Teach "git clone" about rsync sources
[git/git.git] / sha1_file.c
CommitLineData
0fcfd160
LT
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 */
1f688557
JH
9#include <sys/types.h>
10#include <dirent.h>
0fcfd160 11#include "cache.h"
1f688557 12#include "delta.h"
a733cb60 13#include "pack.h"
0fcfd160 14
144bde78
LT
15#ifndef O_NOATIME
16#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
17#define O_NOATIME 01000000
18#else
19#define O_NOATIME 0
20#endif
21#endif
22
23static unsigned int sha1_file_open_flag = O_NOATIME;
24
0fcfd160
LT
25static unsigned hexval(char c)
26{
27 if (c >= '0' && c <= '9')
28 return c - '0';
29 if (c >= 'a' && c <= 'f')
30 return c - 'a' + 10;
31 if (c >= 'A' && c <= 'F')
32 return c - 'A' + 10;
33 return ~0;
34}
35
36int get_sha1_hex(const char *hex, unsigned char *sha1)
37{
38 int i;
39 for (i = 0; i < 20; i++) {
40 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
41 if (val & ~0xff)
42 return -1;
43 *sha1++ = val;
44 hex += 2;
45 }
46 return 0;
47}
48
e99d59ff 49static int get_sha1_file(const char *path, unsigned char *result)
3c249c95
LT
50{
51 char buffer[60];
52 int fd = open(path, O_RDONLY);
53 int len;
54
55 if (fd < 0)
56 return -1;
57 len = read(fd, buffer, sizeof(buffer));
58 close(fd);
59 if (len < 40)
60 return -1;
61 return get_sha1_hex(buffer, result);
62}
63
95fc7512 64static char *git_dir, *git_object_dir, *git_index_file, *git_refs_dir;
8ac069ac
JH
65static void setup_git_env(void)
66{
67 git_dir = gitenv(GIT_DIR_ENVIRONMENT);
68 if (!git_dir)
69 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
70 git_object_dir = gitenv(DB_ENVIRONMENT);
71 if (!git_object_dir) {
72 git_object_dir = xmalloc(strlen(git_dir) + 9);
73 sprintf(git_object_dir, "%s/objects", git_dir);
74 }
95fc7512
DB
75 git_refs_dir = xmalloc(strlen(git_dir) + 6);
76 sprintf(git_refs_dir, "%s/refs", git_dir);
8ac069ac
JH
77 git_index_file = gitenv(INDEX_ENVIRONMENT);
78 if (!git_index_file) {
79 git_index_file = xmalloc(strlen(git_dir) + 7);
80 sprintf(git_index_file, "%s/index", git_dir);
81 }
82}
83
84char *get_object_directory(void)
85{
86 if (!git_object_dir)
87 setup_git_env();
88 return git_object_dir;
89}
90
95fc7512
DB
91char *get_refs_directory(void)
92{
93 if (!git_refs_dir)
94 setup_git_env();
95 return git_refs_dir;
96}
97
8ac069ac
JH
98char *get_index_file(void)
99{
100 if (!git_index_file)
101 setup_git_env();
102 return git_index_file;
103}
104
b2cb9425
JH
105int safe_create_leading_directories(char *path)
106{
107 char *pos = path;
108
109 while (pos) {
110 pos = strchr(pos, '/');
111 if (!pos)
112 break;
113 *pos = 0;
114 if (mkdir(path, 0777) < 0)
115 if (errno != EEXIST) {
116 *pos = '/';
117 return -1;
118 }
119 *pos++ = '/';
120 }
121 return 0;
122}
723c31fe
LT
123
124int get_sha1(const char *str, unsigned char *sha1)
125{
35ad3382
LT
126 static const char *prefix[] = {
127 "",
128 "refs",
129 "refs/tags",
130 "refs/heads",
131 "refs/snap",
132 NULL
133 };
35ad3382 134 const char **p;
3c249c95
LT
135
136 if (!get_sha1_hex(str, sha1))
137 return 0;
35ad3382 138
35ad3382 139 for (p = prefix; *p; p++) {
723c31fe 140 char * pathname = git_path("%s/%s", *p, str);
35ad3382
LT
141 if (!get_sha1_file(pathname, sha1))
142 return 0;
143 }
144
3c249c95
LT
145 return -1;
146}
147
0fcfd160
LT
148char * sha1_to_hex(const unsigned char *sha1)
149{
150 static char buffer[50];
151 static const char hex[] = "0123456789abcdef";
152 char *buf = buffer;
153 int i;
154
155 for (i = 0; i < 20; i++) {
156 unsigned int val = *sha1++;
157 *buf++ = hex[val >> 4];
158 *buf++ = hex[val & 0xf];
159 }
160 return buffer;
161}
162
ace1534d
JH
163static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
164{
165 int i;
166 for (i = 0; i < 20; i++) {
167 static char hex[] = "0123456789abcdef";
168 unsigned int val = sha1[i];
169 char *pos = pathbuf + i*2 + (i > 0);
170 *pos++ = hex[val >> 4];
171 *pos = hex[val & 0xf];
172 }
173}
174
0fcfd160
LT
175/*
176 * NOTE! This returns a statically allocated buffer, so you have to be
177 * careful about using it. Do a "strdup()" if you need to save the
178 * filename.
ace1534d
JH
179 *
180 * Also note that this returns the location for creating. Reading
181 * SHA1 file can happen from any alternate directory listed in the
d19938ab 182 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 183 * the primary object database.
