5f34c69d3a80167a8337b9c6a5382e78f857428f
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
25const unsigned char null_sha1[20];
26
27static unsigned int sha1_file_open_flag = O_NOATIME;
28
29static 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
40int 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
53int 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
86char * 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
104static 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 "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 */
126char *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
144char *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
169char *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
194struct alternate_object_database *alt_odb_list;
195static struct alternate_object_database **alt_odb_tail;
196
197static 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 */
214static 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
282static 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
319static 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
344void 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
359static 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)
377static int pack_used_ctr;
378static unsigned long pack_mapped;
379struct packed_git *packed_git;
380
381static 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
430static 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
447void unuse_packed_git(struct packed_git *p)
448{
449 p->pack_use_cnt--;
450}
451
452int 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
512struct 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 memcpy(p->sha1, sha1, 20);
544 return p;
545}
546
547struct 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
553struct 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 memcpy(p->sha1, sha1, 20);
575 return p;
576}
577
578void install_packed_git(struct packed_git *pack)
579{
580 pack->next = packed_git;
581 packed_git = pack;
582}
583
584static 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
625static int prepare_packed_git_run_once = 0;
626void 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
642static void reprepare_packed_git(void)
643{
644 prepare_packed_git_run_once = 0;
645 prepare_packed_git();
646}
647
648int 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
661void *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
698int 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
714static 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;
725
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;
732
733 if (legacy_loose_object(map)) {
734 inflateInit(stream);
735 return inflate(stream, 0);
736 }
737
738 c = *map++;
739 mapsize--;
740 type = typename[(c >> 4) & 7];
741 if (!type)
742 return -1;
743
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 }
754
755 /* Set up the stream for the rest.. */
756 stream->next_in = map;
757 stream->avail_in = mapsize;
758 inflateInit(stream);
759
760 /* And generate the fake traditional header */
761 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", type, size);
762 return 0;
763}
764
765static 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;
770
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}
786
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 */
792static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
793{
794 int i;
795 unsigned long size;
796
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;
812
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;
830
831 /*
832 * The length must be followed by a zero byte
833 */
834 return *hdr ? -1 : 0;
835}
836
837void * 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];
842
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;
846
847 return unpack_sha1_rest(&stream, hdr, *size);
848}
849
850/* forward declaration for a mutually recursive function */
851static int packed_object_info(struct pack_entry *entry,
852 char *type, unsigned long *sizep);
