Merge branch 'master' into lj/refs
[git/git.git] / sha1_file.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
9 #include "cache.h"
10 #include "delta.h"
11 #include "pack.h"
12 #include "blob.h"
13 #include "commit.h"
14 #include "tag.h"
15 #include "tree.h"
16
17 #ifndef O_NOATIME
18 #if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
19 #define O_NOATIME 01000000
20 #else
21 #define O_NOATIME 0
22 #endif
23 #endif
24
25 const unsigned char null_sha1[20];
26
27 static unsigned int sha1_file_open_flag = O_NOATIME;
28
29 signed char hexval_table[256] = {
30 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
31 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
32 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
33 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
34 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
35 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
36 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
37 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
38 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
42 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
45 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
46 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
47 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
51 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
62 };
63
64 int get_sha1_hex(const char *hex, unsigned char *sha1)
65 {
66 int i;
67 for (i = 0; i < 20; i++) {
68 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
69 if (val & ~0xff)
70 return -1;
71 *sha1++ = val;
72 hex += 2;
73 }
74 return 0;
75 }
76
77 int safe_create_leading_directories(char *path)
78 {
79 char *pos = path;
80 struct stat st;
81
82 if (*pos == '/')
83 pos++;
84
85 while (pos) {
86 pos = strchr(pos, '/');
87 if (!pos)
88 break;
89 *pos = 0;
90 if (!stat(path, &st)) {
91 /* path exists */
92 if (!S_ISDIR(st.st_mode)) {
93 *pos = '/';
94 return -3;
95 }
96 }
97 else if (mkdir(path, 0777)) {
98 *pos = '/';
99 return -1;
100 }
101 else if (adjust_shared_perm(path)) {
102 *pos = '/';
103 return -2;
104 }
105 *pos++ = '/';
106 }
107 return 0;
108 }
109
110 char * sha1_to_hex(const unsigned char *sha1)
111 {
112 static int bufno;
113 static char hexbuffer[4][50];
114 static const char hex[] = "0123456789abcdef";
115 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
116 int i;
117
118 for (i = 0; i < 20; i++) {
119 unsigned int val = *sha1++;
120 *buf++ = hex[val >> 4];
121 *buf++ = hex[val & 0xf];
122 }
123 *buf = '\0';
124
125 return buffer;
126 }
127
128 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
129 {
130 int i;
131 for (i = 0; i < 20; i++) {
132 static char hex[] = "0123456789abcdef";
133 unsigned int val = sha1[i];
134 char *pos = pathbuf + i*2 + (i > 0);
135 *pos++ = hex[val >> 4];
136 *pos = hex[val & 0xf];
137 }
138 }
139
140 /*
141 * NOTE! This returns a statically allocated buffer, so you have to be
142 * careful about using it. Do a "xstrdup()" if you need to save the
143 * filename.
144 *
145 * Also note that this returns the location for creating. Reading
146 * SHA1 file can happen from any alternate directory listed in the
147 * DB_ENVIRONMENT environment variable if it is not found in
148 * the primary object database.
149 */
150 char *sha1_file_name(const unsigned char *sha1)
151 {
152 static char *name, *base;
153
154 if (!base) {
155 const char *sha1_file_directory = get_object_directory();
156 int len = strlen(sha1_file_directory);
157 base = xmalloc(len + 60);
158 memcpy(base, sha1_file_directory, len);
159 memset(base+len, 0, 60);
160 base[len] = '/';
161 base[len+3] = '/';
162 name = base + len + 1;
163 }
164 fill_sha1_path(name, sha1);
165 return base;
166 }
167
168 char *sha1_pack_name(const unsigned char *sha1)
169 {
170 static const char hex[] = "0123456789abcdef";
171 static char *name, *base, *buf;
172 int i;
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 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
179 name = base + len + 11;
180 }
181
182 buf = name;
183
184 for (i = 0; i < 20; i++) {
185 unsigned int val = *sha1++;
186 *buf++ = hex[val >> 4];
187 *buf++ = hex[val & 0xf];
188 }
189
190 return base;
191 }
192
193 char *sha1_pack_index_name(const unsigned char *sha1)
194 {
195 static const char hex[] = "0123456789abcdef";
196 static char *name, *base, *buf;
197 int i;
198
199 if (!base) {
200 const char *sha1_file_directory = get_object_directory();
201 int len = strlen(sha1_file_directory);
202 base = xmalloc(len + 60);
203 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
204 name = base + len + 11;
205 }
206
207 buf = name;
208
209 for (i = 0; i < 20; i++) {
210 unsigned int val = *sha1++;
211 *buf++ = hex[val >> 4];
212 *buf++ = hex[val & 0xf];
213 }
214
215 return base;
216 }
217
218 struct alternate_object_database *alt_odb_list;
219 static struct alternate_object_database **alt_odb_tail;
220
221 static void read_info_alternates(const char * alternates, int depth);
222
223 /*
224 * Prepare alternate object database registry.
225 *
226 * The variable alt_odb_list points at the list of struct
227 * alternate_object_database. The elements on this list come from
228 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
229 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
230 * whose contents is similar to that environment variable but can be
231 * LF separated. Its base points at a statically allocated buffer that
232 * contains "/the/directory/corresponding/to/.git/objects/...", while
233 * its name points just after the slash at the end of ".git/objects/"
234 * in the example above, and has enough space to hold 40-byte hex
235 * SHA1, an extra slash for the first level indirection, and the
236 * terminating NUL.
237 */
238 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
239 {
240 struct stat st;
241 const char *objdir = get_object_directory();
242 struct alternate_object_database *ent;
243 struct alternate_object_database *alt;
244 /* 43 = 40-byte + 2 '/' + terminating NUL */
245 int pfxlen = len;
246 int entlen = pfxlen + 43;
247 int base_len = -1;
248
249 if (*entry != '/' && relative_base) {
250 /* Relative alt-odb */
251 if (base_len < 0)
252 base_len = strlen(relative_base) + 1;
253 entlen += base_len;
254 pfxlen += base_len;
255 }
256 ent = xmalloc(sizeof(*ent) + entlen);
257
258 if (*entry != '/' && relative_base) {
259 memcpy(ent->base, relative_base, base_len - 1);
260 ent->base[base_len - 1] = '/';
261 memcpy(ent->base + base_len, entry, len);
262 }
263 else
264 memcpy(ent->base, entry, pfxlen);
265
266 ent->name = ent->base + pfxlen + 1;
267 ent->base[pfxlen + 3] = '/';
268 ent->base[pfxlen] = ent->base[entlen-1] = 0;
269
270 /* Detect cases where alternate disappeared */
271 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
272 error("object directory %s does not exist; "
273 "check .git/objects/info/alternates.",
274 ent->base);
275 free(ent);
276 return -1;
277 }
278
279 /* Prevent the common mistake of listing the same
280 * thing twice, or object directory itself.
