remove unnecessary initializations
[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;
466
467 pack_mapped += p->pack_size;
f9253394
JH
468 while (PACK_MAX_SZ < pack_mapped && unuse_one_packed_git())
469 ; /* nothing */
1f688557
JH
470 fd = open(p->pack_name, O_RDONLY);
471 if (fd < 0)
f9253394 472 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
473 if (fstat(fd, &st)) {
474 close(fd);
f9253394 475 die("packfile %s cannot be opened", p->pack_name);
1f688557
JH
476 }
477 if (st.st_size != p->pack_size)
f9253394 478 die("packfile %s size mismatch.", p->pack_name);
1f688557
JH
479 map = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, fd, 0);
480 close(fd);
481 if (map == MAP_FAILED)
f9253394 482 die("packfile %s cannot be mapped.", p->pack_name);
1f688557 483 p->pack_base = map;
f9253394
JH
484
485 /* Check if the pack file matches with the index file.
486 * this is cheap.
487 */
488 if (memcmp((char*)(p->index_base) + p->index_size - 40,
1d7f171c
FF
489 (char *) p->pack_base + p->pack_size - 20,
490 20)) {
491
f9253394 492 die("packfile %s does not match index.", p->pack_name);
bf592c50 493 }
1f688557
JH
494 }
495 p->pack_last_used = pack_used_ctr++;
f9253394 496 p->pack_use_cnt++;
1f688557
JH
497 return 0;
498}
499
9d835df2 500struct packed_git *add_packed_git(char *path, int path_len, int local)
1f688557
JH
501{
502 struct stat st;
503 struct packed_git *p;
504 unsigned long idx_size;
505 void *idx_map;
c0bbbb1b 506 unsigned char sha1[20];
1f688557
JH
507
508 if (check_packed_git_idx(path, &idx_size, &idx_map))
509 return NULL;
510
511 /* do we have a corresponding .pack file? */
512 strcpy(path + path_len - 4, ".pack");
513 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
514 munmap(idx_map, idx_size);
515 return NULL;
516 }
517 /* ok, it looks sane as far as we can check without
518 * actually mapping the pack file.
519 */
520 p = xmalloc(sizeof(*p) + path_len + 2);
521 strcpy(p->pack_name, path);
522 p->index_size = idx_size;
523 p->pack_size = st.st_size;
524 p->index_base = idx_map;
525 p->next = NULL;
d85a4fee 526 p->pack_base = NULL;
1f688557 527 p->pack_last_used = 0;
f9253394 528 p->pack_use_cnt = 0;
9d835df2 529 p->pack_local = local;
f4a11066 530 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
c283ab21 531 memcpy(p->sha1, sha1, 20);
1f688557
JH
532 return p;
533}
534
bf592c50 535struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
536{
537 char *path = sha1_pack_index_name(sha1);
538 return parse_pack_index_file(sha1, path);
539}
540
2ab141a2 541struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
bf592c50
DB
542{
543 struct packed_git *p;
544 unsigned long idx_size;
545 void *idx_map;
c508df5e 546 char *path;
bf592c50 547
c508df5e 548 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
bf592c50
DB
549 return NULL;
550
551 path = sha1_pack_name(sha1);
552
553 p = xmalloc(sizeof(*p) + strlen(path) + 2);
554 strcpy(p->pack_name, path);
555 p->index_size = idx_size;
556 p->pack_size = 0;
557 p->index_base = idx_map;
558 p->next = NULL;
559 p->pack_base = NULL;
560 p->pack_last_used = 0;
561 p->pack_use_cnt = 0;
562 memcpy(p->sha1, sha1, 20);
563 return p;
564}
565
566void install_packed_git(struct packed_git *pack)
567{
568 pack->next = packed_git;
569 packed_git = pack;
570}
571
9d835df2 572static void prepare_packed_git_one(char *objdir, int local)
1f688557
JH
573{
574 char path[PATH_MAX];
575 int len;
576 DIR *dir;
577 struct dirent *de;
578
579 sprintf(path, "%s/pack", objdir);
580 len = strlen(path);
581 dir = opendir(path);
b5b16990 582 if (!dir) {
26125f6b 583 if (errno != ENOENT)
bd2afde8 584 error("unable to open object pack directory: %s: %s",
26125f6b 585 path, strerror(errno));
1f688557 586 return;
b5b16990 587 }
1f688557
JH
588 path[len++] = '/';
589 while ((de = readdir(dir)) != NULL) {
590 int namelen = strlen(de->d_name);
591 struct packed_git *p;
592
5bb1cda5 593 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
594 continue;
595
596 /* we have .idx. Is it a file we can map? */
597 strcpy(path + len, de->d_name);
86f7780c
JK
598 for (p = packed_git; p; p = p->next) {
599 if (!memcmp(path, p->pack_name, len + namelen - 4))
600 break;
601 }
602 if (p)
603 continue;
9d835df2 604 p = add_packed_git(path, len + namelen, local);
1f688557
JH
605 if (!p)
606 continue;
607 p->next = packed_git;
608 packed_git = p;
609 }
5b35bcd5 610 closedir(dir);
1f688557
JH
611}
612
637cdd9d 613static int prepare_packed_git_run_once = 0;
9a217f2a 614void prepare_packed_git(void)
1f688557 615{
d5a63b99 616 struct alternate_object_database *alt;
1f688557 617
637cdd9d 618 if (prepare_packed_git_run_once)
1f688557 619 return;
9d835df2 620 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 621 prepare_alt_odb();
d5a63b99 622 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 623 alt->name[-1] = 0;
9d835df2 624 prepare_packed_git_one(alt->base, 0);
1494e038 625 alt->name[-1] = '/';
1f688557 626 }
637cdd9d
JK
627 prepare_packed_git_run_once = 1;
628}
629
630static void reprepare_packed_git(void)
631{
632 prepare_packed_git_run_once = 0;
633 prepare_packed_git();
1f688557
JH
634}
635
5d6ccf5c 636int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160 637{
d98b46f8 638 char header[100];
0fcfd160
LT
639 unsigned char real_sha1[20];
640 SHA_CTX c;
641
642 SHA1_Init(&c);
d98b46f8 643 SHA1_Update(&c, header, 1+sprintf(header, "%s %lu", type, size));
0fcfd160
LT
644 SHA1_Update(&c, map, size);
645 SHA1_Final(real_sha1, &c);
646 return memcmp(sha1, real_sha1, 20) ? -1 : 0;
647}
648
bb6b8e4f 649void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 650{
0fcfd160
LT
651 struct stat st;
652 void *map;
144bde78 653 int fd;
ace1534d
JH
654 char *filename = find_sha1_file(sha1, &st);
655
656 if (!filename) {
ace1534d
JH
657 return NULL;
658 }
0fcfd160 659
144bde78 660 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 661 if (fd < 0) {
144bde78
LT
662 /* See if it works without O_NOATIME */
663 switch (sha1_file_open_flag) {
664 default:
665 fd = open(filename, O_RDONLY);
666 if (fd >= 0)
667 break;
668 /* Fallthrough */
669 case 0:
144bde78
LT
670 return NULL;
671 }
672
1f688557
JH
673 /* If it failed once, it will probably fail again.
