fast-import: introduce "feature notes" command
[git/git.git] / sha1_file.c
CommitLineData
0fcfd160
LT
1/*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 *
6 * This handles basic git sha1 object files - packing, unpacking,
7 * creation etc.
8 */
0fcfd160 9#include "cache.h"
1f688557 10#include "delta.h"
a733cb60 11#include "pack.h"
8e440259
PE
12#include "blob.h"
13#include "commit.h"
14#include "tag.h"
15#include "tree.h"
f35a6d3b 16#include "refs.h"
70f5d5d3 17#include "pack-revindex.h"
628522ec 18#include "sha1-lookup.h"
0fcfd160 19
144bde78
LT
20#ifndef O_NOATIME
21#if defined(__linux__) && (defined(__i386__) || defined(__PPC__))
22#define O_NOATIME 01000000
23#else
24#define O_NOATIME 0
25#endif
26#endif
27
e05db0fd
PR
28#ifdef NO_C99_FORMAT
29#define SZ_FMT "lu"
9e42d6a1 30static unsigned long sz_fmt(size_t s) { return (unsigned long)s; }
e05db0fd
PR
31#else
32#define SZ_FMT "zu"
9e42d6a1 33static size_t sz_fmt(size_t s) { return s; }
e05db0fd
PR
34#endif
35
96f1e58f 36const unsigned char null_sha1[20];
88cd621d 37
8385abfd
JS
38static inline int offset_1st_component(const char *path)
39{
40 if (has_dos_drive_prefix(path))
41 return 2 + (path[2] == '/');
42 return *path == '/';
43}
44
b2cb9425
JH
45int safe_create_leading_directories(char *path)
46{
8385abfd 47 char *pos = path + offset_1st_component(path);
67d42212
JR
48 struct stat st;
49
b2cb9425
JH
50 while (pos) {
51 pos = strchr(pos, '/');
52 if (!pos)
53 break;
5f0bdf50
JH
54 while (*++pos == '/')
55 ;
56 if (!*pos)
57 break;
58 *--pos = '\0';
67d42212
JR
59 if (!stat(path, &st)) {
60 /* path exists */
61 if (!S_ISDIR(st.st_mode)) {
b2cb9425 62 *pos = '/';
67d42212 63 return -3;
b2cb9425 64 }
457f06d6 65 }
67d42212
JR
66 else if (mkdir(path, 0777)) {
67 *pos = '/';
68 return -1;
69 }
457f06d6
JS
70 else if (adjust_shared_perm(path)) {
71 *pos = '/';
72 return -2;
73 }
b2cb9425
JH
74 *pos++ = '/';
75 }
76 return 0;
77}
723c31fe 78
8e21d63b
JK
79int safe_create_leading_directories_const(const char *path)
80{
81 /* path points to cache entries, so xstrdup before messing with it */
82 char *buf = xstrdup(path);
83 int result = safe_create_leading_directories(buf);
84 free(buf);
85 return result;
86}
87
ace1534d
JH
88static void fill_sha1_path(char *pathbuf, const unsigned char *sha1)
89{
90 int i;
91 for (i = 0; i < 20; i++) {
92 static char hex[] = "0123456789abcdef";
93 unsigned int val = sha1[i];
94 char *pos = pathbuf + i*2 + (i > 0);
95 *pos++ = hex[val >> 4];
96 *pos = hex[val & 0xf];
97 }
98}
99
0fcfd160
LT
100/*
101 * NOTE! This returns a statically allocated buffer, so you have to be
790296fd 102 * careful about using it. Do an "xstrdup()" if you need to save the
0fcfd160 103 * filename.
ace1534d
JH
104 *
105 * Also note that this returns the location for creating. Reading
106 * SHA1 file can happen from any alternate directory listed in the
d19938ab 107 * DB_ENVIRONMENT environment variable if it is not found in
ace1534d 108 * the primary object database.
0fcfd160
LT
109 */
110char *sha1_file_name(const unsigned char *sha1)
111{
0fcfd160
LT
112 static char *name, *base;
113
114 if (!base) {
d19938ab 115 const char *sha1_file_directory = get_object_directory();
0fcfd160 116 int len = strlen(sha1_file_directory);
812666c8 117 base = xmalloc(len + 60);
0fcfd160
LT
118 memcpy(base, sha1_file_directory, len);
119 memset(base+len, 0, 60);
120 base[len] = '/';
121 base[len+3] = '/';
122 name = base + len + 1;
123 }
ace1534d 124 fill_sha1_path(name, sha1);
0fcfd160
LT
125 return base;
126}
127
633f43e1 128static char *sha1_get_pack_name(const unsigned char *sha1,
6eec46bd 129 char **name, char **base, const char *which)
bf592c50
DB
130{
131 static const char hex[] = "0123456789abcdef";
633f43e1 132 char *buf;
bf592c50
DB
133 int i;
134
633f43e1 135 if (!*base) {
bf592c50
DB
136 const char *sha1_file_directory = get_object_directory();
137 int len = strlen(sha1_file_directory);
633f43e1 138 *base = xmalloc(len + 60);
6eec46bd
JH
139 sprintf(*base, "%s/pack/pack-1234567890123456789012345678901234567890.%s",
140 sha1_file_directory, which);
633f43e1 141 *name = *base + len + 11;
bf592c50
DB
142 }
143
633f43e1 144 buf = *name;
bf592c50
DB
145
146 for (i = 0; i < 20; i++) {
147 unsigned int val = *sha1++;
148 *buf++ = hex[val >> 4];
149 *buf++ = hex[val & 0xf];
150 }
a6080a0a 151
633f43e1 152 return *base;
bf592c50
DB
153}
154
633f43e1 155char *sha1_pack_name(const unsigned char *sha1)
bf592c50 156{
633f43e1 157 static char *name, *base;
bf592c50 158
6eec46bd 159 return sha1_get_pack_name(sha1, &name, &base, "pack");
633f43e1 160}
bf592c50 161
633f43e1
HO
162char *sha1_pack_index_name(const unsigned char *sha1)
163{
164 static char *name, *base;
a6080a0a 165
6eec46bd 166 return sha1_get_pack_name(sha1, &name, &base, "idx");
bf592c50
DB
167}
168
d5a63b99
JH
169struct alternate_object_database *alt_odb_list;
170static struct alternate_object_database **alt_odb_tail;
ace1534d 171
c2f493a4
MW
172static void read_info_alternates(const char * alternates, int depth);
173
ddd5d056
JH
174/*
175 * Prepare alternate object database registry.
d5a63b99
JH
176 *
177 * The variable alt_odb_list points at the list of struct
178 * alternate_object_database. The elements on this list come from
179 * non-empty elements from colon separated ALTERNATE_DB_ENVIRONMENT
180 * environment variable, and $GIT_OBJECT_DIRECTORY/info/alternates,
1494e038
JH
181 * whose contents is similar to that environment variable but can be
182 * LF separated. Its base points at a statically allocated buffer that
d5a63b99
JH
183 * contains "/the/directory/corresponding/to/.git/objects/...", while
184 * its name points just after the slash at the end of ".git/objects/"
185 * in the example above, and has enough space to hold 40-byte hex
186 * SHA1, an extra slash for the first level indirection, and the
187 * terminating NUL.
ddd5d056 188 */
c2f493a4 189static int link_alt_odb_entry(const char * entry, int len, const char * relative_base, int depth)
ace1534d 190{
1494e038 191 const char *objdir = get_object_directory();
c2f493a4
MW
192 struct alternate_object_database *ent;
193 struct alternate_object_database *alt;
194 /* 43 = 40-byte + 2 '/' + terminating NUL */
195 int pfxlen = len;
196 int entlen = pfxlen + 43;
ccfd3e99 197 int base_len = -1;
d5a63b99 198
85dadc38 199 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
200 /* Relative alt-odb */
201 if (base_len < 0)
202 base_len = strlen(relative_base) + 1;
203 entlen += base_len;
204 pfxlen += base_len;
205 }
206 ent = xmalloc(sizeof(*ent) + entlen);
207
85dadc38 208 if (!is_absolute_path(entry) && relative_base) {
c2f493a4
MW
209 memcpy(ent->base, relative_base, base_len - 1);
210 ent->base[base_len - 1] = '/';
211 memcpy(ent->base + base_len, entry, len);
212 }
213 else
214 memcpy(ent->base, entry, pfxlen);
215
216 ent->name = ent->base + pfxlen + 1;
217 ent->base[pfxlen + 3] = '/';
218 ent->base[pfxlen] = ent->base[entlen-1] = 0;
219
220 /* Detect cases where alternate disappeared */
90b4a71c 221 if (!is_directory(ent->base)) {
c2f493a4
MW
222 error("object directory %s does not exist; "
223 "check .git/objects/info/alternates.",
224 ent->base);
225 free(ent);
226 return -1;
227 }
228
229 /* Prevent the common mistake of listing the same
230 * thing twice, or object directory itself.
231 */
232 for (alt = alt_odb_list; alt; alt = alt->next) {
233 if (!memcmp(ent->base, alt->base, pfxlen)) {
234 free(ent);
235 return -1;
236 }
237 }
238 if (!memcmp(ent->base, objdir, pfxlen)) {
239 free(ent);
240 return -1;
241 }
242
243 /* add the alternate entry */
244 *alt_odb_tail = ent;
245 alt_odb_tail = &(ent->next);
246 ent->next = NULL;
247
248 /* recursively add alternates */
249 read_info_alternates(ent->base, depth + 1);
250
251 ent->base[pfxlen] = '/';
252
253 return 0;
254}
255
256static void link_alt_odb_entries(const char *alt, const char *ep, int sep,
257 const char *relative_base, int depth)
258{
259 const char *cp, *last;
260
261 if (depth > 5) {
262 error("%s: ignoring alternate object stores, nesting too deep.",
263 relative_base);
264 return;
265 }
266
d5a63b99 267 last = alt;
9577e7e3
JH
268 while (last < ep) {
269 cp = last;
270 if (cp < ep && *cp == '#') {
271 while (cp < ep && *cp != sep)
272 cp++;
273 last = cp + 1;
274 continue;
275 }
c2f493a4
MW
276 while (cp < ep && *cp != sep)
277 cp++;
d5a63b99 278 if (last != cp) {
85dadc38 279 if (!is_absolute_path(last) && depth) {
c2f493a4
MW
280 error("%s: ignoring relative alternate object store %s",
281 relative_base, last);
282 } else {
283 link_alt_odb_entry(last, cp - last,
284 relative_base, depth);
1494e038 285 }
d5a63b99 286 }
9577e7e3 287 while (cp < ep && *cp == sep)
d5a63b99
JH
288 cp++;
289 last = cp;
9577e7e3 290 }
d5a63b99
JH
291}
292
c2f493a4 293static void read_info_alternates(const char * relative_base, int depth)
d5a63b99 294{
9577e7e3 295 char *map;
dc49cd76 296 size_t mapsz;
d5a63b99 297 struct stat st;
9cb18f56
JM
298 const char alt_file_name[] = "info/alternates";
299 /* Given that relative_base is no longer than PATH_MAX,
300 ensure that "path" has enough space to append "/", the
301 file name, "info/alternates", and a trailing NUL. */
302 char path[PATH_MAX + 1 + sizeof alt_file_name];
c2f493a4 303 int fd;
d5a63b99 304
9cb18f56 305 sprintf(path, "%s/%s", relative_base, alt_file_name);
d5a63b99
JH
306 fd = open(path, O_RDONLY);
307 if (fd < 0)
308 return;
309 if (fstat(fd, &st) || (st.st_size == 0)) {
310 close(fd);
9a217f2a 311 return;
ace1534d 312 }
dc49cd76
SP
313 mapsz = xsize_t(st.st_size);
314 map = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, fd, 0);
d5a63b99 315 close(fd);
d5a63b99 316
dc49cd76 317 link_alt_odb_entries(map, map + mapsz, '\n', relative_base, depth);
c2f493a4 318
dc49cd76 319 munmap(map, mapsz);
ace1534d
JH
320}
321
bef70b22
DB
322void add_to_alternates_file(const char *reference)
323{
324 struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
acd3b9ec 325 int fd = hold_lock_file_for_append(lock, git_path("objects/info/alternates"), LOCK_DIE_ON_ERROR);
bef70b22
DB
326 char *alt = mkpath("%s/objects\n", reference);
327 write_or_die(fd, alt, strlen(alt));
328 if (commit_lock_file(lock))
329 die("could not close alternates file");
330 if (alt_odb_tail)
331 link_alt_odb_entries(alt, alt + strlen(alt), '\n', NULL, 0);
332}
333
d79796bc
JH
334void foreach_alt_odb(alt_odb_fn fn, void *cb)
335{
336 struct alternate_object_database *ent;
337
338 prepare_alt_odb();
