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 const signed char hexval_table
[256] = {
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
42 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
45 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
46 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
47 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
51 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
68 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
69 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
70 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
73 int get_sha1_hex(const char *hex
, unsigned char *sha1
)
76 for (i
= 0; i
< 20; i
++) {
77 unsigned int val
= (hexval(hex
[0]) << 4) | hexval(hex
[1]);
86 static inline int offset_1st_component(const char *path
)
88 if (has_dos_drive_prefix(path
))
89 return 2 + (path
[2] == '/');
93 int safe_create_leading_directories(char *path
)
95 char *pos
= path
+ offset_1st_component(path
);
99 pos
= strchr(pos
, '/');
102 while (*++pos
== '/')
107 if (!stat(path
, &st
)) {
109 if (!S_ISDIR(st
.st_mode
)) {
114 else if (mkdir(path
, 0777)) {
118 else if (adjust_shared_perm(path
)) {
127 int safe_create_leading_directories_const(const char *path
)
129 /* path points to cache entries, so xstrdup before messing with it */
130 char *buf
= xstrdup(path
);
131 int result
= safe_create_leading_directories(buf
);
136 char *sha1_to_hex(const unsigned char *sha1
)
139 static char hexbuffer
[4][50];
140 static const char hex
[] = "0123456789abcdef";
141 char *buffer
= hexbuffer
[3 & ++bufno
], *buf
= buffer
;
144 for (i
= 0; i
< 20; i
++) {
145 unsigned int val
= *sha1
++;
146 *buf
++ = hex
[val
>> 4];
147 *buf
++ = hex
[val
& 0xf];
154 static void fill_sha1_path(char *pathbuf
, const unsigned char *sha1
)
157 for (i
= 0; i
< 20; i
++) {
158 static char hex
[] = "0123456789abcdef";
159 unsigned int val
= sha1
[i
];
160 char *pos
= pathbuf
+ i
*2 + (i
> 0);
161 *pos
++ = hex
[val
>> 4];
162 *pos
= hex
[val
& 0xf];
167 * NOTE! This returns a statically allocated buffer, so you have to be
168 * careful about using it. Do an "xstrdup()" if you need to save the
171 * Also note that this returns the location for creating. Reading
172 * SHA1 file can happen from any alternate directory listed in the
173 * DB_ENVIRONMENT environment variable if it is not found in
174 * the primary object database.
176 char *sha1_file_name(const unsigned char *sha1
)
178 static char *name
, *base
;
181 const char *sha1_file_directory
= get_object_directory();
182 int len
= strlen(sha1_file_directory
);
183 base
= xmalloc(len
+ 60);
184 memcpy(base
, sha1_file_directory
, len
);
185 memset(base
+len
, 0, 60);
188 name
= base
+ len
+ 1;
190 fill_sha1_path(name
, sha1
);
194 static char *sha1_get_pack_name(const unsigned char *sha1
,
195 char **name
, char **base
, const char *which
)
197 static const char hex
[] = "0123456789abcdef";
202 const char *sha1_file_directory
= get_object_directory();
203 int len
= strlen(sha1_file_directory
);
204 *base
= xmalloc(len
+ 60);
205 sprintf(*base
, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
206 sha1_file_directory
, which
);
207 *name
= *base
+ len
+ 11;
212 for (i
= 0; i
< 20; i
++) {
213 unsigned int val
= *sha1
++;
214 *buf
++ = hex
[val
>> 4];
215 *buf
++ = hex
[val
& 0xf];
221 char *sha1_pack_name(const unsigned char *sha1
)
223 static char *name
, *base
;
225 return sha1_get_pack_name(sha1
, &name
, &base
, "pack");
228 char *sha1_pack_index_name(const unsigned char *sha1
)
230 static char *name
, *base
;
232 return sha1_get_pack_name(sha1
, &name
, &base
, "idx");
235 struct alternate_object_database
*alt_odb_list
;
236 static struct alternate_object_database
**alt_odb_tail
;
238 static void read_info_alternates(const char * alternates
, int depth
);
241 * Prepare alternate object database registry.
243 * The variable alt_odb_list points at the list of struct
244 * alternate_object_database. The elements on this list come from
245 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
246 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
247 * whose contents is similar to that environment variable but can be
248 * LF separated. Its base points at a statically allocated buffer that
249 * contains "/the/directory/corresponding/to/.git/objects/...", while
250 * its name points just after the slash at the end of ".git/objects/"
251 * in the example above, and has enough space to hold 40-byte hex
252 * SHA1, an extra slash for the first level indirection, and the
255 static int link_alt_odb_entry(const char * entry
, int len
, const char * relative_base
, int depth
)
257 const char *objdir
= get_object_directory();
258 struct alternate_object_database
*ent
;
259 struct alternate_object_database
*alt
;
260 /* 43 = 40-byte + 2 '/' + terminating NUL */
262 int entlen
= pfxlen
+ 43;
265 if (!is_absolute_path(entry
) && relative_base
) {
266 /* Relative alt-odb */
268 base_len
= strlen(relative_base
) + 1;
272 ent
= xmalloc(sizeof(*ent
) + entlen
);
274 if (!is_absolute_path(entry
) && relative_base
) {
275 memcpy(ent
->base
, relative_base
, base_len
- 1);
276 ent
->base
[base_len
- 1] = '/';
277 memcpy(ent
->base
+ base_len
, entry
, len
);
280 memcpy(ent
->base
, entry
, pfxlen
);
282 ent
->name
= ent
->base
+ pfxlen
+ 1;
283 ent
->base
[pfxlen
+ 3] = '/';
284 ent
->base
[pfxlen
] = ent
->base
[entlen
-1] = 0;
286 /* Detect cases where alternate disappeared */
287 if (!is_directory(ent
->base
)) {
288 error("object directory %s does not exist; "
289 "check .git/objects/info/alternates.",
295 /* Prevent the common mistake of listing the same
296 * thing twice, or object directory itself.
