optimize verify-pack a bit
[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
8e21d63b
JK
119int safe_create_leading_directories_const(const char *path)
120{
121 /* path points to cache entries, so xstrdup before messing with it */
122 char *buf = xstrdup(path);
123 int result = safe_create_leading_directories(buf);
124 free(buf);
125 return result;
126}
127
3bfaf018 128char *sha1_to_hex(const unsigned char *sha1)
0fcfd160 129{
dcb3450f
LT
130 static int bufno;
131 static char hexbuffer[4][50];
0fcfd160 132 static const char hex[] = "0123456789abcdef";
dcb3450f 133 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
134 int i;
135
136 for (i = 0; i < 20; i++) {
137 unsigned int val = *sha1++;
138 *buf++ = hex[val >> 4];
139 *buf++ = hex[val & 0xf];
140 }
1e80e044
JS
141 *buf = '\0';
142
0fcfd160
LT
143 return buffer;
144}
145
ace1534d
JH
146static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
147{
148 int i;
149 for (i = 0; i < 20; i++) {
150 static char hex[] = "0123456789abcdef";
151 unsigned int val = sha1[i];
152 char *pos = pathbuf + i*2 + (i > 0);
153 *pos++ = hex[val >> 4];
154 *pos = hex[val & 0xf];
155 }
156}
157
0fcfd160
LT
158/*
159 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 160 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 161 * filename.
ace1534d
JH
162 *
163 * Also note that this returns the location for creating. Reading
164 * SHA1 file can happen from any alternate directory listed in the
d19938ab 165 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 166 * the primary object database.
0fcfd160
LT
167 */
168char *sha1_file_name(const unsigned char *sha1)
169{
0fcfd160
LT
170 static char *name, *base;
171
172 if (!base) {
d19938ab 173 const char *sha1_file_directory = get_object_directory();
0fcfd160 174 int len = strlen(sha1_file_directory);
812666c8 175 base = xmalloc(len + 60);
0fcfd160
LT
176 memcpy(base, sha1_file_directory, len);
177 memset(base+len, 0, 60);
178 base[len] = '/';
179 base[len+3] = '/';
180 name = base + len + 1;
181 }
ace1534d 182 fill_sha1_path(name, sha1);
0fcfd160
LT
183 return base;
184}
185
633f43e1 186static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 187 char **name, char **base, const char *which)
bf592c50
DB
188{
189 static const char hex[] = "0123456789abcdef";
633f43e1 190 char *buf;
bf592c50
DB
191 int i;
192
633f43e1 193 if (!*base) {
bf592c50
DB
194 const char *sha1_file_directory = get_object_directory();
195 int len = strlen(sha1_file_directory);
633f43e1 196 *base = xmalloc(len + 60);
6eec46bd
JH
197 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
198 sha1_file_directory, which);
633f43e1 199 *name = *base + len + 11;
bf592c50
DB
200 }
201
633f43e1 202 buf = *name;
bf592c50
DB
203
204 for (i = 0; i < 20; i++) {
205 unsigned int val = *sha1++;
206 *buf++ = hex[val >> 4];
207 *buf++ = hex[val & 0xf];
208 }
a6080a0a 209
633f43e1 210 return *base;
bf592c50
DB
211}
212
633f43e1 213char *sha1_pack_name(const unsigned char *sha1)
bf592c50 214{
633f43e1 215 static char *name, *base;
bf592c50 216
6eec46bd 217 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 218}
bf592c50 219
633f43e1
HO
220char *sha1_pack_index_name(const unsigned char *sha1)
221{
222 static char *name, *base;
a6080a0a 223
6eec46bd 224 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
225}
226
d5a63b99
JH
227struct alternate_object_database *alt_odb_list;
228static struct alternate_object_database **alt_odb_tail;
ace1534d 229
c2f493a4
MW
230static void read_info_alternates(const char * alternates, int depth);
231
ddd5d056
JH
232/*
233 * Prepare alternate object database registry.
d5a63b99
JH
234 *
235 * The variable alt_odb_list points at the list of struct
236 * alternate_object_database. The elements on this list come from
237 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
238 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
239 * whose contents is similar to that environment variable but can be
240 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
241 * contains "/the/directory/corresponding/to/.git/objects/...", while
242 * its name points just after the slash at the end of ".git/objects/"
243 * in the example above, and has enough space to hold 40-byte hex
244 * SHA1, an extra slash for the first level indirection, and the
245 * terminating NUL.
ddd5d056 246 */
c2f493a4 247static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 248{
c2f493a4 249 struct stat st;
1494e038 250 const char *objdir = get_object_directory();
c2f493a4
MW
251 struct alternate_object_database *ent;
252 struct alternate_object_database *alt;
253 /* 43 = 40-byte + 2 '/' + terminating NUL */
254 int pfxlen = len;
255 int entlen = pfxlen + 43;
ccfd3e99 256 int base_len = -1;
d5a63b99 257
85dadc38 258 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
259 /* Relative alt-odb */
260 if (base_len < 0)
261 base_len = strlen(relative_base) + 1;
262 entlen += base_len;
263 pfxlen += base_len;
264 }
265 ent = xmalloc(sizeof(*ent) + entlen);
266
85dadc38 267 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
268 memcpy(ent->base, relative_base, base_len - 1);
269 ent->base[base_len - 1] = '/';
270 memcpy(ent->base + base_len, entry, len);
271 }
272 else
273 memcpy(ent->base, entry, pfxlen);
274
275 ent->name = ent->base + pfxlen + 1;
276 ent->base[pfxlen + 3] = '/';
277 ent->base[pfxlen] = ent->base[entlen-1] = 0;
278
279 /* Detect cases where alternate disappeared */
280 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
281 error("object directory %s does not exist; "
282 "check .git/objects/info/alternates.",
283 ent->base);
284 free(ent);
285 return -1;
286 }
287
288 /* Prevent the common mistake of listing the same
289 * thing twice, or object directory itself.
290 */
291 for (alt = alt_odb_list; alt; alt = alt->next) {
292 if (!memcmp(ent->base, alt->base, pfxlen)) {
293 free(ent);
294 return -1;
295 }
296 }
297 if (!memcmp(ent->base, objdir, pfxlen)) {
298 free(ent);
299 return -1;
300 }
301
302 /* add the alternate entry */
303 *alt_odb_tail = ent;
304 alt_odb_tail = &(ent->next);
305 ent->next = NULL;
306
307 /* recursively add alternates */
308 read_info_alternates(ent->base, depth + 1);
309
310 ent->base[pfxlen] = '/';
311
312 return 0;
313}
314
315static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
316 const char *relative_base, int depth)
317{
318 const char *cp, *last;
319
320 if (depth > 5) {
321 error("%s: ignoring alternate object stores, nesting too deep.",
322 relative_base);
323 return;
324 }
325
d5a63b99 326 last = alt;
9577e7e3
JH
327 while (last < ep) {
328 cp = last;
329 if (cp < ep && *cp == '#') {
330 while (cp < ep && *cp != sep)
331 cp++;
332 last = cp + 1;
333 continue;
334 }
c2f493a4
MW
335 while (cp < ep && *cp != sep)
336 cp++;
d5a63b99 337 if (last != cp) {
85dadc38 338 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
339 error("%s: ignoring relative alternate object store %s",
340 relative_base, last);
341 } else {
342 link_alt_odb_entry(last, cp - last,
343 relative_base, depth);
1494e038 344 }
d5a63b99 345 }
9577e7e3 346 while (cp < ep && *cp == sep)
d5a63b99
JH
347 cp++;
348 last = cp;
9577e7e3 349 }
d5a63b99
JH
350}
351
c2f493a4 352static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 353{
9577e7e3 354 char *map;
dc49cd76 355 size_t mapsz;
d5a63b99 356 struct stat st;
9cb18f56
JM
357 const char alt_file_name[] = "info/alternates";
358 /* Given that relative_base is no longer than PATH_MAX,
359 ensure that "path" has enough space to append "/", the
360 file name, "info/alternates", and a trailing NUL. */
361 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 362 int fd;
d5a63b99 363
9cb18f56 364 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
365 fd = open(path, O_RDONLY);
366 if (fd < 0)
367 return;
368 if (fstat(fd, &st) || (st.st_size == 0)) {
369 close(fd);
9a217f2a 370 return;
ace1534d 371 }
dc49cd76
SP
372 mapsz = xsize_t(st.st_size);
373 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 374 close(fd);
d5a63b99 375
dc49cd76 376 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 377
dc49cd76 378 munmap(map, mapsz);
ace1534d
JH
379}
380
bef70b22
DB
381void add_to_alternates_file(const char *reference)
382{
383 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
384 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), 1);
385 char *alt = mkpath("%s/objects\n", reference);
386 write_or_die(fd, alt, strlen(alt));
387 if (commit_lock_file(lock))
388 die("could not close alternates file");
389 if (alt_odb_tail)
390 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
391}
392
c2f493a4
MW
393void prepare_alt_odb(void)
394{
554fe20d 395 const char *alt;
c2f493a4 396
7dc24aa5
SP
397 if (alt_odb_tail)
398 return;
399
c2f493a4
MW
400 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
401 if (!alt) alt = "";
402
c2f493a4
MW
403 alt_odb_tail = &alt_odb_list;
404 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
405
406 read_info_alternates(get_object_directory(), 0);
407}
408
c529d75a 409static int has_loose_object(const unsigned char *sha1)
ace1534d 410{
ace1534d 411 char *name = sha1_file_name(sha1);
d5a63b99 412 struct alternate_object_database *alt;
ace1534d 413
c529d75a
LT
414 if (!access(name, F_OK))
415 return 1;
9a217f2a 416 prepare_alt_odb();
d5a63b99
JH
417 for (alt = alt_odb_list; alt; alt = alt->next) {
418 name = alt->name;
ace1534d 419 fill_sha1_path(name, sha1);
c529d75a
LT
420 if (!access(alt->base, F_OK))
421 return 1;
ace1534d 422 }
c529d75a 423 return 0;
ace1534d
JH
424}
425
60bb8b14 426static unsigned int pack_used_ctr;
a53128b6
SP
427static unsigned int pack_mmap_calls;
428static unsigned int peak_pack_open_windows;
429static unsigned int pack_open_windows;
430static size_t peak_pack_mapped;