674 * Stop using O_NOATIME
675 */
144bde78 676 sha1_file_open_flag = 0;
0fcfd160 677 }
0fcfd160
LT
678 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
679 close(fd);
e35f9824 680 if (map == MAP_FAILED)
0fcfd160
LT
681 return NULL;
682 *size = st.st_size;
683 return map;
684}
685
bb6b8e4f
JH
686int legacy_loose_object(unsigned char *map)
687{
688 unsigned int word;
689
690 /*
691 * Is it a zlib-compressed buffer? If so, the first byte
692 * must be 0x78 (15-bit window size, deflated), and the
693 * first 16-bit word is evenly divisible by 31
694 */
695 word = (map[0] << 8) + map[1];
696 if (map[0] == 0x78 && !(word % 31))
697 return 1;
698 else
699 return 0;
700}
701
93821bd9 702static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
c4483576 703{
93821bd9 704 unsigned char c;
bb6b8e4f 705 unsigned int bits;
93821bd9
LT
706 unsigned long size;
707 static const char *typename[8] = {
708 NULL, /* OBJ_EXT */
709 "commit", "tree", "blob", "tag",
710 NULL, NULL, NULL
711 };
712 const char *type;
713
c4483576
LT
714 /* Get the data stream */
715 memset(stream, 0, sizeof(*stream));
716 stream->next_in = map;
717 stream->avail_in = mapsize;
718 stream->next_out = buffer;
93821bd9
LT
719 stream->avail_out = bufsiz;
720
bb6b8e4f 721 if (legacy_loose_object(map)) {
93821bd9
LT
722 inflateInit(stream);
723 return inflate(stream, 0);
724 }
725
726 c = *map++;
727 mapsize--;
728 type = typename[(c >> 4) & 7];
729 if (!type)
730 return -1;
c4483576 731
93821bd9
LT
732 bits = 4;
733 size = c & 0xf;
734 while ((c & 0x80)) {
735 if (bits >= 8*sizeof(long))
736 return -1;
737 c = *map++;
738 size += (c & 0x7f) << bits;
739 bits += 7;
740 mapsize--;
741 }
742
743 /* Set up the stream for the rest.. */
744 stream->next_in = map;
745 stream->avail_in = mapsize;
c4483576 746 inflateInit(stream);
93821bd9
LT
747
748 /* And generate the fake traditional header */
749 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu", type, size);
750 return 0;
c4483576
LT
751}
752
6da4016a 753static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
5180cacc
LT
754{
755 int bytes = strlen(buffer) + 1;
d565b341 756 unsigned char *buf = xmalloc(1+size);
93821bd9 757 unsigned long n;
5180cacc 758
93821bd9
LT
759 n = stream->total_out - bytes;
760 if (n > size)
761 n = size;
762 memcpy(buf, (char *) buffer + bytes, n);
763 bytes = n;
5180cacc
LT
764 if (bytes < size) {
765 stream->next_out = buf + bytes;
766 stream->avail_out = size - bytes;
767 while (inflate(stream, Z_FINISH) == Z_OK)
768 /* nothing */;
769 }
770 buf[size] = 0;
771 inflateEnd(stream);
772 return buf;
773}
774
775/*
776 * We used to just use "sscanf()", but that's actually way
777 * too permissive for what we want to check. So do an anal
778 * object header parse by hand.
779 */
38d3874d 780static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
5180cacc
LT
781{
782 int i;
783 unsigned long size;
784
785 /*
786 * The type can be at most ten bytes (including the
787 * terminating '\0' that we add), and is followed by
788 * a space.
789 */
790 i = 10;
791 for (;;) {
792 char c = *hdr++;
793 if (c == ' ')
794 break;
795 if (!--i)
796 return -1;
797 *type++ = c;
798 }
799 *type = 0;
800
801 /*
802 * The length must follow immediately, and be in canonical
803 * decimal format (ie "010" is not valid).
804 */
805 size = *hdr++ - '0';
806 if (size > 9)
807 return -1;
808 if (size) {
809 for (;;) {
810 unsigned long c = *hdr - '0';
811 if (c > 9)
812 break;
813 hdr++;
814 size = size * 10 + c;
815 }
816 }
817 *sizep = size;
818
819 /*
820 * The length must be followed by a zero byte
821 */
822 return *hdr ? -1 : 0;
823}
824
0fcfd160
LT
825void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
826{
5180cacc 827 int ret;
0fcfd160 828 z_stream stream;
5180cacc 829 char hdr[8192];
0fcfd160 830
5180cacc
LT
831 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
832 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
833 return NULL;
834
5180cacc 835 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
836}
837
f3bf9224
JH
838/* forward declaration for a mutually recursive function */
839static int packed_object_info(struct pack_entry *entry,
840 char *type, unsigned long *sizep);
841
5db47c2b
JH
842static int packed_delta_info(unsigned char *base_sha1,
843 unsigned long delta_size,
844 unsigned long left,
845 char *type,
f3bf9224
JH
846 unsigned long *sizep,
847 struct packed_git *p)
5db47c2b 848{
f3bf9224
JH
849 struct pack_entry base_ent;
850
5db47c2b
JH
851 if (left < 20)
852 die("truncated pack file");
5db47c2b 853
f3bf9224
JH
854 /* The base entry _must_ be in the same pack */
855 if (!find_pack_entry_one(base_sha1, &base_ent, p))
856 die("failed to find delta-pack base object %s",
857 sha1_to_hex(base_sha1));
858
c62266f3
JH
859 /* We choose to only get the type of the base object and
860 * ignore potentially corrupt pack file that expects the delta
861 * based on a base with a wrong size. This saves tons of
862 * inflate() calls.