0fcfd160
LT
184 */
185char *sha1_file_name(const unsigned char *sha1)
186{
0fcfd160
LT
187 static char *name, *base;
188
189 if (!base) {
d19938ab 190 const char *sha1_file_directory = get_object_directory();
0fcfd160 191 int len = strlen(sha1_file_directory);
812666c8 192 base = xmalloc(len + 60);
0fcfd160
LT
193 memcpy(base, sha1_file_directory, len);
194 memset(base+len, 0, 60);
195 base[len] = '/';
196 base[len+3] = '/';
197 name = base + len + 1;
198 }
ace1534d 199 fill_sha1_path(name, sha1);
0fcfd160
LT
200 return base;
201}
202
9a217f2a 203struct alternate_object_database *alt_odb;
ace1534d 204
ddd5d056
JH
205/*
206 * Prepare alternate object database registry.
207 * alt_odb points at an array of struct alternate_object_database.
208 * This array is terminated with an element that has both its base
209 * and name set to NULL. alt_odb[n] comes from n'th non-empty
d19938ab 210 * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
ddd5d056
JH
211 * variable, and its base points at a statically allocated buffer
212 * that contains "/the/directory/corresponding/to/.git/objects/...",
213 * while its name points just after the slash at the end of
214 * ".git/objects/" in the example above, and has enough space to hold
215 * 40-byte hex SHA1, an extra slash for the first level indirection,
216 * and the terminating NUL.
217 * This function allocates the alt_odb array and all the strings
218 * pointed by base fields of the array elements with one xmalloc();
219 * the string pool immediately follows the array.
220 */
9a217f2a 221void prepare_alt_odb(void)
ace1534d
JH
222{
223 int pass, totlen, i;
ace1534d 224 const char *cp, *last;
e99d59ff 225 char *op = NULL;
d19938ab 226 const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
ace1534d 227
9a217f2a
JH
228 if (alt_odb)
229 return;
ddd5d056
JH
230 /* The first pass counts how large an area to allocate to
231 * hold the entire alt_odb structure, including array of
232 * structs and path buffers for them. The second pass fills
233 * the structure and prepares the path buffers for use by
234 * fill_sha1_path().
235 */
ace1534d
JH
236 for (totlen = pass = 0; pass < 2; pass++) {
237 last = alt;
238 i = 0;
239 do {
240 cp = strchr(last, ':') ? : last + strlen(last);
241 if (last != cp) {
242 /* 43 = 40-byte + 2 '/' + terminating NUL */
243 int pfxlen = cp - last;
244 int entlen = pfxlen + 43;
245 if (pass == 0)
246 totlen += entlen;
247 else {
248 alt_odb[i].base = op;
249 alt_odb[i].name = op + pfxlen + 1;
250 memcpy(op, last, pfxlen);
251 op[pfxlen] = op[pfxlen + 3] = '/';
252 op[entlen-1] = 0;
253 op += entlen;
254 }
255 i++;
256 }
257 while (*cp && *cp == ':')
258 cp++;
259 last = cp;
260 } while (*cp);
261 if (pass)
262 break;
ddd5d056 263 alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
e99d59ff 264 alt_odb[i].base = alt_odb[i].name = NULL;
ace1534d
JH
265 op = (char*)(&alt_odb[i+1]);
266 }
267}
268
269static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
270{
271 int i;
272 char *name = sha1_file_name(sha1);
273
274 if (!stat(name, st))
275 return name;
9a217f2a 276 prepare_alt_odb();
ace1534d
JH
277 for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
278 fill_sha1_path(name, sha1);
279 if (!stat(alt_odb[i].base, st))
280 return alt_odb[i].base;
281 }
282 return NULL;
283}
284
1f688557
JH
285#define PACK_MAX_SZ (1<<26)
286static int pack_used_ctr;
287static unsigned long pack_mapped;
9a217f2a 288struct packed_git *packed_git;
1f688557 289
1f688557
JH
290static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
291 void **idx_map_)
292{
293 void *idx_map;
294 unsigned int *index;
295 unsigned long idx_size;
296 int nr, i;
297 int fd = open(path, O_RDONLY);
298 struct stat st;
299 if (fd < 0)
300 return -1;
301 if (fstat(fd, &st)) {
302 close(fd);
303 return -1;
304 }
305 idx_size = st.st_size;
306 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
307 close(fd);
308 if (idx_map == MAP_FAILED)
309 return -1;
310
311 index = idx_map;
4d235c80
LT
312 *idx_map_ = idx_map;
313 *idx_size_ = idx_size;
1f688557
JH
314
315 /* check index map */
f9253394 316 if (idx_size < 4*256 + 20 + 20)
1f688557
JH
317 return error("index file too small");
318 nr = 0;
319 for (i = 0; i < 256; i++) {
320 unsigned int n = ntohl(index[i]);
321 if (n < nr)
322 return error("non-monotonic index");
323 nr = n;
324 }
325
326 /*
327 * Total size:
328 * - 256 index entries 4 bytes each
329 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
330 * - 20-byte SHA1 of the packfile
331 * - 20-byte SHA1 file checksum
332 */
333 if (idx_size != 4*256 + nr * 24 + 20 + 20)
334 return error("wrong index file size");
335
1f688557
JH
336 return 0;
337}
338
f9253394 339static int unuse_one_packed_git(void)
1f688557 340{
f9253394
JH
341 struct packed_git *p, *lru = NULL;
342
343 for (p = packed_git; p; p = p->next) {
