Merge branch 'gl/cleanup'
[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;
a733cb60
LT
920 unsigned char *pack, c;
921 unsigned long size;
922
923 if (offset >= p->pack_size)
924 die("object offset outside of pack file");
925
1d7f171c 926 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
927 c = *pack++;
928 offset++;
929 *type = (c >> 4) & 7;
930 size = c & 15;
01247d87 931 shift = 4;
a733cb60
LT
932 while (c & 0x80) {
933 if (offset >= p->pack_size)
934 die("object offset outside of pack file");
935 c = *pack++;
936 offset++;
01247d87
LT
937 size += (c & 0x7f) << shift;
938 shift += 7;
a733cb60
LT
939 }
940 *sizep = size;
941 return offset;
942}
943
a49dd05f
JH
944int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
945 unsigned char *base, unsigned long *sizep,
946 enum object_type *kindp)
947{
948 unsigned long ptr;
949 int status = -1;
950
951 use_packed_git(p);
952 ptr = offset;
953 ptr = unpack_object_header(p, ptr, kindp, sizep);
954 if (*kindp != OBJ_DELTA)
955 goto done;
e702496e 956 hashcpy(base, (unsigned char *) p->pack_base + ptr);
a49dd05f
JH
957 status = 0;
958 done:
959 unuse_packed_git(p);
960 return status;
961}
962
ad8c80a5
JH
963void packed_object_info_detail(struct pack_entry *e,
964 char *type,
965 unsigned long *size,
966 unsigned long *store_size,
f8f135c9 967 unsigned int *delta_chain_length,
ad8c80a5
JH
968 unsigned char *base_sha1)
969{
970 struct packed_git *p = e->p;
2855d580 971 unsigned long offset;
ad8c80a5
JH
972 unsigned char *pack;
973 enum object_type kind;
974
975 offset = unpack_object_header(p, e->offset, &kind, size);
1d7f171c 976 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
977 if (kind != OBJ_DELTA)
978 *delta_chain_length = 0;
979 else {
f8f135c9 980 unsigned int chain_length = 0;
2855d580
JH
981 if (p->pack_size <= offset + 20)
982 die("pack file %s records an incomplete delta base",
983 p->pack_name);
e702496e 984 hashcpy(base_sha1, pack);
ad8c80a5
JH
985 do {
986 struct pack_entry base_ent;
987 unsigned long junk;
988
989 find_pack_entry_one(pack, &base_ent, p);
990 offset = unpack_object_header(p, base_ent.offset,
991 &kind, &junk);
1d7f171c 992 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
993 chain_length++;
994 } while (kind == OBJ_DELTA);
995 *delta_chain_length = chain_length;
996 }
997 switch (kind) {
998 case OBJ_COMMIT:
8e440259 999 strcpy(type, commit_type);
ad8c80a5
JH
1000 break;
1001 case OBJ_TREE:
8e440259 1002 strcpy(type, tree_type);
ad8c80a5
JH
1003 break;
1004 case OBJ_BLOB:
8e440259 1005 strcpy(type, blob_type);
ad8c80a5
JH
1006 break;
1007 case OBJ_TAG:
8e440259 1008 strcpy(type, tag_type);
ad8c80a5
JH
1009 break;
1010 default:
264b16b6
JH
1011 die("corrupted pack file %s containing object of kind %d",
1012 p->pack_name, kind);
ad8c80a5
JH
1013 }
1014 *store_size = 0; /* notyet */
1015}
1016
1f688557
JH
1017static int packed_object_info(struct pack_entry *entry,
1018 char *type, unsigned long *sizep)
1019{
1020 struct packed_git *p = entry->p;
1021 unsigned long offset, size, left;
1022 unsigned char *pack;
a733cb60 1023 enum object_type kind;
f9253394 1024 int retval;
5db47c2b
JH
1025
1026 if (use_packed_git(p))
1027 die("cannot map packed file");
1028
a733cb60 1029 offset = unpack_object_header(p, entry->offset, &kind, &size);
1d7f171c 1030 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
1031 left = p->pack_size - offset;
1032
1033 switch (kind) {
1034 case OBJ_DELTA:
f3bf9224 1035 retval = packed_delta_info(pack, size, left, type, sizep, p);
