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Commit | Line | Data |
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7d0cdf82 | 1 | /* |
359fc2d2 | 2 | * Copyright (C) the libgit2 contributors. All rights reserved. |
7d0cdf82 | 3 | * |
bb742ede VM |
4 | * This file is part of libgit2, distributed under the GNU GPL v2 with |
5 | * a Linking Exception. For full terms see the included COPYING file. | |
7d0cdf82 CMN |
6 | */ |
7 | ||
7d0cdf82 | 8 | #include "pack.h" |
eae0bfdc | 9 | |
6a2d2f8a | 10 | #include "delta.h" |
0c9c969a | 11 | #include "futils.h" |
a15c550d | 12 | #include "mwindow.h" |
0c9c969a | 13 | #include "odb.h" |
b7f167da | 14 | #include "oid.h" |
7d0cdf82 | 15 | |
0c9c969a UG |
16 | /* Option to bypass checking existence of '.keep' files */ |
17 | bool git_disable_pack_keep_file_checks = false; | |
7d0cdf82 | 18 | |
a070f152 | 19 | static int packfile_open(struct git_pack_file *p); |
0c9c969a | 20 | static off64_t nth_packed_object_offset(const struct git_pack_file *p, uint32_t n); |
b644e223 | 21 | static int packfile_unpack_compressed( |
a070f152 CMN |
22 | git_rawobj *obj, |
23 | struct git_pack_file *p, | |
24 | git_mwindow **w_curs, | |
0c9c969a | 25 | off64_t *curpos, |
a070f152 | 26 | size_t size, |
ac3d33df | 27 | git_object_t type); |
a070f152 CMN |
28 | |
29 | /* Can find the offset of an object given | |
30 | * a prefix of an identifier. | |
904b67e6 | 31 | * Throws GIT_EAMBIGUOUSOIDPREFIX if short oid |
a070f152 CMN |
32 | * is ambiguous within the pack. |
33 | * This method assumes that len is between | |
34 | * GIT_OID_MINPREFIXLEN and GIT_OID_HEXSZ. | |
35 | */ | |
36 | static int pack_entry_find_offset( | |
0c9c969a | 37 | off64_t *offset_out, |
a070f152 CMN |
38 | git_oid *found_oid, |
39 | struct git_pack_file *p, | |
40 | const git_oid *short_oid, | |
b8457baa | 41 | size_t len); |
a070f152 | 42 | |
e1de726c RB |
43 | static int packfile_error(const char *message) |
44 | { | |
ac3d33df | 45 | git_error_set(GIT_ERROR_ODB, "invalid pack file - %s", message); |
e1de726c RB |
46 | return -1; |
47 | } | |
48 | ||
c8f79c2b CMN |
49 | /******************** |
50 | * Delta base cache | |
51 | ********************/ | |
c0f4a011 | 52 | |
525d961c | 53 | static git_pack_cache_entry *new_cache_object(git_rawobj *source) |
c0f4a011 | 54 | { |
c8f79c2b | 55 | git_pack_cache_entry *e = git__calloc(1, sizeof(git_pack_cache_entry)); |
c0f4a011 CMN |
56 | if (!e) |
57 | return NULL; | |
58 | ||
8588cb0c | 59 | git_atomic_inc(&e->refcount); |
c0f4a011 CMN |
60 | memcpy(&e->raw, source, sizeof(git_rawobj)); |
61 | ||
62 | return e; | |
63 | } | |
64 | ||
65 | static void free_cache_object(void *o) | |
66 | { | |
67 | git_pack_cache_entry *e = (git_pack_cache_entry *)o; | |
68 | ||
69 | if (e != NULL) { | |
0ed75620 | 70 | assert(e->refcount.val == 0); |
c0f4a011 CMN |
71 | git__free(e->raw.data); |
72 | git__free(e); | |
73 | } | |
74 | } | |
75 | ||
c8f79c2b CMN |
76 | static void cache_free(git_pack_cache *cache) |
77 | { | |
9694d9ba | 78 | git_pack_cache_entry *entry; |
c8f79c2b CMN |
79 | |
80 | if (cache->entries) { | |
9694d9ba PS |
81 | git_offmap_foreach_value(cache->entries, entry, { |
82 | free_cache_object(entry); | |
83 | }); | |
c8f79c2b CMN |
84 | |
85 | git_offmap_free(cache->entries); | |
649214be | 86 | cache->entries = NULL; |
c8f79c2b CMN |
87 | } |
88 | } | |
89 | ||
90 | static int cache_init(git_pack_cache *cache) | |
91 | { | |
0c9c969a UG |
92 | if (git_offmap_new(&cache->entries) < 0) |
93 | return -1; | |
f658dc43 | 94 | |
c8f79c2b | 95 | cache->memory_limit = GIT_PACK_CACHE_MEMORY_LIMIT; |
1a42dd17 RB |
96 | |
97 | if (git_mutex_init(&cache->lock)) { | |
ac3d33df | 98 | git_error_set(GIT_ERROR_OS, "failed to initialize pack cache mutex"); |
1a42dd17 RB |
99 | |
100 | git__free(cache->entries); | |
101 | cache->entries = NULL; | |
102 | ||
103 | return -1; | |
104 | } | |
c8f79c2b CMN |
105 | |
106 | return 0; | |
107 | } | |
108 | ||
0c9c969a | 109 | static git_pack_cache_entry *cache_get(git_pack_cache *cache, off64_t offset) |
c8f79c2b | 110 | { |
0c9c969a | 111 | git_pack_cache_entry *entry; |
c8f79c2b | 112 | |
09e29e47 CMN |
113 | if (git_mutex_lock(&cache->lock) < 0) |
114 | return NULL; | |
115 | ||
0c9c969a | 116 | if ((entry = git_offmap_get(cache->entries, offset)) != NULL) { |
c8f79c2b | 117 | git_atomic_inc(&entry->refcount); |
0ed75620 | 118 | entry->last_usage = cache->use_ctr++; |
c8f79c2b CMN |
119 | } |
120 | git_mutex_unlock(&cache->lock); | |
121 | ||
122 | return entry; | |
123 | } | |
124 | ||
0ed75620 CMN |
125 | /* Run with the cache lock held */ |
126 | static void free_lowest_entry(git_pack_cache *cache) | |
127 | { | |
0c9c969a | 128 | off64_t offset; |
ed6648ba | 129 | git_pack_cache_entry *entry; |
ed6648ba | 130 | |
685f2251 | 131 | git_offmap_foreach(cache->entries, offset, entry, { |
9c62aaab CMN |
132 | if (entry && entry->refcount.val == 0) { |
133 | cache->memory_used -= entry->raw.len; | |
685f2251 | 134 | git_offmap_delete(cache->entries, offset); |
9c62aaab | 135 | free_cache_object(entry); |
ed6648ba | 136 | } |
9694d9ba | 137 | }); |
0ed75620 CMN |
138 | } |
139 | ||
8588cb0c JH |
140 | static int cache_add( |
141 | git_pack_cache_entry **cached_out, | |
142 | git_pack_cache *cache, | |
143 | git_rawobj *base, | |
0c9c969a | 144 | off64_t offset) |
c8f79c2b CMN |
145 | { |
146 | git_pack_cache_entry *entry; | |
0c9c969a | 147 | int exists; |
c8f79c2b | 148 | |
0ed75620 CMN |
149 | if (base->len > GIT_PACK_CACHE_SIZE_LIMIT) |
150 | return -1; | |
151 | ||
c8f79c2b CMN |
152 | entry = new_cache_object(base); |
153 | if (entry) { | |
09e29e47 | 154 | if (git_mutex_lock(&cache->lock) < 0) { |
ac3d33df | 155 | git_error_set(GIT_ERROR_OS, "failed to lock cache"); |
6f73e026 | 156 | git__free(entry); |
09e29e47 CMN |
157 | return -1; |
158 | } | |
c8f79c2b | 159 | /* Add it to the cache if nobody else has */ |
036daa59 | 160 | exists = git_offmap_exists(cache->entries, offset); |
c8f79c2b | 161 | if (!exists) { |
0ed75620 CMN |
162 | while (cache->memory_used + base->len > cache->memory_limit) |
163 | free_lowest_entry(cache); | |
164 | ||
0c9c969a | 165 | git_offmap_set(cache->entries, offset, entry); |
0ed75620 | 166 | cache->memory_used += entry->raw.len; |
8588cb0c JH |
167 | |
168 | *cached_out = entry; | |
c8f79c2b CMN |
169 | } |
170 | git_mutex_unlock(&cache->lock); | |
171 | /* Somebody beat us to adding it into the cache */ | |
172 | if (exists) { | |
173 | git__free(entry); | |
174 | return -1; | |
