strbuf: introduce strbuf_getline_{lf,nul}()
[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;
5bdf0a84
HW
256 int pfxlen, entlen;
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
276 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
277 ent = xmalloc(sizeof(*ent) + entlen);
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 }
539e7506 304 if (!strcmp_icase(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
8f309aeb 399 while (strbuf_getline_lf(&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
c74faea1
NP
894/*
895 * This is used by git-repack in case a newly created pack happens to
896 * contain the same set of objects as an existing one. In that case
897 * the resulting file might be different even if its name would be the
898 * same. It is best to close any reference to the old pack before it is
01689909 899 * replaced on disk. Of course no index pointers or windows for given pack
c74faea1
NP
900 * must subsist at this point. If ever objects from this pack are requested
901 * again, the new version of the pack will be reinitialized through
902 * reprepare_packed_git().
903 */
904void free_pack_by_name(const char *pack_name)
905{
906 struct packed_git *p, **pp = &packed_git;
907
908 while (*pp) {
909 p = *pp;
910 if (strcmp(pack_name, p->pack_name) == 0) {
fa3a0c94 911 clear_delta_base_cache();
38849a81 912 close_pack(p);
c74faea1
NP
913 free(p->bad_object_sha1);
914 *pp = p->next;
c01f51cc
NTND
915 if (last_found_pack == p)
916 last_found_pack = NULL;
c74faea1
NP
917 free(p);
918 return;
919 }
920 pp = &p->next;
921 }
922}
923
a0788266
JS
924static unsigned int get_max_fd_limit(void)
925{
926#ifdef RLIMIT_NOFILE
491a8dec
JH
927 {
928 struct rlimit lim;
a0788266 929
491a8dec
JH
930 if (!getrlimit(RLIMIT_NOFILE, &lim))
931 return lim.rlim_cur;
932 }
933#endif
934
935#ifdef _SC_OPEN_MAX
936 {
937 long open_max = sysconf(_SC_OPEN_MAX);
938 if (0 < open_max)
939 return open_max;
940 /*
941 * Otherwise, we got -1 for one of the two
942 * reasons:
943 *
944 * (1) sysconf() did not understand _SC_OPEN_MAX
945 * and signaled an error with -1; or
946 * (2) sysconf() said there is no limit.
947 *
948 * We _could_ clear errno before calling sysconf() to
949 * tell these two cases apart and return a huge number
950 * in the latter case to let the caller cap it to a
951 * value that is not so selfish, but letting the
952 * fallback OPEN_MAX codepath take care of these cases
953 * is a lot simpler.
954 */
955 }
956#endif
a0788266 957
491a8dec 958#ifdef OPEN_MAX
a0788266
JS
959 return OPEN_MAX;
960#else
961 return 1; /* see the caller ;-) */
962#endif
963}
964
3cf8b462
SP
965/*
966 * Do not call this directly as this leaks p->pack_fd on error return;
967 * call open_packed_git() instead.
968 */
969static int open_packed_git_1(struct packed_git *p)
1f688557 970{
9bc879c1
SP
971 struct stat st;
972 struct pack_header hdr;
973 unsigned char sha1[20];
974 unsigned char *idx_sha1;
2c039da8 975 long fd_flag;
9bc879c1 976
d079837e
SP
977 if (!p->index_data && open_pack_index(p))
978 return error("packfile %s index unavailable", p->pack_name);
979
c7934306 980 if (!pack_max_fds) {
a0788266 981 unsigned int max_fds = get_max_fd_limit();
c7934306
SP
982
983 /* Save 3 for stdin/stdout/stderr, 22 for work */
984 if (25 < max_fds)
985 pack_max_fds = max_fds - 25;
986 else
987 pack_max_fds = 1;
988 }
989
88d0db55 990 while (pack_max_fds <= pack_open_fds && close_one_pack())
c7934306
SP
991 ; /* nothing */
992
f4e51683 993 p->pack_fd = git_open_noatime(p->pack_name);
9bc879c1 994 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 995 return -1;
c7934306 996 pack_open_fds++;
9bc879c1
SP
997
998 /* If we created the struct before we had the pack we lack size. */
bf592c50 999 if (!p->pack_size) {
bf592c50 1000 if (!S_ISREG(st.st_mode))
072db278 1001 return error("packfile %s not a regular file", p->pack_name);
bf592c50 1002 p->pack_size = st.st_size;
9bc879c1 1003 } else if (p->pack_size != st.st_size)
072db278 1004 return error("packfile %s size changed", p->pack_name);
9bc879c1 1005
2c039da8
JH
1006 /* We leave these file descriptors open with sliding mmap;
1007 * there is no point keeping them open across exec(), though.
1008 */
1009 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
1010 if (fd_flag < 0)
072db278 1011 return error("cannot determine file descriptor flags");
2c039da8
JH
1012 fd_flag |= FD_CLOEXEC;
1013 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 1014 return error("cannot set FD_CLOEXEC");
2c039da8 1015
9bc879c1 1016 /* Verify we recognize this pack file format. */
e6e2bd62 1017 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 1018 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 1019 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 1020 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 1021 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
1022 return error("packfile %s is version %"PRIu32" and not"
1023 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
1024 p->pack_name, ntohl(hdr.hdr_version));
1025
1026 /* Verify the pack matches its index. */
57059091 1027 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
1028 return error("packfile %s claims to have %"PRIu32" objects"
1029 " while index indicates %"PRIu32" objects",
57059091
NP
1030 p->pack_name, ntohl(hdr.hdr_entries),
1031 p->num_objects);
9bc879c1 1032 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 1033 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 1034 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 1035 return error("packfile %s signature is unavailable", p->pack_name);
42873078 1036 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 1037 if (hashcmp(sha1, idx_sha1))
072db278
SP
1038 return error("packfile %s does not match index", p->pack_name);
1039 return 0;
9bc879c1
SP
1040}
1041
3cf8b462
SP
1042static int open_packed_git(struct packed_git *p)
1043{
1044 if (!open_packed_git_1(p))
1045 return 0;
71fe5d7f 1046 close_pack_fd(p);
3cf8b462
SP
1047 return -1;
1048}
1049
c4001d92 1050static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
1051{
1052 /* We must promise at least 20 bytes (one hash) after the
1053 * offset is available from this window, otherwise the offset
1054 * is not actually in this window and a different window (which
1055 * has that one hash excess) must be used. This is to support
1056 * the object header and delta base parsing routines below.
1057 */
1058 off_t win_off = win->offset;
1059 return win_off <= offset
1060 && (offset + 20) <= (win_off + win->len);
1061}
1062
4b25d091 1063unsigned char *use_pack(struct packed_git *p,
03e79c88 1064 struct pack_window **w_cursor,
c4001d92 1065 off_t offset,
ef49a7a0 1066 unsigned long *left)
9bc879c1 1067{
60bb8b14 1068 struct pack_window *win = *w_cursor;
03e79c88 1069
a9d98a14 1070 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
1071 * pointless to ask for an offset into the middle of that
1072 * hash, and the in_window function above wouldn't match
1073 * don't allow an offset too close to the end of the file.
1074 */
d131b7af
SP
1075 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1076 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
1077 if (offset > (p->pack_size - 20))
1078 die("offset beyond end of packfile (truncated pack?)");
1079
1080 if (!win || !in_window(win, offset)) {
1081 if (win)
1082 win->inuse_cnt--;
1083 for (win = p->windows; win; win = win->next) {
1084 if (in_window(win, offset))
1085 break;
1086 }
1087 if (!win) {
78a28df9 1088 size_t window_align = packed_git_window_size / 2;
dc49cd76 1089 off_t len;
d131b7af
SP
1090
1091 if (p->pack_fd == -1 && open_packed_git(p))
1092 die("packfile %s cannot be accessed", p->pack_name);
1093
60bb8b14 1094 win = xcalloc(1, sizeof(*win));
78a28df9 1095 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
1096 len = p->pack_size - win->offset;
1097 if (len > packed_git_window_size)
1098 len = packed_git_window_size;
1099 win->len = (size_t)len;
60bb8b14 1100 pack_mapped += win->len;
11daf39b 1101 while (packed_git_limit < pack_mapped
7c3ecb32 1102 && unuse_one_window(p))
60bb8b14 1103 ; /* nothing */
c4712e45 1104 win->base = xmmap(NULL, win->len,
60bb8b14
SP
1105 PROT_READ, MAP_PRIVATE,
1106 p->pack_fd, win->offset);
1107 if (win->base == MAP_FAILED)
73b4e4be
SP
1108 die("packfile %s cannot be mapped: %s",
1109 p->pack_name,
1110 strerror(errno));
d131b7af 1111 if (!win->offset && win->len == p->pack_size
71fe5d7f
JS
1112 && !p->do_not_close)
1113 close_pack_fd(p);
a53128b6
SP
1114 pack_mmap_calls++;
1115 pack_open_windows++;
1116 if (pack_mapped > peak_pack_mapped)
1117 peak_pack_mapped = pack_mapped;
1118 if (pack_open_windows > peak_pack_open_windows)
1119 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
1120 win->next = p->windows;
1121 p->windows = win;
1122 }
1f688557 1123 }
03e79c88
SP
1124 if (win != *w_cursor) {
1125 win->last_used = pack_used_ctr++;
1126 win->inuse_cnt++;
1127 *w_cursor = win;
1128 }
60bb8b14 1129 offset -= win->offset;
03e79c88 1130 if (left)
dc49cd76 1131 *left = win->len - xsize_t(offset);
03e79c88 1132 return win->base + offset;
1f688557
JH
1133}
1134
27d69a46
NP
1135static struct packed_git *alloc_packed_git(int extra)
1136{
1137 struct packed_git *p = xmalloc(sizeof(*p) + extra);
1138 memset(p, 0, sizeof(*p));
1139 p->pack_fd = -1;
1140 return p;
1141}
1142
e0500293
JN
1143static void try_to_free_pack_memory(size_t size)
1144{
7c3ecb32 1145 release_pack_memory(size);
e0500293
JN
1146}
1147
48bcc1c3 1148struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
1f688557 1149{
e0500293 1150 static int have_set_try_to_free_routine;
1f688557 1151 struct stat st;
48bcc1c3
JK
1152 size_t alloc;
1153 struct packed_git *p;
1f688557 1154
e0500293
JN
1155 if (!have_set_try_to_free_routine) {
1156 have_set_try_to_free_routine = 1;
1157 set_try_to_free_routine(try_to_free_pack_memory);
1158 }
1159
42873078
NP
1160 /*
1161 * Make sure a corresponding .pack file exists and that
1162 * the index looks sane.
1163 */
48bcc1c3 1164 if (!strip_suffix_mem(path, &path_len, ".idx"))
1f688557 1165 return NULL;
48bcc1c3
JK
1166
1167 /*
1168 * ".pack" is long enough to hold any suffix we're adding (and
1169 * the use xsnprintf double-checks that)
1170 */
1171 alloc = path_len + strlen(".pack") + 1;
1172 p = alloc_packed_git(alloc);
42873078 1173 memcpy(p->pack_name, path, path_len);
8d25931d 1174
48bcc1c3 1175 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
8d25931d
BC
1176 if (!access(p->pack_name, F_OK))
1177 p->pack_keep = 1;
1178
48bcc1c3 1179 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
d079837e 1180 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 1181 free(p);
1f688557
JH
1182 return NULL;
1183 }
42873078 1184
1f688557
JH
1185 /* ok, it looks sane as far as we can check without
1186 * actually mapping the pack file.
