Merge branch 'ag/rebase-p'
[git.git] / packfile.c
blob7cd45aa4b2a0e098d597e4dea633d9b097b9b94c
1 #include "cache.h"
2 #include "list.h"
3 #include "pack.h"
4 #include "repository.h"
5 #include "dir.h"
6 #include "mergesort.h"
7 #include "packfile.h"
8 #include "delta.h"
9 #include "list.h"
10 #include "streaming.h"
11 #include "sha1-lookup.h"
12 #include "commit.h"
13 #include "object.h"
14 #include "tag.h"
15 #include "tree-walk.h"
16 #include "tree.h"
17 #include "object-store.h"
19 char *odb_pack_name(struct strbuf *buf,
20 const unsigned char *sha1,
21 const char *ext)
23 strbuf_reset(buf);
24 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
25 sha1_to_hex(sha1), ext);
26 return buf->buf;
29 char *sha1_pack_name(const unsigned char *sha1)
31 static struct strbuf buf = STRBUF_INIT;
32 return odb_pack_name(&buf, sha1, "pack");
35 char *sha1_pack_index_name(const unsigned char *sha1)
37 static struct strbuf buf = STRBUF_INIT;
38 return odb_pack_name(&buf, sha1, "idx");
41 static unsigned int pack_used_ctr;
42 static unsigned int pack_mmap_calls;
43 static unsigned int peak_pack_open_windows;
44 static unsigned int pack_open_windows;
45 static unsigned int pack_open_fds;
46 static unsigned int pack_max_fds;
47 static size_t peak_pack_mapped;
48 static size_t pack_mapped;
50 #define SZ_FMT PRIuMAX
51 static inline uintmax_t sz_fmt(size_t s) { return s; }
53 void pack_report(void)
55 fprintf(stderr,
56 "pack_report: getpagesize() = %10" SZ_FMT "\n"
57 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
58 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
59 sz_fmt(getpagesize()),
60 sz_fmt(packed_git_window_size),
61 sz_fmt(packed_git_limit));
62 fprintf(stderr,
63 "pack_report: pack_used_ctr = %10u\n"
64 "pack_report: pack_mmap_calls = %10u\n"
65 "pack_report: pack_open_windows = %10u / %10u\n"
66 "pack_report: pack_mapped = "
67 "%10" SZ_FMT " / %10" SZ_FMT "\n",
68 pack_used_ctr,
69 pack_mmap_calls,
70 pack_open_windows, peak_pack_open_windows,
71 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
75 * Open and mmap the index file at path, perform a couple of
76 * consistency checks, then record its information to p. Return 0 on
77 * success.
79 static int check_packed_git_idx(const char *path, struct packed_git *p)
81 void *idx_map;
82 struct pack_idx_header *hdr;
83 size_t idx_size;
84 uint32_t version, nr, i, *index;
85 int fd = git_open(path);
86 struct stat st;
87 const unsigned int hashsz = the_hash_algo->rawsz;
89 if (fd < 0)
90 return -1;
91 if (fstat(fd, &st)) {
92 close(fd);
93 return -1;
95 idx_size = xsize_t(st.st_size);
96 if (idx_size < 4 * 256 + hashsz + hashsz) {
97 close(fd);
98 return error("index file %s is too small", path);
100 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
101 close(fd);
103 hdr = idx_map;
104 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
105 version = ntohl(hdr->idx_version);
106 if (version < 2 || version > 2) {
107 munmap(idx_map, idx_size);
108 return error("index file %s is version %"PRIu32
109 " and is not supported by this binary"
110 " (try upgrading GIT to a newer version)",
111 path, version);
113 } else
114 version = 1;
116 nr = 0;
117 index = idx_map;
118 if (version > 1)
119 index += 2; /* skip index header */
120 for (i = 0; i < 256; i++) {
121 uint32_t n = ntohl(index[i]);
122 if (n < nr) {
123 munmap(idx_map, idx_size);
124 return error("non-monotonic index %s", path);
126 nr = n;
129 if (version == 1) {
131 * Total size:
132 * - 256 index entries 4 bytes each
133 * - 24-byte entries * nr (object ID + 4-byte offset)
134 * - hash of the packfile
135 * - file checksum
137 if (idx_size != 4*256 + nr * (hashsz + 4) + hashsz + hashsz) {
138 munmap(idx_map, idx_size);
139 return error("wrong index v1 file size in %s", path);
141 } else if (version == 2) {
143 * Minimum size:
144 * - 8 bytes of header
145 * - 256 index entries 4 bytes each
146 * - object ID entry * nr
147 * - 4-byte crc entry * nr
148 * - 4-byte offset entry * nr
149 * - hash of the packfile
150 * - file checksum
151 * And after the 4-byte offset table might be a
152 * variable sized table containing 8-byte entries
153 * for offsets larger than 2^31.
155 unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;
156 unsigned long max_size = min_size;
157 if (nr)
158 max_size += (nr - 1)*8;
159 if (idx_size < min_size || idx_size > max_size) {
160 munmap(idx_map, idx_size);
161 return error("wrong index v2 file size in %s", path);
163 if (idx_size != min_size &&
165 * make sure we can deal with large pack offsets.
166 * 31-bit signed offset won't be enough, neither
167 * 32-bit unsigned one will be.
