add generic most-recently-used list
[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"
0fcfd160 26
144bde78
LT
27#ifndef O_NOATIME
28#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
29#define O_NOATIME 01000000
30#else
31#define O_NOATIME 0
32#endif
33#endif
34
28bd70d8
JN
35#define SZ_FMT PRIuMAX
36static inline uintmax_t sz_fmt(size_t s) { return s; }
e05db0fd 37
96f1e58f 38const unsigned char null_sha1[20];
3e56e724 39const struct object_id null_oid;
88cd621d 40
c597ba80
NTND
41/*
42 * This is meant to hold a *small* number of objects that you would
43 * want read_sha1_file() to be able to return, but yet you do not want
44 * to write them into the object store (e.g. a browse-only
45 * application).
46 */
47static struct cached_object {
48 unsigned char sha1[20];
49 enum object_type type;
50 void *buf;
51 unsigned long size;
52} *cached_objects;
53static int cached_object_nr, cached_object_alloc;
54
55static struct cached_object empty_tree = {
dab0d410 56 EMPTY_TREE_SHA1_BIN_LITERAL,
c597ba80
NTND
57 OBJ_TREE,
58 "",
59 0
60};
61
1b1005d1
MH
62/*
63 * A pointer to the last packed_git in which an object was found.
64 * When an object is sought, we look in this packfile first, because
65 * objects that are looked up at similar times are often in the same
66 * packfile as one another.
67 */
c01f51cc
NTND
68static struct packed_git *last_found_pack;
69
c597ba80
NTND
70static struct cached_object *find_cached_object(const unsigned char *sha1)
71{
72 int i;
73 struct cached_object *co = cached_objects;
74
75 for (i = 0; i < cached_object_nr; i++, co++) {
76 if (!hashcmp(co->sha1, sha1))
77 return co;
78 }
79 if (!hashcmp(sha1, empty_tree.sha1))
80 return &empty_tree;
81 return NULL;
82}
83
90a6464b
JH
84int mkdir_in_gitdir(const char *path)
85{
86 if (mkdir(path, 0777)) {
87 int saved_errno = errno;
88 struct stat st;
89 struct strbuf sb = STRBUF_INIT;
90
91 if (errno != EEXIST)
92 return -1;
93 /*
94 * Are we looking at a path in a symlinked worktree
95 * whose original repository does not yet have it?
96 * e.g. .git/rr-cache pointing at its original
97 * repository in which the user hasn't performed any
98 * conflict resolution yet?
99 */
100 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
101 strbuf_readlink(&sb, path, st.st_size) ||
102 !is_absolute_path(sb.buf) ||
103 mkdir(sb.buf, 0777)) {
104 strbuf_release(&sb);
105 errno = saved_errno;
106 return -1;
107 }
108 strbuf_release(&sb);
109 }
110 return adjust_shared_perm(path);
111}
112
0be0521b 113enum scld_error safe_create_leading_directories(char *path)
b2cb9425 114{
26c8ae2a 115 char *next_component = path + offset_1st_component(path);
0be0521b 116 enum scld_error ret = SCLD_OK;
67d42212 117
0be0521b 118 while (ret == SCLD_OK && next_component) {
f0502332 119 struct stat st;
0f527403 120 char *slash = next_component, slash_character;
f0502332 121
0f527403
MH
122 while (*slash && !is_dir_sep(*slash))
123 slash++;
124
125 if (!*slash)
b2cb9425 126 break;
bf10cf70 127
26c8ae2a 128 next_component = slash + 1;
0f527403 129 while (is_dir_sep(*next_component))
bf10cf70 130 next_component++;
26c8ae2a 131 if (!*next_component)
5f0bdf50 132 break;
831651fd 133
0f527403 134 slash_character = *slash;
831651fd 135 *slash = '\0';
67d42212
JR
136 if (!stat(path, &st)) {
137 /* path exists */
9e6f885d 138 if (!S_ISDIR(st.st_mode))
0be0521b 139 ret = SCLD_EXISTS;
53a39721 140 } else if (mkdir(path, 0777)) {
928734d9 141 if (errno == EEXIST &&
9e6f885d 142 !stat(path, &st) && S_ISDIR(st.st_mode))
928734d9 143 ; /* somebody created it since we checked */
18d37e86
MH
144 else if (errno == ENOENT)
145 /*
146 * Either mkdir() failed because
147 * somebody just pruned the containing
148 * directory, or stat() failed because
149 * the file that was in our way was
150 * just removed. Either way, inform
151 * the caller that it might be worth
152 * trying again:
153 */
154 ret = SCLD_VANISHED;
9e6f885d 155 else
0be0521b 156 ret = SCLD_FAILED;
53a39721 157 } else if (adjust_shared_perm(path)) {
0be0521b 158 ret = SCLD_PERMS;
457f06d6 159 }
0f527403 160 *slash = slash_character;
b2cb9425 161 }
9e6f885d 162 return ret;
b2cb9425 163}
723c31fe 164
0be0521b 165enum scld_error safe_create_leading_directories_const(const char *path)
8e21d63b
JK
166{
167 /* path points to cache entries, so xstrdup before messing with it */
168 char *buf = xstrdup(path);
0be0521b 169 enum scld_error result = safe_create_leading_directories(buf);
8e21d63b
JK
170 free(buf);
171 return result;
172}
173
ace1534d
JH
174static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
175{
176 int i;
177 for (i = 0; i < 20; i++) {
178 static char hex[] = "0123456789abcdef";
179 unsigned int val = sha1[i];
180 char *pos = pathbuf + i*2 + (i > 0);
181 *pos++ = hex[val >> 4];
182 *pos = hex[val & 0xf];
183 }
184}
185
30d6c6ea 186const char *sha1_file_name(const unsigned char *sha1)
0fcfd160 187{
560fb6a1
JK
188 static char buf[PATH_MAX];
189 const char *objdir;
190 int len;
0fcfd160 191
560fb6a1
JK
192 objdir = get_object_directory();
193 len = strlen(objdir);
194
195 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
196 if (len + 43 > PATH_MAX)
197 die("insanely long object directory %s", objdir);
198 memcpy(buf, objdir, len);
199 buf[len] = '/';
200 buf[len+3] = '/';
201 buf[len+42] = '\0';
202 fill_sha1_path(buf + len + 1, sha1);
203 return buf;
0fcfd160
LT
204}
205
d40d535b
MH
206/*
207 * Return the name of the pack or index file with the specified sha1
208 * in its filename. *base and *name are scratch space that must be
209 * provided by the caller. which should be "pack" or "idx".
210 */
633f43e1 211static char *sha1_get_pack_name(const unsigned char *sha1,
ac5190cc
JK
212 struct strbuf *buf,
213 const char *which)
bf592c50 214{
ac5190cc
JK
215 strbuf_reset(buf);
216 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
217 sha1_to_hex(sha1), which);
218 return buf->buf;
bf592c50
DB
219}
220
633f43e1 221char *sha1_pack_name(const unsigned char *sha1)
bf592c50 222{
ac5190cc
JK
223 static struct strbuf buf = STRBUF_INIT;
224 return sha1_get_pack_name(sha1, &buf, "pack");
633f43e1 225}
bf592c50 226
633f43e1
HO
227char *sha1_pack_index_name(const unsigned char *sha1)
228{
ac5190cc
JK
229 static struct strbuf buf = STRBUF_INIT;
230 return sha1_get_pack_name(sha1, &buf, "idx");
bf592c50
DB
231}
232
d5a63b99
JH
233struct alternate_object_database *alt_odb_list;
234static struct alternate_object_database **alt_odb_tail;
ace1534d 235
ddd5d056
JH
236/*
237 * Prepare alternate object database registry.
d5a63b99
JH
238 *
239 * The variable alt_odb_list points at the list of struct
240 * alternate_object_database. The elements on this list come from
241 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
242 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
243 * whose contents is similar to that environment variable but can be
244 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
245 * contains "/the/directory/corresponding/to/.git/objects/...", while
246 * its name points just after the slash at the end of ".git/objects/"
247 * in the example above, and has enough space to hold 40-byte hex
248 * SHA1, an extra slash for the first level indirection, and the
249 * terminating NUL.
ddd5d056 250 */
539e7506
EK
251static int link_alt_odb_entry(const char *entry, const char *relative_base,
252 int depth, const char *normalized_objdir)
ace1534d 253{
c2f493a4
MW
254 struct alternate_object_database *ent;
255 struct alternate_object_database *alt;
50a6c8ef 256 size_t pfxlen, entlen;
5bdf0a84 257 struct strbuf pathbuf = STRBUF_INIT;
d5a63b99 258
85dadc38 259 if (!is_absolute_path(entry) && relative_base) {
5bdf0a84
HW
260 strbuf_addstr(&pathbuf, real_path(relative_base));
261 strbuf_addch(&pathbuf, '/');
c2f493a4 262 }
6eac50d8 263 strbuf_addstr(&pathbuf, entry);
c2f493a4 264
5bdf0a84
HW
265 normalize_path_copy(pathbuf.buf, pathbuf.buf);
266
267 pfxlen = strlen(pathbuf.buf);
268
269 /*
270 * The trailing slash after the directory name is given by
271 * this function at the end. Remove duplicates.
272 */
273 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
274 pfxlen -= 1;
275
50a6c8ef
JK
276 entlen = st_add(pfxlen, 43); /* '/' + 2 hex + '/' + 38 hex + NUL */
277 ent = xmalloc(st_add(sizeof(*ent), entlen));
5bdf0a84
HW
278 memcpy(ent->base, pathbuf.buf, pfxlen);
279 strbuf_release(&pathbuf);
c2f493a4
MW
280
281 ent->name = ent->base + pfxlen + 1;
282 ent->base[pfxlen + 3] = '/';
283 ent->base[pfxlen] = ent->base[entlen-1] = 0;
284
285 /* Detect cases where alternate disappeared */
90b4a71c 286 if (!is_directory(ent->base)) {
c2f493a4
MW
287 error("object directory %s does not exist; "
288 "check .git/objects/info/alternates.",
289 ent->base);
290 free(ent);
291 return -1;
292 }
293
294 /* Prevent the common mistake of listing the same
295 * thing twice, or object directory itself.
296 */
297 for (alt = alt_odb_list; alt; alt = alt->next) {
80b47854
RS
298 if (pfxlen == alt->name - alt->base - 1 &&
299 !memcmp(ent->base, alt->base, pfxlen)) {
c2f493a4
MW
300 free(ent);
301 return -1;
302 }
303 }
ba0897e6 304 if (!fspathcmp(ent->base, normalized_objdir)) {
c2f493a4
MW
305 free(ent);
306 return -1;
307 }
308
309 /* add the alternate entry */
310 *alt_odb_tail = ent;
311 alt_odb_tail = &(ent->next);
312 ent->next = NULL;
313
314 /* recursively add alternates */
315 read_info_alternates(ent->base, depth + 1);
316
317 ent->base[pfxlen] = '/';
318
319 return 0;
320}
321
c5950164 322static void link_alt_odb_entries(const char *alt, int len, int sep,
c2f493a4
MW
323 const char *relative_base, int depth)
324{
6eac50d8
MH
325 struct string_list entries = STRING_LIST_INIT_NODUP;
326 char *alt_copy;
327 int i;
539e7506 328 struct strbuf objdirbuf = STRBUF_INIT;
c2f493a4
MW
329
330 if (depth > 5) {
331 error("%s: ignoring alternate object stores, nesting too deep.",
332 relative_base);
333 return;
334 }
335
f655651e 336 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
539e7506
EK
337 normalize_path_copy(objdirbuf.buf, objdirbuf.buf);
338
c5950164 339 alt_copy = xmemdupz(alt, len);
6eac50d8
MH
340 string_list_split_in_place(&entries, alt_copy, sep, -1);
341 for (i = 0; i < entries.nr; i++) {
342 const char *entry = entries.items[i].string;
343 if (entry[0] == '\0' || entry[0] == '#')
9577e7e3 344 continue;
6eac50d8
MH
345 if (!is_absolute_path(entry) && depth) {
346 error("%s: ignoring relative alternate object store %s",
347 relative_base, entry);
348 } else {
539e7506 349 link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf);
9577e7e3 350 }
9577e7e3 351 }
6eac50d8
MH
352 string_list_clear(&entries, 0);
353 free(alt_copy);
539e7506 354 strbuf_release(&objdirbuf);
d5a63b99
JH
355}
356
5e73633d 357void read_info_alternates(const char * relative_base, int depth)
d5a63b99 358{
9577e7e3 359 char *map;
dc49cd76 360 size_t mapsz;
d5a63b99 361 struct stat st;
5015f01c 362 char *path;
c2f493a4 363 int fd;
d5a63b99 364
5015f01c 365 path = xstrfmt("%s/info/alternates", relative_base);
f4e51683 366 fd = git_open_noatime(path);
5015f01c 367 free(path);
d5a63b99
JH
368 if (fd < 0)
369 return;
370 if (fstat(fd, &st) || (st.st_size == 0)) {
371 close(fd);
9a217f2a 372 return;
ace1534d 373 }
dc49cd76
SP
374 mapsz = xsize_t(st.st_size);
375 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 376 close(fd);
d5a63b99 377
c5950164 378 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
c2f493a4 379
dc49cd76 380 munmap(map, mapsz);
ace1534d
JH
381}
382
bef70b22
DB
383void add_to_alternates_file(const char *reference)
384{
385 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
77b9b1d1
JK
386 char *alts = git_pathdup("objects/info/alternates");
387 FILE *in, *out;
388
389 hold_lock_file_for_update(lock, alts, LOCK_DIE_ON_ERROR);
390 out = fdopen_lock_file(lock, "w");
391 if (!out)
392 die_errno("unable to fdopen alternates lockfile");
393
394 in = fopen(alts, "r");
395 if (in) {
396 struct strbuf line = STRBUF_INIT;
397 int found = 0;
398
3f163962 399 while (strbuf_getline(&line, in) != EOF) {
77b9b1d1
JK
400 if (!strcmp(reference, line.buf)) {
401 found = 1;
402 break;
403 }
404 fprintf_or_die(out, "%s\n", line.buf);
405 }
406
407 strbuf_release(&line);
408 fclose(in);
409
410 if (found) {
411 rollback_lock_file(lock);
412 lock = NULL;
413 }
414 }
415 else if (errno != ENOENT)
416 die_errno("unable to read alternates file");
417
418 if (lock) {
419 fprintf_or_die(out, "%s\n", reference);
420 if (commit_lock_file(lock))
421 die_errno("unable to move new alternates file into place");
422 if (alt_odb_tail)
423 link_alt_odb_entries(reference, strlen(reference), '\n', NULL, 0);
424 }
425 free(alts);
bef70b22
DB
426}
427
fe1b2268 428int foreach_alt_odb(alt_odb_fn fn, void *cb)
d79796bc
JH
429{
430 struct alternate_object_database *ent;
fe1b2268 431 int r = 0;
d79796bc
JH
432
433 prepare_alt_odb();
fe1b2268
JK
434 for (ent = alt_odb_list; ent; ent = ent->next) {
435 r = fn(ent, cb);
436 if (r)
437 break;
438 }
439 return r;
d79796bc
JH
440}
441
c2f493a4
MW
442void prepare_alt_odb(void)
443{
554fe20d 444 const char *alt;
c2f493a4 445
7dc24aa5
SP
446 if (alt_odb_tail)
447 return;
448
c2f493a4
MW
449 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
450 if (!alt) alt = "";
451
c2f493a4 452 alt_odb_tail = &alt_odb_list;
c5950164 453 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
454
455 read_info_alternates(get_object_directory(), 0);
456}
457
3096b2ec 458/* Returns 1 if we have successfully freshened the file, 0 otherwise. */
33d4221c 459static int freshen_file(const char *fn)
ace1534d 460{
33d4221c
JK
461 struct utimbuf t;
462 t.actime = t.modtime = time(NULL);
463 return !utime(fn, &t);
0f4dc14a 464}
ace1534d 465
3096b2ec
JK
466/*
467 * All of the check_and_freshen functions return 1 if the file exists and was
468 * freshened (if freshening was requested), 0 otherwise. If they return
469 * 0, you should not assume that it is safe to skip a write of the object (it
470 * either does not exist on disk, or has a stale mtime and may be subject to
471 * pruning).
