Documentation/git.txt: improve documentation of 'GIT_TRACE*' variables
[git/git.git] / sha1_file.c
CommitLineData
0fcfd160
LT
1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
0fcfd160 9#include "cache.h"
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
1b1005d1
MH
63/*
64 * A pointer to the last packed_git in which an object was found.
65 * When an object is sought, we look in this packfile first, because
66 * objects that are looked up at similar times are often in the same
67 * packfile as one another.
68 */
c01f51cc
NTND
69static struct packed_git *last_found_pack;
70
c597ba80
NTND
71static struct cached_object *find_cached_object(const unsigned char *sha1)
72{
73 int i;
74 struct cached_object *co = cached_objects;
75
76 for (i = 0; i < cached_object_nr; i++, co++) {
77 if (!hashcmp(co->sha1, sha1))
78 return co;
79 }
80 if (!hashcmp(sha1, empty_tree.sha1))
81 return &empty_tree;
82 return NULL;
83}
84
90a6464b
JH
85int mkdir_in_gitdir(const char *path)
86{
87 if (mkdir(path, 0777)) {
88 int saved_errno = errno;
89 struct stat st;
90 struct strbuf sb = STRBUF_INIT;
91
92 if (errno != EEXIST)
93 return -1;
94 /*
95 * Are we looking at a path in a symlinked worktree
96 * whose original repository does not yet have it?
97 * e.g. .git/rr-cache pointing at its original
98 * repository in which the user hasn't performed any
99 * conflict resolution yet?
100 */
101 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
102 strbuf_readlink(&sb, path, st.st_size) ||
103 !is_absolute_path(sb.buf) ||
104 mkdir(sb.buf, 0777)) {
105 strbuf_release(&sb);
106 errno = saved_errno;
107 return -1;
108 }
109 strbuf_release(&sb);
110 }
111 return adjust_shared_perm(path);
112}
113
0be0521b 114enum scld_error safe_create_leading_directories(char *path)
b2cb9425 115{
26c8ae2a 116 char *next_component = path + offset_1st_component(path);
0be0521b 117 enum scld_error ret = SCLD_OK;
67d42212 118
0be0521b 119 while (ret == SCLD_OK && next_component) {
f0502332 120 struct stat st;
0f527403 121 char *slash = next_component, slash_character;
f0502332 122
0f527403
MH
123 while (*slash && !is_dir_sep(*slash))
124 slash++;
125
126 if (!*slash)
b2cb9425 127 break;
bf10cf70 128
26c8ae2a 129 next_component = slash + 1;
0f527403 130 while (is_dir_sep(*next_component))
bf10cf70 131 next_component++;
26c8ae2a 132 if (!*next_component)
5f0bdf50 133 break;
831651fd 134
0f527403 135 slash_character = *slash;
831651fd 136 *slash = '\0';
67d42212
JR
137 if (!stat(path, &st)) {
138 /* path exists */
9e6f885d 139 if (!S_ISDIR(st.st_mode))
0be0521b 140 ret = SCLD_EXISTS;
53a39721 141 } else if (mkdir(path, 0777)) {
928734d9 142 if (errno == EEXIST &&
9e6f885d 143 !stat(path, &st) && S_ISDIR(st.st_mode))
928734d9 144 ; /* somebody created it since we checked */
18d37e86
MH
145 else if (errno == ENOENT)
146 /*
147 * Either mkdir() failed because
148 * somebody just pruned the containing
149 * directory, or stat() failed because
150 * the file that was in our way was
151 * just removed. Either way, inform
152 * the caller that it might be worth
153 * trying again:
154 */
155 ret = SCLD_VANISHED;
9e6f885d 156 else
0be0521b 157 ret = SCLD_FAILED;
53a39721 158 } else if (adjust_shared_perm(path)) {
0be0521b 159 ret = SCLD_PERMS;
457f06d6 160 }
0f527403 161 *slash = slash_character;
b2cb9425 162 }
9e6f885d 163 return ret;
b2cb9425 164}
723c31fe 165
0be0521b 166enum scld_error safe_create_leading_directories_const(const char *path)
8e21d63b
JK
167{
168 /* path points to cache entries, so xstrdup before messing with it */
169 char *buf = xstrdup(path);
0be0521b 170 enum scld_error result = safe_create_leading_directories(buf);
8e21d63b
JK
171 free(buf);
172 return result;
173}
174
ace1534d
JH
175static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
176{
177 int i;
178 for (i = 0; i < 20; i++) {
179 static char hex[] = "0123456789abcdef";
180 unsigned int val = sha1[i];
181 char *pos = pathbuf + i*2 + (i > 0);
182 *pos++ = hex[val >> 4];
183 *pos = hex[val & 0xf];
184 }
185}
186
30d6c6ea 187const char *sha1_file_name(const unsigned char *sha1)
0fcfd160 188{
560fb6a1
JK
189 static char buf[PATH_MAX];
190 const char *objdir;
191 int len;
0fcfd160 192
560fb6a1
JK
193 objdir = get_object_directory();
194 len = strlen(objdir);
195
196 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
197 if (len + 43 > PATH_MAX)
198 die("insanely long object directory %s", objdir);
199 memcpy(buf, objdir, len);
200 buf[len] = '/';
201 buf[len+3] = '/';
202 buf[len+42] = '\0';
203 fill_sha1_path(buf + len + 1, sha1);
204 return buf;
0fcfd160
LT
205}
206
d40d535b
MH
207/*
208 * Return the name of the pack or index file with the specified sha1
209 * in its filename. *base and *name are scratch space that must be
210 * provided by the caller. which should be "pack" or "idx".
211 */
633f43e1 212static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 213 char **name, char **base, const char *which)
bf592c50
DB
214{
215 static const char hex[] = "0123456789abcdef";
633f43e1 216 char *buf;
bf592c50
DB
217 int i;
218
633f43e1 219 if (!*base) {
bf592c50
DB
220 const char *sha1_file_directory = get_object_directory();
221 int len = strlen(sha1_file_directory);
633f43e1 222 *base = xmalloc(len + 60);
6eec46bd
JH
223 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
224 sha1_file_directory, which);
633f43e1 225 *name = *base + len + 11;
bf592c50
DB
226 }
227
633f43e1 228 buf = *name;
bf592c50
DB
229
230 for (i = 0; i < 20; i++) {
231 unsigned int val = *sha1++;
232 *buf++ = hex[val >> 4];
233 *buf++ = hex[val & 0xf];
234 }
a6080a0a 235
633f43e1 236 return *base;
bf592c50
DB
237}
238
633f43e1 239char *sha1_pack_name(const unsigned char *sha1)
bf592c50 240{
633f43e1 241 static char *name, *base;
bf592c50 242
6eec46bd 243 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 244}
bf592c50 245
633f43e1
HO
246char *sha1_pack_index_name(const unsigned char *sha1)
247{
248 static char *name, *base;
a6080a0a 249
6eec46bd 250 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
251}
252
d5a63b99
JH
253struct alternate_object_database *alt_odb_list;
254static struct alternate_object_database **alt_odb_tail;
ace1534d 255
ddd5d056
JH
256/*
257 * Prepare alternate object database registry.
d5a63b99
JH
258 *
259 * The variable alt_odb_list points at the list of struct
260 * alternate_object_database. The elements on this list come from
261 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
262 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
263 * whose contents is similar to that environment variable but can be
264 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
265 * contains "/the/directory/corresponding/to/.git/objects/...", while
266 * its name points just after the slash at the end of ".git/objects/"
267 * in the example above, and has enough space to hold 40-byte hex
268 * SHA1, an extra slash for the first level indirection, and the
269 * terminating NUL.
ddd5d056 270 */
6eac50d8 271static int link_alt_odb_entry(const char *entry, const char *relative_base, int depth)
ace1534d 272{
1494e038 273 const char *objdir = get_object_directory();
c2f493a4
MW
274 struct alternate_object_database *ent;
275 struct alternate_object_database *alt;
5bdf0a84
HW
276 int pfxlen, entlen;
277 struct strbuf pathbuf = STRBUF_INIT;
d5a63b99 278
85dadc38 279 if (!is_absolute_path(entry) && relative_base) {
5bdf0a84
HW
280 strbuf_addstr(&pathbuf, real_path(relative_base));
281 strbuf_addch(&pathbuf, '/');
c2f493a4 282 }
6eac50d8 283 strbuf_addstr(&pathbuf, entry);
c2f493a4 284
5bdf0a84
HW
285 normalize_path_copy(pathbuf.buf, pathbuf.buf);
286
287 pfxlen = strlen(pathbuf.buf);
288
289 /*
290 * The trailing slash after the directory name is given by
291 * this function at the end. Remove duplicates.
292 */
293 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
294 pfxlen -= 1;
295
296 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
297 ent = xmalloc(sizeof(*ent) + entlen);
298 memcpy(ent->base, pathbuf.buf, pfxlen);
299 strbuf_release(&pathbuf);
c2f493a4
MW
300
301 ent->name = ent->base + pfxlen + 1;
302 ent->base[pfxlen + 3] = '/';
303 ent->base[pfxlen] = ent->base[entlen-1] = 0;
304
305 /* Detect cases where alternate disappeared */
90b4a71c 306 if (!is_directory(ent->base)) {
c2f493a4
MW
307 error("object directory %s does not exist; "
308 "check .git/objects/info/alternates.",
309 ent->base);
310 free(ent);
311 return -1;
312 }
313
314 /* Prevent the common mistake of listing the same
315 * thing twice, or object directory itself.
316 */
317 for (alt = alt_odb_list; alt; alt = alt->next) {
318 if (!memcmp(ent->base, alt->base, pfxlen)) {
319 free(ent);
320 return -1;
321 }
322 }
cb2912c3 323 if (!strcmp(ent->base, objdir)) {
c2f493a4
MW
324 free(ent);
325 return -1;
326 }
327
328 /* add the alternate entry */
329 *alt_odb_tail = ent;
330 alt_odb_tail = &(ent->next);
331 ent->next = NULL;
332
333 /* recursively add alternates */
334 read_info_alternates(ent->base, depth + 1);
335
336 ent->base[pfxlen] = '/';
337
338 return 0;
339}
340
c5950164 341static void link_alt_odb_entries(const char *alt, int len, int sep,
c2f493a4
MW
342 const char *relative_base, int depth)
343{
6eac50d8
MH
344 struct string_list entries = STRING_LIST_INIT_NODUP;
345 char *alt_copy;
346 int i;
c2f493a4
MW
347
348 if (depth > 5) {
349 error("%s: ignoring alternate object stores, nesting too deep.",
350 relative_base);
351 return;
352 }
353
c5950164 354 alt_copy = xmemdupz(alt, len);
6eac50d8
MH
355 string_list_split_in_place(&entries, alt_copy, sep, -1);
356 for (i = 0; i < entries.nr; i++) {
357 const char *entry = entries.items[i].string;
358 if (entry[0] == '\0' || entry[0] == '#')
9577e7e3 359 continue;
6eac50d8
MH
360 if (!is_absolute_path(entry) && depth) {
361 error("%s: ignoring relative alternate object store %s",
362 relative_base, entry);
363 } else {
364 link_alt_odb_entry(entry, relative_base, depth);
9577e7e3 365 }
9577e7e3 366 }
6eac50d8
MH
367 string_list_clear(&entries, 0);
368 free(alt_copy);
d5a63b99
JH
369}
370
5e73633d 371void read_info_alternates(const char * relative_base, int depth)
d5a63b99 372{
9577e7e3 373 char *map;
dc49cd76 374 size_t mapsz;
d5a63b99 375 struct stat st;
9cb18f56
JM
376 const char alt_file_name[] = "info/alternates";
377 /* Given that relative_base is no longer than PATH_MAX,
378 ensure that "path" has enough space to append "/", the
379 file name, "info/alternates", and a trailing NUL. */
380 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 381 int fd;
d5a63b99 382
9cb18f56 383 sprintf(path, "%s/%s", relative_base, alt_file_name);
f4e51683 384 fd = git_open_noatime(path);
d5a63b99
JH
385 if (fd < 0)
386 return;
387 if (fstat(fd, &st) || (st.st_size == 0)) {
388 close(fd);
9a217f2a 389 return;
ace1534d 390 }
dc49cd76
SP
391 mapsz = xsize_t(st.st_size);
392 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 393 close(fd);
d5a63b99 394
c5950164 395 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
c2f493a4 396
dc49cd76 397 munmap(map, mapsz);
ace1534d
JH
398}
399
bef70b22
DB
400void add_to_alternates_file(const char *reference)
401{
402 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
acd3b9ec 403 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
e6baf4a1 404 char *alt = mkpath("%s\n", reference);
bef70b22
DB
405 write_or_die(fd, alt, strlen(alt));
406 if (commit_lock_file(lock))
407 die("could not close alternates file");
408 if (alt_odb_tail)
c5950164 409 link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
bef70b22
DB
410}
411
d79796bc
JH
412void foreach_alt_odb(alt_odb_fn fn, void *cb)
413{
414 struct alternate_object_database *ent;
415
416 prepare_alt_odb();
417 for (ent = alt_odb_list; ent; ent = ent->next)
418 if (fn(ent, cb))
419 return;
420}
421
c2f493a4
MW
422void prepare_alt_odb(void)
423{
554fe20d 424 const char *alt;
c2f493a4 425
7dc24aa5
SP
426 if (alt_odb_tail)
427 return;
428
c2f493a4
MW
429 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
430 if (!alt) alt = "";
431
c2f493a4 432 alt_odb_tail = &alt_odb_list;
c5950164 433 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
434
435 read_info_alternates(get_object_directory(), 0);
436}
437
0f4dc14a 438static int has_loose_object_local(const unsigned char *sha1)
ace1534d 439{
30d6c6ea 440 return !access(sha1_file_name(sha1), F_OK);
0f4dc14a 441}
ace1534d 442
0f4dc14a
BC
443int has_loose_object_nonlocal(const unsigned char *sha1)
444{
445 struct alternate_object_database *alt;
9a217f2a 446 prepare_alt_odb();
d5a63b99 447 for (alt = alt_odb_list; alt; alt = alt->next) {
0f4dc14a 448 fill_sha1_path(alt->name, sha1);
c529d75a
LT
449 if (!access(alt->base, F_OK))
450 return 1;
ace1534d 451 }
c529d75a 452 return 0;
ace1534d
JH
453}
454
0f4dc14a
BC
455static int has_loose_object(const unsigned char *sha1)
456{
457 return has_loose_object_local(sha1) ||
458 has_loose_object_nonlocal(sha1);
459}
460
60bb8b14 461static unsigned int pack_used_ctr;
a53128b6
SP
462static unsigned int pack_mmap_calls;
463static unsigned int peak_pack_open_windows;
464static unsigned int pack_open_windows;
c7934306
SP
465static unsigned int pack_open_fds;
466static unsigned int pack_max_fds;
a53128b6 467static size_t peak_pack_mapped;
60bb8b14 468static size_t pack_mapped;
9a217f2a 469struct packed_git *packed_git;
1f688557 470
b79d18c9 471void pack_report(void)
a53128b6
SP
472{
473 fprintf(stderr,
e05db0fd
PR
474 "pack_report: getpagesize() = %10" SZ_FMT "\n"
475 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
476 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
477 sz_fmt(getpagesize()),
478 sz_fmt(packed_git_window_size),
479 sz_fmt(packed_git_limit));
a53128b6
SP
480 fprintf(stderr,
481 "pack_report: pack_used_ctr = %10u\n"
482 "pack_report: pack_mmap_calls = %10u\n"
483 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
484 "pack_report: pack_mapped = "
485 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
486 pack_used_ctr,
487 pack_mmap_calls,
488 pack_open_windows, peak_pack_open_windows,
9e42d6a1 489 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
490}
491
d40d535b
MH
492/*
493 * Open and mmap the index file at path, perform a couple of
494 * consistency checks, then record its information to p. Return 0 on
495 * success.
