Invoke "git gc --auto" from commit, merge, am and rebase.
[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"
f35a6d3b 16#include "refs.h"
0fcfd160 17
144bde78
LT
18#ifndef O_NOATIME
19#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
20#define O_NOATIME 01000000
21#else
22#define O_NOATIME 0
23#endif
24#endif
25
e05db0fd
PR
26#ifdef NO_C99_FORMAT
27#define SZ_FMT "lu"
28#else
29#define SZ_FMT "zu"
30#endif
31
96f1e58f 32const unsigned char null_sha1[20];
88cd621d 33
144bde78
LT
34static unsigned int sha1_file_open_flag = O_NOATIME;
35
192a6be2 36const signed char hexval_table[256] = {
e49521b5
JH
37 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
38 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
42 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
43 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
44 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
45 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
46 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
47 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
49 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
51 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
68 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
69};
0fcfd160
LT
70
71int get_sha1_hex(const char *hex, unsigned char *sha1)
72{
73 int i;
74 for (i = 0; i < 20; i++) {
75 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
76 if (val & ~0xff)
77 return -1;
78 *sha1++ = val;
79 hex += 2;
80 }
81 return 0;
82}
83
b2cb9425
JH
84int safe_create_leading_directories(char *path)
85{
86 char *pos = path;
67d42212
JR
87 struct stat st;
88
67ffdf4c
JS
89 if (*pos == '/')
90 pos++;
b2cb9425
JH
91
92 while (pos) {
93 pos = strchr(pos, '/');
94 if (!pos)
95 break;
96 *pos = 0;
67d42212
JR
97 if (!stat(path, &st)) {
98 /* path exists */
99 if (!S_ISDIR(st.st_mode)) {
b2cb9425 100 *pos = '/';
67d42212 101 return -3;
b2cb9425 102 }
457f06d6 103 }
67d42212
JR
104 else if (mkdir(path, 0777)) {
105 *pos = '/';
106 return -1;
107 }
457f06d6
JS
108 else if (adjust_shared_perm(path)) {
109 *pos = '/';
110 return -2;
111 }
b2cb9425
JH
112 *pos++ = '/';
113 }
114 return 0;
115}
723c31fe 116
0fcfd160
LT
117char * sha1_to_hex(const unsigned char *sha1)
118{
dcb3450f
LT
119 static int bufno;
120 static char hexbuffer[4][50];
0fcfd160 121 static const char hex[] = "0123456789abcdef";
dcb3450f 122 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
123 int i;
124
125 for (i = 0; i < 20; i++) {
126 unsigned int val = *sha1++;
127 *buf++ = hex[val >> 4];
128 *buf++ = hex[val & 0xf];
129 }
1e80e044
JS
130 *buf = '\0';
131
0fcfd160
LT
132 return buffer;
133}
134
ace1534d
JH
135static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
136{
137 int i;
138 for (i = 0; i < 20; i++) {
139 static char hex[] = "0123456789abcdef";
140 unsigned int val = sha1[i];
141 char *pos = pathbuf + i*2 + (i > 0);
142 *pos++ = hex[val >> 4];
143 *pos = hex[val & 0xf];
144 }
145}
146
0fcfd160
LT
147/*
148 * NOTE! This returns a statically allocated buffer, so you have to be
9befac47 149 * careful about using it. Do a "xstrdup()" if you need to save the
0fcfd160 150 * filename.
ace1534d
JH
151 *
152 * Also note that this returns the location for creating. Reading
153 * SHA1 file can happen from any alternate directory listed in the
d19938ab 154 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 155 * the primary object database.
0fcfd160
LT
156 */
157char *sha1_file_name(const unsigned char *sha1)
158{
0fcfd160
LT
159 static char *name, *base;
160
161 if (!base) {
d19938ab 162 const char *sha1_file_directory = get_object_directory();
0fcfd160 163 int len = strlen(sha1_file_directory);
812666c8 164 base = xmalloc(len + 60);
0fcfd160
LT
165 memcpy(base, sha1_file_directory, len);
166 memset(base+len, 0, 60);
167 base[len] = '/';
168 base[len+3] = '/';
169 name = base + len + 1;
170 }
ace1534d 171 fill_sha1_path(name, sha1);
0fcfd160
LT
172 return base;
173}
174
bf592c50
DB
175char *sha1_pack_name(const unsigned char *sha1)
176{
177 static const char hex[] = "0123456789abcdef";
178 static char *name, *base, *buf;
179 int i;
180
181 if (!base) {
182 const char *sha1_file_directory = get_object_directory();
183 int len = strlen(sha1_file_directory);
184 base = xmalloc(len + 60);
185 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
186 name = base + len + 11;
187 }
188
189 buf = name;
190
191 for (i = 0; i < 20; i++) {
192 unsigned int val = *sha1++;
193 *buf++ = hex[val >> 4];
194 *buf++ = hex[val & 0xf];
195 }
a6080a0a 196
bf592c50
DB
197 return base;
198}
199
200char *sha1_pack_index_name(const unsigned char *sha1)
201{
202 static const char hex[] = "0123456789abcdef";
203 static char *name, *base, *buf;
204 int i;
205
206 if (!base) {
207 const char *sha1_file_directory = get_object_directory();
208 int len = strlen(sha1_file_directory);
209 base = xmalloc(len + 60);
210 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
211 name = base + len + 11;
212 }
213
214 buf = name;
215
216 for (i = 0; i < 20; i++) {
217 unsigned int val = *sha1++;
218 *buf++ = hex[val >> 4];
219 *buf++ = hex[val & 0xf];
220 }
a6080a0a 221
bf592c50
DB
222 return base;
223}
224
d5a63b99
JH
225struct alternate_object_database *alt_odb_list;
226static struct alternate_object_database **alt_odb_tail;
ace1534d 227
c2f493a4
MW
228static void read_info_alternates(const char * alternates, int depth);
229
ddd5d056
JH
230/*
231 * Prepare alternate object database registry.
d5a63b99
JH
232 *
233 * The variable alt_odb_list points at the list of struct
234 * alternate_object_database. The elements on this list come from
235 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
236 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
237 * whose contents is similar to that environment variable but can be
238 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
239 * contains "/the/directory/corresponding/to/.git/objects/...", while
240 * its name points just after the slash at the end of ".git/objects/"
241 * in the example above, and has enough space to hold 40-byte hex
242 * SHA1, an extra slash for the first level indirection, and the
243 * terminating NUL.
ddd5d056 244 */
c2f493a4 245static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 246{
c2f493a4 247 struct stat st;
1494e038 248 const char *objdir = get_object_directory();
c2f493a4
MW
249 struct alternate_object_database *ent;
250 struct alternate_object_database *alt;
251 /* 43 = 40-byte + 2 '/' + terminating NUL */
252 int pfxlen = len;
253 int entlen = pfxlen + 43;
ccfd3e99 254 int base_len = -1;
d5a63b99 255
c2f493a4
MW
256 if (*entry != '/' && relative_base) {
257 /* Relative alt-odb */
258 if (base_len < 0)
259 base_len = strlen(relative_base) + 1;
260 entlen += base_len;
261 pfxlen += base_len;
262 }
263 ent = xmalloc(sizeof(*ent) + entlen);
264
265 if (*entry != '/' && relative_base) {
266 memcpy(ent->base, relative_base, base_len - 1);
267 ent->base[base_len - 1] = '/';
268 memcpy(ent->base + base_len, entry, len);
269 }
270 else
271 memcpy(ent->base, entry, pfxlen);
272
273 ent->name = ent->base + pfxlen + 1;
274 ent->base[pfxlen + 3] = '/';
275 ent->base[pfxlen] = ent->base[entlen-1] = 0;
276
277 /* Detect cases where alternate disappeared */
278 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
279 error("object directory %s does not exist; "
280 "check .git/objects/info/alternates.",
281 ent->base);
282 free(ent);
283 return -1;
284 }
285
286 /* Prevent the common mistake of listing the same
287 * thing twice, or object directory itself.