472 */
33d4221c
JK
473static int check_and_freshen_file(const char *fn, int freshen)
474{
475 if (access(fn, F_OK))
476 return 0;
3096b2ec 477 if (freshen && !freshen_file(fn))
33d4221c
JK
478 return 0;
479 return 1;
480}
481
482static int check_and_freshen_local(const unsigned char *sha1, int freshen)
483{
484 return check_and_freshen_file(sha1_file_name(sha1), freshen);
485}
486
487static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
0f4dc14a
BC
488{
489 struct alternate_object_database *alt;
9a217f2a 490 prepare_alt_odb();
d5a63b99 491 for (alt = alt_odb_list; alt; alt = alt->next) {
0f4dc14a 492 fill_sha1_path(alt->name, sha1);
33d4221c 493 if (check_and_freshen_file(alt->base, freshen))
c529d75a 494 return 1;
ace1534d 495 }
c529d75a 496 return 0;
ace1534d
JH
497}
498
33d4221c
JK
499static int check_and_freshen(const unsigned char *sha1, int freshen)
500{
501 return check_and_freshen_local(sha1, freshen) ||
502 check_and_freshen_nonlocal(sha1, freshen);
503}
504
505int has_loose_object_nonlocal(const unsigned char *sha1)
506{
507 return check_and_freshen_nonlocal(sha1, 0);
508}
509
0f4dc14a
BC
510static int has_loose_object(const unsigned char *sha1)
511{
33d4221c 512 return check_and_freshen(sha1, 0);
0f4dc14a
BC
513}
514
60bb8b14 515static unsigned int pack_used_ctr;
a53128b6
SP
516static unsigned int pack_mmap_calls;
517static unsigned int peak_pack_open_windows;
518static unsigned int pack_open_windows;
c7934306
SP
519static unsigned int pack_open_fds;
520static unsigned int pack_max_fds;
a53128b6 521static size_t peak_pack_mapped;
60bb8b14 522static size_t pack_mapped;
9a217f2a 523struct packed_git *packed_git;
1f688557 524
b79d18c9 525void pack_report(void)
a53128b6
SP
526{
527 fprintf(stderr,
e05db0fd
PR
528 "pack_report: getpagesize() = %10" SZ_FMT "\n"
529 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
530 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
531 sz_fmt(getpagesize()),
532 sz_fmt(packed_git_window_size),
533 sz_fmt(packed_git_limit));
a53128b6
SP
534 fprintf(stderr,
535 "pack_report: pack_used_ctr = %10u\n"
536 "pack_report: pack_mmap_calls = %10u\n"
537 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
538 "pack_report: pack_mapped = "
539 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
540 pack_used_ctr,
541 pack_mmap_calls,
542 pack_open_windows, peak_pack_open_windows,
9e42d6a1 543 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
544}
545
d40d535b
MH
546/*
547 * Open and mmap the index file at path, perform a couple of
548 * consistency checks, then record its information to p. Return 0 on
549 * success.
550 */
551static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
552{
553 void *idx_map;
42873078 554 struct pack_idx_header *hdr;
dc49cd76 555 size_t idx_size;
74e34e1f 556 uint32_t version, nr, i, *index;
f4e51683 557 int fd = git_open_noatime(path);
1f688557 558 struct stat st;
42873078 559
1f688557
JH
560 if (fd < 0)
561 return -1;
562 if (fstat(fd, &st)) {
563 close(fd);
564 return -1;
565 }
dc49cd76 566 idx_size = xsize_t(st.st_size);
2d88451b
SP
567 if (idx_size < 4 * 256 + 20 + 20) {
568 close(fd);
569 return error("index file %s is too small", path);
570 }
c4712e45 571 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 572 close(fd);
1f688557 573
42873078
NP
574 hdr = idx_map;
575 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
576 version = ntohl(hdr->idx_version);
577 if (version < 2 || version > 2) {
578 munmap(idx_map, idx_size);
6e1c2344 579 return error("index file %s is version %"PRIu32
74e34e1f
NP
580 " and is not supported by this binary"
581 " (try upgrading GIT to a newer version)",
582 path, version);
583 }
584 } else
585 version = 1;
df1b059d 586
1f688557 587 nr = 0;
42873078 588 index = idx_map;
74e34e1f
NP
589 if (version > 1)
590 index += 2; /* skip index header */
1f688557 591 for (i = 0; i < 256; i++) {
326bf396 592 uint32_t n = ntohl(index[i]);
2d88451b
SP
593 if (n < nr) {
594 munmap(idx_map, idx_size);
df1b059d 595 return error("non-monotonic index %s", path);
2d88451b 596 }
1f688557
JH
597 nr = n;
598 }
599
74e34e1f
NP
600 if (version == 1) {
601 /*
602 * Total size:
603 * - 256 index entries 4 bytes each
604 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
605 * - 20-byte SHA1 of the packfile
606 * - 20-byte SHA1 file checksum
607 */
608 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
609 munmap(idx_map, idx_size);
eef427a0 610 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
611 }
612 } else if (version == 2) {
613 /*
614 * Minimum size:
615 * - 8 bytes of header
616 * - 256 index entries 4 bytes each
617 * - 20-byte sha1 entry * nr
618 * - 4-byte crc entry * nr
619 * - 4-byte offset entry * nr
620 * - 20-byte SHA1 of the packfile
621 * - 20-byte SHA1 file checksum
622 * And after the 4-byte offset table might be a
623 * variable sized table containing 8-byte entries
624 * for offsets larger than 2^31.
625 */
626 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
627 unsigned long max_size = min_size;
628 if (nr)
629 max_size += (nr - 1)*8;
630 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 631 munmap(idx_map, idx_size);
eef427a0 632 return error("wrong index v2 file size in %s", path);
74e34e1f 633 }
7109c889
JH
634 if (idx_size != min_size &&
635 /*
636 * make sure we can deal with large pack offsets.
637 * 31-bit signed offset won't be enough, neither
638 * 32-bit unsigned one will be.
639 */
640 (sizeof(off_t) <= 4)) {
641 munmap(idx_map, idx_size);
642 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 643 }
2d88451b 644 }
1f688557 645
74e34e1f 646 p->index_version = version;
42873078
NP
647 p->index_data = idx_map;
648 p->index_size = idx_size;
57059091 649 p->num_objects = nr;
1f688557
JH
650 return 0;
651}
652
bc8e478a 653int open_pack_index(struct packed_git *p)
d079837e
SP
654{
655 char *idx_name;
9ae97018 656 size_t len;
d079837e
SP
657 int ret;
658
659 if (p->index_data)
660 return 0;
661
9ae97018
JK
662 if (!strip_suffix(p->pack_name, ".pack", &len))
663 die("BUG: pack_name does not end in .pack");
664 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
d079837e
SP
665 ret = check_packed_git_idx(idx_name, p);
666 free(idx_name);
667 return ret;
668}
669
11daf39b
SP
670static void scan_windows(struct packed_git *p,
671 struct packed_git **lru_p,
672 struct pack_window **lru_w,
673 struct pack_window **lru_l)
1f688557 674{
11daf39b
SP
675 struct pack_window *w, *w_l;
676
677 for (w_l = NULL, w = p->windows; w; w = w->next) {
678 if (!w->inuse_cnt) {
679 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
680 *lru_p = p;
681 *lru_w = w;
682 *lru_l = w_l;
54044bf8 683 }
54044bf8 684 }
11daf39b 685 w_l = w;
f9253394 686 }
11daf39b
SP
687}
688
7c3ecb32 689static int unuse_one_window(struct packed_git *current)
11daf39b
SP
690{
691 struct packed_git *p, *lru_p = NULL;
692 struct pack_window *lru_w = NULL, *lru_l = NULL;
693
694 if (current)
695 scan_windows(current, &lru_p, &lru_w, &lru_l);
696 for (p = packed_git; p; p = p->next)
697 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
698 if (lru_p) {
699 munmap(lru_w->base, lru_w->len);
700 pack_mapped -= lru_w->len;
701 if (lru_l)
702 lru_l->next = lru_w->next;
7c3ecb32 703 else
54044bf8 704 lru_p->windows = lru_w->next;
54044bf8 705 free(lru_w);
a53128b6 706 pack_open_windows--;
54044bf8
SP
707 return 1;
708 }
709 return 0;
f9253394
JH
710}
711
7c3ecb32 712void release_pack_memory(size_t need)
97bfeb34
SP
713{
714 size_t cur = pack_mapped;
7c3ecb32 715 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
97bfeb34
SP
716 ; /* nothing */
717}
718
02710228
SP
719static void mmap_limit_check(size_t length)
720{
721 static size_t limit = 0;
722 if (!limit) {
723 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
724 if (!limit)
725 limit = SIZE_MAX;
726 }
727 if (length > limit)
728 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
729 (uintmax_t)length, (uintmax_t)limit);
730}
731
1570856b
JK
732void *xmmap_gently(void *start, size_t length,
733 int prot, int flags, int fd, off_t offset)
58ecbd5e 734{
02710228
SP
735 void *ret;
736
737 mmap_limit_check(length);
738 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
739 if (ret == MAP_FAILED) {
740 if (!length)
741 return NULL;
7c3ecb32 742 release_pack_memory(length);
58ecbd5e 743 ret = mmap(start, length, prot, flags, fd, offset);
58ecbd5e
JN
744 }
745 return ret;
746}
747
1570856b
JK
748void *xmmap(void *start, size_t length,
749 int prot, int flags, int fd, off_t offset)
750{
751 void *ret = xmmap_gently(start, length, prot, flags, fd, offset);
752 if (ret == MAP_FAILED)
9ca0aaf6 753 die_errno("mmap failed");
1570856b
JK
754 return ret;
755}
756
c9ced051
SP
757void close_pack_windows(struct packed_git *p)
758{
759 while (p->windows) {
760 struct pack_window *w = p->windows;
761
762 if (w->inuse_cnt)
763 die("pack '%s' still has open windows to it",
764 p->pack_name);
765 munmap(w->base, w->len);
766 pack_mapped -= w->len;
767 pack_open_windows--;
768 p->windows = w->next;
769 free(w);
770 }
771}
772
71fe5d7f
JS
773static int close_pack_fd(struct packed_git *p)
774{
775 if (p->pack_fd < 0)
776 return 0;
777
778 close(p->pack_fd);
779 pack_open_fds--;
780 p->pack_fd = -1;
781
782 return 1;
783}
784
38849a81
JS
785static void close_pack(struct packed_git *p)
786{
787 close_pack_windows(p);
788 close_pack_fd(p);
789 close_pack_index(p);
790}
791
792void close_all_packs(void)
793{
794 struct packed_git *p;
795
796 for (p = packed_git; p; p = p->next)
797 if (p->do_not_close)
798 die("BUG! Want to close pack marked 'do-not-close'");
799 else
800 close_pack(p);
801}
802
803
88d0db55
BC
804/*
805 * The LRU pack is the one with the oldest MRU window, preferring packs
806 * with no used windows, or the oldest mtime if it has no windows allocated.
807 */
808static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
809{
810 struct pack_window *w, *this_mru_w;
811 int has_windows_inuse = 0;
812
813 /*
814 * Reject this pack if it has windows and the previously selected
815 * one does not. If this pack does not have windows, reject
816 * it if the pack file is newer than the previously selected one.
817 */
818 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
819 return;
820
821 for (w = this_mru_w = p->windows; w; w = w->next) {
822 /*
823 * Reject this pack if any of its windows are in use,
824 * but the previously selected pack did not have any
825 * inuse windows. Otherwise, record that this pack
826 * has windows in use.
827 */
828 if (w->inuse_cnt) {
829 if (*accept_windows_inuse)
830 has_windows_inuse = 1;
831 else
832 return;
833 }
834
835 if (w->last_used > this_mru_w->last_used)
836 this_mru_w = w;
837
838 /*
839 * Reject this pack if it has windows that have been
840 * used more recently than the previously selected pack.
841 * If the previously selected pack had windows inuse and
842 * we have not encountered a window in this pack that is
843 * inuse, skip this check since we prefer a pack with no
844 * inuse windows to one that has inuse windows.
845 */
846 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
847 this_mru_w->last_used > (*mru_w)->last_used)
848 return;
849 }
850
851 /*
852 * Select this pack.
853 */
854 *mru_w = this_mru_w;
855 *lru_p = p;
856 *accept_windows_inuse = has_windows_inuse;
857}
858
859static int close_one_pack(void)
860{
861 struct packed_git *p, *lru_p = NULL;
862 struct pack_window *mru_w = NULL;
863 int accept_windows_inuse = 1;
864
865 for (p = packed_git; p; p = p->next) {
866 if (p->pack_fd == -1)
867 continue;
868 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
869 }
870
71fe5d7f
JS
871 if (lru_p)
872 return close_pack_fd(lru_p);
88d0db55
BC
873
874 return 0;
875}
876
03e79c88 877void unuse_pack(struct pack_window **w_cursor)
f9253394 878{
03e79c88
SP
879 struct pack_window *w = *w_cursor;
880 if (w) {
881 w->inuse_cnt--;
882 *w_cursor = NULL;
883 }
1f688557
JH
884}
885
fa5fc15d
SP
886void close_pack_index(struct packed_git *p)
887{
888 if (p->index_data) {
889 munmap((void *)p->index_data, p->index_size);
890 p->index_data = NULL;
891 }
892}
893
a0788266
JS
894static unsigned int get_max_fd_limit(void)
895{
896#ifdef RLIMIT_NOFILE
491a8dec
JH
897 {
898 struct rlimit lim;
a0788266 899
491a8dec
JH
900 if (!getrlimit(RLIMIT_NOFILE, &lim))
901 return lim.rlim_cur;
902 }
903#endif
904
905#ifdef _SC_OPEN_MAX
906 {
907 long open_max = sysconf(_SC_OPEN_MAX);
908 if (0 < open_max)
909 return open_max;
910 /*
911 * Otherwise, we got -1 for one of the two
912 * reasons:
913 *
914 * (1) sysconf() did not understand _SC_OPEN_MAX
915 * and signaled an error with -1; or
916 * (2) sysconf() said there is no limit.
917 *
918 * We _could_ clear errno before calling sysconf() to
919 * tell these two cases apart and return a huge number
920 * in the latter case to let the caller cap it to a
921 * value that is not so selfish, but letting the
922 * fallback OPEN_MAX codepath take care of these cases
923 * is a lot simpler.
924 */
925 }
926#endif
a0788266 927
491a8dec 928#ifdef OPEN_MAX
a0788266
JS
929 return OPEN_MAX;
930#else
931 return 1; /* see the caller ;-) */
932#endif
933}
934
3cf8b462
SP
935/*
936 * Do not call this directly as this leaks p->pack_fd on error return;
937 * call open_packed_git() instead.
