2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
17 #include "pack-revindex.h"
18 #include "sha1-lookup.h"
21 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
22 #define O_NOATIME 01000000
30 static unsigned long sz_fmt(size_t s
) { return (unsigned long)s
; }
33 static size_t sz_fmt(size_t s
) { return s
; }
36 const unsigned char null_sha1
[20];
38 int safe_create_leading_directories(char *path
)
40 char *pos
= path
+ offset_1st_component(path
);
44 pos
= strchr(pos
, '/');
52 if (!stat(path
, &st
)) {
54 if (!S_ISDIR(st
.st_mode
)) {
59 else if (mkdir(path
, 0777)) {
63 else if (adjust_shared_perm(path
)) {
72 int safe_create_leading_directories_const(const char *path
)
74 /* path points to cache entries, so xstrdup before messing with it */
75 char *buf
= xstrdup(path
);
76 int result
= safe_create_leading_directories(buf
);
81 static void fill_sha1_path(char *pathbuf
, const unsigned char *sha1
)
84 for (i
= 0; i
< 20; i
++) {
85 static char hex
[] = "0123456789abcdef";
86 unsigned int val
= sha1
[i
];
87 char *pos
= pathbuf
+ i
*2 + (i
> 0);
88 *pos
++ = hex
[val
>> 4];
89 *pos
= hex
[val
& 0xf];
94 * NOTE! This returns a statically allocated buffer, so you have to be
95 * careful about using it. Do an "xstrdup()" if you need to save the
98 * Also note that this returns the location for creating. Reading
99 * SHA1 file can happen from any alternate directory listed in the
100 * DB_ENVIRONMENT environment variable if it is not found in
101 * the primary object database.
103 char *sha1_file_name(const unsigned char *sha1
)
105 static char buf
[PATH_MAX
];
109 objdir
= get_object_directory();
110 len
= strlen(objdir
);
112 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
113 if (len
+ 43 > PATH_MAX
)
114 die("insanely long object directory %s", objdir
);
115 memcpy(buf
, objdir
, len
);
119 fill_sha1_path(buf
+ len
+ 1, sha1
);
123 static char *sha1_get_pack_name(const unsigned char *sha1
,
124 char **name
, char **base
, const char *which
)
126 static const char hex
[] = "0123456789abcdef";
131 const char *sha1_file_directory
= get_object_directory();
132 int len
= strlen(sha1_file_directory
);
133 *base
= xmalloc(len
+ 60);
134 sprintf(*base
, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
135 sha1_file_directory
, which
);
136 *name
= *base
+ len
+ 11;
141 for (i
= 0; i
< 20; i
++) {
142 unsigned int val
= *sha1
++;
143 *buf
++ = hex
[val
>> 4];
144 *buf
++ = hex
[val
& 0xf];
150 char *sha1_pack_name(const unsigned char *sha1
)
152 static char *name
, *base
;
154 return sha1_get_pack_name(sha1
, &name
, &base
, "pack");
157 char *sha1_pack_index_name(const unsigned char *sha1
)
159 static char *name
, *base
;
161 return sha1_get_pack_name(sha1
, &name
, &base
, "idx");
164 struct alternate_object_database
*alt_odb_list
;
165 static struct alternate_object_database
**alt_odb_tail
;
167 static void read_info_alternates(const char * alternates
, int depth
);
170 * Prepare alternate object database registry.
172 * The variable alt_odb_list points at the list of struct
173 * alternate_object_database. The elements on this list come from
174 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
175 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
176 * whose contents is similar to that environment variable but can be
177 * LF separated. Its base points at a statically allocated buffer that
178 * contains "/the/directory/corresponding/to/.git/objects/...", while
179 * its name points just after the slash at the end of ".git/objects/"
180 * in the example above, and has enough space to hold 40-byte hex
181 * SHA1, an extra slash for the first level indirection, and the
184 static int link_alt_odb_entry(const char * entry
, int len
, const char * relative_base
, int depth
)
186 const char *objdir
= get_object_directory();
187 struct alternate_object_database
*ent
;
188 struct alternate_object_database
*alt
;
189 /* 43 = 40-byte + 2 '/' + terminating NUL */
191 int entlen
= pfxlen
+ 43;
194 if (!is_absolute_path(entry
) && relative_base
) {
195 /* Relative alt-odb */
197 base_len
= strlen(relative_base
) + 1;
201 ent
= xmalloc(sizeof(*ent
) + entlen
);
203 if (!is_absolute_path(entry
) && relative_base
) {
204 memcpy(ent
->base
, relative_base
, base_len
- 1);
205 ent
->base
[base_len
- 1] = '/';
206 memcpy(ent
->base
+ base_len
, entry
, len
);
209 memcpy(ent
->base
, entry
, pfxlen
);
211 ent
->name
= ent
->base
+ pfxlen
+ 1;
212 ent
->base
[pfxlen
+ 3] = '/';
213 ent
->base
[pfxlen
] = ent
->base
[entlen
-1] = 0;
215 /* Detect cases where alternate disappeared */
216 if (!is_directory(ent
->base
)) {
217 error("object directory %s does not exist; "
218 "check .git/objects/info/alternates.",
224 /* Prevent the common mistake of listing the same
225 * thing twice, or object directory itself.
227 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
228 if (!memcmp(ent
->base
, alt
->base
, pfxlen
)) {
233 if (!memcmp(ent
->base
, objdir
, pfxlen
)) {
238 /* add the alternate entry */
240 alt_odb_tail
= &(ent
->next
);
243 /* recursively add alternates */
244 read_info_alternates(ent
->base
, depth
+ 1);
246 ent
->base
[pfxlen
] = '/';
251 static void link_alt_odb_entries(const char *alt
, const char *ep
, int sep
,
252 const char *relative_base
, int depth
)
254 const char *cp
, *last
;
257 error("%s: ignoring alternate object stores, nesting too deep.",
265 if (cp
< ep
&& *cp
== '#') {
266 while (cp
< ep
&& *cp
!= sep
)
271 while (cp
< ep
&& *cp
!= sep
)
274 if (!is_absolute_path(last
) && depth
) {
275 error("%s: ignoring relative alternate object store %s",
276 relative_base
, last
);
278 link_alt_odb_entry(last
, cp
- last
,
279 relative_base
, depth
);
282 while (cp
< ep
&& *cp
== sep
)
288 static void read_info_alternates(const char * relative_base
, int depth
)
293 const char alt_file_name
[] = "info/alternates";
294 /* Given that relative_base is no longer than PATH_MAX,
295 ensure that "path" has enough space to append "/", the
296 file name, "info/alternates", and a trailing NUL. */
297 char path
[PATH_MAX
+ 1 + sizeof alt_file_name
];
300 sprintf(path
, "%s/%s", relative_base
, alt_file_name
);
301 fd
= open(path
, O_RDONLY
);
304 if (fstat(fd
, &st
) || (st
.st_size
== 0)) {
308 mapsz
= xsize_t(st
.st_size
);
309 map
= xmmap(NULL
, mapsz
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
312 link_alt_odb_entries(map
, map
+ mapsz
, '\n', relative_base
, depth
);
317 void add_to_alternates_file(const char *reference
)
319 struct lock_file
*lock
= xcalloc(1, sizeof(struct lock_file
));
320 int fd
= hold_lock_file_for_append(lock
, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR
);
321 char *alt
= mkpath("%s/objects\n", reference
);
322 write_or_die(fd
, alt
, strlen(alt
));
323 if (commit_lock_file(lock
))
324 die("could not close alternates file");
326 link_alt_odb_entries(alt
, alt
+ strlen(alt
), '\n', NULL
, 0);
329 void foreach_alt_odb(alt_odb_fn fn
, void *cb
)
331 struct alternate_object_database
*ent
;
334 for (ent
= alt_odb_list
; ent
; ent
= ent
->next
)
339 void prepare_alt_odb(void)
346 alt
= getenv(ALTERNATE_DB_ENVIRONMENT
);
349 alt_odb_tail
= &alt_odb_list
;
350 link_alt_odb_entries(alt
, alt
+ strlen(alt
), PATH_SEP
, NULL
, 0);
352 read_info_alternates(get_object_directory(), 0);
355 static int has_loose_object_local(const unsigned char *sha1
)
357 char *name
= sha1_file_name(sha1
);
358 return !access(name
, F_OK
);
361 int has_loose_object_nonlocal(const unsigned char *sha1
