Add "git_path()" and "head_ref()" helper functions.
[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
723c31fe 105char *git_path(const char *fmt, ...)
3c249c95
LT
106{
107 static char pathname[PATH_MAX];
723c31fe
LT
108 va_list args;
109 int len;
110
111 if (!git_dir)
112 setup_git_env();
113 len = strlen(git_dir);
114 if (len == 1 && *git_dir == '.')
115 len = 0;
116 if (len > PATH_MAX-100)
117 return "pad-path";
118 memcpy(pathname, git_dir, len);
119 if (len && git_dir[len-1] != '/')
120 pathname[len++] = '/';
121 va_start(args, fmt);
122 vsnprintf(pathname + len, sizeof(pathname) - len, fmt, args);
123 va_end(args);
124 return pathname;
125}
126
127int get_sha1(const char *str, unsigned char *sha1)
128{
35ad3382
LT
129 static const char *prefix[] = {
130 "",
131 "refs",
132 "refs/tags",
133 "refs/heads",
134 "refs/snap",
135 NULL
136 };
35ad3382 137 const char **p;
3c249c95
LT
138
139 if (!get_sha1_hex(str, sha1))
140 return 0;
35ad3382 141
35ad3382 142 for (p = prefix; *p; p++) {
723c31fe 143 char * pathname = git_path("%s/%s", *p, str);
35ad3382
LT
144 if (!get_sha1_file(pathname, sha1))
145 return 0;
146 }
147
3c249c95
LT
148 return -1;
149}
150
0fcfd160
LT
151char * sha1_to_hex(const unsigned char *sha1)
152{
153 static char buffer[50];
154 static const char hex[] = "0123456789abcdef";
155 char *buf = buffer;
156 int i;
157
158 for (i = 0; i < 20; i++) {
159 unsigned int val = *sha1++;
160 *buf++ = hex[val >> 4];
161 *buf++ = hex[val & 0xf];
162 }
163 return buffer;
164}
165
ace1534d
JH
166static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
167{
168 int i;
169 for (i = 0; i < 20; i++) {
170 static char hex[] = "0123456789abcdef";
171 unsigned int val = sha1[i];
172 char *pos = pathbuf + i*2 + (i > 0);
173 *pos++ = hex[val >> 4];
174 *pos = hex[val & 0xf];
175 }
176}
177
0fcfd160
LT
178/*
179 * NOTE! This returns a statically allocated buffer, so you have to be
180 * careful about using it. Do a "strdup()" if you need to save the
181 * filename.
ace1534d
JH
182 *
183 * Also note that this returns the location for creating. Reading
184 * SHA1 file can happen from any alternate directory listed in the
d19938ab 185 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 186 * the primary object database.
0fcfd160
LT
187 */
188char *sha1_file_name(const unsigned char *sha1)
189{
0fcfd160
LT
190 static char *name, *base;
191
192 if (!base) {
d19938ab 193 const char *sha1_file_directory = get_object_directory();
0fcfd160 194 int len = strlen(sha1_file_directory);
812666c8 195 base = xmalloc(len + 60);
0fcfd160
LT
196 memcpy(base, sha1_file_directory, len);
197 memset(base+len, 0, 60);
198 base[len] = '/';
199 base[len+3] = '/';
200 name = base + len + 1;
201 }
ace1534d 202 fill_sha1_path(name, sha1);
0fcfd160
LT
203 return base;
204}
205
9a217f2a 206struct alternate_object_database *alt_odb;
ace1534d 207
ddd5d056
JH
208/*
209 * Prepare alternate object database registry.
210 * alt_odb points at an array of struct alternate_object_database.
211 * This array is terminated with an element that has both its base
212 * and name set to NULL. alt_odb[n] comes from n'th non-empty
d19938ab 213 * element from colon separated ALTERNATE_DB_ENVIRONMENT environment
ddd5d056
JH
214 * variable, and its base points at a statically allocated buffer
215 * that contains "/the/directory/corresponding/to/.git/objects/...",
216 * while its name points just after the slash at the end of
217 * ".git/objects/" in the example above, and has enough space to hold
218 * 40-byte hex SHA1, an extra slash for the first level indirection,
219 * and the terminating NUL.
220 * This function allocates the alt_odb array and all the strings
221 * pointed by base fields of the array elements with one xmalloc();
222 * the string pool immediately follows the array.
223 */
9a217f2a 224void prepare_alt_odb(void)
ace1534d
JH
225{
226 int pass, totlen, i;
ace1534d 227 const char *cp, *last;
e99d59ff 228 char *op = NULL;
d19938ab 229 const char *alt = gitenv(ALTERNATE_DB_ENVIRONMENT) ? : "";
ace1534d 230
9a217f2a
JH
231 if (alt_odb)
232 return;
ddd5d056
JH
233 /* The first pass counts how large an area to allocate to
234 * hold the entire alt_odb structure, including array of
235 * structs and path buffers for them. The second pass fills
236 * the structure and prepares the path buffers for use by
237 * fill_sha1_path().