298 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
299 if (!memcmp(ent
->base
, alt
->base
, pfxlen
)) {
304 if (!memcmp(ent
->base
, objdir
, pfxlen
)) {
309 /* add the alternate entry */
311 alt_odb_tail
= &(ent
->next
);
314 /* recursively add alternates */
315 read_info_alternates(ent
->base
, depth
+ 1);
317 ent
->base
[pfxlen
] = '/';
322 static void link_alt_odb_entries(const char *alt
, const char *ep
, int sep
,
323 const char *relative_base
, int depth
)
325 const char *cp
, *last
;
328 error("%s: ignoring alternate object stores, nesting too deep.",
336 if (cp
< ep
&& *cp
== '#') {
337 while (cp
< ep
&& *cp
!= sep
)
342 while (cp
< ep
&& *cp
!= sep
)
345 if (!is_absolute_path(last
) && depth
) {
346 error("%s: ignoring relative alternate object store %s",
347 relative_base
, last
);
349 link_alt_odb_entry(last
, cp
- last
,
350 relative_base
, depth
);
353 while (cp
< ep
&& *cp
== sep
)
359 static void read_info_alternates(const char * relative_base
, int depth
)
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
];
371 sprintf(path
, "%s/%s", relative_base
, alt_file_name
);
372 fd
= open(path
, O_RDONLY
);
375 if (fstat(fd
, &st
) || (st
.st_size
== 0)) {
379 mapsz
= xsize_t(st
.st_size
);
380 map
= xmmap(NULL
, mapsz
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
383 link_alt_odb_entries(map
, map
+ mapsz
, '\n', relative_base
, depth
);
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/objects\n", reference
);
393 write_or_die(fd
, alt
, strlen(alt
));
394 if (commit_lock_file(lock
))
395 die("could not close alternates file");
397 link_alt_odb_entries(alt
, alt
+ strlen(alt
), '\n', NULL
, 0);
400 void foreach_alt_odb(alt_odb_fn fn
, void *cb
)
402 struct alternate_object_database
*ent
;
405 for (ent
= alt_odb_list
; ent
; ent
= ent
->next
)
410 void prepare_alt_odb(void)
417 alt
= getenv(ALTERNATE_DB_ENVIRONMENT
);
420 alt_odb_tail
= &alt_odb_list
;
421 link_alt_odb_entries(alt
, 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
;
436 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
437 fill_sha1_path(alt
->name
, sha1
);
438 if (!access(alt
->base
, F_OK
))
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 size_t peak_pack_mapped
;
455 static size_t pack_mapped
;
456 struct packed_git
*packed_git
;
458 void pack_report(void)
461 "pack_report: getpagesize() = %10" SZ_FMT
"\n"
462 "pack_report: core.packedGitWindowSize = %10" SZ_FMT
"\n"
463 "pack_report: core.packedGitLimit = %10" SZ_FMT
"\n",
464 sz_fmt(getpagesize()),
465 sz_fmt(packed_git_window_size
),
466 sz_fmt(packed_git_limit
));
468 "pack_report: pack_used_ctr = %10u\n"
469 "pack_report: pack_mmap_calls = %10u\n"
470 "pack_report: pack_open_windows = %10u / %10u\n"
471 "pack_report: pack_mapped = "
472 "%10" SZ_FMT
" / %10" SZ_FMT
"\n",
475 pack_open_windows
, peak_pack_open_windows
,
476 sz_fmt(pack_mapped
), sz_fmt(peak_pack_mapped
));
479 static int check_packed_git_idx(const char *path
, struct packed_git
*p
)
482 struct pack_idx_header
*hdr
;
484 uint32_t version
, nr
, i
, *index
;
485 int fd
= open(path
, O_RDONLY
);
490 if (fstat(fd
, &st
)) {
494 idx_size
= xsize_t(st
.st_size
);
495 if (idx_size
< 4 * 256 + 20 + 20) {
497 return error("index file %s is too small", path
);
499 idx_map
= xmmap(NULL
, idx_size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
503 if (hdr
->idx_signature
== htonl(PACK_IDX_SIGNATURE
)) {
504 version
= ntohl(hdr
->idx_version
);
505 if (version
< 2 || version
> 2) {
506 munmap(idx_map
, idx_size
);
507 return error("index file %s is version %"PRIu32
508 " and is not supported by this binary"
509 " (try upgrading GIT to a newer version)",
518 index
+= 2; /* skip index header */
519 for (i
= 0; i
< 256; i
++) {
520 uint32_t n
= ntohl(index
[i
]);
522 munmap(idx_map
, idx_size
);
523 return error("non-monotonic index %s", path
);
531 * - 256 index entries 4 bytes each
532 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
533 * - 20-byte SHA1 of the packfile
534 * - 20-byte SHA1 file checksum
536 if (idx_size
!= 4*256 + nr
* 24 + 20 + 20) {
537 munmap(idx_map
, idx_size
);
538 return error("wrong index v1 file size in %s", path
);
540 } else if (version
== 2) {
543 * - 8 bytes of header
544 * - 256 index entries 4 bytes each
545 * - 20-byte sha1 entry * nr
546 * - 4-byte crc entry * nr
547 * - 4-byte offset entry * nr
548 * - 20-byte SHA1 of the packfile
549 * - 20-byte SHA1 file checksum
550 * And after the 4-byte offset table might be a
551 * variable sized table containing 8-byte entries
552 * for offsets larger than 2^31.
554 unsigned long min_size
= 8 + 4*256 + nr
*(20 + 4 + 4) + 20 + 20;
555 unsigned long max_size
= min_size
;
557 max_size
+= (nr
- 1)*8;
558 if (idx_size
< min_size
|| idx_size
> max_size
) {
559 munmap(idx_map
, idx_size
);
560 return error("wrong index v2 file size in %s", path
);
562 if (idx_size
!= min_size
&&
564 * make sure we can deal with large pack offsets.
565 * 31-bit signed offset won't be enough, neither
566 * 32-bit unsigned one will be.
568 (sizeof(off_t
) <= 4)) {
569 munmap(idx_map
, idx_size
);
570 return error("pack too large for current definition of off_t in %s", path
);
574 p
->index_version
= version
;
575 p
->index_data
= idx_map
;
576 p
->index_size
= idx_size
;
581 int open_pack_index(struct packed_git
*p
)
589 idx_name
= xstrdup(p
->pack_name
);
590 strcpy(idx_name
+ strlen(idx_name
) - strlen(".pack"), ".idx");
591 ret
= check_packed_git_idx(idx_name
, p
);
596 static void scan_windows(struct packed_git
*p
,
597 struct packed_git
**lru_p
,
598 struct pack_window
**lru_w
,
599 struct pack_window
**lru_l
)
601 struct pack_window
*w
, *w_l
;
603 for (w_l
= NULL
, w
= p
->windows
; w
; w
= w
->next
) {
605 if (!*lru_w
|| w
->last_used
< (*lru_w
)->last_used
) {
615 static int unuse_one_window(struct packed_git
*current
, int keep_fd
)
617 struct packed_git
*p
, *lru_p
= NULL
;
618 struct pack_window
*lru_w
= NULL
, *lru_l
= NULL
;
621 scan_windows(current
, &lru_p
, &lru_w
, &lru_l
);
622 for (p
= packed_git
; p
; p
= p
->next
)
623 scan_windows(p
, &lru_p
, &lru_w
, &lru_l
);
625 munmap(lru_w
->base
, lru_w
->len
);
626 pack_mapped
-= lru_w
->len
;
628 lru_l
->next
= lru_w
->next
;
630 lru_p
->windows
= lru_w
->next
;
631 if (!lru_p
->windows
&& lru_p
->pack_fd
!= keep_fd
) {
632 close(lru_p
->pack_fd
);
643 void release_pack_memory(size_t need
, int fd
)
645 size_t cur
= pack_mapped
;
646 while (need
>= (cur
- pack_mapped
) && unuse_one_window(NULL
, fd
))
650 void close_pack_windows(struct packed_git
*p
)
653 struct pack_window
*w
= p
->windows
;
656 die("pack '%s' still has open windows to it",
658 munmap(w
->base
, w
->len
);
659 pack_mapped
-= w
->len
;
661 p
->windows
= w
->next
;
666 void unuse_pack(struct pack_window
**w_cursor
)
668 struct pack_window
*w
= *w_cursor
;
676 * Do not call this directly as this leaks p->pack_fd on error return;
677 * call open_packed_git() instead.
679 static int open_packed_git_1(struct packed_git
*p
)
682 struct pack_header hdr
;
683 unsigned char sha1
[20];
684 unsigned char *idx_sha1
;
687 if (!p
->index_data
&& open_pack_index(p
))
688 return error("packfile %s index unavailable", p
->pack_name
);
690 p
->pack_fd
= open(p
->pack_name
, O_RDONLY
);
691 if (p
->pack_fd
< 0 || fstat(p
->pack_fd
, &st
))
694 /* If we created the struct before we had the pack we lack size. */
696 if (!S_ISREG(st
.st_mode
))
697 return error("packfile %s not a regular file", p
->pack_name
);
698 p
->pack_size
= st
.st_size
;
699 } else if (p
->pack_size
!= st
.st_size
)
700 return error("packfile %s size changed", p
->pack_name
);
702 /* We leave these file descriptors open with sliding mmap;
703 * there is no point keeping them open across exec(), though.
705 fd_flag
= fcntl(p
->pack_fd
, F_GETFD
, 0);
707 return error("cannot determine file descriptor flags");
708 fd_flag
|= FD_CLOEXEC
;
709 if (fcntl(p
->pack_fd
, F_SETFD
, fd_flag
) == -1)
710 return error("cannot set FD_CLOEXEC");
712 /* Verify we recognize this pack file format. */
713 if (read_in_full(p
->pack_fd
, &hdr
, sizeof(hdr
)) != sizeof(hdr
))
714 return error("file %s is far too short to be a packfile", p
->pack_name
);
715 if (hdr
.hdr_signature
!= htonl(PACK_SIGNATURE
))
716 return error("file %s is not a GIT packfile", p
->pack_name
);
717 if (!pack_version_ok(hdr
.hdr_version
))
718 return error("packfile %s is version %"PRIu32
" and not"
719 " supported (try upgrading GIT to a newer version)",
720 p
->pack_name
, ntohl(hdr
.hdr_version
));
722 /* Verify the pack matches its index. */
723 if (p
->num_objects
!= ntohl(hdr
.hdr_entries
))
724 return error("packfile %s claims to have %"PRIu32
" objects"
725 " while index indicates %"PRIu32
" objects",
726 p
->pack_name
, ntohl(hdr
.hdr_entries
),
728 if (lseek(p
->pack_fd
, p
->pack_size
- sizeof(sha1
), SEEK_SET
) == -1)
729 return error("end of packfile %s is unavailable", p
->pack_name
);
730 if (read_in_full(p
->pack_fd
, sha1
, sizeof(sha1
)) != sizeof(sha1
))
731 return error("packfile %s signature is unavailable", p
->pack_name
);
732 idx_sha1
= ((unsigned char *)p
->index_data
) + p
->index_size
- 40;
733 if (hashcmp(sha1
, idx_sha1
))
734 return error("packfile %s does not match index", p
->pack_name
);
738 static int open_packed_git(struct packed_git
*p
)
740 if (!open_packed_git_1(p
))
742 if (p
->pack_fd
!= -1) {
749 static int in_window(struct pack_window
*win
, off_t offset
)
751 /* We must promise at least 20 bytes (one hash) after the
752 * offset is available from this window, otherwise the offset
753 * is not actually in this window and a different window (which
754 * has that one hash excess) must be used. This is to support
755 * the object header and delta base parsing routines below.