339 for (ent = alt_odb_list; ent; ent = ent->next)
340 if (fn(ent, cb))
341 return;
342}
343
c2f493a4
MW
344void prepare_alt_odb(void)
345{
554fe20d 346 const char *alt;
c2f493a4 347
7dc24aa5
SP
348 if (alt_odb_tail)
349 return;
350
c2f493a4
MW
351 alt = getenv(ALTERNATE_DB_ENVIRONMENT);
352 if (!alt) alt = "";
353
c2f493a4 354 alt_odb_tail = &alt_odb_list;
80ba074f 355 link_alt_odb_entries(alt, alt + strlen(alt), PATH_SEP, NULL, 0);
c2f493a4
MW
356
357 read_info_alternates(get_object_directory(), 0);
358}
359
0f4dc14a 360static int has_loose_object_local(const unsigned char *sha1)
ace1534d 361{
ace1534d 362 char *name = sha1_file_name(sha1);
0f4dc14a
BC
363 return !access(name, F_OK);
364}
ace1534d 365
0f4dc14a
BC
366int has_loose_object_nonlocal(const unsigned char *sha1)
367{
368 struct alternate_object_database *alt;
9a217f2a 369 prepare_alt_odb();
d5a63b99 370 for (alt = alt_odb_list; alt; alt = alt->next) {
0f4dc14a 371 fill_sha1_path(alt->name, sha1);
c529d75a
LT
372 if (!access(alt->base, F_OK))
373 return 1;
ace1534d 374 }
c529d75a 375 return 0;
ace1534d
JH
376}
377
0f4dc14a
BC
378static int has_loose_object(const unsigned char *sha1)
379{
380 return has_loose_object_local(sha1) ||
381 has_loose_object_nonlocal(sha1);
382}
383
60bb8b14 384static unsigned int pack_used_ctr;
a53128b6
SP
385static unsigned int pack_mmap_calls;
386static unsigned int peak_pack_open_windows;
387static unsigned int pack_open_windows;
388static size_t peak_pack_mapped;
60bb8b14 389static size_t pack_mapped;
9a217f2a 390struct packed_git *packed_git;
1f688557 391
b79d18c9 392void pack_report(void)
a53128b6
SP
393{
394 fprintf(stderr,
e05db0fd
PR
395 "pack_report: getpagesize() = %10" SZ_FMT "\n"
396 "pack_report: core.packedGitWindowSize = %10" SZ_FMT "\n"
397 "pack_report: core.packedGitLimit = %10" SZ_FMT "\n",
9e42d6a1
SP
398 sz_fmt(getpagesize()),
399 sz_fmt(packed_git_window_size),
400 sz_fmt(packed_git_limit));
a53128b6
SP
401 fprintf(stderr,
402 "pack_report: pack_used_ctr = %10u\n"
403 "pack_report: pack_mmap_calls = %10u\n"
404 "pack_report: pack_open_windows = %10u / %10u\n"
e05db0fd
PR
405 "pack_report: pack_mapped = "
406 "%10" SZ_FMT " / %10" SZ_FMT "\n",
a53128b6
SP
407 pack_used_ctr,
408 pack_mmap_calls,
409 pack_open_windows, peak_pack_open_windows,
9e42d6a1 410 sz_fmt(pack_mapped), sz_fmt(peak_pack_mapped));
a53128b6
SP
411}
412
42873078 413static int check_packed_git_idx(const char *path, struct packed_git *p)
1f688557
JH
414{
415 void *idx_map;
42873078 416 struct pack_idx_header *hdr;
dc49cd76 417 size_t idx_size;
74e34e1f 418 uint32_t version, nr, i, *index;
e93ec6f9 419 int fd = open(path, O_RDONLY);
1f688557 420 struct stat st;
42873078 421
1f688557
JH
422 if (fd < 0)
423 return -1;
424 if (fstat(fd, &st)) {
425 close(fd);
426 return -1;
427 }
dc49cd76 428 idx_size = xsize_t(st.st_size);
2d88451b
SP
429 if (idx_size < 4 * 256 + 20 + 20) {
430 close(fd);
431 return error("index file %s is too small", path);
432 }
c4712e45 433 idx_map = xmmap(NULL, idx_size, PROT_READ, MAP_PRIVATE, fd, 0);
1f688557 434 close(fd);
1f688557 435
42873078
NP
436 hdr = idx_map;
437 if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) {
74e34e1f
NP
438 version = ntohl(hdr->idx_version);
439 if (version < 2 || version > 2) {
440 munmap(idx_map, idx_size);
6e1c2344 441 return error("index file %s is version %"PRIu32
74e34e1f
NP
442 " and is not supported by this binary"
443 " (try upgrading GIT to a newer version)",
444 path, version);
445 }
446 } else
447 version = 1;
df1b059d 448
1f688557 449 nr = 0;
42873078 450 index = idx_map;
74e34e1f
NP
451 if (version > 1)
452 index += 2; /* skip index header */
1f688557 453 for (i = 0; i < 256; i++) {
326bf396 454 uint32_t n = ntohl(index[i]);
2d88451b
SP
455 if (n < nr) {
456 munmap(idx_map, idx_size);
df1b059d 457 return error("non-monotonic index %s", path);
2d88451b 458 }
1f688557
JH
459 nr = n;
460 }
461
74e34e1f
NP
462 if (version == 1) {
463 /*
464 * Total size:
465 * - 256 index entries 4 bytes each
466 * - 24-byte entries * nr (20-byte sha1 + 4-byte offset)
467 * - 20-byte SHA1 of the packfile
468 * - 20-byte SHA1 file checksum
469 */
470 if (idx_size != 4*256 + nr * 24 + 20 + 20) {
471 munmap(idx_map, idx_size);
eef427a0 472 return error("wrong index v1 file size in %s", path);
74e34e1f
NP
473 }
474 } else if (version == 2) {
475 /*
476 * Minimum size:
477 * - 8 bytes of header
478 * - 256 index entries 4 bytes each
479 * - 20-byte sha1 entry * nr
480 * - 4-byte crc entry * nr
481 * - 4-byte offset entry * nr
482 * - 20-byte SHA1 of the packfile
483 * - 20-byte SHA1 file checksum
484 * And after the 4-byte offset table might be a
485 * variable sized table containing 8-byte entries
486 * for offsets larger than 2^31.
487 */
488 unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20;
1164f1e4
LT
489 unsigned long max_size = min_size;
490 if (nr)
491 max_size += (nr - 1)*8;
492 if (idx_size < min_size || idx_size > max_size) {
74e34e1f 493 munmap(idx_map, idx_size);
eef427a0 494 return error("wrong index v2 file size in %s", path);
74e34e1f 495 }
7109c889
JH
496 if (idx_size != min_size &&
497 /*
498 * make sure we can deal with large pack offsets.
499 * 31-bit signed offset won't be enough, neither
500 * 32-bit unsigned one will be.
501 */
502 (sizeof(off_t) <= 4)) {
503 munmap(idx_map, idx_size);
504 return error("pack too large for current definition of off_t in %s", path);
74e34e1f 505 }
2d88451b 506 }
1f688557 507
74e34e1f 508 p->index_version = version;
42873078
NP
509 p->index_data = idx_map;
510 p->index_size = idx_size;
57059091 511 p->num_objects = nr;
1f688557
JH
512 return 0;
513}
514
bc8e478a 515int open_pack_index(struct packed_git *p)
d079837e
SP
516{
517 char *idx_name;
518 int ret;
519
520 if (p->index_data)
521 return 0;
522
523 idx_name = xstrdup(p->pack_name);
524 strcpy(idx_name + strlen(idx_name) - strlen(".pack"), ".idx");
525 ret = check_packed_git_idx(idx_name, p);
526 free(idx_name);
527 return ret;
528}
529
11daf39b
SP
530static void scan_windows(struct packed_git *p,
531 struct packed_git **lru_p,
532 struct pack_window **lru_w,
533 struct pack_window **lru_l)
1f688557 534{
11daf39b
SP
535 struct pack_window *w, *w_l;
536
537 for (w_l = NULL, w = p->windows; w; w = w->next) {
538 if (!w->inuse_cnt) {
539 if (!*lru_w || w->last_used < (*lru_w)->last_used) {
540 *lru_p = p;
541 *lru_w = w;
542 *lru_l = w_l;
54044bf8 543 }
54044bf8 544 }
11daf39b 545 w_l = w;
f9253394 546 }
11daf39b
SP
547}
548
d1efefa4 549static int unuse_one_window(struct packed_git *current, int keep_fd)
11daf39b
SP
550{
551 struct packed_git *p, *lru_p = NULL;
552 struct pack_window *lru_w = NULL, *lru_l = NULL;
553
554 if (current)
555 scan_windows(current, &lru_p, &lru_w, &lru_l);
556 for (p = packed_git; p; p = p->next)
557 scan_windows(p, &lru_p, &lru_w, &lru_l);
54044bf8
SP
558 if (lru_p) {
559 munmap(lru_w->base, lru_w->len);
560 pack_mapped -= lru_w->len;
561 if (lru_l)
562 lru_l->next = lru_w->next;
563 else {
564 lru_p->windows = lru_w->next;
d1efefa4 565 if (!lru_p->windows && lru_p->pack_fd != keep_fd) {
54044bf8
SP
566 close(lru_p->pack_fd);
567 lru_p->pack_fd = -1;
568 }
569 }
570 free(lru_w);
a53128b6 571 pack_open_windows--;
54044bf8
SP
572 return 1;
573 }
574 return 0;
f9253394
JH
575}
576
d1efefa4 577void release_pack_memory(size_t need, int fd)
97bfeb34
SP
578{
579 size_t cur = pack_mapped;
d1efefa4 580 while (need >= (cur - pack_mapped) && unuse_one_window(NULL, fd))
97bfeb34
SP
581 ; /* nothing */
582}
583
c9ced051
SP
584void close_pack_windows(struct packed_git *p)
585{
586 while (p->windows) {
587 struct pack_window *w = p->windows;
588
589 if (w->inuse_cnt)
590 die("pack '%s' still has open windows to it",
591 p->pack_name);
592 munmap(w->base, w->len);
593 pack_mapped -= w->len;
594 pack_open_windows--;
595 p->windows = w->next;
596 free(w);
597 }
598}
599
03e79c88 600void unuse_pack(struct pack_window **w_cursor)
f9253394 601{
03e79c88
SP
602 struct pack_window *w = *w_cursor;
603 if (w) {
604 w->inuse_cnt--;
605 *w_cursor = NULL;
606 }
1f688557
JH
607}
608
c74faea1
NP
609/*
610 * This is used by git-repack in case a newly created pack happens to
611 * contain the same set of objects as an existing one. In that case
612 * the resulting file might be different even if its name would be the
613 * same. It is best to close any reference to the old pack before it is
614 * replaced on disk. Of course no index pointers nor windows for given pack
615 * must subsist at this point. If ever objects from this pack are requested
616 * again, the new version of the pack will be reinitialized through
617 * reprepare_packed_git().
618 */
619void free_pack_by_name(const char *pack_name)
620{
621 struct packed_git *p, **pp = &packed_git;
622
623 while (*pp) {
624 p = *pp;
625 if (strcmp(pack_name, p->pack_name) == 0) {
fa3a0c94 626 clear_delta_base_cache();
c74faea1
NP
627 close_pack_windows(p);
628 if (p->pack_fd != -1)
629 close(p->pack_fd);
630 if (p->index_data)
631 munmap((void *)p->index_data, p->index_size);
632 free(p->bad_object_sha1);
633 *pp = p->next;
634 free(p);
635 return;
636 }
637 pp = &p->next;
638 }
639}
640
3cf8b462
SP
641/*
642 * Do not call this directly as this leaks p->pack_fd on error return;
643 * call open_packed_git() instead.
644 */
645static int open_packed_git_1(struct packed_git *p)
1f688557 646{
9bc879c1
SP
647 struct stat st;
648 struct pack_header hdr;
649 unsigned char sha1[20];
650 unsigned char *idx_sha1;
2c039da8 651 long fd_flag;
9bc879c1 652
d079837e
SP
653 if (!p->index_data && open_pack_index(p))
654 return error("packfile %s index unavailable", p->pack_name);
655
9bc879c1 656 p->pack_fd = open(p->pack_name, O_RDONLY);
fd73ccf2
JS
657 while (p->pack_fd < 0 && errno == EMFILE && unuse_one_window(p, -1))
658 p->pack_fd = open(p->pack_name, O_RDONLY);
9bc879c1 659 if (p->pack_fd < 0 || fstat(p->pack_fd, &st))
072db278 660 return -1;
9bc879c1
SP
661
662 /* If we created the struct before we had the pack we lack size. */
bf592c50 663 if (!p->pack_size) {
bf592c50 664 if (!S_ISREG(st.st_mode))
072db278 665 return error("packfile %s not a regular file", p->pack_name);
bf592c50 666 p->pack_size = st.st_size;
9bc879c1 667 } else if (p->pack_size != st.st_size)
072db278 668 return error("packfile %s size changed", p->pack_name);
9bc879c1 669
2c039da8
JH
670 /* We leave these file descriptors open with sliding mmap;
671 * there is no point keeping them open across exec(), though.
