1#include"../cache.h" 2#include"../refs.h" 3#include"refs-internal.h" 4#include"../iterator.h" 5#include"../dir-iterator.h" 6#include"../lockfile.h" 7#include"../object.h" 8#include"../dir.h" 9 10struct ref_lock { 11char*ref_name; 12struct lock_file *lk; 13struct object_id old_oid; 14}; 15 16struct ref_entry; 17 18/* 19 * Information used (along with the information in ref_entry) to 20 * describe a single cached reference. This data structure only 21 * occurs embedded in a union in struct ref_entry, and only when 22 * (ref_entry->flag & REF_DIR) is zero. 23 */ 24struct ref_value { 25/* 26 * The name of the object to which this reference resolves 27 * (which may be a tag object). If REF_ISBROKEN, this is 28 * null. If REF_ISSYMREF, then this is the name of the object 29 * referred to by the last reference in the symlink chain. 30 */ 31struct object_id oid; 32 33/* 34 * If REF_KNOWS_PEELED, then this field holds the peeled value 35 * of this reference, or null if the reference is known not to 36 * be peelable. See the documentation for peel_ref() for an 37 * exact definition of "peelable". 38 */ 39struct object_id peeled; 40}; 41 42struct files_ref_store; 43 44/* 45 * Information used (along with the information in ref_entry) to 46 * describe a level in the hierarchy of references. This data 47 * structure only occurs embedded in a union in struct ref_entry, and 48 * only when (ref_entry.flag & REF_DIR) is set. In that case, 49 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 50 * in the directory have already been read: 51 * 52 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 53 * or packed references, already read. 54 * 55 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 56 * references that hasn't been read yet (nor has any of its 57 * subdirectories). 58 * 59 * Entries within a directory are stored within a growable array of 60 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 61 * sorted are sorted by their component name in strcmp() order and the 62 * remaining entries are unsorted. 63 * 64 * Loose references are read lazily, one directory at a time. When a 65 * directory of loose references is read, then all of the references 66 * in that directory are stored, and REF_INCOMPLETE stubs are created 67 * for any subdirectories, but the subdirectories themselves are not 68 * read. The reading is triggered by get_ref_dir(). 69 */ 70struct ref_dir { 71int nr, alloc; 72 73/* 74 * Entries with index 0 <= i < sorted are sorted by name. New 75 * entries are appended to the list unsorted, and are sorted 76 * only when required; thus we avoid the need to sort the list 77 * after the addition of every reference. 78 */ 79int sorted; 80 81/* A pointer to the files_ref_store that contains this ref_dir. */ 82struct files_ref_store *ref_store; 83 84struct ref_entry **entries; 85}; 86 87/* 88 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 89 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 90 * public values; see refs.h. 91 */ 92 93/* 94 * The field ref_entry->u.value.peeled of this value entry contains 95 * the correct peeled value for the reference, which might be 96 * null_sha1 if the reference is not a tag or if it is broken. 97 */ 98#define REF_KNOWS_PEELED 0x10 99 100/* ref_entry represents a directory of references */ 101#define REF_DIR 0x20 102 103/* 104 * Entry has not yet been read from disk (used only for REF_DIR 105 * entries representing loose references) 106 */ 107#define REF_INCOMPLETE 0x40 108 109/* 110 * A ref_entry represents either a reference or a "subdirectory" of 111 * references. 112 * 113 * Each directory in the reference namespace is represented by a 114 * ref_entry with (flags & REF_DIR) set and containing a subdir member 115 * that holds the entries in that directory that have been read so 116 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 117 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 118 * used for loose reference directories. 119 * 120 * References are represented by a ref_entry with (flags & REF_DIR) 121 * unset and a value member that describes the reference's value. The 122 * flag member is at the ref_entry level, but it is also needed to 123 * interpret the contents of the value field (in other words, a 124 * ref_value object is not very much use without the enclosing 125 * ref_entry). 126 * 127 * Reference names cannot end with slash and directories' names are 128 * always stored with a trailing slash (except for the top-level 129 * directory, which is always denoted by ""). This has two nice 130 * consequences: (1) when the entries in each subdir are sorted 131 * lexicographically by name (as they usually are), the references in 132 * a whole tree can be generated in lexicographic order by traversing 133 * the tree in left-to-right, depth-first order; (2) the names of 134 * references and subdirectories cannot conflict, and therefore the 135 * presence of an empty subdirectory does not block the creation of a 136 * similarly-named reference. (The fact that reference names with the 137 * same leading components can conflict *with each other* is a 138 * separate issue that is regulated by verify_refname_available().) 139 * 140 * Please note that the name field contains the fully-qualified 141 * reference (or subdirectory) name. Space could be saved by only 142 * storing the relative names. But that would require the full names 143 * to be generated on the fly when iterating in do_for_each_ref(), and 144 * would break callback functions, who have always been able to assume 145 * that the name strings that they are passed will not be freed during 146 * the iteration. 147 */ 148struct ref_entry { 149unsigned char flag;/* ISSYMREF? ISPACKED? */ 150union{ 151struct ref_value value;/* if not (flags&REF_DIR) */ 152struct ref_dir subdir;/* if (flags&REF_DIR) */ 153} u; 154/* 155 * The full name of the reference (e.g., "refs/heads/master") 156 * or the full name of the directory with a trailing slash 157 * (e.g., "refs/heads/"): 158 */ 159char name[FLEX_ARRAY]; 160}; 161 162static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 163static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len); 164static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 165const char*dirname,size_t len, 166int incomplete); 167static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry); 168static intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1, 169const unsigned char*new_sha1,const char*msg, 170int flags,struct strbuf *err); 171 172static struct ref_dir *get_ref_dir(struct ref_entry *entry) 173{ 174struct ref_dir *dir; 175assert(entry->flag & REF_DIR); 176 dir = &entry->u.subdir; 177if(entry->flag & REF_INCOMPLETE) { 178read_loose_refs(entry->name, dir); 179 180/* 181 * Manually add refs/bisect, which, being 182 * per-worktree, might not appear in the directory 183 * listing for refs/ in the main repo. 184 */ 185if(!strcmp(entry->name,"refs/")) { 186int pos =search_ref_dir(dir,"refs/bisect/",12); 187if(pos <0) { 188struct ref_entry *child_entry; 189 child_entry =create_dir_entry(dir->ref_store, 190"refs/bisect/", 19112,1); 192add_entry_to_dir(dir, child_entry); 193read_loose_refs("refs/bisect", 194&child_entry->u.subdir); 195} 196} 197 entry->flag &= ~REF_INCOMPLETE; 198} 199return dir; 200} 201 202static struct ref_entry *create_ref_entry(const char*refname, 203const unsigned char*sha1,int flag, 204int check_name) 205{ 206struct ref_entry *ref; 207 208if(check_name && 209check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 210die("Reference has invalid format: '%s'", refname); 211FLEX_ALLOC_STR(ref, name, refname); 212hashcpy(ref->u.value.oid.hash, sha1); 213oidclr(&ref->u.value.peeled); 214 ref->flag = flag; 215return ref; 216} 217 218static voidclear_ref_dir(struct ref_dir *dir); 219 220static voidfree_ref_entry(struct ref_entry *entry) 221{ 222if(entry->flag & REF_DIR) { 223/* 224 * Do not use get_ref_dir() here, as that might 225 * trigger the reading of loose refs. 226 */ 227clear_ref_dir(&entry->u.subdir); 228} 229free(entry); 230} 231 232/* 233 * Add a ref_entry to the end of dir (unsorted). Entry is always 234 * stored directly in dir; no recursion into subdirectories is 235 * done. 236 */ 237static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 238{ 239ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 240 dir->entries[dir->nr++] = entry; 241/* optimize for the case that entries are added in order */ 242if(dir->nr ==1|| 243(dir->nr == dir->sorted +1&& 244strcmp(dir->entries[dir->nr -2]->name, 245 dir->entries[dir->nr -1]->name) <0)) 246 dir->sorted = dir->nr; 247} 248 249/* 250 * Clear and free all entries in dir, recursively. 251 */ 252static voidclear_ref_dir(struct ref_dir *dir) 253{ 254int i; 255for(i =0; i < dir->nr; i++) 256free_ref_entry(dir->entries[i]); 257free(dir->entries); 258 dir->sorted = dir->nr = dir->alloc =0; 259 dir->entries = NULL; 260} 261 262/* 263 * Create a struct ref_entry object for the specified dirname. 264 * dirname is the name of the directory with a trailing slash (e.g., 265 * "refs/heads/") or "" for the top-level directory. 266 */ 267static struct ref_entry *create_dir_entry(struct files_ref_store *ref_store, 268const char*dirname,size_t len, 269int incomplete) 270{ 271struct ref_entry *direntry; 272FLEX_ALLOC_MEM(direntry, name, dirname, len); 273 direntry->u.subdir.ref_store = ref_store; 274 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 275return direntry; 276} 277 278static intref_entry_cmp(const void*a,const void*b) 279{ 280struct ref_entry *one = *(struct ref_entry **)a; 281struct ref_entry *two = *(struct ref_entry **)b; 282returnstrcmp(one->name, two->name); 283} 284 285static voidsort_ref_dir(struct ref_dir *dir); 286 287struct string_slice { 288size_t len; 289const char*str; 290}; 291 292static intref_entry_cmp_sslice(const void*key_,const void*ent_) 293{ 294const struct string_slice *key = key_; 295const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 296int cmp =strncmp(key->str, ent->name, key->len); 297if(cmp) 298return cmp; 299return'\0'- (unsigned char)ent->name[key->len]; 300} 301 302/* 303 * Return the index of the entry with the given refname from the 304 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 305 * no such entry is found. dir must already be complete. 306 */ 307static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 308{ 309struct ref_entry **r; 310struct string_slice key; 311 312if(refname == NULL || !dir->nr) 313return-1; 314 315sort_ref_dir(dir); 316 key.len = len; 317 key.str = refname; 318 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 319 ref_entry_cmp_sslice); 320 321if(r == NULL) 322return-1; 323 324return r - dir->entries; 325} 326 327/* 328 * Search for a directory entry directly within dir (without 329 * recursing). Sort dir if necessary. subdirname must be a directory 330 * name (i.e., end in '/'). If mkdir is set, then create the 331 * directory if it is missing; otherwise, return NULL if the desired 332 * directory cannot be found. dir must already be complete. 333 */ 334static struct ref_dir *search_for_subdir(struct ref_dir *dir, 335const char*subdirname,size_t len, 336int mkdir) 337{ 338int entry_index =search_ref_dir(dir, subdirname, len); 339struct ref_entry *entry; 340if(entry_index == -1) { 341if(!mkdir) 342return NULL; 343/* 344 * Since dir is complete, the absence of a subdir 345 * means that the subdir really doesn't exist; 346 * therefore, create an empty record for it but mark 347 * the record complete. 348 */ 349 entry =create_dir_entry(dir->ref_store, subdirname, len,0); 350add_entry_to_dir(dir, entry); 351}else{ 352 entry = dir->entries[entry_index]; 353} 354returnget_ref_dir(entry); 355} 356 357/* 358 * If refname is a reference name, find the ref_dir within the dir 359 * tree that should hold refname. If refname is a directory name 360 * (i.e., ends in '/'), then return that ref_dir itself. dir must 361 * represent the top-level directory and must already be complete. 362 * Sort ref_dirs and recurse into subdirectories as necessary. If 363 * mkdir is set, then create any missing directories; otherwise, 364 * return NULL if the desired directory cannot be found. 365 */ 366static struct ref_dir *find_containing_dir(struct ref_dir *dir, 367const char*refname,int mkdir) 368{ 369const char*slash; 370for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 371size_t dirnamelen = slash - refname +1; 372struct ref_dir *subdir; 373 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 374if(!subdir) { 375 dir = NULL; 376break; 377} 378 dir = subdir; 379} 380 381return dir; 382} 383 384/* 385 * Find the value entry with the given name in dir, sorting ref_dirs 386 * and recursing into subdirectories as necessary. If the name is not 387 * found or it corresponds to a directory entry, return NULL. 388 */ 389static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 390{ 391int entry_index; 392struct ref_entry *entry; 393 dir =find_containing_dir(dir, refname,0); 394if(!dir) 395return NULL; 396 entry_index =search_ref_dir(dir, refname,strlen(refname)); 397if(entry_index == -1) 398return NULL; 399 entry = dir->entries[entry_index]; 400return(entry->flag & REF_DIR) ? NULL : entry; 401} 402 403/* 404 * Remove the entry with the given name from dir, recursing into 405 * subdirectories as necessary. If refname is the name of a directory 406 * (i.e., ends with '/'), then remove the directory and its contents. 407 * If the removal was successful, return the number of entries 408 * remaining in the directory entry that contained the deleted entry. 409 * If the name was not found, return -1. Please note that this 410 * function only deletes the entry from the cache; it does not delete 411 * it from the filesystem or ensure that other cache entries (which 412 * might be symbolic references to the removed entry) are updated. 413 * Nor does it remove any containing dir entries that might be made 414 * empty by the removal. dir must represent the top-level directory 415 * and must already be complete. 416 */ 417static intremove_entry(struct ref_dir *dir,const char*refname) 418{ 419int refname_len =strlen(refname); 420int entry_index; 421struct ref_entry *entry; 422int is_dir = refname[refname_len -1] =='/'; 423if(is_dir) { 424/* 425 * refname represents a reference directory. Remove 426 * the trailing slash; otherwise we will get the 427 * directory *representing* refname rather than the 428 * one *containing* it. 429 */ 430char*dirname =xmemdupz(refname, refname_len -1); 431 dir =find_containing_dir(dir, dirname,0); 432free(dirname); 433}else{ 434 dir =find_containing_dir(dir, refname,0); 435} 436if(!dir) 437return-1; 438 entry_index =search_ref_dir(dir, refname, refname_len); 439if(entry_index == -1) 440return-1; 441 entry = dir->entries[entry_index]; 442 443memmove(&dir->entries[entry_index], 444&dir->entries[entry_index +1], 445(dir->nr - entry_index -1) *sizeof(*dir->entries) 446); 447 dir->nr--; 448if(dir->sorted > entry_index) 449 dir->sorted--; 450free_ref_entry(entry); 451return dir->nr; 452} 453 454/* 455 * Add a ref_entry to the ref_dir (unsorted), recursing into 456 * subdirectories as necessary. dir must represent the top-level 457 * directory. Return 0 on success. 