git-pickaxe: do not keep commit buffer.
[git/jrn.git] / sha1_file.c
blob47e2a29abd6d2ae067d72c0f73bcf4e6afe0a938
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) Linus Torvalds, 2005
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 */
64 int get_sha1_hex(const char *hex, unsigned char *sha1)
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;
74 return 0;
77 int safe_create_leading_directories(char *path)
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;
97 else if (mkdir(path, 0777)) {
98 *pos = '/';
99 return -1;
101 else if (adjust_shared_perm(path)) {
102 *pos = '/';
103 return -2;
105 *pos++ = '/';
107 return 0;
110 char * sha1_to_hex(const unsigned char *sha1)
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];
123 *buf = '\0';
125 return buffer;
128 static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
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];
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.
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.
150 char *sha1_file_name(const unsigned char *sha1)
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;
164 fill_sha1_path(name, sha1);
165 return base;
168 char *sha1_pack_name(const unsigned char *sha1)
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;
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];
190 return base;
193 char *sha1_pack_index_name(const unsigned char *sha1)
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;
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];
215 return base;
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);
224 * Prepare alternate object database registry.
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.
238 static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
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;
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);
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;
279 /* Prevent the common mistake of listing the same
280 * thing twice, or object directory itself.
282 for (alt = alt_odb_list; alt; alt = alt->next) {
283 if (!memcmp(ent->base, alt->base, pfxlen)) {
284 free(ent);
285 return -1;
288 if (!memcmp(ent->base, objdir, pfxlen)) {
289 free(ent);
290 return -1;
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;
306 static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
307 const char *relative_base, int depth)
309 const char *cp, *last;
311 if (depth > 5) {
312 error("%s: ignoring alternate object stores, nesting too deep.",
313 relative_base);
314 return;
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;
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);
337 while (cp < ep && *cp == sep)
338 cp++;
339 last = cp;
343 static void read_info_alternates(const char * relative_base, int depth)
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;
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);
368 void prepare_alt_odb(void)
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);
383 static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
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;
397 return NULL;
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_)
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;
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;
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
448 if (idx_size != 4*256 + nr * 24 + 20 + 20)
449 return error("wrong index file size");
451 return 0;
454 static int unuse_one_packed_git(void)
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;
464 if (!lru)
465 return 0;
466 munmap(lru->pack_base, lru->pack_size);
467 lru->pack_base = NULL;
468 return 1;
471 void unuse_packed_git(struct packed_git *p)
473 p->pack_use_cnt--;
476 int use_packed_git(struct packed_git *p)
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;
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);
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.
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.
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);
531 p->pack_last_used = pack_used_ctr++;
532 p->pack_use_cnt++;
533 return 0;
536 struct packed_git *add_packed_git(char *path, int path_len, int local)
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;
553 /* ok, it looks sane as far as we can check without
554 * actually mapping the pack file.
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;
571 struct packed_git *parse_pack_index(unsigned char *sha1)
573 char *path = sha1_pack_index_name(sha1);
574 return parse_pack_index_file(sha1, path);
577 struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
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;
602 void install_packed_git(struct packed_git *pack)
604 pack->next = packed_git;
605 packed_git = pack;
608 static void prepare_packed_git_one(char *objdir, int local)
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;
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;
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;
646 closedir(dir);
649 static int prepare_packed_git_run_once = 0;
650 void prepare_packed_git(void)
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] = '/';
663 prepare_packed_git_run_once = 1;
666 static void reprepare_packed_git(void)
668 prepare_packed_git_run_once = 0;
669 prepare_packed_git();
672 int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
674 unsigned char real_sha1[20];
675 hash_sha1_file(map, size, type, real_sha1);
676 return hashcmp(sha1, real_sha1) ? -1 : 0;
679 void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
681 struct stat st;
682 void *map;
683 int fd;
684 char *filename = find_sha1_file(sha1, &st);
686 if (!filename) {
687 return NULL;
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;
703 /* If it failed once, it will probably fail again.