672 */
673 fd_flag = fcntl(p->pack_fd, F_GETFD, 0);
674 if (fd_flag < 0)
072db278 675 return error("cannot determine file descriptor flags");
2c039da8
JH
676 fd_flag |= FD_CLOEXEC;
677 if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1)
072db278 678 return error("cannot set FD_CLOEXEC");
2c039da8 679
9bc879c1 680 /* Verify we recognize this pack file format. */
e6e2bd62 681 if (read_in_full(p->pack_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
072db278 682 return error("file %s is far too short to be a packfile", p->pack_name);
9bc879c1 683 if (hdr.hdr_signature != htonl(PACK_SIGNATURE))
072db278 684 return error("file %s is not a GIT packfile", p->pack_name);
9bc879c1 685 if (!pack_version_ok(hdr.hdr_version))
6e1c2344
RJ
686 return error("packfile %s is version %"PRIu32" and not"
687 " supported (try upgrading GIT to a newer version)",
9bc879c1
SP
688 p->pack_name, ntohl(hdr.hdr_version));
689
690 /* Verify the pack matches its index. */
57059091 691 if (p->num_objects != ntohl(hdr.hdr_entries))
6e1c2344
RJ
692 return error("packfile %s claims to have %"PRIu32" objects"
693 " while index indicates %"PRIu32" objects",
57059091
NP
694 p->pack_name, ntohl(hdr.hdr_entries),
695 p->num_objects);
9bc879c1 696 if (lseek(p->pack_fd, p->pack_size - sizeof(sha1), SEEK_SET) == -1)
072db278 697 return error("end of packfile %s is unavailable", p->pack_name);
e6e2bd62 698 if (read_in_full(p->pack_fd, sha1, sizeof(sha1)) != sizeof(sha1))
072db278 699 return error("packfile %s signature is unavailable", p->pack_name);
42873078 700 idx_sha1 = ((unsigned char *)p->index_data) + p->index_size - 40;
9bc879c1 701 if (hashcmp(sha1, idx_sha1))
072db278
SP
702 return error("packfile %s does not match index", p->pack_name);
703 return 0;
9bc879c1
SP
704}
705
3cf8b462
SP
706static int open_packed_git(struct packed_git *p)
707{
708 if (!open_packed_git_1(p))
709 return 0;
710 if (p->pack_fd != -1) {
711 close(p->pack_fd);
712 p->pack_fd = -1;
713 }
714 return -1;
715}
716
c4001d92 717static int in_window(struct pack_window *win, off_t offset)
60bb8b14
SP
718{
719 /* We must promise at least 20 bytes (one hash) after the
720 * offset is available from this window, otherwise the offset
721 * is not actually in this window and a different window (which
722 * has that one hash excess) must be used. This is to support
723 * the object header and delta base parsing routines below.
724 */
725 off_t win_off = win->offset;
726 return win_off <= offset
727 && (offset + 20) <= (win_off + win->len);
728}
729
4b25d091 730unsigned char *use_pack(struct packed_git *p,
03e79c88 731 struct pack_window **w_cursor,
c4001d92 732 off_t offset,
03e79c88 733 unsigned int *left)
9bc879c1 734{
60bb8b14 735 struct pack_window *win = *w_cursor;
03e79c88 736
072db278
SP
737 if (p->pack_fd == -1 && open_packed_git(p))
738 die("packfile %s cannot be accessed", p->pack_name);
60bb8b14 739
a9d98a14 740 /* Since packfiles end in a hash of their content and it's
60bb8b14
SP
741 * pointless to ask for an offset into the middle of that
742 * hash, and the in_window function above wouldn't match
743 * don't allow an offset too close to the end of the file.
744 */
745 if (offset > (p->pack_size - 20))
746 die("offset beyond end of packfile (truncated pack?)");
747
748 if (!win || !in_window(win, offset)) {
749 if (win)
750 win->inuse_cnt--;
751 for (win = p->windows; win; win = win->next) {
752 if (in_window(win, offset))
753 break;
754 }
755 if (!win) {
78a28df9 756 size_t window_align = packed_git_window_size / 2;
dc49cd76 757 off_t len;
60bb8b14 758 win = xcalloc(1, sizeof(*win));
78a28df9 759 win->offset = (offset / window_align) * window_align;
dc49cd76
SP
760 len = p->pack_size - win->offset;
761 if (len > packed_git_window_size)
762 len = packed_git_window_size;
763 win->len = (size_t)len;
60bb8b14 764 pack_mapped += win->len;
11daf39b 765 while (packed_git_limit < pack_mapped
d1efefa4 766 && unuse_one_window(p, p->pack_fd))
60bb8b14 767 ; /* nothing */
c4712e45 768 win->base = xmmap(NULL, win->len,
60bb8b14
SP
769 PROT_READ, MAP_PRIVATE,
770 p->pack_fd, win->offset);
771 if (win->base == MAP_FAILED)
73b4e4be
SP
772 die("packfile %s cannot be mapped: %s",
773 p->pack_name,
774 strerror(errno));
a53128b6
SP
775 pack_mmap_calls++;
776 pack_open_windows++;
777 if (pack_mapped > peak_pack_mapped)
778 peak_pack_mapped = pack_mapped;
779 if (pack_open_windows > peak_pack_open_windows)
780 peak_pack_open_windows = pack_open_windows;
60bb8b14
SP
781 win->next = p->windows;
782 p->windows = win;
783 }
1f688557 784 }
03e79c88
SP
785 if (win != *w_cursor) {
786 win->last_used = pack_used_ctr++;
787 win->inuse_cnt++;
788 *w_cursor = win;
789 }
60bb8b14 790 offset -= win->offset;
03e79c88 791 if (left)
dc49cd76 792 *left = win->len - xsize_t(offset);
03e79c88 793 return win->base + offset;
1f688557
JH
794}
795
27d69a46
NP
796static struct packed_git *alloc_packed_git(int extra)
797{
798 struct packed_git *p = xmalloc(sizeof(*p) + extra);
799 memset(p, 0, sizeof(*p));
800 p->pack_fd = -1;
801 return p;
802}
803
42873078 804struct packed_git *add_packed_git(const char *path, int path_len, int local)
1f688557
JH
805{
806 struct stat st;
27d69a46 807 struct packed_git *p = alloc_packed_git(path_len + 2);
1f688557 808
42873078
NP
809 /*
810 * Make sure a corresponding .pack file exists and that
811 * the index looks sane.
812 */
813 path_len -= strlen(".idx");
27d69a46
NP
814 if (path_len < 1) {
815 free(p);
1f688557 816 return NULL;
27d69a46 817 }
42873078 818 memcpy(p->pack_name, path, path_len);
8d25931d
BC
819
820 strcpy(p->pack_name + path_len, ".keep");
821 if (!access(p->pack_name, F_OK))
822 p->pack_keep = 1;
823
42873078 824 strcpy(p->pack_name + path_len, ".pack");
d079837e 825 if (stat(p->pack_name, &st) || !S_ISREG(st.st_mode)) {
42873078 826 free(p);
1f688557
JH
827 return NULL;
828 }
42873078 829
1f688557
JH
830 /* ok, it looks sane as far as we can check without
831 * actually mapping the pack file.
832 */
1f688557 833 p->pack_size = st.st_size;
9d835df2 834 p->pack_local = local;
b867092f 835 p->mtime = st.st_mtime;
42873078
NP
836 if (path_len < 40 || get_sha1_hex(path + path_len - 40, p->sha1))
837 hashclr(p->sha1);
1f688557
JH
838 return p;
839}
840
bf592c50 841struct packed_git *parse_pack_index(unsigned char *sha1)
c508df5e 842{
79c6dca4 843 const char *idx_path = sha1_pack_index_name(sha1);
42873078 844 const char *path = sha1_pack_name(sha1);
27d69a46 845 struct packed_git *p = alloc_packed_git(strlen(path) + 1);
bf592c50 846
27d69a46
NP
847 strcpy(p->pack_name, path);
848 hashcpy(p->sha1, sha1);
42873078
NP
849 if (check_packed_git_idx(idx_path, p)) {
850 free(p);
bf592c50 851 return NULL;
42873078 852 }
bf592c50 853
bf592c50
DB
854 return p;
855}
856
857void install_packed_git(struct packed_git *pack)
858{
859 pack->next = packed_git;
860 packed_git = pack;
861}
862
9d835df2 863static void prepare_packed_git_one(char *objdir, int local)
1f688557 864{
9cb18f56
JM
865 /* Ensure that this buffer is large enough so that we can
866 append "/pack/" without clobbering the stack even if
867 strlen(objdir) were PATH_MAX. */
868 char path[PATH_MAX + 1 + 4 + 1 + 1];
1f688557
JH
869 int len;
870 DIR *dir;
871 struct dirent *de;
872
873 sprintf(path, "%s/pack", objdir);
874 len = strlen(path);
875 dir = opendir(path);
fd73ccf2
JS
876 while (!dir && errno == EMFILE && unuse_one_window(packed_git, -1))
877 dir = opendir(path);
b5b16990 878 if (!dir) {
26125f6b 879 if (errno != ENOENT)
bd2afde8 880 error("unable to open object pack directory: %s: %s",
26125f6b 881 path, strerror(errno));
1f688557 882 return;
b5b16990 883 }
1f688557
JH
884 path[len++] = '/';
885 while ((de = readdir(dir)) != NULL) {
886 int namelen = strlen(de->d_name);
887 struct packed_git *p;
888
5bb1cda5 889 if (!has_extension(de->d_name, ".idx"))
1f688557
JH
890 continue;
891
9cb18f56
JM
892 if (len + namelen + 1 > sizeof(path))
893 continue;
894
54a15a8d 895 /* Don't reopen a pack we already have. */
1f688557 896 strcpy(path + len, de->d_name);
86f7780c
JK
897 for (p = packed_git; p; p = p->next) {
898 if (!memcmp(path, p->pack_name, len + namelen - 4))
899 break;
900 }
901 if (p)
902 continue;
54a15a8d
SP
903 /* See if it really is a valid .idx file with corresponding
904 * .pack file that we can map.
905 */
9d835df2 906 p = add_packed_git(path, len + namelen, local);
1f688557
JH
907 if (!p)
908 continue;
625e9421 909 install_packed_git(p);
1f688557 910 }
5b35bcd5 911 closedir(dir);
1f688557
JH
912}
913
b867092f
JH
914static int sort_pack(const void *a_, const void *b_)
915{
916 struct packed_git *a = *((struct packed_git **)a_);
917 struct packed_git *b = *((struct packed_git **)b_);
918 int st;
919
920 /*
921 * Local packs tend to contain objects specific to our
922 * variant of the project than remote ones. In addition,
923 * remote ones could be on a network mounted filesystem.
924 * Favor local ones for these reasons.
925 */
926 st = a->pack_local - b->pack_local;
927 if (st)
928 return -st;
929
930 /*
931 * Younger packs tend to contain more recent objects,
932 * and more recent objects tend to get accessed more
933 * often.
