test case for pack resilience against corruptions
[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"
70f5d5d3 17#include "pack-revindex.h"
628522ec 18#include "sha1-lookup.h"
0fcfd160 19
144bde78
LT
20#ifndef O_NOATIME
21#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
22#define O_NOATIME 01000000
23#else
24#define O_NOATIME 0
25#endif
26#endif
27
e05db0fd
PR
28#ifdef NO_C99_FORMAT
29#define SZ_FMT "lu"
9e42d6a1 30static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
e05db0fd
PR
31#else
32#define SZ_FMT "zu"
9e42d6a1 33static size_t sz_fmt(size_t s) { return s; }
e05db0fd
PR
34#endif
35
96f1e58f 36const unsigned char null_sha1[20];
88cd621d 37
192a6be2 38const signed char hexval_table[256] = {
e49521b5
JH
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
42 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
45 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
46 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
47 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
51 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
68 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
69 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
70 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
71};
0fcfd160
LT
72
73int get_sha1_hex(const char *hex, unsigned char *sha1)
74{
75 int i;
76 for (i = 0; i < 20; i++) {
77 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
78 if (val & ~0xff)
79 return -1;
80 *sha1++ = val;
81 hex += 2;
82 }
83 return 0;
84}
85
b2cb9425
JH
86int safe_create_leading_directories(char *path)
87{
88 char *pos = path;
67d42212
JR
89 struct stat st;
90
85dadc38 91 if (is_absolute_path(path))
67ffdf4c 92 pos++;
b2cb9425
JH
93
94 while (pos) {
95 pos = strchr(pos, '/');
96 if (!pos)
97 break;
98 *pos = 0;
67d42212
JR
99 if (!stat(path, &st)) {
100 /* path exists */
101 if (!S_ISDIR(st.st_mode)) {
b2cb9425 102 *pos = '/';
67d42212 103 return -3;
b2cb9425 104 }
457f06d6 105 }
67d42212
JR
106 else if (mkdir(path, 0777)) {
107 *pos = '/';
108 return -1;
109 }
457f06d6
JS
110 else if (adjust_shared_perm(path)) {
111 *pos = '/';
112 return -2;
113 }
b2cb9425
JH
114 *pos++ = '/';
115 }
116 return 0;
117}
723c31fe 118
3bfaf018 119char *sha1_to_hex(const unsigned char *sha1)
0fcfd160 120{
dcb3450f
LT
121 static int bufno;
122 static char hexbuffer[4][50];
0fcfd160 123 static const char hex[] = "0123456789abcdef";
dcb3450f 124 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
125 int i;
126
127 for (i = 0; i < 20; i++) {
128 unsigned int val = *sha1++;
129 *buf++ = hex[val >> 4];
130 *buf++ = hex[val & 0xf];
131 }
1e80e044
JS
132 *buf = '\0';
133
0fcfd160
LT
134 return buffer;
135}
136
ace1534d
JH
137static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
138{
139 int i;
140 for (i = 0; i < 20; i++) {
141 static char hex[] = "0123456789abcdef";
142 unsigned int val = sha1[i];
143 char *pos = pathbuf + i*2 + (i > 0);
144 *pos++ = hex[val >> 4];
145 *pos = hex[val & 0xf];
146 }
147}
148
0fcfd160
LT
149/*
150 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 151 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 152 * filename.
ace1534d
JH
153 *
154 * Also note that this returns the location for creating. Reading
155 * SHA1 file can happen from any alternate directory listed in the
d19938ab 156 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 157 * the primary object database.
0fcfd160
LT
158 */
159char *sha1_file_name(const unsigned char *sha1)
160{
0fcfd160
LT
161 static char *name, *base;
162
163 if (!base) {
d19938ab 164 const char *sha1_file_directory = get_object_directory();
0fcfd160 165 int len = strlen(sha1_file_directory);
812666c8 166 base = xmalloc(len + 60);
0fcfd160
LT
167 memcpy(base, sha1_file_directory, len);
168 memset(base+len, 0, 60);
169 base[len] = '/';
170 base[len+3] = '/';
171 name = base + len + 1;
172 }
ace1534d 173 fill_sha1_path(name, sha1);
0fcfd160
LT
174 return base;
175}
176
633f43e1 177static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 178 char **name, char **base, const char *which)
bf592c50
DB
179{
180 static const char hex[] = "0123456789abcdef";
633f43e1 181 char *buf;
bf592c50
DB
182 int i;
183
633f43e1 184 if (!*base) {
bf592c50
DB
185 const char *sha1_file_directory = get_object_directory();
186 int len = strlen(sha1_file_directory);
633f43e1 187 *base = xmalloc(len + 60);
6eec46bd
JH
188 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
189 sha1_file_directory, which);
633f43e1 190 *name = *base + len + 11;
bf592c50
DB
191 }
192
633f43e1 193 buf = *name;
bf592c50
DB
194
195 for (i = 0; i < 20; i++) {
196 unsigned int val = *sha1++;
197 *buf++ = hex[val >> 4];
198 *buf++ = hex[val & 0xf];
199 }
a6080a0a 200
633f43e1 201 return *base;
bf592c50
DB
202}
203
633f43e1 204char *sha1_pack_name(const unsigned char *sha1)
bf592c50 205{
633f43e1 206 static char *name, *base;
bf592c50 207
6eec46bd 208 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 209}
bf592c50 210
633f43e1
HO
211char *sha1_pack_index_name(const unsigned char *sha1)
212{
213 static char *name, *base;
a6080a0a 214
6eec46bd 215 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
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
85dadc38 249 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
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
85dadc38 258 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
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) {
85dadc38 329 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
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;
dc49cd76 346 size_t mapsz;
d5a63b99 347 struct stat st;
9cb18f56
JM
348 const char alt_file_name[] = "info/alternates";
349 /* Given that relative_base is no longer than PATH_MAX,
350 ensure that "path" has enough space to append "/", the
351 file name, "info/alternates", and a trailing NUL. */
352 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 353 int fd;
d5a63b99 354
9cb18f56 355 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
356 fd = open(path, O_RDONLY);
357 if (fd < 0)
358 return;
359 if (fstat(fd, &st) || (st.st_size == 0)) {
360 close(fd);
9a217f2a 361 return;
ace1534d 362 }
dc49cd76
SP
363 mapsz = xsize_t(st.st_size);
364 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 365 close(fd);
d5a63b99 366
dc49cd76 367 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 368
dc49cd76 369 munmap(map, mapsz);
ace1534d
JH
370}
371
bef70b22
DB
372void add_to_alternates_file(const char *reference)
373{
374 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
375 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), 1);
376 char *alt = mkpath("%s/objects\n", reference);
377 write_or_die(fd, alt, strlen(alt));
378 if (commit_lock_file(lock))
379 die("could not close alternates file");
380 if (alt_odb_tail)
381 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
382}
383
c2f493a4
MW
384void prepare_alt_odb(void)
385{
554fe20d 386 const char *alt;
c2f493a4 387
7dc24aa5
SP
388 if (alt_odb_tail)
389 return;
390
c2f493a4
MW
391 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
392 if (!alt) alt = "";
393
c2f493a4
MW
394 alt_odb_tail = &alt_odb_list;
395 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
396
397 read_info_alternates(get_object_directory(), 0);
398}
399
c529d75a 400static int has_loose_object(const unsigned char *sha1)
ace1534d 401{
ace1534d 402 char *name = sha1_file_name(sha1);
d5a63b99 403 struct alternate_object_database *alt;
ace1534d 404
c529d75a
LT
405 if (!access(name, F_OK))
406 return 1;
9a217f2a 407 prepare_alt_odb();
d5a63b99
JH
408 for (alt = alt_odb_list; alt; alt = alt->next) {
409 name = alt->name;
ace1534d 410 fill_sha1_path(name, sha1);
c529d75a
LT
411 if (!access(alt->base, F_OK))
412 return 1;
ace1534d 413 }
c529d75a 414 return 0;
ace1534d
JH
415}
416
60bb8b14 417static unsigned int pack_used_ctr;
a53128b6
SP
418static unsigned int pack_mmap_calls;
419static unsigned int peak_pack_open_windows;
420static unsigned int pack_open_windows;
421static size_t peak_pack_mapped;
60bb8b14 422static size_t pack_mapped;
9a217f2a 423struct packed_git *packed_git;
1f688557 424
b79d18c9 425void pack_report(void)
a53128b6
SP
426{
427 fprintf(stderr,
e05db0fd
PR
428 "pack_report: getpagesize() = %10" SZ_FMT "\n"
429 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
430 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
431 sz_fmt(getpagesize()),
432 sz_fmt(packed_git_window_size),
433 sz_fmt(packed_git_limit));
a53128b6
SP
434 fprintf(stderr,
435 "pack_report: pack_used_ctr = %10u\n"
436 "pack_report: pack_mmap_calls = %10u\n"
437 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
438 "pack_report: pack_mapped = "
439 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
440 pack_used_ctr,
441 pack_mmap_calls,
442 pack_open_windows, peak_pack_open_windows,
9e42d6a1 443 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
444}
445
42873078 446static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
447{
448 void *idx_map;
42873078 449 struct pack_idx_header *hdr;
dc49cd76 450 size_t idx_size;
74e34e1f 451 uint32_t version, nr, i, *index;
e93ec6f9 452 int fd = open(path, O_RDONLY);
1f688557 453 struct stat st;
42873078 454
1f688557
JH
455 if (fd < 0)
456 return -1;
457 if (fstat(fd, &st)) {
458 close(fd);
459 return -1;
460 }
dc49cd76 461 idx_size = xsize_t(st.st_size);
2d88451b
SP
462 if (idx_size < 4 * 256 + 20 + 20) {
463 close(fd);
464 return error("index file %s is too small", path);
465 }
c4712e45 466 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 467 close(fd);
1f688557 468
42873078
NP
469 hdr = idx_map;
470 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
471 version = ntohl(hdr->idx_version);
472 if (version < 2 || version > 2) {
473 munmap(idx_map, idx_size);
474 return error("index file %s is version %d"
475 " and is not supported by this binary"
476 " (try upgrading GIT to a newer version)",
477 path, version);
478 }
479 } else
480 version = 1;
df1b059d 481
1f688557 482 nr = 0;
42873078 483 index = idx_map;
74e34e1f
NP
484 if (version > 1)
485 index += 2; /* skip index header */
1f688557 486 for (i = 0; i < 256; i++) {
326bf396 487 uint32_t n = ntohl(index[i]);
2d88451b
SP
488 if (n < nr) {
489 munmap(idx_map, idx_size);
df1b059d 490 return error("non-monotonic index %s", path);
2d88451b 491 }
1f688557
JH
492 nr = n;
493 }
494
74e34e1f
NP
495 if (version == 1) {
496 /*
497 * Total size:
498 * - 256 index entries 4 bytes each
499 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
500 * - 20-byte SHA1 of the packfile
501 * - 20-byte SHA1 file checksum
502 */
503 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
504 munmap(idx_map, idx_size);
eef427a0 505 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
506 }
507 } else if (version == 2) {
508 /*
509 * Minimum size:
510 * - 8 bytes of header
511 * - 256 index entries 4 bytes each
512 * - 20-byte sha1 entry * nr
513 * - 4-byte crc entry * nr
514 * - 4-byte offset entry * nr
515 * - 20-byte SHA1 of the packfile
516 * - 20-byte SHA1 file checksum
517 * And after the 4-byte offset table might be a
518 * variable sized table containing 8-byte entries
519 * for offsets larger than 2^31.
