gitk: Second try to work around the command line limit on Windows
[git/dscho.git] / sha1_file.c
blob28c056e074d1a89e4a3d266eff49c899bfd35e59
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "delta.h"
11 #include "pack.h"
12 #include "blob.h"
13 #include "commit.h"
14 #include "tag.h"
15 #include "tree.h"
16 #include "refs.h"
17 #include "pack-revindex.h"
18 #include "sha1-lookup.h"
20 #ifndef O_NOATIME
21 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
22 #define O_NOATIME 01000000
23 #else
24 #define O_NOATIME 0
25 #endif
26 #endif
28 #ifdef NO_C99_FORMAT
29 #define SZ_FMT "lu"
30 static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
31 #else
32 #define SZ_FMT "zu"
33 static size_t sz_fmt(size_t s) { return s; }
34 #endif
36 const unsigned char null_sha1[20];
38 int safe_create_leading_directories(char *path)
40 char *pos = path + offset_1st_component(path);
41 struct stat st;
43 while (pos) {
44 pos = strchr(pos, '/');
45 if (!pos)
46 break;
47 while (*++pos == '/')
49 if (!*pos)
50 break;
51 *--pos = '\0';
52 if (!stat(path, &st)) {
53 /* path exists */
54 if (!S_ISDIR(st.st_mode)) {
55 *pos = '/';
56 return -3;
59 else if (mkdir(path, 0777)) {
60 *pos = '/';
61 return -1;
63 else if (adjust_shared_perm(path)) {
64 *pos = '/';
65 return -2;
67 *pos++ = '/';
69 return 0;
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);
77 free(buf);
78 return result;
81 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
83 int i;
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
96 * filename.
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 *name, *base;
107 if (!base) {
108 const char *sha1_file_directory = get_object_directory();
109 int len = strlen(sha1_file_directory);
110 base = xmalloc(len + 60);
111 memcpy(base, sha1_file_directory, len);
112 memset(base+len, 0, 60);
113 base[len] = '/';
114 base[len+3] = '/';
115 name = base + len + 1;
117 fill_sha1_path(name, sha1);
118 return base;
121 static char *sha1_get_pack_name(const unsigned char *sha1,
122 char **name, char **base, const char *which)
124 static const char hex[] = "0123456789abcdef";
125 char *buf;
126 int i;
128 if (!*base) {
129 const char *sha1_file_directory = get_object_directory();
130 int len = strlen(sha1_file_directory);
131 *base = xmalloc(len + 60);
132 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
133 sha1_file_directory, which);
134 *name = *base + len + 11;
137 buf = *name;
139 for (i = 0; i < 20; i++) {
140 unsigned int val = *sha1++;
141 *buf++ = hex[val >> 4];
142 *buf++ = hex[val & 0xf];
145 return *base;
148 char *sha1_pack_name(const unsigned char *sha1)
150 static char *name, *base;
152 return sha1_get_pack_name(sha1, &name, &base, "pack");
155 char *sha1_pack_index_name(const unsigned char *sha1)
157 static char *name, *base;
159 return sha1_get_pack_name(sha1, &name, &base, "idx");
162 struct alternate_object_database *alt_odb_list;
163 static struct alternate_object_database **alt_odb_tail;
165 static void read_info_alternates(const char * alternates, int depth);
168 * Prepare alternate object database registry.
170 * The variable alt_odb_list points at the list of struct
171 * alternate_object_database. The elements on this list come from
172 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
173 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
174 * whose contents is similar to that environment variable but can be
175 * LF separated. Its base points at a statically allocated buffer that
176 * contains "/the/directory/corresponding/to/.git/objects/...", while
177 * its name points just after the slash at the end of ".git/objects/"
178 * in the example above, and has enough space to hold 40-byte hex
179 * SHA1, an extra slash for the first level indirection, and the
180 * terminating NUL.
182 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
184 const char *objdir = get_object_directory();
185 struct alternate_object_database *ent;
186 struct alternate_object_database *alt;
187 /* 43 = 40-byte + 2 '/' + terminating NUL */
188 int pfxlen = len;
189 int entlen = pfxlen + 43;
190 int base_len = -1;
192 if (!is_absolute_path(entry) && relative_base) {
193 /* Relative alt-odb */
194 if (base_len < 0)
195 base_len = strlen(relative_base) + 1;
196 entlen += base_len;
197 pfxlen += base_len;
199 ent = xmalloc(sizeof(*ent) + entlen);
201 if (!is_absolute_path(entry) && relative_base) {
202 memcpy(ent->base, relative_base, base_len - 1);
203 ent->base[base_len - 1] = '/';
204 memcpy(ent->base + base_len, entry, len);
206 else
207 memcpy(ent->base, entry, pfxlen);
209 ent->name = ent->base + pfxlen + 1;
210 ent->base[pfxlen + 3] = '/';
211 ent->base[pfxlen] = ent->base[entlen-1] = 0;
213 /* Detect cases where alternate disappeared */
214 if (!is_directory(ent->base)) {
215 error("object directory %s does not exist; "
216 "check .git/objects/info/alternates.",
217 ent->base);
218 free(ent);
219 return -1;
222 /* Prevent the common mistake of listing the same
223 * thing twice, or object directory itself.
225 for (alt = alt_odb_list; alt; alt = alt->next) {
226 if (!memcmp(ent->base, alt->base, pfxlen)) {
227 free(ent);
228 return -1;
231 if (!memcmp(ent->base, objdir, pfxlen)) {
232 free(ent);
233 return -1;
236 /* add the alternate entry */
237 *alt_odb_tail = ent;
238 alt_odb_tail = &(ent->next);
239 ent->next = NULL;
241 /* recursively add alternates */
242 read_info_alternates(ent->base, depth + 1);
244 ent->base[pfxlen] = '/';
246 return 0;
249 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
250 const char *relative_base, int depth)
252 const char *cp, *last;
254 if (depth > 5) {
255 error("%s: ignoring alternate object stores, nesting too deep.",
256 relative_base);
257 return;
260 last = alt;
261 while (last < ep) {
262 cp = last;
263 if (cp < ep && *cp == '#') {
264 while (cp < ep && *cp != sep)
265 cp++;
266 last = cp + 1;
267 continue;
269 while (cp < ep && *cp != sep)
270 cp++;
271 if (last != cp) {
272 if (!is_absolute_path(last) && depth) {
273 error("%s: ignoring relative alternate object store %s",
274 relative_base, last);
275 } else {
276 link_alt_odb_entry(last, cp - last,
277 relative_base, depth);
280 while (cp < ep && *cp == sep)
281 cp++;
282 last = cp;
286 static void read_info_alternates(const char * relative_base, int depth)
288 char *map;
289 size_t mapsz;
290 struct stat st;
291 const char alt_file_name[] = "info/alternates";
292 /* Given that relative_base is no longer than PATH_MAX,
293 ensure that "path" has enough space to append "/", the
294 file name, "info/alternates", and a trailing NUL. */
295 char path[PATH_MAX + 1 + sizeof alt_file_name];
296 int fd;
298 sprintf(path, "%s/%s", relative_base, alt_file_name);
299 fd = open(path, O_RDONLY);
300 if (fd < 0)
301 return;
302 if (fstat(fd, &st) || (st.st_size == 0)) {
303 close(fd);
304 return;
306 mapsz = xsize_t(st.st_size);
307 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
308 close(fd);
310 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
312 munmap(map, mapsz);
315 void add_to_alternates_file(const char *reference)
317 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
318 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
319 char *alt = mkpath("%s/objects\n", reference);
320 write_or_die(fd, alt, strlen(alt));
321 if (commit_lock_file(lock))
322 die("could not close alternates file");
323 if (alt_odb_tail)
324 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
327 void foreach_alt_odb(alt_odb_fn fn, void *cb)
329 struct alternate_object_database *ent;
331 prepare_alt_odb();
332 for (ent = alt_odb_list; ent; ent = ent->next)
333 if (fn(ent, cb))
334 return;
337 void prepare_alt_odb(void)
339 const char *alt;
341 if (alt_odb_tail)
342 return;
344 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
345 if (!alt) alt = "";
347 alt_odb_tail = &alt_odb_list;
348 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
350 read_info_alternates(get_object_directory(), 0);
353 static int has_loose_object_local(const unsigned char *sha1)
355 char *name = sha1_file_name(sha1);
356 return !access(name, F_OK);
