t6050: show that git cat-file --batch fails with replace objects
[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"
1f688557 11#include "delta.h"
a733cb60 12#include "pack.h"
8e440259
PE
13#include "blob.h"
14#include "commit.h"
4dd1fbc7 15#include "run-command.h"
8e440259
PE
16#include "tag.h"
17#include "tree.h"
c879daa2 18#include "tree-walk.h"
f35a6d3b 19#include "refs.h"
70f5d5d3 20#include "pack-revindex.h"
628522ec 21#include "sha1-lookup.h"
568508e7 22#include "bulk-checkin.h"
090ea126 23#include "streaming.h"
543c5caa 24#include "dir.h"
0fcfd160 25
144bde78
LT
26#ifndef O_NOATIME
27#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
28#define O_NOATIME 01000000
29#else
30#define O_NOATIME 0
31#endif
32#endif
33
28bd70d8
JN
34#define SZ_FMT PRIuMAX
35static inline uintmax_t sz_fmt(size_t s) { return s; }
e05db0fd 36
96f1e58f 37const unsigned char null_sha1[20];
88cd621d 38
b12ca963
NTND
39static const char *no_log_pack_access = "no_log_pack_access";
40static const char *log_pack_access;
41
c597ba80
NTND
42/*
43 * This is meant to hold a *small* number of objects that you would
44 * want read_sha1_file() to be able to return, but yet you do not want
45 * to write them into the object store (e.g. a browse-only
46 * application).
47 */
48static struct cached_object {
49 unsigned char sha1[20];
50 enum object_type type;
51 void *buf;
52 unsigned long size;
53} *cached_objects;
54static int cached_object_nr, cached_object_alloc;
55
56static struct cached_object empty_tree = {
dab0d410 57 EMPTY_TREE_SHA1_BIN_LITERAL,
c597ba80
NTND
58 OBJ_TREE,
59 "",
60 0
61};
62
c01f51cc
NTND
63static struct packed_git *last_found_pack;
64
c597ba80
NTND
65static struct cached_object *find_cached_object(const unsigned char *sha1)
66{
67 int i;
68 struct cached_object *co = cached_objects;
69
70 for (i = 0; i < cached_object_nr; i++, co++) {
71 if (!hashcmp(co->sha1, sha1))
72 return co;
73 }
74 if (!hashcmp(sha1, empty_tree.sha1))
75 return &empty_tree;
76 return NULL;
77}
78
90a6464b
JH
79int mkdir_in_gitdir(const char *path)
80{
81 if (mkdir(path, 0777)) {
82 int saved_errno = errno;
83 struct stat st;
84 struct strbuf sb = STRBUF_INIT;
85
86 if (errno != EEXIST)
87 return -1;
88 /*
89 * Are we looking at a path in a symlinked worktree
90 * whose original repository does not yet have it?
91 * e.g. .git/rr-cache pointing at its original
92 * repository in which the user hasn't performed any
93 * conflict resolution yet?
94 */
95 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
96 strbuf_readlink(&sb, path, st.st_size) ||
97 !is_absolute_path(sb.buf) ||
98 mkdir(sb.buf, 0777)) {
99 strbuf_release(&sb);
100 errno = saved_errno;
101 return -1;
102 }
103 strbuf_release(&sb);
104 }
105 return adjust_shared_perm(path);
106}
107
b2cb9425
JH
108int safe_create_leading_directories(char *path)
109{
8385abfd 110 char *pos = path + offset_1st_component(path);
67d42212
JR
111 struct stat st;
112
b2cb9425
JH
113 while (pos) {
114 pos = strchr(pos, '/');
115 if (!pos)
116 break;
5f0bdf50
JH
117 while (*++pos == '/')
118 ;
119 if (!*pos)
120 break;
121 *--pos = '\0';
67d42212
JR
122 if (!stat(path, &st)) {
123 /* path exists */
124 if (!S_ISDIR(st.st_mode)) {
b2cb9425 125 *pos = '/';
67d42212 126 return -3;
b2cb9425 127 }
457f06d6 128 }
67d42212 129 else if (mkdir(path, 0777)) {
928734d9
SW
130 if (errno == EEXIST &&
131 !stat(path, &st) && S_ISDIR(st.st_mode)) {
132 ; /* somebody created it since we checked */
133 } else {
134 *pos = '/';
135 return -1;
136 }
67d42212 137 }
457f06d6
JS
138 else if (adjust_shared_perm(path)) {
139 *pos = '/';
140 return -2;
141 }
b2cb9425
JH
142 *pos++ = '/';
143 }
144 return 0;
145}
723c31fe 146
8e21d63b
JK
147int safe_create_leading_directories_const(const char *path)
148{
149 /* path points to cache entries, so xstrdup before messing with it */
150 char *buf = xstrdup(path);
151 int result = safe_create_leading_directories(buf);
152 free(buf);
153 return result;
154}
155
ace1534d
JH
156static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
157{
158 int i;
159 for (i = 0; i < 20; i++) {
160 static char hex[] = "0123456789abcdef";
161 unsigned int val = sha1[i];
162 char *pos = pathbuf + i*2 + (i > 0);
163 *pos++ = hex[val >> 4];
164 *pos = hex[val & 0xf];
165 }
166}
167
0fcfd160
LT
168/*
169 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 170 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 171 * filename.
ace1534d
JH
172 *
173 * Also note that this returns the location for creating. Reading
174 * SHA1 file can happen from any alternate directory listed in the
d19938ab 175 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 176 * the primary object database.
0fcfd160
LT
177 */
178char *sha1_file_name(const unsigned char *sha1)
179{
560fb6a1
JK
180 static char buf[PATH_MAX];
181 const char *objdir;
182 int len;
0fcfd160 183
560fb6a1
JK
184 objdir = get_object_directory();
185 len = strlen(objdir);
186
187 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
188 if (len + 43 > PATH_MAX)
189 die("insanely long object directory %s", objdir);
190 memcpy(buf, objdir, len);
191 buf[len] = '/';
192 buf[len+3] = '/';
193 buf[len+42] = '\0';
194 fill_sha1_path(buf + len + 1, sha1);
195 return buf;
0fcfd160
LT
196}
197
633f43e1 198static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 199 char **name, char **base, const char *which)
bf592c50
DB
200{
201 static const char hex[] = "0123456789abcdef";
633f43e1 202 char *buf;
bf592c50
DB
203 int i;
204
633f43e1 205 if (!*base) {
bf592c50
DB
206 const char *sha1_file_directory = get_object_directory();
207 int len = strlen(sha1_file_directory);
633f43e1 208 *base = xmalloc(len + 60);
6eec46bd
JH
209 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
210 sha1_file_directory, which);
633f43e1 211 *name = *base + len + 11;
bf592c50
DB
212 }
213
633f43e1 214 buf = *name;
bf592c50
DB
215
216 for (i = 0; i < 20; i++) {
217 unsigned int val = *sha1++;
218 *buf++ = hex[val >> 4];
219 *buf++ = hex[val & 0xf];
220 }
a6080a0a 221
633f43e1 222 return *base;
bf592c50
DB
223}
224
633f43e1 225char *sha1_pack_name(const unsigned char *sha1)
bf592c50 226{
633f43e1 227 static char *name, *base;
bf592c50 228
6eec46bd 229 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 230}
bf592c50 231
633f43e1
HO
232char *sha1_pack_index_name(const unsigned char *sha1)
233{
234 static char *name, *base;
a6080a0a 235
6eec46bd 236 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
237}
238
d5a63b99
JH
239struct alternate_object_database *alt_odb_list;
240static struct alternate_object_database **alt_odb_tail;
ace1534d 241
f4e51683 242static int git_open_noatime(const char *name);
c2f493a4 243
ddd5d056
JH
244/*
245 * Prepare alternate object database registry.
d5a63b99
JH
246 *
247 * The variable alt_odb_list points at the list of struct
248 * alternate_object_database. The elements on this list come from
249 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
250 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
251 * whose contents is similar to that environment variable but can be
252 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
253 * contains "/the/directory/corresponding/to/.git/objects/...", while
254 * its name points just after the slash at the end of ".git/objects/"
255 * in the example above, and has enough space to hold 40-byte hex
256 * SHA1, an extra slash for the first level indirection, and the
257 * terminating NUL.
ddd5d056 258 */
6eac50d8 259static int link_alt_odb_entry(const char *entry, const char *relative_base, int depth)
ace1534d 260{
1494e038 261 const char *objdir = get_object_directory();
c2f493a4
MW
262 struct alternate_object_database *ent;
263 struct alternate_object_database *alt;
5bdf0a84
HW
264 int pfxlen, entlen;
265 struct strbuf pathbuf = STRBUF_INIT;
d5a63b99 266
85dadc38 267 if (!is_absolute_path(entry) && relative_base) {
5bdf0a84
HW
268 strbuf_addstr(&pathbuf, real_path(relative_base));
269 strbuf_addch(&pathbuf, '/');
c2f493a4 270 }
6eac50d8 271 strbuf_addstr(&pathbuf, entry);
c2f493a4 272
5bdf0a84
HW
273 normalize_path_copy(pathbuf.buf, pathbuf.buf);
274
275 pfxlen = strlen(pathbuf.buf);
276
277 /*
278 * The trailing slash after the directory name is given by
279 * this function at the end. Remove duplicates.
280 */
281 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
282 pfxlen -= 1;
283
284 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
285 ent = xmalloc(sizeof(*ent) + entlen);
286 memcpy(ent->base, pathbuf.buf, pfxlen);
287 strbuf_release(&pathbuf);
c2f493a4
MW
288
289 ent->name = ent->base + pfxlen + 1;
290 ent->base[pfxlen + 3] = '/';
291 ent->base[pfxlen] = ent->base[entlen-1] = 0;
292
293 /* Detect cases where alternate disappeared */
90b4a71c 294 if (!is_directory(ent->base)) {
c2f493a4
MW
295 error("object directory %s does not exist; "
296 "check .git/objects/info/alternates.",
297 ent->base);
298 free(ent);
299 return -1;
300 }
301
302 /* Prevent the common mistake of listing the same
303 * thing twice, or object directory itself.
