rebase --merge: fix for rebasing more than 7 commits.
[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] = { 0, };
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 "strdup()" if you need to save the
119 * filename.
120 *
121 * Also note that this returns the location for creating. Reading
122 * SHA1 file can happen from any alternate directory listed in the
123 * DB_ENVIRONMENT environment variable if it is not found in
124 * the primary object database.
125 */
126 char *sha1_file_name(const unsigned char *sha1)
127 {
128 static char *name, *base;
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 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
467 pack_mapped += p->pack_size;
468 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
469 ; /* nothing */
470 fd = open(p->pack_name, O_RDONLY);
471 if (fd < 0)
472 die("packfile %s cannot be opened", p->pack_name);
473 if (fstat(fd, &st)) {
474 close(fd);
475 die("packfile %s cannot be opened", p->pack_name);
476 }
477 if (st.st_size != p->pack_size)
478 die("packfile %s size mismatch.", p->pack_name);
479 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
480 close(fd);
481 if (map == MAP_FAILED)
482 die("packfile %s cannot be mapped.", p->pack_name);
483 p->pack_base = map;
484
485 /* Check if the pack file matches with the index file.
486 * this is cheap.
487 */
488 if (memcmp((char*)(p->index_base) + p->index_size - 40,
489 p->pack_base + p->pack_size - 20, 20)) {
490
491 die("packfile %s does not match index.", p->pack_name);
492 }
493 }
494 p->pack_last_used = pack_used_ctr++;
495 p->pack_use_cnt++;
496 return 0;
497 }
498
499 struct packed_git *add_packed_git(char *path, int path_len, int local)
500 {
501 struct stat st;
502 struct packed_git *p;
503 unsigned long idx_size;
504 void *idx_map;
505 unsigned char sha1[20];
506
507 if (check_packed_git_idx(path, &idx_size, &idx_map))
508 return NULL;
509
510 /* do we have a corresponding .pack file? */
511 strcpy(path + path_len - 4, ".pack");
512 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
513 munmap(idx_map, idx_size);
514 return NULL;
515 }
516 /* ok, it looks sane as far as we can check without
517 * actually mapping the pack file.
518 */
519 p = xmalloc(sizeof(*p) + path_len + 2);
520 strcpy(p->pack_name, path);
521 p->index_size = idx_size;
522 p->pack_size = st.st_size;
523 p->index_base = idx_map;
524 p->next = NULL;
525 p->pack_base = NULL;
526 p->pack_last_used = 0;
527 p->pack_use_cnt = 0;
528 p->pack_local = local;
529 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
530 memcpy(p->sha1, sha1, 20);
531 return p;
532 }
533
534 struct packed_git *parse_pack_index(unsigned char *sha1)
535 {
536 char *path = sha1_pack_index_name(sha1);
537 return parse_pack_index_file(sha1, path);
538 }
539
540 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
541 {
542 struct packed_git *p;
543 unsigned long idx_size;
544 void *idx_map;
545 char *path;
546
547 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
548 return NULL;
549
550 path = sha1_pack_name(sha1);
551
552 p = xmalloc(sizeof(*p) + strlen(path) + 2);
553 strcpy(p->pack_name, path);
554 p->index_size = idx_size;
555 p->pack_size = 0;
556 p->index_base = idx_map;
557 p->next = NULL;
558 p->pack_base = NULL;
559 p->pack_last_used = 0;
560 p->pack_use_cnt = 0;
561 memcpy(p->sha1, sha1, 20);
562 return p;
563 }
564
565 void install_packed_git(struct packed_git *pack)
566 {
567 pack->next = packed_git;
568 packed_git = pack;
569 }
570
571 static void prepare_packed_git_one(char *objdir, int local)
572 {
573 char path[PATH_MAX];
574 int len;
575 DIR *dir;
576 struct dirent *de;
577
578 sprintf(path, "%s/pack", objdir);
579 len = strlen(path);
580 dir = opendir(path);
581 if (!dir) {
582 if (errno != ENOENT)
583 error("unable to open object pack directory: %s: %s",
584 path, strerror(errno));
585 return;
586 }
587 path[len++] = '/';
588 while ((de = readdir(dir)) != NULL) {
589 int namelen = strlen(de->d_name);
590 struct packed_git *p;
591
592 if (strcmp(de->d_name + namelen - 4, ".idx"))
593 continue;
594
595 /* we have .idx. Is it a file we can map? */
596 strcpy(path + len, de->d_name);
597 for (p = packed_git; p; p = p->next) {
598 if (!memcmp(path, p->pack_name, len + namelen - 4))
599 break;
600 }
601 if (p)
602 continue;
603 p = add_packed_git(path, len + namelen, local);
604 if (!p)
605 continue;
606 p->next = packed_git;
607 packed_git = p;
608 }
609 closedir(dir);
610 }
611
612 static int prepare_packed_git_run_once = 0;
613 void prepare_packed_git(void)
614 {
615 struct alternate_object_database *alt;
616