)
363 struct alternate_object_database
*alt
;
365 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
366 fill_sha1_path(alt
->name
, sha1
);
367 if (!access(alt
->base
, F_OK
))
373 static int has_loose_object(const unsigned char *sha1
)
375 return has_loose_object_local(sha1
) ||
376 has_loose_object_nonlocal(sha1
);
379 static unsigned int pack_used_ctr
;
380 static unsigned int pack_mmap_calls
;
381 static unsigned int peak_pack_open_windows
;
382 static unsigned int pack_open_windows
;
383 static size_t peak_pack_mapped
;
384 static size_t pack_mapped
;
385 struct packed_git
*packed_git
;
387 void pack_report(void)
390 "pack_report: getpagesize() = %10" SZ_FMT
"\n"
391 "pack_report: core.packedGitWindowSize = %10" SZ_FMT
"\n"
392 "pack_report: core.packedGitLimit = %10" SZ_FMT
"\n",
393 sz_fmt(getpagesize()),
394 sz_fmt(packed_git_window_size
),
395 sz_fmt(packed_git_limit
));
397 "pack_report: pack_used_ctr = %10u\n"
398 "pack_report: pack_mmap_calls = %10u\n"
399 "pack_report: pack_open_windows = %10u / %10u\n"
400 "pack_report: pack_mapped = "
401 "%10" SZ_FMT
" / %10" SZ_FMT
"\n",
404 pack_open_windows
, peak_pack_open_windows
,
405 sz_fmt(pack_mapped
), sz_fmt(peak_pack_mapped
));
408 static int check_packed_git_idx(const char *path
, struct packed_git
*p
)
411 struct pack_idx_header
*hdr
;
413 uint32_t version
, nr
, i
, *index
;
414 int fd
= open(path
, O_RDONLY
);
419 if (fstat(fd
, &st
)) {
423 idx_size
= xsize_t(st
.st_size
);
424 if (idx_size
< 4 * 256 + 20 + 20) {
426 return error("index file %s is too small", path
);
428 idx_map
= xmmap(NULL
, idx_size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
432 if (hdr
->idx_signature
== htonl(PACK_IDX_SIGNATURE
)) {
433 version
= ntohl(hdr
->idx_version
);
434 if (version
< 2 || version
> 2) {
435 munmap(idx_map
, idx_size
);
436 return error("index file %s is version %"PRIu32
437 " and is not supported by this binary"
438 " (try upgrading GIT to a newer version)",
447 index
+= 2; /* skip index header */
448 for (i
= 0; i
< 256; i
++) {
449 uint32_t n
= ntohl(index
[i
]);
451 munmap(idx_map
, idx_size
);
452 return error("non-monotonic index %s", path
);
460 * - 256 index entries 4 bytes each
461 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
462 * - 20-byte SHA1 of the packfile
463 * - 20-byte SHA1 file checksum
465 if (idx_size
!= 4*256 + nr
* 24 + 20 + 20) {
466 munmap(idx_map
, idx_size
);
467 return error("wrong index v1 file size in %s", path
);
469 } else if (version
== 2) {
472 * - 8 bytes of header
473 * - 256 index entries 4 bytes each
474 * - 20-byte sha1 entry * nr
475 * - 4-byte crc entry * nr
476 * - 4-byte offset entry * nr
477 * - 20-byte SHA1 of the packfile
478 * - 20-byte SHA1 file checksum
479 * And after the 4-byte offset table might be a
480 * variable sized table containing 8-byte entries
481 * for offsets larger than 2^31.
483 unsigned long min_size
= 8 + 4*256 + nr
*(20 + 4 + 4) + 20 + 20;
484 unsigned long max_size
= min_size
;
486 max_size
+= (nr
- 1)*8;
487 if (idx_size
< min_size
|| idx_size
> max_size
) {
488 munmap(idx_map
, idx_size
);
489 return error("wrong index v2 file size in %s", path
);
491 if (idx_size
!= min_size
&&
493 * make sure we can deal with large pack offsets.
494 * 31-bit signed offset won't be enough, neither
495 * 32-bit unsigned one will be.
497 (sizeof(off_t
) <= 4)) {
498 munmap(idx_map
, idx_size
);
499 return error("pack too large for current definition of off_t in %s", path
);
503 p
->index_version
= version
;
504 p
->index_data
= idx_map
;
505 p
->index_size
= idx_size
;
510 int open_pack_index(struct packed_git
*p
)
518 idx_name
= xstrdup(p
->pack_name
);
519 strcpy(idx_name
+ strlen(idx_name
) - strlen(".pack"), ".idx");
520 ret
= check_packed_git_idx(idx_name
, p
);
525 static void scan_windows(struct packed_git
*p
,
526 struct packed_git
**lru_p
,
527 struct pack_window
**lru_w
,
528 struct pack_window
**lru_l
)
530 struct pack_window
*w
, *w_l
;
532 for (w_l
= NULL
, w
= p
->windows
; w
; w
= w
->next
) {
534 if (!*lru_w
|| w
->last_used
< (*lru_w
)->last_used
) {
544 static int unuse_one_window(struct packed_git
*current
, int keep_fd
)
546 struct packed_git
*p
, *lru_p
= NULL
;
547 struct pack_window
*lru_w
= NULL
, *lru_l
= NULL
;
550 scan_windows(current
, &lru_p
, &lru_w
, &lru_l
);
551 for (p
= packed_git
; p
; p
= p
->next
)
552 scan_windows(p
, &lru_p
, &lru_w
, &lru_l
);
554 munmap(lru_w
->base
, lru_w
->len
);
555 pack_mapped
-= lru_w
->len
;
557 lru_l
->next
= lru_w
->next
;
559 lru_p
->windows
= lru_w
->next
;
560 if (!lru_p
->windows
&& lru_p
->pack_fd
!= keep_fd
) {
561 close(lru_p
->pack_fd
);
572 void release_pack_memory(size_t need
, int fd
)
574 size_t cur
= pack_mapped
;
575 while (need
>= (cur
- pack_mapped
) && unuse_one_window(NULL
, fd
))
579 void *xmmap(void *start
, size_t length
,
580 int prot
, int flags
, int fd
, off_t offset
)
582 void *ret
= mmap(start
, length
, prot
, flags
, fd
, offset
);
583 if (ret
== MAP_FAILED
) {
586 release_pack_memory(length
, fd
);
587 ret
= mmap(start
, length
, prot
, flags
, fd
, offset
);
588 if (ret
== MAP_FAILED
)
589 die_errno("Out of memory? mmap failed");
594 void close_pack_windows(struct packed_git
*p
)
597 struct pack_window
*w
= p
->windows
;
600 die("pack '%s' still has open windows to it",
602 munmap(w
->base
, w
->len
);
603 pack_mapped
-= w
->len
;
605 p
->windows
= w
->next
;
610 void unuse_pack(struct pack_window
**w_cursor
)
612 struct pack_window
*w
= *w_cursor
;
619 void close_pack_index(struct packed_git
*p
)
622 munmap((void *)p
->index_data
, p
->index_size
);
623 p
->index_data
= NULL
;
628 * This is used by git-repack in case a newly created pack happens to
629 * contain the same set of objects as an existing one. In that case
630 * the resulting file might be different even if its name would be the
631 * same. It is best to close any reference to the old pack before it is
632 * replaced on disk. Of course no index pointers nor windows for given pack
633 * must subsist at this point. If ever objects from this pack are requested
634 * again, the new version of the pack will be reinitialized through
635 * reprepare_packed_git().
637 void free_pack_by_name(const char *pack_name
)
639 struct packed_git
*p
, **pp
= &packed_git
;
643 if (strcmp(pack_name
, p
->pack_name
) == 0) {
644 clear_delta_base_cache();
645 close_pack_windows(p
);
646 if (p
->pack_fd
!= -1)
649 free(p
->bad_object_sha1
);
659 * Do not call this directly as this leaks p->pack_fd on error return;
660 * call open_packed_git() instead.
662 static int open_packed_git_1(struct packed_git
*p
)
665 struct pack_header hdr
;
666 unsigned char sha1
[20];
667 unsigned char *idx_sha1
;
670 if (!p
->index_data
&& open_pack_index(p
))
671 return error("packfile %s index unavailable", p
->pack_name
);
673 p
->pack_fd
= open(p
->pack_name
, O_RDONLY
);
674 while (p
->pack_fd
< 0 && errno
== EMFILE
&& unuse_one_window(p
, -1))
675 p
->pack_fd
= open(p
->pack_name
, O_RDONLY
);
676 if (p
->pack_fd
< 0 || fstat(p
->pack_fd
, &st
))
679 /* If we created the struct before we had the pack we lack size. */
681 if (!S_ISREG(st
.st_mode
))
682 return error("packfile %s not a regular file", p
->pack_name
);
683 p
->pack_size
= st
.st_size
;
684 } else if (p
->pack_size
!= st
.st_size
)
685 return error("packfile %s size changed", p
->pack_name
);
687 /* We leave these file descriptors open with sliding mmap;
688 * there is no point keeping them open across exec(), though.