304 */
305 for (alt = alt_odb_list; alt; alt = alt->next) {
306 if (!memcmp(ent->base, alt->base, pfxlen)) {
307 free(ent);
308 return -1;
309 }
310 }
cb2912c3 311 if (!strcmp(ent->base, objdir)) {
c2f493a4
MW
312 free(ent);
313 return -1;
314 }
315
316 /* add the alternate entry */
317 *alt_odb_tail = ent;
318 alt_odb_tail = &(ent->next);
319 ent->next = NULL;
320
321 /* recursively add alternates */
322 read_info_alternates(ent->base, depth + 1);
323
324 ent->base[pfxlen] = '/';
325
326 return 0;
327}
328
c5950164 329static void link_alt_odb_entries(const char *alt, int len, int sep,
c2f493a4
MW
330 const char *relative_base, int depth)
331{
6eac50d8
MH
332 struct string_list entries = STRING_LIST_INIT_NODUP;
333 char *alt_copy;
334 int i;
c2f493a4
MW
335
336 if (depth > 5) {
337 error("%s: ignoring alternate object stores, nesting too deep.",
338 relative_base);
339 return;
340 }
341
c5950164 342 alt_copy = xmemdupz(alt, len);
6eac50d8
MH
343 string_list_split_in_place(&entries, alt_copy, sep, -1);
344 for (i = 0; i < entries.nr; i++) {
345 const char *entry = entries.items[i].string;
346 if (entry[0] == '\0' || entry[0] == '#')
9577e7e3 347 continue;
6eac50d8
MH
348 if (!is_absolute_path(entry) && depth) {
349 error("%s: ignoring relative alternate object store %s",
350 relative_base, entry);
351 } else {
352 link_alt_odb_entry(entry, relative_base, depth);
9577e7e3 353 }
9577e7e3 354 }
6eac50d8
MH
355 string_list_clear(&entries, 0);
356 free(alt_copy);
d5a63b99
JH
357}
358
5e73633d 359void read_info_alternates(const char * relative_base, int depth)
d5a63b99 360{
9577e7e3 361 char *map;
dc49cd76 362 size_t mapsz;
d5a63b99 363 struct stat st;
9cb18f56
JM
364 const char alt_file_name[] = "info/alternates";
365 /* Given that relative_base is no longer than PATH_MAX,
366 ensure that "path" has enough space to append "/", the
367 file name, "info/alternates", and a trailing NUL. */
368 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 369 int fd;
d5a63b99 370
9cb18f56 371 sprintf(path, "%s/%s", relative_base, alt_file_name);
f4e51683 372 fd = git_open_noatime(path);
d5a63b99
JH
373 if (fd < 0)
374 return;
375 if (fstat(fd, &st) || (st.st_size == 0)) {
376 close(fd);
9a217f2a 377 return;
ace1534d 378 }
dc49cd76
SP
379 mapsz = xsize_t(st.st_size);
380 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 381 close(fd);
d5a63b99 382
c5950164 383 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
c2f493a4 384
dc49cd76 385 munmap(map, mapsz);
ace1534d
JH
386}
387
bef70b22
DB
388void add_to_alternates_file(const char *reference)
389{
390 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
acd3b9ec 391 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
e6baf4a1 392 char *alt = mkpath("%s\n", reference);
bef70b22
DB
393 write_or_die(fd, alt, strlen(alt));
394 if (commit_lock_file(lock))
395 die("could not close alternates file");
396 if (alt_odb_tail)
c5950164 397 link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
bef70b22
DB
398}
399
d79796bc
JH
400void foreach_alt_odb(alt_odb_fn fn, void *cb)
401{
402 struct alternate_object_database *ent;
403
404 prepare_alt_odb();
405 for (ent = alt_odb_list; ent; ent = ent->next)
406 if (fn(ent, cb))
407 return;
408}
409
c2f493a4
MW
410void prepare_alt_odb(void)
411{
554fe20d 412 const char *alt;
c2f493a4 413
7dc24aa5
SP
414 if (alt_odb_tail)
415 return;
416
c2f493a4
MW
417 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
418 if (!alt) alt = "";
419
c2f493a4 420 alt_odb_tail = &alt_odb_list;
c5950164 421 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
422
423 read_info_alternates(get_object_directory(), 0);
424}
425
0f4dc14a 426static int has_loose_object_local(const unsigned char *sha1)
ace1534d 427{
ace1534d 428 char *name = sha1_file_name(sha1);
0f4dc14a
BC
429 return !access(name, F_OK);
430}
ace1534d 431
0f4dc14a
BC
432int has_loose_object_nonlocal(const unsigned char *sha1)
433{
434 struct alternate_object_database *alt;
9a217f2a 435 prepare_alt_odb();
d5a63b99 436 for (alt = alt_odb_list; alt; alt = alt->next) {
0f4dc14a 437 fill_sha1_path(alt->name, sha1);
c529d75a
LT
438 if (!access(alt->base, F_OK))
439 return 1;
ace1534d 440 }
c529d75a 441 return 0;
ace1534d
JH
442}
443
0f4dc14a
BC
444static int has_loose_object(const unsigned char *sha1)
445{
446 return has_loose_object_local(sha1) ||
447 has_loose_object_nonlocal(sha1);
448}
449
60bb8b14 450static unsigned int pack_used_ctr;
a53128b6
SP
451static unsigned int pack_mmap_calls;
452static unsigned int peak_pack_open_windows;
453static unsigned int pack_open_windows;
c7934306
SP
454static unsigned int pack_open_fds;
455static unsigned int pack_max_fds;
a53128b6 456static size_t peak_pack_mapped;
60bb8b14 457static size_t pack_mapped;
9a217f2a 458struct packed_git *packed_git;
1f688557 459
b79d18c9 460void pack_report(void)
a53128b6
SP
461{
462 fprintf(stderr,
e05db0fd
PR
463 "pack_report: getpagesize() = %10" SZ_FMT "\n"
464 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
465 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
466 sz_fmt(getpagesize()),
467 sz_fmt(packed_git_window_size),
468 sz_fmt(packed_git_limit));
a53128b6
SP
469 fprintf(stderr,
470 "pack_report: pack_used_ctr = %10u\n"
471 "pack_report: pack_mmap_calls = %10u\n"
472 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
473 "pack_report: pack_mapped = "
474 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
475 pack_used_ctr,
476 pack_mmap_calls,
477 pack_open_windows, peak_pack_open_windows,
9e42d6a1 478 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
479}
480
42873078 481static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
482{
483 void *idx_map;
42873078 484 struct pack_idx_header *hdr;
dc49cd76 485 size_t idx_size;
74e34e1f 486 uint32_t version, nr, i, *index;
f4e51683 487 int fd = git_open_noatime(path);
1f688557 488 struct stat st;
42873078 489
1f688557
JH
490 if (fd < 0)
491 return -1;
492 if (fstat(fd, &st)) {
493 close(fd);
494 return -1;
495 }
dc49cd76 496 idx_size = xsize_t(st.st_size);
2d88451b
SP
497 if (idx_size < 4 * 256 + 20 + 20) {
498 close(fd);
499 return error("index file %s is too small", path);
500 }
c4712e45 501 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 502 close(fd);
1f688557 503
42873078
NP
504 hdr = idx_map;
505 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
506 version = ntohl(hdr->idx_version);
507 if (version < 2 || version > 2) {
508 munmap(idx_map, idx_size);
6e1c2344 509 return error("index file %s is version %"PRIu32
74e34e1f
NP
510 " and is not supported by this binary"
511 " (try upgrading GIT to a newer version)",
512 path, version);
513 }
514 } else
515 version = 1;
df1b059d 516
1f688557 517 nr = 0;
42873078 518 index = idx_map;
74e34e1f
NP
519 if (version > 1)
520 index += 2; /* skip index header */
1f688557 521 for (i = 0; i < 256; i++) {
326bf396 522 uint32_t n = ntohl(index[i]);
2d88451b
SP
523 if (n < nr) {
524 munmap(idx_map, idx_size);
df1b059d 525 return error("non-monotonic index %s", path);
2d88451b 526 }
1f688557
JH
527 nr = n;
528 }
529
74e34e1f
NP
530 if (version == 1) {
531 /*
532 * Total size:
533 * - 256 index entries 4 bytes each
534 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
535 * - 20-byte SHA1 of the packfile
536 * - 20-byte SHA1 file checksum
537 */
538 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
539 munmap(idx_map, idx_size);
eef427a0 540 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
541 }
542 } else if (version == 2) {
543 /*
544 * Minimum size:
545 * - 8 bytes of header
546 * - 256 index entries 4 bytes each
547 * - 20-byte sha1 entry * nr
548 * - 4-byte crc entry * nr
549 * - 4-byte offset entry * nr
550 * - 20-byte SHA1 of the packfile
551 * - 20-byte SHA1 file checksum
552 * And after the 4-byte offset table might be a
553 * variable sized table containing 8-byte entries
554 * for offsets larger than 2^31.
555 */
556 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
557 unsigned long max_size = min_size;
558 if (nr)
559 max_size += (nr - 1)*8;
560 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 561 munmap(idx_map, idx_size);
eef427a0 562 return error("wrong index v2 file size in %s", path);
74e34e1f 563 }
7109c889
JH
564 if (idx_size != min_size &&
565 /*
566 * make sure we can deal with large pack offsets.
567 * 31-bit signed offset won't be enough, neither
568 * 32-bit unsigned one will be.
569 */
570 (sizeof(off_t) <= 4)) {
571 munmap(idx_map, idx_size);
572 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 573 }
2d88451b 574 }
1f688557 575
74e34e1f 576 p->index_version = version;
42873078
NP
577 p->index_data = idx_map;
578 p->index_size = idx_size;
57059091 579 p->num_objects = nr;
1f688557
JH
580 return 0;
581}
582
bc8e478a 583int open_pack_index(struct packed_git *p)
d079837e
SP
584{
585 char *idx_name;
586 int ret;
587
588 if (p->index_data)
589 return 0;
590
591 idx_name = xstrdup(p->pack_name);
592 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
593 ret = check_packed_git_idx(idx_name, p);
594 free(idx_name);
595 return ret;
596}
597
11daf39b
SP
598static void scan_windows(struct packed_git *p,
599 struct packed_git **lru_p,
600 struct pack_window **lru_w,
601 struct pack_window **lru_l)
1f688557 602{
11daf39b
SP
603 struct pack_window *w, *w_l;
604
605 for (w_l = NULL, w = p->windows; w; w = w->next) {
606 if (!w->inuse_cnt) {
607 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
608 *lru_p = p;
609 *lru_w = w;
610 *lru_l = w_l;
54044bf8 611 }
54044bf8 612 }
11daf39b 613 w_l = w;
f9253394 614 }
11daf39b
SP
615}
616
7c3ecb32 617static int unuse_one_window(struct packed_git *current)
11daf39b
SP
618{
619 struct packed_git *p, *lru_p = NULL;
620 struct pack_window *lru_w = NULL, *lru_l = NULL;
621
622 if (current)
623 scan_windows(current, &lru_p, &lru_w, &lru_l);
624 for (p = packed_git; p; p = p->next)
625 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
626 if (lru_p) {
627 munmap(lru_w->base, lru_w->len);
628 pack_mapped -= lru_w->len;
629 if (lru_l)
630 lru_l->next = lru_w->next;
7c3ecb32 631 else
54044bf8 632 lru_p->windows = lru_w->next;
54044bf8 633 free(lru_w);
a53128b6 634 pack_open_windows--;
54044bf8
SP
635 return 1;
636 }
637 return 0;
f9253394
JH
638}
639
7c3ecb32 640void release_pack_memory(size_t need)
97bfeb34
SP
641{
642 size_t cur = pack_mapped;
7c3ecb32 643 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
97bfeb34
SP
644 ; /* nothing */
645}
646
58ecbd5e
JN
647void *xmmap(void *start, size_t length,
648 int prot, int flags, int fd, off_t offset)
649{
650 void *ret = mmap(start, length, prot, flags, fd, offset);
651 if (ret == MAP_FAILED) {
652 if (!length)
653 return NULL;
7c3ecb32 654 release_pack_memory(length);
58ecbd5e
JN
655 ret = mmap(start, length, prot, flags, fd, offset);
656 if (ret == MAP_FAILED)
657 die_errno("Out of memory? mmap failed");
658 }
659 return ret;
660}
661
c9ced051
SP
662void close_pack_windows(struct packed_git *p)
663{
664 while (p->windows) {
665 struct pack_window *w = p->windows;
666
667 if (w->inuse_cnt)
668 die("pack '%s' still has open windows to it",
669 p->pack_name);
670 munmap(w->base, w->len);
671 pack_mapped -= w->len;
672 pack_open_windows--;
673 p->windows = w->next;
674 free(w);
675 }
676}
677
88d0db55
BC
678/*
679 * The LRU pack is the one with the oldest MRU window, preferring packs
680 * with no used windows, or the oldest mtime if it has no windows allocated.
681 */
682static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
683{
684 struct pack_window *w, *this_mru_w;
685 int has_windows_inuse = 0;
686
687 /*
688 * Reject this pack if it has windows and the previously selected
689 * one does not. If this pack does not have windows, reject
690 * it if the pack file is newer than the previously selected one.
691 */
692 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
693 return;
694
695 for (w = this_mru_w = p->windows; w; w = w->next) {
696 /*
697 * Reject this pack if any of its windows are in use,
698 * but the previously selected pack did not have any
699 * inuse windows. Otherwise, record that this pack
700 * has windows in use.
701 */
702 if (w->inuse_cnt) {
703 if (*accept_windows_inuse)
704 has_windows_inuse = 1;
705 else
706 return;
707 }
708
709 if (w->last_used > this_mru_w->last_used)
710 this_mru_w = w;
711
712 /*
713 * Reject this pack if it has windows that have been
714 * used more recently than the previously selected pack.
715 * If the previously selected pack had windows inuse and
716 * we have not encountered a window in this pack that is
717 * inuse, skip this check since we prefer a pack with no
718 * inuse windows to one that has inuse windows.
719 */
720 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
721 this_mru_w->last_used > (*mru_w)->last_used)
722 return;
723 }
724
725 /*
726 * Select this pack.
727 */
728 *mru_w = this_mru_w;
729 *lru_p = p;
730 *accept_windows_inuse = has_windows_inuse;
731}
732
733static int close_one_pack(void)
734{
735 struct packed_git *p, *lru_p = NULL;
736 struct pack_window *mru_w = NULL;
737 int accept_windows_inuse = 1;
738
739 for (p = packed_git; p; p = p->next) {
740 if (p->pack_fd == -1)
741 continue;
742 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
743 }
744
745 if (lru_p) {
746 close(lru_p->pack_fd);
747 pack_open_fds--;
748 lru_p->pack_fd = -1;
749 return 1;
750 }
751
752 return 0;
753}
754
03e79c88 755void unuse_pack(struct pack_window **w_cursor)
f9253394 756{
03e79c88
SP
757 struct pack_window *w = *w_cursor;
758 if (w) {
759 w->inuse_cnt--;
760 *w_cursor = NULL;
761 }
1f688557
JH
762}
763
fa5fc15d
SP
764void close_pack_index(struct packed_git *p)
765{
766 if (p->index_data) {
767 munmap((void *)p->index_data, p->index_size);
768 p->index_data = NULL;
769 }
770}
771
c74faea1
NP
772/*
773 * This is used by git-repack in case a newly created pack happens to
774 * contain the same set of objects as an existing one. In that case
775 * the resulting file might be different even if its name would be the
776 * same. It is best to close any reference to the old pack before it is
777 * replaced on disk. Of course no index pointers nor windows for given pack
778 * must subsist at this point. If ever objects from this pack are requested
779 * again, the new version of the pack will be reinitialized through
780 * reprepare_packed_git().
781 */
782void free_pack_by_name(const char *pack_name)
783{
784 struct packed_git *p, **pp = &packed_git;
785
786 while (*pp) {
787 p = *pp;
788 if (strcmp(pack_name, p->pack_name) == 0) {
fa3a0c94 789 clear_delta_base_cache();
c74faea1 790 close_pack_windows(p);
c7934306 791 if (p->pack_fd != -1) {
c74faea1 792 close(p->pack_fd);
c7934306
SP
793 pack_open_fds--;
794 }
fa5fc15d 795 close_pack_index(p);
c74faea1
NP
796 free(p->bad_object_sha1);
797 *pp = p->next;
c01f51cc
NTND
798 if (last_found_pack == p)
799 last_found_pack = NULL;
c74faea1
NP
800 free(p);
801 return;
802 }
803 pp = &p->next;
804 }
805}
806
a0788266
JS
807static unsigned int get_max_fd_limit(void)
808{
809#ifdef RLIMIT_NOFILE
810 struct rlimit lim;
811
812 if (getrlimit(RLIMIT_NOFILE, &lim))
813 die_errno("cannot get RLIMIT_NOFILE");
814
815 return lim.rlim_cur;
816#elif defined(_SC_OPEN_MAX)
817 return sysconf(_SC_OPEN_MAX);
818#elif defined(OPEN_MAX)
819 return OPEN_MAX;
820#else
821 return 1; /* see the caller ;-) */
822#endif
823}
824
3cf8b462
SP
825/*
826 * Do not call this directly as this leaks p->pack_fd on error return;
827 * call open_packed_git() instead.
