Add const to parse_{commit,tag}_buffer()
[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"
1f688557 10#include "delta.h"
a733cb60 11#include "pack.h"
8e440259
PE
12#include "blob.h"
13#include "commit.h"
14#include "tag.h"
15#include "tree.h"
f35a6d3b 16#include "refs.h"
70f5d5d3 17#include "pack-revindex.h"
628522ec 18#include "sha1-lookup.h"
0fcfd160 19
144bde78
LT
20#ifndef O_NOATIME
21#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
22#define O_NOATIME 01000000
23#else
24#define O_NOATIME 0
25#endif
26#endif
27
e05db0fd
PR
28#ifdef NO_C99_FORMAT
29#define SZ_FMT "lu"
9e42d6a1 30static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
e05db0fd
PR
31#else
32#define SZ_FMT "zu"
9e42d6a1 33static size_t sz_fmt(size_t s) { return s; }
e05db0fd
PR
34#endif
35
96f1e58f 36const unsigned char null_sha1[20];
88cd621d 37
f2e872aa 38static int git_open_noatime(const char *name, struct packed_git *p);
4865d2b6 39
b2cb9425
JH
40int safe_create_leading_directories(char *path)
41{
8385abfd 42 char *pos = path + offset_1st_component(path);
67d42212
JR
43 struct stat st;
44
b2cb9425
JH
45 while (pos) {
46 pos = strchr(pos, '/');
47 if (!pos)
48 break;
5f0bdf50
JH
49 while (*++pos == '/')
50 ;
51 if (!*pos)
52 break;
53 *--pos = '\0';
67d42212
JR
54 if (!stat(path, &st)) {
55 /* path exists */
56 if (!S_ISDIR(st.st_mode)) {
b2cb9425 57 *pos = '/';
67d42212 58 return -3;
b2cb9425 59 }
457f06d6 60 }
67d42212
JR
61 else if (mkdir(path, 0777)) {
62 *pos = '/';
63 return -1;
64 }
457f06d6
JS
65 else if (adjust_shared_perm(path)) {
66 *pos = '/';
67 return -2;
68 }
b2cb9425
JH
69 *pos++ = '/';
70 }
71 return 0;
72}
723c31fe 73
8e21d63b
JK
74int safe_create_leading_directories_const(const char *path)
75{
76 /* path points to cache entries, so xstrdup before messing with it */
77 char *buf = xstrdup(path);
78 int result = safe_create_leading_directories(buf);
79 free(buf);
80 return result;
81}
82
ace1534d
JH
83static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
84{
85 int i;
86 for (i = 0; i < 20; i++) {
87 static char hex[] = "0123456789abcdef";
88 unsigned int val = sha1[i];
89 char *pos = pathbuf + i*2 + (i > 0);
90 *pos++ = hex[val >> 4];
91 *pos = hex[val & 0xf];
92 }
93}
94
0fcfd160
LT
95/*
96 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 97 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 98 * filename.
ace1534d
JH
99 *
100 * Also note that this returns the location for creating. Reading
101 * SHA1 file can happen from any alternate directory listed in the
d19938ab 102 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 103 * the primary object database.
0fcfd160
LT
104 */
105char *sha1_file_name(const unsigned char *sha1)
106{
560fb6a1
JK
107 static char buf[PATH_MAX];
108 const char *objdir;
109 int len;
0fcfd160 110
560fb6a1
JK
111 objdir = get_object_directory();
112 len = strlen(objdir);
113
114 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
115 if (len + 43 > PATH_MAX)
116 die("insanely long object directory %s", objdir);
117 memcpy(buf, objdir, len);
118 buf[len] = '/';
119 buf[len+3] = '/';
120 buf[len+42] = '\0';
121 fill_sha1_path(buf + len + 1, sha1);
122 return buf;
0fcfd160
LT
123}
124
633f43e1 125static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 126 char **name, char **base, const char *which)
bf592c50
DB
127{
128 static const char hex[] = "0123456789abcdef";
633f43e1 129 char *buf;
bf592c50
DB
130 int i;
131
633f43e1 132 if (!*base) {
bf592c50
DB
133 const char *sha1_file_directory = get_object_directory();
134 int len = strlen(sha1_file_directory);
633f43e1 135 *base = xmalloc(len + 60);
6eec46bd
JH
136 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
137 sha1_file_directory, which);
633f43e1 138 *name = *base + len + 11;
bf592c50
DB
139 }
140
633f43e1 141 buf = *name;
bf592c50
DB
142
143 for (i = 0; i < 20; i++) {
144 unsigned int val = *sha1++;
145 *buf++ = hex[val >> 4];
146 *buf++ = hex[val & 0xf];
147 }
a6080a0a 148
633f43e1 149 return *base;
bf592c50
DB
150}
151
633f43e1 152char *sha1_pack_name(const unsigned char *sha1)
bf592c50 153{
633f43e1 154 static char *name, *base;
bf592c50 155
6eec46bd 156 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 157}
bf592c50 158
633f43e1
HO
159char *sha1_pack_index_name(const unsigned char *sha1)
160{
161 static char *name, *base;
a6080a0a 162
6eec46bd 163 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
164}
165
d5a63b99
JH
166struct alternate_object_database *alt_odb_list;
167static struct alternate_object_database **alt_odb_tail;
ace1534d 168
c2f493a4
MW
169static void read_info_alternates(const char * alternates, int depth);
170
ddd5d056
JH
171/*
172 * Prepare alternate object database registry.
d5a63b99
JH
173 *
174 * The variable alt_odb_list points at the list of struct
175 * alternate_object_database. The elements on this list come from
176 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
177 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
178 * whose contents is similar to that environment variable but can be
179 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
180 * contains "/the/directory/corresponding/to/.git/objects/...", while
181 * its name points just after the slash at the end of ".git/objects/"
182 * in the example above, and has enough space to hold 40-byte hex
183 * SHA1, an extra slash for the first level indirection, and the
184 * terminating NUL.
ddd5d056 185 */
c2f493a4 186static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 187{
1494e038 188 const char *objdir = get_object_directory();
c2f493a4
MW
189 struct alternate_object_database *ent;
190 struct alternate_object_database *alt;
191 /* 43 = 40-byte + 2 '/' + terminating NUL */
192 int pfxlen = len;
193 int entlen = pfxlen + 43;
ccfd3e99 194 int base_len = -1;
d5a63b99 195
85dadc38 196 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
197 /* Relative alt-odb */
198 if (base_len < 0)
199 base_len = strlen(relative_base) + 1;
200 entlen += base_len;
201 pfxlen += base_len;
202 }
203 ent = xmalloc(sizeof(*ent) + entlen);
204
85dadc38 205 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
206 memcpy(ent->base, relative_base, base_len - 1);
207 ent->base[base_len - 1] = '/';
208 memcpy(ent->base + base_len, entry, len);
209 }
210 else
211 memcpy(ent->base, entry, pfxlen);
212
213 ent->name = ent->base + pfxlen + 1;
214 ent->base[pfxlen + 3] = '/';
215 ent->base[pfxlen] = ent->base[entlen-1] = 0;
216
217 /* Detect cases where alternate disappeared */
90b4a71c 218 if (!is_directory(ent->base)) {
c2f493a4
MW
219 error("object directory %s does not exist; "
220 "check .git/objects/info/alternates.",
221 ent->base);
222 free(ent);
223 return -1;
224 }
225
226 /* Prevent the common mistake of listing the same
227 * thing twice, or object directory itself.
228 */
229 for (alt = alt_odb_list; alt; alt = alt->next) {
230 if (!memcmp(ent->base, alt->base, pfxlen)) {
231 free(ent);
232 return -1;
233 }
234 }
235 if (!memcmp(ent->base, objdir, pfxlen)) {
236 free(ent);
237 return -1;
238 }
239
240 /* add the alternate entry */
241 *alt_odb_tail = ent;
242 alt_odb_tail = &(ent->next);
243 ent->next = NULL;
244
245 /* recursively add alternates */
246 read_info_alternates(ent->base, depth + 1);
247
248 ent->base[pfxlen] = '/';
249
250 return 0;
251}
252
253static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
254 const char *relative_base, int depth)
255{
256 const char *cp, *last;
257
258 if (depth > 5) {
259 error("%s: ignoring alternate object stores, nesting too deep.",
260 relative_base);
261 return;
262 }
263
d5a63b99 264 last = alt;
9577e7e3
JH
265 while (last < ep) {
266 cp = last;
267 if (cp < ep && *cp == '#') {
268 while (cp < ep && *cp != sep)
269 cp++;
270 last = cp + 1;
271 continue;
272 }
c2f493a4
MW
273 while (cp < ep && *cp != sep)
274 cp++;
d5a63b99 275 if (last != cp) {
85dadc38 276 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
277 error("%s: ignoring relative alternate object store %s",
278 relative_base, last);
279 } else {
280 link_alt_odb_entry(last, cp - last,
281 relative_base, depth);
1494e038 282 }
d5a63b99 283 }
9577e7e3 284 while (cp < ep && *cp == sep)
d5a63b99
JH
285 cp++;
286 last = cp;
9577e7e3 287 }
d5a63b99
JH
288}
289
c2f493a4 290static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 291{
9577e7e3 292 char *map;
dc49cd76 293 size_t mapsz;
d5a63b99 294 struct stat st;
9cb18f56
JM
295 const char alt_file_name[] = "info/alternates";
296 /* Given that relative_base is no longer than PATH_MAX,
297 ensure that "path" has enough space to append "/", the
298 file name, "info/alternates", and a trailing NUL. */
299 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 300 int fd;
d5a63b99 301
9cb18f56 302 sprintf(path, "%s/%s", relative_base, alt_file_name);
f2e872aa 303 fd = git_open_noatime(path, NULL);
d5a63b99
JH
304 if (fd < 0)
305 return;
306 if (fstat(fd, &st) || (st.st_size == 0)) {
307 close(fd);
9a217f2a 308 return;
ace1534d 309 }
dc49cd76
SP
310 mapsz = xsize_t(st.st_size);
311 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 312 close(fd);
d5a63b99 313
dc49cd76 314 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 315
dc49cd76 316 munmap(map, mapsz);
ace1534d
JH
317}
318
bef70b22
DB
319void add_to_alternates_file(const char *reference)
320{
321 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
acd3b9ec 322 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
bef70b22
DB
323 char *alt = mkpath("%s/objects\n", reference);
324 write_or_die(fd, alt, strlen(alt));
325 if (commit_lock_file(lock))
326 die("could not close alternates file");
327 if (alt_odb_tail)
328 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
329}
330
d79796bc
JH
331void foreach_alt_odb(alt_odb_fn fn, void *cb)
332{
333 struct alternate_object_database *ent;
334
335 prepare_alt_odb();
336 for (ent = alt_odb_list; ent; ent = ent->next)
337 if (fn(ent, cb))
338 return;
339}
340
c2f493a4
MW
341void prepare_alt_odb(void)
342{
554fe20d 343 const char *alt;
c2f493a4 344
7dc24aa5
SP
345 if (alt_odb_tail)
346 return;
347
c2f493a4
MW
348 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
349 if (!alt) alt = "";
350
c2f493a4 351 alt_odb_tail = &alt_odb_list;
80ba074f 352 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
353
