t8001/t8002: blame: add tests of -L line numbers less than 1
[git.git] / sha1_file.c
blob8e27db1bd2b49f28b235fcd7e18a0dda43a1f045
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
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 "delta.h"
12 #include "pack.h"
13 #include "blob.h"
14 #include "commit.h"
15 #include "run-command.h"
16 #include "tag.h"
17 #include "tree.h"
18 #include "tree-walk.h"
19 #include "refs.h"
20 #include "pack-revindex.h"
21 #include "sha1-lookup.h"
22 #include "bulk-checkin.h"
23 #include "streaming.h"
24 #include "dir.h"
26 #ifndef O_NOATIME
27 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
28 #define O_NOATIME 01000000
29 #else
30 #define O_NOATIME 0
31 #endif
32 #endif
34 #define SZ_FMT PRIuMAX
35 static inline uintmax_t sz_fmt(size_t s) { return s; }
37 const unsigned char null_sha1[20];
39 static const char *no_log_pack_access = "no_log_pack_access";
40 static const char *log_pack_access;
43 * This is meant to hold a *small* number of objects that you would
44 * want read_sha1_file() to be able to return, but yet you do not want
45 * to write them into the object store (e.g. a browse-only
46 * application).
48 static struct cached_object {
49 unsigned char sha1[20];
50 enum object_type type;
51 void *buf;
52 unsigned long size;
53 } *cached_objects;
54 static int cached_object_nr, cached_object_alloc;
56 static struct cached_object empty_tree = {
57 EMPTY_TREE_SHA1_BIN_LITERAL,
58 OBJ_TREE,
59 "",
63 static struct packed_git *last_found_pack;
65 static struct cached_object *find_cached_object(const unsigned char *sha1)
67 int i;
68 struct cached_object *co = cached_objects;
70 for (i = 0; i < cached_object_nr; i++, co++) {
71 if (!hashcmp(co->sha1, sha1))
72 return co;
74 if (!hashcmp(sha1, empty_tree.sha1))
75 return &empty_tree;
76 return NULL;
79 int mkdir_in_gitdir(const char *path)
81 if (mkdir(path, 0777)) {
82 int saved_errno = errno;
83 struct stat st;
84 struct strbuf sb = STRBUF_INIT;
86 if (errno != EEXIST)
87 return -1;
89 * Are we looking at a path in a symlinked worktree
90 * whose original repository does not yet have it?
91 * e.g. .git/rr-cache pointing at its original
92 * repository in which the user hasn't performed any
93 * conflict resolution yet?
95 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
96 strbuf_readlink(&sb, path, st.st_size) ||
97 !is_absolute_path(sb.buf) ||
98 mkdir(sb.buf, 0777)) {
99 strbuf_release(&sb);
100 errno = saved_errno;
101 return -1;
103 strbuf_release(&sb);
105 return adjust_shared_perm(path);
108 int safe_create_leading_directories(char *path)
110 char *pos = path + offset_1st_component(path);
111 struct stat st;
113 while (pos) {
114 pos = strchr(pos, '/');
115 if (!pos)
116 break;
117 while (*++pos == '/')
119 if (!*pos)
120 break;
121 *--pos = '\0';
122 if (!stat(path, &st)) {
123 /* path exists */
124 if (!S_ISDIR(st.st_mode)) {
125 *pos = '/';
126 return -3;
129 else if (mkdir(path, 0777)) {
130 if (errno == EEXIST &&
131 !stat(path, &st) && S_ISDIR(st.st_mode)) {
132 ; /* somebody created it since we checked */
133 } else {
134 *pos = '/';
135 return -1;
138 else if (adjust_shared_perm(path)) {
139 *pos = '/';
140 return -2;
142 *pos++ = '/';
144 return 0;
147 int safe_create_leading_directories_const(const char *path)
149 /* path points to cache entries, so xstrdup before messing with it */
150 char *buf = xstrdup(path);
151 int result = safe_create_leading_directories(buf);
152 free(buf);
153 return result;
156 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
158 int i;
159 for (i = 0; i < 20; i++) {
160 static char hex[] = "0123456789abcdef";
161 unsigned int val = sha1[i];
162 char *pos = pathbuf + i*2 + (i > 0);
163 *pos++ = hex[val >> 4];
164 *pos = hex[val & 0xf];
169 * NOTE! This returns a statically allocated buffer, so you have to be
170 * careful about using it. Do an "xstrdup()" if you need to save the
171 * filename.
173 * Also note that this returns the location for creating. Reading
174 * SHA1 file can happen from any alternate directory listed in the
175 * DB_ENVIRONMENT environment variable if it is not found in
176 * the primary object database.
178 char *sha1_file_name(const unsigned char *sha1)
180 static char buf[PATH_MAX];
181 const char *objdir;
182 int len;
184 objdir = get_object_directory();
185 len = strlen(objdir);
187 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
188 if (len + 43 > PATH_MAX)
189 die("insanely long object directory %s", objdir);
190 memcpy(buf, objdir, len);
191 buf[len] = '/';
192 buf[len+3] = '/';
193 buf[len+42] = '\0';
194 fill_sha1_path(buf + len + 1, sha1);
195 return buf;
198 static char *sha1_get_pack_name(const unsigned char *sha1,
199 char **name, char **base, const char *which)
201 static const char hex[] = "0123456789abcdef";
202 char *buf;
203 int i;
205 if (!*base) {
206 const char *sha1_file_directory = get_object_directory();
207 int len = strlen(sha1_file_directory);
208 *base = xmalloc(len + 60);
209 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
210 sha1_file_directory, which);
211 *name = *base + len + 11;
214 buf = *name;
216 for (i = 0; i < 20; i++) {
217 unsigned int val = *sha1++;
218 *buf++ = hex[val >> 4];
219 *buf++ = hex[val & 0xf];
222 return *base;
225 char *sha1_pack_name(const unsigned char *sha1)
227 static char *name, *base;
229 return sha1_get_pack_name(sha1, &name, &base, "pack");
232 char *sha1_pack_index_name(const unsigned char *sha1)
234 static char *name, *base;
236 return sha1_get_pack_name(sha1, &name, &base, "idx");
239 struct alternate_object_database *alt_odb_list;
240 static struct alternate_object_database **alt_odb_tail;
242 static int git_open_noatime(const char *name);
245 * Prepare alternate object database registry.
247 * The variable alt_odb_list points at the list of struct
248 * alternate_object_database. The elements on this list come from
249 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
250 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
251 * whose contents is similar to that environment variable but can be
252 * LF separated. Its base points at a statically allocated buffer that
253 * contains "/the/directory/corresponding/to/.git/objects/...", while
254 * its name points just after the slash at the end of ".git/objects/"
255 * in the example above, and has enough space to hold 40-byte hex
256 * SHA1, an extra slash for the first level indirection, and the
257 * terminating NUL.
259 static int link_alt_odb_entry(const char *entry, const char *relative_base, int depth)
261 const char *objdir = get_object_directory();
262 struct alternate_object_database *ent;
263 struct alternate_object_database *alt;
264 int pfxlen, entlen;
265 struct strbuf pathbuf = STRBUF_INIT;
267 if (!is_absolute_path(entry) && relative_base) {
268 strbuf_addstr(&pathbuf, real_path(relative_base));
269 strbuf_addch(&pathbuf, '/');
271 strbuf_addstr(&pathbuf, entry);
273 normalize_path_copy(pathbuf.buf, pathbuf.buf);
275 pfxlen = strlen(pathbuf.buf);
278 * The trailing slash after the directory name is given by
279 * this function at the end. Remove duplicates.
281 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
282 pfxlen -= 1;
284 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
285 ent = xmalloc(sizeof(*ent) + entlen);
286 memcpy(ent->base, pathbuf.buf, pfxlen);
287 strbuf_release(&pathbuf);
289 ent->name = ent->base + pfxlen + 1;
290 ent->base[pfxlen + 3] = '/';
291 ent->base[pfxlen] = ent->base[entlen-1] = 0;
293 /* Detect cases where alternate disappeared */
294 if (!is_directory(ent->base)) {
295 error("object directory %s does not exist; "
296 "check .git/objects/info/alternates.",
297 ent->base);
298 free(ent);
299 return -1;
302 /* Prevent the common mistake of listing the same
303 * thing twice, or object directory itself.