175 | } | |
176 | } | |
177 | ||
178 | return 0; | |
179 | } | |
180 | ||
a070f152 CMN |
181 | /*********************************************************** |
182 | * | |
183 | * PACK INDEX METHODS | |
184 | * | |
185 | ***********************************************************/ | |
186 | ||
187 | static void pack_index_free(struct git_pack_file *p) | |
188 | { | |
60ecdf59 DMB |
189 | if (p->oids) { |
190 | git__free(p->oids); | |
191 | p->oids = NULL; | |
192 | } | |
a070f152 CMN |
193 | if (p->index_map.data) { |
194 | git_futils_mmap_free(&p->index_map); | |
195 | p->index_map.data = NULL; | |
196 | } | |
197 | } | |
198 | ||
87d9869f | 199 | static int pack_index_check(const char *path, struct git_pack_file *p) |
a070f152 CMN |
200 | { |
201 | struct git_pack_idx_header *hdr; | |
202 | uint32_t version, nr, i, *index; | |
a070f152 CMN |
203 | void *idx_map; |
204 | size_t idx_size; | |
a070f152 | 205 | struct stat st; |
a070f152 | 206 | int error; |
e1de726c RB |
207 | /* TODO: properly open the file without access time using O_NOATIME */ |
208 | git_file fd = git_futils_open_ro(path); | |
a070f152 | 209 | if (fd < 0) |
e1de726c | 210 | return fd; |
a070f152 | 211 | |
9d2f841a RB |
212 | if (p_fstat(fd, &st) < 0) { |
213 | p_close(fd); | |
ac3d33df | 214 | git_error_set(GIT_ERROR_OS, "unable to stat pack index '%s'", path); |
9d2f841a RB |
215 | return -1; |
216 | } | |
217 | ||
218 | if (!S_ISREG(st.st_mode) || | |
e1de726c RB |
219 | !git__is_sizet(st.st_size) || |
220 | (idx_size = (size_t)st.st_size) < 4 * 256 + 20 + 20) | |
221 | { | |
a070f152 | 222 | p_close(fd); |
ac3d33df | 223 | git_error_set(GIT_ERROR_ODB, "invalid pack index '%s'", path); |
e1de726c | 224 | return -1; |
a070f152 CMN |
225 | } |
226 | ||
227 | error = git_futils_mmap_ro(&p->index_map, fd, 0, idx_size); | |
e1de726c | 228 | |
a070f152 CMN |
229 | p_close(fd); |
230 | ||
e1de726c RB |
231 | if (error < 0) |
232 | return error; | |
a070f152 CMN |
233 | |
234 | hdr = idx_map = p->index_map.data; | |
235 | ||
236 | if (hdr->idx_signature == htonl(PACK_IDX_SIGNATURE)) { | |
237 | version = ntohl(hdr->idx_version); | |
238 | ||
239 | if (version < 2 || version > 2) { | |
240 | git_futils_mmap_free(&p->index_map); | |
e1de726c | 241 | return packfile_error("unsupported index version"); |
a070f152 CMN |
242 | } |
243 | ||
244 | } else | |
245 | version = 1; | |
246 | ||
247 | nr = 0; | |
248 | index = idx_map; | |
249 | ||
250 | if (version > 1) | |
87d9869f | 251 | index += 2; /* skip index header */ |
a070f152 CMN |
252 | |
253 | for (i = 0; i < 256; i++) { | |
254 | uint32_t n = ntohl(index[i]); | |
255 | if (n < nr) { | |
256 | git_futils_mmap_free(&p->index_map); | |
e1de726c | 257 | return packfile_error("index is non-monotonic"); |
a070f152 CMN |
258 | } |
259 | nr = n; | |
260 | } | |
261 | ||
262 | if (version == 1) { | |
263 | /* | |
264 | * Total size: | |
87d9869f VM |
265 | * - 256 index entries 4 bytes each |
266 | * - 24-byte entries * nr (20-byte sha1 + 4-byte offset) | |
267 | * - 20-byte SHA1 of the packfile | |
268 | * - 20-byte SHA1 file checksum | |
a070f152 CMN |
269 | */ |
270 | if (idx_size != 4*256 + nr * 24 + 20 + 20) { | |
271 | git_futils_mmap_free(&p->index_map); | |
e1de726c | 272 | return packfile_error("index is corrupted"); |
a070f152 CMN |
273 | } |
274 | } else if (version == 2) { | |
275 | /* | |
276 | * Minimum size: | |
87d9869f VM |
277 | * - 8 bytes of header |
278 | * - 256 index entries 4 bytes each | |
279 | * - 20-byte sha1 entry * nr | |
280 | * - 4-byte crc entry * nr | |
281 | * - 4-byte offset entry * nr | |
282 | * - 20-byte SHA1 of the packfile | |
283 | * - 20-byte SHA1 file checksum | |
a070f152 CMN |
284 | * And after the 4-byte offset table might be a |
285 | * variable sized table containing 8-byte entries | |
286 | * for offsets larger than 2^31. | |
287 | */ | |
288 | unsigned long min_size = 8 + 4*256 + nr*(20 + 4 + 4) + 20 + 20; | |
289 | unsigned long max_size = min_size; | |
290 | ||
291 | if (nr) | |
292 | max_size += (nr - 1)*8; | |
293 | ||
294 | if (idx_size < min_size || idx_size > max_size) { | |
295 | git_futils_mmap_free(&p->index_map); | |
e1de726c | 296 | return packfile_error("wrong index size"); |
a070f152 | 297 | } |
a070f152 CMN |
298 | } |
299 | ||
a070f152 | 300 | p->num_objects = nr; |
0ddfcb40 | 301 | p->index_version = version; |
e1de726c | 302 | return 0; |
a070f152 CMN |
303 | } |
304 | ||
305 | static int pack_index_open(struct git_pack_file *p) | |
306 | { | |
24c70804 | 307 | int error = 0; |
878293f7 | 308 | size_t name_len; |
a693b873 | 309 | git_buf idx_name; |
24c70804 | 310 | |
0ddfcb40 | 311 | if (p->index_version > -1) |
53607868 | 312 | return 0; |
a070f152 | 313 | |
24c70804 RB |
314 | name_len = strlen(p->pack_name); |
315 | assert(name_len > strlen(".pack")); /* checked by git_pack_file alloc */ | |
e1de726c | 316 | |
a693b873 PS |
317 | if (git_buf_init(&idx_name, name_len) < 0) |
318 | return -1; | |
319 | ||
878293f7 CMN |
320 | git_buf_put(&idx_name, p->pack_name, name_len - strlen(".pack")); |
321 | git_buf_puts(&idx_name, ".idx"); | |
322 | if (git_buf_oom(&idx_name)) { | |
ac3d33df | 323 | git_buf_dispose(&idx_name); |
53607868 | 324 | return -1; |
878293f7 | 325 | } |
a070f152 | 326 | |
050af8bb | 327 | if ((error = git_mutex_lock(&p->lock)) < 0) { |
ac3d33df | 328 | git_buf_dispose(&idx_name); |
53607868 | 329 | return error; |
050af8bb | 330 | } |
53607868 | 331 | |
0ddfcb40 | 332 | if (p->index_version == -1) |
878293f7 | 333 | error = pack_index_check(idx_name.ptr, p); |
24c70804 | 334 | |
ac3d33df | 335 | git_buf_dispose(&idx_name); |
a070f152 | 336 | |
24c70804 RB |
337 | git_mutex_unlock(&p->lock); |
338 | ||
e1de726c | 339 | return error; |
a070f152 CMN |
340 | } |
341 | ||
342 | static unsigned char *pack_window_open( | |
343 | struct git_pack_file *p, | |
7d0cdf82 | 344 | git_mwindow **w_cursor, |
0c9c969a | 345 | off64_t offset, |
7d0cdf82 CMN |
346 | unsigned int *left) |
347 | { | |
e1de726c | 348 | if (p->mwf.fd == -1 && packfile_open(p) < 0) |
7d0cdf82 CMN |
349 | return NULL; |
350 | ||
351 | /* Since packfiles end in a hash of their content and it's | |
352 | * pointless to ask for an offset into the middle of that | |
353 | * hash, and the pack_window_contains function above wouldn't match | |
354 | * don't allow an offset too close to the end of the file. | |
6d97beb9 CMN |
355 | * |
356 | * Don't allow a negative offset, as that means we've wrapped | |
357 | * around. | |
7d0cdf82 CMN |