169 (sizeof(off_t) <= 4)) {
170 munmap(idx_map, idx_size);
171 return error("pack too large for current definition of off_t in %s", path);
175 p->index_version = version;
176 p->index_data = idx_map;
177 p->index_size = idx_size;
178 p->num_objects = nr;
179 return 0;
182 int open_pack_index(struct packed_git *p)
184 char *idx_name;
185 size_t len;
186 int ret;
188 if (p->index_data)
189 return 0;
191 if (!strip_suffix(p->pack_name, ".pack", &len))
192 BUG("pack_name does not end in .pack");
193 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
194 ret = check_packed_git_idx(idx_name, p);
195 free(idx_name);
196 return ret;
199 static struct packed_git *alloc_packed_git(int extra)
201 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
202 memset(p, 0, sizeof(*p));
203 p->pack_fd = -1;
204 return p;
207 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
209 const char *path = sha1_pack_name(sha1);
210 size_t alloc = st_add(strlen(path), 1);
211 struct packed_git *p = alloc_packed_git(alloc);
213 memcpy(p->pack_name, path, alloc); /* includes NUL */
214 hashcpy(p->sha1, sha1);
215 if (check_packed_git_idx(idx_path, p)) {
216 free(p);
217 return NULL;
220 return p;
223 static void scan_windows(struct packed_git *p,
224 struct packed_git **lru_p,
225 struct pack_window **lru_w,
226 struct pack_window **lru_l)
228 struct pack_window *w, *w_l;
230 for (w_l = NULL, w = p->windows; w; w = w->next) {
231 if (!w->inuse_cnt) {
232 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
233 *lru_p = p;
234 *lru_w = w;
235 *lru_l = w_l;
238 w_l = w;
242 static int unuse_one_window(struct packed_git *current)
244 struct packed_git *p, *lru_p = NULL;
245 struct pack_window *lru_w = NULL, *lru_l = NULL;
247 if (current)
248 scan_windows(current, &lru_p, &lru_w, &lru_l);
249 for (p = the_repository->objects->packed_git; p; p = p->next)
250 scan_windows(p, &lru_p, &lru_w, &lru_l);
251 if (lru_p) {
252 munmap(lru_w->base, lru_w->len);
253 pack_mapped -= lru_w->len;
254 if (lru_l)
255 lru_l->next = lru_w->next;
256 else
257 lru_p->windows = lru_w->next;
258 free(lru_w);
259 pack_open_windows--;
260 return 1;
262 return 0;
265 void release_pack_memory(size_t need)
267 size_t cur = pack_mapped;
268 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
269 ; /* nothing */
272 void close_pack_windows(struct packed_git *p)
274 while (p->windows) {
275 struct pack_window *w = p->windows;
277 if (w->inuse_cnt)
278 die("pack '%s' still has open windows to it",
279 p->pack_name);
280 munmap(w->base, w->len);
281 pack_mapped -= w->len;
282 pack_open_windows--;
283 p->windows = w->next;
284 free(w);
288 static int close_pack_fd(struct packed_git *p)
290 if (p->pack_fd < 0)
291 return 0;
293 close(p->pack_fd);
294 pack_open_fds--;
295 p->pack_fd = -1;
297 return 1;
300 void close_pack_index(struct packed_git *p)
302 if (p->index_data) {
303 munmap((void *)p->index_data, p->index_size);
304 p->index_data = NULL;
308 void close_pack(struct packed_git *p)
310 close_pack_windows(p);
311 close_pack_fd(p);
312 close_pack_index(p);
315 void close_all_packs(struct raw_object_store *o)
317 struct packed_git *p;
319 for (p = o->packed_git; p; p = p->next)
320 if (p->do_not_close)
321 BUG("want to close pack marked 'do-not-close'");
322 else
323 close_pack(p);
327 * The LRU pack is the one with the oldest MRU window, preferring packs
328 * with no used windows, or the oldest mtime if it has no windows allocated.
330 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
332 struct pack_window *w, *this_mru_w;
333 int has_windows_inuse = 0;
336 * Reject this pack if it has windows and the previously selected
337 * one does not. If this pack does not have windows, reject
338 * it if the pack file is newer than the previously selected one.
340 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
341 return;
343 for (w = this_mru_w = p->windows; w; w = w->next) {
345 * Reject this pack if any of its windows are in use,
346 * but the previously selected pack did not have any
347 * inuse windows. Otherwise, record that this pack
348 * has windows in use.
350 if (w->inuse_cnt) {
351 if (*accept_windows_inuse)
352 has_windows_inuse = 1;
353 else
354 return;
357 if (w->last_used > this_mru_w->last_used)
358 this_mru_w = w;
361 * Reject this pack if it has windows that have been
362 * used more recently than the previously selected pack.
363 * If the previously selected pack had windows inuse and
364 * we have not encountered a window in this pack that is
365 * inuse, skip this check since we prefer a pack with no
366 * inuse windows to one that has inuse windows.
368 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
369 this_mru_w->last_used > (*mru_w)->last_used)
370 return;
374 * Select this pack.
376 *mru_w = this_mru_w;
377 *lru_p = p;
378 *accept_windows_inuse = has_windows_inuse;
381 static int close_one_pack(void)
383 struct packed_git *p, *lru_p = NULL;
384 struct pack_window *mru_w = NULL;
385 int accept_windows_inuse = 1;
387 for (p = the_repository->objects->packed_git; p; p = p->next) {
388 if (p->pack_fd == -1)
389 continue;
390 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
393 if (lru_p)
394 return close_pack_fd(lru_p);
396 return 0;
399 static unsigned int get_max_fd_limit(void)
401 #ifdef RLIMIT_NOFILE
403 struct rlimit lim;
405 if (!getrlimit(RLIMIT_NOFILE, &lim))
406 return lim.rlim_cur;
408 #endif
410 #ifdef _SC_OPEN_MAX
412 long open_max = sysconf(_SC_OPEN_MAX);
413 if (0 < open_max)
414 return open_max;
416 * Otherwise, we got -1 for one of the two
417 * reasons:
419 * (1) sysconf() did not understand _SC_OPEN_MAX
420 * and signaled an error with -1; or
421 * (2) sysconf() said there is no limit.
423 * We _could_ clear errno before calling sysconf() to
424 * tell these two cases apart and return a huge number
425 * in the latter case to let the caller cap it to a
426 * value that is not so selfish, but letting the
427 * fallback OPEN_MAX codepath take care of these cases
428 * is a lot simpler.
431 #endif
433 #ifdef OPEN_MAX
434 return OPEN_MAX;
435 #else
436 return 1; /* see the caller ;-) */
437 #endif
441 * Do not call this directly as this leaks p->pack_fd on error return;
442 * call open_packed_git() instead.
444 static int open_packed_git_1(struct packed_git *p)
446 struct stat st;
447 struct pack_header hdr;
448 unsigned char hash[GIT_MAX_RAWSZ];
449 unsigned char *idx_hash;
450 long fd_flag;
451 ssize_t read_result;
452 const unsigned hashsz = the_hash_algo->rawsz;
454 if (!p->index_data && open_pack_index(p))
455 return error("packfile %s index unavailable", p->pack_name);
457 if (!pack_max_fds) {
458 unsigned int max_fds = get_max_fd_limit();
460 /* Save 3 for stdin/stdout/stderr, 22 for work */
461 if (25 < max_fds)
462 pack_max_fds = max_fds - 25;
463 else
464 pack_max_fds = 1;
467 while (pack_max_fds <= pack_open_fds && close_one_pack())
468 ; /* nothing */
470 p->pack_fd = git_open(p->pack_name);
471 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
472 return -1;
473 pack_open_fds++;
475 /* If we created the struct before we had the pack we lack size. */
476 if (!p->pack_size) {
477 if (!S_ISREG(st.st_mode))
478 return error("packfile %s not a regular file", p->pack_name);
479 p->pack_size = st.st_size;
480 } else if (p->pack_size != st.st_size)
481 return error("packfile %s size changed", p->pack_name);
483 /* We leave these file descriptors open with sliding mmap;
484 * there is no point keeping them open across exec(), though.