359 int has_loose_object_nonlocal(const unsigned char *sha1)
361 struct alternate_object_database *alt;
362 prepare_alt_odb();
363 for (alt = alt_odb_list; alt; alt = alt->next) {
364 fill_sha1_path(alt->name, sha1);
365 if (!access(alt->base, F_OK))
366 return 1;
368 return 0;
371 static int has_loose_object(const unsigned char *sha1)
373 return has_loose_object_local(sha1) ||
374 has_loose_object_nonlocal(sha1);
377 static unsigned int pack_used_ctr;
378 static unsigned int pack_mmap_calls;
379 static unsigned int peak_pack_open_windows;
380 static unsigned int pack_open_windows;
381 static size_t peak_pack_mapped;
382 static size_t pack_mapped;
383 struct packed_git *packed_git;
385 void pack_report(void)
387 fprintf(stderr,
388 "pack_report: getpagesize() = %10" SZ_FMT "\n"
389 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
390 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
391 sz_fmt(getpagesize()),
392 sz_fmt(packed_git_window_size),
393 sz_fmt(packed_git_limit));
394 fprintf(stderr,
395 "pack_report: pack_used_ctr = %10u\n"
396 "pack_report: pack_mmap_calls = %10u\n"
397 "pack_report: pack_open_windows = %10u / %10u\n"
398 "pack_report: pack_mapped = "
399 "%10" SZ_FMT " / %10" SZ_FMT "\n",
400 pack_used_ctr,
401 pack_mmap_calls,
402 pack_open_windows, peak_pack_open_windows,
403 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
406 static int check_packed_git_idx(const char *path, struct packed_git *p)
408 void *idx_map;
409 struct pack_idx_header *hdr;
410 size_t idx_size;
411 uint32_t version, nr, i, *index;
412 int fd = open(path, O_RDONLY);
413 struct stat st;
415 if (fd < 0)
416 return -1;
417 if (fstat(fd, &st)) {
418 close(fd);
419 return -1;
421 idx_size = xsize_t(st.st_size);
422 if (idx_size < 4 * 256 + 20 + 20) {
423 close(fd);
424 return error("index file %s is too small", path);
426 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
427 close(fd);
429 hdr = idx_map;
430 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
431 version = ntohl(hdr->idx_version);
432 if (version < 2 || version > 2) {
433 munmap(idx_map, idx_size);
434 return error("index file %s is version %"PRIu32
435 " and is not supported by this binary"
436 " (try upgrading GIT to a newer version)",
437 path, version);
439 } else
440 version = 1;
442 nr = 0;
443 index = idx_map;
444 if (version > 1)
445 index += 2; /* skip index header */
446 for (i = 0; i < 256; i++) {
447 uint32_t n = ntohl(index[i]);
448 if (n < nr) {
449 munmap(idx_map, idx_size);
450 return error("non-monotonic index %s", path);
452 nr = n;
455 if (version == 1) {
457 * Total size:
458 * - 256 index entries 4 bytes each
459 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
460 * - 20-byte SHA1 of the packfile
461 * - 20-byte SHA1 file checksum
463 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
464 munmap(idx_map, idx_size);
465 return error("wrong index v1 file size in %s", path);
467 } else if (version == 2) {
469 * Minimum size:
470 * - 8 bytes of header
471 * - 256 index entries 4 bytes each
472 * - 20-byte sha1 entry * nr
473 * - 4-byte crc entry * nr
474 * - 4-byte offset entry * nr
475 * - 20-byte SHA1 of the packfile
476 * - 20-byte SHA1 file checksum
477 * And after the 4-byte offset table might be a
478 * variable sized table containing 8-byte entries
479 * for offsets larger than 2^31.
481 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
482 unsigned long max_size = min_size;
483 if (nr)
484 max_size += (nr - 1)*8;
485 if (idx_size < min_size || idx_size > max_size) {
486 munmap(idx_map, idx_size);
487 return error("wrong index v2 file size in %s", path);
489 if (idx_size != min_size &&
491 * make sure we can deal with large pack offsets.
492 * 31-bit signed offset won't be enough, neither
493 * 32-bit unsigned one will be.
495 (sizeof(off_t) <= 4)) {
496 munmap(idx_map, idx_size);
497 return error("pack too large for current definition of off_t in %s", path);
501 p->index_version = version;
502 p->index_data = idx_map;
503 p->index_size = idx_size;
504 p->num_objects = nr;
505 return 0;
508 int open_pack_index(struct packed_git *p)
510 char *idx_name;
511 int ret;
513 if (p->index_data)
514 return 0;
516 idx_name = xstrdup(p->pack_name);
517 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
518 ret = check_packed_git_idx(idx_name, p);
519 free(idx_name);
520 return ret;
523 static void scan_windows(struct packed_git *p,
524 struct packed_git **lru_p,
525 struct pack_window **lru_w,
526 struct pack_window **lru_l)
528 struct pack_window *w, *w_l;
530 for (w_l = NULL, w = p->windows; w; w = w->next) {
531 if (!w->inuse_cnt) {
532 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
533 *lru_p = p;
534 *lru_w = w;
535 *lru_l = w_l;
538 w_l = w;
542 static int unuse_one_window(struct packed_git *current, int keep_fd)
544 struct packed_git *p, *lru_p = NULL;
545 struct pack_window *lru_w = NULL, *lru_l = NULL;
547 if (current)
548 scan_windows(current, &lru_p, &lru_w, &lru_l);
549 for (p = packed_git; p; p = p->next)
550 scan_windows(p, &lru_p, &lru_w, &lru_l);
551 if (lru_p) {
552 munmap(lru_w->base, lru_w->len);
553 pack_mapped -= lru_w->len;
554 if (lru_l)
555 lru_l->next = lru_w->next;
556 else {
557 lru_p->windows = lru_w->next;
558 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
559 close(lru_p->pack_fd);
560 lru_p->pack_fd = -1;
563 free(lru_w);
564 pack_open_windows--;
565 return 1;
567 return 0;
570 void release_pack_memory(size_t need, int fd)
572 size_t cur = pack_mapped;
573 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
574 ; /* nothing */
577 void close_pack_windows(struct packed_git *p)
579 while (p->windows) {
580 struct pack_window *w = p->windows;
582 if (w->inuse_cnt)
583 die("pack '%s' still has open windows to it",
584 p->pack_name);
585 munmap(w->base, w->len);
586 pack_mapped -= w->len;
587 pack_open_windows--;
588 p->windows = w->next;
589 free(w);
593 void unuse_pack(struct pack_window **w_cursor)
595 struct pack_window *w = *w_cursor;
596 if (w) {
597 w->inuse_cnt--;
598 *w_cursor = NULL;
603 * This is used by git-repack in case a newly created pack happens to
604 * contain the same set of objects as an existing one. In that case
605 * the resulting file might be different even if its name would be the
606 * same. It is best to close any reference to the old pack before it is
607 * replaced on disk. Of course no index pointers nor windows for given pack
608 * must subsist at this point. If ever objects from this pack are requested
609 * again, the new version of the pack will be reinitialized through
610 * reprepare_packed_git().
612 void free_pack_by_name(const char *pack_name)
614 struct packed_git *p, **pp = &packed_git;
616 while (*pp) {
617 p = *pp;
618 if (strcmp(pack_name, p->pack_name) == 0) {
619 clear_delta_base_cache();
620 close_pack_windows(p);
621 if (p->pack_fd != -1)
622 close(p->pack_fd);
623 if (p->index_data)
624 munmap((void *)p->index_data, p->index_size);
625 free(p->bad_object_sha1);
626 *pp = p->next;
627 free(p);
628 return;
630 pp = &p->next;
635 * Do not call this directly as this leaks p->pack_fd on error return;
636 * call open_packed_git() instead.
638 static int open_packed_git_1(struct packed_git *p)
640 struct stat st;
641 struct pack_header hdr;
642 unsigned char sha1[20];
643 unsigned char *idx_sha1;
644 long fd_flag;
646 if (!p->index_data && open_pack_index(p))
647 return error("packfile %s index unavailable", p->pack_name);
649 p->pack_fd = open(p->pack_name, O_RDONLY);
650 while (p->pack_fd < 0 && errno == EMFILE && unuse_one_window(p, -1))
651 p->pack_fd = open(p->pack_name, O_RDONLY);
652 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
653 return -1;
655 /* If we created the struct before we had the pack we lack size. */
656 if (!p->pack_size) {
657 if (!S_ISREG(st.st_mode))
658 return error("packfile %s not a regular file", p->pack_name);
659 p->pack_size = st.st_size;
660 } else if (p->pack_size != st.st_size)
661 return error("packfile %s size changed", p->pack_name);
663 /* We leave these file descriptors open with sliding mmap;
664 * there is no point keeping them open across exec(), though.
