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#define MAXREFLEN (1024)13201321/*1322 * Called by resolve_gitlink_ref_recursive() after it failed to read1323 * from the loose refs in refs. Find <refname> in the packed-refs file1324 * for the submodule.1325 */1326static intresolve_gitlink_packed_ref(struct files_ref_store *refs,1327const char*refname,unsigned char*sha1)1328{1329struct ref_entry *ref;1330struct ref_dir *dir =get_packed_refs(refs);13311332 ref =find_ref(dir, refname);1333if(ref == NULL)1334return-1;13351336hashcpy(sha1, ref->u.value.oid.hash);1337return0;1338}13391340static intresolve_gitlink_ref_recursive(struct files_ref_store *refs,1341const char*refname,unsigned char*sha1,1342int recursion)1343{1344int fd, len;1345char buffer[128], *p;1346char*path;13471348if(recursion > SYMREF_MAXDEPTH ||strlen(refname) > MAXREFLEN)1349return-1;1350 path = *refs->base.submodule1351?git_pathdup_submodule(refs->base.submodule,"%s", refname)1352:git_pathdup("%s", refname);1353 fd =open(path, O_RDONLY);1354free(path);1355if(fd <0)1356returnresolve_gitlink_packed_ref(refs, refname, sha1);13571358 len =read(fd, buffer,sizeof(buffer)-1);1359close(fd);1360if(len <0)1361return-1;1362while(len &&isspace(buffer[len-1]))1363 len--;1364 buffer[len] =0;13651366/* Was it a detached head or an old-fashioned symlink? */1367if(!get_sha1_hex(buffer, sha1))1368return0;13691370/* Symref? */1371if(strncmp(buffer,"ref:",4))1372return-1;1373 p = buffer +4;1374while(isspace(*p))1375 p++;13761377returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1378}13791380intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1381{1382int len =strlen(path);1383struct strbuf submodule = STRBUF_INIT;1384struct files_ref_store *refs;13851386while(len && path[len-1] =='/')1387 len--;1388if(!len)1389return-1;13901391strbuf_add(&submodule, path, len);1392 refs =get_files_ref_store(submodule.buf,"resolve_gitlink_ref");1393if(!refs) {1394strbuf_release(&submodule);1395return-1;1396}1397strbuf_release(&submodule);13981399returnresolve_gitlink_ref_recursive(refs, refname, sha1,0);1400}14011402/*1403 * Return the ref_entry for the given refname from the packed1404 * references. If it does not exist, return NULL.1405 */1406static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1407const char*refname)1408{1409returnfind_ref(get_packed_refs(refs), refname);1410}14111412/*1413 * A loose ref file doesn't exist; check for a packed ref.1414 */1415static intresolve_missing_loose_ref(struct files_ref_store *refs,1416const char*refname,1417unsigned char*sha1,1418unsigned int*flags)1419{1420struct ref_entry *entry;14211422/*1423 * The loose reference file does not exist; check for a packed1424 * reference.1425 */1426 entry =get_packed_ref(refs, refname);1427if(entry) {1428hashcpy(sha1, entry->u.value.oid.hash);1429*flags |= REF_ISPACKED;1430return0;1431}1432/* refname is not a packed reference. */1433return-1;1434}14351436intread_raw_ref(const char*refname,unsigned char*sha1,1437struct strbuf *referent,unsigned int*type)1438{1439struct files_ref_store *refs =1440get_files_ref_store(NULL,"read_raw_ref");1441struct strbuf sb_contents = STRBUF_INIT;1442struct strbuf sb_path = STRBUF_INIT;1443const char*path;1444const char*buf;1445struct stat st;1446int fd;1447int ret = -1;1448int save_errno;14491450*type =0;1451strbuf_reset(&sb_path);1452strbuf_git_path(&sb_path,"%s", refname);1453 path = sb_path.buf;14541455stat_ref:1456/*1457 * We might have to loop back here to avoid a race1458 * condition: first we lstat() the file, then we try1459 * to read it as a link or as a file. But if somebody1460 * changes the type of the file (file <-> directory1461 * <-> symlink) between the lstat() and reading, then1462 * we don't want to report that as an error but rather1463 * try again starting with the lstat().1464 */14651466if(lstat(path, &st) <0) {1467if(errno != ENOENT)1468goto out;1469if(resolve_missing_loose_ref(refs, refname, sha1, type)) {1470 errno = ENOENT;1471goto out;1472}1473 ret =0;1474goto out;1475}14761477/* Follow "normalized" - ie "refs/.." symlinks by hand */1478if(S_ISLNK(st.st_mode)) {1479strbuf_reset(&sb_contents);1480if(strbuf_readlink(&sb_contents, path,0) <0) {1481if(errno == ENOENT || errno == EINVAL)1482/* inconsistent with lstat; retry */1483goto stat_ref;1484else1485goto out;1486}1487if(starts_with(sb_contents.buf,"refs/") &&1488!check_refname_format(sb_contents.buf,0)) {1489strbuf_swap(&sb_contents, referent);1490*type |= REF_ISSYMREF;1491 ret =0;1492goto out;1493}1494}14951496/* Is it a directory? */1497if(S_ISDIR(st.st_mode)) {1498/*1499 * Even though there is a directory where the loose1500 * ref is supposed to be, there could still be a1501 * packed ref:1502 */1503if(resolve_missing_loose_ref(refs, refname, sha1, type)) {1504 errno = EISDIR;1505goto out;1506}1507 ret =0;1508goto out;1509}15101511/*1512 * Anything else, just open it and try to use it as1513 * a ref1514 */1515 fd =open(path, O_RDONLY);1516if(fd <0) {1517if(errno == ENOENT)1518/* inconsistent with lstat; retry */1519goto stat_ref;1520else1521goto out;1522}1523strbuf_reset(&sb_contents);1524if(strbuf_read(&sb_contents, fd,256) <0) {1525int save_errno = errno;1526close(fd);1527 errno = save_errno;1528goto out;1529}1530close(fd);1531strbuf_rtrim(&sb_contents);1532 buf = sb_contents.buf;1533if(starts_with(buf,"ref:")) {1534 buf +=4;1535while(isspace(*buf))1536 buf++;15371538strbuf_reset(referent);1539strbuf_addstr(referent, buf);1540*type |= REF_ISSYMREF;1541 ret =0;1542goto out;1543}15441545/*1546 * Please note that FETCH_HEAD has additional1547 * data after the sha.1548 */1549if(get_sha1_hex(buf, sha1) ||1550(buf[40] !='\0'&& !isspace(buf[40]))) {1551*type |= REF_ISBROKEN;1552 errno = EINVAL;1553goto out;1554}15551556 ret =0;15571558out:1559 save_errno = errno;1560strbuf_release(&sb_path);1561strbuf_release(&sb_contents);1562 errno = save_errno;1563return ret;1564}15651566static voidunlock_ref(struct ref_lock *lock)1567{1568/* Do not free lock->lk -- atexit() still looks at them */1569if(lock->lk)1570rollback_lock_file(lock->lk);1571free(lock->ref_name);1572free(lock);1573}15741575/*1576 * Lock refname, without following symrefs, and set *lock_p to point1577 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1578 * and type similarly to read_raw_ref().1579 *1580 * The caller must verify that refname is a "safe" reference name (in1581 * the sense of refname_is_safe()) before calling this function.1582 *1583 * If the reference doesn't already exist, verify that refname doesn't1584 * have a D/F conflict with any existing references. extras and skip1585 * are passed to verify_refname_available_dir() for this check.1586 *1587 * If mustexist is not set and the reference is not found or is1588 * broken, lock the reference anyway but clear sha1.1589 *1590 * Return 0 on success. On failure, write an error message to err and1591 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1592 *1593 * Implementation note: This function is basically1594 *1595 * lock reference1596 * read_raw_ref()1597 *1598 * but it includes a lot more code to1599 * - Deal with possible races with other processes1600 * - Avoid calling verify_refname_available_dir() when it can be1601 * avoided, namely if we were successfully able to read the ref1602 * - Generate informative error messages in the case of failure1603 */1604static intlock_raw_ref(const char*refname,int mustexist,1605const struct string_list *extras,1606const struct string_list *skip,1607struct ref_lock **lock_p,1608struct strbuf *referent,1609unsigned int*type,1610struct strbuf *err)1611{1612struct files_ref_store *refs =1613get_files_ref_store(NULL,"lock_raw_ref");1614struct ref_lock *lock;1615struct strbuf ref_file = STRBUF_INIT;1616int attempts_remaining =3;1617int ret = TRANSACTION_GENERIC_ERROR;16181619assert(err);1620*type =0;16211622/* First lock the file so it can't change out from under us. */16231624*lock_p = lock =xcalloc(1,sizeof(*lock));16251626 lock->ref_name =xstrdup(refname);1627strbuf_git_path(&ref_file,"%s", refname);16281629retry:1630switch(safe_create_leading_directories(ref_file.buf)) {1631case SCLD_OK:1632break;/* success */1633case SCLD_EXISTS:1634/*1635 * Suppose refname is "refs/foo/bar". We just failed1636 * to create the containing directory, "refs/foo",1637 * because there was a non-directory in the way. This1638 * indicates a D/F conflict, probably because of1639 * another reference such as "refs/foo". There is no1640 * reason to expect this error to be transitory.1641 */1642if(verify_refname_available(refname, extras, skip, err)) {1643if(mustexist) {1644/*1645 * To the user the relevant error is1646 * that the "mustexist" reference is1647 * missing:1648 */1649strbuf_reset(err);1650strbuf_addf(err,"unable to resolve reference '%s'",1651 refname);1652}else{1653/*1654 * The error message set by1655 * verify_refname_available_dir() is OK.1656 */1657 ret = TRANSACTION_NAME_CONFLICT;1658}1659}else{1660/*1661 * The file that is in the way isn't a loose1662 * reference. Report it as a low-level1663 * failure.1664 */1665strbuf_addf(err,"unable to create lock file%s.lock; "1666"non-directory in the way",1667 ref_file.buf);1668}1669goto error_return;1670case SCLD_VANISHED:1671/* Maybe another process was tidying up. Try again. */1672if(--attempts_remaining >0)1673goto retry;1674/* fall through */1675default:1676strbuf_addf(err,"unable to create directory for%s",1677 ref_file.buf);1678goto error_return;1679}16801681if(!lock->lk)1682 lock->lk =xcalloc(1,sizeof(struct lock_file));16831684if(hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) <0) {1685if(errno == ENOENT && --attempts_remaining >0) {1686/*1687 * Maybe somebody just deleted one of the1688 * directories leading to ref_file. Try1689 * again:1690 */1691goto