486 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
487 if (fd_flag < 0)
488 return error("cannot determine file descriptor flags");
489 fd_flag |= FD_CLOEXEC;
490 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
491 return error("cannot set FD_CLOEXEC");
493 /* Verify we recognize this pack file format. */
494 read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
495 if (read_result < 0)
496 return error_errno("error reading from %s", p->pack_name);
497 if (read_result != sizeof(hdr))
498 return error("file %s is far too short to be a packfile", p->pack_name);
499 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
500 return error("file %s is not a GIT packfile", p->pack_name);
501 if (!pack_version_ok(hdr.hdr_version))
502 return error("packfile %s is version %"PRIu32" and not"
503 " supported (try upgrading GIT to a newer version)",
504 p->pack_name, ntohl(hdr.hdr_version));
506 /* Verify the pack matches its index. */
507 if (p->num_objects != ntohl(hdr.hdr_entries))
508 return error("packfile %s claims to have %"PRIu32" objects"
509 " while index indicates %"PRIu32" objects",
510 p->pack_name, ntohl(hdr.hdr_entries),
511 p->num_objects);
512 if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1)
513 return error("end of packfile %s is unavailable", p->pack_name);
514 read_result = read_in_full(p->pack_fd, hash, hashsz);
515 if (read_result < 0)
516 return error_errno("error reading from %s", p->pack_name);
517 if (read_result != hashsz)
518 return error("packfile %s signature is unavailable", p->pack_name);
519 idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
520 if (hashcmp(hash, idx_hash))
521 return error("packfile %s does not match index", p->pack_name);
522 return 0;
525 static int open_packed_git(struct packed_git *p)
527 if (!open_packed_git_1(p))
528 return 0;
529 close_pack_fd(p);
530 return -1;
533 static int in_window(struct pack_window *win, off_t offset)
535 /* We must promise at least one full hash after the
536 * offset is available from this window, otherwise the offset
537 * is not actually in this window and a different window (which
538 * has that one hash excess) must be used. This is to support
539 * the object header and delta base parsing routines below.
541 off_t win_off = win->offset;
542 return win_off <= offset
543 && (offset + the_hash_algo->rawsz) <= (win_off + win->len);
546 unsigned char *use_pack(struct packed_git *p,
547 struct pack_window **w_cursor,
548 off_t offset,
549 unsigned long *left)
551 struct pack_window *win = *w_cursor;
553 /* Since packfiles end in a hash of their content and it's
554 * pointless to ask for an offset into the middle of that
555 * hash, and the in_window function above wouldn't match
556 * don't allow an offset too close to the end of the file.
558 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
559 die("packfile %s cannot be accessed", p->pack_name);
560 if (offset > (p->pack_size - the_hash_algo->rawsz))
561 die("offset beyond end of packfile (truncated pack?)");
562 if (offset < 0)
563 die(_("offset before end of packfile (broken .idx?)"));
565 if (!win || !in_window(win, offset)) {
566 if (win)
567 win->inuse_cnt--;
568 for (win = p->windows; win; win = win->next) {
569 if (in_window(win, offset))
570 break;
572 if (!win) {
573 size_t window_align = packed_git_window_size / 2;
574 off_t len;
576 if (p->pack_fd == -1 && open_packed_git(p))
577 die("packfile %s cannot be accessed", p->pack_name);
579 win = xcalloc(1, sizeof(*win));
580 win->offset = (offset / window_align) * window_align;
581 len = p->pack_size - win->offset;
582 if (len > packed_git_window_size)
583 len = packed_git_window_size;
584 win->len = (size_t)len;
585 pack_mapped += win->len;
586 while (packed_git_limit < pack_mapped
587 && unuse_one_window(p))
588 ; /* nothing */
589 win->base = xmmap(NULL, win->len,
590 PROT_READ, MAP_PRIVATE,
591 p->pack_fd, win->offset);
592 if (win->base == MAP_FAILED)
593 die_errno("packfile %s cannot be mapped",
594 p->pack_name);
595 if (!win->offset && win->len == p->pack_size
596 && !p->do_not_close)
597 close_pack_fd(p);
598 pack_mmap_calls++;
599 pack_open_windows++;
600 if (pack_mapped > peak_pack_mapped)
601 peak_pack_mapped = pack_mapped;
602 if (pack_open_windows > peak_pack_open_windows)
603 peak_pack_open_windows = pack_open_windows;
604 win->next = p->windows;
605 p->windows = win;
608 if (win != *w_cursor) {
609 win->last_used = pack_used_ctr++;
610 win->inuse_cnt++;
611 *w_cursor = win;
613 offset -= win->offset;
614 if (left)
615 *left = win->len - xsize_t(offset);
616 return win->base + offset;
619 void unuse_pack(struct pack_window **w_cursor)
621 struct pack_window *w = *w_cursor;
622 if (w) {
623 w->inuse_cnt--;
624 *w_cursor = NULL;
628 static void try_to_free_pack_memory(size_t size)
630 release_pack_memory(size);
633 struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
635 static int have_set_try_to_free_routine;
636 struct stat st;
637 size_t alloc;
638 struct packed_git *p;
640 if (!have_set_try_to_free_routine) {
641 have_set_try_to_free_routine = 1;
642 set_try_to_free_routine(try_to_free_pack_memory);
646 * Make sure a corresponding .pack file exists and that
647 * the index looks sane.
649 if (!strip_suffix_mem(path, &path_len, ".idx"))
650 return NULL;
653 * ".promisor" is long enough to hold any suffix we're adding (and
654 * the use xsnprintf double-checks that)
656 alloc = st_add3(path_len, strlen(".promisor"), 1);
657 p = alloc_packed_git(alloc);
658 memcpy(p->pack_name, path, path_len);
660 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
661 if (!access(p->pack_name, F_OK))
662 p->pack_keep = 1;
664 xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
665 if (!access(p->pack_name, F_OK))
666 p->pack_promisor = 1;
668 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
669 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
670 free(p);
671 return NULL;
674 /* ok, it looks sane as far as we can check without
675 * actually mapping the pack file.
677 p->pack_size = st.st_size;
678 p->pack_local = local;
679 p->mtime = st.st_mtime;
680 if (path_len < the_hash_algo->hexsz ||
681 get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->sha1))
682 hashclr(p->sha1);
683 return p;
686 void install_packed_git(struct repository *r, struct packed_git *pack)
688 if (pack->pack_fd != -1)
689 pack_open_fds++;
691 pack->next = r->objects->packed_git;
692 r->objects->packed_git = pack;
695 void (*report_garbage)(unsigned seen_bits, const char *path);
697 static void report_helper(const struct string_list *list,
698 int seen_bits, int first, int last)
700 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
701 return;
703 for (; first < last; first++)
704 report_garbage(seen_bits, list->items[first].string);
707 static void report_pack_garbage(struct string_list *list)
709 int i, baselen = -1, first = 0, seen_bits = 0;
711 if (!report_garbage)
712 return;
714 string_list_sort(list);
716 for (i = 0; i < list->nr; i++) {
717 const char *path = list->items[i].string;
718 if (baselen != -1 &&
719 strncmp(path, list->items[first].string, baselen)) {
720 report_helper(list, seen_bits, first, i);
721 baselen = -1;
722 seen_bits = 0;
724 if (baselen == -1) {
725 const char *dot = strrchr(path, '.');
726 if (!dot) {
727 report_garbage(PACKDIR_FILE_GARBAGE, path);
728 continue;
730 baselen = dot - path + 1;
731 first = i;
733 if (!strcmp(path + baselen, "pack"))
734 seen_bits |= 1;
735 else if (!strcmp(path + baselen, "idx"))
736 seen_bits |= 2;
738 report_helper(list, seen_bits, first, list->nr);
741 static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
743 struct strbuf path = STRBUF_INIT;
744 size_t dirnamelen;
745 DIR *dir;
746 struct dirent *de;
747 struct string_list garbage = STRING_LIST_INIT_DUP;
749 strbuf_addstr(&path, objdir);
750 strbuf_addstr(&path, "/pack");
751 dir = opendir(path.buf);
752 if (!dir) {
753 if (errno != ENOENT)
754 error_errno("unable to open object pack directory: %s",
755 path.buf);
756 strbuf_release(&path);
757 return;
759 strbuf_addch(&path, '/');
760 dirnamelen = path.len;
761 while ((de = readdir(dir)) != NULL) {
762 struct packed_git *p;
763 size_t base_len;
765 if (is_dot_or_dotdot(de->d_name))
766 continue;
768 strbuf_setlen(&path, dirnamelen);
769 strbuf_addstr(&path, de->d_name);
771 base_len = path.len;
772 if (strip_suffix_mem(path.buf, &base_len, ".idx")) {
773 /* Don't reopen a pack we already have. */
774 for (p = r->objects->packed_git; p;
775 p = p->next) {
776 size_t len;
777 if (strip_suffix(p->pack_name, ".pack", &len) &&
778 len == base_len &&
779 !memcmp(p->pack_name, path.buf, len))
780 break;
782 if (p == NULL &&
784 * See if it really is a valid .idx file with
785 * corresponding .pack file that we can map.
