Fix 'git diff --no-index' with a non-existing symlink target
[git/spearce.git] / sha1_file.c
blob8868b800cbb9259f97b8acac3c8701153118b657
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
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 const signed char hexval_table[256] = {
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
42 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
45 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
46 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
47 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
51 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
68 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
69 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
70 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
73 int get_sha1_hex(const char *hex, unsigned char *sha1)
75 int i;
76 for (i = 0; i < 20; i++) {
77 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
78 if (val & ~0xff)
79 return -1;
80 *sha1++ = val;
81 hex += 2;
83 return 0;
86 static inline int offset_1st_component(const char *path)
88 if (has_dos_drive_prefix(path))
89 return 2 + (path[2] == '/');
90 return *path == '/';
93 int safe_create_leading_directories(char *path)
95 char *pos = path + offset_1st_component(path);
96 struct stat st;
98 while (pos) {
99 pos = strchr(pos, '/');
100 if (!pos)
101 break;
102 while (*++pos == '/')
104 if (!*pos)
105 break;
106 *--pos = '\0';
107 if (!stat(path, &st)) {
108 /* path exists */
109 if (!S_ISDIR(st.st_mode)) {
110 *pos = '/';
111 return -3;
114 else if (mkdir(path, 0777)) {
115 *pos = '/';
116 return -1;
118 else if (adjust_shared_perm(path)) {
119 *pos = '/';
120 return -2;
122 *pos++ = '/';
124 return 0;
127 int safe_create_leading_directories_const(const char *path)
129 /* path points to cache entries, so xstrdup before messing with it */
130 char *buf = xstrdup(path);
131 int result = safe_create_leading_directories(buf);
132 free(buf);
133 return result;
136 char *sha1_to_hex(const unsigned char *sha1)
138 static int bufno;
139 static char hexbuffer[4][50];
140 static const char hex[] = "0123456789abcdef";
141 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
142 int i;
144 for (i = 0; i < 20; i++) {
145 unsigned int val = *sha1++;
146 *buf++ = hex[val >> 4];
147 *buf++ = hex[val & 0xf];
149 *buf = '\0';
151 return buffer;
154 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
156 int i;
157 for (i = 0; i < 20; i++) {
158 static char hex[] = "0123456789abcdef";
159 unsigned int val = sha1[i];
160 char *pos = pathbuf + i*2 + (i > 0);
161 *pos++ = hex[val >> 4];
162 *pos = hex[val & 0xf];
167 * NOTE! This returns a statically allocated buffer, so you have to be
168 * careful about using it. Do an "xstrdup()" if you need to save the
169 * filename.
171 * Also note that this returns the location for creating. Reading
172 * SHA1 file can happen from any alternate directory listed in the
173 * DB_ENVIRONMENT environment variable if it is not found in
174 * the primary object database.
176 char *sha1_file_name(const unsigned char *sha1)
178 static char *name, *base;
180 if (!base) {
181 const char *sha1_file_directory = get_object_directory();
182 int len = strlen(sha1_file_directory);
183 base = xmalloc(len + 60);
184 memcpy(base, sha1_file_directory, len);
185 memset(base+len, 0, 60);
186 base[len] = '/';
187 base[len+3] = '/';
188 name = base + len + 1;
190 fill_sha1_path(name, sha1);
191 return base;
194 static char *sha1_get_pack_name(const unsigned char *sha1,
195 char **name, char **base, const char *which)
197 static const char hex[] = "0123456789abcdef";
198 char *buf;
199 int i;
201 if (!*base) {
202 const char *sha1_file_directory = get_object_directory();
203 int len = strlen(sha1_file_directory);
204 *base = xmalloc(len + 60);
205 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
206 sha1_file_directory, which);
207 *name = *base + len + 11;
210 buf = *name;
212 for (i = 0; i < 20; i++) {
213 unsigned int val = *sha1++;
214 *buf++ = hex[val >> 4];
215 *buf++ = hex[val & 0xf];
218 return *base;
221 char *sha1_pack_name(const unsigned char *sha1)
223 static char *name, *base;
225 return sha1_get_pack_name(sha1, &name, &base, "pack");
228 char *sha1_pack_index_name(const unsigned char *sha1)
230 static char *name, *base;
232 return sha1_get_pack_name(sha1, &name, &base, "idx");
235 struct alternate_object_database *alt_odb_list;
236 static struct alternate_object_database **alt_odb_tail;
238 static void read_info_alternates(const char * alternates, int depth);
241 * Prepare alternate object database registry.
243 * The variable alt_odb_list points at the list of struct
244 * alternate_object_database. The elements on this list come from
245 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
246 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
247 * whose contents is similar to that environment variable but can be
248 * LF separated. Its base points at a statically allocated buffer that
249 * contains "/the/directory/corresponding/to/.git/objects/...", while
250 * its name points just after the slash at the end of ".git/objects/"
251 * in the example above, and has enough space to hold 40-byte hex
252 * SHA1, an extra slash for the first level indirection, and the
253 * terminating NUL.
255 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
257 const char *objdir = get_object_directory();
258 struct alternate_object_database *ent;
259 struct alternate_object_database *alt;
260 /* 43 = 40-byte + 2 '/' + terminating NUL */
261 int pfxlen = len;
262 int entlen = pfxlen + 43;
263 int base_len = -1;
265 if (!is_absolute_path(entry) && relative_base) {
266 /* Relative alt-odb */
267 if (base_len < 0)
268 base_len = strlen(relative_base) + 1;
269 entlen += base_len;
270 pfxlen += base_len;
272 ent = xmalloc(sizeof(*ent) + entlen);
274 if (!is_absolute_path(entry) && relative_base) {
275 memcpy(ent->base, relative_base, base_len - 1);
276 ent->base[base_len - 1] = '/';
277 memcpy(ent->base + base_len, entry, len);
279 else
280 memcpy(ent->base, entry, pfxlen);
282 ent->name = ent->base + pfxlen + 1;
283 ent->base[pfxlen + 3] = '/';
284 ent->base[pfxlen] = ent->base[entlen-1] = 0;
286 /* Detect cases where alternate disappeared */
287 if (!is_directory(ent->base)) {
288 error("object directory %s does not exist; "
289 "check .git/objects/info/alternates.",
290 ent->base);
291 free(ent);
292 return -1;
295 /* Prevent the common mistake of listing the same
296 * thing twice, or object directory itself.
