Replace use_packed_git with window cursors.
[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
400static int pack_used_ctr;
401static unsigned long pack_mapped;
9a217f2a 402struct packed_git *packed_git;
1f688557 403
1f688557
JH
404static int check_packed_git_idx(const char *path, unsigned long *idx_size_,
405 void **idx_map_)
406{
407 void *idx_map;
408 unsigned int *index;
409 unsigned long idx_size;
410 int nr, i;
e93ec6f9 411 int fd = open(path, O_RDONLY);
1f688557
JH
412 struct stat st;
413 if (fd < 0)
414 return -1;
415 if (fstat(fd, &st)) {
416 close(fd);
417 return -1;
418 }
419 idx_size = st.st_size;
420 idx_map = mmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
421 close(fd);
422 if (idx_map == MAP_FAILED)
423 return -1;
424
425 index = idx_map;
4d235c80
LT
426 *idx_map_ = idx_map;
427 *idx_size_ = idx_size;
1f688557
JH
428
429 /* check index map */
f9253394 430 if (idx_size < 4*256 + 20 + 20)
1f688557
JH
431 return error("index file too small");
432 nr = 0;
433 for (i = 0; i < 256; i++) {
434 unsigned int n = ntohl(index[i]);
435 if (n < nr)
436 return error("non-monotonic index");
437 nr = n;
438 }
439
440 /*
441 * Total size:
442 * - 256 index entries 4 bytes each
443 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
444 * - 20-byte SHA1 of the packfile
445 * - 20-byte SHA1 file checksum
446 */
447 if (idx_size != 4*256 + nr * 24 + 20 + 20)
448 return error("wrong index file size");
449
1f688557
JH
450 return 0;
451}
452
f9253394 453static int unuse_one_packed_git(void)
1f688557 454{
f9253394
JH
455 struct packed_git *p, *lru = NULL;
456
457 for (p = packed_git; p; p = p->next) {
c41ee586 458 if (!p->windows || p->windows->inuse_cnt)
f9253394 459 continue;
c41ee586 460 if (!lru || p->windows->last_used < lru->windows->last_used)
f9253394
JH
461 lru = p;
462 }
463 if (!lru)
464 return 0;
c41ee586
SP
465 munmap(lru->windows->base, lru->windows->len);
466 free(lru->windows);
467 lru->windows = NULL;
9bc879c1
SP
468 close(p->pack_fd);
469 p->pack_fd = -1;
f9253394
JH
470 return 1;
471}
472
03e79c88 473void unuse_pack(struct pack_window **w_cursor)
f9253394 474{
03e79c88
SP
475 struct pack_window *w = *w_cursor;
476 if (w) {
477 w->inuse_cnt--;
478 *w_cursor = NULL;
479 }
1f688557
JH
480}
481
9bc879c1 482static void open_packed_git(struct packed_git *p)
1f688557 483{
9bc879c1
SP
484 struct stat st;
485 struct pack_header hdr;
486 unsigned char sha1[20];
487 unsigned char *idx_sha1;
488
489 p->pack_fd = open(p->pack_name, O_RDONLY);
490 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
491 die("packfile %s cannot be opened", p->pack_name);
492
493 /* If we created the struct before we had the pack we lack size. */
bf592c50 494 if (!p->pack_size) {
bf592c50
DB
495 if (!S_ISREG(st.st_mode))
496 die("packfile %s not a regular file", p->pack_name);
497 p->pack_size = st.st_size;
9bc879c1
SP
498 } else if (p->pack_size != st.st_size)
499 die("packfile %s size changed", p->pack_name);
500
501 /* Verify we recognize this pack file format. */
502 read_or_die(p->pack_fd, &hdr, sizeof(hdr));
503 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
504 die("file %s is not a GIT packfile", p->pack_name);
505 if (!pack_version_ok(hdr.hdr_version))
506 die("packfile %s is version %u and not supported"
507 " (try upgrading GIT to a newer version)",
508 p->pack_name, ntohl(hdr.hdr_version));
509
510 /* Verify the pack matches its index. */
511 if (num_packed_objects(p) != ntohl(hdr.hdr_entries))
512 die("packfile %s claims to have %u objects"
513 " while index size indicates %u objects",
514 p->pack_name, ntohl(hdr.hdr_entries),
515 num_packed_objects(p));
516 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
517 die("end of packfile %s is unavailable", p->pack_name);
518 read_or_die(p->pack_fd, sha1, sizeof(sha1));
519 idx_sha1 = ((unsigned char *)p->index_base) + p->index_size - 40;
520 if (hashcmp(sha1, idx_sha1))
521 die("packfile %s does not match index", p->pack_name);
522}
523
03e79c88
SP
524unsigned char* use_pack(struct packed_git *p,
525 struct pack_window **w_cursor,
526 unsigned long offset,
527 unsigned int *left)
9bc879c1 528{
03e79c88
SP
529 struct pack_window *win = p->windows;
530
9bc879c1
SP
531 if (p->pack_fd == -1)
532 open_packed_git(p);
03e79c88 533 if (!win) {
1f688557 534 pack_mapped += p->pack_size;
77ccc5bb 535 while (packed_git_limit < pack_mapped && unuse_one_packed_git())
f9253394 536 ; /* nothing */
c41ee586
SP
537 win = xcalloc(1, sizeof(*win));
538 win->len = p->pack_size;
9bc879c1 539 win->base = mmap(NULL, p->pack_size, PROT_READ, MAP_PRIVATE, p->pack_fd, 0);
c41ee586 540 if (win->base == MAP_FAILED)
f9253394 541 die("packfile %s cannot be mapped.", p->pack_name);
c41ee586 542 p->windows = win;
1f688557 543 }
03e79c88
SP
544 if (win != *w_cursor) {
545 win->last_used = pack_used_ctr++;
546 win->inuse_cnt++;
547 *w_cursor = win;
548 }
549 if (left)
550 *left = win->len - offset;
551 return win->base + offset;
1f688557
JH
552}
553
9d835df2 554struct packed_git *add_packed_git(char *path, int path_len, int local)
1f688557
JH
555{
556 struct stat st;
557 struct packed_git *p;
558 unsigned long idx_size;
559 void *idx_map;
c0bbbb1b 560 unsigned char sha1[20];
1f688557
JH
561
562 if (check_packed_git_idx(path, &idx_size, &idx_map))
563 return NULL;
564
565 /* do we have a corresponding .pack file? */
566 strcpy(path + path_len - 4, ".pack");
567 if (stat(path, &st) || !S_ISREG(st.st_mode)) {
568 munmap(idx_map, idx_size);
569 return NULL;
570 }
571 /* ok, it looks sane as far as we can check without
572 * actually mapping the pack file.