238 */
ace1534d
JH
239 for (totlen = pass = 0; pass < 2; pass++) {
240 last = alt;
241 i = 0;
242 do {
243 cp = strchr(last, ':') ? : last + strlen(last);
244 if (last != cp) {
245 /* 43 = 40-byte + 2 '/' + terminating NUL */
246 int pfxlen = cp - last;
247 int entlen = pfxlen + 43;
248 if (pass == 0)
249 totlen += entlen;
250 else {
251 alt_odb[i].base = op;
252 alt_odb[i].name = op + pfxlen + 1;
253 memcpy(op, last, pfxlen);
254 op[pfxlen] = op[pfxlen + 3] = '/';
255 op[entlen-1] = 0;
256 op += entlen;
257 }
258 i++;
259 }
260 while (*cp && *cp == ':')
261 cp++;
262 last = cp;
263 } while (*cp);
264 if (pass)
265 break;
ddd5d056 266 alt_odb = xmalloc(sizeof(*alt_odb) * (i + 1) + totlen);
e99d59ff 267 alt_odb[i].base = alt_odb[i].name = NULL;
ace1534d
JH
268 op = (char*)(&alt_odb[i+1]);
269 }
270}
271
272static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
273{
274 int i;
275 char *name = sha1_file_name(sha1);
276
277 if (!stat(name, st))
278 return name;
9a217f2a 279 prepare_alt_odb();
ace1534d
JH
280 for (i = 0; (name = alt_odb[i].name) != NULL; i++) {
281 fill_sha1_path(name, sha1);
282 if (!stat(alt_odb[i].base, st))
283 return alt_odb[i].base;
284 }
285 return NULL;
286}
287
1f688557
JH
288#define PACK_MAX_SZ (1<<26)
289static int pack_used_ctr;
290static unsigned long pack_mapped;
9a217f2a 291struct packed_git *packed_git;
1f688557 292
1f688557
JH
293static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
294 void **idx_map_)
295{
296 void *idx_map;
297 unsigned int *index;
298 unsigned long idx_size;
299 int nr, i;
300 int fd = open(path, O_RDONLY);
301 struct stat st;
302 if (fd < 0)
303 return -1;
304 if (fstat(fd, &st)) {
305 close(fd);
306 return -1;
307 }
308 idx_size = st.st_size;
309 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
310 close(fd);
311 if (idx_map == MAP_FAILED)
312 return -1;
313
314 index = idx_map;
4d235c80
LT
315 *idx_map_ = idx_map;
316 *idx_size_ = idx_size;
1f688557
JH
317
318 /* check index map */
f9253394 319 if (idx_size < 4*256 + 20 + 20)
1f688557
JH
320 return error("index file too small");
321 nr = 0;
322 for (i = 0; i < 256; i++) {
323 unsigned int n = ntohl(index[i]);
324 if (n < nr)
325 return error("non-monotonic index");
326 nr = n;
327 }
328
329 /*
330 * Total size:
331 * - 256 index entries 4 bytes each
332 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
333 * - 20-byte SHA1 of the packfile
334 * - 20-byte SHA1 file checksum
335 */
336 if (idx_size != 4*256 + nr * 24 + 20 + 20)
337 return error("wrong index file size");
338
1f688557
JH
339 return 0;
340}
341
f9253394 342static int unuse_one_packed_git(void)
1f688557 343{
f9253394
JH
344 struct packed_git *p, *lru = NULL;
345
346 for (p = packed_git; p; p = p->next) {
347 if (p->pack_use_cnt || !p->pack_base)
348 continue;
349 if (!lru || p->pack_last_used < lru->pack_last_used)
350 lru = p;
351 }
352 if (!lru)
353 return 0;
354 munmap(lru->pack_base, lru->pack_size);
355 lru->pack_base = NULL;
356 return 1;
357}
358
359void unuse_packed_git(struct packed_git *p)
360{
361 p->pack_use_cnt--;
1f688557
JH
362}
363
f9253394 364int use_packed_git(struct packed_git *p)
1f688557
JH
365{
366 if (!p->pack_base) {
367 int fd;
368 struct stat st;
369 void *map;
370
371 pack_mapped += p->pack_size;
f9253394
JH
372 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
373 ; /* nothing */
1f688557
JH
374 fd = open(p->pack_name, O_RDONLY);
375 if (fd < 0)
f9253394 376 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
377 if (fstat(fd, &st)) {
378 close(fd);
f9253394 379 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
380 }
381 if (st.st_size != p->pack_size)
f9253394 382 die("packfile %s size mismatch.", p->pack_name);
1f688557
JH
383 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
384 close(fd);
385 if (map == MAP_FAILED)
f9253394 386 die("packfile %s cannot be mapped.", p->pack_name);
1f688557 387 p->pack_base = map;
f9253394
JH
388
389 /* Check if the pack file matches with the index file.
390 * this is cheap.
