Merge branch 'maint-1.7.11' into maint
[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"
4dd1fbc7 14#include "run-command.h"
8e440259
PE
15#include "tag.h"
16#include "tree.h"
c879daa2 17#include "tree-walk.h"
f35a6d3b 18#include "refs.h"
70f5d5d3 19#include "pack-revindex.h"
628522ec 20#include "sha1-lookup.h"
568508e7 21#include "bulk-checkin.h"
090ea126 22#include "streaming.h"
0fcfd160 23
144bde78
LT
24#ifndef O_NOATIME
25#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
26#define O_NOATIME 01000000
27#else
28#define O_NOATIME 0
29#endif
30#endif
31
28bd70d8
JN
32#define SZ_FMT PRIuMAX
33static inline uintmax_t sz_fmt(size_t s) { return s; }
e05db0fd 34
96f1e58f 35const unsigned char null_sha1[20];
88cd621d 36
c597ba80
NTND
37/*
38 * This is meant to hold a *small* number of objects that you would
39 * want read_sha1_file() to be able to return, but yet you do not want
40 * to write them into the object store (e.g. a browse-only
41 * application).
42 */
43static struct cached_object {
44 unsigned char sha1[20];
45 enum object_type type;
46 void *buf;
47 unsigned long size;
48} *cached_objects;
49static int cached_object_nr, cached_object_alloc;
50
51static struct cached_object empty_tree = {
dab0d410 52 EMPTY_TREE_SHA1_BIN_LITERAL,
c597ba80
NTND
53 OBJ_TREE,
54 "",
55 0
56};
57
c01f51cc
NTND
58static struct packed_git *last_found_pack;
59
c597ba80
NTND
60static struct cached_object *find_cached_object(const unsigned char *sha1)
61{
62 int i;
63 struct cached_object *co = cached_objects;
64
65 for (i = 0; i < cached_object_nr; i++, co++) {
66 if (!hashcmp(co->sha1, sha1))
67 return co;
68 }
69 if (!hashcmp(sha1, empty_tree.sha1))
70 return &empty_tree;
71 return NULL;
72}
73
90a6464b
JH
74int mkdir_in_gitdir(const char *path)
75{
76 if (mkdir(path, 0777)) {
77 int saved_errno = errno;
78 struct stat st;
79 struct strbuf sb = STRBUF_INIT;
80
81 if (errno != EEXIST)
82 return -1;
83 /*
84 * Are we looking at a path in a symlinked worktree
85 * whose original repository does not yet have it?
86 * e.g. .git/rr-cache pointing at its original
87 * repository in which the user hasn't performed any
88 * conflict resolution yet?
89 */
90 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
91 strbuf_readlink(&sb, path, st.st_size) ||
92 !is_absolute_path(sb.buf) ||
93 mkdir(sb.buf, 0777)) {
94 strbuf_release(&sb);
95 errno = saved_errno;
96 return -1;
97 }
98 strbuf_release(&sb);
99 }
100 return adjust_shared_perm(path);
101}
102
b2cb9425
JH
103int safe_create_leading_directories(char *path)
104{
8385abfd 105 char *pos = path + offset_1st_component(path);
67d42212
JR
106 struct stat st;
107
b2cb9425
JH
108 while (pos) {
109 pos = strchr(pos, '/');
110 if (!pos)
111 break;
5f0bdf50
JH
112 while (*++pos == '/')
113 ;
114 if (!*pos)
115 break;
116 *--pos = '\0';
67d42212
JR
117 if (!stat(path, &st)) {
118 /* path exists */
119 if (!S_ISDIR(st.st_mode)) {
b2cb9425 120 *pos = '/';
67d42212 121 return -3;
b2cb9425 122 }
457f06d6 123 }
67d42212
JR
124 else if (mkdir(path, 0777)) {
125 *pos = '/';
126 return -1;
127 }
457f06d6
JS
128 else if (adjust_shared_perm(path)) {
129 *pos = '/';
130 return -2;
131 }
b2cb9425
JH
132 *pos++ = '/';
133 }
134 return 0;
135}
723c31fe 136
8e21d63b
JK
137int safe_create_leading_directories_const(const char *path)
138{
139 /* path points to cache entries, so xstrdup before messing with it */
140 char *buf = xstrdup(path);
141 int result = safe_create_leading_directories(buf);
142 free(buf);
143 return result;
144}
145
ace1534d
JH
146static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
147{
148 int i;
149 for (i = 0; i < 20; i++) {
150 static char hex[] = "0123456789abcdef";
151 unsigned int val = sha1[i];
152 char *pos = pathbuf + i*2 + (i > 0);
153 *pos++ = hex[val >> 4];
154 *pos = hex[val & 0xf];
155 }
156}
157
0fcfd160
LT
158/*
159 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 160 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 161 * filename.
ace1534d
JH
162 *
163 * Also note that this returns the location for creating. Reading
164 * SHA1 file can happen from any alternate directory listed in the
d19938ab 165 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 166 * the primary object database.
0fcfd160
LT
167 */
168char *sha1_file_name(const unsigned char *sha1)
169{
560fb6a1
JK
170 static char buf[PATH_MAX];
171 const char *objdir;
172 int len;
0fcfd160 173
560fb6a1
JK
174 objdir = get_object_directory();
175 len = strlen(objdir);
176
177 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
178 if (len + 43 > PATH_MAX)
179 die("insanely long object directory %s", objdir);
180 memcpy(buf, objdir, len);
181 buf[len] = '/';
182 buf[len+3] = '/';
183 buf[len+42] = '\0';
184 fill_sha1_path(buf + len + 1, sha1);
185 return buf;
0fcfd160
LT
186}
187
633f43e1 188static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 189 char **name, char **base, const char *which)
bf592c50
DB
190{
191 static const char hex[] = "0123456789abcdef";
633f43e1 192 char *buf;
bf592c50
DB
193 int i;
194
633f43e1 195 if (!*base) {
bf592c50
DB
196 const char *sha1_file_directory = get_object_directory();
197 int len = strlen(sha1_file_directory);
633f43e1 198 *base = xmalloc(len + 60);
6eec46bd
JH
199 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
200 sha1_file_directory, which);
633f43e1 201 *name = *base + len + 11;
bf592c50
DB
202 }
203
633f43e1 204 buf = *name;
bf592c50
DB
205
206 for (i = 0; i < 20; i++) {
207 unsigned int val = *sha1++;
208 *buf++ = hex[val >> 4];
209 *buf++ = hex[val & 0xf];
210 }
a6080a0a 211
633f43e1 212 return *base;
bf592c50
DB
213}
214
633f43e1 215char *sha1_pack_name(const unsigned char *sha1)
bf592c50 216{
633f43e1 217 static char *name, *base;
bf592c50 218
6eec46bd 219 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 220}
bf592c50 221
633f43e1
HO
222char *sha1_pack_index_name(const unsigned char *sha1)
223{
224 static char *name, *base;
a6080a0a 225
6eec46bd 226 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
227}
228
d5a63b99
JH
229struct alternate_object_database *alt_odb_list;
230static struct alternate_object_database **alt_odb_tail;
ace1534d 231
f4e51683 232static int git_open_noatime(const char *name);
c2f493a4 233
ddd5d056
JH
234/*
235 * Prepare alternate object database registry.
d5a63b99
JH
236 *
237 * The variable alt_odb_list points at the list of struct
238 * alternate_object_database. The elements on this list come from
239 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
240 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
241 * whose contents is similar to that environment variable but can be
242 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
243 * contains "/the/directory/corresponding/to/.git/objects/...", while
244 * its name points just after the slash at the end of ".git/objects/"
245 * in the example above, and has enough space to hold 40-byte hex
246 * SHA1, an extra slash for the first level indirection, and the
247 * terminating NUL.
ddd5d056 248 */
c2f493a4 249static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 250{
1494e038 251 const char *objdir = get_object_directory();
c2f493a4
MW
252 struct alternate_object_database *ent;
253 struct alternate_object_database *alt;
5bdf0a84
HW
254 int pfxlen, entlen;
255 struct strbuf pathbuf = STRBUF_INIT;
d5a63b99 256
85dadc38 257 if (!is_absolute_path(entry) && relative_base) {
5bdf0a84
HW
258 strbuf_addstr(&pathbuf, real_path(relative_base));
259 strbuf_addch(&pathbuf, '/');
c2f493a4 260 }
5bdf0a84 261 strbuf_add(&pathbuf, entry, len);
c2f493a4 262
5bdf0a84
HW
263 normalize_path_copy(pathbuf.buf, pathbuf.buf);
264
265 pfxlen = strlen(pathbuf.buf);
266
267 /*
268 * The trailing slash after the directory name is given by
269 * this function at the end. Remove duplicates.
270 */
271 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
272 pfxlen -= 1;
273
274 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
275 ent = xmalloc(sizeof(*ent) + entlen);
276 memcpy(ent->base, pathbuf.buf, pfxlen);
277 strbuf_release(&pathbuf);
c2f493a4
MW
278
279 ent->name = ent->base + pfxlen + 1;
280 ent->base[pfxlen + 3] = '/';
281 ent->base[pfxlen] = ent->base[entlen-1] = 0;
282
283 /* Detect cases where alternate disappeared */
90b4a71c 284 if (!is_directory(ent->base)) {
c2f493a4
MW
285 error("object directory %s does not exist; "
286 "check .git/objects/info/alternates.",
287 ent->base);
288 free(ent);
289 return -1;
290 }
291
292 /* Prevent the common mistake of listing the same
293 * thing twice, or object directory itself.
