pack-objects: further work on internal rev-list logic.
[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
9befac47 118 * careful about using it. Do a "xstrdup()" if you need to save the
0fcfd160 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
72518e9c 714unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 715{
ad1ed5ee 716 unsigned shift;
93821bd9 717 unsigned char c;
93821bd9 718 unsigned long size;
ad1ed5ee
JH
719 unsigned long used = 0;
720
721 c = buf[used++];
722 *type = (c >> 4) & 7;
723 size = c & 15;
724 shift = 4;
725 while (c & 0x80) {
726 if (len <= used)
727 return 0;
728 if (sizeof(long) * 8 <= shift)
729 return 0;
730 c = buf[used++];
731 size += (c & 0x7f) << shift;
732 shift += 7;
733 }
734 *sizep = size;
735 return used;
736}
737
738static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
739{
740 unsigned long size, used;
741 static const char valid_loose_object_type[8] = {
742 0, /* OBJ_EXT */
743 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
744 0, /* "delta" and others are invalid in a loose object */
93821bd9 745 };
ad1ed5ee 746 enum object_type type;
93821bd9 747
c4483576
LT
748 /* Get the data stream */
749 memset(stream, 0, sizeof(*stream));
750 stream->next_in = map;
751 stream->avail_in = mapsize;
752 stream->next_out = buffer;
93821bd9
LT
753 stream->avail_out = bufsiz;
754
bb6b8e4f 755 if (legacy_loose_object(map)) {
93821bd9
LT
756 inflateInit(stream);
757 return inflate(stream, 0);
758 }
759
ad1ed5ee
JH
760 used = unpack_object_header_gently(map, mapsize, &type, &size);
761 if (!used || !valid_loose_object_type[type])
93821bd9 762 return -1;
ad1ed5ee
JH
763 map += used;
764 mapsize -= used;
93821bd9
LT
765
766 /* Set up the stream for the rest.. */
767 stream->next_in = map;
768 stream->avail_in = mapsize;
c4483576 769 inflateInit(stream);
93821bd9
LT
770
771 /* And generate the fake traditional header */
ad1ed5ee
JH
772 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
773 type_names[type], size);
93821bd9 774 return 0;
c4483576
LT
775}
776
6da4016a 777static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
5180cacc
LT
778{
779 int bytes = strlen(buffer) + 1;
d565b341 780 unsigned char *buf = xmalloc(1+size);
93821bd9 781 unsigned long n;
5180cacc 782
93821bd9
LT
783 n = stream->total_out - bytes;
784 if (n > size)
785 n = size;
786 memcpy(buf, (char *) buffer + bytes, n);
787 bytes = n;
5180cacc
LT
788 if (bytes < size) {
789 stream->next_out = buf + bytes;
790 stream->avail_out = size - bytes;
791 while (inflate(stream, Z_FINISH) == Z_OK)
792 /* nothing */;
793 }
794 buf[size] = 0;
795 inflateEnd(stream);
796 return buf;
797}
798
799/*
800 * We used to just use "sscanf()", but that's actually way
801 * too permissive for what we want to check. So do an anal
802 * object header parse by hand.
803 */
38d3874d 804static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
5180cacc
LT
805{
806 int i;
807 unsigned long size;
808
809 /*
810 * The type can be at most ten bytes (including the
811 * terminating '\0' that we add), and is followed by
812 * a space.
813 */
814 i = 10;
815 for (;;) {
816 char c = *hdr++;
817 if (c == ' ')
818 break;
819 if (!--i)
820 return -1;
821 *type++ = c;
822 }
823 *type = 0;
824
825 /*
826 * The length must follow immediately, and be in canonical
827 * decimal format (ie "010" is not valid).
828 */
829 size = *hdr++ - '0';
830 if (size > 9)
831 return -1;
832 if (size) {
833 for (;;) {
834 unsigned long c = *hdr - '0';
835 if (c > 9)
836 break;
837 hdr++;
838 size = size * 10 + c;
839 }
840 }
841 *sizep = size;
842
843 /*
844 * The length must be followed by a zero byte
845 */
846 return *hdr ? -1 : 0;
847}
848
0fcfd160
LT
849void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
850{
5180cacc 851 int ret;
0fcfd160 852 z_stream stream;
5180cacc 853 char hdr[8192];
0fcfd160 854
5180cacc
LT
855 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
856 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
857 return NULL;
858
5180cacc 859 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
860}
861
f3bf9224
JH
862/* forward declaration for a mutually recursive function */
863static int packed_object_info(struct pack_entry *entry,
864 char *type, unsigned long *sizep);
865
5db47c2b
JH
866static int packed_delta_info(unsigned char *base_sha1,
867 unsigned long delta_size,
868 unsigned long left,
869 char *type,
f3bf9224
JH
870 unsigned long *sizep,
871 struct packed_git *p)
5db47c2b 872{
f3bf9224
JH
873 struct pack_entry base_ent;
874
5db47c2b
JH
875 if (left < 20)
876 die("truncated pack file");
5db47c2b 877
f3bf9224
JH
878 /* The base entry _must_ be in the same pack */
879 if (!find_pack_entry_one(base_sha1, &base_ent, p))
880 die("failed to find delta-pack base object %s",
881 sha1_to_hex(base_sha1));
882
c62266f3
JH
883 /* We choose to only get the type of the base object and
884 * ignore potentially corrupt pack file that expects the delta
885 * based on a base with a wrong size. This saves tons of
886 * inflate() calls.
