Fix grammar nits in documentation and in code comments.
[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
03e79c88 614void unuse_pack(struct pack_window **w_cursor)
f9253394 615{
03e79c88
SP
616 struct pack_window *w = *w_cursor;
617 if (w) {
618 w->inuse_cnt--;
619 *w_cursor = NULL;
620 }
1f688557
JH
621}
622
3cf8b462
SP
623/*
624 * Do not call this directly as this leaks p->pack_fd on error return;
625 * call open_packed_git() instead.
626 */
627static int open_packed_git_1(struct packed_git *p)
1f688557 628{
9bc879c1
SP
629 struct stat st;
630 struct pack_header hdr;
631 unsigned char sha1[20];
632 unsigned char *idx_sha1;
2c039da8 633 long fd_flag;
9bc879c1 634
d079837e
SP
635 if (!p->index_data && open_pack_index(p))
636 return error("packfile %s index unavailable", p->pack_name);
637
9bc879c1
SP
638 p->pack_fd = open(p->pack_name, O_RDONLY);
639 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 640 return -1;
9bc879c1
SP
641
642 /* If we created the struct before we had the pack we lack size. */
bf592c50 643 if (!p->pack_size) {
bf592c50 644 if (!S_ISREG(st.st_mode))
072db278 645 return error("packfile %s not a regular file", p->pack_name);
bf592c50 646 p->pack_size = st.st_size;
9bc879c1 647 } else if (p->pack_size != st.st_size)
072db278 648 return error("packfile %s size changed", p->pack_name);
9bc879c1 649
2c039da8
JH
650 /* We leave these file descriptors open with sliding mmap;
651 * there is no point keeping them open across exec(), though.
652 */
653 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
654 if (fd_flag < 0)
072db278 655 return error("cannot determine file descriptor flags");
2c039da8
JH
656 fd_flag |= FD_CLOEXEC;
657 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 658 return error("cannot set FD_CLOEXEC");
2c039da8 659
9bc879c1 660 /* Verify we recognize this pack file format. */
e6e2bd62 661 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 662 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 663 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 664 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 665 if (!pack_version_ok(hdr.hdr_version))
072db278 666 return error("packfile %s is version %u and not supported"
9bc879c1
SP
667 " (try upgrading GIT to a newer version)",
668 p->pack_name, ntohl(hdr.hdr_version));
669
670 /* Verify the pack matches its index. */
57059091 671 if (p->num_objects != ntohl(hdr.hdr_entries))
072db278 672 return error("packfile %s claims to have %u objects"
57059091
NP
673 " while index indicates %u objects",
674 p->pack_name, ntohl(hdr.hdr_entries),
675 p->num_objects);
9bc879c1 676 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 677 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 678 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 679 return error("packfile %s signature is unavailable", p->pack_name);
42873078 680 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 681 if (hashcmp(sha1, idx_sha1))
072db278
SP
682 return error("packfile %s does not match index", p->pack_name);
683 return 0;
9bc879c1
SP
684}
685
3cf8b462
SP
686static int open_packed_git(struct packed_git *p)
687{
688 if (!open_packed_git_1(p))
689 return 0;
690 if (p->pack_fd != -1) {
691 close(p->pack_fd);
692 p->pack_fd = -1;
693 }
694 return -1;
695}
696
c4001d92 697static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
698{
699 /* We must promise at least 20 bytes (one hash) after the
700 * offset is available from this window, otherwise the offset
701 * is not actually in this window and a different window (which
702 * has that one hash excess) must be used. This is to support
703 * the object header and delta base parsing routines below.
704 */
705 off_t win_off = win->offset;
706 return win_off <= offset
707 && (offset + 20) <= (win_off + win->len);
708}
709
03e79c88
SP
710unsigned char* use_pack(struct packed_git *p,
711 struct pack_window **w_cursor,
c4001d92 712 off_t offset,
03e79c88 713 unsigned int *left)
9bc879c1 714{
60bb8b14 715 struct pack_window *win = *w_cursor;
03e79c88 716
072db278
SP
717 if (p->pack_fd == -1 && open_packed_git(p))
718 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14
SP
719
720 /* Since packfiles end in a hash of their content and its
721 * pointless to ask for an offset into the middle of that
722 * hash, and the in_window function above wouldn't match
723 * don't allow an offset too close to the end of the file.
724 */
725 if (offset > (p->pack_size - 20))
726 die("offset beyond end of packfile (truncated pack?)");
727
728 if (!win || !in_window(win, offset)) {
729 if (win)
730 win->inuse_cnt--;
731 for (win = p->windows; win; win = win->next) {
732 if (in_window(win, offset))
733 break;
734 }
735 if (!win) {
78a28df9 736 size_t window_align = packed_git_window_size / 2;
dc49cd76 737 off_t len;
60bb8b14 738 win = xcalloc(1, sizeof(*win));
78a28df9 739 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
740 len = p->pack_size - win->offset;
741 if (len > packed_git_window_size)
742 len = packed_git_window_size;
743 win->len = (size_t)len;
60bb8b14 744 pack_mapped += win->len;
11daf39b 745 while (packed_git_limit < pack_mapped
d1efefa4 746 && unuse_one_window(p, p->pack_fd))
60bb8b14 747 ; /* nothing */
c4712e45 748 win->base = xmmap(NULL, win->len,
60bb8b14
SP
749 PROT_READ, MAP_PRIVATE,
750 p->pack_fd, win->offset);
751 if (win->base == MAP_FAILED)
73b4e4be
SP
752 die("packfile %s cannot be mapped: %s",
753 p->pack_name,
754 strerror(errno));
a53128b6
SP
755 pack_mmap_calls++;
756 pack_open_windows++;
757 if (pack_mapped > peak_pack_mapped)
758 peak_pack_mapped = pack_mapped;
759 if (pack_open_windows > peak_pack_open_windows)
760 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
761 win->next = p->windows;
762 p->windows = win;
763 }
1f688557 764 }
03e79c88
SP
765 if (win != *w_cursor) {
766 win->last_used = pack_used_ctr++;
767 win->inuse_cnt++;
768 *w_cursor = win;
769 }
60bb8b14 770 offset -= win->offset;
03e79c88 771 if (left)
dc49cd76 772 *left = win->len - xsize_t(offset);
03e79c88 773 return win->base + offset;
1f688557
JH
774}
775
42873078 776struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
777{
778 struct stat st;
42873078 779 struct packed_git *p = xmalloc(sizeof(*p) + path_len + 2);
1f688557 780
42873078
NP
781 /*
782 * Make sure a corresponding .pack file exists and that
783 * the index looks sane.
784 */
785 path_len -= strlen(".idx");
786 if (path_len < 1)
1f688557 787 return NULL;
42873078
NP
788 memcpy(p->pack_name, path, path_len);
789 strcpy(p->pack_name + path_len, ".pack");
d079837e 790 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 791 free(p);
1f688557
JH
792 return NULL;
793 }
42873078 794
1f688557
JH
795 /* ok, it looks sane as far as we can check without
796 * actually mapping the pack file.