294 */
295 for (alt = alt_odb_list; alt; alt = alt->next) {
296 if (!memcmp(ent->base, alt->base, pfxlen)) {
297 free(ent);
298 return -1;
299 }
300 }
cb2912c3 301 if (!strcmp(ent->base, objdir)) {
c2f493a4
MW
302 free(ent);
303 return -1;
304 }
305
306 /* add the alternate entry */
307 *alt_odb_tail = ent;
308 alt_odb_tail = &(ent->next);
309 ent->next = NULL;
310
311 /* recursively add alternates */
312 read_info_alternates(ent->base, depth + 1);
313
314 ent->base[pfxlen] = '/';
315
316 return 0;
317}
318
319static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
320 const char *relative_base, int depth)
321{
322 const char *cp, *last;
323
324 if (depth > 5) {
325 error("%s: ignoring alternate object stores, nesting too deep.",
326 relative_base);
327 return;
328 }
329
d5a63b99 330 last = alt;
9577e7e3
JH
331 while (last < ep) {
332 cp = last;
333 if (cp < ep && *cp == '#') {
334 while (cp < ep && *cp != sep)
335 cp++;
336 last = cp + 1;
337 continue;
338 }
c2f493a4
MW
339 while (cp < ep && *cp != sep)
340 cp++;
d5a63b99 341 if (last != cp) {
85dadc38 342 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
343 error("%s: ignoring relative alternate object store %s",
344 relative_base, last);
345 } else {
346 link_alt_odb_entry(last, cp - last,
347 relative_base, depth);
1494e038 348 }
d5a63b99 349 }
9577e7e3 350 while (cp < ep && *cp == sep)
d5a63b99
JH
351 cp++;
352 last = cp;
9577e7e3 353 }
d5a63b99
JH
354}
355
5e73633d 356void read_info_alternates(const char * relative_base, int depth)
d5a63b99 357{
9577e7e3 358 char *map;
dc49cd76 359 size_t mapsz;
d5a63b99 360 struct stat st;
9cb18f56
JM
361 const char alt_file_name[] = "info/alternates";
362 /* Given that relative_base is no longer than PATH_MAX,
363 ensure that "path" has enough space to append "/", the
364 file name, "info/alternates", and a trailing NUL. */
365 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 366 int fd;
d5a63b99 367
9cb18f56 368 sprintf(path, "%s/%s", relative_base, alt_file_name);
f4e51683 369 fd = git_open_noatime(path);
d5a63b99
JH
370 if (fd < 0)
371 return;
372 if (fstat(fd, &st) || (st.st_size == 0)) {
373 close(fd);
9a217f2a 374 return;
ace1534d 375 }
dc49cd76
SP
376 mapsz = xsize_t(st.st_size);
377 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 378 close(fd);
d5a63b99 379
dc49cd76 380 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 381
dc49cd76 382 munmap(map, mapsz);
ace1534d
JH
383}
384
bef70b22
DB
385void add_to_alternates_file(const char *reference)
386{
387 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
acd3b9ec 388 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
e6baf4a1 389 char *alt = mkpath("%s\n", reference);
bef70b22
DB
390 write_or_die(fd, alt, strlen(alt));
391 if (commit_lock_file(lock))
392 die("could not close alternates file");
393 if (alt_odb_tail)
394 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
395}
396
d79796bc
JH
397void foreach_alt_odb(alt_odb_fn fn, void *cb)
398{
399 struct alternate_object_database *ent;
400
401 prepare_alt_odb();
402 for (ent = alt_odb_list; ent; ent = ent->next)
403 if (fn(ent, cb))
404 return;
405}
406
c2f493a4
MW
407void prepare_alt_odb(void)
408{
554fe20d 409 const char *alt;
c2f493a4 410
7dc24aa5
SP
411 if (alt_odb_tail)
412 return;
413
c2f493a4
MW
414 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
415 if (!alt) alt = "";
416
c2f493a4 417 alt_odb_tail = &alt_odb_list;
80ba074f 418 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
419
420 read_info_alternates(get_object_directory(), 0);
421}
422
0f4dc14a 423static int has_loose_object_local(const unsigned char *sha1)
ace1534d 424{
ace1534d 425 char *name = sha1_file_name(sha1);
0f4dc14a
BC
426 return !access(name, F_OK);
427}
ace1534d 428
0f4dc14a
BC
429int has_loose_object_nonlocal(const unsigned char *sha1)
430{
431 struct alternate_object_database *alt;
9a217f2a 432 prepare_alt_odb();
d5a63b99 433 for (alt = alt_odb_list; alt; alt = alt->next) {
0f4dc14a 434 fill_sha1_path(alt->name, sha1);
c529d75a
LT
435 if (!access(alt->base, F_OK))
436 return 1;
ace1534d 437 }
c529d75a 438 return 0;
ace1534d
JH
439}
440
0f4dc14a
BC
441static int has_loose_object(const unsigned char *sha1)
442{
443 return has_loose_object_local(sha1) ||
444 has_loose_object_nonlocal(sha1);
445}
446
60bb8b14 447static unsigned int pack_used_ctr;
a53128b6
SP
448static unsigned int pack_mmap_calls;
449static unsigned int peak_pack_open_windows;
450static unsigned int pack_open_windows;
c7934306
SP
451static unsigned int pack_open_fds;
452static unsigned int pack_max_fds;
a53128b6 453static size_t peak_pack_mapped;
60bb8b14 454static size_t pack_mapped;
9a217f2a 455struct packed_git *packed_git;
1f688557 456
b79d18c9 457void pack_report(void)
a53128b6
SP
458{
459 fprintf(stderr,
e05db0fd
PR
460 "pack_report: getpagesize() = %10" SZ_FMT "\n"
461 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
462 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
463 sz_fmt(getpagesize()),
464 sz_fmt(packed_git_window_size),
465 sz_fmt(packed_git_limit));
a53128b6
SP
466 fprintf(stderr,
467 "pack_report: pack_used_ctr = %10u\n"
468 "pack_report: pack_mmap_calls = %10u\n"
469 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
470 "pack_report: pack_mapped = "
471 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
472 pack_used_ctr,
473 pack_mmap_calls,
474 pack_open_windows, peak_pack_open_windows,
9e42d6a1 475 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
476}
477
42873078 478static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
479{
480 void *idx_map;
42873078 481 struct pack_idx_header *hdr;
dc49cd76 482 size_t idx_size;
74e34e1f 483 uint32_t version, nr, i, *index;
f4e51683 484 int fd = git_open_noatime(path);
1f688557 485 struct stat st;
42873078 486
1f688557
JH
487 if (fd < 0)
488 return -1;
489 if (fstat(fd, &st)) {
490 close(fd);
491 return -1;
492 }
dc49cd76 493 idx_size = xsize_t(st.st_size);
2d88451b
SP
494 if (idx_size < 4 * 256 + 20 + 20) {
495 close(fd);
496 return error("index file %s is too small", path);
497 }
c4712e45 498 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 499 close(fd);
1f688557 500
42873078
NP
501 hdr = idx_map;
502 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
503 version = ntohl(hdr->idx_version);
504 if (version < 2 || version > 2) {
505 munmap(idx_map, idx_size);
6e1c2344 506 return error("index file %s is version %"PRIu32
74e34e1f
NP
507 " and is not supported by this binary"
508 " (try upgrading GIT to a newer version)",
509 path, version);
510 }
511 } else
512 version = 1;
df1b059d 513
1f688557 514 nr = 0;
42873078 515 index = idx_map;
74e34e1f
NP
516 if (version > 1)
517 index += 2; /* skip index header */
1f688557 518 for (i = 0; i < 256; i++) {
326bf396 519 uint32_t n = ntohl(index[i]);
2d88451b
SP
520 if (n < nr) {
521 munmap(idx_map, idx_size);
df1b059d 522 return error("non-monotonic index %s", path);
2d88451b 523 }
1f688557
JH
524 nr = n;
525 }
526
74e34e1f
NP
527 if (version == 1) {
528 /*
529 * Total size:
530 * - 256 index entries 4 bytes each
531 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
532 * - 20-byte SHA1 of the packfile
533 * - 20-byte SHA1 file checksum
534 */
535 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
536 munmap(idx_map, idx_size);
eef427a0 537 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
538 }
539 } else if (version == 2) {
540 /*
541 * Minimum size:
542 * - 8 bytes of header
543 * - 256 index entries 4 bytes each
544 * - 20-byte sha1 entry * nr
545 * - 4-byte crc entry * nr
546 * - 4-byte offset entry * nr
547 * - 20-byte SHA1 of the packfile
548 * - 20-byte SHA1 file checksum
549 * And after the 4-byte offset table might be a
550 * variable sized table containing 8-byte entries
551 * for offsets larger than 2^31.
552 */
553 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
554 unsigned long max_size = min_size;
555 if (nr)
556 max_size += (nr - 1)*8;
557 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 558 munmap(idx_map, idx_size);
eef427a0 559 return error("wrong index v2 file size in %s", path);
74e34e1f 560 }
7109c889
JH
561 if (idx_size != min_size &&
562 /*
563 * make sure we can deal with large pack offsets.
564 * 31-bit signed offset won't be enough, neither
565 * 32-bit unsigned one will be.
566 */
567 (sizeof(off_t) <= 4)) {
568 munmap(idx_map, idx_size);
569 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 570 }
2d88451b 571 }
1f688557 572
74e34e1f 573 p->index_version = version;
42873078
NP
574 p->index_data = idx_map;
575 p->index_size = idx_size;
57059091 576 p->num_objects = nr;
1f688557
JH
577 return 0;
578}
579
bc8e478a 580int open_pack_index(struct packed_git *p)
d079837e
SP
581{
582 char *idx_name;
583 int ret;
584
585 if (p->index_data)
586 return 0;
587
588 idx_name = xstrdup(p->pack_name);
589 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
590 ret = check_packed_git_idx(idx_name, p);
591 free(idx_name);
592 return ret;
593}
594
11daf39b
SP
595static void scan_windows(struct packed_git *p,
596 struct packed_git **lru_p,
597 struct pack_window **lru_w,
598 struct pack_window **lru_l)
1f688557 599{
11daf39b
SP
600 struct pack_window *w, *w_l;
601
602 for (w_l = NULL, w = p->windows; w; w = w->next) {
603 if (!w->inuse_cnt) {
604 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
605 *lru_p = p;
606 *lru_w = w;
607 *lru_l = w_l;
54044bf8 608 }
54044bf8 609 }
11daf39b 610 w_l = w;
f9253394 611 }
11daf39b
SP
612}
613
d1efefa4 614static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
615{
616 struct packed_git *p, *lru_p = NULL;
617 struct pack_window *lru_w = NULL, *lru_l = NULL;
618
619 if (current)
620 scan_windows(current, &lru_p, &lru_w, &lru_l);
621 for (p = packed_git; p; p = p->next)
622 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
623 if (lru_p) {
624 munmap(lru_w->base, lru_w->len);
625 pack_mapped -= lru_w->len;
626 if (lru_l)
627 lru_l->next = lru_w->next;
628 else {
629 lru_p->windows = lru_w->next;
d131b7af
SP
630 if (!lru_p->windows && lru_p->pack_fd != -1
631 && lru_p->pack_fd != keep_fd) {
54044bf8 632 close(lru_p->pack_fd);
c7934306 633 pack_open_fds--;
54044bf8
SP
634 lru_p->pack_fd = -1;
635 }
636 }
637 free(lru_w);
a53128b6 638 pack_open_windows--;
54044bf8
SP
639 return 1;
640 }
641 return 0;
f9253394
JH
642}
643
d1efefa4 644void release_pack_memory(size_t need, int fd)
97bfeb34
SP
645{
646 size_t cur = pack_mapped;
d1efefa4 647 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
648 ; /* nothing */
649}
650
58ecbd5e
JN
651void *xmmap(void *start, size_t length,
652 int prot, int flags, int fd, off_t offset)
653{
654 void *ret = mmap(start, length, prot, flags, fd, offset);
655 if (ret == MAP_FAILED) {
656 if (!length)
657 return NULL;
658 release_pack_memory(length, fd);
659 ret = mmap(start, length, prot, flags, fd, offset);
660 if (ret == MAP_FAILED)
661 die_errno("Out of memory? mmap failed");
662 }
663 return ret;
664}
665
c9ced051
SP
666void close_pack_windows(struct packed_git *p)
667{
668 while (p->windows) {
669 struct pack_window *w = p->windows;
670
671 if (w->inuse_cnt)
672 die("pack '%s' still has open windows to it",
673 p->pack_name);
674 munmap(w->base, w->len);
675 pack_mapped -= w->len;
676 pack_open_windows--;
677 p->windows = w->next;
678 free(w);
679 }
680}
681
03e79c88 682void unuse_pack(struct pack_window **w_cursor)
f9253394 683{
03e79c88
SP
684 struct pack_window *w = *w_cursor;
685 if (w) {
686 w->inuse_cnt--;
687 *w_cursor = NULL;
688 }
1f688557
JH
689}
690
fa5fc15d
SP
691void close_pack_index(struct packed_git *p)
692{
693 if (p->index_data) {
694 munmap((void *)p->index_data, p->index_size);
695 p->index_data = NULL;
696 }
697}
698
c74faea1
NP
699/*
700 * This is used by git-repack in case a newly created pack happens to
701 * contain the same set of objects as an existing one. In that case
702 * the resulting file might be different even if its name would be the
703 * same. It is best to close any reference to the old pack before it is
704 * replaced on disk. Of course no index pointers nor windows for given pack
705 * must subsist at this point. If ever objects from this pack are requested
706 * again, the new version of the pack will be reinitialized through
707 * reprepare_packed_git().
708 */
709void free_pack_by_name(const char *pack_name)
710{
711 struct packed_git *p, **pp = &packed_git;
712
713 while (*pp) {
714 p = *pp;
715 if (strcmp(pack_name, p->pack_name) == 0) {
fa3a0c94 716 clear_delta_base_cache();
c74faea1 717 close_pack_windows(p);
c7934306 718 if (p->pack_fd != -1) {
c74faea1 719 close(p->pack_fd);
c7934306
SP
720 pack_open_fds--;
721 }
fa5fc15d 722 close_pack_index(p);
c74faea1
NP
723 free(p->bad_object_sha1);
724 *pp = p->next;
c01f51cc
NTND
725 if (last_found_pack == p)
726 last_found_pack = NULL;
c74faea1
NP
727 free(p);
728 return;
729 }
730 pp = &p->next;
731 }
732}
733
3cf8b462
SP
734/*
735 * Do not call this directly as this leaks p->pack_fd on error return;
736 * call open_packed_git() instead.
