work around Python warnings from AsciiDoc
[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;
102 *pos = 0;
67d42212
JR
103 if (!stat(path, &st)) {
104 /* path exists */
105 if (!S_ISDIR(st.st_mode)) {
b2cb9425 106 *pos = '/';
67d42212 107 return -3;
b2cb9425 108 }
457f06d6 109 }
67d42212
JR
110 else if (mkdir(path, 0777)) {
111 *pos = '/';
112 return -1;
113 }
457f06d6
JS
114 else if (adjust_shared_perm(path)) {
115 *pos = '/';
116 return -2;
117 }
b2cb9425
JH
118 *pos++ = '/';
119 }
120 return 0;
121}
723c31fe 122
8e21d63b
JK
123int safe_create_leading_directories_const(const char *path)
124{
125 /* path points to cache entries, so xstrdup before messing with it */
126 char *buf = xstrdup(path);
127 int result = safe_create_leading_directories(buf);
128 free(buf);
129 return result;
130}
131
3bfaf018 132char *sha1_to_hex(const unsigned char *sha1)
0fcfd160 133{
dcb3450f
LT
134 static int bufno;
135 static char hexbuffer[4][50];
0fcfd160 136 static const char hex[] = "0123456789abcdef";
dcb3450f 137 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
138 int i;
139
140 for (i = 0; i < 20; i++) {
141 unsigned int val = *sha1++;
142 *buf++ = hex[val >> 4];
143 *buf++ = hex[val & 0xf];
144 }
1e80e044
JS
145 *buf = '\0';
146
0fcfd160
LT
147 return buffer;
148}
149
ace1534d
JH
150static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
151{
152 int i;
153 for (i = 0; i < 20; i++) {
154 static char hex[] = "0123456789abcdef";
155 unsigned int val = sha1[i];
156 char *pos = pathbuf + i*2 + (i > 0);
157 *pos++ = hex[val >> 4];
158 *pos = hex[val & 0xf];
159 }
160}
161
0fcfd160
LT
162/*
163 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 164 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 165 * filename.
ace1534d
JH
166 *
167 * Also note that this returns the location for creating. Reading
168 * SHA1 file can happen from any alternate directory listed in the
d19938ab 169 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 170 * the primary object database.
0fcfd160
LT
171 */
172char *sha1_file_name(const unsigned char *sha1)
173{
0fcfd160
LT
174 static char *name, *base;
175
176 if (!base) {
d19938ab 177 const char *sha1_file_directory = get_object_directory();
0fcfd160 178 int len = strlen(sha1_file_directory);
812666c8 179 base = xmalloc(len + 60);
0fcfd160
LT
180 memcpy(base, sha1_file_directory, len);
181 memset(base+len, 0, 60);
182 base[len] = '/';
183 base[len+3] = '/';
184 name = base + len + 1;
185 }
ace1534d 186 fill_sha1_path(name, sha1);
0fcfd160
LT
187 return base;
188}
189
633f43e1 190static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 191 char **name, char **base, const char *which)
bf592c50
DB
192{
193 static const char hex[] = "0123456789abcdef";
633f43e1 194 char *buf;
bf592c50
DB
195 int i;
196
633f43e1 197 if (!*base) {
bf592c50
DB
198 const char *sha1_file_directory = get_object_directory();
199 int len = strlen(sha1_file_directory);
633f43e1 200 *base = xmalloc(len + 60);
6eec46bd
JH
201 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
202 sha1_file_directory, which);
633f43e1 203 *name = *base + len + 11;
bf592c50
DB
204 }
205
633f43e1 206 buf = *name;
bf592c50
DB
207
208 for (i = 0; i < 20; i++) {
209 unsigned int val = *sha1++;
210 *buf++ = hex[val >> 4];
211 *buf++ = hex[val & 0xf];
212 }
a6080a0a 213
633f43e1 214 return *base;
bf592c50
DB
215}
216
633f43e1 217char *sha1_pack_name(const unsigned char *sha1)
bf592c50 218{
633f43e1 219 static char *name, *base;
bf592c50 220
6eec46bd 221 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 222}
bf592c50 223
633f43e1
HO
224char *sha1_pack_index_name(const unsigned char *sha1)
225{
226 static char *name, *base;
a6080a0a 227
6eec46bd 228 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
229}
230
d5a63b99
JH
231struct alternate_object_database *alt_odb_list;
232static struct alternate_object_database **alt_odb_tail;
ace1534d 233
c2f493a4
MW
234static void read_info_alternates(const char * alternates, int depth);
235
ddd5d056
JH
236/*
237 * Prepare alternate object database registry.
d5a63b99
JH
238 *
239 * The variable alt_odb_list points at the list of struct
240 * alternate_object_database. The elements on this list come from
241 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
242 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
243 * whose contents is similar to that environment variable but can be
244 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
245 * contains "/the/directory/corresponding/to/.git/objects/...", while
246 * its name points just after the slash at the end of ".git/objects/"
247 * in the example above, and has enough space to hold 40-byte hex
248 * SHA1, an extra slash for the first level indirection, and the
249 * terminating NUL.
ddd5d056 250 */
c2f493a4 251static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 252{
c2f493a4 253 struct stat st;
1494e038 254 const char *objdir = get_object_directory();
c2f493a4
MW
255 struct alternate_object_database *ent;
256 struct alternate_object_database *alt;
257 /* 43 = 40-byte + 2 '/' + terminating NUL */
258 int pfxlen = len;
259 int entlen = pfxlen + 43;
ccfd3e99 260 int base_len = -1;
d5a63b99 261
85dadc38 262 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
263 /* Relative alt-odb */
264 if (base_len < 0)
265 base_len = strlen(relative_base) + 1;
266 entlen += base_len;
267 pfxlen += base_len;
268 }
269 ent = xmalloc(sizeof(*ent) + entlen);
270
85dadc38 271 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
272 memcpy(ent->base, relative_base, base_len - 1);
273 ent->base[base_len - 1] = '/';
274 memcpy(ent->base + base_len, entry, len);
275 }
276 else
277 memcpy(ent->base, entry, pfxlen);
278
279 ent->name = ent->base + pfxlen + 1;
280 ent->base[pfxlen + 3] = '/';
281 ent->base[pfxlen] = ent->base[entlen-1] = 0;
282
283 /* Detect cases where alternate disappeared */
284 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
285 error("object directory %s does not exist; "
286 "check .git/objects/info/alternates.",
287 ent->base);
288 free(ent);
289 return -1;
290 }
291
292 /* Prevent the common mistake of listing the same
293 * thing twice, or object directory itself.
294 */
295 for (alt = alt_odb_list; alt; alt = alt->next) {
296 if (!memcmp(ent->base, alt->base, pfxlen)) {
297 free(ent);
298 return -1;
299 }
300 }
301 if (!memcmp(ent->base, objdir, pfxlen)) {
302 free(ent);
303 return -1;
304 }
305
306 /* add the alternate entry */
307 *alt_odb_tail = ent;
308 alt_odb_tail = &(ent->next);
309 ent->next = NULL;
310
311 /* recursively add alternates */
312 read_info_alternates(ent->base, depth + 1);
313
314 ent->base[pfxlen] = '/';
315
316 return 0;
317}
318
319static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
320 const char *relative_base, int depth)
321{
322 const char *cp, *last;
323
324 if (depth > 5) {
325 error("%s: ignoring alternate object stores, nesting too deep.",
326 relative_base);
327 return;
328 }
329
d5a63b99 330 last = alt;
9577e7e3
JH
331 while (last < ep) {
332 cp = last;
333 if (cp < ep && *cp == '#') {
334 while (cp < ep && *cp != sep)
335 cp++;
336 last = cp + 1;
337 continue;
338 }
c2f493a4
MW
339 while (cp < ep && *cp != sep)
340 cp++;
d5a63b99 341 if (last != cp) {
85dadc38 342 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
343 error("%s: ignoring relative alternate object store %s",
344 relative_base, last);
345 } else {
346 link_alt_odb_entry(last, cp - last,
347 relative_base, depth);
1494e038 348 }
d5a63b99 349 }
9577e7e3 350 while (cp < ep && *cp == sep)
d5a63b99
JH
351 cp++;
352 last = cp;
9577e7e3 353 }
d5a63b99
JH
354}
355
c2f493a4 356static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 357{
9577e7e3 358 char *map;
dc49cd76 359 size_t mapsz;
d5a63b99 360 struct stat st;
9cb18f56
JM
361 const char alt_file_name[] = "info/alternates";
362 /* Given that relative_base is no longer than PATH_MAX,
363 ensure that "path" has enough space to append "/", the
364 file name, "info/alternates", and a trailing NUL. */
365 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 366 int fd;
d5a63b99 367
9cb18f56 368 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
369 fd = open(path, O_RDONLY);
370 if (fd < 0)
371 return;
372 if (fstat(fd, &st) || (st.st_size == 0)) {
373 close(fd);
9a217f2a 374 return;
ace1534d 375 }
dc49cd76
SP
376 mapsz = xsize_t(st.st_size);
377 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 378 close(fd);
d5a63b99 379
dc49cd76 380 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 381
dc49cd76 382 munmap(map, mapsz);
ace1534d
JH
383}
384
bef70b22
DB
385void add_to_alternates_file(const char *reference)
386{
387 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
acd3b9ec 388 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
bef70b22
DB
389 char *alt = mkpath("%s/objects\n", reference);
390 write_or_die(fd, alt, strlen(alt));
391 if (commit_lock_file(lock))
392 die("could not close alternates file");
393 if (alt_odb_tail)
