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 */
9#include "cache.h"
10#include "string-list.h"
11#include "lockfile.h"
12#include "delta.h"
13#include "pack.h"
14#include "blob.h"
15#include "commit.h"
16#include "run-command.h"
17#include "tag.h"
18#include "tree.h"
19#include "tree-walk.h"
20#include "refs.h"
21#include "pack-revindex.h"
22#include "sha1-lookup.h"
23#include "bulk-checkin.h"
24#include "streaming.h"
25#include "dir.h"
26
27#ifndef O_NOATIME
28#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
29#define O_NOATIME 01000000
30#else
31#define O_NOATIME 0
32#endif
33#endif
34
35#define SZ_FMT PRIuMAX
36static inline uintmax_t sz_fmt(size_t s) { return s; }
37
38const unsigned char null_sha1[20];
39
40/*
41 * This is meant to hold a *small* number of objects that you would
42 * want read_sha1_file() to be able to return, but yet you do not want
43 * to write them into the object store (e.g. a browse-only
44 * application).
45 */
46static struct cached_object {
47 unsigned char sha1[20];
48 enum object_type type;
49 void *buf;
50 unsigned long size;
51} *cached_objects;
52static int cached_object_nr, cached_object_alloc;
53
54static struct cached_object empty_tree = {
55 EMPTY_TREE_SHA1_BIN_LITERAL,
56 OBJ_TREE,
57 "",
58 0
59};
60
61/*
62 * A pointer to the last packed_git in which an object was found.
63 * When an object is sought, we look in this packfile first, because
64 * objects that are looked up at similar times are often in the same
65 * packfile as one another.
66 */
67static struct packed_git *last_found_pack;
68
69static struct cached_object *find_cached_object(const unsigned char *sha1)
70{
71 int i;
72 struct cached_object *co = cached_objects;
73
74 for (i = 0; i < cached_object_nr; i++, co++) {
75 if (!hashcmp(co->sha1, sha1))
76 return co;
77 }
78 if (!hashcmp(sha1, empty_tree.sha1))
79 return &empty_tree;
80 return NULL;
81}
82
83int mkdir_in_gitdir(const char *path)
84{
85 if (mkdir(path, 0777)) {
86 int saved_errno = errno;
87 struct stat st;
88 struct strbuf sb = STRBUF_INIT;
89
90 if (errno != EEXIST)
91 return -1;
92 /*
93 * Are we looking at a path in a symlinked worktree
94 * whose original repository does not yet have it?
95 * e.g. .git/rr-cache pointing at its original
96 * repository in which the user hasn't performed any
97 * conflict resolution yet?
98 */
99 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
100 strbuf_readlink(&sb, path, st.st_size) ||
101 !is_absolute_path(sb.buf) ||
102 mkdir(sb.buf, 0777)) {
103 strbuf_release(&sb);
104 errno = saved_errno;
105 return -1;
106 }
107 strbuf_release(&sb);
108 }
109 return adjust_shared_perm(path);
110}
111
112enum scld_error safe_create_leading_directories(char *path)
113{
114 char *next_component = path + offset_1st_component(path);
115 enum scld_error ret = SCLD_OK;
116
117 while (ret == SCLD_OK && next_component) {
118 struct stat st;
119 char *slash = next_component, slash_character;
120
121 while (*slash && !is_dir_sep(*slash))
122 slash++;
123
124 if (!*slash)
125 break;
126
127 next_component = slash + 1;
128 while (is_dir_sep(*next_component))
129 next_component++;
130 if (!*next_component)
131 break;
132
133 slash_character = *slash;
134 *slash = '\0';
135 if (!stat(path, &st)) {
136 /* path exists */
137 if (!S_ISDIR(st.st_mode))
138 ret = SCLD_EXISTS;
139 } else if (mkdir(path, 0777)) {
140 if (errno == EEXIST &&
141 !stat(path, &st) && S_ISDIR(st.st_mode))
142 ; /* somebody created it since we checked */
143 else if (errno == ENOENT)
144 /*
145 * Either mkdir() failed because
146 * somebody just pruned the containing
147 * directory, or stat() failed because
148 * the file that was in our way was
149 * just removed. Either way, inform
150 * the caller that it might be worth
151 * trying again:
152 */
153 ret = SCLD_VANISHED;
154 else
155 ret = SCLD_FAILED;
156 } else if (adjust_shared_perm(path)) {
157 ret = SCLD_PERMS;
158 }
159 *slash = slash_character;
160 }
161 return ret;
162}
163
164enum scld_error safe_create_leading_directories_const(const char *path)
165{
166 /* path points to cache entries, so xstrdup before messing with it */
167 char *buf = xstrdup(path);
168 enum scld_error result = safe_create_leading_directories(buf);
169 free(buf);
170 return result;
171}
172
173static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
174{
175 int i;
176 for (i = 0; i < 20; i++) {
177 static char hex[] = "0123456789abcdef";
178 unsigned int val = sha1[i];
179 char *pos = pathbuf + i*2 + (i > 0);
180 *pos++ = hex[val >> 4];
181 *pos = hex[val & 0xf];
182 }
183}
184
185const char *sha1_file_name(const unsigned char *sha1)
186{
187 static char buf[PATH_MAX];
188 const char *objdir;
189 int len;
190
191 objdir = get_object_directory();
192 len = strlen(objdir);
193
194 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
195 if (len + 43 > PATH_MAX)
196 die("insanely long object directory %s", objdir);
197 memcpy(buf, objdir, len);
198 buf[len] = '/';
199 buf[len+3] = '/';
200 buf[len+42] = '\0';
201 fill_sha1_path(buf + len + 1, sha1);
202 return buf;
203}
204
205/*
206 * Return the name of the pack or index file with the specified sha1
207 * in its filename. *base and *name are scratch space that must be
208 * provided by the caller. which should be "pack" or "idx".
209 */
210static char *sha1_get_pack_name(const unsigned char *sha1,
211 char **name, char **base, const char *which)
212{
213 static const char hex[] = "0123456789abcdef";
214 char *buf;
215 int i;
216
217 if (!*base) {
218 const char *sha1_file_directory = get_object_directory();
219 int len = strlen(sha1_file_directory);
220 *base = xmalloc(len + 60);
221 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
222 sha1_file_directory, which);
223 *name = *base + len + 11;
224 }
225
226 buf = *name;
227
228 for (i = 0; i < 20; i++) {
229 unsigned int val = *sha1++;
230 *buf++ = hex[val >> 4];
231 *buf++ = hex[val & 0xf];
232 }
233
234 return *base;
235}
236
237char *sha1_pack_name(const unsigned char *sha1)
238{
239 static char *name, *base;
240
241 return sha1_get_pack_name(sha1, &name, &base, "pack");
242}
243
244char *sha1_pack_index_name(const unsigned char *sha1)
245{
246 static char *name, *base;
247
248 return sha1_get_pack_name(sha1, &name, &base, "idx");
249}
250
251struct alternate_object_database *alt_odb_list;
252static struct alternate_object_database **alt_odb_tail;
253
254/*
255 * Prepare alternate object database registry.
256 *
257 * The variable alt_odb_list points at the list of struct
258 * alternate_object_database. The elements on this list come from
259 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
260 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
261 * whose contents is similar to that environment variable but can be
262 * LF separated. Its base points at a statically allocated buffer that
263 * contains "/the/directory/corresponding/to/.git/objects/...", while
264 * its name points just after the slash at the end of ".git/objects/"
265 * in the example above, and has enough space to hold 40-byte hex
266 * SHA1, an extra slash for the first level indirection, and the
267 * terminating NUL.
268 */
269static int link_alt_odb_entry(const char *entry, const char *relative_base,
270 int depth, const char *normalized_objdir)
271{
272 struct alternate_object_database *ent;
273 struct alternate_object_database *alt;
274 int pfxlen, entlen;
275 struct strbuf pathbuf = STRBUF_INIT;
276
277 if (!is_absolute_path(entry) && relative_base) {
278 strbuf_addstr(&pathbuf, real_path(relative_base));
279 strbuf_addch(&pathbuf, '/');
280 }
281 strbuf_addstr(&pathbuf, entry);
282
283 normalize_path_copy(pathbuf.buf, pathbuf.buf);
284
285 pfxlen = strlen(pathbuf.buf);
286
287 /*
288 * The trailing slash after the directory name is given by
289 * this function at the end. Remove duplicates.
290 */
291 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
292 pfxlen -= 1;
293
294 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
295 ent = xmalloc(sizeof(*ent) + entlen);
296 memcpy(ent->base, pathbuf.buf, pfxlen);
297 strbuf_release(&pathbuf);
298
299 ent->name = ent->base + pfxlen + 1;
300 ent->base[pfxlen + 3] = '/';
301 ent->base[pfxlen] = ent->base[entlen-1] = 0;
302
303 /* Detect cases where alternate disappeared */
304 if (!is_directory(ent->base)) {
305 error("object directory %s does not exist; "
306 "check .git/objects/info/alternates.",
307 ent->base);
308 free(ent);
309 return -1;
310 }
311
312 /* Prevent the common mistake of listing the same
313 * thing twice, or object directory itself.
314 */
315 for (alt = alt_odb_list; alt; alt = alt->next) {
316 if (pfxlen == alt->name - alt->base - 1 &&
317 !memcmp(ent->base, alt->base, pfxlen)) {
318 free(ent);
319 return -1;
320 }
321 }
322 if (!strcmp_icase(ent->base, normalized_objdir)) {
323 free(ent);
324 return -1;
325 }
326
327 /* add the alternate entry */
328 *alt_odb_tail = ent;
329 alt_odb_tail = &(ent->next);
330 ent->next = NULL;
331
332 /* recursively add alternates */
333 read_info_alternates(ent->base, depth + 1);
334
335 ent->base[pfxlen] = '/';
336
337 return 0;
338}
339
340static void link_alt_odb_entries(const char *alt, int len, int sep,
341 const char *relative_base, int depth)
342{
343 struct string_list entries = STRING_LIST_INIT_NODUP;
344 char *alt_copy;
345 int i;
346 struct strbuf objdirbuf = STRBUF_INIT;
347
348 if (depth > 5) {
349 error("%s: ignoring alternate object stores, nesting too deep.",
350 relative_base);
351 return;
352 }
353
354 strbuf_add_absolute_path(&objdirbuf, get_object_directory());
355 normalize_path_copy(objdirbuf.buf, objdirbuf.buf);
356
357 alt_copy = xmemdupz(alt, len);
358 string_list_split_in_place(&entries, alt_copy, sep, -1);
359 for (i = 0; i < entries.nr; i++) {
360 const char *entry = entries.items[i].string;
361 if (entry[0] == '\0' || entry[0] == '#')
362 continue;
363 if (!is_absolute_path(entry) && depth) {
364 error("%s: ignoring relative alternate object store %s",
365 relative_base, entry);
366 } else {
367 link_alt_odb_entry(entry, relative_base, depth, objdirbuf.buf);
368 }
369 }
370 string_list_clear(&entries, 0);
371 free(alt_copy);
372 strbuf_release(&objdirbuf);
373}
374
375void read_info_alternates(const char * relative_base, int depth)
376{
377 char *map;
378 size_t mapsz;
379 struct stat st;
380 char *path;
381 int fd;
382
383 path = xstrfmt("%s/info/alternates", relative_base);
384 fd = git_open_noatime(path);
385 free(path);
386 if (fd < 0)
387 return;
388 if (fstat(fd, &st) || (st.st_size == 0)) {
389 close(fd);
390 return;
391 }
392 mapsz = xsize_t(st.st_size);
393 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
394 close(fd);
395
396 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
397
398 munmap(map, mapsz);
399}
400
401void add_to_alternates_file(const char *reference)
402{
403 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
404 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
405 char *alt = mkpath("%s\n", reference);
406 write_or_die(fd, alt, strlen(alt));
407 if (commit_lock_file(lock))
408 die("could not close alternates file");
409 if (alt_odb_tail)
410 link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
411}
412
413int foreach_alt_odb(alt_odb_fn fn, void *cb)
414{
415 struct alternate_object_database *ent;
416 int r = 0;
417
418 prepare_alt_odb();
419 for (ent = alt_odb_list; ent; ent = ent->next) {
420 r = fn(ent, cb);
421 if (r)
422 break;
423 }
424 return r;
425}
426
427void prepare_alt_odb(void)
428{
429 const char *alt;
430
431 if (alt_odb_tail)
432 return;
433
434 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
435 if (!alt) alt = "";
436
437 alt_odb_tail = &alt_odb_list;
438 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
439
440 read_info_alternates(get_object_directory(), 0);
441}
442
443static int freshen_file(const char *fn)
444{
445 struct utimbuf t;
446 t.actime = t.modtime = time(NULL);
447 return !utime(fn, &t);
448}
449
450static int check_and_freshen_file(const char *fn, int freshen)
451{
452 if (access(fn, F_OK))
453 return 0;
454 if (freshen && freshen_file(fn))
455 return 0;
456 return 1;
457}
458
459static int check_and_freshen_local(const unsigned char *sha1, int freshen)
460{
461 return check_and_freshen_file(sha1_file_name(sha1), freshen);
462}
463
464static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
465{
466 struct alternate_object_database *alt;
467 prepare_alt_odb();
468 for (alt = alt_odb_list; alt; alt = alt->next) {
469 fill_sha1_path(alt->name, sha1);
470 if (check_and_freshen_file(alt->base, freshen))
471 return 1;
472 }
473 return 0;
474}
475
476static int check_and_freshen(const unsigned char *sha1, int freshen)
477{
478 return check_and_freshen_local(sha1, freshen) ||
479 check_and_freshen_nonlocal(sha1, freshen);
480}
481
482int has_loose_object_nonlocal(const unsigned char *sha1)
483{
484 return check_and_freshen_nonlocal(sha1, 0);
485}
486
487static int has_loose_object(const unsigned char *sha1)
488{
489 return check_and_freshen(sha1, 0);
490}
491
492static unsigned int pack_used_ctr;
493static unsigned int pack_mmap_calls;
494static unsigned int peak_pack_open_windows;
495static unsigned int pack_open_windows;
496static unsigned int pack_open_fds;
497static unsigned int pack_max_fds;
498static size_t peak_pack_mapped;
499static size_t pack_mapped;
500struct packed_git *packed_git;
501
502void pack_report(void)
503{
504 fprintf(stderr,
505 "pack_report: getpagesize() = %10" SZ_FMT "\n"
506 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
507 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
508 sz_fmt(getpagesize()),
509 sz_fmt(packed_git_window_size),
510 sz_fmt(packed_git_limit));
511 fprintf(stderr,
512 "pack_report: pack_used_ctr = %10u\n"
513 "pack_report: pack_mmap_calls = %10u\n"
514 "pack_report: pack_open_windows = %10u / %10u\n"
515 "pack_report: pack_mapped = "
516 "%10" SZ_FMT " / %10" SZ_FMT "\n",
517 pack_used_ctr,
518 pack_mmap_calls,
519 pack_open_windows, peak_pack_open_windows,
520 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
521}
522
523/*
524 * Open and mmap the index file at path, perform a couple of
525 * consistency checks, then record its information to p. Return 0 on
526 * success.
