Merge branch 'fc/fetch-with-import-fix' into maint
[git/git.git] / packfile.c
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"
18 #include "midx.h"
19 #include "commit-graph.h"
20
21 char *odb_pack_name(struct strbuf *buf,
22 const unsigned char *sha1,
23 const char *ext)
24 {
25 strbuf_reset(buf);
26 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
27 sha1_to_hex(sha1), ext);
28 return buf->buf;
29 }
30
31 char *sha1_pack_name(const unsigned char *sha1)
32 {
33 static struct strbuf buf = STRBUF_INIT;
34 return odb_pack_name(&buf, sha1, "pack");
35 }
36
37 char *sha1_pack_index_name(const unsigned char *sha1)
38 {
39 static struct strbuf buf = STRBUF_INIT;
40 return odb_pack_name(&buf, sha1, "idx");
41 }
42
43 static unsigned int pack_used_ctr;
44 static unsigned int pack_mmap_calls;
45 static unsigned int peak_pack_open_windows;
46 static unsigned int pack_open_windows;
47 static unsigned int pack_open_fds;
48 static unsigned int pack_max_fds;
49 static size_t peak_pack_mapped;
50 static size_t pack_mapped;
51
52 #define SZ_FMT PRIuMAX
53 static inline uintmax_t sz_fmt(size_t s) { return s; }
54
55 void pack_report(void)
56 {
57 fprintf(stderr,
58 "pack_report: getpagesize() = %10" SZ_FMT "\n"
59 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
60 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
61 sz_fmt(getpagesize()),
62 sz_fmt(packed_git_window_size),
63 sz_fmt(packed_git_limit));
64 fprintf(stderr,
65 "pack_report: pack_used_ctr = %10u\n"
66 "pack_report: pack_mmap_calls = %10u\n"
67 "pack_report: pack_open_windows = %10u / %10u\n"
68 "pack_report: pack_mapped = "
69 "%10" SZ_FMT " / %10" SZ_FMT "\n",
70 pack_used_ctr,
71 pack_mmap_calls,
72 pack_open_windows, peak_pack_open_windows,
73 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
74 }
75
76 /*
77 * Open and mmap the index file at path, perform a couple of
78 * consistency checks, then record its information to p. Return 0 on
79 * success.
80 */
81 static int check_packed_git_idx(const char *path, struct packed_git *p)
82 {
83 void *idx_map;
84 size_t idx_size;
85 int fd = git_open(path), ret;
86 struct stat st;
87 const unsigned int hashsz = the_hash_algo->rawsz;
88
89 if (fd < 0)
90 return -1;
91 if (fstat(fd, &st)) {
92 close(fd);
93 return -1;
94 }
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);
99 }
100 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
101 close(fd);
102
103 ret = load_idx(path, hashsz, idx_map, idx_size, p);
104
105 if (ret)
106 munmap(idx_map, idx_size);
107
108 return ret;
109 }
110
111 int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
112 size_t idx_size, struct packed_git *p)
113 {
114 struct pack_idx_header *hdr = idx_map;
115 uint32_t version, nr, i, *index;
116
117 if (idx_size < 4 * 256 + hashsz + hashsz)
118 return error("index file %s is too small", path);
119 if (idx_map == NULL)
120 return error("empty data");
121
122 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
123 version = ntohl(hdr->idx_version);
124 if (version < 2 || version > 2)
125 return error("index file %s is version %"PRIu32
126 " and is not supported by this binary"
127 " (try upgrading GIT to a newer version)",
128 path, version);
129 } else
130 version = 1;
131
132 nr = 0;
133 index = idx_map;
134 if (version > 1)
135 index += 2; /* skip index header */
136 for (i = 0; i < 256; i++) {
137 uint32_t n = ntohl(index[i]);
138 if (n < nr)
139 return error("non-monotonic index %s", path);
140 nr = n;
141 }
142
143 if (version == 1) {
144 /*
145 * Total size:
146 * - 256 index entries 4 bytes each
147 * - 24-byte entries * nr (object ID + 4-byte offset)
148 * - hash of the packfile
149 * - file checksum
150 */
151 if (idx_size != 4 * 256 + nr * (hashsz + 4) + hashsz + hashsz)
152 return error("wrong index v1 file size in %s", path);
153 } else if (version == 2) {
154 /*
155 * Minimum size:
156 * - 8 bytes of header
157 * - 256 index entries 4 bytes each
158 * - object ID entry * nr
159 * - 4-byte crc entry * nr
160 * - 4-byte offset entry * nr
161 * - hash of the packfile
162 * - file checksum
163 * And after the 4-byte offset table might be a
164 * variable sized table containing 8-byte entries
165 * for offsets larger than 2^31.
166 */
167 unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;
168 unsigned long max_size = min_size;
169 if (nr)
170 max_size += (nr - 1)*8;
171 if (idx_size < min_size || idx_size > max_size)
172 return error("wrong index v2 file size in %s", path);
173 if (idx_size != min_size &&
174 /*
175 * make sure we can deal with large pack offsets.
176 * 31-bit signed offset won't be enough, neither
177 * 32-bit unsigned one will be.
178 */
179 (sizeof(off_t) <= 4))
180 return error("pack too large for current definition of off_t in %s", path);
181 }
182
183 p->index_version = version;
184 p->index_data = idx_map;
185 p->index_size = idx_size;
186 p->num_objects = nr;
187 return 0;
188 }
189
190 int open_pack_index(struct packed_git *p)
191 {
192 char *idx_name;
193 size_t len;
194 int ret;
195
196 if (p->index_data)
197 return 0;
198
199 if (!strip_suffix(p->pack_name, ".pack", &len))
200 BUG("pack_name does not end in .pack");
201 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
202 ret = check_packed_git_idx(idx_name, p);
203 free(idx_name);
204 return ret;
205 }
206
207 uint32_t get_pack_fanout(struct packed_git *p, uint32_t value)
208 {
209 const uint32_t *level1_ofs = p->index_data;
210
211 if (!level1_ofs) {
212 if (open_pack_index(p))
213 return 0;
214 level1_ofs = p->index_data;
215 }
216
217 if (p->index_version > 1) {
218 level1_ofs += 2;
219 }
220
221 return ntohl(level1_ofs[value]);
222 }
223
224 static struct packed_git *alloc_packed_git(int extra)
225 {
226 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
227 memset(p, 0, sizeof(*p));
228 p->pack_fd = -1;
229 return p;
230 }
231
232 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
233 {
234 const char *path = sha1_pack_name(sha1);
235 size_t alloc = st_add(strlen(path), 1);
236 struct packed_git *p = alloc_packed_git(alloc);
237
238 memcpy(p->pack_name, path, alloc); /* includes NUL */
239 hashcpy(p->hash, sha1);
240 if (check_packed_git_idx(idx_path, p)) {
241 free(p);
242 return NULL;
243 }
244
245 return p;
246 }
247
248 static void scan_windows(struct packed_git *p,
249 struct packed_git **lru_p,
250 struct pack_window **lru_w,
251 struct pack_window **lru_l)
252 {
253 struct pack_window *w, *w_l;
254
255 for (w_l = NULL, w = p->windows; w; w = w->next) {
256 if (!w->inuse_cnt) {
257 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
258 *lru_p = p;
259 *lru_w = w;
260 *lru_l = w_l;
261 }
262 }
263 w_l = w;
264 }
265 }
266
267 static int unuse_one_window(struct packed_git *current)
268 {
269 struct packed_git *p, *lru_p = NULL;
270 struct pack_window *lru_w = NULL, *lru_l = NULL;
271
272 if (current)
273 scan_windows(current, &lru_p, &lru_w, &lru_l);
274 for (p = the_repository->objects->packed_git; p; p = p->next)
275 scan_windows(p, &lru_p, &lru_w, &lru_l);
276 if (lru_p) {
277 munmap(lru_w->base, lru_w->len);
278 pack_mapped -= lru_w->len;
279 if (lru_l)
280 lru_l->next = lru_w->next;
281 else
282 lru_p->windows = lru_w->next;
283 free(lru_w);
284 pack_open_windows--;
285 return 1;
286 }
287 return 0;
288 }
289
290 void release_pack_memory(size_t need)
291 {
292 size_t cur = pack_mapped;
293 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
294 ; /* nothing */
295 }
296
297 void close_pack_windows(struct packed_git *p)
298 {
299 while (p->windows) {
300 struct pack_window *w = p->windows;
301
302 if (w->inuse_cnt)
303 die("pack '%s' still has open windows to it",
304 p->pack_name);
305 munmap(w->base, w->len);
306 pack_mapped -= w->len;
307 pack_open_windows--;
308 p->windows = w->next;
309 free(w);
310 }
311 }
312
313 int close_pack_fd(struct packed_git *p)
314 {
315 if (p->pack_fd < 0)
316 return 0;
317
318 close(p->pack_fd);
319 pack_open_fds--;
320 p->pack_fd = -1;
321
322 return 1;
323 }
324
325 void close_pack_index(struct packed_git *p)
326 {
327 if (p->index_data) {
328 munmap((void *)p->index_data, p->index_size);
329 p->index_data = NULL;
330 }
331 }
332
333 void close_pack(struct packed_git *p)
334 {
335 close_pack_windows(p);
336 close_pack_fd(p);
337 close_pack_index(p);
338 }
339
340 void close_object_store(struct raw_object_store *o)
341 {
342 struct packed_git *p;
343
344 for (p = o->packed_git; p; p = p->next)
345 if (p->do_not_close)
346 BUG("want to close pack marked 'do-not-close'");
347 else
348 close_pack(p);
349
350 if (o->multi_pack_index) {
351 close_midx(o->multi_pack_index);
352 o->multi_pack_index = NULL;
353 }
354
355 close_commit_graph(o);
356 }
357
358 /*
359 * The LRU pack is the one with the oldest MRU window, preferring packs
360 * with no used windows, or the oldest mtime if it has no windows allocated.