496 */
497static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
498{
499 void *idx_map;
42873078 500 struct pack_idx_header *hdr;
dc49cd76 501 size_t idx_size;
74e34e1f 502 uint32_t version, nr, i, *index;
f4e51683 503 int fd = git_open_noatime(path);
1f688557 504 struct stat st;
42873078 505
1f688557
JH
506 if (fd < 0)
507 return -1;
508 if (fstat(fd, &st)) {
509 close(fd);
510 return -1;
511 }
dc49cd76 512 idx_size = xsize_t(st.st_size);
2d88451b
SP
513 if (idx_size < 4 * 256 + 20 + 20) {
514 close(fd);
515 return error("index file %s is too small", path);
516 }
c4712e45 517 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 518 close(fd);
1f688557 519
42873078
NP
520 hdr = idx_map;
521 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
522 version = ntohl(hdr->idx_version);
523 if (version < 2 || version > 2) {
524 munmap(idx_map, idx_size);
6e1c2344 525 return error("index file %s is version %"PRIu32
74e34e1f
NP
526 " and is not supported by this binary"
527 " (try upgrading GIT to a newer version)",
528 path, version);
529 }
530 } else
531 version = 1;
df1b059d 532
1f688557 533 nr = 0;
42873078 534 index = idx_map;
74e34e1f
NP
535 if (version > 1)
536 index += 2; /* skip index header */
1f688557 537 for (i = 0; i < 256; i++) {
326bf396 538 uint32_t n = ntohl(index[i]);
2d88451b
SP
539 if (n < nr) {
540 munmap(idx_map, idx_size);
df1b059d 541 return error("non-monotonic index %s", path);
2d88451b 542 }
1f688557
JH
543 nr = n;
544 }
545
74e34e1f
NP
546 if (version == 1) {
547 /*
548 * Total size:
549 * - 256 index entries 4 bytes each
550 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
551 * - 20-byte SHA1 of the packfile
552 * - 20-byte SHA1 file checksum
553 */
554 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
555 munmap(idx_map, idx_size);
eef427a0 556 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
557 }
558 } else if (version == 2) {
559 /*
560 * Minimum size:
561 * - 8 bytes of header
562 * - 256 index entries 4 bytes each
563 * - 20-byte sha1 entry * nr
564 * - 4-byte crc entry * nr
565 * - 4-byte offset entry * nr
566 * - 20-byte SHA1 of the packfile
567 * - 20-byte SHA1 file checksum
568 * And after the 4-byte offset table might be a
569 * variable sized table containing 8-byte entries
570 * for offsets larger than 2^31.
571 */
572 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
573 unsigned long max_size = min_size;
574 if (nr)
575 max_size += (nr - 1)*8;
576 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 577 munmap(idx_map, idx_size);
eef427a0 578 return error("wrong index v2 file size in %s", path);
74e34e1f 579 }
7109c889
JH
580 if (idx_size != min_size &&
581 /*
582 * make sure we can deal with large pack offsets.
583 * 31-bit signed offset won't be enough, neither
584 * 32-bit unsigned one will be.
585 */
586 (sizeof(off_t) <= 4)) {
587 munmap(idx_map, idx_size);
588 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 589 }
2d88451b 590 }
1f688557 591
74e34e1f 592 p->index_version = version;
42873078
NP
593 p->index_data = idx_map;
594 p->index_size = idx_size;
57059091 595 p->num_objects = nr;
1f688557
JH
596 return 0;
597}
598
bc8e478a 599int open_pack_index(struct packed_git *p)
d079837e
SP
600{
601 char *idx_name;
602 int ret;
603
604 if (p->index_data)
605 return 0;
606
607 idx_name = xstrdup(p->pack_name);
608 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
609 ret = check_packed_git_idx(idx_name, p);
610 free(idx_name);
611 return ret;
612}
613
11daf39b
SP
614static void scan_windows(struct packed_git *p,
615 struct packed_git **lru_p,
616 struct pack_window **lru_w,
617 struct pack_window **lru_l)
1f688557 618{
11daf39b
SP
619 struct pack_window *w, *w_l;
620
621 for (w_l = NULL, w = p->windows; w; w = w->next) {
622 if (!w->inuse_cnt) {
623 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
624 *lru_p = p;
625 *lru_w = w;
626 *lru_l = w_l;
54044bf8 627 }
54044bf8 628 }
11daf39b 629 w_l = w;
f9253394 630 }
11daf39b
SP
631}
632
7c3ecb32 633static int unuse_one_window(struct packed_git *current)
11daf39b
SP
634{
635 struct packed_git *p, *lru_p = NULL;
636 struct pack_window *lru_w = NULL, *lru_l = NULL;
637
638 if (current)
639 scan_windows(current, &lru_p, &lru_w, &lru_l);
640 for (p = packed_git; p; p = p->next)
641 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
642 if (lru_p) {
643 munmap(lru_w->base, lru_w->len);
644 pack_mapped -= lru_w->len;
645 if (lru_l)
646 lru_l->next = lru_w->next;
7c3ecb32 647 else
54044bf8 648 lru_p->windows = lru_w->next;
54044bf8 649 free(lru_w);
a53128b6 650 pack_open_windows--;
54044bf8
SP
651 return 1;
652 }
653 return 0;
f9253394
JH
654}
655
7c3ecb32 656void release_pack_memory(size_t need)
97bfeb34
SP
657{
658 size_t cur = pack_mapped;
7c3ecb32 659 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
97bfeb34
SP
660 ; /* nothing */
661}
662
58ecbd5e
JN
663void *xmmap(void *start, size_t length,
664 int prot, int flags, int fd, off_t offset)
665{
666 void *ret = mmap(start, length, prot, flags, fd, offset);
667 if (ret == MAP_FAILED) {
668 if (!length)
669 return NULL;
7c3ecb32 670 release_pack_memory(length);
58ecbd5e
JN
671 ret = mmap(start, length, prot, flags, fd, offset);
672 if (ret == MAP_FAILED)
673 die_errno("Out of memory? mmap failed");
674 }
675 return ret;
676}
677
c9ced051
SP
678void close_pack_windows(struct packed_git *p)
679{
680 while (p->windows) {
681 struct pack_window *w = p->windows;
682
683 if (w->inuse_cnt)
684 die("pack '%s' still has open windows to it",
685 p->pack_name);
686 munmap(w->base, w->len);
687 pack_mapped -= w->len;
688 pack_open_windows--;
689 p->windows = w->next;
690 free(w);
691 }
692}
693
88d0db55
BC
694/*
695 * The LRU pack is the one with the oldest MRU window, preferring packs
696 * with no used windows, or the oldest mtime if it has no windows allocated.
697 */
698static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
699{
700 struct pack_window *w, *this_mru_w;
701 int has_windows_inuse = 0;
702
703 /*
704 * Reject this pack if it has windows and the previously selected
705 * one does not. If this pack does not have windows, reject
706 * it if the pack file is newer than the previously selected one.
707 */
708 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
709 return;
710
711 for (w = this_mru_w = p->windows; w; w = w->next) {
712 /*
713 * Reject this pack if any of its windows are in use,
714 * but the previously selected pack did not have any
715 * inuse windows. Otherwise, record that this pack
716 * has windows in use.
717 */
718 if (w->inuse_cnt) {
719 if (*accept_windows_inuse)
720 has_windows_inuse = 1;
721 else
722 return;
723 }
724
725 if (w->last_used > this_mru_w->last_used)
726 this_mru_w = w;
727
728 /*
729 * Reject this pack if it has windows that have been
730 * used more recently than the previously selected pack.
731 * If the previously selected pack had windows inuse and
732 * we have not encountered a window in this pack that is
733 * inuse, skip this check since we prefer a pack with no
734 * inuse windows to one that has inuse windows.
735 */
736 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
737 this_mru_w->last_used > (*mru_w)->last_used)
738 return;
739 }
740
741 /*
742 * Select this pack.
743 */
744 *mru_w = this_mru_w;
745 *lru_p = p;
746 *accept_windows_inuse = has_windows_inuse;
747}
748
749static int close_one_pack(void)
750{
751 struct packed_git *p, *lru_p = NULL;
752 struct pack_window *mru_w = NULL;
753 int accept_windows_inuse = 1;
754
755 for (p = packed_git; p; p = p->next) {
756 if (p->pack_fd == -1)
757 continue;
758 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
759 }
760
761 if (lru_p) {
762 close(lru_p->pack_fd);
763 pack_open_fds--;
764 lru_p->pack_fd = -1;
765 return 1;
766 }
767
768 return 0;
769}
770
03e79c88 771void unuse_pack(struct pack_window **w_cursor)
f9253394 772{
03e79c88
SP
773 struct pack_window *w = *w_cursor;
774 if (w) {
775 w->inuse_cnt--;
776 *w_cursor = NULL;
777 }
1f688557
JH
778}
779
fa5fc15d
SP
780void close_pack_index(struct packed_git *p)
781{
782 if (p->index_data) {
783 munmap((void *)p->index_data, p->index_size);
784 p->index_data = NULL;
785 }
786}
787
c74faea1
NP
788/*
789 * This is used by git-repack in case a newly created pack happens to
790 * contain the same set of objects as an existing one. In that case
791 * the resulting file might be different even if its name would be the
792 * same. It is best to close any reference to the old pack before it is
01689909 793 * replaced on disk. Of course no index pointers or windows for given pack
c74faea1
NP
794 * must subsist at this point. If ever objects from this pack are requested
795 * again, the new version of the pack will be reinitialized through
796 * reprepare_packed_git().
797 */
798void free_pack_by_name(const char *pack_name)
799{
800 struct packed_git *p, **pp = &packed_git;
801
802 while (*pp) {
803 p = *pp;
804 if (strcmp(pack_name, p->pack_name) == 0) {
fa3a0c94 805 clear_delta_base_cache();
c74faea1 806 close_pack_windows(p);
c7934306 807 if (p->pack_fd != -1) {
c74faea1 808 close(p->pack_fd);
c7934306
SP
809 pack_open_fds--;
810 }
fa5fc15d 811 close_pack_index(p);
c74faea1
NP
812 free(p->bad_object_sha1);
813 *pp = p->next;
c01f51cc
NTND
814 if (last_found_pack == p)
815 last_found_pack = NULL;
c74faea1
NP
816 free(p);
817 return;
818 }
819 pp = &p->next;
820 }
821}
822
a0788266
JS
823static unsigned int get_max_fd_limit(void)
824{
825#ifdef RLIMIT_NOFILE
491a8dec
JH
826 {
827 struct rlimit lim;
a0788266 828
491a8dec
JH
829 if (!getrlimit(RLIMIT_NOFILE, &lim))
830 return lim.rlim_cur;
831 }
832#endif
833
834#ifdef _SC_OPEN_MAX
835 {
836 long open_max = sysconf(_SC_OPEN_MAX);
837 if (0 < open_max)
838 return open_max;
839 /*
840 * Otherwise, we got -1 for one of the two
841 * reasons:
842 *
843 * (1) sysconf() did not understand _SC_OPEN_MAX
844 * and signaled an error with -1; or
845 * (2) sysconf() said there is no limit.
846 *
847 * We _could_ clear errno before calling sysconf() to
848 * tell these two cases apart and return a huge number
849 * in the latter case to let the caller cap it to a
850 * value that is not so selfish, but letting the
851 * fallback OPEN_MAX codepath take care of these cases
852 * is a lot simpler.
853 */
854 }
855#endif
a0788266 856
491a8dec 857#ifdef OPEN_MAX
a0788266
JS
858 return OPEN_MAX;
859#else
860 return 1; /* see the caller ;-) */
861#endif
862}
863
3cf8b462
SP
864/*
865 * Do not call this directly as this leaks p->pack_fd on error return;
866 * call open_packed_git() instead.
