[PATCH] Bugfix: initialize pack_base to NULL.
[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 <sys/types.h>
10 #include <dirent.h>
11 #include "cache.h"
12 #include "delta.h"
13 #include "pack.h"
14
15 #ifndef O_NOATIME
16 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
17 #define O_NOATIME 01000000
18 #else
19 #define O_NOATIME 0
20 #endif
21 #endif
22
23 static unsigned int sha1_file_open_flag = O_NOATIME;
24
25 static unsigned hexval(char c)
26 {
27 if (c >= '0' && c <= '9')
28 return c - '0';
29 if (c >= 'a' && c <= 'f')
30 return c - 'a' + 10;
31 if (c >= 'A' && c <= 'F')
32 return c - 'A' + 10;
33 return ~0;
34 }
35
36 int get_sha1_hex(const char *hex, unsigned char *sha1)
37 {
38 int i;
39 for (i = 0; i < 20; i++) {
40 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
41 if (val & ~0xff)
42 return -1;
43 *sha1++ = val;
44 hex += 2;
45 }
46 return 0;
47 }
48
49 static int get_sha1_file(const char *path, unsigned char *result)
50 {
51 char buffer[60];
52 int fd = open(path, O_RDONLY);
53 int len;
54
55 if (fd < 0)
56 return -1;
57 len = read(fd, buffer, sizeof(buffer));
58 close(fd);
59 if (len < 40)
60 return -1;
61 return get_sha1_hex(buffer, result);
62 }
63
64 static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir;
65 static void setup_git_env(void)
66 {
67 git_dir = gitenv(GIT_DIR_ENVIRONMENT);
68 if (!git_dir)
69 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
70 git_object_dir = gitenv(DB_ENVIRONMENT);
71 if (!git_object_dir) {
72 git_object_dir = xmalloc(strlen(git_dir) + 9);
73 sprintf(git_object_dir, "%s/objects", git_dir);
74 }
75 git_refs_dir = xmalloc(strlen(git_dir) + 6);
76 sprintf(git_refs_dir, "%s/refs", git_dir);
77 git_index_file = gitenv(INDEX_ENVIRONMENT);
78 if (!git_index_file) {
79 git_index_file = xmalloc(strlen(git_dir) + 7);
80 sprintf(git_index_file, "%s/index", git_dir);
81 }
82 }
83
84 char *get_object_directory(void)
85 {
86 if (!git_object_dir)
87 setup_git_env();
88 return git_object_dir;
89 }
90
91 char *get_refs_directory(void)
92 {
93 if (!git_refs_dir)
94 setup_git_env();
95 return git_refs_dir;
96 }
97
98 char *get_index_file(void)
99 {
100 if (!git_index_file)
101 setup_git_env();
102 return git_index_file;
103 }
104
105 int get_sha1(const char *str, unsigned char *sha1)
106 {
107 static char pathname[PATH_MAX];
108 static const char *prefix[] = {
109 "",
110 "refs",
111 "refs/tags",
112 "refs/heads",
113 "refs/snap",
114 NULL
115 };
116 const char **p;
117
118 if (!get_sha1_hex(str, sha1))
119 return 0;
120
121 if (!git_dir)
122 setup_git_env();
123 for (p = prefix; *p; p++) {
124 snprintf(pathname, sizeof(pathname), "%s/%s/%s",
125 git_dir, *p, str);
126 if (!get_sha1_file(pathname, sha1))
127 return 0;
128 }
129
130 return -1;
131 }
132
133 char * sha1_to_hex(const unsigned char *sha1)
134 {
135 static char buffer[50];
136 static const char hex[] = "0123456789abcdef";
137 char *buf = buffer;
138 int i;
139
140 for (i = 0; i < 20; i++) {
141 unsigned int val = *sha1++;
142 *buf++ = hex[val >> 4];
143 *buf++ = hex[val & 0xf];
144 }
145 return buffer;
146 }
147
148 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
149 {
150 int i;
151 for (i = 0; i < 20; i++) {
152 static char hex[] = "0123456789abcdef";
153 unsigned int val = sha1[i];
154 char *pos = pathbuf + i*2 + (i > 0);
155 *pos++ = hex[val >> 4];
156 *pos = hex[val & 0xf];
157 }
158 }
159
160 /*
161 * NOTE! This returns a statically allocated buffer, so you have to be
162 * careful about using it. Do a "strdup()" if you need to save the
163 * filename.
