sha1_file: release delta_stack on error in unpack_entry()
[git/git.git] / sha1_file.c
CommitLineData
0fcfd160
LT
1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
0fcfd160 9#include "cache.h"
6eac50d8 10#include "string-list.h"
697cc8ef 11#include "lockfile.h"
1f688557 12#include "delta.h"
a733cb60 13#include "pack.h"
8e440259
PE
14#include "blob.h"
15#include "commit.h"
4dd1fbc7 16#include "run-command.h"
8e440259
PE
17#include "tag.h"
18#include "tree.h"
c879daa2 19#include "tree-walk.h"
f35a6d3b 20#include "refs.h"
70f5d5d3 21#include "pack-revindex.h"
628522ec 22#include "sha1-lookup.h"
568508e7 23#include "bulk-checkin.h"
090ea126 24#include "streaming.h"
543c5caa 25#include "dir.h"
a73cdd21 26#include "mru.h"
12d95ef6 27#include "list.h"
c4c6effa 28#include "mergesort.h"
cf3c6352 29#include "quote.h"
0fcfd160 30
28bd70d8
JN
31#define SZ_FMT PRIuMAX
32static inline uintmax_t sz_fmt(size_t s) { return s; }
e05db0fd 33
96f1e58f 34const unsigned char null_sha1[20];
3e56e724 35const struct object_id null_oid;
8576fde6
JK
36const struct object_id empty_tree_oid = {
37 EMPTY_TREE_SHA1_BIN_LITERAL
38};
39const struct object_id empty_blob_oid = {
40 EMPTY_BLOB_SHA1_BIN_LITERAL
41};
88cd621d 42
c597ba80
NTND
43/*
44 * This is meant to hold a *small* number of objects that you would
45 * want read_sha1_file() to be able to return, but yet you do not want
46 * to write them into the object store (e.g. a browse-only
47 * application).
48 */
49static struct cached_object {
50 unsigned char sha1[20];
51 enum object_type type;
52 void *buf;
53 unsigned long size;
54} *cached_objects;
55static int cached_object_nr, cached_object_alloc;
56
57static struct cached_object empty_tree = {
dab0d410 58 EMPTY_TREE_SHA1_BIN_LITERAL,
c597ba80
NTND
59 OBJ_TREE,
60 "",
61 0
62};
63
64static struct cached_object *find_cached_object(const unsigned char *sha1)
65{
66 int i;
67 struct cached_object *co = cached_objects;
68
69 for (i = 0; i < cached_object_nr; i++, co++) {
70 if (!hashcmp(co->sha1, sha1))
71 return co;
72 }
73 if (!hashcmp(sha1, empty_tree.sha1))
74 return &empty_tree;
75 return NULL;
76}
77
90a6464b
JH
78int mkdir_in_gitdir(const char *path)
79{
80 if (mkdir(path, 0777)) {
81 int saved_errno = errno;
82 struct stat st;
83 struct strbuf sb = STRBUF_INIT;
84
85 if (errno != EEXIST)
86 return -1;
87 /*
88 * Are we looking at a path in a symlinked worktree
89 * whose original repository does not yet have it?
90 * e.g. .git/rr-cache pointing at its original
91 * repository in which the user hasn't performed any
92 * conflict resolution yet?
93 */
94 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
95 strbuf_readlink(&sb, path, st.st_size) ||
96 !is_absolute_path(sb.buf) ||
97 mkdir(sb.buf, 0777)) {
98 strbuf_release(&sb);
99 errno = saved_errno;
100 return -1;
101 }
102 strbuf_release(&sb);
103 }
104 return adjust_shared_perm(path);
105}
106
0be0521b 107enum scld_error safe_create_leading_directories(char *path)
b2cb9425 108{
26c8ae2a 109 char *next_component = path + offset_1st_component(path);
0be0521b 110 enum scld_error ret = SCLD_OK;
67d42212 111
0be0521b 112 while (ret == SCLD_OK && next_component) {
f0502332 113 struct stat st;
0f527403 114 char *slash = next_component, slash_character;
f0502332 115
0f527403
MH
116 while (*slash && !is_dir_sep(*slash))
117 slash++;
118
119 if (!*slash)
b2cb9425 120 break;
bf10cf70 121
26c8ae2a 122 next_component = slash + 1;
0f527403 123 while (is_dir_sep(*next_component))
bf10cf70 124 next_component++;
26c8ae2a 125 if (!*next_component)
5f0bdf50 126 break;
831651fd 127
0f527403 128 slash_character = *slash;
831651fd 129 *slash = '\0';
67d42212
JR
130 if (!stat(path, &st)) {
131 /* path exists */
9e6f885d 132 if (!S_ISDIR(st.st_mode))
0be0521b 133 ret = SCLD_EXISTS;
53a39721 134 } else if (mkdir(path, 0777)) {
928734d9 135 if (errno == EEXIST &&
9e6f885d 136 !stat(path, &st) && S_ISDIR(st.st_mode))
928734d9 137 ; /* somebody created it since we checked */
18d37e86
MH
138 else if (errno == ENOENT)
139 /*
140 * Either mkdir() failed because
141 * somebody just pruned the containing
142 * directory, or stat() failed because
143 * the file that was in our way was
144 * just removed. Either way, inform
145 * the caller that it might be worth
146 * trying again:
147 */
148 ret = SCLD_VANISHED;
9e6f885d 149 else
0be0521b 150 ret = SCLD_FAILED;
53a39721 151 } else if (adjust_shared_perm(path)) {
0be0521b 152 ret = SCLD_PERMS;
457f06d6 153 }
0f527403 154 *slash = slash_character;
b2cb9425 155 }
9e6f885d 156 return ret;
b2cb9425 157}
723c31fe 158
0be0521b 159enum scld_error safe_create_leading_directories_const(const char *path)
8e21d63b
JK
160{
161 /* path points to cache entries, so xstrdup before messing with it */
162 char *buf = xstrdup(path);
0be0521b 163 enum scld_error result = safe_create_leading_directories(buf);
8e21d63b
JK
164 free(buf);
165 return result;
166}
167
f7b7774f 168static void fill_sha1_path(struct strbuf *buf, const unsigned char *sha1)
ace1534d
JH
169{
170 int i;
171 for (i = 0; i < 20; i++) {
172 static char hex[] = "0123456789abcdef";
173 unsigned int val = sha1[i];
f7b7774f
JK
174 strbuf_addch(buf, hex[val >> 4]);
175 strbuf_addch(buf, hex[val & 0xf]);
afbba2f0 176 if (!i)
f7b7774f 177 strbuf_addch(buf, '/');
ace1534d
JH
178 }
179}
180
30d6c6ea 181const char *sha1_file_name(const unsigned char *sha1)
0fcfd160 182{
f7b7774f 183 static struct strbuf buf = STRBUF_INIT;
0fcfd160 184
f7b7774f
JK
185 strbuf_reset(&buf);
186 strbuf_addf(&buf, "%s/", get_object_directory());
560fb6a1 187
f7b7774f
JK
188 fill_sha1_path(&buf, sha1);
189 return buf.buf;
0fcfd160
LT
190}
191
38dbe5f0
JK
192struct strbuf *alt_scratch_buf(struct alternate_object_database *alt)
193{
194 strbuf_setlen(&alt->scratch, alt->base_len);
195 return &alt->scratch;
196}
197
29ec6af2
JK
198static const char *alt_sha1_path(struct alternate_object_database *alt,
199 const unsigned char *sha1)
200{
38dbe5f0 201 struct strbuf *buf = alt_scratch_buf(alt);
f7b7774f 202 fill_sha1_path(buf, sha1);
38dbe5f0 203 return buf->buf;
0fcfd160
LT
204}
205
1cec8c63
JK
206 char *odb_pack_name(struct strbuf *buf,
207 const unsigned char *sha1,
208 const char *ext)
bf592c50 209{
ac5190cc
JK
210 strbuf_reset(buf);
211 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
1cec8c63 212 sha1_to_hex(sha1), ext);
ac5190cc 213 return buf->buf;
bf592c50
DB
214}
215
633f43e1 216char *sha1_pack_name(const unsigned char *sha1)
bf592c50 217{
ac5190cc 218 static struct strbuf buf = STRBUF_INIT;
1cec8c63 219 return odb_pack_name(&buf, sha1, "pack");
633f43e1 220}
bf592c50 221
633f43e1
HO
222char *sha1_pack_index_name(const unsigned char *sha1)
223{
ac5190cc 224 static struct strbuf buf = STRBUF_INIT;
1cec8c63 225 return odb_pack_name(&buf, sha1, "idx");
bf592c50
DB
226}
227
d5a63b99
JH
228struct alternate_object_database *alt_odb_list;
229static struct alternate_object_database **alt_odb_tail;
ace1534d 230
4ea82473
JK
231/*
232 * Return non-zero iff the path is usable as an alternate object database.
233 */
234static int alt_odb_usable(struct strbuf *path, const char *normalized_objdir)
235{
236 struct alternate_object_database *alt;
237
238 /* Detect cases where alternate disappeared */
239 if (!is_directory(path->buf)) {
240 error("object directory %s does not exist; "
241 "check .git/objects/info/alternates.",
242 path->buf);
243 return 0;
244 }
245
246 /*
247 * Prevent the common mistake of listing the same
248 * thing twice, or object directory itself.
249 */
250 for (alt = alt_odb_list; alt; alt = alt->next) {
ea0fc3b4 251 if (!fspathcmp(path->buf, alt->path))
4ea82473
JK
252 return 0;
253 }
254 if (!fspathcmp(path->buf, normalized_objdir))
255 return 0;
256
257 return 1;
258}
259
ddd5d056
JH
260/*
261 * Prepare alternate object database registry.
d5a63b99
JH
262 *
263 * The variable alt_odb_list points at the list of struct
264 * alternate_object_database. The elements on this list come from
265 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
266 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
267 * whose contents is similar to that environment variable but can be
268 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
269 * contains "/the/directory/corresponding/to/.git/objects/...", while
270 * its name points just after the slash at the end of ".git/objects/"
271 * in the example above, and has enough space to hold 40-byte hex
272 * SHA1, an extra slash for the first level indirection, and the
273 * terminating NUL.
ddd5d056 274 */
539e7506
EK
275static int link_alt_odb_entry(const char *entry, const char *relative_base,
276 int depth, const char *normalized_objdir)
ace1534d 277{
c2f493a4 278 struct alternate_object_database *ent;
5bdf0a84 279 struct strbuf pathbuf = STRBUF_INIT;
d5a63b99 280
85dadc38 281 if (!is_absolute_path(entry) && relative_base) {
4ac9006f 282 strbuf_realpath(&pathbuf, relative_base, 1);
5bdf0a84 283 strbuf_addch(&pathbuf, '/');
c2f493a4 284 }
6eac50d8 285 strbuf_addstr(&pathbuf, entry);
c2f493a4 286
37a95862 287 if (strbuf_normalize_path(&pathbuf) < 0 && relative_base) {
670c359d
JK
288 error("unable to normalize alternate object path: %s",
289 pathbuf.buf);
290 strbuf_release(&pathbuf);
291 return -1;
292 }
5bdf0a84
HW
293
294 /*
295 * The trailing slash after the directory name is given by
296 * this function at the end. Remove duplicates.
297 */
4ea82473
JK
298 while (pathbuf.len && pathbuf.buf[pathbuf.len - 1] == '/')
299 strbuf_setlen(&pathbuf, pathbuf.len - 1);
5bdf0a84 300
4ea82473
JK
301 if (!alt_odb_usable(&pathbuf, normalized_objdir)) {
302 strbuf_release(&pathbuf);
c2f493a4
MW
303 return -1;
304 }
305
7f0fa2c0 306 ent = alloc_alt_odb(pathbuf.buf);
c2f493a4
MW
307
308 /* add the alternate entry */
309 *alt_odb_tail = ent;
310 alt_odb_tail = &(ent->next);
311 ent->next = NULL;
312
313 /* recursively add alternates */
4ea82473 314 read_info_alternates(pathbuf.buf, depth + 1);
c2f493a4 315
4ea82473 316 strbuf_release(&pathbuf);
c2f493a4
MW
317 return 0;
318}
319
cf3c6352
JK
320static const char *parse_alt_odb_entry(const char *string,
321 int sep,
322 struct strbuf *out)
323{
324 const char *end;
325
326 strbuf_reset(out);
327
328 if (*string == '#') {
329 /* comment; consume up to next separator */
330 end = strchrnul(string, sep);
331 } else if (*string == '"' && !unquote_c_style(out, string, &end)) {
332 /*
333 * quoted path; unquote_c_style has copied the
334 * data for us and set "end". Broken quoting (e.g.,
335 * an entry that doesn't end with a quote) falls
336 * back to the unquoted case below.
337 */
338 } else {
339 /* normal, unquoted path */
340 end = strchrnul(string, sep);
341 strbuf_add(out, string, end - string);
342 }
343
344 if (*end)
345 end++;
346 return end;
347}
348
c5950164 349static void link_alt_odb_entries(const char *alt, int len, int sep,
c2f493a4
MW
350 const char *relative_base, int depth)
351{
539e7506 352 struct strbuf objdirbuf = STRBUF_INIT;
cf3c6352 353 struct strbuf entry = STRBUF_INIT;
c2f493a4
MW
354
355 if (depth > 5) {
356 error("%s: ignoring alternate object stores, nesting too deep.",
357 relative_base);
358 return;
359 }
360
f655651e 361 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
670c359d
JK
362 if (strbuf_normalize_path(&objdirbuf) < 0)
363 die("unable to normalize object directory: %s",
364 objdirbuf.buf);
539e7506 365
cf3c6352
JK
366 while (*alt) {
367 alt = parse_alt_odb_entry(alt, sep, &entry);
368 if (!entry.len)
9577e7e3 369 continue;
cf3c6352 370 link_alt_odb_entry(entry.buf, relative_base, depth, objdirbuf.buf);
9577e7e3 371 }
cf3c6352 372 strbuf_release(&entry);
539e7506 373 strbuf_release(&objdirbuf);
d5a63b99
JH
374}
375
5e73633d 376void read_info_alternates(const char * relative_base, int depth)
d5a63b99 377{
9577e7e3 378 char *map;
dc49cd76 379 size_t mapsz;
d5a63b99 380 struct stat st;
5015f01c 381 char *path;
c2f493a4 382 int fd;
d5a63b99 383
5015f01c 384 path = xstrfmt("%s/info/alternates", relative_base);
a5436b57 385 fd = git_open(path);
5015f01c 386 free(path);
d5a63b99
JH
387 if (fd < 0)
388 return;
389 if (fstat(fd, &st) || (st.st_size == 0)) {
390 close(fd);
9a217f2a 391 return;
ace1534d 392 }
dc49cd76
SP
393 mapsz = xsize_t(st.st_size);
394 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 395 close(fd);
d5a63b99 396
c5950164 397 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
c2f493a4 398
dc49cd76 399 munmap(map, mapsz);
ace1534d
JH
400}
401
7f0fa2c0
JK
402struct alternate_object_database *alloc_alt_odb(const char *dir)
403{
404 struct alternate_object_database *ent;
7f0fa2c0 405
597f9134 406 FLEX_ALLOC_STR(ent, path, dir);
38dbe5f0
JK
407 strbuf_init(&ent->scratch, 0);
408 strbuf_addf(&ent->scratch, "%s/", dir);
409 ent->base_len = ent->scratch.len;
7f0fa2c0
JK
410
411 return ent;
412}
413
bef70b22
DB
414void add_to_alternates_file(const char *reference)
415{
416 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
77b9b1d1
JK
417 char *alts = git_pathdup("objects/info/alternates");
418 FILE *in, *out;
419
420 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
421 out = fdopen_lock_file(lock, "w");
422 if (!out)
423 die_errno("unable to fdopen alternates lockfile");
424
425 in = fopen(alts, "r");
426 if (in) {
427 struct strbuf line = STRBUF_INIT;
428 int found = 0;
429
3f163962 430 while (strbuf_getline(&line, in) != EOF) {
77b9b1d1
JK
431 if (!strcmp(reference, line.buf)) {
432 found = 1;
433 break;
434 }
435 fprintf_or_die(out, "%s\n", line.buf);
436 }
437
438 strbuf_release(&line);
439 fclose(in);
440
441 if (found) {
442 rollback_lock_file(lock);
443 lock = NULL;
444 }
445 }
446 else if (errno != ENOENT)
447 die_errno("unable to read alternates file");
448
449 if (lock) {
450 fprintf_or_die(out, "%s\n", reference);
451 if (commit_lock_file(lock))
452 die_errno("unable to move new alternates file into place");
453 if (alt_odb_tail)
454 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
455 }
456 free(alts);
bef70b22
DB
457}
458
a5b34d21
JK
459void add_to_alternates_memory(const char *reference)
460{
461 /*
462 * Make sure alternates are initialized, or else our entry may be
463 * overwritten when they are.