867 */
868static int open_packed_git_1(struct packed_git *p)
1f688557 869{
9bc879c1
SP
870 struct stat st;
871 struct pack_header hdr;
872 unsigned char sha1[20];
873 unsigned char *idx_sha1;
2c039da8 874 long fd_flag;
9bc879c1 875
d079837e
SP
876 if (!p->index_data && open_pack_index(p))
877 return error("packfile %s index unavailable", p->pack_name);
878
c7934306 879 if (!pack_max_fds) {
a0788266 880 unsigned int max_fds = get_max_fd_limit();
c7934306
SP
881
882 /* Save 3 for stdin/stdout/stderr, 22 for work */
883 if (25 < max_fds)
884 pack_max_fds = max_fds - 25;
885 else
886 pack_max_fds = 1;
887 }
888
88d0db55 889 while (pack_max_fds <= pack_open_fds && close_one_pack())
c7934306
SP
890 ; /* nothing */
891
f4e51683 892 p->pack_fd = git_open_noatime(p->pack_name);
9bc879c1 893 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 894 return -1;
c7934306 895 pack_open_fds++;
9bc879c1
SP
896
897 /* If we created the struct before we had the pack we lack size. */
bf592c50 898 if (!p->pack_size) {
bf592c50 899 if (!S_ISREG(st.st_mode))
072db278 900 return error("packfile %s not a regular file", p->pack_name);
bf592c50 901 p->pack_size = st.st_size;
9bc879c1 902 } else if (p->pack_size != st.st_size)
072db278 903 return error("packfile %s size changed", p->pack_name);
9bc879c1 904
2c039da8
JH
905 /* We leave these file descriptors open with sliding mmap;
906 * there is no point keeping them open across exec(), though.
907 */
908 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
909 if (fd_flag < 0)
072db278 910 return error("cannot determine file descriptor flags");
2c039da8
JH
911 fd_flag |= FD_CLOEXEC;
912 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 913 return error("cannot set FD_CLOEXEC");
2c039da8 914
9bc879c1 915 /* Verify we recognize this pack file format. */
e6e2bd62 916 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 917 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 918 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 919 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 920 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
921 return error("packfile %s is version %"PRIu32" and not"
922 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
923 p->pack_name, ntohl(hdr.hdr_version));
924
925 /* Verify the pack matches its index. */
57059091 926 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
927 return error("packfile %s claims to have %"PRIu32" objects"
928 " while index indicates %"PRIu32" objects",
57059091
NP
929 p->pack_name, ntohl(hdr.hdr_entries),
930 p->num_objects);
9bc879c1 931 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 932 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 933 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 934 return error("packfile %s signature is unavailable", p->pack_name);
42873078 935 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 936 if (hashcmp(sha1, idx_sha1))
072db278
SP
937 return error("packfile %s does not match index", p->pack_name);
938 return 0;
9bc879c1
SP
939}
940
3cf8b462
SP
941static int open_packed_git(struct packed_git *p)
942{
943 if (!open_packed_git_1(p))
944 return 0;
945 if (p->pack_fd != -1) {
946 close(p->pack_fd);
c7934306 947 pack_open_fds--;
3cf8b462
SP
948 p->pack_fd = -1;
949 }
950 return -1;
951}
952
c4001d92 953static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
954{
955 /* We must promise at least 20 bytes (one hash) after the
956 * offset is available from this window, otherwise the offset
957 * is not actually in this window and a different window (which
958 * has that one hash excess) must be used. This is to support
959 * the object header and delta base parsing routines below.
960 */
961 off_t win_off = win->offset;
962 return win_off <= offset
963 && (offset + 20) <= (win_off + win->len);
964}
965
4b25d091 966unsigned char *use_pack(struct packed_git *p,
03e79c88 967 struct pack_window **w_cursor,
c4001d92 968 off_t offset,
ef49a7a0 969 unsigned long *left)
9bc879c1 970{
60bb8b14 971 struct pack_window *win = *w_cursor;
03e79c88 972
a9d98a14 973 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
974 * pointless to ask for an offset into the middle of that
975 * hash, and the in_window function above wouldn't match
976 * don't allow an offset too close to the end of the file.
977 */
d131b7af
SP
978 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
979 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
980 if (offset > (p->pack_size - 20))
981 die("offset beyond end of packfile (truncated pack?)");
982
983 if (!win || !in_window(win, offset)) {
984 if (win)
985 win->inuse_cnt--;
986 for (win = p->windows; win; win = win->next) {
987 if (in_window(win, offset))
988 break;
989 }
990 if (!win) {
78a28df9 991 size_t window_align = packed_git_window_size / 2;
dc49cd76 992 off_t len;
d131b7af
SP
993
994 if (p->pack_fd == -1 && open_packed_git(p))
995 die("packfile %s cannot be accessed", p->pack_name);
996
60bb8b14 997 win = xcalloc(1, sizeof(*win));
78a28df9 998 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
999 len = p->pack_size - win->offset;
1000 if (len > packed_git_window_size)
1001 len = packed_git_window_size;
1002 win->len = (size_t)len;
60bb8b14 1003 pack_mapped += win->len;
11daf39b 1004 while (packed_git_limit < pack_mapped
7c3ecb32 1005 && unuse_one_window(p))
60bb8b14 1006 ; /* nothing */
c4712e45 1007 win->base = xmmap(NULL, win->len,
60bb8b14
SP
1008 PROT_READ, MAP_PRIVATE,
1009 p->pack_fd, win->offset);
1010 if (win->base == MAP_FAILED)
73b4e4be
SP
1011 die("packfile %s cannot be mapped: %s",
1012 p->pack_name,
1013 strerror(errno));
d131b7af
SP
1014 if (!win->offset && win->len == p->pack_size
1015 && !p->do_not_close) {
1016 close(p->pack_fd);
1017 pack_open_fds--;
1018 p->pack_fd = -1;
1019 }
a53128b6
SP
1020 pack_mmap_calls++;
1021 pack_open_windows++;
1022 if (pack_mapped > peak_pack_mapped)
1023 peak_pack_mapped = pack_mapped;
1024 if (pack_open_windows > peak_pack_open_windows)
1025 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
1026 win->next = p->windows;
1027 p->windows = win;
1028 }
1f688557 1029 }
03e79c88
SP
1030 if (win != *w_cursor) {
1031 win->last_used = pack_used_ctr++;
1032 win->inuse_cnt++;
1033 *w_cursor = win;
1034 }
60bb8b14 1035 offset -= win->offset;
03e79c88 1036 if (left)
dc49cd76 1037 *left = win->len - xsize_t(offset);
03e79c88 1038 return win->base + offset;
1f688557
JH
1039}
1040
27d69a46
NP
1041static struct packed_git *alloc_packed_git(int extra)
1042{
1043 struct packed_git *p = xmalloc(sizeof(*p) + extra);
1044 memset(p, 0, sizeof(*p));
1045 p->pack_fd = -1;
1046 return p;
1047}
1048
e0500293
JN
1049static void try_to_free_pack_memory(size_t size)
1050{
7c3ecb32 1051 release_pack_memory(size);
e0500293
JN
1052}
1053
42873078 1054struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557 1055{
e0500293 1056 static int have_set_try_to_free_routine;
1f688557 1057 struct stat st;
27d69a46 1058 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 1059
e0500293
JN
1060 if (!have_set_try_to_free_routine) {
1061 have_set_try_to_free_routine = 1;
1062 set_try_to_free_routine(try_to_free_pack_memory);
1063 }
1064
42873078
NP
1065 /*
1066 * Make sure a corresponding .pack file exists and that
1067 * the index looks sane.
1068 */
1069 path_len -= strlen(".idx");
27d69a46
NP
1070 if (path_len < 1) {
1071 free(p);
1f688557 1072 return NULL;
27d69a46 1073 }
42873078 1074 memcpy(p->pack_name, path, path_len);
8d25931d
BC
1075
1076 strcpy(p->pack_name + path_len, ".keep");
1077 if (!access(p->pack_name, F_OK))
1078 p->pack_keep = 1;
1079
42873078 1080 strcpy(p->pack_name + path_len, ".pack");
d079837e 1081 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 1082 free(p);
1f688557
JH
1083 return NULL;
1084 }
42873078 1085
1f688557
JH
1086 /* ok, it looks sane as far as we can check without
1087 * actually mapping the pack file.
1088 */
1f688557 1089 p->pack_size = st.st_size;
9d835df2 1090 p->pack_local = local;
b867092f 1091 p->mtime = st.st_mtime;
42873078
NP
1092 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1093 hashclr(p->sha1);
1f688557
JH
1094 return p;
1095}
1096
7b64469a 1097struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 1098{
42873078 1099 const char *path = sha1_pack_name(sha1);
27d69a46 1100 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 1101
27d69a46
NP
1102 strcpy(p->pack_name, path);
1103 hashcpy(p->sha1, sha1);
42873078
NP
1104 if (check_packed_git_idx(idx_path, p)) {
1105 free(p);
bf592c50 1106 return NULL;
42873078 1107 }
bf592c50 1108
bf592c50
DB
1109 return p;
1110}
1111
1112void install_packed_git(struct packed_git *pack)
1113{
c7934306
SP
1114 if (pack->pack_fd != -1)
1115 pack_open_fds++;
1116
bf592c50
DB
1117 pack->next = packed_git;
1118 packed_git = pack;
1119}
1120
543c5caa
NTND
1121void (*report_garbage)(const char *desc, const char *path);
1122
1123static void report_helper(const struct string_list *list,
1124 int seen_bits, int first, int last)
1125{
1126 const char *msg;
1127 switch (seen_bits) {
1128 case 0:
235e8d59 1129 msg = "no corresponding .idx or .pack";
543c5caa
NTND
1130 break;
1131 case 1:
1132 msg = "no corresponding .idx";
1133 break;
1134 case 2:
1135 msg = "no corresponding .pack";
1136 break;
1137 default:
1138 return;
1139 }
1140 for (; first < last; first++)
1141 report_garbage(msg, list->items[first].string);
1142}
1143
1144static void report_pack_garbage(struct string_list *list)
1145{
1146 int i, baselen = -1, first = 0, seen_bits = 0;
1147
1148 if (!report_garbage)
1149 return;
1150
1151 sort_string_list(list);
1152
1153 for (i = 0; i < list->nr; i++) {
1154 const char *path = list->items[i].string;
1155 if (baselen != -1 &&
1156 strncmp(path, list->items[first].string, baselen)) {
1157 report_helper(list, seen_bits, first, i);
1158 baselen = -1;
1159 seen_bits = 0;
1160 }
1161 if (baselen == -1) {
1162 const char *dot = strrchr(path, '.');
1163 if (!dot) {
1164 report_garbage("garbage found", path);
1165 continue;
1166 }
1167 baselen = dot - path + 1;
1168 first = i;
1169 }
1170 if (!strcmp(path + baselen, "pack"))
1171 seen_bits |= 1;
1172 else if (!strcmp(path + baselen, "idx"))
1173 seen_bits |= 2;
1174 }
1175 report_helper(list, seen_bits, first, list->nr);
1176}
1177
9d835df2 1178static void prepare_packed_git_one(char *objdir, int local)
1f688557 1179{
9cb18f56
JM
1180 /* Ensure that this buffer is large enough so that we can
1181 append "/pack/" without clobbering the stack even if
1182 strlen(objdir) were PATH_MAX. */
1183 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
1184 int len;
1185 DIR *dir;
1186 struct dirent *de;
543c5caa 1187 struct string_list garbage = STRING_LIST_INIT_DUP;
1f688557
JH
1188
1189 sprintf(path, "%s/pack", objdir);
1190 len = strlen(path);
1191 dir = opendir(path);
b5b16990 1192 if (!dir) {
26125f6b 1193 if (errno != ENOENT)
bd2afde8 1194 error("unable to open object pack directory: %s: %s",
26125f6b 1195 path, strerror(errno));
1f688557 1196 return;
b5b16990 1197 }
1f688557
JH
1198 path[len++] = '/';
1199 while ((de = readdir(dir)) != NULL) {
1200 int namelen = strlen(de->d_name);
1201 struct packed_git *p;
1202
543c5caa
NTND
1203 if (len + namelen + 1 > sizeof(path)) {
1204 if (report_garbage) {
1205 struct strbuf sb = STRBUF_INIT;
1206 strbuf_addf(&sb, "%.*s/%s", len - 1, path, de->d_name);
1207 report_garbage("path too long", sb.buf);
1208 strbuf_release(&sb);
1209 }
1210 continue;
1211 }
1212
1213 if (is_dot_or_dotdot(de->d_name))
9cb18f56
JM
1214 continue;
1215
1f688557 1216 strcpy(path + len, de->d_name);
d90906a9
NTND
1217
1218 if (has_extension(de->d_name, ".idx")) {
1219 /* Don't reopen a pack we already have. */
1220 for (p = packed_git; p; p = p->next) {
1221 if (!memcmp(path, p->pack_name, len + namelen - 4))
1222 break;
1223 }
1224 if (p == NULL &&
1225 /*
1226 * See if it really is a valid .idx file with
1227 * corresponding .pack file that we can map.
1228 */
1229 (p = add_packed_git(path, len + namelen, local)) != NULL)
1230 install_packed_git(p);
86f7780c 1231 }
543c5caa
NTND
1232
1233 if (!report_garbage)
1234 continue;
1235
1236 if (has_extension(de->d_name, ".idx") ||
1237 has_extension(de->d_name, ".pack") ||
d3d3e4c4 1238 has_extension(de->d_name, ".bitmap") ||
543c5caa
NTND
1239 has_extension(de->d_name, ".keep"))
1240 string_list_append(&garbage, path);
1241 else
1242 report_garbage("garbage found", path);
1f688557 1243 }
5b35bcd5 1244 closedir(dir);
543c5caa
NTND
1245 report_pack_garbage(&garbage);
1246 string_list_clear(&garbage, 0);
1f688557
JH
1247}
1248
b867092f
JH
1249static int sort_pack(const void *a_, const void *b_)
1250{
1251 struct packed_git *a = *((struct packed_git **)a_);
1252 struct packed_git *b = *((struct packed_git **)b_);
1253 int st;
1254
1255 /*
1256 * Local packs tend to contain objects specific to our
1257 * variant of the project than remote ones. In addition,
1258 * remote ones could be on a network mounted filesystem.