f9253394
JH
1036 unuse_packed_git(p);
1037 return retval;
a733cb60 1038 case OBJ_COMMIT:
8e440259 1039 strcpy(type, commit_type);
1f688557 1040 break;
a733cb60 1041 case OBJ_TREE:
8e440259 1042 strcpy(type, tree_type);
1f688557 1043 break;
a733cb60 1044 case OBJ_BLOB:
8e440259 1045 strcpy(type, blob_type);
1f688557 1046 break;
a733cb60 1047 case OBJ_TAG:
8e440259 1048 strcpy(type, tag_type);
a69d0943 1049 break;
1f688557 1050 default:
264b16b6
JH
1051 die("corrupted pack file %s containing object of kind %d",
1052 p->pack_name, kind);
1f688557 1053 }
c62266f3
JH
1054 if (sizep)
1055 *sizep = size;
f9253394 1056 unuse_packed_git(p);
1f688557
JH
1057 return 0;
1058}
1059
1f688557
JH
1060static void *unpack_delta_entry(unsigned char *base_sha1,
1061 unsigned long delta_size,
1062 unsigned long left,
1063 char *type,
f3bf9224
JH
1064 unsigned long *sizep,
1065 struct packed_git *p)
1f688557 1066{
f3bf9224 1067 struct pack_entry base_ent;
1f688557
JH
1068 void *data, *delta_data, *result, *base;
1069 unsigned long data_size, result_size, base_size;
1070 z_stream stream;
1071 int st;
1072
1073 if (left < 20)
1074 die("truncated pack file");
67686d95
JH
1075
1076 /* The base entry _must_ be in the same pack */
1077 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1078 die("failed to find delta-pack base object %s",
1079 sha1_to_hex(base_sha1));
1080 base = unpack_entry_gently(&base_ent, type, &base_size);
1081 if (!base)
1082 die("failed to read delta-pack base object %s",
1083 sha1_to_hex(base_sha1));
1084
1f688557
JH
1085 data = base_sha1 + 20;
1086 data_size = left - 20;
1087 delta_data = xmalloc(delta_size);
1088
1089 memset(&stream, 0, sizeof(stream));
1090
1091 stream.next_in = data;
1092 stream.avail_in = data_size;
1093 stream.next_out = delta_data;
1094 stream.avail_out = delta_size;
1095
1096 inflateInit(&stream);
1097 st = inflate(&stream, Z_FINISH);
1098 inflateEnd(&stream);
1099 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
1100 die("delta data unpack failed");
1101
1f688557
JH
1102 result = patch_delta(base, base_size,
1103 delta_data, delta_size,
1104 &result_size);
1105 if (!result)
1106 die("failed to apply delta");
1107 free(delta_data);
1108 free(base);
1109 *sizep = result_size;
1110 return result;
1111}
1112
1113static void *unpack_non_delta_entry(unsigned char *data,
1114 unsigned long size,
1115 unsigned long left)
1116{
1117 int st;
1118 z_stream stream;
4d235c80 1119 unsigned char *buffer;
1f688557
JH
1120
1121 buffer = xmalloc(size + 1);
1122 buffer[size] = 0;
1123 memset(&stream, 0, sizeof(stream));
1124 stream.next_in = data;
1125 stream.avail_in = left;
1126 stream.next_out = buffer;
1127 stream.avail_out = size;
1128
1129 inflateInit(&stream);
1130 st = inflate(&stream, Z_FINISH);
1131 inflateEnd(&stream);
1132 if ((st != Z_STREAM_END) || stream.total_out != size) {
1133 free(buffer);
1134 return NULL;
1135 }
1136
1137 return buffer;
1138}
1139
1140static void *unpack_entry(struct pack_entry *entry,
1141 char *type, unsigned long *sizep)
1142{
1143 struct packed_git *p = entry->p;
f9253394 1144 void *retval;
1f688557
JH
1145
1146 if (use_packed_git(p))
1147 die("cannot map packed file");
f3bf9224
JH
1148 retval = unpack_entry_gently(entry, type, sizep);
1149 unuse_packed_git(p);
1150 if (!retval)
264b16b6 1151 die("corrupted pack file %s", p->pack_name);
f3bf9224
JH
1152 return retval;
1153}
1154
1155/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1156void *unpack_entry_gently(struct pack_entry *entry,
