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 if (o->multi_pack_index) {
350 close_midx(o->multi_pack_index);
351 o->multi_pack_index = NULL;
352 }
353}
354/*
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 */
359static 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 /*
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 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 if (w->last_used > this_mru_w->last_used)
387 this_mru_w = w;
388 /*
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 /*
403 * Select this pack.
404 */
405 *mru_w = this_mru_w;
406 *lru_p = p;
407 *accept_windows_inuse = has_windows_inuse;
408}
409static 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 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 if (lru_p)
423 return close_pack_fd(lru_p);
424 return 0;
426}
427static unsigned int get_max_fd_limit(void)
429{
430#ifdef RLIMIT_NOFILE
431 {
432 struct rlimit lim;
433 if (!getrlimit(RLIMIT_NOFILE, &lim))
435 return lim.rlim_cur;
436 }
437#endif
438#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#ifdef OPEN_MAX
463 return OPEN_MAX;
464#else
465 return 1; /* see the caller ;-) */
466#endif
467}
468/*
470 * Do not call this directly as this leaks p->pack_fd on error return;
471 * call open_packed_git() instead.
472 */
473static 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 if (!p->index_data) {
484 struct multi_pack_index *m;
485 const char *pack_name = strrchr(p->pack_name, '/');
486 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 if (!m && open_pack_index(p))
494 return error("packfile %s index unavailable", p->pack_name);
495 }
496 if (!pack_max_fds) {
498 unsigned int max_fds = get_max_fd_limit();
499 /* 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 while (pack_max_fds <= pack_open_fds && close_one_pack())
508 ; /* nothing */
509 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 /* 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 /* 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 /* 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 /* Skip index checking if in multi-pack-index */
547 if (!p->index_data)
548 return 0;
549 /* 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}
568static 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}
576static 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}
589unsigned 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 /* 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 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 if (p->pack_fd == -1 && open_packed_git(p))
621 die("packfile %s cannot be accessed", p->pack_name);
622 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}
662void 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}
671static void try_to_free_pack_memory(size_t size)
673{
674 release_pack_memory(size);
675}
676struct 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 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 /*
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 /*
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 xsnprintf(p->pack_name + path_len, alloc - path_len, ".keep");
705 if (!access(p->pack_name, F_OK))
706 p->pack_keep = 1;
707 xsnprintf(p->pack_name + path_len, alloc - path_len, ".promisor");
709 if (!access(p->pack_name, F_OK))
710 p->pack_promisor = 1;
711 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 /* 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}
729void install_packed_git(struct repository *r, struct packed_git *pack)
731{
732 if (pack->pack_fd != -1)
733 pack_open_fds++;
734 pack->next = r->objects->packed_git;
736 r->objects->packed_git = pack;
737}
738void (*report_garbage)(unsigned seen_bits, const char *path);
740static 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 for (; first < last; first++)
748 report_garbage(seen_bits, list->items[first].string);
749}
750static void report_pack_garbage(struct string_list *list)
752{
753 int i, baselen = -1, first = 0, seen_bits = 0;
754 if (!report_garbage)
756 return;
757 string_list_sort(list);
759 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}
784void 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 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 strbuf_setlen(&path, dirnamelen);
811 strbuf_addstr(&path, de->d_name);
812 fn(path.buf, path.len, de->d_name, data);
814 }
815 closedir(dir);
817 strbuf_release(&path);
818}
819struct prepare_pack_data {
821 struct repository *r;
822 struct string_list *garbage;
823 int local;
824 struct multi_pack_index *m;
825};
826static 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 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 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 if (!report_garbage)
853 return;
854 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}
866static 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 data.m = r->objects->multi_pack_index;
873 /* 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 data.r = r;
879 data.garbage = &garbage;
880 data.local = local;
881 for_each_file_in_pack_dir(objdir, prepare_pack, &data);
883 report_pack_garbage(data.garbage);
885 string_list_clear(data.garbage, 0);
886}
887static 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 */
896unsigned 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 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}
916static void *get_next_packed_git(const void *p)
918{
919 return ((const struct packed_git *)p)->next;
920}
921static void set_next_packed_git(void *p, void *next)
923{
924 ((struct packed_git *)p)->next = next;
925}
926static 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 /*
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 /*
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}
954static 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}
961static void prepare_packed_git_mru(struct repository *r)
