Merge branch 'bc/maint-keep-pack'
[git/debian.git] / sha1_file.c
blob491220572b8708a520aa54079a5246f9f2df033e
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 * Do not call this directly as this leaks p->pack_fd on error return;
677 * call open_packed_git() instead.
679 static int open_packed_git_1(struct packed_git *p)
681 struct stat st;
682 struct pack_header hdr;
683 unsigned char sha1[20];
684 unsigned char *idx_sha1;
685 long fd_flag;
687 if (!p->index_data && open_pack_index(p))
688 return error("packfile %s index unavailable", p->pack_name);
690 p->pack_fd = open(p->pack_name, O_RDONLY);
691 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
692 return -1;
694 /* If we created the struct before we had the pack we lack size. */
695 if (!p->pack_size) {
696 if (!S_ISREG(st.st_mode))
697 return error("packfile %s not a regular file", p->pack_name);
698 p->pack_size = st.st_size;
699 } else if (p->pack_size != st.st_size)
700 return error("packfile %s size changed", p->pack_name);
702 /* We leave these file descriptors open with sliding mmap;
703 * there is no point keeping them open across exec(), though.
705 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
706 if (fd_flag < 0)
707 return error("cannot determine file descriptor flags");
708 fd_flag |= FD_CLOEXEC;
709 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
710 return error("cannot set FD_CLOEXEC");
712 /* Verify we recognize this pack file format. */
713 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
714 return error("file %s is far too short to be a packfile", p->pack_name);
715 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
716 return error("file %s is not a GIT packfile", p->pack_name);
717 if (!pack_version_ok(hdr.hdr_version))
718 return error("packfile %s is version %"PRIu32" and not"
719 " supported (try upgrading GIT to a newer version)",
720 p->pack_name, ntohl(hdr.hdr_version));
722 /* Verify the pack matches its index. */
723 if (p->num_objects != ntohl(hdr.hdr_entries))
724 return error("packfile %s claims to have %"PRIu32" objects"
725 " while index indicates %"PRIu32" objects",
726 p->pack_name, ntohl(hdr.hdr_entries),
727 p->num_objects);
728 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
729 return error("end of packfile %s is unavailable", p->pack_name);
730 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
731 return error("packfile %s signature is unavailable", p->pack_name);
732 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
733 if (hashcmp(sha1, idx_sha1))
734 return error("packfile %s does not match index", p->pack_name);
735 return 0;
738 static int open_packed_git(struct packed_git *p)
740 if (!open_packed_git_1(p))
741 return 0;
742 if (p->pack_fd != -1) {
743 close(p->pack_fd);
744 p->pack_fd = -1;
746 return -1;
749 static int in_window(struct pack_window *win, off_t offset)
751 /* We must promise at least 20 bytes (one hash) after the
752 * offset is available from this window, otherwise the offset
753 * is not actually in this window and a different window (which
754 * has that one hash excess) must be used. This is to support
755 * the object header and delta base parsing routines below.
757 off_t win_off = win->offset;
758 return win_off <= offset
759 && (offset + 20) <= (win_off + win->len);
762 unsigned char* use_pack(struct packed_git *p,
763 struct pack_window **w_cursor,
764 off_t offset,
765 unsigned int *left)
767 struct pack_window *win = *w_cursor;
769 if (p->pack_fd == -1 && open_packed_git(p))
770 die("packfile %s cannot be accessed", p->pack_name);
772 /* Since packfiles end in a hash of their content and its
773 * pointless to ask for an offset into the middle of that
774 * hash, and the in_window function above wouldn't match
775 * don't allow an offset too close to the end of the file.
777 if (offset > (p->pack_size - 20))
778 die("offset beyond end of packfile (truncated pack?)");
780 if (!win || !in_window(win, offset)) {
781 if (win)
782 win->inuse_cnt--;
783 for (win = p->windows; win; win = win->next) {
784 if (in_window(win, offset))
785 break;
787 if (!win) {
788 size_t window_align = packed_git_window_size / 2;
789 off_t len;
790 win = xcalloc(1, sizeof(*win));
791 win->offset = (offset / window_align) * window_align;
792 len = p->pack_size - win->offset;
793 if (len > packed_git_window_size)
794 len = packed_git_window_size;
795 win->len = (size_t)len;
796 pack_mapped += win->len;
797 while (packed_git_limit < pack_mapped
798 && unuse_one_window(p, p->pack_fd))
799 ; /* nothing */
800 win->base = xmmap(NULL, win->len,
801 PROT_READ, MAP_PRIVATE,
802 p->pack_fd, win->offset);
803 if (win->base == MAP_FAILED)
804 die("packfile %s cannot be mapped: %s",
805 p->pack_name,
806 strerror(errno));
807 pack_mmap_calls++;
808 pack_open_windows++;
809 if (pack_mapped > peak_pack_mapped)
810 peak_pack_mapped = pack_mapped;
811 if (pack_open_windows > peak_pack_open_windows)
812 peak_pack_open_windows = pack_open_windows;
813 win->next = p->windows;
814 p->windows = win;
817 if (win != *w_cursor) {
818 win->last_used = pack_used_ctr++;
819 win->inuse_cnt++;
820 *w_cursor = win;
822 offset -= win->offset;
823 if (left)
824 *left = win->len - xsize_t(offset);
825 return win->base + offset;
828 static struct packed_git *alloc_packed_git(int extra)
830 struct packed_git *p = xmalloc(sizeof(*p) + extra);
831 memset(p, 0, sizeof(*p));
832 p->pack_fd = -1;
833 return p;
836 struct packed_git *add_packed_git(const char *path, int path_len, int local)
838 struct stat st;
839 struct packed_git *p = alloc_packed_git(path_len + 2);
842 * Make sure a corresponding .pack file exists and that
843 * the index looks sane.
845 path_len -= strlen(".idx");
846 if (path_len < 1) {
847 free(p);
848 return NULL;
850 memcpy(p->pack_name, path, path_len);
852 strcpy(p->pack_name + path_len, ".keep");
853 if (!access(p->pack_name, F_OK))
854 p->pack_keep = 1;
856 strcpy(p->pack_name + path_len, ".pack");
857 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
858 free(p);
859 return NULL;
862 /* ok, it looks sane as far as we can check without
863 * actually mapping the pack file.
