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); 168static intfiles_log_ref_write(struct files_ref_store *refs, 169const char*refname,const unsigned char*old_sha1, 170const unsigned char*new_sha1,const char*msg, 171int flags,struct strbuf *err); 172 173static struct ref_dir *get_ref_dir(struct ref_entry *entry) 174{ 175struct ref_dir *dir; 176assert(entry->flag & REF_DIR); 177 dir = &entry->u.subdir; 178if(entry->flag & REF_INCOMPLETE) { 179read_loose_refs(entry->name, dir); 180 181/* 182 * Manually add refs/bisect, which, being 183 * per-worktree, might not appear in the directory 184 * listing for refs/ in the main repo. 185 */ 186if(!strcmp(entry->name,"refs/")) { 187int pos =search_ref_dir(dir,"refs/bisect/",12); 188if(pos <0) { 189struct ref_entry *child_entry; 190 child_entry =create_dir_entry(dir->ref_store, 191"refs/bisect/", 19212,1); 193add_entry_to_dir(dir, child_entry); 194read_loose_refs("refs/bisect", 195&child_entry->u.subdir); 196} 197} 198 entry->flag &= ~REF_INCOMPLETE; 199} 200return dir; 201} 202 203static struct ref_entry *create_ref_entry(const char*refname, 204const unsigned char*sha1,int flag, 205int check_name) 206{ 207struct ref_entry *ref; 208 209if(check_name && 210check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 211die("Reference has invalid format: '%s'", refname); 212FLEX_ALLOC_STR(ref, name, refname); 213hashcpy(ref->u.value.oid.hash, sha1); 214oidclr(&ref->u.value.peeled); 215 ref->flag = flag; 216return ref; 217} 218 219static voidclear_ref_dir(struct ref_dir *dir); 220 221static voidfree_ref_entry(struct ref_entry *entry) 222{ 223if(entry->flag & REF_DIR) { 224/* 225 * Do not use get_ref_dir() here, as that might 226 * trigger the reading of loose refs. 227 */ 228clear_ref_dir(&entry->u.subdir); 229} 230free(entry); 231} 232 233/* 234 * Add a ref_entry to the end of dir (unsorted). Entry is always 235 * stored directly in dir; no recursion into subdirectories is 236 * done. 237 */ 238static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 239{ 240ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 241 dir->entries[dir->nr++] = entry; 242/* optimize for the case that entries are added in order */ 243if(dir->nr ==1|| 244(dir->nr == dir->sorted +1&& 245strcmp(dir->entries[dir->nr -2]->name, 246 dir->entries[dir->nr -1]->name) <0)) 247 dir->sorted = dir->nr; 248} 249 250/* 251 * Clear and free all entries in dir, recursively. 252 */ 253static voidclear_ref_dir(struct ref_dir *dir) 254{ 255int i; 256for(i =0; i < dir->nr; i++) 257free_ref_entry(dir->entries[i]); 258free(dir->entries); 259 dir->sorted = dir->nr = dir->alloc =0; 260 dir->entries = NULL; 261} 262 263/* 264 * Create a struct ref_entry object for the specified dirname. 265 * dirname is the name of the directory with a trailing slash (e.g., 266 * "refs/heads/") or "" for the top-level directory. 267 */ 268static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 269const char*dirname,size_t len, 270int incomplete) 271{ 272struct ref_entry *direntry; 273FLEX_ALLOC_MEM(direntry, name, dirname, len); 274 direntry->u.subdir.ref_store = ref_store; 275 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 276return direntry; 277} 278 279static intref_entry_cmp(const void*a,const void*b) 280{ 281struct ref_entry *one = *(struct ref_entry **)a; 282struct ref_entry *two = *(struct ref_entry **)b; 283returnstrcmp(one->name, two->name); 284} 285 286static voidsort_ref_dir(struct ref_dir *dir); 287 288struct string_slice { 289size_t len; 290const char*str; 291}; 292 293static intref_entry_cmp_sslice(const void*key_,const void*ent_) 294{ 295const struct string_slice *key = key_; 296const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 297int cmp =strncmp(key->str, ent->name, key->len); 298if(cmp) 299return cmp; 300return'\0'- (unsigned char)ent->name[key->len]; 301} 302 303/* 304 * Return the index of the entry with the given refname from the 305 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 306 * no such entry is found. dir must already be complete. 307 */ 308static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 309{ 310struct ref_entry **r; 311struct string_slice key; 312 313if(refname == NULL || !dir->nr) 314return-1; 315 316sort_ref_dir(dir); 317 key.len = len; 318 key.str = refname; 319 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 320 ref_entry_cmp_sslice); 321 322if(r == NULL) 323return-1; 324 325return r - dir->entries; 326} 327 328/* 329 * Search for a directory entry directly within dir (without 330 * recursing). Sort dir if necessary. subdirname must be a directory 331 * name (i.e., end in '/'). If mkdir is set, then create the 332 * directory if it is missing; otherwise, return NULL if the desired 333 * directory cannot be found. dir must already be complete. 334 */ 335static struct ref_dir *search_for_subdir(struct ref_dir *dir, 336const char*subdirname,size_t len, 337int mkdir) 338{ 339int entry_index =search_ref_dir(dir, subdirname, len); 340struct ref_entry *entry; 341if(entry_index == -1) { 342if(!mkdir) 343return NULL; 344/* 345 * Since dir is complete, the absence of a subdir 346 * means that the subdir really doesn't exist; 347 * therefore, create an empty record for it but mark 348 * the record complete. 349 */ 350 entry =create_dir_entry(dir->ref_store, subdirname, len,0); 351add_entry_to_dir(dir, entry); 352}else{ 353 entry = dir->entries[entry_index]; 354} 355returnget_ref_dir(entry); 356} 357 358/* 359 * If refname is a reference name, find the ref_dir within the dir 360 * tree that should hold refname. If refname is a directory name 361 * (i.e., ends in '/'), then return that ref_dir itself. dir must 362 * represent the top-level directory and must already be complete. 363 * Sort ref_dirs and recurse into subdirectories as necessary. If 364 * mkdir is set, then create any missing directories; otherwise, 365 * return NULL if the desired directory cannot be found. 366 */ 367static struct ref_dir *find_containing_dir(struct ref_dir *dir, 368const char*refname,int mkdir) 369{ 370const char*slash; 371for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 372size_t dirnamelen = slash - refname +1; 373struct ref_dir *subdir; 374 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 375if(!subdir) { 376 dir = NULL; 377break; 378} 379 dir = subdir; 380} 381 382return dir; 383} 384 385/* 386 * Find the value entry with the given name in dir, sorting ref_dirs 387 * and recursing into subdirectories as necessary. If the name is not 388 * found or it corresponds to a directory entry, return NULL. 389 */ 390static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 391{ 392int entry_index; 393struct ref_entry *entry; 394 dir =find_containing_dir(dir, refname,0); 395if(!dir) 396return NULL; 397 entry_index =search_ref_dir(dir, refname,strlen(refname)); 398if(entry_index == -1) 399return NULL; 400 entry = dir->entries[entry_index]; 401return(entry->flag & REF_DIR) ? NULL : entry; 402} 403 404/* 405 * Remove the entry with the given name from dir, recursing into 406 * subdirectories as necessary. If refname is the name of a directory 407 * (i.e., ends with '/'), then remove the directory and its contents. 408 * If the removal was successful, return the number of entries 409 * remaining in the directory entry that contained the deleted entry. 410 * If the name was not found, return -1. Please note that this 411 * function only deletes the entry from the cache; it does not delete 412 * it from the filesystem or ensure that other cache entries (which 413 * might be symbolic references to the removed entry) are updated. 414 * Nor does it remove any containing dir entries that might be made 415 * empty by the removal. dir must represent the top-level directory 416 * and must already be complete. 417 */ 418static intremove_entry(struct ref_dir *dir,const char*refname) 419{ 420int refname_len =strlen(refname); 421int entry_index; 422struct ref_entry *entry; 423int is_dir = refname[refname_len -1] =='/'; 424if(is_dir) { 425/* 426 * refname represents a reference directory. Remove 427 * the trailing slash; otherwise we will get the 428 * directory *representing* refname rather than the 429 * one *containing* it. 430 */ 431char*dirname =xmemdupz(refname, refname_len -1); 432 dir =find_containing_dir(dir, dirname,0); 433free(dirname); 434}else{ 435 dir =find_containing_dir(dir, refname,0); 436} 437if(!dir) 438return-1; 439 entry_index =search_ref_dir(dir, refname, refname_len); 440if(entry_index == -1) 441return-1; 442 entry = dir->entries[entry_index]; 443 444memmove(&dir->entries[entry_index], 445&dir->entries[entry_index +1], 446(dir->nr - entry_index -1) *sizeof(*dir->entries) 447); 448 dir->nr--; 449if(dir->sorted > entry_index) 450 dir->sorted--; 451free_ref_entry(entry); 452return dir->nr; 453} 454 455/* 456 * Add a ref_entry to the ref_dir (unsorted), recursing into 457 * subdirectories as necessary. dir must represent the top-level 458 * directory. Return 0 on success. 459 */ 460static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 461{ 462 dir =find_containing_dir(dir, ref->name,1); 463if(!dir) 464return-1; 465add_entry_to_dir(dir, ref); 466return0; 467} 468 469/* 470 * Emit a warning and return true iff ref1 and ref2 have the same name 471 * and the same sha1. Die if they have the same name but different 472 * sha1s. 473 */ 474static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 475{ 476if(strcmp(ref1->name, ref2->name)) 477return0; 478 479/* Duplicate name; make sure that they don't conflict: */ 480 481if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 482/* This is impossible by construction */ 483die("Reference directory conflict:%s", ref1->name); 484 485if(oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) 486die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 487 488warning("Duplicated ref:%s", ref1->name); 489return1; 490} 491 492/* 493 * Sort the entries in dir non-recursively (if they are not already 494 * sorted) and remove any duplicate entries. 495 */ 496static voidsort_ref_dir(struct ref_dir *dir) 497{ 498int i, j; 499struct ref_entry *last = NULL; 500 501/* 502 * This check also prevents passing a zero-length array to qsort(), 503 * which is a problem on some platforms. 504 */ 505if(dir->sorted == dir->nr) 506return; 507 508QSORT(dir->entries, dir->nr, ref_entry_cmp); 509 510/* Remove any duplicates: */ 511for(i =0, j =0; j < dir->nr; j++) { 512struct ref_entry *entry = dir->entries[j]; 513if(last &&is_dup_ref(last, entry)) 514free_ref_entry(entry); 515else 516 last = dir->entries[i++] = entry; 517} 518 dir->sorted = dir->nr = i; 519} 520 521/* 522 * Return true if refname, which has the specified oid and flags, can 523 * be resolved to an object in the database. If the referred-to object 524 * does not exist, emit a warning and return false. 525 */ 526static intref_resolves_to_object(const char*refname, 527const struct object_id *oid, 528unsigned int flags) 529{ 530if(flags & REF_ISBROKEN) 531return0; 532if(!has_sha1_file(oid->hash)) { 533error("%sdoes not point to a valid object!", refname); 534return0; 535} 536return1; 537} 538 539/* 540 * Return true if the reference described by entry can be resolved to 541 * an object in the database; otherwise, emit a warning and return 542 * false. 543 */ 544static intentry_resolves_to_object(struct ref_entry *entry) 545{ 546returnref_resolves_to_object(entry->name, 547&entry->u.value.oid, entry->flag); 548} 549 550typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 551 552/* 553 * Call fn for each reference in dir that has index in the range 554 * offset <= index < dir->nr. Recurse into subdirectories that are in 555 * that index range, sorting them before iterating. This function 556 * does not sort dir itself; it should be sorted beforehand. fn is 557 * called for all references, including broken ones. 558 */ 559static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 560 each_ref_entry_fn fn,void*cb_data) 561{ 562int i; 563assert(dir->sorted == dir->nr); 564for(i = offset; i < dir->nr; i++) { 565struct ref_entry *entry = dir->entries[i]; 566int retval; 567if(entry->flag & REF_DIR) { 568struct ref_dir *subdir =get_ref_dir(entry); 569sort_ref_dir(subdir); 570 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 571}else{ 572 retval =fn(entry, cb_data); 573} 574if(retval) 575return retval; 576} 577return0; 578} 579 580/* 581 * Load all of the refs from the dir into our in-memory cache. The hard work 582 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 583 * through all of the sub-directories. We do not even need to care about 584 * sorting, as traversal order does not matter to us. 585 */ 586static voidprime_ref_dir(struct ref_dir *dir) 587{ 588int i; 589for(i =0; i < dir->nr; i++) { 590struct ref_entry *entry = dir->entries[i]; 591if(entry->flag & REF_DIR) 592prime_ref_dir(get_ref_dir(entry)); 593} 594} 595 596/* 597 * A level in the reference hierarchy that is currently being iterated 598 * through. 599 */ 600struct cache_ref_iterator_level { 601/* 602 * The ref_dir being iterated over at this level. The ref_dir 603 * is sorted before being stored here. 604 */ 605struct ref_dir *dir; 606 607/* 608 * The index of the current entry within dir (which might 609 * itself be a directory). If index == -1, then the iteration 610 * hasn't yet begun. If index == dir->nr, then the iteration 611 * through this level is over. 612 */ 613int index; 614}; 615 616/* 617 * Represent an iteration through a ref_dir in the memory cache. The 618 * iteration recurses through subdirectories. 619 */ 620struct cache_ref_iterator { 621struct ref_iterator base; 622 623/* 624 * The number of levels currently on the stack. This is always 625 * at least 1, because when it becomes zero the iteration is 626 * ended and this struct is freed. 627 */ 628size_t levels_nr; 629 630/* The number of levels that have been allocated on the stack */ 631size_t levels_alloc; 632 633/* 634 * A stack of levels. levels[0] is the uppermost level that is 635 * being iterated over in this iteration. (This is not 636 * necessary the top level in the references hierarchy. If we 637 * are iterating through a subtree, then levels[0] will hold 638 * the ref_dir for that subtree, and subsequent levels will go 639 * on from there.) 