281 */
282 for (alt = alt_odb_list; alt; alt = alt->next) {
283 if (!memcmp(ent->base, alt->base, pfxlen)) {
284 free(ent);
285 return -1;
286 }
287 }
288 if (!memcmp(ent->base, objdir, pfxlen)) {
289 free(ent);
290 return -1;
291 }
292
293 /* add the alternate entry */
294 *alt_odb_tail = ent;
295 alt_odb_tail = &(ent->next);
296 ent->next = NULL;
297
298 /* recursively add alternates */
299 read_info_alternates(ent->base, depth + 1);
300
301 ent->base[pfxlen] = '/';
302
303 return 0;
304 }
305
306 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
307 const char *relative_base, int depth)
308 {
309 const char *cp, *last;
310
311 if (depth > 5) {
312 error("%s: ignoring alternate object stores, nesting too deep.",
313 relative_base);
314 return;
315 }
316
317 last = alt;
318 while (last < ep) {
319 cp = last;
320 if (cp < ep && *cp == '#') {
321 while (cp < ep && *cp != sep)
322 cp++;
323 last = cp + 1;
324 continue;
325 }
326 while (cp < ep && *cp != sep)
327 cp++;
328 if (last != cp) {
329 if ((*last != '/') && depth) {
330 error("%s: ignoring relative alternate object store %s",
331 relative_base, last);
332 } else {
333 link_alt_odb_entry(last, cp - last,
334 relative_base, depth);
335 }
336 }
337 while (cp < ep && *cp == sep)
338 cp++;
339 last = cp;
340 }
341 }
342
343 static void read_info_alternates(const char * relative_base, int depth)
344 {
345 char *map;
346 struct stat st;
347 char path[PATH_MAX];
348 int fd;
349
350 sprintf(path, "%s/info/alternates", relative_base);
351 fd = open(path, O_RDONLY);
352 if (fd < 0)
353 return;
354 if (fstat(fd, &st) || (st.st_size == 0)) {
355 close(fd);
356 return;
357 }
358 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
359 close(fd);
360 if (map == MAP_FAILED)
361 return;
362
363 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
364
365 munmap(map, st.st_size);
366 }
367
368 void prepare_alt_odb(void)
369 {
370 const char *alt;
371
372 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
373 if (!alt) alt = "";
374
375 if (alt_odb_tail)
376 return;
377 alt_odb_tail = &alt_odb_list;
378 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
379
380 read_info_alternates(get_object_directory(), 0);
381 }
382
383 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
384 {
385 char *name = sha1_file_name(sha1);
386 struct alternate_object_database *alt;
387
388 if (!stat(name, st))
389 return name;
390 prepare_alt_odb();
391 for (alt = alt_odb_list; alt; alt = alt->next) {
392 name = alt->name;
393 fill_sha1_path(name, sha1);
394 if (!stat(alt->base, st))
395 return alt->base;
396 }
397 return NULL;
398 }
399
400 #define PACK_MAX_SZ (1<<26)
401 static int pack_used_ctr;
402 static unsigned long pack_mapped;
403 struct packed_git *packed_git;
404
405 static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
406 void **idx_map_)
407 {
408 void *idx_map;
409 unsigned int *index;
410 unsigned long idx_size;
411 int nr, i;
412 int fd = open(path, O_RDONLY);
413 struct stat st;
414 if (fd < 0)
415 return -1;
416 if (fstat(fd, &st)) {
417 close(fd);
418 return -1;
419 }
420 idx_size = st.st_size;
421 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
422 close(fd);
423 if (idx_map == MAP_FAILED)
424 return -1;
425
426 index = idx_map;
427 *idx_map_ = idx_map;
428 *idx_size_ = idx_size;
429
430 /* check index map */
431 if (idx_size < 4*256 + 20 + 20)
432 return error("index file too small");
433 nr = 0;
434 for (i = 0; i < 256; i++) {
435 unsigned int n = ntohl(index[i]);
436 if (n < nr)
437 return error("non-monotonic index");
438 nr = n;
439 }
440
441 /*
442 * Total size:
443 * - 256 index entries 4 bytes each
444 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
445 * - 20-byte SHA1 of the packfile
446 * - 20-byte SHA1 file checksum
447 */
448 if (idx_size != 4*256 + nr * 24 + 20 + 20)
449 return error("wrong index file size");
450
451 return 0;
452 }
453
454 static int unuse_one_packed_git(void)
455 {
456 struct packed_git *p, *lru = NULL;
457
458 for (p = packed_git; p; p = p->next) {
459 if (p->pack_use_cnt || !p->pack_base)
460 continue;
461 if (!lru || p->pack_last_used < lru->pack_last_used)
462 lru = p;
463 }
464 if (!lru)
465 return 0;
466 munmap(lru->pack_base, lru->pack_size);
467 lru->pack_base = NULL;
468 return 1;
469 }
470
471 void unuse_packed_git(struct packed_git *p)
472 {
473 p->pack_use_cnt--;
474 }
475
476 int use_packed_git(struct packed_git *p)
477 {
478 if (!p->pack_size) {
479 struct stat st;
480 /* We created the struct before we had the pack */
481 stat(p->pack_name, &st);
482 if (!S_ISREG(st.st_mode))
483 die("packfile %s not a regular file", p->pack_name);
484 p->pack_size = st.st_size;
485 }
486 if (!p->pack_base) {
487 int fd;
488 struct stat st;
489 void *map;
490 struct pack_header *hdr;
491
492 pack_mapped += p->pack_size;
493 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
494 ; /* nothing */
495 fd = open(p->pack_name, O_RDONLY);
496 if (fd < 0)
497 die("packfile %s cannot be opened", p->pack_name);
498 if (fstat(fd, &st)) {
499 close(fd);
500 die("packfile %s cannot be opened", p->pack_name);
501 }
502 if (st.st_size != p->pack_size)
503 die("packfile %s size mismatch.", p->pack_name);
504 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
505 close(fd);
506 if (map == MAP_FAILED)
507 die("packfile %s cannot be mapped.", p->pack_name);
508 p->pack_base = map;
509
510 /* Check if we understand this pack file. If we don't we're
511 * likely too old to handle it.