1187 */
1f688557 1188 p->pack_size = st.st_size;
9d835df2 1189 p->pack_local = local;
b867092f 1190 p->mtime = st.st_mtime;
42873078
NP
1191 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1192 hashclr(p->sha1);
1f688557
JH
1193 return p;
1194}
1195
7b64469a 1196struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 1197{
42873078 1198 const char *path = sha1_pack_name(sha1);
c7ab0ba3
JK
1199 int alloc = strlen(path) + 1;
1200 struct packed_git *p = alloc_packed_git(alloc);
bf592c50 1201
c7ab0ba3 1202 memcpy(p->pack_name, path, alloc); /* includes NUL */
27d69a46 1203 hashcpy(p->sha1, sha1);
42873078
NP
1204 if (check_packed_git_idx(idx_path, p)) {
1205 free(p);
bf592c50 1206 return NULL;
42873078 1207 }
bf592c50 1208
bf592c50
DB
1209 return p;
1210}
1211
1212void install_packed_git(struct packed_git *pack)
1213{
c7934306
SP
1214 if (pack->pack_fd != -1)
1215 pack_open_fds++;
1216
bf592c50
DB
1217 pack->next = packed_git;
1218 packed_git = pack;
1219}
1220
0a489b06 1221void (*report_garbage)(unsigned seen_bits, const char *path);
543c5caa
NTND
1222
1223static void report_helper(const struct string_list *list,
1224 int seen_bits, int first, int last)
1225{
0a489b06 1226 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
543c5caa 1227 return;
0a489b06 1228
543c5caa 1229 for (; first < last; first++)
0a489b06 1230 report_garbage(seen_bits, list->items[first].string);
543c5caa
NTND
1231}
1232
1233static void report_pack_garbage(struct string_list *list)
1234{
1235 int i, baselen = -1, first = 0, seen_bits = 0;
1236
1237 if (!report_garbage)
1238 return;
1239
3383e199 1240 string_list_sort(list);
543c5caa
NTND
1241
1242 for (i = 0; i < list->nr; i++) {
1243 const char *path = list->items[i].string;
1244 if (baselen != -1 &&
1245 strncmp(path, list->items[first].string, baselen)) {
1246 report_helper(list, seen_bits, first, i);
1247 baselen = -1;
1248 seen_bits = 0;
1249 }
1250 if (baselen == -1) {
1251 const char *dot = strrchr(path, '.');
1252 if (!dot) {
0a489b06 1253 report_garbage(PACKDIR_FILE_GARBAGE, path);
543c5caa
NTND
1254 continue;
1255 }
1256 baselen = dot - path + 1;
1257 first = i;
1258 }
1259 if (!strcmp(path + baselen, "pack"))
1260 seen_bits |= 1;
1261 else if (!strcmp(path + baselen, "idx"))
1262 seen_bits |= 2;
1263 }
1264 report_helper(list, seen_bits, first, list->nr);
1265}
1266
9d835df2 1267static void prepare_packed_git_one(char *objdir, int local)
1f688557 1268{
880fb8de
RS
1269 struct strbuf path = STRBUF_INIT;
1270 size_t dirnamelen;
1f688557
JH
1271 DIR *dir;
1272 struct dirent *de;
543c5caa 1273 struct string_list garbage = STRING_LIST_INIT_DUP;
1f688557 1274
880fb8de
RS
1275 strbuf_addstr(&path, objdir);
1276 strbuf_addstr(&path, "/pack");
1277 dir = opendir(path.buf);
b5b16990 1278 if (!dir) {
26125f6b 1279 if (errno != ENOENT)
bd2afde8 1280 error("unable to open object pack directory: %s: %s",
880fb8de
RS
1281 path.buf, strerror(errno));
1282 strbuf_release(&path);
1f688557 1283 return;
b5b16990 1284 }
880fb8de
RS
1285 strbuf_addch(&path, '/');
1286 dirnamelen = path.len;
1f688557 1287 while ((de = readdir(dir)) != NULL) {
1f688557 1288 struct packed_git *p;
47bf4b0f 1289 size_t base_len;
543c5caa
NTND
1290
1291 if (is_dot_or_dotdot(de->d_name))
9cb18f56
JM
1292 continue;
1293
880fb8de
RS
1294 strbuf_setlen(&path, dirnamelen);
1295 strbuf_addstr(&path, de->d_name);
d90906a9 1296
47bf4b0f
JK
1297 base_len = path.len;
1298 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
d90906a9
NTND
1299 /* Don't reopen a pack we already have. */
1300 for (p = packed_git; p; p = p->next) {
47bf4b0f
JK
1301 size_t len;
1302 if (strip_suffix(p->pack_name, ".pack", &len) &&
1303 len == base_len &&
1304 !memcmp(p->pack_name, path.buf, len))
d90906a9
NTND
1305 break;
1306 }
1307 if (p == NULL &&
1308 /*
1309 * See if it really is a valid .idx file with
1310 * corresponding .pack file that we can map.
1311 */
880fb8de 1312 (p = add_packed_git(path.buf, path.len, local)) != NULL)
d90906a9 1313 install_packed_git(p);
86f7780c 1314 }
543c5caa
NTND
1315
1316 if (!report_garbage)
1317 continue;
1318
2975c770
JK
1319 if (ends_with(de->d_name, ".idx") ||
1320 ends_with(de->d_name, ".pack") ||
1321 ends_with(de->d_name, ".bitmap") ||
1322 ends_with(de->d_name, ".keep"))
880fb8de 1323 string_list_append(&garbage, path.buf);
543c5caa 1324 else
0a489b06 1325 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
1f688557 1326 }
5b35bcd5 1327 closedir(dir);
543c5caa
NTND
1328 report_pack_garbage(&garbage);
1329 string_list_clear(&garbage, 0);
880fb8de 1330 strbuf_release(&path);
1f688557
JH
1331}
1332
b867092f
JH
1333static int sort_pack(const void *a_, const void *b_)
1334{
1335 struct packed_git *a = *((struct packed_git **)a_);
1336 struct packed_git *b = *((struct packed_git **)b_);
1337 int st;
1338
1339 /*
1340 * Local packs tend to contain objects specific to our
1341 * variant of the project than remote ones. In addition,
1342 * remote ones could be on a network mounted filesystem.
1343 * Favor local ones for these reasons.
1344 */
1345 st = a->pack_local - b->pack_local;
1346 if (st)
1347 return -st;
1348
1349 /*
1350 * Younger packs tend to contain more recent objects,
1351 * and more recent objects tend to get accessed more
1352 * often.
1353 */
1354 if (a->mtime < b->mtime)
1355 return 1;
1356 else if (a->mtime == b->mtime)
1357 return 0;
1358 return -1;
1359}
1360
1361static void rearrange_packed_git(void)
1362{
1363 struct packed_git **ary, *p;
1364 int i, n;
1365
1366 for (n = 0, p = packed_git; p; p = p->next)
1367 n++;
1368 if (n < 2)
1369 return;
1370
1371 /* prepare an array of packed_git for easier sorting */
1372 ary = xcalloc(n, sizeof(struct packed_git *));
1373 for (n = 0, p = packed_git; p; p = p->next)
1374 ary[n++] = p;
1375
1376 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1377
1378 /* link them back again */
1379 for (i = 0; i < n - 1; i++)
1380 ary[i]->next = ary[i + 1];
1381 ary[n - 1]->next = NULL;
1382 packed_git = ary[0];
1383
1384 free(ary);
1385}
1386
637cdd9d 1387static int prepare_packed_git_run_once = 0;
9a217f2a 1388void prepare_packed_git(void)
1f688557 1389{
d5a63b99 1390 struct alternate_object_database *alt;
1f688557 1391
637cdd9d 1392 if (prepare_packed_git_run_once)
1f688557 1393 return;
9d835df2 1394 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1395 prepare_alt_odb();
d5a63b99 1396 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 1397 alt->name[-1] = 0;
9d835df2 1398 prepare_packed_git_one(alt->base, 0);
1494e038 1399 alt->name[-1] = '/';
1f688557 1400 }
b867092f 1401 rearrange_packed_git();
637cdd9d
JK
1402 prepare_packed_git_run_once = 1;
1403}
1404
fc04c412 1405void reprepare_packed_git(void)
637cdd9d
JK
1406{
1407 prepare_packed_git_run_once = 0;
1408 prepare_packed_git();
1f688557
JH
1409}
1410
8eca0b47
NP
1411static void mark_bad_packed_object(struct packed_git *p,
1412 const unsigned char *sha1)
1413{
1414 unsigned i;
1415 for (i = 0; i < p->num_bad_objects; i++)
1416 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1417 return;
1418 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1419 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1420 p->num_bad_objects++;
1421}
1422
b6c4cecc 1423static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1424{
1425 struct packed_git *p;
1426 unsigned i;
1427
1428 for (p = packed_git; p; p = p->next)
1429 for (i = 0; i < p->num_bad_objects; i++)
1430 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1431 return p;
1432 return NULL;
ac939109
NP
1433}
1434
090ea126
NTND
1435/*
1436 * With an in-core object data in "map", rehash it to make sure the
1437 * object name actually matches "sha1" to detect object corruption.
1438 * With "map" == NULL, try reading the object named with "sha1" using
1439 * the streaming interface and rehash it to do the same.
1440 */
1441int check_sha1_signature(const unsigned char *sha1, void *map,
1442 unsigned long size, const char *type)
0fcfd160
LT
1443{
1444 unsigned char real_sha1[20];
090ea126
NTND
1445 enum object_type obj_type;
1446 struct git_istream *st;
1447 git_SHA_CTX c;
1448 char hdr[32];
1449 int hdrlen;
1450
1451 if (map) {
1452 hash_sha1_file(map, size, type, real_sha1);
1453 return hashcmp(sha1, real_sha1) ? -1 : 0;
1454 }
1455
1456 st = open_istream(sha1, &obj_type, &size, NULL);
1457 if (!st)
1458 return -1;
1459
1460 /* Generate the header */
ef1286d3 1461 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(obj_type), size) + 1;
090ea126
NTND
1462
1463 /* Sha1.. */
1464 git_SHA1_Init(&c);
1465 git_SHA1_Update(&c, hdr, hdrlen);
1466 for (;;) {
1467 char buf[1024 * 16];
1468 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1469
f54fac53
JK
1470 if (readlen < 0) {
1471 close_istream(st);
1472 return -1;
1473 }
090ea126
NTND
1474 if (!readlen)
1475 break;
1476 git_SHA1_Update(&c, buf, readlen);
1477 }
1478 git_SHA1_Final(real_sha1, &c);
1479 close_istream(st);
a89fccd2 1480 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1481}
1482
ec73f580 1483int git_open_noatime(const char *name)
44d1c19e
LT
1484{
1485 static int sha1_file_open_flag = O_NOATIME;
44d1c19e 1486
f2e872aa 1487 for (;;) {
dff6f280
CB
1488 int fd;
1489
1490 errno = 0;
1491 fd = open(name, O_RDONLY | sha1_file_open_flag);
44d1c19e 1492 if (fd >= 0)
f2e872aa
SP
1493 return fd;
1494
f2e872aa
SP
1495 /* Might the failure be due to O_NOATIME? */
1496 if (errno != ENOENT && sha1_file_open_flag) {
44d1c19e 1497 sha1_file_open_flag = 0;
f2e872aa
SP
1498 continue;
1499 }
1500
1501 return -1;
44d1c19e 1502 }
44d1c19e
LT
1503}
1504
052fe5ea
JK
1505static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1506{
052fe5ea
JK
1507 struct alternate_object_database *alt;
1508
30d6c6ea 1509 if (!lstat(sha1_file_name(sha1), st))
052fe5ea
JK
1510 return 0;
1511
1512 prepare_alt_odb();
1513 errno = ENOENT;
1514 for (alt = alt_odb_list; alt; alt = alt->next) {
30d6c6ea 1515 fill_sha1_path(alt->name, sha1);
052fe5ea
JK
1516 if (!lstat(alt->base, st))
1517 return 0;
1518 }
1519
1520 return -1;
1521}
1522
44d1c19e
LT
1523static int open_sha1_file(const unsigned char *sha1)
1524{
1525 int fd;
44d1c19e 1526 struct alternate_object_database *alt;
d6c8a05b 1527 int most_interesting_errno;
44d1c19e 1528
30d6c6ea 1529 fd = git_open_noatime(sha1_file_name(sha1));
44d1c19e
LT
1530 if (fd >= 0)
1531 return fd;
d6c8a05b 1532 most_interesting_errno = errno;
44d1c19e
LT
1533
1534 prepare_alt_odb();
44d1c19e 1535 for (alt = alt_odb_list; alt; alt = alt->next) {
30d6c6ea 1536 fill_sha1_path(alt->name, sha1);
f4e51683 1537 fd = git_open_noatime(alt->base);
44d1c19e
LT
1538 if (fd >= 0)
1539 return fd;
d6c8a05b
JK
1540 if (most_interesting_errno == ENOENT)
1541 most_interesting_errno = errno;
44d1c19e 1542 }
d6c8a05b 1543 errno = most_interesting_errno;
44d1c19e
LT
1544 return -1;
1545}
1546
f0270efd 1547void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1548{
0fcfd160 1549 void *map;
144bde78 1550 int fd;
ace1534d 1551
44d1c19e
LT
1552 fd = open_sha1_file(sha1);
1553 map = NULL;
1554 if (fd >= 0) {
1555 struct stat st;
0fcfd160 1556
44d1c19e
LT
1557 if (!fstat(fd, &st)) {
1558 *size = xsize_t(st.st_size);
33e42de0
MM
1559 if (!*size) {
1560 /* mmap() is forbidden on empty files */
1561 error("object file %s is empty", sha1_file_name(sha1));
1562 return NULL;
1563 }
44d1c19e 1564 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1565 }
44d1c19e 1566 close(fd);
0fcfd160 1567 }
0fcfd160
LT
1568 return map;
1569}
1570
09ded04b
NP
1571unsigned long unpack_object_header_buffer(const unsigned char *buf,
1572 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1573{
ad1ed5ee 1574 unsigned shift;
48fb7deb 1575 unsigned long size, c;
ad1ed5ee
JH
1576 unsigned long used = 0;
1577
1578 c = buf[used++];
1579 *type = (c >> 4) & 7;
1580 size = c & 15;
1581 shift = 4;
1582 while (c & 0x80) {
f630cfda 1583 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1584 error("bad object header");
ea4f9685
JH
1585 size = used = 0;
1586 break;
09ded04b 1587 }
ad1ed5ee
JH
1588 c = buf[used++];
1589 size += (c & 0x7f) << shift;
1590 shift += 7;
1591 }
1592 *sizep = size;
1593 return used;
1594}
1595
eb4f4076 1596int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
ad1ed5ee 1597{
c4483576
LT
1598 /* Get the data stream */
1599 memset(stream, 0, sizeof(*stream));
1600 stream->next_in = map;
1601 stream->avail_in = mapsize;
1602 stream->next_out = buffer;
93821bd9
LT
1603 stream->avail_out = bufsiz;
1604
39c68542 1605 git_inflate_init(stream);
cc5c54e7 1606 return git_inflate(stream, 0);
c4483576
LT
1607}
1608
46f03448
KN
1609static int unpack_sha1_header_to_strbuf(git_zstream *stream, unsigned char *map,
1610 unsigned long mapsize, void *buffer,
1611 unsigned long bufsiz, struct strbuf *header)
1612{
1613 int status;
1614
1615 status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
1616
1617 /*
1618 * Check if entire header is unpacked in the first iteration.