640 */ 641struct cache_ref_iterator_level *levels; 642}; 643 644static intcache_ref_iterator_advance(struct ref_iterator *ref_iterator) 645{ 646struct cache_ref_iterator *iter = 647(struct cache_ref_iterator *)ref_iterator; 648 649while(1) { 650struct cache_ref_iterator_level *level = 651&iter->levels[iter->levels_nr -1]; 652struct ref_dir *dir = level->dir; 653struct ref_entry *entry; 654 655if(level->index == -1) 656sort_ref_dir(dir); 657 658if(++level->index == level->dir->nr) { 659/* This level is exhausted; pop up a level */ 660if(--iter->levels_nr ==0) 661returnref_iterator_abort(ref_iterator); 662 663continue; 664} 665 666 entry = dir->entries[level->index]; 667 668if(entry->flag & REF_DIR) { 669/* push down a level */ 670ALLOC_GROW(iter->levels, iter->levels_nr +1, 671 iter->levels_alloc); 672 673 level = &iter->levels[iter->levels_nr++]; 674 level->dir =get_ref_dir(entry); 675 level->index = -1; 676}else{ 677 iter->base.refname = entry->name; 678 iter->base.oid = &entry->u.value.oid; 679 iter->base.flags = entry->flag; 680return ITER_OK; 681} 682} 683} 684 685static enum peel_status peel_entry(struct ref_entry *entry,int repeel); 686 687static intcache_ref_iterator_peel(struct ref_iterator *ref_iterator, 688struct object_id *peeled) 689{ 690struct cache_ref_iterator *iter = 691(struct cache_ref_iterator *)ref_iterator; 692struct cache_ref_iterator_level *level; 693struct ref_entry *entry; 694 695 level = &iter->levels[iter->levels_nr -1]; 696 697if(level->index == -1) 698die("BUG: peel called before advance for cache iterator"); 699 700 entry = level->dir->entries[level->index]; 701 702if(peel_entry(entry,0)) 703return-1; 704oidcpy(peeled, &entry->u.value.peeled); 705return0; 706} 707 708static intcache_ref_iterator_abort(struct ref_iterator *ref_iterator) 709{ 710struct cache_ref_iterator *iter = 711(struct cache_ref_iterator *)ref_iterator; 712 713free(iter->levels); 714base_ref_iterator_free(ref_iterator); 715return ITER_DONE; 716} 717 718static struct ref_iterator_vtable cache_ref_iterator_vtable = { 719 cache_ref_iterator_advance, 720 cache_ref_iterator_peel, 721 cache_ref_iterator_abort 722}; 723 724static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir) 725{ 726struct cache_ref_iterator *iter; 727struct ref_iterator *ref_iterator; 728struct cache_ref_iterator_level *level; 729 730 iter =xcalloc(1,sizeof(*iter)); 731 ref_iterator = &iter->base; 732base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable); 733ALLOC_GROW(iter->levels,10, iter->levels_alloc); 734 735 iter->levels_nr =1; 736 level = &iter->levels[0]; 737 level->index = -1; 738 level->dir = dir; 739 740return ref_iterator; 741} 742 743struct nonmatching_ref_data { 744const struct string_list *skip; 745const char*conflicting_refname; 746}; 747 748static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 749{ 750struct nonmatching_ref_data *data = vdata; 751 752if(data->skip &&string_list_has_string(data->skip, entry->name)) 753return0; 754 755 data->conflicting_refname = entry->name; 756return1; 757} 758 759/* 760 * Return 0 if a reference named refname could be created without 761 * conflicting with the name of an existing reference in dir. 762 * See verify_refname_available for more information. 763 */ 764static intverify_refname_available_dir(const char*refname, 765const struct string_list *extras, 766const struct string_list *skip, 767struct ref_dir *dir, 768struct strbuf *err) 769{ 770const char*slash; 771const char*extra_refname; 772int pos; 773struct strbuf dirname = STRBUF_INIT; 774int ret = -1; 775 776/* 777 * For the sake of comments in this function, suppose that 778 * refname is "refs/foo/bar". 779 */ 780 781assert(err); 782 783strbuf_grow(&dirname,strlen(refname) +1); 784for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 785/* Expand dirname to the new prefix, not including the trailing slash: */ 786strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); 787 788/* 789 * We are still at a leading dir of the refname (e.g., 790 * "refs/foo"; if there is a reference with that name, 791 * it is a conflict, *unless* it is in skip. 792 */ 793if(dir) { 794 pos =search_ref_dir(dir, dirname.buf, dirname.len); 795if(pos >=0&& 796(!skip || !string_list_has_string(skip, dirname.buf))) { 797/* 798 * We found a reference whose name is 799 * a proper prefix of refname; e.g., 800 * "refs/foo", and is not in skip. 801 */ 802strbuf_addf(err,"'%s' exists; cannot create '%s'", 803 dirname.buf, refname); 804goto cleanup; 805} 806} 807 808if(extras &&string_list_has_string(extras, dirname.buf) && 809(!skip || !string_list_has_string(skip, dirname.buf))) { 810strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 811 refname, dirname.buf); 812goto cleanup; 813} 814 815/* 816 * Otherwise, we can try to continue our search with 817 * the next component. So try to look up the 818 * directory, e.g., "refs/foo/". If we come up empty, 819 * we know there is nothing under this whole prefix, 820 * but even in that case we still have to continue the 821 * search for conflicts with extras. 822 */ 823strbuf_addch(&dirname,'/'); 824if(dir) { 825 pos =search_ref_dir(dir, dirname.buf, dirname.len); 826if(pos <0) { 827/* 828 * There was no directory "refs/foo/", 829 * so there is nothing under this 830 * whole prefix. So there is no need 831 * to continue looking for conflicting 832 * references. But we need to continue 833 * looking for conflicting extras. 834 */ 835 dir = NULL; 836}else{ 837 dir =get_ref_dir(dir->entries[pos]); 838} 839} 840} 841 842/* 843 * We are at the leaf of our refname (e.g., "refs/foo/bar"). 844 * There is no point in searching for a reference with that 845 * name, because a refname isn't considered to conflict with 846 * itself. But we still need to check for references whose 847 * names are in the "refs/foo/bar/" namespace, because they 848 * *do* conflict. 849 */ 850strbuf_addstr(&dirname, refname + dirname.len); 851strbuf_addch(&dirname,'/'); 852 853if(dir) { 854 pos =search_ref_dir(dir, dirname.buf, dirname.len); 855 856if(pos >=0) { 857/* 858 * We found a directory named "$refname/" 859 * (e.g., "refs/foo/bar/"). It is a problem 860 * iff it contains any ref that is not in 861 * "skip". 862 */ 863struct nonmatching_ref_data data; 864 865 data.skip = skip; 866 data.conflicting_refname = NULL; 867 dir =get_ref_dir(dir->entries[pos]); 868sort_ref_dir(dir); 869if(do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) { 870strbuf_addf(err,"'%s' exists; cannot create '%s'", 871 data.conflicting_refname, refname); 872goto cleanup; 873} 874} 875} 876 877 extra_refname =find_descendant_ref(dirname.buf, extras, skip); 878if(extra_refname) 879strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 880 refname, extra_refname); 881else 882 ret =0; 883 884cleanup: 885strbuf_release(&dirname); 886return ret; 887} 888 889struct packed_ref_cache { 890struct ref_entry *root; 891 892/* 893 * Count of references to the data structure in this instance, 894 * including the pointer from files_ref_store::packed if any. 895 * The data will not be freed as long as the reference count 896 * is nonzero. 897 */ 898unsigned int referrers; 899 900/* 901 * Iff the packed-refs file associated with this instance is 902 * currently locked for writing, this points at the associated 903 * lock (which is owned by somebody else). The referrer count 904 * is also incremented when the file is locked and decremented 905 * when it is unlocked. 906 */ 907struct lock_file *lock; 908 909/* The metadata from when this packed-refs cache was read */ 910struct stat_validity validity; 911}; 912 913/* 914 * Future: need to be in "struct repository" 915 * when doing a full libification. 916 */ 917struct files_ref_store { 918struct ref_store base; 919 920/* 921 * The name of the submodule represented by this object, or 922 * NULL if it represents the main repository's reference 923 * store: 924 */ 925const char*submodule; 926 927char*packed_refs_path; 928 929struct ref_entry *loose; 930struct packed_ref_cache *packed; 931}; 932 933/* Lock used for the main packed-refs file: */ 934static struct lock_file packlock; 935 936/* 937 * Increment the reference count of *packed_refs. 938 */ 939static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 940{ 941 packed_refs->referrers++; 942} 943 944/* 945 * Decrease the reference count of *packed_refs. If it goes to zero, 946 * free *packed_refs and return true; otherwise return false. 947 */ 948static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 949{ 950if(!--packed_refs->referrers) { 951free_ref_entry(packed_refs->root); 952stat_validity_clear(&packed_refs->validity); 953free(packed_refs); 954return1; 955}else{ 956return0; 957} 958} 959 960static voidclear_packed_ref_cache(struct files_ref_store *refs) 961{ 962if(refs->packed) { 963struct packed_ref_cache *packed_refs = refs->packed; 964 965if(packed_refs->lock) 966die("internal error: packed-ref cache cleared while locked"); 967 refs->packed = NULL; 968release_packed_ref_cache(packed_refs); 969} 970} 971 972static voidclear_loose_ref_cache(struct files_ref_store *refs) 973{ 974if(refs->loose) { 975free_ref_entry(refs->loose); 976 refs->loose = NULL; 977} 978} 979 980/* 981 * Create a new submodule ref cache and add it to the internal 982 * set of caches. 983 */ 984static struct ref_store *files_ref_store_create(const char*submodule) 985{ 986struct files_ref_store *refs =xcalloc(1,sizeof(*refs)); 987struct ref_store *ref_store = (struct ref_store *)refs; 988 989base_ref_store_init(ref_store, &refs_be_files); 990 991if(submodule) { 992 refs->submodule =xstrdup(submodule); 993 refs->packed_refs_path =git_pathdup_submodule( 994 refs->submodule,"packed-refs"); 995return ref_store; 996} 997 998 refs->packed_refs_path =git_pathdup("packed-refs"); 9991000return ref_store;1001}10021003/*1004 * Die if refs is for a submodule (i.e., not for the main repository).1005 * caller is used in any necessary error messages.1006 */1007static voidfiles_assert_main_repository(struct files_ref_store *refs,1008const char*caller)1009{1010if(refs->submodule)1011die("BUG:%scalled for a submodule", caller);1012}10131014/*1015 * Downcast ref_store to files_ref_store. Die if ref_store is not a1016 * files_ref_store. If submodule_allowed is not true, then also die if1017 * files_ref_store is for a submodule (i.e., not for the main1018 * repository). caller is used in any necessary error messages.1019 */1020static struct files_ref_store *files_downcast(1021struct ref_store *ref_store,int submodule_allowed,1022const char*caller)1023{1024struct files_ref_store *refs;10251026if(ref_store->be != &refs_be_files)1027die("BUG: ref_store is type\"%s\"not\"files\"in%s",1028 ref_store->be->name, caller);10291030 refs = (struct files_ref_store *)ref_store;10311032if(!submodule_allowed)1033files_assert_main_repository(refs, caller);10341035return refs;1036}10371038/* The length of a peeled reference line in packed-refs, including EOL: */1039#define PEELED_LINE_LENGTH 4210401041/*1042 * The packed-refs header line that we write out. Perhaps other1043 * traits will be added later. The trailing space is required.1044 */1045static const char PACKED_REFS_HEADER[] =1046"# pack-refs with: peeled fully-peeled\n";10471048/*1049 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1050 * Return a pointer to the refname within the line (null-terminated),1051 * or NULL if there was a problem.1052 */1053static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1054{1055const char*ref;10561057/*1058 * 42: the answer to everything.1059 *1060 * In this case, it happens to be the answer to1061 * 40 (length of sha1 hex representation)1062 * +1 (space in between hex and name)1063 * +1 (newline at the end of the line)1064 */1065if(line->len <=42)1066return NULL;10671068if(get_sha1_hex(line->buf, sha1) <0)1069return NULL;1070if(!isspace(line->buf[40]))1071return NULL;10721073 ref = line->buf +41;1074if(isspace(*ref))1075return NULL;10761077if(line->buf[line->len -1] !='\n')1078return NULL;1079 line->buf[--line->len] =0;10801081return ref;1082}10831084/*1085 * Read f, which is a packed-refs file, into dir.1086 *1087 * A comment line of the form "# pack-refs with: " may contain zero or1088 * more traits. We interpret the traits as follows:1089 *1090 * No traits:1091 *1092 * Probably no references are peeled. But if the file contains a1093 * peeled value for a reference, we will use it.1094 *1095 * peeled:1096 *1097 * References under "refs/tags/", if they *can* be peeled, *are*1098 * peeled in this file. References outside of "refs/tags/" are1099 * probably not peeled even if they could have been, but if we find1100 * a peeled value for such a reference we will use it.1101 *1102 * fully-peeled:1103 *1104 * All references in the file that can be peeled are peeled.1105 * Inversely (and this is more important), any references in the1106 * file for which no peeled value is recorded is not peelable. This1107 * trait should typically be written alongside "peeled" for1108 * compatibility with older clients, but we do not require it1109 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1110 */1111static voidread_packed_refs(FILE*f,struct ref_dir *dir)1112{1113struct ref_entry *last = NULL;1114struct strbuf line = STRBUF_INIT;1115enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11161117while(strbuf_getwholeline(&line, f,'\n') != EOF) {1118unsigned char sha1[20];1119const char*refname;1120const char*traits;11211122if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1123if(strstr(traits," fully-peeled "))1124 peeled = PEELED_FULLY;1125else if(strstr(traits," peeled "))1126 peeled = PEELED_TAGS;1127/* perhaps other traits later as well */1128continue;1129}11301131 refname =parse_ref_line(&line, sha1);1132if(refname) {1133int flag = REF_ISPACKED;11341135if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1136if(!refname_is_safe(refname))1137die("packed refname is dangerous:%s", refname);1138hashclr(sha1);1139 flag |= REF_BAD_NAME | REF_ISBROKEN;1140}1141 last =create_ref_entry(refname, sha1, flag,0);1142if(peeled == PEELED_FULLY ||1143(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1144 last->flag |= REF_KNOWS_PEELED;1145add_ref(dir, last);1146continue;1147}1148if(last &&1149 line.buf[0] =='^'&&1150 line.len == PEELED_LINE_LENGTH &&1151 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1152!get_sha1_hex(line.buf +1, sha1)) {1153hashcpy(last->u.value.peeled.hash, sha1);1154/*1155 * Regardless of what the file header said,1156 * we definitely know the value of *this*1157 * reference:1158 */1159 last->flag |= REF_KNOWS_PEELED;1160}1161}11621163strbuf_release(&line);1164}11651166static const char*files_packed_refs_path(struct files_ref_store *refs)1167{1168return refs->packed_refs_path;1169}11701171static voidfiles_reflog_path(struct files_ref_store *refs,1172struct strbuf *sb,1173const