sha1_object_info(): be consistent with read_sha1_file()
[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 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 unsigned char real_sha1[20];
675 hash_sha1_file(map, size, type, real_sha1);
676 return hashcmp(sha1, real_sha1) ? -1 : 0;
677 }
678
679 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
680 {
681 struct stat st;
682 void *map;
683 int fd;
684 char *filename = find_sha1_file(sha1, &st);
685
686 if (!filename) {
687 return NULL;
688 }
689
690 fd = open(filename, O_RDONLY | sha1_file_open_flag);
691 if (fd < 0) {
692 /* See if it works without O_NOATIME */
693 switch (sha1_file_open_flag) {
694 default:
695 fd = open(filename, O_RDONLY);
696 if (fd >= 0)
697 break;
698 /* Fallthrough */
699 case 0:
700 return NULL;
701 }
702
703 /* If it failed once, it will probably fail again.
704 * Stop using O_NOATIME
705 */
706 sha1_file_open_flag = 0;
707 }
708 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
709 close(fd);
710 if (map == MAP_FAILED)
711 return NULL;
712 *size = st.st_size;
713 return map;
714 }
715
716 int legacy_loose_object(unsigned char *map)
717 {
718 unsigned int word;
719
720 /*
721 * Is it a zlib-compressed buffer? If so, the first byte
722 * must be 0x78 (15-bit window size, deflated), and the
723 * first 16-bit word is evenly divisible by 31
724 */
725 word = (map[0] << 8) + map[1];
726 if (map[0] == 0x78 && !(word % 31))
727 return 1;
728 else
729 return 0;
730 }
731
732 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
733 {
734 unsigned shift;
735 unsigned char c;
736 unsigned long size;
737 unsigned long used = 0;
738
739 c = buf[used++];
740 *type = (c >> 4) & 7;
741 size = c & 15;
742 shift = 4;
743 while (c & 0x80) {
744 if (len <= used)
745 return 0;
746 if (sizeof(long) * 8 <= shift)
747 return 0;
748 c = buf[used++];
749 size += (c & 0x7f) << shift;
750 shift += 7;
751 }
752 *sizep = size;
753 return used;
754 }
755
756 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
757 {
758 unsigned long size, used;
759 static const char valid_loose_object_type[8] = {
760 0, /* OBJ_EXT */
761 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
762 0, /* "delta" and others are invalid in a loose object */
763 };
764 enum object_type type;
765
766 /* Get the data stream */
767 memset(stream, 0, sizeof(*stream));
768 stream->next_in = map;
769 stream->avail_in = mapsize;
770 stream->next_out = buffer;
771 stream->avail_out = bufsiz;
772
773 if (legacy_loose_object(map)) {
774 inflateInit(stream);
775 return inflate(stream, 0);
776 }
777
778 used = unpack_object_header_gently(map, mapsize, &type, &size);
779 if (!used || !valid_loose_object_type[type])
780 return -1;
781 map += used;
782 mapsize -= used;
783
784 /* Set up the stream for the rest.. */
785 stream->next_in = map;
786 stream->avail_in = mapsize;
787 inflateInit(stream);
788
789 /* And generate the fake traditional header */
790 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
791 type_names[type], size);
792 return 0;
793 }
794
795 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
796 {
797 int bytes = strlen(buffer) + 1;
798 unsigned char *buf = xmalloc(1+size);
799 unsigned long n;
800
801 n = stream->total_out - bytes;
802 if (n > size)
803 n = size;
804 memcpy(buf, (char *) buffer + bytes, n);
805 bytes = n;
806 if (bytes < size) {
807 stream->next_out = buf + bytes;
808 stream->avail_out = size - bytes;
809 while (inflate(stream, Z_FINISH) == Z_OK)
810 /* nothing */;
811 }
812 buf[size] = 0;
813 inflateEnd(stream);
814 return buf;
815 }
816
817 /*
818 * We used to just use "sscanf()", but that's actually way
819 * too permissive for what we want to check. So do an anal
820 * object header parse by hand.
821 */
822 static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
823 {
824 int i;
825 unsigned long size;
826
827 /*
828 * The type can be at most ten bytes (including the
829 * terminating '\0' that we add), and is followed by
830 * a space.
831 */
832 i = 10;
833 for (;;) {
834 char c = *hdr++;
835 if (c == ' ')
836 break;
837 if (!--i)
838 return -1;
839 *type++ = c;
840 }
841 *type = 0;
842
843 /*
844 * The length must follow immediately, and be in canonical
845 * decimal format (ie "010" is not valid).