704 * Stop using O_NOATIME
706 sha1_file_open_flag = 0;
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;
716 int legacy_loose_object(unsigned char *map)
718 unsigned int word;
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
725 word = (map[0] << 8) + map[1];
726 if (map[0] == 0x78 && !(word % 31))
727 return 1;
728 else
729 return 0;
732 unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
734 unsigned shift;
735 unsigned char c;
736 unsigned long size;
737 unsigned long used = 0;
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;
752 *sizep = size;
753 return used;
756 static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
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 */
764 enum object_type type;
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;
773 if (legacy_loose_object(map)) {
774 inflateInit(stream);
775 return inflate(stream, 0);
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;
784 /* Set up the stream for the rest.. */
785 stream->next_in = map;
786 stream->avail_in = mapsize;
787 inflateInit(stream);
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;
795 static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
797 int bytes = strlen(buffer) + 1;
798 unsigned char *buf = xmalloc(1+size);
799 unsigned long n;
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 */;
812 buf[size] = 0;
813 inflateEnd(stream);
814 return buf;
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.
822 static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
824 int i;
825 unsigned long size;
828 * The type can be at most ten bytes (including the
829 * terminating '\0' that we add), and is followed by
830 * a space.
832 i = 10;
833 for (;;) {
834 char c = *hdr++;
835 if (c == ' ')
836 break;
837 if (!--i)
838 return -1;
839 *type++ = c;
841 *type = 0;
844 * The length must follow immediately, and be in canonical
845 * decimal format (ie "010" is not valid).
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;
859 *sizep = size;
862 * The length must be followed by a zero byte
864 return *hdr ? -1 : 0;
867 void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
869 int ret;
870 z_stream stream;
871 char hdr[8192];
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;
877 return unpack_sha1_rest(&stream, hdr, *size);
880 /* forward declaration for a mutually recursive function */
881 static int packed_object_info(struct packed_git *p, unsigned long offset,
882 char *type, unsigned long *sizep);
884 static int packed_delta_info(struct packed_git *p,
885 unsigned long offset,
886 char *type,
887 unsigned long *sizep)
889 unsigned long base_offset;
890 unsigned char *base_sha1 = (unsigned char *) p->pack_base + offset;
892 if (p->pack_size < offset + 20)
893 die("truncated pack file");
894 /* The base entry _must_ be in the same pack */
895 base_offset = find_pack_entry_one(base_sha1, p);
896 if (!base_offset)
897 die("failed to find delta-pack base object %s",
898 sha1_to_hex(base_sha1));
899 offset += 20;
901 /* We choose to only get the type of the base object and
902 * ignore potentially corrupt pack file that expects the delta
903 * based on a base with a wrong size. This saves tons of
904 * inflate() calls.
906 if (packed_object_info(p, base_offset, type, NULL))
907 die("cannot get info for delta-pack base");
909 if (sizep) {
910 const unsigned char *data;
911 unsigned char delta_head[20];
912 unsigned long result_size;
913 z_stream stream;
914 int st;
916 memset(&stream, 0, sizeof(stream));
918 stream.next_in = (unsigned char *) p->pack_base + offset;
919 stream.avail_in = p->pack_size - offset;
920 stream.next_out = delta_head;
921 stream.avail_out = sizeof(delta_head);
923 inflateInit(&stream);
924 st = inflate(&stream, Z_FINISH);
925 inflateEnd(&stream);
926 if ((st != Z_STREAM_END) &&
927 stream.total_out != sizeof(delta_head))
928 die("delta data unpack-initial failed");
930 /* Examine the initial part of the delta to figure out
931 * the result size.
