remove an unneeded test
[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
e49521b5
JH
29signed char hexval_table[256] = {
30 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
31 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
32 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
33 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
34 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
35 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
36 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
37 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
38 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
42 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
45 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
46 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
47 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
51 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
62};
0fcfd160
LT
63
64int get_sha1_hex(const char *hex, unsigned char *sha1)
65{
66 int i;
67 for (i = 0; i < 20; i++) {
68 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
69 if (val & ~0xff)
70 return -1;
71 *sha1++ = val;
72 hex += 2;
73 }
74 return 0;
75}
76
b2cb9425
JH
77int safe_create_leading_directories(char *path)
78{
79 char *pos = path;
67d42212
JR
80 struct stat st;
81
67ffdf4c
JS
82 if (*pos == '/')
83 pos++;
b2cb9425
JH
84
85 while (pos) {
86 pos = strchr(pos, '/');
87 if (!pos)
88 break;
89 *pos = 0;
67d42212
JR
90 if (!stat(path, &st)) {
91 /* path exists */
92 if (!S_ISDIR(st.st_mode)) {
b2cb9425 93 *pos = '/';
67d42212 94 return -3;
b2cb9425 95 }
457f06d6 96 }
67d42212
JR
97 else if (mkdir(path, 0777)) {
98 *pos = '/';
99 return -1;
100 }
457f06d6
JS
101 else if (adjust_shared_perm(path)) {
102 *pos = '/';
103 return -2;
104 }
b2cb9425
JH
105 *pos++ = '/';
106 }
107 return 0;
108}
723c31fe 109
0fcfd160
LT
110char * sha1_to_hex(const unsigned char *sha1)
111{
dcb3450f
LT
112 static int bufno;
113 static char hexbuffer[4][50];
0fcfd160 114 static const char hex[] = "0123456789abcdef";
dcb3450f 115 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
116 int i;
117
118 for (i = 0; i < 20; i++) {
119 unsigned int val = *sha1++;
120 *buf++ = hex[val >> 4];
121 *buf++ = hex[val & 0xf];
122 }
1e80e044
JS
123 *buf = '\0';
124
0fcfd160
LT
125 return buffer;
126}
127
ace1534d
JH
128static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
129{
130 int i;
131 for (i = 0; i < 20; i++) {
132 static char hex[] = "0123456789abcdef";
133 unsigned int val = sha1[i];
134 char *pos = pathbuf + i*2 + (i > 0);
135 *pos++ = hex[val >> 4];
136 *pos = hex[val & 0xf];
137 }
138}
139
0fcfd160
LT
140/*
141 * NOTE! This returns a statically allocated buffer, so you have to be
9befac47 142 * careful about using it. Do a "xstrdup()" if you need to save the
0fcfd160 143 * filename.
ace1534d
JH
144 *
145 * Also note that this returns the location for creating. Reading
146 * SHA1 file can happen from any alternate directory listed in the
d19938ab 147 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 148 * the primary object database.
0fcfd160
LT
149 */
150char *sha1_file_name(const unsigned char *sha1)
151{
0fcfd160
LT
152 static char *name, *base;
153
154 if (!base) {
d19938ab 155 const char *sha1_file_directory = get_object_directory();
0fcfd160 156 int len = strlen(sha1_file_directory);
812666c8 157 base = xmalloc(len + 60);
0fcfd160
LT
158 memcpy(base, sha1_file_directory, len);
159 memset(base+len, 0, 60);
160 base[len] = '/';
161 base[len+3] = '/';
162 name = base + len + 1;
163 }
ace1534d 164 fill_sha1_path(name, sha1);
0fcfd160
LT
165 return base;
166}
167
bf592c50
DB
168char *sha1_pack_name(const unsigned char *sha1)
169{
170 static const char hex[] = "0123456789abcdef";
171 static char *name, *base, *buf;
172 int i;
173
174 if (!base) {
175 const char *sha1_file_directory = get_object_directory();
176 int len = strlen(sha1_file_directory);
177 base = xmalloc(len + 60);
178 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
179 name = base + len + 11;
180 }
181
182 buf = name;
183
184 for (i = 0; i < 20; i++) {
185 unsigned int val = *sha1++;
186 *buf++ = hex[val >> 4];
187 *buf++ = hex[val & 0xf];
188 }
189
190 return base;
191}
192
193char *sha1_pack_index_name(const unsigned char *sha1)
194{
195 static const char hex[] = "0123456789abcdef";
196 static char *name, *base, *buf;
197 int i;
198
199 if (!base) {
200 const char *sha1_file_directory = get_object_directory();
201 int len = strlen(sha1_file_directory);
202 base = xmalloc(len + 60);
203 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
204 name = base + len + 11;
205 }
206
207 buf = name;
208
209 for (i = 0; i < 20; i++) {
210 unsigned int val = *sha1++;
211 *buf++ = hex[val >> 4];
212 *buf++ = hex[val & 0xf];
213 }
214
215 return base;
216}
217
d5a63b99
JH
218struct alternate_object_database *alt_odb_list;
219static struct alternate_object_database **alt_odb_tail;
ace1534d 220
c2f493a4
MW
221static void read_info_alternates(const char * alternates, int depth);
222
ddd5d056
JH
223/*
224 * Prepare alternate object database registry.
d5a63b99
JH
225 *
226 * The variable alt_odb_list points at the list of struct
227 * alternate_object_database. The elements on this list come from
228 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
229 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
230 * whose contents is similar to that environment variable but can be
231 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
232 * contains "/the/directory/corresponding/to/.git/objects/...", while
233 * its name points just after the slash at the end of ".git/objects/"
234 * in the example above, and has enough space to hold 40-byte hex
235 * SHA1, an extra slash for the first level indirection, and the
236 * terminating NUL.
ddd5d056 237 */
c2f493a4 238static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 239{
c2f493a4 240 struct stat st;
1494e038 241 const char *objdir = get_object_directory();
c2f493a4
MW
242 struct alternate_object_database *ent;
243 struct alternate_object_database *alt;
244 /* 43 = 40-byte + 2 '/' + terminating NUL */
245 int pfxlen = len;
246 int entlen = pfxlen + 43;
ccfd3e99 247 int base_len = -1;
d5a63b99 248
c2f493a4
MW
249 if (*entry != '/' && relative_base) {
250 /* Relative alt-odb */
251 if (base_len < 0)
252 base_len = strlen(relative_base) + 1;
253 entlen += base_len;
254 pfxlen += base_len;
255 }
256 ent = xmalloc(sizeof(*ent) + entlen);
257
258 if (*entry != '/' && relative_base) {
259 memcpy(ent->base, relative_base, base_len - 1);
260 ent->base[base_len - 1] = '/';
261 memcpy(ent->base + base_len, entry, len);
262 }
263 else
264 memcpy(ent->base, entry, pfxlen);
265
266 ent->name = ent->base + pfxlen + 1;
267 ent->base[pfxlen + 3] = '/';
268 ent->base[pfxlen] = ent->base[entlen-1] = 0;
269
270 /* Detect cases where alternate disappeared */
271 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
272 error("object directory %s does not exist; "
273 "check .git/objects/info/alternates.",
274 ent->base);
275 free(ent);
276 return -1;
277 }
278
279 /* Prevent the common mistake of listing the same
280 * thing twice, or object directory itself.
