1#include"../cache.h" 2#include"../refs.h" 3#include"refs-internal.h" 4#include"../iterator.h" 5#include"../dir-iterator.h" 6#include"../lockfile.h" 7#include"../object.h" 8#include"../dir.h" 9 10struct ref_lock { 11char*ref_name; 12struct lock_file *lk; 13struct object_id old_oid; 14}; 15 16struct ref_entry; 17 18/* 19 * Information used (along with the information in ref_entry) to 20 * describe a single cached reference. This data structure only 21 * occurs embedded in a union in struct ref_entry, and only when 22 * (ref_entry->flag & REF_DIR) is zero. 23 */ 24struct ref_value { 25/* 26 * The name of the object to which this reference resolves 27 * (which may be a tag object). If REF_ISBROKEN, this is 28 * null. If REF_ISSYMREF, then this is the name of the object 29 * referred to by the last reference in the symlink chain. 30 */ 31struct object_id oid; 32 33/* 34 * If REF_KNOWS_PEELED, then this field holds the peeled value 35 * of this reference, or null if the reference is known not to 36 * be peelable. See the documentation for peel_ref() for an 37 * exact definition of "peelable". 38 */ 39struct object_id peeled; 40}; 41 42struct files_ref_store; 43 44/* 45 * Information used (along with the information in ref_entry) to 46 * describe a level in the hierarchy of references. This data 47 * structure only occurs embedded in a union in struct ref_entry, and 48 * only when (ref_entry.flag & REF_DIR) is set. In that case, 49 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 50 * in the directory have already been read: 51 * 52 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 53 * or packed references, already read. 54 * 55 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 56 * references that hasn't been read yet (nor has any of its 57 * subdirectories). 58 * 59 * Entries within a directory are stored within a growable array of 60 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 61 * sorted are sorted by their component name in strcmp() order and the 62 * remaining entries are unsorted. 63 * 64 * Loose references are read lazily, one directory at a time. When a 65 * directory of loose references is read, then all of the references 66 * in that directory are stored, and REF_INCOMPLETE stubs are created 67 * for any subdirectories, but the subdirectories themselves are not 68 * read. The reading is triggered by get_ref_dir(). 69 */ 70struct ref_dir { 71int nr, alloc; 72 73/* 74 * Entries with index 0 <= i < sorted are sorted by name. New 75 * entries are appended to the list unsorted, and are sorted 76 * only when required; thus we avoid the need to sort the list 77 * after the addition of every reference. 78 */ 79int sorted; 80 81/* A pointer to the files_ref_store that contains this ref_dir. */ 82struct files_ref_store *ref_store; 83 84struct ref_entry **entries; 85}; 86 87/* 88 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 89 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 90 * public values; see refs.h. 91 */ 92 93/* 94 * The field ref_entry->u.value.peeled of this value entry contains 95 * the correct peeled value for the reference, which might be 96 * null_sha1 if the reference is not a tag or if it is broken. 97 */ 98#define REF_KNOWS_PEELED 0x10 99 100/* ref_entry represents a directory of references */ 101#define REF_DIR 0x20 102 103/* 104 * Entry has not yet been read from disk (used only for REF_DIR 105 * entries representing loose references) 106 */ 107#define REF_INCOMPLETE 0x40 108 109/* 110 * A ref_entry represents either a reference or a "subdirectory" of 111 * references. 112 * 113 * Each directory in the reference namespace is represented by a 114 * ref_entry with (flags & REF_DIR) set and containing a subdir member 115 * that holds the entries in that directory that have been read so 116 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 117 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 118 * used for loose reference directories. 119 * 120 * References are represented by a ref_entry with (flags & REF_DIR) 121 * unset and a value member that describes the reference's value. The 122 * flag member is at the ref_entry level, but it is also needed to 123 * interpret the contents of the value field (in other words, a 124 * ref_value object is not very much use without the enclosing 125 * ref_entry). 126 * 127 * Reference names cannot end with slash and directories' names are 128 * always stored with a trailing slash (except for the top-level 129 * directory, which is always denoted by ""). This has two nice 130 * consequences: (1) when the entries in each subdir are sorted 131 * lexicographically by name (as they usually are), the references in 132 * a whole tree can be generated in lexicographic order by traversing 133 * the tree in left-to-right, depth-first order; (2) the names of 134 * references and subdirectories cannot conflict, and therefore the 135 * presence of an empty subdirectory does not block the creation of a 136 * similarly-named reference. (The fact that reference names with the 137 * same leading components can conflict *with each other* is a 138 * separate issue that is regulated by verify_refname_available().) 139 * 140 * Please note that the name field contains the fully-qualified 141 * reference (or subdirectory) name. Space could be saved by only 142 * storing the relative names. But that would require the full names 143 * to be generated on the fly when iterating in do_for_each_ref(), and 144 * would break callback functions, who have always been able to assume 145 * that the name strings that they are passed will not be freed during 146 * the iteration. 147 */ 148struct ref_entry { 149unsigned char flag;/* ISSYMREF? ISPACKED? */ 150union{ 151struct ref_value value;/* if not (flags&REF_DIR) */ 152struct ref_dir subdir;/* if (flags&REF_DIR) */ 153} u; 154/* 155 * The full name of the reference (e.g., "refs/heads/master") 156 * or the full name of the directory with a trailing slash 157 * (e.g., "refs/heads/"): 158 */ 159char name[FLEX_ARRAY]; 160}; 161 162static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 163static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len); 164static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 165const char*dirname,size_t len, 166int incomplete); 167static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry); 168 169static struct ref_dir *get_ref_dir(struct ref_entry *entry) 170{ 171struct ref_dir *dir; 172assert(entry->flag & REF_DIR); 173 dir = &entry->u.subdir; 174if(entry->flag & REF_INCOMPLETE) { 175read_loose_refs(entry->name, dir); 176 177/* 178 * Manually add refs/bisect, which, being 179 * per-worktree, might not appear in the directory 180 * listing for refs/ in the main repo. 181 */ 182if(!strcmp(entry->name,"refs/")) { 183int pos =search_ref_dir(dir,"refs/bisect/",12); 184if(pos <0) { 185struct ref_entry *child_entry; 186 child_entry =create_dir_entry(dir->ref_store, 187"refs/bisect/", 18812,1); 189add_entry_to_dir(dir, child_entry); 190read_loose_refs("refs/bisect", 191&child_entry->u.subdir); 192} 193} 194 entry->flag &= ~REF_INCOMPLETE; 195} 196return dir; 197} 198 199static struct ref_entry *create_ref_entry(const char*refname, 200const unsigned char*sha1,int flag, 201int check_name) 202{ 203struct ref_entry *ref; 204 205if(check_name && 206check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 207die("Reference has invalid format: '%s'", refname); 208FLEX_ALLOC_STR(ref, name, refname); 209hashcpy(ref->u.value.oid.hash, sha1); 210oidclr(&ref->u.value.peeled); 211 ref->flag = flag; 212return ref; 213} 214 215static voidclear_ref_dir(struct ref_dir *dir); 216 217static voidfree_ref_entry(struct ref_entry *entry) 218{ 219if(entry->flag & REF_DIR) { 220/* 221 * Do not use get_ref_dir() here, as that might 222 * trigger the reading of loose refs. 223 */ 224clear_ref_dir(&entry->u.subdir); 225} 226free(entry); 227} 228 229/* 230 * Add a ref_entry to the end of dir (unsorted). Entry is always 231 * stored directly in dir; no recursion into subdirectories is 232 * done. 233 */ 234static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 235{ 236ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 237 dir->entries[dir->nr++] = entry; 238/* optimize for the case that entries are added in order */ 239if(dir->nr ==1|| 240(dir->nr == dir->sorted +1&& 241strcmp(dir->entries[dir->nr -2]->name, 242 dir->entries[dir->nr -1]->name) <0)) 243 dir->sorted = dir->nr; 244} 245 246/* 247 * Clear and free all entries in dir, recursively. 248 */ 249static voidclear_ref_dir(struct ref_dir *dir) 250{ 251int i; 252for(i =0; i < dir->nr; i++) 253free_ref_entry(dir->entries[i]); 254free(dir->entries); 255 dir->sorted = dir->nr = dir->alloc =0; 256 dir->entries = NULL; 257} 258 259/* 260 * Create a struct ref_entry object for the specified dirname. 261 * dirname is the name of the directory with a trailing slash (e.g., 262 * "refs/heads/") or "" for the top-level directory. 263 */ 264static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 265const char*dirname,size_t len, 266int incomplete) 267{ 268struct ref_entry *direntry; 269FLEX_ALLOC_MEM(direntry, name, dirname, len); 270 direntry->u.subdir.ref_store = ref_store; 271 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 272return direntry; 273} 274 275static intref_entry_cmp(const void*a,const void*b) 276{ 277struct ref_entry *one = *(struct ref_entry **)a; 278struct ref_entry *two = *(struct ref_entry **)b; 279returnstrcmp(one->name, two->name); 280} 281 282static voidsort_ref_dir(struct ref_dir *dir); 283 284struct string_slice { 285size_t len; 286const char*str; 287}; 288 289static intref_entry_cmp_sslice(const void*key_,const void*ent_) 290{ 291const struct string_slice *key = key_; 292const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 293int cmp =strncmp(key->str, ent->name, key->len); 294if(cmp) 295return cmp; 296return'\0'- (unsigned char)ent->name[key->len]; 297} 298 299/* 300 * Return the index of the entry with the given refname from the 301 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 302 * no such entry is found. dir must already be complete. 303 */ 304static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 305{ 306struct ref_entry **r; 307struct string_slice key; 308 309if(refname == NULL || !dir->nr) 310return-1; 311 312sort_ref_dir(dir); 313 key.len = len; 314 key.str = refname; 315 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 316 ref_entry_cmp_sslice); 317 318if(r == NULL) 319return-1; 320 321return r - dir->entries; 322} 323 324/* 325 * Search for a directory entry directly within dir (without 326 * recursing). Sort dir if necessary. subdirname must be a directory 327 * name (i.e., end in '/'). If mkdir is set, then create the 328 * directory if it is missing; otherwise, return NULL if the desired 329 * directory cannot be found. dir must already be complete. 330 */ 331static struct ref_dir *search_for_subdir(struct ref_dir *dir, 332const char*subdirname,size_t len, 333int mkdir) 334{ 335int entry_index =search_ref_dir(dir, subdirname, len); 336struct ref_entry *entry; 337if(entry_index == -1) { 338if(!mkdir) 339return NULL; 340/* 341 * Since dir is complete, the absence of a subdir 342 * means that the subdir really doesn't exist; 343 * therefore, create an empty record for it but mark 344 * the record complete. 345 */ 346 entry =create_dir_entry(dir->ref_store, subdirname, len,0); 347add_entry_to_dir(dir, entry); 348}else{ 349 entry = dir->entries[entry_index]; 350} 351returnget_ref_dir(entry); 352} 353 354/* 355 * If refname is a reference name, find the ref_dir within the dir 356 * tree that should hold refname. If refname is a directory name 357 * (i.e., ends in '/'), then return that ref_dir itself. dir must 358 * represent the top-level directory and must already be complete. 359 * Sort ref_dirs and recurse into subdirectories as necessary. If 360 * mkdir is set, then create any missing directories; otherwise, 361 * return NULL if the desired directory cannot be found. 362 */ 363static struct ref_dir *find_containing_dir(struct ref_dir *dir, 364const char*refname,int mkdir) 365{ 366const char*slash; 367for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 368size_t dirnamelen = slash - refname +1; 369struct ref_dir *subdir; 370 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 371if(!subdir) { 372 dir = NULL; 373break; 374} 375 dir = subdir; 376} 377 378return dir; 379} 380 381/* 382 * Find the value entry with the given name in dir, sorting ref_dirs 383 * and recursing into subdirectories as necessary. If the name is not 384 * found or it corresponds to a directory entry, return NULL. 385 */ 386static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 387{ 388int entry_index; 389struct ref_entry *entry; 390 dir =find_containing_dir(dir, refname,0); 391if(!dir) 392return NULL; 393 entry_index =search_ref_dir(dir, refname,strlen(refname)); 394if(entry_index == -1) 395return NULL; 396 entry = dir->entries[entry_index]; 397return(entry->flag & REF_DIR) ? NULL : entry; 398} 399 400/* 401 * Remove the entry with the given name from dir, recursing into 402 * subdirectories as necessary. If refname is the name of a directory 403 * (i.e., ends with '/'), then remove the directory and its contents. 404 * If the removal was successful, return the number of entries 405 * remaining in the directory entry that contained the deleted entry. 406 * If the name was not found, return -1. Please note that this 407 * function only deletes the entry from the cache; it does not delete 408 * it from the filesystem or ensure that other cache entries (which 409 * might be symbolic references to the removed entry) are updated. 410 * Nor does it remove any containing dir entries that might be made 411 * empty by the removal. dir must represent the top-level directory 412 * and must already be complete. 413 */ 414static intremove_entry(struct ref_dir *dir,const char*refname) 415{ 416int refname_len =strlen(refname); 417int entry_index; 418struct ref_entry *entry; 419int is_dir = refname[refname_len -1] =='/'; 420if(is_dir) { 421/* 422 * refname represents a reference directory. Remove 423 * the trailing slash; otherwise we will get the 424 * directory *representing* refname rather than the 425 * one *containing* it. 426 */ 427char*dirname =xmemdupz(refname, refname_len -1); 428 dir =find_containing_dir(dir, dirname,0); 429free(dirname); 430}else{ 431 dir =find_containing_dir(dir, refname,0); 432} 433if(!dir) 434return-1; 435 entry_index =search_ref_dir(dir, refname, refname_len); 436if(entry_index == -1) 437return-1; 438 entry = dir->entries[entry_index]; 439 440memmove(&dir->entries[entry_index], 441&dir->entries[entry_index +1], 442(dir->nr - entry_index -1) *sizeof(*dir->entries) 443); 444 dir->nr--; 445if(dir->sorted > entry_index) 446 dir->sorted--; 447free_ref_entry(entry); 448return dir->nr; 449} 450 451/* 452 * Add a ref_entry to the ref_dir (unsorted), recursing into 453 * subdirectories as necessary. dir must represent the top-level 454 * directory. Return 0 on success. 