887 */
5db47c2b 888
f3bf9224 889 if (packed_object_info(&base_ent, type, NULL))
c62266f3 890 die("cannot get info for delta-pack base");
5db47c2b 891
c62266f3
JH
892 if (sizep) {
893 const unsigned char *data;
894 unsigned char delta_head[64];
895 unsigned long result_size;
896 z_stream stream;
897 int st;
898
899 memset(&stream, 0, sizeof(stream));
900
901 data = stream.next_in = base_sha1 + 20;
902 stream.avail_in = left - 20;
903 stream.next_out = delta_head;
904 stream.avail_out = sizeof(delta_head);
905
906 inflateInit(&stream);
907 st = inflate(&stream, Z_FINISH);
908 inflateEnd(&stream);
909 if ((st != Z_STREAM_END) &&
910 stream.total_out != sizeof(delta_head))
911 die("delta data unpack-initial failed");
912
913 /* Examine the initial part of the delta to figure out
914 * the result size.
915 */
916 data = delta_head;
8960844a
NP
917
918 /* ignore base size */
919 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
5db47c2b 920
c62266f3 921 /* Read the result size */
8960844a 922 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
c62266f3
JH
923 *sizep = result_size;
924 }
5db47c2b
JH
925 return 0;
926}
927
a733cb60
LT
928static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
929 enum object_type *type, unsigned long *sizep)
930{
ad1ed5ee 931 unsigned long used;
a733cb60 932
ad1ed5ee 933 if (p->pack_size <= offset)
a733cb60 934 die("object offset outside of pack file");
ad1ed5ee
JH
935
936 used = unpack_object_header_gently((unsigned char *)p->pack_base +
937 offset,
938 p->pack_size - offset, type, sizep);
939 if (!used)
940 die("object offset outside of pack file");
941
942 return offset + used;
a733cb60
LT
943}
944
a49dd05f
JH
945int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
946 unsigned char *base, unsigned long *sizep,
947 enum object_type *kindp)
948{
949 unsigned long ptr;
950 int status = -1;
951
952 use_packed_git(p);
953 ptr = offset;
954 ptr = unpack_object_header(p, ptr, kindp, sizep);
955 if (*kindp != OBJ_DELTA)
956 goto done;
e702496e 957 hashcpy(base, (unsigned char *) p->pack_base + ptr);
a49dd05f
JH
958 status = 0;
959 done:
960 unuse_packed_git(p);
961 return status;
962}
963
ad8c80a5
JH
964void packed_object_info_detail(struct pack_entry *e,
965 char *type,
966 unsigned long *size,
967 unsigned long *store_size,
f8f135c9 968 unsigned int *delta_chain_length,
ad8c80a5
JH
969 unsigned char *base_sha1)
970{
971 struct packed_git *p = e->p;
2855d580 972 unsigned long offset;
ad8c80a5
JH
973 unsigned char *pack;
974 enum object_type kind;
975
976 offset = unpack_object_header(p, e->offset, &kind, size);
1d7f171c 977 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
978 if (kind != OBJ_DELTA)
979 *delta_chain_length = 0;
980 else {
f8f135c9 981 unsigned int chain_length = 0;
2855d580
JH
982 if (p->pack_size <= offset + 20)
983 die("pack file %s records an incomplete delta base",
984 p->pack_name);
e702496e 985 hashcpy(base_sha1, pack);
ad8c80a5
JH
986 do {
987 struct pack_entry base_ent;
988 unsigned long junk;
989
990 find_pack_entry_one(pack, &base_ent, p);
991 offset = unpack_object_header(p, base_ent.offset,
992 &kind, &junk);
1d7f171c 993 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
994 chain_length++;
995 } while (kind == OBJ_DELTA);
996 *delta_chain_length = chain_length;
997 }
998 switch (kind) {
999 case OBJ_COMMIT:
ad8c80a5 1000 case OBJ_TREE:
ad8c80a5 1001 case OBJ_BLOB:
ad8c80a5 1002 case OBJ_TAG:
5a18f540 1003 strcpy(type, type_names[kind]);
ad8c80a5
JH
1004 break;
1005 default:
264b16b6
JH
1006 die("corrupted pack file %s containing object of kind %d",
1007 p->pack_name, kind);
ad8c80a5
JH
1008 }
1009 *store_size = 0; /* notyet */
1010}
1011
1f688557
JH
1012static int packed_object_info(struct pack_entry *entry,
1013 char *type, unsigned long *sizep)
1014{
1015 struct packed_git *p = entry->p;