458 */ 459static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 460{ 461 dir =find_containing_dir(dir, ref->name,1); 462if(!dir) 463return-1; 464add_entry_to_dir(dir, ref); 465return0; 466} 467 468/* 469 * Emit a warning and return true iff ref1 and ref2 have the same name 470 * and the same sha1. Die if they have the same name but different 471 * sha1s. 472 */ 473static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 474{ 475if(strcmp(ref1->name, ref2->name)) 476return0; 477 478/* Duplicate name; make sure that they don't conflict: */ 479 480if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 481/* This is impossible by construction */ 482die("Reference directory conflict:%s", ref1->name); 483 484if(oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) 485die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 486 487warning("Duplicated ref:%s", ref1->name); 488return1; 489} 490 491/* 492 * Sort the entries in dir non-recursively (if they are not already 493 * sorted) and remove any duplicate entries. 494 */ 495static voidsort_ref_dir(struct ref_dir *dir) 496{ 497int i, j; 498struct ref_entry *last = NULL; 499 500/* 501 * This check also prevents passing a zero-length array to qsort(), 502 * which is a problem on some platforms. 503 */ 504if(dir->sorted == dir->nr) 505return; 506 507QSORT(dir->entries, dir->nr, ref_entry_cmp); 508 509/* Remove any duplicates: */ 510for(i =0, j =0; j < dir->nr; j++) { 511struct ref_entry *entry = dir->entries[j]; 512if(last &&is_dup_ref(last, entry)) 513free_ref_entry(entry); 514else 515 last = dir->entries[i++] = entry; 516} 517 dir->sorted = dir->nr = i; 518} 519 520/* 521 * Return true if refname, which has the specified oid and flags, can 522 * be resolved to an object in the database. If the referred-to object 523 * does not exist, emit a warning and return false. 524 */ 525static intref_resolves_to_object(const char*refname, 526const struct object_id *oid, 527unsigned int flags) 528{ 529if(flags & REF_ISBROKEN) 530return0; 531if(!has_sha1_file(oid->hash)) { 532error("%sdoes not point to a valid object!", refname); 533return0; 534} 535return1; 536} 537 538/* 539 * Return true if the reference described by entry can be resolved to 540 * an object in the database; otherwise, emit a warning and return 541 * false. 542 */ 543static intentry_resolves_to_object(struct ref_entry *entry) 544{ 545returnref_resolves_to_object(entry->name, 546&entry->u.value.oid, entry->flag); 547} 548 549typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 550 551/* 552 * Call fn for each reference in dir that has index in the range 553 * offset <= index < dir->nr. Recurse into subdirectories that are in 554 * that index range, sorting them before iterating. This function 555 * does not sort dir itself; it should be sorted beforehand. fn is 556 * called for all references, including broken ones. 557 */ 558static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 559 each_ref_entry_fn fn,void*cb_data) 560{ 561int i; 562assert(dir->sorted == dir->nr); 563for(i = offset; i < dir->nr; i++) { 564struct ref_entry *entry = dir->entries[i]; 565int retval; 566if(entry->flag & REF_DIR) { 567struct ref_dir *subdir =get_ref_dir(entry); 568sort_ref_dir(subdir); 569 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 570}else{ 571 retval =fn(entry, cb_data); 572} 573if(retval) 574return retval; 575} 576return0; 577} 578 579/* 580 * Load all of the refs from the dir into our in-memory cache. The hard work 581 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 582 * through all of the sub-directories. We do not even need to care about 583 * sorting, as traversal order does not matter to us. 584 */ 585static voidprime_ref_dir(struct ref_dir *dir) 586{ 587int i; 588for(i =0; i < dir->nr; i++) { 589struct ref_entry *entry = dir->entries[i]; 590if(entry->flag & REF_DIR) 591prime_ref_dir(get_ref_dir(entry)); 592} 593} 594 595/* 596 * A level in the reference hierarchy that is currently being iterated 597 * through. 598 */ 599struct cache_ref_iterator_level { 600/* 601 * The ref_dir being iterated over at this level. The ref_dir 602 * is sorted before being stored here. 603 */ 604struct ref_dir *dir; 605 606/* 607 * The index of the current entry within dir (which might 608 * itself be a directory). If index == -1, then the iteration 609 * hasn't yet begun. If index == dir->nr, then the iteration 610 * through this level is over. 611 */ 612int index; 613}; 614 615/* 616 * Represent an iteration through a ref_dir in the memory cache. The 617 * iteration recurses through subdirectories. 618 */ 619struct cache_ref_iterator { 620struct ref_iterator base; 621 622/* 623 * The number of levels currently on the stack. This is always 624 * at least 1, because when it becomes zero the iteration is 625 * ended and this struct is freed. 626 */ 627size_t levels_nr; 628 629/* The number of levels that have been allocated on the stack */ 630size_t levels_alloc; 631 632/* 633 * A stack of levels. levels[0] is the uppermost level that is 634 * being iterated over in this iteration. (This is not 635 * necessary the top level in the references hierarchy. If we 636 * are iterating through a subtree, then levels[0] will hold 637 * the ref_dir for that subtree, and subsequent levels will go 638 * on from there.) 639 */ 640struct cache_ref_iterator_level *levels; 641}; 642 643static intcache_ref_iterator_advance(struct ref_iterator *ref_iterator) 644{ 645struct cache_ref_iterator *iter = 646(struct cache_ref_iterator *)ref_iterator; 647 648while(1) { 649struct cache_ref_iterator_level *level = 650&iter->levels[iter->levels_nr -1]; 651struct ref_dir *dir = level->dir; 652struct ref_entry *entry; 653 654if(level->index == -1) 655sort_ref_dir(dir); 656 657if(++level->index == level->dir->nr) { 658/* This level is exhausted; pop up a level */ 659if(--iter->levels_nr ==0) 660returnref_iterator_abort(ref_iterator); 661 662continue; 663} 664 665 entry = dir->entries[level->index]; 666 667if(entry->flag & REF_DIR) { 668/* push down a level */ 669ALLOC_GROW(iter->levels, iter->levels_nr +1, 670 iter->levels_alloc); 671 672 level = &iter->levels[iter->levels_nr++]; 673 level->dir =get_ref_dir(entry); 674 level->index = -1; 675}else{ 676 iter->base.refname = entry->name; 677 iter->base.oid = &entry->u.value.oid; 678 iter->base.flags = entry->flag; 679return ITER_OK; 680} 681} 682} 683 684static enum peel_status peel_entry(struct ref_entry *entry,int repeel); 685 686static intcache_ref_iterator_peel(struct ref_iterator *ref_iterator, 687struct object_id *peeled) 688{ 689struct cache_ref_iterator *iter = 690(struct cache_ref_iterator *)ref_iterator; 691struct cache_ref_iterator_level *level; 692struct ref_entry *entry; 693 694 level = &iter->levels[iter->levels_nr -1]; 695 696if(level->index == -1) 697die("BUG: peel called before advance for cache iterator"); 698 699 entry = level->dir->entries[level->index]; 700 701if(peel_entry(entry,0)) 702return-1; 703oidcpy(peeled, &entry->u.value.peeled); 704return0; 705} 706 707static intcache_ref_iterator_abort(struct ref_iterator *ref_iterator) 708{ 709struct cache_ref_iterator *iter = 710(struct cache_ref_iterator *)ref_iterator; 711 712free(iter->levels); 713base_ref_iterator_free(ref_iterator); 714return ITER_DONE; 715} 716 717static struct ref_iterator_vtable cache_ref_iterator_vtable = { 718 cache_ref_iterator_advance, 719 cache_ref_iterator_peel, 720 cache_ref_iterator_abort 721}; 722 723static struct ref_iterator *cache_ref_iterator_begin(struct ref_dir *dir) 724{ 725struct cache_ref_iterator *iter; 726struct ref_iterator *ref_iterator; 727struct cache_ref_iterator_level *level; 728 729 iter =xcalloc(1,sizeof(*iter)); 730 ref_iterator = &iter->base; 731base_ref_iterator_init(ref_iterator, &cache_ref_iterator_vtable); 732ALLOC_GROW(iter->levels,10, iter->levels_alloc); 733 734 iter->levels_nr =1; 735 level = &iter->levels[0]; 736 level->index = -1; 737 level->dir = dir; 738 739return ref_iterator; 740} 741 742struct nonmatching_ref_data { 743const struct string_list *skip; 744const char*conflicting_refname; 745}; 746 747static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 748{ 749struct nonmatching_ref_data *data = vdata; 750 751if(data->skip &&string_list_has_string(data->skip, entry->name)) 752return0; 753 754 data->conflicting_refname = entry->name; 755return1; 756} 757 758/* 759 * Return 0 if a reference named refname could be created without 760 * conflicting with the name of an existing reference in dir. 761 * See verify_refname_available for more information. 762 */ 763static intverify_refname_available_dir(const char*refname, 764const struct string_list *extras, 765const struct string_list *skip, 766struct ref_dir *dir, 767struct strbuf *err) 768{ 769const char*slash; 770const char*extra_refname; 771int pos; 772struct strbuf dirname = STRBUF_INIT; 773int ret = -1; 774 775/* 776 * For the sake of comments in this function, suppose that 777 * refname is "refs/foo/bar". 778 */ 779 780assert(err); 781 782strbuf_grow(&dirname,strlen(refname) +1); 783for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 784/* Expand dirname to the new prefix, not including the trailing slash: */ 785strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); 786 787/* 788 * We are still at a leading dir of the refname (e.g., 789 * "refs/foo"; if there is a reference with that name, 790 * it is a conflict, *unless* it is in skip. 791 */ 792if(dir) { 793 pos =search_ref_dir(dir, dirname.buf, dirname.len); 794if(pos >=0&& 795(!skip || !string_list_has_string(skip, dirname.buf))) { 796/* 797 * We found a reference whose name is 798 * a proper prefix of refname; e.g., 799 * "refs/foo", and is not in skip. 800 */ 801strbuf_addf(err,"'%s' exists; cannot create '%s'", 802 dirname.buf, refname); 803goto cleanup; 804} 805} 806 807if(extras &&string_list_has_string(extras, dirname.buf) && 808(!skip || !string_list_has_string(skip, dirname.buf))) { 809strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 810 refname, dirname.buf); 811goto cleanup; 812} 813 814/* 815 * Otherwise, we can try to continue our search with 816 * the next component. So try to look up the 817 * directory, e.g., "refs/foo/". If we come up empty, 818 * we know there is nothing under this whole prefix, 819 * but even in that case we still have to continue the 820 * search for conflicts with extras. 821 */ 822strbuf_addch(&dirname,'/'); 823if(dir) { 824 pos =search_ref_dir(dir, dirname.buf, dirname.len); 825if(pos <0) { 826/* 827 * There was no directory "refs/foo/", 828 * so there is nothing under this 829 * whole prefix. So there is no need 830 * to continue looking for conflicting 831 * references. But we need to continue 832 * looking for conflicting extras. 833 */ 834 dir = NULL; 835}else{ 836 dir =get_ref_dir(dir->entries[pos]); 837} 838} 839} 840 841/* 842 * We are at the leaf of our refname (e.g., "refs/foo/bar"). 843 * There is no point in searching for a reference with that 844 * name, because a refname isn't considered to conflict with 845 * itself. But we still need to check for references whose 846 * names are in the "refs/foo/bar/" namespace, because they 847 * *do* conflict. 848 */ 849strbuf_addstr(&dirname, refname + dirname.len); 850strbuf_addch(&dirname,'/'); 851 852if(dir) { 853 pos =search_ref_dir(dir, dirname.buf, dirname.len); 854 855if(pos >=0) { 856/* 857 * We found a directory named "$refname/" 858 * (e.g., "refs/foo/bar/"). It is a problem 859 * iff it contains any ref that is not in 860 * "skip". 861 */ 862struct nonmatching_ref_data data; 863 864 data.skip = skip; 865 data.conflicting_refname = NULL; 866 dir =get_ref_dir(dir->entries[pos]); 867sort_ref_dir(dir); 868if(do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) { 869strbuf_addf(err,"'%s' exists; cannot create '%s'", 870 data.conflicting_refname, refname); 871goto cleanup; 872} 873} 874} 875 876 extra_refname =find_descendant_ref(dirname.buf, extras, skip); 877if(extra_refname) 878strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 879 refname, extra_refname); 880else 881 ret =0; 882 883cleanup: 884strbuf_release(&dirname); 885return ret; 886} 887 888struct packed_ref_cache { 889struct ref_entry *root; 890 891/* 892 * Count of references to the data structure in this instance, 893 * including the pointer from files_ref_store::packed if any. 894 * The data will not be freed as long as the reference count 895 * is nonzero. 896 */ 897unsigned int referrers; 898 899/* 900 * Iff the packed-refs file associated with this instance is 901 * currently locked for writing, this points at the associated 902 * lock (which is owned by somebody else). The referrer count 903 * is also incremented when the file is locked and decremented 904 * when it is unlocked. 905 */ 906struct lock_file *lock; 907 908/* The metadata from when this packed-refs cache was read */ 909struct stat_validity validity; 910}; 911 912/* 913 * Future: need to be in "struct repository" 914 * when doing a full libification. 915 */ 916struct files_ref_store { 917struct ref_store base; 918 919/* 920 * The name of the submodule represented by this object, or 921 * NULL if it represents the main repository's reference 922 * store: 923 */ 924const char*submodule; 925 926struct ref_entry *loose; 927struct packed_ref_cache *packed; 928}; 929 930/* Lock used for the main packed-refs file: */ 931static struct lock_file packlock; 932 933/* 934 * Increment the reference count of *packed_refs. 935 */ 936static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 937{ 938 packed_refs->referrers++; 939} 940 941/* 942 * Decrease the reference count of *packed_refs. If it goes to zero, 943 * free *packed_refs and return true; otherwise return false. 944 */ 945static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 946{ 947if(!--packed_refs->referrers) { 948free_ref_entry(packed_refs->root); 949stat_validity_clear(&packed_refs->validity); 950free(packed_refs); 951return1; 952}else{ 953return0; 954} 955} 956 957static voidclear_packed_ref_cache(struct files_ref_store *refs) 958{ 959if(refs->packed) { 960struct packed_ref_cache *packed_refs = refs->packed; 961 962if(packed_refs->lock) 963die("internal error: packed-ref cache cleared while locked"); 964 refs->packed = NULL; 965release_packed_ref_cache(packed_refs); 966} 967} 968 969static voidclear_loose_ref_cache(struct files_ref_store *refs) 970{ 971if(refs->loose) { 972free_ref_entry(refs->loose); 973 refs->loose = NULL; 974} 975} 976 977/* 978 * Create a new submodule ref cache and add it to the internal 979 * set of caches. 980 */ 981static struct ref_store *files_ref_store_create(const char*submodule) 982{ 983struct files_ref_store *refs =xcalloc(1,sizeof(*refs)); 984struct ref_store *ref_store = (struct ref_store *)refs; 985 986base_ref_store_init(ref_store, &refs_be_files); 987 988 refs->submodule =xstrdup_or_null(submodule); 989 990return ref_store; 991} 992 993/* 994 * Die if refs is for a submodule (i.e., not for the main repository). 