344 if (p->pack_use_cnt || !p->pack_base)
345 continue;
346 if (!lru || p->pack_last_used < lru->pack_last_used)
347 lru = p;
348 }
349 if (!lru)
350 return 0;
351 munmap(lru->pack_base, lru->pack_size);
352 lru->pack_base = NULL;
353 return 1;
354}
355
356void unuse_packed_git(struct packed_git *p)
357{
358 p->pack_use_cnt--;
1f688557
JH
359}
360
f9253394 361int use_packed_git(struct packed_git *p)
1f688557
JH
362{
363 if (!p->pack_base) {
364 int fd;
365 struct stat st;
366 void *map;
367
368 pack_mapped += p->pack_size;
f9253394
JH
369 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
370 ; /* nothing */
1f688557
JH
371 fd = open(p->pack_name, O_RDONLY);
372 if (fd < 0)
f9253394 373 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
374 if (fstat(fd, &st)) {
375 close(fd);
f9253394 376 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
377 }
378 if (st.st_size != p->pack_size)
f9253394 379 die("packfile %s size mismatch.", p->pack_name);
1f688557
JH
380 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
381 close(fd);
382 if (map == MAP_FAILED)
f9253394 383 die("packfile %s cannot be mapped.", p->pack_name);
1f688557 384 p->pack_base = map;
f9253394
JH
385
386 /* Check if the pack file matches with the index file.
387 * this is cheap.
388 */
389 if (memcmp((char*)(p->index_base) + p->index_size - 40,
390 p->pack_base + p->pack_size - 20, 20))
391 die("packfile %s does not match index.", p->pack_name);
1f688557
JH
392 }
393 p->pack_last_used = pack_used_ctr++;
f9253394 394 p->pack_use_cnt++;
1f688557
JH
395 return 0;
396}
397
f9253394 398struct packed_git *add_packed_git(char *path, int path_len)
1f688557
JH
399{
400 struct stat st;
401 struct packed_git *p;
402 unsigned long idx_size;
403 void *idx_map;
404
405 if (check_packed_git_idx(path, &idx_size, &idx_map))
406 return NULL;
407
408 /* do we have a corresponding .pack file? */
409 strcpy(path + path_len - 4, ".pack");
410 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
411 munmap(idx_map, idx_size);
412 return NULL;
413 }
414 /* ok, it looks sane as far as we can check without
415 * actually mapping the pack file.
416 */
417 p = xmalloc(sizeof(*p) + path_len + 2);
418 strcpy(p->pack_name, path);
419 p->index_size = idx_size;
420 p->pack_size = st.st_size;
421 p->index_base = idx_map;
422 p->next = NULL;
d85a4fee 423 p->pack_base = NULL;
1f688557 424 p->pack_last_used = 0;
f9253394 425 p->pack_use_cnt = 0;
1f688557
JH
426 return p;
427}
428
429static void prepare_packed_git_one(char *objdir)
430{
431 char path[PATH_MAX];
432 int len;
433 DIR *dir;
434 struct dirent *de;
435
436 sprintf(path, "%s/pack", objdir);
437 len = strlen(path);
438 dir = opendir(path);
439 if (!dir)
440 return;
441 path[len++] = '/';
442 while ((de = readdir(dir)) != NULL) {
443 int namelen = strlen(de->d_name);
444 struct packed_git *p;
445
446 if (strcmp(de->d_name + namelen - 4, ".idx"))
447 continue;
448
449 /* we have .idx. Is it a file we can map? */
450 strcpy(path + len, de->d_name);
451 p = add_packed_git(path, len + namelen);
452 if (!p)
453 continue;
454 p->next = packed_git;
455 packed_git = p;
456 }
5b35bcd5 457 closedir(dir);
1f688557
JH
458}
459
9a217f2a 460void prepare_packed_git(void)
1f688557
JH
461{
462 int i;
463 static int run_once = 0;
464
465 if (run_once++)
466 return;
467
468 prepare_packed_git_one(get_object_directory());
9a217f2a 469 prepare_alt_odb();
1f688557
JH
470 for (i = 0; alt_odb[i].base != NULL; i++) {
471 alt_odb[i].name[0] = 0;
472 prepare_packed_git_one(alt_odb[i].base);
473 }
474}
475
5d6ccf5c 476int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160 477{
d98b46f8 478 char header[100];
0fcfd160
LT
479 unsigned char real_sha1[20];
480 SHA_CTX c;
481
482 SHA1_Init(&c);
d98b46f8 483 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
0fcfd160
LT
484 SHA1_Update(&c, map, size);
485 SHA1_Final(real_sha1, &c);
486 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
487}
488
1f688557
JH
489static void *map_sha1_file_internal(const unsigned char *sha1,
490 unsigned long *size,
491 int say_error)
0fcfd160 492{
0fcfd160
LT
493 struct stat st;
494 void *map;
144bde78 495 int fd;
ace1534d
JH
496 char *filename = find_sha1_file(sha1, &st);
497
498 if (!filename) {
1f688557
JH
499 if (say_error)
500 error("cannot map sha1 file %s", sha1_to_hex(sha1));
ace1534d
JH
501 return NULL;
502 }
0fcfd160 503
144bde78 504 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 505 if (fd < 0) {
144bde78
LT
506 /* See if it works without O_NOATIME */
507 switch (sha1_file_open_flag) {
508 default:
509 fd = open(filename, O_RDONLY);
510 if (fd >= 0)
511 break;
512 /* Fallthrough */
513 case 0:
1f688557
JH
514 if (say_error)
515 perror(filename);
144bde78
LT
516 return NULL;
517 }
518
1f688557
JH
519 /* If it failed once, it will probably fail again.