281 */
282 for (alt = alt_odb_list; alt; alt = alt->next) {
283 if (!memcmp(ent->base, alt->base, pfxlen)) {
284 free(ent);
285 return -1;
286 }
287 }
288 if (!memcmp(ent->base, objdir, pfxlen)) {
289 free(ent);
290 return -1;
291 }
292
293 /* add the alternate entry */
294 *alt_odb_tail = ent;
295 alt_odb_tail = &(ent->next);
296 ent->next = NULL;
297
298 /* recursively add alternates */
299 read_info_alternates(ent->base, depth + 1);
300
301 ent->base[pfxlen] = '/';
302
303 return 0;
304}
305
306static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
307 const char *relative_base, int depth)
308{
309 const char *cp, *last;
310
311 if (depth > 5) {
312 error("%s: ignoring alternate object stores, nesting too deep.",
313 relative_base);
314 return;
315 }
316
d5a63b99 317 last = alt;
9577e7e3
JH
318 while (last < ep) {
319 cp = last;
320 if (cp < ep && *cp == '#') {
321 while (cp < ep && *cp != sep)
322 cp++;
323 last = cp + 1;
324 continue;
325 }
c2f493a4
MW
326 while (cp < ep && *cp != sep)
327 cp++;
d5a63b99 328 if (last != cp) {
c2f493a4
MW
329 if ((*last != '/') && depth) {
330 error("%s: ignoring relative alternate object store %s",
331 relative_base, last);
332 } else {
333 link_alt_odb_entry(last, cp - last,
334 relative_base, depth);
1494e038 335 }
d5a63b99 336 }
9577e7e3 337 while (cp < ep && *cp == sep)
d5a63b99
JH
338 cp++;
339 last = cp;
9577e7e3 340 }
d5a63b99
JH
341}
342
c2f493a4 343static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 344{
9577e7e3 345 char *map;
d5a63b99 346 struct stat st;
c2f493a4
MW
347 char path[PATH_MAX];
348 int fd;
d5a63b99 349
c2f493a4 350 sprintf(path, "%s/info/alternates", relative_base);
d5a63b99
JH
351 fd = open(path, O_RDONLY);
352 if (fd < 0)
353 return;
354 if (fstat(fd, &st) || (st.st_size == 0)) {
355 close(fd);
9a217f2a 356 return;
ace1534d 357 }
d5a63b99
JH
358 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
359 close(fd);
360 if (map == MAP_FAILED)
361 return;
362
c2f493a4
MW
363 link_alt_odb_entries(map, map + st.st_size, '\n', relative_base, depth);
364
d5a63b99 365 munmap(map, st.st_size);
ace1534d
JH
366}
367
c2f493a4
MW
368void prepare_alt_odb(void)
369{
554fe20d 370 const char *alt;
c2f493a4
MW
371
372 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
373 if (!alt) alt = "";
374
375 if (alt_odb_tail)
376 return;
377 alt_odb_tail = &alt_odb_list;
378 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
379
380 read_info_alternates(get_object_directory(), 0);
381}
382
ace1534d
JH
383static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
384{
ace1534d 385 char *name = sha1_file_name(sha1);
d5a63b99 386 struct alternate_object_database *alt;
ace1534d
JH
387
388 if (!stat(name, st))
389 return name;
9a217f2a 390 prepare_alt_odb();
d5a63b99
JH
391 for (alt = alt_odb_list; alt; alt = alt->next) {
392 name = alt->name;
ace1534d 393 fill_sha1_path(name, sha1);
d5a63b99
JH
394 if (!stat(alt->base, st))
395 return alt->base;
ace1534d
JH
396 }
397 return NULL;
398}
399
1f688557
JH
400#define PACK_MAX_SZ (1<<26)
401static int pack_used_ctr;
402static unsigned long pack_mapped;
9a217f2a 403struct packed_git *packed_git;
1f688557 404
1f688557
JH
405static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
406 void **idx_map_)
407{
408 void *idx_map;
409 unsigned int *index;
410 unsigned long idx_size;
411 int nr, i;
e93ec6f9 412 int fd = open(path, O_RDONLY);
1f688557
JH
413 struct stat st;
414 if (fd < 0)
415 return -1;
416 if (fstat(fd, &st)) {
417 close(fd);
418 return -1;
419 }
420 idx_size = st.st_size;
421 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
422 close(fd);
423 if (idx_map == MAP_FAILED)
424 return -1;
425
426 index = idx_map;
4d235c80
LT
427 *idx_map_ = idx_map;
428 *idx_size_ = idx_size;
1f688557
JH
429
430 /* check index map */
f9253394 431 if (idx_size < 4*256 + 20 + 20)
1f688557
JH
432 return error("index file too small");
433 nr = 0;
434 for (i = 0; i < 256; i++) {
435 unsigned int n = ntohl(index[i]);
436 if (n < nr)
437 return error("non-monotonic index");
438 nr = n;
439 }
440
441 /*
442 * Total size:
443 * - 256 index entries 4 bytes each
444 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
445 * - 20-byte SHA1 of the packfile
446 * - 20-byte SHA1 file checksum
447 */
448 if (idx_size != 4*256 + nr * 24 + 20 + 20)
449 return error("wrong index file size");
450
1f688557
JH
451 return 0;
452}
453
f9253394 454static int unuse_one_packed_git(void)
1f688557 455{
f9253394
JH
456 struct packed_git *p, *lru = NULL;
457
458 for (p = packed_git; p; p = p->next) {
459 if (p->pack_use_cnt || !p->pack_base)
460 continue;
461 if (!lru || p->pack_last_used < lru->pack_last_used)
462 lru = p;
463 }
464 if (!lru)
465 return 0;
466 munmap(lru->pack_base, lru->pack_size);
467 lru->pack_base = NULL;
468 return 1;
469}
470
471void unuse_packed_git(struct packed_git *p)
472{
473 p->pack_use_cnt--;
1f688557
JH
474}
475
f9253394 476int use_packed_git(struct packed_git *p)
1f688557 477{
bf592c50
DB
478 if (!p->pack_size) {
479 struct stat st;
a9486b02 480 /* We created the struct before we had the pack */
bf592c50
DB
481 stat(p->pack_name, &st);
482 if (!S_ISREG(st.st_mode))
483 die("packfile %s not a regular file", p->pack_name);
484 p->pack_size = st.st_size;
485 }
1f688557
JH
486 if (!p->pack_base) {
487 int fd;
488 struct stat st;
489 void *map;
da756011 490 struct pack_header *hdr;
1f688557
JH
491
492 pack_mapped += p->pack_size;
f9253394
JH
493 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
494 ; /* nothing */
1f688557
JH
495 fd = open(p->pack_name, O_RDONLY);
496 if (fd < 0)
f9253394 497 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
498 if (fstat(fd, &st)) {
499 close(fd);
f9253394 500 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
501 }
502 if (st.st_size != p->pack_size)
f9253394 503 die("packfile %s size mismatch.", p->pack_name);
1f688557
JH
504 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
505 close(fd);
506 if (map == MAP_FAILED)
f9253394 507 die("packfile %s cannot be mapped.", p->pack_name);
1f688557 508 p->pack_base = map;
f9253394 509
da756011
SP
510 /* Check if we understand this pack file. If we don't we're
511 * likely too old to handle it.
512 */
513 hdr = map;
514 if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
515 die("packfile %s isn't actually a pack.", p->pack_name);
516 if (!pack_version_ok(hdr->hdr_version))
517 die("packfile %s is version %i and not supported"
518 " (try upgrading GIT to a newer version)",
519 p->pack_name, ntohl(hdr->hdr_version));
520
f9253394
JH
521 /* Check if the pack file matches with the index file.
522 * this is cheap.
