make verify_one_pack() a bit less wrong wrt packed_git structure
[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"
0fcfd160 17
144bde78
LT
18#ifndef O_NOATIME
19#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
20#define O_NOATIME 01000000
21#else
22#define O_NOATIME 0
23#endif
24#endif
25
e05db0fd
PR
26#ifdef NO_C99_FORMAT
27#define SZ_FMT "lu"
9e42d6a1 28static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
e05db0fd
PR
29#else
30#define SZ_FMT "zu"
9e42d6a1 31static size_t sz_fmt(size_t s) { return s; }
e05db0fd
PR
32#endif
33
96f1e58f 34const unsigned char null_sha1[20];
88cd621d 35
144bde78
LT
36static unsigned int sha1_file_open_flag = O_NOATIME;
37
192a6be2 38const signed char hexval_table[256] = {
e49521b5
JH
39 -1, -1, -1, -1, -1, -1, -1, -1, /* 00-07 */
40 -1, -1, -1, -1, -1, -1, -1, -1, /* 08-0f */
41 -1, -1, -1, -1, -1, -1, -1, -1, /* 10-17 */
42 -1, -1, -1, -1, -1, -1, -1, -1, /* 18-1f */
43 -1, -1, -1, -1, -1, -1, -1, -1, /* 20-27 */
44 -1, -1, -1, -1, -1, -1, -1, -1, /* 28-2f */
45 0, 1, 2, 3, 4, 5, 6, 7, /* 30-37 */
46 8, 9, -1, -1, -1, -1, -1, -1, /* 38-3f */
47 -1, 10, 11, 12, 13, 14, 15, -1, /* 40-47 */
48 -1, -1, -1, -1, -1, -1, -1, -1, /* 48-4f */
49 -1, -1, -1, -1, -1, -1, -1, -1, /* 50-57 */
50 -1, -1, -1, -1, -1, -1, -1, -1, /* 58-5f */
51 -1, 10, 11, 12, 13, 14, 15, -1, /* 60-67 */
52 -1, -1, -1, -1, -1, -1, -1, -1, /* 68-67 */
53 -1, -1, -1, -1, -1, -1, -1, -1, /* 70-77 */
54 -1, -1, -1, -1, -1, -1, -1, -1, /* 78-7f */
55 -1, -1, -1, -1, -1, -1, -1, -1, /* 80-87 */
56 -1, -1, -1, -1, -1, -1, -1, -1, /* 88-8f */
57 -1, -1, -1, -1, -1, -1, -1, -1, /* 90-97 */
58 -1, -1, -1, -1, -1, -1, -1, -1, /* 98-9f */
59 -1, -1, -1, -1, -1, -1, -1, -1, /* a0-a7 */
60 -1, -1, -1, -1, -1, -1, -1, -1, /* a8-af */
61 -1, -1, -1, -1, -1, -1, -1, -1, /* b0-b7 */
62 -1, -1, -1, -1, -1, -1, -1, -1, /* b8-bf */
63 -1, -1, -1, -1, -1, -1, -1, -1, /* c0-c7 */
64 -1, -1, -1, -1, -1, -1, -1, -1, /* c8-cf */
65 -1, -1, -1, -1, -1, -1, -1, -1, /* d0-d7 */
66 -1, -1, -1, -1, -1, -1, -1, -1, /* d8-df */
67 -1, -1, -1, -1, -1, -1, -1, -1, /* e0-e7 */
68 -1, -1, -1, -1, -1, -1, -1, -1, /* e8-ef */
69 -1, -1, -1, -1, -1, -1, -1, -1, /* f0-f7 */
70 -1, -1, -1, -1, -1, -1, -1, -1, /* f8-ff */
71};
0fcfd160
LT
72
73int get_sha1_hex(const char *hex, unsigned char *sha1)
74{
75 int i;
76 for (i = 0; i < 20; i++) {
77 unsigned int val = (hexval(hex[0]) << 4) | hexval(hex[1]);
78 if (val & ~0xff)
79 return -1;
80 *sha1++ = val;
81 hex += 2;
82 }
83 return 0;
84}
85
b2cb9425
JH
86int safe_create_leading_directories(char *path)
87{
88 char *pos = path;
67d42212
JR
89 struct stat st;
90
85dadc38 91 if (is_absolute_path(path))
67ffdf4c 92 pos++;
b2cb9425
JH
93
94 while (pos) {
95 pos = strchr(pos, '/');
96 if (!pos)
97 break;
98 *pos = 0;
67d42212
JR
99 if (!stat(path, &st)) {
100 /* path exists */
101 if (!S_ISDIR(st.st_mode)) {
b2cb9425 102 *pos = '/';
67d42212 103 return -3;
b2cb9425 104 }
457f06d6 105 }
67d42212
JR
106 else if (mkdir(path, 0777)) {
107 *pos = '/';
108 return -1;
109 }
457f06d6
JS
110 else if (adjust_shared_perm(path)) {
111 *pos = '/';
112 return -2;
113 }
b2cb9425
JH
114 *pos++ = '/';
115 }
116 return 0;
117}
723c31fe 118
0fcfd160
LT
119char * sha1_to_hex(const unsigned char *sha1)
120{
dcb3450f
LT
121 static int bufno;
122 static char hexbuffer[4][50];
0fcfd160 123 static const char hex[] = "0123456789abcdef";
dcb3450f 124 char *buffer = hexbuffer[3 & ++bufno], *buf = buffer;
0fcfd160
LT
125 int i;
126
127 for (i = 0; i < 20; i++) {
128 unsigned int val = *sha1++;
129 *buf++ = hex[val >> 4];
130 *buf++ = hex[val & 0xf];
131 }
1e80e044
JS
132 *buf = '\0';
133
0fcfd160
LT
134 return buffer;
135}
136
ace1534d
JH
137static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
138{
139 int i;
140 for (i = 0; i < 20; i++) {
141 static char hex[] = "0123456789abcdef";
142 unsigned int val = sha1[i];
143 char *pos = pathbuf + i*2 + (i > 0);
144 *pos++ = hex[val >> 4];
145 *pos = hex[val & 0xf];
146 }
147}
148
0fcfd160
LT
149/*
150 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 151 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 152 * filename.
ace1534d
JH
153 *
154 * Also note that this returns the location for creating. Reading
155 * SHA1 file can happen from any alternate directory listed in the
d19938ab 156 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 157 * the primary object database.
0fcfd160
LT
158 */
159char *sha1_file_name(const unsigned char *sha1)
160{
0fcfd160
LT
161 static char *name, *base;
162
163 if (!base) {
d19938ab 164 const char *sha1_file_directory = get_object_directory();
0fcfd160 165 int len = strlen(sha1_file_directory);
812666c8 166 base = xmalloc(len + 60);
0fcfd160
LT
167 memcpy(base, sha1_file_directory, len);
168 memset(base+len, 0, 60);
169 base[len] = '/';
170 base[len+3] = '/';
171 name = base + len + 1;
172 }
ace1534d 173 fill_sha1_path(name, sha1);
0fcfd160
LT
174 return base;
175}
176
bf592c50
DB
177char *sha1_pack_name(const unsigned char *sha1)
178{
179 static const char hex[] = "0123456789abcdef";
180 static char *name, *base, *buf;
181 int i;
182
183 if (!base) {
184 const char *sha1_file_directory = get_object_directory();
185 int len = strlen(sha1_file_directory);
186 base = xmalloc(len + 60);
187 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.pack", sha1_file_directory);
188 name = base + len + 11;
189 }
190
191 buf = name;
192
193 for (i = 0; i < 20; i++) {
194 unsigned int val = *sha1++;
195 *buf++ = hex[val >> 4];
196 *buf++ = hex[val & 0xf];
197 }
a6080a0a 198
bf592c50
DB
199 return base;
200}
201
202char *sha1_pack_index_name(const unsigned char *sha1)
203{
204 static const char hex[] = "0123456789abcdef";
205 static char *name, *base, *buf;
206 int i;
207
208 if (!base) {
209 const char *sha1_file_directory = get_object_directory();
210 int len = strlen(sha1_file_directory);
211 base = xmalloc(len + 60);
212 sprintf(base, "%s/pack/pack-1234567890123456789012345678901234567890.idx", sha1_file_directory);
213 name = base + len + 11;
214 }
215
216 buf = name;
217
218 for (i = 0; i < 20; i++) {
219 unsigned int val = *sha1++;
220 *buf++ = hex[val >> 4];
221 *buf++ = hex[val & 0xf];
222 }
a6080a0a 223
bf592c50
DB
224 return base;
225}
226
d5a63b99
JH
227struct alternate_object_database *alt_odb_list;
228static struct alternate_object_database **alt_odb_tail;
ace1534d 229
c2f493a4
MW
230static void read_info_alternates(const char * alternates, int depth);
231
ddd5d056
JH
232/*
233 * Prepare alternate object database registry.
d5a63b99
JH
234 *
235 * The variable alt_odb_list points at the list of struct
236 * alternate_object_database. The elements on this list come from
237 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
238 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
239 * whose contents is similar to that environment variable but can be
240 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
241 * contains "/the/directory/corresponding/to/.git/objects/...", while
242 * its name points just after the slash at the end of ".git/objects/"
243 * in the example above, and has enough space to hold 40-byte hex
244 * SHA1, an extra slash for the first level indirection, and the
245 * terminating NUL.
ddd5d056 246 */
c2f493a4 247static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 248{
c2f493a4 249 struct stat st;
1494e038 250 const char *objdir = get_object_directory();
c2f493a4
MW
251 struct alternate_object_database *ent;
252 struct alternate_object_database *alt;
253 /* 43 = 40-byte + 2 '/' + terminating NUL */
254 int pfxlen = len;
255 int entlen = pfxlen + 43;
ccfd3e99 256 int base_len = -1;
d5a63b99 257
85dadc38 258 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
259 /* Relative alt-odb */
260 if (base_len < 0)
261 base_len = strlen(relative_base) + 1;
262 entlen += base_len;
263 pfxlen += base_len;
264 }
265 ent = xmalloc(sizeof(*ent) + entlen);
266
85dadc38 267 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
268 memcpy(ent->base, relative_base, base_len - 1);
269 ent->base[base_len - 1] = '/';
270 memcpy(ent->base + base_len, entry, len);
271 }
272 else
273 memcpy(ent->base, entry, pfxlen);
274
275 ent->name = ent->base + pfxlen + 1;
276 ent->base[pfxlen + 3] = '/';
277 ent->base[pfxlen] = ent->base[entlen-1] = 0;
278
279 /* Detect cases where alternate disappeared */
280 if (stat(ent->base, &st) || !S_ISDIR(st.st_mode)) {
281 error("object directory %s does not exist; "
282 "check .git/objects/info/alternates.",
283 ent->base);
284 free(ent);
285 return -1;
286 }
287
288 /* Prevent the common mistake of listing the same
289 * thing twice, or object directory itself.