865 p->pack_size = st.st_size;
866 p->pack_local = local;
867 p->mtime = st.st_mtime;
868 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
869 hashclr(p->sha1);
870 return p;
873 struct packed_git *parse_pack_index(unsigned char *sha1)
875 const char *idx_path = sha1_pack_index_name(sha1);
876 const char *path = sha1_pack_name(sha1);
877 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
879 strcpy(p->pack_name, path);
880 hashcpy(p->sha1, sha1);
881 if (check_packed_git_idx(idx_path, p)) {
882 free(p);
883 return NULL;
886 return p;
889 void install_packed_git(struct packed_git *pack)
891 pack->next = packed_git;
892 packed_git = pack;
895 static void prepare_packed_git_one(char *objdir, int local)
897 /* Ensure that this buffer is large enough so that we can
898 append "/pack/" without clobbering the stack even if
899 strlen(objdir) were PATH_MAX. */
900 char path[PATH_MAX + 1 + 4 + 1 + 1];
901 int len;
902 DIR *dir;
903 struct dirent *de;
905 sprintf(path, "%s/pack", objdir);
906 len = strlen(path);
907 dir = opendir(path);
908 if (!dir) {
909 if (errno != ENOENT)
910 error("unable to open object pack directory: %s: %s",
911 path, strerror(errno));
912 return;
914 path[len++] = '/';
915 while ((de = readdir(dir)) != NULL) {
916 int namelen = strlen(de->d_name);
917 struct packed_git *p;
919 if (!has_extension(de->d_name, ".idx"))
920 continue;
922 if (len + namelen + 1 > sizeof(path))
923 continue;
925 /* Don't reopen a pack we already have. */
926 strcpy(path + len, de->d_name);
927 for (p = packed_git; p; p = p->next) {
928 if (!memcmp(path, p->pack_name, len + namelen - 4))
929 break;
931 if (p)
932 continue;
933 /* See if it really is a valid .idx file with corresponding
934 * .pack file that we can map.
936 p = add_packed_git(path, len + namelen, local);
937 if (!p)
938 continue;
939 install_packed_git(p);
941 closedir(dir);
944 static int sort_pack(const void *a_, const void *b_)
946 struct packed_git *a = *((struct packed_git **)a_);
947 struct packed_git *b = *((struct packed_git **)b_);
948 int st;
951 * Local packs tend to contain objects specific to our
952 * variant of the project than remote ones. In addition,
953 * remote ones could be on a network mounted filesystem.
954 * Favor local ones for these reasons.
956 st = a->pack_local - b->pack_local;
957 if (st)
958 return -st;
961 * Younger packs tend to contain more recent objects,
962 * and more recent objects tend to get accessed more
963 * often.
965 if (a->mtime < b->mtime)
966 return 1;
967 else if (a->mtime == b->mtime)
968 return 0;
969 return -1;
972 static void rearrange_packed_git(void)
974 struct packed_git **ary, *p;
975 int i, n;
977 for (n = 0, p = packed_git; p; p = p->next)
978 n++;
979 if (n < 2)
980 return;
982 /* prepare an array of packed_git for easier sorting */
983 ary = xcalloc(n, sizeof(struct packed_git *));
984 for (n = 0, p = packed_git; p; p = p->next)
985 ary[n++] = p;
987 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
989 /* link them back again */
990 for (i = 0; i < n - 1; i++)
991 ary[i]->next = ary[i + 1];
992 ary[n - 1]->next = NULL;
993 packed_git = ary[0];
995 free(ary);
998 static int prepare_packed_git_run_once = 0;
999 void prepare_packed_git(void)
1001 struct alternate_object_database *alt;
1003 if (prepare_packed_git_run_once)
1004 return;
1005 prepare_packed_git_one(get_object_directory(), 1);
1006 prepare_alt_odb();
1007 for (alt = alt_odb_list; alt; alt = alt->next) {
1008 alt->name[-1] = 0;
1009 prepare_packed_git_one(alt->base, 0);
1010 alt->name[-1] = '/';
1012 rearrange_packed_git();
1013 prepare_packed_git_run_once = 1;
1016 void reprepare_packed_git(void)
1018 discard_revindex();
1019 prepare_packed_git_run_once = 0;
1020 prepare_packed_git();
1023 static void mark_bad_packed_object(struct packed_git *p,
1024 const unsigned char *sha1)
1026 unsigned i;
1027 for (i = 0; i < p->num_bad_objects; i++)
1028 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1029 return;
1030 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1031 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1032 p->num_bad_objects++;
1035 static int has_packed_and_bad(const unsigned char *sha1)
1037 struct packed_git *p;
1038 unsigned i;
1040 for (p = packed_git; p; p = p->next)
1041 for (i = 0; i < p->num_bad_objects; i++)
1042 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1043 return 1;
1044 return 0;
1047 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
1049 unsigned char real_sha1[20];
1050 hash_sha1_file(map, size, type, real_sha1);
1051 return hashcmp(sha1, real_sha1) ? -1 : 0;
1054 static int git_open_noatime(const char *name)
1056 static int sha1_file_open_flag = O_NOATIME;
1057 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1059 /* Might the failure be due to O_NOATIME? */
1060 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1061 fd = open(name, O_RDONLY);
1062 if (fd >= 0)
1063 sha1_file_open_flag = 0;
1065 return fd;
1068 static int open_sha1_file(const unsigned char *sha1)
1070 int fd;
1071 char *name = sha1_file_name(sha1);
1072 struct alternate_object_database *alt;
1074 fd = git_open_noatime(name);
1075 if (fd >= 0)
1076 return fd;
1078 prepare_alt_odb();
1079 errno = ENOENT;
1080 for (alt = alt_odb_list; alt; alt = alt->next) {
1081 name = alt->name;
1082 fill_sha1_path(name, sha1);
1083 fd = git_open_noatime(alt->base);
1084 if (fd >= 0)
1085 return fd;
1087 return -1;
1090 static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
1092 void *map;
1093 int fd;
1095 fd = open_sha1_file(sha1);
1096 map = NULL;
1097 if (fd >= 0) {
1098 struct stat st;
1100 if (!fstat(fd, &st)) {
1101 *size = xsize_t(st.st_size);
1102 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
1104 close(fd);
1106 return map;
1109 static int legacy_loose_object(unsigned char *map)
1111 unsigned int word;
1114 * Is it a zlib-compressed buffer? If so, the first byte
1115 * must be 0x78 (15-bit window size, deflated), and the
1116 * first 16-bit word is evenly divisible by 31
1118 word = (map[0] << 8) + map[1];
1119 if (map[0] == 0x78 && !(word % 31))
1120 return 1;
1121 else
1122 return 0;
1125 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
1127 unsigned shift;
1128 unsigned char c;
1129 unsigned long size;
1130 unsigned long used = 0;
1132 c = buf[used++];
1133 *type = (c >> 4) & 7;
1134 size = c & 15;
1135 shift = 4;
1136 while (c & 0x80) {
1137 if (len <= used)
1138 return 0;
1139 if (sizeof(long) * 8 <= shift)
1140 return 0;
1141 c = buf[used++];
1142 size += (c & 0x7f) << shift;
1143 shift += 7;
1145 *sizep = size;
1146 return used;
1149 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1151 unsigned long size, used;
1152 static const char valid_loose_object_type[8] = {
1153 0, /* OBJ_EXT */
1154 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1155 0, /* "delta" and others are invalid in a loose object */
1157 enum object_type type;
1159 /* Get the data stream */
1160 memset(stream, 0, sizeof(*stream));
1161 stream->next_in = map;
1162 stream->avail_in = mapsize;
1163 stream->next_out = buffer;
1164 stream->avail_out = bufsiz;
1166 if (legacy_loose_object(map)) {
1167 inflateInit(stream);
1168 return inflate(stream, 0);
1173 * There used to be a second loose object header format which
1174 * was meant to mimic the in-pack format, allowing for direct
1175 * copy of the object data. This format turned up not to be
1176 * really worth it and we don't write it any longer. But we
1177 * can still read it.
