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Sync with 2.19.3
[git/debian.git] / packfile.c
blobd1e6683ffe877d9bf1b0996f25f0720fdffe983a
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 alternate_object_database *alt;
975
976 if (r->objects->packed_git_initialized)
977 return;
978 prepare_multi_pack_index_one(r, r->objects->objectdir, 1);
979 prepare_packed_git_one(r, r->objects->objectdir, 1);
980 prepare_alt_odb(r);
981 for (alt = r->objects->alt_odb_list; alt; alt = alt->next) {
982 prepare_multi_pack_index_one(r, alt->path, 0);
983 prepare_packed_git_one(r, alt->path, 0);
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 r->objects->approximate_object_count_valid = 0;
996 r->objects->packed_git_initialized = 0;
997 prepare_packed_git(r);
998 }
999
1000 struct packed_git *get_packed_git(struct repository *r)
1001 {
1002 prepare_packed_git(r);
1003 return r->objects->packed_git;
1004 }
1005
1006 struct multi_pack_index *get_multi_pack_index(struct repository *r)
1007 {
1008 prepare_packed_git(r);
1009 return r->objects->multi_pack_index;
1010 }
1011
1012 struct packed_git *get_all_packs(struct repository *r)
1013 {
1014 prepare_packed_git(r);
1015
1016 if (!r->objects->all_packs) {
1017 struct packed_git *p = r->objects->packed_git;
1018 struct multi_pack_index *m;
1019
1020 for (m = r->objects->multi_pack_index; m; m = m->next) {
1021 uint32_t i;
1022 for (i = 0; i < m->num_packs; i++) {
1023 if (!prepare_midx_pack(m, i)) {
1024 m->packs[i]->next = p;
1025 p = m->packs[i];
1026 }
1027 }
1028 }
1029
1030 r->objects->all_packs = p;
1031 }
1032
1033 return r->objects->all_packs;
1034 }
1035
1036 struct list_head *get_packed_git_mru(struct repository *r)
1037 {
1038 prepare_packed_git(r);
1039 return &r->objects->packed_git_mru;
1040 }
1041
1042 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1043 unsigned long len, enum object_type *type, unsigned long *sizep)
1044 {
1045 unsigned shift;
1046 unsigned long size, c;
1047 unsigned long used = 0;
1048
1049 c = buf[used++];
1050 *type = (c >> 4) & 7;
1051 size = c & 15;
1052 shift = 4;
1053 while (c & 0x80) {
1054 if (len <= used || bitsizeof(long) <= shift) {
1055 error("bad object header");
1056 size = used = 0;
1057 break;
1058 }
1059 c = buf[used++];
1060 size += (c & 0x7f) << shift;
1061 shift += 7;
1062 }
1063 *sizep = size;
1064 return used;
1065 }
1066
1067 unsigned long get_size_from_delta(struct packed_git *p,
1068 struct pack_window **w_curs,
1069 off_t curpos)
1070 {
1071 const unsigned char *data;
1072 unsigned char delta_head[20], *in;
1073 git_zstream stream;
1074 int st;
1075
1076 memset(&stream, 0, sizeof(stream));
1077 stream.next_out = delta_head;
1078 stream.avail_out = sizeof(delta_head);
1079
1080 git_inflate_init(&stream);
1081 do {
1082 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1083 stream.next_in = in;
1084 st = git_inflate(&stream, Z_FINISH);
1085 curpos += stream.next_in - in;
1086 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1087 stream.total_out < sizeof(delta_head));
1088 git_inflate_end(&stream);
1089 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1090 error("delta data unpack-initial failed");
1091 return 0;
1092 }
1093
1094 /* Examine the initial part of the delta to figure out
1095 * the result size.
1096 */
1097 data = delta_head;
1098
1099 /* ignore base size */
1100 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1101
1102 /* Read the result size */
1103 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1104 }
1105
1106 int unpack_object_header(struct packed_git *p,
1107 struct pack_window **w_curs,
1108 off_t *curpos,
1109 unsigned long *sizep)
1110 {
1111 unsigned char *base;
1112 unsigned long left;
1113 unsigned long used;
1114 enum object_type type;
1115
1116 /* use_pack() assures us we have [base, base + 20) available
1117 * as a range that we can look at. (Its actually the hash
1118 * size that is assured.) With our object header encoding
1119 * the maximum deflated object size is 2^137, which is just
1120 * insane, so we know won't exceed what we have been given.
