Merge branch 'tc/commit-dry-run-exit-status-tests'
[git.git] / sha1_file.c
blob400aa463a47c504feec3ca508e7340c6d5dc8268
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "string-list.h"
11 #include "delta.h"
12 #include "pack.h"
13 #include "blob.h"
14 #include "commit.h"
15 #include "run-command.h"
16 #include "tag.h"
17 #include "tree.h"
18 #include "tree-walk.h"
19 #include "refs.h"
20 #include "pack-revindex.h"
21 #include "sha1-lookup.h"
22 #include "bulk-checkin.h"
23 #include "streaming.h"
24 #include "dir.h"
26 #ifndef O_NOATIME
27 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
28 #define O_NOATIME 01000000
29 #else
30 #define O_NOATIME 0
31 #endif
32 #endif
34 #define SZ_FMT PRIuMAX
35 static inline uintmax_t sz_fmt(size_t s) { return s; }
37 const unsigned char null_sha1[20];
39 static const char *no_log_pack_access = "no_log_pack_access";
40 static const char *log_pack_access;
43 * This is meant to hold a *small* number of objects that you would
44 * want read_sha1_file() to be able to return, but yet you do not want
45 * to write them into the object store (e.g. a browse-only
46 * application).
48 static struct cached_object {
49 unsigned char sha1[20];
50 enum object_type type;
51 void *buf;
52 unsigned long size;
53 } *cached_objects;
54 static int cached_object_nr, cached_object_alloc;
56 static struct cached_object empty_tree = {
57 EMPTY_TREE_SHA1_BIN_LITERAL,
58 OBJ_TREE,
59 "",
64 * A pointer to the last packed_git in which an object was found.
65 * When an object is sought, we look in this packfile first, because
66 * objects that are looked up at similar times are often in the same
67 * packfile as one another.
69 static struct packed_git *last_found_pack;
71 static struct cached_object *find_cached_object(const unsigned char *sha1)
73 int i;
74 struct cached_object *co = cached_objects;
76 for (i = 0; i < cached_object_nr; i++, co++) {
77 if (!hashcmp(co->sha1, sha1))
78 return co;
80 if (!hashcmp(sha1, empty_tree.sha1))
81 return &empty_tree;
82 return NULL;
85 int mkdir_in_gitdir(const char *path)
87 if (mkdir(path, 0777)) {
88 int saved_errno = errno;
89 struct stat st;
90 struct strbuf sb = STRBUF_INIT;
92 if (errno != EEXIST)
93 return -1;
95 * Are we looking at a path in a symlinked worktree
96 * whose original repository does not yet have it?
97 * e.g. .git/rr-cache pointing at its original
98 * repository in which the user hasn't performed any
99 * conflict resolution yet?
101 if (lstat(path, &st) || !S_ISLNK(st.st_mode) ||
102 strbuf_readlink(&sb, path, st.st_size) ||
103 !is_absolute_path(sb.buf) ||
104 mkdir(sb.buf, 0777)) {
105 strbuf_release(&sb);
106 errno = saved_errno;
107 return -1;
109 strbuf_release(&sb);
111 return adjust_shared_perm(path);
114 enum scld_error safe_create_leading_directories(char *path)
116 char *next_component = path + offset_1st_component(path);
117 enum scld_error ret = SCLD_OK;
119 while (ret == SCLD_OK && next_component) {
120 struct stat st;
121 char *slash = next_component, slash_character;
123 while (*slash && !is_dir_sep(*slash))
124 slash++;
126 if (!*slash)
127 break;
129 next_component = slash + 1;
130 while (is_dir_sep(*next_component))
131 next_component++;
132 if (!*next_component)
133 break;
135 slash_character = *slash;
136 *slash = '\0';
137 if (!stat(path, &st)) {
138 /* path exists */
139 if (!S_ISDIR(st.st_mode))
140 ret = SCLD_EXISTS;
141 } else if (mkdir(path, 0777)) {
142 if (errno == EEXIST &&
143 !stat(path, &st) && S_ISDIR(st.st_mode))
144 ; /* somebody created it since we checked */
145 else if (errno == ENOENT)
147 * Either mkdir() failed because
148 * somebody just pruned the containing
149 * directory, or stat() failed because
150 * the file that was in our way was
151 * just removed. Either way, inform
152 * the caller that it might be worth
153 * trying again:
155 ret = SCLD_VANISHED;
156 else
157 ret = SCLD_FAILED;
158 } else if (adjust_shared_perm(path)) {
159 ret = SCLD_PERMS;
161 *slash = slash_character;
163 return ret;
166 enum scld_error safe_create_leading_directories_const(const char *path)
168 /* path points to cache entries, so xstrdup before messing with it */
169 char *buf = xstrdup(path);
170 enum scld_error result = safe_create_leading_directories(buf);
171 free(buf);
172 return result;
175 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
177 int i;
178 for (i = 0; i < 20; i++) {
179 static char hex[] = "0123456789abcdef";
180 unsigned int val = sha1[i];
181 char *pos = pathbuf + i*2 + (i > 0);
182 *pos++ = hex[val >> 4];
183 *pos = hex[val & 0xf];
187 const char *sha1_file_name(const unsigned char *sha1)
189 static char buf[PATH_MAX];
190 const char *objdir;
191 int len;
193 objdir = get_object_directory();
194 len = strlen(objdir);
196 /* '/' + sha1(2) + '/' + sha1(38) + '\0' */
197 if (len + 43 > PATH_MAX)
198 die("insanely long object directory %s", objdir);
199 memcpy(buf, objdir, len);
200 buf[len] = '/';
201 buf[len+3] = '/';
202 buf[len+42] = '\0';
203 fill_sha1_path(buf + len + 1, sha1);
204 return buf;
208 * Return the name of the pack or index file with the specified sha1
209 * in its filename. *base and *name are scratch space that must be
210 * provided by the caller. which should be "pack" or "idx".
212 static char *sha1_get_pack_name(const unsigned char *sha1,
213 char **name, char **base, const char *which)
215 static const char hex[] = "0123456789abcdef";
216 char *buf;
217 int i;
219 if (!*base) {
220 const char *sha1_file_directory = get_object_directory();
221 int len = strlen(sha1_file_directory);
222 *base = xmalloc(len + 60);
223 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
224 sha1_file_directory, which);
225 *name = *base + len + 11;
228 buf = *name;
230 for (i = 0; i < 20; i++) {
231 unsigned int val = *sha1++;
232 *buf++ = hex[val >> 4];
233 *buf++ = hex[val & 0xf];
236 return *base;
239 char *sha1_pack_name(const unsigned char *sha1)
241 static char *name, *base;
243 return sha1_get_pack_name(sha1, &name, &base, "pack");
246 char *sha1_pack_index_name(const unsigned char *sha1)
248 static char *name, *base;
250 return sha1_get_pack_name(sha1, &name, &base, "idx");
253 struct alternate_object_database *alt_odb_list;
254 static struct alternate_object_database **alt_odb_tail;
257 * Prepare alternate object database registry.
259 * The variable alt_odb_list points at the list of struct
260 * alternate_object_database. The elements on this list come from
261 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
262 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
263 * whose contents is similar to that environment variable but can be
264 * LF separated. Its base points at a statically allocated buffer that
265 * contains "/the/directory/corresponding/to/.git/objects/...", while
266 * its name points just after the slash at the end of ".git/objects/"
267 * in the example above, and has enough space to hold 40-byte hex
268 * SHA1, an extra slash for the first level indirection, and the
269 * terminating NUL.
271 static int link_alt_odb_entry(const char *entry, const char *relative_base, int depth)
273 const char *objdir = get_object_directory();
274 struct alternate_object_database *ent;
275 struct alternate_object_database *alt;
276 int pfxlen, entlen;
277 struct strbuf pathbuf = STRBUF_INIT;
279 if (!is_absolute_path(entry) && relative_base) {
280 strbuf_addstr(&pathbuf, real_path(relative_base));
281 strbuf_addch(&pathbuf, '/');
283 strbuf_addstr(&pathbuf, entry);
285 normalize_path_copy(pathbuf.buf, pathbuf.buf);
287 pfxlen = strlen(pathbuf.buf);
290 * The trailing slash after the directory name is given by
291 * this function at the end. Remove duplicates.
293 while (pfxlen && pathbuf.buf[pfxlen-1] == '/')
294 pfxlen -= 1;
296 entlen = pfxlen + 43; /* '/' + 2 hex + '/' + 38 hex + NUL */
297 ent = xmalloc(sizeof(*ent) + entlen);
298 memcpy(ent->base, pathbuf.buf, pfxlen);
299 strbuf_release(&pathbuf);
301 ent->name = ent->base + pfxlen + 1;
302 ent->base[pfxlen + 3] = '/';
303 ent->base[pfxlen] = ent->base[entlen-1] = 0;
305 /* Detect cases where alternate disappeared */
306 if (!is_directory(ent->base)) {
307 error("object directory %s does not exist; "
308 "check .git/objects/info/alternates.",
309 ent->base);
310 free(ent);
311 return -1;
314 /* Prevent the common mistake of listing the same
315 * thing twice, or object directory itself.