573 */
574 p = xmalloc(sizeof(*p) + path_len + 2);
575 strcpy(p->pack_name, path);
576 p->index_size = idx_size;
577 p->pack_size = st.st_size;
578 p->index_base = idx_map;
579 p->next = NULL;
c41ee586 580 p->windows = NULL;
9bc879c1 581 p->pack_fd = -1;
9d835df2 582 p->pack_local = local;
f4a11066 583 if ((path_len > 44) && !get_sha1_hex(path + path_len - 44, sha1))
e702496e 584 hashcpy(p->sha1, sha1);
1f688557
JH
585 return p;
586}
587
bf592c50 588struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
589{
590 char *path = sha1_pack_index_name(sha1);
591 return parse_pack_index_file(sha1, path);
592}
593
2ab141a2 594struct packed_git *parse_pack_index_file(const unsigned char *sha1, char *idx_path)
bf592c50
DB
595{
596 struct packed_git *p;
597 unsigned long idx_size;
598 void *idx_map;
c508df5e 599 char *path;
bf592c50 600
c508df5e 601 if (check_packed_git_idx(idx_path, &idx_size, &idx_map))
bf592c50
DB
602 return NULL;
603
604 path = sha1_pack_name(sha1);
605
606 p = xmalloc(sizeof(*p) + strlen(path) + 2);
607 strcpy(p->pack_name, path);
608 p->index_size = idx_size;
609 p->pack_size = 0;
610 p->index_base = idx_map;
611 p->next = NULL;
c41ee586 612 p->windows = NULL;
9bc879c1 613 p->pack_fd = -1;
e702496e 614 hashcpy(p->sha1, sha1);
bf592c50
DB
615 return p;
616}
617
618void install_packed_git(struct packed_git *pack)
619{
620 pack->next = packed_git;
621 packed_git = pack;
622}
623
9d835df2 624static void prepare_packed_git_one(char *objdir, int local)
1f688557
JH
625{
626 char path[PATH_MAX];
627 int len;
628 DIR *dir;
629 struct dirent *de;
630
631 sprintf(path, "%s/pack", objdir);
632 len = strlen(path);
633 dir = opendir(path);
b5b16990 634 if (!dir) {
26125f6b 635 if (errno != ENOENT)
bd2afde8 636 error("unable to open object pack directory: %s: %s",
26125f6b 637 path, strerror(errno));
1f688557 638 return;
b5b16990 639 }
1f688557
JH
640 path[len++] = '/';
641 while ((de = readdir(dir)) != NULL) {
642 int namelen = strlen(de->d_name);
643 struct packed_git *p;
644
5bb1cda5 645 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
646 continue;
647
648 /* we have .idx. Is it a file we can map? */
649 strcpy(path + len, de->d_name);
86f7780c
JK
650 for (p = packed_git; p; p = p->next) {
651 if (!memcmp(path, p->pack_name, len + namelen - 4))
652 break;
653 }
654 if (p)
655 continue;
9d835df2 656 p = add_packed_git(path, len + namelen, local);
1f688557
JH
657 if (!p)
658 continue;
659 p->next = packed_git;
660 packed_git = p;
661 }
5b35bcd5 662 closedir(dir);
1f688557
JH
663}
664
637cdd9d 665static int prepare_packed_git_run_once = 0;
9a217f2a 666void prepare_packed_git(void)
1f688557 667{
d5a63b99 668 struct alternate_object_database *alt;
1f688557 669
637cdd9d 670 if (prepare_packed_git_run_once)
1f688557 671 return;
9d835df2 672 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 673 prepare_alt_odb();
d5a63b99 674 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 675 alt->name[-1] = 0;
9d835df2 676 prepare_packed_git_one(alt->base, 0);
1494e038 677 alt->name[-1] = '/';
1f688557 678 }
637cdd9d
JK
679 prepare_packed_git_run_once = 1;
680}
681
fc04c412 682void reprepare_packed_git(void)
637cdd9d
JK
683{
684 prepare_packed_git_run_once = 0;
685 prepare_packed_git();
1f688557
JH
686}
687
5d6ccf5c 688int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
689{
690 unsigned char real_sha1[20];
7cfb5f36 691 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 692 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
693}
694
bb6b8e4f 695void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 696{
0fcfd160
LT
697 struct stat st;
698 void *map;
144bde78 699 int fd;
ace1534d
JH
700 char *filename = find_sha1_file(sha1, &st);
701
702 if (!filename) {
ace1534d
JH
703 return NULL;
704 }
0fcfd160 705
144bde78 706 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 707 if (fd < 0) {
144bde78
LT
708 /* See if it works without O_NOATIME */
709 switch (sha1_file_open_flag) {
710 default:
711 fd = open(filename, O_RDONLY);
712 if (fd >= 0)
713 break;
714 /* Fallthrough */
715 case 0:
144bde78
LT
716 return NULL;
717 }
718
1f688557
JH
719 /* If it failed once, it will probably fail again.
720 * Stop using O_NOATIME
721 */
144bde78 722 sha1_file_open_flag = 0;
0fcfd160 723 }
0fcfd160
LT
724 map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
725 close(fd);
e35f9824 726 if (map == MAP_FAILED)
0fcfd160
LT
727 return NULL;
728 *size = st.st_size;
729 return map;
730}
731
bb6b8e4f
JH
732int legacy_loose_object(unsigned char *map)
733{
734 unsigned int word;
735
736 /*
737 * Is it a zlib-compressed buffer? If so, the first byte
738 * must be 0x78 (15-bit window size, deflated), and the
739 * first 16-bit word is evenly divisible by 31
740 */
741 word = (map[0] << 8) + map[1];
742 if (map[0] == 0x78 && !(word % 31))
743 return 1;
744 else
745 return 0;
746}
747
72518e9c 748unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 749{
ad1ed5ee 750 unsigned shift;
93821bd9 751 unsigned char c;
93821bd9 752 unsigned long size;
ad1ed5ee
JH
753 unsigned long used = 0;
754
755 c = buf[used++];
756 *type = (c >> 4) & 7;
757 size = c & 15;
758 shift = 4;
759 while (c & 0x80) {
760 if (len <= used)
761 return 0;
762 if (sizeof(long) * 8 <= shift)
763 return 0;
764 c = buf[used++];
765 size += (c & 0x7f) << shift;
766 shift += 7;
767 }
768 *sizep = size;
769 return used;
770}
771
772static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
773{
774 unsigned long size, used;
775 static const char valid_loose_object_type[8] = {
776 0, /* OBJ_EXT */
777 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
778 0, /* "delta" and others are invalid in a loose object */
93821bd9 779 };
ad1ed5ee 780 enum object_type type;
93821bd9 781
c4483576
LT
782 /* Get the data stream */
783 memset(stream, 0, sizeof(*stream));
784 stream->next_in = map;
785 stream->avail_in = mapsize;
786 stream->next_out = buffer;
93821bd9
LT
787 stream->avail_out = bufsiz;
788
bb6b8e4f 789 if (legacy_loose_object(map)) {
93821bd9
LT
790 inflateInit(stream);
791 return inflate(stream, 0);
792 }
793
ad1ed5ee
JH
794 used = unpack_object_header_gently(map, mapsize, &type, &size);
795 if (!used || !valid_loose_object_type[type])
93821bd9 796 return -1;
ad1ed5ee
JH
797 map += used;
798 mapsize -= used;
93821bd9
LT
799
800 /* Set up the stream for the rest.. */
801 stream->next_in = map;
802 stream->avail_in = mapsize;
c4483576 803 inflateInit(stream);
93821bd9
LT
804
805 /* And generate the fake traditional header */
ad1ed5ee
JH
806 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
807 type_names[type], size);
93821bd9 808 return 0;
c4483576
LT
809}
810
6da4016a 811static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size)
5180cacc
LT
812{
813 int bytes = strlen(buffer) + 1;
d565b341 814 unsigned char *buf = xmalloc(1+size);
93821bd9 815 unsigned long n;
5180cacc 816
93821bd9
LT
817 n = stream->total_out - bytes;
818 if (n > size)
819 n = size;
820 memcpy(buf, (char *) buffer + bytes, n);
821 bytes = n;
5180cacc
LT
822 if (bytes < size) {
823 stream->next_out = buf + bytes;
824 stream->avail_out = size - bytes;
825 while (inflate(stream, Z_FINISH) == Z_OK)
826 /* nothing */;
827 }
828 buf[size] = 0;
829 inflateEnd(stream);
830 return buf;
831}
832
833/*
834 * We used to just use "sscanf()", but that's actually way
835 * too permissive for what we want to check. So do an anal
836 * object header parse by hand.