737 */
738static int open_packed_git_1(struct packed_git *p)
1f688557 739{
9bc879c1
SP
740 struct stat st;
741 struct pack_header hdr;
742 unsigned char sha1[20];
743 unsigned char *idx_sha1;
2c039da8 744 long fd_flag;
9bc879c1 745
d079837e
SP
746 if (!p->index_data && open_pack_index(p))
747 return error("packfile %s index unavailable", p->pack_name);
748
c7934306
SP
749 if (!pack_max_fds) {
750 struct rlimit lim;
751 unsigned int max_fds;
752
753 if (getrlimit(RLIMIT_NOFILE, &lim))
754 die_errno("cannot get RLIMIT_NOFILE");
755
756 max_fds = lim.rlim_cur;
757
758 /* Save 3 for stdin/stdout/stderr, 22 for work */
759 if (25 < max_fds)
760 pack_max_fds = max_fds - 25;
761 else
762 pack_max_fds = 1;
763 }
764
765 while (pack_max_fds <= pack_open_fds && unuse_one_window(NULL, -1))
766 ; /* nothing */
767
f4e51683 768 p->pack_fd = git_open_noatime(p->pack_name);
9bc879c1 769 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 770 return -1;
c7934306 771 pack_open_fds++;
9bc879c1
SP
772
773 /* If we created the struct before we had the pack we lack size. */
bf592c50 774 if (!p->pack_size) {
bf592c50 775 if (!S_ISREG(st.st_mode))
072db278 776 return error("packfile %s not a regular file", p->pack_name);
bf592c50 777 p->pack_size = st.st_size;
9bc879c1 778 } else if (p->pack_size != st.st_size)
072db278 779 return error("packfile %s size changed", p->pack_name);
9bc879c1 780
2c039da8
JH
781 /* We leave these file descriptors open with sliding mmap;
782 * there is no point keeping them open across exec(), though.
783 */
784 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
785 if (fd_flag < 0)
072db278 786 return error("cannot determine file descriptor flags");
2c039da8
JH
787 fd_flag |= FD_CLOEXEC;
788 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 789 return error("cannot set FD_CLOEXEC");
2c039da8 790
9bc879c1 791 /* Verify we recognize this pack file format. */
e6e2bd62 792 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 793 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 794 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 795 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 796 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
797 return error("packfile %s is version %"PRIu32" and not"
798 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
799 p->pack_name, ntohl(hdr.hdr_version));
800
801 /* Verify the pack matches its index. */
57059091 802 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
803 return error("packfile %s claims to have %"PRIu32" objects"
804 " while index indicates %"PRIu32" objects",
57059091
NP
805 p->pack_name, ntohl(hdr.hdr_entries),
806 p->num_objects);
9bc879c1 807 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 808 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 809 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 810 return error("packfile %s signature is unavailable", p->pack_name);
42873078 811 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 812 if (hashcmp(sha1, idx_sha1))
072db278
SP
813 return error("packfile %s does not match index", p->pack_name);
814 return 0;
9bc879c1
SP
815}
816
3cf8b462
SP
817static int open_packed_git(struct packed_git *p)
818{
819 if (!open_packed_git_1(p))
820 return 0;
821 if (p->pack_fd != -1) {
822 close(p->pack_fd);
c7934306 823 pack_open_fds--;
3cf8b462
SP
824 p->pack_fd = -1;
825 }
826 return -1;
827}
828
c4001d92 829static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
830{
831 /* We must promise at least 20 bytes (one hash) after the
832 * offset is available from this window, otherwise the offset
833 * is not actually in this window and a different window (which
834 * has that one hash excess) must be used. This is to support
835 * the object header and delta base parsing routines below.
836 */
837 off_t win_off = win->offset;
838 return win_off <= offset
839 && (offset + 20) <= (win_off + win->len);
840}
841
4b25d091 842unsigned char *use_pack(struct packed_git *p,
03e79c88 843 struct pack_window **w_cursor,
c4001d92 844 off_t offset,
ef49a7a0 845 unsigned long *left)
9bc879c1 846{
60bb8b14 847 struct pack_window *win = *w_cursor;
03e79c88 848
a9d98a14 849 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
850 * pointless to ask for an offset into the middle of that
851 * hash, and the in_window function above wouldn't match
852 * don't allow an offset too close to the end of the file.
853 */
d131b7af
SP
854 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
855 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
856 if (offset > (p->pack_size - 20))
857 die("offset beyond end of packfile (truncated pack?)");
858
859 if (!win || !in_window(win, offset)) {
860 if (win)
861 win->inuse_cnt--;
862 for (win = p->windows; win; win = win->next) {
863 if (in_window(win, offset))
864 break;
865 }
866 if (!win) {
78a28df9 867 size_t window_align = packed_git_window_size / 2;
dc49cd76 868 off_t len;
d131b7af
SP
869
870 if (p->pack_fd == -1 && open_packed_git(p))
871 die("packfile %s cannot be accessed", p->pack_name);
872
60bb8b14 873 win = xcalloc(1, sizeof(*win));
78a28df9 874 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
875 len = p->pack_size - win->offset;
876 if (len > packed_git_window_size)
877 len = packed_git_window_size;
878 win->len = (size_t)len;
60bb8b14 879 pack_mapped += win->len;
11daf39b 880 while (packed_git_limit < pack_mapped
d1efefa4 881 && unuse_one_window(p, p->pack_fd))
60bb8b14 882 ; /* nothing */
c4712e45 883 win->base = xmmap(NULL, win->len,
60bb8b14
SP
884 PROT_READ, MAP_PRIVATE,
885 p->pack_fd, win->offset);
886 if (win->base == MAP_FAILED)
73b4e4be
SP
887 die("packfile %s cannot be mapped: %s",
888 p->pack_name,
889 strerror(errno));
d131b7af
SP
890 if (!win->offset && win->len == p->pack_size
891 && !p->do_not_close) {
892 close(p->pack_fd);
893 pack_open_fds--;
894 p->pack_fd = -1;
895 }
a53128b6
SP
896 pack_mmap_calls++;
897 pack_open_windows++;
898 if (pack_mapped > peak_pack_mapped)
899 peak_pack_mapped = pack_mapped;
900 if (pack_open_windows > peak_pack_open_windows)
901 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
902 win->next = p->windows;
903 p->windows = win;
904 }
1f688557 905 }
03e79c88
SP
906 if (win != *w_cursor) {
907 win->last_used = pack_used_ctr++;
908 win->inuse_cnt++;
909 *w_cursor = win;
910 }
60bb8b14 911 offset -= win->offset;
03e79c88 912 if (left)
dc49cd76 913 *left = win->len - xsize_t(offset);
03e79c88 914 return win->base + offset;
1f688557
JH
915}
916
27d69a46
NP
917static struct packed_git *alloc_packed_git(int extra)
918{
919 struct packed_git *p = xmalloc(sizeof(*p) + extra);
920 memset(p, 0, sizeof(*p));
921 p->pack_fd = -1;
922 return p;
923}
924
e0500293
JN
925static void try_to_free_pack_memory(size_t size)
926{
927 release_pack_memory(size, -1);
928}
929
42873078 930struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557 931{
e0500293 932 static int have_set_try_to_free_routine;
1f688557 933 struct stat st;
27d69a46 934 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 935
e0500293
JN
936 if (!have_set_try_to_free_routine) {
937 have_set_try_to_free_routine = 1;
938 set_try_to_free_routine(try_to_free_pack_memory);
939 }
940
42873078
NP
941 /*
942 * Make sure a corresponding .pack file exists and that
943 * the index looks sane.
944 */
945 path_len -= strlen(".idx");
27d69a46
NP
946 if (path_len < 1) {
947 free(p);
1f688557 948 return NULL;
27d69a46 949 }
42873078 950 memcpy(p->pack_name, path, path_len);
8d25931d
BC
951
952 strcpy(p->pack_name + path_len, ".keep");
953 if (!access(p->pack_name, F_OK))
954 p->pack_keep = 1;
955
42873078 956 strcpy(p->pack_name + path_len, ".pack");
d079837e 957 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 958 free(p);
1f688557
JH
959 return NULL;
960 }
42873078 961
1f688557
JH
962 /* ok, it looks sane as far as we can check without
963 * actually mapping the pack file.
964 */
1f688557 965 p->pack_size = st.st_size;
9d835df2 966 p->pack_local = local;
b867092f 967 p->mtime = st.st_mtime;
42873078
NP
968 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
969 hashclr(p->sha1);
1f688557
JH
970 return p;
971}
972
7b64469a 973struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
c508df5e 974{
42873078 975 const char *path = sha1_pack_name(sha1);
27d69a46 976 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 977
27d69a46
NP
978 strcpy(p->pack_name, path);
979 hashcpy(p->sha1, sha1);
42873078
NP
980 if (check_packed_git_idx(idx_path, p)) {
981 free(p);
bf592c50 982 return NULL;
42873078 983 }
bf592c50 984
bf592c50
DB
985 return p;
986}
987
988void install_packed_git(struct packed_git *pack)
989{
c7934306
SP
990 if (pack->pack_fd != -1)
991 pack_open_fds++;
992
bf592c50
DB
993 pack->next = packed_git;
994 packed_git = pack;
995}
996
9d835df2 997static void prepare_packed_git_one(char *objdir, int local)
1f688557 998{
9cb18f56
JM
999 /* Ensure that this buffer is large enough so that we can
1000 append "/pack/" without clobbering the stack even if
1001 strlen(objdir) were PATH_MAX. */
1002 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
1003 int len;
1004 DIR *dir;
1005 struct dirent *de;
1006
1007 sprintf(path, "%s/pack", objdir);
1008 len = strlen(path);
1009 dir = opendir(path);
b5b16990 1010 if (!dir) {
26125f6b 1011 if (errno != ENOENT)
bd2afde8 1012 error("unable to open object pack directory: %s: %s",
26125f6b 1013 path, strerror(errno));
1f688557 1014 return;
b5b16990 1015 }
1f688557
JH
1016 path[len++] = '/';
1017 while ((de = readdir(dir)) != NULL) {
1018 int namelen = strlen(de->d_name);
1019 struct packed_git *p;
1020
5bb1cda5 1021 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
1022 continue;
1023
9cb18f56
JM
1024 if (len + namelen + 1 > sizeof(path))
1025 continue;
1026
54a15a8d 1027 /* Don't reopen a pack we already have. */
1f688557 1028 strcpy(path + len, de->d_name);
86f7780c
JK
1029 for (p = packed_git; p; p = p->next) {
1030 if (!memcmp(path, p->pack_name, len + namelen - 4))
1031 break;
1032 }
1033 if (p)
1034 continue;
54a15a8d
SP
1035 /* See if it really is a valid .idx file with corresponding
1036 * .pack file that we can map.
1037 */
9d835df2 1038 p = add_packed_git(path, len + namelen, local);
1f688557
JH
1039 if (!p)
1040 continue;
625e9421 1041 install_packed_git(p);
1f688557 1042 }
5b35bcd5 1043 closedir(dir);
1f688557
JH
1044}
1045
b867092f
JH
1046static int sort_pack(const void *a_, const void *b_)
1047{
1048 struct packed_git *a = *((struct packed_git **)a_);
1049 struct packed_git *b = *((struct packed_git **)b_);
1050 int st;
1051
1052 /*
1053 * Local packs tend to contain objects specific to our
1054 * variant of the project than remote ones. In addition,
1055 * remote ones could be on a network mounted filesystem.
1056 * Favor local ones for these reasons.
1057 */
1058 st = a->pack_local - b->pack_local;
1059 if (st)
1060 return -st;
1061
1062 /*
1063 * Younger packs tend to contain more recent objects,
1064 * and more recent objects tend to get accessed more
1065 * often.
1066 */
1067 if (a->mtime < b->mtime)
1068 return 1;
1069 else if (a->mtime == b->mtime)
1070 return 0;
1071 return -1;
1072}
1073
1074static void rearrange_packed_git(void)
1075{
1076 struct packed_git **ary, *p;
1077 int i, n;
1078
1079 for (n = 0, p = packed_git; p; p = p->next)
1080 n++;
1081 if (n < 2)
1082 return;
1083
1084 /* prepare an array of packed_git for easier sorting */
1085 ary = xcalloc(n, sizeof(struct packed_git *));
1086 for (n = 0, p = packed_git; p; p = p->next)
1087 ary[n++] = p;
1088
1089 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1090
1091 /* link them back again */
1092 for (i = 0; i < n - 1; i++)
1093 ary[i]->next = ary[i + 1];
1094 ary[n - 1]->next = NULL;
1095 packed_git = ary[0];
1096
1097 free(ary);
1098}
1099
637cdd9d 1100static int prepare_packed_git_run_once = 0;
9a217f2a 1101void prepare_packed_git(void)
1f688557 1102{
d5a63b99 1103 struct alternate_object_database *alt;
1f688557 1104
637cdd9d 1105 if (prepare_packed_git_run_once)
1f688557 1106 return;
9d835df2 1107 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 1108 prepare_alt_odb();
d5a63b99 1109 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 1110 alt->name[-1] = 0;
9d835df2 1111 prepare_packed_git_one(alt->base, 0);
1494e038 1112 alt->name[-1] = '/';
1f688557 1113 }
b867092f 1114 rearrange_packed_git();
637cdd9d
JK
1115 prepare_packed_git_run_once = 1;
1116}
1117
fc04c412 1118void reprepare_packed_git(void)
637cdd9d 1119{
4b480c67 1120 discard_revindex();
637cdd9d
JK
1121 prepare_packed_git_run_once = 0;
1122 prepare_packed_git();
1f688557
JH
1123}
1124
8eca0b47
NP
1125static void mark_bad_packed_object(struct packed_git *p,
1126 const unsigned char *sha1)
1127{
1128 unsigned i;
1129 for (i = 0; i < p->num_bad_objects; i++)
1130 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1131 return;
1132 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1133 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1134 p->num_bad_objects++;
1135}
1136
b6c4cecc 1137static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
ac939109
NP
1138{
1139 struct packed_git *p;
1140 unsigned i;
1141
1142 for (p = packed_git; p; p = p->next)
1143 for (i = 0; i < p->num_bad_objects; i++)
1144 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
b6c4cecc
JH
1145 return p;
1146 return NULL;
ac939109
NP
1147}
1148
090ea126
NTND
1149/*
1150 * With an in-core object data in "map", rehash it to make sure the
1151 * object name actually matches "sha1" to detect object corruption.