455 */ 456static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 457{ 458 dir =find_containing_dir(dir, ref->name,1); 459if(!dir) 460return-1; 461add_entry_to_dir(dir, ref); 462return0; 463} 464 465/* 466 * Emit a warning and return true iff ref1 and ref2 have the same name 467 * and the same sha1. Die if they have the same name but different 468 * sha1s. 469 */ 470static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 471{ 472if(strcmp(ref1->name, ref2->name)) 473return0; 474 475/* Duplicate name; make sure that they don't conflict: */ 476 477if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 478/* This is impossible by construction */ 479die("Reference directory conflict:%s", ref1->name); 480 481if(oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) 482die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 483 484warning("Duplicated ref:%s", ref1->name); 485return1; 486} 487 488/* 489 * Sort the entries in dir non-recursively (if they are not already 490 * sorted) and remove any duplicate entries. 491 */ 492static voidsort_ref_dir(struct ref_dir *dir) 493{ 494int i, j; 495struct ref_entry *last = NULL; 496 497/* 498 * This check also prevents passing a zero-length array to qsort(), 499 * which is a problem on some platforms. 500 */ 501if(dir->sorted == dir->nr) 502return; 503 504qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 505 506/* Remove any duplicates: */ 507for(i =0, j =0; j < dir->nr; j++) { 508struct ref_entry *entry = dir->entries[j]; 509if(last &&is_dup_ref(last, entry)) 510free_ref_entry(entry); 511else 512 last = dir->entries[i++] = entry; 513} 514 dir->sorted = dir->nr = i; 515} 516 517/* 518 * Return true if refname, which has the specified oid and flags, can 519 * be resolved to an object in the database. If the referred-to object 520 * does not exist, emit a warning and return false. 521 */ 522static intref_resolves_to_object(const char*refname, 523const struct object_id *oid, 524unsigned int flags) 525{ 526if(flags & REF_ISBROKEN) 527return0; 528if(!has_sha1_file(oid->hash)) { 529error("%sdoes not point to a valid object!", refname); 530return0; 531} 532return1; 533} 534 535/* 536 * Return true if the reference described by entry can be resolved to 537 * an object in the database; otherwise, emit a warning and return 538 * false. 539 */ 540static intentry_resolves_to_object(struct ref_entry *entry) 541{ 542returnref_resolves_to_object(entry->name, 543&entry->u.value.oid, entry->flag); 544} 545 546typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 547 548/* 549 * Call fn for each reference in dir that has index in the range 550 * offset <= index < dir->nr. Recurse into subdirectories that are in 551 * that index range, sorting them before iterating. This function 552 * does not sort dir itself; it should be sorted beforehand. fn is 553 * called for all references, including broken ones. 554 */ 555static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 556 each_ref_entry_fn fn,void*cb_data) 557{ 558int i; 559assert(dir->sorted == dir->nr); 560for(i = offset; i < dir->nr; i++) { 561struct ref_entry *entry = dir->entries[i]; 562int retval; 563if(entry->flag & REF_DIR) { 564struct ref_dir *subdir =get_ref_dir(entry); 565sort_ref_dir(subdir); 566 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 567}else{ 568 retval =fn(entry, cb_data); 569} 570if(retval) 571return retval; 572} 573return0; 574} 575 576/* 577 * Load all of the refs from the dir into our in-memory cache. The hard work 578 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 579 * through all of the sub-directories. We do not even need to care about 580 * sorting, as traversal order does not matter to us. 581 */ 582static voidprime_ref_dir(struct ref_dir *dir) 583{ 584int i; 585for(i =0; i < dir->nr; i++) { 586struct ref_entry *entry = dir->entries[i]; 587if(entry->flag & REF_DIR) 588prime_ref_dir(get_ref_dir(entry)); 589} 590} 591 592/* 593 * A level in the reference hierarchy that is currently being iterated 594 * through. 595 */ 596struct cache_ref_iterator_level { 597/* 598 * The ref_dir being iterated over at this level. The ref_dir 599 * is sorted before being stored here. 600 */ 601struct ref_dir *dir; 602 603/* 604 * The index of the current entry within dir (which might 605 * itself be a directory). If index == -1, then the iteration 606 * hasn't yet begun. If index == dir->nr, then the iteration 607 * through this level is over. 608 */ 609int index; 610}; 611 612/* 613 * Represent an iteration through a ref_dir in the memory cache. The 614 * iteration recurses through subdirectories. 615 */ 616struct cache_ref_iterator { 617struct ref_iterator base; 618 619/* 620 * The number of levels currently on the stack. This is always 621 * at least 1, because when it becomes zero the iteration is 622 * ended and this struct is freed. 623 */ 624size_t levels_nr; 625 626/* The number of levels that have been allocated on the stack */ 627size_t levels_alloc; 628 629/* 630 * A stack of levels. levels[0] is the uppermost level that is 631 * being iterated over in this iteration. (This is not 632 * necessary the top level in the references hierarchy. If we 633 * are iterating through a subtree, then levels[0] will hold 634 * the ref_dir for that subtree, and subsequent levels will go 635 * on from there.) 636 */ 637struct cache_ref_iterator_level *levels; 638}; 639 640static intcache_ref_iterator_advance(struct ref_iterator *ref_iterator) 641{ 642struct cache_ref_iterator *iter = 643(struct cache_ref_iterator *)ref_iterator; 644 645while(1) { 646struct cache_ref_iterator_level *level = 647&iter->levels[iter->levels_nr -1]; 648struct ref_dir *dir = level->dir; 649struct ref_entry *entry; 650 651if(level->index == -1) 652sort_ref_dir(dir); 653 654if(++level->index == level->dir->nr) { 655/* This level is exhausted; pop up a level */ 656if(--iter->levels_nr ==0) 657returnref_iterator_abort(ref_iterator); 658 659continue; 660} 661 662 entry = dir->entries[level->index]; 663 664if(entry->flag & REF_DIR) { 665/* push down a level */ 666ALLOC_GROW(iter->levels, iter->levels_nr +1, 667 iter->levels_alloc); 668 669 level = &iter->levels[iter->levels_nr++]; 670 level->dir =get_ref_dir(entry); 671 level->index = -1; 672}else{ 673 iter->base.refname = entry->name; 674 iter->base.oid = &entry->u.value.oid; 675 iter->base.flags = entry->flag; 676return ITER_OK; 677} 678} 679} 680 681static enum peel_status peel_entry(struct ref_entry *entry,int repeel); 682 683static intcache_ref_iterator_peel(struct ref_iterator *ref_iterator, 684struct object_id *peeled) 685{ 686struct cache_ref_iterator *iter = 687(struct cache_ref_iterator *)ref_iterator; 688struct cache_ref_iterator_level *level; 689struct ref_entry *entry; 690 691 level = &iter->levels[iter->levels_nr -1]; 692 693if(level->index == -1) 694die("BUG: peel called before advance for cache iterator"); 695 696 entry = level->dir->entries[level->index]; 697 698if(peel_entry(entry,0)) 699return-1; 700hashcpy(peeled->hash, entry->u.value.peeled.hash); 701return0; 702} 703 704static intcache_ref_iterator_abort(struct ref_iterator *ref_iterator) 705{ 706struct cache_ref_iterator *iter = 707(struct cache_ref_iterator *)ref_iterator; 708 709free(iter->levels); 710base_ref_iterator_free(ref_iterator); 711return ITER_DONE; 712} 713 714static struct ref_iterator_vtable cache_ref_iterator_vtable = { 715 cache_ref_iterator_advance, 716 cache_ref_iterator_peel, 717 cache_ref_iterator_abort 718}; 719 720static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir) 721{ 722struct cache_ref_iterator *iter; 723struct ref_iterator *ref_iterator; 724struct cache_ref_iterator_level *level; 725 726 iter =xcalloc(1,sizeof(*iter)); 727 ref_iterator = &iter->base; 728base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable); 729ALLOC_GROW(iter->levels,10, iter->levels_alloc); 730 731 iter->levels_nr =1; 732 level = &iter->levels[0]; 733 level->index = -1; 734 level->dir = dir; 735 736return ref_iterator; 737} 738 739struct nonmatching_ref_data { 740const struct string_list *skip; 741const char*conflicting_refname; 742}; 743 744static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 745{ 746struct nonmatching_ref_data *data = vdata; 747 748if(data->skip &&string_list_has_string(data->skip, entry->name)) 749return0; 750 751 data->conflicting_refname = entry->name; 752return1; 753} 754 755/* 756 * Return 0 if a reference named refname could be created without 757 * conflicting with the name of an existing reference in dir. 758 * See verify_refname_available for more information. 759 */ 760static intverify_refname_available_dir(const char*refname, 761const struct string_list *extras, 762const struct string_list *skip, 763struct ref_dir *dir, 764struct strbuf *err) 765{ 766const char*slash; 767const char*extra_refname; 768int pos; 769struct strbuf dirname = STRBUF_INIT; 770int ret = -1; 771 772/* 773 * For the sake of comments in this function, suppose that 774 * refname is "refs/foo/bar". 775 */ 776 777assert(err); 778 779strbuf_grow(&dirname,strlen(refname) +1); 780for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 781/* Expand dirname to the new prefix, not including the trailing slash: */ 782strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); 783 784/* 785 * We are still at a leading dir of the refname (e.g., 786 * "refs/foo"; if there is a reference with that name, 787 * it is a conflict, *unless* it is in skip. 788 */ 789if(dir) { 790 pos =search_ref_dir(dir, dirname.buf, dirname.len); 791if(pos >=0&& 792(!skip || !string_list_has_string(skip, dirname.buf))) { 793/* 794 * We found a reference whose name is 795 * a proper prefix of refname; e.g., 796 * "refs/foo", and is not in skip. 797 */ 798strbuf_addf(err,"'%s' exists; cannot create '%s'", 799 dirname.buf, refname); 800goto cleanup; 801} 802} 803 804if(extras &&string_list_has_string(extras, dirname.buf) && 805(!skip || !string_list_has_string(skip, dirname.buf))) { 806strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 807 refname, dirname.buf); 808goto cleanup; 809} 810 811/* 812 * Otherwise, we can try to continue our search with 813 * the next component. So try to look up the 814 * directory, e.g., "refs/foo/". If we come up empty, 815 * we know there is nothing under this whole prefix, 816 * but even in that case we still have to continue the 817 * search for conflicts with extras. 818 */ 819strbuf_addch(&dirname,'/'); 820if(dir) { 821 pos =search_ref_dir(dir, dirname.buf, dirname.len); 822if(pos <0) { 823/* 824 * There was no directory "refs/foo/", 825 * so there is nothing under this 826 * whole prefix. So there is no need 827 * to continue looking for conflicting 828 * references. But we need to continue 829 * looking for conflicting extras. 830 */ 831 dir = NULL; 832}else{ 833 dir =get_ref_dir(dir->entries[pos]); 834} 835} 836} 837 838/* 839 * We are at the leaf of our refname (e.g., "refs/foo/bar"). 840 * There is no point in searching for a reference with that 841 * name, because a refname isn't considered to conflict with 842 * itself. But we still need to check for references whose 843 * names are in the "refs/foo/bar/" namespace, because they 844 * *do* conflict. 845 */ 846strbuf_addstr(&dirname, refname + dirname.len); 847strbuf_addch(&dirname,'/'); 848 849if(dir) { 850 pos =search_ref_dir(dir, dirname.buf, dirname.len); 851 852if(pos >=0) { 853/* 854 * We found a directory named "$refname/" 855 * (e.g., "refs/foo/bar/"). It is a problem 856 * iff it contains any ref that is not in 857 * "skip". 858 */ 859struct nonmatching_ref_data data; 860 861 data.skip = skip; 862 data.conflicting_refname = NULL; 863 dir =get_ref_dir(dir->entries[pos]); 864sort_ref_dir(dir); 865if(do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) { 866strbuf_addf(err,"'%s' exists; cannot create '%s'", 867 data.conflicting_refname, refname); 868goto cleanup; 869} 870} 871} 872 873 extra_refname =find_descendant_ref(dirname.buf, extras, skip); 874if(extra_refname) 875strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 876 refname, extra_refname); 877else 878 ret =0; 879 880cleanup: 881strbuf_release(&dirname); 882return ret; 883} 884 885struct packed_ref_cache { 886struct ref_entry *root; 887 888/* 889 * Count of references to the data structure in this instance, 890 * including the pointer from files_ref_store::packed if any. 891 * The data will not be freed as long as the reference count 892 * is nonzero. 893 */ 894unsigned int referrers; 895 896/* 897 * Iff the packed-refs file associated with this instance is 898 * currently locked for writing, this points at the associated 899 * lock (which is owned by somebody else). The referrer count 900 * is also incremented when the file is locked and decremented 901 * when it is unlocked. 902 */ 903struct lock_file *lock; 904 905/* The metadata from when this packed-refs cache was read */ 906struct stat_validity validity; 907}; 908 909/* 910 * Future: need to be in "struct repository" 911 * when doing a full libification. 912 */ 913struct files_ref_store { 914struct ref_store base; 915struct ref_entry *loose; 916struct packed_ref_cache *packed; 917}; 918 919/* Lock used for the main packed-refs file: */ 920static struct lock_file packlock; 921 922/* 923 * Increment the reference count of *packed_refs. 924 */ 925static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 926{ 927 packed_refs->referrers++; 928} 929 930/* 931 * Decrease the reference count of *packed_refs. If it goes to zero, 932 * free *packed_refs and return true; otherwise return false. 933 */ 934static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 935{ 936if(!--packed_refs->referrers) { 937free_ref_entry(packed_refs->root); 938stat_validity_clear(&packed_refs->validity); 939free(packed_refs); 940return1; 941}else{ 942return0; 943} 944} 945 946static voidclear_packed_ref_cache(struct files_ref_store *refs) 947{ 948if(refs->packed) { 949struct packed_ref_cache *packed_refs = refs->packed; 950 951if(packed_refs->lock) 952die("internal error: packed-ref cache cleared while locked"); 953 refs->packed = NULL; 954release_packed_ref_cache(packed_refs); 955} 956} 957 958static voidclear_loose_ref_cache(struct files_ref_store *refs) 959{ 960if(refs->loose) { 961free_ref_entry(refs->loose); 962 refs->loose = NULL; 963} 964} 965 966/* 967 * Create a new submodule ref cache and add it to the internal 968 * set of caches. 