520 */
521 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
522 unsigned long max_size = min_size;
523 if (nr)
524 max_size += (nr - 1)*8;
525 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 526 munmap(idx_map, idx_size);
eef427a0 527 return error("wrong index v2 file size in %s", path);
74e34e1f 528 }
7109c889
JH
529 if (idx_size != min_size &&
530 /*
531 * make sure we can deal with large pack offsets.
532 * 31-bit signed offset won't be enough, neither
533 * 32-bit unsigned one will be.
534 */
535 (sizeof(off_t) <= 4)) {
536 munmap(idx_map, idx_size);
537 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 538 }
2d88451b 539 }
1f688557 540
74e34e1f 541 p->index_version = version;
42873078
NP
542 p->index_data = idx_map;
543 p->index_size = idx_size;
57059091 544 p->num_objects = nr;
1f688557
JH
545 return 0;
546}
547
bc8e478a 548int open_pack_index(struct packed_git *p)
d079837e
SP
549{
550 char *idx_name;
551 int ret;
552
553 if (p->index_data)
554 return 0;
555
556 idx_name = xstrdup(p->pack_name);
557 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
558 ret = check_packed_git_idx(idx_name, p);
559 free(idx_name);
560 return ret;
561}
562
11daf39b
SP
563static void scan_windows(struct packed_git *p,
564 struct packed_git **lru_p,
565 struct pack_window **lru_w,
566 struct pack_window **lru_l)
1f688557 567{
11daf39b
SP
568 struct pack_window *w, *w_l;
569
570 for (w_l = NULL, w = p->windows; w; w = w->next) {
571 if (!w->inuse_cnt) {
572 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
573 *lru_p = p;
574 *lru_w = w;
575 *lru_l = w_l;
54044bf8 576 }
54044bf8 577 }
11daf39b 578 w_l = w;
f9253394 579 }
11daf39b
SP
580}
581
d1efefa4 582static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
583{
584 struct packed_git *p, *lru_p = NULL;
585 struct pack_window *lru_w = NULL, *lru_l = NULL;
586
587 if (current)
588 scan_windows(current, &lru_p, &lru_w, &lru_l);
589 for (p = packed_git; p; p = p->next)
590 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
591 if (lru_p) {
592 munmap(lru_w->base, lru_w->len);
593 pack_mapped -= lru_w->len;
594 if (lru_l)
595 lru_l->next = lru_w->next;
596 else {
597 lru_p->windows = lru_w->next;
d1efefa4 598 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
599 close(lru_p->pack_fd);
600 lru_p->pack_fd = -1;
601 }
602 }
603 free(lru_w);
a53128b6 604 pack_open_windows--;
54044bf8
SP
605 return 1;
606 }
607 return 0;
f9253394
JH
608}
609
d1efefa4 610void release_pack_memory(size_t need, int fd)
97bfeb34
SP
611{
612 size_t cur = pack_mapped;
d1efefa4 613 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
614 ; /* nothing */
615}
616
c9ced051
SP
617void close_pack_windows(struct packed_git *p)
618{
619 while (p->windows) {
620 struct pack_window *w = p->windows;
621
622 if (w->inuse_cnt)
623 die("pack '%s' still has open windows to it",
624 p->pack_name);
625 munmap(w->base, w->len);
626 pack_mapped -= w->len;
627 pack_open_windows--;
628 p->windows = w->next;
629 free(w);
630 }
631}
632
03e79c88 633void unuse_pack(struct pack_window **w_cursor)
f9253394 634{
03e79c88
SP
635 struct pack_window *w = *w_cursor;
636 if (w) {
637 w->inuse_cnt--;
638 *w_cursor = NULL;
639 }
1f688557
JH
640}
641
3cf8b462
SP
642/*
643 * Do not call this directly as this leaks p->pack_fd on error return;
644 * call open_packed_git() instead.
645 */
646static int open_packed_git_1(struct packed_git *p)
1f688557 647{
9bc879c1
SP
648 struct stat st;
649 struct pack_header hdr;
650 unsigned char sha1[20];
651 unsigned char *idx_sha1;
2c039da8 652 long fd_flag;
9bc879c1 653
d079837e
SP
654 if (!p->index_data && open_pack_index(p))
655 return error("packfile %s index unavailable", p->pack_name);
656
9bc879c1
SP
657 p->pack_fd = open(p->pack_name, O_RDONLY);
658 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 659 return -1;
9bc879c1
SP
660
661 /* If we created the struct before we had the pack we lack size. */
bf592c50 662 if (!p->pack_size) {
bf592c50 663 if (!S_ISREG(st.st_mode))
072db278 664 return error("packfile %s not a regular file", p->pack_name);
bf592c50 665 p->pack_size = st.st_size;
9bc879c1 666 } else if (p->pack_size != st.st_size)
072db278 667 return error("packfile %s size changed", p->pack_name);
9bc879c1 668
2c039da8
JH
669 /* We leave these file descriptors open with sliding mmap;
670 * there is no point keeping them open across exec(), though.
671 */
672 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
673 if (fd_flag < 0)
072db278 674 return error("cannot determine file descriptor flags");
2c039da8
JH
675 fd_flag |= FD_CLOEXEC;
676 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 677 return error("cannot set FD_CLOEXEC");
2c039da8 678
9bc879c1 679 /* Verify we recognize this pack file format. */
e6e2bd62 680 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 681 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 682 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 683 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 684 if (!pack_version_ok(hdr.hdr_version))
072db278 685 return error("packfile %s is version %u and not supported"
9bc879c1
SP
686 " (try upgrading GIT to a newer version)",
687 p->pack_name, ntohl(hdr.hdr_version));
688
689 /* Verify the pack matches its index. */
57059091 690 if (p->num_objects != ntohl(hdr.hdr_entries))
072db278 691 return error("packfile %s claims to have %u objects"
57059091
NP
692 " while index indicates %u objects",
693 p->pack_name, ntohl(hdr.hdr_entries),
694 p->num_objects);
9bc879c1 695 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 696 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 697 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 698 return error("packfile %s signature is unavailable", p->pack_name);
42873078 699 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 700 if (hashcmp(sha1, idx_sha1))
072db278
SP
701 return error("packfile %s does not match index", p->pack_name);
702 return 0;
9bc879c1
SP
703}
704
3cf8b462
SP
705static int open_packed_git(struct packed_git *p)
706{
707 if (!open_packed_git_1(p))
708 return 0;
709 if (p->pack_fd != -1) {
710 close(p->pack_fd);
711 p->pack_fd = -1;
712 }
713 return -1;
714}
715
c4001d92 716static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
717{
718 /* We must promise at least 20 bytes (one hash) after the
719 * offset is available from this window, otherwise the offset
720 * is not actually in this window and a different window (which
721 * has that one hash excess) must be used. This is to support
722 * the object header and delta base parsing routines below.
723 */
724 off_t win_off = win->offset;
725 return win_off <= offset
726 && (offset + 20) <= (win_off + win->len);
727}
728
03e79c88
SP
729unsigned char* use_pack(struct packed_git *p,
730 struct pack_window **w_cursor,
c4001d92 731 off_t offset,
03e79c88 732 unsigned int *left)
9bc879c1 733{
60bb8b14 734 struct pack_window *win = *w_cursor;
03e79c88 735
072db278
SP
736 if (p->pack_fd == -1 && open_packed_git(p))
737 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
738
739 /* Since packfiles end in a hash of their content and its
740 * pointless to ask for an offset into the middle of that
741 * hash, and the in_window function above wouldn't match
742 * don't allow an offset too close to the end of the file.