retry;1692}else{1693unable_to_lock_message(ref_file.buf, errno, err);1694goto error_return;1695}1696}16971698/*1699 * Now we hold the lock and can read the reference without1700 * fear that its value will change.1701 */17021703if(read_raw_ref(refname, lock->old_oid.hash, referent, type)) {1704if(errno == ENOENT) {1705if(mustexist) {1706/* Garden variety missing reference. */1707strbuf_addf(err,"unable to resolve reference '%s'",1708 refname);1709goto error_return;1710}else{1711/*1712 * Reference is missing, but that's OK. We1713 * know that there is not a conflict with1714 * another loose reference because1715 * (supposing that we are trying to lock1716 * reference "refs/foo/bar"):1717 *1718 * - We were successfully able to create1719 * the lockfile refs/foo/bar.lock, so we1720 * know there cannot be a loose reference1721 * named "refs/foo".1722 *1723 * - We got ENOENT and not EISDIR, so we1724 * know that there cannot be a loose1725 * reference named "refs/foo/bar/baz".1726 */1727}1728}else if(errno == EISDIR) {1729/*1730 * There is a directory in the way. It might have1731 * contained references that have been deleted. If1732 * we don't require that the reference already1733 * exists, try to remove the directory so that it1734 * doesn't cause trouble when we want to rename the1735 * lockfile into place later.1736 */1737if(mustexist) {1738/* Garden variety missing reference. */1739strbuf_addf(err,"unable to resolve reference '%s'",1740 refname);1741goto error_return;1742}else if(remove_dir_recursively(&ref_file,1743 REMOVE_DIR_EMPTY_ONLY)) {1744if(verify_refname_available_dir(1745 refname, extras, skip,1746get_loose_refs(refs),1747 err)) {1748/*1749 * The error message set by1750 * verify_refname_available() is OK.1751 */1752 ret = TRANSACTION_NAME_CONFLICT;1753goto error_return;1754}else{1755/*1756 * We can't delete the directory,1757 * but we also don't know of any1758 * references that it should1759 * contain.1760 */1761strbuf_addf(err,"there is a non-empty directory '%s' "1762"blocking reference '%s'",1763 ref_file.buf, refname);1764goto error_return;1765}1766}1767}else if(errno == EINVAL && (*type & REF_ISBROKEN)) {1768strbuf_addf(err,"unable to resolve reference '%s': "1769"reference broken", refname);1770goto error_return;1771}else{1772strbuf_addf(err,"unable to resolve reference '%s':%s",1773 refname,strerror(errno));1774goto error_return;1775}17761777/*1778 * If the ref did not exist and we are creating it,1779 * make sure there is no existing packed ref whose1780 * name begins with our refname, nor a packed ref1781 * whose name is a proper prefix of our refname.1782 */1783if(verify_refname_available_dir(1784 refname, extras, skip,1785get_packed_refs(refs),1786 err)) {1787goto error_return;1788}1789}17901791 ret =0;1792goto out;17931794error_return:1795unlock_ref(lock);1796*lock_p = NULL;17971798out:1799strbuf_release(&ref_file);1800return ret;1801}18021803/*1804 * Peel the entry (if possible) and return its new peel_status. If1805 * repeel is true, re-peel the entry even if there is an old peeled1806 * value that is already stored in it.1807 *1808 * It is OK to call this function with a packed reference entry that1809 * might be stale and might even refer to an object that has since1810 * been garbage-collected. In such a case, if the entry has1811 * REF_KNOWS_PEELED then leave the status unchanged and return1812 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1813 */1814static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1815{1816enum peel_status status;18171818if(entry->flag & REF_KNOWS_PEELED) {1819if(repeel) {1820 entry->flag &= ~REF_KNOWS_PEELED;1821oidclr(&entry->u.value.peeled);1822}else{1823returnis_null_oid(&entry->u.value.peeled) ?1824 PEEL_NON_TAG : PEEL_PEELED;1825}1826}1827if(entry->flag & REF_ISBROKEN)1828return PEEL_BROKEN;1829if(entry->flag & REF_ISSYMREF)1830return PEEL_IS_SYMREF;18311832 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1833if(status == PEEL_PEELED || status == PEEL_NON_TAG)1834 entry->flag |= REF_KNOWS_PEELED;1835return status;1836}18371838intpeel_ref(const char*refname,unsigned char*sha1)1839{1840struct files_ref_store *refs =get_files_ref_store(NULL,"peel_ref");1841int flag;1842unsigned char base[20];18431844if(current_ref_iter && current_ref_iter->refname == refname) {1845struct object_id peeled;18461847if(ref_iterator_peel(current_ref_iter, &peeled))1848return-1;1849hashcpy(sha1, peeled.hash);1850return0;1851}18521853if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1854return-1;18551856/*1857 * If the reference is packed, read its ref_entry from the1858 * cache in the hope that we already know its peeled value.1859 * We only try this optimization on packed references because1860 * (a) forcing the filling of the loose reference cache could1861 * be expensive and (b) loose references anyway usually do not1862 * have REF_KNOWS_PEELED.1863 */1864if(flag & REF_ISPACKED) {1865struct ref_entry *r =get_packed_ref(refs, refname);1866if(r) {1867if(peel_entry(r,0))1868return-1;1869hashcpy(sha1, r->u.value.peeled.hash);1870return0;1871}1872}18731874returnpeel_object(base, sha1);1875}18761877struct files_ref_iterator {1878struct ref_iterator base;18791880struct packed_ref_cache *packed_ref_cache;1881struct ref_iterator *iter0;1882unsigned int flags;1883};18841885static intfiles_ref_iterator_advance(struct ref_iterator *ref_iterator)1886{1887struct files_ref_iterator *iter =1888(struct files_ref_iterator *)ref_iterator;1889int ok;18901891while((ok =ref_iterator_advance(iter->iter0)) == ITER_OK) {1892if(!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1893!ref_resolves_to_object(iter->iter0->refname,1894 iter->iter0->oid,1895 iter->iter0->flags))1896continue;18971898 iter->base.refname = iter->iter0->refname;1899 iter->base.oid = iter->iter0->oid;1900 iter->base.flags = iter->iter0->flags;1901return ITER_OK;1902}19031904 iter->iter0 = NULL;1905if(ref_iterator_abort(ref_iterator) != ITER_DONE)1906 ok = ITER_ERROR;19071908return ok;1909}19101911static intfiles_ref_iterator_peel(struct ref_iterator *ref_iterator,1912struct object_id *peeled)1913{1914struct files_ref_iterator *iter =1915(struct files_ref_iterator *)ref_iterator;19161917returnref_iterator_peel(iter->iter0, peeled);1918}19191920static intfiles_ref_iterator_abort(struct ref_iterator *ref_iterator)1921{1922struct files_ref_iterator *iter =1923(struct files_ref_iterator *)ref_iterator;1924int ok = ITER_DONE;19251926if(iter->iter0)1927 ok =ref_iterator_abort(iter->iter0);19281929release_packed_ref_cache(iter->packed_ref_cache);1930base_ref_iterator_free(ref_iterator);1931return ok;1932}19331934static struct ref_iterator_vtable files_ref_iterator_vtable = {1935 files_ref_iterator_advance,1936 files_ref_iterator_peel,1937 files_ref_iterator_abort1938};19391940struct ref_iterator *files_ref_iterator_begin(1941const char*submodule,1942const char*prefix,unsigned int flags)1943{1944struct files_ref_store *refs =1945get_files_ref_store(submodule,"ref_iterator_begin");1946struct ref_dir *loose_dir, *packed_dir;1947struct ref_iterator *loose_iter, *packed_iter;1948struct files_ref_iterator *iter;1949struct ref_iterator *ref_iterator;19501951if(!refs)1952returnempty_ref_iterator_begin();19531954if(ref_paranoia <0)1955 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1956if(ref_paranoia)1957 flags |= DO_FOR_EACH_INCLUDE_BROKEN;19581959 iter =xcalloc(1,sizeof(*iter));1960 ref_iterator = &iter->base;1961base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);19621963/*1964 * We must make sure that all loose refs are read before1965 * accessing the packed-refs file; this avoids a race1966 * condition if loose refs are migrated to the packed-refs1967 * file by a simultaneous process, but our in-memory view is1968 * from before the migration. We ensure this as follows:1969 * First, we call prime_ref_dir(), which pre-reads the loose1970 * references for the subtree into the cache. (If they've1971 * already been read, that's OK; we only need to guarantee1972 * that they're read before the packed refs, not *how much*1973 * before.) After that, we call get_packed_ref_cache(), which1974 * internally checks whether the packed-ref cache is up to1975 * date with what is on disk, and re-reads it if not.1976 */19771978 loose_dir =get_loose_refs(refs);19791980if(prefix && *prefix)1981 loose_dir =find_containing_dir(loose_dir, prefix,0);19821983if(loose_dir) {1984prime_ref_dir(loose_dir);1985 loose_iter =cache_ref_iterator_begin(loose_dir);1986}else{1987/* There's nothing to iterate over. */1988 loose_iter =empty_ref_iterator_begin();1989}19901991 iter->packed_ref_cache =get_packed_ref_cache(refs);1992acquire_packed_ref_cache(iter->packed_ref_cache);1993 packed_dir =get_packed_ref_dir(iter->packed_ref_cache);19941995if(prefix && *prefix)1996 packed_dir =find_containing_dir(packed_dir, prefix,0);19971998if(packed_dir) {1999 packed_iter =cache_ref_iterator_begin(packed_dir);2000}else{2001/* There's nothing to iterate over. */2002 packed_iter =empty_ref_iterator_begin();2003}20042005 iter->iter0 =overlay_ref_iterator_begin(loose_iter, packed_iter);2006 iter->flags = flags;20072008return ref_iterator;2009}20102011/*2012 * Verify that the reference locked by lock has the value old_sha1.2013 * Fail if the reference doesn't exist and mustexist is set. Return 02014 * on success. On error, write an error message to err, set errno, and2015 * return a negative value.2016 */2017static intverify_lock(struct ref_lock *lock,2018const unsigned char*old_sha1,int mustexist,2019struct strbuf *err)2020{2021assert(err);20222023if(read_ref_full(lock->ref_name,2024 mustexist ? RESOLVE_REF_READING :0,2025 lock->old_oid.hash, NULL)) {2026if(old_sha1) {2027int save_errno = errno;2028strbuf_addf(err,"can't verify ref '%s'", lock->ref_name);2029 errno = save_errno;2030return-1;2031}else{2032hashclr(lock->old_oid.hash);2033return0;2034}2035}2036if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {2037strbuf_addf(err,"ref '%s' is at%sbut expected%s",2038 lock->ref_name,2039sha1_to_hex(lock->old_oid.hash),2040sha1_to_hex(old_sha1));2041 errno = EBUSY;2042return-1;2043}2044return0;2045}20462047static intremove_empty_directories(struct strbuf *path)2048{2049/*2050 * we want to create a file but there is a directory there;2051 * if that is an empty directory (or a directory that contains2052 * only empty directories), remove them.2053 */2054returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);2055}20562057/*2058 * Locks a ref returning the lock on success and NULL on failure.2059 * On failure errno is set to something meaningful.2060 */2061static struct ref_lock *lock_ref_sha1_basic(const char*refname,2062const unsigned char*old_sha1,2063const struct string_list *extras,2064const struct string_list *skip,2065unsigned int flags,int*type,2066struct strbuf *err)2067{2068struct files_ref_store *refs =2069get_files_ref_store(NULL,"lock_ref_sha1_basic");2070struct strbuf ref_file = STRBUF_INIT;2071struct ref_lock *lock;2072int last_errno =0;2073int lflags = LOCK_NO_DEREF;2074int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2075int resolve_flags = RESOLVE_REF_NO_RECURSE;2076int attempts_remaining =3;2077int resolved;20782079assert(err);20802081 lock =xcalloc(1,sizeof(struct ref_lock));20822083if(mustexist)2084 resolve_flags |= RESOLVE_REF_READING;2085if(flags & REF_DELETING)2086 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20872088strbuf_git_path(&ref_file,"%s", refname);2089 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2090 lock->old_oid.hash, type);2091if(!resolved && errno == EISDIR) {2092/*2093 * we are trying to lock foo but we used to2094 * have foo/bar which now does not exist;2095 * it is normal for the empty directory 'foo'2096 * to remain.2097 */2098if(remove_empty_directories(&ref_file)) {2099 last_errno = errno;2100if(!verify_refname_available_dir(2101 refname, extras, skip,2102get_loose_refs(refs), err))2103strbuf_addf(err,"there are still refs under '%s'",2104 refname);2105goto error_return;2106}2107 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2108 lock->old_oid.hash, type);2109}2110if(!resolved) {2111 last_errno = errno;2112if(last_errno != ENOTDIR ||2113!verify_refname_available_dir(2114 refname, extras, skip,2115get_loose_refs(refs), err))2116strbuf_addf(err,"unable to resolve reference '%s':%s",2117 refname,strerror(last_errno));21182119goto error_return;2120}21212122/*2123 * If the ref did not exist and we are creating it, make sure2124 * there is no existing packed ref whose name begins with our2125 * refname, nor a packed ref whose name is a proper prefix of2126 * our refname.2127 */2128if(is_null_oid(&lock->old_oid) &&2129verify_refname_available_dir(refname, extras, skip,2130get_packed_refs(refs),2131 err)) {2132 last_errno = ENOTDIR;2133goto error_return;2134}21352136 lock->lk =xcalloc(1,sizeof(struct lock_file));21372138 lock->ref_name =xstrdup(refname);21392140 retry:2141switch(safe_create_leading_directories_const(ref_file.buf)) {2142case SCLD_OK:2143break;/* success */2144case SCLD_VANISHED:2145if(--attempts_remaining >0)2146goto retry;2147/* fall through */2148default:2149 last_errno = errno;2150strbuf_addf(err,"unable to create directory for '%s'",2151 ref_file.buf);2152goto error_return;2153}21542155if(hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) <0) {2156 last_errno = errno;2157if(errno == ENOENT && --attempts_remaining >0)2158/*2159 * Maybe somebody just deleted one of the2160 * directories leading to ref_file. Try2161 * again:2162 */2163goto retry;2164else{2165unable_to_lock_message(ref_file.buf, errno, err);2166goto error_return;2167}2168}2169if(verify_lock(lock, old_sha1, mustexist, err)) {2170 last_errno = errno;2171goto error_return;2172}2173goto out;21742175 error_return:2176unlock_ref(lock);2177 lock = NULL;21782179 out:2180strbuf_release(&ref_file);2181 errno = last_errno;2182return lock;2183}21842185/*2186 * Write an entry to the packed-refs file for the specified refname.2187 * If peeled is non-NULL, write it as the entry's peeled value.2188 */2189static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2190unsigned char*peeled)2191{2192fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2193if(peeled)2194fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2195}21962197/*2198 * An each_ref_entry_fn that writes the entry to a packed-refs file.2199 */2200static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2201{2202enum peel_status peel_status =peel_entry(entry,0);22032204if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2205error("internal error:%sis not a valid packed reference!",2206 entry->name);2207write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2208 peel_status == PEEL_PEELED ?2209 entry->u.value.peeled.hash : NULL);2210return0;2211}22122213/*2214 * Lock the packed-refs file for writing. Flags is passed to2215 * hold_lock_file_for_update(). Return 0 on success. On errors, set2216 * errno appropriately and return a nonzero value.2217 */2218static intlock_packed_refs(int flags)2219{2220struct files_ref_store *refs =2221get_files_ref_store(NULL,"lock_packed_refs");2222static int timeout_configured =0;2223static int timeout_value =1000;2224struct packed_ref_cache *packed_ref_cache;22252226if(!timeout_configured) {2227git_config_get_int("core.packedrefstimeout", &timeout_value);2228 timeout_configured =1;2229}22302231if(hold_lock_file_for_update_timeout(2232&packlock,git_path("packed-refs"),2233 flags, timeout_value) <0)2234return-1;2235/*2236 * Get the current packed-refs while holding the lock. If the2237 * packed-refs file has been modified since we last read it,2238 * this will automatically invalidate the cache and re-read2239 * the packed-refs file.2240 */2241 packed_ref_cache =get_packed_ref_cache(refs);2242 packed_ref_cache->lock = &packlock;2243/* Increment the reference count to prevent it from being freed: */2244acquire_packed_ref_cache(packed_ref_cache);2245return0;2246}22472248/*2249 * Write the current version of the packed refs cache from memory to2250 * disk. The packed-refs file must already be locked for writing (see2251 * lock_packed_refs()). Return zero on success. On errors, set errno2252 * and return a nonzero value2253 */2254static intcommit_packed_refs(void)2255{2256struct files_ref_store *refs =2257get_files_ref_store(NULL,"commit_packed_refs");2258struct packed_ref_cache *packed_ref_cache =2259get_packed_ref_cache(refs);2260int error =0;2261int save_errno =0;2262FILE*out;22632264if(!packed_ref_cache->lock)2265die("internal error: packed-refs not locked");22662267 out =fdopen_lock_file(packed_ref_cache->lock,"w");2268if(!out)2269die_errno("unable to fdopen packed-refs descriptor");22702271fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2272do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),22730, write_packed_entry_fn, out);22742275if(commit_lock_file(packed_ref_cache->lock)) {2276 save_errno = errno;2277 error = -1;2278}2279 packed_ref_cache->lock = NULL;2280release_packed_ref_cache(packed_ref_cache);2281 errno = save_errno;2282return error;2283}22842285/*2286 * Rollback the lockfile for the packed-refs file, and discard the2287 * in-memory packed reference cache. (The packed-refs file will be2288 * read anew if it is needed again after this function is called.)2289 */2290static voidrollback_packed_refs(void)2291{2292struct files_ref_store *refs =2293get_files_ref_store(NULL,"rollback_packed_refs");2294struct packed_ref_cache *packed_ref_cache =2295get_packed_ref_cache(refs);22962297if(!packed_ref_cache->lock)2298die("internal error: packed-refs not locked");2299rollback_lock_file(packed_ref_cache->lock);2300 packed_ref_cache->lock = NULL;2301release_packed_ref_cache(packed_ref_cache);2302clear_packed_ref_cache(refs);2303}23042305struct ref_to_prune {2306struct ref_to_prune *next;2307unsigned char sha1[20];2308char name[FLEX_ARRAY];2309};23102311struct pack_refs_cb_data {2312unsigned int flags;2313struct ref_dir *packed_refs;2314struct ref_to_prune *ref_to_prune;2315};23162317/*2318 * An each_ref_entry_fn that is run over loose references only. If2319 * the loose reference can be packed, add an entry in the packed ref2320 * cache. If the reference should be pruned, also add it to2321 * ref_to_prune in the pack_refs_cb_data.2322 */2323static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2324{2325struct pack_refs_cb_data *cb = cb_data;2326enum peel_status peel_status;2327struct ref_entry *packed_entry;2328int is_tag_ref =starts_with(entry->name,"refs/tags/");23292330/* Do not pack per-worktree refs: */2331if(ref_type(entry->name) != REF_TYPE_NORMAL)2332return0;23332334/* ALWAYS pack tags */2335if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2336return0;23372338/* Do not pack symbolic or broken refs: */2339if((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2340return0;23412342/* Add a packed ref cache entry equivalent to the loose entry. */2343 peel_status =peel_entry(entry,1);2344if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2345die("internal error peeling reference%s(%s)",2346 entry->name,oid_to_hex(&entry->u.value.oid));2347 packed_entry =find_ref(cb->packed_refs, entry->name);2348if(packed_entry) {2349/* Overwrite existing packed entry with info from loose entry */2350 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2351oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2352}else{2353 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2354 REF_ISPACKED | REF_KNOWS_PEELED,0);2355add_ref(cb->packed_refs, packed_entry);2356}2357oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);23582359/* Schedule the loose reference for pruning if requested. */2360if((cb->flags & PACK_REFS_PRUNE)) {2361struct ref_to_prune *n;2362FLEX_ALLOC_STR(n, name, entry->name);2363hashcpy(n->sha1, entry->u.value.oid.hash);2364 n->next = cb->ref_to_prune;2365 cb->ref_to_prune = n;2366}2367return0;2368}23692370/*2371 * Remove empty parents, but spare refs/ and immediate subdirs.2372 * Note: munges *name.2373 */2374static voidtry_remove_empty_parents(char*name)2375{2376char*p, *q;2377int i;2378 p = name;2379for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2380while(*p && *p !