969 */ 970static struct ref_store *files_ref_store_create(const char*submodule) 971{ 972struct files_ref_store *refs =xcalloc(1,sizeof(*refs)); 973struct ref_store *ref_store = (struct ref_store *)refs; 974 975base_ref_store_init(ref_store, &refs_be_files, submodule); 976 977return ref_store; 978} 979 980/* 981 * Downcast ref_store to files_ref_store. Die if ref_store is not a 982 * files_ref_store. If submodule_allowed is not true, then also die if 983 * files_ref_store is for a submodule (i.e., not for the main 984 * repository). caller is used in any necessary error messages. 985 */ 986static struct files_ref_store *files_downcast( 987struct ref_store *ref_store,int submodule_allowed, 988const char*caller) 989{ 990if(ref_store->be != &refs_be_files) 991die("BUG: ref_store is type\"%s\"not\"files\"in%s", 992 ref_store->be->name, caller); 993 994if(!submodule_allowed) 995assert_main_repository(ref_store, caller); 996 997return(struct files_ref_store *)ref_store; 998} 9991000/*1001 * Return a pointer to the reference store for the specified1002 * submodule. For the main repository, use submodule==NULL; such a1003 * call cannot fail. For a submodule, the submodule must exist and be1004 * a nonbare repository, otherwise return NULL. Verify that the1005 * reference store is a files_ref_store, and cast it to that type1006 * before returning it.1007 */1008static struct files_ref_store *get_files_ref_store(const char*submodule,1009const char*caller)1010{1011struct ref_store *refs =get_ref_store(submodule);10121013return refs ?files_downcast(refs,1, caller) : NULL;1014}10151016/* The length of a peeled reference line in packed-refs, including EOL: */1017#define PEELED_LINE_LENGTH 4210181019/*1020 * The packed-refs header line that we write out. Perhaps other1021 * traits will be added later. The trailing space is required.1022 */1023static const char PACKED_REFS_HEADER[] =1024"# pack-refs with: peeled fully-peeled\n";10251026/*1027 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1028 * Return a pointer to the refname within the line (null-terminated),1029 * or NULL if there was a problem.1030 */1031static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1032{1033const char*ref;10341035/*1036 * 42: the answer to everything.1037 *1038 * In this case, it happens to be the answer to1039 * 40 (length of sha1 hex representation)1040 * +1 (space in between hex and name)1041 * +1 (newline at the end of the line)1042 */1043if(line->len <=42)1044return NULL;10451046if(get_sha1_hex(line->buf, sha1) <0)1047return NULL;1048if(!isspace(line->buf[40]))1049return NULL;10501051 ref = line->buf +41;1052if(isspace(*ref))1053return NULL;10541055if(line->buf[line->len -1] !='\n')1056return NULL;1057 line->buf[--line->len] =0;10581059return ref;1060}10611062/*1063 * Read f, which is a packed-refs file, into dir.1064 *1065 * A comment line of the form "# pack-refs with: " may contain zero or1066 * more traits. We interpret the traits as follows:1067 *1068 * No traits:1069 *1070 * Probably no references are peeled. But if the file contains a1071 * peeled value for a reference, we will use it.1072 *1073 * peeled:1074 *1075 * References under "refs/tags/", if they *can* be peeled, *are*1076 * peeled in this file. References outside of "refs/tags/" are1077 * probably not peeled even if they could have been, but if we find1078 * a peeled value for such a reference we will use it.1079 *1080 * fully-peeled:1081 *1082 * All references in the file that can be peeled are peeled.1083 * Inversely (and this is more important), any references in the1084 * file for which no peeled value is recorded is not peelable. This1085 * trait should typically be written alongside "peeled" for1086 * compatibility with older clients, but we do not require it1087 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1088 */1089static voidread_packed_refs(FILE*f,struct ref_dir *dir)1090{1091struct ref_entry *last = NULL;1092struct strbuf line = STRBUF_INIT;1093enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10941095while(strbuf_getwholeline(&line, f,'\n') != EOF) {1096unsigned char sha1[20];1097const char*refname;1098const char*traits;10991100if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1101if(strstr(traits," fully-peeled "))1102 peeled = PEELED_FULLY;1103else if(strstr(traits," peeled "))1104 peeled = PEELED_TAGS;1105/* perhaps other traits later as well */1106continue;1107}11081109 refname =parse_ref_line(&line, sha1);1110if(refname) {1111int flag = REF_ISPACKED;11121113if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1114if(!refname_is_safe(refname))1115die("packed refname is dangerous:%s", refname);1116hashclr(sha1);1117 flag |= REF_BAD_NAME | REF_ISBROKEN;1118}1119 last =create_ref_entry(refname, sha1, flag,0);1120if(peeled == PEELED_FULLY ||1121(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1122 last->flag |= REF_KNOWS_PEELED;1123add_ref(dir, last);1124continue;1125}1126if(last &&1127 line.buf[0] =='^'&&1128 line.len == PEELED_LINE_LENGTH &&1129 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1130!get_sha1_hex(line.buf +1, sha1)) {1131hashcpy(last->u.value.peeled.hash, sha1);1132/*1133 * Regardless of what the file header said,1134 * we definitely know the value of *this*1135 * reference:1136 */1137 last->flag |= REF_KNOWS_PEELED;1138}1139}11401141strbuf_release(&line);1142}11431144/*1145 * Get the packed_ref_cache for the specified files_ref_store,1146 * creating it if necessary.1147 */1148static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1149{1150char*packed_refs_file;11511152if(*refs->base.submodule)1153 packed_refs_file =git_pathdup_submodule(refs->base.submodule,1154"packed-refs");1155else1156 packed_refs_file =git_pathdup("packed-refs");11571158if(refs->packed &&1159!stat_validity_check(&refs->packed->validity, packed_refs_file))1160clear_packed_ref_cache(refs);11611162if(!refs->packed) {1163FILE*f;11641165 refs->packed =xcalloc(1,sizeof(*refs->packed));1166acquire_packed_ref_cache(refs->packed);1167 refs->packed->root =create_dir_entry(refs,"",0,0);1168 f =fopen(packed_refs_file,"r");1169if(f) {1170stat_validity_update(&refs->packed->validity,fileno(f));1171read_packed_refs(f,get_ref_dir(refs->packed->root));1172fclose(f);1173}1174}1175free(packed_refs_file);1176return refs->packed;1177}11781179static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1180{1181returnget_ref_dir(packed_ref_cache->root);1182}11831184static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1185{1186returnget_packed_ref_dir(get_packed_ref_cache(refs));1187}11881189/*1190 * Add a reference to the in-memory packed reference cache. This may1191 * only be called while the packed-refs file is locked (see1192 * lock_packed_refs()). To actually write the packed-refs file, call1193 * commit_packed_refs().1194 */1195static voidadd_packed_ref(struct files_ref_store *refs,1196const char*refname,const unsigned char*sha1)1197{1198struct packed_ref_cache *packed_ref_cache =get_packed_ref_cache(refs);11991200if(!packed_ref_cache->lock)1201die("internal error: packed refs not locked");1202add_ref(get_packed_ref_dir(packed_ref_cache),1203create_ref_entry(refname, sha1, REF_ISPACKED,1));1204}12051206/*1207 * Read the loose references from the namespace dirname into dir1208 * (without recursing). dirname must end with '/'. dir must be the1209 * directory entry corresponding to dirname.1210 */1211static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1212{1213struct files_ref_store *refs = dir->ref_store;1214DIR*d;1215struct dirent *de;1216int dirnamelen =strlen(dirname);1217struct strbuf refname;1218struct strbuf path = STRBUF_INIT;1219size_t path_baselen;12201221if(*refs->base.submodule)1222strbuf_git_path_submodule(&path, refs->base.submodule,"%s", dirname);1223else1224strbuf_git_path(&path,"%s", dirname);1225 path_baselen = path.len;12261227 d =opendir(path.buf);1228if(!d) {1229strbuf_release(&path);1230return;1231}12321233strbuf_init(&refname, dirnamelen +257);1234strbuf_add(&refname, dirname, dirnamelen);12351236while((de =readdir(d)) != NULL) {1237unsigned char sha1[20];1238struct stat st;1239int flag;12401241if(de->d_name[0] =='.')1242continue;1243if(ends_with(de->d_name,".lock"))1244continue;1245strbuf_addstr(&refname, de->d_name);1246strbuf_addstr(&path, de->d_name);1247if(stat(path.buf, &st) <0) {1248;/* silently ignore */1249}else if(S_ISDIR(st.st_mode)) {1250strbuf_addch(&refname,'/');1251add_entry_to_dir(dir,1252create_dir_entry(refs, refname.buf,1253 refname.len,1));1254}else{1255int read_ok;12561257if(*refs->base.submodule) {1258hashclr(sha1);1259 flag =0;1260 read_ok = !resolve_gitlink_ref(refs->base.submodule,1261 refname.buf, sha1);1262}else{1263 read_ok = !read_ref_full(refname.buf,1264 RESOLVE_REF_READING,1265 sha1, &flag);1266}12671268if(!read_ok) {1269hashclr(sha1);1270 flag |= REF_ISBROKEN;1271}else if(is_null_sha1(sha1)) {1272/*1273 * It is so astronomically unlikely1274 * that NULL_SHA1 is the SHA-1 of an1275 * actual object that we consider its1276 * appearance in a loose reference1277 * file to be repo corruption1278 * (probably due to a software bug).1279 */1280 flag |= REF_ISBROKEN;1281}12821283if(check_refname_format(refname.buf,1284 REFNAME_ALLOW_ONELEVEL)) {1285if(!refname_is_safe(refname.buf))1286die("loose refname is dangerous:%s", refname.buf);1287hashclr(sha1);1288 flag |= REF_BAD_NAME | REF_ISBROKEN;1289}1290add_entry_to_dir(dir,1291create_ref_entry(refname.buf, sha1, flag,0));1292}1293strbuf_setlen(&refname, dirnamelen);1294strbuf_setlen(&path, path_baselen);1295}1296strbuf_release(&refname);1297strbuf_release(&path);1298closedir(d);1299}13001301static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1302{1303if(!refs->loose) {1304/*1305 * Mark the top-level directory complete because we1306 * are about to read the only subdirectory that can1307 * hold references:1308 */1309 refs->loose =create_dir_entry(refs,"",0,0);1310/*1311 * Create an incomplete entry for "refs/":1312 */1313add_entry_to_dir(get_ref_dir(refs->loose),1314create_dir_entry(refs,"refs/",5,1));1315}1316returnget_ref_dir(refs->loose);1317}13181319/*1320 * Return the ref_entry for the given refname from the packed1321 * references. If it does not exist, return NULL.1322 */1323static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1324const char*refname)1325{1326returnfind_ref(get_packed_refs(refs), refname);1327}13281329/*1330 * A loose ref file doesn't exist; check for a packed ref.1331 */1332static intresolve_packed_ref(struct files_ref_store *refs,1333const char*refname,1334unsigned char*sha1,unsigned int*flags)1335{1336struct ref_entry *entry;13371338/*1339 * The loose reference file does not exist; check for a packed1340 * reference.1341 */1342 entry =get_packed_ref(refs, refname);1343if(entry) {1344hashcpy(sha1, entry->u.value.oid.hash);1345*flags |= REF_ISPACKED;1346return0;1347}1348/* refname is not a packed reference. */1349return-1;1350}13511352static intfiles_read_raw_ref(struct ref_store *ref_store,1353const char*refname,unsigned char*sha1,1354struct strbuf *referent,unsigned int*type)1355{1356struct files_ref_store *refs =1357files_downcast(ref_store,1,"read_raw_ref");1358struct strbuf sb_contents = STRBUF_INIT;1359struct strbuf sb_path = STRBUF_INIT;1360const char*path;1361const char*buf;1362struct stat st;1363int fd;1364int ret = -1;1365int save_errno;13661367*type =0;1368strbuf_reset(&sb_path);13691370if(*refs->base.submodule)1371strbuf_git_path_submodule(&sb_path, refs->base.submodule,"%s", refname);1372else1373strbuf_git_path(&sb_path,"%s", refname);13741375 path = sb_path.buf;13761377stat_ref:1378/*1379 * We might have to loop back here to avoid a race1380 * condition: first we lstat() the file, then we try1381 * to read it as a link or as a file. But if somebody1382 * changes the type of the file (file <-> directory1383 * <-> symlink) between the lstat() and reading, then1384 * we don't want to report that as an error but rather1385 * try again starting with the lstat().1386 */13871388if(lstat(path, &st) <0) {1389if(errno != ENOENT)1390goto out;1391if(resolve_packed_ref(refs, refname, sha1, type)) {1392 errno = ENOENT;1393goto out;1394}1395 ret =0;1396goto out;1397}13981399/* Follow "normalized" - ie "refs/.." symlinks by hand */1400if(S_ISLNK(st.st_mode)) {1401strbuf_reset(&sb_contents);1402if(strbuf_readlink(&sb_contents, path,0) <0) {1403if(errno == ENOENT || errno == EINVAL)1404/* inconsistent with lstat; retry */1405goto stat_ref;1406else1407goto out;1408}1409if(starts_with(sb_contents.buf,"refs/") &&1410!check_refname_format(sb_contents.buf,0)) {1411strbuf_swap(&sb_contents, referent);1412*type |= REF_ISSYMREF;1413 ret =0;1414goto out;1415}1416}14171418/* Is it a directory? */1419if(S_ISDIR(st.st_mode)) {1420/*1421 * Even though there is a directory where the loose1422 * ref is supposed to be, there could still be a1423 * packed ref:1424 */1425if(resolve_packed_ref(refs, refname, sha1, type)) {1426 errno = EISDIR;1427goto out;1428}1429 ret =0;1430goto out;1431}14321433/*1434 * Anything else, just open it and try to use it as1435 * a ref1436 */1437 fd =open(path, O_RDONLY);1438if(fd <0) {1439if(errno == ENOENT)1440/* inconsistent with lstat; retry */1441goto stat_ref;1442else1443goto out;1444}1445strbuf_reset(&sb_contents);1446if(strbuf_read(&sb_contents, fd,256) <0) {1447int save_errno = errno;1448close(fd);1449 errno = save_errno;1450goto out;1451}1452close(fd);1453strbuf_rtrim(&sb_contents);1454 buf = sb_contents.buf;1455if(starts_with(buf,"ref:")) {1456 buf +=4;1457while(isspace(*buf))1458 buf++;14591460strbuf_reset(referent);1461strbuf_addstr(referent, buf);1462*type |= REF_ISSYMREF;1463 ret =0;1464goto out;1465}14661467/*1468 * Please note that FETCH_HEAD has additional1469 * data after the sha.1470 */1471if(get_sha1_hex(buf, sha1) ||1472(buf[40] !