298 for (alt = alt_odb_list; alt; alt = alt->next) {
299 if (!memcmp(ent->base, alt->base, pfxlen)) {
300 free(ent);
301 return -1;
304 if (!memcmp(ent->base, objdir, pfxlen)) {
305 free(ent);
306 return -1;
309 /* add the alternate entry */
310 *alt_odb_tail = ent;
311 alt_odb_tail = &(ent->next);
312 ent->next = NULL;
314 /* recursively add alternates */
315 read_info_alternates(ent->base, depth + 1);
317 ent->base[pfxlen] = '/';
319 return 0;
322 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
323 const char *relative_base, int depth)
325 const char *cp, *last;
327 if (depth > 5) {
328 error("%s: ignoring alternate object stores, nesting too deep.",
329 relative_base);
330 return;
333 last = alt;
334 while (last < ep) {
335 cp = last;
336 if (cp < ep && *cp == '#') {
337 while (cp < ep && *cp != sep)
338 cp++;
339 last = cp + 1;
340 continue;
342 while (cp < ep && *cp != sep)
343 cp++;
344 if (last != cp) {
345 if (!is_absolute_path(last) && depth) {
346 error("%s: ignoring relative alternate object store %s",
347 relative_base, last);
348 } else {
349 link_alt_odb_entry(last, cp - last,
350 relative_base, depth);
353 while (cp < ep && *cp == sep)
354 cp++;
355 last = cp;
359 static void read_info_alternates(const char * relative_base, int depth)
361 char *map;
362 size_t mapsz;
363 struct stat st;
364 const char alt_file_name[] = "info/alternates";
365 /* Given that relative_base is no longer than PATH_MAX,
366 ensure that "path" has enough space to append "/", the
367 file name, "info/alternates", and a trailing NUL. */
368 char path[PATH_MAX + 1 + sizeof alt_file_name];
369 int fd;
371 sprintf(path, "%s/%s", relative_base, alt_file_name);
372 fd = open(path, O_RDONLY);
373 if (fd < 0)
374 return;
375 if (fstat(fd, &st) || (st.st_size == 0)) {
376 close(fd);
377 return;
379 mapsz = xsize_t(st.st_size);
380 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
381 close(fd);
383 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
385 munmap(map, mapsz);
388 void add_to_alternates_file(const char *reference)
390 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
391 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
392 char *alt = mkpath("%s/objects\n", reference);
393 write_or_die(fd, alt, strlen(alt));
394 if (commit_lock_file(lock))
395 die("could not close alternates file");
396 if (alt_odb_tail)
397 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
400 void foreach_alt_odb(alt_odb_fn fn, void *cb)
402 struct alternate_object_database *ent;
404 prepare_alt_odb();
405 for (ent = alt_odb_list; ent; ent = ent->next)
406 if (fn(ent, cb))
407 return;
410 void prepare_alt_odb(void)
412 const char *alt;
414 if (alt_odb_tail)
415 return;
417 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
418 if (!alt) alt = "";
420 alt_odb_tail = &alt_odb_list;
421 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
423 read_info_alternates(get_object_directory(), 0);
426 static int has_loose_object_local(const unsigned char *sha1)
428 char *name = sha1_file_name(sha1);
429 return !access(name, F_OK);
432 int has_loose_object_nonlocal(const unsigned char *sha1)
434 struct alternate_object_database *alt;
435 prepare_alt_odb();
436 for (alt = alt_odb_list; alt; alt = alt->next) {
437 fill_sha1_path(alt->name, sha1);
438 if (!access(alt->base, F_OK))
439 return 1;
441 return 0;
444 static int has_loose_object(const unsigned char *sha1)
446 return has_loose_object_local(sha1) ||
447 has_loose_object_nonlocal(sha1);
450 static unsigned int pack_used_ctr;
451 static unsigned int pack_mmap_calls;
452 static unsigned int peak_pack_open_windows;
453 static unsigned int pack_open_windows;
454 static size_t peak_pack_mapped;
455 static size_t pack_mapped;
456 struct packed_git *packed_git;
458 void pack_report(void)
460 fprintf(stderr,
461 "pack_report: getpagesize() = %10" SZ_FMT "\n"
462 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
463 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
464 sz_fmt(getpagesize()),
465 sz_fmt(packed_git_window_size),
466 sz_fmt(packed_git_limit));
467 fprintf(stderr,
468 "pack_report: pack_used_ctr = %10u\n"
469 "pack_report: pack_mmap_calls = %10u\n"
470 "pack_report: pack_open_windows = %10u / %10u\n"
471 "pack_report: pack_mapped = "
472 "%10" SZ_FMT " / %10" SZ_FMT "\n",
473 pack_used_ctr,
474 pack_mmap_calls,
475 pack_open_windows, peak_pack_open_windows,
476 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
479 static int check_packed_git_idx(const char *path, struct packed_git *p)
481 void *idx_map;
482 struct pack_idx_header *hdr;
483 size_t idx_size;
484 uint32_t version, nr, i, *index;
485 int fd = open(path, O_RDONLY);
486 struct stat st;
488 if (fd < 0)
489 return -1;
490 if (fstat(fd, &st)) {
491 close(fd);
492 return -1;
494 idx_size = xsize_t(st.st_size);
495 if (idx_size < 4 * 256 + 20 + 20) {
496 close(fd);
497 return error("index file %s is too small", path);
499 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
500 close(fd);
502 hdr = idx_map;
503 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
504 version = ntohl(hdr->idx_version);
505 if (version < 2 || version > 2) {
506 munmap(idx_map, idx_size);
507 return error("index file %s is version %"PRIu32
508 " and is not supported by this binary"
509 " (try upgrading GIT to a newer version)",
510 path, version);
512 } else
513 version = 1;
515 nr = 0;
516 index = idx_map;
517 if (version > 1)
518 index += 2; /* skip index header */
519 for (i = 0; i < 256; i++) {
520 uint32_t n = ntohl(index[i]);
521 if (n < nr) {
522 munmap(idx_map, idx_size);
523 return error("non-monotonic index %s", path);
525 nr = n;
528 if (version == 1) {
530 * Total size:
531 * - 256 index entries 4 bytes each
532 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
533 * - 20-byte SHA1 of the packfile
534 * - 20-byte SHA1 file checksum
536 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
537 munmap(idx_map, idx_size);
538 return error("wrong index v1 file size in %s", path);
540 } else if (version == 2) {
542 * Minimum size:
543 * - 8 bytes of header
544 * - 256 index entries 4 bytes each
545 * - 20-byte sha1 entry * nr
546 * - 4-byte crc entry * nr
547 * - 4-byte offset entry * nr
548 * - 20-byte SHA1 of the packfile
549 * - 20-byte SHA1 file checksum
550 * And after the 4-byte offset table might be a
551 * variable sized table containing 8-byte entries
552 * for offsets larger than 2^31.
554 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
555 unsigned long max_size = min_size;
556 if (nr)
557 max_size += (nr - 1)*8;
558 if (idx_size < min_size || idx_size > max_size) {
559 munmap(idx_map, idx_size);
560 return error("wrong index v2 file size in %s", path);
562 if (idx_size != min_size &&
564 * make sure we can deal with large pack offsets.
565 * 31-bit signed offset won't be enough, neither
566 * 32-bit unsigned one will be.
568 (sizeof(off_t) <= 4)) {
569 munmap(idx_map, idx_size);
570 return error("pack too large for current definition of off_t in %s", path);
574 p->index_version = version;
575 p->index_data = idx_map;
576 p->index_size = idx_size;
577 p->num_objects = nr;
578 return 0;
581 int open_pack_index(struct packed_git *p)
583 char *idx_name;
584 int ret;
586 if (p->index_data)
587 return 0;
589 idx_name = xstrdup(p->pack_name);
590 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
591 ret = check_packed_git_idx(idx_name, p);
592 free(idx_name);
593 return ret;
596 static void scan_windows(struct packed_git *p,
597 struct packed_git **lru_p,
598 struct pack_window **lru_w,
599 struct pack_window **lru_l)
601 struct pack_window *w, *w_l;
603 for (w_l = NULL, w = p->windows; w; w = w->next) {
604 if (!w->inuse_cnt) {
605 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
606 *lru_p = p;
607 *lru_w = w;
608 *lru_l = w_l;
611 w_l = w;
615 static int unuse_one_window(struct packed_git *current, int keep_fd)
617 struct packed_git *p, *lru_p = NULL;
618 struct pack_window *lru_w = NULL, *lru_l = NULL;
620 if (current)
621 scan_windows(current, &lru_p, &lru_w, &lru_l);
622 for (p = packed_git; p; p = p->next)
623 scan_windows(p, &lru_p, &lru_w, &lru_l);
624 if (lru_p) {
625 munmap(lru_w->base, lru_w->len);
626 pack_mapped -= lru_w->len;
627 if (lru_l)
628 lru_l->next = lru_w->next;
629 else {
630 lru_p->windows = lru_w->next;
631 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
632 close(lru_p->pack_fd);
633 lru_p->pack_fd = -1;
636 free(lru_w);
637 pack_open_windows--;
638 return 1;
640 return 0;
643 void release_pack_memory(size_t need, int fd)
645 size_t cur = pack_mapped;
646 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
647 ; /* nothing */
650 void close_pack_windows(struct packed_git *p)
652 while (p->windows) {
653 struct pack_window *w = p->windows;
655 if (w->inuse_cnt)
656 die("pack '%s' still has open windows to it",
657 p->pack_name);
658 munmap(w->base, w->len);
659 pack_mapped -= w->len;
660 pack_open_windows--;
661 p->windows = w->next;
662 free(w);
666 void unuse_pack(struct pack_window **w_cursor)
668 struct pack_window *w = *w_cursor;
669 if (w) {
670 w->inuse_cnt--;
671 *w_cursor = NULL;
676 * This is used by git-repack in case a newly created pack happens to
677 * contain the same set of objects as an existing one. In that case
678 * the resulting file might be different even if its name would be the
679 * same. It is best to close any reference to the old pack before it is
680 * replaced on disk. Of course no index pointers nor windows for given pack
681 * must subsist at this point. If ever objects from this pack are requested
682 * again, the new version of the pack will be reinitialized through
683 * reprepare_packed_git().
685 void free_pack_by_name(const char *pack_name)
687 struct packed_git *p, **pp = &packed_git;
689 while (*pp) {
690 p = *pp;
691 if (strcmp(pack_name, p->pack_name) == 0) {
692 close_pack_windows(p);
693 if (p->pack_fd != -1)
694 close(p->pack_fd);
695 if (p->index_data)
696 munmap((void *)p->index_data, p->index_size);
697 free(p->bad_object_sha1);
698 *pp = p->next;
699 free(p);
700 return;
702 pp = &p->next;
707 * Do not call this directly as this leaks p->pack_fd on error return;
708 * call open_packed_git() instead.
