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1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "delta.h"
11 #include "pack.h"
12 #include "blob.h"
13 #include "commit.h"
14 #include "tag.h"
15 #include "tree.h"
16 #include "refs.h"
17 #include "pack-revindex.h"
18 #include "sha1-lookup.h"
20 #ifndef O_NOATIME
21 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
22 #define O_NOATIME 01000000
23 #else
24 #define O_NOATIME 0
25 #endif
26 #endif
28 #ifdef NO_C99_FORMAT
29 #define SZ_FMT "lu"
30 static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
31 #else
32 #define SZ_FMT "zu"
33 static size_t sz_fmt(size_t s) { return s; }
34 #endif
36 const unsigned char null_sha1[20];
38 int safe_create_leading_directories(char *path)
39 {
40 char *pos = path + offset_1st_component(path);
41 struct stat st;
43 while (pos) {
44 pos = strchr(pos, '/');
45 if (!pos)
46 break;
47 while (*++pos == '/')
48 ;
49 if (!*pos)
50 break;
51 *--pos = '\0';
52 if (!stat(path, &st)) {
53 /* path exists */
54 if (!S_ISDIR(st.st_mode)) {
55 *pos = '/';
56 return -3;
57 }
58 }
59 else if (mkdir(path, 0777)) {
60 *pos = '/';
61 return -1;
62 }
63 else if (adjust_shared_perm(path)) {
64 *pos = '/';
65 return -2;
66 }
67 *pos++ = '/';
68 }
69 return 0;
70 }
72 int safe_create_leading_directories_const(const char *path)
73 {
74 /* path points to cache entries, so xstrdup before messing with it */
75 char *buf = xstrdup(path);
76 int result = safe_create_leading_directories(buf);
77 free(buf);
78 return result;
79 }
81 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
82 {
83 int i;
84 for (i = 0; i < 20; i++) {
85 static char hex[] = "0123456789abcdef";
86 unsigned int val = sha1[i];
87 char *pos = pathbuf + i*2 + (i > 0);
88 *pos++ = hex[val >> 4];
89 *pos = hex[val & 0xf];
90 }
91 }
93 /*
94 * NOTE! This returns a statically allocated buffer, so you have to be
95 * careful about using it. Do an "xstrdup()" if you need to save the
96 * filename.
97 *
98 * Also note that this returns the location for creating. Reading
99 * SHA1 file can happen from any alternate directory listed in the
100 * DB_ENVIRONMENT environment variable if it is not found in
101 * the primary object database.
102 */
103 char *sha1_file_name(const unsigned char *sha1)
104 {
105 static char *name, *base;
107 if (!base) {
108 const char *sha1_file_directory = get_object_directory();
109 int len = strlen(sha1_file_directory);
110 base = xmalloc(len + 60);
111 memcpy(base, sha1_file_directory, len);
112 memset(base+len, 0, 60);
113 base[len] = '/';
114 base[len+3] = '/';
115 name = base + len + 1;
116 }
117 fill_sha1_path(name, sha1);
118 return base;
119 }
121 static char *sha1_get_pack_name(const unsigned char *sha1,
122 char **name, char **base, const char *which)
123 {
124 static const char hex[] = "0123456789abcdef";
125 char *buf;
126 int i;
128 if (!*base) {
129 const char *sha1_file_directory = get_object_directory();
130 int len = strlen(sha1_file_directory);
131 *base = xmalloc(len + 60);
132 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
133 sha1_file_directory, which);
134 *name = *base + len + 11;
135 }
137 buf = *name;
139 for (i = 0; i < 20; i++) {
140 unsigned int val = *sha1++;
141 *buf++ = hex[val >> 4];
142 *buf++ = hex[val & 0xf];
143 }
145 return *base;
146 }
148 char *sha1_pack_name(const unsigned char *sha1)
149 {
150 static char *name, *base;
152 return sha1_get_pack_name(sha1, &name, &base, "pack");
153 }
155 char *sha1_pack_index_name(const unsigned char *sha1)
156 {
157 static char *name, *base;
159 return sha1_get_pack_name(sha1, &name, &base, "idx");
160 }
162 struct alternate_object_database *alt_odb_list;
163 static struct alternate_object_database **alt_odb_tail;
165 static void read_info_alternates(const char * alternates, int depth);
167 /*
168 * Prepare alternate object database registry.
169 *
170 * The variable alt_odb_list points at the list of struct
171 * alternate_object_database. The elements on this list come from
172 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
173 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
174 * whose contents is similar to that environment variable but can be
175 * LF separated. Its base points at a statically allocated buffer that
176 * contains "/the/directory/corresponding/to/.git/objects/...", while
177 * its name points just after the slash at the end of ".git/objects/"
178 * in the example above, and has enough space to hold 40-byte hex
179 * SHA1, an extra slash for the first level indirection, and the
180 * terminating NUL.
181 */
182 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
183 {
184 const char *objdir = get_object_directory();
185 struct alternate_object_database *ent;
186 struct alternate_object_database *alt;
187 /* 43 = 40-byte + 2 '/' + terminating NUL */
188 int pfxlen = len;
189 int entlen = pfxlen + 43;
190 int base_len = -1;
192 if (!is_absolute_path(entry) && relative_base) {
193 /* Relative alt-odb */
194 if (base_len < 0)
195 base_len = strlen(relative_base) + 1;
196 entlen += base_len;
197 pfxlen += base_len;
198 }
199 ent = xmalloc(sizeof(*ent) + entlen);
201 if (!is_absolute_path(entry) && relative_base) {
202 memcpy(ent->base, relative_base, base_len - 1);
203 ent->base[base_len - 1] = '/';
204 memcpy(ent->base + base_len, entry, len);
205 }
206 else
207 memcpy(ent->base, entry, pfxlen);
209 ent->name = ent->base + pfxlen + 1;
210 ent->base[pfxlen + 3] = '/';
211 ent->base[pfxlen] = ent->base[entlen-1] = 0;
213 /* Detect cases where alternate disappeared */
214 if (!is_directory(ent->base)) {
215 error("object directory %s does not exist; "
216 "check .git/objects/info/alternates.",
217 ent->base);
218 free(ent);
219 return -1;
220 }
222 /* Prevent the common mistake of listing the same
223 * thing twice, or object directory itself.
224 */
225 for (alt = alt_odb_list; alt; alt = alt->next) {
226 if (!memcmp(ent->base, alt->base, pfxlen)) {
227 free(ent);
228 return -1;
229 }
230 }
231 if (!memcmp(ent->base, objdir, pfxlen)) {
232 free(ent);
233 return -1;
234 }
236 /* add the alternate entry */
237 *alt_odb_tail = ent;
238 alt_odb_tail = &(ent->next);
239 ent->next = NULL;
241 /* recursively add alternates */
242 read_info_alternates(ent->base, depth + 1);
244 ent->base[pfxlen] = '/';
246 return 0;
247 }
249 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
250 const char *relative_base, int depth)
251 {
252 const char *cp, *last;
254 if (depth > 5) {
255 error("%s: ignoring alternate object stores, nesting too deep.",
256 relative_base);
257 return;
258 }
260 last = alt;
261 while (last < ep) {
262 cp = last;
263 if (cp < ep && *cp == '#') {
264 while (cp < ep && *cp != sep)
265 cp++;
266 last = cp + 1;
267 continue;
268 }
269 while (cp < ep && *cp != sep)
270 cp++;
271 if (last != cp) {
272 if (!is_absolute_path(last) && depth) {
273 error("%s: ignoring relative alternate object store %s",
274 relative_base, last);
275 } else {
276 link_alt_odb_entry(last, cp - last,
277 relative_base, depth);
278 }
279 }
280 while (cp < ep && *cp == sep)
281 cp++;
282 last = cp;
283 }
284 }
286 static void read_info_alternates(const char * relative_base, int depth)
287 {
288 char *map;
289 size_t mapsz;
290 struct stat st;
291 const char alt_file_name[] = "info/alternates";
292 /* Given that relative_base is no longer than PATH_MAX,
293 ensure that "path" has enough space to append "/", the
294 file name, "info/alternates", and a trailing NUL. */
295 char path[PATH_MAX + 1 + sizeof alt_file_name];
296 int fd;
298 sprintf(path, "%s/%s", relative_base, alt_file_name);
299 fd = open(path, O_RDONLY);
300 if (fd < 0)
301 return;
302 if (fstat(fd, &st) || (st.st_size == 0)) {
303 close(fd);
304 return;
305 }
306 mapsz = xsize_t(st.st_size);
307 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
308 close(fd);
310 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
312 munmap(map, mapsz);
313 }
315 void add_to_alternates_file(const char *reference)
316 {
317 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
318 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
319 char *alt = mkpath("%s/objects\n", reference);
320 write_or_die(fd, alt, strlen(alt));
321 if (commit_lock_file(lock))
322 die("could not close alternates file");
323 if (alt_odb_tail)
324 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