995 * caller is used in any necessary error messages. 996 */ 997static voidfiles_assert_main_repository(struct files_ref_store *refs, 998const char*caller) 999{1000if(refs->submodule)1001die("BUG:%scalled for a submodule", caller);1002}10031004/*1005 * Downcast ref_store to files_ref_store. Die if ref_store is not a1006 * files_ref_store. If submodule_allowed is not true, then also die if1007 * files_ref_store is for a submodule (i.e., not for the main1008 * repository). caller is used in any necessary error messages.1009 */1010static struct files_ref_store *files_downcast(1011struct ref_store *ref_store,int submodule_allowed,1012const char*caller)1013{1014struct files_ref_store *refs;10151016if(ref_store->be != &refs_be_files)1017die("BUG: ref_store is type\"%s\"not\"files\"in%s",1018 ref_store->be->name, caller);10191020 refs = (struct files_ref_store *)ref_store;10211022if(!submodule_allowed)1023files_assert_main_repository(refs, caller);10241025return refs;1026}10271028/* The length of a peeled reference line in packed-refs, including EOL: */1029#define PEELED_LINE_LENGTH 4210301031/*1032 * The packed-refs header line that we write out. Perhaps other1033 * traits will be added later. The trailing space is required.1034 */1035static const char PACKED_REFS_HEADER[] =1036"# pack-refs with: peeled fully-peeled\n";10371038/*1039 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1040 * Return a pointer to the refname within the line (null-terminated),1041 * or NULL if there was a problem.1042 */1043static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1044{1045const char*ref;10461047/*1048 * 42: the answer to everything.1049 *1050 * In this case, it happens to be the answer to1051 * 40 (length of sha1 hex representation)1052 * +1 (space in between hex and name)1053 * +1 (newline at the end of the line)1054 */1055if(line->len <=42)1056return NULL;10571058if(get_sha1_hex(line->buf, sha1) <0)1059return NULL;1060if(!isspace(line->buf[40]))1061return NULL;10621063 ref = line->buf +41;1064if(isspace(*ref))1065return NULL;10661067if(line->buf[line->len -1] !='\n')1068return NULL;1069 line->buf[--line->len] =0;10701071return ref;1072}10731074/*1075 * Read f, which is a packed-refs file, into dir.1076 *1077 * A comment line of the form "# pack-refs with: " may contain zero or1078 * more traits. We interpret the traits as follows:1079 *1080 * No traits:1081 *1082 * Probably no references are peeled. But if the file contains a1083 * peeled value for a reference, we will use it.1084 *1085 * peeled:1086 *1087 * References under "refs/tags/", if they *can* be peeled, *are*1088 * peeled in this file. References outside of "refs/tags/" are1089 * probably not peeled even if they could have been, but if we find1090 * a peeled value for such a reference we will use it.1091 *1092 * fully-peeled:1093 *1094 * All references in the file that can be peeled are peeled.1095 * Inversely (and this is more important), any references in the1096 * file for which no peeled value is recorded is not peelable. This1097 * trait should typically be written alongside "peeled" for1098 * compatibility with older clients, but we do not require it1099 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1100 */1101static voidread_packed_refs(FILE*f,struct ref_dir *dir)1102{1103struct ref_entry *last = NULL;1104struct strbuf line = STRBUF_INIT;1105enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11061107while(strbuf_getwholeline(&line, f,'\n') != EOF) {1108unsigned char sha1[20];1109const char*refname;1110const char*traits;11111112if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1113if(strstr(traits," fully-peeled "))1114 peeled = PEELED_FULLY;1115else if(strstr(traits," peeled "))1116 peeled = PEELED_TAGS;1117/* perhaps other traits later as well */1118continue;1119}11201121 refname =parse_ref_line(&line, sha1);1122if(refname) {1123int flag = REF_ISPACKED;11241125if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1126if(!refname_is_safe(refname))1127die("packed refname is dangerous:%s", refname);1128hashclr(sha1);1129 flag |= REF_BAD_NAME | REF_ISBROKEN;1130}1131 last =create_ref_entry(refname, sha1, flag,0);1132if(peeled == PEELED_FULLY ||1133(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1134 last->flag |= REF_KNOWS_PEELED;1135add_ref(dir, last);1136continue;1137}1138if(last &&1139 line.buf[0] =='^'&&1140 line.len == PEELED_LINE_LENGTH &&1141 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1142!get_sha1_hex(line.buf +1, sha1)) {1143hashcpy(last->u.value.peeled.hash, sha1);1144/*1145 * Regardless of what the file header said,1146 * we definitely know the value of *this*1147 * reference:1148 */1149 last->flag |= REF_KNOWS_PEELED;1150}1151}11521153strbuf_release(&line);1154}11551156/*1157 * Get the packed_ref_cache for the specified files_ref_store,1158 * creating it if necessary.1159 */1160static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1161{1162char*packed_refs_file;11631164if(refs->submodule)1165 packed_refs_file =git_pathdup_submodule(refs->submodule,1166"packed-refs");1167else1168 packed_refs_file =git_pathdup("packed-refs");11691170if(refs->packed &&1171!stat_validity_check(&refs->packed->validity, packed_refs_file))1172clear_packed_ref_cache(refs);11731174if(!refs->packed) {1175FILE*f;11761177 refs->packed =xcalloc(1,sizeof(*refs->packed));1178acquire_packed_ref_cache(refs->packed);1179 refs->packed->root =create_dir_entry(refs,"",0,0);1180 f =fopen(packed_refs_file,"r");1181if(f) {1182stat_validity_update(&refs->packed->validity,fileno(f));1183read_packed_refs(f,get_ref_dir(refs->packed->root));1184fclose(f);1185}1186}1187free(packed_refs_file);1188return refs->packed;1189}11901191static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1192{1193returnget_ref_dir(packed_ref_cache->root);1194}11951196static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1197{1198returnget_packed_ref_dir(get_packed_ref_cache(refs));1199}12001201/*1202 * Add a reference to the in-memory packed reference cache. This may1203 * only be called while the packed-refs file is locked (see1204 * lock_packed_refs()). To actually write the packed-refs file, call1205 * commit_packed_refs().1206 */1207static voidadd_packed_ref(struct files_ref_store *refs,1208const char*refname,const unsigned char*sha1)1209{1210struct packed_ref_cache *packed_ref_cache =get_packed_ref_cache(refs);12111212if(!packed_ref_cache->lock)1213die("internal error: packed refs not locked");1214add_ref(get_packed_ref_dir(packed_ref_cache),1215create_ref_entry(refname, sha1, REF_ISPACKED,1));1216}12171218/*1219 * Read the loose references from the namespace dirname into dir1220 * (without recursing). dirname must end with '/'. dir must be the1221 * directory entry corresponding to dirname.1222 */1223static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1224{1225struct files_ref_store *refs = dir->ref_store;1226DIR*d;1227struct dirent *de;1228int dirnamelen =strlen(dirname);1229struct strbuf refname;1230struct strbuf path = STRBUF_INIT;1231size_t path_baselen;1232int err =0;12331234if(refs->submodule)1235 err =strbuf_git_path_submodule(&path, refs->submodule,"%s", dirname);1236else1237strbuf_git_path(&path,"%s", dirname);1238 path_baselen = path.len;12391240if(err) {1241strbuf_release(&path);1242return;1243}12441245 d =opendir(path.buf);1246if(!d) {1247strbuf_release(&path);1248return;1249}12501251strbuf_init(&refname, dirnamelen +257);1252strbuf_add(&refname, dirname, dirnamelen);12531254while((de =readdir(d)) != NULL) {1255unsigned char sha1[20];1256struct stat st;1257int flag;12581259if(de->d_name[0] =='.')1260continue;1261if(ends_with(de->d_name,".lock"))1262continue;1263strbuf_addstr(&refname, de->d_name);1264strbuf_addstr(&path, de->d_name);1265if(stat(path.buf, &st) <0) {1266;/* silently ignore */1267}else if(S_ISDIR(st.st_mode)) {1268strbuf_addch(&refname,'/');1269add_entry_to_dir(dir,1270create_dir_entry(refs, refname.buf,1271 refname.len,1));1272}else{1273if(!resolve_ref_recursively(&refs->base,1274 refname.buf,1275 RESOLVE_REF_READING,1276 sha1, &flag)) {1277hashclr(sha1);1278 flag |= REF_ISBROKEN;1279}else if(is_null_sha1(sha1)) {1280/*1281 * It is so astronomically unlikely1282 * that NULL_SHA1 is the SHA-1 of an1283 * actual object that we consider its1284 * appearance in a loose reference1285 * file to be repo corruption1286 * (probably due to a software bug).1287 */1288 flag |= REF_ISBROKEN;1289}12901291if(check_refname_format(refname.buf,1292 REFNAME_ALLOW_ONELEVEL)) {1293if(!refname_is_safe(refname.buf))1294die("loose refname is dangerous:%s", refname.buf);1295hashclr(sha1);1296 flag |= REF_BAD_NAME | REF_ISBROKEN;1297}1298add_entry_to_dir(dir,1299create_ref_entry(refname.buf, sha1, flag,0));1300}1301strbuf_setlen(&refname, dirnamelen);1302strbuf_setlen(&path, path_baselen);1303}1304strbuf_release(&refname);1305strbuf_release(&path);1306closedir(d);1307}13081309static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1310{1311if(!refs->loose) {1312/*1313 * Mark the top-level directory complete because we1314 * are about to read the only subdirectory that can1315 * hold references:1316 */1317 refs->loose =create_dir_entry(refs,"",0,0);1318/*1319 * Create an incomplete entry for "refs/":1320 */1321add_entry_to_dir(get_ref_dir(refs->loose),1322create_dir_entry(refs,"refs/",5,1));1323}1324returnget_ref_dir(refs->loose);1325}13261327/*1328 * Return the ref_entry for the given refname from the packed1329 * references. If it does not exist, return NULL.1330 */1331static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1332const char*refname)1333{1334returnfind_ref(get_packed_refs(refs), refname);1335}13361337/*1338 * A loose ref file doesn't exist; check for a packed ref.1339 */1340static intresolve_packed_ref(struct files_ref_store *refs,1341const char*refname,1342unsigned char*sha1,unsigned int*flags)1343{1344struct ref_entry *entry;13451346/*1347 * The loose reference file does not exist; check for a packed1348 * reference.1349 */1350 entry =get_packed_ref(refs, refname);1351if(entry) {1352hashcpy(sha1, entry->u.value.oid.hash);1353*flags |= REF_ISPACKED;1354return0;1355}1356/* refname is not a packed reference. */1357return-1;1358}13591360static intfiles_read_raw_ref(struct ref_store *ref_store,1361const char*refname,unsigned char*sha1,1362struct strbuf *referent,unsigned int*type)1363{1364struct files_ref_store *refs =1365files_downcast(ref_store,1,"read_raw_ref");1366struct strbuf sb_contents = STRBUF_INIT;1367struct strbuf sb_path = STRBUF_INIT;1368const char*path;1369const char*buf;1370struct stat st;1371int fd;1372int ret = -1;1373int save_errno;1374int remaining_retries =3;13751376*type =0;1377strbuf_reset(&sb_path);13781379if(refs->submodule)1380strbuf_git_path_submodule(&sb_path, refs->submodule,"%s", refname);1381else1382strbuf_git_path(&sb_path,"%s", refname);13831384 path = sb_path.buf;13851386stat_ref:1387/*1388 * We might have to loop back here to avoid a race1389 * condition: first we lstat() the file, then we try1390 * to read it as a link or as a file. But if somebody1391 * changes the type of the file (file <-> directory1392 * <-> symlink) between the lstat() and reading, then1393 * we don't want to report that as an error but rather1394 * try again starting with the lstat().1395 *1396 * We'll keep a count of the retries, though, just to avoid1397 * any confusing situation sending us into an infinite loop.1398 */13991400if(remaining_retries-- <=0)1401goto out;14021403if(lstat(path, &st) <0) {1404if(errno != ENOENT)1405goto out;1406if(resolve_packed_ref(refs, refname, sha1, type)) {1407 errno = ENOENT;1408goto out;1409}1410 ret =0;1411goto out;1412}14131414/* Follow "normalized" - ie "refs/.." symlinks by hand */1415if(S_ISLNK(st.st_mode)) {1416strbuf_reset(&sb_contents);1417if(strbuf_readlink(&sb_contents, path,0) <0) {1418if(errno == ENOENT || errno == EINVAL)1419/* inconsistent with lstat; retry */1420goto stat_ref;1421else1422goto out;1423}1424if(starts_with(sb_contents.buf,"refs/") &&1425!check_refname_format(sb_contents.buf,0)) {1426strbuf_swap(&sb_contents, referent);1427*type |= REF_ISSYMREF;1428 ret =0;1429goto out;1430}1431/*1432 * It doesn't look like a refname; fall through to just1433 * treating it like a non-symlink, and reading whatever it1434 * points to.1435 */1436}14371438/* Is it a directory? */1439if(S_ISDIR(st.st_mode)) {1440/*1441 * Even though there is a directory where the loose1442 * ref is supposed to be, there could still be a1443 * packed ref:1444 */1445if(resolve_packed_ref(refs, refname, sha1, type)) {1446 errno = EISDIR;1447goto out;1448}1449 ret =0;1450goto out;1451}14521453/*1454 * Anything else, just open it and try to use it as1455 * a ref1456 */1457 fd =open(path, O_RDONLY);1458if(fd <0) {1459if(errno == ENOENT && !S_ISLNK(st.st_mode))1460/* inconsistent with lstat; retry */1461goto stat_ref;1462else1463goto out;1464}1465strbuf_reset(&sb_contents);1466if(strbuf_read(&sb_contents, fd,256) <0) {1467int save_errno = errno;1468close(fd);1469 errno = save_errno;1470goto out;1471}1472close(fd);1473strbuf_rtrim(&sb_contents);1474 buf = sb_contents.buf;1475if(starts_with(buf,"ref:")) {1476 buf +=4;1477while(isspace(*buf))1478 buf++;14791480strbuf_reset(referent);1481strbuf_addstr(referent, buf);1482*type |= REF_ISSYMREF;1483 ret =0;1484goto out;1485}14861487/*1488 * Please note that FETCH_HEAD has additional1489 * data after the sha.1490 */1491if(get_sha1_hex(buf, sha1) ||1492(buf[40] !