Git::cat_blob: allow using an empty blob to fix git-svn breakage
[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
144bde78
LT
38static unsigned int sha1_file_open_flag = O_NOATIME;
39
192a6be2 40const signed char hexval_table[256] = {
e49521b5
JH
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
42 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
45 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
46 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
47 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
48 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
49 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
51 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
53 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
68 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
69 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
70 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
71 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
72 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
73};
0fcfd160
LT
74
75int get_sha1_hex(const char *hex, unsigned char *sha1)
76{
77 int i;
78 for (i = 0; i < 20; i++) {
79 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
80 if (val & ~0xff)
81 return -1;
82 *sha1++ = val;
83 hex += 2;
84 }
85 return 0;
86}
87
b2cb9425
JH
88int safe_create_leading_directories(char *path)
89{
90 char *pos = path;
67d42212
JR
91 struct stat st;
92
85dadc38 93 if (is_absolute_path(path))
67ffdf4c 94 pos++;
b2cb9425
JH
95
96 while (pos) {
97 pos = strchr(pos, '/');
98 if (!pos)
99 break;
100 *pos = 0;
67d42212
JR
101 if (!stat(path, &st)) {
102 /* path exists */
103 if (!S_ISDIR(st.st_mode)) {
b2cb9425 104 *pos = '/';
67d42212 105 return -3;
b2cb9425 106 }
457f06d6 107 }
67d42212
JR
108 else if (mkdir(path, 0777)) {
109 *pos = '/';
110 return -1;
111 }
457f06d6
JS
112 else if (adjust_shared_perm(path)) {
113 *pos = '/';
114 return -2;
115 }
b2cb9425
JH
116 *pos++ = '/';
117 }
118 return 0;
119}
723c31fe 120
0fcfd160
LT
121char * sha1_to_hex(const unsigned char *sha1)
122{
dcb3450f
LT
123 static int bufno;
124 static char hexbuffer[4][50];
0fcfd160 125 static const char hex[] = "0123456789abcdef";
dcb3450f 126 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
127 int i;
128
129 for (i = 0; i < 20; i++) {
130 unsigned int val = *sha1++;
131 *buf++ = hex[val >> 4];
132 *buf++ = hex[val & 0xf];
133 }
1e80e044
JS
134 *buf = '\0';
135
0fcfd160
LT
136 return buffer;
137}
138
ace1534d
JH
139static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
140{
141 int i;
142 for (i = 0; i < 20; i++) {
143 static char hex[] = "0123456789abcdef";
144 unsigned int val = sha1[i];
145 char *pos = pathbuf + i*2 + (i > 0);
146 *pos++ = hex[val >> 4];
147 *pos = hex[val & 0xf];
148 }
149}
150
0fcfd160
LT
151/*
152 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 153 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 154 * filename.
ace1534d
JH
155 *
156 * Also note that this returns the location for creating. Reading
157 * SHA1 file can happen from any alternate directory listed in the
d19938ab 158 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 159 * the primary object database.
0fcfd160
LT
160 */
161char *sha1_file_name(const unsigned char *sha1)
162{
0fcfd160
LT
163 static char *name, *base;
164
165 if (!base) {
d19938ab 166 const char *sha1_file_directory = get_object_directory();
0fcfd160 167 int len = strlen(sha1_file_directory);
812666c8 168 base = xmalloc(len + 60);
0fcfd160
LT
169 memcpy(base, sha1_file_directory, len);
170 memset(base+len, 0, 60);
171 base[len] = '/';
172 base[len+3] = '/';
173 name = base + len + 1;
174 }
ace1534d 175 fill_sha1_path(name, sha1);
0fcfd160
LT
176 return base;
177}
178
633f43e1
HO
179static char *sha1_get_pack_name(const unsigned char *sha1,
180 char **name, char **base)
bf592c50
DB
181{
182 static const char hex[] = "0123456789abcdef";
633f43e1 183 char *buf;
bf592c50
DB
184 int i;
185
633f43e1 186 if (!*base) {
bf592c50
DB
187 const char *sha1_file_directory = get_object_directory();
188 int len = strlen(sha1_file_directory);
633f43e1
HO
189 *base = xmalloc(len + 60);
190 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
191 *name = *base + len + 11;
bf592c50
DB
192 }
193
633f43e1 194 buf = *name;
bf592c50
DB
195
196 for (i = 0; i < 20; i++) {
197 unsigned int val = *sha1++;
198 *buf++ = hex[val >> 4];
199 *buf++ = hex[val & 0xf];
200 }
a6080a0a 201
633f43e1 202 return *base;
bf592c50
DB
203}
204
633f43e1 205char *sha1_pack_name(const unsigned char *sha1)
bf592c50 206{
633f43e1 207 static char *name, *base;
bf592c50 208
633f43e1
HO
209 return sha1_get_pack_name(sha1, &name, &base);
210}
bf592c50 211
633f43e1
HO
212char *sha1_pack_index_name(const unsigned char *sha1)
213{
214 static char *name, *base;
a6080a0a 215
633f43e1 216 return sha1_get_pack_name(sha1, &name, &base);
bf592c50
DB
217}
218
d5a63b99
JH
219struct alternate_object_database *alt_odb_list;
220static struct alternate_object_database **alt_odb_tail;
ace1534d 221
c2f493a4
MW
222static void read_info_alternates(const char * alternates, int depth);
223
ddd5d056
JH
224/*
225 * Prepare alternate object database registry.
d5a63b99
JH
226 *
227 * The variable alt_odb_list points at the list of struct
228 * alternate_object_database. The elements on this list come from
229 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
230 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
231 * whose contents is similar to that environment variable but can be
232 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
233 * contains "/the/directory/corresponding/to/.git/objects/...", while
234 * its name points just after the slash at the end of ".git/objects/"
235 * in the example above, and has enough space to hold 40-byte hex
236 * SHA1, an extra slash for the first level indirection, and the
237 * terminating NUL.
ddd5d056 238 */
c2f493a4 239static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 240{
c2f493a4 241 struct stat st;
1494e038 242 const char *objdir = get_object_directory();
c2f493a4
MW
243 struct alternate_object_database *ent;
244 struct alternate_object_database *alt;
245 /* 43 = 40-byte + 2 '/' + terminating NUL */
246 int pfxlen = len;
247 int entlen = pfxlen + 43;
ccfd3e99 248 int base_len = -1;
d5a63b99 249
85dadc38 250 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
251 /* Relative alt-odb */
252 if (base_len < 0)
253 base_len = strlen(relative_base) + 1;
254 entlen += base_len;
255 pfxlen += base_len;
256 }
257 ent = xmalloc(sizeof(*ent) + entlen);
258
85dadc38 259 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
260 memcpy(ent->base, relative_base, base_len - 1);
261 ent->base[base_len - 1] = '/';
262 memcpy(ent->base + base_len, entry, len);
263 }
264 else
265 memcpy(ent->base, entry, pfxlen);
266
267 ent->name = ent->base + pfxlen + 1;
268 ent->base[pfxlen + 3] = '/';
269 ent->base[pfxlen] = ent->base[entlen-1] = 0;
270
271 /* Detect cases where alternate disappeared */
272 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
273 error("object directory %s does not exist; "
274 "check .git/objects/info/alternates.",
275 ent->base);
276 free(ent);
277 return -1;
278 }
279
280 /* Prevent the common mistake of listing the same
281 * thing twice, or object directory itself.