853
854static 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;
862
863 if (left < 20)
864 die("truncated pack file");
865
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));
870
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 */
876
877 if (packed_object_info(&base_ent, type, NULL))
878 die("cannot get info for delta-pack base");
879
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;
886
887 memset(&stream, 0, sizeof(stream));
888
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);
893
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");
900
901 /* Examine the initial part of the delta to figure out
902 * the result size.
903 */
904 data = delta_head;
905
906 /* ignore base size */
907 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
908
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}
915
916static 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;
922
923 if (offset >= p->pack_size)
924 die("object offset outside of pack file");
925
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}
943
944int 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;
950
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 memcpy(base, (unsigned char *) p->pack_base + ptr, 20);
957 status = 0;
958 done:
959 unuse_packed_git(p);
960 return status;
961}
962
963void 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;
974
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 memcpy(base_sha1, pack, 20);
985 do {
986 struct pack_entry base_ent;
987 unsigned long junk;
988
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}
1016
1017static 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;
1025
1026 if (use_packed_git(p))
1027 die("cannot map packed file");
1028
1029 offset = unpack_object_header(p, entry->offset, &kind, &size);
1030 pack = (unsigned char *) p->pack_base + offset;
1031 left = p->pack_size - offset;
1032
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}
1059
1060/* forward declaration for a mutually recursive function */
1061static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
1062
1063static void *unpack_delta_entry(unsigned char *base_sha1,
1064 unsigned long delta_size,
1065 unsigned long left,
1066 char *type,
1067 unsigned long *sizep,
1068 struct packed_git *p)
1069{
1070 struct pack_entry base_ent;
1071 void *data, *delta_data, *result, *base;
1072 unsigned long data_size, result_size, base_size;
1073 z_stream stream;
1074 int st;
1075
1076 if (left < 20)
1077 die("truncated pack file");
1078
1079 /* The base entry _must_ be in the same pack */
1080 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1081 die("failed to find delta-pack base object %s",
1082 sha1_to_hex(base_sha1));
1083 base = unpack_entry_gently(&base_ent, type, &base_size);
1084 if (!base)
1085 die("failed to read delta-pack base object %s",
1086 sha1_to_hex(base_sha1));
1087
1088 data = base_sha1 + 20;
1089 data_size = left - 20;
1090 delta_data = xmalloc(delta_size);
1091
1092 memset(&stream, 0, sizeof(stream));
1093
1094 stream.next_in = data;
1095 stream.avail_in = data_size;
1096 stream.next_out = delta_data;
1097 stream.avail_out = delta_size;
1098
1099 inflateInit(&stream);
1100 st = inflate(&stream, Z_FINISH);
1101 inflateEnd(&stream);
1102 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
1103 die("delta data unpack failed");
1104
1105 result = patch_delta(base, base_size,
1106 delta_data, delta_size,
1107 &result_size);
1108 if (!result)
1109 die("failed to apply delta");
1110 free(delta_data);
1111 free(base);
1112 *sizep = result_size;
1113 return result;
1114}
1115
1116static void *unpack_non_delta_entry(unsigned char *data,
1117 unsigned long size,
1118 unsigned long left)
1119{
1120 int st;
1121 z_stream stream;
1122 unsigned char *buffer;
1123
1124 buffer = xmalloc(size + 1);
1125 buffer[size] = 0;
1126 memset(&stream, 0, sizeof(stream));
1127 stream.next_in = data;
1128 stream.avail_in = left;
1129 stream.next_out = buffer;
1130 stream.avail_out = size;
1131
1132 inflateInit(&stream);