520 * Stop using O_NOATIME
521 */
144bde78 522 sha1_file_open_flag = 0;
0fcfd160 523 }
0fcfd160
LT
524 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
525 close(fd);
526 if (-1 == (int)(long)map)
527 return NULL;
528 *size = st.st_size;
529 return map;
530}
531
1f688557
JH
532void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
533{
534 return map_sha1_file_internal(sha1, size, 1);
535}
536
c4483576
LT
537int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
538{
539 /* Get the data stream */
540 memset(stream, 0, sizeof(*stream));
541 stream->next_in = map;
542 stream->avail_in = mapsize;
543 stream->next_out = buffer;
544 stream->avail_out = size;
545
546 inflateInit(stream);
547 return inflate(stream, 0);
548}
549
6da4016a 550static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
5180cacc
LT
551{
552 int bytes = strlen(buffer) + 1;
d565b341 553 unsigned char *buf = xmalloc(1+size);
5180cacc
LT
554
555 memcpy(buf, buffer + bytes, stream->total_out - bytes);
556 bytes = stream->total_out - bytes;
557 if (bytes < size) {
558 stream->next_out = buf + bytes;
559 stream->avail_out = size - bytes;
560 while (inflate(stream, Z_FINISH) == Z_OK)
561 /* nothing */;
562 }
563 buf[size] = 0;
564 inflateEnd(stream);
565 return buf;
566}
567
568/*
569 * We used to just use "sscanf()", but that's actually way
570 * too permissive for what we want to check. So do an anal
571 * object header parse by hand.
572 */
573int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
574{
575 int i;
576 unsigned long size;
577
578 /*
579 * The type can be at most ten bytes (including the
580 * terminating '\0' that we add), and is followed by
581 * a space.
582 */
583 i = 10;
584 for (;;) {
585 char c = *hdr++;
586 if (c == ' ')
587 break;
588 if (!--i)
589 return -1;
590 *type++ = c;
591 }
592 *type = 0;
593
594 /*
595 * The length must follow immediately, and be in canonical
596 * decimal format (ie "010" is not valid).
597 */
598 size = *hdr++ - '0';
599 if (size > 9)
600 return -1;
601 if (size) {
602 for (;;) {
603 unsigned long c = *hdr - '0';
604 if (c > 9)
605 break;
606 hdr++;
607 size = size * 10 + c;
608 }
609 }
610 *sizep = size;
611
612 /*
613 * The length must be followed by a zero byte
614 */
615 return *hdr ? -1 : 0;
616}
617
0fcfd160
LT
618void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
619{
5180cacc 620 int ret;
0fcfd160 621 z_stream stream;
5180cacc 622 char hdr[8192];
0fcfd160 623
5180cacc
LT
624 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
625 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
626 return NULL;
627
5180cacc 628 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
629}
630
f3bf9224
JH
631/* forward declaration for a mutually recursive function */
632static int packed_object_info(struct pack_entry *entry,
633 char *type, unsigned long *sizep);
634
5db47c2b
JH
635static int packed_delta_info(unsigned char *base_sha1,
636 unsigned long delta_size,
637 unsigned long left,
638 char *type,
f3bf9224
JH
639 unsigned long *sizep,
640 struct packed_git *p)
5db47c2b 641{
f3bf9224
JH
642 struct pack_entry base_ent;
643
5db47c2b
JH
644 if (left < 20)
645 die("truncated pack file");
5db47c2b 646
f3bf9224
JH
647 /* The base entry _must_ be in the same pack */
648 if (!find_pack_entry_one(base_sha1, &base_ent, p))
649 die("failed to find delta-pack base object %s",
650 sha1_to_hex(base_sha1));
651
c62266f3
JH
652 /* We choose to only get the type of the base object and
653 * ignore potentially corrupt pack file that expects the delta
654 * based on a base with a wrong size. This saves tons of
655 * inflate() calls.
656 */
5db47c2b 657
f3bf9224 658 if (packed_object_info(&base_ent, type, NULL))
c62266f3 659 die("cannot get info for delta-pack base");
5db47c2b 660
c62266f3
JH
661 if (sizep) {
662 const unsigned char *data;
663 unsigned char delta_head[64];
664 unsigned long result_size;
665 z_stream stream;
666 int st;
667
668 memset(&stream, 0, sizeof(stream));
669
670 data = stream.next_in = base_sha1 + 20;
671 stream.avail_in = left - 20;
672 stream.next_out = delta_head;
673 stream.avail_out = sizeof(delta_head);
674
675 inflateInit(&stream);
676 st = inflate(&stream, Z_FINISH);
677 inflateEnd(&stream);
678 if ((st != Z_STREAM_END) &&
679 stream.total_out != sizeof(delta_head))
680 die("delta data unpack-initial failed");
681
682 /* Examine the initial part of the delta to figure out
683 * the result size.