1016 unsigned long offset, size, left;
1017 unsigned char *pack;
a733cb60 1018 enum object_type kind;
f9253394 1019 int retval;
5db47c2b
JH
1020
1021 if (use_packed_git(p))
1022 die("cannot map packed file");
1023
a733cb60 1024 offset = unpack_object_header(p, entry->offset, &kind, &size);
1d7f171c 1025 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
1026 left = p->pack_size - offset;
1027
1028 switch (kind) {
1029 case OBJ_DELTA:
f3bf9224 1030 retval = packed_delta_info(pack, size, left, type, sizep, p);
f9253394
JH
1031 unuse_packed_git(p);
1032 return retval;
a733cb60 1033 case OBJ_COMMIT:
a733cb60 1034 case OBJ_TREE:
a733cb60 1035 case OBJ_BLOB:
a733cb60 1036 case OBJ_TAG:
5a18f540 1037 strcpy(type, type_names[kind]);
a69d0943 1038 break;
1f688557 1039 default:
264b16b6
JH
1040 die("corrupted pack file %s containing object of kind %d",
1041 p->pack_name, kind);
1f688557 1042 }
c62266f3
JH
1043 if (sizep)
1044 *sizep = size;
f9253394 1045 unuse_packed_git(p);
1f688557
JH
1046 return 0;
1047}
1048
eb950c19
SP
1049static void *unpack_compressed_entry(struct packed_git *p,
1050 unsigned long offset,
1051 unsigned long size)
de530aaa
SP
1052{
1053 int st;
1054 z_stream stream;
1055 unsigned char *buffer;
1056
1057 buffer = xmalloc(size + 1);
1058 buffer[size] = 0;
1059 memset(&stream, 0, sizeof(stream));
eb950c19
SP
1060 stream.next_in = (unsigned char*)p->pack_base + offset;
1061 stream.avail_in = p->pack_size - offset;
de530aaa
SP
1062 stream.next_out = buffer;
1063 stream.avail_out = size;
1064
1065 inflateInit(&stream);
1066 st = inflate(&stream, Z_FINISH);
1067 inflateEnd(&stream);
1068 if ((st != Z_STREAM_END) || stream.total_out != size) {
1069 free(buffer);
1070 return NULL;
1071 }
1072
1073 return buffer;
1074}
1075
eb950c19
SP
1076static void *unpack_delta_entry(struct packed_git *p,
1077 unsigned long offset,
1f688557 1078 unsigned long delta_size,
1f688557 1079 char *type,
eb950c19 1080 unsigned long *sizep)
1f688557 1081{
f3bf9224 1082 struct pack_entry base_ent;
7c3e8be3
SP
1083 void *delta_data, *result, *base;
1084 unsigned long result_size, base_size;
eb950c19 1085 unsigned char* base_sha1;
1f688557 1086
eb950c19 1087 if ((offset + 20) >= p->pack_size)
1f688557 1088 die("truncated pack file");
67686d95
JH
1089
1090 /* The base entry _must_ be in the same pack */
eb950c19 1091 base_sha1 = (unsigned char*)p->pack_base + offset;
67686d95
JH
1092 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1093 die("failed to find delta-pack base object %s",
1094 sha1_to_hex(base_sha1));
1095 base = unpack_entry_gently(&base_ent, type, &base_size);
1096 if (!base)
1097 die("failed to read delta-pack base object %s",
1098 sha1_to_hex(base_sha1));
1099
eb950c19 1100 delta_data = unpack_compressed_entry(p, offset + 20, delta_size);
1f688557
JH
1101 result = patch_delta(base, base_size,
1102 delta_data, delta_size,
1103 &result_size);
1104 if (!result)
1105 die("failed to apply delta");
1106 free(delta_data);
1107 free(base);
1108 *sizep = result_size;
1109 return result;
1110}
1111
1f688557
JH
1112static void *unpack_entry(struct pack_entry *entry,
1113 char *type, unsigned long *sizep)
1114{
1115 struct packed_git *p = entry->p;
f9253394 1116 void *retval;
1f688557
JH
1117
1118 if (use_packed_git(p))
1119 die("cannot map packed file");
f3bf9224
JH
1120 retval = unpack_entry_gently(entry, type, sizep);
1121 unuse_packed_git(p);
1122 if (!retval)
264b16b6 1123 die("corrupted pack file %s", p->pack_name);
f3bf9224
JH
1124 return retval;
1125}
1126
1127/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1128void *unpack_entry_gently(struct pack_entry *entry,
1129 char *type, unsigned long *sizep)
1130{
1131 struct packed_git *p = entry->p;
eb950c19 1132 unsigned long offset, size;
f3bf9224 1133 enum object_type kind;
1f688557 1134
a733cb60 1135 offset = unpack_object_header(p, entry->offset, &kind, &size);