938 */
939static int open_packed_git_1(struct packed_git *p)
1f688557 940{
9bc879c1
SP
941 struct stat st;
942 struct pack_header hdr;
943 unsigned char sha1[20];
944 unsigned char *idx_sha1;
2c039da8 945 long fd_flag;
9bc879c1 946
d079837e
SP
947 if (!p->index_data && open_pack_index(p))
948 return error("packfile %s index unavailable", p->pack_name);
949
c7934306 950 if (!pack_max_fds) {
a0788266 951 unsigned int max_fds = get_max_fd_limit();
c7934306
SP
952
953 /* Save 3 for stdin/stdout/stderr, 22 for work */
954 if (25 < max_fds)
955 pack_max_fds = max_fds - 25;
956 else
957 pack_max_fds = 1;
958 }
959
88d0db55 960 while (pack_max_fds <= pack_open_fds && close_one_pack())
c7934306
SP
961 ; /* nothing */
962
f4e51683 963 p->pack_fd = git_open_noatime(p->pack_name);
9bc879c1 964 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 965 return -1;
c7934306 966 pack_open_fds++;
9bc879c1
SP
967
968 /* If we created the struct before we had the pack we lack size. */
bf592c50 969 if (!p->pack_size) {
bf592c50 970 if (!S_ISREG(st.st_mode))
072db278 971 return error("packfile %s not a regular file", p->pack_name);
bf592c50 972 p->pack_size = st.st_size;
9bc879c1 973 } else if (p->pack_size != st.st_size)
072db278 974 return error("packfile %s size changed", p->pack_name);
9bc879c1 975
2c039da8
JH
976 /* We leave these file descriptors open with sliding mmap;
977 * there is no point keeping them open across exec(), though.
978 */
979 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
980 if (fd_flag < 0)
072db278 981 return error("cannot determine file descriptor flags");
2c039da8
JH
982 fd_flag |= FD_CLOEXEC;
983 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 984 return error("cannot set FD_CLOEXEC");
2c039da8 985
9bc879c1 986 /* Verify we recognize this pack file format. */
e6e2bd62 987 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 988 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 989 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 990 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 991 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
992 return error("packfile %s is version %"PRIu32" and not"
993 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
994 p->pack_name, ntohl(hdr.hdr_version));
995
996 /* Verify the pack matches its index. */
57059091 997 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
998 return error("packfile %s claims to have %"PRIu32" objects"
999 " while index indicates %"PRIu32" objects",
57059091
NP
1000 p->pack_name, ntohl(hdr.hdr_entries),
1001 p->num_objects);
9bc879c1 1002 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 1003 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 1004 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 1005 return error("packfile %s signature is unavailable", p->pack_name);
42873078 1006 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 1007 if (hashcmp(sha1, idx_sha1))
072db278
SP
1008 return error("packfile %s does not match index", p->pack_name);
1009 return 0;
9bc879c1
SP
1010}
1011
3cf8b462
SP
1012static int open_packed_git(struct packed_git *p)
1013{
1014 if (!open_packed_git_1(p))
1015 return 0;
71fe5d7f 1016 close_pack_fd(p);
3cf8b462
SP
1017 return -1;
1018}
1019
c4001d92 1020static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
1021{
1022 /* We must promise at least 20 bytes (one hash) after the
1023 * offset is available from this window, otherwise the offset
1024 * is not actually in this window and a different window (which
1025 * has that one hash excess) must be used. This is to support
1026 * the object header and delta base parsing routines below.
1027 */
1028 off_t win_off = win->offset;
1029 return win_off <= offset
1030 && (offset + 20) <= (win_off + win->len);
1031}
1032
4b25d091 1033unsigned char *use_pack(struct packed_git *p,
03e79c88 1034 struct pack_window **w_cursor,
c4001d92 1035 off_t offset,
ef49a7a0 1036 unsigned long *left)
9bc879c1 1037{
60bb8b14 1038 struct pack_window *win = *w_cursor;
03e79c88 1039
a9d98a14 1040 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
1041 * pointless to ask for an offset into the middle of that
1042 * hash, and the in_window function above wouldn't match
1043 * don't allow an offset too close to the end of the file.
1044 */
d131b7af
SP
1045 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1046 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
1047 if (offset > (p->pack_size - 20))
1048 die("offset beyond end of packfile (truncated pack?)");
13e0b0d3 1049 if (offset < 0)
7465feba 1050 die(_("offset before end of packfile (broken .idx?)"));
60bb8b14
SP
1051
1052 if (!win || !in_window(win, offset)) {
1053 if (win)
1054 win->inuse_cnt--;
1055 for (win = p->windows; win; win = win->next) {
1056 if (in_window(win, offset))
1057 break;
1058 }
1059 if (!win) {
78a28df9 1060 size_t window_align = packed_git_window_size / 2;
dc49cd76 1061 off_t len;
d131b7af
SP
1062
1063 if (p->pack_fd == -1 && open_packed_git(p))
1064 die("packfile %s cannot be accessed", p->pack_name);
1065
60bb8b14 1066 win = xcalloc(1, sizeof(*win));
78a28df9 1067 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
1068 len = p->pack_size - win->offset;
1069 if (len > packed_git_window_size)
1070 len = packed_git_window_size;
1071 win->len = (size_t)len;
60bb8b14 1072 pack_mapped += win->len;
11daf39b 1073 while (packed_git_limit < pack_mapped
7c3ecb32 1074 && unuse_one_window(p))
60bb8b14 1075 ; /* nothing */
c4712e45 1076 win->base = xmmap(NULL, win->len,
60bb8b14
SP
1077 PROT_READ, MAP_PRIVATE,
1078 p->pack_fd, win->offset);
1079 if (win->base == MAP_FAILED)
7616c6ca
NTND
1080 die_errno("packfile %s cannot be mapped",
1081 p->pack_name);
d131b7af 1082 if (!win->offset && win->len == p->pack_size
71fe5d7f
JS
1083 && !p->do_not_close)
1084 close_pack_fd(p);
a53128b6
SP
1085 pack_mmap_calls++;
1086 pack_open_windows++;
1087 if (pack_mapped > peak_pack_mapped)
1088 peak_pack_mapped = pack_mapped;
1089 if (pack_open_windows > peak_pack_open_windows)
1090 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
1091 win->next = p->windows;
1092 p->windows = win;
1093 }
1f688557 1094 }
03e79c88
SP
1095 if (win != *w_cursor) {
1096 win->last_used = pack_used_ctr++;
1097 win->inuse_cnt++;
1098 *w_cursor = win;
1099 }
60bb8b14 1100 offset -= win->offset;
03e79c88 1101 if (left)
dc49cd76 1102 *left = win->len - xsize_t(offset);
03e79c88 1103 return win->base + offset;
1f688557
JH
1104}
1105
27d69a46
NP
1106static struct packed_git *alloc_packed_git(int extra)
1107{
50a6c8ef 1108 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
27d69a46
NP
1109 memset(p, 0, sizeof(*p));
1110 p->pack_fd = -1;
1111 return p;
1112}
1113
e0500293
JN
1114static void try_to_free_pack_memory(size_t size)
1115{
7c3ecb32 1116 release_pack_memory(size);
e0500293
JN
1117}
1118
48bcc1c3 1119struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1f688557 1120{
e0500293 1121 static int have_set_try_to_free_routine;
1f688557 1122 struct stat st;
48bcc1c3
JK
1123 size_t alloc;
1124 struct packed_git *p;
1f688557 1125
e0500293
JN
1126 if (!have_set_try_to_free_routine) {
1127 have_set_try_to_free_routine = 1;
1128 set_try_to_free_routine(try_to_free_pack_memory);
1129 }
1130
42873078
NP
1131 /*
1132 * Make sure a corresponding .pack file exists and that
1133 * the index looks sane.
1134 */
48bcc1c3 1135 if (!strip_suffix_mem(path, &path_len, ".idx"))
1f688557 1136 return NULL;
48bcc1c3
JK
1137
1138 /*
1139 * ".pack" is long enough to hold any suffix we're adding (and
1140 * the use xsnprintf double-checks that)
1141 */
50a6c8ef 1142 alloc = st_add3(path_len, strlen(".pack"), 1);
48bcc1c3 1143 p = alloc_packed_git(alloc);
42873078 1144 memcpy(p->pack_name, path, path_len);
8d25931d 1145
48bcc1c3 1146 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
8d25931d
BC
1147 if (!access(p->pack_name, F_OK))
1148 p->pack_keep = 1;
1149
48bcc1c3 1150 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
d079837e 1151 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 1152 free(p);
1f688557
JH
1153 return NULL;
1154 }
42873078 1155
1f688557
JH
1156 /* ok, it looks sane as far as we can check without
1157 * actually mapping the pack file.
1158 */
1f688557 1159 p->pack_size = st.st_size;
9d835df2 1160 p->pack_local = local;
b867092f 1161 p->mtime = st.st_mtime;
42873078
NP
1162 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1163 hashclr(p->sha1);
1f688557
JH
1164 return p;
1165}
1166
7b64469a 1167struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 1168{
42873078 1169 const char *path = sha1_pack_name(sha1);
50a6c8ef 1170 size_t alloc = st_add(strlen(path), 1);
c7ab0ba3 1171 struct packed_git *p = alloc_packed_git(alloc);
bf592c50 1172
c7ab0ba3 1173 memcpy(p->pack_name, path, alloc); /* includes NUL */
27d69a46 1174 hashcpy(p->sha1, sha1);
42873078
NP
1175 if (check_packed_git_idx(idx_path, p)) {
1176 free(p);
bf592c50 1177 return NULL;
42873078 1178 }
bf592c50 1179
bf592c50
DB
1180 return p;
1181}
1182
1183void install_packed_git(struct packed_git *pack)
1184{
c7934306
SP
1185 if (pack->pack_fd != -1)
1186 pack_open_fds++;
1187
bf592c50
DB
1188 pack->next = packed_git;
1189 packed_git = pack;
1190}
1191
0a489b06 1192void (*report_garbage)(unsigned seen_bits, const char *path);
543c5caa
NTND
1193
1194static void report_helper(const struct string_list *list,
1195 int seen_bits, int first, int last)
1196{
0a489b06 1197 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
543c5caa 1198 return;
0a489b06 1199
543c5caa 1200 for (; first < last; first++)
0a489b06 1201 report_garbage(seen_bits, list->items[first].string);
543c5caa
NTND
1202}
1203
1204static void report_pack_garbage(struct string_list *list)
1205{
1206 int i, baselen = -1, first = 0, seen_bits = 0;
1207
1208 if (!report_garbage)
1209 return;
1210
3383e199 1211 string_list_sort(list);
543c5caa
NTND
1212
1213 for (i = 0; i < list->nr; i++) {
1214 const char *path = list->items[i].string;
1215 if (baselen != -1 &&
1216 strncmp(path, list->items[first].string, baselen)) {
1217 report_helper(list, seen_bits, first, i);
1218 baselen = -1;
1219 seen_bits = 0;
1220 }
1221 if (baselen == -1) {
1222 const char *dot = strrchr(path, '.');
1223 if (!dot) {
0a489b06 1224 report_garbage(PACKDIR_FILE_GARBAGE, path);
543c5caa
NTND
1225 continue;
1226 }
1227 baselen = dot - path + 1;
1228 first = i;
1229 }
1230 if (!strcmp(path + baselen, "pack"))
1231 seen_bits |= 1;
1232 else if (!strcmp(path + baselen, "idx"))
1233 seen_bits |= 2;
1234 }
1235 report_helper(list, seen_bits, first, list->nr);
1236}
1237
9d835df2 1238static void prepare_packed_git_one(char *objdir, int local)
1f688557 1239{
880fb8de
RS
1240 struct strbuf path = STRBUF_INIT;
1241 size_t dirnamelen;
1f688557
JH
1242 DIR *dir;
1243 struct dirent *de;
543c5caa 1244 struct string_list garbage = STRING_LIST_INIT_DUP;
1f688557 1245
880fb8de
RS
1246 strbuf_addstr(&path, objdir);
1247 strbuf_addstr(&path, "/pack");
1248 dir = opendir(path.buf);
b5b16990 1249 if (!dir) {
26125f6b 1250 if (errno != ENOENT)
7616c6ca
NTND
1251 error_errno("unable to open object pack directory: %s",
1252 path.buf);
880fb8de 1253 strbuf_release(&path);
1f688557 1254 return;
b5b16990 1255 }
880fb8de
RS
1256 strbuf_addch(&path, '/');
1257 dirnamelen = path.len;
1f688557 1258 while ((de = readdir(dir)) != NULL) {
1f688557 1259 struct packed_git *p;
47bf4b0f 1260 size_t base_len;
543c5caa
NTND
1261
1262 if (is_dot_or_dotdot(de->d_name))
9cb18f56
JM
1263 continue;
1264
880fb8de
RS
1265 strbuf_setlen(&path, dirnamelen);
1266 strbuf_addstr(&path, de->d_name);
d90906a9 1267
47bf4b0f
JK
1268 base_len = path.len;
1269 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
d90906a9
NTND
1270 /* Don't reopen a pack we already have. */
1271 for (p = packed_git; p; p = p->next) {
47bf4b0f
JK
1272 size_t len;
1273 if (strip_suffix(p->pack_name, ".pack", &len) &&
1274 len == base_len &&
1275 !memcmp(p->pack_name, path.buf, len))
d90906a9
NTND
1276 break;
1277 }
1278 if (p == NULL &&
1279 /*
1280 * See if it really is a valid .idx file with
1281 * corresponding .pack file that we can map.
1282 */
880fb8de 1283 (p = add_packed_git(path.buf, path.len, local)) != NULL)
d90906a9 1284 install_packed_git(p);
86f7780c 1285 }
543c5caa
NTND
1286
1287 if (!report_garbage)
1288 continue;
1289
2975c770
JK
1290 if (ends_with(de->d_name, ".idx") ||
1291 ends_with(de->d_name, ".pack") ||
1292 ends_with(de->d_name, ".bitmap") ||
1293 ends_with(de->d_name, ".keep"))
880fb8de 1294 string_list_append(&garbage, path.buf);
543c5caa 1295 else
0a489b06 1296 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1f688557 1297 }
5b35bcd5 1298 closedir(dir);
543c5caa
NTND
1299 report_pack_garbage(&garbage);
1300 string_list_clear(&garbage, 0);
880fb8de 1301 strbuf_release(&path);
1f688557
JH
1302}
1303
b867092f
JH
1304static int sort_pack(const void *a_, const void *b_)
1305{
1306 struct packed_git *a = *((struct packed_git **)a_);
1307 struct packed_git *b = *((struct packed_git **)b_);
1308 int st;
1309
1310 /*
1311 * Local packs tend to contain objects specific to our
1312 * variant of the project than remote ones. In addition,
1313 * remote ones could be on a network mounted filesystem.
1314 * Favor local ones for these reasons.
1315 */
1316 st = a->pack_local - b->pack_local;
1317 if (st)
1318 return -st;
1319
1320 /*
1321 * Younger packs tend to contain more recent objects,
1322 * and more recent objects tend to get accessed more
1323 * often.