394 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
395}
396
c2f493a4
MW
397void prepare_alt_odb(void)
398{
554fe20d 399 const char *alt;
c2f493a4 400
7dc24aa5
SP
401 if (alt_odb_tail)
402 return;
403
c2f493a4
MW
404 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
405 if (!alt) alt = "";
406
c2f493a4 407 alt_odb_tail = &alt_odb_list;
80ba074f 408 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
409
410 read_info_alternates(get_object_directory(), 0);
411}
412
0f4dc14a 413static int has_loose_object_local(const unsigned char *sha1)
ace1534d 414{
ace1534d 415 char *name = sha1_file_name(sha1);
0f4dc14a
BC
416 return !access(name, F_OK);
417}
ace1534d 418
0f4dc14a
BC
419int has_loose_object_nonlocal(const unsigned char *sha1)
420{
421 struct alternate_object_database *alt;
9a217f2a 422 prepare_alt_odb();
d5a63b99 423 for (alt = alt_odb_list; alt; alt = alt->next) {
0f4dc14a 424 fill_sha1_path(alt->name, sha1);
c529d75a
LT
425 if (!access(alt->base, F_OK))
426 return 1;
ace1534d 427 }
c529d75a 428 return 0;
ace1534d
JH
429}
430
0f4dc14a
BC
431static int has_loose_object(const unsigned char *sha1)
432{
433 return has_loose_object_local(sha1) ||
434 has_loose_object_nonlocal(sha1);
435}
436
60bb8b14 437static unsigned int pack_used_ctr;
a53128b6
SP
438static unsigned int pack_mmap_calls;
439static unsigned int peak_pack_open_windows;
440static unsigned int pack_open_windows;
441static size_t peak_pack_mapped;
60bb8b14 442static size_t pack_mapped;
9a217f2a 443struct packed_git *packed_git;
1f688557 444
b79d18c9 445void pack_report(void)
a53128b6
SP
446{
447 fprintf(stderr,
e05db0fd
PR
448 "pack_report: getpagesize() = %10" SZ_FMT "\n"
449 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
450 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
451 sz_fmt(getpagesize()),
452 sz_fmt(packed_git_window_size),
453 sz_fmt(packed_git_limit));
a53128b6
SP
454 fprintf(stderr,
455 "pack_report: pack_used_ctr = %10u\n"
456 "pack_report: pack_mmap_calls = %10u\n"
457 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
458 "pack_report: pack_mapped = "
459 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
460 pack_used_ctr,
461 pack_mmap_calls,
462 pack_open_windows, peak_pack_open_windows,
9e42d6a1 463 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
464}
465
42873078 466static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
467{
468 void *idx_map;
42873078 469 struct pack_idx_header *hdr;
dc49cd76 470 size_t idx_size;
74e34e1f 471 uint32_t version, nr, i, *index;
e93ec6f9 472 int fd = open(path, O_RDONLY);
1f688557 473 struct stat st;
42873078 474
1f688557
JH
475 if (fd < 0)
476 return -1;
477 if (fstat(fd, &st)) {
478 close(fd);
479 return -1;
480 }
dc49cd76 481 idx_size = xsize_t(st.st_size);
2d88451b
SP
482 if (idx_size < 4 * 256 + 20 + 20) {
483 close(fd);
484 return error("index file %s is too small", path);
485 }
c4712e45 486 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 487 close(fd);
1f688557 488
42873078
NP
489 hdr = idx_map;
490 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
491 version = ntohl(hdr->idx_version);
492 if (version < 2 || version > 2) {
493 munmap(idx_map, idx_size);
6e1c2344 494 return error("index file %s is version %"PRIu32
74e34e1f
NP
495 " and is not supported by this binary"
496 " (try upgrading GIT to a newer version)",
497 path, version);
498 }
499 } else
500 version = 1;
df1b059d 501
1f688557 502 nr = 0;
42873078 503 index = idx_map;
74e34e1f
NP
504 if (version > 1)
505 index += 2; /* skip index header */
1f688557 506 for (i = 0; i < 256; i++) {
326bf396 507 uint32_t n = ntohl(index[i]);
2d88451b
SP
508 if (n < nr) {
509 munmap(idx_map, idx_size);
df1b059d 510 return error("non-monotonic index %s", path);
2d88451b 511 }
1f688557
JH
512 nr = n;
513 }
514
74e34e1f
NP
515 if (version == 1) {
516 /*
517 * Total size:
518 * - 256 index entries 4 bytes each
519 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
520 * - 20-byte SHA1 of the packfile
521 * - 20-byte SHA1 file checksum
522 */
523 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
524 munmap(idx_map, idx_size);
eef427a0 525 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
526 }
527 } else if (version == 2) {
528 /*
529 * Minimum size:
530 * - 8 bytes of header
531 * - 256 index entries 4 bytes each
532 * - 20-byte sha1 entry * nr
533 * - 4-byte crc entry * nr
534 * - 4-byte offset entry * nr
535 * - 20-byte SHA1 of the packfile
536 * - 20-byte SHA1 file checksum
537 * And after the 4-byte offset table might be a
538 * variable sized table containing 8-byte entries
539 * for offsets larger than 2^31.
540 */
541 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
542 unsigned long max_size = min_size;
543 if (nr)
544 max_size += (nr - 1)*8;
545 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 546 munmap(idx_map, idx_size);
eef427a0 547 return error("wrong index v2 file size in %s", path);
74e34e1f 548 }
7109c889
JH
549 if (idx_size != min_size &&
550 /*
551 * make sure we can deal with large pack offsets.
552 * 31-bit signed offset won't be enough, neither
553 * 32-bit unsigned one will be.
554 */
555 (sizeof(off_t) <= 4)) {
556 munmap(idx_map, idx_size);
557 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 558 }
2d88451b 559 }
1f688557 560
74e34e1f 561 p->index_version = version;
42873078
NP
562 p->index_data = idx_map;
563 p->index_size = idx_size;
57059091 564 p->num_objects = nr;
1f688557
JH
565 return 0;
566}
567
bc8e478a 568int open_pack_index(struct packed_git *p)
d079837e
SP
569{
570 char *idx_name;
571 int ret;
572
573 if (p->index_data)
574 return 0;
575
576 idx_name = xstrdup(p->pack_name);
577 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
578 ret = check_packed_git_idx(idx_name, p);
579 free(idx_name);
580 return ret;
581}
582
11daf39b
SP
583static void scan_windows(struct packed_git *p,
584 struct packed_git **lru_p,
585 struct pack_window **lru_w,
586 struct pack_window **lru_l)
1f688557 587{
11daf39b
SP
588 struct pack_window *w, *w_l;
589
590 for (w_l = NULL, w = p->windows; w; w = w->next) {
591 if (!w->inuse_cnt) {
592 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
593 *lru_p = p;
594 *lru_w = w;
595 *lru_l = w_l;
54044bf8 596 }
54044bf8 597 }
11daf39b 598 w_l = w;
f9253394 599 }
11daf39b
SP
600}
601
d1efefa4 602static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
603{
604 struct packed_git *p, *lru_p = NULL;
605 struct pack_window *lru_w = NULL, *lru_l = NULL;
606
607 if (current)
608 scan_windows(current, &lru_p, &lru_w, &lru_l);
609 for (p = packed_git; p; p = p->next)
610 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
611 if (lru_p) {
612 munmap(lru_w->base, lru_w->len);
613 pack_mapped -= lru_w->len;
614 if (lru_l)
615 lru_l->next = lru_w->next;
616 else {
617 lru_p->windows = lru_w->next;
d1efefa4 618 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
619 close(lru_p->pack_fd);
620 lru_p->pack_fd = -1;
621 }
622 }
623 free(lru_w);
a53128b6 624 pack_open_windows--;
54044bf8
SP
625 return 1;
626 }
627 return 0;
f9253394
JH
628}
629
d1efefa4 630void release_pack_memory(size_t need, int fd)
97bfeb34
SP
631{
632 size_t cur = pack_mapped;
d1efefa4 633 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
634 ; /* nothing */
635}
636
c9ced051
SP
637void close_pack_windows(struct packed_git *p)
638{
639 while (p->windows) {
640 struct pack_window *w = p->windows;
641
642 if (w->inuse_cnt)
643 die("pack '%s' still has open windows to it",
644 p->pack_name);
645 munmap(w->base, w->len);
646 pack_mapped -= w->len;
647 pack_open_windows--;
648 p->windows = w->next;
649 free(w);
650 }
651}
652
03e79c88 653void unuse_pack(struct pack_window **w_cursor)
f9253394 654{
03e79c88
SP
655 struct pack_window *w = *w_cursor;
656 if (w) {
657 w->inuse_cnt--;
658 *w_cursor = NULL;
659 }
1f688557
JH
660}
661
3cf8b462
SP
662/*
663 * Do not call this directly as this leaks p->pack_fd on error return;
664 * call open_packed_git() instead.
665 */
666static int open_packed_git_1(struct packed_git *p)
1f688557 667{
9bc879c1
SP
668 struct stat st;
669 struct pack_header hdr;
670 unsigned char sha1[20];
671 unsigned char *idx_sha1;
2c039da8 672 long fd_flag;
9bc879c1 673
d079837e
SP
674 if (!p->index_data && open_pack_index(p))
675 return error("packfile %s index unavailable", p->pack_name);
676
9bc879c1
SP
677 p->pack_fd = open(p->pack_name, O_RDONLY);
678 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 679 return -1;
9bc879c1
SP
680
681 /* If we created the struct before we had the pack we lack size. */
bf592c50 682 if (!p->pack_size) {
bf592c50 683 if (!S_ISREG(st.st_mode))
072db278 684 return error("packfile %s not a regular file", p->pack_name);
bf592c50 685 p->pack_size = st.st_size;
9bc879c1 686 } else if (p->pack_size != st.st_size)
072db278 687 return error("packfile %s size changed", p->pack_name);
9bc879c1 688
2c039da8
JH
689 /* We leave these file descriptors open with sliding mmap;
690 * there is no point keeping them open across exec(), though.
