1#include"../cache.h" 2#include"../refs.h" 3#include"refs-internal.h" 4#include"../iterator.h" 5#include"../dir-iterator.h" 6#include"../lockfile.h" 7#include"../object.h" 8#include"../dir.h" 9 10struct ref_lock { 11char*ref_name; 12struct lock_file *lk; 13struct object_id old_oid; 14}; 15 16struct ref_entry; 17 18/* 19 * Information used (along with the information in ref_entry) to 20 * describe a single cached reference. This data structure only 21 * occurs embedded in a union in struct ref_entry, and only when 22 * (ref_entry->flag & REF_DIR) is zero. 23 */ 24struct ref_value { 25/* 26 * The name of the object to which this reference resolves 27 * (which may be a tag object). If REF_ISBROKEN, this is 28 * null. If REF_ISSYMREF, then this is the name of the object 29 * referred to by the last reference in the symlink chain. 30 */ 31struct object_id oid; 32 33/* 34 * If REF_KNOWS_PEELED, then this field holds the peeled value 35 * of this reference, or null if the reference is known not to 36 * be peelable. See the documentation for peel_ref() for an 37 * exact definition of "peelable". 38 */ 39struct object_id peeled; 40}; 41 42struct files_ref_store; 43 44/* 45 * Information used (along with the information in ref_entry) to 46 * describe a level in the hierarchy of references. This data 47 * structure only occurs embedded in a union in struct ref_entry, and 48 * only when (ref_entry.flag & REF_DIR) is set. In that case, 49 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 50 * in the directory have already been read: 51 * 52 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 53 * or packed references, already read. 54 * 55 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 56 * references that hasn't been read yet (nor has any of its 57 * subdirectories). 58 * 59 * Entries within a directory are stored within a growable array of 60 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 61 * sorted are sorted by their component name in strcmp() order and the 62 * remaining entries are unsorted. 63 * 64 * Loose references are read lazily, one directory at a time. When a 65 * directory of loose references is read, then all of the references 66 * in that directory are stored, and REF_INCOMPLETE stubs are created 67 * for any subdirectories, but the subdirectories themselves are not 68 * read. The reading is triggered by get_ref_dir(). 69 */ 70struct ref_dir { 71int nr, alloc; 72 73/* 74 * Entries with index 0 <= i < sorted are sorted by name. New 75 * entries are appended to the list unsorted, and are sorted 76 * only when required; thus we avoid the need to sort the list 77 * after the addition of every reference. 78 */ 79int sorted; 80 81/* A pointer to the files_ref_store that contains this ref_dir. */ 82struct files_ref_store *ref_store; 83 84struct ref_entry **entries; 85}; 86 87/* 88 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 89 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 90 * public values; see refs.h. 91 */ 92 93/* 94 * The field ref_entry->u.value.peeled of this value entry contains 95 * the correct peeled value for the reference, which might be 96 * null_sha1 if the reference is not a tag or if it is broken. 97 */ 98#define REF_KNOWS_PEELED 0x10 99 100/* ref_entry represents a directory of references */ 101#define REF_DIR 0x20 102 103/* 104 * Entry has not yet been read from disk (used only for REF_DIR 105 * entries representing loose references) 106 */ 107#define REF_INCOMPLETE 0x40 108 109/* 110 * A ref_entry represents either a reference or a "subdirectory" of 111 * references. 112 * 113 * Each directory in the reference namespace is represented by a 114 * ref_entry with (flags & REF_DIR) set and containing a subdir member 115 * that holds the entries in that directory that have been read so 116 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 117 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 118 * used for loose reference directories. 119 * 120 * References are represented by a ref_entry with (flags & REF_DIR) 121 * unset and a value member that describes the reference's value. The 122 * flag member is at the ref_entry level, but it is also needed to 123 * interpret the contents of the value field (in other words, a 124 * ref_value object is not very much use without the enclosing 125 * ref_entry). 126 * 127 * Reference names cannot end with slash and directories' names are 128 * always stored with a trailing slash (except for the top-level 129 * directory, which is always denoted by ""). This has two nice 130 * consequences: (1) when the entries in each subdir are sorted 131 * lexicographically by name (as they usually are), the references in 132 * a whole tree can be generated in lexicographic order by traversing 133 * the tree in left-to-right, depth-first order; (2) the names of 134 * references and subdirectories cannot conflict, and therefore the 135 * presence of an empty subdirectory does not block the creation of a 136 * similarly-named reference. (The fact that reference names with the 137 * same leading components can conflict *with each other* is a 138 * separate issue that is regulated by verify_refname_available().) 139 * 140 * Please note that the name field contains the fully-qualified 141 * reference (or subdirectory) name. Space could be saved by only 142 * storing the relative names. But that would require the full names 143 * to be generated on the fly when iterating in do_for_each_ref(), and 144 * would break callback functions, who have always been able to assume 145 * that the name strings that they are passed will not be freed during 146 * the iteration. 147 */ 148struct ref_entry { 149unsigned char flag;/* ISSYMREF? ISPACKED? */ 150union{ 151struct ref_value value;/* if not (flags&REF_DIR) */ 152struct ref_dir subdir;/* if (flags&REF_DIR) */ 153} u; 154/* 155 * The full name of the reference (e.g., "refs/heads/master") 156 * or the full name of the directory with a trailing slash 157 * (e.g., "refs/heads/"): 158 */ 159char name[FLEX_ARRAY]; 160}; 161 162static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 163static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len); 164static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 165const char*dirname,size_t len, 166int incomplete); 167static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry); 168 169static struct ref_dir *get_ref_dir(struct ref_entry *entry) 170{ 171struct ref_dir *dir; 172assert(entry->flag & REF_DIR); 173 dir = &entry->u.subdir; 174if(entry->flag & REF_INCOMPLETE) { 175read_loose_refs(entry->name, dir); 176 177/* 178 * Manually add refs/bisect, which, being 179 * per-worktree, might not appear in the directory 180 * listing for refs/ in the main repo. 181 */ 182if(!strcmp(entry->name,"refs/")) { 183int pos =search_ref_dir(dir,"refs/bisect/",12); 184if(pos <0) { 185struct ref_entry *child_entry; 186 child_entry =create_dir_entry(dir->ref_store, 187"refs/bisect/", 18812,1); 189add_entry_to_dir(dir, child_entry); 190read_loose_refs("refs/bisect", 191&child_entry->u.subdir); 192} 193} 194 entry->flag &= ~REF_INCOMPLETE; 195} 196return dir; 197} 198 199static struct ref_entry *create_ref_entry(const char*refname, 200const unsigned char*sha1,int flag, 201int check_name) 202{ 203struct ref_entry *ref; 204 205if(check_name && 206check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 207die("Reference has invalid format: '%s'", refname); 208FLEX_ALLOC_STR(ref, name, refname); 209hashcpy(ref->u.value.oid.hash, sha1); 210oidclr(&ref->u.value.peeled); 211 ref->flag = flag; 212return ref; 213} 214 215static voidclear_ref_dir(struct ref_dir *dir); 216 217static voidfree_ref_entry(struct ref_entry *entry) 218{ 219if(entry->flag & REF_DIR) { 220/* 221 * Do not use get_ref_dir() here, as that might 222 * trigger the reading of loose refs. 223 */ 224clear_ref_dir(&entry->u.subdir); 225} 226free(entry); 227} 228 229/* 230 * Add a ref_entry to the end of dir (unsorted). Entry is always 231 * stored directly in dir; no recursion into subdirectories is 232 * done. 233 */ 234static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 235{ 236ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 237 dir->entries[dir->nr++] = entry; 238/* optimize for the case that entries are added in order */ 239if(dir->nr ==1|| 240(dir->nr == dir->sorted +1&& 241strcmp(dir->entries[dir->nr -2]->name, 242 dir->entries[dir->nr -1]->name) <0)) 243 dir->sorted = dir->nr; 244} 245 246/* 247 * Clear and free all entries in dir, recursively. 248 */ 249static voidclear_ref_dir(struct ref_dir *dir) 250{ 251int i; 252for(i =0; i < dir->nr; i++) 253free_ref_entry(dir->entries[i]); 254free(dir->entries); 255 dir->sorted = dir->nr = dir->alloc =0; 256 dir->entries = NULL; 257} 258 259/* 260 * Create a struct ref_entry object for the specified dirname. 261 * dirname is the name of the directory with a trailing slash (e.g., 262 * "refs/heads/") or "" for the top-level directory. 263 */ 264static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 265const char*dirname,size_t len, 266int incomplete) 267{ 268struct ref_entry *direntry; 269FLEX_ALLOC_MEM(direntry, name, dirname, len); 270 direntry->u.subdir.ref_store = ref_store; 271 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 272return direntry; 273} 274 275static intref_entry_cmp(const void*a,const void*b) 276{ 277struct ref_entry *one = *(struct ref_entry **)a; 278struct ref_entry *two = *(struct ref_entry **)b; 279returnstrcmp(one->name, two->name); 280} 281 282static voidsort_ref_dir(struct ref_dir *dir); 283 284struct string_slice { 285size_t len; 286const char*str; 287}; 288 289static intref_entry_cmp_sslice(const void*key_,const void*ent_) 290{ 291const struct string_slice *key = key_; 292const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 293int cmp =strncmp(key->str, ent->name, key->len); 294if(cmp) 295return cmp; 296return'\0'- (unsigned char)ent->name[key->len]; 297} 298 299/* 300 * Return the index of the entry with the given refname from the 301 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 302 * no such entry is found. dir must already be complete. 303 */ 304static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 305{ 306struct ref_entry **r; 307struct string_slice key; 308 309if(refname == NULL || !dir->nr) 310return-1; 311 312sort_ref_dir(dir); 313 key.len = len; 314 key.str = refname; 315 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 316 ref_entry_cmp_sslice); 317 318if(r == NULL) 319return-1; 320 321return r - dir->entries; 322} 323 324/* 325 * Search for a directory entry directly within dir (without 326 * recursing). Sort dir if necessary. subdirname must be a directory 327 * name (i.e., end in '/'). If mkdir is set, then create the 328 * directory if it is missing; otherwise, return NULL if the desired 329 * directory cannot be found. dir must already be complete. 330 */ 331static struct ref_dir *search_for_subdir(struct ref_dir *dir, 332const char*subdirname,size_t len, 333int mkdir) 334{ 335int entry_index =search_ref_dir(dir, subdirname, len); 336struct ref_entry *entry; 337if(entry_index == -1) { 338if(!mkdir) 339return NULL; 340/* 341 * Since dir is complete, the absence of a subdir 342 * means that the subdir really doesn't exist; 343 * therefore, create an empty record for it but mark 344 * the record complete. 345 */ 346 entry =create_dir_entry(dir->ref_store, subdirname, len,0); 347add_entry_to_dir(dir, entry); 348}else{ 349 entry = dir->entries[entry_index]; 350} 351returnget_ref_dir(entry); 352} 353 354/* 355 * If refname is a reference name, find the ref_dir within the dir 356 * tree that should hold refname. If refname is a directory name 357 * (i.e., ends in '/'), then return that ref_dir itself. dir must 358 * represent the top-level directory and must already be complete. 359 * Sort ref_dirs and recurse into subdirectories as necessary. If 360 * mkdir is set, then create any missing directories; otherwise, 361 * return NULL if the desired directory cannot be found. 362 */ 363static struct ref_dir *find_containing_dir(struct ref_dir *dir, 364const char*refname,int mkdir) 365{ 366const char*slash; 367for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 368size_t dirnamelen = slash - refname +1; 369struct ref_dir *subdir; 370 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 371if(!subdir) { 372 dir = NULL; 373break; 374} 375 dir = subdir; 376} 377 378return dir; 379} 380 381/* 382 * Find the value entry with the given name in dir, sorting ref_dirs 383 * and recursing into subdirectories as necessary. If the name is not 384 * found or it corresponds to a directory entry, return NULL. 385 */ 386static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 387{ 388int entry_index; 389struct ref_entry *entry; 390 dir =find_containing_dir(dir, refname,0); 391if(!dir) 392return NULL; 393 entry_index =search_ref_dir(dir, refname,strlen(refname)); 394if(entry_index == -1) 395return NULL; 396 entry = dir->entries[entry_index]; 397return(entry->flag & REF_DIR) ? NULL : entry; 398} 399 400/* 401 * Remove the entry with the given name from dir, recursing into 402 * subdirectories as necessary. If refname is the name of a directory 403 * (i.e., ends with '/'), then remove the directory and its contents. 404 * If the removal was successful, return the number of entries 405 * remaining in the directory entry that contained the deleted entry. 406 * If the name was not found, return -1. Please note that this 407 * function only deletes the entry from the cache; it does not delete 408 * it from the filesystem or ensure that other cache entries (which 409 * might be symbolic references to the removed entry) are updated. 410 * Nor does it remove any containing dir entries that might be made 411 * empty by the removal. dir must represent the top-level directory 412 * and must already be complete. 413 */ 414static intremove_entry(struct ref_dir *dir,const char*refname) 415{ 416int refname_len =strlen(refname); 417int entry_index; 418struct ref_entry *entry; 419int is_dir = refname[refname_len -1] =='/'; 420if(is_dir) { 421/* 422 * refname represents a reference directory. Remove 423 * the trailing slash; otherwise we will get the 424 * directory *representing* refname rather than the 425 * one *containing* it. 426 */ 427char*dirname =xmemdupz(refname, refname_len -1); 428 dir =find_containing_dir(dir, dirname,0); 429free(dirname); 430}else{ 431 dir =find_containing_dir(dir, refname,0); 432} 433if(!dir) 434return-1; 435 entry_index =search_ref_dir(dir, refname, refname_len); 436if(entry_index == -1) 437return-1; 438 entry = dir->entries[entry_index]; 439 440memmove(&dir->entries[entry_index], 441&dir->entries[entry_index +1], 442(dir->nr - entry_index -1) *sizeof(*dir->entries) 443); 444 dir->nr--; 445if(dir->sorted > entry_index) 446 dir->sorted--; 447free_ref_entry(entry); 448return dir->nr; 449} 450 451/* 452 * Add a ref_entry to the ref_dir (unsorted), recursing into 453 * subdirectories as necessary. dir must represent the top-level 454 * directory. Return 0 on success. 