a733cb60
LT
1136 switch (kind) {
1137 case OBJ_DELTA:
eb950c19 1138 return unpack_delta_entry(p, offset, size, type, sizep);
a733cb60 1139 case OBJ_COMMIT:
a733cb60 1140 case OBJ_TREE:
a733cb60 1141 case OBJ_BLOB:
a733cb60 1142 case OBJ_TAG:
5a18f540
SP
1143 strcpy(type, type_names[kind]);
1144 *sizep = size;
eb950c19 1145 return unpack_compressed_entry(p, offset, size);
1f688557 1146 default:
f3bf9224 1147 return NULL;
1f688557 1148 }
1f688557
JH
1149}
1150
9a217f2a
JH
1151int num_packed_objects(const struct packed_git *p)
1152{
f9253394 1153 /* See check_packed_git_idx() */
9a217f2a
JH
1154 return (p->index_size - 20 - 20 - 4*256) / 24;
1155}
1156
1157int nth_packed_object_sha1(const struct packed_git *p, int n,
1158 unsigned char* sha1)
1159{
1160 void *index = p->index_base + 256;
1161 if (n < 0 || num_packed_objects(p) <= n)
1162 return -1;
e702496e 1163 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
9a217f2a
JH
1164 return 0;
1165}
1166
f3bf9224
JH
1167int find_pack_entry_one(const unsigned char *sha1,
1168 struct pack_entry *e, struct packed_git *p)
1f688557 1169{
4d235c80 1170 unsigned int *level1_ofs = p->index_base;
1f688557
JH
1171 int hi = ntohl(level1_ofs[*sha1]);
1172 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1173 void *index = p->index_base + 256;
1174
1175 do {
1176 int mi = (lo + hi) / 2;
a89fccd2 1177 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1f688557 1178 if (!cmp) {
1d7f171c 1179 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
e702496e 1180 hashcpy(e->sha1, sha1);
1f688557
JH
1181 e->p = p;
1182 return 1;
1183 }
1184 if (cmp > 0)
1185 hi = mi;
1186 else
1187 lo = mi+1;
1188 } while (lo < hi);
1189 return 0;
1190}
1191
1192static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1193{
1194 struct packed_git *p;
1195 prepare_packed_git();
1196
1197 for (p = packed_git; p; p = p->next) {
f3bf9224 1198 if (find_pack_entry_one(sha1, e, p))
1f688557
JH
1199 return 1;
1200 }
1201 return 0;
1202}
1203
bf592c50
DB
1204struct packed_git *find_sha1_pack(const unsigned char *sha1,
1205 struct packed_git *packs)
1206{
1207 struct packed_git *p;
1208 struct pack_entry e;
1209
1210 for (p = packs; p; p = p->next) {
1211 if (find_pack_entry_one(sha1, &e, p))
1212 return p;
1213 }
1214 return NULL;
1215
1216}
1217
36e4d74a 1218int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1219{
36e4d74a 1220 int status;
65c2e0c3
JH
1221 unsigned long mapsize, size;
1222 void *map;
1223 z_stream stream;
36e4d74a 1224 char hdr[128];
65c2e0c3 1225
bb6b8e4f 1226 map = map_sha1_file(sha1, &mapsize);
1f688557
JH
1227 if (!map) {
1228 struct pack_entry e;
1229
637cdd9d
JK
1230 if (find_pack_entry(sha1, &e))
1231 return packed_object_info(&e, type, sizep);
1232 reprepare_packed_git();
1233 if (find_pack_entry(sha1, &e))
1234 return packed_object_info(&e, type, sizep);
1235 return error("unable to find %s", sha1_to_hex(sha1));
1f688557 1236 }
36e4d74a
JH
1237 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1238 status = error("unable to unpack %s header",
1239 sha1_to_hex(sha1));
1240 if (parse_sha1_header(hdr, type, &size) < 0)
1241 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1242 else {
65c2e0c3 1243 status = 0;
c62266f3
JH
1244 if (sizep)
1245 *sizep = size;
65c2e0c3 1246 }
65c2e0c3
JH
1247 inflateEnd(&stream);
1248 munmap(map, mapsize);
1249 return status;
1250}
1251
1f688557
JH
1252static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1253{
1254 struct pack_entry e;
1255
1256 if (!find_pack_entry(sha1, &e)) {
1257 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1258 return NULL;
1259 }
1260 return unpack_entry(&e, type, size);
1261}
1262
0fcfd160
LT
1263void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1264{
1265 unsigned long mapsize;
1266 void *map, *buf;
ab90ea5d 1267 struct pack_entry e;
0fcfd160 1268