325 }
327 void foreach_alt_odb(alt_odb_fn fn, void *cb)
328 {
329 struct alternate_object_database *ent;
331 prepare_alt_odb();
332 for (ent = alt_odb_list; ent; ent = ent->next)
333 if (fn(ent, cb))
334 return;
335 }
337 void prepare_alt_odb(void)
338 {
339 const char *alt;
341 if (alt_odb_tail)
342 return;
344 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
345 if (!alt) alt = "";
347 alt_odb_tail = &alt_odb_list;
348 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
350 read_info_alternates(get_object_directory(), 0);
351 }
353 static int has_loose_object_local(const unsigned char *sha1)
354 {
355 char *name = sha1_file_name(sha1);
356 return !access(name, F_OK);
357 }
359 int has_loose_object_nonlocal(const unsigned char *sha1)
360 {
361 struct alternate_object_database *alt;
362 prepare_alt_odb();
363 for (alt = alt_odb_list; alt; alt = alt->next) {
364 fill_sha1_path(alt->name, sha1);
365 if (!access(alt->base, F_OK))
366 return 1;
367 }
368 return 0;
369 }
371 static int has_loose_object(const unsigned char *sha1)
372 {
373 return has_loose_object_local(sha1) ||
374 has_loose_object_nonlocal(sha1);
375 }
377 static unsigned int pack_used_ctr;
378 static unsigned int pack_mmap_calls;
379 static unsigned int peak_pack_open_windows;
380 static unsigned int pack_open_windows;
381 static size_t peak_pack_mapped;
382 static size_t pack_mapped;
383 struct packed_git *packed_git;
385 void pack_report(void)
386 {
387 fprintf(stderr,
388 "pack_report: getpagesize() = %10" SZ_FMT "\n"
389 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
390 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
391 sz_fmt(getpagesize()),
392 sz_fmt(packed_git_window_size),
393 sz_fmt(packed_git_limit));
394 fprintf(stderr,
395 "pack_report: pack_used_ctr = %10u\n"
396 "pack_report: pack_mmap_calls = %10u\n"
397 "pack_report: pack_open_windows = %10u / %10u\n"
398 "pack_report: pack_mapped = "
399 "%10" SZ_FMT " / %10" SZ_FMT "\n",
400 pack_used_ctr,
401 pack_mmap_calls,
402 pack_open_windows, peak_pack_open_windows,
403 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
404 }
406 static int check_packed_git_idx(const char *path, struct packed_git *p)
407 {
408 void *idx_map;
409 struct pack_idx_header *hdr;
410 size_t idx_size;
411 uint32_t version, nr, i, *index;
412 int fd = open(path, O_RDONLY);
413 struct stat st;
415 if (fd < 0)
416 return -1;
417 if (fstat(fd, &st)) {
418 close(fd);
419 return -1;
420 }
421 idx_size = xsize_t(st.st_size);
422 if (idx_size < 4 * 256 + 20 + 20) {
423 close(fd);
424 return error("index file %s is too small", path);
425 }
426 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
427 close(fd);
429 hdr = idx_map;
430 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
431 version = ntohl(hdr->idx_version);
432 if (version < 2 || version > 2) {
433 munmap(idx_map, idx_size);
434 return error("index file %s is version %"PRIu32
435 " and is not supported by this binary"
436 " (try upgrading GIT to a newer version)",
437 path, version);
438 }
439 } else
440 version = 1;
442 nr = 0;
443 index = idx_map;
444 if (version > 1)
445 index += 2; /* skip index header */
446 for (i = 0; i < 256; i++) {
447 uint32_t n = ntohl(index[i]);
448 if (n < nr) {
449 munmap(idx_map, idx_size);
450 return error("non-monotonic index %s", path);
451 }
452 nr = n;
453 }
455 if (version == 1) {
456 /*
457 * Total size:
458 * - 256 index entries 4 bytes each
459 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
460 * - 20-byte SHA1 of the packfile
461 * - 20-byte SHA1 file checksum
462 */
463 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
464 munmap(idx_map, idx_size);
465 return error("wrong index v1 file size in %s", path);
466 }
467 } else if (version == 2) {
468 /*
469 * Minimum size:
470 * - 8 bytes of header
471 * - 256 index entries 4 bytes each
472 * - 20-byte sha1 entry * nr
473 * - 4-byte crc entry * nr
474 * - 4-byte offset entry * nr
475 * - 20-byte SHA1 of the packfile
476 * - 20-byte SHA1 file checksum
477 * And after the 4-byte offset table might be a
478 * variable sized table containing 8-byte entries
479 * for offsets larger than 2^31.
480 */
481 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
482 unsigned long max_size = min_size;
483 if (nr)
484 max_size += (nr - 1)*8;
485 if (idx_size < min_size || idx_size > max_size) {
486 munmap(idx_map, idx_size);
487 return error("wrong index v2 file size in %s", path);
488 }
489 if (idx_size != min_size &&
490 /*
491 * make sure we can deal with large pack offsets.
492 * 31-bit signed offset won't be enough, neither
493 * 32-bit unsigned one will be.
494 */
495 (sizeof(off_t) <= 4)) {
496 munmap(idx_map, idx_size);
497 return error("pack too large for current definition of off_t in %s", path);
498 }
499 }
501 p->index_version = version;
502 p->index_data = idx_map;
503 p->index_size = idx_size;
504 p->num_objects = nr;
505 return 0;
506 }
508 int open_pack_index(struct packed_git *p)
509 {
510 char *idx_name;
511 int ret;
513 if (p->index_data)
514 return 0;
516 idx_name = xstrdup(p->pack_name);
517 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
518 ret = check_packed_git_idx(idx_name, p);
519 free(idx_name);
520 return ret;
521 }
523 static void scan_windows(struct packed_git *p,
524 struct packed_git **lru_p,
525 struct pack_window **lru_w,
526 struct pack_window **lru_l)
527 {
528 struct pack_window *w, *w_l;
530 for (w_l = NULL, w = p->windows; w; w = w->next) {
531 if (!w->inuse_cnt) {
532 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
533 *lru_p = p;
534 *lru_w = w;
535 *lru_l = w_l;
536 }
537 }
538 w_l = w;
539 }
540 }
542 static int unuse_one_window(struct packed_git *current, int keep_fd)
543 {
544 struct packed_git *p, *lru_p = NULL;
545 struct pack_window *lru_w = NULL, *lru_l = NULL;
547 if (current)
548 scan_windows(current, &lru_p, &lru_w, &lru_l);
549 for (p = packed_git; p; p = p->next)
550 scan_windows(p, &lru_p, &lru_w, &lru_l);
551 if (lru_p) {
552 munmap(lru_w->base, lru_w->len);
553 pack_mapped -= lru_w->len;
554 if (lru_l)
555 lru_l->next = lru_w->next;
556 else {
557 lru_p->windows = lru_w->next;
558 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
559 close(lru_p->pack_fd);
560 lru_p->pack_fd = -1;
561 }
562 }
563 free(lru_w);
564 pack_open_windows--;
565 return 1;
566 }
567 return 0;
568 }
570 void release_pack_memory(size_t need, int fd)
571 {
572 size_t cur = pack_mapped;
573 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
574 ; /* nothing */
575 }
577 void close_pack_windows(struct packed_git *p)
578 {
579 while (p->windows) {
580 struct pack_window *w = p->windows;
582 if (w->inuse_cnt)
583 die("pack '%s' still has open windows to it",
584 p->pack_name);
585 munmap(w->base, w->len);
586 pack_mapped -= w->len;
587 pack_open_windows--;
588 p->windows = w->next;
589 free(w);
590 }
591 }
593 void unuse_pack(struct pack_window **w_cursor)
594 {
595 struct pack_window *w = *w_cursor;
596 if (w) {
597 w->inuse_cnt--;
598 *w_cursor = NULL;
599 }
600 }
602 void close_pack_index(struct packed_git *p)
603 {
604 if (p->index_data) {
605 munmap((void *)p->index_data, p->index_size);
606 p->index_data = NULL;
607 }
608 }
610 /*
611 * This is used by git-repack in case a newly created pack happens to
612 * contain the same set of objects as an existing one. In that case
613 * the resulting file might be different even if its name would be the
614 * same. It is best to close any reference to the old pack before it is
615 * replaced on disk. Of course no index pointers nor windows for given pack
616 * must subsist at this point. If ever objects from this pack are requested
617 * again, the new version of the pack will be reinitialized through
618 * reprepare_packed_git().
619 */
620 void free_pack_by_name(const char *pack_name)
621 {
622 struct packed_git *p, **pp = &packed_git;
624 while (*pp) {
625 p = *pp;
626 if (strcmp(pack_name, p->pack_name) == 0) {
627 clear_delta_base_cache();
628 close_pack_windows(p);
629 if (p->pack_fd != -1)
630 close(p->pack_fd);
631 close_pack_index(p);
632 free(p->bad_object_sha1);
633 *pp = p->next;
634 free(p);
635 return;
636 }
637 pp = &p->next;
638 }
639 }
641 /*
642 * Do not call this directly as this leaks p->pack_fd on error return;
643 * call open_packed_git() instead.