617 if (prepare_packed_git_run_once)
618 return;
619 prepare_packed_git_one(get_object_directory(), 1);
620 prepare_alt_odb();
621 for (alt = alt_odb_list; alt; alt = alt->next) {
622 alt->name[-1] = 0;
623 prepare_packed_git_one(alt->base, 0);
624 alt->name[-1] = '/';
625 }
626 prepare_packed_git_run_once = 1;
627 }
628
629 static void reprepare_packed_git(void)
630 {
631 prepare_packed_git_run_once = 0;
632 prepare_packed_git();
633 }
634
635 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
636 {
637 char header[100];
638 unsigned char real_sha1[20];
639 SHA_CTX c;
640
641 SHA1_Init(&c);
642 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
643 SHA1_Update(&c, map, size);
644 SHA1_Final(real_sha1, &c);
645 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
646 }
647
648 static void *map_sha1_file_internal(const unsigned char *sha1,
649 unsigned long *size)
650 {
651 struct stat st;
652 void *map;
653 int fd;
654 char *filename = find_sha1_file(sha1, &st);
655
656 if (!filename) {
657 return NULL;
658 }
659
660 fd = open(filename, O_RDONLY | sha1_file_open_flag);
661 if (fd < 0) {
662 /* See if it works without O_NOATIME */
663 switch (sha1_file_open_flag) {
664 default:
665 fd = open(filename, O_RDONLY);
666 if (fd >= 0)
667 break;
668 /* Fallthrough */
669 case 0:
670 return NULL;
671 }
672
673 /* If it failed once, it will probably fail again.
674 * Stop using O_NOATIME
675 */
676 sha1_file_open_flag = 0;
677 }
678 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
679 close(fd);
680 if (map == MAP_FAILED)
681 return NULL;
682 *size = st.st_size;
683 return map;
684 }
685
686 int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
687 {
688 /* Get the data stream */
689 memset(stream, 0, sizeof(*stream));
690 stream->next_in = map;
691 stream->avail_in = mapsize;
692 stream->next_out = buffer;
693 stream->avail_out = size;
694
695 inflateInit(stream);
696 return inflate(stream, 0);
697 }
698
699 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
700 {
701 int bytes = strlen(buffer) + 1;
702 unsigned char *buf = xmalloc(1+size);
703
704 memcpy(buf, buffer + bytes, stream->total_out - bytes);
705 bytes = stream->total_out - bytes;
706 if (bytes < size) {
707 stream->next_out = buf + bytes;
708 stream->avail_out = size - bytes;
709 while (inflate(stream, Z_FINISH) == Z_OK)
710 /* nothing */;
711 }
712 buf[size] = 0;
713 inflateEnd(stream);
714 return buf;
715 }
716
717 /*
718 * We used to just use "sscanf()", but that's actually way
719 * too permissive for what we want to check. So do an anal
720 * object header parse by hand.
721 */
722 int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
723 {
724 int i;
725 unsigned long size;
726
727 /*
728 * The type can be at most ten bytes (including the
729 * terminating '\0' that we add), and is followed by
730 * a space.
731 */
732 i = 10;
733 for (;;) {
734 char c = *hdr++;
735 if (c == ' ')
736 break;
737 if (!--i)
738 return -1;
739 *type++ = c;
740 }
741 *type = 0;
742
743 /*
744 * The length must follow immediately, and be in canonical
745 * decimal format (ie "010" is not valid).
746 */
747 size = *hdr++ - '0';
748 if (size > 9)
749 return -1;
750 if (size) {
751 for (;;) {
752 unsigned long c = *hdr - '0';
753 if (c > 9)
754 break;
755 hdr++;
756 size = size * 10 + c;
757 }
758 }
759 *sizep = size;
760
761 /*
762 * The length must be followed by a zero byte
763 */
764 return *hdr ? -1 : 0;
765 }
766
767 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
768 {
769 int ret;
770 z_stream stream;
771 char hdr[8192];
772
773 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
774 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
775 return NULL;
776
777 return unpack_sha1_rest(&stream, hdr, *size);
778 }
779
780 /* forward declaration for a mutually recursive function */
781 static int packed_object_info(struct pack_entry *entry,
782 char *type, unsigned long *sizep);
783
784 static int packed_delta_info(unsigned char *base_sha1,
785 unsigned long delta_size,
786 unsigned long left,
787 char *type,
788 unsigned long *sizep,
789 struct packed_git *p)
790 {
791 struct pack_entry base_ent;
792
793 if (left < 20)
794 die("truncated pack file");
795
796 /* The base entry _must_ be in the same pack */
797 if (!find_pack_entry_one(base_sha1, &base_ent, p))
798 die("failed to find delta-pack base object %s",
799 sha1_to_hex(base_sha1));
800
801 /* We choose to only get the type of the base object and
802 * ignore potentially corrupt pack file that expects the delta
803 * based on a base with a wrong size. This saves tons of
804 * inflate() calls.