455 */ 456static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 457{ 458 dir =find_containing_dir(dir, ref->name,1); 459if(!dir) 460return-1; 461add_entry_to_dir(dir, ref); 462return0; 463} 464 465/* 466 * Emit a warning and return true iff ref1 and ref2 have the same name 467 * and the same sha1. Die if they have the same name but different 468 * sha1s. 469 */ 470static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 471{ 472if(strcmp(ref1->name, ref2->name)) 473return0; 474 475/* Duplicate name; make sure that they don't conflict: */ 476 477if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 478/* This is impossible by construction */ 479die("Reference directory conflict:%s", ref1->name); 480 481if(oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) 482die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 483 484warning("Duplicated ref:%s", ref1->name); 485return1; 486} 487 488/* 489 * Sort the entries in dir non-recursively (if they are not already 490 * sorted) and remove any duplicate entries. 491 */ 492static voidsort_ref_dir(struct ref_dir *dir) 493{ 494int i, j; 495struct ref_entry *last = NULL; 496 497/* 498 * This check also prevents passing a zero-length array to qsort(), 499 * which is a problem on some platforms. 500 */ 501if(dir->sorted == dir->nr) 502return; 503 504QSORT(dir->entries, dir->nr, ref_entry_cmp); 505 506/* Remove any duplicates: */ 507for(i =0, j =0; j < dir->nr; j++) { 508struct ref_entry *entry = dir->entries[j]; 509if(last &&is_dup_ref(last, entry)) 510free_ref_entry(entry); 511else 512 last = dir->entries[i++] = entry; 513} 514 dir->sorted = dir->nr = i; 515} 516 517/* 518 * Return true if refname, which has the specified oid and flags, can 519 * be resolved to an object in the database. If the referred-to object 520 * does not exist, emit a warning and return false. 521 */ 522static intref_resolves_to_object(const char*refname, 523const struct object_id *oid, 524unsigned int flags) 525{ 526if(flags & REF_ISBROKEN) 527return0; 528if(!has_sha1_file(oid->hash)) { 529error("%sdoes not point to a valid object!", refname); 530return0; 531} 532return1; 533} 534 535/* 536 * Return true if the reference described by entry can be resolved to 537 * an object in the database; otherwise, emit a warning and return 538 * false. 539 */ 540static intentry_resolves_to_object(struct ref_entry *entry) 541{ 542returnref_resolves_to_object(entry->name, 543&entry->u.value.oid, entry->flag); 544} 545 546typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 547 548/* 549 * Call fn for each reference in dir that has index in the range 550 * offset <= index < dir->nr. Recurse into subdirectories that are in 551 * that index range, sorting them before iterating. This function 552 * does not sort dir itself; it should be sorted beforehand. fn is 553 * called for all references, including broken ones. 554 */ 555static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 556 each_ref_entry_fn fn,void*cb_data) 557{ 558int i; 559assert(dir->sorted == dir->nr); 560for(i = offset; i < dir->nr; i++) { 561struct ref_entry *entry = dir->entries[i]; 562int retval; 563if(entry->flag & REF_DIR) { 564struct ref_dir *subdir =get_ref_dir(entry); 565sort_ref_dir(subdir); 566 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 567}else{ 568 retval =fn(entry, cb_data); 569} 570if(retval) 571return retval; 572} 573return0; 574} 575 576/* 577 * Load all of the refs from the dir into our in-memory cache. The hard work 578 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 579 * through all of the sub-directories. We do not even need to care about 580 * sorting, as traversal order does not matter to us. 581 */ 582static voidprime_ref_dir(struct ref_dir *dir) 583{ 584int i; 585for(i =0; i < dir->nr; i++) { 586struct ref_entry *entry = dir->entries[i]; 587if(entry->flag & REF_DIR) 588prime_ref_dir(get_ref_dir(entry)); 589} 590} 591 592/* 593 * A level in the reference hierarchy that is currently being iterated 594 * through. 595 */ 596struct cache_ref_iterator_level { 597/* 598 * The ref_dir being iterated over at this level. The ref_dir 599 * is sorted before being stored here. 600 */ 601struct ref_dir *dir; 602 603/* 604 * The index of the current entry within dir (which might 605 * itself be a directory). If index == -1, then the iteration 606 * hasn't yet begun. If index == dir->nr, then the iteration 607 * through this level is over. 608 */ 609int index; 610}; 611 612/* 613 * Represent an iteration through a ref_dir in the memory cache. The 614 * iteration recurses through subdirectories. 615 */ 616struct cache_ref_iterator { 617struct ref_iterator base; 618 619/* 620 * The number of levels currently on the stack. This is always 621 * at least 1, because when it becomes zero the iteration is 622 * ended and this struct is freed. 623 */ 624size_t levels_nr; 625 626/* The number of levels that have been allocated on the stack */ 627size_t levels_alloc; 628 629/* 630 * A stack of levels. levels[0] is the uppermost level that is 631 * being iterated over in this iteration. (This is not 632 * necessary the top level in the references hierarchy. If we 633 * are iterating through a subtree, then levels[0] will hold 634 * the ref_dir for that subtree, and subsequent levels will go 635 * on from there.) 636 */ 637struct cache_ref_iterator_level *levels; 638}; 639 640static intcache_ref_iterator_advance(struct ref_iterator *ref_iterator) 641{ 642struct cache_ref_iterator *iter = 643(struct cache_ref_iterator *)ref_iterator; 644 645while(1) { 646struct cache_ref_iterator_level *level = 647&iter->levels[iter->levels_nr -1]; 648struct ref_dir *dir = level->dir; 649struct ref_entry *entry; 650 651if(level->index == -1) 652sort_ref_dir(dir); 653 654if(++level->index == level->dir->nr) { 655/* This level is exhausted; pop up a level */ 656if(--iter->levels_nr ==0) 657returnref_iterator_abort(ref_iterator); 658 659continue; 660} 661 662 entry = dir->entries[level->index]; 663 664if(entry->flag & REF_DIR) { 665/* push down a level */ 666ALLOC_GROW(iter->levels, iter->levels_nr +1, 667 iter->levels_alloc); 668 669 level = &iter->levels[iter->levels_nr++]; 670 level->dir =get_ref_dir(entry); 671 level->index = -1; 672}else{ 673 iter->base.refname = entry->name; 674 iter->base.oid = &entry->u.value.oid; 675 iter->base.flags = entry->flag; 676return ITER_OK; 677} 678} 679} 680 681static enum peel_status peel_entry(struct ref_entry *entry,int repeel); 682 683static intcache_ref_iterator_peel(struct ref_iterator *ref_iterator, 684struct object_id *peeled) 685{ 686struct cache_ref_iterator *iter = 687(struct cache_ref_iterator *)ref_iterator; 688struct cache_ref_iterator_level *level; 689struct ref_entry *entry; 690 691 level = &iter->levels[iter->levels_nr -1]; 692 693if(level->index == -1) 694die("BUG: peel called before advance for cache iterator"); 695 696 entry = level->dir->entries[level->index]; 697 698if(peel_entry(entry,0)) 699return-1; 700hashcpy(peeled->hash, entry->u.value.peeled.hash); 701return0; 702} 703 704static intcache_ref_iterator_abort(struct ref_iterator *ref_iterator) 705{ 706struct cache_ref_iterator *iter = 707(struct cache_ref_iterator *)ref_iterator; 708 709free(iter->levels); 710base_ref_iterator_free(ref_iterator); 711return ITER_DONE; 712} 713 714static struct ref_iterator_vtable cache_ref_iterator_vtable = { 715 cache_ref_iterator_advance, 716 cache_ref_iterator_peel, 717 cache_ref_iterator_abort 718}; 719 720static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir) 721{ 722struct cache_ref_iterator *iter; 723struct ref_iterator *ref_iterator; 724struct cache_ref_iterator_level *level; 725 726 iter =xcalloc(1,sizeof(*iter)); 727 ref_iterator = &iter->base; 728base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable); 729ALLOC_GROW(iter->levels,10, iter->levels_alloc); 730 731 iter->levels_nr =1; 732 level = &iter->levels[0]; 733 level->index = -1; 734 level->dir = dir; 735 736return ref_iterator; 737} 738 739struct nonmatching_ref_data { 740const struct string_list *skip; 741const char*conflicting_refname; 742}; 743 744static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 745{ 746struct nonmatching_ref_data *data = vdata; 747 748if(data->skip &&string_list_has_string(data->skip, entry->name)) 749return0; 750 751 data->conflicting_refname = entry->name; 752return1; 753} 754 755/* 756 * Return 0 if a reference named refname could be created without 757 * conflicting with the name of an existing reference in dir. 758 * See verify_refname_available for more information. 759 */ 760static intverify_refname_available_dir(const char*refname, 761const struct string_list *extras, 762const struct string_list *skip, 763struct ref_dir *dir, 764struct strbuf *err) 765{ 766const char*slash; 767const char*extra_refname; 768int pos; 769struct strbuf dirname = STRBUF_INIT; 770int ret = -1; 771 772/* 773 * For the sake of comments in this function, suppose that 774 * refname is "refs/foo/bar". 775 */ 776 777assert(err); 778 779strbuf_grow(&dirname,strlen(refname) +1); 780for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 781/* Expand dirname to the new prefix, not including the trailing slash: */ 782strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); 783 784/* 785 * We are still at a leading dir of the refname (e.g., 786 * "refs/foo"; if there is a reference with that name, 787 * it is a conflict, *unless* it is in skip. 788 */ 789if(dir) { 790 pos =search_ref_dir(dir, dirname.buf, dirname.len); 791if(pos >=0&& 792(!skip || !string_list_has_string(skip, dirname.buf))) { 793/* 794 * We found a reference whose name is 795 * a proper prefix of refname; e.g., 796 * "refs/foo", and is not in skip. 797 */ 798strbuf_addf(err,"'%s' exists; cannot create '%s'", 799 dirname.buf, refname); 800goto cleanup; 801} 802} 803 804if(extras &&string_list_has_string(extras, dirname.buf) && 805(!skip || !string_list_has_string(skip, dirname.buf))) { 806strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 807 refname, dirname.buf); 808goto cleanup; 809} 810 811/* 812 * Otherwise, we can try to continue our search with 813 * the next component. So try to look up the 814 * directory, e.g., "refs/foo/". If we come up empty, 815 * we know there is nothing under this whole prefix, 816 * but even in that case we still have to continue the 817 * search for conflicts with extras. 818 */ 819strbuf_addch(&dirname,'/'); 820if(dir) { 821 pos =search_ref_dir(dir, dirname.buf, dirname.len); 822if(pos <0) { 823/* 824 * There was no directory "refs/foo/", 825 * so there is nothing under this 826 * whole prefix. So there is no need 827 * to continue looking for conflicting 828 * references. But we need to continue 829 * looking for conflicting extras. 830 */ 831 dir = NULL; 832}else{ 833 dir =get_ref_dir(dir->entries[pos]); 834} 835} 836} 837 838/* 839 * We are at the leaf of our refname (e.g., "refs/foo/bar"). 840 * There is no point in searching for a reference with that 841 * name, because a refname isn't considered to conflict with 842 * itself. But we still need to check for references whose 843 * names are in the "refs/foo/bar/" namespace, because they 844 * *do* conflict. 845 */ 846strbuf_addstr(&dirname, refname + dirname.len); 847strbuf_addch(&dirname,'/'); 848 849if(dir) { 850 pos =search_ref_dir(dir, dirname.buf, dirname.len); 851 852if(pos >=0) { 853/* 854 * We found a directory named "$refname/" 855 * (e.g., "refs/foo/bar/"). It is a problem 856 * iff it contains any ref that is not in 857 * "skip". 858 */ 859struct nonmatching_ref_data data; 860 861 data.skip = skip; 862 data.conflicting_refname = NULL; 863 dir =get_ref_dir(dir->entries[pos]); 864sort_ref_dir(dir); 865if(do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) { 866strbuf_addf(err,"'%s' exists; cannot create '%s'", 867 data.conflicting_refname, refname); 868goto cleanup; 869} 870} 871} 872 873 extra_refname =find_descendant_ref(dirname.buf, extras, skip); 874if(extra_refname) 875strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 876 refname, extra_refname); 877else 878 ret =0; 879 880cleanup: 881strbuf_release(&dirname); 882return ret; 883} 884 885struct packed_ref_cache { 886struct ref_entry *root; 887 888/* 889 * Count of references to the data structure in this instance, 890 * including the pointer from files_ref_store::packed if any. 891 * The data will not be freed as long as the reference count 892 * is nonzero. 893 */ 894unsigned int referrers; 895 896/* 897 * Iff the packed-refs file associated with this instance is 898 * currently locked for writing, this points at the associated 899 * lock (which is owned by somebody else). The referrer count 900 * is also incremented when the file is locked and decremented 901 * when it is unlocked. 902 */ 903struct lock_file *lock; 904 905/* The metadata from when this packed-refs cache was read */ 906struct stat_validity validity; 907}; 908 909/* 910 * Future: need to be in "struct repository" 911 * when doing a full libification. 912 */ 913struct files_ref_store { 914struct ref_store base; 915 916/* 917 * The name of the submodule represented by this object, or 918 * the empty string if it represents the main repository's 919 * reference store: 920 */ 921const char*submodule; 922 923struct ref_entry *loose; 924struct packed_ref_cache *packed; 925}; 926 927/* Lock used for the main packed-refs file: */ 928static struct lock_file packlock; 929 930/* 931 * Increment the reference count of *packed_refs. 932 */ 933static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 934{ 935 packed_refs->referrers++; 936} 937 938/* 939 * Decrease the reference count of *packed_refs. If it goes to zero, 940 * free *packed_refs and return true; otherwise return false. 941 */ 942static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 943{ 944if(!--packed_refs->referrers) { 945free_ref_entry(packed_refs->root); 946stat_validity_clear(&packed_refs->validity); 947free(packed_refs); 948return1; 949}else{ 950return0; 951} 952} 953 954static voidclear_packed_ref_cache(struct files_ref_store *refs) 955{ 956if(refs->packed) { 957struct packed_ref_cache *packed_refs = refs->packed; 958 959if(packed_refs->lock) 960die("internal error: packed-ref cache cleared while locked"); 961 refs->packed = NULL; 962release_packed_ref_cache(packed_refs); 963} 964} 965 966static voidclear_loose_ref_cache(struct files_ref_store *refs) 967{ 968if(refs->loose) { 969free_ref_entry(refs->loose); 970 refs->loose = NULL; 971} 972} 973 974/* 975 * Create a new submodule ref cache and add it to the internal 976 * set of caches. 977 */ 978static struct ref_store *files_ref_store_create(const char*submodule) 979{ 980struct files_ref_store *refs =xcalloc(1,sizeof(*refs)); 981struct ref_store *ref_store = (struct ref_store *)refs; 982 983base_ref_store_init(ref_store, &refs_be_files); 984 985 refs->submodule = submodule ?xstrdup(submodule) :""; 986 987return ref_store; 988} 989 990/* 991 * Die if refs is for a submodule (i.e., not for the main repository). 