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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"
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
25 const unsigned char null_sha1[20];
27 static unsigned int sha1_file_open_flag = O_NOATIME;
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 };
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 }
77 int safe_create_leading_directories(char *path)
78 {
79 char *pos = path;
80 struct stat st;
82 if (*pos == '/')
83 pos++;
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 }
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;
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';
125 return buffer;
126 }
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 }
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;
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 }
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;
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 }
182 buf = name;
184 for (i = 0; i < 20; i++) {
185 unsigned int val = *sha1++;
186 *buf++ = hex[val >> 4];
187 *buf++ = hex[val & 0xf];
188 }
190 return base;
191 }
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;
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 }
207 buf = name;
209 for (i = 0; i < 20; i++) {
210 unsigned int val = *sha1++;
211 *buf++ = hex[val >> 4];
212 *buf++ = hex[val & 0xf];
213 }
215 return base;
216 }
218 struct alternate_object_database *alt_odb_list;
219 static struct alternate_object_database **alt_odb_tail;
221 static void read_info_alternates(const char * alternates, int depth);
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;
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);
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);
266 ent->name = ent->base + pfxlen + 1;
267 ent->base[pfxlen + 3] = '/';
268 ent->base[pfxlen] = ent->base[entlen-1] = 0;
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 }
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 }
293 /* add the alternate entry */
294 *alt_odb_tail = ent;
295 alt_odb_tail = &(ent->next);
296 ent->next = NULL;
298 /* recursively add alternates */
299 read_info_alternates(ent->base, depth + 1);
301 ent->base[pfxlen] = '/';
303 return 0;
304 }
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;
311 if (depth > 5) {
312 error("%s: ignoring alternate object stores, nesting too deep.",
313 relative_base);
314 return;
315 }
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 }
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;
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;
363 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
365 munmap(map, st.st_size);
366 }
368 void prepare_alt_odb(void)
369 {
370 const char *alt;
372 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
373 if (!alt) alt = "";
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);
380 read_info_alternates(get_object_directory(), 0);
381 }
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;
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 }
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;
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;
426 index = idx_map;
427 *idx_map_ = idx_map;
428 *idx_size_ = idx_size;
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 }
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");
451 return 0;
452 }
454 static int unuse_one_packed_git(void)
455 {
456 struct packed_git *p, *lru = NULL;
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 }
471 void unuse_packed_git(struct packed_git *p)
472 {
473 p->pack_use_cnt--;
474 }
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;
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;
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));
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 }
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];
544 if (check_packed_git_idx(path, &idx_size, &idx_map))
545 return NULL;
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 }
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 }
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;
584 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
585 return NULL;
