gitweb: Create Gitweb::Util module
[git/jnareb-git/bp-gitweb.git] / sha1_file.c
blobd86a8db69ade6fd26ebd88bbb361a7a86838f14e
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 static int git_open_noatime(const char *name, struct packed_git *p);
40 int safe_create_leading_directories(char *path)
42 char *pos = path + offset_1st_component(path);
43 struct stat st;
45 while (pos) {
46 pos = strchr(pos, '/');
47 if (!pos)
48 break;
49 while (*++pos == '/')
51 if (!*pos)
52 break;
53 *--pos = '\0';
54 if (!stat(path, &st)) {
55 /* path exists */
56 if (!S_ISDIR(st.st_mode)) {
57 *pos = '/';
58 return -3;
61 else if (mkdir(path, 0777)) {
62 *pos = '/';
63 return -1;
65 else if (adjust_shared_perm(path)) {
66 *pos = '/';
67 return -2;
69 *pos++ = '/';
71 return 0;
74 int safe_create_leading_directories_const(const char *path)
76 /* path points to cache entries, so xstrdup before messing with it */
77 char *buf = xstrdup(path);
78 int result = safe_create_leading_directories(buf);
79 free(buf);
80 return result;
83 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
85 int i;
86 for (i = 0; i < 20; i++) {
87 static char hex[] = "0123456789abcdef";
88 unsigned int val = sha1[i];
89 char *pos = pathbuf + i*2 + (i > 0);
90 *pos++ = hex[val >> 4];
91 *pos = hex[val & 0xf];
96 * NOTE! This returns a statically allocated buffer, so you have to be
97 * careful about using it. Do an "xstrdup()" if you need to save the
98 * filename.
100 * Also note that this returns the location for creating. Reading
101 * SHA1 file can happen from any alternate directory listed in the
102 * DB_ENVIRONMENT environment variable if it is not found in
103 * the primary object database.
105 char *sha1_file_name(const unsigned char *sha1)
107 static char buf[PATH_MAX];
108 const char *objdir;
109 int len;
111 objdir = get_object_directory();
112 len = strlen(objdir);
114 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
115 if (len + 43 > PATH_MAX)
116 die("insanely long object directory %s", objdir);
117 memcpy(buf, objdir, len);
118 buf[len] = '/';
119 buf[len+3] = '/';
120 buf[len+42] = '\0';
121 fill_sha1_path(buf + len + 1, sha1);
122 return buf;
125 static char *sha1_get_pack_name(const unsigned char *sha1,
126 char **name, char **base, const char *which)
128 static const char hex[] = "0123456789abcdef";
129 char *buf;
130 int i;
132 if (!*base) {
133 const char *sha1_file_directory = get_object_directory();
134 int len = strlen(sha1_file_directory);
135 *base = xmalloc(len + 60);
136 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
137 sha1_file_directory, which);
138 *name = *base + len + 11;
141 buf = *name;
143 for (i = 0; i < 20; i++) {
144 unsigned int val = *sha1++;
145 *buf++ = hex[val >> 4];
146 *buf++ = hex[val & 0xf];
149 return *base;
152 char *sha1_pack_name(const unsigned char *sha1)
154 static char *name, *base;
156 return sha1_get_pack_name(sha1, &name, &base, "pack");
159 char *sha1_pack_index_name(const unsigned char *sha1)
161 static char *name, *base;
163 return sha1_get_pack_name(sha1, &name, &base, "idx");
166 struct alternate_object_database *alt_odb_list;
167 static struct alternate_object_database **alt_odb_tail;
169 static void read_info_alternates(const char * alternates, int depth);
172 * Prepare alternate object database registry.
174 * The variable alt_odb_list points at the list of struct
175 * alternate_object_database. The elements on this list come from
176 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
177 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
178 * whose contents is similar to that environment variable but can be
179 * LF separated. Its base points at a statically allocated buffer that
180 * contains "/the/directory/corresponding/to/.git/objects/...", while
181 * its name points just after the slash at the end of ".git/objects/"
182 * in the example above, and has enough space to hold 40-byte hex
183 * SHA1, an extra slash for the first level indirection, and the
184 * terminating NUL.
186 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
188 const char *objdir = get_object_directory();
189 struct alternate_object_database *ent;
190 struct alternate_object_database *alt;
191 /* 43 = 40-byte + 2 '/' + terminating NUL */
192 int pfxlen = len;
193 int entlen = pfxlen + 43;
194 int base_len = -1;
196 if (!is_absolute_path(entry) && relative_base) {
197 /* Relative alt-odb */
198 if (base_len < 0)
199 base_len = strlen(relative_base) + 1;
200 entlen += base_len;
201 pfxlen += base_len;
203 ent = xmalloc(sizeof(*ent) + entlen);
205 if (!is_absolute_path(entry) && relative_base) {
206 memcpy(ent->base, relative_base, base_len - 1);
207 ent->base[base_len - 1] = '/';
208 memcpy(ent->base + base_len, entry, len);
210 else
211 memcpy(ent->base, entry, pfxlen);
213 ent->name = ent->base + pfxlen + 1;
214 ent->base[pfxlen + 3] = '/';
215 ent->base[pfxlen] = ent->base[entlen-1] = 0;
217 /* Detect cases where alternate disappeared */
218 if (!is_directory(ent->base)) {
219 error("object directory %s does not exist; "
220 "check .git/objects/info/alternates.",
221 ent->base);
222 free(ent);
223 return -1;
226 /* Prevent the common mistake of listing the same
227 * thing twice, or object directory itself.
229 for (alt = alt_odb_list; alt; alt = alt->next) {
230 if (!memcmp(ent->base, alt->base, pfxlen)) {
231 free(ent);
232 return -1;
235 if (!memcmp(ent->base, objdir, pfxlen)) {
236 free(ent);
237 return -1;
240 /* add the alternate entry */
241 *alt_odb_tail = ent;
242 alt_odb_tail = &(ent->next);
243 ent->next = NULL;
245 /* recursively add alternates */
246 read_info_alternates(ent->base, depth + 1);
248 ent->base[pfxlen] = '/';
250 return 0;
253 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
254 const char *relative_base, int depth)
256 const char *cp, *last;
258 if (depth > 5) {
259 error("%s: ignoring alternate object stores, nesting too deep.",
260 relative_base);
261 return;
264 last = alt;
265 while (last < ep) {
266 cp = last;
267 if (cp < ep && *cp == '#') {
268 while (cp < ep && *cp != sep)
269 cp++;
270 last = cp + 1;
271 continue;
273 while (cp < ep && *cp != sep)
274 cp++;
275 if (last != cp) {
276 if (!is_absolute_path(last) && depth) {
277 error("%s: ignoring relative alternate object store %s",
278 relative_base, last);
279 } else {
280 link_alt_odb_entry(last, cp - last,
281 relative_base, depth);
284 while (cp < ep && *cp == sep)
285 cp++;
286 last = cp;
290 static void read_info_alternates(const char * relative_base, int depth)
292 char *map;
293 size_t mapsz;
294 struct stat st;
295 const char alt_file_name[] = "info/alternates";
296 /* Given that relative_base is no longer than PATH_MAX,
297 ensure that "path" has enough space to append "/", the
298 file name, "info/alternates", and a trailing NUL. */
299 char path[PATH_MAX + 1 + sizeof alt_file_name];
300 int fd;
302 sprintf(path, "%s/%s", relative_base, alt_file_name);
303 fd = git_open_noatime(path, NULL);
304 if (fd < 0)
305 return;
306 if (fstat(fd, &st) || (st.st_size == 0)) {
307 close(fd);
308 return;
310 mapsz = xsize_t(st.st_size);
311 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
312 close(fd);
314 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
316 munmap(map, mapsz);
319 void add_to_alternates_file(const char *reference)
321 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
322 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
323 char *alt = mkpath("%s/objects\n", reference);
324 write_or_die(fd, alt, strlen(alt));
325 if (commit_lock_file(lock))
326 die("could not close alternates file");
327 if (alt_odb_tail)
328 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
331 void foreach_alt_odb(alt_odb_fn fn, void *cb)
333 struct alternate_object_database *ent;
335 prepare_alt_odb();
336 for (ent = alt_odb_list; ent; ent = ent->next)
337 if (fn(ent, cb))
338 return;
341 void prepare_alt_odb(void)
343 const char *alt;
345 if (alt_odb_tail)
346 return;
348 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
349 if (!alt) alt = "";
351 alt_odb_tail = &alt_odb_list;
352 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
354 read_info_alternates(get_object_directory(), 0);
357 static int has_loose_object_local(const unsigned char *sha1)
359 char *name = sha1_file_name(sha1);
360 return !access(name, F_OK);
363 int has_loose_object_nonlocal(const unsigned char *sha1)
365 struct alternate_object_database *alt;