464 */
465 prepare_alt_odb();
466
467 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
468}
469
9eeea7d2
SB
470/*
471 * Compute the exact path an alternate is at and returns it. In case of
472 * error NULL is returned and the human readable error is added to `err`
473 * `path` may be relative and should point to $GITDIR.
474 * `err` must not be null.
475 */
476char *compute_alternate_path(const char *path, struct strbuf *err)
477{
478 char *ref_git = NULL;
479 const char *repo, *ref_git_s;
480 int seen_error = 0;
481
482 ref_git_s = real_path_if_valid(path);
483 if (!ref_git_s) {
484 seen_error = 1;
485 strbuf_addf(err, _("path '%s' does not exist"), path);
486 goto out;
487 } else
488 /*
489 * Beware: read_gitfile(), real_path() and mkpath()
490 * return static buffer
491 */
492 ref_git = xstrdup(ref_git_s);
493
494 repo = read_gitfile(ref_git);
495 if (!repo)
496 repo = read_gitfile(mkpath("%s/.git", ref_git));
497 if (repo) {
498 free(ref_git);
499 ref_git = xstrdup(repo);
500 }
501
502 if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
503 char *ref_git_git = mkpathdup("%s/.git", ref_git);
504 free(ref_git);
505 ref_git = ref_git_git;
506 } else if (!is_directory(mkpath("%s/objects", ref_git))) {
507 struct strbuf sb = STRBUF_INIT;
508 seen_error = 1;
509 if (get_common_dir(&sb, ref_git)) {
510 strbuf_addf(err,
511 _("reference repository '%s' as a linked "
512 "checkout is not supported yet."),
513 path);
514 goto out;
515 }
516
517 strbuf_addf(err, _("reference repository '%s' is not a "
518 "local repository."), path);
519 goto out;
520 }
521
522 if (!access(mkpath("%s/shallow", ref_git), F_OK)) {
523 strbuf_addf(err, _("reference repository '%s' is shallow"),
524 path);
525 seen_error = 1;
526 goto out;
527 }
528
529 if (!access(mkpath("%s/info/grafts", ref_git), F_OK)) {
530 strbuf_addf(err,
531 _("reference repository '%s' is grafted"),
532 path);
533 seen_error = 1;
534 goto out;
535 }
536
537out:
538 if (seen_error) {
539 free(ref_git);
540 ref_git = NULL;
541 }
542
543 return ref_git;
544}
545
fe1b2268 546int foreach_alt_odb(alt_odb_fn fn, void *cb)
d79796bc
JH
547{
548 struct alternate_object_database *ent;
fe1b2268 549 int r = 0;
d79796bc
JH
550
551 prepare_alt_odb();
fe1b2268
JK
552 for (ent = alt_odb_list; ent; ent = ent->next) {
553 r = fn(ent, cb);
554 if (r)
555 break;
556 }
557 return r;
d79796bc
JH
558}
559
c2f493a4
MW
560void prepare_alt_odb(void)
561{
554fe20d 562 const char *alt;
c2f493a4 563
7dc24aa5
SP
564 if (alt_odb_tail)
565 return;
566
c2f493a4
MW
567 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
568 if (!alt) alt = "";
569
c2f493a4 570 alt_odb_tail = &alt_odb_list;
c5950164 571 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
572
573 read_info_alternates(get_object_directory(), 0);
574}
575
3096b2ec 576/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
33d4221c 577static int freshen_file(const char *fn)
ace1534d 578{
33d4221c
JK
579 struct utimbuf t;
580 t.actime = t.modtime = time(NULL);
581 return !utime(fn, &t);
0f4dc14a 582}
ace1534d 583
3096b2ec
JK
584/*
585 * All of the check_and_freshen functions return 1 if the file exists and was
586 * freshened (if freshening was requested), 0 otherwise. If they return
587 * 0, you should not assume that it is safe to skip a write of the object (it
588 * either does not exist on disk, or has a stale mtime and may be subject to
589 * pruning).
590 */
33d4221c
JK
591static int check_and_freshen_file(const char *fn, int freshen)
592{
593 if (access(fn, F_OK))
594 return 0;
3096b2ec 595 if (freshen && !freshen_file(fn))
33d4221c
JK
596 return 0;
597 return 1;
598}
599
600static int check_and_freshen_local(const unsigned char *sha1, int freshen)
601{
602 return check_and_freshen_file(sha1_file_name(sha1), freshen);
603}
604
605static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
0f4dc14a
BC
606{
607 struct alternate_object_database *alt;
9a217f2a 608 prepare_alt_odb();
d5a63b99 609 for (alt = alt_odb_list; alt; alt = alt->next) {
29ec6af2
JK
610 const char *path = alt_sha1_path(alt, sha1);
611 if (check_and_freshen_file(path, freshen))
c529d75a 612 return 1;
ace1534d 613 }
c529d75a 614 return 0;
ace1534d
JH
615}
616
33d4221c
JK
617static int check_and_freshen(const unsigned char *sha1, int freshen)
618{
619 return check_and_freshen_local(sha1, freshen) ||
620 check_and_freshen_nonlocal(sha1, freshen);
621}
622
623int has_loose_object_nonlocal(const unsigned char *sha1)
624{
625 return check_and_freshen_nonlocal(sha1, 0);
626}
627
0f4dc14a
BC
628static int has_loose_object(const unsigned char *sha1)
629{
33d4221c 630 return check_and_freshen(sha1, 0);
0f4dc14a
BC
631}
632
60bb8b14 633static unsigned int pack_used_ctr;
a53128b6
SP
634static unsigned int pack_mmap_calls;
635static unsigned int peak_pack_open_windows;
636static unsigned int pack_open_windows;
c7934306
SP
637static unsigned int pack_open_fds;
638static unsigned int pack_max_fds;
a53128b6 639static size_t peak_pack_mapped;
60bb8b14 640static size_t pack_mapped;
9a217f2a 641struct packed_git *packed_git;
1f688557 642
a73cdd21
JK
643static struct mru packed_git_mru_storage;
644struct mru *packed_git_mru = &packed_git_mru_storage;
645
b79d18c9 646void pack_report(void)
a53128b6
SP
647{
648 fprintf(stderr,
e05db0fd
PR
649 "pack_report: getpagesize() = %10" SZ_FMT "\n"
650 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
651 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
652 sz_fmt(getpagesize()),
653 sz_fmt(packed_git_window_size),
654 sz_fmt(packed_git_limit));
a53128b6
SP
655 fprintf(stderr,
656 "pack_report: pack_used_ctr = %10u\n"
657 "pack_report: pack_mmap_calls = %10u\n"
658 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
659 "pack_report: pack_mapped = "
660 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
661 pack_used_ctr,
662 pack_mmap_calls,
663 pack_open_windows, peak_pack_open_windows,
9e42d6a1 664 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
665}
666
d40d535b
MH
667/*
668 * Open and mmap the index file at path, perform a couple of
669 * consistency checks, then record its information to p. Return 0 on
670 * success.
671 */
672static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
673{
674 void *idx_map;
42873078 675 struct pack_idx_header *hdr;
dc49cd76 676 size_t idx_size;
74e34e1f 677 uint32_t version, nr, i, *index;
a5436b57 678 int fd = git_open(path);
1f688557 679 struct stat st;
42873078 680
1f688557
JH
681 if (fd < 0)
682 return -1;
683 if (fstat(fd, &st)) {
684 close(fd);
685 return -1;
686 }
dc49cd76 687 idx_size = xsize_t(st.st_size);
2d88451b
SP
688 if (idx_size < 4 * 256 + 20 + 20) {
689 close(fd);
690 return error("index file %s is too small", path);
691 }
c4712e45 692 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 693 close(fd);
1f688557 694
42873078
NP
695 hdr = idx_map;
696 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
697 version = ntohl(hdr->idx_version);
698 if (version < 2 || version > 2) {
699 munmap(idx_map, idx_size);
6e1c2344 700 return error("index file %s is version %"PRIu32
74e34e1f
NP
701 " and is not supported by this binary"
702 " (try upgrading GIT to a newer version)",
703 path, version);
704 }
705 } else
706 version = 1;
df1b059d 707
1f688557 708 nr = 0;
42873078 709 index = idx_map;
74e34e1f
NP
710 if (version > 1)
711 index += 2; /* skip index header */
1f688557 712 for (i = 0; i < 256; i++) {
326bf396 713 uint32_t n = ntohl(index[i]);
2d88451b
SP
714 if (n < nr) {
715 munmap(idx_map, idx_size);
df1b059d 716 return error("non-monotonic index %s", path);
2d88451b 717 }
1f688557
JH
718 nr = n;
719 }
720
74e34e1f
NP
721 if (version == 1) {
722 /*
723 * Total size:
724 * - 256 index entries 4 bytes each
725 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
726 * - 20-byte SHA1 of the packfile
727 * - 20-byte SHA1 file checksum
728 */
729 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
730 munmap(idx_map, idx_size);
eef427a0 731 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
732 }
733 } else if (version == 2) {
734 /*
735 * Minimum size:
736 * - 8 bytes of header
737 * - 256 index entries 4 bytes each
738 * - 20-byte sha1 entry * nr
739 * - 4-byte crc entry * nr
740 * - 4-byte offset entry * nr
741 * - 20-byte SHA1 of the packfile
742 * - 20-byte SHA1 file checksum
743 * And after the 4-byte offset table might be a
744 * variable sized table containing 8-byte entries
745 * for offsets larger than 2^31.
746 */
747 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
748 unsigned long max_size = min_size;
749 if (nr)
750 max_size += (nr - 1)*8;
751 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 752 munmap(idx_map, idx_size);
eef427a0 753 return error("wrong index v2 file size in %s", path);
74e34e1f 754 }
7109c889
JH
755 if (idx_size != min_size &&
756 /*
757 * make sure we can deal with large pack offsets.
758 * 31-bit signed offset won't be enough, neither
759 * 32-bit unsigned one will be.
760 */
761 (sizeof(off_t) <= 4)) {
762 munmap(idx_map, idx_size);
763 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 764 }
2d88451b 765 }
1f688557 766
74e34e1f 767 p->index_version = version;
42873078
NP
768 p->index_data = idx_map;
769 p->index_size = idx_size;
57059091 770 p->num_objects = nr;
1f688557
JH
771 return 0;
772}
773
bc8e478a 774int open_pack_index(struct packed_git *p)
d079837e
SP
775{
776 char *idx_name;
9ae97018 777 size_t len;
d079837e
SP
778 int ret;
779
780 if (p->index_data)
781 return 0;
782
9ae97018
JK
783 if (!strip_suffix(p->pack_name, ".pack", &len))
784 die("BUG: pack_name does not end in .pack");
785 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
d079837e
SP
786 ret = check_packed_git_idx(idx_name, p);
787 free(idx_name);
788 return ret;
789}
790
11daf39b
SP
791static void scan_windows(struct packed_git *p,
792 struct packed_git **lru_p,
793 struct pack_window **lru_w,
794 struct pack_window **lru_l)
1f688557 795{
11daf39b
SP
796 struct pack_window *w, *w_l;
797
798 for (w_l = NULL, w = p->windows; w; w = w->next) {
799 if (!w->inuse_cnt) {
800 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
801 *lru_p = p;
802 *lru_w = w;
803 *lru_l = w_l;
54044bf8 804 }
54044bf8 805 }
11daf39b 806 w_l = w;
f9253394 807 }
11daf39b
SP
808}
809
7c3ecb32 810static int unuse_one_window(struct packed_git *current)
11daf39b
SP
811{
812 struct packed_git *p, *lru_p = NULL;
813 struct pack_window *lru_w = NULL, *lru_l = NULL;
814
815 if (current)
816 scan_windows(current, &lru_p, &lru_w, &lru_l);
817 for (p = packed_git; p; p = p->next)
818 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
819 if (lru_p) {
820 munmap(lru_w->base, lru_w->len);
821 pack_mapped -= lru_w->len;
822 if (lru_l)
823 lru_l->next = lru_w->next;
7c3ecb32 824 else
54044bf8 825 lru_p->windows = lru_w->next;
54044bf8 826 free(lru_w);
a53128b6 827 pack_open_windows--;
54044bf8
SP
828 return 1;
829 }
830 return 0;
f9253394
JH
831}
832
7c3ecb32 833void release_pack_memory(size_t need)
97bfeb34
SP
834{
835 size_t cur = pack_mapped;
7c3ecb32 836 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
97bfeb34
SP
837 ; /* nothing */
838}
839
02710228
SP
840static void mmap_limit_check(size_t length)
841{
842 static size_t limit = 0;
843 if (!limit) {
844 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
845 if (!limit)
846 limit = SIZE_MAX;
847 }
848 if (length > limit)
849 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
850 (uintmax_t)length, (uintmax_t)limit);
851}
852
1570856b
JK
853void *xmmap_gently(void *start, size_t length,
854 int prot, int flags, int fd, off_t offset)
58ecbd5e 855{
02710228
SP
856 void *ret;
857
858 mmap_limit_check(length);
859 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
860 if (ret == MAP_FAILED) {
861 if (!length)
862 return NULL;
7c3ecb32 863 release_pack_memory(length);
58ecbd5e 864 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
865 }
866 return ret;
867}
868
1570856b
JK
869void *xmmap(void *start, size_t length,
870 int prot, int flags, int fd, off_t offset)
871{
872 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
873 if (ret == MAP_FAILED)
9ca0aaf6 874 die_errno("mmap failed");
1570856b
JK
875 return ret;
876}
877
c9ced051
SP
878void close_pack_windows(struct packed_git *p)
879{
880 while (p->windows) {
881 struct pack_window *w = p->windows;
882
883 if (w->inuse_cnt)
884 die("pack '%s' still has open windows to it",
885 p->pack_name);
886 munmap(w->base, w->len);
887 pack_mapped -= w->len;
888 pack_open_windows--;
889 p->windows = w->next;
890 free(w);
891 }
892}
893
71fe5d7f
JS
894static int close_pack_fd(struct packed_git *p)
895{
896 if (p->pack_fd < 0)
897 return 0;
898
899 close(p->pack_fd);
900 pack_open_fds--;
901 p->pack_fd = -1;
902
903 return 1;
904}
905
38849a81
JS
906static void close_pack(struct packed_git *p)
907{
908 close_pack_windows(p);
909 close_pack_fd(p);
910 close_pack_index(p);
911}
912
913void close_all_packs(void)
914{
915 struct packed_git *p;
916
917 for (p = packed_git; p; p = p->next)
918 if (p->do_not_close)
ef1177d1 919 die("BUG: want to close pack marked 'do-not-close'");
38849a81
JS
920 else
921 close_pack(p);
922}
923
924
88d0db55
BC
925/*
926 * The LRU pack is the one with the oldest MRU window, preferring packs
927 * with no used windows, or the oldest mtime if it has no windows allocated.