992 * caller is used in any necessary error messages. 993 */ 994static voidfiles_assert_main_repository(struct files_ref_store *refs, 995const char*caller) 996{ 997if(*refs->submodule) 998die("BUG:%scalled for a submodule", caller); 999}10001001/*1002 * Downcast ref_store to files_ref_store. Die if ref_store is not a1003 * files_ref_store. If submodule_allowed is not true, then also die if1004 * files_ref_store is for a submodule (i.e., not for the main1005 * repository). caller is used in any necessary error messages.1006 */1007static struct files_ref_store *files_downcast(1008struct ref_store *ref_store,int submodule_allowed,1009const char*caller)1010{1011struct files_ref_store *refs;10121013if(ref_store->be != &refs_be_files)1014die("BUG: ref_store is type\"%s\"not\"files\"in%s",1015 ref_store->be->name, caller);10161017 refs = (struct files_ref_store *)ref_store;10181019if(!submodule_allowed)1020files_assert_main_repository(refs, caller);10211022return refs;1023}10241025/* The length of a peeled reference line in packed-refs, including EOL: */1026#define PEELED_LINE_LENGTH 4210271028/*1029 * The packed-refs header line that we write out. Perhaps other1030 * traits will be added later. The trailing space is required.1031 */1032static const char PACKED_REFS_HEADER[] =1033"# pack-refs with: peeled fully-peeled\n";10341035/*1036 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1037 * Return a pointer to the refname within the line (null-terminated),1038 * or NULL if there was a problem.1039 */1040static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1041{1042const char*ref;10431044/*1045 * 42: the answer to everything.1046 *1047 * In this case, it happens to be the answer to1048 * 40 (length of sha1 hex representation)1049 * +1 (space in between hex and name)1050 * +1 (newline at the end of the line)1051 */1052if(line->len <=42)1053return NULL;10541055if(get_sha1_hex(line->buf, sha1) <0)1056return NULL;1057if(!isspace(line->buf[40]))1058return NULL;10591060 ref = line->buf +41;1061if(isspace(*ref))1062return NULL;10631064if(line->buf[line->len -1] !='\n')1065return NULL;1066 line->buf[--line->len] =0;10671068return ref;1069}10701071/*1072 * Read f, which is a packed-refs file, into dir.1073 *1074 * A comment line of the form "# pack-refs with: " may contain zero or1075 * more traits. We interpret the traits as follows:1076 *1077 * No traits:1078 *1079 * Probably no references are peeled. But if the file contains a1080 * peeled value for a reference, we will use it.1081 *1082 * peeled:1083 *1084 * References under "refs/tags/", if they *can* be peeled, *are*1085 * peeled in this file. References outside of "refs/tags/" are1086 * probably not peeled even if they could have been, but if we find1087 * a peeled value for such a reference we will use it.1088 *1089 * fully-peeled:1090 *1091 * All references in the file that can be peeled are peeled.1092 * Inversely (and this is more important), any references in the1093 * file for which no peeled value is recorded is not peelable. This1094 * trait should typically be written alongside "peeled" for1095 * compatibility with older clients, but we do not require it1096 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1097 */1098static voidread_packed_refs(FILE*f,struct ref_dir *dir)1099{1100struct ref_entry *last = NULL;1101struct strbuf line = STRBUF_INIT;1102enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11031104while(strbuf_getwholeline(&line, f,'\n') != EOF) {1105unsigned char sha1[20];1106const char*refname;1107const char*traits;11081109if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1110if(strstr(traits," fully-peeled "))1111 peeled = PEELED_FULLY;1112else if(strstr(traits," peeled "))1113 peeled = PEELED_TAGS;1114/* perhaps other traits later as well */1115continue;1116}11171118 refname =parse_ref_line(&line, sha1);1119if(refname) {1120int flag = REF_ISPACKED;11211122if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1123if(!refname_is_safe(refname))1124die("packed refname is dangerous:%s", refname);1125hashclr(sha1);1126 flag |= REF_BAD_NAME | REF_ISBROKEN;1127}1128 last =create_ref_entry(refname, sha1, flag,0);1129if(peeled == PEELED_FULLY ||1130(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1131 last->flag |= REF_KNOWS_PEELED;1132add_ref(dir, last);1133continue;1134}1135if(last &&1136 line.buf[0] =='^'&&1137 line.len == PEELED_LINE_LENGTH &&1138 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1139!get_sha1_hex(line.buf +1, sha1)) {1140hashcpy(last->u.value.peeled.hash, sha1);1141/*1142 * Regardless of what the file header said,1143 * we definitely know the value of *this*1144 * reference:1145 */1146 last->flag |= REF_KNOWS_PEELED;1147}1148}11491150strbuf_release(&line);1151}11521153/*1154 * Get the packed_ref_cache for the specified files_ref_store,1155 * creating it if necessary.1156 */1157static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1158{1159char*packed_refs_file;11601161if(*refs->submodule)1162 packed_refs_file =git_pathdup_submodule(refs->submodule,1163"packed-refs");1164else1165 packed_refs_file =git_pathdup("packed-refs");11661167if(refs->packed &&1168!stat_validity_check(&refs->packed->validity, packed_refs_file))1169clear_packed_ref_cache(refs);11701171if(!refs->packed) {1172FILE*f;11731174 refs->packed =xcalloc(1,sizeof(*refs->packed));1175acquire_packed_ref_cache(refs->packed);1176 refs->packed->root =create_dir_entry(refs,"",0,0);1177 f =fopen(packed_refs_file,"r");1178if(f) {1179stat_validity_update(&refs->packed->validity,fileno(f));1180read_packed_refs(f,get_ref_dir(refs->packed->root));1181fclose(f);1182}1183}1184free(packed_refs_file);1185return refs->packed;1186}11871188static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1189{1190returnget_ref_dir(packed_ref_cache->root);1191}11921193static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1194{1195returnget_packed_ref_dir(get_packed_ref_cache(refs));1196}11971198/*1199 * Add a reference to the in-memory packed reference cache. This may1200 * only be called while the packed-refs file is locked (see1201 * lock_packed_refs()). To actually write the packed-refs file, call1202 * commit_packed_refs().1203 */1204static voidadd_packed_ref(struct files_ref_store *refs,1205const char*refname,const unsigned char*sha1)1206{1207struct packed_ref_cache *packed_ref_cache =get_packed_ref_cache(refs);12081209if(!packed_ref_cache->lock)1210die("internal error: packed refs not locked");1211add_ref(get_packed_ref_dir(packed_ref_cache),1212create_ref_entry(refname, sha1, REF_ISPACKED,1));1213}12141215/*1216 * Read the loose references from the namespace dirname into dir1217 * (without recursing). dirname must end with '/'. dir must be the1218 * directory entry corresponding to dirname.1219 */1220static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1221{1222struct files_ref_store *refs = dir->ref_store;1223DIR*d;1224struct dirent *de;1225int dirnamelen =strlen(dirname);1226struct strbuf refname;1227struct strbuf path = STRBUF_INIT;1228size_t path_baselen;1229int err =0;12301231if(*refs->submodule)1232 err =strbuf_git_path_submodule(&path, refs->submodule,"%s", dirname);1233else1234strbuf_git_path(&path,"%s", dirname);1235 path_baselen = path.len;12361237if(err) {1238strbuf_release(&path);1239return;1240}12411242 d =opendir(path.buf);1243if(!d) {1244strbuf_release(&path);1245return;1246}12471248strbuf_init(&refname, dirnamelen +257);1249strbuf_add(&refname, dirname, dirnamelen);12501251while((de =readdir(d)) != NULL) {1252unsigned char sha1[20];1253struct stat st;1254int flag;12551256if(de->d_name[0] =='.')1257continue;1258if(ends_with(de->d_name,".lock"))1259continue;1260strbuf_addstr(&refname, de->d_name);1261strbuf_addstr(&path, de->d_name);1262if(stat(path.buf, &st) <0) {1263;/* silently ignore */1264}else if(S_ISDIR(st.st_mode)) {1265strbuf_addch(&refname,'/');1266add_entry_to_dir(dir,1267create_dir_entry(refs, refname.buf,1268 refname.len,1));1269}else{1270int read_ok;12711272if(*refs->submodule) {1273hashclr(sha1);1274 flag =0;1275 read_ok = !resolve_gitlink_ref(refs->submodule,1276 refname.buf, sha1);1277}else{1278 read_ok = !read_ref_full(refname.buf,1279 RESOLVE_REF_READING,1280 sha1, &flag);1281}12821283if(!read_ok) {1284hashclr(sha1);1285 flag |= REF_ISBROKEN;1286}else if(is_null_sha1(sha1)) {1287/*1288 * It is so astronomically unlikely1289 * that NULL_SHA1 is the SHA-1 of an1290 * actual object that we consider its1291 * appearance in a loose reference1292 * file to be repo corruption1293 * (probably due to a software bug).1294 */1295 flag |= REF_ISBROKEN;1296}12971298if(check_refname_format(refname.buf,1299 REFNAME_ALLOW_ONELEVEL)) {1300if(!refname_is_safe(refname.buf))1301die("loose refname is dangerous:%s", refname.buf);1302hashclr(sha1);1303 flag |= REF_BAD_NAME | REF_ISBROKEN;1304}1305add_entry_to_dir(dir,1306create_ref_entry(refname.buf, sha1, flag,0));1307}1308strbuf_setlen(&refname, dirnamelen);1309strbuf_setlen(&path, path_baselen);1310}1311strbuf_release(&refname);1312strbuf_release(&path);1313closedir(d);1314}13151316static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1317{1318if(!refs->loose) {1319/*1320 * Mark the top-level directory complete because we1321 * are about to read the only subdirectory that can1322 * hold references:1323 */1324 refs->loose =create_dir_entry(refs,"",0,0);1325/*1326 * Create an incomplete entry for "refs/":1327 */1328add_entry_to_dir(get_ref_dir(refs->loose),1329create_dir_entry(refs,"refs/",5,1));1330}1331returnget_ref_dir(refs->loose);1332}13331334/*1335 * Return the ref_entry for the given refname from the packed1336 * references. If it does not exist, return NULL.1337 */1338static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1339const char*refname)1340{1341returnfind_ref(get_packed_refs(refs), refname);1342}13431344/*1345 * A loose ref file doesn't exist; check for a packed ref.1346 */1347static intresolve_packed_ref(struct files_ref_store *refs,1348const char*refname,1349unsigned char*sha1,unsigned int*flags)1350{1351struct ref_entry *entry;13521353/*1354 * The loose reference file does not exist; check for a packed1355 * reference.1356 */1357 entry =get_packed_ref(refs, refname);1358if(entry) {1359hashcpy(sha1, entry->u.value.oid.hash);1360*flags |= REF_ISPACKED;1361return0;1362}1363/* refname is not a packed reference. */1364return-1;1365}13661367static intfiles_read_raw_ref(struct ref_store *ref_store,1368const char*refname,unsigned char*sha1,1369struct strbuf *referent,unsigned int*type)1370{1371struct files_ref_store *refs =1372files_downcast(ref_store,1,"read_raw_ref");1373struct strbuf sb_contents = STRBUF_INIT;1374struct strbuf sb_path = STRBUF_INIT;1375const char*path;1376const char*buf;1377struct stat st;1378int fd;1379int ret = -1;1380int save_errno;1381int remaining_retries =3;13821383*type =0;1384strbuf_reset(&sb_path);13851386if(*refs->submodule)1387strbuf_git_path_submodule(&sb_path, refs->submodule,"%s", refname);1388else1389strbuf_git_path(&sb_path,"%s", refname);13901391 path = sb_path.buf;13921393stat_ref:1394/*1395 * We might have to loop back here to avoid a race1396 * condition: first we lstat() the file, then we try1397 * to read it as a link or as a file. But if somebody1398 * changes the type of the file (file <-> directory1399 * <-> symlink) between the lstat() and reading, then1400 * we don't want to report that as an error but rather1401 * try again starting with the lstat().1402 *1403 * We'll keep a count of the retries, though, just to avoid1404 * any confusing situation sending us into an infinite loop.1405 */14061407if(remaining_retries-- <=0)1408goto out;14091410if(lstat(path, &st) <0) {1411if(errno != ENOENT)1412goto out;1413if(resolve_packed_ref(refs, refname, sha1, type)) {1414 errno = ENOENT;1415goto out;1416}1417 ret =0;1418goto out;1419}14201421/* Follow "normalized" - ie "refs/.." symlinks by hand */1422if(S_ISLNK(st.st_mode)) {1423strbuf_reset(&sb_contents);1424if(strbuf_readlink(&sb_contents, path,0) <0) {1425if(errno == ENOENT || errno == EINVAL)1426/* inconsistent with lstat; retry */1427goto stat_ref;1428else1429goto out;1430}1431if(starts_with(sb_contents.buf,"refs/") &&1432!check_refname_format(sb_contents.buf,0)) {1433strbuf_swap(&sb_contents, referent);1434*type |= REF_ISSYMREF;1435 ret =0;1436goto out;1437}1438/*1439 * It doesn't look like a refname; fall through to just1440 * treating it like a non-symlink, and reading whatever it1441 * points to.1442 */1443}14441445/* Is it a directory? */1446if(S_ISDIR(st.st_mode)) {1447/*1448 * Even though there is a directory where the loose1449 * ref is supposed to be, there could still be a1450 * packed ref:1451 */1452if(resolve_packed_ref(refs, refname, sha1, type)) {1453 errno = EISDIR;1454goto out;1455}1456 ret =0;1457goto out;1458}14591460/*1461 * Anything else, just open it and try to use it as1462 * a ref1463 */1464 fd =open(path, O_RDONLY);1465if(fd <0) {1466if(errno == ENOENT && !S_ISLNK(st.st_mode))1467/* inconsistent with lstat; retry */1468goto stat_ref;1469else1470goto out;1471}1472strbuf_reset(&sb_contents);1473if(strbuf_read(&sb_contents, fd,256) <0) {1474int save_errno = errno;1475close(fd);1476 errno = save_errno;1477goto out;1478}1479close(fd);1480strbuf_rtrim(&sb_contents);1481 buf = sb_contents.buf;1482if(starts_with(buf,"ref:")) {1483 buf +=4;1484while(isspace(*buf))1485 buf++;14861487strbuf_reset(referent);1488strbuf_addstr(referent, buf);1489*type |= REF_ISSYMREF;1490 ret =0;1491goto out;1492}14931494/*1495 * Please note that FETCH_HEAD has additional1496 * data after the sha.1497 */1498if(get_sha1_hex(buf, sha1) ||1499(buf[40] !