60bb8b14 431static size_t pack_mapped;
9a217f2a 432struct packed_git *packed_git;
1f688557 433
b79d18c9 434void pack_report(void)
a53128b6
SP
435{
436 fprintf(stderr,
e05db0fd
PR
437 "pack_report: getpagesize() = %10" SZ_FMT "\n"
438 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
439 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
440 sz_fmt(getpagesize()),
441 sz_fmt(packed_git_window_size),
442 sz_fmt(packed_git_limit));
a53128b6
SP
443 fprintf(stderr,
444 "pack_report: pack_used_ctr = %10u\n"
445 "pack_report: pack_mmap_calls = %10u\n"
446 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
447 "pack_report: pack_mapped = "
448 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
449 pack_used_ctr,
450 pack_mmap_calls,
451 pack_open_windows, peak_pack_open_windows,
9e42d6a1 452 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
453}
454
42873078 455static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
456{
457 void *idx_map;
42873078 458 struct pack_idx_header *hdr;
dc49cd76 459 size_t idx_size;
74e34e1f 460 uint32_t version, nr, i, *index;
e93ec6f9 461 int fd = open(path, O_RDONLY);
1f688557 462 struct stat st;
42873078 463
1f688557
JH
464 if (fd < 0)
465 return -1;
466 if (fstat(fd, &st)) {
467 close(fd);
468 return -1;
469 }
dc49cd76 470 idx_size = xsize_t(st.st_size);
2d88451b
SP
471 if (idx_size < 4 * 256 + 20 + 20) {
472 close(fd);
473 return error("index file %s is too small", path);
474 }
c4712e45 475 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 476 close(fd);
1f688557 477
42873078
NP
478 hdr = idx_map;
479 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
480 version = ntohl(hdr->idx_version);
481 if (version < 2 || version > 2) {
482 munmap(idx_map, idx_size);
483 return error("index file %s is version %d"
484 " and is not supported by this binary"
485 " (try upgrading GIT to a newer version)",
486 path, version);
487 }
488 } else
489 version = 1;
df1b059d 490
1f688557 491 nr = 0;
42873078 492 index = idx_map;
74e34e1f
NP
493 if (version > 1)
494 index += 2; /* skip index header */
1f688557 495 for (i = 0; i < 256; i++) {
326bf396 496 uint32_t n = ntohl(index[i]);
2d88451b
SP
497 if (n < nr) {
498 munmap(idx_map, idx_size);
df1b059d 499 return error("non-monotonic index %s", path);
2d88451b 500 }
1f688557
JH
501 nr = n;
502 }
503
74e34e1f
NP
504 if (version == 1) {
505 /*
506 * Total size:
507 * - 256 index entries 4 bytes each
508 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
509 * - 20-byte SHA1 of the packfile
510 * - 20-byte SHA1 file checksum
511 */
512 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
513 munmap(idx_map, idx_size);
eef427a0 514 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
515 }
516 } else if (version == 2) {
517 /*
518 * Minimum size:
519 * - 8 bytes of header
520 * - 256 index entries 4 bytes each
521 * - 20-byte sha1 entry * nr
522 * - 4-byte crc entry * nr
523 * - 4-byte offset entry * nr
524 * - 20-byte SHA1 of the packfile
525 * - 20-byte SHA1 file checksum
526 * And after the 4-byte offset table might be a
527 * variable sized table containing 8-byte entries
528 * for offsets larger than 2^31.
529 */
530 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
531 unsigned long max_size = min_size;
532 if (nr)
533 max_size += (nr - 1)*8;
534 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 535 munmap(idx_map, idx_size);
eef427a0 536 return error("wrong index v2 file size in %s", path);
74e34e1f 537 }
7109c889
JH
538 if (idx_size != min_size &&
539 /*
540 * make sure we can deal with large pack offsets.
541 * 31-bit signed offset won't be enough, neither
542 * 32-bit unsigned one will be.
543 */
544 (sizeof(off_t) <= 4)) {
545 munmap(idx_map, idx_size);
546 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 547 }
2d88451b 548 }
1f688557 549
74e34e1f 550 p->index_version = version;
42873078
NP
551 p->index_data = idx_map;
552 p->index_size = idx_size;
57059091 553 p->num_objects = nr;
1f688557
JH
554 return 0;
555}
556
bc8e478a 557int open_pack_index(struct packed_git *p)
d079837e
SP
558{
559 char *idx_name;
560 int ret;
561
562 if (p->index_data)
563 return 0;
564
565 idx_name = xstrdup(p->pack_name);
566 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
567 ret = check_packed_git_idx(idx_name, p);
568 free(idx_name);
569 return ret;
570}
571
11daf39b
SP
572static void scan_windows(struct packed_git *p,
573 struct packed_git **lru_p,
574 struct pack_window **lru_w,
575 struct pack_window **lru_l)
1f688557 576{
11daf39b
SP
577 struct pack_window *w, *w_l;
578
579 for (w_l = NULL, w = p->windows; w; w = w->next) {
580 if (!w->inuse_cnt) {
581 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
582 *lru_p = p;
583 *lru_w = w;
584 *lru_l = w_l;
54044bf8 585 }
54044bf8 586 }
11daf39b 587 w_l = w;
f9253394 588 }
11daf39b
SP
589}
590
d1efefa4 591static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
592{
593 struct packed_git *p, *lru_p = NULL;
594 struct pack_window *lru_w = NULL, *lru_l = NULL;
595
596 if (current)
597 scan_windows(current, &lru_p, &lru_w, &lru_l);
598 for (p = packed_git; p; p = p->next)
599 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
600 if (lru_p) {
601 munmap(lru_w->base, lru_w->len);
602 pack_mapped -= lru_w->len;
603 if (lru_l)
604 lru_l->next = lru_w->next;
605 else {
606 lru_p->windows = lru_w->next;
d1efefa4 607 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
608 close(lru_p->pack_fd);
609 lru_p->pack_fd = -1;
610 }
611 }
612 free(lru_w);
a53128b6 613 pack_open_windows--;
54044bf8
SP
614 return 1;
615 }
616 return 0;
f9253394
JH
617}
618
d1efefa4 619void release_pack_memory(size_t need, int fd)
97bfeb34
SP
620{
621 size_t cur = pack_mapped;
d1efefa4 622 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
623 ; /* nothing */
624}
625
c9ced051
SP
626void close_pack_windows(struct packed_git *p)
627{
628 while (p->windows) {
629 struct pack_window *w = p->windows;
630
631 if (w->inuse_cnt)
632 die("pack '%s' still has open windows to it",
633 p->pack_name);
634 munmap(w->base, w->len);
635 pack_mapped -= w->len;
636 pack_open_windows--;
637 p->windows = w->next;
638 free(w);
639 }
640}
641
03e79c88 642void unuse_pack(struct pack_window **w_cursor)
f9253394 643{
03e79c88
SP
644 struct pack_window *w = *w_cursor;
645 if (w) {
646 w->inuse_cnt--;
647 *w_cursor = NULL;
648 }
1f688557
JH
649}
650
3cf8b462
SP
651/*
652 * Do not call this directly as this leaks p->pack_fd on error return;
653 * call open_packed_git() instead.
654 */
655static int open_packed_git_1(struct packed_git *p)
1f688557 656{
9bc879c1
SP
657 struct stat st;
658 struct pack_header hdr;
659 unsigned char sha1[20];
660 unsigned char *idx_sha1;
2c039da8 661 long fd_flag;
9bc879c1 662
d079837e
SP
663 if (!p->index_data && open_pack_index(p))
664 return error("packfile %s index unavailable", p->pack_name);
665
9bc879c1
SP
666 p->pack_fd = open(p->pack_name, O_RDONLY);
667 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 668 return -1;
9bc879c1
SP
669
670 /* If we created the struct before we had the pack we lack size. */
bf592c50 671 if (!p->pack_size) {
bf592c50 672 if (!S_ISREG(st.st_mode))
072db278 673 return error("packfile %s not a regular file", p->pack_name);
bf592c50 674 p->pack_size = st.st_size;
9bc879c1 675 } else if (p->pack_size != st.st_size)
072db278 676 return error("packfile %s size changed", p->pack_name);
9bc879c1 677
2c039da8
JH
678 /* We leave these file descriptors open with sliding mmap;
679 * there is no point keeping them open across exec(), though.
680 */
681 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
682 if (fd_flag < 0)
072db278 683 return error("cannot determine file descriptor flags");
2c039da8
JH
684 fd_flag |= FD_CLOEXEC;
685 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 686 return error("cannot set FD_CLOEXEC");
2c039da8 687
9bc879c1 688 /* Verify we recognize this pack file format. */
e6e2bd62 689 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 690 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 691 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 692 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 693 if (!pack_version_ok(hdr.hdr_version))
072db278 694 return error("packfile %s is version %u and not supported"
9bc879c1
SP
695 " (try upgrading GIT to a newer version)",
696 p->pack_name, ntohl(hdr.hdr_version));
697
698 /* Verify the pack matches its index. */
57059091 699 if (p->num_objects != ntohl(hdr.hdr_entries))
072db278 700 return error("packfile %s claims to have %u objects"
57059091
NP
701 " while index indicates %u objects",
702 p->pack_name, ntohl(hdr.hdr_entries),
703 p->num_objects);
9bc879c1 704 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 705 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 706 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 707 return error("packfile %s signature is unavailable", p->pack_name);
42873078 708 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 709 if (hashcmp(sha1, idx_sha1))
072db278
SP
710 return error("packfile %s does not match index", p->pack_name);
711 return 0;
9bc879c1
SP
712}
713
3cf8b462
SP
714static int open_packed_git(struct packed_git *p)
715{
716 if (!open_packed_git_1(p))
717 return 0;
718 if (p->pack_fd != -1) {
719 close(p->pack_fd);
720 p->pack_fd = -1;
721 }
722 return -1;
723}
724
c4001d92 725static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
726{
727 /* We must promise at least 20 bytes (one hash) after the
728 * offset is available from this window, otherwise the offset
729 * is not actually in this window and a different window (which
730 * has that one hash excess) must be used. This is to support
731 * the object header and delta base parsing routines below.