305 for (alt = alt_odb_list; alt; alt = alt->next) {
306 if (!memcmp(ent->base, alt->base, pfxlen)) {
307 free(ent);
308 return -1;
311 if (!strcmp(ent->base, objdir)) {
312 free(ent);
313 return -1;
316 /* add the alternate entry */
317 *alt_odb_tail = ent;
318 alt_odb_tail = &(ent->next);
319 ent->next = NULL;
321 /* recursively add alternates */
322 read_info_alternates(ent->base, depth + 1);
324 ent->base[pfxlen] = '/';
326 return 0;
329 static void link_alt_odb_entries(const char *alt, int len, int sep,
330 const char *relative_base, int depth)
332 struct string_list entries = STRING_LIST_INIT_NODUP;
333 char *alt_copy;
334 int i;
336 if (depth > 5) {
337 error("%s: ignoring alternate object stores, nesting too deep.",
338 relative_base);
339 return;
342 alt_copy = xmemdupz(alt, len);
343 string_list_split_in_place(&entries, alt_copy, sep, -1);
344 for (i = 0; i < entries.nr; i++) {
345 const char *entry = entries.items[i].string;
346 if (entry[0] == '\0' || entry[0] == '#')
347 continue;
348 if (!is_absolute_path(entry) && depth) {
349 error("%s: ignoring relative alternate object store %s",
350 relative_base, entry);
351 } else {
352 link_alt_odb_entry(entry, relative_base, depth);
355 string_list_clear(&entries, 0);
356 free(alt_copy);
359 void read_info_alternates(const char * relative_base, int depth)
361 char *map;
362 size_t mapsz;
363 struct stat st;
364 const char alt_file_name[] = "info/alternates";
365 /* Given that relative_base is no longer than PATH_MAX,
366 ensure that "path" has enough space to append "/", the
367 file name, "info/alternates", and a trailing NUL. */
368 char path[PATH_MAX + 1 + sizeof alt_file_name];
369 int fd;
371 sprintf(path, "%s/%s", relative_base, alt_file_name);
372 fd = git_open_noatime(path);
373 if (fd < 0)
374 return;
375 if (fstat(fd, &st) || (st.st_size == 0)) {
376 close(fd);
377 return;
379 mapsz = xsize_t(st.st_size);
380 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
381 close(fd);
383 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
385 munmap(map, mapsz);
388 void add_to_alternates_file(const char *reference)
390 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
391 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
392 char *alt = mkpath("%s\n", reference);
393 write_or_die(fd, alt, strlen(alt));
394 if (commit_lock_file(lock))
395 die("could not close alternates file");
396 if (alt_odb_tail)
397 link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
400 void foreach_alt_odb(alt_odb_fn fn, void *cb)
402 struct alternate_object_database *ent;
404 prepare_alt_odb();
405 for (ent = alt_odb_list; ent; ent = ent->next)
406 if (fn(ent, cb))
407 return;
410 void prepare_alt_odb(void)
412 const char *alt;
414 if (alt_odb_tail)
415 return;
417 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
418 if (!alt) alt = "";
420 alt_odb_tail = &alt_odb_list;
421 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
423 read_info_alternates(get_object_directory(), 0);
426 static int has_loose_object_local(const unsigned char *sha1)
428 char *name = sha1_file_name(sha1);
429 return !access(name, F_OK);
432 int has_loose_object_nonlocal(const unsigned char *sha1)
434 struct alternate_object_database *alt;
435 prepare_alt_odb();
436 for (alt = alt_odb_list; alt; alt = alt->next) {
437 fill_sha1_path(alt->name, sha1);
438 if (!access(alt->base, F_OK))
439 return 1;
441 return 0;
444 static int has_loose_object(const unsigned char *sha1)
446 return has_loose_object_local(sha1) ||
447 has_loose_object_nonlocal(sha1);
450 static unsigned int pack_used_ctr;
451 static unsigned int pack_mmap_calls;
452 static unsigned int peak_pack_open_windows;
453 static unsigned int pack_open_windows;
454 static unsigned int pack_open_fds;
455 static unsigned int pack_max_fds;
456 static size_t peak_pack_mapped;
457 static size_t pack_mapped;
458 struct packed_git *packed_git;
460 void pack_report(void)
462 fprintf(stderr,
463 "pack_report: getpagesize() = %10" SZ_FMT "\n"
464 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
465 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
466 sz_fmt(getpagesize()),
467 sz_fmt(packed_git_window_size),
468 sz_fmt(packed_git_limit));
469 fprintf(stderr,
470 "pack_report: pack_used_ctr = %10u\n"
471 "pack_report: pack_mmap_calls = %10u\n"
472 "pack_report: pack_open_windows = %10u / %10u\n"
473 "pack_report: pack_mapped = "
474 "%10" SZ_FMT " / %10" SZ_FMT "\n",
475 pack_used_ctr,
476 pack_mmap_calls,
477 pack_open_windows, peak_pack_open_windows,
478 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
481 static int check_packed_git_idx(const char *path, struct packed_git *p)
483 void *idx_map;
484 struct pack_idx_header *hdr;
485 size_t idx_size;
486 uint32_t version, nr, i, *index;
487 int fd = git_open_noatime(path);
488 struct stat st;
490 if (fd < 0)
491 return -1;
492 if (fstat(fd, &st)) {
493 close(fd);
494 return -1;
496 idx_size = xsize_t(st.st_size);
497 if (idx_size < 4 * 256 + 20 + 20) {
498 close(fd);
499 return error("index file %s is too small", path);
501 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
502 close(fd);
504 hdr = idx_map;
505 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
506 version = ntohl(hdr->idx_version);
507 if (version < 2 || version > 2) {
508 munmap(idx_map, idx_size);
509 return error("index file %s is version %"PRIu32
510 " and is not supported by this binary"
511 " (try upgrading GIT to a newer version)",
512 path, version);
514 } else
515 version = 1;
517 nr = 0;
518 index = idx_map;
519 if (version > 1)
520 index += 2; /* skip index header */
521 for (i = 0; i < 256; i++) {
522 uint32_t n = ntohl(index[i]);
523 if (n < nr) {
524 munmap(idx_map, idx_size);
525 return error("non-monotonic index %s", path);
527 nr = n;
530 if (version == 1) {
532 * Total size:
533 * - 256 index entries 4 bytes each
534 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
535 * - 20-byte SHA1 of the packfile
536 * - 20-byte SHA1 file checksum
538 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
539 munmap(idx_map, idx_size);
540 return error("wrong index v1 file size in %s", path);
542 } else if (version == 2) {
544 * Minimum size:
545 * - 8 bytes of header
546 * - 256 index entries 4 bytes each
547 * - 20-byte sha1 entry * nr
548 * - 4-byte crc entry * nr
549 * - 4-byte offset entry * nr
550 * - 20-byte SHA1 of the packfile
551 * - 20-byte SHA1 file checksum
552 * And after the 4-byte offset table might be a
553 * variable sized table containing 8-byte entries
554 * for offsets larger than 2^31.
556 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
557 unsigned long max_size = min_size;
558 if (nr)
559 max_size += (nr - 1)*8;
560 if (idx_size < min_size || idx_size > max_size) {
561 munmap(idx_map, idx_size);
562 return error("wrong index v2 file size in %s", path);
564 if (idx_size != min_size &&
566 * make sure we can deal with large pack offsets.
567 * 31-bit signed offset won't be enough, neither
568 * 32-bit unsigned one will be.
570 (sizeof(off_t) <= 4)) {
571 munmap(idx_map, idx_size);
572 return error("pack too large for current definition of off_t in %s", path);
576 p->index_version = version;
577 p->index_data = idx_map;
578 p->index_size = idx_size;
579 p->num_objects = nr;
580 return 0;
583 int open_pack_index(struct packed_git *p)
585 char *idx_name;
586 int ret;
588 if (p->index_data)
589 return 0;
591 idx_name = xstrdup(p->pack_name);
592 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
593 ret = check_packed_git_idx(idx_name, p);
594 free(idx_name);
595 return ret;
598 static void scan_windows(struct packed_git *p,
599 struct packed_git **lru_p,
600 struct pack_window **lru_w,
601 struct pack_window **lru_l)
603 struct pack_window *w, *w_l;
605 for (w_l = NULL, w = p->windows; w; w = w->next) {
606 if (!w->inuse_cnt) {
607 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
608 *lru_p = p;
609 *lru_w = w;
610 *lru_l = w_l;
613 w_l = w;
617 static int unuse_one_window(struct packed_git *current, int keep_fd)
619 struct packed_git *p, *lru_p = NULL;
620 struct pack_window *lru_w = NULL, *lru_l = NULL;
622 if (current)
623 scan_windows(current, &lru_p, &lru_w, &lru_l);
624 for (p = packed_git; p; p = p->next)
625 scan_windows(p, &lru_p, &lru_w, &lru_l);
626 if (lru_p) {
627 munmap(lru_w->base, lru_w->len);
628 pack_mapped -= lru_w->len;
629 if (lru_l)
630 lru_l->next = lru_w->next;
631 else {
632 lru_p->windows = lru_w->next;
633 if (!lru_p->windows && lru_p->pack_fd != -1
634 && lru_p->pack_fd != keep_fd) {
635 close(lru_p->pack_fd);
636 pack_open_fds--;
637 lru_p->pack_fd = -1;
640 free(lru_w);
641 pack_open_windows--;
642 return 1;
644 return 0;
647 void release_pack_memory(size_t need, int fd)
649 size_t cur = pack_mapped;
650 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
651 ; /* nothing */
654 void *xmmap(void *start, size_t length,
655 int prot, int flags, int fd, off_t offset)
657 void *ret = mmap(start, length, prot, flags, fd, offset);
658 if (ret == MAP_FAILED) {
659 if (!length)
660 return NULL;
661 release_pack_memory(length, fd);
662 ret = mmap(start, length, prot, flags, fd, offset);
663 if (ret == MAP_FAILED)
664 die_errno("Out of memory? mmap failed");
666 return ret;
669 void close_pack_windows(struct packed_git *p)
671 while (p->windows) {
672 struct pack_window *w = p->windows;
674 if (w->inuse_cnt)
675 die("pack '%s' still has open windows to it",
676 p->pack_name);
677 munmap(w->base, w->len);
678 pack_mapped -= w->len;
679 pack_open_windows--;
680 p->windows = w->next;
681 free(w);
685 void unuse_pack(struct pack_window **w_cursor)
687 struct pack_window *w = *w_cursor;
688 if (w) {
689 w->inuse_cnt--;
690 *w_cursor = NULL;
694 void close_pack_index(struct packed_git *p)
696 if (p->index_data) {
697 munmap((void *)p->index_data, p->index_size);
698 p->index_data = NULL;
703 * This is used by git-repack in case a newly created pack happens to
704 * contain the same set of objects as an existing one. In that case
705 * the resulting file might be different even if its name would be the
706 * same. It is best to close any reference to the old pack before it is
707 * replaced on disk. Of course no index pointers nor windows for given pack
708 * must subsist at this point. If ever objects from this pack are requested
709 * again, the new version of the pack will be reinitialized through
710 * reprepare_packed_git().
712 void free_pack_by_name(const char *pack_name)
714 struct packed_git *p, **pp = &packed_git;
716 while (*pp) {
717 p = *pp;
718 if (strcmp(pack_name, p->pack_name) == 0) {
719 clear_delta_base_cache();
720 close_pack_windows(p);
721 if (p->pack_fd != -1) {
722 close(p->pack_fd);
723 pack_open_fds--;
725 close_pack_index(p);
726 free(p->bad_object_sha1);
727 *pp = p->next;
728 if (last_found_pack == p)
729 last_found_pack = NULL;
730 free(p);
731 return;
733 pp = &p->next;
737 static unsigned int get_max_fd_limit(void)
739 #ifdef RLIMIT_NOFILE
740 struct rlimit lim;
742 if (getrlimit(RLIMIT_NOFILE, &lim))
743 die_errno("cannot get RLIMIT_NOFILE");
745 return lim.rlim_cur;
746 #elif defined(_SC_OPEN_MAX)
747 return sysconf(_SC_OPEN_MAX);
748 #elif defined(OPEN_MAX)
749 return OPEN_MAX;
750 #else
751 return 1; /* see the caller ;-) */
752 #endif
756 * Do not call this directly as this leaks p->pack_fd on error return;
757 * call open_packed_git() instead.
759 static int open_packed_git_1(struct packed_git *p)
761 struct stat st;
762 struct pack_header hdr;
763 unsigned char sha1[20];
764 unsigned char *idx_sha1;
765 long fd_flag;
767 if (!p->index_data && open_pack_index(p))
768 return error("packfile %s index unavailable", p->pack_name);
770 if (!pack_max_fds) {
771 unsigned int max_fds = get_max_fd_limit();
773 /* Save 3 for stdin/stdout/stderr, 22 for work */
774 if (25 < max_fds)
775 pack_max_fds = max_fds - 25;
776 else
777 pack_max_fds = 1;
780 while (pack_max_fds <= pack_open_fds && unuse_one_window(NULL, -1))
781 ; /* nothing */
783 p->pack_fd = git_open_noatime(p->pack_name);
784 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
785 return -1;
786 pack_open_fds++;
788 /* If we created the struct before we had the pack we lack size. */
789 if (!p->pack_size) {
790 if (!S_ISREG(st.st_mode))
791 return error("packfile %s not a regular file", p->pack_name);
792 p->pack_size = st.st_size;
793 } else if (p->pack_size != st.st_size)
794 return error("packfile %s size changed", p->pack_name);
796 /* We leave these file descriptors open with sliding mmap;
797 * there is no point keeping them open across exec(), though.