1179 used = unpack_object_header_gently(map, mapsize, &type, &size);
1180 if (!used || !valid_loose_object_type[type])
1181 return -1;
1182 map += used;
1183 mapsize -= used;
1185 /* Set up the stream for the rest.. */
1186 stream->next_in = map;
1187 stream->avail_in = mapsize;
1188 inflateInit(stream);
1190 /* And generate the fake traditional header */
1191 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
1192 typename(type), size);
1193 return 0;
1196 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
1198 int bytes = strlen(buffer) + 1;
1199 unsigned char *buf = xmalloc(1+size);
1200 unsigned long n;
1201 int status = Z_OK;
1203 n = stream->total_out - bytes;
1204 if (n > size)
1205 n = size;
1206 memcpy(buf, (char *) buffer + bytes, n);
1207 bytes = n;
1208 if (bytes <= size) {
1210 * The above condition must be (bytes <= size), not
1211 * (bytes < size). In other words, even though we
1212 * expect no more output and set avail_out to zer0,
1213 * the input zlib stream may have bytes that express
1214 * "this concludes the stream", and we *do* want to
1215 * eat that input.
1217 * Otherwise we would not be able to test that we
1218 * consumed all the input to reach the expected size;
1219 * we also want to check that zlib tells us that all
1220 * went well with status == Z_STREAM_END at the end.
1222 stream->next_out = buf + bytes;
1223 stream->avail_out = size - bytes;
1224 while (status == Z_OK)
1225 status = inflate(stream, Z_FINISH);
1227 buf[size] = 0;
1228 if (status == Z_STREAM_END && !stream->avail_in) {
1229 inflateEnd(stream);
1230 return buf;
1233 if (status < 0)
1234 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1235 else if (stream->avail_in)
1236 error("garbage at end of loose object '%s'",
1237 sha1_to_hex(sha1));
1238 free(buf);
1239 return NULL;
1243 * We used to just use "sscanf()", but that's actually way
1244 * too permissive for what we want to check. So do an anal
1245 * object header parse by hand.
1247 static int parse_sha1_header(const char *hdr, unsigned long *sizep)
1249 char type[10];
1250 int i;
1251 unsigned long size;
1254 * The type can be at most ten bytes (including the
1255 * terminating '\0' that we add), and is followed by
1256 * a space.
1258 i = 0;
1259 for (;;) {
1260 char c = *hdr++;
1261 if (c == ' ')
1262 break;
1263 type[i++] = c;
1264 if (i >= sizeof(type))
1265 return -1;
1267 type[i] = 0;
1270 * The length must follow immediately, and be in canonical
1271 * decimal format (ie "010" is not valid).
1273 size = *hdr++ - '0';
1274 if (size > 9)
1275 return -1;
1276 if (size) {
1277 for (;;) {
1278 unsigned long c = *hdr - '0';
1279 if (c > 9)
1280 break;
1281 hdr++;
1282 size = size * 10 + c;
1285 *sizep = size;
1288 * The length must be followed by a zero byte
1290 return *hdr ? -1 : type_from_string(type);
1293 static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
1295 int ret;
1296 z_stream stream;
1297 char hdr[8192];
1299 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
1300 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
1301 return NULL;
1303 return unpack_sha1_rest(&stream, hdr, *size, sha1);
1306 unsigned long get_size_from_delta(struct packed_git *p,
1307 struct pack_window **w_curs,
1308 off_t curpos)
1310 const unsigned char *data;
1311 unsigned char delta_head[20], *in;
1312 z_stream stream;
1313 int st;
1315 memset(&stream, 0, sizeof(stream));
1316 stream.next_out = delta_head;
1317 stream.avail_out = sizeof(delta_head);
1319 inflateInit(&stream);
1320 do {
1321 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1322 stream.next_in = in;
1323 st = inflate(&stream, Z_FINISH);
1324 curpos += stream.next_in - in;
1325 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1326 stream.total_out < sizeof(delta_head));
1327 inflateEnd(&stream);
1328 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1329 die("delta data unpack-initial failed");
1331 /* Examine the initial part of the delta to figure out
1332 * the result size.
1334 data = delta_head;
1336 /* ignore base size */
1337 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1339 /* Read the result size */
1340 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1343 static off_t get_delta_base(struct packed_git *p,
1344 struct pack_window **w_curs,
1345 off_t *curpos,
1346 enum object_type type,
1347 off_t delta_obj_offset)
1349 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
1350 off_t base_offset;
1352 /* use_pack() assured us we have [base_info, base_info + 20)
1353 * as a range that we can look at without walking off the
1354 * end of the mapped window. Its actually the hash size
1355 * that is assured. An OFS_DELTA longer than the hash size
1356 * is stupid, as then a REF_DELTA would be smaller to store.