523 */
a89fccd2
DR
524 if (hashcmp((unsigned char *)(p->index_base) +
525 p->index_size - 40,
526 (unsigned char *)p->pack_base +
527 p->pack_size - 20)) {
f9253394 528 die("packfile %s does not match index.", p->pack_name);
bf592c50 529 }
1f688557
JH
530 }
531 p->pack_last_used = pack_used_ctr++;
f9253394 532 p->pack_use_cnt++;
1f688557
JH
533 return 0;
534}
535
9d835df2 536struct packed_git *add_packed_git(char *path, int path_len, int local)
1f688557
JH
537{
538 struct stat st;
539 struct packed_git *p;
540 unsigned long idx_size;
541 void *idx_map;
c0bbbb1b 542 unsigned char sha1[20];
1f688557
JH
543
544 if (check_packed_git_idx(path, &idx_size, &idx_map))
545 return NULL;
546
547 /* do we have a corresponding .pack file? */
548 strcpy(path + path_len - 4, ".pack");
549 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
550 munmap(idx_map, idx_size);
551 return NULL;
552 }
553 /* ok, it looks sane as far as we can check without
554 * actually mapping the pack file.
555 */
556 p = xmalloc(sizeof(*p) + path_len + 2);
557 strcpy(p->pack_name, path);
558 p->index_size = idx_size;
559 p->pack_size = st.st_size;
560 p->index_base = idx_map;
561 p->next = NULL;
d85a4fee 562 p->pack_base = NULL;
1f688557 563 p->pack_last_used = 0;
f9253394 564 p->pack_use_cnt = 0;
9d835df2 565 p->pack_local = local;
f4a11066 566 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
e702496e 567 hashcpy(p->sha1, sha1);
1f688557
JH
568 return p;
569}
570
bf592c50 571struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
572{
573 char *path = sha1_pack_index_name(sha1);
574 return parse_pack_index_file(sha1, path);
575}
576
2ab141a2 577struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
bf592c50
DB
578{
579 struct packed_git *p;
580 unsigned long idx_size;
581 void *idx_map;
c508df5e 582 char *path;
bf592c50 583
c508df5e 584 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
bf592c50
DB
585 return NULL;
586
587 path = sha1_pack_name(sha1);
588
589 p = xmalloc(sizeof(*p) + strlen(path) + 2);
590 strcpy(p->pack_name, path);
591 p->index_size = idx_size;
592 p->pack_size = 0;
593 p->index_base = idx_map;
594 p->next = NULL;
595 p->pack_base = NULL;
596 p->pack_last_used = 0;
597 p->pack_use_cnt = 0;
e702496e 598 hashcpy(p->sha1, sha1);
bf592c50
DB
599 return p;
600}
601
602void install_packed_git(struct packed_git *pack)
603{
604 pack->next = packed_git;
605 packed_git = pack;
606}
607
9d835df2 608static void prepare_packed_git_one(char *objdir, int local)
1f688557
JH
609{
610 char path[PATH_MAX];
611 int len;
612 DIR *dir;
613 struct dirent *de;
614
615 sprintf(path, "%s/pack", objdir);
616 len = strlen(path);
617 dir = opendir(path);
b5b16990 618 if (!dir) {
26125f6b 619 if (errno != ENOENT)
bd2afde8 620 error("unable to open object pack directory: %s: %s",
26125f6b 621 path, strerror(errno));
1f688557 622 return;
b5b16990 623 }
1f688557
JH
624 path[len++] = '/';
625 while ((de = readdir(dir)) != NULL) {
626 int namelen = strlen(de->d_name);
627 struct packed_git *p;
628
5bb1cda5 629 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
630 continue;
631
632 /* we have .idx. Is it a file we can map? */
633 strcpy(path + len, de->d_name);
86f7780c
JK
634 for (p = packed_git; p; p = p->next) {
635 if (!memcmp(path, p->pack_name, len + namelen - 4))
636 break;
637 }
638 if (p)
639 continue;
9d835df2 640 p = add_packed_git(path, len + namelen, local);
1f688557
JH
641 if (!p)
642 continue;
643 p->next = packed_git;
644 packed_git = p;
645 }
5b35bcd5 646 closedir(dir);
1f688557
JH
647}
648
637cdd9d 649static int prepare_packed_git_run_once = 0;
9a217f2a 650void prepare_packed_git(void)
1f688557 651{
d5a63b99 652 struct alternate_object_database *alt;
1f688557 653
637cdd9d 654 if (prepare_packed_git_run_once)
1f688557 655 return;
9d835df2 656 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 657 prepare_alt_odb();
d5a63b99 658 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 659 alt->name[-1] = 0;
9d835df2 660 prepare_packed_git_one(alt->base, 0);
1494e038 661 alt->name[-1] = '/';
1f688557 662 }
637cdd9d
JK
663 prepare_packed_git_run_once = 1;
664}
665
666static void reprepare_packed_git(void)
667{
668 prepare_packed_git_run_once = 0;
669 prepare_packed_git();
1f688557
JH
670}
671
5d6ccf5c 672int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
673{
674 unsigned char real_sha1[20];
7cfb5f36 675 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 676 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
677}
678
bb6b8e4f 679void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 680{
0fcfd160
LT
681 struct stat st;
682 void *map;
144bde78 683 int fd;
ace1534d
JH
684 char *filename = find_sha1_file(sha1, &st);
685
686 if (!filename) {
ace1534d
JH
687 return NULL;
688 }
0fcfd160 689
144bde78 690 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 691 if (fd < 0) {
144bde78
LT
692 /* See if it works without O_NOATIME */
693 switch (sha1_file_open_flag) {
694 default:
695 fd = open(filename, O_RDONLY);
696 if (fd >= 0)
697 break;
698 /* Fallthrough */
699 case 0:
144bde78
LT
700 return NULL;
701 }
702
1f688557
JH
703 /* If it failed once, it will probably fail again.