732 */
733 off_t win_off = win->offset;
734 return win_off <= offset
735 && (offset + 20) <= (win_off + win->len);
736}
737
03e79c88
SP
738unsigned char* use_pack(struct packed_git *p,
739 struct pack_window **w_cursor,
c4001d92 740 off_t offset,
03e79c88 741 unsigned int *left)
9bc879c1 742{
60bb8b14 743 struct pack_window *win = *w_cursor;
03e79c88 744
072db278
SP
745 if (p->pack_fd == -1 && open_packed_git(p))
746 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
747
748 /* Since packfiles end in a hash of their content and its
749 * pointless to ask for an offset into the middle of that
750 * hash, and the in_window function above wouldn't match
751 * don't allow an offset too close to the end of the file.
752 */
753 if (offset > (p->pack_size - 20))
754 die("offset beyond end of packfile (truncated pack?)");
755
756 if (!win || !in_window(win, offset)) {
757 if (win)
758 win->inuse_cnt--;
759 for (win = p->windows; win; win = win->next) {
760 if (in_window(win, offset))
761 break;
762 }
763 if (!win) {
78a28df9 764 size_t window_align = packed_git_window_size / 2;
dc49cd76 765 off_t len;
60bb8b14 766 win = xcalloc(1, sizeof(*win));
78a28df9 767 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
768 len = p->pack_size - win->offset;
769 if (len > packed_git_window_size)
770 len = packed_git_window_size;
771 win->len = (size_t)len;
60bb8b14 772 pack_mapped += win->len;
11daf39b 773 while (packed_git_limit < pack_mapped
d1efefa4 774 && unuse_one_window(p, p->pack_fd))
60bb8b14 775 ; /* nothing */
c4712e45 776 win->base = xmmap(NULL, win->len,
60bb8b14
SP
777 PROT_READ, MAP_PRIVATE,
778 p->pack_fd, win->offset);
779 if (win->base == MAP_FAILED)
73b4e4be
SP
780 die("packfile %s cannot be mapped: %s",
781 p->pack_name,
782 strerror(errno));
a53128b6
SP
783 pack_mmap_calls++;
784 pack_open_windows++;
785 if (pack_mapped > peak_pack_mapped)
786 peak_pack_mapped = pack_mapped;
787 if (pack_open_windows > peak_pack_open_windows)
788 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
789 win->next = p->windows;
790 p->windows = win;
791 }
1f688557 792 }
03e79c88
SP
793 if (win != *w_cursor) {
794 win->last_used = pack_used_ctr++;
795 win->inuse_cnt++;
796 *w_cursor = win;
797 }
60bb8b14 798 offset -= win->offset;
03e79c88 799 if (left)
dc49cd76 800 *left = win->len - xsize_t(offset);
03e79c88 801 return win->base + offset;
1f688557
JH
802}
803
27d69a46
NP
804static struct packed_git *alloc_packed_git(int extra)
805{
806 struct packed_git *p = xmalloc(sizeof(*p) + extra);
807 memset(p, 0, sizeof(*p));
808 p->pack_fd = -1;
809 return p;
810}
811
42873078 812struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
813{
814 struct stat st;
27d69a46 815 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 816
42873078
NP
817 /*
818 * Make sure a corresponding .pack file exists and that
819 * the index looks sane.
820 */
821 path_len -= strlen(".idx");
27d69a46
NP
822 if (path_len < 1) {
823 free(p);
1f688557 824 return NULL;
27d69a46 825 }
42873078
NP
826 memcpy(p->pack_name, path, path_len);
827 strcpy(p->pack_name + path_len, ".pack");
d079837e 828 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 829 free(p);
1f688557
JH
830 return NULL;
831 }
42873078 832
1f688557
JH
833 /* ok, it looks sane as far as we can check without
834 * actually mapping the pack file.
835 */
1f688557 836 p->pack_size = st.st_size;
9d835df2 837 p->pack_local = local;
b867092f 838 p->mtime = st.st_mtime;
42873078
NP
839 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
840 hashclr(p->sha1);
1f688557
JH
841 return p;
842}
843
bf592c50 844struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e 845{
79c6dca4 846 const char *idx_path = sha1_pack_index_name(sha1);
42873078 847 const char *path = sha1_pack_name(sha1);
27d69a46 848 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 849
27d69a46
NP
850 strcpy(p->pack_name, path);
851 hashcpy(p->sha1, sha1);
42873078
NP
852 if (check_packed_git_idx(idx_path, p)) {
853 free(p);
bf592c50 854 return NULL;
42873078 855 }
bf592c50 856
bf592c50
DB
857 return p;
858}
859
860void install_packed_git(struct packed_git *pack)
861{
862 pack->next = packed_git;
863 packed_git = pack;
864}
865
9d835df2 866static void prepare_packed_git_one(char *objdir, int local)
1f688557 867{
9cb18f56
JM
868 /* Ensure that this buffer is large enough so that we can
869 append "/pack/" without clobbering the stack even if
870 strlen(objdir) were PATH_MAX. */
871 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
872 int len;
873 DIR *dir;
874 struct dirent *de;
875
876 sprintf(path, "%s/pack", objdir);
877 len = strlen(path);
878 dir = opendir(path);
b5b16990 879 if (!dir) {
26125f6b 880 if (errno != ENOENT)
bd2afde8 881 error("unable to open object pack directory: %s: %s",
26125f6b 882 path, strerror(errno));
1f688557 883 return;
b5b16990 884 }
1f688557
JH
885 path[len++] = '/';
886 while ((de = readdir(dir)) != NULL) {
887 int namelen = strlen(de->d_name);
888 struct packed_git *p;
889
5bb1cda5 890 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
891 continue;
892
9cb18f56
JM
893 if (len + namelen + 1 > sizeof(path))
894 continue;
895
54a15a8d 896 /* Don't reopen a pack we already have. */
1f688557 897 strcpy(path + len, de->d_name);
86f7780c
JK
898 for (p = packed_git; p; p = p->next) {
899 if (!memcmp(path, p->pack_name, len + namelen - 4))
900 break;
901 }
902 if (p)
903 continue;
54a15a8d
SP
904 /* See if it really is a valid .idx file with corresponding
905 * .pack file that we can map.
906 */
9d835df2 907 p = add_packed_git(path, len + namelen, local);
1f688557
JH
908 if (!p)
909 continue;
625e9421 910 install_packed_git(p);
1f688557 911 }
5b35bcd5 912 closedir(dir);
1f688557
JH
913}
914
b867092f
JH
915static int sort_pack(const void *a_, const void *b_)
916{
917 struct packed_git *a = *((struct packed_git **)a_);
918 struct packed_git *b = *((struct packed_git **)b_);
919 int st;
920
921 /*
922 * Local packs tend to contain objects specific to our
923 * variant of the project than remote ones. In addition,
924 * remote ones could be on a network mounted filesystem.
925 * Favor local ones for these reasons.
926 */
927 st = a->pack_local - b->pack_local;
928 if (st)
929 return -st;
930
931 /*
932 * Younger packs tend to contain more recent objects,
933 * and more recent objects tend to get accessed more
934 * often.