1619 */
1620 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1621 return 0;
1622
1623 /*
1624 * buffer[0..bufsiz] was not large enough. Copy the partial
1625 * result out to header, and then append the result of further
1626 * reading the stream.
1627 */
1628 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1629 stream->next_out = buffer;
1630 stream->avail_out = bufsiz;
1631
1632 do {
1633 status = git_inflate(stream, 0);
1634 strbuf_add(header, buffer, stream->next_out - (unsigned char *)buffer);
1635 if (memchr(buffer, '\0', stream->next_out - (unsigned char *)buffer))
1636 return 0;
1637 stream->next_out = buffer;
1638 stream->avail_out = bufsiz;
1639 } while (status != Z_STREAM_END);
1640 return -1;
1641}
1642
ef49a7a0 1643static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1644{
1645 int bytes = strlen(buffer) + 1;
3aee68aa 1646 unsigned char *buf = xmallocz(size);
93821bd9 1647 unsigned long n;
7efbff75 1648 int status = Z_OK;
5180cacc 1649
93821bd9
LT
1650 n = stream->total_out - bytes;
1651 if (n > size)
1652 n = size;
1653 memcpy(buf, (char *) buffer + bytes, n);
1654 bytes = n;
456cdf6e
LT
1655 if (bytes <= size) {
1656 /*
1657 * The above condition must be (bytes <= size), not
1658 * (bytes < size). In other words, even though we
ccf5ace0 1659 * expect no more output and set avail_out to zero,
456cdf6e
LT
1660 * the input zlib stream may have bytes that express
1661 * "this concludes the stream", and we *do* want to
1662 * eat that input.
1663 *
1664 * Otherwise we would not be able to test that we
1665 * consumed all the input to reach the expected size;
1666 * we also want to check that zlib tells us that all
1667 * went well with status == Z_STREAM_END at the end.
1668 */
5180cacc
LT
1669 stream->next_out = buf + bytes;
1670 stream->avail_out = size - bytes;
7efbff75 1671 while (status == Z_OK)
39c68542 1672 status = git_inflate(stream, Z_FINISH);
5180cacc 1673 }
456cdf6e 1674 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1675 git_inflate_end(stream);
7efbff75
JH
1676 return buf;
1677 }
1678
1679 if (status < 0)
1680 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1681 else if (stream->avail_in)
1682 error("garbage at end of loose object '%s'",
1683 sha1_to_hex(sha1));
1684 free(buf);
1685 return NULL;
5180cacc
LT
1686}
1687
1688/*
1689 * We used to just use "sscanf()", but that's actually way
1690 * too permissive for what we want to check. So do an anal
1691 * object header parse by hand.
1692 */
46f03448
KN
1693static int parse_sha1_header_extended(const char *hdr, struct object_info *oi,
1694 unsigned int flags)
5180cacc 1695{
46f03448 1696 const char *type_buf = hdr;
5180cacc 1697 unsigned long size;
46f03448 1698 int type, type_len = 0;
5180cacc
LT
1699
1700 /*
46f03448 1701 * The type can be of any size but is followed by
21666f1a 1702 * a space.
5180cacc 1703 */
5180cacc
LT
1704 for (;;) {
1705 char c = *hdr++;
1706 if (c == ' ')
1707 break;
46f03448 1708 type_len++;
5180cacc 1709 }
46f03448
KN
1710
1711 type = type_from_string_gently(type_buf, type_len, 1);
1712 if (oi->typename)
1713 strbuf_add(oi->typename, type_buf, type_len);
1714 /*
1715 * Set type to 0 if its an unknown object and
1716 * we're obtaining the type using '--allow-unkown-type'
1717 * option.
1718 */
1719 if ((flags & LOOKUP_UNKNOWN_OBJECT) && (type < 0))
1720 type = 0;
1721 else if (type < 0)
1722 die("invalid object type");
1723 if (oi->typep)
1724 *oi->typep = type;
5180cacc
LT
1725
1726 /*
1727 * The length must follow immediately, and be in canonical
1728 * decimal format (ie "010" is not valid).
1729 */
1730 size = *hdr++ - '0';
1731 if (size > 9)
1732 return -1;
1733 if (size) {
1734 for (;;) {
1735 unsigned long c = *hdr - '0';
1736 if (c > 9)
1737 break;
1738 hdr++;
1739 size = size * 10 + c;
1740 }
1741 }
46f03448
KN
1742
1743 if (oi->sizep)
1744 *oi->sizep = size;
5180cacc
LT
1745
1746 /*
1747 * The length must be followed by a zero byte
1748 */
46f03448
KN
1749 return *hdr ? -1 : type;
1750}
1751
1752int parse_sha1_header(const char *hdr, unsigned long *sizep)
1753{
1754 struct object_info oi;
1755
1756 oi.sizep = sizep;
1757 oi.typename = NULL;
1758 oi.typep = NULL;
1759 return parse_sha1_header_extended(hdr, &oi, LOOKUP_REPLACE_OBJECT);
5180cacc
LT
1760}
1761
7efbff75 1762static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1763{
5180cacc 1764 int ret;
ef49a7a0 1765 git_zstream stream;
5180cacc 1766 char hdr[8192];
0fcfd160 1767
5180cacc 1768 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1769 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1770 return NULL;
1771
7efbff75 1772 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1773}
1774
54dab52a
NP
1775unsigned long get_size_from_delta(struct packed_git *p,
1776 struct pack_window **w_curs,
1777 off_t curpos)
1778{
1779 const unsigned char *data;
1780 unsigned char delta_head[20], *in;
ef49a7a0 1781 git_zstream stream;
54dab52a
NP
1782 int st;
1783
1784 memset(&stream, 0, sizeof(stream));
1785 stream.next_out = delta_head;
1786 stream.avail_out = sizeof(delta_head);
1787
39c68542 1788 git_inflate_init(&stream);
54dab52a
NP
1789 do {
1790 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1791 stream.next_in = in;
39c68542 1792 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1793 curpos += stream.next_in - in;
1794 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1795 stream.total_out < sizeof(delta_head));
39c68542 1796 git_inflate_end(&stream);
3d77d877
NP
1797 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1798 error("delta data unpack-initial failed");
1799 return 0;
1800 }
54dab52a
NP
1801
1802 /* Examine the initial part of the delta to figure out
1803 * the result size.
1804 */
1805 data = delta_head;
1806
1807 /* ignore base size */
1808 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1809
1810 /* Read the result size */
1811 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1812}
1813
c4001d92 1814static off_t get_delta_base(struct packed_git *p,
03e79c88 1815 struct pack_window **w_curs,
c4001d92 1816 off_t *curpos,
21666f1a 1817 enum object_type type,
c4001d92 1818 off_t delta_obj_offset)
eb32d236 1819{
2b87c45b 1820 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1821 off_t base_offset;
eb32d236 1822
8d8a4ea5
SP
1823 /* use_pack() assured us we have [base_info, base_info + 20)
1824 * as a range that we can look at without walking off the
1825 * end of the mapped window. Its actually the hash size
1826 * that is assured. An OFS_DELTA longer than the hash size
1827 * is stupid, as then a REF_DELTA would be smaller to store.
1828 */
21666f1a 1829 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1830 unsigned used = 0;
1831 unsigned char c = base_info[used++];
1832 base_offset = c & 127;
1833 while (c & 128) {
1834 base_offset += 1;
8723f216 1835 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1836 return 0; /* overflow */
eb32d236
NP
1837 c = base_info[used++];
1838 base_offset = (base_offset << 7) + (c & 127);
1839 }
1840 base_offset = delta_obj_offset - base_offset;
d8f32556 1841 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 1842 return 0; /* out of bound */
2b87c45b 1843 *curpos += used;
21666f1a 1844 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1845 /* The base entry _must_ be in the same pack */
1846 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1847 *curpos += 20;
eb32d236
NP
1848 } else
1849 die("I am totally screwed");
2b87c45b 1850 return base_offset;
eb32d236
NP
1851}
1852
5d642e75
JK
1853/*
1854 * Like get_delta_base above, but we return the sha1 instead of the pack
1855 * offset. This means it is cheaper for REF deltas (we do not have to do
1856 * the final object lookup), but more expensive for OFS deltas (we
1857 * have to load the revidx to convert the offset back into a sha1).
1858 */
1859static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1860 struct pack_window **w_curs,
1861 off_t curpos,
1862 enum object_type type,
1863 off_t delta_obj_offset)
1864{
1865 if (type == OBJ_REF_DELTA) {
1866 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1867 return base;
1868 } else if (type == OBJ_OFS_DELTA) {
1869 struct revindex_entry *revidx;
1870 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1871 type, delta_obj_offset);
1872
1873 if (!base_offset)
1874 return NULL;
1875
1876 revidx = find_pack_revindex(p, base_offset);
1877 if (!revidx)
1878 return NULL;
1879
1880 return nth_packed_object_sha1(p, revidx->nr);
1881 } else
1882 return NULL;
1883}
1884
f8c8abc5
JH
1885int unpack_object_header(struct packed_git *p,
1886 struct pack_window **w_curs,
1887 off_t *curpos,
1888 unsigned long *sizep)
a733cb60 1889{
03e79c88 1890 unsigned char *base;
ef49a7a0 1891 unsigned long left;
ad1ed5ee 1892 unsigned long used;
2b87c45b 1893 enum object_type type;
a733cb60 1894
8d8a4ea5 1895 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 1896 * as a range that we can look at. (Its actually the hash
3dff5379 1897 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1898 * the maximum deflated object size is 2^137, which is just
1899 * insane, so we know won't exceed what we have been given.