358 | */ |
359 | if (offset > (p->mwf.size - 20)) | |
360 | return NULL; | |
6d97beb9 CMN |
361 | if (offset < 0) |
362 | return NULL; | |
7d0cdf82 CMN |
363 | |
364 | return git_mwindow_open(&p->mwf, w_cursor, offset, 20, left); | |
365 | } | |
366 | ||
51e82492 CMN |
367 | /* |
368 | * The per-object header is a pretty dense thing, which is | |
369 | * - first byte: low four bits are "size", | |
370 | * then three bits of "type", | |
371 | * with the high bit being "size continues". | |
372 | * - each byte afterwards: low seven bits are size continuation, | |
373 | * with the high bit being "size continues" | |
374 | */ | |
ac3d33df | 375 | size_t git_packfile__object_header(unsigned char *hdr, size_t size, git_object_t type) |
51e82492 CMN |
376 | { |
377 | unsigned char *hdr_base; | |
378 | unsigned char c; | |
379 | ||
ac3d33df | 380 | assert(type >= GIT_OBJECT_COMMIT && type <= GIT_OBJECT_REF_DELTA); |
51e82492 CMN |
381 | |
382 | /* TODO: add support for chunked objects; see git.git 6c0d19b1 */ | |
383 | ||
384 | c = (unsigned char)((type << 4) | (size & 15)); | |
385 | size >>= 4; | |
386 | hdr_base = hdr; | |
387 | ||
388 | while (size) { | |
389 | *hdr++ = c | 0x80; | |
390 | c = size & 0x7f; | |
391 | size >>= 7; | |
392 | } | |
393 | *hdr++ = c; | |
394 | ||
51a3dfb5 | 395 | return (hdr - hdr_base); |
51e82492 CMN |
396 | } |
397 | ||
398 | ||
45d773ef CMN |
399 | static int packfile_unpack_header1( |
400 | unsigned long *usedp, | |
7d0cdf82 | 401 | size_t *sizep, |
ac3d33df | 402 | git_object_t *type, |
7d0cdf82 CMN |
403 | const unsigned char *buf, |
404 | unsigned long len) | |
405 | { | |
406 | unsigned shift; | |
407 | unsigned long size, c; | |
408 | unsigned long used = 0; | |
2aeadb9c | 409 | |
7d0cdf82 CMN |
410 | c = buf[used++]; |
411 | *type = (c >> 4) & 7; | |
412 | size = c & 15; | |
413 | shift = 4; | |
414 | while (c & 0x80) { | |
ec7e680c | 415 | if (len <= used) { |
ac3d33df | 416 | git_error_set(GIT_ERROR_ODB, "buffer too small"); |
904b67e6 | 417 | return GIT_EBUFS; |
ec7e680c | 418 | } |
45d773ef CMN |
419 | |
420 | if (bitsizeof(long) <= shift) { | |
421 | *usedp = 0; | |
ac3d33df | 422 | git_error_set(GIT_ERROR_ODB, "packfile corrupted"); |
45d773ef CMN |
423 | return -1; |
424 | } | |
7d0cdf82 CMN |
425 | |
426 | c = buf[used++]; | |
427 | size += (c & 0x7f) << shift; | |
428 | shift += 7; | |
429 | } | |
430 | ||
431 | *sizep = (size_t)size; | |
45d773ef CMN |
432 | *usedp = used; |
433 | return 0; | |
7d0cdf82 CMN |
434 | } |
435 | ||
436 | int git_packfile_unpack_header( | |
437 | size_t *size_p, | |
ac3d33df | 438 | git_object_t *type_p, |
7d0cdf82 CMN |
439 | git_mwindow_file *mwf, |
440 | git_mwindow **w_curs, | |
0c9c969a | 441 | off64_t *curpos) |
7d0cdf82 CMN |
442 | { |
443 | unsigned char *base; | |
444 | unsigned int left; | |
445 | unsigned long used; | |
45d773ef | 446 | int ret; |
7d0cdf82 CMN |
447 | |
448 | /* pack_window_open() assures us we have [base, base + 20) available | |
87d9869f VM |
449 | * as a range that we can look at at. (Its actually the hash |
450 | * size that is assured.) With our object header encoding | |
7d0cdf82 CMN |
451 | * the maximum deflated object size is 2^137, which is just |
452 | * insane, so we know won't exceed what we have been given. | |
453 | */ | |
24c70804 | 454 | /* base = pack_window_open(p, w_curs, *curpos, &left); */ |
7d0cdf82 CMN |
455 | base = git_mwindow_open(mwf, w_curs, *curpos, 20, &left); |
456 | if (base == NULL) | |
904b67e6 | 457 | return GIT_EBUFS; |
2aeadb9c | 458 | |
9d2f841a | 459 | ret = packfile_unpack_header1(&used, size_p, type_p, base, left); |
45d773ef | 460 | git_mwindow_close(w_curs); |
904b67e6 | 461 | if (ret == GIT_EBUFS) |
45d773ef CMN |
462 | return ret; |
463 | else if (ret < 0) | |
e1de726c | 464 | return packfile_error("header length is zero"); |
7d0cdf82 CMN |
465 | |
466 | *curpos += used; | |
e1de726c | 467 | return 0; |
7d0cdf82 CMN |
468 | } |
469 | ||
44f9f547 DMB |
470 | int git_packfile_resolve_header( |
471 | size_t *size_p, | |
ac3d33df | 472 | git_object_t *type_p, |
44f9f547 | 473 | struct git_pack_file *p, |
0c9c969a | 474 | off64_t offset) |
44f9f547 DMB |
475 | { |
476 | git_mwindow *w_curs = NULL; | |
0c9c969a | 477 | off64_t curpos = offset; |
44f9f547 | 478 | size_t size; |
ac3d33df | 479 | git_object_t type; |
0c9c969a | 480 | off64_t base_offset; |
44f9f547 DMB |
481 | int error; |
482 | ||
483 | error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos); | |
44f9f547 DMB |
484 | if (error < 0) |
485 | return error; | |
486 | ||
ac3d33df | 487 | if (type == GIT_OBJECT_OFS_DELTA || type == GIT_OBJECT_REF_DELTA) { |
44f9f547 | 488 | size_t base_size; |
a97b769a CMN |
489 | git_packfile_stream stream; |
490 | ||
44f9f547 DMB |
491 | base_offset = get_delta_base(p, &w_curs, &curpos, type, offset); |
492 | git_mwindow_close(&w_curs); | |
a97b769a | 493 | if ((error = git_packfile_stream_open(&stream, p, curpos)) < 0) |
44f9f547 | 494 | return error; |
6a2d2f8a | 495 | error = git_delta_read_header_fromstream(&base_size, size_p, &stream); |
ac3d33df | 496 | git_packfile_stream_dispose(&stream); |
44f9f547 DMB |
497 | if (error < 0) |
498 | return error; | |
34b32053 | 499 | } else { |
44f9f547 | 500 | *size_p = size; |
34b32053 PS |
501 | base_offset = 0; |
502 | } | |
44f9f547 | 503 | |
ac3d33df | 504 | while (type == GIT_OBJECT_OFS_DELTA || type == GIT_OBJECT_REF_DELTA) { |
44f9f547 DMB |
505 | curpos = base_offset; |
506 | error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos); | |
44f9f547 DMB |
507 | if (error < 0) |
508 | return error; | |
ac3d33df | 509 | if (type != GIT_OBJECT_OFS_DELTA && type != GIT_OBJECT_REF_DELTA) |
44f9f547 DMB |
510 | break; |
511 | base_offset = get_delta_base(p, &w_curs, &curpos, type, base_offset); | |
512 | git_mwindow_close(&w_curs); | |
513 | } | |
514 | *type_p = type; | |
515 | ||
516 | return error; | |
517 | } | |
518 | ||
15bcced2 CMN |
519 | #define SMALL_STACK_SIZE 64 |
520 | ||
a3ffbf23 CMN |
521 | /** |
522 | * Generate the chain of dependencies which we need to get to the | |
523 | * object at `off`. `chain` is used a stack, popping gives the right | |
524 | * order to apply deltas on. If an object is found in the pack's base | |
525 | * cache, we stop calculating there. | |
526 | */ | |
15bcced2 | 527 | static int pack_dependency_chain(git_dependency_chain *chain_out, |
0c9c969a | 528 | git_pack_cache_entry **cached_out, off64_t *cached_off, |
15bcced2 | 529 | struct pack_chain_elem *small_stack, size_t *stack_sz, |