587 path = sha1_pack_name(sha1);
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 }
602 void install_packed_git(struct packed_git *pack)
603 {
604 pack->next = packed_git;
605 packed_git = pack;
606 }
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;
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;
629 if (!has_extension(de->d_name, ".idx"))
630 continue;
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 }
649 static int prepare_packed_git_run_once = 0;
650 void prepare_packed_git(void)
651 {
652 struct alternate_object_database *alt;
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 }
666 static void reprepare_packed_git(void)
667 {
668 prepare_packed_git_run_once = 0;
669 prepare_packed_git();
670 }
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;
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 }
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);
692 if (!filename) {
693 return NULL;
694 }
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 }
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 }
722 int legacy_loose_object(unsigned char *map)
723 {
724 unsigned int word;
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 }
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;
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 }
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;
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;
779 if (legacy_loose_object(map)) {
780 inflateInit(stream);
781 return inflate(stream, 0);
782 }
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;
790 /* Set up the stream for the rest.. */
791 stream->next_in = map;
792 stream->avail_in = mapsize;
793 inflateInit(stream);
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 }
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;
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 }
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;
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;
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;
867 /*
868 * The length must be followed by a zero byte
869 */
870 return *hdr ? -1 : 0;
871 }
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];
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;
883 return unpack_sha1_rest(&stream, hdr, *size);
884 }
886 static unsigned long get_delta_base(struct packed_git *p,
887 unsigned long offset,
888 enum object_type kind,
889 unsigned long delta_obj_offset,
890 unsigned long *base_obj_offset)
891 {
892 unsigned char *base_info = (unsigned char *) p->pack_base + offset;
893 unsigned long base_offset;
895 /* there must be at least 20 bytes left regardless of delta type */
896 if (p->pack_size <= offset + 20)
897 die("truncated pack file");
899 if (kind == OBJ_OFS_DELTA) {
900 unsigned used = 0;
901 unsigned char c = base_info[used++];
902 base_offset = c & 127;
903 while (c & 128) {
904 base_offset += 1;
905 if (!base_offset || base_offset & ~(~0UL >> 7))
906 die("offset value overflow for delta base object");
907 c = base_info[used++];
908 base_offset = (base_offset << 7) + (c & 127);
909 }
910 base_offset = delta_obj_offset - base_offset;
911 if (base_offset >= delta_obj_offset)
912 die("delta base offset out of bound");
913 offset += used;
914 } else if (kind == OBJ_REF_DELTA) {
915 /* The base entry _must_ be in the same pack */
916 base_offset = find_pack_entry_one(base_info, p);
917 if (!base_offset)
918 die("failed to find delta-pack base object %s",
919 sha1_to_hex(base_info));
920 offset += 20;
921 } else
922 die("I am totally screwed");
923 *base_obj_offset = base_offset;
924 return offset;
925 }
927 /* forward declaration for a mutually recursive function */
928 static int packed_object_info(struct packed_git *p, unsigned long offset,
929 char *type, unsigned long *sizep);
931 static int packed_delta_info(struct packed_git *p,
932 unsigned long offset,
933 enum object_type kind,
934 unsigned long obj_offset,
935 char *type,
936 unsigned long *sizep)
937 {
938 unsigned long base_offset;
940 offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
942 /* We choose to only get the type of the base object and
943 * ignore potentially corrupt pack file that expects the delta