934 */
935 if (a->mtime < b->mtime)
936 return 1;
937 else if (a->mtime == b->mtime)
938 return 0;
939 return -1;
940}
941
942static void rearrange_packed_git(void)
943{
944 struct packed_git **ary, *p;
945 int i, n;
946
947 for (n = 0, p = packed_git; p; p = p->next)
948 n++;
949 if (n < 2)
950 return;
951
952 /* prepare an array of packed_git for easier sorting */
953 ary = xcalloc(n, sizeof(struct packed_git *));
954 for (n = 0, p = packed_git; p; p = p->next)
955 ary[n++] = p;
956
957 qsort(ary, n, sizeof(struct packed_git *), sort_pack);
958
959 /* link them back again */
960 for (i = 0; i < n - 1; i++)
961 ary[i]->next = ary[i + 1];
962 ary[n - 1]->next = NULL;
963 packed_git = ary[0];
964
965 free(ary);
966}
967
637cdd9d 968static int prepare_packed_git_run_once = 0;
9a217f2a 969void prepare_packed_git(void)
1f688557 970{
d5a63b99 971 struct alternate_object_database *alt;
1f688557 972
637cdd9d 973 if (prepare_packed_git_run_once)
1f688557 974 return;
9d835df2 975 prepare_packed_git_one(get_object_directory(), 1);
9a217f2a 976 prepare_alt_odb();
d5a63b99 977 for (alt = alt_odb_list; alt; alt = alt->next) {
1494e038 978 alt->name[-1] = 0;
9d835df2 979 prepare_packed_git_one(alt->base, 0);
1494e038 980 alt->name[-1] = '/';
1f688557 981 }
b867092f 982 rearrange_packed_git();
637cdd9d
JK
983 prepare_packed_git_run_once = 1;
984}
985
fc04c412 986void reprepare_packed_git(void)
637cdd9d 987{
4b480c67 988 discard_revindex();
637cdd9d
JK
989 prepare_packed_git_run_once = 0;
990 prepare_packed_git();
1f688557
JH
991}
992
8eca0b47
NP
993static void mark_bad_packed_object(struct packed_git *p,
994 const unsigned char *sha1)
995{
996 unsigned i;
997 for (i = 0; i < p->num_bad_objects; i++)
998 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
999 return;
1000 p->bad_object_sha1 = xrealloc(p->bad_object_sha1, 20 * (p->num_bad_objects + 1));
1001 hashcpy(p->bad_object_sha1 + 20 * p->num_bad_objects, sha1);
1002 p->num_bad_objects++;
1003}
1004
ac939109
NP
1005static int has_packed_and_bad(const unsigned char *sha1)
1006{
1007 struct packed_git *p;
1008 unsigned i;
1009
1010 for (p = packed_git; p; p = p->next)
1011 for (i = 0; i < p->num_bad_objects; i++)
1012 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1013 return 1;
1014 return 0;
1015}
1016
5d6ccf5c 1017int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type)
0fcfd160
LT
1018{
1019 unsigned char real_sha1[20];
7cfb5f36 1020 hash_sha1_file(map, size, type, real_sha1);
a89fccd2 1021 return hashcmp(sha1, real_sha1) ? -1 : 0;
0fcfd160
LT
1022}
1023
44d1c19e
LT
1024static int git_open_noatime(const char *name)
1025{
1026 static int sha1_file_open_flag = O_NOATIME;
1027 int fd = open(name, O_RDONLY | sha1_file_open_flag);
1028
1029 /* Might the failure be due to O_NOATIME? */
1030 if (fd < 0 && errno != ENOENT && sha1_file_open_flag) {
1031 fd = open(name, O_RDONLY);
1032 if (fd >= 0)
1033 sha1_file_open_flag = 0;
1034 }
1035 return fd;
1036}
1037
1038static int open_sha1_file(const unsigned char *sha1)
1039{
1040 int fd;
1041 char *name = sha1_file_name(sha1);
1042 struct alternate_object_database *alt;
1043
1044 fd = git_open_noatime(name);
1045 if (fd >= 0)
1046 return fd;
1047
1048 prepare_alt_odb();
1049 errno = ENOENT;
1050 for (alt = alt_odb_list; alt; alt = alt->next) {
1051 name = alt->name;
1052 fill_sha1_path(name, sha1);
1053 fd = git_open_noatime(alt->base);
1054 if (fd >= 0)
1055 return fd;
1056 }
1057 return -1;
1058}
1059
4175e9e3 1060static void *map_sha1_file(const unsigned char *sha1, unsigned long *size)
0fcfd160 1061{
0fcfd160 1062 void *map;
144bde78 1063 int fd;
ace1534d 1064
44d1c19e
LT
1065 fd = open_sha1_file(sha1);
1066 map = NULL;
1067 if (fd >= 0) {
1068 struct stat st;
0fcfd160 1069
44d1c19e
LT
1070 if (!fstat(fd, &st)) {
1071 *size = xsize_t(st.st_size);
1072 map = xmmap(NULL, *size, PROT_READ, MAP_PRIVATE, fd, 0);
144bde78 1073 }
44d1c19e 1074 close(fd);
0fcfd160 1075 }
0fcfd160
LT
1076 return map;
1077}
1078
726f852b 1079static int legacy_loose_object(unsigned char *map)
bb6b8e4f
JH
1080{
1081 unsigned int word;
1082
1083 /*
1084 * Is it a zlib-compressed buffer? If so, the first byte
1085 * must be 0x78 (15-bit window size, deflated), and the
1086 * first 16-bit word is evenly divisible by 31
1087 */
1088 word = (map[0] << 8) + map[1];
1089 if (map[0] == 0x78 && !(word % 31))
1090 return 1;
1091 else
1092 return 0;
1093}
1094
09ded04b
NP
1095unsigned long unpack_object_header_buffer(const unsigned char *buf,
1096 unsigned long len, enum object_type *type, unsigned long *sizep)
c4483576 1097{
ad1ed5ee 1098 unsigned shift;
48fb7deb 1099 unsigned long size, c;
ad1ed5ee
JH
1100 unsigned long used = 0;
1101
1102 c = buf[used++];
1103 *type = (c >> 4) & 7;
1104 size = c & 15;
1105 shift = 4;
1106 while (c & 0x80) {
f630cfda 1107 if (len <= used || bitsizeof(long) <= shift) {
09ded04b 1108 error("bad object header");
ad1ed5ee 1109 return 0;
09ded04b 1110 }
ad1ed5ee
JH
1111 c = buf[used++];
1112 size += (c & 0x7f) << shift;
1113 shift += 7;
1114 }
1115 *sizep = size;
1116 return used;
1117}
1118
1119static int unpack_sha1_header(z_stream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz)
1120{
1121 unsigned long size, used;
1122 static const char valid_loose_object_type[8] = {
1123 0, /* OBJ_EXT */
1124 1, 1, 1, 1, /* "commit", "tree", "blob", "tag" */
1125 0, /* "delta" and others are invalid in a loose object */
93821bd9 1126 };
ad1ed5ee 1127 enum object_type type;
93821bd9 1128
c4483576
LT
1129 /* Get the data stream */
1130 memset(stream, 0, sizeof(*stream));
1131 stream->next_in = map;
1132 stream->avail_in = mapsize;
1133 stream->next_out = buffer;
93821bd9
LT
1134 stream->avail_out = bufsiz;
1135
bb6b8e4f 1136 if (legacy_loose_object(map)) {
39c68542
LT
1137 git_inflate_init(stream);
1138 return git_inflate(stream, 0);
93821bd9
LT
1139 }
1140
726f852b
NP
1141
1142 /*
1143 * There used to be a second loose object header format which
1144 * was meant to mimic the in-pack format, allowing for direct
1145 * copy of the object data. This format turned up not to be
1146 * really worth it and we don't write it any longer. But we
1147 * can still read it.
1148 */
09ded04b 1149 used = unpack_object_header_buffer(map, mapsize, &type, &size);
ad1ed5ee 1150 if (!used || !valid_loose_object_type[type])
93821bd9 1151 return -1;
ad1ed5ee
JH
1152 map += used;
1153 mapsize -= used;
93821bd9
LT
1154
1155 /* Set up the stream for the rest.. */
1156 stream->next_in = map;
1157 stream->avail_in = mapsize;
39c68542 1158 git_inflate_init(stream);
93821bd9
LT
1159
1160 /* And generate the fake traditional header */
ad1ed5ee 1161 stream->total_out = 1 + snprintf(buffer, bufsiz, "%s %lu",
df843662 1162 typename(type), size);
93821bd9 1163 return 0;
c4483576
LT
1164}
1165
7efbff75 1166static void *unpack_sha1_rest(z_stream *stream, void *buffer, unsigned long size, const unsigned char *sha1)
5180cacc
LT
1167{
1168 int bytes = strlen(buffer) + 1;
3aee68aa 1169 unsigned char *buf = xmallocz(size);
93821bd9 1170 unsigned long n;
7efbff75 1171 int status = Z_OK;
5180cacc 1172
93821bd9
LT
1173 n = stream->total_out - bytes;
1174 if (n > size)
1175 n = size;
1176 memcpy(buf, (char *) buffer + bytes, n);
1177 bytes = n;
456cdf6e
LT
1178 if (bytes <= size) {
1179 /*
1180 * The above condition must be (bytes <= size), not
1181 * (bytes < size). In other words, even though we
1182 * expect no more output and set avail_out to zer0,
1183 * the input zlib stream may have bytes that express
1184 * "this concludes the stream", and we *do* want to
1185 * eat that input.
1186 *
1187 * Otherwise we would not be able to test that we
1188 * consumed all the input to reach the expected size;
1189 * we also want to check that zlib tells us that all
1190 * went well with status == Z_STREAM_END at the end.
1191 */
5180cacc
LT
1192 stream->next_out = buf + bytes;
1193 stream->avail_out = size - bytes;
7efbff75 1194 while (status == Z_OK)
39c68542 1195 status = git_inflate(stream, Z_FINISH);
5180cacc 1196 }
456cdf6e 1197 if (status == Z_STREAM_END && !stream->avail_in) {
39c68542 1198 git_inflate_end(stream);
7efbff75
JH
1199 return buf;
1200 }
1201
1202 if (status < 0)
1203 error("corrupt loose object '%s'", sha1_to_hex(sha1));
1204 else if (stream->avail_in)
1205 error("garbage at end of loose object '%s'",
1206 sha1_to_hex(sha1));
1207 free(buf);
1208 return NULL;
5180cacc
LT
1209}
1210
1211/*
1212 * We used to just use "sscanf()", but that's actually way
1213 * too permissive for what we want to check. So do an anal
1214 * object header parse by hand.
1215 */
21666f1a 1216static int parse_sha1_header(const char *hdr, unsigned long *sizep)
5180cacc 1217{
21666f1a 1218 char type[10];
5180cacc
LT
1219 int i;
1220 unsigned long size;
1221
1222 /*
a6080a0a 1223 * The type can be at most ten bytes (including the
5180cacc 1224 * terminating '\0' that we add), and is followed by
21666f1a 1225 * a space.
5180cacc 1226 */
21666f1a 1227 i = 0;
5180cacc
LT
1228 for (;;) {
1229 char c = *hdr++;
1230 if (c == ' ')
1231 break;
21666f1a
NP
1232 type[i++] = c;
1233 if (i >= sizeof(type))
5180cacc 1234 return -1;
5180cacc 1235 }
21666f1a 1236 type[i] = 0;
5180cacc
LT
1237
1238 /*
1239 * The length must follow immediately, and be in canonical
1240 * decimal format (ie "010" is not valid).
1241 */
1242 size = *hdr++ - '0';
1243 if (size > 9)
1244 return -1;
1245 if (size) {
1246 for (;;) {
1247 unsigned long c = *hdr - '0';
1248 if (c > 9)
1249 break;
1250 hdr++;
1251 size = size * 10 + c;
1252 }
1253 }
1254 *sizep = size;
1255
1256 /*
1257 * The length must be followed by a zero byte
1258 */
21666f1a 1259 return *hdr ? -1 : type_from_string(type);
5180cacc
LT
1260}
1261
7efbff75 1262static void *unpack_sha1_file(void *map, unsigned long mapsize, enum object_type *type, unsigned long *size, const unsigned char *sha1)
0fcfd160 1263{
5180cacc 1264 int ret;
0fcfd160 1265 z_stream stream;
5180cacc 1266 char hdr[8192];
0fcfd160 1267
5180cacc 1268 ret = unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr));
21666f1a 1269 if (ret < Z_OK || (*type = parse_sha1_header(hdr, size)) < 0)
0fcfd160
LT
1270 return NULL;
1271
7efbff75 1272 return unpack_sha1_rest(&stream, hdr, *size, sha1);
0fcfd160
LT
1273}
1274
54dab52a
NP
1275unsigned long get_size_from_delta(struct packed_git *p,
1276 struct pack_window **w_curs,
1277 off_t curpos)
1278{
1279 const unsigned char *data;
1280 unsigned char delta_head[20], *in;
1281 z_stream stream;
1282 int st;
1283
1284 memset(&stream, 0, sizeof(stream));
1285 stream.next_out = delta_head;
1286 stream.avail_out = sizeof(delta_head);
1287
39c68542 1288 git_inflate_init(&stream);
54dab52a
NP
1289 do {
1290 in = use_pack(p, w_curs, curpos, &stream.avail_in);
1291 stream.next_in = in;
39c68542 1292 st = git_inflate(&stream, Z_FINISH);
54dab52a
NP
1293 curpos += stream.next_in - in;
1294 } while ((st == Z_OK || st == Z_BUF_ERROR) &&
1295 stream.total_out < sizeof(delta_head));
39c68542 1296 git_inflate_end(&stream);
3d77d877
NP
1297 if ((st != Z_STREAM_END) && stream.total_out != sizeof(delta_head)) {
1298 error("delta data unpack-initial failed");
1299 return 0;
1300 }
54dab52a
NP
1301
1302 /* Examine the initial part of the delta to figure out
1303 * the result size.
1304 */
1305 data = delta_head;
1306
1307 /* ignore base size */
1308 get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1309
1310 /* Read the result size */
1311 return get_delta_hdr_size(&data, delta_head+sizeof(delta_head));
1312}
1313
c4001d92 1314static off_t get_delta_base(struct packed_git *p,
03e79c88 1315 struct pack_window **w_curs,
c4001d92 1316 off_t *curpos,
21666f1a 1317 enum object_type type,
c4001d92 1318 off_t delta_obj_offset)
eb32d236 1319{
2b87c45b 1320 unsigned char *base_info = use_pack(p, w_curs, *curpos, NULL);
c4001d92 1321 off_t base_offset;
eb32d236 1322
8d8a4ea5
SP
1323 /* use_pack() assured us we have [base_info, base_info + 20)
1324 * as a range that we can look at without walking off the
1325 * end of the mapped window. Its actually the hash size
1326 * that is assured. An OFS_DELTA longer than the hash size
1327 * is stupid, as then a REF_DELTA would be smaller to store.