='/')2381 p++;2382/* tolerate duplicate slashes; see check_refname_format() */2383while(*p =='/')2384 p++;2385}2386for(q = p; *q; q++)2387;2388while(1) {2389while(q > p && *q !='/')2390 q--;2391while(q > p && *(q-1) =='/')2392 q--;2393if(q == p)2394break;2395*q ='\0';2396if(rmdir(git_path("%s", name)))2397break;2398}2399}24002401/* make sure nobody touched the ref, and unlink */2402static voidprune_ref(struct ref_to_prune *r)2403{2404struct ref_transaction *transaction;2405struct strbuf err = STRBUF_INIT;24062407if(check_refname_format(r->name,0))2408return;24092410 transaction =ref_transaction_begin(&err);2411if(!transaction ||2412ref_transaction_delete(transaction, r->name, r->sha1,2413 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2414ref_transaction_commit(transaction, &err)) {2415ref_transaction_free(transaction);2416error("%s", err.buf);2417strbuf_release(&err);2418return;2419}2420ref_transaction_free(transaction);2421strbuf_release(&err);2422try_remove_empty_parents(r->name);2423}24242425static voidprune_refs(struct ref_to_prune *r)2426{2427while(r) {2428prune_ref(r);2429 r = r->next;2430}2431}24322433intpack_refs(unsigned int flags)2434{2435struct files_ref_store *refs =2436get_files_ref_store(NULL,"pack_refs");2437struct pack_refs_cb_data cbdata;24382439memset(&cbdata,0,sizeof(cbdata));2440 cbdata.flags = flags;24412442lock_packed_refs(LOCK_DIE_ON_ERROR);2443 cbdata.packed_refs =get_packed_refs(refs);24442445do_for_each_entry_in_dir(get_loose_refs(refs),0,2446 pack_if_possible_fn, &cbdata);24472448if(commit_packed_refs())2449die_errno("unable to overwrite old ref-pack file");24502451prune_refs(cbdata.ref_to_prune);2452return0;2453}24542455/*2456 * Rewrite the packed-refs file, omitting any refs listed in2457 * 'refnames'. On error, leave packed-refs unchanged, write an error2458 * message to 'err', and return a nonzero value.2459 *2460 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2461 */2462static intrepack_without_refs(struct string_list *refnames,struct strbuf *err)2463{2464struct files_ref_store *refs =2465get_files_ref_store(NULL,"repack_without_refs");2466struct ref_dir *packed;2467struct string_list_item *refname;2468int ret, needs_repacking =0, removed =0;24692470assert(err);24712472/* Look for a packed ref */2473for_each_string_list_item(refname, refnames) {2474if(get_packed_ref(refs, refname->string)) {2475 needs_repacking =1;2476break;2477}2478}24792480/* Avoid locking if we have nothing to do */2481if(!needs_repacking)2482return0;/* no refname exists in packed refs */24832484if(lock_packed_refs(0)) {2485unable_to_lock_message(git_path("packed-refs"), errno, err);2486return-1;2487}2488 packed =get_packed_refs(refs);24892490/* Remove refnames from the cache */2491for_each_string_list_item(refname, refnames)2492if(remove_entry(packed, refname->string) != -1)2493 removed =1;2494if(!removed) {2495/*2496 * All packed entries disappeared while we were2497 * acquiring the lock.2498 */2499rollback_packed_refs();2500return0;2501}25022503/* Write what remains */2504 ret =commit_packed_refs();2505if(ret)2506strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2507strerror(errno));2508return ret;2509}25102511static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2512{2513assert(err);25142515if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2516/*2517 * loose. The loose file name is the same as the2518 * lockfile name, minus ".lock":2519 */2520char*loose_filename =get_locked_file_path(lock->lk);2521int res =unlink_or_msg(loose_filename, err);2522free(loose_filename);2523if(res)2524return1;2525}2526return0;2527}25282529intdelete_refs(struct string_list *refnames,unsigned int flags)2530{2531struct strbuf err = STRBUF_INIT;2532int i, result =0;25332534if(!refnames->nr)2535return0;25362537 result =repack_without_refs(refnames, &err);2538if(result) {2539/*2540 * If we failed to rewrite the packed-refs file, then2541 * it is unsafe to try to remove loose refs, because2542 * doing so might expose an obsolete packed value for2543 * a reference that might even point at an object that2544 * has been garbage collected.2545 */2546if(refnames->nr ==1)2547error(_("could not delete reference%s:%s"),2548 refnames->items[0].string, err.buf);2549else2550error(_("could not delete references:%s"), err.buf);25512552goto out;2553}25542555for(i =0; i < refnames->nr; i++) {2556const char*refname = refnames->items[i].string;25572558if(delete_ref(refname, NULL, flags))2559 result |=error(_("could not remove reference%s"), refname);2560}25612562out:2563strbuf_release(&err);2564return result;2565}25662567/*2568 * People using contrib's git-new-workdir have .git/logs/refs ->2569 * /some/other/path/.git/logs/refs, and that may live on another device.2570 *2571 * IOW, to avoid cross device rename errors, the temporary renamed log must2572 * live into logs/refs.2573 */2574#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"25752576static intrename_tmp_log(const char*newrefname)2577{2578int attempts_remaining =4;2579struct strbuf path = STRBUF_INIT;2580int ret = -1;25812582 retry:2583strbuf_reset(&path);2584strbuf_git_path(&path,"logs/%s", newrefname);2585switch(safe_create_leading_directories_const(path.buf)) {2586case SCLD_OK:2587break;/* success */2588case SCLD_VANISHED:2589if(--attempts_remaining >0)2590goto retry;2591/* fall through */2592default:2593error("unable to create directory for%s", newrefname);2594goto out;2595}25962597if(rename(git_path(TMP_RENAMED_LOG), path.buf)) {2598if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2599/*2600 * rename(a, b) when b is an existing2601 * directory ought to result in ISDIR, but2602 * Solaris 5.8 gives ENOTDIR. Sheesh.2603 */2604if(remove_empty_directories(&path)) {2605error("Directory not empty: logs/%s", newrefname);2606goto out;2607}2608goto retry;2609}else if(errno == ENOENT && --attempts_remaining >0) {2610/*2611 * Maybe another process just deleted one of2612 * the directories in the path to newrefname.2613 * Try again from the beginning.2614 */2615goto retry;2616}else{2617error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2618 newrefname,strerror(errno));2619goto out;2620}2621}2622 ret =0;2623out:2624strbuf_release(&path);2625return ret;2626}26272628intverify_refname_available(const char*newname,2629const struct string_list *extras,2630const struct string_list *skip,2631struct strbuf *err)2632{2633struct files_ref_store *refs =2634get_files_ref_store(NULL,"verify_refname_available");2635struct ref_dir *packed_refs =get_packed_refs(refs);2636struct ref_dir *loose_refs =get_loose_refs(refs);26372638if(verify_refname_available_dir(newname, extras, skip,2639 packed_refs, err) ||2640verify_refname_available_dir(newname, extras, skip,2641 loose_refs, err))2642return-1;26432644return0;2645}26462647static intwrite_ref_to_lockfile(struct ref_lock *lock,2648const unsigned char*sha1,struct strbuf *err);2649static intcommit_ref_update(struct ref_lock *lock,2650const unsigned char*sha1,const char*logmsg,2651struct strbuf *err);26522653intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2654{2655unsigned char sha1[20], orig_sha1[20];2656int flag =0, logmoved =0;2657struct ref_lock *lock;2658struct stat loginfo;2659int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2660struct strbuf err = STRBUF_INIT;26612662if(log &&S_ISLNK(loginfo.st_mode))2663returnerror("reflog for%sis a symlink", oldrefname);26642665if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2666 orig_sha1, &flag))2667returnerror("refname%snot found", oldrefname);26682669if(flag & REF_ISSYMREF)2670returnerror("refname%sis a symbolic ref, renaming it is not supported",2671 oldrefname);2672if(!rename_ref_available(oldrefname, newrefname))2673return1;26742675if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2676returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2677 oldrefname,strerror(errno));26782679if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2680error("unable to delete old%s", oldrefname);2681goto rollback;2682}26832684/*2685 * Since we are doing a shallow lookup, sha1 is not the2686 * correct value to pass to delete_ref as old_sha1. But that2687 * doesn't matter, because an old_sha1 check wouldn't add to2688 * the safety anyway; we want to delete the reference whatever2689 * its current value.2690 */2691if(!