512 */
513 hdr = map;
514 if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
515 die("packfile %s isn't actually a pack.", p->pack_name);
516 if (!pack_version_ok(hdr->hdr_version))
517 die("packfile %s is version %i and not supported"
518 " (try upgrading GIT to a newer version)",
519 p->pack_name, ntohl(hdr->hdr_version));
520
521 /* Check if the pack file matches with the index file.
522 * this is cheap.
523 */
524 if (hashcmp((unsigned char *)(p->index_base) +
525 p->index_size - 40,
526 (unsigned char *)p->pack_base +
527 p->pack_size - 20)) {
528 die("packfile %s does not match index.", p->pack_name);
529 }
530 }
531 p->pack_last_used = pack_used_ctr++;
532 p->pack_use_cnt++;
533 return 0;
534 }
535
536 struct packed_git *add_packed_git(char *path, int path_len, int local)
537 {
538 struct stat st;
539 struct packed_git *p;
540 unsigned long idx_size;
541 void *idx_map;
542 unsigned char sha1[20];
543
544 if (check_packed_git_idx(path, &idx_size, &idx_map))
545 return NULL;
546
547 /* do we have a corresponding .pack file? */
548 strcpy(path + path_len - 4, ".pack");
549 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
550 munmap(idx_map, idx_size);
551 return NULL;
552 }
553 /* ok, it looks sane as far as we can check without
554 * actually mapping the pack file.
555 */
556 p = xmalloc(sizeof(*p) + path_len + 2);
557 strcpy(p->pack_name, path);
558 p->index_size = idx_size;
559 p->pack_size = st.st_size;
560 p->index_base = idx_map;
561 p->next = NULL;
562 p->pack_base = NULL;
563 p->pack_last_used = 0;
564 p->pack_use_cnt = 0;
565 p->pack_local = local;
566 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
567 hashcpy(p->sha1, sha1);
568 return p;
569 }
570
571 struct packed_git *parse_pack_index(unsigned char *sha1)
572 {
573 char *path = sha1_pack_index_name(sha1);
574 return parse_pack_index_file(sha1, path);
575 }
576
577 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
578 {
579 struct packed_git *p;
580 unsigned long idx_size;
581 void *idx_map;
582 char *path;
583
584 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
585 return NULL;
586
587 path = sha1_pack_name(sha1);
588
589 p = xmalloc(sizeof(*p) + strlen(path) + 2);
590 strcpy(p->pack_name, path);
591 p->index_size = idx_size;
592 p->pack_size = 0;
593 p->index_base = idx_map;
594 p->next = NULL;
595 p->pack_base = NULL;
596 p->pack_last_used = 0;
597 p->pack_use_cnt = 0;
598 hashcpy(p->sha1, sha1);
599 return p;
600 }
601
602 void install_packed_git(struct packed_git *pack)
603 {
604 pack->next = packed_git;
605 packed_git = pack;
606 }
607
608 static void prepare_packed_git_one(char *objdir, int local)
609 {
610 char path[PATH_MAX];
611 int len;
612 DIR *dir;
613 struct dirent *de;
614
615 sprintf(path, "%s/pack", objdir);
616 len = strlen(path);
617 dir = opendir(path);
618 if (!dir) {
619 if (errno != ENOENT)
620 error("unable to open object pack directory: %s: %s",
621 path, strerror(errno));
622 return;
623 }
624 path[len++] = '/';
625 while ((de = readdir(dir)) != NULL) {
626 int namelen = strlen(de->d_name);
627 struct packed_git *p;
628
629 if (!has_extension(de->d_name, ".idx"))
630 continue;
631
632 /* we have .idx. Is it a file we can map? */
633 strcpy(path + len, de->d_name);
634 for (p = packed_git; p; p = p->next) {
635 if (!memcmp(path, p->pack_name, len + namelen - 4))
636 break;
637 }
638 if (p)
639 continue;
640 p = add_packed_git(path, len + namelen, local);
641 if (!p)
642 continue;
643 p->next = packed_git;
644 packed_git = p;
645 }
646 closedir(dir);
647 }
648
649 static int prepare_packed_git_run_once = 0;
650 void prepare_packed_git(void)
651 {
652 struct alternate_object_database *alt;
653
654 if (prepare_packed_git_run_once)
655 return;
656 prepare_packed_git_one(get_object_directory(), 1);
657 prepare_alt_odb();
658 for (alt = alt_odb_list; alt; alt = alt->next) {
659 alt->name[-1] = 0;
660 prepare_packed_git_one(alt->base, 0);
661 alt->name[-1] = '/';
662 }
663 prepare_packed_git_run_once = 1;
664 }
665
666 static void reprepare_packed_git(void)
667 {
668 prepare_packed_git_run_once = 0;
669 prepare_packed_git();
670 }
671
672 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
673 {
674 char header[100];
675 unsigned char real_sha1[20];
676 SHA_CTX c;
677
678 SHA1_Init(&c);
679 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
680 SHA1_Update(&c, map, size);
681 SHA1_Final(real_sha1, &c);
682 return hashcmp(sha1, real_sha1) ? -1 : 0;
683 }
684
685 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
686 {
687 struct stat st;
688 void *map;
689 int fd;
690 char *filename = find_sha1_file(sha1, &st);
691
692 if (!filename) {
693 return NULL;
694 }
695
696 fd = open(filename, O_RDONLY | sha1_file_open_flag);
697 if (fd < 0) {
698 /* See if it works without O_NOATIME */
699 switch (sha1_file_open_flag) {
700 default:
701 fd = open(filename, O_RDONLY);
702 if (fd >= 0)
703 break;
704 /* Fallthrough */
705 case 0:
706 return NULL;
707 }
708
709 /* If it failed once, it will probably fail again.