527 */
528static int check_packed_git_idx(const char *path, struct packed_git *p)
529{
530 void *idx_map;
531 struct pack_idx_header *hdr;
532 size_t idx_size;
533 uint32_t version, nr, i, *index;
534 int fd = git_open_noatime(path);
535 struct stat st;
536
537 if (fd < 0)
538 return -1;
539 if (fstat(fd, &st)) {
540 close(fd);
541 return -1;
542 }
543 idx_size = xsize_t(st.st_size);
544 if (idx_size < 4 * 256 + 20 + 20) {
545 close(fd);
546 return error("index file %s is too small", path);
547 }
548 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
549 close(fd);
550
551 hdr = idx_map;
552 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
553 version = ntohl(hdr->idx_version);
554 if (version < 2 || version > 2) {
555 munmap(idx_map, idx_size);
556 return error("index file %s is version %"PRIu32
557 " and is not supported by this binary"
558 " (try upgrading GIT to a newer version)",
559 path, version);
560 }
561 } else
562 version = 1;
563
564 nr = 0;
565 index = idx_map;
566 if (version > 1)
567 index += 2; /* skip index header */
568 for (i = 0; i < 256; i++) {
569 uint32_t n = ntohl(index[i]);
570 if (n < nr) {
571 munmap(idx_map, idx_size);
572 return error("non-monotonic index %s", path);
573 }
574 nr = n;
575 }
576
577 if (version == 1) {
578 /*
579 * Total size:
580 * - 256 index entries 4 bytes each
581 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
582 * - 20-byte SHA1 of the packfile
583 * - 20-byte SHA1 file checksum
584 */
585 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
586 munmap(idx_map, idx_size);
587 return error("wrong index v1 file size in %s", path);
588 }
589 } else if (version == 2) {
590 /*
591 * Minimum size:
592 * - 8 bytes of header
593 * - 256 index entries 4 bytes each
594 * - 20-byte sha1 entry * nr
595 * - 4-byte crc entry * nr
596 * - 4-byte offset entry * nr
597 * - 20-byte SHA1 of the packfile
598 * - 20-byte SHA1 file checksum
599 * And after the 4-byte offset table might be a
600 * variable sized table containing 8-byte entries
601 * for offsets larger than 2^31.
602 */
603 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
604 unsigned long max_size = min_size;
605 if (nr)
606 max_size += (nr - 1)*8;
607 if (idx_size < min_size || idx_size > max_size) {
608 munmap(idx_map, idx_size);
609 return error("wrong index v2 file size in %s", path);
610 }
611 if (idx_size != min_size &&
612 /*
613 * make sure we can deal with large pack offsets.
614 * 31-bit signed offset won't be enough, neither
615 * 32-bit unsigned one will be.
616 */
617 (sizeof(off_t) <= 4)) {
618 munmap(idx_map, idx_size);
619 return error("pack too large for current definition of off_t in %s", path);
620 }
621 }
622
623 p->index_version = version;
624 p->index_data = idx_map;
625 p->index_size = idx_size;
626 p->num_objects = nr;
627 return 0;
628}
629
630int open_pack_index(struct packed_git *p)
631{
632 char *idx_name;
633 int ret;
634
635 if (p->index_data)
636 return 0;
637
638 idx_name = xstrdup(p->pack_name);
639 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
640 ret = check_packed_git_idx(idx_name, p);
641 free(idx_name);
642 return ret;
643}
644
645static void scan_windows(struct packed_git *p,
646 struct packed_git **lru_p,
647 struct pack_window **lru_w,
648 struct pack_window **lru_l)
649{
650 struct pack_window *w, *w_l;
651
652 for (w_l = NULL, w = p->windows; w; w = w->next) {
653 if (!w->inuse_cnt) {
654 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
655 *lru_p = p;
656 *lru_w = w;
657 *lru_l = w_l;
658 }
659 }
660 w_l = w;
661 }
662}
663
664static int unuse_one_window(struct packed_git *current)
665{
666 struct packed_git *p, *lru_p = NULL;
667 struct pack_window *lru_w = NULL, *lru_l = NULL;
668
669 if (current)
670 scan_windows(current, &lru_p, &lru_w, &lru_l);
671 for (p = packed_git; p; p = p->next)
672 scan_windows(p, &lru_p, &lru_w, &lru_l);
673 if (lru_p) {
674 munmap(lru_w->base, lru_w->len);
675 pack_mapped -= lru_w->len;
676 if (lru_l)
677 lru_l->next = lru_w->next;
678 else
679 lru_p->windows = lru_w->next;
680 free(lru_w);
681 pack_open_windows--;
682 return 1;
683 }
684 return 0;
685}
686
687void release_pack_memory(size_t need)
688{
689 size_t cur = pack_mapped;
690 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
691 ; /* nothing */
692}
693
694static void mmap_limit_check(size_t length)
695{
696 static size_t limit = 0;
697 if (!limit) {
698 limit = git_env_ulong("GIT_MMAP_LIMIT", 0);
699 if (!limit)
700 limit = SIZE_MAX;
701 }
702 if (length > limit)
703 die("attempting to mmap %"PRIuMAX" over limit %"PRIuMAX,
704 (uintmax_t)length, (uintmax_t)limit);
705}
706
707void *xmmap(void *start, size_t length,
708 int prot, int flags, int fd, off_t offset)
709{
710 void *ret;
711
712 mmap_limit_check(length);
713 ret = mmap(start, length, prot, flags, fd, offset);
714 if (ret == MAP_FAILED) {
715 if (!length)
716 return NULL;
717 release_pack_memory(length);
718 ret = mmap(start, length, prot, flags, fd, offset);
719 if (ret == MAP_FAILED)
720 die_errno("Out of memory? mmap failed");
721 }
722 return ret;
723}
724
725void close_pack_windows(struct packed_git *p)
726{
727 while (p->windows) {
728 struct pack_window *w = p->windows;
729
730 if (w->inuse_cnt)
731 die("pack '%s' still has open windows to it",
732 p->pack_name);
733 munmap(w->base, w->len);
734 pack_mapped -= w->len;
735 pack_open_windows--;
736 p->windows = w->next;
737 free(w);
738 }
739}
740
741/*
742 * The LRU pack is the one with the oldest MRU window, preferring packs
743 * with no used windows, or the oldest mtime if it has no windows allocated.
744 */
745static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
746{
747 struct pack_window *w, *this_mru_w;
748 int has_windows_inuse = 0;
749
750 /*
751 * Reject this pack if it has windows and the previously selected
752 * one does not. If this pack does not have windows, reject
753 * it if the pack file is newer than the previously selected one.
754 */
755 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
756 return;
757
758 for (w = this_mru_w = p->windows; w; w = w->next) {
759 /*
760 * Reject this pack if any of its windows are in use,
761 * but the previously selected pack did not have any
762 * inuse windows. Otherwise, record that this pack
763 * has windows in use.
764 */
765 if (w->inuse_cnt) {
766 if (*accept_windows_inuse)
767 has_windows_inuse = 1;
768 else
769 return;
770 }
771
772 if (w->last_used > this_mru_w->last_used)
773 this_mru_w = w;
774
775 /*
776 * Reject this pack if it has windows that have been
777 * used more recently than the previously selected pack.
778 * If the previously selected pack had windows inuse and
779 * we have not encountered a window in this pack that is
780 * inuse, skip this check since we prefer a pack with no
781 * inuse windows to one that has inuse windows.
782 */
783 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
784 this_mru_w->last_used > (*mru_w)->last_used)
785 return;
786 }
787
788 /*
789 * Select this pack.
790 */
791 *mru_w = this_mru_w;
792 *lru_p = p;
793 *accept_windows_inuse = has_windows_inuse;
794}
795
796static int close_one_pack(void)
797{
798 struct packed_git *p, *lru_p = NULL;
799 struct pack_window *mru_w = NULL;
800 int accept_windows_inuse = 1;
801
802 for (p = packed_git; p; p = p->next) {
803 if (p->pack_fd == -1)
804 continue;
805 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
806 }
807
808 if (lru_p) {
809 close(lru_p->pack_fd);
810 pack_open_fds--;
811 lru_p->pack_fd = -1;
812 return 1;
813 }
814
815 return 0;
816}
817
818void unuse_pack(struct pack_window **w_cursor)
819{
820 struct pack_window *w = *w_cursor;
821 if (w) {
822 w->inuse_cnt--;
823 *w_cursor = NULL;
824 }
825}
826
827void close_pack_index(struct packed_git *p)
828{
829 if (p->index_data) {
830 munmap((void *)p->index_data, p->index_size);
831 p->index_data = NULL;
832 }
833}
834
835/*
836 * This is used by git-repack in case a newly created pack happens to
837 * contain the same set of objects as an existing one. In that case
838 * the resulting file might be different even if its name would be the
839 * same. It is best to close any reference to the old pack before it is
840 * replaced on disk. Of course no index pointers or windows for given pack
841 * must subsist at this point. If ever objects from this pack are requested
842 * again, the new version of the pack will be reinitialized through
843 * reprepare_packed_git().
844 */
845void free_pack_by_name(const char *pack_name)
846{
847 struct packed_git *p, **pp = &packed_git;
848
849 while (*pp) {
850 p = *pp;
851 if (strcmp(pack_name, p->pack_name) == 0) {
852 clear_delta_base_cache();
853 close_pack_windows(p);
854 if (p->pack_fd != -1) {
855 close(p->pack_fd);
856 pack_open_fds--;
857 }
858 close_pack_index(p);
859 free(p->bad_object_sha1);
860 *pp = p->next;
861 if (last_found_pack == p)
862 last_found_pack = NULL;
863 free(p);
864 return;
865 }
866 pp = &p->next;
867 }
868}
869
870static unsigned int get_max_fd_limit(void)
871{
872#ifdef RLIMIT_NOFILE
873 {
874 struct rlimit lim;
875
876 if (!getrlimit(RLIMIT_NOFILE, &lim))
877 return lim.rlim_cur;
878 }
879#endif
880
881#ifdef _SC_OPEN_MAX
882 {
883 long open_max = sysconf(_SC_OPEN_MAX);
884 if (0 < open_max)
885 return open_max;
886 /*
887 * Otherwise, we got -1 for one of the two
888 * reasons:
889 *
890 * (1) sysconf() did not understand _SC_OPEN_MAX
891 * and signaled an error with -1; or
892 * (2) sysconf() said there is no limit.
893 *
894 * We _could_ clear errno before calling sysconf() to
895 * tell these two cases apart and return a huge number
896 * in the latter case to let the caller cap it to a
897 * value that is not so selfish, but letting the
898 * fallback OPEN_MAX codepath take care of these cases
899 * is a lot simpler.