743 */
744 if (offset > (p->pack_size - 20))
745 die("offset beyond end of packfile (truncated pack?)");
746
747 if (!win || !in_window(win, offset)) {
748 if (win)
749 win->inuse_cnt--;
750 for (win = p->windows; win; win = win->next) {
751 if (in_window(win, offset))
752 break;
753 }
754 if (!win) {
78a28df9 755 size_t window_align = packed_git_window_size / 2;
dc49cd76 756 off_t len;
60bb8b14 757 win = xcalloc(1, sizeof(*win));
78a28df9 758 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
759 len = p->pack_size - win->offset;
760 if (len > packed_git_window_size)
761 len = packed_git_window_size;
762 win->len = (size_t)len;
60bb8b14 763 pack_mapped += win->len;
11daf39b 764 while (packed_git_limit < pack_mapped
d1efefa4 765 && unuse_one_window(p, p->pack_fd))
60bb8b14 766 ; /* nothing */
c4712e45 767 win->base = xmmap(NULL, win->len,
60bb8b14
SP
768 PROT_READ, MAP_PRIVATE,
769 p->pack_fd, win->offset);
770 if (win->base == MAP_FAILED)
73b4e4be
SP
771 die("packfile %s cannot be mapped: %s",
772 p->pack_name,
773 strerror(errno));
a53128b6
SP
774 pack_mmap_calls++;
775 pack_open_windows++;
776 if (pack_mapped > peak_pack_mapped)
777 peak_pack_mapped = pack_mapped;
778 if (pack_open_windows > peak_pack_open_windows)
779 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
780 win->next = p->windows;
781 p->windows = win;
782 }
1f688557 783 }
03e79c88
SP
784 if (win != *w_cursor) {
785 win->last_used = pack_used_ctr++;
786 win->inuse_cnt++;
787 *w_cursor = win;
788 }
60bb8b14 789 offset -= win->offset;
03e79c88 790 if (left)
dc49cd76 791 *left = win->len - xsize_t(offset);
03e79c88 792 return win->base + offset;
1f688557
JH
793}
794
42873078 795struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
796{
797 struct stat st;
42873078 798 struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
1f688557 799
42873078
NP
800 /*
801 * Make sure a corresponding .pack file exists and that
802 * the index looks sane.
803 */
804 path_len -= strlen(".idx");
805 if (path_len < 1)
1f688557 806 return NULL;
42873078
NP
807 memcpy(p->pack_name, path, path_len);
808 strcpy(p->pack_name + path_len, ".pack");
d079837e 809 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 810 free(p);
1f688557
JH
811 return NULL;
812 }
42873078 813
1f688557
JH
814 /* ok, it looks sane as far as we can check without
815 * actually mapping the pack file.
816 */
d079837e
SP
817 p->index_version = 0;
818 p->index_data = NULL;
819 p->index_size = 0;
820 p->num_objects = 0;
8eca0b47
NP
821 p->num_bad_objects = 0;
822 p->bad_object_sha1 = NULL;
1f688557 823 p->pack_size = st.st_size;
1f688557 824 p->next = NULL;
c41ee586 825 p->windows = NULL;
9bc879c1 826 p->pack_fd = -1;
9d835df2 827 p->pack_local = local;
b867092f 828 p->mtime = st.st_mtime;
42873078
NP
829 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
830 hashclr(p->sha1);
1f688557
JH
831 return p;
832}
833
bf592c50 834struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e 835{
79c6dca4 836 const char *idx_path = sha1_pack_index_name(sha1);
42873078
NP
837 const char *path = sha1_pack_name(sha1);
838 struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
bf592c50 839
42873078
NP
840 if (check_packed_git_idx(idx_path, p)) {
841 free(p);
bf592c50 842 return NULL;
42873078 843 }
bf592c50 844
bf592c50 845 strcpy(p->pack_name, path);
bf592c50 846 p->pack_size = 0;
bf592c50 847 p->next = NULL;
c41ee586 848 p->windows = NULL;
9bc879c1 849 p->pack_fd = -1;
e702496e 850 hashcpy(p->sha1, sha1);
bf592c50
DB
851 return p;
852}
853
854void install_packed_git(struct packed_git *pack)
855{
856 pack->next = packed_git;
857 packed_git = pack;
858}
859
9d835df2 860static void prepare_packed_git_one(char *objdir, int local)
1f688557 861{
9cb18f56
JM
862 /* Ensure that this buffer is large enough so that we can
863 append "/pack/" without clobbering the stack even if
864 strlen(objdir) were PATH_MAX. */
865 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
866 int len;
867 DIR *dir;
868 struct dirent *de;
869
870 sprintf(path, "%s/pack", objdir);
871 len = strlen(path);
872 dir = opendir(path);
b5b16990 873 if (!dir) {
26125f6b 874 if (errno != ENOENT)
bd2afde8 875 error("unable to open object pack directory: %s: %s",
26125f6b 876 path, strerror(errno));
1f688557 877 return;
b5b16990 878 }
1f688557
JH
879 path[len++] = '/';
880 while ((de = readdir(dir)) != NULL) {
881 int namelen = strlen(de->d_name);
882 struct packed_git *p;
883
5bb1cda5 884 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
885 continue;
886
9cb18f56
JM
887 if (len + namelen + 1 > sizeof(path))
888 continue;
889
54a15a8d 890 /* Don't reopen a pack we already have. */
1f688557 891 strcpy(path + len, de->d_name);
86f7780c
JK
892 for (p = packed_git; p; p = p->next) {
893 if (!memcmp(path, p->pack_name, len + namelen - 4))
894 break;
895 }
896 if (p)
897 continue;
54a15a8d
SP
898 /* See if it really is a valid .idx file with corresponding
899 * .pack file that we can map.
900 */
9d835df2 901 p = add_packed_git(path, len + namelen, local);
1f688557
JH
902 if (!p)
903 continue;
625e9421 904 install_packed_git(p);
1f688557 905 }
5b35bcd5 906 closedir(dir);
1f688557
JH
907}
908
b867092f
JH
909static int sort_pack(const void *a_, const void *b_)
910{
911 struct packed_git *a = *((struct packed_git **)a_);
912 struct packed_git *b = *((struct packed_git **)b_);
913 int st;
914
915 /*
916 * Local packs tend to contain objects specific to our
917 * variant of the project than remote ones. In addition,
918 * remote ones could be on a network mounted filesystem.
919 * Favor local ones for these reasons.
920 */
921 st = a->pack_local - b->pack_local;
922 if (st)
923 return -st;
924
925 /*
926 * Younger packs tend to contain more recent objects,
927 * and more recent objects tend to get accessed more
928 * often.
929 */
930 if (a->mtime < b->mtime)
931 return 1;
932 else if (a->mtime == b->mtime)
933 return 0;
934 return -1;
935}
936
937static void rearrange_packed_git(void)
938{
939 struct packed_git **ary, *p;
940 int i, n;
941
942 for (n = 0, p = packed_git; p; p = p->next)
943 n++;
944 if (n < 2)
945 return;
946
947 /* prepare an array of packed_git for easier sorting */
948 ary = xcalloc(n, sizeof(struct packed_git *));
949 for (n = 0, p = packed_git; p; p = p->next)
950 ary[n++] = p;
951
952 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
953
954 /* link them back again */
955 for (i = 0; i < n - 1; i++)
956 ary[i]->next = ary[i + 1];
957 ary[n - 1]->next = NULL;
958 packed_git = ary[0];
959
960 free(ary);
961}
962
637cdd9d 963static int prepare_packed_git_run_once = 0;
9a217f2a 964void prepare_packed_git(void)
1f688557 965{
d5a63b99 966 struct alternate_object_database *alt;
1f688557 967
637cdd9d 968 if (prepare_packed_git_run_once)
1f688557 969 return;
9d835df2 970 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 971 prepare_alt_odb();
d5a63b99 972 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 973 alt->name[-1] = 0;
9d835df2 974 prepare_packed_git_one(alt->base, 0);
1494e038 975 alt->name[-1] = '/';
1f688557 976 }
b867092f 977 rearrange_packed_git();
637cdd9d
JK
978 prepare_packed_git_run_once = 1;
979}
980
fc04c412 981void reprepare_packed_git(void)
637cdd9d
JK
982{
983 prepare_packed_git_run_once = 0;
984 prepare_packed_git();
1f688557
JH
985}
986
8eca0b47
NP
987static void mark_bad_packed_object(struct packed_git *p,
988 const unsigned char *sha1)
989{
990 unsigned i;
991 for (i = 0; i < p->num_bad_objects; i++)
992 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
993 return;
994 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
995 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
996 p->num_bad_objects++;
997}
998
5d6ccf5c 999int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
1000{
1001 unsigned char real_sha1[20];
7cfb5f36 1002 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 1003 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1004}
1005
44d1c19e
LT
1006static int git_open_noatime(const char *name)
1007{
1008 static int sha1_file_open_flag = O_NOATIME;
1009 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1010
1011 /* Might the failure be due to O_NOATIME? */
1012 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1013 fd = open(name, O_RDONLY);
1014 if (fd >= 0)
1015 sha1_file_open_flag = 0;
1016 }
1017 return fd;
1018}
1019
1020static int open_sha1_file(const unsigned char *sha1)
1021{
1022 int fd;
1023 char *name = sha1_file_name(sha1);