1133 st = inflate(&stream, Z_FINISH);
1134 inflateEnd(&stream);
1135 if ((st != Z_STREAM_END) || stream.total_out != size) {
1136 free(buffer);
1137 return NULL;
1138 }
1139
1140 return buffer;
1141}
1142
1143static void *unpack_entry(struct pack_entry *entry,
1144 char *type, unsigned long *sizep)
1145{
1146 struct packed_git *p = entry->p;
1147 void *retval;
1148
1149 if (use_packed_git(p))
1150 die("cannot map packed file");
1151 retval = unpack_entry_gently(entry, type, sizep);
1152 unuse_packed_git(p);
1153 if (!retval)
1154 die("corrupted pack file %s", p->pack_name);
1155 return retval;
1156}
1157
1158/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1159void *unpack_entry_gently(struct pack_entry *entry,
1160 char *type, unsigned long *sizep)
1161{
1162 struct packed_git *p = entry->p;
1163 unsigned long offset, size, left;
1164 unsigned char *pack;
1165 enum object_type kind;
1166 void *retval;
1167
1168 offset = unpack_object_header(p, entry->offset, &kind, &size);
1169 pack = (unsigned char *) p->pack_base + offset;
1170 left = p->pack_size - offset;
1171 switch (kind) {
1172 case OBJ_DELTA:
1173 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
1174 return retval;
1175 case OBJ_COMMIT:
1176 strcpy(type, commit_type);
1177 break;
1178 case OBJ_TREE:
1179 strcpy(type, tree_type);
1180 break;
1181 case OBJ_BLOB:
1182 strcpy(type, blob_type);
1183 break;
1184 case OBJ_TAG:
1185 strcpy(type, tag_type);
1186 break;
1187 default:
1188 return NULL;
1189 }
1190 *sizep = size;
1191 retval = unpack_non_delta_entry(pack, size, left);
1192 return retval;
1193}
1194
1195int num_packed_objects(const struct packed_git *p)
1196{
1197 /* See check_packed_git_idx() */
1198 return (p->index_size - 20 - 20 - 4*256) / 24;
1199}
1200
1201int nth_packed_object_sha1(const struct packed_git *p, int n,
1202 unsigned char* sha1)
1203{
1204 void *index = p->index_base + 256;
1205 if (n < 0 || num_packed_objects(p) <= n)
1206 return -1;
1207 memcpy(sha1, (char *) index + (24 * n) + 4, 20);
1208 return 0;
1209}
1210
1211int find_pack_entry_one(const unsigned char *sha1,
1212 struct pack_entry *e, struct packed_git *p)
1213{
1214 unsigned int *level1_ofs = p->index_base;
1215 int hi = ntohl(level1_ofs[*sha1]);
1216 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1217 void *index = p->index_base + 256;
1218
1219 do {
1220 int mi = (lo + hi) / 2;
1221 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1222 if (!cmp) {
1223 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1224 memcpy(e->sha1, sha1, 20);
1225 e->p = p;
1226 return 1;
1227 }
1228 if (cmp > 0)
1229 hi = mi;
1230 else
1231 lo = mi+1;
1232 } while (lo < hi);
1233 return 0;
1234}
1235
1236static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1237{
1238 struct packed_git *p;
1239 prepare_packed_git();
1240
1241 for (p = packed_git; p; p = p->next) {
1242 if (find_pack_entry_one(sha1, e, p))
1243 return 1;
1244 }
1245 return 0;
1246}
1247
1248struct packed_git *find_sha1_pack(const unsigned char *sha1,
1249 struct packed_git *packs)
1250{
1251 struct packed_git *p;
1252 struct pack_entry e;
1253
1254 for (p = packs; p; p = p->next) {
1255 if (find_pack_entry_one(sha1, &e, p))
1256 return p;
1257 }
1258 return NULL;
1259
1260}
1261
1262int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1263{
1264 int status;
1265 unsigned long mapsize, size;
1266 void *map;
1267 z_stream stream;
1268 char hdr[128];
1269
1270 map = map_sha1_file(sha1, &mapsize);
1271 if (!map) {
1272 struct pack_entry e;
1273
1274 if (find_pack_entry(sha1, &e))
1275 return packed_object_info(&e, type, sizep);
1276 reprepare_packed_git();
1277 if (find_pack_entry(sha1, &e))
1278 return packed_object_info(&e, type, sizep);
1279 return error("unable to find %s", sha1_to_hex(sha1));
1280 }
1281 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1282 status = error("unable to unpack %s header",
1283 sha1_to_hex(sha1));
1284 if (parse_sha1_header(hdr, type, &size) < 0)
1285 status = error("unable to parse %s header", sha1_to_hex(sha1));