361 */
362 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
363 {
364 struct pack_window *w, *this_mru_w;
365 int has_windows_inuse = 0;
366
367 /*
368 * Reject this pack if it has windows and the previously selected
369 * one does not. If this pack does not have windows, reject
370 * it if the pack file is newer than the previously selected one.
371 */
372 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
373 return;
374
375 for (w = this_mru_w = p->windows; w; w = w->next) {
376 /*
377 * Reject this pack if any of its windows are in use,
378 * but the previously selected pack did not have any
379 * inuse windows. Otherwise, record that this pack
380 * has windows in use.
381 */
382 if (w->inuse_cnt) {
383 if (*accept_windows_inuse)
384 has_windows_inuse = 1;
385 else
386 return;
387 }
388
389 if (w->last_used > this_mru_w->last_used)
390 this_mru_w = w;
391
392 /*
393 * Reject this pack if it has windows that have been
394 * used more recently than the previously selected pack.
395 * If the previously selected pack had windows inuse and
396 * we have not encountered a window in this pack that is
397 * inuse, skip this check since we prefer a pack with no
398 * inuse windows to one that has inuse windows.
399 */
400 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
401 this_mru_w->last_used > (*mru_w)->last_used)
402 return;
403 }
404
405 /*
406 * Select this pack.
407 */
408 *mru_w = this_mru_w;
409 *lru_p = p;
410 *accept_windows_inuse = has_windows_inuse;
411 }
412
413 static int close_one_pack(void)
414 {
415 struct packed_git *p, *lru_p = NULL;
416 struct pack_window *mru_w = NULL;
417 int accept_windows_inuse = 1;
418
419 for (p = the_repository->objects->packed_git; p; p = p->next) {
420 if (p->pack_fd == -1)
421 continue;
422 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
423 }
424
425 if (lru_p)
426 return close_pack_fd(lru_p);
427
428 return 0;
429 }
430
431 static unsigned int get_max_fd_limit(void)
432 {
433 #ifdef RLIMIT_NOFILE
434 {
435 struct rlimit lim;
436
437 if (!getrlimit(RLIMIT_NOFILE, &lim))
438 return lim.rlim_cur;
439 }
440 #endif
441
442 #ifdef _SC_OPEN_MAX
443 {
444 long open_max = sysconf(_SC_OPEN_MAX);
445 if (0 < open_max)
446 return open_max;
447 /*
448 * Otherwise, we got -1 for one of the two
449 * reasons:
450 *
451 * (1) sysconf() did not understand _SC_OPEN_MAX
452 * and signaled an error with -1; or
453 * (2) sysconf() said there is no limit.
454 *
455 * We _could_ clear errno before calling sysconf() to
456 * tell these two cases apart and return a huge number
457 * in the latter case to let the caller cap it to a
458 * value that is not so selfish, but letting the
459 * fallback OPEN_MAX codepath take care of these cases
460 * is a lot simpler.
461 */
462 }
463 #endif
464
465 #ifdef OPEN_MAX
466 return OPEN_MAX;
467 #else
468 return 1; /* see the caller ;-) */
469 #endif
470 }
471
472 const char *pack_basename(struct packed_git *p)
473 {
474 const char *ret = strrchr(p->pack_name, '/');
475 if (ret)
476 ret = ret + 1; /* skip past slash */
477 else
478 ret = p->pack_name; /* we only have a base */
479 return ret;
480 }
481
482 /*
483 * Do not call this directly as this leaks p->pack_fd on error return;
484 * call open_packed_git() instead.
485 */
486 static int open_packed_git_1(struct packed_git *p)
487 {
488 struct stat st;
489 struct pack_header hdr;
490 unsigned char hash[GIT_MAX_RAWSZ];
491 unsigned char *idx_hash;
492 long fd_flag;
493 ssize_t read_result;
494 const unsigned hashsz = the_hash_algo->rawsz;
495
496 if (!p->index_data) {
497 struct multi_pack_index *m;
498 const char *pack_name = pack_basename(p);
499
500 for (m = the_repository->objects->multi_pack_index;
501 m; m = m->next) {
502 if (midx_contains_pack(m, pack_name))
503 break;
504 }
505
506 if (!m && open_pack_index(p))
507 return error("packfile %s index unavailable", p->pack_name);
508 }
509
510 if (!pack_max_fds) {
511 unsigned int max_fds = get_max_fd_limit();
512
513 /* Save 3 for stdin/stdout/stderr, 22 for work */
514 if (25 < max_fds)
515 pack_max_fds = max_fds - 25;
516 else
517 pack_max_fds = 1;
518 }
519
520 while (pack_max_fds <= pack_open_fds && close_one_pack())
521 ; /* nothing */
522
523 p->pack_fd = git_open(p->pack_name);
524 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
525 return -1;
526 pack_open_fds++;
527
528 /* If we created the struct before we had the pack we lack size. */
529 if (!p->pack_size) {
530 if (!S_ISREG(st.st_mode))
531 return error("packfile %s not a regular file", p->pack_name);
532 p->pack_size = st.st_size;
533 } else if (p->pack_size != st.st_size)
534 return error("packfile %s size changed", p->pack_name);
535
536 /* We leave these file descriptors open with sliding mmap;
537 * there is no point keeping them open across exec(), though.