704 * Stop using O_NOATIME
705 */
144bde78 706 sha1_file_open_flag = 0;
0fcfd160 707 }
0fcfd160
LT
708 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
709 close(fd);
e35f9824 710 if (map == MAP_FAILED)
0fcfd160
LT
711 return NULL;
712 *size = st.st_size;
713 return map;
714}
715
bb6b8e4f
JH
716int legacy_loose_object(unsigned char *map)
717{
718 unsigned int word;
719
720 /*
721 * Is it a zlib-compressed buffer? If so, the first byte
722 * must be 0x78 (15-bit window size, deflated), and the
723 * first 16-bit word is evenly divisible by 31
724 */
725 word = (map[0] << 8) + map[1];
726 if (map[0] == 0x78 && !(word % 31))
727 return 1;
728 else
729 return 0;
730}
731
72518e9c 732unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 733{
ad1ed5ee 734 unsigned shift;
93821bd9 735 unsigned char c;
93821bd9 736 unsigned long size;
ad1ed5ee
JH
737 unsigned long used = 0;
738
739 c = buf[used++];
740 *type = (c >> 4) & 7;
741 size = c & 15;
742 shift = 4;
743 while (c & 0x80) {
744 if (len <= used)
745 return 0;
746 if (sizeof(long) * 8 <= shift)
747 return 0;
748 c = buf[used++];
749 size += (c & 0x7f) << shift;
750 shift += 7;
751 }
752 *sizep = size;
753 return used;
754}
755
756static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
757{
758 unsigned long size, used;
759 static const char valid_loose_object_type[8] = {
760 0, /* OBJ_EXT */
761 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
762 0, /* "delta" and others are invalid in a loose object */
93821bd9 763 };
ad1ed5ee 764 enum object_type type;
93821bd9 765
c4483576
LT
766 /* Get the data stream */
767 memset(stream, 0, sizeof(*stream));
768 stream->next_in = map;
769 stream->avail_in = mapsize;
770 stream->next_out = buffer;
93821bd9
LT
771 stream->avail_out = bufsiz;
772
bb6b8e4f 773 if (legacy_loose_object(map)) {
93821bd9
LT
774 inflateInit(stream);
775 return inflate(stream, 0);
776 }
777
ad1ed5ee
JH
778 used = unpack_object_header_gently(map, mapsize, &type, &size);
779 if (!used || !valid_loose_object_type[type])
93821bd9 780 return -1;
ad1ed5ee
JH
781 map += used;
782 mapsize -= used;
93821bd9
LT
783
784 /* Set up the stream for the rest.. */
785 stream->next_in = map;
786 stream->avail_in = mapsize;
c4483576 787 inflateInit(stream);
93821bd9
LT
788
789 /* And generate the fake traditional header */
ad1ed5ee
JH
790 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
791 type_names[type], size);
93821bd9 792 return 0;
c4483576
LT
793}
794
6da4016a 795static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
5180cacc
LT
796{
797 int bytes = strlen(buffer) + 1;
d565b341 798 unsigned char *buf = xmalloc(1+size);
93821bd9 799 unsigned long n;
5180cacc 800
93821bd9
LT
801 n = stream->total_out - bytes;
802 if (n > size)
803 n = size;
804 memcpy(buf, (char *) buffer + bytes, n);
805 bytes = n;
5180cacc
LT
806 if (bytes < size) {
807 stream->next_out = buf + bytes;
808 stream->avail_out = size - bytes;
809 while (inflate(stream, Z_FINISH) == Z_OK)
810 /* nothing */;
811 }
812 buf[size] = 0;
813 inflateEnd(stream);
814 return buf;
815}
816
817/*
818 * We used to just use "sscanf()", but that's actually way
819 * too permissive for what we want to check. So do an anal
820 * object header parse by hand.
821 */
38d3874d 822static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
5180cacc
LT
823{
824 int i;
825 unsigned long size;
826
827 /*
828 * The type can be at most ten bytes (including the
829 * terminating '\0' that we add), and is followed by
830 * a space.
831 */
832 i = 10;
833 for (;;) {
834 char c = *hdr++;
835 if (c == ' ')
836 break;
837 if (!--i)
838 return -1;
839 *type++ = c;
840 }
841 *type = 0;
842
843 /*
844 * The length must follow immediately, and be in canonical
845 * decimal format (ie "010" is not valid).
846 */
847 size = *hdr++ - '0';
848 if (size > 9)
849 return -1;
850 if (size) {
851 for (;;) {
852 unsigned long c = *hdr - '0';
853 if (c > 9)
854 break;
855 hdr++;
856 size = size * 10 + c;
857 }
858 }
859 *sizep = size;
860
861 /*
862 * The length must be followed by a zero byte
863 */
864 return *hdr ? -1 : 0;
865}
866
0fcfd160
LT
867void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
868{
5180cacc 869 int ret;
0fcfd160 870 z_stream stream;
5180cacc 871 char hdr[8192];
0fcfd160 872
5180cacc
LT
873 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
874 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
875 return NULL;
876
5180cacc 877 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
878}
879
f3bf9224 880/* forward declaration for a mutually recursive function */
43057304 881static int packed_object_info(struct packed_git *p, unsigned long offset,
f3bf9224
JH
882 char *type, unsigned long *sizep);
883
43057304
NP
884static int packed_delta_info(struct packed_git *p,
885 unsigned long offset,
5db47c2b 886 char *type,
43057304 887 unsigned long *sizep)
5db47c2b 888{
43057304
NP
889 unsigned long base_offset;
890 unsigned char *base_sha1 = (unsigned char *) p->pack_base + offset;
f3bf9224 891
43057304 892 if (p->pack_size < offset + 20)
5db47c2b 893 die("truncated pack file");
f3bf9224 894 /* The base entry _must_ be in the same pack */
43057304
NP
895 base_offset = find_pack_entry_one(base_sha1, p);
896 if (!base_offset)
f3bf9224
JH
897 die("failed to find delta-pack base object %s",
898 sha1_to_hex(base_sha1));
43057304 899 offset += 20;
f3bf9224 900
c62266f3
JH
901 /* We choose to only get the type of the base object and
902 * ignore potentially corrupt pack file that expects the delta
903 * based on a base with a wrong size. This saves tons of
904 * inflate() calls.
905 */
43057304 906 if (packed_object_info(p, base_offset, type, NULL))
c62266f3 907 die("cannot get info for delta-pack base");
5db47c2b 908
c62266f3
JH
909 if (sizep) {
910 const unsigned char *data;
1a3b55c6 911 unsigned char delta_head[20];
c62266f3
JH
912 unsigned long result_size;
913 z_stream stream;
914 int st;
915
916 memset(&stream, 0, sizeof(stream));
917
43057304
NP
918 stream.next_in = (unsigned char *) p->pack_base + offset;
919 stream.avail_in = p->pack_size - offset;
c62266f3
JH
920 stream.next_out = delta_head;
921 stream.avail_out = sizeof(delta_head);
922
923 inflateInit(&stream);
924 st = inflate(&stream, Z_FINISH);
925 inflateEnd(&stream);
926 if ((st != Z_STREAM_END) &&
927 stream.total_out != sizeof(delta_head))
928 die("delta data unpack-initial failed");
929
930 /* Examine the initial part of the delta to figure out
931 * the result size.
