3d7358fe727453b6912098940dd139919f2e73c5
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "delta.h"
11 #include "pack.h"
12 #include "blob.h"
13 #include "commit.h"
14 #include "tag.h"
15 #include "tree.h"
17 #ifndef O_NOATIME
18 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
19 #define O_NOATIME 01000000
20 #else
21 #define O_NOATIME 0
22 #endif
23 #endif
25 const unsigned char null_sha1[20];
27 static unsigned int sha1_file_open_flag = O_NOATIME;
29 static unsigned hexval(char c)
30 {
31 if (c >= '0' && c <= '9')
32 return c - '0';
33 if (c >= 'a' && c <= 'f')
34 return c - 'a' + 10;
35 if (c >= 'A' && c <= 'F')
36 return c - 'A' + 10;
37 return ~0;
38 }
40 int get_sha1_hex(const char *hex, unsigned char *sha1)
41 {
42 int i;
43 for (i = 0; i < 20; i++) {
44 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
45 if (val & ~0xff)
46 return -1;
47 *sha1++ = val;
48 hex += 2;
49 }
50 return 0;
51 }
53 int safe_create_leading_directories(char *path)
54 {
55 char *pos = path;
56 struct stat st;
58 if (*pos == '/')
59 pos++;
61 while (pos) {
62 pos = strchr(pos, '/');
63 if (!pos)
64 break;
65 *pos = 0;
66 if (!stat(path, &st)) {
67 /* path exists */
68 if (!S_ISDIR(st.st_mode)) {
69 *pos = '/';
70 return -3;
71 }
72 }
73 else if (mkdir(path, 0777)) {
74 *pos = '/';
75 return -1;
76 }
77 else if (adjust_shared_perm(path)) {
78 *pos = '/';
79 return -2;
80 }
81 *pos++ = '/';
82 }
83 return 0;
84 }
86 char * sha1_to_hex(const unsigned char *sha1)
87 {
88 static int bufno;
89 static char hexbuffer[4][50];
90 static const char hex[] = "0123456789abcdef";
91 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
92 int i;
94 for (i = 0; i < 20; i++) {
95 unsigned int val = *sha1++;
96 *buf++ = hex[val >> 4];
97 *buf++ = hex[val & 0xf];
98 }
99 *buf = '\0';
101 return buffer;
102 }
104 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
105 {
106 int i;
107 for (i = 0; i < 20; i++) {
108 static char hex[] = "0123456789abcdef";
109 unsigned int val = sha1[i];
110 char *pos = pathbuf + i*2 + (i > 0);
111 *pos++ = hex[val >> 4];
112 *pos = hex[val & 0xf];
113 }
114 }
116 /*
117 * NOTE! This returns a statically allocated buffer, so you have to be
118 * careful about using it. Do a "strdup()" if you need to save the
119 * filename.
120 *
121 * Also note that this returns the location for creating. Reading
122 * SHA1 file can happen from any alternate directory listed in the
123 * DB_ENVIRONMENT environment variable if it is not found in
124 * the primary object database.
125 */
126 char *sha1_file_name(const unsigned char *sha1)
127 {
128 static char *name, *base;
130 if (!base) {
131 const char *sha1_file_directory = get_object_directory();
132 int len = strlen(sha1_file_directory);
133 base = xmalloc(len + 60);
134 memcpy(base, sha1_file_directory, len);
135 memset(base+len, 0, 60);
136 base[len] = '/';
137 base[len+3] = '/';
138 name = base + len + 1;
139 }
140 fill_sha1_path(name, sha1);
141 return base;
142 }
144 char *sha1_pack_name(const unsigned char *sha1)
145 {
146 static const char hex[] = "0123456789abcdef";
147 static char *name, *base, *buf;
148 int i;
150 if (!base) {
151 const char *sha1_file_directory = get_object_directory();
152 int len = strlen(sha1_file_directory);
153 base = xmalloc(len + 60);
154 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
155 name = base + len + 11;
156 }
158 buf = name;
160 for (i = 0; i < 20; i++) {
161 unsigned int val = *sha1++;
162 *buf++ = hex[val >> 4];
163 *buf++ = hex[val & 0xf];
164 }
166 return base;
167 }
169 char *sha1_pack_index_name(const unsigned char *sha1)
170 {
171 static const char hex[] = "0123456789abcdef";
172 static char *name, *base, *buf;
173 int i;
175 if (!base) {
176 const char *sha1_file_directory = get_object_directory();
177 int len = strlen(sha1_file_directory);
178 base = xmalloc(len + 60);
179 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
180 name = base + len + 11;
181 }
183 buf = name;
185 for (i = 0; i < 20; i++) {
186 unsigned int val = *sha1++;
187 *buf++ = hex[val >> 4];
188 *buf++ = hex[val & 0xf];
189 }
191 return base;
192 }
194 struct alternate_object_database *alt_odb_list;
195 static struct alternate_object_database **alt_odb_tail;
197 static void read_info_alternates(const char * alternates, int depth);
199 /*
200 * Prepare alternate object database registry.
201 *
202 * The variable alt_odb_list points at the list of struct
203 * alternate_object_database. The elements on this list come from
204 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
205 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
206 * whose contents is similar to that environment variable but can be
207 * LF separated. Its base points at a statically allocated buffer that
208 * contains "/the/directory/corresponding/to/.git/objects/...", while
209 * its name points just after the slash at the end of ".git/objects/"
210 * in the example above, and has enough space to hold 40-byte hex
211 * SHA1, an extra slash for the first level indirection, and the
212 * terminating NUL.
213 */
214 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
215 {
216 struct stat st;
217 const char *objdir = get_object_directory();
218 struct alternate_object_database *ent;
219 struct alternate_object_database *alt;
220 /* 43 = 40-byte + 2 '/' + terminating NUL */
221 int pfxlen = len;
222 int entlen = pfxlen + 43;
223 int base_len = -1;
225 if (*entry != '/' && relative_base) {
226 /* Relative alt-odb */
227 if (base_len < 0)
228 base_len = strlen(relative_base) + 1;
229 entlen += base_len;
230 pfxlen += base_len;
231 }
232 ent = xmalloc(sizeof(*ent) + entlen);
234 if (*entry != '/' && relative_base) {
235 memcpy(ent->base, relative_base, base_len - 1);
236 ent->base[base_len - 1] = '/';
237 memcpy(ent->base + base_len, entry, len);
238 }
239 else
240 memcpy(ent->base, entry, pfxlen);
242 ent->name = ent->base + pfxlen + 1;
243 ent->base[pfxlen + 3] = '/';
244 ent->base[pfxlen] = ent->base[entlen-1] = 0;
246 /* Detect cases where alternate disappeared */
247 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
248 error("object directory %s does not exist; "
249 "check .git/objects/info/alternates.",
250 ent->base);
251 free(ent);
252 return -1;
253 }
255 /* Prevent the common mistake of listing the same
256 * thing twice, or object directory itself.