ab90ea5d
JH
1269 if (find_pack_entry(sha1, &e))
1270 return read_packed_sha1(sha1, type, size);
bb6b8e4f 1271 map = map_sha1_file(sha1, &mapsize);
0fcfd160
LT
1272 if (map) {
1273 buf = unpack_sha1_file(map, mapsize, type, size);
1274 munmap(map, mapsize);
1275 return buf;
1276 }
637cdd9d
JK
1277 reprepare_packed_git();
1278 if (find_pack_entry(sha1, &e))
1279 return read_packed_sha1(sha1, type, size);
ab90ea5d 1280 return NULL;
0fcfd160
LT
1281}
1282
40469ee9 1283void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1284 const char *required_type,
40469ee9
JH
1285 unsigned long *size,
1286 unsigned char *actual_sha1_return)
f4913f91
JH
1287{
1288 char type[20];
1289 void *buffer;
1290 unsigned long isize;
40469ee9 1291 unsigned char actual_sha1[20];
f4913f91 1292
e702496e 1293 hashcpy(actual_sha1, sha1);
40469ee9
JH
1294 while (1) {
1295 int ref_length = -1;
1296 const char *ref_type = NULL;
f4913f91 1297
40469ee9
JH
1298 buffer = read_sha1_file(actual_sha1, type, &isize);
1299 if (!buffer)
1300 return NULL;
1301 if (!strcmp(type, required_type)) {
1302 *size = isize;
1303 if (actual_sha1_return)
e702496e 1304 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1305 return buffer;
1306 }
1307 /* Handle references */
8e440259 1308 else if (!strcmp(type, commit_type))
40469ee9 1309 ref_type = "tree ";
8e440259 1310 else if (!strcmp(type, tag_type))
40469ee9
JH
1311 ref_type = "object ";
1312 else {
1313 free(buffer);
1314 return NULL;
1315 }
1316 ref_length = strlen(ref_type);
f4913f91 1317
40469ee9 1318 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1319 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1320 free(buffer);
1321 return NULL;
1322 }
1cf58e72 1323 free(buffer);
40469ee9
JH
1324 /* Now we have the ID of the referred-to object in
1325 * actual_sha1. Check again. */
f4913f91 1326 }
f4913f91
JH
1327}
1328
7672db20
BL
1329char *write_sha1_file_prepare(void *buf,
1330 unsigned long len,
1331 const char *type,
1332 unsigned char *sha1,
1333 unsigned char *hdr,
1334 int *hdrlen)
d410c0f5
JH
1335{
1336 SHA_CTX c;
1337
1338 /* Generate the header */
1339 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1340
1341 /* Sha1.. */
1342 SHA1_Init(&c);
1343 SHA1_Update(&c, hdr, *hdrlen);
1344 SHA1_Update(&c, buf, len);
1345 SHA1_Final(sha1, &c);
1346
1347 return sha1_file_name(sha1);
1348}
1349
230f1322
LT
1350/*
1351 * Link the tempfile to the final place, possibly creating the
1352 * last directory level as you do so.
1353 *
1354 * Returns the errno on failure, 0 on success.
1355 */
839837b9 1356static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1357{
1358 int ret;
756aaf4a 1359 char *dir;
230f1322
LT
1360
1361 if (!link(tmpfile, filename))
1362 return 0;
1363
1364 /*
756aaf4a 1365 * Try to mkdir the last path component if that failed.
230f1322
LT
1366 *
1367 * Re-try the "link()" regardless of whether the mkdir
1368 * succeeds, since a race might mean that somebody
1369 * else succeeded.
1370 */
1371 ret = errno;
756aaf4a
SP
1372 dir = strrchr(filename, '/');
1373 if (dir) {
1374 *dir = 0;
1375 mkdir(filename, 0777);
1376 if (adjust_shared_perm(filename))
1377 return -2;
1378 *dir = '/';
1379 if (!link(tmpfile, filename))
1380 return 0;
1381 ret = errno;
230f1322
LT
1382 }
1383 return ret;
1384}
1385
1386/*
1387 * Move the just written object into its final resting place
1388 */
839837b9 1389int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1390{
1391 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
1392
1393 /*
1394 * Coda hack - coda doesn't like cross-directory links,
1395 * so we fall back to a rename, which will mean that it
1396 * won't be able to check collisions, but that's not a
1397 * big deal.
1398 *
1399 * The same holds for FAT formatted media.
1400 *
1401 * When this succeeds, we just return 0. We have nothing
1402 * left to unlink.