757 off_t win_off
= win
->offset
;
758 return win_off
<= offset
759 && (offset
+ 20) <= (win_off
+ win
->len
);
762 unsigned char* use_pack(struct packed_git
*p
,
763 struct pack_window
**w_cursor
,
767 struct pack_window
*win
= *w_cursor
;
769 if (p
->pack_fd
== -1 && open_packed_git(p
))
770 die("packfile %s cannot be accessed", p
->pack_name
);
772 /* Since packfiles end in a hash of their content and its
773 * pointless to ask for an offset into the middle of that
774 * hash, and the in_window function above wouldn't match
775 * don't allow an offset too close to the end of the file.
777 if (offset
> (p
->pack_size
- 20))
778 die("offset beyond end of packfile (truncated pack?)");
780 if (!win
|| !in_window(win
, offset
)) {
783 for (win
= p
->windows
; win
; win
= win
->next
) {
784 if (in_window(win
, offset
))
788 size_t window_align
= packed_git_window_size
/ 2;
790 win
= xcalloc(1, sizeof(*win
));
791 win
->offset
= (offset
/ window_align
) * window_align
;
792 len
= p
->pack_size
- win
->offset
;
793 if (len
> packed_git_window_size
)
794 len
= packed_git_window_size
;
795 win
->len
= (size_t)len
;
796 pack_mapped
+= win
->len
;
797 while (packed_git_limit
< pack_mapped
798 && unuse_one_window(p
, p
->pack_fd
))
800 win
->base
= xmmap(NULL
, win
->len
,
801 PROT_READ
, MAP_PRIVATE
,
802 p
->pack_fd
, win
->offset
);
803 if (win
->base
== MAP_FAILED
)
804 die("packfile %s cannot be mapped: %s",
809 if (pack_mapped
> peak_pack_mapped
)
810 peak_pack_mapped
= pack_mapped
;
811 if (pack_open_windows
> peak_pack_open_windows
)
812 peak_pack_open_windows
= pack_open_windows
;
813 win
->next
= p
->windows
;
817 if (win
!= *w_cursor
) {
818 win
->last_used
= pack_used_ctr
++;
822 offset
-= win
->offset
;
824 *left
= win
->len
- xsize_t(offset
);
825 return win
->base
+ offset
;
828 static struct packed_git
*alloc_packed_git(int extra
)
830 struct packed_git
*p
= xmalloc(sizeof(*p
) + extra
);
831 memset(p
, 0, sizeof(*p
));
836 struct packed_git
*add_packed_git(const char *path
, int path_len
, int local
)
839 struct packed_git
*p
= alloc_packed_git(path_len
+ 2);
842 * Make sure a corresponding .pack file exists and that
843 * the index looks sane.
845 path_len
-= strlen(".idx");
850 memcpy(p
->pack_name
, path
, path_len
);
852 strcpy(p
->pack_name
+ path_len
, ".keep");
853 if (!access(p
->pack_name
, F_OK
))
856 strcpy(p
->pack_name
+ path_len
, ".pack");
857 if (stat(p
->pack_name
, &st
) || !S_ISREG(st
.st_mode
)) {
862 /* ok, it looks sane as far as we can check without
863 * actually mapping the pack file.
865 p
->pack_size
= st
.st_size
;
866 p
->pack_local
= local
;
867 p
->mtime
= st
.st_mtime
;
868 if (path_len
< 40 || get_sha1_hex(path
+ path_len
- 40, p
->sha1
))
873 struct packed_git
*parse_pack_index(unsigned char *sha1
)
875 const char *idx_path
= sha1_pack_index_name(sha1
);
876 const char *path
= sha1_pack_name(sha1
);
877 struct packed_git
*p
= alloc_packed_git(strlen(path
) + 1);
879 strcpy(p
->pack_name
, path
);
880 hashcpy(p
->sha1
, sha1
);
881 if (check_packed_git_idx(idx_path
, p
)) {
889 void install_packed_git(struct packed_git
*pack
)
891 pack
->next
= packed_git
;
895 static void prepare_packed_git_one(char *objdir
, int local
)
897 /* Ensure that this buffer is large enough so that we can
898 append "/pack/" without clobbering the stack even if
899 strlen(objdir) were PATH_MAX. */
900 char path
[PATH_MAX
+ 1 + 4 + 1 + 1];
905 sprintf(path
, "%s/pack", objdir
);
910 error("unable to open object pack directory: %s: %s",
911 path
, strerror(errno
));
915 while ((de
= readdir(dir
)) != NULL
) {
916 int namelen
= strlen(de
->d_name
);
917 struct packed_git
*p
;
919 if (!has_extension(de
->d_name
, ".idx"))
922 if (len
+ namelen
+ 1 > sizeof(path
))
925 /* Don't reopen a pack we already have. */
926 strcpy(path
+ len
, de
->d_name
);
927 for (p
= packed_git
; p
; p
= p
->next
) {
928 if (!memcmp(path
, p
->pack_name
, len
+ namelen
- 4))
933 /* See if it really is a valid .idx file with corresponding
934 * .pack file that we can map.
936 p
= add_packed_git(path
, len
+ namelen
, local
);
939 install_packed_git(p
);
944 static int sort_pack(const void *a_
, const void *b_
)
946 struct packed_git
*a
= *((struct packed_git
**)a_
);
947 struct packed_git
*b
= *((struct packed_git
**)b_
);
951 * Local packs tend to contain objects specific to our
952 * variant of the project than remote ones. In addition,
953 * remote ones could be on a network mounted filesystem.
954 * Favor local ones for these reasons.