366 prepare_alt_odb();
367 for (alt = alt_odb_list; alt; alt = alt->next) {
368 fill_sha1_path(alt->name, sha1);
369 if (!access(alt->base, F_OK))
370 return 1;
372 return 0;
375 static int has_loose_object(const unsigned char *sha1)
377 return has_loose_object_local(sha1) ||
378 has_loose_object_nonlocal(sha1);
381 static unsigned int pack_used_ctr;
382 static unsigned int pack_mmap_calls;
383 static unsigned int peak_pack_open_windows;
384 static unsigned int pack_open_windows;
385 static size_t peak_pack_mapped;
386 static size_t pack_mapped;
387 struct packed_git *packed_git;
389 void pack_report(void)
391 fprintf(stderr,
392 "pack_report: getpagesize() = %10" SZ_FMT "\n"
393 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
394 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
395 sz_fmt(getpagesize()),
396 sz_fmt(packed_git_window_size),
397 sz_fmt(packed_git_limit));
398 fprintf(stderr,
399 "pack_report: pack_used_ctr = %10u\n"
400 "pack_report: pack_mmap_calls = %10u\n"
401 "pack_report: pack_open_windows = %10u / %10u\n"
402 "pack_report: pack_mapped = "
403 "%10" SZ_FMT " / %10" SZ_FMT "\n",
404 pack_used_ctr,
405 pack_mmap_calls,
406 pack_open_windows, peak_pack_open_windows,
407 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
410 static int check_packed_git_idx(const char *path, struct packed_git *p)
412 void *idx_map;
413 struct pack_idx_header *hdr;
414 size_t idx_size;
415 uint32_t version, nr, i, *index;
416 int fd = git_open_noatime(path, p);
417 struct stat st;
419 if (fd < 0)
420 return -1;
421 if (fstat(fd, &st)) {
422 close(fd);
423 return -1;
425 idx_size = xsize_t(st.st_size);
426 if (idx_size < 4 * 256 + 20 + 20) {
427 close(fd);
428 return error("index file %s is too small", path);
430 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
431 close(fd);
433 hdr = idx_map;
434 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
435 version = ntohl(hdr->idx_version);
436 if (version < 2 || version > 2) {
437 munmap(idx_map, idx_size);
438 return error("index file %s is version %"PRIu32
439 " and is not supported by this binary"
440 " (try upgrading GIT to a newer version)",
441 path, version);
443 } else
444 version = 1;
446 nr = 0;
447 index = idx_map;
448 if (version > 1)
449 index += 2; /* skip index header */
450 for (i = 0; i < 256; i++) {
451 uint32_t n = ntohl(index[i]);
452 if (n < nr) {
453 munmap(idx_map, idx_size);
454 return error("non-monotonic index %s", path);
456 nr = n;
459 if (version == 1) {
461 * Total size:
462 * - 256 index entries 4 bytes each
463 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
464 * - 20-byte SHA1 of the packfile
465 * - 20-byte SHA1 file checksum
467 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
468 munmap(idx_map, idx_size);
469 return error("wrong index v1 file size in %s", path);
471 } else if (version == 2) {
473 * Minimum size:
474 * - 8 bytes of header
475 * - 256 index entries 4 bytes each
476 * - 20-byte sha1 entry * nr
477 * - 4-byte crc entry * nr
478 * - 4-byte offset entry * nr
479 * - 20-byte SHA1 of the packfile
480 * - 20-byte SHA1 file checksum
481 * And after the 4-byte offset table might be a
482 * variable sized table containing 8-byte entries
483 * for offsets larger than 2^31.
485 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
486 unsigned long max_size = min_size;
487 if (nr)
488 max_size += (nr - 1)*8;
489 if (idx_size < min_size || idx_size > max_size) {
490 munmap(idx_map, idx_size);
491 return error("wrong index v2 file size in %s", path);
493 if (idx_size != min_size &&
495 * make sure we can deal with large pack offsets.
496 * 31-bit signed offset won't be enough, neither
497 * 32-bit unsigned one will be.
499 (sizeof(off_t) <= 4)) {
500 munmap(idx_map, idx_size);
501 return error("pack too large for current definition of off_t in %s", path);
505 p->index_version = version;
506 p->index_data = idx_map;
507 p->index_size = idx_size;
508 p->num_objects = nr;
509 return 0;
512 int open_pack_index(struct packed_git *p)
514 char *idx_name;
515 int ret;
517 if (p->index_data)
518 return 0;
520 idx_name = xstrdup(p->pack_name);
521 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
522 ret = check_packed_git_idx(idx_name, p);
523 free(idx_name);
524 return ret;
527 static void scan_windows(struct packed_git *p,
528 struct packed_git **lru_p,
529 struct pack_window **lru_w,
530 struct pack_window **lru_l)
532 struct pack_window *w, *w_l;
534 for (w_l = NULL, w = p->windows; w; w = w->next) {
535 if (!w->inuse_cnt) {
536 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
537 *lru_p = p;
538 *lru_w = w;
539 *lru_l = w_l;
542 w_l = w;
546 static int unuse_one_window(struct packed_git *current, int keep_fd)
548 struct packed_git *p, *lru_p = NULL;
549 struct pack_window *lru_w = NULL, *lru_l = NULL;
551 if (current)
552 scan_windows(current, &lru_p, &lru_w, &lru_l);
553 for (p = packed_git; p; p = p->next)
554 scan_windows(p, &lru_p, &lru_w, &lru_l);
555 if (lru_p) {
556 munmap(lru_w->base, lru_w->len);
557 pack_mapped -= lru_w->len;
558 if (lru_l)
559 lru_l->next = lru_w->next;
560 else {
561 lru_p->windows = lru_w->next;
562 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
563 close(lru_p->pack_fd);
564 lru_p->pack_fd = -1;
567 free(lru_w);
568 pack_open_windows--;
569 return 1;
571 return 0;
574 void release_pack_memory(size_t need, int fd)
576 size_t cur = pack_mapped;
577 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
578 ; /* nothing */
581 void *xmmap(void *start, size_t length,
582 int prot, int flags, int fd, off_t offset)
584 void *ret = mmap(start, length, prot, flags, fd, offset);
585 if (ret == MAP_FAILED) {
586 if (!length)
587 return NULL;
588 release_pack_memory(length, fd);
589 ret = mmap(start, length, prot, flags, fd, offset);
590 if (ret == MAP_FAILED)
591 die_errno("Out of memory? mmap failed");
593 return ret;
596 void close_pack_windows(struct packed_git *p)
598 while (p->windows) {
599 struct pack_window *w = p->windows;
601 if (w->inuse_cnt)
602 die("pack '%s' still has open windows to it",
603 p->pack_name);
604 munmap(w->base, w->len);
605 pack_mapped -= w->len;
606 pack_open_windows--;
607 p->windows = w->next;
608 free(w);
612 void unuse_pack(struct pack_window **w_cursor)
614 struct pack_window *w = *w_cursor;
615 if (w) {
616 w->inuse_cnt--;
617 *w_cursor = NULL;
621 void close_pack_index(struct packed_git *p)
623 if (p->index_data) {
624 munmap((void *)p->index_data, p->index_size);
625 p->index_data = NULL;
630 * This is used by git-repack in case a newly created pack happens to
631 * contain the same set of objects as an existing one. In that case
632 * the resulting file might be different even if its name would be the
633 * same. It is best to close any reference to the old pack before it is
634 * replaced on disk. Of course no index pointers nor windows for given pack
635 * must subsist at this point. If ever objects from this pack are requested
636 * again, the new version of the pack will be reinitialized through
637 * reprepare_packed_git().
639 void free_pack_by_name(const char *pack_name)
641 struct packed_git *p, **pp = &packed_git;
643 while (*pp) {
644 p = *pp;
645 if (strcmp(pack_name, p->pack_name) == 0) {
646 clear_delta_base_cache();
647 close_pack_windows(p);
648 if (p->pack_fd != -1)
649 close(p->pack_fd);
650 close_pack_index(p);
651 free(p->bad_object_sha1);
652 *pp = p->next;
653 free(p);
654 return;
656 pp = &p->next;
661 * Do not call this directly as this leaks p->pack_fd on error return;
662 * call open_packed_git() instead.
664 static int open_packed_git_1(struct packed_git *p)
666 struct stat st;
667 struct pack_header hdr;
668 unsigned char sha1[20];
669 unsigned char *idx_sha1;
670 long fd_flag;
672 if (!p->index_data && open_pack_index(p))
673 return error("packfile %s index unavailable", p->pack_name);
675 p->pack_fd = git_open_noatime(p->pack_name, p);
676 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
677 return -1;
679 /* If we created the struct before we had the pack we lack size. */
680 if (!p->pack_size) {
681 if (!S_ISREG(st.st_mode))
682 return error("packfile %s not a regular file", p->pack_name);
683 p->pack_size = st.st_size;
684 } else if (p->pack_size != st.st_size)
685 return error("packfile %s size changed", p->pack_name);
687 /* We leave these file descriptors open with sliding mmap;
688 * there is no point keeping them open across exec(), though.