944 * based on a base with a wrong size. This saves tons of
945 * inflate() calls.
946 */
947 if (packed_object_info(p, base_offset, type, NULL))
948 die("cannot get info for delta-pack base");
950 if (sizep) {
951 const unsigned char *data;
952 unsigned char delta_head[64];
953 unsigned long result_size;
954 z_stream stream;
955 int st;
957 memset(&stream, 0, sizeof(stream));
959 stream.next_in = (unsigned char *) p->pack_base + offset;
960 stream.avail_in = p->pack_size - offset;
961 stream.next_out = delta_head;
962 stream.avail_out = sizeof(delta_head);
964 inflateInit(&stream);
965 st = inflate(&stream, Z_FINISH);
966 inflateEnd(&stream);
967 if ((st != Z_STREAM_END) &&
968 stream.total_out != sizeof(delta_head))
969 die("delta data unpack-initial failed");
971 /* Examine the initial part of the delta to figure out
972 * the result size.
973 */
974 data = delta_head;
976 /* ignore base size */
977 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
979 /* Read the result size */
980 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
981 *sizep = result_size;
982 }
983 return 0;
984 }
986 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
987 enum object_type *type, unsigned long *sizep)
988 {
989 unsigned long used;
991 if (p->pack_size <= offset)
992 die("object offset outside of pack file");
994 used = unpack_object_header_gently((unsigned char *)p->pack_base +
995 offset,
996 p->pack_size - offset, type, sizep);
997 if (!used)
998 die("object offset outside of pack file");
1000 return offset + used;
1001 }
1003 void packed_object_info_detail(struct packed_git *p,
1004 unsigned long offset,
1005 char *type,
1006 unsigned long *size,
1007 unsigned long *store_size,
1008 unsigned int *delta_chain_length,
1009 unsigned char *base_sha1)
1010 {
1011 unsigned long obj_offset, val;
1012 unsigned char *next_sha1;
1013 enum object_type kind;
1015 *delta_chain_length = 0;
1016 obj_offset = offset;
1017 offset = unpack_object_header(p, offset, &kind, size);
1019 for (;;) {
1020 switch (kind) {
1021 default:
1022 die("corrupted pack file %s containing object of kind %d",
1023 p->pack_name, kind);
1024 case OBJ_COMMIT:
1025 case OBJ_TREE:
1026 case OBJ_BLOB:
1027 case OBJ_TAG:
1028 strcpy(type, type_names[kind]);
1029 *store_size = 0; /* notyet */
1030 return;
1031 case OBJ_OFS_DELTA:
1032 get_delta_base(p, offset, kind, obj_offset, &offset);
1033 if (*delta_chain_length == 0) {
1034 /* TODO: find base_sha1 as pointed by offset */
1035 }
1036 break;
1037 case OBJ_REF_DELTA:
1038 if (p->pack_size <= offset + 20)
1039 die("pack file %s records an incomplete delta base",
1040 p->pack_name);
1041 next_sha1 = (unsigned char *) p->pack_base + offset;
1042 if (*delta_chain_length == 0)
1043 hashcpy(base_sha1, next_sha1);
1044 offset = find_pack_entry_one(next_sha1, p);
1045 break;
1046 }
1047 obj_offset = offset;
1048 offset = unpack_object_header(p, offset, &kind, &val);
1049 (*delta_chain_length)++;
1050 }
1051 }
1053 static int packed_object_info(struct packed_git *p, unsigned long offset,
1054 char *type, unsigned long *sizep)
1055 {
1056 unsigned long size, obj_offset = offset;
1057 enum object_type kind;
1059 offset = unpack_object_header(p, offset, &kind, &size);
1061 switch (kind) {
1062 case OBJ_OFS_DELTA:
1063 case OBJ_REF_DELTA:
1064 return packed_delta_info(p, offset, kind, obj_offset, type, sizep);
1065 case OBJ_COMMIT:
1066 case OBJ_TREE:
1067 case OBJ_BLOB:
1068 case OBJ_TAG:
1069 strcpy(type, type_names[kind]);
1070 break;
1071 default:
1072 die("corrupted pack file %s containing object of kind %d",
1073 p->pack_name, kind);
1074 }
1075 if (sizep)
1076 *sizep = size;
1077 return 0;
1078 }
1080 static void *unpack_compressed_entry(struct packed_git *p,
1081 unsigned long offset,
1082 unsigned long size)
1083 {
1084 int st;
1085 z_stream stream;
1086 unsigned char *buffer;
1088 buffer = xmalloc(size + 1);
1089 buffer[size] = 0;
1090 memset(&stream, 0, sizeof(stream));
1091 stream.next_in = (unsigned char*)p->pack_base + offset;
1092 stream.avail_in = p->pack_size - offset;
1093 stream.next_out = buffer;
1094 stream.avail_out = size;
1096 inflateInit(&stream);
1097 st = inflate(&stream, Z_FINISH);
1098 inflateEnd(&stream);