691 */
692 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
693 if (fd_flag < 0)
072db278 694 return error("cannot determine file descriptor flags");
2c039da8
JH
695 fd_flag |= FD_CLOEXEC;
696 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 697 return error("cannot set FD_CLOEXEC");
2c039da8 698
9bc879c1 699 /* Verify we recognize this pack file format. */
e6e2bd62 700 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 701 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 702 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 703 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 704 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
705 return error("packfile %s is version %"PRIu32" and not"
706 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
707 p->pack_name, ntohl(hdr.hdr_version));
708
709 /* Verify the pack matches its index. */
57059091 710 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
711 return error("packfile %s claims to have %"PRIu32" objects"
712 " while index indicates %"PRIu32" objects",
57059091
NP
713 p->pack_name, ntohl(hdr.hdr_entries),
714 p->num_objects);
9bc879c1 715 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 716 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 717 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 718 return error("packfile %s signature is unavailable", p->pack_name);
42873078 719 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 720 if (hashcmp(sha1, idx_sha1))
072db278
SP
721 return error("packfile %s does not match index", p->pack_name);
722 return 0;
9bc879c1
SP
723}
724
3cf8b462
SP
725static int open_packed_git(struct packed_git *p)
726{
727 if (!open_packed_git_1(p))
728 return 0;
729 if (p->pack_fd != -1) {
730 close(p->pack_fd);
731 p->pack_fd = -1;
732 }
733 return -1;
734}
735
c4001d92 736static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
737{
738 /* We must promise at least 20 bytes (one hash) after the
739 * offset is available from this window, otherwise the offset
740 * is not actually in this window and a different window (which
741 * has that one hash excess) must be used. This is to support
742 * the object header and delta base parsing routines below.
743 */
744 off_t win_off = win->offset;
745 return win_off <= offset
746 && (offset + 20) <= (win_off + win->len);
747}
748
03e79c88
SP
749unsigned char* use_pack(struct packed_git *p,
750 struct pack_window **w_cursor,
c4001d92 751 off_t offset,
03e79c88 752 unsigned int *left)
9bc879c1 753{
60bb8b14 754 struct pack_window *win = *w_cursor;
03e79c88 755
072db278
SP
756 if (p->pack_fd == -1 && open_packed_git(p))
757 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
758
759 /* Since packfiles end in a hash of their content and its
760 * pointless to ask for an offset into the middle of that
761 * hash, and the in_window function above wouldn't match
762 * don't allow an offset too close to the end of the file.
763 */
764 if (offset > (p->pack_size - 20))
765 die("offset beyond end of packfile (truncated pack?)");
766
767 if (!win || !in_window(win, offset)) {
768 if (win)
769 win->inuse_cnt--;
770 for (win = p->windows; win; win = win->next) {
771 if (in_window(win, offset))
772 break;
773 }
774 if (!win) {
78a28df9 775 size_t window_align = packed_git_window_size / 2;
dc49cd76 776 off_t len;
60bb8b14 777 win = xcalloc(1, sizeof(*win));
78a28df9 778 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
779 len = p->pack_size - win->offset;
780 if (len > packed_git_window_size)
781 len = packed_git_window_size;
782 win->len = (size_t)len;
60bb8b14 783 pack_mapped += win->len;
11daf39b 784 while (packed_git_limit < pack_mapped
d1efefa4 785 && unuse_one_window(p, p->pack_fd))
60bb8b14 786 ; /* nothing */
c4712e45 787 win->base = xmmap(NULL, win->len,
60bb8b14
SP
788 PROT_READ, MAP_PRIVATE,
789 p->pack_fd, win->offset);
790 if (win->base == MAP_FAILED)
73b4e4be
SP
791 die("packfile %s cannot be mapped: %s",
792 p->pack_name,
793 strerror(errno));
a53128b6
SP
794 pack_mmap_calls++;
795 pack_open_windows++;
796 if (pack_mapped > peak_pack_mapped)
797 peak_pack_mapped = pack_mapped;
798 if (pack_open_windows > peak_pack_open_windows)
799 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
800 win->next = p->windows;
801 p->windows = win;
802 }
1f688557 803 }
03e79c88
SP
804 if (win != *w_cursor) {
805 win->last_used = pack_used_ctr++;
806 win->inuse_cnt++;
807 *w_cursor = win;
808 }
60bb8b14 809 offset -= win->offset;
03e79c88 810 if (left)
dc49cd76 811 *left = win->len - xsize_t(offset);
03e79c88 812 return win->base + offset;
1f688557
JH
813}
814
27d69a46
NP
815static struct packed_git *alloc_packed_git(int extra)
816{
817 struct packed_git *p = xmalloc(sizeof(*p) + extra);
818 memset(p, 0, sizeof(*p));
819 p->pack_fd = -1;
820 return p;
821}
822
42873078 823struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
824{
825 struct stat st;
27d69a46 826 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 827
42873078
NP
828 /*
829 * Make sure a corresponding .pack file exists and that
830 * the index looks sane.
831 */
832 path_len -= strlen(".idx");
27d69a46
NP
833 if (path_len < 1) {
834 free(p);
1f688557 835 return NULL;
27d69a46 836 }
42873078 837 memcpy(p->pack_name, path, path_len);
8d25931d
BC
838
839 strcpy(p->pack_name + path_len, ".keep");
840 if (!access(p->pack_name, F_OK))
841 p->pack_keep = 1;
842
42873078 843 strcpy(p->pack_name + path_len, ".pack");
d079837e 844 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 845 free(p);
1f688557
JH
846 return NULL;
847 }
42873078 848
1f688557
JH
849 /* ok, it looks sane as far as we can check without
850 * actually mapping the pack file.
851 */
1f688557 852 p->pack_size = st.st_size;
9d835df2 853 p->pack_local = local;
b867092f 854 p->mtime = st.st_mtime;
42873078
NP
855 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
856 hashclr(p->sha1);
1f688557
JH
857 return p;
858}
859
bf592c50 860struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e 861{
79c6dca4 862 const char *idx_path = sha1_pack_index_name(sha1);
42873078 863 const char *path = sha1_pack_name(sha1);
27d69a46 864 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 865
27d69a46
NP
866 strcpy(p->pack_name, path);
867 hashcpy(p->sha1, sha1);
42873078
NP
868 if (check_packed_git_idx(idx_path, p)) {
869 free(p);
bf592c50 870 return NULL;
42873078 871 }
bf592c50 872
bf592c50
DB
873 return p;
874}
875
876void install_packed_git(struct packed_git *pack)
877{
878 pack->next = packed_git;
879 packed_git = pack;
880}
881
9d835df2 882static void prepare_packed_git_one(char *objdir, int local)
1f688557 883{
9cb18f56
JM
884 /* Ensure that this buffer is large enough so that we can
885 append "/pack/" without clobbering the stack even if
886 strlen(objdir) were PATH_MAX. */
887 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
888 int len;
889 DIR *dir;
890 struct dirent *de;
891
892 sprintf(path, "%s/pack", objdir);
893 len = strlen(path);
894 dir = opendir(path);
b5b16990 895 if (!dir) {
26125f6b 896 if (errno != ENOENT)
bd2afde8 897 error("unable to open object pack directory: %s: %s",
26125f6b 898 path, strerror(errno));
1f688557 899 return;
b5b16990 900 }
1f688557
JH
901 path[len++] = '/';
902 while ((de = readdir(dir)) != NULL) {
903 int namelen = strlen(de->d_name);
904 struct packed_git *p;
905
5bb1cda5 906 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
907 continue;
908
9cb18f56
JM
909 if (len + namelen + 1 > sizeof(path))
910 continue;
911
54a15a8d 912 /* Don't reopen a pack we already have. */
1f688557 913 strcpy(path + len, de->d_name);
86f7780c
JK
914 for (p = packed_git; p; p = p->next) {
915 if (!memcmp(path, p->pack_name, len + namelen - 4))
916 break;
917 }
918 if (p)
919 continue;
54a15a8d
SP
920 /* See if it really is a valid .idx file with corresponding
921 * .pack file that we can map.
922 */
9d835df2 923 p = add_packed_git(path, len + namelen, local);
1f688557
JH
924 if (!p)
925 continue;
625e9421 926 install_packed_git(p);
1f688557 927 }
5b35bcd5 928 closedir(dir);
1f688557
JH
929}
930
b867092f
JH
931static int sort_pack(const void *a_, const void *b_)
932{
933 struct packed_git *a = *((struct packed_git **)a_);
934 struct packed_git *b = *((struct packed_git **)b_);
935 int st;
936
937 /*
938 * Local packs tend to contain objects specific to our
939 * variant of the project than remote ones. In addition,
940 * remote ones could be on a network mounted filesystem.
941 * Favor local ones for these reasons.
942 */
943 st = a->pack_local - b->pack_local;
944 if (st)
945 return -st;
946
947 /*
948 * Younger packs tend to contain more recent objects,
949 * and more recent objects tend to get accessed more
950 * often.