1121 */
1122 base = use_pack(p, w_curs, *curpos, &left);
1123 used = unpack_object_header_buffer(base, left, &type, sizep);
1124 if (!used) {
1125 type = OBJ_BAD;
1126 } else
1127 *curpos += used;
1128
1129 return type;
1130 }
1131
1132 void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
1133 {
1134 unsigned i;
1135 const unsigned hashsz = the_hash_algo->rawsz;
1136 for (i = 0; i < p->num_bad_objects; i++)
1137 if (hasheq(sha1, p->bad_object_sha1 + hashsz * i))
1138 return;
1139 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1140 st_mult(GIT_MAX_RAWSZ,
1141 st_add(p->num_bad_objects, 1)));
1142 hashcpy(p->bad_object_sha1 + hashsz * p->num_bad_objects, sha1);
1143 p->num_bad_objects++;
1144 }
1145
1146 const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1147 {
1148 struct packed_git *p;
1149 unsigned i;
1150
1151 for (p = the_repository->objects->packed_git; p; p = p->next)
1152 for (i = 0; i < p->num_bad_objects; i++)
1153 if (hasheq(sha1,
1154 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1155 return p;
1156 return NULL;
1157 }
1158
1159 static off_t get_delta_base(struct packed_git *p,
1160 struct pack_window **w_curs,
1161 off_t *curpos,
1162 enum object_type type,
1163 off_t delta_obj_offset)
1164 {
1165 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1166 off_t base_offset;
1167
1168 /* use_pack() assured us we have [base_info, base_info + 20)
1169 * as a range that we can look at without walking off the
1170 * end of the mapped window. Its actually the hash size
1171 * that is assured. An OFS_DELTA longer than the hash size
1172 * is stupid, as then a REF_DELTA would be smaller to store.
1173 */
1174 if (type == OBJ_OFS_DELTA) {
1175 unsigned used = 0;
1176 unsigned char c = base_info[used++];
1177 base_offset = c & 127;
1178 while (c & 128) {
1179 base_offset += 1;
1180 if (!base_offset || MSB(base_offset, 7))
1181 return 0; /* overflow */
1182 c = base_info[used++];
1183 base_offset = (base_offset << 7) + (c & 127);
1184 }
1185 base_offset = delta_obj_offset - base_offset;
1186 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1187 return 0; /* out of bound */
1188 *curpos += used;
1189 } else if (type == OBJ_REF_DELTA) {
1190 /* The base entry _must_ be in the same pack */
1191 base_offset = find_pack_entry_one(base_info, p);
1192 *curpos += the_hash_algo->rawsz;
1193 } else
1194 die("I am totally screwed");
1195 return base_offset;
1196 }
1197
1198 /*
1199 * Like get_delta_base above, but we return the sha1 instead of the pack
1200 * offset. This means it is cheaper for REF deltas (we do not have to do
1201 * the final object lookup), but more expensive for OFS deltas (we
1202 * have to load the revidx to convert the offset back into a sha1).
1203 */
1204 static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1205 struct pack_window **w_curs,
1206 off_t curpos,
1207 enum object_type type,
1208 off_t delta_obj_offset)
1209 {
1210 if (type == OBJ_REF_DELTA) {
1211 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1212 return base;
1213 } else if (type == OBJ_OFS_DELTA) {
1214 struct revindex_entry *revidx;
1215 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1216 type, delta_obj_offset);
1217
1218 if (!base_offset)
1219 return NULL;
1220
1221 revidx = find_pack_revindex(p, base_offset);
1222 if (!revidx)
1223 return NULL;
1224
1225 return nth_packed_object_sha1(p, revidx->nr);
1226 } else
1227 return NULL;
1228 }
1229
1230 static int retry_bad_packed_offset(struct repository *r,
1231 struct packed_git *p,
1232 off_t obj_offset)
1233 {
1234 int type;
1235 struct revindex_entry *revidx;
1236 struct object_id oid;
1237 revidx = find_pack_revindex(p, obj_offset);
1238 if (!revidx)
1239 return OBJ_BAD;
1240 nth_packed_object_oid(&oid, p, revidx->nr);
1241 mark_bad_packed_object(p, oid.hash);
1242 type = oid_object_info(r, &oid, NULL);
1243 if (type <= OBJ_NONE)
1244 return OBJ_BAD;
1245 return type;
1246 }
1247
1248 #define POI_STACK_PREALLOC 64
1249