935 */
936 if (a->mtime < b->mtime)
937 return 1;
938 else if (a->mtime == b->mtime)
939 return 0;
940 return -1;
941}
942
943static void rearrange_packed_git(void)
944{
945 struct packed_git **ary, *p;
946 int i, n;
947
948 for (n = 0, p = packed_git; p; p = p->next)
949 n++;
950 if (n < 2)
951 return;
952
953 /* prepare an array of packed_git for easier sorting */
954 ary = xcalloc(n, sizeof(struct packed_git *));
955 for (n = 0, p = packed_git; p; p = p->next)
956 ary[n++] = p;
957
958 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
959
960 /* link them back again */
961 for (i = 0; i < n - 1; i++)
962 ary[i]->next = ary[i + 1];
963 ary[n - 1]->next = NULL;
964 packed_git = ary[0];
965
966 free(ary);
967}
968
637cdd9d 969static int prepare_packed_git_run_once = 0;
9a217f2a 970void prepare_packed_git(void)
1f688557 971{
d5a63b99 972 struct alternate_object_database *alt;
1f688557 973
637cdd9d 974 if (prepare_packed_git_run_once)
1f688557 975 return;
9d835df2 976 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 977 prepare_alt_odb();
d5a63b99 978 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 979 alt->name[-1] = 0;
9d835df2 980 prepare_packed_git_one(alt->base, 0);
1494e038 981 alt->name[-1] = '/';
1f688557 982 }
b867092f 983 rearrange_packed_git();
637cdd9d
JK
984 prepare_packed_git_run_once = 1;
985}
986
fc04c412 987void reprepare_packed_git(void)
637cdd9d
JK
988{
989 prepare_packed_git_run_once = 0;
990 prepare_packed_git();
1f688557
JH
991}
992
8eca0b47
NP
993static void mark_bad_packed_object(struct packed_git *p,
994 const unsigned char *sha1)
995{
996 unsigned i;
997 for (i = 0; i < p->num_bad_objects; i++)
998 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
999 return;
1000 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1001 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1002 p->num_bad_objects++;
1003}
1004
5d6ccf5c 1005int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
1006{
1007 unsigned char real_sha1[20];
7cfb5f36 1008 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 1009 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1010}
1011
44d1c19e
LT
1012static int git_open_noatime(const char *name)
1013{
1014 static int sha1_file_open_flag = O_NOATIME;
1015 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1016
1017 /* Might the failure be due to O_NOATIME? */
1018 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1019 fd = open(name, O_RDONLY);
1020 if (fd >= 0)
1021 sha1_file_open_flag = 0;
1022 }
1023 return fd;
1024}
1025
1026static int open_sha1_file(const unsigned char *sha1)
1027{
1028 int fd;
1029 char *name = sha1_file_name(sha1);
1030 struct alternate_object_database *alt;
1031
1032 fd = git_open_noatime(name);
1033 if (fd >= 0)
1034 return fd;
1035
1036 prepare_alt_odb();
1037 errno = ENOENT;
1038 for (alt = alt_odb_list; alt; alt = alt->next) {
1039 name = alt->name;
1040 fill_sha1_path(name, sha1);
1041 fd = git_open_noatime(alt->base);
1042 if (fd >= 0)
1043 return fd;
1044 }
1045 return -1;
1046}
1047
4175e9e3 1048static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1049{
0fcfd160 1050 void *map;
144bde78 1051 int fd;
ace1534d 1052
44d1c19e
LT
1053 fd = open_sha1_file(sha1);
1054 map = NULL;
1055 if (fd >= 0) {
1056 struct stat st;
0fcfd160 1057
44d1c19e
LT
1058 if (!fstat(fd, &st)) {
1059 *size = xsize_t(st.st_size);
1060 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1061 }
44d1c19e 1062 close(fd);
0fcfd160 1063 }
0fcfd160
LT
1064 return map;
1065}
1066
726f852b 1067static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1068{
1069 unsigned int word;
1070
1071 /*
1072 * Is it a zlib-compressed buffer? If so, the first byte
1073 * must be 0x78 (15-bit window size, deflated), and the
1074 * first 16-bit word is evenly divisible by 31
1075 */
1076 word = (map[0] << 8) + map[1];
1077 if (map[0] == 0x78 && !(word % 31))
1078 return 1;
1079 else
1080 return 0;
1081}
1082
72518e9c 1083unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1084{
ad1ed5ee 1085 unsigned shift;
93821bd9 1086 unsigned char c;
93821bd9 1087 unsigned long size;
ad1ed5ee
JH
1088 unsigned long used = 0;
1089
1090 c = buf[used++];
1091 *type = (c >> 4) & 7;
1092 size = c & 15;
1093 shift = 4;
1094 while (c & 0x80) {
1095 if (len <= used)
1096 return 0;
1097 if (sizeof(long) * 8 <= shift)
1098 return 0;
1099 c = buf[used++];
1100 size += (c & 0x7f) << shift;
1101 shift += 7;
1102 }
1103 *sizep = size;
1104 return used;
1105}
1106
1107static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1108{
1109 unsigned long size, used;
1110 static const char valid_loose_object_type[8] = {
1111 0, /* OBJ_EXT */
1112 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1113 0, /* "delta" and others are invalid in a loose object */
93821bd9 1114 };
ad1ed5ee 1115 enum object_type type;
93821bd9 1116
c4483576
LT
1117 /* Get the data stream */
1118 memset(stream, 0, sizeof(*stream));
1119 stream->next_in = map;
1120 stream->avail_in = mapsize;
1121 stream->next_out = buffer;
93821bd9
LT
1122 stream->avail_out = bufsiz;
1123
bb6b8e4f 1124 if (legacy_loose_object(map)) {
93821bd9
LT
1125 inflateInit(stream);
1126 return inflate(stream, 0);
1127 }
1128
726f852b
NP
1129
1130 /*
1131 * There used to be a second loose object header format which
1132 * was meant to mimic the in-pack format, allowing for direct
1133 * copy of the object data. This format turned up not to be
1134 * really worth it and we don't write it any longer. But we
1135 * can still read it.
1136 */
ad1ed5ee
JH
1137 used = unpack_object_header_gently(map, mapsize, &type, &size);
1138 if (!used || !valid_loose_object_type[type])
93821bd9 1139 return -1;
ad1ed5ee
JH
1140 map += used;
1141 mapsize -= used;
93821bd9
LT
1142
1143 /* Set up the stream for the rest.. */
1144 stream->next_in = map;
1145 stream->avail_in = mapsize;
c4483576 1146 inflateInit(stream);
93821bd9
LT
1147
1148 /* And generate the fake traditional header */
ad1ed5ee 1149 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1150 typename(type), size);
93821bd9 1151 return 0;
c4483576
LT
1152}
1153
7efbff75 1154static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1155{
1156 int bytes = strlen(buffer) + 1;
d565b341 1157 unsigned char *buf = xmalloc(1+size);
93821bd9 1158 unsigned long n;
7efbff75 1159 int status = Z_OK;
5180cacc 1160
93821bd9
LT
1161 n = stream->total_out - bytes;
1162 if (n > size)
1163 n = size;
1164 memcpy(buf, (char *) buffer + bytes, n);
1165 bytes = n;
456cdf6e
LT
1166 if (bytes <= size) {
1167 /*
1168 * The above condition must be (bytes <= size), not
1169 * (bytes < size). In other words, even though we
1170 * expect no more output and set avail_out to zer0,
1171 * the input zlib stream may have bytes that express
1172 * "this concludes the stream", and we *do* want to
1173 * eat that input.
1174 *
1175 * Otherwise we would not be able to test that we
1176 * consumed all the input to reach the expected size;
1177 * we also want to check that zlib tells us that all
1178 * went well with status == Z_STREAM_END at the end.
1179 */
5180cacc
LT
1180 stream->next_out = buf + bytes;
1181 stream->avail_out = size - bytes;
7efbff75
JH
1182 while (status == Z_OK)
1183 status = inflate(stream, Z_FINISH);
5180cacc
LT
1184 }
1185 buf[size] = 0;
456cdf6e 1186 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1187 inflateEnd(stream);
1188 return buf;
1189 }
1190
1191 if (status < 0)
1192 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1193 else if (stream->avail_in)
1194 error("garbage at end of loose object '%s'",
1195 sha1_to_hex(sha1));
1196 free(buf);
1197 return NULL;
5180cacc
LT
1198}
1199
1200/*
1201 * We used to just use "sscanf()", but that's actually way
1202 * too permissive for what we want to check. So do an anal
1203 * object header parse by hand.
1204 */
21666f1a 1205static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1206{
21666f1a 1207 char type[10];
5180cacc
LT
1208 int i;
1209 unsigned long size;
1210
1211 /*
a6080a0a 1212 * The type can be at most ten bytes (including the
5180cacc 1213 * terminating '\0' that we add), and is followed by
21666f1a 1214 * a space.
5180cacc 1215 */
21666f1a 1216 i = 0;
5180cacc
LT
1217 for (;;) {
1218 char c = *hdr++;
1219 if (c == ' ')
1220 break;
21666f1a
NP
1221 type[i++] = c;
1222 if (i >= sizeof(type))
5180cacc 1223 return -1;
5180cacc 1224 }
21666f1a 1225 type[i] = 0;
5180cacc
LT
1226
1227 /*
1228 * The length must follow immediately, and be in canonical
1229 * decimal format (ie "010" is not valid).
1230 */
1231 size = *hdr++ - '0';
1232 if (size > 9)
1233 return -1;
1234 if (size) {
1235 for (;;) {
1236 unsigned long c = *hdr - '0';
1237 if (c > 9)
1238 break;
1239 hdr++;
1240 size = size * 10 + c;
1241 }
1242 }
1243 *sizep = size;
1244
1245 /*
1246 * The length must be followed by a zero byte
1247 */
21666f1a 1248 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1249}
1250
7efbff75 1251static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1252{
5180cacc 1253 int ret;
0fcfd160 1254 z_stream stream;
5180cacc 1255 char hdr[8192];
0fcfd160 1256
5180cacc 1257 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1258 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1259 return NULL;
1260
7efbff75 1261 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1262}
1263
54dab52a
NP
1264unsigned long get_size_from_delta(struct packed_git *p,
1265 struct pack_window **w_curs,
1266 off_t curpos)
1267{
1268 const unsigned char *data;
1269 unsigned char delta_head[20], *in;
1270 z_stream stream;
1271 int st;
1272
1273 memset(&stream, 0, sizeof(stream));
1274 stream.next_out = delta_head;
1275 stream.avail_out = sizeof(delta_head);
1276
1277 inflateInit(&stream);
1278 do {
1279 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1280 stream.next_in = in;
1281 st = inflate(&stream, Z_FINISH);
1282 curpos += stream.next_in - in;
1283 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1284 stream.total_out < sizeof(delta_head));
1285 inflateEnd(&stream);
1286 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1287 die("delta data unpack-initial failed");
1288
1289 /* Examine the initial part of the delta to figure out
1290 * the result size.
1291 */
1292 data = delta_head;
1293
1294 /* ignore base size */
1295 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1296
1297 /* Read the result size */
1298 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1299}
1300
c4001d92 1301static off_t get_delta_base(struct packed_git *p,
03e79c88 1302 struct pack_window **w_curs,
c4001d92 1303 off_t *curpos,
21666f1a 1304 enum object_type type,
c4001d92 1305 off_t delta_obj_offset)
eb32d236 1306{
2b87c45b 1307 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1308 off_t base_offset;
eb32d236 1309
8d8a4ea5
SP
1310 /* use_pack() assured us we have [base_info, base_info + 20)
1311 * as a range that we can look at without walking off the
1312 * end of the mapped window. Its actually the hash size
1313 * that is assured. An OFS_DELTA longer than the hash size
1314 * is stupid, as then a REF_DELTA would be smaller to store.