1099 if ((st != Z_STREAM_END) || stream.total_out != size) {
1100 free(buffer);
1101 return NULL;
1102 }
1104 return buffer;
1105 }
1107 static void *unpack_delta_entry(struct packed_git *p,
1108 unsigned long offset,
1109 unsigned long delta_size,
1110 enum object_type kind,
1111 unsigned long obj_offset,
1112 char *type,
1113 unsigned long *sizep)
1114 {
1115 void *delta_data, *result, *base;
1116 unsigned long result_size, base_size, base_offset;
1118 offset = get_delta_base(p, offset, kind, obj_offset, &base_offset);
1119 base = unpack_entry_gently(p, base_offset, type, &base_size);
1120 if (!base)
1121 die("failed to read delta base object at %lu from %s",
1122 base_offset, p->pack_name);
1124 delta_data = unpack_compressed_entry(p, offset, delta_size);
1125 result = patch_delta(base, base_size,
1126 delta_data, delta_size,
1127 &result_size);
1128 if (!result)
1129 die("failed to apply delta");
1130 free(delta_data);
1131 free(base);
1132 *sizep = result_size;
1133 return result;
1134 }
1136 static void *unpack_entry(struct pack_entry *entry,
1137 char *type, unsigned long *sizep)
1138 {
1139 struct packed_git *p = entry->p;
1140 void *retval;
1142 if (use_packed_git(p))
1143 die("cannot map packed file");
1144 retval = unpack_entry_gently(p, entry->offset, type, sizep);
1145 unuse_packed_git(p);
1146 if (!retval)
1147 die("corrupted pack file %s", p->pack_name);
1148 return retval;
1149 }
1151 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1152 void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
1153 char *type, unsigned long *sizep)
1154 {
1155 unsigned long size, obj_offset = offset;
1156 enum object_type kind;
1158 offset = unpack_object_header(p, offset, &kind, &size);
1159 switch (kind) {
1160 case OBJ_OFS_DELTA:
1161 case OBJ_REF_DELTA:
1162 return unpack_delta_entry(p, offset, size, kind, obj_offset, type, sizep);
1163 case OBJ_COMMIT:
1164 case OBJ_TREE:
1165 case OBJ_BLOB:
1166 case OBJ_TAG:
1167 strcpy(type, type_names[kind]);
1168 *sizep = size;
1169 return unpack_compressed_entry(p, offset, size);
1170 default:
1171 return NULL;
1172 }
1173 }
1175 int num_packed_objects(const struct packed_git *p)
1176 {
1177 /* See check_packed_git_idx() */
1178 return (p->index_size - 20 - 20 - 4*256) / 24;
1179 }
1181 int nth_packed_object_sha1(const struct packed_git *p, int n,
1182 unsigned char* sha1)
1183 {
1184 void *index = p->index_base + 256;
1185 if (n < 0 || num_packed_objects(p) <= n)
1186 return -1;
1187 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1188 return 0;
1189 }
1191 unsigned long find_pack_entry_one(const unsigned char *sha1,
1192 struct packed_git *p)
1193 {
1194 unsigned int *level1_ofs = p->index_base;
1195 int hi = ntohl(level1_ofs[*sha1]);
1196 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1197 void *index = p->index_base + 256;
1199 do {
1200 int mi = (lo + hi) / 2;
1201 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1202 if (!cmp)
1203 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1204 if (cmp > 0)
1205 hi = mi;
1206 else
1207 lo = mi+1;
1208 } while (lo < hi);
1209 return 0;
1210 }
1212 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1213 {
1214 struct packed_git *p;
1215 unsigned long offset;
1217 prepare_packed_git();
1219 for (p = packed_git; p; p = p->next) {
1220 if (ignore_packed) {
1221 const char **ig;
1222 for (ig = ignore_packed; *ig; ig++)
1223 if (!strcmp(p->pack_name, *ig))
1224 break;
1225 if (*ig)
1226 continue;
1227 }
1228 offset = find_pack_entry_one(sha1, p);
1229 if (offset) {
1230 e->offset = offset;
1231 e->p = p;
1232 hashcpy(e->sha1, sha1);
1233 return 1;
1234 }
1235 }
1236 return 0;
1237 }
1239 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1240 struct packed_git *packs)
1241 {
1242 struct packed_git *p;
1244 for (p = packs; p; p = p->next) {
1245 if (find_pack_entry_one(sha1, p))
1246 return p;
1247 }
1248 return NULL;
1250 }
1252 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1253 {
1254 int status;
1255 unsigned long mapsize, size;
1256 void *map;
1257 z_stream stream;
1258 char hdr[128];
1260 map = map_sha1_file(sha1, &mapsize);
1261 if (!map) {
1262 struct pack_entry e;
1264 if (!find_pack_entry(sha1, &e, NULL)) {
