[PATCH] Fixlets on top of Nico's clean-up.
[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
JH
274
275struct pack_entry {
276 unsigned int offset;
277 unsigned char sha1[20];
278 struct packed_git *p;
279};
280
281static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
282 void **idx_map_)
283{
284 void *idx_map;
285 unsigned int *index;
286 unsigned long idx_size;
287 int nr, i;
288 int fd = open(path, O_RDONLY);
289 struct stat st;
290 if (fd < 0)
291 return -1;
292 if (fstat(fd, &st)) {
293 close(fd);
294 return -1;
295 }
296 idx_size = st.st_size;
297 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
298 close(fd);
299 if (idx_map == MAP_FAILED)
300 return -1;
301
302 index = idx_map;
303
304 /* check index map */
305 if (idx_size < 4*256 + 20)
306 return error("index file too small");
307 nr = 0;
308 for (i = 0; i < 256; i++) {
309 unsigned int n = ntohl(index[i]);
310 if (n < nr)
311 return error("non-monotonic index");
312 nr = n;
313 }
314
315 /*
316 * Total size:
317 * - 256 index entries 4 bytes each
318 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
319 * - 20-byte SHA1 of the packfile
320 * - 20-byte SHA1 file checksum
321 */
322 if (idx_size != 4*256 + nr * 24 + 20 + 20)
323 return error("wrong index file size");
324
325 *idx_map_ = idx_map;
326 *idx_size_ = idx_size;
327 return 0;
328}
329
330static void unuse_one_packed_git(void)
331{
332 /* NOTYET */
333}
334
335static int use_packed_git(struct packed_git *p)
336{
337 if (!p->pack_base) {
338 int fd;
339 struct stat st;
340 void *map;
341
342 pack_mapped += p->pack_size;
343 while (PACK_MAX_SZ < pack_mapped)
344 unuse_one_packed_git();
345 fd = open(p->pack_name, O_RDONLY);
346 if (fd < 0)
347 return -1;
348 if (fstat(fd, &st)) {
349 close(fd);
350 return -1;
351 }
352 if (st.st_size != p->pack_size)
353 return -1;
354 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
355 close(fd);
356 if (map == MAP_FAILED)
357 return -1;
358 p->pack_base = map;
359 }
360 p->pack_last_used = pack_used_ctr++;
361 return 0;
362}
363
364static struct packed_git *add_packed_git(char *path, int path_len)
365{
366 struct stat st;
367 struct packed_git *p;
368 unsigned long idx_size;
369 void *idx_map;
370
371 if (check_packed_git_idx(path, &idx_size, &idx_map))
372 return NULL;
373
374 /* do we have a corresponding .pack file? */
375 strcpy(path + path_len - 4, ".pack");
376 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
377 munmap(idx_map, idx_size);
378 return NULL;
379 }
380 /* ok, it looks sane as far as we can check without
381 * actually mapping the pack file.