391 */
392 if (memcmp((char*)(p->index_base) + p->index_size - 40,
393 p->pack_base + p->pack_size - 20, 20))
394 die("packfile %s does not match index.", p->pack_name);
1f688557
JH
395 }
396 p->pack_last_used = pack_used_ctr++;
f9253394 397 p->pack_use_cnt++;
1f688557
JH
398 return 0;
399}
400
f9253394 401struct packed_git *add_packed_git(char *path, int path_len)
1f688557
JH
402{
403 struct stat st;
404 struct packed_git *p;
405 unsigned long idx_size;
406 void *idx_map;
407
408 if (check_packed_git_idx(path, &idx_size, &idx_map))
409 return NULL;
410
411 /* do we have a corresponding .pack file? */
412 strcpy(path + path_len - 4, ".pack");
413 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
414 munmap(idx_map, idx_size);
415 return NULL;
416 }
417 /* ok, it looks sane as far as we can check without
418 * actually mapping the pack file.
419 */
420 p = xmalloc(sizeof(*p) + path_len + 2);
421 strcpy(p->pack_name, path);
422 p->index_size = idx_size;
423 p->pack_size = st.st_size;
424 p->index_base = idx_map;
425 p->next = NULL;
d85a4fee 426 p->pack_base = NULL;
1f688557 427 p->pack_last_used = 0;
f9253394 428 p->pack_use_cnt = 0;
1f688557
JH
429 return p;
430}
431
432static void prepare_packed_git_one(char *objdir)
433{
434 char path[PATH_MAX];
435 int len;
436 DIR *dir;
437 struct dirent *de;
438
439 sprintf(path, "%s/pack", objdir);
440 len = strlen(path);
441 dir = opendir(path);
442 if (!dir)
443 return;
444 path[len++] = '/';
445 while ((de = readdir(dir)) != NULL) {
446 int namelen = strlen(de->d_name);
447 struct packed_git *p;
448
449 if (strcmp(de->d_name + namelen - 4, ".idx"))
450 continue;
451
452 /* we have .idx. Is it a file we can map? */
453 strcpy(path + len, de->d_name);
454 p = add_packed_git(path, len + namelen);
455 if (!p)
456 continue;
457 p->next = packed_git;
458 packed_git = p;
459 }
460}
461
9a217f2a 462void prepare_packed_git(void)
1f688557
JH
463{
464 int i;
465 static int run_once = 0;
466
467 if (run_once++)
468 return;
469
470 prepare_packed_git_one(get_object_directory());
9a217f2a 471 prepare_alt_odb();
1f688557
JH
472 for (i = 0; alt_odb[i].base != NULL; i++) {
473 alt_odb[i].name[0] = 0;
474 prepare_packed_git_one(alt_odb[i].base);
475 }
476}
477
5d6ccf5c 478int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160 479{
d98b46f8 480 char header[100];
0fcfd160
LT
481 unsigned char real_sha1[20];
482 SHA_CTX c;
483
484 SHA1_Init(&c);
d98b46f8 485 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
0fcfd160
LT
486 SHA1_Update(&c, map, size);
487 SHA1_Final(real_sha1, &c);
488 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
489}
490
1f688557
JH
491static void *map_sha1_file_internal(const unsigned char *sha1,
492 unsigned long *size,
493 int say_error)
0fcfd160 494{
0fcfd160
LT
495 struct stat st;
496 void *map;
144bde78 497 int fd;
ace1534d
JH
498 char *filename = find_sha1_file(sha1, &st);
499
500 if (!filename) {
1f688557
JH
501 if (say_error)
502 error("cannot map sha1 file %s", sha1_to_hex(sha1));
ace1534d
JH
503 return NULL;
504 }
0fcfd160 505
144bde78 506 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 507 if (fd < 0) {
144bde78
LT
508 /* See if it works without O_NOATIME */
509 switch (sha1_file_open_flag) {
510 default:
511 fd = open(filename, O_RDONLY);
512 if (fd >= 0)
513 break;
514 /* Fallthrough */
515 case 0:
1f688557
JH
516 if (say_error)
517 perror(filename);
144bde78
LT
518 return NULL;
519 }
520
1f688557
JH
521 /* If it failed once, it will probably fail again.
522 * Stop using O_NOATIME
523 */
144bde78 524 sha1_file_open_flag = 0;
0fcfd160 525 }
0fcfd160
LT
526 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
527 close(fd);
528 if (-1 == (int)(long)map)
529 return NULL;
530 *size = st.st_size;
531 return map;
532}
533
1f688557
JH
534void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
535{
536 return map_sha1_file_internal(sha1, size, 1);
537}
538
c4483576
LT
539int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
540{
541 /* Get the data stream */
542 memset(stream, 0, sizeof(*stream));
543 stream->next_in = map;
544 stream->avail_in = mapsize;
545 stream->next_out = buffer;
546 stream->avail_out = size;
547
548 inflateInit(stream);
549 return inflate(stream, 0);
550}
551
6da4016a 552static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
5180cacc
LT
553{
554 int bytes = strlen(buffer) + 1;
d565b341 555 unsigned char *buf = xmalloc(1+size);
5180cacc
LT
556
557 memcpy(buf, buffer + bytes, stream->total_out - bytes);
558 bytes = stream->total_out - bytes;
559 if (bytes < size) {
560 stream->next_out = buf + bytes;
561 stream->avail_out = size - bytes;
562 while (inflate(stream, Z_FINISH) == Z_OK)
563 /* nothing */;
564 }
565 buf[size] = 0;
566 inflateEnd(stream);
567 return buf;
568}
569
570/*
571 * We used to just use "sscanf()", but that's actually way
572 * too permissive for what we want to check. So do an anal
573 * object header parse by hand.
