pack-objects --unpacked=<existing pack> option.
[git/git.git] / sha1_file.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "delta.h"
11 #include "pack.h"
12 #include "blob.h"
13 #include "commit.h"
14 #include "tag.h"
15 #include "tree.h"
16
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
24
25 const unsigned char null_sha1[20];
26
27 static unsigned int sha1_file_open_flag = O_NOATIME;
28
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 }
39
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 }
52
53 int safe_create_leading_directories(char *path)
54 {
55 char *pos = path;
56 struct stat st;
57
58 if (*pos == '/')
59 pos++;
60
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 }
85
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;
93
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';
100
101 return buffer;
102 }
103
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 }
115
116 /*
117 * NOTE! This returns a statically allocated buffer, so you have to be
118 * careful about using it. Do a "xstrdup()" 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;
129
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 }
143
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;
149
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 }
157
158 buf = name;
159
160 for (i = 0; i < 20; i++) {
161 unsigned int val = *sha1++;
162 *buf++ = hex[val >> 4];
163 *buf++ = hex[val & 0xf];
164 }
165
166 return base;
167 }
168
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;
174
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 }
182
183 buf = name;
184
185 for (i = 0; i < 20; i++) {
186 unsigned int val = *sha1++;
187 *buf++ = hex[val >> 4];
188 *buf++ = hex[val & 0xf];
189 }
190
191 return base;
192 }
193
194 struct alternate_object_database *alt_odb_list;
195 static struct alternate_object_database **alt_odb_tail;
196
197 static void read_info_alternates(const char * alternates, int depth);
198
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;
224
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);
233
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);
241
242 ent->name = ent->base + pfxlen + 1;
243 ent->base[pfxlen + 3] = '/';
244 ent->base[pfxlen] = ent->base[entlen-1] = 0;
245
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 }
254
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 }
268
269 /* add the alternate entry */
270 *alt_odb_tail = ent;
271 alt_odb_tail = &(ent->next);
272 ent->next = NULL;
273
274 /* recursively add alternates */
275 read_info_alternates(ent->base, depth + 1);
276
277 ent->base[pfxlen] = '/';
278
279 return 0;
280 }
281
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;
286
287 if (depth > 5) {
288 error("%s: ignoring alternate object stores, nesting too deep.",
289 relative_base);
290 return;
291 }
292
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 }
318
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;
325
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;
338
339 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
340
341 munmap(map, st.st_size);
342 }
343
344 void prepare_alt_odb(void)
345 {
346 const char *alt;
347
348 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
349 if (!alt) alt = "";
350
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);
355
356 read_info_alternates(get_object_directory(), 0);
357 }
358
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;
363
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 }
375
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;
380
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;
401
402 index = idx_map;
403 *idx_map_ = idx_map;
404 *idx_size_ = idx_size;
405
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 }
416
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");
426
427 return 0;
428 }
429
430 static int unuse_one_packed_git(void)
431 {
432 struct packed_git *p, *lru = NULL;
433
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 }
446
447 void unuse_packed_git(struct packed_git *p)
448 {
449 p->pack_use_cnt--;
450 }
451
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;
467
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;
485
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));
496
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 }
511
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];
519
520 if (check_packed_git_idx(path, &idx_size, &idx_map))
521 return NULL;
522
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 }
546
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 }
552
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;
559
560 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
561 return NULL;
562
563 path = sha1_pack_name(sha1);
564
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 }
577
578 void install_packed_git(struct packed_git *pack)
579 {
580 pack->next = packed_git;
581 packed_git = pack;
582 }
583
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;
590
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;
604
605 if (!has_extension(de->d_name, ".idx"))
606 continue;
607
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 }
624
625 static int prepare_packed_git_run_once = 0;
626 void prepare_packed_git(void)
627 {
628 struct alternate_object_database *alt;
629
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 }
641
642 static void reprepare_packed_git(void)
643 {
644 prepare_packed_git_run_once = 0;
645 prepare_packed_git();
646 }
647