900 */
901 }
902#endif
903
904#ifdef OPEN_MAX
905 return OPEN_MAX;
906#else
907 return 1; /* see the caller ;-) */
908#endif
909}
910
911/*
912 * Do not call this directly as this leaks p->pack_fd on error return;
913 * call open_packed_git() instead.
914 */
915static int open_packed_git_1(struct packed_git *p)
916{
917 struct stat st;
918 struct pack_header hdr;
919 unsigned char sha1[20];
920 unsigned char *idx_sha1;
921 long fd_flag;
922
923 if (!p->index_data && open_pack_index(p))
924 return error("packfile %s index unavailable", p->pack_name);
925
926 if (!pack_max_fds) {
927 unsigned int max_fds = get_max_fd_limit();
928
929 /* Save 3 for stdin/stdout/stderr, 22 for work */
930 if (25 < max_fds)
931 pack_max_fds = max_fds - 25;
932 else
933 pack_max_fds = 1;
934 }
935
936 while (pack_max_fds <= pack_open_fds && close_one_pack())
937 ; /* nothing */
938
939 p->pack_fd = git_open_noatime(p->pack_name);
940 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
941 return -1;
942 pack_open_fds++;
943
944 /* If we created the struct before we had the pack we lack size. */
945 if (!p->pack_size) {
946 if (!S_ISREG(st.st_mode))
947 return error("packfile %s not a regular file", p->pack_name);
948 p->pack_size = st.st_size;
949 } else if (p->pack_size != st.st_size)
950 return error("packfile %s size changed", p->pack_name);
951
952 /* We leave these file descriptors open with sliding mmap;
953 * there is no point keeping them open across exec(), though.
954 */
955 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
956 if (fd_flag < 0)
957 return error("cannot determine file descriptor flags");
958 fd_flag |= FD_CLOEXEC;
959 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
960 return error("cannot set FD_CLOEXEC");
961
962 /* Verify we recognize this pack file format. */
963 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
964 return error("file %s is far too short to be a packfile", p->pack_name);
965 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
966 return error("file %s is not a GIT packfile", p->pack_name);
967 if (!pack_version_ok(hdr.hdr_version))
968 return error("packfile %s is version %"PRIu32" and not"
969 " supported (try upgrading GIT to a newer version)",
970 p->pack_name, ntohl(hdr.hdr_version));
971
972 /* Verify the pack matches its index. */
973 if (p->num_objects != ntohl(hdr.hdr_entries))
974 return error("packfile %s claims to have %"PRIu32" objects"
975 " while index indicates %"PRIu32" objects",
976 p->pack_name, ntohl(hdr.hdr_entries),
977 p->num_objects);
978 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
979 return error("end of packfile %s is unavailable", p->pack_name);
980 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
981 return error("packfile %s signature is unavailable", p->pack_name);
982 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
983 if (hashcmp(sha1, idx_sha1))
984 return error("packfile %s does not match index", p->pack_name);
985 return 0;
986}
987
988static int open_packed_git(struct packed_git *p)
989{
990 if (!open_packed_git_1(p))
991 return 0;
992 if (p->pack_fd != -1) {
993 close(p->pack_fd);
994 pack_open_fds--;
995 p->pack_fd = -1;
996 }
997 return -1;
998}
999
1000static int in_window(struct pack_window *win, off_t offset)
1001{
1002 /* We must promise at least 20 bytes (one hash) after the
1003 * offset is available from this window, otherwise the offset
1004 * is not actually in this window and a different window (which
1005 * has that one hash excess) must be used. This is to support
1006 * the object header and delta base parsing routines below.
1007 */
1008 off_t win_off = win->offset;
1009 return win_off <= offset
1010 && (offset + 20) <= (win_off + win->len);
1011}
1012
1013unsigned char *use_pack(struct packed_git *p,
1014 struct pack_window **w_cursor,
1015 off_t offset,
1016 unsigned long *left)
1017{
1018 struct pack_window *win = *w_cursor;
1019
1020 /* Since packfiles end in a hash of their content and it's
1021 * pointless to ask for an offset into the middle of that
1022 * hash, and the in_window function above wouldn't match
1023 * don't allow an offset too close to the end of the file.
1024 */
1025 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
1026 die("packfile %s cannot be accessed", p->pack_name);
1027 if (offset > (p->pack_size - 20))
1028 die("offset beyond end of packfile (truncated pack?)");
1029
1030 if (!win || !in_window(win, offset)) {
1031 if (win)
1032 win->inuse_cnt--;
1033 for (win = p->windows; win; win = win->next) {
1034 if (in_window(win, offset))
1035 break;
1036 }
1037 if (!win) {
1038 size_t window_align = packed_git_window_size / 2;
1039 off_t len;
1040
1041 if (p->pack_fd == -1 && open_packed_git(p))
1042 die("packfile %s cannot be accessed", p->pack_name);
1043
1044 win = xcalloc(1, sizeof(*win));
1045 win->offset = (offset / window_align) * window_align;
1046 len = p->pack_size - win->offset;
1047 if (len > packed_git_window_size)
1048 len = packed_git_window_size;
1049 win->len = (size_t)len;
1050 pack_mapped += win->len;
1051 while (packed_git_limit < pack_mapped
1052 && unuse_one_window(p))
1053 ; /* nothing */
1054 win->base = xmmap(NULL, win->len,
1055 PROT_READ, MAP_PRIVATE,
1056 p->pack_fd, win->offset);
1057 if (win->base == MAP_FAILED)
1058 die("packfile %s cannot be mapped: %s",
1059 p->pack_name,
1060 strerror(errno));
1061 if (!win->offset && win->len == p->pack_size
1062 && !p->do_not_close) {
1063 close(p->pack_fd);
1064 pack_open_fds--;
1065 p->pack_fd = -1;
1066 }
1067 pack_mmap_calls++;
1068 pack_open_windows++;
1069 if (pack_mapped > peak_pack_mapped)
1070 peak_pack_mapped = pack_mapped;
1071 if (pack_open_windows > peak_pack_open_windows)
1072 peak_pack_open_windows = pack_open_windows;
1073 win->next = p->windows;
1074 p->windows = win;
1075 }
1076 }
1077 if (win != *w_cursor) {
1078 win->last_used = pack_used_ctr++;
1079 win->inuse_cnt++;
1080 *w_cursor = win;
1081 }
1082 offset -= win->offset;
1083 if (left)
1084 *left = win->len - xsize_t(offset);
1085 return win->base + offset;
1086}
1087
1088static struct packed_git *alloc_packed_git(int extra)
1089{
1090 struct packed_git *p = xmalloc(sizeof(*p) + extra);
1091 memset(p, 0, sizeof(*p));
1092 p->pack_fd = -1;
1093 return p;
1094}
1095
1096static void try_to_free_pack_memory(size_t size)
1097{
1098 release_pack_memory(size);
1099}
1100
1101struct packed_git *add_packed_git(const char *path, int path_len, int local)
1102{
1103 static int have_set_try_to_free_routine;
1104 struct stat st;
1105 struct packed_git *p = alloc_packed_git(path_len + 2);
1106
1107 if (!have_set_try_to_free_routine) {
1108 have_set_try_to_free_routine = 1;
1109 set_try_to_free_routine(try_to_free_pack_memory);
1110 }
1111
1112 /*
1113 * Make sure a corresponding .pack file exists and that
1114 * the index looks sane.
1115 */
1116 path_len -= strlen(".idx");
1117 if (path_len < 1) {
1118 free(p);
1119 return NULL;
1120 }
1121 memcpy(p->pack_name, path, path_len);
1122
1123 strcpy(p->pack_name + path_len, ".keep");
1124 if (!access(p->pack_name, F_OK))
1125 p->pack_keep = 1;
1126
1127 strcpy(p->pack_name + path_len, ".pack");
1128 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
1129 free(p);
1130 return NULL;
1131 }
1132
1133 /* ok, it looks sane as far as we can check without
1134 * actually mapping the pack file.
1135 */
1136 p->pack_size = st.st_size;
1137 p->pack_local = local;
1138 p->mtime = st.st_mtime;
1139 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1140 hashclr(p->sha1);
1141 return p;
1142}
1143
1144struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
1145{
1146 const char *path = sha1_pack_name(sha1);
1147 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
1148
1149 strcpy(p->pack_name, path);
1150 hashcpy(p->sha1, sha1);
1151 if (check_packed_git_idx(idx_path, p)) {
1152 free(p);
1153 return NULL;
1154 }
1155
1156 return p;
1157}
1158
1159void install_packed_git(struct packed_git *pack)
1160{
1161 if (pack->pack_fd != -1)
1162 pack_open_fds++;
1163
1164 pack->next = packed_git;
1165 packed_git = pack;
1166}
1167
1168void (*report_garbage)(const char *desc, const char *path);
1169
1170static void report_helper(const struct string_list *list,
1171 int seen_bits, int first, int last)
1172{
1173 const char *msg;
1174 switch (seen_bits) {
1175 case 0:
1176 msg = "no corresponding .idx or .pack";
1177 break;
1178 case 1:
1179 msg = "no corresponding .idx";
1180 break;
1181 case 2:
1182 msg = "no corresponding .pack";
1183 break;
1184 default:
1185 return;
1186 }
1187 for (; first < last; first++)
1188 report_garbage(msg, list->items[first].string);
1189}
1190
1191static void report_pack_garbage(struct string_list *list)
1192{
1193 int i, baselen = -1, first = 0, seen_bits = 0;
1194
1195 if (!report_garbage)
1196 return;
1197
1198 sort_string_list(list);
1199
1200 for (i = 0; i < list->nr; i++) {
1201 const char *path = list->items[i].string;
1202 if (baselen != -1 &&
1203 strncmp(path, list->items[first].string, baselen)) {
1204 report_helper(list, seen_bits, first, i);
1205 baselen = -1;
1206 seen_bits = 0;
1207 }
1208 if (baselen == -1) {
1209 const char *dot = strrchr(path, '.');
1210 if (!dot) {
1211 report_garbage("garbage found", path);
1212 continue;
1213 }
1214 baselen = dot - path + 1;
1215 first = i;
1216 }
1217 if (!strcmp(path + baselen, "pack"))
1218 seen_bits |= 1;
1219 else if (!strcmp(path + baselen, "idx"))
1220 seen_bits |= 2;
1221 }
1222 report_helper(list, seen_bits, first, list->nr);
1223}
1224
1225static void prepare_packed_git_one(char *objdir, int local)
1226{
1227 struct strbuf path = STRBUF_INIT;
1228 size_t dirnamelen;
1229 DIR *dir;
1230 struct dirent *de;
1231 struct string_list garbage = STRING_LIST_INIT_DUP;
1232
1233 strbuf_addstr(&path, objdir);
1234 strbuf_addstr(&path, "/pack");
1235 dir = opendir(path.buf);
1236 if (!dir) {
1237 if (errno != ENOENT)
1238 error("unable to open object pack directory: %s: %s",
1239 path.buf, strerror(errno));
1240 strbuf_release(&path);
1241 return;
1242 }
1243 strbuf_addch(&path, '/');
1244 dirnamelen = path.len;
1245 while ((de = readdir(dir)) != NULL) {
1246 struct packed_git *p;
1247 size_t base_len;
1248
1249 if (is_dot_or_dotdot(de->d_name))
1250 continue;
1251
1252 strbuf_setlen(&path, dirnamelen);
1253 strbuf_addstr(&path, de->d_name);
1254
1255 base_len = path.len;
1256 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
1257 /* Don't reopen a pack we already have. */
1258 for (p = packed_git; p; p = p->next) {
1259 size_t len;
1260 if (strip_suffix(p->pack_name, ".pack", &len) &&
1261 len == base_len &&
1262 !memcmp(p->pack_name, path.buf, len))
1263 break;
1264 }
1265 if (p == NULL &&
1266 /*
1267 * See if it really is a valid .idx file with
1268 * corresponding .pack file that we can map.
1269 */
1270 (p = add_packed_git(path.buf, path.len, local)) != NULL)
1271 install_packed_git(p);
1272 }
1273
1274 if (!report_garbage)
1275 continue;
1276
1277 if (ends_with(de->d_name, ".idx") ||
1278 ends_with(de->d_name, ".pack") ||
1279 ends_with(de->d_name, ".bitmap") ||
1280 ends_with(de->d_name, ".keep"))
1281 string_list_append(&garbage, path.buf);
1282 else
1283 report_garbage("garbage found", path.buf);
1284 }
1285 closedir(dir);
1286 report_pack_garbage(&garbage);
1287 string_list_clear(&garbage, 0);
1288 strbuf_release(&path);
1289}
1290
1291static int sort_pack(const void *a_, const void *b_)
1292{
1293 struct packed_git *a = *((struct packed_git **)a_);
1294 struct packed_git *b = *((struct packed_git **)b_);
1295 int st;
1296
1297 /*
1298 * Local packs tend to contain objects specific to our
1299 * variant of the project than remote ones. In addition,
1300 * remote ones could be on a network mounted filesystem.