928 */
929static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
930{
931 struct pack_window *w, *this_mru_w;
932 int has_windows_inuse = 0;
933
934 /*
935 * Reject this pack if it has windows and the previously selected
936 * one does not. If this pack does not have windows, reject
937 * it if the pack file is newer than the previously selected one.
938 */
939 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
940 return;
941
942 for (w = this_mru_w = p->windows; w; w = w->next) {
943 /*
944 * Reject this pack if any of its windows are in use,
945 * but the previously selected pack did not have any
946 * inuse windows. Otherwise, record that this pack
947 * has windows in use.
948 */
949 if (w->inuse_cnt) {
950 if (*accept_windows_inuse)
951 has_windows_inuse = 1;
952 else
953 return;
954 }
955
956 if (w->last_used > this_mru_w->last_used)
957 this_mru_w = w;
958
959 /*
960 * Reject this pack if it has windows that have been
961 * used more recently than the previously selected pack.
962 * If the previously selected pack had windows inuse and
963 * we have not encountered a window in this pack that is
964 * inuse, skip this check since we prefer a pack with no
965 * inuse windows to one that has inuse windows.
966 */
967 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
968 this_mru_w->last_used > (*mru_w)->last_used)
969 return;
970 }
971
972 /*
973 * Select this pack.
974 */
975 *mru_w = this_mru_w;
976 *lru_p = p;
977 *accept_windows_inuse = has_windows_inuse;
978}
979
980static int close_one_pack(void)
981{
982 struct packed_git *p, *lru_p = NULL;
983 struct pack_window *mru_w = NULL;
984 int accept_windows_inuse = 1;
985
986 for (p = packed_git; p; p = p->next) {
987 if (p->pack_fd == -1)
988 continue;
989 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
990 }
991
71fe5d7f
JS
992 if (lru_p)
993 return close_pack_fd(lru_p);
88d0db55
BC
994
995 return 0;
996}
997
03e79c88 998void unuse_pack(struct pack_window **w_cursor)
f9253394 999{
03e79c88
SP
1000 struct pack_window *w = *w_cursor;
1001 if (w) {
1002 w->inuse_cnt--;
1003 *w_cursor = NULL;
1004 }
1f688557
JH
1005}
1006
fa5fc15d
SP
1007void close_pack_index(struct packed_git *p)
1008{
1009 if (p->index_data) {
1010 munmap((void *)p->index_data, p->index_size);
1011 p->index_data = NULL;
1012 }
1013}
1014
a0788266
JS
1015static unsigned int get_max_fd_limit(void)
1016{
1017#ifdef RLIMIT_NOFILE
491a8dec
JH
1018 {
1019 struct rlimit lim;
a0788266 1020
491a8dec
JH
1021 if (!getrlimit(RLIMIT_NOFILE, &lim))
1022 return lim.rlim_cur;
1023 }
1024#endif
1025
1026#ifdef _SC_OPEN_MAX
1027 {
1028 long open_max = sysconf(_SC_OPEN_MAX);
1029 if (0 < open_max)
1030 return open_max;
1031 /*
1032 * Otherwise, we got -1 for one of the two
1033 * reasons:
1034 *
1035 * (1) sysconf() did not understand _SC_OPEN_MAX
1036 * and signaled an error with -1; or
1037 * (2) sysconf() said there is no limit.
1038 *
1039 * We _could_ clear errno before calling sysconf() to
1040 * tell these two cases apart and return a huge number
1041 * in the latter case to let the caller cap it to a
1042 * value that is not so selfish, but letting the
1043 * fallback OPEN_MAX codepath take care of these cases
1044 * is a lot simpler.
1045 */
1046 }
1047#endif
a0788266 1048
491a8dec 1049#ifdef OPEN_MAX
a0788266
JS
1050 return OPEN_MAX;
1051#else
1052 return 1; /* see the caller ;-) */
1053#endif
1054}
1055
3cf8b462
SP
1056/*
1057 * Do not call this directly as this leaks p->pack_fd on error return;
1058 * call open_packed_git() instead.
1059 */
1060static int open_packed_git_1(struct packed_git *p)
1f688557 1061{
9bc879c1
SP
1062 struct stat st;
1063 struct pack_header hdr;
1064 unsigned char sha1[20];
1065 unsigned char *idx_sha1;
2c039da8 1066 long fd_flag;
9bc879c1 1067
d079837e
SP
1068 if (!p->index_data && open_pack_index(p))
1069 return error("packfile %s index unavailable", p->pack_name);
1070
c7934306 1071 if (!pack_max_fds) {
a0788266 1072 unsigned int max_fds = get_max_fd_limit();
c7934306
SP
1073
1074 /* Save 3 for stdin/stdout/stderr, 22 for work */
1075 if (25 < max_fds)
1076 pack_max_fds = max_fds - 25;
1077 else
1078 pack_max_fds = 1;
1079 }
1080
88d0db55 1081 while (pack_max_fds <= pack_open_fds && close_one_pack())
c7934306
SP
1082 ; /* nothing */
1083
a5436b57 1084 p->pack_fd = git_open(p->pack_name);
9bc879c1 1085 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 1086 return -1;
c7934306 1087 pack_open_fds++;
9bc879c1
SP
1088
1089 /* If we created the struct before we had the pack we lack size. */
bf592c50 1090 if (!p->pack_size) {
bf592c50 1091 if (!S_ISREG(st.st_mode))
072db278 1092 return error("packfile %s not a regular file", p->pack_name);
bf592c50 1093 p->pack_size = st.st_size;
9bc879c1 1094 } else if (p->pack_size != st.st_size)
072db278 1095 return error("packfile %s size changed", p->pack_name);
9bc879c1 1096
2c039da8
JH
1097 /* We leave these file descriptors open with sliding mmap;
1098 * there is no point keeping them open across exec(), though.
1099 */
1100 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
1101 if (fd_flag < 0)
072db278 1102 return error("cannot determine file descriptor flags");
2c039da8
JH
1103 fd_flag |= FD_CLOEXEC;
1104 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 1105 return error("cannot set FD_CLOEXEC");
2c039da8 1106
9bc879c1 1107 /* Verify we recognize this pack file format. */
e6e2bd62 1108 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 1109 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 1110 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 1111 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 1112 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
1113 return error("packfile %s is version %"PRIu32" and not"
1114 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
1115 p->pack_name, ntohl(hdr.hdr_version));
1116
1117 /* Verify the pack matches its index. */
57059091 1118 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
1119 return error("packfile %s claims to have %"PRIu32" objects"
1120 " while index indicates %"PRIu32" objects",
57059091
NP
1121 p->pack_name, ntohl(hdr.hdr_entries),
1122 p->num_objects);
9bc879c1 1123 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 1124 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 1125 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 1126 return error("packfile %s signature is unavailable", p->pack_name);
42873078 1127 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 1128 if (hashcmp(sha1, idx_sha1))
072db278
SP
1129 return error("packfile %s does not match index", p->pack_name);
1130 return 0;
9bc879c1
SP
1131}
1132
3cf8b462
SP
1133static int open_packed_git(struct packed_git *p)
1134{
1135 if (!open_packed_git_1(p))
1136 return 0;
71fe5d7f 1137 close_pack_fd(p);
3cf8b462
SP
1138 return -1;
1139}
1140
c4001d92 1141static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
1142{
1143 /* We must promise at least 20 bytes (one hash) after the
1144 * offset is available from this window, otherwise the offset
1145 * is not actually in this window and a different window (which
1146 * has that one hash excess) must be used. This is to support
1147 * the object header and delta base parsing routines below.
1148 */
1149 off_t win_off = win->offset;
1150 return win_off <= offset
1151 && (offset + 20) <= (win_off + win->len);
1152}
1153
4b25d091 1154unsigned char *use_pack(struct packed_git *p,
03e79c88 1155 struct pack_window **w_cursor,
c4001d92 1156 off_t offset,
ef49a7a0 1157 unsigned long *left)
9bc879c1 1158{
60bb8b14 1159 struct pack_window *win = *w_cursor;
03e79c88 1160
a9d98a14 1161 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
1162 * pointless to ask for an offset into the middle of that
1163 * hash, and the in_window function above wouldn't match
1164 * don't allow an offset too close to the end of the file.
1165 */
d131b7af
SP
1166 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1167 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
1168 if (offset > (p->pack_size - 20))
1169 die("offset beyond end of packfile (truncated pack?)");
13e0b0d3 1170 if (offset < 0)
7465feba 1171 die(_("offset before end of packfile (broken .idx?)"));
60bb8b14
SP
1172
1173 if (!win || !in_window(win, offset)) {
1174 if (win)
1175 win->inuse_cnt--;
1176 for (win = p->windows; win; win = win->next) {
1177 if (in_window(win, offset))
1178 break;
1179 }
1180 if (!win) {
78a28df9 1181 size_t window_align = packed_git_window_size / 2;
dc49cd76 1182 off_t len;
d131b7af
SP
1183
1184 if (p->pack_fd == -1 && open_packed_git(p))
1185 die("packfile %s cannot be accessed", p->pack_name);
1186
60bb8b14 1187 win = xcalloc(1, sizeof(*win));
78a28df9 1188 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
1189 len = p->pack_size - win->offset;
1190 if (len > packed_git_window_size)
1191 len = packed_git_window_size;
1192 win->len = (size_t)len;
60bb8b14 1193 pack_mapped += win->len;
11daf39b 1194 while (packed_git_limit < pack_mapped
7c3ecb32 1195 && unuse_one_window(p))
60bb8b14 1196 ; /* nothing */
c4712e45 1197 win->base = xmmap(NULL, win->len,
60bb8b14
SP
1198 PROT_READ, MAP_PRIVATE,
1199 p->pack_fd, win->offset);
1200 if (win->base == MAP_FAILED)
7616c6ca
NTND
1201 die_errno("packfile %s cannot be mapped",
1202 p->pack_name);
d131b7af 1203 if (!win->offset && win->len == p->pack_size
71fe5d7f
JS
1204 && !p->do_not_close)
1205 close_pack_fd(p);
a53128b6
SP
1206 pack_mmap_calls++;
1207 pack_open_windows++;
1208 if (pack_mapped > peak_pack_mapped)
1209 peak_pack_mapped = pack_mapped;
1210 if (pack_open_windows > peak_pack_open_windows)
1211 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
1212 win->next = p->windows;
1213 p->windows = win;
1214 }
1f688557 1215 }
03e79c88
SP
1216 if (win != *w_cursor) {
1217 win->last_used = pack_used_ctr++;
1218 win->inuse_cnt++;
1219 *w_cursor = win;
1220 }
60bb8b14 1221 offset -= win->offset;
03e79c88 1222 if (left)
dc49cd76 1223 *left = win->len - xsize_t(offset);
03e79c88 1224 return win->base + offset;
1f688557
JH
1225}
1226
27d69a46
NP
1227static struct packed_git *alloc_packed_git(int extra)
1228{
50a6c8ef 1229 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
27d69a46
NP
1230 memset(p, 0, sizeof(*p));
1231 p->pack_fd = -1;
1232 return p;
1233}
1234
e0500293
JN
1235static void try_to_free_pack_memory(size_t size)
1236{
7c3ecb32 1237 release_pack_memory(size);
e0500293
JN
1238}
1239
48bcc1c3 1240struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1f688557 1241{
e0500293 1242 static int have_set_try_to_free_routine;
1f688557 1243 struct stat st;
48bcc1c3
JK
1244 size_t alloc;
1245 struct packed_git *p;
1f688557 1246
e0500293
JN
1247 if (!have_set_try_to_free_routine) {
1248 have_set_try_to_free_routine = 1;
1249 set_try_to_free_routine(try_to_free_pack_memory);
1250 }
1251
42873078
NP
1252 /*
1253 * Make sure a corresponding .pack file exists and that
1254 * the index looks sane.
1255 */
48bcc1c3 1256 if (!strip_suffix_mem(path, &path_len, ".idx"))
1f688557 1257 return NULL;
48bcc1c3
JK
1258
1259 /*
1260 * ".pack" is long enough to hold any suffix we're adding (and
1261 * the use xsnprintf double-checks that)
1262 */
50a6c8ef 1263 alloc = st_add3(path_len, strlen(".pack"), 1);
48bcc1c3 1264 p = alloc_packed_git(alloc);
42873078 1265 memcpy(p->pack_name, path, path_len);
8d25931d 1266
48bcc1c3 1267 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
8d25931d
BC
1268 if (!access(p->pack_name, F_OK))
1269 p->pack_keep = 1;
1270
48bcc1c3 1271 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
d079837e 1272 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 1273 free(p);
1f688557
JH
1274 return NULL;
1275 }
42873078 1276
1f688557
JH
1277 /* ok, it looks sane as far as we can check without
1278 * actually mapping the pack file.
1279 */
1f688557 1280 p->pack_size = st.st_size;
9d835df2 1281 p->pack_local = local;
b867092f 1282 p->mtime = st.st_mtime;
42873078
NP
1283 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1284 hashclr(p->sha1);
1f688557
JH
1285 return p;
1286}
1287
7b64469a 1288struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 1289{
42873078 1290 const char *path = sha1_pack_name(sha1);
50a6c8ef 1291 size_t alloc = st_add(strlen(path), 1);
c7ab0ba3 1292 struct packed_git *p = alloc_packed_git(alloc);
bf592c50 1293
c7ab0ba3 1294 memcpy(p->pack_name, path, alloc); /* includes NUL */
27d69a46 1295 hashcpy(p->sha1, sha1);
42873078
NP
1296 if (check_packed_git_idx(idx_path, p)) {
1297 free(p);
bf592c50 1298 return NULL;
42873078 1299 }
bf592c50 1300
bf592c50
DB
1301 return p;
1302}
1303
1304void install_packed_git(struct packed_git *pack)
1305{
c7934306
SP
1306 if (pack->pack_fd != -1)
1307 pack_open_fds++;
1308
bf592c50
DB
1309 pack->next = packed_git;
1310 packed_git = pack;
1311}
1312
0a489b06 1313void (*report_garbage)(unsigned seen_bits, const char *path);
543c5caa
NTND
1314
1315static void report_helper(const struct string_list *list,
1316 int seen_bits, int first, int last)
1317{
0a489b06 1318 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
543c5caa 1319 return;
0a489b06 1320
543c5caa 1321 for (; first < last; first++)
0a489b06 1322 report_garbage(seen_bits, list->items[first].string);
543c5caa
NTND
1323}
1324
1325static void report_pack_garbage(struct string_list *list)
1326{
1327 int i, baselen = -1, first = 0, seen_bits = 0;
1328
1329 if (!report_garbage)
1330 return;
1331
3383e199 1332 string_list_sort(list);
543c5caa
NTND
1333
1334 for (i = 0; i < list->nr; i++) {
1335 const char *path = list->items[i].string;
1336 if (baselen != -1 &&
1337 strncmp(path, list->items[first].string, baselen)) {
1338 report_helper(list, seen_bits, first, i);
1339 baselen = -1;
1340 seen_bits = 0;
1341 }
1342 if (baselen == -1) {
1343 const char *dot = strrchr(path, '.');
1344 if (!dot) {
0a489b06 1345 report_garbage(PACKDIR_FILE_GARBAGE, path);
543c5caa
NTND
1346 continue;
1347 }
1348 baselen = dot - path + 1;
1349 first = i;
1350 }
1351 if (!strcmp(path + baselen, "pack"))
1352 seen_bits |= 1;
1353 else if (!strcmp(path + baselen, "idx"))
1354 seen_bits |= 2;
1355 }
1356 report_helper(list, seen_bits, first, list->nr);
1357}
1358
9d835df2 1359static void prepare_packed_git_one(char *objdir, int local)
1f688557 1360{
880fb8de
RS
1361 struct strbuf path = STRBUF_INIT;
1362 size_t dirnamelen;
1f688557
JH
1363 DIR *dir;
1364 struct dirent *de;
543c5caa 1365 struct string_list garbage = STRING_LIST_INIT_DUP;
1f688557 1366
880fb8de
RS
1367 strbuf_addstr(&path, objdir);
1368 strbuf_addstr(&path, "/pack");
1369 dir = opendir(path.buf);
b5b16990 1370 if (!dir) {
26125f6b 1371 if (errno != ENOENT)
7616c6ca
NTND
1372 error_errno("unable to open object pack directory: %s",
1373 path.buf);
880fb8de 1374 strbuf_release(&path);
1f688557 1375 return;
b5b16990 1376 }
880fb8de
RS
1377 strbuf_addch(&path, '/');
1378 dirnamelen = path.len;
1f688557 1379 while ((de = readdir(dir)) != NULL) {
1f688557 1380 struct packed_git *p;
47bf4b0f 1381 size_t base_len;
543c5caa
NTND
1382
1383 if (is_dot_or_dotdot(de->d_name))
9cb18f56
JM
1384 continue;
1385
880fb8de
RS
1386 strbuf_setlen(&path, dirnamelen);
1387 strbuf_addstr(&path, de->d_name);
d90906a9 1388
47bf4b0f
JK
1389 base_len = path.len;
1390 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
d90906a9
NTND
1391 /* Don't reopen a pack we already have. */
1392 for (p = packed_git; p; p = p->next) {
47bf4b0f
JK
1393 size_t len;
1394 if (strip_suffix(p->pack_name, ".pack", &len) &&
1395 len == base_len &&
1396 !memcmp(p->pack_name, path.buf, len))
d90906a9
NTND
1397 break;
1398 }
1399 if (p == NULL &&
1400 /*
1401 * See if it really is a valid .idx file with
1402 * corresponding .pack file that we can map.
