Documentation: Fix howto/revert-branch-rebase.html generation
[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 */
0fcfd160 9#include "cache.h"
1f688557 10#include "delta.h"
a733cb60 11#include "pack.h"
8e440259
PE
12#include "blob.h"
13#include "commit.h"
14#include "tag.h"
15#include "tree.h"
0fcfd160 16
144bde78
LT
17#ifndef O_NOATIME
18#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
19#define O_NOATIME 01000000
20#else
21#define O_NOATIME 0
22#endif
23#endif
24
96f1e58f 25const unsigned char null_sha1[20];
88cd621d 26
144bde78
LT
27static unsigned int sha1_file_open_flag = O_NOATIME;
28
0fcfd160
LT
29static unsigned hexval(char c)
30{
31 if (c >= '0' && c <= '9')
32 return c - '0';
33 if (c >= 'a' && c <= 'f')
34 return c - 'a' + 10;
35 if (c >= 'A' && c <= 'F')
36 return c - 'A' + 10;
37 return ~0;
38}
39
40int get_sha1_hex(const char *hex, unsigned char *sha1)
41{
42 int i;
43 for (i = 0; i < 20; i++) {
44 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
45 if (val & ~0xff)
46 return -1;
47 *sha1++ = val;
48 hex += 2;
49 }
50 return 0;
51}
52
b2cb9425
JH
53int safe_create_leading_directories(char *path)
54{
55 char *pos = path;
67d42212
JR
56 struct stat st;
57
67ffdf4c
JS
58 if (*pos == '/')
59 pos++;
b2cb9425
JH
60
61 while (pos) {
62 pos = strchr(pos, '/');
63 if (!pos)
64 break;
65 *pos = 0;
67d42212
JR
66 if (!stat(path, &st)) {
67 /* path exists */
68 if (!S_ISDIR(st.st_mode)) {
b2cb9425 69 *pos = '/';
67d42212 70 return -3;
b2cb9425 71 }
457f06d6 72 }
67d42212
JR
73 else if (mkdir(path, 0777)) {
74 *pos = '/';
75 return -1;
76 }
457f06d6
JS
77 else if (adjust_shared_perm(path)) {
78 *pos = '/';
79 return -2;
80 }
b2cb9425
JH
81 *pos++ = '/';
82 }
83 return 0;
84}
723c31fe 85
0fcfd160
LT
86char * sha1_to_hex(const unsigned char *sha1)
87{
dcb3450f
LT
88 static int bufno;
89 static char hexbuffer[4][50];
0fcfd160 90 static const char hex[] = "0123456789abcdef";
dcb3450f 91 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
92 int i;
93
94 for (i = 0; i < 20; i++) {
95 unsigned int val = *sha1++;
96 *buf++ = hex[val >> 4];
97 *buf++ = hex[val & 0xf];
98 }
1e80e044
JS
99 *buf = '\0';
100
0fcfd160
LT
101 return buffer;
102}
103
ace1534d
JH
104static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
105{
106 int i;
107 for (i = 0; i < 20; i++) {
108 static char hex[] = "0123456789abcdef";
109 unsigned int val = sha1[i];
110 char *pos = pathbuf + i*2 + (i > 0);
111 *pos++ = hex[val >> 4];
112 *pos = hex[val & 0xf];
113 }
114}
115
0fcfd160
LT
116/*
117 * NOTE! This returns a statically allocated buffer, so you have to be
118 * careful about using it. Do a "strdup()" if you need to save the
119 * filename.
ace1534d
JH
120 *
121 * Also note that this returns the location for creating. Reading
122 * SHA1 file can happen from any alternate directory listed in the
d19938ab 123 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 124 * the primary object database.
0fcfd160
LT
125 */
126char *sha1_file_name(const unsigned char *sha1)
127{
0fcfd160
LT
128 static char *name, *base;
129
130 if (!base) {
d19938ab 131 const char *sha1_file_directory = get_object_directory();
0fcfd160 132 int len = strlen(sha1_file_directory);
812666c8 133 base = xmalloc(len + 60);
0fcfd160
LT
134 memcpy(base, sha1_file_directory, len);
135 memset(base+len, 0, 60);
136 base[len] = '/';
137 base[len+3] = '/';
138 name = base + len + 1;
139 }
ace1534d 140 fill_sha1_path(name, sha1);
0fcfd160
LT
141 return base;
142}
143
bf592c50
DB
144char *sha1_pack_name(const unsigned char *sha1)
145{
146 static const char hex[] = "0123456789abcdef";
147 static char *name, *base, *buf;
148 int i;
149
150 if (!base) {
151 const char *sha1_file_directory = get_object_directory();
152 int len = strlen(sha1_file_directory);
153 base = xmalloc(len + 60);
154 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
155 name = base + len + 11;
156 }
157
158 buf = name;
159
160 for (i = 0; i < 20; i++) {
161 unsigned int val = *sha1++;
162 *buf++ = hex[val >> 4];
163 *buf++ = hex[val & 0xf];
164 }
165
166 return base;
167}
168
169char *sha1_pack_index_name(const unsigned char *sha1)
170{
171 static const char hex[] = "0123456789abcdef";
172 static char *name, *base, *buf;
173 int i;
174
175 if (!base) {
176 const char *sha1_file_directory = get_object_directory();
177 int len = strlen(sha1_file_directory);
178 base = xmalloc(len + 60);
179 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
180 name = base + len + 11;
181 }
182
183 buf = name;
184
185 for (i = 0; i < 20; i++) {
186 unsigned int val = *sha1++;
187 *buf++ = hex[val >> 4];
188 *buf++ = hex[val & 0xf];
189 }
190
191 return base;
192}
193
d5a63b99
JH
194struct alternate_object_database *alt_odb_list;
195static struct alternate_object_database **alt_odb_tail;
ace1534d 196
c2f493a4
MW
197static void read_info_alternates(const char * alternates, int depth);
198
ddd5d056
JH
199/*
200 * Prepare alternate object database registry.
d5a63b99
JH
201 *
202 * The variable alt_odb_list points at the list of struct
203 * alternate_object_database. The elements on this list come from
204 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
205 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
206 * whose contents is similar to that environment variable but can be
207 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
208 * contains "/the/directory/corresponding/to/.git/objects/...", while
209 * its name points just after the slash at the end of ".git/objects/"
210 * in the example above, and has enough space to hold 40-byte hex
211 * SHA1, an extra slash for the first level indirection, and the
212 * terminating NUL.
ddd5d056 213 */
c2f493a4 214static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 215{
c2f493a4 216 struct stat st;
1494e038 217 const char *objdir = get_object_directory();
c2f493a4
MW
218 struct alternate_object_database *ent;
219 struct alternate_object_database *alt;
220 /* 43 = 40-byte + 2 '/' + terminating NUL */
221 int pfxlen = len;
222 int entlen = pfxlen + 43;
ccfd3e99 223 int base_len = -1;
d5a63b99 224
c2f493a4
MW
225 if (*entry != '/' && relative_base) {
226 /* Relative alt-odb */
227 if (base_len < 0)
228 base_len = strlen(relative_base) + 1;
229 entlen += base_len;
230 pfxlen += base_len;
231 }
232 ent = xmalloc(sizeof(*ent) + entlen);
233
234 if (*entry != '/' && relative_base) {
235 memcpy(ent->base, relative_base, base_len - 1);
236 ent->base[base_len - 1] = '/';
237 memcpy(ent->base + base_len, entry, len);
238 }
239 else
240 memcpy(ent->base, entry, pfxlen);
241
242 ent->name = ent->base + pfxlen + 1;
243 ent->base[pfxlen + 3] = '/';
244 ent->base[pfxlen] = ent->base[entlen-1] = 0;
245
246 /* Detect cases where alternate disappeared */
247 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
248 error("object directory %s does not exist; "
249 "check .git/objects/info/alternates.",
250 ent->base);
251 free(ent);
252 return -1;
253 }
254
255 /* Prevent the common mistake of listing the same
256 * thing twice, or object directory itself.