690 fd_flag
= fcntl(p
->pack_fd
, F_GETFD
, 0);
692 return error("cannot determine file descriptor flags");
693 fd_flag
|= FD_CLOEXEC
;
694 if (fcntl(p
->pack_fd
, F_SETFD
, fd_flag
) == -1)
695 return error("cannot set FD_CLOEXEC");
697 /* Verify we recognize this pack file format. */
698 if (read_in_full(p
->pack_fd
, &hdr
, sizeof(hdr
)) != sizeof(hdr
))
699 return error("file %s is far too short to be a packfile", p
->pack_name
);
700 if (hdr
.hdr_signature
!= htonl(PACK_SIGNATURE
))
701 return error("file %s is not a GIT packfile", p
->pack_name
);
702 if (!pack_version_ok(hdr
.hdr_version
))
703 return error("packfile %s is version %"PRIu32
" and not"
704 " supported (try upgrading GIT to a newer version)",
705 p
->pack_name
, ntohl(hdr
.hdr_version
));
707 /* Verify the pack matches its index. */
708 if (p
->num_objects
!= ntohl(hdr
.hdr_entries
))
709 return error("packfile %s claims to have %"PRIu32
" objects"
710 " while index indicates %"PRIu32
" objects",
711 p
->pack_name
, ntohl(hdr
.hdr_entries
),
713 if (lseek(p
->pack_fd
, p
->pack_size
- sizeof(sha1
), SEEK_SET
) == -1)
714 return error("end of packfile %s is unavailable", p
->pack_name
);
715 if (read_in_full(p
->pack_fd
, sha1
, sizeof(sha1
)) != sizeof(sha1
))
716 return error("packfile %s signature is unavailable", p
->pack_name
);
717 idx_sha1
= ((unsigned char *)p
->index_data
) + p
->index_size
- 40;
718 if (hashcmp(sha1
, idx_sha1
))
719 return error("packfile %s does not match index", p
->pack_name
);
723 static int open_packed_git(struct packed_git
*p
)
725 if (!open_packed_git_1(p
))
727 if (p
->pack_fd
!= -1) {
734 static int in_window(struct pack_window
*win
, off_t offset
)
736 /* We must promise at least 20 bytes (one hash) after the
737 * offset is available from this window, otherwise the offset
738 * is not actually in this window and a different window (which
739 * has that one hash excess) must be used. This is to support
740 * the object header and delta base parsing routines below.
742 off_t win_off
= win
->offset
;
743 return win_off
<= offset
744 && (offset
+ 20) <= (win_off
+ win
->len
);
747 unsigned char *use_pack(struct packed_git
*p
,
748 struct pack_window
**w_cursor
,
752 struct pack_window
*win
= *w_cursor
;
754 if (p
->pack_fd
== -1 && open_packed_git(p
))
755 die("packfile %s cannot be accessed", p
->pack_name
);
757 /* Since packfiles end in a hash of their content and it's
758 * pointless to ask for an offset into the middle of that
759 * hash, and the in_window function above wouldn't match
760 * don't allow an offset too close to the end of the file.
762 if (offset
> (p
->pack_size
- 20))
763 die("offset beyond end of packfile (truncated pack?)");
765 if (!win
|| !in_window(win
, offset
)) {
768 for (win
= p
->windows
; win
; win
= win
->next
) {
769 if (in_window(win
, offset
))
773 size_t window_align
= packed_git_window_size
/ 2;
775 win
= xcalloc(1, sizeof(*win
));
776 win
->offset
= (offset
/ window_align
) * window_align
;
777 len
= p
->pack_size
- win
->offset
;
778 if (len
> packed_git_window_size
)
779 len
= packed_git_window_size
;
780 win
->len
= (size_t)len
;
781 pack_mapped
+= win
->len
;
782 while (packed_git_limit
< pack_mapped
783 && unuse_one_window(p
, p
->pack_fd
))
785 win
->base
= xmmap(NULL
, win
->len
,
786 PROT_READ
, MAP_PRIVATE
,
787 p
->pack_fd
, win
->offset
);
788 if (win
->base
== MAP_FAILED
)
789 die("packfile %s cannot be mapped: %s",
794 if (pack_mapped
> peak_pack_mapped
)
795 peak_pack_mapped
= pack_mapped
;
796 if (pack_open_windows
> peak_pack_open_windows
)
797 peak_pack_open_windows
= pack_open_windows
;
798 win
->next
= p
->windows
;
802 if (win
!= *w_cursor
) {
803 win
->last_used
= pack_used_ctr
++;
807 offset
-= win
->offset
;
809 *left
= win
->len
- xsize_t(offset
);
810 return win
->base
+ offset
;
813 static struct packed_git
*alloc_packed_git(int extra
)
815 struct packed_git
*p
= xmalloc(sizeof(*p
) + extra
);
816 memset(p
, 0, sizeof(*p
));
821 static void try_to_free_pack_memory(size_t size
)
823 release_pack_memory(size
, -1);
826 struct packed_git
*add_packed_git(const char *path
, int path_len
, int local
)
828 static int have_set_try_to_free_routine
;
830 struct packed_git
*p
= alloc_packed_git(path_len
+ 2);
832 if (!have_set_try_to_free_routine
) {
833 have_set_try_to_free_routine
= 1;
834 set_try_to_free_routine(try_to_free_pack_memory
);
838 * Make sure a corresponding .pack file exists and that
839 * the index looks sane.
841 path_len
-= strlen(".idx");
846 memcpy(p
->pack_name
, path
, path_len
);
848 strcpy(p
->pack_name
+ path_len
, ".keep");
849 if (!access(p
->pack_name
, F_OK
))
852 strcpy(p
->pack_name
+ path_len
, ".pack");
853 if (stat(p
->pack_name
, &st
) || !S_ISREG(st
.st_mode
)) {
858 /* ok, it looks sane as far as we can check without
859 * actually mapping the pack file.
861 p
->pack_size
= st
.st_size
;
862 p
->pack_local
= local
;
863 p
->mtime
= st
.st_mtime
;
864 if (path_len
< 40 || get_sha1_hex(path
+ path_len
- 40, p
->sha1
))
869 struct packed_git
*parse_pack_index(unsigned char *sha1
, const char *idx_path
)
871 const char *path
= sha1_pack_name(sha1
);
872 struct packed_git
*p
= alloc_packed_git(strlen(path
) + 1);
874 strcpy(p
->pack_name
, path
);
875 hashcpy(p
->sha1
, sha1
);
876 if (check_packed_git_idx(idx_path
, p
)) {
884 void install_packed_git(struct packed_git
*pack
)
886 pack
->next
= packed_git
;
890 static void prepare_packed_git_one(char *objdir
, int local
)
892 /* Ensure that this buffer is large enough so that we can
893 append "/pack/" without clobbering the stack even if
894 strlen(objdir) were PATH_MAX. */
895 char path
[PATH_MAX
+ 1 + 4 + 1 + 1];
900 sprintf(path
, "%s/pack", objdir
);
903 while (!dir
&& errno
== EMFILE
&& unuse_one_window(packed_git
, -1))
907 error("unable to open object pack directory: %s: %s",
908 path
, strerror(errno
));
912 while ((de
= readdir(dir
)) != NULL
) {
913 int namelen
= strlen(de
->d_name
);
914 struct packed_git
*p
;
916 if (!has_extension(de
->d_name
, ".idx"))
919 if (len
+ namelen
+ 1 > sizeof(path
))
922 /* Don't reopen a pack we already have. */
923 strcpy(path
+ len
, de
->d_name
);
924 for (p
= packed_git
; p
; p
= p
->next
) {
925 if (!memcmp(path
, p
->pack_name
, len
+ namelen
- 4))
930 /* See if it really is a valid .idx file with corresponding
931 * .pack file that we can map.
933 p
= add_packed_git(path
, len
+ namelen
, local
);
936 install_packed_git(p
);
941 static int sort_pack(const void *a_
, const void *b_
)
943 struct packed_git
*a
= *((struct packed_git
**)a_
);
944 struct packed_git
*b
= *((struct packed_git
**)b_
);
948 * Local packs tend to contain objects specific to our
949 * variant of the project than remote ones. In addition,
950 * remote ones could be on a network mounted filesystem.
951 * Favor local ones for these reasons.