317 for (alt = alt_odb_list; alt; alt = alt->next) {
318 if (!memcmp(ent->base, alt->base, pfxlen)) {
319 free(ent);
320 return -1;
323 if (!strcmp(ent->base, objdir)) {
324 free(ent);
325 return -1;
328 /* add the alternate entry */
329 *alt_odb_tail = ent;
330 alt_odb_tail = &(ent->next);
331 ent->next = NULL;
333 /* recursively add alternates */
334 read_info_alternates(ent->base, depth + 1);
336 ent->base[pfxlen] = '/';
338 return 0;
341 static void link_alt_odb_entries(const char *alt, int len, int sep,
342 const char *relative_base, int depth)
344 struct string_list entries = STRING_LIST_INIT_NODUP;
345 char *alt_copy;
346 int i;
348 if (depth > 5) {
349 error("%s: ignoring alternate object stores, nesting too deep.",
350 relative_base);
351 return;
354 alt_copy = xmemdupz(alt, len);
355 string_list_split_in_place(&entries, alt_copy, sep, -1);
356 for (i = 0; i < entries.nr; i++) {
357 const char *entry = entries.items[i].string;
358 if (entry[0] == '\0' || entry[0] == '#')
359 continue;
360 if (!is_absolute_path(entry) && depth) {
361 error("%s: ignoring relative alternate object store %s",
362 relative_base, entry);
363 } else {
364 link_alt_odb_entry(entry, relative_base, depth);
367 string_list_clear(&entries, 0);
368 free(alt_copy);
371 void read_info_alternates(const char * relative_base, int depth)
373 char *map;
374 size_t mapsz;
375 struct stat st;
376 const char alt_file_name[] = "info/alternates";
377 /* Given that relative_base is no longer than PATH_MAX,
378 ensure that "path" has enough space to append "/", the
379 file name, "info/alternates", and a trailing NUL. */
380 char path[PATH_MAX + 1 + sizeof alt_file_name];
381 int fd;
383 sprintf(path, "%s/%s", relative_base, alt_file_name);
384 fd = git_open_noatime(path);
385 if (fd < 0)
386 return;
387 if (fstat(fd, &st) || (st.st_size == 0)) {
388 close(fd);
389 return;
391 mapsz = xsize_t(st.st_size);
392 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
393 close(fd);
395 link_alt_odb_entries(map, mapsz, '\n', relative_base, depth);
397 munmap(map, mapsz);
400 void add_to_alternates_file(const char *reference)
402 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
403 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
404 char *alt = mkpath("%s\n", reference);
405 write_or_die(fd, alt, strlen(alt));
406 if (commit_lock_file(lock))
407 die("could not close alternates file");
408 if (alt_odb_tail)
409 link_alt_odb_entries(alt, strlen(alt), '\n', NULL, 0);
412 void foreach_alt_odb(alt_odb_fn fn, void *cb)
414 struct alternate_object_database *ent;
416 prepare_alt_odb();
417 for (ent = alt_odb_list; ent; ent = ent->next)
418 if (fn(ent, cb))
419 return;
422 void prepare_alt_odb(void)
424 const char *alt;
426 if (alt_odb_tail)
427 return;
429 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
430 if (!alt) alt = "";
432 alt_odb_tail = &alt_odb_list;
433 link_alt_odb_entries(alt, strlen(alt), PATH_SEP, NULL, 0);
435 read_info_alternates(get_object_directory(), 0);
438 static int has_loose_object_local(const unsigned char *sha1)
440 return !access(sha1_file_name(sha1), F_OK);
443 int has_loose_object_nonlocal(const unsigned char *sha1)
445 struct alternate_object_database *alt;
446 prepare_alt_odb();
447 for (alt = alt_odb_list; alt; alt = alt->next) {
448 fill_sha1_path(alt->name, sha1);
449 if (!access(alt->base, F_OK))
450 return 1;
452 return 0;
455 static int has_loose_object(const unsigned char *sha1)
457 return has_loose_object_local(sha1) ||
458 has_loose_object_nonlocal(sha1);
461 static unsigned int pack_used_ctr;
462 static unsigned int pack_mmap_calls;
463 static unsigned int peak_pack_open_windows;
464 static unsigned int pack_open_windows;
465 static unsigned int pack_open_fds;
466 static unsigned int pack_max_fds;
467 static size_t peak_pack_mapped;
468 static size_t pack_mapped;
469 struct packed_git *packed_git;
471 void pack_report(void)
473 fprintf(stderr,
474 "pack_report: getpagesize() = %10" SZ_FMT "\n"
475 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
476 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
477 sz_fmt(getpagesize()),
478 sz_fmt(packed_git_window_size),
479 sz_fmt(packed_git_limit));
480 fprintf(stderr,
481 "pack_report: pack_used_ctr = %10u\n"
482 "pack_report: pack_mmap_calls = %10u\n"
483 "pack_report: pack_open_windows = %10u / %10u\n"
484 "pack_report: pack_mapped = "
485 "%10" SZ_FMT " / %10" SZ_FMT "\n",
486 pack_used_ctr,
487 pack_mmap_calls,
488 pack_open_windows, peak_pack_open_windows,
489 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
493 * Open and mmap the index file at path, perform a couple of
494 * consistency checks, then record its information to p. Return 0 on
495 * success.
497 static int check_packed_git_idx(const char *path, struct packed_git *p)
499 void *idx_map;
500 struct pack_idx_header *hdr;
501 size_t idx_size;
502 uint32_t version, nr, i, *index;
503 int fd = git_open_noatime(path);
504 struct stat st;
506 if (fd < 0)
507 return -1;
508 if (fstat(fd, &st)) {
509 close(fd);
510 return -1;
512 idx_size = xsize_t(st.st_size);
513 if (idx_size < 4 * 256 + 20 + 20) {
514 close(fd);
515 return error("index file %s is too small", path);
517 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
518 close(fd);
520 hdr = idx_map;
521 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
522 version = ntohl(hdr->idx_version);
523 if (version < 2 || version > 2) {
524 munmap(idx_map, idx_size);
525 return error("index file %s is version %"PRIu32
526 " and is not supported by this binary"
527 " (try upgrading GIT to a newer version)",
528 path, version);
530 } else
531 version = 1;
533 nr = 0;
534 index = idx_map;
535 if (version > 1)
536 index += 2; /* skip index header */
537 for (i = 0; i < 256; i++) {
538 uint32_t n = ntohl(index[i]);
539 if (n < nr) {
540 munmap(idx_map, idx_size);
541 return error("non-monotonic index %s", path);
543 nr = n;
546 if (version == 1) {
548 * Total size:
549 * - 256 index entries 4 bytes each
550 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
551 * - 20-byte SHA1 of the packfile
552 * - 20-byte SHA1 file checksum
554 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
555 munmap(idx_map, idx_size);
556 return error("wrong index v1 file size in %s", path);
558 } else if (version == 2) {
560 * Minimum size:
561 * - 8 bytes of header
562 * - 256 index entries 4 bytes each
563 * - 20-byte sha1 entry * nr
564 * - 4-byte crc entry * nr
565 * - 4-byte offset entry * nr
566 * - 20-byte SHA1 of the packfile
567 * - 20-byte SHA1 file checksum
568 * And after the 4-byte offset table might be a
569 * variable sized table containing 8-byte entries
570 * for offsets larger than 2^31.
572 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
573 unsigned long max_size = min_size;
574 if (nr)
575 max_size += (nr - 1)*8;
576 if (idx_size < min_size || idx_size > max_size) {
577 munmap(idx_map, idx_size);
578 return error("wrong index v2 file size in %s", path);
580 if (idx_size != min_size &&
582 * make sure we can deal with large pack offsets.
583 * 31-bit signed offset won't be enough, neither
584 * 32-bit unsigned one will be.
586 (sizeof(off_t) <= 4)) {
587 munmap(idx_map, idx_size);
588 return error("pack too large for current definition of off_t in %s", path);
592 p->index_version = version;
593 p->index_data = idx_map;
594 p->index_size = idx_size;
595 p->num_objects = nr;
596 return 0;
599 int open_pack_index(struct packed_git *p)
601 char *idx_name;
602 int ret;
604 if (p->index_data)
605 return 0;
607 idx_name = xstrdup(p->pack_name);
608 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
609 ret = check_packed_git_idx(idx_name, p);
610 free(idx_name);
611 return ret;
614 static void scan_windows(struct packed_git *p,
615 struct packed_git **lru_p,
616 struct pack_window **lru_w,
617 struct pack_window **lru_l)
619 struct pack_window *w, *w_l;
621 for (w_l = NULL, w = p->windows; w; w = w->next) {
622 if (!w->inuse_cnt) {
623 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
624 *lru_p = p;
625 *lru_w = w;
626 *lru_l = w_l;
629 w_l = w;
633 static int unuse_one_window(struct packed_git *current)
635 struct packed_git *p, *lru_p = NULL;
636 struct pack_window *lru_w = NULL, *lru_l = NULL;
638 if (current)
639 scan_windows(current, &lru_p, &lru_w, &lru_l);
640 for (p = packed_git; p; p = p->next)
641 scan_windows(p, &lru_p, &lru_w, &lru_l);
642 if (lru_p) {
643 munmap(lru_w->base, lru_w->len);
644 pack_mapped -= lru_w->len;
645 if (lru_l)
646 lru_l->next = lru_w->next;
647 else
648 lru_p->windows = lru_w->next;
649 free(lru_w);
650 pack_open_windows--;
651 return 1;
653 return 0;
656 void release_pack_memory(size_t need)
658 size_t cur = pack_mapped;
659 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
660 ; /* nothing */
663 void *xmmap(void *start, size_t length,
664 int prot, int flags, int fd, off_t offset)
666 void *ret = mmap(start, length, prot, flags, fd, offset);
667 if (ret == MAP_FAILED) {
668 if (!length)
669 return NULL;
670 release_pack_memory(length);
671 ret = mmap(start, length, prot, flags, fd, offset);
672 if (ret == MAP_FAILED)
673 die_errno("Out of memory? mmap failed");
675 return ret;
678 void close_pack_windows(struct packed_git *p)
680 while (p->windows) {
681 struct pack_window *w = p->windows;
683 if (w->inuse_cnt)
684 die("pack '%s' still has open windows to it",
685 p->pack_name);
686 munmap(w->base, w->len);
687 pack_mapped -= w->len;
688 pack_open_windows--;
689 p->windows = w->next;
690 free(w);
695 * The LRU pack is the one with the oldest MRU window, preferring packs
696 * with no used windows, or the oldest mtime if it has no windows allocated.
698 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
700 struct pack_window *w, *this_mru_w;
701 int has_windows_inuse = 0;
704 * Reject this pack if it has windows and the previously selected
705 * one does not. If this pack does not have windows, reject
706 * it if the pack file is newer than the previously selected one.
708 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
709 return;
711 for (w = this_mru_w = p->windows; w; w = w->next) {
713 * Reject this pack if any of its windows are in use,
714 * but the previously selected pack did not have any
715 * inuse windows. Otherwise, record that this pack
716 * has windows in use.
718 if (w->inuse_cnt) {
719 if (*accept_windows_inuse)
720 has_windows_inuse = 1;
721 else
722 return;
725 if (w->last_used > this_mru_w->last_used)
726 this_mru_w = w;
729 * Reject this pack if it has windows that have been
730 * used more recently than the previously selected pack.
731 * If the previously selected pack had windows inuse and
732 * we have not encountered a window in this pack that is
733 * inuse, skip this check since we prefer a pack with no
734 * inuse windows to one that has inuse windows.
736 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
737 this_mru_w->last_used > (*mru_w)->last_used)
738 return;
742 * Select this pack.
744 *mru_w = this_mru_w;
745 *lru_p = p;
746 *accept_windows_inuse = has_windows_inuse;
749 static int close_one_pack(void)
751 struct packed_git *p, *lru_p = NULL;
752 struct pack_window *mru_w = NULL;
753 int accept_windows_inuse = 1;
755 for (p = packed_git; p; p = p->next) {
756 if (p->pack_fd == -1)
757 continue;
758 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
761 if (lru_p) {
762 close(lru_p->pack_fd);
763 pack_open_fds--;
764 lru_p->pack_fd = -1;
765 return 1;
768 return 0;
771 void unuse_pack(struct pack_window **w_cursor)
773 struct pack_window *w = *w_cursor;
774 if (w) {
775 w->inuse_cnt--;
776 *w_cursor = NULL;
780 void close_pack_index(struct packed_git *p)
782 if (p->index_data) {
783 munmap((void *)p->index_data, p->index_size);
784 p->index_data = NULL;
789 * This is used by git-repack in case a newly created pack happens to
790 * contain the same set of objects as an existing one. In that case
791 * the resulting file might be different even if its name would be the
792 * same. It is best to close any reference to the old pack before it is
793 * replaced on disk. Of course no index pointers nor windows for given pack
794 * must subsist at this point. If ever objects from this pack are requested
795 * again, the new version of the pack will be reinitialized through
796 * reprepare_packed_git().
798 void free_pack_by_name(const char *pack_name)
800 struct packed_git *p, **pp = &packed_git;
802 while (*pp) {
803 p = *pp;
804 if (strcmp(pack_name, p->pack_name) == 0) {
805 clear_delta_base_cache();
806 close_pack_windows(p);
807 if (p->pack_fd != -1) {
808 close(p->pack_fd);
809 pack_open_fds--;
811 close_pack_index(p);
812 free(p->bad_object_sha1);
813 *pp = p->next;
814 if (last_found_pack == p)
815 last_found_pack = NULL;
816 free(p);
817 return;
819 pp = &p->next;
823 static unsigned int get_max_fd_limit(void)
825 #ifdef RLIMIT_NOFILE
827 struct rlimit lim;
829 if (!getrlimit(RLIMIT_NOFILE, &lim))
830 return lim.rlim_cur;
832 #endif
834 #ifdef _SC_OPEN_MAX
836 long open_max = sysconf(_SC_OPEN_MAX);
837 if (0 < open_max)
838 return open_max;
840 * Otherwise, we got -1 for one of the two
841 * reasons:
843 * (1) sysconf() did not understand _SC_OPEN_MAX
844 * and signaled an error with -1; or
845 * (2) sysconf() said there is no limit.