0c9c969a | 530 | struct git_pack_file *p, off64_t obj_offset) |
a3ffbf23 CMN |
531 | { |
532 | git_dependency_chain chain = GIT_ARRAY_INIT; | |
533 | git_mwindow *w_curs = NULL; | |
0c9c969a | 534 | off64_t curpos = obj_offset, base_offset; |
15bcced2 CMN |
535 | int error = 0, use_heap = 0; |
536 | size_t size, elem_pos; | |
ac3d33df | 537 | git_object_t type; |
a3ffbf23 | 538 | |
15bcced2 | 539 | elem_pos = 0; |
a3ffbf23 CMN |
540 | while (true) { |
541 | struct pack_chain_elem *elem; | |
542 | git_pack_cache_entry *cached = NULL; | |
543 | ||
544 | /* if we have a base cached, we can stop here instead */ | |
545 | if ((cached = cache_get(&p->bases, obj_offset)) != NULL) { | |
546 | *cached_out = cached; | |
547 | *cached_off = obj_offset; | |
548 | break; | |
549 | } | |
550 | ||
15bcced2 CMN |
551 | /* if we run out of space on the small stack, use the array */ |
552 | if (elem_pos == SMALL_STACK_SIZE) { | |
553 | git_array_init_to_size(chain, elem_pos); | |
ac3d33df | 554 | GIT_ERROR_CHECK_ARRAY(chain); |
15bcced2 CMN |
555 | memcpy(chain.ptr, small_stack, elem_pos * sizeof(struct pack_chain_elem)); |
556 | chain.size = elem_pos; | |
557 | use_heap = 1; | |
558 | } | |
559 | ||
a3ffbf23 | 560 | curpos = obj_offset; |
15bcced2 CMN |
561 | if (!use_heap) { |
562 | elem = &small_stack[elem_pos]; | |
563 | } else { | |
564 | elem = git_array_alloc(chain); | |
565 | if (!elem) { | |
566 | error = -1; | |
567 | goto on_error; | |
568 | } | |
a3ffbf23 CMN |
569 | } |
570 | ||
571 | elem->base_key = obj_offset; | |
572 | ||
573 | error = git_packfile_unpack_header(&size, &type, &p->mwf, &w_curs, &curpos); | |
a3ffbf23 CMN |
574 | |
575 | if (error < 0) | |
576 | goto on_error; | |
577 | ||
578 | elem->offset = curpos; | |
579 | elem->size = size; | |
580 | elem->type = type; | |
581 | elem->base_key = obj_offset; | |
582 | ||
ac3d33df | 583 | if (type != GIT_OBJECT_OFS_DELTA && type != GIT_OBJECT_REF_DELTA) |
a3ffbf23 CMN |
584 | break; |
585 | ||
586 | base_offset = get_delta_base(p, &w_curs, &curpos, type, obj_offset); | |
587 | git_mwindow_close(&w_curs); | |
588 | ||
589 | if (base_offset == 0) { | |
590 | error = packfile_error("delta offset is zero"); | |
591 | goto on_error; | |
592 | } | |
593 | if (base_offset < 0) { /* must actually be an error code */ | |
594 | error = (int)base_offset; | |
595 | goto on_error; | |
596 | } | |
597 | ||
598 | /* we need to pass the pos *after* the delta-base bit */ | |
599 | elem->offset = curpos; | |
600 | ||
601 | /* go through the loop again, but with the new object */ | |
602 | obj_offset = base_offset; | |
15bcced2 | 603 | elem_pos++; |
a3ffbf23 CMN |
604 | } |
605 | ||
ac3d33df | 606 | |
15bcced2 | 607 | *stack_sz = elem_pos + 1; |
a3ffbf23 CMN |
608 | *chain_out = chain; |
609 | return error; | |
610 | ||
611 | on_error: | |
612 | git_array_clear(chain); | |
613 | return error; | |
614 | } | |
615 | ||
a070f152 | 616 | int git_packfile_unpack( |
e1de726c RB |
617 | git_rawobj *obj, |
618 | struct git_pack_file *p, | |
0c9c969a | 619 | off64_t *obj_offset) |
7d0cdf82 CMN |
620 | { |
621 | git_mwindow *w_curs = NULL; | |
0c9c969a | 622 | off64_t curpos = *obj_offset; |
a332e91c CMN |
623 | int error, free_base = 0; |
624 | git_dependency_chain chain = GIT_ARRAY_INIT; | |
15bcced2 | 625 | struct pack_chain_elem *elem = NULL, *stack; |
a332e91c | 626 | git_pack_cache_entry *cached = NULL; |
15bcced2 | 627 | struct pack_chain_elem small_stack[SMALL_STACK_SIZE]; |
f1453c59 | 628 | size_t stack_size = 0, elem_pos, alloclen; |
ac3d33df | 629 | git_object_t base_type; |
7d0cdf82 CMN |
630 | |
631 | /* | |
632 | * TODO: optionally check the CRC on the packfile | |
633 | */ | |
634 | ||
15bcced2 | 635 | error = pack_dependency_chain(&chain, &cached, obj_offset, small_stack, &stack_size, p, *obj_offset); |
2acdf4b8 CMN |
636 | if (error < 0) |
637 | return error; | |
638 | ||
7d0cdf82 CMN |
639 | obj->data = NULL; |
640 | obj->len = 0; | |
ac3d33df | 641 | obj->type = GIT_OBJECT_INVALID; |
7d0cdf82 | 642 | |
15bcced2 CMN |
643 | /* let's point to the right stack */ |
644 | stack = chain.ptr ? chain.ptr : small_stack; | |
645 | ||
646 | elem_pos = stack_size; | |
a3ffbf23 | 647 | if (cached) { |
a332e91c | 648 | memcpy(obj, &cached->raw, sizeof(git_rawobj)); |
a3ffbf23 | 649 | base_type = obj->type; |
15bcced2 | 650 | elem_pos--; /* stack_size includes the base, which isn't actually there */ |
a3ffbf23 | 651 | } else { |
15bcced2 | 652 | elem = &stack[--elem_pos]; |
a3ffbf23 | 653 | base_type = elem->type; |
a332e91c | 654 | } |
45d773ef | 655 | |
9dbd150f | 656 | switch (base_type) { |
ac3d33df JK |
657 | case GIT_OBJECT_COMMIT: |
658 | case GIT_OBJECT_TREE: | |
659 | case GIT_OBJECT_BLOB: | |
660 | case GIT_OBJECT_TAG: | |
a3ffbf23 | 661 | if (!cached) { |
9dbd150f CMN |
662 | curpos = elem->offset; |
663 | error = packfile_unpack_compressed(obj, p, &w_curs, &curpos, elem->size, elem->type); | |
664 | git_mwindow_close(&w_curs); | |
a3ffbf23 | 665 | base_type = elem->type; |
9dbd150f CMN |
666 | } |
667 | if (error < 0) | |
668 | goto cleanup; | |
669 | break; | |
ac3d33df JK |
670 | case GIT_OBJECT_OFS_DELTA: |
671 | case GIT_OBJECT_REF_DELTA: | |
9dbd150f CMN |
672 | error = packfile_error("dependency chain ends in a delta"); |
673 | goto cleanup; | |
674 | default: | |
675 | error = packfile_error("invalid packfile type in header"); | |
676 | goto cleanup; | |
677 | } | |
678 | ||
a332e91c | 679 | /* |
c968ce2c | 680 | * Finding the object we want a cached base element is |
a332e91c CMN |
681 | * problematic, as we need to make sure we don't accidentally |
682 | * give the caller the cached object, which it would then feel | |
683 | * free to free, so we need to copy the data. | |
684 | */ | |
15bcced2 | 685 | if (cached && stack_size == 1) { |
a332e91c | 686 | void *data = obj->data; |
392702ee | 687 | |
ac3d33df | 688 | GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, obj->len, 1); |
f1453c59 | 689 | obj->data = git__malloc(alloclen); |
ac3d33df | 690 | GIT_ERROR_CHECK_ALLOC(obj->data); |
392702ee | 691 | |
a332e91c CMN |
692 | memcpy(obj->data, data, obj->len + 1); |
693 | git_atomic_dec(&cached->refcount); | |
694 | goto cleanup; | |
695 | } | |
696 | ||
2acdf4b8 | 697 | /* we now apply each consecutive delta until we run out */ |
15bcced2 | 698 | while (elem_pos > 0 && !error) { |
2acdf4b8 CMN |
699 | git_rawobj base, delta; |
700 | ||
c968ce2c CMN |
701 | /* |
702 | * We can now try to add the base to the cache, as | |