1315 */
21666f1a 1316 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1317 unsigned used = 0;
1318 unsigned char c = base_info[used++];
1319 base_offset = c & 127;
1320 while (c & 128) {
1321 base_offset += 1;
8723f216 1322 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1323 return 0; /* overflow */
eb32d236
NP
1324 c = base_info[used++];
1325 base_offset = (base_offset << 7) + (c & 127);
1326 }
1327 base_offset = delta_obj_offset - base_offset;
1328 if (base_offset >= delta_obj_offset)
8eca0b47 1329 return 0; /* out of bound */
2b87c45b 1330 *curpos += used;
21666f1a 1331 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1332 /* The base entry _must_ be in the same pack */
1333 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1334 *curpos += 20;
eb32d236
NP
1335 } else
1336 die("I am totally screwed");
2b87c45b 1337 return base_offset;
eb32d236
NP
1338}
1339
f3bf9224 1340/* forward declaration for a mutually recursive function */
c4001d92 1341static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1342 unsigned long *sizep);
f3bf9224 1343
43057304 1344static int packed_delta_info(struct packed_git *p,
03e79c88 1345 struct pack_window **w_curs,
c4001d92 1346 off_t curpos,
21666f1a 1347 enum object_type type,
c4001d92 1348 off_t obj_offset,
43057304 1349 unsigned long *sizep)
5db47c2b 1350{
c4001d92 1351 off_t base_offset;
f3bf9224 1352
21666f1a
NP
1353 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1354 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1355
c62266f3
JH
1356 /* We choose to only get the type of the base object and
1357 * ignore potentially corrupt pack file that expects the delta
1358 * based on a base with a wrong size. This saves tons of
1359 * inflate() calls.
1360 */
54dab52a
NP
1361 if (sizep)
1362 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1363
1364 return type;
5db47c2b
JH
1365}
1366
2b87c45b
NP
1367static int unpack_object_header(struct packed_git *p,
1368 struct pack_window **w_curs,
c4001d92 1369 off_t *curpos,
2b87c45b 1370 unsigned long *sizep)
a733cb60 1371{
03e79c88
SP
1372 unsigned char *base;
1373 unsigned int left;
ad1ed5ee 1374 unsigned long used;
2b87c45b 1375 enum object_type type;
a733cb60 1376
8d8a4ea5
SP
1377 /* use_pack() assures us we have [base, base + 20) available
1378 * as a range that we can look at at. (Its actually the hash
3dff5379 1379 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1380 * the maximum deflated object size is 2^137, which is just
1381 * insane, so we know won't exceed what we have been given.
1382 */
2b87c45b
NP
1383 base = use_pack(p, w_curs, *curpos, &left);
1384 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1385 if (!used)
1386 die("object offset outside of pack file");
2b87c45b 1387 *curpos += used;
ad1ed5ee 1388
2b87c45b 1389 return type;
a733cb60
LT
1390}
1391
21666f1a 1392const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1393 off_t obj_offset,
21666f1a
NP
1394 unsigned long *size,
1395 unsigned long *store_size,
1396 unsigned int *delta_chain_length,
1397 unsigned char *base_sha1)
ad8c80a5 1398{
03e79c88 1399 struct pack_window *w_curs = NULL;
c4001d92
SP
1400 off_t curpos;
1401 unsigned long dummy;
43057304 1402 unsigned char *next_sha1;
21666f1a 1403 enum object_type type;
70f5d5d3 1404 struct revindex_entry *revidx;
ad8c80a5 1405
43057304 1406 *delta_chain_length = 0;
2b87c45b 1407 curpos = obj_offset;
21666f1a 1408 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304 1409
70f5d5d3
NP
1410 revidx = find_pack_revindex(p, obj_offset);
1411 *store_size = revidx[1].offset - obj_offset;
1412
43057304 1413 for (;;) {
21666f1a 1414 switch (type) {
43057304 1415 default:
08a19d87 1416 die("pack %s contains unknown object type %d",
21666f1a 1417 p->pack_name, type);
43057304
NP
1418 case OBJ_COMMIT:
1419 case OBJ_TREE:
1420 case OBJ_BLOB:
1421 case OBJ_TAG:
03e79c88 1422 unuse_pack(&w_curs);
21666f1a 1423 return typename(type);
eb32d236 1424 case OBJ_OFS_DELTA:
21666f1a 1425 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
8eca0b47
NP
1426 if (!obj_offset)
1427 die("pack %s contains bad delta base reference of type %s",
1428 p->pack_name, typename(type));
eb32d236 1429 if (*delta_chain_length == 0) {
70f5d5d3
NP
1430 revidx = find_pack_revindex(p, obj_offset);
1431 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
eb32d236
NP
1432 }
1433 break;
1434 case OBJ_REF_DELTA:
2b87c45b 1435 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1436 if (*delta_chain_length == 0)
1437 hashcpy(base_sha1, next_sha1);
2b87c45b 1438 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1439 break;
1440 }
43057304 1441 (*delta_chain_length)++;
2b87c45b 1442 curpos = obj_offset;
21666f1a 1443 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1444 }
ad8c80a5
JH
1445}
1446
c4001d92 1447static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1448 unsigned long *sizep)
1f688557 1449{
03e79c88 1450 struct pack_window *w_curs = NULL;
c4001d92
SP
1451 unsigned long size;
1452 off_t curpos = obj_offset;
21666f1a 1453 enum object_type type;
5db47c2b 1454
21666f1a 1455 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1456
21666f1a 1457 switch (type) {
eb32d236
NP
1458 case OBJ_OFS_DELTA:
1459 case OBJ_REF_DELTA:
21666f1a
NP
1460 type = packed_delta_info(p, &w_curs, curpos,
1461 type, obj_offset, sizep);
2b87c45b 1462 break;
a733cb60 1463 case OBJ_COMMIT:
a733cb60 1464 case OBJ_TREE:
a733cb60 1465 case OBJ_BLOB:
a733cb60 1466 case OBJ_TAG:
2b87c45b
NP
1467 if (sizep)
1468 *sizep = size;
a69d0943 1469 break;
1f688557 1470 default:
08a19d87 1471 die("pack %s contains unknown object type %d",
21666f1a 1472 p->pack_name, type);
1f688557 1473 }
2b87c45b 1474 unuse_pack(&w_curs);
21666f1a 1475 return type;
1f688557
JH
1476}
1477
eb950c19 1478static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1479 struct pack_window **w_curs,
c4001d92 1480 off_t curpos,
eb950c19 1481 unsigned long size)
de530aaa
SP
1482{
1483 int st;
1484 z_stream stream;
079afb18 1485 unsigned char *buffer, *in;
de530aaa
SP
1486
1487 buffer = xmalloc(size + 1);
1488 buffer[size] = 0;
1489 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1490 stream.next_out = buffer;
1491 stream.avail_out = size;
1492
1493 inflateInit(&stream);
079afb18 1494 do {
2b87c45b 1495 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1496 stream.next_in = in;
1497 st = inflate(&stream, Z_FINISH);
2b87c45b 1498 curpos += stream.next_in - in;
079afb18 1499 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1500 inflateEnd(&stream);
1501 if ((st != Z_STREAM_END) || stream.total_out != size) {
1502 free(buffer);
1503 return NULL;
1504 }
1505
1506 return buffer;
1507}
1508
e5e01619
LT
1509#define MAX_DELTA_CACHE (256)
1510
18bdec11 1511static size_t delta_base_cached;
5e08ecbf
NP
1512
1513static struct delta_base_cache_lru_list {
1514 struct delta_base_cache_lru_list *prev;
1515 struct delta_base_cache_lru_list *next;
1516} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1517
e5e01619 1518static struct delta_base_cache_entry {
5e08ecbf
NP
1519 struct delta_base_cache_lru_list lru;
1520 void *data;
e5e01619
LT
1521 struct packed_git *p;
1522 off_t base_offset;
1523 unsigned long size;
e5e01619
LT
1524 enum object_type type;
1525} delta_base_cache[MAX_DELTA_CACHE];
1526
1527static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1528{
1529 unsigned long hash;
1530
1531 hash = (unsigned long)p + (unsigned long)base_offset;
1532 hash += (hash >> 8) + (hash >> 16);
3358004a 1533 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1534}
1535
62f255ad 1536static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1537 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1538{
e5e01619
LT
1539 void *ret;
1540 unsigned long hash = pack_entry_hash(p, base_offset);
1541 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1542
1543 ret = ent->data;
1544 if (ret && ent->p == p && ent->base_offset == base_offset)
1545 goto found_cache_entry;
62f255ad 1546 return unpack_entry(p, base_offset, type, base_size);
e5e01619
LT
1547
1548found_cache_entry:
18bdec11 1549 if (!keep_cache) {
a0cba108 1550 ent->data = NULL;
5e08ecbf
NP
1551 ent->lru.next->prev = ent->lru.prev;
1552 ent->lru.prev->next = ent->lru.next;
18bdec11 1553 delta_base_cached -= ent->size;
182af834
PH
1554 } else {
1555 ret = xmemdupz(ent->data, ent->size);
a0cba108 1556 }
e5e01619
LT
1557 *type = ent->type;
1558 *base_size = ent->size;
1559 return ret;
62f255ad
LT
1560}
1561
18bdec11
SP
1562static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1563{
1564 if (ent->data) {
1565 free(ent->data);
1566 ent->data = NULL;
5e08ecbf
NP
1567 ent->lru.next->prev = ent->lru.prev;
1568 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1569 delta_base_cached -= ent->size;
1570 }
1571}
1572
62f255ad
LT
1573static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1574 void *base, unsigned long base_size, enum object_type type)
1575{
5e08ecbf 1576 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1577 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1578 struct delta_base_cache_lru_list *lru;
e5e01619 1579
18bdec11
SP
1580 release_delta_base_cache(ent);
1581 delta_base_cached += base_size;
5e08ecbf
NP
1582
1583 for (lru = delta_base_cache_lru.next;
1584 delta_base_cached > delta_base_cache_limit
1585 && lru != &delta_base_cache_lru;
1586 lru = lru->next) {
1587 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1588 if (f->type == OBJ_BLOB)
1589 release_delta_base_cache(f);
1590 }
5e08ecbf
NP
1591 for (lru = delta_base_cache_lru.next;
1592 delta_base_cached > delta_base_cache_limit
1593 && lru != &delta_base_cache_lru;
1594 lru = lru->next) {
1595 struct delta_base_cache_entry *f = (void *)lru;
1596 release_delta_base_cache(f);
1597 }
18bdec11 1598
e5e01619
LT
1599 ent->p = p;
1600 ent->base_offset = base_offset;
1601 ent->type = type;
1602 ent->data = base;
1603 ent->size = base_size;
5e08ecbf
NP
1604 ent->lru.next = &delta_base_cache_lru;
1605 ent->lru.prev = delta_base_cache_lru.prev;
1606 delta_base_cache_lru.prev->next = &ent->lru;
1607 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1608}
1609
eb950c19 1610static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1611 struct pack_window **w_curs,
c4001d92 1612 off_t curpos,
1f688557 1613 unsigned long delta_size,
c4001d92 1614 off_t obj_offset,
21666f1a 1615 enum object_type *type,
eb950c19 1616 unsigned long *sizep)
1f688557 1617{
7c3e8be3 1618 void *delta_data, *result, *base;
c4001d92
SP
1619 unsigned long base_size;
1620 off_t base_offset;
43057304 1621
21666f1a 1622 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
8eca0b47
NP
1623 if (!base_offset) {
1624 error("failed to validate delta base reference "
1625 "at offset %"PRIuMAX" from %s",
1626 (uintmax_t)curpos, p->pack_name);
1627 return NULL;
1628 }
a0cba108 1629 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
8eca0b47
NP
1630 if (!base) {
1631 /*
1632 * We're probably in deep shit, but let's try to fetch
1633 * the required base anyway from another pack or loose.