666 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
667 if (fd_flag < 0)
668 return error("cannot determine file descriptor flags");
669 fd_flag |= FD_CLOEXEC;
670 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
671 return error("cannot set FD_CLOEXEC");
673 /* Verify we recognize this pack file format. */
674 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
675 return error("file %s is far too short to be a packfile", p->pack_name);
676 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
677 return error("file %s is not a GIT packfile", p->pack_name);
678 if (!pack_version_ok(hdr.hdr_version))
679 return error("packfile %s is version %"PRIu32" and not"
680 " supported (try upgrading GIT to a newer version)",
681 p->pack_name, ntohl(hdr.hdr_version));
683 /* Verify the pack matches its index. */
684 if (p->num_objects != ntohl(hdr.hdr_entries))
685 return error("packfile %s claims to have %"PRIu32" objects"
686 " while index indicates %"PRIu32" objects",
687 p->pack_name, ntohl(hdr.hdr_entries),
688 p->num_objects);
689 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
690 return error("end of packfile %s is unavailable", p->pack_name);
691 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
692 return error("packfile %s signature is unavailable", p->pack_name);
693 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
694 if (hashcmp(sha1, idx_sha1))
695 return error("packfile %s does not match index", p->pack_name);
696 return 0;
699 static int open_packed_git(struct packed_git *p)
701 if (!open_packed_git_1(p))
702 return 0;
703 if (p->pack_fd != -1) {
704 close(p->pack_fd);
705 p->pack_fd = -1;
707 return -1;
710 static int in_window(struct pack_window *win, off_t offset)
712 /* We must promise at least 20 bytes (one hash) after the
713 * offset is available from this window, otherwise the offset
714 * is not actually in this window and a different window (which
715 * has that one hash excess) must be used. This is to support
716 * the object header and delta base parsing routines below.
718 off_t win_off = win->offset;
719 return win_off <= offset
720 && (offset + 20) <= (win_off + win->len);
723 unsigned char *use_pack(struct packed_git *p,
724 struct pack_window **w_cursor,
725 off_t offset,
726 unsigned int *left)
728 struct pack_window *win = *w_cursor;
730 if (p->pack_fd == -1 && open_packed_git(p))
731 die("packfile %s cannot be accessed", p->pack_name);
733 /* Since packfiles end in a hash of their content and it's
734 * pointless to ask for an offset into the middle of that
735 * hash, and the in_window function above wouldn't match
736 * don't allow an offset too close to the end of the file.
738 if (offset > (p->pack_size - 20))
739 die("offset beyond end of packfile (truncated pack?)");
741 if (!win || !in_window(win, offset)) {
742 if (win)
743 win->inuse_cnt--;
744 for (win = p->windows; win; win = win->next) {
745 if (in_window(win, offset))
746 break;
748 if (!win) {
749 size_t window_align = packed_git_window_size / 2;
750 off_t len;
751 win = xcalloc(1, sizeof(*win));
752 win->offset = (offset / window_align) * window_align;
753 len = p->pack_size - win->offset;
754 if (len > packed_git_window_size)
755 len = packed_git_window_size;
756 win->len = (size_t)len;
757 pack_mapped += win->len;
758 while (packed_git_limit < pack_mapped
759 && unuse_one_window(p, p->pack_fd))
760 ; /* nothing */
761 win->base = xmmap(NULL, win->len,
762 PROT_READ, MAP_PRIVATE,
763 p->pack_fd, win->offset);
764 if (win->base == MAP_FAILED)
765 die("packfile %s cannot be mapped: %s",
766 p->pack_name,
767 strerror(errno));
768 pack_mmap_calls++;
769 pack_open_windows++;
770 if (pack_mapped > peak_pack_mapped)
771 peak_pack_mapped = pack_mapped;
772 if (pack_open_windows > peak_pack_open_windows)
773 peak_pack_open_windows = pack_open_windows;
774 win->next = p->windows;
775 p->windows = win;
778 if (win != *w_cursor) {
779 win->last_used = pack_used_ctr++;
780 win->inuse_cnt++;
781 *w_cursor = win;
783 offset -= win->offset;
784 if (left)
785 *left = win->len - xsize_t(offset);
786 return win->base + offset;
789 static struct packed_git *alloc_packed_git(int extra)
791 struct packed_git *p = xmalloc(sizeof(*p) + extra);
792 memset(p, 0, sizeof(*p));
793 p->pack_fd = -1;
794 return p;
797 struct packed_git *add_packed_git(const char *path, int path_len, int local)
799 struct stat st;
800 struct packed_git *p = alloc_packed_git(path_len + 2);
803 * Make sure a corresponding .pack file exists and that
804 * the index looks sane.
806 path_len -= strlen(".idx");
807 if (path_len < 1) {
808 free(p);
809 return NULL;
811 memcpy(p->pack_name, path, path_len);
813 strcpy(p->pack_name + path_len, ".keep");
814 if (!access(p->pack_name, F_OK))
815 p->pack_keep = 1;
817 strcpy(p->pack_name + path_len, ".pack");
818 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
819 free(p);
820 return NULL;
823 /* ok, it looks sane as far as we can check without
824 * actually mapping the pack file.
826 p->pack_size = st.st_size;
827 p->pack_local = local;
828 p->mtime = st.st_mtime;
829 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
830 hashclr(p->sha1);
831 return p;
834 struct packed_git *parse_pack_index(unsigned char *sha1)
836 const char *idx_path = sha1_pack_index_name(sha1);
837 const char *path = sha1_pack_name(sha1);
838 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
840 strcpy(p->pack_name, path);
841 hashcpy(p->sha1, sha1);
842 if (check_packed_git_idx(idx_path, p)) {
843 free(p);
844 return NULL;
847 return p;
850 void install_packed_git(struct packed_git *pack)
852 pack->next = packed_git;
853 packed_git = pack;
856 static void prepare_packed_git_one(char *objdir, int local)
858 /* Ensure that this buffer is large enough so that we can
859 append "/pack/" without clobbering the stack even if
860 strlen(objdir) were PATH_MAX. */
861 char path[PATH_MAX + 1 + 4 + 1 + 1];
862 int len;
863 DIR *dir;
864 struct dirent *de;
866 sprintf(path, "%s/pack", objdir);
867 len = strlen(path);
868 dir = opendir(path);
869 while (!dir && errno == EMFILE && unuse_one_window(packed_git, -1))
870 dir = opendir(path);
871 if (!dir) {
872 if (errno != ENOENT)
873 error("unable to open object pack directory: %s: %s",
874 path, strerror(errno));
875 return;
877 path[len++] = '/';
878 while ((de = readdir(dir)) != NULL) {
879 int namelen = strlen(de->d_name);
880 struct packed_git *p;
882 if (!has_extension(de->d_name, ".idx"))
883 continue;
885 if (len + namelen + 1 > sizeof(path))
886 continue;
888 /* Don't reopen a pack we already have. */
889 strcpy(path + len, de->d_name);
890 for (p = packed_git; p; p = p->next) {
891 if (!memcmp(path, p->pack_name, len + namelen - 4))
892 break;
894 if (p)
895 continue;
896 /* See if it really is a valid .idx file with corresponding
897 * .pack file that we can map.
899 p = add_packed_git(path, len + namelen, local);
900 if (!p)
901 continue;
902 install_packed_git(p);
904 closedir(dir);
907 static int sort_pack(const void *a_, const void *b_)
909 struct packed_git *a = *((struct packed_git **)a_);
910 struct packed_git *b = *((struct packed_git **)b_);
911 int st;
914 * Local packs tend to contain objects specific to our
915 * variant of the project than remote ones. In addition,
916 * remote ones could be on a network mounted filesystem.
917 * Favor local ones for these reasons.
919 st = a->pack_local - b->pack_local;
920 if (st)
921 return -st;
924 * Younger packs tend to contain more recent objects,
925 * and more recent objects tend to get accessed more
926 * often.