963{
964 struct packed_git *p;
965 INIT_LIST_HEAD(&r->objects->packed_git_mru);
967 for (p = r->objects->packed_git; p; p = p->next)
969 list_add_tail(&p->mru, &r->objects->packed_git_mru);
970}
971static void prepare_packed_git(struct repository *r)
973{
974 struct object_directory *odb;
975 if (r->objects->packed_git_initialized)
977 return;
978 prepare_alt_odb(r);
980 for (odb = r->objects->odb; odb; odb = odb->next) {
981 int local = (odb == r->objects->odb);
982 prepare_multi_pack_index_one(r, odb->path, local);
983 prepare_packed_git_one(r, odb->path, local);
984 }
985 rearrange_packed_git(r);
986 r->objects->all_packs = NULL;
988 prepare_packed_git_mru(r);
990 r->objects->packed_git_initialized = 1;
991}
992void reprepare_packed_git(struct repository *r)
994{
995 struct object_directory *odb;
996 for (odb = r->objects->odb; odb; odb = odb->next)
998 odb_clear_loose_cache(odb);
999 r->objects->approximate_object_count_valid = 0;
1001 r->objects->packed_git_initialized = 0;
1002 prepare_packed_git(r);
1003}
1004struct packed_git *get_packed_git(struct repository *r)
1006{
1007 prepare_packed_git(r);
1008 return r->objects->packed_git;
1009}
1010struct multi_pack_index *get_multi_pack_index(struct repository *r)
1012{
1013 prepare_packed_git(r);
1014 return r->objects->multi_pack_index;
1015}
1016struct packed_git *get_all_packs(struct repository *r)
1018{
1019 prepare_packed_git(r);
1020 if (!r->objects->all_packs) {
1022 struct packed_git *p = r->objects->packed_git;
1023 struct multi_pack_index *m;
1024 for (m = r->objects->multi_pack_index; m; m = m->next) {
1026 uint32_t i;
1027 for (i = 0; i < m->num_packs; i++) {
1028 if (!prepare_midx_pack(m, i)) {
1029 m->packs[i]->next = p;
1030 p = m->packs[i];
1031 }
1032 }
1033 }
1034 r->objects->all_packs = p;
1036 }
1037 return r->objects->all_packs;
1039}
1040struct list_head *get_packed_git_mru(struct repository *r)
1042{
1043 prepare_packed_git(r);
1044 return &r->objects->packed_git_mru;
1045}
1046unsigned long unpack_object_header_buffer(const unsigned char *buf,
1048 unsigned long len, enum object_type *type, unsigned long *sizep)
1049{
1050 unsigned shift;
1051 unsigned long size, c;
1052 unsigned long used = 0;
1053 c = buf[used++];
1055 *type = (c >> 4) & 7;
1056 size = c & 15;
1057 shift = 4;
1058 while (c & 0x80) {
1059 if (len <= used || bitsizeof(long) <= shift) {
1060 error("bad object header");
1061 size = used = 0;
1062 break;
1063 }
1064 c = buf[used++];
1065 size += (c & 0x7f) << shift;
1066 shift += 7;
1067 }
1068 *sizep = size;
1069 return used;
1070}
1071unsigned long get_size_from_delta(struct packed_git *p,
1073 struct pack_window **w_curs,
1074 off_t curpos)
1075{
1076 const unsigned char *data;
1077 unsigned char delta_head[20], *in;
1078 git_zstream stream;
1079 int st;
1080 memset(&stream, 0, sizeof(stream));
1082 stream.next_out = delta_head;
1083 stream.avail_out = sizeof(delta_head);
1084 git_inflate_init(&stream);
1086 do {
1087 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1088 stream.next_in = in;
1089 st = git_inflate(&stream, Z_FINISH);
1090 curpos += stream.next_in - in;
1091 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1092 stream.total_out < sizeof(delta_head));
1093 git_inflate_end(&stream);
1094 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1095 error("delta data unpack-initial failed");
1096 return 0;
1097 }
1098 /* Examine the initial part of the delta to figure out
1100 * the result size.
1101 */
1102 data = delta_head;
1103 /* ignore base size */
1105 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1106 /* Read the result size */
1108 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1109}
1110int unpack_object_header(struct packed_git *p,
1112 struct pack_window **w_curs,
1113 off_t *curpos,
1114 unsigned long *sizep)
1115{
1116 unsigned char *base;
1117 unsigned long left;
1118 unsigned long used;
1119 enum object_type type;
1120 /* use_pack() assures us we have [base, base + 20) available
1122 * as a range that we can look at. (Its actually the hash
1123 * size that is assured.) With our object header encoding
1124 * the maximum deflated object size is 2^137, which is just
1125 * insane, so we know won't exceed what we have been given.
1126 */
1127 base = use_pack(p, w_curs, *curpos, &left);
1128 used = unpack_object_header_buffer(base, left, &type, sizep);
1129 if (!used) {
1130 type = OBJ_BAD;
1131 } else
1132 *curpos += used;
1133 return type;
1135}
1136void mark_bad_packed_object(struct packed_git *p, const unsigned char *sha1)
1138{
1139 unsigned i;
1140 const unsigned hashsz = the_hash_algo->rawsz;
1141 for (i = 0; i < p->num_bad_objects; i++)
1142 if (hasheq(sha1, p->bad_object_sha1 + hashsz * i))
1143 return;
1144 p->bad_object_sha1 = xrealloc(p->bad_object_sha1,
1145 st_mult(GIT_MAX_RAWSZ,
1146 st_add(p->num_bad_objects, 1)));
1147 hashcpy(p->bad_object_sha1 + hashsz * p->num_bad_objects, sha1);
1148 p->num_bad_objects++;
1149}
1150const struct packed_git *has_packed_and_bad(const unsigned char *sha1)
1152{
1153 struct packed_git *p;
1154 unsigned i;
1155 for (p = the_repository->objects->packed_git; p; p = p->next)
1157 for (i = 0; i < p->num_bad_objects; i++)
1158 if (hasheq(sha1,
1159 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1160 return p;
1161 return NULL;
1162}
1163static off_t get_delta_base(struct packed_git *p,
1165 struct pack_window **w_curs,
1166 off_t *curpos,
1167 enum object_type type,
1168 off_t delta_obj_offset)
1169{
1170 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1171 off_t base_offset;
1172 /* use_pack() assured us we have [base_info, base_info + 20)
1174 * as a range that we can look at without walking off the
1175 * end of the mapped window. Its actually the hash size
1176 * that is assured. An OFS_DELTA longer than the hash size
1177 * is stupid, as then a REF_DELTA would be smaller to store.