710 * Stop using O_NOATIME
711 */
712 sha1_file_open_flag = 0;
713 }
714 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
715 close(fd);
716 if (map == MAP_FAILED)
717 return NULL;
718 *size = st.st_size;
719 return map;
720 }
721
722 int legacy_loose_object(unsigned char *map)
723 {
724 unsigned int word;
725
726 /*
727 * Is it a zlib-compressed buffer? If so, the first byte
728 * must be 0x78 (15-bit window size, deflated), and the
729 * first 16-bit word is evenly divisible by 31
730 */
731 word = (map[0] << 8) + map[1];
732 if (map[0] == 0x78 && !(word % 31))
733 return 1;
734 else
735 return 0;
736 }
737
738 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
739 {
740 unsigned shift;
741 unsigned char c;
742 unsigned long size;
743 unsigned long used = 0;
744
745 c = buf[used++];
746 *type = (c >> 4) & 7;
747 size = c & 15;
748 shift = 4;
749 while (c & 0x80) {
750 if (len <= used)
751 return 0;
752 if (sizeof(long) * 8 <= shift)
753 return 0;
754 c = buf[used++];
755 size += (c & 0x7f) << shift;
756 shift += 7;
757 }
758 *sizep = size;
759 return used;
760 }
761
762 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
763 {
764 unsigned long size, used;
765 static const char valid_loose_object_type[8] = {
766 0, /* OBJ_EXT */
767 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
768 0, /* "delta" and others are invalid in a loose object */
769 };
770 enum object_type type;
771
772 /* Get the data stream */
773 memset(stream, 0, sizeof(*stream));
774 stream->next_in = map;
775 stream->avail_in = mapsize;
776 stream->next_out = buffer;
777 stream->avail_out = bufsiz;
778
779 if (legacy_loose_object(map)) {
780 inflateInit(stream);
781 return inflate(stream, 0);
782 }
783
784 used = unpack_object_header_gently(map, mapsize, &type, &size);
785 if (!used || !valid_loose_object_type[type])
786 return -1;
787 map += used;
788 mapsize -= used;
789
790 /* Set up the stream for the rest.. */
791 stream->next_in = map;
792 stream->avail_in = mapsize;
793 inflateInit(stream);
794
795 /* And generate the fake traditional header */
796 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
797 type_names[type], size);
798 return 0;
799 }
800
801 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
802 {
803 int bytes = strlen(buffer) + 1;
804 unsigned char *buf = xmalloc(1+size);
805 unsigned long n;
806
807 n = stream->total_out - bytes;
808 if (n > size)
809 n = size;
810 memcpy(buf, (char *) buffer + bytes, n);
811 bytes = n;
812 if (bytes < size) {
813 stream->next_out = buf + bytes;
814 stream->avail_out = size - bytes;
815 while (inflate(stream, Z_FINISH) == Z_OK)
816 /* nothing */;
817 }
818 buf[size] = 0;
819 inflateEnd(stream);
820 return buf;
821 }
822
823 /*
824 * We used to just use "sscanf()", but that's actually way
825 * too permissive for what we want to check. So do an anal
826 * object header parse by hand.
827 */
828 static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
829 {
830 int i;
831 unsigned long size;
832
833 /*
834 * The type can be at most ten bytes (including the
835 * terminating '\0' that we add), and is followed by
836 * a space.
837 */
838 i = 10;
839 for (;;) {
840 char c = *hdr++;
841 if (c == ' ')
842 break;
843 if (!--i)
844 return -1;
845 *type++ = c;
846 }
847 *type = 0;
848
849 /*
850 * The length must follow immediately, and be in canonical
851 * decimal format (ie "010" is not valid).
852 */
853 size = *hdr++ - '0';
854 if (size > 9)
855 return -1;
856 if (size) {
857 for (;;) {
858 unsigned long c = *hdr - '0';
859 if (c > 9)
860 break;
861 hdr++;
862 size = size * 10 + c;
863 }
864 }
865 *sizep = size;
866
867 /*
868 * The length must be followed by a zero byte
869 */
870 return *hdr ? -1 : 0;
871 }
872
873 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
874 {
875 int ret;
876 z_stream stream;
877 char hdr[8192];
878
879 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
880 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
881 return NULL;
882
883 return unpack_sha1_rest(&stream, hdr, *size);
884 }
885
886 /* forward declaration for a mutually recursive function */
887 static int packed_object_info(struct packed_git *p, unsigned long offset,
888 char *type, unsigned long *sizep);
889
890 static int packed_delta_info(struct packed_git *p,
891 unsigned long offset,
892 char *type,
893 unsigned long *sizep)
894 {
895 unsigned long base_offset;
896 unsigned char *base_sha1 = (unsigned char *) p->pack_base + offset;
897
898 if (p->pack_size < offset + 20)
899 die("truncated pack file");
900 /* The base entry _must_ be in the same pack */
901 base_offset = find_pack_entry_one(base_sha1, p);
902 if (!base_offset)
903 die("failed to find delta-pack base object %s",
904 sha1_to_hex(base_sha1));
905 offset += 20;
906
907 /* We choose to only get the type of the base object and
908 * ignore potentially corrupt pack file that expects the delta
909 * based on a base with a wrong size. This saves tons of
910 * inflate() calls.
911 */
912 if (packed_object_info(p, base_offset, type, NULL))
913 die("cannot get info for delta-pack base");
914
915 if (sizep) {
916 const unsigned char *data;
917 unsigned char delta_head[64];
918 unsigned long result_size;
919 z_stream stream;
920 int st;
921
922 memset(&stream, 0, sizeof(stream));
923
924 stream.next_in = (unsigned char *) p->pack_base + offset;
925 stream.avail_in = p->pack_size - offset;
926 stream.next_out = delta_head;
927 stream.avail_out = sizeof(delta_head);
928
929 inflateInit(&stream);
930 st = inflate(&stream, Z_FINISH);
931 inflateEnd(&stream);
932 if ((st != Z_STREAM_END) &&
933 stream.total_out != sizeof(delta_head))
934 die("delta data unpack-initial failed");
935
936 /* Examine the initial part of the delta to figure out
937 * the result size.