956 st
= a
->pack_local
- b
->pack_local
;
961 * Younger packs tend to contain more recent objects,
962 * and more recent objects tend to get accessed more
965 if (a
->mtime
< b
->mtime
)
967 else if (a
->mtime
== b
->mtime
)
972 static void rearrange_packed_git(void)
974 struct packed_git
**ary
, *p
;
977 for (n
= 0, p
= packed_git
; p
; p
= p
->next
)
982 /* prepare an array of packed_git for easier sorting */
983 ary
= xcalloc(n
, sizeof(struct packed_git
*));
984 for (n
= 0, p
= packed_git
; p
; p
= p
->next
)
987 qsort(ary
, n
, sizeof(struct packed_git
*), sort_pack
);
989 /* link them back again */
990 for (i
= 0; i
< n
- 1; i
++)
991 ary
[i
]->next
= ary
[i
+ 1];
992 ary
[n
- 1]->next
= NULL
;
998 static int prepare_packed_git_run_once
= 0;
999 void prepare_packed_git(void)
1001 struct alternate_object_database
*alt
;
1003 if (prepare_packed_git_run_once
)
1005 prepare_packed_git_one(get_object_directory(), 1);
1007 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
1009 prepare_packed_git_one(alt
->base
, 0);
1010 alt
->name
[-1] = '/';
1012 rearrange_packed_git();
1013 prepare_packed_git_run_once
= 1;
1016 void reprepare_packed_git(void)
1019 prepare_packed_git_run_once
= 0;
1020 prepare_packed_git();
1023 static void mark_bad_packed_object(struct packed_git
*p
,
1024 const unsigned char *sha1
)
1027 for (i
= 0; i
< p
->num_bad_objects
; i
++)
1028 if (!hashcmp(sha1
, p
->bad_object_sha1
+ 20 * i
))
1030 p
->bad_object_sha1
= xrealloc(p
->bad_object_sha1
, 20 * (p
->num_bad_objects
+ 1));
1031 hashcpy(p
->bad_object_sha1
+ 20 * p
->num_bad_objects
, sha1
);
1032 p
->num_bad_objects
++;
1035 static int has_packed_and_bad(const unsigned char *sha1
)
1037 struct packed_git
*p
;
1040 for (p
= packed_git
; p
; p
= p
->next
)
1041 for (i
= 0; i
< p
->num_bad_objects
; i
++)
1042 if (!hashcmp(sha1
, p
->bad_object_sha1
+ 20 * i
))
1047 int check_sha1_signature(const unsigned char *sha1
, void *map
, unsigned long size
, const char *type
)
1049 unsigned char real_sha1
[20];
1050 hash_sha1_file(map
, size
, type
, real_sha1
);
1051 return hashcmp(sha1
, real_sha1
) ? -1 : 0;
1054 static int git_open_noatime(const char *name
)
1056 static int sha1_file_open_flag
= O_NOATIME
;
1057 int fd
= open(name
, O_RDONLY
| sha1_file_open_flag
);
1059 /* Might the failure be due to O_NOATIME? */
1060 if (fd
< 0 && errno
!= ENOENT
&& sha1_file_open_flag
) {
1061 fd
= open(name
, O_RDONLY
);
1063 sha1_file_open_flag
= 0;
1068 static int open_sha1_file(const unsigned char *sha1
)
1071 char *name
= sha1_file_name(sha1
);
1072 struct alternate_object_database
*alt
;
1074 fd
= git_open_noatime(name
);
1080 for (alt
= alt_odb_list
; alt
; alt
= alt
->next
) {
1082 fill_sha1_path(name
, sha1
);
1083 fd
= git_open_noatime(alt
->base
);
1090 static void *map_sha1_file(const unsigned char *sha1
, unsigned long *size
)
1095 fd
= open_sha1_file(sha1
);
1100 if (!fstat(fd
, &st
)) {
1101 *size
= xsize_t(st
.st_size
);
1102 map
= xmmap(NULL
, *size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
1109 static int legacy_loose_object(unsigned char *map
)
1114 * Is it a zlib-compressed buffer? If so, the first byte
1115 * must be 0x78 (15-bit window size, deflated), and the
1116 * first 16-bit word is evenly divisible by 31
1118 word
= (map
[0] << 8) + map
[1];
1119 if (map
[0] == 0x78 && !(word
% 31))
1125 unsigned long unpack_object_header_gently(const unsigned char *buf
, unsigned long len
, enum object_type
*type
, unsigned long *sizep
)
1130 unsigned long used
= 0;
1133 *type
= (c
>> 4) & 7;
1139 if (sizeof(long) * 8 <= shift
)
1142 size
+= (c
& 0x7f) << shift
;
1149 static int unpack_sha1_header(z_stream
*stream
, unsigned char *map
, unsigned long mapsize
, void *buffer
, unsigned long bufsiz
)
1151 unsigned long size
, used
;
1152 static const char valid_loose_object_type
[8] = {
1154 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1155 0, /* "delta" and others are invalid in a loose object */
1157 enum object_type type
;
1159 /* Get the data stream */
1160 memset(stream
, 0, sizeof(*stream
));
1161 stream
->next_in
= map
;
1162 stream
->avail_in
= mapsize
;
1163 stream
->next_out
= buffer
;
1164 stream
->avail_out
= bufsiz
;
1166 if (legacy_loose_object(map
)) {
1167 inflateInit(stream
);
1168 return inflate(stream
, 0);
1173 * There used to be a second loose object header format which
1174 * was meant to mimic the in-pack format, allowing for direct
1175 * copy of the object data. This format turned up not to be
1176 * really worth it and we don't write it any longer. But we
1177 * can still read it.
1179 used
= unpack_object_header_gently(map
, mapsize
, &type
, &size
);
1180 if (!used
|| !valid_loose_object_type
[type
])
1185 /* Set up the stream for the rest.. */
1186 stream
->next_in
= map
;
1187 stream
->avail_in
= mapsize
;
1188 inflateInit(stream
);
1190 /* And generate the fake traditional header */
1191 stream
->total_out
= 1 + snprintf(buffer
, bufsiz
, "%s %lu",
1192 typename(type
), size
);
1196 static void *unpack_sha1_rest(z_stream
*stream
, void *buffer
, unsigned long size
, const unsigned char *sha1
)
1198 int bytes
= strlen(buffer
) + 1;
1199 unsigned char *buf
= xmalloc(1+size
);
1203 n
= stream
->total_out
- bytes
;
1206 memcpy(buf
, (char *) buffer
+ bytes
, n
);
1208 if (bytes
<= size
) {
1210 * The above condition must be (bytes <= size), not
1211 * (bytes < size). In other words, even though we
1212 * expect no more output and set avail_out to zer0,
1213 * the input zlib stream may have bytes that express
1214 * "this concludes the stream", and we *do* want to
1217 * Otherwise we would not be able to test that we
1218 * consumed all the input to reach the expected size;
1219 * we also want to check that zlib tells us that all
1220 * went well with status == Z_STREAM_END at the end.
1222 stream
->next_out
= buf
+ bytes
;
1223 stream
->avail_out
= size
- bytes
;
1224 while (status
== Z_OK
)
1225 status
= inflate(stream
, Z_FINISH
);
1228 if (status
== Z_STREAM_END
&& !stream
->avail_in
) {
1234 error("corrupt loose object '%s'", sha1_to_hex(sha1
));
1235 else if (stream
->avail_in
)
1236 error("garbage at end of loose object '%s'",
1243 * We used to just use "sscanf()", but that's actually way
1244 * too permissive for what we want to check. So do an anal
1245 * object header parse by hand.
1247 static int parse_sha1_header(const char *hdr
, unsigned long *sizep
)
1254 * The type can be at most ten bytes (including the
1255 * terminating '\0' that we add), and is followed by
1264 if (i
>= sizeof(type
))
1270 * The length must follow immediately, and be in canonical
1271 * decimal format (ie "010" is not valid).
1273 size
= *hdr
++ - '0';
1278 unsigned long c
= *hdr
- '0';
1282 size
= size
* 10 + c
;
1288 * The length must be followed by a zero byte
1290 return *hdr
? -1 : type_from_string(type
);
1293 static void *unpack_sha1_file(void *map
, unsigned long mapsize
, enum object_type
*type
, unsigned long *size
, const unsigned char *sha1
)
1299 ret
= unpack_sha1_header(&stream
, map
, mapsize
, hdr
, sizeof(hdr
));
1300 if (ret
< Z_OK
|| (*type
= parse_sha1_header(hdr
, size
)) < 0)
1303 return unpack_sha1_rest(&stream
, hdr
, *size
, sha1
);
1306 unsigned long get_size_from_delta(struct packed_git
*p
,
1307 struct pack_window
**w_curs
,
1310 const unsigned char *data
;
1311 unsigned char delta_head
[20], *in
;
1315 memset(&stream
, 0, sizeof(stream
));
1316 stream
.next_out
= delta_head
;
1317 stream
.avail_out
= sizeof(delta_head
);
1319 inflateInit(&stream
);
1321 in
= use_pack(p
, w_curs
, curpos
, &stream
.avail_in
);
1322 stream
.next_in
= in
;
1323 st
= inflate(&stream
, Z_FINISH
);
1324 curpos
+= stream
.next_in
- in
;
1325 } while ((st
== Z_OK
|| st
== Z_BUF_ERROR
) &&
1326 stream
.total_out
< sizeof(delta_head
));
1327 inflateEnd(&stream
);
1328 if ((st
!= Z_STREAM_END
) && stream
.total_out
!= sizeof(delta_head
))
1329 die("delta data unpack-initial failed");
1331 /* Examine the initial part of the delta to figure out
1336 /* ignore base size */
1337 get_delta_hdr_size(&data
, delta_head
+sizeof(delta_head
));
1339 /* Read the result size */
1340 return get_delta_hdr_size(&data
, delta_head
+sizeof(delta_head
));
1343 static off_t
get_delta_base(struct packed_git
*p
,
1344 struct pack_window
**w_curs
,
1346 enum object_type type
,
1347 off_t delta_obj_offset
)
1349 unsigned char *base_info
= use_pack(p
, w_curs
, *curpos
, NULL
);
1352 /* use_pack() assured us we have [base_info, base_info + 20)
1353 * as a range that we can look at without walking off the
1354 * end of the mapped window. Its actually the hash size
1355 * that is assured. An OFS_DELTA longer than the hash size
1356 * is stupid, as then a REF_DELTA would be smaller to store.