787 (p = add_packed_git(path.buf, path.len, local)) != NULL)
788 install_packed_git(r, p);
791 if (!report_garbage)
792 continue;
794 if (ends_with(de->d_name, ".idx") ||
795 ends_with(de->d_name, ".pack") ||
796 ends_with(de->d_name, ".bitmap") ||
797 ends_with(de->d_name, ".keep") ||
798 ends_with(de->d_name, ".promisor"))
799 string_list_append(&garbage, path.buf);
800 else
801 report_garbage(PACKDIR_FILE_GARBAGE, path.buf);
803 closedir(dir);
804 report_pack_garbage(&garbage);
805 string_list_clear(&garbage, 0);
806 strbuf_release(&path);
809 static void prepare_packed_git(struct repository *r);
811 * Give a fast, rough count of the number of objects in the repository. This
812 * ignores loose objects completely. If you have a lot of them, then either
813 * you should repack because your performance will be awful, or they are
814 * all unreachable objects about to be pruned, in which case they're not really
815 * interesting as a measure of repo size in the first place.
817 unsigned long approximate_object_count(void)
819 if (!the_repository->objects->approximate_object_count_valid) {
820 unsigned long count;
821 struct packed_git *p;
823 prepare_packed_git(the_repository);
824 count = 0;
825 for (p = the_repository->objects->packed_git; p; p = p->next) {
826 if (open_pack_index(p))
827 continue;
828 count += p->num_objects;
830 the_repository->objects->approximate_object_count = count;
832 return the_repository->objects->approximate_object_count;
835 static void *get_next_packed_git(const void *p)
837 return ((const struct packed_git *)p)->next;
840 static void set_next_packed_git(void *p, void *next)
842 ((struct packed_git *)p)->next = next;
845 static int sort_pack(const void *a_, const void *b_)
847 const struct packed_git *a = a_;
848 const struct packed_git *b = b_;
849 int st;
852 * Local packs tend to contain objects specific to our
853 * variant of the project than remote ones. In addition,
854 * remote ones could be on a network mounted filesystem.
855 * Favor local ones for these reasons.
857 st = a->pack_local - b->pack_local;
858 if (st)
859 return -st;
862 * Younger packs tend to contain more recent objects,
863 * and more recent objects tend to get accessed more
864 * often.
866 if (a->mtime < b->mtime)
867 return 1;
868 else if (a->mtime == b->mtime)
869 return 0;
870 return -1;
873 static void rearrange_packed_git(struct repository *r)
875 r->objects->packed_git = llist_mergesort(
876 r->objects->packed_git, get_next_packed_git,
877 set_next_packed_git, sort_pack);
880 static void prepare_packed_git_mru(struct repository *r)
882 struct packed_git *p;
884 INIT_LIST_HEAD(&r->objects->packed_git_mru);
886 for (p = r->objects->packed_git; p; p = p->next)
887 list_add_tail(&p->mru, &r->objects->packed_git_mru);
890 static void prepare_packed_git(struct repository *r)
892 struct alternate_object_database *alt;
894 if (r->objects->packed_git_initialized)
895 return;
896 prepare_packed_git_one(r, r->objects->objectdir, 1);
897 prepare_alt_odb(r);
898 for (alt = r->objects->alt_odb_list; alt; alt = alt->next)
899 prepare_packed_git_one(r, alt->path, 0);
900 rearrange_packed_git(r);
901 prepare_packed_git_mru(r);
902 r->objects->packed_git_initialized = 1;
905 void reprepare_packed_git(struct repository *r)
907 r->objects->approximate_object_count_valid = 0;
908 r->objects->packed_git_initialized = 0;
909 prepare_packed_git(r);
912 struct packed_git *get_packed_git(struct repository *r)
914 prepare_packed_git(r);
915 return r->objects->packed_git;
918 struct list_head *get_packed_git_mru(struct repository *r)
920 prepare_packed_git(r);
921 return &r->objects->packed_git_mru;
924 unsigned long unpack_object_header_buffer(const unsigned char *buf,
925 unsigned long len, enum object_type *type, unsigned long *sizep)
927 unsigned shift;
928 unsigned long size, c;
929 unsigned long used = 0;
931 c = buf[used++];
932 *type = (c >> 4) & 7;
933 size = c & 15;
934 shift = 4;
935 while (c & 0x80) {
936 if (len <= used || bitsizeof(long) <= shift) {
937 error("bad object header");
938 size = used = 0;
939 break;
941 c = buf[used++];
942 size += (c & 0x7f) << shift;
943 shift += 7;
945 *sizep = size;
946 return used;
949 unsigned long get_size_from_delta(struct packed_git *p,
950 struct pack_window **w_curs,
951 off_t curpos)
953 const unsigned char *data;
954 unsigned char delta_head[20], *in;
955 git_zstream stream;
956 int st;
958 memset(&stream, 0, sizeof(stream));
959 stream.next_out = delta_head;
960 stream.avail_out = sizeof(delta_head);
962 git_inflate_init(&stream);
963 do {
964 in = use_pack(p, w_curs, curpos, &stream.avail_in);
965 stream.next_in = in;
966 st = git_inflate(&stream, Z_FINISH);
967 curpos += stream.next_in - in;
968 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
969 stream.total_out < sizeof(delta_head));
970 git_inflate_end(&stream);
971 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
972 error("delta data unpack-initial failed");
973 return 0;
976 /* Examine the initial part of the delta to figure out
977 * the result size.