938 */
939 data = delta_head;
940
941 /* ignore base size */
942 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
943
944 /* Read the result size */
945 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
946 *sizep = result_size;
947 }
948 return 0;
949 }
950
951 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
952 enum object_type *type, unsigned long *sizep)
953 {
954 unsigned long used;
955
956 if (p->pack_size <= offset)
957 die("object offset outside of pack file");
958
959 used = unpack_object_header_gently((unsigned char *)p->pack_base +
960 offset,
961 p->pack_size - offset, type, sizep);
962 if (!used)
963 die("object offset outside of pack file");
964
965 return offset + used;
966 }
967
968 int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
969 unsigned char *base, unsigned long *sizep,
970 enum object_type *kindp)
971 {
972 unsigned long ptr;
973 int status = -1;
974
975 use_packed_git(p);
976 ptr = offset;
977 ptr = unpack_object_header(p, ptr, kindp, sizep);
978 if (*kindp != OBJ_DELTA)
979 goto done;
980 hashcpy(base, (unsigned char *) p->pack_base + ptr);
981 status = 0;
982 done:
983 unuse_packed_git(p);
984 return status;
985 }
986
987 void packed_object_info_detail(struct packed_git *p,
988 unsigned long offset,
989 char *type,
990 unsigned long *size,
991 unsigned long *store_size,
992 unsigned int *delta_chain_length,
993 unsigned char *base_sha1)
994 {
995 unsigned long val;
996 unsigned char *next_sha1;
997 enum object_type kind;
998
999 *delta_chain_length = 0;
1000 offset = unpack_object_header(p, offset, &kind, size);
1001
1002 for (;;) {
1003 switch (kind) {
1004 default:
1005 die("corrupted pack file %s containing object of kind %d",
1006 p->pack_name, kind);
1007 case OBJ_COMMIT:
1008 case OBJ_TREE:
1009 case OBJ_BLOB:
1010 case OBJ_TAG:
1011 strcpy(type, type_names[kind]);
1012 *store_size = 0; /* notyet */
1013 return;
1014 case OBJ_DELTA:
1015 if (p->pack_size <= offset + 20)
1016 die("pack file %s records an incomplete delta base",
1017 p->pack_name);
1018 next_sha1 = (unsigned char *) p->pack_base + offset;
1019 if (*delta_chain_length == 0)
1020 hashcpy(base_sha1, next_sha1);
1021 offset = find_pack_entry_one(next_sha1, p);
1022 break;
1023 }
1024 offset = unpack_object_header(p, offset, &kind, &val);
1025 (*delta_chain_length)++;
1026 }
1027 }
1028
1029 static int packed_object_info(struct packed_git *p, unsigned long offset,
1030 char *type, unsigned long *sizep)
1031 {
1032 unsigned long size;
1033 enum object_type kind;
1034
1035 offset = unpack_object_header(p, offset, &kind, &size);
1036
1037 if (kind == OBJ_DELTA)
1038 return packed_delta_info(p, offset, type, sizep);
1039
1040 switch (kind) {
1041 case OBJ_COMMIT:
1042 case OBJ_TREE:
1043 case OBJ_BLOB:
1044 case OBJ_TAG:
1045 strcpy(type, type_names[kind]);
1046 break;
1047 default:
1048 die("corrupted pack file %s containing object of kind %d",
1049 p->pack_name, kind);
1050 }
1051 if (sizep)
1052 *sizep = size;
1053 return 0;
1054 }
1055
1056 static void *unpack_compressed_entry(struct packed_git *p,
1057 unsigned long offset,
1058 unsigned long size)
1059 {
1060 int st;
1061 z_stream stream;
1062 unsigned char *buffer;
1063
1064 buffer = xmalloc(size + 1);
1065 buffer[size] = 0;
1066 memset(&stream, 0, sizeof(stream));
1067 stream.next_in = (unsigned char*)p->pack_base + offset;
1068 stream.avail_in = p->pack_size - offset;
1069 stream.next_out = buffer;
1070 stream.avail_out = size;
1071
1072 inflateInit(&stream);
1073 st = inflate(&stream, Z_FINISH);
1074 inflateEnd(&stream);
1075 if ((st != Z_STREAM_END) || stream.total_out != size) {
1076 free(buffer);
1077 return NULL;
1078 }
1079
1080 return buffer;
1081 }
1082
1083 static void *unpack_delta_entry(struct packed_git *p,
1084 unsigned long offset,
1085 unsigned long delta_size,
1086 char *type,
1087 unsigned long *sizep)
1088 {
1089 void *delta_data, *result, *base;
1090 unsigned long result_size, base_size, base_offset;
1091 unsigned char *base_sha1;
1092
1093 if (p->pack_size < offset + 20)
1094 die("truncated pack file");
1095 /* The base entry _must_ be in the same pack */
1096 base_sha1 = (unsigned char*)p->pack_base + offset;
1097 base_offset = find_pack_entry_one(base_sha1, p);
1098 if (!base_offset)
1099 die("failed to find delta-pack base object %s",
1100 sha1_to_hex(base_sha1));
1101 offset += 20;
1102
1103 base = unpack_entry_gently(p, base_offset, type, &base_size);
1104 if (!base)
1105 die("failed to read delta base object at %lu from %s",
1106 base_offset, p->pack_name);
1107
1108 delta_data = unpack_compressed_entry(p, offset, delta_size);
1109 result = patch_delta(base, base_size,
1110 delta_data, delta_size,
1111 &result_size);
1112 if (!result)
1113 die("failed to apply delta");
1114 free(delta_data);
1115 free(base);
1116 *sizep = result_size;
1117 return result;
1118 }
1119
1120 static void *unpack_entry(struct pack_entry *entry,
1121 char *type, unsigned long *sizep)
1122 {
1123 struct packed_git *p = entry->p;
1124 void *retval;
1125
1126 if (use_packed_git(p))
1127 die("cannot map packed file");
1128 retval = unpack_entry_gently(p, entry->offset, type, sizep);
1129 unuse_packed_git(p);
1130 if (!retval)
1131 die("corrupted pack file %s", p->pack_name);
1132 return retval;
1133 }
1134
1135 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1136 void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
1137 char *type, unsigned long *sizep)
1138 {
1139 unsigned long size;
1140 enum object_type kind;
1141
1142 offset = unpack_object_header(p, offset, &kind, &size);
1143 switch (kind) {
1144 case OBJ_DELTA:
1145 return unpack_delta_entry(p, offset, size, type, sizep);
1146 case OBJ_COMMIT:
1147 case OBJ_TREE:
1148 case OBJ_BLOB:
1149 case OBJ_TAG:
1150 strcpy(type, type_names[kind]);
1151 *sizep = size;
1152 return unpack_compressed_entry(p, offset, size);
1153 default:
1154 return NULL;
1155 }
1156 }
1157
1158 int num_packed_objects(const struct packed_git *p)
1159 {
1160 /* See check_packed_git_idx() */
1161 return (p->index_size - 20 - 20 - 4*256) / 24;
1162 }
1163
1164 int nth_packed_object_sha1(const struct packed_git *p, int n,
1165 unsigned char* sha1)
1166 {
1167 void *index = p->index_base + 256;
1168 if (n < 0 || num_packed_objects(p) <= n)
1169 return -1;