846 */
847 size = *hdr++ - '0';
848 if (size > 9)
849 return -1;
850 if (size) {
851 for (;;) {
852 unsigned long c = *hdr - '0';
853 if (c > 9)
854 break;
855 hdr++;
856 size = size * 10 + c;
857 }
858 }
859 *sizep = size;
860
861 /*
862 * The length must be followed by a zero byte
863 */
864 return *hdr ? -1 : 0;
865 }
866
867 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
868 {
869 int ret;
870 z_stream stream;
871 char hdr[8192];
872
873 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
874 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
875 return NULL;
876
877 return unpack_sha1_rest(&stream, hdr, *size);
878 }
879
880 static unsigned long get_delta_base(struct packed_git *p,
881 unsigned long offset,
882 enum object_type kind,
883 unsigned long delta_obj_offset,
884 unsigned long *base_obj_offset)
885 {
886 unsigned char *base_info = (unsigned char *) p->pack_base + offset;
887 unsigned long base_offset;
888
889 /* there must be at least 20 bytes left regardless of delta type */
890 if (p->pack_size <= offset + 20)
891 die("truncated pack file");
892
893 if (kind == OBJ_OFS_DELTA) {
894 unsigned used = 0;
895 unsigned char c = base_info[used++];
896 base_offset = c & 127;
897 while (c & 128) {
898 base_offset += 1;
899 if (!base_offset || base_offset & ~(~0UL >> 7))
900 die("offset value overflow for delta base object");
901 c = base_info[used++];
902 base_offset = (base_offset << 7) + (c & 127);
903 }
904 base_offset = delta_obj_offset - base_offset;
905 if (base_offset >= delta_obj_offset)
906 die("delta base offset out of bound");
907 offset += used;
908 } else if (kind == OBJ_REF_DELTA) {
909 /* The base entry _must_ be in the same pack */
910 base_offset = find_pack_entry_one(base_info, p);
911 if (!base_offset)
912 die("failed to find delta-pack base object %s",
913 sha1_to_hex(base_info));
914 offset += 20;
915 } else
916 die("I am totally screwed");
917 *base_obj_offset = base_offset;
918 return offset;
919 }
920
921 /* forward declaration for a mutually recursive function */
922 static int packed_object_info(struct packed_git *p, unsigned long offset,
923 char *type, unsigned long *sizep);
924
925 static int packed_delta_info(struct packed_git *p,
926 unsigned long offset,
927 enum object_type kind,
928 unsigned long obj_offset,
929 char *type,
930 unsigned long *sizep)
931 {
932 unsigned long base_offset;
933
934 offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
935
936 /* We choose to only get the type of the base object and
937 * ignore potentially corrupt pack file that expects the delta
938 * based on a base with a wrong size. This saves tons of
939 * inflate() calls.
940 */
941 if (packed_object_info(p, base_offset, type, NULL))
942 die("cannot get info for delta-pack base");
943
944 if (sizep) {
945 const unsigned char *data;
946 unsigned char delta_head[20];
947 unsigned long result_size;
948 z_stream stream;
949 int st;
950
951 memset(&stream, 0, sizeof(stream));
952
953 stream.next_in = (unsigned char *) p->pack_base + offset;
954 stream.avail_in = p->pack_size - offset;
955 stream.next_out = delta_head;
956 stream.avail_out = sizeof(delta_head);
957
958 inflateInit(&stream);
959 st = inflate(&stream, Z_FINISH);
960 inflateEnd(&stream);
961 if ((st != Z_STREAM_END) &&
962 stream.total_out != sizeof(delta_head))
963 die("delta data unpack-initial failed");
964
965 /* Examine the initial part of the delta to figure out
966 * the result size.