710 static int open_packed_git_1(struct packed_git *p)
712 struct stat st;
713 struct pack_header hdr;
714 unsigned char sha1[20];
715 unsigned char *idx_sha1;
716 long fd_flag;
718 if (!p->index_data && open_pack_index(p))
719 return error("packfile %s index unavailable", p->pack_name);
721 p->pack_fd = open(p->pack_name, O_RDONLY);
722 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
723 return -1;
725 /* If we created the struct before we had the pack we lack size. */
726 if (!p->pack_size) {
727 if (!S_ISREG(st.st_mode))
728 return error("packfile %s not a regular file", p->pack_name);
729 p->pack_size = st.st_size;
730 } else if (p->pack_size != st.st_size)
731 return error("packfile %s size changed", p->pack_name);
733 /* We leave these file descriptors open with sliding mmap;
734 * there is no point keeping them open across exec(), though.
736 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
737 if (fd_flag < 0)
738 return error("cannot determine file descriptor flags");
739 fd_flag |= FD_CLOEXEC;
740 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
741 return error("cannot set FD_CLOEXEC");
743 /* Verify we recognize this pack file format. */
744 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
745 return error("file %s is far too short to be a packfile", p->pack_name);
746 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
747 return error("file %s is not a GIT packfile", p->pack_name);
748 if (!pack_version_ok(hdr.hdr_version))
749 return error("packfile %s is version %"PRIu32" and not"
750 " supported (try upgrading GIT to a newer version)",
751 p->pack_name, ntohl(hdr.hdr_version));
753 /* Verify the pack matches its index. */
754 if (p->num_objects != ntohl(hdr.hdr_entries))
755 return error("packfile %s claims to have %"PRIu32" objects"
756 " while index indicates %"PRIu32" objects",
757 p->pack_name, ntohl(hdr.hdr_entries),
758 p->num_objects);
759 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
760 return error("end of packfile %s is unavailable", p->pack_name);
761 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
762 return error("packfile %s signature is unavailable", p->pack_name);
763 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
764 if (hashcmp(sha1, idx_sha1))
765 return error("packfile %s does not match index", p->pack_name);
766 return 0;
769 static int open_packed_git(struct packed_git *p)
771 if (!open_packed_git_1(p))
772 return 0;
773 if (p->pack_fd != -1) {
774 close(p->pack_fd);
775 p->pack_fd = -1;
777 return -1;
780 static int in_window(struct pack_window *win, off_t offset)
782 /* We must promise at least 20 bytes (one hash) after the
783 * offset is available from this window, otherwise the offset
784 * is not actually in this window and a different window (which
785 * has that one hash excess) must be used. This is to support
786 * the object header and delta base parsing routines below.
788 off_t win_off = win->offset;
789 return win_off <= offset
790 && (offset + 20) <= (win_off + win->len);
793 unsigned char* use_pack(struct packed_git *p,
794 struct pack_window **w_cursor,
795 off_t offset,
796 unsigned int *left)
798 struct pack_window *win = *w_cursor;
800 if (p->pack_fd == -1 && open_packed_git(p))
801 die("packfile %s cannot be accessed", p->pack_name);
803 /* Since packfiles end in a hash of their content and its
804 * pointless to ask for an offset into the middle of that
805 * hash, and the in_window function above wouldn't match
806 * don't allow an offset too close to the end of the file.
808 if (offset > (p->pack_size - 20))
809 die("offset beyond end of packfile (truncated pack?)");
811 if (!win || !in_window(win, offset)) {
812 if (win)
813 win->inuse_cnt--;
814 for (win = p->windows; win; win = win->next) {
815 if (in_window(win, offset))
816 break;
818 if (!win) {
819 size_t window_align = packed_git_window_size / 2;
820 off_t len;
821 win = xcalloc(1, sizeof(*win));
822 win->offset = (offset / window_align) * window_align;
823 len = p->pack_size - win->offset;
824 if (len > packed_git_window_size)
825 len = packed_git_window_size;
826 win->len = (size_t)len;
827 pack_mapped += win->len;
828 while (packed_git_limit < pack_mapped
829 && unuse_one_window(p, p->pack_fd))
830 ; /* nothing */
831 win->base = xmmap(NULL, win->len,
832 PROT_READ, MAP_PRIVATE,
833 p->pack_fd, win->offset);
834 if (win->base == MAP_FAILED)
835 die("packfile %s cannot be mapped: %s",
836 p->pack_name,
837 strerror(errno));
838 pack_mmap_calls++;
839 pack_open_windows++;
840 if (pack_mapped > peak_pack_mapped)
841 peak_pack_mapped = pack_mapped;
842 if (pack_open_windows > peak_pack_open_windows)
843 peak_pack_open_windows = pack_open_windows;
844 win->next = p->windows;
845 p->windows = win;
848 if (win != *w_cursor) {
849 win->last_used = pack_used_ctr++;
850 win->inuse_cnt++;
851 *w_cursor = win;
853 offset -= win->offset;
854 if (left)
855 *left = win->len - xsize_t(offset);
856 return win->base + offset;
859 static struct packed_git *alloc_packed_git(int extra)
861 struct packed_git *p = xmalloc(sizeof(*p) + extra);
862 memset(p, 0, sizeof(*p));
863 p->pack_fd = -1;
864 return p;
867 struct packed_git *add_packed_git(const char *path, int path_len, int local)
869 struct stat st;
870 struct packed_git *p = alloc_packed_git(path_len + 2);
873 * Make sure a corresponding .pack file exists and that
874 * the index looks sane.
876 path_len -= strlen(".idx");
877 if (path_len < 1) {
878 free(p);
879 return NULL;
881 memcpy(p->pack_name, path, path_len);
883 strcpy(p->pack_name + path_len, ".keep");
884 if (!access(p->pack_name, F_OK))
885 p->pack_keep = 1;
887 strcpy(p->pack_name + path_len, ".pack");
888 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
889 free(p);
890 return NULL;
893 /* ok, it looks sane as far as we can check without
894 * actually mapping the pack file.
896 p->pack_size = st.st_size;
897 p->pack_local = local;
898 p->mtime = st.st_mtime;
899 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
900 hashclr(p->sha1);
901 return p;
904 struct packed_git *parse_pack_index(unsigned char *sha1)
906 const char *idx_path = sha1_pack_index_name(sha1);
907 const char *path = sha1_pack_name(sha1);
908 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
910 strcpy(p->pack_name, path);
911 hashcpy(p->sha1, sha1);
912 if (check_packed_git_idx(idx_path, p)) {
913 free(p);
914 return NULL;
917 return p;
920 void install_packed_git(struct packed_git *pack)
922 pack->next = packed_git;
923 packed_git = pack;
926 static void prepare_packed_git_one(char *objdir, int local)
928 /* Ensure that this buffer is large enough so that we can
929 append "/pack/" without clobbering the stack even if
930 strlen(objdir) were PATH_MAX. */
931 char path[PATH_MAX + 1 + 4 + 1 + 1];
932 int len;
933 DIR *dir;
934 struct dirent *de;
936 sprintf(path, "%s/pack", objdir);
937 len = strlen(path);
938 dir = opendir(path);
939 if (!dir) {
940 if (errno != ENOENT)
941 error("unable to open object pack directory: %s: %s",
942 path, strerror(errno));
943 return;
945 path[len++] = '/';
946 while ((de = readdir(dir)) != NULL) {
947 int namelen = strlen(de->d_name);
948 struct packed_git *p;
950 if (!has_extension(de->d_name, ".idx"))
951 continue;
953 if (len + namelen + 1 > sizeof(path))
954 continue;
956 /* Don't reopen a pack we already have. */
957 strcpy(path + len, de->d_name);
958 for (p = packed_git; p; p = p->next) {
959 if (!memcmp(path, p->pack_name, len + namelen - 4))
960 break;
962 if (p)
963 continue;
964 /* See if it really is a valid .idx file with corresponding
965 * .pack file that we can map.
967 p = add_packed_git(path, len + namelen, local);
968 if (!p)
969 continue;
970 install_packed_git(p);
972 closedir(dir);
975 static int sort_pack(const void *a_, const void *b_)
977 struct packed_git *a = *((struct packed_git **)a_);
978 struct packed_git *b = *((struct packed_git **)b_);
979 int st;
982 * Local packs tend to contain objects specific to our
983 * variant of the project than remote ones. In addition,
984 * remote ones could be on a network mounted filesystem.
985 * Favor local ones for these reasons.
987 st = a->pack_local - b->pack_local;
988 if (st)
989 return -st;
992 * Younger packs tend to contain more recent objects,
993 * and more recent objects tend to get accessed more
994 * often.