354 read_info_alternates(get_object_directory(), 0);
355}
356
0f4dc14a 357static int has_loose_object_local(const unsigned char *sha1)
ace1534d 358{
ace1534d 359 char *name = sha1_file_name(sha1);
0f4dc14a
BC
360 return !access(name, F_OK);
361}
ace1534d 362
0f4dc14a
BC
363int has_loose_object_nonlocal(const unsigned char *sha1)
364{
365 struct alternate_object_database *alt;
9a217f2a 366 prepare_alt_odb();
d5a63b99 367 for (alt = alt_odb_list; alt; alt = alt->next) {
0f4dc14a 368 fill_sha1_path(alt->name, sha1);
c529d75a
LT
369 if (!access(alt->base, F_OK))
370 return 1;
ace1534d 371 }
c529d75a 372 return 0;
ace1534d
JH
373}
374
0f4dc14a
BC
375static int has_loose_object(const unsigned char *sha1)
376{
377 return has_loose_object_local(sha1) ||
378 has_loose_object_nonlocal(sha1);
379}
380
60bb8b14 381static unsigned int pack_used_ctr;
a53128b6
SP
382static unsigned int pack_mmap_calls;
383static unsigned int peak_pack_open_windows;
384static unsigned int pack_open_windows;
385static size_t peak_pack_mapped;
60bb8b14 386static size_t pack_mapped;
9a217f2a 387struct packed_git *packed_git;
1f688557 388
b79d18c9 389void pack_report(void)
a53128b6
SP
390{
391 fprintf(stderr,
e05db0fd
PR
392 "pack_report: getpagesize() = %10" SZ_FMT "\n"
393 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
394 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
395 sz_fmt(getpagesize()),
396 sz_fmt(packed_git_window_size),
397 sz_fmt(packed_git_limit));
a53128b6
SP
398 fprintf(stderr,
399 "pack_report: pack_used_ctr = %10u\n"
400 "pack_report: pack_mmap_calls = %10u\n"
401 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
402 "pack_report: pack_mapped = "
403 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
404 pack_used_ctr,
405 pack_mmap_calls,
406 pack_open_windows, peak_pack_open_windows,
9e42d6a1 407 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
408}
409
42873078 410static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
411{
412 void *idx_map;
42873078 413 struct pack_idx_header *hdr;
dc49cd76 414 size_t idx_size;
74e34e1f 415 uint32_t version, nr, i, *index;
f2e872aa 416 int fd = git_open_noatime(path, p);
1f688557 417 struct stat st;
42873078 418
1f688557
JH
419 if (fd < 0)
420 return -1;
421 if (fstat(fd, &st)) {
422 close(fd);
423 return -1;
424 }
dc49cd76 425 idx_size = xsize_t(st.st_size);
2d88451b
SP
426 if (idx_size < 4 * 256 + 20 + 20) {
427 close(fd);
428 return error("index file %s is too small", path);
429 }
c4712e45 430 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 431 close(fd);
1f688557 432
42873078
NP
433 hdr = idx_map;
434 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
435 version = ntohl(hdr->idx_version);
436 if (version < 2 || version > 2) {
437 munmap(idx_map, idx_size);
6e1c2344 438 return error("index file %s is version %"PRIu32
74e34e1f
NP
439 " and is not supported by this binary"
440 " (try upgrading GIT to a newer version)",
441 path, version);
442 }
443 } else
444 version = 1;
df1b059d 445
1f688557 446 nr = 0;
42873078 447 index = idx_map;
74e34e1f
NP
448 if (version > 1)
449 index += 2; /* skip index header */
1f688557 450 for (i = 0; i < 256; i++) {
326bf396 451 uint32_t n = ntohl(index[i]);
2d88451b
SP
452 if (n < nr) {
453 munmap(idx_map, idx_size);
df1b059d 454 return error("non-monotonic index %s", path);
2d88451b 455 }
1f688557
JH
456 nr = n;
457 }
458
74e34e1f
NP
459 if (version == 1) {
460 /*
461 * Total size:
462 * - 256 index entries 4 bytes each
463 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
464 * - 20-byte SHA1 of the packfile
465 * - 20-byte SHA1 file checksum
466 */
467 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
468 munmap(idx_map, idx_size);
eef427a0 469 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
470 }
471 } else if (version == 2) {
472 /*
473 * Minimum size:
474 * - 8 bytes of header
475 * - 256 index entries 4 bytes each
476 * - 20-byte sha1 entry * nr
477 * - 4-byte crc entry * nr
478 * - 4-byte offset entry * nr
479 * - 20-byte SHA1 of the packfile
480 * - 20-byte SHA1 file checksum
481 * And after the 4-byte offset table might be a
482 * variable sized table containing 8-byte entries
483 * for offsets larger than 2^31.
484 */
485 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
486 unsigned long max_size = min_size;
487 if (nr)
488 max_size += (nr - 1)*8;
489 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 490 munmap(idx_map, idx_size);
eef427a0 491 return error("wrong index v2 file size in %s", path);
74e34e1f 492 }
7109c889
JH
493 if (idx_size != min_size &&
494 /*
495 * make sure we can deal with large pack offsets.
496 * 31-bit signed offset won't be enough, neither
497 * 32-bit unsigned one will be.
498 */
499 (sizeof(off_t) <= 4)) {
500 munmap(idx_map, idx_size);
501 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 502 }
2d88451b 503 }
1f688557 504
74e34e1f 505 p->index_version = version;
42873078
NP
506 p->index_data = idx_map;
507 p->index_size = idx_size;
57059091 508 p->num_objects = nr;
1f688557
JH
509 return 0;
510}
511
bc8e478a 512int open_pack_index(struct packed_git *p)
d079837e
SP
513{
514 char *idx_name;
515 int ret;
516
517 if (p->index_data)
518 return 0;
519
520 idx_name = xstrdup(p->pack_name);
521 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
522 ret = check_packed_git_idx(idx_name, p);
523 free(idx_name);
524 return ret;
525}
526
11daf39b
SP
527static void scan_windows(struct packed_git *p,
528 struct packed_git **lru_p,
529 struct pack_window **lru_w,
530 struct pack_window **lru_l)
1f688557 531{
11daf39b
SP
532 struct pack_window *w, *w_l;
533
534 for (w_l = NULL, w = p->windows; w; w = w->next) {
535 if (!w->inuse_cnt) {
536 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
537 *lru_p = p;
538 *lru_w = w;
539 *lru_l = w_l;
54044bf8 540 }
54044bf8 541 }
11daf39b 542 w_l = w;
f9253394 543 }
11daf39b
SP
544}
545
d1efefa4 546static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
547{
548 struct packed_git *p, *lru_p = NULL;
549 struct pack_window *lru_w = NULL, *lru_l = NULL;
550
551 if (current)
552 scan_windows(current, &lru_p, &lru_w, &lru_l);
553 for (p = packed_git; p; p = p->next)
554 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
555 if (lru_p) {
556 munmap(lru_w->base, lru_w->len);
557 pack_mapped -= lru_w->len;
558 if (lru_l)
559 lru_l->next = lru_w->next;
560 else {
561 lru_p->windows = lru_w->next;
d1efefa4 562 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
563 close(lru_p->pack_fd);
564 lru_p->pack_fd = -1;
565 }
566 }
567 free(lru_w);
a53128b6 568 pack_open_windows--;
54044bf8
SP
569 return 1;
570 }
571 return 0;
f9253394
JH
572}
573
d1efefa4 574void release_pack_memory(size_t need, int fd)
97bfeb34
SP
575{
576 size_t cur = pack_mapped;
d1efefa4 577 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
578 ; /* nothing */
579}
580
58ecbd5e
JN
581void *xmmap(void *start, size_t length,
582 int prot, int flags, int fd, off_t offset)
583{
584 void *ret = mmap(start, length, prot, flags, fd, offset);
585 if (ret == MAP_FAILED) {
586 if (!length)
587 return NULL;
588 release_pack_memory(length, fd);
589 ret = mmap(start, length, prot, flags, fd, offset);
590 if (ret == MAP_FAILED)
591 die_errno("Out of memory? mmap failed");
592 }
593 return ret;
594}
595
c9ced051
SP
596void close_pack_windows(struct packed_git *p)
597{
598 while (p->windows) {
599 struct pack_window *w = p->windows;
600
601 if (w->inuse_cnt)
602 die("pack '%s' still has open windows to it",
603 p->pack_name);
604 munmap(w->base, w->len);
605 pack_mapped -= w->len;
606 pack_open_windows--;
607 p->windows = w->next;
608 free(w);
609 }
610}
611
03e79c88 612void unuse_pack(struct pack_window **w_cursor)
f9253394 613{
03e79c88
SP
614 struct pack_window *w = *w_cursor;
615 if (w) {
616 w->inuse_cnt--;
617 *w_cursor = NULL;
618 }
1f688557
JH
619}
620
fa5fc15d
SP
621void close_pack_index(struct packed_git *p)
622{
623 if (p->index_data) {
624 munmap((void *)p->index_data, p->index_size);
625 p->index_data = NULL;
626 }
627}
628
c74faea1
NP
629/*
630 * This is used by git-repack in case a newly created pack happens to
631 * contain the same set of objects as an existing one. In that case
632 * the resulting file might be different even if its name would be the
633 * same. It is best to close any reference to the old pack before it is
634 * replaced on disk. Of course no index pointers nor windows for given pack
635 * must subsist at this point. If ever objects from this pack are requested
636 * again, the new version of the pack will be reinitialized through
637 * reprepare_packed_git().
638 */
639void free_pack_by_name(const char *pack_name)
640{
641 struct packed_git *p, **pp = &packed_git;
642
643 while (*pp) {
644 p = *pp;
645 if (strcmp(pack_name, p->pack_name) == 0) {
fa3a0c94 646 clear_delta_base_cache();
c74faea1
NP
647 close_pack_windows(p);
648 if (p->pack_fd != -1)
649 close(p->pack_fd);
fa5fc15d 650 close_pack_index(p);
c74faea1
NP
651 free(p->bad_object_sha1);
652 *pp = p->next;
653 free(p);
654 return;
655 }
656 pp = &p->next;
657 }
658}
659
3cf8b462
SP
660/*
661 * Do not call this directly as this leaks p->pack_fd on error return;
662 * call open_packed_git() instead.
663 */
664static int open_packed_git_1(struct packed_git *p)
1f688557 665{
9bc879c1
SP
666 struct stat st;
667 struct pack_header hdr;
668 unsigned char sha1[20];
669 unsigned char *idx_sha1;
2c039da8 670 long fd_flag;
9bc879c1 671
d079837e
SP
672 if (!p->index_data && open_pack_index(p))
673 return error("packfile %s index unavailable", p->pack_name);
674
f2e872aa 675 p->pack_fd = git_open_noatime(p->pack_name, p);
9bc879c1 676 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 677 return -1;
9bc879c1
SP
678
679 /* If we created the struct before we had the pack we lack size. */
bf592c50 680 if (!p->pack_size) {
bf592c50 681 if (!S_ISREG(st.st_mode))
072db278 682 return error("packfile %s not a regular file", p->pack_name);
bf592c50 683 p->pack_size = st.st_size;
9bc879c1 684 } else if (p->pack_size != st.st_size)
072db278 685 return error("packfile %s size changed", p->pack_name);
9bc879c1 686
2c039da8
JH
687 /* We leave these file descriptors open with sliding mmap;
688 * there is no point keeping them open across exec(), though.