382 */
383 p = xmalloc(sizeof(*p) + path_len + 2);
384 strcpy(p->pack_name, path);
385 p->index_size = idx_size;
386 p->pack_size = st.st_size;
387 p->index_base = idx_map;
388 p->next = NULL;
d85a4fee 389 p->pack_base = NULL;
1f688557
JH
390 p->pack_last_used = 0;
391 return p;
392}
393
394static void prepare_packed_git_one(char *objdir)
395{
396 char path[PATH_MAX];
397 int len;
398 DIR *dir;
399 struct dirent *de;
400
401 sprintf(path, "%s/pack", objdir);
402 len = strlen(path);
403 dir = opendir(path);
404 if (!dir)
405 return;
406 path[len++] = '/';
407 while ((de = readdir(dir)) != NULL) {
408 int namelen = strlen(de->d_name);
409 struct packed_git *p;
410
411 if (strcmp(de->d_name + namelen - 4, ".idx"))
412 continue;
413
414 /* we have .idx. Is it a file we can map? */
415 strcpy(path + len, de->d_name);
416 p = add_packed_git(path, len + namelen);
417 if (!p)
418 continue;
419 p->next = packed_git;
420 packed_git = p;
421 }
422}
423
9a217f2a 424void prepare_packed_git(void)
1f688557
JH
425{
426 int i;
427 static int run_once = 0;
428
429 if (run_once++)
430 return;
431
432 prepare_packed_git_one(get_object_directory());
9a217f2a 433 prepare_alt_odb();
1f688557
JH
434 for (i = 0; alt_odb[i].base != NULL; i++) {
435 alt_odb[i].name[0] = 0;
436 prepare_packed_git_one(alt_odb[i].base);
437 }
438}
439
5d6ccf5c 440int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160 441{
d98b46f8 442 char header[100];
0fcfd160
LT
443 unsigned char real_sha1[20];
444 SHA_CTX c;
445
446 SHA1_Init(&c);
d98b46f8 447 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
0fcfd160
LT
448 SHA1_Update(&c, map, size);
449 SHA1_Final(real_sha1, &c);
450 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
451}
452
1f688557
JH
453static void *map_sha1_file_internal(const unsigned char *sha1,
454 unsigned long *size,
455 int say_error)
0fcfd160 456{
0fcfd160
LT
457 struct stat st;
458 void *map;
144bde78 459 int fd;
ace1534d
JH
460 char *filename = find_sha1_file(sha1, &st);
461
462 if (!filename) {
1f688557
JH
463 if (say_error)
464 error("cannot map sha1 file %s", sha1_to_hex(sha1));
ace1534d
JH
465 return NULL;
466 }
0fcfd160 467
144bde78 468 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 469 if (fd < 0) {
144bde78
LT
470 /* See if it works without O_NOATIME */
471 switch (sha1_file_open_flag) {
472 default:
473 fd = open(filename, O_RDONLY);
474 if (fd >= 0)
475 break;
476 /* Fallthrough */
477 case 0:
1f688557
JH
478 if (say_error)
479 perror(filename);
144bde78
LT
480 return NULL;
481 }
482
1f688557
JH
483 /* If it failed once, it will probably fail again.
484 * Stop using O_NOATIME
485 */
144bde78 486 sha1_file_open_flag = 0;
0fcfd160 487 }
0fcfd160
LT
488 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
489 close(fd);
490 if (-1 == (int)(long)map)
491 return NULL;
492 *size = st.st_size;
493 return map;
494}
495
1f688557
JH
496void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
497{
498 return map_sha1_file_internal(sha1, size, 1);
499}
500
c4483576
LT
501int unpack_sha1_header(z_stream *stream, void *map, unsigned long mapsize, void *buffer, unsigned long size)
502{
503 /* Get the data stream */
504 memset(stream, 0, sizeof(*stream));
505 stream->next_in = map;
506 stream->avail_in = mapsize;
507 stream->next_out = buffer;
508 stream->avail_out = size;
509
510 inflateInit(stream);
511 return inflate(stream, 0);
512}
513
5180cacc
LT
514void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
515{
516 int bytes = strlen(buffer) + 1;
d565b341 517 unsigned char *buf = xmalloc(1+size);
5180cacc
LT
518
519 memcpy(buf, buffer + bytes, stream->total_out - bytes);
520 bytes = stream->total_out - bytes;
521 if (bytes < size) {
522 stream->next_out = buf + bytes;
523 stream->avail_out = size - bytes;
524 while (inflate(stream, Z_FINISH) == Z_OK)
525 /* nothing */;
526 }
527 buf[size] = 0;
528 inflateEnd(stream);
529 return buf;
530}
531
532/*
533 * We used to just use "sscanf()", but that's actually way
534 * too permissive for what we want to check. So do an anal
535 * object header parse by hand.
536 */
537int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
538{
539 int i;
540 unsigned long size;
541
542 /*
543 * The type can be at most ten bytes (including the
544 * terminating '\0' that we add), and is followed by
545 * a space.
546 */
547 i = 10;
548 for (;;) {
549 char c = *hdr++;
550 if (c == ' ')
551 break;
552 if (!--i)
553 return -1;
554 *type++ = c;
555 }
556 *type = 0;
557
558 /*
559 * The length must follow immediately, and be in canonical
560 * decimal format (ie "010" is not valid).