1250 static enum object_type packed_to_object_type(struct repository *r,
1251 struct packed_git *p,
1252 off_t obj_offset,
1253 enum object_type type,
1254 struct pack_window **w_curs,
1255 off_t curpos)
1256 {
1257 off_t small_poi_stack[POI_STACK_PREALLOC];
1258 off_t *poi_stack = small_poi_stack;
1259 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1260
1261 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1262 off_t base_offset;
1263 unsigned long size;
1264 /* Push the object we're going to leave behind */
1265 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1266 poi_stack_alloc = alloc_nr(poi_stack_nr);
1267 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1268 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1269 } else {
1270 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1271 }
1272 poi_stack[poi_stack_nr++] = obj_offset;
1273 /* If parsing the base offset fails, just unwind */
1274 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1275 if (!base_offset)
1276 goto unwind;
1277 curpos = obj_offset = base_offset;
1278 type = unpack_object_header(p, w_curs, &curpos, &size);
1279 if (type <= OBJ_NONE) {
1280 /* If getting the base itself fails, we first
1281 * retry the base, otherwise unwind */
1282 type = retry_bad_packed_offset(r, p, base_offset);
1283 if (type > OBJ_NONE)
1284 goto out;
1285 goto unwind;
1286 }
1287 }
1288
1289 switch (type) {
1290 case OBJ_BAD:
1291 case OBJ_COMMIT:
1292 case OBJ_TREE:
1293 case OBJ_BLOB:
1294 case OBJ_TAG:
1295 break;
1296 default:
1297 error("unknown object type %i at offset %"PRIuMAX" in %s",
1298 type, (uintmax_t)obj_offset, p->pack_name);
1299 type = OBJ_BAD;
1300 }
1301
1302 out:
1303 if (poi_stack != small_poi_stack)
1304 free(poi_stack);
1305 return type;
1306
1307 unwind:
1308 while (poi_stack_nr) {
1309 obj_offset = poi_stack[--poi_stack_nr];
1310 type = retry_bad_packed_offset(r, p, obj_offset);
1311 if (type > OBJ_NONE)
1312 goto out;
1313 }
1314 type = OBJ_BAD;
1315 goto out;
1316 }
1317
1318 static struct hashmap delta_base_cache;
1319 static size_t delta_base_cached;
1320
1321 static LIST_HEAD(delta_base_cache_lru);
1322
1323 struct delta_base_cache_key {
1324 struct packed_git *p;
1325 off_t base_offset;
1326 };
1327
1328 struct delta_base_cache_entry {
1329 struct hashmap hash;
1330 struct delta_base_cache_key key;
1331 struct list_head lru;
1332 void *data;
1333 unsigned long size;
1334 enum object_type type;
1335 };
1336
1337 static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
1338 {
1339 unsigned int hash;
1340
1341 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
1342 hash += (hash >> 8) + (hash >> 16);
1343 return hash;
1344 }
1345
1346 static struct delta_base_cache_entry *
1347 get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1348 {
1349 struct hashmap_entry entry;
1350 struct delta_base_cache_key key;
1351
1352 if (!delta_base_cache.cmpfn)
1353 return NULL;
1354
1355 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
1356 key.p = p;
1357 key.base_offset = base_offset;
1358 return hashmap_get(&delta_base_cache, &entry, &key);
1359 }
1360
1361 static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
1362 const struct delta_base_cache_key *b)
1363 {
1364 return a->p == b->p && a->base_offset == b->base_offset;
1365 }
1366
1367 static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
1368 const void *va, const void *vb,
1369 const void *vkey)
1370 {
1371 const struct delta_base_cache_entry *a = va, *b = vb;
1372 const struct delta_base_cache_key *key = vkey;
1373 if (key)
1374 return !delta_base_cache_key_eq(&a->key, key);
1375 else
1376 return !delta_base_cache_key_eq(&a->key, &b->key);
1377 }
1378
1379 static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1380 {
1381 return !!get_delta_base_cache_entry(p, base_offset);
1382 }
1383
1384 /*
1385 * Remove the entry from the cache, but do _not_ free the associated
1386 * entry data. The caller takes ownership of the "data" buffer, and
1387 * should copy out any fields it wants before detaching.