933 data = delta_head;
935 /* ignore base size */
936 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
938 /* Read the result size */
939 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
940 *sizep = result_size;
942 return 0;
945 static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
946 enum object_type *type, unsigned long *sizep)
948 unsigned long used;
950 if (p->pack_size <= offset)
951 die("object offset outside of pack file");
953 used = unpack_object_header_gently((unsigned char *)p->pack_base +
954 offset,
955 p->pack_size - offset, type, sizep);
956 if (!used)
957 die("object offset outside of pack file");
959 return offset + used;
962 int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
963 unsigned char *base, unsigned long *sizep,
964 enum object_type *kindp)
966 unsigned long ptr;
967 int status = -1;
969 use_packed_git(p);
970 ptr = offset;
971 ptr = unpack_object_header(p, ptr, kindp, sizep);
972 if (*kindp != OBJ_DELTA)
973 goto done;
974 hashcpy(base, (unsigned char *) p->pack_base + ptr);
975 status = 0;
976 done:
977 unuse_packed_git(p);
978 return status;
981 void packed_object_info_detail(struct packed_git *p,
982 unsigned long offset,
983 char *type,
984 unsigned long *size,
985 unsigned long *store_size,
986 unsigned int *delta_chain_length,
987 unsigned char *base_sha1)
989 unsigned long val;
990 unsigned char *next_sha1;
991 enum object_type kind;
993 *delta_chain_length = 0;
994 offset = unpack_object_header(p, offset, &kind, size);
996 for (;;) {
997 switch (kind) {
998 default:
999 die("corrupted pack file %s containing object of kind %d",
1000 p->pack_name, kind);
1001 case OBJ_COMMIT:
1002 case OBJ_TREE:
1003 case OBJ_BLOB:
1004 case OBJ_TAG:
1005 strcpy(type, type_names[kind]);
1006 *store_size = 0; /* notyet */
1007 return;
1008 case OBJ_DELTA:
1009 if (p->pack_size <= offset + 20)
1010 die("pack file %s records an incomplete delta base",
1011 p->pack_name);
1012 next_sha1 = (unsigned char *) p->pack_base + offset;
1013 if (*delta_chain_length == 0)
1014 hashcpy(base_sha1, next_sha1);
1015 offset = find_pack_entry_one(next_sha1, p);
1016 break;
1018 offset = unpack_object_header(p, offset, &kind, &val);
1019 (*delta_chain_length)++;
1023 static int packed_object_info(struct packed_git *p, unsigned long offset,
1024 char *type, unsigned long *sizep)
1026 unsigned long size;
1027 enum object_type kind;
1029 offset = unpack_object_header(p, offset, &kind, &size);
1031 if (kind == OBJ_DELTA)
1032 return packed_delta_info(p, offset, type, sizep);
1034 switch (kind) {
1035 case OBJ_COMMIT:
1036 case OBJ_TREE:
1037 case OBJ_BLOB:
1038 case OBJ_TAG:
1039 strcpy(type, type_names[kind]);
1040 break;
1041 default:
1042 die("corrupted pack file %s containing object of kind %d",
1043 p->pack_name, kind);
1045 if (sizep)
1046 *sizep = size;
1047 return 0;
1050 static void *unpack_compressed_entry(struct packed_git *p,
1051 unsigned long offset,
1052 unsigned long size)
1054 int st;
1055 z_stream stream;
1056 unsigned char *buffer;
1058 buffer = xmalloc(size + 1);
1059 buffer[size] = 0;
1060 memset(&stream, 0, sizeof(stream));
1061 stream.next_in = (unsigned char*)p->pack_base + offset;
1062 stream.avail_in = p->pack_size - offset;
1063 stream.next_out = buffer;
1064 stream.avail_out = size;
1066 inflateInit(&stream);
1067 st = inflate(&stream, Z_FINISH);
1068 inflateEnd(&stream);
1069 if ((st != Z_STREAM_END) || stream.total_out != size) {
1070 free(buffer);
1071 return NULL;
1074 return buffer;
1077 static void *unpack_delta_entry(struct packed_git *p,
1078 unsigned long offset,
1079 unsigned long delta_size,
1080 char *type,
1081 unsigned long *sizep)
1083 void *delta_data, *result, *base;
1084 unsigned long result_size, base_size, base_offset;
1085 unsigned char *base_sha1;
1087 if (p->pack_size < offset + 20)
1088 die("truncated pack file");
1089 /* The base entry _must_ be in the same pack */