1157 char *type, unsigned long *sizep)
1158{
1159 struct packed_git *p = entry->p;
1160 unsigned long offset, size, left;
1161 unsigned char *pack;
1162 enum object_type kind;
1163 void *retval;
1f688557 1164
a733cb60 1165 offset = unpack_object_header(p, entry->offset, &kind, &size);
1d7f171c 1166 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
1167 left = p->pack_size - offset;
1168 switch (kind) {
1169 case OBJ_DELTA:
f3bf9224 1170 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
f9253394 1171 return retval;
a733cb60 1172 case OBJ_COMMIT:
8e440259 1173 strcpy(type, commit_type);
1f688557 1174 break;
a733cb60 1175 case OBJ_TREE:
8e440259 1176 strcpy(type, tree_type);
1f688557 1177 break;
a733cb60 1178 case OBJ_BLOB:
8e440259 1179 strcpy(type, blob_type);
1f688557 1180 break;
a733cb60 1181 case OBJ_TAG:
8e440259 1182 strcpy(type, tag_type);
a69d0943 1183 break;
1f688557 1184 default:
f3bf9224 1185 return NULL;
1f688557
JH
1186 }
1187 *sizep = size;
f9253394 1188 retval = unpack_non_delta_entry(pack, size, left);
f9253394 1189 return retval;
1f688557
JH
1190}
1191
9a217f2a
JH
1192int num_packed_objects(const struct packed_git *p)
1193{
f9253394 1194 /* See check_packed_git_idx() */
9a217f2a
JH
1195 return (p->index_size - 20 - 20 - 4*256) / 24;
1196}
1197
1198int nth_packed_object_sha1(const struct packed_git *p, int n,
1199 unsigned char* sha1)
1200{
1201 void *index = p->index_base + 256;
1202 if (n < 0 || num_packed_objects(p) <= n)
1203 return -1;
e702496e 1204 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
9a217f2a
JH
1205 return 0;
1206}
1207
f3bf9224
JH
1208int find_pack_entry_one(const unsigned char *sha1,
1209 struct pack_entry *e, struct packed_git *p)
1f688557 1210{
4d235c80 1211 unsigned int *level1_ofs = p->index_base;
1f688557
JH
1212 int hi = ntohl(level1_ofs[*sha1]);
1213 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1214 void *index = p->index_base + 256;
1215
1216 do {
1217 int mi = (lo + hi) / 2;
a89fccd2 1218 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
1f688557 1219 if (!cmp) {
1d7f171c 1220 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
e702496e 1221 hashcpy(e->sha1, sha1);
1f688557
JH
1222 e->p = p;
1223 return 1;
1224 }
1225 if (cmp > 0)
1226 hi = mi;
1227 else
1228 lo = mi+1;
1229 } while (lo < hi);
1230 return 0;
1231}
1232
1233static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1234{
1235 struct packed_git *p;
1236 prepare_packed_git();
1237
1238 for (p = packed_git; p; p = p->next) {
f3bf9224 1239 if (find_pack_entry_one(sha1, e, p))
1f688557
JH
1240 return 1;
1241 }
1242 return 0;
1243}
1244
bf592c50
DB
1245struct packed_git *find_sha1_pack(const unsigned char *sha1,
1246 struct packed_git *packs)
1247{
1248 struct packed_git *p;
1249 struct pack_entry e;
1250
1251 for (p = packs; p; p = p->next) {
1252 if (find_pack_entry_one(sha1, &e, p))
1253 return p;
1254 }
1255 return NULL;
1256
1257}
1258
36e4d74a 1259int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1260{
36e4d74a 1261 int status;
65c2e0c3
JH
1262 unsigned long mapsize, size;
1263 void *map;
1264 z_stream stream;
36e4d74a 1265 char hdr[128];
65c2e0c3 1266
bb6b8e4f 1267 map = map_sha1_file(sha1, &mapsize);
1f688557
JH
1268 if (!map) {
1269 struct pack_entry e;
1270
637cdd9d
JK
1271 if (find_pack_entry(sha1, &e))
1272 return packed_object_info(&e, type, sizep);
1273 reprepare_packed_git();
1274 if (find_pack_entry(sha1, &e))
1275 return packed_object_info(&e, type, sizep);