1900 */
2b87c45b 1901 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
1902 used = unpack_object_header_buffer(base, left, &type, sizep);
1903 if (!used) {
1904 type = OBJ_BAD;
1905 } else
1906 *curpos += used;
ad1ed5ee 1907
2b87c45b 1908 return type;
a733cb60
LT
1909}
1910
790d96c0
TR
1911static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1912{
1913 int type;
1914 struct revindex_entry *revidx;
1915 const unsigned char *sha1;
1916 revidx = find_pack_revindex(p, obj_offset);
1917 if (!revidx)
1918 return OBJ_BAD;
1919 sha1 = nth_packed_object_sha1(p, revidx->nr);
1920 mark_bad_packed_object(p, sha1);
1921 type = sha1_object_info(sha1, NULL);
1922 if (type <= OBJ_NONE)
1923 return OBJ_BAD;
1924 return type;
1925}
1926
790d96c0
TR
1927#define POI_STACK_PREALLOC 64
1928
90191d37
JK
1929static enum object_type packed_to_object_type(struct packed_git *p,
1930 off_t obj_offset,
1931 enum object_type type,
1932 struct pack_window **w_curs,
1933 off_t curpos)
1f688557 1934{
790d96c0
TR
1935 off_t small_poi_stack[POI_STACK_PREALLOC];
1936 off_t *poi_stack = small_poi_stack;
1937 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
5db47c2b 1938
790d96c0
TR
1939 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1940 off_t base_offset;
90191d37 1941 unsigned long size;
790d96c0
TR
1942 /* Push the object we're going to leave behind */
1943 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1944 poi_stack_alloc = alloc_nr(poi_stack_nr);
1945 poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
1946 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1947 } else {
1948 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1949 }
1950 poi_stack[poi_stack_nr++] = obj_offset;
1951 /* If parsing the base offset fails, just unwind */
90191d37 1952 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
790d96c0
TR
1953 if (!base_offset)
1954 goto unwind;
1955 curpos = obj_offset = base_offset;
90191d37 1956 type = unpack_object_header(p, w_curs, &curpos, &size);
790d96c0
TR
1957 if (type <= OBJ_NONE) {
1958 /* If getting the base itself fails, we first
1959 * retry the base, otherwise unwind */
1960 type = retry_bad_packed_offset(p, base_offset);
1961 if (type > OBJ_NONE)
1962 goto out;
1963 goto unwind;
1964 }
1965 }
1966
21666f1a 1967 switch (type) {
790d96c0 1968 case OBJ_BAD:
a733cb60 1969 case OBJ_COMMIT:
a733cb60 1970 case OBJ_TREE:
a733cb60 1971 case OBJ_BLOB:
a733cb60 1972 case OBJ_TAG:
a69d0943 1973 break;
1f688557 1974 default:
3d77d877
NP
1975 error("unknown object type %i at offset %"PRIuMAX" in %s",
1976 type, (uintmax_t)obj_offset, p->pack_name);
1977 type = OBJ_BAD;
1f688557 1978 }
790d96c0
TR
1979
1980out:
1981 if (poi_stack != small_poi_stack)
1982 free(poi_stack);
21666f1a 1983 return type;
790d96c0
TR
1984
1985unwind:
1986 while (poi_stack_nr) {
1987 obj_offset = poi_stack[--poi_stack_nr];
1988 type = retry_bad_packed_offset(p, obj_offset);
1989 if (type > OBJ_NONE)
1990 goto out;
1991 }
1992 type = OBJ_BAD;
1993 goto out;
1f688557
JH
1994}
1995
90191d37 1996static int packed_object_info(struct packed_git *p, off_t obj_offset,
23c339c0 1997 struct object_info *oi)
90191d37
JK
1998{
1999 struct pack_window *w_curs = NULL;
2000 unsigned long size;
2001 off_t curpos = obj_offset;
2002 enum object_type type;
2003
412916ee
JK
2004 /*
2005 * We always get the representation type, but only convert it to
2006 * a "real" type later if the caller is interested.
2007 */
90191d37
JK
2008 type = unpack_object_header(p, &w_curs, &curpos, &size);
2009
23c339c0 2010 if (oi->sizep) {
90191d37
JK
2011 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2012 off_t tmp_pos = curpos;
2013 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
2014 type, obj_offset);
2015 if (!base_offset) {
2016 type = OBJ_BAD;
2017 goto out;
2018 }
23c339c0
JK
2019 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
2020 if (*oi->sizep == 0) {
90191d37
JK
2021 type = OBJ_BAD;
2022 goto out;
2023 }
2024 } else {
23c339c0 2025 *oi->sizep = size;
90191d37
JK
2026 }
2027 }
2028
23c339c0 2029 if (oi->disk_sizep) {
90191d37 2030 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
23c339c0 2031 *oi->disk_sizep = revidx[1].offset - obj_offset;
90191d37
JK
2032 }
2033
23c339c0
JK
2034 if (oi->typep) {
2035 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
2036 if (*oi->typep < 0) {
412916ee
JK
2037 type = OBJ_BAD;
2038 goto out;
2039 }
2040 }
90191d37 2041
5d642e75
JK
2042 if (oi->delta_base_sha1) {
2043 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
2044 const unsigned char *base;
2045
2046 base = get_delta_base_sha1(p, &w_curs, curpos,
2047 type, obj_offset);
2048 if (!base) {
2049 type = OBJ_BAD;
2050 goto out;
2051 }
2052
2053 hashcpy(oi->delta_base_sha1, base);
2054 } else
2055 hashclr(oi->delta_base_sha1);
2056 }
2057
90191d37
JK
2058out:
2059 unuse_pack(&w_curs);
2060 return type;
2061}
2062
eb950c19 2063static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 2064 struct pack_window **w_curs,
c4001d92 2065 off_t curpos,
eb950c19 2066 unsigned long size)
de530aaa
SP
2067{
2068 int st;
ef49a7a0 2069 git_zstream stream;
079afb18 2070 unsigned char *buffer, *in;
de530aaa 2071
735efde8
NTND
2072 buffer = xmallocz_gently(size);
2073 if (!buffer)
2074 return NULL;
de530aaa 2075 memset(&stream, 0, sizeof(stream));
de530aaa 2076 stream.next_out = buffer;
39eea7bd 2077 stream.avail_out = size + 1;
de530aaa 2078
39c68542 2079 git_inflate_init(&stream);
079afb18 2080 do {
2b87c45b 2081 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 2082 stream.next_in = in;
39c68542 2083 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
2084 if (!stream.avail_out)
2085 break; /* the payload is larger than it should be */
2b87c45b 2086 curpos += stream.next_in - in;
079afb18 2087 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 2088 git_inflate_end(&stream);
de530aaa
SP
2089 if ((st != Z_STREAM_END) || stream.total_out != size) {
2090 free(buffer);
2091 return NULL;
2092 }
2093
2094 return buffer;
2095}
2096
e5e01619
LT
2097#define MAX_DELTA_CACHE (256)
2098
18bdec11 2099static size_t delta_base_cached;
5e08ecbf
NP
2100
2101static struct delta_base_cache_lru_list {
2102 struct delta_base_cache_lru_list *prev;
2103 struct delta_base_cache_lru_list *next;
2104} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
2105
e5e01619 2106static struct delta_base_cache_entry {
5e08ecbf
NP
2107 struct delta_base_cache_lru_list lru;
2108 void *data;
e5e01619
LT
2109 struct packed_git *p;
2110 off_t base_offset;
2111 unsigned long size;
e5e01619
LT
2112 enum object_type type;
2113} delta_base_cache[MAX_DELTA_CACHE];
2114
2115static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
2116{
2117 unsigned long hash;
2118
56a1a3ab 2119 hash = (unsigned long)(intptr_t)p + (unsigned long)base_offset;
e5e01619 2120 hash += (hash >> 8) + (hash >> 16);
3358004a 2121 return hash % MAX_DELTA_CACHE;
e5e01619
LT
2122}
2123
84dd81c1
TR
2124static struct delta_base_cache_entry *
2125get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
5266d369
JH
2126{
2127 unsigned long hash = pack_entry_hash(p, base_offset);
84dd81c1
TR
2128 return delta_base_cache + hash;
2129}
2130
2131static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
2132 struct packed_git *p, off_t base_offset)
2133{
5266d369
JH
2134 return (ent->data && ent->p == p && ent->base_offset == base_offset);
2135}
2136
84dd81c1
TR
2137static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2138{
2139 struct delta_base_cache_entry *ent;
2140 ent = get_delta_base_cache_entry(p, base_offset);
2141 return eq_delta_base_cache_entry(ent, p, base_offset);
2142}
2143
2144static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2145{
2146 ent->data = NULL;
2147 ent->lru.next->prev = ent->lru.prev;
2148 ent->lru.prev->next = ent->lru.next;
2149 delta_base_cached -= ent->size;
2150}
2151
62f255ad 2152static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 2153 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 2154{
84dd81c1 2155 struct delta_base_cache_entry *ent;
e5e01619 2156 void *ret;
e5e01619 2157
84dd81c1
TR
2158 ent = get_delta_base_cache_entry(p, base_offset);
2159
2160 if (!eq_delta_base_cache_entry(ent, p, base_offset))
749bc58c 2161 return unpack_entry(p, base_offset, type, base_size);
e5e01619 2162
84dd81c1
TR
2163 ret = ent->data;
2164
2165 if (!keep_cache)
2166 clear_delta_base_cache_entry(ent);
2167 else
182af834 2168 ret = xmemdupz(ent->data, ent->size);
e5e01619
LT
2169 *type = ent->type;
2170 *base_size = ent->size;
2171 return ret;
62f255ad
LT
2172}
2173
18bdec11
SP
2174static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2175{
2176 if (ent->data) {
2177 free(ent->data);
2178 ent->data = NULL;
5e08ecbf
NP
2179 ent->lru.next->prev = ent->lru.prev;
2180 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
2181 delta_base_cached -= ent->size;
2182 }
2183}
2184
3d20c636
SP
2185void clear_delta_base_cache(void)
2186{
2187 unsigned long p;
2188 for (p = 0; p < MAX_DELTA_CACHE; p++)
2189 release_delta_base_cache(&delta_base_cache[p]);
2190}
2191
62f255ad
LT
2192static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2193 void *base, unsigned long base_size, enum object_type type)
2194{
5e08ecbf 2195 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 2196 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 2197 struct delta_base_cache_lru_list *lru;
e5e01619 2198
18bdec11
SP
2199 release_delta_base_cache(ent);
2200 delta_base_cached += base_size;
5e08ecbf
NP
2201
2202 for (lru = delta_base_cache_lru.next;
2203 delta_base_cached > delta_base_cache_limit
2204 && lru != &delta_base_cache_lru;
2205 lru = lru->next) {
2206 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
2207 if (f->type == OBJ_BLOB)
2208 release_delta_base_cache(f);
2209 }
5e08ecbf
NP
2210 for (lru = delta_base_cache_lru.next;
2211 delta_base_cached > delta_base_cache_limit
2212 && lru != &delta_base_cache_lru;
2213 lru = lru->next) {
2214 struct delta_base_cache_entry *f = (void *)lru;
2215 release_delta_base_cache(f);
2216 }
18bdec11 2217
e5e01619
LT
2218 ent->p = p;
2219 ent->base_offset = base_offset;
2220 ent->type = type;
2221 ent->data = base;
2222 ent->size = base_size;
5e08ecbf
NP
2223 ent->lru.next = &delta_base_cache_lru;
2224 ent->lru.prev = delta_base_cache_lru.prev;
2225 delta_base_cache_lru.prev->next = &ent->lru;
2226 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
2227}
2228
c2c5b270
CC
2229static void *read_object(const unsigned char *sha1, enum object_type *type,
2230 unsigned long *size);
2231
5f44324d
JH
2232static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2233{
67dc598e
