38dbe5f0 279 return buf->buf;
0fcfd160
LT
280}
281
d5a63b99
JH
282struct alternate_object_database *alt_odb_list;
283static struct alternate_object_database **alt_odb_tail;
ace1534d 284
4ea82473
JK
285/*
286 * Return non-zero iff the path is usable as an alternate object database.
287 */
288static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
289{
290 struct alternate_object_database *alt;
291
292 /* Detect cases where alternate disappeared */
293 if (!is_directory(path->buf)) {
294 error("object directory %s does not exist; "
295 "check .git/objects/info/alternates.",
296 path->buf);
297 return 0;
298 }
299
300 /*
301 * Prevent the common mistake of listing the same
302 * thing twice, or object directory itself.
303 */
304 for (alt = alt_odb_list; alt; alt = alt->next) {
ea0fc3b4 305 if (!fspathcmp(path->buf, alt->path))
4ea82473
JK
306 return 0;
307 }
308 if (!fspathcmp(path->buf, normalized_objdir))
309 return 0;
310
311 return 1;
312}
313
ddd5d056
JH
314/*
315 * Prepare alternate object database registry.
d5a63b99
JH
316 *
317 * The variable alt_odb_list points at the list of struct
318 * alternate_object_database. The elements on this list come from
319 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
320 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
321 * whose contents is similar to that environment variable but can be
322 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
323 * contains "/the/directory/corresponding/to/.git/objects/...", while
324 * its name points just after the slash at the end of ".git/objects/"
325 * in the example above, and has enough space to hold 40-byte hex
326 * SHA1, an extra slash for the first level indirection, and the
327 * terminating NUL.
ddd5d056 328 */
2456990d 329static void read_info_alternates(const char * relative_base, int depth);
539e7506
EK
330static int link_alt_odb_entry(const char *entry, const char *relative_base,
331 int depth, const char *normalized_objdir)
ace1534d 332{
c2f493a4 333 struct alternate_object_database *ent;
5bdf0a84 334 struct strbuf pathbuf = STRBUF_INIT;
d5a63b99 335
85dadc38 336 if (!is_absolute_path(entry) && relative_base) {
4ac9006f 337 strbuf_realpath(&pathbuf, relative_base, 1);
5bdf0a84 338 strbuf_addch(&pathbuf, '/');
c2f493a4 339 }
6eac50d8 340 strbuf_addstr(&pathbuf, entry);
c2f493a4 341
37a95862 342 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
670c359d
JK
343 error("unable to normalize alternate object path: %s",
344 pathbuf.buf);
345 strbuf_release(&pathbuf);
346 return -1;
347 }
5bdf0a84
HW
348
349 /*
350 * The trailing slash after the directory name is given by
351 * this function at the end. Remove duplicates.
352 */
4ea82473
JK
353 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
354 strbuf_setlen(&pathbuf, pathbuf.len - 1);
5bdf0a84 355
4ea82473
JK
356 if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
357 strbuf_release(&pathbuf);
c2f493a4
MW
358 return -1;
359 }
360
7f0fa2c0 361 ent = alloc_alt_odb(pathbuf.buf);
c2f493a4
MW
362
363 /* add the alternate entry */
364 *alt_odb_tail = ent;
365 alt_odb_tail = &(ent->next);
366 ent->next = NULL;
367
368 /* recursively add alternates */
4ea82473 369 read_info_alternates(pathbuf.buf, depth + 1);
c2f493a4 370
4ea82473 371 strbuf_release(&pathbuf);
c2f493a4
MW
372 return 0;
373}
374
cf3c6352
JK
375static const char *parse_alt_odb_entry(const char *string,
376 int sep,
377 struct strbuf *out)
378{
379 const char *end;
380
381 strbuf_reset(out);
382
383 if (*string == '#') {
384 /* comment; consume up to next separator */
385 end = strchrnul(string, sep);
386 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
387 /*
388 * quoted path; unquote_c_style has copied the
389 * data for us and set "end". Broken quoting (e.g.,
390 * an entry that doesn't end with a quote) falls
391 * back to the unquoted case below.
392 */
393 } else {
394 /* normal, unquoted path */
395 end = strchrnul(string, sep);
396 strbuf_add(out, string, end - string);
397 }
398
399 if (*end)
400 end++;
401 return end;
402}
403
c5950164 404static void link_alt_odb_entries(const char *alt, int len, int sep,
c2f493a4
MW
405 const char *relative_base, int depth)
406{
539e7506 407 struct strbuf objdirbuf = STRBUF_INIT;
cf3c6352 408 struct strbuf entry = STRBUF_INIT;
c2f493a4
MW
409
410 if (depth > 5) {
411 error("%s: ignoring alternate object stores, nesting too deep.",
412 relative_base);
413 return;
414 }
415
f655651e 416 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
670c359d
JK
417 if (strbuf_normalize_path(&objdirbuf) < 0)
418 die("unable to normalize object directory: %s",
419 objdirbuf.buf);
539e7506 420
cf3c6352
JK
421 while (*alt) {
422 alt = parse_alt_odb_entry(alt, sep, &entry);
423 if (!entry.len)
9577e7e3 424 continue;
cf3c6352 425 link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
9577e7e3 426 }
cf3c6352 427 strbuf_release(&entry);
539e7506 428 strbuf_release(&objdirbuf);
d5a63b99
JH
429}
430
2456990d 431static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 432{
9577e7e3 433 char *map;
dc49cd76 434 size_t mapsz;
d5a63b99 435 struct stat st;
5015f01c 436 char *path;
c2f493a4 437 int fd;
d5a63b99 438
5015f01c 439 path = xstrfmt("%s/info/alternates", relative_base);
a5436b57 440 fd = git_open(path);
5015f01c 441 free(path);
d5a63b99
JH
442 if (fd < 0)
443 return;
444 if (fstat(fd, &st) || (st.st_size == 0)) {
445 close(fd);
9a217f2a 446 return;
ace1534d 447 }
dc49cd76
SP
448 mapsz = xsize_t(st.st_size);
449 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 450 close(fd);
d5a63b99 451
c5950164 452 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
c2f493a4 453
dc49cd76 454 munmap(map, mapsz);
ace1534d
JH
455}
456
7f0fa2c0
JK
457struct alternate_object_database *alloc_alt_odb(const char *dir)
458{
459 struct alternate_object_database *ent;
7f0fa2c0 460
597f9134 461 FLEX_ALLOC_STR(ent, path, dir);
38dbe5f0
JK
462 strbuf_init(&ent->scratch, 0);
463 strbuf_addf(&ent->scratch, "%s/", dir);
464 ent->base_len = ent->scratch.len;
7f0fa2c0
JK
465
466 return ent;
467}
468
bef70b22
DB
469void add_to_alternates_file(const char *reference)
470{
471 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
77b9b1d1
JK
472 char *alts = git_pathdup("objects/info/alternates");
473 FILE *in, *out;
474
475 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
476 out = fdopen_lock_file(lock, "w");
477 if (!out)
478 die_errno("unable to fdopen alternates lockfile");
479
480 in = fopen(alts, "r");
481 if (in) {
482 struct strbuf line = STRBUF_INIT;
483 int found = 0;
484
3f163962 485 while (strbuf_getline(&line, in) != EOF) {
77b9b1d1
JK
486 if (!strcmp(reference, line.buf)) {
487 found = 1;
488 break;
489 }
490 fprintf_or_die(out, "%s\n", line.buf);
491 }
492
493 strbuf_release(&line);
494 fclose(in);
495
496 if (found) {
497 rollback_lock_file(lock);
498 lock = NULL;
499 }
500 }
501 else if (errno != ENOENT)
502 die_errno("unable to read alternates file");
503
504 if (lock) {
505 fprintf_or_die(out, "%s\n", reference);
506 if (commit_lock_file(lock))
507 die_errno("unable to move new alternates file into place");
508 if (alt_odb_tail)
509 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
510 }
511 free(alts);
bef70b22
DB
512}
513
a5b34d21
JK
514void add_to_alternates_memory(const char *reference)
515{
516 /*
517 * Make sure alternates are initialized, or else our entry may be
518 * overwritten when they are.
519 */
520 prepare_alt_odb();
521
522 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
523}
524
9eeea7d2
SB
525/*
526 * Compute the exact path an alternate is at and returns it. In case of
527 * error NULL is returned and the human readable error is added to `err`
528 * `path` may be relative and should point to $GITDIR.
529 * `err` must not be null.
530 */
531char *compute_alternate_path(const char *path, struct strbuf *err)
532{
533 char *ref_git = NULL;
534 const char *repo, *ref_git_s;
535 int seen_error = 0;
536
537 ref_git_s = real_path_if_valid(path);
538 if (!ref_git_s) {
539 seen_error = 1;
540 strbuf_addf(err, _("path '%s' does not exist"), path);
541 goto out;
542 } else
543 /*
544 * Beware: read_gitfile(), real_path() and mkpath()
545 * return static buffer
546 */
547 ref_git = xstrdup(ref_git_s);
548
549 repo = read_gitfile(ref_git);
550 if (!repo)
551 repo = read_gitfile(mkpath("%s/.git", ref_git));
552 if (repo) {
553 free(ref_git);
554 ref_git = xstrdup(repo);
555 }
556
557 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
558 char *ref_git_git = mkpathdup("%s/.git", ref_git);
559 free(ref_git);
560 ref_git = ref_git_git;
561 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
562 struct strbuf sb = STRBUF_INIT;
563 seen_error = 1;
564 if (get_common_dir(&sb, ref_git)) {
565 strbuf_addf(err,
566 _("reference repository '%s' as a linked "
567 "checkout is not supported yet."),
568 path);
569 goto out;
570 }
571
572 strbuf_addf(err, _("reference repository '%s' is not a "
573 "local repository."), path);
574 goto out;
575 }
576
577 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
578 strbuf_addf(err, _("reference repository '%s' is shallow"),
579 path);
580 seen_error = 1;
581 goto out;
582 }
583
584 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
585 strbuf_addf(err,
586 _("reference repository '%s' is grafted"),
587 path);
588 seen_error = 1;
589 goto out;
590 }
591
592out:
593 if (seen_error) {
6a83d902 594 FREE_AND_NULL(ref_git);
9eeea7d2
SB
595 }
596
597 return ref_git;
598}
599
fe1b2268 600int foreach_alt_odb(alt_odb_fn fn, void *cb)
d79796bc
JH
601{
602 struct alternate_object_database *ent;
fe1b2268 603 int r = 0;
d79796bc
JH
604
605 prepare_alt_odb();
fe1b2268
JK
606 for (ent = alt_odb_list; ent; ent = ent->next) {
607 r = fn(ent, cb);
608 if (r)
609 break;
610 }
611 return r;
d79796bc
JH
612}
613
c2f493a4
MW
614void prepare_alt_odb(void)
615{
554fe20d 616 const char *alt;
c2f493a4 617
7dc24aa5
SP
618 if (alt_odb_tail)
619 return;
620
c2f493a4
MW
621 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
622 if (!alt) alt = "";
623
c2f493a4 624 alt_odb_tail = &alt_odb_list;
c5950164 625 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
626
627 read_info_alternates(get_object_directory(), 0);
628}
629
3096b2ec 630/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
33d4221c 631static int freshen_file(const char *fn)
ace1534d 632{
33d4221c
JK
633 struct utimbuf t;
634 t.actime = t.modtime = time(NULL);
635 return !utime(fn, &t);
0f4dc14a 636}
ace1534d 637
3096b2ec
JK
638/*
639 * All of the check_and_freshen functions return 1 if the file exists and was
640 * freshened (if freshening was requested), 0 otherwise. If they return
641 * 0, you should not assume that it is safe to skip a write of the object (it
642 * either does not exist on disk, or has a stale mtime and may be subject to
643 * pruning).
644 */
6a5e6f5e 645int check_and_freshen_file(const char *fn, int freshen)
33d4221c
JK
646{
647 if (access(fn, F_OK))
648 return 0;
3096b2ec 649 if (freshen && !freshen_file(fn))
33d4221c
JK
650 return 0;
651 return 1;
652}
653
654static int check_and_freshen_local(const unsigned char *sha1, int freshen)
655{
656 return check_and_freshen_file(sha1_file_name(sha1), freshen);
657}
658
659static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
0f4dc14a
BC
660{
661 struct alternate_object_database *alt;
9a217f2a 662 prepare_alt_odb();
d5a63b99 663 for (alt = alt_odb_list; alt; alt = alt->next) {
29ec6af2
JK
664 const char *path = alt_sha1_path(alt, sha1);
665 if (check_and_freshen_file(path, freshen))
c529d75a 666 return 1;
ace1534d 667 }
c529d75a 668 return 0;
ace1534d
JH
669}
670
33d4221c
JK
671static int check_and_freshen(const unsigned char *sha1, int freshen)
672{
673 return check_and_freshen_local(sha1, freshen) ||
674 check_and_freshen_nonlocal(sha1, freshen);
675}
676
677int has_loose_object_nonlocal(const unsigned char *sha1)
678{
679 return check_and_freshen_nonlocal(sha1, 0);
680}
681
0f4dc14a
BC
682static int has_loose_object(const unsigned char *sha1)
683{
33d4221c 684 return check_and_freshen(sha1, 0);
0f4dc14a
BC
685}
686
b79d18c9 687void pack_report(void)
a53128b6
SP
688{
689 fprintf(stderr,
e05db0fd
PR
690 "pack_report: getpagesize() = %10" SZ_FMT "\n"
691 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
692 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
693 sz_fmt(getpagesize()),
694 sz_fmt(packed_git_window_size),
695 sz_fmt(packed_git_limit));
a53128b6
SP
696 fprintf(stderr,
697 "pack_report: pack_used_ctr = %10u\n"
698 "pack_report: pack_mmap_calls = %10u\n"
699 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
700 "pack_report: pack_mapped = "
701 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
702 pack_used_ctr,
703 pack_mmap_calls,
704 pack_open_windows, peak_pack_open_windows,
9e42d6a1 705 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
706}
707
d40d535b
MH
708/*
709 * Open and mmap the index file at path, perform a couple of
710 * consistency checks, then record its information to p. Return 0 on
711 * success.
