Update draft release notes to 1.6.1
[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
8385abfd
JS
86static inline int offset_1st_component(const char *path)
87{
88 if (has_dos_drive_prefix(path))
89 return 2 + (path[2] == '/');
90 return *path == '/';
91}
92
b2cb9425
JH
93int safe_create_leading_directories(char *path)
94{
8385abfd 95 char *pos = path + offset_1st_component(path);
67d42212
JR
96 struct stat st;
97
b2cb9425
JH
98 while (pos) {
99 pos = strchr(pos, '/');
100 if (!pos)
101 break;
5f0bdf50
JH
102 while (*++pos == '/')
103 ;
104 if (!*pos)
105 break;
106 *--pos = '\0';
67d42212
JR
107 if (!stat(path, &st)) {
108 /* path exists */
109 if (!S_ISDIR(st.st_mode)) {
b2cb9425 110 *pos = '/';
67d42212 111 return -3;
b2cb9425 112 }
457f06d6 113 }
67d42212
JR
114 else if (mkdir(path, 0777)) {
115 *pos = '/';
116 return -1;
117 }
457f06d6
JS
118 else if (adjust_shared_perm(path)) {
119 *pos = '/';
120 return -2;
121 }
b2cb9425
JH
122 *pos++ = '/';
123 }
124 return 0;
125}
723c31fe 126
8e21d63b
JK
127int safe_create_leading_directories_const(const char *path)
128{
129 /* path points to cache entries, so xstrdup before messing with it */
130 char *buf = xstrdup(path);
131 int result = safe_create_leading_directories(buf);
132 free(buf);
133 return result;
134}
135
3bfaf018 136char *sha1_to_hex(const unsigned char *sha1)
0fcfd160 137{
dcb3450f
LT
138 static int bufno;
139 static char hexbuffer[4][50];
0fcfd160 140 static const char hex[] = "0123456789abcdef";
dcb3450f 141 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
142 int i;
143
144 for (i = 0; i < 20; i++) {
145 unsigned int val = *sha1++;
146 *buf++ = hex[val >> 4];
147 *buf++ = hex[val & 0xf];
148 }
1e80e044
JS
149 *buf = '\0';
150
0fcfd160
LT
151 return buffer;
152}
153
ace1534d
JH
154static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
155{
156 int i;
157 for (i = 0; i < 20; i++) {
158 static char hex[] = "0123456789abcdef";
159 unsigned int val = sha1[i];
160 char *pos = pathbuf + i*2 + (i > 0);
161 *pos++ = hex[val >> 4];
162 *pos = hex[val & 0xf];
163 }
164}
165
0fcfd160
LT
166/*
167 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 168 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 169 * filename.
ace1534d
JH
170 *
171 * Also note that this returns the location for creating. Reading
172 * SHA1 file can happen from any alternate directory listed in the
d19938ab 173 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 174 * the primary object database.
0fcfd160
LT
175 */
176char *sha1_file_name(const unsigned char *sha1)
177{
0fcfd160
LT
178 static char *name, *base;
179
180 if (!base) {
d19938ab 181 const char *sha1_file_directory = get_object_directory();
0fcfd160 182 int len = strlen(sha1_file_directory);
812666c8 183 base = xmalloc(len + 60);
0fcfd160
LT
184 memcpy(base, sha1_file_directory, len);
185 memset(base+len, 0, 60);
186 base[len] = '/';
187 base[len+3] = '/';
188 name = base + len + 1;
189 }
ace1534d 190 fill_sha1_path(name, sha1);
0fcfd160
LT
191 return base;
192}
193
633f43e1 194static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 195 char **name, char **base, const char *which)
bf592c50
DB
196{
197 static const char hex[] = "0123456789abcdef";
633f43e1 198 char *buf;
bf592c50
DB
199 int i;
200
633f43e1 201 if (!*base) {
bf592c50
DB
202 const char *sha1_file_directory = get_object_directory();
203 int len = strlen(sha1_file_directory);
633f43e1 204 *base = xmalloc(len + 60);
6eec46bd
JH
205 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
206 sha1_file_directory, which);
633f43e1 207 *name = *base + len + 11;
bf592c50
DB
208 }
209
633f43e1 210 buf = *name;
bf592c50
DB
211
212 for (i = 0; i < 20; i++) {
213 unsigned int val = *sha1++;
214 *buf++ = hex[val >> 4];
215 *buf++ = hex[val & 0xf];
216 }
a6080a0a 217
633f43e1 218 return *base;
bf592c50
DB
219}
220
633f43e1 221char *sha1_pack_name(const unsigned char *sha1)
bf592c50 222{
633f43e1 223 static char *name, *base;
bf592c50 224
6eec46bd 225 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 226}
bf592c50 227
633f43e1
HO
228char *sha1_pack_index_name(const unsigned char *sha1)
229{
230 static char *name, *base;
a6080a0a 231
6eec46bd 232 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
233}
234
d5a63b99
JH
235struct alternate_object_database *alt_odb_list;
236static struct alternate_object_database **alt_odb_tail;
ace1534d 237
c2f493a4
MW
238static void read_info_alternates(const char * alternates, int depth);
239
ddd5d056
JH
240/*
241 * Prepare alternate object database registry.
d5a63b99
JH
242 *
243 * The variable alt_odb_list points at the list of struct
244 * alternate_object_database. The elements on this list come from
245 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
246 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
247 * whose contents is similar to that environment variable but can be
248 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
249 * contains "/the/directory/corresponding/to/.git/objects/...", while
250 * its name points just after the slash at the end of ".git/objects/"
251 * in the example above, and has enough space to hold 40-byte hex
252 * SHA1, an extra slash for the first level indirection, and the
253 * terminating NUL.
ddd5d056 254 */
c2f493a4 255static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 256{
1494e038 257 const char *objdir = get_object_directory();
c2f493a4
MW
258 struct alternate_object_database *ent;
259 struct alternate_object_database *alt;
260 /* 43 = 40-byte + 2 '/' + terminating NUL */
261 int pfxlen = len;
262 int entlen = pfxlen + 43;
ccfd3e99 263 int base_len = -1;
d5a63b99 264
85dadc38 265 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
266 /* Relative alt-odb */
267 if (base_len < 0)
268 base_len = strlen(relative_base) + 1;
269 entlen += base_len;
270 pfxlen += base_len;
271 }
272 ent = xmalloc(sizeof(*ent) + entlen);
273
85dadc38 274 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
275 memcpy(ent->base, relative_base, base_len - 1);
276 ent->base[base_len - 1] = '/';
277 memcpy(ent->base + base_len, entry, len);
278 }
279 else
280 memcpy(ent->base, entry, pfxlen);
281
282 ent->name = ent->base + pfxlen + 1;
283 ent->base[pfxlen + 3] = '/';
284 ent->base[pfxlen] = ent->base[entlen-1] = 0;
285
286 /* Detect cases where alternate disappeared */
90b4a71c 287 if (!is_directory(ent->base)) {
c2f493a4
MW
288 error("object directory %s does not exist; "
289 "check .git/objects/info/alternates.",
290 ent->base);
291 free(ent);
292 return -1;
293 }
294
295 /* Prevent the common mistake of listing the same
296 * thing twice, or object directory itself.