char*refname)1174{1175if(!refname) {1176strbuf_git_path(sb,"logs");1177return;1178}11791180strbuf_git_path(sb,"logs/%s", refname);1181}11821183/*1184 * Get the packed_ref_cache for the specified files_ref_store,1185 * creating it if necessary.1186 */1187static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1188{1189const char*packed_refs_file =files_packed_refs_path(refs);11901191if(refs->packed &&1192!stat_validity_check(&refs->packed->validity, packed_refs_file))1193clear_packed_ref_cache(refs);11941195if(!refs->packed) {1196FILE*f;11971198 refs->packed =xcalloc(1,sizeof(*refs->packed));1199acquire_packed_ref_cache(refs->packed);1200 refs->packed->root =create_dir_entry(refs,"",0,0);1201 f =fopen(packed_refs_file,"r");1202if(f) {1203stat_validity_update(&refs->packed->validity,fileno(f));1204read_packed_refs(f,get_ref_dir(refs->packed->root));1205fclose(f);1206}1207}1208return refs->packed;1209}12101211static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1212{1213returnget_ref_dir(packed_ref_cache->root);1214}12151216static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1217{1218returnget_packed_ref_dir(get_packed_ref_cache(refs));1219}12201221/*1222 * Add a reference to the in-memory packed reference cache. This may1223 * only be called while the packed-refs file is locked (see1224 * lock_packed_refs()). To actually write the packed-refs file, call1225 * commit_packed_refs().1226 */1227static voidadd_packed_ref(struct files_ref_store *refs,1228const char*refname,const unsigned char*sha1)1229{1230struct packed_ref_cache *packed_ref_cache =get_packed_ref_cache(refs);12311232if(!packed_ref_cache->lock)1233die("internal error: packed refs not locked");1234add_ref(get_packed_ref_dir(packed_ref_cache),1235create_ref_entry(refname, sha1, REF_ISPACKED,1));1236}12371238/*1239 * Read the loose references from the namespace dirname into dir1240 * (without recursing). dirname must end with '/'. dir must be the1241 * directory entry corresponding to dirname.1242 */1243static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1244{1245struct files_ref_store *refs = dir->ref_store;1246DIR*d;1247struct dirent *de;1248int dirnamelen =strlen(dirname);1249struct strbuf refname;1250struct strbuf path = STRBUF_INIT;1251size_t path_baselen;1252int err =0;12531254if(refs->submodule)1255 err =strbuf_git_path_submodule(&path, refs->submodule,"%s", dirname);1256else1257strbuf_git_path(&path,"%s", dirname);1258 path_baselen = path.len;12591260if(err) {1261strbuf_release(&path);1262return;1263}12641265 d =opendir(path.buf);1266if(!d) {1267strbuf_release(&path);1268return;1269}12701271strbuf_init(&refname, dirnamelen +257);1272strbuf_add(&refname, dirname, dirnamelen);12731274while((de =readdir(d)) != NULL) {1275unsigned char sha1[20];1276struct stat st;1277int flag;12781279if(de->d_name[0] =='.')1280continue;1281if(ends_with(de->d_name,".lock"))1282continue;1283strbuf_addstr(&refname, de->d_name);1284strbuf_addstr(&path, de->d_name);1285if(stat(path.buf, &st) <0) {1286;/* silently ignore */1287}else if(S_ISDIR(st.st_mode)) {1288strbuf_addch(&refname,'/');1289add_entry_to_dir(dir,1290create_dir_entry(refs, refname.buf,1291 refname.len,1));1292}else{1293if(!resolve_ref_recursively(&refs->base,1294 refname.buf,1295 RESOLVE_REF_READING,1296 sha1, &flag)) {1297hashclr(sha1);1298 flag |= REF_ISBROKEN;1299}else if(is_null_sha1(sha1)) {1300/*1301 * It is so astronomically unlikely1302 * that NULL_SHA1 is the SHA-1 of an1303 * actual object that we consider its1304 * appearance in a loose reference1305 * file to be repo corruption1306 * (probably due to a software bug).1307 */1308 flag |= REF_ISBROKEN;1309}13101311if(check_refname_format(refname.buf,1312 REFNAME_ALLOW_ONELEVEL)) {1313if(!refname_is_safe(refname.buf))1314die("loose refname is dangerous:%s", refname.buf);1315hashclr(sha1);1316 flag |= REF_BAD_NAME | REF_ISBROKEN;1317}1318add_entry_to_dir(dir,1319create_ref_entry(refname.buf, sha1, flag,0));1320}1321strbuf_setlen(&refname, dirnamelen);1322strbuf_setlen(&path, path_baselen);1323}1324strbuf_release(&refname);1325strbuf_release(&path);1326closedir(d);1327}13281329static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1330{1331if(!refs->loose) {1332/*1333 * Mark the top-level directory complete because we1334 * are about to read the only subdirectory that can1335 * hold references:1336 */1337 refs->loose =create_dir_entry(refs,"",0,0);1338/*1339 * Create an incomplete entry for "refs/":1340 */1341add_entry_to_dir(get_ref_dir(refs->loose),1342create_dir_entry(refs,"refs/",5,1));1343}1344returnget_ref_dir(refs->loose);1345}13461347/*1348 * Return the ref_entry for the given refname from the packed1349 * references. If it does not exist, return NULL.1350 */1351static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1352const char*refname)1353{1354returnfind_ref(get_packed_refs(refs), refname);1355}13561357/*1358 * A loose ref file doesn't exist; check for a packed ref.1359 */1360static intresolve_packed_ref(struct files_ref_store *refs,1361const char*refname,1362unsigned char*sha1,unsigned int*flags)1363{1364struct ref_entry *entry;13651366/*1367 * The loose reference file does not exist; check for a packed1368 * reference.1369 */1370 entry =get_packed_ref(refs, refname);1371if(entry) {1372hashcpy(sha1, entry->u.value.oid.hash);1373*flags |= REF_ISPACKED;1374return0;1375}1376/* refname is not a packed reference. */1377return-1;1378}13791380static intfiles_read_raw_ref(struct ref_store *ref_store,1381const char*refname,unsigned char*sha1,1382struct strbuf *referent,unsigned int*type)1383{1384struct files_ref_store *refs =1385files_downcast(ref_store,1,"read_raw_ref");1386struct strbuf sb_contents = STRBUF_INIT;1387struct strbuf sb_path = STRBUF_INIT;1388const char*path;1389const char*buf;1390struct stat st;1391int fd;1392int ret = -1;1393int save_errno;1394int remaining_retries =3;13951396*type =0;1397strbuf_reset(&sb_path);13981399if(refs->submodule)1400strbuf_git_path_submodule(&sb_path, refs->submodule,"%s", refname);1401else1402strbuf_git_path(&sb_path,"%s", refname);14031404 path = sb_path.buf;14051406stat_ref:1407/*1408 * We might have to loop back here to avoid a race1409 * condition: first we lstat() the file, then we try1410 * to read it as a link or as a file. But if somebody1411 * changes the type of the file (file <-> directory1412 * <-> symlink) between the lstat() and reading, then1413 * we don't want to report that as an error but rather1414 * try again starting with the lstat().1415 *1416 * We'll keep a count of the retries, though, just to avoid1417 * any confusing situation sending us into an infinite loop.1418 */14191420if(remaining_retries-- <=0)1421goto out;14221423if(lstat(path, &st) <0) {1424if(errno != ENOENT)1425goto out;1426if(resolve_packed_ref(refs, refname, sha1, type)) {1427 errno = ENOENT;1428goto out;1429}1430 ret =0;1431goto out;1432}14331434/* Follow "normalized" - ie "refs/.." symlinks by hand */1435if(S_ISLNK(st.st_mode)) {1436strbuf_reset(&sb_contents);1437if(strbuf_readlink(&sb_contents, path,0) <0) {1438if(errno == ENOENT || errno == EINVAL)1439/* inconsistent with lstat; retry */1440goto stat_ref;1441else1442goto out;1443}1444if(starts_with(sb_contents.buf,"refs/") &&1445!check_refname_format(sb_contents.buf,0)) {1446strbuf_swap(&sb_contents, referent);1447*type |= REF_ISSYMREF;1448 ret =0;1449goto out;1450}1451/*1452 * It doesn't look like a refname; fall through to just1453 * treating it like a non-symlink, and reading whatever it1454 * points to.1455 */1456}14571458/* Is it a directory? */1459if(S_ISDIR(st.st_mode)) {1460/*1461 * Even though there is a directory where the loose1462 * ref is supposed to be, there could still be a1463 * packed ref:1464 */1465if(resolve_packed_ref(refs, refname, sha1, type)) {1466 errno = EISDIR;1467goto out;1468}1469 ret =0;1470goto out;1471}14721473/*1474 * Anything else, just open it and try to use it as1475 * a ref1476 */1477 fd =open(path, O_RDONLY);1478if(fd <0) {1479if(errno == ENOENT && !S_ISLNK(st.st_mode))1480/* inconsistent with lstat; retry */1481goto stat_ref;1482else1483goto out;1484}1485strbuf_reset(&sb_contents);1486if(strbuf_read(&sb_contents, fd,256) <0) {1487int save_errno = errno;1488close(fd);1489 errno = save_errno;1490goto out;1491}1492close(fd);1493strbuf_rtrim(&sb_contents);1494 buf = sb_contents.buf;1495if(starts_with(buf,"ref:")) {1496 buf +=4;1497while(isspace(*buf))1498 buf++;14991500strbuf_reset(referent);1501strbuf_addstr(referent, buf);1502*type |= REF_ISSYMREF;1503 ret =0;1504goto out;1505}15061507/*1508 * Please note that FETCH_HEAD has additional1509 * data after the sha.1510 */1511if(get_sha1_hex(buf, sha1) ||1512(buf[40] !='\0'&& !isspace(buf[40]))) {1513*type |= REF_ISBROKEN;1514 errno = EINVAL;1515goto out;1516}15171518 ret =0;15191520out:1521 save_errno = errno;1522strbuf_release(&sb_path);1523strbuf_release(&sb_contents);1524 errno = save_errno;1525return ret;1526}15271528static voidunlock_ref(struct ref_lock *lock)1529{1530/* Do not free lock->lk -- atexit() still looks at them */1531if(lock->lk)1532rollback_lock_file(lock->lk);1533free(lock->ref_name);1534free(lock);1535}15361537/*1538 * Lock refname, without following symrefs, and set *lock_p to point1539 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1540 * and type similarly to read_raw_ref().1541 *1542 * The caller must verify that refname is a "safe" reference name (in1543 * the sense of refname_is_safe()) before calling this function.1544 *1545 * If the reference doesn't already exist, verify that refname doesn't1546 * have a D/F conflict with any existing references. extras and skip1547 * are passed to verify_refname_available_dir() for this check.1548 *1549 * If mustexist is not set and the reference is not found or is1550 * broken, lock the reference anyway but clear sha1.1551 *1552 * Return 0 on success. On failure, write an error message to err and1553 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1554 *1555 * Implementation note: This function is basically1556 *1557 * lock reference1558 * read_raw_ref()1559 *1560 * but it includes a lot more code to1561 * - Deal with possible races with other processes1562 * - Avoid calling verify_refname_available_dir() when it can be1563 * avoided, namely if we were successfully able to read the ref1564 * - Generate informative error messages in the case of failure1565 */1566static intlock_raw_ref(struct files_ref_store *refs,1567const char*refname,int mustexist,1568const struct string_list *extras,1569const struct string_list *skip,1570struct ref_lock **lock_p,1571struct strbuf *referent,1572unsigned int*type,1573struct strbuf *err)1574{1575struct ref_lock *lock;1576struct strbuf ref_file = STRBUF_INIT;1577int attempts_remaining =3;1578int ret = TRANSACTION_GENERIC_ERROR;15791580assert(err);1581files_assert_main_repository(refs,"lock_raw_ref");15821583*type =0;15841585/* First lock the file so it can't change out from under us. */15861587*lock_p = lock =xcalloc(1,sizeof(*lock));15881589 lock->ref_name =xstrdup(refname);1590strbuf_git_path(&ref_file,"%s", refname);15911592retry:1593switch(safe_create_leading_directories(ref_file.buf)) {1594case SCLD_OK:1595break;/* success */1596case SCLD_EXISTS:1597/*1598 * Suppose refname is "refs/foo/bar". We just failed1599 * to create the containing directory, "refs/foo",1600 * because there was a non-directory in the way. This1601 * indicates a D/F conflict, probably because of1602 * another reference such as "refs/foo". There is no1603 * reason to expect this error to be transitory.1604 */1605if(verify_refname_available(refname, extras, skip, err)) {1606if(mustexist) {1607/*1608 * To the user the relevant error is1609 * that the "mustexist" reference is1610 * missing:1611 */1612strbuf_reset(err);1613strbuf_addf(err,"unable to resolve reference '%s'",1614 refname);1615}else{1616/*1617 * The error message set by1618 * verify_refname_available_dir() is OK.1619 */1620 ret = TRANSACTION_NAME_CONFLICT;1621}1622}else{1623/*1624 * The file that is in the way isn't a loose1625 * reference. Report it as a low-level1626 * failure.1627 */1628strbuf_addf(err,"unable to create lock file%s.lock; "1629"non-directory in the way",1630 ref_file.buf);1631}1632goto error_return;1633case SCLD_VANISHED:1634/* Maybe another process was tidying up. Try again. */1635if(--attempts_remaining >0)1636goto retry;1637/* fall through */1638default:1639strbuf_addf(err,"unable to create directory for%s",1640 ref_file.buf);1641goto error_return;1642}16431644if(!lock->lk)1645 lock->lk =xcalloc(1,sizeof(struct lock_file));16461647if(hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) <0) {1648if(errno == ENOENT && --attempts_remaining >0) {1649/*1650 * Maybe somebody just deleted one of the1651 * directories leading to ref_file. Try1652 * again:1653 */1654goto retry;1655}else{1656unable_to_lock_message(ref_file.buf, errno, err);1657goto error_return;1658}1659}16601661/*1662 * Now we hold the lock and can read the reference without1663 * fear that its value will change.1664 */16651666if(files_read_raw_ref(&refs->base, refname,1667 lock->old_oid.hash, referent, type)) {1668if(errno == ENOENT) {1669if(mustexist) {1670/* Garden variety missing reference. */1671strbuf_addf(err,"unable to resolve reference '%s'",1672 refname);1673goto error_return;1674}else{1675/*1676 * Reference is missing, but that's OK. We1677 * know that there is not a conflict with1678 * another loose reference because1679 * (supposing that we are trying to lock1680 * reference "refs/foo/bar"):1681 *1682 * - We were successfully able to create1683 * the lockfile refs/foo/bar.lock, so we1684 * know there cannot be a loose reference1685 * named "refs/foo".1686 *1687 * - We got ENOENT and not EISDIR, so we1688 * know that there cannot be a loose1689 * reference named "refs/foo/bar/baz".1690 */1691}1692}else if(errno == EISDIR) {1693/*1694 * There is a directory in the way. It might have1695 * contained references that have been deleted. If1696 * we don't require that the reference already1697 * exists, try to remove the directory so that it1698 * doesn't cause trouble when we want to rename the1699 * lockfile into place later.1700 */1701if(mustexist) {1702/* Garden variety missing reference. */1703strbuf_addf(err,"unable to resolve reference '%s'",1704 refname);1705goto error_return;1706}else if(remove_dir_recursively(&ref_file,1707 REMOVE_DIR_EMPTY_ONLY)) {1708if(verify_refname_available_dir(1709 refname, extras, skip,1710get_loose_refs(refs),1711 err)) {1712/*1713 * The error message set by1714 * verify_refname_available() is OK.1715 */1716 ret = TRANSACTION_NAME_CONFLICT;1717goto error_return;1718}else{1719/*1720 * We can't delete the directory,1721 * but we also don't know of any1722 * references that it should1723 * contain.1724 */1725strbuf_addf(err,"there is a non-empty directory '%s' "1726"blocking reference '%s'",1727 ref_file.buf, refname);1728goto error_return;1729}1730}1731}else if(errno == EINVAL && (*type & REF_ISBROKEN)) {1732strbuf_addf(err,"unable to resolve reference '%s': "1733"reference broken", refname);1734goto error_return;1735}else{1736strbuf_addf(err,"unable to resolve reference '%s':%s",1737 refname,strerror(errno));1738goto error_return;1739}17401741/*1742 * If the ref did not exist and we are creating it,1743 * make sure there is no existing packed ref whose1744 * name begins with our refname, nor a packed ref1745 * whose name is a proper prefix of our refname.1746 */1747if(verify_refname_available_dir(1748 refname, extras, skip,1749get_packed_refs(refs),1750 err)) {1751goto error_return;1752}1753}17541755 ret =0;1756goto out;17571758error_return:1759unlock_ref(lock);1760*lock_p = NULL;17611762out:1763strbuf_release(&ref_file);1764return ret;1765}17661767/*1768 * Peel the entry (if possible) and return its new peel_status. If1769 * repeel is true, re-peel the entry even if there is an old peeled1770 * value that is already stored in it.1771 *1772 * It is OK to call this function with a packed reference entry that1773 * might be stale and might even refer to an object that has since1774 * been garbage-collected. In such a case, if the entry has1775 * REF_KNOWS_PEELED then leave the status unchanged and return1776 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1777 */1778static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1779{1780enum peel_status status;17811782if(entry->flag & REF_KNOWS_PEELED) {1783if(repeel) {1784 entry->flag &= ~REF_KNOWS_PEELED;1785oidclr(&entry->u.value.peeled);1786}else{1787returnis_null_oid(&entry->u.value.peeled) ?1788 PEEL_NON_TAG : PEEL_PEELED;1789}1790}1791if(entry->flag & REF_ISBROKEN)1792return PEEL_BROKEN;1793if(entry->flag & REF_ISSYMREF)1794return PEEL_IS_SYMREF;17951796 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1797if(status == PEEL_PEELED || status == PEEL_NON_TAG)1798 entry->flag |= REF_KNOWS_PEELED;1799return status;1800}18011802static intfiles_peel_ref(struct ref_store *ref_store,1803const char*refname,unsigned char*sha1)1804{1805struct files_ref_store *refs =files_downcast(ref_store,0,"peel_ref");1806int flag;1807unsigned char base[20];18081809if(current_ref_iter && current_ref_iter->refname == refname) {1810struct object_id peeled;18111812if(ref_iterator_peel(current_ref_iter, &peeled))1813return-1;1814hashcpy(sha1, peeled.hash);1815return0;1816}18171818if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1819return-1;18201821/*1822 * If the reference is packed, read its ref_entry from the1823 * cache in the hope that we already know its peeled value.1824 * We only try this optimization on packed references because1825 * (a) forcing the filling of the loose reference cache could1826 * be expensive and (b) loose references anyway usually do not1827 * have REF_KNOWS_PEELED.1828 */1829if(flag & REF_ISPACKED) {1830struct ref_entry *r =get_packed_ref(refs, refname);1831if(r) {1832if(peel_entry(r,0))1833return-1;1834hashcpy(sha1, r->u.value.peeled.hash);1835return0;1836}1837}18381839returnpeel_object(base, sha1);1840}18411842struct files_ref_iterator {1843struct ref_iterator base;18441845struct packed_ref_cache *packed_ref_cache;1846struct ref_iterator *iter0;1847unsigned int flags;1848};18491850static intfiles_ref_iterator_advance(struct ref_iterator *ref_iterator)1851{1852struct files_ref_iterator *iter =1853(struct files_ref_iterator *)ref_iterator;1854int ok;18551856while((ok =ref_iterator_advance(iter->iter0)) == ITER_OK) {1857if(iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&1858ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1859continue;18601861if(!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1862!ref_resolves_to_object(iter->iter0->refname,1863 iter->iter0->oid,1864 iter->iter0->flags))1865continue;18661867 iter->base.refname = iter->iter0->refname;1868 iter->base.oid = iter->iter0->oid;1869 iter->base.flags = iter->iter0->flags;1870return ITER_OK;1871}18721873 iter->iter0 = NULL;1874if(ref_iterator_abort(ref_iterator) != ITER_DONE)1875 ok = ITER_ERROR;18761877return ok;1878}18791880static intfiles_ref_iterator_peel(struct ref_iterator *ref_iterator,1881struct object_id *peeled)1882{1883struct files_ref_iterator *iter =1884(struct files_ref_iterator *)ref_iterator;18851886returnref_iterator_peel(iter->iter0, peeled);1887}18881889static intfiles_ref_iterator_abort(struct ref_iterator *ref_iterator)1890{1891struct files_ref_iterator *iter =1892(struct files_ref_iterator *)ref_iterator;1893int ok = ITER_DONE;18941895if(iter->iter0)1896 ok =ref_iterator_abort(iter->iter0);18971898release_packed_ref_cache(iter->packed_ref_cache);1899base_ref_iterator_free(ref_iterator);1900return ok;1901}19021903static struct ref_iterator_vtable files_ref_iterator_vtable = {1904 files_ref_iterator_advance,1905 files_ref_iterator_peel,1906 files_ref_iterator_abort1907};19081909static struct ref_iterator *files_ref_iterator_begin(1910struct ref_store *ref_store,1911const char*prefix,unsigned int flags)1912{1913struct files_ref_store *refs =1914files_downcast(ref_store,1,"ref_iterator_begin");1915struct ref_dir *loose_dir, *packed_dir;1916struct ref_iterator *loose_iter, *packed_iter;1917struct files_ref_iterator *iter;1918struct ref_iterator *ref_iterator;19191920if(ref_paranoia <0)1921 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1922if(ref_paranoia)1923 flags |= DO_FOR_EACH_INCLUDE_BROKEN;19241925 iter =xcalloc(1,sizeof(*iter));1926 ref_iterator = &iter->base;1927base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);19281929/*1930 * We must make sure that all loose refs are read before1931 * accessing the packed-refs file; this avoids a race1932 * condition if loose refs are migrated to the packed-refs1933 * file by a simultaneous process, but our in-memory view is1934 * from before the migration. We ensure this as follows:1935 * First, we call prime_ref_dir(), which pre-reads the loose1936 * references for the subtree into the cache. (If they've1937 * already been read, that's OK; we only need to guarantee1938 * that they're read before the packed refs, not *how much*1939 * before.) After that, we call get_packed_ref_cache(), which1940 * internally checks whether the packed-ref cache is up to1941 * date with what is on disk, and re-reads it if not.1942 */19431944 loose_dir =get_loose_refs(refs);19451946if(prefix && *prefix)1947 loose_dir =find_containing_dir(loose_dir, prefix,0);19481949if(loose_dir) {1950prime_ref_dir(loose_dir);1951 loose_iter =cache_ref_iterator_begin(loose_dir);1952}else{1953/* There's nothing to iterate over. */1954 loose_iter =empty_ref_iterator_begin();1955}19561957 iter->packed_ref_cache =get_packed_ref_cache(refs);1958acquire_packed_ref_cache(iter->packed_ref_cache);1959 packed_dir =get_packed_ref_dir(iter->packed_ref_cache);19601961if(prefix && *prefix)1962 packed_dir =find_containing_dir(packed_dir, prefix,0);19631964if(packed_dir) {1965 packed_iter =cache_ref_iterator_begin(packed_dir);1966}else{1967/* There's nothing to iterate over. */1968 packed_iter =empty_ref_iterator_begin();1969}19701971 iter->iter0 =overlay_ref_iterator_begin(loose_iter, packed_iter);1972 iter->flags = flags;19731974return ref_iterator;1975}19761977/*1978 * Verify that the reference locked by lock has the value old_sha1.1979 * Fail if the reference doesn't exist and mustexist is set. Return 01980 * on success. On error, write an error message to err, set errno, and1981 * return a negative value.1982 */1983static intverify_lock(struct ref_lock *lock,1984const unsigned char*old_sha1,int mustexist,1985struct strbuf *err)1986{1987assert(err);19881989if(read_ref_full(lock->ref_name,1990 mustexist ? RESOLVE_REF_READING :0,1991 lock->old_oid.hash, NULL)) {1992if(old_sha1) {1993int save_errno = errno;1994strbuf_addf(err,"can't verify ref '%s'", lock->ref_name);1995 errno = save_errno;1996return-1;1997}else{1998oidclr(&lock->old_oid);1999return0;2000}2001}2002if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {2003strbuf_addf(err,"ref '%s' is at%sbut expected%s",2004 lock->ref_name,2005oid_to_hex(&lock->old_oid),2006sha1_to_hex(old_sha1));2007 errno = EBUSY;2008return-1;2009}2010return0;2011}20122013static intremove_empty_directories(struct strbuf *path)2014{2015/*2016 * we want to create a file but there is a directory there;2017 * if that is an empty directory (or a directory that contains2018 * only empty directories), remove them.2019 */2020returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);2021}20222023static intcreate_reflock(const char*path,void*cb)2024{2025struct lock_file *lk = cb;20262027returnhold_lock_file_for_update(lk, path, LOCK_NO_DEREF) <0? -1:0;2028}20292030/*2031 * Locks a ref returning the lock on success and NULL on failure.2032 * On failure errno is set to something meaningful.2033 */2034static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,2035const char*refname,2036const unsigned char*old_sha1,2037const struct string_list *extras,2038const struct string_list *skip,2039unsigned int flags,int*type,2040struct strbuf *err)2041{2042struct strbuf ref_file = STRBUF_INIT;2043struct ref_lock *lock;2044int last_errno =0;2045int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2046int resolve_flags = RESOLVE_REF_NO_RECURSE;2047int resolved;20482049files_assert_main_repository(refs,"lock_ref_sha1_basic");2050assert(err);20512052 lock =xcalloc(1,sizeof(struct ref_lock));20532054if(mustexist)2055 resolve_flags |= RESOLVE_REF_READING;2056if(flags & REF_DELETING)2057 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20582059strbuf_git_path(&ref_file,"%s", refname);2060 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2061 lock->old_oid.hash, type);2062if(!resolved && errno == EISDIR) {2063/*2064 * we are trying to lock foo but we used to2065 * have foo/bar which now does not exist;2066 * it is normal for the empty directory 'foo'2067 * to remain.2068 */2069if(remove_empty_directories(&ref_file)) {2070 last_errno = errno;2071if(!verify_refname_available_dir(2072 refname, extras, skip,2073get_loose_refs(refs), err))2074strbuf_addf(err,"there are still refs under '%s'",2075 refname);2076goto error_return;2077}2078 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2079 lock->old_oid.hash, type);2080}2081if(!resolved) {2082 last_errno = errno;2083if(last_errno != ENOTDIR ||2084!verify_refname_available_dir(2085 refname, extras, skip,2086get_loose_refs(refs), err))2087strbuf_addf(err,"unable to resolve reference '%s':%s",2088 refname,strerror(last_errno));20892090goto error_return;2091}20922093/*2094 * If the ref did not exist and we are creating it, make sure2095 * there is no existing packed ref whose name begins with our2096 * refname, nor a packed ref whose name is a proper prefix of2097 * our refname.2098 */2099if(is_null_oid(&lock->old_oid) &&2100verify_refname_available_dir(refname, extras, skip,2101get_packed_refs(refs),2102 err)) {2103 last_errno = ENOTDIR;2104goto error_return;2105}21062107 lock->lk =xcalloc(1,sizeof(struct lock_file));21082109 lock->ref_name =xstrdup(refname);21102111if(raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {2112 last_errno = errno;2113unable_to_lock_message(ref_file.buf, errno, err);2114goto error_return;2115}21162117if(verify_lock(lock, old_sha1, mustexist, err)) {2118 last_errno = errno;2119goto error_return;2120}2121goto out;21222123 error_return:2124unlock_ref(lock);2125 lock = NULL;21262127 out:2128strbuf_release(&ref_file);2129 errno = last_errno;2130return lock;2131}21322133/*2134 * Write an entry to the packed-refs file for the specified refname.2135 * If peeled is non-NULL, write it as the entry's peeled value.2136 */2137static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2138unsigned char*peeled)2139{2140fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2141if(peeled)2142fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2143}21442145/*2146 * An each_ref_entry_fn that writes the entry to a packed-refs file.2147 */2148static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2149{2150enum peel_status peel_status =peel_entry(entry,0);21512152if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2153error("internal error:%sis not a valid packed reference!",2154 entry->name);2155write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2156 peel_status == PEEL_PEELED ?2157 entry->u.value.peeled.hash : NULL);2158return0;2159}21602161/*2162 * Lock the packed-refs file for writing. Flags is passed to2163 * hold_lock_file_for_update(). Return 0 on success. On errors, set2164 * errno appropriately and return a nonzero value.2165 */2166static intlock_packed_refs(struct files_ref_store *refs,int flags)2167{2168static int timeout_configured =0;2169static int timeout_value =1000;2170struct packed_ref_cache *packed_ref_cache;21712172files_assert_main_repository(refs,"lock_packed_refs");21732174if(!timeout_configured) {2175git_config_get_int("core.packedrefstimeout", &timeout_value);2176 timeout_configured =1;2177}21782179if(hold_lock_file_for_update_timeout(2180&packlock,files_packed_refs_path(refs),2181 flags, timeout_value) <0)2182return-1;2183/*2184 * Get the current packed-refs while holding the lock. If the2185 * packed-refs file has been modified since we last read it,2186 * this will automatically invalidate the cache and re-read2187 * the packed-refs file.2188 */2189 packed_ref_cache =get_packed_ref_cache(refs);2190 packed_ref_cache->lock = &packlock;2191/* Increment the reference count to prevent it from being freed: */2192acquire_packed_ref_cache(packed_ref_cache);2193return0;2194}21952196/*2197 * Write the current version of the packed refs cache from memory to2198 * disk. The packed-refs file must already be locked for writing (see2199 * lock_packed_refs()). Return zero on success. On errors, set errno2200 * and return a nonzero value2201 */2202static intcommit_packed_refs(struct files_ref_store *refs)2203{2204struct packed_ref_cache *packed_ref_cache =2205get_packed_ref_cache(refs);2206int error =0;2207int save_errno =0;2208FILE*out;22092210files_assert_main_repository(refs,"commit_packed_refs");22112212if(!packed_ref_cache->lock)2213die("internal error: packed-refs not locked");22142215 out =fdopen_lock_file(packed_ref_cache->lock,"w");2216if(!out)2217die_errno("unable to fdopen packed-refs descriptor");22182219fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2220do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),22210, write_packed_entry_fn, out);22222223if(commit_lock_file(packed_ref_cache->lock)) {2224 save_errno = errno;2225 error = -1;2226}2227 packed_ref_cache->lock = NULL;2228release_packed_ref_cache(packed_ref_cache);2229 errno = save_errno;2230return error;2231}22322233/*2234 * Rollback the lockfile for the packed-refs file, and discard the2235 * in-memory packed reference cache. (The packed-refs file will be2236 * read anew if it is needed again after this function is called.)2237 */2238static voidrollback_packed_refs(struct files_ref_store *refs)2239{2240struct packed_ref_cache *packed_ref_cache =2241get_packed_ref_cache(refs);22422243files_assert_main_repository(refs,"rollback_packed_refs");22442245if(!packed_ref_cache->lock)2246die("internal error: packed-refs not locked");2247rollback_lock_file(packed_ref_cache->lock);2248 packed_ref_cache->lock = NULL;2249release_packed_ref_cache(packed_ref_cache);2250clear_packed_ref_cache(refs);2251}22522253struct ref_to_prune {2254struct ref_to_prune *next;2255unsigned char sha1[20];2256char name[FLEX_ARRAY];2257};22582259struct pack_refs_cb_data {2260unsigned int flags;2261struct ref_dir *packed_refs;2262struct ref_to_prune *ref_to_prune;2263};22642265/*2266 * An each_ref_entry_fn that is run over loose references only. If2267 * the loose reference can be packed, add an entry in the packed ref2268 * cache. If the reference should be pruned, also add it to2269 * ref_to_prune in the pack_refs_cb_data.2270 */2271static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2272{2273struct pack_refs_cb_data *cb = cb_data;2274enum peel_status peel_status;2275struct ref_entry *packed_entry;2276int is_tag_ref =starts_with(entry->name,"refs/tags/");22772278/* Do not pack per-worktree refs: */2279if(ref_type(entry->name) != REF_TYPE_NORMAL)2280return0;22812282/* ALWAYS pack tags */2283if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2284return0;22852286/* Do not pack symbolic or broken refs: */2287if((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2288return0;22892290/* Add a packed ref cache entry equivalent to the loose entry. */2291 peel_status =peel_entry(entry,1);2292if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2293die("internal error peeling reference%s(%s)",2294 entry->name,oid_to_hex(&entry->u.value.oid));2295 packed_entry =find_ref(cb->packed_refs, entry->name);2296if(packed_entry) {2297/* Overwrite existing packed entry with info from loose entry */2298 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2299oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2300}else{2301 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2302 REF_ISPACKED | REF_KNOWS_PEELED,0);2303add_ref(cb->packed_refs, packed_entry);2304}2305oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);23062307/* Schedule the loose reference for pruning if requested. */2308if((cb->flags & PACK_REFS_PRUNE)) {2309struct ref_to_prune *n;2310FLEX_ALLOC_STR(n, name, entry->name);2311hashcpy(n->sha1, entry->u.value.oid.hash);2312 n->next = cb->ref_to_prune;2313 cb->ref_to_prune = n;2314}2315return0;2316}23172318enum{2319 REMOVE_EMPTY_PARENTS_REF =0x01,2320 REMOVE_EMPTY_PARENTS_REFLOG =0x022321};23222323/*2324 * Remove empty parent directories associated with the specified2325 * reference and/or its reflog, but spare [logs/]refs/ and immediate2326 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or2327 * REMOVE_EMPTY_PARENTS_REFLOG.2328 */2329static voidtry_remove_empty_parents(struct files_ref_store *refs,2330const char*refname,2331unsigned int flags)2332{2333struct strbuf buf = STRBUF_INIT;2334struct strbuf sb = STRBUF_INIT;2335char*p, *q;2336int i;23372338strbuf_addstr(&buf, refname);2339 p = buf.buf;2340for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2341while(*p && *p !='/')2342 p++;2343/* tolerate duplicate slashes; see check_refname_format() */2344while(*p =='/')2345 p++;2346}2347 q = buf.buf + buf.len;2348while(flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {2349while(q > p && *q !='/')2350 q--;2351while(q > p && *(q-1) =='/')2352 q--;2353if(q == p)2354break;2355strbuf_setlen(&buf, q - buf.buf);23562357strbuf_reset(&sb);2358strbuf_git_path(&sb,"%s", buf.buf);2359if((flags & REMOVE_EMPTY_PARENTS_REF) &&rmdir(sb.buf))2360 flags &= ~REMOVE_EMPTY_PARENTS_REF;23612362strbuf_reset(&sb);2363files_reflog_path(refs, &sb, buf.buf);2364if((flags & REMOVE_EMPTY_PARENTS_REFLOG) &&rmdir(sb.buf))2365 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;2366}2367strbuf_release(&buf);2368strbuf_release(&sb);2369}23702371/* make sure nobody touched the ref, and unlink */2372static voidprune_ref(struct ref_to_prune *r)2373{2374struct ref_transaction *transaction;2375struct strbuf err = STRBUF_INIT;23762377if(check_refname_format(r->name,0))2378return;23792380 transaction =ref_transaction_begin(&err);2381if(!transaction ||2382ref_transaction_delete(transaction, r->name, r->sha1,2383 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2384ref_transaction_commit(transaction, &err)) {2385ref_transaction_free(transaction);2386error("%s", err.buf);2387strbuf_release(&err);2388return;2389}2390ref_transaction_free(transaction);2391strbuf_release(&err);2392}23932394static voidprune_refs(struct ref_to_prune *r)2395{2396while(r) {2397prune_ref(r);2398 r = r->next;2399}2400}24012402static intfiles_pack_refs(struct ref_store *ref_store,unsigned int flags)2403{2404struct files_ref_store *refs =2405files_downcast(ref_store,0,"pack_refs");2406struct pack_refs_cb_data cbdata;24072408memset(&cbdata,0,sizeof(cbdata));2409 cbdata.flags = flags;24102411lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2412 cbdata.packed_refs =get_packed_refs(refs);24132414do_for_each_entry_in_dir(get_loose_refs(refs),0,2415 pack_if_possible_fn, &cbdata);24162417if(commit_packed_refs(refs))2418die_errno("unable to overwrite old ref-pack file");24192420prune_refs(cbdata.ref_to_prune);2421return0;2422}24232424/*2425 * Rewrite the packed-refs file, omitting any refs listed in2426 * 'refnames'. On error, leave packed-refs unchanged, write an error2427 * message to 'err', and return a nonzero value.2428 *2429 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2430 */2431static intrepack_without_refs(struct files_ref_store *refs,2432struct string_list *refnames,struct strbuf *err)2433{2434struct ref_dir *packed;2435struct string_list_item *refname;2436int ret, needs_repacking =0, removed =0;24372438files_assert_main_repository(refs,"repack_without_refs");2439assert(err);24402441/* Look for a packed ref */2442for_each_string_list_item(refname, refnames) {2443if(get_packed_ref(refs, refname->string)) {2444 needs_repacking =1;2445break;2446}2447}24482449/* Avoid locking if we have nothing to do */2450if(!needs_repacking)2451return0;/* no refname exists in packed refs */24522453if(lock_packed_refs(refs,0)) {2454unable_to_lock_message(files_packed_refs_path(refs), errno, err);2455return-1;2456}2457 packed =get_packed_refs(refs);24582459/* Remove refnames from the cache */2460for_each_string_list_item(refname, refnames)2461if(remove_entry(packed, refname->string) != -1)2462 removed =1;2463if(!removed) {2464/*2465 * All packed entries disappeared while we were2466 * acquiring the lock.2467 */2468rollback_packed_refs(refs);2469return0;2470}24712472/* Write what remains */2473 ret =commit_packed_refs(refs);2474if(ret)2475strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2476strerror(errno));2477return ret;2478}24792480static intfiles_delete_refs(struct ref_store *ref_store,2481struct string_list *refnames,unsigned int flags)2482{2483struct files_ref_store *refs =2484files_downcast(ref_store,0,"delete_refs");2485struct strbuf err = STRBUF_INIT;2486int i, result =0;24872488if(!refnames->nr)2489return0;24902491 result =repack_without_refs(refs, refnames, &err);2492if(result) {2493/*2494 * If we failed to rewrite the packed-refs file, then2495 * it is unsafe to try to remove loose refs, because2496 * doing so might expose an obsolete packed value for2497 * a reference that might even point at an object that2498 * has been garbage collected.2499 */2500if(refnames->nr ==1)2501error(_("could not delete reference%s:%s"),2502 refnames->items[0].string, err.buf);2503else2504error(_("could not delete references:%s"), err.buf);25052506goto out;2507}25082509for(i =0; i < refnames->nr; i++) {2510const char*refname = refnames->items[i].string;25112512if(delete_ref(NULL, refname, NULL, flags))2513 result |=error(_("could not remove reference%s"), refname);2514}25152516out:2517strbuf_release(&err);2518return result;2519}25202521/*2522 * People using contrib's git-new-workdir have .git/logs/refs ->2523 * /some/other/path/.git/logs/refs, and that may live on another device.2524 *2525 * IOW, to avoid cross device rename errors, the temporary renamed log must2526 * live into logs/refs.2527 */2528#define TMP_RENAMED_LOG"refs/.tmp-renamed-log"25292530struct rename_cb {2531const char*tmp_renamed_log;2532int true_errno;2533};25342535static intrename_tmp_log_callback(const char*path,void*cb_data)2536{2537struct rename_cb *cb = cb_data;25382539if(rename(cb->tmp_renamed_log, path)) {2540/*2541 * rename(a, b) when b is an existing directory ought2542 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.2543 * Sheesh. Record the true errno for error reporting,2544 * but report EISDIR to raceproof_create_file() so2545 * that it knows to retry.2546 */2547 cb->true_errno = errno;2548if(errno == ENOTDIR)2549 errno = EISDIR;2550return-1;2551}else{2552return0;2553}2554}25552556static intrename_tmp_log(struct files_ref_store *refs,const char*newrefname)2557{2558struct strbuf path = STRBUF_INIT;2559struct strbuf tmp = STRBUF_INIT;2560struct rename_cb cb;2561int ret;25622563files_reflog_path(refs, &path, newrefname);2564files_reflog_path(refs, &tmp, TMP_RENAMED_LOG);2565 cb.tmp_renamed_log = tmp.buf;2566 ret =raceproof_create_file(path.buf, rename_tmp_log_callback, &cb);2567if(ret) {2568if(errno == EISDIR)2569error("directory not empty:%s", path.buf);2570else2571error("unable to move logfile%sto%s:%s",2572 tmp.buf, path.buf,2573strerror(cb.true_errno));2574}25752576strbuf_release(&path);2577strbuf_release(&tmp);2578return ret;2579}25802581static intfiles_verify_refname_available(struct ref_store *ref_store,2582const char*newname,2583const struct string_list *extras,2584const struct string_list *skip,2585struct strbuf *err)2586{2587struct files_ref_store *refs =2588files_downcast(ref_store,1,"verify_refname_available");2589struct ref_dir *packed_refs =get_packed_refs(refs);2590struct ref_dir *loose_refs =get_loose_refs(refs);25912592if(verify_refname_available_dir(newname, extras, skip,2593 packed_refs, err) ||2594verify_refname_available_dir(newname, extras, skip,2595 loose_refs, err))2596return-1;25972598return0;2599}26002601static intwrite_ref_to_lockfile(struct ref_lock *lock,2602const unsigned char*sha1,struct strbuf *err);2603static intcommit_ref_update(struct files_ref_store *refs,2604struct ref_lock *lock,2605const unsigned char*sha1,const char*logmsg,2606struct strbuf *err);26072608static intfiles_rename_ref(struct ref_store *ref_store,2609const char*oldrefname,const char*newrefname,2610const char*logmsg)2611{2612struct files_ref_store *refs =2613files_downcast(ref_store,0,"rename_ref");2614unsigned char sha1[20], orig_sha1[20];2615int flag =0, logmoved =0;2616struct ref_lock *lock;2617struct stat loginfo;2618struct strbuf sb_oldref = STRBUF_INIT;2619struct strbuf sb_newref = STRBUF_INIT;2620struct strbuf tmp_renamed_log = STRBUF_INIT;2621int log, ret;2622struct strbuf err = STRBUF_INIT;26232624files_reflog_path(refs, &sb_oldref, oldrefname);2625files_reflog_path(refs, &sb_newref, newrefname);2626files_reflog_path(refs, &tmp_renamed_log, TMP_RENAMED_LOG);26272628 log = !lstat(sb_oldref.buf, &loginfo);2629if(log &&S_ISLNK(loginfo.st_mode)) {2630 ret =error("reflog for%sis a symlink", oldrefname);2631goto out;2632}26332634if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2635 orig_sha1, &flag)) {2636 ret =error("refname%snot found", oldrefname);2637goto out;2638}26392640if(flag & REF_ISSYMREF) {2641 ret =error("refname%sis a symbolic ref, renaming it is not supported",2642 oldrefname);2643goto out;2644}2645if(!rename_ref_available(oldrefname, newrefname)) {2646 ret =1;2647goto out;2648}26492650if(log &&rename(sb_oldref.buf, tmp_renamed_log.buf)) {2651 ret =error("unable to move logfile logs/%sto logs/"TMP_RENAMED_LOG":%s",2652 oldrefname,strerror(errno));2653goto out;2654}26552656if(delete_ref(logmsg, oldrefname, orig_sha1, REF_NODEREF)) {2657error("unable to delete old%s", oldrefname);2658goto rollback;2659}26602661/*2662 * Since we are doing a shallow lookup, sha1 is not the2663 * correct value to pass to delete_ref as old_sha1. But that2664 * doesn't matter, because an old_sha1 check wouldn't add to2665 * the safety anyway; we want to delete the reference whatever2666 * its current value.2667 */2668if(!