712 */
713static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
714{
715 void *idx_map;
42873078 716 struct pack_idx_header *hdr;
dc49cd76 717 size_t idx_size;
74e34e1f 718 uint32_t version, nr, i, *index;
a5436b57 719 int fd = git_open(path);
1f688557 720 struct stat st;
42873078 721
1f688557
JH
722 if (fd < 0)
723 return -1;
724 if (fstat(fd, &st)) {
725 close(fd);
726 return -1;
727 }
dc49cd76 728 idx_size = xsize_t(st.st_size);
2d88451b
SP
729 if (idx_size < 4 * 256 + 20 + 20) {
730 close(fd);
731 return error("index file %s is too small", path);
732 }
c4712e45 733 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 734 close(fd);
1f688557 735
42873078
NP
736 hdr = idx_map;
737 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
738 version = ntohl(hdr->idx_version);
739 if (version < 2 || version > 2) {
740 munmap(idx_map, idx_size);
6e1c2344 741 return error("index file %s is version %"PRIu32
74e34e1f
NP
742 " and is not supported by this binary"
743 " (try upgrading GIT to a newer version)",
744 path, version);
745 }
746 } else
747 version = 1;
df1b059d 748
1f688557 749 nr = 0;
42873078 750 index = idx_map;
74e34e1f
NP
751 if (version > 1)
752 index += 2; /* skip index header */
1f688557 753 for (i = 0; i < 256; i++) {
326bf396 754 uint32_t n = ntohl(index[i]);
2d88451b
SP
755 if (n < nr) {
756 munmap(idx_map, idx_size);
df1b059d 757 return error("non-monotonic index %s", path);
2d88451b 758 }
1f688557
JH
759 nr = n;
760 }
761
74e34e1f
NP
762 if (version == 1) {
763 /*
764 * Total size:
765 * - 256 index entries 4 bytes each
766 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
767 * - 20-byte SHA1 of the packfile
768 * - 20-byte SHA1 file checksum
769 */
770 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
771 munmap(idx_map, idx_size);
eef427a0 772 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
773 }
774 } else if (version == 2) {
775 /*
776 * Minimum size:
777 * - 8 bytes of header
778 * - 256 index entries 4 bytes each
779 * - 20-byte sha1 entry * nr
780 * - 4-byte crc entry * nr
781 * - 4-byte offset entry * nr
782 * - 20-byte SHA1 of the packfile
783 * - 20-byte SHA1 file checksum
784 * And after the 4-byte offset table might be a
785 * variable sized table containing 8-byte entries
786 * for offsets larger than 2^31.
787 */
788 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
789 unsigned long max_size = min_size;
790 if (nr)
791 max_size += (nr - 1)*8;
792 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 793 munmap(idx_map, idx_size);
eef427a0 794 return error("wrong index v2 file size in %s", path);
74e34e1f 795 }
7109c889
JH
796 if (idx_size != min_size &&
797 /*
798 * make sure we can deal with large pack offsets.
799 * 31-bit signed offset won't be enough, neither
800 * 32-bit unsigned one will be.
801 */
802 (sizeof(off_t) <= 4)) {
803 munmap(idx_map, idx_size);
804 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 805 }
2d88451b 806 }
1f688557 807
74e34e1f 808 p->index_version = version;
42873078
NP
809 p->index_data = idx_map;
810 p->index_size = idx_size;
57059091 811 p->num_objects = nr;
1f688557
JH
812 return 0;
813}
814
bc8e478a 815int open_pack_index(struct packed_git *p)
d079837e
SP
816{
817 char *idx_name;
9ae97018 818 size_t len;
d079837e
SP
819 int ret;
820
821 if (p->index_data)
822 return 0;
823
9ae97018
JK
824 if (!strip_suffix(p->pack_name, ".pack", &len))
825 die("BUG: pack_name does not end in .pack");
826 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
d079837e
SP
827 ret = check_packed_git_idx(idx_name, p);
828 free(idx_name);
829 return ret;
830}
831
11daf39b
SP
832static void scan_windows(struct packed_git *p,
833 struct packed_git **lru_p,
834 struct pack_window **lru_w,
835 struct pack_window **lru_l)
1f688557 836{
11daf39b
SP
837 struct pack_window *w, *w_l;
838
839 for (w_l = NULL, w = p->windows; w; w = w->next) {
840 if (!w->inuse_cnt) {
841 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
842 *lru_p = p;
843 *lru_w = w;
844 *lru_l = w_l;
54044bf8 845 }
54044bf8 846 }
11daf39b 847 w_l = w;
f9253394 848 }
11daf39b
SP
849}
850
7c3ecb32 851static int unuse_one_window(struct packed_git *current)
11daf39b
SP
852{
853 struct packed_git *p, *lru_p = NULL;
854 struct pack_window *lru_w = NULL, *lru_l = NULL;
855
856 if (current)
857 scan_windows(current, &lru_p, &lru_w, &lru_l);
858 for (p = packed_git; p; p = p->next)
859 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
860 if (lru_p) {
861 munmap(lru_w->base, lru_w->len);
862 pack_mapped -= lru_w->len;
863 if (lru_l)
864 lru_l->next = lru_w->next;
7c3ecb32 865 else
54044bf8 866 lru_p->windows = lru_w->next;
54044bf8 867 free(lru_w);
a53128b6 868 pack_open_windows--;
54044bf8
SP
869 return 1;
870 }
871 return 0;
f9253394
JH
872}
873
7c3ecb32 874void release_pack_memory(size_t need)
97bfeb34
SP
875{
876 size_t cur = pack_mapped;
7c3ecb32 877 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
97bfeb34
SP
878 ; /* nothing */
879}
880
02710228
SP
881static void mmap_limit_check(size_t length)
882{
883 static size_t limit = 0;
884 if (!limit) {
885 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
886 if (!limit)
887 limit = SIZE_MAX;
888 }
889 if (length > limit)
890 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
891 (uintmax_t)length, (uintmax_t)limit);
892}
893
1570856b
JK
894void *xmmap_gently(void *start, size_t length,
895 int prot, int flags, int fd, off_t offset)
58ecbd5e 896{
02710228
SP
897 void *ret;
898
899 mmap_limit_check(length);
900 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
901 if (ret == MAP_FAILED) {
902 if (!length)
903 return NULL;
7c3ecb32 904 release_pack_memory(length);
58ecbd5e 905 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
906 }
907 return ret;
908}
909
1570856b
JK
910void *xmmap(void *start, size_t length,
911 int prot, int flags, int fd, off_t offset)
912{
913 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
914 if (ret == MAP_FAILED)
9ca0aaf6 915 die_errno("mmap failed");
1570856b
JK
916 return ret;
917}
918
c9ced051
SP
919void close_pack_windows(struct packed_git *p)
920{
921 while (p->windows) {
922 struct pack_window *w = p->windows;
923
924 if (w->inuse_cnt)
925 die("pack '%s' still has open windows to it",
926 p->pack_name);
927 munmap(w->base, w->len);
928 pack_mapped -= w->len;
929 pack_open_windows--;
930 p->windows = w->next;
931 free(w);
932 }
933}
934
71fe5d7f
JS
935static int close_pack_fd(struct packed_git *p)
936{
937 if (p->pack_fd < 0)
938 return 0;
939
940 close(p->pack_fd);
941 pack_open_fds--;
942 p->pack_fd = -1;
943
944 return 1;
945}
946
38849a81
JS
947static void close_pack(struct packed_git *p)
948{
949 close_pack_windows(p);
950 close_pack_fd(p);
951 close_pack_index(p);
952}
953
954void close_all_packs(void)
955{
956 struct packed_git *p;
957
958 for (p = packed_git; p; p = p->next)
959 if (p->do_not_close)
ef1177d1 960 die("BUG: want to close pack marked 'do-not-close'");
38849a81
JS
961 else
962 close_pack(p);
963}
964
965
88d0db55
BC
966/*
967 * The LRU pack is the one with the oldest MRU window, preferring packs
968 * with no used windows, or the oldest mtime if it has no windows allocated.
969 */
970static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
971{
972 struct pack_window *w, *this_mru_w;
973 int has_windows_inuse = 0;
974
975 /*
976 * Reject this pack if it has windows and the previously selected
977 * one does not. If this pack does not have windows, reject
978 * it if the pack file is newer than the previously selected one.
979 */
980 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
981 return;
982
983 for (w = this_mru_w = p->windows; w; w = w->next) {
984 /*
985 * Reject this pack if any of its windows are in use,
986 * but the previously selected pack did not have any
987 * inuse windows. Otherwise, record that this pack
988 * has windows in use.
989 */
990 if (w->inuse_cnt) {
991 if (*accept_windows_inuse)
992 has_windows_inuse = 1;
993 else
994 return;
995 }
996
997 if (w->last_used > this_mru_w->last_used)
998 this_mru_w = w;
999
1000 /*
1001 * Reject this pack if it has windows that have been
1002 * used more recently than the previously selected pack.
1003 * If the previously selected pack had windows inuse and
1004 * we have not encountered a window in this pack that is
1005 * inuse, skip this check since we prefer a pack with no
1006 * inuse windows to one that has inuse windows.
1007 */
1008 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
1009 this_mru_w->last_used > (*mru_w)->last_used)
1010 return;
1011 }
1012
1013 /*
1014 * Select this pack.
1015 */
1016 *mru_w = this_mru_w;
1017 *lru_p = p;
1018 *accept_windows_inuse = has_windows_inuse;
1019}
1020
1021static int close_one_pack(void)
1022{
1023 struct packed_git *p, *lru_p = NULL;
1024 struct pack_window *mru_w = NULL;
1025 int accept_windows_inuse = 1;
1026
1027 for (p = packed_git; p; p = p->next) {
1028 if (p->pack_fd == -1)
1029 continue;
1030 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
1031 }
1032
71fe5d7f
JS
1033 if (lru_p)
1034 return close_pack_fd(lru_p);
88d0db55
BC
1035
1036 return 0;
1037}
1038
03e79c88 1039void unuse_pack(struct pack_window **w_cursor)
f9253394 1040{
03e79c88
SP
1041 struct pack_window *w = *w_cursor;
1042 if (w) {
1043 w->inuse_cnt--;
1044 *w_cursor = NULL;
1045 }
1f688557
JH
1046}
1047
fa5fc15d
SP
1048void close_pack_index(struct packed_git *p)
1049{
1050 if (p->index_data) {
1051 munmap((void *)p->index_data, p->index_size);
1052 p->index_data = NULL;
1053 }
1054}
1055
a0788266
JS
1056static unsigned int get_max_fd_limit(void)
1057{
1058#ifdef RLIMIT_NOFILE
491a8dec
JH
1059 {
1060 struct rlimit lim;
a0788266 1061
491a8dec
JH
1062 if (!getrlimit(RLIMIT_NOFILE, &lim))
1063 return lim.rlim_cur;
1064 }
1065#endif
1066
1067#ifdef _SC_OPEN_MAX
1068 {
1069 long open_max = sysconf(_SC_OPEN_MAX);
1070 if (0 < open_max)
1071 return open_max;
1072 /*
1073 * Otherwise, we got -1 for one of the two
1074 * reasons:
1075 *
1076 * (1) sysconf() did not understand _SC_OPEN_MAX
1077 * and signaled an error with -1; or
1078 * (2) sysconf() said there is no limit.
1079 *
1080 * We _could_ clear errno before calling sysconf() to
1081 * tell these two cases apart and return a huge number
1082 * in the latter case to let the caller cap it to a
1083 * value that is not so selfish, but letting the
1084 * fallback OPEN_MAX codepath take care of these cases
1085 * is a lot simpler.
1086 */
1087 }
1088#endif
a0788266 1089
491a8dec 1090#ifdef OPEN_MAX
a0788266
JS
1091 return OPEN_MAX;
1092#else
1093 return 1; /* see the caller ;-) */
1094#endif
1095}
1096
3cf8b462
SP
1097/*
1098 * Do not call this directly as this leaks p->pack_fd on error return;
1099 * call open_packed_git() instead.
1100 */
1101static int open_packed_git_1(struct packed_git *p)
1f688557 1102{
9bc879c1
SP
1103 struct stat st;
1104 struct pack_header hdr;
1105 unsigned char sha1[20];
1106 unsigned char *idx_sha1;
2c039da8 1107 long fd_flag;
9bc879c1 1108
d079837e
SP
1109 if (!p->index_data && open_pack_index(p))
1110 return error("packfile %s index unavailable", p->pack_name);
1111
c7934306 1112 if (!pack_max_fds) {
a0788266 1113 unsigned int max_fds = get_max_fd_limit();
c7934306
SP
1114
1115 /* Save 3 for stdin/stdout/stderr, 22 for work */
1116 if (25 < max_fds)
1117 pack_max_fds = max_fds - 25;
1118 else
1119 pack_max_fds = 1;
1120 }
1121
88d0db55 1122 while (pack_max_fds <= pack_open_fds && close_one_pack())
c7934306
SP
1123 ; /* nothing */
1124
a5436b57 1125 p->pack_fd = git_open(p->pack_name);
9bc879c1 1126 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 1127 return -1;
c7934306 1128 pack_open_fds++;
9bc879c1
SP
1129
1130 /* If we created the struct before we had the pack we lack size. */
bf592c50 1131 if (!p->pack_size) {
bf592c50 1132 if (!S_ISREG(st.st_mode))
072db278 1133 return error("packfile %s not a regular file", p->pack_name);
bf592c50 1134 p->pack_size = st.st_size;
9bc879c1 1135 } else if (p->pack_size != st.st_size)
072db278 1136 return error("packfile %s size changed", p->pack_name);
9bc879c1 1137
2c039da8
JH
1138 /* We leave these file descriptors open with sliding mmap;
1139 * there is no point keeping them open across exec(), though.
1140 */
1141 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
1142 if (fd_flag < 0)
072db278 1143 return error("cannot determine file descriptor flags");
2c039da8
JH
1144 fd_flag |= FD_CLOEXEC;
1145 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 1146 return error("cannot set FD_CLOEXEC");
2c039da8 1147
9bc879c1 1148 /* Verify we recognize this pack file format. */
e6e2bd62 1149 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 1150 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 1151 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 1152 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 1153 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
1154 return error("packfile %s is version %"PRIu32" and not"
1155 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
1156 p->pack_name, ntohl(hdr.hdr_version));
1157
1158 /* Verify the pack matches its index. */
57059091 1159 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
1160 return error("packfile %s claims to have %"PRIu32" objects"
1161 " while index indicates %"PRIu32" objects",
57059091
NP
1162 p->pack_name, ntohl(hdr.hdr_entries),
1163 p->num_objects);
9bc879c1 1164 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 1165 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 1166 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 1167 return error("packfile %s signature is unavailable", p->pack_name);
42873078 1168 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 1169 if (hashcmp(sha1, idx_sha1))
072db278
SP
1170 return error("packfile %s does not match index", p->pack_name);
1171 return 0;
9bc879c1
SP
1172}
1173
3cf8b462
SP
1174static int open_packed_git(struct packed_git *p)
1175{
1176 if (!open_packed_git_1(p))
1177 return 0;
71fe5d7f 1178 close_pack_fd(p);
3cf8b462
SP
1179 return -1;
1180}
1181
c4001d92 1182static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
1183{
1184 /* We must promise at least 20 bytes (one hash) after the
1185 * offset is available from this window, otherwise the offset
1186 * is not actually in this window and a different window (which
1187 * has that one hash excess) must be used. This is to support
1188 * the object header and delta base parsing routines below.