996 if (a->mtime < b->mtime)
997 return 1;
998 else if (a->mtime == b->mtime)
999 return 0;
1000 return -1;
1003 static void rearrange_packed_git(void)
1005 struct packed_git **ary, *p;
1006 int i, n;
1008 for (n = 0, p = packed_git; p; p = p->next)
1009 n++;
1010 if (n < 2)
1011 return;
1013 /* prepare an array of packed_git for easier sorting */
1014 ary = xcalloc(n, sizeof(struct packed_git *));
1015 for (n = 0, p = packed_git; p; p = p->next)
1016 ary[n++] = p;
1018 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
1020 /* link them back again */
1021 for (i = 0; i < n - 1; i++)
1022 ary[i]->next = ary[i + 1];
1023 ary[n - 1]->next = NULL;
1024 packed_git = ary[0];
1026 free(ary);
1029 static int prepare_packed_git_run_once = 0;
1030 void prepare_packed_git(void)
1032 struct alternate_object_database *alt;
1034 if (prepare_packed_git_run_once)
1035 return;
1036 prepare_packed_git_one(get_object_directory(), 1);
1037 prepare_alt_odb();
1038 for (alt = alt_odb_list; alt; alt = alt->next) {
1039 alt->name[-1] = 0;
1040 prepare_packed_git_one(alt->base, 0);
1041 alt->name[-1] = '/';
1043 rearrange_packed_git();
1044 prepare_packed_git_run_once = 1;
1047 void reprepare_packed_git(void)
1049 discard_revindex();
1050 prepare_packed_git_run_once = 0;
1051 prepare_packed_git();
1054 static void mark_bad_packed_object(struct packed_git *p,
1055 const unsigned char *sha1)
1057 unsigned i;
1058 for (i = 0; i < p->num_bad_objects; i++)
1059 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1060 return;
1061 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1062 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1063 p->num_bad_objects++;
1066 static int has_packed_and_bad(const unsigned char *sha1)
1068 struct packed_git *p;
1069 unsigned i;
1071 for (p = packed_git; p; p = p->next)
1072 for (i = 0; i < p->num_bad_objects; i++)
1073 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1074 return 1;
1075 return 0;
1078 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
1080 unsigned char real_sha1[20];
1081 hash_sha1_file(map, size, type, real_sha1);
1082 return hashcmp(sha1, real_sha1) ? -1 : 0;
1085 static int git_open_noatime(const char *name)
1087 static int sha1_file_open_flag = O_NOATIME;
1088 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1090 /* Might the failure be due to O_NOATIME? */
1091 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1092 fd = open(name, O_RDONLY);
1093 if (fd >= 0)
1094 sha1_file_open_flag = 0;
1096 return fd;
1099 static int open_sha1_file(const unsigned char *sha1)
1101 int fd;
1102 char *name = sha1_file_name(sha1);
1103 struct alternate_object_database *alt;
1105 fd = git_open_noatime(name);
1106 if (fd >= 0)
1107 return fd;
1109 prepare_alt_odb();
1110 errno = ENOENT;
1111 for (alt = alt_odb_list; alt; alt = alt->next) {
1112 name = alt->name;
1113 fill_sha1_path(name, sha1);
1114 fd = git_open_noatime(alt->base);
1115 if (fd >= 0)
1116 return fd;
1118 return -1;
1121 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1123 void *map;
1124 int fd;
1126 fd = open_sha1_file(sha1);
1127 map = NULL;
1128 if (fd >= 0) {
1129 struct stat st;
1131 if (!fstat(fd, &st)) {
1132 *size = xsize_t(st.st_size);
1133 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1135 close(fd);
1137 return map;
1140 static int legacy_loose_object(unsigned char *map)
1142 unsigned int word;
1145 * Is it a zlib-compressed buffer? If so, the first byte
1146 * must be 0x78 (15-bit window size, deflated), and the
1147 * first 16-bit word is evenly divisible by 31
1149 word = (map[0] << 8) + map[1];
1150 if (map[0] == 0x78 && !(word % 31))
1151 return 1;
1152 else
1153 return 0;
1156 unsigned long unpack_object_header_buffer(const unsigned char *buf,
1157 unsigned long len, enum object_type *type, unsigned long *sizep)
1159 unsigned shift;
1160 unsigned char c;
1161 unsigned long size;
1162 unsigned long used = 0;
1164 c = buf[used++];
1165 *type = (c >> 4) & 7;
1166 size = c & 15;
1167 shift = 4;
1168 while (c & 0x80) {
1169 if (len <= used || sizeof(long) * 8 <= shift) {
1170 error("bad object header");
1171 return 0;
1173 c = buf[used++];
1174 size += (c & 0x7f) << shift;
1175 shift += 7;
1177 *sizep = size;
1178 return used;
1181 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1183 unsigned long size, used;
1184 static const char valid_loose_object_type[8] = {
1185 0, /* OBJ_EXT */
1186 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1187 0, /* "delta" and others are invalid in a loose object */
1189 enum object_type type;
1191 /* Get the data stream */
1192 memset(stream, 0, sizeof(*stream));
1193 stream->next_in = map;
1194 stream->avail_in = mapsize;
1195 stream->next_out = buffer;
1196 stream->avail_out = bufsiz;
1198 if (legacy_loose_object(map)) {
1199 git_inflate_init(stream);
1200 return git_inflate(stream, 0);
1205 * There used to be a second loose object header format which
1206 * was meant to mimic the in-pack format, allowing for direct
1207 * copy of the object data. This format turned up not to be
1208 * really worth it and we don't write it any longer. But we
1209 * can still read it.
1211 used = unpack_object_header_buffer(map, mapsize, &type, &size);
1212 if (!used || !valid_loose_object_type[type])
1213 return -1;
1214 map += used;
1215 mapsize -= used;
1217 /* Set up the stream for the rest.. */
1218 stream->next_in = map;
1219 stream->avail_in = mapsize;
1220 git_inflate_init(stream);
1222 /* And generate the fake traditional header */
1223 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1224 typename(type), size);
1225 return 0;
1228 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1230 int bytes = strlen(buffer) + 1;
1231 unsigned char *buf = xmalloc(1+size);
1232 unsigned long n;
1233 int status = Z_OK;
1235 n = stream->total_out - bytes;
1236 if (n > size)
1237 n = size;
1238 memcpy(buf, (char *) buffer + bytes, n);
1239 bytes = n;
1240 if (bytes <= size) {
1242 * The above condition must be (bytes <= size), not
1243 * (bytes < size). In other words, even though we
1244 * expect no more output and set avail_out to zer0,
1245 * the input zlib stream may have bytes that express
1246 * "this concludes the stream", and we *do* want to
1247 * eat that input.
1249 * Otherwise we would not be able to test that we
1250 * consumed all the input to reach the expected size;
1251 * we also want to check that zlib tells us that all
1252 * went well with status == Z_STREAM_END at the end.
1254 stream->next_out = buf + bytes;
1255 stream->avail_out = size - bytes;
1256 while (status == Z_OK)
1257 status = git_inflate(stream, Z_FINISH);
1259 buf[size] = 0;
1260 if (status == Z_STREAM_END && !stream->avail_in) {
1261 git_inflate_end(stream);
1262 return buf;
1265 if (status < 0)
1266 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1267 else if (stream->avail_in)
1268 error("garbage at end of loose object '%s'",
1269 sha1_to_hex(sha1));
1270 free(buf);
1271 return NULL;
1275 * We used to just use "sscanf()", but that's actually way
1276 * too permissive for what we want to check. So do an anal
1277 * object header parse by hand.
1279 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1281 char type[10];
1282 int i;
1283 unsigned long size;
1286 * The type can be at most ten bytes (including the
1287 * terminating '\0' that we add), and is followed by
1288 * a space.
1290 i = 0;
1291 for (;;) {
1292 char c = *hdr++;
1293 if (c == ' ')
1294 break;
1295 type[i++] = c;
1296 if (i >= sizeof(type))
1297 return -1;
1299 type[i] = 0;
1302 * The length must follow immediately, and be in canonical
1303 * decimal format (ie "010" is not valid).
1305 size = *hdr++ - '0';
1306 if (size > 9)
1307 return -1;
1308 if (size) {
1309 for (;;) {
1310 unsigned long c = *hdr - '0';
1311 if (c > 9)
1312 break;
1313 hdr++;
1314 size = size * 10 + c;
1317 *sizep = size;
1320 * The length must be followed by a zero byte
1322 return *hdr ? -1 : type_from_string(type);
1325 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1327 int ret;
1328 z_stream stream;
1329 char hdr[8192];
1331 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1332 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1333 return NULL;
1335 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1338 unsigned long get_size_from_delta(struct packed_git *p,
1339 struct pack_window **w_curs,
1340 off_t curpos)
1342 const unsigned char *data;
1343 unsigned char delta_head[20], *in;
1344 z_stream stream;
1345 int st;
1347 memset(&stream, 0, sizeof(stream));
1348 stream.next_out = delta_head;
1349 stream.avail_out = sizeof(delta_head);
1351 git_inflate_init(&stream);
1352 do {
1353 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1354 stream.next_in = in;
1355 st = git_inflate(&stream, Z_FINISH);
1356 curpos += stream.next_in - in;
1357 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1358 stream.total_out < sizeof(delta_head));
1359 git_inflate_end(&stream);
1360 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1361 error("delta data unpack-initial failed");
1362 return 0;
1365 /* Examine the initial part of the delta to figure out
1366 * the result size.