164 *
165 * Also note that this returns the location for creating. Reading
166 * SHA1 file can happen from any alternate directory listed in the
167 * DB_ENVIRONMENT environment variable if it is not found in
168 * the primary object database.
169 */
170 char *sha1_file_name(const unsigned char *sha1)
171 {
172 static char *name, *base;
173
174 if (!base) {
175 const char *sha1_file_directory = get_object_directory();
176 int len = strlen(sha1_file_directory);
177 base = xmalloc(len + 60);
178 memcpy(base, sha1_file_directory, len);
179 memset(base+len, 0, 60);
180 base[len] = '/';
181 base[len+3] = '/';
182 name = base + len + 1;
183 }
184 fill_sha1_path(name, sha1);
185 return base;
186 }
187
188 static struct alternate_object_database {
189 char *base;
190 char *name;
191 } *alt_odb;
192
193 /*
194 * Prepare alternate object database registry.
195 * alt_odb points at an array of struct alternate_object_database.
196 * This array is terminated with an element that has both its base
197 * and name set to NULL. alt_odb[n] comes from n'th non-empty
198 * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
199 * variable, and its base points at a statically allocated buffer
200 * that contains "/the/directory/corresponding/to/.git/objects/...",
201 * while its name points just after the slash at the end of
202 * ".git/objects/" in the example above, and has enough space to hold
203 * 40-byte hex SHA1, an extra slash for the first level indirection,
204 * and the terminating NUL.
205 * This function allocates the alt_odb array and all the strings
206 * pointed by base fields of the array elements with one xmalloc();
207 * the string pool immediately follows the array.
208 */
209 static void prepare_alt_odb(void)
210 {
211 int pass, totlen, i;
212 const char *cp, *last;
213 char *op = NULL;
214 const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
215
216 /* The first pass counts how large an area to allocate to
217 * hold the entire alt_odb structure, including array of
218 * structs and path buffers for them. The second pass fills
219 * the structure and prepares the path buffers for use by
220 * fill_sha1_path().
221 */
222 for (totlen = pass = 0; pass < 2; pass++) {
223 last = alt;
224 i = 0;
225 do {
226 cp = strchr(last, ':') ? : last + strlen(last);
227 if (last != cp) {
228 /* 43 = 40-byte + 2 '/' + terminating NUL */
229 int pfxlen = cp - last;
230 int entlen = pfxlen + 43;
231 if (pass == 0)
232 totlen += entlen;
233 else {
234 alt_odb[i].base = op;
235 alt_odb[i].name = op + pfxlen + 1;
236 memcpy(op, last, pfxlen);
237 op[pfxlen] = op[pfxlen + 3] = '/';
238 op[entlen-1] = 0;
239 op += entlen;
240 }
241 i++;
242 }
243 while (*cp && *cp == ':')
244 cp++;
245 last = cp;
246 } while (*cp);
247 if (pass)
248 break;
249 alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
250 alt_odb[i].base = alt_odb[i].name = NULL;
251 op = (char*)(&alt_odb[i+1]);
252 }
253 }
254
255 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
256 {
257 int i;
258 char *name = sha1_file_name(sha1);
259
260 if (!stat(name, st))
261 return name;
262 if (!alt_odb)
263 prepare_alt_odb();
264 for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
265 fill_sha1_path(name, sha1);
266 if (!stat(alt_odb[i].base, st))
267 return alt_odb[i].base;
268 }
269 return NULL;
270 }
271
272 #define PACK_MAX_SZ (1<<26)
273 static int pack_used_ctr;
274 static unsigned long pack_mapped;
275 static struct packed_git {
276 struct packed_git *next;