KB
2234 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2235 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2236 p->pack_name, (uintmax_t)obj_offset);
5f44324d
JH
2237}
2238
0e8189e2
NP
2239int do_check_packed_object_crc;
2240
abe601bb
TR
2241#define UNPACK_ENTRY_STACK_PREALLOC 64
2242struct unpack_entry_stack_ent {
2243 off_t obj_offset;
2244 off_t curpos;
2245 unsigned long size;
2246};
2247
c4001d92 2248void *unpack_entry(struct packed_git *p, off_t obj_offset,
abe601bb 2249 enum object_type *final_type, unsigned long *final_size)
1f688557 2250{
03e79c88 2251 struct pack_window *w_curs = NULL;
c4001d92 2252 off_t curpos = obj_offset;
abe601bb
TR
2253 void *data = NULL;
2254 unsigned long size;
2255 enum object_type type;
2256 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2257 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2258 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2259 int base_from_cache = 0;
1f688557 2260
67dc598e 2261 write_pack_access_log(p, obj_offset);
5f44324d 2262
abe601bb
TR
2263 /* PHASE 1: drill down to the innermost base object */
2264 for (;;) {
2265 off_t base_offset;
2266 int i;
2267 struct delta_base_cache_entry *ent;
2268
77965f8b
NTND
2269 ent = get_delta_base_cache_entry(p, curpos);
2270 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2271 type = ent->type;
2272 data = ent->data;
2273 size = ent->size;
2274 clear_delta_base_cache_entry(ent);
2275 base_from_cache = 1;
2276 break;
2277 }
2278
abe601bb
TR
2279 if (do_check_packed_object_crc && p->index_version > 1) {
2280 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2281 unsigned long len = revidx[1].offset - obj_offset;
2282 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2283 const unsigned char *sha1 =
2284 nth_packed_object_sha1(p, revidx->nr);
2285 error("bad packed object CRC for %s",
2286 sha1_to_hex(sha1));
2287 mark_bad_packed_object(p, sha1);
2288 unuse_pack(&w_curs);
2289 return NULL;
2290 }
2291 }
2292
abe601bb
TR
2293 type = unpack_object_header(p, &w_curs, &curpos, &size);
2294 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2295 break;
2296
2297 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2298 if (!base_offset) {
2299 error("failed to validate delta base reference "
2300 "at offset %"PRIuMAX" from %s",
2301 (uintmax_t)curpos, p->pack_name);
2302 /* bail to phase 2, in hopes of recovery */
2303 data = NULL;
2304 break;
2305 }
2306
2307 /* push object, proceed to base */
2308 if (delta_stack_nr >= delta_stack_alloc
2309 && delta_stack == small_delta_stack) {
2310 delta_stack_alloc = alloc_nr(delta_stack_nr);
2311 delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
2312 memcpy(delta_stack, small_delta_stack,
2313 sizeof(*delta_stack)*delta_stack_nr);
2314 } else {
2315 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2316 }
2317 i = delta_stack_nr++;
2318 delta_stack[i].obj_offset = obj_offset;
2319 delta_stack[i].curpos = curpos;
2320 delta_stack[i].size = size;
2321
2322 curpos = obj_offset = base_offset;
0e8189e2
NP
2323 }
2324
abe601bb
TR
2325 /* PHASE 2: handle the base */
2326 switch (type) {
eb32d236
NP
2327 case OBJ_OFS_DELTA:
2328 case OBJ_REF_DELTA:
abe601bb
TR
2329 if (data)
2330 die("BUG in unpack_entry: left loop at a valid delta");
4d703a1a 2331 break;
a733cb60 2332 case OBJ_COMMIT:
a733cb60 2333 case OBJ_TREE:
a733cb60 2334 case OBJ_BLOB:
a733cb60 2335 case OBJ_TAG:
abe601bb
TR
2336 if (!base_from_cache)
2337 data = unpack_compressed_entry(p, &w_curs, curpos, size);
4d703a1a 2338 break;
1f688557 2339 default:
8eca0b47
NP
2340 data = NULL;
2341 error("unknown object type %i at offset %"PRIuMAX" in %s",
abe601bb
TR
2342 type, (uintmax_t)obj_offset, p->pack_name);
2343 }
2344
2345 /* PHASE 3: apply deltas in order */
2346
2347 /* invariants:
2348 * 'data' holds the base data, or NULL if there was corruption
2349 */
2350 while (delta_stack_nr) {
2351 void *delta_data;
2352 void *base = data;
2353 unsigned long delta_size, base_size = size;
2354 int i;
2355
2356 data = NULL;
2357
2358 if (base)
2359 add_delta_base_cache(p, obj_offset, base, base_size, type);
2360
2361 if (!base) {
2362 /*
2363 * We're probably in deep shit, but let's try to fetch
2364 * the required base anyway from another pack or loose.
2365 * This is costly but should happen only in the presence
2366 * of a corrupted pack, and is better than failing outright.
2367 */
2368 struct revindex_entry *revidx;
2369 const unsigned char *base_sha1;
2370 revidx = find_pack_revindex(p, obj_offset);
2371 if (revidx) {
2372 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2373 error("failed to read delta base object %s"
2374 " at offset %"PRIuMAX" from %s",
2375 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2376 p->pack_name);
2377 mark_bad_packed_object(p, base_sha1);
2378 base = read_object(base_sha1, &type, &base_size);
2379 }
2380 }
2381
2382 i = --delta_stack_nr;
2383 obj_offset = delta_stack[i].obj_offset;
2384 curpos = delta_stack[i].curpos;
2385 delta_size = delta_stack[i].size;
2386
2387 if (!base)
2388 continue;
2389
2390 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2391
2392 if (!delta_data) {
2393 error("failed to unpack compressed delta "
2394 "at offset %"PRIuMAX" from %s",
2395 (uintmax_t)curpos, p->pack_name);
abe601bb
TR
2396 data = NULL;
2397 continue;
2398 }
2399
2400 data = patch_delta(base, base_size,
2401 delta_data, delta_size,
2402 &size);
1ee886c1
JK
2403
2404 /*
2405 * We could not apply the delta; warn the user, but keep going.
2406 * Our failure will be noticed either in the next iteration of
2407 * the loop, or if this is the final delta, in the caller when
2408 * we return NULL. Those code paths will take care of making
2409 * a more explicit warning and retrying with another copy of
2410 * the object.
2411 */
abe601bb 2412 if (!data)
1ee886c1 2413 error("failed to apply delta");
abe601bb 2414
4b8f772c 2415 free(delta_data);
1f688557 2416 }
abe601bb
TR
2417
2418 *final_type = type;
2419 *final_size = size;
2420
03e79c88 2421 unuse_pack(&w_curs);
019d1e65
NTND
2422
2423 if (delta_stack != small_delta_stack)
2424 free(delta_stack);
2425
21666f1a 2426 return data;
1f688557
JH
2427}
2428
d079837e 2429const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 2430 uint32_t n)
9a217f2a 2431{
42873078 2432 const unsigned char *index = p->index_data;
d079837e
SP
2433 if (!index) {
2434 if (open_pack_index(p))
2435 return NULL;
2436 index = p->index_data;
2437 }
57059091 2438 if (n >= p->num_objects)
d72308e0 2439 return NULL;
74e34e1f
NP
2440 index += 4 * 256;
2441 if (p->index_version == 1) {
2442 return index + 24 * n + 4;
2443 } else {
2444 index += 8;
2445 return index + 20 * n;
2446 }
2447}
2448
99093238 2449off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
2450{
2451 const unsigned char *index = p->index_data;
2452 index += 4 * 256;
2453 if (p->index_version == 1) {
2454 return ntohl(*((uint32_t *)(index + 24 * n)));
2455 } else {
2456 uint32_t off;
2457 index += 8 + p->num_objects * (20 + 4);
2458 off = ntohl(*((uint32_t *)(index + 4 * n)));
2459 if (!(off & 0x80000000))
2460 return off;
2461 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2462 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2463 ntohl(*((uint32_t *)(index + 4)));
2464 }
9a217f2a
JH
2465}
2466
c4001d92 2467off_t find_pack_entry_one(const unsigned char *sha1,
43057304 2468 struct packed_git *p)
1f688557 2469{
42873078 2470 const uint32_t *level1_ofs = p->index_data;
42873078 2471 const unsigned char *index = p->index_data;
628522ec
JH
2472 unsigned hi, lo, stride;
2473 static int use_lookup = -1;
2474 static int debug_lookup = -1;
2475
2476 if (debug_lookup < 0)
2477 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 2478
d079837e
SP
2479 if (!index) {
2480 if (open_pack_index(p))
2481 return 0;
2482 level1_ofs = p->index_data;
2483 index = p->index_data;
2484 }
74e34e1f
NP
2485 if (p->index_version > 1) {
2486 level1_ofs += 2;
2487 index += 8;
2488 }
42873078 2489 index += 4 * 256;
74e34e1f
NP
2490 hi = ntohl(level1_ofs[*sha1]);
2491 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2492 if (p->index_version > 1) {
2493 stride = 20;
2494 } else {
2495 stride = 24;
2496 index += 4;
2497 }
2498
2499 if (debug_lookup)
6e1c2344 2500 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2501 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2502
2503 if (use_lookup < 0)
2504 use_lookup = !!getenv("GIT_USE_LOOKUP");
2505 if (use_lookup) {
2506 int pos = sha1_entry_pos(index, stride, 0,
2507 lo, hi, p->num_objects, sha1);
2508 if (pos < 0)
2509 return 0;
2510 return nth_packed_object_offset(p, pos);
2511 }
1f688557
JH
2512
2513 do {
74e34e1f 2514 unsigned mi = (lo + hi) / 2;
628522ec
JH
2515 int cmp = hashcmp(index + mi * stride, sha1);
2516
2517 if (debug_lookup)
2518 printf("lo %u hi %u rg %u mi %u\n",
2519 lo, hi, hi - lo, mi);
43057304 2520 if (!cmp)
74e34e1f 2521 return nth_packed_object_offset(p, mi);
1f688557
JH
2522 if (cmp > 0)
2523 hi = mi;
2524 else
2525 lo = mi+1;
2526 } while (lo < hi);
2527 return 0;
2528}
2529
4c080182 2530int is_pack_valid(struct packed_git *p)
d131b7af
SP
2531{
2532 /* An already open pack is known to be valid. */
2533 if (p->pack_fd != -1)
2534 return 1;
2535
2536 /* If the pack has one window completely covering the
2537 * file size, the pack is known to be valid even if
2538 * the descriptor is not currently open.
2539 */
2540 if (p->windows) {
2541 struct pack_window *w = p->windows;
2542
2543 if (!w->offset && w->len == p->pack_size)
2544 return 1;
2545 }
2546
2547 /* Force the pack to open to prove its valid. */
2548 return !open_packed_git(p);
2549}
2550
95099731
NTND
2551static int fill_pack_entry(const unsigned char *sha1,
2552 struct pack_entry *e,
2553 struct packed_git *p)
2554{
2555 off_t offset;
2556
2557 if (p->num_bad_objects) {
2558 unsigned i;
2559 for (i = 0; i < p->num_bad_objects; i++)
2560 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2561 return 0;
2562 }
2563
2564 offset = find_pack_entry_one(sha1, p);
2565 if (!offset)
2566 return 0;
2567
2568 /*
2569 * We are about to tell the caller where they can locate the
2570 * requested object. We better make sure the packfile is
2571 * still here and can be accessed before supplying that
2572 * answer, as it may have been deleted since the index was
2573 * loaded!
2574 */
319b678a 2575 if (!is_pack_valid(p))
95099731 2576 return 0;
95099731
NTND
2577 e->offset = offset;
2578 e->p = p;
2579 hashcpy(e->sha1, sha1);
2580 return 1;
2581}
2582
d40d535b
MH
2583/*
2584 * Iff a pack file contains the object named by sha1, return true and
2585 * store its location to e.