288 */
289 for (alt = alt_odb_list; alt; alt = alt->next) {
290 if (!memcmp(ent->base, alt->base, pfxlen)) {
291 free(ent);
292 return -1;
293 }
294 }
295 if (!memcmp(ent->base, objdir, pfxlen)) {
296 free(ent);
297 return -1;
298 }
299
300 /* add the alternate entry */
301 *alt_odb_tail = ent;
302 alt_odb_tail = &(ent->next);
303 ent->next = NULL;
304
305 /* recursively add alternates */
306 read_info_alternates(ent->base, depth + 1);
307
308 ent->base[pfxlen] = '/';
309
310 return 0;
311}
312
313static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
314 const char *relative_base, int depth)
315{
316 const char *cp, *last;
317
318 if (depth > 5) {
319 error("%s: ignoring alternate object stores, nesting too deep.",
320 relative_base);
321 return;
322 }
323
d5a63b99 324 last = alt;
9577e7e3
JH
325 while (last < ep) {
326 cp = last;
327 if (cp < ep && *cp == '#') {
328 while (cp < ep && *cp != sep)
329 cp++;
330 last = cp + 1;
331 continue;
332 }
c2f493a4
MW
333 while (cp < ep && *cp != sep)
334 cp++;
d5a63b99 335 if (last != cp) {
c2f493a4
MW
336 if ((*last != '/') && depth) {
337 error("%s: ignoring relative alternate object store %s",
338 relative_base, last);
339 } else {
340 link_alt_odb_entry(last, cp - last,
341 relative_base, depth);
1494e038 342 }
d5a63b99 343 }
9577e7e3 344 while (cp < ep && *cp == sep)
d5a63b99
JH
345 cp++;
346 last = cp;
9577e7e3 347 }
d5a63b99
JH
348}
349
c2f493a4 350static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 351{
9577e7e3 352 char *map;
dc49cd76 353 size_t mapsz;
d5a63b99 354 struct stat st;
9cb18f56
JM
355 const char alt_file_name[] = "info/alternates";
356 /* Given that relative_base is no longer than PATH_MAX,
357 ensure that "path" has enough space to append "/", the
358 file name, "info/alternates", and a trailing NUL. */
359 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 360 int fd;
d5a63b99 361
9cb18f56 362 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
363 fd = open(path, O_RDONLY);
364 if (fd < 0)
365 return;
366 if (fstat(fd, &st) || (st.st_size == 0)) {
367 close(fd);
9a217f2a 368 return;
ace1534d 369 }
dc49cd76
SP
370 mapsz = xsize_t(st.st_size);
371 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 372 close(fd);
d5a63b99 373
dc49cd76 374 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 375
dc49cd76 376 munmap(map, mapsz);
ace1534d
JH
377}
378
c2f493a4
MW
379void prepare_alt_odb(void)
380{
554fe20d 381 const char *alt;
c2f493a4 382
7dc24aa5
SP
383 if (alt_odb_tail)
384 return;
385
c2f493a4
MW
386 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
387 if (!alt) alt = "";
388
c2f493a4
MW
389 alt_odb_tail = &alt_odb_list;
390 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
391
392 read_info_alternates(get_object_directory(), 0);
393}
394
ace1534d
JH
395static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
396{
ace1534d 397 char *name = sha1_file_name(sha1);
d5a63b99 398 struct alternate_object_database *alt;
ace1534d
JH
399
400 if (!stat(name, st))
401 return name;
9a217f2a 402 prepare_alt_odb();
d5a63b99
JH
403 for (alt = alt_odb_list; alt; alt = alt->next) {
404 name = alt->name;
ace1534d 405 fill_sha1_path(name, sha1);
d5a63b99
JH
406 if (!stat(alt->base, st))
407 return alt->base;
ace1534d
JH
408 }
409 return NULL;
410}
411
60bb8b14 412static unsigned int pack_used_ctr;
a53128b6
SP
413static unsigned int pack_mmap_calls;
414static unsigned int peak_pack_open_windows;
415static unsigned int pack_open_windows;
416static size_t peak_pack_mapped;
60bb8b14 417static size_t pack_mapped;
9a217f2a 418struct packed_git *packed_git;
1f688557 419
b79d18c9 420void pack_report(void)
a53128b6
SP
421{
422 fprintf(stderr,
e05db0fd
PR
423 "pack_report: getpagesize() = %10" SZ_FMT "\n"
424 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
425 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
78a28df9 426 (size_t) getpagesize(),
a53128b6
SP
427 packed_git_window_size,
428 packed_git_limit);
429 fprintf(stderr,
430 "pack_report: pack_used_ctr = %10u\n"
431 "pack_report: pack_mmap_calls = %10u\n"
432 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
433 "pack_report: pack_mapped = "
434 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
435 pack_used_ctr,
436 pack_mmap_calls,
437 pack_open_windows, peak_pack_open_windows,
438 pack_mapped, peak_pack_mapped);
439}
440
42873078 441static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
442{
443 void *idx_map;
42873078 444 struct pack_idx_header *hdr;
dc49cd76 445 size_t idx_size;
74e34e1f 446 uint32_t version, nr, i, *index;
e93ec6f9 447 int fd = open(path, O_RDONLY);
1f688557 448 struct stat st;
42873078 449
1f688557
JH
450 if (fd < 0)
451 return -1;
452 if (fstat(fd, &st)) {
453 close(fd);
454 return -1;
455 }
dc49cd76 456 idx_size = xsize_t(st.st_size);
2d88451b
SP
457 if (idx_size < 4 * 256 + 20 + 20) {
458 close(fd);
459 return error("index file %s is too small", path);
460 }
c4712e45 461 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 462 close(fd);
1f688557 463
42873078
NP
464 hdr = idx_map;
465 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
466 version = ntohl(hdr->idx_version);
467 if (version < 2 || version > 2) {
468 munmap(idx_map, idx_size);
469 return error("index file %s is version %d"
470 " and is not supported by this binary"
471 " (try upgrading GIT to a newer version)",
472 path, version);
473 }
474 } else
475 version = 1;
df1b059d 476
1f688557 477 nr = 0;
42873078 478 index = idx_map;
74e34e1f
NP
479 if (version > 1)
480 index += 2; /* skip index header */
1f688557 481 for (i = 0; i < 256; i++) {
326bf396 482 uint32_t n = ntohl(index[i]);
2d88451b
SP
483 if (n < nr) {
484 munmap(idx_map, idx_size);
df1b059d 485 return error("non-monotonic index %s", path);
2d88451b 486 }
1f688557
JH
487 nr = n;
488 }
489
74e34e1f
NP
490 if (version == 1) {
491 /*
492 * Total size:
493 * - 256 index entries 4 bytes each
494 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
495 * - 20-byte SHA1 of the packfile
496 * - 20-byte SHA1 file checksum
497 */
498 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
499 munmap(idx_map, idx_size);
eef427a0 500 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
501 }
502 } else if (version == 2) {
503 /*
504 * Minimum size:
505 * - 8 bytes of header
506 * - 256 index entries 4 bytes each
507 * - 20-byte sha1 entry * nr
508 * - 4-byte crc entry * nr
509 * - 4-byte offset entry * nr
510 * - 20-byte SHA1 of the packfile
511 * - 20-byte SHA1 file checksum
512 * And after the 4-byte offset table might be a
513 * variable sized table containing 8-byte entries
514 * for offsets larger than 2^31.
515 */
516 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
517 unsigned long max_size = min_size;
518 if (nr)
519 max_size += (nr - 1)*8;
520 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 521 munmap(idx_map, idx_size);
eef427a0 522 return error("wrong index v2 file size in %s", path);
74e34e1f
NP
523 }
524 if (idx_size != min_size) {
525 /* make sure we can deal with large pack offsets */
526 off_t x = 0x7fffffffUL, y = 0xffffffffUL;
527 if (x > (x + 1) || y > (y + 1)) {
528 munmap(idx_map, idx_size);
529 return error("pack too large for current definition of off_t in %s", path);
530 }
531 }
2d88451b 532 }
1f688557 533
74e34e1f 534 p->index_version = version;
42873078
NP
535 p->index_data = idx_map;
536 p->index_size = idx_size;
57059091 537 p->num_objects = nr;
1f688557
JH
538 return 0;
539}
540
bc8e478a 541int open_pack_index(struct packed_git *p)
d079837e
SP
542{
543 char *idx_name;
544 int ret;
545
546 if (p->index_data)
547 return 0;
548
549 idx_name = xstrdup(p->pack_name);
550 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
551 ret = check_packed_git_idx(idx_name, p);
552 free(idx_name);
553 return ret;
554}
555
11daf39b
SP
556static void scan_windows(struct packed_git *p,
557 struct packed_git **lru_p,
558 struct pack_window **lru_w,
559 struct pack_window **lru_l)
1f688557 560{
11daf39b
SP
561 struct pack_window *w, *w_l;
562
563 for (w_l = NULL, w = p->windows; w; w = w->next) {
564 if (!w->inuse_cnt) {
565 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
566 *lru_p = p;
567 *lru_w = w;
568 *lru_l = w_l;
54044bf8 569 }
54044bf8 570 }
11daf39b 571 w_l = w;
f9253394 572 }
11daf39b
SP
573}
574
d1efefa4 575static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
576{
577 struct packed_git *p, *lru_p = NULL;
578 struct pack_window *lru_w = NULL, *lru_l = NULL;
579
580 if (current)
581 scan_windows(current, &lru_p, &lru_w, &lru_l);
582 for (p = packed_git; p; p = p->next)
583 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
584 if (lru_p) {
585 munmap(lru_w->base, lru_w->len);
586 pack_mapped -= lru_w->len;
587 if (lru_l)
588 lru_l->next = lru_w->next;
589 else {
590 lru_p->windows = lru_w->next;
d1efefa4 591 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
592 close(lru_p->pack_fd);
593 lru_p->pack_fd = -1;
594 }
595 }
596 free(lru_w);
a53128b6 597 pack_open_windows--;
54044bf8
SP
598 return 1;
599 }
600 return 0;
f9253394
JH
601}
602
d1efefa4 603void release_pack_memory(size_t need, int fd)
97bfeb34
SP
604{
605 size_t cur = pack_mapped;
d1efefa4 606 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
607 ; /* nothing */
608}
609
03e79c88 610void unuse_pack(struct pack_window **w_cursor)
f9253394 611{
03e79c88
SP
612 struct pack_window *w = *w_cursor;
613 if (w) {
614 w->inuse_cnt--;
615 *w_cursor = NULL;
616 }
1f688557
JH
617}
618
3cf8b462
SP
619/*
620 * Do not call this directly as this leaks p->pack_fd on error return;
621 * call open_packed_git() instead.
622 */
623static int open_packed_git_1(struct packed_git *p)
1f688557 624{
9bc879c1
SP
625 struct stat st;
626 struct pack_header hdr;
627 unsigned char sha1[20];
628 unsigned char *idx_sha1;
2c039da8 629 long fd_flag;
9bc879c1 630
d079837e
SP
631 if (!p->index_data && open_pack_index(p))
632 return error("packfile %s index unavailable", p->pack_name);
633
9bc879c1
SP
634 p->pack_fd = open(p->pack_name, O_RDONLY);
635 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 636 return -1;
9bc879c1
SP
637
638 /* If we created the struct before we had the pack we lack size. */
bf592c50 639 if (!p->pack_size) {
bf592c50 640 if (!S_ISREG(st.st_mode))
072db278 641 return error("packfile %s not a regular file", p->pack_name);
bf592c50 642 p->pack_size = st.st_size;
9bc879c1 643 } else if (p->pack_size != st.st_size)
072db278 644 return error("packfile %s size changed", p->pack_name);
9bc879c1 645
2c039da8
JH
646 /* We leave these file descriptors open with sliding mmap;
647 * there is no point keeping them open across exec(), though.