1152 * With "map" == NULL, try reading the object named with "sha1" using
1153 * the streaming interface and rehash it to do the same.
1154 */
1155int check_sha1_signature(const unsigned char *sha1, void *map,
1156 unsigned long size, const char *type)
0fcfd160
LT
1157{
1158 unsigned char real_sha1[20];
090ea126
NTND
1159 enum object_type obj_type;
1160 struct git_istream *st;
1161 git_SHA_CTX c;
1162 char hdr[32];
1163 int hdrlen;
1164
1165 if (map) {
1166 hash_sha1_file(map, size, type, real_sha1);
1167 return hashcmp(sha1, real_sha1) ? -1 : 0;
1168 }
1169
1170 st = open_istream(sha1, &obj_type, &size, NULL);
1171 if (!st)
1172 return -1;
1173
1174 /* Generate the header */
1175 hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
1176
1177 /* Sha1.. */
1178 git_SHA1_Init(&c);
1179 git_SHA1_Update(&c, hdr, hdrlen);
1180 for (;;) {
1181 char buf[1024 * 16];
1182 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1183
1184 if (!readlen)
1185 break;
1186 git_SHA1_Update(&c, buf, readlen);
1187 }
1188 git_SHA1_Final(real_sha1, &c);
1189 close_istream(st);
a89fccd2 1190 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1191}
1192
f4e51683 1193static int git_open_noatime(const char *name)
44d1c19e
LT
1194{
1195 static int sha1_file_open_flag = O_NOATIME;
44d1c19e 1196
f2e872aa
SP
1197 for (;;) {
1198 int fd = open(name, O_RDONLY | sha1_file_open_flag);
44d1c19e 1199 if (fd >= 0)
f2e872aa
SP
1200 return fd;
1201
f2e872aa
SP
1202 /* Might the failure be due to O_NOATIME? */
1203 if (errno != ENOENT && sha1_file_open_flag) {
44d1c19e 1204 sha1_file_open_flag = 0;
f2e872aa
SP
1205 continue;
1206 }
1207
1208 return -1;
44d1c19e 1209 }
44d1c19e
LT
1210}
1211
1212static int open_sha1_file(const unsigned char *sha1)
1213{
1214 int fd;
1215 char *name = sha1_file_name(sha1);
1216 struct alternate_object_database *alt;
1217
f4e51683 1218 fd = git_open_noatime(name);
44d1c19e
LT
1219 if (fd >= 0)
1220 return fd;
1221
1222 prepare_alt_odb();
1223 errno = ENOENT;
1224 for (alt = alt_odb_list; alt; alt = alt->next) {
1225 name = alt->name;
1226 fill_sha1_path(name, sha1);
f4e51683 1227 fd = git_open_noatime(alt->base);
44d1c19e
LT
1228 if (fd >= 0)
1229 return fd;
1230 }
1231 return -1;
1232}
1233
f0270efd 1234void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1235{
0fcfd160 1236 void *map;
144bde78 1237 int fd;
ace1534d 1238
44d1c19e
LT
1239 fd = open_sha1_file(sha1);
1240 map = NULL;
1241 if (fd >= 0) {
1242 struct stat st;
0fcfd160 1243
44d1c19e
LT
1244 if (!fstat(fd, &st)) {
1245 *size = xsize_t(st.st_size);
33e42de0
MM
1246 if (!*size) {
1247 /* mmap() is forbidden on empty files */
1248 error("object file %s is empty", sha1_file_name(sha1));
1249 return NULL;
1250 }
44d1c19e 1251 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1252 }
44d1c19e 1253 close(fd);
0fcfd160 1254 }
0fcfd160
LT
1255 return map;
1256}
1257
cc5c54e7
JH
1258/*
1259 * There used to be a second loose object header format which
1260 * was meant to mimic the in-pack format, allowing for direct
1261 * copy of the object data. This format turned up not to be
1262 * really worth it and we no longer write loose objects in that
1263 * format.
1264 */
1265static int experimental_loose_object(unsigned char *map)
bb6b8e4f
JH
1266{
1267 unsigned int word;
1268
1269 /*
7f684a2a
RT
1270 * We must determine if the buffer contains the standard
1271 * zlib-deflated stream or the experimental format based
1272 * on the in-pack object format. Compare the header byte
1273 * for each format:
1274 *
1275 * RFC1950 zlib w/ deflate : 0www1000 : 0 <= www <= 7
1276 * Experimental pack-based : Stttssss : ttt = 1,2,3,4
1277 *
1278 * If bit 7 is clear and bits 0-3 equal 8, the buffer MUST be
1279 * in standard loose-object format, UNLESS it is a Git-pack
1280 * format object *exactly* 8 bytes in size when inflated.
1281 *
1282 * However, RFC1950 also specifies that the 1st 16-bit word
1283 * must be divisible by 31 - this checksum tells us our buffer
1284 * is in the standard format, giving a false positive only if
1285 * the 1st word of the Git-pack format object happens to be
1286 * divisible by 31, ie:
1287 * ((byte0 * 256) + byte1) % 31 = 0
1288 * => 0ttt10000www1000 % 31 = 0
1289 *
1290 * As it happens, this case can only arise for www=3 & ttt=1
1291 * - ie, a Commit object, which would have to be 8 bytes in
1292 * size. As no Commit can be that small, we find that the
1293 * combination of these two criteria (bitmask & checksum)
1294 * can always correctly determine the buffer format.
bb6b8e4f
JH
1295 */
1296 word = (map[0] << 8) + map[1];
7f684a2a 1297 if ((map[0] & 0x8F) == 0x08 && !(word % 31))
bb6b8e4f 1298 return 0;
cc5c54e7
JH
1299 else
1300 return 1;
bb6b8e4f
JH
1301}
1302
09ded04b
NP
1303unsigned long unpack_object_header_buffer(const unsigned char *buf,
1304 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1305{
ad1ed5ee 1306 unsigned shift;
48fb7deb 1307 unsigned long size, c;
ad1ed5ee
JH
1308 unsigned long used = 0;
1309
1310 c = buf[used++];
1311 *type = (c >> 4) & 7;
1312 size = c & 15;
1313 shift = 4;
1314 while (c & 0x80) {
f630cfda 1315 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1316 error("bad object header");
ea4f9685
JH
1317 size = used = 0;
1318 break;
09ded04b 1319 }
ad1ed5ee
JH
1320 c = buf[used++];
1321 size += (c & 0x7f) << shift;
1322 shift += 7;
1323 }
1324 *sizep = size;
1325 return used;
1326}
1327
eb4f4076 1328int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
ad1ed5ee
JH
1329{
1330 unsigned long size, used;
1331 static const char valid_loose_object_type[8] = {
1332 0, /* OBJ_EXT */
1333 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1334 0, /* "delta" and others are invalid in a loose object */
93821bd9 1335 };
ad1ed5ee 1336 enum object_type type;
93821bd9 1337
c4483576
LT
1338 /* Get the data stream */
1339 memset(stream, 0, sizeof(*stream));
1340 stream->next_in = map;
1341 stream->avail_in = mapsize;
1342 stream->next_out = buffer;
93821bd9
LT
1343 stream->avail_out = bufsiz;
1344
cc5c54e7
JH
1345 if (experimental_loose_object(map)) {
1346 /*
1347 * The old experimental format we no longer produce;
1348 * we can still read it.
1349 */
1350 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1351 if (!used || !valid_loose_object_type[type])
1352 return -1;
1353 map += used;
1354 mapsize -= used;
726f852b 1355
cc5c54e7
JH
1356 /* Set up the stream for the rest.. */
1357 stream->next_in = map;
1358 stream->avail_in = mapsize;
1359 git_inflate_init(stream);
93821bd9 1360
cc5c54e7
JH
1361 /* And generate the fake traditional header */
1362 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1363 typename(type), size);
1364 return 0;
1365 }
39c68542 1366 git_inflate_init(stream);
cc5c54e7 1367 return git_inflate(stream, 0);
c4483576
LT
1368}
1369
ef49a7a0 1370static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1371{
1372 int bytes = strlen(buffer) + 1;
3aee68aa 1373 unsigned char *buf = xmallocz(size);
93821bd9 1374 unsigned long n;
7efbff75 1375 int status = Z_OK;
5180cacc 1376
93821bd9
LT
1377 n = stream->total_out - bytes;
1378 if (n > size)
1379 n = size;
1380 memcpy(buf, (char *) buffer + bytes, n);
1381 bytes = n;
456cdf6e
LT
1382 if (bytes <= size) {
1383 /*
1384 * The above condition must be (bytes <= size), not
1385 * (bytes < size). In other words, even though we
ccf5ace0 1386 * expect no more output and set avail_out to zero,
456cdf6e
LT
1387 * the input zlib stream may have bytes that express
1388 * "this concludes the stream", and we *do* want to
1389 * eat that input.
1390 *
1391 * Otherwise we would not be able to test that we
1392 * consumed all the input to reach the expected size;
1393 * we also want to check that zlib tells us that all
1394 * went well with status == Z_STREAM_END at the end.
1395 */
5180cacc
LT
1396 stream->next_out = buf + bytes;
1397 stream->avail_out = size - bytes;
7efbff75 1398 while (status == Z_OK)
39c68542 1399 status = git_inflate(stream, Z_FINISH);
5180cacc 1400 }
456cdf6e 1401 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1402 git_inflate_end(stream);
7efbff75
JH
1403 return buf;
1404 }
1405
1406 if (status < 0)
1407 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1408 else if (stream->avail_in)
1409 error("garbage at end of loose object '%s'",
1410 sha1_to_hex(sha1));
1411 free(buf);
1412 return NULL;
5180cacc
LT
1413}
1414
1415/*
1416 * We used to just use "sscanf()", but that's actually way
1417 * too permissive for what we want to check. So do an anal
1418 * object header parse by hand.
1419 */
f0270efd 1420int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1421{
21666f1a 1422 char type[10];
5180cacc
LT
1423 int i;
1424 unsigned long size;
1425
1426 /*
a6080a0a 1427 * The type can be at most ten bytes (including the
5180cacc 1428 * terminating '\0' that we add), and is followed by
21666f1a 1429 * a space.
5180cacc 1430 */
21666f1a 1431 i = 0;
5180cacc
LT
1432 for (;;) {
1433 char c = *hdr++;
1434 if (c == ' ')
1435 break;
21666f1a
NP
1436 type[i++] = c;
1437 if (i >= sizeof(type))
5180cacc 1438 return -1;
5180cacc 1439 }
21666f1a 1440 type[i] = 0;
5180cacc
LT
1441
1442 /*
1443 * The length must follow immediately, and be in canonical
1444 * decimal format (ie "010" is not valid).
