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,sizeof(*dir->entries), 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; 915struct ref_entry *loose; 916struct packed_ref_cache *packed; 917}; 918 919/* Lock used for the main packed-refs file: */ 920static struct lock_file packlock; 921 922/* 923 * Increment the reference count of *packed_refs. 924 */ 925static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 926{ 927 packed_refs->referrers++; 928} 929 930/* 931 * Decrease the reference count of *packed_refs. If it goes to zero, 932 * free *packed_refs and return true; otherwise return false. 933 */ 934static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 935{ 936if(!--packed_refs->referrers) { 937free_ref_entry(packed_refs->root); 938stat_validity_clear(&packed_refs->validity); 939free(packed_refs); 940return1; 941}else{ 942return0; 943} 944} 945 946static voidclear_packed_ref_cache(struct files_ref_store *refs) 947{ 948if(refs->packed) { 949struct packed_ref_cache *packed_refs = refs->packed; 950 951if(packed_refs->lock) 952die("internal error: packed-ref cache cleared while locked"); 953 refs->packed = NULL; 954release_packed_ref_cache(packed_refs); 955} 956} 957 958static voidclear_loose_ref_cache(struct files_ref_store *refs) 959{ 960if(refs->loose) { 961free_ref_entry(refs->loose); 962 refs->loose = NULL; 963} 964} 965 966/* 967 * Create a new submodule ref cache and add it to the internal 968 * set of caches. 969 */ 970static struct ref_store *files_ref_store_create(const char*submodule) 971{ 972struct files_ref_store *refs =xcalloc(1,sizeof(*refs)); 973struct ref_store *ref_store = (struct ref_store *)refs; 974 975base_ref_store_init(ref_store, &refs_be_files, submodule); 976 977return ref_store; 978} 979 980/* 981 * Downcast ref_store to files_ref_store. Die if ref_store is not a 982 * files_ref_store. If submodule_allowed is not true, then also die if 983 * files_ref_store is for a submodule (i.e., not for the main 984 * repository). caller is used in any necessary error messages. 985 */ 986static struct files_ref_store *files_downcast( 987struct ref_store *ref_store,int submodule_allowed, 988const char*caller) 989{ 990if(ref_store->be != &refs_be_files) 991die("BUG: ref_store is type\"%s\"not\"files\"in%s", 992 ref_store->be->name, caller); 993 994if(!submodule_allowed) 995assert_main_repository(ref_store, caller); 996 997return(struct files_ref_store *)ref_store; 998} 9991000/* The length of a peeled reference line in packed-refs, including EOL: */1001#define PEELED_LINE_LENGTH 4210021003/*1004 * The packed-refs header line that we write out. Perhaps other1005 * traits will be added later. The trailing space is required.1006 */1007static const char PACKED_REFS_HEADER[] =1008"# pack-refs with: peeled fully-peeled\n";10091010/*1011 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1012 * Return a pointer to the refname within the line (null-terminated),1013 * or NULL if there was a problem.1014 */1015static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1016{1017const char*ref;10181019/*1020 * 42: the answer to everything.1021 *1022 * In this case, it happens to be the answer to1023 * 40 (length of sha1 hex representation)1024 * +1 (space in between hex and name)1025 * +1 (newline at the end of the line)1026 */1027if(line->len <=42)1028return NULL;10291030if(get_sha1_hex(line->buf, sha1) <0)1031return NULL;1032if(!isspace(line->buf[40]))1033return NULL;10341035 ref = line->buf +41;1036if(isspace(*ref))1037return NULL;10381039if(line->buf[line->len -1] !='\n')1040return NULL;1041 line->buf[--line->len] =0;10421043return ref;1044}10451046/*1047 * Read f, which is a packed-refs file, into dir.1048 *1049 * A comment line of the form "# pack-refs with: " may contain zero or1050 * more traits. We interpret the traits as follows:1051 *1052 * No traits:1053 *1054 * Probably no references are peeled. But if the file contains a1055 * peeled value for a reference, we will use it.1056 *1057 * peeled:1058 *1059 * References under "refs/tags/", if they *can* be peeled, *are*1060 * peeled in this file. References outside of "refs/tags/" are1061 * probably not peeled even if they could have been, but if we find1062 * a peeled value for such a reference we will use it.1063 *1064 * fully-peeled:1065 *1066 * All references in the file that can be peeled are peeled.1067 * Inversely (and this is more important), any references in the1068 * file for which no peeled value is recorded is not peelable. This1069 * trait should typically be written alongside "peeled" for1070 * compatibility with older clients, but we do not require it1071 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1072 */1073static voidread_packed_refs(FILE*f,struct ref_dir *dir)1074{1075struct ref_entry *last = NULL;1076struct strbuf line = STRBUF_INIT;1077enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10781079while(strbuf_getwholeline(&line, f,'\n') != EOF) {1080unsigned char sha1[20];1081const char*refname;1082const char*traits;10831084if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1085if(strstr(traits," fully-peeled "))1086 peeled = PEELED_FULLY;1087else if(strstr(traits," peeled "))1088 peeled = PEELED_TAGS;1089/* perhaps other traits later as well */1090continue;1091}10921093 refname =parse_ref_line(&line, sha1);1094if(refname) {1095int flag = REF_ISPACKED;10961097if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1098if(!refname_is_safe(refname))1099die("packed refname is dangerous:%s", refname);1100hashclr(sha1);1101 flag |= REF_BAD_NAME | REF_ISBROKEN;1102}1103 last =create_ref_entry(refname, sha1, flag,0);1104if(peeled == PEELED_FULLY ||1105(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1106 last->flag |= REF_KNOWS_PEELED;1107add_ref(dir, last);1108continue;1109}1110if(last &&1111 line.buf[0] =='^'&&1112 line.len == PEELED_LINE_LENGTH &&1113 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1114!get_sha1_hex(line.buf +1, sha1)) {1115hashcpy(last->u.value.peeled.hash, sha1);1116/*1117 * Regardless of what the file header said,1118 * we definitely know the value of *this*1119 * reference:1120 */1121 last->flag |= REF_KNOWS_PEELED;1122}1123}11241125strbuf_release(&line);1126}11271128/*1129 * Get the packed_ref_cache for the specified files_ref_store,1130 * creating it if necessary.1131 */1132static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1133{1134char*packed_refs_file;11351136if(*refs->base.submodule)1137 packed_refs_file =git_pathdup_submodule(refs->base.submodule,1138"packed-refs");1139else1140 packed_refs_file =git_pathdup("packed-refs");11411142if(refs->packed &&1143!stat_validity_check(&refs->packed->validity, packed_refs_file))1144clear_packed_ref_cache(refs);11451146if(!refs->packed) {1147FILE*f;11481149 refs->packed =xcalloc(1,sizeof(*refs->packed));1150acquire_packed_ref_cache(refs->packed);1151 refs->packed->root =create_dir_entry(refs,"",0,0);1152 f =fopen(packed_refs_file,"r");1153if(f) {1154stat_validity_update(&refs->packed->validity,fileno(f));1155read_packed_refs(f,get_ref_dir(refs->packed->root));1156fclose(f);1157}1158}1159free(packed_refs_file);1160return refs->packed;1161}11621163static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1164{1165returnget_ref_dir(packed_ref_cache->root);1166}11671168static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1169{1170returnget_packed_ref_dir(get_packed_ref_cache(refs));1171}11721173/*1174 * Add a reference to the in-memory packed reference cache. This may1175 * only be called while the packed-refs file is locked (see1176 * lock_packed_refs()). To actually write the packed-refs file, call1177 * commit_packed_refs().1178 */1179static voidadd_packed_ref(struct files_ref_store *refs,1180const char*refname,const unsigned char*sha1)1181{1182struct packed_ref_cache *packed_ref_cache =get_packed_ref_cache(refs);11831184if(!packed_ref_cache->lock)1185die("internal error: packed refs not locked");1186add_ref(get_packed_ref_dir(packed_ref_cache),1187create_ref_entry(refname, sha1, REF_ISPACKED,1));1188}11891190/*1191 * Read the loose references from the namespace dirname into dir1192 * (without recursing). dirname must end with '/'. dir must be the1193 * directory entry corresponding to dirname.1194 */1195static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1196{1197struct files_ref_store *refs = dir->ref_store;1198DIR*d;1199struct dirent *de;1200int dirnamelen =strlen(dirname);1201struct strbuf refname;1202struct strbuf path = STRBUF_INIT;1203size_t path_baselen;1204int err =0;12051206if(*refs->base.submodule)1207 err =strbuf_git_path_submodule(&path, refs->base.submodule,"%s", dirname);1208else1209strbuf_git_path(&path,"%s", dirname);1210 path_baselen = path.len;12111212if(err) {1213strbuf_release(&path);1214return;1215}12161217 d =opendir(path.buf);1218if(!d) {1219strbuf_release(&path);1220return;1221}12221223strbuf_init(&refname, dirnamelen +257);1224strbuf_add(&refname, dirname, dirnamelen);12251226while((de =readdir(d)) != NULL) {1227unsigned char sha1[20];1228struct stat st;1229int flag;12301231if(de->d_name[0] =='.')1232continue;1233if(ends_with(de->d_name,".lock"))1234continue;1235strbuf_addstr(&refname, de->d_name);1236strbuf_addstr(&path, de->d_name);1237if(stat(path.buf, &st) <0) {1238;/* silently ignore */1239}else if(S_ISDIR(st.st_mode)) {1240strbuf_addch(&refname,'/');1241add_entry_to_dir(dir,1242create_dir_entry(refs, refname.buf,1243 refname.len,1));1244}else{1245int read_ok;12461247if(*refs->base.submodule) {1248hashclr(sha1);1249 flag =0;1250 read_ok = !resolve_gitlink_ref(refs->base.submodule,1251 refname.buf, sha1);1252}else{1253 read_ok = !read_ref_full(refname.buf,1254 RESOLVE_REF_READING,1255 sha1, &flag);1256}12571258if(!read_ok) {1259hashclr(sha1);1260 flag |= REF_ISBROKEN;1261}else if(is_null_sha1(sha1)) {1262/*1263 * It is so astronomically unlikely1264 * that NULL_SHA1 is the SHA-1 of an1265 * actual object that we consider its1266 * appearance in a loose reference1267 * file to be repo corruption1268 * (probably due to a software bug).1269 */1270 flag |= REF_ISBROKEN;1271}12721273if(check_refname_format(refname.buf,1274 REFNAME_ALLOW_ONELEVEL)) {1275if(!refname_is_safe(refname.buf))1276die("loose refname is dangerous:%s", refname.buf);1277hashclr(sha1);1278 flag |= REF_BAD_NAME | REF_ISBROKEN;1279}1280add_entry_to_dir(dir,1281create_ref_entry(refname.buf, sha1, flag,0));1282}1283strbuf_setlen(&refname, dirnamelen);1284strbuf_setlen(&path, path_baselen);1285}1286strbuf_release(&refname);1287strbuf_release(&path);1288closedir(d);1289}12901291static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1292{1293if(!refs->loose) {1294/*1295 * Mark the top-level directory complete because we1296 * are about to read the only subdirectory that can1297 * hold references:1298 */1299 refs->loose =create_dir_entry(refs,"",0,0);1300/*1301 * Create an incomplete entry for "refs/":1302 */1303add_entry_to_dir(get_ref_dir(refs->loose),1304create_dir_entry(refs,"refs/",5,1));1305}1306returnget_ref_dir(refs->loose);1307}13081309/*1310 * Return the ref_entry for the given refname from the packed1311 * references. If it does not exist, return NULL.1312 */1313static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1314const char*refname)1315{1316returnfind_ref(get_packed_refs(refs), refname);1317}13181319/*1320 * A loose ref file doesn't exist; check for a