='\0'&& !isspace(buf[40]))) {1473*type |= REF_ISBROKEN;1474 errno = EINVAL;1475goto out;1476}14771478 ret =0;14791480out:1481 save_errno = errno;1482strbuf_release(&sb_path);1483strbuf_release(&sb_contents);1484 errno = save_errno;1485return ret;1486}14871488static voidunlock_ref(struct ref_lock *lock)1489{1490/* Do not free lock->lk -- atexit() still looks at them */1491if(lock->lk)1492rollback_lock_file(lock->lk);1493free(lock->ref_name);1494free(lock);1495}14961497/*1498 * Lock refname, without following symrefs, and set *lock_p to point1499 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1500 * and type similarly to read_raw_ref().1501 *1502 * The caller must verify that refname is a "safe" reference name (in1503 * the sense of refname_is_safe()) before calling this function.1504 *1505 * If the reference doesn't already exist, verify that refname doesn't1506 * have a D/F conflict with any existing references. extras and skip1507 * are passed to verify_refname_available_dir() for this check.1508 *1509 * If mustexist is not set and the reference is not found or is1510 * broken, lock the reference anyway but clear sha1.1511 *1512 * Return 0 on success. On failure, write an error message to err and1513 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1514 *1515 * Implementation note: This function is basically1516 *1517 * lock reference1518 * read_raw_ref()1519 *1520 * but it includes a lot more code to1521 * - Deal with possible races with other processes1522 * - Avoid calling verify_refname_available_dir() when it can be1523 * avoided, namely if we were successfully able to read the ref1524 * - Generate informative error messages in the case of failure1525 */1526static intlock_raw_ref(struct files_ref_store *refs,1527const char*refname,int mustexist,1528const struct string_list *extras,1529const struct string_list *skip,1530struct ref_lock **lock_p,1531struct strbuf *referent,1532unsigned int*type,1533struct strbuf *err)1534{1535struct ref_lock *lock;1536struct strbuf ref_file = STRBUF_INIT;1537int attempts_remaining =3;1538int ret = TRANSACTION_GENERIC_ERROR;15391540assert(err);1541assert_main_repository(&refs->base,"lock_raw_ref");15421543*type =0;15441545/* First lock the file so it can't change out from under us. */15461547*lock_p = lock =xcalloc(1,sizeof(*lock));15481549 lock->ref_name =xstrdup(refname);1550strbuf_git_path(&ref_file,"%s", refname);15511552retry:1553switch(safe_create_leading_directories(ref_file.buf)) {1554case SCLD_OK:1555break;/* success */1556case SCLD_EXISTS:1557/*1558 * Suppose refname is "refs/foo/bar". We just failed1559 * to create the containing directory, "refs/foo",1560 * because there was a non-directory in the way. This1561 * indicates a D/F conflict, probably because of1562 * another reference such as "refs/foo". There is no1563 * reason to expect this error to be transitory.1564 */1565if(verify_refname_available(refname, extras, skip, err)) {1566if(mustexist) {1567/*1568 * To the user the relevant error is1569 * that the "mustexist" reference is1570 * missing:1571 */1572strbuf_reset(err);1573strbuf_addf(err,"unable to resolve reference '%s'",1574 refname);1575}else{1576/*1577 * The error message set by1578 * verify_refname_available_dir() is OK.1579 */1580 ret = TRANSACTION_NAME_CONFLICT;1581}1582}else{1583/*1584 * The file that is in the way isn't a loose1585 * reference. Report it as a low-level1586 * failure.1587 */1588strbuf_addf(err,"unable to create lock file%s.lock; "1589"non-directory in the way",1590 ref_file.buf);1591}1592goto error_return;1593case SCLD_VANISHED:1594/* Maybe another process was tidying up. Try again. */1595if(--attempts_remaining >0)1596goto retry;1597/* fall through */1598default:1599strbuf_addf(err,"unable to create directory for%s",1600 ref_file.buf);1601goto error_return;1602}16031604if(!lock->lk)1605 lock->lk =xcalloc(1,sizeof(struct lock_file));16061607if(hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) <0) {1608if(errno == ENOENT && --attempts_remaining >0) {1609/*1610 * Maybe somebody just deleted one of the1611 * directories leading to ref_file. Try1612 * again:1613 */1614goto retry;1615}else{1616unable_to_lock_message(ref_file.buf, errno, err);1617goto error_return;1618}1619}16201621/*1622 * Now we hold the lock and can read the reference without1623 * fear that its value will change.1624 */16251626if(files_read_raw_ref(&refs->base, refname,1627 lock->old_oid.hash, referent, type)) {1628if(errno == ENOENT) {1629if(mustexist) {1630/* Garden variety missing reference. */1631strbuf_addf(err,"unable to resolve reference '%s'",1632 refname);1633goto error_return;1634}else{1635/*1636 * Reference is missing, but that's OK. We1637 * know that there is not a conflict with1638 * another loose reference because1639 * (supposing that we are trying to lock1640 * reference "refs/foo/bar"):1641 *1642 * - We were successfully able to create1643 * the lockfile refs/foo/bar.lock, so we1644 * know there cannot be a loose reference1645 * named "refs/foo".1646 *1647 * - We got ENOENT and not EISDIR, so we1648 * know that there cannot be a loose1649 * reference named "refs/foo/bar/baz".1650 */1651}1652}else if(errno == EISDIR) {1653/*1654 * There is a directory in the way. It might have1655 * contained references that have been deleted. If1656 * we don't require that the reference already1657 * exists, try to remove the directory so that it1658 * doesn't cause trouble when we want to rename the1659 * lockfile into place later.1660 */1661if(mustexist) {1662/* Garden variety missing reference. */1663strbuf_addf(err,"unable to resolve reference '%s'",1664 refname);1665goto error_return;1666}else if(remove_dir_recursively(&ref_file,1667 REMOVE_DIR_EMPTY_ONLY)) {1668if(verify_refname_available_dir(1669 refname, extras, skip,1670get_loose_refs(refs),1671 err)) {1672/*1673 * The error message set by1674 * verify_refname_available() is OK.1675 */1676 ret = TRANSACTION_NAME_CONFLICT;1677goto error_return;1678}else{1679/*1680 * We can't delete the directory,1681 * but we also don't know of any1682 * references that it should1683 * contain.1684 */1685strbuf_addf(err,"there is a non-empty directory '%s' "1686"blocking reference '%s'",1687 ref_file.buf, refname);1688goto error_return;1689}1690}1691}else if(errno == EINVAL && (*type & REF_ISBROKEN)) {1692strbuf_addf(err,"unable to resolve reference '%s': "1693"reference broken", refname);1694goto error_return;1695}else{1696strbuf_addf(err,"unable to resolve reference '%s':%s",1697 refname,strerror(errno));1698goto error_return;1699}17001701/*1702 * If the ref did not exist and we are creating it,1703 * make sure there is no existing packed ref whose1704 * name begins with our refname, nor a packed ref1705 * whose name is a proper prefix of our refname.1706 */1707if(verify_refname_available_dir(1708 refname, extras, skip,1709get_packed_refs(refs),1710 err)) {1711goto error_return;1712}1713}17141715 ret =0;1716goto out;17171718error_return:1719unlock_ref(lock);1720*lock_p = NULL;17211722out:1723strbuf_release(&ref_file);1724return ret;1725}17261727/*1728 * Peel the entry (if possible) and return its new peel_status. If1729 * repeel is true, re-peel the entry even if there is an old peeled1730 * value that is already stored in it.1731 *1732 * It is OK to call this function with a packed reference entry that1733 * might be stale and might even refer to an object that has since1734 * been garbage-collected. In such a case, if the entry has1735 * REF_KNOWS_PEELED then leave the status unchanged and return1736 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1737 */1738static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1739{1740enum peel_status status;17411742if(entry->flag & REF_KNOWS_PEELED) {1743if(repeel) {1744 entry->flag &= ~REF_KNOWS_PEELED;1745oidclr(&entry->u.value.peeled);1746}else{1747returnis_null_oid(&entry->u.value.peeled) ?1748 PEEL_NON_TAG : PEEL_PEELED;1749}1750}1751if(entry->flag & REF_ISBROKEN)1752return PEEL_BROKEN;1753if(entry->flag & REF_ISSYMREF)1754return PEEL_IS_SYMREF;17551756 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1757if(status == PEEL_PEELED || status == PEEL_NON_TAG)1758 entry->flag |= REF_KNOWS_PEELED;1759return status;1760}17611762static intfiles_peel_ref(struct ref_store *ref_store,1763const char*refname,unsigned char*sha1)1764{1765struct files_ref_store *refs =files_downcast(ref_store,0,"peel_ref");1766int flag;1767unsigned char base[20];17681769if(current_ref_iter && current_ref_iter->refname == refname) {1770struct object_id peeled;17711772if(ref_iterator_peel(current_ref_iter, &peeled))1773return-1;1774hashcpy(sha1, peeled.hash);1775return0;1776}17771778if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1779return-1;17801781/*1782 * If the reference is packed, read its ref_entry from the1783 * cache in the hope that we already know its peeled value.1784 * We only try this optimization on packed references because1785 * (a) forcing the filling of the loose reference cache could1786 * be expensive and (b) loose references anyway usually do not1787 * have REF_KNOWS_PEELED.1788 */1789if(flag & REF_ISPACKED) {1790struct ref_entry *r =get_packed_ref(refs, refname);1791if(r) {1792if(peel_entry(r,0))1793return-1;1794hashcpy(sha1, r->u.value.peeled.hash);1795return0;1796}1797}17981799returnpeel_object(base, sha1);1800}18011802struct files_ref_iterator {1803struct ref_iterator base;18041805struct packed_ref_cache *packed_ref_cache;1806struct ref_iterator *iter0;1807unsigned int flags;1808};18091810static intfiles_ref_iterator_advance(struct ref_iterator *ref_iterator)1811{1812struct files_ref_iterator *iter =1813(struct files_ref_iterator *)ref_iterator;1814int ok;18151816while((ok =ref_iterator_advance(iter->iter0)) == ITER_OK) {1817if(!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1818!ref_resolves_to_object(iter->iter0->refname,1819 iter->iter0->oid,1820 iter->iter0->flags))1821continue;18221823 iter->base.refname = iter->iter0->refname;1824 iter->base.oid = iter->iter0->oid;1825 iter->base.flags = iter->iter0->flags;1826return ITER_OK;1827}18281829 iter->iter0 = NULL;1830if(ref_iterator_abort(ref_iterator) != ITER_DONE)1831 ok = ITER_ERROR;18321833return ok;1834}18351836static intfiles_ref_iterator_peel(struct ref_iterator *ref_iterator,1837struct object_id *peeled)1838{1839struct files_ref_iterator *iter =1840(struct files_ref_iterator *)ref_iterator;18411842returnref_iterator_peel(iter->iter0, peeled);1843}18441845static intfiles_ref_iterator_abort(struct ref_iterator *ref_iterator)1846{1847struct files_ref_iterator *iter =1848(struct files_ref_iterator *)ref_iterator;1849int ok = ITER_DONE;18501851if(iter->iter0)1852 ok =ref_iterator_abort(iter->iter0);18531854release_packed_ref_cache(iter->packed_ref_cache);1855base_ref_iterator_free(ref_iterator);1856return ok;1857}18581859static struct ref_iterator_vtable files_ref_iterator_vtable = {1860 files_ref_iterator_advance,1861 files_ref_iterator_peel,1862 files_ref_iterator_abort1863};18641865struct ref_iterator *files_ref_iterator_begin(1866const char*submodule,1867const char*prefix,unsigned int flags)1868{1869struct files_ref_store *refs =1870get_files_ref_store(submodule,"ref_iterator_begin");1871struct ref_dir *loose_dir, *packed_dir;1872struct ref_iterator *loose_iter, *packed_iter;1873struct files_ref_iterator *iter;1874struct ref_iterator *ref_iterator;18751876if(!refs)1877returnempty_ref_iterator_begin();18781879if(ref_paranoia <0)1880 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1881if(ref_paranoia)1882 flags |= DO_FOR_EACH_INCLUDE_BROKEN;18831884 iter =xcalloc(1,sizeof(*iter));1885 ref_iterator = &iter->base;1886base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);18871888/*1889 * We must make sure that all loose refs are read before1890 * accessing the packed-refs file; this avoids a race1891 * condition if loose refs are migrated to the packed-refs1892 * file by a simultaneous process, but our in-memory view is1893 * from before the migration. We ensure this as follows:1894 * First, we call prime_ref_dir(), which pre-reads the loose1895 * references for the subtree into the cache. (If they've1896 * already been read, that's OK; we only need to guarantee1897 * that they're read before the packed refs, not *how much*1898 * before.) After that, we call get_packed_ref_cache(), which1899 * internally checks whether the packed-ref cache is up to1900 * date with what is on disk, and re-reads it if not.1901 */19021903 loose_dir =get_loose_refs(refs);19041905if(prefix && *prefix)1906 loose_dir =find_containing_dir(loose_dir, prefix,0);19071908if(loose_dir) {1909prime_ref_dir(loose_dir);1910 loose_iter =cache_ref_iterator_begin(loose_dir);1911}else{1912/* There's nothing to iterate over. */1913 loose_iter =empty_ref_iterator_begin();1914}19151916 iter->packed_ref_cache =get_packed_ref_cache(refs);1917acquire_packed_ref_cache(iter->packed_ref_cache);1918 packed_dir =get_packed_ref_dir(iter->packed_ref_cache);19191920if(prefix && *prefix)1921 packed_dir =find_containing_dir(packed_dir, prefix,0);19221923if(packed_dir) {1924 packed_iter =cache_ref_iterator_begin(packed_dir);1925}else{1926/* There's nothing to iterate over. */1927 packed_iter =empty_ref_iterator_begin();1928}19291930 iter->iter0 =overlay_ref_iterator_begin(loose_iter, packed_iter);1931 iter->flags = flags;19321933return ref_iterator;1934}19351936/*1937 * Verify that the reference locked by lock has the value old_sha1.1938 * Fail if the reference doesn't exist and mustexist is set. Return 01939 * on success. On error, write an error message to err, set errno, and1940 * return a negative value.1941 */1942static intverify_lock(struct ref_lock *lock,1943const unsigned char*old_sha1,int mustexist,1944struct strbuf *err)1945{1946assert(err);19471948if(read_ref_full(lock->ref_name,1949 mustexist ? RESOLVE_REF_READING :0,1950 lock->old_oid.hash, NULL)) {1951if(old_sha1) {1952int save_errno = errno;1953strbuf_addf(err,"can't verify ref '%s'", lock->ref_name);1954 errno = save_errno;1955return-1;1956}else{1957hashclr(lock->old_oid.hash);1958return0;1959}1960}1961if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {1962strbuf_addf(err,"ref '%s' is at%sbut expected%s",1963 lock->ref_name,1964sha1_to_hex(lock->old_oid.hash),1965sha1_to_hex(old_sha1));1966 errno = EBUSY;1967return-1;1968}1969return0;1970}19711972static intremove_empty_directories(struct strbuf *path)1973{1974/*1975 * we want to create a file but there is a directory there;1976 * if that is an empty directory (or a directory that contains1977 * only empty directories), remove them.1978 */1979returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1980}19811982/*1983 * Locks a ref returning the lock on success and NULL on failure.1984 * On failure errno is set to something meaningful.1985 */1986static struct ref_lock *lock_ref_sha1_basic(const char*refname,1987const unsigned char*old_sha1,1988const struct string_list *extras,1989const struct string_list *skip,1990unsigned int flags,int*type,1991struct strbuf *err)1992{1993struct files_ref_store *refs =1994get_files_ref_store(NULL,"lock_ref_sha1_basic");1995struct strbuf ref_file = STRBUF_INIT;1996struct ref_lock *lock;1997int last_errno =0;1998int lflags = LOCK_NO_DEREF;1999int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2000int resolve_flags = RESOLVE_REF_NO_RECURSE;2001int attempts_remaining =3;2002int resolved;20032004assert(err);20052006 lock =xcalloc(1,sizeof(struct ref_lock));20072008if(mustexist)2009 resolve_flags |= RESOLVE_REF_READING;2010if(flags & REF_DELETING)2011 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20122013strbuf_git_path(&ref_file,"%s", refname);2014 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2015 lock->old_oid.hash, type);2016if(!resolved && errno == EISDIR) {2017/*2018 * we are trying to lock foo but we used to2019 * have foo/bar which now does not exist;2020 * it is normal for the empty directory 'foo'2021 * to remain.2022 */2023if(remove_empty_directories(&ref_file)) {2024 last_errno = errno;2025if(!verify_refname_available_dir(2026 refname, extras, skip,2027get_loose_refs(refs), err))2028strbuf_addf(err,"there are still refs under '%s'",2029 refname);2030goto error_return;2031}2032 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2033 lock->old_oid.hash, type);2034}2035if(!resolved) {2036 last_errno = errno;2037if(last_errno != ENOTDIR ||2038!verify_refname_available_dir(2039 refname, extras, skip,2040get_loose_refs(refs), err))2041strbuf_addf(err,"unable to resolve reference '%s':%s",2042 refname,strerror(last_errno));20432044goto error_return;2045}20462047/*2048 * If the ref did not exist and we are creating it, make sure2049 * there is no existing packed ref whose name begins with our2050 * refname, nor a packed ref whose name is a proper prefix of2051 * our refname.2052 */2053if(is_null_oid(&lock->old_oid) &&2054verify_refname_available_dir(refname, extras, skip,2055get_packed_refs(refs),2056 err)) {2057 last_errno = ENOTDIR;2058goto error_return;2059}20602061 lock->lk =xcalloc(1,sizeof(struct lock_file));20622063 lock->ref_name =xstrdup(refname);20642065 retry:2066switch(safe_create_leading_directories_const(ref_file.buf)) {2067case SCLD_OK:2068break;/* success */2069case SCLD_VANISHED:2070if(--attempts_remaining >0)2071goto retry;2072/* fall through */2073default:2074 last_errno = errno;2075strbuf_addf(err,"unable to create directory for '%s'",2076 ref_file.buf);2077goto error_return;2078}20792080if(hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) <0) {2081 last_errno = errno;2082if(errno == ENOENT && --attempts_remaining >0)2083/*2084 * Maybe somebody just deleted one of the2085 * directories leading to ref_file. Try2086 * again:2087 */2088goto retry;2089else{2090unable_to_lock_message(ref_file.buf, errno, err);2091goto error_return;2092}2093}2094if(verify_lock(lock, old_sha1, mustexist, err)) {2095 last_errno = errno;2096goto error_return;2097}2098goto out;20992100 error_return:2101unlock_ref(lock);2102 lock = NULL;21032104 out:2105strbuf_release(&ref_file);2106 errno = last_errno;2107return lock;2108}21092110/*2111 * Write an entry to the packed-refs file for the specified refname.2112 * If peeled is non-NULL, write it as the entry's peeled value.2113 */2114static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2115unsigned char*peeled)2116{2117fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2118if(peeled)2119fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2120}21212122/*2123 * An each_ref_entry_fn that writes the entry to a packed-refs file.2124 */2125static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2126{2127enum peel_status peel_status =peel_entry(entry,0);21282129if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2130error("internal error:%sis not a valid packed reference!",2131 entry->name);2132write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2133 peel_status == PEEL_PEELED ?2134 entry->u.value.peeled.hash : NULL);2135return0;2136}21372138/*2139 * Lock the packed-refs file for writing. Flags is passed to2140 * hold_lock_file_for_update(). Return 0 on success. On errors, set2141 * errno appropriately and return a nonzero value.2142 */2143static intlock_packed_refs(struct files_ref_store *refs,int flags)2144{2145static int timeout_configured =0;2146static int timeout_value =1000;2147struct packed_ref_cache *packed_ref_cache;21482149assert_main_repository(&refs->base,"lock_packed_refs");21502151if(!timeout_configured) {2152git_config_get_int("core.packedrefstimeout", &timeout_value);2153 timeout_configured =1;2154}21552156if(hold_lock_file_for_update_timeout(2157&packlock,git_path("packed-refs"),2158 flags, timeout_value) <0)2159return-1;2160/*2161 * Get the current packed-refs while holding the lock. If the2162 * packed-refs file has been modified since we last read it,2163 * this will automatically invalidate the cache and re-read2164 * the packed-refs file.2165 */2166 packed_ref_cache =get_packed_ref_cache(refs);2167 packed_ref_cache->lock = &packlock;2168/* Increment the reference count to prevent it from being freed: */2169acquire_packed_ref_cache(packed_ref_cache);2170return0;2171}21722173/*2174 * Write the current version of the packed refs cache from memory to2175 * disk. The packed-refs file must already be locked for writing (see2176 * lock_packed_refs()). Return zero on success. On errors, set errno2177 * and return a nonzero value2178 */2179static intcommit_packed_refs(struct files_ref_store *refs)2180{2181struct packed_ref_cache *packed_ref_cache =2182get_packed_ref_cache(refs);2183int error =0;2184int save_errno =0;2185FILE*out;21862187assert_main_repository(&refs->base,"commit_packed_refs");21882189if(!packed_ref_cache->lock)2190die("internal error: packed-refs not locked");21912192 out =fdopen_lock_file(packed_ref_cache->lock,"w");2193if(!out)2194die_errno("unable to fdopen packed-refs descriptor");21952196fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2197do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),21980, write_packed_entry_fn, out);21992200if(commit_lock_file(packed_ref_cache->lock)) {2201 save_errno = errno;2202 error = -1;2203}2204 packed_ref_cache->lock = NULL;2205release_packed_ref_cache(packed_ref_cache);2206 errno = save_errno;2207return error;2208}22092210/*2211 * Rollback the lockfile for the packed-refs file, and discard the2212 * in-memory packed reference cache. (The packed-refs file will be2213 * read anew if it is needed again after this function is called.)2214 */2215static voidrollback_packed_refs(struct files_ref_store *refs)2216{2217struct packed_ref_cache *packed_ref_cache =2218get_packed_ref_cache(refs);22192220assert_main_repository(&refs->base,"rollback_packed_refs");22212222if(!packed_ref_cache->lock)2223die("internal error: packed-refs not locked");2224rollback_lock_file(packed_ref_cache->lock);2225 packed_ref_cache->lock = NULL;2226release_packed_ref_cache(packed_ref_cache);2227clear_packed_ref_cache(refs);2228}22292230struct ref_to_prune {2231struct ref_to_prune *next;2232unsigned char sha1[20];2233char name[FLEX_ARRAY];2234};22352236struct pack_refs_cb_data {2237unsigned int flags;2238struct ref_dir *packed_refs;2239struct ref_to_prune *ref_to_prune;2240};22412242/*2243 * An each_ref_entry_fn that is run over loose references only. If2244 * the loose reference can be packed, add an entry in the packed ref2245 * cache. If the reference should be pruned, also add it to2246 * ref_to_prune in the pack_refs_cb_data.2247 */2248static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2249{2250struct pack_refs_cb_data *cb = cb_data;2251enum peel_status peel_status;2252struct ref_entry *packed_entry;2253int is_tag_ref =starts_with(entry->name,"refs/tags/");22542255/* Do not pack per-worktree refs: */2256if(ref_type(entry->name) != REF_TYPE_NORMAL)2257return0;22582259/* ALWAYS pack tags */2260if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2261return0;22622263/* Do not pack symbolic or broken refs: */2264if((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2265return0;22662267/* Add a packed ref cache entry equivalent to the loose entry. */2268 peel_status =peel_entry(entry,1);2269if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2270die("internal error peeling reference%s(%s)",2271 entry->name,oid_to_hex(&entry->u.value.oid));2272 packed_entry =find_ref(cb->packed_refs, entry->name);2273if(packed_entry) {2274/* Overwrite existing packed entry with info from loose entry */2275 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2276oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2277}else{2278 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2279 REF_ISPACKED | REF_KNOWS_PEELED,0);2280add_ref(cb->packed_refs, packed_entry);2281}2282oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);22832284/* Schedule the loose reference for pruning if requested. */2285if((cb->flags & PACK_REFS_PRUNE)) {2286struct ref_to_prune *n;2287FLEX_ALLOC_STR(n, name, entry->name);2288hashcpy(n->sha1, entry->u.value.oid.hash);2289 n->next = cb->ref_to_prune;2290 cb->ref_to_prune = n;2291}2292return0;2293}22942295/*2296 * Remove empty parents, but spare refs/ and immediate subdirs.2297 * Note: munges *name.2298 */2299static voidtry_remove_empty_parents(char*name)2300{2301char*p, *q;2302int i;2303 p = name;2304for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2305while(*p && *p !='/')2306 p++;2307/* tolerate duplicate slashes; see check_refname_format() */2308while(*p =='/')2309 p++;2310}2311for(q = p; *q; q++)2312;2313while(1) {2314while(q > p && *q !='/')2315 q--;2316while(q > p && *(q-1) =='/')2317 q--;2318if(q == p)2319break;2320*q ='\0';2321if(rmdir(git_path("%s", name)))2322break;2323}2324}23252326/* make sure nobody touched the ref, and unlink */2327static voidprune_ref(struct ref_to_prune *r)2328{2329struct ref_transaction *transaction;2330struct strbuf err = STRBUF_INIT;23312332if(check_refname_format(r->name,0))2333return;23342335 transaction =ref_transaction_begin(&err);2336if(!transaction ||2337ref_transaction_delete(transaction, r->name, r->sha1,2338 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2339ref_transaction_commit(transaction, &err)) {2340ref_transaction_free(transaction);2341error("%s", err.buf);2342strbuf_release(&err);2343return;2344}2345ref_transaction_free(transaction);2346strbuf_release(&err);2347try_remove_empty_parents(r->name);2348}23492350static voidprune_refs(struct ref_to_prune *r)2351{2352while(r) {2353prune_ref(r);2354 r = r->next;2355}2356}23572358static intfiles_pack_refs(struct ref_store *ref_store,unsigned int flags)2359{2360struct files_ref_store *refs =2361files_downcast(ref_store,0,"pack_refs");2362struct pack_refs_cb_data cbdata;23632364memset(&cbdata,0,sizeof(cbdata));2365 cbdata.flags = flags;23662367lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2368 cbdata.packed_refs =get_packed_refs(refs);23692370do_for_each_entry_in_dir(get_loose_refs(refs),0,2371 pack_if_possible_fn, &cbdata);23722373if(commit_packed_refs(refs))2374die_errno("unable to overwrite old ref-pack file");23752376prune_refs(cbdata.ref_to_prune);2377return0;2378}23792380/*2381 * Rewrite the packed-refs file, omitting any refs listed in2382 * 'refnames'. On error, leave packed-refs unchanged, write an error2383 * message to 'err', and return a nonzero value.2384 *2385 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2386 */2387static intrepack_without_refs(struct files_ref_store *refs,2388struct string_list *refnames,struct strbuf *err)2389{2390struct ref_dir *packed;2391struct string_list_item *refname;2392int ret, needs_repacking =0, removed =0;23932394assert_main_repository(&refs->base,"repack_without_refs");2395assert(err);23962397/* Look for a packed ref */2398for_each_string_list_item(refname, refnames) {2399if(get_packed_ref(refs, refname->string)) {2400 needs_repacking =1;2401break;2402}2403}24042405/* Avoid locking if we have nothing to do */2406if(!needs_repacking)2407return0;/* no refname exists in packed refs */24082409if(lock_packed_refs(refs,0)) {2410unable_to_lock_message(git_path("packed-refs"), errno, err);2411return-1;2412}2413 packed =get_packed_refs(refs);24142415/* Remove refnames from the cache */2416for_each_string_list_item(refname, refnames)2417if(remove_entry(packed, refname->string) != -1)2418 removed =1;2419if(!removed) {2420/*2421 * All packed entries disappeared while we were2422 * acquiring the lock.2423 */2424rollback_packed_refs(refs);2425return0;2426}24272428/* Write what remains */2429 ret =commit_packed_refs(refs);2430if(ret)2431strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2432strerror(errno));2433return ret;2434}24352436static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2437{2438assert(err);24392440if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2441/*2442 * loose. The loose file name is the same as the2443 * lockfile name, minus ".lock":2444 */2445char*loose_filename =get_locked_file_path(lock->lk);2446int res =unlink_or_msg(loose_filename, err);2447free(loose_filename);2448if(res)2449return1;2450}2451return0;2452}24532454intdelete_refs(struct string_list *refnames,unsigned int flags)2455{2456struct files_ref_store *refs =2457get_files_ref_store(NULL,"delete_refs");2458struct strbuf err = STRBUF_INIT;2459int i, result =0;24602461if(!refnames->nr)2462return0;24632464 result =repack_without_refs(refs, refnames, &err);2465if(result) {2466/*2467 * If we failed to rewrite the packed-refs file, then2468 * it is unsafe to try to remove loose refs, because2469 * doing so might expose an obsolete packed value for2470 * a reference that might even point at an object that2471 * has been garbage collected.2472 */2473if(refnames->nr ==1)2474error(_("could not delete reference%s:%s"),2475 refnames->items[0].string, err.buf);2476else2477error(_("could not delete references:%s"), err.buf);24782479goto out;2480}24812482for(i =0; i < refnames->nr; i++) {2483const char*refname = refnames->items[i].string;24842485if(delete_ref(refname, NULL, flags))2486 result |=error(_("could not remove reference%s"), refname);2487}24882489out:2490strbuf_release(&err);2491return result;2492}24932494/*2495 * People using contrib's git-new-workdir have .git/logs/refs ->2496 * /some/other/path/.git/logs/refs, and that may live on another device.2497 *2498 * IOW, to avoid cross device rename errors, the temporary renamed log must2499 * live into logs/refs.2500 */2501#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"25022503static intrename_tmp_log(const char*newrefname)2504{2505int attempts_remaining =4;2506struct strbuf path = STRBUF_INIT;2507int ret = -1;25082509 