828 */
829static int open_packed_git_1(struct packed_git *p)
1f688557 830{
9bc879c1
SP
831 struct stat st;
832 struct pack_header hdr;
833 unsigned char sha1[20];
834 unsigned char *idx_sha1;
2c039da8 835 long fd_flag;
9bc879c1 836
d079837e
SP
837 if (!p->index_data && open_pack_index(p))
838 return error("packfile %s index unavailable", p->pack_name);
839
c7934306 840 if (!pack_max_fds) {
a0788266 841 unsigned int max_fds = get_max_fd_limit();
c7934306
SP
842
843 /* Save 3 for stdin/stdout/stderr, 22 for work */
844 if (25 < max_fds)
845 pack_max_fds = max_fds - 25;
846 else
847 pack_max_fds = 1;
848 }
849
88d0db55 850 while (pack_max_fds <= pack_open_fds && close_one_pack())
c7934306
SP
851 ; /* nothing */
852
f4e51683 853 p->pack_fd = git_open_noatime(p->pack_name);
9bc879c1 854 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 855 return -1;
c7934306 856 pack_open_fds++;
9bc879c1
SP
857
858 /* If we created the struct before we had the pack we lack size. */
bf592c50 859 if (!p->pack_size) {
bf592c50 860 if (!S_ISREG(st.st_mode))
072db278 861 return error("packfile %s not a regular file", p->pack_name);
bf592c50 862 p->pack_size = st.st_size;
9bc879c1 863 } else if (p->pack_size != st.st_size)
072db278 864 return error("packfile %s size changed", p->pack_name);
9bc879c1 865
2c039da8
JH
866 /* We leave these file descriptors open with sliding mmap;
867 * there is no point keeping them open across exec(), though.
868 */
869 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
870 if (fd_flag < 0)
072db278 871 return error("cannot determine file descriptor flags");
2c039da8
JH
872 fd_flag |= FD_CLOEXEC;
873 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 874 return error("cannot set FD_CLOEXEC");
2c039da8 875
9bc879c1 876 /* Verify we recognize this pack file format. */
e6e2bd62 877 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 878 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 879 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 880 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 881 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
882 return error("packfile %s is version %"PRIu32" and not"
883 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
884 p->pack_name, ntohl(hdr.hdr_version));
885
886 /* Verify the pack matches its index. */
57059091 887 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
888 return error("packfile %s claims to have %"PRIu32" objects"
889 " while index indicates %"PRIu32" objects",
57059091
NP
890 p->pack_name, ntohl(hdr.hdr_entries),
891 p->num_objects);
9bc879c1 892 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 893 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 894 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 895 return error("packfile %s signature is unavailable", p->pack_name);
42873078 896 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 897 if (hashcmp(sha1, idx_sha1))
072db278
SP
898 return error("packfile %s does not match index", p->pack_name);
899 return 0;
9bc879c1
SP
900}
901
3cf8b462
SP
902static int open_packed_git(struct packed_git *p)
903{
904 if (!open_packed_git_1(p))
905 return 0;
906 if (p->pack_fd != -1) {
907 close(p->pack_fd);
c7934306 908 pack_open_fds--;
3cf8b462
SP
909 p->pack_fd = -1;
910 }
911 return -1;
912}
913
c4001d92 914static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
915{
916 /* We must promise at least 20 bytes (one hash) after the
917 * offset is available from this window, otherwise the offset
918 * is not actually in this window and a different window (which
919 * has that one hash excess) must be used. This is to support
920 * the object header and delta base parsing routines below.
921 */
922 off_t win_off = win->offset;
923 return win_off <= offset
924 && (offset + 20) <= (win_off + win->len);
925}
926
4b25d091 927unsigned char *use_pack(struct packed_git *p,
03e79c88 928 struct pack_window **w_cursor,
c4001d92 929 off_t offset,
ef49a7a0 930 unsigned long *left)
9bc879c1 931{
60bb8b14 932 struct pack_window *win = *w_cursor;
03e79c88 933
a9d98a14 934 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
935 * pointless to ask for an offset into the middle of that
936 * hash, and the in_window function above wouldn't match
937 * don't allow an offset too close to the end of the file.
938 */
d131b7af
SP
939 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
940 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
941 if (offset > (p->pack_size - 20))
942 die("offset beyond end of packfile (truncated pack?)");
943
944 if (!win || !in_window(win, offset)) {
945 if (win)
946 win->inuse_cnt--;
947 for (win = p->windows; win; win = win->next) {
948 if (in_window(win, offset))
949 break;
950 }
951 if (!win) {
78a28df9 952 size_t window_align = packed_git_window_size / 2;
dc49cd76 953 off_t len;
d131b7af
SP
954
955 if (p->pack_fd == -1 && open_packed_git(p))
956 die("packfile %s cannot be accessed", p->pack_name);
957
60bb8b14 958 win = xcalloc(1, sizeof(*win));
78a28df9 959 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
960 len = p->pack_size - win->offset;
961 if (len > packed_git_window_size)
962 len = packed_git_window_size;
963 win->len = (size_t)len;
60bb8b14 964 pack_mapped += win->len;
11daf39b 965 while (packed_git_limit < pack_mapped
7c3ecb32 966 && unuse_one_window(p))
60bb8b14 967 ; /* nothing */
c4712e45 968 win->base = xmmap(NULL, win->len,
60bb8b14
SP
969 PROT_READ, MAP_PRIVATE,
970 p->pack_fd, win->offset);
971 if (win->base == MAP_FAILED)
73b4e4be
SP
972 die("packfile %s cannot be mapped: %s",
973 p->pack_name,
974 strerror(errno));
d131b7af
SP
975 if (!win->offset && win->len == p->pack_size
976 && !p->do_not_close) {
977 close(p->pack_fd);
978 pack_open_fds--;
979 p->pack_fd = -1;
980 }
a53128b6
SP
981 pack_mmap_calls++;
982 pack_open_windows++;
983 if (pack_mapped > peak_pack_mapped)
984 peak_pack_mapped = pack_mapped;
985 if (pack_open_windows > peak_pack_open_windows)
986 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
987 win->next = p->windows;
988 p->windows = win;
989 }
1f688557 990 }
03e79c88
SP
991 if (win != *w_cursor) {
992 win->last_used = pack_used_ctr++;
993 win->inuse_cnt++;
994 *w_cursor = win;
995 }
60bb8b14 996 offset -= win->offset;
03e79c88 997 if (left)
dc49cd76 998 *left = win->len - xsize_t(offset);
03e79c88 999 return win->base + offset;
1f688557
JH
1000}
1001
27d69a46
NP
1002static struct packed_git *alloc_packed_git(int extra)
1003{
1004 struct packed_git *p = xmalloc(sizeof(*p) + extra);
1005 memset(p, 0, sizeof(*p));
1006 p->pack_fd = -1;
1007 return p;
1008}
1009
e0500293
JN
1010static void try_to_free_pack_memory(size_t size)
1011{
7c3ecb32 1012 release_pack_memory(size);
e0500293
JN
1013}
1014
42873078 1015struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557 1016{
e0500293 1017 static int have_set_try_to_free_routine;
1f688557 1018 struct stat st;
27d69a46 1019 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 1020
e0500293
JN
1021 if (!have_set_try_to_free_routine) {
1022 have_set_try_to_free_routine = 1;
1023 set_try_to_free_routine(try_to_free_pack_memory);
1024 }
1025
42873078
NP
1026 /*
1027 * Make sure a corresponding .pack file exists and that
1028 * the index looks sane.
1029 */
1030 path_len -= strlen(".idx");
27d69a46
NP
1031 if (path_len < 1) {
1032 free(p);
1f688557 1033 return NULL;
27d69a46 1034 }
42873078 1035 memcpy(p->pack_name, path, path_len);
8d25931d
BC
1036
1037 strcpy(p->pack_name + path_len, ".keep");
1038 if (!access(p->pack_name, F_OK))
1039 p->pack_keep = 1;
1040
42873078 1041 strcpy(p->pack_name + path_len, ".pack");
d079837e 1042 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 1043 free(p);
1f688557
JH
1044 return NULL;
1045 }
42873078 1046
1f688557
JH
1047 /* ok, it looks sane as far as we can check without
1048 * actually mapping the pack file.
1049 */
1f688557 1050 p->pack_size = st.st_size;
9d835df2 1051 p->pack_local = local;
b867092f 1052 p->mtime = st.st_mtime;
42873078
NP
1053 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1054 hashclr(p->sha1);
1f688557
JH
1055 return p;
1056}
1057
7b64469a 1058struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 1059{
42873078 1060 const char *path = sha1_pack_name(sha1);
27d69a46 1061 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 1062
27d69a46
NP
1063 strcpy(p->pack_name, path);
1064 hashcpy(p->sha1, sha1);
42873078
NP
1065 if (check_packed_git_idx(idx_path, p)) {
1066 free(p);
bf592c50 1067 return NULL;
42873078 1068 }
bf592c50 1069
bf592c50
DB
1070 return p;
1071}
1072
1073void install_packed_git(struct packed_git *pack)
1074{
c7934306
SP
1075 if (pack->pack_fd != -1)
1076 pack_open_fds++;
1077
bf592c50
DB
1078 pack->next = packed_git;
1079 packed_git = pack;
1080}
1081
543c5caa
NTND
1082void (*report_garbage)(const char *desc, const char *path);
1083
1084static void report_helper(const struct string_list *list,
1085 int seen_bits, int first, int last)
1086{
1087 const char *msg;
1088 switch (seen_bits) {
1089 case 0:
1090 msg = "no corresponding .idx nor .pack";
1091 break;
1092 case 1:
1093 msg = "no corresponding .idx";
1094 break;
1095 case 2:
1096 msg = "no corresponding .pack";
1097 break;
1098 default:
1099 return;
1100 }
1101 for (; first < last; first++)
1102 report_garbage(msg, list->items[first].string);
1103}
1104
1105static void report_pack_garbage(struct string_list *list)
1106{
1107 int i, baselen = -1, first = 0, seen_bits = 0;
1108
1109 if (!report_garbage)
1110 return;
1111
1112 sort_string_list(list);
1113
1114 for (i = 0; i < list->nr; i++) {
1115 const char *path = list->items[i].string;
1116 if (baselen != -1 &&
1117 strncmp(path, list->items[first].string, baselen)) {
1118 report_helper(list, seen_bits, first, i);
1119 baselen = -1;
1120 seen_bits = 0;
1121 }
1122 if (baselen == -1) {
1123 const char *dot = strrchr(path, '.');
1124 if (!dot) {
1125 report_garbage("garbage found", path);
1126 continue;
1127 }
1128 baselen = dot - path + 1;
1129 first = i;
1130 }
1131 if (!strcmp(path + baselen, "pack"))
1132 seen_bits |= 1;
1133 else if (!strcmp(path + baselen, "idx"))
1134 seen_bits |= 2;
1135 }
1136 report_helper(list, seen_bits, first, list->nr);
1137}
1138
9d835df2 1139static void prepare_packed_git_one(char *objdir, int local)
1f688557 1140{
9cb18f56
JM
1141 /* Ensure that this buffer is large enough so that we can
1142 append "/pack/" without clobbering the stack even if
1143 strlen(objdir) were PATH_MAX. */
1144 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
1145 int len;
1146 DIR *dir;
1147 struct dirent *de;
543c5caa 1148 struct string_list garbage = STRING_LIST_INIT_DUP;
1f688557
JH
1149
1150 sprintf(path, "%s/pack", objdir);
1151 len = strlen(path);
1152 dir = opendir(path);
b5b16990 1153 if (!dir) {
26125f6b 1154 if (errno != ENOENT)
bd2afde8 1155 error("unable to open object pack directory: %s: %s",
26125f6b 1156 path, strerror(errno));
1f688557 1157 return;
b5b16990 1158 }
1f688557
JH
1159 path[len++] = '/';
1160 while ((de = readdir(dir)) != NULL) {
1161 int namelen = strlen(de->d_name);
1162 struct packed_git *p;
1163
543c5caa
NTND
1164 if (len + namelen + 1 > sizeof(path)) {
1165 if (report_garbage) {
1166 struct strbuf sb = STRBUF_INIT;
1167 strbuf_addf(&sb, "%.*s/%s", len - 1, path, de->d_name);
1168 report_garbage("path too long", sb.buf);
1169 strbuf_release(&sb);
1170 }
1171 continue;
1172 }
1173
1174 if (is_dot_or_dotdot(de->d_name))
9cb18f56
JM
1175 continue;
1176
1f688557 1177 strcpy(path + len, de->d_name);
d90906a9
NTND
1178
1179 if (has_extension(de->d_name, ".idx")) {
1180 /* Don't reopen a pack we already have. */
1181 for (p = packed_git; p; p = p->next) {
1182 if (!memcmp(path, p->pack_name, len + namelen - 4))
1183 break;
1184 }
1185 if (p == NULL &&
1186 /*
1187 * See if it really is a valid .idx file with
1188 * corresponding .pack file that we can map.
1189 */
1190 (p = add_packed_git(path, len + namelen, local)) != NULL)
1191 install_packed_git(p);
86f7780c 1192 }
543c5caa
NTND
1193
1194 if (!report_garbage)
1195 continue;
1196
1197 if (has_extension(de->d_name, ".idx") ||
1198 has_extension(de->d_name, ".pack") ||
1199 has_extension(de->d_name, ".keep"))
1200 string_list_append(&garbage, path);
1201 else
1202 report_garbage("garbage found", path);
1f688557 1203 }
5b35bcd5 1204 closedir(dir);
543c5caa
NTND
1205 report_pack_garbage(&garbage);
1206 string_list_clear(&garbage, 0);
1f688557
JH
1207}
1208
b867092f
JH
1209static int sort_pack(const void *a_, const void *b_)
1210{
1211 struct packed_git *a = *((struct packed_git **)a_);
1212 struct packed_git *b = *((struct packed_git **)b_);
1213 int st;
1214
1215 /*
1216 * Local packs tend to contain objects specific to our
1217 * variant of the project than remote ones. In addition,
1218 * remote ones could be on a network mounted filesystem.
1219 * Favor local ones for these reasons.
1220 */
1221 st = a->pack_local - b->pack_local;
1222 if (st)
1223 return -st;
1224
1225 /*
1226 * Younger packs tend to contain more recent objects,
1227 * and more recent objects tend to get accessed more
1228 * often.