953 st
= a
->pack_local
- b
->pack_local
;
958 * Younger packs tend to contain more recent objects,
959 * and more recent objects tend to get accessed more
962 if (a
->mtime
< b
->mtime
)
964 else if (a
->mtime
== b
->mtime
)
969 static void rearrange_packed_git(void)
971 struct packed_git
**ary
, *p
;
974 for (n
= 0, p
= packed_git
; p
; p
= p
->next
)
979 /* prepare an array of packed_git for easier sorting */
980 ary
= xcalloc(n
, sizeof(struct packed_git
*));
981 for (n
= 0, p
= packed_git
; p
; p
= p
->next
)
984 qsort(ary
, n
, sizeof(struct packed_git
*), sort_pack
);
986 /* link them back again */
987 for (i
= 0; i
< n
- 1; i
++)
988 ary
[i
]->next
= ary
[i
+ 1];
989 ary
[n
- 1]->next
= NULL
;
995 static int prepare_packed_git_run_once
= 0;
996 void prepare_packed_git(void)
998 struct alternate_object_database
*alt
;
1000 if (prepare_packed_git_run_once
)
1002 prepare_packed_git_one(get_object_directory(), 1);
1004 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
1006 prepare_packed_git_one(alt
->base
, 0);
1007 alt
->name
[-1] = '/';
1009 rearrange_packed_git();
1010 prepare_packed_git_run_once
= 1;
1013 void reprepare_packed_git(void)
1016 prepare_packed_git_run_once
= 0;
1017 prepare_packed_git();
1020 static void mark_bad_packed_object(struct packed_git
*p
,
1021 const unsigned char *sha1
)
1024 for (i
= 0; i
< p
->num_bad_objects
; i
++)
1025 if (!hashcmp(sha1
, p
->bad_object_sha1
+ 20 * i
))
1027 p
->bad_object_sha1
= xrealloc(p
->bad_object_sha1
, 20 * (p
->num_bad_objects
+ 1));
1028 hashcpy(p
->bad_object_sha1
+ 20 * p
->num_bad_objects
, sha1
);
1029 p
->num_bad_objects
++;
1032 static int has_packed_and_bad(const unsigned char *sha1
)
1034 struct packed_git
*p
;
1037 for (p
= packed_git
; p
; p
= p
->next
)
1038 for (i
= 0; i
< p
->num_bad_objects
; i
++)
1039 if (!hashcmp(sha1
, p
->bad_object_sha1
+ 20 * i
))
1044 int check_sha1_signature(const unsigned char *sha1
, void *map
, unsigned long size
, const char *type
)
1046 unsigned char real_sha1
[20];
1047 hash_sha1_file(map
, size
, type
, real_sha1
);
1048 return hashcmp(sha1
, real_sha1
) ? -1 : 0;
1051 static int git_open_noatime(const char *name
)
1053 static int sha1_file_open_flag
= O_NOATIME
;
1054 int fd
= open(name
, O_RDONLY
| sha1_file_open_flag
);
1056 /* Might the failure be due to O_NOATIME? */
1057 if (fd
< 0 && errno
!= ENOENT
&& sha1_file_open_flag
) {
1058 fd
= open(name
, O_RDONLY
);
1060 sha1_file_open_flag
= 0;
1065 static int open_sha1_file(const unsigned char *sha1
)
1068 char *name
= sha1_file_name(sha1
);
1069 struct alternate_object_database
*alt
;
1071 fd
= git_open_noatime(name
);
1077 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
1079 fill_sha1_path(name
, sha1
);
1080 fd
= git_open_noatime(alt
->base
);
1087 static void *map_sha1_file(const unsigned char *sha1
, unsigned long *size
)
1092 fd
= open_sha1_file(sha1
);
1097 if (!fstat(fd
, &st
)) {
1098 *size
= xsize_t(st
.st_size
);
1099 map
= xmmap(NULL
, *size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
1106 static int legacy_loose_object(unsigned char *map
)
1111 * Is it a zlib-compressed buffer? If so, the first byte
1112 * must be 0x78 (15-bit window size, deflated), and the
1113 * first 16-bit word is evenly divisible by 31
1115 word
= (map
[0] << 8) + map
[1];
1116 if (map
[0] == 0x78 && !(word
% 31))
1122 unsigned long unpack_object_header_buffer(const unsigned char *buf
,
1123 unsigned long len
, enum object_type
*type
, unsigned long *sizep
)
1126 unsigned long size
, c
;
1127 unsigned long used
= 0;
1130 *type
= (c
>> 4) & 7;
1134 if (len
<= used
|| bitsizeof(long) <= shift
) {
1135 error("bad object header");
1139 size
+= (c
& 0x7f) << shift
;
1146 static int unpack_sha1_header(z_stream
*stream
, unsigned char *map
, unsigned long mapsize
, void *buffer
, unsigned long bufsiz
)
1148 unsigned long size
, used
;
1149 static const char valid_loose_object_type
[8] = {
1151 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1152 0, /* "delta" and others are invalid in a loose object */
1154 enum object_type type
;
1156 /* Get the data stream */
1157 memset(stream
, 0, sizeof(*stream
));
1158 stream
->next_in
= map
;
1159 stream
->avail_in
= mapsize
;
1160 stream
->next_out
= buffer
;
1161 stream
->avail_out
= bufsiz
;
1163 if (legacy_loose_object(map
)) {
1164 git_inflate_init(stream
);
1165 return git_inflate(stream
, 0);
1170 * There used to be a second loose object header format which
1171 * was meant to mimic the in-pack format, allowing for direct
1172 * copy of the object data. This format turned up not to be
1173 * really worth it and we don't write it any longer. But we
1174 * can still read it.
1176 used
= unpack_object_header_buffer(map
, mapsize
, &type
, &size
);
1177 if (!used
|| !valid_loose_object_type
[type
])
1182 /* Set up the stream for the rest.. */
1183 stream
->next_in
= map
;
1184 stream
->avail_in
= mapsize
;
1185 git_inflate_init(stream
);
1187 /* And generate the fake traditional header */
1188 stream
->total_out
= 1 + snprintf(buffer
, bufsiz
, "%s %lu",
1189 typename(type
), size
);
1193 static void *unpack_sha1_rest(z_stream
*stream
, void *buffer
, unsigned long size
, const unsigned char *sha1
)
1195 int bytes
= strlen(buffer
) + 1;
1196 unsigned char *buf
= xmallocz(size
);
1200 n
= stream
->total_out
- bytes
;
1203 memcpy(buf
, (char *) buffer
+ bytes
, n
);
1205 if (bytes
<= size
) {
1207 * The above condition must be (bytes <= size), not
1208 * (bytes < size). In other words, even though we
1209 * expect no more output and set avail_out to zer0,
1210 * the input zlib stream may have bytes that express
1211 * "this concludes the stream", and we *do* want to
1214 * Otherwise we would not be able to test that we
1215 * consumed all the input to reach the expected size;
1216 * we also want to check that zlib tells us that all
1217 * went well with status == Z_STREAM_END at the end.
1219 stream
->next_out
= buf
+ bytes
;
1220 stream
->avail_out
= size
- bytes
;
1221 while (status
== Z_OK
)
1222 status
= git_inflate(stream
, Z_FINISH
);
1224 if (status
== Z_STREAM_END
&& !stream
->avail_in
) {
1225 git_inflate_end(stream
);
1230 error("corrupt loose object '%s'", sha1_to_hex(sha1
));
1231 else if (stream
->avail_in
)
1232 error("garbage at end of loose object '%s'",
1239 * We used to just use "sscanf()", but that's actually way
1240 * too permissive for what we want to check. So do an anal
1241 * object header parse by hand.
1243 static int parse_sha1_header(const char *hdr
, unsigned long *sizep
)
1250 * The type can be at most ten bytes (including the
1251 * terminating '\0' that we add), and is followed by
1260 if (i
>= sizeof(type
))
1266 * The length must follow immediately, and be in canonical
1267 * decimal format (ie "010" is not valid).
1269 size
= *hdr
++ - '0';
1274 unsigned long c
= *hdr
- '0';
1278 size
= size
* 10 + c
;
1284 * The length must be followed by a zero byte
1286 return *hdr
? -1 : type_from_string(type
);
1289 static void *unpack_sha1_file(void *map
, unsigned long mapsize
, enum object_type
*type
, unsigned long *size
, const unsigned char *sha1
)
1295 ret
= unpack_sha1_header(&stream
, map
, mapsize
, hdr
, sizeof(hdr
));
1296 if (ret
< Z_OK
|| (*type
= parse_sha1_header(hdr
, size
)) < 0)
1299 return unpack_sha1_rest(&stream
, hdr
, *size
, sha1
);
1302 unsigned long get_size_from_delta(struct packed_git
*p
,
1303 struct pack_window
**w_curs
,
1306 const unsigned char *data
;
1307 unsigned char delta_head
[20], *in
;
1311 memset(&stream
, 0, sizeof(stream
));
1312 stream
.next_out
= delta_head
;
1313 stream
.avail_out
= sizeof(delta_head
);
1315 git_inflate_init(&stream
);
1317 in
= use_pack(p
, w_curs
, curpos
, &stream
.avail_in
);
1318 stream
.next_in
= in
;
1319 st
= git_inflate(&stream
, Z_FINISH
);
1320 curpos
+= stream
.next_in
- in
;
1321 } while ((st
== Z_OK
|| st
== Z_BUF_ERROR
) &&
1322 stream
.total_out
< sizeof(delta_head
));
1323 git_inflate_end(&stream
);
1324 if ((st
!= Z_STREAM_END
) && stream
.total_out
!= sizeof(delta_head
)) {
1325 error("delta data unpack-initial failed");
1329 /* Examine the initial part of the delta to figure out
1334 /* ignore base size */
1335 get_delta_hdr_size(&data
, delta_head
+sizeof(delta_head
));
1337 /* Read the result size */
1338 return get_delta_hdr_size(&data
, delta_head
+sizeof(delta_head
));
1341 static off_t
get_delta_base(struct packed_git
*p
,
1342 struct pack_window
**w_curs
,
1344 enum object_type type
,
1345 off_t delta_obj_offset
)
1347 unsigned char *base_info
= use_pack(p
, w_curs
, *curpos
, NULL
);
1350 /* use_pack() assured us we have [base_info, base_info + 20)
1351 * as a range that we can look at without walking off the
1352 * end of the mapped window. Its actually the hash size
1353 * that is assured. An OFS_DELTA longer than the hash size
1354 * is stupid, as then a REF_DELTA would be smaller to store.