703 | * long as it's not already the cached one. | |
704 | */ | |
705 | if (!cached) | |
8588cb0c | 706 | free_base = !!cache_add(&cached, &p->bases, obj, elem->base_key); |
c968ce2c | 707 | |
15bcced2 | 708 | elem = &stack[elem_pos - 1]; |
2acdf4b8 CMN |
709 | curpos = elem->offset; |
710 | error = packfile_unpack_compressed(&delta, p, &w_curs, &curpos, elem->size, elem->type); | |
711 | git_mwindow_close(&w_curs); | |
712 | ||
eae0bfdc PP |
713 | if (error < 0) { |
714 | /* We have transferred ownership of the data to the cache. */ | |
715 | obj->data = NULL; | |
2acdf4b8 | 716 | break; |
eae0bfdc | 717 | } |
2acdf4b8 CMN |
718 | |
719 | /* the current object becomes the new base, on which we apply the delta */ | |
720 | base = *obj; | |
721 | obj->data = NULL; | |
722 | obj->len = 0; | |
ac3d33df | 723 | obj->type = GIT_OBJECT_INVALID; |
2acdf4b8 | 724 | |
6a2d2f8a | 725 | error = git_delta_apply(&obj->data, &obj->len, base.data, base.len, delta.data, delta.len); |
a332e91c | 726 | obj->type = base_type; |
6a2d2f8a | 727 | |
a332e91c CMN |
728 | /* |
729 | * We usually don't want to free the base at this | |
730 | * point, as we put it into the cache in the previous | |
731 | * iteration. free_base lets us know that we got the | |
732 | * base object directly from the packfile, so we can free it. | |
733 | */ | |
2acdf4b8 | 734 | git__free(delta.data); |
a332e91c CMN |
735 | if (free_base) { |
736 | free_base = 0; | |
737 | git__free(base.data); | |
738 | } | |
739 | ||
740 | if (cached) { | |
741 | git_atomic_dec(&cached->refcount); | |
742 | cached = NULL; | |
743 | } | |
2acdf4b8 CMN |
744 | |
745 | if (error < 0) | |
746 | break; | |
7d0cdf82 | 747 | |
15bcced2 | 748 | elem_pos--; |
7d0cdf82 CMN |
749 | } |
750 | ||
2acdf4b8 | 751 | cleanup: |
ff5eea06 | 752 | if (error < 0) { |
a332e91c | 753 | git__free(obj->data); |
ff5eea06 PS |
754 | if (cached) |
755 | git_atomic_dec(&cached->refcount); | |
756 | } | |
a332e91c | 757 | |
a3ffbf23 | 758 | if (elem) |
b3d3459f | 759 | *obj_offset = curpos; |
a332e91c | 760 | |
2acdf4b8 | 761 | git_array_clear(chain); |
e1de726c | 762 | return error; |
7d0cdf82 CMN |
763 | } |
764 | ||
0c9c969a | 765 | int git_packfile_stream_open(git_packfile_stream *obj, struct git_pack_file *p, off64_t curpos) |
282283ac | 766 | { |
46635339 CMN |
767 | memset(obj, 0, sizeof(git_packfile_stream)); |
768 | obj->curpos = curpos; | |
769 | obj->p = p; | |
0c9c969a UG |
770 | |
771 | if (git_zstream_init(&obj->zstream, GIT_ZSTREAM_INFLATE) < 0) { | |
ac3d33df | 772 | git_error_set(GIT_ERROR_ZLIB, "failed to init packfile stream"); |
46635339 CMN |
773 | return -1; |
774 | } | |
775 | ||
776 | return 0; | |
777 | } | |
778 | ||
779 | ssize_t git_packfile_stream_read(git_packfile_stream *obj, void *buffer, size_t len) | |
780 | { | |
0c9c969a | 781 | unsigned int window_len; |
46635339 | 782 | unsigned char *in; |
0c9c969a | 783 | int error; |
46635339 CMN |
784 | |
785 | if (obj->done) | |
786 | return 0; | |
787 | ||
0c9c969a | 788 | if ((in = pack_window_open(obj->p, &obj->mw, obj->curpos, &window_len)) == NULL) |
46635339 CMN |
789 | return GIT_EBUFS; |
790 | ||
0c9c969a UG |
791 | if ((error = git_zstream_set_input(&obj->zstream, in, window_len)) < 0 || |
792 | (error = git_zstream_get_output_chunk(buffer, &len, &obj->zstream)) < 0) { | |
793 | git_mwindow_close(&obj->mw); | |
ac3d33df | 794 | git_error_set(GIT_ERROR_ZLIB, "error reading from the zlib stream"); |
46635339 CMN |
795 | return -1; |
796 | } | |
797 | ||
0c9c969a | 798 | git_mwindow_close(&obj->mw); |
46635339 | 799 | |
0c9c969a UG |
800 | obj->curpos += window_len - obj->zstream.in_len; |
801 | ||
802 | if (git_zstream_eos(&obj->zstream)) | |
803 | obj->done = 1; | |
46635339 CMN |
804 | |
805 | /* If we didn't write anything out but we're not done, we need more data */ | |
0c9c969a | 806 | if (!len && !git_zstream_eos(&obj->zstream)) |
46635339 CMN |
807 | return GIT_EBUFS; |
808 | ||
0c9c969a | 809 | return len; |
46635339 CMN |
810 | |
811 | } | |
812 | ||
ac3d33df | 813 | void git_packfile_stream_dispose(git_packfile_stream *obj) |
46635339 | 814 | { |
0c9c969a | 815 | git_zstream_free(&obj->zstream); |
46635339 CMN |
816 | } |
817 | ||
b644e223 | 818 | static int packfile_unpack_compressed( |
e1de726c RB |
819 | git_rawobj *obj, |
820 | struct git_pack_file *p, | |
0c9c969a UG |
821 | git_mwindow **mwindow, |
822 | off64_t *position, | |
e1de726c | 823 | size_t size, |
ac3d33df | 824 | git_object_t type) |
7d0cdf82 | 825 | { |
0c9c969a UG |
826 | git_zstream zstream = GIT_ZSTREAM_INIT; |
827 | size_t buffer_len, total = 0; | |
828 | char *data = NULL; | |
829 | int error; | |
45d773ef | 830 | |
0c9c969a UG |
831 | GIT_ERROR_CHECK_ALLOC_ADD(&buffer_len, size, 1); |
832 | data = git__calloc(1, buffer_len); | |
833 | GIT_ERROR_CHECK_ALLOC(data); | |
834 | ||
835 | if ((error = git_zstream_init(&zstream, GIT_ZSTREAM_INFLATE)) < 0) { | |
836 | git_error_set(GIT_ERROR_ZLIB, "failed to init zlib stream on unpack"); | |
837 | goto out; | |
7d0cdf82 CMN |
838 | } |
839 | ||
840 | do { | |
0c9c969a UG |
841 | size_t bytes = buffer_len - total; |
842 | unsigned int window_len; | |
843 | unsigned char *in; | |
7d0cdf82 | 844 | |
0c9c969a | 845 | in = pack_window_open(p, mwindow, *position, &window_len); |
7d0cdf82 | 846 | |
0c9c969a UG |
847 | if ((error = git_zstream_set_input(&zstream, in, window_len)) < 0 || |
848 | (error = git_zstream_get_output_chunk(data + total, &bytes, &zstream)) < 0) { | |
849 | git_mwindow_close(mwindow); | |
850 | goto out; | |
45d773ef CMN |
851 | } |
852 | ||
0c9c969a | 853 | git_mwindow_close(mwindow); |
7d0cdf82 | 854 | |
0c9c969a UG |
855 | *position += window_len - zstream.in_len; |
856 | total += bytes; | |
857 | } while (total < size); | |
7d0cdf82 | 858 | |
0c9c969a | 859 | if (total != size || !git_zstream_eos(&zstream)) { |
ac3d33df | 860 | git_error_set(GIT_ERROR_ZLIB, "error inflating zlib stream"); |
0c9c969a UG |
861 | error = -1; |
862 | goto out; | |
7d0cdf82 CMN |
863 | } |
864 | ||
865 | obj->type = type; | |
866 | obj->len = size; | |
0c9c969a UG |
867 | obj->data = data; |
868 | ||
869 | out: | |
870 | git_zstream_free(&zstream); | |
871 | if (error) | |
872 | git__free(data); | |
873 | ||
874 | return error; | |
7d0cdf82 CMN |
875 | } |
876 | ||
b5b474dd CMN |
877 | /* |
878 | * curpos is where the data starts, delta_obj_offset is the where the | |
879 | * header starts | |
880 | */ | |
0c9c969a | 881 | off64_t get_delta_base( |
e1de726c RB |