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2669 sha1, NULL) &&2670delete_ref(NULL, newrefname, NULL, REF_NODEREF)) {2671if(errno == EISDIR) {2672struct strbuf path = STRBUF_INIT;2673int result;26742675strbuf_git_path(&path,"%s", newrefname);2676 result =remove_empty_directories(&path);2677strbuf_release(&path);26782679if(result) {2680error("Directory not empty:%s", newrefname);2681goto rollback;2682}2683}else{2684error("unable to delete existing%s", newrefname);2685goto rollback;2686}2687}26882689if(log &&rename_tmp_log(refs, newrefname))2690goto rollback;26912692 logmoved = log;26932694 lock =lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,2695 REF_NODEREF, NULL, &err);2696if(!lock) {2697error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2698strbuf_release(&err);2699goto rollback;2700}2701hashcpy(lock->old_oid.hash, orig_sha1);27022703if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2704commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {2705error("unable to write current sha1 into%s:%s", newrefname, err.buf);2706strbuf_release(&err);2707goto rollback;2708}27092710 ret =0;2711goto out;27122713 rollback:2714 lock =lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,2715 REF_NODEREF, NULL, &err);2716if(!lock) {2717error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2718strbuf_release(&err);2719goto rollbacklog;2720}27212722 flag = log_all_ref_updates;2723 log_all_ref_updates = LOG_REFS_NONE;2724if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2725commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {2726error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2727strbuf_release(&err);2728}2729 log_all_ref_updates = flag;27302731 rollbacklog:2732if(logmoved &&rename(sb_newref.buf, sb_oldref.buf))2733error("unable to restore logfile%sfrom%s:%s",2734 oldrefname, newrefname,strerror(errno));2735if(!logmoved && log &&2736rename(tmp_renamed_log.buf, sb_oldref.buf))2737error("unable to restore logfile%sfrom logs/"TMP_RENAMED_LOG":%s",2738 oldrefname,strerror(errno));2739 ret =1;2740 out:2741strbuf_release(&sb_newref);2742strbuf_release(&sb_oldref);2743strbuf_release(&tmp_renamed_log);27442745return ret;2746}27472748static intclose_ref(struct ref_lock *lock)2749{2750if(close_lock_file(lock->lk))2751return-1;2752return0;2753}27542755static intcommit_ref(struct ref_lock *lock)2756{2757char*path =get_locked_file_path(lock->lk);2758struct stat st;27592760if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2761/*2762 * There is a directory at the path we want to rename2763 * the lockfile to. Hopefully it is empty; try to2764 * delete it.2765 */2766size_t len =strlen(path);2767struct strbuf sb_path = STRBUF_INIT;27682769strbuf_attach(&sb_path, path, len, len);27702771/*2772 * If this fails, commit_lock_file() will also fail2773 * and will report the problem.2774 */2775remove_empty_directories(&sb_path);2776strbuf_release(&sb_path);2777}else{2778free(path);2779}27802781if(commit_lock_file(lock->lk))2782return-1;2783return0;2784}27852786static intopen_or_create_logfile(const char*path,void*cb)2787{2788int*fd = cb;27892790*fd =open(path, O_APPEND | O_WRONLY | O_CREAT,0666);2791return(*fd <0) ? -1:0;2792}27932794/*2795 * Create a reflog for a ref. If force_create = 0, only create the2796 * reflog for certain refs (those for which should_autocreate_reflog2797 * returns non-zero). Otherwise, create it regardless of the reference2798 * name. If the logfile already existed or was created, return 0 and2799 * set *logfd to the file descriptor opened for appending to the file.2800 * If no logfile exists and we decided not to create one, return 0 and2801 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and2802 * return -1.2803 */2804static intlog_ref_setup(struct files_ref_store *refs,2805const char*refname,int force_create,2806int*logfd,struct strbuf *err)2807{2808struct strbuf logfile_sb = STRBUF_INIT;2809char*logfile;28102811files_reflog_path(refs, &logfile_sb, refname);2812 logfile =strbuf_detach(&logfile_sb, NULL);28132814if(force_create ||should_autocreate_reflog(refname)) {2815if(raceproof_create_file(logfile, open_or_create_logfile, logfd)) {2816if(errno == ENOENT)2817strbuf_addf(err,"unable to create directory for '%s': "2818"%s", logfile,strerror(errno));2819else if(errno == EISDIR)2820strbuf_addf(err,"there are still logs under '%s'",2821 logfile);2822else2823strbuf_addf(err,"unable to append to '%s':%s",2824 logfile,strerror(errno));28252826goto error;2827}2828}else{2829*logfd =open(logfile, O_APPEND | O_WRONLY,0666);2830if(*logfd <0) {2831if(errno == ENOENT || errno == EISDIR) {2832/*2833 * The logfile doesn't already exist,2834 * but that is not an error; it only2835 * means that we won't write log2836 * entries to it.2837 */2838;2839}else{2840strbuf_addf(err,"unable to append to '%s':%s",2841 logfile,strerror(errno));2842goto error;2843}2844}2845}28462847if(*logfd >=0)2848adjust_shared_perm(logfile);28492850free(logfile);2851return0;28522853error:2854free(logfile);2855return-1;2856}28572858static intfiles_create_reflog(struct ref_store *ref_store,2859const char*refname,int force_create,2860struct strbuf *err)2861{2862struct files_ref_store *refs =2863files_downcast(ref_store,0,"create_reflog");2864int fd;28652866if(log_ref_setup(refs, refname, force_create, &fd, err))2867return-1;28682869if(fd >=0)2870close(fd);28712872return0;2873}28742875static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2876const unsigned char*new_sha1,2877const char*committer,const char*msg)2878{2879int msglen, written;2880unsigned maxlen, len;2881char*logrec;28822883 msglen = msg ?strlen(msg) :0;2884 maxlen =strlen(committer) + msglen +100;2885 logrec =xmalloc(maxlen);2886 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2887sha1_to_hex(old_sha1),2888sha1_to_hex(new_sha1),2889 committer);2890if(msglen)2891 len +=copy_reflog_msg(logrec + len -1, msg) -1;28922893 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2894free(logrec);2895if(written != len)2896return-1;28972898return0;2899}29002901static intfiles_log_ref_write(struct files_ref_store *refs,2902const char*refname,const unsigned char*old_sha1,2903const unsigned char*new_sha1,const char*msg,2904int flags,struct strbuf *err)2905{2906int logfd, result;29072908if(log_all_ref_updates == LOG_REFS_UNSET)2909 log_all_ref_updates =is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;29102911 result =log_ref_setup(refs, refname,2912 flags & REF_FORCE_CREATE_REFLOG,2913&logfd, err);29142915if(result)2916return result;29172918if(logfd <0)2919return0;2920 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2921git_committer_info(0), msg);2922if(result) {2923struct strbuf sb = STRBUF_INIT;2924int save_errno = errno;29252926files_reflog_path(refs, &sb, refname);2927strbuf_addf(err,"unable to append to '%s':%s",2928 sb.buf,strerror(save_errno));2929strbuf_release(&sb);2930close(logfd);2931return-1;2932}2933if(close(logfd)) {2934struct strbuf sb = STRBUF_INIT;2935int save_errno = errno;29362937files_reflog_path(refs, &sb, refname);2938strbuf_addf(err,"unable to append to '%s':%s",2939 sb.buf,strerror(save_errno));2940strbuf_release(&sb);2941return-1;2942}2943return0;2944}29452946/*2947 * Write sha1 into the open lockfile, then close the lockfile. On2948 * errors, rollback the lockfile, fill in *err and2949 * return -1.2950 */2951static intwrite_ref_to_lockfile(struct ref_lock *lock,2952const unsigned char*sha1,struct strbuf *err)2953{2954static char term ='\n';2955struct object *o;2956int fd;29572958 o =parse_object(sha1);2959if(!o) {2960strbuf_addf(err,2961"trying to write ref '%s' with nonexistent object%s",2962 lock->ref_name,sha1_to_hex(sha1));2963unlock_ref(lock);2964return-1;2965}2966if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2967strbuf_addf(err,2968"trying to write non-commit object%sto branch '%s'",2969sha1_to_hex(sha1), lock->ref_name);2970unlock_ref(lock);2971return-1;2972}2973 fd =get_lock_file_fd(lock->lk);2974if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2975write_in_full(fd, &term,1) !=1||2976close_ref(lock) <0) {2977strbuf_addf(err,2978"couldn't write '%s'",get_lock_file_path(lock->lk));2979unlock_ref(lock);2980return-1;2981}2982return0;2983}29842985/*2986 * Commit a change to a loose reference that has already been written2987 * to the loose reference lockfile. Also update the reflogs if2988 * necessary, using the specified lockmsg (which can be NULL).2989 */2990static intcommit_ref_update(struct files_ref_store *refs,2991struct ref_lock *lock,2992const unsigned char*sha1,const char*logmsg,2993struct strbuf *err)2994{2995files_assert_main_repository(refs,"commit_ref_update");29962997clear_loose_ref_cache(refs);2998if(files_log_ref_write(refs, lock->ref_name,2999 lock->old_oid.hash, sha1,3000 logmsg,0, err)) {3001char*old_msg =strbuf_detach(err, NULL);3002strbuf_addf(err,"cannot update the ref '%s':%s",3003 lock->ref_name, old_msg);3004free(old_msg);3005unlock_ref(lock);3006return-1;3007}30083009if(strcmp(lock->ref_name,"HEAD") !=0) {3010/*3011 * Special hack: If a branch is updated directly and HEAD3012 * points to it (may happen on the remote side of a push3013 * for example) then logically the HEAD reflog should be3014 * updated too.3015 * A generic solution implies reverse symref information,3016 * but finding all symrefs pointing to the given branch3017 * would be rather costly for this rare event (the direct3018 * update of a branch) to be worth it. So let's cheat and3019 * check with HEAD only which should cover 99% of all usage3020 * scenarios (even 100% of the default ones).3021 */3022unsigned char head_sha1[20];3023int head_flag;3024const char*head_ref;30253026 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3027 head_sha1, &head_flag);3028if(head_ref && (head_flag & REF_ISSYMREF) &&3029!strcmp(head_ref, lock->ref_name)) {3030struct strbuf log_err = STRBUF_INIT;3031if(files_log_ref_write(refs,"HEAD",3032 lock->old_oid.hash, sha1,3033 logmsg,0, &log_err)) {3034error("%s", log_err.buf);3035strbuf_release(&log_err);3036}3037}3038}30393040if(commit_ref(lock)) {3041strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3042unlock_ref(lock);3043return-1;3044}30453046unlock_ref(lock);3047return0;3048}30493050static intcreate_ref_symlink(struct ref_lock *lock,const char*target)3051{3052int ret = -1;3053#ifndef NO_SYMLINK_HEAD3054char*ref_path =get_locked_file_path(lock->lk);3055unlink(ref_path);3056 ret =symlink(target, ref_path);3057free(ref_path);30583059if(ret)3060fprintf(stderr,"no symlink - falling back to symbolic ref\n");3061#endif3062return ret;3063}30643065static voidupdate_symref_reflog(struct files_ref_store *refs,3066struct ref_lock *lock,const char*refname,3067const char*target,const char*logmsg)3068{3069struct strbuf err = STRBUF_INIT;3070unsigned char new_sha1[20];3071if(logmsg && !read_ref(target, new_sha1) &&3072files_log_ref_write(refs, refname, lock->old_oid.hash,3073 new_sha1, logmsg,0, &err)) {3074error("%s", err.buf);3075strbuf_release(&err);3076}3077}30783079static intcreate_symref_locked(struct files_ref_store *refs,3080struct ref_lock *lock,const char*refname,3081const char*target,const char*logmsg)3082{3083if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {3084update_symref_reflog(refs, lock, refname, target, logmsg);3085return0;3086}30873088if(!fdopen_lock_file(lock->lk,"w"))3089returnerror("unable to fdopen%s:%s",3090 lock->lk->tempfile.filename.buf,strerror(errno));30913092update_symref_reflog(refs, lock, refname, target, logmsg);30933094/* no error check; commit_ref will check ferror */3095fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);3096if(commit_ref(lock) <0)3097returnerror("unable to write symref for%s:%s", refname,3098strerror(errno));3099return0;3100}31013102static intfiles_create_symref(struct ref_store *ref_store,3103const char*refname,const char*target,3104const char*logmsg)3105{3106struct files_ref_store *refs =3107files_downcast(ref_store,0,"create_symref");3108struct strbuf err = STRBUF_INIT;3109struct ref_lock *lock;3110int ret;31113112 lock =lock_ref_sha1_basic(refs, refname, NULL,3113 NULL, NULL, REF_NODEREF, NULL,3114&err);3115if(!lock) {3116error("%s", err.buf);3117strbuf_release(&err);3118return-1;3119}31203121 ret =create_symref_locked(refs, lock, refname, target, logmsg);3122unlock_ref(lock);3123return ret;3124}31253126intset_worktree_head_symref(const char*gitdir,const char*target,const char*logmsg)3127{3128/*3129 * FIXME: this obviously will not work well for future refs3130 * backends. This function needs to die.3131 */3132struct files_ref_store *refs =3133files_downcast(get_ref_store(NULL),0,"set_head_symref");31343135static struct lock_file head_lock;3136struct ref_lock *lock;3137struct strbuf head_path = STRBUF_INIT;3138const char*head_rel;3139int ret;31403141strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));3142if(hold_lock_file_for_update(&head_lock, head_path.buf,3143 LOCK_NO_DEREF) <0) {3144struct strbuf err = STRBUF_INIT;3145unable_to_lock_message(head_path.buf, errno, &err);3146error("%s", err.buf);3147strbuf_release(&err);3148strbuf_release(&head_path);3149return-1;3150}31513152/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3153 linked trees */3154 head_rel =remove_leading_path(head_path.buf,3155absolute_path(get_git_common_dir()));3156/* to make use of create_symref_locked(), initialize ref_lock */3157 lock =xcalloc(1,sizeof(struct ref_lock));3158 lock->lk = &head_lock;3159 lock->ref_name =xstrdup(head_rel);31603161 ret =create_symref_locked(refs, lock, head_rel, target, logmsg);31623163unlock_ref(lock);/* will free lock */3164strbuf_release(&head_path);3165return ret;3166}31673168static intfiles_reflog_exists(struct ref_store *ref_store,3169const char*refname)3170{3171struct files_ref_store *refs =3172files_downcast(ref_store,0,"reflog_exists");3173struct strbuf sb = STRBUF_INIT;3174struct stat st;3175int ret;31763177files_reflog_path(refs, &sb, refname);3178 ret = !lstat(sb.buf, &st) &&S_ISREG(st.st_mode);3179strbuf_release(&sb);3180return ret;3181}31823183static intfiles_delete_reflog(struct ref_store *ref_store,3184const char*refname)3185{3186struct files_ref_store *refs =3187files_downcast(ref_store,0,"delete_reflog");3188struct strbuf sb = STRBUF_INIT;3189int ret;31903191files_reflog_path(refs, &sb, refname);3192 ret =remove_path(sb.buf);3193strbuf_release(&sb);3194return ret;3195}31963197static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3198{3199struct object_id ooid, noid;3200char*email_end, *message;3201unsigned long timestamp;3202int tz;3203const char*p = sb->buf;32043205/* old SP new SP name <email> SP time TAB msg LF */3206if(!sb->len || sb->buf[sb->len -1] !='\n'||3207parse_oid_hex(p, &ooid, &p) || *p++ !=' '||3208parse_oid_hex(p, &noid, &p) || *p++ !=' '||3209!(email_end =strchr(p,'>')) ||3210 email_end[1] !=' '||3211!(timestamp =strtoul(email_end +2, &message,10)) ||3212!message || message[0] !=' '||3213(message[1] !='+'&& message[1] !='-') ||3214!isdigit(message[2]) || !isdigit(message[3]) ||3215!isdigit(message[4]) || !isdigit(message[5]))3216return0;/* corrupt? */3217 email_end[1] ='\0';3218 tz =strtol(message +1, NULL,10);3219if(message[6] !='\t')3220 message +=6;3221else3222 message +=7;3223returnfn(&ooid, &noid, p, timestamp, tz, message, cb_data);3224}32253226static char*find_beginning_of_line(char*bob,char*scan)3227{3228while(bob < scan && *(--scan) !='\n')3229;/* keep scanning backwards */3230/*3231 * Return either beginning of the buffer, or LF at the end of3232 * the previous line.3233 */3234return scan;3235}32363237static intfiles_for_each_reflog_ent_reverse(struct ref_store *ref_store,3238const char*refname,3239 each_reflog_ent_fn fn,3240void*cb_data)3241{3242struct files_ref_store *refs =3243files_downcast(ref_store,0,"for_each_reflog_ent_reverse");3244struct strbuf sb = STRBUF_INIT;3245FILE*logfp;3246long pos;3247int ret =0, at_tail =1;32483249files_reflog_path(refs, &sb, refname);3250 logfp =fopen(sb.buf,"r");3251strbuf_release(&sb);3252if(!logfp)3253return-1;32543255/* Jump to the end */3256if(fseek(logfp,0, SEEK_END) <0)3257returnerror("cannot seek back reflog for%s:%s",3258 refname,strerror(errno));3259 pos =ftell(logfp);3260while(!ret &&0< pos) {3261int cnt;3262size_t nread;3263char buf[BUFSIZ];3264char*endp, *scanp;32653266/* Fill next block from the end */3267 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3268if(fseek(logfp, pos - cnt, SEEK_SET))3269returnerror("cannot seek back reflog for%s:%s",3270 refname,strerror(errno));3271 nread =fread(buf, cnt,1, logfp);3272if(nread !