retry:2510strbuf_reset(&path);2511strbuf_git_path(&path,"logs/%s", newrefname);2512switch(safe_create_leading_directories_const(path.buf)) {2513case SCLD_OK:2514break;/* success */2515case SCLD_VANISHED:2516if(--attempts_remaining >0)2517goto retry;2518/* fall through */2519default:2520error("unable to create directory for%s", newrefname);2521goto out;2522}25232524if(rename(git_path(TMP_RENAMED_LOG), path.buf)) {2525if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2526/*2527 * rename(a, b) when b is an existing2528 * directory ought to result in ISDIR, but2529 * Solaris 5.8 gives ENOTDIR. Sheesh.2530 */2531if(remove_empty_directories(&path)) {2532error("Directory not empty: logs/%s", newrefname);2533goto out;2534}2535goto retry;2536}else if(errno == ENOENT && --attempts_remaining >0) {2537/*2538 * Maybe another process just deleted one of2539 * the directories in the path to newrefname.2540 * Try again from the beginning.2541 */2542goto retry;2543}else{2544error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2545 newrefname,strerror(errno));2546goto out;2547}2548}2549 ret =0;2550out:2551strbuf_release(&path);2552return ret;2553}25542555static intfiles_verify_refname_available(struct ref_store *ref_store,2556const char*newname,2557const struct string_list *extras,2558const struct string_list *skip,2559struct strbuf *err)2560{2561struct files_ref_store *refs =2562files_downcast(ref_store,1,"verify_refname_available");2563struct ref_dir *packed_refs =get_packed_refs(refs);2564struct ref_dir *loose_refs =get_loose_refs(refs);25652566if(verify_refname_available_dir(newname, extras, skip,2567 packed_refs, err) ||2568verify_refname_available_dir(newname, extras, skip,2569 loose_refs, err))2570return-1;25712572return0;2573}25742575static intwrite_ref_to_lockfile(struct ref_lock *lock,2576const unsigned char*sha1,struct strbuf *err);2577static intcommit_ref_update(struct ref_lock *lock,2578const unsigned char*sha1,const char*logmsg,2579struct strbuf *err);25802581intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2582{2583unsigned char sha1[20], orig_sha1[20];2584int flag =0, logmoved =0;2585struct ref_lock *lock;2586struct stat loginfo;2587int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2588struct strbuf err = STRBUF_INIT;25892590if(log &&S_ISLNK(loginfo.st_mode))2591returnerror("reflog for%sis a symlink", oldrefname);25922593if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2594 orig_sha1, &flag))2595returnerror("refname%snot found", oldrefname);25962597if(flag & REF_ISSYMREF)2598returnerror("refname%sis a symbolic ref, renaming it is not supported",2599 oldrefname);2600if(!rename_ref_available(oldrefname, newrefname))2601return1;26022603if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2604returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2605 oldrefname,strerror(errno));26062607if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2608error("unable to delete old%s", oldrefname);2609goto rollback;2610}26112612/*2613 * Since we are doing a shallow lookup, sha1 is not the2614 * correct value to pass to delete_ref as old_sha1. But that2615 * doesn't matter, because an old_sha1 check wouldn't add to2616 * the safety anyway; we want to delete the reference whatever2617 * its current value.2618 */2619if(!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2620 sha1, NULL) &&2621delete_ref(newrefname, NULL, REF_NODEREF)) {2622if(errno==EISDIR) {2623struct strbuf path = STRBUF_INIT;2624int result;26252626strbuf_git_path(&path,"%s", newrefname);2627 result =remove_empty_directories(&path);2628strbuf_release(&path);26292630if(result) {2631error("Directory not empty:%s", newrefname);2632goto rollback;2633}2634}else{2635error("unable to delete existing%s", newrefname);2636goto rollback;2637}2638}26392640if(log &&rename_tmp_log(newrefname))2641goto rollback;26422643 logmoved = log;26442645 lock =lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,2646 NULL, &err);2647if(!lock) {2648error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2649strbuf_release(&err);2650goto rollback;2651}2652hashcpy(lock->old_oid.hash, orig_sha1);26532654if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2655commit_ref_update(lock, orig_sha1, logmsg, &err)) {2656error("unable to write current sha1 into%s:%s", newrefname, err.buf);2657strbuf_release(&err);2658goto rollback;2659}26602661return0;26622663 rollback:2664 lock =lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,2665 NULL, &err);2666if(!lock) {2667error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2668strbuf_release(&err);2669goto rollbacklog;2670}26712672 flag = log_all_ref_updates;2673 log_all_ref_updates =0;2674if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2675commit_ref_update(lock, orig_sha1, NULL, &err)) {2676error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2677strbuf_release(&err);2678}2679 log_all_ref_updates = flag;26802681 rollbacklog:2682if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2683error("unable to restore logfile%sfrom%s:%s",2684 oldrefname, newrefname,strerror(errno));2685if(!logmoved && log &&2686rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2687error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2688 oldrefname,strerror(errno));26892690return1;2691}26922693static intclose_ref(struct ref_lock *lock)2694{2695if(close_lock_file(lock->lk))2696return-1;2697return0;2698}26992700static intcommit_ref(struct ref_lock *lock)2701{2702char*path =get_locked_file_path(lock->lk);2703struct stat st;27042705if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2706/*2707 * There is a directory at the path we want to rename2708 * the lockfile to. Hopefully it is empty; try to2709 * delete it.2710 */2711size_t len =strlen(path);2712struct strbuf sb_path = STRBUF_INIT;27132714strbuf_attach(&sb_path, path, len, len);27152716/*2717 * If this fails, commit_lock_file() will also fail2718 * and will report the problem.2719 */2720remove_empty_directories(&sb_path);2721strbuf_release(&sb_path);2722}else{2723free(path);2724}27252726if(commit_lock_file(lock->lk))2727return-1;2728return0;2729}27302731/*2732 * Create a reflog for a ref. If force_create = 0, the reflog will2733 * only be created for certain refs (those for which2734 * should_autocreate_reflog returns non-zero. Otherwise, create it2735 * regardless of the ref name. Fill in *err and return -1 on failure.2736 */2737static intlog_ref_setup(const char*refname,struct strbuf *logfile,struct strbuf *err,int force_create)2738{2739int logfd, oflags = O_APPEND | O_WRONLY;27402741strbuf_git_path(logfile,"logs/%s", refname);2742if(force_create ||should_autocreate_reflog(refname)) {2743if(safe_create_leading_directories(logfile->buf) <0) {2744strbuf_addf(err,"unable to create directory for '%s': "2745"%s", logfile->buf,strerror(errno));2746return-1;2747}2748 oflags |= O_CREAT;2749}27502751 logfd =open(logfile->buf, oflags,0666);2752if(logfd <0) {2753if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2754return0;27552756if(errno == EISDIR) {2757if(remove_empty_directories(logfile)) {2758strbuf_addf(err,"there are still logs under "2759"'%s'", logfile->buf);2760return-1;2761}2762 logfd =open(logfile->buf, oflags,0666);2763}27642765if(logfd <0) {2766strbuf_addf(err,"unable to append to '%s':%s",2767 logfile->buf,strerror(errno));2768return-1;2769}2770}27712772adjust_shared_perm(logfile->buf);2773close(logfd);2774return0;2775}277627772778intsafe_create_reflog(const char*refname,int force_create,struct strbuf *err)2779{2780int ret;2781struct strbuf sb = STRBUF_INIT;27822783 ret =log_ref_setup(refname, &sb, err, force_create);2784strbuf_release(&sb);2785return ret;2786}27872788static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2789const unsigned char*new_sha1,2790const char*committer,const char*msg)2791{2792int msglen, written;2793unsigned maxlen, len;2794char*logrec;27952796 msglen = msg ?strlen(msg) :0;2797 maxlen =strlen(committer) + msglen +100;2798 logrec =xmalloc(maxlen);2799 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2800sha1_to_hex(old_sha1),2801sha1_to_hex(new_sha1),2802 committer);2803if(msglen)2804 len +=copy_reflog_msg(logrec + len -1, msg) -1;28052806 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2807free(logrec);2808if(written != len)2809return-1;28102811return0;2812}28132814static intlog_ref_write_1(const char*refname,const unsigned char*old_sha1,2815const unsigned char*new_sha1,const char*msg,2816struct strbuf *logfile,int flags,2817struct strbuf *err)2818{2819int logfd, result, oflags = O_APPEND | O_WRONLY;28202821if(log_all_ref_updates <0)2822 log_all_ref_updates = !is_bare_repository();28232824 result =log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);28252826if(result)2827return result;28282829 logfd =open(logfile->buf, oflags);2830if(logfd <0)2831return0;2832 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2833git_committer_info(0), msg);2834if(result) {2835strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2836strerror(errno));2837close(logfd);2838return-1;2839}2840if(close(logfd)) {2841strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2842strerror(errno));2843return-1;2844}2845return0;2846}28472848static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2849const unsigned char*new_sha1,const char*msg,2850int flags,struct strbuf *err)2851{2852returnfiles_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2853 err);2854}28552856intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1,2857const unsigned char*new_sha1,const char*msg,2858int flags,struct strbuf *err)2859{2860struct strbuf sb = STRBUF_INIT;2861int ret =log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2862 err);2863strbuf_release(&sb);2864return ret;2865}28662867/*2868 * Write sha1 into the open lockfile, then close the lockfile. On2869 * errors, rollback the lockfile, fill in *err and2870 * return -1.2871 */2872static intwrite_ref_to_lockfile(struct ref_lock *lock,2873const unsigned char*sha1,struct strbuf *err)2874{2875static char term ='\n';2876struct object *o;2877int fd;28782879 o =parse_object(sha1);2880if(!o) {2881strbuf_addf(err,2882"trying to write ref '%s' with nonexistent object%s",2883 lock->ref_name,sha1_to_hex(sha1));2884unlock_ref(lock);2885return-1;2886}2887if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2888strbuf_addf(err,2889"trying to write non-commit object%sto branch '%s'",2890sha1_to_hex(sha1), lock->ref_name);2891unlock_ref(lock);2892return-1;2893}2894 fd =get_lock_file_fd(lock->lk);2895if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2896write_in_full(fd, &term,1) !=1||2897close_ref(lock) <0) {2898strbuf_addf(err,2899"couldn't write '%s'",get_lock_file_path(lock->lk));2900unlock_ref(lock);2901return-1;2902}2903return0;2904}29052906/*2907 * Commit a change to a loose reference that has already been written2908 * to the loose reference lockfile. Also update the reflogs if2909 * necessary, using the specified lockmsg (which can be NULL).2910 */2911static intcommit_ref_update(struct ref_lock *lock,2912const unsigned char*sha1,const char*logmsg,2913struct strbuf *err)2914{2915struct files_ref_store *refs =2916get_files_ref_store(NULL,"commit_ref_update");29172918clear_loose_ref_cache(refs);2919if(log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg,0, err)) {2920char*old_msg =strbuf_detach(err, NULL);2921strbuf_addf(err,"cannot update the ref '%s':%s",2922 lock->ref_name, old_msg);2923free(old_msg);2924unlock_ref(lock);2925return-1;2926}29272928if(strcmp(lock->ref_name,"HEAD") !=0) {2929/*2930 * Special hack: If a branch is updated directly and HEAD2931 * points to it (may happen on the remote side of a push2932 * for example) then logically the HEAD reflog should be2933 * updated too.2934 * A generic solution implies reverse symref information,2935 * but finding all symrefs pointing to the given branch2936 * would be rather costly for this rare event (the direct2937 * update of a branch) to be worth it. So let's cheat and2938 * check with HEAD only which should cover 99% of all usage2939 * scenarios (even 100% of the default ones).2940 */2941unsigned char head_sha1[20];2942int head_flag;2943const char*head_ref;29442945 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2946 head_sha1, &head_flag);2947if(head_ref && (head_flag & REF_ISSYMREF) &&2948!strcmp(head_ref, lock->ref_name)) {2949struct strbuf log_err = STRBUF_INIT;2950if(log_ref_write("HEAD", lock->old_oid.hash, sha1,2951 logmsg,0, &log_err)) {2952error("%s", log_err.buf);2953strbuf_release(&log_err);2954}2955}2956}29572958if(commit_ref(lock)) {2959strbuf_addf(err,"couldn't set '%s'", lock->ref_name);2960unlock_ref(lock);2961return-1;2962}29632964unlock_ref(lock);2965return0;2966}29672968static intcreate_ref_symlink(struct ref_lock *lock,const char*target)2969{2970int ret = -1;2971#ifndef NO_SYMLINK_HEAD2972char*ref_path =get_locked_file_path(lock->lk);2973unlink(ref_path);2974 ret =symlink(target, ref_path);2975free(ref_path);29762977if(ret)2978fprintf(stderr,"no symlink - falling back to symbolic ref\n");2979#endif2980return ret;2981}29822983static voidupdate_symref_reflog(struct ref_lock *lock,const char*refname,2984const char*target,const char*logmsg)2985{2986struct strbuf err = STRBUF_INIT;2987unsigned char new_sha1[20];2988if(logmsg && !read_ref(target, new_sha1) &&2989log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg,0, &err)) {2990error("%s", err.buf);2991strbuf_release(&err);2992}2993}29942995static intcreate_symref_locked(struct ref_lock *lock,const char*refname,2996const char*target,const char*logmsg)2997{2998if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {2999update_symref_reflog(lock, refname, target, logmsg);3000return0;3001}30023003if(!fdopen_lock_file(lock->lk,"w"))3004returnerror("unable to fdopen%s:%s",3005 lock->lk->tempfile.filename.buf,strerror(errno));30063007update_symref_reflog(lock, refname, target, logmsg);30083009/* no error check; commit_ref will check ferror */3010fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);3011if(commit_ref(lock) <0)3012returnerror("unable to write symref for%s:%s", refname,3013strerror(errno));3014return0;3015}30163017static intfiles_create_symref(struct ref_store *ref_store,3018const char*refname,const char*target,3019const char*logmsg)3020{3021struct strbuf err = STRBUF_INIT;3022struct ref_lock *lock;3023int ret;30243025files_downcast(ref_store,0,"create_symref");30263027 lock =lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,3028&err);3029if(!lock) {3030error("%s", err.buf);3031strbuf_release(&err);3032return-1;3033}30343035 ret =create_symref_locked(lock, refname, target, logmsg);3036unlock_ref(lock);3037return ret;3038}30393040intset_worktree_head_symref(const char*gitdir,const char*target)3041{3042static struct lock_file head_lock;3043struct ref_lock *lock;3044struct strbuf head_path = STRBUF_INIT;3045const char*head_rel;3046int ret;30473048strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));3049if(hold_lock_file_for_update(&head_lock, head_path.buf,3050 LOCK_NO_DEREF) <0) {3051struct strbuf err = STRBUF_INIT;3052unable_to_lock_message(head_path.buf, errno, &err);3053error("%s", err.buf);3054strbuf_release(&err);3055strbuf_release(&head_path);3056return-1;3057}30583059/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3060 linked trees */3061 head_rel =remove_leading_path(head_path.buf,3062absolute_path(get_git_common_dir()));3063/* to make use of create_symref_locked(), initialize ref_lock */3064 lock =xcalloc(1,sizeof(struct ref_lock));3065 lock->lk = &head_lock;3066 lock->ref_name =xstrdup(head_rel);30673068 ret =create_symref_locked(lock, head_rel, target, NULL);30693070unlock_ref(lock);/* will free lock */3071strbuf_release(&head_path);3072return ret;3073}30743075intreflog_exists(const char*refname)3076{3077struct stat st;30783079return!lstat(git_path("logs/%s", refname), &st) &&3080S_ISREG(st.st_mode);3081}30823083intdelete_reflog(const char*refname)3084{3085returnremove_path(git_path("logs/%s", refname));3086}30873088static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3089{3090unsigned char osha1[20], nsha1[20];3091char*email_end, *message;3092unsigned long timestamp;3093int tz;30943095/* old SP new SP name <email> SP time TAB msg LF */3096if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3097get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3098get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3099!