837 */
38d3874d 838static int parse_sha1_header(char *hdr, char *type, unsigned long *sizep)
5180cacc
LT
839{
840 int i;
841 unsigned long size;
842
843 /*
844 * The type can be at most ten bytes (including the
845 * terminating '\0' that we add), and is followed by
846 * a space.
847 */
848 i = 10;
849 for (;;) {
850 char c = *hdr++;
851 if (c == ' ')
852 break;
853 if (!--i)
854 return -1;
855 *type++ = c;
856 }
857 *type = 0;
858
859 /*
860 * The length must follow immediately, and be in canonical
861 * decimal format (ie "010" is not valid).
862 */
863 size = *hdr++ - '0';
864 if (size > 9)
865 return -1;
866 if (size) {
867 for (;;) {
868 unsigned long c = *hdr - '0';
869 if (c > 9)
870 break;
871 hdr++;
872 size = size * 10 + c;
873 }
874 }
875 *sizep = size;
876
877 /*
878 * The length must be followed by a zero byte
879 */
880 return *hdr ? -1 : 0;
881}
882
0fcfd160
LT
883void * unpack_sha1_file(void *map, unsigned long mapsize, char *type, unsigned long *size)
884{
5180cacc 885 int ret;
0fcfd160 886 z_stream stream;
5180cacc 887 char hdr[8192];
0fcfd160 888
5180cacc
LT
889 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
890 if (ret < Z_OK || parse_sha1_header(hdr, type, size) < 0)
0fcfd160
LT
891 return NULL;
892
5180cacc 893 return unpack_sha1_rest(&stream, hdr, *size);
0fcfd160
LT
894}
895
eb32d236 896static unsigned long get_delta_base(struct packed_git *p,
03e79c88 897 struct pack_window **w_curs,
eb32d236
NP
898 unsigned long offset,
899 enum object_type kind,
900 unsigned long delta_obj_offset,
901 unsigned long *base_obj_offset)
902{
03e79c88 903 unsigned char *base_info = use_pack(p, w_curs, offset, NULL);
eb32d236
NP
904 unsigned long base_offset;
905
906 /* there must be at least 20 bytes left regardless of delta type */
907 if (p->pack_size <= offset + 20)
908 die("truncated pack file");
909
910 if (kind == OBJ_OFS_DELTA) {
911 unsigned used = 0;
912 unsigned char c = base_info[used++];
913 base_offset = c & 127;
914 while (c & 128) {
915 base_offset += 1;
916 if (!base_offset || base_offset & ~(~0UL >> 7))
917 die("offset value overflow for delta base object");
918 c = base_info[used++];
919 base_offset = (base_offset << 7) + (c & 127);
920 }
921 base_offset = delta_obj_offset - base_offset;
922 if (base_offset >= delta_obj_offset)
923 die("delta base offset out of bound");
924 offset += used;
925 } else if (kind == OBJ_REF_DELTA) {
926 /* The base entry _must_ be in the same pack */
927 base_offset = find_pack_entry_one(base_info, p);
928 if (!base_offset)
929 die("failed to find delta-pack base object %s",
930 sha1_to_hex(base_info));
931 offset += 20;
932 } else
933 die("I am totally screwed");
934 *base_obj_offset = base_offset;
935 return offset;
936}
937
f3bf9224 938/* forward declaration for a mutually recursive function */
43057304 939static int packed_object_info(struct packed_git *p, unsigned long offset,
f3bf9224
JH
940 char *type, unsigned long *sizep);
941
43057304 942static int packed_delta_info(struct packed_git *p,
03e79c88 943 struct pack_window **w_curs,
43057304 944 unsigned long offset,
eb32d236
NP
945 enum object_type kind,
946 unsigned long obj_offset,
5db47c2b 947 char *type,
43057304 948 unsigned long *sizep)
5db47c2b 949{
43057304 950 unsigned long base_offset;
f3bf9224 951
03e79c88
SP
952 offset = get_delta_base(p, w_curs, offset, kind,
953 obj_offset, &base_offset);
f3bf9224 954
c62266f3
JH
955 /* We choose to only get the type of the base object and
956 * ignore potentially corrupt pack file that expects the delta
957 * based on a base with a wrong size. This saves tons of
958 * inflate() calls.
959 */
43057304 960 if (packed_object_info(p, base_offset, type, NULL))
c62266f3 961 die("cannot get info for delta-pack base");
5db47c2b 962
c62266f3
JH
963 if (sizep) {
964 const unsigned char *data;
1a3b55c6 965 unsigned char delta_head[20];
c62266f3
JH
966 unsigned long result_size;
967 z_stream stream;
968 int st;
969
970 memset(&stream, 0, sizeof(stream));
971
03e79c88 972 stream.next_in = use_pack(p, w_curs, offset, &stream.avail_in);
c62266f3
JH
973 stream.next_out = delta_head;
974 stream.avail_out = sizeof(delta_head);
975
976 inflateInit(&stream);
977 st = inflate(&stream, Z_FINISH);
978 inflateEnd(&stream);
979 if ((st != Z_STREAM_END) &&
980 stream.total_out != sizeof(delta_head))
981 die("delta data unpack-initial failed");
982
983 /* Examine the initial part of the delta to figure out
984 * the result size.