684 */
685 data = delta_head;
686 get_delta_hdr_size(&data); /* ignore base size */
5db47c2b 687
c62266f3
JH
688 /* Read the result size */
689 result_size = get_delta_hdr_size(&data);
690 *sizep = result_size;
691 }
5db47c2b
JH
692 return 0;
693}
694
a733cb60
LT
695static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
696 enum object_type *type, unsigned long *sizep)
697{
01247d87 698 unsigned shift;
a733cb60
LT
699 unsigned char *pack, c;
700 unsigned long size;
701
702 if (offset >= p->pack_size)
703 die("object offset outside of pack file");
704
705 pack = p->pack_base + offset;
706 c = *pack++;
707 offset++;
708 *type = (c >> 4) & 7;
709 size = c & 15;
01247d87 710 shift = 4;
a733cb60
LT
711 while (c & 0x80) {
712 if (offset >= p->pack_size)
713 die("object offset outside of pack file");
714 c = *pack++;
715 offset++;
01247d87
LT
716 size += (c & 0x7f) << shift;
717 shift += 7;
a733cb60
LT
718 }
719 *sizep = size;
720 return offset;
721}
722
ad8c80a5
JH
723void packed_object_info_detail(struct pack_entry *e,
724 char *type,
725 unsigned long *size,
726 unsigned long *store_size,
727 int *delta_chain_length,
728 unsigned char *base_sha1)
729{
730 struct packed_git *p = e->p;
731 unsigned long offset, left;
732 unsigned char *pack;
733 enum object_type kind;
734
735 offset = unpack_object_header(p, e->offset, &kind, size);
736 pack = p->pack_base + offset;
737 left = p->pack_size - offset;
738 if (kind != OBJ_DELTA)
739 *delta_chain_length = 0;
740 else {
741 int chain_length = 0;
742 memcpy(base_sha1, pack, 20);
743 do {
744 struct pack_entry base_ent;
745 unsigned long junk;
746
747 find_pack_entry_one(pack, &base_ent, p);
748 offset = unpack_object_header(p, base_ent.offset,
749 &kind, &junk);
750 pack = p->pack_base + offset;
751 chain_length++;
752 } while (kind == OBJ_DELTA);
753 *delta_chain_length = chain_length;
754 }
755 switch (kind) {
756 case OBJ_COMMIT:
757 strcpy(type, "commit");
758 break;
759 case OBJ_TREE:
760 strcpy(type, "tree");
761 break;
762 case OBJ_BLOB:
763 strcpy(type, "blob");
764 break;
765 case OBJ_TAG:
766 strcpy(type, "tag");
767 break;
768 default:
769 die("corrupted pack file");
770 }
771 *store_size = 0; /* notyet */
772}
773
1f688557
JH
774static int packed_object_info(struct pack_entry *entry,
775 char *type, unsigned long *sizep)
776{
777 struct packed_git *p = entry->p;
778 unsigned long offset, size, left;
779 unsigned char *pack;
a733cb60 780 enum object_type kind;
f9253394 781 int retval;
5db47c2b
JH
782
783 if (use_packed_git(p))
784 die("cannot map packed file");
785
a733cb60 786 offset = unpack_object_header(p, entry->offset, &kind, &size);
1f688557 787 pack = p->pack_base + offset;
a733cb60
LT
788 left = p->pack_size - offset;
789
790 switch (kind) {
791 case OBJ_DELTA:
f3bf9224 792 retval = packed_delta_info(pack, size, left, type, sizep, p);
f9253394
JH
793 unuse_packed_git(p);
794 return retval;
a733cb60 795 case OBJ_COMMIT:
1f688557
JH
796 strcpy(type, "commit");
797 break;
a733cb60 798 case OBJ_TREE:
1f688557
JH
799 strcpy(type, "tree");
800 break;
a733cb60 801 case OBJ_BLOB:
1f688557
JH
802 strcpy(type, "blob");
803 break;
a733cb60 804 case OBJ_TAG:
a69d0943
LT
805 strcpy(type, "tag");
806 break;
1f688557
JH
807 default:
808 die("corrupted pack file");
809 }
c62266f3
JH
810 if (sizep)
811 *sizep = size;
f9253394 812 unuse_packed_git(p);
1f688557
JH
813 return 0;
814}
815
816/* forward declaration for a mutually recursive function */
817static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
818
819static void *unpack_delta_entry(unsigned char *base_sha1,
820 unsigned long delta_size,
821 unsigned long left,
822 char *type,
f3bf9224
JH
823 unsigned long *sizep,
824 struct packed_git *p)
1f688557 825{
f3bf9224 826 struct pack_entry base_ent;
1f688557
JH
827 void *data, *delta_data, *result, *base;
828 unsigned long data_size, result_size, base_size;
829 z_stream stream;
830 int st;
831
832 if (left < 20)
833 die("truncated pack file");
834 data = base_sha1 + 20;
835 data_size = left - 20;
836 delta_data = xmalloc(delta_size);
837
838 memset(&stream, 0, sizeof(stream));
839
840 stream.next_in = data;
841 stream.avail_in = data_size;
842 stream.next_out = delta_data;
843 stream.avail_out = delta_size;
844
845 inflateInit(&stream);
846 st = inflate(&stream, Z_FINISH);