863 */
5db47c2b 864
f3bf9224 865 if (packed_object_info(&base_ent, type, NULL))
c62266f3 866 die("cannot get info for delta-pack base");
5db47c2b 867
c62266f3
JH
868 if (sizep) {
869 const unsigned char *data;
870 unsigned char delta_head[64];
871 unsigned long result_size;
872 z_stream stream;
873 int st;
874
875 memset(&stream, 0, sizeof(stream));
876
877 data = stream.next_in = base_sha1 + 20;
878 stream.avail_in = left - 20;
879 stream.next_out = delta_head;
880 stream.avail_out = sizeof(delta_head);
881
882 inflateInit(&stream);
883 st = inflate(&stream, Z_FINISH);
884 inflateEnd(&stream);
885 if ((st != Z_STREAM_END) &&
886 stream.total_out != sizeof(delta_head))
887 die("delta data unpack-initial failed");
888
889 /* Examine the initial part of the delta to figure out
890 * the result size.
891 */
892 data = delta_head;
8960844a
NP
893
894 /* ignore base size */
895 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
5db47c2b 896
c62266f3 897 /* Read the result size */
8960844a 898 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
c62266f3
JH
899 *sizep = result_size;
900 }
5db47c2b
JH
901 return 0;
902}
903
a733cb60
LT
904static unsigned long unpack_object_header(struct packed_git *p, unsigned long offset,
905 enum object_type *type, unsigned long *sizep)
906{
01247d87 907 unsigned shift;
a733cb60
LT
908 unsigned char *pack, c;
909 unsigned long size;
910
911 if (offset >= p->pack_size)
912 die("object offset outside of pack file");
913
1d7f171c 914 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
915 c = *pack++;
916 offset++;
917 *type = (c >> 4) & 7;
918 size = c & 15;
01247d87 919 shift = 4;
a733cb60
LT
920 while (c & 0x80) {
921 if (offset >= p->pack_size)
922 die("object offset outside of pack file");
923 c = *pack++;
924 offset++;
01247d87
LT
925 size += (c & 0x7f) << shift;
926 shift += 7;
a733cb60
LT
927 }
928 *sizep = size;
929 return offset;
930}
931
a49dd05f
JH
932int check_reuse_pack_delta(struct packed_git *p, unsigned long offset,
933 unsigned char *base, unsigned long *sizep,
934 enum object_type *kindp)
935{
936 unsigned long ptr;
937 int status = -1;
938
939 use_packed_git(p);
940 ptr = offset;
941 ptr = unpack_object_header(p, ptr, kindp, sizep);
942 if (*kindp != OBJ_DELTA)
943 goto done;
1d7f171c 944 memcpy(base, (char *) p->pack_base + ptr, 20);
a49dd05f
JH
945 status = 0;
946 done:
947 unuse_packed_git(p);
948 return status;
949}
950
ad8c80a5
JH
951void packed_object_info_detail(struct pack_entry *e,
952 char *type,
953 unsigned long *size,
954 unsigned long *store_size,
f8f135c9 955 unsigned int *delta_chain_length,
ad8c80a5
JH
956 unsigned char *base_sha1)
957{
958 struct packed_git *p = e->p;
2855d580 959 unsigned long offset;
ad8c80a5
JH
960 unsigned char *pack;
961 enum object_type kind;
962
963 offset = unpack_object_header(p, e->offset, &kind, size);
1d7f171c 964 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
965 if (kind != OBJ_DELTA)
966 *delta_chain_length = 0;
967 else {
f8f135c9 968 unsigned int chain_length = 0;
2855d580
JH
969 if (p->pack_size <= offset + 20)
970 die("pack file %s records an incomplete delta base",
971 p->pack_name);
ad8c80a5
JH
972 memcpy(base_sha1, pack, 20);
973 do {
974 struct pack_entry base_ent;
975 unsigned long junk;
976
977 find_pack_entry_one(pack, &base_ent, p);
978 offset = unpack_object_header(p, base_ent.offset,
979 &kind, &junk);
1d7f171c 980 pack = (unsigned char *) p->pack_base + offset;
ad8c80a5
JH
981 chain_length++;
982 } while (kind == OBJ_DELTA);
983 *delta_chain_length = chain_length;
984 }
985 switch (kind) {
986 case OBJ_COMMIT:
8e440259 987 strcpy(type, commit_type);
ad8c80a5
JH
988 break;
989 case OBJ_TREE:
8e440259 990 strcpy(type, tree_type);
ad8c80a5
JH
991 break;
992 case OBJ_BLOB:
8e440259 993 strcpy(type, blob_type);
ad8c80a5
JH
994 break;
995 case OBJ_TAG:
8e440259 996 strcpy(type, tag_type);
ad8c80a5
JH
997 break;
998 default:
264b16b6
JH
999 die("corrupted pack file %s containing object of kind %d",
1000 p->pack_name, kind);
ad8c80a5
JH
1001 }
1002 *store_size = 0; /* notyet */
1003}
1004
1f688557
JH
1005static int packed_object_info(struct pack_entry *entry,
1006 char *type, unsigned long *sizep)
1007{
1008 struct packed_git *p = entry->p;
1009 unsigned long offset, size, left;
1010 unsigned char *pack;
a733cb60 1011 enum object_type kind;
f9253394 1012 int retval;
5db47c2b
JH
1013
1014 if (use_packed_git(p))
1015 die("cannot map packed file");
1016
a733cb60 1017 offset = unpack_object_header(p, entry->offset, &kind, &size);
1d7f171c 1018 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
1019 left = p->pack_size - offset;
1020
1021 switch (kind) {
1022 case OBJ_DELTA:
f3bf9224 1023 retval = packed_delta_info(pack, size, left, type, sizep, p);
f9253394
JH
1024 unuse_packed_git(p);
1025 return retval;
a733cb60 1026 case OBJ_COMMIT:
8e440259 1027 strcpy(type, commit_type);
1f688557 1028 break;
a733cb60 1029 case OBJ_TREE:
8e440259 1030 strcpy(type, tree_type);
1f688557 1031 break;
a733cb60 1032 case OBJ_BLOB:
8e440259 1033 strcpy(type, blob_type);
1f688557 1034 break;
a733cb60 1035 case OBJ_TAG:
8e440259 1036 strcpy(type, tag_type);
a69d0943 1037 break;
1f688557 1038 default:
264b16b6
JH
1039 die("corrupted pack file %s containing object of kind %d",
1040 p->pack_name, kind);
1f688557 1041 }
c62266f3
JH
1042 if (sizep)
1043 *sizep = size;
f9253394 1044 unuse_packed_git(p);
1f688557
JH
1045 return 0;
1046}
1047
1048/* forward declaration for a mutually recursive function */
1049static void *unpack_entry(struct pack_entry *, char *, unsigned long *);
1050
1051static void *unpack_delta_entry(unsigned char *base_sha1,
1052 unsigned long delta_size,
1053 unsigned long left,
1054 char *type,
f3bf9224
JH
1055 unsigned long *sizep,
1056 struct packed_git *p)
1f688557 1057{
f3bf9224 1058 struct pack_entry base_ent;
1f688557
JH
1059 void *data, *delta_data, *result, *base;
1060 unsigned long data_size, result_size, base_size;
1061 z_stream stream;
1062 int st;
1063
1064 if (left < 20)
1065 die("truncated pack file");
67686d95
JH
1066
1067 /* The base entry _must_ be in the same pack */
1068 if (!find_pack_entry_one(base_sha1, &base_ent, p))
1069 die("failed to find delta-pack base object %s",
1070 sha1_to_hex(base_sha1));
1071 base = unpack_entry_gently(&base_ent, type, &base_size);
1072 if (!base)
1073 die("failed to read delta-pack base object %s",
1074 sha1_to_hex(base_sha1));
1075
1f688557
JH
1076 data = base_sha1 + 20;
1077 data_size = left - 20;
1078 delta_data = xmalloc(delta_size);
1079
1080 memset(&stream, 0, sizeof(stream));
1081
1082 stream.next_in = data;
1083 stream.avail_in = data_size;
1084 stream.next_out = delta_data;
1085 stream.avail_out = delta_size;
1086
1087 inflateInit(&stream);
1088 st = inflate(&stream, Z_FINISH);
1089 inflateEnd(&stream);
1090 if ((st != Z_STREAM_END) || stream.total_out != delta_size)
1091 die("delta data unpack failed");
1092
1f688557
JH
1093 result = patch_delta(base, base_size,
1094 delta_data, delta_size,
1095 &result_size);
1096 if (!result)
1097 die("failed to apply delta");
1098 free(delta_data);
1099 free(base);
1100 *sizep = result_size;
1101 return result;
1102}
1103
1104static void *unpack_non_delta_entry(unsigned char *data,
1105 unsigned long size,
1106 unsigned long left)
1107{
1108 int st;
1109 z_stream stream;
4d235c80 1110 unsigned char *buffer;
1f688557
JH
1111
1112 buffer = xmalloc(size + 1);
1113 buffer[size] = 0;
1114 memset(&stream, 0, sizeof(stream));
1115 stream.next_in = data;
1116 stream.avail_in = left;
1117 stream.next_out = buffer;
1118 stream.avail_out = size;
1119
1120 inflateInit(&stream);
1121 st = inflate(&stream, Z_FINISH);
1122 inflateEnd(&stream);
1123 if ((st != Z_STREAM_END) || stream.total_out != size) {
1124 free(buffer);
1125 return NULL;
1126 }
1127
1128 return buffer;
1129}
1130
1131static void *unpack_entry(struct pack_entry *entry,
1132 char *type, unsigned long *sizep)
1133{
1134 struct packed_git *p = entry->p;
f9253394 1135 void *retval;
1f688557
JH
1136
1137 if (use_packed_git(p))
1138 die("cannot map packed file");
f3bf9224
JH
1139 retval = unpack_entry_gently(entry, type, sizep);
1140 unuse_packed_git(p);
1141 if (!retval)
264b16b6 1142 die("corrupted pack file %s", p->pack_name);
f3bf9224
JH
1143 return retval;
1144}
1145
1146/* The caller is responsible for use_packed_git()/unuse_packed_git() pair */
1147void *unpack_entry_gently(struct pack_entry *entry,
1148 char *type, unsigned long *sizep)
1149{
1150 struct packed_git *p = entry->p;
1151 unsigned long offset, size, left;
1152 unsigned char *pack;
1153 enum object_type kind;
1154 void *retval;
1f688557 1155
a733cb60 1156 offset = unpack_object_header(p, entry->offset, &kind, &size);
1d7f171c 1157 pack = (unsigned char *) p->pack_base + offset;
a733cb60
LT
1158 left = p->pack_size - offset;
1159 switch (kind) {
1160 case OBJ_DELTA:
f3bf9224 1161 retval = unpack_delta_entry(pack, size, left, type, sizep, p);
f9253394 1162 return retval;
a733cb60 1163 case OBJ_COMMIT:
8e440259 1164 strcpy(type, commit_type);
1f688557 1165 break;
a733cb60 1166 case OBJ_TREE:
8e440259 1167 strcpy(type, tree_type);
1f688557 1168 break;
a733cb60 1169 case OBJ_BLOB:
8e440259 1170 strcpy(type, blob_type);
1f688557 1171 break;
a733cb60 1172 case OBJ_TAG:
8e440259 1173 strcpy(type, tag_type);
a69d0943 1174 break;
1f688557 1175 default:
f3bf9224 1176 return NULL;
1f688557
JH
1177 }
1178 *sizep = size;
f9253394 1179 retval = unpack_non_delta_entry(pack, size, left);
f9253394 1180 return retval;
1f688557
JH
1181}
1182
9a217f2a
JH
1183int num_packed_objects(const struct packed_git *p)
1184{
f9253394 1185 /* See check_packed_git_idx() */
9a217f2a
JH
1186 return (p->index_size - 20 - 20 - 4*256) / 24;
1187}
1188
1189int nth_packed_object_sha1(const struct packed_git *p, int n,
1190 unsigned char* sha1)
1191{
1192 void *index = p->index_base + 256;
1193 if (n < 0 || num_packed_objects(p) <= n)
1194 return -1;
1d7f171c 1195 memcpy(sha1, (char *) index + (24 * n) + 4, 20);
9a217f2a
JH
1196 return 0;
1197}
1198
f3bf9224
JH
1199int find_pack_entry_one(const unsigned char *sha1,
1200 struct pack_entry *e, struct packed_git *p)
1f688557 1201{
4d235c80 1202 unsigned int *level1_ofs = p->index_base;
1f688557
JH