979 data = delta_head;
981 /* ignore base size */
982 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
984 /* Read the result size */
985 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
988 int unpack_object_header(struct packed_git *p,
989 struct pack_window **w_curs,
990 off_t *curpos,
991 unsigned long *sizep)
993 unsigned char *base;
994 unsigned long left;
995 unsigned long used;
996 enum object_type type;
998 /* use_pack() assures us we have [base, base + 20) available
999 * as a range that we can look at. (Its actually the hash
1000 * size that is assured.) With our object header encoding
1001 * the maximum deflated object size is 2^137, which is just
1002 * insane, so we know won't exceed what we have been given.
1004 base = use_pack(p, w_curs, *curpos, &left);
1005 used = unpack_object_header_buffer(base, left, &type, sizep);
1006 if (!used) {
1007 type = OBJ_BAD;
1008 } else
1009 *curpos += used;
1011 return type;
1014 void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
1016 unsigned i;
1017 for (i = 0; i < p->num_bad_objects; i++)
1018 if (!hashcmp(sha1, p->bad_object_sha1 + GIT_SHA1_RAWSZ * i))
1019 return;
1020 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1021 st_mult(GIT_MAX_RAWSZ,
1022 st_add(p->num_bad_objects, 1)));
1023 hashcpy(p->bad_object_sha1 + GIT_SHA1_RAWSZ * p->num_bad_objects, sha1);
1024 p->num_bad_objects++;
1027 const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1029 struct packed_git *p;
1030 unsigned i;
1032 for (p = the_repository->objects->packed_git; p; p = p->next)
1033 for (i = 0; i < p->num_bad_objects; i++)
1034 if (!hashcmp(sha1,
1035 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1036 return p;
1037 return NULL;
1040 static off_t get_delta_base(struct packed_git *p,
1041 struct pack_window **w_curs,
1042 off_t *curpos,
1043 enum object_type type,
1044 off_t delta_obj_offset)
1046 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1047 off_t base_offset;
1049 /* use_pack() assured us we have [base_info, base_info + 20)
1050 * as a range that we can look at without walking off the
1051 * end of the mapped window. Its actually the hash size
1052 * that is assured. An OFS_DELTA longer than the hash size
1053 * is stupid, as then a REF_DELTA would be smaller to store.
1055 if (type == OBJ_OFS_DELTA) {
1056 unsigned used = 0;
1057 unsigned char c = base_info[used++];
1058 base_offset = c & 127;
1059 while (c & 128) {
1060 base_offset += 1;
1061 if (!base_offset || MSB(base_offset, 7))
1062 return 0; /* overflow */
1063 c = base_info[used++];
1064 base_offset = (base_offset << 7) + (c & 127);
1066 base_offset = delta_obj_offset - base_offset;
1067 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1068 return 0; /* out of bound */
1069 *curpos += used;
1070 } else if (type == OBJ_REF_DELTA) {
1071 /* The base entry _must_ be in the same pack */
1072 base_offset = find_pack_entry_one(base_info, p);
1073 *curpos += the_hash_algo->rawsz;
1074 } else
1075 die("I am totally screwed");
1076 return base_offset;
1080 * Like get_delta_base above, but we return the sha1 instead of the pack
1081 * offset. This means it is cheaper for REF deltas (we do not have to do
1082 * the final object lookup), but more expensive for OFS deltas (we
1083 * have to load the revidx to convert the offset back into a sha1).
1085 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1086 struct pack_window **w_curs,
1087 off_t curpos,
1088 enum object_type type,
1089 off_t delta_obj_offset)
1091 if (type == OBJ_REF_DELTA) {
1092 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1093 return base;
1094 } else if (type == OBJ_OFS_DELTA) {
1095 struct revindex_entry *revidx;
1096 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1097 type, delta_obj_offset);
1099 if (!base_offset)
1100 return NULL;
1102 revidx = find_pack_revindex(p, base_offset);
1103 if (!revidx)
1104 return NULL;
1106 return nth_packed_object_sha1(p, revidx->nr);
1107 } else
1108 return NULL;
1111 static int retry_bad_packed_offset(struct repository *r,
1112 struct packed_git *p,
1113 off_t obj_offset)
1115 int type;
1116 struct revindex_entry *revidx;
1117 struct object_id oid;
1118 revidx = find_pack_revindex(p, obj_offset);
1119 if (!revidx)
1120 return OBJ_BAD;
1121 nth_packed_object_oid(&oid, p, revidx->nr);
1122 mark_bad_packed_object(p, oid.hash);
1123 type = oid_object_info(r, &oid, NULL);
1124 if (type <= OBJ_NONE)
1125 return OBJ_BAD;
1126 return type;
1129 #define POI_STACK_PREALLOC 64
1131 static enum object_type packed_to_object_type(struct repository *r,
1132 struct packed_git *p,
1133 off_t obj_offset,
1134 enum object_type type,
1135 struct pack_window **w_curs,
1136 off_t curpos)
1138 off_t small_poi_stack[POI_STACK_PREALLOC];
1139 off_t *poi_stack = small_poi_stack;
1140 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1142 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1143 off_t base_offset;
1144 unsigned long size;
1145 /* Push the object we're going to leave behind */
1146 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1147 poi_stack_alloc = alloc_nr(poi_stack_nr);
1148 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1149 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1150 } else {
1151 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1153 poi_stack[poi_stack_nr++] = obj_offset;
1154 /* If parsing the base offset fails, just unwind */
1155 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1156 if (!base_offset)
1157 goto unwind;
1158 curpos = obj_offset = base_offset;
1159 type = unpack_object_header(p, w_curs, &curpos, &size);
1160 if (type <= OBJ_NONE) {
1161 /* If getting the base itself fails, we first
1162 * retry the base, otherwise unwind */
1163 type = retry_bad_packed_offset(r, p, base_offset);
1164 if (type > OBJ_NONE)
1165 goto out;
1166 goto unwind;
1170 switch (type) {
1171 case OBJ_BAD:
1172 case OBJ_COMMIT:
1173 case OBJ_TREE:
1174 case OBJ_BLOB:
1175 case OBJ_TAG:
1176 break;
1177 default:
1178 error("unknown object type %i at offset %"PRIuMAX" in %s",
1179 type, (uintmax_t)obj_offset, p->pack_name);
1180 type = OBJ_BAD;
1183 out:
1184 if (poi_stack != small_poi_stack)
1185 free(poi_stack);
1186 return type;
1188 unwind:
1189 while (poi_stack_nr) {
1190 obj_offset = poi_stack[--poi_stack_nr];
1191 type = retry_bad_packed_offset(r, p, obj_offset);
1192 if (type > OBJ_NONE)
1193 goto out;
1195 type = OBJ_BAD;
1196 goto out;
1199 static struct hashmap delta_base_cache;
1200 static size_t delta_base_cached;
1202 static LIST_HEAD(delta_base_cache_lru);
1204 struct delta_base_cache_key {
1205 struct packed_git *p;
1206 off_t base_offset;
1209 struct delta_base_cache_entry {
1210 struct hashmap hash;
1211 struct delta_base_cache_key key;
1212 struct list_head lru;
1213 void *data;
1214 unsigned long size;
1215 enum object_type type;
1218 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
1220 unsigned int hash;
1222 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
1223 hash += (hash >> 8) + (hash >> 16);
1224 return hash;
1227 static struct delta_base_cache_entry *
1228 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1230 struct hashmap_entry entry;
1231 struct delta_base_cache_key key;
1233 if (!delta_base_cache.cmpfn)
1234 return NULL;
1236 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
1237 key.p = p;
1238 key.base_offset = base_offset;
1239 return hashmap_get(&delta_base_cache, &entry, &key);
1242 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
1243 const struct delta_base_cache_key *b)
1245 return a->p == b->p && a->base_offset == b->base_offset;
1248 static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
1249 const void *va, const void *vb,
1250 const void *vkey)
1252 const struct delta_base_cache_entry *a = va, *b = vb;
1253 const struct delta_base_cache_key *key = vkey;
1254 if (key)
1255 return !delta_base_cache_key_eq(&a->key, key);
1256 else
1257 return !delta_base_cache_key_eq(&a->key, &b->key);
1260 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1262 return !!get_delta_base_cache_entry(p, base_offset);
1266 * Remove the entry from the cache, but do _not_ free the associated
1267 * entry data. The caller takes ownership of the "data" buffer, and
1268 * should copy out any fields it wants before detaching.