1229 */
1230 if (a->mtime < b->mtime)
1231 return 1;
1232 else if (a->mtime == b->mtime)
1233 return 0;
1234 return -1;
1235}
1236
1237static void rearrange_packed_git(void)
1238{
1239 struct packed_git **ary, *p;
1240 int i, n;
1241
1242 for (n = 0, p = packed_git; p; p = p->next)
1243 n++;
1244 if (n < 2)
1245 return;
1246
1247 /* prepare an array of packed_git for easier sorting */
1248 ary = xcalloc(n, sizeof(struct packed_git *));
1249 for (n = 0, p = packed_git; p; p = p->next)
1250 ary[n++] = p;
1251
1252 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1253
1254 /* link them back again */
1255 for (i = 0; i < n - 1; i++)
1256 ary[i]->next = ary[i + 1];
1257 ary[n - 1]->next = NULL;
1258 packed_git = ary[0];
1259
1260 free(ary);
1261}
1262
637cdd9d 1263static int prepare_packed_git_run_once = 0;
9a217f2a 1264void prepare_packed_git(void)
1f688557 1265{
d5a63b99 1266 struct alternate_object_database *alt;
1f688557 1267
637cdd9d 1268 if (prepare_packed_git_run_once)
1f688557 1269 return;
9d835df2 1270 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1271 prepare_alt_odb();
d5a63b99 1272 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 1273 alt->name[-1] = 0;
9d835df2 1274 prepare_packed_git_one(alt->base, 0);
1494e038 1275 alt->name[-1] = '/';
1f688557 1276 }
b867092f 1277 rearrange_packed_git();
637cdd9d
JK
1278 prepare_packed_git_run_once = 1;
1279}
1280
fc04c412 1281void reprepare_packed_git(void)
637cdd9d 1282{
4b480c67 1283 discard_revindex();
637cdd9d
JK
1284 prepare_packed_git_run_once = 0;
1285 prepare_packed_git();
1f688557
JH
1286}
1287
8eca0b47
NP
1288static void mark_bad_packed_object(struct packed_git *p,
1289 const unsigned char *sha1)
1290{
1291 unsigned i;
1292 for (i = 0; i < p->num_bad_objects; i++)
1293 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1294 return;
1295 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1296 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1297 p->num_bad_objects++;
1298}
1299
b6c4cecc 1300static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1301{
1302 struct packed_git *p;
1303 unsigned i;
1304
1305 for (p = packed_git; p; p = p->next)
1306 for (i = 0; i < p->num_bad_objects; i++)
1307 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1308 return p;
1309 return NULL;
ac939109
NP
1310}
1311
090ea126
NTND
1312/*
1313 * With an in-core object data in "map", rehash it to make sure the
1314 * object name actually matches "sha1" to detect object corruption.
1315 * With "map" == NULL, try reading the object named with "sha1" using
1316 * the streaming interface and rehash it to do the same.
1317 */
1318int check_sha1_signature(const unsigned char *sha1, void *map,
1319 unsigned long size, const char *type)
0fcfd160
LT
1320{
1321 unsigned char real_sha1[20];
090ea126
NTND
1322 enum object_type obj_type;
1323 struct git_istream *st;
1324 git_SHA_CTX c;
1325 char hdr[32];
1326 int hdrlen;
1327
1328 if (map) {
1329 hash_sha1_file(map, size, type, real_sha1);
1330 return hashcmp(sha1, real_sha1) ? -1 : 0;
1331 }
1332
1333 st = open_istream(sha1, &obj_type, &size, NULL);
1334 if (!st)
1335 return -1;
1336
1337 /* Generate the header */
1338 hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
1339
1340 /* Sha1.. */
1341 git_SHA1_Init(&c);
1342 git_SHA1_Update(&c, hdr, hdrlen);
1343 for (;;) {
1344 char buf[1024 * 16];
1345 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1346
f54fac53
JK
1347 if (readlen < 0) {
1348 close_istream(st);
1349 return -1;
1350 }
090ea126
NTND
1351 if (!readlen)
1352 break;
1353 git_SHA1_Update(&c, buf, readlen);
1354 }
1355 git_SHA1_Final(real_sha1, &c);
1356 close_istream(st);
a89fccd2 1357 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1358}
1359
f4e51683 1360static int git_open_noatime(const char *name)
44d1c19e
LT
1361{
1362 static int sha1_file_open_flag = O_NOATIME;
44d1c19e 1363
f2e872aa
SP
1364 for (;;) {
1365 int fd = open(name, O_RDONLY | sha1_file_open_flag);
44d1c19e 1366 if (fd >= 0)
f2e872aa
SP
1367 return fd;
1368
f2e872aa
SP
1369 /* Might the failure be due to O_NOATIME? */
1370 if (errno != ENOENT && sha1_file_open_flag) {
44d1c19e 1371 sha1_file_open_flag = 0;
f2e872aa
SP
1372 continue;
1373 }
1374
1375 return -1;
44d1c19e 1376 }
44d1c19e
LT
1377}
1378
052fe5ea
JK
1379static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1380{
1381 char *name = sha1_file_name(sha1);
1382 struct alternate_object_database *alt;
1383
1384 if (!lstat(name, st))
1385 return 0;
1386
1387 prepare_alt_odb();
1388 errno = ENOENT;
1389 for (alt = alt_odb_list; alt; alt = alt->next) {
1390 name = alt->name;
1391 fill_sha1_path(name, sha1);
1392 if (!lstat(alt->base, st))
1393 return 0;
1394 }
1395
1396 return -1;
1397}
1398
44d1c19e
LT
1399static int open_sha1_file(const unsigned char *sha1)
1400{
1401 int fd;
1402 char *name = sha1_file_name(sha1);
1403 struct alternate_object_database *alt;
1404
f4e51683 1405 fd = git_open_noatime(name);
44d1c19e
LT
1406 if (fd >= 0)
1407 return fd;
1408
1409 prepare_alt_odb();
1410 errno = ENOENT;
1411 for (alt = alt_odb_list; alt; alt = alt->next) {
1412 name = alt->name;
1413 fill_sha1_path(name, sha1);
f4e51683 1414 fd = git_open_noatime(alt->base);
44d1c19e
LT
1415 if (fd >= 0)
1416 return fd;
1417 }
1418 return -1;
1419}
1420
f0270efd 1421void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1422{
0fcfd160 1423 void *map;
144bde78 1424 int fd;
ace1534d 1425
44d1c19e
LT
1426 fd = open_sha1_file(sha1);
1427 map = NULL;
1428 if (fd >= 0) {
1429 struct stat st;
0fcfd160 1430
44d1c19e
LT
1431 if (!fstat(fd, &st)) {
1432 *size = xsize_t(st.st_size);
33e42de0
MM
1433 if (!*size) {
1434 /* mmap() is forbidden on empty files */
1435 error("object file %s is empty", sha1_file_name(sha1));
1436 return NULL;
1437 }
44d1c19e 1438 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1439 }
44d1c19e 1440 close(fd);
0fcfd160 1441 }
0fcfd160
LT
1442 return map;
1443}
1444
cc5c54e7
JH
1445/*
1446 * There used to be a second loose object header format which
1447 * was meant to mimic the in-pack format, allowing for direct
1448 * copy of the object data. This format turned up not to be
1449 * really worth it and we no longer write loose objects in that
1450 * format.
1451 */
1452static int experimental_loose_object(unsigned char *map)
bb6b8e4f
JH
1453{
1454 unsigned int word;
1455
1456 /*
7f684a2a
RT
1457 * We must determine if the buffer contains the standard
1458 * zlib-deflated stream or the experimental format based
1459 * on the in-pack object format. Compare the header byte
1460 * for each format:
1461 *
1462 * RFC1950 zlib w/ deflate : 0www1000 : 0 <= www <= 7
1463 * Experimental pack-based : Stttssss : ttt = 1,2,3,4
1464 *
1465 * If bit 7 is clear and bits 0-3 equal 8, the buffer MUST be
1466 * in standard loose-object format, UNLESS it is a Git-pack
1467 * format object *exactly* 8 bytes in size when inflated.
1468 *
1469 * However, RFC1950 also specifies that the 1st 16-bit word
1470 * must be divisible by 31 - this checksum tells us our buffer
1471 * is in the standard format, giving a false positive only if
1472 * the 1st word of the Git-pack format object happens to be
1473 * divisible by 31, ie:
1474 * ((byte0 * 256) + byte1) % 31 = 0
1475 * => 0ttt10000www1000 % 31 = 0
1476 *
1477 * As it happens, this case can only arise for www=3 & ttt=1
1478 * - ie, a Commit object, which would have to be 8 bytes in
1479 * size. As no Commit can be that small, we find that the
1480 * combination of these two criteria (bitmask & checksum)
1481 * can always correctly determine the buffer format.
bb6b8e4f
JH
1482 */
1483 word = (map[0] << 8) + map[1];
7f684a2a 1484 if ((map[0] & 0x8F) == 0x08 && !(word % 31))
bb6b8e4f 1485 return 0;
cc5c54e7
JH
1486 else
1487 return 1;
bb6b8e4f
JH
1488}
1489
09ded04b
NP
1490unsigned long unpack_object_header_buffer(const unsigned char *buf,
1491 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1492{
ad1ed5ee 1493 unsigned shift;
48fb7deb 1494 unsigned long size, c;
ad1ed5ee
JH
1495 unsigned long used = 0;
1496
1497 c = buf[used++];
1498 *type = (c >> 4) & 7;
1499 size = c & 15;
1500 shift = 4;
1501 while (c & 0x80) {
f630cfda 1502 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1503 error("bad object header");
ea4f9685
JH
1504 size = used = 0;
1505 break;
09ded04b 1506 }
ad1ed5ee
JH
1507 c = buf[used++];
1508 size += (c & 0x7f) << shift;
1509 shift += 7;
1510 }
1511 *sizep = size;
1512 return used;
1513}
1514
eb4f4076 1515int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
ad1ed5ee
JH
1516{
1517 unsigned long size, used;
1518 static const char valid_loose_object_type[8] = {
1519 0, /* OBJ_EXT */
1520 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1521 0, /* "delta" and others are invalid in a loose object */
93821bd9 1522 };
ad1ed5ee 1523 enum object_type type;
93821bd9 1524
c4483576
LT
1525 /* Get the data stream */
1526 memset(stream, 0, sizeof(*stream));
1527 stream->next_in = map;
1528 stream->avail_in = mapsize;
1529 stream->next_out = buffer;
93821bd9
LT
1530 stream->avail_out = bufsiz;
1531
cc5c54e7
JH
1532 if (experimental_loose_object(map)) {
1533 /*
1534 * The old experimental format we no longer produce;
1535 * we can still read it.
1536 */
1537 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1538 if (!used || !valid_loose_object_type[type])
1539 return -1;
1540 map += used;
1541 mapsize -= used;
726f852b 1542
cc5c54e7
JH
1543 /* Set up the stream for the rest.. */
1544 stream->next_in = map;
1545 stream->avail_in = mapsize;
1546 git_inflate_init(stream);
93821bd9 1547
cc5c54e7
JH
1548 /* And generate the fake traditional header */
1549 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1550 typename(type), size);
1551 return 0;
1552 }
39c68542 1553 git_inflate_init(stream);
cc5c54e7 1554 return git_inflate(stream, 0);
c4483576
LT
1555}
1556
ef49a7a0 1557static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1558{
1559 int bytes = strlen(buffer) + 1;
3aee68aa 1560 unsigned char *buf = xmallocz(size);
93821bd9 1561 unsigned long n;
7efbff75 1562 int status = Z_OK;
5180cacc 1563
93821bd9
LT
1564 n = stream->total_out - bytes;
1565 if (n > size)
1566 n = size;
1567 memcpy(buf, (char *) buffer + bytes, n);
1568 bytes = n;
456cdf6e
LT
1569 if (bytes <= size) {
1570 /*
1571 * The above condition must be (bytes <= size), not
1572 * (bytes < size). In other words, even though we
ccf5ace0 1573 * expect no more output and set avail_out to zero,
456cdf6e
LT
1574 * the input zlib stream may have bytes that express
1575 * "this concludes the stream", and we *do* want to
1576 * eat that input.
1577 *
1578 * Otherwise we would not be able to test that we
1579 * consumed all the input to reach the expected size;
1580 * we also want to check that zlib tells us that all
1581 * went well with status == Z_STREAM_END at the end.
1582 */
5180cacc
LT
1583 stream->next_out = buf + bytes;
1584 stream->avail_out = size - bytes;
7efbff75 1585 while (status == Z_OK)
39c68542 1586 status = git_inflate(stream, Z_FINISH);
5180cacc 1587 }
456cdf6e 1588 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1589 git_inflate_end(stream);
7efbff75
JH
1590 return buf;
1591 }
1592
1593 if (status < 0)
1594 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1595 else if (stream->avail_in)
1596 error("garbage at end of loose object '%s'",
1597 sha1_to_hex(sha1));
1598 free(buf);
1599 return NULL;
5180cacc
LT
1600}
1601
1602/*
1603 * We used to just use "sscanf()", but that's actually way
1604 * too permissive for what we want to check. So do an anal
1605 * object header parse by hand.
1606 */
f0270efd 1607int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1608{
21666f1a 1609 char type[10];
5180cacc
LT
1610 int i;
1611 unsigned long size;
1612
1613 /*
a6080a0a 1614 * The type can be at most ten bytes (including the
5180cacc 1615 * terminating '\0' that we add), and is followed by
21666f1a 1616 * a space.
5180cacc 1617 */
21666f1a 1618 i = 0;
5180cacc
LT
1619 for (;;) {
1620 char c = *hdr++;
1621 if (c == ' ')
1622 break;
21666f1a
NP
1623 type[i++] = c;
1624 if (i >= sizeof(type))
5180cacc 1625 return -1;
5180cacc 1626 }
21666f1a 1627 type[i] = 0;
5180cacc
LT
1628
1629 /*
1630 * The length must follow immediately, and be in canonical
1631 * decimal format (ie "010" is not valid).