packed ref.1321 */1322static intresolve_packed_ref(struct files_ref_store *refs,1323const char*refname,1324unsigned char*sha1,unsigned int*flags)1325{1326struct ref_entry *entry;13271328/*1329 * The loose reference file does not exist; check for a packed1330 * reference.1331 */1332 entry =get_packed_ref(refs, refname);1333if(entry) {1334hashcpy(sha1, entry->u.value.oid.hash);1335*flags |= REF_ISPACKED;1336return0;1337}1338/* refname is not a packed reference. */1339return-1;1340}13411342static intfiles_read_raw_ref(struct ref_store *ref_store,1343const char*refname,unsigned char*sha1,1344struct strbuf *referent,unsigned int*type)1345{1346struct files_ref_store *refs =1347files_downcast(ref_store,1,"read_raw_ref");1348struct strbuf sb_contents = STRBUF_INIT;1349struct strbuf sb_path = STRBUF_INIT;1350const char*path;1351const char*buf;1352struct stat st;1353int fd;1354int ret = -1;1355int save_errno;13561357*type =0;1358strbuf_reset(&sb_path);13591360if(*refs->base.submodule)1361strbuf_git_path_submodule(&sb_path, refs->base.submodule,"%s", refname);1362else1363strbuf_git_path(&sb_path,"%s", refname);13641365 path = sb_path.buf;13661367stat_ref:1368/*1369 * We might have to loop back here to avoid a race1370 * condition: first we lstat() the file, then we try1371 * to read it as a link or as a file. But if somebody1372 * changes the type of the file (file <-> directory1373 * <-> symlink) between the lstat() and reading, then1374 * we don't want to report that as an error but rather1375 * try again starting with the lstat().1376 */13771378if(lstat(path, &st) <0) {1379if(errno != ENOENT)1380goto out;1381if(resolve_packed_ref(refs, refname, sha1, type)) {1382 errno = ENOENT;1383goto out;1384}1385 ret =0;1386goto out;1387}13881389/* Follow "normalized" - ie "refs/.." symlinks by hand */1390if(S_ISLNK(st.st_mode)) {1391strbuf_reset(&sb_contents);1392if(strbuf_readlink(&sb_contents, path,0) <0) {1393if(errno == ENOENT || errno == EINVAL)1394/* inconsistent with lstat; retry */1395goto stat_ref;1396else1397goto out;1398}1399if(starts_with(sb_contents.buf,"refs/") &&1400!check_refname_format(sb_contents.buf,0)) {1401strbuf_swap(&sb_contents, referent);1402*type |= REF_ISSYMREF;1403 ret =0;1404goto out;1405}1406}14071408/* Is it a directory? */1409if(S_ISDIR(st.st_mode)) {1410/*1411 * Even though there is a directory where the loose1412 * ref is supposed to be, there could still be a1413 * packed ref:1414 */1415if(resolve_packed_ref(refs, refname, sha1, type)) {1416 errno = EISDIR;1417goto out;1418}1419 ret =0;1420goto out;1421}14221423/*1424 * Anything else, just open it and try to use it as1425 * a ref1426 */1427 fd =open(path, O_RDONLY);1428if(fd <0) {1429if(errno == ENOENT)1430/* inconsistent with lstat; retry */1431goto stat_ref;1432else1433goto out;1434}1435strbuf_reset(&sb_contents);1436if(strbuf_read(&sb_contents, fd,256) <0) {1437int save_errno = errno;1438close(fd);1439 errno = save_errno;1440goto out;1441}1442close(fd);1443strbuf_rtrim(&sb_contents);1444 buf = sb_contents.buf;1445if(starts_with(buf,"ref:")) {1446 buf +=4;1447while(isspace(*buf))1448 buf++;14491450strbuf_reset(referent);1451strbuf_addstr(referent, buf);1452*type |= REF_ISSYMREF;1453 ret =0;1454goto out;1455}14561457/*1458 * Please note that FETCH_HEAD has additional1459 * data after the sha.1460 */1461if(get_sha1_hex(buf, sha1) ||1462(buf[40] !='\0'&& !isspace(buf[40]))) {1463*type |= REF_ISBROKEN;1464 errno = EINVAL;1465goto out;1466}14671468 ret =0;14691470out:1471 save_errno = errno;1472strbuf_release(&sb_path);1473strbuf_release(&sb_contents);1474 errno = save_errno;1475return ret;1476}14771478static voidunlock_ref(struct ref_lock *lock)1479{1480/* Do not free lock->lk -- atexit() still looks at them */1481if(lock->lk)1482rollback_lock_file(lock->lk);1483free(lock->ref_name);1484free(lock);1485}14861487/*1488 * Lock refname, without following symrefs, and set *lock_p to point1489 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1490 * and type similarly to read_raw_ref().1491 *1492 * The caller must verify that refname is a "safe" reference name (in1493 * the sense of refname_is_safe()) before calling this function.1494 *1495 * If the reference doesn't already exist, verify that refname doesn't1496 * have a D/F conflict with any existing references. extras and skip1497 * are passed to verify_refname_available_dir() for this check.1498 *1499 * If mustexist is not set and the reference is not found or is1500 * broken, lock the reference anyway but clear sha1.1501 *1502 * Return 0 on success. On failure, write an error message to err and1503 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1504 *1505 * Implementation note: This function is basically1506 *1507 * lock reference1508 * read_raw_ref()1509 *1510 * but it includes a lot more code to1511 * - Deal with possible races with other processes1512 * - Avoid calling verify_refname_available_dir() when it can be1513 * avoided, namely if we were successfully able to read the ref1514 * - Generate informative error messages in the case of failure1515 */1516static intlock_raw_ref(struct files_ref_store *refs,1517const char*refname,int mustexist,1518const struct string_list *extras,1519const struct string_list *skip,1520struct ref_lock **lock_p,1521struct strbuf *referent,1522unsigned int*type,1523struct strbuf *err)1524{1525struct ref_lock *lock;1526struct strbuf ref_file = STRBUF_INIT;1527int attempts_remaining =3;1528int ret = TRANSACTION_GENERIC_ERROR;15291530assert(err);1531assert_main_repository(&refs->base,"lock_raw_ref");15321533*type =0;15341535/* First lock the file so it can't change out from under us. */15361537*lock_p = lock =xcalloc(1,sizeof(*lock));15381539 lock->ref_name =xstrdup(refname);1540strbuf_git_path(&ref_file,"%s", refname);15411542retry:1543switch(safe_create_leading_directories(ref_file.buf)) {1544case SCLD_OK:1545break;/* success */1546case SCLD_EXISTS:1547/*1548 * Suppose refname is "refs/foo/bar". We just failed1549 * to create the containing directory, "refs/foo",1550 * because there was a non-directory in the way. This1551 * indicates a D/F conflict, probably because of1552 * another reference such as "refs/foo". There is no1553 * reason to expect this error to be transitory.1554 */1555if(verify_refname_available(refname, extras, skip, err)) {1556if(mustexist) {1557/*1558 * To the user the relevant error is1559 * that the "mustexist" reference is1560 * missing:1561 */1562strbuf_reset(err);1563strbuf_addf(err,"unable to resolve reference '%s'",1564 refname);1565}else{1566/*1567 * The error message set by1568 * verify_refname_available_dir() is OK.1569 */1570 ret = TRANSACTION_NAME_CONFLICT;1571}1572}else{1573/*1574 * The file that is in the way isn't a loose1575 * reference. Report it as a low-level1576 * failure.1577 */1578strbuf_addf(err,"unable to create lock file%s.lock; "1579"non-directory in the way",1580 ref_file.buf);1581}1582goto error_return;1583case SCLD_VANISHED:1584/* Maybe another process was tidying up. Try again. */1585if(--attempts_remaining >0)1586goto retry;1587/* fall through */1588default:1589strbuf_addf(err,"unable to create directory for%s",1590 ref_file.buf);1591goto error_return;1592}15931594if(!lock->lk)1595 lock->lk =xcalloc(1,sizeof(struct lock_file));15961597if(hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) <0) {1598if(errno == ENOENT && --attempts_remaining >0) {1599/*1600 * Maybe somebody just deleted one of the1601 * directories leading to ref_file. Try1602 * again:1603 */1604goto retry;1605}else{1606unable_to_lock_message(ref_file.buf, errno, err);1607goto error_return;1608}1609}16101611/*1612 * Now we hold the lock and can read the reference without1613 * fear that its value will change.1614 */16151616if(files_read_raw_ref(&refs->base, refname,1617 lock->old_oid.hash, referent, type)) {1618if(errno == ENOENT) {1619if(mustexist) {1620/* Garden variety missing reference. */1621strbuf_addf(err,"unable to resolve reference '%s'",1622 refname);1623goto error_return;1624}else{1625/*1626 * Reference is missing, but that's OK. We1627 * know that there is not a conflict with1628 * another loose reference because1629 * (supposing that we are trying to lock1630 * reference "refs/foo/bar"):1631 *1632 * - We were successfully able to create1633 * the lockfile refs/foo/bar.lock, so we1634 * know there cannot be a loose reference1635 * named "refs/foo".1636 *1637 * - We got ENOENT and not EISDIR, so we1638 * know that there cannot be a loose1639 * reference named "refs/foo/bar/baz".1640 */1641}1642}else if(errno == EISDIR) {1643/*1644 * There is a directory in the way. It might have1645 * contained references that have been deleted. If1646 * we don't require that the reference already1647 * exists, try to remove the directory so that it1648 * doesn't cause trouble when we want to rename the1649 * lockfile into place later.1650 */1651if(mustexist) {1652/* Garden variety missing reference. */1653strbuf_addf(err,"unable to resolve reference '%s'",1654 refname);1655goto error_return;1656}else if(remove_dir_recursively(&ref_file,1657 REMOVE_DIR_EMPTY_ONLY)) {1658if(verify_refname_available_dir(1659 refname, extras, skip,1660get_loose_refs(refs),1661 err)) {1662/*1663 * The error message set by1664 * verify_refname_available() is OK.1665 */1666 ret = TRANSACTION_NAME_CONFLICT;1667goto error_return;1668}else{1669/*1670 * We can't delete the directory,1671 * but we also don't know of any1672 * references that it should1673 * contain.1674 */1675strbuf_addf(err,"there is a non-empty directory '%s' "1676"blocking reference '%s'",1677 ref_file.buf, refname);1678goto error_return;1679}1680}1681}else if(errno == EINVAL && (*type & REF_ISBROKEN)) {1682strbuf_addf(err,"unable to resolve reference '%s': "1683"reference broken", refname);1684goto error_return;1685}else{1686strbuf_addf(err,"unable to resolve reference '%s':%s",1687 refname,strerror(errno));1688goto error_return;1689}16901691/*1692 * If the ref did not exist and we are creating it,1693 * make sure there is no existing packed ref whose1694 * name begins with our refname, nor a packed ref1695 * whose name is a proper prefix of our refname.1696 */1697if(verify_refname_available_dir(1698 refname, extras, skip,1699get_packed_refs(refs),1700 err)) {1701goto error_return;1702}1703}17041705 ret =0;1706goto out;17071708error_return:1709unlock_ref(lock);1710*lock_p = NULL;17111712out:1713strbuf_release(&ref_file);1714return ret;1715}17161717/*1718 * Peel the entry (if possible) and return its new peel_status. If1719 * repeel is true, re-peel the entry even if there is an old peeled1720 * value that is already stored in it.1721 *1722 * It is OK to call this function with a packed reference entry that1723 * might be stale and might even refer to an object that has since1724 * been garbage-collected. In such a case, if the entry has1725 * REF_KNOWS_PEELED then leave the status unchanged and return1726 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1727 */1728static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1729{1730enum peel_status status;17311732if(entry->flag & REF_KNOWS_PEELED) {1733if(repeel) {1734 entry->flag &= ~REF_KNOWS_PEELED;1735oidclr(&entry->u.value.peeled);1736}else{1737returnis_null_oid(&entry->u.value.peeled) ?1738 PEEL_NON_TAG : PEEL_PEELED;1739}1740}1741if(entry->flag & REF_ISBROKEN)1742return PEEL_BROKEN;1743if(entry->flag & REF_ISSYMREF)1744return PEEL_IS_SYMREF;17451746 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1747if(status == PEEL_PEELED || status == PEEL_NON_TAG)1748 entry->flag |= REF_KNOWS_PEELED;1749return status;1750}17511752static intfiles_peel_ref(struct ref_store *ref_store,1753const char*refname,unsigned char*sha1)1754{1755struct files_ref_store *refs =files_downcast(ref_store,0,"peel_ref");1756int flag;1757unsigned char base[20];17581759if(current_ref_iter && current_ref_iter->refname == refname) {1760struct object_id peeled;17611762if(ref_iterator_peel(current_ref_iter, &peeled))1763return-1;1764hashcpy(sha1, peeled.hash);1765return0;1766}17671768if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1769return-1;17701771/*1772 * If the reference is packed, read its ref_entry from the1773 * cache in the hope that we already know its peeled value.1774 * We only try this optimization on packed references because1775 * (a) forcing the filling of the loose reference cache could1776 * be expensive and (b) loose references anyway usually do not1777 * have REF_KNOWS_PEELED.1778 */1779if(flag & REF_ISPACKED) {1780struct ref_entry *r =get_packed_ref(refs, refname);1781if(r) {1782if(peel_entry(r,0))1783return-1;1784hashcpy(sha1, r->u.value.peeled.hash);1785return0;1786}1787}17881789returnpeel_object(base, sha1);1790}17911792struct files_ref_iterator {1793struct ref_iterator base;17941795struct packed_ref_cache *packed_ref_cache;1796struct ref_iterator *iter0;1797unsigned int flags;1798};17991800static intfiles_ref_iterator_advance(struct ref_iterator *ref_iterator)1801{1802struct files_ref_iterator *iter =1803(struct files_ref_iterator *)ref_iterator;1804int ok;18051806while((ok =ref_iterator_advance(iter->iter0)) == ITER_OK) {1807if(iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&1808ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1809continue;18101811if(!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1812!ref_resolves_to_object(iter->iter0->refname,1813 iter->iter0->oid,1814 iter->iter0->flags))1815continue;18161817 iter->base.refname = iter->iter0->refname;1818 iter->base.oid = iter->iter0->oid;1819 iter->base.flags = iter->iter0->flags;1820return ITER_OK;1821}18221823 iter->iter0 = NULL;1824if(ref_iterator_abort(ref_iterator) != ITER_DONE)1825 ok = ITER_ERROR;18261827return ok;1828}18291830static intfiles_ref_iterator_peel(struct ref_iterator *ref_iterator,1831struct object_id *peeled)1832{1833struct files_ref_iterator *iter =1834(struct files_ref_iterator *)ref_iterator;18351836returnref_iterator_peel(iter->iter0, peeled);1837}18381839static intfiles_ref_iterator_abort(struct ref_iterator *ref_iterator)1840{1841struct files_ref_iterator *iter =1842(struct files_ref_iterator *)ref_iterator;1843int ok = ITER_DONE;18441845if(iter->iter0)1846 ok =ref_iterator_abort(iter->iter0);18471848release_packed_ref_cache(iter->packed_ref_cache);1849base_ref_iterator_free(ref_iterator);1850return ok;1851}18521853static struct ref_iterator_vtable files_ref_iterator_vtable = {1854 files_ref_iterator_advance,1855 files_ref_iterator_peel,1856 files_ref_iterator_abort1857};18581859static struct ref_iterator *files_ref_iterator_begin(1860struct ref_store *ref_store,1861const char*prefix,unsigned int flags)1862{1863struct files_ref_store *refs =1864files_downcast(ref_store,1,"ref_iterator_begin");1865struct ref_dir *loose_dir, *packed_dir;1866struct ref_iterator *loose_iter, *packed_iter;1867struct files_ref_iterator *iter;1868struct ref_iterator *ref_iterator;18691870if(!refs)1871returnempty_ref_iterator_begin();18721873if(ref_paranoia <0)1874 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1875if(ref_paranoia)1876 flags |= DO_FOR_EACH_INCLUDE_BROKEN;18771878 iter =xcalloc(1,sizeof(*iter));1879 ref_iterator = &iter->base;1880base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);18811882/*1883 * We must make sure that all loose refs are read before1884 * accessing the packed-refs file; this avoids a race1885 * condition if loose refs are migrated to the packed-refs1886 * file by a simultaneous process, but our in-memory view is1887 * from before the migration. We ensure this as follows:1888 * First, we call prime_ref_dir(), which pre-reads the loose1889 * references for the subtree into the cache. (If they've1890 * already been read, that's OK; we only need to guarantee1891 * that they're read before the packed refs, not *how much*1892 * before.) After that, we call get_packed_ref_cache(), which1893 * internally checks whether the packed-ref cache is up to1894 * date with what is on disk, and re-reads it if not.1895 */18961897 loose_dir =get_loose_refs(refs);18981899if(prefix && *prefix)1900 loose_dir =find_containing_dir(loose_dir, prefix,0);19011902if(loose_dir) {1903prime_ref_dir(loose_dir);1904 loose_iter =cache_ref_iterator_begin(loose_dir);1905}else{1906/* There's nothing to iterate over. */1907 loose_iter =empty_ref_iterator_begin();1908}19091910 iter->packed_ref_cache =get_packed_ref_cache(refs);1911acquire_packed_ref_cache(iter->packed_ref_cache);1912 packed_dir =get_packed_ref_dir(iter->packed_ref_cache);19131914if(prefix && *prefix)1915 packed_dir =find_containing_dir(packed_dir, prefix,0);19161917if(packed_dir) {1918 packed_iter =cache_ref_iterator_begin(packed_dir);1919}else{1920/* There's nothing to iterate over. */1921 packed_iter =empty_ref_iterator_begin();1922}19231924 iter->iter0 =overlay_ref_iterator_begin(loose_iter, packed_iter);1925 iter->flags = flags;19261927return ref_iterator;1928}19291930/*1931 * Verify that the reference locked by lock has the value old_sha1.1932 * Fail if the reference doesn't exist and mustexist is set. Return 01933 * on success. On error, write an error message to err, set errno, and1934 * return a negative value.1935 */1936static intverify_lock(struct ref_lock *lock,1937const unsigned char*old_sha1,int mustexist,1938struct strbuf *err)1939{1940assert(err);19411942if(read_ref_full(lock->ref_name,1943 mustexist ? RESOLVE_REF_READING :0,1944 lock->old_oid.hash, NULL)) {1945if(old_sha1) {1946int save_errno = errno;1947strbuf_addf(err,"can't verify ref '%s'", lock->ref_name);1948 errno = save_errno;1949return-1;1950}else{1951oidclr(&lock->old_oid);1952return0;1953}1954}1955if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {1956strbuf_addf(err,"ref '%s' is at%sbut expected%s",1957 lock->ref_name,1958oid_to_hex(&lock->old_oid),1959sha1_to_hex(old_sha1));1960 errno = EBUSY;1961return-1;1962}1963return0;1964}19651966static intremove_empty_directories(struct strbuf *path)1967{1968/*1969 * we want to create a file but there is a directory there;1970 * if that is an empty directory (or a directory that contains1971 * only empty directories), remove them.1972 */1973returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1974}19751976/*1977 * Locks a ref returning the lock on success and NULL on failure.1978 * On failure errno is set to something meaningful.1979 */1980static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,1981const char*refname,1982const unsigned char*old_sha1,1983const struct string_list *extras,1984const struct string_list *skip,1985unsigned int flags,int*type,1986struct strbuf *err)1987{1988struct strbuf ref_file = STRBUF_INIT;1989struct ref_lock *lock;1990int last_errno =0;1991int lflags = LOCK_NO_DEREF;1992int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1993int resolve_flags = RESOLVE_REF_NO_RECURSE;1994int attempts_remaining =3;1995int resolved;19961997assert_main_repository(&refs->base,"lock_ref_sha1_basic");1998assert(err);19992000 lock =xcalloc(1,sizeof(struct ref_lock));20012002if(mustexist)2003 resolve_flags |= RESOLVE_REF_READING;2004if(flags & REF_DELETING)2005 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20062007strbuf_git_path(&ref_file,"%s", refname);2008 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2009 lock->old_oid.hash, type);2010if(!resolved && errno == EISDIR) {2011/*2012 * we are trying to lock foo but we used to2013 * have foo/bar which now does not exist;2014 * it is normal for the empty directory 'foo'2015 * to remain.2016 */2017if(remove_empty_directories(&ref_file)) {2018 last_errno = errno;2019if(!verify_refname_available_dir(2020 refname, extras, skip,2021get_loose_refs(refs), err))2022strbuf_addf(err,"there are still refs under '%s'",2023 refname);2024goto error_return;2025}2026 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2027 lock->old_oid.hash, type);2028}2029if(!resolved) {2030 last_errno = errno;2031if(last_errno != ENOTDIR ||2032!verify_refname_available_dir(2033 refname, extras, skip,2034get_loose_refs(refs), err))2035strbuf_addf(err,"unable to resolve reference '%s':%s",2036 refname,strerror(last_errno));20372038goto error_return;2039}20402041/*2042 * If the ref did not exist and we are creating it, make sure2043 * there is no existing packed ref whose name begins with our2044 * refname, nor a packed ref whose name is a proper prefix of2045 * our refname.2046 */2047if(is_null_oid(&lock->old_oid) &&2048verify_refname_available_dir(refname, extras, skip,2049get_packed_refs(refs),2050 err)) {2051 last_errno = ENOTDIR;2052goto error_return;2053}20542055 lock->lk =xcalloc(1,sizeof(struct lock_file));20562057 lock->ref_name =xstrdup(refname);20582059 retry:2060switch(safe_create_leading_directories_const(ref_file.buf)) {2061case SCLD_OK:2062break;/* success */2063case SCLD_VANISHED:2064if(--attempts_remaining >0)2065goto retry;2066/* fall through */2067default:2068 last_errno = errno;2069strbuf_addf(err,"unable to create directory for '%s'",2070 ref_file.buf);2071goto error_return;2072}20732074if(hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) <0) {2075 last_errno = errno;2076if(errno == ENOENT && --attempts_remaining >0)2077/*2078 * Maybe somebody just deleted one of the2079 * directories leading to ref_file. Try2080 * again:2081 */2082goto retry;2083else{2084unable_to_lock_message(ref_file.buf, errno, err);2085goto error_return;2086}2087}2088if(verify_lock(lock, old_sha1, mustexist, err)) {2089 last_errno = errno;2090goto error_return;2091}2092goto out;20932094 error_return:2095unlock_ref(lock);2096 lock = NULL;20972098 out:2099strbuf_release(&ref_file);2100 errno = last_errno;2101return lock;2102}21032104/*2105 * Write an entry to the packed-refs file for the specified refname.2106 * If peeled is non-NULL, write it as the entry's peeled value.2107 */2108static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2109unsigned char*peeled)2110{2111fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2112if(peeled)2113fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2114}21152116/*2117 * An each_ref_entry_fn that writes the entry to a packed-refs file.2118 */2119static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2120{2121enum peel_status peel_status =peel_entry(entry,0);21222123if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2124error("internal error:%sis not a valid packed reference!",2125 entry->name);2126write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2127 peel_status == PEEL_PEELED ?2128 entry->u.value.peeled.hash : NULL);2129return0;2130}21312132/*2133 * Lock the packed-refs file for writing. Flags is passed to2134 * hold_lock_file_for_update(). Return 0 on success. On errors, set2135 * errno appropriately and return a nonzero value.2136 */2137static intlock_packed_refs(struct files_ref_store *refs,int flags)2138{2139static int timeout_configured =0;2140static int timeout_value =1000;2141struct packed_ref_cache *packed_ref_cache;21422143assert_main_repository(&refs->base,"lock_packed_refs");21442145if(!timeout_configured) {2146git_config_get_int("core.packedrefstimeout", &timeout_value);2147 timeout_configured =1;2148}21492150if(hold_lock_file_for_update_timeout(2151&packlock,git_path("packed-refs"),2152 flags, timeout_value) <0)2153return-1;2154/*2155 * Get the current packed-refs while holding the lock. If the2156 * packed-refs file has been modified since we last read it,2157 * this will automatically invalidate the cache and re-read2158 * the packed-refs file.2159 */2160 packed_ref_cache =get_packed_ref_cache(refs);2161 packed_ref_cache->lock = &packlock;2162/* Increment the reference count to prevent it from being freed: */2163acquire_packed_ref_cache(packed_ref_cache);2164return0;2165}21662167/*2168 * Write the current version of the packed refs cache from memory to2169 * disk. The packed-refs file must already be locked for writing (see2170 * lock_packed_refs()). Return zero on success. On errors, set errno2171 * and return a nonzero value2172 */2173static intcommit_packed_refs(struct files_ref_store *refs)2174{2175struct packed_ref_cache *packed_ref_cache =2176get_packed_ref_cache(refs);2177int error =0;2178int save_errno =0;2179FILE*out;21802181assert_main_repository(&refs->base,"commit_packed_refs");21822183if(!packed_ref_cache->lock)2184die("internal error: packed-refs not locked");21852186 out =fdopen_lock_file(packed_ref_cache->lock,"w");2187if(!out)2188die_errno("unable to fdopen packed-refs descriptor");21892190fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2191do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),21920, write_packed_entry_fn, out);21932194if(commit_lock_file(packed_ref_cache->lock)) {2195 save_errno = errno;2196 error = -1;2197}2198 packed_ref_cache->lock = NULL;2199release_packed_ref_cache(packed_ref_cache);2200 errno = save_errno;2201return error;2202}22032204/*2205 * Rollback the lockfile for the packed-refs file, and discard the2206 * in-memory packed reference cache. (The packed-refs file will be2207 * read anew if it is needed again after this function is called.)2208 */2209static voidrollback_packed_refs(struct files_ref_store *refs)2210{2211struct packed_ref_cache *packed_ref_cache =2212get_packed_ref_cache(refs);22132214assert_main_repository(&refs->base,"rollback_packed_refs");22152216if(!packed_ref_cache->lock)2217die("internal error: packed-refs not locked");2218rollback_lock_file(packed_ref_cache->lock);2219 packed_ref_cache->lock = NULL;2220release_packed_ref_cache(packed_ref_cache);2221clear_packed_ref_cache(refs);2222}22232224struct ref_to_prune {2225struct ref_to_prune *next;2226unsigned char sha1[20];2227char name[FLEX_ARRAY];2228};22292230struct pack_refs_cb_data {2231unsigned int flags;2232struct ref_dir *packed_refs;2233struct ref_to_prune *ref_to_prune;2234};22352236/*2237 * An each_ref_entry_fn that is run over loose references only. If2238 * the loose reference can be packed, add an entry in the packed ref2239 * cache. If the reference should be pruned, also add it to2240 * ref_to_prune in the pack_refs_cb_data.2241 */2242static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2243{2244struct pack_refs_cb_data *cb = cb_data;2245enum peel_status peel_status;2246struct ref_entry *packed_entry;2247int is_tag_ref =starts_with(entry->name,"refs/tags/");22482249/* Do not pack per-worktree refs: */2250if(ref_type(entry->name) != REF_TYPE_NORMAL)2251return0;22522253/* ALWAYS pack tags */2254if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2255return0;22562257/* Do not pack symbolic or broken refs: */2258if((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2259return0;22602261/* Add a packed ref cache entry equivalent to the loose entry. */2262 peel_status =peel_entry(entry,1);2263if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2264die("internal error peeling reference%s(%s)",2265 entry->name,oid_to_hex(&entry->u.value.oid));2266 packed_entry =find_ref(cb->packed_refs, entry->name);2267if(packed_entry) {2268/* Overwrite existing packed entry with info from loose entry */2269 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2270oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2271}else{2272 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2273 REF_ISPACKED | REF_KNOWS_PEELED,0);2274add_ref(cb->packed_refs, packed_entry);2275}2276oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);22772278/* Schedule the loose reference for pruning if requested. */2279if((cb->flags & PACK_REFS_PRUNE)) {2280struct ref_to_prune *n;2281FLEX_ALLOC_STR(n, name, entry->name);2282hashcpy(n->sha1, entry->u.value.oid.hash);2283 n->next = cb->ref_to_prune;2284 cb->ref_to_prune = n;2285}2286return0;2287}22882289/*2290 * Remove empty parents, but spare refs/ and immediate subdirs.2291 * Note: munges *name.2292 */2293static voidtry_remove_empty_parents(char*name)2294{2295char*p, *q;2296int i;2297 p = name;2298for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2299while(*p && *p !='/')2300 p++;2301/* tolerate duplicate slashes; see check_refname_format() */2302while(*p =='/')2303 p++;2304}2305for(q = p; *q; q++)2306;2307while(1) {2308while(q > p && *q !='/')2309 q--;2310while(q > p && *(q-1) =='/')2311 q--;2312if(q == p)2313break;2314*q ='\0';2315if(rmdir(git_path("%s", name)))2316break;2317}2318}23192320/* make sure nobody touched the ref, and unlink */2321static voidprune_ref(struct ref_to_prune *r)2322{2323struct ref_transaction *transaction;2324struct strbuf err = STRBUF_INIT;23252326if(check_refname_format(r->name,0))2327return;23282329 transaction =ref_transaction_begin(&err);2330if(!transaction ||2331ref_transaction_delete(transaction, r->name, r->sha1,2332 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2333ref_transaction_commit(transaction, &err)) {2334ref_transaction_free(transaction);2335error("%s", err.buf);2336strbuf_release(&err);2337return;2338}2339ref_transaction_free(transaction);2340strbuf_release(&err);2341try_remove_empty_parents(r->name);2342}23432344static voidprune_refs(struct ref_to_prune *r)2345{2346while(r) {2347prune_ref(r);2348 r = r->next;2349}2350}23512352static intfiles_pack_refs(struct ref_store *ref_store,unsigned int flags)2353{2354struct files_ref_store *refs =2355files_downcast(ref_store,0,"pack_refs");2356struct pack_refs_cb_data cbdata;23572358memset(&cbdata,0,sizeof(cbdata));2359 cbdata.flags = flags;23602361lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2362 cbdata.packed_refs =get_packed_refs(refs);23632364do_for_each_entry_in_dir(get_loose_refs(refs),0,2365 pack_if_possible_fn, &cbdata);23662367if(commit_packed_refs(refs))2368die_errno("unable to overwrite old ref-pack file");23692370prune_refs(cbdata.ref_to_prune);2371return0;2372}23732374/*2375 * Rewrite the packed-refs file, omitting any refs listed in2376 * 'refnames'. On error, leave packed-refs unchanged, write an error2377 * message to 'err', and return a nonzero value.2378 *2379 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2380 */2381static intrepack_without_refs(struct files_ref_store *refs,2382struct string_list *refnames,struct strbuf *err)2383{2384struct ref_dir *packed;2385struct string_list_item *refname;2386int ret, needs_repacking =0, removed =0;23872388assert_main_repository(&refs->base,"repack_without_refs");2389assert(err);23902391/* Look for a packed ref */2392for_each_string_list_item(refname, refnames) {2393if(get_packed_ref(refs, refname->string)) {2394 needs_repacking =1;2395break;2396}2397}23982399/* Avoid locking if we have nothing to do */2400if(!needs_repacking)2401return0;/* no refname exists in packed refs */24022403if(lock_packed_refs(refs,0)) {2404unable_to_lock_message(git_path("packed-refs"), errno, err);2405return-1;2406}2407 packed =get_packed_refs(refs);24082409/* Remove refnames from the cache */2410for_each_string_list_item(refname, refnames)2411if(remove_entry(packed, refname->string) != -1)2412 removed =1;2413if(!removed) {2414/*2415 * All packed entries disappeared while we were2416 * acquiring the lock.2417 */2418rollback_packed_refs(refs);2419return0;2420}24212422/* Write what remains */2423 ret =commit_packed_refs(refs);2424if(ret)2425strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2426strerror(errno));2427return ret;2428}24292430static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2431{2432assert(err);24332434if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2435/*2436 * loose. The loose file name is the same as the2437 * lockfile name, minus ".lock":2438 */2439char*loose_filename =get_locked_file_path(lock->lk);2440int res =unlink_or_msg(loose_filename, err);2441free(loose_filename);2442if(res)2443return1;2444}2445return0;2446}24472448static intfiles_delete_refs(struct ref_store *ref_store,2449struct string_list *refnames,unsigned int flags)2450{2451struct files_ref_store *refs =2452files_downcast(ref_store,0,"delete_refs");2453struct strbuf err = STRBUF_INIT;2454int i, result =0;24552456if(!refnames->nr)2457return0;24582459 result =repack_without_refs(refs, refnames, &err);2460if(result) {2461/*2462 * If we failed to rewrite the packed-refs file, then2463 * it is unsafe to try to remove loose refs, because2464 * doing so might expose an obsolete packed value for2465 * a reference that might even point at an object that2466 * has been garbage collected.2467 */2468if(refnames->nr ==1)2469error(_("could not delete reference%s:%s"),2470 refnames->items[0].string, err.buf);2471else2472error(_("could not delete references:%s"), err.buf);24732474goto out;2475}24762477for(i =0; i < refnames->nr; i++) {2478const char*refname = refnames->items[i].string;24792480if(delete_ref(refname, NULL, flags))2481 result |=error(_("could not remove reference%s"), refname);2482}24832484out:2485strbuf_release(&err);2486return result;2487}24882489/*2490 * People using contrib's git-new-workdir have .git/logs/refs ->2491 * /some/other/path/.git/logs/refs, and that may live on another device.2492 *2493 * IOW, to avoid cross device rename errors, the temporary renamed log must2494 * live into logs/refs.2495 */2496#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"24972498static intrename_tmp_log(const char*newrefname)2499{2500int attempts_remaining =4;2501struct strbuf path = STRBUF_INIT;2502int ret = -1;25032504 retry:2505strbuf_reset(&path);2506strbuf_git_path(&path,"logs/%s", newrefname);2507switch(safe_create_leading_directories_const(path.buf)) {2508case SCLD_OK:2509break;/* success */2510case SCLD_VANISHED:2511if(--attempts_remaining >0)2512goto retry;2513/* fall through */2514default:2515error("unable to create directory for%s", newrefname);2516goto out;2517}25182519if(rename(git_path(TMP_RENAMED_LOG), path.buf)) {2520if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2521/*2522 * rename(a, b) when b is an existing2523 * directory ought to result in ISDIR, but2524 * Solaris 5.8 gives ENOTDIR. Sheesh.2525 */2526if(remove_empty_directories(&path)) {2527error("Directory not empty: logs/%s", newrefname);2528goto out;2529}2530goto retry;2531}else if(errno == ENOENT && --attempts_remaining >0) {2532/*2533 * Maybe another process just deleted one of2534 * the directories in the path to newrefname.2535 * Try again from the