1276 return error("unable to find %s", sha1_to_hex(sha1));
1f688557 1277 }
36e4d74a
JH
1278 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1279 status = error("unable to unpack %s header",
1280 sha1_to_hex(sha1));
1281 if (parse_sha1_header(hdr, type, &size) < 0)
1282 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1283 else {
65c2e0c3 1284 status = 0;
c62266f3
JH
1285 if (sizep)
1286 *sizep = size;
65c2e0c3 1287 }
65c2e0c3
JH
1288 inflateEnd(&stream);
1289 munmap(map, mapsize);
1290 return status;
1291}
1292
1f688557
JH
1293static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1294{
1295 struct pack_entry e;
1296
1297 if (!find_pack_entry(sha1, &e)) {
1298 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1299 return NULL;
1300 }
1301 return unpack_entry(&e, type, size);
1302}
1303
0fcfd160
LT
1304void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1305{
1306 unsigned long mapsize;
1307 void *map, *buf;
ab90ea5d 1308 struct pack_entry e;
0fcfd160 1309
ab90ea5d
JH
1310 if (find_pack_entry(sha1, &e))
1311 return read_packed_sha1(sha1, type, size);
bb6b8e4f 1312 map = map_sha1_file(sha1, &mapsize);
0fcfd160
LT
1313 if (map) {
1314 buf = unpack_sha1_file(map, mapsize, type, size);
1315 munmap(map, mapsize);
1316 return buf;
1317 }
637cdd9d
JK
1318 reprepare_packed_git();
1319 if (find_pack_entry(sha1, &e))
1320 return read_packed_sha1(sha1, type, size);
ab90ea5d 1321 return NULL;
0fcfd160
LT
1322}
1323
40469ee9 1324void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1325 const char *required_type,
40469ee9
JH
1326 unsigned long *size,
1327 unsigned char *actual_sha1_return)
f4913f91
JH
1328{
1329 char type[20];
1330 void *buffer;
1331 unsigned long isize;
40469ee9 1332 unsigned char actual_sha1[20];
f4913f91 1333
e702496e 1334 hashcpy(actual_sha1, sha1);
40469ee9
JH
1335 while (1) {
1336 int ref_length = -1;
1337 const char *ref_type = NULL;
f4913f91 1338
40469ee9
JH
1339 buffer = read_sha1_file(actual_sha1, type, &isize);
1340 if (!buffer)
1341 return NULL;
1342 if (!strcmp(type, required_type)) {
1343 *size = isize;
1344 if (actual_sha1_return)
e702496e 1345 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1346 return buffer;
1347 }
1348 /* Handle references */
8e440259 1349 else if (!strcmp(type, commit_type))
40469ee9 1350 ref_type = "tree ";
8e440259 1351 else if (!strcmp(type, tag_type))
40469ee9
JH
1352 ref_type = "object ";
1353 else {
1354 free(buffer);
1355 return NULL;
1356 }
1357 ref_length = strlen(ref_type);
f4913f91 1358
40469ee9 1359 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1360 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1361 free(buffer);
1362 return NULL;
1363 }
1cf58e72 1364 free(buffer);
40469ee9
JH
1365 /* Now we have the ID of the referred-to object in
1366 * actual_sha1. Check again. */
f4913f91 1367 }
f4913f91
JH
1368}
1369
7672db20
BL
1370char *write_sha1_file_prepare(void *buf,
1371 unsigned long len,
1372 const char *type,
1373 unsigned char *sha1,
1374 unsigned char *hdr,
1375 int *hdrlen)
d410c0f5
JH
1376{
1377 SHA_CTX c;
1378
1379 /* Generate the header */
1380 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1381
1382 /* Sha1.. */
1383 SHA1_Init(&c);
1384 SHA1_Update(&c, hdr, *hdrlen);
1385 SHA1_Update(&c, buf, len);
1386 SHA1_Final(sha1, &c);
1387
1388 return sha1_file_name(sha1);
1389}
1390
230f1322
LT
1391/*
1392 * Link the tempfile to the final place, possibly creating the
1393 * last directory level as you do so.
