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Merge branch 'ab/commit-graph-progress-fix'
[git/debian.git] / packfile.c
blob8c6b47cc777708d4f8e450337f2b9d205f43591b
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
20 char *odb_pack_name(struct strbuf *buf,
21 const unsigned char *sha1,
22 const char *ext)
23 {
24 strbuf_reset(buf);
25 strbuf_addf(buf, "%s/pack/pack-%s.%s", get_object_directory(),
26 sha1_to_hex(sha1), ext);
27 return buf->buf;
28 }
29
30 char *sha1_pack_name(const unsigned char *sha1)
31 {
32 static struct strbuf buf = STRBUF_INIT;
33 return odb_pack_name(&buf, sha1, "pack");
34 }
35
36 char *sha1_pack_index_name(const unsigned char *sha1)
37 {
38 static struct strbuf buf = STRBUF_INIT;
39 return odb_pack_name(&buf, sha1, "idx");
40 }
41
42 static unsigned int pack_used_ctr;
43 static unsigned int pack_mmap_calls;
44 static unsigned int peak_pack_open_windows;
45 static unsigned int pack_open_windows;
46 static unsigned int pack_open_fds;
47 static unsigned int pack_max_fds;
48 static size_t peak_pack_mapped;
49 static size_t pack_mapped;
50
51 #define SZ_FMT PRIuMAX
52 static inline uintmax_t sz_fmt(size_t s) { return s; }
53
54 void pack_report(void)
55 {
56 fprintf(stderr,
57 "pack_report: getpagesize() = %10" SZ_FMT "\n"
58 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
59 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
60 sz_fmt(getpagesize()),
61 sz_fmt(packed_git_window_size),
62 sz_fmt(packed_git_limit));
63 fprintf(stderr,
64 "pack_report: pack_used_ctr = %10u\n"
65 "pack_report: pack_mmap_calls = %10u\n"
66 "pack_report: pack_open_windows = %10u / %10u\n"
67 "pack_report: pack_mapped = "
68 "%10" SZ_FMT " / %10" SZ_FMT "\n",
69 pack_used_ctr,
70 pack_mmap_calls,
71 pack_open_windows, peak_pack_open_windows,
72 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
73 }
74
75 /*
76 * Open and mmap the index file at path, perform a couple of
77 * consistency checks, then record its information to p. Return 0 on
78 * success.
79 */
80 static int check_packed_git_idx(const char *path, struct packed_git *p)
81 {
82 void *idx_map;
83 size_t idx_size;
84 int fd = git_open(path), ret;
85 struct stat st;
86 const unsigned int hashsz = the_hash_algo->rawsz;
87
88 if (fd < 0)
89 return -1;
90 if (fstat(fd, &st)) {
91 close(fd);
92 return -1;
93 }
94 idx_size = xsize_t(st.st_size);
95 if (idx_size < 4 * 256 + hashsz + hashsz) {
96 close(fd);
97 return error("index file %s is too small", path);
98 }
99 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
100 close(fd);
101
102 ret = load_idx(path, hashsz, idx_map, idx_size, p);
103
104 if (ret)
105 munmap(idx_map, idx_size);
106
107 return ret;
108 }
109
110 int load_idx(const char *path, const unsigned int hashsz, void *idx_map,
111 size_t idx_size, struct packed_git *p)
112 {
113 struct pack_idx_header *hdr = idx_map;
114 uint32_t version, nr, i, *index;
115
116 if (idx_size < 4 * 256 + hashsz + hashsz)
117 return error("index file %s is too small", path);
118 if (idx_map == NULL)
119 return error("empty data");
120
121 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
122 version = ntohl(hdr->idx_version);
123 if (version < 2 || version > 2)
124 return error("index file %s is version %"PRIu32
125 " and is not supported by this binary"
126 " (try upgrading GIT to a newer version)",
127 path, version);
128 } else
129 version = 1;
130
131 nr = 0;
132 index = idx_map;
133 if (version > 1)
134 index += 2; /* skip index header */
135 for (i = 0; i < 256; i++) {
136 uint32_t n = ntohl(index[i]);
137 if (n < nr)
138 return error("non-monotonic index %s", path);
139 nr = n;
140 }
141
142 if (version == 1) {
143 /*
144 * Total size:
145 * - 256 index entries 4 bytes each
146 * - 24-byte entries * nr (object ID + 4-byte offset)
147 * - hash of the packfile
148 * - file checksum
149 */
150 if (idx_size != 4 * 256 + nr * (hashsz + 4) + hashsz + hashsz)
151 return error("wrong index v1 file size in %s", path);
152 } else if (version == 2) {
153 /*
154 * Minimum size:
155 * - 8 bytes of header
156 * - 256 index entries 4 bytes each
157 * - object ID entry * nr
158 * - 4-byte crc entry * nr
159 * - 4-byte offset entry * nr
160 * - hash of the packfile
161 * - file checksum
162 * And after the 4-byte offset table might be a
163 * variable sized table containing 8-byte entries
164 * for offsets larger than 2^31.
165 */
166 unsigned long min_size = 8 + 4*256 + nr*(hashsz + 4 + 4) + hashsz + hashsz;
167 unsigned long max_size = min_size;
168 if (nr)
169 max_size += (nr - 1)*8;
170 if (idx_size < min_size || idx_size > max_size)
171 return error("wrong index v2 file size in %s", path);
172 if (idx_size != min_size &&
173 /*
174 * make sure we can deal with large pack offsets.
175 * 31-bit signed offset won't be enough, neither
176 * 32-bit unsigned one will be.
177 */
178 (sizeof(off_t) <= 4))
179 return error("pack too large for current definition of off_t in %s", path);
180 }
181
182 p->index_version = version;
183 p->index_data = idx_map;
184 p->index_size = idx_size;
185 p->num_objects = nr;
186 return 0;
187 }
188
189 int open_pack_index(struct packed_git *p)
190 {
191 char *idx_name;
192 size_t len;
193 int ret;
194
195 if (p->index_data)
196 return 0;
197
198 if (!strip_suffix(p->pack_name, ".pack", &len))
199 BUG("pack_name does not end in .pack");
200 idx_name = xstrfmt("%.*s.idx", (int)len, p->pack_name);
201 ret = check_packed_git_idx(idx_name, p);
202 free(idx_name);
203 return ret;
204 }
205
206 uint32_t get_pack_fanout(struct packed_git *p, uint32_t value)
207 {
208 const uint32_t *level1_ofs = p->index_data;
209
210 if (!level1_ofs) {
211 if (open_pack_index(p))
212 return 0;
213 level1_ofs = p->index_data;
214 }
215
216 if (p->index_version > 1) {
217 level1_ofs += 2;
218 }
219
220 return ntohl(level1_ofs[value]);
221 }
222
223 static struct packed_git *alloc_packed_git(int extra)
224 {
225 struct packed_git *p = xmalloc(st_add(sizeof(*p), extra));
226 memset(p, 0, sizeof(*p));
227 p->pack_fd = -1;
228 return p;
229 }
230
231 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
232 {
233 const char *path = sha1_pack_name(sha1);
234 size_t alloc = st_add(strlen(path), 1);
235 struct packed_git *p = alloc_packed_git(alloc);
236
237 memcpy(p->pack_name, path, alloc); /* includes NUL */
238 hashcpy(p->sha1, sha1);
239 if (check_packed_git_idx(idx_path, p)) {
240 free(p);
241 return NULL;
242 }
243
244 return p;
245 }
246
247 static void scan_windows(struct packed_git *p,
248 struct packed_git **lru_p,
249 struct pack_window **lru_w,
250 struct pack_window **lru_l)
251 {
252 struct pack_window *w, *w_l;
253
254 for (w_l = NULL, w = p->windows; w; w = w->next) {
255 if (!w->inuse_cnt) {
256 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
257 *lru_p = p;
258 *lru_w = w;
259 *lru_l = w_l;
260 }
261 }
262 w_l = w;
263 }
264 }
265
266 static int unuse_one_window(struct packed_git *current)
267 {
268 struct packed_git *p, *lru_p = NULL;
269 struct pack_window *lru_w = NULL, *lru_l = NULL;
270
271 if (current)
272 scan_windows(current, &lru_p, &lru_w, &lru_l);
273 for (p = the_repository->objects->packed_git; p; p = p->next)
274 scan_windows(p, &lru_p, &lru_w, &lru_l);
275 if (lru_p) {
276 munmap(lru_w->base, lru_w->len);
277 pack_mapped -= lru_w->len;
278 if (lru_l)
279 lru_l->next = lru_w->next;
280 else
281 lru_p->windows = lru_w->next;
282 free(lru_w);
283 pack_open_windows--;
284 return 1;
285 }
286 return 0;
287 }
288
289 void release_pack_memory(size_t need)
290 {
291 size_t cur = pack_mapped;
292 while (need >= (cur - pack_mapped) && unuse_one_window(NULL))
293 ; /* nothing */
294 }
295
296 void close_pack_windows(struct packed_git *p)
297 {
298 while (p->windows) {
299 struct pack_window *w = p->windows;
300
301 if (w->inuse_cnt)
302 die("pack '%s' still has open windows to it",
303 p->pack_name);
304 munmap(w->base, w->len);
305 pack_mapped -= w->len;
306 pack_open_windows--;
307 p->windows = w->next;
308 free(w);
309 }
310 }
311
312 static int close_pack_fd(struct packed_git *p)
313 {
314 if (p->pack_fd < 0)
315 return 0;
316
317 close(p->pack_fd);
318 pack_open_fds--;
319 p->pack_fd = -1;
320
321 return 1;
322 }
323
324 void close_pack_index(struct packed_git *p)
325 {
326 if (p->index_data) {
327 munmap((void *)p->index_data, p->index_size);
328 p->index_data = NULL;
329 }
330 }
331
332 void close_pack(struct packed_git *p)
333 {
334 close_pack_windows(p);
335 close_pack_fd(p);
336 close_pack_index(p);
337 }
338
339 void close_all_packs(struct raw_object_store *o)
340 {
341 struct packed_git *p;
342
343 for (p = o->packed_git; p; p = p->next)
344 if (p->do_not_close)
345 BUG("want to close pack marked 'do-not-close'");
346 else
347 close_pack(p);
348
349 if (o->multi_pack_index) {
350 close_midx(o->multi_pack_index);
351 o->multi_pack_index = NULL;
352 }
353 }
354
355 /*
356 * The LRU pack is the one with the oldest MRU window, preferring packs
357 * with no used windows, or the oldest mtime if it has no windows allocated.