297 */
298 for (alt = alt_odb_list; alt; alt = alt->next) {
299 if (!memcmp(ent->base, alt->base, pfxlen)) {
300 free(ent);
301 return -1;
302 }
303 }
304 if (!memcmp(ent->base, objdir, pfxlen)) {
305 free(ent);
306 return -1;
307 }
308
309 /* add the alternate entry */
310 *alt_odb_tail = ent;
311 alt_odb_tail = &(ent->next);
312 ent->next = NULL;
313
314 /* recursively add alternates */
315 read_info_alternates(ent->base, depth + 1);
316
317 ent->base[pfxlen] = '/';
318
319 return 0;
320}
321
322static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
323 const char *relative_base, int depth)
324{
325 const char *cp, *last;
326
327 if (depth > 5) {
328 error("%s: ignoring alternate object stores, nesting too deep.",
329 relative_base);
330 return;
331 }
332
d5a63b99 333 last = alt;
9577e7e3
JH
334 while (last < ep) {
335 cp = last;
336 if (cp < ep && *cp == '#') {
337 while (cp < ep && *cp != sep)
338 cp++;
339 last = cp + 1;
340 continue;
341 }
c2f493a4
MW
342 while (cp < ep && *cp != sep)
343 cp++;
d5a63b99 344 if (last != cp) {
85dadc38 345 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
346 error("%s: ignoring relative alternate object store %s",
347 relative_base, last);
348 } else {
349 link_alt_odb_entry(last, cp - last,
350 relative_base, depth);
1494e038 351 }
d5a63b99 352 }
9577e7e3 353 while (cp < ep && *cp == sep)
d5a63b99
JH
354 cp++;
355 last = cp;
9577e7e3 356 }
d5a63b99
JH
357}
358
c2f493a4 359static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 360{
9577e7e3 361 char *map;
dc49cd76 362 size_t mapsz;
d5a63b99 363 struct stat st;
9cb18f56
JM
364 const char alt_file_name[] = "info/alternates";
365 /* Given that relative_base is no longer than PATH_MAX,
366 ensure that "path" has enough space to append "/", the
367 file name, "info/alternates", and a trailing NUL. */
368 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 369 int fd;
d5a63b99 370
9cb18f56 371 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
372 fd = open(path, O_RDONLY);
373 if (fd < 0)
374 return;
375 if (fstat(fd, &st) || (st.st_size == 0)) {
376 close(fd);
9a217f2a 377 return;
ace1534d 378 }
dc49cd76
SP
379 mapsz = xsize_t(st.st_size);
380 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 381 close(fd);
d5a63b99 382
dc49cd76 383 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 384
dc49cd76 385 munmap(map, mapsz);
ace1534d
JH
386}
387
bef70b22
DB
388void add_to_alternates_file(const char *reference)
389{
390 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
acd3b9ec 391 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
bef70b22
DB
392 char *alt = mkpath("%s/objects\n", reference);
393 write_or_die(fd, alt, strlen(alt));
394 if (commit_lock_file(lock))
395 die("could not close alternates file");
396 if (alt_odb_tail)
397 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
398}
399
d79796bc
JH
400void foreach_alt_odb(alt_odb_fn fn, void *cb)
401{
402 struct alternate_object_database *ent;
403
404 prepare_alt_odb();
405 for (ent = alt_odb_list; ent; ent = ent->next)
406 if (fn(ent, cb))
407 return;
408}
409
c2f493a4
MW
410void prepare_alt_odb(void)
411{
554fe20d 412 const char *alt;
c2f493a4 413
7dc24aa5
SP
414 if (alt_odb_tail)
415 return;
416
c2f493a4
MW
417 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
418 if (!alt) alt = "";
419
c2f493a4 420 alt_odb_tail = &alt_odb_list;
80ba074f 421 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
422
423 read_info_alternates(get_object_directory(), 0);
424}
425
c529d75a 426static int has_loose_object(const unsigned char *sha1)
ace1534d 427{
ace1534d 428 char *name = sha1_file_name(sha1);
d5a63b99 429 struct alternate_object_database *alt;
ace1534d 430
c529d75a
LT
431 if (!access(name, F_OK))
432 return 1;
9a217f2a 433 prepare_alt_odb();
d5a63b99
JH
434 for (alt = alt_odb_list; alt; alt = alt->next) {
435 name = alt->name;
ace1534d 436 fill_sha1_path(name, sha1);
c529d75a
LT
437 if (!access(alt->base, F_OK))
438 return 1;
ace1534d 439 }
c529d75a 440 return 0;
ace1534d
JH
441}
442
60bb8b14 443static unsigned int pack_used_ctr;
a53128b6
SP
444static unsigned int pack_mmap_calls;
445static unsigned int peak_pack_open_windows;
446static unsigned int pack_open_windows;
447static size_t peak_pack_mapped;
60bb8b14 448static size_t pack_mapped;
9a217f2a 449struct packed_git *packed_git;
1f688557 450
b79d18c9 451void pack_report(void)
a53128b6
SP
452{
453 fprintf(stderr,
e05db0fd
PR
454 "pack_report: getpagesize() = %10" SZ_FMT "\n"
455 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
456 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
457 sz_fmt(getpagesize()),
458 sz_fmt(packed_git_window_size),
459 sz_fmt(packed_git_limit));
a53128b6
SP
460 fprintf(stderr,
461 "pack_report: pack_used_ctr = %10u\n"
462 "pack_report: pack_mmap_calls = %10u\n"
463 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
464 "pack_report: pack_mapped = "
465 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
466 pack_used_ctr,
467 pack_mmap_calls,
468 pack_open_windows, peak_pack_open_windows,
9e42d6a1 469 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
470}
471
42873078 472static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
473{
474 void *idx_map;
42873078 475 struct pack_idx_header *hdr;
dc49cd76 476 size_t idx_size;
74e34e1f 477 uint32_t version, nr, i, *index;
e93ec6f9 478 int fd = open(path, O_RDONLY);
1f688557 479 struct stat st;
42873078 480
1f688557
JH
481 if (fd < 0)
482 return -1;
483 if (fstat(fd, &st)) {
484 close(fd);
485 return -1;
486 }
dc49cd76 487 idx_size = xsize_t(st.st_size);
2d88451b
SP
488 if (idx_size < 4 * 256 + 20 + 20) {
489 close(fd);
490 return error("index file %s is too small", path);
491 }
c4712e45 492 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 493 close(fd);
1f688557 494
42873078
NP
495 hdr = idx_map;
496 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
497 version = ntohl(hdr->idx_version);
498 if (version < 2 || version > 2) {
499 munmap(idx_map, idx_size);
6e1c2344 500 return error("index file %s is version %"PRIu32
74e34e1f
NP
501 " and is not supported by this binary"
502 " (try upgrading GIT to a newer version)",
503 path, version);
504 }
505 } else
506 version = 1;
df1b059d 507
1f688557 508 nr = 0;
42873078 509 index = idx_map;
74e34e1f
NP
510 if (version > 1)
511 index += 2; /* skip index header */
1f688557 512 for (i = 0; i < 256; i++) {
326bf396 513 uint32_t n = ntohl(index[i]);
2d88451b
SP
514 if (n < nr) {
515 munmap(idx_map, idx_size);
df1b059d 516 return error("non-monotonic index %s", path);
2d88451b 517 }
1f688557
JH
518 nr = n;
519 }
520
74e34e1f
NP
521 if (version == 1) {
522 /*
523 * Total size:
524 * - 256 index entries 4 bytes each
525 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
526 * - 20-byte SHA1 of the packfile
527 * - 20-byte SHA1 file checksum
528 */
529 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
530 munmap(idx_map, idx_size);
eef427a0 531 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
532 }
533 } else if (version == 2) {
534 /*
535 * Minimum size:
536 * - 8 bytes of header
537 * - 256 index entries 4 bytes each
538 * - 20-byte sha1 entry * nr
539 * - 4-byte crc entry * nr
540 * - 4-byte offset entry * nr
541 * - 20-byte SHA1 of the packfile
542 * - 20-byte SHA1 file checksum
543 * And after the 4-byte offset table might be a
544 * variable sized table containing 8-byte entries
545 * for offsets larger than 2^31.
546 */
547 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
548 unsigned long max_size = min_size;
549 if (nr)
550 max_size += (nr - 1)*8;
551 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 552 munmap(idx_map, idx_size);
eef427a0 553 return error("wrong index v2 file size in %s", path);
74e34e1f 554 }
7109c889
JH
555 if (idx_size != min_size &&
556 /*
557 * make sure we can deal with large pack offsets.
558 * 31-bit signed offset won't be enough, neither
559 * 32-bit unsigned one will be.
560 */
561 (sizeof(off_t) <= 4)) {
562 munmap(idx_map, idx_size);
563 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 564 }
2d88451b 565 }
1f688557 566
74e34e1f 567 p->index_version = version;
42873078
NP
568 p->index_data = idx_map;
569 p->index_size = idx_size;
57059091 570 p->num_objects = nr;
1f688557
JH
571 return 0;
572}
573
bc8e478a 574int open_pack_index(struct packed_git *p)
d079837e
SP
575{
576 char *idx_name;
577 int ret;
578
579 if (p->index_data)
580 return 0;
581
582 idx_name = xstrdup(p->pack_name);
583 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
584 ret = check_packed_git_idx(idx_name, p);
585 free(idx_name);
586 return ret;
587}
588
11daf39b
SP
589static void scan_windows(struct packed_git *p,
590 struct packed_git **lru_p,
591 struct pack_window **lru_w,
592 struct pack_window **lru_l)
1f688557 593{
11daf39b
SP
594 struct pack_window *w, *w_l;
595
596 for (w_l = NULL, w = p->windows; w; w = w->next) {
597 if (!w->inuse_cnt) {
598 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
599 *lru_p = p;
600 *lru_w = w;
601 *lru_l = w_l;
54044bf8 602 }
54044bf8 603 }
11daf39b 604 w_l = w;
f9253394 605 }
11daf39b
SP
606}
607
d1efefa4 608static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
609{
610 struct packed_git *p, *lru_p = NULL;
611 struct pack_window *lru_w = NULL, *lru_l = NULL;
612
613 if (current)
614 scan_windows(current, &lru_p, &lru_w, &lru_l);
615 for (p = packed_git; p; p = p->next)
616 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
617 if (lru_p) {
618 munmap(lru_w->base, lru_w->len);
619 pack_mapped -= lru_w->len;
620 if (lru_l)
621 lru_l->next = lru_w->next;
622 else {
623 lru_p->windows = lru_w->next;
d1efefa4 624 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
625 close(lru_p->pack_fd);
626 lru_p->pack_fd = -1;
627 }
628 }
629 free(lru_w);
a53128b6 630 pack_open_windows--;
54044bf8
SP
631 return 1;
632 }
633 return 0;
f9253394
JH
634}
635
d1efefa4 636void release_pack_memory(size_t need, int fd)
97bfeb34
SP
637{
638 size_t cur = pack_mapped;
d1efefa4 639 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
640 ; /* nothing */
641}
642
c9ced051
SP
643void close_pack_windows(struct packed_git *p)
644{
645 while (p->windows) {
646 struct pack_window *w = p->windows;
647
648 if (w->inuse_cnt)
649 die("pack '%s' still has open windows to it",
650 p->pack_name);
651 munmap(w->base, w->len);
652 pack_mapped -= w->len;
653 pack_open_windows--;
654 p->windows = w->next;
655 free(w);
656 }
657}
658
03e79c88 659void unuse_pack(struct pack_window **w_cursor)
f9253394 660{
03e79c88
SP
661 struct pack_window *w = *w_cursor;
662 if (w) {
663 w->inuse_cnt--;
664 *w_cursor = NULL;
665 }
1f688557
JH
666}
667
3cf8b462
SP
668/*
669 * Do not call this directly as this leaks p->pack_fd on error return;
670 * call open_packed_git() instead.
671 */
672static int open_packed_git_1(struct packed_git *p)
1f688557 673{
9bc879c1
SP
674 struct stat st;
675 struct pack_header hdr;
676 unsigned char sha1[20];
677 unsigned char *idx_sha1;
2c039da8 678 long fd_flag;
9bc879c1 679
d079837e
SP
680 if (!p->index_data && open_pack_index(p))
681 return error("packfile %s index unavailable", p->pack_name);
682
9bc879c1
SP
683 p->pack_fd = open(p->pack_name, O_RDONLY);
684 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 685 return -1;
9bc879c1
SP
686
687 /* If we created the struct before we had the pack we lack size. */
bf592c50 688 if (!p->pack_size) {
bf592c50 689 if (!S_ISREG(st.st_mode))
072db278 690 return error("packfile %s not a regular file", p->pack_name);
bf592c50 691 p->pack_size = st.st_size;
9bc879c1 692 } else if (p->pack_size != st.st_size)
072db278 693 return error("packfile %s size changed", p->pack_name);
9bc879c1 694
2c039da8
JH
695 /* We leave these file descriptors open with sliding mmap;
696 * there is no point keeping them open across exec(), though.