277 unsigned long index_size;
278 unsigned long pack_size;
279 unsigned int *index_base;
280 void *pack_base;
281 unsigned int pack_last_used;
282 char pack_name[0]; /* something like ".git/objects/pack/xxxxx.pack" */
283 } *packed_git;
284
285 struct pack_entry {
286 unsigned int offset;
287 unsigned char sha1[20];
288 struct packed_git *p;
289 };
290
291 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
292 void **idx_map_)
293 {
294 void *idx_map;
295 unsigned int *index;
296 unsigned long idx_size;
297 int nr, i;
298 int fd = open(path, O_RDONLY);
299 struct stat st;
300 if (fd < 0)
301 return -1;
302 if (fstat(fd, &st)) {
303 close(fd);
304 return -1;
305 }
306 idx_size = st.st_size;
307 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
308 close(fd);
309 if (idx_map == MAP_FAILED)
310 return -1;
311
312 index = idx_map;
313
314 /* check index map */
315 if (idx_size < 4*256 + 20)
316 return error("index file too small");
317 nr = 0;
318 for (i = 0; i < 256; i++) {
319 unsigned int n = ntohl(index[i]);
320 if (n < nr)
321 return error("non-monotonic index");
322 nr = n;
323 }
324
325 /*
326 * Total size:
327 * - 256 index entries 4 bytes each
328 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
329 * - 20-byte SHA1 of the packfile
330 * - 20-byte SHA1 file checksum
331 */
332 if (idx_size != 4*256 + nr * 24 + 20 + 20)
333 return error("wrong index file size");
334
335 *idx_map_ = idx_map;
336 *idx_size_ = idx_size;
337 return 0;
338 }
339
340 static void unuse_one_packed_git(void)
341 {
342 /* NOTYET */
343 }
344
345 static int use_packed_git(struct packed_git *p)
346 {
347 if (!p->pack_base) {
348 int fd;
349 struct stat st;
350 void *map;
351
352 pack_mapped += p->pack_size;
353 while (PACK_MAX_SZ < pack_mapped)
354 unuse_one_packed_git();
355 fd = open(p->pack_name, O_RDONLY);
356 if (fd < 0)
357 return -1;
358 if (fstat(fd, &st)) {
359 close(fd);
360 return -1;
361 }
362 if (st.st_size != p->pack_size)
363 return -1;
364 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
365 close(fd);
366 if (map == MAP_FAILED)
367 return -1;
368 p->pack_base = map;
369 }
370 p->pack_last_used = pack_used_ctr++;
371 return 0;
372 }
373
374 static struct packed_git *add_packed_git(char *path, int path_len)
375 {
376 struct stat st;
377 struct packed_git *p;
378 unsigned long idx_size;
379 void *idx_map;
380
381 if (check_packed_git_idx(path, &idx_size, &idx_map))
382 return NULL;
383
384 /* do we have a corresponding .pack file? */
385 strcpy(path + path_len - 4, ".pack");
386 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
387 munmap(idx_map, idx_size);
388 return NULL;
389 }
390 /* ok, it looks sane as far as we can check without
391 * actually mapping the pack file.
392 */
393 p = xmalloc(sizeof(*p) + path_len + 2);
394 strcpy(p->pack_name, path);
395 p->index_size = idx_size;
396 p->pack_size = st.st_size;
397 p->index_base = idx_map;
398 p->next = NULL;
399 p->pack_base = NULL;
400 p->pack_last_used = 0;
401 return p;
402 }
403
404 static void prepare_packed_git_one(char *objdir)
405 {
406 char path[PATH_MAX];
407 int len;
408 DIR *dir;
409 struct dirent *de;
410
411 sprintf(path, "%s/pack", objdir);
412 len = strlen(path);
413 dir = opendir(path);
414 if (!dir)
415 return;
416 path[len++] = '/';
417 while ((de = readdir(dir)) != NULL) {
418 int namelen = strlen(de->d_name);
419 struct packed_git *p;
420
421 if (strcmp(de->d_name + namelen - 4, ".idx"))
422 continue;
423
424 /* we have .idx. Is it a file we can map? */