1178 */
1179 if (type == OBJ_OFS_DELTA) {
1180 unsigned used = 0;
1181 unsigned char c = base_info[used++];
1182 base_offset = c & 127;
1183 while (c & 128) {
1184 base_offset += 1;
1185 if (!base_offset || MSB(base_offset, 7))
1186 return 0; /* overflow */
1187 c = base_info[used++];
1188 base_offset = (base_offset << 7) + (c & 127);
1189 }
1190 base_offset = delta_obj_offset - base_offset;
1191 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1192 return 0; /* out of bound */
1193 *curpos += used;
1194 } else if (type == OBJ_REF_DELTA) {
1195 /* The base entry _must_ be in the same pack */
1196 base_offset = find_pack_entry_one(base_info, p);
1197 *curpos += the_hash_algo->rawsz;
1198 } else
1199 die("I am totally screwed");
1200 return base_offset;
1201}
1202/*
1204 * Like get_delta_base above, but we return the sha1 instead of the pack
1205 * offset. This means it is cheaper for REF deltas (we do not have to do
1206 * the final object lookup), but more expensive for OFS deltas (we
1207 * have to load the revidx to convert the offset back into a sha1).
1208 */
1209static const unsigned char *get_delta_base_sha1(struct packed_git *p,
1210 struct pack_window **w_curs,
1211 off_t curpos,
1212 enum object_type type,
1213 off_t delta_obj_offset)
1214{
1215 if (type == OBJ_REF_DELTA) {
1216 unsigned char *base = use_pack(p, w_curs, curpos, NULL);
1217 return base;
1218 } else if (type == OBJ_OFS_DELTA) {
1219 struct revindex_entry *revidx;
1220 off_t base_offset = get_delta_base(p, w_curs, &curpos,
1221 type, delta_obj_offset);
1222 if (!base_offset)
1224 return NULL;
1225 revidx = find_pack_revindex(p, base_offset);
1227 if (!revidx)
1228 return NULL;
1229 return nth_packed_object_sha1(p, revidx->nr);
1231 } else
1232 return NULL;
1233}
1234static int retry_bad_packed_offset(struct repository *r,
1236 struct packed_git *p,
1237 off_t obj_offset)
1238{
1239 int type;
1240 struct revindex_entry *revidx;
1241 struct object_id oid;
1242 revidx = find_pack_revindex(p, obj_offset);
1243 if (!revidx)
1244 return OBJ_BAD;
1245 nth_packed_object_oid(&oid, p, revidx->nr);
1246 mark_bad_packed_object(p, oid.hash);
1247 type = oid_object_info(r, &oid, NULL);
1248 if (type <= OBJ_NONE)
1249 return OBJ_BAD;
1250 return type;
1251}
1252#define POI_STACK_PREALLOC 64
1254static enum object_type packed_to_object_type(struct repository *r,
1256 struct packed_git *p,
1257 off_t obj_offset,
1258 enum object_type type,
1259 struct pack_window **w_curs,
1260 off_t curpos)
1261{
1262 off_t small_poi_stack[POI_STACK_PREALLOC];
1263 off_t *poi_stack = small_poi_stack;
1264 int poi_stack_nr = 0, poi_stack_alloc = POI_STACK_PREALLOC;
1265 while (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1267 off_t base_offset;
1268 unsigned long size;
1269 /* Push the object we're going to leave behind */
1270 if (poi_stack_nr >= poi_stack_alloc && poi_stack == small_poi_stack) {
1271 poi_stack_alloc = alloc_nr(poi_stack_nr);
1272 ALLOC_ARRAY(poi_stack, poi_stack_alloc);
1273 memcpy(poi_stack, small_poi_stack, sizeof(off_t)*poi_stack_nr);
1274 } else {
1275 ALLOC_GROW(poi_stack, poi_stack_nr+1, poi_stack_alloc);
1276 }
1277 poi_stack[poi_stack_nr++] = obj_offset;
1278 /* If parsing the base offset fails, just unwind */
1279 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1280 if (!base_offset)
1281 goto unwind;
1282 curpos = obj_offset = base_offset;
1283 type = unpack_object_header(p, w_curs, &curpos, &size);
1284 if (type <= OBJ_NONE) {
1285 /* If getting the base itself fails, we first
1286 * retry the base, otherwise unwind */
1287 type = retry_bad_packed_offset(r, p, base_offset);
1288 if (type > OBJ_NONE)
1289 goto out;
1290 goto unwind;
1291 }
1292 }
1293 switch (type) {
1295 case OBJ_BAD:
1296 case OBJ_COMMIT:
1297 case OBJ_TREE:
1298 case OBJ_BLOB:
1299 case OBJ_TAG:
1300 break;
1301 default:
1302 error("unknown object type %i at offset %"PRIuMAX" in %s",
1303 type, (uintmax_t)obj_offset, p->pack_name);
1304 type = OBJ_BAD;
1305 }
1306out:
1308 if (poi_stack != small_poi_stack)
1309 free(poi_stack);
1310 return type;
1311unwind:
1313 while (poi_stack_nr) {
1314 obj_offset = poi_stack[--poi_stack_nr];
1315 type = retry_bad_packed_offset(r, p, obj_offset);
1316 if (type > OBJ_NONE)
1317 goto out;
1318 }
1319 type = OBJ_BAD;
1320 goto out;
1321}
1322static struct hashmap delta_base_cache;
1324static size_t delta_base_cached;