257 */
258 for (alt = alt_odb_list; alt; alt = alt->next) {
259 if (!memcmp(ent->base, alt->base, pfxlen)) {
260 free(ent);
261 return -1;
262 }
263 }
264 if (!memcmp(ent->base, objdir, pfxlen)) {
265 free(ent);
266 return -1;
267 }
269 /* add the alternate entry */
270 *alt_odb_tail = ent;
271 alt_odb_tail = &(ent->next);
272 ent->next = NULL;
274 /* recursively add alternates */
275 read_info_alternates(ent->base, depth + 1);
277 ent->base[pfxlen] = '/';
279 return 0;
280 }
282 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
283 const char *relative_base, int depth)
284 {
285 const char *cp, *last;
287 if (depth > 5) {
288 error("%s: ignoring alternate object stores, nesting too deep.",
289 relative_base);
290 return;
291 }
293 last = alt;
294 while (last < ep) {
295 cp = last;
296 if (cp < ep && *cp == '#') {
297 while (cp < ep && *cp != sep)
298 cp++;
299 last = cp + 1;
300 continue;
301 }
302 while (cp < ep && *cp != sep)
303 cp++;
304 if (last != cp) {
305 if ((*last != '/') && depth) {
306 error("%s: ignoring relative alternate object store %s",
307 relative_base, last);
308 } else {
309 link_alt_odb_entry(last, cp - last,
310 relative_base, depth);
311 }
312 }
313 while (cp < ep && *cp == sep)
314 cp++;
315 last = cp;
316 }
317 }
319 static void read_info_alternates(const char * relative_base, int depth)
320 {
321 char *map;
322 struct stat st;
323 char path[PATH_MAX];
324 int fd;
326 sprintf(path, "%s/info/alternates", relative_base);
327 fd = open(path, O_RDONLY);
328 if (fd < 0)
329 return;
330 if (fstat(fd, &st) || (st.st_size == 0)) {
331 close(fd);
332 return;
333 }
334 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
335 close(fd);
336 if (map == MAP_FAILED)
337 return;
339 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
341 munmap(map, st.st_size);
342 }
344 void prepare_alt_odb(void)
345 {
346 const char *alt;
348 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
349 if (!alt) alt = "";
351 if (alt_odb_tail)
352 return;
353 alt_odb_tail = &alt_odb_list;
354 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
356 read_info_alternates(get_object_directory(), 0);
357 }
359 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
360 {
361 char *name = sha1_file_name(sha1);
362 struct alternate_object_database *alt;
364 if (!stat(name, st))
365 return name;
366 prepare_alt_odb();
367 for (alt = alt_odb_list; alt; alt = alt->next) {
368 name = alt->name;
369 fill_sha1_path(name, sha1);
370 if (!stat(alt->base, st))
371 return alt->base;
372 }
373 return NULL;
374 }
376 #define PACK_MAX_SZ (1<<26)
377 static int pack_used_ctr;
378 static unsigned long pack_mapped;
379 struct packed_git *packed_git;
381 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
382 void **idx_map_)
383 {
384 void *idx_map;
385 unsigned int *index;
386 unsigned long idx_size;
387 int nr, i;
388 int fd = open(path, O_RDONLY);
389 struct stat st;
390 if (fd < 0)
391 return -1;
392 if (fstat(fd, &st)) {
393 close(fd);
394 return -1;
395 }
396 idx_size = st.st_size;
397 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
398 close(fd);
399 if (idx_map == MAP_FAILED)
400 return -1;
402 index = idx_map;
403 *idx_map_ = idx_map;
404 *idx_size_ = idx_size;
406 /* check index map */
407 if (idx_size < 4*256 + 20 + 20)
408 return error("index file too small");
409 nr = 0;
410 for (i = 0; i < 256; i++) {
411 unsigned int n = ntohl(index[i]);
412 if (n < nr)
413 return error("non-monotonic index");
414 nr = n;
415 }
417 /*
418 * Total size:
419 * - 256 index entries 4 bytes each
420 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
421 * - 20-byte SHA1 of the packfile
422 * - 20-byte SHA1 file checksum
423 */
424 if (idx_size != 4*256 + nr * 24 + 20 + 20)
425 return error("wrong index file size");
427 return 0;
428 }
430 static int unuse_one_packed_git(void)
431 {
432 struct packed_git *p, *lru = NULL;
434 for (p = packed_git; p; p = p->next) {
435 if (p->pack_use_cnt || !p->pack_base)
436 continue;
437 if (!lru || p->pack_last_used < lru->pack_last_used)
438 lru = p;
439 }
440 if (!lru)
441 return 0;
442 munmap(lru->pack_base, lru->pack_size);
443 lru->pack_base = NULL;
444 return 1;
445 }
447 void unuse_packed_git(struct packed_git *p)
448 {
449 p->pack_use_cnt--;
450 }
452 int use_packed_git(struct packed_git *p)
453 {
454 if (!p->pack_size) {
455 struct stat st;
456 /* We created the struct before we had the pack */
457 stat(p->pack_name, &st);
458 if (!S_ISREG(st.st_mode))
459 die("packfile %s not a regular file", p->pack_name);
460 p->pack_size = st.st_size;
461 }
462 if (!p->pack_base) {
463 int fd;
464 struct stat st;
465 void *map;
466 struct pack_header *hdr;
468 pack_mapped += p->pack_size;
469 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
470 ; /* nothing */
471 fd = open(p->pack_name, O_RDONLY);
472 if (fd < 0)
473 die("packfile %s cannot be opened", p->pack_name);
474 if (fstat(fd, &st)) {
475 close(fd);
476 die("packfile %s cannot be opened", p->pack_name);
477 }
478 if (st.st_size != p->pack_size)
479 die("packfile %s size mismatch.", p->pack_name);
480 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
481 close(fd);
482 if (map == MAP_FAILED)
483 die("packfile %s cannot be mapped.", p->pack_name);
484 p->pack_base = map;
486 /* Check if we understand this pack file. If we don't we're
487 * likely too old to handle it.