967 */
968 data = delta_head;
969
970 /* ignore base size */
971 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
972
973 /* Read the result size */
974 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
975 *sizep = result_size;
976 }
977 return 0;
978 }
979
980 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
981 enum object_type *type, unsigned long *sizep)
982 {
983 unsigned long used;
984
985 if (p->pack_size <= offset)
986 die("object offset outside of pack file");
987
988 used = unpack_object_header_gently((unsigned char *)p->pack_base +
989 offset,
990 p->pack_size - offset, type, sizep);
991 if (!used)
992 die("object offset outside of pack file");
993
994 return offset + used;
995 }
996
997 void packed_object_info_detail(struct packed_git *p,
998 unsigned long offset,
999 char *type,
1000 unsigned long *size,
1001 unsigned long *store_size,
1002 unsigned int *delta_chain_length,
1003 unsigned char *base_sha1)
1004 {
1005 unsigned long obj_offset, val;
1006 unsigned char *next_sha1;
1007 enum object_type kind;
1008
1009 *delta_chain_length = 0;
1010 obj_offset = offset;
1011 offset = unpack_object_header(p, offset, &kind, size);
1012
1013 for (;;) {
1014 switch (kind) {
1015 default:
1016 die("corrupted pack file %s containing object of kind %d",
1017 p->pack_name, kind);
1018 case OBJ_COMMIT:
1019 case OBJ_TREE:
1020 case OBJ_BLOB:
1021 case OBJ_TAG:
1022 strcpy(type, type_names[kind]);
1023 *store_size = 0; /* notyet */
1024 return;
1025 case OBJ_OFS_DELTA:
1026 get_delta_base(p, offset, kind, obj_offset, &offset);
1027 if (*delta_chain_length == 0) {
1028 /* TODO: find base_sha1 as pointed by offset */
1029 }
1030 break;
1031 case OBJ_REF_DELTA:
1032 if (p->pack_size <= offset + 20)
1033 die("pack file %s records an incomplete delta base",
1034 p->pack_name);
1035 next_sha1 = (unsigned char *) p->pack_base + offset;
1036 if (*delta_chain_length == 0)
1037 hashcpy(base_sha1, next_sha1);
1038 offset = find_pack_entry_one(next_sha1, p);
1039 break;
1040 }
1041 obj_offset = offset;
1042 offset = unpack_object_header(p, offset, &kind, &val);
1043 (*delta_chain_length)++;
1044 }
1045 }
1046
1047 static int packed_object_info(struct packed_git *p, unsigned long offset,
1048 char *type, unsigned long *sizep)
1049 {
1050 unsigned long size, obj_offset = offset;
1051 enum object_type kind;
1052
1053 offset = unpack_object_header(p, offset, &kind, &size);
1054
1055 switch (kind) {
1056 case OBJ_OFS_DELTA:
1057 case OBJ_REF_DELTA:
1058 return packed_delta_info(p, offset, kind, obj_offset, type, sizep);
1059 case OBJ_COMMIT:
1060 case OBJ_TREE:
1061 case OBJ_BLOB:
1062 case OBJ_TAG:
1063 strcpy(type, type_names[kind]);
1064 break;
1065 default:
1066 die("corrupted pack file %s containing object of kind %d",
1067 p->pack_name, kind);
1068 }
1069 if (sizep)
1070 *sizep = size;
1071 return 0;
1072 }
1073
1074 static void *unpack_compressed_entry(struct packed_git *p,
1075 unsigned long offset,
1076 unsigned long size)
1077 {
1078 int st;
1079 z_stream stream;
1080 unsigned char *buffer;
1081
1082 buffer = xmalloc(size + 1);
1083 buffer[size] = 0;
1084 memset(&stream, 0, sizeof(stream));
1085 stream.next_in = (unsigned char*)p->pack_base + offset;
1086 stream.avail_in = p->pack_size - offset;
1087 stream.next_out = buffer;
1088 stream.avail_out = size;
1089
1090 inflateInit(&stream);
1091 st = inflate(&stream, Z_FINISH);
1092 inflateEnd(&stream);
1093 if ((st != Z_STREAM_END) || stream.total_out != size) {
1094 free(buffer);
1095 return NULL;
1096 }
1097
1098 return buffer;
1099 }
1100
1101 static void *unpack_delta_entry(struct packed_git *p,
1102 unsigned long offset,
1103 unsigned long delta_size,
1104 enum object_type kind,
1105 unsigned long obj_offset,
1106 char *type,
1107 unsigned long *sizep)
1108 {
1109 void *delta_data, *result, *base;
1110 unsigned long result_size, base_size, base_offset;
1111
1112 offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
1113 base = unpack_entry_gently(p, base_offset, type, &base_size);
1114 if (!base)
1115 die("failed to read delta base object at %lu from %s",
1116 base_offset, p->pack_name);
1117
1118 delta_data = unpack_compressed_entry(p, offset, delta_size);
1119 result = patch_delta(base, base_size,