1259 * Favor local ones for these reasons.
1260 */
1261 st = a->pack_local - b->pack_local;
1262 if (st)
1263 return -st;
1264
1265 /*
1266 * Younger packs tend to contain more recent objects,
1267 * and more recent objects tend to get accessed more
1268 * often.
1269 */
1270 if (a->mtime < b->mtime)
1271 return 1;
1272 else if (a->mtime == b->mtime)
1273 return 0;
1274 return -1;
1275}
1276
1277static void rearrange_packed_git(void)
1278{
1279 struct packed_git **ary, *p;
1280 int i, n;
1281
1282 for (n = 0, p = packed_git; p; p = p->next)
1283 n++;
1284 if (n < 2)
1285 return;
1286
1287 /* prepare an array of packed_git for easier sorting */
1288 ary = xcalloc(n, sizeof(struct packed_git *));
1289 for (n = 0, p = packed_git; p; p = p->next)
1290 ary[n++] = p;
1291
1292 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1293
1294 /* link them back again */
1295 for (i = 0; i < n - 1; i++)
1296 ary[i]->next = ary[i + 1];
1297 ary[n - 1]->next = NULL;
1298 packed_git = ary[0];
1299
1300 free(ary);
1301}
1302
637cdd9d 1303static int prepare_packed_git_run_once = 0;
9a217f2a 1304void prepare_packed_git(void)
1f688557 1305{
d5a63b99 1306 struct alternate_object_database *alt;
1f688557 1307
637cdd9d 1308 if (prepare_packed_git_run_once)
1f688557 1309 return;
9d835df2 1310 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1311 prepare_alt_odb();
d5a63b99 1312 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 1313 alt->name[-1] = 0;
9d835df2 1314 prepare_packed_git_one(alt->base, 0);
1494e038 1315 alt->name[-1] = '/';
1f688557 1316 }
b867092f 1317 rearrange_packed_git();
637cdd9d
JK
1318 prepare_packed_git_run_once = 1;
1319}
1320
fc04c412 1321void reprepare_packed_git(void)
637cdd9d
JK
1322{
1323 prepare_packed_git_run_once = 0;
1324 prepare_packed_git();
1f688557
JH
1325}
1326
8eca0b47
NP
1327static void mark_bad_packed_object(struct packed_git *p,
1328 const unsigned char *sha1)
1329{
1330 unsigned i;
1331 for (i = 0; i < p->num_bad_objects; i++)
1332 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1333 return;
1334 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1335 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1336 p->num_bad_objects++;
1337}
1338
b6c4cecc 1339static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1340{
1341 struct packed_git *p;
1342 unsigned i;
1343
1344 for (p = packed_git; p; p = p->next)
1345 for (i = 0; i < p->num_bad_objects; i++)
1346 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1347 return p;
1348 return NULL;
ac939109
NP
1349}
1350
090ea126
NTND
1351/*
1352 * With an in-core object data in "map", rehash it to make sure the
1353 * object name actually matches "sha1" to detect object corruption.
1354 * With "map" == NULL, try reading the object named with "sha1" using
1355 * the streaming interface and rehash it to do the same.
1356 */
1357int check_sha1_signature(const unsigned char *sha1, void *map,
1358 unsigned long size, const char *type)
0fcfd160
LT
1359{
1360 unsigned char real_sha1[20];
090ea126
NTND
1361 enum object_type obj_type;
1362 struct git_istream *st;
1363 git_SHA_CTX c;
1364 char hdr[32];
1365 int hdrlen;
1366
1367 if (map) {
1368 hash_sha1_file(map, size, type, real_sha1);
1369 return hashcmp(sha1, real_sha1) ? -1 : 0;
1370 }
1371
1372 st = open_istream(sha1, &obj_type, &size, NULL);
1373 if (!st)
1374 return -1;
1375
1376 /* Generate the header */
1377 hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
1378
1379 /* Sha1.. */
1380 git_SHA1_Init(&c);
1381 git_SHA1_Update(&c, hdr, hdrlen);
1382 for (;;) {
1383 char buf[1024 * 16];
1384 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1385
f54fac53
JK
1386 if (readlen < 0) {
1387 close_istream(st);
1388 return -1;
1389 }
090ea126
NTND
1390 if (!readlen)
1391 break;
1392 git_SHA1_Update(&c, buf, readlen);
1393 }
1394 git_SHA1_Final(real_sha1, &c);
1395 close_istream(st);
a89fccd2 1396 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1397}
1398
ec73f580 1399int git_open_noatime(const char *name)
44d1c19e
LT
1400{
1401 static int sha1_file_open_flag = O_NOATIME;
44d1c19e 1402
f2e872aa
SP
1403 for (;;) {
1404 int fd = open(name, O_RDONLY | sha1_file_open_flag);
44d1c19e 1405 if (fd >= 0)
f2e872aa
SP
1406 return fd;
1407
f2e872aa
SP
1408 /* Might the failure be due to O_NOATIME? */
1409 if (errno != ENOENT && sha1_file_open_flag) {
44d1c19e 1410 sha1_file_open_flag = 0;
f2e872aa
SP
1411 continue;
1412 }
1413
1414 return -1;
44d1c19e 1415 }
44d1c19e
LT
1416}
1417
052fe5ea
JK
1418static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1419{
052fe5ea
JK
1420 struct alternate_object_database *alt;
1421
30d6c6ea 1422 if (!lstat(sha1_file_name(sha1), st))
052fe5ea
JK
1423 return 0;
1424
1425 prepare_alt_odb();
1426 errno = ENOENT;
1427 for (alt = alt_odb_list; alt; alt = alt->next) {
30d6c6ea 1428 fill_sha1_path(alt->name, sha1);
052fe5ea
JK
1429 if (!lstat(alt->base, st))
1430 return 0;
1431 }
1432
1433 return -1;
1434}
1435
44d1c19e
LT
1436static int open_sha1_file(const unsigned char *sha1)
1437{
1438 int fd;
44d1c19e 1439 struct alternate_object_database *alt;
d6c8a05b 1440 int most_interesting_errno;
44d1c19e 1441
30d6c6ea 1442 fd = git_open_noatime(sha1_file_name(sha1));
44d1c19e
LT
1443 if (fd >= 0)
1444 return fd;
d6c8a05b 1445 most_interesting_errno = errno;
44d1c19e
LT
1446
1447 prepare_alt_odb();
44d1c19e 1448 for (alt = alt_odb_list; alt; alt = alt->next) {
30d6c6ea 1449 fill_sha1_path(alt->name, sha1);
f4e51683 1450 fd = git_open_noatime(alt->base);
44d1c19e
LT
1451 if (fd >= 0)
1452 return fd;
d6c8a05b
JK
1453 if (most_interesting_errno == ENOENT)
1454 most_interesting_errno = errno;
44d1c19e 1455 }
d6c8a05b 1456 errno = most_interesting_errno;
44d1c19e
LT
1457 return -1;
1458}
1459
f0270efd 1460void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1461{
0fcfd160 1462 void *map;
144bde78 1463 int fd;
ace1534d 1464
44d1c19e
LT
1465 fd = open_sha1_file(sha1);
1466 map = NULL;
1467 if (fd >= 0) {
1468 struct stat st;
0fcfd160 1469
44d1c19e
LT
1470 if (!fstat(fd, &st)) {
1471 *size = xsize_t(st.st_size);
33e42de0
MM
1472 if (!*size) {
1473 /* mmap() is forbidden on empty files */
1474 error("object file %s is empty", sha1_file_name(sha1));
1475 return NULL;
1476 }
44d1c19e 1477 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1478 }
44d1c19e 1479 close(fd);
0fcfd160 1480 }
0fcfd160
LT
1481 return map;
1482}
1483
09ded04b
NP
1484unsigned long unpack_object_header_buffer(const unsigned char *buf,
1485 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1486{
ad1ed5ee 1487 unsigned shift;
48fb7deb 1488 unsigned long size, c;
ad1ed5ee
JH
1489 unsigned long used = 0;
1490
1491 c = buf[used++];
1492 *type = (c >> 4) & 7;
1493 size = c & 15;
1494 shift = 4;
1495 while (c & 0x80) {
f630cfda 1496 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1497 error("bad object header");
ea4f9685
JH
1498 size = used = 0;
1499 break;
09ded04b 1500 }
ad1ed5ee
JH
1501 c = buf[used++];
1502 size += (c & 0x7f) << shift;
1503 shift += 7;
1504 }
1505 *sizep = size;
1506 return used;
1507}
1508
eb4f4076 1509int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
ad1ed5ee 1510{
c4483576
LT
1511 /* Get the data stream */
1512 memset(stream, 0, sizeof(*stream));
1513 stream->next_in = map;
1514 stream->avail_in = mapsize;
1515 stream->next_out = buffer;
93821bd9
LT
1516 stream->avail_out = bufsiz;
1517
39c68542 1518 git_inflate_init(stream);
cc5c54e7 1519 return git_inflate(stream, 0);
c4483576
LT
1520}
1521
ef49a7a0 1522static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1523{
1524 int bytes = strlen(buffer) + 1;
3aee68aa 1525 unsigned char *buf = xmallocz(size);
93821bd9 1526 unsigned long n;
7efbff75 1527 int status = Z_OK;
5180cacc 1528
93821bd9
LT
1529 n = stream->total_out - bytes;
1530 if (n > size)
1531 n = size;
1532 memcpy(buf, (char *) buffer + bytes, n);
1533 bytes = n;
456cdf6e
LT
1534 if (bytes <= size) {
1535 /*
1536 * The above condition must be (bytes <= size), not
1537 * (bytes < size). In other words, even though we
ccf5ace0 1538 * expect no more output and set avail_out to zero,
456cdf6e
LT
1539 * the input zlib stream may have bytes that express
1540 * "this concludes the stream", and we *do* want to
1541 * eat that input.
1542 *
1543 * Otherwise we would not be able to test that we
1544 * consumed all the input to reach the expected size;
1545 * we also want to check that zlib tells us that all
1546 * went well with status == Z_STREAM_END at the end.
1547 */
5180cacc
LT
1548 stream->next_out = buf + bytes;
1549 stream->avail_out = size - bytes;
7efbff75 1550 while (status == Z_OK)
39c68542 1551 status = git_inflate(stream, Z_FINISH);
5180cacc 1552 }
456cdf6e 1553 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1554 git_inflate_end(stream);
7efbff75
JH
1555 return buf;
1556 }
1557
1558 if (status < 0)
1559 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1560 else if (stream->avail_in)
1561 error("garbage at end of loose object '%s'",
1562 sha1_to_hex(sha1));
1563 free(buf);
1564 return NULL;
5180cacc
LT
1565}
1566
1567/*
1568 * We used to just use "sscanf()", but that's actually way
1569 * too permissive for what we want to check. So do an anal
1570 * object header parse by hand.
1571 */
f0270efd 1572int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1573{
21666f1a 1574 char type[10];
5180cacc
LT
1575 int i;
1576 unsigned long size;
1577
1578 /*
a6080a0a 1579 * The type can be at most ten bytes (including the
5180cacc 1580 * terminating '\0' that we add), and is followed by
21666f1a 1581 * a space.
5180cacc 1582 */
21666f1a 1583 i = 0;
5180cacc
LT
1584 for (;;) {
1585 char c = *hdr++;
1586 if (c == ' ')
1587 break;
21666f1a
NP
1588 type[i++] = c;
1589 if (i >= sizeof(type))
5180cacc 1590 return -1;
5180cacc 1591 }
21666f1a 1592 type[i] = 0;
5180cacc
LT
1593
1594 /*
1595 * The length must follow immediately, and be in canonical
1596 * decimal format (ie "010" is not valid).
1597 */
1598 size = *hdr++ - '0';
1599 if (size > 9)
1600 return -1;
1601 if (size) {
1602 for (;;) {
1603 unsigned long c = *hdr - '0';
1604 if (c > 9)
1605 break;
1606 hdr++;
1607 size = size * 10 + c;
1608 }
1609 }
1610 *sizep = size;
1611
1612 /*
1613 * The length must be followed by a zero byte
1614 */
21666f1a 1615 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1616}
1617
7efbff75 1618static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1619{
5180cacc 1620 int ret;
ef49a7a0 1621 git_zstream stream;
5180cacc 1622 char hdr[8192];
0fcfd160 1623
5180cacc 1624 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1625 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1626 return NULL;
1627
7efbff75 1628 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1629}
1630
54dab52a
NP
1631unsigned long get_size_from_delta(struct packed_git *p,
1632 struct pack_window **w_curs,
1633 off_t curpos)
1634{
1635 const unsigned char *data;
1636 unsigned char delta_head[20], *in;
ef49a7a0 1637 git_zstream stream;
54dab52a
NP
1638 int st;
1639
1640 memset(&stream, 0, sizeof(stream));
1641 stream.next_out = delta_head;
1642 stream.avail_out = sizeof(delta_head);
1643
39c68542 1644 git_inflate_init(&stream);
54dab52a
NP
1645 do {
1646 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1647 stream.next_in = in;
39c68542 1648 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1649 curpos += stream.next_in - in;
1650 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1651 stream.total_out < sizeof(delta_head));
39c68542 1652 git_inflate_end(&stream);
3d77d877
NP
1653 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1654 error("delta data unpack-initial failed");
1655 return 0;
1656 }
54dab52a
NP
1657
1658 /* Examine the initial part of the delta to figure out
1659 * the result size.
1660 */
1661 data = delta_head;
1662
1663 /* ignore base size */
1664 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1665
1666 /* Read the result size */
1667 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1668}
1669
c4001d92 1670static off_t get_delta_base(struct packed_git *p,
03e79c88 1671 struct pack_window **w_curs,
c4001d92 1672 off_t *curpos,
21666f1a 1673 enum object_type type,
c4001d92 1674 off_t delta_obj_offset)
eb32d236 1675{
2b87c45b 1676 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1677 off_t base_offset;
eb32d236 1678
8d8a4ea5
SP
1679 /* use_pack() assured us we have [base_info, base_info + 20)
1680 * as a range that we can look at without walking off the
1681 * end of the mapped window. Its actually the hash size
1682 * that is assured. An OFS_DELTA longer than the hash size
1683 * is stupid, as then a REF_DELTA would be smaller to store.