574 */
575int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
576{
577 int i;
578 unsigned long size;
579
580 /*
581 * The type can be at most ten bytes (including the
582 * terminating '\0' that we add), and is followed by
583 * a space.
584 */
585 i = 10;
586 for (;;) {
587 char c = *hdr++;
588 if (c == ' ')
589 break;
590 if (!--i)
591 return -1;
592 *type++ = c;
593 }
594 *type = 0;
595
596 /*
597 * The length must follow immediately, and be in canonical
598 * decimal format (ie "010" is not valid).
599 */
600 size = *hdr++ - '0';
601 if (size > 9)
602 return -1;
603 if (size) {
604 for (;;) {
605 unsigned long c = *hdr - '0';
606 if (c > 9)
607 break;
608 hdr++;
609 size = size * 10 + c;
610 }
611 }
612 *sizep = size;
613
614 /*
615 * The length must be followed by a zero byte
616 */
617 return *hdr ? -1 : 0;
618}
619
0fcfd160
LT
620void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
621{
5180cacc 622 int ret;
0fcfd160 623 z_stream stream;
5180cacc 624 char hdr[8192];
0fcfd160 625
5180cacc
LT
626 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
627 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
628 return NULL;
629
5180cacc 630 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
631}
632
f3bf9224
JH
633/* forward declaration for a mutually recursive function */
634static int packed_object_info(struct pack_entry *entry,
635 char *type, unsigned long *sizep);
636
5db47c2b
JH
637static int packed_delta_info(unsigned char *base_sha1,
638 unsigned long delta_size,
639 unsigned long left,
640 char *type,
f3bf9224
JH
641 unsigned long *sizep,
642 struct packed_git *p)
5db47c2b 643{
f3bf9224
JH
644 struct pack_entry base_ent;
645
5db47c2b
JH
646 if (left < 20)
647 die("truncated pack file");
5db47c2b 648
f3bf9224
JH
649 /* The base entry _must_ be in the same pack */
650 if (!find_pack_entry_one(base_sha1, &base_ent, p))
651 die("failed to find delta-pack base object %s",
652 sha1_to_hex(base_sha1));
653
c62266f3
JH
654 /* We choose to only get the type of the base object and
655 * ignore potentially corrupt pack file that expects the delta
656 * based on a base with a wrong size. This saves tons of
657 * inflate() calls.
658 */
5db47c2b 659
f3bf9224 660 if (packed_object_info(&base_ent, type, NULL))
c62266f3 661 die("cannot get info for delta-pack base");
5db47c2b 662
c62266f3
JH
663 if (sizep) {
664 const unsigned char *data;
665 unsigned char delta_head[64];
666 unsigned long result_size;
667 z_stream stream;
668 int st;
669
670 memset(&stream, 0, sizeof(stream));
671
672 data = stream.next_in = base_sha1 + 20;
673 stream.avail_in = left - 20;
674 stream.next_out = delta_head;
675 stream.avail_out = sizeof(delta_head);
676
677 inflateInit(&stream);
678 st = inflate(&stream, Z_FINISH);
679 inflateEnd(&stream);
680 if ((st != Z_STREAM_END) &&
681 stream.total_out != sizeof(delta_head))
682 die("delta data unpack-initial failed");
683
684 /* Examine the initial part of the delta to figure out
685 * the result size.