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2692 sha1, NULL) &&2693delete_ref(newrefname, NULL, REF_NODEREF)) {2694if(errno==EISDIR) {2695struct strbuf path = STRBUF_INIT;2696int result;26972698strbuf_git_path(&path,"%s", newrefname);2699 result =remove_empty_directories(&path);2700strbuf_release(&path);27012702if(result) {2703error("Directory not empty:%s", newrefname);2704goto rollback;2705}2706}else{2707error("unable to delete existing%s", newrefname);2708goto rollback;2709}2710}27112712if(log &&rename_tmp_log(newrefname))2713goto rollback;27142715 logmoved = log;27162717 lock =lock_ref_sha1_basic(newrefname, NULL, NULL, NULL, REF_NODEREF,2718 NULL, &err);2719if(!lock) {2720error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2721strbuf_release(&err);2722goto rollback;2723}2724hashcpy(lock->old_oid.hash, orig_sha1);27252726if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2727commit_ref_update(lock, orig_sha1, logmsg, &err)) {2728error("unable to write current sha1 into%s:%s", newrefname, err.buf);2729strbuf_release(&err);2730goto rollback;2731}27322733return0;27342735 rollback:2736 lock =lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL, REF_NODEREF,2737 NULL, &err);2738if(!lock) {2739error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2740strbuf_release(&err);2741goto rollbacklog;2742}27432744 flag = log_all_ref_updates;2745 log_all_ref_updates =0;2746if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2747commit_ref_update(lock, orig_sha1, NULL, &err)) {2748error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2749strbuf_release(&err);2750}2751 log_all_ref_updates = flag;27522753 rollbacklog:2754if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2755error("unable to restore logfile%sfrom%s:%s",2756 oldrefname, newrefname,strerror(errno));2757if(!logmoved && log &&2758rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2759error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2760 oldrefname,strerror(errno));27612762return1;2763}27642765static intclose_ref(struct ref_lock *lock)2766{2767if(close_lock_file(lock->lk))2768return-1;2769return0;2770}27712772static intcommit_ref(struct ref_lock *lock)2773{2774char*path =get_locked_file_path(lock->lk);2775struct stat st;27762777if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2778/*2779 * There is a directory at the path we want to rename2780 * the lockfile to. Hopefully it is empty; try to2781 * delete it.2782 */2783size_t len =strlen(path);2784struct strbuf sb_path = STRBUF_INIT;27852786strbuf_attach(&sb_path, path, len, len);27872788/*2789 * If this fails, commit_lock_file() will also fail2790 * and will report the problem.2791 */2792remove_empty_directories(&sb_path);2793strbuf_release(&sb_path);2794}else{2795free(path);2796}27972798if(commit_lock_file(lock->lk))2799return-1;2800return0;2801}28022803/*2804 * Create a reflog for a ref. If force_create = 0, the reflog will2805 * only be created for certain refs (those for which2806 * should_autocreate_reflog returns non-zero. Otherwise, create it2807 * regardless of the ref name. Fill in *err and return -1 on failure.2808 */2809static intlog_ref_setup(const char*refname,struct strbuf *logfile,struct strbuf *err,int force_create)2810{2811int logfd, oflags = O_APPEND | O_WRONLY;28122813strbuf_git_path(logfile,"logs/%s", refname);2814if(force_create ||should_autocreate_reflog(refname)) {2815if(safe_create_leading_directories(logfile->buf) <0) {2816strbuf_addf(err,"unable to create directory for '%s': "2817"%s", logfile->buf,strerror(errno));2818return-1;2819}2820 oflags |= O_CREAT;2821}28222823 logfd =open(logfile->buf, oflags,0666);2824if(logfd <0) {2825if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2826return0;28272828if(errno == EISDIR) {2829if(remove_empty_directories(logfile)) {2830strbuf_addf(err,"there are still logs under "2831"'%s'", logfile->buf);2832return-1;2833}2834 logfd =open(logfile->buf, oflags,0666);2835}28362837if(logfd <0) {2838strbuf_addf(err,"unable to append to '%s':%s",2839 logfile->buf,strerror(errno));2840return-1;2841}2842}28432844adjust_shared_perm(logfile->buf);2845close(logfd);2846return0;2847}284828492850intsafe_create_reflog(const char*refname,int force_create,struct strbuf *err)2851{2852int ret;2853struct strbuf sb = STRBUF_INIT;28542855 ret =log_ref_setup(refname, &sb, err, force_create);2856strbuf_release(&sb);2857return ret;2858}28592860static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2861const unsigned char*new_sha1,2862const char*committer,const char*msg)2863{2864int msglen, written;2865unsigned maxlen, len;2866char*logrec;28672868 msglen = msg ?strlen(msg) :0;2869 maxlen =strlen(committer) + msglen +100;2870 logrec =xmalloc(maxlen);2871 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2872sha1_to_hex(old_sha1),2873sha1_to_hex(new_sha1),2874 committer);2875if(msglen)2876 len +=copy_reflog_msg(logrec + len -1, msg) -1;28772878 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2879free(logrec);2880if(written != len)2881return-1;28822883return0;2884}28852886static intlog_ref_write_1(const char*refname,const unsigned char*old_sha1,2887const unsigned char*new_sha1,const char*msg,2888struct strbuf *logfile,int flags,2889struct strbuf *err)2890{2891int logfd, result, oflags = O_APPEND | O_WRONLY;28922893if(log_all_ref_updates <0)2894 log_all_ref_updates = !is_bare_repository();28952896 result =log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);28972898if(result)2899return result;29002901 logfd =open(logfile->buf, oflags);2902if(logfd <0)2903return0;2904 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2905git_committer_info(0), msg);2906if(result) {2907strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2908strerror(errno));2909close(logfd);2910return-1;2911}2912if(close(logfd)) {2913strbuf_addf(err,"unable to append to '%s':%s", logfile->buf,2914strerror(errno));2915return-1;2916}2917return0;2918}29192920static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2921const unsigned char*new_sha1,const char*msg,2922int flags,struct strbuf *err)2923{2924returnfiles_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2925 err);2926}29272928intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1,2929const unsigned char*new_sha1,const char*msg,2930int flags,struct strbuf *err)2931{2932struct strbuf sb = STRBUF_INIT;2933int ret =log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2934 err);2935strbuf_release(&sb);2936return ret;2937}29382939/*2940 * Write sha1 into the open lockfile, then close the lockfile. On2941 * errors, rollback the lockfile, fill in *err and2942 * return -1.2943 */2944static intwrite_ref_to_lockfile(struct ref_lock *lock,2945const unsigned char*sha1,struct strbuf *err)2946{2947static char term ='\n';2948struct object *o;2949int fd;29502951 o =parse_object(sha1);2952if(!o) {2953strbuf_addf(err,2954"trying to write ref '%s' with nonexistent object%s",2955 lock->ref_name,sha1_to_hex(sha1));2956unlock_ref(lock);2957return-1;2958}2959if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2960strbuf_addf(err,2961"trying to write non-commit object%sto branch '%s'",2962sha1_to_hex(sha1), lock->ref_name);2963unlock_ref(lock);2964return-1;2965}2966 fd =get_lock_file_fd(lock->lk);2967if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2968write_in_full(fd, &term,1) !=1||2969close_ref(lock) <0) {2970strbuf_addf(err,2971"couldn't write '%s'",get_lock_file_path(lock->lk));2972unlock_ref(lock);2973return-1;2974}2975return0;2976}29772978/*2979 * Commit a change to a loose reference that has already been written2980 * to the loose reference lockfile. Also update the reflogs if2981 * necessary, using the specified lockmsg (which can be NULL).2982 */2983static intcommit_ref_update(struct ref_lock *lock,2984const unsigned char*sha1,const char*logmsg,2985struct strbuf *err)2986{2987struct files_ref_store *refs =2988get_files_ref_store(NULL,"commit_ref_update");29892990clear_loose_ref_cache(refs);2991if(log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg,0, err)) {2992char*old_msg =strbuf_detach(err, NULL);2993strbuf_addf(err,"cannot update the ref '%s':%s",2994 lock->ref_name, old_msg);2995free(old_msg);2996unlock_ref(lock);2997return-1;2998}29993000if(strcmp(lock->ref_name,"HEAD") !=0) {3001/*3002 * Special hack: If a branch is updated directly and HEAD3003 * points to it (may happen on the remote side of a push3004 * for example) then logically the HEAD reflog should be3005 * updated too.3006 * A generic solution implies reverse symref information,3007 * but finding all symrefs pointing to the given branch3008 * would be rather costly for this rare event (the direct3009 * update of a branch) to be worth it. So let's cheat and3010 * check with HEAD only which should cover 99% of all usage3011 * scenarios (even 100% of the default ones).3012 */3013unsigned char head_sha1[20];3014int head_flag;3015const char*head_ref;30163017 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3018 head_sha1, &head_flag);3019if(head_ref && (head_flag & REF_ISSYMREF) &&3020!strcmp(head_ref, lock->ref_name)) {3021struct strbuf log_err = STRBUF_INIT;3022if(log_ref_write("HEAD", lock->old_oid.hash, sha1,3023 logmsg,0, &log_err)) {3024error("%s", log_err.buf);3025strbuf_release(&log_err);3026}3027}3028}30293030if(commit_ref(lock)) {3031strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3032unlock_ref(lock);3033return-1;3034}30353036unlock_ref(lock);3037return0;3038}30393040static intcreate_ref_symlink(struct ref_lock *lock,const char*target)3041{3042int ret = -1;3043#ifndef NO_SYMLINK_HEAD3044char*ref_path =get_locked_file_path(lock->lk);3045unlink(ref_path);3046 ret =symlink(target, ref_path);3047free(ref_path);30483049if(ret)3050fprintf(stderr,"no symlink - falling back to symbolic ref\n");3051#endif3052return ret;3053}30543055static voidupdate_symref_reflog(struct ref_lock *lock,const char*refname,3056const char*target,const char*logmsg)3057{3058struct strbuf err = STRBUF_INIT;3059unsigned char new_sha1[20];3060if(logmsg && !read_ref(target, new_sha1) &&3061log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg,0, &err)) {3062error("%s", err.buf);3063strbuf_release(&err);3064}3065}30663067static intcreate_symref_locked(struct ref_lock *lock,const char*refname,3068const char*target,const char*logmsg)3069{3070if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {3071update_symref_reflog(lock, refname, target, logmsg);3072return0;3073}30743075if(!fdopen_lock_file(lock->lk,"w"))3076returnerror("unable to fdopen%s:%s",3077 lock->lk->tempfile.filename.buf,strerror(errno));30783079update_symref_reflog(lock, refname, target, logmsg);30803081/* no error check; commit_ref will check ferror */3082fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);3083if(commit_ref(lock) <0)3084returnerror("unable to write symref for%s:%s", refname,3085strerror(errno));3086return0;3087}30883089intcreate_symref(const char*refname,const char*target,const char*logmsg)3090{3091struct strbuf err = STRBUF_INIT;3092struct ref_lock *lock;3093int ret;30943095 lock =lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,3096&err);3097if(!lock) {3098error("%s", err.buf);3099strbuf_release(&err);3100return-1;3101}31023103 ret =create_symref_locked(lock, refname, target, logmsg);3104unlock_ref(lock);3105return ret;3106}31073108intset_worktree_head_symref(const char*gitdir,const char*target)3109{3110static struct lock_file head_lock;3111struct ref_lock *lock;3112struct strbuf head_path = STRBUF_INIT;3113const char*head_rel;3114int ret;31153116strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));3117if(hold_lock_file_for_update(&head_lock, head_path.buf,3118 LOCK_NO_DEREF) <0) {3119struct strbuf err = STRBUF_INIT;3120unable_to_lock_message(head_path.buf, errno, &err);3121error("%s", err.buf);3122strbuf_release(&err);3123strbuf_release(&head_path);3124return-1;3125}31263127/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3128 linked trees */3129 head_rel =remove_leading_path(head_path.buf,3130absolute_path(get_git_common_dir()));3131/* to make use of create_symref_locked(), initialize ref_lock */3132 lock =xcalloc(1,sizeof(struct ref_lock));3133 lock->lk = &head_lock;3134 lock->ref_name =xstrdup(head_rel);31353136 ret =create_symref_locked(lock, head_rel, target, NULL);31373138unlock_ref(lock);/* will free lock */3139strbuf_release(&head_path);3140return ret;3141}31423143intreflog_exists(const char*refname)3144{3145struct stat st;31463147return!lstat(git_path("logs/%s", refname), &st) &&3148S_ISREG(st.st_mode);3149}31503151intdelete_reflog(const char*refname)3152{3153returnremove_path(git_path("logs/%s", refname));3154}31553156static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3157{3158unsigned char osha1[20], nsha1[20];3159char*email_end, *message;3160unsigned long timestamp;3161int tz;31623163/* old SP new SP name <email> SP time TAB msg LF */3164if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3165get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3166get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3167!(email_end =strchr(sb->buf +82,'>')) ||3168 email_end[1] !=' '||3169!(timestamp =strtoul(email_end +2, &message,10)) ||3170!message || message[0] !=' '||3171(message[1] !='+'&& message[1] !='-') ||3172!isdigit(message[2]) || !isdigit(message[3]) ||3173!isdigit(message[4]) || !isdigit(message[5]))3174return0;/* corrupt? */3175 email_end[1] ='\0';3176 tz =strtol(message +1, NULL,10);3177if(message[6] !='\t')3178 message +=6;3179else3180 message +=7;3181returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3182}31833184static char*find_beginning_of_line(char*bob,char*scan)3185{3186while(bob < scan && *(--scan) !='\n')3187;/* keep scanning backwards */3188/*3189 * Return either beginning of the buffer, or LF at the end of3190 * the previous line.3191 */3192return scan;3193}31943195intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3196{3197struct strbuf sb = STRBUF_INIT;3198FILE*logfp;3199long pos;3200int ret =0, at_tail =1;32013202 logfp =fopen(git_path("logs/%s", refname),"r");3203if(!logfp)3204return-1;32053206/* Jump to the end */3207if(fseek(logfp,0, SEEK_END) <0)3208returnerror("cannot seek back reflog for%s:%s",3209 refname,strerror(errno));3210 pos =ftell(logfp);3211while(!ret &&0< pos) {3212int cnt;3213size_t nread;3214char buf[BUFSIZ];3215char*endp, *scanp;32163217/* Fill next block from the end */3218 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3219if(fseek(logfp, pos - cnt, SEEK_SET))3220returnerror("cannot seek back reflog for%s:%s",3221 refname,strerror(errno));3222 nread =fread(buf, cnt,1, logfp);3223if(nread !=1)3224returnerror("cannot read%dbytes from reflog for%s:%s",3225 cnt, refname,strerror(errno));3226 pos -= cnt;32273228 scanp = endp = buf + cnt;3229if(at_tail && scanp[-1] =='\n')3230/* Looking at the final LF at the end of the file */3231 scanp--;3232 at_tail =0;32333234while(buf < scanp) {3235/*3236 * terminating LF of the previous line, or the beginning3237 * of the buffer.3238 */3239char*bp;32403241 bp =find_beginning_of_line(buf, scanp);32423243if(*bp =='\n') {3244/*3245 * The newline is the end of the previous line,3246 * so we know we have complete line starting3247 * at (bp + 1). Prefix it onto any prior data3248 * we collected for the line and process it.3249 */3250strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3251 scanp = bp;3252 endp = bp +1;3253 ret =show_one_reflog_ent(&sb, fn, cb_data);3254strbuf_reset(&sb);3255if(ret)3256break;3257}else if(!pos) {3258/*3259 * We are at the start of the buffer, and the3260 * start of the file; there is no previous3261 * line, and we have everything for this one.3262 * Process it, and we can end the loop.3263 */3264strbuf_splice(&sb,0,0, buf, endp - buf);3265 ret =show_one_reflog_ent(&sb, fn, cb_data);3266strbuf_reset(&sb);3267break;3268}32693270if(bp == buf) {3271/*3272 * We are at the start of the buffer, and there3273 * is more file to read backwards. Which means3274 * we are in the middle of a line. Note that we3275 * may get here even if *bp was a newline; that3276 * just means we are at the exact end of the3277 * previous line, rather than some spot in the3278 * middle.3279 *3280 * Save away what we have to be combined with3281 * the data from the next read.3282 */3283strbuf_splice(&sb,0,0, buf, endp - buf);3284break;3285}3286}32873288}3289if(!ret && sb.len)3290die("BUG: reverse reflog parser had leftover data");32913292fclose(logfp);3293strbuf_release(&sb);3294return ret;3295}32963297intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3298{3299FILE*logfp;3300struct strbuf sb = STRBUF_INIT;3301int ret =0;33023303 logfp =fopen(git_path("logs/%s", refname),"r");3304if(!logfp)3305return-1;33063307while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3308 ret =show_one_reflog_ent(&sb, fn, cb_data);3309fclose(logfp);3310strbuf_release(&sb);3311return ret;3312}33133314struct files_reflog_iterator {3315struct ref_iterator base;33163317struct dir_iterator *dir_iterator;3318struct object_id oid;3319};33203321static intfiles_reflog_iterator_advance(struct ref_iterator *ref_iterator)3322{3323struct files_reflog_iterator *iter =3324(struct files_reflog_iterator *)ref_iterator;3325struct dir_iterator *diter = iter->dir_iterator;3326int ok;33273328while((ok =dir_iterator_advance(diter)) == ITER_OK) {3329int flags;33303331if(!S_ISREG(diter->st.st_mode))3332continue;3333if(diter->basename[0] =='.')3334continue;3335if(ends_with(diter->basename,".lock"))3336continue;33373338if(read_ref_full(diter->relative_path,0,3339 iter->oid.hash, &flags)) {3340error("bad ref for%s", diter->path.buf);3341continue;3342}33433344 iter->base.refname = diter->relative_path;3345 iter->base.oid = &iter->oid;3346 iter->base.flags = flags;3347return ITER_OK;3348}33493350 iter->dir_iterator = NULL;3351if(ref_iterator_abort(ref_iterator) == ITER_ERROR)3352 ok = ITER_ERROR;3353return ok;3354}33553356static intfiles_reflog_iterator_peel(struct ref_iterator *ref_iterator,3357struct object_id *peeled)3358{3359die("BUG: ref_iterator_peel() called for reflog_iterator");3360}33613362static intfiles_reflog_iterator_abort(struct ref_iterator *ref_iterator)3363{3364struct files_reflog_iterator *iter =3365(struct files_reflog_iterator *)ref_iterator;3366int ok = ITER_DONE;33673368if(iter->dir_iterator)3369 ok =dir_iterator_abort(iter->dir_iterator);33703371base_ref_iterator_free(ref_iterator);3372return ok;3373}33743375static struct ref_iterator_vtable files_reflog_iterator_vtable = {3376 files_reflog_iterator_advance,3377 files_reflog_iterator_peel,3378 files_reflog_iterator_abort3379};33803381struct ref_iterator *files_reflog_iterator_begin(void)3382{3383struct files_reflog_iterator *iter =xcalloc(1,sizeof(*iter));3384struct ref_iterator *ref_iterator = &iter->base;33853386base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3387 iter->dir_iterator =dir_iterator_begin(git_path("logs"));3388return ref_iterator;3389}33903391intfor_each_reflog(each_ref_fn fn,void*cb_data)3392{3393returndo_for_each_ref_iterator(files_reflog_iterator_begin(),3394 fn, cb_data);3395}33963397static intref_update_reject_duplicates(struct string_list *refnames,3398struct strbuf *err)3399{3400int i, n = refnames->nr;34013402assert(err);34033404for(i =1; i < n; i++)3405if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3406strbuf_addf(err,3407"multiple updates for ref '%s' not allowed.",3408 refnames->items[i].string);3409return1;3410}3411return0;3412}34133414/*3415 * If update is a direct update of head_ref (the reference pointed to3416 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3417 */3418static intsplit_head_update(struct ref_update *update,3419struct ref_transaction *transaction,3420const char*head_ref,3421struct string_list *affected_refnames,3422struct strbuf *err)3423{3424struct string_list_item *item;3425struct ref_update *new_update;34263427if((update->flags & REF_LOG_ONLY) ||3428(update->flags & REF_ISPRUNING) ||3429(update->flags & REF_UPDATE_VIA_HEAD))3430return0;34313432if(strcmp(update->refname, head_ref))3433return0;34343435/*3436 * First make sure that HEAD is not already in the3437 * transaction. This insertion is O(N) in the transaction3438 * size, but it happens at most once per transaction.3439 */3440 item =string_list_insert(affected_refnames,"HEAD");3441if(item->util) {3442/* An entry already existed */3443strbuf_addf(err,3444"multiple updates for 'HEAD' (including one "3445"via its referent '%s') are not allowed",3446 update->refname);3447return