644 */
645 static int open_packed_git_1(struct packed_git *p)
646 {
647 struct stat st;
648 struct pack_header hdr;
649 unsigned char sha1[20];
650 unsigned char *idx_sha1;
651 long fd_flag;
653 if (!p->index_data && open_pack_index(p))
654 return error("packfile %s index unavailable", p->pack_name);
656 p->pack_fd = open(p->pack_name, O_RDONLY);
657 while (p->pack_fd < 0 && errno == EMFILE && unuse_one_window(p, -1))
658 p->pack_fd = open(p->pack_name, O_RDONLY);
659 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
660 return -1;
662 /* If we created the struct before we had the pack we lack size. */
663 if (!p->pack_size) {
664 if (!S_ISREG(st.st_mode))
665 return error("packfile %s not a regular file", p->pack_name);
666 p->pack_size = st.st_size;
667 } else if (p->pack_size != st.st_size)
668 return error("packfile %s size changed", p->pack_name);
670 /* We leave these file descriptors open with sliding mmap;
671 * there is no point keeping them open across exec(), though.
672 */
673 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
674 if (fd_flag < 0)
675 return error("cannot determine file descriptor flags");
676 fd_flag |= FD_CLOEXEC;
677 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
678 return error("cannot set FD_CLOEXEC");
680 /* Verify we recognize this pack file format. */
681 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
682 return error("file %s is far too short to be a packfile", p->pack_name);
683 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
684 return error("file %s is not a GIT packfile", p->pack_name);
685 if (!pack_version_ok(hdr.hdr_version))
686 return error("packfile %s is version %"PRIu32" and not"
687 " supported (try upgrading GIT to a newer version)",
688 p->pack_name, ntohl(hdr.hdr_version));
690 /* Verify the pack matches its index. */
691 if (p->num_objects != ntohl(hdr.hdr_entries))
692 return error("packfile %s claims to have %"PRIu32" objects"
693 " while index indicates %"PRIu32" objects",
694 p->pack_name, ntohl(hdr.hdr_entries),
695 p->num_objects);
696 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
697 return error("end of packfile %s is unavailable", p->pack_name);
698 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
699 return error("packfile %s signature is unavailable", p->pack_name);
700 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
701 if (hashcmp(sha1, idx_sha1))
702 return error("packfile %s does not match index", p->pack_name);
703 return 0;
704 }
706 static int open_packed_git(struct packed_git *p)
707 {
708 if (!open_packed_git_1(p))
709 return 0;
710 if (p->pack_fd != -1) {
711 close(p->pack_fd);
712 p->pack_fd = -1;
713 }
714 return -1;
715 }
717 static int in_window(struct pack_window *win, off_t offset)
718 {
719 /* We must promise at least 20 bytes (one hash) after the
720 * offset is available from this window, otherwise the offset
721 * is not actually in this window and a different window (which
722 * has that one hash excess) must be used. This is to support
723 * the object header and delta base parsing routines below.
724 */
725 off_t win_off = win->offset;
726 return win_off <= offset
727 && (offset + 20) <= (win_off + win->len);
728 }
730 unsigned char *use_pack(struct packed_git *p,
731 struct pack_window **w_cursor,
732 off_t offset,
733 unsigned int *left)
734 {
735 struct pack_window *win = *w_cursor;
737 if (p->pack_fd == -1 && open_packed_git(p))
738 die("packfile %s cannot be accessed", p->pack_name);
740 /* Since packfiles end in a hash of their content and it's
741 * pointless to ask for an offset into the middle of that
742 * hash, and the in_window function above wouldn't match
743 * don't allow an offset too close to the end of the file.
744 */
745 if (offset > (p->pack_size - 20))
746 die("offset beyond end of packfile (truncated pack?)");
748 if (!win || !in_window(win, offset)) {
749 if (win)
750 win->inuse_cnt--;
751 for (win = p->windows; win; win = win->next) {
752 if (in_window(win, offset))
753 break;
754 }
755 if (!win) {
756 size_t window_align = packed_git_window_size / 2;
757 off_t len;
758 win = xcalloc(1, sizeof(*win));
759 win->offset = (offset / window_align) * window_align;
760 len = p->pack_size - win->offset;
761 if (len > packed_git_window_size)
762 len = packed_git_window_size;
763 win->len = (size_t)len;
764 pack_mapped += win->len;
765 while (packed_git_limit < pack_mapped
766 && unuse_one_window(p, p->pack_fd))
767 ; /* nothing */
768 win->base = xmmap(NULL, win->len,
769 PROT_READ, MAP_PRIVATE,
770 p->pack_fd, win->offset);
771 if (win->base == MAP_FAILED)
772 die("packfile %s cannot be mapped: %s",
773 p->pack_name,
774 strerror(errno));
775 pack_mmap_calls++;
776 pack_open_windows++;
777 if (pack_mapped > peak_pack_mapped)
778 peak_pack_mapped = pack_mapped;
779 if (pack_open_windows > peak_pack_open_windows)
780 peak_pack_open_windows = pack_open_windows;
781 win->next = p->windows;
782 p->windows = win;
783 }
784 }
785 if (win != *w_cursor) {
786 win->last_used = pack_used_ctr++;
787 win->inuse_cnt++;
788 *w_cursor = win;
789 }
790 offset -= win->offset;
791 if (left)
792 *left = win->len - xsize_t(offset);
793 return win->base + offset;
794 }
796 static struct packed_git *alloc_packed_git(int extra)
797 {
798 struct packed_git *p = xmalloc(sizeof(*p) + extra);
799 memset(p, 0, sizeof(*p));
800 p->pack_fd = -1;
801 return p;
802 }
804 struct packed_git *add_packed_git(const char *path, int path_len, int local)
805 {
806 struct stat st;
807 struct packed_git *p = alloc_packed_git(path_len + 2);
809 /*
810 * Make sure a corresponding .pack file exists and that
811 * the index looks sane.
812 */
813 path_len -= strlen(".idx");
814 if (path_len < 1) {
815 free(p);
816 return NULL;
817 }
818 memcpy(p->pack_name, path, path_len);
820 strcpy(p->pack_name + path_len, ".keep");
821 if (!access(p->pack_name, F_OK))
822 p->pack_keep = 1;
824 strcpy(p->pack_name + path_len, ".pack");
825 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
826 free(p);
827 return NULL;
828 }
830 /* ok, it looks sane as far as we can check without
831 * actually mapping the pack file.
832 */
833 p->pack_size = st.st_size;
834 p->pack_local = local;
835 p->mtime = st.st_mtime;
836 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
837 hashclr(p->sha1);
838 return p;
839 }
841 struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
842 {
843 const char *path = sha1_pack_name(sha1);
844 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
846 strcpy(p->pack_name, path);
847 hashcpy(p->sha1, sha1);
848 if (check_packed_git_idx(idx_path, p)) {
849 free(p);
850 return NULL;
851 }
853 return p;
854 }
856 void install_packed_git(struct packed_git *pack)
857 {
858 pack->next = packed_git;
859 packed_git = pack;
860 }
862 static void prepare_packed_git_one(char *objdir, int local)
863 {
864 /* Ensure that this buffer is large enough so that we can
865 append "/pack/" without clobbering the stack even if
866 strlen(objdir) were PATH_MAX. */
867 char path[PATH_MAX + 1 + 4 + 1 + 1];
868 int len;
869 DIR *dir;
870 struct dirent *de;
872 sprintf(path, "%s/pack", objdir);
873 len = strlen(path);
874 dir = opendir(path);
875 while (!dir && errno == EMFILE && unuse_one_window(packed_git, -1))
876 dir = opendir(path);
877 if (!dir) {
878 if (errno != ENOENT)
879 error("unable to open object pack directory: %s: %s",
880 path, strerror(errno));
881 return;
882 }
883 path[len++] = '/';
884 while ((de = readdir(dir)) != NULL) {
885 int namelen = strlen(de->d_name);
886 struct packed_git *p;
888 if (!has_extension(de->d_name, ".idx"))
889 continue;
891 if (len + namelen + 1 > sizeof(path))
892 continue;
894 /* Don't reopen a pack we already have. */
895 strcpy(path + len, de->d_name);
896 for (p = packed_git; p; p = p->next) {
897 if (!memcmp(path, p->pack_name, len + namelen - 4))
898 break;
899 }
900 if (p)
901 continue;
902 /* See if it really is a valid .idx file with corresponding
903 * .pack file that we can map.
904 */
905 p = add_packed_git(path, len + namelen, local);
906 if (!p)
907 continue;
908 install_packed_git(p);
909 }
910 closedir(dir);
911 }
913 static int sort_pack(const void *a_, const void *b_)
914 {
915 struct packed_git *a = *((struct packed_git **)a_);
916 struct packed_git *b = *((struct packed_git **)b_);
917 int st;
919 /*
920 * Local packs tend to contain objects specific to our
921 * variant of the project than remote ones. In addition,
922 * remote ones could be on a network mounted filesystem.
923 * Favor local ones for these reasons.
924 */
925 st = a->pack_local - b->pack_local;
926 if (st)
927 return -st;
929 /*
930 * Younger packs tend to contain more recent objects,
931 * and more recent objects tend to get accessed more
932 * often.