932 */
933 data = delta_head;
8960844a
NP
934
935 /* ignore base size */
936 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
5db47c2b 937
c62266f3 938 /* Read the result size */
8960844a 939 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
c62266f3
JH
940 *sizep = result_size;
941 }
5db47c2b
JH
942 return 0;
943}
944
a733cb60
LT
945static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
946 enum object_type *type, unsigned long *sizep)
947{
ad1ed5ee 948 unsigned long used;
a733cb60 949
ad1ed5ee 950 if (p->pack_size <= offset)
a733cb60 951 die("object offset outside of pack file");
ad1ed5ee
JH
952
953 used = unpack_object_header_gently((unsigned char *)p->pack_base +
954 offset,
955 p->pack_size - offset, type, sizep);
956 if (!used)
957 die("object offset outside of pack file");
958
959 return offset + used;
a733cb60
LT
960}
961
a49dd05f
JH
962int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
963 unsigned char *base, unsigned long *sizep,
964 enum object_type *kindp)
965{
966 unsigned long ptr;
967 int status = -1;
968
969 use_packed_git(p);
970 ptr = offset;
971 ptr = unpack_object_header(p, ptr, kindp, sizep);
972 if (*kindp != OBJ_DELTA)
973 goto done;
e702496e 974 hashcpy(base, (unsigned char *) p->pack_base + ptr);
a49dd05f
JH
975 status = 0;
976 done:
977 unuse_packed_git(p);
978 return status;
979}
980
43057304
NP
981void packed_object_info_detail(struct packed_git *p,
982 unsigned long offset,
ad8c80a5
JH
983 char *type,
984 unsigned long *size,
985 unsigned long *store_size,
f8f135c9 986 unsigned int *delta_chain_length,
ad8c80a5
JH
987 unsigned char *base_sha1)
988{
43057304
NP
989 unsigned long val;
990 unsigned char *next_sha1;
ad8c80a5
JH
991 enum object_type kind;
992
43057304
NP
993 *delta_chain_length = 0;
994 offset = unpack_object_header(p, offset, &kind, size);
995
996 for (;;) {
997 switch (kind) {
998 default:
999 die("corrupted pack file %s containing object of kind %d",
1000 p->pack_name, kind);
1001 case OBJ_COMMIT:
1002 case OBJ_TREE:
1003 case OBJ_BLOB:
1004 case OBJ_TAG:
1005 strcpy(type, type_names[kind]);
1006 *store_size = 0; /* notyet */
1007 return;
1008 case OBJ_DELTA:
1009 if (p->pack_size <= offset + 20)
1010 die("pack file %s records an incomplete delta base",
1011 p->pack_name);
1012 next_sha1 = (unsigned char *) p->pack_base + offset;
1013 if (*delta_chain_length == 0)
1014 hashcpy(base_sha1, next_sha1);
1015 offset = find_pack_entry_one(next_sha1, p);
1016 break;
1017 }
1018 offset = unpack_object_header(p, offset, &kind, &val);
1019 (*delta_chain_length)++;
ad8c80a5 1020 }
ad8c80a5
JH
1021}
1022
43057304 1023static int packed_object_info(struct packed_git *p, unsigned long offset,
1f688557
JH
1024 char *type, unsigned long *sizep)
1025{
43057304 1026 unsigned long size;
a733cb60 1027 enum object_type kind;
5db47c2b 1028
43057304 1029 offset = unpack_object_header(p, offset, &kind, &size);
5db47c2b 1030
43057304
NP
1031 if (kind == OBJ_DELTA)
1032 return packed_delta_info(p, offset, type, sizep);
a733cb60
LT
1033
1034 switch (kind) {
a733cb60 1035 case OBJ_COMMIT:
a733cb60 1036 case OBJ_TREE:
a733cb60 1037 case OBJ_BLOB:
a733cb60 1038 case OBJ_TAG:
5a18f540 1039 strcpy(type, type_names[kind]);
a69d0943 1040 break;
1f688557 1041 default:
264b16b6
JH
1042 die("corrupted pack file %s containing object of kind %d",
1043 p->pack_name, kind);
1f688557 1044 }
c62266f3
JH
1045 if (sizep)
1046 *sizep = size;
1f688557
JH
1047 return 0;
1048}
1049
eb950c19
SP
1050static void *unpack_compressed_entry(struct packed_git *p,
1051 unsigned long offset,
1052 unsigned long size)
de530aaa
SP
1053{
1054 int st;
1055 z_stream stream;
1056 unsigned char *buffer;
1057
1058 buffer = xmalloc(size + 1);
1059 buffer[size] = 0;
1060 memset(&stream, 0, sizeof(stream));
eb950c19
SP
1061 stream.next_in = (unsigned char*)p->pack_base + offset;
1062 stream.avail_in = p->pack_size - offset;
de530aaa
SP
1063 stream.next_out = buffer;
1064 stream.avail_out = size;
1065
1066 inflateInit(&stream);
1067 st = inflate(&stream, Z_FINISH);
1068 inflateEnd(&stream);
1069 if ((st != Z_STREAM_END) || stream.total_out != size) {
1070 free(buffer);
1071 return NULL;
1072 }
1073
1074 return buffer;
1075}
1076
eb950c19
SP
1077static void *unpack_delta_entry(struct packed_git *p,
1078 unsigned long offset,
1f688557 1079 unsigned long delta_size,
1f688557 1080 char *type,
eb950c19 1081 unsigned long *sizep)
1f688557 1082{
7c3e8be3 1083 void *delta_data, *result, *base;
43057304
NP
1084 unsigned long result_size, base_size, base_offset;
1085 unsigned char *base_sha1;
1f688557 1086
43057304 1087 if (p->pack_size < offset + 20)
1f688557 1088 die("truncated pack file");
67686d95 1089 /* The base entry _must_ be in the same pack */
eb950c19 1090 base_sha1 = (unsigned char*)p->pack_base + offset;
43057304
NP
1091 base_offset = find_pack_entry_one(base_sha1, p);
1092 if (!base_offset)
67686d95
JH
1093 die("failed to find delta-pack base object %s",
1094 sha1_to_hex(base_sha1));
43057304
NP
1095 offset += 20;
1096
1097 base = unpack_entry_gently(p, base_offset, type, &base_size);
67686d95 1098 if (!base)
43057304
NP
1099 die("failed to read delta base object at %lu from %s",
1100 base_offset, p->pack_name);
67686d95 1101
43057304 1102 delta_data = unpack_compressed_entry(p, offset, delta_size);
1f688557
JH
1103 result = patch_delta(base, base_size,
1104 delta_data, delta_size,
1105 &result_size);
1106 if (!result)
1107 die("failed to apply delta");
1108 free(delta_data);
1109 free(base);
1110 *sizep = result_size;
1111 return result;
1112}
1113
1f688557
JH
1114static void *unpack_entry(struct pack_entry *entry,
1115 char *type, unsigned long *sizep)
1116{
1117 struct packed_git *p = entry->p;
f9253394 1118 void *retval;
1f688557
JH
1119
1120 if (use_packed_git(p))
1121 die("cannot map packed file");
43057304 1122 retval = unpack_entry_gently(p, entry->offset, type, sizep);
f3bf9224
JH
1123 unuse_packed_git(p);
1124 if (!retval)
264b16b6 1125 die("corrupted pack file %s", p->pack_name);
f3bf9224
JH
1126 return retval;
1127}
1128
1129/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
43057304 1130void *unpack_entry_gently(struct packed_git *p, unsigned long offset,
f3bf9224
JH
1131 char *type, unsigned long *sizep)
1132{
43057304 1133 unsigned long size;
f3bf9224 1134 enum object_type kind;
1f688557 1135
43057304 1136 offset = unpack_object_header(p, offset, &kind, &size);
a733cb60
LT
1137 switch (kind) {
1138 case OBJ_DELTA:
eb950c19 1139 return unpack_delta_entry(p, offset, size, type, sizep);
a733cb60 1140 case OBJ_COMMIT:
a733cb60 1141 case OBJ_TREE:
a733cb60 1142 case OBJ_BLOB:
a733cb60 1143 case OBJ_TAG:
5a18f540
SP
1144 strcpy(type, type_names[kind]);
1145 *sizep = size;
eb950c19 1146 return unpack_compressed_entry(p, offset, size);
1f688557 1147 default:
f3bf9224 1148 return NULL;
1f688557 1149 }
1f688557
JH
1150}
1151
9a217f2a
JH
1152int num_packed_objects(const struct packed_git *p)
1153{
f9253394 1154 /* See check_packed_git_idx() */
9a217f2a
JH
1155 return (p->index_size - 20 - 20 - 4*256) / 24;
1156}
1157
1158int nth_packed_object_sha1(const struct packed_git *p, int n,
1159 unsigned char* sha1)
1160{
1161 void *index = p->index_base + 256;
1162 if (n < 0 || num_packed_objects(p) <= n)
1163 return -1;