(email_end =strchr(sb->buf +82,'>')) ||3100 email_end[1] !=' '||3101!(timestamp =strtoul(email_end +2, &message,10)) ||3102!message || message[0] !=' '||3103(message[1] !='+'&& message[1] !='-') ||3104!isdigit(message[2]) || !isdigit(message[3]) ||3105!isdigit(message[4]) || !isdigit(message[5]))3106return0;/* corrupt? */3107 email_end[1] ='\0';3108 tz =strtol(message +1, NULL,10);3109if(message[6] !='\t')3110 message +=6;3111else3112 message +=7;3113returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3114}31153116static char*find_beginning_of_line(char*bob,char*scan)3117{3118while(bob < scan && *(--scan) !='\n')3119;/* keep scanning backwards */3120/*3121 * Return either beginning of the buffer, or LF at the end of3122 * the previous line.3123 */3124return scan;3125}31263127intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3128{3129struct strbuf sb = STRBUF_INIT;3130FILE*logfp;3131long pos;3132int ret =0, at_tail =1;31333134 logfp =fopen(git_path("logs/%s", refname),"r");3135if(!logfp)3136return-1;31373138/* Jump to the end */3139if(fseek(logfp,0, SEEK_END) <0)3140returnerror("cannot seek back reflog for%s:%s",3141 refname,strerror(errno));3142 pos =ftell(logfp);3143while(!ret &&0< pos) {3144int cnt;3145size_t nread;3146char buf[BUFSIZ];3147char*endp, *scanp;31483149/* Fill next block from the end */3150 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3151if(fseek(logfp, pos - cnt, SEEK_SET))3152returnerror("cannot seek back reflog for%s:%s",3153 refname,strerror(errno));3154 nread =fread(buf, cnt,1, logfp);3155if(nread !=1)3156returnerror("cannot read%dbytes from reflog for%s:%s",3157 cnt, refname,strerror(errno));3158 pos -= cnt;31593160 scanp = endp = buf + cnt;3161if(at_tail && scanp[-1] =='\n')3162/* Looking at the final LF at the end of the file */3163 scanp--;3164 at_tail =0;31653166while(buf < scanp) {3167/*3168 * terminating LF of the previous line, or the beginning3169 * of the buffer.3170 */3171char*bp;31723173 bp =find_beginning_of_line(buf, scanp);31743175if(*bp =='\n') {3176/*3177 * The newline is the end of the previous line,3178 * so we know we have complete line starting3179 * at (bp + 1). Prefix it onto any prior data3180 * we collected for the line and process it.3181 */3182strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3183 scanp = bp;3184 endp = bp +1;3185 ret =show_one_reflog_ent(&sb, fn, cb_data);3186strbuf_reset(&sb);3187if(ret)3188break;3189}else if(!pos) {3190/*3191 * We are at the start of the buffer, and the3192 * start of the file; there is no previous3193 * line, and we have everything for this one.3194 * Process it, and we can end the loop.3195 */3196strbuf_splice(&sb,0,0, buf, endp - buf);3197 ret =show_one_reflog_ent(&sb, fn, cb_data);3198strbuf_reset(&sb);3199break;3200}32013202if(bp == buf) {3203/*3204 * We are at the start of the buffer, and there3205 * is more file to read backwards. Which means3206 * we are in the middle of a line. Note that we3207 * may get here even if *bp was a newline; that3208 * just means we are at the exact end of the3209 * previous line, rather than some spot in the3210 * middle.3211 *3212 * Save away what we have to be combined with3213 * the data from the next read.3214 */3215strbuf_splice(&sb,0,0, buf, endp - buf);3216break;3217}3218}32193220}3221if(!ret && sb.len)3222die("BUG: reverse reflog parser had leftover data");32233224fclose(logfp);3225strbuf_release(&sb);3226return ret;3227}32283229intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3230{3231FILE*logfp;3232struct strbuf sb = STRBUF_INIT;3233int ret =0;32343235 logfp =fopen(git_path("logs/%s", refname),"r");3236if(!logfp)3237return-1;32383239while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3240 ret =show_one_reflog_ent(&sb, fn, cb_data);3241fclose(logfp);3242strbuf_release(&sb);3243return ret;3244}32453246struct files_reflog_iterator {3247struct ref_iterator base;32483249struct dir_iterator *dir_iterator;3250struct object_id oid;3251};32523253static intfiles_reflog_iterator_advance(struct ref_iterator *ref_iterator)3254{3255struct files_reflog_iterator *iter =3256(struct files_reflog_iterator *)ref_iterator;3257struct dir_iterator *diter = iter->dir_iterator;3258int ok;32593260while((ok =dir_iterator_advance(diter)) == ITER_OK) {3261int flags;32623263if(!S_ISREG(diter->st.st_mode))3264continue;3265if(diter->basename[0] =='.')3266continue;3267if(ends_with(diter->basename,".lock"))3268continue;32693270if(read_ref_full(diter->relative_path,0,3271 iter->oid.hash, &flags)) {3272error("bad ref for%s", diter->path.buf);3273continue;3274}32753276 iter->base.refname = diter->relative_path;3277 iter->base.oid = &iter->oid;3278 iter->base.flags = flags;3279return ITER_OK;3280}32813282 iter->dir_iterator = NULL;3283if(ref_iterator_abort(ref_iterator) == ITER_ERROR)3284 ok = ITER_ERROR;3285return ok;3286}32873288static intfiles_reflog_iterator_peel(struct ref_iterator *ref_iterator,3289struct object_id *peeled)3290{3291die("BUG: ref_iterator_peel() called for reflog_iterator");3292}32933294static intfiles_reflog_iterator_abort(struct ref_iterator *ref_iterator)3295{3296struct files_reflog_iterator *iter =3297(struct files_reflog_iterator *)ref_iterator;3298int ok = ITER_DONE;32993300if(iter->dir_iterator)3301 ok =dir_iterator_abort(iter->dir_iterator);33023303base_ref_iterator_free(ref_iterator);3304return ok;3305}33063307static struct ref_iterator_vtable files_reflog_iterator_vtable = {3308 files_reflog_iterator_advance,3309 files_reflog_iterator_peel,3310 files_reflog_iterator_abort3311};33123313struct ref_iterator *files_reflog_iterator_begin(void)3314{3315struct files_reflog_iterator *iter =xcalloc(1,sizeof(*iter));3316struct ref_iterator *ref_iterator = &iter->base;33173318base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3319 iter->dir_iterator =dir_iterator_begin(git_path("logs"));3320return ref_iterator;3321}33223323intfor_each_reflog(each_ref_fn fn,void*cb_data)3324{3325returndo_for_each_ref_iterator(files_reflog_iterator_begin(),3326 fn, cb_data);3327}33283329static intref_update_reject_duplicates(struct string_list *refnames,3330struct strbuf *err)3331{3332int i, n = refnames->nr;33333334assert(err);33353336for(i =1; i < n; i++)3337if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3338strbuf_addf(err,3339"multiple updates for ref '%s' not allowed.",3340 refnames->items[i].string);3341return1;3342}3343return0;3344}33453346/*3347 * If update is a direct update of head_ref (the reference pointed to3348 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3349 */3350static intsplit_head_update(struct ref_update *update,3351struct ref_transaction *transaction,3352const char*head_ref,3353struct string_list *affected_refnames,3354struct strbuf *err)3355{3356struct string_list_item *item;3357struct ref_update *new_update;33583359if((update->flags & REF_LOG_ONLY) ||3360(update->flags & REF_ISPRUNING) ||3361(update->flags & REF_UPDATE_VIA_HEAD))3362return0;33633364if(strcmp(update->refname, head_ref))3365return0;33663367/*3368 * First make sure that HEAD is not already in the3369 * transaction. This insertion is O(N) in the transaction3370 * size, but it happens at most once per transaction.3371 */3372 item =string_list_insert(affected_refnames,"HEAD");3373if(item->util) {3374/* An entry already existed */3375strbuf_addf(err,3376"multiple updates for 'HEAD' (including one "3377"via its referent '%s') are not allowed",3378 update->refname);3379return TRANSACTION_NAME_CONFLICT;3380}33813382 new_update =ref_transaction_add_update(3383 transaction,"HEAD",3384 update->flags | REF_LOG_ONLY | REF_NODEREF,3385 update->new_sha1, update->old_sha1,3386 update->msg);33873388 item->util = new_update;33893390return0;3391}33923393/*3394 * update is for a symref that points at referent and doesn't have3395 * REF_NODEREF set. Split it into two updates:3396 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3397 * - A new, separate update for the referent reference3398 * Note that the new update will itself be subject to splitting when3399 * the iteration gets to it.3400 */3401static intsplit_symref_update(struct ref_update *update,3402const char*referent,3403struct ref_transaction *transaction,3404struct string_list *affected_refnames,3405struct strbuf *err)3406{3407struct string_list_item *item;3408struct ref_update *new_update;3409unsigned int new_flags;34103411/*3412 * First make sure that referent is not already in the3413 * transaction. This insertion is O(N) in the transaction3414 * size, but it happens at most once per symref in a3415 * transaction.3416 */3417 item =string_list_insert(affected_refnames, referent);3418if(item->util) {3419/* An entry already existed */3420strbuf_addf(err,3421"multiple updates for '%s' (including one "3422"via symref '%s') are not allowed",3423 referent, update->refname);3424return TRANSACTION_NAME_CONFLICT;3425}34263427 new_flags = update->flags;3428if(!strcmp(update->refname,"HEAD")) {3429/*3430 * Record that the new update came via HEAD, so that3431 * when we process it, split_head_update() doesn't try3432 * to add another reflog update for HEAD. Note that3433 * this bit will be propagated if the new_update3434 * itself needs to be split.3435 */3436 new_flags |= REF_UPDATE_VIA_HEAD;3437}34383439 new_update =ref_transaction_add_update(3440 transaction, referent, new_flags,3441 update->new_sha1, update->old_sha1,3442 update->msg);34433444 new_update->parent_update = update;34453446/*3447 * Change the symbolic ref update to log only. Also, it3448 * doesn't need to check its old SHA-1 value, as that will be3449 * done when new_update is processed.3450 */3451 update->flags |= REF_LOG_ONLY | REF_NODEREF;3452 update->flags &= ~REF_HAVE_OLD;34533454 item->util = new_update;34553456return0;3457}34583459/*3460 * Return the refname under which update was originally requested.3461 */3462static const char*original_update_refname(struct ref_update *update)3463{3464while(update->parent_update)3465 update = update->parent_update;34663467return update->refname;3468}34693470/*3471 * Prepare for carrying out update:3472 * - Lock the reference referred to by update.3473 * - Read the reference under lock.3474 * - Check that its old SHA-1 value (if specified) is correct, and in3475 * any case record it in update->lock->old_oid for later use when3476 * writing the reflog.3477 * - If it is a symref update without REF_NODEREF, split it up into a3478 * REF_LOG_ONLY update of the symref and add a separate update for3479 * the referent to transaction.3480 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3481 * update of HEAD.3482 */3483static intlock_ref_for_update(struct ref_update *update,3484struct ref_transaction *transaction,3485const char*head_ref,3486struct string_list *affected_refnames,3487struct strbuf *err)3488{3489struct files_ref_store *refs =3490get_files_ref_store(NULL,"lock_ref_for_update");3491struct strbuf referent = STRBUF_INIT;3492int mustexist = (update->flags & REF_HAVE_OLD) &&3493!is_null_sha1(update->old_sha1);3494int ret;3495struct ref_lock *lock;34963497if((update->flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3498 update->flags |= REF_DELETING;34993500if(head_ref) {3501 ret =split_head_update(update, transaction, head_ref,3502 affected_refnames, err);3503if(ret)3504return ret;3505}35063507 ret =lock_raw_ref(refs, update->refname, mustexist,3508 affected_refnames, NULL,3509&update->lock, &referent,3510&update->type, err);35113512if(ret) {3513char*reason;35143515 reason =strbuf_detach(err, NULL);3516strbuf_addf(err,"cannot lock ref '%s':%s",3517 update->refname, reason);3518free(reason);3519return ret;3520}35213522 lock = update->lock;35233524if(update->type & REF_ISSYMREF) {3525if(update->flags & REF_NODEREF) {3526/*3527 * We won't be reading the referent as part of3528 * the transaction, so we have to read it here3529 * to record and possibly check old_sha1:3530 */3531if(read_ref_full(update->refname,3532 mustexist ? RESOLVE_REF_READING :0,3533 lock->old_oid.hash, NULL)) {3534if(update->flags & REF_HAVE_OLD) {3535strbuf_addf(err,"cannot lock ref '%s': "3536"can't resolve old value",3537 update->refname);3538return TRANSACTION_GENERIC_ERROR;3539}else{3540hashclr(lock->old_oid.hash);3541}3542}3543if((update->flags & REF_HAVE_OLD) &&3544hashcmp(lock->old_oid.hash, update->old_sha1)) {3545strbuf_addf(err,"cannot lock ref '%s': "3546"is at%sbut expected%s",3547 update->refname,3548sha1_to_hex(lock->old_oid.hash),3549sha1_to_hex(update->old_sha1));3550return TRANSACTION_GENERIC_ERROR;3551}35523553}else{3554/*3555 * Create a new update for the reference this3556 * symref is pointing at. Also, we will record3557 * and verify old_sha1 for this update as part3558 * of processing the split-off update, so we3559 * don't have to do it here.3560 */3561 ret =split_symref_update(update, referent.buf, transaction,3562 affected_refnames, err);3563if(ret)3564return ret;3565}3566}else{3567struct ref_update *parent_update;35683569/*3570 * If this update is happening indirectly because of a3571 * symref update, record the old SHA-1 in the parent3572 * update:3573 */3574for(parent_update = update->parent_update;3575 parent_update;3576 parent_update = parent_update->parent_update) {3577oidcpy(&parent_update->lock->old_oid, &lock->old_oid);3578}35793580if((update->flags & REF_HAVE_OLD) &&3581hashcmp(lock->old_oid.hash, update->old_sha1)) {3582if(is_null_sha1(update->old_sha1))3583strbuf_addf(err,"cannot lock ref '%s': reference already exists",3584original_update_refname(update));3585else3586strbuf_addf(err,"cannot lock ref '%s': is at%sbut expected%s",3587original_update_refname(update),3588sha1_to_hex(lock->old_oid.hash),3589sha1_to_hex(update->old_sha1));35903591return TRANSACTION_GENERIC_ERROR;3592}3593}35943595if((update->flags & REF_HAVE_NEW) &&3596!