882 | struct git_pack_file *p, |
883 | git_mwindow **w_curs, | |
0c9c969a | 884 | off64_t *curpos, |
ac3d33df | 885 | git_object_t type, |
0c9c969a | 886 | off64_t delta_obj_offset) |
7d0cdf82 | 887 | { |
45d773ef CMN |
888 | unsigned int left = 0; |
889 | unsigned char *base_info; | |
0c9c969a | 890 | off64_t base_offset; |
7d0cdf82 CMN |
891 | git_oid unused; |
892 | ||
45d773ef CMN |
893 | base_info = pack_window_open(p, w_curs, *curpos, &left); |
894 | /* Assumption: the only reason this would fail is because the file is too small */ | |
895 | if (base_info == NULL) | |
904b67e6 | 896 | return GIT_EBUFS; |
7d0cdf82 CMN |
897 | /* pack_window_open() assured us we have [base_info, base_info + 20) |
898 | * as a range that we can look at without walking off the | |
87d9869f VM |
899 | * end of the mapped window. Its actually the hash size |
900 | * that is assured. An OFS_DELTA longer than the hash size | |
7d0cdf82 CMN |
901 | * is stupid, as then a REF_DELTA would be smaller to store. |
902 | */ | |
ac3d33df | 903 | if (type == GIT_OBJECT_OFS_DELTA) { |
7d0cdf82 CMN |
904 | unsigned used = 0; |
905 | unsigned char c = base_info[used++]; | |
eae0bfdc | 906 | size_t unsigned_base_offset = c & 127; |
7d0cdf82 | 907 | while (c & 128) { |
45d773ef | 908 | if (left <= used) |
904b67e6 | 909 | return GIT_EBUFS; |
eae0bfdc PP |
910 | unsigned_base_offset += 1; |
911 | if (!unsigned_base_offset || MSB(unsigned_base_offset, 7)) | |
87d9869f | 912 | return 0; /* overflow */ |
7d0cdf82 | 913 | c = base_info[used++]; |
eae0bfdc | 914 | unsigned_base_offset = (unsigned_base_offset << 7) + (c & 127); |
7d0cdf82 | 915 | } |
eae0bfdc | 916 | if (unsigned_base_offset == 0 || (size_t)delta_obj_offset <= unsigned_base_offset) |
87d9869f | 917 | return 0; /* out of bound */ |
eae0bfdc | 918 | base_offset = delta_obj_offset - unsigned_base_offset; |
7d0cdf82 | 919 | *curpos += used; |
ac3d33df | 920 | } else if (type == GIT_OBJECT_REF_DELTA) { |
c1af5a39 CMN |
921 | /* If we have the cooperative cache, search in it first */ |
922 | if (p->has_cache) { | |
0c9c969a | 923 | struct git_pack_entry *entry; |
0e040c03 | 924 | git_oid oid; |
c1af5a39 | 925 | |
0e040c03 | 926 | git_oid_fromraw(&oid, base_info); |
0c9c969a | 927 | if ((entry = git_oidmap_get(p->idx_cache, &oid)) != NULL) { |
c1af5a39 | 928 | *curpos += 20; |
0c9c969a | 929 | return entry->offset; |
38c10ecd ET |
930 | } else { |
931 | /* If we're building an index, don't try to find the pack | |
932 | * entry; we just haven't seen it yet. We'll make | |
933 | * progress again in the next loop. | |
934 | */ | |
935 | return GIT_PASSTHROUGH; | |
c1af5a39 CMN |
936 | } |
937 | } | |
38c10ecd | 938 | |
7d0cdf82 | 939 | /* The base entry _must_ be in the same pack */ |
e1de726c RB |
940 | if (pack_entry_find_offset(&base_offset, &unused, p, (git_oid *)base_info, GIT_OID_HEXSZ) < 0) |
941 | return packfile_error("base entry delta is not in the same pack"); | |
7d0cdf82 CMN |
942 | *curpos += 20; |
943 | } else | |
944 | return 0; | |
945 | ||
946 | return base_offset; | |
947 | } | |
a070f152 CMN |
948 | |
949 | /*********************************************************** | |
950 | * | |
951 | * PACKFILE METHODS | |
952 | * | |
953 | ***********************************************************/ | |
954 | ||
bf339ab0 ET |
955 | void git_packfile_close(struct git_pack_file *p, bool unlink_packfile) |
956 | { | |
957 | if (p->mwf.fd >= 0) { | |
958 | git_mwindow_free_all_locked(&p->mwf); | |
959 | p_close(p->mwf.fd); | |
960 | p->mwf.fd = -1; | |
961 | } | |
962 | ||
963 | if (unlink_packfile) | |
964 | p_unlink(p->pack_name); | |
965 | } | |
966 | ||
96c9b9f0 | 967 | void git_packfile_free(struct git_pack_file *p) |
a070f152 | 968 | { |
24c70804 RB |
969 | if (!p) |
970 | return; | |
971 | ||
c8f79c2b | 972 | cache_free(&p->bases); |
c0f4a011 | 973 | |
bf339ab0 | 974 | git_packfile_close(p, false); |
a070f152 CMN |
975 | |
976 | pack_index_free(p); | |
977 | ||
3286c408 | 978 | git__free(p->bad_object_sha1); |
24c70804 | 979 | |
24c70804 | 980 | git_mutex_free(&p->lock); |
649214be | 981 | git_mutex_free(&p->bases.lock); |
3286c408 | 982 | git__free(p); |
a070f152 CMN |
983 | } |
984 | ||
985 | static int packfile_open(struct git_pack_file *p) | |
986 | { | |
987 | struct stat st; | |
988 | struct git_pack_header hdr; | |
989 | git_oid sha1; | |
990 | unsigned char *idx_sha1; | |
991 | ||
0ddfcb40 | 992 | if (p->index_version == -1 && pack_index_open(p) < 0) |
e10144ae | 993 | return git_odb__error_notfound("failed to open packfile", NULL, 0); |
a070f152 | 994 | |
9d2f841a RB |
995 | /* if mwf opened by another thread, return now */ |
996 | if (git_mutex_lock(&p->lock) < 0) | |
997 | return packfile_error("failed to get lock for open"); | |
998 | ||
999 | if (p->mwf.fd >= 0) { | |
1000 | git_mutex_unlock(&p->lock); | |
1001 | return 0; | |
1002 | } | |
1003 | ||
a070f152 | 1004 | /* TODO: open with noatime */ |
e1de726c | 1005 | p->mwf.fd = git_futils_open_ro(p->pack_name); |
9d2f841a RB |
1006 | if (p->mwf.fd < 0) |
1007 | goto cleanup; | |
a070f152 | 1008 | |
e1de726c RB |
1009 | if (p_fstat(p->mwf.fd, &st) < 0 || |
1010 | git_mwindow_file_register(&p->mwf) < 0) | |
1011 | goto cleanup; | |
a070f152 CMN |
1012 | |
1013 | /* If we created the struct before we had the pack we lack size. */ | |
1014 | if (!p->mwf.size) { | |
1015 | if (!S_ISREG(st.st_mode)) | |
1016 | goto cleanup; | |
0c9c969a | 1017 | p->mwf.size = (off64_t)st.st_size; |
a070f152 CMN |
1018 | } else if (p->mwf.size != st.st_size) |
1019 | goto cleanup; | |
1020 | ||
1021 | #if 0 | |
1022 | /* We leave these file descriptors open with sliding mmap; | |
1023 | * there is no point keeping them open across exec(), though. | |
1024 | */ | |
1025 | fd_flag = fcntl(p->mwf.fd, F_GETFD, 0); | |
1026 | if (fd_flag < 0) | |
e1de726c | 1027 | goto cleanup; |
a070f152 CMN |
1028 | |
1029 | fd_flag |= FD_CLOEXEC; | |
1030 | if (fcntl(p->pack_fd, F_SETFD, fd_flag) == -1) | |
e1de726c | 1031 | goto cleanup; |
a070f152 CMN |
1032 | #endif |
1033 | ||
1034 | /* Verify we recognize this pack file format. */ | |
e1de726c RB |
1035 | if (p_read(p->mwf.fd, &hdr, sizeof(hdr)) < 0 || |
1036 | hdr.hdr_signature != htonl(PACK_SIGNATURE) || | |
1037 | !pack_version_ok(hdr.hdr_version)) | |
a070f152 CMN |
1038 | goto cleanup; |
1039 | ||
1040 | /* Verify the pack matches its index. */ | |
e1de726c RB |
1041 | if (p->num_objects != ntohl(hdr.hdr_entries) || |
1042 | p_lseek(p->mwf.fd, p->mwf.size - GIT_OID_RAWSZ, SEEK_SET) == -1 || | |