1170 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1171 return 0;
1172 }
1173
1174 unsigned long find_pack_entry_one(const unsigned char *sha1,
1175 struct packed_git *p)
1176 {
1177 unsigned int *level1_ofs = p->index_base;
1178 int hi = ntohl(level1_ofs[*sha1]);
1179 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1180 void *index = p->index_base + 256;
1181
1182 do {
1183 int mi = (lo + hi) / 2;
1184 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1185 if (!cmp)
1186 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1187 if (cmp > 0)
1188 hi = mi;
1189 else
1190 lo = mi+1;
1191 } while (lo < hi);
1192 return 0;
1193 }
1194
1195 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1196 {
1197 struct packed_git *p;
1198 unsigned long offset;
1199
1200 prepare_packed_git();
1201
1202 for (p = packed_git; p; p = p->next) {
1203 if (ignore_packed) {
1204 const char **ig;
1205 for (ig = ignore_packed; *ig; ig++)
1206 if (!strcmp(p->pack_name, *ig))
1207 break;
1208 if (*ig)
1209 continue;
1210 }
1211 offset = find_pack_entry_one(sha1, p);
1212 if (offset) {
1213 e->offset = offset;
1214 e->p = p;
1215 hashcpy(e->sha1, sha1);
1216 return 1;
1217 }
1218 }
1219 return 0;
1220 }
1221
1222 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1223 struct packed_git *packs)
1224 {
1225 struct packed_git *p;
1226
1227 for (p = packs; p; p = p->next) {
1228 if (find_pack_entry_one(sha1, p))
1229 return p;
1230 }
1231 return NULL;
1232
1233 }
1234
1235 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1236 {
1237 int status;
1238 unsigned long mapsize, size;
1239 void *map;
1240 z_stream stream;
1241 char hdr[128];
1242
1243 map = map_sha1_file(sha1, &mapsize);
1244 if (!map) {
1245 struct pack_entry e;
1246
1247 if (!find_pack_entry(sha1, &e, NULL)) {
1248 reprepare_packed_git();
1249 if (!find_pack_entry(sha1, &e, NULL))
1250 return error("unable to find %s", sha1_to_hex(sha1));
1251 }
1252 if (use_packed_git(e.p))
1253 die("cannot map packed file");
1254 status = packed_object_info(e.p, e.offset, type, sizep);
1255 unuse_packed_git(e.p);
1256 return status;
1257 }
1258 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1259 status = error("unable to unpack %s header",
1260 sha1_to_hex(sha1));
1261 if (parse_sha1_header(hdr, type, &size) < 0)
1262 status = error("unable to parse %s header", sha1_to_hex(sha1));
1263 else {
1264 status = 0;
1265 if (sizep)
1266 *sizep = size;
1267 }
1268 inflateEnd(&stream);
1269 munmap(map, mapsize);
1270 return status;
1271 }
1272
1273 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1274 {
1275 struct pack_entry e;
1276
1277 if (!find_pack_entry(sha1, &e, NULL)) {
1278 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1279 return NULL;
1280 }
1281 return unpack_entry(&e, type, size);
1282 }
1283
1284 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1285 {
1286 unsigned long mapsize;
1287 void *map, *buf;
1288 struct pack_entry e;
1289
1290 if (find_pack_entry(sha1, &e, NULL))
1291 return read_packed_sha1(sha1, type, size);
1292 map = map_sha1_file(sha1, &mapsize);
1293 if (map) {
1294 buf = unpack_sha1_file(map, mapsize, type, size);
1295 munmap(map, mapsize);
1296 return buf;
1297 }
1298 reprepare_packed_git();
1299 if (find_pack_entry(sha1, &e, NULL))
1300 return read_packed_sha1(sha1, type, size);
1301 return NULL;
1302 }
1303
1304 void *read_object_with_reference(const unsigned char *sha1,
1305 const char *required_type,
1306 unsigned long *size,
1307 unsigned char *actual_sha1_return)
1308 {
1309 char type[20];
1310 void *buffer;
1311 unsigned long isize;
1312 unsigned char actual_sha1[20];
1313
1314 hashcpy(actual_sha1, sha1);
1315 while (1) {
1316 int ref_length = -1;
1317 const char *ref_type = NULL;
1318
1319 buffer = read_sha1_file(actual_sha1, type, &isize);
1320 if (!buffer)
1321 return NULL;
1322 if (!strcmp(type, required_type)) {
1323 *size = isize;
1324 if (actual_sha1_return)
1325 hashcpy(actual_sha1_return, actual_sha1);
1326 return buffer;
1327 }
1328 /* Handle references */
1329 else if (!strcmp(type, commit_type))
1330 ref_type = "tree ";
1331 else if (!strcmp(type, tag_type))
1332 ref_type = "object ";
1333 else {
1334 free(buffer);
1335 return NULL;
1336 }
1337 ref_length = strlen(ref_type);
1338
1339 if (memcmp(buffer, ref_type, ref_length) ||
1340 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1341 free(buffer);
1342 return NULL;
1343 }
1344 free(buffer);
1345 /* Now we have the ID of the referred-to object in
1346 * actual_sha1. Check again. */
1347 }
1348 }
1349
1350 char *write_sha1_file_prepare(void *buf,
1351 unsigned long len,
1352 const char *type,
1353 unsigned char *sha1,
1354 unsigned char *hdr,
1355 int *hdrlen)
1356 {
1357 SHA_CTX c;
1358
1359 /* Generate the header */
1360 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1361
1362 /* Sha1.. */
1363 SHA1_Init(&c);
1364 SHA1_Update(&c, hdr, *hdrlen);
1365 SHA1_Update(&c, buf, len);
1366 SHA1_Final(sha1, &c);
1367
1368 return sha1_file_name(sha1);
1369 }
1370
1371 /*
1372 * Link the tempfile to the final place, possibly creating the
1373 * last directory level as you do so.
1374 *
1375 * Returns the errno on failure, 0 on success.
1376 */
1377 static int link_temp_to_file(const char *tmpfile, const char *filename)
1378 {
1379 int ret;
1380 char *dir;
1381
1382 if (!link(tmpfile, filename))
1383 return 0;
1384
1385 /*
1386 * Try to mkdir the last path component if that failed.
1387 *
1388 * Re-try the "link()" regardless of whether the mkdir
1389 * succeeds, since a race might mean that somebody
1390 * else succeeded.
1391 */
1392 ret = errno;
1393 dir = strrchr(filename, '/');
1394 if (dir) {
1395 *dir = 0;
1396 mkdir(filename, 0777);
1397 if (adjust_shared_perm(filename))
1398 return -2;
1399 *dir = '/';
1400 if (!link(tmpfile, filename))
1401 return 0;
1402 ret = errno;
1403 }
1404 return ret;
1405 }
1406
1407 /*
1408 * Move the just written object into its final resting place
1409 */
1410 int move_temp_to_file(const char *tmpfile, const char *filename)
1411 {
1412 int ret = link_temp_to_file(tmpfile, filename);
1413
1414 /*
1415 * Coda hack - coda doesn't like cross-directory links,
1416 * so we fall back to a rename, which will mean that it
1417 * won't be able to check collisions, but that's not a
1418 * big deal.