690 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
691 if (fd_flag < 0)
692 return error("cannot determine file descriptor flags");
693 fd_flag |= FD_CLOEXEC;
694 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
695 return error("cannot set FD_CLOEXEC");
697 /* Verify we recognize this pack file format. */
698 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
699 return error("file %s is far too short to be a packfile", p->pack_name);
700 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
701 return error("file %s is not a GIT packfile", p->pack_name);
702 if (!pack_version_ok(hdr.hdr_version))
703 return error("packfile %s is version %"PRIu32" and not"
704 " supported (try upgrading GIT to a newer version)",
705 p->pack_name, ntohl(hdr.hdr_version));
707 /* Verify the pack matches its index. */
708 if (p->num_objects != ntohl(hdr.hdr_entries))
709 return error("packfile %s claims to have %"PRIu32" objects"
710 " while index indicates %"PRIu32" objects",
711 p->pack_name, ntohl(hdr.hdr_entries),
712 p->num_objects);
713 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
714 return error("end of packfile %s is unavailable", p->pack_name);
715 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
716 return error("packfile %s signature is unavailable", p->pack_name);
717 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
718 if (hashcmp(sha1, idx_sha1))
719 return error("packfile %s does not match index", p->pack_name);
720 return 0;
723 static int open_packed_git(struct packed_git *p)
725 if (!open_packed_git_1(p))
726 return 0;
727 if (p->pack_fd != -1) {
728 close(p->pack_fd);
729 p->pack_fd = -1;
731 return -1;
734 static int in_window(struct pack_window *win, off_t offset)
736 /* We must promise at least 20 bytes (one hash) after the
737 * offset is available from this window, otherwise the offset
738 * is not actually in this window and a different window (which
739 * has that one hash excess) must be used. This is to support
740 * the object header and delta base parsing routines below.
742 off_t win_off = win->offset;
743 return win_off <= offset
744 && (offset + 20) <= (win_off + win->len);
747 unsigned char *use_pack(struct packed_git *p,
748 struct pack_window **w_cursor,
749 off_t offset,
750 unsigned int *left)
752 struct pack_window *win = *w_cursor;
754 if (p->pack_fd == -1 && open_packed_git(p))
755 die("packfile %s cannot be accessed", p->pack_name);
757 /* Since packfiles end in a hash of their content and it's
758 * pointless to ask for an offset into the middle of that
759 * hash, and the in_window function above wouldn't match
760 * don't allow an offset too close to the end of the file.
762 if (offset > (p->pack_size - 20))
763 die("offset beyond end of packfile (truncated pack?)");
765 if (!win || !in_window(win, offset)) {
766 if (win)
767 win->inuse_cnt--;
768 for (win = p->windows; win; win = win->next) {
769 if (in_window(win, offset))
770 break;
772 if (!win) {
773 size_t window_align = packed_git_window_size / 2;
774 off_t len;
775 win = xcalloc(1, sizeof(*win));
776 win->offset = (offset / window_align) * window_align;
777 len = p->pack_size - win->offset;
778 if (len > packed_git_window_size)
779 len = packed_git_window_size;
780 win->len = (size_t)len;
781 pack_mapped += win->len;
782 while (packed_git_limit < pack_mapped
783 && unuse_one_window(p, p->pack_fd))
784 ; /* nothing */
785 win->base = xmmap(NULL, win->len,
786 PROT_READ, MAP_PRIVATE,
787 p->pack_fd, win->offset);
788 if (win->base == MAP_FAILED)
789 die("packfile %s cannot be mapped: %s",
790 p->pack_name,
791 strerror(errno));
792 pack_mmap_calls++;
793 pack_open_windows++;
794 if (pack_mapped > peak_pack_mapped)
795 peak_pack_mapped = pack_mapped;
796 if (pack_open_windows > peak_pack_open_windows)
797 peak_pack_open_windows = pack_open_windows;
798 win->next = p->windows;
799 p->windows = win;
802 if (win != *w_cursor) {
803 win->last_used = pack_used_ctr++;
804 win->inuse_cnt++;
805 *w_cursor = win;
807 offset -= win->offset;
808 if (left)
809 *left = win->len - xsize_t(offset);
810 return win->base + offset;
813 static struct packed_git *alloc_packed_git(int extra)
815 struct packed_git *p = xmalloc(sizeof(*p) + extra);
816 memset(p, 0, sizeof(*p));
817 p->pack_fd = -1;
818 return p;
821 static void try_to_free_pack_memory(size_t size)
823 release_pack_memory(size, -1);
826 struct packed_git *add_packed_git(const char *path, int path_len, int local)
828 static int have_set_try_to_free_routine;
829 struct stat st;
830 struct packed_git *p = alloc_packed_git(path_len + 2);
832 if (!have_set_try_to_free_routine) {
833 have_set_try_to_free_routine = 1;
834 set_try_to_free_routine(try_to_free_pack_memory);
838 * Make sure a corresponding .pack file exists and that
839 * the index looks sane.
841 path_len -= strlen(".idx");
842 if (path_len < 1) {
843 free(p);
844 return NULL;
846 memcpy(p->pack_name, path, path_len);
848 strcpy(p->pack_name + path_len, ".keep");
849 if (!access(p->pack_name, F_OK))
850 p->pack_keep = 1;
852 strcpy(p->pack_name + path_len, ".pack");
853 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
854 free(p);
855 return NULL;
858 /* ok, it looks sane as far as we can check without
859 * actually mapping the pack file.
861 p->pack_size = st.st_size;
862 p->pack_local = local;
863 p->mtime = st.st_mtime;
864 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
865 hashclr(p->sha1);
866 return p;
869 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
871 const char *path = sha1_pack_name(sha1);
872 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
874 strcpy(p->pack_name, path);
875 hashcpy(p->sha1, sha1);
876 if (check_packed_git_idx(idx_path, p)) {
877 free(p);
878 return NULL;
881 return p;
884 void install_packed_git(struct packed_git *pack)
886 pack->next = packed_git;
887 packed_git = pack;
890 static void prepare_packed_git_one(char *objdir, int local)
892 /* Ensure that this buffer is large enough so that we can
893 append "/pack/" without clobbering the stack even if
894 strlen(objdir) were PATH_MAX. */
895 char path[PATH_MAX + 1 + 4 + 1 + 1];
896 int len;
897 DIR *dir;
898 struct dirent *de;
900 sprintf(path, "%s/pack", objdir);
901 len = strlen(path);
902 dir = opendir(path);
903 while (!dir && errno == EMFILE && unuse_one_window(NULL, -1))
904 dir = opendir(path);
905 if (!dir) {
906 if (errno != ENOENT)
907 error("unable to open object pack directory: %s: %s",
908 path, strerror(errno));
909 return;
911 path[len++] = '/';
912 while ((de = readdir(dir)) != NULL) {
913 int namelen = strlen(de->d_name);
914 struct packed_git *p;
916 if (!has_extension(de->d_name, ".idx"))
917 continue;
919 if (len + namelen + 1 > sizeof(path))
920 continue;
922 /* Don't reopen a pack we already have. */
923 strcpy(path + len, de->d_name);
924 for (p = packed_git; p; p = p->next) {
925 if (!memcmp(path, p->pack_name, len + namelen - 4))
926 break;
928 if (p)
929 continue;
930 /* See if it really is a valid .idx file with corresponding
931 * .pack file that we can map.
933 p = add_packed_git(path, len + namelen, local);
934 if (!p)
935 continue;
936 install_packed_git(p);
938 closedir(dir);
941 static int sort_pack(const void *a_, const void *b_)
943 struct packed_git *a = *((struct packed_git **)a_);
944 struct packed_git *b = *((struct packed_git **)b_);
945 int st;
948 * Local packs tend to contain objects specific to our
949 * variant of the project than remote ones. In addition,
950 * remote ones could be on a network mounted filesystem.
951 * Favor local ones for these reasons.
953 st = a->pack_local - b->pack_local;
954 if (st)
955 return -st;
958 * Younger packs tend to contain more recent objects,
959 * and more recent objects tend to get accessed more
960 * often.