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;
653
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 }
660
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);
667
668 if (!filename) {
669 return NULL;
670 }
671
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 }
684
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 }
697
698 int legacy_loose_object(unsigned char *map)
699 {
700 unsigned int word;
701
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 }
713
714 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
715 {
716 unsigned shift;
717 unsigned char c;
718 unsigned long size;
719 unsigned long used = 0;
720
721 c = buf[used++];
722 *type = (c >> 4) & 7;
723 size = c & 15;
724 shift = 4;
725 while (c & 0x80) {
726 if (len <= used)
727 return 0;
728 if (sizeof(long) * 8 <= shift)
729 return 0;
730 c = buf[used++];
731 size += (c & 0x7f) << shift;
732 shift += 7;
733 }
734 *sizep = size;
735 return used;
736 }
737
738 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
739 {
740 unsigned long size, used;
741 static const char valid_loose_object_type[8] = {
742 0, /* OBJ_EXT */
743 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
744 0, /* "delta" and others are invalid in a loose object */
745 };
746 enum object_type type;
747
748 /* Get the data stream */
749 memset(stream, 0, sizeof(*stream));
750 stream->next_in = map;
751 stream->avail_in = mapsize;
752 stream->next_out = buffer;
753 stream->avail_out = bufsiz;
754
755 if (legacy_loose_object(map)) {
756 inflateInit(stream);
757 return inflate(stream, 0);
758 }
759
760 used = unpack_object_header_gently(map, mapsize, &type, &size);
761 if (!used || !valid_loose_object_type[type])
762 return -1;
763 map += used;
764 mapsize -= used;
765
766 /* Set up the stream for the rest.. */
767 stream->next_in = map;
768 stream->avail_in = mapsize;
769 inflateInit(stream);
770
771 /* And generate the fake traditional header */
772 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
773 type_names[type], size);
774 return 0;
775 }
776
777 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
778 {
779 int bytes = strlen(buffer) + 1;
780 unsigned char *buf = xmalloc(1+size);
781 unsigned long n;
782
783 n = stream->total_out - bytes;
784 if (n > size)
785 n = size;
786 memcpy(buf, (char *) buffer + bytes, n);
787 bytes = n;
788 if (bytes < size) {
789 stream->next_out = buf + bytes;
790 stream->avail_out = size - bytes;
791 while (inflate(stream, Z_FINISH) == Z_OK)
792 /* nothing */;
793 }
794 buf[size] = 0;
795 inflateEnd(stream);
796 return buf;
797 }
798
799 /*
800 * We used to just use "sscanf()", but that's actually way
801 * too permissive for what we want to check. So do an anal
802 * object header parse by hand.
803 */
804 static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
805 {
806 int i;
807 unsigned long size;
808
809 /*
810 * The type can be at most ten bytes (including the
811 * terminating '\0' that we add), and is followed by
812 * a space.
813 */
814 i = 10;
815 for (;;) {
816 char c = *hdr++;
817 if (c == ' ')
818 break;
819 if (!--i)
820 return -1;
821 *type++ = c;
822 }
823 *type = 0;
824
825 /*
826 * The length must follow immediately, and be in canonical
827 * decimal format (ie "010" is not valid).
828 */
829 size = *hdr++ - '0';
830 if (size > 9)
831 return -1;
832 if (size) {
833 for (;;) {
834 unsigned long c = *hdr - '0';
835 if (c > 9)
836 break;
837 hdr++;
838 size = size * 10 + c;
839 }
840 }
841 *sizep = size;
842
843 /*
844 * The length must be followed by a zero byte
845 */
846 return *hdr ? -1 : 0;
847 }
848
849 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
850 {
851 int ret;
852 z_stream stream;
853 char hdr[8192];
854
855 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
856 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
857 return NULL;
858
859 return unpack_sha1_rest(&stream, hdr, *size);
860 }
861
862 /* forward declaration for a mutually recursive function */
863 static int packed_object_info(struct pack_entry *entry,
864 char *type, unsigned long *sizep);
865
866 static int packed_delta_info(unsigned char *base_sha1,
867 unsigned long delta_size,
868 unsigned long left,
869 char *type,
870 unsigned long *sizep,
871 struct packed_git *p)
872 {
873 struct pack_entry base_ent;
874
875 if (left < 20)
876 die("truncated pack file");
877
878 /* The base entry _must_ be in the same pack */
879 if (!find_pack_entry_one(base_sha1, &base_ent, p))
880 die("failed to find delta-pack base object %s",
881 sha1_to_hex(base_sha1));
882
883 /* We choose to only get the type of the base object and
884 * ignore potentially corrupt pack file that expects the delta
885 * based on a base with a wrong size. This saves tons of
886 * inflate() calls.
887 */
888
889 if (packed_object_info(&base_ent, type, NULL))
890 die("cannot get info for delta-pack base");
891
892 if (sizep) {
893 const unsigned char *data;
894 unsigned char delta_head[64];
895 unsigned long result_size;
896 z_stream stream;
897 int st;
898
899 memset(&stream, 0, sizeof(stream));
900
901 data = stream.next_in = base_sha1 + 20;
902 stream.avail_in = left - 20;
903 stream.next_out = delta_head;
904 stream.avail_out = sizeof(delta_head);
905
906 inflateInit(&stream);
907 st = inflate(&stream, Z_FINISH);
908 inflateEnd(&stream);
909 if ((st != Z_STREAM_END) &&
910 stream.total_out != sizeof(delta_head))
911 die("delta data unpack-initial failed");
912
913 /* Examine the initial part of the delta to figure out
914 * the result size.