e702496e 1164 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
9a217f2a
JH
1165 return 0;
1166}
1167
43057304
NP
1168unsigned long find_pack_entry_one(const unsigned char *sha1,
1169 struct packed_git *p)
1f688557 1170{
4d235c80 1171 unsigned int *level1_ofs = p->index_base;
1f688557
JH
1172 int hi = ntohl(level1_ofs[*sha1]);
1173 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1174 void *index = p->index_base + 256;
1175
1176 do {
1177 int mi = (lo + hi) / 2;
a89fccd2 1178 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
43057304
NP
1179 if (!cmp)
1180 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1f688557
JH
1181 if (cmp > 0)
1182 hi = mi;
1183 else
1184 lo = mi+1;
1185 } while (lo < hi);
1186 return 0;
1187}
1188
106d710b 1189static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557
JH
1190{
1191 struct packed_git *p;
43057304
NP
1192 unsigned long offset;
1193
1f688557
JH
1194 prepare_packed_git();
1195
1196 for (p = packed_git; p; p = p->next) {
106d710b
JH
1197 if (ignore_packed) {
1198 const char **ig;
1199 for (ig = ignore_packed; *ig; ig++)
1200 if (!strcmp(p->pack_name, *ig))
1201 break;
1202 if (*ig)
1203 continue;
1204 }
43057304
NP
1205 offset = find_pack_entry_one(sha1, p);
1206 if (offset) {
1207 e->offset = offset;
1208 e->p = p;
1209 hashcpy(e->sha1, sha1);
1f688557 1210 return 1;
43057304 1211 }
1f688557
JH
1212 }
1213 return 0;
1214}
1215
bf592c50
DB
1216struct packed_git *find_sha1_pack(const unsigned char *sha1,
1217 struct packed_git *packs)
1218{
1219 struct packed_git *p;
bf592c50
DB
1220
1221 for (p = packs; p; p = p->next) {
43057304 1222 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1223 return p;
1224 }
1225 return NULL;
1226
1227}
1228
36e4d74a 1229int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1230{
36e4d74a 1231 int status;
65c2e0c3
JH
1232 unsigned long mapsize, size;
1233 void *map;
1234 z_stream stream;
36e4d74a 1235 char hdr[128];
65c2e0c3 1236
bb6b8e4f 1237 map = map_sha1_file(sha1, &mapsize);
1f688557
JH
1238 if (!map) {
1239 struct pack_entry e;
1240
43057304
NP
1241 if (!find_pack_entry(sha1, &e, NULL)) {
1242 reprepare_packed_git();
1243 if (!find_pack_entry(sha1, &e, NULL))
1244 return error("unable to find %s", sha1_to_hex(sha1));
1245 }
1246 if (use_packed_git(e.p))
1247 die("cannot map packed file");
1248 status = packed_object_info(e.p, e.offset, type, sizep);
1249 unuse_packed_git(e.p);
1250 return status;
1f688557 1251 }
36e4d74a
JH
1252 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1253 status = error("unable to unpack %s header",
1254 sha1_to_hex(sha1));
1255 if (parse_sha1_header(hdr, type, &size) < 0)
1256 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1257 else {
65c2e0c3 1258 status = 0;
c62266f3
JH
1259 if (sizep)
1260 *sizep = size;
65c2e0c3 1261 }
65c2e0c3
JH
1262 inflateEnd(&stream);
1263 munmap(map, mapsize);
1264 return status;
1265}
1266
1f688557
JH
1267static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1268{
1269 struct pack_entry e;
1270
106d710b 1271 if (!find_pack_entry(sha1, &e, NULL)) {
1f688557
JH
1272 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1273 return NULL;
1274 }
1275 return unpack_entry(&e, type, size);
1276}
1277
0fcfd160
LT
1278void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1279{
1280 unsigned long mapsize;
1281 void *map, *buf;
ab90ea5d 1282 struct pack_entry e;
0fcfd160 1283
106d710b 1284 if (find_pack_entry(sha1, &e, NULL))
ab90ea5d 1285 return read_packed_sha1(sha1, type, size);
bb6b8e4f 1286 map = map_sha1_file(sha1, &mapsize);
0fcfd160
LT
1287 if (map) {
1288 buf = unpack_sha1_file(map, mapsize, type, size);
1289 munmap(map, mapsize);
1290 return buf;
1291 }
637cdd9d 1292 reprepare_packed_git();
106d710b 1293 if (find_pack_entry(sha1, &e, NULL))
637cdd9d 1294 return read_packed_sha1(sha1, type, size);
ab90ea5d 1295 return NULL;
0fcfd160
LT
1296}
1297
40469ee9 1298void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1299 const char *required_type,
40469ee9
JH
1300 unsigned long *size,
1301 unsigned char *actual_sha1_return)
f4913f91
JH
1302{
1303 char type[20];
1304 void *buffer;
1305 unsigned long isize;
40469ee9 1306 unsigned char actual_sha1[20];
f4913f91 1307
e702496e 1308 hashcpy(actual_sha1, sha1);
40469ee9
JH
1309 while (1) {
1310 int ref_length = -1;
1311 const char *ref_type = NULL;
f4913f91 1312
40469ee9
JH
1313 buffer = read_sha1_file(actual_sha1, type, &isize);
1314 if (!buffer)
1315 return NULL;
1316 if (!strcmp(type, required_type)) {
1317 *size = isize;
1318 if (actual_sha1_return)
e702496e 1319 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1320 return buffer;
1321 }
1322 /* Handle references */
8e440259 1323 else if (!strcmp(type, commit_type))
40469ee9 1324 ref_type = "tree ";
8e440259 1325 else if (!strcmp(type, tag_type))
40469ee9
JH
1326 ref_type = "object ";
1327 else {
1328 free(buffer);
1329 return NULL;
1330 }
1331 ref_length = strlen(ref_type);
f4913f91 1332
40469ee9 1333 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1334 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1335 free(buffer);
1336 return NULL;
1337 }
1cf58e72 1338 free(buffer);
40469ee9
JH
1339 /* Now we have the ID of the referred-to object in
1340 * actual_sha1. Check again. */
f4913f91 1341 }
f4913f91
JH
1342}
1343
972a9155
RS
1344static void write_sha1_file_prepare(void *buf, unsigned long len,
1345 const char *type, unsigned char *sha1,
1346 unsigned char *hdr, int *hdrlen)
d410c0f5
JH
1347{
1348 SHA_CTX c;
1349
1350 /* Generate the header */
1351 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1352
1353 /* Sha1.. */
1354 SHA1_Init(&c);
1355 SHA1_Update(&c, hdr, *hdrlen);
1356 SHA1_Update(&c, buf, len);
1357 SHA1_Final(sha1, &c);
d410c0f5
JH
1358}
1359
230f1322
LT
1360/*
1361 * Link the tempfile to the final place, possibly creating the
1362 * last directory level as you do so.
1363 *
1364 * Returns the errno on failure, 0 on success.
1365 */
839837b9 1366static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1367{
1368 int ret;
756aaf4a 1369 char *dir;
230f1322
LT
1370
1371 if (!link(tmpfile, filename))
1372 return 0;
1373
1374 /*
756aaf4a 1375 * Try to mkdir the last path component if that failed.
230f1322
LT
1376 *
1377 * Re-try the "link()" regardless of whether the mkdir
1378 * succeeds, since a race might mean that somebody
1379 * else succeeded.
1380 */
1381 ret = errno;
756aaf4a
SP
1382 dir = strrchr(filename, '/');
1383 if (dir) {
1384 *dir = 0;
866cae0d 1385 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
91c23e48 1386 *dir = '/';
756aaf4a 1387 return -2;
91c23e48 1388 }
756aaf4a
SP
1389 *dir = '/';
1390 if (!link(tmpfile, filename))
1391 return 0;
1392 ret = errno;
230f1322
LT
1393 }
1394 return ret;
1395}
1396
1397/*
1398 * Move the just written object into its final resting place
1399 */
839837b9 1400int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1401{
1402 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
1403
1404 /*
1405 * Coda hack - coda doesn't like cross-directory links,
1406 * so we fall back to a rename, which will mean that it
1407 * won't be able to check collisions, but that's not a
1408 * big deal.
1409 *
1410 * The same holds for FAT formatted media.
1411 *
1412 * When this succeeds, we just return 0. We have nothing
1413 * left to unlink.