2586 */
4d6acb70 2587static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557
JH
2588{
2589 struct packed_git *p;
43057304 2590
1f688557 2591 prepare_packed_git();
f7c22cc6
NP
2592 if (!packed_git)
2593 return 0;
1f688557 2594
c01f51cc
NTND
2595 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2596 return 1;
8eca0b47 2597
c01f51cc 2598 for (p = packed_git; p; p = p->next) {
1b1005d1
MH
2599 if (p == last_found_pack)
2600 continue; /* we already checked this one */
f7c22cc6 2601
1b1005d1
MH
2602 if (fill_pack_entry(sha1, e, p)) {
2603 last_found_pack = p;
2604 return 1;
2605 }
c01f51cc 2606 }
1f688557
JH
2607 return 0;
2608}
2609
a6080a0a 2610struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2611 struct packed_git *packs)
2612{
2613 struct packed_git *p;
bf592c50
DB
2614
2615 for (p = packs; p; p = p->next) {
43057304 2616 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2617 return p;
2618 }
2619 return NULL;
21666f1a 2620
bf592c50
DB
2621}
2622
052fe5ea 2623static int sha1_loose_object_info(const unsigned char *sha1,
46f03448
KN
2624 struct object_info *oi,
2625 int flags)
65c2e0c3 2626{
46f03448
KN
2627 int status = 0;
2628 unsigned long mapsize;
65c2e0c3 2629 void *map;
ef49a7a0 2630 git_zstream stream;
d65a16f6 2631 char hdr[32];
46f03448 2632 struct strbuf hdrbuf = STRBUF_INIT;
65c2e0c3 2633
5d642e75
JK
2634 if (oi->delta_base_sha1)
2635 hashclr(oi->delta_base_sha1);
2636
052fe5ea
JK
2637 /*
2638 * If we don't care about type or size, then we don't
4ef8d1dd
JH
2639 * need to look inside the object at all. Note that we
2640 * do not optimize out the stat call, even if the
2641 * caller doesn't care about the disk-size, since our
2642 * return value implicitly indicates whether the
2643 * object even exists.
052fe5ea 2644 */
46f03448 2645 if (!oi->typep && !oi->typename && !oi->sizep) {
4ef8d1dd
JH
2646 struct stat st;
2647 if (stat_sha1_file(sha1, &st) < 0)
2648 return -1;
2649 if (oi->disk_sizep)
23c339c0 2650 *oi->disk_sizep = st.st_size;
052fe5ea
JK
2651 return 0;
2652 }
2653
bb6b8e4f 2654 map = map_sha1_file(sha1, &mapsize);
f0df4ed5 2655 if (!map)
dbea72a8 2656 return -1;
23c339c0
JK
2657 if (oi->disk_sizep)
2658 *oi->disk_sizep = mapsize;
46f03448
KN
2659 if ((flags & LOOKUP_UNKNOWN_OBJECT)) {
2660 if (unpack_sha1_header_to_strbuf(&stream, map, mapsize, hdr, sizeof(hdr), &hdrbuf) < 0)
2661 status = error("unable to unpack %s header with --allow-unknown-type",
2662 sha1_to_hex(sha1));
2663 } else if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
36e4d74a
JH
2664 status = error("unable to unpack %s header",
2665 sha1_to_hex(sha1));
46f03448
KN
2666 if (status < 0)
2667 ; /* Do nothing */
2668 else if (hdrbuf.len) {
2669 if ((status = parse_sha1_header_extended(hdrbuf.buf, oi, flags)) < 0)
2670 status = error("unable to parse %s header with --allow-unknown-type",
2671 sha1_to_hex(sha1));
2672 } else if ((status = parse_sha1_header_extended(hdr, oi, flags)) < 0)
36e4d74a 2673 status = error("unable to parse %s header", sha1_to_hex(sha1));
39c68542 2674 git_inflate_end(&stream);
65c2e0c3 2675 munmap(map, mapsize);
46f03448 2676 if (status && oi->typep)
23c339c0 2677 *oi->typep = status;
46f03448 2678 strbuf_release(&hdrbuf);
052fe5ea 2679 return 0;
65c2e0c3
JH
2680}
2681
de7b5d62 2682int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
f0df4ed5 2683{
c4d9986f 2684 struct cached_object *co;
f0df4ed5 2685 struct pack_entry e;
5b086407 2686 int rtype;
46f03448 2687 enum object_type real_type;
1f7117ef 2688 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
f0df4ed5 2689
1f7117ef 2690 co = find_cached_object(real);
c4d9986f 2691 if (co) {
5b086407
JK
2692 if (oi->typep)
2693 *(oi->typep) = co->type;
9a490590
JH
2694 if (oi->sizep)
2695 *(oi->sizep) = co->size;
161f00e7
JK
2696 if (oi->disk_sizep)
2697 *(oi->disk_sizep) = 0;
5d642e75
JK
2698 if (oi->delta_base_sha1)
2699 hashclr(oi->delta_base_sha1);
46f03448
KN
2700 if (oi->typename)
2701 strbuf_addstr(oi->typename, typename(co->type));
9a490590 2702 oi->whence = OI_CACHED;
5b086407 2703 return 0;
c4d9986f
NTND
2704 }
2705
1f7117ef 2706 if (!find_pack_entry(real, &e)) {
ddd63e64 2707 /* Most likely it's a loose object. */
46f03448 2708 if (!sha1_loose_object_info(real, oi, flags)) {
9a490590 2709 oi->whence = OI_LOOSE;
5b086407 2710 return 0;
9a490590 2711 }
ddd63e64
SG
2712
2713 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 2714 reprepare_packed_git();
1f7117ef 2715 if (!find_pack_entry(real, &e))
052fe5ea 2716 return -1;
f0df4ed5 2717 }
3d77d877 2718
46f03448
KN
2719 /*
2720 * packed_object_info() does not follow the delta chain to
2721 * find out the real type, unless it is given oi->typep.
2722 */
2723 if (oi->typename && !oi->typep)
2724 oi->typep = &real_type;
2725
23c339c0 2726 rtype = packed_object_info(e.p, e.offset, oi);
412916ee 2727 if (rtype < 0) {
1f7117ef 2728 mark_bad_packed_object(e.p, real);
46f03448
KN
2729 if (oi->typep == &real_type)
2730 oi->typep = NULL;
1f7117ef 2731 return sha1_object_info_extended(real, oi, 0);
5266d369
JH
2732 } else if (in_delta_base_cache(e.p, e.offset)) {
2733 oi->whence = OI_DBCACHED;
9a490590
JH
2734 } else {
2735 oi->whence = OI_PACKED;
2736 oi->u.packed.offset = e.offset;
2737 oi->u.packed.pack = e.p;
2738 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2739 rtype == OBJ_OFS_DELTA);
3d77d877 2740 }
46f03448
KN
2741 if (oi->typename)
2742 strbuf_addstr(oi->typename, typename(*oi->typep));
2743 if (oi->typep == &real_type)
2744 oi->typep = NULL;
3d77d877 2745
5b086407 2746 return 0;
f0df4ed5
JS
2747}
2748
3fc0dca9 2749/* returns enum object_type or negative */
9a490590
JH
2750int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2751{
5b086407 2752 enum object_type type;
d099b717 2753 struct object_info oi = {NULL};
9a490590 2754
5b086407 2755 oi.typep = &type;
9a490590 2756 oi.sizep = sizep;
de7b5d62 2757 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
5b086407
JK
2758 return -1;
2759 return type;
9a490590
JH
2760}
2761
21666f1a
NP
2762static void *read_packed_sha1(const unsigned char *sha1,
2763 enum object_type *type, unsigned long *size)
1f688557
JH
2764{
2765 struct pack_entry e;
8eca0b47 2766 void *data;
1f688557 2767
cd673c1f 2768 if (!find_pack_entry(sha1, &e))
1f688557 2769 return NULL;
8eca0b47
NP
2770 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2771 if (!data) {
2772 /*
2773 * We're probably in deep shit, but let's try to fetch
2774 * the required object anyway from another pack or loose.
2775 * This should happen only in the presence of a corrupted
2776 * pack, and is better than failing outright.
2777 */
2778 error("failed to read object %s at offset %"PRIuMAX" from %s",
2779 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2780 mark_bad_packed_object(e.p, sha1);
ac939109 2781 data = read_object(sha1, type, size);
8eca0b47
NP
2782 }
2783 return data;
1f688557
JH
2784}
2785
21666f1a
NP
2786int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2787 unsigned char *sha1)
d66b37bb
JH
2788{
2789 struct cached_object *co;
2790
21666f1a 2791 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2792 if (has_sha1_file(sha1) || find_cached_object(sha1))
2793 return 0;
c7353967 2794 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
d66b37bb
JH
2795 co = &cached_objects[cached_object_nr++];
2796 co->size = len;
21666f1a 2797 co->type = type;
efa13f7b
JH
2798 co->buf = xmalloc(len);
2799 memcpy(co->buf, buf, len);
d66b37bb
JH
2800 hashcpy(co->sha1, sha1);
2801 return 0;
2802}
2803
c2c5b270
CC
2804static void *read_object(const unsigned char *sha1, enum object_type *type,
2805 unsigned long *size)
0fcfd160
LT
2806{
2807 unsigned long mapsize;
2808 void *map, *buf;
d66b37bb
JH
2809 struct cached_object *co;
2810
2811 co = find_cached_object(sha1);
2812 if (co) {
21666f1a 2813 *type = co->type;
d66b37bb 2814 *size = co->size;
182af834 2815 return xmemdupz(co->buf, co->size);
d66b37bb 2816 }
0fcfd160 2817
8276c007
PE
2818 buf = read_packed_sha1(sha1, type, size);
2819 if (buf)
2820 return buf;
bb6b8e4f 2821 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2822 if (map) {
7efbff75 2823 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2824 munmap(map, mapsize);
2825 return buf;
2826 }
637cdd9d 2827 reprepare_packed_git();
8276c007 2828 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2829}
2830
b6c4cecc
JH
2831/*
2832 * This function dies on corrupt objects; the callers who want to
2833 * deal with them should arrange to call read_object() and give error
2834 * messages themselves.
2835 */
5bf29b95
JH
2836void *read_sha1_file_extended(const unsigned char *sha1,
2837 enum object_type *type,
2838 unsigned long *size,
2839 unsigned flag)
ac939109 2840{
3ba7a065 2841 void *data;
b6c4cecc 2842 const struct packed_git *p;
bf93eea0 2843 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
b6c4cecc 2844
3ba7a065
JH
2845 errno = 0;
2846 data = read_object(repl, type, size);
4bbf5a26 2847 if (data)
b6c4cecc 2848 return data;
68095570 2849
25f3af3f 2850 if (errno && errno != ENOENT)
3ba7a065
JH
2851 die_errno("failed to read object %s", sha1_to_hex(sha1));
2852
68095570 2853 /* die if we replaced an object with one that does not exist */
b6c4cecc 2854 if (repl != sha1)
68095570
CC
2855 die("replacement %s not found for %s",
2856 sha1_to_hex(repl), sha1_to_hex(sha1));
2857
b6c4cecc 2858 if (has_loose_object(repl)) {
30d6c6ea
MH
2859 const char *path = sha1_file_name(sha1);
2860
b6c4cecc
JH
2861 die("loose object %s (stored in %s) is corrupt",
2862 sha1_to_hex(repl), path);
e8b15e61 2863 }
68095570 2864
b6c4cecc
JH
2865 if ((p = has_packed_and_bad(repl)) != NULL)
2866 die("packed object %s (stored in %s) is corrupt",
2867 sha1_to_hex(repl), p->pack_name);
f5552aee 2868
b6c4cecc 2869 return NULL;
ac939109
NP
2870}
2871
40469ee9 2872void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2873 const char *required_type_name,
40469ee9
JH
2874 unsigned long *size,
2875 unsigned char *actual_sha1_return)
f4913f91 2876{
21666f1a 2877 enum object_type type, required_type;
f4913f91
JH
2878 void *buffer;
2879 unsigned long isize;
40469ee9 2880 unsigned char actual_sha1[20];
f4913f91 2881
21666f1a 2882 required_type = type_from_string(required_type_name);
e702496e 2883 hashcpy(actual_sha1, sha1);
40469ee9
JH
2884 while (1) {
2885 int ref_length = -1;
2886 const char *ref_type = NULL;
f4913f91 2887
21666f1a 2888 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2889 if (!buffer)
2890 return NULL;
21666f1a 2891 if (type == required_type) {
40469ee9
JH
2892 *size = isize;
2893 if (actual_sha1_return)
e702496e 2894 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2895 return buffer;
2896 }
2897 /* Handle references */
21666f1a 2898 else if (type == OBJ_COMMIT)
40469ee9 2899 ref_type = "tree ";
21666f1a 2900 else if (type == OBJ_TAG)
40469ee9
JH
2901 ref_type = "object ";
2902 else {
2903 free(buffer);
2904 return NULL;
2905 }
2906 ref_length = strlen(ref_type);
f4913f91 2907
50974ec9
MK
2908 if (ref_length + 40 > isize ||
2909 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2910 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2911 free(buffer);
2912 return NULL;
2913 }
1cf58e72 2914 free(buffer);
40469ee9
JH
2915 /* Now we have the ID of the referred-to object in
2916 * actual_sha1. Check again. */
f4913f91 2917 }
f4913f91
JH
2918}
2919
ce9fbf16 2920static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2921 const char *type, unsigned char *sha1,
d65a16f6 2922 char *hdr, int *hdrlen)
d410c0f5 2923{
9126f009 2924 git_SHA_CTX c;
d410c0f5
JH
2925
2926 /* Generate the header */
ef1286d3 2927 *hdrlen = xsnprintf(hdr, *hdrlen, "%s %lu", type, len)+1;
d410c0f5
JH
2928
2929 /* Sha1.. */
9126f009
NP
2930 git_SHA1_Init(&c);
2931 git_SHA1_Update(&c, hdr, *hdrlen);
2932 git_SHA1_Update(&c, buf, len);
2933 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2934}
2935
230f1322 2936/*
5a688fe4 2937 * Move the just written object into its final resting place.