1632 */
1633 size = *hdr++ - '0';
1634 if (size > 9)
1635 return -1;
1636 if (size) {
1637 for (;;) {
1638 unsigned long c = *hdr - '0';
1639 if (c > 9)
1640 break;
1641 hdr++;
1642 size = size * 10 + c;
1643 }
1644 }
1645 *sizep = size;
1646
1647 /*
1648 * The length must be followed by a zero byte
1649 */
21666f1a 1650 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1651}
1652
7efbff75 1653static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1654{
5180cacc 1655 int ret;
ef49a7a0 1656 git_zstream stream;
5180cacc 1657 char hdr[8192];
0fcfd160 1658
5180cacc 1659 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1660 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1661 return NULL;
1662
7efbff75 1663 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1664}
1665
54dab52a
NP
1666unsigned long get_size_from_delta(struct packed_git *p,
1667 struct pack_window **w_curs,
1668 off_t curpos)
1669{
1670 const unsigned char *data;
1671 unsigned char delta_head[20], *in;
ef49a7a0 1672 git_zstream stream;
54dab52a
NP
1673 int st;
1674
1675 memset(&stream, 0, sizeof(stream));
1676 stream.next_out = delta_head;
1677 stream.avail_out = sizeof(delta_head);
1678
39c68542 1679 git_inflate_init(&stream);
54dab52a
NP
1680 do {
1681 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1682 stream.next_in = in;
39c68542 1683 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1684 curpos += stream.next_in - in;
1685 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1686 stream.total_out < sizeof(delta_head));
39c68542 1687 git_inflate_end(&stream);
3d77d877
NP
1688 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1689 error("delta data unpack-initial failed");
1690 return 0;
1691 }
54dab52a
NP
1692
1693 /* Examine the initial part of the delta to figure out
1694 * the result size.
1695 */
1696 data = delta_head;
1697
1698 /* ignore base size */
1699 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1700
1701 /* Read the result size */
1702 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1703}
1704
c4001d92 1705static off_t get_delta_base(struct packed_git *p,
03e79c88 1706 struct pack_window **w_curs,
c4001d92 1707 off_t *curpos,
21666f1a 1708 enum object_type type,
c4001d92 1709 off_t delta_obj_offset)
eb32d236 1710{
2b87c45b 1711 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1712 off_t base_offset;
eb32d236 1713
8d8a4ea5
SP
1714 /* use_pack() assured us we have [base_info, base_info + 20)
1715 * as a range that we can look at without walking off the
1716 * end of the mapped window. Its actually the hash size
1717 * that is assured. An OFS_DELTA longer than the hash size
1718 * is stupid, as then a REF_DELTA would be smaller to store.
1719 */
21666f1a 1720 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1721 unsigned used = 0;
1722 unsigned char c = base_info[used++];
1723 base_offset = c & 127;
1724 while (c & 128) {
1725 base_offset += 1;
8723f216 1726 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1727 return 0; /* overflow */
eb32d236
NP
1728 c = base_info[used++];
1729 base_offset = (base_offset << 7) + (c & 127);
1730 }
1731 base_offset = delta_obj_offset - base_offset;
d8f32556 1732 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 1733 return 0; /* out of bound */
2b87c45b 1734 *curpos += used;
21666f1a 1735 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1736 /* The base entry _must_ be in the same pack */
1737 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1738 *curpos += 20;
eb32d236
NP
1739 } else
1740 die("I am totally screwed");
2b87c45b 1741 return base_offset;
eb32d236
NP
1742}
1743
f8c8abc5
JH
1744int unpack_object_header(struct packed_git *p,
1745 struct pack_window **w_curs,
1746 off_t *curpos,
1747 unsigned long *sizep)
a733cb60 1748{
03e79c88 1749 unsigned char *base;
ef49a7a0 1750 unsigned long left;
ad1ed5ee 1751 unsigned long used;
2b87c45b 1752 enum object_type type;
a733cb60 1753
8d8a4ea5 1754 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 1755 * as a range that we can look at. (Its actually the hash
3dff5379 1756 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1757 * the maximum deflated object size is 2^137, which is just
1758 * insane, so we know won't exceed what we have been given.
1759 */
2b87c45b 1760 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
1761 used = unpack_object_header_buffer(base, left, &type, sizep);
1762 if (!used) {
1763 type = OBJ_BAD;
1764 } else
1765 *curpos += used;
ad1ed5ee 1766
2b87c45b 1767 return type;
a733cb60
LT
1768}
1769
790d96c0
TR
1770static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1771{
1772 int type;
1773 struct revindex_entry *revidx;
1774 const unsigned char *sha1;
1775 revidx = find_pack_revindex(p, obj_offset);
1776 if (!revidx)
1777 return OBJ_BAD;
1778 sha1 = nth_packed_object_sha1(p, revidx->nr);
1779 mark_bad_packed_object(p, sha1);
1780 type = sha1_object_info(sha1, NULL);
1781 if (type <= OBJ_NONE)
1782 return OBJ_BAD;
1783 return type;
1784}
1785
790d96c0
TR
1786#define POI_STACK_PREALLOC 64
1787
90191d37
JK
1788static enum object_type packed_to_object_type(struct packed_git *p,
1789 off_t obj_offset,
1790 enum object_type type,
1791 struct pack_window **w_curs,
1792 off_t curpos)
1f688557 1793{
790d96c0
TR
1794 off_t small_poi_stack[POI_STACK_PREALLOC];
1795 off_t *poi_stack = small_poi_stack;
1796 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
5db47c2b 1797
790d96c0
TR
1798 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1799 off_t base_offset;
90191d37 1800 unsigned long size;
790d96c0
TR
1801 /* Push the object we're going to leave behind */
1802 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1803 poi_stack_alloc = alloc_nr(poi_stack_nr);
1804 poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
1805 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1806 } else {
1807 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1808 }
1809 poi_stack[poi_stack_nr++] = obj_offset;
1810 /* If parsing the base offset fails, just unwind */
90191d37 1811 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
790d96c0
TR
1812 if (!base_offset)
1813 goto unwind;
1814 curpos = obj_offset = base_offset;
90191d37 1815 type = unpack_object_header(p, w_curs, &curpos, &size);
790d96c0
TR
1816 if (type <= OBJ_NONE) {
1817 /* If getting the base itself fails, we first
1818 * retry the base, otherwise unwind */
1819 type = retry_bad_packed_offset(p, base_offset);
1820 if (type > OBJ_NONE)
1821 goto out;
1822 goto unwind;
1823 }
1824 }
1825
21666f1a 1826 switch (type) {
790d96c0 1827 case OBJ_BAD:
a733cb60 1828 case OBJ_COMMIT:
a733cb60 1829 case OBJ_TREE:
a733cb60 1830 case OBJ_BLOB:
a733cb60 1831 case OBJ_TAG:
a69d0943 1832 break;
1f688557 1833 default:
3d77d877
NP
1834 error("unknown object type %i at offset %"PRIuMAX" in %s",
1835 type, (uintmax_t)obj_offset, p->pack_name);
1836 type = OBJ_BAD;
1f688557 1837 }
790d96c0
TR
1838
1839out:
1840 if (poi_stack != small_poi_stack)
1841 free(poi_stack);
21666f1a 1842 return type;
790d96c0
TR
1843
1844unwind:
1845 while (poi_stack_nr) {
1846 obj_offset = poi_stack[--poi_stack_nr];
1847 type = retry_bad_packed_offset(p, obj_offset);
1848 if (type > OBJ_NONE)
1849 goto out;
1850 }
1851 type = OBJ_BAD;
1852 goto out;
1f688557
JH
1853}
1854
90191d37 1855static int packed_object_info(struct packed_git *p, off_t obj_offset,
23c339c0 1856 struct object_info *oi)
90191d37
JK
1857{
1858 struct pack_window *w_curs = NULL;
1859 unsigned long size;
1860 off_t curpos = obj_offset;
1861 enum object_type type;
1862
412916ee
JK
1863 /*
1864 * We always get the representation type, but only convert it to
1865 * a "real" type later if the caller is interested.
1866 */
90191d37
JK
1867 type = unpack_object_header(p, &w_curs, &curpos, &size);
1868
23c339c0 1869 if (oi->sizep) {
90191d37
JK
1870 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1871 off_t tmp_pos = curpos;
1872 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1873 type, obj_offset);
1874 if (!base_offset) {
1875 type = OBJ_BAD;
1876 goto out;
1877 }
23c339c0
JK
1878 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1879 if (*oi->sizep == 0) {
90191d37
JK
1880 type = OBJ_BAD;
1881 goto out;
1882 }
1883 } else {
23c339c0 1884 *oi->sizep = size;
90191d37
JK
1885 }
1886 }
1887
23c339c0 1888 if (oi->disk_sizep) {
90191d37 1889 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
23c339c0 1890 *oi->disk_sizep = revidx[1].offset - obj_offset;
90191d37
JK
1891 }
1892
23c339c0
JK
1893 if (oi->typep) {
1894 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
1895 if (*oi->typep < 0) {
412916ee
JK
1896 type = OBJ_BAD;
1897 goto out;
1898 }
1899 }
90191d37
JK
1900
1901out:
1902 unuse_pack(&w_curs);
1903 return type;
1904}
1905
eb950c19 1906static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1907 struct pack_window **w_curs,
c4001d92 1908 off_t curpos,
eb950c19 1909 unsigned long size)
de530aaa
SP
1910{
1911 int st;
ef49a7a0 1912 git_zstream stream;
079afb18 1913 unsigned char *buffer, *in;
de530aaa 1914
4ab07e4d 1915 buffer = xmallocz(size);
de530aaa 1916 memset(&stream, 0, sizeof(stream));
de530aaa 1917 stream.next_out = buffer;
39eea7bd 1918 stream.avail_out = size + 1;
de530aaa 1919
39c68542 1920 git_inflate_init(&stream);
079afb18 1921 do {
2b87c45b 1922 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 1923 stream.next_in = in;
39c68542 1924 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
1925 if (!stream.avail_out)
1926 break; /* the payload is larger than it should be */
2b87c45b 1927 curpos += stream.next_in - in;
079afb18 1928 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 1929 git_inflate_end(&stream);
de530aaa
SP
1930 if ((st != Z_STREAM_END) || stream.total_out != size) {
1931 free(buffer);
1932 return NULL;
1933 }
1934
1935 return buffer;
1936}
1937
e5e01619
LT
1938#define MAX_DELTA_CACHE (256)
1939
18bdec11 1940static size_t delta_base_cached;
5e08ecbf
NP
1941
1942static struct delta_base_cache_lru_list {
1943 struct delta_base_cache_lru_list *prev;
1944 struct delta_base_cache_lru_list *next;
1945} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1946
e5e01619 1947static struct delta_base_cache_entry {
5e08ecbf
NP
1948 struct delta_base_cache_lru_list lru;
1949 void *data;
e5e01619
LT
1950 struct packed_git *p;
1951 off_t base_offset;
1952 unsigned long size;
e5e01619
LT
1953 enum object_type type;
1954} delta_base_cache[MAX_DELTA_CACHE];
1955
1956static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1957{
1958 unsigned long hash;
1959
1960 hash = (unsigned long)p + (unsigned long)base_offset;
1961 hash += (hash >> 8) + (hash >> 16);
3358004a 1962 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1963}
1964
84dd81c1
TR
1965static struct delta_base_cache_entry *
1966get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
5266d369
JH
1967{
1968 unsigned long hash = pack_entry_hash(p, base_offset);
84dd81c1
TR
1969 return delta_base_cache + hash;
1970}
1971
1972static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
1973 struct packed_git *p, off_t base_offset)
1974{
5266d369
JH
1975 return (ent->data && ent->p == p && ent->base_offset == base_offset);
1976}
1977
84dd81c1
TR
1978static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1979{
1980 struct delta_base_cache_entry *ent;
1981 ent = get_delta_base_cache_entry(p, base_offset);
1982 return eq_delta_base_cache_entry(ent, p, base_offset);
1983}
1984
1985static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1986{
1987 ent->data = NULL;
1988 ent->lru.next->prev = ent->lru.prev;
1989 ent->lru.prev->next = ent->lru.next;
1990 delta_base_cached -= ent->size;
1991}
1992
62f255ad 1993static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1994 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1995{
84dd81c1 1996 struct delta_base_cache_entry *ent;
e5e01619 1997 void *ret;
e5e01619 1998
84dd81c1
TR
1999 ent = get_delta_base_cache_entry(p, base_offset);
2000
2001 if (!eq_delta_base_cache_entry(ent, p, base_offset))
749bc58c 2002 return unpack_entry(p, base_offset, type, base_size);
e5e01619 2003
84dd81c1
TR
2004 ret = ent->data;
2005
2006 if (!keep_cache)
2007 clear_delta_base_cache_entry(ent);
2008 else
182af834 2009 ret = xmemdupz(ent->data, ent->size);
e5e01619
LT
2010 *type = ent->type;
2011 *base_size = ent->size;
2012 return ret;
62f255ad
LT
2013}
2014
18bdec11
SP
2015static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2016{
2017 if (ent->data) {
2018 free(ent->data);
2019 ent->data = NULL;
5e08ecbf
NP
2020 ent->lru.next->prev = ent->lru.prev;
2021 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