TRANSACTION_NAME_CONFLICT;3448}34493450 new_update =ref_transaction_add_update(3451 transaction,"HEAD",3452 update->flags | REF_LOG_ONLY | REF_NODEREF,3453 update->new_sha1, update->old_sha1,3454 update->msg);34553456 item->util = new_update;34573458return0;3459}34603461/*3462 * update is for a symref that points at referent and doesn't have3463 * REF_NODEREF set. Split it into two updates:3464 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3465 * - A new, separate update for the referent reference3466 * Note that the new update will itself be subject to splitting when3467 * the iteration gets to it.3468 */3469static intsplit_symref_update(struct ref_update *update,3470const char*referent,3471struct ref_transaction *transaction,3472struct string_list *affected_refnames,3473struct strbuf *err)3474{3475struct string_list_item *item;3476struct ref_update *new_update;3477unsigned int new_flags;34783479/*3480 * First make sure that referent is not already in the3481 * transaction. This insertion is O(N) in the transaction3482 * size, but it happens at most once per symref in a3483 * transaction.3484 */3485 item =string_list_insert(affected_refnames, referent);3486if(item->util) {3487/* An entry already existed */3488strbuf_addf(err,3489"multiple updates for '%s' (including one "3490"via symref '%s') are not allowed",3491 referent, update->refname);3492return TRANSACTION_NAME_CONFLICT;3493}34943495 new_flags = update->flags;3496if(!strcmp(update->refname,"HEAD")) {3497/*3498 * Record that the new update came via HEAD, so that3499 * when we process it, split_head_update() doesn't try3500 * to add another reflog update for HEAD. Note that3501 * this bit will be propagated if the new_update3502 * itself needs to be split.3503 */3504 new_flags |= REF_UPDATE_VIA_HEAD;3505}35063507 new_update =ref_transaction_add_update(3508 transaction, referent, new_flags,3509 update->new_sha1, update->old_sha1,3510 update->msg);35113512 new_update->parent_update = update;35133514/*3515 * Change the symbolic ref update to log only. Also, it3516 * doesn't need to check its old SHA-1 value, as that will be3517 * done when new_update is processed.3518 */3519 update->flags |= REF_LOG_ONLY | REF_NODEREF;3520 update->flags &= ~REF_HAVE_OLD;35213522 item->util = new_update;35233524return0;3525}35263527/*3528 * Return the refname under which update was originally requested.3529 */3530static const char*original_update_refname(struct ref_update *update)3531{3532while(update->parent_update)3533 update = update->parent_update;35343535return update->refname;3536}35373538/*3539 * Prepare for carrying out update:3540 * - Lock the reference referred to by update.3541 * - Read the reference under lock.3542 * - Check that its old SHA-1 value (if specified) is correct, and in3543 * any case record it in update->lock->old_oid for later use when3544 * writing the reflog.3545 * - If it is a symref update without REF_NODEREF, split it up into a3546 * REF_LOG_ONLY update of the symref and add a separate update for3547 * the referent to transaction.3548 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3549 * update of HEAD.3550 */3551static intlock_ref_for_update(struct ref_update *update,3552struct ref_transaction *transaction,3553const char*head_ref,3554struct string_list *affected_refnames,3555struct strbuf *err)3556{3557struct strbuf referent = STRBUF_INIT;3558int mustexist = (update->flags & REF_HAVE_OLD) &&3559!is_null_sha1(update->old_sha1);3560int ret;3561struct ref_lock *lock;35623563if((update->flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3564 update->flags |= REF_DELETING;35653566if(head_ref) {3567 ret =split_head_update(update, transaction, head_ref,3568 affected_refnames, err);3569if(ret)3570return ret;3571}35723573 ret =lock_raw_ref(update->refname, mustexist,3574 affected_refnames, NULL,3575&update->lock, &referent,3576&update->type, err);35773578if(ret) {3579char*reason;35803581 reason =strbuf_detach(err, NULL);3582strbuf_addf(err,"cannot lock ref '%s':%s",3583 update->refname, reason);3584free(reason);3585return ret;3586}35873588 lock = update->lock;35893590if(update->type & REF_ISSYMREF) {3591if(update->flags & REF_NODEREF) {3592/*3593 * We won't be reading the referent as part of3594 * the transaction, so we have to read it here3595 * to record and possibly check old_sha1:3596 */3597if(read_ref_full(update->refname,3598 mustexist ? RESOLVE_REF_READING :0,3599 lock->old_oid.hash, NULL)) {3600if(update->flags & REF_HAVE_OLD) {3601strbuf_addf(err,"cannot lock ref '%s': "3602"can't resolve old value",3603 update->refname);3604return TRANSACTION_GENERIC_ERROR;3605}else{3606hashclr(lock->old_oid.hash);3607}3608}3609if((update->flags & REF_HAVE_OLD) &&3610hashcmp(lock->old_oid.hash, update->old_sha1)) {3611strbuf_addf(err,"cannot lock ref '%s': "3612"is at%sbut expected%s",3613 update->refname,3614sha1_to_hex(lock->old_oid.hash),3615sha1_to_hex(update->old_sha1));3616return TRANSACTION_GENERIC_ERROR;3617}36183619}else{3620/*3621 * Create a new update for the reference this3622 * symref is pointing at. Also, we will record3623 * and verify old_sha1 for this update as part3624 * of processing the split-off update, so we3625 * don't have to do it here.3626 */3627 ret =split_symref_update(update, referent.buf, transaction,3628 affected_refnames, err);3629if(ret)3630return ret;3631}3632}else{3633struct ref_update *parent_update;36343635/*3636 * If this update is happening indirectly because of a3637 * symref update, record the old SHA-1 in the parent3638 * update:3639 */3640for(parent_update = update->parent_update;3641 parent_update;3642 parent_update = parent_update->parent_update) {3643oidcpy(&parent_update->lock->old_oid, &lock->old_oid);3644}36453646if((update->flags & REF_HAVE_OLD) &&3647hashcmp(lock->old_oid.hash, update->old_sha1)) {3648if(is_null_sha1(update->old_sha1))3649strbuf_addf(err,"cannot lock ref '%s': reference already exists",3650original_update_refname(update));3651else3652strbuf_addf(err,"cannot lock ref '%s': is at%sbut expected%s",3653original_update_refname(update),3654sha1_to_hex(lock->old_oid.hash),3655sha1_to_hex(update->old_sha1));36563657return TRANSACTION_GENERIC_ERROR;3658}3659}36603661if((update->flags & REF_HAVE_NEW) &&3662!(update->flags & REF_DELETING) &&3663!(update->flags & REF_LOG_ONLY)) {3664if(!(update->type & REF_ISSYMREF) &&3665!hashcmp(lock->old_oid.hash, update->new_sha1)) {3666/*3667 * The reference already has the desired3668 * value, so we don't need to write it.3669 */3670}else if(write_ref_to_lockfile(lock, update->new_sha1,3671 err)) {3672char*write_err =strbuf_detach(err, NULL);36733674/*3675 * The lock was freed upon failure of3676 * write_ref_to_lockfile():3677 */3678 update->lock = NULL;3679strbuf_addf(err,3680"cannot update the ref '%s':%s",3681 update->refname, write_err);3682free(write_err);3683return TRANSACTION_GENERIC_ERROR;3684}else{3685 update->flags |= REF_NEEDS_COMMIT;3686}3687}3688if(!(update->flags & REF_NEEDS_COMMIT)) {3689/*3690 * We didn't call write_ref_to_lockfile(), so3691 * the lockfile is still open. Close it to3692 * free up the file descriptor:3693 */3694if(close_ref(lock)) {3695strbuf_addf(err,"couldn't close '%s.lock'",3696 update->refname);3697return TRANSACTION_GENERIC_ERROR;3698}3699}3700return0;3701}37023703intref_transaction_commit(struct ref_transaction *transaction,3704struct strbuf *err)3705{3706struct files_ref_store *refs =3707get_files_ref_store(NULL,"ref_transaction_commit");3708int ret =0, i;3709struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3710struct string_list_item *ref_to_delete;3711struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3712char*head_ref = NULL;3713int head_type;3714struct object_id head_oid;37153716assert(err);37173718if(transaction->state != REF_TRANSACTION_OPEN)3719die("BUG: commit called for transaction that is not open");37203721if(!transaction->nr) {3722 transaction->state = REF_TRANSACTION_CLOSED;3723return0;3724}37253726/*3727 * Fail if a refname appears more than once in the3728 * transaction. (If we end up splitting up any updates using3729 * split_symref_update() or split_head_update(), those3730 * functions will check that the new updates don't have the3731 * same refname as any existing ones.)3732 */3733for(i =0; i < transaction->nr; i++) {3734struct ref_update *update = transaction->updates[i];3735struct string_list_item *item =3736string_list_append(&affected_refnames, update->refname);37373738/*3739 * We store a pointer to update in item->util, but at3740 * the moment we never use the value of this field3741 * except to check whether it is non-NULL.3742 */3743 item->util = update;3744}3745string_list_sort(&affected_refnames);3746if(ref_update_reject_duplicates(&affected_refnames, err)) {3747 ret = TRANSACTION_GENERIC_ERROR;3748goto cleanup;3749}37503751/*3752 * Special hack: If a branch is updated directly and HEAD3753 * points to it (may happen on the remote side of a push3754 * for example) then logically the HEAD reflog should be3755 * updated too.3756 *3757 * A generic solution would require reverse symref lookups,3758 * but finding all symrefs pointing to a given branch would be3759 * rather costly for this rare event (the direct update of a3760 * branch) to be worth it. So let's cheat and check with HEAD3761 * only, which should cover 99% of all usage scenarios (even3762 * 100% of the default ones).3763 *3764 * So if HEAD is a symbolic reference, then record the name of3765 * the reference that it points to. If we see an update of3766 * head_ref within the transaction, then split_head_update()3767 * arranges for the reflog of HEAD to be updated, too.3768 */3769 head_ref =resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3770 head_oid.hash, &head_type);37713772if(head_ref && !