282 */
283 for (alt = alt_odb_list; alt; alt = alt->next) {
284 if (!memcmp(ent->base, alt->base, pfxlen)) {
285 free(ent);
286 return -1;
287 }
288 }
289 if (!memcmp(ent->base, objdir, pfxlen)) {
290 free(ent);
291 return -1;
292 }
293
294 /* add the alternate entry */
295 *alt_odb_tail = ent;
296 alt_odb_tail = &(ent->next);
297 ent->next = NULL;
298
299 /* recursively add alternates */
300 read_info_alternates(ent->base, depth + 1);
301
302 ent->base[pfxlen] = '/';
303
304 return 0;
305}
306
307static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
308 const char *relative_base, int depth)
309{
310 const char *cp, *last;
311
312 if (depth > 5) {
313 error("%s: ignoring alternate object stores, nesting too deep.",
314 relative_base);
315 return;
316 }
317
d5a63b99 318 last = alt;
9577e7e3
JH
319 while (last < ep) {
320 cp = last;
321 if (cp < ep && *cp == '#') {
322 while (cp < ep && *cp != sep)
323 cp++;
324 last = cp + 1;
325 continue;
326 }
c2f493a4
MW
327 while (cp < ep && *cp != sep)
328 cp++;
d5a63b99 329 if (last != cp) {
85dadc38 330 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
331 error("%s: ignoring relative alternate object store %s",
332 relative_base, last);
333 } else {
334 link_alt_odb_entry(last, cp - last,
335 relative_base, depth);
1494e038 336 }
d5a63b99 337 }
9577e7e3 338 while (cp < ep && *cp == sep)
d5a63b99
JH
339 cp++;
340 last = cp;
9577e7e3 341 }
d5a63b99
JH
342}
343
c2f493a4 344static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 345{
9577e7e3 346 char *map;
dc49cd76 347 size_t mapsz;
d5a63b99 348 struct stat st;
9cb18f56
JM
349 const char alt_file_name[] = "info/alternates";
350 /* Given that relative_base is no longer than PATH_MAX,
351 ensure that "path" has enough space to append "/", the
352 file name, "info/alternates", and a trailing NUL. */
353 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 354 int fd;
d5a63b99 355
9cb18f56 356 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
357 fd = open(path, O_RDONLY);
358 if (fd < 0)
359 return;
360 if (fstat(fd, &st) || (st.st_size == 0)) {
361 close(fd);
9a217f2a 362 return;
ace1534d 363 }
dc49cd76
SP
364 mapsz = xsize_t(st.st_size);
365 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 366 close(fd);
d5a63b99 367
dc49cd76 368 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 369
dc49cd76 370 munmap(map, mapsz);
ace1534d
JH
371}
372
bef70b22
DB
373void add_to_alternates_file(const char *reference)
374{
375 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
376 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), 1);
377 char *alt = mkpath("%s/objects\n", reference);
378 write_or_die(fd, alt, strlen(alt));
379 if (commit_lock_file(lock))
380 die("could not close alternates file");
381 if (alt_odb_tail)
382 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
383}
384
c2f493a4
MW
385void prepare_alt_odb(void)
386{
554fe20d 387 const char *alt;
c2f493a4 388
7dc24aa5
SP
389 if (alt_odb_tail)
390 return;
391
c2f493a4
MW
392 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
393 if (!alt) alt = "";
394
c2f493a4
MW
395 alt_odb_tail = &alt_odb_list;
396 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
397
398 read_info_alternates(get_object_directory(), 0);
399}
400
ace1534d
JH
401static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
402{
ace1534d 403 char *name = sha1_file_name(sha1);
d5a63b99 404 struct alternate_object_database *alt;
ace1534d
JH
405
406 if (!stat(name, st))
407 return name;
9a217f2a 408 prepare_alt_odb();
d5a63b99
JH
409 for (alt = alt_odb_list; alt; alt = alt->next) {
410 name = alt->name;
ace1534d 411 fill_sha1_path(name, sha1);
d5a63b99
JH
412 if (!stat(alt->base, st))
413 return alt->base;
ace1534d
JH
414 }
415 return NULL;
416}
417
60bb8b14 418static unsigned int pack_used_ctr;
a53128b6
SP
419static unsigned int pack_mmap_calls;
420static unsigned int peak_pack_open_windows;
421static unsigned int pack_open_windows;
422static size_t peak_pack_mapped;
60bb8b14 423static size_t pack_mapped;
9a217f2a 424struct packed_git *packed_git;
1f688557 425
b79d18c9 426void pack_report(void)
a53128b6
SP
427{
428 fprintf(stderr,
e05db0fd
PR
429 "pack_report: getpagesize() = %10" SZ_FMT "\n"
430 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
431 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
432 sz_fmt(getpagesize()),
433 sz_fmt(packed_git_window_size),
434 sz_fmt(packed_git_limit));
a53128b6
SP
435 fprintf(stderr,
436 "pack_report: pack_used_ctr = %10u\n"
437 "pack_report: pack_mmap_calls = %10u\n"
438 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
439 "pack_report: pack_mapped = "
440 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
441 pack_used_ctr,
442 pack_mmap_calls,
443 pack_open_windows, peak_pack_open_windows,
9e42d6a1 444 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
445}
446
42873078 447static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
448{
449 void *idx_map;
42873078 450 struct pack_idx_header *hdr;
dc49cd76 451 size_t idx_size;
74e34e1f 452 uint32_t version, nr, i, *index;
e93ec6f9 453 int fd = open(path, O_RDONLY);
1f688557 454 struct stat st;
42873078 455
1f688557
JH
456 if (fd < 0)
457 return -1;
458 if (fstat(fd, &st)) {
459 close(fd);
460 return -1;
461 }
dc49cd76 462 idx_size = xsize_t(st.st_size);
2d88451b
SP
463 if (idx_size < 4 * 256 + 20 + 20) {
464 close(fd);
465 return error("index file %s is too small", path);
466 }
c4712e45 467 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 468 close(fd);
1f688557 469
42873078
NP
470 hdr = idx_map;
471 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
472 version = ntohl(hdr->idx_version);
473 if (version < 2 || version > 2) {
474 munmap(idx_map, idx_size);
475 return error("index file %s is version %d"
476 " and is not supported by this binary"
477 " (try upgrading GIT to a newer version)",
478 path, version);
479 }
480 } else
481 version = 1;
df1b059d 482
1f688557 483 nr = 0;
42873078 484 index = idx_map;
74e34e1f
NP
485 if (version > 1)
486 index += 2; /* skip index header */
1f688557 487 for (i = 0; i < 256; i++) {
326bf396 488 uint32_t n = ntohl(index[i]);
2d88451b
SP
489 if (n < nr) {
490 munmap(idx_map, idx_size);
df1b059d 491 return error("non-monotonic index %s", path);
2d88451b 492 }
1f688557
JH
493 nr = n;
494 }
495
74e34e1f
NP
496 if (version == 1) {
497 /*
498 * Total size:
499 * - 256 index entries 4 bytes each
500 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
501 * - 20-byte SHA1 of the packfile
502 * - 20-byte SHA1 file checksum
503 */
504 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
505 munmap(idx_map, idx_size);
eef427a0 506 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
507 }
508 } else if (version == 2) {
509 /*
510 * Minimum size:
511 * - 8 bytes of header
512 * - 256 index entries 4 bytes each
513 * - 20-byte sha1 entry * nr
514 * - 4-byte crc entry * nr
515 * - 4-byte offset entry * nr
516 * - 20-byte SHA1 of the packfile
517 * - 20-byte SHA1 file checksum
518 * And after the 4-byte offset table might be a
519 * variable sized table containing 8-byte entries
520 * for offsets larger than 2^31.
521 */
522 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
523 unsigned long max_size = min_size;
524 if (nr)
525 max_size += (nr - 1)*8;
526 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 527 munmap(idx_map, idx_size);
eef427a0 528 return error("wrong index v2 file size in %s", path);
74e34e1f 529 }
7109c889
JH
530 if (idx_size != min_size &&
531 /*
532 * make sure we can deal with large pack offsets.
533 * 31-bit signed offset won't be enough, neither
534 * 32-bit unsigned one will be.
535 */
536 (sizeof(off_t) <= 4)) {
537 munmap(idx_map, idx_size);
538 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 539 }
2d88451b 540 }
1f688557 541
74e34e1f 542 p->index_version = version;
42873078
NP
543 p->index_data = idx_map;
544 p->index_size = idx_size;
57059091 545 p->num_objects = nr;
1f688557
JH
546 return 0;
547}
548
bc8e478a 549int open_pack_index(struct packed_git *p)
d079837e
SP
550{
551 char *idx_name;
552 int ret;
553
554 if (p->index_data)
555 return 0;
556
557 idx_name = xstrdup(p->pack_name);
558 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
559 ret = check_packed_git_idx(idx_name, p);
560 free(idx_name);
561 return ret;
562}
563
11daf39b
SP
564static void scan_windows(struct packed_git *p,
565 struct packed_git **lru_p,
566 struct pack_window **lru_w,
567 struct pack_window **lru_l)
1f688557 568{
11daf39b
SP
569 struct pack_window *w, *w_l;
570
571 for (w_l = NULL, w = p->windows; w; w = w->next) {
572 if (!w->inuse_cnt) {
573 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
574 *lru_p = p;
575 *lru_w = w;
576 *lru_l = w_l;
54044bf8 577 }
54044bf8 578 }
11daf39b 579 w_l = w;
f9253394 580 }
11daf39b
SP
581}
582
d1efefa4 583static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
584{
585 struct packed_git *p, *lru_p = NULL;
586 struct pack_window *lru_w = NULL, *lru_l = NULL;
587
588 if (current)
589 scan_windows(current, &lru_p, &lru_w, &lru_l);
590 for (p = packed_git; p; p = p->next)
591 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
592 if (lru_p) {
593 munmap(lru_w->base, lru_w->len);
594 pack_mapped -= lru_w->len;
595 if (lru_l)
596 lru_l->next = lru_w->next;
597 else {
598 lru_p->windows = lru_w->next;
d1efefa4 599 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
600 close(lru_p->pack_fd);
601 lru_p->pack_fd = -1;
602 }
603 }
604 free(lru_w);
a53128b6 605 pack_open_windows--;
54044bf8
SP
606 return 1;
607 }
608 return 0;
f9253394
JH
609}
610
d1efefa4 611void release_pack_memory(size_t need, int fd)
97bfeb34
SP
612{
613 size_t cur = pack_mapped;
d1efefa4 614 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
615 ; /* nothing */
616}
617
c9ced051
SP
618void close_pack_windows(struct packed_git *p)
619{
620 while (p->windows) {
621 struct pack_window *w = p->windows;
622
623 if (w->inuse_cnt)
624 die("pack '%s' still has open windows to it",
625 p->pack_name);
626 munmap(w->base, w->len);
627 pack_mapped -= w->len;
628 pack_open_windows--;
629 p->windows = w->next;
630 free(w);
631 }
632}
633
03e79c88 634void unuse_pack(struct pack_window **w_cursor)
f9253394 635{
03e79c88
SP
636 struct pack_window *w = *w_cursor;
637 if (w) {
638 w->inuse_cnt--;
639 *w_cursor = NULL;
640 }
1f688557
JH
641}
642
3cf8b462
SP
643/*
644 * Do not call this directly as this leaks p->pack_fd on error return;
645 * call open_packed_git() instead.
646 */
647static int open_packed_git_1(struct packed_git *p)
1f688557 648{
9bc879c1
SP
649 struct stat st;
650 struct pack_header hdr;
651 unsigned char sha1[20];
652 unsigned char *idx_sha1;
2c039da8 653 long fd_flag;
9bc879c1 654
d079837e
SP
655 if (!p->index_data && open_pack_index(p))
656 return error("packfile %s index unavailable", p->pack_name);
657
9bc879c1
SP
658 p->pack_fd = open(p->pack_name, O_RDONLY);
659 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 660 return -1;
9bc879c1
SP
661
662 /* If we created the struct before we had the pack we lack size. */
bf592c50 663 if (!p->pack_size) {
bf592c50 664 if (!S_ISREG(st.st_mode))
072db278 665 return error("packfile %s not a regular file", p->pack_name);
bf592c50 666 p->pack_size = st.st_size;
9bc879c1 667 } else if (p->pack_size != st.st_size)
072db278 668 return error("packfile %s size changed", p->pack_name);
9bc879c1 669
2c039da8
JH
670 /* We leave these file descriptors open with sliding mmap;
671 * there is no point keeping them open across exec(), though.