290 */
291 for (alt = alt_odb_list; alt; alt = alt->next) {
292 if (!memcmp(ent->base, alt->base, pfxlen)) {
293 free(ent);
294 return -1;
295 }
296 }
297 if (!memcmp(ent->base, objdir, pfxlen)) {
298 free(ent);
299 return -1;
300 }
301
302 /* add the alternate entry */
303 *alt_odb_tail = ent;
304 alt_odb_tail = &(ent->next);
305 ent->next = NULL;
306
307 /* recursively add alternates */
308 read_info_alternates(ent->base, depth + 1);
309
310 ent->base[pfxlen] = '/';
311
312 return 0;
313}
314
315static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
316 const char *relative_base, int depth)
317{
318 const char *cp, *last;
319
320 if (depth > 5) {
321 error("%s: ignoring alternate object stores, nesting too deep.",
322 relative_base);
323 return;
324 }
325
d5a63b99 326 last = alt;
9577e7e3
JH
327 while (last < ep) {
328 cp = last;
329 if (cp < ep && *cp == '#') {
330 while (cp < ep && *cp != sep)
331 cp++;
332 last = cp + 1;
333 continue;
334 }
c2f493a4
MW
335 while (cp < ep && *cp != sep)
336 cp++;
d5a63b99 337 if (last != cp) {
85dadc38 338 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
339 error("%s: ignoring relative alternate object store %s",
340 relative_base, last);
341 } else {
342 link_alt_odb_entry(last, cp - last,
343 relative_base, depth);
1494e038 344 }
d5a63b99 345 }
9577e7e3 346 while (cp < ep && *cp == sep)
d5a63b99
JH
347 cp++;
348 last = cp;
9577e7e3 349 }
d5a63b99
JH
350}
351
c2f493a4 352static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 353{
9577e7e3 354 char *map;
dc49cd76 355 size_t mapsz;
d5a63b99 356 struct stat st;
9cb18f56
JM
357 const char alt_file_name[] = "info/alternates";
358 /* Given that relative_base is no longer than PATH_MAX,
359 ensure that "path" has enough space to append "/", the
360 file name, "info/alternates", and a trailing NUL. */
361 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 362 int fd;
d5a63b99 363
9cb18f56 364 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
365 fd = open(path, O_RDONLY);
366 if (fd < 0)
367 return;
368 if (fstat(fd, &st) || (st.st_size == 0)) {
369 close(fd);
9a217f2a 370 return;
ace1534d 371 }
dc49cd76
SP
372 mapsz = xsize_t(st.st_size);
373 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 374 close(fd);
d5a63b99 375
dc49cd76 376 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 377
dc49cd76 378 munmap(map, mapsz);
ace1534d
JH
379}
380
c2f493a4
MW
381void prepare_alt_odb(void)
382{
554fe20d 383 const char *alt;
c2f493a4 384
7dc24aa5
SP
385 if (alt_odb_tail)
386 return;
387
c2f493a4
MW
388 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
389 if (!alt) alt = "";
390
c2f493a4
MW
391 alt_odb_tail = &alt_odb_list;
392 link_alt_odb_entries(alt, alt + strlen(alt), ':', NULL, 0);
393
394 read_info_alternates(get_object_directory(), 0);
395}
396
ace1534d
JH
397static char *find_sha1_file(const unsigned char *sha1, struct stat *st)
398{
ace1534d 399 char *name = sha1_file_name(sha1);
d5a63b99 400 struct alternate_object_database *alt;
ace1534d
JH
401
402 if (!stat(name, st))
403 return name;
9a217f2a 404 prepare_alt_odb();
d5a63b99
JH
405 for (alt = alt_odb_list; alt; alt = alt->next) {
406 name = alt->name;
ace1534d 407 fill_sha1_path(name, sha1);
d5a63b99
JH
408 if (!stat(alt->base, st))
409 return alt->base;
ace1534d
JH
410 }
411 return NULL;
412}
413
60bb8b14 414static unsigned int pack_used_ctr;
a53128b6
SP
415static unsigned int pack_mmap_calls;
416static unsigned int peak_pack_open_windows;
417static unsigned int pack_open_windows;
418static size_t peak_pack_mapped;
60bb8b14 419static size_t pack_mapped;
9a217f2a 420struct packed_git *packed_git;
1f688557 421
b79d18c9 422void pack_report(void)
a53128b6
SP
423{
424 fprintf(stderr,
e05db0fd
PR
425 "pack_report: getpagesize() = %10" SZ_FMT "\n"
426 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
427 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
428 sz_fmt(getpagesize()),
429 sz_fmt(packed_git_window_size),
430 sz_fmt(packed_git_limit));
a53128b6
SP
431 fprintf(stderr,
432 "pack_report: pack_used_ctr = %10u\n"
433 "pack_report: pack_mmap_calls = %10u\n"
434 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
435 "pack_report: pack_mapped = "
436 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
437 pack_used_ctr,
438 pack_mmap_calls,
439 pack_open_windows, peak_pack_open_windows,
9e42d6a1 440 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
441}
442
42873078 443static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
444{
445 void *idx_map;
42873078 446 struct pack_idx_header *hdr;
dc49cd76 447 size_t idx_size;
74e34e1f 448 uint32_t version, nr, i, *index;
e93ec6f9 449 int fd = open(path, O_RDONLY);
1f688557 450 struct stat st;
42873078 451
1f688557
JH
452 if (fd < 0)
453 return -1;
454 if (fstat(fd, &st)) {
455 close(fd);
456 return -1;
457 }
dc49cd76 458 idx_size = xsize_t(st.st_size);
2d88451b
SP
459 if (idx_size < 4 * 256 + 20 + 20) {
460 close(fd);
461 return error("index file %s is too small", path);
462 }
c4712e45 463 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 464 close(fd);
1f688557 465
42873078
NP
466 hdr = idx_map;
467 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
468 version = ntohl(hdr->idx_version);
469 if (version < 2 || version > 2) {
470 munmap(idx_map, idx_size);
471 return error("index file %s is version %d"
472 " and is not supported by this binary"
473 " (try upgrading GIT to a newer version)",
474 path, version);
475 }
476 } else
477 version = 1;
df1b059d 478
1f688557 479 nr = 0;
42873078 480 index = idx_map;
74e34e1f
NP
481 if (version > 1)
482 index += 2; /* skip index header */
1f688557 483 for (i = 0; i < 256; i++) {
326bf396 484 uint32_t n = ntohl(index[i]);
2d88451b
SP
485 if (n < nr) {
486 munmap(idx_map, idx_size);
df1b059d 487 return error("non-monotonic index %s", path);
2d88451b 488 }
1f688557
JH
489 nr = n;
490 }
491
74e34e1f
NP
492 if (version == 1) {
493 /*
494 * Total size:
495 * - 256 index entries 4 bytes each
496 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
497 * - 20-byte SHA1 of the packfile
498 * - 20-byte SHA1 file checksum
499 */
500 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
501 munmap(idx_map, idx_size);
eef427a0 502 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
503 }
504 } else if (version == 2) {
505 /*
506 * Minimum size:
507 * - 8 bytes of header
508 * - 256 index entries 4 bytes each
509 * - 20-byte sha1 entry * nr
510 * - 4-byte crc entry * nr
511 * - 4-byte offset entry * nr
512 * - 20-byte SHA1 of the packfile
513 * - 20-byte SHA1 file checksum
514 * And after the 4-byte offset table might be a
515 * variable sized table containing 8-byte entries
516 * for offsets larger than 2^31.
517 */
518 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
519 unsigned long max_size = min_size;
520 if (nr)
521 max_size += (nr - 1)*8;
522 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 523 munmap(idx_map, idx_size);
eef427a0 524 return error("wrong index v2 file size in %s", path);
74e34e1f 525 }
7109c889
JH
526 if (idx_size != min_size &&
527 /*
528 * make sure we can deal with large pack offsets.
529 * 31-bit signed offset won't be enough, neither
530 * 32-bit unsigned one will be.
531 */
532 (sizeof(off_t) <= 4)) {
533 munmap(idx_map, idx_size);
534 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 535 }
2d88451b 536 }
1f688557 537
74e34e1f 538 p->index_version = version;
42873078
NP
539 p->index_data = idx_map;
540 p->index_size = idx_size;
57059091 541 p->num_objects = nr;
1f688557
JH
542 return 0;
543}
544
bc8e478a 545int open_pack_index(struct packed_git *p)
d079837e
SP
546{
547 char *idx_name;
548 int ret;
549
550 if (p->index_data)
551 return 0;
552
553 idx_name = xstrdup(p->pack_name);
554 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
555 ret = check_packed_git_idx(idx_name, p);
556 free(idx_name);
557 return ret;
558}
559
11daf39b
SP
560static void scan_windows(struct packed_git *p,
561 struct packed_git **lru_p,
562 struct pack_window **lru_w,
563 struct pack_window **lru_l)
1f688557 564{
11daf39b
SP
565 struct pack_window *w, *w_l;
566
567 for (w_l = NULL, w = p->windows; w; w = w->next) {
568 if (!w->inuse_cnt) {
569 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
570 *lru_p = p;
571 *lru_w = w;
572 *lru_l = w_l;
54044bf8 573 }
54044bf8 574 }
11daf39b 575 w_l = w;
f9253394 576 }
11daf39b
SP
577}
578
d1efefa4 579static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
580{
581 struct packed_git *p, *lru_p = NULL;
582 struct pack_window *lru_w = NULL, *lru_l = NULL;
583
584 if (current)
585 scan_windows(current, &lru_p, &lru_w, &lru_l);
586 for (p = packed_git; p; p = p->next)
587 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
588 if (lru_p) {
589 munmap(lru_w->base, lru_w->len);
590 pack_mapped -= lru_w->len;
591 if (lru_l)
592 lru_l->next = lru_w->next;
593 else {
594 lru_p->windows = lru_w->next;
d1efefa4 595 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
596 close(lru_p->pack_fd);
597 lru_p->pack_fd = -1;
598 }
599 }
600 free(lru_w);
a53128b6 601 pack_open_windows--;
54044bf8
SP
602 return 1;
603 }
604 return 0;
f9253394
JH
605}
606
d1efefa4 607void release_pack_memory(size_t need, int fd)
97bfeb34
SP
608{
609 size_t cur = pack_mapped;
d1efefa4 610 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
611 ; /* nothing */
612}
613
c9ced051
SP
614void close_pack_windows(struct packed_git *p)
615{
616 while (p->windows) {
617 struct pack_window *w = p->windows;
618
619 if (w->inuse_cnt)
620 die("pack '%s' still has open windows to it",
621 p->pack_name);
622 munmap(w->base, w->len);
623 pack_mapped -= w->len;
624 pack_open_windows--;
625 p->windows = w->next;
626 free(w);
627 }
628}
629
03e79c88 630void unuse_pack(struct pack_window **w_cursor)
f9253394 631{
03e79c88
SP
632 struct pack_window *w = *w_cursor;
633 if (w) {
634 w->inuse_cnt--;
635 *w_cursor = NULL;
636 }
1f688557
JH
637}
638
3cf8b462
SP
639/*
640 * Do not call this directly as this leaks p->pack_fd on error return;
641 * call open_packed_git() instead.