2022 delta_base_cached -= ent->size;
2023 }
2024}
2025
3d20c636
SP
2026void clear_delta_base_cache(void)
2027{
2028 unsigned long p;
2029 for (p = 0; p < MAX_DELTA_CACHE; p++)
2030 release_delta_base_cache(&delta_base_cache[p]);
2031}
2032
62f255ad
LT
2033static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2034 void *base, unsigned long base_size, enum object_type type)
2035{
5e08ecbf 2036 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 2037 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 2038 struct delta_base_cache_lru_list *lru;
e5e01619 2039
18bdec11
SP
2040 release_delta_base_cache(ent);
2041 delta_base_cached += base_size;
5e08ecbf
NP
2042
2043 for (lru = delta_base_cache_lru.next;
2044 delta_base_cached > delta_base_cache_limit
2045 && lru != &delta_base_cache_lru;
2046 lru = lru->next) {
2047 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
2048 if (f->type == OBJ_BLOB)
2049 release_delta_base_cache(f);
2050 }
5e08ecbf
NP
2051 for (lru = delta_base_cache_lru.next;
2052 delta_base_cached > delta_base_cache_limit
2053 && lru != &delta_base_cache_lru;
2054 lru = lru->next) {
2055 struct delta_base_cache_entry *f = (void *)lru;
2056 release_delta_base_cache(f);
2057 }
18bdec11 2058
e5e01619
LT
2059 ent->p = p;
2060 ent->base_offset = base_offset;
2061 ent->type = type;
2062 ent->data = base;
2063 ent->size = base_size;
5e08ecbf
NP
2064 ent->lru.next = &delta_base_cache_lru;
2065 ent->lru.prev = delta_base_cache_lru.prev;
2066 delta_base_cache_lru.prev->next = &ent->lru;
2067 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
2068}
2069
c2c5b270
CC
2070static void *read_object(const unsigned char *sha1, enum object_type *type,
2071 unsigned long *size);
2072
5f44324d
JH
2073static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2074{
2075 static FILE *log_file;
2076
b12ca963
NTND
2077 if (!log_pack_access)
2078 log_pack_access = getenv("GIT_TRACE_PACK_ACCESS");
2079 if (!log_pack_access)
2080 log_pack_access = no_log_pack_access;
2081 if (log_pack_access == no_log_pack_access)
2082 return;
2083
5f44324d
JH
2084 if (!log_file) {
2085 log_file = fopen(log_pack_access, "w");
2086 if (!log_file) {
2087 error("cannot open pack access log '%s' for writing: %s",
2088 log_pack_access, strerror(errno));
b12ca963 2089 log_pack_access = no_log_pack_access;
5f44324d
JH
2090 return;
2091 }
2092 }
2093 fprintf(log_file, "%s %"PRIuMAX"\n",
2094 p->pack_name, (uintmax_t)obj_offset);
2095 fflush(log_file);
2096}
2097
0e8189e2
NP
2098int do_check_packed_object_crc;
2099
abe601bb
TR
2100#define UNPACK_ENTRY_STACK_PREALLOC 64
2101struct unpack_entry_stack_ent {
2102 off_t obj_offset;
2103 off_t curpos;
2104 unsigned long size;
2105};
2106
c4001d92 2107void *unpack_entry(struct packed_git *p, off_t obj_offset,
abe601bb 2108 enum object_type *final_type, unsigned long *final_size)
1f688557 2109{
03e79c88 2110 struct pack_window *w_curs = NULL;
c4001d92 2111 off_t curpos = obj_offset;
abe601bb
TR
2112 void *data = NULL;
2113 unsigned long size;
2114 enum object_type type;
2115 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2116 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2117 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2118 int base_from_cache = 0;
1f688557 2119
b12ca963 2120 if (log_pack_access != no_log_pack_access)
5f44324d
JH
2121 write_pack_access_log(p, obj_offset);
2122
abe601bb
TR
2123 /* PHASE 1: drill down to the innermost base object */
2124 for (;;) {
2125 off_t base_offset;
2126 int i;
2127 struct delta_base_cache_entry *ent;
2128
77965f8b
NTND
2129 ent = get_delta_base_cache_entry(p, curpos);
2130 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2131 type = ent->type;
2132 data = ent->data;
2133 size = ent->size;
2134 clear_delta_base_cache_entry(ent);
2135 base_from_cache = 1;
2136 break;
2137 }
2138
abe601bb
TR
2139 if (do_check_packed_object_crc && p->index_version > 1) {
2140 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2141 unsigned long len = revidx[1].offset - obj_offset;
2142 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2143 const unsigned char *sha1 =
2144 nth_packed_object_sha1(p, revidx->nr);
2145 error("bad packed object CRC for %s",
2146 sha1_to_hex(sha1));
2147 mark_bad_packed_object(p, sha1);
2148 unuse_pack(&w_curs);
2149 return NULL;
2150 }
2151 }
2152
abe601bb
TR
2153 type = unpack_object_header(p, &w_curs, &curpos, &size);
2154 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2155 break;
2156
2157 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2158 if (!base_offset) {
2159 error("failed to validate delta base reference "
2160 "at offset %"PRIuMAX" from %s",
2161 (uintmax_t)curpos, p->pack_name);
2162 /* bail to phase 2, in hopes of recovery */
2163 data = NULL;
2164 break;
2165 }
2166
2167 /* push object, proceed to base */
2168 if (delta_stack_nr >= delta_stack_alloc
2169 && delta_stack == small_delta_stack) {
2170 delta_stack_alloc = alloc_nr(delta_stack_nr);
2171 delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
2172 memcpy(delta_stack, small_delta_stack,
2173 sizeof(*delta_stack)*delta_stack_nr);
2174 } else {
2175 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2176 }
2177 i = delta_stack_nr++;
2178 delta_stack[i].obj_offset = obj_offset;
2179 delta_stack[i].curpos = curpos;
2180 delta_stack[i].size = size;
2181
2182 curpos = obj_offset = base_offset;
0e8189e2
NP
2183 }
2184
abe601bb
TR
2185 /* PHASE 2: handle the base */
2186 switch (type) {
eb32d236
NP
2187 case OBJ_OFS_DELTA:
2188 case OBJ_REF_DELTA:
abe601bb
TR
2189 if (data)
2190 die("BUG in unpack_entry: left loop at a valid delta");
4d703a1a 2191 break;
a733cb60 2192 case OBJ_COMMIT:
a733cb60 2193 case OBJ_TREE:
a733cb60 2194 case OBJ_BLOB:
a733cb60 2195 case OBJ_TAG:
abe601bb
TR
2196 if (!base_from_cache)
2197 data = unpack_compressed_entry(p, &w_curs, curpos, size);
4d703a1a 2198 break;
1f688557 2199 default:
8eca0b47
NP
2200 data = NULL;
2201 error("unknown object type %i at offset %"PRIuMAX" in %s",
abe601bb
TR
2202 type, (uintmax_t)obj_offset, p->pack_name);
2203 }
2204
2205 /* PHASE 3: apply deltas in order */
2206
2207 /* invariants:
2208 * 'data' holds the base data, or NULL if there was corruption
2209 */
2210 while (delta_stack_nr) {
2211 void *delta_data;
2212 void *base = data;
2213 unsigned long delta_size, base_size = size;
2214 int i;
2215
2216 data = NULL;
2217
2218 if (base)
2219 add_delta_base_cache(p, obj_offset, base, base_size, type);
2220
2221 if (!base) {
2222 /*
2223 * We're probably in deep shit, but let's try to fetch
2224 * the required base anyway from another pack or loose.
2225 * This is costly but should happen only in the presence
2226 * of a corrupted pack, and is better than failing outright.
2227 */
2228 struct revindex_entry *revidx;
2229 const unsigned char *base_sha1;
2230 revidx = find_pack_revindex(p, obj_offset);
2231 if (revidx) {
2232 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2233 error("failed to read delta base object %s"
2234 " at offset %"PRIuMAX" from %s",
2235 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2236 p->pack_name);
2237 mark_bad_packed_object(p, base_sha1);
2238 base = read_object(base_sha1, &type, &base_size);
2239 }
2240 }
2241
2242 i = --delta_stack_nr;
2243 obj_offset = delta_stack[i].obj_offset;
2244 curpos = delta_stack[i].curpos;
2245 delta_size = delta_stack[i].size;
2246
2247 if (!base)
2248 continue;
2249
2250 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2251
2252 if (!delta_data) {
2253 error("failed to unpack compressed delta "
2254 "at offset %"PRIuMAX" from %s",
2255 (uintmax_t)curpos, p->pack_name);
abe601bb
TR
2256 data = NULL;
2257 continue;
2258 }
2259
2260 data = patch_delta(base, base_size,
2261 delta_data, delta_size,
2262 &size);
1ee886c1
JK
2263
2264 /*
2265 * We could not apply the delta; warn the user, but keep going.
2266 * Our failure will be noticed either in the next iteration of
2267 * the loop, or if this is the final delta, in the caller when
2268 * we return NULL. Those code paths will take care of making
2269 * a more explicit warning and retrying with another copy of
2270 * the object.
2271 */
abe601bb 2272 if (!data)
1ee886c1 2273 error("failed to apply delta");
abe601bb 2274
4b8f772c 2275 free(delta_data);
1f688557 2276 }
abe601bb
TR
2277
2278 *final_type = type;
2279 *final_size = size;
2280
03e79c88 2281 unuse_pack(&w_curs);
21666f1a 2282 return data;
1f688557
JH
2283}
2284
d079837e 2285const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 2286 uint32_t n)
9a217f2a 2287{
42873078 2288 const unsigned char *index = p->index_data;
d079837e
SP
2289 if (!index) {
2290 if (open_pack_index(p))
2291 return NULL;
2292 index = p->index_data;
2293 }
57059091 2294 if (n >= p->num_objects)
d72308e0 2295 return NULL;
74e34e1f
NP
2296 index += 4 * 256;
2297 if (p->index_version == 1) {
2298 return index + 24 * n + 4;
2299 } else {
2300 index += 8;
2301 return index + 20 * n;
2302 }
2303}
2304
99093238 2305off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
2306{
2307 const unsigned char *index = p->index_data;
2308 index += 4 * 256;
2309 if (p->index_version == 1) {
2310 return ntohl(*((uint32_t *)(index + 24 * n)));
2311 } else {
2312 uint32_t off;
2313 index += 8 + p->num_objects * (20 + 4);
2314 off = ntohl(*((uint32_t *)(index + 4 * n)));
2315 if (!(off & 0x80000000))
2316 return off;
2317 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2318 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2319 ntohl(*((uint32_t *)(index + 4)));
2320 }
9a217f2a
JH
2321}
2322
c4001d92 2323off_t find_pack_entry_one(const unsigned char *sha1,
43057304 2324 struct packed_git *p)
1f688557 2325{
42873078 2326 const uint32_t *level1_ofs = p->index_data;
42873078 2327 const unsigned char *index = p->index_data;
628522ec
JH
2328 unsigned hi, lo, stride;
2329 static int use_lookup = -1;
2330 static int debug_lookup = -1;
2331
2332 if (debug_lookup < 0)
2333 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 2334
d079837e
SP
2335 if (!index) {
2336 if (open_pack_index(p))
2337 return 0;
2338 level1_ofs = p->index_data;
2339 index = p->index_data;
2340 }
74e34e1f
NP
2341 if (p->index_version > 1) {
2342 level1_ofs += 2;
2343 index += 8;
2344 }
42873078 2345 index += 4 * 256;
74e34e1f
NP
2346 hi = ntohl(level1_ofs[*sha1]);
2347 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2348 if (p->index_version > 1) {
2349 stride = 20;
2350 } else {
2351 stride = 24;
2352 index += 4;
2353 }
2354
2355 if (debug_lookup)
6e1c2344 2356 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2357 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2358
2359 if (use_lookup < 0)
2360 use_lookup = !!getenv("GIT_USE_LOOKUP");
2361 if (use_lookup) {
2362 int pos = sha1_entry_pos(index, stride, 0,
2363 lo, hi, p->num_objects, sha1);
2364 if (pos < 0)
2365 return 0;
2366 return nth_packed_object_offset(p, pos);
2367 }
1f688557
JH
2368
2369 do {
74e34e1f 2370 unsigned mi = (lo + hi) / 2;
628522ec
JH
2371 int cmp = hashcmp(index + mi * stride, sha1);
2372
2373 if (debug_lookup)
2374 printf("lo %u hi %u rg %u mi %u\n",
2375 lo, hi, hi - lo, mi);
43057304 2376 if (!cmp)
74e34e1f 2377 return nth_packed_object_offset(p, mi);
1f688557
JH
2378 if (cmp > 0)
2379 hi = mi;
2380 else
2381 lo = mi+1;
2382 } while (lo < hi);
2383 return 0;
2384}
2385
4c080182 2386int is_pack_valid(struct packed_git *p)
d131b7af
SP
2387{
2388 /* An already open pack is known to be valid. */
2389 if (p->pack_fd != -1)
2390 return 1;
2391
2392 /* If the pack has one window completely covering the
2393 * file size, the pack is known to be valid even if
2394 * the descriptor is not currently open.
2395 */
2396 if (p->windows) {
2397 struct pack_window *w = p->windows;
2398
2399 if (!w->offset && w->len == p->pack_size)
2400 return 1;
2401 }
2402
2403 /* Force the pack to open to prove its valid. */
2404 return !open_packed_git(p);
2405}
2406
95099731
NTND
2407static int fill_pack_entry(const unsigned char *sha1,
2408 struct pack_entry *e,
2409 struct packed_git *p)
2410{
2411 off_t offset;
2412
2413 if (p->num_bad_objects) {
2414 unsigned i;
2415 for (i = 0; i < p->num_bad_objects; i++)
2416 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2417 return 0;
2418 }
2419
2420 offset = find_pack_entry_one(sha1, p);
2421 if (!offset)
2422 return 0;
2423
2424 /*
2425 * We are about to tell the caller where they can locate the
2426 * requested object. We better make sure the packfile is
2427 * still here and can be accessed before supplying that
2428 * answer, as it may have been deleted since the index was
2429 * loaded!