1043 | p_read(p->mwf.fd, sha1.id, GIT_OID_RAWSZ) < 0) | |
a070f152 CMN |
1044 | goto cleanup; |
1045 | ||
1046 | idx_sha1 = ((unsigned char *)p->index_map.data) + p->index_map.len - 40; | |
1047 | ||
9d2f841a RB |
1048 | if (git_oid__cmp(&sha1, (git_oid *)idx_sha1) != 0) |
1049 | goto cleanup; | |
1050 | ||
1051 | git_mutex_unlock(&p->lock); | |
1052 | return 0; | |
a070f152 CMN |
1053 | |
1054 | cleanup: | |
ac3d33df | 1055 | git_error_set(GIT_ERROR_OS, "invalid packfile '%s'", p->pack_name); |
9d2f841a | 1056 | |
3a2d48d5 SS |
1057 | if (p->mwf.fd >= 0) |
1058 | p_close(p->mwf.fd); | |
a070f152 | 1059 | p->mwf.fd = -1; |
9d2f841a RB |
1060 | |
1061 | git_mutex_unlock(&p->lock); | |
1062 | ||
e1de726c | 1063 | return -1; |
a070f152 CMN |
1064 | } |
1065 | ||
b3b66c57 CMN |
1066 | int git_packfile__name(char **out, const char *path) |
1067 | { | |
1068 | size_t path_len; | |
1069 | git_buf buf = GIT_BUF_INIT; | |
1070 | ||
1071 | path_len = strlen(path); | |
1072 | ||
1073 | if (path_len < strlen(".idx")) | |
e10144ae | 1074 | return git_odb__error_notfound("invalid packfile path", NULL, 0); |
b3b66c57 CMN |
1075 | |
1076 | if (git_buf_printf(&buf, "%.*s.pack", (int)(path_len - strlen(".idx")), path) < 0) | |
1077 | return -1; | |
1078 | ||
1079 | *out = git_buf_detach(&buf); | |
1080 | return 0; | |
1081 | } | |
1082 | ||
5d2d21e5 | 1083 | int git_packfile_alloc(struct git_pack_file **pack_out, const char *path) |
a070f152 CMN |
1084 | { |
1085 | struct stat st; | |
1086 | struct git_pack_file *p; | |
f1453c59 | 1087 | size_t path_len = path ? strlen(path) : 0, alloc_len; |
a070f152 CMN |
1088 | |
1089 | *pack_out = NULL; | |
24c70804 | 1090 | |
38eef611 | 1091 | if (path_len < strlen(".idx")) |
e10144ae | 1092 | return git_odb__error_notfound("invalid packfile path", NULL, 0); |
24c70804 | 1093 | |
ac3d33df JK |
1094 | GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, sizeof(*p), path_len); |
1095 | GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 2); | |
392702ee | 1096 | |
f1453c59 | 1097 | p = git__calloc(1, alloc_len); |
ac3d33df | 1098 | GIT_ERROR_CHECK_ALLOC(p); |
a070f152 | 1099 | |
38eef611 RB |
1100 | memcpy(p->pack_name, path, path_len + 1); |
1101 | ||
a070f152 CMN |
1102 | /* |
1103 | * Make sure a corresponding .pack file exists and that | |
1104 | * the index looks sane. | |
1105 | */ | |
38eef611 RB |
1106 | if (git__suffixcmp(path, ".idx") == 0) { |
1107 | size_t root_len = path_len - strlen(".idx"); | |
1108 | ||
0c9c969a UG |
1109 | if (!git_disable_pack_keep_file_checks) { |
1110 | memcpy(p->pack_name + root_len, ".keep", sizeof(".keep")); | |
1111 | if (git_path_exists(p->pack_name) == true) | |
1112 | p->pack_keep = 1; | |
1113 | } | |
a070f152 | 1114 | |
38eef611 | 1115 | memcpy(p->pack_name + root_len, ".pack", sizeof(".pack")); |
38eef611 | 1116 | } |
a070f152 | 1117 | |
e1de726c | 1118 | if (p_stat(p->pack_name, &st) < 0 || !S_ISREG(st.st_mode)) { |
3286c408 | 1119 | git__free(p); |
e10144ae | 1120 | return git_odb__error_notfound("packfile not found", NULL, 0); |
a070f152 CMN |
1121 | } |
1122 | ||
1123 | /* ok, it looks sane as far as we can check without | |
1124 | * actually mapping the pack file. | |
1125 | */ | |
38eef611 | 1126 | p->mwf.fd = -1; |
1af56d7d | 1127 | p->mwf.size = st.st_size; |
a070f152 CMN |
1128 | p->pack_local = 1; |
1129 | p->mtime = (git_time_t)st.st_mtime; | |
0ddfcb40 | 1130 | p->index_version = -1; |
a070f152 | 1131 | |
1a42dd17 | 1132 | if (git_mutex_init(&p->lock)) { |
ac3d33df | 1133 | git_error_set(GIT_ERROR_OS, "failed to initialize packfile mutex"); |
1a42dd17 RB |
1134 | git__free(p); |
1135 | return -1; | |
1136 | } | |
38eef611 | 1137 | |
649214be CMN |
1138 | if (cache_init(&p->bases) < 0) { |
1139 | git__free(p); | |
1140 | return -1; | |
1141 | } | |
1142 | ||
a070f152 | 1143 | *pack_out = p; |
e1de726c RB |
1144 | |
1145 | return 0; | |
a070f152 CMN |
1146 | } |
1147 | ||
1148 | /*********************************************************** | |
1149 | * | |
1150 | * PACKFILE ENTRY SEARCH INTERNALS | |
1151 | * | |
1152 | ***********************************************************/ | |
1153 | ||
0c9c969a | 1154 | static off64_t nth_packed_object_offset(const struct git_pack_file *p, uint32_t n) |
a070f152 CMN |
1155 | { |
1156 | const unsigned char *index = p->index_map.data; | |
ea9e00cb | 1157 | const unsigned char *end = index + p->index_map.len; |
a070f152 CMN |
1158 | index += 4 * 256; |
1159 | if (p->index_version == 1) { | |
1160 | return ntohl(*((uint32_t *)(index + 24 * n))); | |
1161 | } else { | |
1162 | uint32_t off; | |
1163 | index += 8 + p->num_objects * (20 + 4); | |
1164 | off = ntohl(*((uint32_t *)(index + 4 * n))); | |
1165 | if (!(off & 0x80000000)) | |
1166 | return off; | |
1167 | index += p->num_objects * 4 + (off & 0x7fffffff) * 8; | |
ea9e00cb CMN |
1168 | |
1169 | /* Make sure we're not being sent out of bounds */ | |
1170 | if (index >= end - 8) | |
1171 | return -1; | |
1172 | ||
a070f152 | 1173 | return (((uint64_t)ntohl(*((uint32_t *)(index + 0)))) << 32) | |
87d9869f | 1174 | ntohl(*((uint32_t *)(index + 4))); |
a070f152 CMN |
1175 | } |
1176 | } | |
1177 | ||
60ecdf59 DMB |
1178 | static int git__memcmp4(const void *a, const void *b) { |
1179 | return memcmp(a, b, 4); | |
1180 | } | |
1181 | ||
521aedad | 1182 | int git_pack_foreach_entry( |
5dca2010 | 1183 | struct git_pack_file *p, |
c3fb7d04 | 1184 | git_odb_foreach_cb cb, |
5dca2010 | 1185 | void *data) |
521aedad CMN |
1186 | { |
1187 | const unsigned char *index = p->index_map.data, *current; | |
521aedad | 1188 | uint32_t i; |
dab89f9b | 1189 | int error = 0; |
521aedad CMN |
1190 | |
1191 | if (index == NULL) { | |
521aedad CMN |
1192 | if ((error = pack_index_open(p)) < 0) |
1193 | return error; | |
1194 | ||
1195 | assert(p->index_map.data); | |
1196 | ||
1197 | index = p->index_map.data; | |
1198 | } | |
1199 | ||
1200 | if (p->index_version > 1) { | |
1201 | index += 8; | |
1202 | } | |
1203 | ||
1204 | index += 4 * 256; | |
1205 | ||
60ecdf59 DMB |
1206 | if (p->oids == NULL) { |
1207 | git_vector offsets, oids; | |
521aedad | 1208 | |
60ecdf59 DMB |
1209 | if ((error = git_vector_init(&oids, p->num_objects, NULL))) |
1210 | return error; | |
1211 | ||
1212 | if ((error = git_vector_init(&offsets, p->num_objects, git__memcmp4))) | |
1213 | return error; | |
5dca2010 | 1214 | |
60ecdf59 DMB |
1215 | if (p->index_version > 1) { |
1216 | const unsigned char *off = index + 24 * p->num_objects; | |