538 */
539 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
540 if (fd_flag < 0)
541 return error("cannot determine file descriptor flags");
542 fd_flag |= FD_CLOEXEC;
543 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
544 return error("cannot set FD_CLOEXEC");
545
546 /* Verify we recognize this pack file format. */
547 read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
548 if (read_result < 0)
549 return error_errno("error reading from %s", p->pack_name);
550 if (read_result != sizeof(hdr))
551 return error("file %s is far too short to be a packfile", p->pack_name);
552 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
553 return error("file %s is not a GIT packfile", p->pack_name);
554 if (!pack_version_ok(hdr.hdr_version))
555 return error("packfile %s is version %"PRIu32" and not"
556 " supported (try upgrading GIT to a newer version)",
557 p->pack_name, ntohl(hdr.hdr_version));
558
559 /* Skip index checking if in multi-pack-index */
560 if (!p->index_data)
561 return 0;
562
563 /* Verify the pack matches its index. */
564 if (p->num_objects != ntohl(hdr.hdr_entries))
565 return error("packfile %s claims to have %"PRIu32" objects"
566 " while index indicates %"PRIu32" objects",
567 p->pack_name, ntohl(hdr.hdr_entries),
568 p->num_objects);
569 if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1)
570 return error("end of packfile %s is unavailable", p->pack_name);
571 read_result = read_in_full(p->pack_fd, hash, hashsz);
572 if (read_result < 0)
573 return error_errno("error reading from %s", p->pack_name);
574 if (read_result != hashsz)
575 return error("packfile %s signature is unavailable", p->pack_name);
576 idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
577 if (!hasheq(hash, idx_hash))
578 return error("packfile %s does not match index", p->pack_name);
579 return 0;
580 }
581
582 static int open_packed_git(struct packed_git *p)
583 {
584 if (!open_packed_git_1(p))
585 return 0;
586 close_pack_fd(p);
587 return -1;
588 }
589
590 static int in_window(struct pack_window *win, off_t offset)
591 {
592 /* We must promise at least one full hash after the
593 * offset is available from this window, otherwise the offset
594 * is not actually in this window and a different window (which
595 * has that one hash excess) must be used. This is to support
596 * the object header and delta base parsing routines below.
597 */
598 off_t win_off = win->offset;
599 return win_off <= offset
600 && (offset + the_hash_algo->rawsz) <= (win_off + win->len);
601 }
602
603 unsigned char *use_pack(struct packed_git *p,
604 struct pack_window **w_cursor,
605 off_t offset,
606 unsigned long *left)
607 {
608 struct pack_window *win = *w_cursor;
609
610 /* Since packfiles end in a hash of their content and it's
611 * pointless to ask for an offset into the middle of that
612 * hash, and the in_window function above wouldn't match
613 * don't allow an offset too close to the end of the file.
614 */
615 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
616 die("packfile %s cannot be accessed", p->pack_name);
617 if (offset > (p->pack_size - the_hash_algo->rawsz))
618 die("offset beyond end of packfile (truncated pack?)");
619 if (offset < 0)
620 die(_("offset before end of packfile (broken .idx?)"));
621
622 if (!win || !in_window(win, offset)) {
623 if (win)
624 win->inuse_cnt--;
625 for (win = p->windows; win; win = win->next) {
626 if (in_window(win, offset))
627 break;
628 }
629 if (!win) {
630 size_t window_align = packed_git_window_size / 2;
631 off_t len;
632
633 if (p->pack_fd == -1 && open_packed_git(p))
634 die("packfile %s cannot be accessed", p->pack_name);
635
636 win = xcalloc(1, sizeof(*win));
637 win->offset = (offset / window_align) * window_align;
638 len = p->pack_size - win->offset;
639 if (len > packed_git_window_size)
640 len = packed_git_window_size;
641 win->len = (size_t)len;
642 pack_mapped += win->len;
643 while (packed_git_limit < pack_mapped
644 && unuse_one_window(p))
645 ; /* nothing */
646 win->base = xmmap_gently(NULL, win->len,
647 PROT_READ, MAP_PRIVATE,
648 p->pack_fd, win->offset);
649 if (win->base == MAP_FAILED)
650 die_errno("packfile %s cannot be mapped",
651 p->pack_name);
652 if (!win->offset && win->len == p->pack_size
653 && !p->do_not_close)
654 close_pack_fd(p);
655 pack_mmap_calls++;
656 pack_open_windows++;
657 if (pack_mapped > peak_pack_mapped)
658 peak_pack_mapped = pack_mapped;
659 if (pack_open_windows > peak_pack_open_windows)
660 peak_pack_open_windows = pack_open_windows;
661 win->next = p->windows;
662 p->windows = win;
663 }
664 }
665 if (win != *w_cursor) {
666 win->last_used = pack_used_ctr++;
667 win->inuse_cnt++;
668 *w_cursor = win;
669 }
670 offset -= win->offset;
671 if (left)
672 *left = win->len - xsize_t(offset);
673 return win->base + offset;
674 }
675
676 void unuse_pack(struct pack_window **w_cursor)
677 {
678 struct pack_window *w = *w_cursor;
679 if (w) {
680 w->inuse_cnt--;
681 *w_cursor = NULL;
682 }
683 }
684
685 static void try_to_free_pack_memory(size_t size)
686 {
687 release_pack_memory(size);
688 }
689
690 struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
691 {
692 static int have_set_try_to_free_routine;
693 struct stat st;
694 size_t alloc;
695 struct packed_git *p;
696
697 if (!have_set_try_to_free_routine) {
698 have_set_try_to_free_routine = 1;
699 set_try_to_free_routine(try_to_free_pack_memory);
700 }
701
702 /*
703 * Make sure a corresponding .pack file exists and that
704 * the index looks sane.
705 */
706 if (!strip_suffix_mem(path, &path_len, ".idx"))
707 return NULL;
708
709 /*
710 * ".promisor" is long enough to hold any suffix we're adding (and
711 * the use xsnprintf double-checks that)
712 */
713 alloc = st_add3(path_len, strlen(".promisor"), 1);
714 p = alloc_packed_git(alloc);
715 memcpy(p->pack_name, path, path_len);
716
717 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
718 if (!access(p->pack_name, F_OK))
719 p->pack_keep = 1;
720
721 xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
722 if (!access(p->pack_name, F_OK))
723 p->pack_promisor = 1;
724
725 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
726 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
727 free(p);
728 return NULL;
729 }
730
731 /* ok, it looks sane as far as we can check without
732 * actually mapping the pack file.
733 */
734 p->pack_size = st.st_size;
735 p->pack_local = local;
736 p->mtime = st.st_mtime;
737 if (path_len < the_hash_algo->hexsz ||
738 get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->hash))
739 hashclr(p->hash);
740 return p;
741 }
742
743 void install_packed_git(struct repository *r, struct packed_git *pack)
744 {
745 if (pack->pack_fd != -1)
746 pack_open_fds++;
747
748 pack->next = r->objects->packed_git;
749 r->objects->packed_git = pack;
750 }
751
752 void (*report_garbage)(unsigned seen_bits, const char *path);
753
754 static void report_helper(const struct string_list *list,
755 int seen_bits, int first, int last)
756 {
757 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
758 return;
759
760 for (; first < last; first++)
761 report_garbage(seen_bits, list->items[first].string);
762 }
763
764 static void report_pack_garbage(struct string_list *list)
765 {
766 int i, baselen = -1, first = 0, seen_bits = 0;
767
768 if (!report_garbage)
769 return;
770
771 string_list_sort(list);
772
773 for (i = 0; i < list->nr; i++) {
774 const char *path = list->items[i].string;
775 if (baselen != -1 &&
776 strncmp(path, list->items[first].string, baselen)) {
777 report_helper(list, seen_bits, first, i);
778 baselen = -1;
779 seen_bits = 0;
780 }
781 if (baselen == -1) {
782 const char *dot = strrchr(path, '.');
783 if (!dot) {
784 report_garbage(PACKDIR_FILE_GARBAGE, path);
785 continue;
786 }
787 baselen = dot - path + 1;
788 first = i;
789 }
790 if (!strcmp(path + baselen, "pack"))
791 seen_bits |= 1;
792 else if (!strcmp(path + baselen, "idx"))
793 seen_bits |= 2;
794 }
795 report_helper(list, seen_bits, first, list->nr);
796 }
797
798 void for_each_file_in_pack_dir(const char *objdir,
799 each_file_in_pack_dir_fn fn,
800 void *data)
801 {
802 struct strbuf path = STRBUF_INIT;
803 size_t dirnamelen;