689 */
690 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
691 if (fd_flag < 0)
072db278 692 return error("cannot determine file descriptor flags");
2c039da8
JH
693 fd_flag |= FD_CLOEXEC;
694 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 695 return error("cannot set FD_CLOEXEC");
2c039da8 696
9bc879c1 697 /* Verify we recognize this pack file format. */
e6e2bd62 698 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 699 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 700 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 701 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 702 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
703 return error("packfile %s is version %"PRIu32" and not"
704 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
705 p->pack_name, ntohl(hdr.hdr_version));
706
707 /* Verify the pack matches its index. */
57059091 708 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
709 return error("packfile %s claims to have %"PRIu32" objects"
710 " while index indicates %"PRIu32" objects",
57059091
NP
711 p->pack_name, ntohl(hdr.hdr_entries),
712 p->num_objects);
9bc879c1 713 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 714 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 715 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 716 return error("packfile %s signature is unavailable", p->pack_name);
42873078 717 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 718 if (hashcmp(sha1, idx_sha1))
072db278
SP
719 return error("packfile %s does not match index", p->pack_name);
720 return 0;
9bc879c1
SP
721}
722
3cf8b462
SP
723static int open_packed_git(struct packed_git *p)
724{
725 if (!open_packed_git_1(p))
726 return 0;
727 if (p->pack_fd != -1) {
728 close(p->pack_fd);
729 p->pack_fd = -1;
730 }
731 return -1;
732}
733
c4001d92 734static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
735{
736 /* We must promise at least 20 bytes (one hash) after the
737 * offset is available from this window, otherwise the offset
738 * is not actually in this window and a different window (which
739 * has that one hash excess) must be used. This is to support
740 * the object header and delta base parsing routines below.
741 */
742 off_t win_off = win->offset;
743 return win_off <= offset
744 && (offset + 20) <= (win_off + win->len);
745}
746
4b25d091 747unsigned char *use_pack(struct packed_git *p,
03e79c88 748 struct pack_window **w_cursor,
c4001d92 749 off_t offset,
03e79c88 750 unsigned int *left)
9bc879c1 751{
60bb8b14 752 struct pack_window *win = *w_cursor;
03e79c88 753
072db278
SP
754 if (p->pack_fd == -1 && open_packed_git(p))
755 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14 756
a9d98a14 757 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
758 * pointless to ask for an offset into the middle of that
759 * hash, and the in_window function above wouldn't match
760 * don't allow an offset too close to the end of the file.
761 */
762 if (offset > (p->pack_size - 20))
763 die("offset beyond end of packfile (truncated pack?)");
764
765 if (!win || !in_window(win, offset)) {
766 if (win)
767 win->inuse_cnt--;
768 for (win = p->windows; win; win = win->next) {
769 if (in_window(win, offset))
770 break;
771 }
772 if (!win) {
78a28df9 773 size_t window_align = packed_git_window_size / 2;
dc49cd76 774 off_t len;
60bb8b14 775 win = xcalloc(1, sizeof(*win));
78a28df9 776 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
777 len = p->pack_size - win->offset;
778 if (len > packed_git_window_size)
779 len = packed_git_window_size;
780 win->len = (size_t)len;
60bb8b14 781 pack_mapped += win->len;
11daf39b 782 while (packed_git_limit < pack_mapped
d1efefa4 783 && unuse_one_window(p, p->pack_fd))
60bb8b14 784 ; /* nothing */
c4712e45 785 win->base = xmmap(NULL, win->len,
60bb8b14
SP
786 PROT_READ, MAP_PRIVATE,
787 p->pack_fd, win->offset);
788 if (win->base == MAP_FAILED)
73b4e4be
SP
789 die("packfile %s cannot be mapped: %s",
790 p->pack_name,
791 strerror(errno));
a53128b6
SP
792 pack_mmap_calls++;
793 pack_open_windows++;
794 if (pack_mapped > peak_pack_mapped)
795 peak_pack_mapped = pack_mapped;
796 if (pack_open_windows > peak_pack_open_windows)
797 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
798 win->next = p->windows;
799 p->windows = win;
800 }
1f688557 801 }
03e79c88
SP
802 if (win != *w_cursor) {
803 win->last_used = pack_used_ctr++;
804 win->inuse_cnt++;
805 *w_cursor = win;
806 }
60bb8b14 807 offset -= win->offset;
03e79c88 808 if (left)
dc49cd76 809 *left = win->len - xsize_t(offset);
03e79c88 810 return win->base + offset;
1f688557
JH
811}
812
27d69a46
NP
813static struct packed_git *alloc_packed_git(int extra)
814{
815 struct packed_git *p = xmalloc(sizeof(*p) + extra);
816 memset(p, 0, sizeof(*p));
817 p->pack_fd = -1;
818 return p;
819}
820
e0500293
JN
821static void try_to_free_pack_memory(size_t size)
822{
823 release_pack_memory(size, -1);
824}
825
42873078 826struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557 827{
e0500293 828 static int have_set_try_to_free_routine;
1f688557 829 struct stat st;
27d69a46 830 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 831
e0500293
JN
832 if (!have_set_try_to_free_routine) {
833 have_set_try_to_free_routine = 1;
834 set_try_to_free_routine(try_to_free_pack_memory);
835 }
836
42873078
NP
837 /*
838 * Make sure a corresponding .pack file exists and that
839 * the index looks sane.
840 */
841 path_len -= strlen(".idx");
27d69a46
NP
842 if (path_len < 1) {
843 free(p);
1f688557 844 return NULL;
27d69a46 845 }
42873078 846 memcpy(p->pack_name, path, path_len);
8d25931d
BC
847
848 strcpy(p->pack_name + path_len, ".keep");
849 if (!access(p->pack_name, F_OK))
850 p->pack_keep = 1;
851
42873078 852 strcpy(p->pack_name + path_len, ".pack");
d079837e 853 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 854 free(p);
1f688557
JH
855 return NULL;
856 }
42873078 857
1f688557
JH
858 /* ok, it looks sane as far as we can check without
859 * actually mapping the pack file.
860 */
1f688557 861 p->pack_size = st.st_size;
9d835df2 862 p->pack_local = local;
b867092f 863 p->mtime = st.st_mtime;
42873078
NP
864 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
865 hashclr(p->sha1);
1f688557
JH
866 return p;
867}
868
7b64469a 869struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 870{
42873078 871 const char *path = sha1_pack_name(sha1);
27d69a46 872 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 873
27d69a46
NP
874 strcpy(p->pack_name, path);
875 hashcpy(p->sha1, sha1);
42873078
NP
876 if (check_packed_git_idx(idx_path, p)) {
877 free(p);
bf592c50 878 return NULL;
42873078 879 }
bf592c50 880
bf592c50
DB
881 return p;
882}
883
884void install_packed_git(struct packed_git *pack)
885{
886 pack->next = packed_git;
887 packed_git = pack;
888}
889
9d835df2 890static void prepare_packed_git_one(char *objdir, int local)
1f688557 891{
9cb18f56
JM
892 /* Ensure that this buffer is large enough so that we can
893 append "/pack/" without clobbering the stack even if
894 strlen(objdir) were PATH_MAX. */
895 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
896 int len;
897 DIR *dir;
898 struct dirent *de;
899
900 sprintf(path, "%s/pack", objdir);
901 len = strlen(path);
902 dir = opendir(path);
f2e872aa 903 while (!dir && errno == EMFILE && unuse_one_window(NULL, -1))
fd73ccf2 904 dir = opendir(path);
b5b16990 905 if (!dir) {
26125f6b 906 if (errno != ENOENT)
bd2afde8 907 error("unable to open object pack directory: %s: %s",
26125f6b 908 path, strerror(errno));
1f688557 909 return;
b5b16990 910 }
1f688557
JH
911 path[len++] = '/';
912 while ((de = readdir(dir)) != NULL) {
913 int namelen = strlen(de->d_name);
914 struct packed_git *p;
915
5bb1cda5 916 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
917 continue;
918
9cb18f56
JM
919 if (len + namelen + 1 > sizeof(path))
920 continue;
921
54a15a8d 922 /* Don't reopen a pack we already have. */
1f688557 923 strcpy(path + len, de->d_name);
86f7780c
JK
924 for (p = packed_git; p; p = p->next) {
925 if (!memcmp(path, p->pack_name, len + namelen - 4))
926 break;
927 }
928 if (p)
929 continue;
54a15a8d
SP
930 /* See if it really is a valid .idx file with corresponding
931 * .pack file that we can map.
932 */
9d835df2 933 p = add_packed_git(path, len + namelen, local);
1f688557
JH
934 if (!p)
935 continue;
625e9421 936 install_packed_git(p);
1f688557 937 }
5b35bcd5 938 closedir(dir);
1f688557
JH
939}
940
b867092f
JH
941static int sort_pack(const void *a_, const void *b_)
942{
943 struct packed_git *a = *((struct packed_git **)a_);
944 struct packed_git *b = *((struct packed_git **)b_);
945 int st;
946
947 /*
948 * Local packs tend to contain objects specific to our
949 * variant of the project than remote ones. In addition,
950 * remote ones could be on a network mounted filesystem.
951 * Favor local ones for these reasons.
952 */
953 st = a->pack_local - b->pack_local;
954 if (st)
955 return -st;
956
957 /*
958 * Younger packs tend to contain more recent objects,
959 * and more recent objects tend to get accessed more
960 * often.