1325static LIST_HEAD(delta_base_cache_lru);
1327struct delta_base_cache_key {
1329 struct packed_git *p;
1330 off_t base_offset;
1331};
1332struct delta_base_cache_entry {
1334 struct hashmap hash;
1335 struct delta_base_cache_key key;
1336 struct list_head lru;
1337 void *data;
1338 unsigned long size;
1339 enum object_type type;
1340};
1341static unsigned int pack_entry_hash(struct packed_git *p, off_t base_offset)
1343{
1344 unsigned int hash;
1345 hash = (unsigned int)(intptr_t)p + (unsigned int)base_offset;
1347 hash += (hash >> 8) + (hash >> 16);
1348 return hash;
1349}
1350static struct delta_base_cache_entry *
1352get_delta_base_cache_entry(struct packed_git *p, off_t base_offset)
1353{
1354 struct hashmap_entry entry;
1355 struct delta_base_cache_key key;
1356 if (!delta_base_cache.cmpfn)
1358 return NULL;
1359 hashmap_entry_init(&entry, pack_entry_hash(p, base_offset));
1361 key.p = p;
1362 key.base_offset = base_offset;
1363 return hashmap_get(&delta_base_cache, &entry, &key);
1364}
1365static int delta_base_cache_key_eq(const struct delta_base_cache_key *a,
1367 const struct delta_base_cache_key *b)
1368{
1369 return a->p == b->p && a->base_offset == b->base_offset;
1370}
1371static int delta_base_cache_hash_cmp(const void *unused_cmp_data,
1373 const void *va, const void *vb,
1374 const void *vkey)
1375{
1376 const struct delta_base_cache_entry *a = va, *b = vb;
1377 const struct delta_base_cache_key *key = vkey;
1378 if (key)
1379 return !delta_base_cache_key_eq(&a->key, key);
1380 else
1381 return !delta_base_cache_key_eq(&a->key, &b->key);
1382}
1383static int in_delta_base_cache(struct packed_git *p, off_t base_offset)
1385{
1386 return !!get_delta_base_cache_entry(p, base_offset);
1387}
1388/*
1390 * Remove the entry from the cache, but do _not_ free the associated
1391 * entry data. The caller takes ownership of the "data" buffer, and
1392 * should copy out any fields it wants before detaching.
1393 */
1394static void detach_delta_base_cache_entry(struct delta_base_cache_entry *ent)
1395{
1396 hashmap_remove(&delta_base_cache, ent, &ent->key);
1397 list_del(&ent->lru);
1398 delta_base_cached -= ent->size;
1399 free(ent);
1400}
1401static void *cache_or_unpack_entry(struct repository *r, struct packed_git *p,
1403 off_t base_offset, unsigned long *base_size,
1404 enum object_type *type)
1405{
1406 struct delta_base_cache_entry *ent;
1407 ent = get_delta_base_cache_entry(p, base_offset);
1409 if (!ent)
1410 return unpack_entry(r, p, base_offset, type, base_size);
1411 if (type)
1413 *type = ent->type;
1414 if (base_size)
1415 *base_size = ent->size;
1416 return xmemdupz(ent->data, ent->size);
1417}
1418static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1420{
1421 free(ent->data);
1422 detach_delta_base_cache_entry(ent);
1423}
1424void clear_delta_base_cache(void)
1426{
1427 struct list_head *lru, *tmp;
1428 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1429 struct delta_base_cache_entry *entry =
1430 list_entry(lru, struct delta_base_cache_entry, lru);
1431 release_delta_base_cache(entry);
1432 }
1433}
1434static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1436 void *base, unsigned long base_size, enum object_type type)
1437{
1438 struct delta_base_cache_entry *ent = xmalloc(sizeof(*ent));
1439 struct list_head *lru, *tmp;
1440 delta_base_cached += base_size;
1442 list_for_each_safe(lru, tmp, &delta_base_cache_lru) {
1444 struct delta_base_cache_entry *f =
1445 list_entry(lru, struct delta_base_cache_entry, lru);
1446 if (delta_base_cached <= delta_base_cache_limit)
1447 break;
1448 release_delta_base_cache(f);
1449 }
1450 ent->key.p = p;
1452 ent->key.base_offset = base_offset;
1453 ent->type = type;
1454 ent->data = base;
1455 ent->size = base_size;
1456 list_add_tail(&ent->lru, &delta_base_cache_lru);
1457 if (!delta_base_cache.cmpfn)
1459 hashmap_init(&delta_base_cache, delta_base_cache_hash_cmp, NULL, 0);
1460 hashmap_entry_init(ent, pack_entry_hash(p, base_offset));
1461 hashmap_add(&delta_base_cache, ent);
1462}
1463int packed_object_info(struct repository *r, struct packed_git *p,
1465 off_t obj_offset, struct object_info *oi)
1466{
1467 struct pack_window *w_curs = NULL;
1468 unsigned long size;
1469 off_t curpos = obj_offset;
1470 enum object_type type;
1471 /*
1473 * We always get the representation type, but only convert it to
1474 * a "real" type later if the caller is interested.