804 DIR *dir;
805 struct dirent *de;
806
807 strbuf_addstr(&path, objdir);
808 strbuf_addstr(&path, "/pack");
809 dir = opendir(path.buf);
810 if (!dir) {
811 if (errno != ENOENT)
812 error_errno("unable to open object pack directory: %s",
813 path.buf);
814 strbuf_release(&path);
815 return;
816 }
817 strbuf_addch(&path, '/');
818 dirnamelen = path.len;
819 while ((de = readdir(dir)) != NULL) {
820 if (is_dot_or_dotdot(de->d_name))
821 continue;
822
823 strbuf_setlen(&path, dirnamelen);
824 strbuf_addstr(&path, de->d_name);
825
826 fn(path.buf, path.len, de->d_name, data);
827 }
828
829 closedir(dir);
830 strbuf_release(&path);
831 }
832
833 struct prepare_pack_data {
834 struct repository *r;
835 struct string_list *garbage;
836 int local;
837 struct multi_pack_index *m;
838 };
839
840 static void prepare_pack(const char *full_name, size_t full_name_len,
841 const char *file_name, void *_data)
842 {
843 struct prepare_pack_data *data = (struct prepare_pack_data *)_data;
844 struct packed_git *p;
845 size_t base_len = full_name_len;
846
847 if (strip_suffix_mem(full_name, &base_len, ".idx") &&
848 !(data->m && midx_contains_pack(data->m, file_name))) {
849 /* Don't reopen a pack we already have. */
850 for (p = data->r->objects->packed_git; p; p = p->next) {
851 size_t len;
852 if (strip_suffix(p->pack_name, ".pack", &len) &&
853 len == base_len &&
854 !memcmp(p->pack_name, full_name, len))
855 break;
856 }
857
858 if (!p) {
859 p = add_packed_git(full_name, full_name_len, data->local);
860 if (p)
861 install_packed_git(data->r, p);
862 }
863 }
864
865 if (!report_garbage)
866 return;
867
868 if (!strcmp(file_name, "multi-pack-index"))
869 return;
870 if (ends_with(file_name, ".idx") ||
871 ends_with(file_name, ".pack") ||
872 ends_with(file_name, ".bitmap") ||
873 ends_with(file_name, ".keep") ||
874 ends_with(file_name, ".promisor"))
875 string_list_append(data->garbage, full_name);
876 else
877 report_garbage(PACKDIR_FILE_GARBAGE, full_name);
878 }
879
880 static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
881 {
882 struct prepare_pack_data data;
883 struct string_list garbage = STRING_LIST_INIT_DUP;
884
885 data.m = r->objects->multi_pack_index;
886
887 /* look for the multi-pack-index for this object directory */
888 while (data.m && strcmp(data.m->object_dir, objdir))
889 data.m = data.m->next;
890
891 data.r = r;
892 data.garbage = &garbage;
893 data.local = local;
894
895 for_each_file_in_pack_dir(objdir, prepare_pack, &data);
896
897 report_pack_garbage(data.garbage);
898 string_list_clear(data.garbage, 0);
899 }
900
901 static void prepare_packed_git(struct repository *r);
902 /*
903 * Give a fast, rough count of the number of objects in the repository. This
904 * ignores loose objects completely. If you have a lot of them, then either
905 * you should repack because your performance will be awful, or they are
906 * all unreachable objects about to be pruned, in which case they're not really
907 * interesting as a measure of repo size in the first place.
908 */
909 unsigned long repo_approximate_object_count(struct repository *r)
910 {
911 if (!r->objects->approximate_object_count_valid) {
912 unsigned long count;
913 struct multi_pack_index *m;
914 struct packed_git *p;
915
916 prepare_packed_git(r);
917 count = 0;
918 for (m = get_multi_pack_index(r); m; m = m->next)
919 count += m->num_objects;
920 for (p = r->objects->packed_git; p; p = p->next) {
921 if (open_pack_index(p))
922 continue;
923 count += p->num_objects;
924 }
925 r->objects->approximate_object_count = count;
926 }
927 return r->objects->approximate_object_count;
928 }
929
930 static void *get_next_packed_git(const void *p)
931 {
932 return ((const struct packed_git *)p)->next;
933 }
934
935 static void set_next_packed_git(void *p, void *next)
936 {
937 ((struct packed_git *)p)->next = next;
938 }
939
940 static int sort_pack(const void *a_, const void *b_)
941 {
942 const struct packed_git *a = a_;
943 const struct packed_git *b = b_;
944 int st;
945
946 /*
947 * Local packs tend to contain objects specific to our
948 * variant of the project than remote ones. In addition,
949 * remote ones could be on a network mounted filesystem.
950 * Favor local ones for these reasons.
951 */
952 st = a->pack_local - b->pack_local;
953 if (st)
954 return -st;
955
956 /*
957 * Younger packs tend to contain more recent objects,
958 * and more recent objects tend to get accessed more
959 * often.
960 */
961 if (a->mtime < b->mtime)
962 return 1;
963 else if (a->mtime == b->mtime)
964 return 0;
965 return -1;
966 }
967
968 static void rearrange_packed_git(struct repository *r)
969 {
970 r->objects->packed_git = llist_mergesort(
971 r->objects->packed_git, get_next_packed_git,
972 set_next_packed_git, sort_pack);
973 }
974
975 static void prepare_packed_git_mru(struct repository *r)
976 {
977 struct packed_git *p;
978
979 INIT_LIST_HEAD(&r->objects->packed_git_mru);
980
981 for (p = r->objects->packed_git; p; p = p->next)
982 list_add_tail(&p->mru, &r->objects->packed_git_mru);
983 }
984
985 static void prepare_packed_git(struct repository *r)
986 {
987 struct object_directory *odb;
988
989 if (r->objects->packed_git_initialized)
990 return;
991
992 prepare_alt_odb(r);
993 for (odb = r->objects->odb; odb; odb = odb->next) {
994 int local = (odb == r->objects->odb);
995 prepare_multi_pack_index_one(r, odb->path, local);
996 prepare_packed_git_one(r, odb->path, local);
997 }
998 rearrange_packed_git(r);
999
1000 prepare_packed_git_mru(r);
1001 r->objects->packed_git_initialized = 1;
1002 }
1003
1004 void reprepare_packed_git(struct repository *r)
1005 {
1006 struct object_directory *odb;
1007
1008 for (odb = r->objects->odb; odb; odb = odb->next)
1009 odb_clear_loose_cache(odb);
1010
1011 r->objects->approximate_object_count_valid = 0;
1012 r->objects->packed_git_initialized = 0;
1013 prepare_packed_git(r);
1014 }
1015
1016 struct packed_git *get_packed_git(struct repository *r)
1017 {
1018 prepare_packed_git(r);
1019 return r->objects->packed_git;
1020 }
1021
1022 struct multi_pack_index *get_multi_pack_index(struct repository *r)
1023 {
1024 prepare_packed_git(r);
1025 return r->objects->multi_pack_index;
1026 }
1027
1028 struct packed_git *get_all_packs(struct repository *r)
1029 {
1030 struct multi_pack_index *m;
1031
1032 prepare_packed_git(r);
1033 for (m = r->objects->multi_pack_index; m; m = m->next) {
1034 uint32_t i;
1035 for (i = 0; i < m->num_packs; i++)
1036 prepare_midx_pack(r, m, i);
1037 }
1038
1039 return r->objects->packed_git;
1040 }
1041
1042 struct list_head *get_packed_git_mru(struct repository *r)
1043 {
1044 prepare_packed_git(r);
1045 return &r->objects->packed_git_mru;
1046 }
1047
1048 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1049 unsigned long len, enum object_type *type, unsigned long *sizep)
1050 {
1051 unsigned shift;
1052 unsigned long size, c;
1053 unsigned long used = 0;
1054
1055 c = buf[used++];
1056 *type = (c >> 4) & 7;
1057 size = c & 15;
1058 shift = 4;
1059 while (c & 0x80) {
1060 if (len <= used || bitsizeof(long) <= shift) {
1061 error("bad object header");
1062 size = used = 0;
1063 break;
1064 }
1065 c = buf[used++];
1066 size += (c & 0x7f) << shift;
1067 shift += 7;
1068 }
1069 *sizep = size;
1070 return used;
1071 }
1072
1073 unsigned long get_size_from_delta(struct packed_git *p,
1074 struct pack_window **w_curs,
1075 off_t curpos)
1076 {
1077 const unsigned char *data;
1078 unsigned char delta_head[20], *in;
1079 git_zstream stream;
1080 int st;
1081
1082 memset(&stream, 0, sizeof(stream));
1083 stream.next_out = delta_head;
1084 stream.avail_out = sizeof(delta_head);
1085
1086 git_inflate_init(&stream);
1087 do {
1088 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1089 stream.next_in = in;
1090 st = git_inflate(&stream, Z_FINISH);
1091 curpos += stream.next_in - in;
1092 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1093 stream.total_out < sizeof(delta_head));
1094 git_inflate_end(&stream);
1095 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1096 error("delta data unpack-initial failed");
1097 return 0;
1098 }
1099
1100 /* Examine the initial part of the delta to figure out
1101 * the result size.