1024 struct alternate_object_database *alt;
1025
1026 fd = git_open_noatime(name);
1027 if (fd >= 0)
1028 return fd;
1029
1030 prepare_alt_odb();
1031 errno = ENOENT;
1032 for (alt = alt_odb_list; alt; alt = alt->next) {
1033 name = alt->name;
1034 fill_sha1_path(name, sha1);
1035 fd = git_open_noatime(alt->base);
1036 if (fd >= 0)
1037 return fd;
1038 }
1039 return -1;
1040}
1041
4175e9e3 1042static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1043{
0fcfd160 1044 void *map;
144bde78 1045 int fd;
ace1534d 1046
44d1c19e
LT
1047 fd = open_sha1_file(sha1);
1048 map = NULL;
1049 if (fd >= 0) {
1050 struct stat st;
0fcfd160 1051
44d1c19e
LT
1052 if (!fstat(fd, &st)) {
1053 *size = xsize_t(st.st_size);
1054 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1055 }
44d1c19e 1056 close(fd);
0fcfd160 1057 }
0fcfd160
LT
1058 return map;
1059}
1060
726f852b 1061static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1062{
1063 unsigned int word;
1064
1065 /*
1066 * Is it a zlib-compressed buffer? If so, the first byte
1067 * must be 0x78 (15-bit window size, deflated), and the
1068 * first 16-bit word is evenly divisible by 31
1069 */
1070 word = (map[0] << 8) + map[1];
1071 if (map[0] == 0x78 && !(word % 31))
1072 return 1;
1073 else
1074 return 0;
1075}
1076
72518e9c 1077unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1078{
ad1ed5ee 1079 unsigned shift;
93821bd9 1080 unsigned char c;
93821bd9 1081 unsigned long size;
ad1ed5ee
JH
1082 unsigned long used = 0;
1083
1084 c = buf[used++];
1085 *type = (c >> 4) & 7;
1086 size = c & 15;
1087 shift = 4;
1088 while (c & 0x80) {
1089 if (len <= used)
1090 return 0;
1091 if (sizeof(long) * 8 <= shift)
1092 return 0;
1093 c = buf[used++];
1094 size += (c & 0x7f) << shift;
1095 shift += 7;
1096 }
1097 *sizep = size;
1098 return used;
1099}
1100
1101static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1102{
1103 unsigned long size, used;
1104 static const char valid_loose_object_type[8] = {
1105 0, /* OBJ_EXT */
1106 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1107 0, /* "delta" and others are invalid in a loose object */
93821bd9 1108 };
ad1ed5ee 1109 enum object_type type;
93821bd9 1110
c4483576
LT
1111 /* Get the data stream */
1112 memset(stream, 0, sizeof(*stream));
1113 stream->next_in = map;
1114 stream->avail_in = mapsize;
1115 stream->next_out = buffer;
93821bd9
LT
1116 stream->avail_out = bufsiz;
1117
bb6b8e4f 1118 if (legacy_loose_object(map)) {
93821bd9
LT
1119 inflateInit(stream);
1120 return inflate(stream, 0);
1121 }
1122
726f852b
NP
1123
1124 /*
1125 * There used to be a second loose object header format which
1126 * was meant to mimic the in-pack format, allowing for direct
1127 * copy of the object data. This format turned up not to be
1128 * really worth it and we don't write it any longer. But we
1129 * can still read it.
1130 */
ad1ed5ee
JH
1131 used = unpack_object_header_gently(map, mapsize, &type, &size);
1132 if (!used || !valid_loose_object_type[type])
93821bd9 1133 return -1;
ad1ed5ee
JH
1134 map += used;
1135 mapsize -= used;
93821bd9
LT
1136
1137 /* Set up the stream for the rest.. */
1138 stream->next_in = map;
1139 stream->avail_in = mapsize;
c4483576 1140 inflateInit(stream);
93821bd9
LT
1141
1142 /* And generate the fake traditional header */
ad1ed5ee 1143 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1144 typename(type), size);
93821bd9 1145 return 0;
c4483576
LT
1146}
1147
7efbff75 1148static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1149{
1150 int bytes = strlen(buffer) + 1;
d565b341 1151 unsigned char *buf = xmalloc(1+size);
93821bd9 1152 unsigned long n;
7efbff75 1153 int status = Z_OK;
5180cacc 1154
93821bd9
LT
1155 n = stream->total_out - bytes;
1156 if (n > size)
1157 n = size;
1158 memcpy(buf, (char *) buffer + bytes, n);
1159 bytes = n;
456cdf6e
LT
1160 if (bytes <= size) {
1161 /*
1162 * The above condition must be (bytes <= size), not
1163 * (bytes < size). In other words, even though we
1164 * expect no more output and set avail_out to zer0,
1165 * the input zlib stream may have bytes that express
1166 * "this concludes the stream", and we *do* want to
1167 * eat that input.
1168 *
1169 * Otherwise we would not be able to test that we
1170 * consumed all the input to reach the expected size;
1171 * we also want to check that zlib tells us that all
1172 * went well with status == Z_STREAM_END at the end.
1173 */
5180cacc
LT
1174 stream->next_out = buf + bytes;
1175 stream->avail_out = size - bytes;
7efbff75
JH
1176 while (status == Z_OK)
1177 status = inflate(stream, Z_FINISH);
5180cacc
LT
1178 }
1179 buf[size] = 0;
456cdf6e 1180 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1181 inflateEnd(stream);
1182 return buf;
1183 }
1184
1185 if (status < 0)
1186 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1187 else if (stream->avail_in)
1188 error("garbage at end of loose object '%s'",
1189 sha1_to_hex(sha1));
1190 free(buf);
1191 return NULL;
5180cacc
LT
1192}
1193
1194/*
1195 * We used to just use "sscanf()", but that's actually way
1196 * too permissive for what we want to check. So do an anal
1197 * object header parse by hand.
1198 */
21666f1a 1199static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1200{
21666f1a 1201 char type[10];
5180cacc
LT
1202 int i;
1203 unsigned long size;
1204
1205 /*
a6080a0a 1206 * The type can be at most ten bytes (including the
5180cacc 1207 * terminating '\0' that we add), and is followed by
21666f1a 1208 * a space.
5180cacc 1209 */
21666f1a 1210 i = 0;
5180cacc
LT
1211 for (;;) {
1212 char c = *hdr++;
1213 if (c == ' ')
1214 break;
21666f1a
NP
1215 type[i++] = c;
1216 if (i >= sizeof(type))
5180cacc 1217 return -1;
5180cacc 1218 }
21666f1a 1219 type[i] = 0;
5180cacc
LT
1220
1221 /*
1222 * The length must follow immediately, and be in canonical
1223 * decimal format (ie "010" is not valid).
1224 */
1225 size = *hdr++ - '0';
1226 if (size > 9)
1227 return -1;
1228 if (size) {
1229 for (;;) {
1230 unsigned long c = *hdr - '0';
1231 if (c > 9)
1232 break;
1233 hdr++;
1234 size = size * 10 + c;
1235 }
1236 }
1237 *sizep = size;
1238
1239 /*
1240 * The length must be followed by a zero byte
1241 */
21666f1a 1242 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1243}
1244
7efbff75 1245static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1246{
5180cacc 1247 int ret;
0fcfd160 1248 z_stream stream;
5180cacc 1249 char hdr[8192];
0fcfd160 1250
5180cacc 1251 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1252 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1253 return NULL;
1254
7efbff75 1255 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1256}
1257
54dab52a
NP
1258unsigned long get_size_from_delta(struct packed_git *p,
1259 struct pack_window **w_curs,
1260 off_t curpos)
1261{
1262 const unsigned char *data;
1263 unsigned char delta_head[20], *in;
1264 z_stream stream;
1265 int st;
1266
1267 memset(&stream, 0, sizeof(stream));
1268 stream.next_out = delta_head;
1269 stream.avail_out = sizeof(delta_head);
1270
1271 inflateInit(&stream);
1272 do {
1273 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1274 stream.next_in = in;
1275 st = inflate(&stream, Z_FINISH);
1276 curpos += stream.next_in - in;
1277 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1278 stream.total_out < sizeof(delta_head));
1279 inflateEnd(&stream);
1280 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1281 die("delta data unpack-initial failed");
1282
1283 /* Examine the initial part of the delta to figure out
1284 * the result size.
1285 */
1286 data = delta_head;
1287
1288 /* ignore base size */
1289 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1290
1291 /* Read the result size */
1292 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1293}
1294
c4001d92 1295static off_t get_delta_base(struct packed_git *p,
03e79c88 1296 struct pack_window **w_curs,
c4001d92 1297 off_t *curpos,
21666f1a 1298 enum object_type type,
c4001d92 1299 off_t delta_obj_offset)
eb32d236 1300{
2b87c45b 1301 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1302 off_t base_offset;
eb32d236 1303
8d8a4ea5
SP
1304 /* use_pack() assured us we have [base_info, base_info + 20)
1305 * as a range that we can look at without walking off the
1306 * end of the mapped window. Its actually the hash size
1307 * that is assured. An OFS_DELTA longer than the hash size
1308 * is stupid, as then a REF_DELTA would be smaller to store.