1189 */
1190 off_t win_off = win->offset;
1191 return win_off <= offset
1192 && (offset + 20) <= (win_off + win->len);
1193}
1194
4b25d091 1195unsigned char *use_pack(struct packed_git *p,
03e79c88 1196 struct pack_window **w_cursor,
c4001d92 1197 off_t offset,
ef49a7a0 1198 unsigned long *left)
9bc879c1 1199{
60bb8b14 1200 struct pack_window *win = *w_cursor;
03e79c88 1201
a9d98a14 1202 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
1203 * pointless to ask for an offset into the middle of that
1204 * hash, and the in_window function above wouldn't match
1205 * don't allow an offset too close to the end of the file.
1206 */
d131b7af
SP
1207 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1208 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
1209 if (offset > (p->pack_size - 20))
1210 die("offset beyond end of packfile (truncated pack?)");
13e0b0d3 1211 if (offset < 0)
7465feba 1212 die(_("offset before end of packfile (broken .idx?)"));
60bb8b14
SP
1213
1214 if (!win || !in_window(win, offset)) {
1215 if (win)
1216 win->inuse_cnt--;
1217 for (win = p->windows; win; win = win->next) {
1218 if (in_window(win, offset))
1219 break;
1220 }
1221 if (!win) {
78a28df9 1222 size_t window_align = packed_git_window_size / 2;
dc49cd76 1223 off_t len;
d131b7af
SP
1224
1225 if (p->pack_fd == -1 && open_packed_git(p))
1226 die("packfile %s cannot be accessed", p->pack_name);
1227
60bb8b14 1228 win = xcalloc(1, sizeof(*win));
78a28df9 1229 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
1230 len = p->pack_size - win->offset;
1231 if (len > packed_git_window_size)
1232 len = packed_git_window_size;
1233 win->len = (size_t)len;
60bb8b14 1234 pack_mapped += win->len;
11daf39b 1235 while (packed_git_limit < pack_mapped
7c3ecb32 1236 && unuse_one_window(p))
60bb8b14 1237 ; /* nothing */
c4712e45 1238 win->base = xmmap(NULL, win->len,
60bb8b14
SP
1239 PROT_READ, MAP_PRIVATE,
1240 p->pack_fd, win->offset);
1241 if (win->base == MAP_FAILED)
7616c6ca
NTND
1242 die_errno("packfile %s cannot be mapped",
1243 p->pack_name);
d131b7af 1244 if (!win->offset && win->len == p->pack_size
71fe5d7f
JS
1245 && !p->do_not_close)
1246 close_pack_fd(p);
a53128b6
SP
1247 pack_mmap_calls++;
1248 pack_open_windows++;
1249 if (pack_mapped > peak_pack_mapped)
1250 peak_pack_mapped = pack_mapped;
1251 if (pack_open_windows > peak_pack_open_windows)
1252 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
1253 win->next = p->windows;
1254 p->windows = win;
1255 }
1f688557 1256 }
03e79c88
SP
1257 if (win != *w_cursor) {
1258 win->last_used = pack_used_ctr++;
1259 win->inuse_cnt++;
1260 *w_cursor = win;
1261 }
60bb8b14 1262 offset -= win->offset;
03e79c88 1263 if (left)
dc49cd76 1264 *left = win->len - xsize_t(offset);
03e79c88 1265 return win->base + offset;
1f688557
JH
1266}
1267
27d69a46
NP
1268static struct packed_git *alloc_packed_git(int extra)
1269{
50a6c8ef 1270 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
27d69a46
NP
1271 memset(p, 0, sizeof(*p));
1272 p->pack_fd = -1;
1273 return p;
1274}
1275
e0500293
JN
1276static void try_to_free_pack_memory(size_t size)
1277{
7c3ecb32 1278 release_pack_memory(size);
e0500293
JN
1279}
1280
48bcc1c3 1281struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1f688557 1282{
e0500293 1283 static int have_set_try_to_free_routine;
1f688557 1284 struct stat st;
48bcc1c3
JK
1285 size_t alloc;
1286 struct packed_git *p;
1f688557 1287
e0500293
JN
1288 if (!have_set_try_to_free_routine) {
1289 have_set_try_to_free_routine = 1;
1290 set_try_to_free_routine(try_to_free_pack_memory);
1291 }
1292
42873078
NP
1293 /*
1294 * Make sure a corresponding .pack file exists and that
1295 * the index looks sane.
1296 */
48bcc1c3 1297 if (!strip_suffix_mem(path, &path_len, ".idx"))
1f688557 1298 return NULL;
48bcc1c3
JK
1299
1300 /*
1301 * ".pack" is long enough to hold any suffix we're adding (and
1302 * the use xsnprintf double-checks that)
1303 */
50a6c8ef 1304 alloc = st_add3(path_len, strlen(".pack"), 1);
48bcc1c3 1305 p = alloc_packed_git(alloc);
42873078 1306 memcpy(p->pack_name, path, path_len);
8d25931d 1307
48bcc1c3 1308 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
8d25931d
BC
1309 if (!access(p->pack_name, F_OK))
1310 p->pack_keep = 1;
1311
48bcc1c3 1312 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
d079837e 1313 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 1314 free(p);
1f688557
JH
1315 return NULL;
1316 }
42873078 1317
1f688557
JH
1318 /* ok, it looks sane as far as we can check without
1319 * actually mapping the pack file.
1320 */
1f688557 1321 p->pack_size = st.st_size;
9d835df2 1322 p->pack_local = local;
b867092f 1323 p->mtime = st.st_mtime;
42873078
NP
1324 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1325 hashclr(p->sha1);
1f688557
JH
1326 return p;
1327}
1328
7b64469a 1329struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 1330{
42873078 1331 const char *path = sha1_pack_name(sha1);
50a6c8ef 1332 size_t alloc = st_add(strlen(path), 1);
c7ab0ba3 1333 struct packed_git *p = alloc_packed_git(alloc);
bf592c50 1334
c7ab0ba3 1335 memcpy(p->pack_name, path, alloc); /* includes NUL */
27d69a46 1336 hashcpy(p->sha1, sha1);
42873078
NP
1337 if (check_packed_git_idx(idx_path, p)) {
1338 free(p);
bf592c50 1339 return NULL;
42873078 1340 }
bf592c50 1341
bf592c50
DB
1342 return p;
1343}
1344
1345void install_packed_git(struct packed_git *pack)
1346{
c7934306
SP
1347 if (pack->pack_fd != -1)
1348 pack_open_fds++;
1349
bf592c50
DB
1350 pack->next = packed_git;
1351 packed_git = pack;
1352}
1353
0a489b06 1354void (*report_garbage)(unsigned seen_bits, const char *path);
543c5caa
NTND
1355
1356static void report_helper(const struct string_list *list,
1357 int seen_bits, int first, int last)
1358{
0a489b06 1359 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
543c5caa 1360 return;
0a489b06 1361
543c5caa 1362 for (; first < last; first++)
0a489b06 1363 report_garbage(seen_bits, list->items[first].string);
543c5caa
NTND
1364}
1365
1366static void report_pack_garbage(struct string_list *list)
1367{
1368 int i, baselen = -1, first = 0, seen_bits = 0;
1369
1370 if (!report_garbage)
1371 return;
1372
3383e199 1373 string_list_sort(list);
543c5caa
NTND
1374
1375 for (i = 0; i < list->nr; i++) {
1376 const char *path = list->items[i].string;
1377 if (baselen != -1 &&
1378 strncmp(path, list->items[first].string, baselen)) {
1379 report_helper(list, seen_bits, first, i);
1380 baselen = -1;
1381 seen_bits = 0;
1382 }
1383 if (baselen == -1) {
1384 const char *dot = strrchr(path, '.');
1385 if (!dot) {
0a489b06 1386 report_garbage(PACKDIR_FILE_GARBAGE, path);
543c5caa
NTND
1387 continue;
1388 }
1389 baselen = dot - path + 1;
1390 first = i;
1391 }
1392 if (!strcmp(path + baselen, "pack"))
1393 seen_bits |= 1;
1394 else if (!strcmp(path + baselen, "idx"))
1395 seen_bits |= 2;
1396 }
1397 report_helper(list, seen_bits, first, list->nr);
1398}
1399
9d835df2 1400static void prepare_packed_git_one(char *objdir, int local)
1f688557 1401{
880fb8de
RS
1402 struct strbuf path = STRBUF_INIT;
1403 size_t dirnamelen;
1f688557
JH
1404 DIR *dir;
1405 struct dirent *de;
543c5caa 1406 struct string_list garbage = STRING_LIST_INIT_DUP;
1f688557 1407
880fb8de
RS
1408 strbuf_addstr(&path, objdir);
1409 strbuf_addstr(&path, "/pack");
1410 dir = opendir(path.buf);
b5b16990 1411 if (!dir) {
26125f6b 1412 if (errno != ENOENT)
7616c6ca
NTND
1413 error_errno("unable to open object pack directory: %s",
1414 path.buf);
880fb8de 1415 strbuf_release(&path);
1f688557 1416 return;
b5b16990 1417 }
880fb8de
RS
1418 strbuf_addch(&path, '/');
1419 dirnamelen = path.len;
1f688557 1420 while ((de = readdir(dir)) != NULL) {
1f688557 1421 struct packed_git *p;
47bf4b0f 1422 size_t base_len;
543c5caa
NTND
1423
1424 if (is_dot_or_dotdot(de->d_name))
9cb18f56
JM
1425 continue;
1426
880fb8de
RS
1427 strbuf_setlen(&path, dirnamelen);
1428 strbuf_addstr(&path, de->d_name);
d90906a9 1429
47bf4b0f
JK
1430 base_len = path.len;
1431 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
d90906a9
NTND
1432 /* Don't reopen a pack we already have. */
1433 for (p = packed_git; p; p = p->next) {
47bf4b0f
JK
1434 size_t len;
1435 if (strip_suffix(p->pack_name, ".pack", &len) &&
1436 len == base_len &&
1437 !memcmp(p->pack_name, path.buf, len))
d90906a9
NTND
1438 break;
1439 }
1440 if (p == NULL &&
1441 /*
1442 * See if it really is a valid .idx file with
1443 * corresponding .pack file that we can map.
1444 */
880fb8de 1445 (p = add_packed_git(path.buf, path.len, local)) != NULL)
d90906a9 1446 install_packed_git(p);
86f7780c 1447 }
543c5caa
NTND
1448
1449 if (!report_garbage)
1450 continue;
1451
2975c770
JK
1452 if (ends_with(de->d_name, ".idx") ||
1453 ends_with(de->d_name, ".pack") ||
1454 ends_with(de->d_name, ".bitmap") ||
1455 ends_with(de->d_name, ".keep"))
880fb8de 1456 string_list_append(&garbage, path.buf);
543c5caa 1457 else
0a489b06 1458 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1f688557 1459 }
5b35bcd5 1460 closedir(dir);
543c5caa
NTND
1461 report_pack_garbage(&garbage);
1462 string_list_clear(&garbage, 0);
880fb8de 1463 strbuf_release(&path);
1f688557
JH
1464}
1465
8e3f52d7
JK
1466static int approximate_object_count_valid;
1467
1468/*
1469 * Give a fast, rough count of the number of objects in the repository. This
1470 * ignores loose objects completely. If you have a lot of them, then either
1471 * you should repack because your performance will be awful, or they are
1472 * all unreachable objects about to be pruned, in which case they're not really
1473 * interesting as a measure of repo size in the first place.
1474 */
1475unsigned long approximate_object_count(void)
1476{
1477 static unsigned long count;
1478 if (!approximate_object_count_valid) {
1479 struct packed_git *p;
1480
1481 prepare_packed_git();
1482 count = 0;
1483 for (p = packed_git; p; p = p->next) {
1484 if (open_pack_index(p))
1485 continue;
1486 count += p->num_objects;
1487 }
1488 }
1489 return count;
1490}
1491
c4c6effa
RS
1492static void *get_next_packed_git(const void *p)
1493{
1494 return ((const struct packed_git *)p)->next;
1495}
1496
1497static void set_next_packed_git(void *p, void *next)
1498{
1499 ((struct packed_git *)p)->next = next;
1500}
1501
b867092f
JH
1502static int sort_pack(const void *a_, const void *b_)
1503{
c4c6effa
RS
1504 const struct packed_git *a = a_;
1505 const struct packed_git *b = b_;
b867092f
JH
1506 int st;
1507
1508 /*
1509 * Local packs tend to contain objects specific to our
1510 * variant of the project than remote ones. In addition,
1511 * remote ones could be on a network mounted filesystem.
1512 * Favor local ones for these reasons.
1513 */
1514 st = a->pack_local - b->pack_local;
1515 if (st)
1516 return -st;
1517
1518 /*
1519 * Younger packs tend to contain more recent objects,
1520 * and more recent objects tend to get accessed more
1521 * often.