1102 */
1103 data = delta_head;
1104
1105 /* ignore base size */
1106 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1107
1108 /* Read the result size */
1109 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1110 }
1111
1112 int unpack_object_header(struct packed_git *p,
1113 struct pack_window **w_curs,
1114 off_t *curpos,
1115 unsigned long *sizep)
1116 {
1117 unsigned char *base;
1118 unsigned long left;
1119 unsigned long used;
1120 enum object_type type;
1121
1122 /* use_pack() assures us we have [base, base + 20) available
1123 * as a range that we can look at. (Its actually the hash
1124 * size that is assured.) With our object header encoding
1125 * the maximum deflated object size is 2^137, which is just
1126 * insane, so we know won't exceed what we have been given.
1127 */
1128 base = use_pack(p, w_curs, *curpos, &left);
1129 used = unpack_object_header_buffer(base, left, &type, sizep);
1130 if (!used) {
1131 type = OBJ_BAD;
1132 } else
1133 *curpos += used;
1134
1135 return type;
1136 }
1137
1138 void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
1139 {
1140 unsigned i;
1141 const unsigned hashsz = the_hash_algo->rawsz;
1142 for (i = 0; i < p->num_bad_objects; i++)
1143 if (hasheq(sha1, p->bad_object_sha1 + hashsz * i))
1144 return;
1145 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1146 st_mult(GIT_MAX_RAWSZ,
1147 st_add(p->num_bad_objects, 1)));
1148 hashcpy(p->bad_object_sha1 + hashsz * p->num_bad_objects, sha1);
1149 p->num_bad_objects++;
1150 }
1151
1152 const struct packed_git *has_packed_and_bad(struct repository *r,
1153 const unsigned char *sha1)
1154 {
1155 struct packed_git *p;
1156 unsigned i;
1157
1158 for (p = r->objects->packed_git; p; p = p->next)
1159 for (i = 0; i < p->num_bad_objects; i++)
1160 if (hasheq(sha1,
1161 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1162 return p;
1163 return NULL;
1164 }
1165
1166 static off_t get_delta_base(struct packed_git *p,
1167 struct pack_window **w_curs,
1168 off_t *curpos,
1169 enum object_type type,
1170 off_t delta_obj_offset)
1171 {
1172 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1173 off_t base_offset;
1174
1175 /* use_pack() assured us we have [base_info, base_info + 20)
1176 * as a range that we can look at without walking off the
1177 * end of the mapped window. Its actually the hash size
1178 * that is assured. An OFS_DELTA longer than the hash size
1179 * is stupid, as then a REF_DELTA would be smaller to store.
1180 */
1181 if (type == OBJ_OFS_DELTA) {
1182 unsigned used = 0;
1183 unsigned char c = base_info[used++];
1184 base_offset = c & 127;
1185 while (c & 128) {
1186 base_offset += 1;
1187 if (!base_offset || MSB(base_offset, 7))
1188 return 0; /* overflow */
1189 c = base_info[used++];
1190 base_offset = (base_offset << 7) + (c & 127);
1191 }
1192 base_offset = delta_obj_offset - base_offset;
1193 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1194 return 0; /* out of bound */
1195 *curpos += used;
1196 } else if (type == OBJ_REF_DELTA) {
1197 /* The base entry _must_ be in the same pack */
1198 base_offset = find_pack_entry_one(base_info, p);
1199 *curpos += the_hash_algo->rawsz;
1200 } else
1201 die("I am totally screwed");
1202 return base_offset;
1203 }
1204
1205 /*
1206 * Like get_delta_base above, but we return the sha1 instead of the pack
1207 * offset. This means it is cheaper for REF deltas (we do not have to do
1208 * the final object lookup), but more expensive for OFS deltas (we
1209 * have to load the revidx to convert the offset back into a sha1).
1210 */
1211 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1212 struct pack_window **w_curs,
1213 off_t curpos,
1214 enum object_type type,
1215 off_t delta_obj_offset)
1216 {
1217 if (type == OBJ_REF_DELTA) {
1218 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1219 return base;
1220 } else if (type == OBJ_OFS_DELTA) {
1221 struct revindex_entry *revidx;
1222 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1223 type, delta_obj_offset);
1224
1225 if (!base_offset)
1226 return NULL;
1227
1228 revidx = find_pack_revindex(p, base_offset);
1229 if (!revidx)
1230 return NULL;
1231
1232 return nth_packed_object_sha1(p, revidx->nr);
1233 } else
1234 return NULL;
1235 }
1236
1237 static int retry_bad_packed_offset(struct repository *r,
1238 struct packed_git *p,
1239 off_t obj_offset)
1240 {
1241 int type;
1242 struct revindex_entry *revidx;
1243 struct object_id oid;
1244 revidx = find_pack_revindex(p, obj_offset);
1245 if (!revidx)
1246 return OBJ_BAD;
1247 nth_packed_object_oid(&oid, p, revidx->nr);
1248 mark_bad_packed_object(p, oid.hash);
1249 type = oid_object_info(r, &oid, NULL);
1250 if (type <= OBJ_NONE)
1251 return OBJ_BAD;
1252 return type;
1253 }
1254
1255 #define POI_STACK_PREALLOC 64
1256
1257 static enum object_type packed_to_object_type(struct repository *r,
1258 struct packed_git *p,
1259 off_t obj_offset,
1260 enum object_type type,
1261 struct pack_window **w_curs,
1262 off_t curpos)
1263 {
1264 off_t small_poi_stack[POI_STACK_PREALLOC];
1265 off_t *poi_stack = small_poi_stack;
1266 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1267
1268 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1269 off_t base_offset;
1270 unsigned long size;
1271 /* Push the object we're going to leave behind */
1272 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1273 poi_stack_alloc = alloc_nr(poi_stack_nr);
1274 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1275 COPY_ARRAY(poi_stack, small_poi_stack, poi_stack_nr);
1276 } else {
1277 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1278 }
1279 poi_stack[poi_stack_nr++] = obj_offset;
1280 /* If parsing the base offset fails, just unwind */
1281 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1282 if (!base_offset)
1283 goto unwind;
1284 curpos = obj_offset = base_offset;
1285 type = unpack_object_header(p, w_curs, &curpos, &size);
1286 if (type <= OBJ_NONE) {
1287 /* If getting the base itself fails, we first
1288 * retry the base, otherwise unwind */
1289 type = retry_bad_packed_offset(r, p, base_offset);
1290 if (type > OBJ_NONE)
1291 goto out;
1292 goto unwind;
1293 }
1294 }
1295
1296 switch (type) {
1297 case OBJ_BAD:
1298 case OBJ_COMMIT:
1299 case OBJ_TREE:
1300 case OBJ_BLOB:
1301 case OBJ_TAG:
1302 break;
1303 default:
1304 error("unknown object type %i at offset %"PRIuMAX" in %s",
1305 type, (uintmax_t)obj_offset, p->pack_name);
1306 type = OBJ_BAD;
1307 }
1308
1309 out:
1310 if (poi_stack != small_poi_stack)
1311 free(poi_stack);
1312 return type;
1313
1314 unwind:
1315 while (poi_stack_nr) {
1316 obj_offset = poi_stack[--poi_stack_nr];
1317 type = retry_bad_packed_offset(r, p, obj_offset);
1318 if (type > OBJ_NONE)
1319 goto out;
1320 }
1321 type = OBJ_BAD;
1322 goto out;
1323 }
1324
1325 static struct hashmap delta_base_cache;
1326 static size_t delta_base_cached;
1327
1328 static LIST_HEAD(delta_base_cache_lru);
1329
1330 struct delta_base_cache_key {
1331 struct packed_git *p;
1332 off_t base_offset;
1333 };
1334
1335 struct delta_base_cache_entry {
1336 struct hashmap hash;
1337 struct delta_base_cache_key key;
1338 struct list_head lru;
1339 void *data;
1340 unsigned long size;
1341 enum object_type type;
1342 };
1343
1344 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
1345 {
1346 unsigned int hash;
1347
1348 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
1349 hash += (hash >> 8) + (hash >> 16);
1350 return hash;
1351 }
1352
1353 static struct delta_base_cache_entry *
1354 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1355 {
1356 struct hashmap_entry entry;
1357 struct delta_base_cache_key key;
1358
1359 if (!delta_base_cache.cmpfn)
1360 return NULL;
1361
1362 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
1363 key.p = p;
1364 key.base_offset = base_offset;
1365 return hashmap_get(&delta_base_cache, &entry, &key);
1366 }
1367
1368 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
1369 const struct delta_base_cache_key *b)
1370 {
1371 return a->p == b->p && a->base_offset == b->base_offset;
1372 }
1373
1374 static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
1375 const void *va, const void *vb,
1376 const void *vkey)
1377 {
1378 const struct delta_base_cache_entry *a = va, *b = vb;
1379 const struct delta_base_cache_key *key = vkey;
1380 if (key)
1381 return !delta_base_cache_key_eq(&a->key, key);
1382 else
1383 return !delta_base_cache_key_eq(&a->key, &b->key);
1384 }
1385
1386 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1387 {
1388 return !!get_delta_base_cache_entry(p, base_offset);
1389 }
1390
1391 /*
1392 * Remove the entry from the cache, but do _not_ free the associated
1393 * entry data. The caller takes ownership of the "data" buffer, and
1394 * should copy out any fields it wants before detaching.