915 */
916 data = delta_head;
917
918 /* ignore base size */
919 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
920
921 /* Read the result size */
922 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
923 *sizep = result_size;
924 }
925 return 0;
926 }
927
928 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
929 enum object_type *type, unsigned long *sizep)
930 {
931 unsigned long used;
932
933 if (p->pack_size <= offset)
934 die("object offset outside of pack file");
935
936 used = unpack_object_header_gently((unsigned char *)p->pack_base +
937 offset,
938 p->pack_size - offset, type, sizep);
939 if (!used)
940 die("object offset outside of pack file");
941
942 return offset + used;
943 }
944
945 int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
946 unsigned char *base, unsigned long *sizep,
947 enum object_type *kindp)
948 {
949 unsigned long ptr;
950 int status = -1;
951
952 use_packed_git(p);
953 ptr = offset;
954 ptr = unpack_object_header(p, ptr, kindp, sizep);
955 if (*kindp != OBJ_DELTA)
956 goto done;
957 hashcpy(base, (unsigned char *) p->pack_base + ptr);
958 status = 0;
959 done:
960 unuse_packed_git(p);
961 return status;
962 }
963
964 void packed_object_info_detail(struct pack_entry *e,
965 char *type,
966 unsigned long *size,
967 unsigned long *store_size,
968 unsigned int *delta_chain_length,
969 unsigned char *base_sha1)
970 {
971 struct packed_git *p = e->p;
972 unsigned long offset;
973 unsigned char *pack;
974 enum object_type kind;
975
976 offset = unpack_object_header(p, e->offset, &kind, size);
977 pack = (unsigned char *) p->pack_base + offset;
978 if (kind != OBJ_DELTA)
979 *delta_chain_length = 0;
980 else {
981 unsigned int chain_length = 0;
982 if (p->pack_size <= offset + 20)
983 die("pack file %s records an incomplete delta base",
984 p->pack_name);
985 hashcpy(base_sha1, pack);
986 do {
987 struct pack_entry base_ent;
988 unsigned long junk;
989
990 find_pack_entry_one(pack, &base_ent, p);
991 offset = unpack_object_header(p, base_ent.offset,
992 &kind, &junk);
993 pack = (unsigned char *) p->pack_base + offset;
994 chain_length++;
995 } while (kind == OBJ_DELTA);
996 *delta_chain_length = chain_length;
997 }
998 switch (kind) {
999 case OBJ_COMMIT:
1000 case OBJ_TREE:
1001 case OBJ_BLOB:
1002 case OBJ_TAG:
1003 strcpy(type, type_names[kind]);
1004 break;
1005 default:
1006 die("corrupted pack file %s containing object of kind %d",
1007 p->pack_name, kind);
1008 }
1009 *store_size = 0; /* notyet */
1010 }
1011
1012 static int packed_object_info(struct pack_entry *entry,
1013 char *type, unsigned long *sizep)
1014 {
1015 struct packed_git *p = entry->p;
1016 unsigned long offset, size, left;
1017 unsigned char *pack;
1018 enum object_type kind;
1019 int retval;
1020
1021 if (use_packed_git(p))
1022 die("cannot map packed file");
1023
1024 offset = unpack_object_header(p, entry->offset, &kind, &size);
1025 pack = (unsigned char *) p->pack_base + offset;
1026 left = p->pack_size - offset;
1027
1028 switch (kind) {
1029 case OBJ_DELTA:
1030 retval = packed_delta_info(pack, size, left, type, sizep, p);
1031 unuse_packed_git(p);
1032 return retval;
1033 case OBJ_COMMIT:
1034 case OBJ_TREE:
1035 case OBJ_BLOB:
1036 case OBJ_TAG:
1037 strcpy(type, type_names[kind]);
1038 break;
1039 default:
1040 die("corrupted pack file %s containing object of kind %d",
1041 p->pack_name, kind);
1042 }
1043 if (sizep)
1044 *sizep = size;
1045 unuse_packed_git(p);
1046 return 0;
1047 }
1048
1049 static void *unpack_compressed_entry(struct packed_git *p,
1050 unsigned long offset,
1051 unsigned long size)
1052 {
1053 int st;
1054 z_stream stream;
1055 unsigned char *buffer;
1056
1057 buffer = xmalloc(size + 1);
1058 buffer[size] = 0;
1059 memset(&stream, 0, sizeof(stream));
1060 stream.next_in = (unsigned char*)p->pack_base + offset;
1061 stream.avail_in = p->pack_size - offset;
1062 stream.next_out = buffer;
1063 stream.avail_out = size;
1064
1065 inflateInit(&stream);
1066 st = inflate(&stream, Z_FINISH);
1067 inflateEnd(&stream);