425 strcpy(path + len, de->d_name);
426 p = add_packed_git(path, len + namelen);
427 if (!p)
428 continue;
429 p->next = packed_git;
430 packed_git = p;
431 }
432 }
433
434 static void prepare_packed_git(void)
435 {
436 int i;
437 static int run_once = 0;
438
439 if (run_once++)
440 return;
441
442 prepare_packed_git_one(get_object_directory());
443 if (!alt_odb)
444 prepare_alt_odb();
445 for (i = 0; alt_odb[i].base != NULL; i++) {
446 alt_odb[i].name[0] = 0;
447 prepare_packed_git_one(alt_odb[i].base);
448 }
449 }
450
451 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
452 {
453 char header[100];
454 unsigned char real_sha1[20];
455 SHA_CTX c;
456
457 SHA1_Init(&c);
458 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
459 SHA1_Update(&c, map, size);
460 SHA1_Final(real_sha1, &c);
461 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
462 }
463
464 static void *map_sha1_file_internal(const unsigned char *sha1,
465 unsigned long *size,
466 int say_error)
467 {
468 struct stat st;
469 void *map;
470 int fd;
471 char *filename = find_sha1_file(sha1, &st);
472
473 if (!filename) {
474 if (say_error)
475 error("cannot map sha1 file %s", sha1_to_hex(sha1));
476 return NULL;
477 }
478
479 fd = open(filename, O_RDONLY | sha1_file_open_flag);
480 if (fd < 0) {
481 /* See if it works without O_NOATIME */
482 switch (sha1_file_open_flag) {
483 default:
484 fd = open(filename, O_RDONLY);
485 if (fd >= 0)
486 break;
487 /* Fallthrough */
488 case 0:
489 if (say_error)
490 perror(filename);
491 return NULL;
492 }
493
494 /* If it failed once, it will probably fail again.
495 * Stop using O_NOATIME
496 */
497 sha1_file_open_flag = 0;
498 }
499 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
500 close(fd);
501 if (-1 == (int)(long)map)
502 return NULL;
503 *size = st.st_size;
504 return map;
505 }
506
507 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
508 {
509 return map_sha1_file_internal(sha1, size, 1);
510 }
511
512 int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
513 {
514 /* Get the data stream */
515 memset(stream, 0, sizeof(*stream));
516 stream->next_in = map;
517 stream->avail_in = mapsize;
518 stream->next_out = buffer;
519 stream->avail_out = size;
520
521 inflateInit(stream);
522 return inflate(stream, 0);
523 }
524
525 void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
526 {
527 int bytes = strlen(buffer) + 1;
528 unsigned char *buf = xmalloc(1+size);
529
530 memcpy(buf, buffer + bytes, stream->total_out - bytes);
531 bytes = stream->total_out - bytes;
532 if (bytes < size) {
533 stream->next_out = buf + bytes;
534 stream->avail_out = size - bytes;
535 while (inflate(stream, Z_FINISH) == Z_OK)
536 /* nothing */;
537 }
538 buf[size] = 0;
539 inflateEnd(stream);
540 return buf;
541 }
542
543 /*
544 * We used to just use "sscanf()", but that's actually way
545 * too permissive for what we want to check. So do an anal
546 * object header parse by hand.
547 */
548 int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
549 {
550 int i;
551 unsigned long size;
552
553 /*
554 * The type can be at most ten bytes (including the
555 * terminating '\0' that we add), and is followed by
556 * a space.
557 */
558 i = 10;
559 for (;;) {
560 char c = *hdr++;
561 if (c == ' ')
562 break;
563 if (!--i)
564 return -1;
565 *type++ = c;
566 }
567 *type = 0;
568
569 /*
570 * The length must follow immediately, and be in canonical
571 * decimal format (ie "010" is not valid).