1475 */
1476 if (oi->contentp) {
1477 *oi->contentp = cache_or_unpack_entry(r, p, obj_offset, oi->sizep,
1478 &type);
1479 if (!*oi->contentp)
1480 type = OBJ_BAD;
1481 } else {
1482 type = unpack_object_header(p, &w_curs, &curpos, &size);
1483 }
1484 if (!oi->contentp && oi->sizep) {
1486 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1487 off_t tmp_pos = curpos;
1488 off_t base_offset = get_delta_base(p, &w_curs, &tmp_pos,
1489 type, obj_offset);
1490 if (!base_offset) {
1491 type = OBJ_BAD;
1492 goto out;
1493 }
1494 *oi->sizep = get_size_from_delta(p, &w_curs, tmp_pos);
1495 if (*oi->sizep == 0) {
1496 type = OBJ_BAD;
1497 goto out;
1498 }
1499 } else {
1500 *oi->sizep = size;
1501 }
1502 }
1503 if (oi->disk_sizep) {
1505 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1506 *oi->disk_sizep = revidx[1].offset - obj_offset;
1507 }
1508 if (oi->typep || oi->type_name) {
1510 enum object_type ptot;
1511 ptot = packed_to_object_type(r, p, obj_offset,
1512 type, &w_curs, curpos);
1513 if (oi->typep)
1514 *oi->typep = ptot;
1515 if (oi->type_name) {
1516 const char *tn = type_name(ptot);
1517 if (tn)
1518 strbuf_addstr(oi->type_name, tn);
1519 }
1520 if (ptot < 0) {
1521 type = OBJ_BAD;
1522 goto out;
1523 }
1524 }
1525 if (oi->delta_base_sha1) {
1527 if (type == OBJ_OFS_DELTA || type == OBJ_REF_DELTA) {
1528 const unsigned char *base;
1529 base = get_delta_base_sha1(p, &w_curs, curpos,
1531 type, obj_offset);
1532 if (!base) {
1533 type = OBJ_BAD;
1534 goto out;
1535 }
1536 hashcpy(oi->delta_base_sha1, base);
1538 } else
1539 hashclr(oi->delta_base_sha1);
1540 }
1541 oi->whence = in_delta_base_cache(p, obj_offset) ? OI_DBCACHED :
1543 OI_PACKED;
1544out:
1546 unuse_pack(&w_curs);
1547 return type;
1548}
1549static void *unpack_compressed_entry(struct packed_git *p,
1551 struct pack_window **w_curs,
1552 off_t curpos,
1553 unsigned long size)
1554{
1555 int st;
1556 git_zstream stream;
1557 unsigned char *buffer, *in;
1558 buffer = xmallocz_gently(size);
1560 if (!buffer)
1561 return NULL;
1562 memset(&stream, 0, sizeof(stream));
1563 stream.next_out = buffer;
1564 stream.avail_out = size + 1;
1565 git_inflate_init(&stream);
1567 do {
1568 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1569 stream.next_in = in;
1570 st = git_inflate(&stream, Z_FINISH);
1571 if (!stream.avail_out)
1572 break; /* the payload is larger than it should be */
1573 curpos += stream.next_in - in;
1574 } while (st == Z_OK || st == Z_BUF_ERROR);
1575 git_inflate_end(&stream);
1576 if ((st != Z_STREAM_END) || stream.total_out != size) {
1577 free(buffer);
1578 return NULL;
1579 }
1580 /* versions of zlib can clobber unconsumed portion of outbuf */
1582 buffer[size] = '\0';
1583 return buffer;
1585}
1586static void write_pack_access_log(struct packed_git *p, off_t obj_offset)
1588{
1589 static struct trace_key pack_access = TRACE_KEY_INIT(PACK_ACCESS);
1590 trace_printf_key(&pack_access, "%s %"PRIuMAX"\n",
1591 p->pack_name, (uintmax_t)obj_offset);
1592}
1593int do_check_packed_object_crc;
1595#define UNPACK_ENTRY_STACK_PREALLOC 64
1597struct unpack_entry_stack_ent {
1598 off_t obj_offset;
1599 off_t curpos;
1600 unsigned long size;
1601};
1602static void *read_object(struct repository *r,
1604 const struct object_id *oid,
1605 enum object_type *type,
1606 unsigned long *size)
1607{
1608 struct object_info oi = OBJECT_INFO_INIT;
1609 void *content;
1610 oi.typep = type;
1611 oi.sizep = size;
1612 oi.contentp = &content;
1613 if (oid_object_info_extended(r, oid, &oi, 0) < 0)
1615 return NULL;
1616 return content;
1617}
1618void *unpack_entry(struct repository *r, struct packed_git *p, off_t obj_offset,
1620 enum object_type *final_type, unsigned long *final_size)
1621{
1622 struct pack_window *w_curs = NULL;
1623 off_t curpos = obj_offset;
1624 void *data = NULL;
1625 unsigned long size;
1626 enum object_type type;
1627 struct unpack_entry_stack_ent small_delta_stack[UNPACK_ENTRY_STACK_PREALLOC];
1628 struct unpack_entry_stack_ent *delta_stack = small_delta_stack;
1629 int delta_stack_nr = 0, delta_stack_alloc = UNPACK_ENTRY_STACK_PREALLOC;
1630 int base_from_cache = 0;
1631 write_pack_access_log(p, obj_offset);
1633 /* PHASE 1: drill down to the innermost base object */
1635 for (;;) {
1636 off_t base_offset;
1637 int i;
1638 struct delta_base_cache_entry *ent;