1265 reprepare_packed_git();
1266 if (!find_pack_entry(sha1, &e, NULL))
1267 return error("unable to find %s", sha1_to_hex(sha1));
1268 }
1269 if (use_packed_git(e.p))
1270 die("cannot map packed file");
1271 status = packed_object_info(e.p, e.offset, type, sizep);
1272 unuse_packed_git(e.p);
1273 return status;
1274 }
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 }
1290 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1291 {
1292 struct pack_entry e;
1294 if (!find_pack_entry(sha1, &e, NULL)) {
1295 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1296 return NULL;
1297 }
1298 return unpack_entry(&e, type, size);
1299 }
1301 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1302 {
1303 unsigned long mapsize;
1304 void *map, *buf;
1305 struct pack_entry e;
1307 if (find_pack_entry(sha1, &e, NULL))
1308 return read_packed_sha1(sha1, type, size);
1309 map = map_sha1_file(sha1, &mapsize);
1310 if (map) {
1311 buf = unpack_sha1_file(map, mapsize, type, size);
1312 munmap(map, mapsize);
1313 return buf;
1314 }
1315 reprepare_packed_git();
1316 if (find_pack_entry(sha1, &e, NULL))
1317 return read_packed_sha1(sha1, type, size);
1318 return NULL;
1319 }
1321 void *read_object_with_reference(const unsigned char *sha1,
1322 const char *required_type,
1323 unsigned long *size,
1324 unsigned char *actual_sha1_return)
1325 {
1326 char type[20];
1327 void *buffer;
1328 unsigned long isize;
1329 unsigned char actual_sha1[20];
1331 hashcpy(actual_sha1, sha1);
1332 while (1) {
1333 int ref_length = -1;
1334 const char *ref_type = NULL;
1336 buffer = read_sha1_file(actual_sha1, type, &isize);
1337 if (!buffer)
1338 return NULL;
1339 if (!strcmp(type, required_type)) {
1340 *size = isize;
1341 if (actual_sha1_return)
1342 hashcpy(actual_sha1_return, actual_sha1);
1343 return buffer;
1344 }
1345 /* Handle references */
1346 else if (!strcmp(type, commit_type))
1347 ref_type = "tree ";
1348 else if (!strcmp(type, tag_type))
1349 ref_type = "object ";
1350 else {
1351 free(buffer);
1352 return NULL;
1353 }
1354 ref_length = strlen(ref_type);
1356 if (memcmp(buffer, ref_type, ref_length) ||
1357 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1358 free(buffer);
1359 return NULL;
1360 }
1361 free(buffer);
1362 /* Now we have the ID of the referred-to object in
1363 * actual_sha1. Check again. */
1364 }
1365 }
1367 char *write_sha1_file_prepare(void *buf,
1368 unsigned long len,
1369 const char *type,
1370 unsigned char *sha1,
1371 unsigned char *hdr,
1372 int *hdrlen)
1373 {
1374 SHA_CTX c;
1376 /* Generate the header */
1377 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1379 /* Sha1.. */
1380 SHA1_Init(&c);
1381 SHA1_Update(&c, hdr, *hdrlen);
1382 SHA1_Update(&c, buf, len);
1383 SHA1_Final(sha1, &c);
1385 return sha1_file_name(sha1);
1386 }
1388 /*
1389 * Link the tempfile to the final place, possibly creating the
1390 * last directory level as you do so.
1391 *
1392 * Returns the errno on failure, 0 on success.
1393 */
1394 static int link_temp_to_file(const char *tmpfile, const char *filename)
1395 {
1396 int ret;
1397 char *dir;
1399 if (!link(tmpfile, filename))
1400 return 0;
1402 /*
1403 * Try to mkdir the last path component if that failed.
1404 *
1405 * Re-try the "link()" regardless of whether the mkdir
1406 * succeeds, since a race might mean that somebody
1407 * else succeeded.
1408 */
1409 ret = errno;
1410 dir = strrchr(filename, '/');
1411 if (dir) {
1412 *dir = 0;
1413 mkdir(filename, 0777);
1414 if (adjust_shared_perm(filename))
1415 return -2;
1416 *dir = '/';
1417 if (!link(tmpfile, filename))
1418 return 0;
1419 ret = errno;
1420 }
1421 return ret;
1422 }
1424 /*
1425 * Move the just written object into its final resting place
1426 */
1427 int move_temp_to_file(const char *tmpfile, const char *filename)
1428 {
1429 int ret = link_temp_to_file(tmpfile, filename);
1431 /*
1432 * Coda hack - coda doesn't like cross-directory links,
1433 * so we fall back to a rename, which will mean that it
1434 * won't be able to check collisions, but that's not a
1435 * big deal.
1436 *
1437 * The same holds for FAT formatted media.
1438 *
1439 * When this succeeds, we just return 0. We have nothing
1440 * left to unlink.