1394 *
1395 * Returns the errno on failure, 0 on success.
1396 */
1397static int link_temp_to_file(const char *tmpfile, char *filename)
1398{
1399 int ret;
756aaf4a 1400 char *dir;
230f1322
LT
1401
1402 if (!link(tmpfile, filename))
1403 return 0;
1404
1405 /*
756aaf4a 1406 * Try to mkdir the last path component if that failed.
230f1322
LT
1407 *
1408 * Re-try the "link()" regardless of whether the mkdir
1409 * succeeds, since a race might mean that somebody
1410 * else succeeded.
1411 */
1412 ret = errno;
756aaf4a
SP
1413 dir = strrchr(filename, '/');
1414 if (dir) {
1415 *dir = 0;
1416 mkdir(filename, 0777);
1417 if (adjust_shared_perm(filename))
1418 return -2;
1419 *dir = '/';
1420 if (!link(tmpfile, filename))
1421 return 0;
1422 ret = errno;
230f1322
LT
1423 }
1424 return ret;
1425}
1426
1427/*
1428 * Move the just written object into its final resting place
1429 */
b721e01f 1430int move_temp_to_file(const char *tmpfile, char *filename)
230f1322
LT
1431{
1432 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
1433
1434 /*
1435 * Coda hack - coda doesn't like cross-directory links,
1436 * so we fall back to a rename, which will mean that it
1437 * won't be able to check collisions, but that's not a
1438 * big deal.
1439 *
1440 * The same holds for FAT formatted media.
1441 *
1442 * When this succeeds, we just return 0. We have nothing
1443 * left to unlink.
1444 */
1445 if (ret && ret != EEXIST) {
1446 if (!rename(tmpfile, filename))
230f1322 1447 return 0;
9e48b389 1448 ret = errno;
230f1322
LT
1449 }
1450 unlink(tmpfile);
1451 if (ret) {
1452 if (ret != EEXIST) {
7246ed43 1453 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
1454 return -1;
1455 }
1456 /* FIXME!!! Collision check here ? */
1457 }
1458
1459 return 0;
1460}
1461
4d548150
LT
1462static int write_buffer(int fd, const void *buf, size_t len)
1463{
1464 while (len) {
1465 ssize_t size;
1466
1467 size = write(fd, buf, len);
1468 if (!size)
1469 return error("file write: disk full");
1470 if (size < 0) {
1471 if (errno == EINTR || errno == EAGAIN)
1472 continue;
1473 return error("file write error (%s)", strerror(errno));
1474 }
1475 len -= size;
1d7f171c 1476 buf = (char *) buf + size;
4d548150
LT
1477 }
1478 return 0;
1479}
1480
93821bd9
LT
1481static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1482{
1483 int hdr_len;
1484 unsigned char c;
1485
1486 c = (type << 4) | (len & 15);
1487 len >>= 4;
1488 hdr_len = 1;
1489 while (len) {
1490 *hdr++ = c | 0x80;
1491 hdr_len++;
1492 c = (len & 0x7f);
1493 len >>= 7;
1494 }
1495 *hdr = c;
1496 return hdr_len;
1497}
1498
1499static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1500{
1501 int obj_type, hdr;
1502
1503 if (use_legacy_headers) {
1504 while (deflate(stream, 0) == Z_OK)
1505 /* nothing */;
1506 return;
1507 }
1508 if (!strcmp(type, blob_type))
1509 obj_type = OBJ_BLOB;
1510 else if (!strcmp(type, tree_type))
1511 obj_type = OBJ_TREE;
1512 else if (!strcmp(type, commit_type))
1513 obj_type = OBJ_COMMIT;
1514 else if (!strcmp(type, tag_type))
1515 obj_type = OBJ_TAG;
1516 else
1517 die("trying to generate bogus object of type '%s'", type);
1518 hdr = write_binary_header(stream->next_out, obj_type, len);
1519 stream->total_out = hdr;
1520 stream->next_out += hdr;
1521 stream->avail_out -= hdr;
1522}
1523
bf0f910d 1524int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1525{
1526 int size;
bf0f910d 1527 unsigned char *compressed;
0fcfd160
LT
1528 z_stream stream;
1529 unsigned char sha1[20];
706bc531 1530 char *filename;
aac17941 1531 static char tmpfile[PATH_MAX];
bf0f910d 1532 unsigned char hdr[50];
230f1322 1533 int fd, hdrlen;
a44c9a5e 1534
d410c0f5
JH
1535 /* Normally if we have it in the pack then we do not bother writing
1536 * it out into .git/objects/??/?{38} file.