=1)3273returnerror("cannot read%dbytes from reflog for%s:%s",3274 cnt, refname,strerror(errno));3275 pos -= cnt;32763277 scanp = endp = buf + cnt;3278if(at_tail && scanp[-1] =='\n')3279/* Looking at the final LF at the end of the file */3280 scanp--;3281 at_tail =0;32823283while(buf < scanp) {3284/*3285 * terminating LF of the previous line, or the beginning3286 * of the buffer.3287 */3288char*bp;32893290 bp =find_beginning_of_line(buf, scanp);32913292if(*bp =='\n') {3293/*3294 * The newline is the end of the previous line,3295 * so we know we have complete line starting3296 * at (bp + 1). Prefix it onto any prior data3297 * we collected for the line and process it.3298 */3299strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3300 scanp = bp;3301 endp = bp +1;3302 ret =show_one_reflog_ent(&sb, fn, cb_data);3303strbuf_reset(&sb);3304if(ret)3305break;3306}else if(!pos) {3307/*3308 * We are at the start of the buffer, and the3309 * start of the file; there is no previous3310 * line, and we have everything for this one.3311 * Process it, and we can end the loop.3312 */3313strbuf_splice(&sb,0,0, buf, endp - buf);3314 ret =show_one_reflog_ent(&sb, fn, cb_data);3315strbuf_reset(&sb);3316break;3317}33183319if(bp == buf) {3320/*3321 * We are at the start of the buffer, and there3322 * is more file to read backwards. Which means3323 * we are in the middle of a line. Note that we3324 * may get here even if *bp was a newline; that3325 * just means we are at the exact end of the3326 * previous line, rather than some spot in the3327 * middle.3328 *3329 * Save away what we have to be combined with3330 * the data from the next read.3331 */3332strbuf_splice(&sb,0,0, buf, endp - buf);3333break;3334}3335}33363337}3338if(!ret && sb.len)3339die("BUG: reverse reflog parser had leftover data");33403341fclose(logfp);3342strbuf_release(&sb);3343return ret;3344}33453346static intfiles_for_each_reflog_ent(struct ref_store *ref_store,3347const char*refname,3348 each_reflog_ent_fn fn,void*cb_data)3349{3350struct files_ref_store *refs =3351files_downcast(ref_store,0,"for_each_reflog_ent");3352FILE*logfp;3353struct strbuf sb = STRBUF_INIT;3354int ret =0;33553356files_reflog_path(refs, &sb, refname);3357 logfp =fopen(sb.buf,"r");3358strbuf_release(&sb);3359if(!logfp)3360return-1;33613362while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3363 ret =show_one_reflog_ent(&sb, fn, cb_data);3364fclose(logfp);3365strbuf_release(&sb);3366return ret;3367}33683369struct files_reflog_iterator {3370struct ref_iterator base;33713372struct dir_iterator *dir_iterator;3373struct object_id oid;3374};33753376static intfiles_reflog_iterator_advance(struct ref_iterator *ref_iterator)3377{3378struct files_reflog_iterator *iter =3379(struct files_reflog_iterator *)ref_iterator;3380struct dir_iterator *diter = iter->dir_iterator;3381int ok;33823383while((ok =dir_iterator_advance(diter)) == ITER_OK) {3384int flags;33853386if(!S_ISREG(diter->st.st_mode))3387continue;3388if(diter->basename[0] =='.')3389continue;3390if(ends_with(diter->basename,".lock"))3391continue;33923393if(read_ref_full(diter->relative_path,0,3394 iter->oid.hash, &flags)) {3395error("bad ref for%s", diter->path.buf);3396continue;3397}33983399 iter->base.refname = diter->relative_path;3400 iter->base.oid = &iter->oid;3401 iter->base.flags = flags;3402return ITER_OK;3403}34043405 iter->dir_iterator = NULL;3406if(ref_iterator_abort(ref_iterator) == ITER_ERROR)3407 ok = ITER_ERROR;3408return ok;3409}34103411static intfiles_reflog_iterator_peel(struct ref_iterator *ref_iterator,3412struct object_id *peeled)3413{3414die("BUG: ref_iterator_peel() called for reflog_iterator");3415}34163417static intfiles_reflog_iterator_abort(struct ref_iterator *ref_iterator)3418{3419struct files_reflog_iterator *iter =3420(struct files_reflog_iterator *)ref_iterator;3421int ok = ITER_DONE;34223423if(iter->dir_iterator)3424 ok =dir_iterator_abort(iter->dir_iterator);34253426base_ref_iterator_free(ref_iterator);3427return ok;3428}34293430static struct ref_iterator_vtable files_reflog_iterator_vtable = {3431 files_reflog_iterator_advance,3432 files_reflog_iterator_peel,3433 files_reflog_iterator_abort3434};34353436static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)3437{3438struct files_ref_store *refs =3439files_downcast(ref_store,0,"reflog_iterator_begin");3440struct files_reflog_iterator *iter =xcalloc(1,sizeof(*iter));3441struct ref_iterator *ref_iterator = &iter->base;3442struct strbuf sb = STRBUF_INIT;34433444base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3445files_reflog_path(refs, &sb, NULL);3446 iter->dir_iterator =dir_iterator_begin(sb.buf);3447strbuf_release(&sb);3448return ref_iterator;3449}34503451static intref_update_reject_duplicates(struct string_list *refnames,3452struct strbuf *err)3453{3454int i, n = refnames->nr;34553456assert(err);34573458for(i =1; i < n; i++)3459if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3460strbuf_addf(err,3461"multiple updates for ref '%s' not allowed.",3462 refnames->items[i].string);3463return1;3464}3465return0;3466}34673468/*3469 * If update is a direct update of head_ref (the reference pointed to3470 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3471 */3472static intsplit_head_update(struct ref_update *update,3473struct ref_transaction *transaction,3474const char*head_ref,3475struct string_list *affected_refnames,3476struct strbuf *err)3477{3478struct string_list_item *item;3479struct ref_update *new_update;34803481if((update->flags & REF_LOG_ONLY) ||3482(update->flags & REF_ISPRUNING) ||3483(update->flags & REF_UPDATE_VIA_HEAD))3484return0;34853486if(strcmp(update->refname, head_ref))3487return0;34883489/*3490 * First make sure that HEAD is not already in the3491 * transaction. This insertion is O(N) in the transaction3492 * size, but it happens at most once per transaction.3493 */3494 item =string_list_insert(affected_refnames,"HEAD");3495if(item->util) {3496/* An entry already existed */3497strbuf_addf(err,3498"multiple updates for 'HEAD' (including one "3499"via its referent '%s') are not allowed",3500 update->refname);3501return TRANSACTION_NAME_CONFLICT;3502}35033504 new_update =ref_transaction_add_update(3505 transaction,"HEAD",3506 update->flags | REF_LOG_ONLY | REF_NODEREF,3507 update->new_sha1, update->old_sha1,3508 update->msg);35093510 item->util = new_update;35113512return0;3513}35143515/*3516 * update is for a symref that points at referent and doesn't have3517 * REF_NODEREF set. Split it into two updates:3518 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3519 * - A new, separate update for the referent reference3520 * Note that the new update will itself be subject to splitting when3521 * the iteration gets to it.3522 */3523static intsplit_symref_update(struct files_ref_store *refs,3524struct ref_update *update,3525const char*referent,3526struct ref_transaction *transaction,3527struct string_list *affected_refnames,3528struct strbuf *err)3529{3530struct string_list_item *item;3531struct ref_update *new_update;3532unsigned int new_flags;35333534/*3535 * First make sure that referent is not already in the3536 * transaction. This insertion is O(N) in the transaction3537 * size, but it happens at most once per symref in a3538 * transaction.3539 */3540 item =string_list_insert(affected_refnames, referent);3541if(item->util) {3542/* An entry already existed */3543strbuf_addf(err,3544"multiple updates for '%s' (including one "3545"via symref '%s') are not allowed",3546 referent, update->refname);3547return TRANSACTION_NAME_CONFLICT;3548}35493550 new_flags = update->flags;3551if(!strcmp(update->refname,"HEAD")) {3552/*3553 * Record that the new update came via HEAD, so that3554 * when we process it, split_head_update() doesn't try3555 * to add another reflog update for HEAD. Note that3556 * this bit will be propagated if the new_update3557 * itself needs to be split.3558 */3559 new_flags |= REF_UPDATE_VIA_HEAD;3560}35613562 new_update =ref_transaction_add_update(3563 transaction, referent, new_flags,3564 update->new_sha1, update->old_sha1,3565 update->msg);35663567 new_update->parent_update = update;35683569/*3570 * Change the symbolic ref update to log only. Also, it3571 * doesn't need to check its old SHA-1 value, as that will be3572 * done when new_update is processed.3573 */3574 update->flags |= REF_LOG_ONLY | REF_NODEREF;3575 update->flags &= ~REF_HAVE_OLD;35763577 item->util = new_update;35783579return0;3580}35813582/*3583 * Return the refname under which update was originally requested.3584 */3585static const char*original_update_refname(struct ref_update *update)3586{3587while(update->parent_update)3588 update = update->parent_update;35893590return update->refname;3591}35923593/*3594 * Check whether the REF_HAVE_OLD and old_oid values stored in update3595 * are consistent with oid, which is the reference's current value. If3596 * everything is OK, return 0; otherwise, write an error message to3597 * err and return -1.3598 */3599static intcheck_old_oid(struct ref_update *update,struct object_id *oid,3600struct strbuf *err)3601{3602if(!(update->flags & REF_HAVE_OLD) ||3603!hashcmp(oid->hash, update->old_sha1))3604return0;36053606if(is_null_sha1(update->old_sha1))3607strbuf_addf(err,"cannot lock ref '%s': "3608"reference already exists",3609original_update_refname(update));3610else if(is_null_oid(oid))3611strbuf_addf(err,"cannot lock ref '%s': "3612"reference is missing but expected%s",3613original_update_refname(update),3614sha1_to_hex(update->old_sha1));3615else3616strbuf_addf(err,"cannot lock ref '%s': "3617"is at%sbut expected%s",3618original_update_refname(update),3619oid_to_hex(oid),3620sha1_to_hex(update->old_sha1));36213622return-1;3623}36243625/*3626 * Prepare for carrying out update:3627 * - Lock the reference referred to by update.3628 * - Read the reference under lock.3629 * - Check that its old SHA-1 value (if specified) is correct, and in3630 * any case record it in update->lock->old_oid for later use when3631 * writing the reflog.3632 * - If it is a symref update without REF_NODEREF, split it up into a3633 * REF_LOG_ONLY update of the symref and add a separate update for3634 * the referent to transaction.3635 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3636 * update of HEAD.3637 */3638static intlock_ref_for_update(struct files_ref_store *refs,3639struct ref_update *update,3640struct ref_transaction *transaction,3641const char*head_ref,3642struct string_list *affected_refnames,3643struct strbuf *err)3644{3645struct strbuf referent = STRBUF_INIT;3646int mustexist = (update->flags & REF_HAVE_OLD) &&3647!is_null_sha1(update->old_sha1);3648int ret;3649struct ref_lock *lock;36503651files_assert_main_repository(refs,"lock_ref_for_update");36523653if((update->flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3654 update->flags |= REF_DELETING;36553656if(head_ref) {3657 ret =split_head_update(update, transaction, head_ref,3658 affected_refnames, err);3659if(ret)3660return ret;3661}36623663 ret =lock_raw_ref(refs, update->refname, mustexist,3664 affected_refnames, NULL,3665&lock, &referent,3666&update->type, err);3667if(ret) {3668char*reason;36693670 reason =strbuf_detach(err, NULL);3671strbuf_addf(err,"cannot lock ref '%s':%s",3672original_update_refname(update), reason);3673free(reason);3674return ret;3675}36763677 update->backend_data = lock;36783679if(update->type & REF_ISSYMREF) {3680if(update->flags & REF_NODEREF) {3681/*3682 * We won't be reading the referent as part of3683 * the transaction, so we have to read it here3684 * to record and possibly check old_sha1:3685 */3686if(read_ref_full(referent.buf,0,3687 lock->old_oid.hash, NULL)) {3688if(update->flags & REF_HAVE_OLD) {3689strbuf_addf(err,"cannot lock ref '%s': "3690"error reading reference",3691original_update_refname(update));3692return-1;3693}3694}else if(check_old_oid(update, &lock->old_oid, err)) {3695return TRANSACTION_GENERIC_ERROR;3696}3697}else{3698/*3699 * Create a new update for the reference this3700 * symref is pointing at. Also, we will record3701 * and verify old_sha1 for this update as part3702 * of processing the split-off update, so we3703 * don't have to do it here.3704 */3705 ret =split_symref_update(refs, update,3706 referent.buf, transaction,3707 affected_refnames, err);3708if(ret)3709return ret;3710}3711}else{3712struct ref_update *parent_update;37133714if(check_old_oid(update, &lock->old_oid, err))3715return TRANSACTION_GENERIC_ERROR;37163717/*3718 * If this update is happening indirectly because of a3719 * symref update, record the old SHA-1 in the parent3720 * update:3721 */3722for(parent_update = update->parent_update;3723 parent_update;3724 parent_update = parent_update->parent_update) {3725struct ref_lock *parent_lock = parent_update->backend_data;3726oidcpy(&parent_lock->old_oid, &lock->old_oid);3727}3728}37293730if((update->flags & REF_HAVE_NEW) &&3731!(update->flags & REF_DELETING) &&3732!(update->flags & REF_LOG_ONLY)) {3733if(!(update->type & REF_ISSYMREF) &&3734!hashcmp(lock->old_oid.hash, update->new_sha1)) {3735/*3736 * The reference already has the desired3737 * value, so we don't need to write it.3738 */3739}else if(write_ref_to_lockfile(lock, update->new_sha1,3740 err)) {3741char*write_err =strbuf_detach(err, NULL);37423743/*3744 * The lock was freed upon failure of3745 * write_ref_to_lockfile():3746 */3747 update->backend_data = NULL;3748strbuf_addf(err,3749"cannot update ref '%s':%s",3750 update->refname, write_err);3751free(write_err);3752return TRANSACTION_GENERIC_ERROR;3753}else{3754 update->flags |= REF_NEEDS_COMMIT;3755}3756}3757if(!