985 */
986 data = delta_head;
8960844a
NP
987
988 /* ignore base size */
989 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
5db47c2b 990
c62266f3 991 /* Read the result size */
8960844a 992 result_size = get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
c62266f3
JH
993 *sizep = result_size;
994 }
5db47c2b
JH
995 return 0;
996}
997
03e79c88
SP
998static unsigned long unpack_object_header(struct packed_git *p,
999 struct pack_window **w_curs,
1000 unsigned long offset,
1001 enum object_type *type,
1002 unsigned long *sizep)
a733cb60 1003{
03e79c88
SP
1004 unsigned char *base;
1005 unsigned int left;
ad1ed5ee 1006 unsigned long used;
a733cb60 1007
03e79c88
SP
1008 base = use_pack(p, w_curs, offset, &left);
1009 used = unpack_object_header_gently(base, left, type, sizep);
ad1ed5ee
JH
1010 if (!used)
1011 die("object offset outside of pack file");
1012
1013 return offset + used;
a733cb60
LT
1014}
1015
43057304
NP
1016void packed_object_info_detail(struct packed_git *p,
1017 unsigned long offset,
ad8c80a5
JH
1018 char *type,
1019 unsigned long *size,
1020 unsigned long *store_size,
f8f135c9 1021 unsigned int *delta_chain_length,
ad8c80a5
JH
1022 unsigned char *base_sha1)
1023{
03e79c88 1024 struct pack_window *w_curs = NULL;
eb32d236 1025 unsigned long obj_offset, val;
43057304 1026 unsigned char *next_sha1;
ad8c80a5
JH
1027 enum object_type kind;
1028
43057304 1029 *delta_chain_length = 0;
eb32d236 1030 obj_offset = offset;
03e79c88 1031 offset = unpack_object_header(p, &w_curs, offset, &kind, size);
43057304
NP
1032
1033 for (;;) {
1034 switch (kind) {
1035 default:
08a19d87 1036 die("pack %s contains unknown object type %d",
43057304
NP
1037 p->pack_name, kind);
1038 case OBJ_COMMIT:
1039 case OBJ_TREE:
1040 case OBJ_BLOB:
1041 case OBJ_TAG:
1042 strcpy(type, type_names[kind]);
1043 *store_size = 0; /* notyet */
03e79c88 1044 unuse_pack(&w_curs);
43057304 1045 return;
eb32d236 1046 case OBJ_OFS_DELTA:
03e79c88
SP
1047 get_delta_base(p, &w_curs, offset, kind,
1048 obj_offset, &offset);
eb32d236
NP
1049 if (*delta_chain_length == 0) {
1050 /* TODO: find base_sha1 as pointed by offset */
1051 }
1052 break;
1053 case OBJ_REF_DELTA:
03e79c88 1054 next_sha1 = use_pack(p, &w_curs, offset, NULL);
43057304
NP
1055 if (*delta_chain_length == 0)
1056 hashcpy(base_sha1, next_sha1);
1057 offset = find_pack_entry_one(next_sha1, p);
1058 break;
1059 }
eb32d236 1060 obj_offset = offset;
03e79c88 1061 offset = unpack_object_header(p, &w_curs, offset, &kind, &val);
43057304 1062 (*delta_chain_length)++;
ad8c80a5 1063 }
ad8c80a5
JH
1064}
1065
43057304 1066static int packed_object_info(struct packed_git *p, unsigned long offset,
1f688557
JH
1067 char *type, unsigned long *sizep)
1068{
03e79c88 1069 struct pack_window *w_curs = NULL;
eb32d236 1070 unsigned long size, obj_offset = offset;
a733cb60 1071 enum object_type kind;
03e79c88 1072 int r;
5db47c2b 1073
03e79c88 1074 offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
5db47c2b 1075
a733cb60 1076 switch (kind) {
eb32d236
NP
1077 case OBJ_OFS_DELTA:
1078 case OBJ_REF_DELTA:
03e79c88
SP
1079 r = packed_delta_info(p, &w_curs, offset, kind,
1080 obj_offset, type, sizep);
1081 unuse_pack(&w_curs);
1082 return r;
a733cb60 1083 case OBJ_COMMIT:
a733cb60 1084 case OBJ_TREE:
a733cb60 1085 case OBJ_BLOB:
a733cb60 1086 case OBJ_TAG:
5a18f540 1087 strcpy(type, type_names[kind]);
03e79c88 1088 unuse_pack(&w_curs);
a69d0943 1089 break;
1f688557 1090 default:
08a19d87 1091 die("pack %s contains unknown object type %d",
264b16b6 1092 p->pack_name, kind);
1f688557 1093 }
c62266f3
JH
1094 if (sizep)
1095 *sizep = size;
1f688557
JH
1096 return 0;
1097}
1098
eb950c19 1099static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1100 struct pack_window **w_curs,
eb950c19
SP
1101 unsigned long offset,
1102 unsigned long size)
de530aaa
SP
1103{
1104 int st;
1105 z_stream stream;
1106 unsigned char *buffer;
1107
1108 buffer = xmalloc(size + 1);
1109 buffer[size] = 0;
1110 memset(&stream, 0, sizeof(stream));
03e79c88 1111 stream.next_in = use_pack(p, w_curs, offset, &stream.avail_in);
de530aaa
SP
1112 stream.next_out = buffer;
1113 stream.avail_out = size;
1114
1115 inflateInit(&stream);
1116 st = inflate(&stream, Z_FINISH);
1117 inflateEnd(&stream);
1118 if ((st != Z_STREAM_END) || stream.total_out != size) {
1119 free(buffer);
1120 return NULL;
1121 }
1122
1123 return buffer;
1124}
1125
eb950c19 1126static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1127 struct pack_window **w_curs,
eb950c19 1128 unsigned long offset,
1f688557 1129 unsigned long delta_size,
eb32d236
NP
1130 enum object_type kind,
1131 unsigned long obj_offset,
1f688557 1132 char *type,
eb950c19 1133 unsigned long *sizep)
1f688557 1134{
7c3e8be3 1135 void *delta_data, *result, *base;
43057304 1136 unsigned long result_size, base_size, base_offset;
43057304 1137
03e79c88
SP
1138 offset = get_delta_base(p, w_curs, offset, kind,
1139 obj_offset, &base_offset);
4d703a1a 1140 base = unpack_entry(p, base_offset, type, &base_size);
67686d95 1141 if (!base)
43057304
NP
1142 die("failed to read delta base object at %lu from %s",
1143 base_offset, p->pack_name);
67686d95 1144
03e79c88 1145 delta_data = unpack_compressed_entry(p, w_curs, offset, delta_size);
1f688557
JH
1146 result = patch_delta(base, base_size,
1147 delta_data, delta_size,
1148 &result_size);
1149 if (!result)
1150 die("failed to apply delta");
1151 free(delta_data);
1152 free(base);
1153 *sizep = result_size;
1154 return result;
1155}
1156
4d703a1a 1157void *unpack_entry(struct packed_git *p, unsigned long offset,
1f688557
JH
1158 char *type, unsigned long *sizep)
1159{
03e79c88 1160 struct pack_window *w_curs = NULL;
4d703a1a
SP
1161 unsigned long size, obj_offset = offset;
1162 enum object_type kind;
f9253394 1163 void *retval;
1f688557 1164
03e79c88 1165 offset = unpack_object_header(p, &w_curs, offset, &kind, &size);