847 * We _could_ clear errno before calling sysconf() to
848 * tell these two cases apart and return a huge number
849 * in the latter case to let the caller cap it to a
850 * value that is not so selfish, but letting the
851 * fallback OPEN_MAX codepath take care of these cases
852 * is a lot simpler.
855 #endif
857 #ifdef OPEN_MAX
858 return OPEN_MAX;
859 #else
860 return 1; /* see the caller ;-) */
861 #endif
865 * Do not call this directly as this leaks p->pack_fd on error return;
866 * call open_packed_git() instead.
868 static int open_packed_git_1(struct packed_git *p)
870 struct stat st;
871 struct pack_header hdr;
872 unsigned char sha1[20];
873 unsigned char *idx_sha1;
874 long fd_flag;
876 if (!p->index_data && open_pack_index(p))
877 return error("packfile %s index unavailable", p->pack_name);
879 if (!pack_max_fds) {
880 unsigned int max_fds = get_max_fd_limit();
882 /* Save 3 for stdin/stdout/stderr, 22 for work */
883 if (25 < max_fds)
884 pack_max_fds = max_fds - 25;
885 else
886 pack_max_fds = 1;
889 while (pack_max_fds <= pack_open_fds && close_one_pack())
890 ; /* nothing */
892 p->pack_fd = git_open_noatime(p->pack_name);
893 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
894 return -1;
895 pack_open_fds++;
897 /* If we created the struct before we had the pack we lack size. */
898 if (!p->pack_size) {
899 if (!S_ISREG(st.st_mode))
900 return error("packfile %s not a regular file", p->pack_name);
901 p->pack_size = st.st_size;
902 } else if (p->pack_size != st.st_size)
903 return error("packfile %s size changed", p->pack_name);
905 /* We leave these file descriptors open with sliding mmap;
906 * there is no point keeping them open across exec(), though.
908 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
909 if (fd_flag < 0)
910 return error("cannot determine file descriptor flags");
911 fd_flag |= FD_CLOEXEC;
912 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
913 return error("cannot set FD_CLOEXEC");
915 /* Verify we recognize this pack file format. */
916 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
917 return error("file %s is far too short to be a packfile", p->pack_name);
918 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
919 return error("file %s is not a GIT packfile", p->pack_name);
920 if (!pack_version_ok(hdr.hdr_version))
921 return error("packfile %s is version %"PRIu32" and not"
922 " supported (try upgrading GIT to a newer version)",
923 p->pack_name, ntohl(hdr.hdr_version));
925 /* Verify the pack matches its index. */
926 if (p->num_objects != ntohl(hdr.hdr_entries))
927 return error("packfile %s claims to have %"PRIu32" objects"
928 " while index indicates %"PRIu32" objects",
929 p->pack_name, ntohl(hdr.hdr_entries),
930 p->num_objects);
931 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
932 return error("end of packfile %s is unavailable", p->pack_name);
933 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
934 return error("packfile %s signature is unavailable", p->pack_name);
935 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
936 if (hashcmp(sha1, idx_sha1))
937 return error("packfile %s does not match index", p->pack_name);
938 return 0;
941 static int open_packed_git(struct packed_git *p)
943 if (!open_packed_git_1(p))
944 return 0;
945 if (p->pack_fd != -1) {
946 close(p->pack_fd);
947 pack_open_fds--;
948 p->pack_fd = -1;
950 return -1;
953 static int in_window(struct pack_window *win, off_t offset)
955 /* We must promise at least 20 bytes (one hash) after the
956 * offset is available from this window, otherwise the offset
957 * is not actually in this window and a different window (which
958 * has that one hash excess) must be used. This is to support
959 * the object header and delta base parsing routines below.
961 off_t win_off = win->offset;
962 return win_off <= offset
963 && (offset + 20) <= (win_off + win->len);
966 unsigned char *use_pack(struct packed_git *p,
967 struct pack_window **w_cursor,
968 off_t offset,
969 unsigned long *left)
971 struct pack_window *win = *w_cursor;
973 /* Since packfiles end in a hash of their content and it's
974 * pointless to ask for an offset into the middle of that
975 * hash, and the in_window function above wouldn't match
976 * don't allow an offset too close to the end of the file.
978 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
979 die("packfile %s cannot be accessed", p->pack_name);
980 if (offset > (p->pack_size - 20))
981 die("offset beyond end of packfile (truncated pack?)");
983 if (!win || !in_window(win, offset)) {
984 if (win)
985 win->inuse_cnt--;
986 for (win = p->windows; win; win = win->next) {
987 if (in_window(win, offset))
988 break;
990 if (!win) {
991 size_t window_align = packed_git_window_size / 2;
992 off_t len;
994 if (p->pack_fd == -1 && open_packed_git(p))
995 die("packfile %s cannot be accessed", p->pack_name);
997 win = xcalloc(1, sizeof(*win));
998 win->offset = (offset / window_align) * window_align;
999 len = p->pack_size - win->offset;
1000 if (len > packed_git_window_size)
1001 len = packed_git_window_size;
1002 win->len = (size_t)len;
1003 pack_mapped += win->len;
1004 while (packed_git_limit < pack_mapped
1005 && unuse_one_window(p))
1006 ; /* nothing */
1007 win->base = xmmap(NULL, win->len,
1008 PROT_READ, MAP_PRIVATE,
1009 p->pack_fd, win->offset);
1010 if (win->base == MAP_FAILED)
1011 die("packfile %s cannot be mapped: %s",
1012 p->pack_name,
1013 strerror(errno));
1014 if (!win->offset && win->len == p->pack_size
1015 && !p->do_not_close) {
1016 close(p->pack_fd);
1017 pack_open_fds--;
1018 p->pack_fd = -1;
1020 pack_mmap_calls++;
1021 pack_open_windows++;
1022 if (pack_mapped > peak_pack_mapped)
1023 peak_pack_mapped = pack_mapped;
1024 if (pack_open_windows > peak_pack_open_windows)
1025 peak_pack_open_windows = pack_open_windows;
1026 win->next = p->windows;
1027 p->windows = win;
1030 if (win != *w_cursor) {
1031 win->last_used = pack_used_ctr++;
1032 win->inuse_cnt++;
1033 *w_cursor = win;
1035 offset -= win->offset;
1036 if (left)
1037 *left = win->len - xsize_t(offset);
1038 return win->base + offset;
1041 static struct packed_git *alloc_packed_git(int extra)
1043 struct packed_git *p = xmalloc(sizeof(*p) + extra);
1044 memset(p, 0, sizeof(*p));
1045 p->pack_fd = -1;
1046 return p;
1049 static void try_to_free_pack_memory(size_t size)
1051 release_pack_memory(size);
1054 struct packed_git *add_packed_git(const char *path, int path_len, int local)
1056 static int have_set_try_to_free_routine;
1057 struct stat st;
1058 struct packed_git *p = alloc_packed_git(path_len + 2);
1060 if (!have_set_try_to_free_routine) {
1061 have_set_try_to_free_routine = 1;
1062 set_try_to_free_routine(try_to_free_pack_memory);
1066 * Make sure a corresponding .pack file exists and that
1067 * the index looks sane.
1069 path_len -= strlen(".idx");
1070 if (path_len < 1) {
1071 free(p);
1072 return NULL;
1074 memcpy(p->pack_name, path, path_len);
1076 strcpy(p->pack_name + path_len, ".keep");
1077 if (!access(p->pack_name, F_OK))
1078 p->pack_keep = 1;
1080 strcpy(p->pack_name + path_len, ".pack");
1081 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
1082 free(p);
1083 return NULL;
1086 /* ok, it looks sane as far as we can check without
1087 * actually mapping the pack file.
1089 p->pack_size = st.st_size;
1090 p->pack_local = local;
1091 p->mtime = st.st_mtime;
1092 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
1093 hashclr(p->sha1);
1094 return p;
1097 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
1099 const char *path = sha1_pack_name(sha1);
1100 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
1102 strcpy(p->pack_name, path);
1103 hashcpy(p->sha1, sha1);
1104 if (check_packed_git_idx(idx_path, p)) {
1105 free(p);
1106 return NULL;
1109 return p;
1112 void install_packed_git(struct packed_git *pack)
1114 if (pack->pack_fd != -1)
1115 pack_open_fds++;
1117 pack->next = packed_git;
1118 packed_git = pack;
1121 void (*report_garbage)(const char *desc, const char *path);
1123 static void report_helper(const struct string_list *list,
1124 int seen_bits, int first, int last)
1126 const char *msg;
1127 switch (seen_bits) {
1128 case 0:
1129 msg = "no corresponding .idx nor .pack";
1130 break;
1131 case 1:
1132 msg = "no corresponding .idx";
1133 break;
1134 case 2:
1135 msg = "no corresponding .pack";
1136 break;
1137 default:
1138 return;
1140 for (; first < last; first++)
1141 report_garbage(msg, list->items[first].string);
1144 static void report_pack_garbage(struct string_list *list)
1146 int i, baselen = -1, first = 0, seen_bits = 0;
1148 if (!report_garbage)
1149 return;
1151 sort_string_list(list);
1153 for (i = 0; i < list->nr; i++) {
1154 const char *path = list->items[i].string;
1155 if (baselen != -1 &&
1156 strncmp(path, list->items[first].string, baselen)) {
1157 report_helper(list, seen_bits, first, i);
1158 baselen = -1;
1159 seen_bits = 0;
1161 if (baselen == -1) {
1162 const char *dot = strrchr(path, '.');
1163 if (!dot) {
1164 report_garbage("garbage found", path);
1165 continue;
1167 baselen = dot - path + 1;
1168 first = i;
1170 if (!strcmp(path + baselen, "pack"))
1171 seen_bits |= 1;
1172 else if (!strcmp(path + baselen, "idx"))
1173 seen_bits |= 2;
1175 report_helper(list, seen_bits, first, list->nr);
1178 static void prepare_packed_git_one(char *objdir, int local)
1180 /* Ensure that this buffer is large enough so that we can
1181 append "/pack/" without clobbering the stack even if
1182 strlen(objdir) were PATH_MAX. */
1183 char path[PATH_MAX + 1 + 4 + 1 + 1];
1184 int len;
1185 DIR *dir;
1186 struct dirent *de;
1187 struct string_list garbage = STRING_LIST_INIT_DUP;
1189 sprintf(path, "%s/pack", objdir);
1190 len = strlen(path);
1191 dir = opendir(path);
1192 if (!dir) {
1193 if (errno != ENOENT)
1194 error("unable to open object pack directory: %s: %s",
1195 path, strerror(errno));
1196 return;
1198 path[len++] = '/';
1199 while ((de = readdir(dir)) != NULL) {
1200 int namelen = strlen(de->d_name);
1201 struct packed_git *p;
1203 if (len + namelen + 1 > sizeof(path)) {
1204 if (report_garbage) {
1205 struct strbuf sb = STRBUF_INIT;
1206 strbuf_addf(&sb, "%.*s/%s", len - 1, path, de->d_name);
1207 report_garbage("path too long", sb.buf);
1208 strbuf_release(&sb);
1210 continue;
1213 if (is_dot_or_dotdot(de->d_name))
1214 continue;
1216 strcpy(path + len, de->d_name);
1218 if (has_extension(de->d_name, ".idx")) {
1219 /* Don't reopen a pack we already have. */
1220 for (p = packed_git; p; p = p->next) {
1221 if (!memcmp(path, p->pack_name, len + namelen - 4))
1222 break;
1224 if (p == NULL &&
1226 * See if it really is a valid .idx file with
1227 * corresponding .pack file that we can map.