257 */
258 for (alt = alt_odb_list; alt; alt = alt->next) {
259 if (!memcmp(ent->base, alt->base, pfxlen)) {
260 free(ent);
261 return -1;
262 }
263 }
264 if (!memcmp(ent->base, objdir, pfxlen)) {
265 free(ent);
266 return -1;
267 }
268
269 /* add the alternate entry */
270 *alt_odb_tail = ent;
271 alt_odb_tail = &(ent->next);
272 ent->next = NULL;
273
274 /* recursively add alternates */
275 read_info_alternates(ent->base, depth + 1);
276
277 ent->base[pfxlen] = '/';
278
279 return 0;
280}
281
282static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
283 const char *relative_base, int depth)
284{
285 const char *cp, *last;
286
287 if (depth > 5) {
288 error("%s: ignoring alternate object stores, nesting too deep.",
289 relative_base);
290 return;
291 }
292
d5a63b99 293 last = alt;
9577e7e3
JH
294 while (last < ep) {
295 cp = last;
296 if (cp < ep && *cp == '#') {
297 while (cp < ep && *cp != sep)
298 cp++;
299 last = cp + 1;
300 continue;
301 }
c2f493a4
MW
302 while (cp < ep && *cp != sep)
303 cp++;
d5a63b99 304 if (last != cp) {
c2f493a4
MW
305 if ((*last != '/') && depth) {
306 error("%s: ignoring relative alternate object store %s",
307 relative_base, last);
308 } else {
309 link_alt_odb_entry(last, cp - last,
310 relative_base, depth);
1494e038 311 }
d5a63b99 312 }
9577e7e3 313 while (cp < ep && *cp == sep)
d5a63b99
JH
314 cp++;
315 last = cp;
9577e7e3 316 }
d5a63b99
JH
317}
318
c2f493a4 319static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 320{
9577e7e3 321 char *map;
d5a63b99 322 struct stat st;
c2f493a4
MW
323 char path[PATH_MAX];
324 int fd;
d5a63b99 325
c2f493a4 326 sprintf(path, "%s/info/alternates", relative_base);
d5a63b99
JH
327 fd = open(path, O_RDONLY);
328 if (fd < 0)
329 return;
330 if (fstat(fd, &st) || (st.st_size == 0)) {
331 close(fd);
9a217f2a 332 return;
ace1534d 333 }
d5a63b99
JH
334 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
335 close(fd);
336 if (map == MAP_FAILED)
337 return;
338
c2f493a4
MW
339 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
340
d5a63b99 341 munmap(map, st.st_size);
ace1534d
JH
342}
343
c2f493a4
MW
344void prepare_alt_odb(void)
345{
554fe20d 346 const char *alt;
c2f493a4
MW
347
348 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
349 if (!alt) alt = "";
350
351 if (alt_odb_tail)
352 return;
353 alt_odb_tail = &alt_odb_list;
354 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
355
356 read_info_alternates(get_object_directory(), 0);
357}
358
ace1534d
JH
359static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
360{
ace1534d 361 char *name = sha1_file_name(sha1);
d5a63b99 362 struct alternate_object_database *alt;
ace1534d
JH
363
364 if (!stat(name, st))
365 return name;
9a217f2a 366 prepare_alt_odb();
d5a63b99
JH
367 for (alt = alt_odb_list; alt; alt = alt->next) {
368 name = alt->name;
ace1534d 369 fill_sha1_path(name, sha1);
d5a63b99
JH
370 if (!stat(alt->base, st))
371 return alt->base;
ace1534d
JH
372 }
373 return NULL;
374}
375
1f688557
JH
376#define PACK_MAX_SZ (1<<26)
377static int pack_used_ctr;
378static unsigned long pack_mapped;
9a217f2a 379struct packed_git *packed_git;
1f688557 380
1f688557
JH
381static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
382 void **idx_map_)
383{
384 void *idx_map;
385 unsigned int *index;
386 unsigned long idx_size;
387 int nr, i;
e93ec6f9 388 int fd = open(path, O_RDONLY);
1f688557
JH
389 struct stat st;
390 if (fd < 0)
391 return -1;
392 if (fstat(fd, &st)) {
393 close(fd);
394 return -1;
395 }
396 idx_size = st.st_size;
397 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
398 close(fd);
399 if (idx_map == MAP_FAILED)
400 return -1;
401
402 index = idx_map;
4d235c80
LT
403 *idx_map_ = idx_map;
404 *idx_size_ = idx_size;
1f688557
JH
405
406 /* check index map */
f9253394 407 if (idx_size < 4*256 + 20 + 20)
1f688557
JH
408 return error("index file too small");
409 nr = 0;
410 for (i = 0; i < 256; i++) {
411 unsigned int n = ntohl(index[i]);
412 if (n < nr)
413 return error("non-monotonic index");
414 nr = n;
415 }
416
417 /*
418 * Total size:
419 * - 256 index entries 4 bytes each
420 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
421 * - 20-byte SHA1 of the packfile
422 * - 20-byte SHA1 file checksum
423 */
424 if (idx_size != 4*256 + nr * 24 + 20 + 20)
425 return error("wrong index file size");
426
1f688557
JH
427 return 0;
428}
429
f9253394 430static int unuse_one_packed_git(void)
1f688557 431{
f9253394
JH
432 struct packed_git *p, *lru = NULL;
433
434 for (p = packed_git; p; p = p->next) {
435 if (p->pack_use_cnt || !p->pack_base)
436 continue;
437 if (!lru || p->pack_last_used < lru->pack_last_used)
438 lru = p;
439 }
440 if (!lru)
441 return 0;
442 munmap(lru->pack_base, lru->pack_size);
443 lru->pack_base = NULL;
444 return 1;
445}
446
447void unuse_packed_git(struct packed_git *p)
448{
449 p->pack_use_cnt--;
1f688557
JH
450}
451
f9253394 452int use_packed_git(struct packed_git *p)
1f688557 453{
bf592c50
DB
454 if (!p->pack_size) {
455 struct stat st;
a9486b02 456 /* We created the struct before we had the pack */
bf592c50
DB
457 stat(p->pack_name, &st);
458 if (!S_ISREG(st.st_mode))
459 die("packfile %s not a regular file", p->pack_name);
460 p->pack_size = st.st_size;
461 }
1f688557
JH
462 if (!p->pack_base) {
463 int fd;
464 struct stat st;
465 void *map;
da756011 466 struct pack_header *hdr;
1f688557
JH
467
468 pack_mapped += p->pack_size;
f9253394
JH
469 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
470 ; /* nothing */
1f688557
JH
471 fd = open(p->pack_name, O_RDONLY);
472 if (fd < 0)
f9253394 473 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
474 if (fstat(fd, &st)) {
475 close(fd);
f9253394 476 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
477 }
478 if (st.st_size != p->pack_size)
f9253394 479 die("packfile %s size mismatch.", p->pack_name);
1f688557
JH
480 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
481 close(fd);
482 if (map == MAP_FAILED)
f9253394 483 die("packfile %s cannot be mapped.", p->pack_name);
1f688557 484 p->pack_base = map;
f9253394 485
da756011
SP
486 /* Check if we understand this pack file. If we don't we're
487 * likely too old to handle it.