1522 */
1523 if (a->mtime < b->mtime)
1524 return 1;
1525 else if (a->mtime == b->mtime)
1526 return 0;
1527 return -1;
1528}
1529
1530static void rearrange_packed_git(void)
1531{
c4c6effa
RS
1532 packed_git = llist_mergesort(packed_git, get_next_packed_git,
1533 set_next_packed_git, sort_pack);
b867092f
JH
1534}
1535
a73cdd21
JK
1536static void prepare_packed_git_mru(void)
1537{
1538 struct packed_git *p;
1539
1540 mru_clear(packed_git_mru);
1541 for (p = packed_git; p; p = p->next)
1542 mru_append(packed_git_mru, p);
1543}
1544
637cdd9d 1545static int prepare_packed_git_run_once = 0;
9a217f2a 1546void prepare_packed_git(void)
1f688557 1547{
d5a63b99 1548 struct alternate_object_database *alt;
1f688557 1549
637cdd9d 1550 if (prepare_packed_git_run_once)
1f688557 1551 return;
9d835df2 1552 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1553 prepare_alt_odb();
597f9134
JK
1554 for (alt = alt_odb_list; alt; alt = alt->next)
1555 prepare_packed_git_one(alt->path, 0);
b867092f 1556 rearrange_packed_git();
a73cdd21 1557 prepare_packed_git_mru();
637cdd9d
JK
1558 prepare_packed_git_run_once = 1;
1559}
1560
fc04c412 1561void reprepare_packed_git(void)
637cdd9d 1562{
8e3f52d7 1563 approximate_object_count_valid = 0;
637cdd9d
JK
1564 prepare_packed_git_run_once = 0;
1565 prepare_packed_git();
1f688557
JH
1566}
1567
8eca0b47
NP
1568static void mark_bad_packed_object(struct packed_git *p,
1569 const unsigned char *sha1)
1570{
1571 unsigned i;
1572 for (i = 0; i < p->num_bad_objects; i++)
50a6c8ef 1573 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
8eca0b47 1574 return;
50a6c8ef 1575 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
cd02599c 1576 st_mult(GIT_MAX_RAWSZ,
50a6c8ef
JK
1577 st_add(p->num_bad_objects, 1)));
1578 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
8eca0b47
NP
1579 p->num_bad_objects++;
1580}
1581
b6c4cecc 1582static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1583{
1584 struct packed_git *p;
1585 unsigned i;
1586
1587 for (p = packed_git; p; p = p->next)
1588 for (i = 0; i < p->num_bad_objects; i++)
1589 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1590 return p;
1591 return NULL;
ac939109
NP
1592}
1593
090ea126
NTND
1594/*
1595 * With an in-core object data in "map", rehash it to make sure the
1596 * object name actually matches "sha1" to detect object corruption.
1597 * With "map" == NULL, try reading the object named with "sha1" using
1598 * the streaming interface and rehash it to do the same.
1599 */
1600int check_sha1_signature(const unsigned char *sha1, void *map,
1601 unsigned long size, const char *type)
0fcfd160
LT
1602{
1603 unsigned char real_sha1[20];
090ea126
NTND
1604 enum object_type obj_type;
1605 struct git_istream *st;
1606 git_SHA_CTX c;
1607 char hdr[32];
1608 int hdrlen;
1609
1610 if (map) {
1611 hash_sha1_file(map, size, type, real_sha1);
1612 return hashcmp(sha1, real_sha1) ? -1 : 0;
1613 }
1614
1615 st = open_istream(sha1, &obj_type, &size, NULL);
1616 if (!st)
1617 return -1;
1618
1619 /* Generate the header */
ef1286d3 1620 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
090ea126
NTND
1621
1622 /* Sha1.. */
1623 git_SHA1_Init(&c);
1624 git_SHA1_Update(&c, hdr, hdrlen);
1625 for (;;) {
1626 char buf[1024 * 16];
1627 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1628
f54fac53
JK
1629 if (readlen < 0) {
1630 close_istream(st);
1631 return -1;
1632 }
090ea126
NTND
1633 if (!readlen)
1634 break;
1635 git_SHA1_Update(&c, buf, readlen);
1636 }
1637 git_SHA1_Final(real_sha1, &c);
1638 close_istream(st);
a89fccd2 1639 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1640}
1641
1b8ac5ea 1642int git_open_cloexec(const char *name, int flags)
44d1c19e 1643{
1e3001a8
JH
1644 int fd;
1645 static int o_cloexec = O_CLOEXEC;
f2e872aa 1646
1e3001a8
JH
1647 fd = open(name, flags | o_cloexec);
1648 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
cd66ada0 1649 /* Try again w/o O_CLOEXEC: the kernel might not support it */
1e3001a8
JH
1650 o_cloexec &= ~O_CLOEXEC;
1651 fd = open(name, flags | o_cloexec);
1b8ac5ea 1652 }
f2e872aa 1653
9fb9495d 1654#if defined(F_GETFD) && defined(F_SETFD) && defined(FD_CLOEXEC)
1e3001a8
JH
1655 {
1656 static int fd_cloexec = FD_CLOEXEC;
1657
1658 if (!o_cloexec && 0 <= fd && fd_cloexec) {
1659 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
9fb9495d
EW
1660 int flags = fcntl(fd, F_GETFD);
1661 if (fcntl(fd, F_SETFD, flags | fd_cloexec))
1e3001a8 1662 fd_cloexec = 0;
cd66ada0 1663 }
44d1c19e 1664 }
1e3001a8 1665#endif
1b8ac5ea 1666 return fd;
44d1c19e
LT
1667}
1668
771e7d57
JK
1669/*
1670 * Find "sha1" as a loose object in the local repository or in an alternate.
1671 * Returns 0 on success, negative on failure.
1672 *
1673 * The "path" out-parameter will give the path of the object we found (if any).
1674 * Note that it may point to static storage and is only valid until another
1675 * call to sha1_file_name(), etc.
1676 */
1677static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
1678 const char **path)
052fe5ea 1679{
052fe5ea
JK
1680 struct alternate_object_database *alt;
1681
771e7d57
JK
1682 *path = sha1_file_name(sha1);
1683 if (!lstat(*path, st))
052fe5ea
JK
1684 return 0;
1685
1686 prepare_alt_odb();
1687 errno = ENOENT;
1688 for (alt = alt_odb_list; alt; alt = alt->next) {
771e7d57
JK
1689 *path = alt_sha1_path(alt, sha1);
1690 if (!lstat(*path, st))
052fe5ea
JK
1691 return 0;
1692 }
1693
1694 return -1;
1695}
1696
771e7d57
JK
1697/*
1698 * Like stat_sha1_file(), but actually open the object and return the
1699 * descriptor. See the caveats on the "path" parameter above.
1700 */
1701static int open_sha1_file(const unsigned char *sha1, const char **path)
44d1c19e
LT
1702{
1703 int fd;
44d1c19e 1704 struct alternate_object_database *alt;
d6c8a05b 1705 int most_interesting_errno;
44d1c19e 1706
771e7d57
JK
1707 *path = sha1_file_name(sha1);
1708 fd = git_open(*path);
44d1c19e
LT
1709 if (fd >= 0)
1710 return fd;
d6c8a05b 1711 most_interesting_errno = errno;
44d1c19e
LT
1712
1713 prepare_alt_odb();
44d1c19e 1714 for (alt = alt_odb_list; alt; alt = alt->next) {
771e7d57
JK
1715 *path = alt_sha1_path(alt, sha1);
1716 fd = git_open(*path);
44d1c19e
LT
1717 if (fd >= 0)
1718 return fd;
d6c8a05b
JK
1719 if (most_interesting_errno == ENOENT)
1720 most_interesting_errno = errno;
44d1c19e 1721 }
d6c8a05b 1722 errno = most_interesting_errno;
44d1c19e
LT
1723 return -1;
1724}
1725
f6371f92
JK
1726/*
1727 * Map the loose object at "path" if it is not NULL, or the path found by
1728 * searching for a loose object named "sha1".
1729 */
1730static void *map_sha1_file_1(const char *path,
1731 const unsigned char *sha1,
1732 unsigned long *size)
0fcfd160 1733{
0fcfd160 1734 void *map;
144bde78 1735 int fd;
ace1534d 1736
f6371f92
JK
1737 if (path)
1738 fd = git_open(path);
1739 else
1740 fd = open_sha1_file(sha1, &path);
44d1c19e
LT
1741 map = NULL;
1742 if (fd >= 0) {
1743 struct stat st;
0fcfd160 1744
44d1c19e
LT
1745 if (!fstat(fd, &st)) {
1746 *size = xsize_t(st.st_size);
33e42de0
MM
1747 if (!*size) {
1748 /* mmap() is forbidden on empty files */
771e7d57 1749 error("object file %s is empty", path);
33e42de0
MM
1750 return NULL;
1751 }
44d1c19e 1752 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1753 }
44d1c19e 1754 close(fd);
0fcfd160 1755 }
0fcfd160
LT
1756 return map;
1757}
1758
f6371f92
JK
1759void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1760{
1761 return map_sha1_file_1(NULL, sha1, size);
1762}
1763
09ded04b
NP
1764unsigned long unpack_object_header_buffer(const unsigned char *buf,
1765 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1766{
ad1ed5ee 1767 unsigned shift;
48fb7deb 1768 unsigned long size, c;
ad1ed5ee
JH
1769 unsigned long used = 0;
1770
1771 c = buf[used++];
1772 *type = (c >> 4) & 7;
1773 size = c & 15;
1774 shift = 4;
1775 while (c & 0x80) {
f630cfda 1776 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1777 error("bad object header");
ea4f9685
JH
1778 size = used = 0;
1779 break;
09ded04b 1780 }
ad1ed5ee
JH
1781 c = buf[used++];
1782 size += (c & 0x7f) << shift;
1783 shift += 7;
1784 }
1785 *sizep = size;
1786 return used;
1787}
1788
d21f8426
JH
1789static int unpack_sha1_short_header(git_zstream *stream,
1790 unsigned char *map, unsigned long mapsize,
1791 void *buffer, unsigned long bufsiz)
ad1ed5ee 1792{
c4483576
LT
1793 /* Get the data stream */
1794 memset(stream, 0, sizeof(*stream));
1795 stream->next_in = map;
1796 stream->avail_in = mapsize;
1797 stream->next_out = buffer;
93821bd9
LT
1798 stream->avail_out = bufsiz;
1799
39c68542 1800 git_inflate_init(stream);
cc5c54e7 1801 return git_inflate(stream, 0);
c4483576
LT
1802}
1803
d21f8426
JH
1804int unpack_sha1_header(git_zstream *stream,
1805 unsigned char *map, unsigned long mapsize,
1806 void *buffer, unsigned long bufsiz)
1807{
1808 int status = unpack_sha1_short_header(stream, map, mapsize,
1809 buffer, bufsiz);
1810
1811 if (status < Z_OK)
1812 return status;
1813
1814 /* Make sure we have the terminating NUL */
1815 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1816 return -1;
1817 return 0;
1818}
1819
46f03448
KN
1820static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1821 unsigned long mapsize, void *buffer,
1822 unsigned long bufsiz, struct strbuf *header)
1823{
1824 int status;
1825
d21f8426
JH
1826 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
1827 if (status < Z_OK)
1828 return -1;
46f03448
KN
1829
1830 /*
1831 * Check if entire header is unpacked in the first iteration.
1832 */
1833 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1834 return 0;
1835
1836 /*
1837 * buffer[0..bufsiz] was not large enough. Copy the partial
1838 * result out to header, and then append the result of further
1839 * reading the stream.
1840 */
1841 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1842 stream->next_out = buffer;
1843 stream->avail_out = bufsiz;
1844
1845 do {
1846 status = git_inflate(stream, 0);
1847 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1848 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1849 return 0;
1850 stream->next_out = buffer;
1851 stream->avail_out = bufsiz;
1852 } while (status != Z_STREAM_END);
1853 return -1;
1854}
1855
ef49a7a0 1856static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1857{
1858 int bytes = strlen(buffer) + 1;
3aee68aa 1859 unsigned char *buf = xmallocz(size);
93821bd9 1860 unsigned long n;
7efbff75 1861 int status = Z_OK;
5180cacc 1862
93821bd9
LT
1863 n = stream->total_out - bytes;
1864 if (n > size)
1865 n = size;
1866 memcpy(buf, (char *) buffer + bytes, n);
1867 bytes = n;
456cdf6e
LT
1868 if (bytes <= size) {
1869 /*
1870 * The above condition must be (bytes <= size), not
1871 * (bytes < size). In other words, even though we
ccf5ace0 1872 * expect no more output and set avail_out to zero,
456cdf6e
LT
1873 * the input zlib stream may have bytes that express
1874 * "this concludes the stream", and we *do* want to
1875 * eat that input.
1876 *
1877 * Otherwise we would not be able to test that we
1878 * consumed all the input to reach the expected size;
1879 * we also want to check that zlib tells us that all
1880 * went well with status == Z_STREAM_END at the end.
1881 */
5180cacc
LT
1882 stream->next_out = buf + bytes;
1883 stream->avail_out = size - bytes;
7efbff75 1884 while (status == Z_OK)
39c68542 1885 status = git_inflate(stream, Z_FINISH);
5180cacc 1886 }
456cdf6e 1887 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1888 git_inflate_end(stream);
7efbff75
JH
1889 return buf;
1890 }
1891
1892 if (status < 0)
1893 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1894 else if (stream->avail_in)
1895 error("garbage at end of loose object '%s'",
1896 sha1_to_hex(sha1));
1897 free(buf);
1898 return NULL;
5180cacc
LT
1899}
1900
1901/*
1902 * We used to just use "sscanf()", but that's actually way
1903 * too permissive for what we want to check. So do an anal
1904 * object header parse by hand.
1905 */
46f03448
KN
1906static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1907 unsigned int flags)
5180cacc 1908{
46f03448 1909 const char *type_buf = hdr;
5180cacc 1910 unsigned long size;
46f03448 1911 int type, type_len = 0;
5180cacc
LT
1912
1913 /*
46f03448 1914 * The type can be of any size but is followed by
21666f1a 1915 * a space.
5180cacc 1916 */
5180cacc
LT
1917 for (;;) {
1918 char c = *hdr++;
d21f8426
JH
1919 if (!c)
1920 return -1;
5180cacc
LT
1921 if (c == ' ')
1922 break;
46f03448 1923 type_len++;
5180cacc 1924 }
46f03448
KN
1925
1926 type = type_from_string_gently(type_buf, type_len, 1);
1927 if (oi->typename)
1928 strbuf_add(oi->typename, type_buf, type_len);
1929 /*
1930 * Set type to 0 if its an unknown object and
2e3a16b2 1931 * we're obtaining the type using '--allow-unknown-type'
46f03448
KN
1932 * option.
1933 */
19fc5e84 1934 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE) && (type < 0))
46f03448
KN
1935 type = 0;
1936 else if (type < 0)
1937 die("invalid object type");
1938 if (oi->typep)
1939 *oi->typep = type;
5180cacc
LT
1940
1941 /*
1942 * The length must follow immediately, and be in canonical
1943 * decimal format (ie "010" is not valid).