962 if (a->mtime < b->mtime)
963 return 1;
964 else if (a->mtime == b->mtime)
965 return 0;
966 return -1;
969 static void rearrange_packed_git(void)
971 struct packed_git **ary, *p;
972 int i, n;
974 for (n = 0, p = packed_git; p; p = p->next)
975 n++;
976 if (n < 2)
977 return;
979 /* prepare an array of packed_git for easier sorting */
980 ary = xcalloc(n, sizeof(struct packed_git *));
981 for (n = 0, p = packed_git; p; p = p->next)
982 ary[n++] = p;
984 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
986 /* link them back again */
987 for (i = 0; i < n - 1; i++)
988 ary[i]->next = ary[i + 1];
989 ary[n - 1]->next = NULL;
990 packed_git = ary[0];
992 free(ary);
995 static int prepare_packed_git_run_once = 0;
996 void prepare_packed_git(void)
998 struct alternate_object_database *alt;
1000 if (prepare_packed_git_run_once)
1001 return;
1002 prepare_packed_git_one(get_object_directory(), 1);
1003 prepare_alt_odb();
1004 for (alt = alt_odb_list; alt; alt = alt->next) {
1005 alt->name[-1] = 0;
1006 prepare_packed_git_one(alt->base, 0);
1007 alt->name[-1] = '/';
1009 rearrange_packed_git();
1010 prepare_packed_git_run_once = 1;
1013 void reprepare_packed_git(void)
1015 discard_revindex();
1016 prepare_packed_git_run_once = 0;
1017 prepare_packed_git();
1020 static void mark_bad_packed_object(struct packed_git *p,
1021 const unsigned char *sha1)
1023 unsigned i;
1024 for (i = 0; i < p->num_bad_objects; i++)
1025 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1026 return;
1027 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1028 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1029 p->num_bad_objects++;
1032 static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1034 struct packed_git *p;
1035 unsigned i;
1037 for (p = packed_git; p; p = p->next)
1038 for (i = 0; i < p->num_bad_objects; i++)
1039 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1040 return p;
1041 return NULL;
1044 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
1046 unsigned char real_sha1[20];
1047 hash_sha1_file(map, size, type, real_sha1);
1048 return hashcmp(sha1, real_sha1) ? -1 : 0;
1051 static int git_open_noatime(const char *name, struct packed_git *p)
1053 static int sha1_file_open_flag = O_NOATIME;
1055 for (;;) {
1056 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1057 if (fd >= 0)
1058 return fd;
1060 /* Might the failure be insufficient file descriptors? */
1061 if (errno == EMFILE) {
1062 if (unuse_one_window(p, -1))
1063 continue;
1064 else
1065 return -1;
1068 /* Might the failure be due to O_NOATIME? */
1069 if (errno != ENOENT && sha1_file_open_flag) {
1070 sha1_file_open_flag = 0;
1071 continue;
1074 return -1;
1078 static int open_sha1_file(const unsigned char *sha1)
1080 int fd;
1081 char *name = sha1_file_name(sha1);
1082 struct alternate_object_database *alt;
1084 fd = git_open_noatime(name, NULL);
1085 if (fd >= 0)
1086 return fd;
1088 prepare_alt_odb();
1089 errno = ENOENT;
1090 for (alt = alt_odb_list; alt; alt = alt->next) {
1091 name = alt->name;
1092 fill_sha1_path(name, sha1);
1093 fd = git_open_noatime(alt->base, NULL);
1094 if (fd >= 0)
1095 return fd;
1097 return -1;
1100 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1102 void *map;
1103 int fd;
1105 fd = open_sha1_file(sha1);
1106 map = NULL;
1107 if (fd >= 0) {
1108 struct stat st;
1110 if (!fstat(fd, &st)) {
1111 *size = xsize_t(st.st_size);
1112 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1114 close(fd);
1116 return map;
1119 static int legacy_loose_object(unsigned char *map)
1121 unsigned int word;
1124 * Is it a zlib-compressed buffer? If so, the first byte
1125 * must be 0x78 (15-bit window size, deflated), and the
1126 * first 16-bit word is evenly divisible by 31
1128 word = (map[0] << 8) + map[1];
1129 if (map[0] == 0x78 && !(word % 31))
1130 return 1;
1131 else
1132 return 0;
1135 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1136 unsigned long len, enum object_type *type, unsigned long *sizep)
1138 unsigned shift;
1139 unsigned long size, c;
1140 unsigned long used = 0;
1142 c = buf[used++];
1143 *type = (c >> 4) & 7;
1144 size = c & 15;
1145 shift = 4;
1146 while (c & 0x80) {
1147 if (len <= used || bitsizeof(long) <= shift) {
1148 error("bad object header");
1149 return 0;
1151 c = buf[used++];
1152 size += (c & 0x7f) << shift;
1153 shift += 7;
1155 *sizep = size;
1156 return used;
1159 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1161 unsigned long size, used;
1162 static const char valid_loose_object_type[8] = {
1163 0, /* OBJ_EXT */
1164 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1165 0, /* "delta" and others are invalid in a loose object */
1167 enum object_type type;
1169 /* Get the data stream */
1170 memset(stream, 0, sizeof(*stream));
1171 stream->next_in = map;
1172 stream->avail_in = mapsize;
1173 stream->next_out = buffer;
1174 stream->avail_out = bufsiz;
1176 if (legacy_loose_object(map)) {
1177 git_inflate_init(stream);
1178 return git_inflate(stream, 0);
1183 * There used to be a second loose object header format which
1184 * was meant to mimic the in-pack format, allowing for direct
1185 * copy of the object data. This format turned up not to be
1186 * really worth it and we don't write it any longer. But we
1187 * can still read it.
1189 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1190 if (!used || !valid_loose_object_type[type])
1191 return -1;
1192 map += used;
1193 mapsize -= used;
1195 /* Set up the stream for the rest.. */
1196 stream->next_in = map;
1197 stream->avail_in = mapsize;
1198 git_inflate_init(stream);
1200 /* And generate the fake traditional header */
1201 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1202 typename(type), size);
1203 return 0;
1206 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1208 int bytes = strlen(buffer) + 1;
1209 unsigned char *buf = xmallocz(size);
1210 unsigned long n;
1211 int status = Z_OK;
1213 n = stream->total_out - bytes;
1214 if (n > size)
1215 n = size;
1216 memcpy(buf, (char *) buffer + bytes, n);
1217 bytes = n;
1218 if (bytes <= size) {
1220 * The above condition must be (bytes <= size), not
1221 * (bytes < size). In other words, even though we
1222 * expect no more output and set avail_out to zer0,
1223 * the input zlib stream may have bytes that express
1224 * "this concludes the stream", and we *do* want to
1225 * eat that input.
1227 * Otherwise we would not be able to test that we
1228 * consumed all the input to reach the expected size;
1229 * we also want to check that zlib tells us that all
1230 * went well with status == Z_STREAM_END at the end.
1232 stream->next_out = buf + bytes;
1233 stream->avail_out = size - bytes;
1234 while (status == Z_OK)
1235 status = git_inflate(stream, Z_FINISH);
1237 if (status == Z_STREAM_END && !stream->avail_in) {
1238 git_inflate_end(stream);
1239 return buf;
1242 if (status < 0)
1243 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1244 else if (stream->avail_in)
1245 error("garbage at end of loose object '%s'",
1246 sha1_to_hex(sha1));
1247 free(buf);
1248 return NULL;
1252 * We used to just use "sscanf()", but that's actually way
1253 * too permissive for what we want to check. So do an anal
1254 * object header parse by hand.
1256 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1258 char type[10];
1259 int i;
1260 unsigned long size;
1263 * The type can be at most ten bytes (including the
1264 * terminating '\0' that we add), and is followed by
1265 * a space.
1267 i = 0;
1268 for (;;) {
1269 char c = *hdr++;
1270 if (c == ' ')
1271 break;
1272 type[i++] = c;
1273 if (i >= sizeof(type))
1274 return -1;
1276 type[i] = 0;
1279 * The length must follow immediately, and be in canonical
1280 * decimal format (ie "010" is not valid).
1282 size = *hdr++ - '0';
1283 if (size > 9)
1284 return -1;
1285 if (size) {
1286 for (;;) {
1287 unsigned long c = *hdr - '0';
1288 if (c > 9)
1289 break;
1290 hdr++;
1291 size = size * 10 + c;
1294 *sizep = size;
1297 * The length must be followed by a zero byte
1299 return *hdr ? -1 : type_from_string(type);
1302 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1304 int ret;
1305 z_stream stream;
1306 char hdr[8192];
1308 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1309 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1310 return NULL;
1312 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1315 unsigned long get_size_from_delta(struct packed_git *p,
1316 struct pack_window **w_curs,
1317 off_t curpos)
1319 const unsigned char *data;
1320 unsigned char delta_head[20], *in;
1321 z_stream stream;
1322 int st;
1324 memset(&stream, 0, sizeof(stream));
1325 stream.next_out = delta_head;
1326 stream.avail_out = sizeof(delta_head);
1328 git_inflate_init(&stream);
1329 do {
1330 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1331 stream.next_in = in;
1332 st = git_inflate(&stream, Z_FINISH);
1333 curpos += stream.next_in - in;
1334 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1335 stream.total_out < sizeof(delta_head));
1336 git_inflate_end(&stream);
1337 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1338 error("delta data unpack-initial failed");
1339 return 0;
1342 /* Examine the initial part of the delta to figure out
1343 * the result size.