1309 */
21666f1a 1310 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1311 unsigned used = 0;
1312 unsigned char c = base_info[used++];
1313 base_offset = c & 127;
1314 while (c & 128) {
1315 base_offset += 1;
8723f216 1316 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1317 return 0; /* overflow */
eb32d236
NP
1318 c = base_info[used++];
1319 base_offset = (base_offset << 7) + (c & 127);
1320 }
1321 base_offset = delta_obj_offset - base_offset;
1322 if (base_offset >= delta_obj_offset)
8eca0b47 1323 return 0; /* out of bound */
2b87c45b 1324 *curpos += used;
21666f1a 1325 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1326 /* The base entry _must_ be in the same pack */
1327 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1328 *curpos += 20;
eb32d236
NP
1329 } else
1330 die("I am totally screwed");
2b87c45b 1331 return base_offset;
eb32d236
NP
1332}
1333
f3bf9224 1334/* forward declaration for a mutually recursive function */
c4001d92 1335static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1336 unsigned long *sizep);
f3bf9224 1337
43057304 1338static int packed_delta_info(struct packed_git *p,
03e79c88 1339 struct pack_window **w_curs,
c4001d92 1340 off_t curpos,
21666f1a 1341 enum object_type type,
c4001d92 1342 off_t obj_offset,
43057304 1343 unsigned long *sizep)
5db47c2b 1344{
c4001d92 1345 off_t base_offset;
f3bf9224 1346
21666f1a
NP
1347 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1348 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1349
c62266f3
JH
1350 /* We choose to only get the type of the base object and
1351 * ignore potentially corrupt pack file that expects the delta
1352 * based on a base with a wrong size. This saves tons of
1353 * inflate() calls.
1354 */
54dab52a
NP
1355 if (sizep)
1356 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1357
1358 return type;
5db47c2b
JH
1359}
1360
2b87c45b
NP
1361static int unpack_object_header(struct packed_git *p,
1362 struct pack_window **w_curs,
c4001d92 1363 off_t *curpos,
2b87c45b 1364 unsigned long *sizep)
a733cb60 1365{
03e79c88
SP
1366 unsigned char *base;
1367 unsigned int left;
ad1ed5ee 1368 unsigned long used;
2b87c45b 1369 enum object_type type;
a733cb60 1370
8d8a4ea5
SP
1371 /* use_pack() assures us we have [base, base + 20) available
1372 * as a range that we can look at at. (Its actually the hash
3dff5379 1373 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1374 * the maximum deflated object size is 2^137, which is just
1375 * insane, so we know won't exceed what we have been given.
1376 */
2b87c45b
NP
1377 base = use_pack(p, w_curs, *curpos, &left);
1378 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1379 if (!used)
1380 die("object offset outside of pack file");
2b87c45b 1381 *curpos += used;
ad1ed5ee 1382
2b87c45b 1383 return type;
a733cb60
LT
1384}
1385
21666f1a 1386const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1387 off_t obj_offset,
21666f1a
NP
1388 unsigned long *size,
1389 unsigned long *store_size,
1390 unsigned int *delta_chain_length,
1391 unsigned char *base_sha1)
ad8c80a5 1392{
03e79c88 1393 struct pack_window *w_curs = NULL;
c4001d92
SP
1394 off_t curpos;
1395 unsigned long dummy;
43057304 1396 unsigned char *next_sha1;
21666f1a 1397 enum object_type type;
70f5d5d3 1398 struct revindex_entry *revidx;
ad8c80a5 1399
43057304 1400 *delta_chain_length = 0;
2b87c45b 1401 curpos = obj_offset;
21666f1a 1402 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304 1403
70f5d5d3
NP
1404 revidx = find_pack_revindex(p, obj_offset);
1405 *store_size = revidx[1].offset - obj_offset;
1406
43057304 1407 for (;;) {
21666f1a 1408 switch (type) {
43057304 1409 default:
08a19d87 1410 die("pack %s contains unknown object type %d",
21666f1a 1411 p->pack_name, type);
43057304
NP
1412 case OBJ_COMMIT:
1413 case OBJ_TREE:
1414 case OBJ_BLOB:
1415 case OBJ_TAG:
03e79c88 1416 unuse_pack(&w_curs);
21666f1a 1417 return typename(type);
eb32d236 1418 case OBJ_OFS_DELTA:
21666f1a 1419 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
8eca0b47
NP
1420 if (!obj_offset)
1421 die("pack %s contains bad delta base reference of type %s",
1422 p->pack_name, typename(type));
eb32d236 1423 if (*delta_chain_length == 0) {
70f5d5d3
NP
1424 revidx = find_pack_revindex(p, obj_offset);
1425 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
eb32d236
NP
1426 }
1427 break;
1428 case OBJ_REF_DELTA:
2b87c45b 1429 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1430 if (*delta_chain_length == 0)
1431 hashcpy(base_sha1, next_sha1);
2b87c45b 1432 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1433 break;
1434 }
43057304 1435 (*delta_chain_length)++;
2b87c45b 1436 curpos = obj_offset;
21666f1a 1437 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1438 }
ad8c80a5
JH
1439}
1440
c4001d92 1441static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1442 unsigned long *sizep)
1f688557 1443{
03e79c88 1444 struct pack_window *w_curs = NULL;
c4001d92
SP
1445 unsigned long size;
1446 off_t curpos = obj_offset;
21666f1a 1447 enum object_type type;
5db47c2b 1448
21666f1a 1449 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1450
21666f1a 1451 switch (type) {
eb32d236
NP
1452 case OBJ_OFS_DELTA:
1453 case OBJ_REF_DELTA:
21666f1a
NP
1454 type = packed_delta_info(p, &w_curs, curpos,
1455 type, obj_offset, sizep);
2b87c45b 1456 break;
a733cb60 1457 case OBJ_COMMIT:
a733cb60 1458 case OBJ_TREE:
a733cb60 1459 case OBJ_BLOB:
a733cb60 1460 case OBJ_TAG:
2b87c45b
NP
1461 if (sizep)
1462 *sizep = size;
a69d0943 1463 break;
1f688557 1464 default:
08a19d87 1465 die("pack %s contains unknown object type %d",
21666f1a 1466 p->pack_name, type);
1f688557 1467 }
2b87c45b 1468 unuse_pack(&w_curs);
21666f1a 1469 return type;
1f688557
JH
1470}
1471
eb950c19 1472static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1473 struct pack_window **w_curs,
c4001d92 1474 off_t curpos,
eb950c19 1475 unsigned long size)
de530aaa
SP
1476{
1477 int st;
1478 z_stream stream;
079afb18 1479 unsigned char *buffer, *in;
de530aaa
SP
1480
1481 buffer = xmalloc(size + 1);
1482 buffer[size] = 0;
1483 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1484 stream.next_out = buffer;
1485 stream.avail_out = size;
1486
1487 inflateInit(&stream);
079afb18 1488 do {
2b87c45b 1489 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1490 stream.next_in = in;
1491 st = inflate(&stream, Z_FINISH);
2b87c45b 1492 curpos += stream.next_in - in;
079afb18 1493 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1494 inflateEnd(&stream);
1495 if ((st != Z_STREAM_END) || stream.total_out != size) {
1496 free(buffer);
1497 return NULL;
1498 }
1499
1500 return buffer;
1501}
1502
e5e01619
LT
1503#define MAX_DELTA_CACHE (256)
1504
18bdec11 1505static size_t delta_base_cached;
5e08ecbf
NP
1506
1507static struct delta_base_cache_lru_list {
1508 struct delta_base_cache_lru_list *prev;
1509 struct delta_base_cache_lru_list *next;
1510} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1511
e5e01619 1512static struct delta_base_cache_entry {
5e08ecbf
NP
1513 struct delta_base_cache_lru_list lru;
1514 void *data;
e5e01619
LT
1515 struct packed_git *p;
1516 off_t base_offset;
1517 unsigned long size;
e5e01619
LT
1518 enum object_type type;
1519} delta_base_cache[MAX_DELTA_CACHE];
1520
1521static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1522{
1523 unsigned long hash;
1524
1525 hash = (unsigned long)p + (unsigned long)base_offset;
1526 hash += (hash >> 8) + (hash >> 16);
3358004a 1527 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1528}
1529
62f255ad 1530static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1531 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1532{
e5e01619
LT
1533 void *ret;
1534 unsigned long hash = pack_entry_hash(p, base_offset);
1535 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1536
1537 ret = ent->data;
1538 if (ret && ent->p == p && ent->base_offset == base_offset)
1539 goto found_cache_entry;
62f255ad 1540 return unpack_entry(p, base_offset, type, base_size);
e5e01619
LT
1541
1542found_cache_entry:
18bdec11 1543 if (!keep_cache) {
a0cba108 1544 ent->data = NULL;
5e08ecbf
NP
1545 ent->lru.next->prev = ent->lru.prev;
1546 ent->lru.prev->next = ent->lru.next;
18bdec11 1547 delta_base_cached -= ent->size;
182af834
PH
1548 } else {
1549 ret = xmemdupz(ent->data, ent->size);
a0cba108 1550 }
e5e01619
LT
1551 *type = ent->type;
1552 *base_size = ent->size;
1553 return ret;
62f255ad
LT
1554}
1555
18bdec11
SP
1556static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1557{
1558 if (ent->data) {
1559 free(ent->data);
1560 ent->data = NULL;
5e08ecbf
NP
1561 ent->lru.next->prev = ent->lru.prev;
1562 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1563 delta_base_cached -= ent->size;
1564 }
1565}
1566
62f255ad
LT
1567static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1568 void *base, unsigned long base_size, enum object_type type)
1569{
5e08ecbf 1570 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1571 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1572 struct delta_base_cache_lru_list *lru;
e5e01619 1573
18bdec11
SP
1574 release_delta_base_cache(ent);
1575 delta_base_cached += base_size;
5e08ecbf
NP
1576
1577 for (lru = delta_base_cache_lru.next;
1578 delta_base_cached > delta_base_cache_limit
1579 && lru != &delta_base_cache_lru;
1580 lru = lru->next) {
1581 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1582 if (f->type == OBJ_BLOB)
1583 release_delta_base_cache(f);
1584 }
5e08ecbf
NP
1585 for (lru = delta_base_cache_lru.next;
1586 delta_base_cached > delta_base_cache_limit
1587 && lru != &delta_base_cache_lru;
1588 lru = lru->next) {
1589 struct delta_base_cache_entry *f = (void *)lru;
1590 release_delta_base_cache(f);
1591 }
18bdec11 1592
e5e01619
LT
1593 ent->p = p;
1594 ent->base_offset = base_offset;
1595 ent->type = type;
1596 ent->data = base;
1597 ent->size = base_size;
5e08ecbf
NP
1598 ent->lru.next = &delta_base_cache_lru;
1599 ent->lru.prev = delta_base_cache_lru.prev;
1600 delta_base_cache_lru.prev->next = &ent->lru;
1601 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1602}
1603
eb950c19 1604static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1605 struct pack_window **w_curs,
c4001d92 1606 off_t curpos,
1f688557 1607 unsigned long delta_size,
c4001d92 1608 off_t obj_offset,
21666f1a 1609 enum object_type *type,
eb950c19 1610 unsigned long *sizep)
1f688557 1611{
7c3e8be3 1612 void *delta_data, *result, *base;
c4001d92
SP
1613 unsigned long base_size;
1614 off_t base_offset;
43057304 1615
21666f1a 1616 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
8eca0b47
NP
1617 if (!base_offset) {
1618 error("failed to validate delta base reference "
1619 "at offset %"PRIuMAX" from %s",
1620 (uintmax_t)curpos, p->pack_name);
1621 return NULL;
1622 }
a0cba108 1623 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
8eca0b47
NP
1624 if (!base) {
1625 /*
1626 * We're probably in deep shit, but let's try to fetch
1627 * the required base anyway from another pack or loose.