488 */
489 hdr = map;
490 if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
491 die("packfile %s isn't actually a pack.", p->pack_name);
492 if (!pack_version_ok(hdr->hdr_version))
493 die("packfile %s is version %i and not supported"
494 " (try upgrading GIT to a newer version)",
495 p->pack_name, ntohl(hdr->hdr_version));
497 /* Check if the pack file matches with the index file.
498 * this is cheap.
499 */
500 if (hashcmp((unsigned char *)(p->index_base) +
501 p->index_size - 40,
502 (unsigned char *)p->pack_base +
503 p->pack_size - 20)) {
504 die("packfile %s does not match index.", p->pack_name);
505 }
506 }
507 p->pack_last_used = pack_used_ctr++;
508 p->pack_use_cnt++;
509 return 0;
510 }
512 struct packed_git *add_packed_git(char *path, int path_len, int local)
513 {
514 struct stat st;
515 struct packed_git *p;
516 unsigned long idx_size;
517 void *idx_map;
518 unsigned char sha1[20];
520 if (check_packed_git_idx(path, &idx_size, &idx_map))
521 return NULL;
523 /* do we have a corresponding .pack file? */
524 strcpy(path + path_len - 4, ".pack");
525 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
526 munmap(idx_map, idx_size);
527 return NULL;
528 }
529 /* ok, it looks sane as far as we can check without
530 * actually mapping the pack file.
531 */
532 p = xmalloc(sizeof(*p) + path_len + 2);
533 strcpy(p->pack_name, path);
534 p->index_size = idx_size;
535 p->pack_size = st.st_size;
536 p->index_base = idx_map;
537 p->next = NULL;
538 p->pack_base = NULL;
539 p->pack_last_used = 0;
540 p->pack_use_cnt = 0;
541 p->pack_local = local;
542 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
543 hashcpy(p->sha1, sha1);
544 return p;
545 }
547 struct packed_git *parse_pack_index(unsigned char *sha1)
548 {
549 char *path = sha1_pack_index_name(sha1);
550 return parse_pack_index_file(sha1, path);
551 }
553 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
554 {
555 struct packed_git *p;
556 unsigned long idx_size;
557 void *idx_map;
558 char *path;
560 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
561 return NULL;
563 path = sha1_pack_name(sha1);
565 p = xmalloc(sizeof(*p) + strlen(path) + 2);
566 strcpy(p->pack_name, path);
567 p->index_size = idx_size;
568 p->pack_size = 0;
569 p->index_base = idx_map;
570 p->next = NULL;
571 p->pack_base = NULL;
572 p->pack_last_used = 0;
573 p->pack_use_cnt = 0;
574 hashcpy(p->sha1, sha1);
575 return p;
576 }
578 void install_packed_git(struct packed_git *pack)
579 {
580 pack->next = packed_git;
581 packed_git = pack;
582 }
584 static void prepare_packed_git_one(char *objdir, int local)
585 {
586 char path[PATH_MAX];
587 int len;
588 DIR *dir;
589 struct dirent *de;
591 sprintf(path, "%s/pack", objdir);
592 len = strlen(path);
593 dir = opendir(path);
594 if (!dir) {
595 if (errno != ENOENT)
596 error("unable to open object pack directory: %s: %s",
597 path, strerror(errno));
598 return;
599 }
600 path[len++] = '/';
601 while ((de = readdir(dir)) != NULL) {
602 int namelen = strlen(de->d_name);
603 struct packed_git *p;
605 if (!has_extension(de->d_name, ".idx"))
606 continue;
608 /* we have .idx. Is it a file we can map? */
609 strcpy(path + len, de->d_name);
610 for (p = packed_git; p; p = p->next) {
611 if (!memcmp(path, p->pack_name, len + namelen - 4))
612 break;
613 }
614 if (p)
615 continue;
616 p = add_packed_git(path, len + namelen, local);
617 if (!p)
618 continue;
619 p->next = packed_git;
620 packed_git = p;
621 }
622 closedir(dir);
623 }
625 static int prepare_packed_git_run_once = 0;
626 void prepare_packed_git(void)
627 {
628 struct alternate_object_database *alt;
630 if (prepare_packed_git_run_once)
631 return;
632 prepare_packed_git_one(get_object_directory(), 1);
633 prepare_alt_odb();
634 for (alt = alt_odb_list; alt; alt = alt->next) {
635 alt->name[-1] = 0;
636 prepare_packed_git_one(alt->base, 0);
637 alt->name[-1] = '/';
638 }
639 prepare_packed_git_run_once = 1;
640 }
642 static void reprepare_packed_git(void)
643 {
644 prepare_packed_git_run_once = 0;
645 prepare_packed_git();
646 }
648 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
649 {
650 char header[100];
651 unsigned char real_sha1[20];
652 SHA_CTX c;
654 SHA1_Init(&c);
655 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
656 SHA1_Update(&c, map, size);
657 SHA1_Final(real_sha1, &c);
658 return hashcmp(sha1, real_sha1) ? -1 : 0;
659 }
661 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
662 {
663 struct stat st;
664 void *map;
665 int fd;
666 char *filename = find_sha1_file(sha1, &st);
668 if (!filename) {
669 return NULL;
670 }
672 fd = open(filename, O_RDONLY | sha1_file_open_flag);
673 if (fd < 0) {
674 /* See if it works without O_NOATIME */
675 switch (sha1_file_open_flag) {
676 default:
677 fd = open(filename, O_RDONLY);
678 if (fd >= 0)
679 break;
680 /* Fallthrough */
681 case 0:
682 return NULL;
683 }
685 /* If it failed once, it will probably fail again.