1358 if (type == OBJ_OFS_DELTA) {
1359 unsigned used = 0;
1360 unsigned char c = base_info[used++];
1361 base_offset = c & 127;
1362 while (c & 128) {
1363 base_offset += 1;
1364 if (!base_offset || MSB(base_offset, 7))
1365 return 0; /* overflow */
1366 c = base_info[used++];
1367 base_offset = (base_offset << 7) + (c & 127);
1369 base_offset = delta_obj_offset - base_offset;
1370 if (base_offset >= delta_obj_offset)
1371 return 0; /* out of bound */
1372 *curpos += used;
1373 } else if (type == OBJ_REF_DELTA) {
1374 /* The base entry _must_ be in the same pack */
1375 base_offset = find_pack_entry_one(base_info, p);
1376 *curpos += 20;
1377 } else
1378 die("I am totally screwed");
1379 return base_offset;
1382 /* forward declaration for a mutually recursive function */
1383 static int packed_object_info(struct packed_git *p, off_t offset,
1384 unsigned long *sizep);
1386 static int packed_delta_info(struct packed_git *p,
1387 struct pack_window **w_curs,
1388 off_t curpos,
1389 enum object_type type,
1390 off_t obj_offset,
1391 unsigned long *sizep)
1393 off_t base_offset;
1395 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1396 type = packed_object_info(p, base_offset, NULL);
1398 /* We choose to only get the type of the base object and
1399 * ignore potentially corrupt pack file that expects the delta
1400 * based on a base with a wrong size. This saves tons of
1401 * inflate() calls.
1403 if (sizep)
1404 *sizep = get_size_from_delta(p, w_curs, curpos);
1406 return type;
1409 static int unpack_object_header(struct packed_git *p,
1410 struct pack_window **w_curs,
1411 off_t *curpos,
1412 unsigned long *sizep)
1414 unsigned char *base;
1415 unsigned int left;
1416 unsigned long used;
1417 enum object_type type;
1419 /* use_pack() assures us we have [base, base + 20) available
1420 * as a range that we can look at at. (Its actually the hash
1421 * size that is assured.) With our object header encoding
1422 * the maximum deflated object size is 2^137, which is just
1423 * insane, so we know won't exceed what we have been given.
1425 base = use_pack(p, w_curs, *curpos, &left);
1426 used = unpack_object_header_gently(base, left, &type, sizep);
1427 if (!used)
1428 die("object offset outside of pack file");
1429 *curpos += used;
1431 return type;
1434 const char *packed_object_info_detail(struct packed_git *p,
1435 off_t obj_offset,
1436 unsigned long *size,
1437 unsigned long *store_size,
1438 unsigned int *delta_chain_length,
1439 unsigned char *base_sha1)
1441 struct pack_window *w_curs = NULL;
1442 off_t curpos;
1443 unsigned long dummy;
1444 unsigned char *next_sha1;
1445 enum object_type type;
1446 struct revindex_entry *revidx;
1448 *delta_chain_length = 0;
1449 curpos = obj_offset;
1450 type = unpack_object_header(p, &w_curs, &curpos, size);
1452 revidx = find_pack_revindex(p, obj_offset);
1453 *store_size = revidx[1].offset - obj_offset;
1455 for (;;) {
1456 switch (type) {
1457 default:
1458 die("pack %s contains unknown object type %d",
1459 p->pack_name, type);
1460 case OBJ_COMMIT:
1461 case OBJ_TREE:
1462 case OBJ_BLOB:
1463 case OBJ_TAG:
1464 unuse_pack(&w_curs);
1465 return typename(type);
1466 case OBJ_OFS_DELTA:
1467 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
1468 if (!obj_offset)
1469 die("pack %s contains bad delta base reference of type %s",
1470 p->pack_name, typename(type));
1471 if (*delta_chain_length == 0) {
1472 revidx = find_pack_revindex(p, obj_offset);
1473 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
1475 break;
1476 case OBJ_REF_DELTA:
1477 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
1478 if (*delta_chain_length == 0)
1479 hashcpy(base_sha1, next_sha1);
1480 obj_offset = find_pack_entry_one(next_sha1, p);
1481 break;
1483 (*delta_chain_length)++;
1484 curpos = obj_offset;
1485 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
1489 static int packed_object_info(struct packed_git *p, off_t obj_offset,
1490 unsigned long *sizep)
1492 struct pack_window *w_curs = NULL;
1493 unsigned long size;
1494 off_t curpos = obj_offset;
1495 enum object_type type;
1497 type = unpack_object_header(p, &w_curs, &curpos, &size);
1499 switch (type) {
1500 case OBJ_OFS_DELTA:
1501 case OBJ_REF_DELTA:
1502 type = packed_delta_info(p, &w_curs, curpos,
1503 type, obj_offset, sizep);
1504 break;
1505 case OBJ_COMMIT:
1506 case OBJ_TREE:
1507 case OBJ_BLOB:
1508 case OBJ_TAG:
1509 if (sizep)
1510 *sizep = size;
1511 break;
1512 default:
1513 die("pack %s contains unknown object type %d",
1514 p->pack_name, type);
1516 unuse_pack(&w_curs);
1517 return type;
1520 static void *unpack_compressed_entry(struct packed_git *p,
1521 struct pack_window **w_curs,
1522 off_t curpos,
1523 unsigned long size)
1525 int st;
1526 z_stream stream;
1527 unsigned char *buffer, *in;
1529 buffer = xmalloc(size + 1);
1530 buffer[size] = 0;
1531 memset(&stream, 0, sizeof(stream));
1532 stream.next_out = buffer;
1533 stream.avail_out = size;
1535 inflateInit(&stream);
1536 do {
1537 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1538 stream.next_in = in;
1539 st = inflate(&stream, Z_FINISH);
1540 curpos += stream.next_in - in;
1541 } while (st == Z_OK || st == Z_BUF_ERROR);
1542 inflateEnd(&stream);
1543 if ((st != Z_STREAM_END) || stream.total_out != size) {
1544 free(buffer);
1545 return NULL;
1548 return buffer;
1551 #define MAX_DELTA_CACHE (256)
1553 static size_t delta_base_cached;
1555 static struct delta_base_cache_lru_list {
1556 struct delta_base_cache_lru_list *prev;
1557 struct delta_base_cache_lru_list *next;