1388 */
1389 static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1390 {
1391 hashmap_remove(&delta_base_cache, ent, &ent->key);
1392 list_del(&ent->lru);
1393 delta_base_cached -= ent->size;
1394 free(ent);
1395 }
1396
1397 static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
1398 off_t base_offset, unsigned long *base_size,
1399 enum object_type *type)
1400 {
1401 struct delta_base_cache_entry *ent;
1402
1403 ent = get_delta_base_cache_entry(p, base_offset);
1404 if (!ent)
1405 return unpack_entry(r, p, base_offset, type, base_size);
1406
1407 if (type)
1408 *type = ent->type;
1409 if (base_size)
1410 *base_size = ent->size;
1411 return xmemdupz(ent->data, ent->size);
1412 }
1413
1414 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1415 {
1416 free(ent->data);
1417 detach_delta_base_cache_entry(ent);
1418 }
1419
1420 void clear_delta_base_cache(void)
1421 {
1422 struct list_head *lru, *tmp;
1423 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1424 struct delta_base_cache_entry *entry =
1425 list_entry(lru, struct delta_base_cache_entry, lru);
1426 release_delta_base_cache(entry);
1427 }
1428 }
1429
1430 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1431 void *base, unsigned long base_size, enum object_type type)
1432 {
1433 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
1434 struct list_head *lru, *tmp;
1435
1436 delta_base_cached += base_size;
1437
1438 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1439 struct delta_base_cache_entry *f =
1440 list_entry(lru, struct delta_base_cache_entry, lru);
1441 if (delta_base_cached <= delta_base_cache_limit)
1442 break;
1443 release_delta_base_cache(f);
1444 }
1445
1446 ent->key.p = p;
1447 ent->key.base_offset = base_offset;
1448 ent->type = type;
1449 ent->data = base;
1450 ent->size = base_size;
1451 list_add_tail(&ent->lru, &delta_base_cache_lru);
1452
1453 if (!delta_base_cache.cmpfn)
1454 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
1455 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
1456 hashmap_add(&delta_base_cache, ent);
1457 }
1458
1459 int packed_object_info(struct repository *r, struct packed_git *p,
1460 off_t obj_offset, struct object_info *oi)
1461 {
1462 struct pack_window *w_curs = NULL;
1463 unsigned long size;
1464 off_t curpos = obj_offset;
1465 enum object_type type;
1466
1467 /*
1468 * We always get the representation type, but only convert it to
1469 * a "real" type later if the caller is interested.
1470 */
1471 if (oi->contentp) {
1472 *oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
1473 &type);
1474 if (!*oi->contentp)
1475 type = OBJ_BAD;
1476 } else {
1477 type = unpack_object_header(p, &w_curs, &curpos, &size);
1478 }
1479
1480 if (!oi->contentp && oi->sizep) {
1481 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1482 off_t tmp_pos = curpos;
1483 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1484 type, obj_offset);
1485 if (!base_offset) {
1486 type = OBJ_BAD;
1487 goto out;
1488 }
1489 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1490 if (*oi->sizep == 0) {
1491 type = OBJ_BAD;
1492 goto out;
1493 }
1494 } else {
1495 *oi->sizep = size;
1496 }
1497 }
1498
1499 if (oi->disk_sizep) {
1500 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1501 *oi->disk_sizep = revidx[1].offset - obj_offset;
1502 }
1503
1504 if (oi->typep || oi->type_name) {
1505 enum object_type ptot;
1506 ptot = packed_to_object_type(r, p, obj_offset,
1507 type, &w_curs, curpos);
1508 if (oi->typep)
1509 *oi->typep = ptot;
1510 if (oi->type_name) {
1511 const char *tn = type_name(ptot);
1512 if (tn)
1513 strbuf_addstr(oi->type_name, tn);
1514 }
1515 if (ptot < 0) {
1516 type = OBJ_BAD;
1517 goto out;
1518 }
1519 }
1520
1521 if (oi->delta_base_sha1) {
1522 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1523 const unsigned char *base;
1524
1525 base = get_delta_base_sha1(p, &w_curs, curpos,
1526 type, obj_offset);
1527 if (!base) {
1528 type = OBJ_BAD;
1529 goto out;
1530 }
1531
1532 hashcpy(oi->delta_base_sha1, base);
1533 } else
1534 hashclr(oi->delta_base_sha1);
1535 }
1536
1537 oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
1538 OI_PACKED;
1539
1540 out:
1541 unuse_pack(&w_curs);
1542 return type;
1543 }
1544
1545 static void *unpack_compressed_entry(struct packed_git *p,
1546 struct pack_window **w_curs,
1547 off_t curpos,
1548 unsigned long size)
1549 {
1550 int st;
1551 git_zstream stream;
1552 unsigned char *buffer, *in;
1553
1554 buffer = xmallocz_gently(size);
1555 if (!buffer)
1556 return NULL;
1557 memset(&stream, 0, sizeof(stream));
1558 stream.next_out = buffer;
1559 stream.avail_out = size + 1;
1560
1561 git_inflate_init(&stream);
1562 do {
1563 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1564 stream.next_in = in;
1565 st = git_inflate(&stream, Z_FINISH);