686 * Stop using O_NOATIME
687 */
688 sha1_file_open_flag = 0;
689 }
690 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
691 close(fd);
692 if (map == MAP_FAILED)
693 return NULL;
694 *size = st.st_size;
695 return map;
696 }
698 int legacy_loose_object(unsigned char *map)
699 {
700 unsigned int word;
702 /*
703 * Is it a zlib-compressed buffer? If so, the first byte
704 * must be 0x78 (15-bit window size, deflated), and the
705 * first 16-bit word is evenly divisible by 31
706 */
707 word = (map[0] << 8) + map[1];
708 if (map[0] == 0x78 && !(word % 31))
709 return 1;
710 else
711 return 0;
712 }
714 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
715 {
716 unsigned char c;
717 unsigned int bits;
718 unsigned long size;
719 static const char *typename[8] = {
720 NULL, /* OBJ_EXT */
721 "commit", "tree", "blob", "tag",
722 NULL, NULL, NULL
723 };
724 const char *type;
726 /* Get the data stream */
727 memset(stream, 0, sizeof(*stream));
728 stream->next_in = map;
729 stream->avail_in = mapsize;
730 stream->next_out = buffer;
731 stream->avail_out = bufsiz;
733 if (legacy_loose_object(map)) {
734 inflateInit(stream);
735 return inflate(stream, 0);
736 }
738 c = *map++;
739 mapsize--;
740 type = typename[(c >> 4) & 7];
741 if (!type)
742 return -1;
744 bits = 4;
745 size = c & 0xf;
746 while ((c & 0x80)) {
747 if (bits >= 8*sizeof(long))
748 return -1;
749 c = *map++;
750 size += (c & 0x7f) << bits;
751 bits += 7;
752 mapsize--;
753 }
755 /* Set up the stream for the rest.. */
756 stream->next_in = map;
757 stream->avail_in = mapsize;
758 inflateInit(stream);
760 /* And generate the fake traditional header */
761 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", type, size);
762 return 0;
763 }
765 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
766 {
767 int bytes = strlen(buffer) + 1;
768 unsigned char *buf = xmalloc(1+size);
769 unsigned long n;
771 n = stream->total_out - bytes;
772 if (n > size)
773 n = size;
774 memcpy(buf, (char *) buffer + bytes, n);
775 bytes = n;
776 if (bytes < size) {
777 stream->next_out = buf + bytes;
778 stream->avail_out = size - bytes;
779 while (inflate(stream, Z_FINISH) == Z_OK)
780 /* nothing */;
781 }
782 buf[size] = 0;
783 inflateEnd(stream);
784 return buf;
785 }
787 /*
788 * We used to just use "sscanf()", but that's actually way
789 * too permissive for what we want to check. So do an anal
790 * object header parse by hand.
791 */
792 static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
793 {
794 int i;
795 unsigned long size;
797 /*
798 * The type can be at most ten bytes (including the
799 * terminating '\0' that we add), and is followed by
800 * a space.
801 */
802 i = 10;
803 for (;;) {
804 char c = *hdr++;
805 if (c == ' ')
806 break;
807 if (!--i)
808 return -1;
809 *type++ = c;
810 }
811 *type = 0;
813 /*
814 * The length must follow immediately, and be in canonical
815 * decimal format (ie "010" is not valid).
816 */
817 size = *hdr++ - '0';
818 if (size > 9)
819 return -1;
820 if (size) {
821 for (;;) {
822 unsigned long c = *hdr - '0';
823 if (c > 9)
824 break;
825 hdr++;
826 size = size * 10 + c;
827 }
828 }
829 *sizep = size;
831 /*
832 * The length must be followed by a zero byte
833 */
834 return *hdr ? -1 : 0;
835 }
837 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
838 {
839 int ret;
840 z_stream stream;
841 char hdr[8192];
843 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
844 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
845 return NULL;
847 return unpack_sha1_rest(&stream, hdr, *size);
848 }
850 /* forward declaration for a mutually recursive function */
851 static int packed_object_info(struct pack_entry *entry,
852 char *type, unsigned long *sizep);
854 static int packed_delta_info(unsigned char *base_sha1,
855 unsigned long delta_size,
856 unsigned long left,
857 char *type,
858 unsigned long *sizep,
859 struct packed_git *p)
860 {
861 struct pack_entry base_ent;
863 if (left < 20)
864 die("truncated pack file");
866 /* The base entry _must_ be in the same pack */
867 if (!find_pack_entry_one(base_sha1, &base_ent, p))
868 die("failed to find delta-pack base object %s",
869 sha1_to_hex(base_sha1));
871 /* We choose to only get the type of the base object and
872 * ignore potentially corrupt pack file that expects the delta
873 * based on a base with a wrong size. This saves tons of
874 * inflate() calls.
875 */
877 if (packed_object_info(&base_ent, type, NULL))
878 die("cannot get info for delta-pack base");
880 if (sizep) {
881 const unsigned char *data;
882 unsigned char delta_head[64];
883 unsigned long result_size;
884 z_stream stream;
885 int st;
887 memset(&stream, 0, sizeof(stream));
889 data = stream.next_in = base_sha1 + 20;
890 stream.avail_in = left - 20;
891 stream.next_out = delta_head;
892 stream.avail_out = sizeof(delta_head);
894 inflateInit(&stream);
895 st = inflate(&stream, Z_FINISH);
896 inflateEnd(&stream);
897 if ((st != Z_STREAM_END) &&
898 stream.total_out != sizeof(delta_head))
899 die("delta data unpack-initial failed");
901 /* Examine the initial part of the delta to figure out
902 * the result size.
