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