961 */
962 if (a->mtime < b->mtime)
963 return 1;
964 else if (a->mtime == b->mtime)
965 return 0;
966 return -1;
967}
968
969static void rearrange_packed_git(void)
970{
971 struct packed_git **ary, *p;
972 int i, n;
973
974 for (n = 0, p = packed_git; p; p = p->next)
975 n++;
976 if (n < 2)
977 return;
978
979 /* prepare an array of packed_git for easier sorting */
980 ary = xcalloc(n, sizeof(struct packed_git *));
981 for (n = 0, p = packed_git; p; p = p->next)
982 ary[n++] = p;
983
984 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
985
986 /* link them back again */
987 for (i = 0; i < n - 1; i++)
988 ary[i]->next = ary[i + 1];
989 ary[n - 1]->next = NULL;
990 packed_git = ary[0];
991
992 free(ary);
993}
994
637cdd9d 995static int prepare_packed_git_run_once = 0;
9a217f2a 996void prepare_packed_git(void)
1f688557 997{
d5a63b99 998 struct alternate_object_database *alt;
1f688557 999
637cdd9d 1000 if (prepare_packed_git_run_once)
1f688557 1001 return;
9d835df2 1002 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1003 prepare_alt_odb();
d5a63b99 1004 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 1005 alt->name[-1] = 0;
9d835df2 1006 prepare_packed_git_one(alt->base, 0);
1494e038 1007 alt->name[-1] = '/';
1f688557 1008 }
b867092f 1009 rearrange_packed_git();
637cdd9d
JK
1010 prepare_packed_git_run_once = 1;
1011}
1012
fc04c412 1013void reprepare_packed_git(void)
637cdd9d 1014{
4b480c67 1015 discard_revindex();
637cdd9d
JK
1016 prepare_packed_git_run_once = 0;
1017 prepare_packed_git();
1f688557
JH
1018}
1019
8eca0b47
NP
1020static void mark_bad_packed_object(struct packed_git *p,
1021 const unsigned char *sha1)
1022{
1023 unsigned i;
1024 for (i = 0; i < p->num_bad_objects; i++)
1025 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1026 return;
1027 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1028 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1029 p->num_bad_objects++;
1030}
1031
b6c4cecc 1032static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1033{
1034 struct packed_git *p;
1035 unsigned i;
1036
1037 for (p = packed_git; p; p = p->next)
1038 for (i = 0; i < p->num_bad_objects; i++)
1039 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1040 return p;
1041 return NULL;
ac939109
NP
1042}
1043
5d6ccf5c 1044int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
1045{
1046 unsigned char real_sha1[20];
7cfb5f36 1047 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 1048 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1049}
1050
f2e872aa 1051static int git_open_noatime(const char *name, struct packed_git *p)
44d1c19e
LT
1052{
1053 static int sha1_file_open_flag = O_NOATIME;
44d1c19e 1054
f2e872aa
SP
1055 for (;;) {
1056 int fd = open(name, O_RDONLY | sha1_file_open_flag);
44d1c19e 1057 if (fd >= 0)
f2e872aa
SP
1058 return fd;
1059
1060 /* Might the failure be insufficient file descriptors? */
1061 if (errno == EMFILE) {
1062 if (unuse_one_window(p, -1))
1063 continue;
1064 else
1065 return -1;
1066 }
1067
1068 /* Might the failure be due to O_NOATIME? */
1069 if (errno != ENOENT && sha1_file_open_flag) {
44d1c19e 1070 sha1_file_open_flag = 0;
f2e872aa
SP
1071 continue;
1072 }
1073
1074 return -1;
44d1c19e 1075 }
44d1c19e
LT
1076}
1077
1078static int open_sha1_file(const unsigned char *sha1)
1079{
1080 int fd;
1081 char *name = sha1_file_name(sha1);
1082 struct alternate_object_database *alt;
1083
f2e872aa 1084 fd = git_open_noatime(name, NULL);
44d1c19e
LT
1085 if (fd >= 0)
1086 return fd;
1087
1088 prepare_alt_odb();
1089 errno = ENOENT;
1090 for (alt = alt_odb_list; alt; alt = alt->next) {
1091 name = alt->name;
1092 fill_sha1_path(name, sha1);
f2e872aa 1093 fd = git_open_noatime(alt->base, NULL);
44d1c19e
LT
1094 if (fd >= 0)
1095 return fd;
1096 }
1097 return -1;
1098}
1099
4175e9e3 1100static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1101{
0fcfd160 1102 void *map;
144bde78 1103 int fd;
ace1534d 1104
44d1c19e
LT
1105 fd = open_sha1_file(sha1);
1106 map = NULL;
1107 if (fd >= 0) {
1108 struct stat st;
0fcfd160 1109
44d1c19e
LT
1110 if (!fstat(fd, &st)) {
1111 *size = xsize_t(st.st_size);
1112 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1113 }
44d1c19e 1114 close(fd);
0fcfd160 1115 }
0fcfd160
LT
1116 return map;
1117}
1118
726f852b 1119static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1120{
1121 unsigned int word;
1122
1123 /*
1124 * Is it a zlib-compressed buffer? If so, the first byte
1125 * must be 0x78 (15-bit window size, deflated), and the
1126 * first 16-bit word is evenly divisible by 31
1127 */
1128 word = (map[0] << 8) + map[1];
1129 if (map[0] == 0x78 && !(word % 31))
1130 return 1;
1131 else
1132 return 0;
1133}
1134
09ded04b
NP
1135unsigned long unpack_object_header_buffer(const unsigned char *buf,
1136 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1137{
ad1ed5ee 1138 unsigned shift;
48fb7deb 1139 unsigned long size, c;
ad1ed5ee
JH
1140 unsigned long used = 0;
1141
1142 c = buf[used++];
1143 *type = (c >> 4) & 7;
1144 size = c & 15;
1145 shift = 4;
1146 while (c & 0x80) {
f630cfda 1147 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1148 error("bad object header");
ad1ed5ee 1149 return 0;
09ded04b 1150 }
ad1ed5ee
JH
1151 c = buf[used++];
1152 size += (c & 0x7f) << shift;
1153 shift += 7;
1154 }
1155 *sizep = size;
1156 return used;
1157}
1158
1159static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1160{
1161 unsigned long size, used;
1162 static const char valid_loose_object_type[8] = {
1163 0, /* OBJ_EXT */
1164 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1165 0, /* "delta" and others are invalid in a loose object */
93821bd9 1166 };
ad1ed5ee 1167 enum object_type type;
93821bd9 1168
c4483576
LT
1169 /* Get the data stream */
1170 memset(stream, 0, sizeof(*stream));
1171 stream->next_in = map;
1172 stream->avail_in = mapsize;
1173 stream->next_out = buffer;
93821bd9
LT
1174 stream->avail_out = bufsiz;
1175
bb6b8e4f 1176 if (legacy_loose_object(map)) {
39c68542
LT
1177 git_inflate_init(stream);
1178 return git_inflate(stream, 0);
93821bd9
LT
1179 }
1180
726f852b
NP
1181
1182 /*
1183 * There used to be a second loose object header format which
1184 * was meant to mimic the in-pack format, allowing for direct
1185 * copy of the object data. This format turned up not to be
1186 * really worth it and we don't write it any longer. But we
1187 * can still read it.
1188 */
09ded04b 1189 used = unpack_object_header_buffer(map, mapsize, &type, &size);
ad1ed5ee 1190 if (!used || !valid_loose_object_type[type])
93821bd9 1191 return -1;
ad1ed5ee
JH
1192 map += used;
1193 mapsize -= used;
93821bd9
LT
1194
1195 /* Set up the stream for the rest.. */
1196 stream->next_in = map;
1197 stream->avail_in = mapsize;
39c68542 1198 git_inflate_init(stream);
93821bd9
LT
1199
1200 /* And generate the fake traditional header */
ad1ed5ee 1201 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1202 typename(type), size);
93821bd9 1203 return 0;
c4483576
LT
1204}
1205
7efbff75 1206static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1207{
1208 int bytes = strlen(buffer) + 1;
3aee68aa 1209 unsigned char *buf = xmallocz(size);
93821bd9 1210 unsigned long n;
7efbff75 1211 int status = Z_OK;
5180cacc 1212
93821bd9
LT
1213 n = stream->total_out - bytes;
1214 if (n > size)
1215 n = size;
1216 memcpy(buf, (char *) buffer + bytes, n);
1217 bytes = n;
456cdf6e
LT
1218 if (bytes <= size) {
1219 /*
1220 * The above condition must be (bytes <= size), not
1221 * (bytes < size). In other words, even though we
1222 * expect no more output and set avail_out to zer0,
1223 * the input zlib stream may have bytes that express
1224 * "this concludes the stream", and we *do* want to
1225 * eat that input.
1226 *
1227 * Otherwise we would not be able to test that we
1228 * consumed all the input to reach the expected size;
1229 * we also want to check that zlib tells us that all
1230 * went well with status == Z_STREAM_END at the end.
1231 */
5180cacc
LT
1232 stream->next_out = buf + bytes;
1233 stream->avail_out = size - bytes;
7efbff75 1234 while (status == Z_OK)
39c68542 1235 status = git_inflate(stream, Z_FINISH);
5180cacc 1236 }
456cdf6e 1237 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1238 git_inflate_end(stream);
7efbff75
JH
1239 return buf;
1240 }
1241
1242 if (status < 0)
1243 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1244 else if (stream->avail_in)
1245 error("garbage at end of loose object '%s'",
1246 sha1_to_hex(sha1));
1247 free(buf);
1248 return NULL;
5180cacc
LT
1249}
1250
1251/*
1252 * We used to just use "sscanf()", but that's actually way
1253 * too permissive for what we want to check. So do an anal
1254 * object header parse by hand.
1255 */
21666f1a 1256static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1257{
21666f1a 1258 char type[10];
5180cacc
LT
1259 int i;
1260 unsigned long size;
1261
1262 /*
a6080a0a 1263 * The type can be at most ten bytes (including the
5180cacc 1264 * terminating '\0' that we add), and is followed by
21666f1a 1265 * a space.
5180cacc 1266 */
21666f1a 1267 i = 0;
5180cacc
LT
1268 for (;;) {
1269 char c = *hdr++;
1270 if (c == ' ')
1271 break;
21666f1a
NP
1272 type[i++] = c;
1273 if (i >= sizeof(type))
5180cacc 1274 return -1;
5180cacc 1275 }
21666f1a 1276 type[i] = 0;
5180cacc
LT
1277
1278 /*
1279 * The length must follow immediately, and be in canonical
1280 * decimal format (ie "010" is not valid).
1281 */
1282 size = *hdr++ - '0';
1283 if (size > 9)
1284 return -1;
1285 if (size) {
1286 for (;;) {
1287 unsigned long c = *hdr - '0';
1288 if (c > 9)
1289 break;
1290 hdr++;
1291 size = size * 10 + c;
1292 }
1293 }
1294 *sizep = size;
1295
1296 /*
1297 * The length must be followed by a zero byte
1298 */
21666f1a 1299 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1300}
1301
7efbff75 1302static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1303{
5180cacc 1304 int ret;
0fcfd160 1305 z_stream stream;
5180cacc 1306 char hdr[8192];
0fcfd160 1307
5180cacc 1308 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1309 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1310 return NULL;
1311
7efbff75 1312 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1313}
1314
54dab52a
NP
1315unsigned long get_size_from_delta(struct packed_git *p,
1316 struct pack_window **w_curs,
1317 off_t curpos)
1318{
1319 const unsigned char *data;
1320 unsigned char delta_head[20], *in;
1321 z_stream stream;
1322 int st;
1323
1324 memset(&stream, 0, sizeof(stream));
1325 stream.next_out = delta_head;
1326 stream.avail_out = sizeof(delta_head);
1327
39c68542 1328 git_inflate_init(&stream);
54dab52a
NP
1329 do {
1330 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1331 stream.next_in = in;
39c68542 1332 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1333 curpos += stream.next_in - in;
1334 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1335 stream.total_out < sizeof(delta_head));
39c68542 1336 git_inflate_end(&stream);
3d77d877
NP
1337 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1338 error("delta data unpack-initial failed");
1339 return 0;
1340 }
54dab52a
NP
1341
1342 /* Examine the initial part of the delta to figure out
1343 * the result size.
1344 */
1345 data = delta_head;
1346
1347 /* ignore base size */
1348 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1349
1350 /* Read the result size */
1351 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1352}
1353
c4001d92 1354static off_t get_delta_base(struct packed_git *p,
03e79c88 1355 struct pack_window **w_curs,
c4001d92 1356 off_t *curpos,
21666f1a 1357 enum object_type type,
c4001d92 1358 off_t delta_obj_offset)
eb32d236 1359{
2b87c45b 1360 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1361 off_t base_offset;
eb32d236 1362
8d8a4ea5
SP
1363 /* use_pack() assured us we have [base_info, base_info + 20)
1364 * as a range that we can look at without walking off the
1365 * end of the mapped window. Its actually the hash size
1366 * that is assured. An OFS_DELTA longer than the hash size
1367 * is stupid, as then a REF_DELTA would be smaller to store.
