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