a733cb60 1166 switch (kind) {
eb32d236
NP
1167 case OBJ_OFS_DELTA:
1168 case OBJ_REF_DELTA:
03e79c88
SP
1169 retval = unpack_delta_entry(p, &w_curs, offset, size,
1170 kind, obj_offset, type, sizep);
4d703a1a 1171 break;
a733cb60 1172 case OBJ_COMMIT:
a733cb60 1173 case OBJ_TREE:
a733cb60 1174 case OBJ_BLOB:
a733cb60 1175 case OBJ_TAG:
5a18f540
SP
1176 strcpy(type, type_names[kind]);
1177 *sizep = size;
03e79c88 1178 retval = unpack_compressed_entry(p, &w_curs, offset, size);
4d703a1a 1179 break;
1f688557 1180 default:
4d703a1a 1181 die("unknown object type %i in %s", kind, p->pack_name);
1f688557 1182 }
03e79c88 1183 unuse_pack(&w_curs);
4d703a1a 1184 return retval;
1f688557
JH
1185}
1186
9a217f2a
JH
1187int num_packed_objects(const struct packed_git *p)
1188{
f9253394 1189 /* See check_packed_git_idx() */
9a217f2a
JH
1190 return (p->index_size - 20 - 20 - 4*256) / 24;
1191}
1192
1193int nth_packed_object_sha1(const struct packed_git *p, int n,
1194 unsigned char* sha1)
1195{
1196 void *index = p->index_base + 256;
1197 if (n < 0 || num_packed_objects(p) <= n)
1198 return -1;
e702496e 1199 hashcpy(sha1, (unsigned char *) index + (24 * n) + 4);
9a217f2a
JH
1200 return 0;
1201}
1202
43057304
NP
1203unsigned long find_pack_entry_one(const unsigned char *sha1,
1204 struct packed_git *p)
1f688557 1205{
4d235c80 1206 unsigned int *level1_ofs = p->index_base;
1f688557
JH
1207 int hi = ntohl(level1_ofs[*sha1]);
1208 int lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1209 void *index = p->index_base + 256;
1210
1211 do {
1212 int mi = (lo + hi) / 2;
a89fccd2 1213 int cmp = hashcmp((unsigned char *)index + (24 * mi) + 4, sha1);
43057304
NP
1214 if (!cmp)
1215 return ntohl(*((unsigned int *) ((char *) index + (24 * mi))));
1f688557
JH
1216 if (cmp > 0)
1217 hi = mi;
1218 else
1219 lo = mi+1;
1220 } while (lo < hi);
1221 return 0;
1222}
1223
d4ff6d92
SP
1224static int matches_pack_name(struct packed_git *p, const char *ig)
1225{
1226 const char *last_c, *c;
1227
1228 if (!strcmp(p->pack_name, ig))
1229 return 0;
1230
1231 for (c = p->pack_name, last_c = c; *c;)
1232 if (*c == '/')
1233 last_c = ++c;
1234 else
1235 ++c;
1236 if (!strcmp(last_c, ig))
1237 return 0;
1238
1239 return 1;
1240}
1241
106d710b 1242static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557
JH
1243{
1244 struct packed_git *p;
43057304
NP
1245 unsigned long offset;
1246
1f688557
JH
1247 prepare_packed_git();
1248
1249 for (p = packed_git; p; p = p->next) {
106d710b
JH
1250 if (ignore_packed) {
1251 const char **ig;
1252 for (ig = ignore_packed; *ig; ig++)
d4ff6d92 1253 if (!matches_pack_name(p, *ig))
106d710b
JH
1254 break;
1255 if (*ig)
1256 continue;
1257 }
43057304
NP
1258 offset = find_pack_entry_one(sha1, p);
1259 if (offset) {
1260 e->offset = offset;
1261 e->p = p;
1262 hashcpy(e->sha1, sha1);
1f688557 1263 return 1;
43057304 1264 }
1f688557
JH
1265 }
1266 return 0;
1267}
1268
bf592c50
DB
1269struct packed_git *find_sha1_pack(const unsigned char *sha1,
1270 struct packed_git *packs)
1271{
1272 struct packed_git *p;
bf592c50
DB
1273
1274 for (p = packs; p; p = p->next) {
43057304 1275 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1276 return p;
1277 }
1278 return NULL;
1279
1280}
1281
f0df4ed5 1282static int sha1_loose_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
65c2e0c3 1283{
36e4d74a 1284 int status;
65c2e0c3
JH
1285 unsigned long mapsize, size;
1286 void *map;
1287 z_stream stream;
36e4d74a 1288 char hdr[128];
65c2e0c3 1289
bb6b8e4f 1290 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1291 if (!map)
1292 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1293 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1294 status = error("unable to unpack %s header",
1295 sha1_to_hex(sha1));
1296 if (parse_sha1_header(hdr, type, &size) < 0)
1297 status = error("unable to parse %s header", sha1_to_hex(sha1));
c4584ae3 1298 else {
65c2e0c3 1299 status = 0;
c62266f3
JH
1300 if (sizep)
1301 *sizep = size;
65c2e0c3 1302 }
65c2e0c3
JH
1303 inflateEnd(&stream);
1304 munmap(map, mapsize);
1305 return status;
1306}
1307
f0df4ed5
JS
1308int sha1_object_info(const unsigned char *sha1, char *type, unsigned long *sizep)
1309{
f0df4ed5
JS
1310 struct pack_entry e;
1311
1312 if (!find_pack_entry(sha1, &e, NULL)) {
1313 reprepare_packed_git();
1314 if (!find_pack_entry(sha1, &e, NULL))
1315 return sha1_loose_object_info(sha1, type, sizep);
1316 }
03e79c88 1317 return packed_object_info(e.p, e.offset, type, sizep);
f0df4ed5
JS
1318}
1319
1f688557
JH
1320static void *read_packed_sha1(const unsigned char *sha1, char *type, unsigned long *size)
1321{
1322 struct pack_entry e;
1323
106d710b 1324 if (!find_pack_entry(sha1, &e, NULL)) {
1f688557
JH
1325 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
1326 return NULL;
1327 }
4d703a1a 1328 return unpack_entry(e.p, e.offset, type, size);
1f688557
JH
1329}
1330
0fcfd160
LT
1331void * read_sha1_file(const unsigned char *sha1, char *type, unsigned long *size)
1332{
1333 unsigned long mapsize;
1334 void *map, *buf;
ab90ea5d 1335 struct pack_entry e;
0fcfd160 1336
106d710b 1337 if (find_pack_entry(sha1, &e, NULL))
ab90ea5d 1338 return read_packed_sha1(sha1, type, size);
bb6b8e4f 1339 map = map_sha1_file(sha1, &mapsize);
0fcfd160
LT
1340 if (map) {
1341 buf = unpack_sha1_file(map, mapsize, type, size);
1342 munmap(map, mapsize);
1343 return buf;
1344 }
637cdd9d 1345 reprepare_packed_git();
106d710b 1346 if (find_pack_entry(sha1, &e, NULL))
637cdd9d 1347 return read_packed_sha1(sha1, type, size);
ab90ea5d 1348 return NULL;
0fcfd160
LT
1349}
1350
40469ee9 1351void *read_object_with_reference(const unsigned char *sha1,
bf0f910d 1352 const char *required_type,
40469ee9
JH
1353 unsigned long *size,
1354 unsigned char *actual_sha1_return)
f4913f91
JH
1355{
1356 char type[20];
1357 void *buffer;
1358 unsigned long isize;