1628 * This is costly but should happen only in the presence
1629 * of a corrupted pack, and is better than failing outright.
1630 */
1631 struct revindex_entry *revidx = find_pack_revindex(p, base_offset);
1632 const unsigned char *base_sha1 =
1633 nth_packed_object_sha1(p, revidx->nr);
1634 error("failed to read delta base object %s"
1635 " at offset %"PRIuMAX" from %s",
1636 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1637 p->pack_name);
1638 mark_bad_packed_object(p, base_sha1);
1639 base = read_sha1_file(base_sha1, type, &base_size);
1640 if (!base)
1641 return NULL;
1642 }
67686d95 1643
2b87c45b 1644 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
8eca0b47
NP
1645 if (!delta_data) {
1646 error("failed to unpack compressed delta "
1647 "at offset %"PRIuMAX" from %s",
1648 (uintmax_t)curpos, p->pack_name);
1649 free(base);
1650 return NULL;
1651 }
1f688557
JH
1652 result = patch_delta(base, base_size,
1653 delta_data, delta_size,
21666f1a 1654 sizep);
1f688557
JH
1655 if (!result)
1656 die("failed to apply delta");
1657 free(delta_data);
62f255ad 1658 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1659 return result;
1660}
1661
c4001d92 1662void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1663 enum object_type *type, unsigned long *sizep)
1f688557 1664{
03e79c88 1665 struct pack_window *w_curs = NULL;
c4001d92 1666 off_t curpos = obj_offset;
21666f1a 1667 void *data;
1f688557 1668
21666f1a
NP
1669 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1670 switch (*type) {
eb32d236
NP
1671 case OBJ_OFS_DELTA:
1672 case OBJ_REF_DELTA:
21666f1a
NP
1673 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1674 obj_offset, type, sizep);
4d703a1a 1675 break;
a733cb60 1676 case OBJ_COMMIT:
a733cb60 1677 case OBJ_TREE:
a733cb60 1678 case OBJ_BLOB:
a733cb60 1679 case OBJ_TAG:
21666f1a 1680 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1681 break;
1f688557 1682 default:
8eca0b47
NP
1683 data = NULL;
1684 error("unknown object type %i at offset %"PRIuMAX" in %s",
1685 *type, (uintmax_t)obj_offset, p->pack_name);
1f688557 1686 }
03e79c88 1687 unuse_pack(&w_curs);
21666f1a 1688 return data;
1f688557
JH
1689}
1690
d079837e 1691const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1692 uint32_t n)
9a217f2a 1693{
42873078 1694 const unsigned char *index = p->index_data;
d079837e
SP
1695 if (!index) {
1696 if (open_pack_index(p))
1697 return NULL;
1698 index = p->index_data;
1699 }
57059091 1700 if (n >= p->num_objects)
d72308e0 1701 return NULL;
74e34e1f
NP
1702 index += 4 * 256;
1703 if (p->index_version == 1) {
1704 return index + 24 * n + 4;
1705 } else {
1706 index += 8;
1707 return index + 20 * n;
1708 }
1709}
1710
1711static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1712{
1713 const unsigned char *index = p->index_data;
1714 index += 4 * 256;
1715 if (p->index_version == 1) {
1716 return ntohl(*((uint32_t *)(index + 24 * n)));
1717 } else {
1718 uint32_t off;
1719 index += 8 + p->num_objects * (20 + 4);
1720 off = ntohl(*((uint32_t *)(index + 4 * n)));
1721 if (!(off & 0x80000000))
1722 return off;
1723 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1724 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1725 ntohl(*((uint32_t *)(index + 4)));
1726 }
9a217f2a
JH
1727}
1728
c4001d92 1729off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1730 struct packed_git *p)
1f688557 1731{
42873078 1732 const uint32_t *level1_ofs = p->index_data;
42873078 1733 const unsigned char *index = p->index_data;
628522ec
JH
1734 unsigned hi, lo, stride;
1735 static int use_lookup = -1;
1736 static int debug_lookup = -1;
1737
1738 if (debug_lookup < 0)
1739 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1740
d079837e
SP
1741 if (!index) {
1742 if (open_pack_index(p))
1743 return 0;
1744 level1_ofs = p->index_data;
1745 index = p->index_data;
1746 }
74e34e1f
NP
1747 if (p->index_version > 1) {
1748 level1_ofs += 2;
1749 index += 8;
1750 }
42873078 1751 index += 4 * 256;
74e34e1f
NP
1752 hi = ntohl(level1_ofs[*sha1]);
1753 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
1754 if (p->index_version > 1) {
1755 stride = 20;
1756 } else {
1757 stride = 24;
1758 index += 4;
1759 }
1760
1761 if (debug_lookup)
1762 printf("%02x%02x%02x... lo %u hi %u nr %u\n",
1763 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1764
1765 if (use_lookup < 0)
1766 use_lookup = !!getenv("GIT_USE_LOOKUP");
1767 if (use_lookup) {
1768 int pos = sha1_entry_pos(index, stride, 0,
1769 lo, hi, p->num_objects, sha1);
1770 if (pos < 0)
1771 return 0;
1772 return nth_packed_object_offset(p, pos);
1773 }
1f688557
JH
1774
1775 do {
74e34e1f 1776 unsigned mi = (lo + hi) / 2;
628522ec
JH
1777 int cmp = hashcmp(index + mi * stride, sha1);
1778
1779 if (debug_lookup)
1780 printf("lo %u hi %u rg %u mi %u\n",
1781 lo, hi, hi - lo, mi);
43057304 1782 if (!cmp)
74e34e1f 1783 return nth_packed_object_offset(p, mi);
1f688557
JH
1784 if (cmp > 0)
1785 hi = mi;
1786 else
1787 lo = mi+1;
1788 } while (lo < hi);
1789 return 0;
1790}
1791
000dfd3f 1792int matches_pack_name(struct packed_git *p, const char *name)
d4ff6d92
SP
1793{
1794 const char *last_c, *c;
1795
000dfd3f
JH
1796 if (!strcmp(p->pack_name, name))
1797 return 1;
d4ff6d92
SP
1798
1799 for (c = p->pack_name, last_c = c; *c;)
1800 if (*c == '/')
1801 last_c = ++c;
1802 else
1803 ++c;
000dfd3f
JH
1804 if (!strcmp(last_c, name))
1805 return 1;
d4ff6d92 1806
000dfd3f 1807 return 0;
d4ff6d92
SP
1808}
1809
106d710b 1810static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1811{
f7c22cc6 1812 static struct packed_git *last_found = (void *)1;
1f688557 1813 struct packed_git *p;
c4001d92 1814 off_t offset;
43057304 1815
1f688557 1816 prepare_packed_git();
f7c22cc6
NP
1817 if (!packed_git)
1818 return 0;
1819 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1820
f7c22cc6 1821 do {
106d710b
JH
1822 if (ignore_packed) {
1823 const char **ig;
1824 for (ig = ignore_packed; *ig; ig++)
000dfd3f 1825 if (matches_pack_name(p, *ig))
106d710b
JH
1826 break;
1827 if (*ig)
f7c22cc6 1828 goto next;
106d710b 1829 }
f7c22cc6 1830
8eca0b47
NP
1831 if (p->num_bad_objects) {
1832 unsigned i;
1833 for (i = 0; i < p->num_bad_objects; i++)
1834 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1835 goto next;
1836 }
1837
43057304
NP
1838 offset = find_pack_entry_one(sha1, p);
1839 if (offset) {
c715f783
SP
1840 /*
1841 * We are about to tell the caller where they can
1842 * locate the requested object. We better make
1843 * sure the packfile is still here and can be
1844 * accessed before supplying that answer, as
1845 * it may have been deleted since the index
1846 * was loaded!