1634 * This is costly but should happen only in the presence
1635 * of a corrupted pack, and is better than failing outright.
1636 */
1637 struct revindex_entry *revidx = find_pack_revindex(p, base_offset);
1638 const unsigned char *base_sha1 =
1639 nth_packed_object_sha1(p, revidx->nr);
1640 error("failed to read delta base object %s"
1641 " at offset %"PRIuMAX" from %s",
1642 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1643 p->pack_name);
1644 mark_bad_packed_object(p, base_sha1);
1645 base = read_sha1_file(base_sha1, type, &base_size);
1646 if (!base)
1647 return NULL;
1648 }
67686d95 1649
2b87c45b 1650 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
8eca0b47
NP
1651 if (!delta_data) {
1652 error("failed to unpack compressed delta "
1653 "at offset %"PRIuMAX" from %s",
1654 (uintmax_t)curpos, p->pack_name);
1655 free(base);
1656 return NULL;
1657 }
1f688557
JH
1658 result = patch_delta(base, base_size,
1659 delta_data, delta_size,
21666f1a 1660 sizep);
1f688557
JH
1661 if (!result)
1662 die("failed to apply delta");
1663 free(delta_data);
62f255ad 1664 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1665 return result;
1666}
1667
c4001d92 1668void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1669 enum object_type *type, unsigned long *sizep)
1f688557 1670{
03e79c88 1671 struct pack_window *w_curs = NULL;
c4001d92 1672 off_t curpos = obj_offset;
21666f1a 1673 void *data;
1f688557 1674
21666f1a
NP
1675 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1676 switch (*type) {
eb32d236
NP
1677 case OBJ_OFS_DELTA:
1678 case OBJ_REF_DELTA:
21666f1a
NP
1679 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1680 obj_offset, type, sizep);
4d703a1a 1681 break;
a733cb60 1682 case OBJ_COMMIT:
a733cb60 1683 case OBJ_TREE:
a733cb60 1684 case OBJ_BLOB:
a733cb60 1685 case OBJ_TAG:
21666f1a 1686 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1687 break;
1f688557 1688 default:
8eca0b47
NP
1689 data = NULL;
1690 error("unknown object type %i at offset %"PRIuMAX" in %s",
1691 *type, (uintmax_t)obj_offset, p->pack_name);
1f688557 1692 }
03e79c88 1693 unuse_pack(&w_curs);
21666f1a 1694 return data;
1f688557
JH
1695}
1696
d079837e 1697const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1698 uint32_t n)
9a217f2a 1699{
42873078 1700 const unsigned char *index = p->index_data;
d079837e
SP
1701 if (!index) {
1702 if (open_pack_index(p))
1703 return NULL;
1704 index = p->index_data;
1705 }
57059091 1706 if (n >= p->num_objects)
d72308e0 1707 return NULL;
74e34e1f
NP
1708 index += 4 * 256;
1709 if (p->index_version == 1) {
1710 return index + 24 * n + 4;
1711 } else {
1712 index += 8;
1713 return index + 20 * n;
1714 }
1715}
1716
99093238 1717off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
1718{
1719 const unsigned char *index = p->index_data;
1720 index += 4 * 256;
1721 if (p->index_version == 1) {
1722 return ntohl(*((uint32_t *)(index + 24 * n)));
1723 } else {
1724 uint32_t off;
1725 index += 8 + p->num_objects * (20 + 4);
1726 off = ntohl(*((uint32_t *)(index + 4 * n)));
1727 if (!(off & 0x80000000))
1728 return off;
1729 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1730 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1731 ntohl(*((uint32_t *)(index + 4)));
1732 }
9a217f2a
JH
1733}
1734
c4001d92 1735off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1736 struct packed_git *p)
1f688557 1737{
42873078 1738 const uint32_t *level1_ofs = p->index_data;
42873078 1739 const unsigned char *index = p->index_data;
628522ec
JH
1740 unsigned hi, lo, stride;
1741 static int use_lookup = -1;
1742 static int debug_lookup = -1;
1743
1744 if (debug_lookup < 0)
1745 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1746
d079837e
SP
1747 if (!index) {
1748 if (open_pack_index(p))
1749 return 0;
1750 level1_ofs = p->index_data;
1751 index = p->index_data;
1752 }
74e34e1f
NP
1753 if (p->index_version > 1) {
1754 level1_ofs += 2;
1755 index += 8;
1756 }
42873078 1757 index += 4 * 256;
74e34e1f
NP
1758 hi = ntohl(level1_ofs[*sha1]);
1759 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
1760 if (p->index_version > 1) {
1761 stride = 20;
1762 } else {
1763 stride = 24;
1764 index += 4;
1765 }
1766
1767 if (debug_lookup)
1768 printf("%02x%02x%02x... lo %u hi %u nr %u\n",
1769 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1770
1771 if (use_lookup < 0)
1772 use_lookup = !!getenv("GIT_USE_LOOKUP");
1773 if (use_lookup) {
1774 int pos = sha1_entry_pos(index, stride, 0,
1775 lo, hi, p->num_objects, sha1);
1776 if (pos < 0)
1777 return 0;
1778 return nth_packed_object_offset(p, pos);
1779 }
1f688557
JH
1780
1781 do {
74e34e1f 1782 unsigned mi = (lo + hi) / 2;
628522ec
JH
1783 int cmp = hashcmp(index + mi * stride, sha1);
1784
1785 if (debug_lookup)
1786 printf("lo %u hi %u rg %u mi %u\n",
1787 lo, hi, hi - lo, mi);
43057304 1788 if (!cmp)
74e34e1f 1789 return nth_packed_object_offset(p, mi);
1f688557
JH
1790 if (cmp > 0)
1791 hi = mi;
1792 else
1793 lo = mi+1;
1794 } while (lo < hi);
1795 return 0;
1796}
1797
000dfd3f 1798int matches_pack_name(struct packed_git *p, const char *name)
d4ff6d92
SP
1799{
1800 const char *last_c, *c;
1801
000dfd3f
JH
1802 if (!strcmp(p->pack_name, name))
1803 return 1;
d4ff6d92
SP
1804
1805 for (c = p->pack_name, last_c = c; *c;)
1806 if (*c == '/')
1807 last_c = ++c;
1808 else
1809 ++c;
000dfd3f
JH
1810 if (!strcmp(last_c, name))
1811 return 1;
d4ff6d92 1812
000dfd3f 1813 return 0;
d4ff6d92
SP
1814}
1815
106d710b 1816static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1817{
f7c22cc6 1818 static struct packed_git *last_found = (void *)1;
1f688557 1819 struct packed_git *p;
c4001d92 1820 off_t offset;
43057304 1821
1f688557 1822 prepare_packed_git();
f7c22cc6
NP
1823 if (!packed_git)
1824 return 0;
1825 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1826
f7c22cc6 1827 do {
106d710b
JH
1828 if (ignore_packed) {
1829 const char **ig;
1830 for (ig = ignore_packed; *ig; ig++)
000dfd3f 1831 if (matches_pack_name(p, *ig))
106d710b
JH
1832 break;
1833 if (*ig)
f7c22cc6 1834 goto next;
106d710b 1835 }
f7c22cc6 1836
8eca0b47
NP
1837 if (p->num_bad_objects) {
1838 unsigned i;
1839 for (i = 0; i < p->num_bad_objects; i++)
1840 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1841 goto next;
1842 }
1843
43057304
NP
1844 offset = find_pack_entry_one(sha1, p);
1845 if (offset) {
c715f783
SP
1846 /*
1847 * We are about to tell the caller where they can
1848 * locate the requested object. We better make
1849 * sure the packfile is still here and can be
1850 * accessed before supplying that answer, as
1851 * it may have been deleted since the index
1852 * was loaded!