1368 */
21666f1a 1369 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1370 unsigned used = 0;
1371 unsigned char c = base_info[used++];
1372 base_offset = c & 127;
1373 while (c & 128) {
1374 base_offset += 1;
8723f216 1375 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1376 return 0; /* overflow */
eb32d236
NP
1377 c = base_info[used++];
1378 base_offset = (base_offset << 7) + (c & 127);
1379 }
1380 base_offset = delta_obj_offset - base_offset;
d8f32556 1381 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 1382 return 0; /* out of bound */
2b87c45b 1383 *curpos += used;
21666f1a 1384 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1385 /* The base entry _must_ be in the same pack */
1386 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1387 *curpos += 20;
eb32d236
NP
1388 } else
1389 die("I am totally screwed");
2b87c45b 1390 return base_offset;
eb32d236
NP
1391}
1392
f3bf9224 1393/* forward declaration for a mutually recursive function */
c4001d92 1394static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1395 unsigned long *sizep);
f3bf9224 1396
43057304 1397static int packed_delta_info(struct packed_git *p,
03e79c88 1398 struct pack_window **w_curs,
c4001d92 1399 off_t curpos,
21666f1a 1400 enum object_type type,
c4001d92 1401 off_t obj_offset,
43057304 1402 unsigned long *sizep)
5db47c2b 1403{
c4001d92 1404 off_t base_offset;
f3bf9224 1405
21666f1a 1406 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
3d77d877
NP
1407 if (!base_offset)
1408 return OBJ_BAD;
21666f1a 1409 type = packed_object_info(p, base_offset, NULL);
3d77d877 1410 if (type <= OBJ_NONE) {
08698b1e
NP
1411 struct revindex_entry *revidx;
1412 const unsigned char *base_sha1;
1413 revidx = find_pack_revindex(p, base_offset);
1414 if (!revidx)
1415 return OBJ_BAD;
1416 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
3d77d877
NP
1417 mark_bad_packed_object(p, base_sha1);
1418 type = sha1_object_info(base_sha1, NULL);
1419 if (type <= OBJ_NONE)
1420 return OBJ_BAD;
1421 }
f3bf9224 1422
c62266f3
JH
1423 /* We choose to only get the type of the base object and
1424 * ignore potentially corrupt pack file that expects the delta
1425 * based on a base with a wrong size. This saves tons of
1426 * inflate() calls.
1427 */
3d77d877 1428 if (sizep) {
54dab52a 1429 *sizep = get_size_from_delta(p, w_curs, curpos);
3d77d877
NP
1430 if (*sizep == 0)
1431 type = OBJ_BAD;
1432 }
21666f1a
NP
1433
1434 return type;
5db47c2b
JH
1435}
1436
2b87c45b
NP
1437static int unpack_object_header(struct packed_git *p,
1438 struct pack_window **w_curs,
c4001d92 1439 off_t *curpos,
2b87c45b 1440 unsigned long *sizep)
a733cb60 1441{
03e79c88
SP
1442 unsigned char *base;
1443 unsigned int left;
ad1ed5ee 1444 unsigned long used;
2b87c45b 1445 enum object_type type;
a733cb60 1446
8d8a4ea5
SP
1447 /* use_pack() assures us we have [base, base + 20) available
1448 * as a range that we can look at at. (Its actually the hash
3dff5379 1449 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1450 * the maximum deflated object size is 2^137, which is just
1451 * insane, so we know won't exceed what we have been given.
1452 */
2b87c45b 1453 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
1454 used = unpack_object_header_buffer(base, left, &type, sizep);
1455 if (!used) {
1456 type = OBJ_BAD;
1457 } else
1458 *curpos += used;
ad1ed5ee 1459
2b87c45b 1460 return type;
a733cb60
LT
1461}
1462
21666f1a 1463const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1464 off_t obj_offset,
21666f1a
NP
1465 unsigned long *size,
1466 unsigned long *store_size,
1467 unsigned int *delta_chain_length,
1468 unsigned char *base_sha1)
ad8c80a5 1469{
03e79c88 1470 struct pack_window *w_curs = NULL;
c4001d92
SP
1471 off_t curpos;
1472 unsigned long dummy;
43057304 1473 unsigned char *next_sha1;
21666f1a 1474 enum object_type type;
70f5d5d3 1475 struct revindex_entry *revidx;
ad8c80a5 1476
43057304 1477 *delta_chain_length = 0;
2b87c45b 1478 curpos = obj_offset;
21666f1a 1479 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304 1480
70f5d5d3
NP
1481 revidx = find_pack_revindex(p, obj_offset);
1482 *store_size = revidx[1].offset - obj_offset;
1483
43057304 1484 for (;;) {
21666f1a 1485 switch (type) {
43057304 1486 default:
08a19d87 1487 die("pack %s contains unknown object type %d",
21666f1a 1488 p->pack_name, type);
43057304
NP
1489 case OBJ_COMMIT:
1490 case OBJ_TREE:
1491 case OBJ_BLOB:
1492 case OBJ_TAG:
03e79c88 1493 unuse_pack(&w_curs);
21666f1a 1494 return typename(type);
eb32d236 1495 case OBJ_OFS_DELTA:
21666f1a 1496 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
8eca0b47
NP
1497 if (!obj_offset)
1498 die("pack %s contains bad delta base reference of type %s",
1499 p->pack_name, typename(type));
eb32d236 1500 if (*delta_chain_length == 0) {
70f5d5d3
NP
1501 revidx = find_pack_revindex(p, obj_offset);
1502 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
eb32d236
NP
1503 }
1504 break;
1505 case OBJ_REF_DELTA:
2b87c45b 1506 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1507 if (*delta_chain_length == 0)
1508 hashcpy(base_sha1, next_sha1);
2b87c45b 1509 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1510 break;
1511 }
43057304 1512 (*delta_chain_length)++;
2b87c45b 1513 curpos = obj_offset;
21666f1a 1514 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1515 }
ad8c80a5
JH
1516}
1517
c4001d92 1518static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1519 unsigned long *sizep)
1f688557 1520{
03e79c88 1521 struct pack_window *w_curs = NULL;
c4001d92
SP
1522 unsigned long size;
1523 off_t curpos = obj_offset;
21666f1a 1524 enum object_type type;
5db47c2b 1525
21666f1a 1526 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1527
21666f1a 1528 switch (type) {
eb32d236
NP
1529 case OBJ_OFS_DELTA:
1530 case OBJ_REF_DELTA:
21666f1a
NP
1531 type = packed_delta_info(p, &w_curs, curpos,
1532 type, obj_offset, sizep);
2b87c45b 1533 break;
a733cb60 1534 case OBJ_COMMIT:
a733cb60 1535 case OBJ_TREE:
a733cb60 1536 case OBJ_BLOB:
a733cb60 1537 case OBJ_TAG:
2b87c45b
NP
1538 if (sizep)
1539 *sizep = size;
a69d0943 1540 break;
1f688557 1541 default:
3d77d877
NP
1542 error("unknown object type %i at offset %"PRIuMAX" in %s",
1543 type, (uintmax_t)obj_offset, p->pack_name);
1544 type = OBJ_BAD;
1f688557 1545 }
2b87c45b 1546 unuse_pack(&w_curs);
21666f1a 1547 return type;
1f688557
JH
1548}
1549
eb950c19 1550static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1551 struct pack_window **w_curs,
c4001d92 1552 off_t curpos,
eb950c19 1553 unsigned long size)
de530aaa
SP
1554{
1555 int st;
1556 z_stream stream;
079afb18 1557 unsigned char *buffer, *in;
de530aaa 1558
4ab07e4d 1559 buffer = xmallocz(size);
de530aaa 1560 memset(&stream, 0, sizeof(stream));
de530aaa 1561 stream.next_out = buffer;
39eea7bd 1562 stream.avail_out = size + 1;
de530aaa 1563
39c68542 1564 git_inflate_init(&stream);
079afb18 1565 do {
2b87c45b 1566 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 1567 stream.next_in = in;
39c68542 1568 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
1569 if (!stream.avail_out)
1570 break; /* the payload is larger than it should be */
2b87c45b 1571 curpos += stream.next_in - in;
079afb18 1572 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 1573 git_inflate_end(&stream);
de530aaa
SP
1574 if ((st != Z_STREAM_END) || stream.total_out != size) {
1575 free(buffer);
1576 return NULL;
1577 }
1578
1579 return buffer;
1580}
1581
e5e01619
LT
1582#define MAX_DELTA_CACHE (256)
1583
18bdec11 1584static size_t delta_base_cached;
5e08ecbf
NP
1585
1586static struct delta_base_cache_lru_list {
1587 struct delta_base_cache_lru_list *prev;
1588 struct delta_base_cache_lru_list *next;
1589} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1590
e5e01619 1591static struct delta_base_cache_entry {
5e08ecbf
NP
1592 struct delta_base_cache_lru_list lru;
1593 void *data;
e5e01619
LT
1594 struct packed_git *p;
1595 off_t base_offset;
1596 unsigned long size;
e5e01619
LT
1597 enum object_type type;
1598} delta_base_cache[MAX_DELTA_CACHE];
1599
1600static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1601{
1602 unsigned long hash;
1603
1604 hash = (unsigned long)p + (unsigned long)base_offset;
1605 hash += (hash >> 8) + (hash >> 16);
3358004a 1606 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1607}
1608
62f255ad 1609static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1610 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1611{
e5e01619
LT
1612 void *ret;
1613 unsigned long hash = pack_entry_hash(p, base_offset);
1614 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1615
1616 ret = ent->data;
749bc58c
MV
1617 if (!ret || ent->p != p || ent->base_offset != base_offset)
1618 return unpack_entry(p, base_offset, type, base_size);
e5e01619 1619
18bdec11 1620 if (!keep_cache) {
a0cba108 1621 ent->data = NULL;
5e08ecbf
NP
1622 ent->lru.next->prev = ent->lru.prev;
1623 ent->lru.prev->next = ent->lru.next;
18bdec11 1624 delta_base_cached -= ent->size;
182af834
PH
1625 } else {
1626 ret = xmemdupz(ent->data, ent->size);
a0cba108 1627 }
e5e01619
LT
1628 *type = ent->type;
1629 *base_size = ent->size;
1630 return ret;
62f255ad
LT
1631}
1632
18bdec11
SP
1633static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1634{
1635 if (ent->data) {
1636 free(ent->data);
1637 ent->data = NULL;
5e08ecbf
NP
1638 ent->lru.next->prev = ent->lru.prev;
1639 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1640 delta_base_cached -= ent->size;
1641 }
1642}
1643
3d20c636
SP
1644void clear_delta_base_cache(void)
1645{
1646 unsigned long p;
1647 for (p = 0; p < MAX_DELTA_CACHE; p++)
1648 release_delta_base_cache(&delta_base_cache[p]);
1649}
1650
62f255ad
LT
1651static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1652 void *base, unsigned long base_size, enum object_type type)
1653{
5e08ecbf 1654 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1655 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1656 struct delta_base_cache_lru_list *lru;
e5e01619 1657
18bdec11
SP
1658 release_delta_base_cache(ent);
1659 delta_base_cached += base_size;
5e08ecbf
NP
1660
1661 for (lru = delta_base_cache_lru.next;
1662 delta_base_cached > delta_base_cache_limit
1663 && lru != &delta_base_cache_lru;
1664 lru = lru->next) {
1665 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1666 if (f->type == OBJ_BLOB)
1667 release_delta_base_cache(f);
1668 }
5e08ecbf
NP
1669 for (lru = delta_base_cache_lru.next;
1670 delta_base_cached > delta_base_cache_limit
1671 && lru != &delta_base_cache_lru;
1672 lru = lru->next) {
1673 struct delta_base_cache_entry *f = (void *)lru;
1674 release_delta_base_cache(f);
1675 }
18bdec11 1676
e5e01619
LT
1677 ent->p = p;
1678 ent->base_offset = base_offset;
1679 ent->type = type;
1680 ent->data = base;
1681 ent->size = base_size;
5e08ecbf
NP
1682 ent->lru.next = &delta_base_cache_lru;
1683 ent->lru.prev = delta_base_cache_lru.prev;
1684 delta_base_cache_lru.prev->next = &ent->lru;
1685 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1686}
1687
c2c5b270
CC
1688static void *read_object(const unsigned char *sha1, enum object_type *type,
1689 unsigned long *size);
1690
eb950c19 1691static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1692 struct pack_window **w_curs,
c4001d92 1693 off_t curpos,
1f688557 1694 unsigned long delta_size,
c4001d92 1695 off_t obj_offset,
21666f1a 1696 enum object_type *type,
eb950c19 1697 unsigned long *sizep)
1f688557 1698{
7c3e8be3 1699 void *delta_data, *result, *base;
c4001d92
SP
1700 unsigned long base_size;
1701 off_t base_offset;
43057304 1702
21666f1a 1703 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
8eca0b47
NP
1704 if (!base_offset) {
1705 error("failed to validate delta base reference "
1706 "at offset %"PRIuMAX" from %s",
1707 (uintmax_t)curpos, p->pack_name);
1708 return NULL;
1709 }
eac12e2d 1710 unuse_pack(w_curs);
a0cba108 1711 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
8eca0b47
NP
1712 if (!base) {
1713 /*
1714 * We're probably in deep shit, but let's try to fetch
1715 * the required base anyway from another pack or loose.