1324 */
1325 if (a->mtime < b->mtime)
1326 return 1;
1327 else if (a->mtime == b->mtime)
1328 return 0;
1329 return -1;
1330}
1331
1332static void rearrange_packed_git(void)
1333{
1334 struct packed_git **ary, *p;
1335 int i, n;
1336
1337 for (n = 0, p = packed_git; p; p = p->next)
1338 n++;
1339 if (n < 2)
1340 return;
1341
1342 /* prepare an array of packed_git for easier sorting */
1343 ary = xcalloc(n, sizeof(struct packed_git *));
1344 for (n = 0, p = packed_git; p; p = p->next)
1345 ary[n++] = p;
1346
1347 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1348
1349 /* link them back again */
1350 for (i = 0; i < n - 1; i++)
1351 ary[i]->next = ary[i + 1];
1352 ary[n - 1]->next = NULL;
1353 packed_git = ary[0];
1354
1355 free(ary);
1356}
1357
637cdd9d 1358static int prepare_packed_git_run_once = 0;
9a217f2a 1359void prepare_packed_git(void)
1f688557 1360{
d5a63b99 1361 struct alternate_object_database *alt;
1f688557 1362
637cdd9d 1363 if (prepare_packed_git_run_once)
1f688557 1364 return;
9d835df2 1365 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1366 prepare_alt_odb();
d5a63b99 1367 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 1368 alt->name[-1] = 0;
9d835df2 1369 prepare_packed_git_one(alt->base, 0);
1494e038 1370 alt->name[-1] = '/';
1f688557 1371 }
b867092f 1372 rearrange_packed_git();
637cdd9d
JK
1373 prepare_packed_git_run_once = 1;
1374}
1375
fc04c412 1376void reprepare_packed_git(void)
637cdd9d
JK
1377{
1378 prepare_packed_git_run_once = 0;
1379 prepare_packed_git();
1f688557
JH
1380}
1381
8eca0b47
NP
1382static void mark_bad_packed_object(struct packed_git *p,
1383 const unsigned char *sha1)
1384{
1385 unsigned i;
1386 for (i = 0; i < p->num_bad_objects; i++)
50a6c8ef 1387 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
8eca0b47 1388 return;
50a6c8ef
JK
1389 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1390 st_mult(GIT_SHA1_RAWSZ,
1391 st_add(p->num_bad_objects, 1)));
1392 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
8eca0b47
NP
1393 p->num_bad_objects++;
1394}
1395
b6c4cecc 1396static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1397{
1398 struct packed_git *p;
1399 unsigned i;
1400
1401 for (p = packed_git; p; p = p->next)
1402 for (i = 0; i < p->num_bad_objects; i++)
1403 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1404 return p;
1405 return NULL;
ac939109
NP
1406}
1407
090ea126
NTND
1408/*
1409 * With an in-core object data in "map", rehash it to make sure the
1410 * object name actually matches "sha1" to detect object corruption.
1411 * With "map" == NULL, try reading the object named with "sha1" using
1412 * the streaming interface and rehash it to do the same.
1413 */
1414int check_sha1_signature(const unsigned char *sha1, void *map,
1415 unsigned long size, const char *type)
0fcfd160
LT
1416{
1417 unsigned char real_sha1[20];
090ea126
NTND
1418 enum object_type obj_type;
1419 struct git_istream *st;
1420 git_SHA_CTX c;
1421 char hdr[32];
1422 int hdrlen;
1423
1424 if (map) {
1425 hash_sha1_file(map, size, type, real_sha1);
1426 return hashcmp(sha1, real_sha1) ? -1 : 0;
1427 }
1428
1429 st = open_istream(sha1, &obj_type, &size, NULL);
1430 if (!st)
1431 return -1;
1432
1433 /* Generate the header */
ef1286d3 1434 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
090ea126
NTND
1435
1436 /* Sha1.. */
1437 git_SHA1_Init(&c);
1438 git_SHA1_Update(&c, hdr, hdrlen);
1439 for (;;) {
1440 char buf[1024 * 16];
1441 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1442
f54fac53
JK
1443 if (readlen < 0) {
1444 close_istream(st);
1445 return -1;
1446 }
090ea126
NTND
1447 if (!readlen)
1448 break;
1449 git_SHA1_Update(&c, buf, readlen);
1450 }
1451 git_SHA1_Final(real_sha1, &c);
1452 close_istream(st);
a89fccd2 1453 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1454}
1455
ec73f580 1456int git_open_noatime(const char *name)
44d1c19e
LT
1457{
1458 static int sha1_file_open_flag = O_NOATIME;
44d1c19e 1459
f2e872aa 1460 for (;;) {
dff6f280
CB
1461 int fd;
1462
1463 errno = 0;
1464 fd = open(name, O_RDONLY | sha1_file_open_flag);
44d1c19e 1465 if (fd >= 0)
f2e872aa
SP
1466 return fd;
1467
f2e872aa
SP
1468 /* Might the failure be due to O_NOATIME? */
1469 if (errno != ENOENT && sha1_file_open_flag) {
44d1c19e 1470 sha1_file_open_flag = 0;
f2e872aa
SP
1471 continue;
1472 }
1473
1474 return -1;
44d1c19e 1475 }
44d1c19e
LT
1476}
1477
052fe5ea
JK
1478static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1479{
052fe5ea
JK
1480 struct alternate_object_database *alt;
1481
30d6c6ea 1482 if (!lstat(sha1_file_name(sha1), st))
052fe5ea
JK
1483 return 0;
1484
1485 prepare_alt_odb();
1486 errno = ENOENT;
1487 for (alt = alt_odb_list; alt; alt = alt->next) {
30d6c6ea 1488 fill_sha1_path(alt->name, sha1);
052fe5ea
JK
1489 if (!lstat(alt->base, st))
1490 return 0;
1491 }
1492
1493 return -1;
1494}
1495
44d1c19e
LT
1496static int open_sha1_file(const unsigned char *sha1)
1497{
1498 int fd;
44d1c19e 1499 struct alternate_object_database *alt;
d6c8a05b 1500 int most_interesting_errno;
44d1c19e 1501
30d6c6ea 1502 fd = git_open_noatime(sha1_file_name(sha1));
44d1c19e
LT
1503 if (fd >= 0)
1504 return fd;
d6c8a05b 1505 most_interesting_errno = errno;
44d1c19e
LT
1506
1507 prepare_alt_odb();
44d1c19e 1508 for (alt = alt_odb_list; alt; alt = alt->next) {
30d6c6ea 1509 fill_sha1_path(alt->name, sha1);
f4e51683 1510 fd = git_open_noatime(alt->base);
44d1c19e
LT
1511 if (fd >= 0)
1512 return fd;
d6c8a05b
JK
1513 if (most_interesting_errno == ENOENT)
1514 most_interesting_errno = errno;
44d1c19e 1515 }
d6c8a05b 1516 errno = most_interesting_errno;
44d1c19e
LT
1517 return -1;
1518}
1519
f0270efd 1520void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1521{
0fcfd160 1522 void *map;
144bde78 1523 int fd;
ace1534d 1524
44d1c19e
LT
1525 fd = open_sha1_file(sha1);
1526 map = NULL;
1527 if (fd >= 0) {
1528 struct stat st;
0fcfd160 1529
44d1c19e
LT
1530 if (!fstat(fd, &st)) {
1531 *size = xsize_t(st.st_size);
33e42de0
MM
1532 if (!*size) {
1533 /* mmap() is forbidden on empty files */
1534 error("object file %s is empty", sha1_file_name(sha1));
1535 return NULL;
1536 }
44d1c19e 1537 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1538 }
44d1c19e 1539 close(fd);
0fcfd160 1540 }
0fcfd160
LT
1541 return map;
1542}
1543
09ded04b
NP
1544unsigned long unpack_object_header_buffer(const unsigned char *buf,
1545 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1546{
ad1ed5ee 1547 unsigned shift;
48fb7deb 1548 unsigned long size, c;
ad1ed5ee
JH
1549 unsigned long used = 0;
1550
1551 c = buf[used++];
1552 *type = (c >> 4) & 7;
1553 size = c & 15;
1554 shift = 4;
1555 while (c & 0x80) {
f630cfda 1556 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1557 error("bad object header");
ea4f9685
JH
1558 size = used = 0;
1559 break;
09ded04b 1560 }
ad1ed5ee
JH
1561 c = buf[used++];
1562 size += (c & 0x7f) << shift;
1563 shift += 7;
1564 }
1565 *sizep = size;
1566 return used;
1567}
1568
eb4f4076 1569int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
ad1ed5ee 1570{
c4483576
LT
1571 /* Get the data stream */
1572 memset(stream, 0, sizeof(*stream));
1573 stream->next_in = map;
1574 stream->avail_in = mapsize;
1575 stream->next_out = buffer;
93821bd9
LT
1576 stream->avail_out = bufsiz;
1577
39c68542 1578 git_inflate_init(stream);
cc5c54e7 1579 return git_inflate(stream, 0);
c4483576
LT
1580}
1581
46f03448
KN
1582static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1583 unsigned long mapsize, void *buffer,
1584 unsigned long bufsiz, struct strbuf *header)
1585{
1586 int status;
1587
1588 status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
1589
1590 /*
1591 * Check if entire header is unpacked in the first iteration.
1592 */
1593 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1594 return 0;
1595
1596 /*
1597 * buffer[0..bufsiz] was not large enough. Copy the partial
1598 * result out to header, and then append the result of further
1599 * reading the stream.
1600 */
1601 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1602 stream->next_out = buffer;
1603 stream->avail_out = bufsiz;
1604
1605 do {
1606 status = git_inflate(stream, 0);
1607 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1608 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1609 return 0;
1610 stream->next_out = buffer;
1611 stream->avail_out = bufsiz;
1612 } while (status != Z_STREAM_END);
1613 return -1;
1614}
1615
ef49a7a0 1616static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1617{
1618 int bytes = strlen(buffer) + 1;
3aee68aa 1619 unsigned char *buf = xmallocz(size);
93821bd9 1620 unsigned long n;
7efbff75 1621 int status = Z_OK;
5180cacc 1622
93821bd9
LT
1623 n = stream->total_out - bytes;
1624 if (n > size)
1625 n = size;
1626 memcpy(buf, (char *) buffer + bytes, n);
1627 bytes = n;
456cdf6e
LT
1628 if (bytes <= size) {
1629 /*
1630 * The above condition must be (bytes <= size), not
1631 * (bytes < size). In other words, even though we
ccf5ace0 1632 * expect no more output and set avail_out to zero,
456cdf6e
LT
1633 * the input zlib stream may have bytes that express
1634 * "this concludes the stream", and we *do* want to
1635 * eat that input.
1636 *
1637 * Otherwise we would not be able to test that we
1638 * consumed all the input to reach the expected size;
1639 * we also want to check that zlib tells us that all
1640 * went well with status == Z_STREAM_END at the end.
1641 */
5180cacc
LT
1642 stream->next_out = buf + bytes;
1643 stream->avail_out = size - bytes;
7efbff75 1644 while (status == Z_OK)
39c68542 1645 status = git_inflate(stream, Z_FINISH);
5180cacc 1646 }
456cdf6e 1647 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1648 git_inflate_end(stream);
7efbff75
JH
1649 return buf;
1650 }
1651
1652 if (status < 0)
1653 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1654 else if (stream->avail_in)
1655 error("garbage at end of loose object '%s'",
1656 sha1_to_hex(sha1));
1657 free(buf);
1658 return NULL;
5180cacc
LT
1659}
1660
1661/*
1662 * We used to just use "sscanf()", but that's actually way
1663 * too permissive for what we want to check. So do an anal
1664 * object header parse by hand.
1665 */
46f03448
KN
1666static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1667 unsigned int flags)
5180cacc 1668{
46f03448 1669 const char *type_buf = hdr;
5180cacc 1670 unsigned long size;
46f03448 1671 int type, type_len = 0;
5180cacc
LT
1672
1673 /*
46f03448 1674 * The type can be of any size but is followed by
21666f1a 1675 * a space.
5180cacc 1676 */
5180cacc
LT
1677 for (;;) {
1678 char c = *hdr++;
1679 if (c == ' ')
1680 break;
46f03448 1681 type_len++;
5180cacc 1682 }
46f03448
KN
1683
1684 type = type_from_string_gently(type_buf, type_len, 1);
1685 if (oi->typename)
1686 strbuf_add(oi->typename, type_buf, type_len);
1687 /*
1688 * Set type to 0 if its an unknown object and
1689 * we're obtaining the type using '--allow-unkown-type'
1690 * option.
1691 */
1692 if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
1693 type = 0;
1694 else if (type < 0)
1695 die("invalid object type");
1696 if (oi->typep)
1697 *oi->typep = type;
5180cacc
LT
1698
1699 /*
1700 * The length must follow immediately, and be in canonical
1701 * decimal format (ie "010" is not valid).
1702 */
1703 size = *hdr++ - '0';
1704 if (size > 9)
1705 return -1;
1706 if (size) {
1707 for (;;) {
1708 unsigned long c = *hdr - '0';
1709 if (c > 9)
1710 break;
1711 hdr++;
1712 size = size * 10 + c;
1713 }
1714 }
46f03448
KN
1715
1716 if (oi->sizep)
1717 *oi->sizep = size;
5180cacc
LT
1718
1719 /*
1720 * The length must be followed by a zero byte
1721 */
46f03448
KN
1722 return *hdr ? -1 : type;
1723}
1724
1725int parse_sha1_header(const char *hdr, unsigned long *sizep)
1726{
1727 struct object_info oi;
1728
1729 oi.sizep = sizep;
1730 oi.typename = NULL;
1731 oi.typep = NULL;
1732 return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
5180cacc
LT
1733}
1734
7efbff75 1735static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1736{
5180cacc 1737 int ret;
ef49a7a0 1738 git_zstream stream;
5180cacc 1739 char hdr[8192];
0fcfd160 1740
5180cacc 1741 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1742 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1743 return NULL;
1744
7efbff75 1745 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1746}
1747
54dab52a
NP
1748unsigned long get_size_from_delta(struct packed_git *p,
1749 struct pack_window **w_curs,
1750 off_t curpos)
1751{
1752 const unsigned char *data;
1753 unsigned char delta_head[20], *in;
ef49a7a0 1754 git_zstream stream;
54dab52a
NP
1755 int st;
1756
1757 memset(&stream, 0, sizeof(stream));
1758 stream.next_out = delta_head;
1759 stream.avail_out = sizeof(delta_head);
1760
39c68542 1761 git_inflate_init(&stream);
54dab52a
NP
1762 do {
1763 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1764 stream.next_in = in;
39c68542 1765 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1766 curpos += stream.next_in - in;
1767 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1768 stream.total_out < sizeof(delta_head));
39c68542 1769 git_inflate_end(&stream);
3d77d877
NP
1770 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1771 error("delta data unpack-initial failed");
1772 return 0;
1773 }
54dab52a
NP
1774
1775 /* Examine the initial part of the delta to figure out
1776 * the result size.
1777 */
1778 data = delta_head;
1779
1780 /* ignore base size */
1781 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1782
1783 /* Read the result size */
1784 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1785}
1786
c4001d92 1787static off_t get_delta_base(struct packed_git *p,
03e79c88 1788 struct pack_window **w_curs,
c4001d92 1789 off_t *curpos,
21666f1a 1790 enum object_type type,
c4001d92 1791 off_t delta_obj_offset)
eb32d236 1792{
2b87c45b 1793 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1794 off_t base_offset;
eb32d236 1795
8d8a4ea5
SP
1796 /* use_pack() assured us we have [base_info, base_info + 20)
1797 * as a range that we can look at without walking off the
1798 * end of the mapped window. Its actually the hash size
1799 * that is assured. An OFS_DELTA longer than the hash size
1800 * is stupid, as then a REF_DELTA would be smaller to store.