697 */
698 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
699 if (fd_flag < 0)
072db278 700 return error("cannot determine file descriptor flags");
2c039da8
JH
701 fd_flag |= FD_CLOEXEC;
702 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 703 return error("cannot set FD_CLOEXEC");
2c039da8 704
9bc879c1 705 /* Verify we recognize this pack file format. */
e6e2bd62 706 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 707 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 708 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 709 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 710 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
711 return error("packfile %s is version %"PRIu32" and not"
712 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
713 p->pack_name, ntohl(hdr.hdr_version));
714
715 /* Verify the pack matches its index. */
57059091 716 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
717 return error("packfile %s claims to have %"PRIu32" objects"
718 " while index indicates %"PRIu32" objects",
57059091
NP
719 p->pack_name, ntohl(hdr.hdr_entries),
720 p->num_objects);
9bc879c1 721 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 722 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 723 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 724 return error("packfile %s signature is unavailable", p->pack_name);
42873078 725 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 726 if (hashcmp(sha1, idx_sha1))
072db278
SP
727 return error("packfile %s does not match index", p->pack_name);
728 return 0;
9bc879c1
SP
729}
730
3cf8b462
SP
731static int open_packed_git(struct packed_git *p)
732{
733 if (!open_packed_git_1(p))
734 return 0;
735 if (p->pack_fd != -1) {
736 close(p->pack_fd);
737 p->pack_fd = -1;
738 }
739 return -1;
740}
741
c4001d92 742static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
743{
744 /* We must promise at least 20 bytes (one hash) after the
745 * offset is available from this window, otherwise the offset
746 * is not actually in this window and a different window (which
747 * has that one hash excess) must be used. This is to support
748 * the object header and delta base parsing routines below.
749 */
750 off_t win_off = win->offset;
751 return win_off <= offset
752 && (offset + 20) <= (win_off + win->len);
753}
754
03e79c88
SP
755unsigned char* use_pack(struct packed_git *p,
756 struct pack_window **w_cursor,
c4001d92 757 off_t offset,
03e79c88 758 unsigned int *left)
9bc879c1 759{
60bb8b14 760 struct pack_window *win = *w_cursor;
03e79c88 761
072db278
SP
762 if (p->pack_fd == -1 && open_packed_git(p))
763 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
764
765 /* Since packfiles end in a hash of their content and its
766 * pointless to ask for an offset into the middle of that
767 * hash, and the in_window function above wouldn't match
768 * don't allow an offset too close to the end of the file.
769 */
770 if (offset > (p->pack_size - 20))
771 die("offset beyond end of packfile (truncated pack?)");
772
773 if (!win || !in_window(win, offset)) {
774 if (win)
775 win->inuse_cnt--;
776 for (win = p->windows; win; win = win->next) {
777 if (in_window(win, offset))
778 break;
779 }
780 if (!win) {
78a28df9 781 size_t window_align = packed_git_window_size / 2;
dc49cd76 782 off_t len;
60bb8b14 783 win = xcalloc(1, sizeof(*win));
78a28df9 784 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
785 len = p->pack_size - win->offset;
786 if (len > packed_git_window_size)
787 len = packed_git_window_size;
788 win->len = (size_t)len;
60bb8b14 789 pack_mapped += win->len;
11daf39b 790 while (packed_git_limit < pack_mapped
d1efefa4 791 && unuse_one_window(p, p->pack_fd))
60bb8b14 792 ; /* nothing */
c4712e45 793 win->base = xmmap(NULL, win->len,
60bb8b14
SP
794 PROT_READ, MAP_PRIVATE,
795 p->pack_fd, win->offset);
796 if (win->base == MAP_FAILED)
73b4e4be
SP
797 die("packfile %s cannot be mapped: %s",
798 p->pack_name,
799 strerror(errno));
a53128b6
SP
800 pack_mmap_calls++;
801 pack_open_windows++;
802 if (pack_mapped > peak_pack_mapped)
803 peak_pack_mapped = pack_mapped;
804 if (pack_open_windows > peak_pack_open_windows)
805 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
806 win->next = p->windows;
807 p->windows = win;
808 }
1f688557 809 }
03e79c88
SP
810 if (win != *w_cursor) {
811 win->last_used = pack_used_ctr++;
812 win->inuse_cnt++;
813 *w_cursor = win;
814 }
60bb8b14 815 offset -= win->offset;
03e79c88 816 if (left)
dc49cd76 817 *left = win->len - xsize_t(offset);
03e79c88 818 return win->base + offset;
1f688557
JH
819}
820
27d69a46
NP
821static struct packed_git *alloc_packed_git(int extra)
822{
823 struct packed_git *p = xmalloc(sizeof(*p) + extra);
824 memset(p, 0, sizeof(*p));
825 p->pack_fd = -1;
826 return p;
827}
828
42873078 829struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
830{
831 struct stat st;
27d69a46 832 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 833
42873078
NP
834 /*
835 * Make sure a corresponding .pack file exists and that
836 * the index looks sane.
837 */
838 path_len -= strlen(".idx");
27d69a46
NP
839 if (path_len < 1) {
840 free(p);
1f688557 841 return NULL;
27d69a46 842 }
42873078
NP
843 memcpy(p->pack_name, path, path_len);
844 strcpy(p->pack_name + path_len, ".pack");
d079837e 845 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 846 free(p);
1f688557
JH
847 return NULL;
848 }
42873078 849
1f688557
JH
850 /* ok, it looks sane as far as we can check without
851 * actually mapping the pack file.
852 */
1f688557 853 p->pack_size = st.st_size;
9d835df2 854 p->pack_local = local;
b867092f 855 p->mtime = st.st_mtime;
42873078
NP
856 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
857 hashclr(p->sha1);
1f688557
JH
858 return p;
859}
860
bf592c50 861struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e 862{
79c6dca4 863 const char *idx_path = sha1_pack_index_name(sha1);
42873078 864 const char *path = sha1_pack_name(sha1);
27d69a46 865 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 866
27d69a46
NP
867 strcpy(p->pack_name, path);
868 hashcpy(p->sha1, sha1);
42873078
NP
869 if (check_packed_git_idx(idx_path, p)) {
870 free(p);
bf592c50 871 return NULL;
42873078 872 }
bf592c50 873
bf592c50
DB
874 return p;
875}
876
877void install_packed_git(struct packed_git *pack)
878{
879 pack->next = packed_git;
880 packed_git = pack;
881}
882
9d835df2 883static void prepare_packed_git_one(char *objdir, int local)
1f688557 884{
9cb18f56
JM
885 /* Ensure that this buffer is large enough so that we can
886 append "/pack/" without clobbering the stack even if
887 strlen(objdir) were PATH_MAX. */
888 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
889 int len;
890 DIR *dir;
891 struct dirent *de;
892
893 sprintf(path, "%s/pack", objdir);
894 len = strlen(path);
895 dir = opendir(path);
b5b16990 896 if (!dir) {
26125f6b 897 if (errno != ENOENT)
bd2afde8 898 error("unable to open object pack directory: %s: %s",
26125f6b 899 path, strerror(errno));
1f688557 900 return;
b5b16990 901 }
1f688557
JH
902 path[len++] = '/';
903 while ((de = readdir(dir)) != NULL) {
904 int namelen = strlen(de->d_name);
905 struct packed_git *p;
906
5bb1cda5 907 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
908 continue;
909
9cb18f56
JM
910 if (len + namelen + 1 > sizeof(path))
911 continue;
912
54a15a8d 913 /* Don't reopen a pack we already have. */
1f688557 914 strcpy(path + len, de->d_name);
86f7780c
JK
915 for (p = packed_git; p; p = p->next) {
916 if (!memcmp(path, p->pack_name, len + namelen - 4))
917 break;
918 }
919 if (p)
920 continue;
54a15a8d
SP
921 /* See if it really is a valid .idx file with corresponding
922 * .pack file that we can map.
923 */
9d835df2 924 p = add_packed_git(path, len + namelen, local);
1f688557
JH
925 if (!p)
926 continue;
625e9421 927 install_packed_git(p);
1f688557 928 }
5b35bcd5 929 closedir(dir);
1f688557
JH
930}
931
b867092f
JH
932static int sort_pack(const void *a_, const void *b_)
933{
934 struct packed_git *a = *((struct packed_git **)a_);
935 struct packed_git *b = *((struct packed_git **)b_);
936 int st;
937
938 /*
939 * Local packs tend to contain objects specific to our
940 * variant of the project than remote ones. In addition,
941 * remote ones could be on a network mounted filesystem.
942 * Favor local ones for these reasons.
943 */
944 st = a->pack_local - b->pack_local;
945 if (st)
946 return -st;
947
948 /*
949 * Younger packs tend to contain more recent objects,
950 * and more recent objects tend to get accessed more
951 * often.