(head_type & REF_ISSYMREF)) {3773free(head_ref);3774 head_ref = NULL;3775}37763777/*3778 * Acquire all locks, verify old values if provided, check3779 * that new values are valid, and write new values to the3780 * lockfiles, ready to be activated. Only keep one lockfile3781 * open at a time to avoid running out of file descriptors.3782 */3783for(i =0; i < transaction->nr; i++) {3784struct ref_update *update = transaction->updates[i];37853786 ret =lock_ref_for_update(update, transaction, head_ref,3787&affected_refnames, err);3788if(ret)3789goto cleanup;3790}37913792/* Perform updates first so live commits remain referenced */3793for(i =0; i < transaction->nr; i++) {3794struct ref_update *update = transaction->updates[i];3795struct ref_lock *lock = update->lock;37963797if(update->flags & REF_NEEDS_COMMIT ||3798 update->flags & REF_LOG_ONLY) {3799if(log_ref_write(lock->ref_name, lock->old_oid.hash,3800 update->new_sha1,3801 update->msg, update->flags, err)) {3802char*old_msg =strbuf_detach(err, NULL);38033804strbuf_addf(err,"cannot update the ref '%s':%s",3805 lock->ref_name, old_msg);3806free(old_msg);3807unlock_ref(lock);3808 update->lock = NULL;3809 ret = TRANSACTION_GENERIC_ERROR;3810goto cleanup;3811}3812}3813if(update->flags & REF_NEEDS_COMMIT) {3814clear_loose_ref_cache(refs);3815if(commit_ref(lock)) {3816strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3817unlock_ref(lock);3818 update->lock = NULL;3819 ret = TRANSACTION_GENERIC_ERROR;3820goto cleanup;3821}3822}3823}3824/* Perform deletes now that updates are safely completed */3825for(i =0; i < transaction->nr; i++) {3826struct ref_update *update = transaction->updates[i];38273828if(update->flags & REF_DELETING &&3829!(update->flags & REF_LOG_ONLY)) {3830if(delete_ref_loose(update->lock, update->type, err)) {3831 ret = TRANSACTION_GENERIC_ERROR;3832goto cleanup;3833}38343835if(!(update->flags & REF_ISPRUNING))3836string_list_append(&refs_to_delete,3837 update->lock->ref_name);3838}3839}38403841if(repack_without_refs(&refs_to_delete, err)) {3842 ret = TRANSACTION_GENERIC_ERROR;3843goto cleanup;3844}3845for_each_string_list_item(ref_to_delete, &refs_to_delete)3846unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3847clear_loose_ref_cache(refs);38483849cleanup:3850 transaction->state = REF_TRANSACTION_CLOSED;38513852for(i =0; i < transaction->nr; i++)3853if(transaction->updates[i]->lock)3854unlock_ref(transaction->updates[i]->lock);3855string_list_clear(&refs_to_delete,0);3856free(head_ref);3857string_list_clear(&affected_refnames,0);38583859return ret;3860}38613862static intref_present(const char*refname,3863const struct object_id *oid,int flags,void*cb_data)3864{3865struct string_list *affected_refnames = cb_data;38663867returnstring_list_has_string(affected_refnames, refname);3868}38693870intinitial_ref_transaction_commit(struct ref_transaction *transaction,3871struct strbuf *err)3872{3873struct files_ref_store *refs =3874get_files_ref_store(NULL,"initial_ref_transaction_commit");3875int ret =0, i;3876struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38773878assert(err);38793880if(transaction->state != REF_TRANSACTION_OPEN)3881die("BUG: commit called for transaction that is not open");38823883/* Fail if a refname appears more than once in the transaction: */3884for(i =0; i < transaction->nr; i++)3885string_list_append(&affected_refnames,3886 transaction->updates[i]->refname);3887string_list_sort(&affected_refnames);3888if(ref_update_reject_duplicates(&affected_refnames, err)) {3889 ret = TRANSACTION_GENERIC_ERROR;3890goto cleanup;3891}38923893/*3894 * It's really undefined to call this function in an active3895 * repository or when there are existing references: we are3896 * only locking and changing packed-refs, so (1) any3897 * simultaneous processes might try to change a reference at3898 * the same time we do, and (2) any existing loose versions of3899 * the references that we are setting would have precedence3900 * over our values. But some remote helpers create the remote3901 * "HEAD" and "master" branches before calling this function,3902 * so here we really only check that none of the references3903 * that we are creating already exists.3904 */3905if(for_each_rawref(ref_present, &affected_refnames))3906die("BUG: initial ref transaction called with existing refs");39073908for(i =0; i < transaction->nr; i++) {3909struct ref_update *update = transaction->updates[i];39103911if((update->flags & REF_HAVE_OLD) &&3912!is_null_sha1(update->old_sha1))3913die("BUG: initial ref transaction with old_sha1 set");3914if(verify_refname_available(update->refname,3915&affected_refnames, NULL,3916 err)) {3917 ret = TRANSACTION_NAME_CONFLICT;3918goto cleanup;3919}3920}39213922if(lock_packed_refs(0)) {3923strbuf_addf(err,"unable to lock packed-refs file:%s",3924strerror(errno));3925 ret = TRANSACTION_GENERIC_ERROR;3926goto cleanup;3927}39283929for(i =0; i < transaction->nr; i++) {3930struct ref_update *update = transaction->updates[i];39313932if((update->flags & REF_HAVE_NEW) &&3933!is_null_sha1(update->new_sha1))3934add_packed_ref(refs, update->refname, update->new_sha1);3935}39363937if(commit_packed_refs()) {3938strbuf_addf(err,"unable to commit packed-refs file:%s",3939strerror(errno));3940 ret = TRANSACTION_GENERIC_ERROR;3941goto cleanup;3942}39433944cleanup:3945 transaction->state = REF_TRANSACTION_CLOSED;3946string_list_clear(&affected_refnames,0);3947return ret;3948}39493950struct expire_reflog_cb {3951unsigned int flags;3952 reflog_expiry_should_prune_fn *should_prune_fn;3953void*policy_cb;3954FILE*newlog;3955unsigned char last_kept_sha1[20];3956};39573958static intexpire_reflog_ent(unsigned char*osha1,unsigned char*nsha1,3959const char*email,unsigned long timestamp,int tz,3960const char*message,void*cb_data)3961{3962struct expire_reflog_cb *cb = cb_data;3963struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39643965if(cb->flags & EXPIRE_REFLOGS_REWRITE)3966 osha1 = cb->last_kept_sha1;39673968if((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3969 message, policy_cb)) {3970if(!cb->newlog)3971printf("would prune%s", message);3972else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3973printf("prune%s", message);3974}else{3975if(cb->newlog) {3976fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",3977sha1_to_hex(osha1),sha1_to_hex(nsha1),3978 email, timestamp, tz, message);3979hashcpy(cb->last_kept_sha1, nsha1);3980}3981if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3982printf("keep%s", message);3983}3984return0;3985}39863987intreflog_expire(const char*refname,const unsigned char*sha1,3988unsigned int flags,3989 reflog_expiry_prepare_fn prepare_fn,3990 reflog_expiry_should_prune_fn should_prune_fn,3991 reflog_expiry_cleanup_fn cleanup_fn,3992void*policy_cb_data)3993{3994static struct lock_file reflog_lock;3995struct expire_reflog_cb cb;3996struct ref_lock *lock;3997char*log_file;3998int status =0;3999int type;4000struct strbuf err = STRBUF_INIT;40014002memset(&cb,0,sizeof(cb));4003 cb.flags = flags;4004 cb.policy_cb = policy_cb_data;4005 cb.should_prune_fn = should_prune_fn;40064007/*4008 * The reflog file is locked by holding the lock on the4009 * reference itself, plus we might need to update the4010 * reference if --updateref was specified:4011 */4012 lock =lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF,4013&type, &err);4014if(!lock) {4015error("cannot lock ref '%s':%s", refname, err.buf);4016strbuf_release(&err);4017return-1;4018}4019if(!reflog_exists(refname)) {4020unlock_ref(lock);4021return0;4022}40234024 log_file =git_pathdup("logs/%s", refname);4025if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4026/*4027 * Even though holding $GIT_DIR/logs/$reflog.lock has4028 * no locking implications, we use the lock_file4029 * machinery here anyway because it does a lot of the4030 * work we need, including cleaning up if the program4031 * exits unexpectedly.4032 */4033if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4034struct strbuf err = STRBUF_INIT;4035unable_to_lock_message(log_file, errno, &err);4036error("%s", err.buf);4037strbuf_release(&err);4038goto failure;4039}4040 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4041if(!cb.newlog) {4042error("cannot fdopen%s(%s)",4043get_lock_file_path(&reflog_lock),strerror(errno));4044goto failure;4045}4046}40474048(*prepare_fn)(refname, sha1, cb.policy_cb);4049for_each_reflog_ent(refname, expire_reflog_ent, &cb);4050(*cleanup_fn)(cb.policy_cb);40514052if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4053/*4054 * It doesn't make sense to adjust a reference pointed4055 * to by a symbolic ref based on expiring entries in4056 * the symbolic reference's reflog. Nor can we update4057 * a reference if there are no remaining reflog4058 * entries.4059 */4060int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4061!(type & REF_ISSYMREF) &&4062!is_null_sha1(cb.last_kept_sha1);40634064if(close_lock_file(&reflog_lock)) {4065 status |=error("couldn't write%s:%s", log_file,4066strerror(errno));4067}else if(update &&4068(write_in_full(get_lock_file_fd(lock->lk),4069sha1_to_hex(cb.last_kept_sha1),40) !=40||4070write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||4071close_ref(lock) <0)) {4072 status |=error("couldn't write%s",4073get_lock_file_path(lock->lk));4074rollback_lock_file(&reflog_lock);4075}else if(commit_lock_file(&reflog_lock)) {4076 status |=error("unable to write reflog '%s' (%s)",4077 log_file,strerror(errno));4078}else if(update &&commit_ref(lock)) {4079 status |=error("couldn't set%s", lock->ref_name);4080}4081}4082free(log_file);4083unlock_ref(lock);4084return status;40854086 failure:4087rollback_lock_file(&reflog_lock);4088free(log_file);4089unlock_ref(lock);4090return-1;4091}40924093struct ref_storage_be refs_be_files = {4094 NULL,4095"files",4096 files_ref_store_create4097};