686 */
687 data = delta_head;
688 get_delta_hdr_size(&data); /* ignore base size */
5db47c2b 689
c62266f3
JH
690 /* Read the result size */
691 result_size = get_delta_hdr_size(&data);
692 *sizep = result_size;
693 }
5db47c2b
JH
694 return 0;
695}
696
a733cb60
LT
697static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
698 enum object_type *type, unsigned long *sizep)
699{
01247d87 700 unsigned shift;
a733cb60
LT
701 unsigned char *pack, c;
702 unsigned long size;
703
704 if (offset >= p->pack_size)
705 die("object offset outside of pack file");
706
707 pack = p->pack_base + offset;
708 c = *pack++;
709 offset++;
710 *type = (c >> 4) & 7;
711 size = c & 15;
01247d87 712 shift = 4;
a733cb60
LT
713 while (c & 0x80) {
714 if (offset >= p->pack_size)
715 die("object offset outside of pack file");
716 c = *pack++;
717 offset++;
01247d87
LT
718 size += (c & 0x7f) << shift;
719 shift += 7;
a733cb60
LT
720 }
721 *sizep = size;
722 return offset;
723}
724
ad8c80a5
JH
725void packed_object_info_detail(struct pack_entry *e,
726 char *type,
727 unsigned long *size,
728 unsigned long *store_size,
729 int *delta_chain_length,
730 unsigned char *base_sha1)
731{
732 struct packed_git *p = e->p;
733 unsigned long offset, left;
734 unsigned char *pack;
735 enum object_type kind;
736
737 offset = unpack_object_header(p, e->offset, &kind, size);
738 pack = p->pack_base + offset;
739 left = p->pack_size - offset;
740 if (kind != OBJ_DELTA)
741 *delta_chain_length = 0;
742 else {
743 int chain_length = 0;
744 memcpy(base_sha1, pack, 20);
745 do {
746 struct pack_entry base_ent;
747 unsigned long junk;
748
749 find_pack_entry_one(pack, &base_ent, p);
750 offset = unpack_object_header(p, base_ent.offset,
751 &kind, &junk);
752 pack = p->pack_base + offset;
753 chain_length++;
754 } while (kind == OBJ_DELTA);
755 *delta_chain_length = chain_length;
756 }
757 switch (kind) {
758 case OBJ_COMMIT:
759 strcpy(type, "commit");
760 break;
761 case OBJ_TREE:
762 strcpy(type, "tree");
763 break;
764 case OBJ_BLOB:
765 strcpy(type, "blob");
766 break;
767 case OBJ_TAG:
768 strcpy(type, "tag");
769 break;
770 default:
771 die("corrupted pack file");
772 }
773 *store_size = 0; /* notyet */
774}
775
1f688557
JH
776static int packed_object_info(struct pack_entry *entry,
777 char *type, unsigned long *sizep)
778{
779 struct packed_git *p = entry->p;
780 unsigned long offset, size, left;
781 unsigned char *pack;
a733cb60 782 enum object_type kind;
f9253394 783 int retval;
5db47c2b
JH
784
785 if (use_packed_git(p))
786 die("cannot map packed file");
787
a733cb60 788 offset = unpack_object_header(p, entry->offset, &kind, &size);
1f688557 789 pack = p->pack_base + offset;
a733cb60
LT
790 left = p->pack_size - offset;
791
792 switch (kind) {
793 case OBJ_DELTA:
f3bf9224 794 retval = packed_delta_info(pack, size, left, type, sizep, p);
f9253394
JH
795 unuse_packed_git(p);
796 return retval;
a733cb60 797 case OBJ_COMMIT:
1f688557
JH
798 strcpy(type, "commit");
799 break;
a733cb60 800 case OBJ_TREE:
1f688557
JH
801 strcpy(type, "tree");
802 break;
a733cb60 803 case OBJ_BLOB:
1f688557
JH
804 strcpy(type, "blob");
805 break;
a733cb60 806 case OBJ_TAG:
a69d0943
LT
807 strcpy(type, "tag");
808 break;
1f688557
JH
809 default:
810 die("corrupted pack file");
811 }
c62266f3
JH
812 if (sizep)
813 *sizep = size;
f9253394 814 unuse_packed_git(p);
1f688557
JH
815 return 0;
816}
817
818/* forward declaration for a mutually recursive function */
819static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
820
821static void *unpack_delta_entry(unsigned char *base_sha1,
822 unsigned long delta_size,
823 unsigned long left,
824 char *type,
f3bf9224
JH
825 unsigned long *sizep,
826 struct packed_git *p)
1f688557 827{
f3bf9224 828 struct pack_entry base_ent;
1f688557
JH
829 void *data, *delta_data, *result, *base;
830 unsigned long data_size, result_size, base_size;
831 z_stream stream;
832 int st;
833
834 if (left < 20)
835 die("truncated pack file");
836 data = base_sha1 + 20;
837 data_size = left - 20;
838 delta_data = xmalloc(delta_size);
839
840 memset(&stream, 0, sizeof(stream));
841
842 stream.next_in = data;
843 stream.avail_in = data_size;
844 stream.next_out = delta_data;
845 stream.avail_out = delta_size;
846
847 inflateInit(&stream);
848 st = inflate(&stream, Z_FINISH);