1229 (p = add_packed_git(path, len + namelen, local)) != NULL)
1230 install_packed_git(p);
1233 if (!report_garbage)
1234 continue;
1236 if (has_extension(de->d_name, ".idx") ||
1237 has_extension(de->d_name, ".pack") ||
1238 has_extension(de->d_name, ".bitmap") ||
1239 has_extension(de->d_name, ".keep"))
1240 string_list_append(&garbage, path);
1241 else
1242 report_garbage("garbage found", path);
1244 closedir(dir);
1245 report_pack_garbage(&garbage);
1246 string_list_clear(&garbage, 0);
1249 static int sort_pack(const void *a_, const void *b_)
1251 struct packed_git *a = *((struct packed_git **)a_);
1252 struct packed_git *b = *((struct packed_git **)b_);
1253 int st;
1256 * Local packs tend to contain objects specific to our
1257 * variant of the project than remote ones. In addition,
1258 * remote ones could be on a network mounted filesystem.
1259 * Favor local ones for these reasons.
1261 st = a->pack_local - b->pack_local;
1262 if (st)
1263 return -st;
1266 * Younger packs tend to contain more recent objects,
1267 * and more recent objects tend to get accessed more
1268 * often.
1270 if (a->mtime < b->mtime)
1271 return 1;
1272 else if (a->mtime == b->mtime)
1273 return 0;
1274 return -1;
1277 static void rearrange_packed_git(void)
1279 struct packed_git **ary, *p;
1280 int i, n;
1282 for (n = 0, p = packed_git; p; p = p->next)
1283 n++;
1284 if (n < 2)
1285 return;
1287 /* prepare an array of packed_git for easier sorting */
1288 ary = xcalloc(n, sizeof(struct packed_git *));
1289 for (n = 0, p = packed_git; p; p = p->next)
1290 ary[n++] = p;
1292 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1294 /* link them back again */
1295 for (i = 0; i < n - 1; i++)
1296 ary[i]->next = ary[i + 1];
1297 ary[n - 1]->next = NULL;
1298 packed_git = ary[0];
1300 free(ary);
1303 static int prepare_packed_git_run_once = 0;
1304 void prepare_packed_git(void)
1306 struct alternate_object_database *alt;
1308 if (prepare_packed_git_run_once)
1309 return;
1310 prepare_packed_git_one(get_object_directory(), 1);
1311 prepare_alt_odb();
1312 for (alt = alt_odb_list; alt; alt = alt->next) {
1313 alt->name[-1] = 0;
1314 prepare_packed_git_one(alt->base, 0);
1315 alt->name[-1] = '/';
1317 rearrange_packed_git();
1318 prepare_packed_git_run_once = 1;
1321 void reprepare_packed_git(void)
1323 prepare_packed_git_run_once = 0;
1324 prepare_packed_git();
1327 static void mark_bad_packed_object(struct packed_git *p,
1328 const unsigned char *sha1)
1330 unsigned i;
1331 for (i = 0; i < p->num_bad_objects; i++)
1332 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1333 return;
1334 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1335 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1336 p->num_bad_objects++;
1339 static const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1341 struct packed_git *p;
1342 unsigned i;
1344 for (p = packed_git; p; p = p->next)
1345 for (i = 0; i < p->num_bad_objects; i++)
1346 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1347 return p;
1348 return NULL;
1352 * With an in-core object data in "map", rehash it to make sure the
1353 * object name actually matches "sha1" to detect object corruption.
1354 * With "map" == NULL, try reading the object named with "sha1" using
1355 * the streaming interface and rehash it to do the same.
1357 int check_sha1_signature(const unsigned char *sha1, void *map,
1358 unsigned long size, const char *type)
1360 unsigned char real_sha1[20];
1361 enum object_type obj_type;
1362 struct git_istream *st;
1363 git_SHA_CTX c;
1364 char hdr[32];
1365 int hdrlen;
1367 if (map) {
1368 hash_sha1_file(map, size, type, real_sha1);
1369 return hashcmp(sha1, real_sha1) ? -1 : 0;
1372 st = open_istream(sha1, &obj_type, &size, NULL);
1373 if (!st)
1374 return -1;
1376 /* Generate the header */
1377 hdrlen = sprintf(hdr, "%s %lu", typename(obj_type), size) + 1;
1379 /* Sha1.. */
1380 git_SHA1_Init(&c);
1381 git_SHA1_Update(&c, hdr, hdrlen);
1382 for (;;) {
1383 char buf[1024 * 16];
1384 ssize_t readlen = read_istream(st, buf, sizeof(buf));
1386 if (readlen < 0) {
1387 close_istream(st);
1388 return -1;
1390 if (!readlen)
1391 break;
1392 git_SHA1_Update(&c, buf, readlen);
1394 git_SHA1_Final(real_sha1, &c);
1395 close_istream(st);
1396 return hashcmp(sha1, real_sha1) ? -1 : 0;
1399 int git_open_noatime(const char *name)
1401 static int sha1_file_open_flag = O_NOATIME;
1403 for (;;) {
1404 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1405 if (fd >= 0)
1406 return fd;
1408 /* Might the failure be due to O_NOATIME? */
1409 if (errno != ENOENT && sha1_file_open_flag) {
1410 sha1_file_open_flag = 0;
1411 continue;
1414 return -1;
1418 static int stat_sha1_file(const unsigned char *sha1, struct stat *st)
1420 struct alternate_object_database *alt;
1422 if (!lstat(sha1_file_name(sha1), st))
1423 return 0;
1425 prepare_alt_odb();
1426 errno = ENOENT;
1427 for (alt = alt_odb_list; alt; alt = alt->next) {
1428 fill_sha1_path(alt->name, sha1);
1429 if (!lstat(alt->base, st))
1430 return 0;
1433 return -1;
1436 static int open_sha1_file(const unsigned char *sha1)
1438 int fd;
1439 struct alternate_object_database *alt;
1441 fd = git_open_noatime(sha1_file_name(sha1));
1442 if (fd >= 0)
1443 return fd;
1445 prepare_alt_odb();
1446 errno = ENOENT;
1447 for (alt = alt_odb_list; alt; alt = alt->next) {
1448 fill_sha1_path(alt->name, sha1);
1449 fd = git_open_noatime(alt->base);
1450 if (fd >= 0)
1451 return fd;
1453 return -1;
1456 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1458 void *map;
1459 int fd;
1461 fd = open_sha1_file(sha1);
1462 map = NULL;
1463 if (fd >= 0) {
1464 struct stat st;
1466 if (!fstat(fd, &st)) {
1467 *size = xsize_t(st.st_size);
1468 if (!*size) {
1469 /* mmap() is forbidden on empty files */
1470 error("object file %s is empty", sha1_file_name(sha1));
1471 return NULL;
1473 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1475 close(fd);
1477 return map;
1480 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1481 unsigned long len, enum object_type *type, unsigned long *sizep)
1483 unsigned shift;
1484 unsigned long size, c;
1485 unsigned long used = 0;
1487 c = buf[used++];
1488 *type = (c >> 4) & 7;
1489 size = c & 15;
1490 shift = 4;
1491 while (c & 0x80) {
1492 if (len <= used || bitsizeof(long) <= shift) {
1493 error("bad object header");
1494 size = used = 0;
1495 break;
1497 c = buf[used++];
1498 size += (c & 0x7f) << shift;
1499 shift += 7;
1501 *sizep = size;
1502 return used;
1505 int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1507 /* Get the data stream */
1508 memset(stream, 0, sizeof(*stream));
1509 stream->next_in = map;
1510 stream->avail_in = mapsize;
1511 stream->next_out = buffer;
1512 stream->avail_out = bufsiz;
1514 git_inflate_init(stream);
1515 return git_inflate(stream, 0);
1518 static void *unpack_sha1_rest(git_zstream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1520 int bytes = strlen(buffer) + 1;
1521 unsigned char *buf = xmallocz(size);
1522 unsigned long n;
1523 int status = Z_OK;
1525 n = stream->total_out - bytes;
1526 if (n > size)
1527 n = size;
1528 memcpy(buf, (char *) buffer + bytes, n);
1529 bytes = n;
1530 if (bytes <= size) {
1532 * The above condition must be (bytes <= size), not
1533 * (bytes < size). In other words, even though we
1534 * expect no more output and set avail_out to zero,
1535 * the input zlib stream may have bytes that express
1536 * "this concludes the stream", and we *do* want to
1537 * eat that input.
1539 * Otherwise we would not be able to test that we
1540 * consumed all the input to reach the expected size;
1541 * we also want to check that zlib tells us that all
1542 * went well with status == Z_STREAM_END at the end.
1544 stream->next_out = buf + bytes;
1545 stream->avail_out = size - bytes;
1546 while (status == Z_OK)
1547 status = git_inflate(stream, Z_FINISH);
1549 if (status == Z_STREAM_END && !stream->avail_in) {
1550 git_inflate_end(stream);
1551 return buf;
1554 if (status < 0)
1555 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1556 else if (stream->avail_in)
1557 error("garbage at end of loose object '%s'",
1558 sha1_to_hex(sha1));
1559 free(buf);
1560 return NULL;
1564 * We used to just use "sscanf()", but that's actually way
1565 * too permissive for what we want to check. So do an anal
1566 * object header parse by hand.
1568 int parse_sha1_header(const char *hdr, unsigned long *sizep)
1570 char type[10];
1571 int i;
1572 unsigned long size;
1575 * The type can be at most ten bytes (including the
1576 * terminating '\0' that we add), and is followed by
1577 * a space.
1579 i = 0;
1580 for (;;) {
1581 char c = *hdr++;
1582 if (c == ' ')
1583 break;
1584 type[i++] = c;
1585 if (i >= sizeof(type))
1586 return -1;
1588 type[i] = 0;
1591 * The length must follow immediately, and be in canonical
1592 * decimal format (ie "010" is not valid).
1594 size = *hdr++ - '0';
1595 if (size > 9)
1596 return -1;
1597 if (size) {
1598 for (;;) {
1599 unsigned long c = *hdr - '0';
1600 if (c > 9)
1601 break;
1602 hdr++;
1603 size = size * 10 + c;
1606 *sizep = size;
1609 * The length must be followed by a zero byte
1611 return *hdr ? -1 : type_from_string(type);
1614 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1616 int ret;
1617 git_zstream stream;
1618 char hdr[8192];
1620 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1621 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1622 return NULL;
1624 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1627 unsigned long get_size_from_delta(struct packed_git *p,
1628 struct pack_window **w_curs,
1629 off_t curpos)
1631 const unsigned char *data;
1632 unsigned char delta_head[20], *in;
1633 git_zstream stream;
1634 int st;
1636 memset(&stream, 0, sizeof(stream));
1637 stream.next_out = delta_head;
1638 stream.avail_out = sizeof(delta_head);
1640 git_inflate_init(&stream);
1641 do {
1642 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1643 stream.next_in = in;
1644 st = git_inflate(&stream, Z_FINISH);
1645 curpos += stream.next_in - in;
1646 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1647 stream.total_out < sizeof(delta_head));
1648 git_inflate_end(&stream);
1649 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1650 error("delta data unpack-initial failed");
1651 return 0;
1654 /* Examine the initial part of the delta to figure out
1655 * the result size.