1090 base_sha1 = (unsigned char*)p->pack_base + offset;
1091 base_offset = find_pack_entry_one(base_sha1, p);
1092 if (!base_offset)
1093 die("failed to find delta-pack base object %s",
1094 sha1_to_hex(base_sha1));
1095 offset += 20;
1097 base = unpack_entry_gently(p, base_offset, type, &base_size);
1098 if (!base)
1099 die("failed to read delta base object at %lu from %s",
1100 base_offset, p->pack_name);
1102 delta_data = unpack_compressed_entry(p, offset, delta_size);
1103 result = patch_delta(base, base_size,
1104 delta_data, delta_size,
1105 &result_size);
1106 if (!result)
1107 die("failed to apply delta");
1108 free(delta_data);
1109 free(base);
1110 *sizep = result_size;
1111 return result;
1114 static void *unpack_entry(struct pack_entry *entry,
1115 char *type, unsigned long *sizep)
1117 struct packed_git *p = entry->p;
1118 void *retval;
1120 if (use_packed_git(p))
1121 die("cannot map packed file");
1122 retval = unpack_entry_gently(p, entry->offset, type, sizep);
1123 unuse_packed_git(p);
1124 if (!retval)
1125 die("corrupted pack file %s", p->pack_name);
1126 return retval;
1129 /* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1130 void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
1131 char *type, unsigned long *sizep)
1133 unsigned long size;
1134 enum object_type kind;
1136 offset = unpack_object_header(p, offset, &kind, &size);
1137 switch (kind) {
1138 case OBJ_DELTA:
1139 return unpack_delta_entry(p, offset, size, type, sizep);
1140 case OBJ_COMMIT:
1141 case OBJ_TREE:
1142 case OBJ_BLOB:
1143 case OBJ_TAG:
1144 strcpy(type, type_names[kind]);
1145 *sizep = size;
1146 return unpack_compressed_entry(p, offset, size);
1147 default:
1148 return NULL;
1152 int num_packed_objects(const struct packed_git *p)
1154 /* See check_packed_git_idx() */
1155 return (p->index_size - 20 - 20 - 4*256) / 24;
1158 int nth_packed_object_sha1(const struct packed_git *p, int n,
1159 unsigned char* sha1)
1161 void *index = p->index_base + 256;
1162 if (n < 0 || num_packed_objects(p) <= n)
1163 return -1;
1164 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
1165 return 0;
1168 unsigned long find_pack_entry_one(const unsigned char *sha1,
1169 struct packed_git *p)
1171 unsigned int *level1_ofs = p->index_base;
1172 int hi = ntohl(level1_ofs[*sha1]);
1173 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1174 void *index = p->index_base + 256;
1176 do {
1177 int mi = (lo + hi) / 2;
1178 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1179 if (!cmp)
1180 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1181 if (cmp > 0)
1182 hi = mi;
1183 else
1184 lo = mi+1;
1185 } while (lo < hi);
1186 return 0;
1189 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1191 struct packed_git *p;
1192 unsigned long offset;
1194 prepare_packed_git();
1196 for (p = packed_git; p; p = p->next) {
1197 if (ignore_packed) {
1198 const char **ig;
1199 for (ig = ignore_packed; *ig; ig++)
1200 if (!strcmp(p->pack_name, *ig))
1201 break;
1202 if (*ig)
1203 continue;
1205 offset = find_pack_entry_one(sha1, p);
1206 if (offset) {
1207 e->offset = offset;
1208 e->p = p;
1209 hashcpy(e->sha1, sha1);
1210 return 1;
1213 return 0;
1216 struct packed_git *find_sha1_pack(const unsigned char *sha1,
1217 struct packed_git *packs)
1219 struct packed_git *p;
1221 for (p = packs; p; p = p->next) {
1222 if (find_pack_entry_one(sha1, p))
1223 return p;
1225 return NULL;
1229 int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1231 int status;
1232 unsigned long mapsize, size;
1233 void *map;
1234 z_stream stream;
1235 char hdr[128];
1237 map = map_sha1_file(sha1, &mapsize);
1238 if (!map) {
1239 struct pack_entry e;
1241 if (!find_pack_entry(sha1, &e, NULL)) {
1242 reprepare_packed_git();
1243 if (!find_pack_entry(sha1, &e, NULL))
1244 return error("unable to find %s", sha1_to_hex(sha1));
1246 if (use_packed_git(e.p))
1247 die("cannot map packed file");
1248 status = packed_object_info(e.p, e.offset, type, sizep);