1328 */
21666f1a 1329 if (type == OBJ_OFS_DELTA) {
eb32d236
NP
1330 unsigned used = 0;
1331 unsigned char c = base_info[used++];
1332 base_offset = c & 127;
1333 while (c & 128) {
1334 base_offset += 1;
8723f216 1335 if (!base_offset || MSB(base_offset, 7))
8eca0b47 1336 return 0; /* overflow */
eb32d236
NP
1337 c = base_info[used++];
1338 base_offset = (base_offset << 7) + (c & 127);
1339 }
1340 base_offset = delta_obj_offset - base_offset;
d8f32556 1341 if (base_offset <= 0 || base_offset >= delta_obj_offset)
8eca0b47 1342 return 0; /* out of bound */
2b87c45b 1343 *curpos += used;
21666f1a 1344 } else if (type == OBJ_REF_DELTA) {
eb32d236
NP
1345 /* The base entry _must_ be in the same pack */
1346 base_offset = find_pack_entry_one(base_info, p);
2b87c45b 1347 *curpos += 20;
eb32d236
NP
1348 } else
1349 die("I am totally screwed");
2b87c45b 1350 return base_offset;
eb32d236
NP
1351}
1352
f3bf9224 1353/* forward declaration for a mutually recursive function */
c4001d92 1354static int packed_object_info(struct packed_git *p, off_t offset,
21666f1a 1355 unsigned long *sizep);
f3bf9224 1356
43057304 1357static int packed_delta_info(struct packed_git *p,
03e79c88 1358 struct pack_window **w_curs,
c4001d92 1359 off_t curpos,
21666f1a 1360 enum object_type type,
c4001d92 1361 off_t obj_offset,
43057304 1362 unsigned long *sizep)
5db47c2b 1363{
c4001d92 1364 off_t base_offset;
f3bf9224 1365
21666f1a 1366 base_offset = get_delta_base(p, w_curs, &curpos, type, obj_offset);
3d77d877
NP
1367 if (!base_offset)
1368 return OBJ_BAD;
21666f1a 1369 type = packed_object_info(p, base_offset, NULL);
3d77d877 1370 if (type <= OBJ_NONE) {
08698b1e
NP
1371 struct revindex_entry *revidx;
1372 const unsigned char *base_sha1;
1373 revidx = find_pack_revindex(p, base_offset);
1374 if (!revidx)
1375 return OBJ_BAD;
1376 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
3d77d877
NP
1377 mark_bad_packed_object(p, base_sha1);
1378 type = sha1_object_info(base_sha1, NULL);
1379 if (type <= OBJ_NONE)
1380 return OBJ_BAD;
1381 }
f3bf9224 1382
c62266f3
JH
1383 /* We choose to only get the type of the base object and
1384 * ignore potentially corrupt pack file that expects the delta
1385 * based on a base with a wrong size. This saves tons of
1386 * inflate() calls.
1387 */
3d77d877 1388 if (sizep) {
54dab52a 1389 *sizep = get_size_from_delta(p, w_curs, curpos);
3d77d877
NP
1390 if (*sizep == 0)
1391 type = OBJ_BAD;
1392 }
21666f1a
NP
1393
1394 return type;
5db47c2b
JH
1395}
1396
2b87c45b
NP
1397static int unpack_object_header(struct packed_git *p,
1398 struct pack_window **w_curs,
c4001d92 1399 off_t *curpos,
2b87c45b 1400 unsigned long *sizep)
a733cb60 1401{
03e79c88
SP
1402 unsigned char *base;
1403 unsigned int left;
ad1ed5ee 1404 unsigned long used;
2b87c45b 1405 enum object_type type;
a733cb60 1406
8d8a4ea5
SP
1407 /* use_pack() assures us we have [base, base + 20) available
1408 * as a range that we can look at at. (Its actually the hash
3dff5379 1409 * size that is assured.) With our object header encoding
8d8a4ea5
SP
1410 * the maximum deflated object size is 2^137, which is just
1411 * insane, so we know won't exceed what we have been given.
1412 */
2b87c45b 1413 base = use_pack(p, w_curs, *curpos, &left);
09ded04b
NP
1414 used = unpack_object_header_buffer(base, left, &type, sizep);
1415 if (!used) {
1416 type = OBJ_BAD;
1417 } else
1418 *curpos += used;
ad1ed5ee 1419
2b87c45b 1420 return type;
a733cb60
LT
1421}
1422
21666f1a 1423const char *packed_object_info_detail(struct packed_git *p,
c4001d92 1424 off_t obj_offset,
21666f1a
NP
1425 unsigned long *size,
1426 unsigned long *store_size,
1427 unsigned int *delta_chain_length,
1428 unsigned char *base_sha1)
ad8c80a5 1429{
03e79c88 1430 struct pack_window *w_curs = NULL;
c4001d92
SP
1431 off_t curpos;
1432 unsigned long dummy;
43057304 1433 unsigned char *next_sha1;
21666f1a 1434 enum object_type type;
70f5d5d3 1435 struct revindex_entry *revidx;
ad8c80a5 1436
43057304 1437 *delta_chain_length = 0;
2b87c45b 1438 curpos = obj_offset;
21666f1a 1439 type = unpack_object_header(p, &w_curs, &curpos, size);
43057304 1440
70f5d5d3
NP
1441 revidx = find_pack_revindex(p, obj_offset);
1442 *store_size = revidx[1].offset - obj_offset;
1443
43057304 1444 for (;;) {
21666f1a 1445 switch (type) {
43057304 1446 default:
08a19d87 1447 die("pack %s contains unknown object type %d",
21666f1a 1448 p->pack_name, type);
43057304
NP
1449 case OBJ_COMMIT:
1450 case OBJ_TREE:
1451 case OBJ_BLOB:
1452 case OBJ_TAG:
03e79c88 1453 unuse_pack(&w_curs);
21666f1a 1454 return typename(type);
eb32d236 1455 case OBJ_OFS_DELTA:
21666f1a 1456 obj_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset);
8eca0b47
NP
1457 if (!obj_offset)
1458 die("pack %s contains bad delta base reference of type %s",
1459 p->pack_name, typename(type));
eb32d236 1460 if (*delta_chain_length == 0) {
70f5d5d3
NP
1461 revidx = find_pack_revindex(p, obj_offset);
1462 hashcpy(base_sha1, nth_packed_object_sha1(p, revidx->nr));
eb32d236
NP
1463 }
1464 break;
1465 case OBJ_REF_DELTA:
2b87c45b 1466 next_sha1 = use_pack(p, &w_curs, curpos, NULL);
43057304
NP
1467 if (*delta_chain_length == 0)
1468 hashcpy(base_sha1, next_sha1);
2b87c45b 1469 obj_offset = find_pack_entry_one(next_sha1, p);
43057304
NP
1470 break;
1471 }
43057304 1472 (*delta_chain_length)++;
2b87c45b 1473 curpos = obj_offset;
21666f1a 1474 type = unpack_object_header(p, &w_curs, &curpos, &dummy);
ad8c80a5 1475 }
ad8c80a5
JH
1476}
1477
c4001d92 1478static int packed_object_info(struct packed_git *p, off_t obj_offset,
21666f1a 1479 unsigned long *sizep)
1f688557 1480{
03e79c88 1481 struct pack_window *w_curs = NULL;
c4001d92
SP
1482 unsigned long size;
1483 off_t curpos = obj_offset;
21666f1a 1484 enum object_type type;
5db47c2b 1485
21666f1a 1486 type = unpack_object_header(p, &w_curs, &curpos, &size);
5db47c2b 1487
21666f1a 1488 switch (type) {
eb32d236
NP
1489 case OBJ_OFS_DELTA:
1490 case OBJ_REF_DELTA:
21666f1a
NP
1491 type = packed_delta_info(p, &w_curs, curpos,
1492 type, obj_offset, sizep);
2b87c45b 1493 break;
a733cb60 1494 case OBJ_COMMIT:
a733cb60 1495 case OBJ_TREE:
a733cb60 1496 case OBJ_BLOB:
a733cb60 1497 case OBJ_TAG:
2b87c45b
NP
1498 if (sizep)
1499 *sizep = size;
a69d0943 1500 break;
1f688557 1501 default:
3d77d877
NP
1502 error("unknown object type %i at offset %"PRIuMAX" in %s",
1503 type, (uintmax_t)obj_offset, p->pack_name);
1504 type = OBJ_BAD;
1f688557 1505 }
2b87c45b 1506 unuse_pack(&w_curs);
21666f1a 1507 return type;
1f688557
JH
1508}
1509
eb950c19 1510static void *unpack_compressed_entry(struct packed_git *p,
03e79c88 1511 struct pack_window **w_curs,
c4001d92 1512 off_t curpos,
eb950c19 1513 unsigned long size)
de530aaa
SP
1514{
1515 int st;
1516 z_stream stream;
079afb18 1517 unsigned char *buffer, *in;
de530aaa 1518
4ab07e4d 1519 buffer = xmallocz(size);
de530aaa 1520 memset(&stream, 0, sizeof(stream));
de530aaa 1521 stream.next_out = buffer;
39eea7bd 1522 stream.avail_out = size + 1;
de530aaa 1523
39c68542 1524 git_inflate_init(&stream);
079afb18 1525 do {
2b87c45b 1526 in = use_pack(p, w_curs, curpos, &stream.avail_in);
079afb18 1527 stream.next_in = in;
39c68542 1528 st = git_inflate(&stream, Z_FINISH);
39eea7bd
JH
1529 if (!stream.avail_out)
1530 break; /* the payload is larger than it should be */
2b87c45b 1531 curpos += stream.next_in - in;
079afb18 1532 } while (st == Z_OK || st == Z_BUF_ERROR);
39c68542 1533 git_inflate_end(&stream);
de530aaa
SP
1534 if ((st != Z_STREAM_END) || stream.total_out != size) {
1535 free(buffer);
1536 return NULL;
1537 }
1538
1539 return buffer;
1540}
1541
e5e01619
LT
1542#define MAX_DELTA_CACHE (256)
1543
18bdec11 1544static size_t delta_base_cached;
5e08ecbf
NP
1545
1546static struct delta_base_cache_lru_list {
1547 struct delta_base_cache_lru_list *prev;
1548 struct delta_base_cache_lru_list *next;
1549} delta_base_cache_lru = { &delta_base_cache_lru, &delta_base_cache_lru };
1550
e5e01619 1551static struct delta_base_cache_entry {
5e08ecbf
NP
1552 struct delta_base_cache_lru_list lru;
1553 void *data;
e5e01619
LT
1554 struct packed_git *p;
1555 off_t base_offset;
1556 unsigned long size;
e5e01619
LT
1557 enum object_type type;
1558} delta_base_cache[MAX_DELTA_CACHE];
1559
1560static unsigned long pack_entry_hash(struct packed_git *p, off_t base_offset)
1561{
1562 unsigned long hash;
1563
1564 hash = (unsigned long)p + (unsigned long)base_offset;
1565 hash += (hash >> 8) + (hash >> 16);
3358004a 1566 return hash % MAX_DELTA_CACHE;
e5e01619
LT
1567}
1568
62f255ad 1569static void *cache_or_unpack_entry(struct packed_git *p, off_t base_offset,
a0cba108 1570 unsigned long *base_size, enum object_type *type, int keep_cache)
62f255ad 1571{
e5e01619
LT
1572 void *ret;
1573 unsigned long hash = pack_entry_hash(p, base_offset);
1574 struct delta_base_cache_entry *ent = delta_base_cache + hash;
1575
1576 ret = ent->data;
749bc58c
MV
1577 if (!ret || ent->p != p || ent->base_offset != base_offset)
1578 return unpack_entry(p, base_offset, type, base_size);
e5e01619 1579
18bdec11 1580 if (!keep_cache) {
a0cba108 1581 ent->data = NULL;
5e08ecbf
NP
1582 ent->lru.next->prev = ent->lru.prev;
1583 ent->lru.prev->next = ent->lru.next;
18bdec11 1584 delta_base_cached -= ent->size;
182af834
PH
1585 } else {
1586 ret = xmemdupz(ent->data, ent->size);
a0cba108 1587 }
e5e01619
LT
1588 *type = ent->type;
1589 *base_size = ent->size;
1590 return ret;
62f255ad
LT
1591}
1592
18bdec11
SP
1593static inline void release_delta_base_cache(struct delta_base_cache_entry *ent)
1594{
1595 if (ent->data) {
1596 free(ent->data);
1597 ent->data = NULL;
5e08ecbf
NP
1598 ent->lru.next->prev = ent->lru.prev;
1599 ent->lru.prev->next = ent->lru.next;
18bdec11
SP
1600 delta_base_cached -= ent->size;
1601 }
1602}
1603
3d20c636
SP
1604void clear_delta_base_cache(void)
1605{
1606 unsigned long p;
1607 for (p = 0; p < MAX_DELTA_CACHE; p++)
1608 release_delta_base_cache(&delta_base_cache[p]);
1609}
1610
62f255ad
LT
1611static void add_delta_base_cache(struct packed_git *p, off_t base_offset,
1612 void *base, unsigned long base_size, enum object_type type)
1613{
5e08ecbf 1614 unsigned long hash = pack_entry_hash(p, base_offset);
e5e01619 1615 struct delta_base_cache_entry *ent = delta_base_cache + hash;
5e08ecbf 1616 struct delta_base_cache_lru_list *lru;
e5e01619 1617
18bdec11
SP
1618 release_delta_base_cache(ent);
1619 delta_base_cached += base_size;
5e08ecbf
NP
1620
1621 for (lru = delta_base_cache_lru.next;
1622 delta_base_cached > delta_base_cache_limit
1623 && lru != &delta_base_cache_lru;
1624 lru = lru->next) {
1625 struct delta_base_cache_entry *f = (void *)lru;
18bdec11
SP
1626 if (f->type == OBJ_BLOB)
1627 release_delta_base_cache(f);
1628 }
5e08ecbf
NP
1629 for (lru = delta_base_cache_lru.next;
1630 delta_base_cached > delta_base_cache_limit
1631 && lru != &delta_base_cache_lru;
1632 lru = lru->next) {
1633 struct delta_base_cache_entry *f = (void *)lru;
1634 release_delta_base_cache(f);
1635 }
18bdec11 1636
e5e01619
LT
1637 ent->p = p;
1638 ent->base_offset = base_offset;
1639 ent->type = type;
1640 ent->data = base;
1641 ent->size = base_size;
5e08ecbf
NP
1642 ent->lru.next = &delta_base_cache_lru;
1643 ent->lru.prev = delta_base_cache_lru.prev;
1644 delta_base_cache_lru.prev->next = &ent->lru;
1645 delta_base_cache_lru.prev = &ent->lru;
62f255ad
LT
1646}
1647
c2c5b270
CC
1648static void *read_object(const unsigned char *sha1, enum object_type *type,
1649 unsigned long *size);
1650
eb950c19 1651static void *unpack_delta_entry(struct packed_git *p,
03e79c88 1652 struct pack_window **w_curs,
c4001d92 1653 off_t curpos,
1f688557 1654 unsigned long delta_size,
c4001d92 1655 off_t obj_offset,
21666f1a 1656 enum object_type *type,
eb950c19 1657 unsigned long *sizep)
1f688557 1658{
7c3e8be3 1659 void *delta_data, *result, *base;
c4001d92
SP
1660 unsigned long base_size;
1661 off_t base_offset;
43057304 1662
21666f1a 1663 base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
8eca0b47
NP
1664 if (!base_offset) {
1665 error("failed to validate delta base reference "
1666 "at offset %"PRIuMAX" from %s",
1667 (uintmax_t)curpos, p->pack_name);
1668 return NULL;
1669 }
eac12e2d 1670 unuse_pack(w_curs);
a0cba108 1671 base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
8eca0b47
NP
1672 if (!base) {
1673 /*
1674 * We're probably in deep shit, but let's try to fetch
1675 * the required base anyway from another pack or loose.