805 */
806
807 if (packed_object_info(&base_ent, type, NULL))
808 die("cannot get info for delta-pack base");
809
810 if (sizep) {
811 const unsigned char *data;
812 unsigned char delta_head[64];
813 unsigned long result_size;
814 z_stream stream;
815 int st;
816
817 memset(&stream, 0, sizeof(stream));
818
819 data = stream.next_in = base_sha1 + 20;
820 stream.avail_in = left - 20;
821 stream.next_out = delta_head;
822 stream.avail_out = sizeof(delta_head);
823
824 inflateInit(&stream);
825 st = inflate(&stream, Z_FINISH);
826 inflateEnd(&stream);
827 if ((st != Z_STREAM_END) &&
828 stream.total_out != sizeof(delta_head))
829 die("delta data unpack-initial failed");
830
831 /* Examine the initial part of the delta to figure out
832 * the result size.
833 */
834 data = delta_head;
835
836 /* ignore base size */
837 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
838
839 /* Read the result size */
840 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
841 *sizep = result_size;
842 }
843 return 0;
844 }
845
846 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
847 enum object_type *type, unsigned long *sizep)
848 {
849 unsigned shift;
850 unsigned char *pack, c;
851 unsigned long size;
852
853 if (offset >= p->pack_size)
854 die("object offset outside of pack file");
855
856 pack = p->pack_base + offset;
857 c = *pack++;
858 offset++;
859 *type = (c >> 4) & 7;
860 size = c & 15;
861 shift = 4;
862 while (c & 0x80) {
863 if (offset >= p->pack_size)
864 die("object offset outside of pack file");
865 c = *pack++;
866 offset++;
867 size += (c & 0x7f) << shift;
868 shift += 7;
869 }
870 *sizep = size;
871 return offset;
872 }
873
874 int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
875 unsigned char *base, unsigned long *sizep,
876 enum object_type *kindp)
877 {
878 unsigned long ptr;
879 int status = -1;
880
881 use_packed_git(p);
882 ptr = offset;
883 ptr = unpack_object_header(p, ptr, kindp, sizep);
884 if (*kindp != OBJ_DELTA)
885 goto done;
886 memcpy(base, p->pack_base + ptr, 20);
887 status = 0;
888 done:
889 unuse_packed_git(p);
890 return status;
891 }
892
893 void packed_object_info_detail(struct pack_entry *e,
894 char *type,
895 unsigned long *size,
896 unsigned long *store_size,
897 unsigned int *delta_chain_length,
898 unsigned char *base_sha1)
899 {
900 struct packed_git *p = e->p;
901 unsigned long offset;
902 unsigned char *pack;
903 enum object_type kind;
904
905 offset = unpack_object_header(p, e->offset, &kind, size);
906 pack = p->pack_base + offset;
907 if (kind != OBJ_DELTA)
908 *delta_chain_length = 0;
909 else {
910 unsigned int chain_length = 0;
911 if (p->pack_size <= offset + 20)
912 die("pack file %s records an incomplete delta base",
913 p->pack_name);
914 memcpy(base_sha1, pack, 20);
915 do {
916 struct pack_entry base_ent;
917 unsigned long junk;
918
919 find_pack_entry_one(pack, &base_ent, p);
920 offset = unpack_object_header(p, base_ent.offset,
921 &kind, &junk);
922 pack = p->pack_base + offset;
923 chain_length++;
924 } while (kind == OBJ_DELTA);
925 *delta_chain_length = chain_length;
926 }
927 switch (kind) {
928 case OBJ_COMMIT:
929 strcpy(type, commit_type);
930 break;
931 case OBJ_TREE:
932 strcpy(type, tree_type);
933 break;
934 case OBJ_BLOB:
935 strcpy(type, blob_type);
936 break;
937 case OBJ_TAG:
938 strcpy(type, tag_type);
939 break;
940 default:
941 die("corrupted pack file %s containing object of kind %d",
942 p->pack_name, kind);
943 }
944 *store_size = 0; /* notyet */
945 }
946
947 static int packed_object_info(struct pack_entry *entry,
948 char *type, unsigned long *sizep)
949 {
950 struct packed_git *p = entry->p;
951 unsigned long offset, size, left;
952 unsigned char *pack;
953 enum object_type kind;
954 int retval;
955
956 if (use_packed_git(p))
957 die("cannot map packed file");
958
959 offset = unpack_object_header(p, entry->offset, &kind, &size);
960 pack = p->pack_base + offset;
961 left = p->pack_size - offset;
962
963 switch (kind) {
964 case OBJ_DELTA:
965 retval = packed_delta_info(pack, size, left, type, sizep, p);
966 unuse_packed_git(p);
967 return retval;
968 case OBJ_COMMIT:
969 strcpy(type, commit_type);
970 break;
971 case OBJ_TREE:
972 strcpy(type, tree_type);
973 break;
974 case OBJ_BLOB:
975 strcpy(type, blob_type);
976 break;
977 case OBJ_TAG:
978 strcpy(type, tag_type);
979 break;
980 default:
981 die("corrupted pack file %s containing object of kind %d",
982 p->pack_name, kind);
983 }