1249 unuse_packed_git(e.p);
1250 return status;
1252 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1253 status = error("unable to unpack %s header",
1254 sha1_to_hex(sha1));
1255 if (parse_sha1_header(hdr, type, &size) < 0)
1256 status = error("unable to parse %s header", sha1_to_hex(sha1));
1257 else {
1258 status = 0;
1259 if (sizep)
1260 *sizep = size;
1262 inflateEnd(&stream);
1263 munmap(map, mapsize);
1264 return status;
1267 static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1269 struct pack_entry e;
1271 if (!find_pack_entry(sha1, &e, NULL)) {
1272 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1273 return NULL;
1275 return unpack_entry(&e, type, size);
1278 void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1280 unsigned long mapsize;
1281 void *map, *buf;
1282 struct pack_entry e;
1284 if (find_pack_entry(sha1, &e, NULL))
1285 return read_packed_sha1(sha1, type, size);
1286 map = map_sha1_file(sha1, &mapsize);
1287 if (map) {
1288 buf = unpack_sha1_file(map, mapsize, type, size);
1289 munmap(map, mapsize);
1290 return buf;
1292 reprepare_packed_git();
1293 if (find_pack_entry(sha1, &e, NULL))
1294 return read_packed_sha1(sha1, type, size);
1295 return NULL;
1298 void *read_object_with_reference(const unsigned char *sha1,
1299 const char *required_type,
1300 unsigned long *size,
1301 unsigned char *actual_sha1_return)
1303 char type[20];
1304 void *buffer;
1305 unsigned long isize;
1306 unsigned char actual_sha1[20];
1308 hashcpy(actual_sha1, sha1);
1309 while (1) {
1310 int ref_length = -1;
1311 const char *ref_type = NULL;
1313 buffer = read_sha1_file(actual_sha1, type, &isize);
1314 if (!buffer)
1315 return NULL;
1316 if (!strcmp(type, required_type)) {
1317 *size = isize;
1318 if (actual_sha1_return)
1319 hashcpy(actual_sha1_return, actual_sha1);
1320 return buffer;
1322 /* Handle references */
1323 else if (!strcmp(type, commit_type))
1324 ref_type = "tree ";
1325 else if (!strcmp(type, tag_type))
1326 ref_type = "object ";
1327 else {
1328 free(buffer);
1329 return NULL;
1331 ref_length = strlen(ref_type);
1333 if (memcmp(buffer, ref_type, ref_length) ||
1334 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
1335 free(buffer);
1336 return NULL;
1338 free(buffer);
1339 /* Now we have the ID of the referred-to object in
1340 * actual_sha1. Check again. */
1344 static void write_sha1_file_prepare(void *buf, unsigned long len,
1345 const char *type, unsigned char *sha1,
1346 unsigned char *hdr, int *hdrlen)
1348 SHA_CTX c;
1350 /* Generate the header */
1351 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1353 /* Sha1.. */
1354 SHA1_Init(&c);
1355 SHA1_Update(&c, hdr, *hdrlen);
1356 SHA1_Update(&c, buf, len);
1357 SHA1_Final(sha1, &c);
1361 * Link the tempfile to the final place, possibly creating the
1362 * last directory level as you do so.
1364 * Returns the errno on failure, 0 on success.
1366 static int link_temp_to_file(const char *tmpfile, const char *filename)
1368 int ret;
1369 char *dir;
1371 if (!link(tmpfile, filename))
1372 return 0;
1375 * Try to mkdir the last path component if that failed.
1377 * Re-try the "link()" regardless of whether the mkdir
1378 * succeeds, since a race might mean that somebody
1379 * else succeeded.
1381 ret = errno;
1382 dir = strrchr(filename, '/');
1383 if (dir) {
1384 *dir = 0;
1385 mkdir(filename, 0777);
1386 if (adjust_shared_perm(filename))
1387 return -2;
1388 *dir = '/';
1389 if (!link(tmpfile, filename))
1390 return 0;
1391 ret = errno;
1393 return ret;
1397 * Move the just written object into its final resting place
1399 int move_temp_to_file(const char *tmpfile, const char *filename)
1401 int ret = link_temp_to_file(tmpfile, filename);
1404 * Coda hack - coda doesn't like cross-directory links,
1405 * so we fall back to a rename, which will mean that it
1406 * won't be able to check collisions, but that's not a
1407 * big deal.