1368 data = delta_head;
1370 /* ignore base size */
1371 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1373 /* Read the result size */
1374 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1377 static off_t get_delta_base(struct packed_git *p,
1378 struct pack_window **w_curs,
1379 off_t *curpos,
1380 enum object_type type,
1381 off_t delta_obj_offset)
1383 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1384 off_t base_offset;
1386 /* use_pack() assured us we have [base_info, base_info + 20)
1387 * as a range that we can look at without walking off the
1388 * end of the mapped window. Its actually the hash size
1389 * that is assured. An OFS_DELTA longer than the hash size
1390 * is stupid, as then a REF_DELTA would be smaller to store.
1392 if (type == OBJ_OFS_DELTA) {
1393 unsigned used = 0;
1394 unsigned char c = base_info[used++];
1395 base_offset = c & 127;
1396 while (c & 128) {
1397 base_offset += 1;
1398 if (!base_offset || MSB(base_offset, 7))
1399 return 0; /* overflow */
1400 c = base_info[used++];
1401 base_offset = (base_offset << 7) + (c & 127);
1403 base_offset = delta_obj_offset - base_offset;
1404 if (base_offset <= 0 || base_offset >= delta_obj_offset)
1405 return 0; /* out of bound */
1406 *curpos += used;
1407 } else if (type == OBJ_REF_DELTA) {
1408 /* The base entry _must_ be in the same pack */
1409 base_offset = find_pack_entry_one(base_info, p);
1410 *curpos += 20;
1411 } else
1412 die("I am totally screwed");
1413 return base_offset;
1416 /* forward declaration for a mutually recursive function */
1417 static int packed_object_info(struct packed_git *p, off_t offset,
1418 unsigned long *sizep);
1420 static int packed_delta_info(struct packed_git *p,
1421 struct pack_window **w_curs,
1422 off_t curpos,
1423 enum object_type type,
1424 off_t obj_offset,
1425 unsigned long *sizep)
1427 off_t base_offset;
1429 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1430 if (!base_offset)
1431 return OBJ_BAD;
1432 type = packed_object_info(p, base_offset, NULL);
1433 if (type <= OBJ_NONE) {
1434 struct revindex_entry *revidx;
1435 const unsigned char *base_sha1;
1436 revidx = find_pack_revindex(p, base_offset);
1437 if (!revidx)
1438 return OBJ_BAD;
1439 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1440 mark_bad_packed_object(p, base_sha1);
1441 type = sha1_object_info(base_sha1, NULL);
1442 if (type <= OBJ_NONE)
1443 return OBJ_BAD;
1446 /* We choose to only get the type of the base object and
1447 * ignore potentially corrupt pack file that expects the delta
1448 * based on a base with a wrong size. This saves tons of
1449 * inflate() calls.
1451 if (sizep) {
1452 *sizep = get_size_from_delta(p, w_curs, curpos);
1453 if (*sizep == 0)
1454 type = OBJ_BAD;
1457 return type;
1460 static int unpack_object_header(struct packed_git *p,
1461 struct pack_window **w_curs,
1462 off_t *curpos,
1463 unsigned long *sizep)
1465 unsigned char *base;
1466 unsigned int left;
1467 unsigned long used;
1468 enum object_type type;
1470 /* use_pack() assures us we have [base, base + 20) available
1471 * as a range that we can look at at. (Its actually the hash
1472 * size that is assured.) With our object header encoding
1473 * the maximum deflated object size is 2^137, which is just
1474 * insane, so we know won't exceed what we have been given.
1476 base = use_pack(p, w_curs, *curpos, &left);
1477 used = unpack_object_header_buffer(base, left, &type, sizep);
1478 if (!used) {
1479 type = OBJ_BAD;
1480 } else
1481 *curpos += used;
1483 return type;
1486 const char *packed_object_info_detail(struct packed_git *p,
1487 off_t obj_offset,
1488 unsigned long *size,
1489 unsigned long *store_size,
1490 unsigned int *delta_chain_length,
1491 unsigned char *base_sha1)
1493 struct pack_window *w_curs = NULL;
1494 off_t curpos;
1495 unsigned long dummy;
1496 unsigned char *next_sha1;
1497 enum object_type type;
1498 struct revindex_entry *revidx;
1500 *delta_chain_length = 0;
1501 curpos = obj_offset;
1502 type = unpack_object_header(p, &w_curs, &curpos, size);
1504 revidx = find_pack_revindex(p, obj_offset);
1505 *store_size = revidx[1].offset - obj_offset;
1507 for (;;) {
1508 switch (type) {
1509 default:
1510 die("pack %s contains unknown object type %d",
1511 p->pack_name, type);
1512 case OBJ_COMMIT:
1513 case OBJ_TREE:
1514 case OBJ_BLOB:
1515 case OBJ_TAG:
1516 unuse_pack(&w_curs);
1517 return typename(type);
1518 case OBJ_OFS_DELTA:
1519 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1520 if (!obj_offset)
1521 die("pack %s contains bad delta base reference of type %s",
1522 p->pack_name, typename(type));
1523 if (*delta_chain_length == 0) {
1524 revidx = find_pack_revindex(p, obj_offset);
1525 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
1527 break;
1528 case OBJ_REF_DELTA:
1529 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1530 if (*delta_chain_length == 0)
1531 hashcpy(base_sha1, next_sha1);
1532 obj_offset = find_pack_entry_one(next_sha1, p);
1533 break;
1535 (*delta_chain_length)++;
1536 curpos = obj_offset;
1537 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1541 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1542 unsigned long *sizep)
1544 struct pack_window *w_curs = NULL;
1545 unsigned long size;
1546 off_t curpos = obj_offset;
1547 enum object_type type;
1549 type = unpack_object_header(p, &w_curs, &curpos, &size);
1551 switch (type) {
1552 case OBJ_OFS_DELTA:
1553 case OBJ_REF_DELTA:
1554 type = packed_delta_info(p, &w_curs, curpos,
1555 type, obj_offset, sizep);
1556 break;
1557 case OBJ_COMMIT:
1558 case OBJ_TREE:
1559 case OBJ_BLOB:
1560 case OBJ_TAG:
1561 if (sizep)
1562 *sizep = size;
1563 break;
1564 default:
1565 error("unknown object type %i at offset %"PRIuMAX" in %s",
1566 type, (uintmax_t)obj_offset, p->pack_name);
1567 type = OBJ_BAD;
1569 unuse_pack(&w_curs);
1570 return type;
1573 static void *unpack_compressed_entry(struct packed_git *p,
1574 struct pack_window **w_curs,
1575 off_t curpos,
1576 unsigned long size)
1578 int st;
1579 z_stream stream;
1580 unsigned char *buffer, *in;
1582 buffer = xmalloc(size + 1);
1583 buffer[size] = 0;
1584 memset(&stream, 0, sizeof(stream));
1585 stream.next_out = buffer;
1586 stream.avail_out = size;
1588 git_inflate_init(&stream);
1589 do {
1590 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1591 stream.next_in = in;
1592 st = git_inflate(&stream, Z_FINISH);
1593 curpos += stream.next_in - in;
1594 } while (st == Z_OK || st == Z_BUF_ERROR);
1595 git_inflate_end(&stream);
1596 if ((st != Z_STREAM_END) || stream.total_out != size) {
1597 free(buffer);
1598 return NULL;
1601 return buffer;
1604 #define MAX_DELTA_CACHE (256)
1606 static size_t delta_base_cached;
1608 static struct delta_base_cache_lru_list {
1609 struct delta_base_cache_lru_list *prev;
1610 struct delta_base_cache_lru_list *next;
1611 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1613 static struct delta_base_cache_entry {
1614 struct delta_base_cache_lru_list lru;
1615 void *data;
1616 struct packed_git *p;
1617 off_t base_offset;
1618 unsigned long size;
1619 enum object_type type;
1620 } delta_base_cache[MAX_DELTA_CACHE];
1622 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1624 unsigned long hash;
1626 hash = (unsigned long)p + (unsigned long)base_offset;
1627 hash += (hash >> 8) + (hash >> 16);
1628 return hash % MAX_DELTA_CACHE;
1631 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1632 unsigned long *base_size, enum object_type *type, int keep_cache)
1634 void *ret;
1635 unsigned long hash = pack_entry_hash(p, base_offset);
1636 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1638 ret = ent->data;
1639 if (!ret || ent->p != p || ent->base_offset != base_offset)
1640 return unpack_entry(p, base_offset, type, base_size);
1642 if (!keep_cache) {
1643 ent->data = NULL;
1644 ent->lru.next->prev = ent->lru.prev;
1645 ent->lru.prev->next = ent->lru.next;
1646 delta_base_cached -= ent->size;
1647 } else {
1648 ret = xmemdupz(ent->data, ent->size);
1650 *type = ent->type;
1651 *base_size = ent->size;
1652 return ret;
1655 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1657 if (ent->data) {
1658 free(ent->data);
1659 ent->data = NULL;
1660 ent->lru.next->prev = ent->lru.prev;
1661 ent->lru.prev->next = ent->lru.next;