952 */
953 if (a->mtime < b->mtime)
954 return 1;
955 else if (a->mtime == b->mtime)
956 return 0;
957 return -1;
958}
959
960static void rearrange_packed_git(void)
961{
962 struct packed_git **ary, *p;
963 int i, n;
964
965 for (n = 0, p = packed_git; p; p = p->next)
966 n++;
967 if (n < 2)
968 return;
969
970 /* prepare an array of packed_git for easier sorting */
971 ary = xcalloc(n, sizeof(struct packed_git *));
972 for (n = 0, p = packed_git; p; p = p->next)
973 ary[n++] = p;
974
975 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
976
977 /* link them back again */
978 for (i = 0; i < n - 1; i++)
979 ary[i]->next = ary[i + 1];
980 ary[n - 1]->next = NULL;
981 packed_git = ary[0];
982
983 free(ary);
984}
985
637cdd9d 986static int prepare_packed_git_run_once = 0;
9a217f2a 987void prepare_packed_git(void)
1f688557 988{
d5a63b99 989 struct alternate_object_database *alt;
1f688557 990
637cdd9d 991 if (prepare_packed_git_run_once)
1f688557 992 return;
9d835df2 993 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 994 prepare_alt_odb();
d5a63b99 995 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 996 alt->name[-1] = 0;
9d835df2 997 prepare_packed_git_one(alt->base, 0);
1494e038 998 alt->name[-1] = '/';
1f688557 999 }
b867092f 1000 rearrange_packed_git();
637cdd9d
JK
1001 prepare_packed_git_run_once = 1;
1002}
1003
fc04c412 1004void reprepare_packed_git(void)
637cdd9d 1005{
4b480c67 1006 discard_revindex();
637cdd9d
JK
1007 prepare_packed_git_run_once = 0;
1008 prepare_packed_git();
1f688557
JH
1009}
1010
8eca0b47
NP
1011static void mark_bad_packed_object(struct packed_git *p,
1012 const unsigned char *sha1)
1013{
1014 unsigned i;
1015 for (i = 0; i < p->num_bad_objects; i++)
1016 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1017 return;
1018 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1019 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1020 p->num_bad_objects++;
1021}
1022
ac939109
NP
1023static int has_packed_and_bad(const unsigned char *sha1)
1024{
1025 struct packed_git *p;
1026 unsigned i;
1027
1028 for (p = packed_git; p; p = p->next)
1029 for (i = 0; i < p->num_bad_objects; i++)
1030 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1031 return 1;
1032 return 0;
1033}
1034
5d6ccf5c 1035int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
1036{
1037 unsigned char real_sha1[20];
7cfb5f36 1038 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 1039 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1040}
1041
44d1c19e
LT
1042static int git_open_noatime(const char *name)
1043{
1044 static int sha1_file_open_flag = O_NOATIME;
1045 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1046
1047 /* Might the failure be due to O_NOATIME? */
1048 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1049 fd = open(name, O_RDONLY);
1050 if (fd >= 0)
1051 sha1_file_open_flag = 0;
1052 }
1053 return fd;
1054}
1055
1056static int open_sha1_file(const unsigned char *sha1)
1057{
1058 int fd;
1059 char *name = sha1_file_name(sha1);
1060 struct alternate_object_database *alt;
1061
1062 fd = git_open_noatime(name);
1063 if (fd >= 0)
1064 return fd;
1065
1066 prepare_alt_odb();
1067 errno = ENOENT;
1068 for (alt = alt_odb_list; alt; alt = alt->next) {
1069 name = alt->name;
1070 fill_sha1_path(name, sha1);
1071 fd = git_open_noatime(alt->base);
1072 if (fd >= 0)
1073 return fd;
1074 }
1075 return -1;
1076}
1077
4175e9e3 1078static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1079{
0fcfd160 1080 void *map;
144bde78 1081 int fd;
ace1534d 1082
44d1c19e
LT
1083 fd = open_sha1_file(sha1);
1084 map = NULL;
1085 if (fd >= 0) {
1086 struct stat st;
0fcfd160 1087
44d1c19e
LT
1088 if (!fstat(fd, &st)) {
1089 *size = xsize_t(st.st_size);
1090 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1091 }
44d1c19e 1092 close(fd);
0fcfd160 1093 }
0fcfd160
LT
1094 return map;
1095}
1096
726f852b 1097static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1098{
1099 unsigned int word;
1100
1101 /*
1102 * Is it a zlib-compressed buffer? If so, the first byte
1103 * must be 0x78 (15-bit window size, deflated), and the
1104 * first 16-bit word is evenly divisible by 31
1105 */
1106 word = (map[0] << 8) + map[1];
1107 if (map[0] == 0x78 && !(word % 31))
1108 return 1;
1109 else
1110 return 0;
1111}
1112
72518e9c 1113unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1114{
ad1ed5ee 1115 unsigned shift;
93821bd9 1116 unsigned char c;
93821bd9 1117 unsigned long size;
ad1ed5ee
JH
1118 unsigned long used = 0;
1119
1120 c = buf[used++];
1121 *type = (c >> 4) & 7;
1122 size = c & 15;
1123 shift = 4;
1124 while (c & 0x80) {
1125 if (len <= used)
1126 return 0;
1127 if (sizeof(long) * 8 <= shift)
1128 return 0;
1129 c = buf[used++];
1130 size += (c & 0x7f) << shift;
1131 shift += 7;
1132 }
1133 *sizep = size;
1134 return used;
1135}
1136
1137static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1138{
1139 unsigned long size, used;
1140 static const char valid_loose_object_type[8] = {
1141 0, /* OBJ_EXT */
1142 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1143 0, /* "delta" and others are invalid in a loose object */
93821bd9 1144 };
ad1ed5ee 1145 enum object_type type;
93821bd9 1146
c4483576
LT
1147 /* Get the data stream */
1148 memset(stream, 0, sizeof(*stream));
1149 stream->next_in = map;
1150 stream->avail_in = mapsize;
1151 stream->next_out = buffer;
93821bd9
LT
1152 stream->avail_out = bufsiz;
1153
bb6b8e4f 1154 if (legacy_loose_object(map)) {
93821bd9
LT
1155 inflateInit(stream);
1156 return inflate(stream, 0);
1157 }
1158
726f852b
NP
1159
1160 /*
1161 * There used to be a second loose object header format which
1162 * was meant to mimic the in-pack format, allowing for direct
1163 * copy of the object data. This format turned up not to be
1164 * really worth it and we don't write it any longer. But we
1165 * can still read it.
1166 */
ad1ed5ee
JH
1167 used = unpack_object_header_gently(map, mapsize, &type, &size);
1168 if (!used || !valid_loose_object_type[type])
93821bd9 1169 return -1;
ad1ed5ee
JH
1170 map += used;
1171 mapsize -= used;
93821bd9
LT
1172
1173 /* Set up the stream for the rest.. */
1174 stream->next_in = map;
1175 stream->avail_in = mapsize;
c4483576 1176 inflateInit(stream);
93821bd9
LT
1177
1178 /* And generate the fake traditional header */
ad1ed5ee 1179 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1180 typename(type), size);
93821bd9 1181 return 0;
c4483576
LT
1182}
1183
7efbff75 1184static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1185{
1186 int bytes = strlen(buffer) + 1;
d565b341 1187 unsigned char *buf = xmalloc(1+size);
93821bd9 1188 unsigned long n;
7efbff75 1189 int status = Z_OK;
5180cacc 1190
93821bd9
LT
1191 n = stream->total_out - bytes;
1192 if (n > size)
1193 n = size;
1194 memcpy(buf, (char *) buffer + bytes, n);
1195 bytes = n;
456cdf6e
LT
1196 if (bytes <= size) {
1197 /*
1198 * The above condition must be (bytes <= size), not
1199 * (bytes < size). In other words, even though we
1200 * expect no more output and set avail_out to zer0,
1201 * the input zlib stream may have bytes that express
1202 * "this concludes the stream", and we *do* want to
1203 * eat that input.
1204 *
1205 * Otherwise we would not be able to test that we
1206 * consumed all the input to reach the expected size;
1207 * we also want to check that zlib tells us that all
1208 * went well with status == Z_STREAM_END at the end.
1209 */
5180cacc
LT
1210 stream->next_out = buf + bytes;
1211 stream->avail_out = size - bytes;
7efbff75
JH
1212 while (status == Z_OK)
1213 status = inflate(stream, Z_FINISH);
5180cacc
LT
1214 }
1215 buf[size] = 0;
456cdf6e 1216 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1217 inflateEnd(stream);
1218 return buf;
1219 }
1220
1221 if (status < 0)
1222 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1223 else if (stream->avail_in)
1224 error("garbage at end of loose object '%s'",
1225 sha1_to_hex(sha1));
1226 free(buf);
1227 return NULL;
5180cacc
LT
1228}
1229
1230/*
1231 * We used to just use "sscanf()", but that's actually way
1232 * too permissive for what we want to check. So do an anal
1233 * object header parse by hand.
1234 */
21666f1a 1235static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1236{
21666f1a 1237 char type[10];
5180cacc
LT
1238 int i;
1239 unsigned long size;
1240
1241 /*
a6080a0a 1242 * The type can be at most ten bytes (including the
5180cacc 1243 * terminating '\0' that we add), and is followed by
21666f1a 1244 * a space.
5180cacc 1245 */
21666f1a 1246 i = 0;
5180cacc
LT
1247 for (;;) {
1248 char c = *hdr++;
1249 if (c == ' ')
1250 break;
21666f1a
NP
1251 type[i++] = c;
1252 if (i >= sizeof(type))
5180cacc 1253 return -1;
5180cacc 1254 }
21666f1a 1255 type[i] = 0;
5180cacc
LT
1256
1257 /*
1258 * The length must follow immediately, and be in canonical
1259 * decimal format (ie "010" is not valid).
1260 */
1261 size = *hdr++ - '0';
1262 if (size > 9)
1263 return -1;
1264 if (size) {
1265 for (;;) {
1266 unsigned long c = *hdr - '0';
1267 if (c > 9)
1268 break;
1269 hdr++;
1270 size = size * 10 + c;
1271 }
1272 }
1273 *sizep = size;
1274
1275 /*
1276 * The length must be followed by a zero byte
1277 */
21666f1a 1278 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1279}
1280
7efbff75 1281static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1282{
5180cacc 1283 int ret;
0fcfd160 1284 z_stream stream;
5180cacc 1285 char hdr[8192];
0fcfd160 1286
5180cacc 1287 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1288 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1289 return NULL;
1290
7efbff75 1291 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1292}
1293
54dab52a
NP
1294unsigned long get_size_from_delta(struct packed_git *p,
1295 struct pack_window **w_curs,
1296 off_t curpos)
1297{
1298 const unsigned char *data;
1299 unsigned char delta_head[20], *in;
1300 z_stream stream;
1301 int st;
1302
1303 memset(&stream, 0, sizeof(stream));
1304 stream.next_out = delta_head;
1305 stream.avail_out = sizeof(delta_head);
1306
1307 inflateInit(&stream);
1308 do {
1309 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1310 stream.next_in = in;
1311 st = inflate(&stream, Z_FINISH);
1312 curpos += stream.next_in - in;
1313 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1314 stream.total_out < sizeof(delta_head));
1315 inflateEnd(&stream);
1316 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1317 die("delta data unpack-initial failed");
1318
1319 /* Examine the initial part of the delta to figure out
1320 * the result size.