='\0'&& !isspace(buf[40]))) {1500*type |= REF_ISBROKEN;1501 errno = EINVAL;1502goto out;1503}15041505 ret =0;15061507out:1508 save_errno = errno;1509strbuf_release(&sb_path);1510strbuf_release(&sb_contents);1511 errno = save_errno;1512return ret;1513}15141515static voidunlock_ref(struct ref_lock *lock)1516{1517/* Do not free lock->lk -- atexit() still looks at them */1518if(lock->lk)1519rollback_lock_file(lock->lk);1520free(lock->ref_name);1521free(lock);1522}15231524/*1525 * Lock refname, without following symrefs, and set *lock_p to point1526 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1527 * and type similarly to read_raw_ref().1528 *1529 * The caller must verify that refname is a "safe" reference name (in1530 * the sense of refname_is_safe()) before calling this function.1531 *1532 * If the reference doesn't already exist, verify that refname doesn't1533 * have a D/F conflict with any existing references. extras and skip1534 * are passed to verify_refname_available_dir() for this check.1535 *1536 * If mustexist is not set and the reference is not found or is1537 * broken, lock the reference anyway but clear sha1.1538 *1539 * Return 0 on success. On failure, write an error message to err and1540 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1541 *1542 * Implementation note: This function is basically1543 *1544 * lock reference1545 * read_raw_ref()1546 *1547 * but it includes a lot more code to1548 * - Deal with possible races with other processes1549 * - Avoid calling verify_refname_available_dir() when it can be1550 * avoided, namely if we were successfully able to read the ref1551 * - Generate informative error messages in the case of failure1552 */1553static intlock_raw_ref(struct files_ref_store *refs,1554const char*refname,int mustexist,1555const struct string_list *extras,1556const struct string_list *skip,1557struct ref_lock **lock_p,1558struct strbuf *referent,1559unsigned int*type,1560struct strbuf *err)1561{1562struct ref_lock *lock;1563struct strbuf ref_file = STRBUF_INIT;1564int attempts_remaining =3;1565int ret = TRANSACTION_GENERIC_ERROR;15661567assert(err);1568files_assert_main_repository(refs,"lock_raw_ref");15691570*type =0;15711572/* First lock the file so it can't change out from under us. */15731574*lock_p = lock =xcalloc(1,sizeof(*lock));15751576 lock->ref_name =xstrdup(refname);1577strbuf_git_path(&ref_file,"%s", refname);15781579retry:1580switch(safe_create_leading_directories(ref_file.buf)) {1581case SCLD_OK:1582break;/* success */1583case SCLD_EXISTS:1584/*1585 * Suppose refname is "refs/foo/bar". We just failed1586 * to create the containing directory, "refs/foo",1587 * because there was a non-directory in the way. This1588 * indicates a D/F conflict, probably because of1589 * another reference such as "refs/foo". There is no1590 * reason to expect this error to be transitory.1591 */1592if(verify_refname_available(refname, extras, skip, err)) {1593if(mustexist) {1594/*1595 * To the user the relevant error is1596 * that the "mustexist" reference is1597 * missing:1598 */1599strbuf_reset(err);1600strbuf_addf(err,"unable to resolve reference '%s'",1601 refname);1602}else{1603/*1604 * The error message set by1605 * verify_refname_available_dir() is OK.1606 */1607 ret = TRANSACTION_NAME_CONFLICT;1608}1609}else{1610/*1611 * The file that is in the way isn't a loose1612 * reference. Report it as a low-level1613 * failure.1614 */1615strbuf_addf(err,"unable to create lock file%s.lock; "1616"non-directory in the way",1617 ref_file.buf);1618}1619goto error_return;1620case SCLD_VANISHED:1621/* Maybe another process was tidying up. Try again. */1622if(--attempts_remaining >0)1623goto retry;1624/* fall through */1625default:1626strbuf_addf(err,"unable to create directory for%s",1627 ref_file.buf);1628goto error_return;1629}16301631if(!lock->lk)1632 lock->lk =xcalloc(1,sizeof(struct lock_file));16331634if(hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) <0) {1635if(errno == ENOENT && --attempts_remaining >0) {1636/*1637 * Maybe somebody just deleted one of the1638 * directories leading to ref_file. Try1639 * again:1640 */1641goto retry;1642}else{1643unable_to_lock_message(ref_file.buf, errno, err);1644goto error_return;1645}1646}16471648/*1649 * Now we hold the lock and can read the reference without1650 * fear that its value will change.1651 */16521653if(files_read_raw_ref(&refs->base, refname,1654 lock->old_oid.hash, referent, type)) {1655if(errno == ENOENT) {1656if(mustexist) {1657/* Garden variety missing reference. */1658strbuf_addf(err,"unable to resolve reference '%s'",1659 refname);1660goto error_return;1661}else{1662/*1663 * Reference is missing, but that's OK. We1664 * know that there is not a conflict with1665 * another loose reference because1666 * (supposing that we are trying to lock1667 * reference "refs/foo/bar"):1668 *1669 * - We were successfully able to create1670 * the lockfile refs/foo/bar.lock, so we1671 * know there cannot be a loose reference1672 * named "refs/foo".1673 *1674 * - We got ENOENT and not EISDIR, so we1675 * know that there cannot be a loose1676 * reference named "refs/foo/bar/baz".1677 */1678}1679}else if(errno == EISDIR) {1680/*1681 * There is a directory in the way. It might have1682 * contained references that have been deleted. If1683 * we don't require that the reference already1684 * exists, try to remove the directory so that it1685 * doesn't cause trouble when we want to rename the1686 * lockfile into place later.1687 */1688if(mustexist) {1689/* Garden variety missing reference. */1690strbuf_addf(err,"unable to resolve reference '%s'",1691 refname);1692goto error_return;1693}else if(remove_dir_recursively(&ref_file,1694 REMOVE_DIR_EMPTY_ONLY)) {1695if(verify_refname_available_dir(1696 refname, extras, skip,1697get_loose_refs(refs),1698 err)) {1699/*1700 * The error message set by1701 * verify_refname_available() is OK.1702 */1703 ret = TRANSACTION_NAME_CONFLICT;1704goto error_return;1705}else{1706/*1707 * We can't delete the directory,1708 * but we also don't know of any1709 * references that it should1710 * contain.1711 */1712strbuf_addf(err,"there is a non-empty directory '%s' "1713"blocking reference '%s'",1714 ref_file.buf, refname);1715goto error_return;1716}1717}1718}else if(errno == EINVAL && (*type & REF_ISBROKEN)) {1719strbuf_addf(err,"unable to resolve reference '%s': "1720"reference broken", refname);1721goto error_return;1722}else{1723strbuf_addf(err,"unable to resolve reference '%s':%s",1724 refname,strerror(errno));1725goto error_return;1726}17271728/*1729 * If the ref did not exist and we are creating it,1730 * make sure there is no existing packed ref whose1731 * name begins with our refname, nor a packed ref1732 * whose name is a proper prefix of our refname.1733 */1734if(verify_refname_available_dir(1735 refname, extras, skip,1736get_packed_refs(refs),1737 err)) {1738goto error_return;1739}1740}17411742 ret =0;1743goto out;17441745error_return:1746unlock_ref(lock);1747*lock_p = NULL;17481749out:1750strbuf_release(&ref_file);1751return ret;1752}17531754/*1755 * Peel the entry (if possible) and return its new peel_status. If1756 * repeel is true, re-peel the entry even if there is an old peeled1757 * value that is already stored in it.1758 *1759 * It is OK to call this function with a packed reference entry that1760 * might be stale and might even refer to an object that has since1761 * been garbage-collected. In such a case, if the entry has1762 * REF_KNOWS_PEELED then leave the status unchanged and return1763 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1764 */1765static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1766{1767enum peel_status status;17681769if(entry->flag & REF_KNOWS_PEELED) {1770if(repeel) {1771 entry->flag &= ~REF_KNOWS_PEELED;1772oidclr(&entry->u.value.peeled);1773}else{1774returnis_null_oid(&entry->u.value.peeled) ?1775 PEEL_NON_TAG : PEEL_PEELED;1776}1777}1778if(entry->flag & REF_ISBROKEN)1779return PEEL_BROKEN;1780if(entry->flag & REF_ISSYMREF)1781return PEEL_IS_SYMREF;17821783 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1784if(status == PEEL_PEELED || status == PEEL_NON_TAG)1785 entry->flag |= REF_KNOWS_PEELED;1786return status;1787}17881789static intfiles_peel_ref(struct ref_store *ref_store,1790const char*refname,unsigned char*sha1)1791{1792struct files_ref_store *refs =files_downcast(ref_store,0,"peel_ref");1793int flag;1794unsigned char base[20];17951796if(current_ref_iter && current_ref_iter->refname == refname) {1797struct object_id peeled;17981799if(ref_iterator_peel(current_ref_iter, &peeled))1800return-1;1801hashcpy(sha1, peeled.hash);1802return0;1803}18041805if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1806return-1;18071808/*1809 * If the reference is packed, read its ref_entry from the1810 * cache in the hope that we already know its peeled value.1811 * We only try this optimization on packed references because1812 * (a) forcing the filling of the loose reference cache could1813 * be expensive and (b) loose references anyway usually do not1814 * have REF_KNOWS_PEELED.1815 */1816if(flag & REF_ISPACKED) {1817struct ref_entry *r =get_packed_ref(refs, refname);1818if(r) {1819if(peel_entry(r,0))1820return-1;1821hashcpy(sha1, r->u.value.peeled.hash);1822return0;1823}1824}18251826returnpeel_object(base, sha1);1827}18281829struct files_ref_iterator {1830struct ref_iterator base;18311832struct packed_ref_cache *packed_ref_cache;1833struct ref_iterator *iter0;1834unsigned int flags;1835};18361837static intfiles_ref_iterator_advance(struct ref_iterator *ref_iterator)1838{1839struct files_ref_iterator *iter =1840(struct files_ref_iterator *)ref_iterator;1841int ok;18421843while((ok =ref_iterator_advance(iter->iter0)) == ITER_OK) {1844if(iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&1845ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1846continue;18471848if(!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1849!ref_resolves_to_object(iter->iter0->refname,1850 iter->iter0->oid,1851 iter->iter0->flags))1852continue;18531854 iter->base.refname = iter->iter0->refname;1855 iter->base.oid = iter->iter0->oid;1856 iter->base.flags = iter->iter0->flags;1857return ITER_OK;1858}18591860 iter->iter0 = NULL;1861if(ref_iterator_abort(ref_iterator) != ITER_DONE)1862 ok = ITER_ERROR;18631864return ok;1865}18661867static intfiles_ref_iterator_peel(struct ref_iterator *ref_iterator,1868struct object_id *peeled)1869{1870struct files_ref_iterator *iter =1871(struct files_ref_iterator *)ref_iterator;18721873returnref_iterator_peel(iter->iter0, peeled);1874}18751876static intfiles_ref_iterator_abort(struct ref_iterator *ref_iterator)1877{1878struct files_ref_iterator *iter =1879(struct files_ref_iterator *)ref_iterator;1880int ok = ITER_DONE;18811882if(iter->iter0)1883 ok =ref_iterator_abort(iter->iter0);18841885release_packed_ref_cache(iter->packed_ref_cache);1886base_ref_iterator_free(ref_iterator);1887return ok;1888}18891890static struct ref_iterator_vtable files_ref_iterator_vtable = {1891 files_ref_iterator_advance,1892 files_ref_iterator_peel,1893 files_ref_iterator_abort1894};18951896static struct ref_iterator *files_ref_iterator_begin(1897struct ref_store *ref_store,1898const char*prefix,unsigned int flags)1899{1900struct files_ref_store *refs =1901files_downcast(ref_store,1,"ref_iterator_begin");1902struct ref_dir *loose_dir, *packed_dir;1903struct ref_iterator *loose_iter, *packed_iter;1904struct files_ref_iterator *iter;1905struct ref_iterator *ref_iterator;19061907if(!refs)1908returnempty_ref_iterator_begin();19091910if(ref_paranoia <0)1911 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1912if(ref_paranoia)1913 flags |= DO_FOR_EACH_INCLUDE_BROKEN;19141915 iter =xcalloc(1,sizeof(*iter));1916 ref_iterator = &iter->base;1917base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);19181919/*1920 * We must make sure that all loose refs are read before1921 * accessing the packed-refs file; this avoids a race1922 * condition if loose refs are migrated to the packed-refs1923 * file by a simultaneous process, but our in-memory view is1924 * from before the migration. We ensure this as follows:1925 * First, we call prime_ref_dir(), which pre-reads the loose1926 * references for the subtree into the cache. (If they've1927 * already been read, that's OK; we only need to guarantee1928 * that they're read before the packed refs, not *how much*1929 * before.) After that, we call get_packed_ref_cache(), which1930 * internally checks whether the packed-ref cache is up to1931 * date with what is on disk, and re-reads it if not.1932 */19331934 loose_dir =get_loose_refs(refs);19351936if(prefix && *prefix)1937 loose_dir =find_containing_dir(loose_dir, prefix,0);19381939if(loose_dir) {1940prime_ref_dir(loose_dir);1941 loose_iter =cache_ref_iterator_begin(loose_dir);1942}else{1943/* There's nothing to iterate over. */1944 loose_iter =empty_ref_iterator_begin();1945}19461947 iter->packed_ref_cache =get_packed_ref_cache(refs);1948acquire_packed_ref_cache(iter->packed_ref_cache);1949 packed_dir =get_packed_ref_dir(iter->packed_ref_cache);19501951if(prefix && *prefix)1952 packed_dir =find_containing_dir(packed_dir, prefix,0);19531954if(packed_dir) {1955 packed_iter =cache_ref_iterator_begin(packed_dir);1956}else{1957/* There's nothing to iterate over. */1958 packed_iter =empty_ref_iterator_begin();1959}19601961 iter->iter0 =overlay_ref_iterator_begin(loose_iter, packed_iter);1962 iter->flags = flags;19631964return ref_iterator;1965}19661967/*1968 * Verify that the reference locked by lock has the value old_sha1.1969 * Fail if the reference doesn't exist and mustexist is set. Return 01970 * on success. On error, write an error message to err, set errno, and1971 * return a negative value.1972 */1973static intverify_lock(struct ref_lock *lock,1974const unsigned char*old_sha1,int mustexist,1975struct strbuf *err)1976{1977assert(err);19781979if(read_ref_full(lock->ref_name,1980 mustexist ? RESOLVE_REF_READING :0,1981 lock->old_oid.hash, NULL)) {1982if(old_sha1) {1983int save_errno = errno;1984strbuf_addf(err,"can't verify ref '%s'", lock->ref_name);1985 errno = save_errno;1986return-1;1987}else{1988oidclr(&lock->old_oid);1989return0;1990}1991}1992if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {1993strbuf_addf(err,"ref '%s' is at%sbut expected%s",1994 lock->ref_name,1995oid_to_hex(&lock->old_oid),1996sha1_to_hex(old_sha1));1997 errno = EBUSY;1998return-1;1999}2000return0;2001}20022003static intremove_empty_directories(struct strbuf *path)2004{2005/*2006 * we want to create a file but there is a directory there;2007 * if that is an empty directory (or a directory that contains2008 * only empty directories), remove them.2009 */2010returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);2011}20122013/*2014 * Locks a ref returning the lock on success and NULL on failure.2015 * On failure errno is set to something meaningful.2016 */2017static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,2018const char*refname,2019const unsigned char*old_sha1,2020const struct string_list *extras,2021const struct string_list *skip,2022unsigned int flags,int*type,2023struct strbuf *err)2024{2025struct strbuf ref_file = STRBUF_INIT;2026struct ref_lock *lock;2027int last_errno =0;2028int lflags = LOCK_NO_DEREF;2029int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2030int resolve_flags = RESOLVE_REF_NO_RECURSE;2031int attempts_remaining =3;2032int resolved;20332034files_assert_main_repository(refs,"lock_ref_sha1_basic");2035assert(err);20362037 lock =xcalloc(1,sizeof(struct ref_lock));20382039if(mustexist)2040 resolve_flags |= RESOLVE_REF_READING;2041if(flags & REF_DELETING)2042 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20432044strbuf_git_path(&ref_file,"%s", refname);2045 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2046 lock->old_oid.hash, type);2047if(!resolved && errno == EISDIR) {2048/*2049 * we are trying to lock foo but we used to2050 * have foo/bar which now does not exist;2051 * it is normal for the empty directory 'foo'2052 * to remain.2053 */2054if(remove_empty_directories(&ref_file)) {2055 last_errno = errno;2056if(!verify_refname_available_dir(2057 refname, extras, skip,2058get_loose_refs(refs), err))2059strbuf_addf(err,"there