230f1322 2938 */
cb5add58 2939int finalize_object_file(const char *tmpfile, const char *filename)
230f1322 2940{
e32c0a9c 2941 int ret = 0;
5a688fe4 2942
348df166 2943 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
2944 goto try_rename;
2945 else if (link(tmpfile, filename))
e32c0a9c 2946 ret = errno;
7ebb6fca
LT
2947
2948 /*
2949 * Coda hack - coda doesn't like cross-directory links,
2950 * so we fall back to a rename, which will mean that it
2951 * won't be able to check collisions, but that's not a
2952 * big deal.
2953 *
2954 * The same holds for FAT formatted media.
2955 *
3be1f18e 2956 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
2957 * left to unlink.
2958 */
2959 if (ret && ret != EEXIST) {
be66a6c4 2960 try_rename:
7ebb6fca 2961 if (!rename(tmpfile, filename))
3be1f18e 2962 goto out;
9e48b389 2963 ret = errno;
230f1322 2964 }
691f1a28 2965 unlink_or_warn(tmpfile);
230f1322
LT
2966 if (ret) {
2967 if (ret != EEXIST) {
82247e9b 2968 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
230f1322
LT
2969 }
2970 /* FIXME!!! Collision check here ? */
2971 }
2972
3be1f18e 2973out:
5256b006 2974 if (adjust_shared_perm(filename))
5a688fe4 2975 return error("unable to set permission to '%s'", filename);
230f1322
LT
2976 return 0;
2977}
2978
4d548150
LT
2979static int write_buffer(int fd, const void *buf, size_t len)
2980{
d34cf19b 2981 if (write_in_full(fd, buf, len) < 0)
93822c22 2982 return error("file write error (%s)", strerror(errno));
4d548150
LT
2983 return 0;
2984}
2985
ce9fbf16 2986int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2987 unsigned char *sha1)
2988{
d65a16f6 2989 char hdr[32];
ef1286d3 2990 int hdrlen = sizeof(hdr);
abdc3fc8
RS
2991 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2992 return 0;
2993}
2994
e9039dd3
LT
2995/* Finalize a file on disk, and close it. */
2996static void close_sha1_file(int fd)
2997{
aafe9fba
LT
2998 if (fsync_object_files)
2999 fsync_or_die(fd, "sha1 file");
e9039dd3 3000 if (close(fd) != 0)
d824cbba 3001 die_errno("error when closing sha1 file");
e9039dd3
LT
3002}
3003
5723fe7e
LT
3004/* Size of directory component, including the ending '/' */
3005static inline int directory_size(const char *filename)
3006{
3007 const char *s = strrchr(filename, '/');
3008 if (!s)
3009 return 0;
3010 return s - filename + 1;
3011}
3012
3013/*
3014 * This creates a temporary file in the same directory as the final
3015 * 'filename'
3016 *
3017 * We want to avoid cross-directory filename renames, because those
3018 * can have problems on various filesystems (FAT, NFS, Coda).
3019 */
d4b3d11a 3020static int create_tmpfile(struct strbuf *tmp, const char *filename)
5723fe7e
LT
3021{
3022 int fd, dirlen = directory_size(filename);
3023
d4b3d11a
JK
3024 strbuf_reset(tmp);
3025 strbuf_add(tmp, filename, dirlen);
3026 strbuf_addstr(tmp, "tmp_obj_XXXXXX");
3027 fd = git_mkstemp_mode(tmp->buf, 0444);
cbacbf4e 3028 if (fd < 0 && dirlen && errno == ENOENT) {
d4b3d11a
JK
3029 /*
3030 * Make sure the directory exists; note that the contents
3031 * of the buffer are undefined after mkstemp returns an
3032 * error, so we have to rewrite the whole buffer from
3033 * scratch.
3034 */
3035 strbuf_reset(tmp);
3036 strbuf_add(tmp, filename, dirlen - 1);
3037 if (mkdir(tmp->buf, 0777) && errno != EEXIST)
b2476a60 3038 return -1;
d4b3d11a 3039 if (adjust_shared_perm(tmp->buf))
5723fe7e
LT
3040 return -1;
3041
3042 /* Try again */
d4b3d11a
JK
3043 strbuf_addstr(tmp, "/tmp_obj_XXXXXX");
3044 fd = git_mkstemp_mode(tmp->buf, 0444);
5723fe7e
LT
3045 }
3046 return fd;
3047}
3048
bbac7311 3049static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 3050 const void *buf, unsigned long len, time_t mtime)
0fcfd160 3051{
915308b1 3052 int fd, ret;
9892beba 3053 unsigned char compressed[4096];
ef49a7a0 3054 git_zstream stream;
748af44c
NP
3055 git_SHA_CTX c;
3056 unsigned char parano_sha1[20];
d4b3d11a 3057 static struct strbuf tmp_file = STRBUF_INIT;
30d6c6ea 3058 const char *filename = sha1_file_name(sha1);
a44c9a5e 3059
d4b3d11a 3060 fd = create_tmpfile(&tmp_file, filename);
aac17941 3061 if (fd < 0) {
35243577 3062 if (errno == EACCES)
82247e9b 3063 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 3064 else
5eaeda70 3065 return error("unable to create temporary file: %s", strerror(errno));
aac17941
LT
3066 }
3067
0fcfd160 3068 /* Set it up */
55bb5c91 3069 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 3070 stream.next_out = compressed;
9892beba 3071 stream.avail_out = sizeof(compressed);
748af44c 3072 git_SHA1_Init(&c);
a44c9a5e
LT
3073
3074 /* First header.. */
d65a16f6 3075 stream.next_in = (unsigned char *)hdr;
a44c9a5e 3076 stream.avail_in = hdrlen;
55bb5c91
JH
3077 while (git_deflate(&stream, 0) == Z_OK)
3078 ; /* nothing */
748af44c 3079 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
3080
3081 /* Then the data itself.. */
c00e657d 3082 stream.next_in = (void *)buf;
a44c9a5e 3083 stream.avail_in = len;
9892beba 3084 do {
748af44c 3085 unsigned char *in0 = stream.next_in;
55bb5c91 3086 ret = git_deflate(&stream, Z_FINISH);
748af44c 3087 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
3088 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
3089 die("unable to write sha1 file");
3090 stream.next_out = compressed;
3091 stream.avail_out = sizeof(compressed);
3092 } while (ret == Z_OK);
3093
ac54c277
LT
3094 if (ret != Z_STREAM_END)
3095 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 3096 ret = git_deflate_end_gently(&stream);
ac54c277
LT
3097 if (ret != Z_OK)
3098 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
3099 git_SHA1_Final(parano_sha1, &c);
3100 if (hashcmp(sha1, parano_sha1) != 0)
3101 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 3102
e9039dd3 3103 close_sha1_file(fd);
0fcfd160 3104
bbac7311
NP
3105 if (mtime) {
3106 struct utimbuf utb;
3107 utb.actime = mtime;
3108 utb.modtime = mtime;
d4b3d11a 3109 if (utime(tmp_file.buf, &utb) < 0)
bbac7311 3110 warning("failed utime() on %s: %s",
d4b3d11a 3111 tmp_file.buf, strerror(errno));
bbac7311
NP
3112 }
3113
d4b3d11a 3114 return finalize_object_file(tmp_file.buf, filename);
0fcfd160 3115}
8237b185 3116
33d4221c
JK
3117static int freshen_loose_object(const unsigned char *sha1)
3118{
3119 return check_and_freshen(sha1, 1);
3120}
3121
3122static int freshen_packed_object(const unsigned char *sha1)
3123{
3124 struct pack_entry e;
ee1c6c34
JK
3125 if (!find_pack_entry(sha1, &e))
3126 return 0;
3127 if (e.p->freshened)
3128 return 1;
3129 if (!freshen_file(e.p->pack_name))
3130 return 0;
3131 e.p->freshened = 1;
3132 return 1;
33d4221c
JK
3133}
3134
1427a7ff 3135int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1)
bbac7311 3136{
bbac7311 3137 char hdr[32];
ef1286d3 3138 int hdrlen = sizeof(hdr);
bbac7311
NP
3139
3140 /* Normally if we have it in the pack then we do not bother writing
3141 * it out into .git/objects/??/?{38} file.