1403 */
880fb8de 1404 (p = add_packed_git(path.buf, path.len, local)) != NULL)
d90906a9 1405 install_packed_git(p);
86f7780c 1406 }
543c5caa
NTND
1407
1408 if (!report_garbage)
1409 continue;
1410
2975c770
JK
1411 if (ends_with(de->d_name, ".idx") ||
1412 ends_with(de->d_name, ".pack") ||
1413 ends_with(de->d_name, ".bitmap") ||
1414 ends_with(de->d_name, ".keep"))
880fb8de 1415 string_list_append(&garbage, path.buf);
543c5caa 1416 else
0a489b06 1417 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1f688557 1418 }
5b35bcd5 1419 closedir(dir);
543c5caa
NTND
1420 report_pack_garbage(&garbage);
1421 string_list_clear(&garbage, 0);
880fb8de 1422 strbuf_release(&path);
1f688557
JH
1423}
1424
8e3f52d7
JK
1425static int approximate_object_count_valid;
1426
1427/*
1428 * Give a fast, rough count of the number of objects in the repository. This
1429 * ignores loose objects completely. If you have a lot of them, then either
1430 * you should repack because your performance will be awful, or they are
1431 * all unreachable objects about to be pruned, in which case they're not really
1432 * interesting as a measure of repo size in the first place.
1433 */
1434unsigned long approximate_object_count(void)
1435{
1436 static unsigned long count;
1437 if (!approximate_object_count_valid) {
1438 struct packed_git *p;
1439
1440 prepare_packed_git();
1441 count = 0;
1442 for (p = packed_git; p; p = p->next) {
1443 if (open_pack_index(p))
1444 continue;
1445 count += p->num_objects;
1446 }
1447 }
1448 return count;
1449}
1450
c4c6effa
RS
1451static void *get_next_packed_git(const void *p)
1452{
1453 return ((const struct packed_git *)p)->next;
1454}
1455
1456static void set_next_packed_git(void *p, void *next)
1457{
1458 ((struct packed_git *)p)->next = next;
1459}
1460
b867092f
JH
1461static int sort_pack(const void *a_, const void *b_)
1462{
c4c6effa
RS
1463 const struct packed_git *a = a_;
1464 const struct packed_git *b = b_;
b867092f
JH
1465 int st;
1466
1467 /*
1468 * Local packs tend to contain objects specific to our
1469 * variant of the project than remote ones. In addition,
1470 * remote ones could be on a network mounted filesystem.
1471 * Favor local ones for these reasons.
1472 */
1473 st = a->pack_local - b->pack_local;
1474 if (st)
1475 return -st;
1476
1477 /*
1478 * Younger packs tend to contain more recent objects,
1479 * and more recent objects tend to get accessed more
1480 * often.
1481 */
1482 if (a->mtime < b->mtime)
1483 return 1;
1484 else if (a->mtime == b->mtime)
1485 return 0;
1486 return -1;
1487}
1488
1489static void rearrange_packed_git(void)
1490{
c4c6effa
RS
1491 packed_git = llist_mergesort(packed_git, get_next_packed_git,
1492 set_next_packed_git, sort_pack);
b867092f
JH
1493}
1494
a73cdd21
JK
1495static void prepare_packed_git_mru(void)
1496{
1497 struct packed_git *p;
1498
1499 mru_clear(packed_git_mru);
1500 for (p = packed_git; p; p = p->next)
1501 mru_append(packed_git_mru, p);
1502}
1503
637cdd9d 1504static int prepare_packed_git_run_once = 0;
9a217f2a 1505void prepare_packed_git(void)
1f688557 1506{
d5a63b99 1507 struct alternate_object_database *alt;
1f688557 1508
637cdd9d 1509 if (prepare_packed_git_run_once)
1f688557 1510 return;
9d835df2 1511 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1512 prepare_alt_odb();
597f9134
JK
1513 for (alt = alt_odb_list; alt; alt = alt->next)
1514 prepare_packed_git_one(alt->path, 0);
b867092f 1515 rearrange_packed_git();
a73cdd21 1516 prepare_packed_git_mru();
637cdd9d
JK
1517 prepare_packed_git_run_once = 1;
1518}
1519
fc04c412 1520void reprepare_packed_git(void)
637cdd9d 1521{
8e3f52d7 1522 approximate_object_count_valid = 0;
637cdd9d
JK
1523 prepare_packed_git_run_once = 0;
1524 prepare_packed_git();
1f688557
JH
1525}
1526
8eca0b47
NP
1527static void mark_bad_packed_object(struct packed_git *p,
1528 const unsigned char *sha1)
1529{
1530 unsigned i;
1531 for (i = 0; i < p->num_bad_objects; i++)
50a6c8ef 1532 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
8eca0b47 1533 return;
50a6c8ef
JK
1534 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1535 st_mult(GIT_SHA1_RAWSZ,
1536 st_add(p->num_bad_objects, 1)));
1537 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
8eca0b47
NP
1538 p->num_bad_objects++;
1539}
1540
b6c4cecc 1541static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1542{
1543 struct packed_git *p;
1544 unsigned i;
1545
1546 for (p = packed_git; p; p = p->next)
1547 for (i = 0; i < p->num_bad_objects; i++)
1548 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1549 return p;
1550 return NULL;
ac939109
NP
1551}
1552
090ea126
NTND
1553/*
1554 * With an in-core object data in "map", rehash it to make sure the
1555 * object name actually matches "sha1" to detect object corruption.
1556 * With "map" == NULL, try reading the object named with "sha1" using
1557 * the streaming interface and rehash it to do the same.
1558 */
1559int check_sha1_signature(const unsigned char *sha1, void *map,
1560 unsigned long size, const char *type)
0fcfd160
LT
1561{
1562 unsigned char real_sha1[20];
090ea126
NTND
1563 enum object_type obj_type;
1564 struct git_istream *st;
1565 git_SHA_CTX c;
1566 char hdr[32];
1567 int hdrlen;
1568
1569 if (map) {
1570 hash_sha1_file(map, size, type, real_sha1);
1571 return hashcmp(sha1, real_sha1) ? -1 : 0;
1572 }
1573
1574 st = open_istream(sha1, &obj_type, &size, NULL);
1575 if (!st)
1576 return -1;
1577
1578 /* Generate the header */
ef1286d3 1579 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
090ea126
NTND
1580
1581 /* Sha1.. */
1582 git_SHA1_Init(&c);
1583 git_SHA1_Update(&c, hdr, hdrlen);
1584 for (;;) {
1585 char buf[1024 * 16];
1586 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1587
f54fac53
JK
1588 if (readlen < 0) {
1589 close_istream(st);
1590 return -1;
1591 }
090ea126
NTND
1592 if (!readlen)
1593 break;
1594 git_SHA1_Update(&c, buf, readlen);
1595 }
1596 git_SHA1_Final(real_sha1, &c);
1597 close_istream(st);
a89fccd2 1598 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1599}
1600
1b8ac5ea 1601int git_open_cloexec(const char *name, int flags)
44d1c19e 1602{
1e3001a8
JH
1603 int fd;
1604 static int o_cloexec = O_CLOEXEC;
f2e872aa 1605
1e3001a8
JH
1606 fd = open(name, flags | o_cloexec);
1607 if ((o_cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) {
cd66ada0 1608 /* Try again w/o O_CLOEXEC: the kernel might not support it */
1e3001a8
JH
1609 o_cloexec &= ~O_CLOEXEC;
1610 fd = open(name, flags | o_cloexec);
1b8ac5ea 1611 }
f2e872aa 1612
1e3001a8
JH
1613#if defined(F_GETFL) && defined(F_SETFL) && defined(FD_CLOEXEC)
1614 {
1615 static int fd_cloexec = FD_CLOEXEC;
1616
1617 if (!o_cloexec && 0 <= fd && fd_cloexec) {
1618 /* Opened w/o O_CLOEXEC? try with fcntl(2) to add it */
1619 int flags = fcntl(fd, F_GETFL);
1620 if (fcntl(fd, F_SETFL, flags | fd_cloexec))
1621 fd_cloexec = 0;
cd66ada0 1622 }
44d1c19e 1623 }
1e3001a8 1624#endif
1b8ac5ea 1625 return fd;
44d1c19e
LT
1626}
1627
771e7d57
JK
1628/*
1629 * Find "sha1" as a loose object in the local repository or in an alternate.
1630 * Returns 0 on success, negative on failure.
1631 *
1632 * The "path" out-parameter will give the path of the object we found (if any).
1633 * Note that it may point to static storage and is only valid until another
1634 * call to sha1_file_name(), etc.
1635 */
1636static int stat_sha1_file(const unsigned char *sha1, struct stat *st,
1637 const char **path)
052fe5ea 1638{
052fe5ea
JK
1639 struct alternate_object_database *alt;
1640
771e7d57
JK
1641 *path = sha1_file_name(sha1);
1642 if (!lstat(*path, st))
052fe5ea
JK
1643 return 0;
1644
1645 prepare_alt_odb();
1646 errno = ENOENT;
1647 for (alt = alt_odb_list; alt; alt = alt->next) {
771e7d57
JK
1648 *path = alt_sha1_path(alt, sha1);
1649 if (!lstat(*path, st))
052fe5ea
JK
1650 return 0;
1651 }
1652
1653 return -1;
1654}
1655
771e7d57
JK
1656/*
1657 * Like stat_sha1_file(), but actually open the object and return the
1658 * descriptor. See the caveats on the "path" parameter above.
1659 */
1660static int open_sha1_file(const unsigned char *sha1, const char **path)
44d1c19e
LT
1661{
1662 int fd;
44d1c19e 1663 struct alternate_object_database *alt;
d6c8a05b 1664 int most_interesting_errno;
44d1c19e 1665
771e7d57
JK
1666 *path = sha1_file_name(sha1);
1667 fd = git_open(*path);
44d1c19e
LT
1668 if (fd >= 0)
1669 return fd;
d6c8a05b 1670 most_interesting_errno = errno;
44d1c19e
LT
1671
1672 prepare_alt_odb();
44d1c19e 1673 for (alt = alt_odb_list; alt; alt = alt->next) {
771e7d57
JK
1674 *path = alt_sha1_path(alt, sha1);
1675 fd = git_open(*path);
44d1c19e
LT
1676 if (fd >= 0)
1677 return fd;
d6c8a05b
JK
1678 if (most_interesting_errno == ENOENT)
1679 most_interesting_errno = errno;
44d1c19e 1680 }
d6c8a05b 1681 errno = most_interesting_errno;
44d1c19e
LT
1682 return -1;
1683}
1684
f6371f92
JK
1685/*
1686 * Map the loose object at "path" if it is not NULL, or the path found by
1687 * searching for a loose object named "sha1".
1688 */
1689static void *map_sha1_file_1(const char *path,
1690 const unsigned char *sha1,
1691 unsigned long *size)
0fcfd160 1692{
0fcfd160 1693 void *map;
144bde78 1694 int fd;
ace1534d 1695
f6371f92
JK
1696 if (path)
1697 fd = git_open(path);
1698 else
1699 fd = open_sha1_file(sha1, &path);
44d1c19e
LT
1700 map = NULL;
1701 if (fd >= 0) {
1702 struct stat st;
0fcfd160 1703
44d1c19e
LT
1704 if (!fstat(fd, &st)) {
1705 *size = xsize_t(st.st_size);
33e42de0
MM
1706 if (!*size) {
1707 /* mmap() is forbidden on empty files */
771e7d57 1708 error("object file %s is empty", path);
33e42de0
MM
1709 return NULL;
1710 }
44d1c19e 1711 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1712 }
44d1c19e 1713 close(fd);
0fcfd160 1714 }
0fcfd160
LT
1715 return map;
1716}
1717
f6371f92
JK
1718void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1719{
1720 return map_sha1_file_1(NULL, sha1, size);
1721}
1722
09ded04b
NP
1723unsigned long unpack_object_header_buffer(const unsigned char *buf,
1724 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1725{
ad1ed5ee 1726 unsigned shift;
48fb7deb 1727 unsigned long size, c;
ad1ed5ee
JH
1728 unsigned long used = 0;
1729
1730 c = buf[used++];
1731 *type = (c >> 4) & 7;
1732 size = c & 15;
1733 shift = 4;
1734 while (c & 0x80) {
f630cfda 1735 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1736 error("bad object header");
ea4f9685
JH
1737 size = used = 0;
1738 break;
09ded04b 1739 }
ad1ed5ee
JH
1740 c = buf[used++];
1741 size += (c & 0x7f) << shift;
1742 shift += 7;
1743 }
1744 *sizep = size;
1745 return used;
1746}
1747
d21f8426
JH
1748static int unpack_sha1_short_header(git_zstream *stream,
1749 unsigned char *map, unsigned long mapsize,
1750 void *buffer, unsigned long bufsiz)
ad1ed5ee 1751{
c4483576
LT
1752 /* Get the data stream */
1753 memset(stream, 0, sizeof(*stream));
1754 stream->next_in = map;
1755 stream->avail_in = mapsize;
1756 stream->next_out = buffer;
93821bd9
LT
1757 stream->avail_out = bufsiz;
1758
39c68542 1759 git_inflate_init(stream);
cc5c54e7 1760 return git_inflate(stream, 0);
c4483576
LT
1761}
1762
d21f8426
JH
1763int unpack_sha1_header(git_zstream *stream,
1764 unsigned char *map, unsigned long mapsize,
1765 void *buffer, unsigned long bufsiz)
1766{
1767 int status = unpack_sha1_short_header(stream, map, mapsize,
1768 buffer, bufsiz);
1769
1770 if (status < Z_OK)
1771 return status;
1772
1773 /* Make sure we have the terminating NUL */
1774 if (!memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1775 return -1;
1776 return 0;
1777}
1778
46f03448
KN
1779static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1780 unsigned long mapsize, void *buffer,
1781 unsigned long bufsiz, struct strbuf *header)
1782{
1783 int status;
1784
d21f8426
JH
1785 status = unpack_sha1_short_header(stream, map, mapsize, buffer, bufsiz);
1786 if (status < Z_OK)
1787 return -1;
46f03448
KN
1788
1789 /*
1790 * Check if entire header is unpacked in the first iteration.