1358 if (type
== OBJ_OFS_DELTA
) {
1360 unsigned char c
= base_info
[used
++];
1361 base_offset
= c
& 127;
1364 if (!base_offset
|| MSB(base_offset
, 7))
1365 return 0; /* overflow */
1366 c
= base_info
[used
++];
1367 base_offset
= (base_offset
<< 7) + (c
& 127);
1369 base_offset
= delta_obj_offset
- base_offset
;
1370 if (base_offset
>= delta_obj_offset
)
1371 return 0; /* out of bound */
1373 } else if (type
== OBJ_REF_DELTA
) {
1374 /* The base entry _must_ be in the same pack */
1375 base_offset
= find_pack_entry_one(base_info
, p
);
1378 die("I am totally screwed");
1382 /* forward declaration for a mutually recursive function */
1383 static int packed_object_info(struct packed_git
*p
, off_t offset
,
1384 unsigned long *sizep
);
1386 static int packed_delta_info(struct packed_git
*p
,
1387 struct pack_window
**w_curs
,
1389 enum object_type type
,
1391 unsigned long *sizep
)
1395 base_offset
= get_delta_base(p
, w_curs
, &curpos
, type
, obj_offset
);
1396 type
= packed_object_info(p
, base_offset
, NULL
);
1398 /* We choose to only get the type of the base object and
1399 * ignore potentially corrupt pack file that expects the delta
1400 * based on a base with a wrong size. This saves tons of
1404 *sizep
= get_size_from_delta(p
, w_curs
, curpos
);
1409 static int unpack_object_header(struct packed_git
*p
,
1410 struct pack_window
**w_curs
,
1412 unsigned long *sizep
)
1414 unsigned char *base
;
1417 enum object_type type
;
1419 /* use_pack() assures us we have [base, base + 20) available
1420 * as a range that we can look at at. (Its actually the hash
1421 * size that is assured.) With our object header encoding
1422 * the maximum deflated object size is 2^137, which is just
1423 * insane, so we know won't exceed what we have been given.
1425 base
= use_pack(p
, w_curs
, *curpos
, &left
);
1426 used
= unpack_object_header_gently(base
, left
, &type
, sizep
);
1428 die("object offset outside of pack file");
1434 const char *packed_object_info_detail(struct packed_git
*p
,
1436 unsigned long *size
,
1437 unsigned long *store_size
,
1438 unsigned int *delta_chain_length
,
1439 unsigned char *base_sha1
)
1441 struct pack_window
*w_curs
= NULL
;
1443 unsigned long dummy
;
1444 unsigned char *next_sha1
;
1445 enum object_type type
;
1446 struct revindex_entry
*revidx
;
1448 *delta_chain_length
= 0;
1449 curpos
= obj_offset
;
1450 type
= unpack_object_header(p
, &w_curs
, &curpos
, size
);
1452 revidx
= find_pack_revindex(p
, obj_offset
);
1453 *store_size
= revidx
[1].offset
- obj_offset
;
1458 die("pack %s contains unknown object type %d",
1459 p
->pack_name
, type
);
1464 unuse_pack(&w_curs
);
1465 return typename(type
);
1467 obj_offset
= get_delta_base(p
, &w_curs
, &curpos
, type
, obj_offset
);
1469 die("pack %s contains bad delta base reference of type %s",
1470 p
->pack_name
, typename(type
));
1471 if (*delta_chain_length
== 0) {
1472 revidx
= find_pack_revindex(p
, obj_offset
);
1473 hashcpy(base_sha1
, nth_packed_object_sha1(p
, revidx
->nr
));
1477 next_sha1
= use_pack(p
, &w_curs
, curpos
, NULL
);
1478 if (*delta_chain_length
== 0)
1479 hashcpy(base_sha1
, next_sha1
);
1480 obj_offset
= find_pack_entry_one(next_sha1
, p
);
1483 (*delta_chain_length
)++;
1484 curpos
= obj_offset
;
1485 type
= unpack_object_header(p
, &w_curs
, &curpos
, &dummy
);
1489 static int packed_object_info(struct packed_git
*p
, off_t obj_offset
,
1490 unsigned long *sizep
)
1492 struct pack_window
*w_curs
= NULL
;
1494 off_t curpos
= obj_offset
;
1495 enum object_type type
;
1497 type
= unpack_object_header(p
, &w_curs
, &curpos
, &size
);
1502 type
= packed_delta_info(p
, &w_curs
, curpos
,
1503 type
, obj_offset
, sizep
);
1513 die("pack %s contains unknown object type %d",
1514 p
->pack_name
, type
);
1516 unuse_pack(&w_curs
);
1520 static void *unpack_compressed_entry(struct packed_git
*p
,
1521 struct pack_window
**w_curs
,
1527 unsigned char *buffer
, *in
;
1529 buffer
= xmalloc(size
+ 1);
1531 memset(&stream
, 0, sizeof(stream
));
1532 stream
.next_out
= buffer
;
1533 stream
.avail_out
= size
;
1535 inflateInit(&stream
);
1537 in
= use_pack(p
, w_curs
, curpos
, &stream
.avail_in
);
1538 stream
.next_in
= in
;
1539 st
= inflate(&stream
, Z_FINISH
);
1540 curpos
+= stream
.next_in
- in
;
1541 } while (st
== Z_OK
|| st
== Z_BUF_ERROR
);
1542 inflateEnd(&stream
);
1543 if ((st
!= Z_STREAM_END
) || stream
.total_out
!= size
) {
1551 #define MAX_DELTA_CACHE (256)
1553 static size_t delta_base_cached
;
1555 static struct delta_base_cache_lru_list
{
1556 struct delta_base_cache_lru_list
*prev
;
1557 struct delta_base_cache_lru_list
*next
;
1558 } delta_base_cache_lru
= { &delta_base_cache_lru
, &delta_base_cache_lru
};
1560 static struct delta_base_cache_entry
{
1561 struct delta_base_cache_lru_list lru
;
1563 struct packed_git
*p
;
1566 enum object_type type
;
1567 } delta_base_cache
[MAX_DELTA_CACHE
];
1569 static unsigned long pack_entry_hash(struct packed_git
*p
, off_t base_offset
)
1573 hash
= (unsigned long)p
+ (unsigned long)base_offset
;
1574 hash
+= (hash
>> 8) + (hash
>> 16);
1575 return hash
% MAX_DELTA_CACHE
;
1578 static void *cache_or_unpack_entry(struct packed_git
*p
, off_t base_offset
,
1579 unsigned long *base_size
, enum object_type
*type
, int keep_cache
)
1582 unsigned long hash
= pack_entry_hash(p
, base_offset
);
1583 struct delta_base_cache_entry
*ent
= delta_base_cache
+ hash
;
1586 if (!ret
|| ent
->p
!= p
|| ent
->base_offset
!= base_offset
)
1587 return unpack_entry(p
, base_offset
, type
, base_size
);
1591 ent
->lru
.next
->prev
= ent
->lru
.prev
;
1592 ent
->lru
.prev
->next
= ent
->lru
.next
;
1593 delta_base_cached
-= ent
->size
;
1595 ret
= xmemdupz(ent
->data
, ent
->size
);
1598 *base_size
= ent
->size
;
1602 static inline void release_delta_base_cache(struct delta_base_cache_entry
*ent
)
1607 ent
->lru
.next
->prev
= ent
->lru
.prev
;
1608 ent
->lru
.prev
->next
= ent
->lru
.next
;
1609 delta_base_cached
-= ent
->size
;
1613 static void add_delta_base_cache(struct packed_git
*p
, off_t base_offset
,
1614 void *base
, unsigned long base_size
, enum object_type type
)
1616 unsigned long hash
= pack_entry_hash(p
, base_offset
);
1617 struct delta_base_cache_entry
*ent
= delta_base_cache
+ hash
;
1618 struct delta_base_cache_lru_list
*lru
;
1620 release_delta_base_cache(ent
);
1621 delta_base_cached
+= base_size
;
1623 for (lru
= delta_base_cache_lru
.next
;
1624 delta_base_cached
> delta_base_cache_limit
1625 && lru
!= &delta_base_cache_lru
;
1627 struct delta_base_cache_entry
*f
= (void *)lru
;
1628 if (f
->type
== OBJ_BLOB
)
1629 release_delta_base_cache(f
);
1631 for (lru
= delta_base_cache_lru
.next
;
1632 delta_base_cached
> delta_base_cache_limit
1633 && lru
!= &delta_base_cache_lru
;
1635 struct delta_base_cache_entry
*f
= (void *)lru
;
1636 release_delta_base_cache(f
);
1640 ent
->base_offset
= base_offset
;
1643 ent
->size
= base_size
;
1644 ent
->lru
.next
= &delta_base_cache_lru
;
1645 ent
->lru
.prev
= delta_base_cache_lru
.prev
;
1646 delta_base_cache_lru
.prev
->next
= &ent
->lru
;
1647 delta_base_cache_lru
.prev
= &ent
->lru
;
1650 static void *unpack_delta_entry(struct packed_git
*p
,
1651 struct pack_window
**w_curs
,
1653 unsigned long delta_size
,
1655 enum object_type
*type
,
1656 unsigned long *sizep
)
1658 void *delta_data
, *result
, *base
;
1659 unsigned long base_size
;
1662 base_offset
= get_delta_base(p
, w_curs
, &curpos
, *type
, obj_offset
);
1664 error("failed to validate delta base reference "
1665 "at offset %"PRIuMAX
" from %s",
1666 (uintmax_t)curpos
, p
->pack_name
);
1670 base
= cache_or_unpack_entry(p
, base_offset
, &base_size
, type
, 0);
1673 * We're probably in deep shit, but let's try to fetch
1674 * the required base anyway from another pack or loose.