1558 } delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1560 static struct delta_base_cache_entry {
1561 struct delta_base_cache_lru_list lru;
1562 void *data;
1563 struct packed_git *p;
1564 off_t base_offset;
1565 unsigned long size;
1566 enum object_type type;
1567 } delta_base_cache[MAX_DELTA_CACHE];
1569 static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1571 unsigned long hash;
1573 hash = (unsigned long)p + (unsigned long)base_offset;
1574 hash += (hash >> 8) + (hash >> 16);
1575 return hash % MAX_DELTA_CACHE;
1578 static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
1579 unsigned long *base_size, enum object_type *type, int keep_cache)
1581 void *ret;
1582 unsigned long hash = pack_entry_hash(p, base_offset);
1583 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1585 ret = ent->data;
1586 if (!ret || ent->p != p || ent->base_offset != base_offset)
1587 return unpack_entry(p, base_offset, type, base_size);
1589 if (!keep_cache) {
1590 ent->data = NULL;
1591 ent->lru.next->prev = ent->lru.prev;
1592 ent->lru.prev->next = ent->lru.next;
1593 delta_base_cached -= ent->size;
1594 } else {
1595 ret = xmemdupz(ent->data, ent->size);
1597 *type = ent->type;
1598 *base_size = ent->size;
1599 return ret;
1602 static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1604 if (ent->data) {
1605 free(ent->data);
1606 ent->data = NULL;
1607 ent->lru.next->prev = ent->lru.prev;
1608 ent->lru.prev->next = ent->lru.next;
1609 delta_base_cached -= ent->size;
1613 static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1614 void *base, unsigned long base_size, enum object_type type)
1616 unsigned long hash = pack_entry_hash(p, base_offset);
1617 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1618 struct delta_base_cache_lru_list *lru;
1620 release_delta_base_cache(ent);
1621 delta_base_cached += base_size;
1623 for (lru = delta_base_cache_lru.next;
1624 delta_base_cached > delta_base_cache_limit
1625 && lru != &delta_base_cache_lru;
1626 lru = lru->next) {
1627 struct delta_base_cache_entry *f = (void *)lru;
1628 if (f->type == OBJ_BLOB)
1629 release_delta_base_cache(f);
1631 for (lru = delta_base_cache_lru.next;
1632 delta_base_cached > delta_base_cache_limit
1633 && lru != &delta_base_cache_lru;
1634 lru = lru->next) {
1635 struct delta_base_cache_entry *f = (void *)lru;
1636 release_delta_base_cache(f);
1639 ent->p = p;
1640 ent->base_offset = base_offset;
1641 ent->type = type;
1642 ent->data = base;
1643 ent->size = base_size;
1644 ent->lru.next = &delta_base_cache_lru;
1645 ent->lru.prev = delta_base_cache_lru.prev;
1646 delta_base_cache_lru.prev->next = &ent->lru;
1647 delta_base_cache_lru.prev = &ent->lru;
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)
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;
1669 unuse_pack(w_curs);
1670 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
1671 if (!base) {
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.
1678 struct revindex_entry *revidx = find_pack_revindex(p, base_offset);
1679 const unsigned char *base_sha1 =
1680 nth_packed_object_sha1(p, revidx->nr);
1681 error("failed to read delta base object %s"
1682 " at offset %"PRIuMAX" from %s",
1683 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1684 p->pack_name);
1685 mark_bad_packed_object(p, base_sha1);
1686 base = read_object(base_sha1, type, &base_size);
1687 if (!base)
1688 return NULL;
1691 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
1692 if (!delta_data) {
1693 error("failed to unpack compressed delta "
1694 "at offset %"PRIuMAX" from %s",
1695 (uintmax_t)curpos, p->pack_name);
1696 free(base);
1697 return NULL;
1699 result = patch_delta(base, base_size,
1700 delta_data, delta_size,
1701 sizep);
1702 if (!result)
1703 die("failed to apply delta");
1704 free(delta_data);
1705 add_delta_base_cache(p, base_offset, base, base_size, *type);
1706 return result;
1709 void *unpack_entry(struct packed_git *p, off_t obj_offset,
1710 enum object_type *type, unsigned long *sizep)
1712 struct pack_window *w_curs = NULL;
1713 off_t curpos = obj_offset;
1714 void *data;
1716 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1717 switch (*type) {
1718 case OBJ_OFS_DELTA:
1719 case OBJ_REF_DELTA:
1720 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1721 obj_offset, type, sizep);
1722 break;
1723 case OBJ_COMMIT:
1724 case OBJ_TREE:
1725 case OBJ_BLOB:
1726 case OBJ_TAG:
1727 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
1728 break;
1729 default:
1730 data = NULL;
1731 error("unknown object type %i at offset %"PRIuMAX" in %s",
1732 *type, (uintmax_t)obj_offset, p->pack_name);
1734 unuse_pack(&w_curs);
1735 return data;
1738 const unsigned char *nth_packed_object_sha1(struct packed_git *p,
1739 uint32_t n)
1741 const unsigned char *index = p->index_data;
1742 if (!index) {
1743 if (open_pack_index(p))
1744 return NULL;
1745 index = p->index_data;
1747 if (n >= p->num_objects)
1748 return NULL;
1749 index += 4 * 256;
1750 if (p->index_version == 1) {
1751 return index + 24 * n + 4;
1752 } else {
1753 index += 8;
1754 return index + 20 * n;
1758 off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1760 const unsigned char *index = p->index_data;
1761 index += 4 * 256;
1762 if (p->index_version == 1) {
1763 return ntohl(*((uint32_t *)(index + 24 * n)));
1764 } else {
1765 uint32_t off;
1766 index += 8 + p->num_objects * (20 + 4);
1767 off = ntohl(*((uint32_t *)(index + 4 * n)));
1768 if (!(off & 0x80000000))
1769 return off;
1770 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1771 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1772 ntohl(*((uint32_t *)(index + 4)));