1414 */
1415 if (ret && ret != EEXIST) {
1416 if (!rename(tmpfile, filename))
230f1322 1417 return 0;
9e48b389 1418 ret = errno;
230f1322
LT
1419 }
1420 unlink(tmpfile);
1421 if (ret) {
1422 if (ret != EEXIST) {
7246ed43 1423 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
1424 return -1;
1425 }
1426 /* FIXME!!! Collision check here ? */
1427 }
1428
1429 return 0;
1430}
1431
4d548150
LT
1432static int write_buffer(int fd, const void *buf, size_t len)
1433{
1434 while (len) {
1435 ssize_t size;
1436
1437 size = write(fd, buf, len);
1438 if (!size)
1439 return error("file write: disk full");
1440 if (size < 0) {
1441 if (errno == EINTR || errno == EAGAIN)
1442 continue;
1443 return error("file write error (%s)", strerror(errno));
1444 }
1445 len -= size;
1d7f171c 1446 buf = (char *) buf + size;
4d548150
LT
1447 }
1448 return 0;
1449}
1450
93821bd9
LT
1451static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1452{
1453 int hdr_len;
1454 unsigned char c;
1455
1456 c = (type << 4) | (len & 15);
1457 len >>= 4;
1458 hdr_len = 1;
1459 while (len) {
1460 *hdr++ = c | 0x80;
1461 hdr_len++;
1462 c = (len & 0x7f);
1463 len >>= 7;
1464 }
1465 *hdr = c;
1466 return hdr_len;
1467}
1468
1469static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1470{
1471 int obj_type, hdr;
1472
1473 if (use_legacy_headers) {
1474 while (deflate(stream, 0) == Z_OK)
1475 /* nothing */;
1476 return;
1477 }
1478 if (!strcmp(type, blob_type))
1479 obj_type = OBJ_BLOB;
1480 else if (!strcmp(type, tree_type))
1481 obj_type = OBJ_TREE;
1482 else if (!strcmp(type, commit_type))
1483 obj_type = OBJ_COMMIT;
1484 else if (!strcmp(type, tag_type))
1485 obj_type = OBJ_TAG;
1486 else
1487 die("trying to generate bogus object of type '%s'", type);
1488 hdr = write_binary_header(stream->next_out, obj_type, len);
1489 stream->total_out = hdr;
1490 stream->next_out += hdr;
1491 stream->avail_out -= hdr;
1492}
1493
abdc3fc8
RS
1494int hash_sha1_file(void *buf, unsigned long len, const char *type,
1495 unsigned char *sha1)
1496{
1497 unsigned char hdr[50];
1498 int hdrlen;
1499 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1500 return 0;
1501}
1502
bf0f910d 1503int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1504{
1505 int size;
bf0f910d 1506 unsigned char *compressed;
0fcfd160
LT
1507 z_stream stream;
1508 unsigned char sha1[20];
706bc531 1509 char *filename;
aac17941 1510 static char tmpfile[PATH_MAX];
bf0f910d 1511 unsigned char hdr[50];
230f1322 1512 int fd, hdrlen;
a44c9a5e 1513
d410c0f5
JH
1514 /* Normally if we have it in the pack then we do not bother writing
1515 * it out into .git/objects/??/?{38} file.
1516 */
972a9155
RS
1517 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1518 filename = sha1_file_name(sha1);
706bc531 1519 if (returnsha1)
e702496e 1520 hashcpy(returnsha1, sha1);
d410c0f5
JH
1521 if (has_sha1_file(sha1))
1522 return 0;
aac17941
LT
1523 fd = open(filename, O_RDONLY);
1524 if (fd >= 0) {
706bc531 1525 /*
aac17941
LT
1526 * FIXME!!! We might do collision checking here, but we'd
1527 * need to uncompress the old file and check it. Later.
706bc531 1528 */
aac17941 1529 close(fd);
706bc531
LT
1530 return 0;
1531 }
1532
aac17941 1533 if (errno != ENOENT) {
7246ed43 1534 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
1535 return -1;
1536 }
1537
1538 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1539
aac17941
LT
1540 fd = mkstemp(tmpfile);
1541 if (fd < 0) {
7246ed43 1542 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
1543 return -1;
1544 }
1545
0fcfd160
LT
1546 /* Set it up */
1547 memset(&stream, 0, sizeof(stream));
12f6c308 1548 deflateInit(&stream, zlib_compression_level);
93821bd9 1549 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 1550 compressed = xmalloc(size);
0fcfd160
LT
1551
1552 /* Compress it */
0fcfd160
LT
1553 stream.next_out = compressed;
1554 stream.avail_out = size;
a44c9a5e
LT
1555
1556 /* First header.. */
1557 stream.next_in = hdr;
1558 stream.avail_in = hdrlen;
93821bd9 1559 setup_object_header(&stream, type, len);
a44c9a5e
LT
1560
1561 /* Then the data itself.. */
1562 stream.next_in = buf;
1563 stream.avail_in = len;
0fcfd160
LT
1564 while (deflate(&stream, Z_FINISH) == Z_OK)
1565 /* nothing */;
1566 deflateEnd(&stream);
1567 size = stream.total_out;
1568
4d548150
LT
1569 if (write_buffer(fd, compressed, size) < 0)
1570 die("unable to write sha1 file");
aac17941 1571 fchmod(fd, 0444);
706bc531 1572 close(fd);
383f85b7 1573 free(compressed);
0fcfd160 1574
230f1322 1575 return move_temp_to_file(tmpfile, filename);
0fcfd160 1576}
8237b185 1577
4d548150
LT
1578/*
1579 * We need to unpack and recompress the object for writing
1580 * it out to a different file.