1403 */
1404 if (ret && ret != EEXIST) {
1405 if (!rename(tmpfile, filename))
230f1322 1406 return 0;
9e48b389 1407 ret = errno;
230f1322
LT
1408 }
1409 unlink(tmpfile);
1410 if (ret) {
1411 if (ret != EEXIST) {
7246ed43 1412 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
1413 return -1;
1414 }
1415 /* FIXME!!! Collision check here ? */
1416 }
1417
1418 return 0;
1419}
1420
4d548150
LT
1421static int write_buffer(int fd, const void *buf, size_t len)
1422{
1423 while (len) {
1424 ssize_t size;
1425
1426 size = write(fd, buf, len);
1427 if (!size)
1428 return error("file write: disk full");
1429 if (size < 0) {
1430 if (errno == EINTR || errno == EAGAIN)
1431 continue;
1432 return error("file write error (%s)", strerror(errno));
1433 }
1434 len -= size;
1d7f171c 1435 buf = (char *) buf + size;
4d548150
LT
1436 }
1437 return 0;
1438}
1439
93821bd9
LT
1440static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1441{
1442 int hdr_len;
1443 unsigned char c;
1444
1445 c = (type << 4) | (len & 15);
1446 len >>= 4;
1447 hdr_len = 1;
1448 while (len) {
1449 *hdr++ = c | 0x80;
1450 hdr_len++;
1451 c = (len & 0x7f);
1452 len >>= 7;
1453 }
1454 *hdr = c;
1455 return hdr_len;
1456}
1457
1458static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1459{
1460 int obj_type, hdr;
1461
1462 if (use_legacy_headers) {
1463 while (deflate(stream, 0) == Z_OK)
1464 /* nothing */;
1465 return;
1466 }
1467 if (!strcmp(type, blob_type))
1468 obj_type = OBJ_BLOB;
1469 else if (!strcmp(type, tree_type))
1470 obj_type = OBJ_TREE;
1471 else if (!strcmp(type, commit_type))
1472 obj_type = OBJ_COMMIT;
1473 else if (!strcmp(type, tag_type))
1474 obj_type = OBJ_TAG;
1475 else
1476 die("trying to generate bogus object of type '%s'", type);
1477 hdr = write_binary_header(stream->next_out, obj_type, len);
1478 stream->total_out = hdr;
1479 stream->next_out += hdr;
1480 stream->avail_out -= hdr;
1481}
1482
bf0f910d 1483int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1484{
1485 int size;
bf0f910d 1486 unsigned char *compressed;
0fcfd160
LT
1487 z_stream stream;
1488 unsigned char sha1[20];
706bc531 1489 char *filename;
aac17941 1490 static char tmpfile[PATH_MAX];
bf0f910d 1491 unsigned char hdr[50];
230f1322 1492 int fd, hdrlen;
a44c9a5e 1493
d410c0f5
JH
1494 /* Normally if we have it in the pack then we do not bother writing
1495 * it out into .git/objects/??/?{38} file.
1496 */
1497 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
706bc531 1498 if (returnsha1)
e702496e 1499 hashcpy(returnsha1, sha1);
d410c0f5
JH
1500 if (has_sha1_file(sha1))
1501 return 0;
aac17941
LT
1502 fd = open(filename, O_RDONLY);
1503 if (fd >= 0) {
706bc531 1504 /*
aac17941
LT
1505 * FIXME!!! We might do collision checking here, but we'd
1506 * need to uncompress the old file and check it. Later.
706bc531 1507 */
aac17941 1508 close(fd);
706bc531
LT
1509 return 0;
1510 }
1511
aac17941 1512 if (errno != ENOENT) {
7246ed43 1513 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
1514 return -1;
1515 }
1516
1517 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1518
aac17941
LT
1519 fd = mkstemp(tmpfile);
1520 if (fd < 0) {
7246ed43 1521 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
1522 return -1;
1523 }
1524
0fcfd160
LT
1525 /* Set it up */
1526 memset(&stream, 0, sizeof(stream));
12f6c308 1527 deflateInit(&stream, zlib_compression_level);
93821bd9 1528 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 1529 compressed = xmalloc(size);
0fcfd160
LT
1530
1531 /* Compress it */
0fcfd160
LT
1532 stream.next_out = compressed;
1533 stream.avail_out = size;
a44c9a5e
LT
1534
1535 /* First header.. */
1536 stream.next_in = hdr;
1537 stream.avail_in = hdrlen;
93821bd9 1538 setup_object_header(&stream, type, len);
a44c9a5e
LT
1539
1540 /* Then the data itself.. */
1541 stream.next_in = buf;
1542 stream.avail_in = len;
0fcfd160
LT
1543 while (deflate(&stream, Z_FINISH) == Z_OK)
1544 /* nothing */;
1545 deflateEnd(&stream);
1546 size = stream.total_out;
1547
4d548150
LT
1548 if (write_buffer(fd, compressed, size) < 0)
1549 die("unable to write sha1 file");
aac17941 1550 fchmod(fd, 0444);
706bc531 1551 close(fd);
383f85b7 1552 free(compressed);
0fcfd160 1553
230f1322 1554 return move_temp_to_file(tmpfile, filename);
0fcfd160 1555}
8237b185 1556
4d548150
LT
1557/*
1558 * We need to unpack and recompress the object for writing
1559 * it out to a different file.