903 */
904 data = delta_head;
906 /* ignore base size */
907 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
909 /* Read the result size */
910 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
911 *sizep = result_size;
912 }
913 return 0;
914 }
916 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
917 enum object_type *type, unsigned long *sizep)
918 {
919 unsigned shift;
920 unsigned char *pack, c;
921 unsigned long size;
923 if (offset >= p->pack_size)
924 die("object offset outside of pack file");
926 pack = (unsigned char *) p->pack_base + offset;
927 c = *pack++;
928 offset++;
929 *type = (c >> 4) & 7;
930 size = c & 15;
931 shift = 4;
932 while (c & 0x80) {
933 if (offset >= p->pack_size)
934 die("object offset outside of pack file");
935 c = *pack++;
936 offset++;
937 size += (c & 0x7f) << shift;
938 shift += 7;
939 }
940 *sizep = size;
941 return offset;
942 }
944 int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
945 unsigned char *base, unsigned long *sizep,
946 enum object_type *kindp)
947 {
948 unsigned long ptr;
949 int status = -1;
951 use_packed_git(p);
952 ptr = offset;
953 ptr = unpack_object_header(p, ptr, kindp, sizep);
954 if (*kindp != OBJ_DELTA)
955 goto done;
956 hashcpy(base, (unsigned char *) p->pack_base + ptr);
957 status = 0;
958 done:
959 unuse_packed_git(p);
960 return status;
961 }
963 void packed_object_info_detail(struct pack_entry *e,
964 char *type,
965 unsigned long *size,
966 unsigned long *store_size,
967 unsigned int *delta_chain_length,
968 unsigned char *base_sha1)
969 {
970 struct packed_git *p = e->p;
971 unsigned long offset;
972 unsigned char *pack;
973 enum object_type kind;
975 offset = unpack_object_header(p, e->offset, &kind, size);
976 pack = (unsigned char *) p->pack_base + offset;
977 if (kind != OBJ_DELTA)
978 *delta_chain_length = 0;
979 else {
980 unsigned int chain_length = 0;
981 if (p->pack_size <= offset + 20)
982 die("pack file %s records an incomplete delta base",
983 p->pack_name);
984 hashcpy(base_sha1, pack);
985 do {
986 struct pack_entry base_ent;
987 unsigned long junk;
989 find_pack_entry_one(pack, &base_ent, p);
990 offset = unpack_object_header(p, base_ent.offset,
991 &kind, &junk);
992 pack = (unsigned char *) p->pack_base + offset;
993 chain_length++;
994 } while (kind == OBJ_DELTA);
995 *delta_chain_length = chain_length;
996 }
997 switch (kind) {
998 case OBJ_COMMIT:
999 strcpy(type, commit_type);
1000 break;
1001 case OBJ_TREE:
1002 strcpy(type, tree_type);
1003 break;
1004 case OBJ_BLOB:
1005 strcpy(type, blob_type);
1006 break;
1007 case OBJ_TAG:
1008 strcpy(type, tag_type);
1009 break;
1010 default:
1011 die("corrupted pack file %s containing object of kind %d",
1012 p->pack_name, kind);
1013 }
1014 *store_size = 0; /* notyet */
1015 }
1017 static int packed_object_info(struct pack_entry *entry,
1018 char *type, unsigned long *sizep)
1019 {
1020 struct packed_git *p = entry->p;
1021 unsigned long offset, size, left;
1022 unsigned char *pack;
1023 enum object_type kind;
1024 int retval;
1026 if (use_packed_git(p))
1027 die("cannot map packed file");
1029 offset = unpack_object_header(p, entry->offset, &kind, &size);
1030 pack = (unsigned char *) p->pack_base + offset;
1031 left = p->pack_size - offset;
1033 switch (kind) {
1034 case OBJ_DELTA:
1035 retval = packed_delta_info(pack, size, left, type, sizep, p);
1036 unuse_packed_git(p);
1037 return retval;
1038 case OBJ_COMMIT:
1039 strcpy(type, commit_type);
1040 break;
1041 case OBJ_TREE:
1042 strcpy(type, tree_type);
1043 break;
1044 case OBJ_BLOB:
1045 strcpy(type, blob_type);
1046 break;
1047 case OBJ_TAG:
1048 strcpy(type, tag_type);
1049 break;
1050 default:
1051 die("corrupted pack file %s containing object of kind %d",
1052 p->pack_name, kind);
1053 }
1054 if (sizep)
1055 *sizep = size;
1056 unuse_packed_git(p);
1057 return 0;
1058 }
1060 static void *unpack_compressed_entry(unsigned char *data,
1061 unsigned long size,
1062 unsigned long left)
1063 {
1064 int st;
1065 z_stream stream;
1066 unsigned char *buffer;
1068 buffer = xmalloc(size + 1);
1069 buffer[size] = 0;
1070 memset(&stream, 0, sizeof(stream));
1071 stream.next_in = data;
1072 stream.avail_in = left;
1073 stream.next_out = buffer;
1074 stream.avail_out = size;
1076 inflateInit(&stream);
1077 st = inflate(&stream, Z_FINISH);
1078 inflateEnd(&stream);
1079 if ((st != Z_STREAM_END) || stream.total_out != size) {
1080 free(buffer);
1081 return NULL;
1082 }
1084 return buffer;
1085 }
1087 static void *unpack_delta_entry(unsigned char *base_sha1,
1088 unsigned long delta_size,
1089 unsigned long left,
1090 char *type,
1091 unsigned long *sizep,
1092 struct packed_git *p)
1093 {
1094 struct pack_entry base_ent;
1095 void *delta_data, *result, *base;
1096 unsigned long result_size, base_size;
1098 if (left < 20)
1099 die("truncated pack file");
1101 /* The base entry _must_ be in the same pack */
1102 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1103 die("failed to find delta-pack base object %s",
1104 sha1_to_hex(base_sha1));
1105 base = unpack_entry_gently(&base_ent, type, &base_size);
1106 if (!base)
1107 die("failed to read delta-pack base object %s",
1108 sha1_to_hex(base_sha1));
1110 delta_data = unpack_compressed_entry(base_sha1 + 20,
1111 delta_size, left - 20);
1112 result = patch_delta(base, base_size,
1113 delta_data, delta_size,
1114 &result_size);
1115 if (!result)
1116 die("failed to apply delta");
1117 free(delta_data);
1118 free(base);
1119 *sizep = result_size;
1120 return result;
1121 }
1123 static void *unpack_entry(struct pack_entry *entry,
1124 char *type, unsigned long *sizep)
1125 {
1126 struct packed_git *p = entry->p;
1127 void *retval;
1129 if (use_packed_git(p))
1130 die("cannot map packed file");
1131 retval = unpack_entry_gently(entry, type, sizep);
1132 unuse_packed_git(p);
1133 if (!retval)
1134 die("corrupted pack file %s", p->pack_name);
1135 return retval;
1136 }
1138 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1139 void *unpack_entry_gently(struct pack_entry *entry,
1140 char *type, unsigned long *sizep)
1141 {
1142 struct packed_git *p = entry->p;
1143 unsigned long offset, size, left;
1144 unsigned char *pack;