are still refs under '%s'",2060 refname);2061goto error_return;2062}2063 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2064 lock->old_oid.hash, type);2065}2066if(!resolved) {2067 last_errno = errno;2068if(last_errno != ENOTDIR ||2069!verify_refname_available_dir(2070 refname, extras, skip,2071get_loose_refs(refs), err))2072strbuf_addf(err,"unable to resolve reference '%s':%s",2073 refname,strerror(last_errno));20742075goto error_return;2076}20772078/*2079 * If the ref did not exist and we are creating it, make sure2080 * there is no existing packed ref whose name begins with our2081 * refname, nor a packed ref whose name is a proper prefix of2082 * our refname.2083 */2084if(is_null_oid(&lock->old_oid) &&2085verify_refname_available_dir(refname, extras, skip,2086get_packed_refs(refs),2087 err)) {2088 last_errno = ENOTDIR;2089goto error_return;2090}20912092 lock->lk =xcalloc(1,sizeof(struct lock_file));20932094 lock->ref_name =xstrdup(refname);20952096 retry:2097switch(safe_create_leading_directories_const(ref_file.buf)) {2098case SCLD_OK:2099break;/* success */2100case SCLD_VANISHED:2101if(--attempts_remaining >0)2102goto retry;2103/* fall through */2104default:2105 last_errno = errno;2106strbuf_addf(err,"unable to create directory for '%s'",2107 ref_file.buf);2108goto error_return;2109}21102111if(hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) <0) {2112 last_errno = errno;2113if(errno == ENOENT && --attempts_remaining >0)2114/*2115 * Maybe somebody just deleted one of the2116 * directories leading to ref_file. Try2117 * again:2118 */2119goto retry;2120else{2121unable_to_lock_message(ref_file.buf, errno, err);2122goto error_return;2123}2124}2125if(verify_lock(lock, old_sha1, mustexist, err)) {2126 last_errno = errno;2127goto error_return;2128}2129goto out;21302131 error_return:2132unlock_ref(lock);2133 lock = NULL;21342135 out:2136strbuf_release(&ref_file);2137 errno = last_errno;2138return lock;2139}21402141/*2142 * Write an entry to the packed-refs file for the specified refname.2143 * If peeled is non-NULL, write it as the entry's peeled value.2144 */2145static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2146unsigned char*peeled)2147{2148fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2149if(peeled)2150fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2151}21522153/*2154 * An each_ref_entry_fn that writes the entry to a packed-refs file.2155 */2156static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2157{2158enum peel_status peel_status =peel_entry(entry,0);21592160if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2161error("internal error:%sis not a valid packed reference!",2162 entry->name);2163write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2164 peel_status == PEEL_PEELED ?2165 entry->u.value.peeled.hash : NULL);2166return0;2167}21682169/*2170 * Lock the packed-refs file for writing. Flags is passed to2171 * hold_lock_file_for_update(). Return 0 on success. On errors, set2172 * errno appropriately and return a nonzero value.2173 */2174static intlock_packed_refs(struct files_ref_store *refs,int flags)2175{2176static int timeout_configured =0;2177static int timeout_value =1000;2178struct packed_ref_cache *packed_ref_cache;21792180files_assert_main_repository(refs,"lock_packed_refs");21812182if(!timeout_configured) {2183git_config_get_int("core.packedrefstimeout", &timeout_value);2184 timeout_configured =1;2185}21862187if(hold_lock_file_for_update_timeout(2188&packlock,git_path("packed-refs"),2189 flags, timeout_value) <0)2190return-1;2191/*2192 * Get the current packed-refs while holding the lock. If the2193 * packed-refs file has been modified since we last read it,2194 * this will automatically invalidate the cache and re-read2195 * the packed-refs file.2196 */2197 packed_ref_cache =get_packed_ref_cache(refs);2198 packed_ref_cache->lock = &packlock;2199/* Increment the reference count to prevent it from being freed: */2200acquire_packed_ref_cache(packed_ref_cache);2201return0;2202}22032204/*2205 * Write the current version of the packed refs cache from memory to2206 * disk. The packed-refs file must already be locked for writing (see2207 * lock_packed_refs()). Return zero on success. On errors, set errno2208 * and return a nonzero value2209 */2210static intcommit_packed_refs(struct files_ref_store *refs)2211{2212struct packed_ref_cache *packed_ref_cache =2213get_packed_ref_cache(refs);2214int error =0;2215int save_errno =0;2216FILE*out;22172218files_assert_main_repository(refs,"commit_packed_refs");22192220if(!packed_ref_cache->lock)2221die("internal error: packed-refs not locked");22222223 out =fdopen_lock_file(packed_ref_cache->lock,"w");2224if(!out)2225die_errno("unable to fdopen packed-refs descriptor");22262227fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2228do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),22290, write_packed_entry_fn, out);22302231if(commit_lock_file(packed_ref_cache->lock)) {2232 save_errno = errno;2233 error = -1;2234}2235 packed_ref_cache->lock = NULL;2236release_packed_ref_cache(packed_ref_cache);2237 errno = save_errno;2238return error;2239}22402241/*2242 * Rollback the lockfile for the packed-refs file, and discard the2243 * in-memory packed reference cache. (The packed-refs file will be2244 * read anew if it is needed again after this function is called.)2245 */2246static voidrollback_packed_refs(struct files_ref_store *refs)2247{2248struct packed_ref_cache *packed_ref_cache =2249get_packed_ref_cache(refs);22502251files_assert_main_repository(refs,"rollback_packed_refs");22522253if(!packed_ref_cache->lock)2254die("internal error: packed-refs not locked");2255rollback_lock_file(packed_ref_cache->lock);2256 packed_ref_cache->lock = NULL;2257release_packed_ref_cache(packed_ref_cache);2258clear_packed_ref_cache(refs);2259}22602261struct ref_to_prune {2262struct ref_to_prune *next;2263unsigned char sha1[20];2264char name[FLEX_ARRAY];2265};22662267struct pack_refs_cb_data {2268unsigned int flags;2269struct ref_dir *packed_refs;2270struct ref_to_prune *ref_to_prune;2271};22722273/*2274 * An each_ref_entry_fn that is run over loose references only. If2275 * the loose reference can be packed, add an entry in the packed ref2276 * cache. If the reference should be pruned, also add it to2277 * ref_to_prune in the pack_refs_cb_data.2278 */2279static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2280{2281struct pack_refs_cb_data *cb = cb_data;2282enum peel_status peel_status;2283struct ref_entry *packed_entry;2284int is_tag_ref =starts_with(entry->name,"refs/tags/");22852286/* Do not pack per-worktree refs: */2287if(ref_type(entry->name) != REF_TYPE_NORMAL)2288return0;22892290/* ALWAYS pack tags */2291if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2292return0;22932294/* Do not pack symbolic or broken refs: */2295if((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2296return0;22972298/* Add a packed ref cache entry equivalent to the loose entry. */2299 peel_status =peel_entry(entry,1);2300if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2301die("internal error peeling reference%s(%s)",2302 entry->name,oid_to_hex(&entry->u.value.oid));2303 packed_entry =find_ref(cb->packed_refs, entry->name);2304if(packed_entry) {2305/* Overwrite existing packed entry with info from loose entry */2306 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2307oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2308}else{2309 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2310 REF_ISPACKED | REF_KNOWS_PEELED,0);2311add_ref(cb->packed_refs, packed_entry);2312}2313oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);23142315/* Schedule the loose reference for pruning if requested. */2316if((cb->flags & PACK_REFS_PRUNE)) {2317struct ref_to_prune *n;2318FLEX_ALLOC_STR(n, name, entry->name);2319hashcpy(n->sha1, entry->u.value.oid.hash);2320 n->next = cb->ref_to_prune;2321 cb->ref_to_prune = n;2322}2323return0;2324}23252326/*2327 * Remove empty parents, but spare refs/ and immediate subdirs.2328 * Note: munges *name.2329 */2330static voidtry_remove_empty_parents(char*name)2331{2332char*p, *q;2333int i;2334 p = name;2335for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2336while(*p && *p !='/')2337 p++;2338/* tolerate duplicate slashes; see check_refname_format() */2339while(*p =='/')2340 p++;2341}2342for(q = p; *q; q++)2343;2344while(1) {2345while(q > p && *q !='/')2346 q--;2347while(q > p && *(q-1) =='/')2348 q--;2349if(q == p)2350break;2351*q ='\0';2352if(rmdir(git_path("%s", name)))2353break;2354}2355}23562357/* make sure nobody touched the ref, and unlink */2358static voidprune_ref(struct ref_to_prune *r)2359{2360struct ref_transaction *transaction;2361struct strbuf err = STRBUF_INIT;23622363if(check_refname_format(r->name,0))2364return;23652366 transaction =ref_transaction_begin(&err);2367if(!transaction ||2368ref_transaction_delete(transaction, r->name, r->sha1,2369 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2370ref_transaction_commit(transaction, &err)) {2371ref_transaction_free(transaction);2372error("%s", err.buf);2373strbuf_release(&err);2374return;2375}2376ref_transaction_free(transaction);2377strbuf_release(&err);2378try_remove_empty_parents(r->name);2379}23802381static voidprune_refs(struct ref_to_prune *r)2382{2383while(r) {2384prune_ref(r);2385 r = r->next;2386}2387}23882389static intfiles_pack_refs(struct ref_store *ref_store,unsigned int flags)2390{2391struct files_ref_store *refs =2392files_downcast(ref_store,0,"pack_refs");2393struct pack_refs_cb_data cbdata;23942395memset(&cbdata,0,sizeof(cbdata));2396 cbdata.flags = flags;23972398lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2399 cbdata.packed_refs =get_packed_refs(refs);24002401do_for_each_entry_in_dir(get_loose_refs(refs),0,2402 pack_if_possible_fn, &cbdata);24032404if(commit_packed_refs(refs))2405die_errno("unable to overwrite old ref-pack file");24062407prune_refs(cbdata.ref_to_prune);2408return0;2409}24102411/*2412 * Rewrite the packed-refs file, omitting any refs listed in2413 * 'refnames'. On error, leave packed-refs unchanged, write an error2414 * message to 'err', and return a nonzero value.2415 *2416 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2417 */2418static intrepack_without_refs(struct files_ref_store *refs,2419struct string_list *refnames,struct strbuf *err)2420{2421struct ref_dir *packed;2422struct string_list_item *refname;2423int ret, needs_repacking =0, removed =0;24242425files_assert_main_repository(refs,"repack_without_refs");2426assert(err);24272428/* Look for a packed ref */2429for_each_string_list_item(refname, refnames) {2430if(get_packed_ref(refs, refname->string)) {2431 needs_repacking =1;2432break;2433}2434}24352436/* Avoid locking if we have nothing to do */2437if(!needs_repacking)2438return0;/* no refname exists in packed refs */24392440if(lock_packed_refs(refs,0)) {2441unable_to_lock_message(git_path("packed-refs"), errno, err);2442return-1;2443}2444 packed =get_packed_refs(refs);24452446/* Remove refnames from the cache */2447for_each_string_list_item(refname, refnames)2448if(remove_entry(packed, refname->string) != -1)2449 removed =1;2450if(!removed) {2451/*2452 * All packed entries disappeared while we were2453 * acquiring the lock.2454 */2455rollback_packed_refs(refs);2456return0;2457}24582459/* Write what remains */2460 ret =commit_packed_refs(refs);2461if(ret)2462strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2463strerror(errno));2464return ret;2465}24662467static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2468{2469assert(err);24702471if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2472/*2473 * loose. The loose file name is the same as the2474 * lockfile name, minus ".lock":2475 */2476char*loose_filename =get_locked_file_path(lock->lk);2477int res =unlink_or_msg(loose_filename, err);2478free(loose_filename);2479if(res)2480return1;2481}2482return0;2483}24842485static intfiles_delete_refs(struct ref_store *ref_store,2486struct string_list *refnames,unsigned int flags)2487{2488struct files_ref_store *refs =2489files_downcast(ref_store,0,"delete_refs");2490struct strbuf err = STRBUF_INIT;2491int i, result =0;24922493if(!refnames->nr)2494return0;24952496 result =repack_without_refs(refs, refnames, &err);2497if(result) {2498/*2499 * If we failed to rewrite the packed-refs file, then2500 * it is unsafe to try to remove loose refs, because2501 * doing so might expose an obsolete packed value for2502 * a reference that might even point at an object that2503 * has been garbage collected.2504 */2505if(refnames->nr ==1)2506error(_("could not delete reference%s:%s"),2507 refnames->items[0].string, err.buf);2508else2509error(_("could not delete references:%s"), err.buf);25102511goto out;2512}25132514for(i =0; i < refnames->nr; i++) {2515const char*refname = refnames->items[i].string;25162517if(delete_ref(refname, NULL, flags))2518 result |=error(_("could not remove reference%s"), refname);2519}25202521out:2522strbuf_release(&err);2523return result;2524}25252526/*2527 * People using contrib's git-new-workdir have .git/logs/refs ->2528 * /some/other/path/.git/logs/refs, and that may live on another device.2529 *2530 * IOW, to avoid cross device rename errors, the temporary renamed log must2531 * live into logs/refs.2532 */2533#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"25342535static intrename_tmp_log(const char*newrefname)2536{2537int attempts_remaining =4;2538struct strbuf path = STRBUF_INIT;2539int ret = -1;25402541 retry:2542strbuf_reset(&path);2543strbuf_git_path(&path,"logs/%s", newrefname);2544switch(safe_create_leading_directories_const(path.buf)) {2545case SCLD_OK:2546break;/* success */2547case SCLD_VANISHED:2548if(--attempts_remaining >0)2549goto retry;2550/* fall through */2551default:2552error("unable to create directory for%s", newrefname);2553goto out;2554}25552556if(rename(git_path(TMP_RENAMED_LOG), path.buf)) {2557if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2558/*2559 * rename(a, b) when b is an existing2560 * directory ought to result in ISDIR, but2561 * Solaris 5.8 gives ENOTDIR. Sheesh.2562 */2563if(remove_empty_directories(&path)) {2564error("Directory not empty: logs/%s", newrefname);2565goto out;2566}2567goto retry;2568}else if(errno == ENOENT && --attempts_remaining >0) {2569/*2570 * Maybe another process just deleted one of2571 * the directories in the path to newrefname.2572 * Try again from the beginning.2573 */2574goto retry;2575}else{2576error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2577 newrefname,strerror(errno));2578goto out;2579}2580}2581 ret =0;2582out:2583strbuf_release(&path);2584return ret;2585}25862587static intfiles_verify_refname_available(struct ref_store *ref_store,2588const char*newname,2589const struct string_list *extras,2590const struct string_list *skip,2591struct strbuf *err)2592{2593struct files_ref_store *refs =2594files_downcast(ref_store,1,"verify_refname_available");2595struct ref_dir *packed_refs =get_packed_refs(refs);2596struct ref_dir *loose_refs =get_loose_refs(refs);25972598if(verify_refname_available_dir(newname, extras, skip,2599 packed_refs, err) ||2600verify_refname_available_dir(newname, extras, skip,2601 loose_refs, err))2602return-1;26032604return0;2605}26062607static intwrite_ref_to_lockfile(struct ref_lock *lock,2608const unsigned char*sha1,struct strbuf *err);2609static intcommit_ref_update(struct files_ref_store *refs,2610struct ref_lock *lock,2611const unsigned char*sha1,const char*logmsg,2612struct strbuf *err);26132614static intfiles_rename_ref(struct ref_store *ref_store,2615const char*oldrefname,const char*newrefname,2616const char*logmsg)2617{2618struct files_ref_store *refs =2619files_downcast(ref_store,0,"rename_ref");2620unsigned char sha1[20], orig_sha1[20];2621int flag =0, logmoved =0;2622struct ref_lock *lock;2623struct stat loginfo;2624int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2625struct strbuf err = STRBUF_INIT;26262627if(log &&S_ISLNK(loginfo.st_mode))2628returnerror("reflog for%sis a symlink", oldrefname);26292630if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2631 orig_sha1, &flag))2632returnerror("refname%snot found", oldrefname);26332634if(flag & REF_ISSYMREF)2635returnerror("refname%sis a symbolic ref, renaming it is not supported",2636 oldrefname);2637if(!rename_ref_available(oldrefname, newrefname))2638return1;26392640if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2641returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2642 oldrefname,strerror(errno));26432644if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2645error("unable to delete old%s", oldrefname);2646goto rollback;2647}26482649/*2650 * Since we are doing a shallow lookup, sha1 is not the2651 * correct value to pass to delete_ref as old_sha1. But that2652 * doesn't matter, because an old_sha1 check wouldn't add to2653 * the safety anyway; we want to delete the reference whatever2654 * its current value.2655 */2656if(!