40469ee9 1359 unsigned char actual_sha1[20];
f4913f91 1360
e702496e 1361 hashcpy(actual_sha1, sha1);
40469ee9
JH
1362 while (1) {
1363 int ref_length = -1;
1364 const char *ref_type = NULL;
f4913f91 1365
40469ee9
JH
1366 buffer = read_sha1_file(actual_sha1, type, &isize);
1367 if (!buffer)
1368 return NULL;
1369 if (!strcmp(type, required_type)) {
1370 *size = isize;
1371 if (actual_sha1_return)
e702496e 1372 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1373 return buffer;
1374 }
1375 /* Handle references */
8e440259 1376 else if (!strcmp(type, commit_type))
40469ee9 1377 ref_type = "tree ";
8e440259 1378 else if (!strcmp(type, tag_type))
40469ee9
JH
1379 ref_type = "object ";
1380 else {
1381 free(buffer);
1382 return NULL;
1383 }
1384 ref_length = strlen(ref_type);
f4913f91 1385
40469ee9 1386 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1387 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1388 free(buffer);
1389 return NULL;
1390 }
1cf58e72 1391 free(buffer);
40469ee9
JH
1392 /* Now we have the ID of the referred-to object in
1393 * actual_sha1. Check again. */
f4913f91 1394 }
f4913f91
JH
1395}
1396
972a9155
RS
1397static void write_sha1_file_prepare(void *buf, unsigned long len,
1398 const char *type, unsigned char *sha1,
1399 unsigned char *hdr, int *hdrlen)
d410c0f5
JH
1400{
1401 SHA_CTX c;
1402
1403 /* Generate the header */
1404 *hdrlen = sprintf((char *)hdr, "%s %lu", type, len)+1;
1405
1406 /* Sha1.. */
1407 SHA1_Init(&c);
1408 SHA1_Update(&c, hdr, *hdrlen);
1409 SHA1_Update(&c, buf, len);
1410 SHA1_Final(sha1, &c);
d410c0f5
JH
1411}
1412
230f1322
LT
1413/*
1414 * Link the tempfile to the final place, possibly creating the
1415 * last directory level as you do so.
1416 *
1417 * Returns the errno on failure, 0 on success.
1418 */
839837b9 1419static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1420{
1421 int ret;
756aaf4a 1422 char *dir;
230f1322
LT
1423
1424 if (!link(tmpfile, filename))
1425 return 0;
1426
1427 /*
756aaf4a 1428 * Try to mkdir the last path component if that failed.
230f1322
LT
1429 *
1430 * Re-try the "link()" regardless of whether the mkdir
1431 * succeeds, since a race might mean that somebody
1432 * else succeeded.
1433 */
1434 ret = errno;
756aaf4a
SP
1435 dir = strrchr(filename, '/');
1436 if (dir) {
1437 *dir = 0;
866cae0d 1438 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
91c23e48 1439 *dir = '/';
756aaf4a 1440 return -2;
91c23e48 1441 }
756aaf4a
SP
1442 *dir = '/';
1443 if (!link(tmpfile, filename))
1444 return 0;
1445 ret = errno;
230f1322
LT
1446 }
1447 return ret;
1448}
1449
1450/*
1451 * Move the just written object into its final resting place
1452 */
839837b9 1453int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1454{
1455 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
1456
1457 /*
1458 * Coda hack - coda doesn't like cross-directory links,
1459 * so we fall back to a rename, which will mean that it
1460 * won't be able to check collisions, but that's not a
1461 * big deal.
1462 *
1463 * The same holds for FAT formatted media.
1464 *
1465 * When this succeeds, we just return 0. We have nothing
1466 * left to unlink.
1467 */
1468 if (ret && ret != EEXIST) {
1469 if (!rename(tmpfile, filename))
230f1322 1470 return 0;
9e48b389 1471 ret = errno;
230f1322
LT
1472 }
1473 unlink(tmpfile);
1474 if (ret) {
1475 if (ret != EEXIST) {
916d081b 1476 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
1477 }
1478 /* FIXME!!! Collision check here ? */
1479 }
1480
1481 return 0;
1482}
1483
4d548150
LT
1484static int write_buffer(int fd, const void *buf, size_t len)
1485{
1486 while (len) {
1487 ssize_t size;
1488
1489 size = write(fd, buf, len);
1490 if (!size)
1491 return error("file write: disk full");
1492 if (size < 0) {
1493 if (errno == EINTR || errno == EAGAIN)
1494 continue;
1495 return error("file write error (%s)", strerror(errno));
1496 }
1497 len -= size;
1d7f171c 1498 buf = (char *) buf + size;
4d548150
LT
1499 }
1500 return 0;
1501}
1502
93821bd9
LT
1503static int write_binary_header(unsigned char *hdr, enum object_type type, unsigned long len)
1504{
1505 int hdr_len;
1506 unsigned char c;
1507
1508 c = (type << 4) | (len & 15);
1509 len >>= 4;
1510 hdr_len = 1;
1511 while (len) {
1512 *hdr++ = c | 0x80;
1513 hdr_len++;
1514 c = (len & 0x7f);
1515 len >>= 7;
1516 }
1517 *hdr = c;
1518 return hdr_len;
1519}
1520
1521static void setup_object_header(z_stream *stream, const char *type, unsigned long len)
1522{
1523 int obj_type, hdr;
1524
1525 if (use_legacy_headers) {
1526 while (deflate(stream, 0) == Z_OK)
1527 /* nothing */;
1528 return;
1529 }
1530 if (!strcmp(type, blob_type))
1531 obj_type = OBJ_BLOB;
1532 else if (!strcmp(type, tree_type))
1533 obj_type = OBJ_TREE;
1534 else if (!strcmp(type, commit_type))
1535 obj_type = OBJ_COMMIT;
1536 else if (!strcmp(type, tag_type))
1537 obj_type = OBJ_TAG;
1538 else
1539 die("trying to generate bogus object of type '%s'", type);
1540 hdr = write_binary_header(stream->next_out, obj_type, len);
1541 stream->total_out = hdr;
1542 stream->next_out += hdr;
1543 stream->avail_out -= hdr;
1544}
1545
abdc3fc8
RS
1546int hash_sha1_file(void *buf, unsigned long len, const char *type,
1547 unsigned char *sha1)
1548{
1549 unsigned char hdr[50];
1550 int hdrlen;
1551 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1552 return 0;
1553}
1554
bf0f910d 1555int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160
LT
1556{
1557 int size;
bf0f910d 1558 unsigned char *compressed;
0fcfd160
LT
1559 z_stream stream;
1560 unsigned char sha1[20];
706bc531 1561 char *filename;
aac17941 1562 static char tmpfile[PATH_MAX];
bf0f910d 1563 unsigned char hdr[50];
230f1322 1564 int fd, hdrlen;
a44c9a5e 1565
d410c0f5
JH
1566 /* Normally if we have it in the pack then we do not bother writing
1567 * it out into .git/objects/??/?{38} file.