1145 enum object_type kind;
1146 void *retval;
1148 offset = unpack_object_header(p, entry->offset, &kind, &size);
1149 pack = (unsigned char *) p->pack_base + offset;
1150 left = p->pack_size - offset;
1151 switch (kind) {
1152 case OBJ_DELTA:
1153 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
1154 return retval;
1155 case OBJ_COMMIT:
1156 strcpy(type, commit_type);
1157 break;
1158 case OBJ_TREE:
1159 strcpy(type, tree_type);
1160 break;
1161 case OBJ_BLOB:
1162 strcpy(type, blob_type);
1163 break;
1164 case OBJ_TAG:
1165 strcpy(type, tag_type);
1166 break;
1167 default:
1168 return NULL;
1169 }
1170 *sizep = size;
1171 retval = unpack_compressed_entry(pack, size, left);
1172 return retval;
1173 }
1175 int num_packed_objects(const struct packed_git *p)
1176 {
1177 /* See check_packed_git_idx() */
1178 return (p->index_size - 20 - 20 - 4*256) / 24;
1179 }
1181 int nth_packed_object_sha1(const struct packed_git *p, int n,
1182 unsigned char* sha1)
1183 {
1184 void *index = p->index_base + 256;
1185 if (n < 0 || num_packed_objects(p) <= n)
1186 return -1;
1187 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1188 return 0;
1189 }
1191 int find_pack_entry_one(const unsigned char *sha1,
1192 struct pack_entry *e, struct packed_git *p)
1193 {
1194 unsigned int *level1_ofs = p->index_base;
1195 int hi = ntohl(level1_ofs[*sha1]);
1196 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1197 void *index = p->index_base + 256;
1199 do {
1200 int mi = (lo + hi) / 2;
1201 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1202 if (!cmp) {
1203 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1204 hashcpy(e->sha1, sha1);
1205 e->p = p;
1206 return 1;
1207 }
1208 if (cmp > 0)
1209 hi = mi;
1210 else
1211 lo = mi+1;
1212 } while (lo < hi);
1213 return 0;
1214 }
1216 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1217 {
1218 struct packed_git *p;
1219 prepare_packed_git();
1221 for (p = packed_git; p; p = p->next) {
1222 if (find_pack_entry_one(sha1, e, p))
1223 return 1;
1224 }
1225 return 0;
1226 }
1228 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1229 struct packed_git *packs)
1230 {
1231 struct packed_git *p;
1232 struct pack_entry e;
1234 for (p = packs; p; p = p->next) {
1235 if (find_pack_entry_one(sha1, &e, p))
1236 return p;
1237 }
1238 return NULL;
1240 }
1242 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1243 {
1244 int status;
1245 unsigned long mapsize, size;
1246 void *map;
1247 z_stream stream;
1248 char hdr[128];
1250 map = map_sha1_file(sha1, &mapsize);
1251 if (!map) {
1252 struct pack_entry e;
1254 if (find_pack_entry(sha1, &e))
1255 return packed_object_info(&e, type, sizep);
1256 reprepare_packed_git();
1257 if (find_pack_entry(sha1, &e))
1258 return packed_object_info(&e, type, sizep);
1259 return error("unable to find %s", sha1_to_hex(sha1));
1260 }
1261 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1262 status = error("unable to unpack %s header",
1263 sha1_to_hex(sha1));
1264 if (parse_sha1_header(hdr, type, &size) < 0)
1265 status = error("unable to parse %s header", sha1_to_hex(sha1));
1266 else {
1267 status = 0;
1268 if (sizep)
1269 *sizep = size;
1270 }
1271 inflateEnd(&stream);
1272 munmap(map, mapsize);
1273 return status;
1274 }
1276 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1277 {
1278 struct pack_entry e;
1280 if (!find_pack_entry(sha1, &e)) {
1281 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1282 return NULL;
1283 }
1284 return unpack_entry(&e, type, size);
1285 }
1287 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1288 {
1289 unsigned long mapsize;
1290 void *map, *buf;
1291 struct pack_entry e;
1293 if (find_pack_entry(sha1, &e))
1294 return read_packed_sha1(sha1, type, size);
1295 map = map_sha1_file(sha1, &mapsize);
1296 if (map) {
1297 buf = unpack_sha1_file(map, mapsize, type, size);
1298 munmap(map, mapsize);
1299 return buf;
1300 }
1301 reprepare_packed_git();
1302 if (find_pack_entry(sha1, &e))
1303 return read_packed_sha1(sha1, type, size);
1304 return NULL;
1305 }
1307 void *read_object_with_reference(const unsigned char *sha1,
1308 const char *required_type,
1309 unsigned long *size,
1310 unsigned char *actual_sha1_return)
1311 {
1312 char type[20];
1313 void *buffer;
1314 unsigned long isize;
1315 unsigned char actual_sha1[20];
1317 hashcpy(actual_sha1, sha1);
1318 while (1) {
1319 int ref_length = -1;
1320 const char *ref_type = NULL;
1322 buffer = read_sha1_file(actual_sha1, type, &isize);
1323 if (!buffer)
1324 return NULL;
1325 if (!strcmp(type, required_type)) {
1326 *size = isize;
1327 if (actual_sha1_return)
1328 hashcpy(actual_sha1_return, actual_sha1);
1329 return buffer;
1330 }
1331 /* Handle references */
1332 else if (!strcmp(type, commit_type))
1333 ref_type = "tree ";
1334 else if (!strcmp(type, tag_type))
1335 ref_type = "object ";
1336 else {
1337 free(buffer);
1338 return NULL;
1339 }
1340 ref_length = strlen(ref_type);
1342 if (memcmp(buffer, ref_type, ref_length) ||
1343 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1344 free(buffer);
1345 return NULL;
1346 }
1347 free(buffer);
1348 /* Now we have the ID of the referred-to object in
1349 * actual_sha1. Check again. */
1350 }
1351 }
1353 char *write_sha1_file_prepare(void *buf,
1354 unsigned long len,
1355 const char *type,
1356 unsigned char *sha1,
1357 unsigned char *hdr,
1358 int *hdrlen)
1359 {
1360 SHA_CTX c;
1362 /* Generate the header */
1363 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1365 /* Sha1.. */
1366 SHA1_Init(&c);
1367 SHA1_Update(&c, hdr, *hdrlen);
1368 SHA1_Update(&c, buf, len);
1369 SHA1_Final(sha1, &c);
1371 return sha1_file_name(sha1);
1372 }
1374 /*
1375 * Link the tempfile to the final place, possibly creating the
1376 * last directory level as you do so.
1377 *
1378 * Returns the errno on failure, 0 on success.
1379 */
1380 static int link_temp_to_file(const char *tmpfile, char *filename)
1381 {
1382 int ret;
1383 char *dir;
1385 if (!link(tmpfile, filename))
1386 return 0;
1388 /*
1389 * Try to mkdir the last path component if that failed.
1390 *
1391 * Re-try the "link()" regardless of whether the mkdir
1392 * succeeds, since a race might mean that somebody
1393 * else succeeded.