1537 */
1538 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
706bc531 1539 if (returnsha1)
e702496e 1540 hashcpy(returnsha1, sha1);
d410c0f5
JH
1541 if (has_sha1_file(sha1))
1542 return 0;
aac17941
LT
1543 fd = open(filename, O_RDONLY);
1544 if (fd >= 0) {
706bc531 1545 /*
aac17941
LT
1546 * FIXME!!! We might do collision checking here, but we'd
1547 * need to uncompress the old file and check it. Later.
706bc531 1548 */
aac17941 1549 close(fd);
706bc531
LT
1550 return 0;
1551 }
1552
aac17941 1553 if (errno != ENOENT) {
7246ed43 1554 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
1555 return -1;
1556 }
1557
1558 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1559
aac17941
LT
1560 fd = mkstemp(tmpfile);
1561 if (fd < 0) {
7246ed43 1562 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
1563 return -1;
1564 }
1565
0fcfd160
LT
1566 /* Set it up */
1567 memset(&stream, 0, sizeof(stream));
12f6c308 1568 deflateInit(&stream, zlib_compression_level);
93821bd9 1569 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 1570 compressed = xmalloc(size);
0fcfd160
LT
1571
1572 /* Compress it */
0fcfd160
LT
1573 stream.next_out = compressed;
1574 stream.avail_out = size;
a44c9a5e
LT
1575
1576 /* First header.. */
1577 stream.next_in = hdr;
1578 stream.avail_in = hdrlen;
93821bd9 1579 setup_object_header(&stream, type, len);
a44c9a5e
LT
1580
1581 /* Then the data itself.. */
1582 stream.next_in = buf;
1583 stream.avail_in = len;
0fcfd160
LT
1584 while (deflate(&stream, Z_FINISH) == Z_OK)
1585 /* nothing */;
1586 deflateEnd(&stream);
1587 size = stream.total_out;
1588
4d548150
LT
1589 if (write_buffer(fd, compressed, size) < 0)
1590 die("unable to write sha1 file");
aac17941 1591 fchmod(fd, 0444);
706bc531 1592 close(fd);
383f85b7 1593 free(compressed);
0fcfd160 1594
230f1322 1595 return move_temp_to_file(tmpfile, filename);
0fcfd160 1596}
8237b185 1597
4d548150
LT
1598/*
1599 * We need to unpack and recompress the object for writing
1600 * it out to a different file.
1601 */
1602static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 1603{
4d548150 1604 size_t size;
a5eda52b 1605 z_stream stream;
4d548150
LT
1606 unsigned char *unpacked;
1607 unsigned long len;
1608 char type[20];
1609 char hdr[50];
1610 int hdrlen;
1611 void *buf;
bfc66daf 1612
a9486b02 1613 /* need to unpack and recompress it by itself */
4d548150 1614 unpacked = read_packed_sha1(sha1, type, &len);
a5eda52b 1615
4d548150 1616 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
a5eda52b 1617
4d548150
LT
1618 /* Set it up */
1619 memset(&stream, 0, sizeof(stream));
12f6c308 1620 deflateInit(&stream, zlib_compression_level);
4d548150
LT
1621 size = deflateBound(&stream, len + hdrlen);
1622 buf = xmalloc(size);
a5eda52b 1623
4d548150
LT
1624 /* Compress it */
1625 stream.next_out = buf;
1626 stream.avail_out = size;
a5eda52b 1627
4d548150
LT
1628 /* First header.. */
1629 stream.next_in = (void *)hdr;
1630 stream.avail_in = hdrlen;
1631 while (deflate(&stream, 0) == Z_OK)
1632 /* nothing */;
bfc66daf 1633
4d548150
LT
1634 /* Then the data itself.. */
1635 stream.next_in = unpacked;
1636 stream.avail_in = len;
1637 while (deflate(&stream, Z_FINISH) == Z_OK)
1638 /* nothing */;
1639 deflateEnd(&stream);
1640 free(unpacked);
bfc66daf 1641
4d548150
LT
1642 *objsize = stream.total_out;
1643 return buf;
1644}
1645
1646int write_sha1_to_fd(int fd, const unsigned char *sha1)
1647{
1648 int retval;