1345 data = delta_head;
1347 /* ignore base size */
1348 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1350 /* Read the result size */
1351 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1354 static off_t get_delta_base(struct packed_git *p,
1355 struct pack_window **w_curs,
1356 off_t *curpos,
1357 enum object_type type,
1358 off_t delta_obj_offset)
1360 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1361 off_t base_offset;
1363 /* use_pack() assured us we have [base_info, base_info + 20)
1364 * as a range that we can look at without walking off the
1365 * end of the mapped window. Its actually the hash size
1366 * that is assured. An OFS_DELTA longer than the hash size
1367 * is stupid, as then a REF_DELTA would be smaller to store.
1369 if (type == OBJ_OFS_DELTA) {
1370 unsigned used = 0;
1371 unsigned char c = base_info[used++];
1372 base_offset = c & 127;
1373 while (c & 128) {
1374 base_offset += 1;
1375 if (!base_offset || MSB(base_offset, 7))
1376 return 0; /* overflow */
1377 c = base_info[used++];
1378 base_offset = (base_offset << 7) + (c & 127);
1380 base_offset = delta_obj_offset - base_offset;
1381 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1382 return 0; /* out of bound */
1383 *curpos += used;
1384 } else if (type == OBJ_REF_DELTA) {
1385 /* The base entry _must_ be in the same pack */
1386 base_offset = find_pack_entry_one(base_info, p);
1387 *curpos += 20;
1388 } else
1389 die("I am totally screwed");
1390 return base_offset;
1393 /* forward declaration for a mutually recursive function */
1394 static int packed_object_info(struct packed_git *p, off_t offset,
1395 unsigned long *sizep);
1397 static int packed_delta_info(struct packed_git *p,
1398 struct pack_window **w_curs,
1399 off_t curpos,
1400 enum object_type type,
1401 off_t obj_offset,
1402 unsigned long *sizep)
1404 off_t base_offset;
1406 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1407 if (!base_offset)
1408 return OBJ_BAD;
1409 type = packed_object_info(p, base_offset, NULL);
1410 if (type <= OBJ_NONE) {
1411 struct revindex_entry *revidx;
1412 const unsigned char *base_sha1;
1413 revidx = find_pack_revindex(p, base_offset);
1414 if (!revidx)
1415 return OBJ_BAD;
1416 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1417 mark_bad_packed_object(p, base_sha1);
1418 type = sha1_object_info(base_sha1, NULL);
1419 if (type <= OBJ_NONE)
1420 return OBJ_BAD;
1423 /* We choose to only get the type of the base object and
1424 * ignore potentially corrupt pack file that expects the delta
1425 * based on a base with a wrong size. This saves tons of
1426 * inflate() calls.
1428 if (sizep) {
1429 *sizep = get_size_from_delta(p, w_curs, curpos);
1430 if (*sizep == 0)
1431 type = OBJ_BAD;
1434 return type;
1437 static int unpack_object_header(struct packed_git *p,
1438 struct pack_window **w_curs,
1439 off_t *curpos,
1440 unsigned long *sizep)
1442 unsigned char *base;
1443 unsigned int left;
1444 unsigned long used;
1445 enum object_type type;
1447 /* use_pack() assures us we have [base, base + 20) available
1448 * as a range that we can look at at. (Its actually the hash
1449 * size that is assured.) With our object header encoding
1450 * the maximum deflated object size is 2^137, which is just
1451 * insane, so we know won't exceed what we have been given.
1453 base = use_pack(p, w_curs, *curpos, &left);
1454 used = unpack_object_header_buffer(base, left, &type, sizep);
1455 if (!used) {
1456 type = OBJ_BAD;
1457 } else
1458 *curpos += used;
1460 return type;
1463 const char *packed_object_info_detail(struct packed_git *p,
1464 off_t obj_offset,
1465 unsigned long *size,
1466 unsigned long *store_size,
1467 unsigned int *delta_chain_length,
1468 unsigned char *base_sha1)
1470 struct pack_window *w_curs = NULL;
1471 off_t curpos;
1472 unsigned long dummy;
1473 unsigned char *next_sha1;
1474 enum object_type type;
1475 struct revindex_entry *revidx;
1477 *delta_chain_length = 0;
1478 curpos = obj_offset;
1479 type = unpack_object_header(p, &w_curs, &curpos, size);
1481 revidx = find_pack_revindex(p, obj_offset);
1482 *store_size = revidx[1].offset - obj_offset;
1484 for (;;) {
1485 switch (type) {
1486 default:
1487 die("pack %s contains unknown object type %d",
1488 p->pack_name, type);
1489 case OBJ_COMMIT:
1490 case OBJ_TREE:
1491 case OBJ_BLOB:
1492 case OBJ_TAG:
1493 unuse_pack(&w_curs);
1494 return typename(type);
1495 case OBJ_OFS_DELTA:
1496 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1497 if (!obj_offset)
1498 die("pack %s contains bad delta base reference of type %s",
1499 p->pack_name, typename(type));
1500 if (*delta_chain_length == 0) {
1501 revidx = find_pack_revindex(p, obj_offset);
1502 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
1504 break;
1505 case OBJ_REF_DELTA:
1506 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1507 if (*delta_chain_length == 0)
1508 hashcpy(base_sha1, next_sha1);
1509 obj_offset = find_pack_entry_one(next_sha1, p);
1510 break;
1512 (*delta_chain_length)++;
1513 curpos = obj_offset;
1514 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1518 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1519 unsigned long *sizep)
1521 struct pack_window *w_curs = NULL;
1522 unsigned long size;
1523 off_t curpos = obj_offset;
1524 enum object_type type;
1526 type = unpack_object_header(p, &w_curs, &curpos, &size);
1528 switch (type) {
1529 case OBJ_OFS_DELTA:
1530 case OBJ_REF_DELTA:
1531 type = packed_delta_info(p, &w_curs, curpos,
1532 type, obj_offset, sizep);
1533 break;
1534 case OBJ_COMMIT:
1535 case OBJ_TREE:
1536 case OBJ_BLOB:
1537 case OBJ_TAG:
1538 if (sizep)
1539 *sizep = size;
1540 break;
1541 default:
1542 error("unknown object type %i at offset %"PRIuMAX" in %s",
1543 type, (uintmax_t)obj_offset, p->pack_name);
1544 type = OBJ_BAD;
1546 unuse_pack(&w_curs);
1547 return type;
1550 static void *unpack_compressed_entry(struct packed_git *p,
1551 struct pack_window **w_curs,
1552 off_t curpos,
1553 unsigned long size)
1555 int st;
1556 z_stream stream;
1557 unsigned char *buffer, *in;
1559 buffer = xmallocz(size);
1560 memset(&stream, 0, sizeof(stream));
1561 stream.next_out = buffer;
1562 stream.avail_out = size + 1;
1564 git_inflate_init(&stream);
1565 do {
1566 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1567 stream.next_in = in;
1568 st = git_inflate(&stream, Z_FINISH);
1569 if (!stream.avail_out)
1570 break; /* the payload is larger than it should be */
1571 curpos += stream.next_in - in;
1572 } while (st == Z_OK || st == Z_BUF_ERROR);
1573 git_inflate_end(&stream);
1574 if ((st != Z_STREAM_END) || stream.total_out != size) {
1575 free(buffer);
1576 return NULL;
1579 return buffer;
1582 #define MAX_DELTA_CACHE (256)
1584 static size_t delta_base_cached;
1586 static struct delta_base_cache_lru_list {
1587 struct delta_base_cache_lru_list *prev;
1588 struct delta_base_cache_lru_list *next;
1589 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1591 static struct delta_base_cache_entry {
1592 struct delta_base_cache_lru_list lru;
1593 void *data;
1594 struct packed_git *p;
1595 off_t base_offset;
1596 unsigned long size;
1597 enum object_type type;
1598 } delta_base_cache[MAX_DELTA_CACHE];
1600 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1602 unsigned long hash;
1604 hash = (unsigned long)p + (unsigned long)base_offset;
1605 hash += (hash >> 8) + (hash >> 16);
1606 return hash % MAX_DELTA_CACHE;
1609 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1610 unsigned long *base_size, enum object_type *type, int keep_cache)
1612 void *ret;
1613 unsigned long hash = pack_entry_hash(p, base_offset);
1614 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1616 ret = ent->data;
1617 if (!ret || ent->p != p || ent->base_offset != base_offset)
1618 return unpack_entry(p, base_offset, type, base_size);
1620 if (!keep_cache) {
1621 ent->data = NULL;
1622 ent->lru.next->prev = ent->lru.prev;
1623 ent->lru.prev->next = ent->lru.next;
1624 delta_base_cached -= ent->size;
1625 } else {
1626 ret = xmemdupz(ent->data, ent->size);
1628 *type = ent->type;
1629 *base_size = ent->size;
1630 return ret;
1633 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1635 if (ent->data) {
1636 free(ent->data);
1637 ent->data = NULL;
1638 ent->lru.next->prev = ent->lru.prev;
1639 ent->lru.prev->next = ent->lru.next;
1640 delta_base_cached -= ent->size;
1644 void clear_delta_base_cache(void)
1646 unsigned long p;
1647 for (p = 0; p < MAX_DELTA_CACHE; p++)
1648 release_delta_base_cache(&delta_base_cache[p]);
1651 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1652 void *base, unsigned long base_size, enum object_type type)
1654 unsigned long hash = pack_entry_hash(p, base_offset);
1655 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1656 struct delta_base_cache_lru_list *lru;
1658 release_delta_base_cache(ent);
1659 delta_base_cached += base_size;
1661 for (lru = delta_base_cache_lru.next;
1662 delta_base_cached > delta_base_cache_limit
1663 && lru != &delta_base_cache_lru;
1664 lru = lru->next) {
1665 struct delta_base_cache_entry *f = (void *)lru;
1666 if (f->type == OBJ_BLOB)
1667 release_delta_base_cache(f);
1669 for (lru = delta_base_cache_lru.next;
1670 delta_base_cached > delta_base_cache_limit
1671 && lru != &delta_base_cache_lru;
1672 lru = lru->next) {
1673 struct delta_base_cache_entry *f = (void *)lru;
1674 release_delta_base_cache(f);
1677 ent->p = p;
1678 ent->base_offset = base_offset;
1679 ent->type = type;
1680 ent->data = base;
1681 ent->size = base_size;
1682 ent->lru.next = &delta_base_cache_lru;
1683 ent->lru.prev = delta_base_cache_lru.prev;
1684 delta_base_cache_lru.prev->next = &ent->lru;
1685 delta_base_cache_lru.prev = &ent->lru;
1688 static void *read_object(const unsigned char *sha1, enum object_type *type,
1689 unsigned long *size);
1691 static void *unpack_delta_entry(struct packed_git *p,
1692 struct pack_window **w_curs,
1693 off_t curpos,
1694 unsigned long delta_size,
1695 off_t obj_offset,
1696 enum object_type *type,
1697 unsigned long *sizep)
1699 void *delta_data, *result, *base;
1700 unsigned long base_size;
1701 off_t base_offset;
1703 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1704 if (!base_offset) {
1705 error("failed to validate delta base reference "
1706 "at offset %"PRIuMAX" from %s",
1707 (uintmax_t)curpos, p->pack_name);
1708 return NULL;
1710 unuse_pack(w_curs);
1711 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1712 if (!base) {
1714 * We're probably in deep shit, but let's try to fetch
1715 * the required base anyway from another pack or loose.