1419 *
1420 * The same holds for FAT formatted media.
1421 *
1422 * When this succeeds, we just return 0. We have nothing
1423 * left to unlink.
1424 */
1425 if (ret && ret != EEXIST) {
1426 if (!rename(tmpfile, filename))
1427 return 0;
1428 ret = errno;
1429 }
1430 unlink(tmpfile);
1431 if (ret) {
1432 if (ret != EEXIST) {
1433 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1434 return -1;
1435 }
1436 /* FIXME!!! Collision check here ? */
1437 }
1438
1439 return 0;
1440 }
1441
1442 static int write_buffer(int fd, const void *buf, size_t len)
1443 {
1444 while (len) {
1445 ssize_t size;
1446
1447 size = write(fd, buf, len);
1448 if (!size)
1449 return error("file write: disk full");
1450 if (size < 0) {
1451 if (errno == EINTR || errno == EAGAIN)
1452 continue;
1453 return error("file write error (%s)", strerror(errno));
1454 }
1455 len -= size;
1456 buf = (char *) buf + size;
1457 }
1458 return 0;
1459 }
1460
1461 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1462 {
1463 int hdr_len;
1464 unsigned char c;
1465
1466 c = (type << 4) | (len & 15);
1467 len >>= 4;
1468 hdr_len = 1;
1469 while (len) {
1470 *hdr++ = c | 0x80;
1471 hdr_len++;
1472 c = (len & 0x7f);
1473 len >>= 7;
1474 }
1475 *hdr = c;
1476 return hdr_len;
1477 }
1478
1479 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1480 {
1481 int obj_type, hdr;
1482
1483 if (use_legacy_headers) {
1484 while (deflate(stream, 0) == Z_OK)
1485 /* nothing */;
1486 return;
1487 }
1488 if (!strcmp(type, blob_type))
1489 obj_type = OBJ_BLOB;
1490 else if (!strcmp(type, tree_type))
1491 obj_type = OBJ_TREE;
1492 else if (!strcmp(type, commit_type))
1493 obj_type = OBJ_COMMIT;
1494 else if (!strcmp(type, tag_type))
1495 obj_type = OBJ_TAG;
1496 else
1497 die("trying to generate bogus object of type '%s'", type);
1498 hdr = write_binary_header(stream->next_out, obj_type, len);
1499 stream->total_out = hdr;
1500 stream->next_out += hdr;
1501 stream->avail_out -= hdr;
1502 }
1503
1504 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1505 {
1506 int size;
1507 unsigned char *compressed;
1508 z_stream stream;
1509 unsigned char sha1[20];
1510 char *filename;
1511 static char tmpfile[PATH_MAX];
1512 unsigned char hdr[50];
1513 int fd, hdrlen;
1514
1515 /* Normally if we have it in the pack then we do not bother writing
1516 * it out into .git/objects/??/?{38} file.
1517 */
1518 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1519 if (returnsha1)
1520 hashcpy(returnsha1, sha1);
1521 if (has_sha1_file(sha1))
1522 return 0;
1523 fd = open(filename, O_RDONLY);
1524 if (fd >= 0) {
1525 /*
1526 * FIXME!!! We might do collision checking here, but we'd
1527 * need to uncompress the old file and check it. Later.
1528 */
1529 close(fd);
1530 return 0;
1531 }
1532
1533 if (errno != ENOENT) {
1534 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1535 return -1;
1536 }
1537
1538 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1539
1540 fd = mkstemp(tmpfile);
1541 if (fd < 0) {
1542 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1543 return -1;
1544 }
1545
1546 /* Set it up */
1547 memset(&stream, 0, sizeof(stream));
1548 deflateInit(&stream, zlib_compression_level);
1549 size = 8 + deflateBound(&stream, len+hdrlen);
1550 compressed = xmalloc(size);
1551
1552 /* Compress it */
1553 stream.next_out = compressed;
1554 stream.avail_out = size;
1555
1556 /* First header.. */
1557 stream.next_in = hdr;
1558 stream.avail_in = hdrlen;
1559 setup_object_header(&stream, type, len);
1560
1561 /* Then the data itself.. */
1562 stream.next_in = buf;
1563 stream.avail_in = len;
1564 while (deflate(&stream, Z_FINISH) == Z_OK)
1565 /* nothing */;
1566 deflateEnd(&stream);
1567 size = stream.total_out;
1568
1569 if (write_buffer(fd, compressed, size) < 0)
1570 die("unable to write sha1 file");
1571 fchmod(fd, 0444);
1572 close(fd);
1573 free(compressed);
1574
1575 return move_temp_to_file(tmpfile, filename);
1576 }
1577
1578 /*
1579 * We need to unpack and recompress the object for writing
1580 * it out to a different file.