1068 if ((st != Z_STREAM_END) || stream.total_out != size) {
1069 free(buffer);
1070 return NULL;
1071 }
1072
1073 return buffer;
1074 }
1075
1076 static void *unpack_delta_entry(struct packed_git *p,
1077 unsigned long offset,
1078 unsigned long delta_size,
1079 char *type,
1080 unsigned long *sizep)
1081 {
1082 struct pack_entry base_ent;
1083 void *delta_data, *result, *base;
1084 unsigned long result_size, base_size;
1085 unsigned char* base_sha1;
1086
1087 if ((offset + 20) >= p->pack_size)
1088 die("truncated pack file");
1089
1090 /* The base entry _must_ be in the same pack */
1091 base_sha1 = (unsigned char*)p->pack_base + offset;
1092 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1093 die("failed to find delta-pack base object %s",
1094 sha1_to_hex(base_sha1));
1095 base = unpack_entry_gently(&base_ent, type, &base_size);
1096 if (!base)
1097 die("failed to read delta-pack base object %s",
1098 sha1_to_hex(base_sha1));
1099
1100 delta_data = unpack_compressed_entry(p, offset + 20, delta_size);
1101 result = patch_delta(base, base_size,
1102 delta_data, delta_size,
1103 &result_size);
1104 if (!result)
1105 die("failed to apply delta");
1106 free(delta_data);
1107 free(base);
1108 *sizep = result_size;
1109 return result;
1110 }
1111
1112 static void *unpack_entry(struct pack_entry *entry,
1113 char *type, unsigned long *sizep)
1114 {
1115 struct packed_git *p = entry->p;
1116 void *retval;
1117
1118 if (use_packed_git(p))
1119 die("cannot map packed file");
1120 retval = unpack_entry_gently(entry, type, sizep);
1121 unuse_packed_git(p);
1122 if (!retval)
1123 die("corrupted pack file %s", p->pack_name);
1124 return retval;
1125 }
1126
1127 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1128 void *unpack_entry_gently(struct pack_entry *entry,
1129 char *type, unsigned long *sizep)
1130 {
1131 struct packed_git *p = entry->p;
1132 unsigned long offset, size;
1133 enum object_type kind;
1134
1135 offset = unpack_object_header(p, entry->offset, &kind, &size);
1136 switch (kind) {
1137 case OBJ_DELTA:
1138 return unpack_delta_entry(p, offset, size, type, sizep);
1139 case OBJ_COMMIT:
1140 case OBJ_TREE:
1141 case OBJ_BLOB:
1142 case OBJ_TAG:
1143 strcpy(type, type_names[kind]);
1144 *sizep = size;
1145 return unpack_compressed_entry(p, offset, size);
1146 default:
1147 return NULL;
1148 }
1149 }
1150
1151 int num_packed_objects(const struct packed_git *p)
1152 {
1153 /* See check_packed_git_idx() */
1154 return (p->index_size - 20 - 20 - 4*256) / 24;
1155 }
1156
1157 int nth_packed_object_sha1(const struct packed_git *p, int n,
1158 unsigned char* sha1)
1159 {
1160 void *index = p->index_base + 256;
1161 if (n < 0 || num_packed_objects(p) <= n)
1162 return -1;
1163 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1164 return 0;
1165 }
1166
1167 int find_pack_entry_one(const unsigned char *sha1,
1168 struct pack_entry *e, struct packed_git *p)
1169 {
1170 unsigned int *level1_ofs = p->index_base;
1171 int hi = ntohl(level1_ofs[*sha1]);
1172 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1173 void *index = p->index_base + 256;
1174
1175 do {
1176 int mi = (lo + hi) / 2;
1177 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1178 if (!cmp) {
1179 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1180 hashcpy(e->sha1, sha1);
1181 e->p = p;
1182 return 1;
1183 }
1184 if (cmp > 0)
1185 hi = mi;
1186 else
1187 lo = mi+1;
1188 } while (lo < hi);
1189 return 0;
1190 }
1191
1192 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1193 {
1194 struct packed_git *p;
1195 prepare_packed_git();
1196
1197 for (p = packed_git; p; p = p->next) {
1198 if (ignore_packed) {
1199 const char **ig;
1200 for (ig = ignore_packed; *ig; ig++)
1201 if (!strcmp(p->pack_name, *ig))
1202 break;
1203 if (*ig)
1204 continue;
1205 }
1206 if (find_pack_entry_one(sha1, e, p))
1207 return 1;
1208 }
1209 return 0;
1210 }
1211
1212 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1213 struct packed_git *packs)
1214 {
1215 struct packed_git *p;