beginning.2536 */2537goto retry;2538}else{2539error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2540 newrefname,strerror(errno));2541goto out;2542}2543}2544 ret =0;2545out:2546strbuf_release(&path);2547return ret;2548}25492550static intfiles_verify_refname_available(struct ref_store *ref_store,2551const char*newname,2552const struct string_list *extras,2553const struct string_list *skip,2554struct strbuf *err)2555{2556struct files_ref_store *refs =2557files_downcast(ref_store,1,"verify_refname_available");2558struct ref_dir *packed_refs =get_packed_refs(refs);2559struct ref_dir *loose_refs =get_loose_refs(refs);25602561if(verify_refname_available_dir(newname, extras, skip,2562 packed_refs, err) ||2563verify_refname_available_dir(newname, extras, skip,2564 loose_refs, err))2565return-1;25662567return0;2568}25692570static intwrite_ref_to_lockfile(struct ref_lock *lock,2571const unsigned char*sha1,struct strbuf *err);2572static intcommit_ref_update(struct files_ref_store *refs,2573struct ref_lock *lock,2574const unsigned char*sha1,const char*logmsg,2575struct strbuf *err);25762577static intfiles_rename_ref(struct ref_store *ref_store,2578const char*oldrefname,const char*newrefname,2579const char*logmsg)2580{2581struct files_ref_store *refs =2582files_downcast(ref_store,0,"rename_ref");2583unsigned char sha1[20], orig_sha1[20];2584int flag =0, logmoved =0;2585struct ref_lock *lock;2586struct stat loginfo;2587int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2588struct strbuf err = STRBUF_INIT;25892590if(log &&S_ISLNK(loginfo.st_mode))2591returnerror("reflog for%sis a symlink", oldrefname);25922593if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2594 orig_sha1, &flag))2595returnerror("refname%snot found", oldrefname);25962597if(flag & REF_ISSYMREF)2598returnerror("refname%sis a symbolic ref, renaming it is not supported",2599 oldrefname);2600if(!rename_ref_available(oldrefname, newrefname))2601return1;26022603if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2604returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2605 oldrefname,strerror(errno));26062607if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2608error("unable to delete old%s", oldrefname);2609goto rollback;2610}26112612/*2613 * Since we are doing a shallow lookup, sha1 is not the2614 * correct value to pass to delete_ref as old_sha1. But that2615 * doesn't matter, because an old_sha1 check wouldn't add to2616 * the safety anyway; we want to delete the reference whatever2617 * its current value.2618 */2619if(!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2620 sha1, NULL) &&2621delete_ref(newrefname, NULL, REF_NODEREF)) {2622if(errno==EISDIR) {2623struct strbuf path = STRBUF_INIT;2624int result;26252626strbuf_git_path(&path,"%s", newrefname);2627 result =remove_empty_directories(&path);2628strbuf_release(&path);26292630if(result) {2631error("Directory not empty:%s", newrefname);2632goto rollback;2633}2634}else{2635error("unable to delete existing%s", newrefname);2636goto rollback;2637}2638}26392640if(log &&rename_tmp_log(newrefname))2641goto rollback;26422643 logmoved = log;26442645 lock =lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,2646 REF_NODEREF, NULL, &err);2647if(!lock) {2648error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2649strbuf_release(&err);2650goto rollback;2651}2652hashcpy(lock->old_oid.hash, orig_sha1);26532654if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2655commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {2656error("unable to write current sha1 into%s:%s", newrefname, err.buf);2657strbuf_release(&err);2658goto rollback;2659}26602661return0;26622663 rollback:2664 lock =lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,2665 REF_NODEREF, NULL, &err);2666if(!lock) {2667error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2668strbuf_release(&err);2669goto rollbacklog;2670}26712672 flag = log_all_ref_updates;2673 log_all_ref_updates =0;2674if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2675commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {2676error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2677strbuf_release(&err);2678}2679 log_all_ref_updates = flag;26802681 rollbacklog:2682if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2683error("unable to restore logfile%sfrom%s:%s",2684 oldrefname, newrefname,strerror(errno));2685if(!logmoved && log &&2686rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2687error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2688 oldrefname,strerror(errno));26892690return1;2691}26922693static intclose_ref(struct ref_lock *lock)2694{2695if(close_lock_file(lock->lk))2696return-1;2697return0;2698}26992700static intcommit_ref(struct ref_lock *lock)2701{2702char*path =get_locked_file_path(lock->lk);2703struct stat st;27042705if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2706/*2707 * There is a directory at the path we want to rename2708 * the lockfile to. Hopefully it is empty; try to2709 * delete it.2710 */2711size_t len =strlen(path);2712struct strbuf sb_path = STRBUF_INIT;27132714strbuf_attach(&sb_path, path, len, len);27152716/*2717 * If this fails, commit_lock_file() will also fail2718 * and will report the problem.2719 */2720remove_empty_directories(&sb_path);2721strbuf_release(&sb_path);2722}else{2723free(path);2724}27252726if(commit_lock_file(lock->lk))2727return-1;2728return0;2729}27302731/*2732 * Create a reflog for a ref. If force_create = 0, the reflog will2733 * only be created for certain refs (those for which2734 * should_autocreate_reflog returns non-zero. Otherwise, create it2735 * regardless of the ref name. Fill in *err and return -1 on failure.2736 */2737static intlog_ref_setup(const char*refname,struct strbuf *logfile,struct strbuf *err,int force_create)2738{2739int logfd, oflags = O_APPEND | O_WRONLY;27402741strbuf_git_path(logfile,"logs/%s", refname);2742if(force_create ||should_autocreate_reflog(refname)) {2743if(safe_create_leading_directories(logfile->buf) <0) {2744strbuf_addf(err,"unable to create directory for '%s': "2745"%s", logfile->buf,strerror(errno));2746return-1;2747}2748 oflags |= O_CREAT;2749}27502751 logfd =open(logfile->buf, oflags,0666);2752if(logfd <0) {2753if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2754return0;27552756if(errno == EISDIR) {2757if(remove_empty_directories(logfile)) {2758strbuf_addf(err,"there are still logs under "2759"'%s'", logfile->buf);2760return-1;2761}2762 logfd =open(logfile->buf, oflags,0666);2763}27642765if(logfd <0) {2766strbuf_addf(err,"unable to append to '%s':%s",2767 logfile->buf,strerror(errno));2768return-1;2769}2770}27712772adjust_shared_perm(logfile->buf);2773close(logfd);2774return0;2775}277627772778static intfiles_create_reflog(struct ref_store *ref_store,2779const char*refname,int force_create,2780struct strbuf *err)2781{2782int ret;2783struct strbuf sb = STRBUF_INIT;27842785/* Check validity (but we don't need the result): */2786files_downcast(ref_store,0,"create_reflog");27872788 ret =log_ref_setup(refname, &sb, err, force_create);2789strbuf_release(&sb);2790return ret;2791}27922793static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2794const unsigned char*new_sha1,2795const char*committer,const char*msg)2796{2797int msglen, written;2798unsigned maxlen, len;2799char*logrec;28002801 msglen = msg ?strlen(msg) :0;2802 maxlen =strlen(committer) + msglen +100;2803 logrec =xmalloc(maxlen);2804 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2805sha1_to_hex(old_sha1),2806sha1_to_hex(new_sha1),2807 committer);2808if(msglen)2809 len +=copy_reflog_msg(logrec + len -1, msg) -1;28102811 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2812free(logrec);2813if(written != len)2814return-1;28152816return0;2817}28182819static intlog_ref_write_1(const char*refname,const unsigned char*old_sha1,2820const unsigned char*new_sha1,const char*msg,2821struct strbuf *logfile,int flags,2822struct strbuf *err)2823{2824int logfd, result, oflags = O_APPEND | O_WRONLY;28252826if(log_all_ref_updates <0)2827 log_all_ref_updates = !is_bare_repository();28282829 result =log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);28302831if(result)2832return result;28332834 logfd =open(logfile->buf, oflags);2835if(logfd <0)2836return0;2837 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2838git_committer_info(0), msg);2839if(result) {2840strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2841strerror(errno));2842close(logfd);2843return-1;2844}2845if(close(logfd)) {2846strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2847strerror(errno));2848return-1;2849}2850return0;2851}28522853static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2854const unsigned char*new_sha1,const char*msg,2855int flags,struct strbuf *err)2856{2857returnfiles_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2858 err);2859}28602861intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1,2862const unsigned char*new_sha1,const char*msg,2863int flags,struct strbuf *err)2864{2865struct strbuf sb = STRBUF_INIT;2866int ret =log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2867 err);2868strbuf_release(&sb);2869return ret;2870}28712872/*2873 * Write sha1 into the open lockfile, then close the lockfile. On2874 * errors, rollback the lockfile, fill in *err and2875 * return -1.2876 */2877static intwrite_ref_to_lockfile(struct ref_lock *lock,2878const unsigned char*sha1,struct strbuf *err)2879{2880static char term ='\n';2881struct object *o;2882int fd;28832884 o =parse_object(sha1);2885if(!o) {2886strbuf_addf(err,2887"trying to write ref '%s' with nonexistent object%s",2888 lock->ref_name,sha1_to_hex(sha1));2889unlock_ref(lock);2890return-1;2891}2892if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2893strbuf_addf(err,2894"trying to write non-commit object%sto branch '%s'",2895sha1_to_hex(sha1), lock->ref_name);2896unlock_ref(lock);2897return-1;2898}2899 fd =get_lock_file_fd(lock->lk);2900if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2901write_in_full(fd, &term,1) !=1||2902close_ref(lock) <0) {2903strbuf_addf(err,2904"couldn't write '%s'",get_lock_file_path(lock->lk));2905unlock_ref(lock);2906return-1;2907}2908return0;2909}29102911/*2912 * Commit a change to a loose reference that has already been written2913 * to the loose reference lockfile. Also update the reflogs if2914 * necessary, using the specified lockmsg (which can be NULL).2915 */2916static intcommit_ref_update(struct files_ref_store *refs,2917struct ref_lock *lock,2918const unsigned char*sha1,const char*logmsg,2919struct strbuf *err)2920{2921assert_main_repository(&refs->base,"commit_ref_update");29222923clear_loose_ref_cache(refs);2924if(log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg,0, err)) {2925char*old_msg =strbuf_detach(err, NULL);2926strbuf_addf(err,"cannot update the ref '%s':%s",2927 lock->ref_name, old_msg);2928free(old_msg);2929unlock_ref(lock);2930return-1;2931}29322933if(strcmp(lock->ref_name,"HEAD") !