561 */
562 size = *hdr++ - '0';
563 if (size > 9)
564 return -1;
565 if (size) {
566 for (;;) {
567 unsigned long c = *hdr - '0';
568 if (c > 9)
569 break;
570 hdr++;
571 size = size * 10 + c;
572 }
573 }
574 *sizep = size;
575
576 /*
577 * The length must be followed by a zero byte
578 */
579 return *hdr ? -1 : 0;
580}
581
0fcfd160
LT
582void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
583{
5180cacc 584 int ret;
0fcfd160 585 z_stream stream;
5180cacc 586 char hdr[8192];
0fcfd160 587
5180cacc
LT
588 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
589 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
590 return NULL;
591
5180cacc 592 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
593}
594
5db47c2b
JH
595static int packed_delta_info(unsigned char *base_sha1,
596 unsigned long delta_size,
597 unsigned long left,
598 char *type,
599 unsigned long *sizep)
600{
3c849742 601 const unsigned char *data;
5db47c2b 602 unsigned char delta_head[64];
3c849742 603 unsigned long result_size, base_size, verify_base_size;
5db47c2b
JH
604 z_stream stream;
605 int st;
606
607 if (left < 20)
608 die("truncated pack file");
609 if (sha1_object_info(base_sha1, type, &base_size))
610 die("cannot get info for delta-pack base");
611
5db47c2b
JH
612 memset(&stream, 0, sizeof(stream));
613
3c849742
JH
614 data = stream.next_in = base_sha1 + 20;
615 stream.avail_in = left - 20;
5db47c2b
JH
616 stream.next_out = delta_head;
617 stream.avail_out = sizeof(delta_head);
618
619 inflateInit(&stream);
620 st = inflate(&stream, Z_FINISH);
621 inflateEnd(&stream);
622 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
623 die("delta data unpack-initial failed");
624
625 /* Examine the initial part of the delta to figure out
626 * the result size. Verify the base size while we are at it.
627 */
628 data = delta_head;
dcde55bc 629 verify_base_size = get_delta_hdr_size(&data);
5db47c2b
JH
630 if (verify_base_size != base_size)
631 die("delta base size mismatch");
632
dcde55bc
NP
633 /* Read the result size */
634 result_size = get_delta_hdr_size(&data);
5db47c2b
JH
635 *sizep = result_size;
636 return 0;
637}
638
a733cb60
LT
639static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
640 enum object_type *type, unsigned long *sizep)
641{
01247d87 642 unsigned shift;
a733cb60
LT
643 unsigned char *pack, c;
644 unsigned long size;
645
646 if (offset >= p->pack_size)
647 die("object offset outside of pack file");
648
649 pack = p->pack_base + offset;
650 c = *pack++;
651 offset++;
652 *type = (c >> 4) & 7;
653 size = c & 15;
01247d87 654 shift = 4;
a733cb60
LT
655 while (c & 0x80) {
656 if (offset >= p->pack_size)
657 die("object offset outside of pack file");
658 c = *pack++;
659 offset++;
01247d87
LT
660 size += (c & 0x7f) << shift;
661 shift += 7;
a733cb60
LT
662 }
663 *sizep = size;
664 return offset;
665}
666
1f688557
JH
667static int packed_object_info(struct pack_entry *entry,
668 char *type, unsigned long *sizep)
669{
670 struct packed_git *p = entry->p;
671 unsigned long offset, size, left;
672 unsigned char *pack;
a733cb60 673 enum object_type kind;
5db47c2b
JH
674
675 if (use_packed_git(p))
676 die("cannot map packed file");
677
a733cb60 678 offset = unpack_object_header(p, entry->offset, &kind, &size);
1f688557 679 pack = p->pack_base + offset;
a733cb60
LT
680 left = p->pack_size - offset;
681
682 switch (kind) {
683 case OBJ_DELTA:
684 return packed_delta_info(pack, size, left, type, sizep);
1f688557 685 break;
a733cb60 686 case OBJ_COMMIT:
1f688557
JH
687 strcpy(type, "commit");
688 break;