1301 * Favor local ones for these reasons.
1302 */
1303 st = a->pack_local - b->pack_local;
1304 if (st)
1305 return -st;
1306
1307 /*
1308 * Younger packs tend to contain more recent objects,
1309 * and more recent objects tend to get accessed more
1310 * often.
1311 */
1312 if (a->mtime < b->mtime)
1313 return 1;
1314 else if (a->mtime == b->mtime)
1315 return 0;
1316 return -1;
1317}
1318
1319static void rearrange_packed_git(void)
1320{
1321 struct packed_git **ary, *p;
1322 int i, n;
1323
1324 for (n = 0, p = packed_git; p; p = p->next)
1325 n++;
1326 if (n < 2)
1327 return;
1328
1329 /* prepare an array of packed_git for easier sorting */
1330 ary = xcalloc(n, sizeof(struct packed_git *));
1331 for (n = 0, p = packed_git; p; p = p->next)
1332 ary[n++] = p;
1333
1334 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1335
1336 /* link them back again */
1337 for (i = 0; i < n - 1; i++)
1338 ary[i]->next = ary[i + 1];
1339 ary[n - 1]->next = NULL;
1340 packed_git = ary[0];
1341
1342 free(ary);
1343}
1344
1345static int prepare_packed_git_run_once = 0;
1346void prepare_packed_git(void)
1347{
1348 struct alternate_object_database *alt;
1349
1350 if (prepare_packed_git_run_once)
1351 return;
1352 prepare_packed_git_one(get_object_directory(), 1);
1353 prepare_alt_odb();
1354 for (alt = alt_odb_list; alt; alt = alt->next) {
1355 alt->name[-1] = 0;
1356 prepare_packed_git_one(alt->base, 0);
1357 alt->name[-1] = '/';
1358 }
1359 rearrange_packed_git();
1360 prepare_packed_git_run_once = 1;
1361}
1362
1363void reprepare_packed_git(void)
1364{
1365 prepare_packed_git_run_once = 0;
1366 prepare_packed_git();
1367}
1368
1369static void mark_bad_packed_object(struct packed_git *p,
1370 const unsigned char *sha1)
1371{
1372 unsigned i;
1373 for (i = 0; i < p->num_bad_objects; i++)
1374 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1375 return;
1376 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1377 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1378 p->num_bad_objects++;
1379}
1380
1381static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1382{
1383 struct packed_git *p;
1384 unsigned i;
1385
1386 for (p = packed_git; p; p = p->next)
1387 for (i = 0; i < p->num_bad_objects; i++)
1388 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1389 return p;
1390 return NULL;
1391}
1392
1393/*
1394 * With an in-core object data in "map", rehash it to make sure the
1395 * object name actually matches "sha1" to detect object corruption.
1396 * With "map" == NULL, try reading the object named with "sha1" using
1397 * the streaming interface and rehash it to do the same.
1398 */
1399int check_sha1_signature(const unsigned char *sha1, void *map,
1400 unsigned long size, const char *type)
1401{
1402 unsigned char real_sha1[20];
1403 enum object_type obj_type;
1404 struct git_istream *st;
1405 git_SHA_CTX c;
1406 char hdr[32];
1407 int hdrlen;
1408
1409 if (map) {
1410 hash_sha1_file(map, size, type, real_sha1);
1411 return hashcmp(sha1, real_sha1) ? -1 : 0;
1412 }
1413
1414 st = open_istream(sha1, &obj_type, &size, NULL);
1415 if (!st)
1416 return -1;
1417
1418 /* Generate the header */
1419 hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
1420
1421 /* Sha1.. */
1422 git_SHA1_Init(&c);
1423 git_SHA1_Update(&c, hdr, hdrlen);
1424 for (;;) {
1425 char buf[1024 * 16];
1426 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1427
1428 if (readlen < 0) {
1429 close_istream(st);
1430 return -1;
1431 }
1432 if (!readlen)
1433 break;
1434 git_SHA1_Update(&c, buf, readlen);
1435 }
1436 git_SHA1_Final(real_sha1, &c);
1437 close_istream(st);
1438 return hashcmp(sha1, real_sha1) ? -1 : 0;
1439}
1440
1441int git_open_noatime(const char *name)
1442{
1443 static int sha1_file_open_flag = O_NOATIME;
1444
1445 for (;;) {
1446 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1447 if (fd >= 0)
1448 return fd;
1449
1450 /* Might the failure be due to O_NOATIME? */
1451 if (errno != ENOENT && sha1_file_open_flag) {
1452 sha1_file_open_flag = 0;
1453 continue;
1454 }
1455
1456 return -1;
1457 }
1458}
1459
1460static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1461{
1462 struct alternate_object_database *alt;
1463
1464 if (!lstat(sha1_file_name(sha1), st))
1465 return 0;
1466
1467 prepare_alt_odb();
1468 errno = ENOENT;
1469 for (alt = alt_odb_list; alt; alt = alt->next) {
1470 fill_sha1_path(alt->name, sha1);
1471 if (!lstat(alt->base, st))
1472 return 0;
1473 }
1474
1475 return -1;
1476}
1477
1478static int open_sha1_file(const unsigned char *sha1)
1479{
1480 int fd;
1481 struct alternate_object_database *alt;
1482 int most_interesting_errno;
1483
1484 fd = git_open_noatime(sha1_file_name(sha1));
1485 if (fd >= 0)
1486 return fd;
1487 most_interesting_errno = errno;
1488
1489 prepare_alt_odb();
1490 for (alt = alt_odb_list; alt; alt = alt->next) {
1491 fill_sha1_path(alt->name, sha1);
1492 fd = git_open_noatime(alt->base);
1493 if (fd >= 0)
1494 return fd;
1495 if (most_interesting_errno == ENOENT)
1496 most_interesting_errno = errno;
1497 }
1498 errno = most_interesting_errno;
1499 return -1;
1500}
1501
1502void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1503{
1504 void *map;
1505 int fd;
1506
1507 fd = open_sha1_file(sha1);
1508 map = NULL;
1509 if (fd >= 0) {
1510 struct stat st;
1511
1512 if (!fstat(fd, &st)) {
1513 *size = xsize_t(st.st_size);
1514 if (!*size) {
1515 /* mmap() is forbidden on empty files */
1516 error("object file %s is empty", sha1_file_name(sha1));
1517 return NULL;
1518 }
1519 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1520 }
1521 close(fd);
1522 }
1523 return map;
1524}
1525
1526unsigned long unpack_object_header_buffer(const unsigned char *buf,
1527 unsigned long len, enum object_type *type, unsigned long *sizep)
1528{
1529 unsigned shift;
1530 unsigned long size, c;
1531 unsigned long used = 0;
1532
1533 c = buf[used++];
1534 *type = (c >> 4) & 7;
1535 size = c & 15;
1536 shift = 4;
1537 while (c & 0x80) {
1538 if (len <= used || bitsizeof(long) <= shift) {
1539 error("bad object header");
1540 size = used = 0;
1541 break;
1542 }
1543 c = buf[used++];
1544 size += (c & 0x7f) << shift;
1545 shift += 7;
1546 }
1547 *sizep = size;
1548 return used;
1549}
1550
1551int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1552{
1553 /* Get the data stream */
1554 memset(stream, 0, sizeof(*stream));
1555 stream->next_in = map;
1556 stream->avail_in = mapsize;
1557 stream->next_out = buffer;
1558 stream->avail_out = bufsiz;
1559
1560 git_inflate_init(stream);
1561 return git_inflate(stream, 0);
1562}
1563
1564static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1565{
1566 int bytes = strlen(buffer) + 1;
1567 unsigned char *buf = xmallocz(size);
1568 unsigned long n;
1569 int status = Z_OK;
1570
1571 n = stream->total_out - bytes;
1572 if (n > size)
1573 n = size;
1574 memcpy(buf, (char *) buffer + bytes, n);
1575 bytes = n;
1576 if (bytes <= size) {
1577 /*
1578 * The above condition must be (bytes <= size), not
1579 * (bytes < size). In other words, even though we
1580 * expect no more output and set avail_out to zero,
1581 * the input zlib stream may have bytes that express
1582 * "this concludes the stream", and we *do* want to
1583 * eat that input.
1584 *
1585 * Otherwise we would not be able to test that we
1586 * consumed all the input to reach the expected size;
1587 * we also want to check that zlib tells us that all
1588 * went well with status == Z_STREAM_END at the end.
1589 */
1590 stream->next_out = buf + bytes;
1591 stream->avail_out = size - bytes;
1592 while (status == Z_OK)
1593 status = git_inflate(stream, Z_FINISH);
1594 }
1595 if (status == Z_STREAM_END && !stream->avail_in) {
1596 git_inflate_end(stream);
1597 return buf;
1598 }
1599
1600 if (status < 0)
1601 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1602 else if (stream->avail_in)
1603 error("garbage at end of loose object '%s'",
1604 sha1_to_hex(sha1));
1605 free(buf);
1606 return NULL;
1607}
1608
1609/*
1610 * We used to just use "sscanf()", but that's actually way
1611 * too permissive for what we want to check. So do an anal
1612 * object header parse by hand.
1613 */
1614int parse_sha1_header(const char *hdr, unsigned long *sizep)
1615{
1616 char type[10];
1617 int i;
1618 unsigned long size;
1619
1620 /*
1621 * The type can be at most ten bytes (including the
1622 * terminating '\0' that we add), and is followed by
1623 * a space.
1624 */
1625 i = 0;
1626 for (;;) {
1627 char c = *hdr++;
1628 if (c == ' ')
1629 break;
1630 type[i++] = c;
1631 if (i >= sizeof(type))
1632 return -1;
1633 }
1634 type[i] = 0;
1635
1636 /*
1637 * The length must follow immediately, and be in canonical
1638 * decimal format (ie "010" is not valid).
1639 */
1640 size = *hdr++ - '0';
1641 if (size > 9)
1642 return -1;
1643 if (size) {
1644 for (;;) {
1645 unsigned long c = *hdr - '0';
1646 if (c > 9)
1647 break;
1648 hdr++;
1649 size = size * 10 + c;
1650 }
1651 }
1652 *sizep = size;
1653
1654 /*
1655 * The length must be followed by a zero byte
1656 */
1657 return *hdr ? -1 : type_from_string(type);
1658}
1659
1660static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1661{
1662 int ret;
1663 git_zstream stream;
1664 char hdr[8192];
1665
1666 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1667 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1668 return NULL;
1669
1670 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1671}
1672
1673unsigned long get_size_from_delta(struct packed_git *p,
1674 struct pack_window **w_curs,
1675 off_t curpos)
1676{
1677 const unsigned char *data;
1678 unsigned char delta_head[20], *in;
1679 git_zstream stream;
1680 int st;
1681
1682 memset(&stream, 0, sizeof(stream));
1683 stream.next_out = delta_head;
1684 stream.avail_out = sizeof(delta_head);
1685
1686 git_inflate_init(&stream);
1687 do {
1688 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1689 stream.next_in = in;
1690 st = git_inflate(&stream, Z_FINISH);
1691 curpos += stream.next_in - in;
1692 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1693 stream.total_out < sizeof(delta_head));
1694 git_inflate_end(&stream);
1695 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1696 error("delta data unpack-initial failed");
1697 return 0;
1698 }
1699
1700 /* Examine the initial part of the delta to figure out
1701 * the result size.
1702 */
1703 data = delta_head;
1704
1705 /* ignore base size */
1706 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1707
1708 /* Read the result size */
1709 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1710}
1711
1712static off_t get_delta_base(struct packed_git *p,
1713 struct pack_window **w_curs,
1714 off_t *curpos,
1715 enum object_type type,
1716 off_t delta_obj_offset)
1717{
1718 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1719 off_t base_offset;
1720
1721 /* use_pack() assured us we have [base_info, base_info + 20)
1722 * as a range that we can look at without walking off the
1723 * end of the mapped window. Its actually the hash size
1724 * that is assured. An OFS_DELTA longer than the hash size
1725 * is stupid, as then a REF_DELTA would be smaller to store.
1726 */
1727 if (type == OBJ_OFS_DELTA) {
1728 unsigned used = 0;
1729 unsigned char c = base_info[used++];
1730 base_offset = c & 127;
1731 while (c & 128) {
1732 base_offset += 1;
1733 if (!base_offset || MSB(base_offset, 7))
1734 return 0; /* overflow */
1735 c = base_info[used++];
1736 base_offset = (base_offset << 7) + (c & 127);
1737 }
1738 base_offset = delta_obj_offset - base_offset;
1739 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1740 return 0; /* out of bound */
1741 *curpos += used;
1742 } else if (type == OBJ_REF_DELTA) {
1743 /* The base entry _must_ be in the same pack */
1744 base_offset = find_pack_entry_one(base_info, p);
1745 *curpos += 20;
1746 } else
1747 die("I am totally screwed");
1748 return base_offset;
1749}
1750
1751/*
1752 * Like get_delta_base above, but we return the sha1 instead of the pack
1753 * offset. This means it is cheaper for REF deltas (we do not have to do
1754 * the final object lookup), but more expensive for OFS deltas (we
1755 * have to load the revidx to convert the offset back into a sha1).