1395 */
1396 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1397 {
1398 hashmap_remove(&delta_base_cache, ent, &ent->key);
1399 list_del(&ent->lru);
1400 delta_base_cached -= ent->size;
1401 free(ent);
1402 }
1403
1404 static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
1405 off_t base_offset, unsigned long *base_size,
1406 enum object_type *type)
1407 {
1408 struct delta_base_cache_entry *ent;
1409
1410 ent = get_delta_base_cache_entry(p, base_offset);
1411 if (!ent)
1412 return unpack_entry(r, p, base_offset, type, base_size);
1413
1414 if (type)
1415 *type = ent->type;
1416 if (base_size)
1417 *base_size = ent->size;
1418 return xmemdupz(ent->data, ent->size);
1419 }
1420
1421 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1422 {
1423 free(ent->data);
1424 detach_delta_base_cache_entry(ent);
1425 }
1426
1427 void clear_delta_base_cache(void)
1428 {
1429 struct list_head *lru, *tmp;
1430 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1431 struct delta_base_cache_entry *entry =
1432 list_entry(lru, struct delta_base_cache_entry, lru);
1433 release_delta_base_cache(entry);
1434 }
1435 }
1436
1437 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1438 void *base, unsigned long base_size, enum object_type type)
1439 {
1440 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
1441 struct list_head *lru, *tmp;
1442
1443 delta_base_cached += base_size;
1444
1445 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1446 struct delta_base_cache_entry *f =
1447 list_entry(lru, struct delta_base_cache_entry, lru);
1448 if (delta_base_cached <= delta_base_cache_limit)
1449 break;
1450 release_delta_base_cache(f);
1451 }
1452
1453 ent->key.p = p;
1454 ent->key.base_offset = base_offset;
1455 ent->type = type;
1456 ent->data = base;
1457 ent->size = base_size;
1458 list_add_tail(&ent->lru, &delta_base_cache_lru);
1459
1460 if (!delta_base_cache.cmpfn)
1461 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
1462 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
1463 hashmap_add(&delta_base_cache, ent);
1464 }
1465
1466 int packed_object_info(struct repository *r, struct packed_git *p,
1467 off_t obj_offset, struct object_info *oi)
1468 {
1469 struct pack_window *w_curs = NULL;
1470 unsigned long size;
1471 off_t curpos = obj_offset;
1472 enum object_type type;
1473
1474 /*
1475 * We always get the representation type, but only convert it to
1476 * a "real" type later if the caller is interested.
1477 */
1478 if (oi->contentp) {
1479 *oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
1480 &type);
1481 if (!*oi->contentp)
1482 type = OBJ_BAD;
1483 } else {
1484 type = unpack_object_header(p, &w_curs, &curpos, &size);
1485 }
1486
1487 if (!oi->contentp && oi->sizep) {
1488 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1489 off_t tmp_pos = curpos;
1490 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1491 type, obj_offset);
1492 if (!base_offset) {
1493 type = OBJ_BAD;
1494 goto out;
1495 }
1496 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1497 if (*oi->sizep == 0) {
1498 type = OBJ_BAD;
1499 goto out;
1500 }
1501 } else {
1502 *oi->sizep = size;
1503 }
1504 }
1505
1506 if (oi->disk_sizep) {
1507 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1508 *oi->disk_sizep = revidx[1].offset - obj_offset;
1509 }
1510
1511 if (oi->typep || oi->type_name) {
1512 enum object_type ptot;
1513 ptot = packed_to_object_type(r, p, obj_offset,
1514 type, &w_curs, curpos);
1515 if (oi->typep)
1516 *oi->typep = ptot;
1517 if (oi->type_name) {
1518 const char *tn = type_name(ptot);
1519 if (tn)
1520 strbuf_addstr(oi->type_name, tn);
1521 }
1522 if (ptot < 0) {
1523 type = OBJ_BAD;
1524 goto out;
1525 }
1526 }
1527
1528 if (oi->delta_base_sha1) {
1529 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1530 const unsigned char *base;
1531
1532 base = get_delta_base_sha1(p, &w_curs, curpos,
1533 type, obj_offset);
1534 if (!base) {
1535 type = OBJ_BAD;
1536 goto out;
1537 }
1538
1539 hashcpy(oi->delta_base_sha1, base);
1540 } else
1541 hashclr(oi->delta_base_sha1);
1542 }
1543
1544 oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
1545 OI_PACKED;
1546
1547 out:
1548 unuse_pack(&w_curs);
1549 return type;
1550 }
1551
1552 static void *unpack_compressed_entry(struct packed_git *p,
1553 struct pack_window **w_curs,
1554 off_t curpos,
1555 unsigned long size)
1556 {
1557 int st;
1558 git_zstream stream;
1559 unsigned char *buffer, *in;
1560
1561 buffer = xmallocz_gently(size);
1562 if (!buffer)
1563 return NULL;
1564 memset(&stream, 0, sizeof(stream));
1565 stream.next_out = buffer;
1566 stream.avail_out = size + 1;
1567
1568 git_inflate_init(&stream);
1569 do {
1570 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1571 stream.next_in = in;
1572 st = git_inflate(&stream, Z_FINISH);
1573 if (!stream.avail_out)
1574 break; /* the payload is larger than it should be */
1575 curpos += stream.next_in - in;
1576 } while (st == Z_OK || st == Z_BUF_ERROR);
1577 git_inflate_end(&stream);
1578 if ((st != Z_STREAM_END) || stream.total_out != size) {
1579 free(buffer);
1580 return NULL;
1581 }
1582
1583 /* versions of zlib can clobber unconsumed portion of outbuf */
1584 buffer[size] = '\0';
1585
1586 return buffer;
1587 }
1588
1589 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1590 {
1591 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
1592 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
1593 p->pack_name, (uintmax_t)obj_offset);
1594 }
1595
1596 int do_check_packed_object_crc;
1597
1598 #define UNPACK_ENTRY_STACK_PREALLOC 64
1599 struct unpack_entry_stack_ent {
1600 off_t obj_offset;
1601 off_t curpos;
1602 unsigned long size;
1603 };
1604
1605 static void *read_object(struct repository *r,
1606 const struct object_id *oid,
1607 enum object_type *type,
1608 unsigned long *size)
1609 {
1610 struct object_info oi = OBJECT_INFO_INIT;
1611 void *content;
1612 oi.typep = type;
1613 oi.sizep = size;
1614 oi.contentp = &content;
1615
1616 if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1617 return NULL;
1618 return content;
1619 }
1620
1621 void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
1622 enum object_type *final_type, unsigned long *final_size)
1623 {
1624 struct pack_window *w_curs = NULL;
1625 off_t curpos = obj_offset;
1626 void *data = NULL;
1627 unsigned long size;
1628 enum object_type type;
1629 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
1630 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
1631 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
1632 int base_from_cache = 0;
1633
1634 write_pack_access_log(p, obj_offset);
1635
1636 /* PHASE 1: drill down to the innermost base object */
1637 for (;;) {
1638 off_t base_offset;
1639 int i;
1640 struct delta_base_cache_entry *ent;
1641
1642 ent = get_delta_base_cache_entry(p, curpos);
1643 if (ent) {
1644 type = ent->type;
1645 data = ent->data;
1646 size = ent->size;
1647 detach_delta_base_cache_entry(ent);
1648 base_from_cache = 1;
1649 break;
1650 }
1651
1652 if (do_check_packed_object_crc && p->index_version > 1) {
1653 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1654 off_t len = revidx[1].offset - obj_offset;
1655 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1656 struct object_id oid;
1657 nth_packed_object_oid(&oid, p, revidx->nr);
1658 error("bad packed object CRC for %s",
1659 oid_to_hex(&oid));
1660 mark_bad_packed_object(p, oid.hash);
1661 data = NULL;
1662 goto out;