1203 int hi = ntohl(level1_ofs[*sha1]);
1204 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1205 void *index = p->index_base + 256;
1206
1207 do {
1208 int mi = (lo + hi) / 2;
1d7f171c 1209 int cmp = memcmp((char *) index + (24 * mi) + 4, sha1, 20);
1f688557 1210 if (!cmp) {
1d7f171c 1211 e->offset = ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1f688557
JH
1212 memcpy(e->sha1, sha1, 20);
1213 e->p = p;
1214 return 1;
1215 }
1216 if (cmp > 0)
1217 hi = mi;
1218 else
1219 lo = mi+1;
1220 } while (lo < hi);
1221 return 0;
1222}
1223
1224static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1225{
1226 struct packed_git *p;
1227 prepare_packed_git();
1228
1229 for (p = packed_git; p; p = p->next) {
f3bf9224 1230 if (find_pack_entry_one(sha1, e, p))
1f688557
JH
1231 return 1;
1232 }
1233 return 0;
1234}
1235
bf592c50
DB
1236struct packed_git *find_sha1_pack(const unsigned char *sha1,
1237 struct packed_git *packs)
1238{
1239 struct packed_git *p;
1240 struct pack_entry e;
1241
1242 for (p = packs; p; p = p->next) {
1243 if (find_pack_entry_one(sha1, &e, p))
1244 return p;
1245 }
1246 return NULL;
1247
1248}
1249
36e4d74a 1250int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1251{
36e4d74a 1252 int status;
65c2e0c3
JH
1253 unsigned long mapsize, size;
1254 void *map;
1255 z_stream stream;
36e4d74a 1256 char hdr[128];
65c2e0c3 1257
bb6b8e4f 1258 map = map_sha1_file(sha1, &mapsize);
1f688557
JH
1259 if (!map) {
1260 struct pack_entry e;
1261
637cdd9d
JK
1262 if (find_pack_entry(sha1, &e))
1263 return packed_object_info(&e, type, sizep);
1264 reprepare_packed_git();
1265 if (find_pack_entry(sha1, &e))
1266 return packed_object_info(&e, type, sizep);
1267 return error("unable to find %s", sha1_to_hex(sha1));
1f688557 1268 }
36e4d74a
JH
1269 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1270 status = error("unable to unpack %s header",
1271 sha1_to_hex(sha1));
1272 if (parse_sha1_header(hdr, type, &size) < 0)
1273 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1274 else {
65c2e0c3 1275 status = 0;
c62266f3
JH
1276 if (sizep)
1277 *sizep = size;
65c2e0c3 1278 }
65c2e0c3
JH
1279 inflateEnd(&stream);
1280 munmap(map, mapsize);
1281 return status;
1282}
1283
1f688557
JH
1284static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1285{
1286 struct pack_entry e;
1287
1288 if (!find_pack_entry(sha1, &e)) {
1289 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1290 return NULL;
1291 }
1292 return unpack_entry(&e, type, size);
1293}
1294
0fcfd160
LT
1295void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1296{
1297 unsigned long mapsize;
1298 void *map, *buf;
ab90ea5d 1299 struct pack_entry e;
0fcfd160 1300
ab90ea5d
JH
1301 if (find_pack_entry(sha1, &e))
1302 return read_packed_sha1(sha1, type, size);
bb6b8e4f 1303 map = map_sha1_file(sha1, &mapsize);
0fcfd160
LT
1304 if (map) {
1305 buf = unpack_sha1_file(map, mapsize, type, size);
1306 munmap(map, mapsize);
1307 return buf;
1308 }
637cdd9d
JK
1309 reprepare_packed_git();
1310 if (find_pack_entry(sha1, &e))
1311 return read_packed_sha1(sha1, type, size);
ab90ea5d 1312 return NULL;
0fcfd160
LT
1313}
1314
40469ee9 1315void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1316 const char *required_type,
40469ee9
JH
1317 unsigned long *size,
1318 unsigned char *actual_sha1_return)
f4913f91
JH
1319{
1320 char type[20];
1321 void *buffer;
1322 unsigned long isize;
40469ee9 1323 unsigned char actual_sha1[20];
f4913f91 1324
40469ee9
JH
1325 memcpy(actual_sha1, sha1, 20);
1326 while (1) {
1327 int ref_length = -1;
1328 const char *ref_type = NULL;
f4913f91 1329
40469ee9
JH
1330 buffer = read_sha1_file(actual_sha1, type, &isize);
1331 if (!buffer)
1332 return NULL;
1333 if (!strcmp(type, required_type)) {
1334 *size = isize;
1335 if (actual_sha1_return)
1336 memcpy(actual_sha1_return, actual_sha1, 20);
1337 return buffer;
1338 }
1339 /* Handle references */
8e440259 1340 else if (!strcmp(type, commit_type))
40469ee9 1341 ref_type = "tree ";
8e440259 1342 else if (!strcmp(type, tag_type))
40469ee9
JH
1343 ref_type = "object ";
1344 else {
1345 free(buffer);
1346 return NULL;
1347 }
1348 ref_length = strlen(ref_type);
f4913f91 1349
40469ee9 1350 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1351 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1352 free(buffer);
1353 return NULL;
1354 }
1cf58e72 1355 free(buffer);
40469ee9
JH
1356 /* Now we have the ID of the referred-to object in
1357 * actual_sha1. Check again. */
f4913f91 1358 }
f4913f91
JH
1359}
1360
7672db20
BL
1361char *write_sha1_file_prepare(void *buf,
1362 unsigned long len,
1363 const char *type,
1364 unsigned char *sha1,
1365 unsigned char *hdr,
1366 int *hdrlen)
d410c0f5
JH
1367{
1368 SHA_CTX c;
1369
1370 /* Generate the header */
1371 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1372
1373 /* Sha1.. */
1374 SHA1_Init(&c);
1375 SHA1_Update(&c, hdr, *hdrlen);
1376 SHA1_Update(&c, buf, len);
1377 SHA1_Final(sha1, &c);
1378
1379 return sha1_file_name(sha1);
1380}
1381
230f1322
LT
1382/*
1383 * Link the tempfile to the final place, possibly creating the
1384 * last directory level as you do so.