1756 */
1757static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1758 struct pack_window **w_curs,
1759 off_t curpos,
1760 enum object_type type,
1761 off_t delta_obj_offset)
1762{
1763 if (type == OBJ_REF_DELTA) {
1764 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1765 return base;
1766 } else if (type == OBJ_OFS_DELTA) {
1767 struct revindex_entry *revidx;
1768 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1769 type, delta_obj_offset);
1770
1771 if (!base_offset)
1772 return NULL;
1773
1774 revidx = find_pack_revindex(p, base_offset);
1775 if (!revidx)
1776 return NULL;
1777
1778 return nth_packed_object_sha1(p, revidx->nr);
1779 } else
1780 return NULL;
1781}
1782
1783int unpack_object_header(struct packed_git *p,
1784 struct pack_window **w_curs,
1785 off_t *curpos,
1786 unsigned long *sizep)
1787{
1788 unsigned char *base;
1789 unsigned long left;
1790 unsigned long used;
1791 enum object_type type;
1792
1793 /* use_pack() assures us we have [base, base + 20) available
1794 * as a range that we can look at. (Its actually the hash
1795 * size that is assured.) With our object header encoding
1796 * the maximum deflated object size is 2^137, which is just
1797 * insane, so we know won't exceed what we have been given.
1798 */
1799 base = use_pack(p, w_curs, *curpos, &left);
1800 used = unpack_object_header_buffer(base, left, &type, sizep);
1801 if (!used) {
1802 type = OBJ_BAD;
1803 } else
1804 *curpos += used;
1805
1806 return type;
1807}
1808
1809static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1810{
1811 int type;
1812 struct revindex_entry *revidx;
1813 const unsigned char *sha1;
1814 revidx = find_pack_revindex(p, obj_offset);
1815 if (!revidx)
1816 return OBJ_BAD;
1817 sha1 = nth_packed_object_sha1(p, revidx->nr);
1818 mark_bad_packed_object(p, sha1);
1819 type = sha1_object_info(sha1, NULL);
1820 if (type <= OBJ_NONE)
1821 return OBJ_BAD;
1822 return type;
1823}
1824
1825#define POI_STACK_PREALLOC 64
1826
1827static enum object_type packed_to_object_type(struct packed_git *p,
1828 off_t obj_offset,
1829 enum object_type type,
1830 struct pack_window **w_curs,
1831 off_t curpos)
1832{
1833 off_t small_poi_stack[POI_STACK_PREALLOC];
1834 off_t *poi_stack = small_poi_stack;
1835 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1836
1837 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1838 off_t base_offset;
1839 unsigned long size;
1840 /* Push the object we're going to leave behind */
1841 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1842 poi_stack_alloc = alloc_nr(poi_stack_nr);
1843 poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
1844 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1845 } else {
1846 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1847 }
1848 poi_stack[poi_stack_nr++] = obj_offset;
1849 /* If parsing the base offset fails, just unwind */
1850 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1851 if (!base_offset)
1852 goto unwind;
1853 curpos = obj_offset = base_offset;
1854 type = unpack_object_header(p, w_curs, &curpos, &size);
1855 if (type <= OBJ_NONE) {
1856 /* If getting the base itself fails, we first
1857 * retry the base, otherwise unwind */
1858 type = retry_bad_packed_offset(p, base_offset);
1859 if (type > OBJ_NONE)
1860 goto out;
1861 goto unwind;
1862 }
1863 }
1864
1865 switch (type) {
1866 case OBJ_BAD:
1867 case OBJ_COMMIT:
1868 case OBJ_TREE:
1869 case OBJ_BLOB:
1870 case OBJ_TAG:
1871 break;
1872 default:
1873 error("unknown object type %i at offset %"PRIuMAX" in %s",
1874 type, (uintmax_t)obj_offset, p->pack_name);
1875 type = OBJ_BAD;
1876 }
1877
1878out:
1879 if (poi_stack != small_poi_stack)
1880 free(poi_stack);
1881 return type;
1882
1883unwind:
1884 while (poi_stack_nr) {
1885 obj_offset = poi_stack[--poi_stack_nr];
1886 type = retry_bad_packed_offset(p, obj_offset);
1887 if (type > OBJ_NONE)
1888 goto out;
1889 }
1890 type = OBJ_BAD;
1891 goto out;
1892}
1893
1894static int packed_object_info(struct packed_git *p, off_t obj_offset,
1895 struct object_info *oi)
1896{
1897 struct pack_window *w_curs = NULL;
1898 unsigned long size;
1899 off_t curpos = obj_offset;
1900 enum object_type type;
1901
1902 /*
1903 * We always get the representation type, but only convert it to
1904 * a "real" type later if the caller is interested.
1905 */
1906 type = unpack_object_header(p, &w_curs, &curpos, &size);
1907
1908 if (oi->sizep) {
1909 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1910 off_t tmp_pos = curpos;
1911 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1912 type, obj_offset);
1913 if (!base_offset) {
1914 type = OBJ_BAD;
1915 goto out;
1916 }
1917 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1918 if (*oi->sizep == 0) {
1919 type = OBJ_BAD;
1920 goto out;
1921 }
1922 } else {
1923 *oi->sizep = size;
1924 }
1925 }
1926
1927 if (oi->disk_sizep) {
1928 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1929 *oi->disk_sizep = revidx[1].offset - obj_offset;
1930 }
1931
1932 if (oi->typep) {
1933 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
1934 if (*oi->typep < 0) {
1935 type = OBJ_BAD;
1936 goto out;
1937 }
1938 }
1939
1940 if (oi->delta_base_sha1) {
1941 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1942 const unsigned char *base;
1943
1944 base = get_delta_base_sha1(p, &w_curs, curpos,
1945 type, obj_offset);
1946 if (!base) {
1947 type = OBJ_BAD;
1948 goto out;
1949 }
1950
1951 hashcpy(oi->delta_base_sha1, base);
1952 } else
1953 hashclr(oi->delta_base_sha1);
1954 }
1955
1956out:
1957 unuse_pack(&w_curs);
1958 return type;
1959}
1960
1961static void *unpack_compressed_entry(struct packed_git *p,
1962 struct pack_window **w_curs,
1963 off_t curpos,
1964 unsigned long size)
1965{
1966 int st;
1967 git_zstream stream;
1968 unsigned char *buffer, *in;
1969
1970 buffer = xmallocz_gently(size);
1971 if (!buffer)
1972 return NULL;
1973 memset(&stream, 0, sizeof(stream));
1974 stream.next_out = buffer;
1975 stream.avail_out = size + 1;
1976
1977 git_inflate_init(&stream);
1978 do {
1979 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1980 stream.next_in = in;
1981 st = git_inflate(&stream, Z_FINISH);
1982 if (!stream.avail_out)
1983 break; /* the payload is larger than it should be */
1984 curpos += stream.next_in - in;
1985 } while (st == Z_OK || st == Z_BUF_ERROR);
1986 git_inflate_end(&stream);
1987 if ((st != Z_STREAM_END) || stream.total_out != size) {
1988 free(buffer);
1989 return NULL;
1990 }
1991
1992 return buffer;
1993}
1994
1995#define MAX_DELTA_CACHE (256)
1996
1997static size_t delta_base_cached;
1998
1999static struct delta_base_cache_lru_list {
2000 struct delta_base_cache_lru_list *prev;
2001 struct delta_base_cache_lru_list *next;
2002} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
2003
2004static struct delta_base_cache_entry {
2005 struct delta_base_cache_lru_list lru;
2006 void *data;
2007 struct packed_git *p;
2008 off_t base_offset;
2009 unsigned long size;
2010 enum object_type type;
2011} delta_base_cache[MAX_DELTA_CACHE];
2012
2013static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
2014{
2015 unsigned long hash;
2016
2017 hash = (unsigned long)p + (unsigned long)base_offset;
2018 hash += (hash >> 8) + (hash >> 16);
2019 return hash % MAX_DELTA_CACHE;
2020}
2021
2022static struct delta_base_cache_entry *
2023get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
2024{
2025 unsigned long hash = pack_entry_hash(p, base_offset);
2026 return delta_base_cache + hash;
2027}
2028
2029static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
2030 struct packed_git *p, off_t base_offset)
2031{
2032 return (ent->data && ent->p == p && ent->base_offset == base_offset);
2033}
2034
2035static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
2036{
2037 struct delta_base_cache_entry *ent;
2038 ent = get_delta_base_cache_entry(p, base_offset);
2039 return eq_delta_base_cache_entry(ent, p, base_offset);
2040}
2041
2042static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
2043{
2044 ent->data = NULL;
2045 ent->lru.next->prev = ent->lru.prev;
2046 ent->lru.prev->next = ent->lru.next;
2047 delta_base_cached -= ent->size;
2048}
2049
2050static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
2051 unsigned long *base_size, enum object_type *type, int keep_cache)
2052{
2053 struct delta_base_cache_entry *ent;
2054 void *ret;
2055
2056 ent = get_delta_base_cache_entry(p, base_offset);
2057
2058 if (!eq_delta_base_cache_entry(ent, p, base_offset))
2059 return unpack_entry(p, base_offset, type, base_size);
2060
2061 ret = ent->data;
2062
2063 if (!keep_cache)
2064 clear_delta_base_cache_entry(ent);
2065 else
2066 ret = xmemdupz(ent->data, ent->size);
2067 *type = ent->type;
2068 *base_size = ent->size;
2069 return ret;
2070}
2071
2072static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2073{
2074 if (ent->data) {
2075 free(ent->data);
2076 ent->data = NULL;
2077 ent->lru.next->prev = ent->lru.prev;
2078 ent->lru.prev->next = ent->lru.next;
2079 delta_base_cached -= ent->size;
2080 }
2081}
2082
2083void clear_delta_base_cache(void)
2084{
2085 unsigned long p;
2086 for (p = 0; p < MAX_DELTA_CACHE; p++)
2087 release_delta_base_cache(&delta_base_cache[p]);
2088}
2089
2090static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2091 void *base, unsigned long base_size, enum object_type type)
2092{
2093 unsigned long hash = pack_entry_hash(p, base_offset);
2094 struct delta_base_cache_entry *ent = delta_base_cache + hash;
2095 struct delta_base_cache_lru_list *lru;
2096
2097 release_delta_base_cache(ent);
2098 delta_base_cached += base_size;
2099
2100 for (lru = delta_base_cache_lru.next;
2101 delta_base_cached > delta_base_cache_limit
2102 && lru != &delta_base_cache_lru;
2103 lru = lru->next) {
2104 struct delta_base_cache_entry *f = (void *)lru;
2105 if (f->type == OBJ_BLOB)
2106 release_delta_base_cache(f);
2107 }
2108 for (lru = delta_base_cache_lru.next;
2109 delta_base_cached > delta_base_cache_limit
2110 && lru != &delta_base_cache_lru;
2111 lru = lru->next) {
2112 struct delta_base_cache_entry *f = (void *)lru;
2113 release_delta_base_cache(f);
2114 }
2115
2116 ent->p = p;
2117 ent->base_offset = base_offset;
2118 ent->type = type;
2119 ent->data = base;
2120 ent->size = base_size;
2121 ent->lru.next = &delta_base_cache_lru;
2122 ent->lru.prev = delta_base_cache_lru.prev;
2123 delta_base_cache_lru.prev->next = &ent->lru;
2124 delta_base_cache_lru.prev = &ent->lru;
2125}
2126
2127static void *read_object(const unsigned char *sha1, enum object_type *type,
2128 unsigned long *size);
2129
2130static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2131{
2132 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
2133 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
2134 p->pack_name, (uintmax_t)obj_offset);
2135}
2136
2137int do_check_packed_object_crc;
2138
2139#define UNPACK_ENTRY_STACK_PREALLOC 64
2140struct unpack_entry_stack_ent {
2141 off_t obj_offset;
2142 off_t curpos;
2143 unsigned long size;
2144};
2145
2146void *unpack_entry(struct packed_git *p, off_t obj_offset,
2147 enum object_type *final_type, unsigned long *final_size)
2148{
2149 struct pack_window *w_curs = NULL;
2150 off_t curpos = obj_offset;
2151 void *data = NULL;
2152 unsigned long size;
2153 enum object_type type;
2154 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2155 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2156 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2157 int base_from_cache = 0;
2158
2159 write_pack_access_log(p, obj_offset);
2160
2161 /* PHASE 1: drill down to the innermost base object */
2162 for (;;) {
2163 off_t base_offset;
2164 int i;
2165 struct delta_base_cache_entry *ent;
2166
2167 ent = get_delta_base_cache_entry(p, curpos);
2168 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2169 type = ent->type;
2170 data = ent->data;
2171 size = ent->size;
2172 clear_delta_base_cache_entry(ent);
2173 base_from_cache = 1;
2174 break;
2175 }
2176
2177 if (do_check_packed_object_crc && p->index_version > 1) {
2178 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2179 unsigned long len = revidx[1].offset - obj_offset;
2180 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2181 const unsigned char *sha1 =
2182 nth_packed_object_sha1(p, revidx->nr);
2183 error("bad packed object CRC for %s",
2184 sha1_to_hex(sha1));
2185 mark_bad_packed_object(p, sha1);
2186 unuse_pack(&w_curs);
2187 return NULL;
2188 }
2189 }
2190
2191 type = unpack_object_header(p, &w_curs, &curpos, &size);
2192 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2193 break;
2194
2195 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2196 if (!base_offset) {
2197 error("failed to validate delta base reference "
2198 "at offset %"PRIuMAX" from %s",
2199 (uintmax_t)curpos, p->pack_name);
2200 /* bail to phase 2, in hopes of recovery */
2201 data = NULL;
2202 break;
2203 }
2204
2205 /* push object, proceed to base */
2206 if (delta_stack_nr >= delta_stack_alloc
2207 && delta_stack == small_delta_stack) {
2208 delta_stack_alloc = alloc_nr(delta_stack_nr);
2209 delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
2210 memcpy(delta_stack, small_delta_stack,
2211 sizeof(*delta_stack)*delta_stack_nr);
2212 } else {
2213 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2214 }
2215 i = delta_stack_nr++;
2216 delta_stack[i].obj_offset = obj_offset;
2217 delta_stack[i].curpos = curpos;
2218 delta_stack[i].size = size;
2219
2220 curpos = obj_offset = base_offset;
2221 }
2222
2223 /* PHASE 2: handle the base */
2224 switch (type) {
2225 case OBJ_OFS_DELTA:
2226 case OBJ_REF_DELTA:
2227 if (data)
2228 die("BUG in unpack_entry: left loop at a valid delta");
2229 break;
2230 case OBJ_COMMIT:
2231 case OBJ_TREE:
2232 case OBJ_BLOB:
2233 case OBJ_TAG:
2234 if (!base_from_cache)
2235 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2236 break;
2237 default:
2238 data = NULL;
2239 error("unknown object type %i at offset %"PRIuMAX" in %s",
2240 type, (uintmax_t)obj_offset, p->pack_name);
2241 }
2242
2243 /* PHASE 3: apply deltas in order */
2244
2245 /* invariants:
2246 * 'data' holds the base data, or NULL if there was corruption
2247 */
2248 while (delta_stack_nr) {
2249 void *delta_data;
2250 void *base = data;
2251 unsigned long delta_size, base_size = size;
2252 int i;
2253
2254 data = NULL;
2255
2256 if (base)
2257 add_delta_base_cache(p, obj_offset, base, base_size, type);
2258
2259 if (!base) {
2260 /*
2261 * We're probably in deep shit, but let's try to fetch
2262 * the required base anyway from another pack or loose.