1716 * This is costly but should happen only in the presence
1717 * of a corrupted pack, and is better than failing outright.
1718 */
08698b1e
NP
1719 struct revindex_entry *revidx;
1720 const unsigned char *base_sha1;
1721 revidx = find_pack_revindex(p, base_offset);
1722 if (!revidx)
1723 return NULL;
1724 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
8eca0b47
NP
1725 error("failed to read delta base object %s"
1726 " at offset %"PRIuMAX" from %s",
1727 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1728 p->pack_name);
1729 mark_bad_packed_object(p, base_sha1);
ac939109 1730 base = read_object(base_sha1, type, &base_size);
8eca0b47
NP
1731 if (!base)
1732 return NULL;
1733 }
67686d95 1734
2b87c45b 1735 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
8eca0b47
NP
1736 if (!delta_data) {
1737 error("failed to unpack compressed delta "
1738 "at offset %"PRIuMAX" from %s",
1739 (uintmax_t)curpos, p->pack_name);
1740 free(base);
1741 return NULL;
1742 }
1f688557
JH
1743 result = patch_delta(base, base_size,
1744 delta_data, delta_size,
21666f1a 1745 sizep);
1f688557
JH
1746 if (!result)
1747 die("failed to apply delta");
1748 free(delta_data);
62f255ad 1749 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1750 return result;
1751}
1752
0e8189e2
NP
1753int do_check_packed_object_crc;
1754
c4001d92 1755void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1756 enum object_type *type, unsigned long *sizep)
1f688557 1757{
03e79c88 1758 struct pack_window *w_curs = NULL;
c4001d92 1759 off_t curpos = obj_offset;
21666f1a 1760 void *data;
1f688557 1761
0e8189e2
NP
1762 if (do_check_packed_object_crc && p->index_version > 1) {
1763 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1764 unsigned long len = revidx[1].offset - obj_offset;
1765 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1766 const unsigned char *sha1 =
1767 nth_packed_object_sha1(p, revidx->nr);
1768 error("bad packed object CRC for %s",
1769 sha1_to_hex(sha1));
1770 mark_bad_packed_object(p, sha1);
f755bb99 1771 unuse_pack(&w_curs);
0e8189e2
NP
1772 return NULL;
1773 }
1774 }
1775
21666f1a
NP
1776 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1777 switch (*type) {
eb32d236
NP
1778 case OBJ_OFS_DELTA:
1779 case OBJ_REF_DELTA:
21666f1a
NP
1780 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1781 obj_offset, type, sizep);
4d703a1a 1782 break;
a733cb60 1783 case OBJ_COMMIT:
a733cb60 1784 case OBJ_TREE:
a733cb60 1785 case OBJ_BLOB:
a733cb60 1786 case OBJ_TAG:
21666f1a 1787 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1788 break;
1f688557 1789 default:
8eca0b47
NP
1790 data = NULL;
1791 error("unknown object type %i at offset %"PRIuMAX" in %s",
1792 *type, (uintmax_t)obj_offset, p->pack_name);
1f688557 1793 }
03e79c88 1794 unuse_pack(&w_curs);
21666f1a 1795 return data;
1f688557
JH
1796}
1797
d079837e 1798const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1799 uint32_t n)
9a217f2a 1800{
42873078 1801 const unsigned char *index = p->index_data;
d079837e
SP
1802 if (!index) {
1803 if (open_pack_index(p))
1804 return NULL;
1805 index = p->index_data;
1806 }
57059091 1807 if (n >= p->num_objects)
d72308e0 1808 return NULL;
74e34e1f
NP
1809 index += 4 * 256;
1810 if (p->index_version == 1) {
1811 return index + 24 * n + 4;
1812 } else {
1813 index += 8;
1814 return index + 20 * n;
1815 }
1816}
1817
99093238 1818off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
1819{
1820 const unsigned char *index = p->index_data;
1821 index += 4 * 256;
1822 if (p->index_version == 1) {
1823 return ntohl(*((uint32_t *)(index + 24 * n)));
1824 } else {
1825 uint32_t off;
1826 index += 8 + p->num_objects * (20 + 4);
1827 off = ntohl(*((uint32_t *)(index + 4 * n)));
1828 if (!(off & 0x80000000))
1829 return off;
1830 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1831 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1832 ntohl(*((uint32_t *)(index + 4)));
1833 }
9a217f2a
JH
1834}
1835
c4001d92 1836off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1837 struct packed_git *p)
1f688557 1838{
42873078 1839 const uint32_t *level1_ofs = p->index_data;
42873078 1840 const unsigned char *index = p->index_data;
628522ec
JH
1841 unsigned hi, lo, stride;
1842 static int use_lookup = -1;
1843 static int debug_lookup = -1;
1844
1845 if (debug_lookup < 0)
1846 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1847
d079837e
SP
1848 if (!index) {
1849 if (open_pack_index(p))
1850 return 0;
1851 level1_ofs = p->index_data;
1852 index = p->index_data;
1853 }
74e34e1f
NP
1854 if (p->index_version > 1) {
1855 level1_ofs += 2;
1856 index += 8;
1857 }
42873078 1858 index += 4 * 256;
74e34e1f
NP
1859 hi = ntohl(level1_ofs[*sha1]);
1860 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
1861 if (p->index_version > 1) {
1862 stride = 20;
1863 } else {
1864 stride = 24;
1865 index += 4;
1866 }
1867
1868 if (debug_lookup)
6e1c2344 1869 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
1870 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1871
1872 if (use_lookup < 0)
1873 use_lookup = !!getenv("GIT_USE_LOOKUP");
1874 if (use_lookup) {
1875 int pos = sha1_entry_pos(index, stride, 0,
1876 lo, hi, p->num_objects, sha1);
1877 if (pos < 0)
1878 return 0;
1879 return nth_packed_object_offset(p, pos);
1880 }
1f688557
JH
1881
1882 do {
74e34e1f 1883 unsigned mi = (lo + hi) / 2;
628522ec
JH
1884 int cmp = hashcmp(index + mi * stride, sha1);
1885
1886 if (debug_lookup)
1887 printf("lo %u hi %u rg %u mi %u\n",
1888 lo, hi, hi - lo, mi);
43057304 1889 if (!cmp)
74e34e1f 1890 return nth_packed_object_offset(p, mi);
1f688557
JH
1891 if (cmp > 0)
1892 hi = mi;
1893 else
1894 lo = mi+1;
1895 } while (lo < hi);
1896 return 0;
1897}
1898
4d6acb70 1899static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557 1900{
f7c22cc6 1901 static struct packed_git *last_found = (void *)1;
1f688557 1902 struct packed_git *p;
c4001d92 1903 off_t offset;
43057304 1904
1f688557 1905 prepare_packed_git();
f7c22cc6
NP
1906 if (!packed_git)
1907 return 0;
1908 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1909
f7c22cc6 1910 do {
8eca0b47
NP
1911 if (p->num_bad_objects) {
1912 unsigned i;
1913 for (i = 0; i < p->num_bad_objects; i++)
1914 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1915 goto next;
1916 }
1917
43057304
NP
1918 offset = find_pack_entry_one(sha1, p);
1919 if (offset) {
c715f783
SP
1920 /*
1921 * We are about to tell the caller where they can
1922 * locate the requested object. We better make
1923 * sure the packfile is still here and can be
1924 * accessed before supplying that answer, as
1925 * it may have been deleted since the index
1926 * was loaded!