1445 */
1446 size = *hdr++ - '0';
1447 if (size > 9)
1448 return -1;
1449 if (size) {
1450 for (;;) {
1451 unsigned long c = *hdr - '0';
1452 if (c > 9)
1453 break;
1454 hdr++;
1455 size = size * 10 + c;
1456 }
1457 }
1458 *sizep = size;
1459
1460 /*
1461 * The length must be followed by a zero byte
1462 */
21666f1a 1463 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1464}
1465
7efbff75 1466static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1467{
5180cacc 1468 int ret;
ef49a7a0 1469 git_zstream stream;
5180cacc 1470 char hdr[8192];
0fcfd160 1471
5180cacc 1472 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1473 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1474 return NULL;
1475
7efbff75 1476 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1477}
1478
54dab52a
NP
1479unsigned long get_size_from_delta(struct packed_git *p,
1480 struct pack_window **w_curs,
1481 off_t curpos)
1482{
1483 const unsigned char *data;
1484 unsigned char delta_head[20], *in;
ef49a7a0 1485 git_zstream stream;
54dab52a
NP
1486 int st;
1487
1488 memset(&stream, 0, sizeof(stream));
1489 stream.next_out = delta_head;
1490 stream.avail_out = sizeof(delta_head);
1491
39c68542 1492 git_inflate_init(&stream);
54dab52a
NP
1493 do {
1494 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1495 stream.next_in = in;
39c68542 1496 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1497 curpos += stream.next_in - in;
1498 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1499 stream.total_out < sizeof(delta_head));
39c68542 1500 git_inflate_end(&stream);
3d77d877
NP
1501 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1502 error("delta data unpack-initial failed");
1503 return 0;
1504 }
54dab52a
NP
1505
1506 /* Examine the initial part of the delta to figure out
1507 * the result size.
1508 */
1509 data = delta_head;
1510
1511 /* ignore base size */
1512 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1513
1514 /* Read the result size */
1515 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1516}
1517
c4001d92 1518static off_t get_delta_base(struct packed_git *p,
03e79c88 1519 struct pack_window **w_curs,
c4001d92 1520 off_t *curpos,
21666f1a 1521 enum object_type type,
c4001d92 1522 off_t delta_obj_offset)
eb32d236 1523{
2b87c45b 1524 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1525 off_t base_offset;
eb32d236 1526
8d8a4ea5
SP
1527 /* use_pack() assured us we have [base_info, base_info + 20)
1528 * as a range that we can look at without walking off the
1529 * end of the mapped window. Its actually the hash size
1530 * that is assured. An OFS_DELTA longer than the hash size
1531 * is stupid, as then a REF_DELTA would be smaller to store.
1532 */
21666f1a 1533 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1534 unsigned used = 0;
1535 unsigned char c = base_info[used++];
1536 base_offset = c & 127;
1537 while (c & 128) {
1538 base_offset += 1;
8723f216 1539 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1540 return 0; /* overflow */
eb32d236
NP
1541 c = base_info[used++];
1542 base_offset = (base_offset << 7) + (c & 127);
1543 }
1544 base_offset = delta_obj_offset - base_offset;
d8f32556 1545 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 1546 return 0; /* out of bound */
2b87c45b 1547 *curpos += used;
21666f1a 1548 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1549 /* The base entry _must_ be in the same pack */
1550 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1551 *curpos += 20;
eb32d236
NP
1552 } else
1553 die("I am totally screwed");
2b87c45b 1554 return base_offset;
eb32d236
NP
1555}
1556
f3bf9224 1557/* forward declaration for a mutually recursive function */
c4001d92 1558static int packed_object_info(struct packed_git *p, off_t offset,
9a490590 1559 unsigned long *sizep, int *rtype);
f3bf9224 1560
43057304 1561static int packed_delta_info(struct packed_git *p,
03e79c88 1562 struct pack_window **w_curs,
c4001d92 1563 off_t curpos,
21666f1a 1564 enum object_type type,
c4001d92 1565 off_t obj_offset,
43057304 1566 unsigned long *sizep)
5db47c2b 1567{
c4001d92 1568 off_t base_offset;
f3bf9224 1569
21666f1a 1570 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
3d77d877
NP
1571 if (!base_offset)
1572 return OBJ_BAD;
9a490590 1573 type = packed_object_info(p, base_offset, NULL, NULL);
3d77d877 1574 if (type <= OBJ_NONE) {
08698b1e
NP
1575 struct revindex_entry *revidx;
1576 const unsigned char *base_sha1;
1577 revidx = find_pack_revindex(p, base_offset);
1578 if (!revidx)
1579 return OBJ_BAD;
1580 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
3d77d877
NP
1581 mark_bad_packed_object(p, base_sha1);
1582 type = sha1_object_info(base_sha1, NULL);
1583 if (type <= OBJ_NONE)
1584 return OBJ_BAD;
1585 }
f3bf9224 1586
c62266f3
JH
1587 /* We choose to only get the type of the base object and
1588 * ignore potentially corrupt pack file that expects the delta
1589 * based on a base with a wrong size. This saves tons of
1590 * inflate() calls.
1591 */
3d77d877 1592 if (sizep) {
54dab52a 1593 *sizep = get_size_from_delta(p, w_curs, curpos);
3d77d877
NP
1594 if (*sizep == 0)
1595 type = OBJ_BAD;
1596 }
21666f1a
NP
1597
1598 return type;
5db47c2b
JH
1599}
1600
f8c8abc5
JH
1601int unpack_object_header(struct packed_git *p,
1602 struct pack_window **w_curs,
1603 off_t *curpos,
1604 unsigned long *sizep)
a733cb60 1605{
03e79c88 1606 unsigned char *base;
ef49a7a0 1607 unsigned long left;
ad1ed5ee 1608 unsigned long used;
2b87c45b 1609 enum object_type type;
a733cb60 1610
8d8a4ea5 1611 /* use_pack() assures us we have [base, base + 20) available
0353a0c4 1612 * as a range that we can look at. (Its actually the hash
3dff5379 1613 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1614 * the maximum deflated object size is 2^137, which is just
1615 * insane, so we know won't exceed what we have been given.
1616 */
2b87c45b 1617 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
1618 used = unpack_object_header_buffer(base, left, &type, sizep);
1619 if (!used) {
1620 type = OBJ_BAD;
1621 } else
1622 *curpos += used;
ad1ed5ee 1623
2b87c45b 1624 return type;
a733cb60
LT
1625}
1626
c4001d92 1627static int packed_object_info(struct packed_git *p, off_t obj_offset,
9a490590 1628 unsigned long *sizep, int *rtype)
1f688557 1629{
03e79c88 1630 struct pack_window *w_curs = NULL;
c4001d92
SP
1631 unsigned long size;
1632 off_t curpos = obj_offset;
21666f1a 1633 enum object_type type;
5db47c2b 1634
21666f1a 1635 type = unpack_object_header(p, &w_curs, &curpos, &size);
9a490590
JH
1636 if (rtype)
1637 *rtype = type; /* representation type */
5db47c2b 1638
21666f1a 1639 switch (type) {
eb32d236
NP
1640 case OBJ_OFS_DELTA:
1641 case OBJ_REF_DELTA:
21666f1a
NP
1642 type = packed_delta_info(p, &w_curs, curpos,
1643 type, obj_offset, sizep);
2b87c45b 1644 break;
a733cb60 1645 case OBJ_COMMIT:
a733cb60 1646 case OBJ_TREE:
a733cb60 1647 case OBJ_BLOB:
a733cb60 1648 case OBJ_TAG:
2b87c45b
NP
1649 if (sizep)
1650 *sizep = size;
a69d0943 1651 break;
1f688557 1652 default:
3d77d877
NP
1653 error("unknown object type %i at offset %"PRIuMAX" in %s",
1654 type, (uintmax_t)obj_offset, p->pack_name);
1655 type = OBJ_BAD;
1f688557 1656 }
2b87c45b 1657 unuse_pack(&w_curs);
21666f1a 1658 return type;
1f688557
JH
1659}
1660
eb950c19 1661static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1662 struct pack_window **w_curs,
c4001d92 1663 off_t curpos,
eb950c19 1664 unsigned long size)
de530aaa
SP
1665{
1666 int st;
ef49a7a0 1667 git_zstream stream;
079afb18 1668 unsigned char *buffer, *in;
de530aaa 1669
4ab07e4d 1670 buffer = xmallocz(size);
de530aaa 1671 memset(&stream, 0, sizeof(stream));
de530aaa 1672 stream.next_out = buffer;
39eea7bd 1673 stream.avail_out = size + 1;
de530aaa 1674
39c68542 1675 git_inflate_init(&stream);
079afb18 1676 do {
2b87c45b 1677 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 1678 stream.next_in = in;
39c68542 1679 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
1680 if (!stream.avail_out)
1681 break; /* the payload is larger than it should be */
2b87c45b 1682 curpos += stream.next_in - in;
079afb18 1683 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 1684 git_inflate_end(&stream);
de530aaa
SP
1685 if ((st != Z_STREAM_END) || stream.total_out != size) {
1686 free(buffer);
1687 return NULL;
1688 }
1689
1690 return buffer;
1691}
1692
e5e01619
LT
1693#define MAX_DELTA_CACHE (256)
1694
18bdec11 1695static size_t delta_base_cached;
5e08ecbf
NP
1696
1697static struct delta_base_cache_lru_list {
1698 struct delta_base_cache_lru_list *prev;
1699 struct delta_base_cache_lru_list *next;
1700} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1701
e5e01619 1702static struct delta_base_cache_entry {
5e08ecbf
NP
1703 struct delta_base_cache_lru_list lru;
1704 void *data;
e5e01619
LT
1705 struct packed_git *p;
1706 off_t base_offset;
1707 unsigned long size;
e5e01619
LT
1708 enum object_type type;
1709} delta_base_cache[MAX_DELTA_CACHE];
1710
1711static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1712{
1713 unsigned long hash;
1714
1715 hash = (unsigned long)p + (unsigned long)base_offset;
1716 hash += (hash >> 8) + (hash >> 16);
3358004a 1717 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1718}
1719
5266d369
JH
1720static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1721{
1722 unsigned long hash = pack_entry_hash(p, base_offset);
1723 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1724 return (ent->data && ent->p == p && ent->base_offset == base_offset);
1725}
1726
62f255ad 1727static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1728 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1729{
e5e01619
LT
1730 void *ret;
1731 unsigned long hash = pack_entry_hash(p, base_offset);
1732 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1733
1734 ret = ent->data;
749bc58c
MV
1735 if (!ret || ent->p != p || ent->base_offset != base_offset)
1736 return unpack_entry(p, base_offset, type, base_size);
e5e01619 1737
18bdec11 1738 if (!keep_cache) {
a0cba108 1739 ent->data = NULL;
5e08ecbf
NP
1740 ent->lru.next->prev = ent->lru.prev;
1741 ent->lru.prev->next = ent->lru.next;
18bdec11 1742 delta_base_cached -= ent->size;
182af834
PH
1743 } else {
1744 ret = xmemdupz(ent->data, ent->size);
a0cba108 1745 }
e5e01619
LT
1746 *type = ent->type;
1747 *base_size = ent->size;
1748 return ret;
62f255ad
LT
1749}
1750
18bdec11
SP
1751static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1752{
1753 if (ent->data) {
1754 free(ent->data);
1755 ent->data = NULL;
5e08ecbf
NP
1756 ent->lru.next->prev = ent->lru.prev;
1757 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1758 delta_base_cached -= ent->size;
1759 }
1760}
1761
3d20c636
SP
1762void clear_delta_base_cache(void)
1763{
1764 unsigned long p;
1765 for (p = 0; p < MAX_DELTA_CACHE; p++)
1766 release_delta_base_cache(&delta_base_cache[p]);
1767}
1768
62f255ad
LT
1769static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1770 void *base, unsigned long base_size, enum object_type type)
1771{
5e08ecbf 1772 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1773 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1774 struct delta_base_cache_lru_list *lru;
e5e01619 1775
18bdec11
SP
1776 release_delta_base_cache(ent);
1777 delta_base_cached += base_size;
5e08ecbf
NP
1778
1779 for (lru = delta_base_cache_lru.next;
1780 delta_base_cached > delta_base_cache_limit
1781 && lru != &delta_base_cache_lru;
1782 lru = lru->next) {
1783 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1784 if (f->type == OBJ_BLOB)
1785 release_delta_base_cache(f);
1786 }
5e08ecbf
NP
1787 for (lru = delta_base_cache_lru.next;
1788 delta_base_cached > delta_base_cache_limit
1789 && lru != &delta_base_cache_lru;
1790 lru = lru->next) {
1791 struct delta_base_cache_entry *f = (void *)lru;
1792 release_delta_base_cache(f);
1793 }
18bdec11 1794
e5e01619
LT
1795 ent->p = p;
1796 ent->base_offset = base_offset;
1797 ent->type = type;
1798 ent->data = base;
1799 ent->size = base_size;
5e08ecbf
NP
1800 ent->lru.next = &delta_base_cache_lru;
1801 ent->lru.prev = delta_base_cache_lru.prev;
1802 delta_base_cache_lru.prev->next = &ent->lru;
1803 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1804}
1805
c2c5b270
CC
1806static void *read_object(const unsigned char *sha1, enum object_type *type,
1807 unsigned long *size);
1808
eb950c19 1809static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1810 struct pack_window **w_curs,
c4001d92 1811 off_t curpos,
1f688557 1812 unsigned long delta_size,
c4001d92 1813 off_t obj_offset,
21666f1a 1814 enum object_type *type,
eb950c19 1815 unsigned long *sizep)
1f688557 1816{
7c3e8be3 1817 void *delta_data, *result, *base;
c4001d92
SP
1818 unsigned long base_size;
1819 off_t base_offset;
43057304 1820
21666f1a 1821 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
8eca0b47
NP
1822 if (!base_offset) {
1823 error("failed to validate delta base reference "
1824 "at offset %"PRIuMAX" from %s",
1825 (uintmax_t)curpos, p->pack_name);
1826 return NULL;
1827 }
eac12e2d 1828 unuse_pack(w_curs);
a0cba108 1829 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
8eca0b47
NP
1830 if (!base) {
1831 /*
1832 * We're probably in deep shit, but let's try to fetch
1833 * the required base anyway from another pack or loose.