a733cb60 689 case OBJ_TREE:
1f688557
JH
690 strcpy(type, "tree");
691 break;
a733cb60 692 case OBJ_BLOB:
1f688557
JH
693 strcpy(type, "blob");
694 break;
a733cb60 695 case OBJ_TAG:
a69d0943
LT
696 strcpy(type, "tag");
697 break;
1f688557
JH
698 default:
699 die("corrupted pack file");
700 }
701 *sizep = size;
702 return 0;
703}
704
705/* forward declaration for a mutually recursive function */
706static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
707
708static void *unpack_delta_entry(unsigned char *base_sha1,
709 unsigned long delta_size,
710 unsigned long left,
711 char *type,
712 unsigned long *sizep)
713{
714 void *data, *delta_data, *result, *base;
715 unsigned long data_size, result_size, base_size;
716 z_stream stream;
717 int st;
718
719 if (left < 20)
720 die("truncated pack file");
721 data = base_sha1 + 20;
722 data_size = left - 20;
723 delta_data = xmalloc(delta_size);
724
725 memset(&stream, 0, sizeof(stream));
726
727 stream.next_in = data;
728 stream.avail_in = data_size;
729 stream.next_out = delta_data;
730 stream.avail_out = delta_size;
731
732 inflateInit(&stream);
733 st = inflate(&stream, Z_FINISH);
734 inflateEnd(&stream);
735 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
736 die("delta data unpack failed");
737
738 /* This may recursively unpack the base, which is what we want */
739 base = read_sha1_file(base_sha1, type, &base_size);
740 if (!base)
741 die("failed to read delta-pack base object %s",
742 sha1_to_hex(base_sha1));
743 result = patch_delta(base, base_size,
744 delta_data, delta_size,
745 &result_size);
746 if (!result)
747 die("failed to apply delta");
748 free(delta_data);
749 free(base);
750 *sizep = result_size;
751 return result;
752}
753
754static void *unpack_non_delta_entry(unsigned char *data,
755 unsigned long size,
756 unsigned long left)
757{
758 int st;
759 z_stream stream;
760 char *buffer;
761
762 buffer = xmalloc(size + 1);
763 buffer[size] = 0;
764 memset(&stream, 0, sizeof(stream));
765 stream.next_in = data;
766 stream.avail_in = left;
767 stream.next_out = buffer;
768 stream.avail_out = size;
769
770 inflateInit(&stream);
771 st = inflate(&stream, Z_FINISH);
772 inflateEnd(&stream);
773 if ((st != Z_STREAM_END) || stream.total_out != size) {
774 free(buffer);
775 return NULL;
776 }
777
778 return buffer;
779}
780
781static void *unpack_entry(struct pack_entry *entry,
782 char *type, unsigned long *sizep)
783{
784 struct packed_git *p = entry->p;
785 unsigned long offset, size, left;
786 unsigned char *pack;
a733cb60 787 enum object_type kind;
1f688557
JH
788
789 if (use_packed_git(p))
790 die("cannot map packed file");
791
a733cb60 792 offset = unpack_object_header(p, entry->offset, &kind, &size);
1f688557 793 pack = p->pack_base + offset;
a733cb60
LT
794 left = p->pack_size - offset;
795 switch (kind) {
796 case OBJ_DELTA:
797 return unpack_delta_entry(pack, size, left, type, sizep);
798 case OBJ_COMMIT:
1f688557
JH
799 strcpy(type, "commit");
800 break;
a733cb60 801 case OBJ_TREE:
1f688557
JH
802 strcpy(type, "tree");
803 break;
a733cb60 804 case OBJ_BLOB:
1f688557
JH
805 strcpy(type, "blob");
806 break;
a733cb60 807 case OBJ_TAG:
a69d0943
LT
808 strcpy(type, "tag");
809 break;
1f688557
JH
810 default:
811 die("corrupted pack file");
812 }
813 *sizep = size;
a733cb60 814 return unpack_non_delta_entry(pack, size, left);
1f688557
JH
815}
816
9a217f2a
JH
817int num_packed_objects(const struct packed_git *p)
818{
819 /* See check_packed_git_idx and pack-objects.c */
820 return (p->index_size - 20 - 20 - 4*256) / 24;
821}
822