=0) {2934/*2935 * Special hack: If a branch is updated directly and HEAD2936 * points to it (may happen on the remote side of a push2937 * for example) then logically the HEAD reflog should be2938 * updated too.2939 * A generic solution implies reverse symref information,2940 * but finding all symrefs pointing to the given branch2941 * would be rather costly for this rare event (the direct2942 * update of a branch) to be worth it. So let's cheat and2943 * check with HEAD only which should cover 99% of all usage2944 * scenarios (even 100% of the default ones).2945 */2946unsigned char head_sha1[20];2947int head_flag;2948const char*head_ref;29492950 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2951 head_sha1, &head_flag);2952if(head_ref && (head_flag & REF_ISSYMREF) &&2953!strcmp(head_ref, lock->ref_name)) {2954struct strbuf log_err = STRBUF_INIT;2955if(log_ref_write("HEAD", lock->old_oid.hash, sha1,2956 logmsg,0, &log_err)) {2957error("%s", log_err.buf);2958strbuf_release(&log_err);2959}2960}2961}29622963if(commit_ref(lock)) {2964strbuf_addf(err,"couldn't set '%s'", lock->ref_name);2965unlock_ref(lock);2966return-1;2967}29682969unlock_ref(lock);2970return0;2971}29722973static intcreate_ref_symlink(struct ref_lock *lock,const char*target)2974{2975int ret = -1;2976#ifndef NO_SYMLINK_HEAD2977char*ref_path =get_locked_file_path(lock->lk);2978unlink(ref_path);2979 ret =symlink(target, ref_path);2980free(ref_path);29812982if(ret)2983fprintf(stderr,"no symlink - falling back to symbolic ref\n");2984#endif2985return ret;2986}29872988static voidupdate_symref_reflog(struct ref_lock *lock,const char*refname,2989const char*target,const char*logmsg)2990{2991struct strbuf err = STRBUF_INIT;2992unsigned char new_sha1[20];2993if(logmsg && !read_ref(target, new_sha1) &&2994log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg,0, &err)) {2995error("%s", err.buf);2996strbuf_release(&err);2997}2998}29993000static intcreate_symref_locked(struct ref_lock *lock,const char*refname,3001const char*target,const char*logmsg)3002{3003if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {3004update_symref_reflog(lock, refname, target, logmsg);3005return0;3006}30073008if(!fdopen_lock_file(lock->lk,"w"))3009returnerror("unable to fdopen%s:%s",3010 lock->lk->tempfile.filename.buf,strerror(errno));30113012update_symref_reflog(lock, refname, target, logmsg);30133014/* no error check; commit_ref will check ferror */3015fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);3016if(commit_ref(lock) <0)3017returnerror("unable to write symref for%s:%s", refname,3018strerror(errno));3019return0;3020}30213022static intfiles_create_symref(struct ref_store *ref_store,3023const char*refname,const char*target,3024const char*logmsg)3025{3026struct files_ref_store *refs =3027files_downcast(ref_store,0,"create_symref");3028struct strbuf err = STRBUF_INIT;3029struct ref_lock *lock;3030int ret;30313032 lock =lock_ref_sha1_basic(refs, refname, NULL,3033 NULL, NULL, REF_NODEREF, NULL,3034&err);3035if(!lock) {3036error("%s", err.buf);3037strbuf_release(&err);3038return-1;3039}30403041 ret =create_symref_locked(lock, refname, target, logmsg);3042unlock_ref(lock);3043return ret;3044}30453046intset_worktree_head_symref(const char*gitdir,const char*target)3047{3048static struct lock_file head_lock;3049struct ref_lock *lock;3050struct strbuf head_path = STRBUF_INIT;3051const char*head_rel;3052int ret;30533054strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));3055if(hold_lock_file_for_update(&head_lock, head_path.buf,3056 LOCK_NO_DEREF) <0) {3057struct strbuf err = STRBUF_INIT;3058unable_to_lock_message(head_path.buf, errno, &err);3059error("%s", err.buf);3060strbuf_release(&err);3061strbuf_release(&head_path);3062return-1;3063}30643065/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3066 linked trees */3067 head_rel =remove_leading_path(head_path.buf,3068absolute_path(get_git_common_dir()));3069/* to make use of create_symref_locked(), initialize ref_lock */3070 lock =xcalloc(1,sizeof(struct ref_lock));3071 lock->lk = &head_lock;3072 lock->ref_name =xstrdup(head_rel);30733074 ret =create_symref_locked(lock, head_rel, target, NULL);30753076unlock_ref(lock);/* will free lock */3077strbuf_release(&head_path);3078return ret;3079}30803081static intfiles_reflog_exists(struct ref_store *ref_store,3082const char*refname)3083{3084struct stat st;30853086/* Check validity (but we don't need the result): */3087files_downcast(ref_store,0,"reflog_exists");30883089return!lstat(git_path("logs/%s", refname), &st) &&3090S_ISREG(st.st_mode);3091}30923093static intfiles_delete_reflog(struct ref_store *ref_store,3094const char*refname)3095{3096/* Check validity (but we don't need the result): */3097files_downcast(ref_store,0,"delete_reflog");30983099returnremove_path(git_path("logs/%s", refname));3100}31013102static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3103{3104unsigned char osha1[20], nsha1[20];3105char*email_end, *message;3106unsigned long timestamp;3107int tz;31083109/* old SP new SP name <email> SP time TAB msg LF */3110if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3111get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3112get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3113!(email_end =strchr(sb->buf +82,'>')) ||3114 email_end[1] !=' '||3115!(timestamp =strtoul(email_end +2, &message,10)) ||3116!message || message[0] !=' '||3117(message[1] !='+'&& message[1] !='-') ||3118!isdigit(message[2]) || !isdigit(message[3]) ||3119!isdigit(message[4]) || !isdigit(message[5]))3120return0;/* corrupt? */3121 email_end[1] ='\0';3122 tz =strtol(message +1, NULL,10);3123if(message[6] !='\t')3124 message +=6;3125else3126 message +=7;3127returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3128}31293130static char*find_beginning_of_line(char*bob,char*scan)3131{3132while(bob < scan && *(--scan) !='\n')3133;/* keep scanning backwards */3134/*3135 * Return either beginning of the buffer, or LF at the end of3136 * the previous line.3137 */3138return scan;3139}31403141static intfiles_for_each_reflog_ent_reverse(struct ref_store *ref_store,3142const char*refname,3143 each_reflog_ent_fn fn,3144void*cb_data)3145{3146struct strbuf sb = STRBUF_INIT;3147FILE*logfp;3148long pos;3149int ret =0, at_tail =1;31503151/* Check validity (but we don't need the result): */3152files_downcast(ref_store,0,"for_each_reflog_ent_reverse");31533154 logfp =fopen(git_path("logs/%s", refname),"r");3155if(!logfp)3156return-1;31573158/* Jump to the end */3159if(fseek(logfp,0, SEEK_END) <0)3160returnerror("cannot seek back reflog for%s:%s",3161 refname,strerror(errno));3162 pos =ftell(logfp);3163while(!ret &&0< pos) {3164int cnt;3165size_t nread;3166char buf[BUFSIZ];3167char*endp, *scanp;31683169/* Fill next block from the end */3170 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3171if(fseek(logfp, pos - cnt, SEEK_SET))3172returnerror("cannot seek back reflog for%s:%s",3173 refname,strerror(errno));3174 nread =fread(buf, cnt,1, logfp);3175if(nread !=1)3176returnerror("cannot read%dbytes from reflog for%s:%s",3177 cnt, refname,strerror(errno));3178 pos -= cnt;31793180 scanp = endp = buf + cnt;3181if(at_tail && scanp[-1] =='\n')3182/* Looking at the final LF at the end of the file */3183 scanp--;3184 at_tail =0;31853186while(buf < scanp) {3187/*3188 * terminating LF of the previous line, or the beginning3189 * of the buffer.3190 */3191char*bp;31923193 bp =find_beginning_of_line(buf, scanp);31943195if(*bp =='\n') {3196/*3197 * The newline is the end of the previous line,3198 * so we know we have complete line starting3199 * at (bp + 1). Prefix it onto any prior data3200 * we collected for the line and process it.3201 */3202strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3203 scanp = bp;3204 endp = bp +1;3205 ret =show_one_reflog_ent(&sb, fn, cb_data);3206strbuf_reset(&sb);3207if(ret)3208break;3209}else if(!pos) {3210/*3211 * We are at the start of the buffer, and the3212 * start of the file; there is no previous3213 * line, and we have everything for this one.3214 * Process it, and we can end the loop.3215 */3216strbuf_splice(&sb,0,0, buf, endp - buf);3217 ret =show_one_reflog_ent(&sb, fn, cb_data);3218strbuf_reset(&sb);3219break;3220}32213222if(bp == buf) {3223/*3224 * We are at the start of the buffer, and there3225 * is more file to read backwards. Which means3226 * we are in the middle of a line. Note that we3227 * may get here even if *bp was a newline; that3228 * just means we are at the exact end of the3229 * previous line, rather than some spot in the3230 * middle.3231 *3232 * Save away what we have to be combined with3233 * the data from the next read.3234 */3235strbuf_splice(&sb,0,0, buf, endp - buf);3236break;3237}3238}32393240}3241if(!ret && sb.len)3242die("BUG: reverse reflog parser had leftover data");32433244fclose(logfp);3245strbuf_release(&sb);3246return ret;3247}32483249static intfiles_for_each_reflog_ent(struct ref_store *ref_store,3250const char*refname,3251 each_reflog_ent_fn fn,void*cb_data)3252{3253FILE*logfp;3254struct strbuf sb = STRBUF_INIT;3255int ret =0;32563257/* Check validity (but we don't need the result): */3258files_downcast(ref_store,0,"for_each_reflog_ent");32593260 logfp =fopen(git_path("logs/%s", refname),"r");3261if(!logfp)3262return-1;32633264while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3265 ret =show_one_reflog_ent(&sb, fn, cb_data);3266fclose(logfp);3267strbuf_release(&sb);3268return ret;3269}32703271struct files_reflog_iterator {3272struct ref_iterator base;32733274struct dir_iterator *dir_iterator;3275struct object_id oid;3276};32773278static intfiles_reflog_iterator_advance(struct ref_iterator *ref_iterator)3279{3280struct files_reflog_iterator *iter =3281(struct files_reflog_iterator *)ref_iterator;3282struct dir_iterator *diter = iter->dir_iterator;3283int ok;32843285while((ok =dir_iterator_advance(diter)) == ITER_OK) {3286int flags;32873288if(!S_ISREG(diter->st.st_mode))3289continue;3290if(diter->basename[0] =='.')3291continue;3292if(ends_with(diter->basename,".lock"))3293continue;32943295if(read_ref_full(diter->relative_path,0,3296 iter->oid.hash, &flags)) {3297error("bad ref for%s", diter->path.buf);3298continue;3299}33003301 iter->base.refname = diter->relative_path;3302 iter->base.oid = &iter->oid;3303 iter->base.flags = flags;3304return ITER_OK;3305}33063307 iter->dir_iterator = NULL;3308if(ref_iterator_abort(ref_iterator) == ITER_ERROR)3309 ok = ITER_ERROR;3310return ok;3311}33123313static intfiles_reflog_iterator_peel(struct ref_iterator *ref_iterator,3314struct object_id *peeled)3315{3316die("BUG: ref_iterator_peel() called for reflog_iterator");3317}33183319static intfiles_reflog_iterator_abort(struct ref_iterator *ref_iterator)3320{3321struct files_reflog_iterator *iter =3322(struct files_reflog_iterator *)ref_iterator;3323int ok = ITER_DONE;33243325if(iter->dir_iterator)3326 ok =dir_iterator_abort(iter->dir_iterator);33273328base_ref_iterator_free(ref_iterator);3329return ok;3330}33313332static struct ref_iterator_vtable files_reflog_iterator_vtable = {3333 files_reflog_iterator_advance,3334 files_reflog_iterator_peel,3335 files_reflog_iterator_abort3336};33373338static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)3339{3340struct files_reflog_iterator *iter =xcalloc(1,sizeof(*iter));3341struct ref_iterator *ref_iterator = &iter->base;33423343/* Check validity (but we don't need the result): */3344files_downcast(ref_store,0,"reflog_iterator_begin");33453346base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3347 iter->dir_iterator =dir_iterator_begin(git_path("logs"));3348return ref_iterator;3349}33503351static intref_update_reject_duplicates(struct string_list *refnames,3352struct strbuf *err)3353{3354int i, n = refnames->nr;33553356assert(err);33573358for(i =1; i < n; i++)3359if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3360strbuf_addf(err,3361"multiple updates for ref '%s' not allowed.",3362 refnames->items[i].string);3363return1;3364}3365return0;3366}33673368/*3369 * If update is a direct update of head_ref (the reference pointed to3370 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3371 */3372static intsplit_head_update(struct ref_update *update,3373struct ref_transaction *transaction,3374const char*head_ref,3375struct string_list *affected_refnames,3376struct strbuf *err)3377{3378struct string_list_item *item;3379struct ref_update *new_update;33803381if((update->flags & REF_LOG_ONLY) ||3382(update->flags & REF_ISPRUNING) ||3383(update->flags & REF_UPDATE_VIA_HEAD))3384return0;33853386if(strcmp(update->refname, head_ref))3387return0;33883389/*3390 * First make sure that HEAD is not already in the3391 * transaction. This insertion is O(N) in the transaction3392 * size, but it happens at most once per transaction.3393 */3394 item =string_list_insert(affected_refnames,"HEAD");3395if(item->util) {3396/* An entry already existed */3397strbuf_addf(err,3398"multiple updates for 'HEAD' (including one "3399"via its referent '%s') are not allowed",3400 update->refname);3401return TRANSACTION_NAME_CONFLICT;3402}34033404 new_update =ref_transaction_add_update(3405 transaction,"HEAD",3406 update->flags | REF_LOG_ONLY | REF_NODEREF,3407 update->new_sha1, update->old_sha1,3408 update->msg);34093410 item->util = new_update;34113412return0;3413}34143415/*3416 * update is for a symref that points at referent and doesn't have3417 * REF_NODEREF set. Split it into two updates:3418 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3419 * - A new, separate update for the referent reference3420 * Note that the new update will itself be subject to splitting when3421 * the iteration gets to it.3422 */3423static intsplit_symref_update(struct files_ref_store *refs,3424struct ref_update *update,3425const char*referent,3426struct ref_transaction *transaction,3427struct string_list *affected_refnames,3428struct strbuf *err)3429{3430struct string_list_item *item;3431struct ref_update *new_update;3432unsigned int new_flags;34333434/*3435 * First make sure that referent is not already in the3436 * transaction. This insertion is O(N) in the transaction3437 * size, but it happens at most once per symref in a3438 * transaction.3439 */3440 item =string_list_insert(affected_refnames, referent);3441if(item->util) {3442/* An entry already existed */3443strbuf_addf(err,3444"multiple updates for '%s' (including one "3445"via symref '%s') are not allowed",3446 referent, update->refname);3447return TRANSACTION_NAME_CONFLICT;3448}34493450 new_flags = update->flags;3451if(!strcmp(update->refname,"HEAD")) {3452/*3453 * Record that the new update came via HEAD, so that3454 * when we process it, split_head_update() doesn't try3455 * to add another reflog update for HEAD. Note that3456 * this bit will be propagated if the new_update3457 * itself needs to be split.3458 */3459 new_flags |= REF_UPDATE_VIA_HEAD;3460}34613462 new_update =ref_transaction_add_update(3463 transaction, referent, new_flags,3464 update->new_sha1, update->old_sha1,3465 update->msg);34663467 new_update->parent_update = update;34683469/*3470 * Change the symbolic ref update to log only. Also, it3471 * doesn't need to check its old SHA-1 value, as that will be3472 * done when new_update is processed.3473 */3474 update->flags |= REF_LOG_ONLY | REF_NODEREF;3475 update->flags &= ~REF_HAVE_OLD;34763477 item->util = new_update;34783479return0;3480}34813482/*3483 * Return the refname under which update was originally requested.3484 */3485static const char*original_update_refname(struct ref_update *update)3486{3487while(update->parent_update)3488 update = update->parent_update;34893490return update->refname;3491}34923493/*3494 * Check whether the REF_HAVE_OLD and old_oid values stored in update3495 * are consistent with oid, which is the reference's current value. If3496 * everything is OK, return 0; otherwise, write an error message to3497 * err and return -1.3498 */3499static intcheck_old_oid(struct ref_update *update,struct object_id *oid,3500struct strbuf *err)3501{3502if(!(update->flags & REF_HAVE_OLD) ||3503!hashcmp(oid->hash, update->old_sha1))3504return0;35053506if(is_null_sha1(update->old_sha1))3507strbuf_addf(err,"cannot lock ref '%s': "3508"reference already exists",3509original_update_refname(update));3510else if(is_null_oid(oid))3511strbuf_addf(err,"cannot lock ref '%s': "3512"reference is missing but expected%s",3513original_update_refname(update),3514sha1_to_hex(update->old_sha1));3515else3516strbuf_addf(err,"cannot lock ref '%s': "3517"is at%sbut expected%s",3518original_update_refname(update),3519oid_to_hex(oid),3520sha1_to_hex(update->old_sha1));35213522return-1;3523}35243525/*3526 * Prepare for carrying out update:3527 * - Lock the reference referred to by update.3528 * - Read the reference under lock.3529 * - Check that its old SHA-1 value (if specified) is correct, and in3530 * any case record it in update->lock->old_oid for later use when3531 * writing the reflog.3532 * - If it is a symref update without REF_NODEREF, split it up into a3533 * REF_LOG_ONLY update of the symref and add a separate update for3534 * the referent to transaction.3535 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3536 * update of HEAD.3537 */3538static intlock_ref_for_update(struct files_ref_store *refs,3539struct ref_update *update,3540struct ref_transaction *transaction,3541const char*head_ref,3542struct string_list *affected_refnames,3543struct strbuf *err)3544{3545struct strbuf referent = STRBUF_INIT;3546int mustexist = (update->flags & REF_HAVE_OLD) &&3547!is_null_sha1(update->old_sha1);3548int ret;3549struct ref_lock *lock;35503551assert_main_repository(&refs->base,"lock_ref_for_update");35523553if((update->flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3554 update->flags |= REF_DELETING;35553556if(head_ref) {3557 ret =split_head_update(update, transaction, head_ref,3558 affected_refnames, err);3559if(ret)3560return ret;3561}35623563 ret =lock_raw_ref(refs, update->refname, mustexist,3564 affected_refnames, NULL,3565&lock, &referent,3566&update->type, err);3567if(ret) {3568char*reason;35693570 reason =strbuf_detach(err, NULL);3571strbuf_addf(err,"cannot lock ref '%s':%s",3572original_update_refname(update), reason);3573free(reason);3574return ret;3575}35763577 update->backend_data = lock;35783579if(update->type & REF_ISSYMREF) {3580if(update->flags & REF_NODEREF) {3581/*3582 * We won't be reading the referent as part of3583 * the transaction, so we have to read it here3584 * to record and possibly check old_sha1:3585 */3586if(read_ref_full(referent.buf,0,3587 lock->old_oid.hash, NULL)) {3588if(update->flags & REF_HAVE_OLD) {3589strbuf_addf(err,"cannot lock ref '%s': "3590"error reading reference",3591original_update_refname(update));3592return-1;3593}3594}else if(check_old_oid(update, &lock->old_oid, err)) {3595return TRANSACTION_GENERIC_ERROR;3596}3597}else{3598/*3599 * Create a new update for the reference this3600 * symref is pointing at. Also, we will record3601 * and verify old_sha1 for this update as part3602 * of processing the split-off update, so we3603 * don't have to do it here.3604 */3605 ret =split_symref_update(refs, update,3606 referent.buf, transaction,3607 affected_refnames, err);3608if(ret)3609return ret;3610}3611}else{3612struct ref_update *parent_update;36133614if(check_old_oid(update, &lock->old_oid, err))3615return TRANSACTION_GENERIC_ERROR;36163617/*3618 * If this update is happening indirectly because of a3619 * symref update, record the old SHA-1 in the parent3620 * update:3621 */3622for(parent_update = update->parent_update;3623 parent_update;3624 parent_update = parent_update->parent_update) {3625struct ref_lock *parent_lock = parent_update->backend_data;3626oidcpy(&parent_lock->old_oid, &lock->old_oid);3627}3628}36293630if((update->flags & REF_HAVE_NEW) &&3631!(update->flags & REF_DELETING) &&3632!(update->flags & REF_LOG_ONLY)) {3633if(!(update->type & REF_ISSYMREF) &&3634!hashcmp(lock->old_oid.hash, update->new_sha1)) {3635/*3636 * The reference already has the desired3637 * value, so we don't need to write it.3638 */3639}else if(write_ref_to_lockfile(lock, update->new_sha1,3640 err)) {3641char*write_err =strbuf_detach(err, NULL);36423643/*3644 * The lock was freed upon failure of3645 * write_ref_to_lockfile():3646 */3647 update->backend_data = NULL;3648strbuf_addf(err,3649"cannot update ref '%s':%s",3650 update->refname, write_err);3651free(write_err);3652return TRANSACTION_GENERIC_ERROR;3653}else{3654 update->flags |= REF_NEEDS_COMMIT;3655}3656}3657if(!(update->flags & REF_NEEDS_COMMIT)) {3658/*3659 * We didn't call write_ref_to_lockfile(), so3660 * the lockfile is still open. Close it to3661 * free up the file descriptor:3662 */3663if(close_ref(lock)) {3664strbuf_addf(err,"couldn't close '%s.lock'",3665 update->refname);3666return TRANSACTION_GENERIC_ERROR;3667}3668}3669return0;3670}36713672static intfiles_transaction_commit(struct ref_store *ref_store,3673struct ref_transaction *transaction,3674struct strbuf *err)3675{3676struct files_ref_store *refs =3677files_downcast(ref_store,0,"ref_transaction_commit");3678int ret =0, i;3679struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3680struct string_list_item *ref_to_delete;3681struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3682char*head_ref = NULL;3683int head_type;3684struct object_id head_oid;36853686assert(err);36873688if(transaction->state != REF_TRANSACTION_OPEN)3689die("BUG: commit called for transaction that is not open");36903691if(!transaction->nr) {3692 transaction->state = REF_TRANSACTION_CLOSED;3693return0;3694}36953696/*3697 * Fail if a refname appears more than once in the3698 * transaction. (If we end up splitting up any updates using3699 * split_symref_update() or split_head_update(), those3700 * functions will check that the new updates don't have the3701 * same refname as any existing ones.)3702 */3703for(i =0; i < transaction->nr; i++) {3704struct ref_update *update = transaction->updates[i];3705struct string_list_item *item =3706string_list_append(&affected_refnames, update->refname);37073708/*3709 * We store a pointer to update in item->util, but at3710 * the moment we never use the value of this field3711 * except to check whether it is non-NULL.3712 */3713 item->util = update;3714}3715string_list_sort(&affected_refnames);3716if(ref_update_reject_duplicates(&affected_refnames, err)) {3717 ret = TRANSACTION_GENERIC_ERROR;3718goto cleanup;3719}37203721/*3722 * Special hack: If a branch is updated directly and HEAD3723 * points to it (may happen on the remote side of a push3724 * for example) then logically the HEAD reflog should be3725 * updated too.3726 *3727 * A generic solution would require reverse symref lookups,3728 * but finding all symrefs pointing to a given branch would be3729 * rather costly for this rare event (the direct update of a3730 * branch) to be worth it. So let's cheat and check with HEAD3731 * only, which should cover 99% of all usage scenarios (even3732 * 100% of the default ones).3733 *3734 * So if HEAD is a symbolic reference, then record the name of3735 * the reference that it points to. If we see an update of3736 * head_ref within the transaction, then split_head_update()3737 * arranges for the reflog of HEAD to be updated, too.3738 */3739 head_ref =resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3740 head_oid.hash, &head_type);37413742if(head_ref && !