358 */
359 static void find_lru_pack(struct packed_git *p, struct packed_git **lru_p, struct pack_window **mru_w, int *accept_windows_inuse)
360 {
361 struct pack_window *w, *this_mru_w;
362 int has_windows_inuse = 0;
363
364 /*
365 * Reject this pack if it has windows and the previously selected
366 * one does not. If this pack does not have windows, reject
367 * it if the pack file is newer than the previously selected one.
368 */
369 if (*lru_p && !*mru_w && (p->windows || p->mtime > (*lru_p)->mtime))
370 return;
371
372 for (w = this_mru_w = p->windows; w; w = w->next) {
373 /*
374 * Reject this pack if any of its windows are in use,
375 * but the previously selected pack did not have any
376 * inuse windows. Otherwise, record that this pack
377 * has windows in use.
378 */
379 if (w->inuse_cnt) {
380 if (*accept_windows_inuse)
381 has_windows_inuse = 1;
382 else
383 return;
384 }
385
386 if (w->last_used > this_mru_w->last_used)
387 this_mru_w = w;
388
389 /*
390 * Reject this pack if it has windows that have been
391 * used more recently than the previously selected pack.
392 * If the previously selected pack had windows inuse and
393 * we have not encountered a window in this pack that is
394 * inuse, skip this check since we prefer a pack with no
395 * inuse windows to one that has inuse windows.
396 */
397 if (*mru_w && *accept_windows_inuse == has_windows_inuse &&
398 this_mru_w->last_used > (*mru_w)->last_used)
399 return;
400 }
401
402 /*
403 * Select this pack.
404 */
405 *mru_w = this_mru_w;
406 *lru_p = p;
407 *accept_windows_inuse = has_windows_inuse;
408 }
409
410 static int close_one_pack(void)
411 {
412 struct packed_git *p, *lru_p = NULL;
413 struct pack_window *mru_w = NULL;
414 int accept_windows_inuse = 1;
415
416 for (p = the_repository->objects->packed_git; p; p = p->next) {
417 if (p->pack_fd == -1)
418 continue;
419 find_lru_pack(p, &lru_p, &mru_w, &accept_windows_inuse);
420 }
421
422 if (lru_p)
423 return close_pack_fd(lru_p);
424
425 return 0;
426 }
427
428 static unsigned int get_max_fd_limit(void)
429 {
430 #ifdef RLIMIT_NOFILE
431 {
432 struct rlimit lim;
433
434 if (!getrlimit(RLIMIT_NOFILE, &lim))
435 return lim.rlim_cur;
436 }
437 #endif
438
439 #ifdef _SC_OPEN_MAX
440 {
441 long open_max = sysconf(_SC_OPEN_MAX);
442 if (0 < open_max)
443 return open_max;
444 /*
445 * Otherwise, we got -1 for one of the two
446 * reasons:
447 *
448 * (1) sysconf() did not understand _SC_OPEN_MAX
449 * and signaled an error with -1; or
450 * (2) sysconf() said there is no limit.
451 *
452 * We _could_ clear errno before calling sysconf() to
453 * tell these two cases apart and return a huge number
454 * in the latter case to let the caller cap it to a
455 * value that is not so selfish, but letting the
456 * fallback OPEN_MAX codepath take care of these cases
457 * is a lot simpler.
458 */
459 }
460 #endif
461
462 #ifdef OPEN_MAX
463 return OPEN_MAX;
464 #else
465 return 1; /* see the caller ;-) */
466 #endif
467 }
468
469 /*
470 * Do not call this directly as this leaks p->pack_fd on error return;
471 * call open_packed_git() instead.
472 */
473 static int open_packed_git_1(struct packed_git *p)
474 {
475 struct stat st;
476 struct pack_header hdr;
477 unsigned char hash[GIT_MAX_RAWSZ];
478 unsigned char *idx_hash;
479 long fd_flag;
480 ssize_t read_result;
481 const unsigned hashsz = the_hash_algo->rawsz;
482
483 if (!p->index_data) {
484 struct multi_pack_index *m;
485 const char *pack_name = strrchr(p->pack_name, '/');
486
487 for (m = the_repository->objects->multi_pack_index;
488 m; m = m->next) {
489 if (midx_contains_pack(m, pack_name))
490 break;
491 }
492
493 if (!m && open_pack_index(p))
494 return error("packfile %s index unavailable", p->pack_name);
495 }
496
497 if (!pack_max_fds) {
498 unsigned int max_fds = get_max_fd_limit();
499
500 /* Save 3 for stdin/stdout/stderr, 22 for work */
501 if (25 < max_fds)
502 pack_max_fds = max_fds - 25;
503 else
504 pack_max_fds = 1;
505 }
506
507 while (pack_max_fds <= pack_open_fds && close_one_pack())
508 ; /* nothing */
509
510 p->pack_fd = git_open(p->pack_name);
511 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
512 return -1;
513 pack_open_fds++;
514
515 /* If we created the struct before we had the pack we lack size. */
516 if (!p->pack_size) {
517 if (!S_ISREG(st.st_mode))
518 return error("packfile %s not a regular file", p->pack_name);
519 p->pack_size = st.st_size;
520 } else if (p->pack_size != st.st_size)
521 return error("packfile %s size changed", p->pack_name);
522
523 /* We leave these file descriptors open with sliding mmap;
524 * there is no point keeping them open across exec(), though.