648 */
649 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
650 if (fd_flag < 0)
072db278 651 return error("cannot determine file descriptor flags");
2c039da8
JH
652 fd_flag |= FD_CLOEXEC;
653 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 654 return error("cannot set FD_CLOEXEC");
2c039da8 655
9bc879c1 656 /* Verify we recognize this pack file format. */
e6e2bd62 657 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 658 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 659 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 660 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 661 if (!pack_version_ok(hdr.hdr_version))
072db278 662 return error("packfile %s is version %u and not supported"
9bc879c1
SP
663 " (try upgrading GIT to a newer version)",
664 p->pack_name, ntohl(hdr.hdr_version));
665
666 /* Verify the pack matches its index. */
57059091 667 if (p->num_objects != ntohl(hdr.hdr_entries))
072db278 668 return error("packfile %s claims to have %u objects"
57059091
NP
669 " while index indicates %u objects",
670 p->pack_name, ntohl(hdr.hdr_entries),
671 p->num_objects);
9bc879c1 672 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 673 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 674 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 675 return error("packfile %s signature is unavailable", p->pack_name);
42873078 676 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 677 if (hashcmp(sha1, idx_sha1))
072db278
SP
678 return error("packfile %s does not match index", p->pack_name);
679 return 0;
9bc879c1
SP
680}
681
3cf8b462
SP
682static int open_packed_git(struct packed_git *p)
683{
684 if (!open_packed_git_1(p))
685 return 0;
686 if (p->pack_fd != -1) {
687 close(p->pack_fd);
688 p->pack_fd = -1;
689 }
690 return -1;
691}
692
c4001d92 693static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
694{
695 /* We must promise at least 20 bytes (one hash) after the
696 * offset is available from this window, otherwise the offset
697 * is not actually in this window and a different window (which
698 * has that one hash excess) must be used. This is to support
699 * the object header and delta base parsing routines below.
700 */
701 off_t win_off = win->offset;
702 return win_off <= offset
703 && (offset + 20) <= (win_off + win->len);
704}
705
03e79c88
SP
706unsigned char* use_pack(struct packed_git *p,
707 struct pack_window **w_cursor,
c4001d92 708 off_t offset,
03e79c88 709 unsigned int *left)
9bc879c1 710{
60bb8b14 711 struct pack_window *win = *w_cursor;
03e79c88 712
072db278
SP
713 if (p->pack_fd == -1 && open_packed_git(p))
714 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
715
716 /* Since packfiles end in a hash of their content and its
717 * pointless to ask for an offset into the middle of that
718 * hash, and the in_window function above wouldn't match
719 * don't allow an offset too close to the end of the file.
720 */
721 if (offset > (p->pack_size - 20))
722 die("offset beyond end of packfile (truncated pack?)");
723
724 if (!win || !in_window(win, offset)) {
725 if (win)
726 win->inuse_cnt--;
727 for (win = p->windows; win; win = win->next) {
728 if (in_window(win, offset))
729 break;
730 }
731 if (!win) {
78a28df9 732 size_t window_align = packed_git_window_size / 2;
dc49cd76 733 off_t len;
60bb8b14 734 win = xcalloc(1, sizeof(*win));
78a28df9 735 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
736 len = p->pack_size - win->offset;
737 if (len > packed_git_window_size)
738 len = packed_git_window_size;
739 win->len = (size_t)len;
60bb8b14 740 pack_mapped += win->len;
11daf39b 741 while (packed_git_limit < pack_mapped
d1efefa4 742 && unuse_one_window(p, p->pack_fd))
60bb8b14 743 ; /* nothing */
c4712e45 744 win->base = xmmap(NULL, win->len,
60bb8b14
SP
745 PROT_READ, MAP_PRIVATE,
746 p->pack_fd, win->offset);
747 if (win->base == MAP_FAILED)
73b4e4be
SP
748 die("packfile %s cannot be mapped: %s",
749 p->pack_name,
750 strerror(errno));
a53128b6
SP
751 pack_mmap_calls++;
752 pack_open_windows++;
753 if (pack_mapped > peak_pack_mapped)
754 peak_pack_mapped = pack_mapped;
755 if (pack_open_windows > peak_pack_open_windows)
756 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
757 win->next = p->windows;
758 p->windows = win;
759 }
1f688557 760 }
03e79c88
SP
761 if (win != *w_cursor) {
762 win->last_used = pack_used_ctr++;
763 win->inuse_cnt++;
764 *w_cursor = win;
765 }
60bb8b14 766 offset -= win->offset;
03e79c88 767 if (left)
dc49cd76 768 *left = win->len - xsize_t(offset);
03e79c88 769 return win->base + offset;
1f688557
JH
770}
771
42873078 772struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
773{
774 struct stat st;
42873078 775 struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
1f688557 776
42873078
NP
777 /*
778 * Make sure a corresponding .pack file exists and that
779 * the index looks sane.
780 */
781 path_len -= strlen(".idx");
782 if (path_len < 1)
1f688557 783 return NULL;
42873078
NP
784 memcpy(p->pack_name, path, path_len);
785 strcpy(p->pack_name + path_len, ".pack");
d079837e 786 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 787 free(p);
1f688557
JH
788 return NULL;
789 }
42873078 790
1f688557
JH
791 /* ok, it looks sane as far as we can check without
792 * actually mapping the pack file.
793 */
d079837e
SP
794 p->index_version = 0;
795 p->index_data = NULL;
796 p->index_size = 0;
797 p->num_objects = 0;
1f688557 798 p->pack_size = st.st_size;
1f688557 799 p->next = NULL;
c41ee586 800 p->windows = NULL;
9bc879c1 801 p->pack_fd = -1;
9d835df2 802 p->pack_local = local;
b867092f 803 p->mtime = st.st_mtime;
42873078
NP
804 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
805 hashclr(p->sha1);
1f688557
JH
806 return p;
807}
808
bf592c50 809struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
810{
811 char *path = sha1_pack_index_name(sha1);
812 return parse_pack_index_file(sha1, path);
813}
814
42873078
NP
815struct packed_git *parse_pack_index_file(const unsigned char *sha1,
816 const char *idx_path)
bf592c50 817{
42873078
NP
818 const char *path = sha1_pack_name(sha1);
819 struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
bf592c50 820
42873078
NP
821 if (check_packed_git_idx(idx_path, p)) {
822 free(p);
bf592c50 823 return NULL;
42873078 824 }
bf592c50 825
bf592c50 826 strcpy(p->pack_name, path);
bf592c50 827 p->pack_size = 0;
bf592c50 828 p->next = NULL;
c41ee586 829 p->windows = NULL;
9bc879c1 830 p->pack_fd = -1;
e702496e 831 hashcpy(p->sha1, sha1);
bf592c50
DB
832 return p;
833}
834
835void install_packed_git(struct packed_git *pack)
836{
837 pack->next = packed_git;
838 packed_git = pack;
839}
840
9d835df2 841static void prepare_packed_git_one(char *objdir, int local)
1f688557 842{
9cb18f56
JM
843 /* Ensure that this buffer is large enough so that we can
844 append "/pack/" without clobbering the stack even if
845 strlen(objdir) were PATH_MAX. */
846 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
847 int len;
848 DIR *dir;
849 struct dirent *de;
850
851 sprintf(path, "%s/pack", objdir);
852 len = strlen(path);
853 dir = opendir(path);
b5b16990 854 if (!dir) {
26125f6b 855 if (errno != ENOENT)
bd2afde8 856 error("unable to open object pack directory: %s: %s",
26125f6b 857 path, strerror(errno));
1f688557 858 return;
b5b16990 859 }
1f688557
JH
860 path[len++] = '/';
861 while ((de = readdir(dir)) != NULL) {
862 int namelen = strlen(de->d_name);
863 struct packed_git *p;
864
5bb1cda5 865 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
866 continue;
867
9cb18f56
JM
868 if (len + namelen + 1 > sizeof(path))
869 continue;
870
54a15a8d 871 /* Don't reopen a pack we already have. */
1f688557 872 strcpy(path + len, de->d_name);
86f7780c
JK
873 for (p = packed_git; p; p = p->next) {
874 if (!memcmp(path, p->pack_name, len + namelen - 4))
875 break;
876 }
877 if (p)
878 continue;
54a15a8d
SP
879 /* See if it really is a valid .idx file with corresponding
880 * .pack file that we can map.
881 */
9d835df2 882 p = add_packed_git(path, len + namelen, local);
1f688557
JH
883 if (!p)
884 continue;
625e9421 885 install_packed_git(p);
1f688557 886 }
5b35bcd5 887 closedir(dir);
1f688557
JH
888}
889
b867092f
JH
890static int sort_pack(const void *a_, const void *b_)
891{
892 struct packed_git *a = *((struct packed_git **)a_);
893 struct packed_git *b = *((struct packed_git **)b_);
894 int st;
895
896 /*
897 * Local packs tend to contain objects specific to our
898 * variant of the project than remote ones. In addition,
899 * remote ones could be on a network mounted filesystem.
900 * Favor local ones for these reasons.
901 */
902 st = a->pack_local - b->pack_local;
903 if (st)
904 return -st;
905
906 /*
907 * Younger packs tend to contain more recent objects,
908 * and more recent objects tend to get accessed more
909 * often.
910 */
911 if (a->mtime < b->mtime)
912 return 1;
913 else if (a->mtime == b->mtime)
914 return 0;
915 return -1;
916}
917
918static void rearrange_packed_git(void)
919{
920 struct packed_git **ary, *p;
921 int i, n;
922
923 for (n = 0, p = packed_git; p; p = p->next)
924 n++;
925 if (n < 2)
926 return;
927
928 /* prepare an array of packed_git for easier sorting */
929 ary = xcalloc(n, sizeof(struct packed_git *));
930 for (n = 0, p = packed_git; p; p = p->next)
931 ary[n++] = p;
932
933 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
934
935 /* link them back again */
936 for (i = 0; i < n - 1; i++)
937 ary[i]->next = ary[i + 1];
938 ary[n - 1]->next = NULL;
939 packed_git = ary[0];
940
941 free(ary);
942}
943
637cdd9d 944static int prepare_packed_git_run_once = 0;
9a217f2a 945void prepare_packed_git(void)
1f688557 946{
d5a63b99 947 struct alternate_object_database *alt;
1f688557 948
637cdd9d 949 if (prepare_packed_git_run_once)
1f688557 950 return;
9d835df2 951 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 952 prepare_alt_odb();
d5a63b99 953 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 954 alt->name[-1] = 0;
9d835df2 955 prepare_packed_git_one(alt->base, 0);
1494e038 956 alt->name[-1] = '/';
1f688557 957 }
b867092f 958 rearrange_packed_git();
637cdd9d
JK
959 prepare_packed_git_run_once = 1;
960}
961
fc04c412 962void reprepare_packed_git(void)
637cdd9d
JK
963{
964 prepare_packed_git_run_once = 0;
965 prepare_packed_git();
1f688557
JH
966}
967
5d6ccf5c 968int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
969{
970 unsigned char real_sha1[20];
7cfb5f36 971 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 972 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
973}
974
4175e9e3 975static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 976{
0fcfd160
LT
977 struct stat st;
978 void *map;
144bde78 979 int fd;
ace1534d
JH
980 char *filename = find_sha1_file(sha1, &st);
981
982 if (!filename) {
ace1534d
JH
983 return NULL;
984 }
0fcfd160 985
144bde78 986 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 987 if (fd < 0) {
144bde78
LT
988 /* See if it works without O_NOATIME */
989 switch (sha1_file_open_flag) {
990 default:
991 fd = open(filename, O_RDONLY);
992 if (fd >= 0)
993 break;
994 /* Fallthrough */
995 case 0:
144bde78
LT
996 return NULL;
997 }
998
1f688557
JH
999 /* If it failed once, it will probably fail again.