1639 ent = get_delta_base_cache_entry(p, curpos);
1641 if (ent) {
1642 type = ent->type;
1643 data = ent->data;
1644 size = ent->size;
1645 detach_delta_base_cache_entry(ent);
1646 base_from_cache = 1;
1647 break;
1648 }
1649 if (do_check_packed_object_crc && p->index_version > 1) {
1651 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1652 off_t len = revidx[1].offset - obj_offset;
1653 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1654 struct object_id oid;
1655 nth_packed_object_oid(&oid, p, revidx->nr);
1656 error("bad packed object CRC for %s",
1657 oid_to_hex(&oid));
1658 mark_bad_packed_object(p, oid.hash);
1659 data = NULL;
1660 goto out;
1661 }
1662 }
1663 type = unpack_object_header(p, &w_curs, &curpos, &size);
1665 if (type != OBJ_OFS_DELTA && type != OBJ_REF_DELTA)
1666 break;
1667 base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1669 if (!base_offset) {
1670 error("failed to validate delta base reference "
1671 "at offset %"PRIuMAX" from %s",
1672 (uintmax_t)curpos, p->pack_name);
1673 /* bail to phase 2, in hopes of recovery */
1674 data = NULL;
1675 break;
1676 }
1677 /* push object, proceed to base */
1679 if (delta_stack_nr >= delta_stack_alloc
1680 && delta_stack == small_delta_stack) {
1681 delta_stack_alloc = alloc_nr(delta_stack_nr);
1682 ALLOC_ARRAY(delta_stack, delta_stack_alloc);
1683 memcpy(delta_stack, small_delta_stack,
1684 sizeof(*delta_stack)*delta_stack_nr);
1685 } else {
1686 ALLOC_GROW(delta_stack, delta_stack_nr+1, delta_stack_alloc);
1687 }
1688 i = delta_stack_nr++;
1689 delta_stack[i].obj_offset = obj_offset;
1690 delta_stack[i].curpos = curpos;
1691 delta_stack[i].size = size;
1692 curpos = obj_offset = base_offset;
1694 }
1695 /* PHASE 2: handle the base */
1697 switch (type) {
1698 case OBJ_OFS_DELTA:
1699 case OBJ_REF_DELTA:
1700 if (data)
1701 BUG("unpack_entry: left loop at a valid delta");
1702 break;
1703 case OBJ_COMMIT:
1704 case OBJ_TREE:
1705 case OBJ_BLOB:
1706 case OBJ_TAG:
1707 if (!base_from_cache)
1708 data = unpack_compressed_entry(p, &w_curs, curpos, size);
1709 break;
1710 default:
1711 data = NULL;
1712 error("unknown object type %i at offset %"PRIuMAX" in %s",
1713 type, (uintmax_t)obj_offset, p->pack_name);
1714 }
1715 /* PHASE 3: apply deltas in order */
1717 /* invariants:
1719 * 'data' holds the base data, or NULL if there was corruption
1720 */
1721 while (delta_stack_nr) {
1722 void *delta_data;
1723 void *base = data;
1724 void *external_base = NULL;
1725 unsigned long delta_size, base_size = size;
1726 int i;
1727 data = NULL;
1729 if (base)
1731 add_delta_base_cache(p, obj_offset, base, base_size, type);
1732 if (!base) {
1734 /*
1735 * We're probably in deep shit, but let's try to fetch
1736 * the required base anyway from another pack or loose.
1737 * This is costly but should happen only in the presence
1738 * of a corrupted pack, and is better than failing outright.
1739 */
1740 struct revindex_entry *revidx;
1741 struct object_id base_oid;
1742 revidx = find_pack_revindex(p, obj_offset);
1743 if (revidx) {
1744 nth_packed_object_oid(&base_oid, p, revidx->nr);
1745 error("failed to read delta base object %s"
1746 " at offset %"PRIuMAX" from %s",
1747 oid_to_hex(&base_oid), (uintmax_t)obj_offset,
1748 p->pack_name);
1749 mark_bad_packed_object(p, base_oid.hash);
1750 base = read_object(r, &base_oid, &type, &base_size);
1751 external_base = base;
1752 }
1753 }
1754 i = --delta_stack_nr;
1756 obj_offset = delta_stack[i].obj_offset;
1757 curpos = delta_stack[i].curpos;
1758 delta_size = delta_stack[i].size;
1759 if (!base)
1761 continue;
1762 delta_data = unpack_compressed_entry(p, &w_curs, curpos, delta_size);
1764 if (!delta_data) {
1766 error("failed to unpack compressed delta "
1767 "at offset %"PRIuMAX" from %s",
1768 (uintmax_t)curpos, p->pack_name);
1769 data = NULL;
1770 free(external_base);
1771 continue;
1772 }
1773 data = patch_delta(base, base_size,
1775 delta_data, delta_size,
1776 &size);
1777 /*
1779 * We could not apply the delta; warn the user, but keep going.
1780 * Our failure will be noticed either in the next iteration of
1781 * the loop, or if this is the final delta, in the caller when
1782 * we return NULL. Those code paths will take care of making
1783 * a more explicit warning and retrying with another copy of
1784 * the object.