1560 */
1561static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 1562{
4d548150 1563 size_t size;
a5eda52b 1564 z_stream stream;
4d548150
LT
1565 unsigned char *unpacked;
1566 unsigned long len;
1567 char type[20];
1568 char hdr[50];
1569 int hdrlen;
1570 void *buf;
bfc66daf 1571
a9486b02 1572 /* need to unpack and recompress it by itself */
4d548150 1573 unpacked = read_packed_sha1(sha1, type, &len);
a5eda52b 1574
4d548150 1575 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
a5eda52b 1576
4d548150
LT
1577 /* Set it up */
1578 memset(&stream, 0, sizeof(stream));
12f6c308 1579 deflateInit(&stream, zlib_compression_level);
4d548150
LT
1580 size = deflateBound(&stream, len + hdrlen);
1581 buf = xmalloc(size);
a5eda52b 1582
4d548150
LT
1583 /* Compress it */
1584 stream.next_out = buf;
1585 stream.avail_out = size;
a5eda52b 1586
4d548150
LT
1587 /* First header.. */
1588 stream.next_in = (void *)hdr;
1589 stream.avail_in = hdrlen;
1590 while (deflate(&stream, 0) == Z_OK)
1591 /* nothing */;
bfc66daf 1592
4d548150
LT
1593 /* Then the data itself.. */
1594 stream.next_in = unpacked;
1595 stream.avail_in = len;
1596 while (deflate(&stream, Z_FINISH) == Z_OK)
1597 /* nothing */;
1598 deflateEnd(&stream);
1599 free(unpacked);
bfc66daf 1600
4d548150
LT
1601 *objsize = stream.total_out;
1602 return buf;
1603}
1604
1605int write_sha1_to_fd(int fd, const unsigned char *sha1)
1606{
1607 int retval;
1608 unsigned long objsize;
bb6b8e4f 1609 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
1610
1611 if (buf) {
1612 retval = write_buffer(fd, buf, objsize);
1613 munmap(buf, objsize);
1614 return retval;
1615 }
1616
1617 buf = repack_object(sha1, &objsize);
1618 retval = write_buffer(fd, buf, objsize);
1619 free(buf);
1620 return retval;
a5eda52b
DB
1621}
1622
70b9829e
DB
1623int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1624 size_t bufsize, size_t *bufposn)
8237b185 1625{
230f1322 1626 char tmpfile[PATH_MAX];
8237b185
DB
1627 int local;
1628 z_stream stream;
1629 unsigned char real_sha1[20];
bf0f910d 1630 unsigned char discard[4096];
8237b185
DB
1631 int ret;
1632 SHA_CTX c;
1633
230f1322 1634 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
8237b185 1635
230f1322 1636 local = mkstemp(tmpfile);
8237b185 1637 if (local < 0)
bd2afde8
JH
1638 return error("Couldn't open %s for %s",
1639 tmpfile, sha1_to_hex(sha1));
8237b185
DB
1640
1641 memset(&stream, 0, sizeof(stream));
1642
1643 inflateInit(&stream);
1644
1645 SHA1_Init(&c);
1646
1647 do {
1648 ssize_t size;
70b9829e
DB
1649 if (*bufposn) {
1650 stream.avail_in = *bufposn;
96ad15ae 1651 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
1652 do {
1653 stream.next_out = discard;
1654 stream.avail_out = sizeof(discard);
1655 ret = inflate(&stream, Z_SYNC_FLUSH);
1656 SHA1_Update(&c, discard, sizeof(discard) -
1657 stream.avail_out);
1658 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
1659 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1660 die("unable to write sha1 file");
70b9829e
DB
1661 memmove(buffer, buffer + *bufposn - stream.avail_in,
1662 stream.avail_in);
1663 *bufposn = stream.avail_in;
1664 if (ret != Z_OK)
1665 break;
1666 }
1667 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
1668 if (size <= 0) {
1669 close(local);
230f1322 1670 unlink(tmpfile);
8237b185
DB
1671 if (!size)
1672 return error("Connection closed?");
1673 perror("Reading from connection");
1674 return -1;
1675 }
70b9829e
DB
1676 *bufposn += size;
1677 } while (1);
8237b185
DB
1678 inflateEnd(&stream);
1679
1680 close(local);
1681 SHA1_Final(real_sha1, &c);
1682 if (ret != Z_STREAM_END) {
230f1322 1683 unlink(tmpfile);
8237b185
DB
1684 return error("File %s corrupted", sha1_to_hex(sha1));
1685 }
a89fccd2 1686 if (hashcmp(sha1, real_sha1)) {
230f1322 1687 unlink(tmpfile);
bd2afde8 1688 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 1689 }
230f1322
LT
1690
1691 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
1692}
1693
bf592c50
DB
1694int has_pack_index(const unsigned char *sha1)
1695{
1696 struct stat st;
1697 if (stat(sha1_pack_index_name(sha1), &st))
1698 return 0;
1699 return 1;
1700}
1701
1702int has_pack_file(const unsigned char *sha1)
1703{
1704 struct stat st;
1705 if (stat(sha1_pack_name(sha1), &st))
1706 return 0;
1707 return 1;
1708}
1709
dade09c2
LT
1710int has_sha1_pack(const unsigned char *sha1)
1711{
1712 struct pack_entry e;
1713 return find_pack_entry(sha1, &e);
1714}
1715
8237b185
DB
1716int has_sha1_file(const unsigned char *sha1)
1717{
8237b185 1718 struct stat st;
1f688557
JH
1719 struct pack_entry e;
1720
ab90ea5d 1721 if (find_pack_entry(sha1, &e))
1f688557 1722 return 1;
ab90ea5d 1723 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 1724}
74400e71 1725
e7332f96
BE
1726/*
1727 * reads from fd as long as possible into a supplied buffer of size bytes.