1409 * The same holds for FAT formatted media.
1411 * When this succeeds, we just return 0. We have nothing
1412 * left to unlink.
1414 if (ret && ret != EEXIST) {
1415 if (!rename(tmpfile, filename))
1416 return 0;
1417 ret = errno;
1419 unlink(tmpfile);
1420 if (ret) {
1421 if (ret != EEXIST) {
1422 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
1423 return -1;
1425 /* FIXME!!! Collision check here ? */
1428 return 0;
1431 static int write_buffer(int fd, const void *buf, size_t len)
1433 while (len) {
1434 ssize_t size;
1436 size = write(fd, buf, len);
1437 if (!size)
1438 return error("file write: disk full");
1439 if (size < 0) {
1440 if (errno == EINTR || errno == EAGAIN)
1441 continue;
1442 return error("file write error (%s)", strerror(errno));
1444 len -= size;
1445 buf = (char *) buf + size;
1447 return 0;
1450 static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1452 int hdr_len;
1453 unsigned char c;
1455 c = (type << 4) | (len & 15);
1456 len >>= 4;
1457 hdr_len = 1;
1458 while (len) {
1459 *hdr++ = c | 0x80;
1460 hdr_len++;
1461 c = (len & 0x7f);
1462 len >>= 7;
1464 *hdr = c;
1465 return hdr_len;
1468 static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1470 int obj_type, hdr;
1472 if (use_legacy_headers) {
1473 while (deflate(stream, 0) == Z_OK)
1474 /* nothing */;
1475 return;
1477 if (!strcmp(type, blob_type))
1478 obj_type = OBJ_BLOB;
1479 else if (!strcmp(type, tree_type))
1480 obj_type = OBJ_TREE;
1481 else if (!strcmp(type, commit_type))
1482 obj_type = OBJ_COMMIT;
1483 else if (!strcmp(type, tag_type))
1484 obj_type = OBJ_TAG;
1485 else
1486 die("trying to generate bogus object of type '%s'", type);
1487 hdr = write_binary_header(stream->next_out, obj_type, len);
1488 stream->total_out = hdr;
1489 stream->next_out += hdr;
1490 stream->avail_out -= hdr;
1493 int hash_sha1_file(void *buf, unsigned long len, const char *type,
1494 unsigned char *sha1)
1496 unsigned char hdr[50];
1497 int hdrlen;
1498 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1499 return 0;
1502 int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
1504 int size;
1505 unsigned char *compressed;
1506 z_stream stream;
1507 unsigned char sha1[20];
1508 char *filename;
1509 static char tmpfile[PATH_MAX];
1510 unsigned char hdr[50];
1511 int fd, hdrlen;
1513 /* Normally if we have it in the pack then we do not bother writing
1514 * it out into .git/objects/??/?{38} file.
1516 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1517 filename = sha1_file_name(sha1);
1518 if (returnsha1)
1519 hashcpy(returnsha1, sha1);
1520 if (has_sha1_file(sha1))
1521 return 0;
1522 fd = open(filename, O_RDONLY);
1523 if (fd >= 0) {
1525 * FIXME!!! We might do collision checking here, but we'd
1526 * need to uncompress the old file and check it. Later.