1394 */
1395 ret = errno;
1396 dir = strrchr(filename, '/');
1397 if (dir) {
1398 *dir = 0;
1399 mkdir(filename, 0777);
1400 if (adjust_shared_perm(filename))
1401 return -2;
1402 *dir = '/';
1403 if (!link(tmpfile, filename))
1404 return 0;
1405 ret = errno;
1406 }
1407 return ret;
1408 }
1410 /*
1411 * Move the just written object into its final resting place
1412 */
1413 int move_temp_to_file(const char *tmpfile, char *filename)
1414 {
1415 int ret = link_temp_to_file(tmpfile, filename);
1417 /*
1418 * Coda hack - coda doesn't like cross-directory links,
1419 * so we fall back to a rename, which will mean that it
1420 * won't be able to check collisions, but that's not a
1421 * big deal.
1422 *
1423 * The same holds for FAT formatted media.
1424 *
1425 * When this succeeds, we just return 0. We have nothing
1426 * left to unlink.
1427 */
1428 if (ret && ret != EEXIST) {
1429 if (!rename(tmpfile, filename))
1430 return 0;
1431 ret = errno;
1432 }
1433 unlink(tmpfile);
1434 if (ret) {
1435 if (ret != EEXIST) {
1436 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1437 return -1;
1438 }
1439 /* FIXME!!! Collision check here ? */
1440 }
1442 return 0;
1443 }
1445 static int write_buffer(int fd, const void *buf, size_t len)
1446 {
1447 while (len) {
1448 ssize_t size;
1450 size = write(fd, buf, len);
1451 if (!size)
1452 return error("file write: disk full");
1453 if (size < 0) {
1454 if (errno == EINTR || errno == EAGAIN)
1455 continue;
1456 return error("file write error (%s)", strerror(errno));
1457 }
1458 len -= size;
1459 buf = (char *) buf + size;
1460 }
1461 return 0;
1462 }
1464 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1465 {
1466 int hdr_len;
1467 unsigned char c;
1469 c = (type << 4) | (len & 15);
1470 len >>= 4;
1471 hdr_len = 1;
1472 while (len) {
1473 *hdr++ = c | 0x80;
1474 hdr_len++;
1475 c = (len & 0x7f);
1476 len >>= 7;
1477 }
1478 *hdr = c;
1479 return hdr_len;
1480 }
1482 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1483 {
1484 int obj_type, hdr;
1486 if (use_legacy_headers) {
1487 while (deflate(stream, 0) == Z_OK)
1488 /* nothing */;
1489 return;
1490 }
1491 if (!strcmp(type, blob_type))
1492 obj_type = OBJ_BLOB;
1493 else if (!strcmp(type, tree_type))
1494 obj_type = OBJ_TREE;
1495 else if (!strcmp(type, commit_type))
1496 obj_type = OBJ_COMMIT;
1497 else if (!strcmp(type, tag_type))
1498 obj_type = OBJ_TAG;
1499 else
1500 die("trying to generate bogus object of type '%s'", type);
1501 hdr = write_binary_header(stream->next_out, obj_type, len);
1502 stream->total_out = hdr;
1503 stream->next_out += hdr;
1504 stream->avail_out -= hdr;
1505 }
1507 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1508 {
1509 int size;
1510 unsigned char *compressed;
1511 z_stream stream;
1512 unsigned char sha1[20];
1513 char *filename;
1514 static char tmpfile[PATH_MAX];
1515 unsigned char hdr[50];
1516 int fd, hdrlen;
1518 /* Normally if we have it in the pack then we do not bother writing
1519 * it out into .git/objects/??/?{38} file.
1520 */
1521 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1522 if (returnsha1)
1523 hashcpy(returnsha1, sha1);
1524 if (has_sha1_file(sha1))
1525 return 0;
1526 fd = open(filename, O_RDONLY);
1527 if (fd >= 0) {
1528 /*
1529 * FIXME!!! We might do collision checking here, but we'd
1530 * need to uncompress the old file and check it. Later.
1531 */
1532 close(fd);
1533 return 0;
1534 }
1536 if (errno != ENOENT) {
1537 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1538 return -1;
1539 }
1541 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1543 fd = mkstemp(tmpfile);
1544 if (fd < 0) {
1545 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1546 return -1;
1547 }
1549 /* Set it up */
1550 memset(&stream, 0, sizeof(stream));
1551 deflateInit(&stream, zlib_compression_level);
1552 size = 8 + deflateBound(&stream, len+hdrlen);
1553 compressed = xmalloc(size);
1555 /* Compress it */
1556 stream.next_out = compressed;
1557 stream.avail_out = size;
1559 /* First header.. */
1560 stream.next_in = hdr;
1561 stream.avail_in = hdrlen;
1562 setup_object_header(&stream, type, len);
1564 /* Then the data itself.. */
1565 stream.next_in = buf;
1566 stream.avail_in = len;
1567 while (deflate(&stream, Z_FINISH) == Z_OK)
1568 /* nothing */;
1569 deflateEnd(&stream);
1570 size = stream.total_out;
1572 if (write_buffer(fd, compressed, size) < 0)
1573 die("unable to write sha1 file");
1574 fchmod(fd, 0444);
1575 close(fd);
1576 free(compressed);
1578 return move_temp_to_file(tmpfile, filename);
1579 }
1581 /*
1582 * We need to unpack and recompress the object for writing
1583 * it out to a different file.