1441 */
1442 if (ret && ret != EEXIST) {
1443 if (!rename(tmpfile, filename))
1444 return 0;
1445 ret = errno;
1446 }
1447 unlink(tmpfile);
1448 if (ret) {
1449 if (ret != EEXIST) {
1450 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1451 return -1;
1452 }
1453 /* FIXME!!! Collision check here ? */
1454 }
1456 return 0;
1457 }
1459 static int write_buffer(int fd, const void *buf, size_t len)
1460 {
1461 while (len) {
1462 ssize_t size;
1464 size = write(fd, buf, len);
1465 if (!size)
1466 return error("file write: disk full");
1467 if (size < 0) {
1468 if (errno == EINTR || errno == EAGAIN)
1469 continue;
1470 return error("file write error (%s)", strerror(errno));
1471 }
1472 len -= size;
1473 buf = (char *) buf + size;
1474 }
1475 return 0;
1476 }
1478 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1479 {
1480 int hdr_len;
1481 unsigned char c;
1483 c = (type << 4) | (len & 15);
1484 len >>= 4;
1485 hdr_len = 1;
1486 while (len) {
1487 *hdr++ = c | 0x80;
1488 hdr_len++;
1489 c = (len & 0x7f);
1490 len >>= 7;
1491 }
1492 *hdr = c;
1493 return hdr_len;
1494 }
1496 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1497 {
1498 int obj_type, hdr;
1500 if (use_legacy_headers) {
1501 while (deflate(stream, 0) == Z_OK)
1502 /* nothing */;
1503 return;
1504 }
1505 if (!strcmp(type, blob_type))
1506 obj_type = OBJ_BLOB;
1507 else if (!strcmp(type, tree_type))
1508 obj_type = OBJ_TREE;
1509 else if (!strcmp(type, commit_type))
1510 obj_type = OBJ_COMMIT;
1511 else if (!strcmp(type, tag_type))
1512 obj_type = OBJ_TAG;
1513 else
1514 die("trying to generate bogus object of type '%s'", type);
1515 hdr = write_binary_header(stream->next_out, obj_type, len);
1516 stream->total_out = hdr;
1517 stream->next_out += hdr;
1518 stream->avail_out -= hdr;
1519 }
1521 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1522 {
1523 int size;
1524 unsigned char *compressed;
1525 z_stream stream;
1526 unsigned char sha1[20];
1527 char *filename;
1528 static char tmpfile[PATH_MAX];
1529 unsigned char hdr[50];
1530 int fd, hdrlen;
1532 /* Normally if we have it in the pack then we do not bother writing
1533 * it out into .git/objects/??/?{38} file.
1534 */
1535 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1536 if (returnsha1)
1537 hashcpy(returnsha1, sha1);
1538 if (has_sha1_file(sha1))
1539 return 0;
1540 fd = open(filename, O_RDONLY);
1541 if (fd >= 0) {
1542 /*
1543 * FIXME!!! We might do collision checking here, but we'd
1544 * need to uncompress the old file and check it. Later.
1545 */
1546 close(fd);
1547 return 0;
1548 }
1550 if (errno != ENOENT) {
1551 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1552 return -1;
1553 }
1555 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1557 fd = mkstemp(tmpfile);
1558 if (fd < 0) {
1559 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1560 return -1;
1561 }
1563 /* Set it up */
1564 memset(&stream, 0, sizeof(stream));
1565 deflateInit(&stream, zlib_compression_level);
1566 size = 8 + deflateBound(&stream, len+hdrlen);
1567 compressed = xmalloc(size);
1569 /* Compress it */
1570 stream.next_out = compressed;
1571 stream.avail_out = size;
1573 /* First header.. */
1574 stream.next_in = hdr;
1575 stream.avail_in = hdrlen;
1576 setup_object_header(&stream, type, len);
1578 /* Then the data itself.. */
1579 stream.next_in = buf;
1580 stream.avail_in = len;
1581 while (deflate(&stream, Z_FINISH) == Z_OK)
1582 /* nothing */;
1583 deflateEnd(&stream);
1584 size = stream.total_out;
1586 if (write_buffer(fd, compressed, size) < 0)
1587 die("unable to write sha1 file");
1588 fchmod(fd, 0444);
1589 close(fd);
1590 free(compressed);
1592 return move_temp_to_file(tmpfile, filename);
1593 }
1595 /*
1596 * We need to unpack and recompress the object for writing
1597 * it out to a different file.