672 */
673 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
674 if (fd_flag < 0)
072db278 675 return error("cannot determine file descriptor flags");
2c039da8
JH
676 fd_flag |= FD_CLOEXEC;
677 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 678 return error("cannot set FD_CLOEXEC");
2c039da8 679
9bc879c1 680 /* Verify we recognize this pack file format. */
e6e2bd62 681 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 682 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 683 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 684 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 685 if (!pack_version_ok(hdr.hdr_version))
072db278 686 return error("packfile %s is version %u and not supported"
9bc879c1
SP
687 " (try upgrading GIT to a newer version)",
688 p->pack_name, ntohl(hdr.hdr_version));
689
690 /* Verify the pack matches its index. */
57059091 691 if (p->num_objects != ntohl(hdr.hdr_entries))
072db278 692 return error("packfile %s claims to have %u objects"
57059091
NP
693 " while index indicates %u objects",
694 p->pack_name, ntohl(hdr.hdr_entries),
695 p->num_objects);
9bc879c1 696 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 697 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 698 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 699 return error("packfile %s signature is unavailable", p->pack_name);
42873078 700 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 701 if (hashcmp(sha1, idx_sha1))
072db278
SP
702 return error("packfile %s does not match index", p->pack_name);
703 return 0;
9bc879c1
SP
704}
705
3cf8b462
SP
706static int open_packed_git(struct packed_git *p)
707{
708 if (!open_packed_git_1(p))
709 return 0;
710 if (p->pack_fd != -1) {
711 close(p->pack_fd);
712 p->pack_fd = -1;
713 }
714 return -1;
715}
716
c4001d92 717static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
718{
719 /* We must promise at least 20 bytes (one hash) after the
720 * offset is available from this window, otherwise the offset
721 * is not actually in this window and a different window (which
722 * has that one hash excess) must be used. This is to support
723 * the object header and delta base parsing routines below.
724 */
725 off_t win_off = win->offset;
726 return win_off <= offset
727 && (offset + 20) <= (win_off + win->len);
728}
729
03e79c88
SP
730unsigned char* use_pack(struct packed_git *p,
731 struct pack_window **w_cursor,
c4001d92 732 off_t offset,
03e79c88 733 unsigned int *left)
9bc879c1 734{
60bb8b14 735 struct pack_window *win = *w_cursor;
03e79c88 736
072db278
SP
737 if (p->pack_fd == -1 && open_packed_git(p))
738 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
739
740 /* Since packfiles end in a hash of their content and its
741 * pointless to ask for an offset into the middle of that
742 * hash, and the in_window function above wouldn't match
743 * don't allow an offset too close to the end of the file.
744 */
745 if (offset > (p->pack_size - 20))
746 die("offset beyond end of packfile (truncated pack?)");
747
748 if (!win || !in_window(win, offset)) {
749 if (win)
750 win->inuse_cnt--;
751 for (win = p->windows; win; win = win->next) {
752 if (in_window(win, offset))
753 break;
754 }
755 if (!win) {
78a28df9 756 size_t window_align = packed_git_window_size / 2;
dc49cd76 757 off_t len;
60bb8b14 758 win = xcalloc(1, sizeof(*win));
78a28df9 759 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
760 len = p->pack_size - win->offset;
761 if (len > packed_git_window_size)
762 len = packed_git_window_size;
763 win->len = (size_t)len;
60bb8b14 764 pack_mapped += win->len;
11daf39b 765 while (packed_git_limit < pack_mapped
d1efefa4 766 && unuse_one_window(p, p->pack_fd))
60bb8b14 767 ; /* nothing */
c4712e45 768 win->base = xmmap(NULL, win->len,
60bb8b14
SP
769 PROT_READ, MAP_PRIVATE,
770 p->pack_fd, win->offset);
771 if (win->base == MAP_FAILED)
73b4e4be
SP
772 die("packfile %s cannot be mapped: %s",
773 p->pack_name,
774 strerror(errno));
a53128b6
SP
775 pack_mmap_calls++;
776 pack_open_windows++;
777 if (pack_mapped > peak_pack_mapped)
778 peak_pack_mapped = pack_mapped;
779 if (pack_open_windows > peak_pack_open_windows)
780 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
781 win->next = p->windows;
782 p->windows = win;
783 }
1f688557 784 }
03e79c88
SP
785 if (win != *w_cursor) {
786 win->last_used = pack_used_ctr++;
787 win->inuse_cnt++;
788 *w_cursor = win;
789 }
60bb8b14 790 offset -= win->offset;
03e79c88 791 if (left)
dc49cd76 792 *left = win->len - xsize_t(offset);
03e79c88 793 return win->base + offset;
1f688557
JH
794}
795
42873078 796struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
797{
798 struct stat st;
42873078 799 struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
1f688557 800
42873078
NP
801 /*
802 * Make sure a corresponding .pack file exists and that
803 * the index looks sane.
804 */
805 path_len -= strlen(".idx");
806 if (path_len < 1)
1f688557 807 return NULL;
42873078
NP
808 memcpy(p->pack_name, path, path_len);
809 strcpy(p->pack_name + path_len, ".pack");
d079837e 810 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 811 free(p);
1f688557
JH
812 return NULL;
813 }
42873078 814
1f688557
JH
815 /* ok, it looks sane as far as we can check without
816 * actually mapping the pack file.
817 */
d079837e
SP
818 p->index_version = 0;
819 p->index_data = NULL;
820 p->index_size = 0;
821 p->num_objects = 0;
1f688557 822 p->pack_size = st.st_size;
1f688557 823 p->next = NULL;
c41ee586 824 p->windows = NULL;
9bc879c1 825 p->pack_fd = -1;
9d835df2 826 p->pack_local = local;
b867092f 827 p->mtime = st.st_mtime;
42873078
NP
828 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
829 hashclr(p->sha1);
1f688557
JH
830 return p;
831}
832
bf592c50 833struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
834{
835 char *path = sha1_pack_index_name(sha1);
836 return parse_pack_index_file(sha1, path);
837}
838
42873078
NP
839struct packed_git *parse_pack_index_file(const unsigned char *sha1,
840 const char *idx_path)
bf592c50 841{
42873078
NP
842 const char *path = sha1_pack_name(sha1);
843 struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
bf592c50 844
42873078
NP
845 if (check_packed_git_idx(idx_path, p)) {
846 free(p);
bf592c50 847 return NULL;
42873078 848 }
bf592c50 849
bf592c50 850 strcpy(p->pack_name, path);
bf592c50 851 p->pack_size = 0;
bf592c50 852 p->next = NULL;
c41ee586 853 p->windows = NULL;
9bc879c1 854 p->pack_fd = -1;
e702496e 855 hashcpy(p->sha1, sha1);
bf592c50
DB
856 return p;
857}
858
859void install_packed_git(struct packed_git *pack)
860{
861 pack->next = packed_git;
862 packed_git = pack;
863}
864
9d835df2 865static void prepare_packed_git_one(char *objdir, int local)
1f688557 866{
9cb18f56
JM
867 /* Ensure that this buffer is large enough so that we can
868 append "/pack/" without clobbering the stack even if
869 strlen(objdir) were PATH_MAX. */
870 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
871 int len;
872 DIR *dir;
873 struct dirent *de;
874
875 sprintf(path, "%s/pack", objdir);
876 len = strlen(path);
877 dir = opendir(path);
b5b16990 878 if (!dir) {
26125f6b 879 if (errno != ENOENT)
bd2afde8 880 error("unable to open object pack directory: %s: %s",
26125f6b 881 path, strerror(errno));
1f688557 882 return;
b5b16990 883 }
1f688557
JH
884 path[len++] = '/';
885 while ((de = readdir(dir)) != NULL) {
886 int namelen = strlen(de->d_name);
887 struct packed_git *p;
888
5bb1cda5 889 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
890 continue;
891
9cb18f56
JM
892 if (len + namelen + 1 > sizeof(path))
893 continue;
894
54a15a8d 895 /* Don't reopen a pack we already have. */
1f688557 896 strcpy(path + len, de->d_name);
86f7780c
JK
897 for (p = packed_git; p; p = p->next) {
898 if (!memcmp(path, p->pack_name, len + namelen - 4))
899 break;
900 }
901 if (p)
902 continue;
54a15a8d
SP
903 /* See if it really is a valid .idx file with corresponding
904 * .pack file that we can map.
905 */
9d835df2 906 p = add_packed_git(path, len + namelen, local);
1f688557
JH
907 if (!p)
908 continue;
625e9421 909 install_packed_git(p);
1f688557 910 }
5b35bcd5 911 closedir(dir);
1f688557
JH
912}
913
b867092f
JH
914static int sort_pack(const void *a_, const void *b_)
915{
916 struct packed_git *a = *((struct packed_git **)a_);
917 struct packed_git *b = *((struct packed_git **)b_);
918 int st;
919
920 /*
921 * Local packs tend to contain objects specific to our
922 * variant of the project than remote ones. In addition,
923 * remote ones could be on a network mounted filesystem.
924 * Favor local ones for these reasons.
925 */
926 st = a->pack_local - b->pack_local;
927 if (st)
928 return -st;
929
930 /*
931 * Younger packs tend to contain more recent objects,
932 * and more recent objects tend to get accessed more
933 * often.
934 */
935 if (a->mtime < b->mtime)
936 return 1;
937 else if (a->mtime == b->mtime)
938 return 0;
939 return -1;
940}
941
942static void rearrange_packed_git(void)
943{
944 struct packed_git **ary, *p;
945 int i, n;
946
947 for (n = 0, p = packed_git; p; p = p->next)
948 n++;
949 if (n < 2)
950 return;
951
952 /* prepare an array of packed_git for easier sorting */
953 ary = xcalloc(n, sizeof(struct packed_git *));
954 for (n = 0, p = packed_git; p; p = p->next)
955 ary[n++] = p;
956
957 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
958
959 /* link them back again */
960 for (i = 0; i < n - 1; i++)
961 ary[i]->next = ary[i + 1];
962 ary[n - 1]->next = NULL;
963 packed_git = ary[0];
964
965 free(ary);
966}
967
637cdd9d 968static int prepare_packed_git_run_once = 0;
9a217f2a 969void prepare_packed_git(void)
1f688557 970{
d5a63b99 971 struct alternate_object_database *alt;
1f688557 972
637cdd9d 973 if (prepare_packed_git_run_once)
1f688557 974 return;
9d835df2 975 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 976 prepare_alt_odb();
d5a63b99 977 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 978 alt->name[-1] = 0;
9d835df2 979 prepare_packed_git_one(alt->base, 0);
1494e038 980 alt->name[-1] = '/';
1f688557 981 }
b867092f 982 rearrange_packed_git();
637cdd9d
JK
983 prepare_packed_git_run_once = 1;
984}
985
fc04c412 986void reprepare_packed_git(void)
637cdd9d
JK
987{
988 prepare_packed_git_run_once = 0;
989 prepare_packed_git();
1f688557
JH
990}
991
5d6ccf5c 992int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
993{
994 unsigned char real_sha1[20];
7cfb5f36 995 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 996 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
997}
998
4175e9e3 999static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1000{
0fcfd160
LT
1001 struct stat st;
1002 void *map;
144bde78 1003 int fd;
ace1534d
JH
1004 char *filename = find_sha1_file(sha1, &st);
1005
1006 if (!filename) {
ace1534d
JH
1007 return NULL;
1008 }
0fcfd160 1009
144bde78 1010 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 1011 if (fd < 0) {
144bde78
LT
1012 /* See if it works without O_NOATIME */
1013 switch (sha1_file_open_flag) {
1014 default:
1015 fd = open(filename, O_RDONLY);
1016 if (fd >= 0)
1017 break;
1018 /* Fallthrough */
1019 case 0:
144bde78
LT
1020 return NULL;
1021 }
1022
1f688557
JH
1023 /* If it failed once, it will probably fail again.