1944 */
1945 size = *hdr++ - '0';
1946 if (size > 9)
1947 return -1;
1948 if (size) {
1949 for (;;) {
1950 unsigned long c = *hdr - '0';
1951 if (c > 9)
1952 break;
1953 hdr++;
1954 size = size * 10 + c;
1955 }
1956 }
46f03448
KN
1957
1958 if (oi->sizep)
1959 *oi->sizep = size;
5180cacc
LT
1960
1961 /*
1962 * The length must be followed by a zero byte
1963 */
46f03448
KN
1964 return *hdr ? -1 : type;
1965}
1966
1967int parse_sha1_header(const char *hdr, unsigned long *sizep)
1968{
27b5c1a0 1969 struct object_info oi = OBJECT_INFO_INIT;
46f03448
KN
1970
1971 oi.sizep = sizep;
1f0c0d36 1972 return parse_sha1_header_extended(hdr, &oi, 0);
0fcfd160
LT
1973}
1974
54dab52a
NP
1975unsigned long get_size_from_delta(struct packed_git *p,
1976 struct pack_window **w_curs,
1977 off_t curpos)
1978{
1979 const unsigned char *data;
1980 unsigned char delta_head[20], *in;
ef49a7a0 1981 git_zstream stream;
54dab52a
NP
1982 int st;
1983
1984 memset(&stream, 0, sizeof(stream));
1985 stream.next_out = delta_head;
1986 stream.avail_out = sizeof(delta_head);
1987
39c68542 1988 git_inflate_init(&stream);
54dab52a
NP
1989 do {
1990 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1991 stream.next_in = in;
39c68542 1992 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1993 curpos += stream.next_in - in;
1994 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1995 stream.total_out < sizeof(delta_head));
39c68542 1996 git_inflate_end(&stream);
3d77d877
NP
1997 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1998 error("delta data unpack-initial failed");
1999 return 0;
2000 }
54dab52a
NP
2001
2002 /* Examine the initial part of the delta to figure out
2003 * the result size.
2004 */
2005 data = delta_head;
2006
2007 /* ignore base size */
2008 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2009
2010 /* Read the result size */
2011 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
2012}
2013
c4001d92 2014static off_t get_delta_base(struct packed_git *p,
03e79c88 2015 struct pack_window **w_curs,
c4001d92 2016 off_t *curpos,
21666f1a 2017 enum object_type type,
c4001d92 2018 off_t delta_obj_offset)
eb32d236 2019{
2b87c45b 2020 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 2021 off_t base_offset;
eb32d236 2022
8d8a4ea5
SP
2023 /* use_pack() assured us we have [base_info, base_info + 20)
2024 * as a range that we can look at without walking off the
2025 * end of the mapped window. Its actually the hash size
2026 * that is assured. An OFS_DELTA longer than the hash size
2027 * is stupid, as then a REF_DELTA would be smaller to store.
2028 */
21666f1a 2029 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
2030 unsigned used = 0;
2031 unsigned char c = base_info[used++];
2032 base_offset = c & 127;
2033 while (c & 128) {
2034 base_offset += 1;
8723f216 2035 if (!base_offset || MSB(base_offset, 7))
8eca0b47 2036 return 0; /* overflow */
eb32d236
NP
2037 c = base_info[used++];
2038 base_offset = (base_offset << 7) + (c & 127);
2039 }
2040 base_offset = delta_obj_offset - base_offset;
d8f32556 2041 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 2042 return 0; /* out of bound */
2b87c45b 2043 *curpos += used;
21666f1a 2044 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
2045 /* The base entry _must_ be in the same pack */
2046 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 2047 *curpos += 20;
eb32d236
NP
2048 } else
2049 die("I am totally screwed");
2b87c45b 2050 return base_offset;
eb32d236
NP
2051}
2052
5d642e75
JK
2053/*
2054 * Like get_delta_base above, but we return the sha1 instead of the pack
2055 * offset. This means it is cheaper for REF deltas (we do not have to do
2056 * the final object lookup), but more expensive for OFS deltas (we
2057 * have to load the revidx to convert the offset back into a sha1).
2058 */
2059static const unsigned char *get_delta_base_sha1(struct packed_git *p,
2060 struct pack_window **w_curs,
2061 off_t curpos,
2062 enum object_type type,
2063 off_t delta_obj_offset)
2064{
2065 if (type == OBJ_REF_DELTA) {
2066 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
2067 return base;
2068 } else if (type == OBJ_OFS_DELTA) {
2069 struct revindex_entry *revidx;
2070 off_t base_offset = get_delta_base(p, w_curs, &curpos,
2071 type, delta_obj_offset);
2072
2073 if (!base_offset)
2074 return NULL;
2075
2076 revidx = find_pack_revindex(p, base_offset);
2077 if (!revidx)
2078 return NULL;
2079
2080 return nth_packed_object_sha1(p, revidx->nr);
2081 } else
2082 return NULL;
2083}
2084
f8c8abc5
JH
2085int unpack_object_header(struct packed_git *p,
2086 struct pack_window **w_curs,
2087 off_t *curpos,
2088 unsigned long *sizep)
a733cb60 2089{
03e79c88 2090 unsigned char *base;
ef49a7a0 2091 unsigned long left;
ad1ed5ee 2092 unsigned long used;
2b87c45b 2093 enum object_type type;
a733cb60 2094
8d8a4ea5 2095 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 2096 * as a range that we can look at. (Its actually the hash
3dff5379 2097 * size that is assured.) With our object header encoding
8d8a4ea5
SP
2098 * the maximum deflated object size is 2^137, which is just
2099 * insane, so we know won't exceed what we have been given.
2100 */
2b87c45b 2101 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
2102 used = unpack_object_header_buffer(base, left, &type, sizep);
2103 if (!used) {
2104 type = OBJ_BAD;
2105 } else
2106 *curpos += used;
ad1ed5ee 2107
2b87c45b 2108 return type;
a733cb60
LT
2109}
2110
790d96c0
TR
2111static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
2112{
2113 int type;
2114 struct revindex_entry *revidx;
2115 const unsigned char *sha1;
2116 revidx = find_pack_revindex(p, obj_offset);
2117 if (!revidx)
2118 return OBJ_BAD;
2119 sha1 = nth_packed_object_sha1(p, revidx->nr);
2120 mark_bad_packed_object(p, sha1);
2121 type = sha1_object_info(sha1, NULL);
2122 if (type <= OBJ_NONE)
2123 return OBJ_BAD;
2124 return type;
2125}
2126
790d96c0
TR
2127#define POI_STACK_PREALLOC 64
2128
90191d37
JK
2129static enum object_type packed_to_object_type(struct packed_git *p,
2130 off_t obj_offset,
2131 enum object_type type,
2132 struct pack_window **w_curs,
2133 off_t curpos)
1f688557 2134{
790d96c0
TR
2135 off_t small_poi_stack[POI_STACK_PREALLOC];
2136 off_t *poi_stack = small_poi_stack;
2137 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
5db47c2b 2138
790d96c0
TR
2139 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2140 off_t base_offset;
90191d37 2141 unsigned long size;
790d96c0
TR
2142 /* Push the object we're going to leave behind */
2143 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
2144 poi_stack_alloc = alloc_nr(poi_stack_nr);
b32fa95f 2145 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
790d96c0
TR
2146 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
2147 } else {
2148 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
2149 }
2150 poi_stack[poi_stack_nr++] = obj_offset;
2151 /* If parsing the base offset fails, just unwind */
90191d37 2152 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
790d96c0
TR
2153 if (!base_offset)
2154 goto unwind;
2155 curpos = obj_offset = base_offset;
90191d37 2156 type = unpack_object_header(p, w_curs, &curpos, &size);
790d96c0
TR
2157 if (type <= OBJ_NONE) {
2158 /* If getting the base itself fails, we first
2159 * retry the base, otherwise unwind */
2160 type = retry_bad_packed_offset(p, base_offset);
2161 if (type > OBJ_NONE)
2162 goto out;
2163 goto unwind;
2164 }
2165 }
2166
21666f1a 2167 switch (type) {
790d96c0 2168 case OBJ_BAD:
a733cb60 2169 case OBJ_COMMIT:
a733cb60 2170 case OBJ_TREE:
a733cb60 2171 case OBJ_BLOB:
a733cb60 2172 case OBJ_TAG:
a69d0943 2173 break;
1f688557 2174 default:
3d77d877
NP
2175 error("unknown object type %i at offset %"PRIuMAX" in %s",
2176 type, (uintmax_t)obj_offset, p->pack_name);
2177 type = OBJ_BAD;
1f688557 2178 }
790d96c0
TR
2179
2180out:
2181 if (poi_stack != small_poi_stack)
2182 free(poi_stack);
21666f1a 2183 return type;
790d96c0
TR
2184
2185unwind:
2186 while (poi_stack_nr) {
2187 obj_offset = poi_stack[--poi_stack_nr];
2188 type = retry_bad_packed_offset(p, obj_offset);
2189 if (type > OBJ_NONE)
2190 goto out;
2191 }
2192 type = OBJ_BAD;
2193 goto out;
1f688557
JH
2194}
2195
8261e1f1 2196static struct hashmap delta_base_cache;
18bdec11 2197static size_t delta_base_cached;
5e08ecbf 2198
12d95ef6 2199static LIST_HEAD(delta_base_cache_lru);
5e08ecbf 2200
8261e1f1 2201struct delta_base_cache_key {
e5e01619
LT
2202 struct packed_git *p;
2203 off_t base_offset;
8261e1f1
JK
2204};
2205
2206struct delta_base_cache_entry {
2207 struct hashmap hash;
2208 struct delta_base_cache_key key;
2209 struct list_head lru;
2210 void *data;
e5e01619 2211 unsigned long size;
e5e01619 2212 enum object_type type;
8261e1f1 2213};
e5e01619 2214
8261e1f1 2215static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
e5e01619 2216{
8261e1f1 2217 unsigned int hash;
e5e01619 2218
8261e1f1 2219 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
e5e01619 2220 hash += (hash >> 8) + (hash >> 16);
8261e1f1 2221 return hash;
e5e01619
LT
2222}
2223
84dd81c1
TR
2224static struct delta_base_cache_entry *
2225get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
5266d369 2226{
8261e1f1
JK
2227 struct hashmap_entry entry;
2228 struct delta_base_cache_key key;
2229
2230 if (!delta_base_cache.cmpfn)
2231 return NULL;
2232
2233 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
2234 key.p = p;
2235 key.base_offset = base_offset;
2236 return hashmap_get(&delta_base_cache, &entry, &key);
2237}
2238
2239static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
2240 const struct delta_base_cache_key *b)
2241{
2242 return a->p == b->p && a->base_offset == b->base_offset;
84dd81c1
TR
2243}
2244
7663cdc8
SB
2245static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
2246 const void *va, const void *vb,
8261e1f1 2247 const void *vkey)
84dd81c1 2248{
8261e1f1
JK
2249 const struct delta_base_cache_entry *a = va, *b = vb;
2250 const struct delta_base_cache_key *key = vkey;
2251 if (key)
2252 return !delta_base_cache_key_eq(&a->key, key);
2253 else
2254 return !delta_base_cache_key_eq(&a->key, &b->key);
5266d369
JH
2255}
2256
84dd81c1
TR
2257static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2258{
8261e1f1 2259 return !!get_delta_base_cache_entry(p, base_offset);
84dd81c1
TR
2260}
2261
4a5397ca
JK
2262/*
2263 * Remove the entry from the cache, but do _not_ free the associated
2264 * entry data. The caller takes ownership of the "data" buffer, and
2265 * should copy out any fields it wants before detaching.
2266 */
2267static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
84dd81c1 2268{
8261e1f1 2269 hashmap_remove(&delta_base_cache, ent, &ent->key);
12d95ef6 2270 list_del(&ent->lru);
84dd81c1 2271 delta_base_cached -= ent->size;
8261e1f1 2272 free(ent);
84dd81c1
TR
2273}
2274
62f255ad 2275static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
85fe35ab 2276 unsigned long *base_size, enum object_type *type)
62f255ad 2277{
84dd81c1 2278 struct delta_base_cache_entry *ent;
e5e01619 2279
84dd81c1 2280 ent = get_delta_base_cache_entry(p, base_offset);
8261e1f1 2281 if (!ent)
749bc58c 2282 return unpack_entry(p, base_offset, type, base_size);
e5e01619 2283
c84a1f3e
JT
2284 if (type)
2285 *type = ent->type;
2286 if (base_size)
2287 *base_size = ent->size;
85fe35ab 2288 return xmemdupz(ent->data, ent->size);
62f255ad
LT
2289}
2290
18bdec11
SP
2291static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2292{
8261e1f1
JK
2293 free(ent->data);
2294 detach_delta_base_cache_entry(ent);
18bdec11
SP
2295}
2296
3d20c636
SP
2297void clear_delta_base_cache(void)
2298{
abd5a002
JK
2299 struct list_head *lru, *tmp;
2300 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2301 struct delta_base_cache_entry *entry =
2302 list_entry(lru, struct delta_base_cache_entry, lru);
8261e1f1
JK
2303 release_delta_base_cache(entry);
2304 }
3d20c636
SP
2305}
2306
62f255ad
LT
2307static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2308 void *base, unsigned long base_size, enum object_type type)
2309{
8261e1f1 2310 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
4b92bae7 2311 struct list_head *lru, *tmp;
e5e01619 2312
18bdec11 2313 delta_base_cached += base_size;
5e08ecbf 2314
4b92bae7 2315 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
12d95ef6
JK
2316 struct delta_base_cache_entry *f =
2317 list_entry(lru, struct delta_base_cache_entry, lru);
2318 if (delta_base_cached <= delta_base_cache_limit)
2319 break;
5e08ecbf
NP
2320 release_delta_base_cache(f);
2321 }
18bdec11 2322
8261e1f1
JK
2323 ent->key.p = p;
2324 ent->key.base_offset = base_offset;
e5e01619
LT
2325 ent->type = type;
2326 ent->data = base;
2327 ent->size = base_size;
12d95ef6 2328 list_add_tail(&ent->lru, &delta_base_cache_lru);
8261e1f1
JK
2329
2330 if (!delta_base_cache.cmpfn)
7663cdc8 2331 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
8261e1f1
JK
2332 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
2333 hashmap_add(&delta_base_cache, ent);
62f255ad
LT
2334}
2335
845b102b
JT
2336int packed_object_info(struct packed_git *p, off_t obj_offset,
2337 struct object_info *oi)
2338{
2339 struct pack_window *w_curs = NULL;
2340 unsigned long size;
2341 off_t curpos = obj_offset;
2342 enum object_type type;
2343
2344 /*
2345 * We always get the representation type, but only convert it to
2346 * a "real" type later if the caller is interested.