1684 */
21666f1a 1685 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1686 unsigned used = 0;
1687 unsigned char c = base_info[used++];
1688 base_offset = c & 127;
1689 while (c & 128) {
1690 base_offset += 1;
8723f216 1691 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1692 return 0; /* overflow */
eb32d236
NP
1693 c = base_info[used++];
1694 base_offset = (base_offset << 7) + (c & 127);
1695 }
1696 base_offset = delta_obj_offset - base_offset;
d8f32556 1697 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 1698 return 0; /* out of bound */
2b87c45b 1699 *curpos += used;
21666f1a 1700 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1701 /* The base entry _must_ be in the same pack */
1702 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1703 *curpos += 20;
eb32d236
NP
1704 } else
1705 die("I am totally screwed");
2b87c45b 1706 return base_offset;
eb32d236
NP
1707}
1708
5d642e75
JK
1709/*
1710 * Like get_delta_base above, but we return the sha1 instead of the pack
1711 * offset. This means it is cheaper for REF deltas (we do not have to do
1712 * the final object lookup), but more expensive for OFS deltas (we
1713 * have to load the revidx to convert the offset back into a sha1).
1714 */
1715static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1716 struct pack_window **w_curs,
1717 off_t curpos,
1718 enum object_type type,
1719 off_t delta_obj_offset)
1720{
1721 if (type == OBJ_REF_DELTA) {
1722 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1723 return base;
1724 } else if (type == OBJ_OFS_DELTA) {
1725 struct revindex_entry *revidx;
1726 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1727 type, delta_obj_offset);
1728
1729 if (!base_offset)
1730 return NULL;
1731
1732 revidx = find_pack_revindex(p, base_offset);
1733 if (!revidx)
1734 return NULL;
1735
1736 return nth_packed_object_sha1(p, revidx->nr);
1737 } else
1738 return NULL;
1739}
1740
f8c8abc5
JH
1741int unpack_object_header(struct packed_git *p,
1742 struct pack_window **w_curs,
1743 off_t *curpos,
1744 unsigned long *sizep)
a733cb60 1745{
03e79c88 1746 unsigned char *base;
ef49a7a0 1747 unsigned long left;
ad1ed5ee 1748 unsigned long used;
2b87c45b 1749 enum object_type type;
a733cb60 1750
8d8a4ea5 1751 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 1752 * as a range that we can look at. (Its actually the hash
3dff5379 1753 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1754 * the maximum deflated object size is 2^137, which is just
1755 * insane, so we know won't exceed what we have been given.
1756 */
2b87c45b 1757 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
1758 used = unpack_object_header_buffer(base, left, &type, sizep);
1759 if (!used) {
1760 type = OBJ_BAD;
1761 } else
1762 *curpos += used;
ad1ed5ee 1763
2b87c45b 1764 return type;
a733cb60
LT
1765}
1766
790d96c0
TR
1767static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1768{
1769 int type;
1770 struct revindex_entry *revidx;
1771 const unsigned char *sha1;
1772 revidx = find_pack_revindex(p, obj_offset);
1773 if (!revidx)
1774 return OBJ_BAD;
1775 sha1 = nth_packed_object_sha1(p, revidx->nr);
1776 mark_bad_packed_object(p, sha1);
1777 type = sha1_object_info(sha1, NULL);
1778 if (type <= OBJ_NONE)
1779 return OBJ_BAD;
1780 return type;
1781}
1782
790d96c0
TR
1783#define POI_STACK_PREALLOC 64
1784
90191d37
JK
1785static enum object_type packed_to_object_type(struct packed_git *p,
1786 off_t obj_offset,
1787 enum object_type type,
1788 struct pack_window **w_curs,
1789 off_t curpos)
1f688557 1790{
790d96c0
TR
1791 off_t small_poi_stack[POI_STACK_PREALLOC];
1792 off_t *poi_stack = small_poi_stack;
1793 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
5db47c2b 1794
790d96c0
TR
1795 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1796 off_t base_offset;
90191d37 1797 unsigned long size;
790d96c0
TR
1798 /* Push the object we're going to leave behind */
1799 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1800 poi_stack_alloc = alloc_nr(poi_stack_nr);
1801 poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
1802 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1803 } else {
1804 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1805 }
1806 poi_stack[poi_stack_nr++] = obj_offset;
1807 /* If parsing the base offset fails, just unwind */
90191d37 1808 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
790d96c0
TR
1809 if (!base_offset)
1810 goto unwind;
1811 curpos = obj_offset = base_offset;
90191d37 1812 type = unpack_object_header(p, w_curs, &curpos, &size);
790d96c0
TR
1813 if (type <= OBJ_NONE) {
1814 /* If getting the base itself fails, we first
1815 * retry the base, otherwise unwind */
1816 type = retry_bad_packed_offset(p, base_offset);
1817 if (type > OBJ_NONE)
1818 goto out;
1819 goto unwind;
1820 }
1821 }
1822
21666f1a 1823 switch (type) {
790d96c0 1824 case OBJ_BAD:
a733cb60 1825 case OBJ_COMMIT:
a733cb60 1826 case OBJ_TREE:
a733cb60 1827 case OBJ_BLOB:
a733cb60 1828 case OBJ_TAG:
a69d0943 1829 break;
1f688557 1830 default:
3d77d877
NP
1831 error("unknown object type %i at offset %"PRIuMAX" in %s",
1832 type, (uintmax_t)obj_offset, p->pack_name);
1833 type = OBJ_BAD;
1f688557 1834 }
790d96c0
TR
1835
1836out:
1837 if (poi_stack != small_poi_stack)
1838 free(poi_stack);
21666f1a 1839 return type;
790d96c0
TR
1840
1841unwind:
1842 while (poi_stack_nr) {
1843 obj_offset = poi_stack[--poi_stack_nr];
1844 type = retry_bad_packed_offset(p, obj_offset);
1845 if (type > OBJ_NONE)
1846 goto out;
1847 }
1848 type = OBJ_BAD;
1849 goto out;
1f688557
JH
1850}
1851
90191d37 1852static int packed_object_info(struct packed_git *p, off_t obj_offset,
23c339c0 1853 struct object_info *oi)
90191d37
JK
1854{
1855 struct pack_window *w_curs = NULL;
1856 unsigned long size;
1857 off_t curpos = obj_offset;
1858 enum object_type type;
1859
412916ee
JK
1860 /*
1861 * We always get the representation type, but only convert it to
1862 * a "real" type later if the caller is interested.
1863 */
90191d37
JK
1864 type = unpack_object_header(p, &w_curs, &curpos, &size);
1865
23c339c0 1866 if (oi->sizep) {
90191d37
JK
1867 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1868 off_t tmp_pos = curpos;
1869 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1870 type, obj_offset);
1871 if (!base_offset) {
1872 type = OBJ_BAD;
1873 goto out;
1874 }
23c339c0
JK
1875 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1876 if (*oi->sizep == 0) {
90191d37
JK
1877 type = OBJ_BAD;
1878 goto out;
1879 }
1880 } else {
23c339c0 1881 *oi->sizep = size;
90191d37
JK
1882 }
1883 }
1884
23c339c0 1885 if (oi->disk_sizep) {
90191d37 1886 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
23c339c0 1887 *oi->disk_sizep = revidx[1].offset - obj_offset;
90191d37
JK
1888 }
1889
23c339c0
JK
1890 if (oi->typep) {
1891 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
1892 if (*oi->typep < 0) {
412916ee
JK
1893 type = OBJ_BAD;
1894 goto out;
1895 }
1896 }
90191d37 1897
5d642e75
JK
1898 if (oi->delta_base_sha1) {
1899 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1900 const unsigned char *base;
1901
1902 base = get_delta_base_sha1(p, &w_curs, curpos,
1903 type, obj_offset);
1904 if (!base) {
1905 type = OBJ_BAD;
1906 goto out;
1907 }
1908
1909 hashcpy(oi->delta_base_sha1, base);
1910 } else
1911 hashclr(oi->delta_base_sha1);
1912 }
1913
90191d37
JK
1914out:
1915 unuse_pack(&w_curs);
1916 return type;
1917}
1918
eb950c19 1919static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1920 struct pack_window **w_curs,
c4001d92 1921 off_t curpos,
eb950c19 1922 unsigned long size)
de530aaa
SP
1923{
1924 int st;
ef49a7a0 1925 git_zstream stream;
079afb18 1926 unsigned char *buffer, *in;
de530aaa 1927
4ab07e4d 1928 buffer = xmallocz(size);
de530aaa 1929 memset(&stream, 0, sizeof(stream));
de530aaa 1930 stream.next_out = buffer;
39eea7bd 1931 stream.avail_out = size + 1;
de530aaa 1932
39c68542 1933 git_inflate_init(&stream);
079afb18 1934 do {
2b87c45b 1935 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 1936 stream.next_in = in;
39c68542 1937 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
1938 if (!stream.avail_out)
1939 break; /* the payload is larger than it should be */
2b87c45b 1940 curpos += stream.next_in - in;
079afb18 1941 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 1942 git_inflate_end(&stream);
de530aaa
SP
1943 if ((st != Z_STREAM_END) || stream.total_out != size) {
1944 free(buffer);
1945 return NULL;
1946 }
1947
1948 return buffer;
1949}
1950
e5e01619
LT
1951#define MAX_DELTA_CACHE (256)
1952
18bdec11 1953static size_t delta_base_cached;
5e08ecbf
NP
1954
1955static struct delta_base_cache_lru_list {
1956 struct delta_base_cache_lru_list *prev;
1957 struct delta_base_cache_lru_list *next;
1958} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1959
e5e01619 1960static struct delta_base_cache_entry {
5e08ecbf
NP
1961 struct delta_base_cache_lru_list lru;
1962 void *data;
e5e01619
LT
1963 struct packed_git *p;
1964 off_t base_offset;
1965 unsigned long size;
e5e01619
LT
1966 enum object_type type;
1967} delta_base_cache[MAX_DELTA_CACHE];
1968
1969static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1970{
1971 unsigned long hash;
1972
1973 hash = (unsigned long)p + (unsigned long)base_offset;
1974 hash += (hash >> 8) + (hash >> 16);
3358004a 1975 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1976}
1977
84dd81c1
TR
1978static struct delta_base_cache_entry *
1979get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
5266d369
JH
1980{
1981 unsigned long hash = pack_entry_hash(p, base_offset);
84dd81c1
TR
1982 return delta_base_cache + hash;
1983}
1984
1985static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
1986 struct packed_git *p, off_t base_offset)
1987{
5266d369
JH
1988 return (ent->data && ent->p == p && ent->base_offset == base_offset);
1989}
1990
84dd81c1
TR
1991static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1992{
1993 struct delta_base_cache_entry *ent;
1994 ent = get_delta_base_cache_entry(p, base_offset);
1995 return eq_delta_base_cache_entry(ent, p, base_offset);
1996}
1997
1998static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1999{
2000 ent->data = NULL;
2001 ent->lru.next->prev = ent->lru.prev;
2002 ent->lru.prev->next = ent->lru.next;
2003 delta_base_cached -= ent->size;
2004}
2005
62f255ad 2006static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 2007 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 2008{
84dd81c1 2009 struct delta_base_cache_entry *ent;
e5e01619 2010 void *ret;
e5e01619 2011
84dd81c1
TR
2012 ent = get_delta_base_cache_entry(p, base_offset);
2013
2014 if (!eq_delta_base_cache_entry(ent, p, base_offset))
749bc58c 2015 return unpack_entry(p, base_offset, type, base_size);
e5e01619 2016
84dd81c1
TR
2017 ret = ent->data;
2018
2019 if (!keep_cache)
2020 clear_delta_base_cache_entry(ent);
2021 else
182af834 2022 ret = xmemdupz(ent->data, ent->size);
e5e01619
LT
2023 *type = ent->type;
2024 *base_size = ent->size;
2025 return ret;
62f255ad
LT
2026}
2027
18bdec11
SP
2028static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2029{
2030 if (ent->data) {
2031 free(ent->data);
2032 ent->data = NULL;
5e08ecbf
NP
2033 ent->lru.next->prev = ent->lru.prev;
2034 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
2035 delta_base_cached -= ent->size;
2036 }
2037}
2038
3d20c636
SP
2039void clear_delta_base_cache(void)
2040{
2041 unsigned long p;
2042 for (p = 0; p < MAX_DELTA_CACHE; p++)
2043 release_delta_base_cache(&delta_base_cache[p]);
2044}
2045
62f255ad
LT
2046static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2047 void *base, unsigned long base_size, enum object_type type)
2048{
5e08ecbf 2049 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 2050 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 2051 struct delta_base_cache_lru_list *lru;
e5e01619 2052
18bdec11
SP
2053 release_delta_base_cache(ent);
2054 delta_base_cached += base_size;
5e08ecbf
NP
2055
2056 for (lru = delta_base_cache_lru.next;
2057 delta_base_cached > delta_base_cache_limit
2058 && lru != &delta_base_cache_lru;
2059 lru = lru->next) {