1024 * Stop using O_NOATIME
1025 */
144bde78 1026 sha1_file_open_flag = 0;
0fcfd160 1027 }
dc49cd76
SP
1028 *size = xsize_t(st.st_size);
1029 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
0fcfd160 1030 close(fd);
0fcfd160
LT
1031 return map;
1032}
1033
726f852b 1034static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1035{
1036 unsigned int word;
1037
1038 /*
1039 * Is it a zlib-compressed buffer? If so, the first byte
1040 * must be 0x78 (15-bit window size, deflated), and the
1041 * first 16-bit word is evenly divisible by 31
1042 */
1043 word = (map[0] << 8) + map[1];
1044 if (map[0] == 0x78 && !(word % 31))
1045 return 1;
1046 else
1047 return 0;
1048}
1049
72518e9c 1050unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1051{
ad1ed5ee 1052 unsigned shift;
93821bd9 1053 unsigned char c;
93821bd9 1054 unsigned long size;
ad1ed5ee
JH
1055 unsigned long used = 0;
1056
1057 c = buf[used++];
1058 *type = (c >> 4) & 7;
1059 size = c & 15;
1060 shift = 4;
1061 while (c & 0x80) {
1062 if (len <= used)
1063 return 0;
1064 if (sizeof(long) * 8 <= shift)
1065 return 0;
1066 c = buf[used++];
1067 size += (c & 0x7f) << shift;
1068 shift += 7;
1069 }
1070 *sizep = size;
1071 return used;
1072}
1073
1074static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1075{
1076 unsigned long size, used;
1077 static const char valid_loose_object_type[8] = {
1078 0, /* OBJ_EXT */
1079 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1080 0, /* "delta" and others are invalid in a loose object */
93821bd9 1081 };
ad1ed5ee 1082 enum object_type type;
93821bd9 1083
c4483576
LT
1084 /* Get the data stream */
1085 memset(stream, 0, sizeof(*stream));
1086 stream->next_in = map;
1087 stream->avail_in = mapsize;
1088 stream->next_out = buffer;
93821bd9
LT
1089 stream->avail_out = bufsiz;
1090
bb6b8e4f 1091 if (legacy_loose_object(map)) {
93821bd9
LT
1092 inflateInit(stream);
1093 return inflate(stream, 0);
1094 }
1095
726f852b
NP
1096
1097 /*
1098 * There used to be a second loose object header format which
1099 * was meant to mimic the in-pack format, allowing for direct
1100 * copy of the object data. This format turned up not to be
1101 * really worth it and we don't write it any longer. But we
1102 * can still read it.
1103 */
ad1ed5ee
JH
1104 used = unpack_object_header_gently(map, mapsize, &type, &size);
1105 if (!used || !valid_loose_object_type[type])
93821bd9 1106 return -1;
ad1ed5ee
JH
1107 map += used;
1108 mapsize -= used;
93821bd9
LT
1109
1110 /* Set up the stream for the rest.. */
1111 stream->next_in = map;
1112 stream->avail_in = mapsize;
c4483576 1113 inflateInit(stream);
93821bd9
LT
1114
1115 /* And generate the fake traditional header */
ad1ed5ee 1116 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1117 typename(type), size);
93821bd9 1118 return 0;
c4483576
LT
1119}
1120
7efbff75 1121static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1122{
1123 int bytes = strlen(buffer) + 1;
d565b341 1124 unsigned char *buf = xmalloc(1+size);
93821bd9 1125 unsigned long n;
7efbff75 1126 int status = Z_OK;
5180cacc 1127
93821bd9
LT
1128 n = stream->total_out - bytes;
1129 if (n > size)
1130 n = size;
1131 memcpy(buf, (char *) buffer + bytes, n);
1132 bytes = n;
456cdf6e
LT
1133 if (bytes <= size) {
1134 /*
1135 * The above condition must be (bytes <= size), not
1136 * (bytes < size). In other words, even though we
1137 * expect no more output and set avail_out to zer0,
1138 * the input zlib stream may have bytes that express
1139 * "this concludes the stream", and we *do* want to
1140 * eat that input.
1141 *
1142 * Otherwise we would not be able to test that we
1143 * consumed all the input to reach the expected size;
1144 * we also want to check that zlib tells us that all
1145 * went well with status == Z_STREAM_END at the end.
1146 */
5180cacc
LT
1147 stream->next_out = buf + bytes;
1148 stream->avail_out = size - bytes;
7efbff75
JH
1149 while (status == Z_OK)
1150 status = inflate(stream, Z_FINISH);
5180cacc
LT
1151 }
1152 buf[size] = 0;
456cdf6e 1153 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1154 inflateEnd(stream);
1155 return buf;
1156 }
1157
1158 if (status < 0)
1159 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1160 else if (stream->avail_in)
1161 error("garbage at end of loose object '%s'",
1162 sha1_to_hex(sha1));
1163 free(buf);
1164 return NULL;
5180cacc
LT
1165}
1166
1167/*
1168 * We used to just use "sscanf()", but that's actually way
1169 * too permissive for what we want to check. So do an anal
1170 * object header parse by hand.
1171 */
21666f1a 1172static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1173{
21666f1a 1174 char type[10];
5180cacc
LT
1175 int i;
1176 unsigned long size;
1177
1178 /*
a6080a0a 1179 * The type can be at most ten bytes (including the
5180cacc 1180 * terminating '\0' that we add), and is followed by
21666f1a 1181 * a space.
5180cacc 1182 */
21666f1a 1183 i = 0;
5180cacc
LT
1184 for (;;) {
1185 char c = *hdr++;
1186 if (c == ' ')
1187 break;
21666f1a
NP
1188 type[i++] = c;
1189 if (i >= sizeof(type))
5180cacc 1190 return -1;
5180cacc 1191 }
21666f1a 1192 type[i] = 0;
5180cacc
LT
1193
1194 /*
1195 * The length must follow immediately, and be in canonical
1196 * decimal format (ie "010" is not valid).
1197 */
1198 size = *hdr++ - '0';
1199 if (size > 9)
1200 return -1;
1201 if (size) {
1202 for (;;) {
1203 unsigned long c = *hdr - '0';
1204 if (c > 9)
1205 break;
1206 hdr++;
1207 size = size * 10 + c;
1208 }
1209 }
1210 *sizep = size;
1211
1212 /*
1213 * The length must be followed by a zero byte
1214 */
21666f1a 1215 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1216}
1217
7efbff75 1218static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1219{
5180cacc 1220 int ret;
0fcfd160 1221 z_stream stream;
5180cacc 1222 char hdr[8192];
0fcfd160 1223
5180cacc 1224 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1225 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1226 return NULL;
1227
7efbff75 1228 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1229}
1230
54dab52a
NP
1231unsigned long get_size_from_delta(struct packed_git *p,
1232 struct pack_window **w_curs,
1233 off_t curpos)
1234{
1235 const unsigned char *data;
1236 unsigned char delta_head[20], *in;
1237 z_stream stream;
1238 int st;
1239
1240 memset(&stream, 0, sizeof(stream));
1241 stream.next_out = delta_head;
1242 stream.avail_out = sizeof(delta_head);
1243
1244 inflateInit(&stream);
1245 do {
1246 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1247 stream.next_in = in;
1248 st = inflate(&stream, Z_FINISH);
1249 curpos += stream.next_in - in;
1250 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1251 stream.total_out < sizeof(delta_head));
1252 inflateEnd(&stream);
1253 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1254 die("delta data unpack-initial failed");
1255
1256 /* Examine the initial part of the delta to figure out
1257 * the result size.
1258 */
1259 data = delta_head;
1260
1261 /* ignore base size */
1262 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1263
1264 /* Read the result size */
1265 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1266}
1267
c4001d92 1268static off_t get_delta_base(struct packed_git *p,
03e79c88 1269 struct pack_window **w_curs,
c4001d92 1270 off_t *curpos,
21666f1a 1271 enum object_type type,
c4001d92 1272 off_t delta_obj_offset)
eb32d236 1273{
2b87c45b 1274 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1275 off_t base_offset;
eb32d236 1276
8d8a4ea5
SP
1277 /* use_pack() assured us we have [base_info, base_info + 20)
1278 * as a range that we can look at without walking off the
1279 * end of the mapped window. Its actually the hash size
1280 * that is assured. An OFS_DELTA longer than the hash size
1281 * is stupid, as then a REF_DELTA would be smaller to store.
1282 */
21666f1a 1283 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1284 unsigned used = 0;
1285 unsigned char c = base_info[used++];
1286 base_offset = c & 127;
1287 while (c & 128) {
1288 base_offset += 1;
8723f216 1289 if (!base_offset || MSB(base_offset, 7))
eb32d236
NP
1290 die("offset value overflow for delta base object");
1291 c = base_info[used++];
1292 base_offset = (base_offset << 7) + (c & 127);
1293 }
1294 base_offset = delta_obj_offset - base_offset;
1295 if (base_offset >= delta_obj_offset)
1296 die("delta base offset out of bound");
2b87c45b 1297 *curpos += used;
21666f1a 1298 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1299 /* The base entry _must_ be in the same pack */
1300 base_offset = find_pack_entry_one(base_info, p);
1301 if (!base_offset)
1302 die("failed to find delta-pack base object %s",
1303 sha1_to_hex(base_info));
2b87c45b 1304 *curpos += 20;
eb32d236
NP
1305 } else
1306 die("I am totally screwed");
2b87c45b 1307 return base_offset;
eb32d236
NP
1308}
1309
f3bf9224 1310/* forward declaration for a mutually recursive function */
c4001d92 1311static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1312 unsigned long *sizep);
f3bf9224 1313
43057304 1314static int packed_delta_info(struct packed_git *p,
03e79c88 1315 struct pack_window **w_curs,
c4001d92 1316 off_t curpos,
21666f1a 1317 enum object_type type,
c4001d92 1318 off_t obj_offset,
43057304 1319 unsigned long *sizep)
5db47c2b 1320{
c4001d92 1321 off_t base_offset;
f3bf9224 1322
21666f1a
NP
1323 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1324 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1325
c62266f3
JH
1326 /* We choose to only get the type of the base object and
1327 * ignore potentially corrupt pack file that expects the delta
1328 * based on a base with a wrong size. This saves tons of
1329 * inflate() calls.