642 */
643static int open_packed_git_1(struct packed_git *p)
1f688557 644{
9bc879c1
SP
645 struct stat st;
646 struct pack_header hdr;
647 unsigned char sha1[20];
648 unsigned char *idx_sha1;
2c039da8 649 long fd_flag;
9bc879c1 650
d079837e
SP
651 if (!p->index_data && open_pack_index(p))
652 return error("packfile %s index unavailable", p->pack_name);
653
9bc879c1
SP
654 p->pack_fd = open(p->pack_name, O_RDONLY);
655 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 656 return -1;
9bc879c1
SP
657
658 /* If we created the struct before we had the pack we lack size. */
bf592c50 659 if (!p->pack_size) {
bf592c50 660 if (!S_ISREG(st.st_mode))
072db278 661 return error("packfile %s not a regular file", p->pack_name);
bf592c50 662 p->pack_size = st.st_size;
9bc879c1 663 } else if (p->pack_size != st.st_size)
072db278 664 return error("packfile %s size changed", p->pack_name);
9bc879c1 665
2c039da8
JH
666 /* We leave these file descriptors open with sliding mmap;
667 * there is no point keeping them open across exec(), though.
668 */
669 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
670 if (fd_flag < 0)
072db278 671 return error("cannot determine file descriptor flags");
2c039da8
JH
672 fd_flag |= FD_CLOEXEC;
673 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 674 return error("cannot set FD_CLOEXEC");
2c039da8 675
9bc879c1 676 /* Verify we recognize this pack file format. */
e6e2bd62 677 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 678 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 679 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 680 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 681 if (!pack_version_ok(hdr.hdr_version))
072db278 682 return error("packfile %s is version %u and not supported"
9bc879c1
SP
683 " (try upgrading GIT to a newer version)",
684 p->pack_name, ntohl(hdr.hdr_version));
685
686 /* Verify the pack matches its index. */
57059091 687 if (p->num_objects != ntohl(hdr.hdr_entries))
072db278 688 return error("packfile %s claims to have %u objects"
57059091
NP
689 " while index indicates %u objects",
690 p->pack_name, ntohl(hdr.hdr_entries),
691 p->num_objects);
9bc879c1 692 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 693 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 694 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 695 return error("packfile %s signature is unavailable", p->pack_name);
42873078 696 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 697 if (hashcmp(sha1, idx_sha1))
072db278
SP
698 return error("packfile %s does not match index", p->pack_name);
699 return 0;
9bc879c1
SP
700}
701
3cf8b462
SP
702static int open_packed_git(struct packed_git *p)
703{
704 if (!open_packed_git_1(p))
705 return 0;
706 if (p->pack_fd != -1) {
707 close(p->pack_fd);
708 p->pack_fd = -1;
709 }
710 return -1;
711}
712
c4001d92 713static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
714{
715 /* We must promise at least 20 bytes (one hash) after the
716 * offset is available from this window, otherwise the offset
717 * is not actually in this window and a different window (which
718 * has that one hash excess) must be used. This is to support
719 * the object header and delta base parsing routines below.
720 */
721 off_t win_off = win->offset;
722 return win_off <= offset
723 && (offset + 20) <= (win_off + win->len);
724}
725
03e79c88
SP
726unsigned char* use_pack(struct packed_git *p,
727 struct pack_window **w_cursor,
c4001d92 728 off_t offset,
03e79c88 729 unsigned int *left)
9bc879c1 730{
60bb8b14 731 struct pack_window *win = *w_cursor;
03e79c88 732
072db278
SP
733 if (p->pack_fd == -1 && open_packed_git(p))
734 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
735
736 /* Since packfiles end in a hash of their content and its
737 * pointless to ask for an offset into the middle of that
738 * hash, and the in_window function above wouldn't match
739 * don't allow an offset too close to the end of the file.
740 */
741 if (offset > (p->pack_size - 20))
742 die("offset beyond end of packfile (truncated pack?)");
743
744 if (!win || !in_window(win, offset)) {
745 if (win)
746 win->inuse_cnt--;
747 for (win = p->windows; win; win = win->next) {
748 if (in_window(win, offset))
749 break;
750 }
751 if (!win) {
78a28df9 752 size_t window_align = packed_git_window_size / 2;
dc49cd76 753 off_t len;
60bb8b14 754 win = xcalloc(1, sizeof(*win));
78a28df9 755 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
756 len = p->pack_size - win->offset;
757 if (len > packed_git_window_size)
758 len = packed_git_window_size;
759 win->len = (size_t)len;
60bb8b14 760 pack_mapped += win->len;
11daf39b 761 while (packed_git_limit < pack_mapped
d1efefa4 762 && unuse_one_window(p, p->pack_fd))
60bb8b14 763 ; /* nothing */
c4712e45 764 win->base = xmmap(NULL, win->len,
60bb8b14
SP
765 PROT_READ, MAP_PRIVATE,
766 p->pack_fd, win->offset);
767 if (win->base == MAP_FAILED)
73b4e4be
SP
768 die("packfile %s cannot be mapped: %s",
769 p->pack_name,
770 strerror(errno));
a53128b6
SP
771 pack_mmap_calls++;
772 pack_open_windows++;
773 if (pack_mapped > peak_pack_mapped)
774 peak_pack_mapped = pack_mapped;
775 if (pack_open_windows > peak_pack_open_windows)
776 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
777 win->next = p->windows;
778 p->windows = win;
779 }
1f688557 780 }
03e79c88
SP
781 if (win != *w_cursor) {
782 win->last_used = pack_used_ctr++;
783 win->inuse_cnt++;
784 *w_cursor = win;
785 }
60bb8b14 786 offset -= win->offset;
03e79c88 787 if (left)
dc49cd76 788 *left = win->len - xsize_t(offset);
03e79c88 789 return win->base + offset;
1f688557
JH
790}
791
42873078 792struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
793{
794 struct stat st;
42873078 795 struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
1f688557 796
42873078
NP
797 /*
798 * Make sure a corresponding .pack file exists and that
799 * the index looks sane.
800 */
801 path_len -= strlen(".idx");
802 if (path_len < 1)
1f688557 803 return NULL;
42873078
NP
804 memcpy(p->pack_name, path, path_len);
805 strcpy(p->pack_name + path_len, ".pack");
d079837e 806 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 807 free(p);
1f688557
JH
808 return NULL;
809 }
42873078 810
1f688557
JH
811 /* ok, it looks sane as far as we can check without
812 * actually mapping the pack file.
813 */
d079837e
SP
814 p->index_version = 0;
815 p->index_data = NULL;
816 p->index_size = 0;
817 p->num_objects = 0;
1f688557 818 p->pack_size = st.st_size;
1f688557 819 p->next = NULL;
c41ee586 820 p->windows = NULL;
9bc879c1 821 p->pack_fd = -1;
9d835df2 822 p->pack_local = local;
b867092f 823 p->mtime = st.st_mtime;
42873078
NP
824 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
825 hashclr(p->sha1);
1f688557
JH
826 return p;
827}
828
bf592c50 829struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
830{
831 char *path = sha1_pack_index_name(sha1);
832 return parse_pack_index_file(sha1, path);
833}
834
42873078
NP
835struct packed_git *parse_pack_index_file(const unsigned char *sha1,
836 const char *idx_path)
bf592c50 837{
42873078
NP
838 const char *path = sha1_pack_name(sha1);
839 struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
bf592c50 840
42873078
NP
841 if (check_packed_git_idx(idx_path, p)) {
842 free(p);
bf592c50 843 return NULL;
42873078 844 }
bf592c50 845
bf592c50 846 strcpy(p->pack_name, path);
bf592c50 847 p->pack_size = 0;
bf592c50 848 p->next = NULL;
c41ee586 849 p->windows = NULL;
9bc879c1 850 p->pack_fd = -1;
e702496e 851 hashcpy(p->sha1, sha1);
bf592c50
DB
852 return p;
853}
854
855void install_packed_git(struct packed_git *pack)
856{
857 pack->next = packed_git;
858 packed_git = pack;
859}
860
9d835df2 861static void prepare_packed_git_one(char *objdir, int local)
1f688557 862{
9cb18f56
JM
863 /* Ensure that this buffer is large enough so that we can
864 append "/pack/" without clobbering the stack even if
865 strlen(objdir) were PATH_MAX. */
866 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
867 int len;
868 DIR *dir;
869 struct dirent *de;
870
871 sprintf(path, "%s/pack", objdir);
872 len = strlen(path);
873 dir = opendir(path);
b5b16990 874 if (!dir) {
26125f6b 875 if (errno != ENOENT)
bd2afde8 876 error("unable to open object pack directory: %s: %s",
26125f6b 877 path, strerror(errno));
1f688557 878 return;
b5b16990 879 }
1f688557
JH
880 path[len++] = '/';
881 while ((de = readdir(dir)) != NULL) {
882 int namelen = strlen(de->d_name);
883 struct packed_git *p;
884
5bb1cda5 885 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
886 continue;
887
9cb18f56
JM
888 if (len + namelen + 1 > sizeof(path))
889 continue;
890
54a15a8d 891 /* Don't reopen a pack we already have. */
1f688557 892 strcpy(path + len, de->d_name);
86f7780c
JK
893 for (p = packed_git; p; p = p->next) {
894 if (!memcmp(path, p->pack_name, len + namelen - 4))
895 break;
896 }
897 if (p)
898 continue;
54a15a8d
SP
899 /* See if it really is a valid .idx file with corresponding
900 * .pack file that we can map.