1120 delta_data, delta_size,
1121 &result_size);
1122 if (!result)
1123 die("failed to apply delta");
1124 free(delta_data);
1125 free(base);
1126 *sizep = result_size;
1127 return result;
1128 }
1129
1130 static void *unpack_entry(struct pack_entry *entry,
1131 char *type, unsigned long *sizep)
1132 {
1133 struct packed_git *p = entry->p;
1134 void *retval;
1135
1136 if (use_packed_git(p))
1137 die("cannot map packed file");
1138 retval = unpack_entry_gently(p, entry->offset, type, sizep);
1139 unuse_packed_git(p);
1140 if (!retval)
1141 die("corrupted pack file %s", p->pack_name);
1142 return retval;
1143 }
1144
1145 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1146 void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
1147 char *type, unsigned long *sizep)
1148 {
1149 unsigned long size, obj_offset = offset;
1150 enum object_type kind;
1151
1152 offset = unpack_object_header(p, offset, &kind, &size);
1153 switch (kind) {
1154 case OBJ_OFS_DELTA:
1155 case OBJ_REF_DELTA:
1156 return unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep);
1157 case OBJ_COMMIT:
1158 case OBJ_TREE:
1159 case OBJ_BLOB:
1160 case OBJ_TAG:
1161 strcpy(type, type_names[kind]);
1162 *sizep = size;
1163 return unpack_compressed_entry(p, offset, size);
1164 default:
1165 return NULL;
1166 }
1167 }
1168
1169 int num_packed_objects(const struct packed_git *p)
1170 {
1171 /* See check_packed_git_idx() */
1172 return (p->index_size - 20 - 20 - 4*256) / 24;
1173 }
1174
1175 int nth_packed_object_sha1(const struct packed_git *p, int n,
1176 unsigned char* sha1)
1177 {
1178 void *index = p->index_base + 256;
1179 if (n < 0 || num_packed_objects(p) <= n)
1180 return -1;
1181 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1182 return 0;
1183 }
1184
1185 unsigned long find_pack_entry_one(const unsigned char *sha1,
1186 struct packed_git *p)
1187 {
1188 unsigned int *level1_ofs = p->index_base;
1189 int hi = ntohl(level1_ofs[*sha1]);
1190 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1191 void *index = p->index_base + 256;
1192
1193 do {
1194 int mi = (lo + hi) / 2;
1195 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1196 if (!cmp)
1197 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1198 if (cmp > 0)
1199 hi = mi;
1200 else
1201 lo = mi+1;
1202 } while (lo < hi);
1203 return 0;
1204 }
1205
1206 static int matches_pack_name(struct packed_git *p, const char *ig)
1207 {
1208 const char *last_c, *c;
1209
1210 if (!strcmp(p->pack_name, ig))
1211 return 0;
1212
1213 for (c = p->pack_name, last_c = c; *c;)
1214 if (*c == '/')
1215 last_c = ++c;
1216 else
1217 ++c;
1218 if (!strcmp(last_c, ig))
1219 return 0;
1220
1221 return 1;
1222 }
1223
1224 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1225 {
1226 struct packed_git *p;
1227 unsigned long offset;
1228
1229 prepare_packed_git();
1230
1231 for (p = packed_git; p; p = p->next) {
1232 if (ignore_packed) {
1233 const char **ig;
1234 for (ig = ignore_packed; *ig; ig++)
1235 if (!matches_pack_name(p, *ig))
1236 break;
1237 if (*ig)
1238 continue;
1239 }
1240 offset = find_pack_entry_one(sha1, p);
1241 if (offset) {
1242 e->offset = offset;
1243 e->p = p;
1244 hashcpy(e->sha1, sha1);
1245 return 1;
1246 }
1247 }
1248 return 0;
1249 }
1250
1251 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1252 struct packed_git *packs)
1253 {
1254 struct packed_git *p;
1255
1256 for (p = packs; p; p = p->next) {
1257 if (find_pack_entry_one(sha1, p))
1258 return p;
1259 }
1260 return NULL;
1261
1262 }
1263
1264 static int sha1_loose_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1265 {
1266 int status;
1267 unsigned long mapsize, size;
1268 void *map;
1269 z_stream stream;
1270 char hdr[128];
1271
1272 map = map_sha1_file(sha1, &mapsize);
1273 if (!map)
1274 return error("unable to find %s", sha1_to_hex(sha1));
1275 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1276 status = error("unable to unpack %s header",
1277 sha1_to_hex(sha1));
1278 if (parse_sha1_header(hdr, type, &size) < 0)
1279 status = error("unable to parse %s header", sha1_to_hex(sha1));
1280 else {
1281 status = 0;
1282 if (sizep)
1283 *sizep = size;
1284 }
1285 inflateEnd(&stream);
1286 munmap(map, mapsize);
1287 return status;