1676 * This is costly but should happen only in the presence
1677 * of a corrupted pack, and is better than failing outright.
1678 */
08698b1e
NP
1679 struct revindex_entry *revidx;
1680 const unsigned char *base_sha1;
1681 revidx = find_pack_revindex(p, base_offset);
1682 if (!revidx)
1683 return NULL;
1684 base_sha1 = nth_packed_object_sha1(p, revidx->nr);
8eca0b47
NP
1685 error("failed to read delta base object %s"
1686 " at offset %"PRIuMAX" from %s",
1687 sha1_to_hex(base_sha1), (uintmax_t)base_offset,
1688 p->pack_name);
1689 mark_bad_packed_object(p, base_sha1);
ac939109 1690 base = read_object(base_sha1, type, &base_size);
8eca0b47
NP
1691 if (!base)
1692 return NULL;
1693 }
67686d95 1694
2b87c45b 1695 delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
8eca0b47
NP
1696 if (!delta_data) {
1697 error("failed to unpack compressed delta "
1698 "at offset %"PRIuMAX" from %s",
1699 (uintmax_t)curpos, p->pack_name);
1700 free(base);
1701 return NULL;
1702 }
1f688557
JH
1703 result = patch_delta(base, base_size,
1704 delta_data, delta_size,
21666f1a 1705 sizep);
1f688557
JH
1706 if (!result)
1707 die("failed to apply delta");
1708 free(delta_data);
62f255ad 1709 add_delta_base_cache(p, base_offset, base, base_size, *type);
1f688557
JH
1710 return result;
1711}
1712
0e8189e2
NP
1713int do_check_packed_object_crc;
1714
c4001d92 1715void *unpack_entry(struct packed_git *p, off_t obj_offset,
21666f1a 1716 enum object_type *type, unsigned long *sizep)
1f688557 1717{
03e79c88 1718 struct pack_window *w_curs = NULL;
c4001d92 1719 off_t curpos = obj_offset;
21666f1a 1720 void *data;
1f688557 1721
0e8189e2
NP
1722 if (do_check_packed_object_crc && p->index_version > 1) {
1723 struct revindex_entry *revidx = find_pack_revindex(p, obj_offset);
1724 unsigned long len = revidx[1].offset - obj_offset;
1725 if (check_pack_crc(p, &w_curs, obj_offset, len, revidx->nr)) {
1726 const unsigned char *sha1 =
1727 nth_packed_object_sha1(p, revidx->nr);
1728 error("bad packed object CRC for %s",
1729 sha1_to_hex(sha1));
1730 mark_bad_packed_object(p, sha1);
f755bb99 1731 unuse_pack(&w_curs);
0e8189e2
NP
1732 return NULL;
1733 }
1734 }
1735
21666f1a
NP
1736 *type = unpack_object_header(p, &w_curs, &curpos, sizep);
1737 switch (*type) {
eb32d236
NP
1738 case OBJ_OFS_DELTA:
1739 case OBJ_REF_DELTA:
21666f1a
NP
1740 data = unpack_delta_entry(p, &w_curs, curpos, *sizep,
1741 obj_offset, type, sizep);
4d703a1a 1742 break;
a733cb60 1743 case OBJ_COMMIT:
a733cb60 1744 case OBJ_TREE:
a733cb60 1745 case OBJ_BLOB:
a733cb60 1746 case OBJ_TAG:
21666f1a 1747 data = unpack_compressed_entry(p, &w_curs, curpos, *sizep);
4d703a1a 1748 break;
1f688557 1749 default:
8eca0b47
NP
1750 data = NULL;
1751 error("unknown object type %i at offset %"PRIuMAX" in %s",
1752 *type, (uintmax_t)obj_offset, p->pack_name);
1f688557 1753 }
03e79c88 1754 unuse_pack(&w_curs);
21666f1a 1755 return data;
1f688557
JH
1756}
1757
d079837e 1758const unsigned char *nth_packed_object_sha1(struct packed_git *p,
d72308e0 1759 uint32_t n)
9a217f2a 1760{
42873078 1761 const unsigned char *index = p->index_data;
d079837e
SP
1762 if (!index) {
1763 if (open_pack_index(p))
1764 return NULL;
1765 index = p->index_data;
1766 }
57059091 1767 if (n >= p->num_objects)
d72308e0 1768 return NULL;
74e34e1f
NP
1769 index += 4 * 256;
1770 if (p->index_version == 1) {
1771 return index + 24 * n + 4;
1772 } else {
1773 index += 8;
1774 return index + 20 * n;
1775 }
1776}
1777
99093238 1778off_t nth_packed_object_offset(const struct packed_git *p, uint32_t n)
74e34e1f
NP
1779{
1780 const unsigned char *index = p->index_data;
1781 index += 4 * 256;
1782 if (p->index_version == 1) {
1783 return ntohl(*((uint32_t *)(index + 24 * n)));
1784 } else {
1785 uint32_t off;
1786 index += 8 + p->num_objects * (20 + 4);
1787 off = ntohl(*((uint32_t *)(index + 4 * n)));
1788 if (!(off & 0x80000000))
1789 return off;
1790 index += p->num_objects * 4 + (off & 0x7fffffff) * 8;
1791 return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) |
1792 ntohl(*((uint32_t *)(index + 4)));
1793 }
9a217f2a
JH
1794}
1795
c4001d92 1796off_t find_pack_entry_one(const unsigned char *sha1,
43057304 1797 struct packed_git *p)
1f688557 1798{
42873078 1799 const uint32_t *level1_ofs = p->index_data;
42873078 1800 const unsigned char *index = p->index_data;
628522ec
JH
1801 unsigned hi, lo, stride;
1802 static int use_lookup = -1;
1803 static int debug_lookup = -1;
1804
1805 if (debug_lookup < 0)
1806 debug_lookup = !!getenv("GIT_DEBUG_LOOKUP");
42873078 1807
d079837e
SP
1808 if (!index) {
1809 if (open_pack_index(p))
1810 return 0;
1811 level1_ofs = p->index_data;
1812 index = p->index_data;
1813 }
74e34e1f
NP
1814 if (p->index_version > 1) {
1815 level1_ofs += 2;
1816 index += 8;
1817 }
42873078 1818 index += 4 * 256;
74e34e1f
NP
1819 hi = ntohl(level1_ofs[*sha1]);
1820 lo = ((*sha1 == 0x0) ? 0 : ntohl(level1_ofs[*sha1 - 1]));
628522ec
JH
1821 if (p->index_version > 1) {
1822 stride = 20;
1823 } else {
1824 stride = 24;
1825 index += 4;
1826 }
1827
1828 if (debug_lookup)
6e1c2344 1829 printf("%02x%02x%02x... lo %u hi %u nr %"PRIu32"\n",
628522ec
JH
1830 sha1[0], sha1[1], sha1[2], lo, hi, p->num_objects);
1831
1832 if (use_lookup < 0)
1833 use_lookup = !!getenv("GIT_USE_LOOKUP");
1834 if (use_lookup) {
1835 int pos = sha1_entry_pos(index, stride, 0,
1836 lo, hi, p->num_objects, sha1);
1837 if (pos < 0)
1838 return 0;
1839 return nth_packed_object_offset(p, pos);
1840 }
1f688557
JH
1841
1842 do {
74e34e1f 1843 unsigned mi = (lo + hi) / 2;
628522ec
JH
1844 int cmp = hashcmp(index + mi * stride, sha1);
1845
1846 if (debug_lookup)
1847 printf("lo %u hi %u rg %u mi %u\n",
1848 lo, hi, hi - lo, mi);
43057304 1849 if (!cmp)
74e34e1f 1850 return nth_packed_object_offset(p, mi);
1f688557
JH
1851 if (cmp > 0)
1852 hi = mi;
1853 else
1854 lo = mi+1;
1855 } while (lo < hi);
1856 return 0;
1857}
1858
4d6acb70 1859static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e)
1f688557 1860{
f7c22cc6 1861 static struct packed_git *last_found = (void *)1;
1f688557 1862 struct packed_git *p;
c4001d92 1863 off_t offset;
43057304 1864
1f688557 1865 prepare_packed_git();
f7c22cc6
NP
1866 if (!packed_git)
1867 return 0;
1868 p = (last_found == (void *)1) ? packed_git : last_found;
1f688557 1869
f7c22cc6 1870 do {
8eca0b47
NP
1871 if (p->num_bad_objects) {
1872 unsigned i;
1873 for (i = 0; i < p->num_bad_objects; i++)
1874 if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i))
1875 goto next;
1876 }
1877
43057304
NP
1878 offset = find_pack_entry_one(sha1, p);
1879 if (offset) {
c715f783
SP
1880 /*
1881 * We are about to tell the caller where they can
1882 * locate the requested object. We better make
1883 * sure the packfile is still here and can be
1884 * accessed before supplying that answer, as
1885 * it may have been deleted since the index
1886 * was loaded!