2263 * This is costly but should happen only in the presence
2264 * of a corrupted pack, and is better than failing outright.
2265 */
2266 struct revindex_entry *revidx;
2267 const unsigned char *base_sha1;
2268 revidx = find_pack_revindex(p, obj_offset);
2269 if (revidx) {
2270 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2271 error("failed to read delta base object %s"
2272 " at offset %"PRIuMAX" from %s",
2273 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2274 p->pack_name);
2275 mark_bad_packed_object(p, base_sha1);
2276 base = read_object(base_sha1, &type, &base_size);
2277 }
2278 }
2279
2280 i = --delta_stack_nr;
2281 obj_offset = delta_stack[i].obj_offset;
2282 curpos = delta_stack[i].curpos;
2283 delta_size = delta_stack[i].size;
2284
2285 if (!base)
2286 continue;
2287
2288 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2289
2290 if (!delta_data) {
2291 error("failed to unpack compressed delta "
2292 "at offset %"PRIuMAX" from %s",
2293 (uintmax_t)curpos, p->pack_name);
2294 data = NULL;
2295 continue;
2296 }
2297
2298 data = patch_delta(base, base_size,
2299 delta_data, delta_size,
2300 &size);
2301
2302 /*
2303 * We could not apply the delta; warn the user, but keep going.
2304 * Our failure will be noticed either in the next iteration of
2305 * the loop, or if this is the final delta, in the caller when
2306 * we return NULL. Those code paths will take care of making
2307 * a more explicit warning and retrying with another copy of
2308 * the object.
2309 */
2310 if (!data)
2311 error("failed to apply delta");
2312
2313 free(delta_data);
2314 }
2315
2316 *final_type = type;
2317 *final_size = size;
2318
2319 unuse_pack(&w_curs);
2320
2321 if (delta_stack != small_delta_stack)
2322 free(delta_stack);
2323
2324 return data;
2325}
2326
2327const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2328 uint32_t n)
2329{
2330 const unsigned char *index = p->index_data;
2331 if (!index) {
2332 if (open_pack_index(p))
2333 return NULL;
2334 index = p->index_data;
2335 }
2336 if (n >= p->num_objects)
2337 return NULL;
2338 index += 4 * 256;
2339 if (p->index_version == 1) {
2340 return index + 24 * n + 4;
2341 } else {
2342 index += 8;
2343 return index + 20 * n;
2344 }
2345}
2346
2347off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2348{
2349 const unsigned char *index = p->index_data;
2350 index += 4 * 256;
2351 if (p->index_version == 1) {
2352 return ntohl(*((uint32_t *)(index + 24 * n)));
2353 } else {
2354 uint32_t off;
2355 index += 8 + p->num_objects * (20 + 4);
2356 off = ntohl(*((uint32_t *)(index + 4 * n)));
2357 if (!(off & 0x80000000))
2358 return off;
2359 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2360 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2361 ntohl(*((uint32_t *)(index + 4)));
2362 }
2363}
2364
2365off_t find_pack_entry_one(const unsigned char *sha1,
2366 struct packed_git *p)
2367{
2368 const uint32_t *level1_ofs = p->index_data;
2369 const unsigned char *index = p->index_data;
2370 unsigned hi, lo, stride;
2371 static int use_lookup = -1;
2372 static int debug_lookup = -1;
2373
2374 if (debug_lookup < 0)
2375 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2376
2377 if (!index) {
2378 if (open_pack_index(p))
2379 return 0;
2380 level1_ofs = p->index_data;
2381 index = p->index_data;
2382 }
2383 if (p->index_version > 1) {
2384 level1_ofs += 2;
2385 index += 8;
2386 }
2387 index += 4 * 256;
2388 hi = ntohl(level1_ofs[*sha1]);
2389 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2390 if (p->index_version > 1) {
2391 stride = 20;
2392 } else {
2393 stride = 24;
2394 index += 4;
2395 }
2396
2397 if (debug_lookup)
2398 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2399 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2400
2401 if (use_lookup < 0)
2402 use_lookup = !!getenv("GIT_USE_LOOKUP");
2403 if (use_lookup) {
2404 int pos = sha1_entry_pos(index, stride, 0,
2405 lo, hi, p->num_objects, sha1);
2406 if (pos < 0)
2407 return 0;
2408 return nth_packed_object_offset(p, pos);
2409 }
2410
2411 do {
2412 unsigned mi = (lo + hi) / 2;
2413 int cmp = hashcmp(index + mi * stride, sha1);
2414
2415 if (debug_lookup)
2416 printf("lo %u hi %u rg %u mi %u\n",
2417 lo, hi, hi - lo, mi);
2418 if (!cmp)
2419 return nth_packed_object_offset(p, mi);
2420 if (cmp > 0)
2421 hi = mi;
2422 else
2423 lo = mi+1;
2424 } while (lo < hi);
2425 return 0;
2426}
2427
2428int is_pack_valid(struct packed_git *p)
2429{
2430 /* An already open pack is known to be valid. */
2431 if (p->pack_fd != -1)
2432 return 1;
2433
2434 /* If the pack has one window completely covering the
2435 * file size, the pack is known to be valid even if
2436 * the descriptor is not currently open.
2437 */
2438 if (p->windows) {
2439 struct pack_window *w = p->windows;
2440
2441 if (!w->offset && w->len == p->pack_size)
2442 return 1;
2443 }
2444
2445 /* Force the pack to open to prove its valid. */
2446 return !open_packed_git(p);
2447}
2448
2449static int fill_pack_entry(const unsigned char *sha1,
2450 struct pack_entry *e,
2451 struct packed_git *p)
2452{
2453 off_t offset;
2454
2455 if (p->num_bad_objects) {
2456 unsigned i;
2457 for (i = 0; i < p->num_bad_objects; i++)
2458 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2459 return 0;
2460 }
2461
2462 offset = find_pack_entry_one(sha1, p);
2463 if (!offset)
2464 return 0;
2465
2466 /*
2467 * We are about to tell the caller where they can locate the
2468 * requested object. We better make sure the packfile is
2469 * still here and can be accessed before supplying that
2470 * answer, as it may have been deleted since the index was
2471 * loaded!
2472 */
2473 if (!is_pack_valid(p)) {
2474 warning("packfile %s cannot be accessed", p->pack_name);
2475 return 0;
2476 }
2477 e->offset = offset;
2478 e->p = p;
2479 hashcpy(e->sha1, sha1);
2480 return 1;
2481}
2482
2483/*
2484 * Iff a pack file contains the object named by sha1, return true and
2485 * store its location to e.
2486 */
2487static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2488{
2489 struct packed_git *p;
2490
2491 prepare_packed_git();
2492 if (!packed_git)
2493 return 0;
2494
2495 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2496 return 1;
2497
2498 for (p = packed_git; p; p = p->next) {
2499 if (p == last_found_pack)
2500 continue; /* we already checked this one */
2501
2502 if (fill_pack_entry(sha1, e, p)) {
2503 last_found_pack = p;
2504 return 1;
2505 }
2506 }
2507 return 0;
2508}
2509
2510struct packed_git *find_sha1_pack(const unsigned char *sha1,
2511 struct packed_git *packs)
2512{
2513 struct packed_git *p;
2514
2515 for (p = packs; p; p = p->next) {
2516 if (find_pack_entry_one(sha1, p))
2517 return p;
2518 }
2519 return NULL;
2520
2521}
2522
2523static int sha1_loose_object_info(const unsigned char *sha1,
2524 struct object_info *oi)
2525{
2526 int status;
2527 unsigned long mapsize, size;
2528 void *map;
2529 git_zstream stream;
2530 char hdr[32];
2531
2532 if (oi->delta_base_sha1)
2533 hashclr(oi->delta_base_sha1);
2534
2535 /*
2536 * If we don't care about type or size, then we don't
2537 * need to look inside the object at all. Note that we
2538 * do not optimize out the stat call, even if the
2539 * caller doesn't care about the disk-size, since our
2540 * return value implicitly indicates whether the
2541 * object even exists.
2542 */
2543 if (!oi->typep && !oi->sizep) {
2544 struct stat st;
2545 if (stat_sha1_file(sha1, &st) < 0)
2546 return -1;
2547 if (oi->disk_sizep)
2548 *oi->disk_sizep = st.st_size;
2549 return 0;
2550 }
2551
2552 map = map_sha1_file(sha1, &mapsize);
2553 if (!map)
2554 return -1;
2555 if (oi->disk_sizep)
2556 *oi->disk_sizep = mapsize;
2557 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2558 status = error("unable to unpack %s header",
2559 sha1_to_hex(sha1));
2560 else if ((status = parse_sha1_header(hdr, &size)) < 0)
2561 status = error("unable to parse %s header", sha1_to_hex(sha1));
2562 else if (oi->sizep)
2563 *oi->sizep = size;
2564 git_inflate_end(&stream);
2565 munmap(map, mapsize);
2566 if (oi->typep)
2567 *oi->typep = status;
2568 return 0;
2569}
2570
2571int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
2572{
2573 struct cached_object *co;
2574 struct pack_entry e;
2575 int rtype;
2576 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
2577
2578 co = find_cached_object(real);
2579 if (co) {
2580 if (oi->typep)
2581 *(oi->typep) = co->type;
2582 if (oi->sizep)
2583 *(oi->sizep) = co->size;
2584 if (oi->disk_sizep)
2585 *(oi->disk_sizep) = 0;
2586 if (oi->delta_base_sha1)
2587 hashclr(oi->delta_base_sha1);
2588 oi->whence = OI_CACHED;
2589 return 0;
2590 }
2591
2592 if (!find_pack_entry(real, &e)) {
2593 /* Most likely it's a loose object. */
2594 if (!sha1_loose_object_info(real, oi)) {
2595 oi->whence = OI_LOOSE;
2596 return 0;
2597 }
2598
2599 /* Not a loose object; someone else may have just packed it. */
2600 reprepare_packed_git();
2601 if (!find_pack_entry(real, &e))
2602 return -1;
2603 }
2604
2605 rtype = packed_object_info(e.p, e.offset, oi);
2606 if (rtype < 0) {
2607 mark_bad_packed_object(e.p, real);
2608 return sha1_object_info_extended(real, oi, 0);
2609 } else if (in_delta_base_cache(e.p, e.offset)) {
2610 oi->whence = OI_DBCACHED;
2611 } else {
2612 oi->whence = OI_PACKED;
2613 oi->u.packed.offset = e.offset;
2614 oi->u.packed.pack = e.p;
2615 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2616 rtype == OBJ_OFS_DELTA);
2617 }
2618
2619 return 0;
2620}
2621
2622/* returns enum object_type or negative */
2623int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2624{
2625 enum object_type type;
2626 struct object_info oi = {NULL};
2627
2628 oi.typep = &type;
2629 oi.sizep = sizep;
2630 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
2631 return -1;
2632 return type;
2633}
2634
2635static void *read_packed_sha1(const unsigned char *sha1,
2636 enum object_type *type, unsigned long *size)
2637{
2638 struct pack_entry e;
2639 void *data;
2640
2641 if (!find_pack_entry(sha1, &e))
2642 return NULL;
2643 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2644 if (!data) {
2645 /*
2646 * We're probably in deep shit, but let's try to fetch
2647 * the required object anyway from another pack or loose.