901 */
9d835df2 902 p = add_packed_git(path, len + namelen, local);
1f688557
JH
903 if (!p)
904 continue;
625e9421 905 install_packed_git(p);
1f688557 906 }
5b35bcd5 907 closedir(dir);
1f688557
JH
908}
909
b867092f
JH
910static int sort_pack(const void *a_, const void *b_)
911{
912 struct packed_git *a = *((struct packed_git **)a_);
913 struct packed_git *b = *((struct packed_git **)b_);
914 int st;
915
916 /*
917 * Local packs tend to contain objects specific to our
918 * variant of the project than remote ones. In addition,
919 * remote ones could be on a network mounted filesystem.
920 * Favor local ones for these reasons.
921 */
922 st = a->pack_local - b->pack_local;
923 if (st)
924 return -st;
925
926 /*
927 * Younger packs tend to contain more recent objects,
928 * and more recent objects tend to get accessed more
929 * often.
930 */
931 if (a->mtime < b->mtime)
932 return 1;
933 else if (a->mtime == b->mtime)
934 return 0;
935 return -1;
936}
937
938static void rearrange_packed_git(void)
939{
940 struct packed_git **ary, *p;
941 int i, n;
942
943 for (n = 0, p = packed_git; p; p = p->next)
944 n++;
945 if (n < 2)
946 return;
947
948 /* prepare an array of packed_git for easier sorting */
949 ary = xcalloc(n, sizeof(struct packed_git *));
950 for (n = 0, p = packed_git; p; p = p->next)
951 ary[n++] = p;
952
953 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
954
955 /* link them back again */
956 for (i = 0; i < n - 1; i++)
957 ary[i]->next = ary[i + 1];
958 ary[n - 1]->next = NULL;
959 packed_git = ary[0];
960
961 free(ary);
962}
963
637cdd9d 964static int prepare_packed_git_run_once = 0;
9a217f2a 965void prepare_packed_git(void)
1f688557 966{
d5a63b99 967 struct alternate_object_database *alt;
1f688557 968
637cdd9d 969 if (prepare_packed_git_run_once)
1f688557 970 return;
9d835df2 971 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 972 prepare_alt_odb();
d5a63b99 973 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 974 alt->name[-1] = 0;
9d835df2 975 prepare_packed_git_one(alt->base, 0);
1494e038 976 alt->name[-1] = '/';
1f688557 977 }
b867092f 978 rearrange_packed_git();
637cdd9d
JK
979 prepare_packed_git_run_once = 1;
980}
981
fc04c412 982void reprepare_packed_git(void)
637cdd9d
JK
983{
984 prepare_packed_git_run_once = 0;
985 prepare_packed_git();
1f688557
JH
986}
987
5d6ccf5c 988int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
989{
990 unsigned char real_sha1[20];
7cfb5f36 991 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 992 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
993}
994
4175e9e3 995static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 996{
0fcfd160
LT
997 struct stat st;
998 void *map;
144bde78 999 int fd;
ace1534d
JH
1000 char *filename = find_sha1_file(sha1, &st);
1001
1002 if (!filename) {
ace1534d
JH
1003 return NULL;
1004 }
0fcfd160 1005
144bde78 1006 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 1007 if (fd < 0) {
144bde78
LT
1008 /* See if it works without O_NOATIME */
1009 switch (sha1_file_open_flag) {
1010 default:
1011 fd = open(filename, O_RDONLY);
1012 if (fd >= 0)
1013 break;
1014 /* Fallthrough */
1015 case 0:
144bde78
LT
1016 return NULL;
1017 }
1018
1f688557
JH
1019 /* If it failed once, it will probably fail again.
1020 * Stop using O_NOATIME
1021 */
144bde78 1022 sha1_file_open_flag = 0;
0fcfd160 1023 }
dc49cd76
SP
1024 *size = xsize_t(st.st_size);
1025 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
0fcfd160 1026 close(fd);
0fcfd160
LT
1027 return map;
1028}
1029
726f852b 1030static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1031{
1032 unsigned int word;
1033
1034 /*
1035 * Is it a zlib-compressed buffer? If so, the first byte
1036 * must be 0x78 (15-bit window size, deflated), and the
1037 * first 16-bit word is evenly divisible by 31
1038 */
1039 word = (map[0] << 8) + map[1];
1040 if (map[0] == 0x78 && !(word % 31))
1041 return 1;
1042 else
1043 return 0;
1044}
1045
72518e9c 1046unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1047{
ad1ed5ee 1048 unsigned shift;
93821bd9 1049 unsigned char c;
93821bd9 1050 unsigned long size;
ad1ed5ee
JH
1051 unsigned long used = 0;
1052
1053 c = buf[used++];
1054 *type = (c >> 4) & 7;
1055 size = c & 15;
1056 shift = 4;
1057 while (c & 0x80) {
1058 if (len <= used)
1059 return 0;
1060 if (sizeof(long) * 8 <= shift)
1061 return 0;
1062 c = buf[used++];
1063 size += (c & 0x7f) << shift;
1064 shift += 7;
1065 }
1066 *sizep = size;
1067 return used;
1068}
1069
1070static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1071{
1072 unsigned long size, used;
1073 static const char valid_loose_object_type[8] = {
1074 0, /* OBJ_EXT */
1075 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1076 0, /* "delta" and others are invalid in a loose object */
93821bd9 1077 };
ad1ed5ee 1078 enum object_type type;
93821bd9 1079
c4483576
LT
1080 /* Get the data stream */
1081 memset(stream, 0, sizeof(*stream));
1082 stream->next_in = map;
1083 stream->avail_in = mapsize;
1084 stream->next_out = buffer;
93821bd9
LT
1085 stream->avail_out = bufsiz;
1086
bb6b8e4f 1087 if (legacy_loose_object(map)) {
93821bd9
LT
1088 inflateInit(stream);
1089 return inflate(stream, 0);
1090 }
1091
726f852b
NP
1092
1093 /*
1094 * There used to be a second loose object header format which
1095 * was meant to mimic the in-pack format, allowing for direct
1096 * copy of the object data. This format turned up not to be
1097 * really worth it and we don't write it any longer. But we
1098 * can still read it.
1099 */
ad1ed5ee
JH
1100 used = unpack_object_header_gently(map, mapsize, &type, &size);
1101 if (!used || !valid_loose_object_type[type])
93821bd9 1102 return -1;
ad1ed5ee
JH
1103 map += used;
1104 mapsize -= used;
93821bd9
LT
1105
1106 /* Set up the stream for the rest.. */
1107 stream->next_in = map;
1108 stream->avail_in = mapsize;
c4483576 1109 inflateInit(stream);
93821bd9
LT
1110
1111 /* And generate the fake traditional header */
ad1ed5ee 1112 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1113 typename(type), size);
93821bd9 1114 return 0;
c4483576
LT
1115}
1116
7efbff75 1117static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1118{
1119 int bytes = strlen(buffer) + 1;
d565b341 1120 unsigned char *buf = xmalloc(1+size);
93821bd9 1121 unsigned long n;
7efbff75 1122 int status = Z_OK;
5180cacc 1123
93821bd9
LT
1124 n = stream->total_out - bytes;
1125 if (n > size)
1126 n = size;
1127 memcpy(buf, (char *) buffer + bytes, n);
1128 bytes = n;
456cdf6e
LT
1129 if (bytes <= size) {
1130 /*
1131 * The above condition must be (bytes <= size), not
1132 * (bytes < size). In other words, even though we
1133 * expect no more output and set avail_out to zer0,
1134 * the input zlib stream may have bytes that express
1135 * "this concludes the stream", and we *do* want to
1136 * eat that input.
1137 *
1138 * Otherwise we would not be able to test that we
1139 * consumed all the input to reach the expected size;
1140 * we also want to check that zlib tells us that all
1141 * went well with status == Z_STREAM_END at the end.
1142 */
5180cacc
LT
1143 stream->next_out = buf + bytes;
1144 stream->avail_out = size - bytes;
7efbff75
JH
1145 while (status == Z_OK)
1146 status = inflate(stream, Z_FINISH);
5180cacc
LT
1147 }
1148 buf[size] = 0;
456cdf6e 1149 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1150 inflateEnd(stream);
1151 return buf;
1152 }
1153
1154 if (status < 0)
1155 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1156 else if (stream->avail_in)
1157 error("garbage at end of loose object '%s'",
1158 sha1_to_hex(sha1));
1159 free(buf);
1160 return NULL;
5180cacc
LT
1161}
1162
1163/*
1164 * We used to just use "sscanf()", but that's actually way
1165 * too permissive for what we want to check. So do an anal
1166 * object header parse by hand.
1167 */
21666f1a 1168static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1169{
21666f1a 1170 char type[10];
5180cacc
LT
1171 int i;
1172 unsigned long size;
1173
1174 /*
a6080a0a 1175 * The type can be at most ten bytes (including the
5180cacc 1176 * terminating '\0' that we add), and is followed by
21666f1a 1177 * a space.
5180cacc 1178 */
21666f1a 1179 i = 0;
5180cacc
LT
1180 for (;;) {
1181 char c = *hdr++;
1182 if (c == ' ')
1183 break;
21666f1a
NP
1184 type[i++] = c;
1185 if (i >= sizeof(type))
5180cacc 1186 return -1;
5180cacc 1187 }
21666f1a 1188 type[i] = 0;
5180cacc
LT
1189
1190 /*
1191 * The length must follow immediately, and be in canonical
1192 * decimal format (ie "010" is not valid).
1193 */
1194 size = *hdr++ - '0';
1195 if (size > 9)
1196 return -1;
1197 if (size) {
1198 for (;;) {
1199 unsigned long c = *hdr - '0';
1200 if (c > 9)
1201 break;
1202 hdr++;
1203 size = size * 10 + c;
1204 }
1205 }
1206 *sizep = size;
1207
1208 /*
1209 * The length must be followed by a zero byte
1210 */
21666f1a 1211 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1212}
1213
7efbff75 1214static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1215{
5180cacc 1216 int ret;
0fcfd160 1217 z_stream stream;
5180cacc 1218 char hdr[8192];
0fcfd160 1219
5180cacc 1220 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1221 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1222 return NULL;
1223
7efbff75 1224 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1225}
1226
54dab52a
NP
1227unsigned long get_size_from_delta(struct packed_git *p,
1228 struct pack_window **w_curs,
1229 off_t curpos)
1230{
1231 const unsigned char *data;
1232 unsigned char delta_head[20], *in;
1233 z_stream stream;
1234 int st;
1235
1236 memset(&stream, 0, sizeof(stream));
1237 stream.next_out = delta_head;
1238 stream.avail_out = sizeof(delta_head);
1239
1240 inflateInit(&stream);
1241 do {
1242 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1243 stream.next_in = in;
1244 st = inflate(&stream, Z_FINISH);
1245 curpos += stream.next_in - in;
1246 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1247 stream.total_out < sizeof(delta_head));
1248 inflateEnd(&stream);
1249 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1250 die("delta data unpack-initial failed");
1251
1252 /* Examine the initial part of the delta to figure out
1253 * the result size.