1270 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1272 hashmap_remove(&delta_base_cache, ent, &ent->key);
1273 list_del(&ent->lru);
1274 delta_base_cached -= ent->size;
1275 free(ent);
1278 static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
1279 off_t base_offset, unsigned long *base_size,
1280 enum object_type *type)
1282 struct delta_base_cache_entry *ent;
1284 ent = get_delta_base_cache_entry(p, base_offset);
1285 if (!ent)
1286 return unpack_entry(r, p, base_offset, type, base_size);
1288 if (type)
1289 *type = ent->type;
1290 if (base_size)
1291 *base_size = ent->size;
1292 return xmemdupz(ent->data, ent->size);
1295 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1297 free(ent->data);
1298 detach_delta_base_cache_entry(ent);
1301 void clear_delta_base_cache(void)
1303 struct list_head *lru, *tmp;
1304 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1305 struct delta_base_cache_entry *entry =
1306 list_entry(lru, struct delta_base_cache_entry, lru);
1307 release_delta_base_cache(entry);
1311 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1312 void *base, unsigned long base_size, enum object_type type)
1314 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
1315 struct list_head *lru, *tmp;
1317 delta_base_cached += base_size;
1319 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1320 struct delta_base_cache_entry *f =
1321 list_entry(lru, struct delta_base_cache_entry, lru);
1322 if (delta_base_cached <= delta_base_cache_limit)
1323 break;
1324 release_delta_base_cache(f);
1327 ent->key.p = p;
1328 ent->key.base_offset = base_offset;
1329 ent->type = type;
1330 ent->data = base;
1331 ent->size = base_size;
1332 list_add_tail(&ent->lru, &delta_base_cache_lru);
1334 if (!delta_base_cache.cmpfn)
1335 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
1336 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
1337 hashmap_add(&delta_base_cache, ent);
1340 int packed_object_info(struct repository *r, struct packed_git *p,
1341 off_t obj_offset, struct object_info *oi)
1343 struct pack_window *w_curs = NULL;
1344 unsigned long size;
1345 off_t curpos = obj_offset;
1346 enum object_type type;
1349 * We always get the representation type, but only convert it to
1350 * a "real" type later if the caller is interested.
1352 if (oi->contentp) {
1353 *oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
1354 &type);
1355 if (!*oi->contentp)
1356 type = OBJ_BAD;
1357 } else {
1358 type = unpack_object_header(p, &w_curs, &curpos, &size);
1361 if (!oi->contentp && oi->sizep) {
1362 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1363 off_t tmp_pos = curpos;
1364 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1365 type, obj_offset);
1366 if (!base_offset) {
1367 type = OBJ_BAD;
1368 goto out;
1370 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1371 if (*oi->sizep == 0) {
1372 type = OBJ_BAD;
1373 goto out;
1375 } else {
1376 *oi->sizep = size;
1380 if (oi->disk_sizep) {
1381 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1382 *oi->disk_sizep = revidx[1].offset - obj_offset;
1385 if (oi->typep || oi->type_name) {
1386 enum object_type ptot;
1387 ptot = packed_to_object_type(r, p, obj_offset,
1388 type, &w_curs, curpos);
1389 if (oi->typep)
1390 *oi->typep = ptot;
1391 if (oi->type_name) {
1392 const char *tn = type_name(ptot);
1393 if (tn)
1394 strbuf_addstr(oi->type_name, tn);
1396 if (ptot < 0) {
1397 type = OBJ_BAD;
1398 goto out;
1402 if (oi->delta_base_sha1) {
1403 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1404 const unsigned char *base;
1406 base = get_delta_base_sha1(p, &w_curs, curpos,
1407 type, obj_offset);
1408 if (!base) {
1409 type = OBJ_BAD;
1410 goto out;
1413 hashcpy(oi->delta_base_sha1, base);
1414 } else
1415 hashclr(oi->delta_base_sha1);
1418 oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
1419 OI_PACKED;
1421 out:
1422 unuse_pack(&w_curs);
1423 return type;
1426 static void *unpack_compressed_entry(struct packed_git *p,
1427 struct pack_window **w_curs,
1428 off_t curpos,
1429 unsigned long size)
1431 int st;
1432 git_zstream stream;
1433 unsigned char *buffer, *in;
1435 buffer = xmallocz_gently(size);
1436 if (!buffer)
1437 return NULL;
1438 memset(&stream, 0, sizeof(stream));
1439 stream.next_out = buffer;
1440 stream.avail_out = size + 1;
1442 git_inflate_init(&stream);
1443 do {
1444 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1445 stream.next_in = in;
1446 st = git_inflate(&stream, Z_FINISH);
1447 if (!stream.avail_out)
1448 break; /* the payload is larger than it should be */
1449 curpos += stream.next_in - in;
1450 } while (st == Z_OK || st == Z_BUF_ERROR);
1451 git_inflate_end(&stream);
1452 if ((st != Z_STREAM_END) || stream.total_out != size) {
1453 free(buffer);
1454 return NULL;
1457 /* versions of zlib can clobber unconsumed portion of outbuf */
1458 buffer[size] = '\0';
1460 return buffer;
1463 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1465 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
1466 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
1467 p->pack_name, (uintmax_t)obj_offset);
1470 int do_check_packed_object_crc;
1472 #define UNPACK_ENTRY_STACK_PREALLOC 64
1473 struct unpack_entry_stack_ent {
1474 off_t obj_offset;
1475 off_t curpos;