='\0'&& !isspace(buf[40]))) {1493*type |= REF_ISBROKEN;1494 errno = EINVAL;1495goto out;1496}14971498 ret =0;14991500out:1501 save_errno = errno;1502strbuf_release(&sb_path);1503strbuf_release(&sb_contents);1504 errno = save_errno;1505return ret;1506}15071508static voidunlock_ref(struct ref_lock *lock)1509{1510/* Do not free lock->lk -- atexit() still looks at them */1511if(lock->lk)1512rollback_lock_file(lock->lk);1513free(lock->ref_name);1514free(lock);1515}15161517/*1518 * Lock refname, without following symrefs, and set *lock_p to point1519 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1520 * and type similarly to read_raw_ref().1521 *1522 * The caller must verify that refname is a "safe" reference name (in1523 * the sense of refname_is_safe()) before calling this function.1524 *1525 * If the reference doesn't already exist, verify that refname doesn't1526 * have a D/F conflict with any existing references. extras and skip1527 * are passed to verify_refname_available_dir() for this check.1528 *1529 * If mustexist is not set and the reference is not found or is1530 * broken, lock the reference anyway but clear sha1.1531 *1532 * Return 0 on success. On failure, write an error message to err and1533 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1534 *1535 * Implementation note: This function is basically1536 *1537 * lock reference1538 * read_raw_ref()1539 *1540 * but it includes a lot more code to1541 * - Deal with possible races with other processes1542 * - Avoid calling verify_refname_available_dir() when it can be1543 * avoided, namely if we were successfully able to read the ref1544 * - Generate informative error messages in the case of failure1545 */1546static intlock_raw_ref(struct files_ref_store *refs,1547const char*refname,int mustexist,1548const struct string_list *extras,1549const struct string_list *skip,1550struct ref_lock **lock_p,1551struct strbuf *referent,1552unsigned int*type,1553struct strbuf *err)1554{1555struct ref_lock *lock;1556struct strbuf ref_file = STRBUF_INIT;1557int attempts_remaining =3;1558int ret = TRANSACTION_GENERIC_ERROR;15591560assert(err);1561files_assert_main_repository(refs,"lock_raw_ref");15621563*type =0;15641565/* First lock the file so it can't change out from under us. */15661567*lock_p = lock =xcalloc(1,sizeof(*lock));15681569 lock->ref_name =xstrdup(refname);1570strbuf_git_path(&ref_file,"%s", refname);15711572retry:1573switch(safe_create_leading_directories(ref_file.buf)) {1574case SCLD_OK:1575break;/* success */1576case SCLD_EXISTS:1577/*1578 * Suppose refname is "refs/foo/bar". We just failed1579 * to create the containing directory, "refs/foo",1580 * because there was a non-directory in the way. This1581 * indicates a D/F conflict, probably because of1582 * another reference such as "refs/foo". There is no1583 * reason to expect this error to be transitory.1584 */1585if(verify_refname_available(refname, extras, skip, err)) {1586if(mustexist) {1587/*1588 * To the user the relevant error is1589 * that the "mustexist" reference is1590 * missing:1591 */1592strbuf_reset(err);1593strbuf_addf(err,"unable to resolve reference '%s'",1594 refname);1595}else{1596/*1597 * The error message set by1598 * verify_refname_available_dir() is OK.1599 */1600 ret = TRANSACTION_NAME_CONFLICT;1601}1602}else{1603/*1604 * The file that is in the way isn't a loose1605 * reference. Report it as a low-level1606 * failure.1607 */1608strbuf_addf(err,"unable to create lock file%s.lock; "1609"non-directory in the way",1610 ref_file.buf);1611}1612goto error_return;1613case SCLD_VANISHED:1614/* Maybe another process was tidying up. Try again. */1615if(--attempts_remaining >0)1616goto retry;1617/* fall through */1618default:1619strbuf_addf(err,"unable to create directory for%s",1620 ref_file.buf);1621goto error_return;1622}16231624if(!lock->lk)1625 lock->lk =xcalloc(1,sizeof(struct lock_file));16261627if(hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) <0) {1628if(errno == ENOENT && --attempts_remaining >0) {1629/*1630 * Maybe somebody just deleted one of the1631 * directories leading to ref_file. Try1632 * again:1633 */1634goto retry;1635}else{1636unable_to_lock_message(ref_file.buf, errno, err);1637goto error_return;1638}1639}16401641/*1642 * Now we hold the lock and can read the reference without1643 * fear that its value will change.1644 */16451646if(files_read_raw_ref(&refs->base, refname,1647 lock->old_oid.hash, referent, type)) {1648if(errno == ENOENT) {1649if(mustexist) {1650/* Garden variety missing reference. */1651strbuf_addf(err,"unable to resolve reference '%s'",1652 refname);1653goto error_return;1654}else{1655/*1656 * Reference is missing, but that's OK. We1657 * know that there is not a conflict with1658 * another loose reference because1659 * (supposing that we are trying to lock1660 * reference "refs/foo/bar"):1661 *1662 * - We were successfully able to create1663 * the lockfile refs/foo/bar.lock, so we1664 * know there cannot be a loose reference1665 * named "refs/foo".1666 *1667 * - We got ENOENT and not EISDIR, so we1668 * know that there cannot be a loose1669 * reference named "refs/foo/bar/baz".1670 */1671}1672}else if(errno == EISDIR) {1673/*1674 * There is a directory in the way. It might have1675 * contained references that have been deleted. If1676 * we don't require that the reference already1677 * exists, try to remove the directory so that it1678 * doesn't cause trouble when we want to rename the1679 * lockfile into place later.1680 */1681if(mustexist) {1682/* Garden variety missing reference. */1683strbuf_addf(err,"unable to resolve reference '%s'",1684 refname);1685goto error_return;1686}else if(remove_dir_recursively(&ref_file,1687 REMOVE_DIR_EMPTY_ONLY)) {1688if(verify_refname_available_dir(1689 refname, extras, skip,1690get_loose_refs(refs),1691 err)) {1692/*1693 * The error message set by1694 * verify_refname_available() is OK.1695 */1696 ret = TRANSACTION_NAME_CONFLICT;1697goto error_return;1698}else{1699/*1700 * We can't delete the directory,1701 * but we also don't know of any1702 * references that it should1703 * contain.1704 */1705strbuf_addf(err,"there is a non-empty directory '%s' "1706"blocking reference '%s'",1707 ref_file.buf, refname);1708goto error_return;1709}1710}1711}else if(errno == EINVAL && (*type & REF_ISBROKEN)) {1712strbuf_addf(err,"unable to resolve reference '%s': "1713"reference broken", refname);1714goto error_return;1715}else{1716strbuf_addf(err,"unable to resolve reference '%s':%s",1717 refname,strerror(errno));1718goto error_return;1719}17201721/*1722 * If the ref did not exist and we are creating it,1723 * make sure there is no existing packed ref whose1724 * name begins with our refname, nor a packed ref1725 * whose name is a proper prefix of our refname.1726 */1727if(verify_refname_available_dir(1728 refname, extras, skip,1729get_packed_refs(refs),1730 err)) {1731goto error_return;1732}1733}17341735 ret =0;1736goto out;17371738error_return:1739unlock_ref(lock);1740*lock_p = NULL;17411742out:1743strbuf_release(&ref_file);1744return ret;1745}17461747/*1748 * Peel the entry (if possible) and return its new peel_status. If1749 * repeel is true, re-peel the entry even if there is an old peeled1750 * value that is already stored in it.1751 *1752 * It is OK to call this function with a packed reference entry that1753 * might be stale and might even refer to an object that has since1754 * been garbage-collected. In such a case, if the entry has1755 * REF_KNOWS_PEELED then leave the status unchanged and return1756 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1757 */1758static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1759{1760enum peel_status status;17611762if(entry->flag & REF_KNOWS_PEELED) {1763if(repeel) {1764 entry->flag &= ~REF_KNOWS_PEELED;1765oidclr(&entry->u.value.peeled);1766}else{1767returnis_null_oid(&entry->u.value.peeled) ?1768 PEEL_NON_TAG : PEEL_PEELED;1769}1770}1771if(entry->flag & REF_ISBROKEN)1772return PEEL_BROKEN;1773if(entry->flag & REF_ISSYMREF)1774return PEEL_IS_SYMREF;17751776 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1777if(status == PEEL_PEELED || status == PEEL_NON_TAG)1778 entry->flag |= REF_KNOWS_PEELED;1779return status;1780}17811782static intfiles_peel_ref(struct ref_store *ref_store,1783const char*refname,unsigned char*sha1)1784{1785struct files_ref_store *refs =files_downcast(ref_store,0,"peel_ref");1786int flag;1787unsigned char base[20];17881789if(current_ref_iter && current_ref_iter->refname == refname) {1790struct object_id peeled;17911792if(ref_iterator_peel(current_ref_iter, &peeled))1793return-1;1794hashcpy(sha1, peeled.hash);1795return0;1796}17971798if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1799return-1;18001801/*1802 * If the reference is packed, read its ref_entry from the1803 * cache in the hope that we already know its peeled value.1804 * We only try this optimization on packed references because1805 * (a) forcing the filling of the loose reference cache could1806 * be expensive and (b) loose references anyway usually do not1807 * have REF_KNOWS_PEELED.1808 */1809if(flag & REF_ISPACKED) {1810struct ref_entry *r =get_packed_ref(refs, refname);1811if(r) {1812if(peel_entry(r,0))1813return-1;1814hashcpy(sha1, r->u.value.peeled.hash);1815return0;1816}1817}18181819returnpeel_object(base, sha1);1820}18211822struct files_ref_iterator {1823struct ref_iterator base;18241825struct packed_ref_cache *packed_ref_cache;1826struct ref_iterator *iter0;1827unsigned int flags;1828};18291830static intfiles_ref_iterator_advance(struct ref_iterator *ref_iterator)1831{1832struct files_ref_iterator *iter =1833(struct files_ref_iterator *)ref_iterator;1834int ok;18351836while((ok =ref_iterator_advance(iter->iter0)) == ITER_OK) {1837if(iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&1838ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1839continue;18401841if(!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1842!ref_resolves_to_object(iter->iter0->refname,1843 iter->iter0->oid,1844 iter->iter0->flags))1845continue;18461847 iter->base.refname = iter->iter0->refname;1848 iter->base.oid = iter->iter0->oid;1849 iter->base.flags = iter->iter0->flags;1850return ITER_OK;1851}18521853 iter->iter0 = NULL;1854if(ref_iterator_abort(ref_iterator) != ITER_DONE)1855 ok = ITER_ERROR;18561857return ok;1858}18591860static intfiles_ref_iterator_peel(struct ref_iterator *ref_iterator,1861struct object_id *peeled)1862{1863struct files_ref_iterator *iter =1864(struct files_ref_iterator *)ref_iterator;18651866returnref_iterator_peel(iter->iter0, peeled);1867}18681869static intfiles_ref_iterator_abort(struct ref_iterator *ref_iterator)1870{1871struct files_ref_iterator *iter =1872(struct files_ref_iterator *)ref_iterator;1873int ok = ITER_DONE;18741875if(iter->iter0)1876 ok =ref_iterator_abort(iter->iter0);18771878release_packed_ref_cache(iter->packed_ref_cache);1879base_ref_iterator_free(ref_iterator);1880return ok;1881}18821883static struct ref_iterator_vtable files_ref_iterator_vtable = {1884 files_ref_iterator_advance,1885 files_ref_iterator_peel,1886 files_ref_iterator_abort1887};18881889static struct ref_iterator *files_ref_iterator_begin(1890struct ref_store *ref_store,1891const char*prefix,unsigned int flags)1892{1893struct files_ref_store *refs =1894files_downcast(ref_store,1,"ref_iterator_begin");1895struct ref_dir *loose_dir, *packed_dir;1896struct ref_iterator *loose_iter, *packed_iter;1897struct files_ref_iterator *iter;1898struct ref_iterator *ref_iterator;18991900if(!refs)1901returnempty_ref_iterator_begin();19021903if(ref_paranoia <0)1904 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1905if(ref_paranoia)1906 flags |= DO_FOR_EACH_INCLUDE_BROKEN;19071908 iter =xcalloc(1,sizeof(*iter));1909 ref_iterator = &iter->base;1910base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);19111912/*1913 * We must make sure that all loose refs are read before1914 * accessing the packed-refs file; this avoids a race1915 * condition if loose refs are migrated to the packed-refs1916 * file by a simultaneous process, but our in-memory view is1917 * from before the migration. We ensure this as follows:1918 * First, we call prime_ref_dir(), which pre-reads the loose1919 * references for the subtree into the cache. (If they've1920 * already been read, that's OK; we only need to guarantee1921 * that they're read before the packed refs, not *how much*1922 * before.) After that, we call get_packed_ref_cache(), which1923 * internally checks whether the packed-ref cache is up to1924 * date with what is on disk, and re-reads it if not.1925 */19261927 loose_dir =get_loose_refs(refs);19281929if(prefix && *prefix)1930 loose_dir =find_containing_dir(loose_dir, prefix,0);19311932if(loose_dir) {1933prime_ref_dir(loose_dir);1934 loose_iter =cache_ref_iterator_begin(loose_dir);1935}else{1936/* There's nothing to iterate over. */1937 loose_iter =empty_ref_iterator_begin();1938}19391940 iter->packed_ref_cache =get_packed_ref_cache(refs);1941acquire_packed_ref_cache(iter->packed_ref_cache);1942 packed_dir =get_packed_ref_dir(iter->packed_ref_cache);19431944if(prefix && *prefix)1945 packed_dir =find_containing_dir(packed_dir, prefix,0);19461947if(packed_dir) {1948 packed_iter =cache_ref_iterator_begin(packed_dir);1949}else{1950/* There's nothing to iterate over. */1951 packed_iter =empty_ref_iterator_begin();1952}19531954 iter->iter0 =overlay_ref_iterator_begin(loose_iter, packed_iter);1955 iter->flags = flags;19561957return ref_iterator;1958}19591960/*1961 * Verify that the reference locked by lock has the value old_sha1.1962 * Fail if the reference doesn't exist and mustexist is set. Return 01963 * on success. On error, write an error message to err, set errno, and1964 * return a negative value.1965 */1966static intverify_lock(struct ref_lock *lock,1967const unsigned char*old_sha1,int mustexist,1968struct strbuf *err)1969{1970assert(err);19711972if(read_ref_full(lock->ref_name,1973 mustexist ? RESOLVE_REF_READING :0,1974 lock->old_oid.hash, NULL)) {1975if(old_sha1) {1976int save_errno = errno;1977strbuf_addf(err,"can't verify ref '%s'", lock->ref_name);1978 errno = save_errno;1979return-1;1980}else{1981oidclr(&lock->old_oid);1982return0;1983}1984}1985if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {1986strbuf_addf(err,"ref '%s' is at%sbut expected%s",1987 lock->ref_name,1988oid_to_hex(&lock->old_oid),1989sha1_to_hex(old_sha1));1990 errno = EBUSY;1991return-1;1992}1993return0;1994}19951996static intremove_empty_directories(struct strbuf *path)1997{1998/*1999 * we want to create a file but there is a directory there;2000 * if that is an empty directory (or a directory that contains2001 * only empty directories), remove them.2002 */2003returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);2004}20052006static intcreate_reflock(const char*path,void*cb)2007{2008struct lock_file *lk = cb;20092010returnhold_lock_file_for_update(lk, path, LOCK_NO_DEREF) <0? -1:0;2011}20122013/*2014 * Locks a ref returning the lock on success and NULL on failure.2015 * On failure errno is set to something meaningful.2016 */2017static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,2018const char*refname,2019const unsigned char*old_sha1,2020const struct string_list *extras,2021const struct string_list *skip,2022unsigned int flags,int*type,2023struct strbuf *err)2024{2025struct strbuf ref_file = STRBUF_INIT;2026struct ref_lock *lock;2027int last_errno =0;2028int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2029int resolve_flags = RESOLVE_REF_NO_RECURSE;2030int resolved;20312032files_assert_main_repository(refs,"lock_ref_sha1_basic");2033assert(err);20342035 lock =xcalloc(1,sizeof(struct ref_lock));20362037if(mustexist)2038 resolve_flags |= RESOLVE_REF_READING;2039if(flags & REF_DELETING)2040 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20412042strbuf_git_path(&ref_file,"%s", refname);2043 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2044 lock->old_oid.hash, type);2045if(!resolved && errno == EISDIR) {2046/*2047 * we are trying to lock foo but we used to2048 * have foo/bar which now does not exist;2049 * it is normal for the empty directory 'foo'2050 * to remain.2051 */2052if(remove_empty_directories(&ref_file)) {2053 last_errno = errno;2054if(!verify_refname_available_dir(2055 refname, extras, skip,2056get_loose_refs(refs), err))2057strbuf_addf(err,"there are still refs