1356 if (type
== OBJ_OFS_DELTA
) {
1358 unsigned char c
= base_info
[used
++];
1359 base_offset
= c
& 127;
1362 if (!base_offset
|| MSB(base_offset
, 7))
1363 return 0; /* overflow */
1364 c
= base_info
[used
++];
1365 base_offset
= (base_offset
<< 7) + (c
& 127);
1367 base_offset
= delta_obj_offset
- base_offset
;
1368 if (base_offset
<= 0 || base_offset
>= delta_obj_offset
)
1369 return 0; /* out of bound */
1371 } else if (type
== OBJ_REF_DELTA
) {
1372 /* The base entry _must_ be in the same pack */
1373 base_offset
= find_pack_entry_one(base_info
, p
);
1376 die("I am totally screwed");
1380 /* forward declaration for a mutually recursive function */
1381 static int packed_object_info(struct packed_git
*p
, off_t offset
,
1382 unsigned long *sizep
);
1384 static int packed_delta_info(struct packed_git
*p
,
1385 struct pack_window
**w_curs
,
1387 enum object_type type
,
1389 unsigned long *sizep
)
1393 base_offset
= get_delta_base(p
, w_curs
, &curpos
, type
, obj_offset
);
1396 type
= packed_object_info(p
, base_offset
, NULL
);
1397 if (type
<= OBJ_NONE
) {
1398 struct revindex_entry
*revidx
;
1399 const unsigned char *base_sha1
;
1400 revidx
= find_pack_revindex(p
, base_offset
);
1403 base_sha1
= nth_packed_object_sha1(p
, revidx
->nr
);
1404 mark_bad_packed_object(p
, base_sha1
);
1405 type
= sha1_object_info(base_sha1
, NULL
);
1406 if (type
<= OBJ_NONE
)
1410 /* We choose to only get the type of the base object and
1411 * ignore potentially corrupt pack file that expects the delta
1412 * based on a base with a wrong size. This saves tons of
1416 *sizep
= get_size_from_delta(p
, w_curs
, curpos
);
1424 static int unpack_object_header(struct packed_git
*p
,
1425 struct pack_window
**w_curs
,
1427 unsigned long *sizep
)
1429 unsigned char *base
;
1432 enum object_type type
;
1434 /* use_pack() assures us we have [base, base + 20) available
1435 * as a range that we can look at at. (Its actually the hash
1436 * size that is assured.) With our object header encoding
1437 * the maximum deflated object size is 2^137, which is just
1438 * insane, so we know won't exceed what we have been given.
1440 base
= use_pack(p
, w_curs
, *curpos
, &left
);
1441 used
= unpack_object_header_buffer(base
, left
, &type
, sizep
);
1450 const char *packed_object_info_detail(struct packed_git
*p
,
1452 unsigned long *size
,
1453 unsigned long *store_size
,
1454 unsigned int *delta_chain_length
,
1455 unsigned char *base_sha1
)
1457 struct pack_window
*w_curs
= NULL
;
1459 unsigned long dummy
;
1460 unsigned char *next_sha1
;
1461 enum object_type type
;
1462 struct revindex_entry
*revidx
;
1464 *delta_chain_length
= 0;
1465 curpos
= obj_offset
;
1466 type
= unpack_object_header(p
, &w_curs
, &curpos
, size
);
1468 revidx
= find_pack_revindex(p
, obj_offset
);
1469 *store_size
= revidx
[1].offset
- obj_offset
;
1474 die("pack %s contains unknown object type %d",
1475 p
->pack_name
, type
);
1480 unuse_pack(&w_curs
);
1481 return typename(type
);
1483 obj_offset
= get_delta_base(p
, &w_curs
, &curpos
, type
, obj_offset
);
1485 die("pack %s contains bad delta base reference of type %s",
1486 p
->pack_name
, typename(type
));
1487 if (*delta_chain_length
== 0) {
1488 revidx
= find_pack_revindex(p
, obj_offset
);
1489 hashcpy(base_sha1
, nth_packed_object_sha1(p
, revidx
->nr
));
1493 next_sha1
= use_pack(p
, &w_curs
, curpos
, NULL
);
1494 if (*delta_chain_length
== 0)
1495 hashcpy(base_sha1
, next_sha1
);
1496 obj_offset
= find_pack_entry_one(next_sha1
, p
);
1499 (*delta_chain_length
)++;
1500 curpos
= obj_offset
;
1501 type
= unpack_object_header(p
, &w_curs
, &curpos
, &dummy
);
1505 static int packed_object_info(struct packed_git
*p
, off_t obj_offset
,
1506 unsigned long *sizep
)
1508 struct pack_window
*w_curs
= NULL
;
1510 off_t curpos
= obj_offset
;
1511 enum object_type type
;
1513 type
= unpack_object_header(p
, &w_curs
, &curpos
, &size
);
1518 type
= packed_delta_info(p
, &w_curs
, curpos
,
1519 type
, obj_offset
, sizep
);
1529 error("unknown object type %i at offset %"PRIuMAX
" in %s",
1530 type
, (uintmax_t)obj_offset
, p
->pack_name
);
1533 unuse_pack(&w_curs
);
1537 static void *unpack_compressed_entry(struct packed_git
*p
,
1538 struct pack_window
**w_curs
,
1544 unsigned char *buffer
, *in
;
1546 buffer
= xmallocz(size
);
1547 memset(&stream
, 0, sizeof(stream
));
1548 stream
.next_out
= buffer
;
1549 stream
.avail_out
= size
+ 1;
1551 git_inflate_init(&stream
);
1553 in
= use_pack(p
, w_curs
, curpos
, &stream
.avail_in
);
1554 stream
.next_in
= in
;
1555 st
= git_inflate(&stream
, Z_FINISH
);
1556 if (!stream
.avail_out
)
1557 break; /* the payload is larger than it should be */
1558 curpos
+= stream
.next_in
- in
;
1559 } while (st
== Z_OK
|| st
== Z_BUF_ERROR
);
1560 git_inflate_end(&stream
);
1561 if ((st
!= Z_STREAM_END
) || stream
.total_out
!= size
) {
1569 #define MAX_DELTA_CACHE (256)
1571 static size_t delta_base_cached
;
1573 static struct delta_base_cache_lru_list
{
1574 struct delta_base_cache_lru_list
*prev
;
1575 struct delta_base_cache_lru_list
*next
;
1576 } delta_base_cache_lru
= { &delta_base_cache_lru
, &delta_base_cache_lru
};
1578 static struct delta_base_cache_entry
{
1579 struct delta_base_cache_lru_list lru
;
1581 struct packed_git
*p
;
1584 enum object_type type
;
1585 } delta_base_cache
[MAX_DELTA_CACHE
];
1587 static unsigned long pack_entry_hash(struct packed_git
*p
, off_t base_offset
)
1591 hash
= (unsigned long)p
+ (unsigned long)base_offset
;
1592 hash
+= (hash
>> 8) + (hash
>> 16);
1593 return hash
% MAX_DELTA_CACHE
;
1596 static void *cache_or_unpack_entry(struct packed_git
*p
, off_t base_offset
,
1597 unsigned long *base_size
, enum object_type
*type
, int keep_cache
)
1600 unsigned long hash
= pack_entry_hash(p
, base_offset
);
1601 struct delta_base_cache_entry
*ent
= delta_base_cache
+ hash
;
1604 if (!ret
|| ent
->p
!= p
|| ent
->base_offset
!= base_offset
)
1605 return unpack_entry(p
, base_offset
, type
, base_size
);
1609 ent
->lru
.next
->prev
= ent
->lru
.prev
;
1610 ent
->lru
.prev
->next
= ent
->lru
.next
;
1611 delta_base_cached
-= ent
->size
;
1613 ret
= xmemdupz(ent
->data
, ent
->size
);
1616 *base_size
= ent
->size
;
1620 static inline void release_delta_base_cache(struct delta_base_cache_entry
*ent
)
1625 ent
->lru
.next
->prev
= ent
->lru
.prev
;
1626 ent
->lru
.prev
->next
= ent
->lru
.next
;
1627 delta_base_cached
-= ent
->size
;
1631 void clear_delta_base_cache(void)
1634 for (p
= 0; p
< MAX_DELTA_CACHE
; p
++)
1635 release_delta_base_cache(&delta_base_cache
[p
]);
1638 static void add_delta_base_cache(struct packed_git
*p
, off_t base_offset
,
1639 void *base
, unsigned long base_size
, enum object_type type
)
1641 unsigned long hash
= pack_entry_hash(p
, base_offset
);
1642 struct delta_base_cache_entry
*ent
= delta_base_cache
+ hash
;
1643 struct delta_base_cache_lru_list
*lru
;
1645 release_delta_base_cache(ent
);
1646 delta_base_cached
+= base_size
;
1648 for (lru
= delta_base_cache_lru
.next
;
1649 delta_base_cached
> delta_base_cache_limit
1650 && lru
!= &delta_base_cache_lru
;
1652 struct delta_base_cache_entry
*f
= (void *)lru
;
1653 if (f
->type
== OBJ_BLOB
)
1654 release_delta_base_cache(f
);
1656 for (lru
= delta_base_cache_lru
.next
;
1657 delta_base_cached
> delta_base_cache_limit
1658 && lru
!= &delta_base_cache_lru
;
1660 struct delta_base_cache_entry
*f
= (void *)lru
;
1661 release_delta_base_cache(f
);
1665 ent
->base_offset
= base_offset
;
1668 ent
->size
= base_size
;
1669 ent
->lru
.next
= &delta_base_cache_lru
;
1670 ent
->lru
.prev
= delta_base_cache_lru
.prev
;
1671 delta_base_cache_lru
.prev
->next
= &ent
->lru
;
1672 delta_base_cache_lru
.prev
= &ent
->lru
;
1675 static void *read_object(const unsigned char *sha1
, enum object_type
*type
,
1676 unsigned long *size
);
1678 static void *unpack_delta_entry(struct packed_git
*p
,
1679 struct pack_window
**w_curs
,
1681 unsigned long delta_size
,
1683 enum object_type
*type
,
1684 unsigned long *sizep
)
1686 void *delta_data
, *result
, *base
;
1687 unsigned long base_size
;
1690 base_offset
= get_delta_base(p
, w_curs
, &curpos
, *type
, obj_offset
);
1692 error("failed to validate delta base reference "
1693 "at offset %"PRIuMAX
" from %s",
1694 (uintmax_t)curpos
, p
->pack_name
);
1698 base
= cache_or_unpack_entry(p
, base_offset
, &base_size
, type
, 0);
1701 * We're probably in deep shit, but let's try to fetch
1702 * the required base anyway from another pack or loose.