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2657 sha1, NULL) &&2658delete_ref(newrefname, NULL, REF_NODEREF)) {2659if(errno==EISDIR) {2660struct strbuf path = STRBUF_INIT;2661int result;26622663strbuf_git_path(&path,"%s", newrefname);2664 result =remove_empty_directories(&path);2665strbuf_release(&path);26662667if(result) {2668error("Directory not empty:%s", newrefname);2669goto rollback;2670}2671}else{2672error("unable to delete existing%s", newrefname);2673goto rollback;2674}2675}26762677if(log &&rename_tmp_log(newrefname))2678goto rollback;26792680 logmoved = log;26812682 lock =lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,2683 REF_NODEREF, NULL, &err);2684if(!lock) {2685error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2686strbuf_release(&err);2687goto rollback;2688}2689hashcpy(lock->old_oid.hash, orig_sha1);26902691if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2692commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {2693error("unable to write current sha1 into%s:%s", newrefname, err.buf);2694strbuf_release(&err);2695goto rollback;2696}26972698return0;26992700 rollback:2701 lock =lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,2702 REF_NODEREF, NULL, &err);2703if(!lock) {2704error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2705strbuf_release(&err);2706goto rollbacklog;2707}27082709 flag = log_all_ref_updates;2710 log_all_ref_updates =0;2711if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2712commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {2713error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2714strbuf_release(&err);2715}2716 log_all_ref_updates = flag;27172718 rollbacklog:2719if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2720error("unable to restore logfile%sfrom%s:%s",2721 oldrefname, newrefname,strerror(errno));2722if(!logmoved && log &&2723rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2724error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2725 oldrefname,strerror(errno));27262727return1;2728}27292730static intclose_ref(struct ref_lock *lock)2731{2732if(close_lock_file(lock->lk))2733return-1;2734return0;2735}27362737static intcommit_ref(struct ref_lock *lock)2738{2739char*path =get_locked_file_path(lock->lk);2740struct stat st;27412742if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2743/*2744 * There is a directory at the path we want to rename2745 * the lockfile to. Hopefully it is empty; try to2746 * delete it.2747 */2748size_t len =strlen(path);2749struct strbuf sb_path = STRBUF_INIT;27502751strbuf_attach(&sb_path, path, len, len);27522753/*2754 * If this fails, commit_lock_file() will also fail2755 * and will report the problem.2756 */2757remove_empty_directories(&sb_path);2758strbuf_release(&sb_path);2759}else{2760free(path);2761}27622763if(commit_lock_file(lock->lk))2764return-1;2765return0;2766}27672768/*2769 * Create a reflog for a ref. If force_create = 0, the reflog will2770 * only be created for certain refs (those for which2771 * should_autocreate_reflog returns non-zero. Otherwise, create it2772 * regardless of the ref name. Fill in *err and return -1 on failure.2773 */2774static intlog_ref_setup(const char*refname,struct strbuf *logfile,struct strbuf *err,int force_create)2775{2776int logfd, oflags = O_APPEND | O_WRONLY;27772778strbuf_git_path(logfile,"logs/%s", refname);2779if(force_create ||should_autocreate_reflog(refname)) {2780if(safe_create_leading_directories(logfile->buf) <0) {2781strbuf_addf(err,"unable to create directory for '%s': "2782"%s", logfile->buf,strerror(errno));2783return-1;2784}2785 oflags |= O_CREAT;2786}27872788 logfd =open(logfile->buf, oflags,0666);2789if(logfd <0) {2790if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2791return0;27922793if(errno == EISDIR) {2794if(remove_empty_directories(logfile)) {2795strbuf_addf(err,"there are still logs under "2796"'%s'", logfile->buf);2797return-1;2798}2799 logfd =open(logfile->buf, oflags,0666);2800}28012802if(logfd <0) {2803strbuf_addf(err,"unable to append to '%s':%s",2804 logfile->buf,strerror(errno));2805return-1;2806}2807}28082809adjust_shared_perm(logfile->buf);2810close(logfd);2811return0;2812}281328142815static intfiles_create_reflog(struct ref_store *ref_store,2816const char*refname,int force_create,2817struct strbuf *err)2818{2819int ret;2820struct strbuf sb = STRBUF_INIT;28212822/* Check validity (but we don't need the result): */2823files_downcast(ref_store,0,"create_reflog");28242825 ret =log_ref_setup(refname, &sb, err, force_create);2826strbuf_release(&sb);2827return ret;2828}28292830static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2831const unsigned char*new_sha1,2832const char*committer,const char*msg)2833{2834int msglen, written;2835unsigned maxlen, len;2836char*logrec;28372838 msglen = msg ?strlen(msg) :0;2839 maxlen =strlen(committer) + msglen +100;2840 logrec =xmalloc(maxlen);2841 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2842sha1_to_hex(old_sha1),2843sha1_to_hex(new_sha1),2844 committer);2845if(msglen)2846 len +=copy_reflog_msg(logrec + len -1, msg) -1;28472848 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2849free(logrec);2850if(written != len)2851return-1;28522853return0;2854}28552856static intlog_ref_write_1(const char*refname,const unsigned char*old_sha1,2857const unsigned char*new_sha1,const char*msg,2858struct strbuf *logfile,int flags,2859struct strbuf *err)2860{2861int logfd, result, oflags = O_APPEND | O_WRONLY;28622863if(log_all_ref_updates <0)2864 log_all_ref_updates = !is_bare_repository();28652866 result =log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);28672868if(result)2869return result;28702871 logfd =open(logfile->buf, oflags);2872if(logfd <0)2873return0;2874 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2875git_committer_info(0), msg);2876if(result) {2877strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2878strerror(errno));2879close(logfd);2880return-1;2881}2882if(close(logfd)) {2883strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2884strerror(errno));2885return-1;2886}2887return0;2888}28892890static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2891const unsigned char*new_sha1,const char*msg,2892int flags,struct strbuf *err)2893{2894returnfiles_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2895 err);2896}28972898intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1,2899const unsigned char*new_sha1,const char*msg,2900int flags,struct strbuf *err)2901{2902struct strbuf sb = STRBUF_INIT;2903int ret =log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2904 err);2905strbuf_release(&sb);2906return ret;2907}29082909/*2910 * Write sha1 into the open lockfile, then close the lockfile. On2911 * errors, rollback the lockfile, fill in *err and2912 * return -1.2913 */2914static intwrite_ref_to_lockfile(struct ref_lock *lock,2915const unsigned char*sha1,struct strbuf *err)2916{2917static char term ='\n';2918struct object *o;2919int fd;29202921 o =parse_object(sha1);2922if(!o) {2923strbuf_addf(err,2924"trying to write ref '%s' with nonexistent object%s",2925 lock->ref_name,sha1_to_hex(sha1));2926unlock_ref(lock);2927return-1;2928}2929if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2930strbuf_addf(err,2931"trying to write non-commit object%sto branch '%s'",2932sha1_to_hex(sha1), lock->ref_name);2933unlock_ref(lock);2934return-1;2935}2936 fd =get_lock_file_fd(lock->lk);2937if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2938write_in_full(fd, &term,1) !=1||2939close_ref(lock) <0) {2940strbuf_addf(err,2941"couldn't write '%s'",get_lock_file_path(lock->lk));2942unlock_ref(lock);2943return-1;2944}2945return0;2946}29472948/*2949 * Commit a change to a loose reference that has already been written2950 * to the loose reference lockfile. Also update the reflogs if2951 * necessary, using the specified lockmsg (which can be NULL).2952 */2953static intcommit_ref_update(struct files_ref_store *refs,2954struct ref_lock *lock,2955const unsigned char*sha1,const char*logmsg,2956struct strbuf *err)2957{2958files_assert_main_repository(refs,"commit_ref_update");29592960clear_loose_ref_cache(refs);2961if(log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg,0, err)) {2962char*old_msg =strbuf_detach(err, NULL);2963strbuf_addf(err,"cannot update the ref '%s':%s",2964 lock->ref_name, old_msg);2965free(old_msg);2966unlock_ref(lock);2967return-1;2968}29692970if(strcmp(lock->ref_name,"HEAD") !=0) {2971/*2972 * Special hack: If a branch is updated directly and HEAD2973 * points to it (may happen on the remote side of a push2974 * for example) then logically the HEAD reflog should be2975 * updated too.2976 * A generic solution implies reverse symref information,2977 * but finding all symrefs pointing to the given branch2978 * would be rather costly for this rare event (the direct2979 * update of a branch) to be worth it. So let's cheat and2980 * check with HEAD only which should cover 99% of all usage2981 * scenarios (even 100% of the default ones).2982 */2983unsigned char head_sha1[20];2984int head_flag;2985const char*head_ref;29862987 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2988 head_sha1, &head_flag);2989if(head_ref && (head_flag & REF_ISSYMREF) &&2990!strcmp(head_ref, lock->ref_name)) {2991struct strbuf log_err = STRBUF_INIT;2992if(log_ref_write("HEAD", lock->old_oid.hash, sha1,2993 logmsg,0, &log_err)) {2994error("%s", log_err.buf);2995strbuf_release(&log_err);2996}2997}2998}29993000if(commit_ref(lock)) {3001strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3002unlock_ref(lock);3003return-1;3004}30053006unlock_ref(lock);3007return0;3008}30093010static intcreate_ref_symlink(struct ref_lock *lock,const char*target)3011{3012int ret = -1;3013#ifndef NO_SYMLINK_HEAD3014char*ref_path =get_locked_file_path(lock->lk);3015unlink(ref_path);3016 ret =symlink(target, ref_path);3017free(ref_path);30183019if(ret)3020fprintf(stderr,"no symlink - falling back to symbolic ref\n");3021#endif3022return ret;3023}30243025static voidupdate_symref_reflog(struct ref_lock *lock,const char*refname,3026const char*target,const char*logmsg)3027{3028struct strbuf err = STRBUF_INIT;3029unsigned char new_sha1[20];3030if(logmsg && !read_ref(target, new_sha1) &&3031log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg,0, &err)) {3032error("%s", err.buf);3033strbuf_release(&err);3034}3035}30363037static intcreate_symref_locked(struct ref_lock *lock,const char*refname,3038const char*target,const char*logmsg)3039{3040if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {3041update_symref_reflog(lock, refname, target, logmsg);3042return0;3043}30443045if(!fdopen_lock_file(lock->lk,"w"))3046returnerror("unable to fdopen%s:%s",3047 lock->lk->tempfile.filename.buf,strerror(errno));30483049update_symref_reflog(lock, refname, target, logmsg);30503051/* no error check; commit_ref will check ferror */3052fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);3053if(commit_ref(lock) <0)3054returnerror("unable to write symref for%s:%s", refname,3055strerror(errno));3056return0;3057}30583059static intfiles_create_symref(struct ref_store *ref_store,3060const char*refname,const char*target,3061const char*logmsg)3062{3063struct files_ref_store *refs =3064files_downcast(ref_store,0,"create_symref");3065struct strbuf err = STRBUF_INIT;3066struct ref_lock *lock;3067int ret;30683069 lock =lock_ref_sha1_basic(refs, refname, NULL,3070 NULL, NULL, REF_NODEREF, NULL,3071&err);3072if(!lock) {3073error("%s", err.buf);3074strbuf_release(&err);3075return-1;3076}30773078 ret =create_symref_locked(lock, refname, target, logmsg);3079unlock_ref(lock);3080return ret;3081}30823083intset_worktree_head_symref(const char*gitdir,const char*target)3084{3085static struct lock_file head_lock;3086struct ref_lock *lock;3087struct strbuf head_path = STRBUF_INIT;3088const char*head_rel;3089int ret;30903091strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));3092if(hold_lock_file_for_update(&head_lock, head_path.buf,3093 LOCK_NO_DEREF) <0) {3094struct strbuf err = STRBUF_INIT;3095unable_to_lock_message(head_path.buf, errno, &err);3096error("%s", err.buf);3097strbuf_release(&err);3098strbuf_release(&head_path);3099return-1;3100}31013102/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3103 linked trees */3104 head_rel =remove_leading_path(head_path.buf,3105absolute_path(get_git_common_dir()));3106/* to make use of create_symref_locked(), initialize ref_lock */3107 lock =xcalloc(1,sizeof(struct ref_lock));3108 lock->lk = &head_lock;3109 lock->ref_name =xstrdup(head_rel);31103111 ret =create_symref_locked(lock, head_rel, target, NULL);31123113unlock_ref(lock);/* will free lock */3114strbuf_release(&head_path);3115return ret;3116}31173118static intfiles_reflog_exists(struct ref_store *ref_store,3119const char*refname)3120{3121struct stat st;31223123/* Check validity (but we don't need the result): */3124files_downcast(ref_store,0,"reflog_exists");31253126return!lstat(git_path("logs/%s", refname), &st) &&3127S_ISREG(st.st_mode);3128}31293130static intfiles_delete_reflog(struct ref_store *ref_store,3131const char*refname)3132{3133/* Check validity (but we don't need the result): */3134files_downcast(ref_store,0,"delete_reflog");31353136returnremove_path(git_path("logs/%s", refname));3137}31383139static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3140{3141unsigned char osha1[20], nsha1[20];3142char*email_end, *message;3143unsigned long timestamp;3144int tz;31453146/* old SP new SP name <email> SP time TAB msg LF */3147if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3148get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3149get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3150!