797 */
d079837e
SP
798 p->index_version = 0;
799 p->index_data = NULL;
800 p->index_size = 0;
801 p->num_objects = 0;
1f688557 802 p->pack_size = st.st_size;
1f688557 803 p->next = NULL;
c41ee586 804 p->windows = NULL;
9bc879c1 805 p->pack_fd = -1;
9d835df2 806 p->pack_local = local;
b867092f 807 p->mtime = st.st_mtime;
42873078
NP
808 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
809 hashclr(p->sha1);
1f688557
JH
810 return p;
811}
812
bf592c50 813struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e
DB
814{
815 char *path = sha1_pack_index_name(sha1);
816 return parse_pack_index_file(sha1, path);
817}
818
42873078
NP
819struct packed_git *parse_pack_index_file(const unsigned char *sha1,
820 const char *idx_path)
bf592c50 821{
42873078
NP
822 const char *path = sha1_pack_name(sha1);
823 struct packed_git *p = xmalloc(sizeof(*p) + strlen(path) + 2);
bf592c50 824
42873078
NP
825 if (check_packed_git_idx(idx_path, p)) {
826 free(p);
bf592c50 827 return NULL;
42873078 828 }
bf592c50 829
bf592c50 830 strcpy(p->pack_name, path);
bf592c50 831 p->pack_size = 0;
bf592c50 832 p->next = NULL;
c41ee586 833 p->windows = NULL;
9bc879c1 834 p->pack_fd = -1;
e702496e 835 hashcpy(p->sha1, sha1);
bf592c50
DB
836 return p;
837}
838
839void install_packed_git(struct packed_git *pack)
840{
841 pack->next = packed_git;
842 packed_git = pack;
843}
844
9d835df2 845static void prepare_packed_git_one(char *objdir, int local)
1f688557 846{
9cb18f56
JM
847 /* Ensure that this buffer is large enough so that we can
848 append "/pack/" without clobbering the stack even if
849 strlen(objdir) were PATH_MAX. */
850 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
851 int len;
852 DIR *dir;
853 struct dirent *de;
854
855 sprintf(path, "%s/pack", objdir);
856 len = strlen(path);
857 dir = opendir(path);
b5b16990 858 if (!dir) {
26125f6b 859 if (errno != ENOENT)
bd2afde8 860 error("unable to open object pack directory: %s: %s",
26125f6b 861 path, strerror(errno));
1f688557 862 return;
b5b16990 863 }
1f688557
JH
864 path[len++] = '/';
865 while ((de = readdir(dir)) != NULL) {
866 int namelen = strlen(de->d_name);
867 struct packed_git *p;
868
5bb1cda5 869 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
870 continue;
871
9cb18f56
JM
872 if (len + namelen + 1 > sizeof(path))
873 continue;
874
54a15a8d 875 /* Don't reopen a pack we already have. */
1f688557 876 strcpy(path + len, de->d_name);
86f7780c
JK
877 for (p = packed_git; p; p = p->next) {
878 if (!memcmp(path, p->pack_name, len + namelen - 4))
879 break;
880 }
881 if (p)
882 continue;
54a15a8d
SP
883 /* See if it really is a valid .idx file with corresponding
884 * .pack file that we can map.
885 */
9d835df2 886 p = add_packed_git(path, len + namelen, local);
1f688557
JH
887 if (!p)
888 continue;
625e9421 889 install_packed_git(p);
1f688557 890 }
5b35bcd5 891 closedir(dir);
1f688557
JH
892}
893
b867092f
JH
894static int sort_pack(const void *a_, const void *b_)
895{
896 struct packed_git *a = *((struct packed_git **)a_);
897 struct packed_git *b = *((struct packed_git **)b_);
898 int st;
899
900 /*
901 * Local packs tend to contain objects specific to our
902 * variant of the project than remote ones. In addition,
903 * remote ones could be on a network mounted filesystem.
904 * Favor local ones for these reasons.
905 */
906 st = a->pack_local - b->pack_local;
907 if (st)
908 return -st;
909
910 /*
911 * Younger packs tend to contain more recent objects,
912 * and more recent objects tend to get accessed more
913 * often.
914 */
915 if (a->mtime < b->mtime)
916 return 1;
917 else if (a->mtime == b->mtime)
918 return 0;
919 return -1;
920}
921
922static void rearrange_packed_git(void)
923{
924 struct packed_git **ary, *p;
925 int i, n;
926
927 for (n = 0, p = packed_git; p; p = p->next)
928 n++;
929 if (n < 2)
930 return;
931
932 /* prepare an array of packed_git for easier sorting */
933 ary = xcalloc(n, sizeof(struct packed_git *));
934 for (n = 0, p = packed_git; p; p = p->next)
935 ary[n++] = p;
936
937 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
938
939 /* link them back again */
940 for (i = 0; i < n - 1; i++)
941 ary[i]->next = ary[i + 1];
942 ary[n - 1]->next = NULL;
943 packed_git = ary[0];
944
945 free(ary);
946}
947
637cdd9d 948static int prepare_packed_git_run_once = 0;
9a217f2a 949void prepare_packed_git(void)
1f688557 950{
d5a63b99 951 struct alternate_object_database *alt;
1f688557 952
637cdd9d 953 if (prepare_packed_git_run_once)
1f688557 954 return;
9d835df2 955 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 956 prepare_alt_odb();
d5a63b99 957 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 958 alt->name[-1] = 0;
9d835df2 959 prepare_packed_git_one(alt->base, 0);
1494e038 960 alt->name[-1] = '/';
1f688557 961 }
b867092f 962 rearrange_packed_git();
637cdd9d
JK
963 prepare_packed_git_run_once = 1;
964}
965
fc04c412 966void reprepare_packed_git(void)
637cdd9d
JK
967{
968 prepare_packed_git_run_once = 0;
969 prepare_packed_git();
1f688557
JH
970}
971
5d6ccf5c 972int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
973{
974 unsigned char real_sha1[20];
7cfb5f36 975 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 976 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
977}
978
4175e9e3 979static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 980{
0fcfd160
LT
981 struct stat st;
982 void *map;
144bde78 983 int fd;
ace1534d
JH
984 char *filename = find_sha1_file(sha1, &st);
985
986 if (!filename) {
ace1534d
JH
987 return NULL;
988 }
0fcfd160 989
144bde78 990 fd = open(filename, O_RDONLY | sha1_file_open_flag);
0fcfd160 991 if (fd < 0) {
144bde78
LT
992 /* See if it works without O_NOATIME */
993 switch (sha1_file_open_flag) {
994 default:
995 fd = open(filename, O_RDONLY);
996 if (fd >= 0)
997 break;
998 /* Fallthrough */
999 case 0:
144bde78
LT
1000 return NULL;
1001 }
1002
1f688557
JH
1003 /* If it failed once, it will probably fail again.
1004 * Stop using O_NOATIME
1005 */
144bde78 1006 sha1_file_open_flag = 0;
0fcfd160 1007 }
dc49cd76
SP
1008 *size = xsize_t(st.st_size);
1009 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
0fcfd160 1010 close(fd);
0fcfd160
LT
1011 return map;
1012}
1013
726f852b 1014static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1015{
1016 unsigned int word;
1017
1018 /*
1019 * Is it a zlib-compressed buffer? If so, the first byte
1020 * must be 0x78 (15-bit window size, deflated), and the
1021 * first 16-bit word is evenly divisible by 31
1022 */
1023 word = (map[0] << 8) + map[1];
1024 if (map[0] == 0x78 && !(word % 31))
1025 return 1;
1026 else
1027 return 0;
1028}
1029
72518e9c 1030unsigned long unpack_object_header_gently(const unsigned char *buf, unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1031{
ad1ed5ee 1032 unsigned shift;
93821bd9 1033 unsigned char c;
93821bd9 1034 unsigned long size;
ad1ed5ee
JH
1035 unsigned long used = 0;
1036
1037 c = buf[used++];
1038 *type = (c >> 4) & 7;
1039 size = c & 15;
1040 shift = 4;
1041 while (c & 0x80) {
1042 if (len <= used)
1043 return 0;
1044 if (sizeof(long) * 8 <= shift)
1045 return 0;
1046 c = buf[used++];
1047 size += (c & 0x7f) << shift;
1048 shift += 7;
1049 }
1050 *sizep = size;
1051 return used;
1052}
1053
1054static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1055{
1056 unsigned long size, used;
1057 static const char valid_loose_object_type[8] = {
1058 0, /* OBJ_EXT */
1059 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1060 0, /* "delta" and others are invalid in a loose object */
93821bd9 1061 };
ad1ed5ee 1062 enum object_type type;
93821bd9 1063
c4483576
LT
1064 /* Get the data stream */
1065 memset(stream, 0, sizeof(*stream));
1066 stream->next_in = map;
1067 stream->avail_in = mapsize;
1068 stream->next_out = buffer;
93821bd9
LT
1069 stream->avail_out = bufsiz;
1070
bb6b8e4f 1071 if (legacy_loose_object(map)) {
93821bd9
LT
1072 inflateInit(stream);
1073 return inflate(stream, 0);
1074 }
1075
726f852b
NP
1076
1077 /*
1078 * There used to be a second loose object header format which
1079 * was meant to mimic the in-pack format, allowing for direct
1080 * copy of the object data. This format turned up not to be
1081 * really worth it and we don't write it any longer. But we
1082 * can still read it.