799 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
800 if (fd_flag < 0)
801 return error("cannot determine file descriptor flags");
802 fd_flag |= FD_CLOEXEC;
803 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
804 return error("cannot set FD_CLOEXEC");
806 /* Verify we recognize this pack file format. */
807 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
808 return error("file %s is far too short to be a packfile", p->pack_name);
809 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
810 return error("file %s is not a GIT packfile", p->pack_name);
811 if (!pack_version_ok(hdr.hdr_version))
812 return error("packfile %s is version %"PRIu32" and not"
813 " supported (try upgrading GIT to a newer version)",
814 p->pack_name, ntohl(hdr.hdr_version));
816 /* Verify the pack matches its index. */
817 if (p->num_objects != ntohl(hdr.hdr_entries))
818 return error("packfile %s claims to have %"PRIu32" objects"
819 " while index indicates %"PRIu32" objects",
820 p->pack_name, ntohl(hdr.hdr_entries),
821 p->num_objects);
822 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
823 return error("end of packfile %s is unavailable", p->pack_name);
824 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
825 return error("packfile %s signature is unavailable", p->pack_name);
826 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
827 if (hashcmp(sha1, idx_sha1))
828 return error("packfile %s does not match index", p->pack_name);
829 return 0;
832 static int open_packed_git(struct packed_git *p)
834 if (!open_packed_git_1(p))
835 return 0;
836 if (p->pack_fd != -1) {
837 close(p->pack_fd);
838 pack_open_fds--;
839 p->pack_fd = -1;
841 return -1;
844 static int in_window(struct pack_window *win, off_t offset)
846 /* We must promise at least 20 bytes (one hash) after the
847 * offset is available from this window, otherwise the offset
848 * is not actually in this window and a different window (which
849 * has that one hash excess) must be used. This is to support
850 * the object header and delta base parsing routines below.
852 off_t win_off = win->offset;
853 return win_off <= offset
854 && (offset + 20) <= (win_off + win->len);
857 unsigned char *use_pack(struct packed_git *p,
858 struct pack_window **w_cursor,
859 off_t offset,
860 unsigned long *left)
862 struct pack_window *win = *w_cursor;
864 /* Since packfiles end in a hash of their content and it's
865 * pointless to ask for an offset into the middle of that
866 * hash, and the in_window function above wouldn't match
867 * don't allow an offset too close to the end of the file.
869 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
870 die("packfile %s cannot be accessed", p->pack_name);
871 if (offset > (p->pack_size - 20))
872 die("offset beyond end of packfile (truncated pack?)");
874 if (!win || !in_window(win, offset)) {
875 if (win)
876 win->inuse_cnt--;
877 for (win = p->windows; win; win = win->next) {
878 if (in_window(win, offset))
879 break;
881 if (!win) {
882 size_t window_align = packed_git_window_size / 2;
883 off_t len;
885 if (p->pack_fd == -1 && open_packed_git(p))
886 die("packfile %s cannot be accessed", p->pack_name);
888 win = xcalloc(1, sizeof(*win));
889 win->offset = (offset / window_align) * window_align;
890 len = p->pack_size - win->offset;
891 if (len > packed_git_window_size)
892 len = packed_git_window_size;
893 win->len = (size_t)len;
894 pack_mapped += win->len;
895 while (packed_git_limit < pack_mapped
896 && unuse_one_window(p, p->pack_fd))
897 ; /* nothing */
898 win->base = xmmap(NULL, win->len,
899 PROT_READ, MAP_PRIVATE,
900 p->pack_fd, win->offset);
901 if (win->base == MAP_FAILED)
902 die("packfile %s cannot be mapped: %s",
903 p->pack_name,
904 strerror(errno));
905 if (!win->offset && win->len == p->pack_size
906 && !p->do_not_close) {
907 close(p->pack_fd);
908 pack_open_fds--;
909 p->pack_fd = -1;
911 pack_mmap_calls++;
912 pack_open_windows++;
913 if (pack_mapped > peak_pack_mapped)
914 peak_pack_mapped = pack_mapped;
915 if (pack_open_windows > peak_pack_open_windows)
916 peak_pack_open_windows = pack_open_windows;
917 win->next = p->windows;
918 p->windows = win;
921 if (win != *w_cursor) {
922 win->last_used = pack_used_ctr++;
923 win->inuse_cnt++;
924 *w_cursor = win;
926 offset -= win->offset;
927 if (left)
928 *left = win->len - xsize_t(offset);
929 return win->base + offset;
932 static struct packed_git *alloc_packed_git(int extra)
934 struct packed_git *p = xmalloc(sizeof(*p) + extra);
935 memset(p, 0, sizeof(*p));
936 p->pack_fd = -1;
937 return p;
940 static void try_to_free_pack_memory(size_t size)
942 release_pack_memory(size, -1);
945 struct packed_git *add_packed_git(const char *path, int path_len, int local)
947 static int have_set_try_to_free_routine;
948 struct stat st;
949 struct packed_git *p = alloc_packed_git(path_len + 2);
951 if (!have_set_try_to_free_routine) {
952 have_set_try_to_free_routine = 1;
953 set_try_to_free_routine(try_to_free_pack_memory);
957 * Make sure a corresponding .pack file exists and that
958 * the index looks sane.
960 path_len -= strlen(".idx");
961 if (path_len < 1) {
962 free(p);
963 return NULL;
965 memcpy(p->pack_name, path, path_len);
967 strcpy(p->pack_name + path_len, ".keep");
968 if (!access(p->pack_name, F_OK))
969 p->pack_keep = 1;
971 strcpy(p->pack_name + path_len, ".pack");
972 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
973 free(p);
974 return NULL;
977 /* ok, it looks sane as far as we can check without
978 * actually mapping the pack file.
980 p->pack_size = st.st_size;
981 p->pack_local = local;
982 p->mtime = st.st_mtime;
983 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
984 hashclr(p->sha1);
985 return p;
988 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
990 const char *path = sha1_pack_name(sha1);
991 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
993 strcpy(p->pack_name, path);
994 hashcpy(p->sha1, sha1);
995 if (check_packed_git_idx(idx_path, p)) {
996 free(p);
997 return NULL;
1000 return p;
1003 void install_packed_git(struct packed_git *pack)
1005 if (pack->pack_fd != -1)
1006 pack_open_fds++;
1008 pack->next = packed_git;
1009 packed_git = pack;
1012 void (*report_garbage)(const char *desc, const char *path);
1014 static void report_helper(const struct string_list *list,
1015 int seen_bits, int first, int last)
1017 const char *msg;
1018 switch (seen_bits) {
1019 case 0:
1020 msg = "no corresponding .idx nor .pack";
1021 break;
1022 case 1:
1023 msg = "no corresponding .idx";
1024 break;
1025 case 2:
1026 msg = "no corresponding .pack";
1027 break;
1028 default:
1029 return;
1031 for (; first < last; first++)
1032 report_garbage(msg, list->items[first].string);
1035 static void report_pack_garbage(struct string_list *list)
1037 int i, baselen = -1, first = 0, seen_bits = 0;
1039 if (!report_garbage)
1040 return;
1042 sort_string_list(list);
1044 for (i = 0; i < list->nr; i++) {
1045 const char *path = list->items[i].string;
1046 if (baselen != -1 &&
1047 strncmp(path, list->items[first].string, baselen)) {
1048 report_helper(list, seen_bits, first, i);
1049 baselen = -1;
1050 seen_bits = 0;
1052 if (baselen == -1) {
1053 const char *dot = strrchr(path, '.');
1054 if (!dot) {
1055 report_garbage("garbage found", path);
1056 continue;
1058 baselen = dot - path + 1;
1059 first = i;
1061 if (!strcmp(path + baselen, "pack"))
1062 seen_bits |= 1;
1063 else if (!strcmp(path + baselen, "idx"))
1064 seen_bits |= 2;
1066 report_helper(list, seen_bits, first, list->nr);
1069 static void prepare_packed_git_one(char *objdir, int local)
1071 /* Ensure that this buffer is large enough so that we can
1072 append "/pack/" without clobbering the stack even if
1073 strlen(objdir) were PATH_MAX. */
1074 char path[PATH_MAX + 1 + 4 + 1 + 1];
1075 int len;
1076 DIR *dir;
1077 struct dirent *de;
1078 struct string_list garbage = STRING_LIST_INIT_DUP;
1080 sprintf(path, "%s/pack", objdir);
1081 len = strlen(path);
1082 dir = opendir(path);
1083 if (!dir) {
1084 if (errno != ENOENT)
1085 error("unable to open object pack directory: %s: %s",
1086 path, strerror(errno));
1087 return;
1089 path[len++] = '/';
1090 while ((de = readdir(dir)) != NULL) {
1091 int namelen = strlen(de->d_name);
1092 struct packed_git *p;
1094 if (len + namelen + 1 > sizeof(path)) {
1095 if (report_garbage) {
1096 struct strbuf sb = STRBUF_INIT;
1097 strbuf_addf(&sb, "%.*s/%s", len - 1, path, de->d_name);
1098 report_garbage("path too long", sb.buf);
1099 strbuf_release(&sb);
1101 continue;
1104 if (is_dot_or_dotdot(de->d_name))
1105 continue;
1107 strcpy(path + len, de->d_name);
1109 if (has_extension(de->d_name, ".idx")) {
1110 /* Don't reopen a pack we already have. */
1111 for (p = packed_git; p; p = p->next) {
1112 if (!memcmp(path, p->pack_name, len + namelen - 4))
1113 break;
1115 if (p == NULL &&
1117 * See if it really is a valid .idx file with
1118 * corresponding .pack file that we can map.
1120 (p = add_packed_git(path, len + namelen, local)) != NULL)
1121 install_packed_git(p);
1124 if (!report_garbage)
1125 continue;
1127 if (has_extension(de->d_name, ".idx") ||
1128 has_extension(de->d_name, ".pack") ||
1129 has_extension(de->d_name, ".keep"))
1130 string_list_append(&garbage, path);
1131 else
1132 report_garbage("garbage found", path);
1134 closedir(dir);
1135 report_pack_garbage(&garbage);
1136 string_list_clear(&garbage, 0);
1139 static int sort_pack(const void *a_, const void *b_)
1141 struct packed_git *a = *((struct packed_git **)a_);
1142 struct packed_git *b = *((struct packed_git **)b_);
1143 int st;
1146 * Local packs tend to contain objects specific to our
1147 * variant of the project than remote ones. In addition,
1148 * remote ones could be on a network mounted filesystem.
1149 * Favor local ones for these reasons.
1151 st = a->pack_local - b->pack_local;
1152 if (st)
1153 return -st;
1156 * Younger packs tend to contain more recent objects,
1157 * and more recent objects tend to get accessed more
1158 * often.