1216 struct pack_entry e;
1217
1218 for (p = packs; p; p = p->next) {
1219 if (find_pack_entry_one(sha1, &e, p))
1220 return p;
1221 }
1222 return NULL;
1223
1224 }
1225
1226 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1227 {
1228 int status;
1229 unsigned long mapsize, size;
1230 void *map;
1231 z_stream stream;
1232 char hdr[128];
1233
1234 map = map_sha1_file(sha1, &mapsize);
1235 if (!map) {
1236 struct pack_entry e;
1237
1238 if (find_pack_entry(sha1, &e, NULL))
1239 return packed_object_info(&e, type, sizep);
1240 reprepare_packed_git();
1241 if (find_pack_entry(sha1, &e, NULL))
1242 return packed_object_info(&e, type, sizep);
1243 return error("unable to find %s", sha1_to_hex(sha1));
1244 }
1245 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1246 status = error("unable to unpack %s header",
1247 sha1_to_hex(sha1));
1248 if (parse_sha1_header(hdr, type, &size) < 0)
1249 status = error("unable to parse %s header", sha1_to_hex(sha1));
1250 else {
1251 status = 0;
1252 if (sizep)
1253 *sizep = size;
1254 }
1255 inflateEnd(&stream);
1256 munmap(map, mapsize);
1257 return status;
1258 }
1259
1260 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1261 {
1262 struct pack_entry e;
1263
1264 if (!find_pack_entry(sha1, &e, NULL)) {
1265 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1266 return NULL;
1267 }
1268 return unpack_entry(&e, type, size);
1269 }
1270
1271 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1272 {
1273 unsigned long mapsize;
1274 void *map, *buf;
1275 struct pack_entry e;
1276
1277 if (find_pack_entry(sha1, &e, NULL))
1278 return read_packed_sha1(sha1, type, size);
1279 map = map_sha1_file(sha1, &mapsize);
1280 if (map) {
1281 buf = unpack_sha1_file(map, mapsize, type, size);
1282 munmap(map, mapsize);
1283 return buf;
1284 }
1285 reprepare_packed_git();
1286 if (find_pack_entry(sha1, &e, NULL))
1287 return read_packed_sha1(sha1, type, size);
1288 return NULL;
1289 }
1290
1291 void *read_object_with_reference(const unsigned char *sha1,
1292 const char *required_type,
1293 unsigned long *size,
1294 unsigned char *actual_sha1_return)
1295 {
1296 char type[20];
1297 void *buffer;
1298 unsigned long isize;
1299 unsigned char actual_sha1[20];
1300
1301 hashcpy(actual_sha1, sha1);
1302 while (1) {
1303 int ref_length = -1;
1304 const char *ref_type = NULL;
1305
1306 buffer = read_sha1_file(actual_sha1, type, &isize);
1307 if (!buffer)
1308 return NULL;
1309 if (!strcmp(type, required_type)) {
1310 *size = isize;
1311 if (actual_sha1_return)
1312 hashcpy(actual_sha1_return, actual_sha1);
1313 return buffer;
1314 }
1315 /* Handle references */
1316 else if (!strcmp(type, commit_type))
1317 ref_type = "tree ";
1318 else if (!strcmp(type, tag_type))
1319 ref_type = "object ";
1320 else {
1321 free(buffer);
1322 return NULL;
1323 }
1324 ref_length = strlen(ref_type);
1325
1326 if (memcmp(buffer, ref_type, ref_length) ||
1327 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1328 free(buffer);
1329 return NULL;
1330 }
1331 free(buffer);
1332 /* Now we have the ID of the referred-to object in
1333 * actual_sha1. Check again. */
1334 }
1335 }
1336
1337 char *write_sha1_file_prepare(void *buf,
1338 unsigned long len,
1339 const char *type,
1340 unsigned char *sha1,
1341 unsigned char *hdr,
1342 int *hdrlen)
1343 {
1344 SHA_CTX c;
1345
1346 /* Generate the header */
1347 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1348
1349 /* Sha1.. */
1350 SHA1_Init(&c);
1351 SHA1_Update(&c, hdr, *hdrlen);
1352 SHA1_Update(&c, buf, len);
1353 SHA1_Final(sha1, &c);
1354
1355 return sha1_file_name(sha1);
1356 }
1357
1358 /*
1359 * Link the tempfile to the final place, possibly creating the
1360 * last directory level as you do so.
1361 *
1362 * Returns the errno on failure, 0 on success.
1363 */
1364 static int link_temp_to_file(const char *tmpfile, const char *filename)
1365 {
1366 int ret;
1367 char *dir;
1368
1369 if (!link(tmpfile, filename))
1370 return 0;
1371
1372 /*
1373 * Try to mkdir the last path component if that failed.