849 inflateEnd(&stream);
850 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
851 die("delta data unpack failed");
852
f3bf9224
JH
853 /* The base entry _must_ be in the same pack */
854 if (!find_pack_entry_one(base_sha1, &base_ent, p))
855 die("failed to find delta-pack base object %s",
856 sha1_to_hex(base_sha1));
857 base = unpack_entry_gently(&base_ent, type, &base_size);
1f688557
JH
858 if (!base)
859 die("failed to read delta-pack base object %s",
860 sha1_to_hex(base_sha1));
861 result = patch_delta(base, base_size,
862 delta_data, delta_size,
863 &result_size);
864 if (!result)
865 die("failed to apply delta");
866 free(delta_data);
867 free(base);
868 *sizep = result_size;
869 return result;
870}
871
872static void *unpack_non_delta_entry(unsigned char *data,
873 unsigned long size,
874 unsigned long left)
875{
876 int st;
877 z_stream stream;
4d235c80 878 unsigned char *buffer;
1f688557
JH
879
880 buffer = xmalloc(size + 1);
881 buffer[size] = 0;
882 memset(&stream, 0, sizeof(stream));
883 stream.next_in = data;
884 stream.avail_in = left;
885 stream.next_out = buffer;
886 stream.avail_out = size;
887
888 inflateInit(&stream);
889 st = inflate(&stream, Z_FINISH);
890 inflateEnd(&stream);
891 if ((st != Z_STREAM_END) || stream.total_out != size) {
892 free(buffer);
893 return NULL;
894 }
895
896 return buffer;
897}
898
899static void *unpack_entry(struct pack_entry *entry,
900 char *type, unsigned long *sizep)
901{
902 struct packed_git *p = entry->p;
f9253394 903 void *retval;
1f688557
JH
904
905 if (use_packed_git(p))
906 die("cannot map packed file");
f3bf9224
JH
907 retval = unpack_entry_gently(entry, type, sizep);
908 unuse_packed_git(p);
909 if (!retval)
910 die("corrupted pack file");
911 return retval;
912}
913
914/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
915void *unpack_entry_gently(struct pack_entry *entry,
916 char *type, unsigned long *sizep)
917{
918 struct packed_git *p = entry->p;
919 unsigned long offset, size, left;
920 unsigned char *pack;
921 enum object_type kind;
922 void *retval;
1f688557 923
a733cb60 924 offset = unpack_object_header(p, entry->offset, &kind, &size);
1f688557 925 pack = p->pack_base + offset;
a733cb60
LT
926 left = p->pack_size - offset;
927 switch (kind) {
928 case OBJ_DELTA:
f3bf9224 929 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
f9253394 930 return retval;
a733cb60 931 case OBJ_COMMIT:
1f688557
JH
932 strcpy(type, "commit");
933 break;
a733cb60 934 case OBJ_TREE:
1f688557
JH
935 strcpy(type, "tree");
936 break;
a733cb60 937 case OBJ_BLOB:
1f688557
JH
938 strcpy(type, "blob");
939 break;
a733cb60 940 case OBJ_TAG:
a69d0943
LT
941 strcpy(type, "tag");
942 break;
1f688557 943 default:
f3bf9224 944 return NULL;
1f688557
JH
945 }
946 *sizep = size;
f9253394 947 retval = unpack_non_delta_entry(pack, size, left);
f9253394 948 return retval;
1f688557
JH
949}
950
9a217f2a
JH
951int num_packed_objects(const struct packed_git *p)
952{
f9253394 953 /* See check_packed_git_idx() */
9a217f2a
JH
954 return (p->index_size - 20 - 20 - 4*256) / 24;
955}
956
957int nth_packed_object_sha1(const struct packed_git *p, int n,
958 unsigned char* sha1)
959{
960 void *index = p->index_base + 256;
961 if (n < 0 || num_packed_objects(p) <= n)
962 return -1;
963 memcpy(sha1, (index + 24 * n + 4), 20);
964 return 0;
965}
966
f3bf9224
JH
967int find_pack_entry_one(const unsigned char *sha1,
968 struct pack_entry *e, struct packed_git *p)
1f688557 969{
4d235c80 970 unsigned int *level1_ofs = p->index_base;
1f688557
JH
971 int hi = ntohl(level1_ofs[*sha1]);
972 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
973 void *index = p->index_base + 256;
974
975 do {
976 int mi = (lo + hi) / 2;
977 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
978 if (!cmp) {
979 e->offset = ntohl(*((int*)(index + 24 * mi)));
980 memcpy(e->sha1, sha1, 20);
981 e->p = p;
982 return 1;
983 }
984 if (cmp > 0)
985 hi = mi;
986 else
987 lo = mi+1;
988 } while (lo < hi);
989 return 0;
990}
991
992static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
993{
994 struct packed_git *p;
995 prepare_packed_git();
996
997 for (p = packed_git; p; p = p->next) {
f3bf9224 998 if (find_pack_entry_one(sha1, e, p))
1f688557
JH
999 return 1;
1000 }
1001 return 0;
1002}
1003