1160 if (a->mtime < b->mtime)
1161 return 1;
1162 else if (a->mtime == b->mtime)
1163 return 0;
1164 return -1;
1167 static void rearrange_packed_git(void)
1169 struct packed_git **ary, *p;
1170 int i, n;
1172 for (n = 0, p = packed_git; p; p = p->next)
1173 n++;
1174 if (n < 2)
1175 return;
1177 /* prepare an array of packed_git for easier sorting */
1178 ary = xcalloc(n, sizeof(struct packed_git *));
1179 for (n = 0, p = packed_git; p; p = p->next)
1180 ary[n++] = p;
1182 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1184 /* link them back again */
1185 for (i = 0; i < n - 1; i++)
1186 ary[i]->next = ary[i + 1];
1187 ary[n - 1]->next = NULL;
1188 packed_git = ary[0];
1190 free(ary);
1193 static int prepare_packed_git_run_once = 0;
1194 void prepare_packed_git(void)
1196 struct alternate_object_database *alt;
1198 if (prepare_packed_git_run_once)
1199 return;
1200 prepare_packed_git_one(get_object_directory(), 1);
1201 prepare_alt_odb();
1202 for (alt = alt_odb_list; alt; alt = alt->next) {
1203 alt->name[-1] = 0;
1204 prepare_packed_git_one(alt->base, 0);
1205 alt->name[-1] = '/';
1207 rearrange_packed_git();
1208 prepare_packed_git_run_once = 1;
1211 void reprepare_packed_git(void)
1213 discard_revindex();
1214 prepare_packed_git_run_once = 0;
1215 prepare_packed_git();
1218 static void mark_bad_packed_object(struct packed_git *p,
1219 const unsigned char *sha1)
1221 unsigned i;
1222 for (i = 0; i < p->num_bad_objects; i++)
1223 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1224 return;
1225 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1226 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1227 p->num_bad_objects++;
1230 static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1232 struct packed_git *p;
1233 unsigned i;
1235 for (p = packed_git; p; p = p->next)
1236 for (i = 0; i < p->num_bad_objects; i++)
1237 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1238 return p;
1239 return NULL;
1243 * With an in-core object data in "map", rehash it to make sure the
1244 * object name actually matches "sha1" to detect object corruption.
1245 * With "map" == NULL, try reading the object named with "sha1" using
1246 * the streaming interface and rehash it to do the same.
1248 int check_sha1_signature(const unsigned char *sha1, void *map,
1249 unsigned long size, const char *type)
1251 unsigned char real_sha1[20];
1252 enum object_type obj_type;
1253 struct git_istream *st;
1254 git_SHA_CTX c;
1255 char hdr[32];
1256 int hdrlen;
1258 if (map) {
1259 hash_sha1_file(map, size, type, real_sha1);
1260 return hashcmp(sha1, real_sha1) ? -1 : 0;
1263 st = open_istream(sha1, &obj_type, &size, NULL);
1264 if (!st)
1265 return -1;
1267 /* Generate the header */
1268 hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
1270 /* Sha1.. */
1271 git_SHA1_Init(&c);
1272 git_SHA1_Update(&c, hdr, hdrlen);
1273 for (;;) {
1274 char buf[1024 * 16];
1275 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1277 if (readlen < 0) {
1278 close_istream(st);
1279 return -1;
1281 if (!readlen)
1282 break;
1283 git_SHA1_Update(&c, buf, readlen);
1285 git_SHA1_Final(real_sha1, &c);
1286 close_istream(st);
1287 return hashcmp(sha1, real_sha1) ? -1 : 0;
1290 static int git_open_noatime(const char *name)
1292 static int sha1_file_open_flag = O_NOATIME;
1294 for (;;) {
1295 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1296 if (fd >= 0)
1297 return fd;
1299 /* Might the failure be due to O_NOATIME? */
1300 if (errno != ENOENT && sha1_file_open_flag) {
1301 sha1_file_open_flag = 0;
1302 continue;
1305 return -1;
1309 static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1311 char *name = sha1_file_name(sha1);
1312 struct alternate_object_database *alt;
1314 if (!lstat(name, st))
1315 return 0;
1317 prepare_alt_odb();
1318 errno = ENOENT;
1319 for (alt = alt_odb_list; alt; alt = alt->next) {
1320 name = alt->name;
1321 fill_sha1_path(name, sha1);
1322 if (!lstat(alt->base, st))
1323 return 0;
1326 return -1;
1329 static int open_sha1_file(const unsigned char *sha1)
1331 int fd;
1332 char *name = sha1_file_name(sha1);
1333 struct alternate_object_database *alt;
1335 fd = git_open_noatime(name);
1336 if (fd >= 0)
1337 return fd;
1339 prepare_alt_odb();
1340 errno = ENOENT;
1341 for (alt = alt_odb_list; alt; alt = alt->next) {
1342 name = alt->name;
1343 fill_sha1_path(name, sha1);
1344 fd = git_open_noatime(alt->base);
1345 if (fd >= 0)
1346 return fd;
1348 return -1;
1351 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1353 void *map;
1354 int fd;
1356 fd = open_sha1_file(sha1);
1357 map = NULL;
1358 if (fd >= 0) {
1359 struct stat st;
1361 if (!fstat(fd, &st)) {
1362 *size = xsize_t(st.st_size);
1363 if (!*size) {
1364 /* mmap() is forbidden on empty files */
1365 error("object file %s is empty", sha1_file_name(sha1));
1366 return NULL;
1368 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1370 close(fd);
1372 return map;
1376 * There used to be a second loose object header format which
1377 * was meant to mimic the in-pack format, allowing for direct
1378 * copy of the object data. This format turned up not to be
1379 * really worth it and we no longer write loose objects in that
1380 * format.
1382 static int experimental_loose_object(unsigned char *map)
1384 unsigned int word;
1387 * We must determine if the buffer contains the standard
1388 * zlib-deflated stream or the experimental format based
1389 * on the in-pack object format. Compare the header byte
1390 * for each format:
1392 * RFC1950 zlib w/ deflate : 0www1000 : 0 <= www <= 7
1393 * Experimental pack-based : Stttssss : ttt = 1,2,3,4
1395 * If bit 7 is clear and bits 0-3 equal 8, the buffer MUST be
1396 * in standard loose-object format, UNLESS it is a Git-pack
1397 * format object *exactly* 8 bytes in size when inflated.
1399 * However, RFC1950 also specifies that the 1st 16-bit word
1400 * must be divisible by 31 - this checksum tells us our buffer
1401 * is in the standard format, giving a false positive only if
1402 * the 1st word of the Git-pack format object happens to be
1403 * divisible by 31, ie:
1404 * ((byte0 * 256) + byte1) % 31 = 0
1405 * => 0ttt10000www1000 % 31 = 0
1407 * As it happens, this case can only arise for www=3 & ttt=1
1408 * - ie, a Commit object, which would have to be 8 bytes in
1409 * size. As no Commit can be that small, we find that the
1410 * combination of these two criteria (bitmask & checksum)
1411 * can always correctly determine the buffer format.
1413 word = (map[0] << 8) + map[1];
1414 if ((map[0] & 0x8F) == 0x08 && !(word % 31))
1415 return 0;
1416 else
1417 return 1;
1420 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1421 unsigned long len, enum object_type *type, unsigned long *sizep)
1423 unsigned shift;
1424 unsigned long size, c;
1425 unsigned long used = 0;
1427 c = buf[used++];
1428 *type = (c >> 4) & 7;
1429 size = c & 15;
1430 shift = 4;
1431 while (c & 0x80) {
1432 if (len <= used || bitsizeof(long) <= shift) {
1433 error("bad object header");
1434 size = used = 0;
1435 break;
1437 c = buf[used++];
1438 size += (c & 0x7f) << shift;
1439 shift += 7;
1441 *sizep = size;
1442 return used;
1445 int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1447 unsigned long size, used;
1448 static const char valid_loose_object_type[8] = {
1449 0, /* OBJ_EXT */
1450 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1451 0, /* "delta" and others are invalid in a loose object */
1453 enum object_type type;
1455 /* Get the data stream */
1456 memset(stream, 0, sizeof(*stream));
1457 stream->next_in = map;
1458 stream->avail_in = mapsize;
1459 stream->next_out = buffer;
1460 stream->avail_out = bufsiz;
1462 if (experimental_loose_object(map)) {
1464 * The old experimental format we no longer produce;
1465 * we can still read it.
1467 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1468 if (!used || !valid_loose_object_type[type])
1469 return -1;
1470 map += used;
1471 mapsize -= used;
1473 /* Set up the stream for the rest.. */
1474 stream->next_in = map;
1475 stream->avail_in = mapsize;
1476 git_inflate_init(stream);
1478 /* And generate the fake traditional header */
1479 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1480 typename(type), size);
1481 return 0;
1483 git_inflate_init(stream);
1484 return git_inflate(stream, 0);
1487 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1489 int bytes = strlen(buffer) + 1;
1490 unsigned char *buf = xmallocz(size);
1491 unsigned long n;
1492 int status = Z_OK;
1494 n = stream->total_out - bytes;
1495 if (n > size)
1496 n = size;
1497 memcpy(buf, (char *) buffer + bytes, n);
1498 bytes = n;
1499 if (bytes <= size) {
1501 * The above condition must be (bytes <= size), not
1502 * (bytes < size). In other words, even though we
1503 * expect no more output and set avail_out to zero,
1504 * the input zlib stream may have bytes that express
1505 * "this concludes the stream", and we *do* want to
1506 * eat that input.
1508 * Otherwise we would not be able to test that we
1509 * consumed all the input to reach the expected size;
1510 * we also want to check that zlib tells us that all
1511 * went well with status == Z_STREAM_END at the end.
1513 stream->next_out = buf + bytes;
1514 stream->avail_out = size - bytes;
1515 while (status == Z_OK)
1516 status = git_inflate(stream, Z_FINISH);
1518 if (status == Z_STREAM_END && !stream->avail_in) {
1519 git_inflate_end(stream);
1520 return buf;
1523 if (status < 0)
1524 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1525 else if (stream->avail_in)
1526 error("garbage at end of loose object '%s'",
1527 sha1_to_hex(sha1));
1528 free(buf);
1529 return NULL;
1533 * We used to just use "sscanf()", but that's actually way
1534 * too permissive for what we want to check. So do an anal
1535 * object header parse by hand.
1537 int parse_sha1_header(const char *hdr, unsigned long *sizep)
1539 char type[10];
1540 int i;
1541 unsigned long size;
1544 * The type can be at most ten bytes (including the
1545 * terminating '\0' that we add), and is followed by
1546 * a space.
1548 i = 0;
1549 for (;;) {
1550 char c = *hdr++;
1551 if (c == ' ')
1552 break;
1553 type[i++] = c;
1554 if (i >= sizeof(type))
1555 return -1;
1557 type[i] = 0;
1560 * The length must follow immediately, and be in canonical
1561 * decimal format (ie "010" is not valid).