525 */
526 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
527 if (fd_flag < 0)
528 return error("cannot determine file descriptor flags");
529 fd_flag |= FD_CLOEXEC;
530 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
531 return error("cannot set FD_CLOEXEC");
532
533 /* Verify we recognize this pack file format. */
534 read_result = read_in_full(p->pack_fd, &hdr, sizeof(hdr));
535 if (read_result < 0)
536 return error_errno("error reading from %s", p->pack_name);
537 if (read_result != sizeof(hdr))
538 return error("file %s is far too short to be a packfile", p->pack_name);
539 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
540 return error("file %s is not a GIT packfile", p->pack_name);
541 if (!pack_version_ok(hdr.hdr_version))
542 return error("packfile %s is version %"PRIu32" and not"
543 " supported (try upgrading GIT to a newer version)",
544 p->pack_name, ntohl(hdr.hdr_version));
545
546 /* Skip index checking if in multi-pack-index */
547 if (!p->index_data)
548 return 0;
549
550 /* Verify the pack matches its index. */
551 if (p->num_objects != ntohl(hdr.hdr_entries))
552 return error("packfile %s claims to have %"PRIu32" objects"
553 " while index indicates %"PRIu32" objects",
554 p->pack_name, ntohl(hdr.hdr_entries),
555 p->num_objects);
556 if (lseek(p->pack_fd, p->pack_size - hashsz, SEEK_SET) == -1)
557 return error("end of packfile %s is unavailable", p->pack_name);
558 read_result = read_in_full(p->pack_fd, hash, hashsz);
559 if (read_result < 0)
560 return error_errno("error reading from %s", p->pack_name);
561 if (read_result != hashsz)
562 return error("packfile %s signature is unavailable", p->pack_name);
563 idx_hash = ((unsigned char *)p->index_data) + p->index_size - hashsz * 2;
564 if (!hasheq(hash, idx_hash))
565 return error("packfile %s does not match index", p->pack_name);
566 return 0;
567 }
568
569 static int open_packed_git(struct packed_git *p)
570 {
571 if (!open_packed_git_1(p))
572 return 0;
573 close_pack_fd(p);
574 return -1;
575 }
576
577 static int in_window(struct pack_window *win, off_t offset)
578 {
579 /* We must promise at least one full hash after the
580 * offset is available from this window, otherwise the offset
581 * is not actually in this window and a different window (which
582 * has that one hash excess) must be used. This is to support
583 * the object header and delta base parsing routines below.
584 */
585 off_t win_off = win->offset;
586 return win_off <= offset
587 && (offset + the_hash_algo->rawsz) <= (win_off + win->len);
588 }
589
590 unsigned char *use_pack(struct packed_git *p,
591 struct pack_window **w_cursor,
592 off_t offset,
593 unsigned long *left)
594 {
595 struct pack_window *win = *w_cursor;
596
597 /* Since packfiles end in a hash of their content and it's
598 * pointless to ask for an offset into the middle of that
599 * hash, and the in_window function above wouldn't match
600 * don't allow an offset too close to the end of the file.
601 */
602 if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p))
603 die("packfile %s cannot be accessed", p->pack_name);
604 if (offset > (p->pack_size - the_hash_algo->rawsz))
605 die("offset beyond end of packfile (truncated pack?)");
606 if (offset < 0)
607 die(_("offset before end of packfile (broken .idx?)"));
608
609 if (!win || !in_window(win, offset)) {
610 if (win)
611 win->inuse_cnt--;
612 for (win = p->windows; win; win = win->next) {
613 if (in_window(win, offset))
614 break;
615 }
616 if (!win) {
617 size_t window_align = packed_git_window_size / 2;
618 off_t len;
619
620 if (p->pack_fd == -1 && open_packed_git(p))
621 die("packfile %s cannot be accessed", p->pack_name);
622
623 win = xcalloc(1, sizeof(*win));
624 win->offset = (offset / window_align) * window_align;
625 len = p->pack_size - win->offset;
626 if (len > packed_git_window_size)
627 len = packed_git_window_size;
628 win->len = (size_t)len;
629 pack_mapped += win->len;
630 while (packed_git_limit < pack_mapped
631 && unuse_one_window(p))
632 ; /* nothing */
633 win->base = xmmap(NULL, win->len,
634 PROT_READ, MAP_PRIVATE,
635 p->pack_fd, win->offset);
636 if (win->base == MAP_FAILED)
637 die_errno("packfile %s cannot be mapped",
638 p->pack_name);
639 if (!win->offset && win->len == p->pack_size
640 && !p->do_not_close)
641 close_pack_fd(p);
642 pack_mmap_calls++;
643 pack_open_windows++;
644 if (pack_mapped > peak_pack_mapped)
645 peak_pack_mapped = pack_mapped;
646 if (pack_open_windows > peak_pack_open_windows)
647 peak_pack_open_windows = pack_open_windows;
648 win->next = p->windows;
649 p->windows = win;
650 }
651 }
652 if (win != *w_cursor) {
653 win->last_used = pack_used_ctr++;
654 win->inuse_cnt++;
655 *w_cursor = win;
656 }
657 offset -= win->offset;
658 if (left)
659 *left = win->len - xsize_t(offset);
660 return win->base + offset;
661 }
662
663 void unuse_pack(struct pack_window **w_cursor)
664 {
665 struct pack_window *w = *w_cursor;
666 if (w) {
667 w->inuse_cnt--;
668 *w_cursor = NULL;
669 }
670 }
671
672 static void try_to_free_pack_memory(size_t size)
673 {
674 release_pack_memory(size);
675 }
676
677 struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
678 {
679 static int have_set_try_to_free_routine;
680 struct stat st;
681 size_t alloc;
682 struct packed_git *p;
683
684 if (!have_set_try_to_free_routine) {
685 have_set_try_to_free_routine = 1;
686 set_try_to_free_routine(try_to_free_pack_memory);
687 }
688
689 /*
690 * Make sure a corresponding .pack file exists and that
691 * the index looks sane.
692 */
693 if (!strip_suffix_mem(path, &path_len, ".idx"))
694 return NULL;
695
696 /*
697 * ".promisor" is long enough to hold any suffix we're adding (and
698 * the use xsnprintf double-checks that)
699 */
700 alloc = st_add3(path_len, strlen(".promisor"), 1);
701 p = alloc_packed_git(alloc);
702 memcpy(p->pack_name, path, path_len);
703
704 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
705 if (!access(p->pack_name, F_OK))
706 p->pack_keep = 1;
707
708 xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
709 if (!access(p->pack_name, F_OK))
710 p->pack_promisor = 1;
711
712 xsnprintf(p->pack_name + path_len, alloc - path_len, ".pack");
713 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
714 free(p);
715 return NULL;
716 }
717
718 /* ok, it looks sane as far as we can check without
719 * actually mapping the pack file.