847 inflateEnd(&stream);
848 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
849 die("delta data unpack failed");
850
f3bf9224
JH
851 /* The base entry _must_ be in the same pack */
852 if (!find_pack_entry_one(base_sha1, &base_ent, p))
853 die("failed to find delta-pack base object %s",
854 sha1_to_hex(base_sha1));
855 base = unpack_entry_gently(&base_ent, type, &base_size);
1f688557
JH
856 if (!base)
857 die("failed to read delta-pack base object %s",
858 sha1_to_hex(base_sha1));
859 result = patch_delta(base, base_size,
860 delta_data, delta_size,
861 &result_size);
862 if (!result)
863 die("failed to apply delta");
864 free(delta_data);
865 free(base);
866 *sizep = result_size;
867 return result;
868}
869
870static void *unpack_non_delta_entry(unsigned char *data,
871 unsigned long size,
872 unsigned long left)
873{
874 int st;
875 z_stream stream;
4d235c80 876 unsigned char *buffer;
1f688557
JH
877
878 buffer = xmalloc(size + 1);
879 buffer[size] = 0;
880 memset(&stream, 0, sizeof(stream));
881 stream.next_in = data;
882 stream.avail_in = left;
883 stream.next_out = buffer;
884 stream.avail_out = size;
885
886 inflateInit(&stream);
887 st = inflate(&stream, Z_FINISH);
888 inflateEnd(&stream);
889 if ((st != Z_STREAM_END) || stream.total_out != size) {
890 free(buffer);
891 return NULL;
892 }
893
894 return buffer;
895}
896
897static void *unpack_entry(struct pack_entry *entry,
898 char *type, unsigned long *sizep)
899{
900 struct packed_git *p = entry->p;
f9253394 901 void *retval;
1f688557
JH
902
903 if (use_packed_git(p))
904 die("cannot map packed file");
f3bf9224
JH
905 retval = unpack_entry_gently(entry, type, sizep);
906 unuse_packed_git(p);
907 if (!retval)
908 die("corrupted pack file");
909 return retval;
910}
911
912/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
913void *unpack_entry_gently(struct pack_entry *entry,
914 char *type, unsigned long *sizep)
915{
916 struct packed_git *p = entry->p;
917 unsigned long offset, size, left;
918 unsigned char *pack;
919 enum object_type kind;
920 void *retval;
1f688557 921
a733cb60 922 offset = unpack_object_header(p, entry->offset, &kind, &size);
1f688557 923 pack = p->pack_base + offset;
a733cb60
LT
924 left = p->pack_size - offset;
925 switch (kind) {
926 case OBJ_DELTA:
f3bf9224 927 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
f9253394 928 return retval;
a733cb60 929 case OBJ_COMMIT:
1f688557
JH
930 strcpy(type, "commit");
931 break;
a733cb60 932 case OBJ_TREE:
1f688557
JH
933 strcpy(type, "tree");
934 break;
a733cb60 935 case OBJ_BLOB:
1f688557
JH
936 strcpy(type, "blob");
937 break;
a733cb60 938 case OBJ_TAG:
a69d0943
LT
939 strcpy(type, "tag");
940 break;
1f688557 941 default:
f3bf9224 942 return NULL;
1f688557
JH
943 }
944 *sizep = size;
f9253394 945 retval = unpack_non_delta_entry(pack, size, left);
f9253394 946 return retval;
1f688557
JH
947}
948
9a217f2a
JH
949int num_packed_objects(const struct packed_git *p)
950{
f9253394 951 /* See check_packed_git_idx() */
9a217f2a
JH
952 return (p->index_size - 20 - 20 - 4*256) / 24;
953}
954
955int nth_packed_object_sha1(const struct packed_git *p, int n,
956 unsigned char* sha1)
957{
958 void *index = p->index_base + 256;
959 if (n < 0 || num_packed_objects(p) <= n)
960 return -1;
961 memcpy(sha1, (index + 24 * n + 4), 20);
962 return 0;
963}
964
f3bf9224
JH
965int find_pack_entry_one(const unsigned char *sha1,
966 struct pack_entry *e, struct packed_git *p)
1f688557 967{
4d235c80 968 unsigned int *level1_ofs = p->index_base;
1f688557
JH
969 int hi = ntohl(level1_ofs[*sha1]);
970 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
971 void *index = p->index_base + 256;
972
973 do {
974 int mi = (lo + hi) / 2;
975 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
976 if (!cmp) {
977 e->offset = ntohl(*((int*)(index + 24 * mi)));
978 memcpy(e->sha1, sha1, 20);
979 e->p = p;
980 return 1;
981 }
982 if (cmp > 0)
983 hi = mi;
984 else
985 lo = mi+1;
986 } while (lo < hi);
987 return 0;
988}
989
990static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
991{
992 struct packed_git *p;
993 prepare_packed_git();
994
995 for (p = packed_git; p; p = p->next) {
f3bf9224 996 if (find_pack_entry_one(sha1, e, p))
1f688557
JH
997 return 1;
998 }
999 return 0;
1000}
1001