1581 */
1582static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 1583{
4d548150 1584 size_t size;
a5eda52b 1585 z_stream stream;
4d548150
LT
1586 unsigned char *unpacked;
1587 unsigned long len;
1588 char type[20];
1589 char hdr[50];
1590 int hdrlen;
1591 void *buf;
bfc66daf 1592
a9486b02 1593 /* need to unpack and recompress it by itself */
4d548150 1594 unpacked = read_packed_sha1(sha1, type, &len);
a5eda52b 1595
4d548150 1596 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
a5eda52b 1597
4d548150
LT
1598 /* Set it up */
1599 memset(&stream, 0, sizeof(stream));
12f6c308 1600 deflateInit(&stream, zlib_compression_level);
4d548150
LT
1601 size = deflateBound(&stream, len + hdrlen);
1602 buf = xmalloc(size);
a5eda52b 1603
4d548150
LT
1604 /* Compress it */
1605 stream.next_out = buf;
1606 stream.avail_out = size;
a5eda52b 1607
4d548150
LT
1608 /* First header.. */
1609 stream.next_in = (void *)hdr;
1610 stream.avail_in = hdrlen;
1611 while (deflate(&stream, 0) == Z_OK)
1612 /* nothing */;
bfc66daf 1613
4d548150
LT
1614 /* Then the data itself.. */
1615 stream.next_in = unpacked;
1616 stream.avail_in = len;
1617 while (deflate(&stream, Z_FINISH) == Z_OK)
1618 /* nothing */;
1619 deflateEnd(&stream);
1620 free(unpacked);
bfc66daf 1621
4d548150
LT
1622 *objsize = stream.total_out;
1623 return buf;
1624}
1625
1626int write_sha1_to_fd(int fd, const unsigned char *sha1)
1627{
1628 int retval;
1629 unsigned long objsize;
bb6b8e4f 1630 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
1631
1632 if (buf) {
1633 retval = write_buffer(fd, buf, objsize);
1634 munmap(buf, objsize);
1635 return retval;
1636 }
1637
1638 buf = repack_object(sha1, &objsize);
1639 retval = write_buffer(fd, buf, objsize);
1640 free(buf);
1641 return retval;
a5eda52b
DB
1642}
1643
70b9829e
DB
1644int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1645 size_t bufsize, size_t *bufposn)
8237b185 1646{
230f1322 1647 char tmpfile[PATH_MAX];
8237b185
DB
1648 int local;
1649 z_stream stream;
1650 unsigned char real_sha1[20];
bf0f910d 1651 unsigned char discard[4096];
8237b185
DB
1652 int ret;
1653 SHA_CTX c;
1654
230f1322 1655 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
8237b185 1656
230f1322 1657 local = mkstemp(tmpfile);
8237b185 1658 if (local < 0)
bd2afde8
JH
1659 return error("Couldn't open %s for %s",
1660 tmpfile, sha1_to_hex(sha1));
8237b185
DB
1661
1662 memset(&stream, 0, sizeof(stream));
1663
1664 inflateInit(&stream);
1665
1666 SHA1_Init(&c);
1667
1668 do {
1669 ssize_t size;
70b9829e
DB
1670 if (*bufposn) {
1671 stream.avail_in = *bufposn;
96ad15ae 1672 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
1673 do {
1674 stream.next_out = discard;
1675 stream.avail_out = sizeof(discard);
1676 ret = inflate(&stream, Z_SYNC_FLUSH);
1677 SHA1_Update(&c, discard, sizeof(discard) -
1678 stream.avail_out);
1679 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
1680 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1681 die("unable to write sha1 file");
70b9829e
DB
1682 memmove(buffer, buffer + *bufposn - stream.avail_in,
1683 stream.avail_in);
1684 *bufposn = stream.avail_in;
1685 if (ret != Z_OK)
1686 break;
1687 }
1688 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
1689 if (size <= 0) {
1690 close(local);
230f1322 1691 unlink(tmpfile);
8237b185
DB
1692 if (!size)
1693 return error("Connection closed?");
1694 perror("Reading from connection");
1695 return -1;
1696 }
70b9829e
DB
1697 *bufposn += size;
1698 } while (1);
8237b185
DB
1699 inflateEnd(&stream);
1700
1701 close(local);
1702 SHA1_Final(real_sha1, &c);
1703 if (ret != Z_STREAM_END) {
230f1322 1704 unlink(tmpfile);
8237b185
DB
1705 return error("File %s corrupted", sha1_to_hex(sha1));
1706 }
a89fccd2 1707 if (hashcmp(sha1, real_sha1)) {
230f1322 1708 unlink(tmpfile);
bd2afde8 1709 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 1710 }
230f1322
LT
1711
1712 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
1713}
1714
bf592c50
DB
1715int has_pack_index(const unsigned char *sha1)
1716{
1717 struct stat st;
1718 if (stat(sha1_pack_index_name(sha1), &st))
1719 return 0;
1720 return 1;
1721}
1722
1723int has_pack_file(const unsigned char *sha1)
1724{
1725 struct stat st;
1726 if (stat(sha1_pack_name(sha1), &st))
1727 return 0;
1728 return 1;
1729}
1730
106d710b 1731int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
1732{
1733 struct pack_entry e;
106d710b 1734 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
1735}
1736
8237b185
DB
1737int has_sha1_file(const unsigned char *sha1)
1738{
8237b185 1739 struct stat st;
1f688557
JH
1740 struct pack_entry e;
1741
106d710b 1742 if (find_pack_entry(sha1, &e, NULL))
1f688557 1743 return 1;
ab90ea5d 1744 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 1745}
74400e71 1746
e7332f96
BE
1747/*
1748 * reads from fd as long as possible into a supplied buffer of size bytes.
82e5a82f 1749 * If necessary the buffer's size is increased using realloc()
e7332f96
BE
1750 *
1751 * returns 0 if anything went fine and -1 otherwise
1752 *
1753 * NOTE: both buf and size may change, but even when -1 is returned
1754 * you still have to free() it yourself.
1755 */
1756int read_pipe(int fd, char** return_buf, unsigned long* return_size)
024510c8 1757{
e7332f96
BE
1758 char* buf = *return_buf;
1759 unsigned long size = *return_size;
1760 int iret;
024510c8 1761 unsigned long off = 0;
e7332f96 1762
024510c8 1763 do {
e7332f96 1764 iret = xread(fd, buf + off, size - off);
024510c8
DB
1765 if (iret > 0) {
1766 off += iret;
1767 if (off == size) {
1768 size *= 2;
83572c1a 1769 buf = xrealloc(buf, size);
024510c8
DB
1770 }
1771 }
1772 } while (iret > 0);
e7332f96
BE
1773
1774 *return_buf = buf;
1775 *return_size = off;
1776
1777 if (iret < 0)
1778 return -1;
1779 return 0;
1780}
1781
1782int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1783{
1784 unsigned long size = 4096;
2d7320d0 1785 char *buf = xmalloc(size);
e7332f96 1786 int ret;
e7332f96
BE
1787
1788 if (read_pipe(fd, &buf, &size)) {
024510c8
DB
1789 free(buf);
1790 return -1;
1791 }
e7332f96 1792
024510c8 1793 if (!type)
8e440259 1794 type = blob_type;
024510c8 1795 if (write_object)
e7332f96 1796 ret = write_sha1_file(buf, size, type, sha1);
abdc3fc8
RS
1797 else
1798 ret = hash_sha1_file(buf, size, type, sha1);
024510c8
DB
1799 free(buf);
1800 return ret;
1801}
1802
7672db20 1803int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
74400e71 1804{
74400e71 1805 unsigned long size = st->st_size;
aac17941
LT
1806 void *buf;
1807 int ret;
74400e71 1808
aac17941 1809 buf = "";
74400e71 1810 if (size)
aac17941 1811 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1812 close(fd);
e35f9824 1813 if (buf == MAP_FAILED)
74400e71
JH
1814 return -1;
1815
7672db20 1816 if (!type)
8e440259 1817 type = blob_type;
7672db20
BL
1818 if (write_object)
1819 ret = write_sha1_file(buf, size, type, sha1);
abdc3fc8
RS
1820 else
1821 ret = hash_sha1_file(buf, size, type, sha1);
aac17941
LT
1822 if (size)
1823 munmap(buf, size);
1824 return ret;
74400e71 1825}
ec1fcc16
JH
1826
1827int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1828{
1829 int fd;
1830 char *target;
1831
1832 switch (st->st_mode & S_IFMT) {
1833 case S_IFREG:
1834 fd = open(path, O_RDONLY);
1835 if (fd < 0)
1836 return error("open(\"%s\"): %s", path,
1837 strerror(errno));
1838 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1839 return error("%s: failed to insert into database",
1840 path);
1841 break;
1842 case S_IFLNK:
1843 target = xmalloc(st->st_size+1);
1844 if (readlink(path, target, st->st_size+1) != st->st_size) {
1845 char *errstr = strerror(errno);
1846 free(target);
1847 return error("readlink(\"%s\"): %s", path,
1848 errstr);
1849 }
abdc3fc8
RS
1850 if (!write_object)
1851 hash_sha1_file(target, st->st_size, blob_type, sha1);
1852 else if (write_sha1_file(target, st->st_size, blob_type, sha1))
ec1fcc16
JH
1853 return error("%s: failed to insert into database",
1854 path);
1855 free(target);
1856 break;
1857 default:
1858 return error("%s: unsupported file type", path);
1859 }
1860 return 0;
1861}