1563 size = *hdr++ - '0';
1564 if (size > 9)
1565 return -1;
1566 if (size) {
1567 for (;;) {
1568 unsigned long c = *hdr - '0';
1569 if (c > 9)
1570 break;
1571 hdr++;
1572 size = size * 10 + c;
1575 *sizep = size;
1578 * The length must be followed by a zero byte
1580 return *hdr ? -1 : type_from_string(type);
1583 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1585 int ret;
1586 git_zstream stream;
1587 char hdr[8192];
1589 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1590 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1591 return NULL;
1593 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1596 unsigned long get_size_from_delta(struct packed_git *p,
1597 struct pack_window **w_curs,
1598 off_t curpos)
1600 const unsigned char *data;
1601 unsigned char delta_head[20], *in;
1602 git_zstream stream;
1603 int st;
1605 memset(&stream, 0, sizeof(stream));
1606 stream.next_out = delta_head;
1607 stream.avail_out = sizeof(delta_head);
1609 git_inflate_init(&stream);
1610 do {
1611 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1612 stream.next_in = in;
1613 st = git_inflate(&stream, Z_FINISH);
1614 curpos += stream.next_in - in;
1615 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1616 stream.total_out < sizeof(delta_head));
1617 git_inflate_end(&stream);
1618 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1619 error("delta data unpack-initial failed");
1620 return 0;
1623 /* Examine the initial part of the delta to figure out
1624 * the result size.
1626 data = delta_head;
1628 /* ignore base size */
1629 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1631 /* Read the result size */
1632 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1635 static off_t get_delta_base(struct packed_git *p,
1636 struct pack_window **w_curs,
1637 off_t *curpos,
1638 enum object_type type,
1639 off_t delta_obj_offset)
1641 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1642 off_t base_offset;
1644 /* use_pack() assured us we have [base_info, base_info + 20)
1645 * as a range that we can look at without walking off the
1646 * end of the mapped window. Its actually the hash size
1647 * that is assured. An OFS_DELTA longer than the hash size
1648 * is stupid, as then a REF_DELTA would be smaller to store.
1650 if (type == OBJ_OFS_DELTA) {
1651 unsigned used = 0;
1652 unsigned char c = base_info[used++];
1653 base_offset = c & 127;
1654 while (c & 128) {
1655 base_offset += 1;
1656 if (!base_offset || MSB(base_offset, 7))
1657 return 0; /* overflow */
1658 c = base_info[used++];
1659 base_offset = (base_offset << 7) + (c & 127);
1661 base_offset = delta_obj_offset - base_offset;
1662 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1663 return 0; /* out of bound */
1664 *curpos += used;
1665 } else if (type == OBJ_REF_DELTA) {
1666 /* The base entry _must_ be in the same pack */
1667 base_offset = find_pack_entry_one(base_info, p);
1668 *curpos += 20;
1669 } else
1670 die("I am totally screwed");
1671 return base_offset;
1674 int unpack_object_header(struct packed_git *p,
1675 struct pack_window **w_curs,
1676 off_t *curpos,
1677 unsigned long *sizep)
1679 unsigned char *base;
1680 unsigned long left;
1681 unsigned long used;
1682 enum object_type type;
1684 /* use_pack() assures us we have [base, base + 20) available
1685 * as a range that we can look at. (Its actually the hash
1686 * size that is assured.) With our object header encoding
1687 * the maximum deflated object size is 2^137, which is just
1688 * insane, so we know won't exceed what we have been given.
1690 base = use_pack(p, w_curs, *curpos, &left);
1691 used = unpack_object_header_buffer(base, left, &type, sizep);
1692 if (!used) {
1693 type = OBJ_BAD;
1694 } else
1695 *curpos += used;
1697 return type;
1700 static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1702 int type;
1703 struct revindex_entry *revidx;
1704 const unsigned char *sha1;
1705 revidx = find_pack_revindex(p, obj_offset);
1706 if (!revidx)
1707 return OBJ_BAD;
1708 sha1 = nth_packed_object_sha1(p, revidx->nr);
1709 mark_bad_packed_object(p, sha1);
1710 type = sha1_object_info(sha1, NULL);
1711 if (type <= OBJ_NONE)
1712 return OBJ_BAD;
1713 return type;
1716 #define POI_STACK_PREALLOC 64
1718 static enum object_type packed_to_object_type(struct packed_git *p,
1719 off_t obj_offset,
1720 enum object_type type,
1721 struct pack_window **w_curs,
1722 off_t curpos)
1724 off_t small_poi_stack[POI_STACK_PREALLOC];
1725 off_t *poi_stack = small_poi_stack;
1726 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1728 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1729 off_t base_offset;
1730 unsigned long size;
1731 /* Push the object we're going to leave behind */
1732 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1733 poi_stack_alloc = alloc_nr(poi_stack_nr);
1734 poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
1735 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1736 } else {
1737 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1739 poi_stack[poi_stack_nr++] = obj_offset;
1740 /* If parsing the base offset fails, just unwind */
1741 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1742 if (!base_offset)
1743 goto unwind;
1744 curpos = obj_offset = base_offset;
1745 type = unpack_object_header(p, w_curs, &curpos, &size);
1746 if (type <= OBJ_NONE) {
1747 /* If getting the base itself fails, we first
1748 * retry the base, otherwise unwind */
1749 type = retry_bad_packed_offset(p, base_offset);
1750 if (type > OBJ_NONE)
1751 goto out;
1752 goto unwind;
1756 switch (type) {
1757 case OBJ_BAD:
1758 case OBJ_COMMIT:
1759 case OBJ_TREE:
1760 case OBJ_BLOB:
1761 case OBJ_TAG:
1762 break;
1763 default:
1764 error("unknown object type %i at offset %"PRIuMAX" in %s",
1765 type, (uintmax_t)obj_offset, p->pack_name);
1766 type = OBJ_BAD;
1769 out:
1770 if (poi_stack != small_poi_stack)
1771 free(poi_stack);
1772 return type;
1774 unwind:
1775 while (poi_stack_nr) {
1776 obj_offset = poi_stack[--poi_stack_nr];
1777 type = retry_bad_packed_offset(p, obj_offset);
1778 if (type > OBJ_NONE)
1779 goto out;
1781 type = OBJ_BAD;
1782 goto out;
1785 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1786 struct object_info *oi)
1788 struct pack_window *w_curs = NULL;
1789 unsigned long size;
1790 off_t curpos = obj_offset;
1791 enum object_type type;
1794 * We always get the representation type, but only convert it to
1795 * a "real" type later if the caller is interested.
1797 type = unpack_object_header(p, &w_curs, &curpos, &size);
1799 if (oi->sizep) {
1800 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1801 off_t tmp_pos = curpos;
1802 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1803 type, obj_offset);
1804 if (!base_offset) {
1805 type = OBJ_BAD;
1806 goto out;
1808 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1809 if (*oi->sizep == 0) {
1810 type = OBJ_BAD;
1811 goto out;
1813 } else {
1814 *oi->sizep = size;
1818 if (oi->disk_sizep) {
1819 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1820 *oi->disk_sizep = revidx[1].offset - obj_offset;
1823 if (oi->typep) {
1824 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
1825 if (*oi->typep < 0) {
1826 type = OBJ_BAD;
1827 goto out;
1831 out:
1832 unuse_pack(&w_curs);
1833 return type;
1836 static void *unpack_compressed_entry(struct packed_git *p,
1837 struct pack_window **w_curs,
1838 off_t curpos,
1839 unsigned long size)
1841 int st;
1842 git_zstream stream;
1843 unsigned char *buffer, *in;
1845 buffer = xmallocz(size);
1846 memset(&stream, 0, sizeof(stream));
1847 stream.next_out = buffer;
1848 stream.avail_out = size + 1;
1850 git_inflate_init(&stream);
1851 do {
1852 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1853 stream.next_in = in;
1854 st = git_inflate(&stream, Z_FINISH);
1855 if (!stream.avail_out)
1856 break; /* the payload is larger than it should be */
1857 curpos += stream.next_in - in;
1858 } while (st == Z_OK || st == Z_BUF_ERROR);
1859 git_inflate_end(&stream);
1860 if ((st != Z_STREAM_END) || stream.total_out != size) {
1861 free(buffer);
1862 return NULL;
1865 return buffer;
1868 #define MAX_DELTA_CACHE (256)
1870 static size_t delta_base_cached;
1872 static struct delta_base_cache_lru_list {
1873 struct delta_base_cache_lru_list *prev;
1874 struct delta_base_cache_lru_list *next;
1875 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1877 static struct delta_base_cache_entry {
1878 struct delta_base_cache_lru_list lru;
1879 void *data;
1880 struct packed_git *p;
1881 off_t base_offset;
1882 unsigned long size;
1883 enum object_type type;
1884 } delta_base_cache[MAX_DELTA_CACHE];
1886 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1888 unsigned long hash;
1890 hash = (unsigned long)p + (unsigned long)base_offset;
1891 hash += (hash >> 8) + (hash >> 16);
1892 return hash % MAX_DELTA_CACHE;
1895 static struct delta_base_cache_entry *
1896 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1898 unsigned long hash = pack_entry_hash(p, base_offset);
1899 return delta_base_cache + hash;
1902 static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
1903 struct packed_git *p, off_t base_offset)
1905 return (ent->data && ent->p == p && ent->base_offset == base_offset);
1908 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1910 struct delta_base_cache_entry *ent;
1911 ent = get_delta_base_cache_entry(p, base_offset);
1912 return eq_delta_base_cache_entry(ent, p, base_offset);
1915 static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1917 ent->data = NULL;
1918 ent->lru.next->prev = ent->lru.prev;
1919 ent->lru.prev->next = ent->lru.next;
1920 delta_base_cached -= ent->size;
1923 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1924 unsigned long *base_size, enum object_type *type, int keep_cache)
1926 struct delta_base_cache_entry *ent;
1927 void *ret;
1929 ent = get_delta_base_cache_entry(p, base_offset);
1931 if (!eq_delta_base_cache_entry(ent, p, base_offset))
1932 return unpack_entry(p, base_offset, type, base_size);
1934 ret = ent->data;
1936 if (!keep_cache)
1937 clear_delta_base_cache_entry(ent);
1938 else
1939 ret = xmemdupz(ent->data, ent->size);
1940 *type = ent->type;
1941 *base_size = ent->size;
1942 return ret;
1945 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1947 if (ent->data) {
1948 free(ent->data);
1949 ent->data = NULL;
1950 ent->lru.next->prev = ent->lru.prev;
1951 ent->lru.prev->next = ent->lru.next;
1952 delta_base_cached -= ent->size;
1956 void clear_delta_base_cache(void)
1958 unsigned long p;
1959 for (p = 0; p < MAX_DELTA_CACHE; p++)
1960 release_delta_base_cache(&delta_base_cache[p]);
1963 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1964 void *base, unsigned long base_size, enum object_type type)