1716 * This is costly but should happen only in the presence
1717 * of a corrupted pack, and is better than failing outright.
1719 struct revindex_entry *revidx;
1720 const unsigned char *base_sha1;
1721 revidx = find_pack_revindex(p, base_offset);
1722 if (!revidx)
1723 return NULL;
1724 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1725 error("failed to read delta base object %s"
1726 " at offset %"PRIuMAX" from %s",
1727 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1728 p->pack_name);
1729 mark_bad_packed_object(p, base_sha1);
1730 base = read_object(base_sha1, type, &base_size);
1731 if (!base)
1732 return NULL;
1735 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1736 if (!delta_data) {
1737 error("failed to unpack compressed delta "
1738 "at offset %"PRIuMAX" from %s",
1739 (uintmax_t)curpos, p->pack_name);
1740 free(base);
1741 return NULL;
1743 result = patch_delta(base, base_size,
1744 delta_data, delta_size,
1745 sizep);
1746 if (!result)
1747 die("failed to apply delta");
1748 free(delta_data);
1749 add_delta_base_cache(p, base_offset, base, base_size, *type);
1750 return result;
1753 int do_check_packed_object_crc;
1755 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1756 enum object_type *type, unsigned long *sizep)
1758 struct pack_window *w_curs = NULL;
1759 off_t curpos = obj_offset;
1760 void *data;
1762 if (do_check_packed_object_crc && p->index_version > 1) {
1763 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1764 unsigned long len = revidx[1].offset - obj_offset;
1765 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1766 const unsigned char *sha1 =
1767 nth_packed_object_sha1(p, revidx->nr);
1768 error("bad packed object CRC for %s",
1769 sha1_to_hex(sha1));
1770 mark_bad_packed_object(p, sha1);
1771 unuse_pack(&w_curs);
1772 return NULL;
1776 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1777 switch (*type) {
1778 case OBJ_OFS_DELTA:
1779 case OBJ_REF_DELTA:
1780 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1781 obj_offset, type, sizep);
1782 break;
1783 case OBJ_COMMIT:
1784 case OBJ_TREE:
1785 case OBJ_BLOB:
1786 case OBJ_TAG:
1787 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1788 break;
1789 default:
1790 data = NULL;
1791 error("unknown object type %i at offset %"PRIuMAX" in %s",
1792 *type, (uintmax_t)obj_offset, p->pack_name);
1794 unuse_pack(&w_curs);
1795 return data;
1798 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1799 uint32_t n)
1801 const unsigned char *index = p->index_data;
1802 if (!index) {
1803 if (open_pack_index(p))
1804 return NULL;
1805 index = p->index_data;
1807 if (n >= p->num_objects)
1808 return NULL;
1809 index += 4 * 256;
1810 if (p->index_version == 1) {
1811 return index + 24 * n + 4;
1812 } else {
1813 index += 8;
1814 return index + 20 * n;
1818 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1820 const unsigned char *index = p->index_data;
1821 index += 4 * 256;
1822 if (p->index_version == 1) {
1823 return ntohl(*((uint32_t *)(index + 24 * n)));
1824 } else {
1825 uint32_t off;
1826 index += 8 + p->num_objects * (20 + 4);
1827 off = ntohl(*((uint32_t *)(index + 4 * n)));
1828 if (!(off & 0x80000000))
1829 return off;
1830 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1831 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1832 ntohl(*((uint32_t *)(index + 4)));
1836 off_t find_pack_entry_one(const unsigned char *sha1,
1837 struct packed_git *p)
1839 const uint32_t *level1_ofs = p->index_data;
1840 const unsigned char *index = p->index_data;
1841 unsigned hi, lo, stride;
1842 static int use_lookup = -1;
1843 static int debug_lookup = -1;
1845 if (debug_lookup < 0)
1846 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
1848 if (!index) {
1849 if (open_pack_index(p))
1850 return 0;
1851 level1_ofs = p->index_data;
1852 index = p->index_data;
1854 if (p->index_version > 1) {
1855 level1_ofs += 2;
1856 index += 8;
1858 index += 4 * 256;
1859 hi = ntohl(level1_ofs[*sha1]);
1860 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1861 if (p->index_version > 1) {
1862 stride = 20;
1863 } else {
1864 stride = 24;
1865 index += 4;
1868 if (debug_lookup)
1869 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
1870 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1872 if (use_lookup < 0)
1873 use_lookup = !!getenv("GIT_USE_LOOKUP");
1874 if (use_lookup) {
1875 int pos = sha1_entry_pos(index, stride, 0,
1876 lo, hi, p->num_objects, sha1);
1877 if (pos < 0)
1878 return 0;
1879 return nth_packed_object_offset(p, pos);
1882 do {
1883 unsigned mi = (lo + hi) / 2;
1884 int cmp = hashcmp(index + mi * stride, sha1);
1886 if (debug_lookup)
1887 printf("lo %u hi %u rg %u mi %u\n",
1888 lo, hi, hi - lo, mi);
1889 if (!cmp)
1890 return nth_packed_object_offset(p, mi);
1891 if (cmp > 0)
1892 hi = mi;
1893 else
1894 lo = mi+1;
1895 } while (lo < hi);
1896 return 0;
1899 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1901 static struct packed_git *last_found = (void *)1;
1902 struct packed_git *p;
1903 off_t offset;
1905 prepare_packed_git();
1906 if (!packed_git)
1907 return 0;
1908 p = (last_found == (void *)1) ? packed_git : last_found;
1910 do {
1911 if (p->num_bad_objects) {
1912 unsigned i;
1913 for (i = 0; i < p->num_bad_objects; i++)
1914 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1915 goto next;
1918 offset = find_pack_entry_one(sha1, p);
1919 if (offset) {
1921 * We are about to tell the caller where they can
1922 * locate the requested object. We better make
1923 * sure the packfile is still here and can be
1924 * accessed before supplying that answer, as
1925 * it may have been deleted since the index
1926 * was loaded!