1254 */
1255 data = delta_head;
1256
1257 /* ignore base size */
1258 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1259
1260 /* Read the result size */
1261 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1262}
1263
c4001d92 1264static off_t get_delta_base(struct packed_git *p,
03e79c88 1265 struct pack_window **w_curs,
c4001d92 1266 off_t *curpos,
21666f1a 1267 enum object_type type,
c4001d92 1268 off_t delta_obj_offset)
eb32d236 1269{
2b87c45b 1270 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1271 off_t base_offset;
eb32d236 1272
8d8a4ea5
SP
1273 /* use_pack() assured us we have [base_info, base_info + 20)
1274 * as a range that we can look at without walking off the
1275 * end of the mapped window. Its actually the hash size
1276 * that is assured. An OFS_DELTA longer than the hash size
1277 * is stupid, as then a REF_DELTA would be smaller to store.
1278 */
21666f1a 1279 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1280 unsigned used = 0;
1281 unsigned char c = base_info[used++];
1282 base_offset = c & 127;
1283 while (c & 128) {
1284 base_offset += 1;
8723f216 1285 if (!base_offset || MSB(base_offset, 7))
eb32d236
NP
1286 die("offset value overflow for delta base object");
1287 c = base_info[used++];
1288 base_offset = (base_offset << 7) + (c & 127);
1289 }
1290 base_offset = delta_obj_offset - base_offset;
1291 if (base_offset >= delta_obj_offset)
1292 die("delta base offset out of bound");
2b87c45b 1293 *curpos += used;
21666f1a 1294 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1295 /* The base entry _must_ be in the same pack */
1296 base_offset = find_pack_entry_one(base_info, p);
1297 if (!base_offset)
1298 die("failed to find delta-pack base object %s",
1299 sha1_to_hex(base_info));
2b87c45b 1300 *curpos += 20;
eb32d236
NP
1301 } else
1302 die("I am totally screwed");
2b87c45b 1303 return base_offset;
eb32d236
NP
1304}
1305
f3bf9224 1306/* forward declaration for a mutually recursive function */
c4001d92 1307static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1308 unsigned long *sizep);
f3bf9224 1309
43057304 1310static int packed_delta_info(struct packed_git *p,
03e79c88 1311 struct pack_window **w_curs,
c4001d92 1312 off_t curpos,
21666f1a 1313 enum object_type type,
c4001d92 1314 off_t obj_offset,
43057304 1315 unsigned long *sizep)
5db47c2b 1316{
c4001d92 1317 off_t base_offset;
f3bf9224 1318
21666f1a
NP
1319 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1320 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1321
c62266f3
JH
1322 /* We choose to only get the type of the base object and
1323 * ignore potentially corrupt pack file that expects the delta
1324 * based on a base with a wrong size. This saves tons of
1325 * inflate() calls.
1326 */
54dab52a
NP
1327 if (sizep)
1328 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1329
1330 return type;
5db47c2b
JH
1331}
1332
2b87c45b
NP
1333static int unpack_object_header(struct packed_git *p,
1334 struct pack_window **w_curs,
c4001d92 1335 off_t *curpos,
2b87c45b 1336 unsigned long *sizep)
a733cb60 1337{
03e79c88
SP
1338 unsigned char *base;
1339 unsigned int left;
ad1ed5ee 1340 unsigned long used;
2b87c45b 1341 enum object_type type;
a733cb60 1342
8d8a4ea5
SP
1343 /* use_pack() assures us we have [base, base + 20) available
1344 * as a range that we can look at at. (Its actually the hash
3dff5379 1345 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1346 * the maximum deflated object size is 2^137, which is just
1347 * insane, so we know won't exceed what we have been given.
1348 */
2b87c45b
NP
1349 base = use_pack(p, w_curs, *curpos, &left);
1350 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1351 if (!used)
1352 die("object offset outside of pack file");
2b87c45b 1353 *curpos += used;
ad1ed5ee 1354
2b87c45b 1355 return type;
a733cb60
LT
1356}
1357
21666f1a 1358const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1359 off_t obj_offset,
21666f1a
NP
1360 unsigned long *size,
1361 unsigned long *store_size,
1362 unsigned int *delta_chain_length,
1363 unsigned char *base_sha1)
ad8c80a5 1364{
03e79c88 1365 struct pack_window *w_curs = NULL;
c4001d92
SP
1366 off_t curpos;
1367 unsigned long dummy;
43057304 1368 unsigned char *next_sha1;
21666f1a 1369 enum object_type type;
ad8c80a5 1370
43057304 1371 *delta_chain_length = 0;
2b87c45b 1372 curpos = obj_offset;
21666f1a 1373 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304
NP
1374
1375 for (;;) {
21666f1a 1376 switch (type) {
43057304 1377 default:
08a19d87 1378 die("pack %s contains unknown object type %d",
21666f1a 1379 p->pack_name, type);
43057304
NP
1380 case OBJ_COMMIT:
1381 case OBJ_TREE:
1382 case OBJ_BLOB:
1383 case OBJ_TAG:
43057304 1384 *store_size = 0; /* notyet */
03e79c88 1385 unuse_pack(&w_curs);
21666f1a 1386 return typename(type);
eb32d236 1387 case OBJ_OFS_DELTA:
21666f1a 1388 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
eb32d236 1389 if (*delta_chain_length == 0) {
2b87c45b 1390 /* TODO: find base_sha1 as pointed by curpos */
30fee062 1391 hashclr(base_sha1);
eb32d236
NP
1392 }
1393 break;
1394 case OBJ_REF_DELTA:
2b87c45b 1395 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1396 if (*delta_chain_length == 0)
1397 hashcpy(base_sha1, next_sha1);
2b87c45b 1398 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1399 break;
1400 }
43057304 1401 (*delta_chain_length)++;
2b87c45b 1402 curpos = obj_offset;
21666f1a 1403 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1404 }
ad8c80a5
JH
1405}
1406
c4001d92 1407static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1408 unsigned long *sizep)
1f688557 1409{
03e79c88 1410 struct pack_window *w_curs = NULL;
c4001d92
SP
1411 unsigned long size;
1412 off_t curpos = obj_offset;
21666f1a 1413 enum object_type type;
5db47c2b 1414
21666f1a 1415 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1416
21666f1a 1417 switch (type) {
eb32d236
NP
1418 case OBJ_OFS_DELTA:
1419 case OBJ_REF_DELTA:
21666f1a
NP
1420 type = packed_delta_info(p, &w_curs, curpos,
1421 type, obj_offset, sizep);
2b87c45b 1422 break;
a733cb60 1423 case OBJ_COMMIT:
a733cb60 1424 case OBJ_TREE:
a733cb60 1425 case OBJ_BLOB:
a733cb60 1426 case OBJ_TAG:
2b87c45b
NP
1427 if (sizep)
1428 *sizep = size;
a69d0943 1429 break;
1f688557 1430 default:
08a19d87 1431 die("pack %s contains unknown object type %d",
21666f1a 1432 p->pack_name, type);
1f688557 1433 }
2b87c45b 1434 unuse_pack(&w_curs);
21666f1a 1435 return type;
1f688557
JH
1436}
1437
eb950c19 1438static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1439 struct pack_window **w_curs,
c4001d92 1440 off_t curpos,
eb950c19 1441 unsigned long size)
de530aaa
SP
1442{
1443 int st;
1444 z_stream stream;
079afb18 1445 unsigned char *buffer, *in;
de530aaa
SP
1446
1447 buffer = xmalloc(size + 1);
1448 buffer[size] = 0;
1449 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1450 stream.next_out = buffer;
1451 stream.avail_out = size;
1452
1453 inflateInit(&stream);
079afb18 1454 do {
2b87c45b 1455 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1456 stream.next_in = in;
1457 st = inflate(&stream, Z_FINISH);
2b87c45b 1458 curpos += stream.next_in - in;
079afb18 1459 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1460 inflateEnd(&stream);
1461 if ((st != Z_STREAM_END) || stream.total_out != size) {
1462 free(buffer);
1463 return NULL;
1464 }
1465
1466 return buffer;
1467}
1468
e5e01619
LT
1469#define MAX_DELTA_CACHE (256)
1470
18bdec11 1471static size_t delta_base_cached;
5e08ecbf
NP
1472
1473static struct delta_base_cache_lru_list {
1474 struct delta_base_cache_lru_list *prev;
1475 struct delta_base_cache_lru_list *next;
1476} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1477
e5e01619 1478static struct delta_base_cache_entry {
5e08ecbf
NP
1479 struct delta_base_cache_lru_list lru;
1480 void *data;
e5e01619
LT
1481 struct packed_git *p;
1482 off_t base_offset;
1483 unsigned long size;
e5e01619
LT
1484 enum object_type type;
1485} delta_base_cache[MAX_DELTA_CACHE];
1486
1487static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1488{
1489 unsigned long hash;
1490
1491 hash = (unsigned long)p + (unsigned long)base_offset;
1492 hash += (hash >> 8) + (hash >> 16);
3358004a 1493 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1494}
1495
62f255ad 1496static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1497 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1498{
e5e01619
LT
1499 void *ret;
1500 unsigned long hash = pack_entry_hash(p, base_offset);
1501 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1502
1503 ret = ent->data;
1504 if (ret && ent->p == p && ent->base_offset == base_offset)
1505 goto found_cache_entry;
62f255ad 1506 return unpack_entry(p, base_offset, type, base_size);
e5e01619
LT
1507
1508found_cache_entry:
18bdec11 1509 if (!keep_cache) {
a0cba108 1510 ent->data = NULL;
5e08ecbf
NP
1511 ent->lru.next->prev = ent->lru.prev;
1512 ent->lru.prev->next = ent->lru.next;
18bdec11 1513 delta_base_cached -= ent->size;
182af834
PH
1514 } else {
1515 ret = xmemdupz(ent->data, ent->size);
a0cba108 1516 }
e5e01619
LT
1517 *type = ent->type;
1518 *base_size = ent->size;
1519 return ret;
62f255ad
LT
1520}
1521
18bdec11
SP
1522static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1523{
1524 if (ent->data) {
1525 free(ent->data);
1526 ent->data = NULL;
5e08ecbf
NP
1527 ent->lru.next->prev = ent->lru.prev;
1528 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1529 delta_base_cached -= ent->size;
1530 }
1531}
1532
62f255ad
LT
1533static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1534 void *base, unsigned long base_size, enum object_type type)