2060 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
2061 if (f->type == OBJ_BLOB)
2062 release_delta_base_cache(f);
2063 }
5e08ecbf
NP
2064 for (lru = delta_base_cache_lru.next;
2065 delta_base_cached > delta_base_cache_limit
2066 && lru != &delta_base_cache_lru;
2067 lru = lru->next) {
2068 struct delta_base_cache_entry *f = (void *)lru;
2069 release_delta_base_cache(f);
2070 }
18bdec11 2071
e5e01619
LT
2072 ent->p = p;
2073 ent->base_offset = base_offset;
2074 ent->type = type;
2075 ent->data = base;
2076 ent->size = base_size;
5e08ecbf
NP
2077 ent->lru.next = &delta_base_cache_lru;
2078 ent->lru.prev = delta_base_cache_lru.prev;
2079 delta_base_cache_lru.prev->next = &ent->lru;
2080 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
2081}
2082
c2c5b270
CC
2083static void *read_object(const unsigned char *sha1, enum object_type *type,
2084 unsigned long *size);
2085
5f44324d
JH
2086static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2087{
2088 static FILE *log_file;
2089
b12ca963
NTND
2090 if (!log_pack_access)
2091 log_pack_access = getenv("GIT_TRACE_PACK_ACCESS");
2092 if (!log_pack_access)
2093 log_pack_access = no_log_pack_access;
2094 if (log_pack_access == no_log_pack_access)
2095 return;
2096
5f44324d
JH
2097 if (!log_file) {
2098 log_file = fopen(log_pack_access, "w");
2099 if (!log_file) {
2100 error("cannot open pack access log '%s' for writing: %s",
2101 log_pack_access, strerror(errno));
b12ca963 2102 log_pack_access = no_log_pack_access;
5f44324d
JH
2103 return;
2104 }
2105 }
2106 fprintf(log_file, "%s %"PRIuMAX"\n",
2107 p->pack_name, (uintmax_t)obj_offset);
2108 fflush(log_file);
2109}
2110
0e8189e2
NP
2111int do_check_packed_object_crc;
2112
abe601bb
TR
2113#define UNPACK_ENTRY_STACK_PREALLOC 64
2114struct unpack_entry_stack_ent {
2115 off_t obj_offset;
2116 off_t curpos;
2117 unsigned long size;
2118};
2119
c4001d92 2120void *unpack_entry(struct packed_git *p, off_t obj_offset,
abe601bb 2121 enum object_type *final_type, unsigned long *final_size)
1f688557 2122{
03e79c88 2123 struct pack_window *w_curs = NULL;
c4001d92 2124 off_t curpos = obj_offset;
abe601bb
TR
2125 void *data = NULL;
2126 unsigned long size;
2127 enum object_type type;
2128 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2129 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2130 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2131 int base_from_cache = 0;
1f688557 2132
b12ca963 2133 if (log_pack_access != no_log_pack_access)
5f44324d
JH
2134 write_pack_access_log(p, obj_offset);
2135
abe601bb
TR
2136 /* PHASE 1: drill down to the innermost base object */
2137 for (;;) {
2138 off_t base_offset;
2139 int i;
2140 struct delta_base_cache_entry *ent;
2141
77965f8b
NTND
2142 ent = get_delta_base_cache_entry(p, curpos);
2143 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2144 type = ent->type;
2145 data = ent->data;
2146 size = ent->size;
2147 clear_delta_base_cache_entry(ent);
2148 base_from_cache = 1;
2149 break;
2150 }
2151
abe601bb
TR
2152 if (do_check_packed_object_crc && p->index_version > 1) {
2153 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2154 unsigned long len = revidx[1].offset - obj_offset;
2155 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2156 const unsigned char *sha1 =
2157 nth_packed_object_sha1(p, revidx->nr);
2158 error("bad packed object CRC for %s",
2159 sha1_to_hex(sha1));
2160 mark_bad_packed_object(p, sha1);
2161 unuse_pack(&w_curs);
2162 return NULL;
2163 }
2164 }
2165
abe601bb
TR
2166 type = unpack_object_header(p, &w_curs, &curpos, &size);
2167 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2168 break;
2169
2170 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2171 if (!base_offset) {
2172 error("failed to validate delta base reference "
2173 "at offset %"PRIuMAX" from %s",
2174 (uintmax_t)curpos, p->pack_name);
2175 /* bail to phase 2, in hopes of recovery */
2176 data = NULL;
2177 break;
2178 }
2179
2180 /* push object, proceed to base */
2181 if (delta_stack_nr >= delta_stack_alloc
2182 && delta_stack == small_delta_stack) {
2183 delta_stack_alloc = alloc_nr(delta_stack_nr);
2184 delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
2185 memcpy(delta_stack, small_delta_stack,
2186 sizeof(*delta_stack)*delta_stack_nr);
2187 } else {
2188 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2189 }
2190 i = delta_stack_nr++;
2191 delta_stack[i].obj_offset = obj_offset;
2192 delta_stack[i].curpos = curpos;
2193 delta_stack[i].size = size;
2194
2195 curpos = obj_offset = base_offset;
0e8189e2
NP
2196 }
2197
abe601bb
TR
2198 /* PHASE 2: handle the base */
2199 switch (type) {
eb32d236
NP
2200 case OBJ_OFS_DELTA:
2201 case OBJ_REF_DELTA:
abe601bb
TR
2202 if (data)
2203 die("BUG in unpack_entry: left loop at a valid delta");
4d703a1a 2204 break;
a733cb60 2205 case OBJ_COMMIT:
a733cb60 2206 case OBJ_TREE:
a733cb60 2207 case OBJ_BLOB:
a733cb60 2208 case OBJ_TAG:
abe601bb
TR
2209 if (!base_from_cache)
2210 data = unpack_compressed_entry(p, &w_curs, curpos, size);
4d703a1a 2211 break;
1f688557 2212 default:
8eca0b47
NP
2213 data = NULL;
2214 error("unknown object type %i at offset %"PRIuMAX" in %s",
abe601bb
TR
2215 type, (uintmax_t)obj_offset, p->pack_name);
2216 }
2217
2218 /* PHASE 3: apply deltas in order */
2219
2220 /* invariants:
2221 * 'data' holds the base data, or NULL if there was corruption
2222 */
2223 while (delta_stack_nr) {
2224 void *delta_data;
2225 void *base = data;
2226 unsigned long delta_size, base_size = size;
2227 int i;
2228
2229 data = NULL;
2230
2231 if (base)
2232 add_delta_base_cache(p, obj_offset, base, base_size, type);
2233
2234 if (!base) {
2235 /*
2236 * We're probably in deep shit, but let's try to fetch
2237 * the required base anyway from another pack or loose.
2238 * This is costly but should happen only in the presence
2239 * of a corrupted pack, and is better than failing outright.
2240 */
2241 struct revindex_entry *revidx;
2242 const unsigned char *base_sha1;
2243 revidx = find_pack_revindex(p, obj_offset);
2244 if (revidx) {
2245 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2246 error("failed to read delta base object %s"
2247 " at offset %"PRIuMAX" from %s",
2248 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2249 p->pack_name);
2250 mark_bad_packed_object(p, base_sha1);
2251 base = read_object(base_sha1, &type, &base_size);
2252 }
2253 }
2254
2255 i = --delta_stack_nr;
2256 obj_offset = delta_stack[i].obj_offset;
2257 curpos = delta_stack[i].curpos;
2258 delta_size = delta_stack[i].size;
2259
2260 if (!base)
2261 continue;
2262
2263 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2264
2265 if (!delta_data) {
2266 error("failed to unpack compressed delta "
2267 "at offset %"PRIuMAX" from %s",
2268 (uintmax_t)curpos, p->pack_name);
abe601bb
TR
2269 data = NULL;
2270 continue;
2271 }
2272
2273 data = patch_delta(base, base_size,
2274 delta_data, delta_size,
2275 &size);
1ee886c1
JK
2276
2277 /*
2278 * We could not apply the delta; warn the user, but keep going.
2279 * Our failure will be noticed either in the next iteration of
2280 * the loop, or if this is the final delta, in the caller when
2281 * we return NULL. Those code paths will take care of making
2282 * a more explicit warning and retrying with another copy of
2283 * the object.
2284 */
abe601bb 2285 if (!data)
1ee886c1 2286 error("failed to apply delta");
abe601bb 2287
4b8f772c 2288 free(delta_data);
1f688557 2289 }
abe601bb
TR
2290
2291 *final_type = type;
2292 *final_size = size;
2293
03e79c88 2294 unuse_pack(&w_curs);
019d1e65
NTND
2295
2296 if (delta_stack != small_delta_stack)
2297 free(delta_stack);
2298
21666f1a 2299 return data;
1f688557
JH
2300}
2301
d079837e 2302const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 2303 uint32_t n)
9a217f2a 2304{
42873078 2305 const unsigned char *index = p->index_data;
d079837e
SP
2306 if (!index) {
2307 if (open_pack_index(p))
2308 return NULL;
2309 index = p->index_data;
2310 }
57059091 2311 if (n >= p->num_objects)
d72308e0 2312 return NULL;
74e34e1f
NP
2313 index += 4 * 256;
2314 if (p->index_version == 1) {
2315 return index + 24 * n + 4;
2316 } else {
2317 index += 8;
2318 return index + 20 * n;
2319 }
2320}
2321
99093238 2322off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
2323{
2324 const unsigned char *index = p->index_data;
2325 index += 4 * 256;
2326 if (p->index_version == 1) {
2327 return ntohl(*((uint32_t *)(index + 24 * n)));
2328 } else {
2329 uint32_t off;
2330 index += 8 + p->num_objects * (20 + 4);
2331 off = ntohl(*((uint32_t *)(index + 4 * n)));
2332 if (!(off & 0x80000000))
2333 return off;
2334 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2335 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2336 ntohl(*((uint32_t *)(index + 4)));
2337 }
9a217f2a
JH
2338}
2339
c4001d92 2340off_t find_pack_entry_one(const unsigned char *sha1,
43057304 2341 struct packed_git *p)
1f688557 2342{
42873078 2343 const uint32_t *level1_ofs = p->index_data;
42873078 2344 const unsigned char *index = p->index_data;
628522ec
JH
2345 unsigned hi, lo, stride;
2346 static int use_lookup = -1;
2347 static int debug_lookup = -1;
2348
2349 if (debug_lookup < 0)
2350 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 2351
d079837e
SP
2352 if (!index) {
2353 if (open_pack_index(p))
2354 return 0;
2355 level1_ofs = p->index_data;
2356 index = p->index_data;
2357 }
74e34e1f
NP
2358 if (p->index_version > 1) {
2359 level1_ofs += 2;
2360 index += 8;
2361 }
42873078 2362 index += 4 * 256;
74e34e1f
NP
2363 hi = ntohl(level1_ofs[*sha1]);
2364 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2365 if (p->index_version > 1) {
2366 stride = 20;
2367 } else {
2368 stride = 24;
2369 index += 4;
2370 }
2371
2372 if (debug_lookup)
6e1c2344 2373 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2374 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2375
2376 if (use_lookup < 0)
2377 use_lookup = !!getenv("GIT_USE_LOOKUP");
2378 if (use_lookup) {
2379 int pos = sha1_entry_pos(index, stride, 0,
2380 lo, hi, p->num_objects, sha1);
2381 if (pos < 0)
2382 return 0;
2383 return nth_packed_object_offset(p, pos);
2384 }
1f688557
JH
2385
2386 do {
74e34e1f 2387 unsigned mi = (lo + hi) / 2;
628522ec
JH
2388 int cmp = hashcmp(index + mi * stride, sha1);
2389
2390 if (debug_lookup)
2391 printf("lo %u hi %u rg %u mi %u\n",
2392 lo, hi, hi - lo, mi);
43057304 2393 if (!cmp)
74e34e1f 2394 return nth_packed_object_offset(p, mi);
1f688557
JH
2395 if (cmp > 0)
2396 hi = mi;
2397 else
2398 lo = mi+1;
2399 } while (lo < hi);
2400 return 0;
2401}
2402
4c080182 2403int is_pack_valid(struct packed_git *p)
d131b7af
SP
2404{
2405 /* An already open pack is known to be valid. */
2406 if (p->pack_fd != -1)
2407 return 1;
2408
2409 /* If the pack has one window completely covering the
2410 * file size, the pack is known to be valid even if
2411 * the descriptor is not currently open.
2412 */
2413 if (p->windows) {
2414 struct pack_window *w = p->windows;
2415
2416 if (!w->offset && w->len == p->pack_size)
2417 return 1;
2418 }
2419
2420 /* Force the pack to open to prove its valid. */
2421 return !open_packed_git(p);
2422}
2423
95099731
NTND
2424static int fill_pack_entry(const unsigned char *sha1,
2425 struct pack_entry *e,
2426 struct packed_git *p)
2427{
2428 off_t offset;
2429
2430 if (p->num_bad_objects) {
2431 unsigned i;
2432 for (i = 0; i < p->num_bad_objects; i++)
2433 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2434 return 0;
2435 }
2436
2437 offset = find_pack_entry_one(sha1, p);
2438 if (!offset)
2439 return 0;
2440
2441 /*
2442 * We are about to tell the caller where they can locate the
2443 * requested object. We better make sure the packfile is
2444 * still here and can be accessed before supplying that
2445 * answer, as it may have been deleted since the index was
2446 * loaded!
2447 */
2448 if (!is_pack_valid(p)) {
2449 warning("packfile %s cannot be accessed", p->pack_name);
2450 return 0;
2451 }
2452 e->offset = offset;
2453 e->p = p;
2454 hashcpy(e->sha1, sha1);
2455 return 1;
2456}
2457
d40d535b
MH
2458/*
2459 * Iff a pack file contains the object named by sha1, return true and
2460 * store its location to e.