1288 }
1289
1290 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1291 {
1292 int status;
1293 struct pack_entry e;
1294
1295 if (!find_pack_entry(sha1, &e, NULL)) {
1296 reprepare_packed_git();
1297 if (!find_pack_entry(sha1, &e, NULL))
1298 return sha1_loose_object_info(sha1, type, sizep);
1299 }
1300 if (use_packed_git(e.p))
1301 die("cannot map packed file");
1302 status = packed_object_info(e.p, e.offset, type, sizep);
1303 unuse_packed_git(e.p);
1304 return status;
1305 }
1306
1307 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1308 {
1309 struct pack_entry e;
1310
1311 if (!find_pack_entry(sha1, &e, NULL)) {
1312 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1313 return NULL;
1314 }
1315 return unpack_entry(&e, type, size);
1316 }
1317
1318 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1319 {
1320 unsigned long mapsize;
1321 void *map, *buf;
1322 struct pack_entry e;
1323
1324 if (find_pack_entry(sha1, &e, NULL))
1325 return read_packed_sha1(sha1, type, size);
1326 map = map_sha1_file(sha1, &mapsize);
1327 if (map) {
1328 buf = unpack_sha1_file(map, mapsize, type, size);
1329 munmap(map, mapsize);
1330 return buf;
1331 }
1332 reprepare_packed_git();
1333 if (find_pack_entry(sha1, &e, NULL))
1334 return read_packed_sha1(sha1, type, size);
1335 return NULL;
1336 }
1337
1338 void *read_object_with_reference(const unsigned char *sha1,
1339 const char *required_type,
1340 unsigned long *size,
1341 unsigned char *actual_sha1_return)
1342 {
1343 char type[20];
1344 void *buffer;
1345 unsigned long isize;
1346 unsigned char actual_sha1[20];
1347
1348 hashcpy(actual_sha1, sha1);
1349 while (1) {
1350 int ref_length = -1;
1351 const char *ref_type = NULL;
1352
1353 buffer = read_sha1_file(actual_sha1, type, &isize);
1354 if (!buffer)
1355 return NULL;
1356 if (!strcmp(type, required_type)) {
1357 *size = isize;
1358 if (actual_sha1_return)
1359 hashcpy(actual_sha1_return, actual_sha1);
1360 return buffer;
1361 }
1362 /* Handle references */
1363 else if (!strcmp(type, commit_type))
1364 ref_type = "tree ";
1365 else if (!strcmp(type, tag_type))
1366 ref_type = "object ";
1367 else {
1368 free(buffer);
1369 return NULL;
1370 }
1371 ref_length = strlen(ref_type);
1372
1373 if (memcmp(buffer, ref_type, ref_length) ||
1374 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1375 free(buffer);
1376 return NULL;
1377 }
1378 free(buffer);
1379 /* Now we have the ID of the referred-to object in
1380 * actual_sha1. Check again. */
1381 }
1382 }
1383
1384 static void write_sha1_file_prepare(void *buf, unsigned long len,
1385 const char *type, unsigned char *sha1,
1386 unsigned char *hdr, int *hdrlen)
1387 {
1388 SHA_CTX c;
1389
1390 /* Generate the header */
1391 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1392
1393 /* Sha1.. */
1394 SHA1_Init(&c);
1395 SHA1_Update(&c, hdr, *hdrlen);
1396 SHA1_Update(&c, buf, len);
1397 SHA1_Final(sha1, &c);
1398 }
1399
1400 /*
1401 * Link the tempfile to the final place, possibly creating the
1402 * last directory level as you do so.
1403 *
1404 * Returns the errno on failure, 0 on success.
1405 */
1406 static int link_temp_to_file(const char *tmpfile, const char *filename)
1407 {
1408 int ret;
1409 char *dir;
1410
1411 if (!link(tmpfile, filename))
1412 return 0;
1413
1414 /*
1415 * Try to mkdir the last path component if that failed.
1416 *
1417 * Re-try the "link()" regardless of whether the mkdir
1418 * succeeds, since a race might mean that somebody
1419 * else succeeded.
1420 */
1421 ret = errno;
1422 dir = strrchr(filename, '/');
1423 if (dir) {
1424 *dir = 0;
1425 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
1426 *dir = '/';
1427 return -2;
1428 }
1429 *dir = '/';
1430 if (!link(tmpfile, filename))
1431 return 0;
1432 ret = errno;
1433 }
1434 return ret;
1435 }
1436
1437 /*
1438 * Move the just written object into its final resting place
1439 */
1440 int move_temp_to_file(const char *tmpfile, const char *filename)
1441 {
1442 int ret = link_temp_to_file(tmpfile, filename);
1443
1444 /*
1445 * Coda hack - coda doesn't like cross-directory links,
1446 * so we fall back to a rename, which will mean that it
1447 * won't be able to check collisions, but that's not a
1448 * big deal.