1535{
5e08ecbf 1536 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1537 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1538 struct delta_base_cache_lru_list *lru;
e5e01619 1539
18bdec11
SP
1540 release_delta_base_cache(ent);
1541 delta_base_cached += base_size;
5e08ecbf
NP
1542
1543 for (lru = delta_base_cache_lru.next;
1544 delta_base_cached > delta_base_cache_limit
1545 && lru != &delta_base_cache_lru;
1546 lru = lru->next) {
1547 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1548 if (f->type == OBJ_BLOB)
1549 release_delta_base_cache(f);
1550 }
5e08ecbf
NP
1551 for (lru = delta_base_cache_lru.next;
1552 delta_base_cached > delta_base_cache_limit
1553 && lru != &delta_base_cache_lru;
1554 lru = lru->next) {
1555 struct delta_base_cache_entry *f = (void *)lru;
1556 release_delta_base_cache(f);
1557 }
18bdec11 1558
e5e01619
LT
1559 ent->p = p;
1560 ent->base_offset = base_offset;
1561 ent->type = type;
1562 ent->data = base;
1563 ent->size = base_size;
5e08ecbf
NP
1564 ent->lru.next = &delta_base_cache_lru;
1565 ent->lru.prev = delta_base_cache_lru.prev;
1566 delta_base_cache_lru.prev->next = &ent->lru;
1567 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1568}
1569
eb950c19 1570static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1571 struct pack_window **w_curs,
c4001d92 1572 off_t curpos,
1f688557 1573 unsigned long delta_size,
c4001d92 1574 off_t obj_offset,
21666f1a 1575 enum object_type *type,
eb950c19 1576 unsigned long *sizep)
1f688557 1577{
7c3e8be3 1578 void *delta_data, *result, *base;
c4001d92
SP
1579 unsigned long base_size;
1580 off_t base_offset;
43057304 1581
21666f1a 1582 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
a0cba108 1583 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
67686d95 1584 if (!base)
c4001d92
SP
1585 die("failed to read delta base object"
1586 " at %"PRIuMAX" from %s",
1587 (uintmax_t)base_offset, p->pack_name);
67686d95 1588
2b87c45b 1589 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
9064d87b
SP
1590 if (!delta_data)
1591 die("failed to unpack compressed delta"
1592 " at %"PRIuMAX" from %s",
1593 (uintmax_t)curpos, p->pack_name);
1f688557
JH
1594 result = patch_delta(base, base_size,
1595 delta_data, delta_size,
21666f1a 1596 sizep);
1f688557
JH
1597 if (!result)
1598 die("failed to apply delta");
1599 free(delta_data);
62f255ad 1600 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1601 return result;
1602}
1603
c4001d92 1604void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1605 enum object_type *type, unsigned long *sizep)
1f688557 1606{
03e79c88 1607 struct pack_window *w_curs = NULL;
c4001d92 1608 off_t curpos = obj_offset;
21666f1a 1609 void *data;
1f688557 1610
21666f1a
NP
1611 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1612 switch (*type) {
eb32d236
NP
1613 case OBJ_OFS_DELTA:
1614 case OBJ_REF_DELTA:
21666f1a
NP
1615 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1616 obj_offset, type, sizep);
4d703a1a 1617 break;
a733cb60 1618 case OBJ_COMMIT:
a733cb60 1619 case OBJ_TREE:
a733cb60 1620 case OBJ_BLOB:
a733cb60 1621 case OBJ_TAG:
21666f1a 1622 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1623 break;
1f688557 1624 default:
21666f1a 1625 die("unknown object type %i in %s", *type, p->pack_name);
1f688557 1626 }
03e79c88 1627 unuse_pack(&w_curs);
21666f1a 1628 return data;
1f688557
JH
1629}
1630
d079837e 1631const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1632 uint32_t n)
9a217f2a 1633{
42873078 1634 const unsigned char *index = p->index_data;
d079837e
SP
1635 if (!index) {
1636 if (open_pack_index(p))
1637 return NULL;
1638 index = p->index_data;
1639 }
57059091 1640 if (n >= p->num_objects)
d72308e0 1641 return NULL;
74e34e1f
NP
1642 index += 4 * 256;
1643 if (p->index_version == 1) {
1644 return index + 24 * n + 4;
1645 } else {
1646 index += 8;
1647 return index + 20 * n;
1648 }
1649}
1650
1651static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1652{
1653 const unsigned char *index = p->index_data;
1654 index += 4 * 256;
1655 if (p->index_version == 1) {
1656 return ntohl(*((uint32_t *)(index + 24 * n)));
1657 } else {
1658 uint32_t off;
1659 index += 8 + p->num_objects * (20 + 4);
1660 off = ntohl(*((uint32_t *)(index + 4 * n)));
1661 if (!(off & 0x80000000))
1662 return off;
1663 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1664 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1665 ntohl(*((uint32_t *)(index + 4)));
1666 }
9a217f2a
JH
1667}
1668
c4001d92 1669off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1670 struct packed_git *p)
1f688557 1671{
42873078 1672 const uint32_t *level1_ofs = p->index_data;
42873078 1673 const unsigned char *index = p->index_data;
74e34e1f 1674 unsigned hi, lo;
42873078 1675
d079837e
SP
1676 if (!index) {
1677 if (open_pack_index(p))
1678 return 0;
1679 level1_ofs = p->index_data;
1680 index = p->index_data;
1681 }
74e34e1f
NP
1682 if (p->index_version > 1) {
1683 level1_ofs += 2;
1684 index += 8;
1685 }
42873078 1686 index += 4 * 256;
74e34e1f
NP
1687 hi = ntohl(level1_ofs[*sha1]);
1688 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1f688557
JH
1689
1690 do {
74e34e1f
NP
1691 unsigned mi = (lo + hi) / 2;
1692 unsigned x = (p->index_version > 1) ? (mi * 20) : (mi * 24 + 4);
1693 int cmp = hashcmp(index + x, sha1);
43057304 1694 if (!cmp)
74e34e1f 1695 return nth_packed_object_offset(p, mi);
1f688557
JH
1696 if (cmp > 0)
1697 hi = mi;
1698 else
1699 lo = mi+1;
1700 } while (lo < hi);
1701 return 0;
1702}
1703
000dfd3f 1704int matches_pack_name(struct packed_git *p, const char *name)
d4ff6d92
SP
1705{
1706 const char *last_c, *c;
1707
000dfd3f
JH
1708 if (!strcmp(p->pack_name, name))
1709 return 1;
d4ff6d92
SP
1710
1711 for (c = p->pack_name, last_c = c; *c;)
1712 if (*c == '/')
1713 last_c = ++c;
1714 else
1715 ++c;
000dfd3f
JH
1716 if (!strcmp(last_c, name))
1717 return 1;
d4ff6d92 1718
000dfd3f 1719 return 0;
d4ff6d92
SP
1720}
1721
106d710b 1722static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1723{
f7c22cc6 1724 static struct packed_git *last_found = (void *)1;
1f688557 1725 struct packed_git *p;
c4001d92 1726 off_t offset;
43057304 1727
1f688557 1728 prepare_packed_git();
f7c22cc6
NP
1729 if (!packed_git)
1730 return 0;
1731 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1732
f7c22cc6 1733 do {
106d710b
JH
1734 if (ignore_packed) {
1735 const char **ig;
1736 for (ig = ignore_packed; *ig; ig++)
000dfd3f 1737 if (matches_pack_name(p, *ig))
106d710b
JH
1738 break;
1739 if (*ig)
f7c22cc6 1740 goto next;
106d710b 1741 }
f7c22cc6 1742
43057304
NP
1743 offset = find_pack_entry_one(sha1, p);
1744 if (offset) {
c715f783
SP
1745 /*
1746 * We are about to tell the caller where they can
1747 * locate the requested object. We better make
1748 * sure the packfile is still here and can be
1749 * accessed before supplying that answer, as
1750 * it may have been deleted since the index
1751 * was loaded!
1752 */
1753 if (p->pack_fd == -1 && open_packed_git(p)) {
1754 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1755 goto next;
c715f783 1756 }
43057304
NP
1757 e->offset = offset;
1758 e->p = p;
1759 hashcpy(e->sha1, sha1);
f7c22cc6 1760 last_found = p;
1f688557 1761 return 1;
43057304 1762 }
f7c22cc6
NP
1763
1764 next:
1765 if (p == last_found)
1766 p = packed_git;
1767 else
1768 p = p->next;
1769 if (p == last_found)
1770 p = p->next;
1771 } while (p);
1f688557
JH
1772 return 0;
1773}
1774
a6080a0a 1775struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1776 struct packed_git *packs)
1777{
1778 struct packed_git *p;
bf592c50
DB
1779
1780 for (p = packs; p; p = p->next) {
43057304 1781 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1782 return p;
1783 }
1784 return NULL;
21666f1a 1785
bf592c50
DB
1786}
1787
21666f1a 1788static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1789{
36e4d74a 1790 int status;
65c2e0c3
JH
1791 unsigned long mapsize, size;
1792 void *map;
1793 z_stream stream;
d65a16f6 1794 char hdr[32];
65c2e0c3 1795
bb6b8e4f 1796 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1797 if (!map)
1798 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1799 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1800 status = error("unable to unpack %s header",
1801 sha1_to_hex(sha1));
21666f1a 1802 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1803 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1804 else if (sizep)
1805 *sizep = size;
65c2e0c3
JH
1806 inflateEnd(&stream);
1807 munmap(map, mapsize);
1808 return status;
1809}
1810
21666f1a 1811int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1812{
f0df4ed5
JS
1813 struct pack_entry e;
1814
1815 if (!find_pack_entry(sha1, &e, NULL)) {
1816 reprepare_packed_git();
1817 if (!find_pack_entry(sha1, &e, NULL))
21666f1a 1818 return sha1_loose_object_info(sha1, sizep);
f0df4ed5 1819 }
21666f1a 1820 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1821}
1822
21666f1a
NP
1823static void *read_packed_sha1(const unsigned char *sha1,
1824 enum object_type *type, unsigned long *size)
1f688557
JH
1825{
1826 struct pack_entry e;
1827
8276c007 1828 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1829 return NULL;
8276c007 1830 else
a0cba108 1831 return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1f688557
JH
1832}
1833
d66b37bb
JH
1834/*
1835 * This is meant to hold a *small* number of objects that you would
1836 * want read_sha1_file() to be able to return, but yet you do not want
1837 * to write them into the object store (e.g. a browse-only
1838 * application).