1801 */
21666f1a 1802 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1803 unsigned used = 0;
1804 unsigned char c = base_info[used++];
1805 base_offset = c & 127;
1806 while (c & 128) {
1807 base_offset += 1;
8723f216 1808 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1809 return 0; /* overflow */
eb32d236
NP
1810 c = base_info[used++];
1811 base_offset = (base_offset << 7) + (c & 127);
1812 }
1813 base_offset = delta_obj_offset - base_offset;
d8f32556 1814 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 1815 return 0; /* out of bound */
2b87c45b 1816 *curpos += used;
21666f1a 1817 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1818 /* The base entry _must_ be in the same pack */
1819 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1820 *curpos += 20;
eb32d236
NP
1821 } else
1822 die("I am totally screwed");
2b87c45b 1823 return base_offset;
eb32d236
NP
1824}
1825
5d642e75
JK
1826/*
1827 * Like get_delta_base above, but we return the sha1 instead of the pack
1828 * offset. This means it is cheaper for REF deltas (we do not have to do
1829 * the final object lookup), but more expensive for OFS deltas (we
1830 * have to load the revidx to convert the offset back into a sha1).
1831 */
1832static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1833 struct pack_window **w_curs,
1834 off_t curpos,
1835 enum object_type type,
1836 off_t delta_obj_offset)
1837{
1838 if (type == OBJ_REF_DELTA) {
1839 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1840 return base;
1841 } else if (type == OBJ_OFS_DELTA) {
1842 struct revindex_entry *revidx;
1843 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1844 type, delta_obj_offset);
1845
1846 if (!base_offset)
1847 return NULL;
1848
1849 revidx = find_pack_revindex(p, base_offset);
1850 if (!revidx)
1851 return NULL;
1852
1853 return nth_packed_object_sha1(p, revidx->nr);
1854 } else
1855 return NULL;
1856}
1857
f8c8abc5
JH
1858int unpack_object_header(struct packed_git *p,
1859 struct pack_window **w_curs,
1860 off_t *curpos,
1861 unsigned long *sizep)
a733cb60 1862{
03e79c88 1863 unsigned char *base;
ef49a7a0 1864 unsigned long left;
ad1ed5ee 1865 unsigned long used;
2b87c45b 1866 enum object_type type;
a733cb60 1867
8d8a4ea5 1868 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 1869 * as a range that we can look at. (Its actually the hash
3dff5379 1870 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1871 * the maximum deflated object size is 2^137, which is just
1872 * insane, so we know won't exceed what we have been given.
1873 */
2b87c45b 1874 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
1875 used = unpack_object_header_buffer(base, left, &type, sizep);
1876 if (!used) {
1877 type = OBJ_BAD;
1878 } else
1879 *curpos += used;
ad1ed5ee 1880
2b87c45b 1881 return type;
a733cb60
LT
1882}
1883
790d96c0
TR
1884static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1885{
1886 int type;
1887 struct revindex_entry *revidx;
1888 const unsigned char *sha1;
1889 revidx = find_pack_revindex(p, obj_offset);
1890 if (!revidx)
1891 return OBJ_BAD;
1892 sha1 = nth_packed_object_sha1(p, revidx->nr);
1893 mark_bad_packed_object(p, sha1);
1894 type = sha1_object_info(sha1, NULL);
1895 if (type <= OBJ_NONE)
1896 return OBJ_BAD;
1897 return type;
1898}
1899
790d96c0
TR
1900#define POI_STACK_PREALLOC 64
1901
90191d37
JK
1902static enum object_type packed_to_object_type(struct packed_git *p,
1903 off_t obj_offset,
1904 enum object_type type,
1905 struct pack_window **w_curs,
1906 off_t curpos)
1f688557 1907{
790d96c0
TR
1908 off_t small_poi_stack[POI_STACK_PREALLOC];
1909 off_t *poi_stack = small_poi_stack;
1910 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
5db47c2b 1911
790d96c0
TR
1912 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1913 off_t base_offset;
90191d37 1914 unsigned long size;
790d96c0
TR
1915 /* Push the object we're going to leave behind */
1916 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1917 poi_stack_alloc = alloc_nr(poi_stack_nr);
b32fa95f 1918 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
790d96c0
TR
1919 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1920 } else {
1921 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1922 }
1923 poi_stack[poi_stack_nr++] = obj_offset;
1924 /* If parsing the base offset fails, just unwind */
90191d37 1925 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
790d96c0
TR
1926 if (!base_offset)
1927 goto unwind;
1928 curpos = obj_offset = base_offset;
90191d37 1929 type = unpack_object_header(p, w_curs, &curpos, &size);
790d96c0
TR
1930 if (type <= OBJ_NONE) {
1931 /* If getting the base itself fails, we first
1932 * retry the base, otherwise unwind */
1933 type = retry_bad_packed_offset(p, base_offset);
1934 if (type > OBJ_NONE)
1935 goto out;
1936 goto unwind;
1937 }
1938 }
1939
21666f1a 1940 switch (type) {
790d96c0 1941 case OBJ_BAD:
a733cb60 1942 case OBJ_COMMIT:
a733cb60 1943 case OBJ_TREE:
a733cb60 1944 case OBJ_BLOB:
a733cb60 1945 case OBJ_TAG:
a69d0943 1946 break;
1f688557 1947 default:
3d77d877
NP
1948 error("unknown object type %i at offset %"PRIuMAX" in %s",
1949 type, (uintmax_t)obj_offset, p->pack_name);
1950 type = OBJ_BAD;
1f688557 1951 }
790d96c0
TR
1952
1953out:
1954 if (poi_stack != small_poi_stack)
1955 free(poi_stack);
21666f1a 1956 return type;
790d96c0
TR
1957
1958unwind:
1959 while (poi_stack_nr) {
1960 obj_offset = poi_stack[--poi_stack_nr];
1961 type = retry_bad_packed_offset(p, obj_offset);
1962 if (type > OBJ_NONE)
1963 goto out;
1964 }
1965 type = OBJ_BAD;
1966 goto out;
1f688557
JH
1967}
1968
90191d37 1969static int packed_object_info(struct packed_git *p, off_t obj_offset,
23c339c0 1970 struct object_info *oi)
90191d37
JK
1971{
1972 struct pack_window *w_curs = NULL;
1973 unsigned long size;
1974 off_t curpos = obj_offset;
1975 enum object_type type;
1976
412916ee
JK
1977 /*
1978 * We always get the representation type, but only convert it to
1979 * a "real" type later if the caller is interested.
1980 */
90191d37
JK
1981 type = unpack_object_header(p, &w_curs, &curpos, &size);
1982
23c339c0 1983 if (oi->sizep) {
90191d37
JK
1984 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1985 off_t tmp_pos = curpos;
1986 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1987 type, obj_offset);
1988 if (!base_offset) {
1989 type = OBJ_BAD;
1990 goto out;
1991 }
23c339c0
JK
1992 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1993 if (*oi->sizep == 0) {
90191d37
JK
1994 type = OBJ_BAD;
1995 goto out;
1996 }
1997 } else {
23c339c0 1998 *oi->sizep = size;
90191d37
JK
1999 }
2000 }
2001
23c339c0 2002 if (oi->disk_sizep) {
90191d37 2003 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
23c339c0 2004 *oi->disk_sizep = revidx[1].offset - obj_offset;
90191d37
JK
2005 }
2006
23c339c0
JK
2007 if (oi->typep) {
2008 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
2009 if (*oi->typep < 0) {
412916ee
JK
2010 type = OBJ_BAD;
2011 goto out;
2012 }
2013 }
90191d37 2014
5d642e75
JK
2015 if (oi->delta_base_sha1) {
2016 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2017 const unsigned char *base;
2018
2019 base = get_delta_base_sha1(p, &w_curs, curpos,
2020 type, obj_offset);
2021 if (!base) {
2022 type = OBJ_BAD;
2023 goto out;
2024 }
2025
2026 hashcpy(oi->delta_base_sha1, base);
2027 } else
2028 hashclr(oi->delta_base_sha1);
2029 }
2030
90191d37
JK
2031out:
2032 unuse_pack(&w_curs);
2033 return type;
2034}
2035
eb950c19 2036static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 2037 struct pack_window **w_curs,
c4001d92 2038 off_t curpos,
eb950c19 2039 unsigned long size)
de530aaa
SP
2040{
2041 int st;
ef49a7a0 2042 git_zstream stream;
079afb18 2043 unsigned char *buffer, *in;
de530aaa 2044
735efde8
NTND
2045 buffer = xmallocz_gently(size);
2046 if (!buffer)
2047 return NULL;
de530aaa 2048 memset(&stream, 0, sizeof(stream));
de530aaa 2049 stream.next_out = buffer;
39eea7bd 2050 stream.avail_out = size + 1;
de530aaa 2051
39c68542 2052 git_inflate_init(&stream);
079afb18 2053 do {
2b87c45b 2054 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 2055 stream.next_in = in;
39c68542 2056 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
2057 if (!stream.avail_out)
2058 break; /* the payload is larger than it should be */
2b87c45b 2059 curpos += stream.next_in - in;
079afb18 2060 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 2061 git_inflate_end(&stream);
de530aaa
SP
2062 if ((st != Z_STREAM_END) || stream.total_out != size) {
2063 free(buffer);
2064 return NULL;
2065 }
2066
2067 return buffer;
2068}
2069
e5e01619
LT
2070#define MAX_DELTA_CACHE (256)
2071
18bdec11 2072static size_t delta_base_cached;
5e08ecbf
NP
2073
2074static struct delta_base_cache_lru_list {
2075 struct delta_base_cache_lru_list *prev;
2076 struct delta_base_cache_lru_list *next;
2077} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
2078
e5e01619 2079static struct delta_base_cache_entry {
5e08ecbf
NP
2080 struct delta_base_cache_lru_list lru;
2081 void *data;
e5e01619
LT
2082 struct packed_git *p;
2083 off_t base_offset;
2084 unsigned long size;
e5e01619
LT
2085 enum object_type type;
2086} delta_base_cache[MAX_DELTA_CACHE];
2087
2088static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
2089{
2090 unsigned long hash;
2091
56a1a3ab 2092 hash = (unsigned long)(intptr_t)p + (unsigned long)base_offset;
e5e01619 2093 hash += (hash >> 8) + (hash >> 16);
3358004a 2094 return hash % MAX_DELTA_CACHE;
e5e01619
LT
2095}
2096
84dd81c1
TR
2097static struct delta_base_cache_entry *
2098get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
5266d369
JH
2099{
2100 unsigned long hash = pack_entry_hash(p, base_offset);
84dd81c1
TR
2101 return delta_base_cache + hash;
2102}
2103
2104static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
2105 struct packed_git *p, off_t base_offset)
2106{
5266d369
JH
2107 return (ent->data && ent->p == p && ent->base_offset == base_offset);
2108}
2109
84dd81c1
TR
2110static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2111{
2112 struct delta_base_cache_entry *ent;
2113 ent = get_delta_base_cache_entry(p, base_offset);
2114 return eq_delta_base_cache_entry(ent, p, base_offset);
2115}
2116
2117static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2118{
2119 ent->data = NULL;
2120 ent->lru.next->prev = ent->lru.prev;
2121 ent->lru.prev->next = ent->lru.next;
2122 delta_base_cached -= ent->size;
2123}
2124
62f255ad 2125static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 2126 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 2127{
84dd81c1 2128 struct delta_base_cache_entry *ent;
e5e01619 2129 void *ret;
e5e01619 2130
84dd81c1
TR
2131 ent = get_delta_base_cache_entry(p, base_offset);
2132
2133 if (!eq_delta_base_cache_entry(ent, p, base_offset))
749bc58c 2134 return unpack_entry(p, base_offset, type, base_size);
e5e01619 2135
84dd81c1
TR
2136 ret = ent->data;
2137
2138 if (!keep_cache)
2139 clear_delta_base_cache_entry(ent);
2140 else
182af834 2141 ret = xmemdupz(ent->data, ent->size);
e5e01619
LT
2142 *type = ent->type;
2143 *base_size = ent->size;
2144 return ret;
62f255ad
LT
2145}
2146
18bdec11
SP
2147static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2148{
2149 if (ent->data) {
2150 free(ent->data);
2151 ent->data = NULL;
5e08ecbf
NP
2152 ent->lru.next->prev = ent->lru.prev;
2153 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
2154 delta_base_cached -= ent->size;
2155 }
2156}
2157
3d20c636
SP
2158void clear_delta_base_cache(void)
2159{
2160 unsigned long p;
2161 for (p = 0; p < MAX_DELTA_CACHE; p++)
2162 release_delta_base_cache(&delta_base_cache[p]);
2163}
2164
62f255ad
LT
2165static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2166 void *base, unsigned long base_size, enum object_type type)
2167{
5e08ecbf 2168 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 2169 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 2170 struct delta_base_cache_lru_list *lru;
e5e01619 2171
18bdec11
SP
2172 release_delta_base_cache(ent);
2173 delta_base_cached += base_size;
5e08ecbf
NP
2174
2175 for (lru = delta_base_cache_lru.next;
2176 delta_base_cached > delta_base_cache_limit
2177 && lru != &delta_base_cache_lru;
2178 lru = lru->next) {
2179 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
2180 if (f->type == OBJ_BLOB)
2181 release_delta_base_cache(f);
2182 }
5e08ecbf
NP
2183 for (lru = delta_base_cache_lru.next;
2184 delta_base_cached > delta_base_cache_limit
2185 && lru != &delta_base_cache_lru;
2186 lru = lru->next) {
2187 struct delta_base_cache_entry *f = (void *)lru;
2188 release_delta_base_cache(f);
2189 }
18bdec11 2190
e5e01619
LT
2191 ent->p = p;
2192 ent->base_offset = base_offset;
2193 ent->type = type;
2194 ent->data = base;
2195 ent->size = base_size;
5e08ecbf
NP
2196 ent->lru.next = &delta_base_cache_lru;
2197 ent->lru.prev = delta_base_cache_lru.prev;
2198 delta_base_cache_lru.prev->next = &ent->lru;
2199 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
2200}
2201
c2c5b270
CC
2202static void *read_object(const unsigned char *sha1, enum object_type *type,
2203 unsigned long *size);
2204
5f44324d
JH
2205static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2206{
67dc598e
KB
2207 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2208 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2209 p->pack_name, (uintmax_t)obj_offset);
5f44324d
JH
2210}
2211
0e8189e2
NP
2212int do_check_packed_object_crc;
2213
abe601bb
TR
2214#define UNPACK_ENTRY_STACK_PREALLOC 64
2215struct unpack_entry_stack_ent {
2216 off_t obj_offset;
2217 off_t curpos;
2218 unsigned long size;
2219};
2220
c4001d92 2221void *unpack_entry(struct packed_git *p, off_t obj_offset,
abe601bb 2222 enum object_type *final_type, unsigned long *final_size)
1f688557 2223{
03e79c88 2224 struct pack_window *w_curs = NULL;
c4001d92 2225 off_t curpos = obj_offset;
abe601bb
TR
2226 void *data = NULL;
2227 unsigned long size;
2228 enum object_type type;
2229 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2230 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2231 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2232 int base_from_cache = 0;
1f688557 2233
67dc598e 2234 write_pack_access_log(p, obj_offset);
5f44324d 2235
abe601bb
TR
2236 /* PHASE 1: drill down to the innermost base object */
2237 for (;;) {
2238 off_t base_offset;
2239 int i;
2240 struct delta_base_cache_entry *ent;
2241
77965f8b
NTND
2242 ent = get_delta_base_cache_entry(p, curpos);
2243 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2244 type = ent->type;
2245 data = ent->data;
2246 size = ent->size;
2247 clear_delta_base_cache_entry(ent);
2248 base_from_cache = 1;
2249 break;
2250 }
2251
abe601bb
TR
2252 if (do_check_packed_object_crc && p->index_version > 1) {
2253 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2254 unsigned long len = revidx[1].offset - obj_offset;
2255 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2256 const unsigned char *sha1 =
2257 nth_packed_object_sha1(p, revidx->nr);
2258 error("bad packed object CRC for %s",
2259 sha1_to_hex(sha1));
2260 mark_bad_packed_object(p, sha1);
2261 unuse_pack(&w_curs);
2262 return NULL;
2263 }
2264 }
2265
abe601bb
TR
2266 type = unpack_object_header(p, &w_curs, &curpos, &size);
2267 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2268 break;
2269
2270 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2271 if (!base_offset) {
2272 error("failed to validate delta base reference "
2273 "at offset %"PRIuMAX" from %s",
2274 (uintmax_t)curpos, p->pack_name);
2275 /* bail to phase 2, in hopes of recovery */
2276 data = NULL;
2277 break;
2278 }
2279
2280 /* push object, proceed to base */
2281 if (delta_stack_nr >= delta_stack_alloc
2282 && delta_stack == small_delta_stack) {
2283 delta_stack_alloc = alloc_nr(delta_stack_nr);
b32fa95f 2284 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
abe601bb
TR
2285 memcpy(delta_stack, small_delta_stack,
2286 sizeof(*delta_stack)*delta_stack_nr);
2287 } else {
2288 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2289 }
2290 i = delta_stack_nr++;
2291 delta_stack[i].obj_offset = obj_offset;
2292 delta_stack[i].curpos = curpos;
2293 delta_stack[i].size = size;
2294
2295 curpos = obj_offset = base_offset;
0e8189e2
NP
2296 }
2297
abe601bb
TR
2298 /* PHASE 2: handle the base */
2299 switch (type) {
eb32d236
NP
2300 case OBJ_OFS_DELTA:
2301 case OBJ_REF_DELTA:
abe601bb
TR
2302 if (data)
2303 die("BUG in unpack_entry: left loop at a valid delta");
4d703a1a 2304 break;
a733cb60 2305 case OBJ_COMMIT:
a733cb60 2306 case OBJ_TREE:
a733cb60 2307 case OBJ_BLOB:
a733cb60 2308 case OBJ_TAG:
abe601bb
TR
2309 if (!base_from_cache)
2310 data = unpack_compressed_entry(p, &w_curs, curpos, size);
4d703a1a 2311 break;
1f688557 2312 default:
8eca0b47
NP
2313 data = NULL;
2314 error("unknown object type %i at offset %"PRIuMAX" in %s",
abe601bb
TR
2315 type, (uintmax_t)obj_offset, p->pack_name);
2316 }
2317
2318 /* PHASE 3: apply deltas in order */
2319
2320 /* invariants:
2321 * 'data' holds the base data, or NULL if there was corruption
2322 */
2323 while (delta_stack_nr) {
2324 void *delta_data;
2325 void *base = data;
2326 unsigned long delta_size, base_size = size;
2327 int i;
2328
2329 data = NULL;
2330
2331 if (base)
2332 add_delta_base_cache(p, obj_offset, base, base_size, type);
2333
2334 if (!base) {
2335 /*
2336 * We're probably in deep shit, but let's try to fetch
2337 * the required base anyway from another pack or loose.