under '%s'",2058 refname);2059goto error_return;2060}2061 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2062 lock->old_oid.hash, type);2063}2064if(!resolved) {2065 last_errno = errno;2066if(last_errno != ENOTDIR ||2067!verify_refname_available_dir(2068 refname, extras, skip,2069get_loose_refs(refs), err))2070strbuf_addf(err,"unable to resolve reference '%s':%s",2071 refname,strerror(last_errno));20722073goto error_return;2074}20752076/*2077 * If the ref did not exist and we are creating it, make sure2078 * there is no existing packed ref whose name begins with our2079 * refname, nor a packed ref whose name is a proper prefix of2080 * our refname.2081 */2082if(is_null_oid(&lock->old_oid) &&2083verify_refname_available_dir(refname, extras, skip,2084get_packed_refs(refs),2085 err)) {2086 last_errno = ENOTDIR;2087goto error_return;2088}20892090 lock->lk =xcalloc(1,sizeof(struct lock_file));20912092 lock->ref_name =xstrdup(refname);20932094if(raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {2095 last_errno = errno;2096unable_to_lock_message(ref_file.buf, errno, err);2097goto error_return;2098}20992100if(verify_lock(lock, old_sha1, mustexist, err)) {2101 last_errno = errno;2102goto error_return;2103}2104goto out;21052106 error_return:2107unlock_ref(lock);2108 lock = NULL;21092110 out:2111strbuf_release(&ref_file);2112 errno = last_errno;2113return lock;2114}21152116/*2117 * Write an entry to the packed-refs file for the specified refname.2118 * If peeled is non-NULL, write it as the entry's peeled value.2119 */2120static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2121unsigned char*peeled)2122{2123fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2124if(peeled)2125fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2126}21272128/*2129 * An each_ref_entry_fn that writes the entry to a packed-refs file.2130 */2131static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2132{2133enum peel_status peel_status =peel_entry(entry,0);21342135if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2136error("internal error:%sis not a valid packed reference!",2137 entry->name);2138write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2139 peel_status == PEEL_PEELED ?2140 entry->u.value.peeled.hash : NULL);2141return0;2142}21432144/*2145 * Lock the packed-refs file for writing. Flags is passed to2146 * hold_lock_file_for_update(). Return 0 on success. On errors, set2147 * errno appropriately and return a nonzero value.2148 */2149static intlock_packed_refs(struct files_ref_store *refs,int flags)2150{2151static int timeout_configured =0;2152static int timeout_value =1000;2153struct packed_ref_cache *packed_ref_cache;21542155files_assert_main_repository(refs,"lock_packed_refs");21562157if(!timeout_configured) {2158git_config_get_int("core.packedrefstimeout", &timeout_value);2159 timeout_configured =1;2160}21612162if(hold_lock_file_for_update_timeout(2163&packlock,git_path("packed-refs"),2164 flags, timeout_value) <0)2165return-1;2166/*2167 * Get the current packed-refs while holding the lock. If the2168 * packed-refs file has been modified since we last read it,2169 * this will automatically invalidate the cache and re-read2170 * the packed-refs file.2171 */2172 packed_ref_cache =get_packed_ref_cache(refs);2173 packed_ref_cache->lock = &packlock;2174/* Increment the reference count to prevent it from being freed: */2175acquire_packed_ref_cache(packed_ref_cache);2176return0;2177}21782179/*2180 * Write the current version of the packed refs cache from memory to2181 * disk. The packed-refs file must already be locked for writing (see2182 * lock_packed_refs()). Return zero on success. On errors, set errno2183 * and return a nonzero value2184 */2185static intcommit_packed_refs(struct files_ref_store *refs)2186{2187struct packed_ref_cache *packed_ref_cache =2188get_packed_ref_cache(refs);2189int error =0;2190int save_errno =0;2191FILE*out;21922193files_assert_main_repository(refs,"commit_packed_refs");21942195if(!packed_ref_cache->lock)2196die("internal error: packed-refs not locked");21972198 out =fdopen_lock_file(packed_ref_cache->lock,"w");2199if(!out)2200die_errno("unable to fdopen packed-refs descriptor");22012202fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2203do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),22040, write_packed_entry_fn, out);22052206if(commit_lock_file(packed_ref_cache->lock)) {2207 save_errno = errno;2208 error = -1;2209}2210 packed_ref_cache->lock = NULL;2211release_packed_ref_cache(packed_ref_cache);2212 errno = save_errno;2213return error;2214}22152216/*2217 * Rollback the lockfile for the packed-refs file, and discard the2218 * in-memory packed reference cache. (The packed-refs file will be2219 * read anew if it is needed again after this function is called.)2220 */2221static voidrollback_packed_refs(struct files_ref_store *refs)2222{2223struct packed_ref_cache *packed_ref_cache =2224get_packed_ref_cache(refs);22252226files_assert_main_repository(refs,"rollback_packed_refs");22272228if(!packed_ref_cache->lock)2229die("internal error: packed-refs not locked");2230rollback_lock_file(packed_ref_cache->lock);2231 packed_ref_cache->lock = NULL;2232release_packed_ref_cache(packed_ref_cache);2233clear_packed_ref_cache(refs);2234}22352236struct ref_to_prune {2237struct ref_to_prune *next;2238unsigned char sha1[20];2239char name[FLEX_ARRAY];2240};22412242struct pack_refs_cb_data {2243unsigned int flags;2244struct ref_dir *packed_refs;2245struct ref_to_prune *ref_to_prune;2246};22472248/*2249 * An each_ref_entry_fn that is run over loose references only. If2250 * the loose reference can be packed, add an entry in the packed ref2251 * cache. If the reference should be pruned, also add it to2252 * ref_to_prune in the pack_refs_cb_data.2253 */2254static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2255{2256struct pack_refs_cb_data *cb = cb_data;2257enum peel_status peel_status;2258struct ref_entry *packed_entry;2259int is_tag_ref =starts_with(entry->name,"refs/tags/");22602261/* Do not pack per-worktree refs: */2262if(ref_type(entry->name) != REF_TYPE_NORMAL)2263return0;22642265/* ALWAYS pack tags */2266if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2267return0;22682269/* Do not pack symbolic or broken refs: */2270if((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2271return0;22722273/* Add a packed ref cache entry equivalent to the loose entry. */2274 peel_status =peel_entry(entry,1);2275if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2276die("internal error peeling reference%s(%s)",2277 entry->name,oid_to_hex(&entry->u.value.oid));2278 packed_entry =find_ref(cb->packed_refs, entry->name);2279if(packed_entry) {2280/* Overwrite existing packed entry with info from loose entry */2281 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2282oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2283}else{2284 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2285 REF_ISPACKED | REF_KNOWS_PEELED,0);2286add_ref(cb->packed_refs, packed_entry);2287}2288oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);22892290/* Schedule the loose reference for pruning if requested. */2291if((cb->flags & PACK_REFS_PRUNE)) {2292struct ref_to_prune *n;2293FLEX_ALLOC_STR(n, name, entry->name);2294hashcpy(n->sha1, entry->u.value.oid.hash);2295 n->next = cb->ref_to_prune;2296 cb->ref_to_prune = n;2297}2298return0;2299}23002301enum{2302 REMOVE_EMPTY_PARENTS_REF =0x01,2303 REMOVE_EMPTY_PARENTS_REFLOG =0x022304};23052306/*2307 * Remove empty parent directories associated with the specified2308 * reference and/or its reflog, but spare [logs/]refs/ and immediate2309 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or2310 * REMOVE_EMPTY_PARENTS_REFLOG.2311 */2312static voidtry_remove_empty_parents(const char*refname,unsigned int flags)2313{2314struct strbuf buf = STRBUF_INIT;2315char*p, *q;2316int i;23172318strbuf_addstr(&buf, refname);2319 p = buf.buf;2320for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2321while(*p && *p !='/')2322 p++;2323/* tolerate duplicate slashes; see check_refname_format() */2324while(*p =='/')2325 p++;2326}2327 q = buf.buf + buf.len;2328while(flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {2329while(q > p && *q !='/')2330 q--;2331while(q > p && *(q-1) =='/')2332 q--;2333if(q == p)2334break;2335strbuf_setlen(&buf, q - buf.buf);2336if((flags & REMOVE_EMPTY_PARENTS_REF) &&2337rmdir(git_path("%s", buf.buf)))2338 flags &= ~REMOVE_EMPTY_PARENTS_REF;2339if((flags & REMOVE_EMPTY_PARENTS_REFLOG) &&2340rmdir(git_path("logs/%s", buf.buf)))2341 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;2342}2343strbuf_release(&buf);2344}23452346/* make sure nobody touched the ref, and unlink */2347static voidprune_ref(struct ref_to_prune *r)2348{2349struct ref_transaction *transaction;2350struct strbuf err = STRBUF_INIT;23512352if(check_refname_format(r->name,0))2353return;23542355 transaction =ref_transaction_begin(&err);2356if(!transaction ||2357ref_transaction_delete(transaction, r->name, r->sha1,2358 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2359ref_transaction_commit(transaction, &err)) {2360ref_transaction_free(transaction);2361error("%s", err.buf);2362strbuf_release(&err);2363return;2364}2365ref_transaction_free(transaction);2366strbuf_release(&err);2367}23682369static voidprune_refs(struct ref_to_prune *r)2370{2371while(r) {2372prune_ref(r);2373 r = r->next;2374}2375}23762377static intfiles_pack_refs(struct ref_store *ref_store,unsigned int flags)2378{2379struct files_ref_store *refs =2380files_downcast(ref_store,0,"pack_refs");2381struct pack_refs_cb_data cbdata;23822383memset(&cbdata,0,sizeof(cbdata));2384 cbdata.flags = flags;23852386lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2387 cbdata.packed_refs =get_packed_refs(refs);23882389do_for_each_entry_in_dir(get_loose_refs(refs),0,2390 pack_if_possible_fn, &cbdata);23912392if(commit_packed_refs(refs))2393die_errno("unable to overwrite old ref-pack file");23942395prune_refs(cbdata.ref_to_prune);2396return0;2397}23982399/*2400 * Rewrite the packed-refs file, omitting any refs listed in2401 * 'refnames'. On error, leave packed-refs unchanged, write an error2402 * message to 'err', and return a nonzero value.2403 *2404 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2405 */2406static intrepack_without_refs(struct files_ref_store *refs,2407struct string_list *refnames,struct strbuf *err)2408{2409struct ref_dir *packed;2410struct string_list_item *refname;2411int ret, needs_repacking =0, removed =0;24122413files_assert_main_repository(refs,"repack_without_refs");2414assert(err);24152416/* Look for a packed ref */2417for_each_string_list_item(refname, refnames) {2418if(get_packed_ref(refs, refname->string)) {2419 needs_repacking =1;2420break;2421}2422}24232424/* Avoid locking if we have nothing to do */2425if(!needs_repacking)2426return0;/* no refname exists in packed refs */24272428if(lock_packed_refs(refs,0)) {2429unable_to_lock_message(git_path("packed-refs"), errno, err);2430return-1;2431}2432 packed =get_packed_refs(refs);24332434/* Remove refnames from the cache */2435for_each_string_list_item(refname, refnames)2436if(remove_entry(packed, refname->string) != -1)2437 removed =1;2438if(!removed) {2439/*2440 * All packed entries disappeared while we were2441 * acquiring the lock.2442 */2443rollback_packed_refs(refs);2444return0;2445}24462447/* Write what remains */2448 ret =commit_packed_refs(refs);2449if(ret)2450strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2451strerror(errno));2452return ret;2453}24542455static intfiles_delete_refs(struct ref_store *ref_store,2456struct string_list *refnames,unsigned int flags)2457{2458struct files_ref_store *refs =2459files_downcast(ref_store,0,"delete_refs");2460struct strbuf err = STRBUF_INIT;2461int i, result =0;24622463if(!refnames->nr)2464return0;24652466 result =repack_without_refs(refs, refnames, &err);2467if(result) {2468/*2469 * If we failed to rewrite the packed-refs file, then2470 * it is unsafe to try to remove loose refs, because2471 * doing so might expose an obsolete packed value for2472 * a reference that might even point at an object that2473 * has been garbage collected.2474 */2475if(refnames->nr ==1)2476error(_("could not delete reference%s:%s"),2477 refnames->items[0].string, err.buf);2478else2479error(_("could not delete references:%s"), err.buf);24802481goto out;2482}24832484for(i =0; i < refnames->nr; i++) {2485const char*refname = refnames->items[i].string;24862487if(delete_ref(NULL, refname, NULL, flags))2488 result |=error(_("could not remove reference%s"), refname);2489}24902491out:2492strbuf_release(&err);2493return result;2494}24952496/*2497 * People using contrib's git-new-workdir have .git/logs/refs ->2498 * /some/other/path/.git/logs/refs, and that may live on another device.2499 *2500 * IOW, to avoid cross device rename errors, the temporary renamed log must2501 * live into logs/refs.2502 */2503#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"25042505static intrename_tmp_log_callback(const char*path,void*cb)2506{2507int*true_errno = cb;25082509if(rename(git_path(TMP_RENAMED_LOG), path)) {2510/*2511 * rename(a, b) when b is an existing directory ought2512 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.2513 * Sheesh. Record the true errno for error reporting,2514 * but report EISDIR to raceproof_create_file() so2515 * that it knows to retry.2516 */2517*true_errno = errno;2518if(errno == ENOTDIR)2519 errno = EISDIR;2520return-1;2521}else{2522return0;2523}2524}25252526static intrename_tmp_log(const char*newrefname)2527{2528char*path =git_pathdup("logs/%s", newrefname);2529int ret, true_errno;25302531 ret =raceproof_create_file(path, rename_tmp_log_callback, &true_errno);2532if(ret) {2533if(errno == EISDIR)2534error("directory not empty:%s", path);2535else2536error("unable to move logfile%sto%s:%s",2537git_path(TMP_RENAMED_LOG), path,2538strerror(true_errno));2539}25402541free(path);2542return ret;2543}25442545static intfiles_verify_refname_available(struct ref_store *ref_store,2546const char*newname,2547const struct string_list *extras,2548const struct string_list *skip,2549struct strbuf *err)2550{2551struct files_ref_store *refs =2552files_downcast(ref_store,1,"verify_refname_available");2553struct ref_dir *packed_refs =get_packed_refs(refs);2554struct ref_dir *loose_refs =get_loose_refs(refs);25552556if(verify_refname_available_dir(newname, extras, skip,2557 packed_refs, err) ||2558verify_refname_available_dir(newname, extras, skip,2559 loose_refs, err))2560return-1;25612562return0;2563}25642565static intwrite_ref_to_lockfile(struct ref_lock *lock,2566const unsigned char*sha1,struct strbuf *err);2567static intcommit_ref_update(struct files_ref_store *refs,2568struct ref_lock *lock,2569const unsigned char*sha1,const char*logmsg,2570struct strbuf *err);25712572static intfiles_rename_ref(struct ref_store *ref_store,2573const char*oldrefname,const char*newrefname,2574const char*logmsg)2575{2576struct files_ref_store *refs =2577files_downcast(ref_store,0,"rename_ref");2578unsigned char sha1[20], orig_sha1[20];2579int flag =0, logmoved =0;2580struct ref_lock *lock;2581struct stat loginfo;2582int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2583struct strbuf err = STRBUF_INIT;25842585if(log &&S_ISLNK(loginfo.st_mode))2586returnerror("reflog for%sis a symlink", oldrefname);25872588if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2589 orig_sha1, &flag))2590returnerror("refname%snot found", oldrefname);25912592if(flag & REF_ISSYMREF)2593returnerror("refname%sis a symbolic ref, renaming it is not supported",2594 oldrefname);2595if(!rename_ref_available(oldrefname, newrefname))2596return1;25972598if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2599returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2600 oldrefname,strerror(errno));26012602if(delete_ref(logmsg, oldrefname, orig_sha1, REF_NODEREF)) {2603error("unable to delete old%s", oldrefname);2604goto rollback;2605}26062607/*2608 * Since we are doing a shallow lookup, sha1 is not the2609 * correct value to pass to delete_ref as old_sha1. But that2610 * doesn't matter, because an old_sha1 check wouldn't add to2611 * the safety anyway; we want to delete the reference whatever2612 * its current value.2613 */2614if(!