1657 data = delta_head;
1659 /* ignore base size */
1660 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1662 /* Read the result size */
1663 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1666 static off_t get_delta_base(struct packed_git *p,
1667 struct pack_window **w_curs,
1668 off_t *curpos,
1669 enum object_type type,
1670 off_t delta_obj_offset)
1672 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1673 off_t base_offset;
1675 /* use_pack() assured us we have [base_info, base_info + 20)
1676 * as a range that we can look at without walking off the
1677 * end of the mapped window. Its actually the hash size
1678 * that is assured. An OFS_DELTA longer than the hash size
1679 * is stupid, as then a REF_DELTA would be smaller to store.
1681 if (type == OBJ_OFS_DELTA) {
1682 unsigned used = 0;
1683 unsigned char c = base_info[used++];
1684 base_offset = c & 127;
1685 while (c & 128) {
1686 base_offset += 1;
1687 if (!base_offset || MSB(base_offset, 7))
1688 return 0; /* overflow */
1689 c = base_info[used++];
1690 base_offset = (base_offset << 7) + (c & 127);
1692 base_offset = delta_obj_offset - base_offset;
1693 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1694 return 0; /* out of bound */
1695 *curpos += used;
1696 } else if (type == OBJ_REF_DELTA) {
1697 /* The base entry _must_ be in the same pack */
1698 base_offset = find_pack_entry_one(base_info, p);
1699 *curpos += 20;
1700 } else
1701 die("I am totally screwed");
1702 return base_offset;
1706 * Like get_delta_base above, but we return the sha1 instead of the pack
1707 * offset. This means it is cheaper for REF deltas (we do not have to do
1708 * the final object lookup), but more expensive for OFS deltas (we
1709 * have to load the revidx to convert the offset back into a sha1).
1711 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1712 struct pack_window **w_curs,
1713 off_t curpos,
1714 enum object_type type,
1715 off_t delta_obj_offset)
1717 if (type == OBJ_REF_DELTA) {
1718 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1719 return base;
1720 } else if (type == OBJ_OFS_DELTA) {
1721 struct revindex_entry *revidx;
1722 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1723 type, delta_obj_offset);
1725 if (!base_offset)
1726 return NULL;
1728 revidx = find_pack_revindex(p, base_offset);
1729 if (!revidx)
1730 return NULL;
1732 return nth_packed_object_sha1(p, revidx->nr);
1733 } else
1734 return NULL;
1737 int unpack_object_header(struct packed_git *p,
1738 struct pack_window **w_curs,
1739 off_t *curpos,
1740 unsigned long *sizep)
1742 unsigned char *base;
1743 unsigned long left;
1744 unsigned long used;
1745 enum object_type type;
1747 /* use_pack() assures us we have [base, base + 20) available
1748 * as a range that we can look at. (Its actually the hash
1749 * size that is assured.) With our object header encoding
1750 * the maximum deflated object size is 2^137, which is just
1751 * insane, so we know won't exceed what we have been given.
1753 base = use_pack(p, w_curs, *curpos, &left);
1754 used = unpack_object_header_buffer(base, left, &type, sizep);
1755 if (!used) {
1756 type = OBJ_BAD;
1757 } else
1758 *curpos += used;
1760 return type;
1763 static int retry_bad_packed_offset(struct packed_git *p, off_t obj_offset)
1765 int type;
1766 struct revindex_entry *revidx;
1767 const unsigned char *sha1;
1768 revidx = find_pack_revindex(p, obj_offset);
1769 if (!revidx)
1770 return OBJ_BAD;
1771 sha1 = nth_packed_object_sha1(p, revidx->nr);
1772 mark_bad_packed_object(p, sha1);
1773 type = sha1_object_info(sha1, NULL);
1774 if (type <= OBJ_NONE)
1775 return OBJ_BAD;
1776 return type;
1779 #define POI_STACK_PREALLOC 64
1781 static enum object_type packed_to_object_type(struct packed_git *p,
1782 off_t obj_offset,
1783 enum object_type type,
1784 struct pack_window **w_curs,
1785 off_t curpos)
1787 off_t small_poi_stack[POI_STACK_PREALLOC];
1788 off_t *poi_stack = small_poi_stack;
1789 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1791 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1792 off_t base_offset;
1793 unsigned long size;
1794 /* Push the object we're going to leave behind */
1795 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1796 poi_stack_alloc = alloc_nr(poi_stack_nr);
1797 poi_stack = xmalloc(sizeof(off_t)*poi_stack_alloc);
1798 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1799 } else {
1800 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1802 poi_stack[poi_stack_nr++] = obj_offset;
1803 /* If parsing the base offset fails, just unwind */
1804 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1805 if (!base_offset)
1806 goto unwind;
1807 curpos = obj_offset = base_offset;
1808 type = unpack_object_header(p, w_curs, &curpos, &size);
1809 if (type <= OBJ_NONE) {
1810 /* If getting the base itself fails, we first
1811 * retry the base, otherwise unwind */
1812 type = retry_bad_packed_offset(p, base_offset);
1813 if (type > OBJ_NONE)
1814 goto out;
1815 goto unwind;
1819 switch (type) {
1820 case OBJ_BAD:
1821 case OBJ_COMMIT:
1822 case OBJ_TREE:
1823 case OBJ_BLOB:
1824 case OBJ_TAG:
1825 break;
1826 default:
1827 error("unknown object type %i at offset %"PRIuMAX" in %s",
1828 type, (uintmax_t)obj_offset, p->pack_name);
1829 type = OBJ_BAD;
1832 out:
1833 if (poi_stack != small_poi_stack)
1834 free(poi_stack);
1835 return type;
1837 unwind:
1838 while (poi_stack_nr) {
1839 obj_offset = poi_stack[--poi_stack_nr];
1840 type = retry_bad_packed_offset(p, obj_offset);
1841 if (type > OBJ_NONE)
1842 goto out;
1844 type = OBJ_BAD;
1845 goto out;
1848 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1849 struct object_info *oi)
1851 struct pack_window *w_curs = NULL;
1852 unsigned long size;
1853 off_t curpos = obj_offset;
1854 enum object_type type;
1857 * We always get the representation type, but only convert it to
1858 * a "real" type later if the caller is interested.
1860 type = unpack_object_header(p, &w_curs, &curpos, &size);
1862 if (oi->sizep) {
1863 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1864 off_t tmp_pos = curpos;
1865 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1866 type, obj_offset);
1867 if (!base_offset) {
1868 type = OBJ_BAD;
1869 goto out;
1871 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1872 if (*oi->sizep == 0) {
1873 type = OBJ_BAD;
1874 goto out;
1876 } else {
1877 *oi->sizep = size;
1881 if (oi->disk_sizep) {
1882 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1883 *oi->disk_sizep = revidx[1].offset - obj_offset;
1886 if (oi->typep) {
1887 *oi->typep = packed_to_object_type(p, obj_offset, type, &w_curs, curpos);
1888 if (*oi->typep < 0) {
1889 type = OBJ_BAD;
1890 goto out;
1894 if (oi->delta_base_sha1) {
1895 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1896 const unsigned char *base;
1898 base = get_delta_base_sha1(p, &w_curs, curpos,
1899 type, obj_offset);
1900 if (!base) {
1901 type = OBJ_BAD;
1902 goto out;
1905 hashcpy(oi->delta_base_sha1, base);
1906 } else
1907 hashclr(oi->delta_base_sha1);
1910 out:
1911 unuse_pack(&w_curs);
1912 return type;
1915 static void *unpack_compressed_entry(struct packed_git *p,
1916 struct pack_window **w_curs,
1917 off_t curpos,
1918 unsigned long size)
1920 int st;
1921 git_zstream stream;
1922 unsigned char *buffer, *in;
1924 buffer = xmallocz(size);
1925 memset(&stream, 0, sizeof(stream));
1926 stream.next_out = buffer;
1927 stream.avail_out = size + 1;
1929 git_inflate_init(&stream);
1930 do {
1931 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1932 stream.next_in = in;
1933 st = git_inflate(&stream, Z_FINISH);
1934 if (!stream.avail_out)
1935 break; /* the payload is larger than it should be */
1936 curpos += stream.next_in - in;
1937 } while (st == Z_OK || st == Z_BUF_ERROR);
1938 git_inflate_end(&stream);
1939 if ((st != Z_STREAM_END) || stream.total_out != size) {
1940 free(buffer);
1941 return NULL;
1944 return buffer;
1947 #define MAX_DELTA_CACHE (256)
1949 static size_t delta_base_cached;
1951 static struct delta_base_cache_lru_list {
1952 struct delta_base_cache_lru_list *prev;
1953 struct delta_base_cache_lru_list *next;
1954 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1956 static struct delta_base_cache_entry {
1957 struct delta_base_cache_lru_list lru;
1958 void *data;
1959 struct packed_git *p;
1960 off_t base_offset;
1961 unsigned long size;
1962 enum object_type type;
1963 } delta_base_cache[MAX_DELTA_CACHE];
1965 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1967 unsigned long hash;
1969 hash = (unsigned long)p + (unsigned long)base_offset;
1970 hash += (hash >> 8) + (hash >> 16);
1971 return hash % MAX_DELTA_CACHE;
1974 static struct delta_base_cache_entry *
1975 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1977 unsigned long hash = pack_entry_hash(p, base_offset);
1978 return delta_base_cache + hash;
1981 static int eq_delta_base_cache_entry(struct delta_base_cache_entry *ent,
1982 struct packed_git *p, off_t base_offset)
1984 return (ent->data && ent->p == p && ent->base_offset == base_offset);
1987 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1989 struct delta_base_cache_entry *ent;
1990 ent = get_delta_base_cache_entry(p, base_offset);
1991 return eq_delta_base_cache_entry(ent, p, base_offset);
1994 static void clear_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1996 ent->data = NULL;
1997 ent->lru.next->prev = ent->lru.prev;
1998 ent->lru.prev->next = ent->lru.next;
1999 delta_base_cached -= ent->size;
2002 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
2003 unsigned long *base_size, enum object_type *type, int keep_cache)
2005 struct delta_base_cache_entry *ent;
2006 void *ret;
2008 ent = get_delta_base_cache_entry(p, base_offset);
2010 if (!eq_delta_base_cache_entry(ent, p, base_offset))
2011 return unpack_entry(p, base_offset, type, base_size);
2013 ret = ent->data;
2015 if (!keep_cache)
2016 clear_delta_base_cache_entry(ent);
2017 else
2018 ret = xmemdupz(ent->data, ent->size);
2019 *type = ent->type;
2020 *base_size = ent->size;
2021 return ret;
2024 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
2026 if (ent->data) {
2027 free(ent->data);
2028 ent->data = NULL;
2029 ent->lru.next->prev = ent->lru.prev;
2030 ent->lru.prev->next = ent->lru.next;
2031 delta_base_cached -= ent->size;
2035 void clear_delta_base_cache(void)
2037 unsigned long p;
2038 for (p = 0; p < MAX_DELTA_CACHE; p++)
2039 release_delta_base_cache(&delta_base_cache[p]);
2042 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
2043 void *base, unsigned long base_size, enum object_type type)
2045 unsigned long hash = pack_entry_hash(p, base_offset);
2046 struct delta_base_cache_entry *ent = delta_base_cache + hash;
2047 struct delta_base_cache_lru_list *lru;
2049 release_delta_base_cache(ent);
2050 delta_base_cached += base_size;