951 */
952 if (a->mtime < b->mtime)
953 return 1;
954 else if (a->mtime == b->mtime)
955 return 0;
956 return -1;
957}
958
959static void rearrange_packed_git(void)
960{
961 struct packed_git **ary, *p;
962 int i, n;
963
964 for (n = 0, p = packed_git; p; p = p->next)
965 n++;
966 if (n < 2)
967 return;
968
969 /* prepare an array of packed_git for easier sorting */
970 ary = xcalloc(n, sizeof(struct packed_git *));
971 for (n = 0, p = packed_git; p; p = p->next)
972 ary[n++] = p;
973
974 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
975
976 /* link them back again */
977 for (i = 0; i < n - 1; i++)
978 ary[i]->next = ary[i + 1];
979 ary[n - 1]->next = NULL;
980 packed_git = ary[0];
981
982 free(ary);
983}
984
637cdd9d 985static int prepare_packed_git_run_once = 0;
9a217f2a 986void prepare_packed_git(void)
1f688557 987{
d5a63b99 988 struct alternate_object_database *alt;
1f688557 989
637cdd9d 990 if (prepare_packed_git_run_once)
1f688557 991 return;
9d835df2 992 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 993 prepare_alt_odb();
d5a63b99 994 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 995 alt->name[-1] = 0;
9d835df2 996 prepare_packed_git_one(alt->base, 0);
1494e038 997 alt->name[-1] = '/';
1f688557 998 }
b867092f 999 rearrange_packed_git();
637cdd9d
JK
1000 prepare_packed_git_run_once = 1;
1001}
1002
fc04c412 1003void reprepare_packed_git(void)
637cdd9d 1004{
4b480c67 1005 discard_revindex();
637cdd9d
JK
1006 prepare_packed_git_run_once = 0;
1007 prepare_packed_git();
1f688557
JH
1008}
1009
8eca0b47
NP
1010static void mark_bad_packed_object(struct packed_git *p,
1011 const unsigned char *sha1)
1012{
1013 unsigned i;
1014 for (i = 0; i < p->num_bad_objects; i++)
1015 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1016 return;
1017 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1018 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1019 p->num_bad_objects++;
1020}
1021
ac939109
NP
1022static int has_packed_and_bad(const unsigned char *sha1)
1023{
1024 struct packed_git *p;
1025 unsigned i;
1026
1027 for (p = packed_git; p; p = p->next)
1028 for (i = 0; i < p->num_bad_objects; i++)
1029 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1030 return 1;
1031 return 0;
1032}
1033
5d6ccf5c 1034int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
1035{
1036 unsigned char real_sha1[20];
7cfb5f36 1037 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 1038 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1039}
1040
44d1c19e
LT
1041static int git_open_noatime(const char *name)
1042{
1043 static int sha1_file_open_flag = O_NOATIME;
1044 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1045
1046 /* Might the failure be due to O_NOATIME? */
1047 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1048 fd = open(name, O_RDONLY);
1049 if (fd >= 0)
1050 sha1_file_open_flag = 0;
1051 }
1052 return fd;
1053}
1054
1055static int open_sha1_file(const unsigned char *sha1)
1056{
1057 int fd;
1058 char *name = sha1_file_name(sha1);
1059 struct alternate_object_database *alt;
1060
1061 fd = git_open_noatime(name);
1062 if (fd >= 0)
1063 return fd;
1064
1065 prepare_alt_odb();
1066 errno = ENOENT;
1067 for (alt = alt_odb_list; alt; alt = alt->next) {
1068 name = alt->name;
1069 fill_sha1_path(name, sha1);
1070 fd = git_open_noatime(alt->base);
1071 if (fd >= 0)
1072 return fd;
1073 }
1074 return -1;
1075}
1076
4175e9e3 1077static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1078{
0fcfd160 1079 void *map;
144bde78 1080 int fd;
ace1534d 1081
44d1c19e
LT
1082 fd = open_sha1_file(sha1);
1083 map = NULL;
1084 if (fd >= 0) {
1085 struct stat st;
0fcfd160 1086
44d1c19e
LT
1087 if (!fstat(fd, &st)) {
1088 *size = xsize_t(st.st_size);
1089 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1090 }
44d1c19e 1091 close(fd);
0fcfd160 1092 }
0fcfd160
LT
1093 return map;
1094}
1095
726f852b 1096static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1097{
1098 unsigned int word;
1099
1100 /*
1101 * Is it a zlib-compressed buffer? If so, the first byte
1102 * must be 0x78 (15-bit window size, deflated), and the
1103 * first 16-bit word is evenly divisible by 31
1104 */
1105 word = (map[0] << 8) + map[1];
1106 if (map[0] == 0x78 && !(word % 31))
1107 return 1;
1108 else
1109 return 0;
1110}
1111
72518e9c 1112unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1113{
ad1ed5ee 1114 unsigned shift;
93821bd9 1115 unsigned char c;
93821bd9 1116 unsigned long size;
ad1ed5ee
JH
1117 unsigned long used = 0;
1118
1119 c = buf[used++];
1120 *type = (c >> 4) & 7;
1121 size = c & 15;
1122 shift = 4;
1123 while (c & 0x80) {
1124 if (len <= used)
1125 return 0;
1126 if (sizeof(long) * 8 <= shift)
1127 return 0;
1128 c = buf[used++];
1129 size += (c & 0x7f) << shift;
1130 shift += 7;
1131 }
1132 *sizep = size;
1133 return used;
1134}
1135
1136static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1137{
1138 unsigned long size, used;
1139 static const char valid_loose_object_type[8] = {
1140 0, /* OBJ_EXT */
1141 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1142 0, /* "delta" and others are invalid in a loose object */
93821bd9 1143 };
ad1ed5ee 1144 enum object_type type;
93821bd9 1145
c4483576
LT
1146 /* Get the data stream */
1147 memset(stream, 0, sizeof(*stream));
1148 stream->next_in = map;
1149 stream->avail_in = mapsize;
1150 stream->next_out = buffer;
93821bd9
LT
1151 stream->avail_out = bufsiz;
1152
bb6b8e4f 1153 if (legacy_loose_object(map)) {
93821bd9
LT
1154 inflateInit(stream);
1155 return inflate(stream, 0);
1156 }
1157
726f852b
NP
1158
1159 /*
1160 * There used to be a second loose object header format which
1161 * was meant to mimic the in-pack format, allowing for direct
1162 * copy of the object data. This format turned up not to be
1163 * really worth it and we don't write it any longer. But we
1164 * can still read it.
1165 */
ad1ed5ee
JH
1166 used = unpack_object_header_gently(map, mapsize, &type, &size);
1167 if (!used || !valid_loose_object_type[type])
93821bd9 1168 return -1;
ad1ed5ee
JH
1169 map += used;
1170 mapsize -= used;
93821bd9
LT
1171
1172 /* Set up the stream for the rest.. */
1173 stream->next_in = map;
1174 stream->avail_in = mapsize;
c4483576 1175 inflateInit(stream);
93821bd9
LT
1176
1177 /* And generate the fake traditional header */
ad1ed5ee 1178 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1179 typename(type), size);
93821bd9 1180 return 0;
c4483576
LT
1181}
1182
7efbff75 1183static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1184{
1185 int bytes = strlen(buffer) + 1;
d565b341 1186 unsigned char *buf = xmalloc(1+size);
93821bd9 1187 unsigned long n;
7efbff75 1188 int status = Z_OK;
5180cacc 1189
93821bd9
LT
1190 n = stream->total_out - bytes;
1191 if (n > size)
1192 n = size;
1193 memcpy(buf, (char *) buffer + bytes, n);
1194 bytes = n;
456cdf6e
LT
1195 if (bytes <= size) {
1196 /*
1197 * The above condition must be (bytes <= size), not
1198 * (bytes < size). In other words, even though we
1199 * expect no more output and set avail_out to zer0,
1200 * the input zlib stream may have bytes that express
1201 * "this concludes the stream", and we *do* want to
1202 * eat that input.
1203 *
1204 * Otherwise we would not be able to test that we
1205 * consumed all the input to reach the expected size;
1206 * we also want to check that zlib tells us that all
1207 * went well with status == Z_STREAM_END at the end.
1208 */
5180cacc
LT
1209 stream->next_out = buf + bytes;
1210 stream->avail_out = size - bytes;
7efbff75
JH
1211 while (status == Z_OK)
1212 status = inflate(stream, Z_FINISH);
5180cacc
LT
1213 }
1214 buf[size] = 0;
456cdf6e 1215 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1216 inflateEnd(stream);
1217 return buf;
1218 }
1219
1220 if (status < 0)
1221 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1222 else if (stream->avail_in)
1223 error("garbage at end of loose object '%s'",
1224 sha1_to_hex(sha1));
1225 free(buf);
1226 return NULL;
5180cacc
LT
1227}
1228
1229/*
1230 * We used to just use "sscanf()", but that's actually way
1231 * too permissive for what we want to check. So do an anal
1232 * object header parse by hand.
1233 */
21666f1a 1234static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1235{
21666f1a 1236 char type[10];
5180cacc
LT
1237 int i;
1238 unsigned long size;
1239
1240 /*
a6080a0a 1241 * The type can be at most ten bytes (including the
5180cacc 1242 * terminating '\0' that we add), and is followed by
21666f1a 1243 * a space.
5180cacc 1244 */
21666f1a 1245 i = 0;
5180cacc
LT
1246 for (;;) {
1247 char c = *hdr++;
1248 if (c == ' ')
1249 break;
21666f1a
NP
1250 type[i++] = c;
1251 if (i >= sizeof(type))
5180cacc 1252 return -1;
5180cacc 1253 }
21666f1a 1254 type[i] = 0;
5180cacc
LT
1255
1256 /*
1257 * The length must follow immediately, and be in canonical
1258 * decimal format (ie "010" is not valid).
1259 */
1260 size = *hdr++ - '0';
1261 if (size > 9)
1262 return -1;
1263 if (size) {
1264 for (;;) {
1265 unsigned long c = *hdr - '0';
1266 if (c > 9)
1267 break;
1268 hdr++;
1269 size = size * 10 + c;
1270 }
1271 }
1272 *sizep = size;
1273
1274 /*
1275 * The length must be followed by a zero byte
1276 */
21666f1a 1277 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1278}
1279
7efbff75 1280static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1281{
5180cacc 1282 int ret;
0fcfd160 1283 z_stream stream;
5180cacc 1284 char hdr[8192];
0fcfd160 1285
5180cacc 1286 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1287 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1288 return NULL;
1289
7efbff75 1290 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1291}
1292
54dab52a
NP
1293unsigned long get_size_from_delta(struct packed_git *p,
1294 struct pack_window **w_curs,
1295 off_t curpos)
1296{
1297 const unsigned char *data;
1298 unsigned char delta_head[20], *in;
1299 z_stream stream;
1300 int st;
1301
1302 memset(&stream, 0, sizeof(stream));
1303 stream.next_out = delta_head;
1304 stream.avail_out = sizeof(delta_head);
1305
1306 inflateInit(&stream);
1307 do {
1308 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1309 stream.next_in = in;
1310 st = inflate(&stream, Z_FINISH);
1311 curpos += stream.next_in - in;
1312 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1313 stream.total_out < sizeof(delta_head));
1314 inflateEnd(&stream);
1315 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1316 die("delta data unpack-initial failed");
1317
1318 /* Examine the initial part of the delta to figure out
1319 * the result size.