1839 */
1840static struct cached_object {
1841 unsigned char sha1[20];
21666f1a 1842 enum object_type type;
d66b37bb
JH
1843 void *buf;
1844 unsigned long size;
1845} *cached_objects;
1846static int cached_object_nr, cached_object_alloc;
1847
346245a1
JK
1848static struct cached_object empty_tree = {
1849 /* empty tree sha1: 4b825dc642cb6eb9a060e54bf8d69288fbee4904 */
1850 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60"
1851 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04",
1852 OBJ_TREE,
1853 "",
1854 0
1855};
1856
d66b37bb
JH
1857static struct cached_object *find_cached_object(const unsigned char *sha1)
1858{
1859 int i;
1860 struct cached_object *co = cached_objects;
1861
1862 for (i = 0; i < cached_object_nr; i++, co++) {
1863 if (!hashcmp(co->sha1, sha1))
1864 return co;
1865 }
346245a1
JK
1866 if (!hashcmp(sha1, empty_tree.sha1))
1867 return &empty_tree;
d66b37bb
JH
1868 return NULL;
1869}
1870
21666f1a
NP
1871int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1872 unsigned char *sha1)
d66b37bb
JH
1873{
1874 struct cached_object *co;
1875
21666f1a 1876 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
1877 if (has_sha1_file(sha1) || find_cached_object(sha1))
1878 return 0;
1879 if (cached_object_alloc <= cached_object_nr) {
1880 cached_object_alloc = alloc_nr(cached_object_alloc);
1881 cached_objects = xrealloc(cached_objects,
1882 sizeof(*cached_objects) *
1883 cached_object_alloc);
1884 }
1885 co = &cached_objects[cached_object_nr++];
1886 co->size = len;
21666f1a 1887 co->type = type;
efa13f7b
JH
1888 co->buf = xmalloc(len);
1889 memcpy(co->buf, buf, len);
d66b37bb
JH
1890 hashcpy(co->sha1, sha1);
1891 return 0;
1892}
1893
21666f1a
NP
1894void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
1895 unsigned long *size)
0fcfd160
LT
1896{
1897 unsigned long mapsize;
1898 void *map, *buf;
d66b37bb
JH
1899 struct cached_object *co;
1900
1901 co = find_cached_object(sha1);
1902 if (co) {
21666f1a 1903 *type = co->type;
d66b37bb 1904 *size = co->size;
182af834 1905 return xmemdupz(co->buf, co->size);
d66b37bb 1906 }
0fcfd160 1907
8276c007
PE
1908 buf = read_packed_sha1(sha1, type, size);
1909 if (buf)
1910 return buf;
bb6b8e4f 1911 map = map_sha1_file(sha1, &mapsize);
0fcfd160 1912 if (map) {
7efbff75 1913 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
1914 munmap(map, mapsize);
1915 return buf;
1916 }
637cdd9d 1917 reprepare_packed_git();
8276c007 1918 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
1919}
1920
40469ee9 1921void *read_object_with_reference(const unsigned char *sha1,
21666f1a 1922 const char *required_type_name,
40469ee9
JH
1923 unsigned long *size,
1924 unsigned char *actual_sha1_return)
f4913f91 1925{
21666f1a 1926 enum object_type type, required_type;
f4913f91
JH
1927 void *buffer;
1928 unsigned long isize;
40469ee9 1929 unsigned char actual_sha1[20];
f4913f91 1930
21666f1a 1931 required_type = type_from_string(required_type_name);
e702496e 1932 hashcpy(actual_sha1, sha1);
40469ee9
JH
1933 while (1) {
1934 int ref_length = -1;
1935 const char *ref_type = NULL;
f4913f91 1936
21666f1a 1937 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
1938 if (!buffer)
1939 return NULL;
21666f1a 1940 if (type == required_type) {
40469ee9
JH
1941 *size = isize;
1942 if (actual_sha1_return)
e702496e 1943 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1944 return buffer;
1945 }
1946 /* Handle references */
21666f1a 1947 else if (type == OBJ_COMMIT)
40469ee9 1948 ref_type = "tree ";
21666f1a 1949 else if (type == OBJ_TAG)
40469ee9
JH
1950 ref_type = "object ";
1951 else {
1952 free(buffer);
1953 return NULL;
1954 }
1955 ref_length = strlen(ref_type);
f4913f91 1956
50974ec9
MK
1957 if (ref_length + 40 > isize ||
1958 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1959 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1960 free(buffer);
1961 return NULL;
1962 }
1cf58e72 1963 free(buffer);
40469ee9
JH
1964 /* Now we have the ID of the referred-to object in
1965 * actual_sha1. Check again. */
f4913f91 1966 }
f4913f91
JH
1967}
1968
ce9fbf16 1969static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 1970 const char *type, unsigned char *sha1,
d65a16f6 1971 char *hdr, int *hdrlen)
d410c0f5
JH
1972{
1973 SHA_CTX c;
1974
1975 /* Generate the header */
d65a16f6 1976 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
1977
1978 /* Sha1.. */
1979 SHA1_Init(&c);
1980 SHA1_Update(&c, hdr, *hdrlen);
1981 SHA1_Update(&c, buf, len);
1982 SHA1_Final(sha1, &c);
d410c0f5
JH
1983}
1984
230f1322
LT
1985/*
1986 * Link the tempfile to the final place, possibly creating the
1987 * last directory level as you do so.
1988 *
1989 * Returns the errno on failure, 0 on success.
1990 */
839837b9 1991static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1992{
1993 int ret;
756aaf4a 1994 char *dir;
230f1322
LT
1995
1996 if (!link(tmpfile, filename))
1997 return 0;
1998
1999 /*
756aaf4a 2000 * Try to mkdir the last path component if that failed.
230f1322
LT
2001 *
2002 * Re-try the "link()" regardless of whether the mkdir
2003 * succeeds, since a race might mean that somebody
2004 * else succeeded.
2005 */
2006 ret = errno;
756aaf4a
SP
2007 dir = strrchr(filename, '/');
2008 if (dir) {
2009 *dir = 0;
866cae0d 2010 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
91c23e48 2011 *dir = '/';
756aaf4a 2012 return -2;
91c23e48 2013 }
756aaf4a
SP
2014 *dir = '/';
2015 if (!link(tmpfile, filename))
2016 return 0;
2017 ret = errno;
230f1322
LT
2018 }
2019 return ret;
2020}
2021
2022/*
2023 * Move the just written object into its final resting place
2024 */
839837b9 2025int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
2026{
2027 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
2028
2029 /*
2030 * Coda hack - coda doesn't like cross-directory links,
2031 * so we fall back to a rename, which will mean that it
2032 * won't be able to check collisions, but that's not a
2033 * big deal.
2034 *
2035 * The same holds for FAT formatted media.
2036 *
2037 * When this succeeds, we just return 0. We have nothing
2038 * left to unlink.
2039 */
2040 if (ret && ret != EEXIST) {
2041 if (!rename(tmpfile, filename))
230f1322 2042 return 0;
9e48b389 2043 ret = errno;
230f1322
LT
2044 }
2045 unlink(tmpfile);
2046 if (ret) {
2047 if (ret != EEXIST) {
916d081b 2048 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2049 }
2050 /* FIXME!!! Collision check here ? */
2051 }
2052
2053 return 0;
2054}
2055
4d548150
LT
2056static int write_buffer(int fd, const void *buf, size_t len)
2057{
d34cf19b 2058 if (write_in_full(fd, buf, len) < 0)
93822c22 2059 return error("file write error (%s)", strerror(errno));
4d548150
LT
2060 return 0;
2061}
2062
ce9fbf16 2063int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2064 unsigned char *sha1)
2065{
d65a16f6 2066 char hdr[32];
abdc3fc8
RS
2067 int hdrlen;
2068 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2069 return 0;
2070}
2071
bf0f910d 2072int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160 2073{
ac54c277 2074 int size, ret;
bf0f910d 2075 unsigned char *compressed;
0fcfd160
LT
2076 z_stream stream;
2077 unsigned char sha1[20];
706bc531 2078 char *filename;
aac17941 2079 static char tmpfile[PATH_MAX];
d65a16f6 2080 char hdr[32];
230f1322 2081 int fd, hdrlen;
a44c9a5e 2082
d410c0f5
JH
2083 /* Normally if we have it in the pack then we do not bother writing
2084 * it out into .git/objects/??/?{38} file.
2085 */
972a9155
RS
2086 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2087 filename = sha1_file_name(sha1);
706bc531 2088 if (returnsha1)
e702496e 2089 hashcpy(returnsha1, sha1);
d410c0f5
JH
2090 if (has_sha1_file(sha1))
2091 return 0;
aac17941
LT
2092 fd = open(filename, O_RDONLY);
2093 if (fd >= 0) {
706bc531 2094 /*
aac17941
LT
2095 * FIXME!!! We might do collision checking here, but we'd
2096 * need to uncompress the old file and check it. Later.
706bc531 2097 */
aac17941 2098 close(fd);
706bc531
LT
2099 return 0;
2100 }
2101
aac17941 2102 if (errno != ENOENT) {
916d081b 2103 return error("sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
2104 }
2105
0e55181f 2106 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
ace1534d 2107
aac17941
LT
2108 fd = mkstemp(tmpfile);
2109 if (fd < 0) {
916d081b
PB
2110 if (errno == EPERM)
2111 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2112 else
2113 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2114 }
2115
0fcfd160
LT
2116 /* Set it up */
2117 memset(&stream, 0, sizeof(stream));
12f6c308 2118 deflateInit(&stream, zlib_compression_level);
93821bd9 2119 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2120 compressed = xmalloc(size);
0fcfd160
LT
2121
2122 /* Compress it */
0fcfd160
LT
2123 stream.next_out = compressed;
2124 stream.avail_out = size;
a44c9a5e
LT
2125
2126 /* First header.. */
d65a16f6 2127 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2128 stream.avail_in = hdrlen;
726f852b
NP
2129 while (deflate(&stream, 0) == Z_OK)
2130 /* nothing */;
a44c9a5e
LT
2131
2132 /* Then the data itself.. */
2133 stream.next_in = buf;
2134 stream.avail_in = len;
ac54c277
LT
2135 ret = deflate(&stream, Z_FINISH);
2136 if (ret != Z_STREAM_END)
2137 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2138
2139 ret = deflateEnd(&stream);
2140 if (ret != Z_OK)
2141 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2142
0fcfd160
LT
2143 size = stream.total_out;
2144
4d548150
LT
2145 if (write_buffer(fd, compressed, size) < 0)
2146 die("unable to write sha1 file");
aac17941 2147 fchmod(fd, 0444);
e82973cf
JH
2148 if (close(fd))
2149 die("unable to write sha1 file");
383f85b7 2150 free(compressed);
0fcfd160 2151
230f1322 2152 return move_temp_to_file(tmpfile, filename);
0fcfd160 2153}
8237b185 2154
4d548150
LT
2155/*
2156 * We need to unpack and recompress the object for writing
2157 * it out to a different file.