933 */
934 if (a->mtime < b->mtime)
935 return 1;
936 else if (a->mtime == b->mtime)
937 return 0;
938 return -1;
939 }
941 static void rearrange_packed_git(void)
942 {
943 struct packed_git **ary, *p;
944 int i, n;
946 for (n = 0, p = packed_git; p; p = p->next)
947 n++;
948 if (n < 2)
949 return;
951 /* prepare an array of packed_git for easier sorting */
952 ary = xcalloc(n, sizeof(struct packed_git *));
953 for (n = 0, p = packed_git; p; p = p->next)
954 ary[n++] = p;
956 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
958 /* link them back again */
959 for (i = 0; i < n - 1; i++)
960 ary[i]->next = ary[i + 1];
961 ary[n - 1]->next = NULL;
962 packed_git = ary[0];
964 free(ary);
965 }
967 static int prepare_packed_git_run_once = 0;
968 void prepare_packed_git(void)
969 {
970 struct alternate_object_database *alt;
972 if (prepare_packed_git_run_once)
973 return;
974 prepare_packed_git_one(get_object_directory(), 1);
975 prepare_alt_odb();
976 for (alt = alt_odb_list; alt; alt = alt->next) {
977 alt->name[-1] = 0;
978 prepare_packed_git_one(alt->base, 0);
979 alt->name[-1] = '/';
980 }
981 rearrange_packed_git();
982 prepare_packed_git_run_once = 1;
983 }
985 void reprepare_packed_git(void)
986 {
987 discard_revindex();
988 prepare_packed_git_run_once = 0;
989 prepare_packed_git();
990 }
992 static void mark_bad_packed_object(struct packed_git *p,
993 const unsigned char *sha1)
994 {
995 unsigned i;
996 for (i = 0; i < p->num_bad_objects; i++)
997 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
998 return;
999 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1000 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1001 p->num_bad_objects++;
1002 }
1004 static int has_packed_and_bad(const unsigned char *sha1)
1005 {
1006 struct packed_git *p;
1007 unsigned i;
1009 for (p = packed_git; p; p = p->next)
1010 for (i = 0; i < p->num_bad_objects; i++)
1011 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1012 return 1;
1013 return 0;
1014 }
1016 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
1017 {
1018 unsigned char real_sha1[20];
1019 hash_sha1_file(map, size, type, real_sha1);
1020 return hashcmp(sha1, real_sha1) ? -1 : 0;
1021 }
1023 static int git_open_noatime(const char *name)
1024 {
1025 static int sha1_file_open_flag = O_NOATIME;
1026 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1028 /* Might the failure be due to O_NOATIME? */
1029 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1030 fd = open(name, O_RDONLY);
1031 if (fd >= 0)
1032 sha1_file_open_flag = 0;
1033 }
1034 return fd;
1035 }
1037 static int open_sha1_file(const unsigned char *sha1)
1038 {
1039 int fd;
1040 char *name = sha1_file_name(sha1);
1041 struct alternate_object_database *alt;
1043 fd = git_open_noatime(name);
1044 if (fd >= 0)
1045 return fd;
1047 prepare_alt_odb();
1048 errno = ENOENT;
1049 for (alt = alt_odb_list; alt; alt = alt->next) {
1050 name = alt->name;
1051 fill_sha1_path(name, sha1);
1052 fd = git_open_noatime(alt->base);
1053 if (fd >= 0)
1054 return fd;
1055 }
1056 return -1;
1057 }
1059 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1060 {
1061 void *map;
1062 int fd;
1064 fd = open_sha1_file(sha1);
1065 map = NULL;
1066 if (fd >= 0) {
1067 struct stat st;
1069 if (!fstat(fd, &st)) {
1070 *size = xsize_t(st.st_size);
1071 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1072 }
1073 close(fd);
1074 }
1075 return map;
1076 }
1078 static int legacy_loose_object(unsigned char *map)
1079 {
1080 unsigned int word;
1082 /*
1083 * Is it a zlib-compressed buffer? If so, the first byte
1084 * must be 0x78 (15-bit window size, deflated), and the
1085 * first 16-bit word is evenly divisible by 31
1086 */
1087 word = (map[0] << 8) + map[1];
1088 if (map[0] == 0x78 && !(word % 31))
1089 return 1;
1090 else
1091 return 0;
1092 }
1094 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1095 unsigned long len, enum object_type *type, unsigned long *sizep)
1096 {
1097 unsigned shift;
1098 unsigned long size, c;
1099 unsigned long used = 0;
1101 c = buf[used++];
1102 *type = (c >> 4) & 7;
1103 size = c & 15;
1104 shift = 4;
1105 while (c & 0x80) {
1106 if (len <= used || bitsizeof(long) <= shift) {
1107 error("bad object header");
1108 return 0;
1109 }
1110 c = buf[used++];
1111 size += (c & 0x7f) << shift;
1112 shift += 7;
1113 }
1114 *sizep = size;
1115 return used;
1116 }
1118 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1119 {
1120 unsigned long size, used;
1121 static const char valid_loose_object_type[8] = {
1122 0, /* OBJ_EXT */
1123 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1124 0, /* "delta" and others are invalid in a loose object */
1125 };
1126 enum object_type type;
1128 /* Get the data stream */
1129 memset(stream, 0, sizeof(*stream));
1130 stream->next_in = map;
1131 stream->avail_in = mapsize;
1132 stream->next_out = buffer;
1133 stream->avail_out = bufsiz;
1135 if (legacy_loose_object(map)) {
1136 git_inflate_init(stream);
1137 return git_inflate(stream, 0);
1138 }
1141 /*
1142 * There used to be a second loose object header format which
1143 * was meant to mimic the in-pack format, allowing for direct
1144 * copy of the object data. This format turned up not to be
1145 * really worth it and we don't write it any longer. But we
1146 * can still read it.
1147 */
1148 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1149 if (!used || !valid_loose_object_type[type])
1150 return -1;
1151 map += used;
1152 mapsize -= used;
1154 /* Set up the stream for the rest.. */
1155 stream->next_in = map;
1156 stream->avail_in = mapsize;
1157 git_inflate_init(stream);
1159 /* And generate the fake traditional header */
1160 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1161 typename(type), size);
1162 return 0;
1163 }
1165 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1166 {
1167 int bytes = strlen(buffer) + 1;
1168 unsigned char *buf = xmallocz(size);
1169 unsigned long n;
1170 int status = Z_OK;
1172 n = stream->total_out - bytes;
1173 if (n > size)
1174 n = size;
1175 memcpy(buf, (char *) buffer + bytes, n);
1176 bytes = n;
1177 if (bytes <= size) {
1178 /*
1179 * The above condition must be (bytes <= size), not
1180 * (bytes < size). In other words, even though we
1181 * expect no more output and set avail_out to zer0,
1182 * the input zlib stream may have bytes that express
1183 * "this concludes the stream", and we *do* want to
1184 * eat that input.
1185 *
1186 * Otherwise we would not be able to test that we
1187 * consumed all the input to reach the expected size;
1188 * we also want to check that zlib tells us that all
1189 * went well with status == Z_STREAM_END at the end.
1190 */
1191 stream->next_out = buf + bytes;
1192 stream->avail_out = size - bytes;
1193 while (status == Z_OK)
1194 status = git_inflate(stream, Z_FINISH);
1195 }
1196 if (status == Z_STREAM_END && !stream->avail_in) {
1197 git_inflate_end(stream);
1198 return buf;
1199 }
1201 if (status < 0)
1202 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1203 else if (stream->avail_in)
1204 error("garbage at end of loose object '%s'",
1205 sha1_to_hex(sha1));
1206 free(buf);
1207 return NULL;
1208 }
1210 /*
1211 * We used to just use "sscanf()", but that's actually way
1212 * too permissive for what we want to check. So do an anal
1213 * object header parse by hand.
1214 */
1215 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1216 {
1217 char type[10];
1218 int i;
1219 unsigned long size;
1221 /*
1222 * The type can be at most ten bytes (including the
1223 * terminating '\0' that we add), and is followed by
1224 * a space.
1225 */
1226 i = 0;
1227 for (;;) {
1228 char c = *hdr++;
1229 if (c == ' ')
1230 break;
1231 type[i++] = c;
1232 if (i >= sizeof(type))
1233 return -1;
1234 }
1235 type[i] = 0;
1237 /*
1238 * The length must follow immediately, and be in canonical
1239 * decimal format (ie "010" is not valid).
1240 */
1241 size = *hdr++ - '0';
1242 if (size > 9)
1243 return -1;
1244 if (size) {
1245 for (;;) {
1246 unsigned long c = *hdr - '0';
1247 if (c > 9)
1248 break;
1249 hdr++;
1250 size = size * 10 + c;
1251 }
1252 }
1253 *sizep = size;
1255 /*
1256 * The length must be followed by a zero byte
1257 */
1258 return *hdr ? -1 : type_from_string(type);
1259 }
1261 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1262 {
1263 int ret;
1264 z_stream stream;
1265 char hdr[8192];
1267 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1268 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1269 return NULL;
1271 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1272 }
1274 unsigned long get_size_from_delta(struct packed_git *p,
1275 struct pack_window **w_curs,
1276 off_t curpos)
1277 {
1278 const unsigned char *data;
1279 unsigned char delta_head[20], *in;
1280 z_stream stream;
1281 int st;
1283 memset(&stream, 0, sizeof(stream));
1284 stream.next_out = delta_head;
1285 stream.avail_out = sizeof(delta_head);
1287 git_inflate_init(&stream);
1288 do {
1289 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1290 stream.next_in = in;
1291 st = git_inflate(&stream, Z_FINISH);
1292 curpos += stream.next_in - in;
1293 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1294 stream.total_out < sizeof(delta_head));
1295 git_inflate_end(&stream);
1296 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1297 error("delta data unpack-initial failed");
1298 return 0;
1299 }
1301 /* Examine the initial part of the delta to figure out
1302 * the result size.