1791 */
1792 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1793 return 0;
1794
1795 /*
1796 * buffer[0..bufsiz] was not large enough. Copy the partial
1797 * result out to header, and then append the result of further
1798 * reading the stream.
1799 */
1800 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1801 stream->next_out = buffer;
1802 stream->avail_out = bufsiz;
1803
1804 do {
1805 status = git_inflate(stream, 0);
1806 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1807 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1808 return 0;
1809 stream->next_out = buffer;
1810 stream->avail_out = bufsiz;
1811 } while (status != Z_STREAM_END);
1812 return -1;
1813}
1814
ef49a7a0 1815static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1816{
1817 int bytes = strlen(buffer) + 1;
3aee68aa 1818 unsigned char *buf = xmallocz(size);
93821bd9 1819 unsigned long n;
7efbff75 1820 int status = Z_OK;
5180cacc 1821
93821bd9
LT
1822 n = stream->total_out - bytes;
1823 if (n > size)
1824 n = size;
1825 memcpy(buf, (char *) buffer + bytes, n);
1826 bytes = n;
456cdf6e
LT
1827 if (bytes <= size) {
1828 /*
1829 * The above condition must be (bytes <= size), not
1830 * (bytes < size). In other words, even though we
ccf5ace0 1831 * expect no more output and set avail_out to zero,
456cdf6e
LT
1832 * the input zlib stream may have bytes that express
1833 * "this concludes the stream", and we *do* want to
1834 * eat that input.
1835 *
1836 * Otherwise we would not be able to test that we
1837 * consumed all the input to reach the expected size;
1838 * we also want to check that zlib tells us that all
1839 * went well with status == Z_STREAM_END at the end.
1840 */
5180cacc
LT
1841 stream->next_out = buf + bytes;
1842 stream->avail_out = size - bytes;
7efbff75 1843 while (status == Z_OK)
39c68542 1844 status = git_inflate(stream, Z_FINISH);
5180cacc 1845 }
456cdf6e 1846 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1847 git_inflate_end(stream);
7efbff75
JH
1848 return buf;
1849 }
1850
1851 if (status < 0)
1852 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1853 else if (stream->avail_in)
1854 error("garbage at end of loose object '%s'",
1855 sha1_to_hex(sha1));
1856 free(buf);
1857 return NULL;
5180cacc
LT
1858}
1859
1860/*
1861 * We used to just use "sscanf()", but that's actually way
1862 * too permissive for what we want to check. So do an anal
1863 * object header parse by hand.
1864 */
46f03448
KN
1865static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1866 unsigned int flags)
5180cacc 1867{
46f03448 1868 const char *type_buf = hdr;
5180cacc 1869 unsigned long size;
46f03448 1870 int type, type_len = 0;
5180cacc
LT
1871
1872 /*
46f03448 1873 * The type can be of any size but is followed by
21666f1a 1874 * a space.
5180cacc 1875 */
5180cacc
LT
1876 for (;;) {
1877 char c = *hdr++;
d21f8426
JH
1878 if (!c)
1879 return -1;
5180cacc
LT
1880 if (c == ' ')
1881 break;
46f03448 1882 type_len++;
5180cacc 1883 }
46f03448
KN
1884
1885 type = type_from_string_gently(type_buf, type_len, 1);
1886 if (oi->typename)
1887 strbuf_add(oi->typename, type_buf, type_len);
1888 /*
1889 * Set type to 0 if its an unknown object and
2e3a16b2 1890 * we're obtaining the type using '--allow-unknown-type'
46f03448
KN
1891 * option.
1892 */
1893 if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
1894 type = 0;
1895 else if (type < 0)
1896 die("invalid object type");
1897 if (oi->typep)
1898 *oi->typep = type;
5180cacc
LT
1899
1900 /*
1901 * The length must follow immediately, and be in canonical
1902 * decimal format (ie "010" is not valid).
1903 */
1904 size = *hdr++ - '0';
1905 if (size > 9)
1906 return -1;
1907 if (size) {
1908 for (;;) {
1909 unsigned long c = *hdr - '0';
1910 if (c > 9)
1911 break;
1912 hdr++;
1913 size = size * 10 + c;
1914 }
1915 }
46f03448
KN
1916
1917 if (oi->sizep)
1918 *oi->sizep = size;
5180cacc
LT
1919
1920 /*
1921 * The length must be followed by a zero byte
1922 */
46f03448
KN
1923 return *hdr ? -1 : type;
1924}
1925
1926int parse_sha1_header(const char *hdr, unsigned long *sizep)
1927{
27b5c1a0 1928 struct object_info oi = OBJECT_INFO_INIT;
46f03448
KN
1929
1930 oi.sizep = sizep;
46f03448 1931 return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
5180cacc
LT
1932}
1933
7efbff75 1934static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1935{
5180cacc 1936 int ret;
ef49a7a0 1937 git_zstream stream;
5180cacc 1938 char hdr[8192];
0fcfd160 1939
5180cacc 1940 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1941 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1942 return NULL;
1943
7efbff75 1944 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1945}
1946
54dab52a
NP
1947unsigned long get_size_from_delta(struct packed_git *p,
1948 struct pack_window **w_curs,
1949 off_t curpos)
1950{
1951 const unsigned char *data;
1952 unsigned char delta_head[20], *in;
ef49a7a0 1953 git_zstream stream;
54dab52a
NP
1954 int st;
1955
1956 memset(&stream, 0, sizeof(stream));
1957 stream.next_out = delta_head;
1958 stream.avail_out = sizeof(delta_head);
1959
39c68542 1960 git_inflate_init(&stream);
54dab52a
NP
1961 do {
1962 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1963 stream.next_in = in;
39c68542 1964 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1965 curpos += stream.next_in - in;
1966 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1967 stream.total_out < sizeof(delta_head));
39c68542 1968 git_inflate_end(&stream);
3d77d877
NP
1969 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1970 error("delta data unpack-initial failed");
1971 return 0;
1972 }
54dab52a
NP
1973
1974 /* Examine the initial part of the delta to figure out
1975 * the result size.
1976 */
1977 data = delta_head;
1978
1979 /* ignore base size */
1980 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1981
1982 /* Read the result size */
1983 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1984}
1985
c4001d92 1986static off_t get_delta_base(struct packed_git *p,
03e79c88 1987 struct pack_window **w_curs,
c4001d92 1988 off_t *curpos,
21666f1a 1989 enum object_type type,
c4001d92 1990 off_t delta_obj_offset)
eb32d236 1991{
2b87c45b 1992 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1993 off_t base_offset;
eb32d236 1994
8d8a4ea5
SP
1995 /* use_pack() assured us we have [base_info, base_info + 20)
1996 * as a range that we can look at without walking off the
1997 * end of the mapped window. Its actually the hash size
1998 * that is assured. An OFS_DELTA longer than the hash size
1999 * is stupid, as then a REF_DELTA would be smaller to store.
2000 */
21666f1a 2001 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
2002 unsigned used = 0;
2003 unsigned char c = base_info[used++];
2004 base_offset = c & 127;
2005 while (c & 128) {
2006 base_offset += 1;
8723f216 2007 if (!base_offset || MSB(base_offset, 7))
8eca0b47 2008 return 0; /* overflow */
eb32d236
NP
2009 c = base_info[used++];
2010 base_offset = (base_offset << 7) + (c & 127);
2011 }
2012 base_offset = delta_obj_offset - base_offset;
d8f32556 2013 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 2014 return 0; /* out of bound */
2b87c45b 2015 *curpos += used;
21666f1a 2016 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
2017 /* The base entry _must_ be in the same pack */
2018 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 2019 *curpos += 20;
eb32d236
NP
2020 } else
2021 die("I am totally screwed");
2b87c45b 2022 return base_offset;
eb32d236
NP
2023}
2024
5d642e75
JK
2025/*
2026 * Like get_delta_base above, but we return the sha1 instead of the pack
2027 * offset. This means it is cheaper for REF deltas (we do not have to do
2028 * the final object lookup), but more expensive for OFS deltas (we
2029 * have to load the revidx to convert the offset back into a sha1).
2030 */
2031static const unsigned char *get_delta_base_sha1(struct packed_git *p,
2032 struct pack_window **w_curs,
2033 off_t curpos,
2034 enum object_type type,
2035 off_t delta_obj_offset)
2036{
2037 if (type == OBJ_REF_DELTA) {
2038 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
2039 return base;
2040 } else if (type == OBJ_OFS_DELTA) {
2041 struct revindex_entry *revidx;
2042 off_t base_offset = get_delta_base(p, w_curs, &curpos,
2043 type, delta_obj_offset);
2044
2045 if (!base_offset)
2046 return NULL;
2047
2048 revidx = find_pack_revindex(p, base_offset);
2049 if (!revidx)
2050 return NULL;
2051
2052 return nth_packed_object_sha1(p, revidx->nr);
2053 } else
2054 return NULL;
2055}
2056
f8c8abc5
JH
2057int unpack_object_header(struct packed_git *p,
2058 struct pack_window **w_curs,
2059 off_t *curpos,
2060 unsigned long *sizep)
a733cb60 2061{
03e79c88 2062 unsigned char *base;
ef49a7a0 2063 unsigned long left;
ad1ed5ee 2064 unsigned long used;
2b87c45b 2065 enum object_type type;
a733cb60 2066
8d8a4ea5 2067 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 2068 * as a range that we can look at. (Its actually the hash
3dff5379 2069 * size that is assured.) With our object header encoding
8d8a4ea5
SP
2070 * the maximum deflated object size is 2^137, which is just
2071 * insane, so we know won't exceed what we have been given.
2072 */
2b87c45b 2073 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
2074 used = unpack_object_header_buffer(base, left, &type, sizep);
2075 if (!used) {
2076 type = OBJ_BAD;
2077 } else
2078 *curpos += used;
ad1ed5ee 2079
2b87c45b 2080 return type;
a733cb60
LT
2081}
2082
790d96c0
TR
2083static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
2084{
2085 int type;
2086 struct revindex_entry *revidx;
2087 const unsigned char *sha1;
2088 revidx = find_pack_revindex(p, obj_offset);
2089 if (!revidx)
2090 return OBJ_BAD;
2091 sha1 = nth_packed_object_sha1(p, revidx->nr);
2092 mark_bad_packed_object(p, sha1);
2093 type = sha1_object_info(sha1, NULL);
2094 if (type <= OBJ_NONE)
2095 return OBJ_BAD;
2096 return type;
2097}
2098
790d96c0
TR
2099#define POI_STACK_PREALLOC 64
2100
90191d37
JK
2101static enum object_type packed_to_object_type(struct packed_git *p,
2102 off_t obj_offset,
2103 enum object_type type,
2104 struct pack_window **w_curs,
2105 off_t curpos)
1f688557 2106{
790d96c0
TR
2107 off_t small_poi_stack[POI_STACK_PREALLOC];
2108 off_t *poi_stack = small_poi_stack;
2109 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
5db47c2b 2110
790d96c0
TR
2111 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2112 off_t base_offset;
90191d37 2113 unsigned long size;
790d96c0
TR
2114 /* Push the object we're going to leave behind */
2115 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
2116 poi_stack_alloc = alloc_nr(poi_stack_nr);
b32fa95f 2117 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
790d96c0
TR
2118 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
2119 } else {
2120 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
2121 }
2122 poi_stack[poi_stack_nr++] = obj_offset;
2123 /* If parsing the base offset fails, just unwind */
90191d37 2124 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
790d96c0
TR
2125 if (!base_offset)
2126 goto unwind;
2127 curpos = obj_offset = base_offset;
90191d37 2128 type = unpack_object_header(p, w_curs, &curpos, &size);
790d96c0
TR
2129 if (type <= OBJ_NONE) {
2130 /* If getting the base itself fails, we first
2131 * retry the base, otherwise unwind */
2132 type = retry_bad_packed_offset(p, base_offset);
2133 if (type > OBJ_NONE)
2134 goto out;
2135 goto unwind;
2136 }
2137 }
2138
21666f1a 2139 switch (type) {
790d96c0 2140 case OBJ_BAD:
a733cb60 2141 case OBJ_COMMIT:
a733cb60 2142 case OBJ_TREE:
a733cb60 2143 case OBJ_BLOB:
a733cb60 2144 case OBJ_TAG:
a69d0943 2145 break;
1f688557 2146 default:
3d77d877
NP
2147 error("unknown object type %i at offset %"PRIuMAX" in %s",
2148 type, (uintmax_t)obj_offset, p->pack_name);
2149 type = OBJ_BAD;
1f688557 2150 }
790d96c0
TR
2151
2152out:
2153 if (poi_stack != small_poi_stack)
2154 free(poi_stack);
21666f1a 2155 return type;
790d96c0
TR
2156
2157unwind:
2158 while (poi_stack_nr) {
2159 obj_offset = poi_stack[--poi_stack_nr];
2160 type = retry_bad_packed_offset(p, obj_offset);
2161 if (type > OBJ_NONE)
2162 goto out;
2163 }
2164 type = OBJ_BAD;
2165 goto out;
1f688557
JH
2166}
2167
ca79c985
JK
2168int packed_object_info(struct packed_git *p, off_t obj_offset,
2169 struct object_info *oi)
90191d37
JK
2170{
2171 struct pack_window *w_curs = NULL;
2172 unsigned long size;
2173 off_t curpos = obj_offset;
2174 enum object_type type;
2175
412916ee
JK
2176 /*
2177 * We always get the representation type, but only convert it to
2178 * a "real" type later if the caller is interested.