1887 */
1888 if (p->pack_fd == -1 && open_packed_git(p)) {
1889 error("packfile %s cannot be accessed", p->pack_name);
f7c22cc6 1890 goto next;
c715f783 1891 }
43057304
NP
1892 e->offset = offset;
1893 e->p = p;
1894 hashcpy(e->sha1, sha1);
f7c22cc6 1895 last_found = p;
1f688557 1896 return 1;
43057304 1897 }
f7c22cc6
NP
1898
1899 next:
1900 if (p == last_found)
1901 p = packed_git;
1902 else
1903 p = p->next;
1904 if (p == last_found)
1905 p = p->next;
1906 } while (p);
1f688557
JH
1907 return 0;
1908}
1909
a6080a0a 1910struct packed_git *find_sha1_pack(const unsigned char *sha1,
bf592c50
DB
1911 struct packed_git *packs)
1912{
1913 struct packed_git *p;
bf592c50
DB
1914
1915 for (p = packs; p; p = p->next) {
43057304 1916 if (find_pack_entry_one(sha1, p))
bf592c50
DB
1917 return p;
1918 }
1919 return NULL;
21666f1a 1920
bf592c50
DB
1921}
1922
21666f1a 1923static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *sizep)
65c2e0c3 1924{
36e4d74a 1925 int status;
65c2e0c3
JH
1926 unsigned long mapsize, size;
1927 void *map;
1928 z_stream stream;
d65a16f6 1929 char hdr[32];
65c2e0c3 1930
bb6b8e4f 1931 map = map_sha1_file(sha1, &mapsize);
f0df4ed5
JS
1932 if (!map)
1933 return error("unable to find %s", sha1_to_hex(sha1));
36e4d74a
JH
1934 if (unpack_sha1_header(&stream, map, mapsize, hdr, sizeof(hdr)) < 0)
1935 status = error("unable to unpack %s header",
1936 sha1_to_hex(sha1));
21666f1a 1937 else if ((status = parse_sha1_header(hdr, &size)) < 0)
36e4d74a 1938 status = error("unable to parse %s header", sha1_to_hex(sha1));
21666f1a
NP
1939 else if (sizep)
1940 *sizep = size;
39c68542 1941 git_inflate_end(&stream);
65c2e0c3
JH
1942 munmap(map, mapsize);
1943 return status;
1944}
1945
21666f1a 1946int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
f0df4ed5 1947{
f0df4ed5 1948 struct pack_entry e;
ddd63e64 1949 int status;
f0df4ed5 1950
cd673c1f 1951 if (!find_pack_entry(sha1, &e)) {
ddd63e64
SG
1952 /* Most likely it's a loose object. */
1953 status = sha1_loose_object_info(sha1, sizep);
1954 if (status >= 0)
1955 return status;
1956
1957 /* Not a loose object; someone else may have just packed it. */
f0df4ed5 1958 reprepare_packed_git();
cd673c1f 1959 if (!find_pack_entry(sha1, &e))
ddd63e64 1960 return status;
f0df4ed5 1961 }
3d77d877
NP
1962
1963 status = packed_object_info(e.p, e.offset, sizep);
1964 if (status < 0) {
1965 mark_bad_packed_object(e.p, sha1);
1966 status = sha1_object_info(sha1, sizep);
1967 }
1968
1969 return status;
f0df4ed5
JS
1970}
1971
21666f1a
NP
1972static void *read_packed_sha1(const unsigned char *sha1,
1973 enum object_type *type, unsigned long *size)
1f688557
JH
1974{
1975 struct pack_entry e;
8eca0b47 1976 void *data;
1f688557 1977
cd673c1f 1978 if (!find_pack_entry(sha1, &e))
1f688557 1979 return NULL;
8eca0b47
NP
1980 data = cache_or_unpack_entry(e.p, e.offset, size, type, 1);
1981 if (!data) {
1982 /*
1983 * We're probably in deep shit, but let's try to fetch
1984 * the required object anyway from another pack or loose.
1985 * This should happen only in the presence of a corrupted
1986 * pack, and is better than failing outright.
1987 */
1988 error("failed to read object %s at offset %"PRIuMAX" from %s",
1989 sha1_to_hex(sha1), (uintmax_t)e.offset, e.p->pack_name);
1990 mark_bad_packed_object(e.p, sha1);
ac939109 1991 data = read_object(sha1, type, size);
8eca0b47
NP
1992 }
1993 return data;
1f688557
JH
1994}
1995
d66b37bb
JH
1996/*
1997 * This is meant to hold a *small* number of objects that you would
1998 * want read_sha1_file() to be able to return, but yet you do not want
1999 * to write them into the object store (e.g. a browse-only
2000 * application).
2001 */
2002static struct cached_object {
2003 unsigned char sha1[20];
21666f1a 2004 enum object_type type;
d66b37bb
JH
2005 void *buf;
2006 unsigned long size;
2007} *cached_objects;
2008static int cached_object_nr, cached_object_alloc;
2009
346245a1 2010static struct cached_object empty_tree = {
14d9c578 2011 EMPTY_TREE_SHA1_BIN,
346245a1
JK
2012 OBJ_TREE,
2013 "",
2014 0
2015};
2016
d66b37bb
JH
2017static struct cached_object *find_cached_object(const unsigned char *sha1)
2018{
2019 int i;
2020 struct cached_object *co = cached_objects;
2021
2022 for (i = 0; i < cached_object_nr; i++, co++) {
2023 if (!hashcmp(co->sha1, sha1))
2024 return co;
2025 }
346245a1
JK
2026 if (!hashcmp(sha1, empty_tree.sha1))
2027 return &empty_tree;
d66b37bb
JH
2028 return NULL;
2029}
2030
21666f1a
NP
2031int pretend_sha1_file(void *buf, unsigned long len, enum object_type type,
2032 unsigned char *sha1)
d66b37bb
JH
2033{
2034 struct cached_object *co;
2035
21666f1a 2036 hash_sha1_file(buf, len, typename(type), sha1);
d66b37bb
JH
2037 if (has_sha1_file(sha1) || find_cached_object(sha1))
2038 return 0;
2039 if (cached_object_alloc <= cached_object_nr) {
2040 cached_object_alloc = alloc_nr(cached_object_alloc);
2041 cached_objects = xrealloc(cached_objects,
2042 sizeof(*cached_objects) *
2043 cached_object_alloc);
2044 }
2045 co = &cached_objects[cached_object_nr++];
2046 co->size = len;
21666f1a 2047 co->type = type;
efa13f7b
JH
2048 co->buf = xmalloc(len);
2049 memcpy(co->buf, buf, len);
d66b37bb
JH
2050 hashcpy(co->sha1, sha1);
2051 return 0;
2052}
2053
c2c5b270
CC
2054static void *read_object(const unsigned char *sha1, enum object_type *type,
2055 unsigned long *size)
0fcfd160
LT
2056{
2057 unsigned long mapsize;
2058 void *map, *buf;
d66b37bb
JH
2059 struct cached_object *co;
2060
2061 co = find_cached_object(sha1);
2062 if (co) {
21666f1a 2063 *type = co->type;
d66b37bb 2064 *size = co->size;
182af834 2065 return xmemdupz(co->buf, co->size);
d66b37bb 2066 }
0fcfd160 2067
8276c007
PE
2068 buf = read_packed_sha1(sha1, type, size);
2069 if (buf)
2070 return buf;
bb6b8e4f 2071 map = map_sha1_file(sha1, &mapsize);
0fcfd160 2072 if (map) {
7efbff75 2073 buf = unpack_sha1_file(map, mapsize, type, size, sha1);
0fcfd160
LT
2074 munmap(map, mapsize);
2075 return buf;
2076 }
637cdd9d 2077 reprepare_packed_git();
8276c007 2078 return read_packed_sha1(sha1, type, size);
0fcfd160
LT
2079}
2080
f5552aee
CC
2081void *read_sha1_file_repl(const unsigned char *sha1,
2082 enum object_type *type,
2083 unsigned long *size,
2084 const unsigned char **replacement)
ac939109 2085{
68095570
CC
2086 const unsigned char *repl = lookup_replace_object(sha1);
2087 void *data = read_object(repl, type, size);
2088
2089 /* die if we replaced an object with one that does not exist */
2090 if (!data && repl != sha1)
2091 die("replacement %s not found for %s",
2092 sha1_to_hex(repl), sha1_to_hex(sha1));
2093
ac939109 2094 /* legacy behavior is to die on corrupted objects */
68095570
CC
2095 if (!data && (has_loose_object(repl) || has_packed_and_bad(repl)))
2096 die("object %s is corrupted", sha1_to_hex(repl));
2097
f5552aee
CC
2098 if (replacement)
2099 *replacement = repl;
2100
ac939109
NP
2101 return data;
2102}
2103
40469ee9 2104void *read_object_with_reference(const unsigned char *sha1,
21666f1a 2105 const char *required_type_name,
40469ee9
JH
2106 unsigned long *size,
2107 unsigned char *actual_sha1_return)
f4913f91 2108{
21666f1a 2109 enum object_type type, required_type;
f4913f91
JH
2110 void *buffer;
2111 unsigned long isize;
40469ee9 2112 unsigned char actual_sha1[20];
f4913f91 2113
21666f1a 2114 required_type = type_from_string(required_type_name);
e702496e 2115 hashcpy(actual_sha1, sha1);
40469ee9
JH
2116 while (1) {
2117 int ref_length = -1;
2118 const char *ref_type = NULL;
f4913f91 2119
21666f1a 2120 buffer = read_sha1_file(actual_sha1, &type, &isize);
40469ee9
JH
2121 if (!buffer)
2122 return NULL;
21666f1a 2123 if (type == required_type) {
40469ee9
JH
2124 *size = isize;
2125 if (actual_sha1_return)
e702496e 2126 hashcpy(actual_sha1_return, actual_sha1);
40469ee9
JH
2127 return buffer;
2128 }
2129 /* Handle references */
21666f1a 2130 else if (type == OBJ_COMMIT)
40469ee9 2131 ref_type = "tree ";
21666f1a 2132 else if (type == OBJ_TAG)
40469ee9
JH
2133 ref_type = "object ";
2134 else {
2135 free(buffer);
2136 return NULL;
2137 }
2138 ref_length = strlen(ref_type);
f4913f91 2139
50974ec9
MK
2140 if (ref_length + 40 > isize ||
2141 memcmp(buffer, ref_type, ref_length) ||
1d7f171c 2142 get_sha1_hex((char *) buffer + ref_length, actual_sha1)) {
40469ee9
JH
2143 free(buffer);
2144 return NULL;
2145 }
1cf58e72 2146 free(buffer);
40469ee9
JH
2147 /* Now we have the ID of the referred-to object in
2148 * actual_sha1. Check again. */
f4913f91 2149 }
f4913f91
JH
2150}
2151
ce9fbf16 2152static void write_sha1_file_prepare(const void *buf, unsigned long len,
972a9155 2153 const char *type, unsigned char *sha1,
d65a16f6 2154 char *hdr, int *hdrlen)
d410c0f5 2155{
9126f009 2156 git_SHA_CTX c;
d410c0f5
JH
2157
2158 /* Generate the header */
d65a16f6 2159 *hdrlen = sprintf(hdr, "%s %lu", type, len)+1;
d410c0f5
JH
2160
2161 /* Sha1.. */
9126f009
NP
2162 git_SHA1_Init(&c);
2163 git_SHA1_Update(&c, hdr, *hdrlen);
2164 git_SHA1_Update(&c, buf, len);
2165 git_SHA1_Final(sha1, &c);
d410c0f5
JH
2166}
2167
230f1322 2168/*
5a688fe4
JH
2169 * Move the just written object into its final resting place.
2170 * NEEDSWORK: this should be renamed to finalize_temp_file() as
2171 * "moving" is only a part of what it does, when no patch between
2172 * master to pu changes the call sites of this function.
230f1322 2173 */
839837b9 2174int move_temp_to_file(const char *tmpfile, const char *filename)
230f1322 2175{
e32c0a9c 2176 int ret = 0;
5a688fe4 2177
348df166 2178 if (object_creation_mode == OBJECT_CREATION_USES_RENAMES)
be66a6c4
JS
2179 goto try_rename;
2180 else if (link(tmpfile, filename))
e32c0a9c 2181 ret = errno;
7ebb6fca
LT
2182
2183 /*
2184 * Coda hack - coda doesn't like cross-directory links,
2185 * so we fall back to a rename, which will mean that it
2186 * won't be able to check collisions, but that's not a
2187 * big deal.
2188 *
2189 * The same holds for FAT formatted media.
2190 *
3be1f18e 2191 * When this succeeds, we just return. We have nothing
7ebb6fca
LT
2192 * left to unlink.
2193 */
2194 if (ret && ret != EEXIST) {
be66a6c4 2195 try_rename:
7ebb6fca 2196 if (!rename(tmpfile, filename))
3be1f18e 2197 goto out;
9e48b389 2198 ret = errno;
230f1322 2199 }
691f1a28 2200 unlink_or_warn(tmpfile);
230f1322
LT
2201 if (ret) {
2202 if (ret != EEXIST) {
916d081b 2203 return error("unable to write sha1 filename %s: %s\n", filename, strerror(ret));
230f1322
LT
2204 }
2205 /* FIXME!!! Collision check here ? */
2206 }
2207
3be1f18e 2208out:
5256b006 2209 if (adjust_shared_perm(filename))
5a688fe4 2210 return error("unable to set permission to '%s'", filename);
230f1322
LT
2211 return 0;
2212}
2213
4d548150
LT
2214static int write_buffer(int fd, const void *buf, size_t len)
2215{
d34cf19b 2216 if (write_in_full(fd, buf, len) < 0)
93822c22 2217 return error("file write error (%s)", strerror(errno));
4d548150
LT
2218 return 0;
2219}
2220
ce9fbf16 2221int hash_sha1_file(const void *buf, unsigned long len, const char *type,
abdc3fc8
RS
2222 unsigned char *sha1)
2223{
d65a16f6 2224 char hdr[32];
abdc3fc8
RS
2225 int hdrlen;
2226 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2227 return 0;
2228}
2229
e9039dd3
LT
2230/* Finalize a file on disk, and close it. */
2231static void close_sha1_file(int fd)
2232{
aafe9fba
LT
2233 if (fsync_object_files)
2234 fsync_or_die(fd, "sha1 file");
e9039dd3 2235 if (close(fd) != 0)
d824cbba 2236 die_errno("error when closing sha1 file");
e9039dd3
LT
2237}
2238
5723fe7e
LT
2239/* Size of directory component, including the ending '/' */
2240static inline int directory_size(const char *filename)
2241{
2242 const char *s = strrchr(filename, '/');
2243 if (!s)
2244 return 0;
2245 return s - filename + 1;
2246}
2247
2248/*
2249 * This creates a temporary file in the same directory as the final
2250 * 'filename'
2251 *
2252 * We want to avoid cross-directory filename renames, because those
2253 * can have problems on various filesystems (FAT, NFS, Coda).