1649 unsigned long objsize;
bb6b8e4f 1650 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
1651
1652 if (buf) {
1653 retval = write_buffer(fd, buf, objsize);
1654 munmap(buf, objsize);
1655 return retval;
1656 }
1657
1658 buf = repack_object(sha1, &objsize);
1659 retval = write_buffer(fd, buf, objsize);
1660 free(buf);
1661 return retval;
a5eda52b
DB
1662}
1663
70b9829e
DB
1664int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1665 size_t bufsize, size_t *bufposn)
8237b185 1666{
230f1322 1667 char tmpfile[PATH_MAX];
8237b185
DB
1668 int local;
1669 z_stream stream;
1670 unsigned char real_sha1[20];
bf0f910d 1671 unsigned char discard[4096];
8237b185
DB
1672 int ret;
1673 SHA_CTX c;
1674
230f1322 1675 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
8237b185 1676
230f1322 1677 local = mkstemp(tmpfile);
8237b185 1678 if (local < 0)
bd2afde8
JH
1679 return error("Couldn't open %s for %s",
1680 tmpfile, sha1_to_hex(sha1));
8237b185
DB
1681
1682 memset(&stream, 0, sizeof(stream));
1683
1684 inflateInit(&stream);
1685
1686 SHA1_Init(&c);
1687
1688 do {
1689 ssize_t size;
70b9829e
DB
1690 if (*bufposn) {
1691 stream.avail_in = *bufposn;
96ad15ae 1692 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
1693 do {
1694 stream.next_out = discard;
1695 stream.avail_out = sizeof(discard);
1696 ret = inflate(&stream, Z_SYNC_FLUSH);
1697 SHA1_Update(&c, discard, sizeof(discard) -
1698 stream.avail_out);
1699 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
1700 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1701 die("unable to write sha1 file");
70b9829e
DB
1702 memmove(buffer, buffer + *bufposn - stream.avail_in,
1703 stream.avail_in);
1704 *bufposn = stream.avail_in;
1705 if (ret != Z_OK)
1706 break;
1707 }
1708 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
1709 if (size <= 0) {
1710 close(local);
230f1322 1711 unlink(tmpfile);
8237b185
DB
1712 if (!size)
1713 return error("Connection closed?");
1714 perror("Reading from connection");
1715 return -1;
1716 }
70b9829e
DB
1717 *bufposn += size;
1718 } while (1);
8237b185
DB
1719 inflateEnd(&stream);
1720
1721 close(local);
1722 SHA1_Final(real_sha1, &c);
1723 if (ret != Z_STREAM_END) {
230f1322 1724 unlink(tmpfile);
8237b185
DB
1725 return error("File %s corrupted", sha1_to_hex(sha1));
1726 }
a89fccd2 1727 if (hashcmp(sha1, real_sha1)) {
230f1322 1728 unlink(tmpfile);
bd2afde8 1729 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 1730 }
230f1322
LT
1731
1732 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
1733}
1734
bf592c50
DB
1735int has_pack_index(const unsigned char *sha1)
1736{
1737 struct stat st;
1738 if (stat(sha1_pack_index_name(sha1), &st))
1739 return 0;
1740 return 1;
1741}
1742
1743int has_pack_file(const unsigned char *sha1)
1744{
1745 struct stat st;
1746 if (stat(sha1_pack_name(sha1), &st))
1747 return 0;
1748 return 1;
1749}
1750
dade09c2
LT
1751int has_sha1_pack(const unsigned char *sha1)
1752{
1753 struct pack_entry e;
1754 return find_pack_entry(sha1, &e);
1755}
1756
8237b185
DB
1757int has_sha1_file(const unsigned char *sha1)
1758{
8237b185 1759 struct stat st;
1f688557
JH
1760 struct pack_entry e;
1761
ab90ea5d 1762 if (find_pack_entry(sha1, &e))
1f688557 1763 return 1;
ab90ea5d 1764 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 1765}
74400e71 1766
e7332f96
BE
1767/*
1768 * reads from fd as long as possible into a supplied buffer of size bytes.