2648 * This should happen only in the presence of a corrupted
2649 * pack, and is better than failing outright.
2650 */
2651 error("failed to read object %s at offset %"PRIuMAX" from %s",
2652 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2653 mark_bad_packed_object(e.p, sha1);
2654 data = read_object(sha1, type, size);
2655 }
2656 return data;
2657}
2658
2659int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2660 unsigned char *sha1)
2661{
2662 struct cached_object *co;
2663
2664 hash_sha1_file(buf, len, typename(type), sha1);
2665 if (has_sha1_file(sha1) || find_cached_object(sha1))
2666 return 0;
2667 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
2668 co = &cached_objects[cached_object_nr++];
2669 co->size = len;
2670 co->type = type;
2671 co->buf = xmalloc(len);
2672 memcpy(co->buf, buf, len);
2673 hashcpy(co->sha1, sha1);
2674 return 0;
2675}
2676
2677static void *read_object(const unsigned char *sha1, enum object_type *type,
2678 unsigned long *size)
2679{
2680 unsigned long mapsize;
2681 void *map, *buf;
2682 struct cached_object *co;
2683
2684 co = find_cached_object(sha1);
2685 if (co) {
2686 *type = co->type;
2687 *size = co->size;
2688 return xmemdupz(co->buf, co->size);
2689 }
2690
2691 buf = read_packed_sha1(sha1, type, size);
2692 if (buf)
2693 return buf;
2694 map = map_sha1_file(sha1, &mapsize);
2695 if (map) {
2696 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2697 munmap(map, mapsize);
2698 return buf;
2699 }
2700 reprepare_packed_git();
2701 return read_packed_sha1(sha1, type, size);
2702}
2703
2704/*
2705 * This function dies on corrupt objects; the callers who want to
2706 * deal with them should arrange to call read_object() and give error
2707 * messages themselves.
2708 */
2709void *read_sha1_file_extended(const unsigned char *sha1,
2710 enum object_type *type,
2711 unsigned long *size,
2712 unsigned flag)
2713{
2714 void *data;
2715 const struct packed_git *p;
2716 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
2717
2718 errno = 0;
2719 data = read_object(repl, type, size);
2720 if (data)
2721 return data;
2722
2723 if (errno && errno != ENOENT)
2724 die_errno("failed to read object %s", sha1_to_hex(sha1));
2725
2726 /* die if we replaced an object with one that does not exist */
2727 if (repl != sha1)
2728 die("replacement %s not found for %s",
2729 sha1_to_hex(repl), sha1_to_hex(sha1));
2730
2731 if (has_loose_object(repl)) {
2732 const char *path = sha1_file_name(sha1);
2733
2734 die("loose object %s (stored in %s) is corrupt",
2735 sha1_to_hex(repl), path);
2736 }
2737
2738 if ((p = has_packed_and_bad(repl)) != NULL)
2739 die("packed object %s (stored in %s) is corrupt",
2740 sha1_to_hex(repl), p->pack_name);
2741
2742 return NULL;
2743}
2744
2745void *read_object_with_reference(const unsigned char *sha1,
2746 const char *required_type_name,
2747 unsigned long *size,
2748 unsigned char *actual_sha1_return)
2749{
2750 enum object_type type, required_type;
2751 void *buffer;
2752 unsigned long isize;
2753 unsigned char actual_sha1[20];
2754
2755 required_type = type_from_string(required_type_name);
2756 hashcpy(actual_sha1, sha1);
2757 while (1) {
2758 int ref_length = -1;
2759 const char *ref_type = NULL;
2760
2761 buffer = read_sha1_file(actual_sha1, &type, &isize);
2762 if (!buffer)
2763 return NULL;
2764 if (type == required_type) {
2765 *size = isize;
2766 if (actual_sha1_return)
2767 hashcpy(actual_sha1_return, actual_sha1);
2768 return buffer;
2769 }
2770 /* Handle references */
2771 else if (type == OBJ_COMMIT)
2772 ref_type = "tree ";
2773 else if (type == OBJ_TAG)
2774 ref_type = "object ";
2775 else {
2776 free(buffer);
2777 return NULL;
2778 }
2779 ref_length = strlen(ref_type);
2780
2781 if (ref_length + 40 > isize ||
2782 memcmp(buffer, ref_type, ref_length) ||
2783 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2784 free(buffer);
2785 return NULL;
2786 }
2787 free(buffer);
2788 /* Now we have the ID of the referred-to object in
2789 * actual_sha1. Check again. */
2790 }
2791}
2792
2793static void write_sha1_file_prepare(const void *buf, unsigned long len,
2794 const char *type, unsigned char *sha1,
2795 char *hdr, int *hdrlen)
2796{
2797 git_SHA_CTX c;
2798
2799 /* Generate the header */
2800 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2801
2802 /* Sha1.. */
2803 git_SHA1_Init(&c);
2804 git_SHA1_Update(&c, hdr, *hdrlen);
2805 git_SHA1_Update(&c, buf, len);
2806 git_SHA1_Final(sha1, &c);
2807}
2808
2809/*
2810 * Move the just written object into its final resting place.
2811 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2812 * "moving" is only a part of what it does, when no patch between
2813 * master to pu changes the call sites of this function.
2814 */
2815int move_temp_to_file(const char *tmpfile, const char *filename)
2816{
2817 int ret = 0;
2818
2819 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2820 goto try_rename;
2821 else if (link(tmpfile, filename))
2822 ret = errno;
2823
2824 /*
2825 * Coda hack - coda doesn't like cross-directory links,
2826 * so we fall back to a rename, which will mean that it
2827 * won't be able to check collisions, but that's not a
2828 * big deal.
2829 *
2830 * The same holds for FAT formatted media.
2831 *
2832 * When this succeeds, we just return. We have nothing
2833 * left to unlink.
2834 */
2835 if (ret && ret != EEXIST) {
2836 try_rename:
2837 if (!rename(tmpfile, filename))
2838 goto out;
2839 ret = errno;
2840 }
2841 unlink_or_warn(tmpfile);
2842 if (ret) {
2843 if (ret != EEXIST) {
2844 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
2845 }
2846 /* FIXME!!! Collision check here ? */
2847 }
2848
2849out:
2850 if (adjust_shared_perm(filename))
2851 return error("unable to set permission to '%s'", filename);
2852 return 0;
2853}
2854
2855static int write_buffer(int fd, const void *buf, size_t len)
2856{
2857 if (write_in_full(fd, buf, len) < 0)
2858 return error("file write error (%s)", strerror(errno));
2859 return 0;
2860}
2861
2862int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2863 unsigned char *sha1)
2864{
2865 char hdr[32];
2866 int hdrlen;
2867 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2868 return 0;
2869}
2870
2871/* Finalize a file on disk, and close it. */
2872static void close_sha1_file(int fd)
2873{
2874 if (fsync_object_files)
2875 fsync_or_die(fd, "sha1 file");
2876 if (close(fd) != 0)
2877 die_errno("error when closing sha1 file");
2878}
2879
2880/* Size of directory component, including the ending '/' */
2881static inline int directory_size(const char *filename)
2882{
2883 const char *s = strrchr(filename, '/');
2884 if (!s)
2885 return 0;
2886 return s - filename + 1;
2887}
2888
2889/*
2890 * This creates a temporary file in the same directory as the final
2891 * 'filename'
2892 *
2893 * We want to avoid cross-directory filename renames, because those
2894 * can have problems on various filesystems (FAT, NFS, Coda).
2895 */
2896static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2897{
2898 int fd, dirlen = directory_size(filename);
2899
2900 if (dirlen + 20 > bufsiz) {
2901 errno = ENAMETOOLONG;
2902 return -1;
2903 }
2904 memcpy(buffer, filename, dirlen);
2905 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2906 fd = git_mkstemp_mode(buffer, 0444);
2907 if (fd < 0 && dirlen && errno == ENOENT) {
2908 /* Make sure the directory exists */
2909 memcpy(buffer, filename, dirlen);
2910 buffer[dirlen-1] = 0;
2911 if (mkdir(buffer, 0777) && errno != EEXIST)
2912 return -1;
2913 if (adjust_shared_perm(buffer))
2914 return -1;
2915
2916 /* Try again */
2917 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2918 fd = git_mkstemp_mode(buffer, 0444);
2919 }
2920 return fd;
2921}
2922
2923static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2924 const void *buf, unsigned long len, time_t mtime)
2925{
2926 int fd, ret;
2927 unsigned char compressed[4096];
2928 git_zstream stream;
2929 git_SHA_CTX c;
2930 unsigned char parano_sha1[20];
2931 static char tmp_file[PATH_MAX];
2932 const char *filename = sha1_file_name(sha1);
2933
2934 fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
2935 if (fd < 0) {
2936 if (errno == EACCES)
2937 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
2938 else
2939 return error("unable to create temporary file: %s", strerror(errno));
2940 }
2941
2942 /* Set it up */
2943 memset(&stream, 0, sizeof(stream));
2944 git_deflate_init(&stream, zlib_compression_level);
2945 stream.next_out = compressed;
2946 stream.avail_out = sizeof(compressed);
2947 git_SHA1_Init(&c);
2948
2949 /* First header.. */
2950 stream.next_in = (unsigned char *)hdr;
2951 stream.avail_in = hdrlen;
2952 while (git_deflate(&stream, 0) == Z_OK)
2953 ; /* nothing */
2954 git_SHA1_Update(&c, hdr, hdrlen);
2955
2956 /* Then the data itself.. */
2957 stream.next_in = (void *)buf;
2958 stream.avail_in = len;
2959 do {
2960 unsigned char *in0 = stream.next_in;
2961 ret = git_deflate(&stream, Z_FINISH);
2962 git_SHA1_Update(&c, in0, stream.next_in - in0);
2963 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2964 die("unable to write sha1 file");
2965 stream.next_out = compressed;
2966 stream.avail_out = sizeof(compressed);
2967 } while (ret == Z_OK);
2968
2969 if (ret != Z_STREAM_END)
2970 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2971 ret = git_deflate_end_gently(&stream);
2972 if (ret != Z_OK)
2973 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2974 git_SHA1_Final(parano_sha1, &c);
2975 if (hashcmp(sha1, parano_sha1) != 0)
2976 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
2977
2978 close_sha1_file(fd);
2979
2980 if (mtime) {
2981 struct utimbuf utb;
2982 utb.actime = mtime;
2983 utb.modtime = mtime;
2984 if (utime(tmp_file, &utb) < 0)
2985 warning("failed utime() on %s: %s",
2986 tmp_file, strerror(errno));
2987 }
2988
2989 return move_temp_to_file(tmp_file, filename);
2990}
2991
2992static int freshen_loose_object(const unsigned char *sha1)
2993{
2994 return check_and_freshen(sha1, 1);
2995}
2996
2997static int freshen_packed_object(const unsigned char *sha1)
2998{
2999 struct pack_entry e;
3000 return find_pack_entry(sha1, &e) && freshen_file(e.p->pack_name);
3001}
3002
3003int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
3004{
3005 unsigned char sha1[20];
3006 char hdr[32];
3007 int hdrlen;
3008
3009 /* Normally if we have it in the pack then we do not bother writing
3010 * it out into .git/objects/??/?{38} file.