1449 *
1450 * The same holds for FAT formatted media.
1451 *
1452 * When this succeeds, we just return 0. We have nothing
1453 * left to unlink.
1454 */
1455 if (ret && ret != EEXIST) {
1456 if (!rename(tmpfile, filename))
1457 return 0;
1458 ret = errno;
1459 }
1460 unlink(tmpfile);
1461 if (ret) {
1462 if (ret != EEXIST) {
1463 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1464 }
1465 /* FIXME!!! Collision check here ? */
1466 }
1467
1468 return 0;
1469 }
1470
1471 static int write_buffer(int fd, const void *buf, size_t len)
1472 {
1473 while (len) {
1474 ssize_t size;
1475
1476 size = write(fd, buf, len);
1477 if (!size)
1478 return error("file write: disk full");
1479 if (size < 0) {
1480 if (errno == EINTR || errno == EAGAIN)
1481 continue;
1482 return error("file write error (%s)", strerror(errno));
1483 }
1484 len -= size;
1485 buf = (char *) buf + size;
1486 }
1487 return 0;
1488 }
1489
1490 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1491 {
1492 int hdr_len;
1493 unsigned char c;
1494
1495 c = (type << 4) | (len & 15);
1496 len >>= 4;
1497 hdr_len = 1;
1498 while (len) {
1499 *hdr++ = c | 0x80;
1500 hdr_len++;
1501 c = (len & 0x7f);
1502 len >>= 7;
1503 }
1504 *hdr = c;
1505 return hdr_len;
1506 }
1507
1508 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1509 {
1510 int obj_type, hdr;
1511
1512 if (use_legacy_headers) {
1513 while (deflate(stream, 0) == Z_OK)
1514 /* nothing */;
1515 return;
1516 }
1517 if (!strcmp(type, blob_type))
1518 obj_type = OBJ_BLOB;
1519 else if (!strcmp(type, tree_type))
1520 obj_type = OBJ_TREE;
1521 else if (!strcmp(type, commit_type))
1522 obj_type = OBJ_COMMIT;
1523 else if (!strcmp(type, tag_type))
1524 obj_type = OBJ_TAG;
1525 else
1526 die("trying to generate bogus object of type '%s'", type);
1527 hdr = write_binary_header(stream->next_out, obj_type, len);
1528 stream->total_out = hdr;
1529 stream->next_out += hdr;
1530 stream->avail_out -= hdr;
1531 }
1532
1533 int hash_sha1_file(void *buf, unsigned long len, const char *type,
1534 unsigned char *sha1)
1535 {
1536 unsigned char hdr[50];
1537 int hdrlen;
1538 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1539 return 0;
1540 }
1541
1542 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1543 {
1544 int size;
1545 unsigned char *compressed;
1546 z_stream stream;
1547 unsigned char sha1[20];
1548 char *filename;
1549 static char tmpfile[PATH_MAX];
1550 unsigned char hdr[50];
1551 int fd, hdrlen;
1552
1553 /* Normally if we have it in the pack then we do not bother writing
1554 * it out into .git/objects/??/?{38} file.
1555 */
1556 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1557 filename = sha1_file_name(sha1);
1558 if (returnsha1)
1559 hashcpy(returnsha1, sha1);
1560 if (has_sha1_file(sha1))
1561 return 0;
1562 fd = open(filename, O_RDONLY);
1563 if (fd >= 0) {
1564 /*
1565 * FIXME!!! We might do collision checking here, but we'd
1566 * need to uncompress the old file and check it. Later.