1853 */
1854 if (p->pack_fd == -1 && open_packed_git(p)) {
1855 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1856 goto next;
c715f783 1857 }
43057304
NP
1858 e->offset = offset;
1859 e->p = p;
1860 hashcpy(e->sha1, sha1);
f7c22cc6 1861 last_found = p;
1f688557 1862 return 1;
43057304 1863 }
f7c22cc6
NP
1864
1865 next:
1866 if (p == last_found)
1867 p = packed_git;
1868 else
1869 p = p->next;
1870 if (p == last_found)
1871 p = p->next;
1872 } while (p);
1f688557
JH
1873 return 0;
1874}
1875
a6080a0a 1876struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1877 struct packed_git *packs)
1878{
1879 struct packed_git *p;
bf592c50
DB
1880
1881 for (p = packs; p; p = p->next) {
43057304 1882 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1883 return p;
1884 }
1885 return NULL;
21666f1a 1886
bf592c50
DB
1887}
1888
21666f1a 1889static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1890{
36e4d74a 1891 int status;
65c2e0c3
JH
1892 unsigned long mapsize, size;
1893 void *map;
1894 z_stream stream;
d65a16f6 1895 char hdr[32];
65c2e0c3 1896
bb6b8e4f 1897 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1898 if (!map)
1899 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1900 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1901 status = error("unable to unpack %s header",
1902 sha1_to_hex(sha1));
21666f1a 1903 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1904 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1905 else if (sizep)
1906 *sizep = size;
65c2e0c3
JH
1907 inflateEnd(&stream);
1908 munmap(map, mapsize);
1909 return status;
1910}
1911
21666f1a 1912int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1913{
f0df4ed5
JS
1914 struct pack_entry e;
1915
1916 if (!find_pack_entry(sha1, &e, NULL)) {
1917 reprepare_packed_git();
1918 if (!find_pack_entry(sha1, &e, NULL))
21666f1a 1919 return sha1_loose_object_info(sha1, sizep);
f0df4ed5 1920 }
21666f1a 1921 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1922}
1923
21666f1a
NP
1924static void *read_packed_sha1(const unsigned char *sha1,
1925 enum object_type *type, unsigned long *size)
1f688557
JH
1926{
1927 struct pack_entry e;
8eca0b47 1928 void *data;
1f688557 1929
8276c007 1930 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1931 return NULL;
8eca0b47
NP
1932 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1933 if (!data) {
1934 /*
1935 * We're probably in deep shit, but let's try to fetch
1936 * the required object anyway from another pack or loose.
1937 * This should happen only in the presence of a corrupted
1938 * pack, and is better than failing outright.
1939 */
1940 error("failed to read object %s at offset %"PRIuMAX" from %s",
1941 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1942 mark_bad_packed_object(e.p, sha1);
1943 data = read_sha1_file(sha1, type, size);
1944 }
1945 return data;
1f688557
JH
1946}
1947
d66b37bb
JH
1948/*
1949 * This is meant to hold a *small* number of objects that you would
1950 * want read_sha1_file() to be able to return, but yet you do not want
1951 * to write them into the object store (e.g. a browse-only
1952 * application).
1953 */
1954static struct cached_object {
1955 unsigned char sha1[20];
21666f1a 1956 enum object_type type;
d66b37bb
JH
1957 void *buf;
1958 unsigned long size;
1959} *cached_objects;
1960static int cached_object_nr, cached_object_alloc;
1961
346245a1
JK
1962static struct cached_object empty_tree = {
1963 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
1964 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
1965 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
1966 OBJ_TREE,
1967 "",
1968 0
1969};
1970
d66b37bb
JH
1971static struct cached_object *find_cached_object(const unsigned char *sha1)
1972{
1973 int i;
1974 struct cached_object *co = cached_objects;
1975
1976 for (i = 0; i < cached_object_nr; i++, co++) {
1977 if (!hashcmp(co->sha1, sha1))
1978 return co;
1979 }
346245a1
JK
1980 if (!hashcmp(sha1, empty_tree.sha1))
1981 return &empty_tree;
d66b37bb
JH
1982 return NULL;
1983}
1984
21666f1a
NP
1985int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1986 unsigned char *sha1)
d66b37bb
JH
1987{
1988 struct cached_object *co;
1989
21666f1a 1990 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
1991 if (has_sha1_file(sha1) || find_cached_object(sha1))
1992 return 0;
1993 if (cached_object_alloc <= cached_object_nr) {
1994 cached_object_alloc = alloc_nr(cached_object_alloc);
1995 cached_objects = xrealloc(cached_objects,
1996 sizeof(*cached_objects) *
1997 cached_object_alloc);
1998 }
1999 co = &cached_objects[cached_object_nr++];
2000 co->size = len;
21666f1a 2001 co->type = type;
efa13f7b
JH
2002 co->buf = xmalloc(len);
2003 memcpy(co->buf, buf, len);
d66b37bb
JH
2004 hashcpy(co->sha1, sha1);
2005 return 0;
2006}
2007
21666f1a
NP
2008void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
2009 unsigned long *size)
0fcfd160
LT
2010{
2011 unsigned long mapsize;
2012 void *map, *buf;
d66b37bb
JH
2013 struct cached_object *co;
2014
2015 co = find_cached_object(sha1);
2016 if (co) {
21666f1a 2017 *type = co->type;
d66b37bb 2018 *size = co->size;
182af834 2019 return xmemdupz(co->buf, co->size);
d66b37bb 2020 }
0fcfd160 2021
8276c007
PE
2022 buf = read_packed_sha1(sha1, type, size);
2023 if (buf)
2024 return buf;
bb6b8e4f 2025 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2026 if (map) {
7efbff75 2027 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2028 munmap(map, mapsize);
2029 return buf;
2030 }
637cdd9d 2031 reprepare_packed_git();
8276c007 2032 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2033}
2034
40469ee9 2035void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2036 const char *required_type_name,
40469ee9
JH
2037 unsigned long *size,
2038 unsigned char *actual_sha1_return)
f4913f91 2039{
21666f1a 2040 enum object_type type, required_type;
f4913f91
JH
2041 void *buffer;
2042 unsigned long isize;
40469ee9 2043 unsigned char actual_sha1[20];
f4913f91 2044
21666f1a 2045 required_type = type_from_string(required_type_name);
e702496e 2046 hashcpy(actual_sha1, sha1);
40469ee9
JH
2047 while (1) {
2048 int ref_length = -1;
2049 const char *ref_type = NULL;
f4913f91 2050
21666f1a 2051 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2052 if (!buffer)
2053 return NULL;
21666f1a 2054 if (type == required_type) {
40469ee9
JH
2055 *size = isize;
2056 if (actual_sha1_return)
e702496e 2057 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2058 return buffer;
2059 }
2060 /* Handle references */
21666f1a 2061 else if (type == OBJ_COMMIT)
40469ee9 2062 ref_type = "tree ";
21666f1a 2063 else if (type == OBJ_TAG)
40469ee9
JH
2064 ref_type = "object ";
2065 else {
2066 free(buffer);
2067 return NULL;
2068 }
2069 ref_length = strlen(ref_type);
f4913f91 2070
50974ec9
MK
2071 if (ref_length + 40 > isize ||
2072 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2073 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2074 free(buffer);
2075 return NULL;
2076 }
1cf58e72 2077 free(buffer);
40469ee9
JH
2078 /* Now we have the ID of the referred-to object in
2079 * actual_sha1. Check again. */
f4913f91 2080 }
f4913f91
JH
2081}
2082
ce9fbf16 2083static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2084 const char *type, unsigned char *sha1,
d65a16f6 2085 char *hdr, int *hdrlen)
d410c0f5
JH
2086{
2087 SHA_CTX c;
2088
2089 /* Generate the header */
d65a16f6 2090 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2091
2092 /* Sha1.. */
2093 SHA1_Init(&c);
2094 SHA1_Update(&c, hdr, *hdrlen);
2095 SHA1_Update(&c, buf, len);
2096 SHA1_Final(sha1, &c);
d410c0f5
JH
2097}
2098
230f1322
LT
2099/*
2100 * Move the just written object into its final resting place
2101 */
839837b9 2102int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2103{
5723fe7e 2104 int ret = link(tmpfile, filename);
7ebb6fca
LT
2105
2106 /*
2107 * Coda hack - coda doesn't like cross-directory links,
2108 * so we fall back to a rename, which will mean that it
2109 * won't be able to check collisions, but that's not a
2110 * big deal.
2111 *
2112 * The same holds for FAT formatted media.
2113 *
2114 * When this succeeds, we just return 0. We have nothing
2115 * left to unlink.