984 if (sizep)
985 *sizep = size;
986 unuse_packed_git(p);
987 return 0;
988 }
989
990 /* forward declaration for a mutually recursive function */
991 static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
992
993 static void *unpack_delta_entry(unsigned char *base_sha1,
994 unsigned long delta_size,
995 unsigned long left,
996 char *type,
997 unsigned long *sizep,
998 struct packed_git *p)
999 {
1000 struct pack_entry base_ent;
1001 void *data, *delta_data, *result, *base;
1002 unsigned long data_size, result_size, base_size;
1003 z_stream stream;
1004 int st;
1005
1006 if (left < 20)
1007 die("truncated pack file");
1008
1009 /* The base entry _must_ be in the same pack */
1010 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1011 die("failed to find delta-pack base object %s",
1012 sha1_to_hex(base_sha1));
1013 base = unpack_entry_gently(&base_ent, type, &base_size);
1014 if (!base)
1015 die("failed to read delta-pack base object %s",
1016 sha1_to_hex(base_sha1));
1017
1018 data = base_sha1 + 20;
1019 data_size = left - 20;
1020 delta_data = xmalloc(delta_size);
1021
1022 memset(&stream, 0, sizeof(stream));
1023
1024 stream.next_in = data;
1025 stream.avail_in = data_size;
1026 stream.next_out = delta_data;
1027 stream.avail_out = delta_size;
1028
1029 inflateInit(&stream);
1030 st = inflate(&stream, Z_FINISH);
1031 inflateEnd(&stream);
1032 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
1033 die("delta data unpack failed");
1034
1035 result = patch_delta(base, base_size,
1036 delta_data, delta_size,
1037 &result_size);
1038 if (!result)
1039 die("failed to apply delta");
1040 free(delta_data);
1041 free(base);
1042 *sizep = result_size;
1043 return result;
1044 }
1045
1046 static void *unpack_non_delta_entry(unsigned char *data,
1047 unsigned long size,
1048 unsigned long left)
1049 {
1050 int st;
1051 z_stream stream;
1052 unsigned char *buffer;
1053
1054 buffer = xmalloc(size + 1);
1055 buffer[size] = 0;
1056 memset(&stream, 0, sizeof(stream));
1057 stream.next_in = data;
1058 stream.avail_in = left;
1059 stream.next_out = buffer;
1060 stream.avail_out = size;
1061
1062 inflateInit(&stream);
1063 st = inflate(&stream, Z_FINISH);
1064 inflateEnd(&stream);
1065 if ((st != Z_STREAM_END) || stream.total_out != size) {
1066 free(buffer);
1067 return NULL;
1068 }
1069
1070 return buffer;
1071 }
1072
1073 static void *unpack_entry(struct pack_entry *entry,
1074 char *type, unsigned long *sizep)
1075 {
1076 struct packed_git *p = entry->p;
1077 void *retval;
1078
1079 if (use_packed_git(p))
1080 die("cannot map packed file");
1081 retval = unpack_entry_gently(entry, type, sizep);
1082 unuse_packed_git(p);
1083 if (!retval)
1084 die("corrupted pack file %s", p->pack_name);
1085 return retval;
1086 }
1087
1088 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1089 void *unpack_entry_gently(struct pack_entry *entry,
1090 char *type, unsigned long *sizep)
1091 {
1092 struct packed_git *p = entry->p;
1093 unsigned long offset, size, left;
1094 unsigned char *pack;
1095 enum object_type kind;
1096 void *retval;
1097
1098 offset = unpack_object_header(p, entry->offset, &kind, &size);
1099 pack = p->pack_base + offset;
1100 left = p->pack_size - offset;
1101 switch (kind) {
1102 case OBJ_DELTA:
1103 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
1104 return retval;
1105 case OBJ_COMMIT:
1106 strcpy(type, commit_type);
1107 break;
1108 case OBJ_TREE:
1109 strcpy(type, tree_type);
1110 break;
1111 case OBJ_BLOB:
1112 strcpy(type, blob_type);
1113 break;
1114 case OBJ_TAG:
1115 strcpy(type, tag_type);
1116 break;
1117 default:
1118 return NULL;
1119 }
1120 *sizep = size;
1121 retval = unpack_non_delta_entry(pack, size, left);
1122 return retval;
1123 }
1124
1125 int num_packed_objects(const struct packed_git *p)
1126 {
1127 /* See check_packed_git_idx() */
1128 return (p->index_size - 20 - 20 - 4*256) / 24;
1129 }
1130
1131 int nth_packed_object_sha1(const struct packed_git *p, int n,
1132 unsigned char* sha1)
1133 {
1134 void *index = p->index_base + 256;
1135 if (n < 0 || num_packed_objects(p) <= n)
1136 return -1;
1137 memcpy(sha1, (index + 24 * n + 4), 20);
1138 return 0;
1139 }
1140
1141 int find_pack_entry_one(const unsigned char *sha1,
1142 struct pack_entry *e, struct packed_git *p)
1143 {
1144 unsigned int *level1_ofs = p->index_base;
1145 int hi = ntohl(level1_ofs[*sha1]);
1146 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1147 void *index = p->index_base + 256;