720 */
721 p->pack_size = st.st_size;
722 p->pack_local = local;
723 p->mtime = st.st_mtime;
724 if (path_len < the_hash_algo->hexsz ||
725 get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->sha1))
726 hashclr(p->sha1);
727 return p;
728 }
729
730 void install_packed_git(struct repository *r, struct packed_git *pack)
731 {
732 if (pack->pack_fd != -1)
733 pack_open_fds++;
734
735 pack->next = r->objects->packed_git;
736 r->objects->packed_git = pack;
737 }
738
739 void (*report_garbage)(unsigned seen_bits, const char *path);
740
741 static void report_helper(const struct string_list *list,
742 int seen_bits, int first, int last)
743 {
744 if (seen_bits == (PACKDIR_FILE_PACK|PACKDIR_FILE_IDX))
745 return;
746
747 for (; first < last; first++)
748 report_garbage(seen_bits, list->items[first].string);
749 }
750
751 static void report_pack_garbage(struct string_list *list)
752 {
753 int i, baselen = -1, first = 0, seen_bits = 0;
754
755 if (!report_garbage)
756 return;
757
758 string_list_sort(list);
759
760 for (i = 0; i < list->nr; i++) {
761 const char *path = list->items[i].string;
762 if (baselen != -1 &&
763 strncmp(path, list->items[first].string, baselen)) {
764 report_helper(list, seen_bits, first, i);
765 baselen = -1;
766 seen_bits = 0;
767 }
768 if (baselen == -1) {
769 const char *dot = strrchr(path, '.');
770 if (!dot) {
771 report_garbage(PACKDIR_FILE_GARBAGE, path);
772 continue;
773 }
774 baselen = dot - path + 1;
775 first = i;
776 }
777 if (!strcmp(path + baselen, "pack"))
778 seen_bits |= 1;
779 else if (!strcmp(path + baselen, "idx"))
780 seen_bits |= 2;
781 }
782 report_helper(list, seen_bits, first, list->nr);
783 }
784
785 void for_each_file_in_pack_dir(const char *objdir,
786 each_file_in_pack_dir_fn fn,
787 void *data)
788 {
789 struct strbuf path = STRBUF_INIT;
790 size_t dirnamelen;
791 DIR *dir;
792 struct dirent *de;
793
794 strbuf_addstr(&path, objdir);
795 strbuf_addstr(&path, "/pack");
796 dir = opendir(path.buf);
797 if (!dir) {
798 if (errno != ENOENT)
799 error_errno("unable to open object pack directory: %s",
800 path.buf);
801 strbuf_release(&path);
802 return;
803 }
804 strbuf_addch(&path, '/');
805 dirnamelen = path.len;
806 while ((de = readdir(dir)) != NULL) {
807 if (is_dot_or_dotdot(de->d_name))
808 continue;
809
810 strbuf_setlen(&path, dirnamelen);
811 strbuf_addstr(&path, de->d_name);
812
813 fn(path.buf, path.len, de->d_name, data);
814 }
815
816 closedir(dir);
817 strbuf_release(&path);
818 }
819
820 struct prepare_pack_data {
821 struct repository *r;
822 struct string_list *garbage;
823 int local;
824 struct multi_pack_index *m;
825 };
826
827 static void prepare_pack(const char *full_name, size_t full_name_len,
828 const char *file_name, void *_data)
829 {
830 struct prepare_pack_data *data = (struct prepare_pack_data *)_data;
831 struct packed_git *p;
832 size_t base_len = full_name_len;
833
834 if (strip_suffix_mem(full_name, &base_len, ".idx") &&
835 !(data->m && midx_contains_pack(data->m, file_name))) {
836 /* Don't reopen a pack we already have. */
837 for (p = data->r->objects->packed_git; p; p = p->next) {
838 size_t len;
839 if (strip_suffix(p->pack_name, ".pack", &len) &&
840 len == base_len &&
841 !memcmp(p->pack_name, full_name, len))
842 break;
843 }
844
845 if (!p) {
846 p = add_packed_git(full_name, full_name_len, data->local);
847 if (p)
848 install_packed_git(data->r, p);
849 }
850 }
851
852 if (!report_garbage)
853 return;
854
855 if (!strcmp(file_name, "multi-pack-index"))
856 return;
857 if (ends_with(file_name, ".idx") ||
858 ends_with(file_name, ".pack") ||
859 ends_with(file_name, ".bitmap") ||
860 ends_with(file_name, ".keep") ||
861 ends_with(file_name, ".promisor"))
862 string_list_append(data->garbage, full_name);
863 else
864 report_garbage(PACKDIR_FILE_GARBAGE, full_name);
865 }
866
867 static void prepare_packed_git_one(struct repository *r, char *objdir, int local)
868 {
869 struct prepare_pack_data data;
870 struct string_list garbage = STRING_LIST_INIT_DUP;
871
872 data.m = r->objects->multi_pack_index;
873
874 /* look for the multi-pack-index for this object directory */
875 while (data.m && strcmp(data.m->object_dir, objdir))
876 data.m = data.m->next;
877
878 data.r = r;
879 data.garbage = &garbage;
880 data.local = local;
881
882 for_each_file_in_pack_dir(objdir, prepare_pack, &data);
883
884 report_pack_garbage(data.garbage);
885 string_list_clear(data.garbage, 0);
886 }
887
888 static void prepare_packed_git(struct repository *r);
889 /*
890 * Give a fast, rough count of the number of objects in the repository. This
891 * ignores loose objects completely. If you have a lot of them, then either
892 * you should repack because your performance will be awful, or they are
893 * all unreachable objects about to be pruned, in which case they're not really
894 * interesting as a measure of repo size in the first place.
895 */
896 unsigned long approximate_object_count(void)
897 {
898 if (!the_repository->objects->approximate_object_count_valid) {
899 unsigned long count;
900 struct multi_pack_index *m;
901 struct packed_git *p;
902
903 prepare_packed_git(the_repository);
904 count = 0;
905 for (m = get_multi_pack_index(the_repository); m; m = m->next)
906 count += m->num_objects;
907 for (p = the_repository->objects->packed_git; p; p = p->next) {
908 if (open_pack_index(p))
909 continue;
910 count += p->num_objects;
911 }
912 the_repository->objects->approximate_object_count = count;
913 }
914 return the_repository->objects->approximate_object_count;
915 }
916
917 static void *get_next_packed_git(const void *p)
918 {
919 return ((const struct packed_git *)p)->next;
920 }
921
922 static void set_next_packed_git(void *p, void *next)
923 {
924 ((struct packed_git *)p)->next = next;
925 }
926
927 static int sort_pack(const void *a_, const void *b_)
928 {
929 const struct packed_git *a = a_;
930 const struct packed_git *b = b_;
931 int st;
932
933 /*
934 * Local packs tend to contain objects specific to our
935 * variant of the project than remote ones. In addition,
936 * remote ones could be on a network mounted filesystem.
937 * Favor local ones for these reasons.
938 */
939 st = a->pack_local - b->pack_local;
940 if (st)
941 return -st;
942
943 /*
944 * Younger packs tend to contain more recent objects,
945 * and more recent objects tend to get accessed more
946 * often.
947 */
948 if (a->mtime < b->mtime)
949 return 1;
950 else if (a->mtime == b->mtime)
951 return 0;
952 return -1;
953 }
954
955 static void rearrange_packed_git(struct repository *r)
956 {
957 r->objects->packed_git = llist_mergesort(
958 r->objects->packed_git, get_next_packed_git,
959 set_next_packed_git, sort_pack);
960 }
961
962 static void prepare_packed_git_mru(struct repository *r)
963 {
964 struct packed_git *p;
965
966 INIT_LIST_HEAD(&r->objects->packed_git_mru);
967
968 for (p = r->objects->packed_git; p; p = p->next)
969 list_add_tail(&p->mru, &r->objects->packed_git_mru);
970 }
971
972 static void prepare_packed_git(struct repository *r)
973 {
974 struct object_directory *odb;
975
976 if (r->objects->packed_git_initialized)
977 return;
978
979 prepare_alt_odb(r);
980 for (odb = r->objects->odb; odb; odb = odb->next) {
981 int local = (odb == r->objects->odb);
982 prepare_multi_pack_index_one(r, odb->path, local);
983 prepare_packed_git_one(r, odb->path, local);
984 }
985 rearrange_packed_git(r);
986
987 r->objects->all_packs = NULL;
988
989 prepare_packed_git_mru(r);
990 r->objects->packed_git_initialized = 1;
991 }
992
993 void reprepare_packed_git(struct repository *r)
994 {
995 struct object_directory *odb;
996
997 for (odb = r->objects->odb; odb; odb = odb->next) {
998 oid_array_clear(&odb->loose_objects_cache);
999 memset(&odb->loose_objects_subdir_seen, 0,
1000 sizeof(odb->loose_objects_subdir_seen));
1001 }
1002
1003 r->objects->approximate_object_count_valid = 0;
1004 r->objects->packed_git_initialized = 0;
1005 prepare_packed_git(r);
1006 }
1007
1008 struct packed_git *get_packed_git(struct repository *r)
1009 {
1010 prepare_packed_git(r);
1011 return r->objects->packed_git;
1012 }
1013
1014 struct multi_pack_index *get_multi_pack_index(struct repository *r)
1015 {
1016 prepare_packed_git(r);
1017 return r->objects->multi_pack_index;
1018 }
1019
1020 struct packed_git *get_all_packs(struct repository *r)
1021 {
1022 prepare_packed_git(r);
1023
1024 if (!r->objects->all_packs) {
1025 struct packed_git *p = r->objects->packed_git;
1026 struct multi_pack_index *m;
1027
1028 for (m = r->objects->multi_pack_index; m; m = m->next) {
1029 uint32_t i;
1030 for (i = 0; i < m->num_packs; i++) {
1031 if (!prepare_midx_pack(m, i)) {
1032 m->packs[i]->next = p;
1033 p = m->packs[i];
1034 }
1035 }
1036 }
1037
1038 r->objects->all_packs = p;
1039 }
1040
1041 return r->objects->all_packs;
1042 }
1043
1044 struct list_head *get_packed_git_mru(struct repository *r)
1045 {
1046 prepare_packed_git(r);
1047 return &r->objects->packed_git_mru;
1048 }
1049
1050 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1051 unsigned long len, enum object_type *type, unsigned long *sizep)
1052 {
1053 unsigned shift;
1054 unsigned long size, c;
1055 unsigned long used = 0;
1056
1057 c = buf[used++];
1058 *type = (c >> 4) & 7;
1059 size = c & 15;
1060 shift = 4;
1061 while (c & 0x80) {
1062 if (len <= used || bitsizeof(long) <= shift) {
1063 error("bad object header");
1064 size = used = 0;
1065 break;
1066 }
1067 c = buf[used++];
1068 size += (c & 0x7f) << shift;
1069 shift += 7;
1070 }
1071 *sizep = size;
1072 return used;
1073 }
1074
1075 unsigned long get_size_from_delta(struct packed_git *p,
1076 struct pack_window **w_curs,
1077 off_t curpos)
1078 {
1079 const unsigned char *data;
1080 unsigned char delta_head[20], *in;
1081 git_zstream stream;
1082 int st;
1083
1084 memset(&stream, 0, sizeof(stream));
1085 stream.next_out = delta_head;
1086 stream.avail_out = sizeof(delta_head);
1087
1088 git_inflate_init(&stream);
1089 do {
1090 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1091 stream.next_in = in;
1092 st = git_inflate(&stream, Z_FINISH);
1093 curpos += stream.next_in - in;
1094 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1095 stream.total_out < sizeof(delta_head));
1096 git_inflate_end(&stream);
1097 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1098 error("delta data unpack-initial failed");
1099 return 0;
1100 }
1101
1102 /* Examine the initial part of the delta to figure out
1103 * the result size.