1598 */
1599 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1600 {
1601 size_t size;
1602 z_stream stream;
1603 unsigned char *unpacked;
1604 unsigned long len;
1605 char type[20];
1606 char hdr[50];
1607 int hdrlen;
1608 void *buf;
1610 /* need to unpack and recompress it by itself */
1611 unpacked = read_packed_sha1(sha1, type, &len);
1613 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1615 /* Set it up */
1616 memset(&stream, 0, sizeof(stream));
1617 deflateInit(&stream, zlib_compression_level);
1618 size = deflateBound(&stream, len + hdrlen);
1619 buf = xmalloc(size);
1621 /* Compress it */
1622 stream.next_out = buf;
1623 stream.avail_out = size;
1625 /* First header.. */
1626 stream.next_in = (void *)hdr;
1627 stream.avail_in = hdrlen;
1628 while (deflate(&stream, 0) == Z_OK)
1629 /* nothing */;
1631 /* Then the data itself.. */
1632 stream.next_in = unpacked;
1633 stream.avail_in = len;
1634 while (deflate(&stream, Z_FINISH) == Z_OK)
1635 /* nothing */;
1636 deflateEnd(&stream);
1637 free(unpacked);
1639 *objsize = stream.total_out;
1640 return buf;
1641 }
1643 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1644 {
1645 int retval;
1646 unsigned long objsize;
1647 void *buf = map_sha1_file(sha1, &objsize);
1649 if (buf) {
1650 retval = write_buffer(fd, buf, objsize);
1651 munmap(buf, objsize);
1652 return retval;
1653 }
1655 buf = repack_object(sha1, &objsize);
1656 retval = write_buffer(fd, buf, objsize);
1657 free(buf);
1658 return retval;
1659 }
1661 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1662 size_t bufsize, size_t *bufposn)
1663 {
1664 char tmpfile[PATH_MAX];
1665 int local;
1666 z_stream stream;
1667 unsigned char real_sha1[20];
1668 unsigned char discard[4096];
1669 int ret;
1670 SHA_CTX c;
1672 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1674 local = mkstemp(tmpfile);
1675 if (local < 0)
1676 return error("Couldn't open %s for %s",
1677 tmpfile, sha1_to_hex(sha1));
1679 memset(&stream, 0, sizeof(stream));
1681 inflateInit(&stream);
1683 SHA1_Init(&c);
1685 do {
1686 ssize_t size;
1687 if (*bufposn) {
1688 stream.avail_in = *bufposn;
1689 stream.next_in = (unsigned char *) buffer;
1690 do {
1691 stream.next_out = discard;
1692 stream.avail_out = sizeof(discard);
1693 ret = inflate(&stream, Z_SYNC_FLUSH);
1694 SHA1_Update(&c, discard, sizeof(discard) -
1695 stream.avail_out);
1696 } while (stream.avail_in && ret == Z_OK);
1697 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1698 die("unable to write sha1 file");
1699 memmove(buffer, buffer + *bufposn - stream.avail_in,
1700 stream.avail_in);
1701 *bufposn = stream.avail_in;
1702 if (ret != Z_OK)
1703 break;
1704 }
1705 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1706 if (size <= 0) {
1707 close(local);
1708 unlink(tmpfile);
1709 if (!size)
1710 return error("Connection closed?");
1711 perror("Reading from connection");
1712 return -1;
1713 }
1714 *bufposn += size;
1715 } while (1);
1716 inflateEnd(&stream);
1718 close(local);
1719 SHA1_Final(real_sha1, &c);
1720 if (ret != Z_STREAM_END) {
1721 unlink(tmpfile);
1722 return error("File %s corrupted", sha1_to_hex(sha1));
1723 }
1724 if (hashcmp(sha1, real_sha1)) {
1725 unlink(tmpfile);
1726 return error("File %s has bad hash", sha1_to_hex(sha1));
1727 }
1729 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1730 }
1732 int has_pack_index(const unsigned char *sha1)
1733 {
1734 struct stat st;
1735 if (stat(sha1_pack_index_name(sha1), &st))
1736 return 0;
1737 return 1;
1738 }
1740 int has_pack_file(const unsigned char *sha1)
1741 {
1742 struct stat st;
1743 if (stat(sha1_pack_name(sha1), &st))
1744 return 0;
1745 return 1;
1746 }
1748 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1749 {
1750 struct pack_entry e;
1751 return find_pack_entry(sha1, &e, ignore_packed);
1752 }
1754 int has_sha1_file(const unsigned char *sha1)
1755 {
1756 struct stat st;
1757 struct pack_entry e;
1759 if (find_pack_entry(sha1, &e, NULL))
1760 return 1;
1761 return find_sha1_file(sha1, &st) ? 1 : 0;
1762 }
1764 /*
1765 * reads from fd as long as possible into a supplied buffer of size bytes.