488 */
489 hdr = map;
490 if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
491 die("packfile %s isn't actually a pack.", p->pack_name);
492 if (!pack_version_ok(hdr->hdr_version))
493 die("packfile %s is version %i and not supported"
494 " (try upgrading GIT to a newer version)",
495 p->pack_name, ntohl(hdr->hdr_version));
496
f9253394
JH
497 /* Check if the pack file matches with the index file.
498 * this is cheap.
499 */
a89fccd2
DR
500 if (hashcmp((unsigned char *)(p->index_base) +
501 p->index_size - 40,
502 (unsigned char *)p->pack_base +
503 p->pack_size - 20)) {
f9253394 504 die("packfile %s does not match index.", p->pack_name);
bf592c50 505 }
1f688557
JH
506 }
507 p->pack_last_used = pack_used_ctr++;
f9253394 508 p->pack_use_cnt++;
1f688557
JH
509 return 0;
510}
511
9d835df2 512struct packed_git *add_packed_git(char *path, int path_len, int local)
1f688557
JH
513{
514 struct stat st;
515 struct packed_git *p;
516 unsigned long idx_size;
517 void *idx_map;
c0bbbb1b 518 unsigned char sha1[20];
1f688557
JH
519
520 if (check_packed_git_idx(path, &idx_size, &idx_map))
521 return NULL;
522
523 /* do we have a corresponding .pack file? */
524 strcpy(path + path_len - 4, ".pack");
525 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
526 munmap(idx_map, idx_size);
527 return NULL;
528 }
529 /* ok, it looks sane as far as we can check without
530 * actually mapping the pack file.
531 */
532 p = xmalloc(sizeof(*p) + path_len + 2);
533 strcpy(p->pack_name, path);
534 p->index_size = idx_size;
535 p->pack_size = st.st_size;
536 p->index_base = idx_map;
537 p->next = NULL;
d85a4fee 538 p->pack_base = NULL;
1f688557 539 p->pack_last_used = 0;
f9253394 540 p->pack_use_cnt = 0;
9d835df2 541 p->pack_local = local;
f4a11066 542 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
e702496e 543 hashcpy(p->sha1, sha1);
1f688557
JH
544 return p;
545}
546
bf592c50 547struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
548{
549 char *path = sha1_pack_index_name(sha1);
550 return parse_pack_index_file(sha1, path);
551}
552
2ab141a2 553struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
bf592c50
DB
554{
555 struct packed_git *p;
556 unsigned long idx_size;
557 void *idx_map;
c508df5e 558 char *path;
bf592c50 559
c508df5e 560 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
bf592c50
DB
561 return NULL;
562
563 path = sha1_pack_name(sha1);
564
565 p = xmalloc(sizeof(*p) + strlen(path) + 2);
566 strcpy(p->pack_name, path);
567 p->index_size = idx_size;
568 p->pack_size = 0;
569 p->index_base = idx_map;
570 p->next = NULL;
571 p->pack_base = NULL;
572 p->pack_last_used = 0;
573 p->pack_use_cnt = 0;
e702496e 574 hashcpy(p->sha1, sha1);
bf592c50
DB
575 return p;
576}
577
578void install_packed_git(struct packed_git *pack)
579{
580 pack->next = packed_git;
581 packed_git = pack;
582}
583
9d835df2 584static void prepare_packed_git_one(char *objdir, int local)
1f688557
JH
585{
586 char path[PATH_MAX];
587 int len;
588 DIR *dir;
589 struct dirent *de;
590
591 sprintf(path, "%s/pack", objdir);
592 len = strlen(path);
593 dir = opendir(path);
b5b16990 594 if (!dir) {
26125f6b 595 if (errno != ENOENT)
bd2afde8 596 error("unable to open object pack directory: %s: %s",
26125f6b 597 path, strerror(errno));
1f688557 598 return;
b5b16990 599 }
1f688557
JH
600 path[len++] = '/';
601 while ((de = readdir(dir)) != NULL) {
602 int namelen = strlen(de->d_name);
603 struct packed_git *p;
604
5bb1cda5 605 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
606 continue;
607
608 /* we have .idx. Is it a file we can map? */
609 strcpy(path + len, de->d_name);
86f7780c
JK
610 for (p = packed_git; p; p = p->next) {
611 if (!memcmp(path, p->pack_name, len + namelen - 4))
612 break;
613 }
614 if (p)
615 continue;
9d835df2 616 p = add_packed_git(path, len + namelen, local);
1f688557
JH
617 if (!p)
618 continue;
619 p->next = packed_git;
620 packed_git = p;
621 }
5b35bcd5 622 closedir(dir);
1f688557
JH
623}
624
637cdd9d 625static int prepare_packed_git_run_once = 0;
9a217f2a 626void prepare_packed_git(void)
1f688557 627{
d5a63b99 628 struct alternate_object_database *alt;
1f688557 629
637cdd9d 630 if (prepare_packed_git_run_once)
1f688557 631 return;
9d835df2 632 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 633 prepare_alt_odb();
d5a63b99 634 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 635 alt->name[-1] = 0;
9d835df2 636 prepare_packed_git_one(alt->base, 0);
1494e038 637 alt->name[-1] = '/';
1f688557 638 }
637cdd9d
JK
639 prepare_packed_git_run_once = 1;
640}
641
642static void reprepare_packed_git(void)
643{
644 prepare_packed_git_run_once = 0;
645 prepare_packed_git();
1f688557
JH
646}
647
5d6ccf5c 648int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160 649{
d98b46f8 650 char header[100];
0fcfd160
LT
651 unsigned char real_sha1[20];
652 SHA_CTX c;
653
654 SHA1_Init(&c);
d98b46f8 655 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
0fcfd160
LT
656 SHA1_Update(&c, map, size);
657 SHA1_Final(real_sha1, &c);
a89fccd2 658 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
659}
660
bb6b8e4f 661void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 662{
0fcfd160
LT
663 struct stat st;
664 void *map;
144bde78 665 int fd;
ace1534d
JH
666 char *filename = find_sha1_file(sha1, &st);
667
668 if (!filename) {
ace1534d
JH
669 return NULL;
670 }
0fcfd160 671
144bde78 672 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 673 if (fd < 0) {
144bde78
LT
674 /* See if it works without O_NOATIME */
675 switch (sha1_file_open_flag) {
676 default:
677 fd = open(filename, O_RDONLY);
678 if (fd >= 0)
679 break;
680 /* Fallthrough */
681 case 0:
144bde78
LT
682 return NULL;
683 }
684
1f688557
JH
685 /* If it failed once, it will probably fail again.