1286 else {
1287 status = 0;
1288 if (sizep)
1289 *sizep = size;
1290 }
1291 inflateEnd(&stream);
1292 munmap(map, mapsize);
1293 return status;
1294}
1295
1296static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1297{
1298 struct pack_entry e;
1299
1300 if (!find_pack_entry(sha1, &e)) {
1301 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1302 return NULL;
1303 }
1304 return unpack_entry(&e, type, size);
1305}
1306
1307void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1308{
1309 unsigned long mapsize;
1310 void *map, *buf;
1311 struct pack_entry e;
1312
1313 if (find_pack_entry(sha1, &e))
1314 return read_packed_sha1(sha1, type, size);
1315 map = map_sha1_file(sha1, &mapsize);
1316 if (map) {
1317 buf = unpack_sha1_file(map, mapsize, type, size);
1318 munmap(map, mapsize);
1319 return buf;
1320 }
1321 reprepare_packed_git();
1322 if (find_pack_entry(sha1, &e))
1323 return read_packed_sha1(sha1, type, size);
1324 return NULL;
1325}
1326
1327void *read_object_with_reference(const unsigned char *sha1,
1328 const char *required_type,
1329 unsigned long *size,
1330 unsigned char *actual_sha1_return)
1331{
1332 char type[20];
1333 void *buffer;
1334 unsigned long isize;
1335 unsigned char actual_sha1[20];
1336
1337 memcpy(actual_sha1, sha1, 20);
1338 while (1) {
1339 int ref_length = -1;
1340 const char *ref_type = NULL;
1341
1342 buffer = read_sha1_file(actual_sha1, type, &isize);
1343 if (!buffer)
1344 return NULL;
1345 if (!strcmp(type, required_type)) {
1346 *size = isize;
1347 if (actual_sha1_return)
1348 memcpy(actual_sha1_return, actual_sha1, 20);
1349 return buffer;
1350 }
1351 /* Handle references */
1352 else if (!strcmp(type, commit_type))
1353 ref_type = "tree ";
1354 else if (!strcmp(type, tag_type))
1355 ref_type = "object ";
1356 else {
1357 free(buffer);
1358 return NULL;
1359 }
1360 ref_length = strlen(ref_type);
1361
1362 if (memcmp(buffer, ref_type, ref_length) ||
1363 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1364 free(buffer);
1365 return NULL;
1366 }
1367 free(buffer);
1368 /* Now we have the ID of the referred-to object in
1369 * actual_sha1. Check again. */
1370 }
1371}
1372
1373char *write_sha1_file_prepare(void *buf,
1374 unsigned long len,
1375 const char *type,
1376 unsigned char *sha1,
1377 unsigned char *hdr,
1378 int *hdrlen)
1379{
1380 SHA_CTX c;
1381
1382 /* Generate the header */
1383 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1384
1385 /* Sha1.. */
1386 SHA1_Init(&c);
1387 SHA1_Update(&c, hdr, *hdrlen);
1388 SHA1_Update(&c, buf, len);
1389 SHA1_Final(sha1, &c);
1390
1391 return sha1_file_name(sha1);
1392}
1393
1394/*
1395 * Link the tempfile to the final place, possibly creating the
1396 * last directory level as you do so.
1397 *
1398 * Returns the errno on failure, 0 on success.
1399 */
1400static int link_temp_to_file(const char *tmpfile, char *filename)
1401{
1402 int ret;
1403 char *dir;
1404
1405 if (!link(tmpfile, filename))
1406 return 0;
1407
1408 /*
1409 * Try to mkdir the last path component if that failed.
1410 *
1411 * Re-try the "link()" regardless of whether the mkdir
1412 * succeeds, since a race might mean that somebody
1413 * else succeeded.
1414 */
1415 ret = errno;
1416 dir = strrchr(filename, '/');
1417 if (dir) {
1418 *dir = 0;
1419 mkdir(filename, 0777);
1420 if (adjust_shared_perm(filename))
1421 return -2;
1422 *dir = '/';
1423 if (!link(tmpfile, filename))
1424 return 0;
1425 ret = errno;
1426 }
1427 return ret;
1428}
1429
1430/*
1431 * Move the just written object into its final resting place
1432 */
1433int move_temp_to_file(const char *tmpfile, char *filename)
1434{
1435 int ret = link_temp_to_file(tmpfile, filename);
1436
1437 /*
1438 * Coda hack - coda doesn't like cross-directory links,
1439 * so we fall back to a rename, which will mean that it
1440 * won't be able to check collisions, but that's not a
1441 * big deal.
1442 *
1443 * The same holds for FAT formatted media.
1444 *
1445 * When this succeeds, we just return 0. We have nothing
1446 * left to unlink.