2254 */
2255static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
2256{
2257 int fd, dirlen = directory_size(filename);
2258
2259 if (dirlen + 20 > bufsiz) {
2260 errno = ENAMETOOLONG;
2261 return -1;
2262 }
2263 memcpy(buffer, filename, dirlen);
2264 strcpy(buffer + dirlen, "tmp_obj_XXXXXX");
5256b006 2265 fd = git_mkstemp_mode(buffer, 0444);
cbacbf4e 2266 if (fd < 0 && dirlen && errno == ENOENT) {
5723fe7e 2267 /* Make sure the directory exists */
6ff6af62 2268 memcpy(buffer, filename, dirlen);
5723fe7e 2269 buffer[dirlen-1] = 0;
3bfaf018 2270 if (mkdir(buffer, 0777) || adjust_shared_perm(buffer))
5723fe7e
LT
2271 return -1;
2272
2273 /* Try again */
2274 strcpy(buffer + dirlen - 1, "/tmp_obj_XXXXXX");
5256b006 2275 fd = git_mkstemp_mode(buffer, 0444);
5723fe7e
LT
2276 }
2277 return fd;
2278}
2279
bbac7311
NP
2280static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
2281 void *buf, unsigned long len, time_t mtime)
0fcfd160 2282{
915308b1 2283 int fd, ret;
9892beba 2284 unsigned char compressed[4096];
0fcfd160 2285 z_stream stream;
748af44c
NP
2286 git_SHA_CTX c;
2287 unsigned char parano_sha1[20];
706bc531 2288 char *filename;
aac17941 2289 static char tmpfile[PATH_MAX];
a44c9a5e 2290
972a9155 2291 filename = sha1_file_name(sha1);
5723fe7e 2292 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
fd73ccf2
JS
2293 while (fd < 0 && errno == EMFILE && unuse_one_window(packed_git, -1))
2294 fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename);
aac17941 2295 if (fd < 0) {
35243577 2296 if (errno == EACCES)
916d081b
PB
2297 return error("insufficient permission for adding an object to repository database %s\n", get_object_directory());
2298 else
2299 return error("unable to create temporary sha1 filename %s: %s\n", tmpfile, strerror(errno));
aac17941
LT
2300 }
2301
0fcfd160
LT
2302 /* Set it up */
2303 memset(&stream, 0, sizeof(stream));
12f6c308 2304 deflateInit(&stream, zlib_compression_level);
0fcfd160 2305 stream.next_out = compressed;
9892beba 2306 stream.avail_out = sizeof(compressed);
748af44c 2307 git_SHA1_Init(&c);
a44c9a5e
LT
2308
2309 /* First header.. */
d65a16f6 2310 stream.next_in = (unsigned char *)hdr;
a44c9a5e 2311 stream.avail_in = hdrlen;
726f852b
NP
2312 while (deflate(&stream, 0) == Z_OK)
2313 /* nothing */;
748af44c 2314 git_SHA1_Update(&c, hdr, hdrlen);
a44c9a5e
LT
2315
2316 /* Then the data itself.. */
2317 stream.next_in = buf;
2318 stream.avail_in = len;
9892beba 2319 do {
748af44c 2320 unsigned char *in0 = stream.next_in;
9892beba 2321 ret = deflate(&stream, Z_FINISH);
748af44c 2322 git_SHA1_Update(&c, in0, stream.next_in - in0);
9892beba
NP
2323 if (write_buffer(fd, compressed, stream.next_out - compressed) < 0)
2324 die("unable to write sha1 file");
2325 stream.next_out = compressed;
2326 stream.avail_out = sizeof(compressed);
2327 } while (ret == Z_OK);
2328
ac54c277
LT
2329 if (ret != Z_STREAM_END)
2330 die("unable to deflate new object %s (%d)", sha1_to_hex(sha1), ret);
ac54c277
LT
2331 ret = deflateEnd(&stream);
2332 if (ret != Z_OK)
2333 die("deflateEnd on object %s failed (%d)", sha1_to_hex(sha1), ret);
748af44c
NP
2334 git_SHA1_Final(parano_sha1, &c);
2335 if (hashcmp(sha1, parano_sha1) != 0)
2336 die("confused by unstable object source data for %s", sha1_to_hex(sha1));
ac54c277 2337
e9039dd3 2338 close_sha1_file(fd);
0fcfd160 2339
bbac7311
NP
2340 if (mtime) {
2341 struct utimbuf utb;
2342 utb.actime = mtime;
2343 utb.modtime = mtime;
2344 if (utime(tmpfile, &utb) < 0)
2345 warning("failed utime() on %s: %s",
2346 tmpfile, strerror(errno));
2347 }
2348
230f1322 2349 return move_temp_to_file(tmpfile, filename);
0fcfd160 2350}
8237b185 2351
bbac7311
NP
2352int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1)
2353{
2354 unsigned char sha1[20];
2355 char hdr[32];
2356 int hdrlen;
2357
2358 /* Normally if we have it in the pack then we do not bother writing
2359 * it out into .git/objects/??/?{38} file.
2360 */
2361 write_sha1_file_prepare(buf, len, type, sha1, hdr, &hdrlen);
2362 if (returnsha1)
2363 hashcpy(returnsha1, sha1);
2364 if (has_sha1_file(sha1))
2365 return 0;
2366 return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
2367}
2368
2369int force_object_loose(const unsigned char *sha1, time_t mtime)
2370{
bbac7311
NP
2371 void *buf;
2372 unsigned long len;
2373 enum object_type type;
2374 char hdr[32];
2375 int hdrlen;
1fb23e65 2376 int ret;
bbac7311 2377
c529d75a 2378 if (has_loose_object(sha1))
bbac7311
NP
2379 return 0;
2380 buf = read_packed_sha1(sha1, &type, &len);
2381 if (!buf)
2382 return error("cannot read sha1_file for %s", sha1_to_hex(sha1));
2383 hdrlen = sprintf(hdr, "%s %lu", typename(type), len) + 1;
1fb23e65
BS
2384 ret = write_loose_object(sha1, hdr, hdrlen, buf, len, mtime);
2385 free(buf);
2386
2387 return ret;
bbac7311
NP
2388}
2389
bf592c50
DB
2390int has_pack_index(const unsigned char *sha1)
2391{
2392 struct stat st;
2393 if (stat(sha1_pack_index_name(sha1), &st))
2394 return 0;
2395 return 1;
bf592c50
DB
2396}
2397
cd673c1f
JH
2398int has_sha1_pack(const unsigned char *sha1)
2399{
2400 struct pack_entry e;
2401 return find_pack_entry(sha1, &e);
2402}
2403
8237b185
DB
2404int has_sha1_file(const unsigned char *sha1)
2405{
1f688557
JH
2406 struct pack_entry e;
2407
cd673c1f 2408 if (find_pack_entry(sha1, &e))
1f688557 2409 return 1;
c529d75a 2410 return has_loose_object(sha1);
8237b185 2411}
74400e71 2412
43df4f86
DP
2413static int index_mem(unsigned char *sha1, void *buf, size_t size,
2414 int write_object, enum object_type type, const char *path)
e7332f96 2415{
6c510bee 2416 int ret, re_allocated = 0;
74400e71 2417
7672db20 2418 if (!type)
edaec3fb 2419 type = OBJ_BLOB;
6c510bee
LT
2420
2421 /*
2422 * Convert blobs to git internal format
2423 */
43df4f86 2424 if ((type == OBJ_BLOB) && path) {
f285a2d7 2425 struct strbuf nbuf = STRBUF_INIT;
21e5ad50
SP
2426 if (convert_to_git(path, buf, size, &nbuf,
2427 write_object ? safe_crlf : 0)) {
b315c5c0 2428 buf = strbuf_detach(&nbuf, &size);
6c510bee
LT
2429 re_allocated = 1;
2430 }
2431 }
2432
7672db20 2433 if (write_object)
edaec3fb 2434 ret = write_sha1_file(buf, size, typename(type), sha1);
abdc3fc8 2435 else
edaec3fb 2436 ret = hash_sha1_file(buf, size, typename(type), sha1);
43df4f86 2437 if (re_allocated)
6c510bee 2438 free(buf);
43df4f86
DP
2439 return ret;
2440}
2441
ea68b0ce
DP
2442#define SMALL_FILE_SIZE (32*1024)
2443
43df4f86
DP
2444int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object,
2445 enum object_type type, const char *path)
2446{
2447 int ret;
2448 size_t size = xsize_t(st->st_size);
2449
2450 if (!S_ISREG(st->st_mode)) {
f285a2d7 2451 struct strbuf sbuf = STRBUF_INIT;
43df4f86
DP
2452 if (strbuf_read(&sbuf, fd, 4096) >= 0)
2453 ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object,
2454 type, path);
2455 else
2456 ret = -1;
2457 strbuf_release(&sbuf);
ea68b0ce
DP
2458 } else if (size <= SMALL_FILE_SIZE) {
2459 char *buf = xmalloc(size);
2460 if (size == read_in_full(fd, buf, size))
2461 ret = index_mem(sha1, buf, size, write_object, type,
2462 path);
2463 else
2464 ret = error("short read %s", strerror(errno));
2465 free(buf);
43df4f86
DP
2466 } else if (size) {
2467 void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
2468 ret = index_mem(sha1, buf, size, write_object, type, path);
aac17941 2469 munmap(buf, size);
43df4f86
DP
2470 } else
2471 ret = index_mem(sha1, NULL, size, write_object, type, path);
2472 close(fd);
aac17941 2473 return ret;
74400e71 2474}
ec1fcc16
JH
2475
2476int index_path(unsigned char *sha1, const char *path, struct stat *st, int write_object)
2477{
2478 int fd;
b760d3aa 2479 struct strbuf sb = STRBUF_INIT;
ec1fcc16
JH
2480
2481 switch (st->st_mode & S_IFMT) {
2482 case S_IFREG:
2483 fd = open(path, O_RDONLY);
2484 if (fd < 0)
2485 return error("open(\"%s\"): %s", path,
2486 strerror(errno));
53bca91a 2487 if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0)
ec1fcc16
JH
2488 return error("%s: failed to insert into database",
2489 path);
2490 break;
2491 case S_IFLNK:
b760d3aa 2492 if (strbuf_readlink(&sb, path, st->st_size)) {
ec1fcc16 2493 char *errstr = strerror(errno);
ec1fcc16
JH
2494 return error("readlink(\"%s\"): %s", path,
2495 errstr);
2496 }
abdc3fc8 2497 if (!write_object)
b760d3aa
LT
2498 hash_sha1_file(sb.buf, sb.len, blob_type, sha1);
2499 else if (write_sha1_file(sb.buf, sb.len, blob_type, sha1))
ec1fcc16
JH
2500 return error("%s: failed to insert into database",
2501 path);
b760d3aa 2502 strbuf_release(&sb);
ec1fcc16 2503 break;
f35a6d3b
LT
2504 case S_IFDIR:
2505 return resolve_gitlink_ref(path, "HEAD", sha1);
ec1fcc16
JH
2506 default:
2507 return error("%s: unsupported file type", path);
2508 }
2509 return 0;
2510}
a69e5429
JH
2511
2512int read_pack_header(int fd, struct pack_header *header)
2513{
c697ad14
HO
2514 if (read_in_full(fd, header, sizeof(*header)) < sizeof(*header))
2515 /* "eof before pack header was fully read" */
2516 return PH_ERROR_EOF;
2517
a69e5429
JH
2518 if (header->hdr_signature != htonl(PACK_SIGNATURE))
2519 /* "protocol error (pack signature mismatch detected)" */
2520 return PH_ERROR_PACK_SIGNATURE;
2521 if (!pack_version_ok(header->hdr_version))
2522 /* "protocol error (pack version unsupported)" */
2523 return PH_ERROR_PROTOCOL;
2524 return 0;
2525}