1928 if (p->pack_fd == -1 && open_packed_git(p)) {
1929 error("packfile %s cannot be accessed", p->pack_name);
1930 goto next;
1932 e->offset = offset;
1933 e->p = p;
1934 hashcpy(e->sha1, sha1);
1935 last_found = p;
1936 return 1;
1939 next:
1940 if (p == last_found)
1941 p = packed_git;
1942 else
1943 p = p->next;
1944 if (p == last_found)
1945 p = p->next;
1946 } while (p);
1947 return 0;
1950 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1951 struct packed_git *packs)
1953 struct packed_git *p;
1955 for (p = packs; p; p = p->next) {
1956 if (find_pack_entry_one(sha1, p))
1957 return p;
1959 return NULL;
1963 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1965 int status;
1966 unsigned long mapsize, size;
1967 void *map;
1968 z_stream stream;
1969 char hdr[32];
1971 map = map_sha1_file(sha1, &mapsize);
1972 if (!map)
1973 return error("unable to find %s", sha1_to_hex(sha1));
1974 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1975 status = error("unable to unpack %s header",
1976 sha1_to_hex(sha1));
1977 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1978 status = error("unable to parse %s header", sha1_to_hex(sha1));
1979 else if (sizep)
1980 *sizep = size;
1981 git_inflate_end(&stream);
1982 munmap(map, mapsize);
1983 return status;
1986 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1988 struct pack_entry e;
1989 int status;
1991 if (!find_pack_entry(sha1, &e)) {
1992 /* Most likely it's a loose object. */
1993 status = sha1_loose_object_info(sha1, sizep);
1994 if (status >= 0)
1995 return status;
1997 /* Not a loose object; someone else may have just packed it. */
1998 reprepare_packed_git();
1999 if (!find_pack_entry(sha1, &e))
2000 return status;
2003 status = packed_object_info(e.p, e.offset, sizep);
2004 if (status < 0) {
2005 mark_bad_packed_object(e.p, sha1);
2006 status = sha1_object_info(sha1, sizep);
2009 return status;
2012 static void *read_packed_sha1(const unsigned char *sha1,
2013 enum object_type *type, unsigned long *size)
2015 struct pack_entry e;
2016 void *data;
2018 if (!find_pack_entry(sha1, &e))
2019 return NULL;
2020 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2021 if (!data) {
2023 * We're probably in deep shit, but let's try to fetch
2024 * the required object anyway from another pack or loose.
2025 * This should happen only in the presence of a corrupted
2026 * pack, and is better than failing outright.
2028 error("failed to read object %s at offset %"PRIuMAX" from %s",
2029 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2030 mark_bad_packed_object(e.p, sha1);
2031 data = read_object(sha1, type, size);
2033 return data;
2037 * This is meant to hold a *small* number of objects that you would
2038 * want read_sha1_file() to be able to return, but yet you do not want
2039 * to write them into the object store (e.g. a browse-only
2040 * application).
2042 static struct cached_object {
2043 unsigned char sha1[20];
2044 enum object_type type;
2045 void *buf;
2046 unsigned long size;
2047 } *cached_objects;
2048 static int cached_object_nr, cached_object_alloc;
2050 static struct cached_object empty_tree = {
2051 EMPTY_TREE_SHA1_BIN,
2052 OBJ_TREE,
2057 static struct cached_object *find_cached_object(const unsigned char *sha1)
2059 int i;
2060 struct cached_object *co = cached_objects;
2062 for (i = 0; i < cached_object_nr; i++, co++) {
2063 if (!hashcmp(co->sha1, sha1))
2064 return co;
2066 if (!hashcmp(sha1, empty_tree.sha1))
2067 return &empty_tree;
2068 return NULL;
2071 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2072 unsigned char *sha1)
2074 struct cached_object *co;
2076 hash_sha1_file(buf, len, typename(type), sha1);
2077 if (has_sha1_file(sha1) || find_cached_object(sha1))
2078 return 0;
2079 if (cached_object_alloc <= cached_object_nr) {
2080 cached_object_alloc = alloc_nr(cached_object_alloc);
2081 cached_objects = xrealloc(cached_objects,
2082 sizeof(*cached_objects) *
2083 cached_object_alloc);
2085 co = &cached_objects[cached_object_nr++];
2086 co->size = len;
2087 co->type = type;
2088 co->buf = xmalloc(len);
2089 memcpy(co->buf, buf, len);
2090 hashcpy(co->sha1, sha1);
2091 return 0;
2094 static void *read_object(const unsigned char *sha1, enum object_type *type,
2095 unsigned long *size)
2097 unsigned long mapsize;
2098 void *map, *buf;
2099 struct cached_object *co;
2101 co = find_cached_object(sha1);
2102 if (co) {
2103 *type = co->type;
2104 *size = co->size;
2105 return xmemdupz(co->buf, co->size);
2108 buf = read_packed_sha1(sha1, type, size);
2109 if (buf)
2110 return buf;
2111 map = map_sha1_file(sha1, &mapsize);
2112 if (map) {
2113 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2114 munmap(map, mapsize);
2115 return buf;
2117 reprepare_packed_git();
2118 return read_packed_sha1(sha1, type, size);
2122 * This function dies on corrupt objects; the callers who want to
2123 * deal with them should arrange to call read_object() and give error
2124 * messages themselves.
2126 void *read_sha1_file_repl(const unsigned char *sha1,
2127 enum object_type *type,
2128 unsigned long *size,
2129 const unsigned char **replacement)
2131 const unsigned char *repl = lookup_replace_object(sha1);
2132 void *data;
2133 char *path;
2134 const struct packed_git *p;
2136 errno = 0;
2137 data = read_object(repl, type, size);
2138 if (data) {
2139 if (replacement)
2140 *replacement = repl;
2141 return data;
2144 if (errno && errno != ENOENT)
2145 die_errno("failed to read object %s", sha1_to_hex(sha1));
2147 /* die if we replaced an object with one that does not exist */
2148 if (repl != sha1)
2149 die("replacement %s not found for %s",
2150 sha1_to_hex(repl), sha1_to_hex(sha1));
2152 if (has_loose_object(repl)) {
2153 path = sha1_file_name(sha1);
2154 die("loose object %s (stored in %s) is corrupt",
2155 sha1_to_hex(repl), path);
2158 if ((p = has_packed_and_bad(repl)) != NULL)
2159 die("packed object %s (stored in %s) is corrupt",
2160 sha1_to_hex(repl), p->pack_name);
2162 return NULL;
2165 void *read_object_with_reference(const unsigned char *sha1,
2166 const char *required_type_name,
2167 unsigned long *size,
2168 unsigned char *actual_sha1_return)
2170 enum object_type type, required_type;
2171 void *buffer;
2172 unsigned long isize;
2173 unsigned char actual_sha1[20];
2175 required_type = type_from_string(required_type_name);
2176 hashcpy(actual_sha1, sha1);
2177 while (1) {
2178 int ref_length = -1;
2179 const char *ref_type = NULL;
2181 buffer = read_sha1_file(actual_sha1, &type, &isize);
2182 if (!buffer)
2183 return NULL;
2184 if (type == required_type) {
2185 *size = isize;
2186 if (actual_sha1_return)
2187 hashcpy(actual_sha1_return, actual_sha1);
2188 return buffer;
2190 /* Handle references */
2191 else if (type == OBJ_COMMIT)
2192 ref_type = "tree ";
2193 else if (type == OBJ_TAG)
2194 ref_type = "object ";
2195 else {
2196 free(buffer);
2197 return NULL;
2199 ref_length = strlen(ref_type);
2201 if (ref_length + 40 > isize ||
2202 memcmp(buffer, ref_type, ref_length) ||
2203 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2204 free(buffer);
2205 return NULL;
2207 free(buffer);
2208 /* Now we have the ID of the referred-to object in
2209 * actual_sha1. Check again. */
2213 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2214 const char *type, unsigned char *sha1,
2215 char *hdr, int *hdrlen)
2217 git_SHA_CTX c;
2219 /* Generate the header */
2220 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2222 /* Sha1.. */
2223 git_SHA1_Init(&c);
2224 git_SHA1_Update(&c, hdr, *hdrlen);
2225 git_SHA1_Update(&c, buf, len);
2226 git_SHA1_Final(sha1, &c);
2230 * Move the just written object into its final resting place.
2231 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2232 * "moving" is only a part of what it does, when no patch between
2233 * master to pu changes the call sites of this function.
2235 int move_temp_to_file(const char *tmpfile, const char *filename)
2237 int ret = 0;
2239 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2240 goto try_rename;
2241 else if (link(tmpfile, filename))
2242 ret = errno;
2245 * Coda hack - coda doesn't like cross-directory links,
2246 * so we fall back to a rename, which will mean that it
2247 * won't be able to check collisions, but that's not a
2248 * big deal.
2250 * The same holds for FAT formatted media.
2252 * When this succeeds, we just return. We have nothing
2253 * left to unlink.