1567 */
1568 close(fd);
1569 return 0;
1570 }
1571
1572 if (errno != ENOENT) {
1573 return error("sha1 file %s: %s\n", filename, strerror(errno));
1574 }
1575
1576 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1577
1578 fd = mkstemp(tmpfile);
1579 if (fd < 0) {
1580 if (errno == EPERM)
1581 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1582 else
1583 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1584 }
1585
1586 /* Set it up */
1587 memset(&stream, 0, sizeof(stream));
1588 deflateInit(&stream, zlib_compression_level);
1589 size = 8 + deflateBound(&stream, len+hdrlen);
1590 compressed = xmalloc(size);
1591
1592 /* Compress it */
1593 stream.next_out = compressed;
1594 stream.avail_out = size;
1595
1596 /* First header.. */
1597 stream.next_in = hdr;
1598 stream.avail_in = hdrlen;
1599 setup_object_header(&stream, type, len);
1600
1601 /* Then the data itself.. */
1602 stream.next_in = buf;
1603 stream.avail_in = len;
1604 while (deflate(&stream, Z_FINISH) == Z_OK)
1605 /* nothing */;
1606 deflateEnd(&stream);
1607 size = stream.total_out;
1608
1609 if (write_buffer(fd, compressed, size) < 0)
1610 die("unable to write sha1 file");
1611 fchmod(fd, 0444);
1612 close(fd);
1613 free(compressed);
1614
1615 return move_temp_to_file(tmpfile, filename);
1616 }
1617
1618 /*
1619 * We need to unpack and recompress the object for writing
1620 * it out to a different file.
1621 */
1622 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1623 {
1624 size_t size;
1625 z_stream stream;
1626 unsigned char *unpacked;
1627 unsigned long len;
1628 char type[20];
1629 char hdr[50];
1630 int hdrlen;
1631 void *buf;
1632
1633 /* need to unpack and recompress it by itself */
1634 unpacked = read_packed_sha1(sha1, type, &len);
1635
1636 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1637
1638 /* Set it up */
1639 memset(&stream, 0, sizeof(stream));
1640 deflateInit(&stream, zlib_compression_level);
1641 size = deflateBound(&stream, len + hdrlen);
1642 buf = xmalloc(size);
1643
1644 /* Compress it */
1645 stream.next_out = buf;
1646 stream.avail_out = size;
1647
1648 /* First header.. */
1649 stream.next_in = (void *)hdr;
1650 stream.avail_in = hdrlen;
1651 while (deflate(&stream, 0) == Z_OK)
1652 /* nothing */;
1653
1654 /* Then the data itself.. */
1655 stream.next_in = unpacked;
1656 stream.avail_in = len;
1657 while (deflate(&stream, Z_FINISH) == Z_OK)
1658 /* nothing */;
1659 deflateEnd(&stream);
1660 free(unpacked);
1661
1662 *objsize = stream.total_out;
1663 return buf;
1664 }
1665
1666 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1667 {
1668 int retval;
1669 unsigned long objsize;
1670 void *buf = map_sha1_file(sha1, &objsize);
1671
1672 if (buf) {
1673 retval = write_buffer(fd, buf, objsize);
1674 munmap(buf, objsize);
1675 return retval;
1676 }
1677
1678 buf = repack_object(sha1, &objsize);
1679 retval = write_buffer(fd, buf, objsize);
1680 free(buf);
1681 return retval;
1682 }
1683
1684 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1685 size_t bufsize, size_t *bufposn)
1686 {
1687 char tmpfile[PATH_MAX];
1688 int local;
1689 z_stream stream;
1690 unsigned char real_sha1[20];
1691 unsigned char discard[4096];
1692 int ret;
1693 SHA_CTX c;
1694
1695 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1696
1697 local = mkstemp(tmpfile);
1698 if (local < 0) {
1699 if (errno == EPERM)
1700 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1701 else
1702 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1703 }
1704
1705 memset(&stream, 0, sizeof(stream));
1706
1707 inflateInit(&stream);
1708
1709 SHA1_Init(&c);
1710
1711 do {
1712 ssize_t size;
1713 if (*bufposn) {
1714 stream.avail_in = *bufposn;
1715 stream.next_in = (unsigned char *) buffer;
1716 do {
1717 stream.next_out = discard;
1718 stream.avail_out = sizeof(discard);
1719 ret = inflate(&stream, Z_SYNC_FLUSH);
1720 SHA1_Update(&c, discard, sizeof(discard) -
1721 stream.avail_out);
1722 } while (stream.avail_in && ret == Z_OK);
1723 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1724 die("unable to write sha1 file");
1725 memmove(buffer, buffer + *bufposn - stream.avail_in,
1726 stream.avail_in);
1727 *bufposn = stream.avail_in;
1728 if (ret != Z_OK)
1729 break;
1730 }