2338 * This is costly but should happen only in the presence
2339 * of a corrupted pack, and is better than failing outright.
2340 */
2341 struct revindex_entry *revidx;
2342 const unsigned char *base_sha1;
2343 revidx = find_pack_revindex(p, obj_offset);
2344 if (revidx) {
2345 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2346 error("failed to read delta base object %s"
2347 " at offset %"PRIuMAX" from %s",
2348 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2349 p->pack_name);
2350 mark_bad_packed_object(p, base_sha1);
2351 base = read_object(base_sha1, &type, &base_size);
2352 }
2353 }
2354
2355 i = --delta_stack_nr;
2356 obj_offset = delta_stack[i].obj_offset;
2357 curpos = delta_stack[i].curpos;
2358 delta_size = delta_stack[i].size;
2359
2360 if (!base)
2361 continue;
2362
2363 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2364
2365 if (!delta_data) {
2366 error("failed to unpack compressed delta "
2367 "at offset %"PRIuMAX" from %s",
2368 (uintmax_t)curpos, p->pack_name);
abe601bb
TR
2369 data = NULL;
2370 continue;
2371 }
2372
2373 data = patch_delta(base, base_size,
2374 delta_data, delta_size,
2375 &size);
1ee886c1
JK
2376
2377 /*
2378 * We could not apply the delta; warn the user, but keep going.
2379 * Our failure will be noticed either in the next iteration of
2380 * the loop, or if this is the final delta, in the caller when
2381 * we return NULL. Those code paths will take care of making
2382 * a more explicit warning and retrying with another copy of
2383 * the object.
2384 */
abe601bb 2385 if (!data)
1ee886c1 2386 error("failed to apply delta");
abe601bb 2387
4b8f772c 2388 free(delta_data);
1f688557 2389 }
abe601bb
TR
2390
2391 *final_type = type;
2392 *final_size = size;
2393
03e79c88 2394 unuse_pack(&w_curs);
019d1e65
NTND
2395
2396 if (delta_stack != small_delta_stack)
2397 free(delta_stack);
2398
21666f1a 2399 return data;
1f688557
JH
2400}
2401
d079837e 2402const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 2403 uint32_t n)
9a217f2a 2404{
42873078 2405 const unsigned char *index = p->index_data;
d079837e
SP
2406 if (!index) {
2407 if (open_pack_index(p))
2408 return NULL;
2409 index = p->index_data;
2410 }
57059091 2411 if (n >= p->num_objects)
d72308e0 2412 return NULL;
74e34e1f
NP
2413 index += 4 * 256;
2414 if (p->index_version == 1) {
2415 return index + 24 * n + 4;
2416 } else {
2417 index += 8;
2418 return index + 20 * n;
2419 }
2420}
2421
47fe3f6e
JK
2422void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
2423{
2424 const unsigned char *ptr = vptr;
2425 const unsigned char *start = p->index_data;
2426 const unsigned char *end = start + p->index_size;
2427 if (ptr < start)
7465feba 2428 die(_("offset before start of pack index for %s (corrupt index?)"),
47fe3f6e
JK
2429 p->pack_name);
2430 /* No need to check for underflow; .idx files must be at least 8 bytes */
2431 if (ptr >= end - 8)
7465feba 2432 die(_("offset beyond end of pack index for %s (truncated index?)"),
47fe3f6e
JK
2433 p->pack_name);
2434}
2435
99093238 2436off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
2437{
2438 const unsigned char *index = p->index_data;
2439 index += 4 * 256;
2440 if (p->index_version == 1) {
2441 return ntohl(*((uint32_t *)(index + 24 * n)));
2442 } else {
2443 uint32_t off;
2444 index += 8 + p->num_objects * (20 + 4);
2445 off = ntohl(*((uint32_t *)(index + 4 * n)));
2446 if (!(off & 0x80000000))
2447 return off;
2448 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
47fe3f6e 2449 check_pack_index_ptr(p, index);
74e34e1f
NP
2450 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2451 ntohl(*((uint32_t *)(index + 4)));
2452 }
9a217f2a
JH
2453}
2454
c4001d92 2455off_t find_pack_entry_one(const unsigned char *sha1,
43057304 2456 struct packed_git *p)
1f688557 2457{
42873078 2458 const uint32_t *level1_ofs = p->index_data;
42873078 2459 const unsigned char *index = p->index_data;
628522ec
JH
2460 unsigned hi, lo, stride;
2461 static int use_lookup = -1;
2462 static int debug_lookup = -1;
2463
2464 if (debug_lookup < 0)
2465 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 2466
d079837e
SP
2467 if (!index) {
2468 if (open_pack_index(p))
2469 return 0;
2470 level1_ofs = p->index_data;
2471 index = p->index_data;
2472 }
74e34e1f
NP
2473 if (p->index_version > 1) {
2474 level1_ofs += 2;
2475 index += 8;
2476 }
42873078 2477 index += 4 * 256;
74e34e1f
NP
2478 hi = ntohl(level1_ofs[*sha1]);
2479 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2480 if (p->index_version > 1) {
2481 stride = 20;
2482 } else {
2483 stride = 24;
2484 index += 4;
2485 }
2486
2487 if (debug_lookup)
6e1c2344 2488 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2489 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2490
2491 if (use_lookup < 0)
2492 use_lookup = !!getenv("GIT_USE_LOOKUP");
2493 if (use_lookup) {
2494 int pos = sha1_entry_pos(index, stride, 0,
2495 lo, hi, p->num_objects, sha1);
2496 if (pos < 0)
2497 return 0;
2498 return nth_packed_object_offset(p, pos);
2499 }
1f688557
JH
2500
2501 do {
74e34e1f 2502 unsigned mi = (lo + hi) / 2;
628522ec
JH
2503 int cmp = hashcmp(index + mi * stride, sha1);
2504
2505 if (debug_lookup)
2506 printf("lo %u hi %u rg %u mi %u\n",
2507 lo, hi, hi - lo, mi);
43057304 2508 if (!cmp)
74e34e1f 2509 return nth_packed_object_offset(p, mi);
1f688557
JH
2510 if (cmp > 0)
2511 hi = mi;
2512 else
2513 lo = mi+1;
2514 } while (lo < hi);
2515 return 0;
2516}
2517
4c080182 2518int is_pack_valid(struct packed_git *p)
d131b7af
SP
2519{
2520 /* An already open pack is known to be valid. */
2521 if (p->pack_fd != -1)
2522 return 1;
2523
2524 /* If the pack has one window completely covering the
2525 * file size, the pack is known to be valid even if
2526 * the descriptor is not currently open.
2527 */
2528 if (p->windows) {
2529 struct pack_window *w = p->windows;
2530
2531 if (!w->offset && w->len == p->pack_size)
2532 return 1;
2533 }
2534
2535 /* Force the pack to open to prove its valid. */
2536 return !open_packed_git(p);
2537}
2538
95099731
NTND
2539static int fill_pack_entry(const unsigned char *sha1,
2540 struct pack_entry *e,
2541 struct packed_git *p)
2542{
2543 off_t offset;
2544
2545 if (p->num_bad_objects) {
2546 unsigned i;
2547 for (i = 0; i < p->num_bad_objects; i++)
2548 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2549 return 0;
2550 }
2551
2552 offset = find_pack_entry_one(sha1, p);
2553 if (!offset)
2554 return 0;
2555
2556 /*
2557 * We are about to tell the caller where they can locate the
2558 * requested object. We better make sure the packfile is
2559 * still here and can be accessed before supplying that
2560 * answer, as it may have been deleted since the index was
2561 * loaded!
2562 */
319b678a 2563 if (!is_pack_valid(p))
95099731 2564 return 0;
95099731
NTND
2565 e->offset = offset;
2566 e->p = p;
2567 hashcpy(e->sha1, sha1);
2568 return 1;
2569}
2570
d40d535b
MH
2571/*
2572 * Iff a pack file contains the object named by sha1, return true and
2573 * store its location to e.
2574 */
4d6acb70 2575static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557
JH
2576{
2577 struct packed_git *p;
43057304 2578
1f688557 2579 prepare_packed_git();
f7c22cc6
NP
2580 if (!packed_git)
2581 return 0;
1f688557 2582
c01f51cc
NTND
2583 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2584 return 1;
8eca0b47 2585
c01f51cc 2586 for (p = packed_git; p; p = p->next) {
1b1005d1
MH
2587 if (p == last_found_pack)
2588 continue; /* we already checked this one */
f7c22cc6 2589
1b1005d1
MH
2590 if (fill_pack_entry(sha1, e, p)) {
2591 last_found_pack = p;
2592 return 1;
2593 }
c01f51cc 2594 }
1f688557
JH
2595 return 0;
2596}
2597
a6080a0a 2598struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2599 struct packed_git *packs)
2600{
2601 struct packed_git *p;
bf592c50
DB
2602
2603 for (p = packs; p; p = p->next) {
43057304 2604 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2605 return p;
2606 }
2607 return NULL;
21666f1a 2608
bf592c50
DB
2609}
2610
052fe5ea 2611static int sha1_loose_object_info(const unsigned char *sha1,
46f03448
KN
2612 struct object_info *oi,
2613 int flags)
65c2e0c3 2614{
46f03448
KN
2615 int status = 0;
2616 unsigned long mapsize;
65c2e0c3 2617 void *map;
ef49a7a0 2618 git_zstream stream;
d65a16f6 2619 char hdr[32];
46f03448 2620 struct strbuf hdrbuf = STRBUF_INIT;
65c2e0c3 2621
5d642e75
JK
2622 if (oi->delta_base_sha1)
2623 hashclr(oi->delta_base_sha1);
2624
052fe5ea
JK
2625 /*
2626 * If we don't care about type or size, then we don't
4ef8d1dd
JH
2627 * need to look inside the object at all. Note that we
2628 * do not optimize out the stat call, even if the
2629 * caller doesn't care about the disk-size, since our
2630 * return value implicitly indicates whether the
2631 * object even exists.
052fe5ea 2632 */
46f03448 2633 if (!oi->typep && !oi->typename && !oi->sizep) {
4ef8d1dd
JH
2634 struct stat st;
2635 if (stat_sha1_file(sha1, &st) < 0)
2636 return -1;
2637 if (oi->disk_sizep)
23c339c0 2638 *oi->disk_sizep = st.st_size;
052fe5ea
JK
2639 return 0;
2640 }
2641
bb6b8e4f 2642 map = map_sha1_file(sha1, &mapsize);
f0df4ed5 2643 if (!map)
dbea72a8 2644 return -1;
23c339c0
JK
2645 if (oi->disk_sizep)
2646 *oi->disk_sizep = mapsize;
46f03448
KN
2647 if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
2648 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2649 status = error("unable to unpack %s header with --allow-unknown-type",
2650 sha1_to_hex(sha1));
2651 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
36e4d74a
JH
2652 status = error("unable to unpack %s header",
2653 sha1_to_hex(sha1));
46f03448
KN
2654 if (status < 0)
2655 ; /* Do nothing */
2656 else if (hdrbuf.len) {
2657 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2658 status = error("unable to parse %s header with --allow-unknown-type",
2659 sha1_to_hex(sha1));
2660 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
36e4d74a 2661 status = error("unable to parse %s header", sha1_to_hex(sha1));
39c68542 2662 git_inflate_end(&stream);
65c2e0c3 2663 munmap(map, mapsize);
46f03448 2664 if (status && oi->typep)
23c339c0 2665 *oi->typep = status;
46f03448 2666 strbuf_release(&hdrbuf);
052fe5ea 2667 return 0;
65c2e0c3
JH
2668}
2669
de7b5d62 2670int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
f0df4ed5 2671{
c4d9986f 2672 struct cached_object *co;
f0df4ed5 2673 struct pack_entry e;
5b086407 2674 int rtype;
46f03448 2675 enum object_type real_type;
1f7117ef 2676 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
f0df4ed5 2677
1f7117ef 2678 co = find_cached_object(real);
c4d9986f 2679 if (co) {
5b086407
JK
2680 if (oi->typep)
2681 *(oi->typep) = co->type;
9a490590
JH
2682 if (oi->sizep)
2683 *(oi->sizep) = co->size;
161f00e7
JK
2684 if (oi->disk_sizep)
2685 *(oi->disk_sizep) = 0;
5d642e75
JK
2686 if (oi->delta_base_sha1)
2687 hashclr(oi->delta_base_sha1);
46f03448
KN
2688 if (oi->typename)
2689 strbuf_addstr(oi->typename, typename(co->type));
9a490590 2690 oi->whence = OI_CACHED;
5b086407 2691 return 0;
c4d9986f
NTND
2692 }
2693
1f7117ef 2694 if (!find_pack_entry(real, &e)) {
ddd63e64 2695 /* Most likely it's a loose object. */
46f03448 2696 if (!sha1_loose_object_info(real, oi, flags)) {
9a490590 2697 oi->whence = OI_LOOSE;
5b086407 2698 return 0;
9a490590 2699 }
ddd63e64
SG
2700
2701 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 2702 reprepare_packed_git();
1f7117ef 2703 if (!find_pack_entry(real, &e))
052fe5ea 2704 return -1;
f0df4ed5 2705 }
3d77d877 2706
46f03448
KN
2707 /*
2708 * packed_object_info() does not follow the delta chain to
2709 * find out the real type, unless it is given oi->typep.