1330 */
54dab52a
NP
1331 if (sizep)
1332 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1333
1334 return type;
5db47c2b
JH
1335}
1336
2b87c45b
NP
1337static int unpack_object_header(struct packed_git *p,
1338 struct pack_window **w_curs,
c4001d92 1339 off_t *curpos,
2b87c45b 1340 unsigned long *sizep)
a733cb60 1341{
03e79c88
SP
1342 unsigned char *base;
1343 unsigned int left;
ad1ed5ee 1344 unsigned long used;
2b87c45b 1345 enum object_type type;
a733cb60 1346
8d8a4ea5
SP
1347 /* use_pack() assures us we have [base, base + 20) available
1348 * as a range that we can look at at. (Its actually the hash
3dff5379 1349 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1350 * the maximum deflated object size is 2^137, which is just
1351 * insane, so we know won't exceed what we have been given.
1352 */
2b87c45b
NP
1353 base = use_pack(p, w_curs, *curpos, &left);
1354 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1355 if (!used)
1356 die("object offset outside of pack file");
2b87c45b 1357 *curpos += used;
ad1ed5ee 1358
2b87c45b 1359 return type;
a733cb60
LT
1360}
1361
21666f1a 1362const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1363 off_t obj_offset,
21666f1a
NP
1364 unsigned long *size,
1365 unsigned long *store_size,
1366 unsigned int *delta_chain_length,
1367 unsigned char *base_sha1)
ad8c80a5 1368{
03e79c88 1369 struct pack_window *w_curs = NULL;
c4001d92
SP
1370 off_t curpos;
1371 unsigned long dummy;
43057304 1372 unsigned char *next_sha1;
21666f1a 1373 enum object_type type;
70f5d5d3 1374 struct revindex_entry *revidx;
ad8c80a5 1375
43057304 1376 *delta_chain_length = 0;
2b87c45b 1377 curpos = obj_offset;
21666f1a 1378 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304 1379
70f5d5d3
NP
1380 revidx = find_pack_revindex(p, obj_offset);
1381 *store_size = revidx[1].offset - obj_offset;
1382
43057304 1383 for (;;) {
21666f1a 1384 switch (type) {
43057304 1385 default:
08a19d87 1386 die("pack %s contains unknown object type %d",
21666f1a 1387 p->pack_name, type);
43057304
NP
1388 case OBJ_COMMIT:
1389 case OBJ_TREE:
1390 case OBJ_BLOB:
1391 case OBJ_TAG:
03e79c88 1392 unuse_pack(&w_curs);
21666f1a 1393 return typename(type);
eb32d236 1394 case OBJ_OFS_DELTA:
21666f1a 1395 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
eb32d236 1396 if (*delta_chain_length == 0) {
70f5d5d3
NP
1397 revidx = find_pack_revindex(p, obj_offset);
1398 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
eb32d236
NP
1399 }
1400 break;
1401 case OBJ_REF_DELTA:
2b87c45b 1402 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1403 if (*delta_chain_length == 0)
1404 hashcpy(base_sha1, next_sha1);
2b87c45b 1405 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1406 break;
1407 }
43057304 1408 (*delta_chain_length)++;
2b87c45b 1409 curpos = obj_offset;
21666f1a 1410 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1411 }
ad8c80a5
JH
1412}
1413
c4001d92 1414static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1415 unsigned long *sizep)
1f688557 1416{
03e79c88 1417 struct pack_window *w_curs = NULL;
c4001d92
SP
1418 unsigned long size;
1419 off_t curpos = obj_offset;
21666f1a 1420 enum object_type type;
5db47c2b 1421
21666f1a 1422 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1423
21666f1a 1424 switch (type) {
eb32d236
NP
1425 case OBJ_OFS_DELTA:
1426 case OBJ_REF_DELTA:
21666f1a
NP
1427 type = packed_delta_info(p, &w_curs, curpos,
1428 type, obj_offset, sizep);
2b87c45b 1429 break;
a733cb60 1430 case OBJ_COMMIT:
a733cb60 1431 case OBJ_TREE:
a733cb60 1432 case OBJ_BLOB:
a733cb60 1433 case OBJ_TAG:
2b87c45b
NP
1434 if (sizep)
1435 *sizep = size;
a69d0943 1436 break;
1f688557 1437 default:
08a19d87 1438 die("pack %s contains unknown object type %d",
21666f1a 1439 p->pack_name, type);
1f688557 1440 }
2b87c45b 1441 unuse_pack(&w_curs);
21666f1a 1442 return type;
1f688557
JH
1443}
1444
eb950c19 1445static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1446 struct pack_window **w_curs,
c4001d92 1447 off_t curpos,
eb950c19 1448 unsigned long size)
de530aaa
SP
1449{
1450 int st;
1451 z_stream stream;
079afb18 1452 unsigned char *buffer, *in;
de530aaa
SP
1453
1454 buffer = xmalloc(size + 1);
1455 buffer[size] = 0;
1456 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1457 stream.next_out = buffer;
1458 stream.avail_out = size;
1459
1460 inflateInit(&stream);
079afb18 1461 do {
2b87c45b 1462 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1463 stream.next_in = in;
1464 st = inflate(&stream, Z_FINISH);
2b87c45b 1465 curpos += stream.next_in - in;
079afb18 1466 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1467 inflateEnd(&stream);
1468 if ((st != Z_STREAM_END) || stream.total_out != size) {
1469 free(buffer);
1470 return NULL;
1471 }
1472
1473 return buffer;
1474}
1475
e5e01619
LT
1476#define MAX_DELTA_CACHE (256)
1477
18bdec11 1478static size_t delta_base_cached;
5e08ecbf
NP
1479
1480static struct delta_base_cache_lru_list {
1481 struct delta_base_cache_lru_list *prev;
1482 struct delta_base_cache_lru_list *next;
1483} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1484
e5e01619 1485static struct delta_base_cache_entry {
5e08ecbf
NP
1486 struct delta_base_cache_lru_list lru;
1487 void *data;
e5e01619
LT
1488 struct packed_git *p;
1489 off_t base_offset;
1490 unsigned long size;
e5e01619
LT
1491 enum object_type type;
1492} delta_base_cache[MAX_DELTA_CACHE];
1493
1494static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1495{
1496 unsigned long hash;
1497
1498 hash = (unsigned long)p + (unsigned long)base_offset;
1499 hash += (hash >> 8) + (hash >> 16);
3358004a 1500 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1501}
1502
62f255ad 1503static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1504 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1505{
e5e01619
LT
1506 void *ret;
1507 unsigned long hash = pack_entry_hash(p, base_offset);
1508 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1509
1510 ret = ent->data;
1511 if (ret && ent->p == p && ent->base_offset == base_offset)
1512 goto found_cache_entry;
62f255ad 1513 return unpack_entry(p, base_offset, type, base_size);
e5e01619
LT
1514
1515found_cache_entry:
18bdec11 1516 if (!keep_cache) {
a0cba108 1517 ent->data = NULL;
5e08ecbf
NP
1518 ent->lru.next->prev = ent->lru.prev;
1519 ent->lru.prev->next = ent->lru.next;
18bdec11 1520 delta_base_cached -= ent->size;
182af834
PH
1521 } else {
1522 ret = xmemdupz(ent->data, ent->size);
a0cba108 1523 }
e5e01619
LT
1524 *type = ent->type;
1525 *base_size = ent->size;
1526 return ret;
62f255ad
LT
1527}
1528
18bdec11
SP
1529static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1530{
1531 if (ent->data) {
1532 free(ent->data);
1533 ent->data = NULL;
5e08ecbf
NP
1534 ent->lru.next->prev = ent->lru.prev;
1535 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1536 delta_base_cached -= ent->size;
1537 }
1538}
1539
62f255ad
LT
1540static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1541 void *base, unsigned long base_size, enum object_type type)
1542{
5e08ecbf 1543 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1544 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1545 struct delta_base_cache_lru_list *lru;
e5e01619 1546
18bdec11
SP
1547 release_delta_base_cache(ent);
1548 delta_base_cached += base_size;
5e08ecbf
NP
1549
1550 for (lru = delta_base_cache_lru.next;
1551 delta_base_cached > delta_base_cache_limit
1552 && lru != &delta_base_cache_lru;
1553 lru = lru->next) {
1554 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1555 if (f->type == OBJ_BLOB)
1556 release_delta_base_cache(f);
1557 }
5e08ecbf
NP
1558 for (lru = delta_base_cache_lru.next;
1559 delta_base_cached > delta_base_cache_limit
1560 && lru != &delta_base_cache_lru;
1561 lru = lru->next) {
1562 struct delta_base_cache_entry *f = (void *)lru;
1563 release_delta_base_cache(f);
1564 }
18bdec11 1565
e5e01619
LT
1566 ent->p = p;
1567 ent->base_offset = base_offset;
1568 ent->type = type;
1569 ent->data = base;
1570 ent->size = base_size;
5e08ecbf
NP
1571 ent->lru.next = &delta_base_cache_lru;
1572 ent->lru.prev = delta_base_cache_lru.prev;
1573 delta_base_cache_lru.prev->next = &ent->lru;
1574 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1575}
1576
eb950c19 1577static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1578 struct pack_window **w_curs,
c4001d92 1579 off_t curpos,
1f688557 1580 unsigned long delta_size,
c4001d92 1581 off_t obj_offset,
21666f1a 1582 enum object_type *type,
eb950c19 1583 unsigned long *sizep)
1f688557 1584{
7c3e8be3 1585 void *delta_data, *result, *base;
c4001d92
SP
1586 unsigned long base_size;
1587 off_t base_offset;