1675 * This is costly but should happen only in the presence
1676 * of a corrupted pack, and is better than failing outright.
1678 struct revindex_entry
*revidx
= find_pack_revindex(p
, base_offset
);
1679 const unsigned char *base_sha1
=
1680 nth_packed_object_sha1(p
, revidx
->nr
);
1681 error("failed to read delta base object %s"
1682 " at offset %"PRIuMAX
" from %s",
1683 sha1_to_hex(base_sha1
), (uintmax_t)base_offset
,
1685 mark_bad_packed_object(p
, base_sha1
);
1686 base
= read_object(base_sha1
, type
, &base_size
);
1691 delta_data
= unpack_compressed_entry(p
, w_curs
, curpos
, delta_size
);
1693 error("failed to unpack compressed delta "
1694 "at offset %"PRIuMAX
" from %s",
1695 (uintmax_t)curpos
, p
->pack_name
);
1699 result
= patch_delta(base
, base_size
,
1700 delta_data
, delta_size
,
1703 die("failed to apply delta");
1705 add_delta_base_cache(p
, base_offset
, base
, base_size
, *type
);
1709 void *unpack_entry(struct packed_git
*p
, off_t obj_offset
,
1710 enum object_type
*type
, unsigned long *sizep
)
1712 struct pack_window
*w_curs
= NULL
;
1713 off_t curpos
= obj_offset
;
1716 *type
= unpack_object_header(p
, &w_curs
, &curpos
, sizep
);
1720 data
= unpack_delta_entry(p
, &w_curs
, curpos
, *sizep
,
1721 obj_offset
, type
, sizep
);
1727 data
= unpack_compressed_entry(p
, &w_curs
, curpos
, *sizep
);
1731 error("unknown object type %i at offset %"PRIuMAX
" in %s",
1732 *type
, (uintmax_t)obj_offset
, p
->pack_name
);
1734 unuse_pack(&w_curs
);
1738 const unsigned char *nth_packed_object_sha1(struct packed_git
*p
,
1741 const unsigned char *index
= p
->index_data
;
1743 if (open_pack_index(p
))
1745 index
= p
->index_data
;
1747 if (n
>= p
->num_objects
)
1750 if (p
->index_version
== 1) {
1751 return index
+ 24 * n
+ 4;
1754 return index
+ 20 * n
;
1758 off_t
nth_packed_object_offset(const struct packed_git
*p
, uint32_t n
)
1760 const unsigned char *index
= p
->index_data
;
1762 if (p
->index_version
== 1) {
1763 return ntohl(*((uint32_t *)(index
+ 24 * n
)));
1766 index
+= 8 + p
->num_objects
* (20 + 4);
1767 off
= ntohl(*((uint32_t *)(index
+ 4 * n
)));
1768 if (!(off
& 0x80000000))
1770 index
+= p
->num_objects
* 4 + (off
& 0x7fffffff) * 8;
1771 return (((uint64_t)ntohl(*((uint32_t *)(index
+ 0)))) << 32) |
1772 ntohl(*((uint32_t *)(index
+ 4)));
1776 off_t
find_pack_entry_one(const unsigned char *sha1
,
1777 struct packed_git
*p
)
1779 const uint32_t *level1_ofs
= p
->index_data
;
1780 const unsigned char *index
= p
->index_data
;
1781 unsigned hi
, lo
, stride
;
1782 static int use_lookup
= -1;
1783 static int debug_lookup
= -1;
1785 if (debug_lookup
< 0)
1786 debug_lookup
= !!getenv("GIT_DEBUG_LOOKUP");
1789 if (open_pack_index(p
))
1791 level1_ofs
= p
->index_data
;
1792 index
= p
->index_data
;
1794 if (p
->index_version
> 1) {
1799 hi
= ntohl(level1_ofs
[*sha1
]);
1800 lo
= ((*sha1
== 0x0) ? 0 : ntohl(level1_ofs
[*sha1
- 1]));
1801 if (p
->index_version
> 1) {
1809 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32
"\n",
1810 sha1
[0], sha1
[1], sha1
[2], lo
, hi
, p
->num_objects
);
1813 use_lookup
= !!getenv("GIT_USE_LOOKUP");
1815 int pos
= sha1_entry_pos(index
, stride
, 0,
1816 lo
, hi
, p
->num_objects
, sha1
);
1819 return nth_packed_object_offset(p
, pos
);
1823 unsigned mi
= (lo
+ hi
) / 2;
1824 int cmp
= hashcmp(index
+ mi
* stride
, sha1
);
1827 printf("lo %u hi %u rg %u mi %u\n",
1828 lo
, hi
, hi
- lo
, mi
);
1830 return nth_packed_object_offset(p
, mi
);
1839 int matches_pack_name(struct packed_git
*p
, const char *name
)
1841 const char *last_c
, *c
;
1843 if (!strcmp(p
->pack_name
, name
))
1846 for (c
= p
->pack_name
, last_c
= c
; *c
;)
1851 if (!strcmp(last_c
, name
))
1857 static int find_pack_entry(const unsigned char *sha1
, struct pack_entry
*e
, const char **ignore_packed
)
1859 static struct packed_git
*last_found
= (void *)1;
1860 struct packed_git
*p
;
1863 prepare_packed_git();
1866 p
= (last_found
== (void *)1) ? packed_git
: last_found
;
1869 if (ignore_packed
) {
1871 for (ig
= ignore_packed
; *ig
; ig
++)
1872 if (matches_pack_name(p
, *ig
))
1878 if (p
->num_bad_objects
) {
1880 for (i
= 0; i
< p
->num_bad_objects
; i
++)
1881 if (!hashcmp(sha1
, p
->bad_object_sha1
+ 20 * i
))
1885 offset
= find_pack_entry_one(sha1
, p
);
1888 * We are about to tell the caller where they can
1889 * locate the requested object. We better make
1890 * sure the packfile is still here and can be
1891 * accessed before supplying that answer, as
1892 * it may have been deleted since the index
1895 if (p
->pack_fd
== -1 && open_packed_git(p
)) {
1896 error("packfile %s cannot be accessed", p
->pack_name
);
1901 hashcpy(e
->sha1
, sha1
);
1907 if (p
== last_found
)
1911 if (p
== last_found
)
1917 struct packed_git
*find_sha1_pack(const unsigned char *sha1
,
1918 struct packed_git
*packs
)
1920 struct packed_git
*p
;
1922 for (p
= packs
; p
; p
= p
->next
) {
1923 if (find_pack_entry_one(sha1
, p
))
1930 static int sha1_loose_object_info(const unsigned char *sha1
, unsigned long *sizep
)
1933 unsigned long mapsize
, size
;
1938 map
= map_sha1_file(sha1
, &mapsize
);
1940 return error("unable to find %s", sha1_to_hex(sha1
));
1941 if (unpack_sha1_header(&stream
, map
, mapsize
, hdr
, sizeof(hdr
)) < 0)
1942 status
= error("unable to unpack %s header",
1944 else if ((status
= parse_sha1_header(hdr
, &size
)) < 0)
1945 status
= error("unable to parse %s header", sha1_to_hex(sha1
));
1948 inflateEnd(&stream
);
1949 munmap(map
, mapsize
);
1953 int sha1_object_info(const unsigned char *sha1
, unsigned long *sizep
)
1955 struct pack_entry e
;
1958 if (!find_pack_entry(sha1
, &e
, NULL
)) {
1959 /* Most likely it's a loose object. */
1960 status
= sha1_loose_object_info(sha1
, sizep
);
1964 /* Not a loose object; someone else may have just packed it. */
1965 reprepare_packed_git();
1966 if (!find_pack_entry(sha1
, &e
, NULL
))
1969 return packed_object_info(e
.p
, e
.offset
, sizep
);
1972 static void *read_packed_sha1(const unsigned char *sha1
,
1973 enum object_type
*type
, unsigned long *size
)
1975 struct pack_entry e
;
1978 if (!find_pack_entry(sha1
, &e
, NULL
))
1980 data
= cache_or_unpack_entry(e
.p
, e
.offset
, size
, type
, 1);
1983 * We're probably in deep shit, but let's try to fetch
1984 * the required object anyway from another pack or loose.