2347 */
c84a1f3e
JT
2348 if (oi->contentp) {
2349 *oi->contentp = cache_or_unpack_entry(p, obj_offset, oi->sizep,
2350 &type);
2351 if (!*oi->contentp)
2352 type = OBJ_BAD;
2353 } else {
2354 type = unpack_object_header(p, &w_curs, &curpos, &size);
2355 }
845b102b 2356
c84a1f3e 2357 if (!oi->contentp && oi->sizep) {
845b102b
JT
2358 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2359 off_t tmp_pos = curpos;
2360 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2361 type, obj_offset);
2362 if (!base_offset) {
2363 type = OBJ_BAD;
2364 goto out;
2365 }
2366 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2367 if (*oi->sizep == 0) {
2368 type = OBJ_BAD;
2369 goto out;
2370 }
2371 } else {
2372 *oi->sizep = size;
2373 }
2374 }
2375
2376 if (oi->disk_sizep) {
2377 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2378 *oi->disk_sizep = revidx[1].offset - obj_offset;
2379 }
2380
2381 if (oi->typep || oi->typename) {
2382 enum object_type ptot;
2383 ptot = packed_to_object_type(p, obj_offset, type, &w_curs,
2384 curpos);
2385 if (oi->typep)
2386 *oi->typep = ptot;
2387 if (oi->typename) {
2388 const char *tn = typename(ptot);
2389 if (tn)
2390 strbuf_addstr(oi->typename, tn);
2391 }
2392 if (ptot < 0) {
2393 type = OBJ_BAD;
2394 goto out;
2395 }
2396 }
2397
2398 if (oi->delta_base_sha1) {
2399 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2400 const unsigned char *base;
2401
2402 base = get_delta_base_sha1(p, &w_curs, curpos,
2403 type, obj_offset);
2404 if (!base) {
2405 type = OBJ_BAD;
2406 goto out;
2407 }
2408
2409 hashcpy(oi->delta_base_sha1, base);
2410 } else
2411 hashclr(oi->delta_base_sha1);
2412 }
2413
3ab0fb06
JT
2414 oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
2415 OI_PACKED;
2416
845b102b
JT
2417out:
2418 unuse_pack(&w_curs);
2419 return type;
2420}
2421
2422static void *unpack_compressed_entry(struct packed_git *p,
2423 struct pack_window **w_curs,
2424 off_t curpos,
2425 unsigned long size)
2426{
2427 int st;
2428 git_zstream stream;
2429 unsigned char *buffer, *in;
2430
2431 buffer = xmallocz_gently(size);
2432 if (!buffer)
2433 return NULL;
2434 memset(&stream, 0, sizeof(stream));
2435 stream.next_out = buffer;
2436 stream.avail_out = size + 1;
2437
2438 git_inflate_init(&stream);
2439 do {
2440 in = use_pack(p, w_curs, curpos, &stream.avail_in);
2441 stream.next_in = in;
2442 st = git_inflate(&stream, Z_FINISH);
2443 if (!stream.avail_out)
2444 break; /* the payload is larger than it should be */
2445 curpos += stream.next_in - in;
2446 } while (st == Z_OK || st == Z_BUF_ERROR);
2447 git_inflate_end(&stream);
2448 if ((st != Z_STREAM_END) || stream.total_out != size) {
2449 free(buffer);
2450 return NULL;
2451 }
2452
2453 return buffer;
2454}
2455
c2c5b270
CC
2456static void *read_object(const unsigned char *sha1, enum object_type *type,
2457 unsigned long *size);
2458
5f44324d
JH
2459static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2460{
67dc598e
KB
2461 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2462 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2463 p->pack_name, (uintmax_t)obj_offset);
5f44324d
JH
2464}
2465
0e8189e2
NP
2466int do_check_packed_object_crc;
2467
abe601bb
TR
2468#define UNPACK_ENTRY_STACK_PREALLOC 64
2469struct unpack_entry_stack_ent {
2470 off_t obj_offset;
2471 off_t curpos;
2472 unsigned long size;
2473};
2474
c4001d92 2475void *unpack_entry(struct packed_git *p, off_t obj_offset,
abe601bb 2476 enum object_type *final_type, unsigned long *final_size)
1f688557 2477{
03e79c88 2478 struct pack_window *w_curs = NULL;
c4001d92 2479 off_t curpos = obj_offset;
abe601bb
TR
2480 void *data = NULL;
2481 unsigned long size;
2482 enum object_type type;
2483 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2484 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2485 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2486 int base_from_cache = 0;
1f688557 2487
67dc598e 2488 write_pack_access_log(p, obj_offset);
5f44324d 2489
abe601bb
TR
2490 /* PHASE 1: drill down to the innermost base object */
2491 for (;;) {
2492 off_t base_offset;
2493 int i;
2494 struct delta_base_cache_entry *ent;
2495
77965f8b 2496 ent = get_delta_base_cache_entry(p, curpos);
8261e1f1 2497 if (ent) {
77965f8b
NTND
2498 type = ent->type;
2499 data = ent->data;
2500 size = ent->size;
4a5397ca 2501 detach_delta_base_cache_entry(ent);
77965f8b
NTND
2502 base_from_cache = 1;
2503 break;
2504 }
2505
abe601bb
TR
2506 if (do_check_packed_object_crc && p->index_version > 1) {
2507 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
211c61c6 2508 off_t len = revidx[1].offset - obj_offset;
abe601bb
TR
2509 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2510 const unsigned char *sha1 =
2511 nth_packed_object_sha1(p, revidx->nr);
2512 error("bad packed object CRC for %s",
2513 sha1_to_hex(sha1));
2514 mark_bad_packed_object(p, sha1);
896dca3a
RS
2515 data = NULL;
2516 goto out;
abe601bb
TR
2517 }
2518 }
2519
abe601bb
TR
2520 type = unpack_object_header(p, &w_curs, &curpos, &size);
2521 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2522 break;
2523
2524 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2525 if (!base_offset) {
2526 error("failed to validate delta base reference "
2527 "at offset %"PRIuMAX" from %s",
2528 (uintmax_t)curpos, p->pack_name);
2529 /* bail to phase 2, in hopes of recovery */
2530 data = NULL;
2531 break;
2532 }
2533
2534 /* push object, proceed to base */
2535 if (delta_stack_nr >= delta_stack_alloc
2536 && delta_stack == small_delta_stack) {
2537 delta_stack_alloc = alloc_nr(delta_stack_nr);
b32fa95f 2538 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
abe601bb
TR
2539 memcpy(delta_stack, small_delta_stack,
2540 sizeof(*delta_stack)*delta_stack_nr);
2541 } else {
2542 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2543 }
2544 i = delta_stack_nr++;
2545 delta_stack[i].obj_offset = obj_offset;
2546 delta_stack[i].curpos = curpos;
2547 delta_stack[i].size = size;
2548
2549 curpos = obj_offset = base_offset;
0e8189e2
NP
2550 }
2551
abe601bb
TR
2552 /* PHASE 2: handle the base */
2553 switch (type) {
eb32d236
NP
2554 case OBJ_OFS_DELTA:
2555 case OBJ_REF_DELTA:
abe601bb 2556 if (data)
ef1177d1 2557 die("BUG: unpack_entry: left loop at a valid delta");
4d703a1a 2558 break;
a733cb60 2559 case OBJ_COMMIT:
a733cb60 2560 case OBJ_TREE:
a733cb60 2561 case OBJ_BLOB:
a733cb60 2562 case OBJ_TAG:
abe601bb
TR
2563 if (!base_from_cache)
2564 data = unpack_compressed_entry(p, &w_curs, curpos, size);
4d703a1a 2565 break;
1f688557 2566 default:
8eca0b47
NP
2567 data = NULL;
2568 error("unknown object type %i at offset %"PRIuMAX" in %s",
abe601bb
TR
2569 type, (uintmax_t)obj_offset, p->pack_name);
2570 }
2571
2572 /* PHASE 3: apply deltas in order */
2573
2574 /* invariants:
2575 * 'data' holds the base data, or NULL if there was corruption
2576 */
2577 while (delta_stack_nr) {
2578 void *delta_data;
2579 void *base = data;
886ddf47 2580 void *external_base = NULL;
abe601bb
TR
2581 unsigned long delta_size, base_size = size;
2582 int i;
2583
2584 data = NULL;
2585
2586 if (base)
2587 add_delta_base_cache(p, obj_offset, base, base_size, type);
2588
2589 if (!base) {
2590 /*
2591 * We're probably in deep shit, but let's try to fetch
2592 * the required base anyway from another pack or loose.
2593 * This is costly but should happen only in the presence
2594 * of a corrupted pack, and is better than failing outright.
2595 */
2596 struct revindex_entry *revidx;
2597 const unsigned char *base_sha1;
2598 revidx = find_pack_revindex(p, obj_offset);
2599 if (revidx) {
2600 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2601 error("failed to read delta base object %s"
2602 " at offset %"PRIuMAX" from %s",
2603 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2604 p->pack_name);
2605 mark_bad_packed_object(p, base_sha1);
2606 base = read_object(base_sha1, &type, &base_size);
886ddf47 2607 external_base = base;
abe601bb
TR
2608 }
2609 }
2610
2611 i = --delta_stack_nr;
2612 obj_offset = delta_stack[i].obj_offset;
2613 curpos = delta_stack[i].curpos;
2614 delta_size = delta_stack[i].size;
2615
2616 if (!base)
2617 continue;
2618
2619 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2620
2621 if (!delta_data) {
2622 error("failed to unpack compressed delta "
2623 "at offset %"PRIuMAX" from %s",
2624 (uintmax_t)curpos, p->pack_name);
abe601bb 2625 data = NULL;
886ddf47 2626 free(external_base);
abe601bb
TR
2627 continue;
2628 }
2629
2630 data = patch_delta(base, base_size,
2631 delta_data, delta_size,
2632 &size);
1ee886c1
JK
2633
2634 /*
2635 * We could not apply the delta; warn the user, but keep going.
2636 * Our failure will be noticed either in the next iteration of
2637 * the loop, or if this is the final delta, in the caller when
2638 * we return NULL. Those code paths will take care of making
2639 * a more explicit warning and retrying with another copy of
2640 * the object.
2641 */
abe601bb 2642 if (!data)
1ee886c1 2643 error("failed to apply delta");
abe601bb 2644
4b8f772c 2645 free(delta_data);
886ddf47 2646 free(external_base);
1f688557 2647 }
abe601bb 2648
c84a1f3e
JT
2649 if (final_type)
2650 *final_type = type;
2651 if (final_size)
2652 *final_size = size;
abe601bb 2653
896dca3a 2654out:
03e79c88 2655 unuse_pack(&w_curs);
019d1e65
NTND
2656
2657 if (delta_stack != small_delta_stack)
2658 free(delta_stack);
2659
21666f1a 2660 return data;
1f688557
JH
2661}
2662
d079837e 2663const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 2664 uint32_t n)
9a217f2a 2665{
42873078 2666 const unsigned char *index = p->index_data;
d079837e
SP
2667 if (!index) {
2668 if (open_pack_index(p))
2669 return NULL;
2670 index = p->index_data;
2671 }
57059091 2672 if (n >= p->num_objects)
d72308e0 2673 return NULL;
74e34e1f
NP
2674 index += 4 * 256;
2675 if (p->index_version == 1) {
2676 return index + 24 * n + 4;
2677 } else {
2678 index += 8;
2679 return index + 20 * n;
2680 }
2681}
2682
068f85e3 2683const struct object_id *nth_packed_object_oid(struct object_id *oid,
2684 struct packed_git *p,
2685 uint32_t n)
2686{
2687 const unsigned char *hash = nth_packed_object_sha1(p, n);
2688 if (!hash)
2689 return NULL;
2690 hashcpy(oid->hash, hash);
2691 return oid;
2692}
2693
47fe3f6e
JK
2694void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2695{
2696 const unsigned char *ptr = vptr;
2697 const unsigned char *start = p->index_data;
2698 const unsigned char *end = start + p->index_size;
2699 if (ptr < start)
7465feba 2700 die(_("offset before start of pack index for %s (corrupt index?)"),
47fe3f6e
JK
2701 p->pack_name);
2702 /* No need to check for underflow; .idx files must be at least 8 bytes */
2703 if (ptr >= end - 8)
7465feba 2704 die(_("offset beyond end of pack index for %s (truncated index?)"),
47fe3f6e
JK
2705 p->pack_name);
2706}
2707
99093238 2708off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
2709{
2710 const unsigned char *index = p->index_data;
2711 index += 4 * 256;
2712 if (p->index_version == 1) {
2713 return ntohl(*((uint32_t *)(index + 24 * n)));
2714 } else {
2715 uint32_t off;
2716 index += 8 + p->num_objects * (20 + 4);
2717 off = ntohl(*((uint32_t *)(index + 4 * n)));
2718 if (!(off & 0x80000000))
2719 return off;
2720 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
47fe3f6e 2721 check_pack_index_ptr(p, index);
74e34e1f
NP
2722 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2723 ntohl(*((uint32_t *)(index + 4)));
2724 }
9a217f2a
JH
2725}
2726
c4001d92 2727off_t find_pack_entry_one(const unsigned char *sha1,
43057304 2728 struct packed_git *p)
1f688557 2729{
42873078 2730 const uint32_t *level1_ofs = p->index_data;
42873078 2731 const unsigned char *index = p->index_data;
628522ec 2732 unsigned hi, lo, stride;
628522ec
JH
2733 static int debug_lookup = -1;
2734
2735 if (debug_lookup < 0)
2736 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 2737
d079837e
SP
2738 if (!index) {
2739 if (open_pack_index(p))
2740 return 0;
2741 level1_ofs = p->index_data;
2742 index = p->index_data;
2743 }
74e34e1f
NP
2744 if (p->index_version > 1) {
2745 level1_ofs += 2;
2746 index += 8;
2747 }
42873078 2748 index += 4 * 256;
74e34e1f
NP
2749 hi = ntohl(level1_ofs[*sha1]);
2750 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2751 if (p->index_version > 1) {
2752 stride = 20;
2753 } else {
2754 stride = 24;
2755 index += 4;
2756 }
2757
2758 if (debug_lookup)
6e1c2344 2759 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2760 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2761
6355a768 2762 while (lo < hi) {
74e34e1f 2763 unsigned mi = (lo + hi) / 2;
628522ec
JH
2764 int cmp = hashcmp(index + mi * stride, sha1);
2765
2766 if (debug_lookup)
2767 printf("lo %u hi %u rg %u mi %u\n",
2768 lo, hi, hi - lo, mi);
43057304 2769 if (!cmp)
74e34e1f 2770 return nth_packed_object_offset(p, mi);
1f688557
JH
2771 if (cmp > 0)
2772 hi = mi;
2773 else
2774 lo = mi+1;
6355a768 2775 }
1f688557
JH
2776 return 0;
2777}
2778
4c080182 2779int is_pack_valid(struct packed_git *p)
d131b7af
SP
2780{
2781 /* An already open pack is known to be valid. */
2782 if (p->pack_fd != -1)
2783 return 1;
2784
2785 /* If the pack has one window completely covering the
2786 * file size, the pack is known to be valid even if
2787 * the descriptor is not currently open.