1083 */
ad1ed5ee
JH
1084 used = unpack_object_header_gently(map, mapsize, &type, &size);
1085 if (!used || !valid_loose_object_type[type])
93821bd9 1086 return -1;
ad1ed5ee
JH
1087 map += used;
1088 mapsize -= used;
93821bd9
LT
1089
1090 /* Set up the stream for the rest.. */
1091 stream->next_in = map;
1092 stream->avail_in = mapsize;
c4483576 1093 inflateInit(stream);
93821bd9
LT
1094
1095 /* And generate the fake traditional header */
ad1ed5ee 1096 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1097 typename(type), size);
93821bd9 1098 return 0;
c4483576
LT
1099}
1100
7efbff75 1101static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1102{
1103 int bytes = strlen(buffer) + 1;
d565b341 1104 unsigned char *buf = xmalloc(1+size);
93821bd9 1105 unsigned long n;
7efbff75 1106 int status = Z_OK;
5180cacc 1107
93821bd9
LT
1108 n = stream->total_out - bytes;
1109 if (n > size)
1110 n = size;
1111 memcpy(buf, (char *) buffer + bytes, n);
1112 bytes = n;
456cdf6e
LT
1113 if (bytes <= size) {
1114 /*
1115 * The above condition must be (bytes <= size), not
1116 * (bytes < size). In other words, even though we
1117 * expect no more output and set avail_out to zer0,
1118 * the input zlib stream may have bytes that express
1119 * "this concludes the stream", and we *do* want to
1120 * eat that input.
1121 *
1122 * Otherwise we would not be able to test that we
1123 * consumed all the input to reach the expected size;
1124 * we also want to check that zlib tells us that all
1125 * went well with status == Z_STREAM_END at the end.
1126 */
5180cacc
LT
1127 stream->next_out = buf + bytes;
1128 stream->avail_out = size - bytes;
7efbff75
JH
1129 while (status == Z_OK)
1130 status = inflate(stream, Z_FINISH);
5180cacc
LT
1131 }
1132 buf[size] = 0;
456cdf6e 1133 if (status == Z_STREAM_END && !stream->avail_in) {
7efbff75
JH
1134 inflateEnd(stream);
1135 return buf;
1136 }
1137
1138 if (status < 0)
1139 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1140 else if (stream->avail_in)
1141 error("garbage at end of loose object '%s'",
1142 sha1_to_hex(sha1));
1143 free(buf);
1144 return NULL;
5180cacc
LT
1145}
1146
1147/*
1148 * We used to just use "sscanf()", but that's actually way
1149 * too permissive for what we want to check. So do an anal
1150 * object header parse by hand.
1151 */
21666f1a 1152static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1153{
21666f1a 1154 char type[10];
5180cacc
LT
1155 int i;
1156 unsigned long size;
1157
1158 /*
a6080a0a 1159 * The type can be at most ten bytes (including the
5180cacc 1160 * terminating '\0' that we add), and is followed by
21666f1a 1161 * a space.
5180cacc 1162 */
21666f1a 1163 i = 0;
5180cacc
LT
1164 for (;;) {
1165 char c = *hdr++;
1166 if (c == ' ')
1167 break;
21666f1a
NP
1168 type[i++] = c;
1169 if (i >= sizeof(type))
5180cacc 1170 return -1;
5180cacc 1171 }
21666f1a 1172 type[i] = 0;
5180cacc
LT
1173
1174 /*
1175 * The length must follow immediately, and be in canonical
1176 * decimal format (ie "010" is not valid).
1177 */
1178 size = *hdr++ - '0';
1179 if (size > 9)
1180 return -1;
1181 if (size) {
1182 for (;;) {
1183 unsigned long c = *hdr - '0';
1184 if (c > 9)
1185 break;
1186 hdr++;
1187 size = size * 10 + c;
1188 }
1189 }
1190 *sizep = size;
1191
1192 /*
1193 * The length must be followed by a zero byte
1194 */
21666f1a 1195 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1196}
1197
7efbff75 1198static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1199{
5180cacc 1200 int ret;
0fcfd160 1201 z_stream stream;
5180cacc 1202 char hdr[8192];
0fcfd160 1203
5180cacc 1204 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1205 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1206 return NULL;
1207
7efbff75 1208 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1209}
1210
54dab52a
NP
1211unsigned long get_size_from_delta(struct packed_git *p,
1212 struct pack_window **w_curs,
1213 off_t curpos)
1214{
1215 const unsigned char *data;
1216 unsigned char delta_head[20], *in;
1217 z_stream stream;
1218 int st;
1219
1220 memset(&stream, 0, sizeof(stream));
1221 stream.next_out = delta_head;
1222 stream.avail_out = sizeof(delta_head);
1223
1224 inflateInit(&stream);
1225 do {
1226 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1227 stream.next_in = in;
1228 st = inflate(&stream, Z_FINISH);
1229 curpos += stream.next_in - in;
1230 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1231 stream.total_out < sizeof(delta_head));
1232 inflateEnd(&stream);
1233 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head))
1234 die("delta data unpack-initial failed");
1235
1236 /* Examine the initial part of the delta to figure out
1237 * the result size.
1238 */
1239 data = delta_head;
1240
1241 /* ignore base size */
1242 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1243
1244 /* Read the result size */
1245 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1246}
1247
c4001d92 1248static off_t get_delta_base(struct packed_git *p,
03e79c88 1249 struct pack_window **w_curs,
c4001d92 1250 off_t *curpos,
21666f1a 1251 enum object_type type,
c4001d92 1252 off_t delta_obj_offset)
eb32d236 1253{
2b87c45b 1254 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1255 off_t base_offset;
eb32d236 1256
8d8a4ea5
SP
1257 /* use_pack() assured us we have [base_info, base_info + 20)
1258 * as a range that we can look at without walking off the
1259 * end of the mapped window. Its actually the hash size
1260 * that is assured. An OFS_DELTA longer than the hash size
1261 * is stupid, as then a REF_DELTA would be smaller to store.
1262 */
21666f1a 1263 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1264 unsigned used = 0;
1265 unsigned char c = base_info[used++];
1266 base_offset = c & 127;
1267 while (c & 128) {
1268 base_offset += 1;
8723f216 1269 if (!base_offset || MSB(base_offset, 7))
eb32d236
NP
1270 die("offset value overflow for delta base object");
1271 c = base_info[used++];
1272 base_offset = (base_offset << 7) + (c & 127);
1273 }
1274 base_offset = delta_obj_offset - base_offset;
1275 if (base_offset >= delta_obj_offset)
1276 die("delta base offset out of bound");
2b87c45b 1277 *curpos += used;
21666f1a 1278 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1279 /* The base entry _must_ be in the same pack */
1280 base_offset = find_pack_entry_one(base_info, p);
1281 if (!base_offset)
1282 die("failed to find delta-pack base object %s",
1283 sha1_to_hex(base_info));
2b87c45b 1284 *curpos += 20;
eb32d236
NP
1285 } else
1286 die("I am totally screwed");
2b87c45b 1287 return base_offset;
eb32d236
NP
1288}
1289
f3bf9224 1290/* forward declaration for a mutually recursive function */
c4001d92 1291static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1292 unsigned long *sizep);
f3bf9224 1293
43057304 1294static int packed_delta_info(struct packed_git *p,
03e79c88 1295 struct pack_window **w_curs,
c4001d92 1296 off_t curpos,
21666f1a 1297 enum object_type type,
c4001d92 1298 off_t obj_offset,
43057304 1299 unsigned long *sizep)
5db47c2b 1300{
c4001d92 1301 off_t base_offset;
f3bf9224 1302
21666f1a
NP
1303 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
1304 type = packed_object_info(p, base_offset, NULL);
f3bf9224 1305
c62266f3
JH
1306 /* We choose to only get the type of the base object and
1307 * ignore potentially corrupt pack file that expects the delta
1308 * based on a base with a wrong size. This saves tons of
1309 * inflate() calls.