1320 */
1321 data = delta_head;
1322
1323 /* ignore base size */
1324 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1325
1326 /* Read the result size */
1327 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1328}
1329
c4001d92 1330static off_t get_delta_base(struct packed_git *p,
03e79c88 1331 struct pack_window **w_curs,
c4001d92 1332 off_t *curpos,
21666f1a 1333 enum object_type type,
c4001d92 1334 off_t delta_obj_offset)
eb32d236 1335{
2b87c45b 1336 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1337 off_t base_offset;
eb32d236 1338
8d8a4ea5
SP
1339 /* use_pack() assured us we have [base_info, base_info + 20)
1340 * as a range that we can look at without walking off the
1341 * end of the mapped window. Its actually the hash size
1342 * that is assured. An OFS_DELTA longer than the hash size
1343 * is stupid, as then a REF_DELTA would be smaller to store.
1344 */
21666f1a 1345 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1346 unsigned used = 0;
1347 unsigned char c = base_info[used++];
1348 base_offset = c & 127;
1349 while (c & 128) {
1350 base_offset += 1;
8723f216 1351 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1352 return 0; /* overflow */
eb32d236
NP
1353 c = base_info[used++];
1354 base_offset = (base_offset << 7) + (c & 127);
1355 }
1356 base_offset = delta_obj_offset - base_offset;
1357 if (base_offset >= delta_obj_offset)
8eca0b47 1358 return 0; /* out of bound */
2b87c45b 1359 *curpos += used;
21666f1a 1360 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1361 /* The base entry _must_ be in the same pack */
1362 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1363 *curpos += 20;
eb32d236
NP
1364 } else
1365 die("I am totally screwed");
2b87c45b 1366 return base_offset;
eb32d236
NP
1367}
1368
f3bf9224 1369/* forward declaration for a mutually recursive function */
c4001d92 1370static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1371 unsigned long *sizep);
f3bf9224 1372
43057304 1373static int packed_delta_info(struct packed_git *p,
03e79c88 1374 struct pack_window **w_curs,
c4001d92 1375 off_t curpos,
21666f1a 1376 enum object_type type,
c4001d92 1377 off_t obj_offset,
43057304 1378 unsigned long *sizep)
5db47c2b 1379{
c4001d92 1380 off_t base_offset;
f3bf9224 1381
21666f1a
NP
1382 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1383 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1384
c62266f3
JH
1385 /* We choose to only get the type of the base object and
1386 * ignore potentially corrupt pack file that expects the delta
1387 * based on a base with a wrong size. This saves tons of
1388 * inflate() calls.
1389 */
54dab52a
NP
1390 if (sizep)
1391 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1392
1393 return type;
5db47c2b
JH
1394}
1395
2b87c45b
NP
1396static int unpack_object_header(struct packed_git *p,
1397 struct pack_window **w_curs,
c4001d92 1398 off_t *curpos,
2b87c45b 1399 unsigned long *sizep)
a733cb60 1400{
03e79c88
SP
1401 unsigned char *base;
1402 unsigned int left;
ad1ed5ee 1403 unsigned long used;
2b87c45b 1404 enum object_type type;
a733cb60 1405
8d8a4ea5
SP
1406 /* use_pack() assures us we have [base, base + 20) available
1407 * as a range that we can look at at. (Its actually the hash
3dff5379 1408 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1409 * the maximum deflated object size is 2^137, which is just
1410 * insane, so we know won't exceed what we have been given.
1411 */
2b87c45b
NP
1412 base = use_pack(p, w_curs, *curpos, &left);
1413 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1414 if (!used)
1415 die("object offset outside of pack file");
2b87c45b 1416 *curpos += used;
ad1ed5ee 1417
2b87c45b 1418 return type;
a733cb60
LT
1419}
1420
21666f1a 1421const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1422 off_t obj_offset,
21666f1a
NP
1423 unsigned long *size,
1424 unsigned long *store_size,
1425 unsigned int *delta_chain_length,
1426 unsigned char *base_sha1)
ad8c80a5 1427{
03e79c88 1428 struct pack_window *w_curs = NULL;
c4001d92
SP
1429 off_t curpos;
1430 unsigned long dummy;
43057304 1431 unsigned char *next_sha1;
21666f1a 1432 enum object_type type;
70f5d5d3 1433 struct revindex_entry *revidx;
ad8c80a5 1434
43057304 1435 *delta_chain_length = 0;
2b87c45b 1436 curpos = obj_offset;
21666f1a 1437 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304 1438
70f5d5d3
NP
1439 revidx = find_pack_revindex(p, obj_offset);
1440 *store_size = revidx[1].offset - obj_offset;
1441
43057304 1442 for (;;) {
21666f1a 1443 switch (type) {
43057304 1444 default:
08a19d87 1445 die("pack %s contains unknown object type %d",
21666f1a 1446 p->pack_name, type);
43057304
NP
1447 case OBJ_COMMIT:
1448 case OBJ_TREE:
1449 case OBJ_BLOB:
1450 case OBJ_TAG:
03e79c88 1451 unuse_pack(&w_curs);
21666f1a 1452 return typename(type);
eb32d236 1453 case OBJ_OFS_DELTA:
21666f1a 1454 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
8eca0b47
NP
1455 if (!obj_offset)
1456 die("pack %s contains bad delta base reference of type %s",
1457 p->pack_name, typename(type));
eb32d236 1458 if (*delta_chain_length == 0) {
70f5d5d3
NP
1459 revidx = find_pack_revindex(p, obj_offset);
1460 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
eb32d236
NP
1461 }
1462 break;
1463 case OBJ_REF_DELTA:
2b87c45b 1464 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1465 if (*delta_chain_length == 0)
1466 hashcpy(base_sha1, next_sha1);
2b87c45b 1467 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1468 break;
1469 }
43057304 1470 (*delta_chain_length)++;
2b87c45b 1471 curpos = obj_offset;
21666f1a 1472 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1473 }
ad8c80a5
JH
1474}
1475
c4001d92 1476static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1477 unsigned long *sizep)
1f688557 1478{
03e79c88 1479 struct pack_window *w_curs = NULL;
c4001d92
SP
1480 unsigned long size;
1481 off_t curpos = obj_offset;
21666f1a 1482 enum object_type type;
5db47c2b 1483
21666f1a 1484 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1485
21666f1a 1486 switch (type) {
eb32d236
NP
1487 case OBJ_OFS_DELTA:
1488 case OBJ_REF_DELTA:
21666f1a
NP
1489 type = packed_delta_info(p, &w_curs, curpos,
1490 type, obj_offset, sizep);
2b87c45b 1491 break;
a733cb60 1492 case OBJ_COMMIT:
a733cb60 1493 case OBJ_TREE:
a733cb60 1494 case OBJ_BLOB:
a733cb60 1495 case OBJ_TAG:
2b87c45b
NP
1496 if (sizep)
1497 *sizep = size;
a69d0943 1498 break;
1f688557 1499 default:
08a19d87 1500 die("pack %s contains unknown object type %d",
21666f1a 1501 p->pack_name, type);
1f688557 1502 }
2b87c45b 1503 unuse_pack(&w_curs);
21666f1a 1504 return type;
1f688557
JH
1505}
1506
eb950c19 1507static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1508 struct pack_window **w_curs,
c4001d92 1509 off_t curpos,
eb950c19 1510 unsigned long size)
de530aaa
SP
1511{
1512 int st;
1513 z_stream stream;
079afb18 1514 unsigned char *buffer, *in;
de530aaa
SP
1515
1516 buffer = xmalloc(size + 1);
1517 buffer[size] = 0;
1518 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1519 stream.next_out = buffer;
1520 stream.avail_out = size;
1521
1522 inflateInit(&stream);
079afb18 1523 do {
2b87c45b 1524 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1525 stream.next_in = in;
1526 st = inflate(&stream, Z_FINISH);
2b87c45b 1527 curpos += stream.next_in - in;
079afb18 1528 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1529 inflateEnd(&stream);
1530 if ((st != Z_STREAM_END) || stream.total_out != size) {
1531 free(buffer);
1532 return NULL;
1533 }
1534
1535 return buffer;
1536}
1537
e5e01619
LT
1538#define MAX_DELTA_CACHE (256)
1539
18bdec11 1540static size_t delta_base_cached;
5e08ecbf
NP
1541
1542static struct delta_base_cache_lru_list {
1543 struct delta_base_cache_lru_list *prev;
1544 struct delta_base_cache_lru_list *next;
1545} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1546
e5e01619 1547static struct delta_base_cache_entry {
5e08ecbf
NP
1548 struct delta_base_cache_lru_list lru;
1549 void *data;
e5e01619
LT
1550 struct packed_git *p;
1551 off_t base_offset;
1552 unsigned long size;
e5e01619
LT
1553 enum object_type type;
1554} delta_base_cache[MAX_DELTA_CACHE];
1555
1556static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1557{
1558 unsigned long hash;
1559
1560 hash = (unsigned long)p + (unsigned long)base_offset;
1561 hash += (hash >> 8) + (hash >> 16);
3358004a 1562 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1563}
1564
62f255ad 1565static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1566 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1567{
e5e01619
LT
1568 void *ret;
1569 unsigned long hash = pack_entry_hash(p, base_offset);
1570 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1571
1572 ret = ent->data;
1573 if (ret && ent->p == p && ent->base_offset == base_offset)
1574 goto found_cache_entry;
62f255ad 1575 return unpack_entry(p, base_offset, type, base_size);
e5e01619
LT
1576
1577found_cache_entry:
18bdec11 1578 if (!keep_cache) {
a0cba108 1579 ent->data = NULL;
5e08ecbf
NP
1580 ent->lru.next->prev = ent->lru.prev;
1581 ent->lru.prev->next = ent->lru.next;
18bdec11 1582 delta_base_cached -= ent->size;
182af834
PH
1583 } else {
1584 ret = xmemdupz(ent->data, ent->size);
a0cba108 1585 }
e5e01619
LT
1586 *type = ent->type;
1587 *base_size = ent->size;
1588 return ret;
62f255ad
LT
1589}
1590
18bdec11
SP
1591static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1592{
1593 if (ent->data) {
1594 free(ent->data);
1595 ent->data = NULL;
5e08ecbf
NP
1596 ent->lru.next->prev = ent->lru.prev;
1597 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1598 delta_base_cached -= ent->size;
1599 }
1600}
1601
62f255ad
LT
1602static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1603 void *base, unsigned long base_size, enum object_type type)
1604{
5e08ecbf 1605 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1606 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1607 struct delta_base_cache_lru_list *lru;
e5e01619 1608
18bdec11
SP
1609 release_delta_base_cache(ent);
1610 delta_base_cached += base_size;
5e08ecbf
NP
1611
1612 for (lru = delta_base_cache_lru.next;
1613 delta_base_cached > delta_base_cache_limit
1614 && lru != &delta_base_cache_lru;
1615 lru = lru->next) {
1616 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1617 if (f->type == OBJ_BLOB)
1618 release_delta_base_cache(f);
1619 }
5e08ecbf
NP
1620 for (lru = delta_base_cache_lru.next;
1621 delta_base_cached > delta_base_cache_limit
1622 && lru != &delta_base_cache_lru;
1623 lru = lru->next) {
1624 struct delta_base_cache_entry *f = (void *)lru;
1625 release_delta_base_cache(f);
1626 }
18bdec11 1627
e5e01619
LT
1628 ent->p = p;
1629 ent->base_offset = base_offset;
1630 ent->type = type;
1631 ent->data = base;
1632 ent->size = base_size;
5e08ecbf
NP
1633 ent->lru.next = &delta_base_cache_lru;
1634 ent->lru.prev = delta_base_cache_lru.prev;
1635 delta_base_cache_lru.prev->next = &ent->lru;
1636 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1637}
1638
eb950c19 1639static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1640 struct pack_window **w_curs,
c4001d92 1641 off_t curpos,
1f688557 1642 unsigned long delta_size,
c4001d92 1643 off_t obj_offset,
21666f1a 1644 enum object_type *type,
eb950c19 1645 unsigned long *sizep)
1f688557 1646{
7c3e8be3 1647 void *delta_data, *result, *base;
c4001d92
SP
1648 unsigned long base_size;
1649 off_t base_offset;
43057304 1650
21666f1a 1651 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
8eca0b47
NP
1652 if (!base_offset) {
1653 error("failed to validate delta base reference "
1654 "at offset %"PRIuMAX" from %s",
1655 (uintmax_t)curpos, p->pack_name);
1656 return NULL;
1657 }
eac12e2d 1658 unuse_pack(w_curs);
a0cba108 1659 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
8eca0b47
NP
1660 if (!base) {
1661 /*
1662 * We're probably in deep shit, but let's try to fetch
1663 * the required base anyway from another pack or loose.