(head_type & REF_ISSYMREF)) {3743free(head_ref);3744 head_ref = NULL;3745}37463747/*3748 * Acquire all locks, verify old values if provided, check3749 * that new values are valid, and write new values to the3750 * lockfiles, ready to be activated. Only keep one lockfile3751 * open at a time to avoid running out of file descriptors.3752 */3753for(i =0; i < transaction->nr; i++) {3754struct ref_update *update = transaction->updates[i];37553756 ret =lock_ref_for_update(refs, update, transaction,3757 head_ref, &affected_refnames, err);3758if(ret)3759goto cleanup;3760}37613762/* Perform updates first so live commits remain referenced */3763for(i =0; i < transaction->nr; i++) {3764struct ref_update *update = transaction->updates[i];3765struct ref_lock *lock = update->backend_data;37663767if(update->flags & REF_NEEDS_COMMIT ||3768 update->flags & REF_LOG_ONLY) {3769if(log_ref_write(lock->ref_name, lock->old_oid.hash,3770 update->new_sha1,3771 update->msg, update->flags, err)) {3772char*old_msg =strbuf_detach(err, NULL);37733774strbuf_addf(err,"cannot update the ref '%s':%s",3775 lock->ref_name, old_msg);3776free(old_msg);3777unlock_ref(lock);3778 update->backend_data = NULL;3779 ret = TRANSACTION_GENERIC_ERROR;3780goto cleanup;3781}3782}3783if(update->flags & REF_NEEDS_COMMIT) {3784clear_loose_ref_cache(refs);3785if(commit_ref(lock)) {3786strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3787unlock_ref(lock);3788 update->backend_data = NULL;3789 ret = TRANSACTION_GENERIC_ERROR;3790goto cleanup;3791}3792}3793}3794/* Perform deletes now that updates are safely completed */3795for(i =0; i < transaction->nr; i++) {3796struct ref_update *update = transaction->updates[i];3797struct ref_lock *lock = update->backend_data;37983799if(update->flags & REF_DELETING &&3800!(update->flags & REF_LOG_ONLY)) {3801if(delete_ref_loose(lock, update->type, err)) {3802 ret = TRANSACTION_GENERIC_ERROR;3803goto cleanup;3804}38053806if(!(update->flags & REF_ISPRUNING))3807string_list_append(&refs_to_delete,3808 lock->ref_name);3809}3810}38113812if(repack_without_refs(refs, &refs_to_delete, err)) {3813 ret = TRANSACTION_GENERIC_ERROR;3814goto cleanup;3815}3816for_each_string_list_item(ref_to_delete, &refs_to_delete)3817unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3818clear_loose_ref_cache(refs);38193820cleanup:3821 transaction->state = REF_TRANSACTION_CLOSED;38223823for(i =0; i < transaction->nr; i++)3824if(transaction->updates[i]->backend_data)3825unlock_ref(transaction->updates[i]->backend_data);3826string_list_clear(&refs_to_delete,0);3827free(head_ref);3828string_list_clear(&affected_refnames,0);38293830return ret;3831}38323833static intref_present(const char*refname,3834const struct object_id *oid,int flags,void*cb_data)3835{3836struct string_list *affected_refnames = cb_data;38373838returnstring_list_has_string(affected_refnames, refname);3839}38403841static intfiles_initial_transaction_commit(struct ref_store *ref_store,3842struct ref_transaction *transaction,3843struct strbuf *err)3844{3845struct files_ref_store *refs =3846files_downcast(ref_store,0,"initial_ref_transaction_commit");3847int ret =0, i;3848struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38493850assert(err);38513852if(transaction->state != REF_TRANSACTION_OPEN)3853die("BUG: commit called for transaction that is not open");38543855/* Fail if a refname appears more than once in the transaction: */3856for(i =0; i < transaction->nr; i++)3857string_list_append(&affected_refnames,3858 transaction->updates[i]->refname);3859string_list_sort(&affected_refnames);3860if(ref_update_reject_duplicates(&affected_refnames, err)) {3861 ret = TRANSACTION_GENERIC_ERROR;3862goto cleanup;3863}38643865/*3866 * It's really undefined to call this function in an active3867 * repository or when there are existing references: we are3868 * only locking and changing packed-refs, so (1) any3869 * simultaneous processes might try to change a reference at3870 * the same time we do, and (2) any existing loose versions of3871 * the references that we are setting would have precedence3872 * over our values. But some remote helpers create the remote3873 * "HEAD" and "master" branches before calling this function,3874 * so here we really only check that none of the references3875 * that we are creating already exists.3876 */3877if(for_each_rawref(ref_present, &affected_refnames))3878die("BUG: initial ref transaction called with existing refs");38793880for(i =0; i < transaction->nr; i++) {3881struct ref_update *update = transaction->updates[i];38823883if((update->flags & REF_HAVE_OLD) &&3884!is_null_sha1(update->old_sha1))3885die("BUG: initial ref transaction with old_sha1 set");3886if(verify_refname_available(update->refname,3887&affected_refnames, NULL,3888 err)) {3889 ret = TRANSACTION_NAME_CONFLICT;3890goto cleanup;3891}3892}38933894if(lock_packed_refs(refs,0)) {3895strbuf_addf(err,"unable to lock packed-refs file:%s",3896strerror(errno));3897 ret = TRANSACTION_GENERIC_ERROR;3898goto cleanup;3899}39003901for(i =0; i < transaction->nr; i++) {3902struct ref_update *update = transaction->updates[i];39033904if((update->flags & REF_HAVE_NEW) &&3905!is_null_sha1(update->new_sha1))3906add_packed_ref(refs, update->refname, update->new_sha1);3907}39083909if(commit_packed_refs(refs)) {3910strbuf_addf(err,"unable to commit packed-refs file:%s",3911strerror(errno));3912 ret = TRANSACTION_GENERIC_ERROR;3913goto cleanup;3914}39153916cleanup:3917 transaction->state = REF_TRANSACTION_CLOSED;3918string_list_clear(&affected_refnames,0);3919return ret;3920}39213922struct expire_reflog_cb {3923unsigned int flags;3924 reflog_expiry_should_prune_fn *should_prune_fn;3925void*policy_cb;3926FILE*newlog;3927unsigned char last_kept_sha1[20];3928};39293930static intexpire_reflog_ent(unsigned char*osha1,unsigned char*nsha1,3931const char*email,unsigned long timestamp,int tz,3932const char*message,void*cb_data)3933{3934struct expire_reflog_cb *cb = cb_data;3935struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39363937if(cb->flags & EXPIRE_REFLOGS_REWRITE)3938 osha1 = cb->last_kept_sha1;39393940if((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3941 message, policy_cb)) {3942if(!cb->newlog)3943printf("would prune%s", message);3944else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3945printf("prune%s", message);3946}else{3947if(cb->newlog) {3948fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",3949sha1_to_hex(osha1),sha1_to_hex(nsha1),3950 email, timestamp, tz, message);3951hashcpy(cb->last_kept_sha1, nsha1);3952}3953if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3954printf("keep%s", message);3955}3956return0;3957}39583959static intfiles_reflog_expire(struct ref_store *ref_store,3960const char*refname,const unsigned char*sha1,3961unsigned int flags,3962 reflog_expiry_prepare_fn prepare_fn,3963 reflog_expiry_should_prune_fn should_prune_fn,3964 reflog_expiry_cleanup_fn cleanup_fn,3965void*policy_cb_data)3966{3967struct files_ref_store *refs =3968files_downcast(ref_store,0,"reflog_expire");3969static struct lock_file reflog_lock;3970struct expire_reflog_cb cb;3971struct ref_lock *lock;3972char*log_file;3973int status =0;3974int type;3975struct strbuf err = STRBUF_INIT;39763977memset(&cb,0,sizeof(cb));3978 cb.flags = flags;3979 cb.policy_cb = policy_cb_data;3980 cb.should_prune_fn = should_prune_fn;39813982/*3983 * The reflog file is locked by holding the lock on the3984 * reference itself, plus we might need to update the3985 * reference if --updateref was specified:3986 */3987 lock =lock_ref_sha1_basic(refs, refname, sha1,3988 NULL, NULL, REF_NODEREF,3989&type, &err);3990if(!lock) {3991error("cannot lock ref '%s':%s", refname, err.buf);3992strbuf_release(&err);3993return-1;3994}3995if(!reflog_exists(refname)) {3996unlock_ref(lock);3997return0;3998}39994000 log_file =git_pathdup("logs/%s", refname);4001if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4002/*4003 * Even though holding $GIT_DIR/logs/$reflog.lock has4004 * no locking implications, we use the lock_file4005 * machinery here anyway because it does a lot of the4006 * work we need, including cleaning up if the program4007 * exits unexpectedly.4008 */4009if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4010struct strbuf err = STRBUF_INIT;4011unable_to_lock_message(log_file, errno, &err);4012error("%s", err.buf);4013strbuf_release(&err);4014goto failure;4015}4016 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4017if(!cb.newlog) {4018error("cannot fdopen%s(%s)",4019get_lock_file_path(&reflog_lock),strerror(errno));4020goto failure;4021}4022}40234024(*prepare_fn)(refname, sha1, cb.policy_cb);4025for_each_reflog_ent(refname, expire_reflog_ent, &cb);4026(*cleanup_fn)(cb.policy_cb);40274028if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4029/*4030 * It doesn't make sense to adjust a reference pointed4031 * to by a symbolic ref based on expiring entries in4032 * the symbolic reference's reflog. Nor can we update4033 * a reference if there are no remaining reflog4034 * entries.4035 */4036int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4037!(type & REF_ISSYMREF) &&4038!is_null_sha1(cb.last_kept_sha1);40394040if(close_lock_file(&reflog_lock)) {4041 status |=error("couldn't write%s:%s", log_file,4042strerror(errno));4043}else if(update &&4044(write_in_full(get_lock_file_fd(lock->lk),4045sha1_to_hex(cb.last_kept_sha1),40) !=40||4046write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||4047close_ref(lock) <0)) {4048 status |=error("couldn't write%s",4049get_lock_file_path(lock->lk));4050rollback_lock_file(&reflog_lock);4051}else if(commit_lock_file(&reflog_lock)) {4052 status |=error("unable to write reflog '%s' (%s)",4053 log_file,strerror(errno));4054}else if(update &&commit_ref(lock)) {4055 status |=error("couldn't set%s", lock->ref_name);4056}4057}4058free(log_file);4059unlock_ref(lock);4060return status;40614062 failure:4063rollback_lock_file(&reflog_lock);4064free(log_file);4065unlock_ref(lock);4066return-1;4067}40684069static intfiles_init_db(struct ref_store *ref_store,struct strbuf *err)4070{4071/* Check validity (but we don't need the result): */4072files_downcast(ref_store,0,"init_db");40734074/*4075 * Create .git/refs/{heads,tags}4076 */4077safe_create_dir(git_path("refs/heads"),1);4078safe_create_dir(git_path("refs/tags"),1);4079if(get_shared_repository()) {4080adjust_shared_perm(git_path("refs/heads"));4081adjust_shared_perm(git_path("refs/tags"));4082}4083return0;4084}40854086struct ref_storage_be refs_be_files = {4087 NULL,4088"files",4089 files_ref_store_create,4090 files_init_db,4091 files_transaction_commit,4092 files_initial_transaction_commit,40934094 files_pack_refs,4095 files_peel_ref,4096 files_create_symref,4097 files_delete_refs,4098 files_rename_ref,40994100 files_ref_iterator_begin,4101 files_read_raw_ref,4102 files_verify_refname_available,41034104 files_reflog_iterator_begin,4105 files_for_each_reflog_ent,4106 files_for_each_reflog_ent_reverse,4107 files_reflog_exists,4108 files_create_reflog,4109 files_delete_reflog,4110 files_reflog_expire4111};