1104 */
1105 data = delta_head;
1106
1107 /* ignore base size */
1108 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1109
1110 /* Read the result size */
1111 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1112 }
1113
1114 int unpack_object_header(struct packed_git *p,
1115 struct pack_window **w_curs,
1116 off_t *curpos,
1117 unsigned long *sizep)
1118 {
1119 unsigned char *base;
1120 unsigned long left;
1121 unsigned long used;
1122 enum object_type type;
1123
1124 /* use_pack() assures us we have [base, base + 20) available
1125 * as a range that we can look at. (Its actually the hash
1126 * size that is assured.) With our object header encoding
1127 * the maximum deflated object size is 2^137, which is just
1128 * insane, so we know won't exceed what we have been given.
1129 */
1130 base = use_pack(p, w_curs, *curpos, &left);
1131 used = unpack_object_header_buffer(base, left, &type, sizep);
1132 if (!used) {
1133 type = OBJ_BAD;
1134 } else
1135 *curpos += used;
1136
1137 return type;
1138 }
1139
1140 void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
1141 {
1142 unsigned i;
1143 const unsigned hashsz = the_hash_algo->rawsz;
1144 for (i = 0; i < p->num_bad_objects; i++)
1145 if (hasheq(sha1, p->bad_object_sha1 + hashsz * i))
1146 return;
1147 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1148 st_mult(GIT_MAX_RAWSZ,
1149 st_add(p->num_bad_objects, 1)));
1150 hashcpy(p->bad_object_sha1 + hashsz * p->num_bad_objects, sha1);
1151 p->num_bad_objects++;
1152 }
1153
1154 const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1155 {
1156 struct packed_git *p;
1157 unsigned i;
1158
1159 for (p = the_repository->objects->packed_git; p; p = p->next)
1160 for (i = 0; i < p->num_bad_objects; i++)
1161 if (hasheq(sha1,
1162 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1163 return p;
1164 return NULL;
1165 }
1166
1167 static off_t get_delta_base(struct packed_git *p,
1168 struct pack_window **w_curs,
1169 off_t *curpos,
1170 enum object_type type,
1171 off_t delta_obj_offset)
1172 {
1173 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1174 off_t base_offset;
1175
1176 /* use_pack() assured us we have [base_info, base_info + 20)
1177 * as a range that we can look at without walking off the
1178 * end of the mapped window. Its actually the hash size
1179 * that is assured. An OFS_DELTA longer than the hash size
1180 * is stupid, as then a REF_DELTA would be smaller to store.
1181 */
1182 if (type == OBJ_OFS_DELTA) {
1183 unsigned used = 0;
1184 unsigned char c = base_info[used++];
1185 base_offset = c & 127;
1186 while (c & 128) {
1187 base_offset += 1;
1188 if (!base_offset || MSB(base_offset, 7))
1189 return 0; /* overflow */
1190 c = base_info[used++];
1191 base_offset = (base_offset << 7) + (c & 127);
1192 }
1193 base_offset = delta_obj_offset - base_offset;
1194 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1195 return 0; /* out of bound */
1196 *curpos += used;
1197 } else if (type == OBJ_REF_DELTA) {
1198 /* The base entry _must_ be in the same pack */
1199 base_offset = find_pack_entry_one(base_info, p);
1200 *curpos += the_hash_algo->rawsz;
1201 } else
1202 die("I am totally screwed");
1203 return base_offset;
1204 }
1205
1206 /*
1207 * Like get_delta_base above, but we return the sha1 instead of the pack
1208 * offset. This means it is cheaper for REF deltas (we do not have to do
1209 * the final object lookup), but more expensive for OFS deltas (we
1210 * have to load the revidx to convert the offset back into a sha1).
1211 */
1212 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1213 struct pack_window **w_curs,
1214 off_t curpos,
1215 enum object_type type,
1216 off_t delta_obj_offset)
1217 {
1218 if (type == OBJ_REF_DELTA) {
1219 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1220 return base;
1221 } else if (type == OBJ_OFS_DELTA) {
1222 struct revindex_entry *revidx;
1223 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1224 type, delta_obj_offset);
1225
1226 if (!base_offset)
1227 return NULL;
1228
1229 revidx = find_pack_revindex(p, base_offset);
1230 if (!revidx)
1231 return NULL;
1232
1233 return nth_packed_object_sha1(p, revidx->nr);
1234 } else
1235 return NULL;
1236 }
1237
1238 static int retry_bad_packed_offset(struct repository *r,
1239 struct packed_git *p,
1240 off_t obj_offset)
1241 {
1242 int type;
1243 struct revindex_entry *revidx;
1244 struct object_id oid;
1245 revidx = find_pack_revindex(p, obj_offset);
1246 if (!revidx)
1247 return OBJ_BAD;
1248 nth_packed_object_oid(&oid, p, revidx->nr);
1249 mark_bad_packed_object(p, oid.hash);
1250 type = oid_object_info(r, &oid, NULL);
1251 if (type <= OBJ_NONE)
1252 return OBJ_BAD;
1253 return type;
1254 }
1255
1256 #define POI_STACK_PREALLOC 64
1257
1258 static enum object_type packed_to_object_type(struct repository *r,
1259 struct packed_git *p,
1260 off_t obj_offset,
1261 enum object_type type,
1262 struct pack_window **w_curs,
1263 off_t curpos)
1264 {
1265 off_t small_poi_stack[POI_STACK_PREALLOC];
1266 off_t *poi_stack = small_poi_stack;
1267 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1268
1269 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1270 off_t base_offset;
1271 unsigned long size;
1272 /* Push the object we're going to leave behind */
1273 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1274 poi_stack_alloc = alloc_nr(poi_stack_nr);
1275 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1276 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1277 } else {
1278 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1279 }
1280 poi_stack[poi_stack_nr++] = obj_offset;
1281 /* If parsing the base offset fails, just unwind */
1282 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1283 if (!base_offset)
1284 goto unwind;
1285 curpos = obj_offset = base_offset;
1286 type = unpack_object_header(p, w_curs, &curpos, &size);
1287 if (type <= OBJ_NONE) {
1288 /* If getting the base itself fails, we first
1289 * retry the base, otherwise unwind */
1290 type = retry_bad_packed_offset(r, p, base_offset);
1291 if (type > OBJ_NONE)
1292 goto out;
1293 goto unwind;
1294 }
1295 }
1296
1297 switch (type) {
1298 case OBJ_BAD:
1299 case OBJ_COMMIT:
1300 case OBJ_TREE:
1301 case OBJ_BLOB:
1302 case OBJ_TAG:
1303 break;
1304 default:
1305 error("unknown object type %i at offset %"PRIuMAX" in %s",
1306 type, (uintmax_t)obj_offset, p->pack_name);
1307 type = OBJ_BAD;
1308 }
1309
1310 out:
1311 if (poi_stack != small_poi_stack)
1312 free(poi_stack);
1313 return type;
1314
1315 unwind:
1316 while (poi_stack_nr) {
1317 obj_offset = poi_stack[--poi_stack_nr];
1318 type = retry_bad_packed_offset(r, p, obj_offset);