1303 */
1304 data = delta_head;
1306 /* ignore base size */
1307 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1309 /* Read the result size */
1310 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1311 }
1313 static off_t get_delta_base(struct packed_git *p,
1314 struct pack_window **w_curs,
1315 off_t *curpos,
1316 enum object_type type,
1317 off_t delta_obj_offset)
1318 {
1319 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1320 off_t base_offset;
1322 /* use_pack() assured us we have [base_info, base_info + 20)
1323 * as a range that we can look at without walking off the
1324 * end of the mapped window. Its actually the hash size
1325 * that is assured. An OFS_DELTA longer than the hash size
1326 * is stupid, as then a REF_DELTA would be smaller to store.
1327 */
1328 if (type == OBJ_OFS_DELTA) {
1329 unsigned used = 0;
1330 unsigned char c = base_info[used++];
1331 base_offset = c & 127;
1332 while (c & 128) {
1333 base_offset += 1;
1334 if (!base_offset || MSB(base_offset, 7))
1335 return 0; /* overflow */
1336 c = base_info[used++];
1337 base_offset = (base_offset << 7) + (c & 127);
1338 }
1339 base_offset = delta_obj_offset - base_offset;
1340 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1341 return 0; /* out of bound */
1342 *curpos += used;
1343 } else if (type == OBJ_REF_DELTA) {
1344 /* The base entry _must_ be in the same pack */
1345 base_offset = find_pack_entry_one(base_info, p);
1346 *curpos += 20;
1347 } else
1348 die("I am totally screwed");
1349 return base_offset;
1350 }
1352 /* forward declaration for a mutually recursive function */
1353 static int packed_object_info(struct packed_git *p, off_t offset,
1354 unsigned long *sizep);
1356 static int packed_delta_info(struct packed_git *p,
1357 struct pack_window **w_curs,
1358 off_t curpos,
1359 enum object_type type,
1360 off_t obj_offset,
1361 unsigned long *sizep)
1362 {
1363 off_t base_offset;
1365 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1366 if (!base_offset)
1367 return OBJ_BAD;
1368 type = packed_object_info(p, base_offset, NULL);
1369 if (type <= OBJ_NONE) {
1370 struct revindex_entry *revidx;
1371 const unsigned char *base_sha1;
1372 revidx = find_pack_revindex(p, base_offset);
1373 if (!revidx)
1374 return OBJ_BAD;
1375 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1376 mark_bad_packed_object(p, base_sha1);
1377 type = sha1_object_info(base_sha1, NULL);
1378 if (type <= OBJ_NONE)
1379 return OBJ_BAD;
1380 }
1382 /* We choose to only get the type of the base object and
1383 * ignore potentially corrupt pack file that expects the delta
1384 * based on a base with a wrong size. This saves tons of
1385 * inflate() calls.
1386 */
1387 if (sizep) {
1388 *sizep = get_size_from_delta(p, w_curs, curpos);
1389 if (*sizep == 0)
1390 type = OBJ_BAD;
1391 }
1393 return type;
1394 }
1396 static int unpack_object_header(struct packed_git *p,
1397 struct pack_window **w_curs,
1398 off_t *curpos,
1399 unsigned long *sizep)
1400 {
1401 unsigned char *base;
1402 unsigned int left;
1403 unsigned long used;
1404 enum object_type type;
1406 /* use_pack() assures us we have [base, base + 20) available
1407 * as a range that we can look at at. (Its actually the hash
1408 * size that is assured.) With our object header encoding
1409 * the maximum deflated object size is 2^137, which is just
1410 * insane, so we know won't exceed what we have been given.
1411 */
1412 base = use_pack(p, w_curs, *curpos, &left);
1413 used = unpack_object_header_buffer(base, left, &type, sizep);
1414 if (!used) {
1415 type = OBJ_BAD;
1416 } else
1417 *curpos += used;
1419 return type;
1420 }
1422 const char *packed_object_info_detail(struct packed_git *p,
1423 off_t obj_offset,
1424 unsigned long *size,
1425 unsigned long *store_size,
1426 unsigned int *delta_chain_length,
1427 unsigned char *base_sha1)
1428 {
1429 struct pack_window *w_curs = NULL;
1430 off_t curpos;
1431 unsigned long dummy;
1432 unsigned char *next_sha1;
1433 enum object_type type;
1434 struct revindex_entry *revidx;
1436 *delta_chain_length = 0;
1437 curpos = obj_offset;
1438 type = unpack_object_header(p, &w_curs, &curpos, size);
1440 revidx = find_pack_revindex(p, obj_offset);
1441 *store_size = revidx[1].offset - obj_offset;
1443 for (;;) {
1444 switch (type) {
1445 default:
1446 die("pack %s contains unknown object type %d",
1447 p->pack_name, type);
1448 case OBJ_COMMIT:
1449 case OBJ_TREE:
1450 case OBJ_BLOB:
1451 case OBJ_TAG:
1452 unuse_pack(&w_curs);
1453 return typename(type);
1454 case OBJ_OFS_DELTA:
1455 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1456 if (!obj_offset)
1457 die("pack %s contains bad delta base reference of type %s",
1458 p->pack_name, typename(type));
1459 if (*delta_chain_length == 0) {
1460 revidx = find_pack_revindex(p, obj_offset);
1461 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
1462 }
1463 break;
1464 case OBJ_REF_DELTA:
1465 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1466 if (*delta_chain_length == 0)
1467 hashcpy(base_sha1, next_sha1);
1468 obj_offset = find_pack_entry_one(next_sha1, p);
1469 break;
1470 }
1471 (*delta_chain_length)++;
1472 curpos = obj_offset;
1473 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1474 }
1475 }
1477 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1478 unsigned long *sizep)
1479 {
1480 struct pack_window *w_curs = NULL;
1481 unsigned long size;
1482 off_t curpos = obj_offset;
1483 enum object_type type;
1485 type = unpack_object_header(p, &w_curs, &curpos, &size);
1487 switch (type) {
1488 case OBJ_OFS_DELTA:
1489 case OBJ_REF_DELTA:
1490 type = packed_delta_info(p, &w_curs, curpos,
1491 type, obj_offset, sizep);
1492 break;
1493 case OBJ_COMMIT:
1494 case OBJ_TREE:
1495 case OBJ_BLOB:
1496 case OBJ_TAG:
1497 if (sizep)
1498 *sizep = size;
1499 break;
1500 default:
1501 error("unknown object type %i at offset %"PRIuMAX" in %s",
1502 type, (uintmax_t)obj_offset, p->pack_name);
1503 type = OBJ_BAD;
1504 }
1505 unuse_pack(&w_curs);
1506 return type;
1507 }
1509 static void *unpack_compressed_entry(struct packed_git *p,
1510 struct pack_window **w_curs,
1511 off_t curpos,
1512 unsigned long size)
1513 {
1514 int st;
1515 z_stream stream;
1516 unsigned char *buffer, *in;
1518 buffer = xmallocz(size);
1519 memset(&stream, 0, sizeof(stream));
1520 stream.next_out = buffer;
1521 stream.avail_out = size + 1;
1523 git_inflate_init(&stream);
1524 do {
1525 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1526 stream.next_in = in;
1527 st = git_inflate(&stream, Z_FINISH);
1528 if (!stream.avail_out)
1529 break; /* the payload is larger than it should be */
1530 curpos += stream.next_in - in;
1531 } while (st == Z_OK || st == Z_BUF_ERROR);
1532 git_inflate_end(&stream);
1533 if ((st != Z_STREAM_END) || stream.total_out != size) {
1534 free(buffer);
1535 return NULL;
1536 }
1538 return buffer;
1539 }
1541 #define MAX_DELTA_CACHE (256)
1543 static size_t delta_base_cached;
1545 static struct delta_base_cache_lru_list {
1546 struct delta_base_cache_lru_list *prev;
1547 struct delta_base_cache_lru_list *next;
1548 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1550 static struct delta_base_cache_entry {
1551 struct delta_base_cache_lru_list lru;
1552 void *data;
1553 struct packed_git *p;
1554 off_t base_offset;
1555 unsigned long size;
1556 enum object_type type;
1557 } delta_base_cache[MAX_DELTA_CACHE];
1559 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1560 {
1561 unsigned long hash;
1563 hash = (unsigned long)p + (unsigned long)base_offset;
1564 hash += (hash >> 8) + (hash >> 16);
1565 return hash % MAX_DELTA_CACHE;
1566 }
1568 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1569 unsigned long *base_size, enum object_type *type, int keep_cache)
1570 {
1571 void *ret;
1572 unsigned long hash = pack_entry_hash(p, base_offset);
1573 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1575 ret = ent->data;
1576 if (!ret || ent->p != p || ent->base_offset != base_offset)
1577 return unpack_entry(p, base_offset, type, base_size);
1579 if (!keep_cache) {
1580 ent->data = NULL;
1581 ent->lru.next->prev = ent->lru.prev;
1582 ent->lru.prev->next = ent->lru.next;
1583 delta_base_cached -= ent->size;
1584 } else {
1585 ret = xmemdupz(ent->data, ent->size);
1586 }
1587 *type = ent->type;
1588 *base_size = ent->size;
1589 return ret;
1590 }