1566 if (!stream.avail_out)
1567 break; /* the payload is larger than it should be */
1568 curpos += stream.next_in - in;
1569 } while (st == Z_OK || st == Z_BUF_ERROR);
1570 git_inflate_end(&stream);
1571 if ((st != Z_STREAM_END) || stream.total_out != size) {
1572 free(buffer);
1573 return NULL;
1574 }
1575
1576 /* versions of zlib can clobber unconsumed portion of outbuf */
1577 buffer[size] = '\0';
1578
1579 return buffer;
1580 }
1581
1582 static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1583 {
1584 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
1585 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
1586 p->pack_name, (uintmax_t)obj_offset);
1587 }
1588
1589 int do_check_packed_object_crc;
1590
1591 #define UNPACK_ENTRY_STACK_PREALLOC 64
1592 struct unpack_entry_stack_ent {
1593 off_t obj_offset;
1594 off_t curpos;
1595 unsigned long size;
1596 };
1597
1598 static void *read_object(struct repository *r,
1599 const struct object_id *oid,
1600 enum object_type *type,
1601 unsigned long *size)
1602 {
1603 struct object_info oi = OBJECT_INFO_INIT;
1604 void *content;
1605 oi.typep = type;
1606 oi.sizep = size;
1607 oi.contentp = &content;
1608
1609 if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1610 return NULL;
1611 return content;
1612 }
1613
1614 void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
1615 enum object_type *final_type, unsigned long *final_size)
1616 {
1617 struct pack_window *w_curs = NULL;
1618 off_t curpos = obj_offset;
1619 void *data = NULL;
1620 unsigned long size;
1621 enum object_type type;
1622 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
1623 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
1624 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
1625 int base_from_cache = 0;
1626
1627 write_pack_access_log(p, obj_offset);
1628
1629 /* PHASE 1: drill down to the innermost base object */
1630 for (;;) {
1631 off_t base_offset;
1632 int i;
1633 struct delta_base_cache_entry *ent;
1634
1635 ent = get_delta_base_cache_entry(p, curpos);
1636 if (ent) {
1637 type = ent->type;
1638 data = ent->data;
1639 size = ent->size;
1640 detach_delta_base_cache_entry(ent);
1641 base_from_cache = 1;
1642 break;
1643 }
1644
1645 if (do_check_packed_object_crc && p->index_version > 1) {
1646 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1647 off_t len = revidx[1].offset - obj_offset;
1648 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1649 struct object_id oid;
1650 nth_packed_object_oid(&oid, p, revidx->nr);
1651 error("bad packed object CRC for %s",
1652 oid_to_hex(&oid));
1653 mark_bad_packed_object(p, oid.hash);
1654 data = NULL;
1655 goto out;
1656 }
1657 }
1658
1659 type = unpack_object_header(p, &w_curs, &curpos, &size);
1660 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
1661 break;
1662
1663 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1664 if (!base_offset) {
1665 error("failed to validate delta base reference "
1666 "at offset %"PRIuMAX" from %s",
1667 (uintmax_t)curpos, p->pack_name);
1668 /* bail to phase 2, in hopes of recovery */
1669 data = NULL;
1670 break;
1671 }
1672
1673 /* push object, proceed to base */
1674 if (delta_stack_nr >= delta_stack_alloc
1675 && delta_stack == small_delta_stack) {
1676 delta_stack_alloc = alloc_nr(delta_stack_nr);
1677 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
1678 memcpy(delta_stack, small_delta_stack,
1679 sizeof(*delta_stack)*delta_stack_nr);
1680 } else {
1681 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
1682 }
1683 i = delta_stack_nr++;
1684 delta_stack[i].obj_offset = obj_offset;
1685 delta_stack[i].curpos = curpos;
1686 delta_stack[i].size = size;
1687
1688 curpos = obj_offset = base_offset;
1689 }
1690
1691 /* PHASE 2: handle the base */
1692 switch (type) {
1693 case OBJ_OFS_DELTA:
1694 case OBJ_REF_DELTA:
1695 if (data)
1696 BUG("unpack_entry: left loop at a valid delta");
1697 break;
1698 case OBJ_COMMIT:
1699 case OBJ_TREE:
1700 case OBJ_BLOB:
1701 case OBJ_TAG:
1702 if (!base_from_cache)
1703 data = unpack_compressed_entry(p, &w_curs, curpos, size);
1704 break;
1705 default:
1706 data = NULL;
1707 error("unknown object type %i at offset %"PRIuMAX" in %s",
1708 type, (uintmax_t)obj_offset, p->pack_name);
1709 }
1710
1711 /* PHASE 3: apply deltas in order */
1712
1713 /* invariants:
1714 * 'data' holds the base data, or NULL if there was corruption
1715 */
1716 while (delta_stack_nr) {
1717 void *delta_data;
1718 void *base = data;
1719 void *external_base = NULL;
1720 unsigned long delta_size, base_size = size;
1721 int i;
1722
1723 data = NULL;
1724
1725 if (base)
1726 add_delta_base_cache(p, obj_offset, base, base_size, type);
1727
1728 if (!base) {
1729 /*
1730 * We're probably in deep shit, but let's try to fetch
1731 * the required base anyway from another pack or loose.