1321 */
1322 data = delta_head;
1323
1324 /* ignore base size */
1325 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1326
1327 /* Read the result size */
1328 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1329}
1330
c4001d92 1331static off_t get_delta_base(struct packed_git *p,
03e79c88 1332 struct pack_window **w_curs,
c4001d92 1333 off_t *curpos,
21666f1a 1334 enum object_type type,
c4001d92 1335 off_t delta_obj_offset)
eb32d236 1336{
2b87c45b 1337 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1338 off_t base_offset;
eb32d236 1339
8d8a4ea5
SP
1340 /* use_pack() assured us we have [base_info, base_info + 20)
1341 * as a range that we can look at without walking off the
1342 * end of the mapped window. Its actually the hash size
1343 * that is assured. An OFS_DELTA longer than the hash size
1344 * is stupid, as then a REF_DELTA would be smaller to store.
1345 */
21666f1a 1346 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1347 unsigned used = 0;
1348 unsigned char c = base_info[used++];
1349 base_offset = c & 127;
1350 while (c & 128) {
1351 base_offset += 1;
8723f216 1352 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1353 return 0; /* overflow */
eb32d236
NP
1354 c = base_info[used++];
1355 base_offset = (base_offset << 7) + (c & 127);
1356 }
1357 base_offset = delta_obj_offset - base_offset;
1358 if (base_offset >= delta_obj_offset)
8eca0b47 1359 return 0; /* out of bound */
2b87c45b 1360 *curpos += used;
21666f1a 1361 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1362 /* The base entry _must_ be in the same pack */
1363 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1364 *curpos += 20;
eb32d236
NP
1365 } else
1366 die("I am totally screwed");
2b87c45b 1367 return base_offset;
eb32d236
NP
1368}
1369
f3bf9224 1370/* forward declaration for a mutually recursive function */
c4001d92 1371static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1372 unsigned long *sizep);
f3bf9224 1373
43057304 1374static int packed_delta_info(struct packed_git *p,
03e79c88 1375 struct pack_window **w_curs,
c4001d92 1376 off_t curpos,
21666f1a 1377 enum object_type type,
c4001d92 1378 off_t obj_offset,
43057304 1379 unsigned long *sizep)
5db47c2b 1380{
c4001d92 1381 off_t base_offset;
f3bf9224 1382
21666f1a
NP
1383 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1384 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1385
c62266f3
JH
1386 /* We choose to only get the type of the base object and
1387 * ignore potentially corrupt pack file that expects the delta
1388 * based on a base with a wrong size. This saves tons of
1389 * inflate() calls.
1390 */
54dab52a
NP
1391 if (sizep)
1392 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1393
1394 return type;
5db47c2b
JH
1395}
1396
2b87c45b
NP
1397static int unpack_object_header(struct packed_git *p,
1398 struct pack_window **w_curs,
c4001d92 1399 off_t *curpos,
2b87c45b 1400 unsigned long *sizep)
a733cb60 1401{
03e79c88
SP
1402 unsigned char *base;
1403 unsigned int left;
ad1ed5ee 1404 unsigned long used;
2b87c45b 1405 enum object_type type;
a733cb60 1406
8d8a4ea5
SP
1407 /* use_pack() assures us we have [base, base + 20) available
1408 * as a range that we can look at at. (Its actually the hash
3dff5379 1409 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1410 * the maximum deflated object size is 2^137, which is just
1411 * insane, so we know won't exceed what we have been given.
1412 */
2b87c45b
NP
1413 base = use_pack(p, w_curs, *curpos, &left);
1414 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1415 if (!used)
1416 die("object offset outside of pack file");
2b87c45b 1417 *curpos += used;
ad1ed5ee 1418
2b87c45b 1419 return type;
a733cb60
LT
1420}
1421
21666f1a 1422const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1423 off_t obj_offset,
21666f1a
NP
1424 unsigned long *size,
1425 unsigned long *store_size,
1426 unsigned int *delta_chain_length,
1427 unsigned char *base_sha1)
ad8c80a5 1428{
03e79c88 1429 struct pack_window *w_curs = NULL;
c4001d92
SP
1430 off_t curpos;
1431 unsigned long dummy;
43057304 1432 unsigned char *next_sha1;
21666f1a 1433 enum object_type type;
70f5d5d3 1434 struct revindex_entry *revidx;
ad8c80a5 1435
43057304 1436 *delta_chain_length = 0;
2b87c45b 1437 curpos = obj_offset;
21666f1a 1438 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304 1439
70f5d5d3
NP
1440 revidx = find_pack_revindex(p, obj_offset);
1441 *store_size = revidx[1].offset - obj_offset;
1442
43057304 1443 for (;;) {
21666f1a 1444 switch (type) {
43057304 1445 default:
08a19d87 1446 die("pack %s contains unknown object type %d",
21666f1a 1447 p->pack_name, type);
43057304
NP
1448 case OBJ_COMMIT:
1449 case OBJ_TREE:
1450 case OBJ_BLOB:
1451 case OBJ_TAG:
03e79c88 1452 unuse_pack(&w_curs);
21666f1a 1453 return typename(type);
eb32d236 1454 case OBJ_OFS_DELTA:
21666f1a 1455 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
8eca0b47
NP
1456 if (!obj_offset)
1457 die("pack %s contains bad delta base reference of type %s",
1458 p->pack_name, typename(type));
eb32d236 1459 if (*delta_chain_length == 0) {
70f5d5d3
NP
1460 revidx = find_pack_revindex(p, obj_offset);
1461 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
eb32d236
NP
1462 }
1463 break;
1464 case OBJ_REF_DELTA:
2b87c45b 1465 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1466 if (*delta_chain_length == 0)
1467 hashcpy(base_sha1, next_sha1);
2b87c45b 1468 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1469 break;
1470 }
43057304 1471 (*delta_chain_length)++;
2b87c45b 1472 curpos = obj_offset;
21666f1a 1473 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1474 }
ad8c80a5
JH
1475}
1476
c4001d92 1477static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1478 unsigned long *sizep)
1f688557 1479{
03e79c88 1480 struct pack_window *w_curs = NULL;
c4001d92
SP
1481 unsigned long size;
1482 off_t curpos = obj_offset;
21666f1a 1483 enum object_type type;
5db47c2b 1484
21666f1a 1485 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1486
21666f1a 1487 switch (type) {
eb32d236
NP
1488 case OBJ_OFS_DELTA:
1489 case OBJ_REF_DELTA:
21666f1a
NP
1490 type = packed_delta_info(p, &w_curs, curpos,
1491 type, obj_offset, sizep);
2b87c45b 1492 break;
a733cb60 1493 case OBJ_COMMIT:
a733cb60 1494 case OBJ_TREE:
a733cb60 1495 case OBJ_BLOB:
a733cb60 1496 case OBJ_TAG:
2b87c45b
NP
1497 if (sizep)
1498 *sizep = size;
a69d0943 1499 break;
1f688557 1500 default:
08a19d87 1501 die("pack %s contains unknown object type %d",
21666f1a 1502 p->pack_name, type);
1f688557 1503 }
2b87c45b 1504 unuse_pack(&w_curs);
21666f1a 1505 return type;
1f688557
JH
1506}
1507
eb950c19 1508static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1509 struct pack_window **w_curs,
c4001d92 1510 off_t curpos,
eb950c19 1511 unsigned long size)
de530aaa
SP
1512{
1513 int st;
1514 z_stream stream;
079afb18 1515 unsigned char *buffer, *in;
de530aaa
SP
1516
1517 buffer = xmalloc(size + 1);
1518 buffer[size] = 0;
1519 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1520 stream.next_out = buffer;
1521 stream.avail_out = size;
1522
1523 inflateInit(&stream);
079afb18 1524 do {
2b87c45b 1525 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1526 stream.next_in = in;
1527 st = inflate(&stream, Z_FINISH);
2b87c45b 1528 curpos += stream.next_in - in;
079afb18 1529 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1530 inflateEnd(&stream);
1531 if ((st != Z_STREAM_END) || stream.total_out != size) {
1532 free(buffer);
1533 return NULL;
1534 }
1535
1536 return buffer;
1537}
1538
e5e01619
LT
1539#define MAX_DELTA_CACHE (256)
1540
18bdec11 1541static size_t delta_base_cached;
5e08ecbf
NP
1542
1543static struct delta_base_cache_lru_list {
1544 struct delta_base_cache_lru_list *prev;
1545 struct delta_base_cache_lru_list *next;
1546} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1547
e5e01619 1548static struct delta_base_cache_entry {
5e08ecbf
NP
1549 struct delta_base_cache_lru_list lru;
1550 void *data;
e5e01619
LT
1551 struct packed_git *p;
1552 off_t base_offset;
1553 unsigned long size;
e5e01619
LT
1554 enum object_type type;
1555} delta_base_cache[MAX_DELTA_CACHE];
1556
1557static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1558{
1559 unsigned long hash;
1560
1561 hash = (unsigned long)p + (unsigned long)base_offset;
1562 hash += (hash >> 8) + (hash >> 16);
3358004a 1563 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1564}
1565
62f255ad 1566static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1567 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1568{
e5e01619
LT
1569 void *ret;
1570 unsigned long hash = pack_entry_hash(p, base_offset);
1571 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1572
1573 ret = ent->data;
749bc58c
MV
1574 if (!ret || ent->p != p || ent->base_offset != base_offset)
1575 return unpack_entry(p, base_offset, type, base_size);
e5e01619 1576
18bdec11 1577 if (!keep_cache) {
a0cba108 1578 ent->data = NULL;
5e08ecbf
NP
1579 ent->lru.next->prev = ent->lru.prev;
1580 ent->lru.prev->next = ent->lru.next;
18bdec11 1581 delta_base_cached -= ent->size;
182af834
PH
1582 } else {
1583 ret = xmemdupz(ent->data, ent->size);
a0cba108 1584 }
e5e01619
LT
1585 *type = ent->type;
1586 *base_size = ent->size;
1587 return ret;
62f255ad
LT
1588}
1589
18bdec11
SP
1590static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1591{
1592 if (ent->data) {
1593 free(ent->data);
1594 ent->data = NULL;
5e08ecbf
NP
1595 ent->lru.next->prev = ent->lru.prev;
1596 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1597 delta_base_cached -= ent->size;
1598 }
1599}
1600
62f255ad
LT
1601static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1602 void *base, unsigned long base_size, enum object_type type)
1603{
5e08ecbf 1604 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1605 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1606 struct delta_base_cache_lru_list *lru;
e5e01619 1607
18bdec11
SP
1608 release_delta_base_cache(ent);
1609 delta_base_cached += base_size;
5e08ecbf
NP
1610
1611 for (lru = delta_base_cache_lru.next;
1612 delta_base_cached > delta_base_cache_limit
1613 && lru != &delta_base_cache_lru;
1614 lru = lru->next) {
1615 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1616 if (f->type == OBJ_BLOB)
1617 release_delta_base_cache(f);
1618 }
5e08ecbf
NP
1619 for (lru = delta_base_cache_lru.next;
1620 delta_base_cached > delta_base_cache_limit
1621 && lru != &delta_base_cache_lru;
1622 lru = lru->next) {
1623 struct delta_base_cache_entry *f = (void *)lru;
1624 release_delta_base_cache(f);
1625 }
18bdec11 1626
e5e01619
LT
1627 ent->p = p;
1628 ent->base_offset = base_offset;
1629 ent->type = type;
1630 ent->data = base;
1631 ent->size = base_size;
5e08ecbf
NP
1632 ent->lru.next = &delta_base_cache_lru;
1633 ent->lru.prev = delta_base_cache_lru.prev;
1634 delta_base_cache_lru.prev->next = &ent->lru;
1635 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1636}
1637
eb950c19 1638static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1639 struct pack_window **w_curs,
c4001d92 1640 off_t curpos,
1f688557 1641 unsigned long delta_size,
c4001d92 1642 off_t obj_offset,
21666f1a 1643 enum object_type *type,
eb950c19 1644 unsigned long *sizep)
1f688557 1645{
7c3e8be3 1646 void *delta_data, *result, *base;
c4001d92
SP
1647 unsigned long base_size;
1648 off_t base_offset;
43057304 1649
21666f1a 1650 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
8eca0b47
NP
1651 if (!base_offset) {
1652 error("failed to validate delta base reference "
1653 "at offset %"PRIuMAX" from %s",
1654 (uintmax_t)curpos, p->pack_name);
1655 return NULL;
1656 }
eac12e2d 1657 unuse_pack(w_curs);
a0cba108 1658 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
8eca0b47
NP
1659 if (!base) {
1660 /*
1661 * We're probably in deep shit, but let's try to fetch
1662 * the required base anyway from another pack or loose.