1664 * This is costly but should happen only in the presence
1665 * of a corrupted pack, and is better than failing outright.
1666 */
1667 struct revindex_entry *revidx = find_pack_revindex(p, base_offset);
1668 const unsigned char *base_sha1 =
1669 nth_packed_object_sha1(p, revidx->nr);
1670 error("failed to read delta base object %s"
1671 " at offset %"PRIuMAX" from %s",
1672 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1673 p->pack_name);
1674 mark_bad_packed_object(p, base_sha1);
ac939109 1675 base = read_object(base_sha1, type, &base_size);
8eca0b47
NP
1676 if (!base)
1677 return NULL;
1678 }
67686d95 1679
2b87c45b 1680 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
8eca0b47
NP
1681 if (!delta_data) {
1682 error("failed to unpack compressed delta "
1683 "at offset %"PRIuMAX" from %s",
1684 (uintmax_t)curpos, p->pack_name);
1685 free(base);
1686 return NULL;
1687 }
1f688557
JH
1688 result = patch_delta(base, base_size,
1689 delta_data, delta_size,
21666f1a 1690 sizep);
1f688557
JH
1691 if (!result)
1692 die("failed to apply delta");
1693 free(delta_data);
62f255ad 1694 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1695 return result;
1696}
1697
c4001d92 1698void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1699 enum object_type *type, unsigned long *sizep)
1f688557 1700{
03e79c88 1701 struct pack_window *w_curs = NULL;
c4001d92 1702 off_t curpos = obj_offset;
21666f1a 1703 void *data;
1f688557 1704
21666f1a
NP
1705 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1706 switch (*type) {
eb32d236
NP
1707 case OBJ_OFS_DELTA:
1708 case OBJ_REF_DELTA:
21666f1a
NP
1709 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1710 obj_offset, type, sizep);
4d703a1a 1711 break;
a733cb60 1712 case OBJ_COMMIT:
a733cb60 1713 case OBJ_TREE:
a733cb60 1714 case OBJ_BLOB:
a733cb60 1715 case OBJ_TAG:
21666f1a 1716 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1717 break;
1f688557 1718 default:
8eca0b47
NP
1719 data = NULL;
1720 error("unknown object type %i at offset %"PRIuMAX" in %s",
1721 *type, (uintmax_t)obj_offset, p->pack_name);
1f688557 1722 }
03e79c88 1723 unuse_pack(&w_curs);
21666f1a 1724 return data;
1f688557
JH
1725}
1726
d079837e 1727const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1728 uint32_t n)
9a217f2a 1729{
42873078 1730 const unsigned char *index = p->index_data;
d079837e
SP
1731 if (!index) {
1732 if (open_pack_index(p))
1733 return NULL;
1734 index = p->index_data;
1735 }
57059091 1736 if (n >= p->num_objects)
d72308e0 1737 return NULL;
74e34e1f
NP
1738 index += 4 * 256;
1739 if (p->index_version == 1) {
1740 return index + 24 * n + 4;
1741 } else {
1742 index += 8;
1743 return index + 20 * n;
1744 }
1745}
1746
99093238 1747off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
1748{
1749 const unsigned char *index = p->index_data;
1750 index += 4 * 256;
1751 if (p->index_version == 1) {
1752 return ntohl(*((uint32_t *)(index + 24 * n)));
1753 } else {
1754 uint32_t off;
1755 index += 8 + p->num_objects * (20 + 4);
1756 off = ntohl(*((uint32_t *)(index + 4 * n)));
1757 if (!(off & 0x80000000))
1758 return off;
1759 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1760 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1761 ntohl(*((uint32_t *)(index + 4)));
1762 }
9a217f2a
JH
1763}
1764
c4001d92 1765off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1766 struct packed_git *p)
1f688557 1767{
42873078 1768 const uint32_t *level1_ofs = p->index_data;
42873078 1769 const unsigned char *index = p->index_data;
628522ec
JH
1770 unsigned hi, lo, stride;
1771 static int use_lookup = -1;
1772 static int debug_lookup = -1;
1773
1774 if (debug_lookup < 0)
1775 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1776
d079837e
SP
1777 if (!index) {
1778 if (open_pack_index(p))
1779 return 0;
1780 level1_ofs = p->index_data;
1781 index = p->index_data;
1782 }
74e34e1f
NP
1783 if (p->index_version > 1) {
1784 level1_ofs += 2;
1785 index += 8;
1786 }
42873078 1787 index += 4 * 256;
74e34e1f
NP
1788 hi = ntohl(level1_ofs[*sha1]);
1789 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
1790 if (p->index_version > 1) {
1791 stride = 20;
1792 } else {
1793 stride = 24;
1794 index += 4;
1795 }
1796
1797 if (debug_lookup)
6e1c2344 1798 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
1799 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1800
1801 if (use_lookup < 0)
1802 use_lookup = !!getenv("GIT_USE_LOOKUP");
1803 if (use_lookup) {
1804 int pos = sha1_entry_pos(index, stride, 0,
1805 lo, hi, p->num_objects, sha1);
1806 if (pos < 0)
1807 return 0;
1808 return nth_packed_object_offset(p, pos);
1809 }
1f688557
JH
1810
1811 do {
74e34e1f 1812 unsigned mi = (lo + hi) / 2;
628522ec
JH
1813 int cmp = hashcmp(index + mi * stride, sha1);
1814
1815 if (debug_lookup)
1816 printf("lo %u hi %u rg %u mi %u\n",
1817 lo, hi, hi - lo, mi);
43057304 1818 if (!cmp)
74e34e1f 1819 return nth_packed_object_offset(p, mi);
1f688557
JH
1820 if (cmp > 0)
1821 hi = mi;
1822 else
1823 lo = mi+1;
1824 } while (lo < hi);
1825 return 0;
1826}
1827
000dfd3f 1828int matches_pack_name(struct packed_git *p, const char *name)
d4ff6d92
SP
1829{
1830 const char *last_c, *c;
1831
000dfd3f
JH
1832 if (!strcmp(p->pack_name, name))
1833 return 1;
d4ff6d92
SP
1834
1835 for (c = p->pack_name, last_c = c; *c;)
1836 if (*c == '/')
1837 last_c = ++c;
1838 else
1839 ++c;
000dfd3f
JH
1840 if (!strcmp(last_c, name))
1841 return 1;
d4ff6d92 1842
000dfd3f 1843 return 0;
d4ff6d92
SP
1844}
1845
106d710b 1846static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1847{
f7c22cc6 1848 static struct packed_git *last_found = (void *)1;
1f688557 1849 struct packed_git *p;
c4001d92 1850 off_t offset;
43057304 1851
1f688557 1852 prepare_packed_git();
f7c22cc6
NP
1853 if (!packed_git)
1854 return 0;
1855 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1856
f7c22cc6 1857 do {
106d710b
JH
1858 if (ignore_packed) {
1859 const char **ig;
1860 for (ig = ignore_packed; *ig; ig++)
000dfd3f 1861 if (matches_pack_name(p, *ig))
106d710b
JH
1862 break;
1863 if (*ig)
f7c22cc6 1864 goto next;
106d710b 1865 }
f7c22cc6 1866
8eca0b47
NP
1867 if (p->num_bad_objects) {
1868 unsigned i;
1869 for (i = 0; i < p->num_bad_objects; i++)
1870 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1871 goto next;
1872 }
1873
43057304
NP
1874 offset = find_pack_entry_one(sha1, p);
1875 if (offset) {
c715f783
SP
1876 /*
1877 * We are about to tell the caller where they can
1878 * locate the requested object. We better make
1879 * sure the packfile is still here and can be
1880 * accessed before supplying that answer, as
1881 * it may have been deleted since the index
1882 * was loaded!