1732 * This is costly but should happen only in the presence
1733 * of a corrupted pack, and is better than failing outright.
1734 */
1735 struct revindex_entry *revidx;
1736 struct object_id base_oid;
1737 revidx = find_pack_revindex(p, obj_offset);
1738 if (revidx) {
1739 nth_packed_object_oid(&base_oid, p, revidx->nr);
1740 error("failed to read delta base object %s"
1741 " at offset %"PRIuMAX" from %s",
1742 oid_to_hex(&base_oid), (uintmax_t)obj_offset,
1743 p->pack_name);
1744 mark_bad_packed_object(p, base_oid.hash);
1745 base = read_object(r, &base_oid, &type, &base_size);
1746 external_base = base;
1747 }
1748 }
1749
1750 i = --delta_stack_nr;
1751 obj_offset = delta_stack[i].obj_offset;
1752 curpos = delta_stack[i].curpos;
1753 delta_size = delta_stack[i].size;
1754
1755 if (!base)
1756 continue;
1757
1758 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
1759
1760 if (!delta_data) {
1761 error("failed to unpack compressed delta "
1762 "at offset %"PRIuMAX" from %s",
1763 (uintmax_t)curpos, p->pack_name);
1764 data = NULL;
1765 free(external_base);
1766 continue;
1767 }
1768
1769 data = patch_delta(base, base_size,
1770 delta_data, delta_size,
1771 &size);
1772
1773 /*
1774 * We could not apply the delta; warn the user, but keep going.
1775 * Our failure will be noticed either in the next iteration of
1776 * the loop, or if this is the final delta, in the caller when
1777 * we return NULL. Those code paths will take care of making
1778 * a more explicit warning and retrying with another copy of
1779 * the object.
1780 */
1781 if (!data)
1782 error("failed to apply delta");
1783
1784 free(delta_data);
1785 free(external_base);
1786 }
1787
1788 if (final_type)
1789 *final_type = type;
1790 if (final_size)
1791 *final_size = size;
1792
1793 out:
1794 unuse_pack(&w_curs);
1795
1796 if (delta_stack != small_delta_stack)
1797 free(delta_stack);
1798
1799 return data;
1800 }
1801
1802 int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
1803 {
1804 const unsigned char *index_fanout = p->index_data;
1805 const unsigned char *index_lookup;
1806 const unsigned int hashsz = the_hash_algo->rawsz;
1807 int index_lookup_width;
1808
1809 if (!index_fanout)
1810 BUG("bsearch_pack called without a valid pack-index");
1811
1812 index_lookup = index_fanout + 4 * 256;
1813 if (p->index_version == 1) {
1814 index_lookup_width = hashsz + 4;
1815 index_lookup += 4;
1816 } else {
1817 index_lookup_width = hashsz;
1818 index_fanout += 8;
1819 index_lookup += 8;
1820 }
1821
1822 return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
1823 index_lookup, index_lookup_width, result);
1824 }
1825
1826 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1827 uint32_t n)
1828 {
1829 const unsigned char *index = p->index_data;
1830 const unsigned int hashsz = the_hash_algo->rawsz;
1831 if (!index) {
1832 if (open_pack_index(p))
1833 return NULL;
1834 index = p->index_data;
1835 }
1836 if (n >= p->num_objects)
1837 return NULL;
1838 index += 4 * 256;
1839 if (p->index_version == 1) {
1840 return index + (hashsz + 4) * n + 4;
1841 } else {
1842 index += 8;
1843 return index + hashsz * n;
1844 }
1845 }
1846
1847 const struct object_id *nth_packed_object_oid(struct object_id *oid,
1848 struct packed_git *p,
1849 uint32_t n)