2461 */
4d6acb70 2462static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557
JH
2463{
2464 struct packed_git *p;
43057304 2465
1f688557 2466 prepare_packed_git();
f7c22cc6
NP
2467 if (!packed_git)
2468 return 0;
1f688557 2469
c01f51cc
NTND
2470 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2471 return 1;
8eca0b47 2472
c01f51cc 2473 for (p = packed_git; p; p = p->next) {
1b1005d1
MH
2474 if (p == last_found_pack)
2475 continue; /* we already checked this one */
f7c22cc6 2476
1b1005d1
MH
2477 if (fill_pack_entry(sha1, e, p)) {
2478 last_found_pack = p;
2479 return 1;
2480 }
c01f51cc 2481 }
1f688557
JH
2482 return 0;
2483}
2484
a6080a0a 2485struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2486 struct packed_git *packs)
2487{
2488 struct packed_git *p;
bf592c50
DB
2489
2490 for (p = packs; p; p = p->next) {
43057304 2491 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2492 return p;
2493 }
2494 return NULL;
21666f1a 2495
bf592c50
DB
2496}
2497
052fe5ea 2498static int sha1_loose_object_info(const unsigned char *sha1,
23c339c0 2499 struct object_info *oi)
65c2e0c3 2500{
36e4d74a 2501 int status;
65c2e0c3
JH
2502 unsigned long mapsize, size;
2503 void *map;
ef49a7a0 2504 git_zstream stream;
d65a16f6 2505 char hdr[32];
65c2e0c3 2506
5d642e75
JK
2507 if (oi->delta_base_sha1)
2508 hashclr(oi->delta_base_sha1);
2509
052fe5ea
JK
2510 /*
2511 * If we don't care about type or size, then we don't
4ef8d1dd
JH
2512 * need to look inside the object at all. Note that we
2513 * do not optimize out the stat call, even if the
2514 * caller doesn't care about the disk-size, since our
2515 * return value implicitly indicates whether the
2516 * object even exists.
052fe5ea 2517 */
23c339c0 2518 if (!oi->typep && !oi->sizep) {
4ef8d1dd
JH
2519 struct stat st;
2520 if (stat_sha1_file(sha1, &st) < 0)
2521 return -1;
2522 if (oi->disk_sizep)
23c339c0 2523 *oi->disk_sizep = st.st_size;
052fe5ea
JK
2524 return 0;
2525 }
2526
bb6b8e4f 2527 map = map_sha1_file(sha1, &mapsize);
f0df4ed5 2528 if (!map)
dbea72a8 2529 return -1;
23c339c0
JK
2530 if (oi->disk_sizep)
2531 *oi->disk_sizep = mapsize;
36e4d74a
JH
2532 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2533 status = error("unable to unpack %s header",
2534 sha1_to_hex(sha1));
21666f1a 2535 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 2536 status = error("unable to parse %s header", sha1_to_hex(sha1));
23c339c0
JK
2537 else if (oi->sizep)
2538 *oi->sizep = size;
39c68542 2539 git_inflate_end(&stream);
65c2e0c3 2540 munmap(map, mapsize);
23c339c0
JK
2541 if (oi->typep)
2542 *oi->typep = status;
052fe5ea 2543 return 0;
65c2e0c3
JH
2544}
2545
de7b5d62 2546int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
f0df4ed5 2547{
c4d9986f 2548 struct cached_object *co;
f0df4ed5 2549 struct pack_entry e;
5b086407 2550 int rtype;
1f7117ef 2551 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
f0df4ed5 2552
1f7117ef 2553 co = find_cached_object(real);
c4d9986f 2554 if (co) {
5b086407
JK
2555 if (oi->typep)
2556 *(oi->typep) = co->type;
9a490590
JH
2557 if (oi->sizep)
2558 *(oi->sizep) = co->size;
161f00e7
JK
2559 if (oi->disk_sizep)
2560 *(oi->disk_sizep) = 0;
5d642e75
JK
2561 if (oi->delta_base_sha1)
2562 hashclr(oi->delta_base_sha1);
9a490590 2563 oi->whence = OI_CACHED;
5b086407 2564 return 0;
c4d9986f
NTND
2565 }
2566
1f7117ef 2567 if (!find_pack_entry(real, &e)) {
ddd63e64 2568 /* Most likely it's a loose object. */
1f7117ef 2569 if (!sha1_loose_object_info(real, oi)) {
9a490590 2570 oi->whence = OI_LOOSE;
5b086407 2571 return 0;
9a490590 2572 }
ddd63e64
SG
2573
2574 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 2575 reprepare_packed_git();
1f7117ef 2576 if (!find_pack_entry(real, &e))
052fe5ea 2577 return -1;
f0df4ed5 2578 }
3d77d877 2579
23c339c0 2580 rtype = packed_object_info(e.p, e.offset, oi);
412916ee 2581 if (rtype < 0) {
1f7117ef
CC
2582 mark_bad_packed_object(e.p, real);
2583 return sha1_object_info_extended(real, oi, 0);
5266d369
JH
2584 } else if (in_delta_base_cache(e.p, e.offset)) {
2585 oi->whence = OI_DBCACHED;
9a490590
JH
2586 } else {
2587 oi->whence = OI_PACKED;
2588 oi->u.packed.offset = e.offset;
2589 oi->u.packed.pack = e.p;
2590 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2591 rtype == OBJ_OFS_DELTA);
3d77d877
NP
2592 }
2593
5b086407 2594 return 0;
f0df4ed5
JS
2595}
2596
3fc0dca9 2597/* returns enum object_type or negative */
9a490590
JH
2598int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2599{
5b086407 2600 enum object_type type;
d099b717 2601 struct object_info oi = {NULL};
9a490590 2602
5b086407 2603 oi.typep = &type;
9a490590 2604 oi.sizep = sizep;
de7b5d62 2605 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
5b086407
JK
2606 return -1;
2607 return type;
9a490590
JH
2608}
2609
21666f1a
NP
2610static void *read_packed_sha1(const unsigned char *sha1,
2611 enum object_type *type, unsigned long *size)
1f688557
JH
2612{
2613 struct pack_entry e;
8eca0b47 2614 void *data;
1f688557 2615
cd673c1f 2616 if (!find_pack_entry(sha1, &e))
1f688557 2617 return NULL;
8eca0b47
NP
2618 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2619 if (!data) {
2620 /*
2621 * We're probably in deep shit, but let's try to fetch
2622 * the required object anyway from another pack or loose.
2623 * This should happen only in the presence of a corrupted
2624 * pack, and is better than failing outright.
2625 */
2626 error("failed to read object %s at offset %"PRIuMAX" from %s",
2627 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2628 mark_bad_packed_object(e.p, sha1);
ac939109 2629 data = read_object(sha1, type, size);
8eca0b47
NP
2630 }
2631 return data;
1f688557
JH
2632}
2633
21666f1a
NP
2634int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2635 unsigned char *sha1)
d66b37bb
JH
2636{
2637 struct cached_object *co;
2638
21666f1a 2639 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2640 if (has_sha1_file(sha1) || find_cached_object(sha1))
2641 return 0;
c7353967 2642 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
d66b37bb
JH
2643 co = &cached_objects[cached_object_nr++];
2644 co->size = len;
21666f1a 2645 co->type = type;
efa13f7b
JH
2646 co->buf = xmalloc(len);
2647 memcpy(co->buf, buf, len);
d66b37bb
JH
2648 hashcpy(co->sha1, sha1);
2649 return 0;
2650}
2651
c2c5b270
CC
2652static void *read_object(const unsigned char *sha1, enum object_type *type,
2653 unsigned long *size)
0fcfd160
LT
2654{
2655 unsigned long mapsize;
2656 void *map, *buf;
d66b37bb
JH
2657 struct cached_object *co;
2658
2659 co = find_cached_object(sha1);
2660 if (co) {
21666f1a 2661 *type = co->type;
d66b37bb 2662 *size = co->size;
182af834 2663 return xmemdupz(co->buf, co->size);
d66b37bb 2664 }
0fcfd160 2665
8276c007
PE
2666 buf = read_packed_sha1(sha1, type, size);
2667 if (buf)
2668 return buf;
bb6b8e4f 2669 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2670 if (map) {
7efbff75 2671 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2672 munmap(map, mapsize);
2673 return buf;
2674 }
637cdd9d 2675 reprepare_packed_git();
8276c007 2676 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2677}
2678
b6c4cecc
JH
2679/*
2680 * This function dies on corrupt objects; the callers who want to
2681 * deal with them should arrange to call read_object() and give error
2682 * messages themselves.
2683 */
5bf29b95
JH
2684void *read_sha1_file_extended(const unsigned char *sha1,
2685 enum object_type *type,
2686 unsigned long *size,
2687 unsigned flag)
ac939109 2688{
3ba7a065 2689 void *data;
b6c4cecc 2690 const struct packed_git *p;
bf93eea0 2691 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
b6c4cecc 2692
3ba7a065
JH
2693 errno = 0;
2694 data = read_object(repl, type, size);
4bbf5a26 2695 if (data)
b6c4cecc 2696 return data;
68095570 2697
25f3af3f 2698 if (errno && errno != ENOENT)
3ba7a065
JH
2699 die_errno("failed to read object %s", sha1_to_hex(sha1));
2700
68095570 2701 /* die if we replaced an object with one that does not exist */
b6c4cecc 2702 if (repl != sha1)
68095570
CC
2703 die("replacement %s not found for %s",
2704 sha1_to_hex(repl), sha1_to_hex(sha1));
2705
b6c4cecc 2706 if (has_loose_object(repl)) {
30d6c6ea
MH
2707 const char *path = sha1_file_name(sha1);
2708
b6c4cecc
JH
2709 die("loose object %s (stored in %s) is corrupt",
2710 sha1_to_hex(repl), path);
e8b15e61 2711 }
68095570 2712
b6c4cecc
JH
2713 if ((p = has_packed_and_bad(repl)) != NULL)
2714 die("packed object %s (stored in %s) is corrupt",
2715 sha1_to_hex(repl), p->pack_name);
f5552aee 2716
b6c4cecc 2717 return NULL;
ac939109
NP
2718}
2719
40469ee9 2720void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2721 const char *required_type_name,
40469ee9
JH
2722 unsigned long *size,
2723 unsigned char *actual_sha1_return)
f4913f91 2724{
21666f1a 2725 enum object_type type, required_type;
f4913f91
JH
2726 void *buffer;
2727 unsigned long isize;
40469ee9 2728 unsigned char actual_sha1[20];
f4913f91 2729
21666f1a 2730 required_type = type_from_string(required_type_name);
e702496e 2731 hashcpy(actual_sha1, sha1);
40469ee9
JH
2732 while (1) {
2733 int ref_length = -1;
2734 const char *ref_type = NULL;
f4913f91 2735
21666f1a 2736 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2737 if (!buffer)
2738 return NULL;
21666f1a 2739 if (type == required_type) {
40469ee9
JH
2740 *size = isize;
2741 if (actual_sha1_return)
e702496e 2742 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2743 return buffer;
2744 }
2745 /* Handle references */
21666f1a 2746 else if (type == OBJ_COMMIT)
40469ee9 2747 ref_type = "tree ";
21666f1a 2748 else if (type == OBJ_TAG)
40469ee9
JH
2749 ref_type = "object ";
2750 else {
2751 free(buffer);
2752 return NULL;
2753 }
2754 ref_length = strlen(ref_type);
f4913f91 2755
50974ec9
MK
2756 if (ref_length + 40 > isize ||
2757 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2758 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2759 free(buffer);
2760 return NULL;
2761 }
1cf58e72 2762 free(buffer);
40469ee9
JH
2763 /* Now we have the ID of the referred-to object in
2764 * actual_sha1. Check again. */
f4913f91 2765 }
f4913f91
JH
2766}
2767
ce9fbf16 2768static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2769 const char *type, unsigned char *sha1,
d65a16f6 2770 char *hdr, int *hdrlen)
d410c0f5 2771{
9126f009 2772 git_SHA_CTX c;
d410c0f5
JH
2773
2774 /* Generate the header */
d65a16f6 2775 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2776
2777 /* Sha1.. */
9126f009
NP
2778 git_SHA1_Init(&c);
2779 git_SHA1_Update(&c, hdr, *hdrlen);
2780 git_SHA1_Update(&c, buf, len);
2781 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2782}
2783
230f1322 2784/*
5a688fe4
JH
2785 * Move the just written object into its final resting place.
2786 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2787 * "moving" is only a part of what it does, when no patch between
2788 * master to pu changes the call sites of this function.
230f1322 2789 */
839837b9 2790int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2791{
e32c0a9c 2792 int ret = 0;
5a688fe4 2793
348df166 2794 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
2795 goto try_rename;
2796 else if (link(tmpfile, filename))
e32c0a9c 2797 ret = errno;
7ebb6fca
LT
2798
2799 /*
2800 * Coda hack - coda doesn't like cross-directory links,
2801 * so we fall back to a rename, which will mean that it
2802 * won't be able to check collisions, but that's not a
2803 * big deal.
2804 *
2805 * The same holds for FAT formatted media.
2806 *
3be1f18e 2807 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
2808 * left to unlink.
2809 */
2810 if (ret && ret != EEXIST) {
be66a6c4 2811 try_rename:
7ebb6fca 2812 if (!rename(tmpfile, filename))
3be1f18e 2813 goto out;
9e48b389 2814 ret = errno;
230f1322 2815 }
691f1a28 2816 unlink_or_warn(tmpfile);
230f1322
LT
2817 if (ret) {
2818 if (ret != EEXIST) {
82247e9b 2819 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
230f1322
LT
2820 }
2821 /* FIXME!!! Collision check here ? */
2822 }
2823
3be1f18e 2824out:
5256b006 2825 if (adjust_shared_perm(filename))
5a688fe4 2826 return error("unable to set permission to '%s'", filename);
230f1322
LT
2827 return 0;
2828}
2829
4d548150
LT
2830static int write_buffer(int fd, const void *buf, size_t len)
2831{
d34cf19b 2832 if (write_in_full(fd, buf, len) < 0)
93822c22 2833 return error("file write error (%s)", strerror(errno));
4d548150
LT
2834 return 0;
2835}
2836
ce9fbf16 2837int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2838 unsigned char *sha1)
2839{
d65a16f6 2840 char hdr[32];
abdc3fc8
RS
2841 int hdrlen;
2842 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2843 return 0;
2844}
2845
e9039dd3
LT
2846/* Finalize a file on disk, and close it. */
2847static void close_sha1_file(int fd)
2848{
aafe9fba
LT
2849 if (fsync_object_files)
2850 fsync_or_die(fd, "sha1 file");
e9039dd3 2851 if (close(fd) != 0)
d824cbba 2852 die_errno("error when closing sha1 file");
e9039dd3
LT
2853}
2854
5723fe7e
LT
2855/* Size of directory component, including the ending '/' */
2856static inline int directory_size(const char *filename)
2857{
2858 const char *s = strrchr(filename, '/');
2859 if (!s)
2860 return 0;
2861 return s - filename + 1;
2862}
2863
2864/*
2865 * This creates a temporary file in the same directory as the final
2866 * 'filename'
2867 *
2868 * We want to avoid cross-directory filename renames, because those
2869 * can have problems on various filesystems (FAT, NFS, Coda).