1217 | for (i = 0; i < p->num_objects; i++) | |
1218 | git_vector_insert(&offsets, (void*)&off[4 * i]); | |
1219 | git_vector_sort(&offsets); | |
1220 | git_vector_foreach(&offsets, i, current) | |
1221 | git_vector_insert(&oids, (void*)&index[5 * (current - off)]); | |
1222 | } else { | |
1223 | for (i = 0; i < p->num_objects; i++) | |
1224 | git_vector_insert(&offsets, (void*)&index[24 * i]); | |
1225 | git_vector_sort(&offsets); | |
1226 | git_vector_foreach(&offsets, i, current) | |
1227 | git_vector_insert(&oids, (void*)¤t[4]); | |
1228 | } | |
25e0b157 | 1229 | |
60ecdf59 | 1230 | git_vector_free(&offsets); |
25e0b157 | 1231 | p->oids = (git_oid **)git_vector_detach(NULL, NULL, &oids); |
521aedad CMN |
1232 | } |
1233 | ||
60ecdf59 | 1234 | for (i = 0; i < p->num_objects; i++) |
26c1cb91 | 1235 | if ((error = cb(p->oids[i], data)) != 0) |
ac3d33df | 1236 | return git_error_set_after_callback(error); |
60ecdf59 | 1237 | |
25e0b157 | 1238 | return error; |
521aedad CMN |
1239 | } |
1240 | ||
66a70851 UG |
1241 | static int sha1_position(const void *table, size_t stride, unsigned lo, |
1242 | unsigned hi, const unsigned char *key) | |
1243 | { | |
1244 | const unsigned char *base = table; | |
1245 | ||
1246 | while (lo < hi) { | |
1247 | unsigned mi = (lo + hi) / 2; | |
1248 | int cmp = git_oid__hashcmp(base + mi * stride, key); | |
1249 | ||
1250 | if (!cmp) | |
1251 | return mi; | |
1252 | ||
1253 | if (cmp > 0) | |
1254 | hi = mi; | |
1255 | else | |
1256 | lo = mi+1; | |
1257 | } | |
1258 | ||
1259 | return -((int)lo)-1; | |
1260 | } | |
1261 | ||
a070f152 | 1262 | static int pack_entry_find_offset( |
0c9c969a | 1263 | off64_t *offset_out, |
e1de726c RB |
1264 | git_oid *found_oid, |
1265 | struct git_pack_file *p, | |
1266 | const git_oid *short_oid, | |
b8457baa | 1267 | size_t len) |
a070f152 | 1268 | { |
0cf15e39 PS |
1269 | const uint32_t *level1_ofs; |
1270 | const unsigned char *index; | |
a070f152 CMN |
1271 | unsigned hi, lo, stride; |
1272 | int pos, found = 0; | |
0c9c969a | 1273 | off64_t offset; |
a070f152 CMN |
1274 | const unsigned char *current = 0; |
1275 | ||
1276 | *offset_out = 0; | |
1277 | ||
0ddfcb40 | 1278 | if (p->index_version == -1) { |
34bd5999 | 1279 | int error; |
a070f152 | 1280 | |
34bd5999 CMN |
1281 | if ((error = pack_index_open(p)) < 0) |
1282 | return error; | |
1283 | assert(p->index_map.data); | |
34bd5999 | 1284 | } |
a070f152 | 1285 | |
0cf15e39 PS |
1286 | index = p->index_map.data; |
1287 | level1_ofs = p->index_map.data; | |
1288 | ||
a070f152 CMN |
1289 | if (p->index_version > 1) { |
1290 | level1_ofs += 2; | |
1291 | index += 8; | |
1292 | } | |
1293 | ||
1294 | index += 4 * 256; | |
1295 | hi = ntohl(level1_ofs[(int)short_oid->id[0]]); | |
1296 | lo = ((short_oid->id[0] == 0x0) ? 0 : ntohl(level1_ofs[(int)short_oid->id[0] - 1])); | |
1297 | ||
1298 | if (p->index_version > 1) { | |
1299 | stride = 20; | |
1300 | } else { | |
1301 | stride = 24; | |
1302 | index += 4; | |
1303 | } | |
1304 | ||
1305 | #ifdef INDEX_DEBUG_LOOKUP | |
1306 | printf("%02x%02x%02x... lo %u hi %u nr %d\n", | |
1307 | short_oid->id[0], short_oid->id[1], short_oid->id[2], lo, hi, p->num_objects); | |
1308 | #endif | |
1309 | ||
67591c8c | 1310 | pos = sha1_position(index, stride, lo, hi, short_oid->id); |
a070f152 CMN |
1311 | |
1312 | if (pos >= 0) { | |
1313 | /* An object matching exactly the oid was found */ | |
1314 | found = 1; | |
1315 | current = index + pos * stride; | |
1316 | } else { | |
1317 | /* No object was found */ | |
1318 | /* pos refers to the object with the "closest" oid to short_oid */ | |
1319 | pos = - 1 - pos; | |
1320 | if (pos < (int)p->num_objects) { | |
1321 | current = index + pos * stride; | |
1322 | ||
282283ac | 1323 | if (!git_oid_ncmp(short_oid, (const git_oid *)current, len)) |
a070f152 | 1324 | found = 1; |
a070f152 CMN |
1325 | } |
1326 | } | |
1327 | ||
b2a2702d | 1328 | if (found && len != GIT_OID_HEXSZ && pos + 1 < (int)p->num_objects) { |
a070f152 CMN |
1329 | /* Check for ambiguousity */ |
1330 | const unsigned char *next = current + stride; | |
1331 | ||
1332 | if (!git_oid_ncmp(short_oid, (const git_oid *)next, len)) { | |
1333 | found = 2; | |
1334 | } | |
1335 | } | |
1336 | ||
e1de726c | 1337 | if (!found) |
e10144ae | 1338 | return git_odb__error_notfound("failed to find offset for pack entry", short_oid, len); |
e1de726c RB |
1339 | if (found > 1) |
1340 | return git_odb__error_ambiguous("found multiple offsets for pack entry"); | |
24c70804 | 1341 | |
ea9e00cb | 1342 | if ((offset = nth_packed_object_offset(p, pos)) < 0) { |
ac3d33df | 1343 | git_error_set(GIT_ERROR_ODB, "packfile index is corrupt"); |
ea9e00cb CMN |
1344 | return -1; |
1345 | } | |
1346 | ||
1347 | *offset_out = offset; | |
e1de726c | 1348 | git_oid_fromraw(found_oid, current); |
a070f152 CMN |
1349 | |
1350 | #ifdef INDEX_DEBUG_LOOKUP | |
e1de726c | 1351 | { |
a070f152 CMN |
1352 | unsigned char hex_sha1[GIT_OID_HEXSZ + 1]; |
1353 | git_oid_fmt(hex_sha1, found_oid); | |
1354 | hex_sha1[GIT_OID_HEXSZ] = '\0'; | |
1355 | printf("found lo=%d %s\n", lo, hex_sha1); | |
a070f152 | 1356 | } |
e1de726c | 1357 | #endif |
24c70804 | 1358 | |
e1de726c | 1359 | return 0; |
a070f152 CMN |
1360 | } |
1361 | ||
1362 | int git_pack_entry_find( | |
1363 | struct git_pack_entry *e, | |
1364 | struct git_pack_file *p, | |
1365 | const git_oid *short_oid, | |
b8457baa | 1366 | size_t len) |
a070f152 | 1367 | { |
0c9c969a | 1368 | off64_t offset; |
a070f152 CMN |
1369 | git_oid found_oid; |
1370 | int error; | |
1371 | ||
1372 | assert(p); | |
1373 | ||
1374 | if (len == GIT_OID_HEXSZ && p->num_bad_objects) { | |
1375 | unsigned i; | |
1376 | for (i = 0; i < p->num_bad_objects; i++) | |
b7f167da | 1377 | if (git_oid__cmp(short_oid, &p->bad_object_sha1[i]) == 0) |
e1de726c | 1378 | return packfile_error("bad object found in packfile"); |
a070f152 CMN |
1379 | } |
1380 | ||
1381 | error = pack_entry_find_offset(&offset, &found_oid, p, short_oid, len); | |
e1de726c RB |
1382 | if (error < 0) |
1383 | return error; | |
a070f152 CMN |
1384 | |
1385 | /* we found a unique entry in the index; | |
1386 | * make sure the packfile backing the index | |
1387 | * still exists on disk */ | |
e1de726c RB |
1388 | if (p->mwf.fd == -1 && (error = packfile_open(p)) < 0) |
1389 | return error; | |
a070f152 CMN |
1390 | |
1391 | e->offset = offset; | |
1392 | e->p = p; | |
1393 | ||
1394 | git_oid_cpy(&e->sha1, &found_oid); | |
e1de726c | 1395 | return 0; |
a070f152 | 1396 | } |