1662 delta_base_cached -= ent->size;
1666 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1667 void *base, unsigned long base_size, enum object_type type)
1669 unsigned long hash = pack_entry_hash(p, base_offset);
1670 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1671 struct delta_base_cache_lru_list *lru;
1673 release_delta_base_cache(ent);
1674 delta_base_cached += base_size;
1676 for (lru = delta_base_cache_lru.next;
1677 delta_base_cached > delta_base_cache_limit
1678 && lru != &delta_base_cache_lru;
1679 lru = lru->next) {
1680 struct delta_base_cache_entry *f = (void *)lru;
1681 if (f->type == OBJ_BLOB)
1682 release_delta_base_cache(f);
1684 for (lru = delta_base_cache_lru.next;
1685 delta_base_cached > delta_base_cache_limit
1686 && lru != &delta_base_cache_lru;
1687 lru = lru->next) {
1688 struct delta_base_cache_entry *f = (void *)lru;
1689 release_delta_base_cache(f);
1692 ent->p = p;
1693 ent->base_offset = base_offset;
1694 ent->type = type;
1695 ent->data = base;
1696 ent->size = base_size;
1697 ent->lru.next = &delta_base_cache_lru;
1698 ent->lru.prev = delta_base_cache_lru.prev;
1699 delta_base_cache_lru.prev->next = &ent->lru;
1700 delta_base_cache_lru.prev = &ent->lru;
1703 static void *read_object(const unsigned char *sha1, enum object_type *type,
1704 unsigned long *size);
1706 static void *unpack_delta_entry(struct packed_git *p,
1707 struct pack_window **w_curs,
1708 off_t curpos,
1709 unsigned long delta_size,
1710 off_t obj_offset,
1711 enum object_type *type,
1712 unsigned long *sizep)
1714 void *delta_data, *result, *base;
1715 unsigned long base_size;
1716 off_t base_offset;
1718 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
1719 if (!base_offset) {
1720 error("failed to validate delta base reference "
1721 "at offset %"PRIuMAX" from %s",
1722 (uintmax_t)curpos, p->pack_name);
1723 return NULL;
1725 unuse_pack(w_curs);
1726 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1727 if (!base) {
1729 * We're probably in deep shit, but let's try to fetch
1730 * the required base anyway from another pack or loose.
1731 * This is costly but should happen only in the presence
1732 * of a corrupted pack, and is better than failing outright.
1734 struct revindex_entry *revidx;
1735 const unsigned char *base_sha1;
1736 revidx = find_pack_revindex(p, base_offset);
1737 if (!revidx)
1738 return NULL;
1739 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
1740 error("failed to read delta base object %s"
1741 " at offset %"PRIuMAX" from %s",
1742 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1743 p->pack_name);
1744 mark_bad_packed_object(p, base_sha1);
1745 base = read_object(base_sha1, type, &base_size);
1746 if (!base)
1747 return NULL;
1750 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1751 if (!delta_data) {
1752 error("failed to unpack compressed delta "
1753 "at offset %"PRIuMAX" from %s",
1754 (uintmax_t)curpos, p->pack_name);
1755 free(base);
1756 return NULL;
1758 result = patch_delta(base, base_size,
1759 delta_data, delta_size,
1760 sizep);
1761 if (!result)
1762 die("failed to apply delta");
1763 free(delta_data);
1764 add_delta_base_cache(p, base_offset, base, base_size, *type);
1765 return result;
1768 int do_check_packed_object_crc;
1770 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1771 enum object_type *type, unsigned long *sizep)
1773 struct pack_window *w_curs = NULL;
1774 off_t curpos = obj_offset;
1775 void *data;
1777 if (do_check_packed_object_crc && p->index_version > 1) {
1778 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1779 unsigned long len = revidx[1].offset - obj_offset;
1780 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1781 const unsigned char *sha1 =
1782 nth_packed_object_sha1(p, revidx->nr);
1783 error("bad packed object CRC for %s",
1784 sha1_to_hex(sha1));
1785 mark_bad_packed_object(p, sha1);
1786 unuse_pack(&w_curs);
1787 return NULL;
1791 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1792 switch (*type) {
1793 case OBJ_OFS_DELTA:
1794 case OBJ_REF_DELTA:
1795 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1796 obj_offset, type, sizep);
1797 break;
1798 case OBJ_COMMIT:
1799 case OBJ_TREE:
1800 case OBJ_BLOB:
1801 case OBJ_TAG:
1802 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1803 break;
1804 default:
1805 data = NULL;
1806 error("unknown object type %i at offset %"PRIuMAX" in %s",
1807 *type, (uintmax_t)obj_offset, p->pack_name);
1809 unuse_pack(&w_curs);
1810 return data;
1813 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1814 uint32_t n)
1816 const unsigned char *index = p->index_data;
1817 if (!index) {
1818 if (open_pack_index(p))
1819 return NULL;
1820 index = p->index_data;
1822 if (n >= p->num_objects)
1823 return NULL;
1824 index += 4 * 256;
1825 if (p->index_version == 1) {
1826 return index + 24 * n + 4;
1827 } else {
1828 index += 8;
1829 return index + 20 * n;
1833 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1835 const unsigned char *index = p->index_data;
1836 index += 4 * 256;
1837 if (p->index_version == 1) {
1838 return ntohl(*((uint32_t *)(index + 24 * n)));
1839 } else {
1840 uint32_t off;
1841 index += 8 + p->num_objects * (20 + 4);
1842 off = ntohl(*((uint32_t *)(index + 4 * n)));
1843 if (!(off & 0x80000000))
1844 return off;
1845 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1846 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1847 ntohl(*((uint32_t *)(index + 4)));
1851 off_t find_pack_entry_one(const unsigned char *sha1,
1852 struct packed_git *p)
1854 const uint32_t *level1_ofs = p->index_data;
1855 const unsigned char *index = p->index_data;
1856 unsigned hi, lo, stride;
1857 static int use_lookup = -1;
1858 static int debug_lookup = -1;
1860 if (debug_lookup < 0)
1861 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
1863 if (!index) {
1864 if (open_pack_index(p))
1865 return 0;
1866 level1_ofs = p->index_data;
1867 index = p->index_data;
1869 if (p->index_version > 1) {
1870 level1_ofs += 2;
1871 index += 8;
1873 index += 4 * 256;
1874 hi = ntohl(level1_ofs[*sha1]);
1875 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1876 if (p->index_version > 1) {
1877 stride = 20;
1878 } else {
1879 stride = 24;
1880 index += 4;
1883 if (debug_lookup)
1884 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
1885 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1887 if (use_lookup < 0)
1888 use_lookup = !!getenv("GIT_USE_LOOKUP");
1889 if (use_lookup) {
1890 int pos = sha1_entry_pos(index, stride, 0,
1891 lo, hi, p->num_objects, sha1);
1892 if (pos < 0)
1893 return 0;
1894 return nth_packed_object_offset(p, pos);
1897 do {
1898 unsigned mi = (lo + hi) / 2;
1899 int cmp = hashcmp(index + mi * stride, sha1);
1901 if (debug_lookup)
1902 printf("lo %u hi %u rg %u mi %u\n",
1903 lo, hi, hi - lo, mi);
1904 if (!cmp)
1905 return nth_packed_object_offset(p, mi);
1906 if (cmp > 0)
1907 hi = mi;
1908 else
1909 lo = mi+1;
1910 } while (lo < hi);
1911 return 0;
1914 int matches_pack_name(struct packed_git *p, const char *name)
1916 const char *last_c, *c;
1918 if (!strcmp(p->pack_name, name))
1919 return 1;
1921 for (c = p->pack_name, last_c = c; *c;)
1922 if (*c == '/')
1923 last_c = ++c;
1924 else
1925 ++c;
1926 if (!strcmp(last_c, name))
1927 return 1;
1929 return 0;
1932 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1934 static struct packed_git *last_found = (void *)1;
1935 struct packed_git *p;
1936 off_t offset;
1938 prepare_packed_git();
1939 if (!packed_git)
1940 return 0;
1941 p = (last_found == (void *)1) ? packed_git : last_found;
1943 do {
1944 if (ignore_packed) {
1945 const char **ig;
1946 for (ig = ignore_packed; *ig; ig++)
1947 if (matches_pack_name(p, *ig))
1948 break;
1949 if (*ig)
1950 goto next;
1953 if (p->num_bad_objects) {
1954 unsigned i;
1955 for (i = 0; i < p->num_bad_objects; i++)
1956 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1957 goto next;
1960 offset = find_pack_entry_one(sha1, p);
1961 if (offset) {
1963 * We are about to tell the caller where they can
1964 * locate the requested object. We better make
1965 * sure the packfile is still here and can be
1966 * accessed before supplying that answer, as
1967 * it may have been deleted since the index
1968 * was loaded!