(update->flags & REF_NEEDS_COMMIT)) {3758/*3759 * We didn't call write_ref_to_lockfile(), so3760 * the lockfile is still open. Close it to3761 * free up the file descriptor:3762 */3763if(close_ref(lock)) {3764strbuf_addf(err,"couldn't close '%s.lock'",3765 update->refname);3766return TRANSACTION_GENERIC_ERROR;3767}3768}3769return0;3770}37713772static intfiles_transaction_commit(struct ref_store *ref_store,3773struct ref_transaction *transaction,3774struct strbuf *err)3775{3776struct files_ref_store *refs =3777files_downcast(ref_store,0,"ref_transaction_commit");3778int ret =0, i;3779struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3780struct string_list_item *ref_to_delete;3781struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3782char*head_ref = NULL;3783int head_type;3784struct object_id head_oid;3785struct strbuf sb = STRBUF_INIT;37863787assert(err);37883789if(transaction->state != REF_TRANSACTION_OPEN)3790die("BUG: commit called for transaction that is not open");37913792if(!transaction->nr) {3793 transaction->state = REF_TRANSACTION_CLOSED;3794return0;3795}37963797/*3798 * Fail if a refname appears more than once in the3799 * transaction. (If we end up splitting up any updates using3800 * split_symref_update() or split_head_update(), those3801 * functions will check that the new updates don't have the3802 * same refname as any existing ones.)3803 */3804for(i =0; i < transaction->nr; i++) {3805struct ref_update *update = transaction->updates[i];3806struct string_list_item *item =3807string_list_append(&affected_refnames, update->refname);38083809/*3810 * We store a pointer to update in item->util, but at3811 * the moment we never use the value of this field3812 * except to check whether it is non-NULL.3813 */3814 item->util = update;3815}3816string_list_sort(&affected_refnames);3817if(ref_update_reject_duplicates(&affected_refnames, err)) {3818 ret = TRANSACTION_GENERIC_ERROR;3819goto cleanup;3820}38213822/*3823 * Special hack: If a branch is updated directly and HEAD3824 * points to it (may happen on the remote side of a push3825 * for example) then logically the HEAD reflog should be3826 * updated too.3827 *3828 * A generic solution would require reverse symref lookups,3829 * but finding all symrefs pointing to a given branch would be3830 * rather costly for this rare event (the direct update of a3831 * branch) to be worth it. So let's cheat and check with HEAD3832 * only, which should cover 99% of all usage scenarios (even3833 * 100% of the default ones).3834 *3835 * So if HEAD is a symbolic reference, then record the name of3836 * the reference that it points to. If we see an update of3837 * head_ref within the transaction, then split_head_update()3838 * arranges for the reflog of HEAD to be updated, too.3839 */3840 head_ref =resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3841 head_oid.hash, &head_type);38423843if(head_ref && !(head_type & REF_ISSYMREF)) {3844free(head_ref);3845 head_ref = NULL;3846}38473848/*3849 * Acquire all locks, verify old values if provided, check3850 * that new values are valid, and write new values to the3851 * lockfiles, ready to be activated. Only keep one lockfile3852 * open at a time to avoid running out of file descriptors.3853 */3854for(i =0; i < transaction->nr; i++) {3855struct ref_update *update = transaction->updates[i];38563857 ret =lock_ref_for_update(refs, update, transaction,3858 head_ref, &affected_refnames, err);3859if(ret)3860goto cleanup;3861}38623863/* Perform updates first so live commits remain referenced */3864for(i =0; i < transaction->nr; i++) {3865struct ref_update *update = transaction->updates[i];3866struct ref_lock *lock = update->backend_data;38673868if(update->flags & REF_NEEDS_COMMIT ||3869 update->flags & REF_LOG_ONLY) {3870if(files_log_ref_write(refs,3871 lock->ref_name,3872 lock->old_oid.hash,3873 update->new_sha1,3874 update->msg, update->flags,3875 err)) {3876char*old_msg =strbuf_detach(err, NULL);38773878strbuf_addf(err,"cannot update the ref '%s':%s",3879 lock->ref_name, old_msg);3880free(old_msg);3881unlock_ref(lock);3882 update->backend_data = NULL;3883 ret = TRANSACTION_GENERIC_ERROR;3884goto cleanup;3885}3886}3887if(update->flags & REF_NEEDS_COMMIT) {3888clear_loose_ref_cache(refs);3889if(commit_ref(lock)) {3890strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3891unlock_ref(lock);3892 update->backend_data = NULL;3893 ret = TRANSACTION_GENERIC_ERROR;3894goto cleanup;3895}3896}3897}3898/* Perform deletes now that updates are safely completed */3899for(i =0; i < transaction->nr; i++) {3900struct ref_update *update = transaction->updates[i];3901struct ref_lock *lock = update->backend_data;39023903if(update->flags & REF_DELETING &&3904!(update->flags & REF_LOG_ONLY)) {3905if(!(update->type & REF_ISPACKED) ||3906 update->type & REF_ISSYMREF) {3907/* It is a loose reference. */3908strbuf_reset(&sb);3909strbuf_git_path(&sb,"%s", lock->ref_name);3910if(unlink_or_msg(sb.buf, err)) {3911 ret = TRANSACTION_GENERIC_ERROR;3912goto cleanup;3913}3914 update->flags |= REF_DELETED_LOOSE;3915}39163917if(!(update->flags & REF_ISPRUNING))3918string_list_append(&refs_to_delete,3919 lock->ref_name);3920}3921}39223923if(repack_without_refs(refs, &refs_to_delete, err)) {3924 ret = TRANSACTION_GENERIC_ERROR;3925goto cleanup;3926}39273928/* Delete the reflogs of any references that were deleted: */3929for_each_string_list_item(ref_to_delete, &refs_to_delete) {3930strbuf_reset(&sb);3931files_reflog_path(refs, &sb, ref_to_delete->string);3932if(!unlink_or_warn(sb.buf))3933try_remove_empty_parents(refs, ref_to_delete->string,3934 REMOVE_EMPTY_PARENTS_REFLOG);3935}39363937clear_loose_ref_cache(refs);39383939cleanup:3940strbuf_release(&sb);3941 transaction->state = REF_TRANSACTION_CLOSED;39423943for(i =0; i < transaction->nr; i++) {3944struct ref_update *update = transaction->updates[i];3945struct ref_lock *lock = update->backend_data;39463947if(lock)3948unlock_ref(lock);39493950if(update->flags & REF_DELETED_LOOSE) {3951/*3952 * The loose reference was deleted. Delete any3953 * empty parent directories. (Note that this3954 * can only work because we have already3955 * removed the lockfile.)3956 */3957try_remove_empty_parents(refs, update->refname,3958 REMOVE_EMPTY_PARENTS_REF);3959}3960}39613962string_list_clear(&refs_to_delete,0);3963free(head_ref);3964string_list_clear(&affected_refnames,0);39653966return ret;3967}39683969static intref_present(const char*refname,3970const struct object_id *oid,int flags,void*cb_data)3971{3972struct string_list *affected_refnames = cb_data;39733974returnstring_list_has_string(affected_refnames, refname);3975}39763977static intfiles_initial_transaction_commit(struct ref_store *ref_store,3978struct ref_transaction *transaction,3979struct strbuf *err)3980{3981struct files_ref_store *refs =3982files_downcast(ref_store,0,"initial_ref_transaction_commit");3983int ret =0, i;3984struct string_list affected_refnames = STRING_LIST_INIT_NODUP;39853986assert(err);39873988if(transaction->state != REF_TRANSACTION_OPEN)3989die("BUG: commit called for transaction that is not open");39903991/* Fail if a refname appears more than once in the transaction: */3992for(i =0; i < transaction->nr; i++)3993string_list_append(&affected_refnames,3994 transaction->updates[i]->refname);3995string_list_sort(&affected_refnames);3996if(ref_update_reject_duplicates(&affected_refnames, err)) {3997 ret = TRANSACTION_GENERIC_ERROR;3998goto cleanup;3999}40004001/*4002 * It's really undefined to call this function in an active4003 * repository or when there are existing references: we are4004 * only locking and changing packed-refs, so (1) any4005 * simultaneous processes might try to change a reference at4006 * the same time we do, and (2) any existing loose versions of4007 * the references that we are setting would have precedence4008 * over our values. But some remote helpers create the remote4009 * "HEAD" and "master" branches before calling this function,4010 * so here we really only check that none of the references4011 * that we are creating already exists.4012 */4013if(for_each_rawref(ref_present, &affected_refnames))4014die("BUG: initial ref transaction called with existing refs");40154016for(i =0; i < transaction->nr; i++) {4017struct ref_update *update = transaction->updates[i];40184019if((update->flags & REF_HAVE_OLD) &&4020!is_null_sha1(update->old_sha1))4021die("BUG: initial ref transaction with old_sha1 set");4022if(verify_refname_available(update->refname,4023&affected_refnames, NULL,4024 err)) {4025 ret = TRANSACTION_NAME_CONFLICT;4026goto cleanup;4027}4028}40294030if(lock_packed_refs(refs,0)) {4031strbuf_addf(err,"unable to lock packed-refs file:%s",4032strerror(errno));4033 ret = TRANSACTION_GENERIC_ERROR;4034goto cleanup;4035}40364037for(i =0; i < transaction->nr; i++) {4038struct ref_update *update = transaction->updates[i];40394040if((update->flags & REF_HAVE_NEW) &&4041!is_null_sha1(update->new_sha1))4042add_packed_ref(refs, update->refname, update->new_sha1);4043}40444045if(commit_packed_refs(refs)) {4046strbuf_addf(err,"unable to commit packed-refs file:%s",4047strerror(errno));4048 ret = TRANSACTION_GENERIC_ERROR;4049goto cleanup;4050}40514052cleanup:4053 transaction->state = REF_TRANSACTION_CLOSED;4054string_list_clear(&affected_refnames,0);4055return ret;4056}40574058struct expire_reflog_cb {4059unsigned int flags;4060 reflog_expiry_should_prune_fn *should_prune_fn;4061void*policy_cb;4062FILE*newlog;4063struct object_id last_kept_oid;4064};40654066static intexpire_reflog_ent(struct object_id *ooid,struct object_id *noid,4067const char*email,unsigned long timestamp,int tz,4068const char*message,void*cb_data)4069{4070struct expire_reflog_cb *cb = cb_data;4071struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;40724073if(cb->flags & EXPIRE_REFLOGS_REWRITE)4074 ooid = &cb->last_kept_oid;40754076if((*cb->should_prune_fn)(ooid->hash, noid->hash, email, timestamp, tz,4077 message, policy_cb)) {4078if(!cb->newlog)4079printf("would prune%s", message);4080else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)4081printf("prune%s", message);4082}else{4083if(cb->newlog) {4084fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",4085oid_to_hex(ooid),oid_to_hex(noid),4086 email, timestamp, tz, message);4087oidcpy(&cb->last_kept_oid, noid);4088}4089if(cb->flags & EXPIRE_REFLOGS_VERBOSE)4090printf("keep%s", message);4091}4092return0;4093}40944095static intfiles_reflog_expire(struct ref_store *ref_store,4096const char*refname,const unsigned char*sha1,4097unsigned int flags,4098 reflog_expiry_prepare_fn prepare_fn,4099 reflog_expiry_should_prune_fn should_prune_fn,4100 reflog_expiry_cleanup_fn cleanup_fn,4101void*policy_cb_data)4102{4103struct files_ref_store *refs =4104files_downcast(ref_store,0,"reflog_expire");4105static struct lock_file reflog_lock;4106struct expire_reflog_cb cb;4107struct ref_lock *lock;4108struct strbuf log_file_sb = STRBUF_INIT;4109char*log_file;4110int status =0;4111int type;4112struct strbuf err = STRBUF_INIT;41134114memset(&cb,0,sizeof(cb));4115 cb.flags = flags;4116 cb.policy_cb = policy_cb_data;4117 cb.should_prune_fn = should_prune_fn;41184119/*4120 * The reflog file is locked by holding the lock on the4121 * reference itself, plus we might need to update the4122 * reference if --updateref was specified:4123 */4124 lock =lock_ref_sha1_basic(refs, refname, sha1,4125 NULL, NULL, REF_NODEREF,4126&type, &err);4127if(!lock) {4128error("cannot lock ref '%s':%s", refname, err.buf);4129strbuf_release(&err);4130return-1;4131}4132if(!reflog_exists(refname)) {4133unlock_ref(lock);4134return0;4135}41364137files_reflog_path(refs, &log_file_sb, refname);4138 log_file =strbuf_detach(&log_file_sb, NULL);4139if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4140/*4141 * Even though holding $GIT_DIR/logs/$reflog.lock has4142 * no locking implications, we use the lock_file4143 * machinery here anyway because it does a lot of the4144 * work we need, including cleaning up if the program4145 * exits unexpectedly.4146 */4147if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4148struct strbuf err = STRBUF_INIT;4149unable_to_lock_message(log_file, errno, &err);4150error("%s", err.buf);4151strbuf_release(&err);4152goto failure;4153}4154 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4155if(!cb.newlog) {4156error("cannot fdopen%s(%s)",4157get_lock_file_path(&reflog_lock),strerror(errno));4158goto failure;4159}4160}41614162(*prepare_fn)(refname, sha1, cb.policy_cb);4163for_each_reflog_ent(refname, expire_reflog_ent, &cb);4164(*cleanup_fn)(cb.policy_cb);41654166if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4167/*4168 * It doesn't make sense to adjust a reference pointed4169 * to by a symbolic ref based on expiring entries in4170 * the symbolic reference's reflog. Nor can we update4171 * a reference if there are no remaining reflog4172 * entries.4173 */4174int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4175!(type & REF_ISSYMREF) &&4176!is_null_oid(&cb.last_kept_oid);41774178if(close_lock_file(&reflog_lock)) {4179 status |=error("couldn't write%s:%s", log_file,4180strerror(errno));4181}else if(update &&4182(write_in_full(get_lock_file_fd(lock->lk),4183oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||4184write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||4185close_ref(lock) <0)) {4186 status |=error("couldn't write%s",4187get_lock_file_path(lock->lk));4188rollback_lock_file(&reflog_lock);4189}else if(commit_lock_file(&reflog_lock)) {4190 status |=error("unable to write reflog '%s' (%s)",4191 log_file,strerror(errno));4192}else if(update &&commit_ref(lock)) {4193 status |=error("couldn't set%s", lock->ref_name);4194}4195}4196free(log_file);4197unlock_ref(lock);4198return status;41994200 failure:4201rollback_lock_file(&reflog_lock);4202free(log_file);4203unlock_ref(lock);4204return-1;4205}42064207static intfiles_init_db(struct ref_store *ref_store,struct strbuf *err)4208{4209struct strbuf sb = STRBUF_INIT;42104211/* Check validity (but we don't need the result): */4212files_downcast(ref_store,0,"init_db");42134214/*4215 * Create .git/refs/{heads,tags}4216 */4217strbuf_git_path(&sb,"refs/heads");4218safe_create_dir(sb.buf,1);42194220strbuf_reset(&sb);4221strbuf_git_path(&sb,"refs/tags");4222safe_create_dir(sb.buf,1);42234224strbuf_release(&sb);4225return0;4226}42274228struct ref_storage_be refs_be_files = {4229 NULL,4230"files",4231 files_ref_store_create,4232 files_init_db,4233 files_transaction_commit,4234 files_initial_transaction_commit,42354236 files_pack_refs,4237 files_peel_ref,4238 files_create_symref,4239 files_delete_refs,4240 files_rename_ref,42414242 files_ref_iterator_begin,4243 files_read_raw_ref,4244 files_verify_refname_available,42454246 files_reflog_iterator_begin,4247 files_for_each_reflog_ent,4248 files_for_each_reflog_ent_reverse,4249 files_reflog_exists,4250 files_create_reflog,4251 files_delete_reflog,4252 files_reflog_expire4253};