572 */
573 size = *hdr++ - '0';
574 if (size > 9)
575 return -1;
576 if (size) {
577 for (;;) {
578 unsigned long c = *hdr - '0';
579 if (c > 9)
580 break;
581 hdr++;
582 size = size * 10 + c;
583 }
584 }
585 *sizep = size;
586
587 /*
588 * The length must be followed by a zero byte
589 */
590 return *hdr ? -1 : 0;
591 }
592
593 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
594 {
595 int ret;
596 z_stream stream;
597 char hdr[8192];
598
599 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
600 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
601 return NULL;
602
603 return unpack_sha1_rest(&stream, hdr, *size);
604 }
605
606 static int packed_delta_info(unsigned char *base_sha1,
607 unsigned long delta_size,
608 unsigned long left,
609 char *type,
610 unsigned long *sizep)
611 {
612 unsigned char *data;
613 unsigned char delta_head[64];
614 int i;
615 unsigned char cmd;
616 unsigned long data_size, result_size, base_size, verify_base_size;
617 z_stream stream;
618 int st;
619
620 if (left < 20)
621 die("truncated pack file");
622 if (sha1_object_info(base_sha1, type, &base_size))
623 die("cannot get info for delta-pack base");
624
625 data = base_sha1 + 20;
626 data_size = left - 20;
627
628 memset(&stream, 0, sizeof(stream));
629
630 stream.next_in = data;
631 stream.avail_in = data_size;
632 stream.next_out = delta_head;
633 stream.avail_out = sizeof(delta_head);
634
635 inflateInit(&stream);
636 st = inflate(&stream, Z_FINISH);
637 inflateEnd(&stream);
638 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
639 die("delta data unpack-initial failed");
640
641 /* Examine the initial part of the delta to figure out
642 * the result size. Verify the base size while we are at it.
643 */
644 data = delta_head;
645 verify_base_size = i = 0;
646 cmd = *data++;
647 while (cmd) {
648 if (cmd & 1)
649 verify_base_size |= *data++ << i;
650 i += 8;
651 cmd >>= 1;
652 }
653
654 /* Read the result size */
655 result_size = i = 0;
656 cmd = *data++;
657 while (cmd) {
658 if (cmd & 1)
659 result_size |= *data++ << i;
660 i += 8;
661 cmd >>= 1;
662 }
663 if (verify_base_size != base_size)
664 die("delta base size mismatch");
665
666 *sizep = result_size;
667 return 0;
668 }
669
670 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
671 enum object_type *type, unsigned long *sizep)
672 {
673 unsigned char *pack, c;
674 unsigned long size;
675
676 if (offset >= p->pack_size)
677 die("object offset outside of pack file");
678
679 pack = p->pack_base + offset;
680 c = *pack++;
681 offset++;
682 *type = (c >> 4) & 7;
683 size = c & 15;
684 while (c & 0x80) {
685 if (offset >= p->pack_size)
686 die("object offset outside of pack file");
687 c = *pack++;
688 offset++;
689 size = (size << 7) | (c & 0x7f);
690 }
691 *sizep = size;
692 return offset;
693 }
694
695 static int packed_object_info(struct pack_entry *entry,
696 char *type, unsigned long *sizep)
697 {
698 struct packed_git *p = entry->p;
699 unsigned long offset, size, left;
700 unsigned char *pack;
701 enum object_type kind;
702
703 if (use_packed_git(p))
704 die("cannot map packed file");
705
706 offset = unpack_object_header(p, entry->offset, &kind, &size);
707 pack = p->pack_base + offset;
708 left = p->pack_size - offset;
709
710 switch (kind) {
711 case OBJ_DELTA:
712 return packed_delta_info(pack, size, left, type, sizep);
713 break;
714 case OBJ_COMMIT:
715 strcpy(type, "commit");
716 break;
717 case OBJ_TREE:
718 strcpy(type, "tree");
719 break;
720 case OBJ_BLOB:
721 strcpy(type, "blob");
722 break;
723 case OBJ_TAG:
724 strcpy(type, "tag");
725 break;
726 default:
727 die("corrupted pack file");
728 }
729 *sizep = size;
730 return 0;
731 }
732
733 /* forward declaration for a mutually recursive function */