2430 */
2431 if (!is_pack_valid(p)) {
2432 warning("packfile %s cannot be accessed", p->pack_name);
2433 return 0;
2434 }
2435 e->offset = offset;
2436 e->p = p;
2437 hashcpy(e->sha1, sha1);
2438 return 1;
2439}
2440
4d6acb70 2441static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557
JH
2442{
2443 struct packed_git *p;
43057304 2444
1f688557 2445 prepare_packed_git();
f7c22cc6
NP
2446 if (!packed_git)
2447 return 0;
1f688557 2448
c01f51cc
NTND
2449 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2450 return 1;
8eca0b47 2451
c01f51cc
NTND
2452 for (p = packed_git; p; p = p->next) {
2453 if (p == last_found_pack || !fill_pack_entry(sha1, e, p))
2454 continue;
f7c22cc6 2455
c01f51cc
NTND
2456 last_found_pack = p;
2457 return 1;
2458 }
1f688557
JH
2459 return 0;
2460}
2461
a6080a0a 2462struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2463 struct packed_git *packs)
2464{
2465 struct packed_git *p;
bf592c50
DB
2466
2467 for (p = packs; p; p = p->next) {
43057304 2468 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2469 return p;
2470 }
2471 return NULL;
21666f1a 2472
bf592c50
DB
2473}
2474
052fe5ea 2475static int sha1_loose_object_info(const unsigned char *sha1,
23c339c0 2476 struct object_info *oi)
65c2e0c3 2477{
36e4d74a 2478 int status;
65c2e0c3
JH
2479 unsigned long mapsize, size;
2480 void *map;
ef49a7a0 2481 git_zstream stream;
d65a16f6 2482 char hdr[32];
65c2e0c3 2483
052fe5ea
JK
2484 /*
2485 * If we don't care about type or size, then we don't
2486 * need to look inside the object at all.
2487 */
23c339c0
JK
2488 if (!oi->typep && !oi->sizep) {
2489 if (oi->disk_sizep) {
052fe5ea
JK
2490 struct stat st;
2491 if (stat_sha1_file(sha1, &st) < 0)
2492 return -1;
23c339c0 2493 *oi->disk_sizep = st.st_size;
052fe5ea
JK
2494 }
2495 return 0;
2496 }
2497
bb6b8e4f 2498 map = map_sha1_file(sha1, &mapsize);
f0df4ed5 2499 if (!map)
dbea72a8 2500 return -1;
23c339c0
JK
2501 if (oi->disk_sizep)
2502 *oi->disk_sizep = mapsize;
36e4d74a
JH
2503 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2504 status = error("unable to unpack %s header",
2505 sha1_to_hex(sha1));
21666f1a 2506 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 2507 status = error("unable to parse %s header", sha1_to_hex(sha1));
23c339c0
JK
2508 else if (oi->sizep)
2509 *oi->sizep = size;
39c68542 2510 git_inflate_end(&stream);
65c2e0c3 2511 munmap(map, mapsize);
23c339c0
JK
2512 if (oi->typep)
2513 *oi->typep = status;
052fe5ea 2514 return 0;
65c2e0c3
JH
2515}
2516
de7b5d62 2517int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
f0df4ed5 2518{
c4d9986f 2519 struct cached_object *co;
f0df4ed5 2520 struct pack_entry e;
5b086407 2521 int rtype;
f0df4ed5 2522
c4d9986f
NTND
2523 co = find_cached_object(sha1);
2524 if (co) {
5b086407
JK
2525 if (oi->typep)
2526 *(oi->typep) = co->type;
9a490590
JH
2527 if (oi->sizep)
2528 *(oi->sizep) = co->size;
161f00e7
JK
2529 if (oi->disk_sizep)
2530 *(oi->disk_sizep) = 0;
9a490590 2531 oi->whence = OI_CACHED;
5b086407 2532 return 0;
c4d9986f
NTND
2533 }
2534
cd673c1f 2535 if (!find_pack_entry(sha1, &e)) {
ddd63e64 2536 /* Most likely it's a loose object. */
23c339c0 2537 if (!sha1_loose_object_info(sha1, oi)) {
9a490590 2538 oi->whence = OI_LOOSE;
5b086407 2539 return 0;
9a490590 2540 }
ddd63e64
SG
2541
2542 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 2543 reprepare_packed_git();
cd673c1f 2544 if (!find_pack_entry(sha1, &e))
052fe5ea 2545 return -1;
f0df4ed5 2546 }
3d77d877 2547
23c339c0 2548 rtype = packed_object_info(e.p, e.offset, oi);
412916ee 2549 if (rtype < 0) {
3d77d877 2550 mark_bad_packed_object(e.p, sha1);
de7b5d62 2551 return sha1_object_info_extended(sha1, oi, 0);
5266d369
JH
2552 } else if (in_delta_base_cache(e.p, e.offset)) {
2553 oi->whence = OI_DBCACHED;
9a490590
JH
2554 } else {
2555 oi->whence = OI_PACKED;
2556 oi->u.packed.offset = e.offset;
2557 oi->u.packed.pack = e.p;
2558 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2559 rtype == OBJ_OFS_DELTA);
3d77d877
NP
2560 }
2561
5b086407 2562 return 0;
f0df4ed5
JS
2563}
2564
3fc0dca9 2565/* returns enum object_type or negative */
9a490590
JH
2566int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2567{
5b086407 2568 enum object_type type;
d099b717 2569 struct object_info oi = {NULL};
9a490590 2570
5b086407 2571 oi.typep = &type;
9a490590 2572 oi.sizep = sizep;
de7b5d62 2573 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
5b086407
JK
2574 return -1;
2575 return type;
9a490590
JH
2576}
2577
21666f1a
NP
2578static void *read_packed_sha1(const unsigned char *sha1,
2579 enum object_type *type, unsigned long *size)
1f688557
JH
2580{
2581 struct pack_entry e;
8eca0b47 2582 void *data;
1f688557 2583
cd673c1f 2584 if (!find_pack_entry(sha1, &e))
1f688557 2585 return NULL;
8eca0b47
NP
2586 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2587 if (!data) {
2588 /*
2589 * We're probably in deep shit, but let's try to fetch
2590 * the required object anyway from another pack or loose.
2591 * This should happen only in the presence of a corrupted
2592 * pack, and is better than failing outright.
2593 */
2594 error("failed to read object %s at offset %"PRIuMAX" from %s",
2595 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2596 mark_bad_packed_object(e.p, sha1);
ac939109 2597 data = read_object(sha1, type, size);
8eca0b47
NP
2598 }
2599 return data;
1f688557
JH
2600}
2601
21666f1a
NP
2602int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2603 unsigned char *sha1)
d66b37bb
JH
2604{
2605 struct cached_object *co;
2606
21666f1a 2607 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2608 if (has_sha1_file(sha1) || find_cached_object(sha1))
2609 return 0;
2610 if (cached_object_alloc <= cached_object_nr) {
2611 cached_object_alloc = alloc_nr(cached_object_alloc);
2612 cached_objects = xrealloc(cached_objects,
2613 sizeof(*cached_objects) *
2614 cached_object_alloc);
2615 }
2616 co = &cached_objects[cached_object_nr++];
2617 co->size = len;
21666f1a 2618 co->type = type;
efa13f7b
JH
2619 co->buf = xmalloc(len);
2620 memcpy(co->buf, buf, len);
d66b37bb
JH
2621 hashcpy(co->sha1, sha1);
2622 return 0;
2623}
2624
c2c5b270
CC
2625static void *read_object(const unsigned char *sha1, enum object_type *type,
2626 unsigned long *size)
0fcfd160
LT
2627{
2628 unsigned long mapsize;
2629 void *map, *buf;
d66b37bb
JH
2630 struct cached_object *co;
2631
2632 co = find_cached_object(sha1);
2633 if (co) {
21666f1a 2634 *type = co->type;
d66b37bb 2635 *size = co->size;
182af834 2636 return xmemdupz(co->buf, co->size);
d66b37bb 2637 }
0fcfd160 2638
8276c007
PE
2639 buf = read_packed_sha1(sha1, type, size);
2640 if (buf)
2641 return buf;
bb6b8e4f 2642 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2643 if (map) {
7efbff75 2644 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2645 munmap(map, mapsize);
2646 return buf;
2647 }
637cdd9d 2648 reprepare_packed_git();
8276c007 2649 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2650}
2651
b6c4cecc
JH
2652/*
2653 * This function dies on corrupt objects; the callers who want to
2654 * deal with them should arrange to call read_object() and give error
2655 * messages themselves.
2656 */
5bf29b95
JH
2657void *read_sha1_file_extended(const unsigned char *sha1,
2658 enum object_type *type,
2659 unsigned long *size,
2660 unsigned flag)
ac939109 2661{
3ba7a065 2662 void *data;
e8b15e61 2663 char *path;
b6c4cecc 2664 const struct packed_git *p;
bf93eea0 2665 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
b6c4cecc 2666
3ba7a065
JH
2667 errno = 0;
2668 data = read_object(repl, type, size);
4bbf5a26 2669 if (data)
b6c4cecc 2670 return data;
68095570 2671
25f3af3f 2672 if (errno && errno != ENOENT)
3ba7a065
JH
2673 die_errno("failed to read object %s", sha1_to_hex(sha1));
2674
68095570 2675 /* die if we replaced an object with one that does not exist */
b6c4cecc 2676 if (repl != sha1)
68095570
CC
2677 die("replacement %s not found for %s",
2678 sha1_to_hex(repl), sha1_to_hex(sha1));
2679
b6c4cecc
JH
2680 if (has_loose_object(repl)) {
2681 path = sha1_file_name(sha1);
2682 die("loose object %s (stored in %s) is corrupt",
2683 sha1_to_hex(repl), path);
e8b15e61 2684 }
68095570 2685
b6c4cecc
JH
2686 if ((p = has_packed_and_bad(repl)) != NULL)
2687 die("packed object %s (stored in %s) is corrupt",
2688 sha1_to_hex(repl), p->pack_name);
f5552aee 2689
b6c4cecc 2690 return NULL;
ac939109
NP
2691}
2692
40469ee9 2693void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2694 const char *required_type_name,
40469ee9
JH
2695 unsigned long *size,
2696 unsigned char *actual_sha1_return)
f4913f91 2697{
21666f1a 2698 enum object_type type, required_type;
f4913f91
JH
2699 void *buffer;
2700 unsigned long isize;
40469ee9 2701 unsigned char actual_sha1[20];
f4913f91 2702
21666f1a 2703 required_type = type_from_string(required_type_name);
e702496e 2704 hashcpy(actual_sha1, sha1);
40469ee9
JH
2705 while (1) {
2706 int ref_length = -1;
2707 const char *ref_type = NULL;
f4913f91 2708
21666f1a 2709 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2710 if (!buffer)
2711 return NULL;
21666f1a 2712 if (type == required_type) {
40469ee9
JH
2713 *size = isize;
2714 if (actual_sha1_return)
e702496e 2715 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2716 return buffer;
2717 }
2718 /* Handle references */
21666f1a 2719 else if (type == OBJ_COMMIT)
40469ee9 2720 ref_type = "tree ";
21666f1a 2721 else if (type == OBJ_TAG)
40469ee9
JH
2722 ref_type = "object ";
2723 else {
2724 free(buffer);
2725 return NULL;
2726 }
2727 ref_length = strlen(ref_type);
f4913f91 2728
50974ec9
MK
2729 if (ref_length + 40 > isize ||
2730 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2731 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2732 free(buffer);
2733 return NULL;
2734 }
1cf58e72 2735 free(buffer);
40469ee9
JH
2736 /* Now we have the ID of the referred-to object in
2737 * actual_sha1. Check again. */
f4913f91 2738 }
f4913f91
JH
2739}
2740
ce9fbf16 2741static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2742 const char *type, unsigned char *sha1,
d65a16f6 2743 char *hdr, int *hdrlen)
d410c0f5 2744{
9126f009 2745 git_SHA_CTX c;
d410c0f5
JH
2746
2747 /* Generate the header */
d65a16f6 2748 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2749
2750 /* Sha1.. */
9126f009
NP
2751 git_SHA1_Init(&c);
2752 git_SHA1_Update(&c, hdr, *hdrlen);
2753 git_SHA1_Update(&c, buf, len);
2754 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2755}
2756
230f1322 2757/*
5a688fe4
JH
2758 * Move the just written object into its final resting place.
2759 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2760 * "moving" is only a part of what it does, when no patch between
2761 * master to pu changes the call sites of this function.
230f1322 2762 */
839837b9 2763int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2764{
e32c0a9c 2765 int ret = 0;
5a688fe4 2766
348df166 2767 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
2768 goto try_rename;
2769 else if (link(tmpfile, filename))
e32c0a9c 2770 ret = errno;
7ebb6fca
LT
2771
2772 /*
2773 * Coda hack - coda doesn't like cross-directory links,
2774 * so we fall back to a rename, which will mean that it
2775 * won't be able to check collisions, but that's not a
2776 * big deal.
2777 *
2778 * The same holds for FAT formatted media.
2779 *
3be1f18e 2780 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
2781 * left to unlink.
2782 */
2783 if (ret && ret != EEXIST) {
be66a6c4 2784 try_rename:
7ebb6fca 2785 if (!rename(tmpfile, filename))
3be1f18e 2786 goto out;
9e48b389 2787 ret = errno;
230f1322 2788 }
691f1a28 2789 unlink_or_warn(tmpfile);
230f1322
LT
2790 if (ret) {
2791 if (ret != EEXIST) {
82247e9b 2792 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
230f1322
LT
2793 }
2794 /* FIXME!!! Collision check here ? */
2795 }
2796
3be1f18e 2797out:
5256b006 2798 if (adjust_shared_perm(filename))
5a688fe4 2799 return error("unable to set permission to '%s'", filename);
230f1322
LT
2800 return 0;
2801}
2802
4d548150
LT
2803static int write_buffer(int fd, const void *buf, size_t len)
2804{
d34cf19b 2805 if (write_in_full(fd, buf, len) < 0)
93822c22 2806 return error("file write error (%s)", strerror(errno));
4d548150
LT
2807 return 0;
2808}
2809
ce9fbf16 2810int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2811 unsigned char *sha1)
2812{
d65a16f6 2813 char hdr[32];
abdc3fc8
RS
2814 int hdrlen;
2815 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2816 return 0;
2817}
2818
e9039dd3
LT
2819/* Finalize a file on disk, and close it. */
2820static void close_sha1_file(int fd)
2821{
aafe9fba
LT
2822 if (fsync_object_files)
2823 fsync_or_die(fd, "sha1 file");
e9039dd3 2824 if (close(fd) != 0)
d824cbba 2825 die_errno("error when closing sha1 file");
e9039dd3
LT
2826}
2827
5723fe7e
LT
2828/* Size of directory component, including the ending '/' */
2829static inline int directory_size(const char *filename)
2830{
2831 const char *s = strrchr(filename, '/');
2832 if (!s)
2833 return 0;
2834 return s - filename + 1;
2835}
2836
2837/*
2838 * This creates a temporary file in the same directory as the final
2839 * 'filename'
2840 *
2841 * We want to avoid cross-directory filename renames, because those
2842 * can have problems on various filesystems (FAT, NFS, Coda).