36e4d74a 1004int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1005{
36e4d74a 1006 int status;
65c2e0c3
JH
1007 unsigned long mapsize, size;
1008 void *map;
1009 z_stream stream;
36e4d74a 1010 char hdr[128];
65c2e0c3 1011
1f688557
JH
1012 map = map_sha1_file_internal(sha1, &mapsize, 0);
1013 if (!map) {
1014 struct pack_entry e;
1015
1016 if (!find_pack_entry(sha1, &e))
1017 return error("unable to find %s", sha1_to_hex(sha1));
c62266f3 1018 return packed_object_info(&e, type, sizep);
1f688557 1019 }
36e4d74a
JH
1020 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1021 status = error("unable to unpack %s header",
1022 sha1_to_hex(sha1));
1023 if (parse_sha1_header(hdr, type, &size) < 0)
1024 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1025 else {
65c2e0c3 1026 status = 0;
c62266f3
JH
1027 if (sizep)
1028 *sizep = size;
65c2e0c3 1029 }
65c2e0c3
JH
1030 inflateEnd(&stream);
1031 munmap(map, mapsize);
1032 return status;
1033}
1034
1f688557
JH
1035static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1036{
1037 struct pack_entry e;
1038
1039 if (!find_pack_entry(sha1, &e)) {
1040 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1041 return NULL;
1042 }
1043 return unpack_entry(&e, type, size);
1044}
1045
0fcfd160
LT
1046void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1047{
1048 unsigned long mapsize;
1049 void *map, *buf;
1050
1f688557 1051 map = map_sha1_file_internal(sha1, &mapsize, 0);
0fcfd160
LT
1052 if (map) {
1053 buf = unpack_sha1_file(map, mapsize, type, size);
1054 munmap(map, mapsize);
1055 return buf;
1056 }
1f688557 1057 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
1058}
1059
40469ee9 1060void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1061 const char *required_type,
40469ee9
JH
1062 unsigned long *size,
1063 unsigned char *actual_sha1_return)
f4913f91
JH
1064{
1065 char type[20];
1066 void *buffer;
1067 unsigned long isize;
40469ee9 1068 unsigned char actual_sha1[20];
f4913f91 1069
40469ee9
JH
1070 memcpy(actual_sha1, sha1, 20);
1071 while (1) {
1072 int ref_length = -1;
1073 const char *ref_type = NULL;
f4913f91 1074
40469ee9
JH
1075 buffer = read_sha1_file(actual_sha1, type, &isize);
1076 if (!buffer)
1077 return NULL;
1078 if (!strcmp(type, required_type)) {
1079 *size = isize;
1080 if (actual_sha1_return)
1081 memcpy(actual_sha1_return, actual_sha1, 20);
1082 return buffer;
1083 }
1084 /* Handle references */
1085 else if (!strcmp(type, "commit"))
1086 ref_type = "tree ";
1087 else if (!strcmp(type, "tag"))
1088 ref_type = "object ";
1089 else {
1090 free(buffer);
1091 return NULL;
1092 }
1093 ref_length = strlen(ref_type);
f4913f91 1094
40469ee9
JH
1095 if (memcmp(buffer, ref_type, ref_length) ||
1096 get_sha1_hex(buffer + ref_length, actual_sha1)) {
1097 free(buffer);
1098 return NULL;
1099 }
1100 /* Now we have the ID of the referred-to object in
1101 * actual_sha1. Check again. */
f4913f91 1102 }
f4913f91
JH
1103}
1104
d410c0f5
JH
1105static char *write_sha1_file_prepare(void *buf,
1106 unsigned long len,
1107 const char *type,
1108 unsigned char *sha1,
1109 unsigned char *hdr,
1110 int *hdrlen)
1111{
1112 SHA_CTX c;
1113
1114 /* Generate the header */
1115 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1116
1117 /* Sha1.. */
1118 SHA1_Init(&c);
1119 SHA1_Update(&c, hdr, *hdrlen);
1120 SHA1_Update(&c, buf, len);
1121 SHA1_Final(sha1, &c);
1122
1123 return sha1_file_name(sha1);
1124}
1125
bf0f910d 1126int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1127{
1128 int size;
bf0f910d 1129 unsigned char *compressed;
0fcfd160
LT
1130 z_stream stream;
1131 unsigned char sha1[20];
706bc531 1132 char *filename;
aac17941 1133 static char tmpfile[PATH_MAX];
bf0f910d 1134 unsigned char hdr[50];
aac17941 1135 int fd, hdrlen, ret;
a44c9a5e 1136
d410c0f5
JH
1137 /* Normally if we have it in the pack then we do not bother writing
1138 * it out into .git/objects/??/?{38} file.
1139 */
1140 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
706bc531
LT
1141 if (returnsha1)
1142 memcpy(returnsha1, sha1, 20);
d410c0f5
JH
1143 if (has_sha1_file(sha1))
1144 return 0;
aac17941
LT
1145 fd = open(filename, O_RDONLY);
1146 if (fd >= 0) {
706bc531 1147 /*
aac17941
LT
1148 * FIXME!!! We might do collision checking here, but we'd
1149 * need to uncompress the old file and check it. Later.