2158 */
2159static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 2160{
4d548150 2161 size_t size;
a5eda52b 2162 z_stream stream;
4d548150
LT
2163 unsigned char *unpacked;
2164 unsigned long len;
21666f1a 2165 enum object_type type;
d65a16f6 2166 char hdr[32];
4d548150
LT
2167 int hdrlen;
2168 void *buf;
bfc66daf 2169
a9486b02 2170 /* need to unpack and recompress it by itself */
21666f1a 2171 unpacked = read_packed_sha1(sha1, &type, &len);
8276c007
PE
2172 if (!unpacked)
2173 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
a5eda52b 2174
21666f1a 2175 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
a5eda52b 2176
4d548150
LT
2177 /* Set it up */
2178 memset(&stream, 0, sizeof(stream));
12f6c308 2179 deflateInit(&stream, zlib_compression_level);
4d548150
LT
2180 size = deflateBound(&stream, len + hdrlen);
2181 buf = xmalloc(size);
a5eda52b 2182
4d548150
LT
2183 /* Compress it */
2184 stream.next_out = buf;
2185 stream.avail_out = size;
a5eda52b 2186
4d548150
LT
2187 /* First header.. */
2188 stream.next_in = (void *)hdr;
2189 stream.avail_in = hdrlen;
2190 while (deflate(&stream, 0) == Z_OK)
2191 /* nothing */;
bfc66daf 2192
4d548150
LT
2193 /* Then the data itself.. */
2194 stream.next_in = unpacked;
2195 stream.avail_in = len;
2196 while (deflate(&stream, Z_FINISH) == Z_OK)
2197 /* nothing */;
2198 deflateEnd(&stream);
2199 free(unpacked);
bfc66daf 2200
4d548150
LT
2201 *objsize = stream.total_out;
2202 return buf;
2203}
2204
2205int write_sha1_to_fd(int fd, const unsigned char *sha1)
2206{
2207 int retval;
2208 unsigned long objsize;
bb6b8e4f 2209 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
2210
2211 if (buf) {
2212 retval = write_buffer(fd, buf, objsize);
2213 munmap(buf, objsize);
2214 return retval;
2215 }
2216
2217 buf = repack_object(sha1, &objsize);
2218 retval = write_buffer(fd, buf, objsize);
2219 free(buf);
2220 return retval;
a5eda52b
DB
2221}
2222
70b9829e
DB
2223int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
2224 size_t bufsize, size_t *bufposn)
8237b185 2225{
230f1322 2226 char tmpfile[PATH_MAX];
8237b185
DB
2227 int local;
2228 z_stream stream;
2229 unsigned char real_sha1[20];
bf0f910d 2230 unsigned char discard[4096];
8237b185
DB
2231 int ret;
2232 SHA_CTX c;
2233
0e55181f 2234 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
8237b185 2235
230f1322 2236 local = mkstemp(tmpfile);
916d081b
PB
2237 if (local < 0) {
2238 if (errno == EPERM)
2239 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2240 else
2241 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2242 }
8237b185
DB
2243
2244 memset(&stream, 0, sizeof(stream));
2245
2246 inflateInit(&stream);
2247
2248 SHA1_Init(&c);
2249
2250 do {
2251 ssize_t size;
70b9829e
DB
2252 if (*bufposn) {
2253 stream.avail_in = *bufposn;
96ad15ae 2254 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
2255 do {
2256 stream.next_out = discard;
2257 stream.avail_out = sizeof(discard);
2258 ret = inflate(&stream, Z_SYNC_FLUSH);
2259 SHA1_Update(&c, discard, sizeof(discard) -
2260 stream.avail_out);
2261 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
2262 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
2263 die("unable to write sha1 file");
70b9829e
DB
2264 memmove(buffer, buffer + *bufposn - stream.avail_in,
2265 stream.avail_in);
2266 *bufposn = stream.avail_in;
2267 if (ret != Z_OK)
2268 break;
2269 }
93d26e4c 2270 size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
2271 if (size <= 0) {
2272 close(local);
230f1322 2273 unlink(tmpfile);
8237b185
DB
2274 if (!size)
2275 return error("Connection closed?");
2276 perror("Reading from connection");
2277 return -1;
2278 }
70b9829e
DB
2279 *bufposn += size;
2280 } while (1);
8237b185
DB
2281 inflateEnd(&stream);
2282
b5b8d814 2283 fchmod(local, 0444);
0d315468
JM
2284 if (close(local) != 0)
2285 die("unable to write sha1 file");
8237b185
DB
2286 SHA1_Final(real_sha1, &c);
2287 if (ret != Z_STREAM_END) {
230f1322 2288 unlink(tmpfile);
8237b185
DB
2289 return error("File %s corrupted", sha1_to_hex(sha1));
2290 }
a89fccd2 2291 if (hashcmp(sha1, real_sha1)) {
230f1322 2292 unlink(tmpfile);
bd2afde8 2293 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 2294 }
230f1322
LT
2295
2296 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
2297}
2298
bf592c50
DB
2299int has_pack_index(const unsigned char *sha1)
2300{
2301 struct stat st;
2302 if (stat(sha1_pack_index_name(sha1), &st))
2303 return 0;
2304 return 1;
2305}
2306
2307int has_pack_file(const unsigned char *sha1)
2308{
2309 struct stat st;
2310 if (stat(sha1_pack_name(sha1), &st))
2311 return 0;
2312 return 1;
2313}
2314
106d710b 2315int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2316{
2317 struct pack_entry e;
106d710b 2318 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2319}
2320
8237b185
DB
2321int has_sha1_file(const unsigned char *sha1)
2322{
8237b185 2323 struct stat st;
1f688557
JH
2324 struct pack_entry e;
2325
106d710b 2326 if (find_pack_entry(sha1, &e, NULL))
1f688557 2327 return 1;
ab90ea5d 2328 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 2329}
74400e71 2330
e7332f96
BE
2331int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2332{
fd17f5b5 2333 struct strbuf buf;
e7332f96 2334 int ret;
e7332f96 2335
fd17f5b5
PH
2336 strbuf_init(&buf, 0);
2337 if (strbuf_read(&buf, fd, 4096) < 0) {
2338 strbuf_release(&buf);
024510c8
DB
2339 return -1;
2340 }
e7332f96 2341
024510c8 2342 if (!type)
8e440259 2343 type = blob_type;
024510c8 2344 if (write_object)
fd17f5b5 2345 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
abdc3fc8 2346 else
fd17f5b5
PH
2347 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
2348 strbuf_release(&buf);
2349
024510c8
DB
2350 return ret;
2351}
2352
edaec3fb 2353int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
53bca91a 2354 enum object_type type, const char *path)
74400e71 2355{
dc49cd76 2356 size_t size = xsize_t(st->st_size);
3a55602e 2357 void *buf = NULL;
6c510bee 2358 int ret, re_allocated = 0;
74400e71 2359
74400e71 2360 if (size)
c4712e45 2361 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 2362 close(fd);
74400e71 2363
7672db20 2364 if (!type)
edaec3fb 2365 type = OBJ_BLOB;
6c510bee
LT
2366
2367 /*
2368 * Convert blobs to git internal format
2369 */
d0d8e14d 2370 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
5ecd293d
PH
2371 struct strbuf nbuf;
2372 strbuf_init(&nbuf, 0);
21e5ad50
SP
2373 if (convert_to_git(path, buf, size, &nbuf,
2374 write_object ? safe_crlf : 0)) {
ac78e548 2375 munmap(buf, size);
b315c5c0 2376 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2377 re_allocated = 1;
2378 }
2379 }
2380
7672db20 2381 if (write_object)
edaec3fb 2382 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2383 else
edaec3fb 2384 ret = hash_sha1_file(buf, size, typename(type), sha1);
6c510bee
LT
2385 if (re_allocated) {
2386 free(buf);
2387 return ret;
2388 }
aac17941
LT
2389 if (size)
2390 munmap(buf, size);
2391 return ret;
74400e71 2392}
ec1fcc16
JH
2393
2394int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2395{
2396 int fd;
2397 char *target;
dc49cd76 2398 size_t len;
ec1fcc16
JH
2399
2400 switch (st->st_mode & S_IFMT) {
2401 case S_IFREG:
2402 fd = open(path, O_RDONLY);
2403 if (fd < 0)
2404 return error("open(\"%s\"): %s", path,
2405 strerror(errno));
53bca91a 2406 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2407 return error("%s: failed to insert into database",
2408 path);
2409 break;
2410 case S_IFLNK:
dc49cd76
SP
2411 len = xsize_t(st->st_size);
2412 target = xmalloc(len + 1);
2413 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2414 char *errstr = strerror(errno);
2415 free(target);
2416 return error("readlink(\"%s\"): %s", path,
2417 errstr);
2418 }
abdc3fc8 2419 if (!write_object)
dc49cd76
SP
2420 hash_sha1_file(target, len, blob_type, sha1);
2421 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2422 return error("%s: failed to insert into database",
2423 path);
2424 free(target);
2425 break;
f35a6d3b
LT
2426 case S_IFDIR:
2427 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2428 default:
2429 return error("%s: unsupported file type", path);
2430 }
2431 return 0;
2432}
a69e5429
JH
2433
2434int read_pack_header(int fd, struct pack_header *header)
2435{
2436 char *c = (char*)header;
2437 ssize_t remaining = sizeof(struct pack_header);
2438 do {
2439 ssize_t r = xread(fd, c, remaining);
2440 if (r <= 0)
2441 /* "eof before pack header was fully read" */
2442 return PH_ERROR_EOF;
2443 remaining -= r;
2444 c += r;
2445 } while (remaining > 0);
2446 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2447 /* "protocol error (pack signature mismatch detected)" */
2448 return PH_ERROR_PACK_SIGNATURE;
2449 if (!pack_version_ok(header->hdr_version))
2450 /* "protocol error (pack version unsupported)" */
2451 return PH_ERROR_PROTOCOL;
2452 return 0;
2453}