1966 unsigned long hash = pack_entry_hash(p, base_offset);
1967 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1968 struct delta_base_cache_lru_list *lru;
1970 release_delta_base_cache(ent);
1971 delta_base_cached += base_size;
1973 for (lru = delta_base_cache_lru.next;
1974 delta_base_cached > delta_base_cache_limit
1975 && lru != &delta_base_cache_lru;
1976 lru = lru->next) {
1977 struct delta_base_cache_entry *f = (void *)lru;
1978 if (f->type == OBJ_BLOB)
1979 release_delta_base_cache(f);
1981 for (lru = delta_base_cache_lru.next;
1982 delta_base_cached > delta_base_cache_limit
1983 && lru != &delta_base_cache_lru;
1984 lru = lru->next) {
1985 struct delta_base_cache_entry *f = (void *)lru;
1986 release_delta_base_cache(f);
1989 ent->p = p;
1990 ent->base_offset = base_offset;
1991 ent->type = type;
1992 ent->data = base;
1993 ent->size = base_size;
1994 ent->lru.next = &delta_base_cache_lru;
1995 ent->lru.prev = delta_base_cache_lru.prev;
1996 delta_base_cache_lru.prev->next = &ent->lru;
1997 delta_base_cache_lru.prev = &ent->lru;
2000 static void *read_object(const unsigned char *sha1, enum object_type *type,
2001 unsigned long *size);
2003 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2005 static FILE *log_file;
2007 if (!log_pack_access)
2008 log_pack_access = getenv("GIT_TRACE_PACK_ACCESS");
2009 if (!log_pack_access)
2010 log_pack_access = no_log_pack_access;
2011 if (log_pack_access == no_log_pack_access)
2012 return;
2014 if (!log_file) {
2015 log_file = fopen(log_pack_access, "w");
2016 if (!log_file) {
2017 error("cannot open pack access log '%s' for writing: %s",
2018 log_pack_access, strerror(errno));
2019 log_pack_access = no_log_pack_access;
2020 return;
2023 fprintf(log_file, "%s %"PRIuMAX"\n",
2024 p->pack_name, (uintmax_t)obj_offset);
2025 fflush(log_file);
2028 int do_check_packed_object_crc;
2030 #define UNPACK_ENTRY_STACK_PREALLOC 64
2031 struct unpack_entry_stack_ent {
2032 off_t obj_offset;
2033 off_t curpos;
2034 unsigned long size;
2037 void *unpack_entry(struct packed_git *p, off_t obj_offset,
2038 enum object_type *final_type, unsigned long *final_size)
2040 struct pack_window *w_curs = NULL;
2041 off_t curpos = obj_offset;
2042 void *data = NULL;
2043 unsigned long size;
2044 enum object_type type;
2045 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2046 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2047 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2048 int base_from_cache = 0;
2050 if (log_pack_access != no_log_pack_access)
2051 write_pack_access_log(p, obj_offset);
2053 /* PHASE 1: drill down to the innermost base object */
2054 for (;;) {
2055 off_t base_offset;
2056 int i;
2057 struct delta_base_cache_entry *ent;
2059 if (do_check_packed_object_crc && p->index_version > 1) {
2060 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2061 unsigned long len = revidx[1].offset - obj_offset;
2062 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2063 const unsigned char *sha1 =
2064 nth_packed_object_sha1(p, revidx->nr);
2065 error("bad packed object CRC for %s",
2066 sha1_to_hex(sha1));
2067 mark_bad_packed_object(p, sha1);
2068 unuse_pack(&w_curs);
2069 return NULL;
2073 ent = get_delta_base_cache_entry(p, curpos);
2074 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2075 type = ent->type;
2076 data = ent->data;
2077 size = ent->size;
2078 clear_delta_base_cache_entry(ent);
2079 base_from_cache = 1;
2080 break;
2083 type = unpack_object_header(p, &w_curs, &curpos, &size);
2084 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2085 break;
2087 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2088 if (!base_offset) {
2089 error("failed to validate delta base reference "
2090 "at offset %"PRIuMAX" from %s",
2091 (uintmax_t)curpos, p->pack_name);
2092 /* bail to phase 2, in hopes of recovery */
2093 data = NULL;
2094 break;
2097 /* push object, proceed to base */
2098 if (delta_stack_nr >= delta_stack_alloc
2099 && delta_stack == small_delta_stack) {
2100 delta_stack_alloc = alloc_nr(delta_stack_nr);
2101 delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
2102 memcpy(delta_stack, small_delta_stack,
2103 sizeof(*delta_stack)*delta_stack_nr);
2104 } else {
2105 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2107 i = delta_stack_nr++;
2108 delta_stack[i].obj_offset = obj_offset;
2109 delta_stack[i].curpos = curpos;
2110 delta_stack[i].size = size;
2112 curpos = obj_offset = base_offset;
2115 /* PHASE 2: handle the base */
2116 switch (type) {
2117 case OBJ_OFS_DELTA:
2118 case OBJ_REF_DELTA:
2119 if (data)
2120 die("BUG in unpack_entry: left loop at a valid delta");
2121 break;
2122 case OBJ_COMMIT:
2123 case OBJ_TREE:
2124 case OBJ_BLOB:
2125 case OBJ_TAG:
2126 if (!base_from_cache)
2127 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2128 break;
2129 default:
2130 data = NULL;
2131 error("unknown object type %i at offset %"PRIuMAX" in %s",
2132 type, (uintmax_t)obj_offset, p->pack_name);
2135 /* PHASE 3: apply deltas in order */
2137 /* invariants:
2138 * 'data' holds the base data, or NULL if there was corruption
2140 while (delta_stack_nr) {
2141 void *delta_data;
2142 void *base = data;
2143 unsigned long delta_size, base_size = size;
2144 int i;
2146 data = NULL;
2148 if (base)
2149 add_delta_base_cache(p, obj_offset, base, base_size, type);
2151 if (!base) {
2153 * We're probably in deep shit, but let's try to fetch
2154 * the required base anyway from another pack or loose.
2155 * This is costly but should happen only in the presence
2156 * of a corrupted pack, and is better than failing outright.
2158 struct revindex_entry *revidx;
2159 const unsigned char *base_sha1;
2160 revidx = find_pack_revindex(p, obj_offset);
2161 if (revidx) {
2162 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2163 error("failed to read delta base object %s"
2164 " at offset %"PRIuMAX" from %s",
2165 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2166 p->pack_name);
2167 mark_bad_packed_object(p, base_sha1);
2168 base = read_object(base_sha1, &type, &base_size);
2172 i = --delta_stack_nr;
2173 obj_offset = delta_stack[i].obj_offset;
2174 curpos = delta_stack[i].curpos;
2175 delta_size = delta_stack[i].size;
2177 if (!base)
2178 continue;
2180 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2182 if (!delta_data) {
2183 error("failed to unpack compressed delta "
2184 "at offset %"PRIuMAX" from %s",
2185 (uintmax_t)curpos, p->pack_name);
2186 data = NULL;
2187 continue;
2190 data = patch_delta(base, base_size,
2191 delta_data, delta_size,
2192 &size);
2195 * We could not apply the delta; warn the user, but keep going.
2196 * Our failure will be noticed either in the next iteration of
2197 * the loop, or if this is the final delta, in the caller when
2198 * we return NULL. Those code paths will take care of making
2199 * a more explicit warning and retrying with another copy of
2200 * the object.
2202 if (!data)
2203 error("failed to apply delta");
2205 free(delta_data);
2208 *final_type = type;
2209 *final_size = size;
2211 unuse_pack(&w_curs);
2212 return data;
2215 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2216 uint32_t n)
2218 const unsigned char *index = p->index_data;
2219 if (!index) {
2220 if (open_pack_index(p))
2221 return NULL;
2222 index = p->index_data;
2224 if (n >= p->num_objects)
2225 return NULL;
2226 index += 4 * 256;
2227 if (p->index_version == 1) {
2228 return index + 24 * n + 4;
2229 } else {
2230 index += 8;
2231 return index + 20 * n;
2235 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2237 const unsigned char *index = p->index_data;
2238 index += 4 * 256;
2239 if (p->index_version == 1) {
2240 return ntohl(*((uint32_t *)(index + 24 * n)));
2241 } else {
2242 uint32_t off;
2243 index += 8 + p->num_objects * (20 + 4);
2244 off = ntohl(*((uint32_t *)(index + 4 * n)));
2245 if (!(off & 0x80000000))
2246 return off;
2247 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2248 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2249 ntohl(*((uint32_t *)(index + 4)));
2253 off_t find_pack_entry_one(const unsigned char *sha1,
2254 struct packed_git *p)
2256 const uint32_t *level1_ofs = p->index_data;
2257 const unsigned char *index = p->index_data;
2258 unsigned hi, lo, stride;
2259 static int use_lookup = -1;
2260 static int debug_lookup = -1;
2262 if (debug_lookup < 0)
2263 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2265 if (!index) {
2266 if (open_pack_index(p))
2267 return 0;
2268 level1_ofs = p->index_data;
2269 index = p->index_data;
2271 if (p->index_version > 1) {
2272 level1_ofs += 2;
2273 index += 8;
2275 index += 4 * 256;
2276 hi = ntohl(level1_ofs[*sha1]);
2277 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2278 if (p->index_version > 1) {
2279 stride = 20;
2280 } else {
2281 stride = 24;
2282 index += 4;
2285 if (debug_lookup)
2286 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2287 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2289 if (use_lookup < 0)
2290 use_lookup = !!getenv("GIT_USE_LOOKUP");
2291 if (use_lookup) {
2292 int pos = sha1_entry_pos(index, stride, 0,
2293 lo, hi, p->num_objects, sha1);
2294 if (pos < 0)
2295 return 0;
2296 return nth_packed_object_offset(p, pos);
2299 do {
2300 unsigned mi = (lo + hi) / 2;
2301 int cmp = hashcmp(index + mi * stride, sha1);
2303 if (debug_lookup)
2304 printf("lo %u hi %u rg %u mi %u\n",
2305 lo, hi, hi - lo, mi);
2306 if (!cmp)
2307 return nth_packed_object_offset(p, mi);
2308 if (cmp > 0)
2309 hi = mi;
2310 else
2311 lo = mi+1;
2312 } while (lo < hi);
2313 return 0;
2316 int is_pack_valid(struct packed_git *p)
2318 /* An already open pack is known to be valid. */
2319 if (p->pack_fd != -1)
2320 return 1;
2322 /* If the pack has one window completely covering the
2323 * file size, the pack is known to be valid even if
2324 * the descriptor is not currently open.
2326 if (p->windows) {
2327 struct pack_window *w = p->windows;
2329 if (!w->offset && w->len == p->pack_size)
2330 return 1;
2333 /* Force the pack to open to prove its valid. */
2334 return !open_packed_git(p);
2337 static int fill_pack_entry(const unsigned char *sha1,
2338 struct pack_entry *e,
2339 struct packed_git *p)
2341 off_t offset;
2343 if (p->num_bad_objects) {
2344 unsigned i;
2345 for (i = 0; i < p->num_bad_objects; i++)
2346 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2347 return 0;
2350 offset = find_pack_entry_one(sha1, p);
2351 if (!offset)
2352 return 0;
2355 * We are about to tell the caller where they can locate the
2356 * requested object. We better make sure the packfile is
2357 * still here and can be accessed before supplying that
2358 * answer, as it may have been deleted since the index was
2359 * loaded!