2052 for (lru = delta_base_cache_lru.next;
2053 delta_base_cached > delta_base_cache_limit
2054 && lru != &delta_base_cache_lru;
2055 lru = lru->next) {
2056 struct delta_base_cache_entry *f = (void *)lru;
2057 if (f->type == OBJ_BLOB)
2058 release_delta_base_cache(f);
2060 for (lru = delta_base_cache_lru.next;
2061 delta_base_cached > delta_base_cache_limit
2062 && lru != &delta_base_cache_lru;
2063 lru = lru->next) {
2064 struct delta_base_cache_entry *f = (void *)lru;
2065 release_delta_base_cache(f);
2068 ent->p = p;
2069 ent->base_offset = base_offset;
2070 ent->type = type;
2071 ent->data = base;
2072 ent->size = base_size;
2073 ent->lru.next = &delta_base_cache_lru;
2074 ent->lru.prev = delta_base_cache_lru.prev;
2075 delta_base_cache_lru.prev->next = &ent->lru;
2076 delta_base_cache_lru.prev = &ent->lru;
2079 static void *read_object(const unsigned char *sha1, enum object_type *type,
2080 unsigned long *size);
2082 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
2084 static FILE *log_file;
2086 if (!log_pack_access)
2087 log_pack_access = getenv("GIT_TRACE_PACK_ACCESS");
2088 if (!log_pack_access)
2089 log_pack_access = no_log_pack_access;
2090 if (log_pack_access == no_log_pack_access)
2091 return;
2093 if (!log_file) {
2094 log_file = fopen(log_pack_access, "w");
2095 if (!log_file) {
2096 error("cannot open pack access log '%s' for writing: %s",
2097 log_pack_access, strerror(errno));
2098 log_pack_access = no_log_pack_access;
2099 return;
2102 fprintf(log_file, "%s %"PRIuMAX"\n",
2103 p->pack_name, (uintmax_t)obj_offset);
2104 fflush(log_file);
2107 int do_check_packed_object_crc;
2109 #define UNPACK_ENTRY_STACK_PREALLOC 64
2110 struct unpack_entry_stack_ent {
2111 off_t obj_offset;
2112 off_t curpos;
2113 unsigned long size;
2116 void *unpack_entry(struct packed_git *p, off_t obj_offset,
2117 enum object_type *final_type, unsigned long *final_size)
2119 struct pack_window *w_curs = NULL;
2120 off_t curpos = obj_offset;
2121 void *data = NULL;
2122 unsigned long size;
2123 enum object_type type;
2124 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
2125 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
2126 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
2127 int base_from_cache = 0;
2129 if (log_pack_access != no_log_pack_access)
2130 write_pack_access_log(p, obj_offset);
2132 /* PHASE 1: drill down to the innermost base object */
2133 for (;;) {
2134 off_t base_offset;
2135 int i;
2136 struct delta_base_cache_entry *ent;
2138 ent = get_delta_base_cache_entry(p, curpos);
2139 if (eq_delta_base_cache_entry(ent, p, curpos)) {
2140 type = ent->type;
2141 data = ent->data;
2142 size = ent->size;
2143 clear_delta_base_cache_entry(ent);
2144 base_from_cache = 1;
2145 break;
2148 if (do_check_packed_object_crc && p->index_version > 1) {
2149 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
2150 unsigned long len = revidx[1].offset - obj_offset;
2151 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
2152 const unsigned char *sha1 =
2153 nth_packed_object_sha1(p, revidx->nr);
2154 error("bad packed object CRC for %s",
2155 sha1_to_hex(sha1));
2156 mark_bad_packed_object(p, sha1);
2157 unuse_pack(&w_curs);
2158 return NULL;
2162 type = unpack_object_header(p, &w_curs, &curpos, &size);
2163 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
2164 break;
2166 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
2167 if (!base_offset) {
2168 error("failed to validate delta base reference "
2169 "at offset %"PRIuMAX" from %s",
2170 (uintmax_t)curpos, p->pack_name);
2171 /* bail to phase 2, in hopes of recovery */
2172 data = NULL;
2173 break;
2176 /* push object, proceed to base */
2177 if (delta_stack_nr >= delta_stack_alloc
2178 && delta_stack == small_delta_stack) {
2179 delta_stack_alloc = alloc_nr(delta_stack_nr);
2180 delta_stack = xmalloc(sizeof(*delta_stack)*delta_stack_alloc);
2181 memcpy(delta_stack, small_delta_stack,
2182 sizeof(*delta_stack)*delta_stack_nr);
2183 } else {
2184 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
2186 i = delta_stack_nr++;
2187 delta_stack[i].obj_offset = obj_offset;
2188 delta_stack[i].curpos = curpos;
2189 delta_stack[i].size = size;
2191 curpos = obj_offset = base_offset;
2194 /* PHASE 2: handle the base */
2195 switch (type) {
2196 case OBJ_OFS_DELTA:
2197 case OBJ_REF_DELTA:
2198 if (data)
2199 die("BUG in unpack_entry: left loop at a valid delta");
2200 break;
2201 case OBJ_COMMIT:
2202 case OBJ_TREE:
2203 case OBJ_BLOB:
2204 case OBJ_TAG:
2205 if (!base_from_cache)
2206 data = unpack_compressed_entry(p, &w_curs, curpos, size);
2207 break;
2208 default:
2209 data = NULL;
2210 error("unknown object type %i at offset %"PRIuMAX" in %s",
2211 type, (uintmax_t)obj_offset, p->pack_name);
2214 /* PHASE 3: apply deltas in order */
2216 /* invariants:
2217 * 'data' holds the base data, or NULL if there was corruption
2219 while (delta_stack_nr) {
2220 void *delta_data;
2221 void *base = data;
2222 unsigned long delta_size, base_size = size;
2223 int i;
2225 data = NULL;
2227 if (base)
2228 add_delta_base_cache(p, obj_offset, base, base_size, type);
2230 if (!base) {
2232 * We're probably in deep shit, but let's try to fetch
2233 * the required base anyway from another pack or loose.
2234 * This is costly but should happen only in the presence
2235 * of a corrupted pack, and is better than failing outright.
2237 struct revindex_entry *revidx;
2238 const unsigned char *base_sha1;
2239 revidx = find_pack_revindex(p, obj_offset);
2240 if (revidx) {
2241 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
2242 error("failed to read delta base object %s"
2243 " at offset %"PRIuMAX" from %s",
2244 sha1_to_hex(base_sha1), (uintmax_t)obj_offset,
2245 p->pack_name);
2246 mark_bad_packed_object(p, base_sha1);
2247 base = read_object(base_sha1, &type, &base_size);
2251 i = --delta_stack_nr;
2252 obj_offset = delta_stack[i].obj_offset;
2253 curpos = delta_stack[i].curpos;
2254 delta_size = delta_stack[i].size;
2256 if (!base)
2257 continue;
2259 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
2261 if (!delta_data) {
2262 error("failed to unpack compressed delta "
2263 "at offset %"PRIuMAX" from %s",
2264 (uintmax_t)curpos, p->pack_name);
2265 data = NULL;
2266 continue;
2269 data = patch_delta(base, base_size,
2270 delta_data, delta_size,
2271 &size);
2274 * We could not apply the delta; warn the user, but keep going.
2275 * Our failure will be noticed either in the next iteration of
2276 * the loop, or if this is the final delta, in the caller when
2277 * we return NULL. Those code paths will take care of making
2278 * a more explicit warning and retrying with another copy of
2279 * the object.
2281 if (!data)
2282 error("failed to apply delta");
2284 free(delta_data);
2287 *final_type = type;
2288 *final_size = size;
2290 unuse_pack(&w_curs);
2292 if (delta_stack != small_delta_stack)
2293 free(delta_stack);
2295 return data;
2298 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
2299 uint32_t n)
2301 const unsigned char *index = p->index_data;
2302 if (!index) {
2303 if (open_pack_index(p))
2304 return NULL;
2305 index = p->index_data;
2307 if (n >= p->num_objects)
2308 return NULL;
2309 index += 4 * 256;
2310 if (p->index_version == 1) {
2311 return index + 24 * n + 4;
2312 } else {
2313 index += 8;
2314 return index + 20 * n;
2318 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
2320 const unsigned char *index = p->index_data;
2321 index += 4 * 256;
2322 if (p->index_version == 1) {
2323 return ntohl(*((uint32_t *)(index + 24 * n)));
2324 } else {
2325 uint32_t off;
2326 index += 8 + p->num_objects * (20 + 4);
2327 off = ntohl(*((uint32_t *)(index + 4 * n)));
2328 if (!(off & 0x80000000))
2329 return off;
2330 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
2331 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
2332 ntohl(*((uint32_t *)(index + 4)));
2336 off_t find_pack_entry_one(const unsigned char *sha1,
2337 struct packed_git *p)
2339 const uint32_t *level1_ofs = p->index_data;
2340 const unsigned char *index = p->index_data;
2341 unsigned hi, lo, stride;
2342 static int use_lookup = -1;
2343 static int debug_lookup = -1;
2345 if (debug_lookup < 0)
2346 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
2348 if (!index) {
2349 if (open_pack_index(p))
2350 return 0;
2351 level1_ofs = p->index_data;
2352 index = p->index_data;
2354 if (p->index_version > 1) {
2355 level1_ofs += 2;
2356 index += 8;
2358 index += 4 * 256;
2359 hi = ntohl(level1_ofs[*sha1]);
2360 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
2361 if (p->index_version > 1) {
2362 stride = 20;
2363 } else {
2364 stride = 24;
2365 index += 4;
2368 if (debug_lookup)
2369 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
2370 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
2372 if (use_lookup < 0)
2373 use_lookup = !!getenv("GIT_USE_LOOKUP");
2374 if (use_lookup) {
2375 int pos = sha1_entry_pos(index, stride, 0,
2376 lo, hi, p->num_objects, sha1);
2377 if (pos < 0)
2378 return 0;
2379 return nth_packed_object_offset(p, pos);
2382 do {
2383 unsigned mi = (lo + hi) / 2;
2384 int cmp = hashcmp(index + mi * stride, sha1);
2386 if (debug_lookup)
2387 printf("lo %u hi %u rg %u mi %u\n",
2388 lo, hi, hi - lo, mi);
2389 if (!cmp)
2390 return nth_packed_object_offset(p, mi);
2391 if (cmp > 0)
2392 hi = mi;
2393 else
2394 lo = mi+1;
2395 } while (lo < hi);
2396 return 0;
2399 int is_pack_valid(struct packed_git *p)
2401 /* An already open pack is known to be valid. */
2402 if (p->pack_fd != -1)
2403 return 1;
2405 /* If the pack has one window completely covering the
2406 * file size, the pack is known to be valid even if
2407 * the descriptor is not currently open.
2409 if (p->windows) {
2410 struct pack_window *w = p->windows;
2412 if (!w->offset && w->len == p->pack_size)
2413 return 1;
2416 /* Force the pack to open to prove its valid. */
2417 return !open_packed_git(p);
2420 static int fill_pack_entry(const unsigned char *sha1,
2421 struct pack_entry *e,
2422 struct packed_git *p)
2424 off_t offset;
2426 if (p->num_bad_objects) {
2427 unsigned i;
2428 for (i = 0; i < p->num_bad_objects; i++)
2429 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
2430 return 0;
2433 offset = find_pack_entry_one(sha1, p);
2434 if (!offset)
2435 return 0;
2438 * We are about to tell the caller where they can locate the
2439 * requested object. We better make sure the packfile is
2440 * still here and can be accessed before supplying that
2441 * answer, as it may have been deleted since the index was
2442 * loaded!
2444 if (!is_pack_valid(p)) {
2445 warning("packfile %s cannot be accessed", p->pack_name);
2446 return 0;
2448 e->offset = offset;
2449 e->p = p;
2450 hashcpy(e->sha1, sha1);
2451 return 1;
2455 * Iff a pack file contains the object named by sha1, return true and
2456 * store its location to e.