1148
1149 do {
1150 int mi = (lo + hi) / 2;
1151 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
1152 if (!cmp) {
1153 e->offset = ntohl(*((unsigned int *)(index + 24 * mi)));
1154 memcpy(e->sha1, sha1, 20);
1155 e->p = p;
1156 return 1;
1157 }
1158 if (cmp > 0)
1159 hi = mi;
1160 else
1161 lo = mi+1;
1162 } while (lo < hi);
1163 return 0;
1164 }
1165
1166 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1167 {
1168 struct packed_git *p;
1169 prepare_packed_git();
1170
1171 for (p = packed_git; p; p = p->next) {
1172 if (find_pack_entry_one(sha1, e, p))
1173 return 1;
1174 }
1175 return 0;
1176 }
1177
1178 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1179 struct packed_git *packs)
1180 {
1181 struct packed_git *p;
1182 struct pack_entry e;
1183
1184 for (p = packs; p; p = p->next) {
1185 if (find_pack_entry_one(sha1, &e, p))
1186 return p;
1187 }
1188 return NULL;
1189
1190 }
1191
1192 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1193 {
1194 int status;
1195 unsigned long mapsize, size;
1196 void *map;
1197 z_stream stream;
1198 char hdr[128];
1199
1200 map = map_sha1_file_internal(sha1, &mapsize);
1201 if (!map) {
1202 struct pack_entry e;
1203
1204 if (find_pack_entry(sha1, &e))
1205 return packed_object_info(&e, type, sizep);
1206 reprepare_packed_git();
1207 if (find_pack_entry(sha1, &e))
1208 return packed_object_info(&e, type, sizep);
1209 return error("unable to find %s", sha1_to_hex(sha1));
1210 }
1211 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1212 status = error("unable to unpack %s header",
1213 sha1_to_hex(sha1));
1214 if (parse_sha1_header(hdr, type, &size) < 0)
1215 status = error("unable to parse %s header", sha1_to_hex(sha1));
1216 else {
1217 status = 0;
1218 if (sizep)
1219 *sizep = size;
1220 }
1221 inflateEnd(&stream);
1222 munmap(map, mapsize);
1223 return status;
1224 }
1225
1226 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1227 {
1228 struct pack_entry e;
1229
1230 if (!find_pack_entry(sha1, &e)) {
1231 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1232 return NULL;
1233 }
1234 return unpack_entry(&e, type, size);
1235 }
1236
1237 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1238 {
1239 unsigned long mapsize;
1240 void *map, *buf;
1241 struct pack_entry e;
1242
1243 if (find_pack_entry(sha1, &e))
1244 return read_packed_sha1(sha1, type, size);
1245 map = map_sha1_file_internal(sha1, &mapsize);
1246 if (map) {
1247 buf = unpack_sha1_file(map, mapsize, type, size);
1248 munmap(map, mapsize);
1249 return buf;
1250 }
1251 reprepare_packed_git();
1252 if (find_pack_entry(sha1, &e))
1253 return read_packed_sha1(sha1, type, size);
1254 return NULL;
1255 }
1256
1257 void *read_object_with_reference(const unsigned char *sha1,
1258 const char *required_type,
1259 unsigned long *size,
1260 unsigned char *actual_sha1_return)
1261 {
1262 char type[20];
1263 void *buffer;
1264 unsigned long isize;
1265 unsigned char actual_sha1[20];
1266
1267 memcpy(actual_sha1, sha1, 20);
1268 while (1) {
1269 int ref_length = -1;
1270 const char *ref_type = NULL;
1271
1272 buffer = read_sha1_file(actual_sha1, type, &isize);
1273 if (!buffer)
1274 return NULL;
1275 if (!strcmp(type, required_type)) {
1276 *size = isize;
1277 if (actual_sha1_return)
1278 memcpy(actual_sha1_return, actual_sha1, 20);
1279 return buffer;
1280 }
1281 /* Handle references */
1282 else if (!strcmp(type, commit_type))
1283 ref_type = "tree ";
1284 else if (!strcmp(type, tag_type))
1285 ref_type = "object ";
1286 else {
1287 free(buffer);
1288 return NULL;
1289 }
1290 ref_length = strlen(ref_type);
1291
1292 if (memcmp(buffer, ref_type, ref_length) ||
1293 get_sha1_hex(buffer + ref_length, actual_sha1)) {
1294 free(buffer);
1295 return NULL;
1296 }
1297 free(buffer);
1298 /* Now we have the ID of the referred-to object in
1299 * actual_sha1. Check again. */
1300 }
1301 }
1302
1303 char *write_sha1_file_prepare(void *buf,
1304 unsigned long len,
1305 const char *type,
1306 unsigned char *sha1,
1307 unsigned char *hdr,
1308 int *hdrlen)
1309 {
1310 SHA_CTX c;
1311
1312 /* Generate the header */
1313 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1314
1315 /* Sha1.. */
1316 SHA1_Init(&c);
1317 SHA1_Update(&c, hdr, *hdrlen);
1318 SHA1_Update(&c, buf, len);
1319 SHA1_Final(sha1, &c);
1320
1321 return sha1_file_name(sha1);
1322 }
1323
1324 /*
1325 * Link the tempfile to the final place, possibly creating the
1326 * last directory level as you do so.