(email_end =strchr(sb->buf +82,'>')) ||3151 email_end[1] !=' '||3152!(timestamp =strtoul(email_end +2, &message,10)) ||3153!message || message[0] !=' '||3154(message[1] !='+'&& message[1] !='-') ||3155!isdigit(message[2]) || !isdigit(message[3]) ||3156!isdigit(message[4]) || !isdigit(message[5]))3157return0;/* corrupt? */3158 email_end[1] ='\0';3159 tz =strtol(message +1, NULL,10);3160if(message[6] !='\t')3161 message +=6;3162else3163 message +=7;3164returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3165}31663167static char*find_beginning_of_line(char*bob,char*scan)3168{3169while(bob < scan && *(--scan) !='\n')3170;/* keep scanning backwards */3171/*3172 * Return either beginning of the buffer, or LF at the end of3173 * the previous line.3174 */3175return scan;3176}31773178static intfiles_for_each_reflog_ent_reverse(struct ref_store *ref_store,3179const char*refname,3180 each_reflog_ent_fn fn,3181void*cb_data)3182{3183struct strbuf sb = STRBUF_INIT;3184FILE*logfp;3185long pos;3186int ret =0, at_tail =1;31873188/* Check validity (but we don't need the result): */3189files_downcast(ref_store,0,"for_each_reflog_ent_reverse");31903191 logfp =fopen(git_path("logs/%s", refname),"r");3192if(!logfp)3193return-1;31943195/* Jump to the end */3196if(fseek(logfp,0, SEEK_END) <0)3197returnerror("cannot seek back reflog for%s:%s",3198 refname,strerror(errno));3199 pos =ftell(logfp);3200while(!ret &&0< pos) {3201int cnt;3202size_t nread;3203char buf[BUFSIZ];3204char*endp, *scanp;32053206/* Fill next block from the end */3207 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3208if(fseek(logfp, pos - cnt, SEEK_SET))3209returnerror("cannot seek back reflog for%s:%s",3210 refname,strerror(errno));3211 nread =fread(buf, cnt,1, logfp);3212if(nread !=1)3213returnerror("cannot read%dbytes from reflog for%s:%s",3214 cnt, refname,strerror(errno));3215 pos -= cnt;32163217 scanp = endp = buf + cnt;3218if(at_tail && scanp[-1] =='\n')3219/* Looking at the final LF at the end of the file */3220 scanp--;3221 at_tail =0;32223223while(buf < scanp) {3224/*3225 * terminating LF of the previous line, or the beginning3226 * of the buffer.3227 */3228char*bp;32293230 bp =find_beginning_of_line(buf, scanp);32313232if(*bp =='\n') {3233/*3234 * The newline is the end of the previous line,3235 * so we know we have complete line starting3236 * at (bp + 1). Prefix it onto any prior data3237 * we collected for the line and process it.3238 */3239strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3240 scanp = bp;3241 endp = bp +1;3242 ret =show_one_reflog_ent(&sb, fn, cb_data);3243strbuf_reset(&sb);3244if(ret)3245break;3246}else if(!pos) {3247/*3248 * We are at the start of the buffer, and the3249 * start of the file; there is no previous3250 * line, and we have everything for this one.3251 * Process it, and we can end the loop.3252 */3253strbuf_splice(&sb,0,0, buf, endp - buf);3254 ret =show_one_reflog_ent(&sb, fn, cb_data);3255strbuf_reset(&sb);3256break;3257}32583259if(bp == buf) {3260/*3261 * We are at the start of the buffer, and there3262 * is more file to read backwards. Which means3263 * we are in the middle of a line. Note that we3264 * may get here even if *bp was a newline; that3265 * just means we are at the exact end of the3266 * previous line, rather than some spot in the3267 * middle.3268 *3269 * Save away what we have to be combined with3270 * the data from the next read.3271 */3272strbuf_splice(&sb,0,0, buf, endp - buf);3273break;3274}3275}32763277}3278if(!ret && sb.len)3279die("BUG: reverse reflog parser had leftover data");32803281fclose(logfp);3282strbuf_release(&sb);3283return ret;3284}32853286static intfiles_for_each_reflog_ent(struct ref_store *ref_store,3287const char*refname,3288 each_reflog_ent_fn fn,void*cb_data)3289{3290FILE*logfp;3291struct strbuf sb = STRBUF_INIT;3292int ret =0;32933294/* Check validity (but we don't need the result): */3295files_downcast(ref_store,0,"for_each_reflog_ent");32963297 logfp =fopen(git_path("logs/%s", refname),"r");3298if(!logfp)3299return-1;33003301while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3302 ret =show_one_reflog_ent(&sb, fn, cb_data);3303fclose(logfp);3304strbuf_release(&sb);3305return ret;3306}33073308struct files_reflog_iterator {3309struct ref_iterator base;33103311struct dir_iterator *dir_iterator;3312struct object_id oid;3313};33143315static intfiles_reflog_iterator_advance(struct ref_iterator *ref_iterator)3316{3317struct files_reflog_iterator *iter =3318(struct files_reflog_iterator *)ref_iterator;3319struct dir_iterator *diter = iter->dir_iterator;3320int ok;33213322while((ok =dir_iterator_advance(diter)) == ITER_OK) {3323int flags;33243325if(!S_ISREG(diter->st.st_mode))3326continue;3327if(diter->basename[0] =='.')3328continue;3329if(ends_with(diter->basename,".lock"))3330continue;33313332if(read_ref_full(diter->relative_path,0,3333 iter->oid.hash, &flags)) {3334error("bad ref for%s", diter->path.buf);3335continue;3336}33373338 iter->base.refname = diter->relative_path;3339 iter->base.oid = &iter->oid;3340 iter->base.flags = flags;3341return ITER_OK;3342}33433344 iter->dir_iterator = NULL;3345if(ref_iterator_abort(ref_iterator) == ITER_ERROR)3346 ok = ITER_ERROR;3347return ok;3348}33493350static intfiles_reflog_iterator_peel(struct ref_iterator *ref_iterator,3351struct object_id *peeled)3352{3353die("BUG: ref_iterator_peel() called for reflog_iterator");3354}33553356static intfiles_reflog_iterator_abort(struct ref_iterator *ref_iterator)3357{3358struct files_reflog_iterator *iter =3359(struct files_reflog_iterator *)ref_iterator;3360int ok = ITER_DONE;33613362if(iter->dir_iterator)3363 ok =dir_iterator_abort(iter->dir_iterator);33643365base_ref_iterator_free(ref_iterator);3366return ok;3367}33683369static struct ref_iterator_vtable files_reflog_iterator_vtable = {3370 files_reflog_iterator_advance,3371 files_reflog_iterator_peel,3372 files_reflog_iterator_abort3373};33743375static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)3376{3377struct files_reflog_iterator *iter =xcalloc(1,sizeof(*iter));3378struct ref_iterator *ref_iterator = &iter->base;33793380/* Check validity (but we don't need the result): */3381files_downcast(ref_store,0,"reflog_iterator_begin");33823383base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3384 iter->dir_iterator =dir_iterator_begin(git_path("logs"));3385return ref_iterator;3386}33873388static intref_update_reject_duplicates(struct string_list *refnames,3389struct strbuf *err)3390{3391int i, n = refnames->nr;33923393assert(err);33943395for(i =1; i < n; i++)3396if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3397strbuf_addf(err,3398"multiple updates for ref '%s' not allowed.",3399 refnames->items[i].string);3400return1;3401}3402return0;3403}34043405/*3406 * If update is a direct update of head_ref (the reference pointed to3407 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3408 */3409static intsplit_head_update(struct ref_update *update,3410struct ref_transaction *transaction,3411const char*head_ref,3412struct string_list *affected_refnames,3413struct strbuf *err)3414{3415struct string_list_item *item;3416struct ref_update *new_update;34173418if((update->flags & REF_LOG_ONLY) ||3419(update->flags & REF_ISPRUNING) ||3420(update->flags & REF_UPDATE_VIA_HEAD))3421return0;34223423if(strcmp(update->refname, head_ref))3424return0;34253426/*3427 * First make sure that HEAD is not already in the3428 * transaction. This insertion is O(N) in the transaction3429 * size, but it happens at most once per transaction.3430 */3431 item =string_list_insert(affected_refnames,"HEAD");3432if(item->util) {3433/* An entry already existed */3434strbuf_addf(err,3435"multiple updates for 'HEAD' (including one "3436"via its referent '%s') are not allowed",3437 update->refname);3438return TRANSACTION_NAME_CONFLICT;3439}34403441 new_update =ref_transaction_add_update(3442 transaction,"HEAD",3443 update->flags | REF_LOG_ONLY | REF_NODEREF,3444 update->new_sha1, update->old_sha1,3445 update->msg);34463447 item->util = new_update;34483449return0;3450}34513452/*3453 * update is for a symref that points at referent and doesn't have3454 * REF_NODEREF set. Split it into two updates:3455 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3456 * - A new, separate update for the referent reference3457 * Note that the new update will itself be subject to splitting when3458 * the iteration gets to it.3459 */3460static intsplit_symref_update(struct files_ref_store *refs,3461struct ref_update *update,3462const char*referent,3463struct ref_transaction *transaction,3464struct string_list *affected_refnames,3465struct strbuf *err)3466{3467struct string_list_item *item;3468struct ref_update *new_update;3469unsigned int new_flags;34703471/*3472 * First make sure that referent is not already in the3473 * transaction. This insertion is O(N) in the transaction3474 * size, but it happens at most once per symref in a3475 * transaction.3476 */3477 item =string_list_insert(affected_refnames, referent);3478if(item->util) {3479/* An entry already existed */3480strbuf_addf(err,3481"multiple updates for '%s' (including one "3482"via symref '%s') are not allowed",3483 referent, update->refname);3484return TRANSACTION_NAME_CONFLICT;3485}34863487 new_flags = update->flags;3488if(!strcmp(update->refname,"HEAD")) {3489/*3490 * Record that the new update came via HEAD, so that3491 * when we process it, split_head_update() doesn't try3492 * to add another reflog update for HEAD. Note that3493 * this bit will be propagated if the new_update3494 * itself needs to be split.3495 */3496 new_flags |= REF_UPDATE_VIA_HEAD;3497}34983499 new_update =ref_transaction_add_update(3500 transaction, referent, new_flags,3501 update->new_sha1, update->old_sha1,3502 update->msg);35033504 new_update->parent_update = update;35053506/*3507 * Change the symbolic ref update to log only. Also, it3508 * doesn't need to check its old SHA-1 value, as that will be3509 * done when new_update is processed.3510 */3511 update->flags |= REF_LOG_ONLY | REF_NODEREF;3512 update->flags &= ~REF_HAVE_OLD;35133514 item->util = new_update;35153516return0;3517}35183519/*3520 * Return the refname under which update was originally requested.3521 */3522static const char*original_update_refname(struct ref_update *update)3523{3524while(update->parent_update)3525 update = update->parent_update;35263527return update->refname;3528}35293530/*3531 * Check whether the REF_HAVE_OLD and old_oid values stored in update3532 * are consistent with oid, which is the reference's current value. If3533 * everything is OK, return 0; otherwise, write an error message to3534 * err and return -1.3535 */3536static intcheck_old_oid(struct ref_update *update,struct object_id *oid,3537struct strbuf *err)3538{3539if(!(update->flags & REF_HAVE_OLD) ||3540!hashcmp(oid->hash, update->old_sha1))3541return0;35423543if(is_null_sha1(update->old_sha1))3544strbuf_addf(err,"cannot lock ref '%s': "3545"reference already exists",3546original_update_refname(update));3547else if(is_null_oid(oid))3548strbuf_addf(err,"cannot lock ref '%s': "3549"reference is missing but expected%s",3550original_update_refname(update),3551sha1_to_hex(update->old_sha1));3552else3553strbuf_addf(err,"cannot lock ref '%s': "3554"is at%sbut expected%s",3555original_update_refname(update),3556oid_to_hex(oid),3557sha1_to_hex(update->old_sha1));35583559return-1;3560}35613562/*3563 * Prepare for carrying out update:3564 * - Lock the reference referred to by update.3565 * - Read the reference under lock.3566 * - Check that its old SHA-1 value (if specified) is correct, and in3567 * any case record it in update->lock->old_oid for later use when3568 * writing the reflog.3569 * - If it is a symref update without REF_NODEREF, split it up into a3570 * REF_LOG_ONLY update of the symref and add a separate update for3571 * the referent to transaction.3572 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3573 * update of HEAD.3574 */3575static intlock_ref_for_update(struct files_ref_store *refs,3576struct ref_update *update,3577struct ref_transaction *transaction,3578const char*head_ref,3579struct string_list *affected_refnames,3580struct strbuf *err)3581{3582struct strbuf referent = STRBUF_INIT;3583int mustexist = (update->flags & REF_HAVE_OLD) &&3584!is_null_sha1(update->old_sha1);3585int ret;3586struct ref_lock *lock;35873588files_assert_main_repository(refs,"lock_ref_for_update");35893590if((update->flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3591 update->flags |= REF_DELETING;35923593if(head_ref) {3594 ret =split_head_update(update, transaction, head_ref,3595 affected_refnames, err);3596if(ret)3597return ret;3598}35993600 ret =lock_raw_ref(refs, update->refname, mustexist,3601 affected_refnames, NULL,3602&lock, &referent,3603&update->type, err);3604if(ret) {3605char*reason;36063607 reason =strbuf_detach(err, NULL);3608strbuf_addf(err,"cannot lock ref '%s':%s",3609original_update_refname(update), reason);3610free(reason);3611return ret;3612}36133614 update->backend_data = lock;36153616if(update->type & REF_ISSYMREF) {3617if(update->flags & REF_NODEREF) {3618/*3619 * We won't be reading the referent as part of3620 * the transaction, so we have to read it here3621 * to record and possibly check old_sha1:3622 */3623if(read_ref_full(referent.buf,0,3624 lock->old_oid.hash, NULL)) {3625if(update->flags & REF_HAVE_OLD) {3626strbuf_addf(err,"cannot lock ref '%s': "3627"error reading reference",3628original_update_refname(update));3629return-1;3630}3631}else if(check_old_oid(update, &lock->old_oid, err)) {3632return TRANSACTION_GENERIC_ERROR;3633}3634}else{3635/*3636 * Create a new update for the reference this3637 * symref is pointing at. Also, we will record3638 * and verify old_sha1 for this update as part3639 * of processing the split-off update, so we3640 * don't have to do it here.3641 */3642 ret =split_symref_update(refs, update,3643 referent.buf, transaction,3644 affected_refnames, err);3645if(ret)3646return ret;3647}3648}else{3649struct ref_update *parent_update;36503651if(check_old_oid(update, &lock->old_oid, err))3652return TRANSACTION_GENERIC_ERROR;36533654/*3655 * If this update is happening indirectly because of a3656 * symref update, record the old SHA-1 in the parent3657 * update:3658 */3659for(parent_update = update->parent_update;3660 parent_update;3661 parent_update = parent_update->parent_update) {3662struct ref_lock *parent_lock = parent_update->backend_data;3663oidcpy(&parent_lock->old_oid, &lock->old_oid);3664}3665}36663667if((update->flags & REF_HAVE_NEW) &&3668!