1785 */
1786 if (!data)
1787 error("failed to apply delta");
1788 free(delta_data);
1790 free(external_base);
1791 }
1792 if (final_type)
1794 *final_type = type;
1795 if (final_size)
1796 *final_size = size;
1797out:
1799 unuse_pack(&w_curs);
1800 if (delta_stack != small_delta_stack)
1802 free(delta_stack);
1803 return data;
1805}
1806int bsearch_pack(const struct object_id *oid, const struct packed_git *p, uint32_t *result)
1808{
1809 const unsigned char *index_fanout = p->index_data;
1810 const unsigned char *index_lookup;
1811 const unsigned int hashsz = the_hash_algo->rawsz;
1812 int index_lookup_width;
1813 if (!index_fanout)
1815 BUG("bsearch_pack called without a valid pack-index");
1816 index_lookup = index_fanout + 4 * 256;
1818 if (p->index_version == 1) {
1819 index_lookup_width = hashsz + 4;
1820 index_lookup += 4;
1821 } else {
1822 index_lookup_width = hashsz;
1823 index_fanout += 8;
1824 index_lookup += 8;
1825 }
1826 return bsearch_hash(oid->hash, (const uint32_t*)index_fanout,
1828 index_lookup, index_lookup_width, result);
1829}
1830const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1832 uint32_t n)
1833{
1834 const unsigned char *index = p->index_data;
1835 const unsigned int hashsz = the_hash_algo->rawsz;
1836 if (!index) {
1837 if (open_pack_index(p))
1838 return NULL;
1839 index = p->index_data;
1840 }
1841 if (n >= p->num_objects)
1842 return NULL;
1843 index += 4 * 256;
1844 if (p->index_version == 1) {
1845 return index + (hashsz + 4) * n + 4;
1846 } else {
1847 index += 8;
1848 return index + hashsz * n;
1849 }
1850}
1851const struct object_id *nth_packed_object_oid(struct object_id *oid,
1853 struct packed_git *p,
1854 uint32_t n)
1855{
1856 const unsigned char *hash = nth_packed_object_sha1(p, n);
1857 if (!hash)
1858 return NULL;
1859 hashcpy(oid->hash, hash);
1860 return oid;
1861}
1862void check_pack_index_ptr(const struct packed_git *p, const void *vptr)
1864{
1865 const unsigned char *ptr = vptr;
1866 const unsigned char *start = p->index_data;
1867 const unsigned char *end = start + p->index_size;
1868 if (ptr < start)
1869 die(_("offset before start of pack index for %s (corrupt index?)"),
1870 p->pack_name);
1871 /* No need to check for underflow; .idx files must be at least 8 bytes */
1872 if (ptr >= end - 8)
1873 die(_("offset beyond end of pack index for %s (truncated index?)"),
1874 p->pack_name);
1875}
1876off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1878{
1879 const unsigned char *index = p->index_data;
1880 const unsigned int hashsz = the_hash_algo->rawsz;
1881 index += 4 * 256;
1882 if (p->index_version == 1) {
1883 return ntohl(*((uint32_t *)(index + (hashsz + 4) * n)));
1884 } else {
1885 uint32_t off;
1886 index += 8 + p->num_objects * (hashsz + 4);
1887 off = ntohl(*((uint32_t *)(index + 4 * n)));
1888 if (!(off & 0x80000000))
1889 return off;
1890 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1891 check_pack_index_ptr(p, index);
1892 return get_be64(index);
1893 }
1894}
1895off_t find_pack_entry_one(const unsigned char *sha1,
1897 struct packed_git *p)
1898{
1899 const unsigned char *index = p->index_data;
1900 struct object_id oid;
1901 uint32_t result;
1902 if (!index) {
1904 if (open_pack_index(p))
1905 return 0;
1906 }
1907 hashcpy(oid.hash, sha1);
1909 if (bsearch_pack(&oid, p, &result))
1910 return nth_packed_object_offset(p, result);
1911 return 0;
1912}
1913int is_pack_valid(struct packed_git *p)
1915{
1916 /* An already open pack is known to be valid. */
1917 if (p->pack_fd != -1)
1918 return 1;
1919 /* If the pack has one window completely covering the
1921 * file size, the pack is known to be valid even if
1922 * the descriptor is not currently open.
1923 */
1924 if (p->windows) {
1925 struct pack_window *w = p->windows;
1926 if (!w->offset && w->len == p->pack_size)
1928 return 1;
1929 }
1930 /* Force the pack to open to prove its valid. */
1932 return !open_packed_git(p);
1933}
1934struct packed_git *find_sha1_pack(const unsigned char *sha1,
1936 struct packed_git *packs)
1937{
1938 struct packed_git *p;
1939 for (p = packs; p; p = p->next) {
1941 if (find_pack_entry_one(sha1, p))
1942 return p;
1943 }
1944 return NULL;
1945}
1947static int fill_pack_entry(const struct object_id *oid,
1949 struct pack_entry *e,
1950 struct packed_git *p)
1951{
1952 off_t offset;
1953 if (p->num_bad_objects) {
1955 unsigned i;
1956 for (i = 0; i < p->num_bad_objects; i++)
1957 if (hasheq(oid->hash,
1958 p->bad_object_sha1 + the_hash_algo->rawsz * i))
1959 return 0;
1960 }
1961 offset = find_pack_entry_one(oid->hash, p);
1963 if (!offset)
1964 return 0;
1965 /*
1967 * We are about to tell the caller where they can locate the
1968 * requested object. We better make sure the packfile is
1969 * still here and can be accessed before supplying that
1970 * answer, as it may have been deleted since the index was
1971 * loaded!