1663 * This is costly but should happen only in the presence
1664 * of a corrupted pack, and is better than failing outright.
1665 */
1666 struct revindex_entry *revidx = find_pack_revindex(p, base_offset);
1667 const unsigned char *base_sha1 =
1668 nth_packed_object_sha1(p, revidx->nr);
1669 error("failed to read delta base object %s"
1670 " at offset %"PRIuMAX" from %s",
1671 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1672 p->pack_name);
1673 mark_bad_packed_object(p, base_sha1);
ac939109 1674 base = read_object(base_sha1, type, &base_size);
8eca0b47
NP
1675 if (!base)
1676 return NULL;
1677 }
67686d95 1678
2b87c45b 1679 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
8eca0b47
NP
1680 if (!delta_data) {
1681 error("failed to unpack compressed delta "
1682 "at offset %"PRIuMAX" from %s",
1683 (uintmax_t)curpos, p->pack_name);
1684 free(base);
1685 return NULL;
1686 }
1f688557
JH
1687 result = patch_delta(base, base_size,
1688 delta_data, delta_size,
21666f1a 1689 sizep);
1f688557
JH
1690 if (!result)
1691 die("failed to apply delta");
1692 free(delta_data);
62f255ad 1693 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1694 return result;
1695}
1696
c4001d92 1697void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1698 enum object_type *type, unsigned long *sizep)
1f688557 1699{
03e79c88 1700 struct pack_window *w_curs = NULL;
c4001d92 1701 off_t curpos = obj_offset;
21666f1a 1702 void *data;
1f688557 1703
21666f1a
NP
1704 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1705 switch (*type) {
eb32d236
NP
1706 case OBJ_OFS_DELTA:
1707 case OBJ_REF_DELTA:
21666f1a
NP
1708 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1709 obj_offset, type, sizep);
4d703a1a 1710 break;
a733cb60 1711 case OBJ_COMMIT:
a733cb60 1712 case OBJ_TREE:
a733cb60 1713 case OBJ_BLOB:
a733cb60 1714 case OBJ_TAG:
21666f1a 1715 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1716 break;
1f688557 1717 default:
8eca0b47
NP
1718 data = NULL;
1719 error("unknown object type %i at offset %"PRIuMAX" in %s",
1720 *type, (uintmax_t)obj_offset, p->pack_name);
1f688557 1721 }
03e79c88 1722 unuse_pack(&w_curs);
21666f1a 1723 return data;
1f688557
JH
1724}
1725
d079837e 1726const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1727 uint32_t n)
9a217f2a 1728{
42873078 1729 const unsigned char *index = p->index_data;
d079837e
SP
1730 if (!index) {
1731 if (open_pack_index(p))
1732 return NULL;
1733 index = p->index_data;
1734 }
57059091 1735 if (n >= p->num_objects)
d72308e0 1736 return NULL;
74e34e1f
NP
1737 index += 4 * 256;
1738 if (p->index_version == 1) {
1739 return index + 24 * n + 4;
1740 } else {
1741 index += 8;
1742 return index + 20 * n;
1743 }
1744}
1745
99093238 1746off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
1747{
1748 const unsigned char *index = p->index_data;
1749 index += 4 * 256;
1750 if (p->index_version == 1) {
1751 return ntohl(*((uint32_t *)(index + 24 * n)));
1752 } else {
1753 uint32_t off;
1754 index += 8 + p->num_objects * (20 + 4);
1755 off = ntohl(*((uint32_t *)(index + 4 * n)));
1756 if (!(off & 0x80000000))
1757 return off;
1758 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1759 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1760 ntohl(*((uint32_t *)(index + 4)));
1761 }
9a217f2a
JH
1762}
1763
c4001d92 1764off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1765 struct packed_git *p)
1f688557 1766{
42873078 1767 const uint32_t *level1_ofs = p->index_data;
42873078 1768 const unsigned char *index = p->index_data;
628522ec
JH
1769 unsigned hi, lo, stride;
1770 static int use_lookup = -1;
1771 static int debug_lookup = -1;
1772
1773 if (debug_lookup < 0)
1774 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1775
d079837e
SP
1776 if (!index) {
1777 if (open_pack_index(p))
1778 return 0;
1779 level1_ofs = p->index_data;
1780 index = p->index_data;
1781 }
74e34e1f
NP
1782 if (p->index_version > 1) {
1783 level1_ofs += 2;
1784 index += 8;
1785 }
42873078 1786 index += 4 * 256;
74e34e1f
NP
1787 hi = ntohl(level1_ofs[*sha1]);
1788 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
1789 if (p->index_version > 1) {
1790 stride = 20;
1791 } else {
1792 stride = 24;
1793 index += 4;
1794 }
1795
1796 if (debug_lookup)
6e1c2344 1797 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
1798 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1799
1800 if (use_lookup < 0)
1801 use_lookup = !!getenv("GIT_USE_LOOKUP");
1802 if (use_lookup) {
1803 int pos = sha1_entry_pos(index, stride, 0,
1804 lo, hi, p->num_objects, sha1);
1805 if (pos < 0)
1806 return 0;
1807 return nth_packed_object_offset(p, pos);
1808 }
1f688557
JH
1809
1810 do {
74e34e1f 1811 unsigned mi = (lo + hi) / 2;
628522ec
JH
1812 int cmp = hashcmp(index + mi * stride, sha1);
1813
1814 if (debug_lookup)
1815 printf("lo %u hi %u rg %u mi %u\n",
1816 lo, hi, hi - lo, mi);
43057304 1817 if (!cmp)
74e34e1f 1818 return nth_packed_object_offset(p, mi);
1f688557
JH
1819 if (cmp > 0)
1820 hi = mi;
1821 else
1822 lo = mi+1;
1823 } while (lo < hi);
1824 return 0;
1825}
1826
000dfd3f 1827int matches_pack_name(struct packed_git *p, const char *name)
d4ff6d92
SP
1828{
1829 const char *last_c, *c;
1830
000dfd3f
JH
1831 if (!strcmp(p->pack_name, name))
1832 return 1;
d4ff6d92
SP
1833
1834 for (c = p->pack_name, last_c = c; *c;)
1835 if (*c == '/')
1836 last_c = ++c;
1837 else
1838 ++c;
000dfd3f
JH
1839 if (!strcmp(last_c, name))
1840 return 1;
d4ff6d92 1841
000dfd3f 1842 return 0;
d4ff6d92
SP
1843}
1844
106d710b 1845static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1846{
f7c22cc6 1847 static struct packed_git *last_found = (void *)1;
1f688557 1848 struct packed_git *p;
c4001d92 1849 off_t offset;
43057304 1850
1f688557 1851 prepare_packed_git();
f7c22cc6
NP
1852 if (!packed_git)
1853 return 0;
1854 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1855
f7c22cc6 1856 do {
106d710b
JH
1857 if (ignore_packed) {
1858 const char **ig;
1859 for (ig = ignore_packed; *ig; ig++)
000dfd3f 1860 if (matches_pack_name(p, *ig))
106d710b
JH
1861 break;
1862 if (*ig)
f7c22cc6 1863 goto next;
106d710b 1864 }
f7c22cc6 1865
8eca0b47
NP
1866 if (p->num_bad_objects) {
1867 unsigned i;
1868 for (i = 0; i < p->num_bad_objects; i++)
1869 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1870 goto next;
1871 }
1872
43057304
NP
1873 offset = find_pack_entry_one(sha1, p);
1874 if (offset) {
c715f783
SP
1875 /*
1876 * We are about to tell the caller where they can
1877 * locate the requested object. We better make
1878 * sure the packfile is still here and can be
1879 * accessed before supplying that answer, as
1880 * it may have been deleted since the index
1881 * was loaded!