1883 */
1884 if (p->pack_fd == -1 && open_packed_git(p)) {
1885 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1886 goto next;
c715f783 1887 }
43057304
NP
1888 e->offset = offset;
1889 e->p = p;
1890 hashcpy(e->sha1, sha1);
f7c22cc6 1891 last_found = p;
1f688557 1892 return 1;
43057304 1893 }
f7c22cc6
NP
1894
1895 next:
1896 if (p == last_found)
1897 p = packed_git;
1898 else
1899 p = p->next;
1900 if (p == last_found)
1901 p = p->next;
1902 } while (p);
1f688557
JH
1903 return 0;
1904}
1905
a6080a0a 1906struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1907 struct packed_git *packs)
1908{
1909 struct packed_git *p;
bf592c50
DB
1910
1911 for (p = packs; p; p = p->next) {
43057304 1912 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1913 return p;
1914 }
1915 return NULL;
21666f1a 1916
bf592c50
DB
1917}
1918
21666f1a 1919static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1920{
36e4d74a 1921 int status;
65c2e0c3
JH
1922 unsigned long mapsize, size;
1923 void *map;
1924 z_stream stream;
d65a16f6 1925 char hdr[32];
65c2e0c3 1926
bb6b8e4f 1927 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1928 if (!map)
1929 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1930 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1931 status = error("unable to unpack %s header",
1932 sha1_to_hex(sha1));
21666f1a 1933 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1934 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1935 else if (sizep)
1936 *sizep = size;
65c2e0c3
JH
1937 inflateEnd(&stream);
1938 munmap(map, mapsize);
1939 return status;
1940}
1941
21666f1a 1942int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1943{
f0df4ed5 1944 struct pack_entry e;
ddd63e64 1945 int status;
f0df4ed5
JS
1946
1947 if (!find_pack_entry(sha1, &e, NULL)) {
ddd63e64
SG
1948 /* Most likely it's a loose object. */
1949 status = sha1_loose_object_info(sha1, sizep);
1950 if (status >= 0)
1951 return status;
1952
1953 /* Not a loose object; someone else may have just packed it. */
f0df4ed5
JS
1954 reprepare_packed_git();
1955 if (!find_pack_entry(sha1, &e, NULL))
ddd63e64 1956 return status;
f0df4ed5 1957 }
21666f1a 1958 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1959}
1960
21666f1a
NP
1961static void *read_packed_sha1(const unsigned char *sha1,
1962 enum object_type *type, unsigned long *size)
1f688557
JH
1963{
1964 struct pack_entry e;
8eca0b47 1965 void *data;
1f688557 1966
8276c007 1967 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1968 return NULL;
8eca0b47
NP
1969 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1970 if (!data) {
1971 /*
1972 * We're probably in deep shit, but let's try to fetch
1973 * the required object anyway from another pack or loose.
1974 * This should happen only in the presence of a corrupted
1975 * pack, and is better than failing outright.
1976 */
1977 error("failed to read object %s at offset %"PRIuMAX" from %s",
1978 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1979 mark_bad_packed_object(e.p, sha1);
ac939109 1980 data = read_object(sha1, type, size);
8eca0b47
NP
1981 }
1982 return data;
1f688557
JH
1983}
1984
d66b37bb
JH
1985/*
1986 * This is meant to hold a *small* number of objects that you would
1987 * want read_sha1_file() to be able to return, but yet you do not want
1988 * to write them into the object store (e.g. a browse-only
1989 * application).
1990 */
1991static struct cached_object {
1992 unsigned char sha1[20];
21666f1a 1993 enum object_type type;
d66b37bb
JH
1994 void *buf;
1995 unsigned long size;
1996} *cached_objects;
1997static int cached_object_nr, cached_object_alloc;
1998
346245a1
JK
1999static struct cached_object empty_tree = {
2000 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
2001 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
2002 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
2003 OBJ_TREE,
2004 "",
2005 0
2006};
2007
d66b37bb
JH
2008static struct cached_object *find_cached_object(const unsigned char *sha1)
2009{
2010 int i;
2011 struct cached_object *co = cached_objects;
2012
2013 for (i = 0; i < cached_object_nr; i++, co++) {
2014 if (!hashcmp(co->sha1, sha1))
2015 return co;
2016 }
346245a1
JK
2017 if (!hashcmp(sha1, empty_tree.sha1))
2018 return &empty_tree;
d66b37bb
JH
2019 return NULL;
2020}
2021
21666f1a
NP
2022int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2023 unsigned char *sha1)
d66b37bb
JH
2024{
2025 struct cached_object *co;
2026
21666f1a 2027 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2028 if (has_sha1_file(sha1) || find_cached_object(sha1))
2029 return 0;
2030 if (cached_object_alloc <= cached_object_nr) {
2031 cached_object_alloc = alloc_nr(cached_object_alloc);
2032 cached_objects = xrealloc(cached_objects,
2033 sizeof(*cached_objects) *
2034 cached_object_alloc);
2035 }
2036 co = &cached_objects[cached_object_nr++];
2037 co->size = len;
21666f1a 2038 co->type = type;
efa13f7b
JH
2039 co->buf = xmalloc(len);
2040 memcpy(co->buf, buf, len);
d66b37bb
JH
2041 hashcpy(co->sha1, sha1);
2042 return 0;
2043}
2044
ac939109
NP
2045void *read_object(const unsigned char *sha1, enum object_type *type,
2046 unsigned long *size)
0fcfd160
LT
2047{
2048 unsigned long mapsize;
2049 void *map, *buf;
d66b37bb
JH
2050 struct cached_object *co;
2051
2052 co = find_cached_object(sha1);
2053 if (co) {
21666f1a 2054 *type = co->type;
d66b37bb 2055 *size = co->size;
182af834 2056 return xmemdupz(co->buf, co->size);
d66b37bb 2057 }
0fcfd160 2058
8276c007
PE
2059 buf = read_packed_sha1(sha1, type, size);
2060 if (buf)
2061 return buf;
bb6b8e4f 2062 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2063 if (map) {
7efbff75 2064 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2065 munmap(map, mapsize);
2066 return buf;
2067 }
637cdd9d 2068 reprepare_packed_git();
8276c007 2069 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2070}
2071
ac939109
NP
2072void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
2073 unsigned long *size)
2074{
2075 void *data = read_object(sha1, type, size);
2076 /* legacy behavior is to die on corrupted objects */
2077 if (!data && (has_loose_object(sha1) || has_packed_and_bad(sha1)))
2078 die("object %s is corrupted", sha1_to_hex(sha1));
2079 return data;
2080}
2081
40469ee9 2082void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2083 const char *required_type_name,
40469ee9
JH
2084 unsigned long *size,
2085 unsigned char *actual_sha1_return)
f4913f91 2086{
21666f1a 2087 enum object_type type, required_type;
f4913f91
JH
2088 void *buffer;
2089 unsigned long isize;
40469ee9 2090 unsigned char actual_sha1[20];
f4913f91 2091
21666f1a 2092 required_type = type_from_string(required_type_name);
e702496e 2093 hashcpy(actual_sha1, sha1);
40469ee9
JH
2094 while (1) {
2095 int ref_length = -1;
2096 const char *ref_type = NULL;
f4913f91 2097
21666f1a 2098 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2099 if (!buffer)
2100 return NULL;
21666f1a 2101 if (type == required_type) {
40469ee9
JH
2102 *size = isize;
2103 if (actual_sha1_return)
e702496e 2104 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2105 return buffer;
2106 }
2107 /* Handle references */
21666f1a 2108 else if (type == OBJ_COMMIT)
40469ee9 2109 ref_type = "tree ";
21666f1a 2110 else if (type == OBJ_TAG)
40469ee9
JH
2111 ref_type = "object ";
2112 else {
2113 free(buffer);
2114 return NULL;
2115 }
2116 ref_length = strlen(ref_type);
f4913f91 2117
50974ec9
MK
2118 if (ref_length + 40 > isize ||
2119 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2120 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2121 free(buffer);
2122 return NULL;
2123 }
1cf58e72 2124 free(buffer);
40469ee9
JH
2125 /* Now we have the ID of the referred-to object in
2126 * actual_sha1. Check again. */
f4913f91 2127 }
f4913f91
JH
2128}
2129
ce9fbf16 2130static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2131 const char *type, unsigned char *sha1,
d65a16f6 2132 char *hdr, int *hdrlen)
d410c0f5
JH
2133{
2134 SHA_CTX c;
2135
2136 /* Generate the header */
d65a16f6 2137 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2138
2139 /* Sha1.. */
2140 SHA1_Init(&c);
2141 SHA1_Update(&c, hdr, *hdrlen);
2142 SHA1_Update(&c, buf, len);
2143 SHA1_Final(sha1, &c);
d410c0f5
JH
2144}
2145
230f1322
LT
2146/*
2147 * Move the just written object into its final resting place
2148 */
839837b9 2149int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2150{
e32c0a9c
TR
2151 int ret = 0;
2152 if (link(tmpfile, filename))
2153 ret = errno;
7ebb6fca
LT
2154
2155 /*
2156 * Coda hack - coda doesn't like cross-directory links,
2157 * so we fall back to a rename, which will mean that it
2158 * won't be able to check collisions, but that's not a
2159 * big deal.
2160 *
2161 * The same holds for FAT formatted media.
2162 *
2163 * When this succeeds, we just return 0. We have nothing
2164 * left to unlink.