1327 *
1328 * Returns the errno on failure, 0 on success.
1329 */
1330 static int link_temp_to_file(const char *tmpfile, char *filename)
1331 {
1332 int ret;
1333
1334 if (!link(tmpfile, filename))
1335 return 0;
1336
1337 /*
1338 * Try to mkdir the last path component if that failed
1339 * with an ENOENT.
1340 *
1341 * Re-try the "link()" regardless of whether the mkdir
1342 * succeeds, since a race might mean that somebody
1343 * else succeeded.
1344 */
1345 ret = errno;
1346 if (ret == ENOENT) {
1347 char *dir = strrchr(filename, '/');
1348 if (dir) {
1349 *dir = 0;
1350 mkdir(filename, 0777);
1351 if (adjust_shared_perm(filename))
1352 return -2;
1353 *dir = '/';
1354 if (!link(tmpfile, filename))
1355 return 0;
1356 ret = errno;
1357 }
1358 }
1359 return ret;
1360 }
1361
1362 /*
1363 * Move the just written object into its final resting place
1364 */
1365 int move_temp_to_file(const char *tmpfile, char *filename)
1366 {
1367 int ret = link_temp_to_file(tmpfile, filename);
1368
1369 /*
1370 * Coda hack - coda doesn't like cross-directory links,
1371 * so we fall back to a rename, which will mean that it
1372 * won't be able to check collisions, but that's not a
1373 * big deal.
1374 *
1375 * The same holds for FAT formatted media.
1376 *
1377 * When this succeeds, we just return 0. We have nothing
1378 * left to unlink.
1379 */
1380 if (ret && ret != EEXIST) {
1381 if (!rename(tmpfile, filename))
1382 return 0;
1383 ret = errno;
1384 }
1385 unlink(tmpfile);
1386 if (ret) {
1387 if (ret != EEXIST) {
1388 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1389 return -1;
1390 }
1391 /* FIXME!!! Collision check here ? */
1392 }
1393
1394 return 0;
1395 }
1396
1397 static int write_buffer(int fd, const void *buf, size_t len)
1398 {
1399 while (len) {
1400 ssize_t size;
1401
1402 size = write(fd, buf, len);
1403 if (!size)
1404 return error("file write: disk full");
1405 if (size < 0) {
1406 if (errno == EINTR || errno == EAGAIN)
1407 continue;
1408 return error("file write error (%s)", strerror(errno));
1409 }
1410 len -= size;
1411 buf += size;
1412 }
1413 return 0;
1414 }
1415
1416 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1417 {
1418 int size;
1419 unsigned char *compressed;
1420 z_stream stream;
1421 unsigned char sha1[20];
1422 char *filename;
1423 static char tmpfile[PATH_MAX];
1424 unsigned char hdr[50];
1425 int fd, hdrlen;
1426
1427 /* Normally if we have it in the pack then we do not bother writing
1428 * it out into .git/objects/??/?{38} file.
1429 */
1430 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1431 if (returnsha1)
1432 memcpy(returnsha1, sha1, 20);
1433 if (has_sha1_file(sha1))
1434 return 0;
1435 fd = open(filename, O_RDONLY);
1436 if (fd >= 0) {
1437 /*
1438 * FIXME!!! We might do collision checking here, but we'd
1439 * need to uncompress the old file and check it. Later.