1000 * Stop using O_NOATIME
1001 */
144bde78 1002 sha1_file_open_flag = 0;
0fcfd160 1003 }
dc49cd76
SP
1004 *size = xsize_t(st.st_size);
1005 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
0fcfd160 1006 close(fd);
0fcfd160
LT
1007 return map;
1008}
1009
726f852b 1010static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1011{
1012 unsigned int word;
1013
1014 /*
1015 * Is it a zlib-compressed buffer? If so, the first byte
1016 * must be 0x78 (15-bit window size, deflated), and the
1017 * first 16-bit word is evenly divisible by 31
1018 */
1019 word = (map[0] << 8) + map[1];
1020 if (map[0] == 0x78 && !(word % 31))
1021 return 1;
1022 else
1023 return 0;
1024}
1025
72518e9c 1026unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1027{
ad1ed5ee 1028 unsigned shift;
93821bd9 1029 unsigned char c;
93821bd9 1030 unsigned long size;
ad1ed5ee
JH
1031 unsigned long used = 0;
1032
1033 c = buf[used++];
1034 *type = (c >> 4) & 7;
1035 size = c & 15;
1036 shift = 4;
1037 while (c & 0x80) {
1038 if (len <= used)
1039 return 0;
1040 if (sizeof(long) * 8 <= shift)
1041 return 0;
1042 c = buf[used++];
1043 size += (c & 0x7f) << shift;
1044 shift += 7;
1045 }
1046 *sizep = size;
1047 return used;
1048}
1049
1050static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1051{
1052 unsigned long size, used;
1053 static const char valid_loose_object_type[8] = {
1054 0, /* OBJ_EXT */
1055 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1056 0, /* "delta" and others are invalid in a loose object */
93821bd9 1057 };
ad1ed5ee 1058 enum object_type type;
93821bd9 1059
c4483576
LT
1060 /* Get the data stream */
1061 memset(stream, 0, sizeof(*stream));
1062 stream->next_in = map;
1063 stream->avail_in = mapsize;
1064 stream->next_out = buffer;
93821bd9
LT
1065 stream->avail_out = bufsiz;
1066
bb6b8e4f 1067 if (legacy_loose_object(map)) {
93821bd9
LT
1068 inflateInit(stream);
1069 return inflate(stream, 0);
1070 }
1071
726f852b
NP
1072
1073 /*
1074 * There used to be a second loose object header format which
1075 * was meant to mimic the in-pack format, allowing for direct
1076 * copy of the object data. This format turned up not to be
1077 * really worth it and we don't write it any longer. But we
1078 * can still read it.
1079 */
ad1ed5ee
JH
1080 used = unpack_object_header_gently(map, mapsize, &type, &size);
1081 if (!used || !valid_loose_object_type[type])
93821bd9 1082 return -1;
ad1ed5ee
JH
1083 map += used;
1084 mapsize -= used;
93821bd9
LT
1085
1086 /* Set up the stream for the rest.. */
1087 stream->next_in = map;
1088 stream->avail_in = mapsize;
c4483576 1089 inflateInit(stream);
93821bd9
LT
1090
1091 /* And generate the fake traditional header */
ad1ed5ee 1092 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1093 typename(type), size);
93821bd9 1094 return 0;
c4483576
LT
1095}
1096
7efbff75 1097static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1098{
1099 int bytes = strlen(buffer) + 1;
d565b341 1100 unsigned char *buf = xmalloc(1+size);
93821bd9 1101 unsigned long n;
7efbff75 1102 int status = Z_OK;
5180cacc 1103
93821bd9
LT
1104 n = stream->total_out - bytes;
1105 if (n > size)
1106 n = size;
1107 memcpy(buf, (char *) buffer + bytes, n);
1108 bytes = n;
456cdf6e
LT
1109 if (bytes <= size) {
1110 /*
1111 * The above condition must be (bytes <= size), not
1112 * (bytes < size). In other words, even though we
1113 * expect no more output and set avail_out to zer0,
1114 * the input zlib stream may have bytes that express
1115 * "this concludes the stream", and we *do* want to
1116 * eat that input.
1117 *
1118 * Otherwise we would not be able to test that we
1119 * consumed all the input to reach the expected size;
1120 * we also want to check that zlib tells us that all
1121 * went well with status == Z_STREAM_END at the end.
1122 */
5180cacc
LT
1123 stream->next_out = buf + bytes;
1124 stream->avail_out = size - bytes;
7efbff75
JH
1125 while (status == Z_OK)
1126 status = inflate(stream, Z_FINISH);
5180cacc
LT
1127 }
1128 buf[size] = 0;
456cdf6e 1129 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1130 inflateEnd(stream);
1131 return buf;
1132 }
1133
1134 if (status < 0)
1135 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1136 else if (stream->avail_in)
1137 error("garbage at end of loose object '%s'",
1138 sha1_to_hex(sha1));
1139 free(buf);
1140 return NULL;
5180cacc
LT
1141}
1142
1143/*
1144 * We used to just use "sscanf()", but that's actually way
1145 * too permissive for what we want to check. So do an anal
1146 * object header parse by hand.
1147 */
21666f1a 1148static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1149{
21666f1a 1150 char type[10];
5180cacc
LT
1151 int i;
1152 unsigned long size;
1153
1154 /*
a6080a0a 1155 * The type can be at most ten bytes (including the
5180cacc 1156 * terminating '\0' that we add), and is followed by
21666f1a 1157 * a space.
5180cacc 1158 */
21666f1a 1159 i = 0;
5180cacc
LT
1160 for (;;) {
1161 char c = *hdr++;
1162 if (c == ' ')
1163 break;
21666f1a
NP
1164 type[i++] = c;
1165 if (i >= sizeof(type))
5180cacc 1166 return -1;
5180cacc 1167 }
21666f1a 1168 type[i] = 0;
5180cacc
LT
1169
1170 /*
1171 * The length must follow immediately, and be in canonical
1172 * decimal format (ie "010" is not valid).
1173 */
1174 size = *hdr++ - '0';
1175 if (size > 9)
1176 return -1;
1177 if (size) {
1178 for (;;) {
1179 unsigned long c = *hdr - '0';
1180 if (c > 9)
1181 break;
1182 hdr++;
1183 size = size * 10 + c;
1184 }
1185 }
1186 *sizep = size;
1187
1188 /*
1189 * The length must be followed by a zero byte
1190 */
21666f1a 1191 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1192}
1193
7efbff75 1194static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1195{
5180cacc 1196 int ret;
0fcfd160 1197 z_stream stream;
5180cacc 1198 char hdr[8192];
0fcfd160 1199
5180cacc 1200 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1201 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1202 return NULL;
1203
7efbff75 1204 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1205}
1206
54dab52a
NP
1207unsigned long get_size_from_delta(struct packed_git *p,
1208 struct pack_window **w_curs,
1209 off_t curpos)
1210{
1211 const unsigned char *data;
1212 unsigned char delta_head[20], *in;
1213 z_stream stream;
1214 int st;
1215
1216 memset(&stream, 0, sizeof(stream));
1217 stream.next_out = delta_head;
1218 stream.avail_out = sizeof(delta_head);
1219
1220 inflateInit(&stream);
1221 do {
1222 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1223 stream.next_in = in;
1224 st = inflate(&stream, Z_FINISH);
1225 curpos += stream.next_in - in;
1226 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1227 stream.total_out < sizeof(delta_head));
1228 inflateEnd(&stream);
1229 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1230 die("delta data unpack-initial failed");
1231
1232 /* Examine the initial part of the delta to figure out
1233 * the result size.
1234 */
1235 data = delta_head;
1236
1237 /* ignore base size */
1238 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1239
1240 /* Read the result size */
1241 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1242}
1243
c4001d92 1244static off_t get_delta_base(struct packed_git *p,
03e79c88 1245 struct pack_window **w_curs,
c4001d92 1246 off_t *curpos,
21666f1a 1247 enum object_type type,
c4001d92 1248 off_t delta_obj_offset)
eb32d236 1249{
2b87c45b 1250 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1251 off_t base_offset;
eb32d236 1252
8d8a4ea5
SP
1253 /* use_pack() assured us we have [base_info, base_info + 20)
1254 * as a range that we can look at without walking off the
1255 * end of the mapped window. Its actually the hash size
1256 * that is assured. An OFS_DELTA longer than the hash size
1257 * is stupid, as then a REF_DELTA would be smaller to store.
1258 */
21666f1a 1259 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1260 unsigned used = 0;
1261 unsigned char c = base_info[used++];
1262 base_offset = c & 127;
1263 while (c & 128) {
1264 base_offset += 1;
8723f216 1265 if (!base_offset || MSB(base_offset, 7))
eb32d236
NP
1266 die("offset value overflow for delta base object");
1267 c = base_info[used++];
1268 base_offset = (base_offset << 7) + (c & 127);
1269 }
1270 base_offset = delta_obj_offset - base_offset;
1271 if (base_offset >= delta_obj_offset)
1272 die("delta base offset out of bound");
2b87c45b 1273 *curpos += used;
21666f1a 1274 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1275 /* The base entry _must_ be in the same pack */
1276 base_offset = find_pack_entry_one(base_info, p);
1277 if (!base_offset)
1278 die("failed to find delta-pack base object %s",
1279 sha1_to_hex(base_info));
2b87c45b 1280 *curpos += 20;
eb32d236
NP
1281 } else
1282 die("I am totally screwed");
2b87c45b 1283 return base_offset;
eb32d236
NP
1284}
1285
f3bf9224 1286/* forward declaration for a mutually recursive function */
c4001d92 1287static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1288 unsigned long *sizep);
f3bf9224 1289
43057304 1290static int packed_delta_info(struct packed_git *p,
03e79c88 1291 struct pack_window **w_curs,
c4001d92 1292 off_t curpos,
21666f1a 1293 enum object_type type,
c4001d92 1294 off_t obj_offset,
43057304 1295 unsigned long *sizep)
5db47c2b 1296{
c4001d92 1297 off_t base_offset;
f3bf9224 1298
21666f1a
NP
1299 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1300 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1301
c62266f3
JH
1302 /* We choose to only get the type of the base object and
1303 * ignore potentially corrupt pack file that expects the delta
1304 * based on a base with a wrong size. This saves tons of
1305 * inflate() calls.