1592 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1593 {
1594 if (ent->data) {
1595 free(ent->data);
1596 ent->data = NULL;
1597 ent->lru.next->prev = ent->lru.prev;
1598 ent->lru.prev->next = ent->lru.next;
1599 delta_base_cached -= ent->size;
1600 }
1601 }
1603 void clear_delta_base_cache(void)
1604 {
1605 unsigned long p;
1606 for (p = 0; p < MAX_DELTA_CACHE; p++)
1607 release_delta_base_cache(&delta_base_cache[p]);
1608 }
1610 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1611 void *base, unsigned long base_size, enum object_type type)
1612 {
1613 unsigned long hash = pack_entry_hash(p, base_offset);
1614 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1615 struct delta_base_cache_lru_list *lru;
1617 release_delta_base_cache(ent);
1618 delta_base_cached += base_size;
1620 for (lru = delta_base_cache_lru.next;
1621 delta_base_cached > delta_base_cache_limit
1622 && lru != &delta_base_cache_lru;
1623 lru = lru->next) {
1624 struct delta_base_cache_entry *f = (void *)lru;
1625 if (f->type == OBJ_BLOB)
1626 release_delta_base_cache(f);
1627 }
1628 for (lru = delta_base_cache_lru.next;
1629 delta_base_cached > delta_base_cache_limit
1630 && lru != &delta_base_cache_lru;
1631 lru = lru->next) {
1632 struct delta_base_cache_entry *f = (void *)lru;
1633 release_delta_base_cache(f);
1634 }
1636 ent->p = p;
1637 ent->base_offset = base_offset;
1638 ent->type = type;
1639 ent->data = base;
1640 ent->size = base_size;
1641 ent->lru.next = &delta_base_cache_lru;
1642 ent->lru.prev = delta_base_cache_lru.prev;
1643 delta_base_cache_lru.prev->next = &ent->lru;
1644 delta_base_cache_lru.prev = &ent->lru;
1645 }
1647 static void *read_object(const unsigned char *sha1, enum object_type *type,
1648 unsigned long *size);
1650 static void *unpack_delta_entry(struct packed_git *p,
1651 struct pack_window **w_curs,
1652 off_t curpos,
1653 unsigned long delta_size,
1654 off_t obj_offset,
1655 enum object_type *type,
1656 unsigned long *sizep)
1657 {
1658 void *delta_data, *result, *base;
1659 unsigned long base_size;
1660 off_t base_offset;
1662 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1663 if (!base_offset) {
1664 error("failed to validate delta base reference "
1665 "at offset %"PRIuMAX" from %s",
1666 (uintmax_t)curpos, p->pack_name);
1667 return NULL;
1668 }
1669 unuse_pack(w_curs);
1670 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1671 if (!base) {
1672 /*
1673 * We're probably in deep shit, but let's try to fetch
1674 * the required base anyway from another pack or loose.
1675 * This is costly but should happen only in the presence
1676 * of a corrupted pack, and is better than failing outright.
1677 */
1678 struct revindex_entry *revidx;
1679 const unsigned char *base_sha1;
1680 revidx = find_pack_revindex(p, base_offset);
1681 if (!revidx)
1682 return NULL;
1683 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1684 error("failed to read delta base object %s"
1685 " at offset %"PRIuMAX" from %s",
1686 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1687 p->pack_name);
1688 mark_bad_packed_object(p, base_sha1);
1689 base = read_object(base_sha1, type, &base_size);
1690 if (!base)
1691 return NULL;
1692 }
1694 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1695 if (!delta_data) {
1696 error("failed to unpack compressed delta "
1697 "at offset %"PRIuMAX" from %s",
1698 (uintmax_t)curpos, p->pack_name);
1699 free(base);
1700 return NULL;
1701 }
1702 result = patch_delta(base, base_size,
1703 delta_data, delta_size,
1704 sizep);
1705 if (!result)
1706 die("failed to apply delta");
1707 free(delta_data);
1708 add_delta_base_cache(p, base_offset, base, base_size, *type);
1709 return result;
1710 }
1712 int do_check_packed_object_crc;
1714 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1715 enum object_type *type, unsigned long *sizep)
1716 {
1717 struct pack_window *w_curs = NULL;
1718 off_t curpos = obj_offset;
1719 void *data;
1721 if (do_check_packed_object_crc && p->index_version > 1) {
1722 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1723 unsigned long len = revidx[1].offset - obj_offset;
1724 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1725 const unsigned char *sha1 =
1726 nth_packed_object_sha1(p, revidx->nr);
1727 error("bad packed object CRC for %s",
1728 sha1_to_hex(sha1));
1729 mark_bad_packed_object(p, sha1);
1730 unuse_pack(&w_curs);
1731 return NULL;
1732 }
1733 }
1735 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1736 switch (*type) {
1737 case OBJ_OFS_DELTA:
1738 case OBJ_REF_DELTA:
1739 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1740 obj_offset, type, sizep);
1741 break;
1742 case OBJ_COMMIT:
1743 case OBJ_TREE:
1744 case OBJ_BLOB:
1745 case OBJ_TAG:
1746 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1747 break;
1748 default:
1749 data = NULL;
1750 error("unknown object type %i at offset %"PRIuMAX" in %s",
1751 *type, (uintmax_t)obj_offset, p->pack_name);
1752 }
1753 unuse_pack(&w_curs);
1754 return data;
1755 }
1757 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1758 uint32_t n)
1759 {
1760 const unsigned char *index = p->index_data;
1761 if (!index) {
1762 if (open_pack_index(p))
1763 return NULL;
1764 index = p->index_data;
1765 }
1766 if (n >= p->num_objects)
1767 return NULL;
1768 index += 4 * 256;
1769 if (p->index_version == 1) {
1770 return index + 24 * n + 4;
1771 } else {
1772 index += 8;
1773 return index + 20 * n;
1774 }
1775 }
1777 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1778 {
1779 const unsigned char *index = p->index_data;
1780 index += 4 * 256;
1781 if (p->index_version == 1) {
1782 return ntohl(*((uint32_t *)(index + 24 * n)));
1783 } else {
1784 uint32_t off;
1785 index += 8 + p->num_objects * (20 + 4);
1786 off = ntohl(*((uint32_t *)(index + 4 * n)));
1787 if (!(off & 0x80000000))
1788 return off;
1789 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1790 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1791 ntohl(*((uint32_t *)(index + 4)));
1792 }
1793 }
1795 off_t find_pack_entry_one(const unsigned char *sha1,
1796 struct packed_git *p)
1797 {
1798 const uint32_t *level1_ofs = p->index_data;
1799 const unsigned char *index = p->index_data;
1800 unsigned hi, lo, stride;
1801 static int use_lookup = -1;
1802 static int debug_lookup = -1;
1804 if (debug_lookup < 0)
1805 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
1807 if (!index) {
1808 if (open_pack_index(p))
1809 return 0;
1810 level1_ofs = p->index_data;
1811 index = p->index_data;
1812 }
1813 if (p->index_version > 1) {
1814 level1_ofs += 2;
1815 index += 8;
1816 }
1817 index += 4 * 256;
1818 hi = ntohl(level1_ofs[*sha1]);
1819 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1820 if (p->index_version > 1) {
1821 stride = 20;
1822 } else {
1823 stride = 24;
1824 index += 4;
1825 }
1827 if (debug_lookup)
1828 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
1829 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1831 if (use_lookup < 0)
1832 use_lookup = !!getenv("GIT_USE_LOOKUP");
1833 if (use_lookup) {
1834 int pos = sha1_entry_pos(index, stride, 0,
1835 lo, hi, p->num_objects, sha1);
1836 if (pos < 0)
1837 return 0;
1838 return nth_packed_object_offset(p, pos);
1839 }
1841 do {
1842 unsigned mi = (lo + hi) / 2;
1843 int cmp = hashcmp(index + mi * stride, sha1);
1845 if (debug_lookup)
1846 printf("lo %u hi %u rg %u mi %u\n",
1847 lo, hi, hi - lo, mi);
1848 if (!cmp)
1849 return nth_packed_object_offset(p, mi);
1850 if (cmp > 0)
1851 hi = mi;
1852 else
1853 lo = mi+1;
1854 } while (lo < hi);
1855 return 0;
1856 }
1858 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1859 {
1860 static struct packed_git *last_found = (void *)1;
1861 struct packed_git *p;
1862 off_t offset;
1864 prepare_packed_git();
1865 if (!packed_git)
1866 return 0;
1867 p = (last_found == (void *)1) ? packed_git : last_found;
1869 do {
1870 if (p->num_bad_objects) {
1871 unsigned i;
1872 for (i = 0; i < p->num_bad_objects; i++)
1873 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1874 goto next;
1875 }
1877 offset = find_pack_entry_one(sha1, p);
1878 if (offset) {
1879 /*
1880 * We are about to tell the caller where they can
1881 * locate the requested object. We better make
1882 * sure the packfile is still here and can be
1883 * accessed before supplying that answer, as
1884 * it may have been deleted since the index
1885 * was loaded!