3011 */
3012 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
3013 if (returnsha1)
3014 hashcpy(returnsha1, sha1);
3015 if (freshen_loose_object(sha1) || freshen_packed_object(sha1))
3016 return 0;
3017 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
3018}
3019
3020int force_object_loose(const unsigned char *sha1, time_t mtime)
3021{
3022 void *buf;
3023 unsigned long len;
3024 enum object_type type;
3025 char hdr[32];
3026 int hdrlen;
3027 int ret;
3028
3029 if (has_loose_object(sha1))
3030 return 0;
3031 buf = read_packed_sha1(sha1, &type, &len);
3032 if (!buf)
3033 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
3034 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
3035 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
3036 free(buf);
3037
3038 return ret;
3039}
3040
3041int has_pack_index(const unsigned char *sha1)
3042{
3043 struct stat st;
3044 if (stat(sha1_pack_index_name(sha1), &st))
3045 return 0;
3046 return 1;
3047}
3048
3049int has_sha1_pack(const unsigned char *sha1)
3050{
3051 struct pack_entry e;
3052 return find_pack_entry(sha1, &e);
3053}
3054
3055int has_sha1_file(const unsigned char *sha1)
3056{
3057 struct pack_entry e;
3058
3059 if (find_pack_entry(sha1, &e))
3060 return 1;
3061 if (has_loose_object(sha1))
3062 return 1;
3063 reprepare_packed_git();
3064 return find_pack_entry(sha1, &e);
3065}
3066
3067static void check_tree(const void *buf, size_t size)
3068{
3069 struct tree_desc desc;
3070 struct name_entry entry;
3071
3072 init_tree_desc(&desc, buf, size);
3073 while (tree_entry(&desc, &entry))
3074 /* do nothing
3075 * tree_entry() will die() on malformed entries */
3076 ;
3077}
3078
3079static void check_commit(const void *buf, size_t size)
3080{
3081 struct commit c;
3082 memset(&c, 0, sizeof(c));
3083 if (parse_commit_buffer(&c, buf, size))
3084 die("corrupt commit");
3085}
3086
3087static void check_tag(const void *buf, size_t size)
3088{
3089 struct tag t;
3090 memset(&t, 0, sizeof(t));
3091 if (parse_tag_buffer(&t, buf, size))
3092 die("corrupt tag");
3093}
3094
3095static int index_mem(unsigned char *sha1, void *buf, size_t size,
3096 enum object_type type,
3097 const char *path, unsigned flags)
3098{
3099 int ret, re_allocated = 0;
3100 int write_object = flags & HASH_WRITE_OBJECT;
3101
3102 if (!type)
3103 type = OBJ_BLOB;
3104
3105 /*
3106 * Convert blobs to git internal format
3107 */
3108 if ((type == OBJ_BLOB) && path) {
3109 struct strbuf nbuf = STRBUF_INIT;
3110 if (convert_to_git(path, buf, size, &nbuf,
3111 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
3112 buf = strbuf_detach(&nbuf, &size);
3113 re_allocated = 1;
3114 }
3115 }
3116 if (flags & HASH_FORMAT_CHECK) {
3117 if (type == OBJ_TREE)
3118 check_tree(buf, size);
3119 if (type == OBJ_COMMIT)
3120 check_commit(buf, size);
3121 if (type == OBJ_TAG)
3122 check_tag(buf, size);
3123 }
3124
3125 if (write_object)
3126 ret = write_sha1_file(buf, size, typename(type), sha1);
3127 else
3128 ret = hash_sha1_file(buf, size, typename(type), sha1);
3129 if (re_allocated)
3130 free(buf);
3131 return ret;
3132}
3133
3134static int index_stream_convert_blob(unsigned char *sha1, int fd,
3135 const char *path, unsigned flags)
3136{
3137 int ret;
3138 const int write_object = flags & HASH_WRITE_OBJECT;
3139 struct strbuf sbuf = STRBUF_INIT;
3140
3141 assert(path);
3142 assert(would_convert_to_git_filter_fd(path));
3143
3144 convert_to_git_filter_fd(path, fd, &sbuf,
3145 write_object ? safe_crlf : SAFE_CRLF_FALSE);
3146
3147 if (write_object)
3148 ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3149 sha1);
3150 else
3151 ret = hash_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),
3152 sha1);
3153 strbuf_release(&sbuf);
3154 return ret;
3155}
3156
3157static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3158 const char *path, unsigned flags)
3159{
3160 struct strbuf sbuf = STRBUF_INIT;
3161 int ret;
3162
3163 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3164 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3165 else
3166 ret = -1;
3167 strbuf_release(&sbuf);
3168 return ret;
3169}
3170
3171#define SMALL_FILE_SIZE (32*1024)
3172
3173static int index_core(unsigned char *sha1, int fd, size_t size,
3174 enum object_type type, const char *path,
3175 unsigned flags)
3176{
3177 int ret;
3178
3179 if (!size) {
3180 ret = index_mem(sha1, NULL, size, type, path, flags);
3181 } else if (size <= SMALL_FILE_SIZE) {
3182 char *buf = xmalloc(size);
3183 if (size == read_in_full(fd, buf, size))
3184 ret = index_mem(sha1, buf, size, type, path, flags);
3185 else
3186 ret = error("short read %s", strerror(errno));
3187 free(buf);
3188 } else {
3189 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3190 ret = index_mem(sha1, buf, size, type, path, flags);
3191 munmap(buf, size);
3192 }
3193 return ret;
3194}
3195
3196/*
3197 * This creates one packfile per large blob unless bulk-checkin
3198 * machinery is "plugged".
3199 *
3200 * This also bypasses the usual "convert-to-git" dance, and that is on
3201 * purpose. We could write a streaming version of the converting
3202 * functions and insert that before feeding the data to fast-import
3203 * (or equivalent in-core API described above). However, that is
3204 * somewhat complicated, as we do not know the size of the filter
3205 * result, which we need to know beforehand when writing a git object.
3206 * Since the primary motivation for trying to stream from the working
3207 * tree file and to avoid mmaping it in core is to deal with large
3208 * binary blobs, they generally do not want to get any conversion, and
3209 * callers should avoid this code path when filters are requested.
3210 */
3211static int index_stream(unsigned char *sha1, int fd, size_t size,
3212 enum object_type type, const char *path,
3213 unsigned flags)
3214{
3215 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3216}
3217
3218int index_fd(unsigned char *sha1, int fd, struct stat *st,
3219 enum object_type type, const char *path, unsigned flags)
3220{
3221 int ret;
3222
3223 /*
3224 * Call xsize_t() only when needed to avoid potentially unnecessary
3225 * die() for large files.
3226 */
3227 if (type == OBJ_BLOB && path && would_convert_to_git_filter_fd(path))
3228 ret = index_stream_convert_blob(sha1, fd, path, flags);
3229 else if (!S_ISREG(st->st_mode))
3230 ret = index_pipe(sha1, fd, type, path, flags);
3231 else if (st->st_size <= big_file_threshold || type != OBJ_BLOB ||
3232 (path && would_convert_to_git(path)))
3233 ret = index_core(sha1, fd, xsize_t(st->st_size), type, path,
3234 flags);
3235 else
3236 ret = index_stream(sha1, fd, xsize_t(st->st_size), type, path,
3237 flags);
3238 close(fd);
3239 return ret;
3240}
3241
3242int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3243{
3244 int fd;
3245 struct strbuf sb = STRBUF_INIT;
3246
3247 switch (st->st_mode & S_IFMT) {
3248 case S_IFREG:
3249 fd = open(path, O_RDONLY);
3250 if (fd < 0)
3251 return error("open(\"%s\"): %s", path,
3252 strerror(errno));
3253 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3254 return error("%s: failed to insert into database",
3255 path);
3256 break;
3257 case S_IFLNK:
3258 if (strbuf_readlink(&sb, path, st->st_size)) {
3259 char *errstr = strerror(errno);
3260 return error("readlink(\"%s\"): %s", path,
3261 errstr);
3262 }
3263 if (!(flags & HASH_WRITE_OBJECT))
3264 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3265 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3266 return error("%s: failed to insert into database",
3267 path);
3268 strbuf_release(&sb);
3269 break;
3270 case S_IFDIR:
3271 return resolve_gitlink_ref(path, "HEAD", sha1);
3272 default:
3273 return error("%s: unsupported file type", path);
3274 }
3275 return 0;
3276}
3277
3278int read_pack_header(int fd, struct pack_header *header)
3279{
3280 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3281 /* "eof before pack header was fully read" */
3282 return PH_ERROR_EOF;
3283
3284 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3285 /* "protocol error (pack signature mismatch detected)" */
3286 return PH_ERROR_PACK_SIGNATURE;
3287 if (!pack_version_ok(header->hdr_version))
3288 /* "protocol error (pack version unsupported)" */
3289 return PH_ERROR_PROTOCOL;
3290 return 0;
3291}
3292
3293void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3294{
3295 enum object_type type = sha1_object_info(sha1, NULL);
3296 if (type < 0)
3297 die("%s is not a valid object", sha1_to_hex(sha1));
3298 if (type != expect)
3299 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3300 typename(expect));
3301}
3302
3303static int for_each_file_in_obj_subdir(int subdir_nr,
3304 struct strbuf *path,
3305 each_loose_object_fn obj_cb,
3306 each_loose_cruft_fn cruft_cb,
3307 each_loose_subdir_fn subdir_cb,
3308 void *data)
3309{
3310 size_t baselen = path->len;
3311 DIR *dir = opendir(path->buf);
3312 struct dirent *de;
3313 int r = 0;
3314
3315 if (!dir) {
3316 if (errno == ENOENT)
3317 return 0;
3318 return error("unable to open %s: %s", path->buf, strerror(errno));
3319 }
3320
3321 while ((de = readdir(dir))) {
3322 if (is_dot_or_dotdot(de->d_name))
3323 continue;
3324
3325 strbuf_setlen(path, baselen);
3326 strbuf_addf(path, "/%s", de->d_name);
3327
3328 if (strlen(de->d_name) == 38) {
3329 char hex[41];
3330 unsigned char sha1[20];
3331
3332 snprintf(hex, sizeof(hex), "%02x%s",
3333 subdir_nr, de->d_name);
3334 if (!get_sha1_hex(hex, sha1)) {
3335 if (obj_cb) {
3336 r = obj_cb(sha1, path->buf, data);
3337 if (r)
3338 break;
3339 }
3340 continue;
3341 }
3342 }
3343
3344 if (cruft_cb) {
3345 r = cruft_cb(de->d_name, path->buf, data);
3346 if (r)
3347 break;
3348 }
3349 }
3350 strbuf_setlen(path, baselen);
3351
3352 if (!r && subdir_cb)
3353 r = subdir_cb(subdir_nr, path->buf, data);
3354
3355 closedir(dir);
3356 return r;
3357}
3358
3359int for_each_loose_file_in_objdir(const char *path,
3360 each_loose_object_fn obj_cb,
3361 each_loose_cruft_fn cruft_cb,
3362 each_loose_subdir_fn subdir_cb,
3363 void *data)
3364{
3365 struct strbuf buf = STRBUF_INIT;
3366 size_t baselen;
3367 int r = 0;
3368 int i;
3369
3370 strbuf_addstr(&buf, path);
3371 strbuf_addch(&buf, '/');
3372 baselen = buf.len;
3373
3374 for (i = 0; i < 256; i++) {
3375 strbuf_addf(&buf, "%02x", i);
3376 r = for_each_file_in_obj_subdir(i, &buf, obj_cb, cruft_cb,
3377 subdir_cb, data);
3378 strbuf_setlen(&buf, baselen);
3379 if (r)
3380 break;
3381 }
3382
3383 strbuf_release(&buf);
3384 return r;
3385}
3386
3387struct loose_alt_odb_data {
3388 each_loose_object_fn *cb;
3389 void *data;
3390};
3391
3392static int loose_from_alt_odb(struct alternate_object_database *alt,
3393 void *vdata)
3394{
3395 struct loose_alt_odb_data *data = vdata;
3396 return for_each_loose_file_in_objdir(alt->base,
3397 data->cb, NULL, NULL,
3398 data->data);
3399}
3400
3401int for_each_loose_object(each_loose_object_fn cb, void *data)
3402{
3403 struct loose_alt_odb_data alt;
3404 int r;
3405
3406 r = for_each_loose_file_in_objdir(get_object_directory(),
3407 cb, NULL, NULL, data);
3408 if (r)
3409 return r;
3410
3411 alt.cb = cb;
3412 alt.data = data;
3413 return foreach_alt_odb(loose_from_alt_odb, &alt);
3414}
3415
3416static int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
3417{
3418 uint32_t i;
3419 int r = 0;
3420
3421 for (i = 0; i < p->num_objects; i++) {
3422 const unsigned char *sha1 = nth_packed_object_sha1(p, i);
3423
3424 if (!sha1)
3425 return error("unable to get sha1 of object %u in %s",
3426 i, p->pack_name);
3427
3428 r = cb(sha1, p, i, data);
3429 if (r)
3430 break;
3431 }
3432 return r;
3433}
3434
3435int for_each_packed_object(each_packed_object_fn cb, void *data)
3436{
3437 struct packed_git *p;
3438 int r = 0;
3439
3440 prepare_packed_git();
3441 for (p = packed_git; p; p = p->next) {
3442 r = for_each_object_in_pack(p, cb, data);
3443 if (r)
3444 break;
3445 }
3446 return r;
3447}