1385 *
1386 * Returns the errno on failure, 0 on success.
1387 */
1388static int link_temp_to_file(const char *tmpfile, char *filename)
1389{
1390 int ret;
756aaf4a 1391 char *dir;
230f1322
LT
1392
1393 if (!link(tmpfile, filename))
1394 return 0;
1395
1396 /*
756aaf4a 1397 * Try to mkdir the last path component if that failed.
230f1322
LT
1398 *
1399 * Re-try the "link()" regardless of whether the mkdir
1400 * succeeds, since a race might mean that somebody
1401 * else succeeded.
1402 */
1403 ret = errno;
756aaf4a
SP
1404 dir = strrchr(filename, '/');
1405 if (dir) {
1406 *dir = 0;
1407 mkdir(filename, 0777);
1408 if (adjust_shared_perm(filename))
1409 return -2;
1410 *dir = '/';
1411 if (!link(tmpfile, filename))
1412 return 0;
1413 ret = errno;
230f1322
LT
1414 }
1415 return ret;
1416}
1417
1418/*
1419 * Move the just written object into its final resting place
1420 */
b721e01f 1421int move_temp_to_file(const char *tmpfile, char *filename)
230f1322
LT
1422{
1423 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
1424
1425 /*
1426 * Coda hack - coda doesn't like cross-directory links,
1427 * so we fall back to a rename, which will mean that it
1428 * won't be able to check collisions, but that's not a
1429 * big deal.
1430 *
1431 * The same holds for FAT formatted media.
1432 *
1433 * When this succeeds, we just return 0. We have nothing
1434 * left to unlink.
1435 */
1436 if (ret && ret != EEXIST) {
1437 if (!rename(tmpfile, filename))
230f1322 1438 return 0;
9e48b389 1439 ret = errno;
230f1322
LT
1440 }
1441 unlink(tmpfile);
1442 if (ret) {
1443 if (ret != EEXIST) {
7246ed43 1444 fprintf(stderr, "unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
1445 return -1;
1446 }
1447 /* FIXME!!! Collision check here ? */
1448 }
1449
1450 return 0;
1451}
1452
4d548150
LT
1453static int write_buffer(int fd, const void *buf, size_t len)
1454{
1455 while (len) {
1456 ssize_t size;
1457
1458 size = write(fd, buf, len);
1459 if (!size)
1460 return error("file write: disk full");
1461 if (size < 0) {
1462 if (errno == EINTR || errno == EAGAIN)
1463 continue;
1464 return error("file write error (%s)", strerror(errno));
1465 }
1466 len -= size;
1d7f171c 1467 buf = (char *) buf + size;
4d548150
LT
1468 }
1469 return 0;
1470}
1471
93821bd9
LT
1472static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1473{
1474 int hdr_len;
1475 unsigned char c;
1476
1477 c = (type << 4) | (len & 15);
1478 len >>= 4;
1479 hdr_len = 1;
1480 while (len) {
1481 *hdr++ = c | 0x80;
1482 hdr_len++;
1483 c = (len & 0x7f);
1484 len >>= 7;
1485 }
1486 *hdr = c;
1487 return hdr_len;
1488}
1489
1490static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1491{
1492 int obj_type, hdr;
1493
1494 if (use_legacy_headers) {
1495 while (deflate(stream, 0) == Z_OK)
1496 /* nothing */;
1497 return;
1498 }
1499 if (!strcmp(type, blob_type))
1500 obj_type = OBJ_BLOB;
1501 else if (!strcmp(type, tree_type))
1502 obj_type = OBJ_TREE;
1503 else if (!strcmp(type, commit_type))
1504 obj_type = OBJ_COMMIT;
1505 else if (!strcmp(type, tag_type))
1506 obj_type = OBJ_TAG;
1507 else
1508 die("trying to generate bogus object of type '%s'", type);
1509 hdr = write_binary_header(stream->next_out, obj_type, len);
1510 stream->total_out = hdr;
1511 stream->next_out += hdr;
1512 stream->avail_out -= hdr;
1513}
1514
bf0f910d 1515int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1516{
1517 int size;
bf0f910d 1518 unsigned char *compressed;
0fcfd160
LT
1519 z_stream stream;
1520 unsigned char sha1[20];
706bc531 1521 char *filename;
aac17941 1522 static char tmpfile[PATH_MAX];
bf0f910d 1523 unsigned char hdr[50];
230f1322 1524 int fd, hdrlen;
a44c9a5e 1525
d410c0f5
JH
1526 /* Normally if we have it in the pack then we do not bother writing
1527 * it out into .git/objects/??/?{38} file.