2458 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
2460 struct packed_git *p;
2462 prepare_packed_git();
2463 if (!packed_git)
2464 return 0;
2466 if (last_found_pack && fill_pack_entry(sha1, e, last_found_pack))
2467 return 1;
2469 for (p = packed_git; p; p = p->next) {
2470 if (p == last_found_pack)
2471 continue; /* we already checked this one */
2473 if (fill_pack_entry(sha1, e, p)) {
2474 last_found_pack = p;
2475 return 1;
2478 return 0;
2481 struct packed_git *find_sha1_pack(const unsigned char *sha1,
2482 struct packed_git *packs)
2484 struct packed_git *p;
2486 for (p = packs; p; p = p->next) {
2487 if (find_pack_entry_one(sha1, p))
2488 return p;
2490 return NULL;
2494 static int sha1_loose_object_info(const unsigned char *sha1,
2495 struct object_info *oi)
2497 int status;
2498 unsigned long mapsize, size;
2499 void *map;
2500 git_zstream stream;
2501 char hdr[32];
2503 if (oi->delta_base_sha1)
2504 hashclr(oi->delta_base_sha1);
2507 * If we don't care about type or size, then we don't
2508 * need to look inside the object at all. Note that we
2509 * do not optimize out the stat call, even if the
2510 * caller doesn't care about the disk-size, since our
2511 * return value implicitly indicates whether the
2512 * object even exists.
2514 if (!oi->typep && !oi->sizep) {
2515 struct stat st;
2516 if (stat_sha1_file(sha1, &st) < 0)
2517 return -1;
2518 if (oi->disk_sizep)
2519 *oi->disk_sizep = st.st_size;
2520 return 0;
2523 map = map_sha1_file(sha1, &mapsize);
2524 if (!map)
2525 return -1;
2526 if (oi->disk_sizep)
2527 *oi->disk_sizep = mapsize;
2528 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2529 status = error("unable to unpack %s header",
2530 sha1_to_hex(sha1));
2531 else if ((status = parse_sha1_header(hdr, &size)) < 0)
2532 status = error("unable to parse %s header", sha1_to_hex(sha1));
2533 else if (oi->sizep)
2534 *oi->sizep = size;
2535 git_inflate_end(&stream);
2536 munmap(map, mapsize);
2537 if (oi->typep)
2538 *oi->typep = status;
2539 return 0;
2542 int sha1_object_info_extended(const unsigned char *sha1, struct object_info *oi, unsigned flags)
2544 struct cached_object *co;
2545 struct pack_entry e;
2546 int rtype;
2547 const unsigned char *real = lookup_replace_object_extended(sha1, flags);
2549 co = find_cached_object(real);
2550 if (co) {
2551 if (oi->typep)
2552 *(oi->typep) = co->type;
2553 if (oi->sizep)
2554 *(oi->sizep) = co->size;
2555 if (oi->disk_sizep)
2556 *(oi->disk_sizep) = 0;
2557 if (oi->delta_base_sha1)
2558 hashclr(oi->delta_base_sha1);
2559 oi->whence = OI_CACHED;
2560 return 0;
2563 if (!find_pack_entry(real, &e)) {
2564 /* Most likely it's a loose object. */
2565 if (!sha1_loose_object_info(real, oi)) {
2566 oi->whence = OI_LOOSE;
2567 return 0;
2570 /* Not a loose object; someone else may have just packed it. */
2571 reprepare_packed_git();
2572 if (!find_pack_entry(real, &e))
2573 return -1;
2576 rtype = packed_object_info(e.p, e.offset, oi);
2577 if (rtype < 0) {
2578 mark_bad_packed_object(e.p, real);
2579 return sha1_object_info_extended(real, oi, 0);
2580 } else if (in_delta_base_cache(e.p, e.offset)) {
2581 oi->whence = OI_DBCACHED;
2582 } else {
2583 oi->whence = OI_PACKED;
2584 oi->u.packed.offset = e.offset;
2585 oi->u.packed.pack = e.p;
2586 oi->u.packed.is_delta = (rtype == OBJ_REF_DELTA ||
2587 rtype == OBJ_OFS_DELTA);
2590 return 0;
2593 /* returns enum object_type or negative */
2594 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2596 enum object_type type;
2597 struct object_info oi = {NULL};
2599 oi.typep = &type;
2600 oi.sizep = sizep;
2601 if (sha1_object_info_extended(sha1, &oi, LOOKUP_REPLACE_OBJECT) < 0)
2602 return -1;
2603 return type;
2606 static void *read_packed_sha1(const unsigned char *sha1,
2607 enum object_type *type, unsigned long *size)
2609 struct pack_entry e;
2610 void *data;
2612 if (!find_pack_entry(sha1, &e))
2613 return NULL;
2614 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2615 if (!data) {
2617 * We're probably in deep shit, but let's try to fetch
2618 * the required object anyway from another pack or loose.
2619 * This should happen only in the presence of a corrupted
2620 * pack, and is better than failing outright.
2622 error("failed to read object %s at offset %"PRIuMAX" from %s",
2623 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2624 mark_bad_packed_object(e.p, sha1);
2625 data = read_object(sha1, type, size);
2627 return data;
2630 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2631 unsigned char *sha1)
2633 struct cached_object *co;
2635 hash_sha1_file(buf, len, typename(type), sha1);
2636 if (has_sha1_file(sha1) || find_cached_object(sha1))
2637 return 0;
2638 ALLOC_GROW(cached_objects, cached_object_nr + 1, cached_object_alloc);
2639 co = &cached_objects[cached_object_nr++];
2640 co->size = len;
2641 co->type = type;
2642 co->buf = xmalloc(len);
2643 memcpy(co->buf, buf, len);
2644 hashcpy(co->sha1, sha1);
2645 return 0;
2648 static void *read_object(const unsigned char *sha1, enum object_type *type,
2649 unsigned long *size)
2651 unsigned long mapsize;
2652 void *map, *buf;
2653 struct cached_object *co;
2655 co = find_cached_object(sha1);
2656 if (co) {
2657 *type = co->type;
2658 *size = co->size;
2659 return xmemdupz(co->buf, co->size);
2662 buf = read_packed_sha1(sha1, type, size);
2663 if (buf)
2664 return buf;
2665 map = map_sha1_file(sha1, &mapsize);
2666 if (map) {
2667 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2668 munmap(map, mapsize);
2669 return buf;
2671 reprepare_packed_git();
2672 return read_packed_sha1(sha1, type, size);
2676 * This function dies on corrupt objects; the callers who want to
2677 * deal with them should arrange to call read_object() and give error
2678 * messages themselves.
2680 void *read_sha1_file_extended(const unsigned char *sha1,
2681 enum object_type *type,
2682 unsigned long *size,
2683 unsigned flag)
2685 void *data;
2686 const struct packed_git *p;
2687 const unsigned char *repl = lookup_replace_object_extended(sha1, flag);
2689 errno = 0;
2690 data = read_object(repl, type, size);
2691 if (data)
2692 return data;
2694 if (errno && errno != ENOENT)
2695 die_errno("failed to read object %s", sha1_to_hex(sha1));
2697 /* die if we replaced an object with one that does not exist */
2698 if (repl != sha1)
2699 die("replacement %s not found for %s",
2700 sha1_to_hex(repl), sha1_to_hex(sha1));
2702 if (has_loose_object(repl)) {
2703 const char *path = sha1_file_name(sha1);
2705 die("loose object %s (stored in %s) is corrupt",
2706 sha1_to_hex(repl), path);
2709 if ((p = has_packed_and_bad(repl)) != NULL)
2710 die("packed object %s (stored in %s) is corrupt",
2711 sha1_to_hex(repl), p->pack_name);
2713 return NULL;
2716 void *read_object_with_reference(const unsigned char *sha1,
2717 const char *required_type_name,
2718 unsigned long *size,
2719 unsigned char *actual_sha1_return)
2721 enum object_type type, required_type;
2722 void *buffer;
2723 unsigned long isize;
2724 unsigned char actual_sha1[20];
2726 required_type = type_from_string(required_type_name);
2727 hashcpy(actual_sha1, sha1);
2728 while (1) {
2729 int ref_length = -1;
2730 const char *ref_type = NULL;
2732 buffer = read_sha1_file(actual_sha1, &type, &isize);
2733 if (!buffer)
2734 return NULL;
2735 if (type == required_type) {
2736 *size = isize;
2737 if (actual_sha1_return)
2738 hashcpy(actual_sha1_return, actual_sha1);
2739 return buffer;
2741 /* Handle references */
2742 else if (type == OBJ_COMMIT)
2743 ref_type = "tree ";
2744 else if (type == OBJ_TAG)
2745 ref_type = "object ";
2746 else {
2747 free(buffer);
2748 return NULL;
2750 ref_length = strlen(ref_type);
2752 if (ref_length + 40 > isize ||
2753 memcmp(buffer, ref_type, ref_length) ||
2754 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2755 free(buffer);
2756 return NULL;
2758 free(buffer);
2759 /* Now we have the ID of the referred-to object in
2760 * actual_sha1. Check again. */
2764 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2765 const char *type, unsigned char *sha1,
2766 char *hdr, int *hdrlen)
2768 git_SHA_CTX c;
2770 /* Generate the header */
2771 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2773 /* Sha1.. */
2774 git_SHA1_Init(&c);
2775 git_SHA1_Update(&c, hdr, *hdrlen);
2776 git_SHA1_Update(&c, buf, len);
2777 git_SHA1_Final(sha1, &c);
2781 * Move the just written object into its final resting place.
2782 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2783 * "moving" is only a part of what it does, when no patch between
2784 * master to pu changes the call sites of this function.
2786 int move_temp_to_file(const char *tmpfile, const char *filename)
2788 int ret = 0;
2790 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2791 goto try_rename;
2792 else if (link(tmpfile, filename))
2793 ret = errno;
2796 * Coda hack - coda doesn't like cross-directory links,
2797 * so we fall back to a rename, which will mean that it
2798 * won't be able to check collisions, but that's not a
2799 * big deal.
2801 * The same holds for FAT formatted media.
2803 * When this succeeds, we just return. We have nothing
2804 * left to unlink.
2806 if (ret && ret != EEXIST) {
2807 try_rename:
2808 if (!rename(tmpfile, filename))
2809 goto out;
2810 ret = errno;
2812 unlink_or_warn(tmpfile);
2813 if (ret) {
2814 if (ret != EEXIST) {
2815 return error("unable to write sha1 filename %s: %s", filename, strerror(ret));
2817 /* FIXME!!! Collision check here ? */
2820 out:
2821 if (adjust_shared_perm(filename))
2822 return error("unable to set permission to '%s'", filename);
2823 return 0;
2826 static int write_buffer(int fd, const void *buf, size_t len)
2828 if (write_in_full(fd, buf, len) < 0)
2829 return error("file write error (%s)", strerror(errno));
2830 return 0;
2833 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2834 unsigned char *sha1)
2836 char hdr[32];
2837 int hdrlen;
2838 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2839 return 0;
2842 /* Finalize a file on disk, and close it. */
2843 static void close_sha1_file(int fd)
2845 if (fsync_object_files)
2846 fsync_or_die(fd, "sha1 file");
2847 if (close(fd) != 0)
2848 die_errno("error when closing sha1 file");
2851 /* Size of directory component, including the ending '/' */
2852 static inline int directory_size(const char *filename)
2854 const char *s = strrchr(filename, '/');
2855 if (!s)
2856 return 0;
2857 return s - filename + 1;
2861 * This creates a temporary file in the same directory as the final
2862 * 'filename'
2864 * We want to avoid cross-directory filename renames, because those
2865 * can have problems on various filesystems (FAT, NFS, Coda).