1886 */
1887 if (p->pack_fd == -1 && open_packed_git(p)) {
1888 error("packfile %s cannot be accessed", p->pack_name);
1889 goto next;
1890 }
1891 e->offset = offset;
1892 e->p = p;
1893 hashcpy(e->sha1, sha1);
1894 last_found = p;
1895 return 1;
1896 }
1898 next:
1899 if (p == last_found)
1900 p = packed_git;
1901 else
1902 p = p->next;
1903 if (p == last_found)
1904 p = p->next;
1905 } while (p);
1906 return 0;
1907 }
1909 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1910 struct packed_git *packs)
1911 {
1912 struct packed_git *p;
1914 for (p = packs; p; p = p->next) {
1915 if (find_pack_entry_one(sha1, p))
1916 return p;
1917 }
1918 return NULL;
1920 }
1922 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1923 {
1924 int status;
1925 unsigned long mapsize, size;
1926 void *map;
1927 z_stream stream;
1928 char hdr[32];
1930 map = map_sha1_file(sha1, &mapsize);
1931 if (!map)
1932 return error("unable to find %s", sha1_to_hex(sha1));
1933 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1934 status = error("unable to unpack %s header",
1935 sha1_to_hex(sha1));
1936 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1937 status = error("unable to parse %s header", sha1_to_hex(sha1));
1938 else if (sizep)
1939 *sizep = size;
1940 git_inflate_end(&stream);
1941 munmap(map, mapsize);
1942 return status;
1943 }
1945 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1946 {
1947 struct pack_entry e;
1948 int status;
1950 if (!find_pack_entry(sha1, &e)) {
1951 /* Most likely it's a loose object. */
1952 status = sha1_loose_object_info(sha1, sizep);
1953 if (status >= 0)
1954 return status;
1956 /* Not a loose object; someone else may have just packed it. */
1957 reprepare_packed_git();
1958 if (!find_pack_entry(sha1, &e))
1959 return status;
1960 }
1962 status = packed_object_info(e.p, e.offset, sizep);
1963 if (status < 0) {
1964 mark_bad_packed_object(e.p, sha1);
1965 status = sha1_object_info(sha1, sizep);
1966 }
1968 return status;
1969 }
1971 static void *read_packed_sha1(const unsigned char *sha1,
1972 enum object_type *type, unsigned long *size)
1973 {
1974 struct pack_entry e;
1975 void *data;
1977 if (!find_pack_entry(sha1, &e))
1978 return NULL;
1979 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1980 if (!data) {
1981 /*
1982 * We're probably in deep shit, but let's try to fetch
1983 * the required object anyway from another pack or loose.
1984 * This should happen only in the presence of a corrupted
1985 * pack, and is better than failing outright.
1986 */
1987 error("failed to read object %s at offset %"PRIuMAX" from %s",
1988 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1989 mark_bad_packed_object(e.p, sha1);
1990 data = read_object(sha1, type, size);
1991 }
1992 return data;
1993 }
1995 /*
1996 * This is meant to hold a *small* number of objects that you would
1997 * want read_sha1_file() to be able to return, but yet you do not want
1998 * to write them into the object store (e.g. a browse-only
1999 * application).
2000 */
2001 static struct cached_object {
2002 unsigned char sha1[20];
2003 enum object_type type;
2004 void *buf;
2005 unsigned long size;
2006 } *cached_objects;
2007 static int cached_object_nr, cached_object_alloc;
2009 static struct cached_object empty_tree = {
2010 EMPTY_TREE_SHA1_BIN,
2011 OBJ_TREE,
2012 "",
2013 0
2014 };
2016 static struct cached_object *find_cached_object(const unsigned char *sha1)
2017 {
2018 int i;
2019 struct cached_object *co = cached_objects;
2021 for (i = 0; i < cached_object_nr; i++, co++) {
2022 if (!hashcmp(co->sha1, sha1))
2023 return co;
2024 }
2025 if (!hashcmp(sha1, empty_tree.sha1))
2026 return &empty_tree;
2027 return NULL;
2028 }
2030 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2031 unsigned char *sha1)
2032 {
2033 struct cached_object *co;
2035 hash_sha1_file(buf, len, typename(type), sha1);
2036 if (has_sha1_file(sha1) || find_cached_object(sha1))
2037 return 0;
2038 if (cached_object_alloc <= cached_object_nr) {
2039 cached_object_alloc = alloc_nr(cached_object_alloc);
2040 cached_objects = xrealloc(cached_objects,
2041 sizeof(*cached_objects) *
2042 cached_object_alloc);
2043 }
2044 co = &cached_objects[cached_object_nr++];
2045 co->size = len;
2046 co->type = type;
2047 co->buf = xmalloc(len);
2048 memcpy(co->buf, buf, len);
2049 hashcpy(co->sha1, sha1);
2050 return 0;
2051 }
2053 static void *read_object(const unsigned char *sha1, enum object_type *type,
2054 unsigned long *size)
2055 {
2056 unsigned long mapsize;
2057 void *map, *buf;
2058 struct cached_object *co;
2060 co = find_cached_object(sha1);
2061 if (co) {
2062 *type = co->type;
2063 *size = co->size;
2064 return xmemdupz(co->buf, co->size);
2065 }
2067 buf = read_packed_sha1(sha1, type, size);
2068 if (buf)
2069 return buf;
2070 map = map_sha1_file(sha1, &mapsize);
2071 if (map) {
2072 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2073 munmap(map, mapsize);
2074 return buf;
2075 }
2076 reprepare_packed_git();
2077 return read_packed_sha1(sha1, type, size);
2078 }
2080 void *read_sha1_file_repl(const unsigned char *sha1,
2081 enum object_type *type,
2082 unsigned long *size,
2083 const unsigned char **replacement)
2084 {
2085 const unsigned char *repl = lookup_replace_object(sha1);
2086 void *data = read_object(repl, type, size);
2088 /* die if we replaced an object with one that does not exist */
2089 if (!data && repl != sha1)
2090 die("replacement %s not found for %s",
2091 sha1_to_hex(repl), sha1_to_hex(sha1));
2093 /* legacy behavior is to die on corrupted objects */
2094 if (!data && (has_loose_object(repl) || has_packed_and_bad(repl)))
2095 die("object %s is corrupted", sha1_to_hex(repl));
2097 if (replacement)
2098 *replacement = repl;
2100 return data;
2101 }
2103 void *read_object_with_reference(const unsigned char *sha1,
2104 const char *required_type_name,
2105 unsigned long *size,
2106 unsigned char *actual_sha1_return)
2107 {
2108 enum object_type type, required_type;
2109 void *buffer;
2110 unsigned long isize;
2111 unsigned char actual_sha1[20];
2113 required_type = type_from_string(required_type_name);
2114 hashcpy(actual_sha1, sha1);
2115 while (1) {
2116 int ref_length = -1;
2117 const char *ref_type = NULL;
2119 buffer = read_sha1_file(actual_sha1, &type, &isize);
2120 if (!buffer)
2121 return NULL;
2122 if (type == required_type) {
2123 *size = isize;
2124 if (actual_sha1_return)
2125 hashcpy(actual_sha1_return, actual_sha1);
2126 return buffer;
2127 }
2128 /* Handle references */
2129 else if (type == OBJ_COMMIT)
2130 ref_type = "tree ";
2131 else if (type == OBJ_TAG)
2132 ref_type = "object ";
2133 else {
2134 free(buffer);
2135 return NULL;
2136 }
2137 ref_length = strlen(ref_type);
2139 if (ref_length + 40 > isize ||
2140 memcmp(buffer, ref_type, ref_length) ||
2141 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2142 free(buffer);
2143 return NULL;
2144 }
2145 free(buffer);
2146 /* Now we have the ID of the referred-to object in
2147 * actual_sha1. Check again. */
2148 }
2149 }
2151 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2152 const char *type, unsigned char *sha1,
2153 char *hdr, int *hdrlen)
2154 {
2155 git_SHA_CTX c;
2157 /* Generate the header */
2158 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2160 /* Sha1.. */
2161 git_SHA1_Init(&c);
2162 git_SHA1_Update(&c, hdr, *hdrlen);
2163 git_SHA1_Update(&c, buf, len);
2164 git_SHA1_Final(sha1, &c);
2165 }
2167 /*
2168 * Move the just written object into its final resting place.
2169 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2170 * "moving" is only a part of what it does, when no patch between
2171 * master to pu changes the call sites of this function.
2172 */
2173 int move_temp_to_file(const char *tmpfile, const char *filename)
2174 {
2175 int ret = 0;
2177 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
2178 goto try_rename;
2179 else if (link(tmpfile, filename))
2180 ret = errno;
2182 /*
2183 * Coda hack - coda doesn't like cross-directory links,
2184 * so we fall back to a rename, which will mean that it
2185 * won't be able to check collisions, but that's not a
2186 * big deal.
2187 *
2188 * The same holds for FAT formatted media.
2189 *
2190 * When this succeeds, we just return. We have nothing
2191 * left to unlink.