1310 */
54dab52a
NP
1311 if (sizep)
1312 *sizep = get_size_from_delta(p, w_curs, curpos);
21666f1a
NP
1313
1314 return type;
5db47c2b
JH
1315}
1316
2b87c45b
NP
1317static int unpack_object_header(struct packed_git *p,
1318 struct pack_window **w_curs,
c4001d92 1319 off_t *curpos,
2b87c45b 1320 unsigned long *sizep)
a733cb60 1321{
03e79c88
SP
1322 unsigned char *base;
1323 unsigned int left;
ad1ed5ee 1324 unsigned long used;
2b87c45b 1325 enum object_type type;
a733cb60 1326
8d8a4ea5
SP
1327 /* use_pack() assures us we have [base, base + 20) available
1328 * as a range that we can look at at. (Its actually the hash
3dff5379 1329 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1330 * the maximum deflated object size is 2^137, which is just
1331 * insane, so we know won't exceed what we have been given.
1332 */
2b87c45b
NP
1333 base = use_pack(p, w_curs, *curpos, &left);
1334 used = unpack_object_header_gently(base, left, &type, sizep);
ad1ed5ee
JH
1335 if (!used)
1336 die("object offset outside of pack file");
2b87c45b 1337 *curpos += used;
ad1ed5ee 1338
2b87c45b 1339 return type;
a733cb60
LT
1340}
1341
21666f1a 1342const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1343 off_t obj_offset,
21666f1a
NP
1344 unsigned long *size,
1345 unsigned long *store_size,
1346 unsigned int *delta_chain_length,
1347 unsigned char *base_sha1)
ad8c80a5 1348{
03e79c88 1349 struct pack_window *w_curs = NULL;
c4001d92
SP
1350 off_t curpos;
1351 unsigned long dummy;
43057304 1352 unsigned char *next_sha1;
21666f1a 1353 enum object_type type;
ad8c80a5 1354
43057304 1355 *delta_chain_length = 0;
2b87c45b 1356 curpos = obj_offset;
21666f1a 1357 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304
NP
1358
1359 for (;;) {
21666f1a 1360 switch (type) {
43057304 1361 default:
08a19d87 1362 die("pack %s contains unknown object type %d",
21666f1a 1363 p->pack_name, type);
43057304
NP
1364 case OBJ_COMMIT:
1365 case OBJ_TREE:
1366 case OBJ_BLOB:
1367 case OBJ_TAG:
43057304 1368 *store_size = 0; /* notyet */
03e79c88 1369 unuse_pack(&w_curs);
21666f1a 1370 return typename(type);
eb32d236 1371 case OBJ_OFS_DELTA:
21666f1a 1372 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
eb32d236 1373 if (*delta_chain_length == 0) {
2b87c45b 1374 /* TODO: find base_sha1 as pointed by curpos */
30fee062 1375 hashclr(base_sha1);
eb32d236
NP
1376 }
1377 break;
1378 case OBJ_REF_DELTA:
2b87c45b 1379 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1380 if (*delta_chain_length == 0)
1381 hashcpy(base_sha1, next_sha1);
2b87c45b 1382 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1383 break;
1384 }
43057304 1385 (*delta_chain_length)++;
2b87c45b 1386 curpos = obj_offset;
21666f1a 1387 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1388 }
ad8c80a5
JH
1389}
1390
c4001d92 1391static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1392 unsigned long *sizep)
1f688557 1393{
03e79c88 1394 struct pack_window *w_curs = NULL;
c4001d92
SP
1395 unsigned long size;
1396 off_t curpos = obj_offset;
21666f1a 1397 enum object_type type;
5db47c2b 1398
21666f1a 1399 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1400
21666f1a 1401 switch (type) {
eb32d236
NP
1402 case OBJ_OFS_DELTA:
1403 case OBJ_REF_DELTA:
21666f1a
NP
1404 type = packed_delta_info(p, &w_curs, curpos,
1405 type, obj_offset, sizep);
2b87c45b 1406 break;
a733cb60 1407 case OBJ_COMMIT:
a733cb60 1408 case OBJ_TREE:
a733cb60 1409 case OBJ_BLOB:
a733cb60 1410 case OBJ_TAG:
2b87c45b
NP
1411 if (sizep)
1412 *sizep = size;
a69d0943 1413 break;
1f688557 1414 default:
08a19d87 1415 die("pack %s contains unknown object type %d",
21666f1a 1416 p->pack_name, type);
1f688557 1417 }
2b87c45b 1418 unuse_pack(&w_curs);
21666f1a 1419 return type;
1f688557
JH
1420}
1421
eb950c19 1422static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1423 struct pack_window **w_curs,
c4001d92 1424 off_t curpos,
eb950c19 1425 unsigned long size)
de530aaa
SP
1426{
1427 int st;
1428 z_stream stream;
079afb18 1429 unsigned char *buffer, *in;
de530aaa
SP
1430
1431 buffer = xmalloc(size + 1);
1432 buffer[size] = 0;
1433 memset(&stream, 0, sizeof(stream));
de530aaa
SP
1434 stream.next_out = buffer;
1435 stream.avail_out = size;
1436
1437 inflateInit(&stream);
079afb18 1438 do {
2b87c45b 1439 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18
SP
1440 stream.next_in = in;
1441 st = inflate(&stream, Z_FINISH);
2b87c45b 1442 curpos += stream.next_in - in;
079afb18 1443 } while (st == Z_OK || st == Z_BUF_ERROR);
de530aaa
SP
1444 inflateEnd(&stream);
1445 if ((st != Z_STREAM_END) || stream.total_out != size) {
1446 free(buffer);
1447 return NULL;
1448 }
1449
1450 return buffer;
1451}
1452
e5e01619
LT
1453#define MAX_DELTA_CACHE (256)
1454
18bdec11 1455static size_t delta_base_cached;
5e08ecbf
NP
1456
1457static struct delta_base_cache_lru_list {
1458 struct delta_base_cache_lru_list *prev;
1459 struct delta_base_cache_lru_list *next;
1460} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1461
e5e01619 1462static struct delta_base_cache_entry {
5e08ecbf
NP
1463 struct delta_base_cache_lru_list lru;
1464 void *data;
e5e01619
LT
1465 struct packed_git *p;
1466 off_t base_offset;
1467 unsigned long size;
e5e01619
LT
1468 enum object_type type;
1469} delta_base_cache[MAX_DELTA_CACHE];
1470
1471static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1472{
1473 unsigned long hash;
1474
1475 hash = (unsigned long)p + (unsigned long)base_offset;
1476 hash += (hash >> 8) + (hash >> 16);
3358004a 1477 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1478}
1479
62f255ad 1480static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1481 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1482{
e5e01619
LT
1483 void *ret;
1484 unsigned long hash = pack_entry_hash(p, base_offset);
1485 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1486
1487 ret = ent->data;
1488 if (ret && ent->p == p && ent->base_offset == base_offset)
1489 goto found_cache_entry;
62f255ad 1490 return unpack_entry(p, base_offset, type, base_size);
e5e01619
LT
1491
1492found_cache_entry:
18bdec11 1493 if (!keep_cache) {
a0cba108 1494 ent->data = NULL;
5e08ecbf
NP
1495 ent->lru.next->prev = ent->lru.prev;
1496 ent->lru.prev->next = ent->lru.next;
18bdec11 1497 delta_base_cached -= ent->size;
182af834
PH
1498 } else {
1499 ret = xmemdupz(ent->data, ent->size);
a0cba108 1500 }
e5e01619
LT
1501 *type = ent->type;
1502 *base_size = ent->size;
1503 return ret;
62f255ad
LT
1504}
1505
18bdec11
SP
1506static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1507{
1508 if (ent->data) {
1509 free(ent->data);
1510 ent->data = NULL;
5e08ecbf
NP
1511 ent->lru.next->prev = ent->lru.prev;
1512 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1513 delta_base_cached -= ent->size;
1514 }
1515}
1516
62f255ad
LT
1517static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1518 void *base, unsigned long base_size, enum object_type type)
1519{