1440 */
1441 close(fd);
1442 return 0;
1443 }
1444
1445 if (errno != ENOENT) {
1446 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1447 return -1;
1448 }
1449
1450 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1451
1452 fd = mkstemp(tmpfile);
1453 if (fd < 0) {
1454 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1455 return -1;
1456 }
1457
1458 /* Set it up */
1459 memset(&stream, 0, sizeof(stream));
1460 deflateInit(&stream, Z_BEST_COMPRESSION);
1461 size = deflateBound(&stream, len+hdrlen);
1462 compressed = xmalloc(size);
1463
1464 /* Compress it */
1465 stream.next_out = compressed;
1466 stream.avail_out = size;
1467
1468 /* First header.. */
1469 stream.next_in = hdr;
1470 stream.avail_in = hdrlen;
1471 while (deflate(&stream, 0) == Z_OK)
1472 /* nothing */;
1473
1474 /* Then the data itself.. */
1475 stream.next_in = buf;
1476 stream.avail_in = len;
1477 while (deflate(&stream, Z_FINISH) == Z_OK)
1478 /* nothing */;
1479 deflateEnd(&stream);
1480 size = stream.total_out;
1481
1482 if (write_buffer(fd, compressed, size) < 0)
1483 die("unable to write sha1 file");
1484 fchmod(fd, 0444);
1485 close(fd);
1486 free(compressed);
1487
1488 return move_temp_to_file(tmpfile, filename);
1489 }
1490
1491 /*
1492 * We need to unpack and recompress the object for writing
1493 * it out to a different file.
1494 */
1495 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1496 {
1497 size_t size;
1498 z_stream stream;
1499 unsigned char *unpacked;
1500 unsigned long len;
1501 char type[20];
1502 char hdr[50];
1503 int hdrlen;
1504 void *buf;
1505
1506 // need to unpack and recompress it by itself
1507 unpacked = read_packed_sha1(sha1, type, &len);
1508
1509 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1510
1511 /* Set it up */
1512 memset(&stream, 0, sizeof(stream));
1513 deflateInit(&stream, Z_BEST_COMPRESSION);
1514 size = deflateBound(&stream, len + hdrlen);
1515 buf = xmalloc(size);
1516
1517 /* Compress it */
1518 stream.next_out = buf;
1519 stream.avail_out = size;
1520
1521 /* First header.. */
1522 stream.next_in = (void *)hdr;
1523 stream.avail_in = hdrlen;
1524 while (deflate(&stream, 0) == Z_OK)
1525 /* nothing */;
1526
1527 /* Then the data itself.. */
1528 stream.next_in = unpacked;
1529 stream.avail_in = len;
1530 while (deflate(&stream, Z_FINISH) == Z_OK)
1531 /* nothing */;
1532 deflateEnd(&stream);
1533 free(unpacked);
1534
1535 *objsize = stream.total_out;
1536 return buf;
1537 }
1538
1539 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1540 {
1541 int retval;
1542 unsigned long objsize;
1543 void *buf = map_sha1_file_internal(sha1, &objsize);
1544
1545 if (buf) {
1546 retval = write_buffer(fd, buf, objsize);
1547 munmap(buf, objsize);
1548 return retval;
1549 }
1550
1551 buf = repack_object(sha1, &objsize);
1552 retval = write_buffer(fd, buf, objsize);
1553 free(buf);
1554 return retval;
1555 }
1556
1557 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1558 size_t bufsize, size_t *bufposn)
1559 {
1560 char tmpfile[PATH_MAX];
1561 int local;
1562 z_stream stream;
1563 unsigned char real_sha1[20];
1564 unsigned char discard[4096];
1565 int ret;
1566 SHA_CTX c;
1567
1568 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1569
1570 local = mkstemp(tmpfile);
1571 if (local < 0)
1572 return error("Couldn't open %s for %s",
1573 tmpfile, sha1_to_hex(sha1));
1574
1575 memset(&stream, 0, sizeof(stream));
1576
1577 inflateInit(&stream);
1578
1579 SHA1_Init(&c);
1580
1581 do {
1582 ssize_t size;
1583 if (*bufposn) {
1584 stream.avail_in = *bufposn;
1585 stream.next_in = (unsigned char *) buffer;
1586 do {
1587 stream.next_out = discard;
1588 stream.avail_out = sizeof(discard);
1589 ret = inflate(&stream, Z_SYNC_FLUSH);
1590 SHA1_Update(&c, discard, sizeof(discard) -
1591 stream.avail_out);
1592 } while (stream.avail_in && ret == Z_OK);
1593 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1594 die("unable to write sha1 file");
1595 memmove(buffer, buffer + *bufposn - stream.avail_in,
1596 stream.avail_in);
1597 *bufposn = stream.avail_in;
1598 if (ret != Z_OK)
1599 break;
1600 }
1601 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1602 if (size <= 0) {
1603 close(local);
1604 unlink(tmpfile);
1605 if (!size)
1606 return error("Connection closed?");