1766 * If necessary the buffer's size is increased using realloc()
1767 *
1768 * returns 0 if anything went fine and -1 otherwise
1769 *
1770 * NOTE: both buf and size may change, but even when -1 is returned
1771 * you still have to free() it yourself.
1772 */
1773 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1774 {
1775 char* buf = *return_buf;
1776 unsigned long size = *return_size;
1777 int iret;
1778 unsigned long off = 0;
1780 do {
1781 iret = xread(fd, buf + off, size - off);
1782 if (iret > 0) {
1783 off += iret;
1784 if (off == size) {
1785 size *= 2;
1786 buf = xrealloc(buf, size);
1787 }
1788 }
1789 } while (iret > 0);
1791 *return_buf = buf;
1792 *return_size = off;
1794 if (iret < 0)
1795 return -1;
1796 return 0;
1797 }
1799 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1800 {
1801 unsigned long size = 4096;
1802 char *buf = xmalloc(size);
1803 int ret;
1804 unsigned char hdr[50];
1805 int hdrlen;
1807 if (read_pipe(fd, &buf, &size)) {
1808 free(buf);
1809 return -1;
1810 }
1812 if (!type)
1813 type = blob_type;
1814 if (write_object)
1815 ret = write_sha1_file(buf, size, type, sha1);
1816 else {
1817 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1818 ret = 0;
1819 }
1820 free(buf);
1821 return ret;
1822 }
1824 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1825 {
1826 unsigned long size = st->st_size;
1827 void *buf;
1828 int ret;
1829 unsigned char hdr[50];
1830 int hdrlen;
1832 buf = "";
1833 if (size)
1834 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1835 close(fd);
1836 if (buf == MAP_FAILED)
1837 return -1;
1839 if (!type)
1840 type = blob_type;
1841 if (write_object)
1842 ret = write_sha1_file(buf, size, type, sha1);
1843 else {
1844 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1845 ret = 0;
1846 }
1847 if (size)
1848 munmap(buf, size);
1849 return ret;
1850 }
1852 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1853 {
1854 int fd;
1855 char *target;
1857 switch (st->st_mode & S_IFMT) {
1858 case S_IFREG:
1859 fd = open(path, O_RDONLY);
1860 if (fd < 0)
1861 return error("open(\"%s\"): %s", path,
1862 strerror(errno));
1863 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1864 return error("%s: failed to insert into database",
1865 path);
1866 break;
1867 case S_IFLNK:
1868 target = xmalloc(st->st_size+1);
1869 if (readlink(path, target, st->st_size+1) != st->st_size) {
1870 char *errstr = strerror(errno);
1871 free(target);
1872 return error("readlink(\"%s\"): %s", path,
1873 errstr);
1874 }
1875 if (!write_object) {
1876 unsigned char hdr[50];
1877 int hdrlen;
1878 write_sha1_file_prepare(target, st->st_size, blob_type,
1879 sha1, hdr, &hdrlen);
1880 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1881 return error("%s: failed to insert into database",
1882 path);
1883 free(target);
1884 break;
1885 default:
1886 return error("%s: unsupported file type", path);
1887 }
1888 return 0;
1889 }