2116 */
2117 if (ret && ret != EEXIST) {
2118 if (!rename(tmpfile, filename))
230f1322 2119 return 0;
9e48b389 2120 ret = errno;
230f1322
LT
2121 }
2122 unlink(tmpfile);
2123 if (ret) {
2124 if (ret != EEXIST) {
916d081b 2125 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2126 }
2127 /* FIXME!!! Collision check here ? */
2128 }
2129
2130 return 0;
2131}
2132
4d548150
LT
2133static int write_buffer(int fd, const void *buf, size_t len)
2134{
d34cf19b 2135 if (write_in_full(fd, buf, len) < 0)
93822c22 2136 return error("file write error (%s)", strerror(errno));
4d548150
LT
2137 return 0;
2138}
2139
ce9fbf16 2140int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2141 unsigned char *sha1)
2142{
d65a16f6 2143 char hdr[32];
abdc3fc8
RS
2144 int hdrlen;
2145 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2146 return 0;
2147}
2148
e9039dd3
LT
2149/* Finalize a file on disk, and close it. */
2150static void close_sha1_file(int fd)
2151{
2152 /* For safe-mode, we could fsync_or_die(fd, "sha1 file") here */
2153 fchmod(fd, 0444);
2154 if (close(fd) != 0)
2155 die("unable to write sha1 file");
2156}
2157
5723fe7e
LT
2158/* Size of directory component, including the ending '/' */
2159static inline int directory_size(const char *filename)
2160{
2161 const char *s = strrchr(filename, '/');
2162 if (!s)
2163 return 0;
2164 return s - filename + 1;
2165}
2166
2167/*
2168 * This creates a temporary file in the same directory as the final
2169 * 'filename'
2170 *
2171 * We want to avoid cross-directory filename renames, because those
2172 * can have problems on various filesystems (FAT, NFS, Coda).
2173 */
2174static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2175{
2176 int fd, dirlen = directory_size(filename);
2177
2178 if (dirlen + 20 > bufsiz) {
2179 errno = ENAMETOOLONG;
2180 return -1;
2181 }
2182 memcpy(buffer, filename, dirlen);
2183 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2184 fd = mkstemp(buffer);
2185 if (fd < 0 && dirlen) {
2186 /* Make sure the directory exists */
6ff6af62 2187 memcpy(buffer, filename, dirlen);
5723fe7e 2188 buffer[dirlen-1] = 0;
3bfaf018 2189 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2190 return -1;
2191
2192 /* Try again */
2193 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2194 fd = mkstemp(buffer);
2195 }
2196 return fd;
2197}
2198
bbac7311
NP
2199static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2200 void *buf, unsigned long len, time_t mtime)
0fcfd160 2201{
bbac7311 2202 int fd, size, ret;
bf0f910d 2203 unsigned char *compressed;
0fcfd160 2204 z_stream stream;
706bc531 2205 char *filename;
aac17941 2206 static char tmpfile[PATH_MAX];
a44c9a5e 2207
972a9155 2208 filename = sha1_file_name(sha1);
5723fe7e 2209 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
aac17941 2210 if (fd < 0) {
916d081b
PB
2211 if (errno == EPERM)
2212 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2213 else
2214 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2215 }
2216
0fcfd160
LT
2217 /* Set it up */
2218 memset(&stream, 0, sizeof(stream));
12f6c308 2219 deflateInit(&stream, zlib_compression_level);
93821bd9 2220 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2221 compressed = xmalloc(size);
0fcfd160
LT
2222
2223 /* Compress it */
0fcfd160
LT
2224 stream.next_out = compressed;
2225 stream.avail_out = size;
a44c9a5e
LT
2226
2227 /* First header.. */
d65a16f6 2228 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2229 stream.avail_in = hdrlen;
726f852b
NP
2230 while (deflate(&stream, 0) == Z_OK)
2231 /* nothing */;
a44c9a5e
LT
2232
2233 /* Then the data itself.. */
2234 stream.next_in = buf;
2235 stream.avail_in = len;
ac54c277
LT
2236 ret = deflate(&stream, Z_FINISH);
2237 if (ret != Z_STREAM_END)
2238 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2239
2240 ret = deflateEnd(&stream);
2241 if (ret != Z_OK)
2242 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2243
0fcfd160
LT
2244 size = stream.total_out;
2245
4d548150
LT
2246 if (write_buffer(fd, compressed, size) < 0)
2247 die("unable to write sha1 file");
e9039dd3 2248 close_sha1_file(fd);
383f85b7 2249 free(compressed);
0fcfd160 2250
bbac7311
NP
2251 if (mtime) {
2252 struct utimbuf utb;
2253 utb.actime = mtime;
2254 utb.modtime = mtime;
2255 if (utime(tmpfile, &utb) < 0)
2256 warning("failed utime() on %s: %s",
2257 tmpfile, strerror(errno));
2258 }
2259
230f1322 2260 return move_temp_to_file(tmpfile, filename);
0fcfd160 2261}
8237b185 2262
bbac7311
NP
2263int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2264{
2265 unsigned char sha1[20];
2266 char hdr[32];
2267 int hdrlen;
2268
2269 /* Normally if we have it in the pack then we do not bother writing
2270 * it out into .git/objects/??/?{38} file.
2271 */
2272 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2273 if (returnsha1)
2274 hashcpy(returnsha1, sha1);
2275 if (has_sha1_file(sha1))
2276 return 0;
2277 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2278}
2279
2280int force_object_loose(const unsigned char *sha1, time_t mtime)
2281{
bbac7311
NP
2282 void *buf;
2283 unsigned long len;
2284 enum object_type type;
2285 char hdr[32];
2286 int hdrlen;
2287
c529d75a 2288 if (has_loose_object(sha1))
bbac7311
NP
2289 return 0;
2290 buf = read_packed_sha1(sha1, &type, &len);
2291 if (!buf)
2292 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2293 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2294 return write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2295}
2296
bf592c50
DB
2297int has_pack_index(const unsigned char *sha1)
2298{
2299 struct stat st;
2300 if (stat(sha1_pack_index_name(sha1), &st))
2301 return 0;
2302 return 1;
2303}
2304
2305int has_pack_file(const unsigned char *sha1)
2306{
2307 struct stat st;
2308 if (stat(sha1_pack_name(sha1), &st))
2309 return 0;
2310 return 1;
2311}
2312
106d710b 2313int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2314{
2315 struct pack_entry e;
106d710b 2316 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2317}
2318
8237b185
DB
2319int has_sha1_file(const unsigned char *sha1)
2320{
1f688557
JH
2321 struct pack_entry e;
2322
106d710b 2323 if (find_pack_entry(sha1, &e, NULL))
1f688557 2324 return 1;
c529d75a 2325 return has_loose_object(sha1);
8237b185 2326}
74400e71 2327
e7332f96
BE
2328int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2329{
fd17f5b5 2330 struct strbuf buf;
e7332f96 2331 int ret;
e7332f96 2332
fd17f5b5
PH
2333 strbuf_init(&buf, 0);
2334 if (strbuf_read(&buf, fd, 4096) < 0) {
2335 strbuf_release(&buf);
024510c8
DB
2336 return -1;
2337 }
e7332f96 2338
024510c8 2339 if (!type)
8e440259 2340 type = blob_type;
024510c8 2341 if (write_object)
fd17f5b5 2342 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
abdc3fc8 2343 else
fd17f5b5
PH
2344 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
2345 strbuf_release(&buf);
2346
024510c8
DB
2347 return ret;
2348}
2349
edaec3fb 2350int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
53bca91a 2351 enum object_type type, const char *path)
74400e71 2352{
dc49cd76 2353 size_t size = xsize_t(st->st_size);
3a55602e 2354 void *buf = NULL;
6c510bee 2355 int ret, re_allocated = 0;
74400e71 2356
74400e71 2357 if (size)
c4712e45 2358 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 2359 close(fd);
74400e71 2360
7672db20 2361 if (!type)
edaec3fb 2362 type = OBJ_BLOB;
6c510bee
LT
2363
2364 /*
2365 * Convert blobs to git internal format
2366 */
d0d8e14d 2367 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
5ecd293d
PH
2368 struct strbuf nbuf;
2369 strbuf_init(&nbuf, 0);
21e5ad50
SP
2370 if (convert_to_git(path, buf, size, &nbuf,
2371 write_object ? safe_crlf : 0)) {
ac78e548 2372 munmap(buf, size);
b315c5c0 2373 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2374 re_allocated = 1;
2375 }
2376 }
2377
7672db20 2378 if (write_object)
edaec3fb 2379 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2380 else
edaec3fb 2381 ret = hash_sha1_file(buf, size, typename(type), sha1);
6c510bee
LT
2382 if (re_allocated) {
2383 free(buf);
2384 return ret;
2385 }
aac17941
LT
2386 if (size)
2387 munmap(buf, size);
2388 return ret;
74400e71 2389}
ec1fcc16
JH
2390
2391int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2392{
2393 int fd;
2394 char *target;
dc49cd76 2395 size_t len;
ec1fcc16
JH
2396
2397 switch (st->st_mode & S_IFMT) {
2398 case S_IFREG:
2399 fd = open(path, O_RDONLY);
2400 if (fd < 0)
2401 return error("open(\"%s\"): %s", path,
2402 strerror(errno));
53bca91a 2403 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2404 return error("%s: failed to insert into database",
2405 path);
2406 break;
2407 case S_IFLNK:
dc49cd76
SP
2408 len = xsize_t(st->st_size);
2409 target = xmalloc(len + 1);
2410 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2411 char *errstr = strerror(errno);
2412 free(target);
2413 return error("readlink(\"%s\"): %s", path,
2414 errstr);
2415 }
abdc3fc8 2416 if (!write_object)
dc49cd76
SP
2417 hash_sha1_file(target, len, blob_type, sha1);
2418 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2419 return error("%s: failed to insert into database",
2420 path);
2421 free(target);
2422 break;
f35a6d3b
LT
2423 case S_IFDIR:
2424 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2425 default:
2426 return error("%s: unsupported file type", path);
2427 }
2428 return 0;
2429}
a69e5429
JH
2430
2431int read_pack_header(int fd, struct pack_header *header)
2432{
c697ad14
HO
2433 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2434 /* "eof before pack header was fully read" */
2435 return PH_ERROR_EOF;
2436
a69e5429
JH
2437 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2438 /* "protocol error (pack signature mismatch detected)" */
2439 return PH_ERROR_PACK_SIGNATURE;
2440 if (!pack_version_ok(header->hdr_version))
2441 /* "protocol error (pack version unsupported)" */
2442 return PH_ERROR_PROTOCOL;
2443 return 0;
2444}