1927 */
1928 if (p->pack_fd == -1 && open_packed_git(p)) {
1929 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1930 goto next;
c715f783 1931 }
43057304
NP
1932 e->offset = offset;
1933 e->p = p;
1934 hashcpy(e->sha1, sha1);
f7c22cc6 1935 last_found = p;
1f688557 1936 return 1;
43057304 1937 }
f7c22cc6
NP
1938
1939 next:
1940 if (p == last_found)
1941 p = packed_git;
1942 else
1943 p = p->next;
1944 if (p == last_found)
1945 p = p->next;
1946 } while (p);
1f688557
JH
1947 return 0;
1948}
1949
a6080a0a 1950struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1951 struct packed_git *packs)
1952{
1953 struct packed_git *p;
bf592c50
DB
1954
1955 for (p = packs; p; p = p->next) {
43057304 1956 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1957 return p;
1958 }
1959 return NULL;
21666f1a 1960
bf592c50
DB
1961}
1962
21666f1a 1963static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1964{
36e4d74a 1965 int status;
65c2e0c3
JH
1966 unsigned long mapsize, size;
1967 void *map;
1968 z_stream stream;
d65a16f6 1969 char hdr[32];
65c2e0c3 1970
bb6b8e4f 1971 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1972 if (!map)
1973 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1974 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1975 status = error("unable to unpack %s header",
1976 sha1_to_hex(sha1));
21666f1a 1977 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1978 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1979 else if (sizep)
1980 *sizep = size;
39c68542 1981 git_inflate_end(&stream);
65c2e0c3
JH
1982 munmap(map, mapsize);
1983 return status;
1984}
1985
21666f1a 1986int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1987{
f0df4ed5 1988 struct pack_entry e;
ddd63e64 1989 int status;
f0df4ed5 1990
cd673c1f 1991 if (!find_pack_entry(sha1, &e)) {
ddd63e64
SG
1992 /* Most likely it's a loose object. */
1993 status = sha1_loose_object_info(sha1, sizep);
1994 if (status >= 0)
1995 return status;
1996
1997 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 1998 reprepare_packed_git();
cd673c1f 1999 if (!find_pack_entry(sha1, &e))
ddd63e64 2000 return status;
f0df4ed5 2001 }
3d77d877
NP
2002
2003 status = packed_object_info(e.p, e.offset, sizep);
2004 if (status < 0) {
2005 mark_bad_packed_object(e.p, sha1);
2006 status = sha1_object_info(sha1, sizep);
2007 }
2008
2009 return status;
f0df4ed5
JS
2010}
2011
21666f1a
NP
2012static void *read_packed_sha1(const unsigned char *sha1,
2013 enum object_type *type, unsigned long *size)
1f688557
JH
2014{
2015 struct pack_entry e;
8eca0b47 2016 void *data;
1f688557 2017
cd673c1f 2018 if (!find_pack_entry(sha1, &e))
1f688557 2019 return NULL;
8eca0b47
NP
2020 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2021 if (!data) {
2022 /*
2023 * We're probably in deep shit, but let's try to fetch
2024 * the required object anyway from another pack or loose.
2025 * This should happen only in the presence of a corrupted
2026 * pack, and is better than failing outright.
2027 */
2028 error("failed to read object %s at offset %"PRIuMAX" from %s",
2029 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2030 mark_bad_packed_object(e.p, sha1);
ac939109 2031 data = read_object(sha1, type, size);
8eca0b47
NP
2032 }
2033 return data;
1f688557
JH
2034}
2035
d66b37bb
JH
2036/*
2037 * This is meant to hold a *small* number of objects that you would
2038 * want read_sha1_file() to be able to return, but yet you do not want
2039 * to write them into the object store (e.g. a browse-only
2040 * application).
2041 */
2042static struct cached_object {
2043 unsigned char sha1[20];
21666f1a 2044 enum object_type type;
d66b37bb
JH
2045 void *buf;
2046 unsigned long size;
2047} *cached_objects;
2048static int cached_object_nr, cached_object_alloc;
2049
346245a1 2050static struct cached_object empty_tree = {
14d9c578 2051 EMPTY_TREE_SHA1_BIN,
346245a1
JK
2052 OBJ_TREE,
2053 "",
2054 0
2055};
2056
d66b37bb
JH
2057static struct cached_object *find_cached_object(const unsigned char *sha1)
2058{
2059 int i;
2060 struct cached_object *co = cached_objects;
2061
2062 for (i = 0; i < cached_object_nr; i++, co++) {
2063 if (!hashcmp(co->sha1, sha1))
2064 return co;
2065 }
346245a1
JK
2066 if (!hashcmp(sha1, empty_tree.sha1))
2067 return &empty_tree;
d66b37bb
JH
2068 return NULL;
2069}
2070
21666f1a
NP
2071int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2072 unsigned char *sha1)
d66b37bb
JH
2073{
2074 struct cached_object *co;
2075
21666f1a 2076 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2077 if (has_sha1_file(sha1) || find_cached_object(sha1))
2078 return 0;
2079 if (cached_object_alloc <= cached_object_nr) {
2080 cached_object_alloc = alloc_nr(cached_object_alloc);
2081 cached_objects = xrealloc(cached_objects,
2082 sizeof(*cached_objects) *
2083 cached_object_alloc);
2084 }
2085 co = &cached_objects[cached_object_nr++];
2086 co->size = len;
21666f1a 2087 co->type = type;
efa13f7b
JH
2088 co->buf = xmalloc(len);
2089 memcpy(co->buf, buf, len);
d66b37bb
JH
2090 hashcpy(co->sha1, sha1);
2091 return 0;
2092}
2093
c2c5b270
CC
2094static void *read_object(const unsigned char *sha1, enum object_type *type,
2095 unsigned long *size)
0fcfd160
LT
2096{
2097 unsigned long mapsize;
2098 void *map, *buf;
d66b37bb
JH
2099 struct cached_object *co;
2100
2101 co = find_cached_object(sha1);
2102 if (co) {
21666f1a 2103 *type = co->type;
d66b37bb 2104 *size = co->size;
182af834 2105 return xmemdupz(co->buf, co->size);
d66b37bb 2106 }
0fcfd160 2107
8276c007
PE
2108 buf = read_packed_sha1(sha1, type, size);
2109 if (buf)
2110 return buf;
bb6b8e4f 2111 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2112 if (map) {
7efbff75 2113 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2114 munmap(map, mapsize);
2115 return buf;
2116 }
637cdd9d 2117 reprepare_packed_git();
8276c007 2118 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2119}
2120
b6c4cecc
JH
2121/*
2122 * This function dies on corrupt objects; the callers who want to
2123 * deal with them should arrange to call read_object() and give error
2124 * messages themselves.
2125 */
f5552aee
CC
2126void *read_sha1_file_repl(const unsigned char *sha1,
2127 enum object_type *type,
2128 unsigned long *size,
2129 const unsigned char **replacement)
ac939109 2130{
68095570 2131 const unsigned char *repl = lookup_replace_object(sha1);
3ba7a065 2132 void *data;
e8b15e61 2133 char *path;
b6c4cecc
JH
2134 const struct packed_git *p;
2135
3ba7a065
JH
2136 errno = 0;
2137 data = read_object(repl, type, size);
b6c4cecc
JH
2138 if (data) {
2139 if (replacement)
2140 *replacement = repl;
2141 return data;
2142 }
68095570 2143
25f3af3f 2144 if (errno && errno != ENOENT)
3ba7a065
JH
2145 die_errno("failed to read object %s", sha1_to_hex(sha1));
2146
68095570 2147 /* die if we replaced an object with one that does not exist */
b6c4cecc 2148 if (repl != sha1)
68095570
CC
2149 die("replacement %s not found for %s",
2150 sha1_to_hex(repl), sha1_to_hex(sha1));
2151
b6c4cecc
JH
2152 if (has_loose_object(repl)) {
2153 path = sha1_file_name(sha1);
2154 die("loose object %s (stored in %s) is corrupt",
2155 sha1_to_hex(repl), path);
e8b15e61 2156 }
68095570 2157
b6c4cecc
JH
2158 if ((p = has_packed_and_bad(repl)) != NULL)
2159 die("packed object %s (stored in %s) is corrupt",
2160 sha1_to_hex(repl), p->pack_name);
f5552aee 2161
b6c4cecc 2162 return NULL;
ac939109
NP
2163}
2164
40469ee9 2165void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2166 const char *required_type_name,
40469ee9
JH
2167 unsigned long *size,
2168 unsigned char *actual_sha1_return)
f4913f91 2169{
21666f1a 2170 enum object_type type, required_type;
f4913f91
JH
2171 void *buffer;
2172 unsigned long isize;
40469ee9 2173 unsigned char actual_sha1[20];
f4913f91 2174
21666f1a 2175 required_type = type_from_string(required_type_name);
e702496e 2176 hashcpy(actual_sha1, sha1);
40469ee9
JH
2177 while (1) {
2178 int ref_length = -1;
2179 const char *ref_type = NULL;
f4913f91 2180
21666f1a 2181 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2182 if (!buffer)
2183 return NULL;
21666f1a 2184 if (type == required_type) {
40469ee9
JH
2185 *size = isize;
2186 if (actual_sha1_return)
e702496e 2187 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2188 return buffer;
2189 }
2190 /* Handle references */
21666f1a 2191 else if (type == OBJ_COMMIT)
40469ee9 2192 ref_type = "tree ";
21666f1a 2193 else if (type == OBJ_TAG)
40469ee9
JH
2194 ref_type = "object ";
2195 else {
2196 free(buffer);
2197 return NULL;
2198 }
2199 ref_length = strlen(ref_type);
f4913f91 2200
50974ec9
MK
2201 if (ref_length + 40 > isize ||
2202 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2203 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2204 free(buffer);
2205 return NULL;
2206 }
1cf58e72 2207 free(buffer);
40469ee9
JH
2208 /* Now we have the ID of the referred-to object in
2209 * actual_sha1. Check again. */
f4913f91 2210 }
f4913f91
JH
2211}
2212
ce9fbf16 2213static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2214 const char *type, unsigned char *sha1,
d65a16f6 2215 char *hdr, int *hdrlen)
d410c0f5 2216{
9126f009 2217 git_SHA_CTX c;
d410c0f5
JH
2218
2219 /* Generate the header */
d65a16f6 2220 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2221
2222 /* Sha1.. */
9126f009
NP
2223 git_SHA1_Init(&c);
2224 git_SHA1_Update(&c, hdr, *hdrlen);
2225 git_SHA1_Update(&c, buf, len);
2226 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2227}
2228
230f1322 2229/*
5a688fe4
JH
2230 * Move the just written object into its final resting place.
2231 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2232 * "moving" is only a part of what it does, when no patch between
2233 * master to pu changes the call sites of this function.
230f1322 2234 */
839837b9 2235int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2236{
e32c0a9c 2237 int ret = 0;
5a688fe4 2238
348df166 2239 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
2240 goto try_rename;
2241 else if (link(tmpfile, filename))
e32c0a9c 2242 ret = errno;
7ebb6fca
LT
2243
2244 /*
2245 * Coda hack - coda doesn't like cross-directory links,
2246 * so we fall back to a rename, which will mean that it
2247 * won't be able to check collisions, but that's not a
2248 * big deal.
2249 *
2250 * The same holds for FAT formatted media.
2251 *
3be1f18e 2252 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
2253 * left to unlink.