1850 {
1851 const unsigned char *hash = nth_packed_object_sha1(p, n);
1852 if (!hash)
1853 return NULL;
1854 hashcpy(oid->hash, hash);
1855 return oid;
1856 }
1857
1858 void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
1859 {
1860 const unsigned char *ptr = vptr;
1861 const unsigned char *start = p->index_data;
1862 const unsigned char *end = start + p->index_size;
1863 if (ptr < start)
1864 die(_("offset before start of pack index for %s (corrupt index?)"),
1865 p->pack_name);
1866 /* No need to check for underflow; .idx files must be at least 8 bytes */
1867 if (ptr >= end - 8)
1868 die(_("offset beyond end of pack index for %s (truncated index?)"),
1869 p->pack_name);
1870 }
1871
1872 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1873 {
1874 const unsigned char *index = p->index_data;
1875 const unsigned int hashsz = the_hash_algo->rawsz;
1876 index += 4 * 256;
1877 if (p->index_version == 1) {
1878 return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
1879 } else {
1880 uint32_t off;
1881 index += 8 + p->num_objects * (hashsz + 4);
1882 off = ntohl(*((uint32_t *)(index + 4 * n)));
1883 if (!(off & 0x80000000))
1884 return off;
1885 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1886 check_pack_index_ptr(p, index);
1887 return get_be64(index);
1888 }
1889 }
1890
1891 off_t find_pack_entry_one(const unsigned char *sha1,
1892 struct packed_git *p)
1893 {
1894 const unsigned char *index = p->index_data;
1895 struct object_id oid;
1896 uint32_t result;
1897
1898 if (!index) {
1899 if (open_pack_index(p))
1900 return 0;
1901 }
1902
1903 hashcpy(oid.hash, sha1);
1904 if (bsearch_pack(&oid, p, &result))
1905 return nth_packed_object_offset(p, result);
1906 return 0;
1907 }
1908
1909 int is_pack_valid(struct packed_git *p)
1910 {
1911 /* An already open pack is known to be valid. */
1912 if (p->pack_fd != -1)
1913 return 1;
1914
1915 /* If the pack has one window completely covering the
1916 * file size, the pack is known to be valid even if
1917 * the descriptor is not currently open.
1918 */
1919 if (p->windows) {
1920 struct pack_window *w = p->windows;
1921
1922 if (!w->offset && w->len == p->pack_size)
1923 return 1;
1924 }
1925
1926 /* Force the pack to open to prove its valid. */
1927 return !open_packed_git(p);
1928 }
1929
1930 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1931 struct packed_git *packs)
1932 {
1933 struct packed_git *p;
1934
1935 for (p = packs; p; p = p->next) {
1936 if (find_pack_entry_one(sha1, p))
1937 return p;
1938 }
1939 return NULL;
1940
1941 }
1942
1943 static int fill_pack_entry(const struct object_id *oid,
1944 struct pack_entry *e,
1945 struct packed_git *p)
1946 {
1947 off_t offset;
1948
1949 if (p->num_bad_objects) {
1950 unsigned i;
1951 for (i = 0; i < p->num_bad_objects; i++)
1952 if (hasheq(oid->hash,
1953 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1954 return 0;
1955 }
1956
1957 offset = find_pack_entry_one(oid->hash, p);
1958 if (!offset)
1959 return 0;
1960
1961 /*
1962 * We are about to tell the caller where they can locate the
1963 * requested object. We better make sure the packfile is
1964 * still here and can be accessed before supplying that
1965 * answer, as it may have been deleted since the index was
1966 * loaded!