1970 if (p->pack_fd == -1 && open_packed_git(p)) {
1971 error("packfile %s cannot be accessed", p->pack_name);
1972 goto next;
1974 e->offset = offset;
1975 e->p = p;
1976 hashcpy(e->sha1, sha1);
1977 last_found = p;
1978 return 1;
1981 next:
1982 if (p == last_found)
1983 p = packed_git;
1984 else
1985 p = p->next;
1986 if (p == last_found)
1987 p = p->next;
1988 } while (p);
1989 return 0;
1992 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1993 struct packed_git *packs)
1995 struct packed_git *p;
1997 for (p = packs; p; p = p->next) {
1998 if (find_pack_entry_one(sha1, p))
1999 return p;
2001 return NULL;
2005 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
2007 int status;
2008 unsigned long mapsize, size;
2009 void *map;
2010 z_stream stream;
2011 char hdr[32];
2013 map = map_sha1_file(sha1, &mapsize);
2014 if (!map)
2015 return error("unable to find %s", sha1_to_hex(sha1));
2016 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
2017 status = error("unable to unpack %s header",
2018 sha1_to_hex(sha1));
2019 else if ((status = parse_sha1_header(hdr, &size)) < 0)
2020 status = error("unable to parse %s header", sha1_to_hex(sha1));
2021 else if (sizep)
2022 *sizep = size;
2023 git_inflate_end(&stream);
2024 munmap(map, mapsize);
2025 return status;
2028 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
2030 struct pack_entry e;
2031 int status;
2033 if (!find_pack_entry(sha1, &e, NULL)) {
2034 /* Most likely it's a loose object. */
2035 status = sha1_loose_object_info(sha1, sizep);
2036 if (status >= 0)
2037 return status;
2039 /* Not a loose object; someone else may have just packed it. */
2040 reprepare_packed_git();
2041 if (!find_pack_entry(sha1, &e, NULL))
2042 return status;
2045 status = packed_object_info(e.p, e.offset, sizep);
2046 if (status < 0) {
2047 mark_bad_packed_object(e.p, sha1);
2048 status = sha1_object_info(sha1, sizep);
2051 return status;
2054 static void *read_packed_sha1(const unsigned char *sha1,
2055 enum object_type *type, unsigned long *size)
2057 struct pack_entry e;
2058 void *data;
2060 if (!find_pack_entry(sha1, &e, NULL))
2061 return NULL;
2062 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
2063 if (!data) {
2065 * We're probably in deep shit, but let's try to fetch
2066 * the required object anyway from another pack or loose.
2067 * This should happen only in the presence of a corrupted
2068 * pack, and is better than failing outright.
2070 error("failed to read object %s at offset %"PRIuMAX" from %s",
2071 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
2072 mark_bad_packed_object(e.p, sha1);
2073 data = read_object(sha1, type, size);
2075 return data;
2079 * This is meant to hold a *small* number of objects that you would
2080 * want read_sha1_file() to be able to return, but yet you do not want
2081 * to write them into the object store (e.g. a browse-only
2082 * application).
2084 static struct cached_object {
2085 unsigned char sha1[20];
2086 enum object_type type;
2087 void *buf;
2088 unsigned long size;
2089 } *cached_objects;
2090 static int cached_object_nr, cached_object_alloc;
2092 static struct cached_object empty_tree = {
2093 EMPTY_TREE_SHA1_BIN,
2094 OBJ_TREE,
2099 static struct cached_object *find_cached_object(const unsigned char *sha1)
2101 int i;
2102 struct cached_object *co = cached_objects;
2104 for (i = 0; i < cached_object_nr; i++, co++) {
2105 if (!hashcmp(co->sha1, sha1))
2106 return co;
2108 if (!hashcmp(sha1, empty_tree.sha1))
2109 return &empty_tree;
2110 return NULL;
2113 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2114 unsigned char *sha1)
2116 struct cached_object *co;
2118 hash_sha1_file(buf, len, typename(type), sha1);
2119 if (has_sha1_file(sha1) || find_cached_object(sha1))
2120 return 0;
2121 if (cached_object_alloc <= cached_object_nr) {
2122 cached_object_alloc = alloc_nr(cached_object_alloc);
2123 cached_objects = xrealloc(cached_objects,
2124 sizeof(*cached_objects) *
2125 cached_object_alloc);
2127 co = &cached_objects[cached_object_nr++];
2128 co->size = len;
2129 co->type = type;
2130 co->buf = xmalloc(len);
2131 memcpy(co->buf, buf, len);
2132 hashcpy(co->sha1, sha1);
2133 return 0;
2136 static void *read_object(const unsigned char *sha1, enum object_type *type,
2137 unsigned long *size)
2139 unsigned long mapsize;
2140 void *map, *buf;
2141 struct cached_object *co;
2143 co = find_cached_object(sha1);
2144 if (co) {
2145 *type = co->type;
2146 *size = co->size;
2147 return xmemdupz(co->buf, co->size);
2150 buf = read_packed_sha1(sha1, type, size);
2151 if (buf)
2152 return buf;
2153 map = map_sha1_file(sha1, &mapsize);
2154 if (map) {
2155 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2156 munmap(map, mapsize);
2157 return buf;
2159 reprepare_packed_git();
2160 return read_packed_sha1(sha1, type, size);
2163 void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
2164 unsigned long *size)
2166 void *data = read_object(sha1, type, size);
2167 /* legacy behavior is to die on corrupted objects */
2168 if (!data && (has_loose_object(sha1) || has_packed_and_bad(sha1)))
2169 die("object %s is corrupted", sha1_to_hex(sha1));
2170 return data;
2173 void *read_object_with_reference(const unsigned char *sha1,
2174 const char *required_type_name,
2175 unsigned long *size,
2176 unsigned char *actual_sha1_return)
2178 enum object_type type, required_type;
2179 void *buffer;
2180 unsigned long isize;
2181 unsigned char actual_sha1[20];
2183 required_type = type_from_string(required_type_name);
2184 hashcpy(actual_sha1, sha1);
2185 while (1) {
2186 int ref_length = -1;
2187 const char *ref_type = NULL;
2189 buffer = read_sha1_file(actual_sha1, &type, &isize);
2190 if (!buffer)
2191 return NULL;
2192 if (type == required_type) {
2193 *size = isize;
2194 if (actual_sha1_return)
2195 hashcpy(actual_sha1_return, actual_sha1);
2196 return buffer;
2198 /* Handle references */
2199 else if (type == OBJ_COMMIT)
2200 ref_type = "tree ";
2201 else if (type == OBJ_TAG)
2202 ref_type = "object ";
2203 else {
2204 free(buffer);
2205 return NULL;
2207 ref_length = strlen(ref_type);
2209 if (ref_length + 40 > isize ||
2210 memcmp(buffer, ref_type, ref_length) ||
2211 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2212 free(buffer);
2213 return NULL;
2215 free(buffer);
2216 /* Now we have the ID of the referred-to object in
2217 * actual_sha1. Check again. */
2221 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2222 const char *type, unsigned char *sha1,
2223 char *hdr, int *hdrlen)
2225 git_SHA_CTX c;
2227 /* Generate the header */
2228 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2230 /* Sha1.. */
2231 git_SHA1_Init(&c);
2232 git_SHA1_Update(&c, hdr, *hdrlen);
2233 git_SHA1_Update(&c, buf, len);
2234 git_SHA1_Final(sha1, &c);
2238 * Move the just written object into its final resting place
2240 int move_temp_to_file(const char *tmpfile, const char *filename)
2242 int ret = 0;
2243 if (link(tmpfile, filename))
2244 ret = errno;
2247 * Coda hack - coda doesn't like cross-directory links,
2248 * so we fall back to a rename, which will mean that it
2249 * won't be able to check collisions, but that's not a
2250 * big deal.