1374 *
1375 * Re-try the "link()" regardless of whether the mkdir
1376 * succeeds, since a race might mean that somebody
1377 * else succeeded.
1378 */
1379 ret = errno;
1380 dir = strrchr(filename, '/');
1381 if (dir) {
1382 *dir = 0;
1383 mkdir(filename, 0777);
1384 if (adjust_shared_perm(filename))
1385 return -2;
1386 *dir = '/';
1387 if (!link(tmpfile, filename))
1388 return 0;
1389 ret = errno;
1390 }
1391 return ret;
1392 }
1393
1394 /*
1395 * Move the just written object into its final resting place
1396 */
1397 int move_temp_to_file(const char *tmpfile, const char *filename)
1398 {
1399 int ret = link_temp_to_file(tmpfile, filename);
1400
1401 /*
1402 * Coda hack - coda doesn't like cross-directory links,
1403 * so we fall back to a rename, which will mean that it
1404 * won't be able to check collisions, but that's not a
1405 * big deal.
1406 *
1407 * The same holds for FAT formatted media.
1408 *
1409 * When this succeeds, we just return 0. We have nothing
1410 * left to unlink.
1411 */
1412 if (ret && ret != EEXIST) {
1413 if (!rename(tmpfile, filename))
1414 return 0;
1415 ret = errno;
1416 }
1417 unlink(tmpfile);
1418 if (ret) {
1419 if (ret != EEXIST) {
1420 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1421 return -1;
1422 }
1423 /* FIXME!!! Collision check here ? */
1424 }
1425
1426 return 0;
1427 }
1428
1429 static int write_buffer(int fd, const void *buf, size_t len)
1430 {
1431 while (len) {
1432 ssize_t size;
1433
1434 size = write(fd, buf, len);
1435 if (!size)
1436 return error("file write: disk full");
1437 if (size < 0) {
1438 if (errno == EINTR || errno == EAGAIN)
1439 continue;
1440 return error("file write error (%s)", strerror(errno));
1441 }
1442 len -= size;
1443 buf = (char *) buf + size;
1444 }
1445 return 0;
1446 }
1447
1448 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1449 {
1450 int hdr_len;
1451 unsigned char c;
1452
1453 c = (type << 4) | (len & 15);
1454 len >>= 4;
1455 hdr_len = 1;
1456 while (len) {
1457 *hdr++ = c | 0x80;
1458 hdr_len++;
1459 c = (len & 0x7f);
1460 len >>= 7;
1461 }
1462 *hdr = c;
1463 return hdr_len;
1464 }
1465
1466 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1467 {
1468 int obj_type, hdr;
1469
1470 if (use_legacy_headers) {
1471 while (deflate(stream, 0) == Z_OK)
1472 /* nothing */;
1473 return;
1474 }
1475 if (!strcmp(type, blob_type))
1476 obj_type = OBJ_BLOB;
1477 else if (!strcmp(type, tree_type))
1478 obj_type = OBJ_TREE;
1479 else if (!strcmp(type, commit_type))
1480 obj_type = OBJ_COMMIT;
1481 else if (!strcmp(type, tag_type))
1482 obj_type = OBJ_TAG;
1483 else
1484 die("trying to generate bogus object of type '%s'", type);
1485 hdr = write_binary_header(stream->next_out, obj_type, len);
1486 stream->total_out = hdr;
1487 stream->next_out += hdr;
1488 stream->avail_out -= hdr;
1489 }
1490
1491 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1492 {
1493 int size;
1494 unsigned char *compressed;
1495 z_stream stream;
1496 unsigned char sha1[20];
1497 char *filename;
1498 static char tmpfile[PATH_MAX];
1499 unsigned char hdr[50];
1500 int fd, hdrlen;
1501
1502 /* Normally if we have it in the pack then we do not bother writing
1503 * it out into .git/objects/??/?{38} file.
1504 */
1505 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1506 if (returnsha1)
1507 hashcpy(returnsha1, sha1);
1508 if (has_sha1_file(sha1))
1509 return 0;
1510 fd = open(filename, O_RDONLY);
1511 if (fd >= 0) {
1512 /*
1513 * FIXME!!! We might do collision checking here, but we'd
1514 * need to uncompress the old file and check it. Later.