(update->flags & REF_DELETING) &&3597!(update->flags & REF_LOG_ONLY)) {3598if(!(update->type & REF_ISSYMREF) &&3599!hashcmp(lock->old_oid.hash, update->new_sha1)) {3600/*3601 * The reference already has the desired3602 * value, so we don't need to write it.3603 */3604}else if(write_ref_to_lockfile(lock, update->new_sha1,3605 err)) {3606char*write_err =strbuf_detach(err, NULL);36073608/*3609 * The lock was freed upon failure of3610 * write_ref_to_lockfile():3611 */3612 update->lock = NULL;3613strbuf_addf(err,3614"cannot update the ref '%s':%s",3615 update->refname, write_err);3616free(write_err);3617return TRANSACTION_GENERIC_ERROR;3618}else{3619 update->flags |= REF_NEEDS_COMMIT;3620}3621}3622if(!(update->flags & REF_NEEDS_COMMIT)) {3623/*3624 * We didn't call write_ref_to_lockfile(), so3625 * the lockfile is still open. Close it to3626 * free up the file descriptor:3627 */3628if(close_ref(lock)) {3629strbuf_addf(err,"couldn't close '%s.lock'",3630 update->refname);3631return TRANSACTION_GENERIC_ERROR;3632}3633}3634return0;3635}36363637static intfiles_transaction_commit(struct ref_store *ref_store,3638struct ref_transaction *transaction,3639struct strbuf *err)3640{3641struct files_ref_store *refs =3642files_downcast(ref_store,0,"ref_transaction_commit");3643int ret =0, i;3644struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3645struct string_list_item *ref_to_delete;3646struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3647char*head_ref = NULL;3648int head_type;3649struct object_id head_oid;36503651assert(err);36523653if(transaction->state != REF_TRANSACTION_OPEN)3654die("BUG: commit called for transaction that is not open");36553656if(!transaction->nr) {3657 transaction->state = REF_TRANSACTION_CLOSED;3658return0;3659}36603661/*3662 * Fail if a refname appears more than once in the3663 * transaction. (If we end up splitting up any updates using3664 * split_symref_update() or split_head_update(), those3665 * functions will check that the new updates don't have the3666 * same refname as any existing ones.)3667 */3668for(i =0; i < transaction->nr; i++) {3669struct ref_update *update = transaction->updates[i];3670struct string_list_item *item =3671string_list_append(&affected_refnames, update->refname);36723673/*3674 * We store a pointer to update in item->util, but at3675 * the moment we never use the value of this field3676 * except to check whether it is non-NULL.3677 */3678 item->util = update;3679}3680string_list_sort(&affected_refnames);3681if(ref_update_reject_duplicates(&affected_refnames, err)) {3682 ret = TRANSACTION_GENERIC_ERROR;3683goto cleanup;3684}36853686/*3687 * Special hack: If a branch is updated directly and HEAD3688 * points to it (may happen on the remote side of a push3689 * for example) then logically the HEAD reflog should be3690 * updated too.3691 *3692 * A generic solution would require reverse symref lookups,3693 * but finding all symrefs pointing to a given branch would be3694 * rather costly for this rare event (the direct update of a3695 * branch) to be worth it. So let's cheat and check with HEAD3696 * only, which should cover 99% of all usage scenarios (even3697 * 100% of the default ones).3698 *3699 * So if HEAD is a symbolic reference, then record the name of3700 * the reference that it points to. If we see an update of3701 * head_ref within the transaction, then split_head_update()3702 * arranges for the reflog of HEAD to be updated, too.3703 */3704 head_ref =resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3705 head_oid.hash, &head_type);37063707if(head_ref && !(head_type & REF_ISSYMREF)) {3708free(head_ref);3709 head_ref = NULL;3710}37113712/*3713 * Acquire all locks, verify old values if provided, check3714 * that new values are valid, and write new values to the3715 * lockfiles, ready to be activated. Only keep one lockfile3716 * open at a time to avoid running out of file descriptors.3717 */3718for(i =0; i < transaction->nr; i++) {3719struct ref_update *update = transaction->updates[i];37203721 ret =lock_ref_for_update(update, transaction, head_ref,3722&affected_refnames, err);3723if(ret)3724goto cleanup;3725}37263727/* Perform updates first so live commits remain referenced */3728for(i =0; i < transaction->nr; i++) {3729struct ref_update *update = transaction->updates[i];3730struct ref_lock *lock = update->lock;37313732if(update->flags & REF_NEEDS_COMMIT ||3733 update->flags & REF_LOG_ONLY) {3734if(log_ref_write(lock->ref_name, lock->old_oid.hash,3735 update->new_sha1,3736 update->msg, update->flags, err)) {3737char*old_msg =strbuf_detach(err, NULL);37383739strbuf_addf(err,"cannot update the ref '%s':%s",3740 lock->ref_name, old_msg);3741free(old_msg);3742unlock_ref(lock);3743 update->lock = NULL;3744 ret = TRANSACTION_GENERIC_ERROR;3745goto cleanup;3746}3747}3748if(update->flags & REF_NEEDS_COMMIT) {3749clear_loose_ref_cache(refs);3750if(commit_ref(lock)) {3751strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3752unlock_ref(lock);3753 update->lock = NULL;3754 ret = TRANSACTION_GENERIC_ERROR;3755goto cleanup;3756}3757}3758}3759/* Perform deletes now that updates are safely completed */3760for(i =0; i < transaction->nr; i++) {3761struct ref_update *update = transaction->updates[i];37623763if(update->flags & REF_DELETING &&3764!(update->flags & REF_LOG_ONLY)) {3765if(delete_ref_loose(update->lock, update->type, err)) {3766 ret = TRANSACTION_GENERIC_ERROR;3767goto cleanup;3768}37693770if(!(update->flags & REF_ISPRUNING))3771string_list_append(&refs_to_delete,3772 update->lock->ref_name);3773}3774}37753776if(repack_without_refs(refs, &refs_to_delete, err)) {3777 ret = TRANSACTION_GENERIC_ERROR;3778goto cleanup;3779}3780for_each_string_list_item(ref_to_delete, &refs_to_delete)3781unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3782clear_loose_ref_cache(refs);37833784cleanup:3785 transaction->state = REF_TRANSACTION_CLOSED;37863787for(i =0; i < transaction->nr; i++)3788if(transaction->updates[i]->lock)3789unlock_ref(transaction->updates[i]->lock);3790string_list_clear(&refs_to_delete,0);3791free(head_ref);3792string_list_clear(&affected_refnames,0);37933794return ret;3795}37963797static intref_present(const char*refname,3798const struct object_id *oid,int flags,void*cb_data)3799{3800struct string_list *affected_refnames = cb_data;38013802returnstring_list_has_string(affected_refnames, refname);3803}38043805intinitial_ref_transaction_commit(struct ref_transaction *transaction,3806struct strbuf *err)3807{3808struct files_ref_store *refs =3809get_files_ref_store(NULL,"initial_ref_transaction_commit");3810int ret =0, i;3811struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38123813assert(err);38143815if(transaction->state != REF_TRANSACTION_OPEN)3816die("BUG: commit called for transaction that is not open");38173818/* Fail if a refname appears more than once in the transaction: */3819for(i =0; i < transaction->nr; i++)3820string_list_append(&affected_refnames,3821 transaction->updates[i]->refname);3822string_list_sort(&affected_refnames);3823if(ref_update_reject_duplicates(&affected_refnames, err)) {3824 ret = TRANSACTION_GENERIC_ERROR;3825goto cleanup;3826}38273828/*3829 * It's really undefined to call this function in an active3830 * repository or when there are existing references: we are3831 * only locking and changing packed-refs, so (1) any3832 * simultaneous processes might try to change a reference at3833 * the same time we do, and (2) any existing loose versions of3834 * the references that we are setting would have precedence3835 * over our values. But some remote helpers create the remote3836 * "HEAD" and "master" branches before calling this function,3837 * so here we really only check that none of the references3838 * that we are creating already exists.3839 */3840if(for_each_rawref(ref_present, &affected_refnames))3841die("BUG: initial ref transaction called with existing refs");38423843for(i =0; i < transaction->nr; i++) {3844struct ref_update *update = transaction->updates[i];38453846if((update->flags & REF_HAVE_OLD) &&3847!is_null_sha1(update->old_sha1))3848die("BUG: initial ref transaction with old_sha1 set");3849if(verify_refname_available(update->refname,3850&affected_refnames, NULL,3851 err)) {3852 ret = TRANSACTION_NAME_CONFLICT;3853goto cleanup;3854}3855}38563857if(lock_packed_refs(refs,0)) {3858strbuf_addf(err,"unable to lock packed-refs file:%s",3859strerror(errno));3860 ret = TRANSACTION_GENERIC_ERROR;3861goto cleanup;3862}38633864for(i =0; i < transaction->nr; i++) {3865struct ref_update *update = transaction->updates[i];38663867if((update->flags & REF_HAVE_NEW) &&3868!is_null_sha1(update->new_sha1))3869add_packed_ref(refs, update->refname, update->new_sha1);3870}38713872if(commit_packed_refs(refs)) {3873strbuf_addf(err,"unable to commit packed-refs file:%s",3874strerror(errno));3875 ret = TRANSACTION_GENERIC_ERROR;3876goto cleanup;3877}38783879cleanup:3880 transaction->state = REF_TRANSACTION_CLOSED;3881string_list_clear(&affected_refnames,0);3882return ret;3883}38843885struct expire_reflog_cb {3886unsigned int flags;3887 reflog_expiry_should_prune_fn *should_prune_fn;3888void*policy_cb;3889FILE*newlog;3890unsigned char last_kept_sha1[20];3891};38923893static intexpire_reflog_ent(unsigned char*osha1,unsigned char*nsha1,3894const char*email,unsigned long timestamp,int tz,3895const char*message,void*cb_data)3896{3897struct expire_reflog_cb *cb = cb_data;3898struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;38993900if(cb->flags & EXPIRE_REFLOGS_REWRITE)3901 osha1 = cb->last_kept_sha1;39023903if((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3904 message, policy_cb)) {3905if(!cb->newlog)3906printf("would prune%s", message);3907else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3908printf("prune%s", message);3909}else{3910if(cb->newlog) {3911fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",3912sha1_to_hex(osha1),sha1_to_hex(nsha1),3913 email, timestamp, tz, message);3914hashcpy(cb->last_kept_sha1, nsha1);3915}3916if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3917printf("keep%s", message);3918}3919return0;3920}39213922intreflog_expire(const char*refname,const unsigned char*sha1,3923unsigned int flags,3924 reflog_expiry_prepare_fn prepare_fn,3925 reflog_expiry_should_prune_fn should_prune_fn,3926 reflog_expiry_cleanup_fn cleanup_fn,3927void*policy_cb_data)3928{3929static struct lock_file reflog_lock;3930struct expire_reflog_cb cb;3931struct ref_lock *lock;3932char*log_file;3933int status =0;3934int type;3935struct strbuf err = STRBUF_INIT;39363937memset(&cb,0,sizeof(cb));3938 cb.flags = flags;3939 cb.policy_cb = policy_cb_data;3940 cb.should_prune_fn = should_prune_fn;39413942/*3943 * The reflog file is locked by holding the lock on the3944 * reference itself, plus we might need to update the3945 * reference if --updateref was specified:3946 */3947 lock =lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF,3948&type, &err);3949if(!lock) {3950error("cannot lock ref '%s':%s", refname, err.buf);3951strbuf_release(&err);3952return-1;3953}3954if(!reflog_exists(refname)) {3955unlock_ref(lock);3956return0;3957}39583959 log_file =git_pathdup("logs/%s", refname);3960if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3961/*3962 * Even though holding $GIT_DIR/logs/$reflog.lock has3963 * no locking implications, we use the lock_file3964 * machinery here anyway because it does a lot of the3965 * work we need, including cleaning up if the program3966 * exits unexpectedly.3967 */3968if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {3969struct strbuf err = STRBUF_INIT;3970unable_to_lock_message(log_file, errno, &err);3971error("%s", err.buf);3972strbuf_release(&err);3973goto failure;3974}3975 cb.newlog =fdopen_lock_file(&reflog_lock,"w");3976if(!cb.newlog) {3977error("cannot fdopen%s(%s)",3978get_lock_file_path(&reflog_lock),strerror(errno));3979goto failure;3980}3981}39823983(*prepare_fn)(refname, sha1, cb.policy_cb);3984for_each_reflog_ent(refname, expire_reflog_ent, &cb);3985(*cleanup_fn)(cb.policy_cb);39863987if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3988/*3989 * It doesn't make sense to adjust a reference pointed3990 * to by a symbolic ref based on expiring entries in3991 * the symbolic reference's reflog. Nor can we update3992 * a reference if there are no remaining reflog3993 * entries.3994 */3995int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3996!(type & REF_ISSYMREF) &&3997!is_null_sha1(cb.last_kept_sha1);39983999if(close_lock_file(&reflog_lock)) {4000 status |=error("couldn't write%s:%s", log_file,4001strerror(errno));4002}else if(update &&4003(write_in_full(get_lock_file_fd(lock->lk),4004sha1_to_hex(cb.last_kept_sha1),40) !=40||4005write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||4006close_ref(lock) <0)) {4007 status |=error("couldn't write%s",4008get_lock_file_path(lock->lk));4009rollback_lock_file(&reflog_lock);4010}else if(commit_lock_file(&reflog_lock)) {4011 status |=error("unable to write reflog '%s' (%s)",4012 log_file,strerror(errno));4013}else if(update &&commit_ref(lock)) {4014 status |=error("couldn't set%s", lock->ref_name);4015}4016}4017free(log_file);4018unlock_ref(lock);4019return status;40204021 failure:4022rollback_lock_file(&reflog_lock);4023free(log_file);4024unlock_ref(lock);4025return-1;4026}40274028struct ref_storage_be refs_be_files = {4029 NULL,4030"files",4031 files_ref_store_create,4032 files_transaction_commit,40334034 files_pack_refs,4035 files_peel_ref,4036 files_create_symref,40374038 files_read_raw_ref,4039 files_verify_refname_available4040};