1447 */
1448 if (ret && ret != EEXIST) {
1449 if (!rename(tmpfile, filename))
1450 return 0;
1451 ret = errno;
1452 }
1453 unlink(tmpfile);
1454 if (ret) {
1455 if (ret != EEXIST) {
1456 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1457 return -1;
1458 }
1459 /* FIXME!!! Collision check here ? */
1460 }
1461
1462 return 0;
1463}
1464
1465static int write_buffer(int fd, const void *buf, size_t len)
1466{
1467 while (len) {
1468 ssize_t size;
1469
1470 size = write(fd, buf, len);
1471 if (!size)
1472 return error("file write: disk full");
1473 if (size < 0) {
1474 if (errno == EINTR || errno == EAGAIN)
1475 continue;
1476 return error("file write error (%s)", strerror(errno));
1477 }
1478 len -= size;
1479 buf = (char *) buf + size;
1480 }
1481 return 0;
1482}
1483
1484static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1485{
1486 int hdr_len;
1487 unsigned char c;
1488
1489 c = (type << 4) | (len & 15);
1490 len >>= 4;
1491 hdr_len = 1;
1492 while (len) {
1493 *hdr++ = c | 0x80;
1494 hdr_len++;
1495 c = (len & 0x7f);
1496 len >>= 7;
1497 }
1498 *hdr = c;
1499 return hdr_len;
1500}
1501
1502static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1503{
1504 int obj_type, hdr;
1505
1506 if (use_legacy_headers) {
1507 while (deflate(stream, 0) == Z_OK)
1508 /* nothing */;
1509 return;
1510 }
1511 if (!strcmp(type, blob_type))
1512 obj_type = OBJ_BLOB;
1513 else if (!strcmp(type, tree_type))
1514 obj_type = OBJ_TREE;
1515 else if (!strcmp(type, commit_type))
1516 obj_type = OBJ_COMMIT;
1517 else if (!strcmp(type, tag_type))
1518 obj_type = OBJ_TAG;
1519 else
1520 die("trying to generate bogus object of type '%s'", type);
1521 hdr = write_binary_header(stream->next_out, obj_type, len);
1522 stream->total_out = hdr;
1523 stream->next_out += hdr;
1524 stream->avail_out -= hdr;
1525}
1526
1527int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1528{
1529 int size;
1530 unsigned char *compressed;
1531 z_stream stream;
1532 unsigned char sha1[20];
1533 char *filename;
1534 static char tmpfile[PATH_MAX];
1535 unsigned char hdr[50];
1536 int fd, hdrlen;
1537
1538 /* Normally if we have it in the pack then we do not bother writing
1539 * it out into .git/objects/??/?{38} file.
1540 */
1541 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1542 if (returnsha1)
1543 memcpy(returnsha1, sha1, 20);
1544 if (has_sha1_file(sha1))
1545 return 0;
1546 fd = open(filename, O_RDONLY);
1547 if (fd >= 0) {
1548 /*
1549 * FIXME!!! We might do collision checking here, but we'd
1550 * need to uncompress the old file and check it. Later.
1551 */
1552 close(fd);
1553 return 0;
1554 }
1555
1556 if (errno != ENOENT) {
1557 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1558 return -1;
1559 }
1560
1561 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1562
1563 fd = mkstemp(tmpfile);
1564 if (fd < 0) {
1565 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1566 return -1;
1567 }
1568
1569 /* Set it up */
1570 memset(&stream, 0, sizeof(stream));
1571 deflateInit(&stream, zlib_compression_level);
1572 size = 8 + deflateBound(&stream, len+hdrlen);
1573 compressed = xmalloc(size);
1574
1575 /* Compress it */
1576 stream.next_out = compressed;
1577 stream.avail_out = size;
1578
1579 /* First header.. */
1580 stream.next_in = hdr;
1581 stream.avail_in = hdrlen;
1582 setup_object_header(&stream, type, len);
1583
1584 /* Then the data itself.. */
1585 stream.next_in = buf;
1586 stream.avail_in = len;
1587 while (deflate(&stream, Z_FINISH) == Z_OK)
1588 /* nothing */;
1589 deflateEnd(&stream);
1590 size = stream.total_out;
1591
1592 if (write_buffer(fd, compressed, size) < 0)
1593 die("unable to write sha1 file");
1594 fchmod(fd, 0444);
1595 close(fd);
1596 free(compressed);
1597
1598 return move_temp_to_file(tmpfile, filename);
1599}
1600
1601/*
1602 * We need to unpack and recompress the object for writing
1603 * it out to a different file.