1306 */
54dab52a
NP
1307 if (sizep)
1308 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1309
1310 return type;
5db47c2b
JH
1311}
1312
2b87c45b
NP
1313static int unpack_object_header(struct packed_git *p,
1314 struct pack_window **w_curs,
c4001d92 1315 off_t *curpos,
2b87c45b 1316 unsigned long *sizep)
a733cb60 1317{
03e79c88
SP
1318 unsigned char *base;
1319 unsigned int left;
ad1ed5ee 1320 unsigned long used;
2b87c45b 1321 enum object_type type;
a733cb60 1322
8d8a4ea5
SP
1323 /* use_pack() assures us we have [base, base + 20) available
1324 * as a range that we can look at at. (Its actually the hash
3dff5379 1325 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1326 * the maximum deflated object size is 2^137, which is just
1327 * insane, so we know won't exceed what we have been given.
1328 */
2b87c45b
NP
1329 base = use_pack(p, w_curs, *curpos, &left);
1330 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1331 if (!used)
1332 die("object offset outside of pack file");
2b87c45b 1333 *curpos += used;
ad1ed5ee 1334
2b87c45b 1335 return type;
a733cb60
LT
1336}
1337
21666f1a 1338const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1339 off_t obj_offset,
21666f1a
NP
1340 unsigned long *size,
1341 unsigned long *store_size,
1342 unsigned int *delta_chain_length,
1343 unsigned char *base_sha1)
ad8c80a5 1344{
03e79c88 1345 struct pack_window *w_curs = NULL;
c4001d92
SP
1346 off_t curpos;
1347 unsigned long dummy;
43057304 1348 unsigned char *next_sha1;
21666f1a 1349 enum object_type type;
ad8c80a5 1350
43057304 1351 *delta_chain_length = 0;
2b87c45b 1352 curpos = obj_offset;
21666f1a 1353 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304
NP
1354
1355 for (;;) {
21666f1a 1356 switch (type) {
43057304 1357 default:
08a19d87 1358 die("pack %s contains unknown object type %d",
21666f1a 1359 p->pack_name, type);
43057304
NP
1360 case OBJ_COMMIT:
1361 case OBJ_TREE:
1362 case OBJ_BLOB:
1363 case OBJ_TAG:
43057304 1364 *store_size = 0; /* notyet */
03e79c88 1365 unuse_pack(&w_curs);
21666f1a 1366 return typename(type);
eb32d236 1367 case OBJ_OFS_DELTA:
21666f1a 1368 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
eb32d236 1369 if (*delta_chain_length == 0) {
2b87c45b 1370 /* TODO: find base_sha1 as pointed by curpos */
30fee062 1371 hashclr(base_sha1);
eb32d236
NP
1372 }
1373 break;
1374 case OBJ_REF_DELTA:
2b87c45b 1375 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1376 if (*delta_chain_length == 0)
1377 hashcpy(base_sha1, next_sha1);
2b87c45b 1378 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1379 break;
1380 }
43057304 1381 (*delta_chain_length)++;
2b87c45b 1382 curpos = obj_offset;
21666f1a 1383 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1384 }
ad8c80a5
JH
1385}
1386
c4001d92 1387static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1388 unsigned long *sizep)
1f688557 1389{
03e79c88 1390 struct pack_window *w_curs = NULL;
c4001d92
SP
1391 unsigned long size;
1392 off_t curpos = obj_offset;
21666f1a 1393 enum object_type type;
5db47c2b 1394
21666f1a 1395 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1396
21666f1a 1397 switch (type) {
eb32d236
NP
1398 case OBJ_OFS_DELTA:
1399 case OBJ_REF_DELTA:
21666f1a
NP
1400 type = packed_delta_info(p, &w_curs, curpos,
1401 type, obj_offset, sizep);
2b87c45b 1402 break;
a733cb60 1403 case OBJ_COMMIT:
a733cb60 1404 case OBJ_TREE:
a733cb60 1405 case OBJ_BLOB:
a733cb60 1406 case OBJ_TAG:
2b87c45b
NP
1407 if (sizep)
1408 *sizep = size;
a69d0943 1409 break;
1f688557 1410 default:
08a19d87 1411 die("pack %s contains unknown object type %d",
21666f1a 1412 p->pack_name, type);
1f688557 1413 }
2b87c45b 1414 unuse_pack(&w_curs);
21666f1a 1415 return type;
1f688557
JH
1416}
1417
eb950c19 1418static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1419 struct pack_window **w_curs,
c4001d92 1420 off_t curpos,
eb950c19 1421 unsigned long size)
de530aaa
SP
1422{
1423 int st;
1424 z_stream stream;
079afb18 1425 unsigned char *buffer, *in;
de530aaa
SP
1426
1427 buffer = xmalloc(size + 1);
1428 buffer[size] = 0;
1429 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1430 stream.next_out = buffer;
1431 stream.avail_out = size;
1432
1433 inflateInit(&stream);
079afb18 1434 do {
2b87c45b 1435 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1436 stream.next_in = in;
1437 st = inflate(&stream, Z_FINISH);
2b87c45b 1438 curpos += stream.next_in - in;
079afb18 1439 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1440 inflateEnd(&stream);
1441 if ((st != Z_STREAM_END) || stream.total_out != size) {
1442 free(buffer);
1443 return NULL;
1444 }
1445
1446 return buffer;
1447}
1448
e5e01619
LT
1449#define MAX_DELTA_CACHE (256)
1450
18bdec11 1451static size_t delta_base_cached;
5e08ecbf
NP
1452
1453static struct delta_base_cache_lru_list {
1454 struct delta_base_cache_lru_list *prev;
1455 struct delta_base_cache_lru_list *next;
1456} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1457
e5e01619 1458static struct delta_base_cache_entry {
5e08ecbf
NP
1459 struct delta_base_cache_lru_list lru;
1460 void *data;
e5e01619
LT
1461 struct packed_git *p;
1462 off_t base_offset;
1463 unsigned long size;
e5e01619
LT
1464 enum object_type type;
1465} delta_base_cache[MAX_DELTA_CACHE];
1466
1467static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1468{
1469 unsigned long hash;
1470
1471 hash = (unsigned long)p + (unsigned long)base_offset;
1472 hash += (hash >> 8) + (hash >> 16);
3358004a 1473 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1474}
1475
62f255ad 1476static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1477 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1478{
e5e01619
LT
1479 void *ret;
1480 unsigned long hash = pack_entry_hash(p, base_offset);
1481 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1482
1483 ret = ent->data;
1484 if (ret && ent->p == p && ent->base_offset == base_offset)
1485 goto found_cache_entry;
62f255ad 1486 return unpack_entry(p, base_offset, type, base_size);
e5e01619
LT
1487
1488found_cache_entry:
18bdec11 1489 if (!keep_cache) {
a0cba108 1490 ent->data = NULL;
5e08ecbf
NP
1491 ent->lru.next->prev = ent->lru.prev;
1492 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1493 delta_base_cached -= ent->size;
1494 }
a0cba108
NP
1495 else {
1496 ret = xmalloc(ent->size + 1);
1497 memcpy(ret, ent->data, ent->size);
1498 ((char *)ret)[ent->size] = 0;
1499 }
e5e01619
LT
1500 *type = ent->type;
1501 *base_size = ent->size;
1502 return ret;
62f255ad
LT
1503}
1504
18bdec11
SP
1505static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1506{
1507 if (ent->data) {
1508 free(ent->data);
1509 ent->data = NULL;
5e08ecbf
NP
1510 ent->lru.next->prev = ent->lru.prev;
1511 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1512 delta_base_cached -= ent->size;
1513 }
1514}
1515
62f255ad
LT
1516static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1517 void *base, unsigned long base_size, enum object_type type)
1518{
5e08ecbf 1519 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1520 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1521 struct delta_base_cache_lru_list *lru;
e5e01619 1522
18bdec11
SP
1523 release_delta_base_cache(ent);
1524 delta_base_cached += base_size;
5e08ecbf
NP
1525
1526 for (lru = delta_base_cache_lru.next;
1527 delta_base_cached > delta_base_cache_limit
1528 && lru != &delta_base_cache_lru;
1529 lru = lru->next) {
1530 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1531 if (f->type == OBJ_BLOB)
1532 release_delta_base_cache(f);
1533 }
5e08ecbf
NP
1534 for (lru = delta_base_cache_lru.next;
1535 delta_base_cached > delta_base_cache_limit
1536 && lru != &delta_base_cache_lru;
1537 lru = lru->next) {
1538 struct delta_base_cache_entry *f = (void *)lru;
1539 release_delta_base_cache(f);
1540 }
18bdec11 1541
e5e01619
LT
1542 ent->p = p;
1543 ent->base_offset = base_offset;
1544 ent->type = type;
1545 ent->data = base;
1546 ent->size = base_size;
5e08ecbf
NP
1547 ent->lru.next = &delta_base_cache_lru;
1548 ent->lru.prev = delta_base_cache_lru.prev;
1549 delta_base_cache_lru.prev->next = &ent->lru;
1550 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1551}
1552