686 * Stop using O_NOATIME
687 */
144bde78 688 sha1_file_open_flag = 0;
0fcfd160 689 }
0fcfd160
LT
690 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
691 close(fd);
e35f9824 692 if (map == MAP_FAILED)
0fcfd160
LT
693 return NULL;
694 *size = st.st_size;
695 return map;
696}
697
bb6b8e4f
JH
698int legacy_loose_object(unsigned char *map)
699{
700 unsigned int word;
701
702 /*
703 * Is it a zlib-compressed buffer? If so, the first byte
704 * must be 0x78 (15-bit window size, deflated), and the
705 * first 16-bit word is evenly divisible by 31
706 */
707 word = (map[0] << 8) + map[1];
708 if (map[0] == 0x78 && !(word % 31))
709 return 1;
710 else
711 return 0;
712}
713
93821bd9 714static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
c4483576 715{
93821bd9 716 unsigned char c;
bb6b8e4f 717 unsigned int bits;
93821bd9
LT
718 unsigned long size;
719 static const char *typename[8] = {
720 NULL, /* OBJ_EXT */
721 "commit", "tree", "blob", "tag",
722 NULL, NULL, NULL
723 };
724 const char *type;
725
c4483576
LT
726 /* Get the data stream */
727 memset(stream, 0, sizeof(*stream));
728 stream->next_in = map;
729 stream->avail_in = mapsize;
730 stream->next_out = buffer;
93821bd9
LT
731 stream->avail_out = bufsiz;
732
bb6b8e4f 733 if (legacy_loose_object(map)) {
93821bd9
LT
734 inflateInit(stream);
735 return inflate(stream, 0);
736 }
737
738 c = *map++;
739 mapsize--;
740 type = typename[(c >> 4) & 7];
741 if (!type)
742 return -1;
c4483576 743
93821bd9
LT
744 bits = 4;
745 size = c & 0xf;
746 while ((c & 0x80)) {
747 if (bits >= 8*sizeof(long))
748 return -1;
749 c = *map++;
750 size += (c & 0x7f) << bits;
751 bits += 7;
752 mapsize--;
753 }
754
755 /* Set up the stream for the rest.. */
756 stream->next_in = map;
757 stream->avail_in = mapsize;
c4483576 758 inflateInit(stream);
93821bd9
LT
759
760 /* And generate the fake traditional header */
761 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", type, size);
762 return 0;
c4483576
LT
763}
764
6da4016a 765static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
5180cacc
LT
766{
767 int bytes = strlen(buffer) + 1;
d565b341 768 unsigned char *buf = xmalloc(1+size);
93821bd9 769 unsigned long n;
5180cacc 770
93821bd9
LT
771 n = stream->total_out - bytes;
772 if (n > size)
773 n = size;
774 memcpy(buf, (char *) buffer + bytes, n);
775 bytes = n;
5180cacc
LT
776 if (bytes < size) {
777 stream->next_out = buf + bytes;
778 stream->avail_out = size - bytes;
779 while (inflate(stream, Z_FINISH) == Z_OK)
780 /* nothing */;
781 }
782 buf[size] = 0;
783 inflateEnd(stream);
784 return buf;
785}
786
787/*
788 * We used to just use "sscanf()", but that's actually way
789 * too permissive for what we want to check. So do an anal
790 * object header parse by hand.
791 */
38d3874d 792static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
5180cacc
LT
793{
794 int i;
795 unsigned long size;
796
797 /*
798 * The type can be at most ten bytes (including the
799 * terminating '\0' that we add), and is followed by
800 * a space.
801 */
802 i = 10;
803 for (;;) {
804 char c = *hdr++;
805 if (c == ' ')
806 break;
807 if (!--i)
808 return -1;
809 *type++ = c;
810 }
811 *type = 0;
812
813 /*
814 * The length must follow immediately, and be in canonical
815 * decimal format (ie "010" is not valid).
816 */
817 size = *hdr++ - '0';
818 if (size > 9)
819 return -1;
820 if (size) {
821 for (;;) {
822 unsigned long c = *hdr - '0';
823 if (c > 9)
824 break;
825 hdr++;
826 size = size * 10 + c;
827 }
828 }
829 *sizep = size;
830
831 /*
832 * The length must be followed by a zero byte
833 */
834 return *hdr ? -1 : 0;
835}
836
0fcfd160
LT
837void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
838{
5180cacc 839 int ret;
0fcfd160 840 z_stream stream;
5180cacc 841 char hdr[8192];
0fcfd160 842
5180cacc
LT
843 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
844 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
845 return NULL;
846
5180cacc 847 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
848}
849
f3bf9224
JH
850/* forward declaration for a mutually recursive function */
851static int packed_object_info(struct pack_entry *entry,
852 char *type, unsigned long *sizep);
853
5db47c2b
JH
854static int packed_delta_info(unsigned char *base_sha1,
855 unsigned long delta_size,
856 unsigned long left,
857 char *type,
f3bf9224
JH
858 unsigned long *sizep,
859 struct packed_git *p)
5db47c2b 860{
f3bf9224
JH
861 struct pack_entry base_ent;
862
5db47c2b
JH
863 if (left < 20)
864 die("truncated pack file");
5db47c2b 865
f3bf9224
JH
866 /* The base entry _must_ be in the same pack */
867 if (!find_pack_entry_one(base_sha1, &base_ent, p))
868 die("failed to find delta-pack base object %s",
869 sha1_to_hex(base_sha1));
870
c62266f3
JH
871 /* We choose to only get the type of the base object and
872 * ignore potentially corrupt pack file that expects the delta
873 * based on a base with a wrong size. This saves tons of
874 * inflate() calls.
875 */
5db47c2b 876
f3bf9224 877 if (packed_object_info(&base_ent, type, NULL))
c62266f3 878 die("cannot get info for delta-pack base");
5db47c2b 879
c62266f3
JH
880 if (sizep) {
881 const unsigned char *data;
882 unsigned char delta_head[64];
883 unsigned long result_size;
884 z_stream stream;
885 int st;
886
887 memset(&stream, 0, sizeof(stream));
888
889 data = stream.next_in = base_sha1 + 20;
890 stream.avail_in = left - 20;
891 stream.next_out = delta_head;
892 stream.avail_out = sizeof(delta_head);
893
894 inflateInit(&stream);
895 st = inflate(&stream, Z_FINISH);
896 inflateEnd(&stream);
897 if ((st != Z_STREAM_END) &&
898 stream.total_out != sizeof(delta_head))
899 die("delta data unpack-initial failed");
900
901 /* Examine the initial part of the delta to figure out
902 * the result size.