2255 if (ret && ret != EEXIST) {
2256 try_rename:
2257 if (!rename(tmpfile, filename))
2258 goto out;
2259 ret = errno;
2261 unlink_or_warn(tmpfile);
2262 if (ret) {
2263 if (ret != EEXIST) {
2264 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
2266 /* FIXME!!! Collision check here ? */
2269 out:
2270 if (adjust_shared_perm(filename))
2271 return error("unable to set permission to '%s'", filename);
2272 return 0;
2275 static int write_buffer(int fd, const void *buf, size_t len)
2277 if (write_in_full(fd, buf, len) < 0)
2278 return error("file write error (%s)", strerror(errno));
2279 return 0;
2282 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2283 unsigned char *sha1)
2285 char hdr[32];
2286 int hdrlen;
2287 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2288 return 0;
2291 /* Finalize a file on disk, and close it. */
2292 static void close_sha1_file(int fd)
2294 if (fsync_object_files)
2295 fsync_or_die(fd, "sha1 file");
2296 if (close(fd) != 0)
2297 die_errno("error when closing sha1 file");
2300 /* Size of directory component, including the ending '/' */
2301 static inline int directory_size(const char *filename)
2303 const char *s = strrchr(filename, '/');
2304 if (!s)
2305 return 0;
2306 return s - filename + 1;
2310 * This creates a temporary file in the same directory as the final
2311 * 'filename'
2313 * We want to avoid cross-directory filename renames, because those
2314 * can have problems on various filesystems (FAT, NFS, Coda).
2316 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2318 int fd, dirlen = directory_size(filename);
2320 if (dirlen + 20 > bufsiz) {
2321 errno = ENAMETOOLONG;
2322 return -1;
2324 memcpy(buffer, filename, dirlen);
2325 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2326 fd = git_mkstemp_mode(buffer, 0444);
2327 if (fd < 0 && dirlen && errno == ENOENT) {
2328 /* Make sure the directory exists */
2329 memcpy(buffer, filename, dirlen);
2330 buffer[dirlen-1] = 0;
2331 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2332 return -1;
2334 /* Try again */
2335 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2336 fd = git_mkstemp_mode(buffer, 0444);
2338 return fd;
2341 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2342 const void *buf, unsigned long len, time_t mtime)
2344 int fd, ret;
2345 unsigned char compressed[4096];
2346 z_stream stream;
2347 git_SHA_CTX c;
2348 unsigned char parano_sha1[20];
2349 char *filename;
2350 static char tmpfile[PATH_MAX];
2352 filename = sha1_file_name(sha1);
2353 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2354 while (fd < 0 && errno == EMFILE && unuse_one_window(NULL, -1))
2355 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2356 if (fd < 0) {
2357 if (errno == EACCES)
2358 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2359 else
2360 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2363 /* Set it up */
2364 memset(&stream, 0, sizeof(stream));
2365 deflateInit(&stream, zlib_compression_level);
2366 stream.next_out = compressed;
2367 stream.avail_out = sizeof(compressed);
2368 git_SHA1_Init(&c);
2370 /* First header.. */
2371 stream.next_in = (unsigned char *)hdr;
2372 stream.avail_in = hdrlen;
2373 while (deflate(&stream, 0) == Z_OK)
2374 /* nothing */;
2375 git_SHA1_Update(&c, hdr, hdrlen);
2377 /* Then the data itself.. */
2378 stream.next_in = (void *)buf;
2379 stream.avail_in = len;
2380 do {
2381 unsigned char *in0 = stream.next_in;
2382 ret = deflate(&stream, Z_FINISH);
2383 git_SHA1_Update(&c, in0, stream.next_in - in0);
2384 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2385 die("unable to write sha1 file");
2386 stream.next_out = compressed;
2387 stream.avail_out = sizeof(compressed);
2388 } while (ret == Z_OK);
2390 if (ret != Z_STREAM_END)
2391 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2392 ret = deflateEnd(&stream);
2393 if (ret != Z_OK)
2394 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2395 git_SHA1_Final(parano_sha1, &c);
2396 if (hashcmp(sha1, parano_sha1) != 0)
2397 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
2399 close_sha1_file(fd);
2401 if (mtime) {
2402 struct utimbuf utb;
2403 utb.actime = mtime;
2404 utb.modtime = mtime;
2405 if (utime(tmpfile, &utb) < 0)
2406 warning("failed utime() on %s: %s",
2407 tmpfile, strerror(errno));
2410 return move_temp_to_file(tmpfile, filename);
2413 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2415 unsigned char sha1[20];
2416 char hdr[32];
2417 int hdrlen;
2419 /* Normally if we have it in the pack then we do not bother writing
2420 * it out into .git/objects/??/?{38} file.
2422 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2423 if (returnsha1)
2424 hashcpy(returnsha1, sha1);
2425 if (has_sha1_file(sha1))
2426 return 0;
2427 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2430 int force_object_loose(const unsigned char *sha1, time_t mtime)
2432 void *buf;
2433 unsigned long len;
2434 enum object_type type;
2435 char hdr[32];
2436 int hdrlen;
2437 int ret;
2439 if (has_loose_object(sha1))
2440 return 0;
2441 buf = read_packed_sha1(sha1, &type, &len);
2442 if (!buf)
2443 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2444 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2445 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2446 free(buf);
2448 return ret;
2451 int has_pack_index(const unsigned char *sha1)
2453 struct stat st;
2454 if (stat(sha1_pack_index_name(sha1), &st))
2455 return 0;
2456 return 1;
2459 int has_sha1_pack(const unsigned char *sha1)
2461 struct pack_entry e;
2462 return find_pack_entry(sha1, &e);
2465 int has_sha1_file(const unsigned char *sha1)
2467 struct pack_entry e;
2469 if (find_pack_entry(sha1, &e))
2470 return 1;
2471 return has_loose_object(sha1);
2474 static int index_mem(unsigned char *sha1, void *buf, size_t size,
2475 int write_object, enum object_type type, const char *path)
2477 int ret, re_allocated = 0;
2479 if (!type)
2480 type = OBJ_BLOB;
2483 * Convert blobs to git internal format
2485 if ((type == OBJ_BLOB) && path) {
2486 struct strbuf nbuf = STRBUF_INIT;
2487 if (convert_to_git(path, buf, size, &nbuf,
2488 write_object ? safe_crlf : 0)) {
2489 buf = strbuf_detach(&nbuf, &size);
2490 re_allocated = 1;
2494 if (write_object)
2495 ret = write_sha1_file(buf, size, typename(type), sha1);
2496 else
2497 ret = hash_sha1_file(buf, size, typename(type), sha1);
2498 if (re_allocated)
2499 free(buf);
2500 return ret;
2503 #define SMALL_FILE_SIZE (32*1024)
2505 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2506 enum object_type type, const char *path)
2508 int ret;
2509 size_t size = xsize_t(st->st_size);
2511 if (!S_ISREG(st->st_mode)) {
2512 struct strbuf sbuf = STRBUF_INIT;
2513 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2514 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2515 type, path);
2516 else
2517 ret = -1;
2518 strbuf_release(&sbuf);
2519 } else if (!size) {
2520 ret = index_mem(sha1, NULL, size, write_object, type, path);
2521 } else if (size <= SMALL_FILE_SIZE) {
2522 char *buf = xmalloc(size);
2523 if (size == read_in_full(fd, buf, size))
2524 ret = index_mem(sha1, buf, size, write_object, type,
2525 path);
2526 else
2527 ret = error("short read %s", strerror(errno));
2528 free(buf);
2529 } else {
2530 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2531 ret = index_mem(sha1, buf, size, write_object, type, path);
2532 munmap(buf, size);
2534 close(fd);
2535 return ret;
2538 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2540 int fd;
2541 struct strbuf sb = STRBUF_INIT;
2543 switch (st->st_mode & S_IFMT) {
2544 case S_IFREG:
2545 fd = open(path, O_RDONLY);
2546 if (fd < 0)
2547 return error("open(\"%s\"): %s", path,
2548 strerror(errno));
2549 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2550 return error("%s: failed to insert into database",
2551 path);
2552 break;
2553 case S_IFLNK:
2554 if (strbuf_readlink(&sb, path, st->st_size)) {
2555 char *errstr = strerror(errno);
2556 return error("readlink(\"%s\"): %s", path,
2557 errstr);
2559 if (!write_object)
2560 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2561 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
2562 return error("%s: failed to insert into database",
2563 path);
2564 strbuf_release(&sb);
2565 break;
2566 case S_IFDIR:
2567 return resolve_gitlink_ref(path, "HEAD", sha1);
2568 default:
2569 return error("%s: unsupported file type", path);
2571 return 0;
2574 int read_pack_header(int fd, struct pack_header *header)
2576 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2577 /* "eof before pack header was fully read" */
2578 return PH_ERROR_EOF;
2580 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2581 /* "protocol error (pack signature mismatch detected)" */
2582 return PH_ERROR_PACK_SIGNATURE;
2583 if (!pack_version_ok(header->hdr_version))
2584 /* "protocol error (pack version unsupported)" */
2585 return PH_ERROR_PROTOCOL;
2586 return 0;
2589 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
2591 enum object_type type = sha1_object_info(sha1, NULL);
2592 if (type < 0)
2593 die("%s is not a valid object", sha1_to_hex(sha1));
2594 if (type != expect)
2595 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
2596 typename(expect));