1663 }
1664 }
1665
1666 type = unpack_object_header(p, &w_curs, &curpos, &size);
1667 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
1668 break;
1669
1670 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1671 if (!base_offset) {
1672 error("failed to validate delta base reference "
1673 "at offset %"PRIuMAX" from %s",
1674 (uintmax_t)curpos, p->pack_name);
1675 /* bail to phase 2, in hopes of recovery */
1676 data = NULL;
1677 break;
1678 }
1679
1680 /* push object, proceed to base */
1681 if (delta_stack_nr >= delta_stack_alloc
1682 && delta_stack == small_delta_stack) {
1683 delta_stack_alloc = alloc_nr(delta_stack_nr);
1684 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
1685 COPY_ARRAY(delta_stack, small_delta_stack,
1686 delta_stack_nr);
1687 } else {
1688 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
1689 }
1690 i = delta_stack_nr++;
1691 delta_stack[i].obj_offset = obj_offset;
1692 delta_stack[i].curpos = curpos;
1693 delta_stack[i].size = size;
1694
1695 curpos = obj_offset = base_offset;
1696 }
1697
1698 /* PHASE 2: handle the base */
1699 switch (type) {
1700 case OBJ_OFS_DELTA:
1701 case OBJ_REF_DELTA:
1702 if (data)
1703 BUG("unpack_entry: left loop at a valid delta");
1704 break;
1705 case OBJ_COMMIT:
1706 case OBJ_TREE:
1707 case OBJ_BLOB:
1708 case OBJ_TAG:
1709 if (!base_from_cache)
1710 data = unpack_compressed_entry(p, &w_curs, curpos, size);
1711 break;
1712 default:
1713 data = NULL;
1714 error("unknown object type %i at offset %"PRIuMAX" in %s",
1715 type, (uintmax_t)obj_offset, p->pack_name);
1716 }
1717
1718 /* PHASE 3: apply deltas in order */
1719
1720 /* invariants:
1721 * 'data' holds the base data, or NULL if there was corruption
1722 */
1723 while (delta_stack_nr) {
1724 void *delta_data;
1725 void *base = data;
1726 void *external_base = NULL;
1727 unsigned long delta_size, base_size = size;
1728 int i;
1729
1730 data = NULL;
1731
1732 if (base)
1733 add_delta_base_cache(p, obj_offset, base, base_size, type);
1734
1735 if (!base) {
1736 /*
1737 * We're probably in deep shit, but let's try to fetch
1738 * the required base anyway from another pack or loose.
1739 * This is costly but should happen only in the presence
1740 * of a corrupted pack, and is better than failing outright.
1741 */
1742 struct revindex_entry *revidx;
1743 struct object_id base_oid;
1744 revidx = find_pack_revindex(p, obj_offset);
1745 if (revidx) {
1746 nth_packed_object_oid(&base_oid, p, revidx->nr);
1747 error("failed to read delta base object %s"
1748 " at offset %"PRIuMAX" from %s",
1749 oid_to_hex(&base_oid), (uintmax_t)obj_offset,
1750 p->pack_name);
1751 mark_bad_packed_object(p, base_oid.hash);
1752 base = read_object(r, &base_oid, &type, &base_size);
1753 external_base = base;
1754 }
1755 }
1756
1757 i = --delta_stack_nr;
1758 obj_offset = delta_stack[i].obj_offset;
1759 curpos = delta_stack[i].curpos;
1760 delta_size = delta_stack[i].size;
1761
1762 if (!base)
1763 continue;
1764
1765 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
1766
1767 if (!delta_data) {
1768 error("failed to unpack compressed delta "
1769 "at offset %"PRIuMAX" from %s",
1770 (uintmax_t)curpos, p->pack_name);
1771 data = NULL;
1772 free(external_base);
1773 continue;
1774 }
1775
1776 data = patch_delta(base, base_size,
1777 delta_data, delta_size,
1778 &size);
1779
1780 /*
1781 * We could not apply the delta; warn the user, but keep going.
1782 * Our failure will be noticed either in the next iteration of
1783 * the loop, or if this is the final delta, in the caller when
1784 * we return NULL. Those code paths will take care of making
1785 * a more explicit warning and retrying with another copy of
1786 * the object.
1787 */
1788 if (!data)
1789 error("failed to apply delta");
1790
1791 free(delta_data);
1792 free(external_base);
1793 }
1794
1795 if (final_type)
1796 *final_type = type;
1797 if (final_size)
1798 *final_size = size;
1799
1800 out:
1801 unuse_pack(&w_curs);
1802
1803 if (delta_stack != small_delta_stack)
1804 free(delta_stack);
1805
1806 return data;
1807 }
1808
1809 int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
1810 {
1811 const unsigned char *index_fanout = p->index_data;
1812 const unsigned char *index_lookup;
1813 const unsigned int hashsz = the_hash_algo->rawsz;
1814 int index_lookup_width;
1815
1816 if (!index_fanout)
1817 BUG("bsearch_pack called without a valid pack-index");
1818
1819 index_lookup = index_fanout + 4 * 256;
1820 if (p->index_version == 1) {
1821 index_lookup_width = hashsz + 4;
1822 index_lookup += 4;
1823 } else {
1824 index_lookup_width = hashsz;
1825 index_fanout += 8;
1826 index_lookup += 8;
1827 }
1828
1829 return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
1830 index_lookup, index_lookup_width, result);
1831 }
1832
1833 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1834 uint32_t n)
1835 {
1836 const unsigned char *index = p->index_data;
1837 const unsigned int hashsz = the_hash_algo->rawsz;
1838 if (!index) {
1839 if (open_pack_index(p))
1840 return NULL;
1841 index = p->index_data;
1842 }
1843 if (n >= p->num_objects)
1844 return NULL;
1845 index += 4 * 256;
1846 if (p->index_version == 1) {
1847 return index + (hashsz + 4) * n + 4;
1848 } else {
1849 index += 8;
1850 return index + hashsz * n;
1851 }
1852 }
1853
1854 const struct object_id *nth_packed_object_oid(struct object_id *oid,
1855 struct packed_git *p,
1856 uint32_t n)
1857 {
1858 const unsigned char *hash = nth_packed_object_sha1(p, n);
1859 if (!hash)
1860 return NULL;
1861 hashcpy(oid->hash, hash);
1862 return oid;
1863 }
1864
1865 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
1866 {
1867 const unsigned char *ptr = vptr;
1868 const unsigned char *start = p->index_data;
1869 const unsigned char *end = start + p->index_size;
1870 if (ptr < start)
1871 die(_("offset before start of pack index for %s (corrupt index?)"),
1872 p->pack_name);
1873 /* No need to check for underflow; .idx files must be at least 8 bytes */
1874 if (ptr >= end - 8)
1875 die(_("offset beyond end of pack index for %s (truncated index?)"),
1876 p->pack_name);
1877 }
1878
1879 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1880 {
1881 const unsigned char *index = p->index_data;
1882 const unsigned int hashsz = the_hash_algo->rawsz;
1883 index += 4 * 256;
1884 if (p->index_version == 1) {
1885 return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
1886 } else {
1887 uint32_t off;
1888 index += 8 + p->num_objects * (hashsz + 4);
1889 off = ntohl(*((uint32_t *)(index + 4 * n)));
1890 if (!(off & 0x80000000))
1891 return off;
1892 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1893 check_pack_index_ptr(p, index);
1894 return get_be64(index);
1895 }
1896 }
1897
1898 off_t find_pack_entry_one(const unsigned char *sha1,
1899 struct packed_git *p)
1900 {
1901 const unsigned char *index = p->index_data;
1902 struct object_id oid;
1903 uint32_t result;
1904
1905 if (!index) {
1906 if (open_pack_index(p))
1907 return 0;
1908 }
1909
1910 hashcpy(oid.hash, sha1);
1911 if (bsearch_pack(&oid, p, &result))
1912 return nth_packed_object_offset(p, result);
1913 return 0;
1914 }
1915
1916 int is_pack_valid(struct packed_git *p)
1917 {
1918 /* An already open pack is known to be valid. */
1919 if (p->pack_fd != -1)
1920 return 1;
1921
1922 /* If the pack has one window completely covering the
1923 * file size, the pack is known to be valid even if
1924 * the descriptor is not currently open.