2788 */
2789 if (p->windows) {
2790 struct pack_window *w = p->windows;
2791
2792 if (!w->offset && w->len == p->pack_size)
2793 return 1;
2794 }
2795
2796 /* Force the pack to open to prove its valid. */
2797 return !open_packed_git(p);
2798}
2799
95099731
NTND
2800static int fill_pack_entry(const unsigned char *sha1,
2801 struct pack_entry *e,
2802 struct packed_git *p)
2803{
2804 off_t offset;
2805
2806 if (p->num_bad_objects) {
2807 unsigned i;
2808 for (i = 0; i < p->num_bad_objects; i++)
2809 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2810 return 0;
2811 }
2812
2813 offset = find_pack_entry_one(sha1, p);
2814 if (!offset)
2815 return 0;
2816
2817 /*
2818 * We are about to tell the caller where they can locate the
2819 * requested object. We better make sure the packfile is
2820 * still here and can be accessed before supplying that
2821 * answer, as it may have been deleted since the index was
2822 * loaded!
2823 */
319b678a 2824 if (!is_pack_valid(p))
95099731 2825 return 0;
95099731
NTND
2826 e->offset = offset;
2827 e->p = p;
2828 hashcpy(e->sha1, sha1);
2829 return 1;
2830}
2831
d40d535b
MH
2832/*
2833 * Iff a pack file contains the object named by sha1, return true and
2834 * store its location to e.
2835 */
4d6acb70 2836static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557 2837{
a73cdd21 2838 struct mru_entry *p;
43057304 2839
1f688557 2840 prepare_packed_git();
f7c22cc6
NP
2841 if (!packed_git)
2842 return 0;
1f688557 2843
a73cdd21
JK
2844 for (p = packed_git_mru->head; p; p = p->next) {
2845 if (fill_pack_entry(sha1, e, p->item)) {
2846 mru_mark(packed_git_mru, p);
1b1005d1
MH
2847 return 1;
2848 }
c01f51cc 2849 }
1f688557
JH
2850 return 0;
2851}
2852
a6080a0a 2853struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2854 struct packed_git *packs)
2855{
2856 struct packed_git *p;
bf592c50
DB
2857
2858 for (p = packs; p; p = p->next) {
43057304 2859 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2860 return p;
2861 }
2862 return NULL;
21666f1a 2863
bf592c50
DB
2864}
2865
052fe5ea 2866static int sha1_loose_object_info(const unsigned char *sha1,
46f03448
KN
2867 struct object_info *oi,
2868 int flags)
65c2e0c3 2869{
46f03448
KN
2870 int status = 0;
2871 unsigned long mapsize;
65c2e0c3 2872 void *map;
ef49a7a0 2873 git_zstream stream;
d65a16f6 2874 char hdr[32];
46f03448 2875 struct strbuf hdrbuf = STRBUF_INIT;
c84a1f3e 2876 unsigned long size_scratch;
65c2e0c3 2877
5d642e75
JK
2878 if (oi->delta_base_sha1)
2879 hashclr(oi->delta_base_sha1);
2880
052fe5ea
JK
2881 /*
2882 * If we don't care about type or size, then we don't
4ef8d1dd
JH
2883 * need to look inside the object at all. Note that we
2884 * do not optimize out the stat call, even if the
2885 * caller doesn't care about the disk-size, since our
2886 * return value implicitly indicates whether the
2887 * object even exists.
052fe5ea 2888 */
c84a1f3e 2889 if (!oi->typep && !oi->typename && !oi->sizep && !oi->contentp) {
771e7d57 2890 const char *path;
4ef8d1dd 2891 struct stat st;
771e7d57 2892 if (stat_sha1_file(sha1, &st, &path) < 0)
4ef8d1dd
JH
2893 return -1;
2894 if (oi->disk_sizep)
23c339c0 2895 *oi->disk_sizep = st.st_size;
052fe5ea
JK
2896 return 0;
2897 }
2898
bb6b8e4f 2899 map = map_sha1_file(sha1, &mapsize);
f0df4ed5 2900 if (!map)
dbea72a8 2901 return -1;
c84a1f3e
JT
2902
2903 if (!oi->sizep)
2904 oi->sizep = &size_scratch;
2905
23c339c0
JK
2906 if (oi->disk_sizep)
2907 *oi->disk_sizep = mapsize;
19fc5e84 2908 if ((flags & OBJECT_INFO_ALLOW_UNKNOWN_TYPE)) {
46f03448
KN
2909 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2910 status = error("unable to unpack %s header with --allow-unknown-type",
2911 sha1_to_hex(sha1));
2912 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
36e4d74a
JH
2913 status = error("unable to unpack %s header",
2914 sha1_to_hex(sha1));
46f03448
KN
2915 if (status < 0)
2916 ; /* Do nothing */
2917 else if (hdrbuf.len) {
2918 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2919 status = error("unable to parse %s header with --allow-unknown-type",
2920 sha1_to_hex(sha1));
2921 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
36e4d74a 2922 status = error("unable to parse %s header", sha1_to_hex(sha1));
c84a1f3e
JT
2923
2924 if (status >= 0 && oi->contentp)
2925 *oi->contentp = unpack_sha1_rest(&stream, hdr,
2926 *oi->sizep, sha1);
2927 else
2928 git_inflate_end(&stream);
2929
65c2e0c3 2930 munmap(map, mapsize);
46f03448 2931 if (status && oi->typep)
23c339c0 2932 *oi->typep = status;
c84a1f3e
JT
2933 if (oi->sizep == &size_scratch)
2934 oi->sizep = NULL;
46f03448 2935 strbuf_release(&hdrbuf);
3ab0fb06 2936 oi->whence = OI_LOOSE;
93cff9a9 2937 return (status < 0) ? status : 0;
65c2e0c3
JH
2938}
2939
de7b5d62 2940int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
f0df4ed5 2941{
cd585e2a 2942 static struct object_info blank_oi = OBJECT_INFO_INIT;
f0df4ed5 2943 struct pack_entry e;
5b086407 2944 int rtype;
1f0c0d36
JT
2945 const unsigned char *real = (flags & OBJECT_INFO_LOOKUP_REPLACE) ?
2946 lookup_replace_object(sha1) :
2947 sha1;
f0df4ed5 2948
cd585e2a
JT
2949 if (!oi)
2950 oi = &blank_oi;
2951
dfdd4afc
JT
2952 if (!(flags & OBJECT_INFO_SKIP_CACHED)) {
2953 struct cached_object *co = find_cached_object(real);
2954 if (co) {
2955 if (oi->typep)
2956 *(oi->typep) = co->type;
2957 if (oi->sizep)
2958 *(oi->sizep) = co->size;
2959 if (oi->disk_sizep)
2960 *(oi->disk_sizep) = 0;
2961 if (oi->delta_base_sha1)
2962 hashclr(oi->delta_base_sha1);
2963 if (oi->typename)
2964 strbuf_addstr(oi->typename, typename(co->type));
2965 if (oi->contentp)
2966 *oi->contentp = xmemdupz(co->buf, co->size);
2967 oi->whence = OI_CACHED;
2968 return 0;
2969 }
c4d9986f
NTND
2970 }
2971
1f7117ef 2972 if (!find_pack_entry(real, &e)) {
ddd63e64 2973 /* Most likely it's a loose object. */
3ab0fb06 2974 if (!sha1_loose_object_info(real, oi, flags))
5b086407 2975 return 0;
ddd63e64
SG
2976
2977 /* Not a loose object; someone else may have just packed it. */
dfdd4afc 2978 if (flags & OBJECT_INFO_QUICK) {
052fe5ea 2979 return -1;
dfdd4afc
JT
2980 } else {
2981 reprepare_packed_git();
2982 if (!find_pack_entry(real, &e))
2983 return -1;
2984 }
f0df4ed5 2985 }
3d77d877 2986
cd585e2a
JT
2987 if (oi == &blank_oi)
2988 /*
2989 * We know that the caller doesn't actually need the
2990 * information below, so return early.
2991 */
2992 return 0;
46f03448 2993
23c339c0 2994 rtype = packed_object_info(e.p, e.offset, oi);
412916ee 2995 if (rtype < 0) {
1f7117ef
CC
2996 mark_bad_packed_object(e.p, real);
2997 return sha1_object_info_extended(real, oi, 0);
3ab0fb06 2998 } else if (oi->whence == OI_PACKED) {
9a490590
JH
2999 oi->u.packed.offset = e.offset;
3000 oi->u.packed.pack = e.p;
3001 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
3002 rtype == OBJ_OFS_DELTA);
3d77d877
NP
3003 }
3004
5b086407 3005 return 0;
f0df4ed5
JS
3006}
3007
3fc0dca9 3008/* returns enum object_type or negative */
9a490590
JH
3009int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
3010{
5b086407 3011 enum object_type type;
27b5c1a0 3012 struct object_info oi = OBJECT_INFO_INIT;
9a490590 3013
5b086407 3014 oi.typep = &type;
9a490590 3015 oi.sizep = sizep;
1f0c0d36
JT
3016 if (sha1_object_info_extended(sha1, &oi,
3017 OBJECT_INFO_LOOKUP_REPLACE) < 0)
5b086407
JK
3018 return -1;
3019 return type;
9a490590
JH
3020}
3021
21666f1a
NP
3022int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
3023 unsigned char *sha1)
d66b37bb
JH
3024{
3025 struct cached_object *co;
3026
21666f1a 3027 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
3028 if (has_sha1_file(sha1) || find_cached_object(sha1))
3029 return 0;
c7353967 3030 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
d66b37bb
JH
3031 co = &cached_objects[cached_object_nr++];
3032 co->size = len;
21666f1a 3033 co->type = type;
efa13f7b
JH
3034 co->buf = xmalloc(len);
3035 memcpy(co->buf, buf, len);
d66b37bb
JH
3036 hashcpy(co->sha1, sha1);
3037 return 0;
3038}
3039
c2c5b270
CC
3040static void *read_object(const unsigned char *sha1, enum object_type *type,
3041 unsigned long *size)
0fcfd160 3042{
c84a1f3e
JT
3043 struct object_info oi = OBJECT_INFO_INIT;
3044 void *content;
3045 oi.typep = type;
3046 oi.sizep = size;
3047 oi.contentp = &content;
0fcfd160 3048
c84a1f3e
JT
3049 if (sha1_object_info_extended(sha1, &oi, 0) < 0)
3050 return NULL;
3051 return content;
0fcfd160
LT
3052}
3053
b6c4cecc
JH
3054/*
3055 * This function dies on corrupt objects; the callers who want to
3056 * deal with them should arrange to call read_object() and give error
3057 * messages themselves.
3058 */
5bf29b95
JH
3059void *read_sha1_file_extended(const unsigned char *sha1,
3060 enum object_type *type,
3061 unsigned long *size,
1f0c0d36 3062 int lookup_replace)
ac939109 3063{
3ba7a065 3064 void *data;
b6c4cecc 3065 const struct packed_git *p;
771e7d57
JK
3066 const char *path;
3067 struct stat st;
1f0c0d36
JT
3068 const unsigned char *repl = lookup_replace ? lookup_replace_object(sha1)
3069 : sha1;
b6c4cecc 3070
3ba7a065
JH
3071 errno = 0;
3072 data = read_object(repl, type, size);
4bbf5a26 3073 if (data)
b6c4cecc 3074 return data;
68095570 3075
25f3af3f 3076 if (errno && errno != ENOENT)
3ba7a065
JH
3077 die_errno("failed to read object %s", sha1_to_hex(sha1));
3078
68095570 3079 /* die if we replaced an object with one that does not exist */
b6c4cecc 3080 if (repl != sha1)
68095570
CC
3081 die("replacement %s not found for %s",
3082 sha1_to_hex(repl), sha1_to_hex(sha1));
3083
771e7d57 3084 if (!stat_sha1_file(repl, &st, &path))
b6c4cecc
JH
3085 die("loose object %s (stored in %s) is corrupt",
3086 sha1_to_hex(repl), path);
68095570 3087
b6c4cecc
JH
3088 if ((p = has_packed_and_bad(repl)) != NULL)
3089 die("packed object %s (stored in %s) is corrupt",
3090 sha1_to_hex(repl), p->pack_name);
f5552aee 3091
b6c4cecc 3092 return NULL;
ac939109
NP
3093}
3094
40469ee9 3095void *read_object_with_reference(const unsigned char *sha1,
21666f1a 3096 const char *required_type_name,
40469ee9
JH
3097 unsigned long *size,
3098 unsigned char *actual_sha1_return)
f4913f91 3099{
21666f1a 3100 enum object_type type, required_type;
f4913f91
JH
3101 void *buffer;
3102 unsigned long isize;
40469ee9 3103 unsigned char actual_sha1[20];
f4913f91 3104
21666f1a 3105 required_type = type_from_string(required_type_name);
e702496e 3106 hashcpy(actual_sha1, sha1);
40469ee9
JH
3107 while (1) {
3108 int ref_length = -1;
3109 const char *ref_type = NULL;
f4913f91 3110
21666f1a 3111 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
3112 if (!buffer)
3113 return NULL;
21666f1a 3114 if (type == required_type) {
40469ee9
JH
3115 *size = isize;
3116 if (actual_sha1_return)
e702496e 3117 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
3118 return buffer;
3119 }
3120 /* Handle references */
21666f1a 3121 else if (type == OBJ_COMMIT)
40469ee9 3122 ref_type = "tree ";
21666f1a 3123 else if (type == OBJ_TAG)
40469ee9
JH
3124 ref_type = "object ";
3125 else {
3126 free(buffer);
3127 return NULL;
3128 }
3129 ref_length = strlen(ref_type);
f4913f91 3130
50974ec9
MK
3131 if (ref_length + 40 > isize ||
3132 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 3133 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
3134 free(buffer);
3135 return NULL;
3136 }
1cf58e72 3137 free(buffer);
40469ee9
JH
3138 /* Now we have the ID of the referred-to object in
3139 * actual_sha1. Check again. */
f4913f91 3140 }
f4913f91
JH
3141}
3142
ce9fbf16 3143static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 3144 const char *type, unsigned char *sha1,
d65a16f6 3145 char *hdr, int *hdrlen)
d410c0f5 3146{
9126f009 3147 git_SHA_CTX c;
d410c0f5
JH
3148
3149 /* Generate the header */
ef1286d3 3150 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
d410c0f5
JH
3151
3152 /* Sha1.. */
9126f009
NP
3153 git_SHA1_Init(&c);
3154 git_SHA1_Update(&c, hdr, *hdrlen);
3155 git_SHA1_Update(&c, buf, len);
3156 git_SHA1_Final(sha1, &c);
d410c0f5
JH
3157}
3158
230f1322 3159/*
5a688fe4 3160 * Move the just written object into its final resting place.