823int nth_packed_object_sha1(const struct packed_git *p, int n,
824 unsigned char* sha1)
825{
826 void *index = p->index_base + 256;
827 if (n < 0 || num_packed_objects(p) <= n)
828 return -1;
829 memcpy(sha1, (index + 24 * n + 4), 20);
830 return 0;
831}
832
1f688557
JH
833static int find_pack_entry_1(const unsigned char *sha1,
834 struct pack_entry *e, struct packed_git *p)
835{
836 int *level1_ofs = p->index_base;
837 int hi = ntohl(level1_ofs[*sha1]);
838 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
839 void *index = p->index_base + 256;
840
841 do {
842 int mi = (lo + hi) / 2;
843 int cmp = memcmp(index + 24 * mi + 4, sha1, 20);
844 if (!cmp) {
845 e->offset = ntohl(*((int*)(index + 24 * mi)));
846 memcpy(e->sha1, sha1, 20);
847 e->p = p;
848 return 1;
849 }
850 if (cmp > 0)
851 hi = mi;
852 else
853 lo = mi+1;
854 } while (lo < hi);
855 return 0;
856}
857
858static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
859{
860 struct packed_git *p;
861 prepare_packed_git();
862
863 for (p = packed_git; p; p = p->next) {
864 if (find_pack_entry_1(sha1, e, p))
865 return 1;
866 }
867 return 0;
868}
869
36e4d74a 870int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 871{
36e4d74a 872 int status;
65c2e0c3
JH
873 unsigned long mapsize, size;
874 void *map;
875 z_stream stream;
36e4d74a 876 char hdr[128];
65c2e0c3 877
1f688557
JH
878 map = map_sha1_file_internal(sha1, &mapsize, 0);
879 if (!map) {
880 struct pack_entry e;
881
882 if (!find_pack_entry(sha1, &e))
883 return error("unable to find %s", sha1_to_hex(sha1));
884 if (!packed_object_info(&e, type, sizep))
885 return 0;
886 /* sheesh */
887 map = unpack_entry(&e, type, sizep);
888 free(map);
889 return (map == NULL) ? 0 : -1;
890 }
36e4d74a
JH
891 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
892 status = error("unable to unpack %s header",
893 sha1_to_hex(sha1));
894 if (parse_sha1_header(hdr, type, &size) < 0)
895 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 896 else {
65c2e0c3 897 status = 0;
c4584ae3 898 *sizep = size;
65c2e0c3 899 }
65c2e0c3
JH
900 inflateEnd(&stream);
901 munmap(map, mapsize);
902 return status;
903}
904
1f688557
JH
905static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
906{
907 struct pack_entry e;
908
909 if (!find_pack_entry(sha1, &e)) {
910 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
911 return NULL;
912 }
913 return unpack_entry(&e, type, size);
914}
915
0fcfd160
LT
916void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
917{
918 unsigned long mapsize;
919 void *map, *buf;
920
1f688557 921 map = map_sha1_file_internal(sha1, &mapsize, 0);
0fcfd160
LT
922 if (map) {
923 buf = unpack_sha1_file(map, mapsize, type, size);
924 munmap(map, mapsize);
925 return buf;
926 }
1f688557 927 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
928}
929
40469ee9 930void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 931 const char *required_type,
40469ee9
JH
932 unsigned long *size,
933 unsigned char *actual_sha1_return)
f4913f91
JH
934{
935 char type[20];
936 void *buffer;
937 unsigned long isize;
40469ee9 938 unsigned char actual_sha1[20];
f4913f91 939
40469ee9
JH
940 memcpy(actual_sha1, sha1, 20);
941 while (1) {
942 int ref_length = -1;
943 const char *ref_type = NULL;
f4913f91 944
40469ee9
JH
945 buffer = read_sha1_file(actual_sha1, type, &isize);
946 if (!buffer)
947 return NULL;
948 if (!strcmp(type, required_type)) {
949 *size = isize;
950 if (actual_sha1_return)
951 memcpy(actual_sha1_return, actual_sha1, 20);
952 return buffer;
953 }
954 /* Handle references */
955 else if (!strcmp(type, "commit"))