1703 * This is costly but should happen only in the presence
1704 * of a corrupted pack, and is better than failing outright.
1706 struct revindex_entry
*revidx
;
1707 const unsigned char *base_sha1
;
1708 revidx
= find_pack_revindex(p
, base_offset
);
1711 base_sha1
= nth_packed_object_sha1(p
, revidx
->nr
);
1712 error("failed to read delta base object %s"
1713 " at offset %"PRIuMAX
" from %s",
1714 sha1_to_hex(base_sha1
), (uintmax_t)base_offset
,
1716 mark_bad_packed_object(p
, base_sha1
);
1717 base
= read_object(base_sha1
, type
, &base_size
);
1722 delta_data
= unpack_compressed_entry(p
, w_curs
, curpos
, delta_size
);
1724 error("failed to unpack compressed delta "
1725 "at offset %"PRIuMAX
" from %s",
1726 (uintmax_t)curpos
, p
->pack_name
);
1730 result
= patch_delta(base
, base_size
,
1731 delta_data
, delta_size
,
1734 die("failed to apply delta");
1736 add_delta_base_cache(p
, base_offset
, base
, base_size
, *type
);
1740 int do_check_packed_object_crc
;
1742 void *unpack_entry(struct packed_git
*p
, off_t obj_offset
,
1743 enum object_type
*type
, unsigned long *sizep
)
1745 struct pack_window
*w_curs
= NULL
;
1746 off_t curpos
= obj_offset
;
1749 if (do_check_packed_object_crc
&& p
->index_version
> 1) {
1750 struct revindex_entry
*revidx
= find_pack_revindex(p
, obj_offset
);
1751 unsigned long len
= revidx
[1].offset
- obj_offset
;
1752 if (check_pack_crc(p
, &w_curs
, obj_offset
, len
, revidx
->nr
)) {
1753 const unsigned char *sha1
=
1754 nth_packed_object_sha1(p
, revidx
->nr
);
1755 error("bad packed object CRC for %s",
1757 mark_bad_packed_object(p
, sha1
);
1758 unuse_pack(&w_curs
);
1763 *type
= unpack_object_header(p
, &w_curs
, &curpos
, sizep
);
1767 data
= unpack_delta_entry(p
, &w_curs
, curpos
, *sizep
,
1768 obj_offset
, type
, sizep
);
1774 data
= unpack_compressed_entry(p
, &w_curs
, curpos
, *sizep
);
1778 error("unknown object type %i at offset %"PRIuMAX
" in %s",
1779 *type
, (uintmax_t)obj_offset
, p
->pack_name
);
1781 unuse_pack(&w_curs
);
1785 const unsigned char *nth_packed_object_sha1(struct packed_git
*p
,
1788 const unsigned char *index
= p
->index_data
;
1790 if (open_pack_index(p
))
1792 index
= p
->index_data
;
1794 if (n
>= p
->num_objects
)
1797 if (p
->index_version
== 1) {
1798 return index
+ 24 * n
+ 4;
1801 return index
+ 20 * n
;
1805 off_t
nth_packed_object_offset(const struct packed_git
*p
, uint32_t n
)
1807 const unsigned char *index
= p
->index_data
;
1809 if (p
->index_version
== 1) {
1810 return ntohl(*((uint32_t *)(index
+ 24 * n
)));
1813 index
+= 8 + p
->num_objects
* (20 + 4);
1814 off
= ntohl(*((uint32_t *)(index
+ 4 * n
)));
1815 if (!(off
& 0x80000000))
1817 index
+= p
->num_objects
* 4 + (off
& 0x7fffffff) * 8;
1818 return (((uint64_t)ntohl(*((uint32_t *)(index
+ 0)))) << 32) |
1819 ntohl(*((uint32_t *)(index
+ 4)));
1823 off_t
find_pack_entry_one(const unsigned char *sha1
,
1824 struct packed_git
*p
)
1826 const uint32_t *level1_ofs
= p
->index_data
;
1827 const unsigned char *index
= p
->index_data
;
1828 unsigned hi
, lo
, stride
;
1829 static int use_lookup
= -1;
1830 static int debug_lookup
= -1;
1832 if (debug_lookup
< 0)
1833 debug_lookup
= !!getenv("GIT_DEBUG_LOOKUP");
1836 if (open_pack_index(p
))
1838 level1_ofs
= p
->index_data
;
1839 index
= p
->index_data
;
1841 if (p
->index_version
> 1) {
1846 hi
= ntohl(level1_ofs
[*sha1
]);
1847 lo
= ((*sha1
== 0x0) ? 0 : ntohl(level1_ofs
[*sha1
- 1]));
1848 if (p
->index_version
> 1) {
1856 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32
"\n",
1857 sha1
[0], sha1
[1], sha1
[2], lo
, hi
, p
->num_objects
);
1860 use_lookup
= !!getenv("GIT_USE_LOOKUP");
1862 int pos
= sha1_entry_pos(index
, stride
, 0,
1863 lo
, hi
, p
->num_objects
, sha1
);
1866 return nth_packed_object_offset(p
, pos
);
1870 unsigned mi
= (lo
+ hi
) / 2;
1871 int cmp
= hashcmp(index
+ mi
* stride
, sha1
);
1874 printf("lo %u hi %u rg %u mi %u\n",
1875 lo
, hi
, hi
- lo
, mi
);
1877 return nth_packed_object_offset(p
, mi
);
1886 static int find_pack_entry(const unsigned char *sha1
, struct pack_entry
*e
)
1888 static struct packed_git
*last_found
= (void *)1;
1889 struct packed_git
*p
;
1892 prepare_packed_git();
1895 p
= (last_found
== (void *)1) ? packed_git
: last_found
;
1898 if (p
->num_bad_objects
) {
1900 for (i
= 0; i
< p
->num_bad_objects
; i
++)
1901 if (!hashcmp(sha1
, p
->bad_object_sha1
+ 20 * i
))
1905 offset
= find_pack_entry_one(sha1
, p
);
1908 * We are about to tell the caller where they can
1909 * locate the requested object. We better make
1910 * sure the packfile is still here and can be
1911 * accessed before supplying that answer, as
1912 * it may have been deleted since the index
1915 if (p
->pack_fd
== -1 && open_packed_git(p
)) {
1916 error("packfile %s cannot be accessed", p
->pack_name
);
1921 hashcpy(e
->sha1
, sha1
);
1927 if (p
== last_found
)
1931 if (p
== last_found
)
1937 struct packed_git
*find_sha1_pack(const unsigned char *sha1
,
1938 struct packed_git
*packs
)
1940 struct packed_git
*p
;
1942 for (p
= packs
; p
; p
= p
->next
) {
1943 if (find_pack_entry_one(sha1
, p
))
1950 static int sha1_loose_object_info(const unsigned char *sha1
, unsigned long *sizep
)
1953 unsigned long mapsize
, size
;
1958 map
= map_sha1_file(sha1
, &mapsize
);
1960 return error("unable to find %s", sha1_to_hex(sha1
));
1961 if (unpack_sha1_header(&stream
, map
, mapsize
, hdr
, sizeof(hdr
)) < 0)
1962 status
= error("unable to unpack %s header",
1964 else if ((status
= parse_sha1_header(hdr
, &size
)) < 0)
1965 status
= error("unable to parse %s header", sha1_to_hex(sha1
));
1968 git_inflate_end(&stream
);
1969 munmap(map
, mapsize
);
1973 int sha1_object_info(const unsigned char *sha1
, unsigned long *sizep
)
1975 struct pack_entry e
;
1978 if (!find_pack_entry(sha1
, &e
)) {
1979 /* Most likely it's a loose object. */
1980 status
= sha1_loose_object_info(sha1
, sizep
);
1984 /* Not a loose object; someone else may have just packed it. */
1985 reprepare_packed_git();
1986 if (!find_pack_entry(sha1
, &e
))
1990 status
= packed_object_info(e
.p
, e
.offset
, sizep
);
1992 mark_bad_packed_object(e
.p
, sha1
);
1993 status
= sha1_object_info(sha1
, sizep
);
1999 static void *read_packed_sha1(const unsigned char *sha1
,
2000 enum object_type
*type
, unsigned long *size
)
2002 struct pack_entry e
;
2005 if (!find_pack_entry(sha1
, &e
))
2007 data
= cache_or_unpack_entry(e
.p
, e
.offset
, size
, type
, 1);
2010 * We're probably in deep shit, but let's try to fetch
2011 * the required object anyway from another pack or loose.