1528 */
1529 filename = write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
706bc531
LT
1530 if (returnsha1)
1531 memcpy(returnsha1, sha1, 20);
d410c0f5
JH
1532 if (has_sha1_file(sha1))
1533 return 0;
aac17941
LT
1534 fd = open(filename, O_RDONLY);
1535 if (fd >= 0) {
706bc531 1536 /*
aac17941
LT
1537 * FIXME!!! We might do collision checking here, but we'd
1538 * need to uncompress the old file and check it. Later.
706bc531 1539 */
aac17941 1540 close(fd);
706bc531
LT
1541 return 0;
1542 }
1543
aac17941 1544 if (errno != ENOENT) {
7246ed43 1545 fprintf(stderr, "sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
1546 return -1;
1547 }
1548
1549 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1550
aac17941
LT
1551 fd = mkstemp(tmpfile);
1552 if (fd < 0) {
7246ed43 1553 fprintf(stderr, "unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
1554 return -1;
1555 }
1556
0fcfd160
LT
1557 /* Set it up */
1558 memset(&stream, 0, sizeof(stream));
12f6c308 1559 deflateInit(&stream, zlib_compression_level);
93821bd9 1560 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 1561 compressed = xmalloc(size);
0fcfd160
LT
1562
1563 /* Compress it */
0fcfd160
LT
1564 stream.next_out = compressed;
1565 stream.avail_out = size;
a44c9a5e
LT
1566
1567 /* First header.. */
1568 stream.next_in = hdr;
1569 stream.avail_in = hdrlen;
93821bd9 1570 setup_object_header(&stream, type, len);
a44c9a5e
LT
1571
1572 /* Then the data itself.. */
1573 stream.next_in = buf;
1574 stream.avail_in = len;
0fcfd160
LT
1575 while (deflate(&stream, Z_FINISH) == Z_OK)
1576 /* nothing */;
1577 deflateEnd(&stream);
1578 size = stream.total_out;
1579
4d548150
LT
1580 if (write_buffer(fd, compressed, size) < 0)
1581 die("unable to write sha1 file");
aac17941 1582 fchmod(fd, 0444);
706bc531 1583 close(fd);
383f85b7 1584 free(compressed);
0fcfd160 1585
230f1322 1586 return move_temp_to_file(tmpfile, filename);
0fcfd160 1587}
8237b185 1588
4d548150
LT
1589/*
1590 * We need to unpack and recompress the object for writing
1591 * it out to a different file.
1592 */
1593static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 1594{
4d548150 1595 size_t size;
a5eda52b 1596 z_stream stream;
4d548150
LT
1597 unsigned char *unpacked;
1598 unsigned long len;
1599 char type[20];
1600 char hdr[50];
1601 int hdrlen;
1602 void *buf;
bfc66daf 1603
a9486b02 1604 /* need to unpack and recompress it by itself */
4d548150 1605 unpacked = read_packed_sha1(sha1, type, &len);
a5eda52b 1606
4d548150 1607 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
a5eda52b 1608
4d548150
LT
1609 /* Set it up */
1610 memset(&stream, 0, sizeof(stream));
12f6c308 1611 deflateInit(&stream, zlib_compression_level);
4d548150
LT
1612 size = deflateBound(&stream, len + hdrlen);
1613 buf = xmalloc(size);
a5eda52b 1614
4d548150
LT
1615 /* Compress it */
1616 stream.next_out = buf;
1617 stream.avail_out = size;
a5eda52b 1618
4d548150
LT
1619 /* First header.. */
1620 stream.next_in = (void *)hdr;
1621 stream.avail_in = hdrlen;
1622 while (deflate(&stream, 0) == Z_OK)
1623 /* nothing */;
bfc66daf 1624
4d548150
LT
1625 /* Then the data itself.. */
1626 stream.next_in = unpacked;
1627 stream.avail_in = len;
1628 while (deflate(&stream, Z_FINISH) == Z_OK)
1629 /* nothing */;
1630 deflateEnd(&stream);
1631 free(unpacked);
bfc66daf 1632
4d548150
LT
1633 *objsize = stream.total_out;
1634 return buf;
1635}
1636
1637int write_sha1_to_fd(int fd, const unsigned char *sha1)
1638{
1639 int retval;
1640 unsigned long objsize;
bb6b8e4f 1641 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
1642
1643 if (buf) {
1644 retval = write_buffer(fd, buf, objsize);
1645 munmap(buf, objsize);
1646 return retval;
1647 }
1648
1649 buf = repack_object(sha1, &objsize);
1650 retval = write_buffer(fd, buf, objsize);
1651 free(buf);
1652 return retval;
a5eda52b
DB
1653}
1654
70b9829e
DB
1655int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1656 size_t bufsize, size_t *bufposn)
8237b185 1657{
230f1322 1658 char tmpfile[PATH_MAX];
8237b185
DB
1659 int local;
1660 z_stream stream;
1661 unsigned char real_sha1[20];
bf0f910d 1662 unsigned char discard[4096];
8237b185
DB
1663 int ret;
1664 SHA_CTX c;
1665
230f1322 1666 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
8237b185 1667
230f1322 1668 local = mkstemp(tmpfile);
8237b185 1669 if (local < 0)
bd2afde8
JH
1670 return error("Couldn't open %s for %s",
1671 tmpfile, sha1_to_hex(sha1));
8237b185
DB
1672
1673 memset(&stream, 0, sizeof(stream));
1674
1675 inflateInit(&stream);
1676
1677 SHA1_Init(&c);
1678
1679 do {
1680 ssize_t size;
70b9829e
DB
1681 if (*bufposn) {
1682 stream.avail_in = *bufposn;
96ad15ae 1683 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
1684 do {
1685 stream.next_out = discard;
1686 stream.avail_out = sizeof(discard);
1687 ret = inflate(&stream, Z_SYNC_FLUSH);
1688 SHA1_Update(&c, discard, sizeof(discard) -
1689 stream.avail_out);
1690 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
1691 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1692 die("unable to write sha1 file");
70b9829e
DB
1693 memmove(buffer, buffer + *bufposn - stream.avail_in,
1694 stream.avail_in);