956 ref_type = "tree ";
957 else if (!strcmp(type, "tag"))
958 ref_type = "object ";
959 else {
960 free(buffer);
961 return NULL;
962 }
963 ref_length = strlen(ref_type);
f4913f91 964
40469ee9
JH
965 if (memcmp(buffer, ref_type, ref_length) ||
966 get_sha1_hex(buffer + ref_length, actual_sha1)) {
967 free(buffer);
968 return NULL;
969 }
970 /* Now we have the ID of the referred-to object in
971 * actual_sha1. Check again. */
f4913f91 972 }
f4913f91
JH
973}
974
d410c0f5
JH
975static char *write_sha1_file_prepare(void *buf,
976 unsigned long len,
977 const char *type,
978 unsigned char *sha1,
979 unsigned char *hdr,
980 int *hdrlen)
981{
982 SHA_CTX c;
983
984 /* Generate the header */
985 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
986
987 /* Sha1.. */
988 SHA1_Init(&c);
989 SHA1_Update(&c, hdr, *hdrlen);
990 SHA1_Update(&c, buf, len);
991 SHA1_Final(sha1, &c);
992
993 return sha1_file_name(sha1);
994}
995
bf0f910d 996int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
997{
998 int size;
bf0f910d 999 unsigned char *compressed;
0fcfd160
LT
1000 z_stream stream;
1001 unsigned char sha1[20];
706bc531 1002 char *filename;
aac17941 1003 static char tmpfile[PATH_MAX];
bf0f910d 1004 unsigned char hdr[50];
aac17941 1005 int fd, hdrlen, ret;
a44c9a5e 1006
d410c0f5
JH
1007 /* Normally if we have it in the pack then we do not bother writing
1008 * it out into .git/objects/??/?{38} file.
1009 */
1010 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
706bc531
LT
1011 if (returnsha1)
1012 memcpy(returnsha1, sha1, 20);
d410c0f5
JH
1013 if (has_sha1_file(sha1))
1014 return 0;
aac17941
LT
1015 fd = open(filename, O_RDONLY);
1016 if (fd >= 0) {
706bc531 1017 /*
aac17941
LT
1018 * FIXME!!! We might do collision checking here, but we'd
1019 * need to uncompress the old file and check it. Later.
706bc531 1020 */
aac17941 1021 close(fd);
706bc531
LT
1022 return 0;
1023 }
1024
aac17941
LT
1025 if (errno != ENOENT) {
1026 fprintf(stderr, "sha1 file %s: %s", filename, strerror(errno));
1027 return -1;
1028 }
1029
1030 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1031
aac17941
LT
1032 fd = mkstemp(tmpfile);
1033 if (fd < 0) {
1034 fprintf(stderr, "unable to create temporary sha1 filename %s: %s", tmpfile, strerror(errno));
1035 return -1;
1036 }
1037
0fcfd160
LT
1038 /* Set it up */
1039 memset(&stream, 0, sizeof(stream));
1040 deflateInit(&stream, Z_BEST_COMPRESSION);
a44c9a5e 1041 size = deflateBound(&stream, len+hdrlen);
812666c8 1042 compressed = xmalloc(size);
0fcfd160
LT
1043
1044 /* Compress it */
0fcfd160
LT
1045 stream.next_out = compressed;
1046 stream.avail_out = size;
a44c9a5e
LT
1047
1048 /* First header.. */
1049 stream.next_in = hdr;
1050 stream.avail_in = hdrlen;
1051 while (deflate(&stream, 0) == Z_OK)
6ffcee88 1052 /* nothing */;
a44c9a5e
LT
1053
1054 /* Then the data itself.. */
1055 stream.next_in = buf;
1056 stream.avail_in = len;
0fcfd160
LT
1057 while (deflate(&stream, Z_FINISH) == Z_OK)
1058 /* nothing */;
1059 deflateEnd(&stream);
1060 size = stream.total_out;
1061
706bc531
LT
1062 if (write(fd, compressed, size) != size)
1063 die("unable to write file");
aac17941 1064 fchmod(fd, 0444);
706bc531 1065 close(fd);
383f85b7 1066 free(compressed);
0fcfd160 1067
aac17941 1068 ret = link(tmpfile, filename);
a31c6d02 1069 if (ret < 0) {
aac17941 1070 ret = errno;
a31c6d02
LT
1071
1072 /*
1073 * Coda hack - coda doesn't like cross-directory links,
1074 * so we fall back to a rename, which will mean that it
1075 * won't be able to check collisions, but that's not a
1076 * big deal.