1776 off_t find_pack_entry_one(const unsigned char *sha1,
1777 struct packed_git *p)
1779 const uint32_t *level1_ofs = p->index_data;
1780 const unsigned char *index = p->index_data;
1781 unsigned hi, lo, stride;
1782 static int use_lookup = -1;
1783 static int debug_lookup = -1;
1785 if (debug_lookup < 0)
1786 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
1788 if (!index) {
1789 if (open_pack_index(p))
1790 return 0;
1791 level1_ofs = p->index_data;
1792 index = p->index_data;
1794 if (p->index_version > 1) {
1795 level1_ofs += 2;
1796 index += 8;
1798 index += 4 * 256;
1799 hi = ntohl(level1_ofs[*sha1]);
1800 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1801 if (p->index_version > 1) {
1802 stride = 20;
1803 } else {
1804 stride = 24;
1805 index += 4;
1808 if (debug_lookup)
1809 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
1810 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1812 if (use_lookup < 0)
1813 use_lookup = !!getenv("GIT_USE_LOOKUP");
1814 if (use_lookup) {
1815 int pos = sha1_entry_pos(index, stride, 0,
1816 lo, hi, p->num_objects, sha1);
1817 if (pos < 0)
1818 return 0;
1819 return nth_packed_object_offset(p, pos);
1822 do {
1823 unsigned mi = (lo + hi) / 2;
1824 int cmp = hashcmp(index + mi * stride, sha1);
1826 if (debug_lookup)
1827 printf("lo %u hi %u rg %u mi %u\n",
1828 lo, hi, hi - lo, mi);
1829 if (!cmp)
1830 return nth_packed_object_offset(p, mi);
1831 if (cmp > 0)
1832 hi = mi;
1833 else
1834 lo = mi+1;
1835 } while (lo < hi);
1836 return 0;
1839 int matches_pack_name(struct packed_git *p, const char *name)
1841 const char *last_c, *c;
1843 if (!strcmp(p->pack_name, name))
1844 return 1;
1846 for (c = p->pack_name, last_c = c; *c;)
1847 if (*c == '/')
1848 last_c = ++c;
1849 else
1850 ++c;
1851 if (!strcmp(last_c, name))
1852 return 1;
1854 return 0;
1857 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1859 static struct packed_git *last_found = (void *)1;
1860 struct packed_git *p;
1861 off_t offset;
1863 prepare_packed_git();
1864 if (!packed_git)
1865 return 0;
1866 p = (last_found == (void *)1) ? packed_git : last_found;
1868 do {
1869 if (ignore_packed) {
1870 const char **ig;
1871 for (ig = ignore_packed; *ig; ig++)
1872 if (matches_pack_name(p, *ig))
1873 break;
1874 if (*ig)
1875 goto next;
1878 if (p->num_bad_objects) {
1879 unsigned i;
1880 for (i = 0; i < p->num_bad_objects; i++)
1881 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1882 goto next;
1885 offset = find_pack_entry_one(sha1, p);
1886 if (offset) {
1888 * We are about to tell the caller where they can
1889 * locate the requested object. We better make
1890 * sure the packfile is still here and can be
1891 * accessed before supplying that answer, as
1892 * it may have been deleted since the index
1893 * was loaded!
1895 if (p->pack_fd == -1 && open_packed_git(p)) {
1896 error("packfile %s cannot be accessed", p->pack_name);
1897 goto next;
1899 e->offset = offset;
1900 e->p = p;
1901 hashcpy(e->sha1, sha1);
1902 last_found = p;
1903 return 1;
1906 next:
1907 if (p == last_found)
1908 p = packed_git;
1909 else
1910 p = p->next;
1911 if (p == last_found)
1912 p = p->next;
1913 } while (p);
1914 return 0;
1917 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1918 struct packed_git *packs)
1920 struct packed_git *p;
1922 for (p = packs; p; p = p->next) {
1923 if (find_pack_entry_one(sha1, p))
1924 return p;
1926 return NULL;
1930 static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
1932 int status;
1933 unsigned long mapsize, size;
1934 void *map;
1935 z_stream stream;
1936 char hdr[32];
1938 map = map_sha1_file(sha1, &mapsize);
1939 if (!map)
1940 return error("unable to find %s", sha1_to_hex(sha1));
1941 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1942 status = error("unable to unpack %s header",
1943 sha1_to_hex(sha1));
1944 else if ((status = parse_sha1_header(hdr, &size)) < 0)
1945 status = error("unable to parse %s header", sha1_to_hex(sha1));
1946 else if (sizep)
1947 *sizep = size;
1948 inflateEnd(&stream);
1949 munmap(map, mapsize);
1950 return status;
1953 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
1955 struct pack_entry e;
1956 int status;
1958 if (!find_pack_entry(sha1, &e, NULL)) {
1959 /* Most likely it's a loose object. */
1960 status = sha1_loose_object_info(sha1, sizep);
1961 if (status >= 0)
1962 return status;
1964 /* Not a loose object; someone else may have just packed it. */
1965 reprepare_packed_git();
1966 if (!find_pack_entry(sha1, &e, NULL))
1967 return status;
1969 return packed_object_info(e.p, e.offset, sizep);
1972 static void *read_packed_sha1(const unsigned char *sha1,
1973 enum object_type *type, unsigned long *size)
1975 struct pack_entry e;
1976 void *data;
1978 if (!find_pack_entry(sha1, &e, NULL))
1979 return NULL;
1980 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1981 if (!data) {
1983 * We're probably in deep shit, but let's try to fetch
1984 * the required object anyway from another pack or loose.
1985 * This should happen only in the presence of a corrupted
1986 * pack, and is better than failing outright.
1988 error("failed to read object %s at offset %"PRIuMAX" from %s",
1989 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1990 mark_bad_packed_object(e.p, sha1);
1991 data = read_object(sha1, type, size);
1993 return data;
1997 * This is meant to hold a *small* number of objects that you would
1998 * want read_sha1_file() to be able to return, but yet you do not want
1999 * to write them into the object store (e.g. a browse-only
2000 * application).