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2615 sha1, NULL) &&2616delete_ref(NULL, newrefname, NULL, REF_NODEREF)) {2617if(errno == EISDIR) {2618struct strbuf path = STRBUF_INIT;2619int result;26202621strbuf_git_path(&path,"%s", newrefname);2622 result =remove_empty_directories(&path);2623strbuf_release(&path);26242625if(result) {2626error("Directory not empty:%s", newrefname);2627goto rollback;2628}2629}else{2630error("unable to delete existing%s", newrefname);2631goto rollback;2632}2633}26342635if(log &&rename_tmp_log(newrefname))2636goto rollback;26372638 logmoved = log;26392640 lock =lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,2641 REF_NODEREF, NULL, &err);2642if(!lock) {2643error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2644strbuf_release(&err);2645goto rollback;2646}2647hashcpy(lock->old_oid.hash, orig_sha1);26482649if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2650commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {2651error("unable to write current sha1 into%s:%s", newrefname, err.buf);2652strbuf_release(&err);2653goto rollback;2654}26552656return0;26572658 rollback:2659 lock =lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,2660 REF_NODEREF, NULL, &err);2661if(!lock) {2662error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2663strbuf_release(&err);2664goto rollbacklog;2665}26662667 flag = log_all_ref_updates;2668 log_all_ref_updates = LOG_REFS_NONE;2669if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2670commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {2671error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2672strbuf_release(&err);2673}2674 log_all_ref_updates = flag;26752676 rollbacklog:2677if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2678error("unable to restore logfile%sfrom%s:%s",2679 oldrefname, newrefname,strerror(errno));2680if(!logmoved && log &&2681rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2682error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2683 oldrefname,strerror(errno));26842685return1;2686}26872688static intclose_ref(struct ref_lock *lock)2689{2690if(close_lock_file(lock->lk))2691return-1;2692return0;2693}26942695static intcommit_ref(struct ref_lock *lock)2696{2697char*path =get_locked_file_path(lock->lk);2698struct stat st;26992700if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2701/*2702 * There is a directory at the path we want to rename2703 * the lockfile to. Hopefully it is empty; try to2704 * delete it.2705 */2706size_t len =strlen(path);2707struct strbuf sb_path = STRBUF_INIT;27082709strbuf_attach(&sb_path, path, len, len);27102711/*2712 * If this fails, commit_lock_file() will also fail2713 * and will report the problem.2714 */2715remove_empty_directories(&sb_path);2716strbuf_release(&sb_path);2717}else{2718free(path);2719}27202721if(commit_lock_file(lock->lk))2722return-1;2723return0;2724}27252726static intopen_or_create_logfile(const char*path,void*cb)2727{2728int*fd = cb;27292730*fd =open(path, O_APPEND | O_WRONLY | O_CREAT,0666);2731return(*fd <0) ? -1:0;2732}27332734/*2735 * Create a reflog for a ref. If force_create = 0, only create the2736 * reflog for certain refs (those for which should_autocreate_reflog2737 * returns non-zero). Otherwise, create it regardless of the reference2738 * name. If the logfile already existed or was created, return 0 and2739 * set *logfd to the file descriptor opened for appending to the file.2740 * If no logfile exists and we decided not to create one, return 0 and2741 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and2742 * return -1.2743 */2744static intlog_ref_setup(const char*refname,int force_create,2745int*logfd,struct strbuf *err)2746{2747char*logfile =git_pathdup("logs/%s", refname);27482749if(force_create ||should_autocreate_reflog(refname)) {2750if(raceproof_create_file(logfile, open_or_create_logfile, logfd)) {2751if(errno == ENOENT)2752strbuf_addf(err,"unable to create directory for '%s': "2753"%s", logfile,strerror(errno));2754else if(errno == EISDIR)2755strbuf_addf(err,"there are still logs under '%s'",2756 logfile);2757else2758strbuf_addf(err,"unable to append to '%s':%s",2759 logfile,strerror(errno));27602761goto error;2762}2763}else{2764*logfd =open(logfile, O_APPEND | O_WRONLY,0666);2765if(*logfd <0) {2766if(errno == ENOENT || errno == EISDIR) {2767/*2768 * The logfile doesn't already exist,2769 * but that is not an error; it only2770 * means that we won't write log2771 * entries to it.2772 */2773;2774}else{2775strbuf_addf(err,"unable to append to '%s':%s",2776 logfile,strerror(errno));2777goto error;2778}2779}2780}27812782if(*logfd >=0)2783adjust_shared_perm(logfile);27842785free(logfile);2786return0;27872788error:2789free(logfile);2790return-1;2791}27922793static intfiles_create_reflog(struct ref_store *ref_store,2794const char*refname,int force_create,2795struct strbuf *err)2796{2797int fd;27982799/* Check validity (but we don't need the result): */2800files_downcast(ref_store,0,"create_reflog");28012802if(log_ref_setup(refname, force_create, &fd, err))2803return-1;28042805if(fd >=0)2806close(fd);28072808return0;2809}28102811static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2812const unsigned char*new_sha1,2813const char*committer,const char*msg)2814{2815int msglen, written;2816unsigned maxlen, len;2817char*logrec;28182819 msglen = msg ?strlen(msg) :0;2820 maxlen =strlen(committer) + msglen +100;2821 logrec =xmalloc(maxlen);2822 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2823sha1_to_hex(old_sha1),2824sha1_to_hex(new_sha1),2825 committer);2826if(msglen)2827 len +=copy_reflog_msg(logrec + len -1, msg) -1;28282829 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2830free(logrec);2831if(written != len)2832return-1;28332834return0;2835}28362837static intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1,2838const unsigned char*new_sha1,const char*msg,2839int flags,struct strbuf *err)2840{2841int logfd, result;28422843if(log_all_ref_updates == LOG_REFS_UNSET)2844 log_all_ref_updates =is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;28452846 result =log_ref_setup(refname, flags & REF_FORCE_CREATE_REFLOG,2847&logfd, err);28482849if(result)2850return result;28512852if(logfd <0)2853return0;2854 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2855git_committer_info(0), msg);2856if(result) {2857int save_errno = errno;28582859strbuf_addf(err,"unable to append to '%s':%s",2860git_path("logs/%s", refname),strerror(save_errno));2861close(logfd);2862return-1;2863}2864if(close(logfd)) {2865int save_errno = errno;28662867strbuf_addf(err,"unable to append to '%s':%s",2868git_path("logs/%s", refname),strerror(save_errno));2869return-1;2870}2871return0;2872}28732874/*2875 * Write sha1 into the open lockfile, then close the lockfile. On2876 * errors, rollback the lockfile, fill in *err and2877 * return -1.2878 */2879static intwrite_ref_to_lockfile(struct ref_lock *lock,2880const unsigned char*sha1,struct strbuf *err)2881{2882static char term ='\n';2883struct object *o;2884int fd;28852886 o =parse_object(sha1);2887if(!o) {2888strbuf_addf(err,2889"trying to write ref '%s' with nonexistent object%s",2890 lock->ref_name,sha1_to_hex(sha1));2891unlock_ref(lock);2892return-1;2893}2894if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2895strbuf_addf(err,2896"trying to write non-commit object%sto branch '%s'",2897sha1_to_hex(sha1), lock->ref_name);2898unlock_ref(lock);2899return-1;2900}2901 fd =get_lock_file_fd(lock->lk);2902if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2903write_in_full(fd, &term,1) !=1||2904close_ref(lock) <0) {2905strbuf_addf(err,2906"couldn't write '%s'",get_lock_file_path(lock->lk));2907unlock_ref(lock);2908return-1;2909}2910return0;2911}29122913/*2914 * Commit a change to a loose reference that has already been written2915 * to the loose reference lockfile. Also update the reflogs if2916 * necessary, using the specified lockmsg (which can be NULL).2917 */2918static intcommit_ref_update(struct files_ref_store *refs,2919struct ref_lock *lock,2920const unsigned char*sha1,const char*logmsg,2921struct strbuf *err)2922{2923files_assert_main_repository(refs,"commit_ref_update");29242925clear_loose_ref_cache(refs);2926if(files_log_ref_write(lock->ref_name, lock->old_oid.hash, sha1,2927 logmsg,0, err)) {2928char*old_msg =strbuf_detach(err, NULL);2929strbuf_addf(err,"cannot update the ref '%s':%s",2930 lock->ref_name, old_msg);2931free(old_msg);2932unlock_ref(lock);2933return-1;2934}29352936if(strcmp(lock->ref_name,"HEAD") !=0) {2937/*2938 * Special hack: If a branch is updated directly and HEAD2939 * points to it (may happen on the remote side of a push2940 * for example) then logically the HEAD reflog should be2941 * updated too.2942 * A generic solution implies reverse symref information,2943 * but finding all symrefs pointing to the given branch2944 * would be rather costly for this rare event (the direct2945 * update of a branch) to be worth it. So let's cheat and2946 * check with HEAD only which should cover 99% of all usage2947 * scenarios (even 100% of the default ones).2948 */2949unsigned char head_sha1[20];2950int head_flag;2951const char*head_ref;29522953 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2954 head_sha1, &head_flag);2955if(head_ref && (head_flag & REF_ISSYMREF) &&2956!strcmp(head_ref, lock->ref_name)) {2957struct strbuf log_err = STRBUF_INIT;2958if(files_log_ref_write("HEAD", lock->old_oid.hash, sha1,2959 logmsg,0, &log_err)) {2960error("%s", log_err.buf);2961strbuf_release(&log_err);2962}2963}2964}29652966if(commit_ref(lock)) {2967strbuf_addf(err,"couldn't set '%s'", lock->ref_name);2968unlock_ref(lock);2969return-1;2970}29712972unlock_ref(lock);2973return0;2974}29752976static intcreate_ref_symlink(struct ref_lock *lock,const char*target)2977{2978int ret = -1;2979#ifndef NO_SYMLINK_HEAD2980char*ref_path =get_locked_file_path(lock->lk);2981unlink(ref_path);2982 ret =symlink(target, ref_path);2983free(ref_path);29842985if(ret)2986fprintf(stderr,"no symlink - falling back to symbolic ref\n");2987#endif2988return ret;2989}29902991static voidupdate_symref_reflog(struct ref_lock *lock,const char*refname,2992const char*target,const char*logmsg)2993{2994struct strbuf err = STRBUF_INIT;2995unsigned char new_sha1[20];2996if(logmsg && !read_ref(target, new_sha1) &&2997files_log_ref_write(refname, lock->old_oid.hash, new_sha1,2998 logmsg,0, &err)) {2999error("%s", err.buf);3000strbuf_release(&err);3001}3002}30033004static intcreate_symref_locked(struct ref_lock *lock,const char*refname,3005const char*target,const char*logmsg)3006{3007if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {3008update_symref_reflog(lock, refname, target, logmsg);3009return0;3010}30113012if(!fdopen_lock_file(lock->lk,"w"))3013returnerror("unable to fdopen%s:%s",3014 lock->lk->tempfile.filename.buf,strerror(errno));30153016update_symref_reflog(lock, refname, target, logmsg);30173018/* no error check; commit_ref will check ferror */3019fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);3020if(commit_ref(lock) <0)3021returnerror("unable to write symref for%s:%s", refname,3022strerror(errno));3023return0;3024}30253026static intfiles_create_symref(struct ref_store *ref_store,3027const char*refname,const char*target,3028const char*logmsg)3029{3030struct files_ref_store *refs =3031files_downcast(ref_store,0,"create_symref");3032struct strbuf err = STRBUF_INIT;3033struct ref_lock *lock;3034int ret;30353036 lock =lock_ref_sha1_basic(refs, refname, NULL,3037 NULL, NULL, REF_NODEREF, NULL,3038&err);3039if(!lock) {3040error("%s", err.buf);3041strbuf_release(&err);3042return-1;3043}30443045 ret =create_symref_locked(lock, refname, target, logmsg);3046unlock_ref(lock);3047return ret;3048}30493050intset_worktree_head_symref(const char*gitdir,const char*target,const char*logmsg)3051{3052static struct lock_file head_lock;3053struct ref_lock *lock;3054struct strbuf head_path = STRBUF_INIT;3055const char*head_rel;3056int ret;30573058strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));3059if(hold_lock_file_for_update(&head_lock, head_path.buf,3060 LOCK_NO_DEREF) <0) {3061struct strbuf err = STRBUF_INIT;3062unable_to_lock_message(head_path.buf, errno, &err);3063error("%s", err.buf);3064strbuf_release(&err);3065strbuf_release(&head_path);3066return-1;3067}30683069/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3070 linked trees */3071 head_rel =remove_leading_path(head_path.buf,3072absolute_path(get_git_common_dir()));3073/* to make use of create_symref_locked(), initialize ref_lock */3074 lock =xcalloc(1,sizeof(struct ref_lock));3075 lock->lk = &head_lock;3076 lock->ref_name =xstrdup(head_rel);30773078 ret =create_symref_locked(lock, head_rel, target, logmsg);30793080unlock_ref(lock);/* will free lock */3081strbuf_release(&head_path);3082return ret;3083}30843085static intfiles_reflog_exists(struct ref_store *ref_store,3086const char*refname)3087{3088struct stat st;30893090/* Check validity (but we don't need the result): */3091files_downcast(ref_store,0,"reflog_exists");30923093return!lstat(git_path("logs/%s", refname), &st) &&3094S_ISREG(st.st_mode);3095}30963097static intfiles_delete_reflog(struct ref_store *ref_store,3098const char*refname)3099{3100/* Check validity (but we don't need the result): */3101files_downcast(ref_store,0,"delete_reflog");31023103returnremove_path(git_path("logs/%s", refname));3104}31053106static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3107{3108struct object_id ooid, noid;3109char*email_end, *message;3110unsigned long timestamp;3111int tz;3112const char*p = sb->buf;31133114/* old SP new SP name <email> SP time TAB msg LF */3115if(!sb->len || sb->buf[sb->len -1] !='\n'||3116parse_oid_hex(p, &ooid, &p) || *p++ !