2710 */
2711 if (oi->typename && !oi->typep)
2712 oi->typep = &real_type;
2713
23c339c0 2714 rtype = packed_object_info(e.p, e.offset, oi);
412916ee 2715 if (rtype < 0) {
1f7117ef 2716 mark_bad_packed_object(e.p, real);
46f03448
KN
2717 if (oi->typep == &real_type)
2718 oi->typep = NULL;
1f7117ef 2719 return sha1_object_info_extended(real, oi, 0);
5266d369
JH
2720 } else if (in_delta_base_cache(e.p, e.offset)) {
2721 oi->whence = OI_DBCACHED;
9a490590
JH
2722 } else {
2723 oi->whence = OI_PACKED;
2724 oi->u.packed.offset = e.offset;
2725 oi->u.packed.pack = e.p;
2726 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2727 rtype == OBJ_OFS_DELTA);
3d77d877 2728 }
46f03448
KN
2729 if (oi->typename)
2730 strbuf_addstr(oi->typename, typename(*oi->typep));
2731 if (oi->typep == &real_type)
2732 oi->typep = NULL;
3d77d877 2733
5b086407 2734 return 0;
f0df4ed5
JS
2735}
2736
3fc0dca9 2737/* returns enum object_type or negative */
9a490590
JH
2738int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2739{
5b086407 2740 enum object_type type;
d099b717 2741 struct object_info oi = {NULL};
9a490590 2742
5b086407 2743 oi.typep = &type;
9a490590 2744 oi.sizep = sizep;
de7b5d62 2745 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
5b086407
JK
2746 return -1;
2747 return type;
9a490590
JH
2748}
2749
21666f1a
NP
2750static void *read_packed_sha1(const unsigned char *sha1,
2751 enum object_type *type, unsigned long *size)
1f688557
JH
2752{
2753 struct pack_entry e;
8eca0b47 2754 void *data;
1f688557 2755
cd673c1f 2756 if (!find_pack_entry(sha1, &e))
1f688557 2757 return NULL;
8eca0b47
NP
2758 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2759 if (!data) {
2760 /*
2761 * We're probably in deep shit, but let's try to fetch
2762 * the required object anyway from another pack or loose.
2763 * This should happen only in the presence of a corrupted
2764 * pack, and is better than failing outright.
2765 */
2766 error("failed to read object %s at offset %"PRIuMAX" from %s",
2767 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2768 mark_bad_packed_object(e.p, sha1);
ac939109 2769 data = read_object(sha1, type, size);
8eca0b47
NP
2770 }
2771 return data;
1f688557
JH
2772}
2773
21666f1a
NP
2774int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2775 unsigned char *sha1)
d66b37bb
JH
2776{
2777 struct cached_object *co;
2778
21666f1a 2779 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2780 if (has_sha1_file(sha1) || find_cached_object(sha1))
2781 return 0;
c7353967 2782 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
d66b37bb
JH
2783 co = &cached_objects[cached_object_nr++];
2784 co->size = len;
21666f1a 2785 co->type = type;
efa13f7b
JH
2786 co->buf = xmalloc(len);
2787 memcpy(co->buf, buf, len);
d66b37bb
JH
2788 hashcpy(co->sha1, sha1);
2789 return 0;
2790}
2791
c2c5b270
CC
2792static void *read_object(const unsigned char *sha1, enum object_type *type,
2793 unsigned long *size)
0fcfd160
LT
2794{
2795 unsigned long mapsize;
2796 void *map, *buf;
d66b37bb
JH
2797 struct cached_object *co;
2798
2799 co = find_cached_object(sha1);
2800 if (co) {
21666f1a 2801 *type = co->type;
d66b37bb 2802 *size = co->size;
182af834 2803 return xmemdupz(co->buf, co->size);
d66b37bb 2804 }
0fcfd160 2805
8276c007
PE
2806 buf = read_packed_sha1(sha1, type, size);
2807 if (buf)
2808 return buf;
bb6b8e4f 2809 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2810 if (map) {
7efbff75 2811 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2812 munmap(map, mapsize);
2813 return buf;
2814 }
637cdd9d 2815 reprepare_packed_git();
8276c007 2816 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2817}
2818
b6c4cecc
JH
2819/*
2820 * This function dies on corrupt objects; the callers who want to
2821 * deal with them should arrange to call read_object() and give error
2822 * messages themselves.
2823 */
5bf29b95
JH
2824void *read_sha1_file_extended(const unsigned char *sha1,
2825 enum object_type *type,
2826 unsigned long *size,
2827 unsigned flag)
ac939109 2828{
3ba7a065 2829 void *data;
b6c4cecc 2830 const struct packed_git *p;
bf93eea0 2831 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
b6c4cecc 2832
3ba7a065
JH
2833 errno = 0;
2834 data = read_object(repl, type, size);
4bbf5a26 2835 if (data)
b6c4cecc 2836 return data;
68095570 2837
25f3af3f 2838 if (errno && errno != ENOENT)
3ba7a065
JH
2839 die_errno("failed to read object %s", sha1_to_hex(sha1));
2840
68095570 2841 /* die if we replaced an object with one that does not exist */
b6c4cecc 2842 if (repl != sha1)
68095570
CC
2843 die("replacement %s not found for %s",
2844 sha1_to_hex(repl), sha1_to_hex(sha1));
2845
b6c4cecc 2846 if (has_loose_object(repl)) {
30d6c6ea
MH
2847 const char *path = sha1_file_name(sha1);
2848
b6c4cecc
JH
2849 die("loose object %s (stored in %s) is corrupt",
2850 sha1_to_hex(repl), path);
e8b15e61 2851 }
68095570 2852
b6c4cecc
JH
2853 if ((p = has_packed_and_bad(repl)) != NULL)
2854 die("packed object %s (stored in %s) is corrupt",
2855 sha1_to_hex(repl), p->pack_name);
f5552aee 2856
b6c4cecc 2857 return NULL;
ac939109
NP
2858}
2859
40469ee9 2860void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2861 const char *required_type_name,
40469ee9
JH
2862 unsigned long *size,
2863 unsigned char *actual_sha1_return)
f4913f91 2864{
21666f1a 2865 enum object_type type, required_type;
f4913f91
JH
2866 void *buffer;
2867 unsigned long isize;
40469ee9 2868 unsigned char actual_sha1[20];
f4913f91 2869
21666f1a 2870 required_type = type_from_string(required_type_name);
e702496e 2871 hashcpy(actual_sha1, sha1);
40469ee9
JH
2872 while (1) {
2873 int ref_length = -1;
2874 const char *ref_type = NULL;
f4913f91 2875
21666f1a 2876 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2877 if (!buffer)
2878 return NULL;
21666f1a 2879 if (type == required_type) {
40469ee9
JH
2880 *size = isize;
2881 if (actual_sha1_return)
e702496e 2882 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2883 return buffer;
2884 }
2885 /* Handle references */
21666f1a 2886 else if (type == OBJ_COMMIT)
40469ee9 2887 ref_type = "tree ";
21666f1a 2888 else if (type == OBJ_TAG)
40469ee9
JH
2889 ref_type = "object ";
2890 else {
2891 free(buffer);
2892 return NULL;
2893 }
2894 ref_length = strlen(ref_type);
f4913f91 2895
50974ec9
MK
2896 if (ref_length + 40 > isize ||
2897 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2898 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2899 free(buffer);
2900 return NULL;
2901 }
1cf58e72 2902 free(buffer);
40469ee9
JH
2903 /* Now we have the ID of the referred-to object in
2904 * actual_sha1. Check again. */
f4913f91 2905 }
f4913f91
JH
2906}
2907
ce9fbf16 2908static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2909 const char *type, unsigned char *sha1,
d65a16f6 2910 char *hdr, int *hdrlen)
d410c0f5 2911{
9126f009 2912 git_SHA_CTX c;
d410c0f5
JH
2913
2914 /* Generate the header */
ef1286d3 2915 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
d410c0f5
JH
2916
2917 /* Sha1.. */
9126f009
NP
2918 git_SHA1_Init(&c);
2919 git_SHA1_Update(&c, hdr, *hdrlen);
2920 git_SHA1_Update(&c, buf, len);
2921 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2922}
2923
230f1322 2924/*
5a688fe4 2925 * Move the just written object into its final resting place.
230f1322 2926 */
cb5add58 2927int finalize_object_file(const char *tmpfile, const char *filename)
230f1322 2928{
e32c0a9c 2929 int ret = 0;
5a688fe4 2930
348df166 2931 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
2932 goto try_rename;
2933 else if (link(tmpfile, filename))
e32c0a9c 2934 ret = errno;
7ebb6fca
LT
2935
2936 /*
2937 * Coda hack - coda doesn't like cross-directory links,
2938 * so we fall back to a rename, which will mean that it
2939 * won't be able to check collisions, but that's not a
2940 * big deal.
2941 *
2942 * The same holds for FAT formatted media.
2943 *
3be1f18e 2944 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
2945 * left to unlink.
2946 */
2947 if (ret && ret != EEXIST) {
be66a6c4 2948 try_rename:
7ebb6fca 2949 if (!rename(tmpfile, filename))
3be1f18e 2950 goto out;
9e48b389 2951 ret = errno;
230f1322 2952 }
691f1a28 2953 unlink_or_warn(tmpfile);
230f1322
LT
2954 if (ret) {
2955 if (ret != EEXIST) {
7616c6ca 2956 return error_errno("unable to write sha1 filename %s", filename);
230f1322
LT
2957 }
2958 /* FIXME!!! Collision check here ? */
2959 }
2960
3be1f18e 2961out:
5256b006 2962 if (adjust_shared_perm(filename))
5a688fe4 2963 return error("unable to set permission to '%s'", filename);
230f1322
LT
2964 return 0;
2965}
2966
4d548150
LT
2967static int write_buffer(int fd, const void *buf, size_t len)
2968{
d34cf19b 2969 if (write_in_full(fd, buf, len) < 0)
7616c6ca 2970 return error_errno("file write error");
4d548150
LT
2971 return 0;
2972}
2973
ce9fbf16 2974int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2975 unsigned char *sha1)
2976{
d65a16f6 2977 char hdr[32];
ef1286d3 2978 int hdrlen = sizeof(hdr);
abdc3fc8
RS
2979 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2980 return 0;
2981}
2982
e9039dd3
LT
2983/* Finalize a file on disk, and close it. */
2984static void close_sha1_file(int fd)
2985{
aafe9fba
LT
2986 if (fsync_object_files)
2987 fsync_or_die(fd, "sha1 file");
e9039dd3 2988 if (close(fd) != 0)
d824cbba 2989 die_errno("error when closing sha1 file");
e9039dd3
LT
2990}
2991
5723fe7e
LT
2992/* Size of directory component, including the ending '/' */
2993static inline int directory_size(const char *filename)
2994{
2995 const char *s = strrchr(filename, '/');
2996 if (!s)
2997 return 0;
2998 return s - filename + 1;
2999}
3000
3001/*
3002 * This creates a temporary file in the same directory as the final
3003 * 'filename'
3004 *
3005 * We want to avoid cross-directory filename renames, because those
3006 * can have problems on various filesystems (FAT, NFS, Coda).
3007 */
d4b3d11a 3008static int create_tmpfile(struct strbuf *tmp, const char *filename)
5723fe7e
LT
3009{
3010 int fd, dirlen = directory_size(filename);
3011
d4b3d11a
JK
3012 strbuf_reset(tmp);
3013 strbuf_add(tmp, filename, dirlen);
3014 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3015 fd = git_mkstemp_mode(tmp->buf, 0444);
cbacbf4e 3016 if (fd < 0 && dirlen && errno == ENOENT) {
d4b3d11a
JK
3017 /*
3018 * Make sure the directory exists; note that the contents
3019 * of the buffer are undefined after mkstemp returns an
3020 * error, so we have to rewrite the whole buffer from
3021 * scratch.
3022 */
3023 strbuf_reset(tmp);
3024 strbuf_add(tmp, filename, dirlen - 1);
3025 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
b2476a60 3026 return -1;
d4b3d11a 3027 if (adjust_shared_perm(tmp->buf))
5723fe7e
LT
3028 return -1;
3029
3030 /* Try again */
d4b3d11a
JK
3031 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3032 fd = git_mkstemp_mode(tmp->buf, 0444);
5723fe7e
LT
3033 }
3034 return fd;
3035}
3036
bbac7311 3037static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 3038 const void *buf, unsigned long len, time_t mtime)
0fcfd160 3039{
915308b1 3040 int fd, ret;
9892beba 3041 unsigned char compressed[4096];
ef49a7a0 3042 git_zstream stream;
748af44c
NP
3043 git_SHA_CTX c;
3044 unsigned char parano_sha1[20];
d4b3d11a 3045 static struct strbuf tmp_file = STRBUF_INIT;
30d6c6ea 3046 const char *filename = sha1_file_name(sha1);
a44c9a5e 3047
d4b3d11a 3048 fd = create_tmpfile(&tmp_file, filename);
aac17941 3049 if (fd < 0) {
35243577 3050 if (errno == EACCES)
82247e9b 3051 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 3052 else
7616c6ca 3053 return error_errno("unable to create temporary file");
aac17941
LT
3054 }
3055
0fcfd160 3056 /* Set it up */
55bb5c91 3057 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 3058 stream.next_out = compressed;
9892beba 3059 stream.avail_out = sizeof(compressed);
748af44c 3060 git_SHA1_Init(&c);
a44c9a5e
LT
3061
3062 /* First header.. */
d65a16f6 3063 stream.next_in = (unsigned char *)hdr;
a44c9a5e 3064 stream.avail_in = hdrlen;
55bb5c91
JH
3065 while (git_deflate(&stream, 0) == Z_OK)
3066 ; /* nothing */
748af44c 3067 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
3068
3069 /* Then the data itself.. */
c00e657d 3070 stream.next_in = (void *)buf;
a44c9a5e 3071 stream.avail_in = len;
9892beba 3072 do {
748af44c 3073 unsigned char *in0 = stream.next_in;
55bb5c91 3074 ret = git_deflate(&stream, Z_FINISH);
748af44c 3075 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
3076 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3077 die("unable to write sha1 file");
3078 stream.next_out = compressed;
3079 stream.avail_out = sizeof(compressed);
3080 } while (ret == Z_OK);
3081
ac54c277
LT
3082 if (ret != Z_STREAM_END)
3083 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 3084 ret = git_deflate_end_gently(&stream);
ac54c277
LT
3085 if (ret != Z_OK)
3086 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
3087 git_SHA1_Final(parano_sha1, &c);
3088 if (hashcmp(sha1, parano_sha1) != 0)
3089 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 3090
e9039dd3 3091 close_sha1_file(fd);
0fcfd160 3092
bbac7311
NP
3093 if (mtime) {
3094 struct utimbuf utb;
3095 utb.actime = mtime;
3096 utb.modtime = mtime;
d4b3d11a 3097 if (utime(tmp_file.buf, &utb) < 0)
7616c6ca 3098 warning_errno("failed utime() on %s", tmp_file.buf);
bbac7311
NP
3099 }
3100
d4b3d11a 3101 return finalize_object_file(tmp_file.buf, filename);
0fcfd160 3102}
8237b185 3103
33d4221c
JK
3104static int freshen_loose_object(const unsigned char *sha1)
3105{
3106 return check_and_freshen(sha1, 1);
3107}
3108
3109static int freshen_packed_object(const unsigned char *sha1)
3110{
3111 struct pack_entry e;
ee1c6c34
JK
3112 if (!find_pack_entry(sha1, &e))
3113 return 0;
3114 if (e.p->freshened)
3115 return 1;
3116 if (!freshen_file(e.p->pack_name))
3117 return 0;
3118 e.p->freshened = 1;
3119 return 1;
33d4221c
JK
3120}
3121
1427a7ff 3122int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
bbac7311 3123{
bbac7311 3124 char hdr[32];
ef1286d3 3125 int hdrlen = sizeof(hdr);
bbac7311
NP
3126
3127 /* Normally if we have it in the pack then we do not bother writing
3128 * it out into .git/objects/??/?{38} file.