1731 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1732 if (size <= 0) {
1733 close(local);
1734 unlink(tmpfile);
1735 if (!size)
1736 return error("Connection closed?");
1737 perror("Reading from connection");
1738 return -1;
1739 }
1740 *bufposn += size;
1741 } while (1);
1742 inflateEnd(&stream);
1743
1744 close(local);
1745 SHA1_Final(real_sha1, &c);
1746 if (ret != Z_STREAM_END) {
1747 unlink(tmpfile);
1748 return error("File %s corrupted", sha1_to_hex(sha1));
1749 }
1750 if (hashcmp(sha1, real_sha1)) {
1751 unlink(tmpfile);
1752 return error("File %s has bad hash", sha1_to_hex(sha1));
1753 }
1754
1755 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1756 }
1757
1758 int has_pack_index(const unsigned char *sha1)
1759 {
1760 struct stat st;
1761 if (stat(sha1_pack_index_name(sha1), &st))
1762 return 0;
1763 return 1;
1764 }
1765
1766 int has_pack_file(const unsigned char *sha1)
1767 {
1768 struct stat st;
1769 if (stat(sha1_pack_name(sha1), &st))
1770 return 0;
1771 return 1;
1772 }
1773
1774 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1775 {
1776 struct pack_entry e;
1777 return find_pack_entry(sha1, &e, ignore_packed);
1778 }
1779
1780 int has_sha1_file(const unsigned char *sha1)
1781 {
1782 struct stat st;
1783 struct pack_entry e;
1784
1785 if (find_pack_entry(sha1, &e, NULL))
1786 return 1;
1787 return find_sha1_file(sha1, &st) ? 1 : 0;
1788 }
1789
1790 /*
1791 * reads from fd as long as possible into a supplied buffer of size bytes.
1792 * If necessary the buffer's size is increased using realloc()
1793 *
1794 * returns 0 if anything went fine and -1 otherwise
1795 *
1796 * NOTE: both buf and size may change, but even when -1 is returned
1797 * you still have to free() it yourself.
1798 */
1799 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1800 {
1801 char* buf = *return_buf;
1802 unsigned long size = *return_size;
1803 int iret;
1804 unsigned long off = 0;
1805
1806 do {
1807 iret = xread(fd, buf + off, size - off);
1808 if (iret > 0) {
1809 off += iret;
1810 if (off == size) {
1811 size *= 2;
1812 buf = xrealloc(buf, size);
1813 }
1814 }
1815 } while (iret > 0);
1816
1817 *return_buf = buf;
1818 *return_size = off;
1819
1820 if (iret < 0)
1821 return -1;
1822 return 0;
1823 }
1824
1825 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1826 {
1827 unsigned long size = 4096;
1828 char *buf = xmalloc(size);
1829 int ret;
1830
1831 if (read_pipe(fd, &buf, &size)) {
1832 free(buf);
1833 return -1;
1834 }
1835
1836 if (!type)
1837 type = blob_type;
1838 if (write_object)
1839 ret = write_sha1_file(buf, size, type, sha1);
1840 else
1841 ret = hash_sha1_file(buf, size, type, sha1);
1842 free(buf);
1843 return ret;
1844 }
1845
1846 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1847 {
1848 unsigned long size = st->st_size;
1849 void *buf;
1850 int ret;
1851
1852 buf = "";
1853 if (size)
1854 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1855 close(fd);
1856 if (buf == MAP_FAILED)
1857 return -1;
1858
1859 if (!type)
1860 type = blob_type;
1861 if (write_object)
1862 ret = write_sha1_file(buf, size, type, sha1);
1863 else
1864 ret = hash_sha1_file(buf, size, type, sha1);
1865 if (size)
1866 munmap(buf, size);
1867 return ret;
1868 }
1869
1870 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1871 {
1872 int fd;
1873 char *target;
1874
1875 switch (st->st_mode & S_IFMT) {
1876 case S_IFREG:
1877 fd = open(path, O_RDONLY);
1878 if (fd < 0)
1879 return error("open(\"%s\"): %s", path,
1880 strerror(errno));
1881 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1882 return error("%s: failed to insert into database",
1883 path);
1884 break;
1885 case S_IFLNK:
1886 target = xmalloc(st->st_size+1);
1887 if (readlink(path, target, st->st_size+1) != st->st_size) {
1888 char *errstr = strerror(errno);
1889 free(target);
1890 return error("readlink(\"%s\"): %s", path,
1891 errstr);
1892 }
1893 if (!write_object)
1894 hash_sha1_file(target, st->st_size, blob_type, sha1);
1895 else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1896 return error("%s: failed to insert into database",
1897 path);
1898 free(target);
1899 break;
1900 default:
1901 return error("%s: unsupported file type", path);
1902 }
1903 return 0;
1904 }