903 */
904 data = delta_head;
8960844a
NP
905
906 /* ignore base size */
907 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
5db47c2b 908
c62266f3 909 /* Read the result size */
8960844a 910 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
c62266f3
JH
911 *sizep = result_size;
912 }
5db47c2b
JH
913 return 0;
914}
915
a733cb60
LT
916static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
917 enum object_type *type, unsigned long *sizep)
918{
01247d87 919 unsigned shift;
465b26ee 920 unsigned char c;
a733cb60
LT
921 unsigned long size;
922
923 if (offset >= p->pack_size)
924 die("object offset outside of pack file");
465b26ee 925 c = *((unsigned char *)p->pack_base + offset++);
a733cb60
LT
926 *type = (c >> 4) & 7;
927 size = c & 15;
01247d87 928 shift = 4;
a733cb60
LT
929 while (c & 0x80) {
930 if (offset >= p->pack_size)
931 die("object offset outside of pack file");
465b26ee 932 c = *((unsigned char *)p->pack_base + offset++);
01247d87
LT
933 size += (c & 0x7f) << shift;
934 shift += 7;
a733cb60
LT
935 }
936 *sizep = size;
937 return offset;
938}
939
a49dd05f
JH
940int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
941 unsigned char *base, unsigned long *sizep,
942 enum object_type *kindp)
943{
944 unsigned long ptr;
945 int status = -1;
946
947 use_packed_git(p);
948 ptr = offset;
949 ptr = unpack_object_header(p, ptr, kindp, sizep);
950 if (*kindp != OBJ_DELTA)
951 goto done;
e702496e 952 hashcpy(base, (unsigned char *) p->pack_base + ptr);
a49dd05f
JH
953 status = 0;
954 done:
955 unuse_packed_git(p);
956 return status;
957}
958
ad8c80a5
JH
959void packed_object_info_detail(struct pack_entry *e,
960 char *type,
961 unsigned long *size,
962 unsigned long *store_size,
f8f135c9 963 unsigned int *delta_chain_length,
ad8c80a5
JH
964 unsigned char *base_sha1)
965{
966 struct packed_git *p = e->p;
2855d580 967 unsigned long offset;
ad8c80a5
JH
968 unsigned char *pack;
969 enum object_type kind;
970
971 offset = unpack_object_header(p, e->offset, &kind, size);
1d7f171c 972 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
973 if (kind != OBJ_DELTA)
974 *delta_chain_length = 0;
975 else {
f8f135c9 976 unsigned int chain_length = 0;
2855d580
JH
977 if (p->pack_size <= offset + 20)
978 die("pack file %s records an incomplete delta base",
979 p->pack_name);
e702496e 980 hashcpy(base_sha1, pack);
ad8c80a5
JH
981 do {
982 struct pack_entry base_ent;
983 unsigned long junk;
984
985 find_pack_entry_one(pack, &base_ent, p);
986 offset = unpack_object_header(p, base_ent.offset,
987 &kind, &junk);
1d7f171c 988 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
989 chain_length++;
990 } while (kind == OBJ_DELTA);
991 *delta_chain_length = chain_length;
992 }
993 switch (kind) {
994 case OBJ_COMMIT:
ad8c80a5 995 case OBJ_TREE:
ad8c80a5 996 case OBJ_BLOB:
ad8c80a5 997 case OBJ_TAG:
5a18f540 998 strcpy(type, type_names[kind]);
ad8c80a5
JH
999 break;
1000 default:
264b16b6
JH
1001 die("corrupted pack file %s containing object of kind %d",
1002 p->pack_name, kind);
ad8c80a5
JH
1003 }
1004 *store_size = 0; /* notyet */
1005}
1006
1f688557
JH
1007static int packed_object_info(struct pack_entry *entry,
1008 char *type, unsigned long *sizep)
1009{
1010 struct packed_git *p = entry->p;
1011 unsigned long offset, size, left;
1012 unsigned char *pack;
a733cb60 1013 enum object_type kind;
f9253394 1014 int retval;
5db47c2b
JH
1015
1016 if (use_packed_git(p))
1017 die("cannot map packed file");
1018
a733cb60 1019 offset = unpack_object_header(p, entry->offset, &kind, &size);
1d7f171c 1020 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
1021 left = p->pack_size - offset;
1022
1023 switch (kind) {
1024 case OBJ_DELTA:
f3bf9224 1025 retval = packed_delta_info(pack, size, left, type, sizep, p);
f9253394
JH
1026 unuse_packed_git(p);
1027 return retval;
a733cb60 1028 case OBJ_COMMIT:
a733cb60 1029 case OBJ_TREE:
a733cb60 1030 case OBJ_BLOB:
a733cb60 1031 case OBJ_TAG:
5a18f540 1032 strcpy(type, type_names[kind]);
a69d0943 1033 break;
1f688557 1034 default:
264b16b6
JH
1035 die("corrupted pack file %s containing object of kind %d",
1036 p->pack_name, kind);
1f688557 1037 }
c62266f3
JH
1038 if (sizep)
1039 *sizep = size;
f9253394 1040 unuse_packed_git(p);
1f688557
JH
1041 return 0;
1042}
1043
eb950c19
SP
1044static void *unpack_compressed_entry(struct packed_git *p,
1045 unsigned long offset,
1046 unsigned long size)
de530aaa
SP
1047{
1048 int st;
1049 z_stream stream;
1050 unsigned char *buffer;
1051
1052 buffer = xmalloc(size + 1);
1053 buffer[size] = 0;
1054 memset(&stream, 0, sizeof(stream));
eb950c19
SP
1055 stream.next_in = (unsigned char*)p->pack_base + offset;
1056 stream.avail_in = p->pack_size - offset;
de530aaa
SP
1057 stream.next_out = buffer;
1058 stream.avail_out = size;
1059
1060 inflateInit(&stream);
1061 st = inflate(&stream, Z_FINISH);
1062 inflateEnd(&stream);
1063 if ((st != Z_STREAM_END) || stream.total_out != size) {
1064 free(buffer);
1065 return NULL;
1066 }
1067
1068 return buffer;
1069}
1070
eb950c19
SP
1071static void *unpack_delta_entry(struct packed_git *p,
1072 unsigned long offset,
1f688557 1073 unsigned long delta_size,
1f688557 1074 char *type,
eb950c19 1075 unsigned long *sizep)
1f688557 1076{
f3bf9224 1077 struct pack_entry base_ent;
7c3e8be3
SP
1078 void *delta_data, *result, *base;
1079 unsigned long result_size, base_size;
eb950c19 1080 unsigned char* base_sha1;
1f688557 1081
eb950c19 1082 if ((offset + 20) >= p->pack_size)
1f688557 1083 die("truncated pack file");
67686d95
JH
1084
1085 /* The base entry _must_ be in the same pack */
eb950c19 1086 base_sha1 = (unsigned char*)p->pack_base + offset;
67686d95
JH
1087 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1088 die("failed to find delta-pack base object %s",
1089 sha1_to_hex(base_sha1));
1090 base = unpack_entry_gently(&base_ent, type, &base_size);
1091 if (!base)
1092 die("failed to read delta-pack base object %s",
1093 sha1_to_hex(base_sha1));
1094
eb950c19 1095 delta_data = unpack_compressed_entry(p, offset + 20, delta_size);
1f688557
JH
1096 result = patch_delta(base, base_size,
1097 delta_data, delta_size,
1098 &result_size);
1099 if (!result)
1100 die("failed to apply delta");
1101 free(delta_data);
1102 free(base);
1103 *sizep = result_size;
1104 return result;
1105}
1106
1f688557
JH
1107static void *unpack_entry(struct pack_entry *entry,
1108 char *type, unsigned long *sizep)
1109{
1110 struct packed_git *p = entry->p;
f9253394 1111 void *retval;
1f688557
JH
1112
1113 if (use_packed_git(p))
1114 die("cannot map packed file");
f3bf9224
JH
1115 retval = unpack_entry_gently(entry, type, sizep);
1116 unuse_packed_git(p);
1117 if (!retval)
264b16b6 1118 die("corrupted pack file %s", p->pack_name);
f3bf9224
JH
1119 return retval;
1120}
1121
1122/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1123void *unpack_entry_gently(struct pack_entry *entry,
1124 char *type, unsigned long *sizep)
1125{
1126 struct packed_git *p = entry->p;
eb950c19 1127 unsigned long offset, size;
f3bf9224 1128 enum object_type kind;
1f688557 1129
a733cb60 1130 offset = unpack_object_header(p, entry->offset, &kind, &size);
a733cb60
LT
1131 switch (kind) {
1132 case OBJ_DELTA:
eb950c19 1133 return unpack_delta_entry(p, offset, size, type, sizep);
a733cb60 1134 case OBJ_COMMIT:
a733cb60 1135 case OBJ_TREE:
a733cb60 1136 case OBJ_BLOB:
a733cb60 1137 case OBJ_TAG:
5a18f540
SP
1138 strcpy(type, type_names[kind]);
1139 *sizep = size;
eb950c19 1140 return unpack_compressed_entry(p, offset, size);
1f688557 1141 default:
f3bf9224 1142 return NULL;
1f688557 1143 }
1f688557
JH
1144}
1145
9a217f2a
JH
1146int num_packed_objects(const struct packed_git *p)
1147{
f9253394 1148 /* See check_packed_git_idx() */
9a217f2a
JH
1149 return (p->index_size - 20 - 20 - 4*256) / 24;
1150}
1151
1152int nth_packed_object_sha1(const struct packed_git *p, int n,
1153 unsigned char* sha1)
1154{
1155 void *index = p->index_base + 256;
1156 if (n < 0 || num_packed_objects(p) <= n)
1157 return -1;
e702496e 1158 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
9a217f2a
JH
1159 return 0;
1160}
1161
f3bf9224
JH
1162int find_pack_entry_one(const unsigned char *sha1,
1163 struct pack_entry *e, struct packed_git *p)
1f688557 1164{
4d235c80 1165 unsigned int *level1_ofs = p->index_base;
1f688557
JH
1166 int hi = ntohl(level1_ofs[*sha1]);
1167 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1168 void *index = p->index_base + 256;
1169
1170 do {
1171 int mi = (lo + hi) / 2;
a89fccd2 1172 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1f688557 1173 if (!cmp) {
1d7f171c 1174 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
e702496e 1175 hashcpy(e->sha1, sha1);
1f688557
JH
1176 e->p = p;
1177 return 1;
1178 }
1179 if (cmp > 0)
1180 hi = mi;
1181 else
1182 lo = mi+1;
1183 } while (lo < hi);
1184 return 0;
1185}
1186
1187static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1188{
1189 struct packed_git *p;
1190 prepare_packed_git();
1191
1192 for (p = packed_git; p; p = p->next) {
f3bf9224 1193 if (find_pack_entry_one(sha1, e, p))
1f688557
JH
1194 return 1;
1195 }
1196 return 0;
1197}
1198
bf592c50
DB
1199struct packed_git *find_sha1_pack(const unsigned char *sha1,
1200 struct packed_git *packs)
1201{
1202 struct packed_git *p;
1203 struct pack_entry e;
1204
1205 for (p = packs; p; p = p->next) {
1206 if (find_pack_entry_one(sha1, &e, p))
1207 return p;
1208 }
1209 return NULL;
1210
1211}
1212
36e4d74a 1213int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1214{
36e4d74a 1215 int status;
65c2e0c3
JH
1216 unsigned long mapsize, size;
1217 void *map;
1218 z_stream stream;
36e4d74a 1219 char hdr[128];
65c2e0c3 1220
bb6b8e4f 1221 map = map_sha1_file(sha1, &mapsize);
1f688557
JH
1222 if (!map) {
1223 struct pack_entry e;
1224
637cdd9d
JK
1225 if (find_pack_entry(sha1, &e))
1226 return packed_object_info(&e, type, sizep);
1227 reprepare_packed_git();
1228 if (find_pack_entry(sha1, &e))
1229 return packed_object_info(&e, type, sizep);
1230 return error("unable to find %s", sha1_to_hex(sha1));
1f688557 1231 }
36e4d74a
JH
1232 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1233 status = error("unable to unpack %s header",
1234 sha1_to_hex(sha1));
1235 if (parse_sha1_header(hdr, type, &size) < 0)
1236 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1237 else {
65c2e0c3 1238 status = 0;
c62266f3
JH
1239 if (sizep)
1240 *sizep = size;
65c2e0c3 1241 }
65c2e0c3
JH
1242 inflateEnd(&stream);
1243 munmap(map, mapsize);
1244 return status;
1245}
1246
1f688557
JH
1247static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1248{
1249 struct pack_entry e;
1250
1251 if (!find_pack_entry(sha1, &e)) {
1252 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1253 return NULL;
1254 }
1255 return unpack_entry(&e, type, size);
1256}
1257
0fcfd160
LT
1258void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1259{
1260 unsigned long mapsize;
1261 void *map, *buf;
ab90ea5d 1262 struct pack_entry e;
0fcfd160 1263
ab90ea5d
JH
1264 if (find_pack_entry(sha1, &e))
1265 return read_packed_sha1(sha1, type, size);
bb6b8e4f 1266 map = map_sha1_file(sha1, &mapsize);
0fcfd160
LT
1267 if (map) {
1268 buf = unpack_sha1_file(map, mapsize, type, size);
1269 munmap(map, mapsize);
1270 return buf;
1271 }
637cdd9d
JK
1272 reprepare_packed_git();
1273 if (find_pack_entry(sha1, &e))
1274 return read_packed_sha1(sha1, type, size);
ab90ea5d 1275 return NULL;
0fcfd160
LT
1276}
1277
40469ee9 1278void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1279 const char *required_type,
40469ee9
JH
1280 unsigned long *size,
1281 unsigned char *actual_sha1_return)
f4913f91
JH
1282{
1283 char type[20];
1284 void *buffer;
1285 unsigned long isize;
40469ee9 1286 unsigned char actual_sha1[20];
f4913f91 1287
e702496e 1288 hashcpy(actual_sha1, sha1);
40469ee9
JH
1289 while (1) {
1290 int ref_length = -1;
1291 const char *ref_type = NULL;
f4913f91 1292
40469ee9
JH
1293 buffer = read_sha1_file(actual_sha1, type, &isize);
1294 if (!buffer)
1295 return NULL;
1296 if (!strcmp(type, required_type)) {
1297 *size = isize;
1298 if (actual_sha1_return)
e702496e 1299 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1300 return buffer;
1301 }
1302 /* Handle references */
8e440259 1303 else if (!strcmp(type, commit_type))
40469ee9 1304 ref_type = "tree ";
8e440259 1305 else if (!strcmp(type, tag_type))
40469ee9
JH
1306 ref_type = "object ";
1307 else {
1308 free(buffer);
1309 return NULL;
1310 }
1311 ref_length = strlen(ref_type);
f4913f91 1312
40469ee9 1313 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1314 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1315 free(buffer);
1316 return NULL;
1317 }
1cf58e72 1318 free(buffer);
40469ee9
JH
1319 /* Now we have the ID of the referred-to object in
1320 * actual_sha1. Check again. */
f4913f91 1321 }
f4913f91
JH
1322}
1323
7672db20
BL
1324char *write_sha1_file_prepare(void *buf,
1325 unsigned long len,
1326 const char *type,
1327 unsigned char *sha1,
1328 unsigned char *hdr,
1329 int *hdrlen)
d410c0f5
JH
1330{
1331 SHA_CTX c;
1332
1333 /* Generate the header */
1334 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1335
1336 /* Sha1.. */
1337 SHA1_Init(&c);
1338 SHA1_Update(&c, hdr, *hdrlen);
1339 SHA1_Update(&c, buf, len);
1340 SHA1_Final(sha1, &c);
1341
1342 return sha1_file_name(sha1);
1343}
1344
230f1322
LT
1345/*
1346 * Link the tempfile to the final place, possibly creating the
1347 * last directory level as you do so.
1348 *
1349 * Returns the errno on failure, 0 on success.
1350 */
839837b9 1351static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1352{
1353 int ret;
756aaf4a 1354 char *dir;
230f1322
LT
1355
1356 if (!link(tmpfile, filename))
1357 return 0;
1358
1359 /*
756aaf4a 1360 * Try to mkdir the last path component if that failed.
230f1322
LT
1361 *
1362 * Re-try the "link()" regardless of whether the mkdir
1363 * succeeds, since a race might mean that somebody
1364 * else succeeded.
1365 */
1366 ret = errno;
756aaf4a
SP
1367 dir = strrchr(filename, '/');
1368 if (dir) {
1369 *dir = 0;
1370 mkdir(filename, 0777);
1371 if (adjust_shared_perm(filename))
1372 return -2;
1373 *dir = '/';
1374 if (!link(tmpfile, filename))
1375 return 0;
1376 ret = errno;
230f1322
LT
1377 }
1378 return ret;
1379}
1380
1381/*
1382 * Move the just written object into its final resting place
1383 */
839837b9 1384int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1385{
1386 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
1387
1388 /*
1389 * Coda hack - coda doesn't like cross-directory links,
1390 * so we fall back to a rename, which will mean that it
1391 * won't be able to check collisions, but that's not a
1392 * big deal.