2870 */
2871static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2872{
2873 int fd, dirlen = directory_size(filename);
2874
2875 if (dirlen + 20 > bufsiz) {
2876 errno = ENAMETOOLONG;
2877 return -1;
2878 }
2879 memcpy(buffer, filename, dirlen);
2880 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
5256b006 2881 fd = git_mkstemp_mode(buffer, 0444);
cbacbf4e 2882 if (fd < 0 && dirlen && errno == ENOENT) {
5723fe7e 2883 /* Make sure the directory exists */
6ff6af62 2884 memcpy(buffer, filename, dirlen);
5723fe7e 2885 buffer[dirlen-1] = 0;
b2476a60
JH
2886 if (mkdir(buffer, 0777) && errno != EEXIST)
2887 return -1;
2888 if (adjust_shared_perm(buffer))
5723fe7e
LT
2889 return -1;
2890
2891 /* Try again */
2892 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
5256b006 2893 fd = git_mkstemp_mode(buffer, 0444);
5723fe7e
LT
2894 }
2895 return fd;
2896}
2897
bbac7311 2898static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 2899 const void *buf, unsigned long len, time_t mtime)
0fcfd160 2900{
915308b1 2901 int fd, ret;
9892beba 2902 unsigned char compressed[4096];
ef49a7a0 2903 git_zstream stream;
748af44c
NP
2904 git_SHA_CTX c;
2905 unsigned char parano_sha1[20];
ab1900a3 2906 static char tmp_file[PATH_MAX];
30d6c6ea 2907 const char *filename = sha1_file_name(sha1);
a44c9a5e 2908
ab1900a3 2909 fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
aac17941 2910 if (fd < 0) {
35243577 2911 if (errno == EACCES)
82247e9b 2912 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 2913 else
5eaeda70 2914 return error("unable to create temporary file: %s", strerror(errno));
aac17941
LT
2915 }
2916
0fcfd160
LT
2917 /* Set it up */
2918 memset(&stream, 0, sizeof(stream));
55bb5c91 2919 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 2920 stream.next_out = compressed;
9892beba 2921 stream.avail_out = sizeof(compressed);
748af44c 2922 git_SHA1_Init(&c);
a44c9a5e
LT
2923
2924 /* First header.. */
d65a16f6 2925 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2926 stream.avail_in = hdrlen;
55bb5c91
JH
2927 while (git_deflate(&stream, 0) == Z_OK)
2928 ; /* nothing */
748af44c 2929 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
2930
2931 /* Then the data itself.. */
c00e657d 2932 stream.next_in = (void *)buf;
a44c9a5e 2933 stream.avail_in = len;
9892beba 2934 do {
748af44c 2935 unsigned char *in0 = stream.next_in;
55bb5c91 2936 ret = git_deflate(&stream, Z_FINISH);
748af44c 2937 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
2938 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2939 die("unable to write sha1 file");
2940 stream.next_out = compressed;
2941 stream.avail_out = sizeof(compressed);
2942 } while (ret == Z_OK);
2943
ac54c277
LT
2944 if (ret != Z_STREAM_END)
2945 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 2946 ret = git_deflate_end_gently(&stream);
ac54c277
LT
2947 if (ret != Z_OK)
2948 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
2949 git_SHA1_Final(parano_sha1, &c);
2950 if (hashcmp(sha1, parano_sha1) != 0)
2951 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 2952
e9039dd3 2953 close_sha1_file(fd);
0fcfd160 2954
bbac7311
NP
2955 if (mtime) {
2956 struct utimbuf utb;
2957 utb.actime = mtime;
2958 utb.modtime = mtime;
ab1900a3 2959 if (utime(tmp_file, &utb) < 0)
bbac7311 2960 warning("failed utime() on %s: %s",
ab1900a3 2961 tmp_file, strerror(errno));
bbac7311
NP
2962 }
2963
ab1900a3 2964 return move_temp_to_file(tmp_file, filename);
0fcfd160 2965}
8237b185 2966
c00e657d 2967int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
bbac7311
NP
2968{
2969 unsigned char sha1[20];
2970 char hdr[32];
2971 int hdrlen;
2972
2973 /* Normally if we have it in the pack then we do not bother writing
2974 * it out into .git/objects/??/?{38} file.
2975 */
2976 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2977 if (returnsha1)
2978 hashcpy(returnsha1, sha1);
2979 if (has_sha1_file(sha1))
2980 return 0;
2981 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2982}
2983
2984int force_object_loose(const unsigned char *sha1, time_t mtime)
2985{
bbac7311
NP
2986 void *buf;
2987 unsigned long len;
2988 enum object_type type;
2989 char hdr[32];
2990 int hdrlen;
1fb23e65 2991 int ret;
bbac7311 2992
c529d75a 2993 if (has_loose_object(sha1))
bbac7311
NP
2994 return 0;
2995 buf = read_packed_sha1(sha1, &type, &len);
2996 if (!buf)
2997 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2998 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1fb23e65
BS
2999 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3000 free(buf);
3001
3002 return ret;
bbac7311
NP
3003}
3004
bf592c50
DB
3005int has_pack_index(const unsigned char *sha1)
3006{
3007 struct stat st;
3008 if (stat(sha1_pack_index_name(sha1), &st))
3009 return 0;
3010 return 1;
bf592c50
DB
3011}
3012
cd673c1f
JH
3013int has_sha1_pack(const unsigned char *sha1)
3014{
3015 struct pack_entry e;
3016 return find_pack_entry(sha1, &e);
3017}
3018
8237b185
DB
3019int has_sha1_file(const unsigned char *sha1)
3020{
1f688557
JH
3021 struct pack_entry e;
3022
cd673c1f 3023 if (find_pack_entry(sha1, &e))
1f688557 3024 return 1;
45e8a748
JK
3025 if (has_loose_object(sha1))
3026 return 1;
3027 reprepare_packed_git();
3028 return find_pack_entry(sha1, &e);
8237b185 3029}
74400e71 3030
c879daa2
NTND
3031static void check_tree(const void *buf, size_t size)
3032{
3033 struct tree_desc desc;
3034 struct name_entry entry;
3035
3036 init_tree_desc(&desc, buf, size);
3037 while (tree_entry(&desc, &entry))
3038 /* do nothing
3039 * tree_entry() will die() on malformed entries */
3040 ;
3041}
3042
3043static void check_commit(const void *buf, size_t size)
3044{
3045 struct commit c;
3046 memset(&c, 0, sizeof(c));
3047 if (parse_commit_buffer(&c, buf, size))
3048 die("corrupt commit");
3049}
3050
3051static void check_tag(const void *buf, size_t size)
3052{
3053 struct tag t;
3054 memset(&t, 0, sizeof(t));
3055 if (parse_tag_buffer(&t, buf, size))
3056 die("corrupt tag");
3057}
3058
43df4f86 3059static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
3060 enum object_type type,
3061 const char *path, unsigned flags)
e7332f96 3062{
6c510bee 3063 int ret, re_allocated = 0;
c4ce46fc 3064 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 3065
7672db20 3066 if (!type)
edaec3fb 3067 type = OBJ_BLOB;
6c510bee
LT
3068
3069 /*
3070 * Convert blobs to git internal format
3071 */
43df4f86 3072 if ((type == OBJ_BLOB) && path) {
f285a2d7 3073 struct strbuf nbuf = STRBUF_INIT;
21e5ad50 3074 if (convert_to_git(path, buf, size, &nbuf,
5e12e78e 3075 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 3076 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
3077 re_allocated = 1;
3078 }
3079 }
c4ce46fc 3080 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
3081 if (type == OBJ_TREE)
3082 check_tree(buf, size);
3083 if (type == OBJ_COMMIT)
3084 check_commit(buf, size);
3085 if (type == OBJ_TAG)
3086 check_tag(buf, size);
3087 }
6c510bee 3088
7672db20 3089 if (write_object)
edaec3fb 3090 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 3091 else
edaec3fb 3092 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 3093 if (re_allocated)
6c510bee 3094 free(buf);
43df4f86
DP
3095 return ret;
3096}
3097
7b41e1e1
JH
3098static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3099 const char *path, unsigned flags)
3100{
3101 struct strbuf sbuf = STRBUF_INIT;
3102 int ret;
3103
3104 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3105 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3106 else
3107 ret = -1;
3108 strbuf_release(&sbuf);
3109 return ret;
3110}
3111
ea68b0ce
DP
3112#define SMALL_FILE_SIZE (32*1024)
3113
7b41e1e1
JH
3114static int index_core(unsigned char *sha1, int fd, size_t size,
3115 enum object_type type, const char *path,
3116 unsigned flags)
43df4f86
DP
3117{
3118 int ret;
43df4f86 3119
7b41e1e1 3120 if (!size) {
c4ce46fc 3121 ret = index_mem(sha1, NULL, size, type, path, flags);
ea68b0ce
DP
3122 } else if (size <= SMALL_FILE_SIZE) {
3123 char *buf = xmalloc(size);
3124 if (size == read_in_full(fd, buf, size))
c4ce46fc 3125 ret = index_mem(sha1, buf, size, type, path, flags);
ea68b0ce
DP
3126 else
3127 ret = error("short read %s", strerror(errno));
3128 free(buf);
08bda208 3129 } else {
43df4f86 3130 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
c4ce46fc 3131 ret = index_mem(sha1, buf, size, type, path, flags);
aac17941 3132 munmap(buf, size);
08bda208 3133 }
7b41e1e1
JH
3134 return ret;
3135}
3136
4dd1fbc7 3137/*
568508e7
JH
3138 * This creates one packfile per large blob unless bulk-checkin
3139 * machinery is "plugged".
4dd1fbc7
JH
3140 *
3141 * This also bypasses the usual "convert-to-git" dance, and that is on
3142 * purpose. We could write a streaming version of the converting
3143 * functions and insert that before feeding the data to fast-import
4f22b101
JK
3144 * (or equivalent in-core API described above). However, that is
3145 * somewhat complicated, as we do not know the size of the filter
3146 * result, which we need to know beforehand when writing a git object.
3147 * Since the primary motivation for trying to stream from the working
3148 * tree file and to avoid mmaping it in core is to deal with large
3149 * binary blobs, they generally do not want to get any conversion, and
3150 * callers should avoid this code path when filters are requested.
4dd1fbc7
JH
3151 */
3152static int index_stream(unsigned char *sha1, int fd, size_t size,
3153 enum object_type type, const char *path,
3154 unsigned flags)
3155{
568508e7 3156 return index_bulk_checkin(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
3157}
3158
7b41e1e1
JH
3159int index_fd(unsigned char *sha1, int fd, struct stat *st,
3160 enum object_type type, const char *path, unsigned flags)
3161{
3162 int ret;
3163 size_t size = xsize_t(st->st_size);
3164
3165 if (!S_ISREG(st->st_mode))
3166 ret = index_pipe(sha1, fd, type, path, flags);
4f22b101
JK
3167 else if (size <= big_file_threshold || type != OBJ_BLOB ||
3168 (path && would_convert_to_git(path, NULL, 0, 0)))
7b41e1e1 3169 ret = index_core(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
3170 else
3171 ret = index_stream(sha1, fd, size, type, path, flags);
43df4f86 3172 close(fd);
aac17941 3173 return ret;
74400e71 3174}
ec1fcc16 3175
c4ce46fc 3176int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
ec1fcc16
JH
3177{
3178 int fd;
b760d3aa 3179 struct strbuf sb = STRBUF_INIT;
ec1fcc16
JH
3180
3181 switch (st->st_mode & S_IFMT) {
3182 case S_IFREG:
3183 fd = open(path, O_RDONLY);
3184 if (fd < 0)
3185 return error("open(\"%s\"): %s", path,
3186 strerror(errno));
c4ce46fc 3187 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
ec1fcc16
JH
3188 return error("%s: failed to insert into database",
3189 path);
3190 break;
3191 case S_IFLNK:
b760d3aa 3192 if (strbuf_readlink(&sb, path, st->st_size)) {
ec1fcc16 3193 char *errstr = strerror(errno);
ec1fcc16
JH
3194 return error("readlink(\"%s\"): %s", path,
3195 errstr);
3196 }
c4ce46fc 3197 if (!(flags & HASH_WRITE_OBJECT))
b760d3aa
LT
3198 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3199 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
ec1fcc16
JH
3200 return error("%s: failed to insert into database",
3201 path);
b760d3aa 3202 strbuf_release(&sb);
ec1fcc16 3203 break;
f35a6d3b
LT
3204 case S_IFDIR:
3205 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
3206 default:
3207 return error("%s: unsupported file type", path);
3208 }
3209 return 0;
3210}
a69e5429
JH
3211
3212int read_pack_header(int fd, struct pack_header *header)
3213{
c697ad14
HO
3214 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3215 /* "eof before pack header was fully read" */
3216 return PH_ERROR_EOF;
3217
a69e5429
JH
3218 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3219 /* "protocol error (pack signature mismatch detected)" */
3220 return PH_ERROR_PACK_SIGNATURE;
3221 if (!pack_version_ok(header->hdr_version))
3222 /* "protocol error (pack version unsupported)" */
3223 return PH_ERROR_PROTOCOL;
3224 return 0;
3225}
40d52ff7
JK
3226
3227void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3228{
3229 enum object_type type = sha1_object_info(sha1, NULL);
3230 if (type < 0)
3231 die("%s is not a valid object", sha1_to_hex(sha1));
3232 if (type != expect)
3233 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3234 typename(expect));
3235}