2179 */
90191d37
JK
2180 type = unpack_object_header(p, &w_curs, &curpos, &size);
2181
23c339c0 2182 if (oi->sizep) {
90191d37
JK
2183 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2184 off_t tmp_pos = curpos;
2185 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2186 type, obj_offset);
2187 if (!base_offset) {
2188 type = OBJ_BAD;
2189 goto out;
2190 }
23c339c0
JK
2191 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2192 if (*oi->sizep == 0) {
90191d37
JK
2193 type = OBJ_BAD;
2194 goto out;
2195 }
2196 } else {
23c339c0 2197 *oi->sizep = size;
90191d37
JK
2198 }
2199 }
2200
23c339c0 2201 if (oi->disk_sizep) {
90191d37 2202 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
23c339c0 2203 *oi->disk_sizep = revidx[1].offset - obj_offset;
90191d37
JK
2204 }
2205
23c339c0
JK
2206 if (oi->typep) {
2207 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
2208 if (*oi->typep < 0) {
412916ee
JK
2209 type = OBJ_BAD;
2210 goto out;
2211 }
2212 }
90191d37 2213
5d642e75
JK
2214 if (oi->delta_base_sha1) {
2215 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2216 const unsigned char *base;
2217
2218 base = get_delta_base_sha1(p, &w_curs, curpos,
2219 type, obj_offset);
2220 if (!base) {
2221 type = OBJ_BAD;
2222 goto out;
2223 }
2224
2225 hashcpy(oi->delta_base_sha1, base);
2226 } else
2227 hashclr(oi->delta_base_sha1);
2228 }
2229
90191d37
JK
2230out:
2231 unuse_pack(&w_curs);
2232 return type;
2233}
2234
eb950c19 2235static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 2236 struct pack_window **w_curs,
c4001d92 2237 off_t curpos,
eb950c19 2238 unsigned long size)
de530aaa
SP
2239{
2240 int st;
ef49a7a0 2241 git_zstream stream;
079afb18 2242 unsigned char *buffer, *in;
de530aaa 2243
735efde8
NTND
2244 buffer = xmallocz_gently(size);
2245 if (!buffer)
2246 return NULL;
de530aaa 2247 memset(&stream, 0, sizeof(stream));
de530aaa 2248 stream.next_out = buffer;
39eea7bd 2249 stream.avail_out = size + 1;
de530aaa 2250
39c68542 2251 git_inflate_init(&stream);
079afb18 2252 do {
2b87c45b 2253 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 2254 stream.next_in = in;
39c68542 2255 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
2256 if (!stream.avail_out)
2257 break; /* the payload is larger than it should be */
2b87c45b 2258 curpos += stream.next_in - in;
079afb18 2259 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 2260 git_inflate_end(&stream);
de530aaa
SP
2261 if ((st != Z_STREAM_END) || stream.total_out != size) {
2262 free(buffer);
2263 return NULL;
2264 }
2265
2266 return buffer;
2267}
2268
8261e1f1 2269static struct hashmap delta_base_cache;
18bdec11 2270static size_t delta_base_cached;
5e08ecbf 2271
12d95ef6 2272static LIST_HEAD(delta_base_cache_lru);
5e08ecbf 2273
8261e1f1 2274struct delta_base_cache_key {
e5e01619
LT
2275 struct packed_git *p;
2276 off_t base_offset;
8261e1f1
JK
2277};
2278
2279struct delta_base_cache_entry {
2280 struct hashmap hash;
2281 struct delta_base_cache_key key;
2282 struct list_head lru;
2283 void *data;
e5e01619 2284 unsigned long size;
e5e01619 2285 enum object_type type;
8261e1f1 2286};
e5e01619 2287
8261e1f1 2288static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
e5e01619 2289{
8261e1f1 2290 unsigned int hash;
e5e01619 2291
8261e1f1 2292 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
e5e01619 2293 hash += (hash >> 8) + (hash >> 16);
8261e1f1 2294 return hash;
e5e01619
LT
2295}
2296
84dd81c1
TR
2297static struct delta_base_cache_entry *
2298get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
5266d369 2299{
8261e1f1
JK
2300 struct hashmap_entry entry;
2301 struct delta_base_cache_key key;
2302
2303 if (!delta_base_cache.cmpfn)
2304 return NULL;
2305
2306 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
2307 key.p = p;
2308 key.base_offset = base_offset;
2309 return hashmap_get(&delta_base_cache, &entry, &key);
2310}
2311
2312static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
2313 const struct delta_base_cache_key *b)
2314{
2315 return a->p == b->p && a->base_offset == b->base_offset;
84dd81c1
TR
2316}
2317
8261e1f1
JK
2318static int delta_base_cache_hash_cmp(const void *va, const void *vb,
2319 const void *vkey)
84dd81c1 2320{
8261e1f1
JK
2321 const struct delta_base_cache_entry *a = va, *b = vb;
2322 const struct delta_base_cache_key *key = vkey;
2323 if (key)
2324 return !delta_base_cache_key_eq(&a->key, key);
2325 else
2326 return !delta_base_cache_key_eq(&a->key, &b->key);
5266d369
JH
2327}
2328
84dd81c1
TR
2329static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2330{
8261e1f1 2331 return !!get_delta_base_cache_entry(p, base_offset);
84dd81c1
TR
2332}
2333
4a5397ca
JK
2334/*
2335 * Remove the entry from the cache, but do _not_ free the associated
2336 * entry data. The caller takes ownership of the "data" buffer, and
2337 * should copy out any fields it wants before detaching.
2338 */
2339static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
84dd81c1 2340{
8261e1f1 2341 hashmap_remove(&delta_base_cache, ent, &ent->key);
12d95ef6 2342 list_del(&ent->lru);
84dd81c1 2343 delta_base_cached -= ent->size;
8261e1f1 2344 free(ent);
84dd81c1
TR
2345}
2346
62f255ad 2347static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
85fe35ab 2348 unsigned long *base_size, enum object_type *type)
62f255ad 2349{
84dd81c1 2350 struct delta_base_cache_entry *ent;
e5e01619 2351
84dd81c1 2352 ent = get_delta_base_cache_entry(p, base_offset);
8261e1f1 2353 if (!ent)
749bc58c 2354 return unpack_entry(p, base_offset, type, base_size);
e5e01619 2355
e5e01619
LT
2356 *type = ent->type;
2357 *base_size = ent->size;
85fe35ab 2358 return xmemdupz(ent->data, ent->size);
62f255ad
LT
2359}
2360
18bdec11
SP
2361static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2362{
8261e1f1
JK
2363 free(ent->data);
2364 detach_delta_base_cache_entry(ent);
18bdec11
SP
2365}
2366
3d20c636
SP
2367void clear_delta_base_cache(void)
2368{
abd5a002
JK
2369 struct list_head *lru, *tmp;
2370 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
2371 struct delta_base_cache_entry *entry =
2372 list_entry(lru, struct delta_base_cache_entry, lru);
8261e1f1
JK
2373 release_delta_base_cache(entry);
2374 }
3d20c636
SP
2375}
2376
62f255ad
LT
2377static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2378 void *base, unsigned long base_size, enum object_type type)
2379{
8261e1f1 2380 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
4b92bae7 2381 struct list_head *lru, *tmp;
e5e01619 2382
18bdec11 2383 delta_base_cached += base_size;
5e08ecbf 2384
4b92bae7 2385 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
12d95ef6
JK
2386 struct delta_base_cache_entry *f =
2387 list_entry(lru, struct delta_base_cache_entry, lru);
2388 if (delta_base_cached <= delta_base_cache_limit)
2389 break;
5e08ecbf
NP
2390 release_delta_base_cache(f);
2391 }
18bdec11 2392
8261e1f1
JK
2393 ent->key.p = p;
2394 ent->key.base_offset = base_offset;
e5e01619
LT
2395 ent->type = type;
2396 ent->data = base;
2397 ent->size = base_size;
12d95ef6 2398 list_add_tail(&ent->lru, &delta_base_cache_lru);
8261e1f1
JK
2399
2400 if (!delta_base_cache.cmpfn)
2401 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, 0);
2402 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
2403 hashmap_add(&delta_base_cache, ent);
62f255ad
LT
2404}
2405
c2c5b270
CC
2406static void *read_object(const unsigned char *sha1, enum object_type *type,
2407 unsigned long *size);
2408
5f44324d
JH
2409static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2410{
67dc598e
KB
2411 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2412 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2413 p->pack_name, (uintmax_t)obj_offset);
5f44324d
JH
2414}
2415
0e8189e2
NP
2416int do_check_packed_object_crc;
2417
abe601bb
TR
2418#define UNPACK_ENTRY_STACK_PREALLOC 64
2419struct unpack_entry_stack_ent {
2420 off_t obj_offset;
2421 off_t curpos;
2422 unsigned long size;
2423};
2424
c4001d92 2425void *unpack_entry(struct packed_git *p, off_t obj_offset,
abe601bb 2426 enum object_type *final_type, unsigned long *final_size)
1f688557 2427{
03e79c88 2428 struct pack_window *w_curs = NULL;
c4001d92 2429 off_t curpos = obj_offset;
abe601bb
TR
2430 void *data = NULL;
2431 unsigned long size;
2432 enum object_type type;
2433 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2434 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2435 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2436 int base_from_cache = 0;
1f688557 2437
67dc598e 2438 write_pack_access_log(p, obj_offset);
5f44324d 2439
abe601bb
TR
2440 /* PHASE 1: drill down to the innermost base object */
2441 for (;;) {
2442 off_t base_offset;
2443 int i;
2444 struct delta_base_cache_entry *ent;
2445
77965f8b 2446 ent = get_delta_base_cache_entry(p, curpos);
8261e1f1 2447 if (ent) {
77965f8b
NTND
2448 type = ent->type;
2449 data = ent->data;
2450 size = ent->size;
4a5397ca 2451 detach_delta_base_cache_entry(ent);
77965f8b
NTND
2452 base_from_cache = 1;
2453 break;
2454 }
2455
abe601bb
TR
2456 if (do_check_packed_object_crc && p->index_version > 1) {
2457 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
211c61c6 2458 off_t len = revidx[1].offset - obj_offset;
abe601bb
TR
2459 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2460 const unsigned char *sha1 =
2461 nth_packed_object_sha1(p, revidx->nr);
2462 error("bad packed object CRC for %s",
2463 sha1_to_hex(sha1));
2464 mark_bad_packed_object(p, sha1);
896dca3a
RS
2465 data = NULL;
2466 goto out;
abe601bb
TR
2467 }
2468 }
2469
abe601bb
TR
2470 type = unpack_object_header(p, &w_curs, &curpos, &size);
2471 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2472 break;
2473
2474 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2475 if (!base_offset) {
2476 error("failed to validate delta base reference "
2477 "at offset %"PRIuMAX" from %s",
2478 (uintmax_t)curpos, p->pack_name);
2479 /* bail to phase 2, in hopes of recovery */
2480 data = NULL;
2481 break;
2482 }
2483
2484 /* push object, proceed to base */
2485 if (delta_stack_nr >= delta_stack_alloc
2486 && delta_stack == small_delta_stack) {
2487 delta_stack_alloc = alloc_nr(delta_stack_nr);
b32fa95f 2488 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
abe601bb
TR
2489 memcpy(delta_stack, small_delta_stack,
2490 sizeof(*delta_stack)*delta_stack_nr);
2491 } else {
2492 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2493 }
2494 i = delta_stack_nr++;
2495 delta_stack[i].obj_offset = obj_offset;
2496 delta_stack[i].curpos = curpos;
2497 delta_stack[i].size = size;
2498
2499 curpos = obj_offset = base_offset;
0e8189e2
NP
2500 }
2501
abe601bb
TR
2502 /* PHASE 2: handle the base */
2503 switch (type) {
eb32d236
NP
2504 case OBJ_OFS_DELTA:
2505 case OBJ_REF_DELTA:
abe601bb 2506 if (data)
ef1177d1 2507 die("BUG: unpack_entry: left loop at a valid delta");
4d703a1a 2508 break;
a733cb60 2509 case OBJ_COMMIT:
a733cb60 2510 case OBJ_TREE:
a733cb60 2511 case OBJ_BLOB:
a733cb60 2512 case OBJ_TAG:
abe601bb
TR
2513 if (!base_from_cache)
2514 data = unpack_compressed_entry(p, &w_curs, curpos, size);
4d703a1a 2515 break;
1f688557 2516 default:
8eca0b47
NP
2517 data = NULL;
2518 error("unknown object type %i at offset %"PRIuMAX" in %s",
abe601bb
TR
2519 type, (uintmax_t)obj_offset, p->pack_name);
2520 }
2521
2522 /* PHASE 3: apply deltas in order */
2523
2524 /* invariants:
2525 * 'data' holds the base data, or NULL if there was corruption
2526 */
2527 while (delta_stack_nr) {
2528 void *delta_data;
2529 void *base = data;
886ddf47 2530 void *external_base = NULL;
abe601bb
TR
2531 unsigned long delta_size, base_size = size;
2532 int i;
2533
2534 data = NULL;
2535
2536 if (base)
2537 add_delta_base_cache(p, obj_offset, base, base_size, type);
2538
2539 if (!base) {
2540 /*
2541 * We're probably in deep shit, but let's try to fetch
2542 * the required base anyway from another pack or loose.
2543 * This is costly but should happen only in the presence
2544 * of a corrupted pack, and is better than failing outright.
2545 */
2546 struct revindex_entry *revidx;
2547 const unsigned char *base_sha1;
2548 revidx = find_pack_revindex(p, obj_offset);
2549 if (revidx) {
2550 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2551 error("failed to read delta base object %s"
2552 " at offset %"PRIuMAX" from %s",
2553 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2554 p->pack_name);
2555 mark_bad_packed_object(p, base_sha1);
2556 base = read_object(base_sha1, &type, &base_size);
886ddf47 2557 external_base = base;
abe601bb
TR
2558 }
2559 }
2560
2561 i = --delta_stack_nr;
2562 obj_offset = delta_stack[i].obj_offset;
2563 curpos = delta_stack[i].curpos;
2564 delta_size = delta_stack[i].size;
2565
2566 if (!base)
2567 continue;
2568
2569 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2570
2571 if (!delta_data) {
2572 error("failed to unpack compressed delta "
2573 "at offset %"PRIuMAX" from %s",
2574 (uintmax_t)curpos, p->pack_name);
abe601bb 2575 data = NULL;
886ddf47 2576 free(external_base);
abe601bb
TR
2577 continue;
2578 }
2579
2580 data = patch_delta(base, base_size,
2581 delta_data, delta_size,
2582 &size);
1ee886c1
JK
2583
2584 /*
2585 * We could not apply the delta; warn the user, but keep going.
2586 * Our failure will be noticed either in the next iteration of
2587 * the loop, or if this is the final delta, in the caller when
2588 * we return NULL. Those code paths will take care of making
2589 * a more explicit warning and retrying with another copy of
2590 * the object.