1604 */
1605static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1606{
1607 size_t size;
1608 z_stream stream;
1609 unsigned char *unpacked;
1610 unsigned long len;
1611 char type[20];
1612 char hdr[50];
1613 int hdrlen;
1614 void *buf;
1615
1616 /* need to unpack and recompress it by itself */
1617 unpacked = read_packed_sha1(sha1, type, &len);
1618
1619 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1620
1621 /* Set it up */
1622 memset(&stream, 0, sizeof(stream));
1623 deflateInit(&stream, zlib_compression_level);
1624 size = deflateBound(&stream, len + hdrlen);
1625 buf = xmalloc(size);
1626
1627 /* Compress it */
1628 stream.next_out = buf;
1629 stream.avail_out = size;
1630
1631 /* First header.. */
1632 stream.next_in = (void *)hdr;
1633 stream.avail_in = hdrlen;
1634 while (deflate(&stream, 0) == Z_OK)
1635 /* nothing */;
1636
1637 /* Then the data itself.. */
1638 stream.next_in = unpacked;
1639 stream.avail_in = len;
1640 while (deflate(&stream, Z_FINISH) == Z_OK)
1641 /* nothing */;
1642 deflateEnd(&stream);
1643 free(unpacked);
1644
1645 *objsize = stream.total_out;
1646 return buf;
1647}
1648
1649int write_sha1_to_fd(int fd, const unsigned char *sha1)
1650{
1651 int retval;
1652 unsigned long objsize;
1653 void *buf = map_sha1_file(sha1, &objsize);
1654
1655 if (buf) {
1656 retval = write_buffer(fd, buf, objsize);
1657 munmap(buf, objsize);
1658 return retval;
1659 }
1660
1661 buf = repack_object(sha1, &objsize);
1662 retval = write_buffer(fd, buf, objsize);
1663 free(buf);
1664 return retval;
1665}
1666
1667int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1668 size_t bufsize, size_t *bufposn)
1669{
1670 char tmpfile[PATH_MAX];
1671 int local;
1672 z_stream stream;
1673 unsigned char real_sha1[20];
1674 unsigned char discard[4096];
1675 int ret;
1676 SHA_CTX c;
1677
1678 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1679
1680 local = mkstemp(tmpfile);
1681 if (local < 0)
1682 return error("Couldn't open %s for %s",
1683 tmpfile, sha1_to_hex(sha1));
1684
1685 memset(&stream, 0, sizeof(stream));
1686
1687 inflateInit(&stream);
1688
1689 SHA1_Init(&c);
1690
1691 do {
1692 ssize_t size;
1693 if (*bufposn) {
1694 stream.avail_in = *bufposn;
1695 stream.next_in = (unsigned char *) buffer;
1696 do {
1697 stream.next_out = discard;
1698 stream.avail_out = sizeof(discard);
1699 ret = inflate(&stream, Z_SYNC_FLUSH);
1700 SHA1_Update(&c, discard, sizeof(discard) -
1701 stream.avail_out);
1702 } while (stream.avail_in && ret == Z_OK);
1703 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1704 die("unable to write sha1 file");
1705 memmove(buffer, buffer + *bufposn - stream.avail_in,
1706 stream.avail_in);
1707 *bufposn = stream.avail_in;
1708 if (ret != Z_OK)
1709 break;
1710 }
1711 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1712 if (size <= 0) {
1713 close(local);
1714 unlink(tmpfile);
1715 if (!size)
1716 return error("Connection closed?");
1717 perror("Reading from connection");
1718 return -1;
1719 }
1720 *bufposn += size;
1721 } while (1);
1722 inflateEnd(&stream);
1723
1724 close(local);
1725 SHA1_Final(real_sha1, &c);
1726 if (ret != Z_STREAM_END) {
1727 unlink(tmpfile);
1728 return error("File %s corrupted", sha1_to_hex(sha1));
1729 }
1730 if (hashcmp(sha1, real_sha1)) {
1731 unlink(tmpfile);
1732 return error("File %s has bad hash", sha1_to_hex(sha1));
1733 }
1734
1735 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1736}
1737
1738int has_pack_index(const unsigned char *sha1)
1739{
1740 struct stat st;
1741 if (stat(sha1_pack_index_name(sha1), &st))
1742 return 0;
1743 return 1;
1744}
1745
1746int has_pack_file(const unsigned char *sha1)
1747{
1748 struct stat st;
1749 if (stat(sha1_pack_name(sha1), &st))
1750 return 0;
1751 return 1;
1752}
1753
1754int has_sha1_pack(const unsigned char *sha1)
1755{
1756 struct pack_entry e;
1757 return find_pack_entry(sha1, &e);
1758}
1759
1760int has_sha1_file(const unsigned char *sha1)
1761{
1762 struct stat st;
1763 struct pack_entry e;
1764
1765 if (find_pack_entry(sha1, &e))
1766 return 1;
1767 return find_sha1_file(sha1, &st) ? 1 : 0;
1768}
1769
1770/*
1771 * reads from fd as long as possible into a supplied buffer of size bytes.