2012 * This should happen only in the presence of a corrupted
2013 * pack, and is better than failing outright.
2015 error("failed to read object %s at offset %"PRIuMAX
" from %s",
2016 sha1_to_hex(sha1
), (uintmax_t)e
.offset
, e
.p
->pack_name
);
2017 mark_bad_packed_object(e
.p
, sha1
);
2018 data
= read_object(sha1
, type
, size
);
2024 * This is meant to hold a *small* number of objects that you would
2025 * want read_sha1_file() to be able to return, but yet you do not want
2026 * to write them into the object store (e.g. a browse-only
2029 static struct cached_object
{
2030 unsigned char sha1
[20];
2031 enum object_type type
;
2035 static int cached_object_nr
, cached_object_alloc
;
2037 static struct cached_object empty_tree
= {
2038 EMPTY_TREE_SHA1_BIN
,
2044 static struct cached_object
*find_cached_object(const unsigned char *sha1
)
2047 struct cached_object
*co
= cached_objects
;
2049 for (i
= 0; i
< cached_object_nr
; i
++, co
++) {
2050 if (!hashcmp(co
->sha1
, sha1
))
2053 if (!hashcmp(sha1
, empty_tree
.sha1
))
2058 int pretend_sha1_file(void *buf
, unsigned long len
, enum object_type type
,
2059 unsigned char *sha1
)
2061 struct cached_object
*co
;
2063 hash_sha1_file(buf
, len
, typename(type
), sha1
);
2064 if (has_sha1_file(sha1
) || find_cached_object(sha1
))
2066 if (cached_object_alloc
<= cached_object_nr
) {
2067 cached_object_alloc
= alloc_nr(cached_object_alloc
);
2068 cached_objects
= xrealloc(cached_objects
,
2069 sizeof(*cached_objects
) *
2070 cached_object_alloc
);
2072 co
= &cached_objects
[cached_object_nr
++];
2075 co
->buf
= xmalloc(len
);
2076 memcpy(co
->buf
, buf
, len
);
2077 hashcpy(co
->sha1
, sha1
);
2081 static void *read_object(const unsigned char *sha1
, enum object_type
*type
,
2082 unsigned long *size
)
2084 unsigned long mapsize
;
2086 struct cached_object
*co
;
2088 co
= find_cached_object(sha1
);
2092 return xmemdupz(co
->buf
, co
->size
);
2095 buf
= read_packed_sha1(sha1
, type
, size
);
2098 map
= map_sha1_file(sha1
, &mapsize
);
2100 buf
= unpack_sha1_file(map
, mapsize
, type
, size
, sha1
);
2101 munmap(map
, mapsize
);
2104 reprepare_packed_git();
2105 return read_packed_sha1(sha1
, type
, size
);
2108 void *read_sha1_file_repl(const unsigned char *sha1
,
2109 enum object_type
*type
,
2110 unsigned long *size
,
2111 const unsigned char **replacement
)
2113 const unsigned char *repl
= lookup_replace_object(sha1
);
2114 void *data
= read_object(repl
, type
, size
);
2117 /* die if we replaced an object with one that does not exist */
2118 if (!data
&& repl
!= sha1
)
2119 die("replacement %s not found for %s",
2120 sha1_to_hex(repl
), sha1_to_hex(sha1
));
2122 /* legacy behavior is to die on corrupted objects */
2124 if (has_loose_object(repl
)) {
2125 path
= sha1_file_name(sha1
);
2126 die("loose object %s (stored in %s) is corrupted", sha1_to_hex(repl
), path
);
2128 if (has_packed_and_bad(repl
)) {
2129 path
= sha1_pack_name(sha1
);
2130 die("packed object %s (stored in %s) is corrupted", sha1_to_hex(repl
), path
);
2135 *replacement
= repl
;
2140 void *read_object_with_reference(const unsigned char *sha1
,
2141 const char *required_type_name
,
2142 unsigned long *size
,
2143 unsigned char *actual_sha1_return
)
2145 enum object_type type
, required_type
;
2147 unsigned long isize
;
2148 unsigned char actual_sha1
[20];
2150 required_type
= type_from_string(required_type_name
);
2151 hashcpy(actual_sha1
, sha1
);
2153 int ref_length
= -1;
2154 const char *ref_type
= NULL
;
2156 buffer
= read_sha1_file(actual_sha1
, &type
, &isize
);
2159 if (type
== required_type
) {
2161 if (actual_sha1_return
)
2162 hashcpy(actual_sha1_return
, actual_sha1
);
2165 /* Handle references */
2166 else if (type
== OBJ_COMMIT
)
2168 else if (type
== OBJ_TAG
)
2169 ref_type
= "object ";
2174 ref_length
= strlen(ref_type
);
2176 if (ref_length
+ 40 > isize
||
2177 memcmp(buffer
, ref_type
, ref_length
) ||
2178 get_sha1_hex((char *) buffer
+ ref_length
, actual_sha1
)) {
2183 /* Now we have the ID of the referred-to object in
2184 * actual_sha1. Check again. */
2188 static void write_sha1_file_prepare(const void *buf
, unsigned long len
,
2189 const char *type
, unsigned char *sha1
,
2190 char *hdr
, int *hdrlen
)
2194 /* Generate the header */
2195 *hdrlen
= sprintf(hdr
, "%s %lu", type
, len
)+1;
2199 git_SHA1_Update(&c
, hdr
, *hdrlen
);
2200 git_SHA1_Update(&c
, buf
, len
);
2201 git_SHA1_Final(sha1
, &c
);
2205 * Move the just written object into its final resting place.
2206 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2207 * "moving" is only a part of what it does, when no patch between
2208 * master to pu changes the call sites of this function.
2210 int move_temp_to_file(const char *tmpfile
, const char *filename
)
2214 if (object_creation_mode
== OBJECT_CREATION_USES_RENAMES
)
2216 else if (link(tmpfile
, filename
))
2220 * Coda hack - coda doesn't like cross-directory links,
2221 * so we fall back to a rename, which will mean that it
2222 * won't be able to check collisions, but that's not a
2225 * The same holds for FAT formatted media.
2227 * When this succeeds, we just return. We have nothing
2230 if (ret
&& ret
!= EEXIST
) {
2232 if (!rename(tmpfile
, filename
))
2236 unlink_or_warn(tmpfile
);
2238 if (ret
!= EEXIST
) {
2239 return error("unable to write sha1 filename %s: %s\n", filename
, strerror(ret
));
2241 /* FIXME!!! Collision check here ? */
2245 if (adjust_shared_perm(filename
))
2246 return error("unable to set permission to '%s'", filename
);
2250 static int write_buffer(int fd
, const void *buf
, size_t len
)
2252 if (write_in_full(fd
, buf
, len
) < 0)
2253 return error("file write error (%s)", strerror(errno
));
2257 int hash_sha1_file(const void *buf
, unsigned long len
, const char *type
,
2258 unsigned char *sha1
)
2262 write_sha1_file_prepare(buf
, len
, type
, sha1
, hdr
, &hdrlen
);
2266 /* Finalize a file on disk, and close it. */
2267 static void close_sha1_file(int fd
)
2269 if (fsync_object_files
)
2270 fsync_or_die(fd
, "sha1 file");
2272 die_errno("error when closing sha1 file");
2275 /* Size of directory component, including the ending '/' */
2276 static inline int directory_size(const char *filename
)
2278 const char *s
= strrchr(filename
, '/');
2281 return s
- filename
+ 1;
2285 * This creates a temporary file in the same directory as the final
2288 * We want to avoid cross-directory filename renames, because those
2289 * can have problems on various filesystems (FAT, NFS, Coda).