1834 * This is costly but should happen only in the presence
1835 * of a corrupted pack, and is better than failing outright.
1836 */
08698b1e
NP
1837 struct revindex_entry *revidx;
1838 const unsigned char *base_sha1;
1839 revidx = find_pack_revindex(p, base_offset);
1840 if (!revidx)
1841 return NULL;
1842 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
8eca0b47
NP
1843 error("failed to read delta base object %s"
1844 " at offset %"PRIuMAX" from %s",
1845 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1846 p->pack_name);
1847 mark_bad_packed_object(p, base_sha1);
ac939109 1848 base = read_object(base_sha1, type, &base_size);
8eca0b47
NP
1849 if (!base)
1850 return NULL;
1851 }
67686d95 1852
2b87c45b 1853 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
8eca0b47
NP
1854 if (!delta_data) {
1855 error("failed to unpack compressed delta "
1856 "at offset %"PRIuMAX" from %s",
1857 (uintmax_t)curpos, p->pack_name);
1858 free(base);
1859 return NULL;
1860 }
1f688557
JH
1861 result = patch_delta(base, base_size,
1862 delta_data, delta_size,
21666f1a 1863 sizep);
1f688557
JH
1864 if (!result)
1865 die("failed to apply delta");
1866 free(delta_data);
62f255ad 1867 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1868 return result;
1869}
1870
5f44324d
JH
1871static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1872{
1873 static FILE *log_file;
1874
1875 if (!log_file) {
1876 log_file = fopen(log_pack_access, "w");
1877 if (!log_file) {
1878 error("cannot open pack access log '%s' for writing: %s",
1879 log_pack_access, strerror(errno));
1880 log_pack_access = NULL;
1881 return;
1882 }
1883 }
1884 fprintf(log_file, "%s %"PRIuMAX"\n",
1885 p->pack_name, (uintmax_t)obj_offset);
1886 fflush(log_file);
1887}
1888
0e8189e2
NP
1889int do_check_packed_object_crc;
1890
c4001d92 1891void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1892 enum object_type *type, unsigned long *sizep)
1f688557 1893{
03e79c88 1894 struct pack_window *w_curs = NULL;
c4001d92 1895 off_t curpos = obj_offset;
21666f1a 1896 void *data;
1f688557 1897
5f44324d
JH
1898 if (log_pack_access)
1899 write_pack_access_log(p, obj_offset);
1900
0e8189e2
NP
1901 if (do_check_packed_object_crc && p->index_version > 1) {
1902 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1903 unsigned long len = revidx[1].offset - obj_offset;
1904 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1905 const unsigned char *sha1 =
1906 nth_packed_object_sha1(p, revidx->nr);
1907 error("bad packed object CRC for %s",
1908 sha1_to_hex(sha1));
1909 mark_bad_packed_object(p, sha1);
f755bb99 1910 unuse_pack(&w_curs);
0e8189e2
NP
1911 return NULL;
1912 }
1913 }
1914
21666f1a
NP
1915 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1916 switch (*type) {
eb32d236
NP
1917 case OBJ_OFS_DELTA:
1918 case OBJ_REF_DELTA:
21666f1a
NP
1919 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1920 obj_offset, type, sizep);
4d703a1a 1921 break;
a733cb60 1922 case OBJ_COMMIT:
a733cb60 1923 case OBJ_TREE:
a733cb60 1924 case OBJ_BLOB:
a733cb60 1925 case OBJ_TAG:
21666f1a 1926 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1927 break;
1f688557 1928 default:
8eca0b47
NP
1929 data = NULL;
1930 error("unknown object type %i at offset %"PRIuMAX" in %s",
1931 *type, (uintmax_t)obj_offset, p->pack_name);
1f688557 1932 }
03e79c88 1933 unuse_pack(&w_curs);
21666f1a 1934 return data;
1f688557
JH
1935}
1936
d079837e 1937const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1938 uint32_t n)
9a217f2a 1939{
42873078 1940 const unsigned char *index = p->index_data;
d079837e
SP
1941 if (!index) {
1942 if (open_pack_index(p))
1943 return NULL;
1944 index = p->index_data;
1945 }
57059091 1946 if (n >= p->num_objects)
d72308e0 1947 return NULL;
74e34e1f
NP
1948 index += 4 * 256;
1949 if (p->index_version == 1) {
1950 return index + 24 * n + 4;
1951 } else {
1952 index += 8;
1953 return index + 20 * n;
1954 }
1955}
1956
99093238 1957off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
1958{
1959 const unsigned char *index = p->index_data;
1960 index += 4 * 256;
1961 if (p->index_version == 1) {
1962 return ntohl(*((uint32_t *)(index + 24 * n)));
1963 } else {
1964 uint32_t off;
1965 index += 8 + p->num_objects * (20 + 4);
1966 off = ntohl(*((uint32_t *)(index + 4 * n)));
1967 if (!(off & 0x80000000))
1968 return off;
1969 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1970 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1971 ntohl(*((uint32_t *)(index + 4)));
1972 }
9a217f2a
JH
1973}
1974
c4001d92 1975off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1976 struct packed_git *p)
1f688557 1977{
42873078 1978 const uint32_t *level1_ofs = p->index_data;
42873078 1979 const unsigned char *index = p->index_data;
628522ec
JH
1980 unsigned hi, lo, stride;
1981 static int use_lookup = -1;
1982 static int debug_lookup = -1;
1983
1984 if (debug_lookup < 0)
1985 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1986
d079837e
SP
1987 if (!index) {
1988 if (open_pack_index(p))
1989 return 0;
1990 level1_ofs = p->index_data;
1991 index = p->index_data;
1992 }
74e34e1f
NP
1993 if (p->index_version > 1) {
1994 level1_ofs += 2;
1995 index += 8;
1996 }
42873078 1997 index += 4 * 256;
74e34e1f
NP
1998 hi = ntohl(level1_ofs[*sha1]);
1999 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
2000 if (p->index_version > 1) {
2001 stride = 20;
2002 } else {
2003 stride = 24;
2004 index += 4;
2005 }
2006
2007 if (debug_lookup)
6e1c2344 2008 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
2009 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2010
2011 if (use_lookup < 0)
2012 use_lookup = !!getenv("GIT_USE_LOOKUP");
2013 if (use_lookup) {
2014 int pos = sha1_entry_pos(index, stride, 0,
2015 lo, hi, p->num_objects, sha1);
2016 if (pos < 0)
2017 return 0;
2018 return nth_packed_object_offset(p, pos);
2019 }
1f688557
JH
2020
2021 do {
74e34e1f 2022 unsigned mi = (lo + hi) / 2;
628522ec
JH
2023 int cmp = hashcmp(index + mi * stride, sha1);
2024
2025 if (debug_lookup)
2026 printf("lo %u hi %u rg %u mi %u\n",
2027 lo, hi, hi - lo, mi);
43057304 2028 if (!cmp)
74e34e1f 2029 return nth_packed_object_offset(p, mi);
1f688557
JH
2030 if (cmp > 0)
2031 hi = mi;
2032 else
2033 lo = mi+1;
2034 } while (lo < hi);
2035 return 0;
2036}
2037
4c080182 2038int is_pack_valid(struct packed_git *p)
d131b7af
SP
2039{
2040 /* An already open pack is known to be valid. */
2041 if (p->pack_fd != -1)
2042 return 1;
2043
2044 /* If the pack has one window completely covering the
2045 * file size, the pack is known to be valid even if
2046 * the descriptor is not currently open.
2047 */
2048 if (p->windows) {
2049 struct pack_window *w = p->windows;
2050
2051 if (!w->offset && w->len == p->pack_size)
2052 return 1;
2053 }
2054
2055 /* Force the pack to open to prove its valid. */
2056 return !open_packed_git(p);
2057}
2058
95099731
NTND
2059static int fill_pack_entry(const unsigned char *sha1,
2060 struct pack_entry *e,
2061 struct packed_git *p)
2062{
2063 off_t offset;
2064
2065 if (p->num_bad_objects) {
2066 unsigned i;
2067 for (i = 0; i < p->num_bad_objects; i++)
2068 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2069 return 0;
2070 }
2071
2072 offset = find_pack_entry_one(sha1, p);
2073 if (!offset)
2074 return 0;
2075
2076 /*
2077 * We are about to tell the caller where they can locate the
2078 * requested object. We better make sure the packfile is
2079 * still here and can be accessed before supplying that
2080 * answer, as it may have been deleted since the index was
2081 * loaded!
2082 */
2083 if (!is_pack_valid(p)) {
2084 warning("packfile %s cannot be accessed", p->pack_name);
2085 return 0;
2086 }
2087 e->offset = offset;
2088 e->p = p;
2089 hashcpy(e->sha1, sha1);
2090 return 1;
2091}
2092
4d6acb70 2093static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557
JH
2094{
2095 struct packed_git *p;
43057304 2096
1f688557 2097 prepare_packed_git();
f7c22cc6
NP
2098 if (!packed_git)
2099 return 0;
1f688557 2100
c01f51cc
NTND
2101 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2102 return 1;
8eca0b47 2103
c01f51cc
NTND
2104 for (p = packed_git; p; p = p->next) {
2105 if (p == last_found_pack || !fill_pack_entry(sha1, e, p))
2106 continue;
f7c22cc6 2107
c01f51cc
NTND
2108 last_found_pack = p;
2109 return 1;
2110 }
1f688557
JH
2111 return 0;
2112}
2113
a6080a0a 2114struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
2115 struct packed_git *packs)
2116{
2117 struct packed_git *p;
bf592c50
DB
2118
2119 for (p = packs; p; p = p->next) {
43057304 2120 if (find_pack_entry_one(sha1, p))
bf592c50
DB
2121 return p;
2122 }
2123 return NULL;
21666f1a 2124
bf592c50
DB
2125}
2126
21666f1a 2127static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 2128{
36e4d74a 2129 int status;
65c2e0c3
JH
2130 unsigned long mapsize, size;
2131 void *map;
ef49a7a0 2132 git_zstream stream;
d65a16f6 2133 char hdr[32];
65c2e0c3 2134
bb6b8e4f 2135 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
2136 if (!map)
2137 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
2138 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2139 status = error("unable to unpack %s header",
2140 sha1_to_hex(sha1));
21666f1a 2141 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 2142 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
2143 else if (sizep)
2144 *sizep = size;
39c68542 2145 git_inflate_end(&stream);
65c2e0c3
JH
2146 munmap(map, mapsize);
2147 return status;
2148}
2149
9a490590
JH
2150/* returns enum object_type or negative */
2151int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
f0df4ed5 2152{
c4d9986f 2153 struct cached_object *co;
f0df4ed5 2154 struct pack_entry e;
9a490590 2155 int status, rtype;
f0df4ed5 2156
c4d9986f
NTND
2157 co = find_cached_object(sha1);
2158 if (co) {
9a490590
JH
2159 if (oi->sizep)
2160 *(oi->sizep) = co->size;
2161 oi->whence = OI_CACHED;
c4d9986f
NTND
2162 return co->type;
2163 }
2164
cd673c1f 2165 if (!find_pack_entry(sha1, &e)) {
ddd63e64 2166 /* Most likely it's a loose object. */
9a490590
JH
2167 status = sha1_loose_object_info(sha1, oi->sizep);
2168 if (status >= 0) {
2169 oi->whence = OI_LOOSE;
ddd63e64 2170 return status;
9a490590 2171 }
ddd63e64
SG
2172
2173 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 2174 reprepare_packed_git();
cd673c1f 2175 if (!find_pack_entry(sha1, &e))
ddd63e64 2176 return status;
f0df4ed5 2177 }
3d77d877 2178
9a490590 2179 status = packed_object_info(e.p, e.offset, oi->sizep, &rtype);
3d77d877
NP
2180 if (status < 0) {
2181 mark_bad_packed_object(e.p, sha1);
9a490590 2182 status = sha1_object_info_extended(sha1, oi);
5266d369
JH
2183 } else if (in_delta_base_cache(e.p, e.offset)) {
2184 oi->whence = OI_DBCACHED;
9a490590
JH
2185 } else {
2186 oi->whence = OI_PACKED;
2187 oi->u.packed.offset = e.offset;
2188 oi->u.packed.pack = e.p;
2189 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2190 rtype == OBJ_OFS_DELTA);
3d77d877
NP
2191 }
2192
2193 return status;
f0df4ed5
JS
2194}
2195
9a490590
JH
2196int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2197{
2198 struct object_info oi;
2199
2200 oi.sizep = sizep;
2201 return sha1_object_info_extended(sha1, &oi);
2202}
2203
21666f1a
NP
2204static void *read_packed_sha1(const unsigned char *sha1,
2205 enum object_type *type, unsigned long *size)
1f688557
JH
2206{
2207 struct pack_entry e;
8eca0b47 2208 void *data;
1f688557 2209
cd673c1f 2210 if (!find_pack_entry(sha1, &e))
1f688557 2211 return NULL;
8eca0b47
NP
2212 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2213 if (!data) {
2214 /*
2215 * We're probably in deep shit, but let's try to fetch
2216 * the required object anyway from another pack or loose.