1319 if (type > OBJ_NONE)
1320 goto out;
1321 }
1322 type = OBJ_BAD;
1323 goto out;
1324 }
1325
1326 static struct hashmap delta_base_cache;
1327 static size_t delta_base_cached;
1328
1329 static LIST_HEAD(delta_base_cache_lru);
1330
1331 struct delta_base_cache_key {
1332 struct packed_git *p;
1333 off_t base_offset;
1334 };
1335
1336 struct delta_base_cache_entry {
1337 struct hashmap hash;
1338 struct delta_base_cache_key key;
1339 struct list_head lru;
1340 void *data;
1341 unsigned long size;
1342 enum object_type type;
1343 };
1344
1345 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
1346 {
1347 unsigned int hash;
1348
1349 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
1350 hash += (hash >> 8) + (hash >> 16);
1351 return hash;
1352 }
1353
1354 static struct delta_base_cache_entry *
1355 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1356 {
1357 struct hashmap_entry entry;
1358 struct delta_base_cache_key key;
1359
1360 if (!delta_base_cache.cmpfn)
1361 return NULL;
1362
1363 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
1364 key.p = p;
1365 key.base_offset = base_offset;
1366 return hashmap_get(&delta_base_cache, &entry, &key);
1367 }
1368
1369 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
1370 const struct delta_base_cache_key *b)
1371 {
1372 return a->p == b->p && a->base_offset == b->base_offset;
1373 }
1374
1375 static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
1376 const void *va, const void *vb,
1377 const void *vkey)
1378 {
1379 const struct delta_base_cache_entry *a = va, *b = vb;
1380 const struct delta_base_cache_key *key = vkey;
1381 if (key)
1382 return !delta_base_cache_key_eq(&a->key, key);
1383 else
1384 return !delta_base_cache_key_eq(&a->key, &b->key);
1385 }
1386
1387 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1388 {
1389 return !!get_delta_base_cache_entry(p, base_offset);
1390 }
1391
1392 /*
1393 * Remove the entry from the cache, but do _not_ free the associated
1394 * entry data. The caller takes ownership of the "data" buffer, and
1395 * should copy out any fields it wants before detaching.
1396 */
1397 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1398 {
1399 hashmap_remove(&delta_base_cache, ent, &ent->key);
1400 list_del(&ent->lru);
1401 delta_base_cached -= ent->size;
1402 free(ent);
1403 }
1404
1405 static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
1406 off_t base_offset, unsigned long *base_size,
1407 enum object_type *type)
1408 {
1409 struct delta_base_cache_entry *ent;
1410
1411 ent = get_delta_base_cache_entry(p, base_offset);
1412 if (!ent)
1413 return unpack_entry(r, p, base_offset, type, base_size);
1414
1415 if (type)
1416 *type = ent->type;
1417 if (base_size)
1418 *base_size = ent->size;
1419 return xmemdupz(ent->data, ent->size);
1420 }
1421
1422 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1423 {
1424 free(ent->data);
1425 detach_delta_base_cache_entry(ent);
1426 }
1427
1428 void clear_delta_base_cache(void)
1429 {
1430 struct list_head *lru, *tmp;
1431 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1432 struct delta_base_cache_entry *entry =
1433 list_entry(lru, struct delta_base_cache_entry, lru);
1434 release_delta_base_cache(entry);
1435 }
1436 }
1437
1438 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1439 void *base, unsigned long base_size, enum object_type type)
1440 {
1441 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
1442 struct list_head *lru, *tmp;
1443
1444 delta_base_cached += base_size;
1445
1446 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1447 struct delta_base_cache_entry *f =
1448 list_entry(lru, struct delta_base_cache_entry, lru);
1449 if (delta_base_cached <= delta_base_cache_limit)
1450 break;
1451 release_delta_base_cache(f);
1452 }
1453
1454 ent->key.p = p;
1455 ent->key.base_offset = base_offset;
1456 ent->type = type;
1457 ent->data = base;
1458 ent->size = base_size;
1459 list_add_tail(&ent->lru, &delta_base_cache_lru);
1460
1461 if (!delta_base_cache.cmpfn)
1462 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
1463 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
1464 hashmap_add(&delta_base_cache, ent);
1465 }
1466
1467 int packed_object_info(struct repository *r, struct packed_git *p,
1468 off_t obj_offset, struct object_info *oi)
1469 {
1470 struct pack_window *w_curs = NULL;
1471 unsigned long size;
1472 off_t curpos = obj_offset;
1473 enum object_type type;
1474
1475 /*
1476 * We always get the representation type, but only convert it to
1477 * a "real" type later if the caller is interested.
1478 */
1479 if (oi->contentp) {
1480 *oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
1481 &type);
1482 if (!*oi->contentp)
1483 type = OBJ_BAD;
1484 } else {
1485 type = unpack_object_header(p, &w_curs, &curpos, &size);
1486 }
1487
1488 if (!oi->contentp && oi->sizep) {
1489 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1490 off_t tmp_pos = curpos;
1491 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1492 type, obj_offset);
1493 if (!base_offset) {
1494 type = OBJ_BAD;
1495 goto out;
1496 }
1497 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1498 if (*oi->sizep == 0) {
1499 type = OBJ_BAD;
1500 goto out;
1501 }
1502 } else {
1503 *oi->sizep = size;
1504 }
1505 }
1506
1507 if (oi->disk_sizep) {
1508 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1509 *oi->disk_sizep = revidx[1].offset - obj_offset;
1510 }
1511
1512 if (oi->typep || oi->type_name) {
1513 enum object_type ptot;
1514 ptot = packed_to_object_type(r, p, obj_offset,
1515 type, &w_curs, curpos);
1516 if (oi->typep)
1517 *oi->typep = ptot;
1518 if (oi->type_name) {
1519 const char *tn = type_name(ptot);
1520 if (tn)
1521 strbuf_addstr(oi->type_name, tn);
1522 }
1523 if (ptot < 0) {
1524 type = OBJ_BAD;
1525 goto out;
1526 }
1527 }
1528
1529 if (oi->delta_base_sha1) {
1530 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1531 const unsigned char *base;
1532
1533 base = get_delta_base_sha1(p, &w_curs, curpos,
1534 type, obj_offset);
1535 if (!base) {
1536 type = OBJ_BAD;
1537 goto out;
1538 }
1539
1540 hashcpy(oi->delta_base_sha1, base);
1541 } else
1542 hashclr(oi->delta_base_sha1);
1543 }
1544
1545 oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
1546 OI_PACKED;
1547
1548 out:
1549 unuse_pack(&w_curs);
1550 return type;
1551 }
1552
1553 static void *unpack_compressed_entry(struct packed_git *p,
1554 struct pack_window **w_curs,
1555 off_t curpos,
1556 unsigned long size)
1557 {
1558 int st;
1559 git_zstream stream;
1560 unsigned char *buffer, *in;
1561
1562 buffer = xmallocz_gently(size);
1563 if (!buffer)
1564 return NULL;