2843 */
2844static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2845{
2846 int fd, dirlen = directory_size(filename);
2847
2848 if (dirlen + 20 > bufsiz) {
2849 errno = ENAMETOOLONG;
2850 return -1;
2851 }
2852 memcpy(buffer, filename, dirlen);
2853 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
5256b006 2854 fd = git_mkstemp_mode(buffer, 0444);
cbacbf4e 2855 if (fd < 0 && dirlen && errno == ENOENT) {
5723fe7e 2856 /* Make sure the directory exists */
6ff6af62 2857 memcpy(buffer, filename, dirlen);
5723fe7e 2858 buffer[dirlen-1] = 0;
3bfaf018 2859 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2860 return -1;
2861
2862 /* Try again */
2863 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
5256b006 2864 fd = git_mkstemp_mode(buffer, 0444);
5723fe7e
LT
2865 }
2866 return fd;
2867}
2868
bbac7311 2869static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 2870 const void *buf, unsigned long len, time_t mtime)
0fcfd160 2871{
915308b1 2872 int fd, ret;
9892beba 2873 unsigned char compressed[4096];
ef49a7a0 2874 git_zstream stream;
748af44c
NP
2875 git_SHA_CTX c;
2876 unsigned char parano_sha1[20];
706bc531 2877 char *filename;
ab1900a3 2878 static char tmp_file[PATH_MAX];
a44c9a5e 2879
972a9155 2880 filename = sha1_file_name(sha1);
ab1900a3 2881 fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
aac17941 2882 if (fd < 0) {
35243577 2883 if (errno == EACCES)
82247e9b 2884 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 2885 else
5eaeda70 2886 return error("unable to create temporary file: %s", strerror(errno));
aac17941
LT
2887 }
2888
0fcfd160
LT
2889 /* Set it up */
2890 memset(&stream, 0, sizeof(stream));
55bb5c91 2891 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 2892 stream.next_out = compressed;
9892beba 2893 stream.avail_out = sizeof(compressed);
748af44c 2894 git_SHA1_Init(&c);
a44c9a5e
LT
2895
2896 /* First header.. */
d65a16f6 2897 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2898 stream.avail_in = hdrlen;
55bb5c91
JH
2899 while (git_deflate(&stream, 0) == Z_OK)
2900 ; /* nothing */
748af44c 2901 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
2902
2903 /* Then the data itself.. */
c00e657d 2904 stream.next_in = (void *)buf;
a44c9a5e 2905 stream.avail_in = len;
9892beba 2906 do {
748af44c 2907 unsigned char *in0 = stream.next_in;
55bb5c91 2908 ret = git_deflate(&stream, Z_FINISH);
748af44c 2909 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
2910 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2911 die("unable to write sha1 file");
2912 stream.next_out = compressed;
2913 stream.avail_out = sizeof(compressed);
2914 } while (ret == Z_OK);
2915
ac54c277
LT
2916 if (ret != Z_STREAM_END)
2917 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 2918 ret = git_deflate_end_gently(&stream);
ac54c277
LT
2919 if (ret != Z_OK)
2920 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
2921 git_SHA1_Final(parano_sha1, &c);
2922 if (hashcmp(sha1, parano_sha1) != 0)
2923 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 2924
e9039dd3 2925 close_sha1_file(fd);
0fcfd160 2926
bbac7311
NP
2927 if (mtime) {
2928 struct utimbuf utb;
2929 utb.actime = mtime;
2930 utb.modtime = mtime;
ab1900a3 2931 if (utime(tmp_file, &utb) < 0)
bbac7311 2932 warning("failed utime() on %s: %s",
ab1900a3 2933 tmp_file, strerror(errno));
bbac7311
NP
2934 }
2935
ab1900a3 2936 return move_temp_to_file(tmp_file, filename);
0fcfd160 2937}
8237b185 2938
c00e657d 2939int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
bbac7311
NP
2940{
2941 unsigned char sha1[20];
2942 char hdr[32];
2943 int hdrlen;
2944
2945 /* Normally if we have it in the pack then we do not bother writing
2946 * it out into .git/objects/??/?{38} file.
2947 */
2948 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2949 if (returnsha1)
2950 hashcpy(returnsha1, sha1);
2951 if (has_sha1_file(sha1))
2952 return 0;
2953 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2954}
2955
2956int force_object_loose(const unsigned char *sha1, time_t mtime)
2957{
bbac7311
NP
2958 void *buf;
2959 unsigned long len;
2960 enum object_type type;
2961 char hdr[32];
2962 int hdrlen;
1fb23e65 2963 int ret;
bbac7311 2964
c529d75a 2965 if (has_loose_object(sha1))
bbac7311
NP
2966 return 0;
2967 buf = read_packed_sha1(sha1, &type, &len);
2968 if (!buf)
2969 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2970 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1fb23e65
BS
2971 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2972 free(buf);
2973
2974 return ret;
bbac7311
NP
2975}
2976
bf592c50
DB
2977int has_pack_index(const unsigned char *sha1)
2978{
2979 struct stat st;
2980 if (stat(sha1_pack_index_name(sha1), &st))
2981 return 0;
2982 return 1;
bf592c50
DB
2983}
2984
cd673c1f
JH
2985int has_sha1_pack(const unsigned char *sha1)
2986{
2987 struct pack_entry e;
2988 return find_pack_entry(sha1, &e);
2989}
2990
8237b185
DB
2991int has_sha1_file(const unsigned char *sha1)
2992{
1f688557
JH
2993 struct pack_entry e;
2994
cd673c1f 2995 if (find_pack_entry(sha1, &e))
1f688557 2996 return 1;
45e8a748
JK
2997 if (has_loose_object(sha1))
2998 return 1;
2999 reprepare_packed_git();
3000 return find_pack_entry(sha1, &e);
8237b185 3001}
74400e71 3002
c879daa2
NTND
3003static void check_tree(const void *buf, size_t size)
3004{
3005 struct tree_desc desc;
3006 struct name_entry entry;
3007
3008 init_tree_desc(&desc, buf, size);
3009 while (tree_entry(&desc, &entry))
3010 /* do nothing
3011 * tree_entry() will die() on malformed entries */
3012 ;
3013}
3014
3015static void check_commit(const void *buf, size_t size)
3016{
3017 struct commit c;
3018 memset(&c, 0, sizeof(c));
3019 if (parse_commit_buffer(&c, buf, size))
3020 die("corrupt commit");
3021}
3022
3023static void check_tag(const void *buf, size_t size)
3024{
3025 struct tag t;
3026 memset(&t, 0, sizeof(t));
3027 if (parse_tag_buffer(&t, buf, size))
3028 die("corrupt tag");
3029}
3030
43df4f86 3031static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
3032 enum object_type type,
3033 const char *path, unsigned flags)
e7332f96 3034{
6c510bee 3035 int ret, re_allocated = 0;
c4ce46fc 3036 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 3037
7672db20 3038 if (!type)
edaec3fb 3039 type = OBJ_BLOB;
6c510bee
LT
3040
3041 /*
3042 * Convert blobs to git internal format
3043 */
43df4f86 3044 if ((type == OBJ_BLOB) && path) {
f285a2d7 3045 struct strbuf nbuf = STRBUF_INIT;
21e5ad50 3046 if (convert_to_git(path, buf, size, &nbuf,
5e12e78e 3047 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 3048 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
3049 re_allocated = 1;
3050 }
3051 }
c4ce46fc 3052 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
3053 if (type == OBJ_TREE)
3054 check_tree(buf, size);
3055 if (type == OBJ_COMMIT)
3056 check_commit(buf, size);
3057 if (type == OBJ_TAG)
3058 check_tag(buf, size);
3059 }
6c510bee 3060
7672db20 3061 if (write_object)
edaec3fb 3062 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 3063 else
edaec3fb 3064 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 3065 if (re_allocated)
6c510bee 3066 free(buf);
43df4f86
DP
3067 return ret;
3068}
3069
7b41e1e1
JH
3070static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3071 const char *path, unsigned flags)
3072{
3073 struct strbuf sbuf = STRBUF_INIT;
3074 int ret;
3075
3076 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3077 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3078 else
3079 ret = -1;
3080 strbuf_release(&sbuf);
3081 return ret;
3082}
3083
ea68b0ce
DP
3084#define SMALL_FILE_SIZE (32*1024)
3085
7b41e1e1
JH
3086static int index_core(unsigned char *sha1, int fd, size_t size,
3087 enum object_type type, const char *path,
3088 unsigned flags)
43df4f86
DP
3089{
3090 int ret;
43df4f86 3091
7b41e1e1 3092 if (!size) {
c4ce46fc 3093 ret = index_mem(sha1, NULL, size, type, path, flags);
ea68b0ce
DP
3094 } else if (size <= SMALL_FILE_SIZE) {
3095 char *buf = xmalloc(size);
3096 if (size == read_in_full(fd, buf, size))
c4ce46fc 3097 ret = index_mem(sha1, buf, size, type, path, flags);
ea68b0ce
DP
3098 else
3099 ret = error("short read %s", strerror(errno));
3100 free(buf);
08bda208 3101 } else {
43df4f86 3102 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
c4ce46fc 3103 ret = index_mem(sha1, buf, size, type, path, flags);
aac17941 3104 munmap(buf, size);
08bda208 3105 }
7b41e1e1
JH
3106 return ret;
3107}
3108
4dd1fbc7 3109/*
568508e7
JH
3110 * This creates one packfile per large blob unless bulk-checkin
3111 * machinery is "plugged".
4dd1fbc7
JH
3112 *
3113 * This also bypasses the usual "convert-to-git" dance, and that is on
3114 * purpose. We could write a streaming version of the converting
3115 * functions and insert that before feeding the data to fast-import
4f22b101
JK
3116 * (or equivalent in-core API described above). However, that is
3117 * somewhat complicated, as we do not know the size of the filter
3118 * result, which we need to know beforehand when writing a git object.
3119 * Since the primary motivation for trying to stream from the working
3120 * tree file and to avoid mmaping it in core is to deal with large
3121 * binary blobs, they generally do not want to get any conversion, and
3122 * callers should avoid this code path when filters are requested.
4dd1fbc7
JH
3123 */
3124static int index_stream(unsigned char *sha1, int fd, size_t size,
3125 enum object_type type, const char *path,
3126 unsigned flags)
3127{
568508e7 3128 return index_bulk_checkin(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
3129}
3130
7b41e1e1
JH
3131int index_fd(unsigned char *sha1, int fd, struct stat *st,
3132 enum object_type type, const char *path, unsigned flags)
3133{
3134 int ret;
3135 size_t size = xsize_t(st->st_size);
3136
3137 if (!S_ISREG(st->st_mode))
3138 ret = index_pipe(sha1, fd, type, path, flags);
4f22b101
JK
3139 else if (size <= big_file_threshold || type != OBJ_BLOB ||
3140 (path && would_convert_to_git(path, NULL, 0, 0)))
7b41e1e1 3141 ret = index_core(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
3142 else
3143 ret = index_stream(sha1, fd, size, type, path, flags);
43df4f86 3144 close(fd);
aac17941 3145 return ret;
74400e71 3146}
ec1fcc16 3147
c4ce46fc 3148int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
ec1fcc16
JH
3149{
3150 int fd;
b760d3aa 3151 struct strbuf sb = STRBUF_INIT;
ec1fcc16
JH
3152
3153 switch (st->st_mode & S_IFMT) {
3154 case S_IFREG:
3155 fd = open(path, O_RDONLY);
3156 if (fd < 0)
3157 return error("open(\"%s\"): %s", path,
3158 strerror(errno));
c4ce46fc 3159 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
ec1fcc16
JH
3160 return error("%s: failed to insert into database",
3161 path);
3162 break;
3163 case S_IFLNK:
b760d3aa 3164 if (strbuf_readlink(&sb, path, st->st_size)) {
ec1fcc16 3165 char *errstr = strerror(errno);
ec1fcc16
JH
3166 return error("readlink(\"%s\"): %s", path,
3167 errstr);
3168 }
c4ce46fc 3169 if (!(flags & HASH_WRITE_OBJECT))
b760d3aa
LT
3170 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3171 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
ec1fcc16
JH
3172 return error("%s: failed to insert into database",
3173 path);
b760d3aa 3174 strbuf_release(&sb);
ec1fcc16 3175 break;
f35a6d3b
LT
3176 case S_IFDIR:
3177 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
3178 default:
3179 return error("%s: unsupported file type", path);
3180 }
3181 return 0;
3182}
a69e5429
JH
3183
3184int read_pack_header(int fd, struct pack_header *header)
3185{
c697ad14
HO
3186 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3187 /* "eof before pack header was fully read" */
3188 return PH_ERROR_EOF;
3189
a69e5429
JH
3190 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3191 /* "protocol error (pack signature mismatch detected)" */
3192 return PH_ERROR_PACK_SIGNATURE;
3193 if (!pack_version_ok(header->hdr_version))
3194 /* "protocol error (pack version unsupported)" */
3195 return PH_ERROR_PROTOCOL;
3196 return 0;
3197}
40d52ff7
JK
3198
3199void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3200{
3201 enum object_type type = sha1_object_info(sha1, NULL);
3202 if (type < 0)
3203 die("%s is not a valid object", sha1_to_hex(sha1));
3204 if (type != expect)
3205 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3206 typename(expect));
3207}