3129 */
3130 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
b5f52f37 3131 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
bbac7311
NP
3132 return 0;
3133 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3134}
3135
0c3db67c
ES
3136int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3137 unsigned char *sha1, unsigned flags)
3138{
3139 char *header;
3140 int hdrlen, status = 0;
3141
3142 /* type string, SP, %lu of the length plus NUL must fit this */
ef1286d3
JK
3143 hdrlen = strlen(type) + 32;
3144 header = xmalloc(hdrlen);
0c3db67c
ES
3145 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3146
3147 if (!(flags & HASH_WRITE_OBJECT))
3148 goto cleanup;
051086b9 3149 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
0c3db67c
ES
3150 goto cleanup;
3151 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3152
3153cleanup:
3154 free(header);
3155 return status;
3156}
3157
bbac7311
NP
3158int force_object_loose(const unsigned char *sha1, time_t mtime)
3159{
bbac7311
NP
3160 void *buf;
3161 unsigned long len;
3162 enum object_type type;
3163 char hdr[32];
3164 int hdrlen;
1fb23e65 3165 int ret;
bbac7311 3166
c529d75a 3167 if (has_loose_object(sha1))
bbac7311
NP
3168 return 0;
3169 buf = read_packed_sha1(sha1, &type, &len);
3170 if (!buf)
3171 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
ef1286d3 3172 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
1fb23e65
BS
3173 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3174 free(buf);
3175
3176 return ret;
bbac7311
NP
3177}
3178
bf592c50
DB
3179int has_pack_index(const unsigned char *sha1)
3180{
3181 struct stat st;
3182 if (stat(sha1_pack_index_name(sha1), &st))
3183 return 0;
3184 return 1;
bf592c50
DB
3185}
3186
cd673c1f
JH
3187int has_sha1_pack(const unsigned char *sha1)
3188{
3189 struct pack_entry e;
3190 return find_pack_entry(sha1, &e);
3191}
3192
0eeb077b 3193int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
8237b185 3194{
1f688557
JH
3195 struct pack_entry e;
3196
cd673c1f 3197 if (find_pack_entry(sha1, &e))
1f688557 3198 return 1;
45e8a748
JK
3199 if (has_loose_object(sha1))
3200 return 1;
0eeb077b
JK
3201 if (flags & HAS_SHA1_QUICK)
3202 return 0;
45e8a748
JK
3203 reprepare_packed_git();
3204 return find_pack_entry(sha1, &e);
b419aa25 3205}
3206
3207int has_object_file(const struct object_id *oid)
3208{
3209 return has_sha1_file(oid->hash);
8237b185 3210}
74400e71 3211
c879daa2
NTND
3212static void check_tree(const void *buf, size_t size)
3213{
3214 struct tree_desc desc;
3215 struct name_entry entry;
3216
3217 init_tree_desc(&desc, buf, size);
3218 while (tree_entry(&desc, &entry))
3219 /* do nothing
3220 * tree_entry() will die() on malformed entries */
3221 ;
3222}
3223
3224static void check_commit(const void *buf, size_t size)
3225{
3226 struct commit c;
3227 memset(&c, 0, sizeof(c));
3228 if (parse_commit_buffer(&c, buf, size))
3229 die("corrupt commit");
3230}
3231
3232static void check_tag(const void *buf, size_t size)
3233{
3234 struct tag t;
3235 memset(&t, 0, sizeof(t));
3236 if (parse_tag_buffer(&t, buf, size))
3237 die("corrupt tag");
3238}
3239
43df4f86 3240static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
3241 enum object_type type,
3242 const char *path, unsigned flags)
e7332f96 3243{
6c510bee 3244 int ret, re_allocated = 0;
c4ce46fc 3245 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 3246
7672db20 3247 if (!type)
edaec3fb 3248 type = OBJ_BLOB;
6c510bee
LT
3249
3250 /*
3251 * Convert blobs to git internal format
3252 */
43df4f86 3253 if ((type == OBJ_BLOB) && path) {
f285a2d7 3254 struct strbuf nbuf = STRBUF_INIT;
21e5ad50 3255 if (convert_to_git(path, buf, size, &nbuf,
5e12e78e 3256 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 3257 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
3258 re_allocated = 1;
3259 }
3260 }
c4ce46fc 3261 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
3262 if (type == OBJ_TREE)
3263 check_tree(buf, size);
3264 if (type == OBJ_COMMIT)
3265 check_commit(buf, size);
3266 if (type == OBJ_TAG)
3267 check_tag(buf, size);
3268 }
6c510bee 3269
7672db20 3270 if (write_object)
edaec3fb 3271 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 3272 else
edaec3fb 3273 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 3274 if (re_allocated)
6c510bee 3275 free(buf);
43df4f86
DP
3276 return ret;
3277}
3278
9035d75a
SP
3279static int index_stream_convert_blob(unsigned char *sha1, int fd,
3280 const char *path, unsigned flags)
3281{
3282 int ret;
3283 const int write_object = flags & HASH_WRITE_OBJECT;
3284 struct strbuf sbuf = STRBUF_INIT;
3285
3286 assert(path);
3287 assert(would_convert_to_git_filter_fd(path));
3288
3289 convert_to_git_filter_fd(path, fd, &sbuf,
3290 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3291
3292 if (write_object)
3293 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3294 sha1);
3295 else
3296 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3297 sha1);
3298 strbuf_release(&sbuf);
3299 return ret;
3300}
3301
7b41e1e1
JH
3302static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3303 const char *path, unsigned flags)
3304{
3305 struct strbuf sbuf = STRBUF_INIT;
3306 int ret;
3307
3308 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3309 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3310 else
3311 ret = -1;
3312 strbuf_release(&sbuf);
3313 return ret;
3314}
3315
ea68b0ce
DP
3316#define SMALL_FILE_SIZE (32*1024)
3317
7b41e1e1
JH
3318static int index_core(unsigned char *sha1, int fd, size_t size,
3319 enum object_type type, const char *path,
3320 unsigned flags)
43df4f86
DP
3321{
3322 int ret;
43df4f86 3323
7b41e1e1 3324 if (!size) {
f6a1e1e2 3325 ret = index_mem(sha1, "", size, type, path, flags);
ea68b0ce
DP
3326 } else if (size <= SMALL_FILE_SIZE) {
3327 char *buf = xmalloc(size);
3328 if (size == read_in_full(fd, buf, size))
c4ce46fc 3329 ret = index_mem(sha1, buf, size, type, path, flags);
ea68b0ce 3330 else
7616c6ca 3331 ret = error_errno("short read");
ea68b0ce 3332 free(buf);
08bda208 3333 } else {
43df4f86 3334 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
c4ce46fc 3335 ret = index_mem(sha1, buf, size, type, path, flags);
aac17941 3336 munmap(buf, size);
08bda208 3337 }
7b41e1e1
JH
3338 return ret;
3339}
3340
4dd1fbc7 3341/*
568508e7
JH
3342 * This creates one packfile per large blob unless bulk-checkin
3343 * machinery is "plugged".
4dd1fbc7
JH
3344 *
3345 * This also bypasses the usual "convert-to-git" dance, and that is on
3346 * purpose. We could write a streaming version of the converting
3347 * functions and insert that before feeding the data to fast-import
4f22b101
JK
3348 * (or equivalent in-core API described above). However, that is
3349 * somewhat complicated, as we do not know the size of the filter
3350 * result, which we need to know beforehand when writing a git object.
3351 * Since the primary motivation for trying to stream from the working
3352 * tree file and to avoid mmaping it in core is to deal with large
3353 * binary blobs, they generally do not want to get any conversion, and
3354 * callers should avoid this code path when filters are requested.
4dd1fbc7
JH
3355 */
3356static int index_stream(unsigned char *sha1, int fd, size_t size,
3357 enum object_type type, const char *path,
3358 unsigned flags)
3359{
568508e7 3360 return index_bulk_checkin(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
3361}
3362
7b41e1e1
JH
3363int index_fd(unsigned char *sha1, int fd, struct stat *st,
3364 enum object_type type, const char *path, unsigned flags)
3365{
3366 int ret;
7b41e1e1 3367
9079ab7c
SP
3368 /*
3369 * Call xsize_t() only when needed to avoid potentially unnecessary
3370 * die() for large files.
3371 */
9035d75a
SP
3372 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3373 ret = index_stream_convert_blob(sha1, fd, path, flags);
3374 else if (!S_ISREG(st->st_mode))
7b41e1e1 3375 ret = index_pipe(sha1, fd, type, path, flags);
9079ab7c 3376 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
7ce7c760 3377 (path && would_convert_to_git(path)))
9079ab7c
SP
3378 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3379 flags);
4dd1fbc7 3380 else
9079ab7c
SP
3381 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3382 flags);
43df4f86 3383 close(fd);
aac17941 3384 return ret;
74400e71 3385}
ec1fcc16 3386
c4ce46fc 3387int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
ec1fcc16
JH
3388{
3389 int fd;
b760d3aa 3390 struct strbuf sb = STRBUF_INIT;
ec1fcc16
JH
3391
3392 switch (st->st_mode & S_IFMT) {
3393 case S_IFREG:
3394 fd = open(path, O_RDONLY);
3395 if (fd < 0)
7616c6ca 3396 return error_errno("open(\"%s\")", path);
c4ce46fc 3397 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
ec1fcc16
JH
3398 return error("%s: failed to insert into database",
3399 path);
3400 break;
3401 case S_IFLNK:
7616c6ca
NTND
3402 if (strbuf_readlink(&sb, path, st->st_size))
3403 return error_errno("readlink(\"%s\")", path);
c4ce46fc 3404 if (!(flags & HASH_WRITE_OBJECT))
b760d3aa
LT
3405 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3406 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
ec1fcc16
JH
3407 return error("%s: failed to insert into database",
3408 path);
b760d3aa 3409 strbuf_release(&sb);
ec1fcc16 3410 break;
f35a6d3b
LT
3411 case S_IFDIR:
3412 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
3413 default:
3414 return error("%s: unsupported file type", path);
3415 }
3416 return 0;
3417}
a69e5429
JH
3418
3419int read_pack_header(int fd, struct pack_header *header)
3420{
c697ad14
HO
3421 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3422 /* "eof before pack header was fully read" */
3423 return PH_ERROR_EOF;
3424
a69e5429
JH
3425 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3426 /* "protocol error (pack signature mismatch detected)" */
3427 return PH_ERROR_PACK_SIGNATURE;
3428 if (!pack_version_ok(header->hdr_version))
3429 /* "protocol error (pack version unsupported)" */
3430 return PH_ERROR_PROTOCOL;
3431 return 0;
3432}
40d52ff7
JK
3433
3434void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3435{
3436 enum object_type type = sha1_object_info(sha1, NULL);
3437 if (type < 0)
3438 die("%s is not a valid object", sha1_to_hex(sha1));
3439 if (type != expect)
3440 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3441 typename(expect));
3442}
27e1e22d
JK
3443
3444static int for_each_file_in_obj_subdir(int subdir_nr,
3445 struct strbuf *path,
3446 each_loose_object_fn obj_cb,
3447 each_loose_cruft_fn cruft_cb,
3448 each_loose_subdir_fn subdir_cb,
3449 void *data)
3450{
3451 size_t baselen = path->len;
3452 DIR *dir = opendir(path->buf);
3453 struct dirent *de;
3454 int r = 0;
3455
3456 if (!dir) {
3457 if (errno == ENOENT)
3458 return 0;
7616c6ca 3459 return error_errno("unable to open %s", path->buf);
27e1e22d
JK
3460 }
3461
3462 while ((de = readdir(dir))) {
3463 if (is_dot_or_dotdot(de->d_name))
3464 continue;
3465
3466 strbuf_setlen(path, baselen);
3467 strbuf_addf(path, "/%s", de->d_name);
3468
3469 if (strlen(de->d_name) == 38) {
3470 char hex[41];
3471 unsigned char sha1[20];
3472
3473 snprintf(hex, sizeof(hex), "%02x%s",
3474 subdir_nr, de->d_name);
3475 if (!get_sha1_hex(hex, sha1)) {
3476 if (obj_cb) {
3477 r = obj_cb(sha1, path->buf, data);
3478 if (r)
3479 break;
3480 }
3481 continue;
3482 }
3483 }
3484
3485 if (cruft_cb) {
3486 r = cruft_cb(de->d_name, path->buf, data);
3487 if (r)
3488 break;
3489 }
3490 }
094c7e63 3491 closedir(dir);
27e1e22d 3492
094c7e63 3493 strbuf_setlen(path, baselen);
27e1e22d
JK
3494 if (!r && subdir_cb)
3495 r = subdir_cb(subdir_nr, path->buf, data);
3496
27e1e22d
JK
3497 return r;
3498}
3499
e6f875e0 3500int for_each_loose_file_in_objdir_buf(struct strbuf *path,
27e1e22d
JK
3501 each_loose_object_fn obj_cb,
3502 each_loose_cruft_fn cruft_cb,
3503 each_loose_subdir_fn subdir_cb,
3504 void *data)
3505{
e6f875e0 3506 size_t baselen = path->len;
27e1e22d
JK
3507 int r = 0;
3508 int i;
3509
27e1e22d 3510 for (i = 0; i < 256; i++) {
e6f875e0
JK
3511 strbuf_addf(path, "/%02x", i);
3512 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
27e1e22d 3513 subdir_cb, data);
e6f875e0 3514 strbuf_setlen(path, baselen);
27e1e22d
JK
3515 if (r)
3516 break;
3517 }
3518
e6f875e0
JK
3519 return r;
3520}
3521
3522int for_each_loose_file_in_objdir(const char *path,
3523 each_loose_object_fn obj_cb,
3524 each_loose_cruft_fn cruft_cb,
3525 each_loose_subdir_fn subdir_cb,
3526 void *data)
3527{
3528 struct strbuf buf = STRBUF_INIT;
3529 int r;
3530
3531 strbuf_addstr(&buf, path);