2591 */
abe601bb 2592 if (!data)
1ee886c1 2593 error("failed to apply delta");
abe601bb 2594
4b8f772c 2595 free(delta_data);
886ddf47 2596 free(external_base);
1f688557 2597 }
abe601bb
TR
2598
2599 *final_type = type;
2600 *final_size = size;
2601
896dca3a 2602out:
03e79c88 2603 unuse_pack(&w_curs);
019d1e65
NTND
2604
2605 if (delta_stack != small_delta_stack)
2606 free(delta_stack);
2607
21666f1a 2608 return data;
1f688557
JH
2609}
2610
d079837e 2611const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 2612 uint32_t n)
9a217f2a 2613{
42873078 2614 const unsigned char *index = p->index_data;
d079837e
SP
2615 if (!index) {
2616 if (open_pack_index(p))
2617 return NULL;
2618 index = p->index_data;
2619 }
57059091 2620 if (n >= p->num_objects)
d72308e0 2621 return NULL;
74e34e1f
NP
2622 index += 4 * 256;
2623 if (p->index_version == 1) {
2624 return index + 24 * n + 4;
2625 } else {
2626 index += 8;
2627 return index + 20 * n;
2628 }
2629}
2630
47fe3f6e
JK
2631void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2632{
2633 const unsigned char *ptr = vptr;
2634 const unsigned char *start = p->index_data;
2635 const unsigned char *end = start + p->index_size;
2636 if (ptr < start)
7465feba 2637 die(_("offset before start of pack index for %s (corrupt index?)"),
47fe3f6e
JK
2638 p->pack_name);
2639 /* No need to check for underflow; .idx files must be at least 8 bytes */
2640 if (ptr >= end - 8)
7465feba 2641 die(_("offset beyond end of pack index for %s (truncated index?)"),
47fe3f6e
JK
2642 p->pack_name);
2643}
2644
99093238 2645off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
2646{
2647 const unsigned char *index = p->index_data;
2648 index += 4 * 256;
2649 if (p->index_version == 1) {
2650 return ntohl(*((uint32_t *)(index + 24 * n)));
2651 } else {
2652 uint32_t off;
2653 index += 8 + p->num_objects * (20 + 4);
2654 off = ntohl(*((uint32_t *)(index + 4 * n)));
2655 if (!(off & 0x80000000))
2656 return off;
2657 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
47fe3f6e 2658 check_pack_index_ptr(p, index);
74e34e1f
NP
2659 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2660 ntohl(*((uint32_t *)(index + 4)));
2661 }
9a217f2a
JH
2662}
2663
c4001d92 2664off_t find_pack_entry_one(const unsigned char *sha1,
43057304 2665 struct packed_git *p)
1f688557 2666{
42873078 2667 const uint32_t *level1_ofs = p->index_data;
42873078 2668 const unsigned char *index = p->index_data;
628522ec
JH
2669 unsigned hi, lo, stride;
2670 static int use_lookup = -1;
2671 static int debug_lookup = -1;
2672
2673 if (debug_lookup < 0)
2674 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 2675
d079837e
SP
2676 if (!index) {
2677 if (open_pack_index(p))
2678 return 0;
2679 level1_ofs = p->index_data;
2680 index = p->index_data;
2681 }
74e34e1f
NP
2682 if (p->index_version > 1) {
2683 level1_ofs += 2;
2684 index += 8;
2685 }
42873078 2686 index += 4 * 256;
74e34e1f
NP
2687 hi = ntohl(level1_ofs[*sha1]);
2688 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2689 if (p->index_version > 1) {
2690 stride = 20;
2691 } else {
2692 stride = 24;
2693 index += 4;
2694 }
2695
2696 if (debug_lookup)
6e1c2344 2697 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2698 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2699
2700 if (use_lookup < 0)
2701 use_lookup = !!getenv("GIT_USE_LOOKUP");
2702 if (use_lookup) {
2703 int pos = sha1_entry_pos(index, stride, 0,
2704 lo, hi, p->num_objects, sha1);
2705 if (pos < 0)
2706 return 0;
2707 return nth_packed_object_offset(p, pos);
2708 }
1f688557
JH
2709
2710 do {
74e34e1f 2711 unsigned mi = (lo + hi) / 2;
628522ec
JH
2712 int cmp = hashcmp(index + mi * stride, sha1);
2713
2714 if (debug_lookup)
2715 printf("lo %u hi %u rg %u mi %u\n",
2716 lo, hi, hi - lo, mi);
43057304 2717 if (!cmp)
74e34e1f 2718 return nth_packed_object_offset(p, mi);
1f688557
JH
2719 if (cmp > 0)
2720 hi = mi;
2721 else
2722 lo = mi+1;
2723 } while (lo < hi);
2724 return 0;
2725}
2726
4c080182 2727int is_pack_valid(struct packed_git *p)
d131b7af
SP
2728{
2729 /* An already open pack is known to be valid. */
2730 if (p->pack_fd != -1)
2731 return 1;
2732
2733 /* If the pack has one window completely covering the
2734 * file size, the pack is known to be valid even if
2735 * the descriptor is not currently open.
2736 */
2737 if (p->windows) {
2738 struct pack_window *w = p->windows;
2739
2740 if (!w->offset && w->len == p->pack_size)
2741 return 1;
2742 }
2743
2744 /* Force the pack to open to prove its valid. */
2745 return !open_packed_git(p);
2746}
2747
95099731
NTND
2748static int fill_pack_entry(const unsigned char *sha1,
2749 struct pack_entry *e,
2750 struct packed_git *p)
2751{
2752 off_t offset;
2753
2754 if (p->num_bad_objects) {
2755 unsigned i;
2756 for (i = 0; i < p->num_bad_objects; i++)
2757 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2758 return 0;
2759 }
2760
2761 offset = find_pack_entry_one(sha1, p);
2762 if (!offset)
2763 return 0;
2764
2765 /*
2766 * We are about to tell the caller where they can locate the
2767 * requested object. We better make sure the packfile is
2768 * still here and can be accessed before supplying that
2769 * answer, as it may have been deleted since the index was
2770 * loaded!
2771 */
319b678a 2772 if (!is_pack_valid(p))
95099731 2773 return 0;
95099731
NTND
2774 e->offset = offset;
2775 e->p = p;
2776 hashcpy(e->sha1, sha1);
2777 return 1;
2778}
2779
d40d535b
MH
2780/*
2781 * Iff a pack file contains the object named by sha1, return true and
2782 * store its location to e.
2783 */
4d6acb70 2784static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557 2785{
a73cdd21 2786 struct mru_entry *p;
43057304 2787
1f688557 2788 prepare_packed_git();
f7c22cc6
NP
2789 if (!packed_git)
2790 return 0;
1f688557 2791
a73cdd21
JK
2792 for (p = packed_git_mru->head; p; p = p->next) {
2793 if (fill_pack_entry(sha1, e, p->item)) {
2794 mru_mark(packed_git_mru, p);
1b1005d1
MH
2795 return 1;
2796 }
c01f51cc 2797 }
1f688557
JH
2798 return 0;
2799}
2800
a6080a0a 2801struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2802 struct packed_git *packs)
2803{
2804 struct packed_git *p;
bf592c50
DB
2805
2806 for (p = packs; p; p = p->next) {
43057304 2807 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2808 return p;
2809 }
2810 return NULL;
21666f1a 2811
bf592c50
DB
2812}
2813
052fe5ea 2814static int sha1_loose_object_info(const unsigned char *sha1,
46f03448
KN
2815 struct object_info *oi,
2816 int flags)
65c2e0c3 2817{
46f03448
KN
2818 int status = 0;
2819 unsigned long mapsize;
65c2e0c3 2820 void *map;
ef49a7a0 2821 git_zstream stream;
d65a16f6 2822 char hdr[32];
46f03448 2823 struct strbuf hdrbuf = STRBUF_INIT;
65c2e0c3 2824
5d642e75
JK
2825 if (oi->delta_base_sha1)
2826 hashclr(oi->delta_base_sha1);
2827
052fe5ea
JK
2828 /*
2829 * If we don't care about type or size, then we don't
4ef8d1dd
JH
2830 * need to look inside the object at all. Note that we
2831 * do not optimize out the stat call, even if the
2832 * caller doesn't care about the disk-size, since our
2833 * return value implicitly indicates whether the
2834 * object even exists.
052fe5ea 2835 */
46f03448 2836 if (!oi->typep && !oi->typename && !oi->sizep) {
771e7d57 2837 const char *path;
4ef8d1dd 2838 struct stat st;
771e7d57 2839 if (stat_sha1_file(sha1, &st, &path) < 0)
4ef8d1dd
JH
2840 return -1;
2841 if (oi->disk_sizep)
23c339c0 2842 *oi->disk_sizep = st.st_size;
052fe5ea
JK
2843 return 0;
2844 }
2845
bb6b8e4f 2846 map = map_sha1_file(sha1, &mapsize);
f0df4ed5 2847 if (!map)
dbea72a8 2848 return -1;
23c339c0
JK
2849 if (oi->disk_sizep)
2850 *oi->disk_sizep = mapsize;
46f03448
KN
2851 if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
2852 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2853 status = error("unable to unpack %s header with --allow-unknown-type",
2854 sha1_to_hex(sha1));
2855 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
36e4d74a
JH
2856 status = error("unable to unpack %s header",
2857 sha1_to_hex(sha1));
46f03448
KN
2858 if (status < 0)
2859 ; /* Do nothing */
2860 else if (hdrbuf.len) {
2861 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2862 status = error("unable to parse %s header with --allow-unknown-type",
2863 sha1_to_hex(sha1));
2864 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
36e4d74a 2865 status = error("unable to parse %s header", sha1_to_hex(sha1));
39c68542 2866 git_inflate_end(&stream);
65c2e0c3 2867 munmap(map, mapsize);
46f03448 2868 if (status && oi->typep)
23c339c0 2869 *oi->typep = status;
46f03448 2870 strbuf_release(&hdrbuf);
052fe5ea 2871 return 0;
65c2e0c3
JH
2872}
2873
de7b5d62 2874int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
f0df4ed5 2875{
c4d9986f 2876 struct cached_object *co;
f0df4ed5 2877 struct pack_entry e;
5b086407 2878 int rtype;
46f03448 2879 enum object_type real_type;
1f7117ef 2880 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
f0df4ed5 2881
1f7117ef 2882 co = find_cached_object(real);
c4d9986f 2883 if (co) {
5b086407
JK
2884 if (oi->typep)
2885 *(oi->typep) = co->type;
9a490590
JH
2886 if (oi->sizep)
2887 *(oi->sizep) = co->size;
161f00e7
JK
2888 if (oi->disk_sizep)
2889 *(oi->disk_sizep) = 0;
5d642e75
JK
2890 if (oi->delta_base_sha1)
2891 hashclr(oi->delta_base_sha1);
46f03448
KN
2892 if (oi->typename)
2893 strbuf_addstr(oi->typename, typename(co->type));
9a490590 2894 oi->whence = OI_CACHED;
5b086407 2895 return 0;
c4d9986f
NTND
2896 }
2897
1f7117ef 2898 if (!find_pack_entry(real, &e)) {
ddd63e64 2899 /* Most likely it's a loose object. */
46f03448 2900 if (!sha1_loose_object_info(real, oi, flags)) {
9a490590 2901 oi->whence = OI_LOOSE;
5b086407 2902 return 0;
9a490590 2903 }
ddd63e64
SG
2904
2905 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 2906 reprepare_packed_git();
1f7117ef 2907 if (!find_pack_entry(real, &e))
052fe5ea 2908 return -1;
f0df4ed5 2909 }
3d77d877 2910
46f03448
KN
2911 /*
2912 * packed_object_info() does not follow the delta chain to
2913 * find out the real type, unless it is given oi->typep.
2914 */
2915 if (oi->typename && !oi->typep)
2916 oi->typep = &real_type;
2917
23c339c0 2918 rtype = packed_object_info(e.p, e.offset, oi);
412916ee 2919 if (rtype < 0) {
1f7117ef 2920 mark_bad_packed_object(e.p, real);
46f03448
KN
2921 if (oi->typep == &real_type)
2922 oi->typep = NULL;
1f7117ef 2923 return sha1_object_info_extended(real, oi, 0);
5266d369
JH
2924 } else if (in_delta_base_cache(e.p, e.offset)) {
2925 oi->whence = OI_DBCACHED;
9a490590
JH
2926 } else {
2927 oi->whence = OI_PACKED;
2928 oi->u.packed.offset = e.offset;
2929 oi->u.packed.pack = e.p;
2930 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2931 rtype == OBJ_OFS_DELTA);
3d77d877 2932 }
46f03448
KN
2933 if (oi->typename)
2934 strbuf_addstr(oi->typename, typename(*oi->typep));
2935 if (oi->typep == &real_type)
2936 oi->typep = NULL;
3d77d877 2937
5b086407 2938 return 0;
f0df4ed5
JS
2939}
2940
3fc0dca9 2941/* returns enum object_type or negative */
9a490590
JH
2942int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2943{
5b086407 2944 enum object_type type;
27b5c1a0 2945 struct object_info oi = OBJECT_INFO_INIT;
9a490590 2946
5b086407 2947 oi.typep = &type;
9a490590 2948 oi.sizep = sizep;
de7b5d62 2949 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
5b086407
JK
2950 return -1;
2951 return type;
9a490590
JH
2952}
2953
21666f1a
NP
2954static void *read_packed_sha1(const unsigned char *sha1,
2955 enum object_type *type, unsigned long *size)
1f688557
JH
2956{
2957 struct pack_entry e;
8eca0b47 2958 void *data;
1f688557 2959
cd673c1f 2960 if (!find_pack_entry(sha1, &e))
1f688557 2961 return NULL;
85fe35ab 2962 data = cache_or_unpack_entry(e.p, e.offset, size, type);
8eca0b47
NP
2963 if (!data) {
2964 /*
2965 * We're probably in deep shit, but let's try to fetch
2966 * the required object anyway from another pack or loose.
2967 * This should happen only in the presence of a corrupted
2968 * pack, and is better than failing outright.
2969 */
2970 error("failed to read object %s at offset %"PRIuMAX" from %s",
2971 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2972 mark_bad_packed_object(e.p, sha1);
ac939109 2973 data = read_object(sha1, type, size);
8eca0b47
NP
2974 }
2975 return data;
1f688557
JH
2976}
2977
21666f1a
NP
2978int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2979 unsigned char *sha1)
d66b37bb
JH
2980{
2981 struct cached_object *co;
2982
21666f1a 2983 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2984 if (has_sha1_file(sha1) || find_cached_object(sha1))
2985 return 0;
c7353967 2986 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
d66b37bb
JH
2987 co = &cached_objects[cached_object_nr++];
2988 co->size = len;
21666f1a 2989 co->type = type;
efa13f7b
JH
2990 co->buf = xmalloc(len);
2991 memcpy(co->buf, buf, len);
d66b37bb
JH
2992 hashcpy(co->sha1, sha1);
2993 return 0;
2994}
2995
c2c5b270
CC
2996static void *read_object(const unsigned char *sha1, enum object_type *type,
2997 unsigned long *size)
0fcfd160
LT
2998{
2999 unsigned long mapsize;
3000 void *map, *buf;
d66b37bb
JH
3001 struct cached_object *co;
3002
3003 co = find_cached_object(sha1);
3004 if (co) {
21666f1a 3005 *type = co->type;
d66b37bb 3006 *size = co->size;
182af834 3007 return xmemdupz(co->buf, co->size);
d66b37bb 3008 }
0fcfd160 3009
8276c007
PE
3010 buf = read_packed_sha1(sha1, type, size);
3011 if (buf)
3012 return buf;
bb6b8e4f 3013 map = map_sha1_file(sha1, &mapsize);
0fcfd160 3014 if (map) {
7efbff75 3015 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
3016 munmap(map, mapsize);
3017 return buf;
3018 }
637cdd9d 3019 reprepare_packed_git();
8276c007 3020 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
3021}
3022
b6c4cecc
JH
3023/*
3024 * This function dies on corrupt objects; the callers who want to
3025 * deal with them should arrange to call read_object() and give error
3026 * messages themselves.