43057304 1588
21666f1a 1589 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
a0cba108 1590 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
67686d95 1591 if (!base)
c4001d92
SP
1592 die("failed to read delta base object"
1593 " at %"PRIuMAX" from %s",
1594 (uintmax_t)base_offset, p->pack_name);
67686d95 1595
2b87c45b 1596 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
9064d87b
SP
1597 if (!delta_data)
1598 die("failed to unpack compressed delta"
1599 " at %"PRIuMAX" from %s",
1600 (uintmax_t)curpos, p->pack_name);
1f688557
JH
1601 result = patch_delta(base, base_size,
1602 delta_data, delta_size,
21666f1a 1603 sizep);
1f688557
JH
1604 if (!result)
1605 die("failed to apply delta");
1606 free(delta_data);
62f255ad 1607 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1608 return result;
1609}
1610
c4001d92 1611void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1612 enum object_type *type, unsigned long *sizep)
1f688557 1613{
03e79c88 1614 struct pack_window *w_curs = NULL;
c4001d92 1615 off_t curpos = obj_offset;
21666f1a 1616 void *data;
1f688557 1617
21666f1a
NP
1618 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1619 switch (*type) {
eb32d236
NP
1620 case OBJ_OFS_DELTA:
1621 case OBJ_REF_DELTA:
21666f1a
NP
1622 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1623 obj_offset, type, sizep);
4d703a1a 1624 break;
a733cb60 1625 case OBJ_COMMIT:
a733cb60 1626 case OBJ_TREE:
a733cb60 1627 case OBJ_BLOB:
a733cb60 1628 case OBJ_TAG:
21666f1a 1629 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1630 break;
1f688557 1631 default:
21666f1a 1632 die("unknown object type %i in %s", *type, p->pack_name);
1f688557 1633 }
03e79c88 1634 unuse_pack(&w_curs);
21666f1a 1635 return data;
1f688557
JH
1636}
1637
d079837e 1638const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1639 uint32_t n)
9a217f2a 1640{
42873078 1641 const unsigned char *index = p->index_data;
d079837e
SP
1642 if (!index) {
1643 if (open_pack_index(p))
1644 return NULL;
1645 index = p->index_data;
1646 }
57059091 1647 if (n >= p->num_objects)
d72308e0 1648 return NULL;
74e34e1f
NP
1649 index += 4 * 256;
1650 if (p->index_version == 1) {
1651 return index + 24 * n + 4;
1652 } else {
1653 index += 8;
1654 return index + 20 * n;
1655 }
1656}
1657
1658static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1659{
1660 const unsigned char *index = p->index_data;
1661 index += 4 * 256;
1662 if (p->index_version == 1) {
1663 return ntohl(*((uint32_t *)(index + 24 * n)));
1664 } else {
1665 uint32_t off;
1666 index += 8 + p->num_objects * (20 + 4);
1667 off = ntohl(*((uint32_t *)(index + 4 * n)));
1668 if (!(off & 0x80000000))
1669 return off;
1670 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1671 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1672 ntohl(*((uint32_t *)(index + 4)));
1673 }
9a217f2a
JH
1674}
1675
c4001d92 1676off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1677 struct packed_git *p)
1f688557 1678{
42873078 1679 const uint32_t *level1_ofs = p->index_data;
42873078 1680 const unsigned char *index = p->index_data;
628522ec
JH
1681 unsigned hi, lo, stride;
1682 static int use_lookup = -1;
1683 static int debug_lookup = -1;
1684
1685 if (debug_lookup < 0)
1686 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1687
d079837e
SP
1688 if (!index) {
1689 if (open_pack_index(p))
1690 return 0;
1691 level1_ofs = p->index_data;
1692 index = p->index_data;
1693 }
74e34e1f
NP
1694 if (p->index_version > 1) {
1695 level1_ofs += 2;
1696 index += 8;
1697 }
42873078 1698 index += 4 * 256;
74e34e1f
NP
1699 hi = ntohl(level1_ofs[*sha1]);
1700 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
1701 if (p->index_version > 1) {
1702 stride = 20;
1703 } else {
1704 stride = 24;
1705 index += 4;
1706 }
1707
1708 if (debug_lookup)
1709 printf("%02x%02x%02x... lo %u hi %u nr %u\n",
1710 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1711
1712 if (use_lookup < 0)
1713 use_lookup = !!getenv("GIT_USE_LOOKUP");
1714 if (use_lookup) {
1715 int pos = sha1_entry_pos(index, stride, 0,
1716 lo, hi, p->num_objects, sha1);
1717 if (pos < 0)
1718 return 0;
1719 return nth_packed_object_offset(p, pos);
1720 }
1f688557
JH
1721
1722 do {
74e34e1f 1723 unsigned mi = (lo + hi) / 2;
628522ec
JH
1724 int cmp = hashcmp(index + mi * stride, sha1);
1725
1726 if (debug_lookup)
1727 printf("lo %u hi %u rg %u mi %u\n",
1728 lo, hi, hi - lo, mi);
43057304 1729 if (!cmp)
74e34e1f 1730 return nth_packed_object_offset(p, mi);
1f688557
JH
1731 if (cmp > 0)
1732 hi = mi;
1733 else
1734 lo = mi+1;
1735 } while (lo < hi);
1736 return 0;
1737}
1738
000dfd3f 1739int matches_pack_name(struct packed_git *p, const char *name)
d4ff6d92
SP
1740{
1741 const char *last_c, *c;
1742
000dfd3f
JH
1743 if (!strcmp(p->pack_name, name))
1744 return 1;
d4ff6d92
SP
1745
1746 for (c = p->pack_name, last_c = c; *c;)
1747 if (*c == '/')
1748 last_c = ++c;
1749 else
1750 ++c;
000dfd3f
JH
1751 if (!strcmp(last_c, name))
1752 return 1;
d4ff6d92 1753
000dfd3f 1754 return 0;
d4ff6d92
SP
1755}
1756
106d710b 1757static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1758{
f7c22cc6 1759 static struct packed_git *last_found = (void *)1;
1f688557 1760 struct packed_git *p;
c4001d92 1761 off_t offset;
43057304 1762
1f688557 1763 prepare_packed_git();
f7c22cc6
NP
1764 if (!packed_git)
1765 return 0;
1766 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1767
f7c22cc6 1768 do {
106d710b
JH
1769 if (ignore_packed) {
1770 const char **ig;
1771 for (ig = ignore_packed; *ig; ig++)
000dfd3f 1772 if (matches_pack_name(p, *ig))
106d710b
JH
1773 break;
1774 if (*ig)
f7c22cc6 1775 goto next;
106d710b 1776 }
f7c22cc6 1777
43057304
NP
1778 offset = find_pack_entry_one(sha1, p);
1779 if (offset) {
c715f783
SP
1780 /*
1781 * We are about to tell the caller where they can
1782 * locate the requested object. We better make
1783 * sure the packfile is still here and can be
1784 * accessed before supplying that answer, as
1785 * it may have been deleted since the index
1786 * was loaded!
1787 */
1788 if (p->pack_fd == -1 && open_packed_git(p)) {
1789 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1790 goto next;
c715f783 1791 }
43057304
NP
1792 e->offset = offset;
1793 e->p = p;
1794 hashcpy(e->sha1, sha1);
f7c22cc6 1795 last_found = p;
1f688557 1796 return 1;
43057304 1797 }
f7c22cc6
NP
1798
1799 next:
1800 if (p == last_found)
1801 p = packed_git;
1802 else
1803 p = p->next;
1804 if (p == last_found)
1805 p = p->next;
1806 } while (p);
1f688557
JH
1807 return 0;
1808}
1809
a6080a0a 1810struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1811 struct packed_git *packs)
1812{
1813 struct packed_git *p;
bf592c50
DB
1814
1815 for (p = packs; p; p = p->next) {
43057304 1816 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1817 return p;
1818 }
1819 return NULL;
21666f1a 1820
bf592c50
DB
1821}
1822
21666f1a 1823static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1824{
36e4d74a 1825 int status;
65c2e0c3
JH
1826 unsigned long mapsize, size;
1827 void *map;
1828 z_stream stream;
d65a16f6 1829 char hdr[32];
65c2e0c3 1830
bb6b8e4f 1831 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1832 if (!map)
1833 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1834 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1835 status = error("unable to unpack %s header",
1836 sha1_to_hex(sha1));
21666f1a 1837 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1838 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1839 else if (sizep)
1840 *sizep = size;
65c2e0c3
JH
1841 inflateEnd(&stream);
1842 munmap(map, mapsize);
1843 return status;
1844}
1845
21666f1a 1846int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1847{
f0df4ed5
JS
1848 struct pack_entry e;
1849
1850 if (!find_pack_entry(sha1, &e, NULL)) {
1851 reprepare_packed_git();
1852 if (!find_pack_entry(sha1, &e, NULL))
21666f1a 1853 return sha1_loose_object_info(sha1, sizep);
f0df4ed5 1854 }
21666f1a 1855 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1856}
1857
21666f1a
NP
1858static void *read_packed_sha1(const unsigned char *sha1,
1859 enum object_type *type, unsigned long *size)
1f688557
JH
1860{
1861 struct pack_entry e;
1862
8276c007 1863 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1864 return NULL;
8276c007 1865 else
a0cba108 1866 return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1f688557
JH
1867}
1868
d66b37bb
JH
1869/*
1870 * This is meant to hold a *small* number of objects that you would
1871 * want read_sha1_file() to be able to return, but yet you do not want
1872 * to write them into the object store (e.g. a browse-only
1873 * application).