eb950c19 1553static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1554 struct pack_window **w_curs,
c4001d92 1555 off_t curpos,
1f688557 1556 unsigned long delta_size,
c4001d92 1557 off_t obj_offset,
21666f1a 1558 enum object_type *type,
eb950c19 1559 unsigned long *sizep)
1f688557 1560{
7c3e8be3 1561 void *delta_data, *result, *base;
c4001d92
SP
1562 unsigned long base_size;
1563 off_t base_offset;
43057304 1564
21666f1a 1565 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
a0cba108 1566 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
67686d95 1567 if (!base)
c4001d92
SP
1568 die("failed to read delta base object"
1569 " at %"PRIuMAX" from %s",
1570 (uintmax_t)base_offset, p->pack_name);
67686d95 1571
2b87c45b 1572 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
9064d87b
SP
1573 if (!delta_data)
1574 die("failed to unpack compressed delta"
1575 " at %"PRIuMAX" from %s",
1576 (uintmax_t)curpos, p->pack_name);
1f688557
JH
1577 result = patch_delta(base, base_size,
1578 delta_data, delta_size,
21666f1a 1579 sizep);
1f688557
JH
1580 if (!result)
1581 die("failed to apply delta");
1582 free(delta_data);
62f255ad 1583 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1584 return result;
1585}
1586
c4001d92 1587void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1588 enum object_type *type, unsigned long *sizep)
1f688557 1589{
03e79c88 1590 struct pack_window *w_curs = NULL;
c4001d92 1591 off_t curpos = obj_offset;
21666f1a 1592 void *data;
1f688557 1593
21666f1a
NP
1594 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1595 switch (*type) {
eb32d236
NP
1596 case OBJ_OFS_DELTA:
1597 case OBJ_REF_DELTA:
21666f1a
NP
1598 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1599 obj_offset, type, sizep);
4d703a1a 1600 break;
a733cb60 1601 case OBJ_COMMIT:
a733cb60 1602 case OBJ_TREE:
a733cb60 1603 case OBJ_BLOB:
a733cb60 1604 case OBJ_TAG:
21666f1a 1605 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1606 break;
1f688557 1607 default:
21666f1a 1608 die("unknown object type %i in %s", *type, p->pack_name);
1f688557 1609 }
03e79c88 1610 unuse_pack(&w_curs);
21666f1a 1611 return data;
1f688557
JH
1612}
1613
d079837e 1614const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1615 uint32_t n)
9a217f2a 1616{
42873078 1617 const unsigned char *index = p->index_data;
d079837e
SP
1618 if (!index) {
1619 if (open_pack_index(p))
1620 return NULL;
1621 index = p->index_data;
1622 }
57059091 1623 if (n >= p->num_objects)
d72308e0 1624 return NULL;
74e34e1f
NP
1625 index += 4 * 256;
1626 if (p->index_version == 1) {
1627 return index + 24 * n + 4;
1628 } else {
1629 index += 8;
1630 return index + 20 * n;
1631 }
1632}
1633
1634static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1635{
1636 const unsigned char *index = p->index_data;
1637 index += 4 * 256;
1638 if (p->index_version == 1) {
1639 return ntohl(*((uint32_t *)(index + 24 * n)));
1640 } else {
1641 uint32_t off;
1642 index += 8 + p->num_objects * (20 + 4);
1643 off = ntohl(*((uint32_t *)(index + 4 * n)));
1644 if (!(off & 0x80000000))
1645 return off;
1646 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1647 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1648 ntohl(*((uint32_t *)(index + 4)));
1649 }
9a217f2a
JH
1650}
1651
c4001d92 1652off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1653 struct packed_git *p)
1f688557 1654{
42873078 1655 const uint32_t *level1_ofs = p->index_data;
42873078 1656 const unsigned char *index = p->index_data;
74e34e1f 1657 unsigned hi, lo;
42873078 1658
d079837e
SP
1659 if (!index) {
1660 if (open_pack_index(p))
1661 return 0;
1662 level1_ofs = p->index_data;
1663 index = p->index_data;
1664 }
74e34e1f
NP
1665 if (p->index_version > 1) {
1666 level1_ofs += 2;
1667 index += 8;
1668 }
42873078 1669 index += 4 * 256;
74e34e1f
NP
1670 hi = ntohl(level1_ofs[*sha1]);
1671 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1f688557
JH
1672
1673 do {
74e34e1f
NP
1674 unsigned mi = (lo + hi) / 2;
1675 unsigned x = (p->index_version > 1) ? (mi * 20) : (mi * 24 + 4);
1676 int cmp = hashcmp(index + x, sha1);
43057304 1677 if (!cmp)
74e34e1f 1678 return nth_packed_object_offset(p, mi);
1f688557
JH
1679 if (cmp > 0)
1680 hi = mi;
1681 else
1682 lo = mi+1;
1683 } while (lo < hi);
1684 return 0;
1685}
1686
d4ff6d92
SP
1687static int matches_pack_name(struct packed_git *p, const char *ig)
1688{
1689 const char *last_c, *c;
1690
1691 if (!strcmp(p->pack_name, ig))
1692 return 0;
1693
1694 for (c = p->pack_name, last_c = c; *c;)
1695 if (*c == '/')
1696 last_c = ++c;
1697 else
1698 ++c;
1699 if (!strcmp(last_c, ig))
1700 return 0;
1701
1702 return 1;
1703}
1704
106d710b 1705static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1706{
f7c22cc6 1707 static struct packed_git *last_found = (void *)1;
1f688557 1708 struct packed_git *p;
c4001d92 1709 off_t offset;
43057304 1710
1f688557 1711 prepare_packed_git();
f7c22cc6
NP
1712 if (!packed_git)
1713 return 0;
1714 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1715
f7c22cc6 1716 do {
106d710b
JH
1717 if (ignore_packed) {
1718 const char **ig;
1719 for (ig = ignore_packed; *ig; ig++)
d4ff6d92 1720 if (!matches_pack_name(p, *ig))
106d710b
JH
1721 break;
1722 if (*ig)
f7c22cc6 1723 goto next;
106d710b 1724 }
f7c22cc6 1725
43057304
NP
1726 offset = find_pack_entry_one(sha1, p);
1727 if (offset) {
c715f783
SP
1728 /*
1729 * We are about to tell the caller where they can
1730 * locate the requested object. We better make
1731 * sure the packfile is still here and can be
1732 * accessed before supplying that answer, as
1733 * it may have been deleted since the index
1734 * was loaded!
1735 */
1736 if (p->pack_fd == -1 && open_packed_git(p)) {
1737 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1738 goto next;
c715f783 1739 }
43057304
NP
1740 e->offset = offset;
1741 e->p = p;
1742 hashcpy(e->sha1, sha1);
f7c22cc6 1743 last_found = p;
1f688557 1744 return 1;
43057304 1745 }
f7c22cc6
NP
1746
1747 next:
1748 if (p == last_found)
1749 p = packed_git;
1750 else
1751 p = p->next;
1752 if (p == last_found)
1753 p = p->next;
1754 } while (p);
1f688557
JH
1755 return 0;
1756}
1757
a6080a0a 1758struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1759 struct packed_git *packs)
1760{
1761 struct packed_git *p;
bf592c50
DB
1762
1763 for (p = packs; p; p = p->next) {
43057304 1764 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1765 return p;
1766 }
1767 return NULL;
21666f1a 1768
bf592c50
DB
1769}
1770
21666f1a 1771static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1772{
36e4d74a 1773 int status;
65c2e0c3
JH
1774 unsigned long mapsize, size;
1775 void *map;
1776 z_stream stream;
d65a16f6 1777 char hdr[32];
65c2e0c3 1778
bb6b8e4f 1779 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1780 if (!map)
1781 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1782 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1783 status = error("unable to unpack %s header",
1784 sha1_to_hex(sha1));
21666f1a 1785 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1786 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1787 else if (sizep)
1788 *sizep = size;
65c2e0c3
JH
1789 inflateEnd(&stream);
1790 munmap(map, mapsize);
1791 return status;
1792}
1793
21666f1a 1794int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1795{
f0df4ed5
JS
1796 struct pack_entry e;
1797
1798 if (!find_pack_entry(sha1, &e, NULL)) {
1799 reprepare_packed_git();
1800 if (!find_pack_entry(sha1, &e, NULL))
21666f1a 1801 return sha1_loose_object_info(sha1, sizep);
f0df4ed5 1802 }
21666f1a 1803 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1804}
1805
21666f1a
NP
1806static void *read_packed_sha1(const unsigned char *sha1,
1807 enum object_type *type, unsigned long *size)
1f688557
JH
1808{
1809 struct pack_entry e;
1810
8276c007 1811 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1812 return NULL;
8276c007 1813 else
a0cba108 1814 return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1f688557
JH
1815}
1816
d66b37bb
JH
1817/*
1818 * This is meant to hold a *small* number of objects that you would
1819 * want read_sha1_file() to be able to return, but yet you do not want
1820 * to write them into the object store (e.g. a browse-only
1821 * application).