1565 memset(&stream, 0, sizeof(stream));
1566 stream.next_out = buffer;
1567 stream.avail_out = size + 1;
1568
1569 git_inflate_init(&stream);
1570 do {
1571 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1572 stream.next_in = in;
1573 st = git_inflate(&stream, Z_FINISH);
1574 if (!stream.avail_out)
1575 break; /* the payload is larger than it should be */
1576 curpos += stream.next_in - in;
1577 } while (st == Z_OK || st == Z_BUF_ERROR);
1578 git_inflate_end(&stream);
1579 if ((st != Z_STREAM_END) || stream.total_out != size) {
1580 free(buffer);
1581 return NULL;
1582 }
1583
1584 /* versions of zlib can clobber unconsumed portion of outbuf */
1585 buffer[size] = '\0';
1586
1587 return buffer;
1588 }
1589
1590 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1591 {
1592 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
1593 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
1594 p->pack_name, (uintmax_t)obj_offset);
1595 }
1596
1597 int do_check_packed_object_crc;
1598
1599 #define UNPACK_ENTRY_STACK_PREALLOC 64
1600 struct unpack_entry_stack_ent {
1601 off_t obj_offset;
1602 off_t curpos;
1603 unsigned long size;
1604 };
1605
1606 static void *read_object(struct repository *r,
1607 const struct object_id *oid,
1608 enum object_type *type,
1609 unsigned long *size)
1610 {
1611 struct object_info oi = OBJECT_INFO_INIT;
1612 void *content;
1613 oi.typep = type;
1614 oi.sizep = size;
1615 oi.contentp = &content;
1616
1617 if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1618 return NULL;
1619 return content;
1620 }
1621
1622 void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
1623 enum object_type *final_type, unsigned long *final_size)
1624 {
1625 struct pack_window *w_curs = NULL;
1626 off_t curpos = obj_offset;
1627 void *data = NULL;
1628 unsigned long size;
1629 enum object_type type;
1630 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
1631 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
1632 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
1633 int base_from_cache = 0;
1634
1635 write_pack_access_log(p, obj_offset);
1636
1637 /* PHASE 1: drill down to the innermost base object */
1638 for (;;) {
1639 off_t base_offset;
1640 int i;
1641 struct delta_base_cache_entry *ent;
1642
1643 ent = get_delta_base_cache_entry(p, curpos);
1644 if (ent) {
1645 type = ent->type;
1646 data = ent->data;
1647 size = ent->size;
1648 detach_delta_base_cache_entry(ent);
1649 base_from_cache = 1;
1650 break;
1651 }
1652
1653 if (do_check_packed_object_crc && p->index_version > 1) {
1654 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1655 off_t len = revidx[1].offset - obj_offset;
1656 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1657 struct object_id oid;
1658 nth_packed_object_oid(&oid, p, revidx->nr);
1659 error("bad packed object CRC for %s",
1660 oid_to_hex(&oid));
1661 mark_bad_packed_object(p, oid.hash);
1662 data = NULL;
1663 goto out;
1664 }
1665 }
1666
1667 type = unpack_object_header(p, &w_curs, &curpos, &size);
1668 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
1669 break;
1670
1671 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1672 if (!base_offset) {
1673 error("failed to validate delta base reference "
1674 "at offset %"PRIuMAX" from %s",
1675 (uintmax_t)curpos, p->pack_name);
1676 /* bail to phase 2, in hopes of recovery */
1677 data = NULL;
1678 break;
1679 }
1680
1681 /* push object, proceed to base */
1682 if (delta_stack_nr >= delta_stack_alloc
1683 && delta_stack == small_delta_stack) {
1684 delta_stack_alloc = alloc_nr(delta_stack_nr);
1685 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
1686 memcpy(delta_stack, small_delta_stack,
1687 sizeof(*delta_stack)*delta_stack_nr);
1688 } else {
1689 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
1690 }
1691 i = delta_stack_nr++;
1692 delta_stack[i].obj_offset = obj_offset;
1693 delta_stack[i].curpos = curpos;
1694 delta_stack[i].size = size;
1695
1696 curpos = obj_offset = base_offset;
1697 }
1698
1699 /* PHASE 2: handle the base */
1700 switch (type) {
1701 case OBJ_OFS_DELTA:
1702 case OBJ_REF_DELTA:
1703 if (data)
1704 BUG("unpack_entry: left loop at a valid delta");
1705 break;
1706 case OBJ_COMMIT:
1707 case OBJ_TREE:
1708 case OBJ_BLOB:
1709 case OBJ_TAG:
1710 if (!base_from_cache)
1711 data = unpack_compressed_entry(p, &w_curs, curpos, size);
1712 break;
1713 default:
1714 data = NULL;
1715 error("unknown object type %i at offset %"PRIuMAX" in %s",
1716 type, (uintmax_t)obj_offset, p->pack_name);
1717 }
1718
1719 /* PHASE 3: apply deltas in order */
1720
1721 /* invariants:
1722 * 'data' holds the base data, or NULL if there was corruption
1723 */
1724 while (delta_stack_nr) {
1725 void *delta_data;
1726 void *base = data;
1727 void *external_base = NULL;
1728 unsigned long delta_size, base_size = size;
1729 int i;
1730
1731 data = NULL;
1732
1733 if (base)
1734 add_delta_base_cache(p, obj_offset, base, base_size, type);
1735
1736 if (!base) {
1737 /*
1738 * We're probably in deep shit, but let's try to fetch
1739 * the required base anyway from another pack or loose.
1740 * This is costly but should happen only in the presence
1741 * of a corrupted pack, and is better than failing outright.
1742 */
1743 struct revindex_entry *revidx;
1744 struct object_id base_oid;
1745 revidx = find_pack_revindex(p, obj_offset);
1746 if (revidx) {
1747 nth_packed_object_oid(&base_oid, p, revidx->nr);
1748 error("failed to read delta base object %s"
1749 " at offset %"PRIuMAX" from %s",
1750 oid_to_hex(&base_oid), (uintmax_t)obj_offset,
1751 p->pack_name);
1752 mark_bad_packed_object(p, base_oid.hash);
1753 base = read_object(r, &base_oid, &type, &base_size);
1754 external_base = base;
1755 }
1756 }
1757
1758 i = --delta_stack_nr;
1759 obj_offset = delta_stack[i].obj_offset;
1760 curpos = delta_stack[i].curpos;
1761 delta_size = delta_stack[i].size;
1762
1763 if (!base)
1764 continue;
1765
1766 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
1767
1768 if (!delta_data) {
1769 error("failed to unpack compressed delta "
1770 "at offset %"PRIuMAX" from %s",
1771 (uintmax_t)curpos, p->pack_name);
1772 data = NULL;
1773 free(external_base);
1774 continue;
1775 }
1776
1777 data = patch_delta(base, base_size,
1778 delta_data, delta_size,
1779 &size);
1780
1781 /*
1782 * We could not apply the delta; warn the user, but keep going.
1783 * Our failure will be noticed either in the next iteration of
1784 * the loop, or if this is the final delta, in the caller when
1785 * we return NULL. Those code paths will take care of making
1786 * a more explicit warning and retrying with another copy of
1787 * the object.