(update->flags & REF_DELETING) &&3669!(update->flags & REF_LOG_ONLY)) {3670if(!(update->type & REF_ISSYMREF) &&3671!hashcmp(lock->old_oid.hash, update->new_sha1)) {3672/*3673 * The reference already has the desired3674 * value, so we don't need to write it.3675 */3676}else if(write_ref_to_lockfile(lock, update->new_sha1,3677 err)) {3678char*write_err =strbuf_detach(err, NULL);36793680/*3681 * The lock was freed upon failure of3682 * write_ref_to_lockfile():3683 */3684 update->backend_data = NULL;3685strbuf_addf(err,3686"cannot update ref '%s':%s",3687 update->refname, write_err);3688free(write_err);3689return TRANSACTION_GENERIC_ERROR;3690}else{3691 update->flags |= REF_NEEDS_COMMIT;3692}3693}3694if(!(update->flags & REF_NEEDS_COMMIT)) {3695/*3696 * We didn't call write_ref_to_lockfile(), so3697 * the lockfile is still open. Close it to3698 * free up the file descriptor:3699 */3700if(close_ref(lock)) {3701strbuf_addf(err,"couldn't close '%s.lock'",3702 update->refname);3703return TRANSACTION_GENERIC_ERROR;3704}3705}3706return0;3707}37083709static intfiles_transaction_commit(struct ref_store *ref_store,3710struct ref_transaction *transaction,3711struct strbuf *err)3712{3713struct files_ref_store *refs =3714files_downcast(ref_store,0,"ref_transaction_commit");3715int ret =0, i;3716struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3717struct string_list_item *ref_to_delete;3718struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3719char*head_ref = NULL;3720int head_type;3721struct object_id head_oid;37223723assert(err);37243725if(transaction->state != REF_TRANSACTION_OPEN)3726die("BUG: commit called for transaction that is not open");37273728if(!transaction->nr) {3729 transaction->state = REF_TRANSACTION_CLOSED;3730return0;3731}37323733/*3734 * Fail if a refname appears more than once in the3735 * transaction. (If we end up splitting up any updates using3736 * split_symref_update() or split_head_update(), those3737 * functions will check that the new updates don't have the3738 * same refname as any existing ones.)3739 */3740for(i =0; i < transaction->nr; i++) {3741struct ref_update *update = transaction->updates[i];3742struct string_list_item *item =3743string_list_append(&affected_refnames, update->refname);37443745/*3746 * We store a pointer to update in item->util, but at3747 * the moment we never use the value of this field3748 * except to check whether it is non-NULL.3749 */3750 item->util = update;3751}3752string_list_sort(&affected_refnames);3753if(ref_update_reject_duplicates(&affected_refnames, err)) {3754 ret = TRANSACTION_GENERIC_ERROR;3755goto cleanup;3756}37573758/*3759 * Special hack: If a branch is updated directly and HEAD3760 * points to it (may happen on the remote side of a push3761 * for example) then logically the HEAD reflog should be3762 * updated too.3763 *3764 * A generic solution would require reverse symref lookups,3765 * but finding all symrefs pointing to a given branch would be3766 * rather costly for this rare event (the direct update of a3767 * branch) to be worth it. So let's cheat and check with HEAD3768 * only, which should cover 99% of all usage scenarios (even3769 * 100% of the default ones).3770 *3771 * So if HEAD is a symbolic reference, then record the name of3772 * the reference that it points to. If we see an update of3773 * head_ref within the transaction, then split_head_update()3774 * arranges for the reflog of HEAD to be updated, too.3775 */3776 head_ref =resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3777 head_oid.hash, &head_type);37783779if(head_ref && !(head_type & REF_ISSYMREF)) {3780free(head_ref);3781 head_ref = NULL;3782}37833784/*3785 * Acquire all locks, verify old values if provided, check3786 * that new values are valid, and write new values to the3787 * lockfiles, ready to be activated. Only keep one lockfile3788 * open at a time to avoid running out of file descriptors.3789 */3790for(i =0; i < transaction->nr; i++) {3791struct ref_update *update = transaction->updates[i];37923793 ret =lock_ref_for_update(refs, update, transaction,3794 head_ref, &affected_refnames, err);3795if(ret)3796goto cleanup;3797}37983799/* Perform updates first so live commits remain referenced */3800for(i =0; i < transaction->nr; i++) {3801struct ref_update *update = transaction->updates[i];3802struct ref_lock *lock = update->backend_data;38033804if(update->flags & REF_NEEDS_COMMIT ||3805 update->flags & REF_LOG_ONLY) {3806if(log_ref_write(lock->ref_name, lock->old_oid.hash,3807 update->new_sha1,3808 update->msg, update->flags, err)) {3809char*old_msg =strbuf_detach(err, NULL);38103811strbuf_addf(err,"cannot update the ref '%s':%s",3812 lock->ref_name, old_msg);3813free(old_msg);3814unlock_ref(lock);3815 update->backend_data = NULL;3816 ret = TRANSACTION_GENERIC_ERROR;3817goto cleanup;3818}3819}3820if(update->flags & REF_NEEDS_COMMIT) {3821clear_loose_ref_cache(refs);3822if(commit_ref(lock)) {3823strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3824unlock_ref(lock);3825 update->backend_data = NULL;3826 ret = TRANSACTION_GENERIC_ERROR;3827goto cleanup;3828}3829}3830}3831/* Perform deletes now that updates are safely completed */3832for(i =0; i < transaction->nr; i++) {3833struct ref_update *update = transaction->updates[i];3834struct ref_lock *lock = update->backend_data;38353836if(update->flags & REF_DELETING &&3837!(update->flags & REF_LOG_ONLY)) {3838if(delete_ref_loose(lock, update->type, err)) {3839 ret = TRANSACTION_GENERIC_ERROR;3840goto cleanup;3841}38423843if(!(update->flags & REF_ISPRUNING))3844string_list_append(&refs_to_delete,3845 lock->ref_name);3846}3847}38483849if(repack_without_refs(refs, &refs_to_delete, err)) {3850 ret = TRANSACTION_GENERIC_ERROR;3851goto cleanup;3852}3853for_each_string_list_item(ref_to_delete, &refs_to_delete)3854unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3855clear_loose_ref_cache(refs);38563857cleanup:3858 transaction->state = REF_TRANSACTION_CLOSED;38593860for(i =0; i < transaction->nr; i++)3861if(transaction->updates[i]->backend_data)3862unlock_ref(transaction->updates[i]->backend_data);3863string_list_clear(&refs_to_delete,0);3864free(head_ref);3865string_list_clear(&affected_refnames,0);38663867return ret;3868}38693870static intref_present(const char*refname,3871const struct object_id *oid,int flags,void*cb_data)3872{3873struct string_list *affected_refnames = cb_data;38743875returnstring_list_has_string(affected_refnames, refname);3876}38773878static intfiles_initial_transaction_commit(struct ref_store *ref_store,3879struct ref_transaction *transaction,3880struct strbuf *err)3881{3882struct files_ref_store *refs =3883files_downcast(ref_store,0,"initial_ref_transaction_commit");3884int ret =0, i;3885struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38863887assert(err);38883889if(transaction->state != REF_TRANSACTION_OPEN)3890die("BUG: commit called for transaction that is not open");38913892/* Fail if a refname appears more than once in the transaction: */3893for(i =0; i < transaction->nr; i++)3894string_list_append(&affected_refnames,3895 transaction->updates[i]->refname);3896string_list_sort(&affected_refnames);3897if(ref_update_reject_duplicates(&affected_refnames, err)) {3898 ret = TRANSACTION_GENERIC_ERROR;3899goto cleanup;3900}39013902/*3903 * It's really undefined to call this function in an active3904 * repository or when there are existing references: we are3905 * only locking and changing packed-refs, so (1) any3906 * simultaneous processes might try to change a reference at3907 * the same time we do, and (2) any existing loose versions of3908 * the references that we are setting would have precedence3909 * over our values. But some remote helpers create the remote3910 * "HEAD" and "master" branches before calling this function,3911 * so here we really only check that none of the references3912 * that we are creating already exists.3913 */3914if(for_each_rawref(ref_present, &affected_refnames))3915die("BUG: initial ref transaction called with existing refs");39163917for(i =0; i < transaction->nr; i++) {3918struct ref_update *update = transaction->updates[i];39193920if((update->flags & REF_HAVE_OLD) &&3921!is_null_sha1(update->old_sha1))3922die("BUG: initial ref transaction with old_sha1 set");3923if(verify_refname_available(update->refname,3924&affected_refnames, NULL,3925 err)) {3926 ret = TRANSACTION_NAME_CONFLICT;3927goto cleanup;3928}3929}39303931if(lock_packed_refs(refs,0)) {3932strbuf_addf(err,"unable to lock packed-refs file:%s",3933strerror(errno));3934 ret = TRANSACTION_GENERIC_ERROR;3935goto cleanup;3936}39373938for(i =0; i < transaction->nr; i++) {3939struct ref_update *update = transaction->updates[i];39403941if((update->flags & REF_HAVE_NEW) &&3942!is_null_sha1(update->new_sha1))3943add_packed_ref(refs, update->refname, update->new_sha1);3944}39453946if(commit_packed_refs(refs)) {3947strbuf_addf(err,"unable to commit packed-refs file:%s",3948strerror(errno));3949 ret = TRANSACTION_GENERIC_ERROR;3950goto cleanup;3951}39523953cleanup:3954 transaction->state = REF_TRANSACTION_CLOSED;3955string_list_clear(&affected_refnames,0);3956return ret;3957}39583959struct expire_reflog_cb {3960unsigned int flags;3961 reflog_expiry_should_prune_fn *should_prune_fn;3962void*policy_cb;3963FILE*newlog;3964unsigned char last_kept_sha1[20];3965};39663967static intexpire_reflog_ent(unsigned char*osha1,unsigned char*nsha1,3968const char*email,unsigned long timestamp,int tz,3969const char*message,void*cb_data)3970{3971struct expire_reflog_cb *cb = cb_data;3972struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39733974if(cb->flags & EXPIRE_REFLOGS_REWRITE)3975 osha1 = cb->last_kept_sha1;39763977if((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3978 message, policy_cb)) {3979if(!cb->newlog)3980printf("would prune%s", message);3981else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3982printf("prune%s", message);3983}else{3984if(cb->newlog) {3985fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",3986sha1_to_hex(osha1),sha1_to_hex(nsha1),3987 email, timestamp, tz, message);3988hashcpy(cb->last_kept_sha1, nsha1);3989}3990if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3991printf("keep%s", message);3992}3993return0;3994}39953996static intfiles_reflog_expire(struct ref_store *ref_store,3997const char*refname,const unsigned char*sha1,3998unsigned int flags,3999 reflog_expiry_prepare_fn prepare_fn,4000 reflog_expiry_should_prune_fn should_prune_fn,4001 reflog_expiry_cleanup_fn cleanup_fn,4002void*policy_cb_data)4003{4004struct files_ref_store *refs =4005files_downcast(ref_store,0,"reflog_expire");4006static struct lock_file reflog_lock;4007struct expire_reflog_cb cb;4008struct ref_lock *lock;4009char*log_file;4010int status =0;4011int type;4012struct strbuf err = STRBUF_INIT;40134014memset(&cb,0,sizeof(cb));4015 cb.flags = flags;4016 cb.policy_cb = policy_cb_data;4017 cb.should_prune_fn = should_prune_fn;40184019/*4020 * The reflog file is locked by holding the lock on the4021 * reference itself, plus we might need to update the4022 * reference if --updateref was specified:4023 */4024 lock =lock_ref_sha1_basic(refs, refname, sha1,4025 NULL, NULL, REF_NODEREF,4026&type, &err);4027if(!lock) {4028error("cannot lock ref '%s':%s", refname, err.buf);4029strbuf_release(&err);4030return-1;4031}4032if(!reflog_exists(refname)) {4033unlock_ref(lock);4034return0;4035}40364037 log_file =git_pathdup("logs/%s", refname);4038if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4039/*4040 * Even though holding $GIT_DIR/logs/$reflog.lock has4041 * no locking implications, we use the lock_file4042 * machinery here anyway because it does a lot of the4043 * work we need, including cleaning up if the program4044 * exits unexpectedly.4045 */4046if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4047struct strbuf err = STRBUF_INIT;4048unable_to_lock_message(log_file, errno, &err);4049error("%s", err.buf);4050strbuf_release(&err);4051goto failure;4052}4053 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4054if(!cb.newlog) {4055error("cannot fdopen%s(%s)",4056get_lock_file_path(&reflog_lock),strerror(errno));4057goto failure;4058}4059}40604061(*prepare_fn)(refname, sha1, cb.policy_cb);4062for_each_reflog_ent(refname, expire_reflog_ent, &cb);4063(*cleanup_fn)(cb.policy_cb);40644065if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4066/*4067 * It doesn't make sense to adjust a reference pointed4068 * to by a symbolic ref based on expiring entries in4069 * the symbolic reference's reflog. Nor can we update4070 * a reference if there are no remaining reflog4071 * entries.4072 */4073int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4074!(type & REF_ISSYMREF) &&4075!is_null_sha1(cb.last_kept_sha1);40764077if(close_lock_file(&reflog_lock)) {4078 status |=error("couldn't write%s:%s", log_file,4079strerror(errno));4080}else if(update &&4081(write_in_full(get_lock_file_fd(lock->lk),4082sha1_to_hex(cb.last_kept_sha1),40) !=40||4083write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||4084close_ref(lock) <0)) {4085 status |=error("couldn't write%s",4086get_lock_file_path(lock->lk));4087rollback_lock_file(&reflog_lock);4088}else if(commit_lock_file(&reflog_lock)) {4089 status |=error("unable to write reflog '%s' (%s)",4090 log_file,strerror(errno));4091}else if(update &&commit_ref(lock)) {4092 status |=error("couldn't set%s", lock->ref_name);4093}4094}4095free(log_file);4096unlock_ref(lock);4097return status;40984099 failure:4100rollback_lock_file(&reflog_lock);4101free(log_file);4102unlock_ref(lock);4103return-1;4104}41054106static intfiles_init_db(struct ref_store *ref_store,struct strbuf *err)4107{4108/* Check validity (but we don't need the result): */4109files_downcast(ref_store,0,"init_db");41104111/*4112 * Create .git/refs/{heads,tags}4113 */4114safe_create_dir(git_path("refs/heads"),1);4115safe_create_dir(git_path("refs/tags"),1);4116if(get_shared_repository()) {4117adjust_shared_perm(git_path("refs/heads"));4118adjust_shared_perm(git_path("refs/tags"));4119}4120return0;4121}41224123struct ref_storage_be refs_be_files = {4124 NULL,4125"files",4126 files_ref_store_create,4127 files_init_db,4128 files_transaction_commit,4129 files_initial_transaction_commit,41304131 files_pack_refs,4132 files_peel_ref,4133 files_create_symref,4134 files_delete_refs,4135 files_rename_ref,41364137 files_ref_iterator_begin,4138 files_read_raw_ref,4139 files_verify_refname_available,41404141 files_reflog_iterator_begin,4142 files_for_each_reflog_ent,4143 files_for_each_reflog_ent_reverse,4144 files_reflog_exists,4145 files_create_reflog,4146 files_delete_reflog,4147 files_reflog_expire4148};