1584 */
1585 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1586 {
1587 size_t size;
1588 z_stream stream;
1589 unsigned char *unpacked;
1590 unsigned long len;
1591 char type[20];
1592 char hdr[50];
1593 int hdrlen;
1594 void *buf;
1596 /* need to unpack and recompress it by itself */
1597 unpacked = read_packed_sha1(sha1, type, &len);
1599 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1601 /* Set it up */
1602 memset(&stream, 0, sizeof(stream));
1603 deflateInit(&stream, zlib_compression_level);
1604 size = deflateBound(&stream, len + hdrlen);
1605 buf = xmalloc(size);
1607 /* Compress it */
1608 stream.next_out = buf;
1609 stream.avail_out = size;
1611 /* First header.. */
1612 stream.next_in = (void *)hdr;
1613 stream.avail_in = hdrlen;
1614 while (deflate(&stream, 0) == Z_OK)
1615 /* nothing */;
1617 /* Then the data itself.. */
1618 stream.next_in = unpacked;
1619 stream.avail_in = len;
1620 while (deflate(&stream, Z_FINISH) == Z_OK)
1621 /* nothing */;
1622 deflateEnd(&stream);
1623 free(unpacked);
1625 *objsize = stream.total_out;
1626 return buf;
1627 }
1629 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1630 {
1631 int retval;
1632 unsigned long objsize;
1633 void *buf = map_sha1_file(sha1, &objsize);
1635 if (buf) {
1636 retval = write_buffer(fd, buf, objsize);
1637 munmap(buf, objsize);
1638 return retval;
1639 }
1641 buf = repack_object(sha1, &objsize);
1642 retval = write_buffer(fd, buf, objsize);
1643 free(buf);
1644 return retval;
1645 }
1647 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1648 size_t bufsize, size_t *bufposn)
1649 {
1650 char tmpfile[PATH_MAX];
1651 int local;
1652 z_stream stream;
1653 unsigned char real_sha1[20];
1654 unsigned char discard[4096];
1655 int ret;
1656 SHA_CTX c;
1658 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1660 local = mkstemp(tmpfile);
1661 if (local < 0)
1662 return error("Couldn't open %s for %s",
1663 tmpfile, sha1_to_hex(sha1));
1665 memset(&stream, 0, sizeof(stream));
1667 inflateInit(&stream);
1669 SHA1_Init(&c);
1671 do {
1672 ssize_t size;
1673 if (*bufposn) {
1674 stream.avail_in = *bufposn;
1675 stream.next_in = (unsigned char *) buffer;
1676 do {
1677 stream.next_out = discard;
1678 stream.avail_out = sizeof(discard);
1679 ret = inflate(&stream, Z_SYNC_FLUSH);
1680 SHA1_Update(&c, discard, sizeof(discard) -
1681 stream.avail_out);
1682 } while (stream.avail_in && ret == Z_OK);
1683 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1684 die("unable to write sha1 file");
1685 memmove(buffer, buffer + *bufposn - stream.avail_in,
1686 stream.avail_in);
1687 *bufposn = stream.avail_in;
1688 if (ret != Z_OK)
1689 break;
1690 }
1691 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1692 if (size <= 0) {
1693 close(local);
1694 unlink(tmpfile);
1695 if (!size)
1696 return error("Connection closed?");
1697 perror("Reading from connection");
1698 return -1;
1699 }
1700 *bufposn += size;
1701 } while (1);
1702 inflateEnd(&stream);
1704 close(local);
1705 SHA1_Final(real_sha1, &c);
1706 if (ret != Z_STREAM_END) {
1707 unlink(tmpfile);
1708 return error("File %s corrupted", sha1_to_hex(sha1));
1709 }
1710 if (hashcmp(sha1, real_sha1)) {
1711 unlink(tmpfile);
1712 return error("File %s has bad hash", sha1_to_hex(sha1));
1713 }
1715 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1716 }
1718 int has_pack_index(const unsigned char *sha1)
1719 {
1720 struct stat st;
1721 if (stat(sha1_pack_index_name(sha1), &st))
1722 return 0;
1723 return 1;
1724 }
1726 int has_pack_file(const unsigned char *sha1)
1727 {
1728 struct stat st;
1729 if (stat(sha1_pack_name(sha1), &st))
1730 return 0;
1731 return 1;
1732 }
1734 int has_sha1_pack(const unsigned char *sha1)
1735 {
1736 struct pack_entry e;
1737 return find_pack_entry(sha1, &e);
1738 }
1740 int has_sha1_file(const unsigned char *sha1)
1741 {
1742 struct stat st;
1743 struct pack_entry e;
1745 if (find_pack_entry(sha1, &e))
1746 return 1;
1747 return find_sha1_file(sha1, &st) ? 1 : 0;
1748 }
1750 /*
1751 * reads from fd as long as possible into a supplied buffer of size bytes.
1752 * If necessary the buffer's size is increased using realloc()
1753 *
1754 * returns 0 if anything went fine and -1 otherwise
1755 *
1756 * NOTE: both buf and size may change, but even when -1 is returned
1757 * you still have to free() it yourself.
1758 */
1759 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1760 {
1761 char* buf = *return_buf;
1762 unsigned long size = *return_size;
1763 int iret;
1764 unsigned long off = 0;
1766 do {
1767 iret = xread(fd, buf + off, size - off);
1768 if (iret > 0) {
1769 off += iret;
1770 if (off == size) {
1771 size *= 2;
1772 buf = realloc(buf, size);
1773 }
1774 }
1775 } while (iret > 0);
1777 *return_buf = buf;
1778 *return_size = off;
1780 if (iret < 0)
1781 return -1;
1782 return 0;
1783 }
1785 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1786 {
1787 unsigned long size = 4096;
1788 char *buf = malloc(size);
1789 int ret;
1790 unsigned char hdr[50];
1791 int hdrlen;
1793 if (read_pipe(fd, &buf, &size)) {
1794 free(buf);
1795 return -1;
1796 }
1798 if (!type)
1799 type = blob_type;
1800 if (write_object)
1801 ret = write_sha1_file(buf, size, type, sha1);
1802 else {
1803 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1804 ret = 0;
1805 }
1806 free(buf);
1807 return ret;
1808 }
1810 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1811 {
1812 unsigned long size = st->st_size;
1813 void *buf;
1814 int ret;
1815 unsigned char hdr[50];
1816 int hdrlen;
1818 buf = "";
1819 if (size)
1820 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1821 close(fd);
1822 if (buf == MAP_FAILED)
1823 return -1;
1825 if (!type)
1826 type = blob_type;
1827 if (write_object)
1828 ret = write_sha1_file(buf, size, type, sha1);
1829 else {
1830 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1831 ret = 0;
1832 }
1833 if (size)
1834 munmap(buf, size);
1835 return ret;
1836 }
1838 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1839 {
1840 int fd;
1841 char *target;
1843 switch (st->st_mode & S_IFMT) {
1844 case S_IFREG:
1845 fd = open(path, O_RDONLY);
1846 if (fd < 0)
1847 return error("open(\"%s\"): %s", path,
1848 strerror(errno));
1849 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1850 return error("%s: failed to insert into database",
1851 path);
1852 break;
1853 case S_IFLNK:
1854 target = xmalloc(st->st_size+1);
1855 if (readlink(path, target, st->st_size+1) != st->st_size) {
1856 char *errstr = strerror(errno);
1857 free(target);
1858 return error("readlink(\"%s\"): %s", path,
1859 errstr);
1860 }
1861 if (!write_object) {
1862 unsigned char hdr[50];
1863 int hdrlen;
1864 write_sha1_file_prepare(target, st->st_size, blob_type,
1865 sha1, hdr, &hdrlen);
1866 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1867 return error("%s: failed to insert into database",
1868 path);
1869 free(target);
1870 break;
1871 default:
1872 return error("%s: unsupported file type", path);
1873 }
1874 return 0;
1875 }