2002 static struct cached_object {
2003 unsigned char sha1[20];
2004 enum object_type type;
2005 void *buf;
2006 unsigned long size;
2007 } *cached_objects;
2008 static int cached_object_nr, cached_object_alloc;
2010 static struct cached_object empty_tree = {
2011 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
2012 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
2013 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
2014 OBJ_TREE,
2019 static struct cached_object *find_cached_object(const unsigned char *sha1)
2021 int i;
2022 struct cached_object *co = cached_objects;
2024 for (i = 0; i < cached_object_nr; i++, co++) {
2025 if (!hashcmp(co->sha1, sha1))
2026 return co;
2028 if (!hashcmp(sha1, empty_tree.sha1))
2029 return &empty_tree;
2030 return NULL;
2033 int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2034 unsigned char *sha1)
2036 struct cached_object *co;
2038 hash_sha1_file(buf, len, typename(type), sha1);
2039 if (has_sha1_file(sha1) || find_cached_object(sha1))
2040 return 0;
2041 if (cached_object_alloc <= cached_object_nr) {
2042 cached_object_alloc = alloc_nr(cached_object_alloc);
2043 cached_objects = xrealloc(cached_objects,
2044 sizeof(*cached_objects) *
2045 cached_object_alloc);
2047 co = &cached_objects[cached_object_nr++];
2048 co->size = len;
2049 co->type = type;
2050 co->buf = xmalloc(len);
2051 memcpy(co->buf, buf, len);
2052 hashcpy(co->sha1, sha1);
2053 return 0;
2056 void *read_object(const unsigned char *sha1, enum object_type *type,
2057 unsigned long *size)
2059 unsigned long mapsize;
2060 void *map, *buf;
2061 struct cached_object *co;
2063 co = find_cached_object(sha1);
2064 if (co) {
2065 *type = co->type;
2066 *size = co->size;
2067 return xmemdupz(co->buf, co->size);
2070 buf = read_packed_sha1(sha1, type, size);
2071 if (buf)
2072 return buf;
2073 map = map_sha1_file(sha1, &mapsize);
2074 if (map) {
2075 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
2076 munmap(map, mapsize);
2077 return buf;
2079 reprepare_packed_git();
2080 return read_packed_sha1(sha1, type, size);
2083 void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
2084 unsigned long *size)
2086 void *data = read_object(sha1, type, size);
2087 /* legacy behavior is to die on corrupted objects */
2088 if (!data && (has_loose_object(sha1) || has_packed_and_bad(sha1)))
2089 die("object %s is corrupted", sha1_to_hex(sha1));
2090 return data;
2093 void *read_object_with_reference(const unsigned char *sha1,
2094 const char *required_type_name,
2095 unsigned long *size,
2096 unsigned char *actual_sha1_return)
2098 enum object_type type, required_type;
2099 void *buffer;
2100 unsigned long isize;
2101 unsigned char actual_sha1[20];
2103 required_type = type_from_string(required_type_name);
2104 hashcpy(actual_sha1, sha1);
2105 while (1) {
2106 int ref_length = -1;
2107 const char *ref_type = NULL;
2109 buffer = read_sha1_file(actual_sha1, &type, &isize);
2110 if (!buffer)
2111 return NULL;
2112 if (type == required_type) {
2113 *size = isize;
2114 if (actual_sha1_return)
2115 hashcpy(actual_sha1_return, actual_sha1);
2116 return buffer;
2118 /* Handle references */
2119 else if (type == OBJ_COMMIT)
2120 ref_type = "tree ";
2121 else if (type == OBJ_TAG)
2122 ref_type = "object ";
2123 else {
2124 free(buffer);
2125 return NULL;
2127 ref_length = strlen(ref_type);
2129 if (ref_length + 40 > isize ||
2130 memcmp(buffer, ref_type, ref_length) ||
2131 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
2132 free(buffer);
2133 return NULL;
2135 free(buffer);
2136 /* Now we have the ID of the referred-to object in
2137 * actual_sha1. Check again. */
2141 static void write_sha1_file_prepare(const void *buf, unsigned long len,
2142 const char *type, unsigned char *sha1,
2143 char *hdr, int *hdrlen)
2145 git_SHA_CTX c;
2147 /* Generate the header */
2148 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
2150 /* Sha1.. */
2151 git_SHA1_Init(&c);
2152 git_SHA1_Update(&c, hdr, *hdrlen);
2153 git_SHA1_Update(&c, buf, len);
2154 git_SHA1_Final(sha1, &c);
2158 * Move the just written object into its final resting place
2160 int move_temp_to_file(const char *tmpfile, const char *filename)
2162 int ret = 0;
2163 if (link(tmpfile, filename))
2164 ret = errno;
2167 * Coda hack - coda doesn't like cross-directory links,
2168 * so we fall back to a rename, which will mean that it
2169 * won't be able to check collisions, but that's not a
2170 * big deal.
2172 * The same holds for FAT formatted media.
2174 * When this succeeds, we just return 0. We have nothing
2175 * left to unlink.
2177 if (ret && ret != EEXIST) {
2178 if (!rename(tmpfile, filename))
2179 return 0;
2180 ret = errno;
2182 unlink(tmpfile);
2183 if (ret) {
2184 if (ret != EEXIST) {
2185 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
2187 /* FIXME!!! Collision check here ? */
2190 return 0;
2193 static int write_buffer(int fd, const void *buf, size_t len)
2195 if (write_in_full(fd, buf, len) < 0)
2196 return error("file write error (%s)", strerror(errno));
2197 return 0;
2200 int hash_sha1_file(const void *buf, unsigned long len, const char *type,
2201 unsigned char *sha1)
2203 char hdr[32];
2204 int hdrlen;
2205 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2206 return 0;
2209 /* Finalize a file on disk, and close it. */
2210 static void close_sha1_file(int fd)
2212 if (fsync_object_files)
2213 fsync_or_die(fd, "sha1 file");
2214 fchmod(fd, 0444);
2215 if (close(fd) != 0)
2216 die("unable to write sha1 file");
2219 /* Size of directory component, including the ending '/' */
2220 static inline int directory_size(const char *filename)
2222 const char *s = strrchr(filename, '/');
2223 if (!s)
2224 return 0;
2225 return s - filename + 1;
2229 * This creates a temporary file in the same directory as the final
2230 * 'filename'
2232 * We want to avoid cross-directory filename renames, because those
2233 * can have problems on various filesystems (FAT, NFS, Coda).