1985 * This should happen only in the presence of a corrupted
1986 * pack, and is better than failing outright.
1988 error("failed to read object %s at offset %"PRIuMAX
" from %s",
1989 sha1_to_hex(sha1
), (uintmax_t)e
.offset
, e
.p
->pack_name
);
1990 mark_bad_packed_object(e
.p
, sha1
);
1991 data
= read_object(sha1
, type
, size
);
1997 * This is meant to hold a *small* number of objects that you would
1998 * want read_sha1_file() to be able to return, but yet you do not want
1999 * to write them into the object store (e.g. a browse-only
2002 static struct cached_object
{
2003 unsigned char sha1
[20];
2004 enum object_type type
;
2008 static int cached_object_nr
, cached_object_alloc
;
2010 static struct cached_object empty_tree
= {
2011 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
2012 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
2013 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
2019 static struct cached_object
*find_cached_object(const unsigned char *sha1
)
2022 struct cached_object
*co
= cached_objects
;
2024 for (i
= 0; i
< cached_object_nr
; i
++, co
++) {
2025 if (!hashcmp(co
->sha1
, sha1
))
2028 if (!hashcmp(sha1
, empty_tree
.sha1
))
2033 int pretend_sha1_file(void *buf
, unsigned long len
, enum object_type type
,
2034 unsigned char *sha1
)
2036 struct cached_object
*co
;
2038 hash_sha1_file(buf
, len
, typename(type
), sha1
);
2039 if (has_sha1_file(sha1
) || find_cached_object(sha1
))
2041 if (cached_object_alloc
<= cached_object_nr
) {
2042 cached_object_alloc
= alloc_nr(cached_object_alloc
);
2043 cached_objects
= xrealloc(cached_objects
,
2044 sizeof(*cached_objects
) *
2045 cached_object_alloc
);
2047 co
= &cached_objects
[cached_object_nr
++];
2050 co
->buf
= xmalloc(len
);
2051 memcpy(co
->buf
, buf
, len
);
2052 hashcpy(co
->sha1
, sha1
);
2056 void *read_object(const unsigned char *sha1
, enum object_type
*type
,
2057 unsigned long *size
)
2059 unsigned long mapsize
;
2061 struct cached_object
*co
;
2063 co
= find_cached_object(sha1
);
2067 return xmemdupz(co
->buf
, co
->size
);
2070 buf
= read_packed_sha1(sha1
, type
, size
);
2073 map
= map_sha1_file(sha1
, &mapsize
);
2075 buf
= unpack_sha1_file(map
, mapsize
, type
, size
, sha1
);
2076 munmap(map
, mapsize
);
2079 reprepare_packed_git();
2080 return read_packed_sha1(sha1
, type
, size
);
2083 void *read_sha1_file(const unsigned char *sha1
, enum object_type
*type
,
2084 unsigned long *size
)
2086 void *data
= read_object(sha1
, type
, size
);
2087 /* legacy behavior is to die on corrupted objects */
2088 if (!data
&& (has_loose_object(sha1
) || has_packed_and_bad(sha1
)))
2089 die("object %s is corrupted", sha1_to_hex(sha1
));
2093 void *read_object_with_reference(const unsigned char *sha1
,
2094 const char *required_type_name
,
2095 unsigned long *size
,
2096 unsigned char *actual_sha1_return
)
2098 enum object_type type
, required_type
;
2100 unsigned long isize
;
2101 unsigned char actual_sha1
[20];
2103 required_type
= type_from_string(required_type_name
);
2104 hashcpy(actual_sha1
, sha1
);
2106 int ref_length
= -1;
2107 const char *ref_type
= NULL
;
2109 buffer
= read_sha1_file(actual_sha1
, &type
, &isize
);
2112 if (type
== required_type
) {
2114 if (actual_sha1_return
)
2115 hashcpy(actual_sha1_return
, actual_sha1
);
2118 /* Handle references */
2119 else if (type
== OBJ_COMMIT
)
2121 else if (type
== OBJ_TAG
)
2122 ref_type
= "object ";
2127 ref_length
= strlen(ref_type
);
2129 if (ref_length
+ 40 > isize
||
2130 memcmp(buffer
, ref_type
, ref_length
) ||
2131 get_sha1_hex((char *) buffer
+ ref_length
, actual_sha1
)) {
2136 /* Now we have the ID of the referred-to object in
2137 * actual_sha1. Check again. */
2141 static void write_sha1_file_prepare(const void *buf
, unsigned long len
,
2142 const char *type
, unsigned char *sha1
,
2143 char *hdr
, int *hdrlen
)
2147 /* Generate the header */
2148 *hdrlen
= sprintf(hdr
, "%s %lu", type
, len
)+1;
2152 git_SHA1_Update(&c
, hdr
, *hdrlen
);
2153 git_SHA1_Update(&c
, buf
, len
);
2154 git_SHA1_Final(sha1
, &c
);
2158 * Move the just written object into its final resting place
2160 int move_temp_to_file(const char *tmpfile
, const char *filename
)
2163 if (link(tmpfile
, filename
))
2167 * Coda hack - coda doesn't like cross-directory links,
2168 * so we fall back to a rename, which will mean that it
2169 * won't be able to check collisions, but that's not a
2172 * The same holds for FAT formatted media.
2174 * When this succeeds, we just return 0. We have nothing
2177 if (ret
&& ret
!= EEXIST
) {
2178 if (!rename(tmpfile
, filename
))
2184 if (ret
!= EEXIST
) {
2185 return error("unable to write sha1 filename %s: %s\n", filename
, strerror(ret
));
2187 /* FIXME!!! Collision check here ? */
2193 static int write_buffer(int fd
, const void *buf
, size_t len
)
2195 if (write_in_full(fd
, buf
, len
) < 0)
2196 return error("file write error (%s)", strerror(errno
));
2200 int hash_sha1_file(const void *buf
, unsigned long len
, const char *type
,
2201 unsigned char *sha1
)
2205 write_sha1_file_prepare(buf
, len
, type
, sha1
, hdr
, &hdrlen
);
2209 /* Finalize a file on disk, and close it. */
2210 static void close_sha1_file(int fd
)
2212 if (fsync_object_files
)
2213 fsync_or_die(fd
, "sha1 file");
2216 die("unable to write sha1 file");
2219 /* Size of directory component, including the ending '/' */
2220 static inline int directory_size(const char *filename
)
2222 const char *s
= strrchr(filename
, '/');
2225 return s
- filename
+ 1;
2229 * This creates a temporary file in the same directory as the final
2232 * We want to avoid cross-directory filename renames, because those
2233 * can have problems on various filesystems (FAT, NFS, Coda).