36e4d74a 1002int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1003{
36e4d74a 1004 int status;
65c2e0c3
JH
1005 unsigned long mapsize, size;
1006 void *map;
1007 z_stream stream;
36e4d74a 1008 char hdr[128];
65c2e0c3 1009
1f688557
JH
1010 map = map_sha1_file_internal(sha1, &mapsize, 0);
1011 if (!map) {
1012 struct pack_entry e;
1013
1014 if (!find_pack_entry(sha1, &e))
1015 return error("unable to find %s", sha1_to_hex(sha1));
c62266f3 1016 return packed_object_info(&e, type, sizep);
1f688557 1017 }
36e4d74a
JH
1018 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1019 status = error("unable to unpack %s header",
1020 sha1_to_hex(sha1));
1021 if (parse_sha1_header(hdr, type, &size) < 0)
1022 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1023 else {
65c2e0c3 1024 status = 0;
c62266f3
JH
1025 if (sizep)
1026 *sizep = size;
65c2e0c3 1027 }
65c2e0c3
JH
1028 inflateEnd(&stream);
1029 munmap(map, mapsize);
1030 return status;
1031}
1032
1f688557
JH
1033static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1034{
1035 struct pack_entry e;
1036
1037 if (!find_pack_entry(sha1, &e)) {
1038 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1039 return NULL;
1040 }
1041 return unpack_entry(&e, type, size);
1042}
1043
0fcfd160
LT
1044void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1045{
1046 unsigned long mapsize;
1047 void *map, *buf;
1048
1f688557 1049 map = map_sha1_file_internal(sha1, &mapsize, 0);
0fcfd160
LT
1050 if (map) {
1051 buf = unpack_sha1_file(map, mapsize, type, size);
1052 munmap(map, mapsize);
1053 return buf;
1054 }
1f688557 1055 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
1056}
1057
40469ee9 1058void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1059 const char *required_type,
40469ee9
JH
1060 unsigned long *size,
1061 unsigned char *actual_sha1_return)
f4913f91
JH
1062{
1063 char type[20];
1064 void *buffer;
1065 unsigned long isize;
40469ee9 1066 unsigned char actual_sha1[20];
f4913f91 1067
40469ee9
JH
1068 memcpy(actual_sha1, sha1, 20);
1069 while (1) {
1070 int ref_length = -1;
1071 const char *ref_type = NULL;
f4913f91 1072
40469ee9
JH
1073 buffer = read_sha1_file(actual_sha1, type, &isize);
1074 if (!buffer)
1075 return NULL;
1076 if (!strcmp(type, required_type)) {
1077 *size = isize;
1078 if (actual_sha1_return)
1079 memcpy(actual_sha1_return, actual_sha1, 20);
1080 return buffer;
1081 }
1082 /* Handle references */
1083 else if (!strcmp(type, "commit"))
1084 ref_type = "tree ";
1085 else if (!strcmp(type, "tag"))
1086 ref_type = "object ";
1087 else {
1088 free(buffer);
1089 return NULL;
1090 }
1091 ref_length = strlen(ref_type);
f4913f91 1092
40469ee9
JH
1093 if (memcmp(buffer, ref_type, ref_length) ||
1094 get_sha1_hex(buffer + ref_length, actual_sha1)) {
1095 free(buffer);
1096 return NULL;
1097 }
1098 /* Now we have the ID of the referred-to object in
1099 * actual_sha1. Check again. */
f4913f91 1100 }
f4913f91
JH
1101}
1102
d410c0f5
JH
1103static char *write_sha1_file_prepare(void *buf,
1104 unsigned long len,
1105 const char *type,
1106 unsigned char *sha1,
1107 unsigned char *hdr,
1108 int *hdrlen)
1109{
1110 SHA_CTX c;
1111
1112 /* Generate the header */
1113 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1114
1115 /* Sha1.. */
1116 SHA1_Init(&c);
1117 SHA1_Update(&c, hdr, *hdrlen);
1118 SHA1_Update(&c, buf, len);
1119 SHA1_Final(sha1, &c);
1120
1121 return sha1_file_name(sha1);
1122}
1123
bf0f910d 1124int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1125{
1126 int size;
bf0f910d 1127 unsigned char *compressed;
0fcfd160
LT
1128 z_stream stream;
1129 unsigned char sha1[20];
706bc531 1130 char *filename;
aac17941 1131 static char tmpfile[PATH_MAX];
bf0f910d 1132 unsigned char hdr[50];
aac17941 1133 int fd, hdrlen, ret;
a44c9a5e 1134
d410c0f5
JH
1135 /* Normally if we have it in the pack then we do not bother writing
1136 * it out into .git/objects/??/?{38} file.
1137 */
1138 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
706bc531
LT
1139 if (returnsha1)
1140 memcpy(returnsha1, sha1, 20);
d410c0f5
JH
1141 if (has_sha1_file(sha1))
1142 return 0;
aac17941
LT
1143 fd = open(filename, O_RDONLY);
1144 if (fd >= 0) {
706bc531 1145 /*
aac17941
LT
1146 * FIXME!!! We might do collision checking here, but we'd
1147 * need to uncompress the old file and check it. Later.