1822 */
1823static struct cached_object {
1824 unsigned char sha1[20];
21666f1a 1825 enum object_type type;
d66b37bb
JH
1826 void *buf;
1827 unsigned long size;
1828} *cached_objects;
1829static int cached_object_nr, cached_object_alloc;
1830
1831static struct cached_object *find_cached_object(const unsigned char *sha1)
1832{
1833 int i;
1834 struct cached_object *co = cached_objects;
1835
1836 for (i = 0; i < cached_object_nr; i++, co++) {
1837 if (!hashcmp(co->sha1, sha1))
1838 return co;
1839 }
1840 return NULL;
1841}
1842
21666f1a
NP
1843int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1844 unsigned char *sha1)
d66b37bb
JH
1845{
1846 struct cached_object *co;
1847
21666f1a 1848 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
1849 if (has_sha1_file(sha1) || find_cached_object(sha1))
1850 return 0;
1851 if (cached_object_alloc <= cached_object_nr) {
1852 cached_object_alloc = alloc_nr(cached_object_alloc);
1853 cached_objects = xrealloc(cached_objects,
1854 sizeof(*cached_objects) *
1855 cached_object_alloc);
1856 }
1857 co = &cached_objects[cached_object_nr++];
1858 co->size = len;
21666f1a 1859 co->type = type;
efa13f7b
JH
1860 co->buf = xmalloc(len);
1861 memcpy(co->buf, buf, len);
d66b37bb
JH
1862 hashcpy(co->sha1, sha1);
1863 return 0;
1864}
1865
21666f1a
NP
1866void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
1867 unsigned long *size)
0fcfd160
LT
1868{
1869 unsigned long mapsize;
1870 void *map, *buf;
d66b37bb
JH
1871 struct cached_object *co;
1872
1873 co = find_cached_object(sha1);
1874 if (co) {
1875 buf = xmalloc(co->size + 1);
1876 memcpy(buf, co->buf, co->size);
1877 ((char*)buf)[co->size] = 0;
21666f1a 1878 *type = co->type;
d66b37bb
JH
1879 *size = co->size;
1880 return buf;
1881 }
0fcfd160 1882
8276c007
PE
1883 buf = read_packed_sha1(sha1, type, size);
1884 if (buf)
1885 return buf;
bb6b8e4f 1886 map = map_sha1_file(sha1, &mapsize);
0fcfd160 1887 if (map) {
7efbff75 1888 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
1889 munmap(map, mapsize);
1890 return buf;
1891 }
637cdd9d 1892 reprepare_packed_git();
8276c007 1893 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
1894}
1895
40469ee9 1896void *read_object_with_reference(const unsigned char *sha1,
21666f1a 1897 const char *required_type_name,
40469ee9
JH
1898 unsigned long *size,
1899 unsigned char *actual_sha1_return)
f4913f91 1900{
21666f1a 1901 enum object_type type, required_type;
f4913f91
JH
1902 void *buffer;
1903 unsigned long isize;
40469ee9 1904 unsigned char actual_sha1[20];
f4913f91 1905
21666f1a 1906 required_type = type_from_string(required_type_name);
e702496e 1907 hashcpy(actual_sha1, sha1);
40469ee9
JH
1908 while (1) {
1909 int ref_length = -1;
1910 const char *ref_type = NULL;
f4913f91 1911
21666f1a 1912 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
1913 if (!buffer)
1914 return NULL;
21666f1a 1915 if (type == required_type) {
40469ee9
JH
1916 *size = isize;
1917 if (actual_sha1_return)
e702496e 1918 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1919 return buffer;
1920 }
1921 /* Handle references */
21666f1a 1922 else if (type == OBJ_COMMIT)
40469ee9 1923 ref_type = "tree ";
21666f1a 1924 else if (type == OBJ_TAG)
40469ee9
JH
1925 ref_type = "object ";
1926 else {
1927 free(buffer);
1928 return NULL;
1929 }
1930 ref_length = strlen(ref_type);
f4913f91 1931
40469ee9 1932 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1933 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1934 free(buffer);
1935 return NULL;
1936 }
1cf58e72 1937 free(buffer);
40469ee9
JH
1938 /* Now we have the ID of the referred-to object in
1939 * actual_sha1. Check again. */
f4913f91 1940 }
f4913f91
JH
1941}
1942
ce9fbf16 1943static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 1944 const char *type, unsigned char *sha1,
d65a16f6 1945 char *hdr, int *hdrlen)
d410c0f5
JH
1946{
1947 SHA_CTX c;
1948
1949 /* Generate the header */
d65a16f6 1950 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
1951
1952 /* Sha1.. */
1953 SHA1_Init(&c);
1954 SHA1_Update(&c, hdr, *hdrlen);
1955 SHA1_Update(&c, buf, len);
1956 SHA1_Final(sha1, &c);
d410c0f5
JH
1957}
1958
230f1322
LT
1959/*
1960 * Link the tempfile to the final place, possibly creating the
1961 * last directory level as you do so.
1962 *
1963 * Returns the errno on failure, 0 on success.
1964 */
839837b9 1965static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1966{
1967 int ret;
756aaf4a 1968 char *dir;
230f1322
LT
1969
1970 if (!link(tmpfile, filename))
1971 return 0;
1972
1973 /*
756aaf4a 1974 * Try to mkdir the last path component if that failed.
230f1322
LT
1975 *
1976 * Re-try the "link()" regardless of whether the mkdir
1977 * succeeds, since a race might mean that somebody
1978 * else succeeded.
1979 */
1980 ret = errno;
756aaf4a
SP
1981 dir = strrchr(filename, '/');
1982 if (dir) {
1983 *dir = 0;
866cae0d 1984 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
91c23e48 1985 *dir = '/';
756aaf4a 1986 return -2;
91c23e48 1987 }
756aaf4a
SP
1988 *dir = '/';
1989 if (!link(tmpfile, filename))
1990 return 0;
1991 ret = errno;
230f1322
LT
1992 }
1993 return ret;
1994}
1995
1996/*
1997 * Move the just written object into its final resting place
1998 */
839837b9 1999int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
2000{
2001 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
2002
2003 /*
2004 * Coda hack - coda doesn't like cross-directory links,
2005 * so we fall back to a rename, which will mean that it
2006 * won't be able to check collisions, but that's not a
2007 * big deal.
2008 *
2009 * The same holds for FAT formatted media.
2010 *
2011 * When this succeeds, we just return 0. We have nothing
2012 * left to unlink.
2013 */
2014 if (ret && ret != EEXIST) {
2015 if (!rename(tmpfile, filename))
230f1322 2016 return 0;
9e48b389 2017 ret = errno;
230f1322
LT
2018 }
2019 unlink(tmpfile);
2020 if (ret) {
2021 if (ret != EEXIST) {
916d081b 2022 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2023 }
2024 /* FIXME!!! Collision check here ? */
2025 }
2026
2027 return 0;
2028}
2029
4d548150
LT
2030static int write_buffer(int fd, const void *buf, size_t len)
2031{
d34cf19b 2032 if (write_in_full(fd, buf, len) < 0)
93822c22 2033 return error("file write error (%s)", strerror(errno));
4d548150
LT
2034 return 0;
2035}
2036
ce9fbf16 2037int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2038 unsigned char *sha1)
2039{
d65a16f6 2040 char hdr[32];
abdc3fc8
RS
2041 int hdrlen;
2042 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2043 return 0;
2044}
2045
bf0f910d 2046int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160 2047{
ac54c277 2048 int size, ret;
bf0f910d 2049 unsigned char *compressed;
0fcfd160
LT
2050 z_stream stream;
2051 unsigned char sha1[20];
706bc531 2052 char *filename;
aac17941 2053 static char tmpfile[PATH_MAX];
d65a16f6 2054 char hdr[32];
230f1322 2055 int fd, hdrlen;
a44c9a5e 2056
d410c0f5
JH
2057 /* Normally if we have it in the pack then we do not bother writing
2058 * it out into .git/objects/??/?{38} file.
2059 */
972a9155
RS
2060 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2061 filename = sha1_file_name(sha1);
706bc531 2062 if (returnsha1)
e702496e 2063 hashcpy(returnsha1, sha1);
d410c0f5
JH
2064 if (has_sha1_file(sha1))
2065 return 0;
aac17941
LT
2066 fd = open(filename, O_RDONLY);
2067 if (fd >= 0) {
706bc531 2068 /*
aac17941
LT
2069 * FIXME!!! We might do collision checking here, but we'd
2070 * need to uncompress the old file and check it. Later.
706bc531 2071 */
aac17941 2072 close(fd);
706bc531
LT
2073 return 0;
2074 }
2075
aac17941 2076 if (errno != ENOENT) {
916d081b 2077 return error("sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
2078 }
2079
0e55181f 2080 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
ace1534d 2081
aac17941
LT
2082 fd = mkstemp(tmpfile);
2083 if (fd < 0) {
916d081b
PB
2084 if (errno == EPERM)
2085 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2086 else
2087 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2088 }
2089
0fcfd160
LT
2090 /* Set it up */
2091 memset(&stream, 0, sizeof(stream));
12f6c308 2092 deflateInit(&stream, zlib_compression_level);
93821bd9 2093 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2094 compressed = xmalloc(size);
0fcfd160
LT
2095
2096 /* Compress it */
0fcfd160
LT
2097 stream.next_out = compressed;
2098 stream.avail_out = size;
a44c9a5e
LT
2099
2100 /* First header.. */
d65a16f6 2101 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2102 stream.avail_in = hdrlen;
726f852b
NP
2103 while (deflate(&stream, 0) == Z_OK)
2104 /* nothing */;
a44c9a5e
LT
2105
2106 /* Then the data itself.. */
2107 stream.next_in = buf;
2108 stream.avail_in = len;
ac54c277
LT
2109 ret = deflate(&stream, Z_FINISH);
2110 if (ret != Z_STREAM_END)
2111 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2112
2113 ret = deflateEnd(&stream);
2114 if (ret != Z_OK)
2115 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2116
0fcfd160
LT
2117 size = stream.total_out;
2118
4d548150
LT
2119 if (write_buffer(fd, compressed, size) < 0)
2120 die("unable to write sha1 file");
aac17941 2121 fchmod(fd, 0444);
e82973cf
JH
2122 if (close(fd))
2123 die("unable to write sha1 file");
383f85b7 2124 free(compressed);
0fcfd160 2125
230f1322 2126 return move_temp_to_file(tmpfile, filename);
0fcfd160 2127}
8237b185 2128
4d548150
LT
2129/*
2130 * We need to unpack and recompress the object for writing
2131 * it out to a different file.