2235 static int create_tmpfile(char *buffer
, size_t bufsiz
, const char *filename
)
2237 int fd
, dirlen
= directory_size(filename
);
2239 if (dirlen
+ 20 > bufsiz
) {
2240 errno
= ENAMETOOLONG
;
2243 memcpy(buffer
, filename
, dirlen
);
2244 strcpy(buffer
+ dirlen
, "tmp_obj_XXXXXX");
2245 fd
= mkstemp(buffer
);
2246 if (fd
< 0 && dirlen
) {
2247 /* Make sure the directory exists */
2248 memcpy(buffer
, filename
, dirlen
);
2249 buffer
[dirlen
-1] = 0;
2250 if (mkdir(buffer
, 0777) || adjust_shared_perm(buffer
))
2254 strcpy(buffer
+ dirlen
- 1, "/tmp_obj_XXXXXX");
2255 fd
= mkstemp(buffer
);
2260 static int write_loose_object(const unsigned char *sha1
, char *hdr
, int hdrlen
,
2261 void *buf
, unsigned long len
, time_t mtime
)
2264 unsigned char *compressed
;
2267 static char tmpfile
[PATH_MAX
];
2269 filename
= sha1_file_name(sha1
);
2270 fd
= create_tmpfile(tmpfile
, sizeof(tmpfile
), filename
);
2273 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2275 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile
, strerror(errno
));
2279 memset(&stream
, 0, sizeof(stream
));
2280 deflateInit(&stream
, zlib_compression_level
);
2281 size
= 8 + deflateBound(&stream
, len
+hdrlen
);
2282 compressed
= xmalloc(size
);
2285 stream
.next_out
= compressed
;
2286 stream
.avail_out
= size
;
2288 /* First header.. */
2289 stream
.next_in
= (unsigned char *)hdr
;
2290 stream
.avail_in
= hdrlen
;
2291 while (deflate(&stream
, 0) == Z_OK
)
2294 /* Then the data itself.. */
2295 stream
.next_in
= buf
;
2296 stream
.avail_in
= len
;
2297 ret
= deflate(&stream
, Z_FINISH
);
2298 if (ret
!= Z_STREAM_END
)
2299 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1
), ret
);
2301 ret
= deflateEnd(&stream
);
2303 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1
), ret
);
2305 size
= stream
.total_out
;
2307 if (write_buffer(fd
, compressed
, size
) < 0)
2308 die("unable to write sha1 file");
2309 close_sha1_file(fd
);
2315 utb
.modtime
= mtime
;
2316 if (utime(tmpfile
, &utb
) < 0)
2317 warning("failed utime() on %s: %s",
2318 tmpfile
, strerror(errno
));
2321 return move_temp_to_file(tmpfile
, filename
);
2324 int write_sha1_file(void *buf
, unsigned long len
, const char *type
, unsigned char *returnsha1
)
2326 unsigned char sha1
[20];
2330 /* Normally if we have it in the pack then we do not bother writing
2331 * it out into .git/objects/??/?{38} file.
2333 write_sha1_file_prepare(buf
, len
, type
, sha1
, hdr
, &hdrlen
);
2335 hashcpy(returnsha1
, sha1
);
2336 if (has_sha1_file(sha1
))
2338 return write_loose_object(sha1
, hdr
, hdrlen
, buf
, len
, 0);
2341 int force_object_loose(const unsigned char *sha1
, time_t mtime
)
2345 enum object_type type
;
2350 if (has_loose_object(sha1
))
2352 buf
= read_packed_sha1(sha1
, &type
, &len
);
2354 return error("cannot read sha1_file for %s", sha1_to_hex(sha1
));
2355 hdrlen
= sprintf(hdr
, "%s %lu", typename(type
), len
) + 1;
2356 ret
= write_loose_object(sha1
, hdr
, hdrlen
, buf
, len
, mtime
);
2362 int has_pack_index(const unsigned char *sha1
)
2365 if (stat(sha1_pack_index_name(sha1
), &st
))
2370 int has_pack_file(const unsigned char *sha1
)
2373 if (stat(sha1_pack_name(sha1
), &st
))
2378 int has_sha1_pack(const unsigned char *sha1
, const char **ignore_packed
)
2380 struct pack_entry e
;
2381 return find_pack_entry(sha1
, &e
, ignore_packed
);
2384 int has_sha1_file(const unsigned char *sha1
)
2386 struct pack_entry e
;
2388 if (find_pack_entry(sha1
, &e
, NULL
))
2390 return has_loose_object(sha1
);
2393 static int index_mem(unsigned char *sha1
, void *buf
, size_t size
,
2394 int write_object
, enum object_type type
, const char *path
)
2396 int ret
, re_allocated
= 0;
2402 * Convert blobs to git internal format
2404 if ((type
== OBJ_BLOB
) && path
) {
2405 struct strbuf nbuf
= STRBUF_INIT
;
2406 if (convert_to_git(path
, buf
, size
, &nbuf
,
2407 write_object
? safe_crlf
: 0)) {
2408 buf
= strbuf_detach(&nbuf
, &size
);
2414 ret
= write_sha1_file(buf
, size
, typename(type
), sha1
);
2416 ret
= hash_sha1_file(buf
, size
, typename(type
), sha1
);
2422 int index_fd(unsigned char *sha1
, int fd
, struct stat
*st
, int write_object
,
2423 enum object_type type
, const char *path
)
2426 size_t size
= xsize_t(st
->st_size
);
2428 if (!S_ISREG(st
->st_mode
)) {
2429 struct strbuf sbuf
= STRBUF_INIT
;
2430 if (strbuf_read(&sbuf
, fd
, 4096) >= 0)
2431 ret
= index_mem(sha1
, sbuf
.buf
, sbuf
.len
, write_object
,
2435 strbuf_release(&sbuf
);
2437 void *buf
= xmmap(NULL
, size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
2438 ret
= index_mem(sha1
, buf
, size
, write_object
, type
, path
);
2441 ret
= index_mem(sha1
, NULL
, size
, write_object
, type
, path
);
2446 int index_path(unsigned char *sha1
, const char *path
, struct stat
*st
, int write_object
)
2452 switch (st
->st_mode
& S_IFMT
) {
2454 fd
= open(path
, O_RDONLY
);
2456 return error("open(\"%s\"): %s", path
,
2458 if (index_fd(sha1
, fd
, st
, write_object
, OBJ_BLOB
, path
) < 0)
2459 return error("%s: failed to insert into database",
2463 len
= xsize_t(st
->st_size
);
2464 target
= xmalloc(len
+ 1);
2465 if (readlink(path
, target
, len
+ 1) != st
->st_size
) {
2466 char *errstr
= strerror(errno
);
2468 return error("readlink(\"%s\"): %s", path
,
2472 hash_sha1_file(target
, len
, blob_type
, sha1
);
2473 else if (write_sha1_file(target
, len
, blob_type
, sha1
))
2474 return error("%s: failed to insert into database",
2479 return resolve_gitlink_ref(path
, "HEAD", sha1
);
2481 return error("%s: unsupported file type", path
);
2486 int read_pack_header(int fd
, struct pack_header
*header
)
2488 if (read_in_full(fd
, header
, sizeof(*header
)) < sizeof(*header
))
2489 /* "eof before pack header was fully read" */
2490 return PH_ERROR_EOF
;
2492 if (header
->hdr_signature
!= htonl(PACK_SIGNATURE
))
2493 /* "protocol error (pack signature mismatch detected)" */
2494 return PH_ERROR_PACK_SIGNATURE
;
2495 if (!pack_version_ok(header
->hdr_version
))
2496 /* "protocol error (pack version unsupported)" */
2497 return PH_ERROR_PROTOCOL
;