1695 *bufposn = stream.avail_in;
1696 if (ret != Z_OK)
1697 break;
1698 }
1699 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
1700 if (size <= 0) {
1701 close(local);
230f1322 1702 unlink(tmpfile);
8237b185
DB
1703 if (!size)
1704 return error("Connection closed?");
1705 perror("Reading from connection");
1706 return -1;
1707 }
70b9829e
DB
1708 *bufposn += size;
1709 } while (1);
8237b185
DB
1710 inflateEnd(&stream);
1711
1712 close(local);
1713 SHA1_Final(real_sha1, &c);
1714 if (ret != Z_STREAM_END) {
230f1322 1715 unlink(tmpfile);
8237b185
DB
1716 return error("File %s corrupted", sha1_to_hex(sha1));
1717 }
1718 if (memcmp(sha1, real_sha1, 20)) {
230f1322 1719 unlink(tmpfile);
bd2afde8 1720 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 1721 }
230f1322
LT
1722
1723 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
1724}
1725
bf592c50
DB
1726int has_pack_index(const unsigned char *sha1)
1727{
1728 struct stat st;
1729 if (stat(sha1_pack_index_name(sha1), &st))
1730 return 0;
1731 return 1;
1732}
1733
1734int has_pack_file(const unsigned char *sha1)
1735{
1736 struct stat st;
1737 if (stat(sha1_pack_name(sha1), &st))
1738 return 0;
1739 return 1;
1740}
1741
dade09c2
LT
1742int has_sha1_pack(const unsigned char *sha1)
1743{
1744 struct pack_entry e;
1745 return find_pack_entry(sha1, &e);
1746}
1747
8237b185
DB
1748int has_sha1_file(const unsigned char *sha1)
1749{
8237b185 1750 struct stat st;
1f688557
JH
1751 struct pack_entry e;
1752
ab90ea5d 1753 if (find_pack_entry(sha1, &e))
1f688557 1754 return 1;
ab90ea5d 1755 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 1756}
74400e71 1757
e7332f96
BE
1758/*
1759 * reads from fd as long as possible into a supplied buffer of size bytes.
82e5a82f 1760 * If necessary the buffer's size is increased using realloc()
e7332f96
BE
1761 *
1762 * returns 0 if anything went fine and -1 otherwise
1763 *
1764 * NOTE: both buf and size may change, but even when -1 is returned
1765 * you still have to free() it yourself.
1766 */
1767int read_pipe(int fd, char** return_buf, unsigned long* return_size)
024510c8 1768{
e7332f96
BE
1769 char* buf = *return_buf;
1770 unsigned long size = *return_size;
1771 int iret;
024510c8 1772 unsigned long off = 0;
e7332f96 1773
024510c8 1774 do {
e7332f96 1775 iret = xread(fd, buf + off, size - off);
024510c8
DB
1776 if (iret > 0) {
1777 off += iret;
1778 if (off == size) {
1779 size *= 2;
1780 buf = realloc(buf, size);
1781 }
1782 }
1783 } while (iret > 0);
e7332f96
BE
1784
1785 *return_buf = buf;
1786 *return_size = off;
1787
1788 if (iret < 0)
1789 return -1;
1790 return 0;
1791}
1792
1793int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1794{
1795 unsigned long size = 4096;
1796 char *buf = malloc(size);
1797 int ret;
1798 unsigned char hdr[50];
1799 int hdrlen;
1800
1801 if (read_pipe(fd, &buf, &size)) {
024510c8
DB
1802 free(buf);
1803 return -1;
1804 }
e7332f96 1805
024510c8 1806 if (!type)
8e440259 1807 type = blob_type;
024510c8 1808 if (write_object)
e7332f96 1809 ret = write_sha1_file(buf, size, type, sha1);
024510c8 1810 else {
e7332f96 1811 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
024510c8
DB
1812 ret = 0;
1813 }
1814 free(buf);
1815 return ret;
1816}
1817
7672db20 1818int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
74400e71 1819{
74400e71 1820 unsigned long size = st->st_size;
aac17941
LT
1821 void *buf;
1822 int ret;
7672db20
BL
1823 unsigned char hdr[50];
1824 int hdrlen;
74400e71 1825
aac17941 1826 buf = "";
74400e71 1827 if (size)
aac17941 1828 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1829 close(fd);
e35f9824 1830 if (buf == MAP_FAILED)
74400e71
JH
1831 return -1;
1832
7672db20 1833 if (!type)
8e440259 1834 type = blob_type;
7672db20
BL
1835 if (write_object)
1836 ret = write_sha1_file(buf, size, type, sha1);
1837 else {
1838 write_sha1_file_prepare(buf, size, type, sha1, hdr, &hdrlen);
1839 ret = 0;
1840 }
aac17941
LT
1841 if (size)
1842 munmap(buf, size);
1843 return ret;
74400e71 1844}
ec1fcc16
JH
1845
1846int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1847{
1848 int fd;
1849 char *target;
1850
1851 switch (st->st_mode & S_IFMT) {
1852 case S_IFREG:
1853 fd = open(path, O_RDONLY);
1854 if (fd < 0)
1855 return error("open(\"%s\"): %s", path,
1856 strerror(errno));
1857 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1858 return error("%s: failed to insert into database",
1859 path);
1860 break;
1861 case S_IFLNK:
1862 target = xmalloc(st->st_size+1);
1863 if (readlink(path, target, st->st_size+1) != st->st_size) {
1864 char *errstr = strerror(errno);
1865 free(target);
1866 return error("readlink(\"%s\"): %s", path,
1867 errstr);
1868 }
1869 if (!write_object) {
1870 unsigned char hdr[50];
1871 int hdrlen;
8e440259 1872 write_sha1_file_prepare(target, st->st_size, blob_type,
ec1fcc16 1873 sha1, hdr, &hdrlen);
8e440259 1874 } else if (write_sha1_file(target, st->st_size, blob_type, sha1))
ec1fcc16
JH
1875 return error("%s: failed to insert into database",
1876 path);
1877 free(target);
1878 break;
1879 default:
1880 return error("%s: unsupported file type", path);
1881 }
1882 return 0;
1883}