1967 */
1968 if (!is_pack_valid(p))
1969 return 0;
1970 e->offset = offset;
1971 e->p = p;
1972 return 1;
1973 }
1974
1975 int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
1976 {
1977 struct list_head *pos;
1978 struct multi_pack_index *m;
1979
1980 prepare_packed_git(r);
1981 if (!r->objects->packed_git && !r->objects->multi_pack_index)
1982 return 0;
1983
1984 for (m = r->objects->multi_pack_index; m; m = m->next) {
1985 if (fill_midx_entry(oid, e, m))
1986 return 1;
1987 }
1988
1989 list_for_each(pos, &r->objects->packed_git_mru) {
1990 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1991 if (fill_pack_entry(oid, e, p)) {
1992 list_move(&p->mru, &r->objects->packed_git_mru);
1993 return 1;
1994 }
1995 }
1996 return 0;
1997 }
1998
1999 int has_object_pack(const struct object_id *oid)
2000 {
2001 struct pack_entry e;
2002 return find_pack_entry(the_repository, oid, &e);
2003 }
2004
2005 int has_pack_index(const unsigned char *sha1)
2006 {
2007 struct stat st;
2008 if (stat(sha1_pack_index_name(sha1), &st))
2009 return 0;
2010 return 1;
2011 }
2012
2013 int for_each_object_in_pack(struct packed_git *p,
2014 each_packed_object_fn cb, void *data,
2015 enum for_each_object_flags flags)
2016 {
2017 uint32_t i;
2018 int r = 0;
2019
2020 if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2021 load_pack_revindex(p);
2022
2023 for (i = 0; i < p->num_objects; i++) {
2024 uint32_t pos;
2025 struct object_id oid;
2026
2027 if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2028 pos = p->revindex[i].nr;
2029 else
2030 pos = i;
2031
2032 if (!nth_packed_object_oid(&oid, p, pos))
2033 return error("unable to get sha1 of object %u in %s",
2034 pos, p->pack_name);
2035
2036 r = cb(&oid, p, pos, data);
2037 if (r)
2038 break;
2039 }
2040 return r;
2041 }
2042
2043 int for_each_packed_object(each_packed_object_fn cb, void *data,
2044 enum for_each_object_flags flags)
2045 {
2046 struct packed_git *p;
2047 int r = 0;
2048 int pack_errors = 0;
2049
2050 prepare_packed_git(the_repository);
2051 for (p = get_all_packs(the_repository); p; p = p->next) {
2052 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
2053 continue;
2054 if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
2055 !p->pack_promisor)
2056 continue;
2057 if (open_pack_index(p)) {
2058 pack_errors = 1;
2059 continue;
2060 }
2061 r = for_each_object_in_pack(p, cb, data, flags);
2062 if (r)
2063 break;
2064 }
2065 return r ? r : pack_errors;
2066 }
2067
2068 static int add_promisor_object(const struct object_id *oid,
2069 struct packed_git *pack,
2070 uint32_t pos,
2071 void *set_)
2072 {
2073 struct oidset *set = set_;
2074 struct object *obj = parse_object(the_repository, oid);
2075 if (!obj)
2076 return 1;
2077
2078 oidset_insert(set, oid);
2079
2080 /*
2081 * If this is a tree, commit, or tag, the objects it refers
2082 * to are also promisor objects. (Blobs refer to no objects->)
2083 */
2084 if (obj->type == OBJ_TREE) {
2085 struct tree *tree = (struct tree *)obj;
2086 struct tree_desc desc;
2087 struct name_entry entry;
2088 if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
2089 /*
2090 * Error messages are given when packs are
2091 * verified, so do not print any here.
2092 */
2093 return 0;
2094 while (tree_entry_gently(&desc, &entry))
2095 oidset_insert(set, entry.oid);
2096 } else if (obj->type == OBJ_COMMIT) {
2097 struct commit *commit = (struct commit *) obj;
2098 struct commit_list *parents = commit->parents;
2099
2100 oidset_insert(set, get_commit_tree_oid(commit));
2101 for (; parents; parents = parents->next)
2102 oidset_insert(set, &parents->item->object.oid);
2103 } else if (obj->type == OBJ_TAG) {
2104 struct tag *tag = (struct tag *) obj;
2105 oidset_insert(set, &tag->tagged->oid);
2106 }
2107 return 0;
2108 }
2109
2110 int is_promisor_object(const struct object_id *oid)
2111 {
2112 static struct oidset promisor_objects;
2113 static int promisor_objects_prepared;
2114
2115 if (!promisor_objects_prepared) {
2116 if (repository_format_partial_clone) {
2117 for_each_packed_object(add_promisor_object,
2118 &promisor_objects,
2119 FOR_EACH_OBJECT_PROMISOR_ONLY);
2120 }
2121 promisor_objects_prepared = 1;
2122 }
2123 return oidset_contains(&promisor_objects, oid);
2124 }
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