928 if (a->mtime < b->mtime)
929 return 1;
930 else if (a->mtime == b->mtime)
931 return 0;
932 return -1;
935 static void rearrange_packed_git(void)
937 struct packed_git **ary, *p;
938 int i, n;
940 for (n = 0, p = packed_git; p; p = p->next)
941 n++;
942 if (n < 2)
943 return;
945 /* prepare an array of packed_git for easier sorting */
946 ary = xcalloc(n, sizeof(struct packed_git *));
947 for (n = 0, p = packed_git; p; p = p->next)
948 ary[n++] = p;
950 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
952 /* link them back again */
953 for (i = 0; i < n - 1; i++)
954 ary[i]->next = ary[i + 1];
955 ary[n - 1]->next = NULL;
956 packed_git = ary[0];
958 free(ary);
961 static int prepare_packed_git_run_once = 0;
962 void prepare_packed_git(void)
964 struct alternate_object_database *alt;
966 if (prepare_packed_git_run_once)
967 return;
968 prepare_packed_git_one(get_object_directory(), 1);
969 prepare_alt_odb();
970 for (alt = alt_odb_list; alt; alt = alt->next) {
971 alt->name[-1] = 0;
972 prepare_packed_git_one(alt->base, 0);
973 alt->name[-1] = '/';
975 rearrange_packed_git();
976 prepare_packed_git_run_once = 1;
979 void reprepare_packed_git(void)
981 discard_revindex();
982 prepare_packed_git_run_once = 0;
983 prepare_packed_git();
986 static void mark_bad_packed_object(struct packed_git *p,
987 const unsigned char *sha1)
989 unsigned i;
990 for (i = 0; i < p->num_bad_objects; i++)
991 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
992 return;
993 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
994 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
995 p->num_bad_objects++;
998 static int has_packed_and_bad(const unsigned char *sha1)
1000 struct packed_git *p;
1001 unsigned i;
1003 for (p = packed_git; p; p = p->next)
1004 for (i = 0; i < p->num_bad_objects; i++)
1005 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1006 return 1;
1007 return 0;
1010 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
1012 unsigned char real_sha1[20];
1013 hash_sha1_file(map, size, type, real_sha1);
1014 return hashcmp(sha1, real_sha1) ? -1 : 0;
1017 static int git_open_noatime(const char *name)
1019 static int sha1_file_open_flag = O_NOATIME;
1020 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1022 /* Might the failure be due to O_NOATIME? */
1023 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1024 fd = open(name, O_RDONLY);
1025 if (fd >= 0)
1026 sha1_file_open_flag = 0;
1028 return fd;
1031 static int open_sha1_file(const unsigned char *sha1)
1033 int fd;
1034 char *name = sha1_file_name(sha1);
1035 struct alternate_object_database *alt;
1037 fd = git_open_noatime(name);
1038 if (fd >= 0)
1039 return fd;
1041 prepare_alt_odb();
1042 errno = ENOENT;
1043 for (alt = alt_odb_list; alt; alt = alt->next) {
1044 name = alt->name;
1045 fill_sha1_path(name, sha1);
1046 fd = git_open_noatime(alt->base);
1047 if (fd >= 0)
1048 return fd;
1050 return -1;
1053 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1055 void *map;
1056 int fd;
1058 fd = open_sha1_file(sha1);
1059 map = NULL;
1060 if (fd >= 0) {
1061 struct stat st;
1063 if (!fstat(fd, &st)) {
1064 *size = xsize_t(st.st_size);
1065 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1067 close(fd);
1069 return map;
1072 static int legacy_loose_object(unsigned char *map)
1074 unsigned int word;
1077 * Is it a zlib-compressed buffer? If so, the first byte
1078 * must be 0x78 (15-bit window size, deflated), and the
1079 * first 16-bit word is evenly divisible by 31
1081 word = (map[0] << 8) + map[1];
1082 if (map[0] == 0x78 && !(word % 31))
1083 return 1;
1084 else
1085 return 0;
1088 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1089 unsigned long len, enum object_type *type, unsigned long *sizep)
1091 unsigned shift;
1092 unsigned long size, c;
1093 unsigned long used = 0;
1095 c = buf[used++];
1096 *type = (c >> 4) & 7;
1097 size = c & 15;
1098 shift = 4;
1099 while (c & 0x80) {
1100 if (len <= used || bitsizeof(long) <= shift) {
1101 error("bad object header");
1102 return 0;
1104 c = buf[used++];
1105 size += (c & 0x7f) << shift;
1106 shift += 7;
1108 *sizep = size;
1109 return used;
1112 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1114 unsigned long size, used;
1115 static const char valid_loose_object_type[8] = {
1116 0, /* OBJ_EXT */
1117 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1118 0, /* "delta" and others are invalid in a loose object */
1120 enum object_type type;
1122 /* Get the data stream */
1123 memset(stream, 0, sizeof(*stream));
1124 stream->next_in = map;
1125 stream->avail_in = mapsize;
1126 stream->next_out = buffer;
1127 stream->avail_out = bufsiz;
1129 if (legacy_loose_object(map)) {
1130 git_inflate_init(stream);
1131 return git_inflate(stream, 0);
1136 * There used to be a second loose object header format which
1137 * was meant to mimic the in-pack format, allowing for direct
1138 * copy of the object data. This format turned up not to be
1139 * really worth it and we don't write it any longer. But we
1140 * can still read it.
1142 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1143 if (!used || !valid_loose_object_type[type])
1144 return -1;
1145 map += used;
1146 mapsize -= used;
1148 /* Set up the stream for the rest.. */
1149 stream->next_in = map;
1150 stream->avail_in = mapsize;
1151 git_inflate_init(stream);
1153 /* And generate the fake traditional header */
1154 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1155 typename(type), size);
1156 return 0;
1159 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1161 int bytes = strlen(buffer) + 1;
1162 unsigned char *buf = xmallocz(size);
1163 unsigned long n;
1164 int status = Z_OK;
1166 n = stream->total_out - bytes;
1167 if (n > size)
1168 n = size;
1169 memcpy(buf, (char *) buffer + bytes, n);
1170 bytes = n;
1171 if (bytes <= size) {
1173 * The above condition must be (bytes <= size), not
1174 * (bytes < size). In other words, even though we
1175 * expect no more output and set avail_out to zer0,
1176 * the input zlib stream may have bytes that express
1177 * "this concludes the stream", and we *do* want to
1178 * eat that input.
1180 * Otherwise we would not be able to test that we
1181 * consumed all the input to reach the expected size;
1182 * we also want to check that zlib tells us that all
1183 * went well with status == Z_STREAM_END at the end.
1185 stream->next_out = buf + bytes;
1186 stream->avail_out = size - bytes;
1187 while (status == Z_OK)
1188 status = git_inflate(stream, Z_FINISH);
1190 if (status == Z_STREAM_END && !stream->avail_in) {
1191 git_inflate_end(stream);
1192 return buf;
1195 if (status < 0)
1196 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1197 else if (stream->avail_in)
1198 error("garbage at end of loose object '%s'",
1199 sha1_to_hex(sha1));
1200 free(buf);
1201 return NULL;
1205 * We used to just use "sscanf()", but that's actually way
1206 * too permissive for what we want to check. So do an anal
1207 * object header parse by hand.
1209 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1211 char type[10];
1212 int i;
1213 unsigned long size;
1216 * The type can be at most ten bytes (including the
1217 * terminating '\0' that we add), and is followed by
1218 * a space.
1220 i = 0;
1221 for (;;) {
1222 char c = *hdr++;
1223 if (c == ' ')
1224 break;
1225 type[i++] = c;
1226 if (i >= sizeof(type))
1227 return -1;
1229 type[i] = 0;
1232 * The length must follow immediately, and be in canonical
1233 * decimal format (ie "010" is not valid).
1235 size = *hdr++ - '0';
1236 if (size > 9)
1237 return -1;
1238 if (size) {
1239 for (;;) {
1240 unsigned long c = *hdr - '0';
1241 if (c > 9)
1242 break;
1243 hdr++;
1244 size = size * 10 + c;
1247 *sizep = size;
1250 * The length must be followed by a zero byte
1252 return *hdr ? -1 : type_from_string(type);
1255 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1257 int ret;
1258 z_stream stream;
1259 char hdr[8192];
1261 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1262 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1263 return NULL;
1265 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1268 unsigned long get_size_from_delta(struct packed_git *p,
1269 struct pack_window **w_curs,
1270 off_t curpos)
1272 const unsigned char *data;
1273 unsigned char delta_head[20], *in;
1274 z_stream stream;
1275 int st;
1277 memset(&stream, 0, sizeof(stream));
1278 stream.next_out = delta_head;
1279 stream.avail_out = sizeof(delta_head);
1281 git_inflate_init(&stream);
1282 do {
1283 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1284 stream.next_in = in;
1285 st = git_inflate(&stream, Z_FINISH);
1286 curpos += stream.next_in - in;
1287 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1288 stream.total_out < sizeof(delta_head));
1289 git_inflate_end(&stream);
1290 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1291 error("delta data unpack-initial failed");
1292 return 0;
1295 /* Examine the initial part of the delta to figure out
1296 * the result size.
1298 data = delta_head;
1300 /* ignore base size */
1301 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1303 /* Read the result size */
1304 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1307 static off_t get_delta_base(struct packed_git *p,
1308 struct pack_window **w_curs,
1309 off_t *curpos,
1310 enum object_type type,
1311 off_t delta_obj_offset)
1313 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1314 off_t base_offset;
1316 /* use_pack() assured us we have [base_info, base_info + 20)
1317 * as a range that we can look at without walking off the
1318 * end of the mapped window. Its actually the hash size
1319 * that is assured. An OFS_DELTA longer than the hash size
1320 * is stupid, as then a REF_DELTA would be smaller to store.