1393 *
1394 * The same holds for FAT formatted media.
1395 *
1396 * When this succeeds, we just return 0. We have nothing
1397 * left to unlink.
1398 */
1399 if (ret && ret != EEXIST) {
1400 if (!rename(tmpfile, filename))
230f1322 1401 return 0;
9e48b389 1402 ret = errno;
230f1322
LT
1403 }
1404 unlink(tmpfile);
1405 if (ret) {
1406 if (ret != EEXIST) {
7246ed43 1407 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
1408 return -1;
1409 }
1410 /* FIXME!!! Collision check here ? */
1411 }
1412
1413 return 0;
1414}
1415
4d548150
LT
1416static int write_buffer(int fd, const void *buf, size_t len)
1417{
1418 while (len) {
1419 ssize_t size;
1420
1421 size = write(fd, buf, len);
1422 if (!size)
1423 return error("file write: disk full");
1424 if (size < 0) {
1425 if (errno == EINTR || errno == EAGAIN)
1426 continue;
1427 return error("file write error (%s)", strerror(errno));
1428 }
1429 len -= size;
1d7f171c 1430 buf = (char *) buf + size;
4d548150
LT
1431 }
1432 return 0;
1433}
1434
93821bd9
LT
1435static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1436{
1437 int hdr_len;
1438 unsigned char c;
1439
1440 c = (type << 4) | (len & 15);
1441 len >>= 4;
1442 hdr_len = 1;
1443 while (len) {
1444 *hdr++ = c | 0x80;
1445 hdr_len++;
1446 c = (len & 0x7f);
1447 len >>= 7;
1448 }
1449 *hdr = c;
1450 return hdr_len;
1451}
1452
1453static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1454{
1455 int obj_type, hdr;
1456
1457 if (use_legacy_headers) {
1458 while (deflate(stream, 0) == Z_OK)
1459 /* nothing */;
1460 return;
1461 }
1462 if (!strcmp(type, blob_type))
1463 obj_type = OBJ_BLOB;
1464 else if (!strcmp(type, tree_type))
1465 obj_type = OBJ_TREE;
1466 else if (!strcmp(type, commit_type))
1467 obj_type = OBJ_COMMIT;
1468 else if (!strcmp(type, tag_type))
1469 obj_type = OBJ_TAG;
1470 else
1471 die("trying to generate bogus object of type '%s'", type);
1472 hdr = write_binary_header(stream->next_out, obj_type, len);
1473 stream->total_out = hdr;
1474 stream->next_out += hdr;
1475 stream->avail_out -= hdr;
1476}
1477
bf0f910d 1478int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1479{
1480 int size;
bf0f910d 1481 unsigned char *compressed;
0fcfd160
LT
1482 z_stream stream;
1483 unsigned char sha1[20];
706bc531 1484 char *filename;
aac17941 1485 static char tmpfile[PATH_MAX];
bf0f910d 1486 unsigned char hdr[50];
230f1322 1487 int fd, hdrlen;
a44c9a5e 1488
d410c0f5
JH
1489 /* Normally if we have it in the pack then we do not bother writing
1490 * it out into .git/objects/??/?{38} file.
1491 */
1492 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
706bc531 1493 if (returnsha1)
e702496e 1494 hashcpy(returnsha1, sha1);
d410c0f5
JH
1495 if (has_sha1_file(sha1))
1496 return 0;
aac17941
LT
1497 fd = open(filename, O_RDONLY);
1498 if (fd >= 0) {
706bc531 1499 /*
aac17941
LT
1500 * FIXME!!! We might do collision checking here, but we'd
1501 * need to uncompress the old file and check it. Later.
706bc531 1502 */
aac17941 1503 close(fd);
706bc531
LT
1504 return 0;
1505 }
1506
aac17941 1507 if (errno != ENOENT) {
7246ed43 1508 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
1509 return -1;
1510 }
1511
1512 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1513
aac17941
LT
1514 fd = mkstemp(tmpfile);
1515 if (fd < 0) {
7246ed43 1516 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
1517 return -1;
1518 }
1519
0fcfd160
LT
1520 /* Set it up */
1521 memset(&stream, 0, sizeof(stream));
12f6c308 1522 deflateInit(&stream, zlib_compression_level);
93821bd9 1523 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 1524 compressed = xmalloc(size);
0fcfd160
LT
1525
1526 /* Compress it */
0fcfd160
LT
1527 stream.next_out = compressed;
1528 stream.avail_out = size;
a44c9a5e
LT
1529
1530 /* First header.. */
1531 stream.next_in = hdr;
1532 stream.avail_in = hdrlen;
93821bd9 1533 setup_object_header(&stream, type, len);
a44c9a5e
LT
1534
1535 /* Then the data itself.. */
1536 stream.next_in = buf;
1537 stream.avail_in = len;
0fcfd160
LT
1538 while (deflate(&stream, Z_FINISH) == Z_OK)
1539 /* nothing */;
1540 deflateEnd(&stream);
1541 size = stream.total_out;
1542
4d548150
LT
1543 if (write_buffer(fd, compressed, size) < 0)
1544 die("unable to write sha1 file");
aac17941 1545 fchmod(fd, 0444);
706bc531 1546 close(fd);
383f85b7 1547 free(compressed);
0fcfd160 1548
230f1322 1549 return move_temp_to_file(tmpfile, filename);
0fcfd160 1550}
8237b185 1551
4d548150
LT
1552/*
1553 * We need to unpack and recompress the object for writing
1554 * it out to a different file.