2235 static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2237 int fd, dirlen = directory_size(filename);
2239 if (dirlen + 20 > bufsiz) {
2240 errno = ENAMETOOLONG;
2241 return -1;
2243 memcpy(buffer, filename, dirlen);
2244 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2245 fd = mkstemp(buffer);
2246 if (fd < 0 && dirlen) {
2247 /* Make sure the directory exists */
2248 memcpy(buffer, filename, dirlen);
2249 buffer[dirlen-1] = 0;
2250 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
2251 return -1;
2253 /* Try again */
2254 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2255 fd = mkstemp(buffer);
2257 return fd;
2260 static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2261 void *buf, unsigned long len, time_t mtime)
2263 int fd, size, ret;
2264 unsigned char *compressed;
2265 z_stream stream;
2266 char *filename;
2267 static char tmpfile[PATH_MAX];
2269 filename = sha1_file_name(sha1);
2270 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
2271 if (fd < 0) {
2272 if (errno == EPERM)
2273 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2274 else
2275 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2278 /* Set it up */
2279 memset(&stream, 0, sizeof(stream));
2280 deflateInit(&stream, zlib_compression_level);
2281 size = 8 + deflateBound(&stream, len+hdrlen);
2282 compressed = xmalloc(size);
2284 /* Compress it */
2285 stream.next_out = compressed;
2286 stream.avail_out = size;
2288 /* First header.. */
2289 stream.next_in = (unsigned char *)hdr;
2290 stream.avail_in = hdrlen;
2291 while (deflate(&stream, 0) == Z_OK)
2292 /* nothing */;
2294 /* Then the data itself.. */
2295 stream.next_in = buf;
2296 stream.avail_in = len;
2297 ret = deflate(&stream, Z_FINISH);
2298 if (ret != Z_STREAM_END)
2299 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2301 ret = deflateEnd(&stream);
2302 if (ret != Z_OK)
2303 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2305 size = stream.total_out;
2307 if (write_buffer(fd, compressed, size) < 0)
2308 die("unable to write sha1 file");
2309 close_sha1_file(fd);
2310 free(compressed);
2312 if (mtime) {
2313 struct utimbuf utb;
2314 utb.actime = mtime;
2315 utb.modtime = mtime;
2316 if (utime(tmpfile, &utb) < 0)
2317 warning("failed utime() on %s: %s",
2318 tmpfile, strerror(errno));
2321 return move_temp_to_file(tmpfile, filename);
2324 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2326 unsigned char sha1[20];
2327 char hdr[32];
2328 int hdrlen;
2330 /* Normally if we have it in the pack then we do not bother writing
2331 * it out into .git/objects/??/?{38} file.
2333 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2334 if (returnsha1)
2335 hashcpy(returnsha1, sha1);
2336 if (has_sha1_file(sha1))
2337 return 0;
2338 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2341 int force_object_loose(const unsigned char *sha1, time_t mtime)
2343 void *buf;
2344 unsigned long len;
2345 enum object_type type;
2346 char hdr[32];
2347 int hdrlen;
2348 int ret;
2350 if (has_loose_object(sha1))
2351 return 0;
2352 buf = read_packed_sha1(sha1, &type, &len);
2353 if (!buf)
2354 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2355 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2356 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2357 free(buf);
2359 return ret;
2362 int has_pack_index(const unsigned char *sha1)
2364 struct stat st;
2365 if (stat(sha1_pack_index_name(sha1), &st))
2366 return 0;
2367 return 1;
2370 int has_pack_file(const unsigned char *sha1)
2372 struct stat st;
2373 if (stat(sha1_pack_name(sha1), &st))
2374 return 0;
2375 return 1;
2378 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
2380 struct pack_entry e;
2381 return find_pack_entry(sha1, &e, ignore_packed);
2384 int has_sha1_file(const unsigned char *sha1)
2386 struct pack_entry e;
2388 if (find_pack_entry(sha1, &e, NULL))
2389 return 1;
2390 return has_loose_object(sha1);
2393 static int index_mem(unsigned char *sha1, void *buf, size_t size,
2394 int write_object, enum object_type type, const char *path)
2396 int ret, re_allocated = 0;
2398 if (!type)
2399 type = OBJ_BLOB;
2402 * Convert blobs to git internal format
2404 if ((type == OBJ_BLOB) && path) {
2405 struct strbuf nbuf = STRBUF_INIT;
2406 if (convert_to_git(path, buf, size, &nbuf,
2407 write_object ? safe_crlf : 0)) {
2408 buf = strbuf_detach(&nbuf, &size);
2409 re_allocated = 1;
2413 if (write_object)
2414 ret = write_sha1_file(buf, size, typename(type), sha1);
2415 else
2416 ret = hash_sha1_file(buf, size, typename(type), sha1);
2417 if (re_allocated)
2418 free(buf);
2419 return ret;
2422 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2423 enum object_type type, const char *path)
2425 int ret;
2426 size_t size = xsize_t(st->st_size);
2428 if (!S_ISREG(st->st_mode)) {
2429 struct strbuf sbuf = STRBUF_INIT;
2430 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2431 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2432 type, path);
2433 else
2434 ret = -1;
2435 strbuf_release(&sbuf);
2436 } else if (size) {
2437 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2438 ret = index_mem(sha1, buf, size, write_object, type, path);
2439 munmap(buf, size);
2440 } else
2441 ret = index_mem(sha1, NULL, size, write_object, type, path);
2442 close(fd);
2443 return ret;
2446 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2448 int fd;
2449 char *target;
2450 size_t len;
2452 switch (st->st_mode & S_IFMT) {
2453 case S_IFREG:
2454 fd = open(path, O_RDONLY);
2455 if (fd < 0)
2456 return error("open(\"%s\"): %s", path,
2457 strerror(errno));
2458 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
2459 return error("%s: failed to insert into database",
2460 path);
2461 break;
2462 case S_IFLNK:
2463 len = xsize_t(st->st_size);
2464 target = xmalloc(len + 1);
2465 if (readlink(path, target, len + 1) != st->st_size) {
2466 char *errstr = strerror(errno);
2467 free(target);
2468 return error("readlink(\"%s\"): %s", path,
2469 errstr);
2471 if (!write_object)
2472 hash_sha1_file(target, len, blob_type, sha1);
2473 else if (write_sha1_file(target, len, blob_type, sha1))
2474 return error("%s: failed to insert into database",
2475 path);
2476 free(target);
2477 break;
2478 case S_IFDIR:
2479 return resolve_gitlink_ref(path, "HEAD", sha1);
2480 default:
2481 return error("%s: unsupported file type", path);
2483 return 0;
2486 int read_pack_header(int fd, struct pack_header *header)
2488 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2489 /* "eof before pack header was fully read" */
2490 return PH_ERROR_EOF;
2492 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2493 /* "protocol error (pack signature mismatch detected)" */
2494 return PH_ERROR_PACK_SIGNATURE;
2495 if (!pack_version_ok(header->hdr_version))
2496 /* "protocol error (pack version unsupported)" */
2497 return PH_ERROR_PROTOCOL;
2498 return 0;