2361 if (!is_pack_valid(p)) {
2362 warning("packfile %s cannot be accessed", p->pack_name);
2363 return 0;
2365 e->offset = offset;
2366 e->p = p;
2367 hashcpy(e->sha1, sha1);
2368 return 1;
2371 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2373 struct packed_git *p;
2375 prepare_packed_git();
2376 if (!packed_git)
2377 return 0;
2379 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2380 return 1;
2382 for (p = packed_git; p; p = p->next) {
2383 if (p == last_found_pack || !fill_pack_entry(sha1, e, p))
2384 continue;
2386 last_found_pack = p;
2387 return 1;
2389 return 0;
2392 struct packed_git *find_sha1_pack(const unsigned char *sha1,
2393 struct packed_git *packs)
2395 struct packed_git *p;
2397 for (p = packs; p; p = p->next) {
2398 if (find_pack_entry_one(sha1, p))
2399 return p;
2401 return NULL;
2405 static int sha1_loose_object_info(const unsigned char *sha1,
2406 struct object_info *oi)
2408 int status;
2409 unsigned long mapsize, size;
2410 void *map;
2411 git_zstream stream;
2412 char hdr[32];
2415 * If we don't care about type or size, then we don't
2416 * need to look inside the object at all.
2418 if (!oi->typep && !oi->sizep) {
2419 if (oi->disk_sizep) {
2420 struct stat st;
2421 if (stat_sha1_file(sha1, &st) < 0)
2422 return -1;
2423 *oi->disk_sizep = st.st_size;
2425 return 0;
2428 map = map_sha1_file(sha1, &mapsize);
2429 if (!map)
2430 return -1;
2431 if (oi->disk_sizep)
2432 *oi->disk_sizep = mapsize;
2433 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2434 status = error("unable to unpack %s header",
2435 sha1_to_hex(sha1));
2436 else if ((status = parse_sha1_header(hdr, &size)) < 0)
2437 status = error("unable to parse %s header", sha1_to_hex(sha1));
2438 else if (oi->sizep)
2439 *oi->sizep = size;
2440 git_inflate_end(&stream);
2441 munmap(map, mapsize);
2442 if (oi->typep)
2443 *oi->typep = status;
2444 return 0;
2447 /* returns enum object_type or negative */
2448 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi)
2450 struct cached_object *co;
2451 struct pack_entry e;
2452 int rtype;
2454 co = find_cached_object(sha1);
2455 if (co) {
2456 if (oi->typep)
2457 *(oi->typep) = co->type;
2458 if (oi->sizep)
2459 *(oi->sizep) = co->size;
2460 if (oi->disk_sizep)
2461 *(oi->disk_sizep) = 0;
2462 oi->whence = OI_CACHED;
2463 return 0;
2466 if (!find_pack_entry(sha1, &e)) {
2467 /* Most likely it's a loose object. */
2468 if (!sha1_loose_object_info(sha1, oi)) {
2469 oi->whence = OI_LOOSE;
2470 return 0;
2473 /* Not a loose object; someone else may have just packed it. */
2474 reprepare_packed_git();
2475 if (!find_pack_entry(sha1, &e))
2476 return -1;
2479 rtype = packed_object_info(e.p, e.offset, oi);
2480 if (rtype < 0) {
2481 mark_bad_packed_object(e.p, sha1);
2482 return sha1_object_info_extended(sha1, oi);
2483 } else if (in_delta_base_cache(e.p, e.offset)) {
2484 oi->whence = OI_DBCACHED;
2485 } else {
2486 oi->whence = OI_PACKED;
2487 oi->u.packed.offset = e.offset;
2488 oi->u.packed.pack = e.p;
2489 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2490 rtype == OBJ_OFS_DELTA);
2493 return 0;
2496 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2498 enum object_type type;
2499 struct object_info oi = {NULL};
2501 oi.typep = &type;
2502 oi.sizep = sizep;
2503 if (sha1_object_info_extended(sha1, &oi) < 0)
2504 return -1;
2505 return type;
2508 static void *read_packed_sha1(const unsigned char *sha1,
2509 enum object_type *type, unsigned long *size)
2511 struct pack_entry e;
2512 void *data;
2514 if (!find_pack_entry(sha1, &e))
2515 return NULL;
2516 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2517 if (!data) {
2519 * We're probably in deep shit, but let's try to fetch
2520 * the required object anyway from another pack or loose.
2521 * This should happen only in the presence of a corrupted
2522 * pack, and is better than failing outright.
2524 error("failed to read object %s at offset %"PRIuMAX" from %s",
2525 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2526 mark_bad_packed_object(e.p, sha1);
2527 data = read_object(sha1, type, size);
2529 return data;
2532 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2533 unsigned char *sha1)
2535 struct cached_object *co;
2537 hash_sha1_file(buf, len, typename(type), sha1);
2538 if (has_sha1_file(sha1) || find_cached_object(sha1))
2539 return 0;
2540 if (cached_object_alloc <= cached_object_nr) {
2541 cached_object_alloc = alloc_nr(cached_object_alloc);
2542 cached_objects = xrealloc(cached_objects,
2543 sizeof(*cached_objects) *
2544 cached_object_alloc);
2546 co = &cached_objects[cached_object_nr++];
2547 co->size = len;
2548 co->type = type;
2549 co->buf = xmalloc(len);
2550 memcpy(co->buf, buf, len);
2551 hashcpy(co->sha1, sha1);
2552 return 0;
2555 static void *read_object(const unsigned char *sha1, enum object_type *type,
2556 unsigned long *size)
2558 unsigned long mapsize;
2559 void *map, *buf;
2560 struct cached_object *co;
2562 co = find_cached_object(sha1);
2563 if (co) {
2564 *type = co->type;
2565 *size = co->size;
2566 return xmemdupz(co->buf, co->size);
2569 buf = read_packed_sha1(sha1, type, size);
2570 if (buf)
2571 return buf;
2572 map = map_sha1_file(sha1, &mapsize);
2573 if (map) {
2574 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2575 munmap(map, mapsize);
2576 return buf;
2578 reprepare_packed_git();
2579 return read_packed_sha1(sha1, type, size);
2583 * This function dies on corrupt objects; the callers who want to
2584 * deal with them should arrange to call read_object() and give error
2585 * messages themselves.
2587 void *read_sha1_file_extended(const unsigned char *sha1,
2588 enum object_type *type,
2589 unsigned long *size,
2590 unsigned flag)
2592 void *data;
2593 char *path;
2594 const struct packed_git *p;
2595 const unsigned char *repl = (flag & READ_SHA1_FILE_REPLACE)
2596 ? lookup_replace_object(sha1) : sha1;
2598 errno = 0;
2599 data = read_object(repl, type, size);
2600 if (data)
2601 return data;
2603 if (errno && errno != ENOENT)
2604 die_errno("failed to read object %s", sha1_to_hex(sha1));
2606 /* die if we replaced an object with one that does not exist */
2607 if (repl != sha1)
2608 die("replacement %s not found for %s",
2609 sha1_to_hex(repl), sha1_to_hex(sha1));
2611 if (has_loose_object(repl)) {
2612 path = sha1_file_name(sha1);
2613 die("loose object %s (stored in %s) is corrupt",
2614 sha1_to_hex(repl), path);
2617 if ((p = has_packed_and_bad(repl)) != NULL)
2618 die("packed object %s (stored in %s) is corrupt",
2619 sha1_to_hex(repl), p->pack_name);
2621 return NULL;
2624 void *read_object_with_reference(const unsigned char *sha1,
2625 const char *required_type_name,
2626 unsigned long *size,
2627 unsigned char *actual_sha1_return)
2629 enum object_type type, required_type;
2630 void *buffer;
2631 unsigned long isize;
2632 unsigned char actual_sha1[20];
2634 required_type = type_from_string(required_type_name);
2635 hashcpy(actual_sha1, sha1);
2636 while (1) {
2637 int ref_length = -1;
2638 const char *ref_type = NULL;
2640 buffer = read_sha1_file(actual_sha1, &type, &isize);
2641 if (!buffer)
2642 return NULL;
2643 if (type == required_type) {
2644 *size = isize;
2645 if (actual_sha1_return)
2646 hashcpy(actual_sha1_return, actual_sha1);
2647 return buffer;
2649 /* Handle references */
2650 else if (type == OBJ_COMMIT)
2651 ref_type = "tree ";
2652 else if (type == OBJ_TAG)
2653 ref_type = "object ";
2654 else {
2655 free(buffer);
2656 return NULL;
2658 ref_length = strlen(ref_type);
2660 if (ref_length + 40 > isize ||
2661 memcmp(buffer, ref_type, ref_length) ||
2662 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2663 free(buffer);
2664 return NULL;
2666 free(buffer);
2667 /* Now we have the ID of the referred-to object in
2668 * actual_sha1. Check again. */
2672 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2673 const char *type, unsigned char *sha1,
2674 char *hdr, int *hdrlen)
2676 git_SHA_CTX c;
2678 /* Generate the header */
2679 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2681 /* Sha1.. */
2682 git_SHA1_Init(&c);
2683 git_SHA1_Update(&c, hdr, *hdrlen);
2684 git_SHA1_Update(&c, buf, len);
2685 git_SHA1_Final(sha1, &c);
2689 * Move the just written object into its final resting place.
2690 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2691 * "moving" is only a part of what it does, when no patch between
2692 * master to pu changes the call sites of this function.
2694 int move_temp_to_file(const char *tmpfile, const char *filename)
2696 int ret = 0;
2698 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2699 goto try_rename;
2700 else if (link(tmpfile, filename))
2701 ret = errno;
2704 * Coda hack - coda doesn't like cross-directory links,
2705 * so we fall back to a rename, which will mean that it
2706 * won't be able to check collisions, but that's not a
2707 * big deal.
2709 * The same holds for FAT formatted media.
2711 * When this succeeds, we just return. We have nothing
2712 * left to unlink.
2714 if (ret && ret != EEXIST) {
2715 try_rename:
2716 if (!rename(tmpfile, filename))
2717 goto out;
2718 ret = errno;
2720 unlink_or_warn(tmpfile);
2721 if (ret) {
2722 if (ret != EEXIST) {
2723 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
2725 /* FIXME!!! Collision check here ? */
2728 out:
2729 if (adjust_shared_perm(filename))
2730 return error("unable to set permission to '%s'", filename);
2731 return 0;
2734 static int write_buffer(int fd, const void *buf, size_t len)
2736 if (write_in_full(fd, buf, len) < 0)
2737 return error("file write error (%s)", strerror(errno));
2738 return 0;
2741 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2742 unsigned char *sha1)
2744 char hdr[32];
2745 int hdrlen;
2746 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2747 return 0;
2750 /* Finalize a file on disk, and close it. */
2751 static void close_sha1_file(int fd)
2753 if (fsync_object_files)
2754 fsync_or_die(fd, "sha1 file");
2755 if (close(fd) != 0)
2756 die_errno("error when closing sha1 file");
2759 /* Size of directory component, including the ending '/' */
2760 static inline int directory_size(const char *filename)
2762 const char *s = strrchr(filename, '/');
2763 if (!s)
2764 return 0;
2765 return s - filename + 1;
2769 * This creates a temporary file in the same directory as the final
2770 * 'filename'
2772 * We want to avoid cross-directory filename renames, because those
2773 * can have problems on various filesystems (FAT, NFS, Coda).