5e08ecbf 1520 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1521 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1522 struct delta_base_cache_lru_list *lru;
e5e01619 1523
18bdec11
SP
1524 release_delta_base_cache(ent);
1525 delta_base_cached += base_size;
5e08ecbf
NP
1526
1527 for (lru = delta_base_cache_lru.next;
1528 delta_base_cached > delta_base_cache_limit
1529 && lru != &delta_base_cache_lru;
1530 lru = lru->next) {
1531 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1532 if (f->type == OBJ_BLOB)
1533 release_delta_base_cache(f);
1534 }
5e08ecbf
NP
1535 for (lru = delta_base_cache_lru.next;
1536 delta_base_cached > delta_base_cache_limit
1537 && lru != &delta_base_cache_lru;
1538 lru = lru->next) {
1539 struct delta_base_cache_entry *f = (void *)lru;
1540 release_delta_base_cache(f);
1541 }
18bdec11 1542
e5e01619
LT
1543 ent->p = p;
1544 ent->base_offset = base_offset;
1545 ent->type = type;
1546 ent->data = base;
1547 ent->size = base_size;
5e08ecbf
NP
1548 ent->lru.next = &delta_base_cache_lru;
1549 ent->lru.prev = delta_base_cache_lru.prev;
1550 delta_base_cache_lru.prev->next = &ent->lru;
1551 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1552}
1553
eb950c19 1554static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1555 struct pack_window **w_curs,
c4001d92 1556 off_t curpos,
1f688557 1557 unsigned long delta_size,
c4001d92 1558 off_t obj_offset,
21666f1a 1559 enum object_type *type,
eb950c19 1560 unsigned long *sizep)
1f688557 1561{
7c3e8be3 1562 void *delta_data, *result, *base;
c4001d92
SP
1563 unsigned long base_size;
1564 off_t base_offset;
43057304 1565
21666f1a 1566 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
a0cba108 1567 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
67686d95 1568 if (!base)
c4001d92
SP
1569 die("failed to read delta base object"
1570 " at %"PRIuMAX" from %s",
1571 (uintmax_t)base_offset, p->pack_name);
67686d95 1572
2b87c45b 1573 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
9064d87b
SP
1574 if (!delta_data)
1575 die("failed to unpack compressed delta"
1576 " at %"PRIuMAX" from %s",
1577 (uintmax_t)curpos, p->pack_name);
1f688557
JH
1578 result = patch_delta(base, base_size,
1579 delta_data, delta_size,
21666f1a 1580 sizep);
1f688557
JH
1581 if (!result)
1582 die("failed to apply delta");
1583 free(delta_data);
62f255ad 1584 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1585 return result;
1586}
1587
c4001d92 1588void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1589 enum object_type *type, unsigned long *sizep)
1f688557 1590{
03e79c88 1591 struct pack_window *w_curs = NULL;
c4001d92 1592 off_t curpos = obj_offset;
21666f1a 1593 void *data;
1f688557 1594
21666f1a
NP
1595 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1596 switch (*type) {
eb32d236
NP
1597 case OBJ_OFS_DELTA:
1598 case OBJ_REF_DELTA:
21666f1a
NP
1599 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1600 obj_offset, type, sizep);
4d703a1a 1601 break;
a733cb60 1602 case OBJ_COMMIT:
a733cb60 1603 case OBJ_TREE:
a733cb60 1604 case OBJ_BLOB:
a733cb60 1605 case OBJ_TAG:
21666f1a 1606 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1607 break;
1f688557 1608 default:
21666f1a 1609 die("unknown object type %i in %s", *type, p->pack_name);
1f688557 1610 }
03e79c88 1611 unuse_pack(&w_curs);
21666f1a 1612 return data;
1f688557
JH
1613}
1614
d079837e 1615const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1616 uint32_t n)
9a217f2a 1617{
42873078 1618 const unsigned char *index = p->index_data;
d079837e
SP
1619 if (!index) {
1620 if (open_pack_index(p))
1621 return NULL;
1622 index = p->index_data;
1623 }
57059091 1624 if (n >= p->num_objects)
d72308e0 1625 return NULL;
74e34e1f
NP
1626 index += 4 * 256;
1627 if (p->index_version == 1) {
1628 return index + 24 * n + 4;
1629 } else {
1630 index += 8;
1631 return index + 20 * n;
1632 }
1633}
1634
1635static off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
1636{
1637 const unsigned char *index = p->index_data;
1638 index += 4 * 256;
1639 if (p->index_version == 1) {
1640 return ntohl(*((uint32_t *)(index + 24 * n)));
1641 } else {
1642 uint32_t off;
1643 index += 8 + p->num_objects * (20 + 4);
1644 off = ntohl(*((uint32_t *)(index + 4 * n)));
1645 if (!(off & 0x80000000))
1646 return off;
1647 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1648 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1649 ntohl(*((uint32_t *)(index + 4)));
1650 }
9a217f2a
JH
1651}
1652
c4001d92 1653off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1654 struct packed_git *p)
1f688557 1655{
42873078 1656 const uint32_t *level1_ofs = p->index_data;
42873078 1657 const unsigned char *index = p->index_data;
74e34e1f 1658 unsigned hi, lo;
42873078 1659
d079837e
SP
1660 if (!index) {
1661 if (open_pack_index(p))
1662 return 0;
1663 level1_ofs = p->index_data;
1664 index = p->index_data;
1665 }
74e34e1f
NP
1666 if (p->index_version > 1) {
1667 level1_ofs += 2;
1668 index += 8;
1669 }
42873078 1670 index += 4 * 256;
74e34e1f
NP
1671 hi = ntohl(level1_ofs[*sha1]);
1672 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
1f688557
JH
1673
1674 do {
74e34e1f
NP
1675 unsigned mi = (lo + hi) / 2;
1676 unsigned x = (p->index_version > 1) ? (mi * 20) : (mi * 24 + 4);
1677 int cmp = hashcmp(index + x, sha1);
43057304 1678 if (!cmp)
74e34e1f 1679 return nth_packed_object_offset(p, mi);
1f688557
JH
1680 if (cmp > 0)
1681 hi = mi;
1682 else
1683 lo = mi+1;
1684 } while (lo < hi);
1685 return 0;
1686}
1687
000dfd3f 1688int matches_pack_name(struct packed_git *p, const char *name)
d4ff6d92
SP
1689{
1690 const char *last_c, *c;
1691
000dfd3f
JH
1692 if (!strcmp(p->pack_name, name))
1693 return 1;
d4ff6d92
SP
1694
1695 for (c = p->pack_name, last_c = c; *c;)
1696 if (*c == '/')
1697 last_c = ++c;
1698 else
1699 ++c;
000dfd3f
JH
1700 if (!strcmp(last_c, name))
1701 return 1;
d4ff6d92 1702
000dfd3f 1703 return 0;
d4ff6d92
SP
1704}
1705
106d710b 1706static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
1f688557 1707{
f7c22cc6 1708 static struct packed_git *last_found = (void *)1;
1f688557 1709 struct packed_git *p;
c4001d92 1710 off_t offset;
43057304 1711
1f688557 1712 prepare_packed_git();
f7c22cc6
NP
1713 if (!packed_git)
1714 return 0;
1715 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1716
f7c22cc6 1717 do {
106d710b
JH
1718 if (ignore_packed) {
1719 const char **ig;
1720 for (ig = ignore_packed; *ig; ig++)
000dfd3f 1721 if (matches_pack_name(p, *ig))
106d710b
JH
1722 break;
1723 if (*ig)
f7c22cc6 1724 goto next;
106d710b 1725 }
f7c22cc6 1726
43057304
NP
1727 offset = find_pack_entry_one(sha1, p);
1728 if (offset) {
c715f783
SP
1729 /*
1730 * We are about to tell the caller where they can
1731 * locate the requested object. We better make
1732 * sure the packfile is still here and can be
1733 * accessed before supplying that answer, as
1734 * it may have been deleted since the index
1735 * was loaded!