706bc531 1148 */
aac17941 1149 close(fd);
706bc531
LT
1150 return 0;
1151 }
1152
aac17941
LT
1153 if (errno != ENOENT) {
1154 fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
1155 return -1;
1156 }
1157
1158 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1159
aac17941
LT
1160 fd = mkstemp(tmpfile);
1161 if (fd < 0) {
1162 fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
1163 return -1;
1164 }
1165
0fcfd160
LT
1166 /* Set it up */
1167 memset(&stream, 0, sizeof(stream));
1168 deflateInit(&stream, Z_BEST_COMPRESSION);
a44c9a5e 1169 size = deflateBound(&stream, len+hdrlen);
812666c8 1170 compressed = xmalloc(size);
0fcfd160
LT
1171
1172 /* Compress it */
0fcfd160
LT
1173 stream.next_out = compressed;
1174 stream.avail_out = size;
a44c9a5e
LT
1175
1176 /* First header.. */
1177 stream.next_in = hdr;
1178 stream.avail_in = hdrlen;
1179 while (deflate(&stream, 0) == Z_OK)
6ffcee88 1180 /* nothing */;
a44c9a5e
LT
1181
1182 /* Then the data itself.. */
1183 stream.next_in = buf;
1184 stream.avail_in = len;
0fcfd160
LT
1185 while (deflate(&stream, Z_FINISH) == Z_OK)
1186 /* nothing */;
1187 deflateEnd(&stream);
1188 size = stream.total_out;
1189
706bc531
LT
1190 if (write(fd, compressed, size) != size)
1191 die("unable to write file");
aac17941 1192 fchmod(fd, 0444);
706bc531 1193 close(fd);
383f85b7 1194 free(compressed);
0fcfd160 1195
aac17941 1196 ret = link(tmpfile, filename);
a31c6d02 1197 if (ret < 0) {
aac17941 1198 ret = errno;
a31c6d02
LT
1199
1200 /*
1201 * Coda hack - coda doesn't like cross-directory links,
1202 * so we fall back to a rename, which will mean that it
1203 * won't be able to check collisions, but that's not a
1204 * big deal.
1205 *
1206 * When this succeeds, we just return 0. We have nothing
1207 * left to unlink.
1208 */
1209 if (ret == EXDEV && !rename(tmpfile, filename))
1210 return 0;
1211 }
aac17941
LT
1212 unlink(tmpfile);
1213 if (ret) {
1214 if (ret != EEXIST) {
1215 fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
0fcfd160 1216 return -1;
aac17941
LT
1217 }
1218 /* FIXME!!! Collision check here ? */
0fcfd160 1219 }
aac17941 1220
0fcfd160
LT
1221 return 0;
1222}
8237b185
DB
1223
1224int write_sha1_from_fd(const unsigned char *sha1, int fd)
1225{
1226 char *filename = sha1_file_name(sha1);
1227
1228 int local;
1229 z_stream stream;
1230 unsigned char real_sha1[20];
bf0f910d
BG
1231 unsigned char buf[4096];
1232 unsigned char discard[4096];
8237b185
DB
1233 int ret;
1234 SHA_CTX c;
1235
1236 local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
1237
1238 if (local < 0)
1239 return error("Couldn't open %s\n", filename);
1240
1241 memset(&stream, 0, sizeof(stream));
1242
1243 inflateInit(&stream);
1244
1245 SHA1_Init(&c);
1246
1247 do {
1248 ssize_t size;
1249 size = read(fd, buf, 4096);
1250 if (size <= 0) {
1251 close(local);
1252 unlink(filename);
1253 if (!size)
1254 return error("Connection closed?");
1255 perror("Reading from connection");
1256 return -1;
1257 }
1258 write(local, buf, size);
1259 stream.avail_in = size;
1260 stream.next_in = buf;
1261 do {
1262 stream.next_out = discard;
1263 stream.avail_out = sizeof(discard);
1264 ret = inflate(&stream, Z_SYNC_FLUSH);
1265 SHA1_Update(&c, discard, sizeof(discard) -
1266 stream.avail_out);
1267 } while (stream.avail_in && ret == Z_OK);
1268
1269 } while (ret == Z_OK);
1270 inflateEnd(&stream);
1271
1272 close(local);
1273 SHA1_Final(real_sha1, &c);
1274 if (ret != Z_STREAM_END) {
1275 unlink(filename);
1276 return error("File %s corrupted", sha1_to_hex(sha1));
1277 }
1278 if (memcmp(sha1, real_sha1, 20)) {
1279 unlink(filename);
1280 return error("File %s has bad hash\n", sha1_to_hex(sha1));
1281 }
1282
1283 return 0;
1284}
1285
dade09c2
LT
1286int has_sha1_pack(const unsigned char *sha1)
1287{
1288 struct pack_entry e;
1289 return find_pack_entry(sha1, &e);
1290}
1291
8237b185
DB
1292int has_sha1_file(const unsigned char *sha1)
1293{
8237b185 1294 struct stat st;
1f688557
JH
1295 struct pack_entry e;
1296
1297 if (find_sha1_file(sha1, &st))
1298 return 1;
1299 return find_pack_entry(sha1, &e);
8237b185 1300}
74400e71
JH
1301
1302int index_fd(unsigned char *sha1, int fd, struct stat *st)
1303{
74400e71 1304 unsigned long size = st->st_size;
aac17941
LT
1305 void *buf;
1306 int ret;
74400e71 1307
aac17941 1308 buf = "";
74400e71 1309 if (size)
aac17941 1310 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1311 close(fd);
aac17941 1312 if ((int)(long)buf == -1)
74400e71
JH
1313 return -1;
1314
aac17941
LT
1315 ret = write_sha1_file(buf, size, "blob", sha1);
1316 if (size)
1317 munmap(buf, size);
1318 return ret;
74400e71 1319}