2132 */
2133static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 2134{
4d548150 2135 size_t size;
a5eda52b 2136 z_stream stream;
4d548150
LT
2137 unsigned char *unpacked;
2138 unsigned long len;
21666f1a 2139 enum object_type type;
d65a16f6 2140 char hdr[32];
4d548150
LT
2141 int hdrlen;
2142 void *buf;
bfc66daf 2143
a9486b02 2144 /* need to unpack and recompress it by itself */
21666f1a 2145 unpacked = read_packed_sha1(sha1, &type, &len);
8276c007
PE
2146 if (!unpacked)
2147 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
a5eda52b 2148
21666f1a 2149 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
a5eda52b 2150
4d548150
LT
2151 /* Set it up */
2152 memset(&stream, 0, sizeof(stream));
12f6c308 2153 deflateInit(&stream, zlib_compression_level);
4d548150
LT
2154 size = deflateBound(&stream, len + hdrlen);
2155 buf = xmalloc(size);
a5eda52b 2156
4d548150
LT
2157 /* Compress it */
2158 stream.next_out = buf;
2159 stream.avail_out = size;
a5eda52b 2160
4d548150
LT
2161 /* First header.. */
2162 stream.next_in = (void *)hdr;
2163 stream.avail_in = hdrlen;
2164 while (deflate(&stream, 0) == Z_OK)
2165 /* nothing */;
bfc66daf 2166
4d548150
LT
2167 /* Then the data itself.. */
2168 stream.next_in = unpacked;
2169 stream.avail_in = len;
2170 while (deflate(&stream, Z_FINISH) == Z_OK)
2171 /* nothing */;
2172 deflateEnd(&stream);
2173 free(unpacked);
bfc66daf 2174
4d548150
LT
2175 *objsize = stream.total_out;
2176 return buf;
2177}
2178
2179int write_sha1_to_fd(int fd, const unsigned char *sha1)
2180{
2181 int retval;
2182 unsigned long objsize;
bb6b8e4f 2183 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
2184
2185 if (buf) {
2186 retval = write_buffer(fd, buf, objsize);
2187 munmap(buf, objsize);
2188 return retval;
2189 }
2190
2191 buf = repack_object(sha1, &objsize);
2192 retval = write_buffer(fd, buf, objsize);
2193 free(buf);
2194 return retval;
a5eda52b
DB
2195}
2196
70b9829e
DB
2197int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
2198 size_t bufsize, size_t *bufposn)
8237b185 2199{
230f1322 2200 char tmpfile[PATH_MAX];
8237b185
DB
2201 int local;
2202 z_stream stream;
2203 unsigned char real_sha1[20];
bf0f910d 2204 unsigned char discard[4096];
8237b185
DB
2205 int ret;
2206 SHA_CTX c;
2207
0e55181f 2208 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
8237b185 2209
230f1322 2210 local = mkstemp(tmpfile);
916d081b
PB
2211 if (local < 0) {
2212 if (errno == EPERM)
2213 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2214 else
2215 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2216 }
8237b185
DB
2217
2218 memset(&stream, 0, sizeof(stream));
2219
2220 inflateInit(&stream);
2221
2222 SHA1_Init(&c);
2223
2224 do {
2225 ssize_t size;
70b9829e
DB
2226 if (*bufposn) {
2227 stream.avail_in = *bufposn;
96ad15ae 2228 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
2229 do {
2230 stream.next_out = discard;
2231 stream.avail_out = sizeof(discard);
2232 ret = inflate(&stream, Z_SYNC_FLUSH);
2233 SHA1_Update(&c, discard, sizeof(discard) -
2234 stream.avail_out);
2235 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
2236 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
2237 die("unable to write sha1 file");
70b9829e
DB
2238 memmove(buffer, buffer + *bufposn - stream.avail_in,
2239 stream.avail_in);
2240 *bufposn = stream.avail_in;
2241 if (ret != Z_OK)
2242 break;
2243 }
93d26e4c 2244 size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
2245 if (size <= 0) {
2246 close(local);
230f1322 2247 unlink(tmpfile);
8237b185
DB
2248 if (!size)
2249 return error("Connection closed?");
2250 perror("Reading from connection");
2251 return -1;
2252 }
70b9829e
DB
2253 *bufposn += size;
2254 } while (1);
8237b185
DB
2255 inflateEnd(&stream);
2256
b5b8d814 2257 fchmod(local, 0444);
0d315468
JM
2258 if (close(local) != 0)
2259 die("unable to write sha1 file");
8237b185
DB
2260 SHA1_Final(real_sha1, &c);
2261 if (ret != Z_STREAM_END) {
230f1322 2262 unlink(tmpfile);
8237b185
DB
2263 return error("File %s corrupted", sha1_to_hex(sha1));
2264 }
a89fccd2 2265 if (hashcmp(sha1, real_sha1)) {
230f1322 2266 unlink(tmpfile);
bd2afde8 2267 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 2268 }
230f1322
LT
2269
2270 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
2271}
2272
bf592c50
DB
2273int has_pack_index(const unsigned char *sha1)
2274{
2275 struct stat st;
2276 if (stat(sha1_pack_index_name(sha1), &st))
2277 return 0;
2278 return 1;
2279}
2280
2281int has_pack_file(const unsigned char *sha1)
2282{
2283 struct stat st;
2284 if (stat(sha1_pack_name(sha1), &st))
2285 return 0;
2286 return 1;
2287}
2288
106d710b 2289int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2290{
2291 struct pack_entry e;
106d710b 2292 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2293}
2294
8237b185
DB
2295int has_sha1_file(const unsigned char *sha1)
2296{
8237b185 2297 struct stat st;
1f688557
JH
2298 struct pack_entry e;
2299
106d710b 2300 if (find_pack_entry(sha1, &e, NULL))
1f688557 2301 return 1;
ab90ea5d 2302 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 2303}
74400e71 2304
e7332f96
BE
2305/*
2306 * reads from fd as long as possible into a supplied buffer of size bytes.
82e5a82f 2307 * If necessary the buffer's size is increased using realloc()
e7332f96
BE
2308 *
2309 * returns 0 if anything went fine and -1 otherwise
2310 *
c4fba0a3
CR
2311 * The buffer is always NUL-terminated, not including it in returned size.
2312 *
e7332f96
BE
2313 * NOTE: both buf and size may change, but even when -1 is returned
2314 * you still have to free() it yourself.
2315 */
c4fba0a3 2316int read_fd(int fd, char **return_buf, unsigned long *return_size)
024510c8 2317{
c4fba0a3 2318 char *buf = *return_buf;
e7332f96 2319 unsigned long size = *return_size;
8a912bcb 2320 ssize_t iret;
024510c8 2321 unsigned long off = 0;
e7332f96 2322
c4fba0a3
CR
2323 if (!buf || size <= 1) {
2324 size = 1024;
2325 buf = xrealloc(buf, size);
2326 }
2327
024510c8 2328 do {
c4fba0a3 2329 iret = xread(fd, buf + off, (size - 1) - off);
024510c8
DB
2330 if (iret > 0) {
2331 off += iret;
c4fba0a3
CR
2332 if (off == size - 1) {
2333 size = alloc_nr(size);
83572c1a 2334 buf = xrealloc(buf, size);
024510c8
DB
2335 }
2336 }
2337 } while (iret > 0);
e7332f96 2338
c4fba0a3
CR
2339 buf[off] = '\0';
2340
e7332f96
BE
2341 *return_buf = buf;
2342 *return_size = off;
2343
2344 if (iret < 0)
2345 return -1;
2346 return 0;
2347}
2348
2349int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2350{
2351 unsigned long size = 4096;
2d7320d0 2352 char *buf = xmalloc(size);
e7332f96 2353 int ret;
e7332f96 2354
c4fba0a3 2355 if (read_fd(fd, &buf, &size)) {
024510c8
DB
2356 free(buf);
2357 return -1;
2358 }
e7332f96 2359
024510c8 2360 if (!type)
8e440259 2361 type = blob_type;
024510c8 2362 if (write_object)
e7332f96 2363 ret = write_sha1_file(buf, size, type, sha1);
abdc3fc8
RS
2364 else
2365 ret = hash_sha1_file(buf, size, type, sha1);
024510c8
DB
2366 free(buf);
2367 return ret;
2368}
2369
edaec3fb 2370int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
53bca91a 2371 enum object_type type, const char *path)
74400e71 2372{
dc49cd76 2373 size_t size = xsize_t(st->st_size);
3a55602e 2374 void *buf = NULL;
6c510bee 2375 int ret, re_allocated = 0;
74400e71 2376
74400e71 2377 if (size)
c4712e45 2378 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 2379 close(fd);
74400e71 2380
7672db20 2381 if (!type)
edaec3fb 2382 type = OBJ_BLOB;
6c510bee
LT
2383
2384 /*
2385 * Convert blobs to git internal format
2386 */
d0d8e14d 2387 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
6c510bee 2388 unsigned long nsize = size;
ac78e548
AR
2389 char *nbuf = convert_to_git(path, buf, &nsize);
2390 if (nbuf) {
2391 munmap(buf, size);
6c510bee
LT
2392 size = nsize;
2393 buf = nbuf;
2394 re_allocated = 1;
2395 }
2396 }
2397
7672db20 2398 if (write_object)
edaec3fb 2399 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2400 else
edaec3fb 2401 ret = hash_sha1_file(buf, size, typename(type), sha1);
6c510bee
LT
2402 if (re_allocated) {
2403 free(buf);
2404 return ret;
2405 }
aac17941
LT
2406 if (size)
2407 munmap(buf, size);
2408 return ret;
74400e71 2409}
ec1fcc16
JH
2410
2411int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2412{
2413 int fd;
2414 char *target;
dc49cd76 2415 size_t len;
ec1fcc16
JH
2416
2417 switch (st->st_mode & S_IFMT) {
2418 case S_IFREG:
2419 fd = open(path, O_RDONLY);
2420 if (fd < 0)
2421 return error("open(\"%s\"): %s", path,
2422 strerror(errno));
53bca91a 2423 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2424 return error("%s: failed to insert into database",
2425 path);
2426 break;
2427 case S_IFLNK:
dc49cd76
SP
2428 len = xsize_t(st->st_size);
2429 target = xmalloc(len + 1);
2430 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2431 char *errstr = strerror(errno);
2432 free(target);
2433 return error("readlink(\"%s\"): %s", path,
2434 errstr);
2435 }
abdc3fc8 2436 if (!write_object)
dc49cd76
SP
2437 hash_sha1_file(target, len, blob_type, sha1);
2438 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2439 return error("%s: failed to insert into database",
2440 path);
2441 free(target);
2442 break;
f35a6d3b
LT
2443 case S_IFDIR:
2444 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2445 default:
2446 return error("%s: unsupported file type", path);
2447 }
2448 return 0;
2449}
a69e5429
JH
2450
2451int read_pack_header(int fd, struct pack_header *header)
2452{
2453 char *c = (char*)header;
2454 ssize_t remaining = sizeof(struct pack_header);
2455 do {
2456 ssize_t r = xread(fd, c, remaining);
2457 if (r <= 0)
2458 /* "eof before pack header was fully read" */
2459 return PH_ERROR_EOF;
2460 remaining -= r;
2461 c += r;
2462 } while (remaining > 0);
2463 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2464 /* "protocol error (pack signature mismatch detected)" */
2465 return PH_ERROR_PACK_SIGNATURE;
2466 if (!pack_version_ok(header->hdr_version))
2467 /* "protocol error (pack version unsupported)" */
2468 return PH_ERROR_PROTOCOL;
2469 return 0;
2470}