1736 */
1737 if (p->pack_fd == -1 && open_packed_git(p)) {
1738 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1739 goto next;
c715f783 1740 }
43057304
NP
1741 e->offset = offset;
1742 e->p = p;
1743 hashcpy(e->sha1, sha1);
f7c22cc6 1744 last_found = p;
1f688557 1745 return 1;
43057304 1746 }
f7c22cc6
NP
1747
1748 next:
1749 if (p == last_found)
1750 p = packed_git;
1751 else
1752 p = p->next;
1753 if (p == last_found)
1754 p = p->next;
1755 } while (p);
1f688557
JH
1756 return 0;
1757}
1758
a6080a0a 1759struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1760 struct packed_git *packs)
1761{
1762 struct packed_git *p;
bf592c50
DB
1763
1764 for (p = packs; p; p = p->next) {
43057304 1765 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1766 return p;
1767 }
1768 return NULL;
21666f1a 1769
bf592c50
DB
1770}
1771
21666f1a 1772static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1773{
36e4d74a 1774 int status;
65c2e0c3
JH
1775 unsigned long mapsize, size;
1776 void *map;
1777 z_stream stream;
d65a16f6 1778 char hdr[32];
65c2e0c3 1779
bb6b8e4f 1780 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1781 if (!map)
1782 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1783 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1784 status = error("unable to unpack %s header",
1785 sha1_to_hex(sha1));
21666f1a 1786 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1787 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1788 else if (sizep)
1789 *sizep = size;
65c2e0c3
JH
1790 inflateEnd(&stream);
1791 munmap(map, mapsize);
1792 return status;
1793}
1794
21666f1a 1795int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1796{
f0df4ed5
JS
1797 struct pack_entry e;
1798
1799 if (!find_pack_entry(sha1, &e, NULL)) {
1800 reprepare_packed_git();
1801 if (!find_pack_entry(sha1, &e, NULL))
21666f1a 1802 return sha1_loose_object_info(sha1, sizep);
f0df4ed5 1803 }
21666f1a 1804 return packed_object_info(e.p, e.offset, sizep);
f0df4ed5
JS
1805}
1806
21666f1a
NP
1807static void *read_packed_sha1(const unsigned char *sha1,
1808 enum object_type *type, unsigned long *size)
1f688557
JH
1809{
1810 struct pack_entry e;
1811
8276c007 1812 if (!find_pack_entry(sha1, &e, NULL))
1f688557 1813 return NULL;
8276c007 1814 else
a0cba108 1815 return cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1f688557
JH
1816}
1817
d66b37bb
JH
1818/*
1819 * This is meant to hold a *small* number of objects that you would
1820 * want read_sha1_file() to be able to return, but yet you do not want
1821 * to write them into the object store (e.g. a browse-only
1822 * application).
1823 */
1824static struct cached_object {
1825 unsigned char sha1[20];
21666f1a 1826 enum object_type type;
d66b37bb
JH
1827 void *buf;
1828 unsigned long size;
1829} *cached_objects;
1830static int cached_object_nr, cached_object_alloc;
1831
1832static struct cached_object *find_cached_object(const unsigned char *sha1)
1833{
1834 int i;
1835 struct cached_object *co = cached_objects;
1836
1837 for (i = 0; i < cached_object_nr; i++, co++) {
1838 if (!hashcmp(co->sha1, sha1))
1839 return co;
1840 }
1841 return NULL;
1842}
1843
21666f1a
NP
1844int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
1845 unsigned char *sha1)
d66b37bb
JH
1846{
1847 struct cached_object *co;
1848
21666f1a 1849 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
1850 if (has_sha1_file(sha1) || find_cached_object(sha1))
1851 return 0;
1852 if (cached_object_alloc <= cached_object_nr) {
1853 cached_object_alloc = alloc_nr(cached_object_alloc);
1854 cached_objects = xrealloc(cached_objects,
1855 sizeof(*cached_objects) *
1856 cached_object_alloc);
1857 }
1858 co = &cached_objects[cached_object_nr++];
1859 co->size = len;
21666f1a 1860 co->type = type;
efa13f7b
JH
1861 co->buf = xmalloc(len);
1862 memcpy(co->buf, buf, len);
d66b37bb
JH
1863 hashcpy(co->sha1, sha1);
1864 return 0;
1865}
1866
21666f1a
NP
1867void *read_sha1_file(const unsigned char *sha1, enum object_type *type,
1868 unsigned long *size)
0fcfd160
LT
1869{
1870 unsigned long mapsize;
1871 void *map, *buf;
d66b37bb
JH
1872 struct cached_object *co;
1873
1874 co = find_cached_object(sha1);
1875 if (co) {
21666f1a 1876 *type = co->type;
d66b37bb 1877 *size = co->size;
182af834 1878 return xmemdupz(co->buf, co->size);
d66b37bb 1879 }
0fcfd160 1880
8276c007
PE
1881 buf = read_packed_sha1(sha1, type, size);
1882 if (buf)
1883 return buf;
bb6b8e4f 1884 map = map_sha1_file(sha1, &mapsize);
0fcfd160 1885 if (map) {
7efbff75 1886 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
1887 munmap(map, mapsize);
1888 return buf;
1889 }
637cdd9d 1890 reprepare_packed_git();
8276c007 1891 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
1892}
1893
40469ee9 1894void *read_object_with_reference(const unsigned char *sha1,
21666f1a 1895 const char *required_type_name,
40469ee9
JH
1896 unsigned long *size,
1897 unsigned char *actual_sha1_return)
f4913f91 1898{
21666f1a 1899 enum object_type type, required_type;
f4913f91
JH
1900 void *buffer;
1901 unsigned long isize;
40469ee9 1902 unsigned char actual_sha1[20];
f4913f91 1903
21666f1a 1904 required_type = type_from_string(required_type_name);
e702496e 1905 hashcpy(actual_sha1, sha1);
40469ee9
JH
1906 while (1) {
1907 int ref_length = -1;
1908 const char *ref_type = NULL;
f4913f91 1909
21666f1a 1910 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
1911 if (!buffer)
1912 return NULL;
21666f1a 1913 if (type == required_type) {
40469ee9
JH
1914 *size = isize;
1915 if (actual_sha1_return)
e702496e 1916 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
1917 return buffer;
1918 }
1919 /* Handle references */
21666f1a 1920 else if (type == OBJ_COMMIT)
40469ee9 1921 ref_type = "tree ";
21666f1a 1922 else if (type == OBJ_TAG)
40469ee9
JH
1923 ref_type = "object ";
1924 else {
1925 free(buffer);
1926 return NULL;
1927 }
1928 ref_length = strlen(ref_type);
f4913f91 1929
40469ee9 1930 if (memcmp(buffer, ref_type, ref_length) ||
1d7f171c 1931 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
1932 free(buffer);
1933 return NULL;
1934 }
1cf58e72 1935 free(buffer);
40469ee9
JH
1936 /* Now we have the ID of the referred-to object in
1937 * actual_sha1. Check again. */
f4913f91 1938 }
f4913f91
JH
1939}
1940
ce9fbf16 1941static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 1942 const char *type, unsigned char *sha1,
d65a16f6 1943 char *hdr, int *hdrlen)
d410c0f5
JH
1944{
1945 SHA_CTX c;
1946
1947 /* Generate the header */
d65a16f6 1948 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
1949
1950 /* Sha1.. */
1951 SHA1_Init(&c);
1952 SHA1_Update(&c, hdr, *hdrlen);
1953 SHA1_Update(&c, buf, len);
1954 SHA1_Final(sha1, &c);
d410c0f5
JH
1955}
1956
230f1322
LT
1957/*
1958 * Link the tempfile to the final place, possibly creating the
1959 * last directory level as you do so.
1960 *
1961 * Returns the errno on failure, 0 on success.
1962 */
839837b9 1963static int link_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1964{
1965 int ret;
756aaf4a 1966 char *dir;
230f1322
LT
1967
1968 if (!link(tmpfile, filename))
1969 return 0;
1970
1971 /*
756aaf4a 1972 * Try to mkdir the last path component if that failed.
230f1322
LT
1973 *
1974 * Re-try the "link()" regardless of whether the mkdir
1975 * succeeds, since a race might mean that somebody
1976 * else succeeded.
1977 */
1978 ret = errno;
756aaf4a
SP
1979 dir = strrchr(filename, '/');
1980 if (dir) {
1981 *dir = 0;
866cae0d 1982 if (!mkdir(filename, 0777) && adjust_shared_perm(filename)) {
91c23e48 1983 *dir = '/';
756aaf4a 1984 return -2;
91c23e48 1985 }
756aaf4a
SP
1986 *dir = '/';
1987 if (!link(tmpfile, filename))
1988 return 0;
1989 ret = errno;
230f1322
LT
1990 }
1991 return ret;
1992}
1993
1994/*
1995 * Move the just written object into its final resting place
1996 */
839837b9 1997int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322
LT
1998{
1999 int ret = link_temp_to_file(tmpfile, filename);
7ebb6fca
LT
2000
2001 /*
2002 * Coda hack - coda doesn't like cross-directory links,
2003 * so we fall back to a rename, which will mean that it
2004 * won't be able to check collisions, but that's not a
2005 * big deal.