2192 */
2193 if (ret && ret != EEXIST) {
2194 try_rename:
2195 if (!rename(tmpfile, filename))
2196 goto out;
2197 ret = errno;
2198 }
2199 unlink_or_warn(tmpfile);
2200 if (ret) {
2201 if (ret != EEXIST) {
2202 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
2203 }
2204 /* FIXME!!! Collision check here ? */
2205 }
2207 out:
2208 if (adjust_shared_perm(filename))
2209 return error("unable to set permission to '%s'", filename);
2210 return 0;
2211 }
2213 static int write_buffer(int fd, const void *buf, size_t len)
2214 {
2215 if (write_in_full(fd, buf, len) < 0)
2216 return error("file write error (%s)", strerror(errno));
2217 return 0;
2218 }
2220 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2221 unsigned char *sha1)
2222 {
2223 char hdr[32];
2224 int hdrlen;
2225 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2226 return 0;
2227 }
2229 /* Finalize a file on disk, and close it. */
2230 static void close_sha1_file(int fd)
2231 {
2232 if (fsync_object_files)
2233 fsync_or_die(fd, "sha1 file");
2234 if (close(fd) != 0)
2235 die_errno("error when closing sha1 file");
2236 }
2238 /* Size of directory component, including the ending '/' */
2239 static inline int directory_size(const char *filename)
2240 {
2241 const char *s = strrchr(filename, '/');
2242 if (!s)
2243 return 0;
2244 return s - filename + 1;
2245 }
2247 /*
2248 * This creates a temporary file in the same directory as the final
2249 * 'filename'
2250 *
2251 * We want to avoid cross-directory filename renames, because those
2252 * can have problems on various filesystems (FAT, NFS, Coda).
2253 */
2254 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2255 {
2256 int fd, dirlen = directory_size(filename);
2258 if (dirlen + 20 > bufsiz) {
2259 errno = ENAMETOOLONG;
2260 return -1;
2261 }
2262 memcpy(buffer, filename, dirlen);
2263 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2264 fd = git_mkstemp_mode(buffer, 0444);
2265 if (fd < 0 && dirlen && errno == ENOENT) {
2266 /* Make sure the directory exists */
2267 memcpy(buffer, filename, dirlen);
2268 buffer[dirlen-1] = 0;
2269 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2270 return -1;
2272 /* Try again */
2273 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2274 fd = git_mkstemp_mode(buffer, 0444);
2275 }
2276 return fd;
2277 }
2279 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2280 const void *buf, unsigned long len, time_t mtime)
2281 {
2282 int fd, ret;
2283 unsigned char compressed[4096];
2284 z_stream stream;
2285 git_SHA_CTX c;
2286 unsigned char parano_sha1[20];
2287 char *filename;
2288 static char tmpfile[PATH_MAX];
2290 filename = sha1_file_name(sha1);
2291 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2292 while (fd < 0 && errno == EMFILE && unuse_one_window(packed_git, -1))
2293 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2294 if (fd < 0) {
2295 if (errno == EACCES)
2296 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2297 else
2298 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2299 }
2301 /* Set it up */
2302 memset(&stream, 0, sizeof(stream));
2303 deflateInit(&stream, zlib_compression_level);
2304 stream.next_out = compressed;
2305 stream.avail_out = sizeof(compressed);
2306 git_SHA1_Init(&c);
2308 /* First header.. */
2309 stream.next_in = (unsigned char *)hdr;
2310 stream.avail_in = hdrlen;
2311 while (deflate(&stream, 0) == Z_OK)
2312 /* nothing */;
2313 git_SHA1_Update(&c, hdr, hdrlen);
2315 /* Then the data itself.. */
2316 stream.next_in = (void *)buf;
2317 stream.avail_in = len;
2318 do {
2319 unsigned char *in0 = stream.next_in;
2320 ret = deflate(&stream, Z_FINISH);
2321 git_SHA1_Update(&c, in0, stream.next_in - in0);
2322 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2323 die("unable to write sha1 file");
2324 stream.next_out = compressed;
2325 stream.avail_out = sizeof(compressed);
2326 } while (ret == Z_OK);
2328 if (ret != Z_STREAM_END)
2329 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2330 ret = deflateEnd(&stream);
2331 if (ret != Z_OK)
2332 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2333 git_SHA1_Final(parano_sha1, &c);
2334 if (hashcmp(sha1, parano_sha1) != 0)
2335 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
2337 close_sha1_file(fd);
2339 if (mtime) {
2340 struct utimbuf utb;
2341 utb.actime = mtime;
2342 utb.modtime = mtime;
2343 if (utime(tmpfile, &utb) < 0)
2344 warning("failed utime() on %s: %s",
2345 tmpfile, strerror(errno));
2346 }
2348 return move_temp_to_file(tmpfile, filename);
2349 }
2351 int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2352 {
2353 unsigned char sha1[20];
2354 char hdr[32];
2355 int hdrlen;
2357 /* Normally if we have it in the pack then we do not bother writing
2358 * it out into .git/objects/??/?{38} file.
2359 */
2360 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2361 if (returnsha1)
2362 hashcpy(returnsha1, sha1);
2363 if (has_sha1_file(sha1))
2364 return 0;
2365 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2366 }
2368 int force_object_loose(const unsigned char *sha1, time_t mtime)
2369 {
2370 void *buf;
2371 unsigned long len;
2372 enum object_type type;
2373 char hdr[32];
2374 int hdrlen;
2375 int ret;
2377 if (has_loose_object(sha1))
2378 return 0;
2379 buf = read_packed_sha1(sha1, &type, &len);
2380 if (!buf)
2381 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2382 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2383 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2384 free(buf);
2386 return ret;
2387 }
2389 int has_pack_index(const unsigned char *sha1)
2390 {
2391 struct stat st;
2392 if (stat(sha1_pack_index_name(sha1), &st))
2393 return 0;
2394 return 1;
2395 }
2397 int has_sha1_pack(const unsigned char *sha1)
2398 {
2399 struct pack_entry e;
2400 return find_pack_entry(sha1, &e);
2401 }
2403 int has_sha1_file(const unsigned char *sha1)
2404 {
2405 struct pack_entry e;
2407 if (find_pack_entry(sha1, &e))
2408 return 1;
2409 return has_loose_object(sha1);
2410 }
2412 static int index_mem(unsigned char *sha1, void *buf, size_t size,
2413 int write_object, enum object_type type, const char *path)
2414 {
2415 int ret, re_allocated = 0;
2417 if (!type)
2418 type = OBJ_BLOB;
2420 /*
2421 * Convert blobs to git internal format
2422 */
2423 if ((type == OBJ_BLOB) && path) {
2424 struct strbuf nbuf = STRBUF_INIT;
2425 if (convert_to_git(path, buf, size, &nbuf,
2426 write_object ? safe_crlf : 0)) {
2427 buf = strbuf_detach(&nbuf, &size);
2428 re_allocated = 1;
2429 }
2430 }
2432 if (write_object)
2433 ret = write_sha1_file(buf, size, typename(type), sha1);
2434 else
2435 ret = hash_sha1_file(buf, size, typename(type), sha1);
2436 if (re_allocated)
2437 free(buf);
2438 return ret;
2439 }
2441 #define SMALL_FILE_SIZE (32*1024)
2443 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2444 enum object_type type, const char *path)
2445 {
2446 int ret;
2447 size_t size = xsize_t(st->st_size);
2449 if (!S_ISREG(st->st_mode)) {
2450 struct strbuf sbuf = STRBUF_INIT;
2451 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2452 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2453 type, path);
2454 else
2455 ret = -1;
2456 strbuf_release(&sbuf);
2457 } else if (!size) {
2458 ret = index_mem(sha1, NULL, size, write_object, type, path);
2459 } else if (size <= SMALL_FILE_SIZE) {
2460 char *buf = xmalloc(size);
2461 if (size == read_in_full(fd, buf, size))
2462 ret = index_mem(sha1, buf, size, write_object, type,
2463 path);
2464 else
2465 ret = error("short read %s", strerror(errno));
2466 free(buf);
2467 } else {
2468 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2469 ret = index_mem(sha1, buf, size, write_object, type, path);
2470 munmap(buf, size);
2471 }
2472 close(fd);
2473 return ret;
2474 }
2476 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2477 {
2478 int fd;
2479 struct strbuf sb = STRBUF_INIT;
2481 switch (st->st_mode & S_IFMT) {
2482 case S_IFREG:
2483 fd = open(path, O_RDONLY);
2484 if (fd < 0)
2485 return error("open(\"%s\"): %s", path,
2486 strerror(errno));
2487 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2488 return error("%s: failed to insert into database",
2489 path);
2490 break;
2491 case S_IFLNK:
2492 if (strbuf_readlink(&sb, path, st->st_size)) {
2493 char *errstr = strerror(errno);
2494 return error("readlink(\"%s\"): %s", path,
2495 errstr);
2496 }
2497 if (!write_object)
2498 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2499 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
2500 return error("%s: failed to insert into database",
2501 path);
2502 strbuf_release(&sb);
2503 break;
2504 case S_IFDIR:
2505 return resolve_gitlink_ref(path, "HEAD", sha1);
2506 default:
2507 return error("%s: unsupported file type", path);
2508 }
2509 return 0;
2510 }
2512 int read_pack_header(int fd, struct pack_header *header)
2513 {
2514 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2515 /* "eof before pack header was fully read" */
2516 return PH_ERROR_EOF;
2518 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2519 /* "protocol error (pack signature mismatch detected)" */
2520 return PH_ERROR_PACK_SIGNATURE;
2521 if (!pack_version_ok(header->hdr_version))
2522 /* "protocol error (pack version unsupported)" */
2523 return PH_ERROR_PROTOCOL;
2524 return 0;
2525 }