1874 */
1875static struct cached_object {
1876 unsigned char sha1[20];
21666f1a 1877 enum object_type type;
d66b37bb
JH
1878 void *buf;
1879 unsigned long size;
1880} *cached_objects;
1881static int cached_object_nr, cached_object_alloc;
1882
346245a1
JK
1883static struct cached_object empty_tree = {
1884 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
1885 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
1886 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
1887 OBJ_TREE,
1888 "",
1889 0
1890};
1891
d66b37bb
JH
1892static struct cached_object *find_cached_object(const unsigned char *sha1)
1893{
1894 int i;
1895 struct cached_object *co = cached_objects;
1896
1897 for (i = 0; i < cached_object_nr; i++, co++) {
1898 if (!hashcmp(co->sha1, sha1))
1899 return co;
1900 }
346245a1
JK
1901 if (!hashcmp(sha1, empty_tree.sha1))
1902 return &empty_tree;
d66b37bb
JH
1903 return NULL;
1904}
1905
21666f1a
NP
1906int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1907 unsigned char *sha1)
d66b37bb
JH
1908{
1909 struct cached_object *co;
1910
21666f1a 1911 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
1912 if (has_sha1_file(sha1) || find_cached_object(sha1))
1913 return 0;
1914 if (cached_object_alloc <= cached_object_nr) {
1915 cached_object_alloc = alloc_nr(cached_object_alloc);
1916 cached_objects = xrealloc(cached_objects,
1917 sizeof(*cached_objects) *
1918 cached_object_alloc);
1919 }
1920 co = &cached_objects[cached_object_nr++];
1921 co->size = len;
21666f1a 1922 co->type = type;
efa13f7b
JH
1923 co->buf = xmalloc(len);
1924 memcpy(co->buf, buf, len);
d66b37bb
JH
1925 hashcpy(co->sha1, sha1);
1926 return 0;
1927}
1928
21666f1a
NP
1929void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
1930 unsigned long *size)
0fcfd160
LT
1931{
1932 unsigned long mapsize;
1933 void *map, *buf;
d66b37bb
JH
1934 struct cached_object *co;
1935
1936 co = find_cached_object(sha1);
1937 if (co) {
21666f1a 1938 *type = co->type;
d66b37bb 1939 *size = co->size;
182af834 1940 return xmemdupz(co->buf, co->size);
d66b37bb 1941 }
0fcfd160 1942
8276c007
PE
1943 buf = read_packed_sha1(sha1, type, size);
1944 if (buf)
1945 return buf;
bb6b8e4f 1946 map = map_sha1_file(sha1, &mapsize);
0fcfd160 1947 if (map) {
7efbff75 1948 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
1949 munmap(map, mapsize);
1950 return buf;
1951 }
637cdd9d 1952 reprepare_packed_git();
8276c007 1953 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
1954}
1955
40469ee9 1956void *read_object_with_reference(const unsigned char *sha1,
21666f1a 1957 const char *required_type_name,
40469ee9
JH
1958 unsigned long *size,
1959 unsigned char *actual_sha1_return)
f4913f91 1960{
21666f1a 1961 enum object_type type, required_type;
f4913f91
JH
1962 void *buffer;
1963 unsigned long isize;
40469ee9 1964 unsigned char actual_sha1[20];
f4913f91 1965
21666f1a 1966 required_type = type_from_string(required_type_name);
e702496e 1967 hashcpy(actual_sha1, sha1);
40469ee9
JH
1968 while (1) {
1969 int ref_length = -1;
1970 const char *ref_type = NULL;
f4913f91 1971
21666f1a 1972 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
1973 if (!buffer)
1974 return NULL;
21666f1a 1975 if (type == required_type) {
40469ee9
JH
1976 *size = isize;
1977 if (actual_sha1_return)
e702496e 1978 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1979 return buffer;
1980 }
1981 /* Handle references */
21666f1a 1982 else if (type == OBJ_COMMIT)
40469ee9 1983 ref_type = "tree ";
21666f1a 1984 else if (type == OBJ_TAG)
40469ee9
JH
1985 ref_type = "object ";
1986 else {
1987 free(buffer);
1988 return NULL;
1989 }
1990 ref_length = strlen(ref_type);
f4913f91 1991
50974ec9
MK
1992 if (ref_length + 40 > isize ||
1993 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1994 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1995 free(buffer);
1996 return NULL;
1997 }
1cf58e72 1998 free(buffer);
40469ee9
JH
1999 /* Now we have the ID of the referred-to object in
2000 * actual_sha1. Check again. */
f4913f91 2001 }
f4913f91
JH
2002}
2003
ce9fbf16 2004static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2005 const char *type, unsigned char *sha1,
d65a16f6 2006 char *hdr, int *hdrlen)
d410c0f5
JH
2007{
2008 SHA_CTX c;
2009
2010 /* Generate the header */
d65a16f6 2011 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2012
2013 /* Sha1.. */
2014 SHA1_Init(&c);
2015 SHA1_Update(&c, hdr, *hdrlen);
2016 SHA1_Update(&c, buf, len);
2017 SHA1_Final(sha1, &c);
d410c0f5
JH
2018}
2019
230f1322
LT
2020/*
2021 * Link the tempfile to the final place, possibly creating the
2022 * last directory level as you do so.
2023 *
2024 * Returns the errno on failure, 0 on success.
2025 */
839837b9 2026static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
2027{
2028 int ret;
756aaf4a 2029 char *dir;
230f1322
LT
2030
2031 if (!link(tmpfile, filename))
2032 return 0;
2033
2034 /*
756aaf4a 2035 * Try to mkdir the last path component if that failed.
230f1322
LT
2036 *
2037 * Re-try the "link()" regardless of whether the mkdir
2038 * succeeds, since a race might mean that somebody
2039 * else succeeded.
2040 */
2041 ret = errno;
756aaf4a
SP
2042 dir = strrchr(filename, '/');
2043 if (dir) {
2044 *dir = 0;
866cae0d 2045 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
91c23e48 2046 *dir = '/';
756aaf4a 2047 return -2;
91c23e48 2048 }
756aaf4a
SP
2049 *dir = '/';
2050 if (!link(tmpfile, filename))
2051 return 0;
2052 ret = errno;
230f1322
LT
2053 }
2054 return ret;
2055}
2056
2057/*
2058 * Move the just written object into its final resting place
2059 */
839837b9 2060int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
2061{
2062 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
2063
2064 /*
2065 * Coda hack - coda doesn't like cross-directory links,
2066 * so we fall back to a rename, which will mean that it
2067 * won't be able to check collisions, but that's not a
2068 * big deal.
2069 *
2070 * The same holds for FAT formatted media.
2071 *
2072 * When this succeeds, we just return 0. We have nothing
2073 * left to unlink.
2074 */
2075 if (ret && ret != EEXIST) {
2076 if (!rename(tmpfile, filename))
230f1322 2077 return 0;
9e48b389 2078 ret = errno;
230f1322
LT
2079 }
2080 unlink(tmpfile);
2081 if (ret) {
2082 if (ret != EEXIST) {
916d081b 2083 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2084 }
2085 /* FIXME!!! Collision check here ? */
2086 }
2087
2088 return 0;
2089}
2090
4d548150
LT
2091static int write_buffer(int fd, const void *buf, size_t len)
2092{
d34cf19b 2093 if (write_in_full(fd, buf, len) < 0)
93822c22 2094 return error("file write error (%s)", strerror(errno));
4d548150
LT
2095 return 0;
2096}
2097
ce9fbf16 2098int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2099 unsigned char *sha1)
2100{
d65a16f6 2101 char hdr[32];
abdc3fc8
RS
2102 int hdrlen;
2103 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2104 return 0;
2105}
2106
bbac7311
NP
2107static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2108 void *buf, unsigned long len, time_t mtime)
0fcfd160 2109{
bbac7311 2110 int fd, size, ret;
bf0f910d 2111 unsigned char *compressed;
0fcfd160 2112 z_stream stream;
706bc531 2113 char *filename;
aac17941 2114 static char tmpfile[PATH_MAX];
a44c9a5e 2115
972a9155 2116 filename = sha1_file_name(sha1);
aac17941
LT
2117 fd = open(filename, O_RDONLY);
2118 if (fd >= 0) {
706bc531 2119 /*
aac17941
LT
2120 * FIXME!!! We might do collision checking here, but we'd
2121 * need to uncompress the old file and check it. Later.
706bc531 2122 */
aac17941 2123 close(fd);
706bc531
LT
2124 return 0;
2125 }
2126
aac17941 2127 if (errno != ENOENT) {
916d081b 2128 return error("sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
2129 }
2130
0e55181f 2131 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
ace1534d 2132
aac17941
LT
2133 fd = mkstemp(tmpfile);
2134 if (fd < 0) {
916d081b
PB
2135 if (errno == EPERM)
2136 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2137 else
2138 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2139 }
2140
0fcfd160
LT
2141 /* Set it up */
2142 memset(&stream, 0, sizeof(stream));
12f6c308 2143 deflateInit(&stream, zlib_compression_level);
93821bd9 2144 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2145 compressed = xmalloc(size);
0fcfd160
LT
2146
2147 /* Compress it */
0fcfd160
LT
2148 stream.next_out = compressed;
2149 stream.avail_out = size;
a44c9a5e
LT
2150
2151 /* First header.. */
d65a16f6 2152 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2153 stream.avail_in = hdrlen;
726f852b
NP
2154 while (deflate(&stream, 0) == Z_OK)
2155 /* nothing */;
a44c9a5e
LT
2156
2157 /* Then the data itself.. */
2158 stream.next_in = buf;
2159 stream.avail_in = len;
ac54c277
LT
2160 ret = deflate(&stream, Z_FINISH);
2161 if (ret != Z_STREAM_END)
2162 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2163
2164 ret = deflateEnd(&stream);
2165 if (ret != Z_OK)
2166 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2167
0fcfd160
LT
2168 size = stream.total_out;
2169
4d548150
LT
2170 if (write_buffer(fd, compressed, size) < 0)
2171 die("unable to write sha1 file");
aac17941 2172 fchmod(fd, 0444);
e82973cf
JH
2173 if (close(fd))
2174 die("unable to write sha1 file");
383f85b7 2175 free(compressed);
0fcfd160 2176
bbac7311
NP
2177 if (mtime) {
2178 struct utimbuf utb;
2179 utb.actime = mtime;
2180 utb.modtime = mtime;
2181 if (utime(tmpfile, &utb) < 0)
2182 warning("failed utime() on %s: %s",
2183 tmpfile, strerror(errno));
2184 }
2185
230f1322 2186 return move_temp_to_file(tmpfile, filename);
0fcfd160 2187}
8237b185 2188
bbac7311
NP
2189int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2190{
2191 unsigned char sha1[20];
2192 char hdr[32];
2193 int hdrlen;
2194
2195 /* Normally if we have it in the pack then we do not bother writing
2196 * it out into .git/objects/??/?{38} file.