82e5a82f 1769 * If necessary the buffer's size is increased using realloc()
e7332f96
BE
1770 *
1771 * returns 0 if anything went fine and -1 otherwise
1772 *
1773 * NOTE: both buf and size may change, but even when -1 is returned
1774 * you still have to free() it yourself.
1775 */
1776int read_pipe(int fd, char** return_buf, unsigned long* return_size)
024510c8 1777{
e7332f96
BE
1778 char* buf = *return_buf;
1779 unsigned long size = *return_size;
1780 int iret;
024510c8 1781 unsigned long off = 0;
e7332f96 1782
024510c8 1783 do {
e7332f96 1784 iret = xread(fd, buf + off, size - off);
024510c8
DB
1785 if (iret > 0) {
1786 off += iret;
1787 if (off == size) {
1788 size *= 2;
1789 buf = realloc(buf, size);
1790 }
1791 }
1792 } while (iret > 0);
e7332f96
BE
1793
1794 *return_buf = buf;
1795 *return_size = off;
1796
1797 if (iret < 0)
1798 return -1;
1799 return 0;
1800}
1801
1802int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1803{
1804 unsigned long size = 4096;
1805 char *buf = malloc(size);
1806 int ret;
1807 unsigned char hdr[50];
1808 int hdrlen;
1809
1810 if (read_pipe(fd, &buf, &size)) {
024510c8
DB
1811 free(buf);
1812 return -1;
1813 }
e7332f96 1814
024510c8 1815 if (!type)
8e440259 1816 type = blob_type;
024510c8 1817 if (write_object)
e7332f96 1818 ret = write_sha1_file(buf, size, type, sha1);
024510c8 1819 else {
e7332f96 1820 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
024510c8
DB
1821 ret = 0;
1822 }
1823 free(buf);
1824 return ret;
1825}
1826
7672db20 1827int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
74400e71 1828{
74400e71 1829 unsigned long size = st->st_size;
aac17941
LT
1830 void *buf;
1831 int ret;
7672db20
BL
1832 unsigned char hdr[50];
1833 int hdrlen;
74400e71 1834
aac17941 1835 buf = "";
74400e71 1836 if (size)
aac17941 1837 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1838 close(fd);
e35f9824 1839 if (buf == MAP_FAILED)
74400e71
JH
1840 return -1;
1841
7672db20 1842 if (!type)
8e440259 1843 type = blob_type;
7672db20
BL
1844 if (write_object)
1845 ret = write_sha1_file(buf, size, type, sha1);
1846 else {
1847 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1848 ret = 0;
1849 }
aac17941
LT
1850 if (size)
1851 munmap(buf, size);
1852 return ret;
74400e71 1853}
ec1fcc16
JH
1854
1855int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1856{
1857 int fd;
1858 char *target;
1859
1860 switch (st->st_mode & S_IFMT) {
1861 case S_IFREG:
1862 fd = open(path, O_RDONLY);
1863 if (fd < 0)
1864 return error("open(\"%s\"): %s", path,
1865 strerror(errno));
1866 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1867 return error("%s: failed to insert into database",
1868 path);
1869 break;
1870 case S_IFLNK:
1871 target = xmalloc(st->st_size+1);
1872 if (readlink(path, target, st->st_size+1) != st->st_size) {
1873 char *errstr = strerror(errno);
1874 free(target);
1875 return error("readlink(\"%s\"): %s", path,
1876 errstr);
1877 }
1878 if (!write_object) {
1879 unsigned char hdr[50];
1880 int hdrlen;
8e440259 1881 write_sha1_file_prepare(target, st->st_size, blob_type,
ec1fcc16 1882 sha1, hdr, &hdrlen);
8e440259 1883 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
ec1fcc16
JH
1884 return error("%s: failed to insert into database",
1885 path);
1886 free(target);
1887 break;
1888 default:
1889 return error("%s: unsupported file type", path);
1890 }
1891 return 0;
1892}