2867 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2869 int fd, dirlen = directory_size(filename);
2871 if (dirlen + 20 > bufsiz) {
2872 errno = ENAMETOOLONG;
2873 return -1;
2875 memcpy(buffer, filename, dirlen);
2876 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2877 fd = git_mkstemp_mode(buffer, 0444);
2878 if (fd < 0 && dirlen && errno == ENOENT) {
2879 /* Make sure the directory exists */
2880 memcpy(buffer, filename, dirlen);
2881 buffer[dirlen-1] = 0;
2882 if (mkdir(buffer, 0777) && errno != EEXIST)
2883 return -1;
2884 if (adjust_shared_perm(buffer))
2885 return -1;
2887 /* Try again */
2888 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2889 fd = git_mkstemp_mode(buffer, 0444);
2891 return fd;
2894 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2895 const void *buf, unsigned long len, time_t mtime)
2897 int fd, ret;
2898 unsigned char compressed[4096];
2899 git_zstream stream;
2900 git_SHA_CTX c;
2901 unsigned char parano_sha1[20];
2902 static char tmp_file[PATH_MAX];
2903 const char *filename = sha1_file_name(sha1);
2905 fd = create_tmpfile(tmp_file, sizeof(tmp_file), filename);
2906 if (fd < 0) {
2907 if (errno == EACCES)
2908 return error("insufficient permission for adding an object to repository database %s", get_object_directory());
2909 else
2910 return error("unable to create temporary file: %s", strerror(errno));
2913 /* Set it up */
2914 memset(&stream, 0, sizeof(stream));
2915 git_deflate_init(&stream, zlib_compression_level);
2916 stream.next_out = compressed;
2917 stream.avail_out = sizeof(compressed);
2918 git_SHA1_Init(&c);
2920 /* First header.. */
2921 stream.next_in = (unsigned char *)hdr;
2922 stream.avail_in = hdrlen;
2923 while (git_deflate(&stream, 0) == Z_OK)
2924 ; /* nothing */
2925 git_SHA1_Update(&c, hdr, hdrlen);
2927 /* Then the data itself.. */
2928 stream.next_in = (void *)buf;
2929 stream.avail_in = len;
2930 do {
2931 unsigned char *in0 = stream.next_in;
2932 ret = git_deflate(&stream, Z_FINISH);
2933 git_SHA1_Update(&c, in0, stream.next_in - in0);
2934 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2935 die("unable to write sha1 file");
2936 stream.next_out = compressed;
2937 stream.avail_out = sizeof(compressed);
2938 } while (ret == Z_OK);
2940 if (ret != Z_STREAM_END)
2941 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2942 ret = git_deflate_end_gently(&stream);
2943 if (ret != Z_OK)
2944 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2945 git_SHA1_Final(parano_sha1, &c);
2946 if (hashcmp(sha1, parano_sha1) != 0)
2947 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
2949 close_sha1_file(fd);
2951 if (mtime) {
2952 struct utimbuf utb;
2953 utb.actime = mtime;
2954 utb.modtime = mtime;
2955 if (utime(tmp_file, &utb) < 0)
2956 warning("failed utime() on %s: %s",
2957 tmp_file, strerror(errno));
2960 return move_temp_to_file(tmp_file, filename);
2963 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2965 unsigned char sha1[20];
2966 char hdr[32];
2967 int hdrlen;
2969 /* Normally if we have it in the pack then we do not bother writing
2970 * it out into .git/objects/??/?{38} file.
2972 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2973 if (returnsha1)
2974 hashcpy(returnsha1, sha1);
2975 if (has_sha1_file(sha1))
2976 return 0;
2977 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2980 int force_object_loose(const unsigned char *sha1, time_t mtime)
2982 void *buf;
2983 unsigned long len;
2984 enum object_type type;
2985 char hdr[32];
2986 int hdrlen;
2987 int ret;
2989 if (has_loose_object(sha1))
2990 return 0;
2991 buf = read_packed_sha1(sha1, &type, &len);
2992 if (!buf)
2993 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2994 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2995 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2996 free(buf);
2998 return ret;
3001 int has_pack_index(const unsigned char *sha1)
3003 struct stat st;
3004 if (stat(sha1_pack_index_name(sha1), &st))
3005 return 0;
3006 return 1;
3009 int has_sha1_pack(const unsigned char *sha1)
3011 struct pack_entry e;
3012 return find_pack_entry(sha1, &e);
3015 int has_sha1_file(const unsigned char *sha1)
3017 struct pack_entry e;
3019 if (find_pack_entry(sha1, &e))
3020 return 1;
3021 if (has_loose_object(sha1))
3022 return 1;
3023 reprepare_packed_git();
3024 return find_pack_entry(sha1, &e);
3027 static void check_tree(const void *buf, size_t size)
3029 struct tree_desc desc;
3030 struct name_entry entry;
3032 init_tree_desc(&desc, buf, size);
3033 while (tree_entry(&desc, &entry))
3034 /* do nothing
3035 * tree_entry() will die() on malformed entries */
3039 static void check_commit(const void *buf, size_t size)
3041 struct commit c;
3042 memset(&c, 0, sizeof(c));
3043 if (parse_commit_buffer(&c, buf, size))
3044 die("corrupt commit");
3047 static void check_tag(const void *buf, size_t size)
3049 struct tag t;
3050 memset(&t, 0, sizeof(t));
3051 if (parse_tag_buffer(&t, buf, size))
3052 die("corrupt tag");
3055 static int index_mem(unsigned char *sha1, void *buf, size_t size,
3056 enum object_type type,
3057 const char *path, unsigned flags)
3059 int ret, re_allocated = 0;
3060 int write_object = flags & HASH_WRITE_OBJECT;
3062 if (!type)
3063 type = OBJ_BLOB;
3066 * Convert blobs to git internal format
3068 if ((type == OBJ_BLOB) && path) {
3069 struct strbuf nbuf = STRBUF_INIT;
3070 if (convert_to_git(path, buf, size, &nbuf,
3071 write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
3072 buf = strbuf_detach(&nbuf, &size);
3073 re_allocated = 1;
3076 if (flags & HASH_FORMAT_CHECK) {
3077 if (type == OBJ_TREE)
3078 check_tree(buf, size);
3079 if (type == OBJ_COMMIT)
3080 check_commit(buf, size);
3081 if (type == OBJ_TAG)
3082 check_tag(buf, size);
3085 if (write_object)
3086 ret = write_sha1_file(buf, size, typename(type), sha1);
3087 else
3088 ret = hash_sha1_file(buf, size, typename(type), sha1);
3089 if (re_allocated)
3090 free(buf);
3091 return ret;
3094 static int index_pipe(unsigned char *sha1, int fd, enum object_type type,
3095 const char *path, unsigned flags)
3097 struct strbuf sbuf = STRBUF_INIT;
3098 int ret;
3100 if (strbuf_read(&sbuf, fd, 4096) >= 0)
3101 ret = index_mem(sha1, sbuf.buf, sbuf.len, type, path, flags);
3102 else
3103 ret = -1;
3104 strbuf_release(&sbuf);
3105 return ret;
3108 #define SMALL_FILE_SIZE (32*1024)
3110 static int index_core(unsigned char *sha1, int fd, size_t size,
3111 enum object_type type, const char *path,
3112 unsigned flags)
3114 int ret;
3116 if (!size) {
3117 ret = index_mem(sha1, NULL, size, type, path, flags);
3118 } else if (size <= SMALL_FILE_SIZE) {
3119 char *buf = xmalloc(size);
3120 if (size == read_in_full(fd, buf, size))
3121 ret = index_mem(sha1, buf, size, type, path, flags);
3122 else
3123 ret = error("short read %s", strerror(errno));
3124 free(buf);
3125 } else {
3126 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
3127 ret = index_mem(sha1, buf, size, type, path, flags);
3128 munmap(buf, size);
3130 return ret;
3134 * This creates one packfile per large blob unless bulk-checkin
3135 * machinery is "plugged".
3137 * This also bypasses the usual "convert-to-git" dance, and that is on
3138 * purpose. We could write a streaming version of the converting
3139 * functions and insert that before feeding the data to fast-import
3140 * (or equivalent in-core API described above). However, that is
3141 * somewhat complicated, as we do not know the size of the filter
3142 * result, which we need to know beforehand when writing a git object.
3143 * Since the primary motivation for trying to stream from the working
3144 * tree file and to avoid mmaping it in core is to deal with large
3145 * binary blobs, they generally do not want to get any conversion, and
3146 * callers should avoid this code path when filters are requested.
3148 static int index_stream(unsigned char *sha1, int fd, size_t size,
3149 enum object_type type, const char *path,
3150 unsigned flags)
3152 return index_bulk_checkin(sha1, fd, size, type, path, flags);
3155 int index_fd(unsigned char *sha1, int fd, struct stat *st,
3156 enum object_type type, const char *path, unsigned flags)
3158 int ret;
3159 size_t size = xsize_t(st->st_size);
3161 if (!S_ISREG(st->st_mode))
3162 ret = index_pipe(sha1, fd, type, path, flags);
3163 else if (size <= big_file_threshold || type != OBJ_BLOB ||
3164 (path && would_convert_to_git(path, NULL, 0, 0)))
3165 ret = index_core(sha1, fd, size, type, path, flags);
3166 else
3167 ret = index_stream(sha1, fd, size, type, path, flags);
3168 close(fd);
3169 return ret;
3172 int index_path(unsigned char *sha1, const char *path, struct stat *st, unsigned flags)
3174 int fd;
3175 struct strbuf sb = STRBUF_INIT;
3177 switch (st->st_mode & S_IFMT) {
3178 case S_IFREG:
3179 fd = open(path, O_RDONLY);
3180 if (fd < 0)
3181 return error("open(\"%s\"): %s", path,
3182 strerror(errno));
3183 if (index_fd(sha1, fd, st, OBJ_BLOB, path, flags) < 0)
3184 return error("%s: failed to insert into database",
3185 path);
3186 break;
3187 case S_IFLNK:
3188 if (strbuf_readlink(&sb, path, st->st_size)) {
3189 char *errstr = strerror(errno);
3190 return error("readlink(\"%s\"): %s", path,
3191 errstr);
3193 if (!(flags & HASH_WRITE_OBJECT))
3194 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
3195 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
3196 return error("%s: failed to insert into database",
3197 path);
3198 strbuf_release(&sb);
3199 break;
3200 case S_IFDIR:
3201 return resolve_gitlink_ref(path, "HEAD", sha1);
3202 default:
3203 return error("%s: unsupported file type", path);
3205 return 0;
3208 int read_pack_header(int fd, struct pack_header *header)
3210 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
3211 /* "eof before pack header was fully read" */
3212 return PH_ERROR_EOF;
3214 if (header->hdr_signature != htonl(PACK_SIGNATURE))
3215 /* "protocol error (pack signature mismatch detected)" */
3216 return PH_ERROR_PACK_SIGNATURE;
3217 if (!pack_version_ok(header->hdr_version))
3218 /* "protocol error (pack version unsupported)" */
3219 return PH_ERROR_PROTOCOL;
3220 return 0;
3223 void assert_sha1_type(const unsigned char *sha1, enum object_type expect)
3225 enum object_type type = sha1_object_info(sha1, NULL);
3226 if (type < 0)
3227 die("%s is not a valid object", sha1_to_hex(sha1));
3228 if (type != expect)
3229 die("%s is not a valid '%s' object", sha1_to_hex(sha1),
3230 typename(expect));