1788 */
1789 if (!data)
1790 error("failed to apply delta");
1791
1792 free(delta_data);
1793 free(external_base);
1794 }
1795
1796 if (final_type)
1797 *final_type = type;
1798 if (final_size)
1799 *final_size = size;
1800
1801 out:
1802 unuse_pack(&w_curs);
1803
1804 if (delta_stack != small_delta_stack)
1805 free(delta_stack);
1806
1807 return data;
1808 }
1809
1810 int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
1811 {
1812 const unsigned char *index_fanout = p->index_data;
1813 const unsigned char *index_lookup;
1814 const unsigned int hashsz = the_hash_algo->rawsz;
1815 int index_lookup_width;
1816
1817 if (!index_fanout)
1818 BUG("bsearch_pack called without a valid pack-index");
1819
1820 index_lookup = index_fanout + 4 * 256;
1821 if (p->index_version == 1) {
1822 index_lookup_width = hashsz + 4;
1823 index_lookup += 4;
1824 } else {
1825 index_lookup_width = hashsz;
1826 index_fanout += 8;
1827 index_lookup += 8;
1828 }
1829
1830 return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
1831 index_lookup, index_lookup_width, result);
1832 }
1833
1834 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1835 uint32_t n)
1836 {
1837 const unsigned char *index = p->index_data;
1838 const unsigned int hashsz = the_hash_algo->rawsz;
1839 if (!index) {
1840 if (open_pack_index(p))
1841 return NULL;
1842 index = p->index_data;
1843 }
1844 if (n >= p->num_objects)
1845 return NULL;
1846 index += 4 * 256;
1847 if (p->index_version == 1) {
1848 return index + (hashsz + 4) * n + 4;
1849 } else {
1850 index += 8;
1851 return index + hashsz * n;
1852 }
1853 }
1854
1855 const struct object_id *nth_packed_object_oid(struct object_id *oid,
1856 struct packed_git *p,
1857 uint32_t n)
1858 {
1859 const unsigned char *hash = nth_packed_object_sha1(p, n);
1860 if (!hash)
1861 return NULL;
1862 hashcpy(oid->hash, hash);
1863 return oid;
1864 }
1865
1866 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
1867 {
1868 const unsigned char *ptr = vptr;
1869 const unsigned char *start = p->index_data;
1870 const unsigned char *end = start + p->index_size;
1871 if (ptr < start)
1872 die(_("offset before start of pack index for %s (corrupt index?)"),
1873 p->pack_name);
1874 /* No need to check for underflow; .idx files must be at least 8 bytes */
1875 if (ptr >= end - 8)
1876 die(_("offset beyond end of pack index for %s (truncated index?)"),
1877 p->pack_name);
1878 }
1879
1880 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1881 {
1882 const unsigned char *index = p->index_data;
1883 const unsigned int hashsz = the_hash_algo->rawsz;
1884 index += 4 * 256;
1885 if (p->index_version == 1) {
1886 return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
1887 } else {
1888 uint32_t off;
1889 index += 8 + p->num_objects * (hashsz + 4);
1890 off = ntohl(*((uint32_t *)(index + 4 * n)));
1891 if (!(off & 0x80000000))
1892 return off;
1893 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1894 check_pack_index_ptr(p, index);
1895 return get_be64(index);
1896 }
1897 }
1898
1899 off_t find_pack_entry_one(const unsigned char *sha1,
1900 struct packed_git *p)
1901 {
1902 const unsigned char *index = p->index_data;
1903 struct object_id oid;
1904 uint32_t result;
1905
1906 if (!index) {
1907 if (open_pack_index(p))
1908 return 0;
1909 }
1910
1911 hashcpy(oid.hash, sha1);
1912 if (bsearch_pack(&oid, p, &result))
1913 return nth_packed_object_offset(p, result);
1914 return 0;
1915 }
1916
1917 int is_pack_valid(struct packed_git *p)
1918 {
1919 /* An already open pack is known to be valid. */
1920 if (p->pack_fd != -1)
1921 return 1;
1922
1923 /* If the pack has one window completely covering the
1924 * file size, the pack is known to be valid even if
1925 * the descriptor is not currently open.
1926 */
1927 if (p->windows) {
1928 struct pack_window *w = p->windows;
1929
1930 if (!w->offset && w->len == p->pack_size)
1931 return 1;
1932 }
1933
1934 /* Force the pack to open to prove its valid. */
1935 return !open_packed_git(p);
1936 }
1937
1938 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1939 struct packed_git *packs)
1940 {
1941 struct packed_git *p;
1942
1943 for (p = packs; p; p = p->next) {
1944 if (find_pack_entry_one(sha1, p))
1945 return p;
1946 }
1947 return NULL;
1948
1949 }
1950
1951 static int fill_pack_entry(const struct object_id *oid,
1952 struct pack_entry *e,
1953 struct packed_git *p)
1954 {
1955 off_t offset;
1956
1957 if (p->num_bad_objects) {
1958 unsigned i;
1959 for (i = 0; i < p->num_bad_objects; i++)
1960 if (hasheq(oid->hash,
1961 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1962 return 0;
1963 }
1964
1965 offset = find_pack_entry_one(oid->hash, p);
1966 if (!offset)
1967 return 0;
1968
1969 /*
1970 * We are about to tell the caller where they can locate the
1971 * requested object. We better make sure the packfile is
1972 * still here and can be accessed before supplying that
1973 * answer, as it may have been deleted since the index was
1974 * loaded!
1975 */
1976 if (!is_pack_valid(p))
1977 return 0;
1978 e->offset = offset;
1979 e->p = p;
1980 return 1;
1981 }
1982
1983 int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
1984 {
1985 struct list_head *pos;
1986 struct multi_pack_index *m;
1987
1988 prepare_packed_git(r);
1989 if (!r->objects->packed_git && !r->objects->multi_pack_index)
1990 return 0;
1991
1992 for (m = r->objects->multi_pack_index; m; m = m->next) {
1993 if (fill_midx_entry(oid, e, m))
1994 return 1;
1995 }
1996
1997 list_for_each(pos, &r->objects->packed_git_mru) {
1998 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1999 if (fill_pack_entry(oid, e, p)) {
2000 list_move(&p->mru, &r->objects->packed_git_mru);
2001 return 1;
2002 }
2003 }
2004 return 0;
2005 }
2006
2007 int has_object_pack(const struct object_id *oid)
2008 {
2009 struct pack_entry e;
2010 return find_pack_entry(the_repository, oid, &e);
2011 }
2012
2013 int has_pack_index(const unsigned char *sha1)
2014 {
2015 struct stat st;
2016 if (stat(sha1_pack_index_name(sha1), &st))
2017 return 0;
2018 return 1;
2019 }
2020
2021 int for_each_object_in_pack(struct packed_git *p,
2022 each_packed_object_fn cb, void *data,
2023 enum for_each_object_flags flags)
2024 {
2025 uint32_t i;
2026 int r = 0;
2027
2028 if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2029 load_pack_revindex(p);
2030
2031 for (i = 0; i < p->num_objects; i++) {
2032 uint32_t pos;
2033 struct object_id oid;
2034
2035 if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2036 pos = p->revindex[i].nr;
2037 else
2038 pos = i;
2039
2040 if (!nth_packed_object_oid(&oid, p, pos))
2041 return error("unable to get sha1 of object %u in %s",
2042 pos, p->pack_name);
2043
2044 r = cb(&oid, p, pos, data);
2045 if (r)
2046 break;
2047 }
2048 return r;
2049 }
2050
2051 int for_each_packed_object(each_packed_object_fn cb, void *data,
2052 enum for_each_object_flags flags)
2053 {
2054 struct packed_git *p;
2055 int r = 0;
2056 int pack_errors = 0;
2057
2058 prepare_packed_git(the_repository);
2059 for (p = get_all_packs(the_repository); p; p = p->next) {
2060 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
2061 continue;
2062 if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
2063 !p->pack_promisor)
2064 continue;
2065 if (open_pack_index(p)) {
2066 pack_errors = 1;
2067 continue;
2068 }
2069 r = for_each_object_in_pack(p, cb, data, flags);
2070 if (r)
2071 break;
2072 }
2073 return r ? r : pack_errors;
2074 }
2075
2076 static int add_promisor_object(const struct object_id *oid,
2077 struct packed_git *pack,
2078 uint32_t pos,
2079 void *set_)
2080 {
2081 struct oidset *set = set_;
2082 struct object *obj = parse_object(the_repository, oid);
2083 if (!obj)
2084 return 1;
2085
2086 oidset_insert(set, oid);
2087
2088 /*
2089 * If this is a tree, commit, or tag, the objects it refers
2090 * to are also promisor objects. (Blobs refer to no objects->)
2091 */
2092 if (obj->type == OBJ_TREE) {
2093 struct tree *tree = (struct tree *)obj;
2094 struct tree_desc desc;
2095 struct name_entry entry;
2096 if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
2097 /*
2098 * Error messages are given when packs are
2099 * verified, so do not print any here.
2100 */
2101 return 0;
2102 while (tree_entry_gently(&desc, &entry))
2103 oidset_insert(set, entry.oid);
2104 } else if (obj->type == OBJ_COMMIT) {
2105 struct commit *commit = (struct commit *) obj;
2106 struct commit_list *parents = commit->parents;
2107
2108 oidset_insert(set, get_commit_tree_oid(commit));
2109 for (; parents; parents = parents->next)
2110 oidset_insert(set, &parents->item->object.oid);
2111 } else if (obj->type == OBJ_TAG) {
2112 struct tag *tag = (struct tag *) obj;
2113 oidset_insert(set, &tag->tagged->oid);
2114 }
2115 return 0;
2116 }
2117
2118 int is_promisor_object(const struct object_id *oid)
2119 {
2120 static struct oidset promisor_objects;
2121 static int promisor_objects_prepared;
2122
2123 if (!promisor_objects_prepared) {
2124 if (repository_format_partial_clone) {
2125 for_each_packed_object(add_promisor_object,
2126 &promisor_objects,
2127 FOR_EACH_OBJECT_PROMISOR_ONLY);
2128 }
2129 promisor_objects_prepared = 1;
2130 }
2131 return oidset_contains(&promisor_objects, oid);
2132 }
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