2217 * This should happen only in the presence of a corrupted
2218 * pack, and is better than failing outright.
2219 */
2220 error("failed to read object %s at offset %"PRIuMAX" from %s",
2221 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2222 mark_bad_packed_object(e.p, sha1);
ac939109 2223 data = read_object(sha1, type, size);
8eca0b47
NP
2224 }
2225 return data;
1f688557
JH
2226}
2227
21666f1a
NP
2228int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2229 unsigned char *sha1)
d66b37bb
JH
2230{
2231 struct cached_object *co;
2232
21666f1a 2233 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2234 if (has_sha1_file(sha1) || find_cached_object(sha1))
2235 return 0;
2236 if (cached_object_alloc <= cached_object_nr) {
2237 cached_object_alloc = alloc_nr(cached_object_alloc);
2238 cached_objects = xrealloc(cached_objects,
2239 sizeof(*cached_objects) *
2240 cached_object_alloc);
2241 }
2242 co = &cached_objects[cached_object_nr++];
2243 co->size = len;
21666f1a 2244 co->type = type;
efa13f7b
JH
2245 co->buf = xmalloc(len);
2246 memcpy(co->buf, buf, len);
d66b37bb
JH
2247 hashcpy(co->sha1, sha1);
2248 return 0;
2249}
2250
c2c5b270
CC
2251static void *read_object(const unsigned char *sha1, enum object_type *type,
2252 unsigned long *size)
0fcfd160
LT
2253{
2254 unsigned long mapsize;
2255 void *map, *buf;
d66b37bb
JH
2256 struct cached_object *co;
2257
2258 co = find_cached_object(sha1);
2259 if (co) {
21666f1a 2260 *type = co->type;
d66b37bb 2261 *size = co->size;
182af834 2262 return xmemdupz(co->buf, co->size);
d66b37bb 2263 }
0fcfd160 2264
8276c007
PE
2265 buf = read_packed_sha1(sha1, type, size);
2266 if (buf)
2267 return buf;
bb6b8e4f 2268 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2269 if (map) {
7efbff75 2270 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2271 munmap(map, mapsize);
2272 return buf;
2273 }
637cdd9d 2274 reprepare_packed_git();
8276c007 2275 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2276}
2277
b6c4cecc
JH
2278/*
2279 * This function dies on corrupt objects; the callers who want to
2280 * deal with them should arrange to call read_object() and give error
2281 * messages themselves.
2282 */
5bf29b95
JH
2283void *read_sha1_file_extended(const unsigned char *sha1,
2284 enum object_type *type,
2285 unsigned long *size,
2286 unsigned flag)
ac939109 2287{
3ba7a065 2288 void *data;
e8b15e61 2289 char *path;
b6c4cecc 2290 const struct packed_git *p;
5bf29b95
JH
2291 const unsigned char *repl = (flag & READ_SHA1_FILE_REPLACE)
2292 ? lookup_replace_object(sha1) : sha1;
b6c4cecc 2293
3ba7a065
JH
2294 errno = 0;
2295 data = read_object(repl, type, size);
4bbf5a26 2296 if (data)
b6c4cecc 2297 return data;
68095570 2298
25f3af3f 2299 if (errno && errno != ENOENT)
3ba7a065
JH
2300 die_errno("failed to read object %s", sha1_to_hex(sha1));
2301
68095570 2302 /* die if we replaced an object with one that does not exist */
b6c4cecc 2303 if (repl != sha1)
68095570
CC
2304 die("replacement %s not found for %s",
2305 sha1_to_hex(repl), sha1_to_hex(sha1));
2306
b6c4cecc
JH
2307 if (has_loose_object(repl)) {
2308 path = sha1_file_name(sha1);
2309 die("loose object %s (stored in %s) is corrupt",
2310 sha1_to_hex(repl), path);
e8b15e61 2311 }
68095570 2312
b6c4cecc
JH
2313 if ((p = has_packed_and_bad(repl)) != NULL)
2314 die("packed object %s (stored in %s) is corrupt",
2315 sha1_to_hex(repl), p->pack_name);
f5552aee 2316
b6c4cecc 2317 return NULL;
ac939109
NP
2318}
2319
40469ee9 2320void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2321 const char *required_type_name,
40469ee9
JH
2322 unsigned long *size,
2323 unsigned char *actual_sha1_return)
f4913f91 2324{
21666f1a 2325 enum object_type type, required_type;
f4913f91
JH
2326 void *buffer;
2327 unsigned long isize;
40469ee9 2328 unsigned char actual_sha1[20];
f4913f91 2329
21666f1a 2330 required_type = type_from_string(required_type_name);
e702496e 2331 hashcpy(actual_sha1, sha1);
40469ee9
JH
2332 while (1) {
2333 int ref_length = -1;
2334 const char *ref_type = NULL;
f4913f91 2335
21666f1a 2336 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2337 if (!buffer)
2338 return NULL;
21666f1a 2339 if (type == required_type) {
40469ee9
JH
2340 *size = isize;
2341 if (actual_sha1_return)
e702496e 2342 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2343 return buffer;
2344 }
2345 /* Handle references */
21666f1a 2346 else if (type == OBJ_COMMIT)
40469ee9 2347 ref_type = "tree ";
21666f1a 2348 else if (type == OBJ_TAG)
40469ee9
JH
2349 ref_type = "object ";
2350 else {
2351 free(buffer);
2352 return NULL;
2353 }
2354 ref_length = strlen(ref_type);
f4913f91 2355
50974ec9
MK
2356 if (ref_length + 40 > isize ||
2357 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2358 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2359 free(buffer);
2360 return NULL;
2361 }
1cf58e72 2362 free(buffer);
40469ee9
JH
2363 /* Now we have the ID of the referred-to object in
2364 * actual_sha1. Check again. */
f4913f91 2365 }
f4913f91
JH
2366}
2367
ce9fbf16 2368static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2369 const char *type, unsigned char *sha1,
d65a16f6 2370 char *hdr, int *hdrlen)
d410c0f5 2371{
9126f009 2372 git_SHA_CTX c;
d410c0f5
JH
2373
2374 /* Generate the header */
d65a16f6 2375 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2376
2377 /* Sha1.. */
9126f009
NP
2378 git_SHA1_Init(&c);
2379 git_SHA1_Update(&c, hdr, *hdrlen);
2380 git_SHA1_Update(&c, buf, len);
2381 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2382}
2383
230f1322 2384/*
5a688fe4
JH
2385 * Move the just written object into its final resting place.
2386 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2387 * "moving" is only a part of what it does, when no patch between
2388 * master to pu changes the call sites of this function.
230f1322 2389 */
839837b9 2390int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2391{
e32c0a9c 2392 int ret = 0;
5a688fe4 2393
348df166 2394 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
2395 goto try_rename;
2396 else if (link(tmpfile, filename))
e32c0a9c 2397 ret = errno;
7ebb6fca
LT
2398
2399 /*
2400 * Coda hack - coda doesn't like cross-directory links,
2401 * so we fall back to a rename, which will mean that it
2402 * won't be able to check collisions, but that's not a
2403 * big deal.
2404 *
2405 * The same holds for FAT formatted media.
2406 *
3be1f18e 2407 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
2408 * left to unlink.
2409 */
2410 if (ret && ret != EEXIST) {
be66a6c4 2411 try_rename:
7ebb6fca 2412 if (!rename(tmpfile, filename))
3be1f18e 2413 goto out;
9e48b389 2414 ret = errno;
230f1322 2415 }
691f1a28 2416 unlink_or_warn(tmpfile);
230f1322
LT
2417 if (ret) {
2418 if (ret != EEXIST) {
82247e9b 2419 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
230f1322
LT
2420 }
2421 /* FIXME!!! Collision check here ? */
2422 }
2423
3be1f18e 2424out:
5256b006 2425 if (adjust_shared_perm(filename))
5a688fe4 2426 return error("unable to set permission to '%s'", filename);
230f1322
LT
2427 return 0;
2428}
2429
4d548150
LT
2430static int write_buffer(int fd, const void *buf, size_t len)
2431{
d34cf19b 2432 if (write_in_full(fd, buf, len) < 0)
93822c22 2433 return error("file write error (%s)", strerror(errno));
4d548150
LT
2434 return 0;
2435}
2436
ce9fbf16 2437int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2438 unsigned char *sha1)
2439{
d65a16f6 2440 char hdr[32];
abdc3fc8
RS
2441 int hdrlen;
2442 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2443 return 0;
2444}
2445
e9039dd3
LT
2446/* Finalize a file on disk, and close it. */
2447static void close_sha1_file(int fd)
2448{
aafe9fba
LT
2449 if (fsync_object_files)
2450 fsync_or_die(fd, "sha1 file");
e9039dd3 2451 if (close(fd) != 0)
d824cbba 2452 die_errno("error when closing sha1 file");
e9039dd3
LT
2453}
2454
5723fe7e
LT
2455/* Size of directory component, including the ending '/' */
2456static inline int directory_size(const char *filename)
2457{
2458 const char *s = strrchr(filename, '/');
2459 if (!s)
2460 return 0;
2461 return s - filename + 1;
2462}
2463
2464/*
2465 * This creates a temporary file in the same directory as the final
2466 * 'filename'
2467 *
2468 * We want to avoid cross-directory filename renames, because those
2469 * can have problems on various filesystems (FAT, NFS, Coda).