2165 */
2166 if (ret && ret != EEXIST) {
2167 if (!rename(tmpfile, filename))
230f1322 2168 return 0;
9e48b389 2169 ret = errno;
230f1322
LT
2170 }
2171 unlink(tmpfile);
2172 if (ret) {
2173 if (ret != EEXIST) {
916d081b 2174 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2175 }
2176 /* FIXME!!! Collision check here ? */
2177 }
2178
2179 return 0;
2180}
2181
4d548150
LT
2182static int write_buffer(int fd, const void *buf, size_t len)
2183{
d34cf19b 2184 if (write_in_full(fd, buf, len) < 0)
93822c22 2185 return error("file write error (%s)", strerror(errno));
4d548150
LT
2186 return 0;
2187}
2188
ce9fbf16 2189int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2190 unsigned char *sha1)
2191{
d65a16f6 2192 char hdr[32];
abdc3fc8
RS
2193 int hdrlen;
2194 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2195 return 0;
2196}
2197
e9039dd3
LT
2198/* Finalize a file on disk, and close it. */
2199static void close_sha1_file(int fd)
2200{
aafe9fba
LT
2201 if (fsync_object_files)
2202 fsync_or_die(fd, "sha1 file");
e9039dd3
LT
2203 fchmod(fd, 0444);
2204 if (close(fd) != 0)
2205 die("unable to write sha1 file");
2206}
2207
5723fe7e
LT
2208/* Size of directory component, including the ending '/' */
2209static inline int directory_size(const char *filename)
2210{
2211 const char *s = strrchr(filename, '/');
2212 if (!s)
2213 return 0;
2214 return s - filename + 1;
2215}
2216
2217/*
2218 * This creates a temporary file in the same directory as the final
2219 * 'filename'
2220 *
2221 * We want to avoid cross-directory filename renames, because those
2222 * can have problems on various filesystems (FAT, NFS, Coda).
2223 */
2224static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2225{
2226 int fd, dirlen = directory_size(filename);
2227
2228 if (dirlen + 20 > bufsiz) {
2229 errno = ENAMETOOLONG;
2230 return -1;
2231 }
2232 memcpy(buffer, filename, dirlen);
2233 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
2234 fd = mkstemp(buffer);
65117abc 2235 if (fd < 0 && dirlen && errno == ENOENT) {
5723fe7e 2236 /* Make sure the directory exists */
6ff6af62 2237 memcpy(buffer, filename, dirlen);
5723fe7e 2238 buffer[dirlen-1] = 0;
3bfaf018 2239 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2240 return -1;
2241
2242 /* Try again */
2243 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
2244 fd = mkstemp(buffer);
2245 }
2246 return fd;
2247}
2248
bbac7311
NP
2249static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2250 void *buf, unsigned long len, time_t mtime)
0fcfd160 2251{
bbac7311 2252 int fd, size, ret;
bf0f910d 2253 unsigned char *compressed;
0fcfd160 2254 z_stream stream;
706bc531 2255 char *filename;
aac17941 2256 static char tmpfile[PATH_MAX];
a44c9a5e 2257
972a9155 2258 filename = sha1_file_name(sha1);
5723fe7e 2259 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
aac17941 2260 if (fd < 0) {
35243577 2261 if (errno == EACCES)
916d081b
PB
2262 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2263 else
2264 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2265 }
2266
0fcfd160
LT
2267 /* Set it up */
2268 memset(&stream, 0, sizeof(stream));
12f6c308 2269 deflateInit(&stream, zlib_compression_level);
93821bd9 2270 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2271 compressed = xmalloc(size);
0fcfd160
LT
2272
2273 /* Compress it */
0fcfd160
LT
2274 stream.next_out = compressed;
2275 stream.avail_out = size;
a44c9a5e
LT
2276
2277 /* First header.. */
d65a16f6 2278 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2279 stream.avail_in = hdrlen;
726f852b
NP
2280 while (deflate(&stream, 0) == Z_OK)
2281 /* nothing */;
a44c9a5e
LT
2282
2283 /* Then the data itself.. */
2284 stream.next_in = buf;
2285 stream.avail_in = len;
ac54c277
LT
2286 ret = deflate(&stream, Z_FINISH);
2287 if (ret != Z_STREAM_END)
2288 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2289
2290 ret = deflateEnd(&stream);
2291 if (ret != Z_OK)
2292 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2293
0fcfd160
LT
2294 size = stream.total_out;
2295
4d548150
LT
2296 if (write_buffer(fd, compressed, size) < 0)
2297 die("unable to write sha1 file");
e9039dd3 2298 close_sha1_file(fd);
383f85b7 2299 free(compressed);
0fcfd160 2300
bbac7311
NP
2301 if (mtime) {
2302 struct utimbuf utb;
2303 utb.actime = mtime;
2304 utb.modtime = mtime;
2305 if (utime(tmpfile, &utb) < 0)
2306 warning("failed utime() on %s: %s",
2307 tmpfile, strerror(errno));
2308 }
2309
230f1322 2310 return move_temp_to_file(tmpfile, filename);
0fcfd160 2311}
8237b185 2312
bbac7311
NP
2313int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2314{
2315 unsigned char sha1[20];
2316 char hdr[32];
2317 int hdrlen;
2318
2319 /* Normally if we have it in the pack then we do not bother writing
2320 * it out into .git/objects/??/?{38} file.
2321 */
2322 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2323 if (returnsha1)
2324 hashcpy(returnsha1, sha1);
2325 if (has_sha1_file(sha1))
2326 return 0;
2327 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2328}
2329
2330int force_object_loose(const unsigned char *sha1, time_t mtime)
2331{
bbac7311
NP
2332 void *buf;
2333 unsigned long len;
2334 enum object_type type;
2335 char hdr[32];
2336 int hdrlen;
1fb23e65 2337 int ret;
bbac7311 2338
c529d75a 2339 if (has_loose_object(sha1))
bbac7311
NP
2340 return 0;
2341 buf = read_packed_sha1(sha1, &type, &len);
2342 if (!buf)
2343 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2344 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1fb23e65
BS
2345 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2346 free(buf);
2347
2348 return ret;
bbac7311
NP
2349}
2350
bf592c50
DB
2351int has_pack_index(const unsigned char *sha1)
2352{
2353 struct stat st;
2354 if (stat(sha1_pack_index_name(sha1), &st))
2355 return 0;
2356 return 1;
2357}
2358
2359int has_pack_file(const unsigned char *sha1)
2360{
2361 struct stat st;
2362 if (stat(sha1_pack_name(sha1), &st))
2363 return 0;
2364 return 1;
2365}
2366
106d710b 2367int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2368{
2369 struct pack_entry e;
106d710b 2370 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2371}
2372
8237b185
DB
2373int has_sha1_file(const unsigned char *sha1)
2374{
1f688557
JH
2375 struct pack_entry e;
2376
106d710b 2377 if (find_pack_entry(sha1, &e, NULL))
1f688557 2378 return 1;
c529d75a 2379 return has_loose_object(sha1);
8237b185 2380}
74400e71 2381
e7332f96
BE
2382int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2383{
fd17f5b5 2384 struct strbuf buf;
e7332f96 2385 int ret;
e7332f96 2386
fd17f5b5
PH
2387 strbuf_init(&buf, 0);
2388 if (strbuf_read(&buf, fd, 4096) < 0) {
2389 strbuf_release(&buf);
024510c8
DB
2390 return -1;
2391 }
e7332f96 2392
024510c8 2393 if (!type)
8e440259 2394 type = blob_type;
024510c8 2395 if (write_object)
fd17f5b5 2396 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
abdc3fc8 2397 else
fd17f5b5
PH
2398 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
2399 strbuf_release(&buf);
2400
024510c8
DB
2401 return ret;
2402}
2403
edaec3fb 2404int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
53bca91a 2405 enum object_type type, const char *path)
74400e71 2406{
dc49cd76 2407 size_t size = xsize_t(st->st_size);
3a55602e 2408 void *buf = NULL;
6c510bee 2409 int ret, re_allocated = 0;
74400e71 2410
74400e71 2411 if (size)
c4712e45 2412 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 2413 close(fd);
74400e71 2414
7672db20 2415 if (!type)
edaec3fb 2416 type = OBJ_BLOB;
6c510bee
LT
2417
2418 /*
2419 * Convert blobs to git internal format
2420 */
d0d8e14d 2421 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
5ecd293d
PH
2422 struct strbuf nbuf;
2423 strbuf_init(&nbuf, 0);
21e5ad50
SP
2424 if (convert_to_git(path, buf, size, &nbuf,
2425 write_object ? safe_crlf : 0)) {
ac78e548 2426 munmap(buf, size);
b315c5c0 2427 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2428 re_allocated = 1;
2429 }
2430 }
2431
7672db20 2432 if (write_object)
edaec3fb 2433 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2434 else
edaec3fb 2435 ret = hash_sha1_file(buf, size, typename(type), sha1);
6c510bee
LT
2436 if (re_allocated) {
2437 free(buf);
2438 return ret;
2439 }
aac17941
LT
2440 if (size)
2441 munmap(buf, size);
2442 return ret;
74400e71 2443}
ec1fcc16
JH
2444
2445int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2446{
2447 int fd;
2448 char *target;
dc49cd76 2449 size_t len;
ec1fcc16
JH
2450
2451 switch (st->st_mode & S_IFMT) {
2452 case S_IFREG:
2453 fd = open(path, O_RDONLY);
2454 if (fd < 0)
2455 return error("open(\"%s\"): %s", path,
2456 strerror(errno));
53bca91a 2457 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2458 return error("%s: failed to insert into database",
2459 path);
2460 break;
2461 case S_IFLNK:
dc49cd76
SP
2462 len = xsize_t(st->st_size);
2463 target = xmalloc(len + 1);
2464 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2465 char *errstr = strerror(errno);
2466 free(target);
2467 return error("readlink(\"%s\"): %s", path,
2468 errstr);
2469 }
abdc3fc8 2470 if (!write_object)
dc49cd76
SP
2471 hash_sha1_file(target, len, blob_type, sha1);
2472 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2473 return error("%s: failed to insert into database",
2474 path);
2475 free(target);
2476 break;
f35a6d3b
LT
2477 case S_IFDIR:
2478 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2479 default:
2480 return error("%s: unsupported file type", path);
2481 }
2482 return 0;
2483}
a69e5429
JH
2484
2485int read_pack_header(int fd, struct pack_header *header)
2486{
c697ad14
HO
2487 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2488 /* "eof before pack header was fully read" */
2489 return PH_ERROR_EOF;
2490
a69e5429
JH
2491 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2492 /* "protocol error (pack signature mismatch detected)" */
2493 return PH_ERROR_PACK_SIGNATURE;
2494 if (!pack_version_ok(header->hdr_version))
2495 /* "protocol error (pack version unsupported)" */
2496 return PH_ERROR_PROTOCOL;
2497 return 0;
2498}