734 static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
735
736 static void *unpack_delta_entry(unsigned char *base_sha1,
737 unsigned long delta_size,
738 unsigned long left,
739 char *type,
740 unsigned long *sizep)
741 {
742 void *data, *delta_data, *result, *base;
743 unsigned long data_size, result_size, base_size;
744 z_stream stream;
745 int st;
746
747 if (left < 20)
748 die("truncated pack file");
749 data = base_sha1 + 20;
750 data_size = left - 20;
751 delta_data = xmalloc(delta_size);
752
753 memset(&stream, 0, sizeof(stream));
754
755 stream.next_in = data;
756 stream.avail_in = data_size;
757 stream.next_out = delta_data;
758 stream.avail_out = delta_size;
759
760 inflateInit(&stream);
761 st = inflate(&stream, Z_FINISH);
762 inflateEnd(&stream);
763 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
764 die("delta data unpack failed");
765
766 /* This may recursively unpack the base, which is what we want */
767 base = read_sha1_file(base_sha1, type, &base_size);
768 if (!base)
769 die("failed to read delta-pack base object %s",
770 sha1_to_hex(base_sha1));
771 result = patch_delta(base, base_size,
772 delta_data, delta_size,
773 &result_size);
774 if (!result)
775 die("failed to apply delta");
776 free(delta_data);
777 free(base);
778 *sizep = result_size;
779 return result;
780 }
781
782 static void *unpack_non_delta_entry(unsigned char *data,
783 unsigned long size,
784 unsigned long left)
785 {
786 int st;
787 z_stream stream;
788 char *buffer;
789
790 buffer = xmalloc(size + 1);
791 buffer[size] = 0;
792 memset(&stream, 0, sizeof(stream));
793 stream.next_in = data;
794 stream.avail_in = left;
795 stream.next_out = buffer;
796 stream.avail_out = size;
797
798 inflateInit(&stream);
799 st = inflate(&stream, Z_FINISH);
800 inflateEnd(&stream);
801 if ((st != Z_STREAM_END) || stream.total_out != size) {
802 free(buffer);
803 return NULL;
804 }
805
806 return buffer;
807 }
808
809 static void *unpack_entry(struct pack_entry *entry,
810 char *type, unsigned long *sizep)
811 {
812 struct packed_git *p = entry->p;
813 unsigned long offset, size, left;
814 unsigned char *pack;
815 enum object_type kind;
816
817 if (use_packed_git(p))
818 die("cannot map packed file");
819
820 offset = unpack_object_header(p, entry->offset, &kind, &size);
821 pack = p->pack_base + offset;
822 left = p->pack_size - offset;
823 switch (kind) {
824 case OBJ_DELTA:
825 return unpack_delta_entry(pack, size, left, type, sizep);
826 case OBJ_COMMIT:
827 strcpy(type, "commit");
828 break;
829 case OBJ_TREE:
830 strcpy(type, "tree");
831 break;
832 case OBJ_BLOB:
833 strcpy(type, "blob");
834 break;
835 case OBJ_TAG:
836 strcpy(type, "tag");
837 break;
838 default:
839 die("corrupted pack file");
840 }
841 *sizep = size;
842 return unpack_non_delta_entry(pack, size, left);
843 }
844
845 static int find_pack_entry_1(const unsigned char *sha1,
846 struct pack_entry *e, struct packed_git *p)
847 {
848 int *level1_ofs = p->index_base;
849 int hi = ntohl(level1_ofs[*sha1]);
850 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
851 void *index = p->index_base + 256;
852
853 do {
854 int mi = (lo + hi) / 2;
855 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
856 if (!cmp) {
857 e->offset = ntohl(*((int*)(index + 24 * mi)));
858 memcpy(e->sha1, sha1, 20);
859 e->p = p;
860 return 1;
861 }
862 if (cmp > 0)
863 hi = mi;
864 else
865 lo = mi+1;
866 } while (lo < hi);
867 return 0;
868 }
869
870 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
871 {
872 struct packed_git *p;
873 prepare_packed_git();
874
875 for (p = packed_git; p; p = p->next) {
876 if (find_pack_entry_1(sha1, e, p))
877 return 1;
878 }
879 return 0;
880 }
881
882 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
883 {
884 int status;