2254 */
2255 if (ret && ret != EEXIST) {
be66a6c4 2256 try_rename:
7ebb6fca 2257 if (!rename(tmpfile, filename))
3be1f18e 2258 goto out;
9e48b389 2259 ret = errno;
230f1322 2260 }
691f1a28 2261 unlink_or_warn(tmpfile);
230f1322
LT
2262 if (ret) {
2263 if (ret != EEXIST) {
916d081b 2264 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2265 }
2266 /* FIXME!!! Collision check here ? */
2267 }
2268
3be1f18e 2269out:
5256b006 2270 if (adjust_shared_perm(filename))
5a688fe4 2271 return error("unable to set permission to '%s'", filename);
230f1322
LT
2272 return 0;
2273}
2274
4d548150
LT
2275static int write_buffer(int fd, const void *buf, size_t len)
2276{
d34cf19b 2277 if (write_in_full(fd, buf, len) < 0)
93822c22 2278 return error("file write error (%s)", strerror(errno));
4d548150
LT
2279 return 0;
2280}
2281
ce9fbf16 2282int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2283 unsigned char *sha1)
2284{
d65a16f6 2285 char hdr[32];
abdc3fc8
RS
2286 int hdrlen;
2287 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2288 return 0;
2289}
2290
e9039dd3
LT
2291/* Finalize a file on disk, and close it. */
2292static void close_sha1_file(int fd)
2293{
aafe9fba
LT
2294 if (fsync_object_files)
2295 fsync_or_die(fd, "sha1 file");
e9039dd3 2296 if (close(fd) != 0)
d824cbba 2297 die_errno("error when closing sha1 file");
e9039dd3
LT
2298}
2299
5723fe7e
LT
2300/* Size of directory component, including the ending '/' */
2301static inline int directory_size(const char *filename)
2302{
2303 const char *s = strrchr(filename, '/');
2304 if (!s)
2305 return 0;
2306 return s - filename + 1;
2307}
2308
2309/*
2310 * This creates a temporary file in the same directory as the final
2311 * 'filename'
2312 *
2313 * We want to avoid cross-directory filename renames, because those
2314 * can have problems on various filesystems (FAT, NFS, Coda).
2315 */
2316static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2317{
2318 int fd, dirlen = directory_size(filename);
2319
2320 if (dirlen + 20 > bufsiz) {
2321 errno = ENAMETOOLONG;
2322 return -1;
2323 }
2324 memcpy(buffer, filename, dirlen);
2325 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
5256b006 2326 fd = git_mkstemp_mode(buffer, 0444);
cbacbf4e 2327 if (fd < 0 && dirlen && errno == ENOENT) {
5723fe7e 2328 /* Make sure the directory exists */
6ff6af62 2329 memcpy(buffer, filename, dirlen);
5723fe7e 2330 buffer[dirlen-1] = 0;
3bfaf018 2331 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2332 return -1;
2333
2334 /* Try again */
2335 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
5256b006 2336 fd = git_mkstemp_mode(buffer, 0444);
5723fe7e
LT
2337 }
2338 return fd;
2339}
2340
bbac7311 2341static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 2342 const void *buf, unsigned long len, time_t mtime)
0fcfd160 2343{
915308b1 2344 int fd, ret;
9892beba 2345 unsigned char compressed[4096];
0fcfd160 2346 z_stream stream;
748af44c
NP
2347 git_SHA_CTX c;
2348 unsigned char parano_sha1[20];
706bc531 2349 char *filename;
aac17941 2350 static char tmpfile[PATH_MAX];
a44c9a5e 2351
972a9155 2352 filename = sha1_file_name(sha1);
5723fe7e 2353 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
f2e872aa 2354 while (fd < 0 && errno == EMFILE && unuse_one_window(NULL, -1))
fd73ccf2 2355 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
aac17941 2356 if (fd < 0) {
35243577 2357 if (errno == EACCES)
916d081b
PB
2358 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2359 else
2360 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2361 }
2362
0fcfd160
LT
2363 /* Set it up */
2364 memset(&stream, 0, sizeof(stream));
12f6c308 2365 deflateInit(&stream, zlib_compression_level);
0fcfd160 2366 stream.next_out = compressed;
9892beba 2367 stream.avail_out = sizeof(compressed);
748af44c 2368 git_SHA1_Init(&c);
a44c9a5e
LT
2369
2370 /* First header.. */
d65a16f6 2371 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2372 stream.avail_in = hdrlen;
726f852b
NP
2373 while (deflate(&stream, 0) == Z_OK)
2374 /* nothing */;
748af44c 2375 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
2376
2377 /* Then the data itself.. */
c00e657d 2378 stream.next_in = (void *)buf;
a44c9a5e 2379 stream.avail_in = len;
9892beba 2380 do {
748af44c 2381 unsigned char *in0 = stream.next_in;
9892beba 2382 ret = deflate(&stream, Z_FINISH);
748af44c 2383 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
2384 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2385 die("unable to write sha1 file");
2386 stream.next_out = compressed;
2387 stream.avail_out = sizeof(compressed);
2388 } while (ret == Z_OK);
2389
ac54c277
LT
2390 if (ret != Z_STREAM_END)
2391 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
ac54c277
LT
2392 ret = deflateEnd(&stream);
2393 if (ret != Z_OK)
2394 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
2395 git_SHA1_Final(parano_sha1, &c);
2396 if (hashcmp(sha1, parano_sha1) != 0)
2397 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 2398
e9039dd3 2399 close_sha1_file(fd);
0fcfd160 2400
bbac7311
NP
2401 if (mtime) {
2402 struct utimbuf utb;
2403 utb.actime = mtime;
2404 utb.modtime = mtime;
2405 if (utime(tmpfile, &utb) < 0)
2406 warning("failed utime() on %s: %s",
2407 tmpfile, strerror(errno));
2408 }
2409
230f1322 2410 return move_temp_to_file(tmpfile, filename);
0fcfd160 2411}
8237b185 2412
c00e657d 2413int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
bbac7311
NP
2414{
2415 unsigned char sha1[20];
2416 char hdr[32];
2417 int hdrlen;
2418
2419 /* Normally if we have it in the pack then we do not bother writing
2420 * it out into .git/objects/??/?{38} file.
2421 */
2422 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2423 if (returnsha1)
2424 hashcpy(returnsha1, sha1);
2425 if (has_sha1_file(sha1))
2426 return 0;
2427 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2428}
2429
2430int force_object_loose(const unsigned char *sha1, time_t mtime)
2431{
bbac7311
NP
2432 void *buf;
2433 unsigned long len;
2434 enum object_type type;
2435 char hdr[32];
2436 int hdrlen;
1fb23e65 2437 int ret;
bbac7311 2438
c529d75a 2439 if (has_loose_object(sha1))
bbac7311
NP
2440 return 0;
2441 buf = read_packed_sha1(sha1, &type, &len);
2442 if (!buf)
2443 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2444 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1fb23e65
BS
2445 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2446 free(buf);
2447
2448 return ret;
bbac7311
NP
2449}
2450
bf592c50
DB
2451int has_pack_index(const unsigned char *sha1)
2452{
2453 struct stat st;
2454 if (stat(sha1_pack_index_name(sha1), &st))
2455 return 0;
2456 return 1;
bf592c50
DB
2457}
2458
cd673c1f
JH
2459int has_sha1_pack(const unsigned char *sha1)
2460{
2461 struct pack_entry e;
2462 return find_pack_entry(sha1, &e);
2463}
2464
8237b185
DB
2465int has_sha1_file(const unsigned char *sha1)
2466{
1f688557
JH
2467 struct pack_entry e;
2468
cd673c1f 2469 if (find_pack_entry(sha1, &e))
1f688557 2470 return 1;
c529d75a 2471 return has_loose_object(sha1);
8237b185 2472}
74400e71 2473
43df4f86
DP
2474static int index_mem(unsigned char *sha1, void *buf, size_t size,
2475 int write_object, enum object_type type, const char *path)
e7332f96 2476{
6c510bee 2477 int ret, re_allocated = 0;
74400e71 2478
7672db20 2479 if (!type)
edaec3fb 2480 type = OBJ_BLOB;
6c510bee
LT
2481
2482 /*
2483 * Convert blobs to git internal format
2484 */
43df4f86 2485 if ((type == OBJ_BLOB) && path) {
f285a2d7 2486 struct strbuf nbuf = STRBUF_INIT;
21e5ad50
SP
2487 if (convert_to_git(path, buf, size, &nbuf,
2488 write_object ? safe_crlf : 0)) {
b315c5c0 2489 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2490 re_allocated = 1;
2491 }
2492 }
2493
7672db20 2494 if (write_object)
edaec3fb 2495 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2496 else
edaec3fb 2497 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 2498 if (re_allocated)
6c510bee 2499 free(buf);
43df4f86
DP
2500 return ret;
2501}
2502
ea68b0ce
DP
2503#define SMALL_FILE_SIZE (32*1024)
2504
43df4f86
DP
2505int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2506 enum object_type type, const char *path)
2507{
2508 int ret;
2509 size_t size = xsize_t(st->st_size);
2510
2511 if (!S_ISREG(st->st_mode)) {
f285a2d7 2512 struct strbuf sbuf = STRBUF_INIT;
43df4f86
DP
2513 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2514 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2515 type, path);
2516 else
2517 ret = -1;
2518 strbuf_release(&sbuf);
08bda208
DP
2519 } else if (!size) {
2520 ret = index_mem(sha1, NULL, size, write_object, type, path);
ea68b0ce
DP
2521 } else if (size <= SMALL_FILE_SIZE) {
2522 char *buf = xmalloc(size);
2523 if (size == read_in_full(fd, buf, size))
2524 ret = index_mem(sha1, buf, size, write_object, type,
2525 path);
2526 else
2527 ret = error("short read %s", strerror(errno));
2528 free(buf);
08bda208 2529 } else {
43df4f86
DP
2530 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2531 ret = index_mem(sha1, buf, size, write_object, type, path);
aac17941 2532 munmap(buf, size);
08bda208 2533 }
43df4f86 2534 close(fd);
aac17941 2535 return ret;
74400e71 2536}
ec1fcc16
JH
2537
2538int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2539{
2540 int fd;
b760d3aa 2541 struct strbuf sb = STRBUF_INIT;
ec1fcc16
JH
2542
2543 switch (st->st_mode & S_IFMT) {
2544 case S_IFREG:
2545 fd = open(path, O_RDONLY);
2546 if (fd < 0)
2547 return error("open(\"%s\"): %s", path,
2548 strerror(errno));
53bca91a 2549 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2550 return error("%s: failed to insert into database",
2551 path);
2552 break;
2553 case S_IFLNK:
b760d3aa 2554 if (strbuf_readlink(&sb, path, st->st_size)) {
ec1fcc16 2555 char *errstr = strerror(errno);
ec1fcc16
JH
2556 return error("readlink(\"%s\"): %s", path,
2557 errstr);
2558 }
abdc3fc8 2559 if (!write_object)
b760d3aa
LT
2560 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2561 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
ec1fcc16
JH
2562 return error("%s: failed to insert into database",
2563 path);
b760d3aa 2564 strbuf_release(&sb);
ec1fcc16 2565 break;
f35a6d3b
LT
2566 case S_IFDIR:
2567 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2568 default:
2569 return error("%s: unsupported file type", path);
2570 }
2571 return 0;
2572}
a69e5429
JH
2573
2574int read_pack_header(int fd, struct pack_header *header)
2575{
c697ad14
HO
2576 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2577 /* "eof before pack header was fully read" */
2578 return PH_ERROR_EOF;
2579
a69e5429
JH
2580 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2581 /* "protocol error (pack signature mismatch detected)" */
2582 return PH_ERROR_PACK_SIGNATURE;
2583 if (!pack_version_ok(header->hdr_version))
2584 /* "protocol error (pack version unsupported)" */
2585 return PH_ERROR_PROTOCOL;
2586 return 0;
2587}
40d52ff7
JK
2588
2589void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
2590{
2591 enum object_type type = sha1_object_info(sha1, NULL);
2592 if (type < 0)
2593 die("%s is not a valid object", sha1_to_hex(sha1));
2594 if (type != expect)
2595 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
2596 typename(expect));
2597}