1568 */
972a9155
RS
1569 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
1570 filename = sha1_file_name(sha1);
706bc531 1571 if (returnsha1)
e702496e 1572 hashcpy(returnsha1, sha1);
d410c0f5
JH
1573 if (has_sha1_file(sha1))
1574 return 0;
aac17941
LT
1575 fd = open(filename, O_RDONLY);
1576 if (fd >= 0) {
706bc531 1577 /*
aac17941
LT
1578 * FIXME!!! We might do collision checking here, but we'd
1579 * need to uncompress the old file and check it. Later.
706bc531 1580 */
aac17941 1581 close(fd);
706bc531
LT
1582 return 0;
1583 }
1584
aac17941 1585 if (errno != ENOENT) {
916d081b 1586 return error("sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
1587 }
1588
1589 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
ace1534d 1590
aac17941
LT
1591 fd = mkstemp(tmpfile);
1592 if (fd < 0) {
916d081b
PB
1593 if (errno == EPERM)
1594 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1595 else
1596 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
1597 }
1598
0fcfd160
LT
1599 /* Set it up */
1600 memset(&stream, 0, sizeof(stream));
12f6c308 1601 deflateInit(&stream, zlib_compression_level);
93821bd9 1602 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 1603 compressed = xmalloc(size);
0fcfd160
LT
1604
1605 /* Compress it */
0fcfd160
LT
1606 stream.next_out = compressed;
1607 stream.avail_out = size;
a44c9a5e
LT
1608
1609 /* First header.. */
1610 stream.next_in = hdr;
1611 stream.avail_in = hdrlen;
93821bd9 1612 setup_object_header(&stream, type, len);
a44c9a5e
LT
1613
1614 /* Then the data itself.. */
1615 stream.next_in = buf;
1616 stream.avail_in = len;
0fcfd160
LT
1617 while (deflate(&stream, Z_FINISH) == Z_OK)
1618 /* nothing */;
1619 deflateEnd(&stream);
1620 size = stream.total_out;
1621
4d548150
LT
1622 if (write_buffer(fd, compressed, size) < 0)
1623 die("unable to write sha1 file");
aac17941 1624 fchmod(fd, 0444);
706bc531 1625 close(fd);
383f85b7 1626 free(compressed);
0fcfd160 1627
230f1322 1628 return move_temp_to_file(tmpfile, filename);
0fcfd160 1629}
8237b185 1630
4d548150
LT
1631/*
1632 * We need to unpack and recompress the object for writing
1633 * it out to a different file.
1634 */
1635static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 1636{
4d548150 1637 size_t size;
a5eda52b 1638 z_stream stream;
4d548150
LT
1639 unsigned char *unpacked;
1640 unsigned long len;
1641 char type[20];
1642 char hdr[50];
1643 int hdrlen;
1644 void *buf;
bfc66daf 1645
a9486b02 1646 /* need to unpack and recompress it by itself */
4d548150 1647 unpacked = read_packed_sha1(sha1, type, &len);
a5eda52b 1648
4d548150 1649 hdrlen = sprintf(hdr, "%s %lu", type, len) + 1;
a5eda52b 1650
4d548150
LT
1651 /* Set it up */
1652 memset(&stream, 0, sizeof(stream));
12f6c308 1653 deflateInit(&stream, zlib_compression_level);
4d548150
LT
1654 size = deflateBound(&stream, len + hdrlen);
1655 buf = xmalloc(size);
a5eda52b 1656
4d548150
LT
1657 /* Compress it */
1658 stream.next_out = buf;
1659 stream.avail_out = size;
a5eda52b 1660
4d548150
LT
1661 /* First header.. */
1662 stream.next_in = (void *)hdr;
1663 stream.avail_in = hdrlen;
1664 while (deflate(&stream, 0) == Z_OK)
1665 /* nothing */;
bfc66daf 1666
4d548150
LT
1667 /* Then the data itself.. */
1668 stream.next_in = unpacked;
1669 stream.avail_in = len;
1670 while (deflate(&stream, Z_FINISH) == Z_OK)
1671 /* nothing */;
1672 deflateEnd(&stream);
1673 free(unpacked);
bfc66daf 1674
4d548150
LT
1675 *objsize = stream.total_out;
1676 return buf;
1677}
1678
1679int write_sha1_to_fd(int fd, const unsigned char *sha1)
1680{
1681 int retval;
1682 unsigned long objsize;
bb6b8e4f 1683 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
1684
1685 if (buf) {
1686 retval = write_buffer(fd, buf, objsize);
1687 munmap(buf, objsize);
1688 return retval;
1689 }
1690
1691 buf = repack_object(sha1, &objsize);
1692 retval = write_buffer(fd, buf, objsize);
1693 free(buf);
1694 return retval;
a5eda52b
DB
1695}
1696
70b9829e
DB
1697int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
1698 size_t bufsize, size_t *bufposn)
8237b185 1699{
230f1322 1700 char tmpfile[PATH_MAX];
8237b185
DB
1701 int local;
1702 z_stream stream;
1703 unsigned char real_sha1[20];
bf0f910d 1704 unsigned char discard[4096];
8237b185
DB
1705 int ret;
1706 SHA_CTX c;
1707
230f1322 1708 snprintf(tmpfile, sizeof(tmpfile), "%s/obj_XXXXXX", get_object_directory());
8237b185 1709
230f1322 1710 local = mkstemp(tmpfile);
916d081b
PB
1711 if (local < 0) {
1712 if (errno == EPERM)
1713 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
1714 else
1715 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
1716 }
8237b185
DB
1717
1718 memset(&stream, 0, sizeof(stream));
1719
1720 inflateInit(&stream);
1721
1722 SHA1_Init(&c);
1723
1724 do {
1725 ssize_t size;
70b9829e
DB
1726 if (*bufposn) {
1727 stream.avail_in = *bufposn;
96ad15ae 1728 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
1729 do {
1730 stream.next_out = discard;
1731 stream.avail_out = sizeof(discard);
1732 ret = inflate(&stream, Z_SYNC_FLUSH);
1733 SHA1_Update(&c, discard, sizeof(discard) -
1734 stream.avail_out);
1735 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
1736 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