1528 close(fd);
1529 return 0;
1532 if (errno != ENOENT) {
1533 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
1534 return -1;
1537 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1539 fd = mkstemp(tmpfile);
1540 if (fd < 0) {
1541 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1542 return -1;
1545 /* Set it up */
1546 memset(&stream, 0, sizeof(stream));
1547 deflateInit(&stream, zlib_compression_level);
1548 size = 8 + deflateBound(&stream, len+hdrlen);
1549 compressed = xmalloc(size);
1551 /* Compress it */
1552 stream.next_out = compressed;
1553 stream.avail_out = size;
1555 /* First header.. */
1556 stream.next_in = hdr;
1557 stream.avail_in = hdrlen;
1558 setup_object_header(&stream, type, len);
1560 /* Then the data itself.. */
1561 stream.next_in = buf;
1562 stream.avail_in = len;
1563 while (deflate(&stream, Z_FINISH) == Z_OK)
1564 /* nothing */;
1565 deflateEnd(&stream);
1566 size = stream.total_out;
1568 if (write_buffer(fd, compressed, size) < 0)
1569 die("unable to write sha1 file");
1570 fchmod(fd, 0444);
1571 close(fd);
1572 free(compressed);
1574 return move_temp_to_file(tmpfile, filename);
1578 * We need to unpack and recompress the object for writing
1579 * it out to a different file.
1581 static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
1583 size_t size;
1584 z_stream stream;
1585 unsigned char *unpacked;
1586 unsigned long len;
1587 char type[20];
1588 char hdr[50];
1589 int hdrlen;
1590 void *buf;
1592 /* need to unpack and recompress it by itself */
1593 unpacked = read_packed_sha1(sha1, type, &len);
1595 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
1597 /* Set it up */
1598 memset(&stream, 0, sizeof(stream));
1599 deflateInit(&stream, zlib_compression_level);
1600 size = deflateBound(&stream, len + hdrlen);
1601 buf = xmalloc(size);
1603 /* Compress it */
1604 stream.next_out = buf;
1605 stream.avail_out = size;
1607 /* First header.. */
1608 stream.next_in = (void *)hdr;
1609 stream.avail_in = hdrlen;
1610 while (deflate(&stream, 0) == Z_OK)
1611 /* nothing */;
1613 /* Then the data itself.. */
1614 stream.next_in = unpacked;
1615 stream.avail_in = len;
1616 while (deflate(&stream, Z_FINISH) == Z_OK)
1617 /* nothing */;
1618 deflateEnd(&stream);
1619 free(unpacked);
1621 *objsize = stream.total_out;
1622 return buf;
1625 int write_sha1_to_fd(int fd, const unsigned char *sha1)
1627 int retval;
1628 unsigned long objsize;
1629 void *buf = map_sha1_file(sha1, &objsize);
1631 if (buf) {
1632 retval = write_buffer(fd, buf, objsize);
1633 munmap(buf, objsize);
1634 return retval;
1637 buf = repack_object(sha1, &objsize);
1638 retval = write_buffer(fd, buf, objsize);
1639 free(buf);
1640 return retval;
1643 int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1644 size_t bufsize, size_t *bufposn)
1646 char tmpfile[PATH_MAX];
1647 int local;
1648 z_stream stream;
1649 unsigned char real_sha1[20];
1650 unsigned char discard[4096];
1651 int ret;
1652 SHA_CTX c;
1654 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
1656 local = mkstemp(tmpfile);
1657 if (local < 0)
1658 return error("Couldn't open %s for %s",
1659 tmpfile, sha1_to_hex(sha1));
1661 memset(&stream, 0, sizeof(stream));
1663 inflateInit(&stream);
1665 SHA1_Init(&c);
1667 do {
1668 ssize_t size;
1669 if (*bufposn) {
1670 stream.avail_in = *bufposn;
1671 stream.next_in = (unsigned char *) buffer;
1672 do {
1673 stream.next_out = discard;
1674 stream.avail_out = sizeof(discard);
1675 ret = inflate(&stream, Z_SYNC_FLUSH);
1676 SHA1_Update(&c, discard, sizeof(discard) -
1677 stream.avail_out);
1678 } while (stream.avail_in && ret == Z_OK);
1679 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1680 die("unable to write sha1 file");
1681 memmove(buffer, buffer + *bufposn - stream.avail_in,
1682 stream.avail_in);
1683 *bufposn = stream.avail_in;
1684 if (ret != Z_OK)
1685 break;
1687 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