1515 */
1516 close(fd);
1517 return 0;
1518 }
1519
1520 if (errno != ENOENT) {
1521 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1522 return -1;
1523 }
1524
1525 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1526
1527 fd = mkstemp(tmpfile);
1528 if (fd < 0) {
1529 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1530 return -1;
1531 }
1532
1533 /* Set it up */
1534 memset(&stream, 0, sizeof(stream));
1535 deflateInit(&stream, zlib_compression_level);
1536 size = 8 + deflateBound(&stream, len+hdrlen);
1537 compressed = xmalloc(size);
1538
1539 /* Compress it */
1540 stream.next_out = compressed;
1541 stream.avail_out = size;
1542
1543 /* First header.. */
1544 stream.next_in = hdr;
1545 stream.avail_in = hdrlen;
1546 setup_object_header(&stream, type, len);
1547
1548 /* Then the data itself.. */
1549 stream.next_in = buf;
1550 stream.avail_in = len;
1551 while (deflate(&stream, Z_FINISH) == Z_OK)
1552 /* nothing */;
1553 deflateEnd(&stream);
1554 size = stream.total_out;
1555
1556 if (write_buffer(fd, compressed, size) < 0)
1557 die("unable to write sha1 file");
1558 fchmod(fd, 0444);
1559 close(fd);
1560 free(compressed);
1561
1562 return move_temp_to_file(tmpfile, filename);
1563 }
1564
1565 /*
1566 * We need to unpack and recompress the object for writing
1567 * it out to a different file.
1568 */
1569 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1570 {
1571 size_t size;
1572 z_stream stream;
1573 unsigned char *unpacked;
1574 unsigned long len;
1575 char type[20];
1576 char hdr[50];
1577 int hdrlen;
1578 void *buf;
1579
1580 /* need to unpack and recompress it by itself */
1581 unpacked = read_packed_sha1(sha1, type, &len);
1582
1583 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1584
1585 /* Set it up */
1586 memset(&stream, 0, sizeof(stream));
1587 deflateInit(&stream, zlib_compression_level);
1588 size = deflateBound(&stream, len + hdrlen);
1589 buf = xmalloc(size);
1590
1591 /* Compress it */
1592 stream.next_out = buf;
1593 stream.avail_out = size;
1594
1595 /* First header.. */
1596 stream.next_in = (void *)hdr;
1597 stream.avail_in = hdrlen;
1598 while (deflate(&stream, 0) == Z_OK)
1599 /* nothing */;
1600
1601 /* Then the data itself.. */
1602 stream.next_in = unpacked;
1603 stream.avail_in = len;
1604 while (deflate(&stream, Z_FINISH) == Z_OK)
1605 /* nothing */;
1606 deflateEnd(&stream);
1607 free(unpacked);
1608
1609 *objsize = stream.total_out;
1610 return buf;
1611 }
1612
1613 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1614 {
1615 int retval;
1616 unsigned long objsize;
1617 void *buf = map_sha1_file(sha1, &objsize);
1618
1619 if (buf) {
1620 retval = write_buffer(fd, buf, objsize);
1621 munmap(buf, objsize);
1622 return retval;
1623 }
1624
1625 buf = repack_object(sha1, &objsize);
1626 retval = write_buffer(fd, buf, objsize);
1627 free(buf);
1628 return retval;
1629 }
1630
1631 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1632 size_t bufsize, size_t *bufposn)
1633 {
1634 char tmpfile[PATH_MAX];
1635 int local;
1636 z_stream stream;
1637 unsigned char real_sha1[20];
1638 unsigned char discard[4096];
1639 int ret;
1640 SHA_CTX c;
1641
1642 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1643
1644 local = mkstemp(tmpfile);
1645 if (local < 0)
1646 return error("Couldn't open %s for %s",
1647 tmpfile, sha1_to_hex(sha1));
1648
1649 memset(&stream, 0, sizeof(stream));
1650
1651 inflateInit(&stream);
1652
1653 SHA1_Init(&c);
1654
1655 do {
1656 ssize_t size;
1657 if (*bufposn) {
1658 stream.avail_in = *bufposn;
1659 stream.next_in = (unsigned char *) buffer;
1660 do {
1661 stream.next_out = discard;
1662 stream.avail_out = sizeof(discard);
1663 ret = inflate(&stream, Z_SYNC_FLUSH);
1664 SHA1_Update(&c, discard, sizeof(discard) -
1665 stream.avail_out);
1666 } while (stream.avail_in && ret == Z_OK);
1667 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1668 die("unable to write sha1 file");
1669 memmove(buffer, buffer + *bufposn - stream.avail_in,
1670 stream.avail_in);
1671 *bufposn = stream.avail_in;
1672 if (ret != Z_OK)
1673 break;
1674 }
1675 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1676 if (size <= 0) {
1677 close(local);
1678 unlink(tmpfile);
1679 if (!size)
1680 return error("Connection closed?");