=' '||3117parse_oid_hex(p, &noid, &p) || *p++ !=' '||3118!(email_end =strchr(p,'>')) ||3119 email_end[1] !=' '||3120!(timestamp =strtoul(email_end +2, &message,10)) ||3121!message || message[0] !=' '||3122(message[1] !='+'&& message[1] !='-') ||3123!isdigit(message[2]) || !isdigit(message[3]) ||3124!isdigit(message[4]) || !isdigit(message[5]))3125return0;/* corrupt? */3126 email_end[1] ='\0';3127 tz =strtol(message +1, NULL,10);3128if(message[6] !='\t')3129 message +=6;3130else3131 message +=7;3132returnfn(&ooid, &noid, p, timestamp, tz, message, cb_data);3133}31343135static char*find_beginning_of_line(char*bob,char*scan)3136{3137while(bob < scan && *(--scan) !='\n')3138;/* keep scanning backwards */3139/*3140 * Return either beginning of the buffer, or LF at the end of3141 * the previous line.3142 */3143return scan;3144}31453146static intfiles_for_each_reflog_ent_reverse(struct ref_store *ref_store,3147const char*refname,3148 each_reflog_ent_fn fn,3149void*cb_data)3150{3151struct strbuf sb = STRBUF_INIT;3152FILE*logfp;3153long pos;3154int ret =0, at_tail =1;31553156/* Check validity (but we don't need the result): */3157files_downcast(ref_store,0,"for_each_reflog_ent_reverse");31583159 logfp =fopen(git_path("logs/%s", refname),"r");3160if(!logfp)3161return-1;31623163/* Jump to the end */3164if(fseek(logfp,0, SEEK_END) <0)3165returnerror("cannot seek back reflog for%s:%s",3166 refname,strerror(errno));3167 pos =ftell(logfp);3168while(!ret &&0< pos) {3169int cnt;3170size_t nread;3171char buf[BUFSIZ];3172char*endp, *scanp;31733174/* Fill next block from the end */3175 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3176if(fseek(logfp, pos - cnt, SEEK_SET))3177returnerror("cannot seek back reflog for%s:%s",3178 refname,strerror(errno));3179 nread =fread(buf, cnt,1, logfp);3180if(nread !=1)3181returnerror("cannot read%dbytes from reflog for%s:%s",3182 cnt, refname,strerror(errno));3183 pos -= cnt;31843185 scanp = endp = buf + cnt;3186if(at_tail && scanp[-1] =='\n')3187/* Looking at the final LF at the end of the file */3188 scanp--;3189 at_tail =0;31903191while(buf < scanp) {3192/*3193 * terminating LF of the previous line, or the beginning3194 * of the buffer.3195 */3196char*bp;31973198 bp =find_beginning_of_line(buf, scanp);31993200if(*bp =='\n') {3201/*3202 * The newline is the end of the previous line,3203 * so we know we have complete line starting3204 * at (bp + 1). Prefix it onto any prior data3205 * we collected for the line and process it.3206 */3207strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3208 scanp = bp;3209 endp = bp +1;3210 ret =show_one_reflog_ent(&sb, fn, cb_data);3211strbuf_reset(&sb);3212if(ret)3213break;3214}else if(!pos) {3215/*3216 * We are at the start of the buffer, and the3217 * start of the file; there is no previous3218 * line, and we have everything for this one.3219 * Process it, and we can end the loop.3220 */3221strbuf_splice(&sb,0,0, buf, endp - buf);3222 ret =show_one_reflog_ent(&sb, fn, cb_data);3223strbuf_reset(&sb);3224break;3225}32263227if(bp == buf) {3228/*3229 * We are at the start of the buffer, and there3230 * is more file to read backwards. Which means3231 * we are in the middle of a line. Note that we3232 * may get here even if *bp was a newline; that3233 * just means we are at the exact end of the3234 * previous line, rather than some spot in the3235 * middle.3236 *3237 * Save away what we have to be combined with3238 * the data from the next read.3239 */3240strbuf_splice(&sb,0,0, buf, endp - buf);3241break;3242}3243}32443245}3246if(!ret && sb.len)3247die("BUG: reverse reflog parser had leftover data");32483249fclose(logfp);3250strbuf_release(&sb);3251return ret;3252}32533254static intfiles_for_each_reflog_ent(struct ref_store *ref_store,3255const char*refname,3256 each_reflog_ent_fn fn,void*cb_data)3257{3258FILE*logfp;3259struct strbuf sb = STRBUF_INIT;3260int ret =0;32613262/* Check validity (but we don't need the result): */3263files_downcast(ref_store,0,"for_each_reflog_ent");32643265 logfp =fopen(git_path("logs/%s", refname),"r");3266if(!logfp)3267return-1;32683269while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3270 ret =show_one_reflog_ent(&sb, fn, cb_data);3271fclose(logfp);3272strbuf_release(&sb);3273return ret;3274}32753276struct files_reflog_iterator {3277struct ref_iterator base;32783279struct dir_iterator *dir_iterator;3280struct object_id oid;3281};32823283static intfiles_reflog_iterator_advance(struct ref_iterator *ref_iterator)3284{3285struct files_reflog_iterator *iter =3286(struct files_reflog_iterator *)ref_iterator;3287struct dir_iterator *diter = iter->dir_iterator;3288int ok;32893290while((ok =dir_iterator_advance(diter)) == ITER_OK) {3291int flags;32923293if(!S_ISREG(diter->st.st_mode))3294continue;3295if(diter->basename[0] =='.')3296continue;3297if(ends_with(diter->basename,".lock"))3298continue;32993300if(read_ref_full(diter->relative_path,0,3301 iter->oid.hash, &flags)) {3302error("bad ref for%s", diter->path.buf);3303continue;3304}33053306 iter->base.refname = diter->relative_path;3307 iter->base.oid = &iter->oid;3308 iter->base.flags = flags;3309return ITER_OK;3310}33113312 iter->dir_iterator = NULL;3313if(ref_iterator_abort(ref_iterator) == ITER_ERROR)3314 ok = ITER_ERROR;3315return ok;3316}33173318static intfiles_reflog_iterator_peel(struct ref_iterator *ref_iterator,3319struct object_id *peeled)3320{3321die("BUG: ref_iterator_peel() called for reflog_iterator");3322}33233324static intfiles_reflog_iterator_abort(struct ref_iterator *ref_iterator)3325{3326struct files_reflog_iterator *iter =3327(struct files_reflog_iterator *)ref_iterator;3328int ok = ITER_DONE;33293330if(iter->dir_iterator)3331 ok =dir_iterator_abort(iter->dir_iterator);33323333base_ref_iterator_free(ref_iterator);3334return ok;3335}33363337static struct ref_iterator_vtable files_reflog_iterator_vtable = {3338 files_reflog_iterator_advance,3339 files_reflog_iterator_peel,3340 files_reflog_iterator_abort3341};33423343static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)3344{3345struct files_reflog_iterator *iter =xcalloc(1,sizeof(*iter));3346struct ref_iterator *ref_iterator = &iter->base;33473348/* Check validity (but we don't need the result): */3349files_downcast(ref_store,0,"reflog_iterator_begin");33503351base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3352 iter->dir_iterator =dir_iterator_begin(git_path("logs"));3353return ref_iterator;3354}33553356static intref_update_reject_duplicates(struct string_list *refnames,3357struct strbuf *err)3358{3359int i, n = refnames->nr;33603361assert(err);33623363for(i =1; i < n; i++)3364if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3365strbuf_addf(err,3366"multiple updates for ref '%s' not allowed.",3367 refnames->items[i].string);3368return1;3369}3370return0;3371}33723373/*3374 * If update is a direct update of head_ref (the reference pointed to3375 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3376 */3377static intsplit_head_update(struct ref_update *update,3378struct ref_transaction *transaction,3379const char*head_ref,3380struct string_list *affected_refnames,3381struct strbuf *err)3382{3383struct string_list_item *item;3384struct ref_update *new_update;33853386if((update->flags & REF_LOG_ONLY) ||3387(update->flags & REF_ISPRUNING) ||3388(update->flags & REF_UPDATE_VIA_HEAD))3389return0;33903391if(strcmp(update->refname, head_ref))3392return0;33933394/*3395 * First make sure that HEAD is not already in the3396 * transaction. This insertion is O(N) in the transaction3397 * size, but it happens at most once per transaction.3398 */3399 item =string_list_insert(affected_refnames,"HEAD");3400if(item->util) {3401/* An entry already existed */3402strbuf_addf(err,3403"multiple updates for 'HEAD' (including one "3404"via its referent '%s') are not allowed",3405 update->refname);3406return TRANSACTION_NAME_CONFLICT;3407}34083409 new_update =ref_transaction_add_update(3410 transaction,"HEAD",3411 update->flags | REF_LOG_ONLY | REF_NODEREF,3412 update->new_sha1, update->old_sha1,3413 update->msg);34143415 item->util = new_update;34163417return0;3418}34193420/*3421 * update is for a symref that points at referent and doesn't have3422 * REF_NODEREF set. Split it into two updates:3423 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3424 * - A new, separate update for the referent reference3425 * Note that the new update will itself be subject to splitting when3426 * the iteration gets to it.3427 */3428static intsplit_symref_update(struct files_ref_store *refs,3429struct ref_update *update,3430const char*referent,3431struct ref_transaction *transaction,3432struct string_list *affected_refnames,3433struct strbuf *err)3434{3435struct string_list_item *item;3436struct ref_update *new_update;3437unsigned int new_flags;34383439/*3440 * First make sure that referent is not already in the3441 * transaction. This insertion is O(N) in the transaction3442 * size, but it happens at most once per symref in a3443 * transaction.3444 */3445 item =string_list_insert(affected_refnames, referent);3446if(item->util) {3447/* An entry already existed */3448strbuf_addf(err,3449"multiple updates for '%s' (including one "3450"via symref '%s') are not allowed",3451 referent, update->refname);3452return TRANSACTION_NAME_CONFLICT;3453}34543455 new_flags = update->flags;3456if(!strcmp(update->refname,"HEAD")) {3457/*3458 * Record that the new update came via HEAD, so that3459 * when we process it, split_head_update() doesn't try3460 * to add another reflog update for HEAD. Note that3461 * this bit will be propagated if the new_update3462 * itself needs to be split.3463 */3464 new_flags |= REF_UPDATE_VIA_HEAD;3465}34663467 new_update =ref_transaction_add_update(3468 transaction, referent, new_flags,3469 update->new_sha1, update->old_sha1,3470 update->msg);34713472 new_update->parent_update = update;34733474/*3475 * Change the symbolic ref update to log only. Also, it3476 * doesn't need to check its old SHA-1 value, as that will be3477 * done when new_update is processed.3478 */3479 update->flags |= REF_LOG_ONLY | REF_NODEREF;3480 update->flags &= ~REF_HAVE_OLD;34813482 item->util = new_update;34833484return0;3485}34863487/*3488 * Return the refname under which update was originally requested.3489 */3490static const char*original_update_refname(struct ref_update *update)3491{3492while(update->parent_update)3493 update = update->parent_update;34943495return update->refname;3496}34973498/*3499 * Check whether the REF_HAVE_OLD and old_oid values stored in update3500 * are consistent with oid, which is the reference's current value. If3501 * everything is OK, return 0; otherwise, write an error message to3502 * err and return -1.3503 */3504static intcheck_old_oid(struct ref_update *update,struct object_id *oid,3505struct strbuf *err)3506{3507if(!(update->flags & REF_HAVE_OLD) ||3508!hashcmp(oid->hash, update->old_sha1))3509return0;35103511if(is_null_sha1(update->old_sha1))3512strbuf_addf(err,"cannot lock ref '%s': "3513"reference already exists",3514original_update_refname(update));3515else if(is_null_oid(oid))3516strbuf_addf(err,"cannot lock ref '%s': "3517"reference is missing but expected%s",3518original_update_refname(update),3519sha1_to_hex(update->old_sha1));3520else3521strbuf_addf(err,"cannot lock ref '%s': "3522"is at%sbut expected%s",3523original_update_refname(update),3524oid_to_hex(oid),3525sha1_to_hex(update->old_sha1));35263527return-1;3528}35293530/*3531 * Prepare for carrying out update:3532 * - Lock the reference referred to by update.3533 * - Read the reference under lock.3534 * - Check that its old SHA-1 value (if specified) is correct, and in3535 * any case record it in update->lock->old_oid for later use when3536 * writing the reflog.3537 * - If it is a symref update without REF_NODEREF, split it up into a3538 * REF_LOG_ONLY update of the symref and add a separate update for3539 * the referent to transaction.3540 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3541 * update of HEAD.3542 */3543static intlock_ref_for_update(struct files_ref_store *refs,3544struct ref_update *update,3545struct ref_transaction *transaction,3546const char*head_ref,3547struct string_list *affected_refnames,3548struct strbuf *err)3549{3550struct strbuf referent = STRBUF_INIT;3551int mustexist = (update->flags & REF_HAVE_OLD) &&3552!is_null_sha1(update->old_sha1);3553int ret;3554struct ref_lock *lock;35553556files_assert_main_repository(refs,"lock_ref_for_update");35573558if((update->flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3559 update->flags |= REF_DELETING;35603561if(head_ref) {3562 ret =split_head_update(update, transaction, head_ref,3563 affected_refnames, err);3564if(ret)3565return ret;3566}35673568 ret =lock_raw_ref(refs, update->refname, mustexist,3569 affected_refnames, NULL,3570&lock, &referent,3571&update->type, err);3572if(ret) {3573char*reason;35743575 reason =strbuf_detach(err, NULL);3576strbuf_addf(err,"cannot lock ref '%s':%s",3577original_update_refname(update), reason);3578free(reason);3579return ret;3580}35813582 update->backend_data = lock;35833584if(update->type & REF_ISSYMREF) {3585if(update->flags & REF_NODEREF) {3586/*3587 * We won't be reading the referent as part of3588 * the transaction, so we have to read it here3589 * to record and possibly check old_sha1:3590 */3591if(read_ref_full(referent.buf,0,3592 lock->old_oid.hash, NULL)) {3593if(update->flags & REF_HAVE_OLD) {3594strbuf_addf(err,"cannot lock ref '%s': "3595"error reading reference",3596original_update_refname(update));3597return-1;3598}3599}else if(check_old_oid(update, &lock->old_oid, err)) {3600return TRANSACTION_GENERIC_ERROR;3601}3602}else{3603/*3604 * Create a new update for the reference this3605 * symref is pointing at. Also, we will record3606 * and verify old_sha1 for this update as part3607 * of processing the split-off update, so we3608 * don't have to do it here.3609 */3610 ret =split_symref_update(refs, update,3611 referent.buf, transaction,3612 affected_refnames, err);3613if(ret)3614return ret;3615}3616}else{3617struct ref_update *parent_update;36183619if(check_old_oid(update, &lock->old_oid, err))3620return TRANSACTION_GENERIC_ERROR;36213622/*3623 * If this update is happening indirectly because of a3624 * symref update, record the old SHA-1 in the parent3625 * update:3626 */3627for(parent_update = update->parent_update;3628 parent_update;3629 parent_update = parent_update->parent_update) {3630struct ref_lock *parent_lock = parent_update->backend_data;3631oidcpy(&parent_lock->old_oid, &lock->old_oid);3632}3633}36343635if((update->flags & REF_HAVE_NEW) &&3636!(update->flags & REF_DELETING) &&3637!(update->flags & REF_LOG_ONLY)) {3638if(!