1847 */
1848 if (p->pack_fd == -1 && open_packed_git(p)) {
1849 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1850 goto next;
c715f783 1851 }
43057304
NP
1852 e->offset = offset;
1853 e->p = p;
1854 hashcpy(e->sha1, sha1);
f7c22cc6 1855 last_found = p;
1f688557 1856 return 1;
43057304 1857 }
f7c22cc6
NP
1858
1859 next:
1860 if (p == last_found)
1861 p = packed_git;
1862 else
1863 p = p->next;
1864 if (p == last_found)
1865 p = p->next;
1866 } while (p);
1f688557
JH
1867 return 0;
1868}
1869
a6080a0a 1870struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1871 struct packed_git *packs)
1872{
1873 struct packed_git *p;
bf592c50
DB
1874
1875 for (p = packs; p; p = p->next) {
43057304 1876 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1877 return p;
1878 }
1879 return NULL;
21666f1a 1880
bf592c50
DB
1881}
1882
21666f1a 1883static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1884{
36e4d74a 1885 int status;
65c2e0c3
JH
1886 unsigned long mapsize, size;
1887 void *map;
1888 z_stream stream;
d65a16f6 1889 char hdr[32];
65c2e0c3 1890
bb6b8e4f 1891 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1892 if (!map)
1893 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1894 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1895 status = error("unable to unpack %s header",
1896 sha1_to_hex(sha1));
21666f1a 1897 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1898 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1899 else if (sizep)
1900 *sizep = size;
65c2e0c3
JH
1901 inflateEnd(&stream);
1902 munmap(map, mapsize);
1903 return status;
1904}
1905
21666f1a 1906int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1907{
f0df4ed5
JS
1908 struct pack_entry e;
1909
1910 if (!find_pack_entry(sha1, &e, NULL)) {
1911 reprepare_packed_git();
1912 if (!find_pack_entry(sha1, &e, NULL))
21666f1a 1913 return sha1_loose_object_info(sha1, sizep);
f0df4ed5 1914 }
21666f1a 1915 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1916}
1917
21666f1a
NP
1918static void *read_packed_sha1(const unsigned char *sha1,
1919 enum object_type *type, unsigned long *size)
1f688557
JH
1920{
1921 struct pack_entry e;
8eca0b47 1922 void *data;
1f688557 1923
8276c007 1924 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1925 return NULL;
8eca0b47
NP
1926 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1927 if (!data) {
1928 /*
1929 * We're probably in deep shit, but let's try to fetch
1930 * the required object anyway from another pack or loose.
1931 * This should happen only in the presence of a corrupted
1932 * pack, and is better than failing outright.
1933 */
1934 error("failed to read object %s at offset %"PRIuMAX" from %s",
1935 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1936 mark_bad_packed_object(e.p, sha1);
1937 data = read_sha1_file(sha1, type, size);
1938 }
1939 return data;
1f688557
JH
1940}
1941
d66b37bb
JH
1942/*
1943 * This is meant to hold a *small* number of objects that you would
1944 * want read_sha1_file() to be able to return, but yet you do not want
1945 * to write them into the object store (e.g. a browse-only
1946 * application).
1947 */
1948static struct cached_object {
1949 unsigned char sha1[20];
21666f1a 1950 enum object_type type;
d66b37bb
JH
1951 void *buf;
1952 unsigned long size;
1953} *cached_objects;
1954static int cached_object_nr, cached_object_alloc;
1955
346245a1
JK
1956static struct cached_object empty_tree = {
1957 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
1958 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
1959 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
1960 OBJ_TREE,
1961 "",
1962 0
1963};
1964
d66b37bb
JH
1965static struct cached_object *find_cached_object(const unsigned char *sha1)
1966{
1967 int i;
1968 struct cached_object *co = cached_objects;
1969
1970 for (i = 0; i < cached_object_nr; i++, co++) {
1971 if (!hashcmp(co->sha1, sha1))
1972 return co;
1973 }
346245a1
JK
1974 if (!hashcmp(sha1, empty_tree.sha1))
1975 return &empty_tree;
d66b37bb
JH
1976 return NULL;
1977}
1978
21666f1a
NP
1979int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1980 unsigned char *sha1)
d66b37bb
JH
1981{
1982 struct cached_object *co;
1983
21666f1a 1984 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
1985 if (has_sha1_file(sha1) || find_cached_object(sha1))
1986 return 0;
1987 if (cached_object_alloc <= cached_object_nr) {
1988 cached_object_alloc = alloc_nr(cached_object_alloc);
1989 cached_objects = xrealloc(cached_objects,
1990 sizeof(*cached_objects) *
1991 cached_object_alloc);
1992 }
1993 co = &cached_objects[cached_object_nr++];
1994 co->size = len;
21666f1a 1995 co->type = type;
efa13f7b
JH
1996 co->buf = xmalloc(len);
1997 memcpy(co->buf, buf, len);
d66b37bb
JH
1998 hashcpy(co->sha1, sha1);
1999 return 0;
2000}
2001
21666f1a
NP
2002void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
2003 unsigned long *size)
0fcfd160
LT
2004{
2005 unsigned long mapsize;
2006 void *map, *buf;
d66b37bb
JH
2007 struct cached_object *co;
2008
2009 co = find_cached_object(sha1);
2010 if (co) {
21666f1a 2011 *type = co->type;
d66b37bb 2012 *size = co->size;
182af834 2013 return xmemdupz(co->buf, co->size);
d66b37bb 2014 }
0fcfd160 2015
8276c007
PE
2016 buf = read_packed_sha1(sha1, type, size);
2017 if (buf)
2018 return buf;
bb6b8e4f 2019 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2020 if (map) {
7efbff75 2021 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2022 munmap(map, mapsize);
2023 return buf;
2024 }
637cdd9d 2025 reprepare_packed_git();
8276c007 2026 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2027}
2028
40469ee9 2029void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2030 const char *required_type_name,
40469ee9
JH
2031 unsigned long *size,
2032 unsigned char *actual_sha1_return)
f4913f91 2033{
21666f1a 2034 enum object_type type, required_type;
f4913f91
JH
2035 void *buffer;
2036 unsigned long isize;
40469ee9 2037 unsigned char actual_sha1[20];
f4913f91 2038
21666f1a 2039 required_type = type_from_string(required_type_name);
e702496e 2040 hashcpy(actual_sha1, sha1);
40469ee9
JH
2041 while (1) {
2042 int ref_length = -1;
2043 const char *ref_type = NULL;
f4913f91 2044
21666f1a 2045 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2046 if (!buffer)
2047 return NULL;
21666f1a 2048 if (type == required_type) {
40469ee9
JH
2049 *size = isize;
2050 if (actual_sha1_return)
e702496e 2051 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2052 return buffer;
2053 }
2054 /* Handle references */
21666f1a 2055 else if (type == OBJ_COMMIT)
40469ee9 2056 ref_type = "tree ";
21666f1a 2057 else if (type == OBJ_TAG)
40469ee9
JH
2058 ref_type = "object ";
2059 else {
2060 free(buffer);
2061 return NULL;
2062 }
2063 ref_length = strlen(ref_type);
f4913f91 2064
50974ec9
MK
2065 if (ref_length + 40 > isize ||
2066 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2067 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2068 free(buffer);
2069 return NULL;
2070 }
1cf58e72 2071 free(buffer);
40469ee9
JH
2072 /* Now we have the ID of the referred-to object in
2073 * actual_sha1. Check again. */
f4913f91 2074 }
f4913f91
JH
2075}
2076
ce9fbf16 2077static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2078 const char *type, unsigned char *sha1,
d65a16f6 2079 char *hdr, int *hdrlen)
d410c0f5
JH
2080{
2081 SHA_CTX c;
2082
2083 /* Generate the header */
d65a16f6 2084 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2085
2086 /* Sha1.. */
2087 SHA1_Init(&c);
2088 SHA1_Update(&c, hdr, *hdrlen);
2089 SHA1_Update(&c, buf, len);
2090 SHA1_Final(sha1, &c);
d410c0f5
JH
2091}
2092
230f1322
LT
2093/*
2094 * Move the just written object into its final resting place
2095 */
839837b9 2096int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2097{
5723fe7e 2098 int ret = link(tmpfile, filename);
7ebb6fca
LT
2099
2100 /*
2101 * Coda hack - coda doesn't like cross-directory links,
2102 * so we fall back to a rename, which will mean that it
2103 * won't be able to check collisions, but that's not a
2104 * big deal.
2105 *
2106 * The same holds for FAT formatted media.
2107 *
2108 * When this succeeds, we just return 0. We have nothing
2109 * left to unlink.
2110 */
2111 if (ret && ret != EEXIST) {
2112 if (!rename(tmpfile, filename))
230f1322 2113 return 0;
9e48b389 2114 ret = errno;
230f1322
LT
2115 }
2116 unlink(tmpfile);
2117 if (ret) {
2118 if (ret != EEXIST) {
916d081b 2119 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2120 }
2121 /* FIXME!!! Collision check here ? */
2122 }
2123
2124 return 0;
2125}
2126
4d548150
LT
2127static int write_buffer(int fd, const void *buf, size_t len)
2128{
d34cf19b 2129 if (write_in_full(fd, buf, len) < 0)
93822c22 2130 return error("file write error (%s)", strerror(errno));
4d548150
LT
2131 return 0;
2132}
2133
ce9fbf16 2134int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2135 unsigned char *sha1)
2136{
d65a16f6 2137 char hdr[32];
abdc3fc8
RS
2138 int hdrlen;
2139 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2140 return 0;
2141}
2142
e9039dd3
LT
2143/* Finalize a file on disk, and close it. */
2144static void close_sha1_file(int fd)
2145{
2146 /* For safe-mode, we could fsync_or_die(fd, "sha1 file") here */
2147 fchmod(fd, 0444);
2148 if (close(fd) != 0)
2149 die("unable to write sha1 file");
2150}
2151
5723fe7e
LT
2152/* Size of directory component, including the ending '/' */
2153static inline int directory_size(const char *filename)
2154{
2155 const char *s = strrchr(filename, '/');
2156 if (!s)
2157 return 0;
2158 return s - filename + 1;
2159}
2160
2161/*
2162 * This creates a temporary file in the same directory as the final
2163 * 'filename'
2164 *
2165 * We want to avoid cross-directory filename renames, because those
2166 * can have problems on various filesystems (FAT, NFS, Coda).