1476 unsigned long size;
1479 static void *read_object(struct repository *r,
1480 const struct object_id *oid,
1481 enum object_type *type,
1482 unsigned long *size)
1484 struct object_info oi = OBJECT_INFO_INIT;
1485 void *content;
1486 oi.typep = type;
1487 oi.sizep = size;
1488 oi.contentp = &content;
1490 if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1491 return NULL;
1492 return content;
1495 void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
1496 enum object_type *final_type, unsigned long *final_size)
1498 struct pack_window *w_curs = NULL;
1499 off_t curpos = obj_offset;
1500 void *data = NULL;
1501 unsigned long size;
1502 enum object_type type;
1503 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
1504 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
1505 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
1506 int base_from_cache = 0;
1508 write_pack_access_log(p, obj_offset);
1510 /* PHASE 1: drill down to the innermost base object */
1511 for (;;) {
1512 off_t base_offset;
1513 int i;
1514 struct delta_base_cache_entry *ent;
1516 ent = get_delta_base_cache_entry(p, curpos);
1517 if (ent) {
1518 type = ent->type;
1519 data = ent->data;
1520 size = ent->size;
1521 detach_delta_base_cache_entry(ent);
1522 base_from_cache = 1;
1523 break;
1526 if (do_check_packed_object_crc && p->index_version > 1) {
1527 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1528 off_t len = revidx[1].offset - obj_offset;
1529 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1530 struct object_id oid;
1531 nth_packed_object_oid(&oid, p, revidx->nr);
1532 error("bad packed object CRC for %s",
1533 oid_to_hex(&oid));
1534 mark_bad_packed_object(p, oid.hash);
1535 data = NULL;
1536 goto out;
1540 type = unpack_object_header(p, &w_curs, &curpos, &size);
1541 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
1542 break;
1544 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1545 if (!base_offset) {
1546 error("failed to validate delta base reference "
1547 "at offset %"PRIuMAX" from %s",
1548 (uintmax_t)curpos, p->pack_name);
1549 /* bail to phase 2, in hopes of recovery */
1550 data = NULL;
1551 break;
1554 /* push object, proceed to base */
1555 if (delta_stack_nr >= delta_stack_alloc
1556 && delta_stack == small_delta_stack) {
1557 delta_stack_alloc = alloc_nr(delta_stack_nr);
1558 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
1559 memcpy(delta_stack, small_delta_stack,
1560 sizeof(*delta_stack)*delta_stack_nr);
1561 } else {
1562 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
1564 i = delta_stack_nr++;
1565 delta_stack[i].obj_offset = obj_offset;
1566 delta_stack[i].curpos = curpos;
1567 delta_stack[i].size = size;
1569 curpos = obj_offset = base_offset;
1572 /* PHASE 2: handle the base */
1573 switch (type) {
1574 case OBJ_OFS_DELTA:
1575 case OBJ_REF_DELTA:
1576 if (data)
1577 BUG("unpack_entry: left loop at a valid delta");
1578 break;
1579 case OBJ_COMMIT:
1580 case OBJ_TREE:
1581 case OBJ_BLOB:
1582 case OBJ_TAG:
1583 if (!base_from_cache)
1584 data = unpack_compressed_entry(p, &w_curs, curpos, size);
1585 break;
1586 default:
1587 data = NULL;
1588 error("unknown object type %i at offset %"PRIuMAX" in %s",
1589 type, (uintmax_t)obj_offset, p->pack_name);
1592 /* PHASE 3: apply deltas in order */
1594 /* invariants:
1595 * 'data' holds the base data, or NULL if there was corruption
1597 while (delta_stack_nr) {
1598 void *delta_data;
1599 void *base = data;
1600 void *external_base = NULL;
1601 unsigned long delta_size, base_size = size;
1602 int i;
1604 data = NULL;
1606 if (base)
1607 add_delta_base_cache(p, obj_offset, base, base_size, type);
1609 if (!base) {
1611 * We're probably in deep shit, but let's try to fetch
1612 * the required base anyway from another pack or loose.
1613 * This is costly but should happen only in the presence
1614 * of a corrupted pack, and is better than failing outright.
1616 struct revindex_entry *revidx;
1617 struct object_id base_oid;
1618 revidx = find_pack_revindex(p, obj_offset);
1619 if (revidx) {
1620 nth_packed_object_oid(&base_oid, p, revidx->nr);
1621 error("failed to read delta base object %s"
1622 " at offset %"PRIuMAX" from %s",
1623 oid_to_hex(&base_oid), (uintmax_t)obj_offset,
1624 p->pack_name);
1625 mark_bad_packed_object(p, base_oid.hash);
1626 base = read_object(r, &base_oid, &type, &base_size);
1627 external_base = base;
1631 i = --delta_stack_nr;
1632 obj_offset = delta_stack[i].obj_offset;
1633 curpos = delta_stack[i].curpos;
1634 delta_size = delta_stack[i].size;
1636 if (!base)
1637 continue;
1639 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
1641 if (!delta_data) {
1642 error("failed to unpack compressed delta "
1643 "at offset %"PRIuMAX" from %s",
1644 (uintmax_t)curpos, p->pack_name);
1645 data = NULL;
1646 free(external_base);
1647 continue;
1650 data = patch_delta(base, base_size,
1651 delta_data, delta_size,
1652 &size);
1655 * We could not apply the delta; warn the user, but keep going.
1656 * Our failure will be noticed either in the next iteration of
1657 * the loop, or if this is the final delta, in the caller when
1658 * we return NULL. Those code paths will take care of making
1659 * a more explicit warning and retrying with another copy of
1660 * the object.