(update->type & REF_ISSYMREF) &&3639!hashcmp(lock->old_oid.hash, update->new_sha1)) {3640/*3641 * The reference already has the desired3642 * value, so we don't need to write it.3643 */3644}else if(write_ref_to_lockfile(lock, update->new_sha1,3645 err)) {3646char*write_err =strbuf_detach(err, NULL);36473648/*3649 * The lock was freed upon failure of3650 * write_ref_to_lockfile():3651 */3652 update->backend_data = NULL;3653strbuf_addf(err,3654"cannot update ref '%s':%s",3655 update->refname, write_err);3656free(write_err);3657return TRANSACTION_GENERIC_ERROR;3658}else{3659 update->flags |= REF_NEEDS_COMMIT;3660}3661}3662if(!(update->flags & REF_NEEDS_COMMIT)) {3663/*3664 * We didn't call write_ref_to_lockfile(), so3665 * the lockfile is still open. Close it to3666 * free up the file descriptor:3667 */3668if(close_ref(lock)) {3669strbuf_addf(err,"couldn't close '%s.lock'",3670 update->refname);3671return TRANSACTION_GENERIC_ERROR;3672}3673}3674return0;3675}36763677static intfiles_transaction_commit(struct ref_store *ref_store,3678struct ref_transaction *transaction,3679struct strbuf *err)3680{3681struct files_ref_store *refs =3682files_downcast(ref_store,0,"ref_transaction_commit");3683int ret =0, i;3684struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3685struct string_list_item *ref_to_delete;3686struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3687char*head_ref = NULL;3688int head_type;3689struct object_id head_oid;36903691assert(err);36923693if(transaction->state != REF_TRANSACTION_OPEN)3694die("BUG: commit called for transaction that is not open");36953696if(!transaction->nr) {3697 transaction->state = REF_TRANSACTION_CLOSED;3698return0;3699}37003701/*3702 * Fail if a refname appears more than once in the3703 * transaction. (If we end up splitting up any updates using3704 * split_symref_update() or split_head_update(), those3705 * functions will check that the new updates don't have the3706 * same refname as any existing ones.)3707 */3708for(i =0; i < transaction->nr; i++) {3709struct ref_update *update = transaction->updates[i];3710struct string_list_item *item =3711string_list_append(&affected_refnames, update->refname);37123713/*3714 * We store a pointer to update in item->util, but at3715 * the moment we never use the value of this field3716 * except to check whether it is non-NULL.3717 */3718 item->util = update;3719}3720string_list_sort(&affected_refnames);3721if(ref_update_reject_duplicates(&affected_refnames, err)) {3722 ret = TRANSACTION_GENERIC_ERROR;3723goto cleanup;3724}37253726/*3727 * Special hack: If a branch is updated directly and HEAD3728 * points to it (may happen on the remote side of a push3729 * for example) then logically the HEAD reflog should be3730 * updated too.3731 *3732 * A generic solution would require reverse symref lookups,3733 * but finding all symrefs pointing to a given branch would be3734 * rather costly for this rare event (the direct update of a3735 * branch) to be worth it. So let's cheat and check with HEAD3736 * only, which should cover 99% of all usage scenarios (even3737 * 100% of the default ones).3738 *3739 * So if HEAD is a symbolic reference, then record the name of3740 * the reference that it points to. If we see an update of3741 * head_ref within the transaction, then split_head_update()3742 * arranges for the reflog of HEAD to be updated, too.3743 */3744 head_ref =resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3745 head_oid.hash, &head_type);37463747if(head_ref && !(head_type & REF_ISSYMREF)) {3748free(head_ref);3749 head_ref = NULL;3750}37513752/*3753 * Acquire all locks, verify old values if provided, check3754 * that new values are valid, and write new values to the3755 * lockfiles, ready to be activated. Only keep one lockfile3756 * open at a time to avoid running out of file descriptors.3757 */3758for(i =0; i < transaction->nr; i++) {3759struct ref_update *update = transaction->updates[i];37603761 ret =lock_ref_for_update(refs, update, transaction,3762 head_ref, &affected_refnames, err);3763if(ret)3764goto cleanup;3765}37663767/* Perform updates first so live commits remain referenced */3768for(i =0; i < transaction->nr; i++) {3769struct ref_update *update = transaction->updates[i];3770struct ref_lock *lock = update->backend_data;37713772if(update->flags & REF_NEEDS_COMMIT ||3773 update->flags & REF_LOG_ONLY) {3774if(files_log_ref_write(lock->ref_name,3775 lock->old_oid.hash,3776 update->new_sha1,3777 update->msg, update->flags,3778 err)) {3779char*old_msg =strbuf_detach(err, NULL);37803781strbuf_addf(err,"cannot update the ref '%s':%s",3782 lock->ref_name, old_msg);3783free(old_msg);3784unlock_ref(lock);3785 update->backend_data = NULL;3786 ret = TRANSACTION_GENERIC_ERROR;3787goto cleanup;3788}3789}3790if(update->flags & REF_NEEDS_COMMIT) {3791clear_loose_ref_cache(refs);3792if(commit_ref(lock)) {3793strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3794unlock_ref(lock);3795 update->backend_data = NULL;3796 ret = TRANSACTION_GENERIC_ERROR;3797goto cleanup;3798}3799}3800}3801/* Perform deletes now that updates are safely completed */3802for(i =0; i < transaction->nr; i++) {3803struct ref_update *update = transaction->updates[i];3804struct ref_lock *lock = update->backend_data;38053806if(update->flags & REF_DELETING &&3807!(update->flags & REF_LOG_ONLY)) {3808if(!(update->type & REF_ISPACKED) ||3809 update->type & REF_ISSYMREF) {3810/* It is a loose reference. */3811if(unlink_or_msg(git_path("%s", lock->ref_name), err)) {3812 ret = TRANSACTION_GENERIC_ERROR;3813goto cleanup;3814}3815 update->flags |= REF_DELETED_LOOSE;3816}38173818if(!(update->flags & REF_ISPRUNING))3819string_list_append(&refs_to_delete,3820 lock->ref_name);3821}3822}38233824if(repack_without_refs(refs, &refs_to_delete, err)) {3825 ret = TRANSACTION_GENERIC_ERROR;3826goto cleanup;3827}38283829/* Delete the reflogs of any references that were deleted: */3830for_each_string_list_item(ref_to_delete, &refs_to_delete) {3831if(!unlink_or_warn(git_path("logs/%s", ref_to_delete->string)))3832try_remove_empty_parents(ref_to_delete->string,3833 REMOVE_EMPTY_PARENTS_REFLOG);3834}38353836clear_loose_ref_cache(refs);38373838cleanup:3839 transaction->state = REF_TRANSACTION_CLOSED;38403841for(i =0; i < transaction->nr; i++) {3842struct ref_update *update = transaction->updates[i];3843struct ref_lock *lock = update->backend_data;38443845if(lock)3846unlock_ref(lock);38473848if(update->flags & REF_DELETED_LOOSE) {3849/*3850 * The loose reference was deleted. Delete any3851 * empty parent directories. (Note that this3852 * can only work because we have already3853 * removed the lockfile.)3854 */3855try_remove_empty_parents(update->refname,3856 REMOVE_EMPTY_PARENTS_REF);3857}3858}38593860string_list_clear(&refs_to_delete,0);3861free(head_ref);3862string_list_clear(&affected_refnames,0);38633864return ret;3865}38663867static intref_present(const char*refname,3868const struct object_id *oid,int flags,void*cb_data)3869{3870struct string_list *affected_refnames = cb_data;38713872returnstring_list_has_string(affected_refnames, refname);3873}38743875static intfiles_initial_transaction_commit(struct ref_store *ref_store,3876struct ref_transaction *transaction,3877struct strbuf *err)3878{3879struct files_ref_store *refs =3880files_downcast(ref_store,0,"initial_ref_transaction_commit");3881int ret =0, i;3882struct string_list affected_refnames = STRING_LIST_INIT_NODUP;38833884assert(err);38853886if(transaction->state != REF_TRANSACTION_OPEN)3887die("BUG: commit called for transaction that is not open");38883889/* Fail if a refname appears more than once in the transaction: */3890for(i =0; i < transaction->nr; i++)3891string_list_append(&affected_refnames,3892 transaction->updates[i]->refname);3893string_list_sort(&affected_refnames);3894if(ref_update_reject_duplicates(&affected_refnames, err)) {3895 ret = TRANSACTION_GENERIC_ERROR;3896goto cleanup;3897}38983899/*3900 * It's really undefined to call this function in an active3901 * repository or when there are existing references: we are3902 * only locking and changing packed-refs, so (1) any3903 * simultaneous processes might try to change a reference at3904 * the same time we do, and (2) any existing loose versions of3905 * the references that we are setting would have precedence3906 * over our values. But some remote helpers create the remote3907 * "HEAD" and "master" branches before calling this function,3908 * so here we really only check that none of the references3909 * that we are creating already exists.3910 */3911if(for_each_rawref(ref_present, &affected_refnames))3912die("BUG: initial ref transaction called with existing refs");39133914for(i =0; i < transaction->nr; i++) {3915struct ref_update *update = transaction->updates[i];39163917if((update->flags & REF_HAVE_OLD) &&3918!is_null_sha1(update->old_sha1))3919die("BUG: initial ref transaction with old_sha1 set");3920if(verify_refname_available(update->refname,3921&affected_refnames, NULL,3922 err)) {3923 ret = TRANSACTION_NAME_CONFLICT;3924goto cleanup;3925}3926}39273928if(lock_packed_refs(refs,0)) {3929strbuf_addf(err,"unable to lock packed-refs file:%s",3930strerror(errno));3931 ret = TRANSACTION_GENERIC_ERROR;3932goto cleanup;3933}39343935for(i =0; i < transaction->nr; i++) {3936struct ref_update *update = transaction->updates[i];39373938if((update->flags & REF_HAVE_NEW) &&3939!is_null_sha1(update->new_sha1))3940add_packed_ref(refs, update->refname, update->new_sha1);3941}39423943if(commit_packed_refs(refs)) {3944strbuf_addf(err,"unable to commit packed-refs file:%s",3945strerror(errno));3946 ret = TRANSACTION_GENERIC_ERROR;3947goto cleanup;3948}39493950cleanup:3951 transaction->state = REF_TRANSACTION_CLOSED;3952string_list_clear(&affected_refnames,0);3953return ret;3954}39553956struct expire_reflog_cb {3957unsigned int flags;3958 reflog_expiry_should_prune_fn *should_prune_fn;3959void*policy_cb;3960FILE*newlog;3961struct object_id last_kept_oid;3962};39633964static intexpire_reflog_ent(struct object_id *ooid,struct object_id *noid,3965const char*email,unsigned long timestamp,int tz,3966const char*message,void*cb_data)3967{3968struct expire_reflog_cb *cb = cb_data;3969struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39703971if(cb->flags & EXPIRE_REFLOGS_REWRITE)3972 ooid = &cb->last_kept_oid;39733974if((*cb->should_prune_fn)(ooid->hash, noid->hash, email, timestamp, tz,3975 message, policy_cb)) {3976if(!cb->newlog)3977printf("would prune%s", message);3978else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3979printf("prune%s", message);3980}else{3981if(cb->newlog) {3982fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",3983oid_to_hex(ooid),oid_to_hex(noid),3984 email, timestamp, tz, message);3985oidcpy(&cb->last_kept_oid, noid);3986}3987if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3988printf("keep%s", message);3989}3990return0;3991}39923993static intfiles_reflog_expire(struct ref_store *ref_store,3994const char*refname,const unsigned char*sha1,3995unsigned int flags,3996 reflog_expiry_prepare_fn prepare_fn,3997 reflog_expiry_should_prune_fn should_prune_fn,3998 reflog_expiry_cleanup_fn cleanup_fn,3999void*policy_cb_data)4000{4001struct files_ref_store *refs =4002files_downcast(ref_store,0,"reflog_expire");4003static struct lock_file reflog_lock;4004struct expire_reflog_cb cb;4005struct ref_lock *lock;4006char*log_file;4007int status =0;4008int type;4009struct strbuf err = STRBUF_INIT;40104011memset(&cb,0,sizeof(cb));4012 cb.flags = flags;4013 cb.policy_cb = policy_cb_data;4014 cb.should_prune_fn = should_prune_fn;40154016/*4017 * The reflog file is locked by holding the lock on the4018 * reference itself, plus we might need to update the4019 * reference if --updateref was specified:4020 */4021 lock =lock_ref_sha1_basic(refs, refname, sha1,4022 NULL, NULL, REF_NODEREF,4023&type, &err);4024if(!lock) {4025error("cannot lock ref '%s':%s", refname, err.buf);4026strbuf_release(&err);4027return-1;4028}4029if(!reflog_exists(refname)) {4030unlock_ref(lock);4031return0;4032}40334034 log_file =git_pathdup("logs/%s", refname);4035if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4036/*4037 * Even though holding $GIT_DIR/logs/$reflog.lock has4038 * no locking implications, we use the lock_file4039 * machinery here anyway because it does a lot of the4040 * work we need, including cleaning up if the program4041 * exits unexpectedly.4042 */4043if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4044struct strbuf err = STRBUF_INIT;4045unable_to_lock_message(log_file, errno, &err);4046error("%s", err.buf);4047strbuf_release(&err);4048goto failure;4049}4050 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4051if(!cb.newlog) {4052error("cannot fdopen%s(%s)",4053get_lock_file_path(&reflog_lock),strerror(errno));4054goto failure;4055}4056}40574058(*prepare_fn)(refname, sha1, cb.policy_cb);4059for_each_reflog_ent(refname, expire_reflog_ent, &cb);4060(*cleanup_fn)(cb.policy_cb);40614062if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4063/*4064 * It doesn't make sense to adjust a reference pointed4065 * to by a symbolic ref based on expiring entries in4066 * the symbolic reference's reflog. Nor can we update4067 * a reference if there are no remaining reflog4068 * entries.4069 */4070int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4071!(type & REF_ISSYMREF) &&4072!is_null_oid(&cb.last_kept_oid);40734074if(close_lock_file(&reflog_lock)) {4075 status |=error("couldn't write%s:%s", log_file,4076strerror(errno));4077}else if(update &&4078(write_in_full(get_lock_file_fd(lock->lk),4079oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||4080write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||4081close_ref(lock) <0)) {4082 status |=error("couldn't write%s",4083get_lock_file_path(lock->lk));4084rollback_lock_file(&reflog_lock);4085}else if(commit_lock_file(&reflog_lock)) {4086 status |=error("unable to write reflog '%s' (%s)",4087 log_file,strerror(errno));4088}else if(update &&commit_ref(lock)) {4089 status |=error("couldn't set%s", lock->ref_name);4090}4091}4092free(log_file);4093unlock_ref(lock);4094return status;40954096 failure:4097rollback_lock_file(&reflog_lock);4098free(log_file);4099unlock_ref(lock);4100return-1;4101}41024103static intfiles_init_db(struct ref_store *ref_store,struct strbuf *err)4104{4105/* Check validity (but we don't need the result): */4106files_downcast(ref_store,0,"init_db");41074108/*4109 * Create .git/refs/{heads,tags}4110 */4111safe_create_dir(git_path("refs/heads"),1);4112safe_create_dir(git_path("refs/tags"),1);4113if(get_shared_repository()) {4114adjust_shared_perm(git_path("refs/heads"));4115adjust_shared_perm(git_path("refs/tags"));4116}4117return0;4118}41194120struct ref_storage_be refs_be_files = {4121 NULL,4122"files",4123 files_ref_store_create,4124 files_init_db,4125 files_transaction_commit,4126 files_initial_transaction_commit,41274128 files_pack_refs,4129 files_peel_ref,4130 files_create_symref,4131 files_delete_refs,4132 files_rename_ref,41334134 files_ref_iterator_begin,4135 files_read_raw_ref,4136 files_verify_refname_available,41374138 files_reflog_iterator_begin,4139 files_for_each_reflog_ent,4140 files_for_each_reflog_ent_reverse,4141 files_reflog_exists,4142 files_create_reflog,4143 files_delete_reflog,4144 files_reflog_expire4145};