885 unsigned long mapsize, size;
886 void *map;
887 z_stream stream;
888 char hdr[128];
889
890 map = map_sha1_file_internal(sha1, &mapsize, 0);
891 if (!map) {
892 struct pack_entry e;
893
894 if (!find_pack_entry(sha1, &e))
895 return error("unable to find %s", sha1_to_hex(sha1));
896 if (!packed_object_info(&e, type, sizep))
897 return 0;
898 /* sheesh */
899 map = unpack_entry(&e, type, sizep);
900 free(map);
901 return (map == NULL) ? 0 : -1;
902 }
903 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
904 status = error("unable to unpack %s header",
905 sha1_to_hex(sha1));
906 if (parse_sha1_header(hdr, type, &size) < 0)
907 status = error("unable to parse %s header", sha1_to_hex(sha1));
908 else {
909 status = 0;
910 *sizep = size;
911 }
912 inflateEnd(&stream);
913 munmap(map, mapsize);
914 return status;
915 }
916
917 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
918 {
919 struct pack_entry e;
920
921 if (!find_pack_entry(sha1, &e)) {
922 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
923 return NULL;
924 }
925 return unpack_entry(&e, type, size);
926 }
927
928 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
929 {
930 unsigned long mapsize;
931 void *map, *buf;
932
933 map = map_sha1_file_internal(sha1, &mapsize, 0);
934 if (map) {
935 buf = unpack_sha1_file(map, mapsize, type, size);
936 munmap(map, mapsize);
937 return buf;
938 }
939 return read_packed_sha1(sha1, type, size);
940 }
941
942 void *read_object_with_reference(const unsigned char *sha1,
943 const char *required_type,
944 unsigned long *size,
945 unsigned char *actual_sha1_return)
946 {
947 char type[20];
948 void *buffer;
949 unsigned long isize;
950 unsigned char actual_sha1[20];
951
952 memcpy(actual_sha1, sha1, 20);
953 while (1) {
954 int ref_length = -1;
955 const char *ref_type = NULL;
956
957 buffer = read_sha1_file(actual_sha1, type, &isize);
958 if (!buffer)
959 return NULL;
960 if (!strcmp(type, required_type)) {
961 *size = isize;
962 if (actual_sha1_return)
963 memcpy(actual_sha1_return, actual_sha1, 20);
964 return buffer;
965 }
966 /* Handle references */
967 else if (!strcmp(type, "commit"))
968 ref_type = "tree ";
969 else if (!strcmp(type, "tag"))
970 ref_type = "object ";
971 else {
972 free(buffer);
973 return NULL;
974 }
975 ref_length = strlen(ref_type);
976
977 if (memcmp(buffer, ref_type, ref_length) ||
978 get_sha1_hex(buffer + ref_length, actual_sha1)) {
979 free(buffer);
980 return NULL;
981 }
982 /* Now we have the ID of the referred-to object in
983 * actual_sha1. Check again. */
984 }
985 }
986
987 static char *write_sha1_file_prepare(void *buf,
988 unsigned long len,
989 const char *type,
990 unsigned char *sha1,
991 unsigned char *hdr,
992 int *hdrlen)
993 {
994 SHA_CTX c;
995
996 /* Generate the header */
997 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
998
999 /* Sha1.. */
1000 SHA1_Init(&c);
1001 SHA1_Update(&c, hdr, *hdrlen);
1002 SHA1_Update(&c, buf, len);
1003 SHA1_Final(sha1, &c);
1004
1005 return sha1_file_name(sha1);
1006 }
1007
1008 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1009 {
1010 int size;
1011 unsigned char *compressed;
1012 z_stream stream;
1013 unsigned char sha1[20];
1014 char *filename;
1015 static char tmpfile[PATH_MAX];
1016 unsigned char hdr[50];
1017 int fd, hdrlen, ret;
1018
1019 /* Normally if we have it in the pack then we do not bother writing
1020 * it out into .git/objects/??/?{38} file.
1021 */
1022 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1023 if (returnsha1)
1024 memcpy(returnsha1, sha1, 20);
1025 if (has_sha1_file(sha1))
1026 return 0;
1027 fd = open(filename, O_RDONLY);
1028 if (fd >= 0) {
1029 /*
1030 * FIXME!!! We might do collision checking here, but we'd
1031 * need to uncompress the old file and check it. Later.