1322 if (type == OBJ_OFS_DELTA) {
1323 unsigned used = 0;
1324 unsigned char c = base_info[used++];
1325 base_offset = c & 127;
1326 while (c & 128) {
1327 base_offset += 1;
1328 if (!base_offset || MSB(base_offset, 7))
1329 return 0; /* overflow */
1330 c = base_info[used++];
1331 base_offset = (base_offset << 7) + (c & 127);
1333 base_offset = delta_obj_offset - base_offset;
1334 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1335 return 0; /* out of bound */
1336 *curpos += used;
1337 } else if (type == OBJ_REF_DELTA) {
1338 /* The base entry _must_ be in the same pack */
1339 base_offset = find_pack_entry_one(base_info, p);
1340 *curpos += 20;
1341 } else
1342 die("I am totally screwed");
1343 return base_offset;
1346 /* forward declaration for a mutually recursive function */
1347 static int packed_object_info(struct packed_git *p, off_t offset,
1348 unsigned long *sizep);
1350 static int packed_delta_info(struct packed_git *p,
1351 struct pack_window **w_curs,
1352 off_t curpos,
1353 enum object_type type,
1354 off_t obj_offset,
1355 unsigned long *sizep)
1357 off_t base_offset;
1359 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1360 if (!base_offset)
1361 return OBJ_BAD;
1362 type = packed_object_info(p, base_offset, NULL);
1363 if (type <= OBJ_NONE) {
1364 struct revindex_entry *revidx;
1365 const unsigned char *base_sha1;
1366 revidx = find_pack_revindex(p, base_offset);
1367 if (!revidx)
1368 return OBJ_BAD;
1369 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1370 mark_bad_packed_object(p, base_sha1);
1371 type = sha1_object_info(base_sha1, NULL);
1372 if (type <= OBJ_NONE)
1373 return OBJ_BAD;
1376 /* We choose to only get the type of the base object and
1377 * ignore potentially corrupt pack file that expects the delta
1378 * based on a base with a wrong size. This saves tons of
1379 * inflate() calls.
1381 if (sizep) {
1382 *sizep = get_size_from_delta(p, w_curs, curpos);
1383 if (*sizep == 0)
1384 type = OBJ_BAD;
1387 return type;
1390 static int unpack_object_header(struct packed_git *p,
1391 struct pack_window **w_curs,
1392 off_t *curpos,
1393 unsigned long *sizep)
1395 unsigned char *base;
1396 unsigned int left;
1397 unsigned long used;
1398 enum object_type type;
1400 /* use_pack() assures us we have [base, base + 20) available
1401 * as a range that we can look at at. (Its actually the hash
1402 * size that is assured.) With our object header encoding
1403 * the maximum deflated object size is 2^137, which is just
1404 * insane, so we know won't exceed what we have been given.
1406 base = use_pack(p, w_curs, *curpos, &left);
1407 used = unpack_object_header_buffer(base, left, &type, sizep);
1408 if (!used) {
1409 type = OBJ_BAD;
1410 } else
1411 *curpos += used;
1413 return type;
1416 const char *packed_object_info_detail(struct packed_git *p,
1417 off_t obj_offset,
1418 unsigned long *size,
1419 unsigned long *store_size,
1420 unsigned int *delta_chain_length,
1421 unsigned char *base_sha1)
1423 struct pack_window *w_curs = NULL;
1424 off_t curpos;
1425 unsigned long dummy;
1426 unsigned char *next_sha1;
1427 enum object_type type;
1428 struct revindex_entry *revidx;
1430 *delta_chain_length = 0;
1431 curpos = obj_offset;
1432 type = unpack_object_header(p, &w_curs, &curpos, size);
1434 revidx = find_pack_revindex(p, obj_offset);
1435 *store_size = revidx[1].offset - obj_offset;
1437 for (;;) {
1438 switch (type) {
1439 default:
1440 die("pack %s contains unknown object type %d",
1441 p->pack_name, type);
1442 case OBJ_COMMIT:
1443 case OBJ_TREE:
1444 case OBJ_BLOB:
1445 case OBJ_TAG:
1446 unuse_pack(&w_curs);
1447 return typename(type);
1448 case OBJ_OFS_DELTA:
1449 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1450 if (!obj_offset)
1451 die("pack %s contains bad delta base reference of type %s",
1452 p->pack_name, typename(type));
1453 if (*delta_chain_length == 0) {
1454 revidx = find_pack_revindex(p, obj_offset);
1455 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
1457 break;
1458 case OBJ_REF_DELTA:
1459 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1460 if (*delta_chain_length == 0)
1461 hashcpy(base_sha1, next_sha1);
1462 obj_offset = find_pack_entry_one(next_sha1, p);
1463 break;
1465 (*delta_chain_length)++;
1466 curpos = obj_offset;
1467 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1471 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1472 unsigned long *sizep)
1474 struct pack_window *w_curs = NULL;
1475 unsigned long size;
1476 off_t curpos = obj_offset;
1477 enum object_type type;
1479 type = unpack_object_header(p, &w_curs, &curpos, &size);
1481 switch (type) {
1482 case OBJ_OFS_DELTA:
1483 case OBJ_REF_DELTA:
1484 type = packed_delta_info(p, &w_curs, curpos,
1485 type, obj_offset, sizep);
1486 break;
1487 case OBJ_COMMIT:
1488 case OBJ_TREE:
1489 case OBJ_BLOB:
1490 case OBJ_TAG:
1491 if (sizep)
1492 *sizep = size;
1493 break;
1494 default:
1495 error("unknown object type %i at offset %"PRIuMAX" in %s",
1496 type, (uintmax_t)obj_offset, p->pack_name);
1497 type = OBJ_BAD;
1499 unuse_pack(&w_curs);
1500 return type;
1503 static void *unpack_compressed_entry(struct packed_git *p,
1504 struct pack_window **w_curs,
1505 off_t curpos,
1506 unsigned long size)
1508 int st;
1509 z_stream stream;
1510 unsigned char *buffer, *in;
1512 buffer = xmallocz(size);
1513 memset(&stream, 0, sizeof(stream));
1514 stream.next_out = buffer;
1515 stream.avail_out = size + 1;
1517 git_inflate_init(&stream);
1518 do {
1519 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1520 stream.next_in = in;
1521 st = git_inflate(&stream, Z_FINISH);
1522 if (!stream.avail_out)
1523 break; /* the payload is larger than it should be */
1524 curpos += stream.next_in - in;
1525 } while (st == Z_OK || st == Z_BUF_ERROR);
1526 git_inflate_end(&stream);
1527 if ((st != Z_STREAM_END) || stream.total_out != size) {
1528 free(buffer);
1529 return NULL;
1532 return buffer;
1535 #define MAX_DELTA_CACHE (256)
1537 static size_t delta_base_cached;
1539 static struct delta_base_cache_lru_list {
1540 struct delta_base_cache_lru_list *prev;
1541 struct delta_base_cache_lru_list *next;
1542 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1544 static struct delta_base_cache_entry {
1545 struct delta_base_cache_lru_list lru;
1546 void *data;
1547 struct packed_git *p;
1548 off_t base_offset;
1549 unsigned long size;
1550 enum object_type type;
1551 } delta_base_cache[MAX_DELTA_CACHE];
1553 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1555 unsigned long hash;
1557 hash = (unsigned long)p + (unsigned long)base_offset;
1558 hash += (hash >> 8) + (hash >> 16);
1559 return hash % MAX_DELTA_CACHE;
1562 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1563 unsigned long *base_size, enum object_type *type, int keep_cache)
1565 void *ret;
1566 unsigned long hash = pack_entry_hash(p, base_offset);
1567 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1569 ret = ent->data;
1570 if (!ret || ent->p != p || ent->base_offset != base_offset)
1571 return unpack_entry(p, base_offset, type, base_size);
1573 if (!keep_cache) {
1574 ent->data = NULL;
1575 ent->lru.next->prev = ent->lru.prev;
1576 ent->lru.prev->next = ent->lru.next;
1577 delta_base_cached -= ent->size;
1578 } else {
1579 ret = xmemdupz(ent->data, ent->size);
1581 *type = ent->type;
1582 *base_size = ent->size;
1583 return ret;
1586 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1588 if (ent->data) {
1589 free(ent->data);
1590 ent->data = NULL;
1591 ent->lru.next->prev = ent->lru.prev;
1592 ent->lru.prev->next = ent->lru.next;
1593 delta_base_cached -= ent->size;
1597 void clear_delta_base_cache(void)
1599 unsigned long p;
1600 for (p = 0; p < MAX_DELTA_CACHE; p++)
1601 release_delta_base_cache(&delta_base_cache[p]);
1604 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1605 void *base, unsigned long base_size, enum object_type type)
1607 unsigned long hash = pack_entry_hash(p, base_offset);
1608 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1609 struct delta_base_cache_lru_list *lru;
1611 release_delta_base_cache(ent);
1612 delta_base_cached += base_size;
1614 for (lru = delta_base_cache_lru.next;
1615 delta_base_cached > delta_base_cache_limit
1616 && lru != &delta_base_cache_lru;
1617 lru = lru->next) {
1618 struct delta_base_cache_entry *f = (void *)lru;
1619 if (f->type == OBJ_BLOB)
1620 release_delta_base_cache(f);
1622 for (lru = delta_base_cache_lru.next;
1623 delta_base_cached > delta_base_cache_limit
1624 && lru != &delta_base_cache_lru;
1625 lru = lru->next) {
1626 struct delta_base_cache_entry *f = (void *)lru;
1627 release_delta_base_cache(f);
1630 ent->p = p;
1631 ent->base_offset = base_offset;
1632 ent->type = type;
1633 ent->data = base;
1634 ent->size = base_size;
1635 ent->lru.next = &delta_base_cache_lru;
1636 ent->lru.prev = delta_base_cache_lru.prev;
1637 delta_base_cache_lru.prev->next = &ent->lru;
1638 delta_base_cache_lru.prev = &ent->lru;
1641 static void *read_object(const unsigned char *sha1, enum object_type *type,
1642 unsigned long *size);
1644 static void *unpack_delta_entry(struct packed_git *p,
1645 struct pack_window **w_curs,
1646 off_t curpos,
1647 unsigned long delta_size,
1648 off_t obj_offset,
1649 enum object_type *type,
1650 unsigned long *sizep)
1652 void *delta_data, *result, *base;
1653 unsigned long base_size;
1654 off_t base_offset;
1656 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1657 if (!base_offset) {
1658 error("failed to validate delta base reference "
1659 "at offset %"PRIuMAX" from %s",
1660 (uintmax_t)curpos, p->pack_name);
1661 return NULL;
1663 unuse_pack(w_curs);
1664 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1665 if (!base) {
1667 * We're probably in deep shit, but let's try to fetch
1668 * the required base anyway from another pack or loose.