2470 */
2471static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2472{
2473 int fd, dirlen = directory_size(filename);
2474
2475 if (dirlen + 20 > bufsiz) {
2476 errno = ENAMETOOLONG;
2477 return -1;
2478 }
2479 memcpy(buffer, filename, dirlen);
2480 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
5256b006 2481 fd = git_mkstemp_mode(buffer, 0444);
cbacbf4e 2482 if (fd < 0 && dirlen && errno == ENOENT) {
5723fe7e 2483 /* Make sure the directory exists */
6ff6af62 2484 memcpy(buffer, filename, dirlen);
5723fe7e 2485 buffer[dirlen-1] = 0;
3bfaf018 2486 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2487 return -1;
2488
2489 /* Try again */
2490 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
5256b006 2491 fd = git_mkstemp_mode(buffer, 0444);
5723fe7e
LT
2492 }
2493 return fd;
2494}
2495
bbac7311 2496static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
c00e657d 2497 const void *buf, unsigned long len, time_t mtime)
0fcfd160 2498{
915308b1 2499 int fd, ret;
9892beba 2500 unsigned char compressed[4096];
ef49a7a0 2501 git_zstream stream;
748af44c
NP
2502 git_SHA_CTX c;
2503 unsigned char parano_sha1[20];
706bc531 2504 char *filename;
ab1900a3 2505 static char tmp_file[PATH_MAX];
a44c9a5e 2506
972a9155 2507 filename = sha1_file_name(sha1);
ab1900a3 2508 fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
aac17941 2509 if (fd < 0) {
35243577 2510 if (errno == EACCES)
82247e9b 2511 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
916d081b 2512 else
5eaeda70 2513 return error("unable to create temporary file: %s", strerror(errno));
aac17941
LT
2514 }
2515
0fcfd160
LT
2516 /* Set it up */
2517 memset(&stream, 0, sizeof(stream));
55bb5c91 2518 git_deflate_init(&stream, zlib_compression_level);
0fcfd160 2519 stream.next_out = compressed;
9892beba 2520 stream.avail_out = sizeof(compressed);
748af44c 2521 git_SHA1_Init(&c);
a44c9a5e
LT
2522
2523 /* First header.. */
d65a16f6 2524 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2525 stream.avail_in = hdrlen;
55bb5c91
JH
2526 while (git_deflate(&stream, 0) == Z_OK)
2527 ; /* nothing */
748af44c 2528 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
2529
2530 /* Then the data itself.. */
c00e657d 2531 stream.next_in = (void *)buf;
a44c9a5e 2532 stream.avail_in = len;
9892beba 2533 do {
748af44c 2534 unsigned char *in0 = stream.next_in;
55bb5c91 2535 ret = git_deflate(&stream, Z_FINISH);
748af44c 2536 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
2537 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2538 die("unable to write sha1 file");
2539 stream.next_out = compressed;
2540 stream.avail_out = sizeof(compressed);
2541 } while (ret == Z_OK);
2542
ac54c277
LT
2543 if (ret != Z_STREAM_END)
2544 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
55bb5c91 2545 ret = git_deflate_end_gently(&stream);
ac54c277
LT
2546 if (ret != Z_OK)
2547 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
2548 git_SHA1_Final(parano_sha1, &c);
2549 if (hashcmp(sha1, parano_sha1) != 0)
2550 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 2551
e9039dd3 2552 close_sha1_file(fd);
0fcfd160 2553
bbac7311
NP
2554 if (mtime) {
2555 struct utimbuf utb;
2556 utb.actime = mtime;
2557 utb.modtime = mtime;
ab1900a3 2558 if (utime(tmp_file, &utb) < 0)
bbac7311 2559 warning("failed utime() on %s: %s",
ab1900a3 2560 tmp_file, strerror(errno));
bbac7311
NP
2561 }
2562
ab1900a3 2563 return move_temp_to_file(tmp_file, filename);
0fcfd160 2564}
8237b185 2565
c00e657d 2566int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
bbac7311
NP
2567{
2568 unsigned char sha1[20];
2569 char hdr[32];
2570 int hdrlen;
2571
2572 /* Normally if we have it in the pack then we do not bother writing
2573 * it out into .git/objects/??/?{38} file.
2574 */
2575 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2576 if (returnsha1)
2577 hashcpy(returnsha1, sha1);
2578 if (has_sha1_file(sha1))
2579 return 0;
2580 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2581}
2582
2583int force_object_loose(const unsigned char *sha1, time_t mtime)
2584{
bbac7311
NP
2585 void *buf;
2586 unsigned long len;
2587 enum object_type type;
2588 char hdr[32];
2589 int hdrlen;
1fb23e65 2590 int ret;
bbac7311 2591
c529d75a 2592 if (has_loose_object(sha1))
bbac7311
NP
2593 return 0;
2594 buf = read_packed_sha1(sha1, &type, &len);
2595 if (!buf)
2596 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2597 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1fb23e65
BS
2598 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2599 free(buf);
2600
2601 return ret;
bbac7311
NP
2602}
2603
bf592c50
DB
2604int has_pack_index(const unsigned char *sha1)
2605{
2606 struct stat st;
2607 if (stat(sha1_pack_index_name(sha1), &st))
2608 return 0;
2609 return 1;
bf592c50
DB
2610}
2611
cd673c1f
JH
2612int has_sha1_pack(const unsigned char *sha1)
2613{
2614 struct pack_entry e;
2615 return find_pack_entry(sha1, &e);
2616}
2617
8237b185
DB
2618int has_sha1_file(const unsigned char *sha1)
2619{
1f688557
JH
2620 struct pack_entry e;
2621
cd673c1f 2622 if (find_pack_entry(sha1, &e))
1f688557 2623 return 1;
c529d75a 2624 return has_loose_object(sha1);
8237b185 2625}
74400e71 2626
c879daa2
NTND
2627static void check_tree(const void *buf, size_t size)
2628{
2629 struct tree_desc desc;
2630 struct name_entry entry;
2631
2632 init_tree_desc(&desc, buf, size);
2633 while (tree_entry(&desc, &entry))
2634 /* do nothing
2635 * tree_entry() will die() on malformed entries */
2636 ;
2637}
2638
2639static void check_commit(const void *buf, size_t size)
2640{
2641 struct commit c;
2642 memset(&c, 0, sizeof(c));
2643 if (parse_commit_buffer(&c, buf, size))
2644 die("corrupt commit");
2645}
2646
2647static void check_tag(const void *buf, size_t size)
2648{
2649 struct tag t;
2650 memset(&t, 0, sizeof(t));
2651 if (parse_tag_buffer(&t, buf, size))
2652 die("corrupt tag");
2653}
2654
43df4f86 2655static int index_mem(unsigned char *sha1, void *buf, size_t size,
c4ce46fc
JH
2656 enum object_type type,
2657 const char *path, unsigned flags)
e7332f96 2658{
6c510bee 2659 int ret, re_allocated = 0;
c4ce46fc 2660 int write_object = flags & HASH_WRITE_OBJECT;
74400e71 2661
7672db20 2662 if (!type)
edaec3fb 2663 type = OBJ_BLOB;
6c510bee
LT
2664
2665 /*
2666 * Convert blobs to git internal format
2667 */
43df4f86 2668 if ((type == OBJ_BLOB) && path) {
f285a2d7 2669 struct strbuf nbuf = STRBUF_INIT;
21e5ad50 2670 if (convert_to_git(path, buf, size, &nbuf,
5e12e78e 2671 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
b315c5c0 2672 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2673 re_allocated = 1;
2674 }
2675 }
c4ce46fc 2676 if (flags & HASH_FORMAT_CHECK) {
c879daa2
NTND
2677 if (type == OBJ_TREE)
2678 check_tree(buf, size);
2679 if (type == OBJ_COMMIT)
2680 check_commit(buf, size);
2681 if (type == OBJ_TAG)
2682 check_tag(buf, size);
2683 }
6c510bee 2684
7672db20 2685 if (write_object)
edaec3fb 2686 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2687 else
edaec3fb 2688 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 2689 if (re_allocated)
6c510bee 2690 free(buf);
43df4f86
DP
2691 return ret;
2692}
2693
7b41e1e1
JH
2694static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
2695 const char *path, unsigned flags)
2696{
2697 struct strbuf sbuf = STRBUF_INIT;
2698 int ret;
2699
2700 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2701 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
2702 else
2703 ret = -1;
2704 strbuf_release(&sbuf);
2705 return ret;
2706}
2707
ea68b0ce
DP
2708#define SMALL_FILE_SIZE (32*1024)
2709
7b41e1e1
JH
2710static int index_core(unsigned char *sha1, int fd, size_t size,
2711 enum object_type type, const char *path,
2712 unsigned flags)
43df4f86
DP
2713{
2714 int ret;
43df4f86 2715
7b41e1e1 2716 if (!size) {
c4ce46fc 2717 ret = index_mem(sha1, NULL, size, type, path, flags);
ea68b0ce
DP
2718 } else if (size <= SMALL_FILE_SIZE) {
2719 char *buf = xmalloc(size);
2720 if (size == read_in_full(fd, buf, size))
c4ce46fc 2721 ret = index_mem(sha1, buf, size, type, path, flags);
ea68b0ce
DP
2722 else
2723 ret = error("short read %s", strerror(errno));
2724 free(buf);
08bda208 2725 } else {
43df4f86 2726 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
c4ce46fc 2727 ret = index_mem(sha1, buf, size, type, path, flags);
aac17941 2728 munmap(buf, size);
08bda208 2729 }
7b41e1e1
JH
2730 return ret;
2731}
2732
4dd1fbc7 2733/*
568508e7
JH
2734 * This creates one packfile per large blob unless bulk-checkin
2735 * machinery is "plugged".
4dd1fbc7
JH
2736 *
2737 * This also bypasses the usual "convert-to-git" dance, and that is on
2738 * purpose. We could write a streaming version of the converting
2739 * functions and insert that before feeding the data to fast-import
4f22b101
JK
2740 * (or equivalent in-core API described above). However, that is
2741 * somewhat complicated, as we do not know the size of the filter
2742 * result, which we need to know beforehand when writing a git object.
2743 * Since the primary motivation for trying to stream from the working
2744 * tree file and to avoid mmaping it in core is to deal with large
2745 * binary blobs, they generally do not want to get any conversion, and
2746 * callers should avoid this code path when filters are requested.
4dd1fbc7
JH
2747 */
2748static int index_stream(unsigned char *sha1, int fd, size_t size,
2749 enum object_type type, const char *path,
2750 unsigned flags)
2751{
568508e7 2752 return index_bulk_checkin(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
2753}
2754
7b41e1e1
JH
2755int index_fd(unsigned char *sha1, int fd, struct stat *st,
2756 enum object_type type, const char *path, unsigned flags)
2757{
2758 int ret;
2759 size_t size = xsize_t(st->st_size);
2760
2761 if (!S_ISREG(st->st_mode))
2762 ret = index_pipe(sha1, fd, type, path, flags);
4f22b101
JK
2763 else if (size <= big_file_threshold || type != OBJ_BLOB ||
2764 (path && would_convert_to_git(path, NULL, 0, 0)))
7b41e1e1 2765 ret = index_core(sha1, fd, size, type, path, flags);
4dd1fbc7
JH
2766 else
2767 ret = index_stream(sha1, fd, size, type, path, flags);
43df4f86 2768 close(fd);
aac17941 2769 return ret;
74400e71 2770}
ec1fcc16 2771
c4ce46fc 2772int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
ec1fcc16
JH
2773{
2774 int fd;
b760d3aa 2775 struct strbuf sb = STRBUF_INIT;
ec1fcc16
JH
2776
2777 switch (st->st_mode & S_IFMT) {
2778 case S_IFREG:
2779 fd = open(path, O_RDONLY);
2780 if (fd < 0)
2781 return error("open(\"%s\"): %s", path,
2782 strerror(errno));
c4ce46fc 2783 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
ec1fcc16
JH
2784 return error("%s: failed to insert into database",
2785 path);
2786 break;
2787 case S_IFLNK:
b760d3aa 2788 if (strbuf_readlink(&sb, path, st->st_size)) {
ec1fcc16 2789 char *errstr = strerror(errno);
ec1fcc16
JH
2790 return error("readlink(\"%s\"): %s", path,
2791 errstr);
2792 }
c4ce46fc 2793 if (!(flags & HASH_WRITE_OBJECT))
b760d3aa
LT
2794 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2795 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
ec1fcc16
JH
2796 return error("%s: failed to insert into database",
2797 path);
b760d3aa 2798 strbuf_release(&sb);
ec1fcc16 2799 break;
f35a6d3b
LT
2800 case S_IFDIR:
2801 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2802 default:
2803 return error("%s: unsupported file type", path);
2804 }
2805 return 0;
2806}
a69e5429
JH
2807
2808int read_pack_header(int fd, struct pack_header *header)
2809{
c697ad14
HO
2810 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2811 /* "eof before pack header was fully read" */
2812 return PH_ERROR_EOF;
2813
a69e5429
JH
2814 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2815 /* "protocol error (pack signature mismatch detected)" */
2816 return PH_ERROR_PACK_SIGNATURE;
2817 if (!pack_version_ok(header->hdr_version))
2818 /* "protocol error (pack version unsupported)" */
2819 return PH_ERROR_PROTOCOL;
2820 return 0;
2821}
40d52ff7
JK
2822
2823void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
2824{
2825 enum object_type type = sha1_object_info(sha1, NULL);
2826 if (type < 0)
2827 die("%s is not a valid object", sha1_to_hex(sha1));
2828 if (type != expect)
2829 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
2830 typename(expect));
2831}