1737 die("unable to write sha1 file");
70b9829e
DB
1738 memmove(buffer, buffer + *bufposn - stream.avail_in,
1739 stream.avail_in);
1740 *bufposn = stream.avail_in;
1741 if (ret != Z_OK)
1742 break;
1743 }
1744 size = read(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
1745 if (size <= 0) {
1746 close(local);
230f1322 1747 unlink(tmpfile);
8237b185
DB
1748 if (!size)
1749 return error("Connection closed?");
1750 perror("Reading from connection");
1751 return -1;
1752 }
70b9829e
DB
1753 *bufposn += size;
1754 } while (1);
8237b185
DB
1755 inflateEnd(&stream);
1756
1757 close(local);
1758 SHA1_Final(real_sha1, &c);
1759 if (ret != Z_STREAM_END) {
230f1322 1760 unlink(tmpfile);
8237b185
DB
1761 return error("File %s corrupted", sha1_to_hex(sha1));
1762 }
a89fccd2 1763 if (hashcmp(sha1, real_sha1)) {
230f1322 1764 unlink(tmpfile);
bd2afde8 1765 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 1766 }
230f1322
LT
1767
1768 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
1769}
1770
bf592c50
DB
1771int has_pack_index(const unsigned char *sha1)
1772{
1773 struct stat st;
1774 if (stat(sha1_pack_index_name(sha1), &st))
1775 return 0;
1776 return 1;
1777}
1778
1779int has_pack_file(const unsigned char *sha1)
1780{
1781 struct stat st;
1782 if (stat(sha1_pack_name(sha1), &st))
1783 return 0;
1784 return 1;
1785}
1786
106d710b 1787int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
1788{
1789 struct pack_entry e;
106d710b 1790 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
1791}
1792
8237b185
DB
1793int has_sha1_file(const unsigned char *sha1)
1794{
8237b185 1795 struct stat st;
1f688557
JH
1796 struct pack_entry e;
1797
106d710b 1798 if (find_pack_entry(sha1, &e, NULL))
1f688557 1799 return 1;
ab90ea5d 1800 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 1801}
74400e71 1802
e7332f96
BE
1803/*
1804 * reads from fd as long as possible into a supplied buffer of size bytes.
82e5a82f 1805 * If necessary the buffer's size is increased using realloc()
e7332f96
BE
1806 *
1807 * returns 0 if anything went fine and -1 otherwise
1808 *
1809 * NOTE: both buf and size may change, but even when -1 is returned
1810 * you still have to free() it yourself.
1811 */
1812int read_pipe(int fd, char** return_buf, unsigned long* return_size)
024510c8 1813{
e7332f96
BE
1814 char* buf = *return_buf;
1815 unsigned long size = *return_size;
1816 int iret;
024510c8 1817 unsigned long off = 0;
e7332f96 1818
024510c8 1819 do {
e7332f96 1820 iret = xread(fd, buf + off, size - off);
024510c8
DB
1821 if (iret > 0) {
1822 off += iret;
1823 if (off == size) {
1824 size *= 2;
83572c1a 1825 buf = xrealloc(buf, size);
024510c8
DB
1826 }
1827 }
1828 } while (iret > 0);
e7332f96
BE
1829
1830 *return_buf = buf;
1831 *return_size = off;
1832
1833 if (iret < 0)
1834 return -1;
1835 return 0;
1836}
1837
1838int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
1839{
1840 unsigned long size = 4096;
2d7320d0 1841 char *buf = xmalloc(size);
e7332f96 1842 int ret;
e7332f96
BE
1843
1844 if (read_pipe(fd, &buf, &size)) {
024510c8
DB
1845 free(buf);
1846 return -1;
1847 }
e7332f96 1848
024510c8 1849 if (!type)
8e440259 1850 type = blob_type;
024510c8 1851 if (write_object)
e7332f96 1852 ret = write_sha1_file(buf, size, type, sha1);
abdc3fc8
RS
1853 else
1854 ret = hash_sha1_file(buf, size, type, sha1);
024510c8
DB
1855 free(buf);
1856 return ret;
1857}
1858
7672db20 1859int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, const char *type)
74400e71 1860{
74400e71 1861 unsigned long size = st->st_size;
aac17941
LT
1862 void *buf;
1863 int ret;
74400e71 1864
aac17941 1865 buf = "";
74400e71 1866 if (size)
aac17941 1867 buf = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 1868 close(fd);
e35f9824 1869 if (buf == MAP_FAILED)
74400e71
JH
1870 return -1;
1871
7672db20 1872 if (!type)
8e440259 1873 type = blob_type;
7672db20
BL
1874 if (write_object)
1875 ret = write_sha1_file(buf, size, type, sha1);
abdc3fc8
RS
1876 else
1877 ret = hash_sha1_file(buf, size, type, sha1);
aac17941
LT
1878 if (size)
1879 munmap(buf, size);
1880 return ret;
74400e71 1881}
ec1fcc16
JH
1882
1883int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
1884{
1885 int fd;
1886 char *target;
1887
1888 switch (st->st_mode & S_IFMT) {
1889 case S_IFREG:
1890 fd = open(path, O_RDONLY);
1891 if (fd < 0)
1892 return error("open(\"%s\"): %s", path,
1893 strerror(errno));
1894 if (index_fd(sha1, fd, st, write_object, NULL) < 0)
1895 return error("%s: failed to insert into database",
1896 path);
1897 break;
1898 case S_IFLNK:
1899 target = xmalloc(st->st_size+1);
1900 if (readlink(path, target, st->st_size+1) != st->st_size) {
1901 char *errstr = strerror(errno);
1902 free(target);
1903 return error("readlink(\"%s\"): %s", path,
1904 errstr);
1905 }
abdc3fc8
RS
1906 if (!write_object)
1907 hash_sha1_file(target, st->st_size, blob_type, sha1);
1908 else if (write_sha1_file(target, st->st_size, blob_type, sha1))
ec1fcc16
JH
1909 return error("%s: failed to insert into database",
1910 path);
1911 free(target);
1912 break;
1913 default:
1914 return error("%s: unsupported file type", path);
1915 }
1916 return 0;
1917}