1669 * This is costly but should happen only in the presence
1670 * of a corrupted pack, and is better than failing outright.
1672 struct revindex_entry *revidx;
1673 const unsigned char *base_sha1;
1674 revidx = find_pack_revindex(p, base_offset);
1675 if (!revidx)
1676 return NULL;
1677 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1678 error("failed to read delta base object %s"
1679 " at offset %"PRIuMAX" from %s",
1680 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1681 p->pack_name);
1682 mark_bad_packed_object(p, base_sha1);
1683 base = read_object(base_sha1, type, &base_size);
1684 if (!base)
1685 return NULL;
1688 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1689 if (!delta_data) {
1690 error("failed to unpack compressed delta "
1691 "at offset %"PRIuMAX" from %s",
1692 (uintmax_t)curpos, p->pack_name);
1693 free(base);
1694 return NULL;
1696 result = patch_delta(base, base_size,
1697 delta_data, delta_size,
1698 sizep);
1699 if (!result)
1700 die("failed to apply delta");
1701 free(delta_data);
1702 add_delta_base_cache(p, base_offset, base, base_size, *type);
1703 return result;
1706 int do_check_packed_object_crc;
1708 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1709 enum object_type *type, unsigned long *sizep)
1711 struct pack_window *w_curs = NULL;
1712 off_t curpos = obj_offset;
1713 void *data;
1715 if (do_check_packed_object_crc && p->index_version > 1) {
1716 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1717 unsigned long len = revidx[1].offset - obj_offset;
1718 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1719 const unsigned char *sha1 =
1720 nth_packed_object_sha1(p, revidx->nr);
1721 error("bad packed object CRC for %s",
1722 sha1_to_hex(sha1));
1723 mark_bad_packed_object(p, sha1);
1724 unuse_pack(&w_curs);
1725 return NULL;
1729 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1730 switch (*type) {
1731 case OBJ_OFS_DELTA:
1732 case OBJ_REF_DELTA:
1733 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1734 obj_offset, type, sizep);
1735 break;
1736 case OBJ_COMMIT:
1737 case OBJ_TREE:
1738 case OBJ_BLOB:
1739 case OBJ_TAG:
1740 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1741 break;
1742 default:
1743 data = NULL;
1744 error("unknown object type %i at offset %"PRIuMAX" in %s",
1745 *type, (uintmax_t)obj_offset, p->pack_name);
1747 unuse_pack(&w_curs);
1748 return data;
1751 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1752 uint32_t n)
1754 const unsigned char *index = p->index_data;
1755 if (!index) {
1756 if (open_pack_index(p))
1757 return NULL;
1758 index = p->index_data;
1760 if (n >= p->num_objects)
1761 return NULL;
1762 index += 4 * 256;
1763 if (p->index_version == 1) {
1764 return index + 24 * n + 4;
1765 } else {
1766 index += 8;
1767 return index + 20 * n;
1771 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1773 const unsigned char *index = p->index_data;
1774 index += 4 * 256;
1775 if (p->index_version == 1) {
1776 return ntohl(*((uint32_t *)(index + 24 * n)));
1777 } else {
1778 uint32_t off;
1779 index += 8 + p->num_objects * (20 + 4);
1780 off = ntohl(*((uint32_t *)(index + 4 * n)));
1781 if (!(off & 0x80000000))
1782 return off;
1783 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1784 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1785 ntohl(*((uint32_t *)(index + 4)));
1789 off_t find_pack_entry_one(const unsigned char *sha1,
1790 struct packed_git *p)
1792 const uint32_t *level1_ofs = p->index_data;
1793 const unsigned char *index = p->index_data;
1794 unsigned hi, lo, stride;
1795 static int use_lookup = -1;
1796 static int debug_lookup = -1;
1798 if (debug_lookup < 0)
1799 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
1801 if (!index) {
1802 if (open_pack_index(p))
1803 return 0;
1804 level1_ofs = p->index_data;
1805 index = p->index_data;
1807 if (p->index_version > 1) {
1808 level1_ofs += 2;
1809 index += 8;
1811 index += 4 * 256;
1812 hi = ntohl(level1_ofs[*sha1]);
1813 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1814 if (p->index_version > 1) {
1815 stride = 20;
1816 } else {
1817 stride = 24;
1818 index += 4;
1821 if (debug_lookup)
1822 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
1823 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1825 if (use_lookup < 0)
1826 use_lookup = !!getenv("GIT_USE_LOOKUP");
1827 if (use_lookup) {
1828 int pos = sha1_entry_pos(index, stride, 0,
1829 lo, hi, p->num_objects, sha1);
1830 if (pos < 0)
1831 return 0;
1832 return nth_packed_object_offset(p, pos);
1835 do {
1836 unsigned mi = (lo + hi) / 2;
1837 int cmp = hashcmp(index + mi * stride, sha1);
1839 if (debug_lookup)
1840 printf("lo %u hi %u rg %u mi %u\n",
1841 lo, hi, hi - lo, mi);
1842 if (!cmp)
1843 return nth_packed_object_offset(p, mi);
1844 if (cmp > 0)
1845 hi = mi;
1846 else
1847 lo = mi+1;
1848 } while (lo < hi);
1849 return 0;
1852 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1854 static struct packed_git *last_found = (void *)1;
1855 struct packed_git *p;
1856 off_t offset;
1858 prepare_packed_git();
1859 if (!packed_git)
1860 return 0;
1861 p = (last_found == (void *)1) ? packed_git : last_found;
1863 do {
1864 if (p->num_bad_objects) {
1865 unsigned i;
1866 for (i = 0; i < p->num_bad_objects; i++)
1867 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1868 goto next;
1871 offset = find_pack_entry_one(sha1, p);
1872 if (offset) {
1874 * We are about to tell the caller where they can
1875 * locate the requested object. We better make
1876 * sure the packfile is still here and can be
1877 * accessed before supplying that answer, as
1878 * it may have been deleted since the index
1879 * was loaded!