1555 */
1556static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 1557{
4d548150 1558 size_t size;
a5eda52b 1559 z_stream stream;
4d548150
LT
1560 unsigned char *unpacked;
1561 unsigned long len;
1562 char type[20];
1563 char hdr[50];
1564 int hdrlen;
1565 void *buf;
bfc66daf 1566
a9486b02 1567 /* need to unpack and recompress it by itself */
4d548150 1568 unpacked = read_packed_sha1(sha1, type, &len);
a5eda52b 1569
4d548150 1570 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
a5eda52b 1571
4d548150
LT
1572 /* Set it up */
1573 memset(&stream, 0, sizeof(stream));
12f6c308 1574 deflateInit(&stream, zlib_compression_level);
4d548150
LT
1575 size = deflateBound(&stream, len + hdrlen);
1576 buf = xmalloc(size);
a5eda52b 1577
4d548150
LT
1578 /* Compress it */
1579 stream.next_out = buf;
1580 stream.avail_out = size;
a5eda52b 1581
4d548150
LT
1582 /* First header.. */
1583 stream.next_in = (void *)hdr;
1584 stream.avail_in = hdrlen;
1585 while (deflate(&stream, 0) == Z_OK)
1586 /* nothing */;
bfc66daf 1587
4d548150
LT
1588 /* Then the data itself.. */
1589 stream.next_in = unpacked;
1590 stream.avail_in = len;
1591 while (deflate(&stream, Z_FINISH) == Z_OK)
1592 /* nothing */;
1593 deflateEnd(&stream);
1594 free(unpacked);
bfc66daf 1595
4d548150
LT
1596 *objsize = stream.total_out;
1597 return buf;
1598}
1599
1600int write_sha1_to_fd(int fd, const unsigned char *sha1)
1601{
1602 int retval;
1603 unsigned long objsize;
bb6b8e4f 1604 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
1605
1606 if (buf) {
1607 retval = write_buffer(fd, buf, objsize);
1608 munmap(buf, objsize);
1609 return retval;
1610 }
1611
1612 buf = repack_object(sha1, &objsize);
1613 retval = write_buffer(fd, buf, objsize);
1614 free(buf);
1615 return retval;
a5eda52b
DB
1616}
1617
70b9829e
DB
1618int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1619 size_t bufsize, size_t *bufposn)
8237b185 1620{
230f1322 1621 char tmpfile[PATH_MAX];
8237b185
DB
1622 int local;
1623 z_stream stream;
1624 unsigned char real_sha1[20];
bf0f910d 1625 unsigned char discard[4096];
8237b185
DB
1626 int ret;
1627 SHA_CTX c;
1628
230f1322 1629 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
8237b185 1630
230f1322 1631 local = mkstemp(tmpfile);
8237b185 1632 if (local < 0)
bd2afde8
JH
1633 return error("Couldn't open %s for %s",
1634 tmpfile, sha1_to_hex(sha1));
8237b185
DB
1635
1636 memset(&stream, 0, sizeof(stream));
1637
1638 inflateInit(&stream);
1639
1640 SHA1_Init(&c);
1641
1642 do {
1643 ssize_t size;
70b9829e
DB
1644 if (*bufposn) {
1645 stream.avail_in = *bufposn;
96ad15ae 1646 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
1647 do {
1648 stream.next_out = discard;
1649 stream.avail_out = sizeof(discard);
1650 ret = inflate(&stream, Z_SYNC_FLUSH);
1651 SHA1_Update(&c, discard, sizeof(discard) -
1652 stream.avail_out);
1653 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
1654 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1655 die("unable to write sha1 file");
70b9829e
DB
1656 memmove(buffer, buffer + *bufposn - stream.avail_in,
1657 stream.avail_in);
1658 *bufposn = stream.avail_in;
1659 if (ret != Z_OK)
1660 break;
1661 }
1662 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
1663 if (size <= 0) {
1664 close(local);
230f1322 1665 unlink(tmpfile);
8237b185
DB
1666 if (!size)
1667 return error("Connection closed?");
1668 perror("Reading from connection");
1669 return -1;
1670 }
70b9829e
DB
1671 *bufposn += size;
1672 } while (1);
8237b185
DB
1673 inflateEnd(&stream);
1674
1675 close(local);
1676 SHA1_Final(real_sha1, &c);
1677 if (ret != Z_STREAM_END) {
230f1322 1678 unlink(tmpfile);
8237b185
DB
1679 return error("File %s corrupted", sha1_to_hex(sha1));
1680 }
a89fccd2 1681 if (hashcmp(sha1, real_sha1)) {
230f1322 1682 unlink(tmpfile);
bd2afde8 1683 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 1684 }
230f1322
LT
1685
1686 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
1687}
1688
bf592c50
DB
1689int has_pack_index(const unsigned char *sha1)
1690{
1691 struct stat st;
1692 if (stat(sha1_pack_index_name(sha1), &st))
1693 return 0;
1694 return 1;
1695}
1696
1697int has_pack_file(const unsigned char *sha1)
1698{
1699 struct stat st;
1700 if (stat(sha1_pack_name(sha1), &st))
1701 return 0;
1702 return 1;
1703}
1704
dade09c2
LT
1705int has_sha1_pack(const unsigned char *sha1)
1706{
1707 struct pack_entry e;
1708 return find_pack_entry(sha1, &e);
1709}
1710
8237b185
DB
1711int has_sha1_file(const unsigned char *sha1)
1712{
8237b185 1713 struct stat st;
1f688557
JH
1714 struct pack_entry e;
1715
ab90ea5d 1716 if (find_pack_entry(sha1, &e))
1f688557 1717 return 1;
ab90ea5d 1718 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 1719}
74400e71 1720
e7332f96
BE
1721/*
1722 * reads from fd as long as possible into a supplied buffer of size bytes.
82e5a82f 1723 * If necessary the buffer's size is increased using realloc()
e7332f96
BE
1724 *
1725 * returns 0 if anything went fine and -1 otherwise
1726 *
1727 * NOTE: both buf and size may change, but even when -1 is returned
1728 * you still have to free() it yourself.
1729 */
1730int read_pipe(int fd, char** return_buf, unsigned long* return_size)
024510c8 1731{
e7332f96
BE
1732 char* buf = *return_buf;
1733 unsigned long size = *return_size;
1734 int iret;
024510c8 1735 unsigned long off = 0;
e7332f96 1736
024510c8 1737 do {
e7332f96 1738 iret = xread(fd, buf + off, size - off);
024510c8
DB
1739 if (iret > 0) {
1740 off += iret;
1741 if (off == size) {
1742 size *= 2;
83572c1a 1743 buf = xrealloc(buf, size);
024510c8
DB
1744 }
1745 }
1746 } while (iret > 0);
e7332f96
BE
1747
1748 *return_buf = buf;
1749 *return_size = off;
1750
1751 if (iret < 0)
1752 return -1;
1753 return 0;
1754}
1755
1756int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1757{
1758 unsigned long size = 4096;
2d7320d0 1759 char *buf = xmalloc(size);
e7332f96
BE
1760 int ret;
1761 unsigned char hdr[50];
1762 int hdrlen;
1763
1764 if (read_pipe(fd, &buf, &size)) {
024510c8
DB
1765 free(buf);
1766 return -1;
1767 }
e7332f96 1768
024510c8 1769 if (!type)
8e440259 1770 type = blob_type;
024510c8 1771 if (write_object)
e7332f96 1772 ret = write_sha1_file(buf, size, type, sha1);
024510c8 1773 else {
e7332f96 1774 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
024510c8
DB
1775 ret = 0;
1776 }
1777 free(buf);
1778 return ret;
1779}
1780
7672db20 1781int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
74400e71 1782{
74400e71 1783 unsigned long size = st->st_size;
aac17941
LT
1784 void *buf;
1785 int ret;
7672db20
BL
1786 unsigned char hdr[50];
1787 int hdrlen;
74400e71 1788
aac17941 1789 buf = "";
74400e71 1790 if (size)
aac17941 1791 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1792 close(fd);
e35f9824 1793 if (buf == MAP_FAILED)
74400e71
JH
1794 return -1;
1795
7672db20 1796 if (!type)
8e440259 1797 type = blob_type;
7672db20
BL
1798 if (write_object)
1799 ret = write_sha1_file(buf, size, type, sha1);
1800 else {
1801 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1802 ret = 0;
1803 }
aac17941
LT
1804 if (size)
1805 munmap(buf, size);
1806 return ret;
74400e71 1807}
ec1fcc16
JH
1808
1809int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1810{
1811 int fd;
1812 char *target;
1813
1814 switch (st->st_mode & S_IFMT) {
1815 case S_IFREG:
1816 fd = open(path, O_RDONLY);
1817 if (fd < 0)
1818 return error("open(\"%s\"): %s", path,
1819 strerror(errno));
1820 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1821 return error("%s: failed to insert into database",
1822 path);
1823 break;
1824 case S_IFLNK:
1825 target = xmalloc(st->st_size+1);
1826 if (readlink(path, target, st->st_size+1) != st->st_size) {
1827 char *errstr = strerror(errno);
1828 free(target);
1829 return error("readlink(\"%s\"): %s", path,
1830 errstr);
1831 }
1832 if (!write_object) {
1833 unsigned char hdr[50];
1834 int hdrlen;
8e440259 1835 write_sha1_file_prepare(target, st->st_size, blob_type,
ec1fcc16 1836 sha1, hdr, &hdrlen);
8e440259 1837 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
ec1fcc16
JH
1838 return error("%s: failed to insert into database",
1839 path);
1840 free(target);
1841 break;
1842 default:
1843 return error("%s: unsupported file type", path);
1844 }
1845 return 0;
1846}