1607 perror("Reading from connection");
1608 return -1;
1609 }
1610 *bufposn += size;
1611 } while (1);
1612 inflateEnd(&stream);
1613
1614 close(local);
1615 SHA1_Final(real_sha1, &c);
1616 if (ret != Z_STREAM_END) {
1617 unlink(tmpfile);
1618 return error("File %s corrupted", sha1_to_hex(sha1));
1619 }
1620 if (memcmp(sha1, real_sha1, 20)) {
1621 unlink(tmpfile);
1622 return error("File %s has bad hash", sha1_to_hex(sha1));
1623 }
1624
1625 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1626 }
1627
1628 int has_pack_index(const unsigned char *sha1)
1629 {
1630 struct stat st;
1631 if (stat(sha1_pack_index_name(sha1), &st))
1632 return 0;
1633 return 1;
1634 }
1635
1636 int has_pack_file(const unsigned char *sha1)
1637 {
1638 struct stat st;
1639 if (stat(sha1_pack_name(sha1), &st))
1640 return 0;
1641 return 1;
1642 }
1643
1644 int has_sha1_pack(const unsigned char *sha1)
1645 {
1646 struct pack_entry e;
1647 return find_pack_entry(sha1, &e);
1648 }
1649
1650 int has_sha1_file(const unsigned char *sha1)
1651 {
1652 struct stat st;
1653 struct pack_entry e;
1654
1655 if (find_pack_entry(sha1, &e))
1656 return 1;
1657 return find_sha1_file(sha1, &st) ? 1 : 0;
1658 }
1659
1660 /*
1661 * reads from fd as long as possible into a supplied buffer of size bytes.
1662 * If neccessary the buffer's size is increased using realloc()
1663 *
1664 * returns 0 if anything went fine and -1 otherwise
1665 *
1666 * NOTE: both buf and size may change, but even when -1 is returned
1667 * you still have to free() it yourself.
1668 */
1669 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1670 {
1671 char* buf = *return_buf;
1672 unsigned long size = *return_size;
1673 int iret;
1674 unsigned long off = 0;
1675
1676 do {
1677 iret = xread(fd, buf + off, size - off);
1678 if (iret > 0) {
1679 off += iret;
1680 if (off == size) {
1681 size *= 2;
1682 buf = realloc(buf, size);
1683 }
1684 }
1685 } while (iret > 0);
1686
1687 *return_buf = buf;
1688 *return_size = off;
1689
1690 if (iret < 0)
1691 return -1;
1692 return 0;
1693 }
1694
1695 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1696 {
1697 unsigned long size = 4096;
1698 char *buf = malloc(size);
1699 int ret;
1700 unsigned char hdr[50];
1701 int hdrlen;
1702
1703 if (read_pipe(fd, &buf, &size)) {
1704 free(buf);
1705 return -1;
1706 }
1707
1708 if (!type)
1709 type = blob_type;
1710 if (write_object)
1711 ret = write_sha1_file(buf, size, type, sha1);
1712 else {
1713 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1714 ret = 0;
1715 }
1716 free(buf);
1717 return ret;
1718 }
1719
1720 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1721 {
1722 unsigned long size = st->st_size;
1723 void *buf;
1724 int ret;
1725 unsigned char hdr[50];
1726 int hdrlen;
1727
1728 buf = "";
1729 if (size)
1730 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1731 close(fd);
1732 if (buf == MAP_FAILED)
1733 return -1;
1734
1735 if (!type)
1736 type = blob_type;
1737 if (write_object)
1738 ret = write_sha1_file(buf, size, type, sha1);
1739 else {
1740 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1741 ret = 0;
1742 }
1743 if (size)
1744 munmap(buf, size);
1745 return ret;
1746 }
1747
1748 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1749 {
1750 int fd;
1751 char *target;
1752
1753 switch (st->st_mode & S_IFMT) {
1754 case S_IFREG:
1755 fd = open(path, O_RDONLY);
1756 if (fd < 0)
1757 return error("open(\"%s\"): %s", path,
1758 strerror(errno));
1759 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1760 return error("%s: failed to insert into database",
1761 path);
1762 break;
1763 case S_IFLNK:
1764 target = xmalloc(st->st_size+1);
1765 if (readlink(path, target, st->st_size+1) != st->st_size) {
1766 char *errstr = strerror(errno);
1767 free(target);
1768 return error("readlink(\"%s\"): %s", path,
1769 errstr);
1770 }
1771 if (!write_object) {
1772 unsigned char hdr[50];
1773 int hdrlen;
1774 write_sha1_file_prepare(target, st->st_size, blob_type,
1775 sha1, hdr, &hdrlen);
1776 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1777 return error("%s: failed to insert into database",
1778 path);
1779 free(target);
1780 break;
1781 default:
1782 return error("%s: unsupported file type", path);
1783 }
1784 return 0;
1785 }