1972 */
1973 if (!is_pack_valid(p))
1974 return 0;
1975 e->offset = offset;
1976 e->p = p;
1977 return 1;
1978}
1979int find_pack_entry(struct repository *r, const struct object_id *oid, struct pack_entry *e)
1981{
1982 struct list_head *pos;
1983 struct multi_pack_index *m;
1984 prepare_packed_git(r);
1986 if (!r->objects->packed_git && !r->objects->multi_pack_index)
1987 return 0;
1988 for (m = r->objects->multi_pack_index; m; m = m->next) {
1990 if (fill_midx_entry(oid, e, m))
1991 return 1;
1992 }
1993 list_for_each(pos, &r->objects->packed_git_mru) {
1995 struct packed_git *p = list_entry(pos, struct packed_git, mru);
1996 if (fill_pack_entry(oid, e, p)) {
1997 list_move(&p->mru, &r->objects->packed_git_mru);
1998 return 1;
1999 }
2000 }
2001 return 0;
2002}
2003int has_object_pack(const struct object_id *oid)
2005{
2006 struct pack_entry e;
2007 return find_pack_entry(the_repository, oid, &e);
2008}
2009int has_pack_index(const unsigned char *sha1)
2011{
2012 struct stat st;
2013 if (stat(sha1_pack_index_name(sha1), &st))
2014 return 0;
2015 return 1;
2016}
2017int for_each_object_in_pack(struct packed_git *p,
2019 each_packed_object_fn cb, void *data,
2020 enum for_each_object_flags flags)
2021{
2022 uint32_t i;
2023 int r = 0;
2024 if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2026 load_pack_revindex(p);
2027 for (i = 0; i < p->num_objects; i++) {
2029 uint32_t pos;
2030 struct object_id oid;
2031 if (flags & FOR_EACH_OBJECT_PACK_ORDER)
2033 pos = p->revindex[i].nr;
2034 else
2035 pos = i;
2036 if (!nth_packed_object_oid(&oid, p, pos))
2038 return error("unable to get sha1 of object %u in %s",
2039 pos, p->pack_name);
2040 r = cb(&oid, p, pos, data);
2042 if (r)
2043 break;
2044 }
2045 return r;
2046}
2047int for_each_packed_object(each_packed_object_fn cb, void *data,
2049 enum for_each_object_flags flags)
2050{
2051 struct packed_git *p;
2052 int r = 0;
2053 int pack_errors = 0;
2054 prepare_packed_git(the_repository);
2056 for (p = get_all_packs(the_repository); p; p = p->next) {
2057 if ((flags & FOR_EACH_OBJECT_LOCAL_ONLY) && !p->pack_local)
2058 continue;
2059 if ((flags & FOR_EACH_OBJECT_PROMISOR_ONLY) &&
2060 !p->pack_promisor)
2061 continue;
2062 if (open_pack_index(p)) {
2063 pack_errors = 1;
2064 continue;
2065 }
2066 r = for_each_object_in_pack(p, cb, data, flags);
2067 if (r)
2068 break;
2069 }
2070 return r ? r : pack_errors;
2071}
2072static int add_promisor_object(const struct object_id *oid,
2074 struct packed_git *pack,
2075 uint32_t pos,
2076 void *set_)
2077{
2078 struct oidset *set = set_;
2079 struct object *obj = parse_object(the_repository, oid);
2080 if (!obj)
2081 return 1;
2082 oidset_insert(set, oid);
2084 /*
2086 * If this is a tree, commit, or tag, the objects it refers
2087 * to are also promisor objects. (Blobs refer to no objects->)
2088 */
2089 if (obj->type == OBJ_TREE) {
2090 struct tree *tree = (struct tree *)obj;
2091 struct tree_desc desc;
2092 struct name_entry entry;
2093 if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
2094 /*
2095 * Error messages are given when packs are
2096 * verified, so do not print any here.
2097 */
2098 return 0;
2099 while (tree_entry_gently(&desc, &entry))
2100 oidset_insert(set, entry.oid);
2101 } else if (obj->type == OBJ_COMMIT) {
2102 struct commit *commit = (struct commit *) obj;
2103 struct commit_list *parents = commit->parents;
2104 oidset_insert(set, get_commit_tree_oid(commit));
2106 for (; parents; parents = parents->next)
2107 oidset_insert(set, &parents->item->object.oid);
2108 } else if (obj->type == OBJ_TAG) {
2109 struct tag *tag = (struct tag *) obj;
2110 oidset_insert(set, &tag->tagged->oid);
2111 }
2112 return 0;
2113}
2114int is_promisor_object(const struct object_id *oid)
2116{
2117 static struct oidset promisor_objects;
2118 static int promisor_objects_prepared;
2119 if (!promisor_objects_prepared) {
2121 if (repository_format_partial_clone) {
2122 for_each_packed_object(add_promisor_object,
2123 &promisor_objects,
2124 FOR_EACH_OBJECT_PROMISOR_ONLY);
2125 }
2126 promisor_objects_prepared = 1;
2127 }
2128 return oidset_contains(&promisor_objects, oid);
2129}