3027 */
5bf29b95
JH
3028void *read_sha1_file_extended(const unsigned char *sha1,
3029 enum object_type *type,
3030 unsigned long *size,
3031 unsigned flag)
ac939109 3032{
3ba7a065 3033 void *data;
b6c4cecc 3034 const struct packed_git *p;
771e7d57
JK
3035 const char *path;
3036 struct stat st;
bf93eea0 3037 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
b6c4cecc 3038
3ba7a065
JH
3039 errno = 0;
3040 data = read_object(repl, type, size);
4bbf5a26 3041 if (data)
b6c4cecc 3042 return data;
68095570 3043
25f3af3f 3044 if (errno && errno != ENOENT)
3ba7a065
JH
3045 die_errno("failed to read object %s", sha1_to_hex(sha1));
3046
68095570 3047 /* die if we replaced an object with one that does not exist */
b6c4cecc 3048 if (repl != sha1)
68095570
CC
3049 die("replacement %s not found for %s",
3050 sha1_to_hex(repl), sha1_to_hex(sha1));
3051
771e7d57 3052 if (!stat_sha1_file(repl, &st, &path))
b6c4cecc
JH
3053 die("loose object %s (stored in %s) is corrupt",
3054 sha1_to_hex(repl), path);
68095570 3055
b6c4cecc
JH
3056 if ((p = has_packed_and_bad(repl)) != NULL)
3057 die("packed object %s (stored in %s) is corrupt",
3058 sha1_to_hex(repl), p->pack_name);
f5552aee 3059
b6c4cecc 3060 return NULL;
ac939109
NP
3061}
3062
40469ee9 3063void *read_object_with_reference(const unsigned char *sha1,
21666f1a 3064 const char *required_type_name,
40469ee9
JH
3065 unsigned long *size,
3066 unsigned char *actual_sha1_return)
f4913f91 3067{
21666f1a 3068 enum object_type type, required_type;
f4913f91
JH
3069 void *buffer;
3070 unsigned long isize;
40469ee9 3071 unsigned char actual_sha1[20];
f4913f91 3072
21666f1a 3073 required_type = type_from_string(required_type_name);
e702496e 3074 hashcpy(actual_sha1, sha1);
40469ee9
JH
3075 while (1) {
3076 int ref_length = -1;
3077 const char *ref_type = NULL;
f4913f91 3078
21666f1a 3079 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
3080 if (!buffer)
3081 return NULL;
21666f1a 3082 if (type == required_type) {
40469ee9
JH
3083 *size = isize;
3084 if (actual_sha1_return)
e702496e 3085 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
3086 return buffer;
3087 }
3088 /* Handle references */
21666f1a 3089 else if (type == OBJ_COMMIT)
40469ee9 3090 ref_type = "tree ";
21666f1a 3091 else if (type == OBJ_TAG)
40469ee9
JH
3092 ref_type = "object ";
3093 else {
3094 free(buffer);
3095 return NULL;
3096 }
3097 ref_length = strlen(ref_type);
f4913f91 3098
50974ec9
MK
3099 if (ref_length + 40 > isize ||
3100 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 3101 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
3102 free(buffer);
3103 return NULL;
3104 }
1cf58e72 3105 free(buffer);
40469ee9
JH
3106 /* Now we have the ID of the referred-to object in
3107 * actual_sha1. Check again. */
f4913f91 3108 }
f4913f91
JH
3109}
3110
ce9fbf16 3111static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 3112 const char *type, unsigned char *sha1,
d65a16f6 3113 char *hdr, int *hdrlen)
d410c0f5 3114{
9126f009 3115 git_SHA_CTX c;
d410c0f5
JH
3116
3117 /* Generate the header */
ef1286d3 3118 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
d410c0f5
JH
3119
3120 /* Sha1.. */
9126f009
NP
3121 git_SHA1_Init(&c);
3122 git_SHA1_Update(&c, hdr, *hdrlen);
3123 git_SHA1_Update(&c, buf, len);
3124 git_SHA1_Final(sha1, &c);
d410c0f5
JH
3125}
3126
230f1322 3127/*
5a688fe4 3128 * Move the just written object into its final resting place.
230f1322 3129 */
cb5add58 3130int finalize_object_file(const char *tmpfile, const char *filename)
230f1322 3131{
e32c0a9c 3132 int ret = 0;
5a688fe4 3133
348df166 3134 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
3135 goto try_rename;
3136 else if (link(tmpfile, filename))
e32c0a9c 3137 ret = errno;
7ebb6fca
LT
3138
3139 /*
3140 * Coda hack - coda doesn't like cross-directory links,
3141 * so we fall back to a rename, which will mean that it
3142 * won't be able to check collisions, but that's not a
3143 * big deal.
3144 *
3145 * The same holds for FAT formatted media.
3146 *
3be1f18e 3147 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
3148 * left to unlink.
3149 */
3150 if (ret && ret != EEXIST) {
be66a6c4 3151 try_rename:
7ebb6fca 3152 if (!rename(tmpfile, filename))
3be1f18e 3153 goto out;
9e48b389 3154 ret = errno;
230f1322 3155 }
691f1a28 3156 unlink_or_warn(tmpfile);
230f1322
LT
3157 if (ret) {
3158 if (ret != EEXIST) {
7616c6ca 3159 return error_errno("unable to write sha1 filename %s", filename);
230f1322
LT
3160 }
3161 /* FIXME!!! Collision check here ? */
3162 }
3163
3be1f18e 3164out:
5256b006 3165 if (adjust_shared_perm(filename))
5a688fe4 3166 return error("unable to set permission to '%s'", filename);
230f1322
LT
3167 return 0;
3168}
3169
4d548150
LT
3170static int write_buffer(int fd, const void *buf, size_t len)
3171{
d34cf19b 3172 if (write_in_full(fd, buf, len) < 0)
7616c6ca 3173 return error_errno("file write error");
4d548150
LT
3174 return 0;
3175}
3176
ce9fbf16 3177int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
3178 unsigned char *sha1)
3179{
d65a16f6 3180 char hdr[32];
ef1286d3 3181 int hdrlen = sizeof(hdr);
abdc3fc8
RS
3182 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3183 return 0;
3184}
3185
e9039dd3
LT
3186/* Finalize a file on disk, and close it. */
3187static void close_sha1_file(int fd)
3188{
aafe9fba
LT
3189 if (fsync_object_files)
3190 fsync_or_die(fd, "sha1 file");
e9039dd3 3191 if (close(fd) != 0)
d824cbba 3192 die_errno("error when closing sha1 file");
e9039dd3
LT
3193}
3194
5723fe7e
LT
3195/* Size of directory component, including the ending '/' */
3196static inline int directory_size(const char *filename)
3197{
3198 const char *s = strrchr(filename, '/');
3199 if (!s)
3200 return 0;
3201 return s - filename + 1;
3202}
3203
3204/*
3205 * This creates a temporary file in the same directory as the final
3206 * 'filename'
3207 *
3208 * We want to avoid cross-directory filename renames, because those
3209 * can have problems on various filesystems (FAT, NFS, Coda).
3210 */
d4b3d11a 3211static int create_tmpfile(struct strbuf *tmp, const char *filename)
5723fe7e
LT
3212{
3213 int fd, dirlen = directory_size(filename);
3214
d4b3d11a
JK
3215 strbuf_reset(tmp);
3216 strbuf_add(tmp, filename, dirlen);
3217 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3218 fd = git_mkstemp_mode(tmp->buf, 0444);
cbacbf4e 3219 if (fd < 0 && dirlen && errno == ENOENT) {
d4b3d11a
JK
3220 /*
3221 * Make sure the directory exists; note that the contents
3222 * of the buffer are undefined after mkstemp returns an
3223 * error, so we have to rewrite the whole buffer from
3224 * scratch.
3225 */
3226 strbuf_reset(tmp);
3227 strbuf_add(tmp, filename, dirlen - 1);
3228 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
b2476a60 3229 return -1;
d4b3d11a 3230 if (adjust_shared_perm(tmp->buf))
5723fe7e
LT
3231 return -1;
3232
3233 /* Try again */
d4b3d11a
JK
3234 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3235 fd = git_mkstemp_mode(tmp->buf, 0444);
5723fe7e
LT
3236 }
3237 return fd;
3238}
3239
bbac7311 3240static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 3241 const void *buf, unsigned long len, time_t mtime)
0fcfd160 3242{
915308b1 3243 int fd, ret;
9892beba 3244 unsigned char compressed[4096];
ef49a7a0 3245 git_zstream stream;
748af44c
NP
3246 git_SHA_CTX c;
3247 unsigned char parano_sha1[20];
d4b3d11a 3248 static struct strbuf tmp_file = STRBUF_INIT;
30d6c6ea 3249 const char *filename = sha1_file_name(sha1);
a44c9a5e 3250
d4b3d11a 3251 fd = create_tmpfile(&tmp_file, filename);
aac17941 3252 if (fd < 0) {
35243577 3253 if (errno == EACCES)
82247e9b 3254 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 3255 else
7616c6ca 3256 return error_errno("unable to create temporary file");
aac17941
LT
3257 }
3258
0fcfd160 3259 /* Set it up */
55bb5c91 3260 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 3261 stream.next_out = compressed;
9892beba 3262 stream.avail_out = sizeof(compressed);
748af44c 3263 git_SHA1_Init(&c);
a44c9a5e
LT
3264
3265 /* First header.. */
d65a16f6 3266 stream.next_in = (unsigned char *)hdr;
a44c9a5e 3267 stream.avail_in = hdrlen;
55bb5c91
JH
3268 while (git_deflate(&stream, 0) == Z_OK)
3269 ; /* nothing */
748af44c 3270 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
3271
3272 /* Then the data itself.. */
c00e657d 3273 stream.next_in = (void *)buf;
a44c9a5e 3274 stream.avail_in = len;
9892beba 3275 do {
748af44c 3276 unsigned char *in0 = stream.next_in;
55bb5c91 3277 ret = git_deflate(&stream, Z_FINISH);
748af44c 3278 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
3279 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3280 die("unable to write sha1 file");
3281 stream.next_out = compressed;
3282 stream.avail_out = sizeof(compressed);
3283 } while (ret == Z_OK);
3284
ac54c277
LT
3285 if (ret != Z_STREAM_END)
3286 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 3287 ret = git_deflate_end_gently(&stream);
ac54c277
LT
3288 if (ret != Z_OK)
3289 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
3290 git_SHA1_Final(parano_sha1, &c);
3291 if (hashcmp(sha1, parano_sha1) != 0)
3292 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 3293
e9039dd3 3294 close_sha1_file(fd);
0fcfd160 3295
bbac7311
NP
3296 if (mtime) {
3297 struct utimbuf utb;
3298 utb.actime = mtime;
3299 utb.modtime = mtime;
d4b3d11a 3300 if (utime(tmp_file.buf, &utb) < 0)
7616c6ca 3301 warning_errno("failed utime() on %s", tmp_file.buf);
bbac7311
NP
3302 }
3303
d4b3d11a 3304 return finalize_object_file(tmp_file.buf, filename);
0fcfd160 3305}
8237b185 3306
33d4221c
JK
3307static int freshen_loose_object(const unsigned char *sha1)
3308{
3309 return check_and_freshen(sha1, 1);
3310}
3311
3312static int freshen_packed_object(const unsigned char *sha1)
3313{
3314 struct pack_entry e;
ee1c6c34
JK
3315 if (!find_pack_entry(sha1, &e))
3316 return 0;
3317 if (e.p->freshened)
3318 return 1;
3319 if (!freshen_file(e.p->pack_name))
3320 return 0;
3321 e.p->freshened = 1;
3322 return 1;
33d4221c
JK
3323}
3324
1427a7ff 3325int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
bbac7311 3326{
bbac7311 3327 char hdr[32];
ef1286d3 3328 int hdrlen = sizeof(hdr);
bbac7311
NP
3329
3330 /* Normally if we have it in the pack then we do not bother writing
3331 * it out into .git/objects/??/?{38} file.
3332 */
3333 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
b5f52f37 3334 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
bbac7311
NP
3335 return 0;
3336 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3337}
3338
0c3db67c
ES
3339int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3340 unsigned char *sha1, unsigned flags)
3341{
3342 char *header;
3343 int hdrlen, status = 0;
3344
3345 /* type string, SP, %lu of the length plus NUL must fit this */
ef1286d3
JK
3346 hdrlen = strlen(type) + 32;
3347 header = xmalloc(hdrlen);
0c3db67c
ES
3348 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3349
3350 if (!(flags & HASH_WRITE_OBJECT))
3351 goto cleanup;
051086b9 3352 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
0c3db67c
ES
3353 goto cleanup;
3354 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3355
3356cleanup:
3357 free(header);
3358 return status;
3359}
3360
bbac7311
NP
3361int force_object_loose(const unsigned char *sha1, time_t mtime)
3362{
bbac7311
NP
3363 void *buf;
3364 unsigned long len;
3365 enum object_type type;
3366 char hdr[32];
3367 int hdrlen;
1fb23e65 3368 int ret;
bbac7311 3369
c529d75a 3370 if (has_loose_object(sha1))
bbac7311
NP
3371 return 0;
3372 buf = read_packed_sha1(sha1, &type, &len);
3373 if (!buf)
3374 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
ef1286d3 3375 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
1fb23e65
BS
3376 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3377 free(buf);
3378
3379 return ret;
bbac7311
NP
3380}
3381
bf592c50
DB
3382int has_pack_index(const unsigned char *sha1)
3383{
3384 struct stat st;
3385 if (stat(sha1_pack_index_name(sha1), &st))
3386 return 0;
3387 return 1;
bf592c50
DB
3388}
3389
cd673c1f
JH
3390int has_sha1_pack(const unsigned char *sha1)
3391{
3392 struct pack_entry e;
3393 return find_pack_entry(sha1, &e);
3394}
3395
0eeb077b 3396int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
8237b185 3397{
1f688557
JH
3398 struct pack_entry e;
3399
cd673c1f 3400 if (find_pack_entry(sha1, &e))
1f688557 3401 return 1;
45e8a748
JK
3402 if (has_loose_object(sha1))
3403 return 1;
0eeb077b
JK
3404 if (flags & HAS_SHA1_QUICK)
3405 return 0;
45e8a748
JK
3406 reprepare_packed_git();
3407 return find_pack_entry(sha1, &e);
b419aa25 3408}
3409
3410int has_object_file(const struct object_id *oid)
3411{
3412 return has_sha1_file(oid->hash);
8237b185 3413}
74400e71 3414
5827a035
JK
3415int has_object_file_with_flags(const struct object_id *oid, int flags)
3416{
3417 return has_sha1_file_with_flags(oid->hash, flags);
3418}
3419
c879daa2
NTND
3420static void check_tree(const void *buf, size_t size)
3421{
3422 struct tree_desc desc;
3423 struct name_entry entry;
3424
3425 init_tree_desc(&desc, buf, size);
3426 while (tree_entry(&desc, &entry))
3427 /* do nothing
3428 * tree_entry() will die() on malformed entries */
3429 ;
3430}
3431
3432static void check_commit(const void *buf, size_t size)
3433{
3434 struct commit c;
3435 memset(&c, 0, sizeof(c));
3436 if (parse_commit_buffer(&c, buf, size))
3437 die("corrupt commit");
3438}
3439
3440static void check_tag(const void *buf, size_t size)
3441{
3442 struct tag t;
3443 memset(&t, 0, sizeof(t));
3444 if (parse_tag_buffer(&t, buf, size))
3445 die("corrupt tag");
3446}
3447
43df4f86 3448static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
3449 enum object_type type,
3450 const char *path, unsigned flags)
e7332f96 3451{
6c510bee 3452 int ret, re_allocated = 0;
c4ce46fc 3453 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 3454
7672db20 3455 if (!type)
edaec3fb 3456 type = OBJ_BLOB;
6c510bee
LT
3457
3458 /*
3459 * Convert blobs to git internal format
3460 */
43df4f86 3461 if ((type == OBJ_BLOB) && path) {
f285a2d7 3462 struct strbuf nbuf = STRBUF_INIT;
21e5ad50 3463 if (convert_to_git(path, buf, size, &nbuf,
5e12e78e 3464 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 3465 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
3466 re_allocated = 1;
3467 }
3468 }
c4ce46fc 3469 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
3470 if (type == OBJ_TREE)
3471 check_tree(buf, size);
3472 if (type == OBJ_COMMIT)
3473 check_commit(buf, size);
3474 if (type == OBJ_TAG)
3475 check_tag(buf, size);
3476 }
6c510bee 3477
7672db20 3478 if (write_object)
edaec3fb 3479 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 3480 else
edaec3fb 3481 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 3482 if (re_allocated)
6c510bee 3483 free(buf);
43df4f86
DP
3484 return ret;
3485}
3486
9035d75a
SP
3487static int index_stream_convert_blob(unsigned char *sha1, int fd,
3488 const char *path, unsigned flags)
3489{
3490 int ret;
3491 const int write_object = flags & HASH_WRITE_OBJECT;
3492 struct strbuf sbuf = STRBUF_INIT;
3493
3494 assert(path);
3495 assert(would_convert_to_git_filter_fd(path));
3496
3497 convert_to_git_filter_fd(path, fd, &sbuf,
3498 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3499
3500 if (write_object)
3501 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3502 sha1);
3503 else
3504 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3505 sha1);
3506 strbuf_release(&sbuf);
3507 return ret;
3508}
3509
7b41e1e1
JH
3510static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3511 const char *path, unsigned flags)
3512{
3513 struct strbuf sbuf = STRBUF_INIT;
3514 int ret;
3515
3516 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3517 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3518 else
3519 ret = -1;
3520 strbuf_release(&sbuf);