2006 *
2007 * The same holds for FAT formatted media.
2008 *
2009 * When this succeeds, we just return 0. We have nothing
2010 * left to unlink.
2011 */
2012 if (ret && ret != EEXIST) {
2013 if (!rename(tmpfile, filename))
230f1322 2014 return 0;
9e48b389 2015 ret = errno;
230f1322
LT
2016 }
2017 unlink(tmpfile);
2018 if (ret) {
2019 if (ret != EEXIST) {
916d081b 2020 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2021 }
2022 /* FIXME!!! Collision check here ? */
2023 }
2024
2025 return 0;
2026}
2027
4d548150
LT
2028static int write_buffer(int fd, const void *buf, size_t len)
2029{
d34cf19b 2030 if (write_in_full(fd, buf, len) < 0)
93822c22 2031 return error("file write error (%s)", strerror(errno));
4d548150
LT
2032 return 0;
2033}
2034
ce9fbf16 2035int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2036 unsigned char *sha1)
2037{
d65a16f6 2038 char hdr[32];
abdc3fc8
RS
2039 int hdrlen;
2040 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2041 return 0;
2042}
2043
bf0f910d 2044int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
0fcfd160 2045{
ac54c277 2046 int size, ret;
bf0f910d 2047 unsigned char *compressed;
0fcfd160
LT
2048 z_stream stream;
2049 unsigned char sha1[20];
706bc531 2050 char *filename;
aac17941 2051 static char tmpfile[PATH_MAX];
d65a16f6 2052 char hdr[32];
230f1322 2053 int fd, hdrlen;
a44c9a5e 2054
d410c0f5
JH
2055 /* Normally if we have it in the pack then we do not bother writing
2056 * it out into .git/objects/??/?{38} file.
2057 */
972a9155
RS
2058 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2059 filename = sha1_file_name(sha1);
706bc531 2060 if (returnsha1)
e702496e 2061 hashcpy(returnsha1, sha1);
d410c0f5
JH
2062 if (has_sha1_file(sha1))
2063 return 0;
aac17941
LT
2064 fd = open(filename, O_RDONLY);
2065 if (fd >= 0) {
706bc531 2066 /*
aac17941
LT
2067 * FIXME!!! We might do collision checking here, but we'd
2068 * need to uncompress the old file and check it. Later.
706bc531 2069 */
aac17941 2070 close(fd);
706bc531
LT
2071 return 0;
2072 }
2073
aac17941 2074 if (errno != ENOENT) {
916d081b 2075 return error("sha1 file %s: %s\n", filename, strerror(errno));
aac17941
LT
2076 }
2077
0e55181f 2078 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
ace1534d 2079
aac17941
LT
2080 fd = mkstemp(tmpfile);
2081 if (fd < 0) {
916d081b
PB
2082 if (errno == EPERM)
2083 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2084 else
2085 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2086 }
2087
0fcfd160
LT
2088 /* Set it up */
2089 memset(&stream, 0, sizeof(stream));
12f6c308 2090 deflateInit(&stream, zlib_compression_level);
93821bd9 2091 size = 8 + deflateBound(&stream, len+hdrlen);
812666c8 2092 compressed = xmalloc(size);
0fcfd160
LT
2093
2094 /* Compress it */
0fcfd160
LT
2095 stream.next_out = compressed;
2096 stream.avail_out = size;
a44c9a5e
LT
2097
2098 /* First header.. */
d65a16f6 2099 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2100 stream.avail_in = hdrlen;
726f852b
NP
2101 while (deflate(&stream, 0) == Z_OK)
2102 /* nothing */;
a44c9a5e
LT
2103
2104 /* Then the data itself.. */
2105 stream.next_in = buf;
2106 stream.avail_in = len;
ac54c277
LT
2107 ret = deflate(&stream, Z_FINISH);
2108 if (ret != Z_STREAM_END)
2109 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
2110
2111 ret = deflateEnd(&stream);
2112 if (ret != Z_OK)
2113 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
2114
0fcfd160
LT
2115 size = stream.total_out;
2116
4d548150
LT
2117 if (write_buffer(fd, compressed, size) < 0)
2118 die("unable to write sha1 file");
aac17941 2119 fchmod(fd, 0444);
e82973cf
JH
2120 if (close(fd))
2121 die("unable to write sha1 file");
383f85b7 2122 free(compressed);
0fcfd160 2123
230f1322 2124 return move_temp_to_file(tmpfile, filename);
0fcfd160 2125}
8237b185 2126
4d548150
LT
2127/*
2128 * We need to unpack and recompress the object for writing
2129 * it out to a different file.
2130 */
2131static void *repack_object(const unsigned char *sha1, unsigned long *objsize)
a5eda52b 2132{
4d548150 2133 size_t size;
a5eda52b 2134 z_stream stream;
4d548150
LT
2135 unsigned char *unpacked;
2136 unsigned long len;
21666f1a 2137 enum object_type type;
d65a16f6 2138 char hdr[32];
4d548150
LT
2139 int hdrlen;
2140 void *buf;
bfc66daf 2141
a9486b02 2142 /* need to unpack and recompress it by itself */
21666f1a 2143 unpacked = read_packed_sha1(sha1, &type, &len);
8276c007
PE
2144 if (!unpacked)
2145 error("cannot read sha1_file for %s", sha1_to_hex(sha1));
a5eda52b 2146
21666f1a 2147 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
a5eda52b 2148
4d548150
LT
2149 /* Set it up */
2150 memset(&stream, 0, sizeof(stream));
12f6c308 2151 deflateInit(&stream, zlib_compression_level);
4d548150
LT
2152 size = deflateBound(&stream, len + hdrlen);
2153 buf = xmalloc(size);
a5eda52b 2154
4d548150
LT
2155 /* Compress it */
2156 stream.next_out = buf;
2157 stream.avail_out = size;
a5eda52b 2158
4d548150
LT
2159 /* First header.. */
2160 stream.next_in = (void *)hdr;
2161 stream.avail_in = hdrlen;
2162 while (deflate(&stream, 0) == Z_OK)
2163 /* nothing */;
bfc66daf 2164
4d548150
LT
2165 /* Then the data itself.. */
2166 stream.next_in = unpacked;
2167 stream.avail_in = len;
2168 while (deflate(&stream, Z_FINISH) == Z_OK)
2169 /* nothing */;
2170 deflateEnd(&stream);
2171 free(unpacked);
bfc66daf 2172
4d548150
LT
2173 *objsize = stream.total_out;
2174 return buf;
2175}
2176
2177int write_sha1_to_fd(int fd, const unsigned char *sha1)
2178{
2179 int retval;
2180 unsigned long objsize;
bb6b8e4f 2181 void *buf = map_sha1_file(sha1, &objsize);
4d548150
LT
2182
2183 if (buf) {
2184 retval = write_buffer(fd, buf, objsize);
2185 munmap(buf, objsize);
2186 return retval;
2187 }
2188
2189 buf = repack_object(sha1, &objsize);
2190 retval = write_buffer(fd, buf, objsize);
2191 free(buf);
2192 return retval;
a5eda52b
DB
2193}
2194
70b9829e
DB
2195int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
2196 size_t bufsize, size_t *bufposn)
8237b185 2197{
230f1322 2198 char tmpfile[PATH_MAX];
8237b185
DB
2199 int local;
2200 z_stream stream;
2201 unsigned char real_sha1[20];
bf0f910d 2202 unsigned char discard[4096];
8237b185
DB
2203 int ret;
2204 SHA_CTX c;
2205
0e55181f 2206 snprintf(tmpfile, sizeof(tmpfile), "%s/tmp_obj_XXXXXX", get_object_directory());
8237b185 2207
230f1322 2208 local = mkstemp(tmpfile);
916d081b
PB
2209 if (local < 0) {
2210 if (errno == EPERM)
2211 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2212 else