1032 */
1033 close(fd);
1034 return 0;
1035 }
1036
1037 if (errno != ENOENT) {
1038 fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
1039 return -1;
1040 }
1041
1042 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1043
1044 fd = mkstemp(tmpfile);
1045 if (fd < 0) {
1046 fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
1047 return -1;
1048 }
1049
1050 /* Set it up */
1051 memset(&stream, 0, sizeof(stream));
1052 deflateInit(&stream, Z_BEST_COMPRESSION);
1053 size = deflateBound(&stream, len+hdrlen);
1054 compressed = xmalloc(size);
1055
1056 /* Compress it */
1057 stream.next_out = compressed;
1058 stream.avail_out = size;
1059
1060 /* First header.. */
1061 stream.next_in = hdr;
1062 stream.avail_in = hdrlen;
1063 while (deflate(&stream, 0) == Z_OK)
1064 /* nothing */;
1065
1066 /* Then the data itself.. */
1067 stream.next_in = buf;
1068 stream.avail_in = len;
1069 while (deflate(&stream, Z_FINISH) == Z_OK)
1070 /* nothing */;
1071 deflateEnd(&stream);
1072 size = stream.total_out;
1073
1074 if (write(fd, compressed, size) != size)
1075 die("unable to write file");
1076 fchmod(fd, 0444);
1077 close(fd);
1078 free(compressed);
1079
1080 ret = link(tmpfile, filename);
1081 if (ret < 0) {
1082 ret = errno;
1083
1084 /*
1085 * Coda hack - coda doesn't like cross-directory links,
1086 * so we fall back to a rename, which will mean that it
1087 * won't be able to check collisions, but that's not a
1088 * big deal.
1089 *
1090 * When this succeeds, we just return 0. We have nothing
1091 * left to unlink.
1092 */
1093 if (ret == EXDEV && !rename(tmpfile, filename))
1094 return 0;
1095 }
1096 unlink(tmpfile);
1097 if (ret) {
1098 if (ret != EEXIST) {
1099 fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
1100 return -1;
1101 }
1102 /* FIXME!!! Collision check here ? */
1103 }
1104
1105 return 0;
1106 }
1107
1108 int write_sha1_from_fd(const unsigned char *sha1, int fd)
1109 {
1110 char *filename = sha1_file_name(sha1);
1111
1112 int local;
1113 z_stream stream;
1114 unsigned char real_sha1[20];
1115 unsigned char buf[4096];
1116 unsigned char discard[4096];
1117 int ret;
1118 SHA_CTX c;
1119
1120 local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
1121
1122 if (local < 0)
1123 return error("Couldn't open %s\n", filename);
1124
1125 memset(&stream, 0, sizeof(stream));
1126
1127 inflateInit(&stream);
1128
1129 SHA1_Init(&c);
1130
1131 do {
1132 ssize_t size;
1133 size = read(fd, buf, 4096);
1134 if (size <= 0) {
1135 close(local);
1136 unlink(filename);
1137 if (!size)
1138 return error("Connection closed?");
1139 perror("Reading from connection");
1140 return -1;
1141 }
1142 write(local, buf, size);
1143 stream.avail_in = size;
1144 stream.next_in = buf;
1145 do {
1146 stream.next_out = discard;
1147 stream.avail_out = sizeof(discard);
1148 ret = inflate(&stream, Z_SYNC_FLUSH);
1149 SHA1_Update(&c, discard, sizeof(discard) -
1150 stream.avail_out);
1151 } while (stream.avail_in && ret == Z_OK);
1152
1153 } while (ret == Z_OK);
1154 inflateEnd(&stream);
1155
1156 close(local);
1157 SHA1_Final(real_sha1, &c);
1158 if (ret != Z_STREAM_END) {
1159 unlink(filename);
1160 return error("File %s corrupted", sha1_to_hex(sha1));
1161 }
1162 if (memcmp(sha1, real_sha1, 20)) {
1163 unlink(filename);
1164 return error("File %s has bad hash\n", sha1_to_hex(sha1));
1165 }
1166
1167 return 0;
1168 }
1169
1170 int has_sha1_file(const unsigned char *sha1)
1171 {
1172 struct stat st;
1173 struct pack_entry e;
1174
1175 if (find_sha1_file(sha1, &st))
1176 return 1;
1177 return find_pack_entry(sha1, &e);
1178 }
1179
1180 int index_fd(unsigned char *sha1, int fd, struct stat *st)
1181 {
1182 unsigned long size = st->st_size;
1183 void *buf;
1184 int ret;
1185
1186 buf = "";
1187 if (size)
1188 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1189 close(fd);
1190 if ((int)(long)buf == -1)
1191 return -1;
1192
1193 ret = write_sha1_file(buf, size, "blob", sha1);
1194 if (size)
1195 munmap(buf, size);
1196 return ret;
1197 }