2167 */
2168static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2169{
2170 int fd, dirlen = directory_size(filename);
2171
2172 if (dirlen + 20 > bufsiz) {
2173 errno = ENAMETOOLONG;
2174 return -1;
2175 }
2176 memcpy(buffer, filename, dirlen);
2177 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2178 fd = mkstemp(buffer);
2179 if (fd < 0 && dirlen) {
2180 /* Make sure the directory exists */
6ff6af62 2181 memcpy(buffer, filename, dirlen);
5723fe7e 2182 buffer[dirlen-1] = 0;
3bfaf018 2183 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2184 return -1;
2185
2186 /* Try again */
2187 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2188 fd = mkstemp(buffer);
2189 }
2190 return fd;
2191}
2192
bbac7311
NP
2193static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2194 void *buf, unsigned long len, time_t mtime)
0fcfd160 2195{
bbac7311 2196 int fd, size, ret;
bf0f910d 2197 unsigned char *compressed;
0fcfd160 2198 z_stream stream;
706bc531 2199 char *filename;
aac17941 2200 static char tmpfile[PATH_MAX];
a44c9a5e 2201
972a9155 2202 filename = sha1_file_name(sha1);
5723fe7e 2203 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
aac17941 2204 if (fd < 0) {
916d081b
PB
2205 if (errno == EPERM)
2206 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2207 else
2208 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2209 }
2210
0fcfd160
LT
2211 /* Set it up */
2212 memset(&stream, 0, sizeof(stream));
12f6c308 2213 deflateInit(&stream, zlib_compression_level);
93821bd9 2214 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2215 compressed = xmalloc(size);
0fcfd160
LT
2216
2217 /* Compress it */
0fcfd160
LT
2218 stream.next_out = compressed;
2219 stream.avail_out = size;
a44c9a5e
LT
2220
2221 /* First header.. */
d65a16f6 2222 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2223 stream.avail_in = hdrlen;
726f852b
NP
2224 while (deflate(&stream, 0) == Z_OK)
2225 /* nothing */;
a44c9a5e
LT
2226
2227 /* Then the data itself.. */
2228 stream.next_in = buf;
2229 stream.avail_in = len;
ac54c277
LT
2230 ret = deflate(&stream, Z_FINISH);
2231 if (ret != Z_STREAM_END)
2232 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2233
2234 ret = deflateEnd(&stream);
2235 if (ret != Z_OK)
2236 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2237
0fcfd160
LT
2238 size = stream.total_out;
2239
4d548150
LT
2240 if (write_buffer(fd, compressed, size) < 0)
2241 die("unable to write sha1 file");
e9039dd3 2242 close_sha1_file(fd);
383f85b7 2243 free(compressed);
0fcfd160 2244
bbac7311
NP
2245 if (mtime) {
2246 struct utimbuf utb;
2247 utb.actime = mtime;
2248 utb.modtime = mtime;
2249 if (utime(tmpfile, &utb) < 0)
2250 warning("failed utime() on %s: %s",
2251 tmpfile, strerror(errno));
2252 }
2253
230f1322 2254 return move_temp_to_file(tmpfile, filename);
0fcfd160 2255}
8237b185 2256
bbac7311
NP
2257int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2258{
2259 unsigned char sha1[20];
2260 char hdr[32];
2261 int hdrlen;
2262
2263 /* Normally if we have it in the pack then we do not bother writing
2264 * it out into .git/objects/??/?{38} file.
2265 */
2266 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2267 if (returnsha1)
2268 hashcpy(returnsha1, sha1);
2269 if (has_sha1_file(sha1))
2270 return 0;
2271 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2272}
2273
2274int force_object_loose(const unsigned char *sha1, time_t mtime)
2275{
bbac7311
NP
2276 void *buf;
2277 unsigned long len;
2278 enum object_type type;
2279 char hdr[32];
2280 int hdrlen;
2281
c529d75a 2282 if (has_loose_object(sha1))
bbac7311
NP
2283 return 0;
2284 buf = read_packed_sha1(sha1, &type, &len);
2285 if (!buf)
2286 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2287 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2288 return write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2289}
2290
bf592c50
DB
2291int has_pack_index(const unsigned char *sha1)
2292{
2293 struct stat st;
2294 if (stat(sha1_pack_index_name(sha1), &st))
2295 return 0;
2296 return 1;
2297}
2298
2299int has_pack_file(const unsigned char *sha1)
2300{
2301 struct stat st;
2302 if (stat(sha1_pack_name(sha1), &st))
2303 return 0;
2304 return 1;
2305}
2306
106d710b 2307int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2308{
2309 struct pack_entry e;
106d710b 2310 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2311}
2312
8237b185
DB
2313int has_sha1_file(const unsigned char *sha1)
2314{
1f688557
JH
2315 struct pack_entry e;
2316
106d710b 2317 if (find_pack_entry(sha1, &e, NULL))
1f688557 2318 return 1;
c529d75a 2319 return has_loose_object(sha1);
8237b185 2320}
74400e71 2321
e7332f96
BE
2322int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2323{
fd17f5b5 2324 struct strbuf buf;
e7332f96 2325 int ret;
e7332f96 2326
fd17f5b5
PH
2327 strbuf_init(&buf, 0);
2328 if (strbuf_read(&buf, fd, 4096) < 0) {
2329 strbuf_release(&buf);
024510c8
DB
2330 return -1;
2331 }
e7332f96 2332
024510c8 2333 if (!type)
8e440259 2334 type = blob_type;
024510c8 2335 if (write_object)
fd17f5b5 2336 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
abdc3fc8 2337 else
fd17f5b5
PH
2338 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
2339 strbuf_release(&buf);
2340
024510c8
DB
2341 return ret;
2342}
2343
edaec3fb 2344int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
53bca91a 2345 enum object_type type, const char *path)
74400e71 2346{
dc49cd76 2347 size_t size = xsize_t(st->st_size);
3a55602e 2348 void *buf = NULL;
6c510bee 2349 int ret, re_allocated = 0;
74400e71 2350
74400e71 2351 if (size)
c4712e45 2352 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 2353 close(fd);
74400e71 2354
7672db20 2355 if (!type)
edaec3fb 2356 type = OBJ_BLOB;
6c510bee
LT
2357
2358 /*
2359 * Convert blobs to git internal format
2360 */
d0d8e14d 2361 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
5ecd293d
PH
2362 struct strbuf nbuf;
2363 strbuf_init(&nbuf, 0);
21e5ad50
SP
2364 if (convert_to_git(path, buf, size, &nbuf,
2365 write_object ? safe_crlf : 0)) {
ac78e548 2366 munmap(buf, size);
b315c5c0 2367 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2368 re_allocated = 1;
2369 }
2370 }
2371
7672db20 2372 if (write_object)
edaec3fb 2373 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2374 else
edaec3fb 2375 ret = hash_sha1_file(buf, size, typename(type), sha1);
6c510bee
LT
2376 if (re_allocated) {
2377 free(buf);
2378 return ret;
2379 }
aac17941
LT
2380 if (size)
2381 munmap(buf, size);
2382 return ret;
74400e71 2383}
ec1fcc16
JH
2384
2385int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2386{
2387 int fd;
2388 char *target;
dc49cd76 2389 size_t len;
ec1fcc16
JH
2390
2391 switch (st->st_mode & S_IFMT) {
2392 case S_IFREG:
2393 fd = open(path, O_RDONLY);
2394 if (fd < 0)
2395 return error("open(\"%s\"): %s", path,
2396 strerror(errno));
53bca91a 2397 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2398 return error("%s: failed to insert into database",
2399 path);
2400 break;
2401 case S_IFLNK:
dc49cd76
SP
2402 len = xsize_t(st->st_size);
2403 target = xmalloc(len + 1);
2404 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2405 char *errstr = strerror(errno);
2406 free(target);
2407 return error("readlink(\"%s\"): %s", path,
2408 errstr);
2409 }
abdc3fc8 2410 if (!write_object)
dc49cd76
SP
2411 hash_sha1_file(target, len, blob_type, sha1);
2412 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2413 return error("%s: failed to insert into database",
2414 path);
2415 free(target);
2416 break;
f35a6d3b
LT
2417 case S_IFDIR:
2418 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2419 default:
2420 return error("%s: unsupported file type", path);
2421 }
2422 return 0;
2423}
a69e5429
JH
2424
2425int read_pack_header(int fd, struct pack_header *header)
2426{
c697ad14
HO
2427 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2428 /* "eof before pack header was fully read" */
2429 return PH_ERROR_EOF;
2430
a69e5429
JH
2431 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2432 /* "protocol error (pack signature mismatch detected)" */
2433 return PH_ERROR_PACK_SIGNATURE;
2434 if (!pack_version_ok(header->hdr_version))
2435 /* "protocol error (pack version unsupported)" */
2436 return PH_ERROR_PROTOCOL;
2437 return 0;
2438}