1681 perror("Reading from connection");
1682 return -1;
1683 }
1684 *bufposn += size;
1685 } while (1);
1686 inflateEnd(&stream);
1687
1688 close(local);
1689 SHA1_Final(real_sha1, &c);
1690 if (ret != Z_STREAM_END) {
1691 unlink(tmpfile);
1692 return error("File %s corrupted", sha1_to_hex(sha1));
1693 }
1694 if (hashcmp(sha1, real_sha1)) {
1695 unlink(tmpfile);
1696 return error("File %s has bad hash", sha1_to_hex(sha1));
1697 }
1698
1699 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1700 }
1701
1702 int has_pack_index(const unsigned char *sha1)
1703 {
1704 struct stat st;
1705 if (stat(sha1_pack_index_name(sha1), &st))
1706 return 0;
1707 return 1;
1708 }
1709
1710 int has_pack_file(const unsigned char *sha1)
1711 {
1712 struct stat st;
1713 if (stat(sha1_pack_name(sha1), &st))
1714 return 0;
1715 return 1;
1716 }
1717
1718 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1719 {
1720 struct pack_entry e;
1721 return find_pack_entry(sha1, &e, ignore_packed);
1722 }
1723
1724 int has_sha1_file(const unsigned char *sha1)
1725 {
1726 struct stat st;
1727 struct pack_entry e;
1728
1729 if (find_pack_entry(sha1, &e, NULL))
1730 return 1;
1731 return find_sha1_file(sha1, &st) ? 1 : 0;
1732 }
1733
1734 /*
1735 * reads from fd as long as possible into a supplied buffer of size bytes.
1736 * If necessary the buffer's size is increased using realloc()
1737 *
1738 * returns 0 if anything went fine and -1 otherwise
1739 *
1740 * NOTE: both buf and size may change, but even when -1 is returned
1741 * you still have to free() it yourself.
1742 */
1743 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1744 {
1745 char* buf = *return_buf;
1746 unsigned long size = *return_size;
1747 int iret;
1748 unsigned long off = 0;
1749
1750 do {
1751 iret = xread(fd, buf + off, size - off);
1752 if (iret > 0) {
1753 off += iret;
1754 if (off == size) {
1755 size *= 2;
1756 buf = xrealloc(buf, size);
1757 }
1758 }
1759 } while (iret > 0);
1760
1761 *return_buf = buf;
1762 *return_size = off;
1763
1764 if (iret < 0)
1765 return -1;
1766 return 0;
1767 }
1768
1769 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1770 {
1771 unsigned long size = 4096;
1772 char *buf = xmalloc(size);
1773 int ret;
1774 unsigned char hdr[50];
1775 int hdrlen;
1776
1777 if (read_pipe(fd, &buf, &size)) {
1778 free(buf);
1779 return -1;
1780 }
1781
1782 if (!type)
1783 type = blob_type;
1784 if (write_object)
1785 ret = write_sha1_file(buf, size, type, sha1);
1786 else {
1787 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1788 ret = 0;
1789 }
1790 free(buf);
1791 return ret;
1792 }
1793
1794 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1795 {
1796 unsigned long size = st->st_size;
1797 void *buf;
1798 int ret;
1799 unsigned char hdr[50];
1800 int hdrlen;
1801
1802 buf = "";
1803 if (size)
1804 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1805 close(fd);
1806 if (buf == MAP_FAILED)
1807 return -1;
1808
1809 if (!type)
1810 type = blob_type;
1811 if (write_object)
1812 ret = write_sha1_file(buf, size, type, sha1);
1813 else {
1814 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1815 ret = 0;
1816 }
1817 if (size)
1818 munmap(buf, size);
1819 return ret;
1820 }
1821
1822 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1823 {
1824 int fd;
1825 char *target;
1826
1827 switch (st->st_mode & S_IFMT) {
1828 case S_IFREG:
1829 fd = open(path, O_RDONLY);
1830 if (fd < 0)
1831 return error("open(\"%s\"): %s", path,
1832 strerror(errno));
1833 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1834 return error("%s: failed to insert into database",
1835 path);
1836 break;
1837 case S_IFLNK:
1838 target = xmalloc(st->st_size+1);
1839 if (readlink(path, target, st->st_size+1) != st->st_size) {
1840 char *errstr = strerror(errno);
1841 free(target);
1842 return error("readlink(\"%s\"): %s", path,
1843 errstr);
1844 }
1845 if (!write_object) {
1846 unsigned char hdr[50];
1847 int hdrlen;
1848 write_sha1_file_prepare(target, st->st_size, blob_type,
1849 sha1, hdr, &hdrlen);
1850 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1851 return error("%s: failed to insert into database",
1852 path);
1853 free(target);
1854 break;
1855 default:
1856 return error("%s: unsupported file type", path);
1857 }
1858 return 0;
1859 }