2291 static int create_tmpfile(char *buffer
, size_t bufsiz
, const char *filename
)
2293 int fd
, dirlen
= directory_size(filename
);
2295 if (dirlen
+ 20 > bufsiz
) {
2296 errno
= ENAMETOOLONG
;
2299 memcpy(buffer
, filename
, dirlen
);
2300 strcpy(buffer
+ dirlen
, "tmp_obj_XXXXXX");
2301 fd
= git_mkstemp_mode(buffer
, 0444);
2302 if (fd
< 0 && dirlen
&& errno
== ENOENT
) {
2303 /* Make sure the directory exists */
2304 memcpy(buffer
, filename
, dirlen
);
2305 buffer
[dirlen
-1] = 0;
2306 if (mkdir(buffer
, 0777) || adjust_shared_perm(buffer
))
2310 strcpy(buffer
+ dirlen
- 1, "/tmp_obj_XXXXXX");
2311 fd
= git_mkstemp_mode(buffer
, 0444);
2316 static int write_loose_object(const unsigned char *sha1
, char *hdr
, int hdrlen
,
2317 const void *buf
, unsigned long len
, time_t mtime
)
2320 unsigned char compressed
[4096];
2323 unsigned char parano_sha1
[20];
2325 static char tmpfile
[PATH_MAX
];
2327 filename
= sha1_file_name(sha1
);
2328 fd
= create_tmpfile(tmpfile
, sizeof(tmpfile
), filename
);
2329 while (fd
< 0 && errno
== EMFILE
&& unuse_one_window(packed_git
, -1))
2330 fd
= create_tmpfile(tmpfile
, sizeof(tmpfile
), filename
);
2332 if (errno
== EACCES
)
2333 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2335 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile
, strerror(errno
));
2339 memset(&stream
, 0, sizeof(stream
));
2340 deflateInit(&stream
, zlib_compression_level
);
2341 stream
.next_out
= compressed
;
2342 stream
.avail_out
= sizeof(compressed
);
2345 /* First header.. */
2346 stream
.next_in
= (unsigned char *)hdr
;
2347 stream
.avail_in
= hdrlen
;
2348 while (deflate(&stream
, 0) == Z_OK
)
2350 git_SHA1_Update(&c
, hdr
, hdrlen
);
2352 /* Then the data itself.. */
2353 stream
.next_in
= (void *)buf
;
2354 stream
.avail_in
= len
;
2356 unsigned char *in0
= stream
.next_in
;
2357 ret
= deflate(&stream
, Z_FINISH
);
2358 git_SHA1_Update(&c
, in0
, stream
.next_in
- in0
);
2359 if (write_buffer(fd
, compressed
, stream
.next_out
- compressed
) < 0)
2360 die("unable to write sha1 file");
2361 stream
.next_out
= compressed
;
2362 stream
.avail_out
= sizeof(compressed
);
2363 } while (ret
== Z_OK
);
2365 if (ret
!= Z_STREAM_END
)
2366 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1
), ret
);
2367 ret
= deflateEnd(&stream
);
2369 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1
), ret
);
2370 git_SHA1_Final(parano_sha1
, &c
);
2371 if (hashcmp(sha1
, parano_sha1
) != 0)
2372 die("confused by unstable object source data for %s", sha1_to_hex(sha1
));
2374 close_sha1_file(fd
);
2379 utb
.modtime
= mtime
;
2380 if (utime(tmpfile
, &utb
) < 0)
2381 warning("failed utime() on %s: %s",
2382 tmpfile
, strerror(errno
));
2385 return move_temp_to_file(tmpfile
, filename
);
2388 int write_sha1_file(const void *buf
, unsigned long len
, const char *type
, unsigned char *returnsha1
)
2390 unsigned char sha1
[20];
2394 /* Normally if we have it in the pack then we do not bother writing
2395 * it out into .git/objects/??/?{38} file.
2397 write_sha1_file_prepare(buf
, len
, type
, sha1
, hdr
, &hdrlen
);
2399 hashcpy(returnsha1
, sha1
);
2400 if (has_sha1_file(sha1
))
2402 return write_loose_object(sha1
, hdr
, hdrlen
, buf
, len
, 0);
2405 int force_object_loose(const unsigned char *sha1
, time_t mtime
)
2409 enum object_type type
;
2414 if (has_loose_object(sha1
))
2416 buf
= read_packed_sha1(sha1
, &type
, &len
);
2418 return error("cannot read sha1_file for %s", sha1_to_hex(sha1
));
2419 hdrlen
= sprintf(hdr
, "%s %lu", typename(type
), len
) + 1;
2420 ret
= write_loose_object(sha1
, hdr
, hdrlen
, buf
, len
, mtime
);
2426 int has_pack_index(const unsigned char *sha1
)
2429 if (stat(sha1_pack_index_name(sha1
), &st
))
2434 int has_sha1_pack(const unsigned char *sha1
)
2436 struct pack_entry e
;
2437 return find_pack_entry(sha1
, &e
);
2440 int has_sha1_file(const unsigned char *sha1
)
2442 struct pack_entry e
;
2444 if (find_pack_entry(sha1
, &e
))
2446 return has_loose_object(sha1
);
2449 static int index_mem(unsigned char *sha1
, void *buf
, size_t size
,
2450 int write_object
, enum object_type type
, const char *path
)
2452 int ret
, re_allocated
= 0;
2458 * Convert blobs to git internal format
2460 if ((type
== OBJ_BLOB
) && path
) {
2461 struct strbuf nbuf
= STRBUF_INIT
;
2462 if (convert_to_git(path
, buf
, size
, &nbuf
,
2463 write_object
? safe_crlf
: 0)) {
2464 buf
= strbuf_detach(&nbuf
, &size
);
2470 ret
= write_sha1_file(buf
, size
, typename(type
), sha1
);
2472 ret
= hash_sha1_file(buf
, size
, typename(type
), sha1
);
2478 #define SMALL_FILE_SIZE (32*1024)
2480 int index_fd(unsigned char *sha1
, int fd
, struct stat
*st
, int write_object
,
2481 enum object_type type
, const char *path
)
2484 size_t size
= xsize_t(st
->st_size
);
2486 if (!S_ISREG(st
->st_mode
)) {
2487 struct strbuf sbuf
= STRBUF_INIT
;
2488 if (strbuf_read(&sbuf
, fd
, 4096) >= 0)
2489 ret
= index_mem(sha1
, sbuf
.buf
, sbuf
.len
, write_object
,
2493 strbuf_release(&sbuf
);
2495 ret
= index_mem(sha1
, NULL
, size
, write_object
, type
, path
);
2496 } else if (size
<= SMALL_FILE_SIZE
) {
2497 char *buf
= xmalloc(size
);
2498 if (size
== read_in_full(fd
, buf
, size
))
2499 ret
= index_mem(sha1
, buf
, size
, write_object
, type
,
2502 ret
= error("short read %s", strerror(errno
));
2505 void *buf
= xmmap(NULL
, size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
2506 ret
= index_mem(sha1
, buf
, size
, write_object
, type
, path
);
2513 int index_path(unsigned char *sha1
, const char *path
, struct stat
*st
, int write_object
)
2516 struct strbuf sb
= STRBUF_INIT
;
2518 switch (st
->st_mode
& S_IFMT
) {
2520 fd
= open(path
, O_RDONLY
);
2522 return error("open(\"%s\"): %s", path
,
2524 if (index_fd(sha1
, fd
, st
, write_object
, OBJ_BLOB
, path
) < 0)
2525 return error("%s: failed to insert into database",
2529 if (strbuf_readlink(&sb
, path
, st
->st_size
)) {
2530 char *errstr
= strerror(errno
);
2531 return error("readlink(\"%s\"): %s", path
,
2535 hash_sha1_file(sb
.buf
, sb
.len
, blob_type
, sha1
);
2536 else if (write_sha1_file(sb
.buf
, sb
.len
, blob_type
, sha1
))
2537 return error("%s: failed to insert into database",
2539 strbuf_release(&sb
);
2542 return resolve_gitlink_ref(path
, "HEAD", sha1
);
2544 return error("%s: unsupported file type", path
);
2549 int read_pack_header(int fd
, struct pack_header
*header
)
2551 if (read_in_full(fd
, header
, sizeof(*header
)) < sizeof(*header
))
2552 /* "eof before pack header was fully read" */
2553 return PH_ERROR_EOF
;
2555 if (header
->hdr_signature
!= htonl(PACK_SIGNATURE
))
2556 /* "protocol error (pack signature mismatch detected)" */
2557 return PH_ERROR_PACK_SIGNATURE
;
2558 if (!pack_version_ok(header
->hdr_version
))
2559 /* "protocol error (pack version unsupported)" */
2560 return PH_ERROR_PROTOCOL
;
2564 void assert_sha1_type(const unsigned char *sha1
, enum object_type expect
)
2566 enum object_type type
= sha1_object_info(sha1
, NULL
);
2568 die("%s is not a valid object", sha1_to_hex(sha1
));
2570 die("%s is not a valid '%s' object", sha1_to_hex(sha1
),