2775 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2777 int fd, dirlen = directory_size(filename);
2779 if (dirlen + 20 > bufsiz) {
2780 errno = ENAMETOOLONG;
2781 return -1;
2783 memcpy(buffer, filename, dirlen);
2784 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2785 fd = git_mkstemp_mode(buffer, 0444);
2786 if (fd < 0 && dirlen && errno == ENOENT) {
2787 /* Make sure the directory exists */
2788 memcpy(buffer, filename, dirlen);
2789 buffer[dirlen-1] = 0;
2790 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2791 return -1;
2793 /* Try again */
2794 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2795 fd = git_mkstemp_mode(buffer, 0444);
2797 return fd;
2800 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2801 const void *buf, unsigned long len, time_t mtime)
2803 int fd, ret;
2804 unsigned char compressed[4096];
2805 git_zstream stream;
2806 git_SHA_CTX c;
2807 unsigned char parano_sha1[20];
2808 char *filename;
2809 static char tmp_file[PATH_MAX];
2811 filename = sha1_file_name(sha1);
2812 fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
2813 if (fd < 0) {
2814 if (errno == EACCES)
2815 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
2816 else
2817 return error("unable to create temporary file: %s", strerror(errno));
2820 /* Set it up */
2821 memset(&stream, 0, sizeof(stream));
2822 git_deflate_init(&stream, zlib_compression_level);
2823 stream.next_out = compressed;
2824 stream.avail_out = sizeof(compressed);
2825 git_SHA1_Init(&c);
2827 /* First header.. */
2828 stream.next_in = (unsigned char *)hdr;
2829 stream.avail_in = hdrlen;
2830 while (git_deflate(&stream, 0) == Z_OK)
2831 ; /* nothing */
2832 git_SHA1_Update(&c, hdr, hdrlen);
2834 /* Then the data itself.. */
2835 stream.next_in = (void *)buf;
2836 stream.avail_in = len;
2837 do {
2838 unsigned char *in0 = stream.next_in;
2839 ret = git_deflate(&stream, Z_FINISH);
2840 git_SHA1_Update(&c, in0, stream.next_in - in0);
2841 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2842 die("unable to write sha1 file");
2843 stream.next_out = compressed;
2844 stream.avail_out = sizeof(compressed);
2845 } while (ret == Z_OK);
2847 if (ret != Z_STREAM_END)
2848 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2849 ret = git_deflate_end_gently(&stream);
2850 if (ret != Z_OK)
2851 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2852 git_SHA1_Final(parano_sha1, &c);
2853 if (hashcmp(sha1, parano_sha1) != 0)
2854 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
2856 close_sha1_file(fd);
2858 if (mtime) {
2859 struct utimbuf utb;
2860 utb.actime = mtime;
2861 utb.modtime = mtime;
2862 if (utime(tmp_file, &utb) < 0)
2863 warning("failed utime() on %s: %s",
2864 tmp_file, strerror(errno));
2867 return move_temp_to_file(tmp_file, filename);
2870 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2872 unsigned char sha1[20];
2873 char hdr[32];
2874 int hdrlen;
2876 /* Normally if we have it in the pack then we do not bother writing
2877 * it out into .git/objects/??/?{38} file.
2879 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2880 if (returnsha1)
2881 hashcpy(returnsha1, sha1);
2882 if (has_sha1_file(sha1))
2883 return 0;
2884 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2887 int force_object_loose(const unsigned char *sha1, time_t mtime)
2889 void *buf;
2890 unsigned long len;
2891 enum object_type type;
2892 char hdr[32];
2893 int hdrlen;
2894 int ret;
2896 if (has_loose_object(sha1))
2897 return 0;
2898 buf = read_packed_sha1(sha1, &type, &len);
2899 if (!buf)
2900 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2901 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2902 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2903 free(buf);
2905 return ret;
2908 int has_pack_index(const unsigned char *sha1)
2910 struct stat st;
2911 if (stat(sha1_pack_index_name(sha1), &st))
2912 return 0;
2913 return 1;
2916 int has_sha1_pack(const unsigned char *sha1)
2918 struct pack_entry e;
2919 return find_pack_entry(sha1, &e);
2922 int has_sha1_file(const unsigned char *sha1)
2924 struct pack_entry e;
2926 if (find_pack_entry(sha1, &e))
2927 return 1;
2928 return has_loose_object(sha1);
2931 static void check_tree(const void *buf, size_t size)
2933 struct tree_desc desc;
2934 struct name_entry entry;
2936 init_tree_desc(&desc, buf, size);
2937 while (tree_entry(&desc, &entry))
2938 /* do nothing
2939 * tree_entry() will die() on malformed entries */
2943 static void check_commit(const void *buf, size_t size)
2945 struct commit c;
2946 memset(&c, 0, sizeof(c));
2947 if (parse_commit_buffer(&c, buf, size))
2948 die("corrupt commit");
2951 static void check_tag(const void *buf, size_t size)
2953 struct tag t;
2954 memset(&t, 0, sizeof(t));
2955 if (parse_tag_buffer(&t, buf, size))
2956 die("corrupt tag");
2959 static int index_mem(unsigned char *sha1, void *buf, size_t size,
2960 enum object_type type,
2961 const char *path, unsigned flags)
2963 int ret, re_allocated = 0;
2964 int write_object = flags & HASH_WRITE_OBJECT;
2966 if (!type)
2967 type = OBJ_BLOB;
2970 * Convert blobs to git internal format
2972 if ((type == OBJ_BLOB) && path) {
2973 struct strbuf nbuf = STRBUF_INIT;
2974 if (convert_to_git(path, buf, size, &nbuf,
2975 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
2976 buf = strbuf_detach(&nbuf, &size);
2977 re_allocated = 1;
2980 if (flags & HASH_FORMAT_CHECK) {
2981 if (type == OBJ_TREE)
2982 check_tree(buf, size);
2983 if (type == OBJ_COMMIT)
2984 check_commit(buf, size);
2985 if (type == OBJ_TAG)
2986 check_tag(buf, size);
2989 if (write_object)
2990 ret = write_sha1_file(buf, size, typename(type), sha1);
2991 else
2992 ret = hash_sha1_file(buf, size, typename(type), sha1);
2993 if (re_allocated)
2994 free(buf);
2995 return ret;
2998 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
2999 const char *path, unsigned flags)
3001 struct strbuf sbuf = STRBUF_INIT;
3002 int ret;
3004 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3005 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3006 else
3007 ret = -1;
3008 strbuf_release(&sbuf);
3009 return ret;
3012 #define SMALL_FILE_SIZE (32*1024)
3014 static int index_core(unsigned char *sha1, int fd, size_t size,
3015 enum object_type type, const char *path,
3016 unsigned flags)
3018 int ret;
3020 if (!size) {
3021 ret = index_mem(sha1, NULL, size, type, path, flags);
3022 } else if (size <= SMALL_FILE_SIZE) {
3023 char *buf = xmalloc(size);
3024 if (size == read_in_full(fd, buf, size))
3025 ret = index_mem(sha1, buf, size, type, path, flags);
3026 else
3027 ret = error("short read %s", strerror(errno));
3028 free(buf);
3029 } else {
3030 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3031 ret = index_mem(sha1, buf, size, type, path, flags);
3032 munmap(buf, size);
3034 return ret;
3038 * This creates one packfile per large blob unless bulk-checkin
3039 * machinery is "plugged".
3041 * This also bypasses the usual "convert-to-git" dance, and that is on
3042 * purpose. We could write a streaming version of the converting
3043 * functions and insert that before feeding the data to fast-import
3044 * (or equivalent in-core API described above). However, that is
3045 * somewhat complicated, as we do not know the size of the filter
3046 * result, which we need to know beforehand when writing a git object.
3047 * Since the primary motivation for trying to stream from the working
3048 * tree file and to avoid mmaping it in core is to deal with large
3049 * binary blobs, they generally do not want to get any conversion, and
3050 * callers should avoid this code path when filters are requested.
3052 static int index_stream(unsigned char *sha1, int fd, size_t size,
3053 enum object_type type, const char *path,
3054 unsigned flags)
3056 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3059 int index_fd(unsigned char *sha1, int fd, struct stat *st,
3060 enum object_type type, const char *path, unsigned flags)
3062 int ret;
3063 size_t size = xsize_t(st->st_size);
3065 if (!S_ISREG(st->st_mode))
3066 ret = index_pipe(sha1, fd, type, path, flags);
3067 else if (size <= big_file_threshold || type != OBJ_BLOB ||
3068 (path && would_convert_to_git(path, NULL, 0, 0)))
3069 ret = index_core(sha1, fd, size, type, path, flags);
3070 else
3071 ret = index_stream(sha1, fd, size, type, path, flags);
3072 close(fd);
3073 return ret;
3076 int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3078 int fd;
3079 struct strbuf sb = STRBUF_INIT;
3081 switch (st->st_mode & S_IFMT) {
3082 case S_IFREG:
3083 fd = open(path, O_RDONLY);
3084 if (fd < 0)
3085 return error("open(\"%s\"): %s", path,
3086 strerror(errno));
3087 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3088 return error("%s: failed to insert into database",
3089 path);
3090 break;
3091 case S_IFLNK:
3092 if (strbuf_readlink(&sb, path, st->st_size)) {
3093 char *errstr = strerror(errno);
3094 return error("readlink(\"%s\"): %s", path,
3095 errstr);
3097 if (!(flags & HASH_WRITE_OBJECT))
3098 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3099 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3100 return error("%s: failed to insert into database",
3101 path);
3102 strbuf_release(&sb);
3103 break;
3104 case S_IFDIR:
3105 return resolve_gitlink_ref(path, "HEAD", sha1);
3106 default:
3107 return error("%s: unsupported file type", path);
3109 return 0;
3112 int read_pack_header(int fd, struct pack_header *header)
3114 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3115 /* "eof before pack header was fully read" */
3116 return PH_ERROR_EOF;
3118 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3119 /* "protocol error (pack signature mismatch detected)" */
3120 return PH_ERROR_PACK_SIGNATURE;
3121 if (!pack_version_ok(header->hdr_version))
3122 /* "protocol error (pack version unsupported)" */
3123 return PH_ERROR_PROTOCOL;
3124 return 0;
3127 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3129 enum object_type type = sha1_object_info(sha1, NULL);
3130 if (type < 0)
3131 die("%s is not a valid object", sha1_to_hex(sha1));
3132 if (type != expect)
3133 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3134 typename(expect));