1881 if (p->pack_fd == -1 && open_packed_git(p)) {
1882 error("packfile %s cannot be accessed", p->pack_name);
1883 goto next;
1885 e->offset = offset;
1886 e->p = p;
1887 hashcpy(e->sha1, sha1);
1888 last_found = p;
1889 return 1;
1892 next:
1893 if (p == last_found)
1894 p = packed_git;
1895 else
1896 p = p->next;
1897 if (p == last_found)
1898 p = p->next;
1899 } while (p);
1900 return 0;
1903 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1904 struct packed_git *packs)
1906 struct packed_git *p;
1908 for (p = packs; p; p = p->next) {
1909 if (find_pack_entry_one(sha1, p))
1910 return p;
1912 return NULL;
1916 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1918 int status;
1919 unsigned long mapsize, size;
1920 void *map;
1921 z_stream stream;
1922 char hdr[32];
1924 map = map_sha1_file(sha1, &mapsize);
1925 if (!map)
1926 return error("unable to find %s", sha1_to_hex(sha1));
1927 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1928 status = error("unable to unpack %s header",
1929 sha1_to_hex(sha1));
1930 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1931 status = error("unable to parse %s header", sha1_to_hex(sha1));
1932 else if (sizep)
1933 *sizep = size;
1934 git_inflate_end(&stream);
1935 munmap(map, mapsize);
1936 return status;
1939 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1941 struct pack_entry e;
1942 int status;
1944 if (!find_pack_entry(sha1, &e)) {
1945 /* Most likely it's a loose object. */
1946 status = sha1_loose_object_info(sha1, sizep);
1947 if (status >= 0)
1948 return status;
1950 /* Not a loose object; someone else may have just packed it. */
1951 reprepare_packed_git();
1952 if (!find_pack_entry(sha1, &e))
1953 return status;
1956 status = packed_object_info(e.p, e.offset, sizep);
1957 if (status < 0) {
1958 mark_bad_packed_object(e.p, sha1);
1959 status = sha1_object_info(sha1, sizep);
1962 return status;
1965 static void *read_packed_sha1(const unsigned char *sha1,
1966 enum object_type *type, unsigned long *size)
1968 struct pack_entry e;
1969 void *data;
1971 if (!find_pack_entry(sha1, &e))
1972 return NULL;
1973 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1974 if (!data) {
1976 * We're probably in deep shit, but let's try to fetch
1977 * the required object anyway from another pack or loose.
1978 * This should happen only in the presence of a corrupted
1979 * pack, and is better than failing outright.
1981 error("failed to read object %s at offset %"PRIuMAX" from %s",
1982 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1983 mark_bad_packed_object(e.p, sha1);
1984 data = read_object(sha1, type, size);
1986 return data;
1990 * This is meant to hold a *small* number of objects that you would
1991 * want read_sha1_file() to be able to return, but yet you do not want
1992 * to write them into the object store (e.g. a browse-only
1993 * application).
1995 static struct cached_object {
1996 unsigned char sha1[20];
1997 enum object_type type;
1998 void *buf;
1999 unsigned long size;
2000 } *cached_objects;
2001 static int cached_object_nr, cached_object_alloc;
2003 static struct cached_object empty_tree = {
2004 EMPTY_TREE_SHA1_BIN,
2005 OBJ_TREE,
2010 static struct cached_object *find_cached_object(const unsigned char *sha1)
2012 int i;
2013 struct cached_object *co = cached_objects;
2015 for (i = 0; i < cached_object_nr; i++, co++) {
2016 if (!hashcmp(co->sha1, sha1))
2017 return co;
2019 if (!hashcmp(sha1, empty_tree.sha1))
2020 return &empty_tree;
2021 return NULL;
2024 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2025 unsigned char *sha1)
2027 struct cached_object *co;
2029 hash_sha1_file(buf, len, typename(type), sha1);
2030 if (has_sha1_file(sha1) || find_cached_object(sha1))
2031 return 0;
2032 if (cached_object_alloc <= cached_object_nr) {
2033 cached_object_alloc = alloc_nr(cached_object_alloc);
2034 cached_objects = xrealloc(cached_objects,
2035 sizeof(*cached_objects) *
2036 cached_object_alloc);
2038 co = &cached_objects[cached_object_nr++];
2039 co->size = len;
2040 co->type = type;
2041 co->buf = xmalloc(len);
2042 memcpy(co->buf, buf, len);
2043 hashcpy(co->sha1, sha1);
2044 return 0;
2047 static void *read_object(const unsigned char *sha1, enum object_type *type,
2048 unsigned long *size)
2050 unsigned long mapsize;
2051 void *map, *buf;
2052 struct cached_object *co;
2054 co = find_cached_object(sha1);
2055 if (co) {
2056 *type = co->type;
2057 *size = co->size;
2058 return xmemdupz(co->buf, co->size);
2061 buf = read_packed_sha1(sha1, type, size);
2062 if (buf)
2063 return buf;
2064 map = map_sha1_file(sha1, &mapsize);
2065 if (map) {
2066 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2067 munmap(map, mapsize);
2068 return buf;
2070 reprepare_packed_git();
2071 return read_packed_sha1(sha1, type, size);
2074 void *read_sha1_file_repl(const unsigned char *sha1,
2075 enum object_type *type,
2076 unsigned long *size,
2077 const unsigned char **replacement)
2079 const unsigned char *repl = lookup_replace_object(sha1);
2080 void *data = read_object(repl, type, size);
2082 /* die if we replaced an object with one that does not exist */
2083 if (!data && repl != sha1)
2084 die("replacement %s not found for %s",
2085 sha1_to_hex(repl), sha1_to_hex(sha1));
2087 /* legacy behavior is to die on corrupted objects */
2088 if (!data && (has_loose_object(repl) || has_packed_and_bad(repl)))
2089 die("object %s is corrupted", sha1_to_hex(repl));
2091 if (replacement)
2092 *replacement = repl;
2094 return data;
2097 void *read_object_with_reference(const unsigned char *sha1,
2098 const char *required_type_name,
2099 unsigned long *size,
2100 unsigned char *actual_sha1_return)
2102 enum object_type type, required_type;
2103 void *buffer;
2104 unsigned long isize;
2105 unsigned char actual_sha1[20];
2107 required_type = type_from_string(required_type_name);
2108 hashcpy(actual_sha1, sha1);
2109 while (1) {
2110 int ref_length = -1;
2111 const char *ref_type = NULL;
2113 buffer = read_sha1_file(actual_sha1, &type, &isize);
2114 if (!buffer)
2115 return NULL;
2116 if (type == required_type) {
2117 *size = isize;
2118 if (actual_sha1_return)
2119 hashcpy(actual_sha1_return, actual_sha1);
2120 return buffer;
2122 /* Handle references */
2123 else if (type == OBJ_COMMIT)
2124 ref_type = "tree ";
2125 else if (type == OBJ_TAG)
2126 ref_type = "object ";
2127 else {
2128 free(buffer);
2129 return NULL;
2131 ref_length = strlen(ref_type);
2133 if (ref_length + 40 > isize ||
2134 memcmp(buffer, ref_type, ref_length) ||
2135 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2136 free(buffer);
2137 return NULL;
2139 free(buffer);
2140 /* Now we have the ID of the referred-to object in
2141 * actual_sha1. Check again. */
2145 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2146 const char *type, unsigned char *sha1,
2147 char *hdr, int *hdrlen)
2149 git_SHA_CTX c;
2151 /* Generate the header */
2152 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2154 /* Sha1.. */
2155 git_SHA1_Init(&c);
2156 git_SHA1_Update(&c, hdr, *hdrlen);
2157 git_SHA1_Update(&c, buf, len);
2158 git_SHA1_Final(sha1, &c);
2162 * Move the just written object into its final resting place.
2163 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2164 * "moving" is only a part of what it does, when no patch between
2165 * master to pu changes the call sites of this function.
2167 int move_temp_to_file(const char *tmpfile, const char *filename)
2169 int ret = 0;
2171 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2172 goto try_rename;
2173 else if (link(tmpfile, filename))
2174 ret = errno;
2177 * Coda hack - coda doesn't like cross-directory links,
2178 * so we fall back to a rename, which will mean that it
2179 * won't be able to check collisions, but that's not a
2180 * big deal.
2182 * The same holds for FAT formatted media.
2184 * When this succeeds, we just return. We have nothing
2185 * left to unlink.