3142 */
3143 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
b5f52f37 3144 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
bbac7311
NP
3145 return 0;
3146 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3147}
3148
0c3db67c
ES
3149int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
3150 unsigned char *sha1, unsigned flags)
3151{
3152 char *header;
3153 int hdrlen, status = 0;
3154
3155 /* type string, SP, %lu of the length plus NUL must fit this */
ef1286d3
JK
3156 hdrlen = strlen(type) + 32;
3157 header = xmalloc(hdrlen);
0c3db67c
ES
3158 write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
3159
3160 if (!(flags & HASH_WRITE_OBJECT))
3161 goto cleanup;
051086b9 3162 if (freshen_packed_object(sha1) || freshen_loose_object(sha1))
0c3db67c
ES
3163 goto cleanup;
3164 status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
3165
3166cleanup:
3167 free(header);
3168 return status;
3169}
3170
bbac7311
NP
3171int force_object_loose(const unsigned char *sha1, time_t mtime)
3172{
bbac7311
NP
3173 void *buf;
3174 unsigned long len;
3175 enum object_type type;
3176 char hdr[32];
3177 int hdrlen;
1fb23e65 3178 int ret;
bbac7311 3179
c529d75a 3180 if (has_loose_object(sha1))
bbac7311
NP
3181 return 0;
3182 buf = read_packed_sha1(sha1, &type, &len);
3183 if (!buf)
3184 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
ef1286d3 3185 hdrlen = xsnprintf(hdr, sizeof(hdr), "%s %lu", typename(type), len) + 1;
1fb23e65
BS
3186 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3187 free(buf);
3188
3189 return ret;
bbac7311
NP
3190}
3191
bf592c50
DB
3192int has_pack_index(const unsigned char *sha1)
3193{
3194 struct stat st;
3195 if (stat(sha1_pack_index_name(sha1), &st))
3196 return 0;
3197 return 1;
bf592c50
DB
3198}
3199
cd673c1f
JH
3200int has_sha1_pack(const unsigned char *sha1)
3201{
3202 struct pack_entry e;
3203 return find_pack_entry(sha1, &e);
3204}
3205
0eeb077b 3206int has_sha1_file_with_flags(const unsigned char *sha1, int flags)
8237b185 3207{
1f688557
JH
3208 struct pack_entry e;
3209
cd673c1f 3210 if (find_pack_entry(sha1, &e))
1f688557 3211 return 1;
45e8a748
JK
3212 if (has_loose_object(sha1))
3213 return 1;
0eeb077b
JK
3214 if (flags & HAS_SHA1_QUICK)
3215 return 0;
45e8a748
JK
3216 reprepare_packed_git();
3217 return find_pack_entry(sha1, &e);
b419aa25 3218}
3219
3220int has_object_file(const struct object_id *oid)
3221{
3222 return has_sha1_file(oid->hash);
8237b185 3223}
74400e71 3224
c879daa2
NTND
3225static void check_tree(const void *buf, size_t size)
3226{
3227 struct tree_desc desc;
3228 struct name_entry entry;
3229
3230 init_tree_desc(&desc, buf, size);
3231 while (tree_entry(&desc, &entry))
3232 /* do nothing
3233 * tree_entry() will die() on malformed entries */
3234 ;
3235}
3236
3237static void check_commit(const void *buf, size_t size)
3238{
3239 struct commit c;
3240 memset(&c, 0, sizeof(c));
3241 if (parse_commit_buffer(&c, buf, size))
3242 die("corrupt commit");
3243}
3244
3245static void check_tag(const void *buf, size_t size)
3246{
3247 struct tag t;
3248 memset(&t, 0, sizeof(t));
3249 if (parse_tag_buffer(&t, buf, size))
3250 die("corrupt tag");
3251}
3252
43df4f86 3253static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
3254 enum object_type type,
3255 const char *path, unsigned flags)
e7332f96 3256{
6c510bee 3257 int ret, re_allocated = 0;
c4ce46fc 3258 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 3259
7672db20 3260 if (!type)
edaec3fb 3261 type = OBJ_BLOB;
6c510bee
LT
3262
3263 /*
3264 * Convert blobs to git internal format
3265 */
43df4f86 3266 if ((type == OBJ_BLOB) && path) {
f285a2d7 3267 struct strbuf nbuf = STRBUF_INIT;
21e5ad50 3268 if (convert_to_git(path, buf, size, &nbuf,
5e12e78e 3269 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 3270 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
3271 re_allocated = 1;
3272 }
3273 }
c4ce46fc 3274 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
3275 if (type == OBJ_TREE)
3276 check_tree(buf, size);
3277 if (type == OBJ_COMMIT)
3278 check_commit(buf, size);
3279 if (type == OBJ_TAG)
3280 check_tag(buf, size);
3281 }
6c510bee 3282
7672db20 3283 if (write_object)
edaec3fb 3284 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 3285 else
edaec3fb 3286 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 3287 if (re_allocated)
6c510bee 3288 free(buf);
43df4f86
DP
3289 return ret;
3290}
3291
9035d75a
SP
3292static int index_stream_convert_blob(unsigned char *sha1, int fd,
3293 const char *path, unsigned flags)
3294{
3295 int ret;
3296 const int write_object = flags & HASH_WRITE_OBJECT;
3297 struct strbuf sbuf = STRBUF_INIT;
3298
3299 assert(path);
3300 assert(would_convert_to_git_filter_fd(path));
3301
3302 convert_to_git_filter_fd(path, fd, &sbuf,
3303 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3304
3305 if (write_object)
3306 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3307 sha1);
3308 else
3309 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3310 sha1);
3311 strbuf_release(&sbuf);
3312 return ret;
3313}
3314
7b41e1e1
JH
3315static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3316 const char *path, unsigned flags)
3317{
3318 struct strbuf sbuf = STRBUF_INIT;
3319 int ret;
3320
3321 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3322 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3323 else
3324 ret = -1;
3325 strbuf_release(&sbuf);
3326 return ret;
3327}
3328
ea68b0ce
DP
3329#define SMALL_FILE_SIZE (32*1024)
3330
7b41e1e1
JH
3331static int index_core(unsigned char *sha1, int fd, size_t size,
3332 enum object_type type, const char *path,
3333 unsigned flags)
43df4f86
DP
3334{
3335 int ret;
43df4f86 3336
7b41e1e1 3337 if (!size) {
f6a1e1e2 3338 ret = index_mem(sha1, "", size, type, path, flags);
ea68b0ce
DP
3339 } else if (size <= SMALL_FILE_SIZE) {
3340 char *buf = xmalloc(size);
3341 if (size == read_in_full(fd, buf, size))
c4ce46fc 3342 ret = index_mem(sha1, buf, size, type, path, flags);
ea68b0ce
DP
3343 else
3344 ret = error("short read %s", strerror(errno));
3345 free(buf);
08bda208 3346 } else {
43df4f86 3347 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
c4ce46fc 3348 ret = index_mem(sha1, buf, size, type, path, flags);
aac17941 3349 munmap(buf, size);
08bda208 3350 }
7b41e1e1
JH
3351 return ret;
3352}
3353
4dd1fbc7 3354/*
568508e7
JH
3355 * This creates one packfile per large blob unless bulk-checkin
3356 * machinery is "plugged".
4dd1fbc7
JH
3357 *
3358 * This also bypasses the usual "convert-to-git" dance, and that is on
3359 * purpose. We could write a streaming version of the converting
3360 * functions and insert that before feeding the data to fast-import
4f22b101
JK
3361 * (or equivalent in-core API described above). However, that is
3362 * somewhat complicated, as we do not know the size of the filter
3363 * result, which we need to know beforehand when writing a git object.
3364 * Since the primary motivation for trying to stream from the working
3365 * tree file and to avoid mmaping it in core is to deal with large
3366 * binary blobs, they generally do not want to get any conversion, and
3367 * callers should avoid this code path when filters are requested.
4dd1fbc7
JH
3368 */
3369static int index_stream(unsigned char *sha1, int fd, size_t size,
3370 enum object_type type, const char *path,
3371 unsigned flags)
3372{
568508e7 3373 return index_bulk_checkin(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
3374}
3375
7b41e1e1
JH
3376int index_fd(unsigned char *sha1, int fd, struct stat *st,
3377 enum object_type type, const char *path, unsigned flags)
3378{
3379 int ret;
7b41e1e1 3380
9079ab7c
SP
3381 /*
3382 * Call xsize_t() only when needed to avoid potentially unnecessary
3383 * die() for large files.
3384 */
9035d75a
SP
3385 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3386 ret = index_stream_convert_blob(sha1, fd, path, flags);
3387 else if (!S_ISREG(st->st_mode))
7b41e1e1 3388 ret = index_pipe(sha1, fd, type, path, flags);
9079ab7c 3389 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
7ce7c760 3390 (path && would_convert_to_git(path)))
9079ab7c
SP
3391 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3392 flags);
4dd1fbc7 3393 else
9079ab7c
SP
3394 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3395 flags);
43df4f86 3396 close(fd);
aac17941 3397 return ret;
74400e71 3398}
ec1fcc16 3399
c4ce46fc 3400int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
ec1fcc16
JH
3401{
3402 int fd;
b760d3aa 3403 struct strbuf sb = STRBUF_INIT;
ec1fcc16
JH
3404
3405 switch (st->st_mode & S_IFMT) {
3406 case S_IFREG:
3407 fd = open(path, O_RDONLY);
3408 if (fd < 0)
3409 return error("open(\"%s\"): %s", path,
3410 strerror(errno));
c4ce46fc 3411 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
ec1fcc16
JH
3412 return error("%s: failed to insert into database",
3413 path);
3414 break;
3415 case S_IFLNK:
b760d3aa 3416 if (strbuf_readlink(&sb, path, st->st_size)) {
ec1fcc16 3417 char *errstr = strerror(errno);
ec1fcc16
JH
3418 return error("readlink(\"%s\"): %s", path,
3419 errstr);
3420 }
c4ce46fc 3421 if (!(flags & HASH_WRITE_OBJECT))
b760d3aa
LT
3422 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3423 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
ec1fcc16
JH
3424 return error("%s: failed to insert into database",
3425 path);
b760d3aa 3426 strbuf_release(&sb);
ec1fcc16 3427 break;
f35a6d3b
LT
3428 case S_IFDIR:
3429 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
3430 default:
3431 return error("%s: unsupported file type", path);
3432 }
3433 return 0;
3434}
a69e5429
JH
3435
3436int read_pack_header(int fd, struct pack_header *header)
3437{
c697ad14
HO
3438 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3439 /* "eof before pack header was fully read" */
3440 return PH_ERROR_EOF;
3441
a69e5429
JH
3442 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3443 /* "protocol error (pack signature mismatch detected)" */
3444 return PH_ERROR_PACK_SIGNATURE;
3445 if (!pack_version_ok(header->hdr_version))
3446 /* "protocol error (pack version unsupported)" */
3447 return PH_ERROR_PROTOCOL;
3448 return 0;
3449}
40d52ff7
JK
3450
3451void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3452{
3453 enum object_type type = sha1_object_info(sha1, NULL);
3454 if (type < 0)
3455 die("%s is not a valid object", sha1_to_hex(sha1));
3456 if (type != expect)
3457 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3458 typename(expect));
3459}
27e1e22d
JK
3460
3461static int for_each_file_in_obj_subdir(int subdir_nr,
3462 struct strbuf *path,
3463 each_loose_object_fn obj_cb,
3464 each_loose_cruft_fn cruft_cb,
3465 each_loose_subdir_fn subdir_cb,
3466 void *data)
3467{
3468 size_t baselen = path->len;
3469 DIR *dir = opendir(path->buf);
3470 struct dirent *de;
3471 int r = 0;
3472
3473 if (!dir) {
3474 if (errno == ENOENT)
3475 return 0;
3476 return error("unable to open %s: %s", path->buf, strerror(errno));
3477 }
3478
3479 while ((de = readdir(dir))) {
3480 if (is_dot_or_dotdot(de->d_name))
3481 continue;
3482
3483 strbuf_setlen(path, baselen);
3484 strbuf_addf(path, "/%s", de->d_name);
3485
3486 if (strlen(de->d_name) == 38) {
3487 char hex[41];
3488 unsigned char sha1[20];
3489
3490 snprintf(hex, sizeof(hex), "%02x%s",
3491 subdir_nr, de->d_name);
3492 if (!get_sha1_hex(hex, sha1)) {
3493 if (obj_cb) {
3494 r = obj_cb(sha1, path->buf, data);
3495 if (r)
3496 break;
3497 }
3498 continue;
3499 }
3500 }
3501
3502 if (cruft_cb) {
3503 r = cruft_cb(de->d_name, path->buf, data);
3504 if (r)
3505 break;
3506 }
3507 }
094c7e63 3508 closedir(dir);
27e1e22d 3509
094c7e63 3510 strbuf_setlen(path, baselen);
27e1e22d
JK
3511 if (!r && subdir_cb)
3512 r = subdir_cb(subdir_nr, path->buf, data);
3513
27e1e22d
JK
3514 return r;
3515}
3516
e6f875e0 3517int for_each_loose_file_in_objdir_buf(struct strbuf *path,
27e1e22d
JK
3518 each_loose_object_fn obj_cb,
3519 each_loose_cruft_fn cruft_cb,
3520 each_loose_subdir_fn subdir_cb,
3521 void *data)
3522{
e6f875e0 3523 size_t baselen = path->len;
27e1e22d
JK
3524 int r = 0;
3525 int i;
3526
27e1e22d 3527 for (i = 0; i < 256; i++) {
e6f875e0
JK
3528 strbuf_addf(path, "/%02x", i);
3529 r = for_each_file_in_obj_subdir(i, path, obj_cb, cruft_cb,
27e1e22d 3530 subdir_cb, data);
e6f875e0 3531 strbuf_setlen(path, baselen);
27e1e22d
JK
3532 if (r)
3533 break;
3534 }
3535
e6f875e0
JK
3536 return r;
3537}
3538
3539int for_each_loose_file_in_objdir(const char *path,
3540 each_loose_object_fn obj_cb,
3541 each_loose_cruft_fn cruft_cb,
3542 each_loose_subdir_fn subdir_cb,
3543 void *data)
3544{
3545 struct strbuf buf = STRBUF_INIT;
3546 int r;
3547
3548 strbuf_addstr(&buf, path);