1925 */
1926 if (p->windows) {
1927 struct pack_window *w = p->windows;
1928
1929 if (!w->offset && w->len == p->pack_size)
1930 return 1;
1931 }
1932
1933 /* Force the pack to open to prove its valid. */
1934 return !open_packed_git(p);
1935 }
1936
1937 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1938 struct packed_git *packs)
1939 {
1940 struct packed_git *p;
1941
1942 for (p = packs; p; p = p->next) {
1943 if (find_pack_entry_one(sha1, p))
1944 return p;
1945 }
1946 return NULL;
1947
1948 }
1949
1950 static int fill_pack_entry(const struct object_id *oid,
1951 struct pack_entry *e,
1952 struct packed_git *p)
1953 {
1954 off_t offset;
1955
1956 if (p->num_bad_objects) {
1957 unsigned i;
1958 for (i = 0; i < p->num_bad_objects; i++)
1959 if (hasheq(oid->hash,
1960 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1961 return 0;
1962 }
1963
1964 offset = find_pack_entry_one(oid->hash, p);
1965 if (!offset)
1966 return 0;
1967
1968 /*
1969 * We are about to tell the caller where they can locate the
1970 * requested object. We better make sure the packfile is
1971 * still here and can be accessed before supplying that
1972 * answer, as it may have been deleted since the index was
1973 * loaded!
1974 */
1975 if (!is_pack_valid(p))
1976 return 0;
1977 e->offset = offset;
1978 e->p = p;
1979 return 1;
1980 }
1981
1982 int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
1983 {
1984 struct list_head *pos;
1985 struct multi_pack_index *m;
1986
1987 prepare_packed_git(r);
1988 if (!r->objects->packed_git && !r->objects->multi_pack_index)
1989 return 0;
1990
1991 for (m = r->objects->multi_pack_index; m; m = m->next) {
1992 if (fill_midx_entry(r, oid, e, m))
1993 return 1;
1994 }
1995
1996 list_for_each(pos, &r->objects->packed_git_mru) {
1997 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1998 if (!p->multi_pack_index && fill_pack_entry(oid, e, p)) {
1999 list_move(&p->mru, &r->objects->packed_git_mru);
2000 return 1;
2001 }
2002 }
2003 return 0;
2004 }
2005
2006 int has_object_pack(const struct object_id *oid)
2007 {
2008 struct pack_entry e;
2009 return find_pack_entry(the_repository, oid, &e);
2010 }
2011
2012 int has_pack_index(const unsigned char *sha1)
2013 {
2014 struct stat st;
2015 if (stat(sha1_pack_index_name(sha1), &st))
2016 return 0;
2017 return 1;
2018 }
2019
2020 int for_each_object_in_pack(struct packed_git *p,
2021 each_packed_object_fn cb, void *data,
2022 enum for_each_object_flags flags)
2023 {
2024 uint32_t i;
2025 int r = 0;
2026
2027 if (flags & FOR_EACH_OBJECT_PACK_ORDER) {
2028 if (load_pack_revindex(p))
2029 return -1;
2030 }
2031
2032 for (i = 0; i < p->num_objects; i++) {
2033 uint32_t pos;
2034 struct object_id oid;
2035
2036 if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2037 pos = p->revindex[i].nr;
2038 else
2039 pos = i;
2040
2041 if (!nth_packed_object_oid(&oid, p, pos))
2042 return error("unable to get sha1 of object %u in %s",
2043 pos, p->pack_name);
2044
2045 r = cb(&oid, p, pos, data);
2046 if (r)
2047 break;
2048 }
2049 return r;
2050 }
2051
2052 int for_each_packed_object(each_packed_object_fn cb, void *data,
2053 enum for_each_object_flags flags)
2054 {
2055 struct packed_git *p;
2056 int r = 0;
2057 int pack_errors = 0;
2058
2059 prepare_packed_git(the_repository);
2060 for (p = get_all_packs(the_repository); p; p = p->next) {
2061 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
2062 continue;
2063 if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
2064 !p->pack_promisor)
2065 continue;
2066 if (open_pack_index(p)) {
2067 pack_errors = 1;
2068 continue;
2069 }
2070 r = for_each_object_in_pack(p, cb, data, flags);
2071 if (r)
2072 break;
2073 }
2074 return r ? r : pack_errors;
2075 }
2076
2077 static int add_promisor_object(const struct object_id *oid,
2078 struct packed_git *pack,
2079 uint32_t pos,
2080 void *set_)
2081 {
2082 struct oidset *set = set_;
2083 struct object *obj = parse_object(the_repository, oid);
2084 if (!obj)
2085 return 1;
2086
2087 oidset_insert(set, oid);
2088
2089 /*
2090 * If this is a tree, commit, or tag, the objects it refers
2091 * to are also promisor objects. (Blobs refer to no objects->)
2092 */
2093 if (obj->type == OBJ_TREE) {
2094 struct tree *tree = (struct tree *)obj;
2095 struct tree_desc desc;
2096 struct name_entry entry;
2097 if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
2098 /*
2099 * Error messages are given when packs are
2100 * verified, so do not print any here.
2101 */
2102 return 0;
2103 while (tree_entry_gently(&desc, &entry))
2104 oidset_insert(set, &entry.oid);
2105 } else if (obj->type == OBJ_COMMIT) {
2106 struct commit *commit = (struct commit *) obj;
2107 struct commit_list *parents = commit->parents;
2108
2109 oidset_insert(set, get_commit_tree_oid(commit));
2110 for (; parents; parents = parents->next)
2111 oidset_insert(set, &parents->item->object.oid);
2112 } else if (obj->type == OBJ_TAG) {
2113 struct tag *tag = (struct tag *) obj;
2114 oidset_insert(set, &tag->tagged->oid);
2115 }
2116 return 0;
2117 }
2118
2119 int is_promisor_object(const struct object_id *oid)
2120 {
2121 static struct oidset promisor_objects;
2122 static int promisor_objects_prepared;
2123
2124 if (!promisor_objects_prepared) {
2125 if (repository_format_partial_clone) {
2126 for_each_packed_object(add_promisor_object,
2127 &promisor_objects,
2128 FOR_EACH_OBJECT_PROMISOR_ONLY);
2129 }
2130 promisor_objects_prepared = 1;
2131 }
2132 return oidset_contains(&promisor_objects, oid);
2133 }