2197 */
2198 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2199 if (returnsha1)
2200 hashcpy(returnsha1, sha1);
2201 if (has_sha1_file(sha1))
2202 return 0;
2203 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2204}
2205
2206int force_object_loose(const unsigned char *sha1, time_t mtime)
2207{
2208 struct stat st;
2209 void *buf;
2210 unsigned long len;
2211 enum object_type type;
2212 char hdr[32];
2213 int hdrlen;
2214
2215 if (find_sha1_file(sha1, &st))
2216 return 0;
2217 buf = read_packed_sha1(sha1, &type, &len);
2218 if (!buf)
2219 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2220 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
2221 return write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2222}
2223
4d548150
LT
2224/*
2225 * We need to unpack and recompress the object for writing
2226 * it out to a different file.
2227 */
2228static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 2229{
4d548150 2230 size_t size;
a5eda52b 2231 z_stream stream;
4d548150
LT
2232 unsigned char *unpacked;
2233 unsigned long len;
21666f1a 2234 enum object_type type;
d65a16f6 2235 char hdr[32];
4d548150
LT
2236 int hdrlen;
2237 void *buf;
bfc66daf 2238
a9486b02 2239 /* need to unpack and recompress it by itself */
21666f1a 2240 unpacked = read_packed_sha1(sha1, &type, &len);
8276c007
PE
2241 if (!unpacked)
2242 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
a5eda52b 2243
21666f1a 2244 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
a5eda52b 2245
4d548150
LT
2246 /* Set it up */
2247 memset(&stream, 0, sizeof(stream));
12f6c308 2248 deflateInit(&stream, zlib_compression_level);
4d548150
LT
2249 size = deflateBound(&stream, len + hdrlen);
2250 buf = xmalloc(size);
a5eda52b 2251
4d548150
LT
2252 /* Compress it */
2253 stream.next_out = buf;
2254 stream.avail_out = size;
a5eda52b 2255
4d548150
LT
2256 /* First header.. */
2257 stream.next_in = (void *)hdr;
2258 stream.avail_in = hdrlen;
2259 while (deflate(&stream, 0) == Z_OK)
2260 /* nothing */;
bfc66daf 2261
4d548150
LT
2262 /* Then the data itself.. */
2263 stream.next_in = unpacked;
2264 stream.avail_in = len;
2265 while (deflate(&stream, Z_FINISH) == Z_OK)
2266 /* nothing */;
2267 deflateEnd(&stream);
2268 free(unpacked);
bfc66daf 2269
4d548150
LT
2270 *objsize = stream.total_out;
2271 return buf;
2272}
2273
2274int write_sha1_to_fd(int fd, const unsigned char *sha1)
2275{
2276 int retval;
2277 unsigned long objsize;
bb6b8e4f 2278 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
2279
2280 if (buf) {
2281 retval = write_buffer(fd, buf, objsize);
2282 munmap(buf, objsize);
2283 return retval;
2284 }
2285
2286 buf = repack_object(sha1, &objsize);
2287 retval = write_buffer(fd, buf, objsize);
2288 free(buf);
2289 return retval;
a5eda52b
DB
2290}
2291
70b9829e
DB
2292int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
2293 size_t bufsize, size_t *bufposn)
8237b185 2294{
230f1322 2295 char tmpfile[PATH_MAX];
8237b185
DB
2296 int local;
2297 z_stream stream;
2298 unsigned char real_sha1[20];
bf0f910d 2299 unsigned char discard[4096];
8237b185
DB
2300 int ret;
2301 SHA_CTX c;
2302
0e55181f 2303 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
8237b185 2304
230f1322 2305 local = mkstemp(tmpfile);
916d081b
PB
2306 if (local < 0) {
2307 if (errno == EPERM)
2308 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2309 else
2310 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2311 }
8237b185
DB
2312
2313 memset(&stream, 0, sizeof(stream));
2314
2315 inflateInit(&stream);
2316
2317 SHA1_Init(&c);
2318
2319 do {
2320 ssize_t size;
70b9829e
DB
2321 if (*bufposn) {
2322 stream.avail_in = *bufposn;
96ad15ae 2323 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
2324 do {
2325 stream.next_out = discard;
2326 stream.avail_out = sizeof(discard);
2327 ret = inflate(&stream, Z_SYNC_FLUSH);
2328 SHA1_Update(&c, discard, sizeof(discard) -
2329 stream.avail_out);
2330 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
2331 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
2332 die("unable to write sha1 file");
70b9829e
DB
2333 memmove(buffer, buffer + *bufposn - stream.avail_in,
2334 stream.avail_in);
2335 *bufposn = stream.avail_in;
2336 if (ret != Z_OK)
2337 break;
2338 }
93d26e4c 2339 size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
2340 if (size <= 0) {
2341 close(local);
230f1322 2342 unlink(tmpfile);
8237b185
DB
2343 if (!size)
2344 return error("Connection closed?");
2345 perror("Reading from connection");
2346 return -1;
2347 }
70b9829e
DB
2348 *bufposn += size;
2349 } while (1);
8237b185
DB
2350 inflateEnd(&stream);
2351
b5b8d814 2352 fchmod(local, 0444);
0d315468
JM
2353 if (close(local) != 0)
2354 die("unable to write sha1 file");
8237b185
DB
2355 SHA1_Final(real_sha1, &c);
2356 if (ret != Z_STREAM_END) {
230f1322 2357 unlink(tmpfile);
8237b185
DB
2358 return error("File %s corrupted", sha1_to_hex(sha1));
2359 }
a89fccd2 2360 if (hashcmp(sha1, real_sha1)) {
230f1322 2361 unlink(tmpfile);
bd2afde8 2362 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 2363 }
230f1322
LT
2364
2365 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
2366}
2367
bf592c50
DB
2368int has_pack_index(const unsigned char *sha1)
2369{
2370 struct stat st;
2371 if (stat(sha1_pack_index_name(sha1), &st))
2372 return 0;
2373 return 1;
2374}
2375
2376int has_pack_file(const unsigned char *sha1)
2377{
2378 struct stat st;
2379 if (stat(sha1_pack_name(sha1), &st))
2380 return 0;
2381 return 1;
2382}
2383
106d710b 2384int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2385{
2386 struct pack_entry e;
106d710b 2387 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2388}
2389
8237b185
DB
2390int has_sha1_file(const unsigned char *sha1)
2391{
8237b185 2392 struct stat st;
1f688557
JH
2393 struct pack_entry e;
2394
106d710b 2395 if (find_pack_entry(sha1, &e, NULL))
1f688557 2396 return 1;
ab90ea5d 2397 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 2398}
74400e71 2399
e7332f96
BE
2400int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2401{
fd17f5b5 2402 struct strbuf buf;
e7332f96 2403 int ret;
e7332f96 2404
fd17f5b5
PH
2405 strbuf_init(&buf, 0);
2406 if (strbuf_read(&buf, fd, 4096) < 0) {
2407 strbuf_release(&buf);
024510c8
DB
2408 return -1;
2409 }
e7332f96 2410
024510c8 2411 if (!type)
8e440259 2412 type = blob_type;
024510c8 2413 if (write_object)
fd17f5b5 2414 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
abdc3fc8 2415 else
fd17f5b5
PH
2416 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
2417 strbuf_release(&buf);
2418
024510c8
DB
2419 return ret;
2420}
2421
edaec3fb 2422int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
53bca91a 2423 enum object_type type, const char *path)
74400e71 2424{
dc49cd76 2425 size_t size = xsize_t(st->st_size);
3a55602e 2426 void *buf = NULL;
6c510bee 2427 int ret, re_allocated = 0;
74400e71 2428
74400e71 2429 if (size)
c4712e45 2430 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 2431 close(fd);
74400e71 2432
7672db20 2433 if (!type)
edaec3fb 2434 type = OBJ_BLOB;
6c510bee
LT
2435
2436 /*
2437 * Convert blobs to git internal format
2438 */
d0d8e14d 2439 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
5ecd293d
PH
2440 struct strbuf nbuf;
2441 strbuf_init(&nbuf, 0);
21e5ad50
SP
2442 if (convert_to_git(path, buf, size, &nbuf,
2443 write_object ? safe_crlf : 0)) {
ac78e548 2444 munmap(buf, size);
b315c5c0 2445 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2446 re_allocated = 1;
2447 }
2448 }
2449
7672db20 2450 if (write_object)
edaec3fb 2451 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2452 else
edaec3fb 2453 ret = hash_sha1_file(buf, size, typename(type), sha1);
6c510bee
LT
2454 if (re_allocated) {
2455 free(buf);
2456 return ret;
2457 }
aac17941
LT
2458 if (size)
2459 munmap(buf, size);
2460 return ret;
74400e71 2461}
ec1fcc16
JH
2462
2463int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2464{
2465 int fd;
2466 char *target;
dc49cd76 2467 size_t len;
ec1fcc16
JH
2468
2469 switch (st->st_mode & S_IFMT) {
2470 case S_IFREG:
2471 fd = open(path, O_RDONLY);
2472 if (fd < 0)
2473 return error("open(\"%s\"): %s", path,
2474 strerror(errno));
53bca91a 2475 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2476 return error("%s: failed to insert into database",
2477 path);
2478 break;
2479 case S_IFLNK:
dc49cd76
SP
2480 len = xsize_t(st->st_size);
2481 target = xmalloc(len + 1);
2482 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2483 char *errstr = strerror(errno);
2484 free(target);
2485 return error("readlink(\"%s\"): %s", path,
2486 errstr);
2487 }
abdc3fc8 2488 if (!write_object)
dc49cd76
SP
2489 hash_sha1_file(target, len, blob_type, sha1);
2490 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2491 return error("%s: failed to insert into database",
2492 path);
2493 free(target);
2494 break;
f35a6d3b
LT
2495 case S_IFDIR:
2496 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2497 default:
2498 return error("%s: unsupported file type", path);
2499 }
2500 return 0;
2501}
a69e5429
JH
2502
2503int read_pack_header(int fd, struct pack_header *header)
2504{
c697ad14
HO
2505 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2506 /* "eof before pack header was fully read" */
2507 return PH_ERROR_EOF;
2508
a69e5429
JH
2509 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2510 /* "protocol error (pack signature mismatch detected)" */
2511 return PH_ERROR_PACK_SIGNATURE;
2512 if (!pack_version_ok(header->hdr_version))
2513 /* "protocol error (pack version unsupported)" */
2514 return PH_ERROR_PROTOCOL;
2515 return 0;
2516}