230f1322 3161 */
cb5add58 3162int finalize_object_file(const char *tmpfile, const char *filename)
230f1322 3163{
e32c0a9c 3164 int ret = 0;
5a688fe4 3165
348df166 3166 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
3167 goto try_rename;
3168 else if (link(tmpfile, filename))
e32c0a9c 3169 ret = errno;
7ebb6fca
LT
3170
3171 /*
3172 * Coda hack - coda doesn't like cross-directory links,
3173 * so we fall back to a rename, which will mean that it
3174 * won't be able to check collisions, but that's not a
3175 * big deal.
3176 *
3177 * The same holds for FAT formatted media.
3178 *
3be1f18e 3179 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
3180 * left to unlink.
3181 */
3182 if (ret && ret != EEXIST) {
be66a6c4 3183 try_rename:
7ebb6fca 3184 if (!rename(tmpfile, filename))
3be1f18e 3185 goto out;
9e48b389 3186 ret = errno;
230f1322 3187 }
691f1a28 3188 unlink_or_warn(tmpfile);
230f1322
LT
3189 if (ret) {
3190 if (ret != EEXIST) {
7616c6ca 3191 return error_errno("unable to write sha1 filename %s", filename);
230f1322
LT
3192 }
3193 /* FIXME!!! Collision check here ? */
3194 }
3195
3be1f18e 3196out:
5256b006 3197 if (adjust_shared_perm(filename))
5a688fe4 3198 return error("unable to set permission to '%s'", filename);
230f1322
LT
3199 return 0;
3200}
3201
4d548150
LT
3202static int write_buffer(int fd, const void *buf, size_t len)
3203{
d34cf19b 3204 if (write_in_full(fd, buf, len) < 0)
7616c6ca 3205 return error_errno("file write error");
4d548150
LT
3206 return 0;
3207}
3208
ce9fbf16 3209int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
3210 unsigned char *sha1)
3211{
d65a16f6 3212 char hdr[32];
ef1286d3 3213 int hdrlen = sizeof(hdr);
abdc3fc8
RS
3214 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3215 return 0;
3216}
3217
e9039dd3
LT
3218/* Finalize a file on disk, and close it. */
3219static void close_sha1_file(int fd)
3220{
aafe9fba
LT
3221 if (fsync_object_files)
3222 fsync_or_die(fd, "sha1 file");
e9039dd3 3223 if (close(fd) != 0)
d824cbba 3224 die_errno("error when closing sha1 file");
e9039dd3
LT
3225}
3226
5723fe7e
LT
3227/* Size of directory component, including the ending '/' */
3228static inline int directory_size(const char *filename)
3229{
3230 const char *s = strrchr(filename, '/');
3231 if (!s)
3232 return 0;
3233 return s - filename + 1;
3234}
3235
3236/*
3237 * This creates a temporary file in the same directory as the final
3238 * 'filename'
3239 *
3240 * We want to avoid cross-directory filename renames, because those
3241 * can have problems on various filesystems (FAT, NFS, Coda).
3242 */
d4b3d11a 3243static int create_tmpfile(struct strbuf *tmp, const char *filename)
5723fe7e
LT
3244{
3245 int fd, dirlen = directory_size(filename);
3246
d4b3d11a
JK
3247 strbuf_reset(tmp);
3248 strbuf_add(tmp, filename, dirlen);
3249 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3250 fd = git_mkstemp_mode(tmp->buf, 0444);
cbacbf4e 3251 if (fd < 0 && dirlen && errno == ENOENT) {
d4b3d11a
JK
3252 /*
3253 * Make sure the directory exists; note that the contents
3254 * of the buffer are undefined after mkstemp returns an
3255 * error, so we have to rewrite the whole buffer from
3256 * scratch.
3257 */
3258 strbuf_reset(tmp);
3259 strbuf_add(tmp, filename, dirlen - 1);
3260 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
b2476a60 3261 return -1;
d4b3d11a 3262 if (adjust_shared_perm(tmp->buf))
5723fe7e
LT
3263 return -1;
3264
3265 /* Try again */
d4b3d11a
JK
3266 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3267 fd = git_mkstemp_mode(tmp->buf, 0444);
5723fe7e
LT
3268 }
3269 return fd;
3270}
3271
bbac7311 3272static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 3273 const void *buf, unsigned long len, time_t mtime)
0fcfd160 3274{
915308b1 3275 int fd, ret;
9892beba 3276 unsigned char compressed[4096];
ef49a7a0 3277 git_zstream stream;
748af44c
NP
3278 git_SHA_CTX c;
3279 unsigned char parano_sha1[20];
d4b3d11a 3280 static struct strbuf tmp_file = STRBUF_INIT;
30d6c6ea 3281 const char *filename = sha1_file_name(sha1);
a44c9a5e 3282
d4b3d11a 3283 fd = create_tmpfile(&tmp_file, filename);
aac17941 3284 if (fd < 0) {
35243577 3285 if (errno == EACCES)
82247e9b 3286 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 3287 else
7616c6ca 3288 return error_errno("unable to create temporary file");
aac17941
LT
3289 }
3290
0fcfd160 3291 /* Set it up */
55bb5c91 3292 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 3293 stream.next_out = compressed;
9892beba 3294 stream.avail_out = sizeof(compressed);
748af44c 3295 git_SHA1_Init(&c);
a44c9a5e
LT
3296
3297 /* First header.. */
d65a16f6 3298 stream.next_in = (unsigned char *)hdr;
a44c9a5e 3299 stream.avail_in = hdrlen;
55bb5c91
JH
3300 while (git_deflate(&stream, 0) == Z_OK)
3301 ; /* nothing */
748af44c 3302 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
3303
3304 /* Then the data itself.. */
c00e657d 3305 stream.next_in = (void *)buf;
a44c9a5e 3306 stream.avail_in = len;
9892beba 3307 do {
748af44c 3308 unsigned char *in0 = stream.next_in;
55bb5c91 3309 ret = git_deflate(&stream, Z_FINISH);
748af44c 3310 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
3311 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3312 die("unable to write sha1 file");
3313 stream.next_out = compressed;
3314 stream.avail_out = sizeof(compressed);
3315 } while (ret == Z_OK);
3316
ac54c277
LT
3317 if (ret != Z_STREAM_END)
3318 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 3319 ret = git_deflate_end_gently(&stream);
ac54c277
LT
3320 if (ret != Z_OK)
3321 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
3322 git_SHA1_Final(parano_sha1, &c);
3323 if (hashcmp(sha1, parano_sha1) != 0)
3324 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 3325
e9039dd3 3326 close_sha1_file(fd);
0fcfd160 3327
bbac7311
NP
3328 if (mtime) {
3329 struct utimbuf utb;
3330 utb.actime = mtime;
3331 utb.modtime = mtime;
d4b3d11a 3332 if (utime(tmp_file.buf, &utb) < 0)
7616c6ca 3333 warning_errno("failed utime() on %s", tmp_file.buf);
bbac7311
NP
3334 }
3335
d4b3d11a 3336 return finalize_object_file(tmp_file.buf, filename);
0fcfd160 3337}
8237b185 3338
33d4221c
JK
3339static int freshen_loose_object(const unsigned char *sha1)
3340{
3341 return check_and_freshen(sha1, 1);
3342}
3343
3344static int freshen_packed_object(const unsigned char *sha1)
3345{
3346 struct pack_entry e;
ee1c6c34
JK
3347 if (!find_pack_entry(sha1, &e))
3348 return 0;
3349 if (e.p->freshened)
3350 return 1;
3351 if (!freshen_file(e.p->pack_name))
3352 return 0;
3353 e.p->freshened = 1;
3354 return 1;
33d4221c
JK
3355}
3356
1427a7ff 3357int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
bbac7311 3358{
bbac7311 3359 char hdr[32];
ef1286d3 3360 int hdrlen = sizeof(hdr);
bbac7311
NP
3361
3362 /* Normally if we have it in the pack then we do not bother writing
3363 * it out into .git/objects/??/?{38} file.
3364 */
3365 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
b5f52f37 3366 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
bbac7311
NP
3367 return 0;
3368 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3369}
3370
0c3db67c
ES
3371int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3372 unsigned char *sha1, unsigned flags)
3373{
3374 char *header;
3375 int hdrlen, status = 0;
3376
3377 /* type string, SP, %lu of the length plus NUL must fit this */
ef1286d3
JK
3378 hdrlen = strlen(type) + 32;
3379 header = xmalloc(hdrlen);
0c3db67c
ES
3380 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3381
3382 if (!(flags & HASH_WRITE_OBJECT))
3383 goto cleanup;
051086b9 3384 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
0c3db67c
ES
3385 goto cleanup;
3386 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3387
3388cleanup:
3389 free(header);
3390 return status;
3391}
3392
bbac7311
NP
3393int force_object_loose(const unsigned char *sha1, time_t mtime)
3394{
bbac7311
NP
3395 void *buf;
3396 unsigned long len;
3397 enum object_type type;
3398 char hdr[32];
3399 int hdrlen;
1fb23e65 3400 int ret;
bbac7311 3401
c529d75a 3402 if (has_loose_object(sha1))
bbac7311 3403 return 0;
789bf26b 3404 buf = read_object(sha1, &type, &len);
bbac7311
NP
3405 if (!buf)
3406 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
ef1286d3 3407 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
1fb23e65
BS
3408 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3409 free(buf);
3410
3411 return ret;
bbac7311
NP
3412}
3413
bf592c50
DB
3414int has_pack_index(const unsigned char *sha1)
3415{
3416 struct stat st;
3417 if (stat(sha1_pack_index_name(sha1), &st))
3418 return 0;
3419 return 1;
bf592c50
DB
3420}
3421
cd673c1f
JH
3422int has_sha1_pack(const unsigned char *sha1)
3423{
3424 struct pack_entry e;
3425 return find_pack_entry(sha1, &e);
3426}
3427
0eeb077b 3428int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
8237b185 3429{
3e8b7d3c
JN
3430 if (!startup_info->have_repository)
3431 return 0;
e83e71c5
JT
3432 return sha1_object_info_extended(sha1, NULL,
3433 flags | OBJECT_INFO_SKIP_CACHED) >= 0;
b419aa25 3434}
3435
3436int has_object_file(const struct object_id *oid)
3437{
3438 return has_sha1_file(oid->hash);
8237b185 3439}
74400e71 3440
5827a035
JK
3441int has_object_file_with_flags(const struct object_id *oid, int flags)
3442{
3443 return has_sha1_file_with_flags(oid->hash, flags);
3444}
3445
c879daa2
NTND
3446static void check_tree(const void *buf, size_t size)
3447{
3448 struct tree_desc desc;
3449 struct name_entry entry;
3450
3451 init_tree_desc(&desc, buf, size);
3452 while (tree_entry(&desc, &entry))
3453 /* do nothing
3454 * tree_entry() will die() on malformed entries */
3455 ;
3456}
3457
3458static void check_commit(const void *buf, size_t size)
3459{
3460 struct commit c;
3461 memset(&c, 0, sizeof(c));
3462 if (parse_commit_buffer(&c, buf, size))
3463 die("corrupt commit");
3464}
3465
3466static void check_tag(const void *buf, size_t size)
3467{
3468 struct tag t;
3469 memset(&t, 0, sizeof(t));
3470 if (parse_tag_buffer(&t, buf, size))
3471 die("corrupt tag");
3472}
3473
43df4f86 3474static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
3475 enum object_type type,
3476 const char *path, unsigned flags)
e7332f96 3477{
6c510bee 3478 int ret, re_allocated = 0;
c4ce46fc 3479 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 3480
7672db20 3481 if (!type)
edaec3fb 3482 type = OBJ_BLOB;
6c510bee
LT
3483
3484 /*
3485 * Convert blobs to git internal format
3486 */
43df4f86 3487 if ((type == OBJ_BLOB) && path) {
f285a2d7 3488 struct strbuf nbuf = STRBUF_INIT;
82b474e0 3489 if (convert_to_git(&the_index, path, buf, size, &nbuf,
5e12e78e 3490 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 3491 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
3492 re_allocated = 1;
3493 }
3494 }
c4ce46fc 3495 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
3496 if (type == OBJ_TREE)
3497 check_tree(buf, size);
3498 if (type == OBJ_COMMIT)
3499 check_commit(buf, size);
3500 if (type == OBJ_TAG)
3501 check_tag(buf, size);
3502 }
6c510bee 3503
7672db20 3504 if (write_object)
edaec3fb 3505 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 3506 else
edaec3fb 3507 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 3508 if (re_allocated)
6c510bee 3509 free(buf);
43df4f86
DP
3510 return ret;
3511}
3512
9035d75a
SP
3513static int index_stream_convert_blob(unsigned char *sha1, int fd,
3514 const char *path, unsigned flags)
3515{
3516 int ret;
3517 const int write_object = flags & HASH_WRITE_OBJECT;
3518 struct strbuf sbuf = STRBUF_INIT;
3519
3520 assert(path);
3521 assert(would_convert_to_git_filter_fd(path));
3522
d6c41c20 3523 convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
9035d75a
SP
3524 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3525
3526 if (write_object)
3527 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3528 sha1);
3529 else
3530 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3531 sha1);
3532 strbuf_release(&sbuf);
3533 return ret;
3534}
3535
7b41e1e1
JH
3536static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3537 const char *path, unsigned flags)
3538{
3539 struct strbuf sbuf = STRBUF_INIT;
3540 int ret;
3541
3542 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3543 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3544 else
3545 ret = -1;
3546 strbuf_release(&sbuf);
3547 return ret;
3548}
3549
ea68b0ce
DP
3550#define SMALL_FILE_SIZE (32*1024)
3551
7b41e1e1
JH
3552static int index_core(unsigned char *sha1, int fd, size_t size,
3553 enum object_type type, const char *path,
3554 unsigned flags)
43df4f86
DP
3555{
3556 int ret;
43df4f86 3557
7b41e1e1 3558 if (!size) {
f6a1e1e2 3559 ret = index_mem(sha1, "", size, type, path, flags);
ea68b0ce
DP
3560 } else if (size <= SMALL_FILE_SIZE) {
3561 char *buf = xmalloc(size);
3562 if (size == read_in_full(fd, buf, size))
c4ce46fc 3563 ret = index_mem(sha1, buf, size, type, path, flags);
ea68b0ce 3564 else
7616c6ca 3565 ret = error_errno("short read");
ea68b0ce 3566 free(buf);
08bda208 3567 } else {