1882 */
1883 if (p->pack_fd == -1 && open_packed_git(p)) {
1884 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1885 goto next;
c715f783 1886 }
43057304
NP
1887 e->offset = offset;
1888 e->p = p;
1889 hashcpy(e->sha1, sha1);
f7c22cc6 1890 last_found = p;
1f688557 1891 return 1;
43057304 1892 }
f7c22cc6
NP
1893
1894 next:
1895 if (p == last_found)
1896 p = packed_git;
1897 else
1898 p = p->next;
1899 if (p == last_found)
1900 p = p->next;
1901 } while (p);
1f688557
JH
1902 return 0;
1903}
1904
a6080a0a 1905struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1906 struct packed_git *packs)
1907{
1908 struct packed_git *p;
bf592c50
DB
1909
1910 for (p = packs; p; p = p->next) {
43057304 1911 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1912 return p;
1913 }
1914 return NULL;
21666f1a 1915
bf592c50
DB
1916}
1917
21666f1a 1918static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1919{
36e4d74a 1920 int status;
65c2e0c3
JH
1921 unsigned long mapsize, size;
1922 void *map;
1923 z_stream stream;
d65a16f6 1924 char hdr[32];
65c2e0c3 1925
bb6b8e4f 1926 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1927 if (!map)
1928 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1929 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1930 status = error("unable to unpack %s header",
1931 sha1_to_hex(sha1));
21666f1a 1932 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1933 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1934 else if (sizep)
1935 *sizep = size;
65c2e0c3
JH
1936 inflateEnd(&stream);
1937 munmap(map, mapsize);
1938 return status;
1939}
1940
21666f1a 1941int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1942{
f0df4ed5 1943 struct pack_entry e;
ddd63e64 1944 int status;
f0df4ed5
JS
1945
1946 if (!find_pack_entry(sha1, &e, NULL)) {
ddd63e64
SG
1947 /* Most likely it's a loose object. */
1948 status = sha1_loose_object_info(sha1, sizep);
1949 if (status >= 0)
1950 return status;
1951
1952 /* Not a loose object; someone else may have just packed it. */
f0df4ed5
JS
1953 reprepare_packed_git();
1954 if (!find_pack_entry(sha1, &e, NULL))
ddd63e64 1955 return status;
f0df4ed5 1956 }
21666f1a 1957 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1958}
1959
21666f1a
NP
1960static void *read_packed_sha1(const unsigned char *sha1,
1961 enum object_type *type, unsigned long *size)
1f688557
JH
1962{
1963 struct pack_entry e;
8eca0b47 1964 void *data;
1f688557 1965
8276c007 1966 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1967 return NULL;
8eca0b47
NP
1968 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1969 if (!data) {
1970 /*
1971 * We're probably in deep shit, but let's try to fetch
1972 * the required object anyway from another pack or loose.
1973 * This should happen only in the presence of a corrupted
1974 * pack, and is better than failing outright.
1975 */
1976 error("failed to read object %s at offset %"PRIuMAX" from %s",
1977 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1978 mark_bad_packed_object(e.p, sha1);
ac939109 1979 data = read_object(sha1, type, size);
8eca0b47
NP
1980 }
1981 return data;
1f688557
JH
1982}
1983
d66b37bb
JH
1984/*
1985 * This is meant to hold a *small* number of objects that you would
1986 * want read_sha1_file() to be able to return, but yet you do not want
1987 * to write them into the object store (e.g. a browse-only
1988 * application).
1989 */
1990static struct cached_object {
1991 unsigned char sha1[20];
21666f1a 1992 enum object_type type;
d66b37bb
JH
1993 void *buf;
1994 unsigned long size;
1995} *cached_objects;
1996static int cached_object_nr, cached_object_alloc;
1997
346245a1
JK
1998static struct cached_object empty_tree = {
1999 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
2000 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
2001 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
2002 OBJ_TREE,
2003 "",
2004 0
2005};
2006
d66b37bb
JH
2007static struct cached_object *find_cached_object(const unsigned char *sha1)
2008{
2009 int i;
2010 struct cached_object *co = cached_objects;
2011
2012 for (i = 0; i < cached_object_nr; i++, co++) {
2013 if (!hashcmp(co->sha1, sha1))
2014 return co;
2015 }
346245a1
JK
2016 if (!hashcmp(sha1, empty_tree.sha1))
2017 return &empty_tree;
d66b37bb
JH
2018 return NULL;
2019}
2020
21666f1a
NP
2021int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2022 unsigned char *sha1)
d66b37bb
JH
2023{
2024 struct cached_object *co;
2025
21666f1a 2026 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2027 if (has_sha1_file(sha1) || find_cached_object(sha1))
2028 return 0;
2029 if (cached_object_alloc <= cached_object_nr) {
2030 cached_object_alloc = alloc_nr(cached_object_alloc);
2031 cached_objects = xrealloc(cached_objects,
2032 sizeof(*cached_objects) *
2033 cached_object_alloc);
2034 }
2035 co = &cached_objects[cached_object_nr++];
2036 co->size = len;
21666f1a 2037 co->type = type;
efa13f7b
JH
2038 co->buf = xmalloc(len);
2039 memcpy(co->buf, buf, len);
d66b37bb
JH
2040 hashcpy(co->sha1, sha1);
2041 return 0;
2042}
2043
ac939109
NP
2044void *read_object(const unsigned char *sha1, enum object_type *type,
2045 unsigned long *size)
0fcfd160
LT
2046{
2047 unsigned long mapsize;
2048 void *map, *buf;
d66b37bb
JH
2049 struct cached_object *co;
2050
2051 co = find_cached_object(sha1);
2052 if (co) {
21666f1a 2053 *type = co->type;
d66b37bb 2054 *size = co->size;
182af834 2055 return xmemdupz(co->buf, co->size);
d66b37bb 2056 }
0fcfd160 2057
8276c007
PE
2058 buf = read_packed_sha1(sha1, type, size);
2059 if (buf)
2060 return buf;
bb6b8e4f 2061 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2062 if (map) {
7efbff75 2063 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2064 munmap(map, mapsize);
2065 return buf;
2066 }
637cdd9d 2067 reprepare_packed_git();
8276c007 2068 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2069}
2070
ac939109
NP
2071void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
2072 unsigned long *size)
2073{
2074 void *data = read_object(sha1, type, size);
2075 /* legacy behavior is to die on corrupted objects */
2076 if (!data && (has_loose_object(sha1) || has_packed_and_bad(sha1)))
2077 die("object %s is corrupted", sha1_to_hex(sha1));
2078 return data;
2079}
2080
40469ee9 2081void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2082 const char *required_type_name,
40469ee9
JH
2083 unsigned long *size,
2084 unsigned char *actual_sha1_return)
f4913f91 2085{
21666f1a 2086 enum object_type type, required_type;
f4913f91
JH
2087 void *buffer;
2088 unsigned long isize;
40469ee9 2089 unsigned char actual_sha1[20];
f4913f91 2090
21666f1a 2091 required_type = type_from_string(required_type_name);
e702496e 2092 hashcpy(actual_sha1, sha1);
40469ee9
JH
2093 while (1) {
2094 int ref_length = -1;
2095 const char *ref_type = NULL;
f4913f91 2096
21666f1a 2097 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2098 if (!buffer)
2099 return NULL;
21666f1a 2100 if (type == required_type) {
40469ee9
JH
2101 *size = isize;
2102 if (actual_sha1_return)
e702496e 2103 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2104 return buffer;
2105 }
2106 /* Handle references */
21666f1a 2107 else if (type == OBJ_COMMIT)
40469ee9 2108 ref_type = "tree ";
21666f1a 2109 else if (type == OBJ_TAG)
40469ee9
JH
2110 ref_type = "object ";
2111 else {
2112 free(buffer);
2113 return NULL;
2114 }
2115 ref_length = strlen(ref_type);
f4913f91 2116
50974ec9
MK
2117 if (ref_length + 40 > isize ||
2118 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2119 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2120 free(buffer);
2121 return NULL;
2122 }
1cf58e72 2123 free(buffer);
40469ee9
JH
2124 /* Now we have the ID of the referred-to object in
2125 * actual_sha1. Check again. */
f4913f91 2126 }
f4913f91
JH
2127}
2128
ce9fbf16 2129static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2130 const char *type, unsigned char *sha1,
d65a16f6 2131 char *hdr, int *hdrlen)
d410c0f5 2132{
9126f009 2133 git_SHA_CTX c;
d410c0f5
JH
2134
2135 /* Generate the header */
d65a16f6 2136 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2137
2138 /* Sha1.. */
9126f009
NP
2139 git_SHA1_Init(&c);
2140 git_SHA1_Update(&c, hdr, *hdrlen);
2141 git_SHA1_Update(&c, buf, len);
2142 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2143}
2144
230f1322
LT
2145/*
2146 * Move the just written object into its final resting place
2147 */
839837b9 2148int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2149{
e32c0a9c
TR
2150 int ret = 0;
2151 if (link(tmpfile, filename))
2152 ret = errno;
7ebb6fca
LT
2153
2154 /*
2155 * Coda hack - coda doesn't like cross-directory links,
2156 * so we fall back to a rename, which will mean that it
2157 * won't be able to check collisions, but that's not a
2158 * big deal.
2159 *
2160 * The same holds for FAT formatted media.
2161 *
2162 * When this succeeds, we just return 0. We have nothing
2163 * left to unlink.