706bc531 1150 */
aac17941 1151 close(fd);
706bc531
LT
1152 return 0;
1153 }
1154
aac17941
LT
1155 if (errno != ENOENT) {
1156 fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
1157 return -1;
1158 }
1159
1160 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1161
aac17941
LT
1162 fd = mkstemp(tmpfile);
1163 if (fd < 0) {
1164 fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
1165 return -1;
1166 }
1167
0fcfd160
LT
1168 /* Set it up */
1169 memset(&stream, 0, sizeof(stream));
1170 deflateInit(&stream, Z_BEST_COMPRESSION);
a44c9a5e 1171 size = deflateBound(&stream, len+hdrlen);
812666c8 1172 compressed = xmalloc(size);
0fcfd160
LT
1173
1174 /* Compress it */
0fcfd160
LT
1175 stream.next_out = compressed;
1176 stream.avail_out = size;
a44c9a5e
LT
1177
1178 /* First header.. */
1179 stream.next_in = hdr;
1180 stream.avail_in = hdrlen;
1181 while (deflate(&stream, 0) == Z_OK)
6ffcee88 1182 /* nothing */;
a44c9a5e
LT
1183
1184 /* Then the data itself.. */
1185 stream.next_in = buf;
1186 stream.avail_in = len;
0fcfd160
LT
1187 while (deflate(&stream, Z_FINISH) == Z_OK)
1188 /* nothing */;
1189 deflateEnd(&stream);
1190 size = stream.total_out;
1191
706bc531
LT
1192 if (write(fd, compressed, size) != size)
1193 die("unable to write file");
aac17941 1194 fchmod(fd, 0444);
706bc531 1195 close(fd);
383f85b7 1196 free(compressed);
0fcfd160 1197
aac17941 1198 ret = link(tmpfile, filename);
a31c6d02 1199 if (ret < 0) {
aac17941 1200 ret = errno;
a31c6d02
LT
1201
1202 /*
1203 * Coda hack - coda doesn't like cross-directory links,
1204 * so we fall back to a rename, which will mean that it
1205 * won't be able to check collisions, but that's not a
1206 * big deal.
1207 *
1208 * When this succeeds, we just return 0. We have nothing
1209 * left to unlink.
1210 */
1211 if (ret == EXDEV && !rename(tmpfile, filename))
1212 return 0;
1213 }
aac17941
LT
1214 unlink(tmpfile);
1215 if (ret) {
1216 if (ret != EEXIST) {
1217 fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
0fcfd160 1218 return -1;
aac17941
LT
1219 }
1220 /* FIXME!!! Collision check here ? */
0fcfd160 1221 }
aac17941 1222
0fcfd160
LT
1223 return 0;
1224}
8237b185
DB
1225
1226int write_sha1_from_fd(const unsigned char *sha1, int fd)
1227{
1228 char *filename = sha1_file_name(sha1);
1229
1230 int local;
1231 z_stream stream;
1232 unsigned char real_sha1[20];
bf0f910d
BG
1233 unsigned char buf[4096];
1234 unsigned char discard[4096];
8237b185
DB
1235 int ret;
1236 SHA_CTX c;
1237
1238 local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
1239
1240 if (local < 0)
1241 return error("Couldn't open %s\n", filename);
1242
1243 memset(&stream, 0, sizeof(stream));
1244
1245 inflateInit(&stream);
1246
1247 SHA1_Init(&c);
1248
1249 do {
1250 ssize_t size;
1251 size = read(fd, buf, 4096);
1252 if (size <= 0) {
1253 close(local);
1254 unlink(filename);
1255 if (!size)
1256 return error("Connection closed?");
1257 perror("Reading from connection");
1258 return -1;
1259 }
1260 write(local, buf, size);
1261 stream.avail_in = size;
1262 stream.next_in = buf;
1263 do {
1264 stream.next_out = discard;
1265 stream.avail_out = sizeof(discard);
1266 ret = inflate(&stream, Z_SYNC_FLUSH);
1267 SHA1_Update(&c, discard, sizeof(discard) -
1268 stream.avail_out);
1269 } while (stream.avail_in && ret == Z_OK);
1270
1271 } while (ret == Z_OK);
1272 inflateEnd(&stream);
1273
1274 close(local);
1275 SHA1_Final(real_sha1, &c);
1276 if (ret != Z_STREAM_END) {
1277 unlink(filename);
1278 return error("File %s corrupted", sha1_to_hex(sha1));
1279 }
1280 if (memcmp(sha1, real_sha1, 20)) {
1281 unlink(filename);
1282 return error("File %s has bad hash\n", sha1_to_hex(sha1));
1283 }
1284
1285 return 0;
1286}
1287
dade09c2
LT
1288int has_sha1_pack(const unsigned char *sha1)
1289{
1290 struct pack_entry e;
1291 return find_pack_entry(sha1, &e);
1292}
1293
8237b185
DB
1294int has_sha1_file(const unsigned char *sha1)
1295{
8237b185 1296 struct stat st;
1f688557
JH
1297 struct pack_entry e;
1298
1299 if (find_sha1_file(sha1, &st))
1300 return 1;
1301 return find_pack_entry(sha1, &e);
8237b185 1302}
74400e71
JH
1303
1304int index_fd(unsigned char *sha1, int fd, struct stat *st)
1305{
74400e71 1306 unsigned long size = st->st_size;
aac17941
LT
1307 void *buf;
1308 int ret;
74400e71 1309
aac17941 1310 buf = "";
74400e71 1311 if (size)
aac17941 1312 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1313 close(fd);
aac17941 1314 if ((int)(long)buf == -1)
74400e71
JH
1315 return -1;
1316
aac17941
LT
1317 ret = write_sha1_file(buf, size, "blob", sha1);
1318 if (size)
1319 munmap(buf, size);
1320 return ret;
74400e71 1321}