1662 if (!data)
1663 error("failed to apply delta");
1665 free(delta_data);
1666 free(external_base);
1669 if (final_type)
1670 *final_type = type;
1671 if (final_size)
1672 *final_size = size;
1674 out:
1675 unuse_pack(&w_curs);
1677 if (delta_stack != small_delta_stack)
1678 free(delta_stack);
1680 return data;
1683 int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
1685 const unsigned char *index_fanout = p->index_data;
1686 const unsigned char *index_lookup;
1687 const unsigned int hashsz = the_hash_algo->rawsz;
1688 int index_lookup_width;
1690 if (!index_fanout)
1691 BUG("bsearch_pack called without a valid pack-index");
1693 index_lookup = index_fanout + 4 * 256;
1694 if (p->index_version == 1) {
1695 index_lookup_width = hashsz + 4;
1696 index_lookup += 4;
1697 } else {
1698 index_lookup_width = hashsz;
1699 index_fanout += 8;
1700 index_lookup += 8;
1703 return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
1704 index_lookup, index_lookup_width, result);
1707 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1708 uint32_t n)
1710 const unsigned char *index = p->index_data;
1711 const unsigned int hashsz = the_hash_algo->rawsz;
1712 if (!index) {
1713 if (open_pack_index(p))
1714 return NULL;
1715 index = p->index_data;
1717 if (n >= p->num_objects)
1718 return NULL;
1719 index += 4 * 256;
1720 if (p->index_version == 1) {
1721 return index + (hashsz + 4) * n + 4;
1722 } else {
1723 index += 8;
1724 return index + hashsz * n;
1728 const struct object_id *nth_packed_object_oid(struct object_id *oid,
1729 struct packed_git *p,
1730 uint32_t n)
1732 const unsigned char *hash = nth_packed_object_sha1(p, n);
1733 if (!hash)
1734 return NULL;
1735 hashcpy(oid->hash, hash);
1736 return oid;
1739 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
1741 const unsigned char *ptr = vptr;
1742 const unsigned char *start = p->index_data;
1743 const unsigned char *end = start + p->index_size;
1744 if (ptr < start)
1745 die(_("offset before start of pack index for %s (corrupt index?)"),
1746 p->pack_name);
1747 /* No need to check for underflow; .idx files must be at least 8 bytes */
1748 if (ptr >= end - 8)
1749 die(_("offset beyond end of pack index for %s (truncated index?)"),
1750 p->pack_name);
1753 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1755 const unsigned char *index = p->index_data;
1756 const unsigned int hashsz = the_hash_algo->rawsz;
1757 index += 4 * 256;
1758 if (p->index_version == 1) {
1759 return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
1760 } else {
1761 uint32_t off;
1762 index += 8 + p->num_objects * (hashsz + 4);
1763 off = ntohl(*((uint32_t *)(index + 4 * n)));
1764 if (!(off & 0x80000000))
1765 return off;
1766 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1767 check_pack_index_ptr(p, index);
1768 return get_be64(index);
1772 off_t find_pack_entry_one(const unsigned char *sha1,
1773 struct packed_git *p)
1775 const unsigned char *index = p->index_data;
1776 struct object_id oid;
1777 uint32_t result;
1779 if (!index) {
1780 if (open_pack_index(p))
1781 return 0;
1784 hashcpy(oid.hash, sha1);
1785 if (bsearch_pack(&oid, p, &result))
1786 return nth_packed_object_offset(p, result);
1787 return 0;
1790 int is_pack_valid(struct packed_git *p)
1792 /* An already open pack is known to be valid. */
1793 if (p->pack_fd != -1)
1794 return 1;
1796 /* If the pack has one window completely covering the
1797 * file size, the pack is known to be valid even if
1798 * the descriptor is not currently open.
1800 if (p->windows) {
1801 struct pack_window *w = p->windows;
1803 if (!w->offset && w->len == p->pack_size)
1804 return 1;
1807 /* Force the pack to open to prove its valid. */
1808 return !open_packed_git(p);
1811 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1812 struct packed_git *packs)
1814 struct packed_git *p;
1816 for (p = packs; p; p = p->next) {
1817 if (find_pack_entry_one(sha1, p))
1818 return p;
1820 return NULL;
1824 static int fill_pack_entry(const struct object_id *oid,
1825 struct pack_entry *e,
1826 struct packed_git *p)
1828 off_t offset;
1830 if (p->num_bad_objects) {
1831 unsigned i;
1832 for (i = 0; i < p->num_bad_objects; i++)
1833 if (!hashcmp(oid->hash,
1834 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1835 return 0;
1838 offset = find_pack_entry_one(oid->hash, p);
1839 if (!offset)
1840 return 0;
1843 * We are about to tell the caller where they can locate the
1844 * requested object. We better make sure the packfile is
1845 * still here and can be accessed before supplying that
1846 * answer, as it may have been deleted since the index was
1847 * loaded!
1849 if (!is_pack_valid(p))
1850 return 0;
1851 e->offset = offset;
1852 e->p = p;
1853 return 1;
1856 int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
1858 struct list_head *pos;
1860 prepare_packed_git(r);
1861 if (!r->objects->packed_git)
1862 return 0;
1864 list_for_each(pos, &r->objects->packed_git_mru) {
1865 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1866 if (fill_pack_entry(oid, e, p)) {
1867 list_move(&p->mru, &r->objects->packed_git_mru);
1868 return 1;
1871 return 0;
1874 int has_object_pack(const struct object_id *oid)
1876 struct pack_entry e;
1877 return find_pack_entry(the_repository, oid, &e);
1880 int has_pack_index(const unsigned char *sha1)
1882 struct stat st;
1883 if (stat(sha1_pack_index_name(sha1), &st))
1884 return 0;
1885 return 1;
1888 int for_each_object_in_pack(struct packed_git *p, each_packed_object_fn cb, void *data)
1890 uint32_t i;
1891 int r = 0;
1893 for (i = 0; i < p->num_objects; i++) {
1894 struct object_id oid;
1896 if (!nth_packed_object_oid(&oid, p, i))
1897 return error("unable to get sha1 of object %u in %s",
1898 i, p->pack_name);
1900 r = cb(&oid, p, i, data);
1901 if (r)
1902 break;
1904 return r;
1907 int for_each_packed_object(each_packed_object_fn cb, void *data, unsigned flags)
1909 struct packed_git *p;
1910 int r = 0;
1911 int pack_errors = 0;
1913 prepare_packed_git(the_repository);
1914 for (p = the_repository->objects->packed_git; p; p = p->next) {
1915 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
1916 continue;
1917 if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
1918 !p->pack_promisor)
1919 continue;
1920 if (open_pack_index(p)) {
1921 pack_errors = 1;
1922 continue;
1924 r = for_each_object_in_pack(p, cb, data);
1925 if (r)
1926 break;
1928 return r ? r : pack_errors;
1931 static int add_promisor_object(const struct object_id *oid,
1932 struct packed_git *pack,
1933 uint32_t pos,
1934 void *set_)
1936 struct oidset *set = set_;
1937 struct object *obj = parse_object(oid);
1938 if (!obj)
1939 return 1;
1941 oidset_insert(set, oid);
1944 * If this is a tree, commit, or tag, the objects it refers
1945 * to are also promisor objects. (Blobs refer to no objects->)
1947 if (obj->type == OBJ_TREE) {
1948 struct tree *tree = (struct tree *)obj;
1949 struct tree_desc desc;
1950 struct name_entry entry;
1951 if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
1953 * Error messages are given when packs are
1954 * verified, so do not print any here.
1956 return 0;
1957 while (tree_entry_gently(&desc, &entry))
1958 oidset_insert(set, entry.oid);
1959 } else if (obj->type == OBJ_COMMIT) {
1960 struct commit *commit = (struct commit *) obj;
1961 struct commit_list *parents = commit->parents;
1963 oidset_insert(set, get_commit_tree_oid(commit));
1964 for (; parents; parents = parents->next)
1965 oidset_insert(set, &parents->item->object.oid);
1966 } else if (obj->type == OBJ_TAG) {
1967 struct tag *tag = (struct tag *) obj;
1968 oidset_insert(set, &tag->tagged->oid);
1970 return 0;
1973 int is_promisor_object(const struct object_id *oid)
1975 static struct oidset promisor_objects;
1976 static int promisor_objects_prepared;
1978 if (!promisor_objects_prepared) {
1979 if (repository_format_partial_clone) {
1980 for_each_packed_object(add_promisor_object,
1981 &promisor_objects,
1982 FOR_EACH_OBJECT_PROMISOR_ONLY);
1984 promisor_objects_prepared = 1;
1986 return oidset_contains(&promisor_objects, oid);