1077 *
1078 * When this succeeds, we just return 0. We have nothing
1079 * left to unlink.
1080 */
1081 if (ret == EXDEV && !rename(tmpfile, filename))
1082 return 0;
1083 }
aac17941
LT
1084 unlink(tmpfile);
1085 if (ret) {
1086 if (ret != EEXIST) {
1087 fprintf(stderr, "unable to write sha1 filename %s: %s", filename, strerror(ret));
0fcfd160 1088 return -1;
aac17941
LT
1089 }
1090 /* FIXME!!! Collision check here ? */
0fcfd160 1091 }
aac17941 1092
0fcfd160
LT
1093 return 0;
1094}
8237b185
DB
1095
1096int write_sha1_from_fd(const unsigned char *sha1, int fd)
1097{
1098 char *filename = sha1_file_name(sha1);
1099
1100 int local;
1101 z_stream stream;
1102 unsigned char real_sha1[20];
bf0f910d
BG
1103 unsigned char buf[4096];
1104 unsigned char discard[4096];
8237b185
DB
1105 int ret;
1106 SHA_CTX c;
1107
1108 local = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0666);
1109
1110 if (local < 0)
1111 return error("Couldn't open %s\n", filename);
1112
1113 memset(&stream, 0, sizeof(stream));
1114
1115 inflateInit(&stream);
1116
1117 SHA1_Init(&c);
1118
1119 do {
1120 ssize_t size;
1121 size = read(fd, buf, 4096);
1122 if (size <= 0) {
1123 close(local);
1124 unlink(filename);
1125 if (!size)
1126 return error("Connection closed?");
1127 perror("Reading from connection");
1128 return -1;
1129 }
1130 write(local, buf, size);
1131 stream.avail_in = size;
1132 stream.next_in = buf;
1133 do {
1134 stream.next_out = discard;
1135 stream.avail_out = sizeof(discard);
1136 ret = inflate(&stream, Z_SYNC_FLUSH);
1137 SHA1_Update(&c, discard, sizeof(discard) -
1138 stream.avail_out);
1139 } while (stream.avail_in && ret == Z_OK);
1140
1141 } while (ret == Z_OK);
1142 inflateEnd(&stream);
1143
1144 close(local);
1145 SHA1_Final(real_sha1, &c);
1146 if (ret != Z_STREAM_END) {
1147 unlink(filename);
1148 return error("File %s corrupted", sha1_to_hex(sha1));
1149 }
1150 if (memcmp(sha1, real_sha1, 20)) {
1151 unlink(filename);
1152 return error("File %s has bad hash\n", sha1_to_hex(sha1));
1153 }
1154
1155 return 0;
1156}
1157
1158int has_sha1_file(const unsigned char *sha1)
1159{
8237b185 1160 struct stat st;
1f688557
JH
1161 struct pack_entry e;
1162
1163 if (find_sha1_file(sha1, &st))
1164 return 1;
1165 return find_pack_entry(sha1, &e);
8237b185 1166}
74400e71
JH
1167
1168int index_fd(unsigned char *sha1, int fd, struct stat *st)
1169{
74400e71 1170 unsigned long size = st->st_size;
aac17941
LT
1171 void *buf;
1172 int ret;
74400e71 1173
aac17941 1174 buf = "";
74400e71 1175 if (size)
aac17941 1176 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1177 close(fd);
aac17941 1178 if ((int)(long)buf == -1)
74400e71
JH
1179 return -1;
1180
aac17941
LT
1181 ret = write_sha1_file(buf, size, "blob", sha1);
1182 if (size)
1183 munmap(buf, size);
1184 return ret;
74400e71 1185}