2252 * The same holds for FAT formatted media.
2254 * When this succeeds, we just return 0. We have nothing
2255 * left to unlink.
2257 if (ret && ret != EEXIST) {
2258 if (!rename(tmpfile, filename))
2259 return 0;
2260 ret = errno;
2262 unlink(tmpfile);
2263 if (ret) {
2264 if (ret != EEXIST) {
2265 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
2267 /* FIXME!!! Collision check here ? */
2270 return 0;
2273 static int write_buffer(int fd, const void *buf, size_t len)
2275 if (write_in_full(fd, buf, len) < 0)
2276 return error("file write error (%s)", strerror(errno));
2277 return 0;
2280 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2281 unsigned char *sha1)
2283 char hdr[32];
2284 int hdrlen;
2285 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2286 return 0;
2289 /* Finalize a file on disk, and close it. */
2290 static void close_sha1_file(int fd)
2292 if (fsync_object_files)
2293 fsync_or_die(fd, "sha1 file");
2294 fchmod(fd, 0444);
2295 if (close(fd) != 0)
2296 die("unable to write sha1 file");
2299 /* Size of directory component, including the ending '/' */
2300 static inline int directory_size(const char *filename)
2302 const char *s = strrchr(filename, '/');
2303 if (!s)
2304 return 0;
2305 return s - filename + 1;
2309 * This creates a temporary file in the same directory as the final
2310 * 'filename'
2312 * We want to avoid cross-directory filename renames, because those
2313 * can have problems on various filesystems (FAT, NFS, Coda).
2315 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2317 int fd, dirlen = directory_size(filename);
2319 if (dirlen + 20 > bufsiz) {
2320 errno = ENAMETOOLONG;
2321 return -1;
2323 memcpy(buffer, filename, dirlen);
2324 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2325 fd = mkstemp(buffer);
2326 if (fd < 0 && dirlen && errno == ENOENT) {
2327 /* Make sure the directory exists */
2328 memcpy(buffer, filename, dirlen);
2329 buffer[dirlen-1] = 0;
2330 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2331 return -1;
2333 /* Try again */
2334 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2335 fd = mkstemp(buffer);
2337 return fd;
2340 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2341 void *buf, unsigned long len, time_t mtime)
2343 int fd, ret;
2344 size_t size;
2345 unsigned char *compressed;
2346 z_stream stream;
2347 char *filename;
2348 static char tmpfile[PATH_MAX];
2350 filename = sha1_file_name(sha1);
2351 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2352 if (fd < 0) {
2353 if (errno == EACCES)
2354 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2355 else
2356 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2359 /* Set it up */
2360 memset(&stream, 0, sizeof(stream));
2361 deflateInit(&stream, zlib_compression_level);
2362 size = 8 + deflateBound(&stream, len+hdrlen);
2363 compressed = xmalloc(size);
2365 /* Compress it */
2366 stream.next_out = compressed;
2367 stream.avail_out = size;
2369 /* First header.. */
2370 stream.next_in = (unsigned char *)hdr;
2371 stream.avail_in = hdrlen;
2372 while (deflate(&stream, 0) == Z_OK)
2373 /* nothing */;
2375 /* Then the data itself.. */
2376 stream.next_in = buf;
2377 stream.avail_in = len;
2378 ret = deflate(&stream, Z_FINISH);
2379 if (ret != Z_STREAM_END)
2380 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2382 ret = deflateEnd(&stream);
2383 if (ret != Z_OK)
2384 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2386 size = stream.total_out;
2388 if (write_buffer(fd, compressed, size) < 0)
2389 die("unable to write sha1 file");
2390 close_sha1_file(fd);
2391 free(compressed);
2393 if (mtime) {
2394 struct utimbuf utb;
2395 utb.actime = mtime;
2396 utb.modtime = mtime;
2397 if (utime(tmpfile, &utb) < 0)
2398 warning("failed utime() on %s: %s",
2399 tmpfile, strerror(errno));
2402 return move_temp_to_file(tmpfile, filename);
2405 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2407 unsigned char sha1[20];
2408 char hdr[32];
2409 int hdrlen;
2411 /* Normally if we have it in the pack then we do not bother writing
2412 * it out into .git/objects/??/?{38} file.
2414 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2415 if (returnsha1)
2416 hashcpy(returnsha1, sha1);
2417 if (has_sha1_file(sha1))
2418 return 0;
2419 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2422 int force_object_loose(const unsigned char *sha1, time_t mtime)
2424 void *buf;
2425 unsigned long len;
2426 enum object_type type;
2427 char hdr[32];
2428 int hdrlen;
2429 int ret;
2431 if (has_loose_object(sha1))
2432 return 0;
2433 buf = read_packed_sha1(sha1, &type, &len);
2434 if (!buf)
2435 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2436 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2437 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2438 free(buf);
2440 return ret;
2443 int has_pack_index(const unsigned char *sha1)
2445 struct stat st;
2446 if (stat(sha1_pack_index_name(sha1), &st))
2447 return 0;
2448 return 1;
2451 int has_pack_file(const unsigned char *sha1)
2453 struct stat st;
2454 if (stat(sha1_pack_name(sha1), &st))
2455 return 0;
2456 return 1;
2459 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
2461 struct pack_entry e;
2462 return find_pack_entry(sha1, &e, ignore_packed);
2465 int has_sha1_file(const unsigned char *sha1)
2467 struct pack_entry e;
2469 if (find_pack_entry(sha1, &e, NULL))
2470 return 1;
2471 return has_loose_object(sha1);
2474 static int index_mem(unsigned char *sha1, void *buf, size_t size,
2475 int write_object, enum object_type type, const char *path)
2477 int ret, re_allocated = 0;
2479 if (!type)
2480 type = OBJ_BLOB;
2483 * Convert blobs to git internal format
2485 if ((type == OBJ_BLOB) && path) {
2486 struct strbuf nbuf = STRBUF_INIT;
2487 if (convert_to_git(path, buf, size, &nbuf,
2488 write_object ? safe_crlf : 0)) {
2489 buf = strbuf_detach(&nbuf, &size);
2490 re_allocated = 1;
2494 if (write_object)
2495 ret = write_sha1_file(buf, size, typename(type), sha1);
2496 else
2497 ret = hash_sha1_file(buf, size, typename(type), sha1);
2498 if (re_allocated)
2499 free(buf);
2500 return ret;
2503 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2504 enum object_type type, const char *path)
2506 int ret;
2507 size_t size = xsize_t(st->st_size);
2509 if (!S_ISREG(st->st_mode)) {
2510 struct strbuf sbuf = STRBUF_INIT;
2511 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2512 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2513 type, path);
2514 else
2515 ret = -1;
2516 strbuf_release(&sbuf);
2517 } else if (size) {
2518 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2519 ret = index_mem(sha1, buf, size, write_object, type, path);
2520 munmap(buf, size);
2521 } else
2522 ret = index_mem(sha1, NULL, size, write_object, type, path);
2523 close(fd);
2524 return ret;
2527 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2529 int fd;
2530 struct strbuf sb = STRBUF_INIT;
2532 switch (st->st_mode & S_IFMT) {
2533 case S_IFREG:
2534 fd = open(path, O_RDONLY);
2535 if (fd < 0)
2536 return error("open(\"%s\"): %s", path,
2537 strerror(errno));
2538 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2539 return error("%s: failed to insert into database",
2540 path);
2541 break;
2542 case S_IFLNK:
2543 if (strbuf_readlink(&sb, path, st->st_size)) {
2544 char *errstr = strerror(errno);
2545 return error("readlink(\"%s\"): %s", path,
2546 errstr);
2548 if (!write_object)
2549 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2550 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
2551 return error("%s: failed to insert into database",
2552 path);
2553 strbuf_release(&sb);
2554 break;
2555 case S_IFDIR:
2556 return resolve_gitlink_ref(path, "HEAD", sha1);
2557 default:
2558 return error("%s: unsupported file type", path);
2560 return 0;
2563 int read_pack_header(int fd, struct pack_header *header)
2565 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2566 /* "eof before pack header was fully read" */
2567 return PH_ERROR_EOF;
2569 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2570 /* "protocol error (pack signature mismatch detected)" */
2571 return PH_ERROR_PACK_SIGNATURE;
2572 if (!pack_version_ok(header->hdr_version))
2573 /* "protocol error (pack version unsupported)" */
2574 return PH_ERROR_PROTOCOL;
2575 return 0;