82e5a82f 1728 * If necessary the buffer's size is increased using realloc()
e7332f96
BE
1729 *
1730 * returns 0 if anything went fine and -1 otherwise
1731 *
1732 * NOTE: both buf and size may change, but even when -1 is returned
1733 * you still have to free() it yourself.
1734 */
1735int read_pipe(int fd, char** return_buf, unsigned long* return_size)
024510c8 1736{
e7332f96
BE
1737 char* buf = *return_buf;
1738 unsigned long size = *return_size;
1739 int iret;
024510c8 1740 unsigned long off = 0;
e7332f96 1741
024510c8 1742 do {
e7332f96 1743 iret = xread(fd, buf + off, size - off);
024510c8
DB
1744 if (iret > 0) {
1745 off += iret;
1746 if (off == size) {
1747 size *= 2;
83572c1a 1748 buf = xrealloc(buf, size);
024510c8
DB
1749 }
1750 }
1751 } while (iret > 0);
e7332f96
BE
1752
1753 *return_buf = buf;
1754 *return_size = off;
1755
1756 if (iret < 0)
1757 return -1;
1758 return 0;
1759}
1760
1761int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1762{
1763 unsigned long size = 4096;
2d7320d0 1764 char *buf = xmalloc(size);
e7332f96
BE
1765 int ret;
1766 unsigned char hdr[50];
1767 int hdrlen;
1768
1769 if (read_pipe(fd, &buf, &size)) {
024510c8
DB
1770 free(buf);
1771 return -1;
1772 }
e7332f96 1773
024510c8 1774 if (!type)
8e440259 1775 type = blob_type;
024510c8 1776 if (write_object)
e7332f96 1777 ret = write_sha1_file(buf, size, type, sha1);
024510c8 1778 else {
e7332f96 1779 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
024510c8
DB
1780 ret = 0;
1781 }
1782 free(buf);
1783 return ret;
1784}
1785
7672db20 1786int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
74400e71 1787{
74400e71 1788 unsigned long size = st->st_size;
aac17941
LT
1789 void *buf;
1790 int ret;
7672db20
BL
1791 unsigned char hdr[50];
1792 int hdrlen;
74400e71 1793
aac17941 1794 buf = "";
74400e71 1795 if (size)
aac17941 1796 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1797 close(fd);
e35f9824 1798 if (buf == MAP_FAILED)
74400e71
JH
1799 return -1;
1800
7672db20 1801 if (!type)
8e440259 1802 type = blob_type;
7672db20
BL
1803 if (write_object)
1804 ret = write_sha1_file(buf, size, type, sha1);
1805 else {
1806 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1807 ret = 0;
1808 }
aac17941
LT
1809 if (size)
1810 munmap(buf, size);
1811 return ret;
74400e71 1812}
ec1fcc16
JH
1813
1814int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1815{
1816 int fd;
1817 char *target;
1818
1819 switch (st->st_mode & S_IFMT) {
1820 case S_IFREG:
1821 fd = open(path, O_RDONLY);
1822 if (fd < 0)
1823 return error("open(\"%s\"): %s", path,
1824 strerror(errno));
1825 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1826 return error("%s: failed to insert into database",
1827 path);
1828 break;
1829 case S_IFLNK:
1830 target = xmalloc(st->st_size+1);
1831 if (readlink(path, target, st->st_size+1) != st->st_size) {
1832 char *errstr = strerror(errno);
1833 free(target);
1834 return error("readlink(\"%s\"): %s", path,
1835 errstr);
1836 }
1837 if (!write_object) {
1838 unsigned char hdr[50];
1839 int hdrlen;
8e440259 1840 write_sha1_file_prepare(target, st->st_size, blob_type,
ec1fcc16 1841 sha1, hdr, &hdrlen);
8e440259 1842 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
ec1fcc16
JH
1843 return error("%s: failed to insert into database",
1844 path);
1845 free(target);
1846 break;
1847 default:
1848 return error("%s: unsupported file type", path);
1849 }
1850 return 0;
1851}