1581 */
1582 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1583 {
1584 size_t size;
1585 z_stream stream;
1586 unsigned char *unpacked;
1587 unsigned long len;
1588 char type[20];
1589 char hdr[50];
1590 int hdrlen;
1591 void *buf;
1592
1593 /* need to unpack and recompress it by itself */
1594 unpacked = read_packed_sha1(sha1, type, &len);
1595
1596 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1597
1598 /* Set it up */
1599 memset(&stream, 0, sizeof(stream));
1600 deflateInit(&stream, zlib_compression_level);
1601 size = deflateBound(&stream, len + hdrlen);
1602 buf = xmalloc(size);
1603
1604 /* Compress it */
1605 stream.next_out = buf;
1606 stream.avail_out = size;
1607
1608 /* First header.. */
1609 stream.next_in = (void *)hdr;
1610 stream.avail_in = hdrlen;
1611 while (deflate(&stream, 0) == Z_OK)
1612 /* nothing */;
1613
1614 /* Then the data itself.. */
1615 stream.next_in = unpacked;
1616 stream.avail_in = len;
1617 while (deflate(&stream, Z_FINISH) == Z_OK)
1618 /* nothing */;
1619 deflateEnd(&stream);
1620 free(unpacked);
1621
1622 *objsize = stream.total_out;
1623 return buf;
1624 }
1625
1626 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1627 {
1628 int retval;
1629 unsigned long objsize;
1630 void *buf = map_sha1_file(sha1, &objsize);
1631
1632 if (buf) {
1633 retval = write_buffer(fd, buf, objsize);
1634 munmap(buf, objsize);
1635 return retval;
1636 }
1637
1638 buf = repack_object(sha1, &objsize);
1639 retval = write_buffer(fd, buf, objsize);
1640 free(buf);
1641 return retval;
1642 }
1643
1644 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1645 size_t bufsize, size_t *bufposn)
1646 {
1647 char tmpfile[PATH_MAX];
1648 int local;
1649 z_stream stream;
1650 unsigned char real_sha1[20];
1651 unsigned char discard[4096];
1652 int ret;
1653 SHA_CTX c;
1654
1655 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1656
1657 local = mkstemp(tmpfile);
1658 if (local < 0)
1659 return error("Couldn't open %s for %s",
1660 tmpfile, sha1_to_hex(sha1));
1661
1662 memset(&stream, 0, sizeof(stream));
1663
1664 inflateInit(&stream);
1665
1666 SHA1_Init(&c);
1667
1668 do {
1669 ssize_t size;
1670 if (*bufposn) {
1671 stream.avail_in = *bufposn;
1672 stream.next_in = (unsigned char *) buffer;
1673 do {
1674 stream.next_out = discard;
1675 stream.avail_out = sizeof(discard);
1676 ret = inflate(&stream, Z_SYNC_FLUSH);
1677 SHA1_Update(&c, discard, sizeof(discard) -
1678 stream.avail_out);
1679 } while (stream.avail_in && ret == Z_OK);
1680 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1681 die("unable to write sha1 file");
1682 memmove(buffer, buffer + *bufposn - stream.avail_in,
1683 stream.avail_in);
1684 *bufposn = stream.avail_in;
1685 if (ret != Z_OK)
1686 break;
1687 }
1688 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1689 if (size <= 0) {
1690 close(local);
1691 unlink(tmpfile);
1692 if (!size)
1693 return error("Connection closed?");
1694 perror("Reading from connection");
1695 return -1;
1696 }
1697 *bufposn += size;
1698 } while (1);
1699 inflateEnd(&stream);
1700
1701 close(local);
1702 SHA1_Final(real_sha1, &c);
1703 if (ret != Z_STREAM_END) {
1704 unlink(tmpfile);
1705 return error("File %s corrupted", sha1_to_hex(sha1));
1706 }
1707 if (hashcmp(sha1, real_sha1)) {
1708 unlink(tmpfile);
1709 return error("File %s has bad hash", sha1_to_hex(sha1));
1710 }
1711
1712 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1713 }
1714
1715 int has_pack_index(const unsigned char *sha1)
1716 {
1717 struct stat st;
1718 if (stat(sha1_pack_index_name(sha1), &st))
1719 return 0;
1720 return 1;
1721 }
1722
1723 int has_pack_file(const unsigned char *sha1)
1724 {
1725 struct stat st;
1726 if (stat(sha1_pack_name(sha1), &st))
1727 return 0;
1728 return 1;
1729 }
1730
1731 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1732 {
1733 struct pack_entry e;
1734 return find_pack_entry(sha1, &e, ignore_packed);
1735 }
1736
1737 int has_sha1_file(const unsigned char *sha1)
1738 {
1739 struct stat st;
1740 struct pack_entry e;
1741
1742 if (find_pack_entry(sha1, &e, NULL))
1743 return 1;
1744 return find_sha1_file(sha1, &st) ? 1 : 0;
1745 }
1746
1747 /*
1748 * reads from fd as long as possible into a supplied buffer of size bytes.
1749 * If necessary the buffer's size is increased using realloc()
1750 *
1751 * returns 0 if anything went fine and -1 otherwise
1752 *
1753 * NOTE: both buf and size may change, but even when -1 is returned
1754 * you still have to free() it yourself.
1755 */
1756 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1757 {
1758 char* buf = *return_buf;
1759 unsigned long size = *return_size;
1760 int iret;
1761 unsigned long off = 0;
1762
1763 do {
1764 iret = xread(fd, buf + off, size - off);
1765 if (iret > 0) {
1766 off += iret;
1767 if (off == size) {
1768 size *= 2;
1769 buf = xrealloc(buf, size);
1770 }
1771 }
1772 } while (iret > 0);
1773
1774 *return_buf = buf;
1775 *return_size = off;
1776
1777 if (iret < 0)
1778 return -1;
1779 return 0;
1780 }
1781
1782 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1783 {
1784 unsigned long size = 4096;
1785 char *buf = xmalloc(size);
1786 int ret;
1787 unsigned char hdr[50];
1788 int hdrlen;
1789
1790 if (read_pipe(fd, &buf, &size)) {
1791 free(buf);
1792 return -1;
1793 }
1794
1795 if (!type)
1796 type = blob_type;
1797 if (write_object)
1798 ret = write_sha1_file(buf, size, type, sha1);
1799 else {
1800 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1801 ret = 0;
1802 }
1803 free(buf);
1804 return ret;
1805 }
1806
1807 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1808 {
1809 unsigned long size = st->st_size;
1810 void *buf;
1811 int ret;
1812 unsigned char hdr[50];
1813 int hdrlen;
1814
1815 buf = "";
1816 if (size)
1817 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1818 close(fd);
1819 if (buf == MAP_FAILED)
1820 return -1;
1821
1822 if (!type)
1823 type = blob_type;
1824 if (write_object)
1825 ret = write_sha1_file(buf, size, type, sha1);
1826 else {
1827 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1828 ret = 0;
1829 }
1830 if (size)
1831 munmap(buf, size);
1832 return ret;
1833 }
1834
1835 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1836 {
1837 int fd;
1838 char *target;
1839
1840 switch (st->st_mode & S_IFMT) {
1841 case S_IFREG:
1842 fd = open(path, O_RDONLY);
1843 if (fd < 0)
1844 return error("open(\"%s\"): %s", path,
1845 strerror(errno));
1846 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1847 return error("%s: failed to insert into database",
1848 path);
1849 break;
1850 case S_IFLNK:
1851 target = xmalloc(st->st_size+1);
1852 if (readlink(path, target, st->st_size+1) != st->st_size) {
1853 char *errstr = strerror(errno);
1854 free(target);
1855 return error("readlink(\"%s\"): %s", path,
1856 errstr);
1857 }
1858 if (!write_object) {
1859 unsigned char hdr[50];
1860 int hdrlen;
1861 write_sha1_file_prepare(target, st->st_size, blob_type,
1862 sha1, hdr, &hdrlen);
1863 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1864 return error("%s: failed to insert into database",
1865 path);
1866 free(target);
1867 break;
1868 default:
1869 return error("%s: unsupported file type", path);
1870 }
1871 return 0;
1872 }