1688 if (size <= 0) {
1689 close(local);
1690 unlink(tmpfile);
1691 if (!size)
1692 return error("Connection closed?");
1693 perror("Reading from connection");
1694 return -1;
1696 *bufposn += size;
1697 } while (1);
1698 inflateEnd(&stream);
1700 close(local);
1701 SHA1_Final(real_sha1, &c);
1702 if (ret != Z_STREAM_END) {
1703 unlink(tmpfile);
1704 return error("File %s corrupted", sha1_to_hex(sha1));
1706 if (hashcmp(sha1, real_sha1)) {
1707 unlink(tmpfile);
1708 return error("File %s has bad hash", sha1_to_hex(sha1));
1711 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
1714 int has_pack_index(const unsigned char *sha1)
1716 struct stat st;
1717 if (stat(sha1_pack_index_name(sha1), &st))
1718 return 0;
1719 return 1;
1722 int has_pack_file(const unsigned char *sha1)
1724 struct stat st;
1725 if (stat(sha1_pack_name(sha1), &st))
1726 return 0;
1727 return 1;
1730 int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
1732 struct pack_entry e;
1733 return find_pack_entry(sha1, &e, ignore_packed);
1736 int has_sha1_file(const unsigned char *sha1)
1738 struct stat st;
1739 struct pack_entry e;
1741 if (find_pack_entry(sha1, &e, NULL))
1742 return 1;
1743 return find_sha1_file(sha1, &st) ? 1 : 0;
1747 * reads from fd as long as possible into a supplied buffer of size bytes.
1748 * If necessary the buffer's size is increased using realloc()
1750 * returns 0 if anything went fine and -1 otherwise
1752 * NOTE: both buf and size may change, but even when -1 is returned
1753 * you still have to free() it yourself.
1755 int read_pipe(int fd, char** return_buf, unsigned long* return_size)
1757 char* buf = *return_buf;
1758 unsigned long size = *return_size;
1759 int iret;
1760 unsigned long off = 0;
1762 do {
1763 iret = xread(fd, buf + off, size - off);
1764 if (iret > 0) {
1765 off += iret;
1766 if (off == size) {
1767 size *= 2;
1768 buf = xrealloc(buf, size);
1771 } while (iret > 0);
1773 *return_buf = buf;
1774 *return_size = off;
1776 if (iret < 0)
1777 return -1;
1778 return 0;
1781 int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1783 unsigned long size = 4096;
1784 char *buf = xmalloc(size);
1785 int ret;
1787 if (read_pipe(fd, &buf, &size)) {
1788 free(buf);
1789 return -1;
1792 if (!type)
1793 type = blob_type;
1794 if (write_object)
1795 ret = write_sha1_file(buf, size, type, sha1);
1796 else
1797 ret = hash_sha1_file(buf, size, type, sha1);
1798 free(buf);
1799 return ret;
1802 int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
1804 unsigned long size = st->st_size;
1805 void *buf;
1806 int ret;
1808 buf = "";
1809 if (size)
1810 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
1811 close(fd);
1812 if (buf == MAP_FAILED)
1813 return -1;
1815 if (!type)
1816 type = blob_type;
1817 if (write_object)
1818 ret = write_sha1_file(buf, size, type, sha1);
1819 else
1820 ret = hash_sha1_file(buf, size, type, sha1);
1821 if (size)
1822 munmap(buf, size);
1823 return ret;
1826 int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1828 int fd;
1829 char *target;
1831 switch (st->st_mode & S_IFMT) {
1832 case S_IFREG:
1833 fd = open(path, O_RDONLY);
1834 if (fd < 0)
1835 return error("open(\"%s\"): %s", path,
1836 strerror(errno));
1837 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1838 return error("%s: failed to insert into database",
1839 path);
1840 break;
1841 case S_IFLNK:
1842 target = xmalloc(st->st_size+1);
1843 if (readlink(path, target, st->st_size+1) != st->st_size) {
1844 char *errstr = strerror(errno);
1845 free(target);
1846 return error("readlink(\"%s\"): %s", path,
1847 errstr);
1849 if (!write_object)
1850 hash_sha1_file(target, st->st_size, blob_type, sha1);
1851 else if (write_sha1_file(target, st->st_size, blob_type, sha1))
1852 return error("%s: failed to insert into database",
1853 path);
1854 free(target);
1855 break;
1856 default:
1857 return error("%s: unsupported file type", path);
1859 return 0;