2164 */
2165 if (ret && ret != EEXIST) {
2166 if (!rename(tmpfile, filename))
230f1322 2167 return 0;
9e48b389 2168 ret = errno;
230f1322
LT
2169 }
2170 unlink(tmpfile);
2171 if (ret) {
2172 if (ret != EEXIST) {
916d081b 2173 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2174 }
2175 /* FIXME!!! Collision check here ? */
2176 }
2177
2178 return 0;
2179}
2180
4d548150
LT
2181static int write_buffer(int fd, const void *buf, size_t len)
2182{
d34cf19b 2183 if (write_in_full(fd, buf, len) < 0)
93822c22 2184 return error("file write error (%s)", strerror(errno));
4d548150
LT
2185 return 0;
2186}
2187
ce9fbf16 2188int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2189 unsigned char *sha1)
2190{
d65a16f6 2191 char hdr[32];
abdc3fc8
RS
2192 int hdrlen;
2193 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2194 return 0;
2195}
2196
e9039dd3
LT
2197/* Finalize a file on disk, and close it. */
2198static void close_sha1_file(int fd)
2199{
aafe9fba
LT
2200 if (fsync_object_files)
2201 fsync_or_die(fd, "sha1 file");
e9039dd3
LT
2202 fchmod(fd, 0444);
2203 if (close(fd) != 0)
2204 die("unable to write sha1 file");
2205}
2206
5723fe7e
LT
2207/* Size of directory component, including the ending '/' */
2208static inline int directory_size(const char *filename)
2209{
2210 const char *s = strrchr(filename, '/');
2211 if (!s)
2212 return 0;
2213 return s - filename + 1;
2214}
2215
2216/*
2217 * This creates a temporary file in the same directory as the final
2218 * 'filename'
2219 *
2220 * We want to avoid cross-directory filename renames, because those
2221 * can have problems on various filesystems (FAT, NFS, Coda).
2222 */
2223static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2224{
2225 int fd, dirlen = directory_size(filename);
2226
2227 if (dirlen + 20 > bufsiz) {
2228 errno = ENAMETOOLONG;
2229 return -1;
2230 }
2231 memcpy(buffer, filename, dirlen);
2232 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2233 fd = mkstemp(buffer);
2234 if (fd < 0 && dirlen) {
2235 /* Make sure the directory exists */
6ff6af62 2236 memcpy(buffer, filename, dirlen);
5723fe7e 2237 buffer[dirlen-1] = 0;
3bfaf018 2238 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2239 return -1;
2240
2241 /* Try again */
2242 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2243 fd = mkstemp(buffer);
2244 }
2245 return fd;
2246}
2247
bbac7311
NP
2248static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2249 void *buf, unsigned long len, time_t mtime)
0fcfd160 2250{
bbac7311 2251 int fd, size, ret;
bf0f910d 2252 unsigned char *compressed;
0fcfd160 2253 z_stream stream;
706bc531 2254 char *filename;
aac17941 2255 static char tmpfile[PATH_MAX];
a44c9a5e 2256
972a9155 2257 filename = sha1_file_name(sha1);
5723fe7e 2258 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
aac17941 2259 if (fd < 0) {
916d081b
PB
2260 if (errno == EPERM)
2261 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2262 else
2263 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2264 }
2265
0fcfd160
LT
2266 /* Set it up */
2267 memset(&stream, 0, sizeof(stream));
12f6c308 2268 deflateInit(&stream, zlib_compression_level);
93821bd9 2269 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2270 compressed = xmalloc(size);
0fcfd160
LT
2271
2272 /* Compress it */
0fcfd160
LT
2273 stream.next_out = compressed;
2274 stream.avail_out = size;
a44c9a5e
LT
2275
2276 /* First header.. */
d65a16f6 2277 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2278 stream.avail_in = hdrlen;
726f852b
NP
2279 while (deflate(&stream, 0) == Z_OK)
2280 /* nothing */;
a44c9a5e
LT
2281
2282 /* Then the data itself.. */
2283 stream.next_in = buf;
2284 stream.avail_in = len;
ac54c277
LT
2285 ret = deflate(&stream, Z_FINISH);
2286 if (ret != Z_STREAM_END)
2287 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2288
2289 ret = deflateEnd(&stream);
2290 if (ret != Z_OK)
2291 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2292
0fcfd160
LT
2293 size = stream.total_out;
2294
4d548150
LT
2295 if (write_buffer(fd, compressed, size) < 0)
2296 die("unable to write sha1 file");
e9039dd3 2297 close_sha1_file(fd);
383f85b7 2298 free(compressed);
0fcfd160 2299
bbac7311
NP
2300 if (mtime) {
2301 struct utimbuf utb;
2302 utb.actime = mtime;
2303 utb.modtime = mtime;
2304 if (utime(tmpfile, &utb) < 0)
2305 warning("failed utime() on %s: %s",
2306 tmpfile, strerror(errno));
2307 }
2308
230f1322 2309 return move_temp_to_file(tmpfile, filename);
0fcfd160 2310}
8237b185 2311
bbac7311
NP
2312int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2313{
2314 unsigned char sha1[20];
2315 char hdr[32];
2316 int hdrlen;
2317
2318 /* Normally if we have it in the pack then we do not bother writing
2319 * it out into .git/objects/??/?{38} file.
2320 */
2321 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2322 if (returnsha1)
2323 hashcpy(returnsha1, sha1);
2324 if (has_sha1_file(sha1))
2325 return 0;
2326 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2327}
2328
2329int force_object_loose(const unsigned char *sha1, time_t mtime)
2330{
bbac7311
NP
2331 void *buf;
2332 unsigned long len;
2333 enum object_type type;
2334 char hdr[32];
2335 int hdrlen;
1fb23e65 2336 int ret;
bbac7311 2337
c529d75a 2338 if (has_loose_object(sha1))
bbac7311
NP
2339 return 0;
2340 buf = read_packed_sha1(sha1, &type, &len);
2341 if (!buf)
2342 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2343 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1fb23e65
BS
2344 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2345 free(buf);
2346
2347 return ret;
bbac7311
NP
2348}
2349
bf592c50
DB
2350int has_pack_index(const unsigned char *sha1)
2351{
2352 struct stat st;
2353 if (stat(sha1_pack_index_name(sha1), &st))
2354 return 0;
2355 return 1;
2356}
2357
2358int has_pack_file(const unsigned char *sha1)
2359{
2360 struct stat st;
2361 if (stat(sha1_pack_name(sha1), &st))
2362 return 0;
2363 return 1;
2364}
2365
106d710b 2366int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2367{
2368 struct pack_entry e;
106d710b 2369 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2370}
2371
8237b185
DB
2372int has_sha1_file(const unsigned char *sha1)
2373{
1f688557
JH
2374 struct pack_entry e;
2375
106d710b 2376 if (find_pack_entry(sha1, &e, NULL))
1f688557 2377 return 1;
c529d75a 2378 return has_loose_object(sha1);
8237b185 2379}
74400e71 2380
43df4f86
DP
2381static int index_mem(unsigned char *sha1, void *buf, size_t size,
2382 int write_object, enum object_type type, const char *path)
e7332f96 2383{
6c510bee 2384 int ret, re_allocated = 0;
74400e71 2385
7672db20 2386 if (!type)
edaec3fb 2387 type = OBJ_BLOB;
6c510bee
LT
2388
2389 /*
2390 * Convert blobs to git internal format
2391 */
43df4f86 2392 if ((type == OBJ_BLOB) && path) {
f285a2d7 2393 struct strbuf nbuf = STRBUF_INIT;
21e5ad50
SP
2394 if (convert_to_git(path, buf, size, &nbuf,
2395 write_object ? safe_crlf : 0)) {
b315c5c0 2396 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2397 re_allocated = 1;
2398 }
2399 }
2400
7672db20 2401 if (write_object)
edaec3fb 2402 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2403 else
edaec3fb 2404 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 2405 if (re_allocated)
6c510bee 2406 free(buf);
43df4f86
DP
2407 return ret;
2408}
2409
2410int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2411 enum object_type type, const char *path)
2412{
2413 int ret;
2414 size_t size = xsize_t(st->st_size);
2415
2416 if (!S_ISREG(st->st_mode)) {
f285a2d7 2417 struct strbuf sbuf = STRBUF_INIT;
43df4f86
DP
2418 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2419 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2420 type, path);
2421 else
2422 ret = -1;
2423 strbuf_release(&sbuf);
2424 } else if (size) {
2425 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2426 ret = index_mem(sha1, buf, size, write_object, type, path);
aac17941 2427 munmap(buf, size);
43df4f86
DP
2428 } else
2429 ret = index_mem(sha1, NULL, size, write_object, type, path);
2430 close(fd);
aac17941 2431 return ret;
74400e71 2432}
ec1fcc16
JH
2433
2434int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2435{
2436 int fd;
2437 char *target;
dc49cd76 2438 size_t len;
ec1fcc16
JH
2439
2440 switch (st->st_mode & S_IFMT) {
2441 case S_IFREG:
2442 fd = open(path, O_RDONLY);
2443 if (fd < 0)
2444 return error("open(\"%s\"): %s", path,
2445 strerror(errno));
53bca91a 2446 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2447 return error("%s: failed to insert into database",
2448 path);
2449 break;
2450 case S_IFLNK:
dc49cd76
SP
2451 len = xsize_t(st->st_size);
2452 target = xmalloc(len + 1);
2453 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2454 char *errstr = strerror(errno);
2455 free(target);
2456 return error("readlink(\"%s\"): %s", path,
2457 errstr);
2458 }
abdc3fc8 2459 if (!write_object)
dc49cd76
SP
2460 hash_sha1_file(target, len, blob_type, sha1);
2461 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2462 return error("%s: failed to insert into database",
2463 path);
2464 free(target);
2465 break;
f35a6d3b
LT
2466 case S_IFDIR:
2467 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2468 default:
2469 return error("%s: unsupported file type", path);
2470 }
2471 return 0;
2472}
a69e5429
JH
2473
2474int read_pack_header(int fd, struct pack_header *header)
2475{
c697ad14
HO
2476 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2477 /* "eof before pack header was fully read" */
2478 return PH_ERROR_EOF;
2479
a69e5429
JH
2480 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2481 /* "protocol error (pack signature mismatch detected)" */
2482 return PH_ERROR_PACK_SIGNATURE;
2483 if (!pack_version_ok(header->hdr_version))
2484 /* "protocol error (pack version unsupported)" */
2485 return PH_ERROR_PROTOCOL;
2486 return 0;
2487}