2213 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
2214 }
8237b185
DB
2215
2216 memset(&stream, 0, sizeof(stream));
2217
2218 inflateInit(&stream);
2219
2220 SHA1_Init(&c);
2221
2222 do {
2223 ssize_t size;
70b9829e
DB
2224 if (*bufposn) {
2225 stream.avail_in = *bufposn;
96ad15ae 2226 stream.next_in = (unsigned char *) buffer;
70b9829e
DB
2227 do {
2228 stream.next_out = discard;
2229 stream.avail_out = sizeof(discard);
2230 ret = inflate(&stream, Z_SYNC_FLUSH);
2231 SHA1_Update(&c, discard, sizeof(discard) -
2232 stream.avail_out);
2233 } while (stream.avail_in && ret == Z_OK);
4d548150
LT
2234 if (write_buffer(local, buffer, *bufposn - stream.avail_in) < 0)
2235 die("unable to write sha1 file");
70b9829e
DB
2236 memmove(buffer, buffer + *bufposn - stream.avail_in,
2237 stream.avail_in);
2238 *bufposn = stream.avail_in;
2239 if (ret != Z_OK)
2240 break;
2241 }
93d26e4c 2242 size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
8237b185
DB
2243 if (size <= 0) {
2244 close(local);
230f1322 2245 unlink(tmpfile);
8237b185
DB
2246 if (!size)
2247 return error("Connection closed?");
2248 perror("Reading from connection");
2249 return -1;
2250 }
70b9829e
DB
2251 *bufposn += size;
2252 } while (1);
8237b185
DB
2253 inflateEnd(&stream);
2254
b5b8d814 2255 fchmod(local, 0444);
0d315468
JM
2256 if (close(local) != 0)
2257 die("unable to write sha1 file");
8237b185
DB
2258 SHA1_Final(real_sha1, &c);
2259 if (ret != Z_STREAM_END) {
230f1322 2260 unlink(tmpfile);
8237b185
DB
2261 return error("File %s corrupted", sha1_to_hex(sha1));
2262 }
a89fccd2 2263 if (hashcmp(sha1, real_sha1)) {
230f1322 2264 unlink(tmpfile);
bd2afde8 2265 return error("File %s has bad hash", sha1_to_hex(sha1));
8237b185 2266 }
230f1322
LT
2267
2268 return move_temp_to_file(tmpfile, sha1_file_name(sha1));
8237b185
DB
2269}
2270
bf592c50
DB
2271int has_pack_index(const unsigned char *sha1)
2272{
2273 struct stat st;
2274 if (stat(sha1_pack_index_name(sha1), &st))
2275 return 0;
2276 return 1;
2277}
2278
2279int has_pack_file(const unsigned char *sha1)
2280{
2281 struct stat st;
2282 if (stat(sha1_pack_name(sha1), &st))
2283 return 0;
2284 return 1;
2285}
2286
106d710b 2287int has_sha1_pack(const unsigned char *sha1, const char **ignore_packed)
dade09c2
LT
2288{
2289 struct pack_entry e;
106d710b 2290 return find_pack_entry(sha1, &e, ignore_packed);
dade09c2
LT
2291}
2292
8237b185
DB
2293int has_sha1_file(const unsigned char *sha1)
2294{
8237b185 2295 struct stat st;
1f688557
JH
2296 struct pack_entry e;
2297
106d710b 2298 if (find_pack_entry(sha1, &e, NULL))
1f688557 2299 return 1;
ab90ea5d 2300 return find_sha1_file(sha1, &st) ? 1 : 0;
8237b185 2301}
74400e71 2302
e7332f96
BE
2303int index_pipe(unsigned char *sha1, int fd, const char *type, int write_object)
2304{
fd17f5b5 2305 struct strbuf buf;
e7332f96 2306 int ret;
e7332f96 2307
fd17f5b5
PH
2308 strbuf_init(&buf, 0);
2309 if (strbuf_read(&buf, fd, 4096) < 0) {
2310 strbuf_release(&buf);
024510c8
DB
2311 return -1;
2312 }
e7332f96 2313
024510c8 2314 if (!type)
8e440259 2315 type = blob_type;
024510c8 2316 if (write_object)
fd17f5b5 2317 ret = write_sha1_file(buf.buf, buf.len, type, sha1);
abdc3fc8 2318 else
fd17f5b5
PH
2319 ret = hash_sha1_file(buf.buf, buf.len, type, sha1);
2320 strbuf_release(&buf);
2321
024510c8
DB
2322 return ret;
2323}
2324
edaec3fb 2325int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
53bca91a 2326 enum object_type type, const char *path)
74400e71 2327{
dc49cd76 2328 size_t size = xsize_t(st->st_size);
3a55602e 2329 void *buf = NULL;
6c510bee 2330 int ret, re_allocated = 0;
74400e71 2331
74400e71 2332 if (size)
c4712e45 2333 buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
74400e71 2334 close(fd);
74400e71 2335
7672db20 2336 if (!type)
edaec3fb 2337 type = OBJ_BLOB;
6c510bee
LT
2338
2339 /*
2340 * Convert blobs to git internal format
2341 */
d0d8e14d 2342 if ((type == OBJ_BLOB) && S_ISREG(st->st_mode)) {
5ecd293d
PH
2343 struct strbuf nbuf;
2344 strbuf_init(&nbuf, 0);
2345 if (convert_to_git(path, buf, size, &nbuf)) {
ac78e548 2346 munmap(buf, size);
b315c5c0 2347 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2348 re_allocated = 1;
2349 }
2350 }
2351
7672db20 2352 if (write_object)
edaec3fb 2353 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2354 else
edaec3fb 2355 ret = hash_sha1_file(buf, size, typename(type), sha1);
6c510bee
LT
2356 if (re_allocated) {
2357 free(buf);
2358 return ret;
2359 }
aac17941
LT
2360 if (size)
2361 munmap(buf, size);
2362 return ret;
74400e71 2363}
ec1fcc16
JH
2364
2365int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2366{
2367 int fd;
2368 char *target;
dc49cd76 2369 size_t len;
ec1fcc16
JH
2370
2371 switch (st->st_mode & S_IFMT) {
2372 case S_IFREG:
2373 fd = open(path, O_RDONLY);
2374 if (fd < 0)
2375 return error("open(\"%s\"): %s", path,
2376 strerror(errno));
53bca91a 2377 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2378 return error("%s: failed to insert into database",
2379 path);
2380 break;
2381 case S_IFLNK:
dc49cd76
SP
2382 len = xsize_t(st->st_size);
2383 target = xmalloc(len + 1);
2384 if (readlink(path, target, len + 1) != st->st_size) {
ec1fcc16
JH
2385 char *errstr = strerror(errno);
2386 free(target);
2387 return error("readlink(\"%s\"): %s", path,
2388 errstr);
2389 }
abdc3fc8 2390 if (!write_object)
dc49cd76
SP
2391 hash_sha1_file(target, len, blob_type, sha1);
2392 else if (write_sha1_file(target, len, blob_type, sha1))
ec1fcc16
JH
2393 return error("%s: failed to insert into database",
2394 path);
2395 free(target);
2396 break;
f35a6d3b
LT
2397 case S_IFDIR:
2398 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2399 default:
2400 return error("%s: unsupported file type", path);
2401 }
2402 return 0;
2403}
a69e5429
JH
2404
2405int read_pack_header(int fd, struct pack_header *header)
2406{
2407 char *c = (char*)header;
2408 ssize_t remaining = sizeof(struct pack_header);
2409 do {
2410 ssize_t r = xread(fd, c, remaining);
2411 if (r <= 0)
2412 /* "eof before pack header was fully read" */
2413 return PH_ERROR_EOF;
2414 remaining -= r;
2415 c += r;
2416 } while (remaining > 0);
2417 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2418 /* "protocol error (pack signature mismatch detected)" */
2419 return PH_ERROR_PACK_SIGNATURE;
2420 if (!pack_version_ok(header->hdr_version))
2421 /* "protocol error (pack version unsupported)" */
2422 return PH_ERROR_PROTOCOL;
2423 return 0;
2424}