2187 if (ret && ret != EEXIST) {
2188 try_rename:
2189 if (!rename(tmpfile, filename))
2190 goto out;
2191 ret = errno;
2193 unlink_or_warn(tmpfile);
2194 if (ret) {
2195 if (ret != EEXIST) {
2196 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
2198 /* FIXME!!! Collision check here ? */
2201 out:
2202 if (adjust_shared_perm(filename))
2203 return error("unable to set permission to '%s'", filename);
2204 return 0;
2207 static int write_buffer(int fd, const void *buf, size_t len)
2209 if (write_in_full(fd, buf, len) < 0)
2210 return error("file write error (%s)", strerror(errno));
2211 return 0;
2214 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2215 unsigned char *sha1)
2217 char hdr[32];
2218 int hdrlen;
2219 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2220 return 0;
2223 /* Finalize a file on disk, and close it. */
2224 static void close_sha1_file(int fd)
2226 if (fsync_object_files)
2227 fsync_or_die(fd, "sha1 file");
2228 if (close(fd) != 0)
2229 die_errno("error when closing sha1 file");
2232 /* Size of directory component, including the ending '/' */
2233 static inline int directory_size(const char *filename)
2235 const char *s = strrchr(filename, '/');
2236 if (!s)
2237 return 0;
2238 return s - filename + 1;
2242 * This creates a temporary file in the same directory as the final
2243 * 'filename'
2245 * We want to avoid cross-directory filename renames, because those
2246 * can have problems on various filesystems (FAT, NFS, Coda).
2248 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2250 int fd, dirlen = directory_size(filename);
2252 if (dirlen + 20 > bufsiz) {
2253 errno = ENAMETOOLONG;
2254 return -1;
2256 memcpy(buffer, filename, dirlen);
2257 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2258 fd = git_mkstemp_mode(buffer, 0444);
2259 if (fd < 0 && dirlen && errno == ENOENT) {
2260 /* Make sure the directory exists */
2261 memcpy(buffer, filename, dirlen);
2262 buffer[dirlen-1] = 0;
2263 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2264 return -1;
2266 /* Try again */
2267 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2268 fd = git_mkstemp_mode(buffer, 0444);
2270 return fd;
2273 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2274 const void *buf, unsigned long len, time_t mtime)
2276 int fd, ret;
2277 unsigned char compressed[4096];
2278 z_stream stream;
2279 git_SHA_CTX c;
2280 unsigned char parano_sha1[20];
2281 char *filename;
2282 static char tmpfile[PATH_MAX];
2284 filename = sha1_file_name(sha1);
2285 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2286 while (fd < 0 && errno == EMFILE && unuse_one_window(packed_git, -1))
2287 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2288 if (fd < 0) {
2289 if (errno == EACCES)
2290 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2291 else
2292 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2295 /* Set it up */
2296 memset(&stream, 0, sizeof(stream));
2297 deflateInit(&stream, zlib_compression_level);
2298 stream.next_out = compressed;
2299 stream.avail_out = sizeof(compressed);
2300 git_SHA1_Init(&c);
2302 /* First header.. */
2303 stream.next_in = (unsigned char *)hdr;
2304 stream.avail_in = hdrlen;
2305 while (deflate(&stream, 0) == Z_OK)
2306 /* nothing */;
2307 git_SHA1_Update(&c, hdr, hdrlen);
2309 /* Then the data itself.. */
2310 stream.next_in = (void *)buf;
2311 stream.avail_in = len;
2312 do {
2313 unsigned char *in0 = stream.next_in;
2314 ret = deflate(&stream, Z_FINISH);
2315 git_SHA1_Update(&c, in0, stream.next_in - in0);
2316 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2317 die("unable to write sha1 file");
2318 stream.next_out = compressed;
2319 stream.avail_out = sizeof(compressed);
2320 } while (ret == Z_OK);
2322 if (ret != Z_STREAM_END)
2323 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2324 ret = deflateEnd(&stream);
2325 if (ret != Z_OK)
2326 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2327 git_SHA1_Final(parano_sha1, &c);
2328 if (hashcmp(sha1, parano_sha1) != 0)
2329 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
2331 close_sha1_file(fd);
2333 if (mtime) {
2334 struct utimbuf utb;
2335 utb.actime = mtime;
2336 utb.modtime = mtime;
2337 if (utime(tmpfile, &utb) < 0)
2338 warning("failed utime() on %s: %s",
2339 tmpfile, strerror(errno));
2342 return move_temp_to_file(tmpfile, filename);
2345 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2347 unsigned char sha1[20];
2348 char hdr[32];
2349 int hdrlen;
2351 /* Normally if we have it in the pack then we do not bother writing
2352 * it out into .git/objects/??/?{38} file.
2354 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2355 if (returnsha1)
2356 hashcpy(returnsha1, sha1);
2357 if (has_sha1_file(sha1))
2358 return 0;
2359 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2362 int force_object_loose(const unsigned char *sha1, time_t mtime)
2364 void *buf;
2365 unsigned long len;
2366 enum object_type type;
2367 char hdr[32];
2368 int hdrlen;
2369 int ret;
2371 if (has_loose_object(sha1))
2372 return 0;
2373 buf = read_packed_sha1(sha1, &type, &len);
2374 if (!buf)
2375 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2376 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2377 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2378 free(buf);
2380 return ret;
2383 int has_pack_index(const unsigned char *sha1)
2385 struct stat st;
2386 if (stat(sha1_pack_index_name(sha1), &st))
2387 return 0;
2388 return 1;
2391 int has_sha1_pack(const unsigned char *sha1)
2393 struct pack_entry e;
2394 return find_pack_entry(sha1, &e);
2397 int has_sha1_file(const unsigned char *sha1)
2399 struct pack_entry e;
2401 if (find_pack_entry(sha1, &e))
2402 return 1;
2403 return has_loose_object(sha1);
2406 static int index_mem(unsigned char *sha1, void *buf, size_t size,
2407 int write_object, enum object_type type, const char *path)
2409 int ret, re_allocated = 0;
2411 if (!type)
2412 type = OBJ_BLOB;
2415 * Convert blobs to git internal format
2417 if ((type == OBJ_BLOB) && path) {
2418 struct strbuf nbuf = STRBUF_INIT;
2419 if (convert_to_git(path, buf, size, &nbuf,
2420 write_object ? safe_crlf : 0)) {
2421 buf = strbuf_detach(&nbuf, &size);
2422 re_allocated = 1;
2426 if (write_object)
2427 ret = write_sha1_file(buf, size, typename(type), sha1);
2428 else
2429 ret = hash_sha1_file(buf, size, typename(type), sha1);
2430 if (re_allocated)
2431 free(buf);
2432 return ret;
2435 #define SMALL_FILE_SIZE (32*1024)
2437 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2438 enum object_type type, const char *path)
2440 int ret;
2441 size_t size = xsize_t(st->st_size);
2443 if (!S_ISREG(st->st_mode)) {
2444 struct strbuf sbuf = STRBUF_INIT;
2445 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2446 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2447 type, path);
2448 else
2449 ret = -1;
2450 strbuf_release(&sbuf);
2451 } else if (size <= SMALL_FILE_SIZE) {
2452 char *buf = xmalloc(size);
2453 if (size == read_in_full(fd, buf, size))
2454 ret = index_mem(sha1, buf, size, write_object, type,
2455 path);
2456 else
2457 ret = error("short read %s", strerror(errno));
2458 free(buf);
2459 } else if (size) {
2460 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2461 ret = index_mem(sha1, buf, size, write_object, type, path);
2462 munmap(buf, size);
2463 } else
2464 ret = index_mem(sha1, NULL, size, write_object, type, path);
2465 close(fd);
2466 return ret;
2469 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2471 int fd;
2472 struct strbuf sb = STRBUF_INIT;
2474 switch (st->st_mode & S_IFMT) {
2475 case S_IFREG:
2476 fd = open(path, O_RDONLY);
2477 if (fd < 0)
2478 return error("open(\"%s\"): %s", path,
2479 strerror(errno));
2480 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2481 return error("%s: failed to insert into database",
2482 path);
2483 break;
2484 case S_IFLNK:
2485 if (strbuf_readlink(&sb, path, st->st_size)) {
2486 char *errstr = strerror(errno);
2487 return error("readlink(\"%s\"): %s", path,
2488 errstr);
2490 if (!write_object)
2491 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2492 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
2493 return error("%s: failed to insert into database",
2494 path);
2495 strbuf_release(&sb);
2496 break;
2497 case S_IFDIR:
2498 return resolve_gitlink_ref(path, "HEAD", sha1);
2499 default:
2500 return error("%s: unsupported file type", path);
2502 return 0;
2505 int read_pack_header(int fd, struct pack_header *header)
2507 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2508 /* "eof before pack header was fully read" */
2509 return PH_ERROR_EOF;
2511 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2512 /* "protocol error (pack signature mismatch detected)" */
2513 return PH_ERROR_PACK_SIGNATURE;
2514 if (!pack_version_ok(header->hdr_version))
2515 /* "protocol error (pack version unsupported)" */
2516 return PH_ERROR_PROTOCOL;
2517 return 0;
2520 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
2522 enum object_type type = sha1_object_info(sha1, NULL);
2523 if (type < 0)
2524 die("%s is not a valid object", sha1_to_hex(sha1));
2525 if (type != expect)
2526 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
2527 typename(expect));