1772 * If necessary the buffer's size is increased using realloc()
1773 *
1774 * returns 0 if anything went fine and -1 otherwise
1775 *
1776 * NOTE: both buf and size may change, but even when -1 is returned
1777 * you still have to free() it yourself.
1778 */
1779int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1780{
1781 char* buf = *return_buf;
1782 unsigned long size = *return_size;
1783 int iret;
1784 unsigned long off = 0;
1785
1786 do {
1787 iret = xread(fd, buf + off, size - off);
1788 if (iret > 0) {
1789 off += iret;
1790 if (off == size) {
1791 size *= 2;
1792 buf = realloc(buf, size);
1793 }
1794 }
1795 } while (iret > 0);
1796
1797 *return_buf = buf;
1798 *return_size = off;
1799
1800 if (iret < 0)
1801 return -1;
1802 return 0;
1803}
1804
1805int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1806{
1807 unsigned long size = 4096;
1808 char *buf = malloc(size);
1809 int ret;
1810 unsigned char hdr[50];
1811 int hdrlen;
1812
1813 if (read_pipe(fd, &buf, &size)) {
1814 free(buf);
1815 return -1;
1816 }
1817
1818 if (!type)
1819 type = blob_type;
1820 if (write_object)
1821 ret = write_sha1_file(buf, size, type, sha1);
1822 else {
1823 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1824 ret = 0;
1825 }
1826 free(buf);
1827 return ret;
1828}
1829
1830int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1831{
1832 unsigned long size = st->st_size;
1833 void *buf;
1834 int ret;
1835 unsigned char hdr[50];
1836 int hdrlen;
1837
1838 buf = "";
1839 if (size)
1840 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1841 close(fd);
1842 if (buf == MAP_FAILED)
1843 return -1;
1844
1845 if (!type)
1846 type = blob_type;
1847 if (write_object)
1848 ret = write_sha1_file(buf, size, type, sha1);
1849 else {
1850 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1851 ret = 0;
1852 }
1853 if (size)
1854 munmap(buf, size);
1855 return ret;
1856}
1857
1858int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1859{
1860 int fd;
1861 char *target;
1862
1863 switch (st->st_mode & S_IFMT) {
1864 case S_IFREG:
1865 fd = open(path, O_RDONLY);
1866 if (fd < 0)
1867 return error("open(\"%s\"): %s", path,
1868 strerror(errno));
1869 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1870 return error("%s: failed to insert into database",
1871 path);
1872 break;
1873 case S_IFLNK:
1874 target = xmalloc(st->st_size+1);
1875 if (readlink(path, target, st->st_size+1) != st->st_size) {
1876 char *errstr = strerror(errno);
1877 free(target);
1878 return error("readlink(\"%s\"): %s", path,
1879 errstr);
1880 }
1881 if (!write_object) {
1882 unsigned char hdr[50];
1883 int hdrlen;
1884 write_sha1_file_prepare(target, st->st_size, blob_type,
1885 sha1, hdr, &hdrlen);
1886 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1887 return error("%s: failed to insert into database",
1888 path);
1889 free(target);
1890 break;
1891 default:
1892 return error("%s: unsupported file type", path);
1893 }
1894 return 0;
1895}