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 926char*packed_refs_path; 927 928struct ref_entry *loose; 929struct packed_ref_cache *packed; 930}; 931 932/* Lock used for the main packed-refs file: */ 933static struct lock_file packlock; 934 935/* 936 * Increment the reference count of *packed_refs. 937 */ 938static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 939{ 940 packed_refs->referrers++; 941} 942 943/* 944 * Decrease the reference count of *packed_refs. If it goes to zero, 945 * free *packed_refs and return true; otherwise return false. 946 */ 947static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 948{ 949if(!--packed_refs->referrers) { 950free_ref_entry(packed_refs->root); 951stat_validity_clear(&packed_refs->validity); 952free(packed_refs); 953return1; 954}else{ 955return0; 956} 957} 958 959static voidclear_packed_ref_cache(struct files_ref_store *refs) 960{ 961if(refs->packed) { 962struct packed_ref_cache *packed_refs = refs->packed; 963 964if(packed_refs->lock) 965die("internal error: packed-ref cache cleared while locked"); 966 refs->packed = NULL; 967release_packed_ref_cache(packed_refs); 968} 969} 970 971static voidclear_loose_ref_cache(struct files_ref_store *refs) 972{ 973if(refs->loose) { 974free_ref_entry(refs->loose); 975 refs->loose = NULL; 976} 977} 978 979/* 980 * Create a new submodule ref cache and add it to the internal 981 * set of caches. 982 */ 983static struct ref_store *files_ref_store_create(const char*submodule) 984{ 985struct files_ref_store *refs =xcalloc(1,sizeof(*refs)); 986struct ref_store *ref_store = (struct ref_store *)refs; 987 988base_ref_store_init(ref_store, &refs_be_files); 989 990if(submodule) { 991 refs->submodule =xstrdup(submodule); 992 refs->packed_refs_path =git_pathdup_submodule( 993 refs->submodule,"packed-refs"); 994return ref_store; 995} 996 997 refs->packed_refs_path =git_pathdup("packed-refs"); 998 999return ref_store;1000}10011002/*1003 * Die if refs is for a submodule (i.e., not for the main repository).1004 * caller is used in any necessary error messages.1005 */1006static voidfiles_assert_main_repository(struct files_ref_store *refs,1007const char*caller)1008{1009if(refs->submodule)1010die("BUG:%scalled for a submodule", caller);1011}10121013/*1014 * Downcast ref_store to files_ref_store. Die if ref_store is not a1015 * files_ref_store. If submodule_allowed is not true, then also die if1016 * files_ref_store is for a submodule (i.e., not for the main1017 * repository). caller is used in any necessary error messages.1018 */1019static struct files_ref_store *files_downcast(1020struct ref_store *ref_store,int submodule_allowed,1021const char*caller)1022{1023struct files_ref_store *refs;10241025if(ref_store->be != &refs_be_files)1026die("BUG: ref_store is type\"%s\"not\"files\"in%s",1027 ref_store->be->name, caller);10281029 refs = (struct files_ref_store *)ref_store;10301031if(!submodule_allowed)1032files_assert_main_repository(refs, caller);10331034return refs;1035}10361037/* The length of a peeled reference line in packed-refs, including EOL: */1038#define PEELED_LINE_LENGTH 4210391040/*1041 * The packed-refs header line that we write out. Perhaps other1042 * traits will be added later. The trailing space is required.1043 */1044static const char PACKED_REFS_HEADER[] =1045"# pack-refs with: peeled fully-peeled\n";10461047/*1048 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1049 * Return a pointer to the refname within the line (null-terminated),1050 * or NULL if there was a problem.1051 */1052static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1053{1054const char*ref;10551056/*1057 * 42: the answer to everything.1058 *1059 * In this case, it happens to be the answer to1060 * 40 (length of sha1 hex representation)1061 * +1 (space in between hex and name)1062 * +1 (newline at the end of the line)1063 */1064if(line->len <=42)1065return NULL;10661067if(get_sha1_hex(line->buf, sha1) <0)1068return NULL;1069if(!isspace(line->buf[40]))1070return NULL;10711072 ref = line->buf +41;1073if(isspace(*ref))1074return NULL;10751076if(line->buf[line->len -1] !='\n')1077return NULL;1078 line->buf[--line->len] =0;10791080return ref;1081}10821083/*1084 * Read f, which is a packed-refs file, into dir.1085 *1086 * A comment line of the form "# pack-refs with: " may contain zero or1087 * more traits. We interpret the traits as follows:1088 *1089 * No traits:1090 *1091 * Probably no references are peeled. But if the file contains a1092 * peeled value for a reference, we will use it.1093 *1094 * peeled:1095 *1096 * References under "refs/tags/", if they *can* be peeled, *are*1097 * peeled in this file. References outside of "refs/tags/" are1098 * probably not peeled even if they could have been, but if we find1099 * a peeled value for such a reference we will use it.1100 *1101 * fully-peeled:1102 *1103 * All references in the file that can be peeled are peeled.1104 * Inversely (and this is more important), any references in the1105 * file for which no peeled value is recorded is not peelable. This1106 * trait should typically be written alongside "peeled" for1107 * compatibility with older clients, but we do not require it1108 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1109 */1110static voidread_packed_refs(FILE*f,struct ref_dir *dir)1111{1112struct ref_entry *last = NULL;1113struct strbuf line = STRBUF_INIT;1114enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11151116while(strbuf_getwholeline(&line, f,'\n') != EOF) {1117unsigned char sha1[20];1118const char*refname;1119const char*traits;11201121if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1122if(strstr(traits," fully-peeled "))1123 peeled = PEELED_FULLY;1124else if(strstr(traits," peeled "))1125 peeled = PEELED_TAGS;1126/* perhaps other traits later as well */1127continue;1128}11291130 refname =parse_ref_line(&line, sha1);1131if(refname) {1132int flag = REF_ISPACKED;11331134if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1135if(!refname_is_safe(refname))1136die("packed refname is dangerous:%s", refname);1137hashclr(sha1);1138 flag |= REF_BAD_NAME | REF_ISBROKEN;1139}1140 last =create_ref_entry(refname, sha1, flag,0);1141if(peeled == PEELED_FULLY ||1142(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1143 last->flag |= REF_KNOWS_PEELED;1144add_ref(dir, last);1145continue;1146}1147if(last &&1148 line.buf[0] =='^'&&1149 line.len == PEELED_LINE_LENGTH &&1150 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1151!get_sha1_hex(line.buf +1, sha1)) {1152hashcpy(last->u.value.peeled.hash, sha1);1153/*1154 * Regardless of what the file header said,1155 * we definitely know the value of *this*1156 * reference:1157 */1158 last->flag |= REF_KNOWS_PEELED;1159}1160}11611162strbuf_release(&line);1163}11641165static const char*files_packed_refs_path(struct files_ref_store *refs)1166{1167return refs->packed_refs_path;1168}11691170/*1171 * Get the packed_ref_cache for the specified files_ref_store,1172 * creating it if necessary.1173 */1174static struct packed_ref_cache *get_packed_ref_cache(struct files_ref_store *refs)1175{1176const char*packed_refs_file =files_packed_refs_path(refs);11771178if(refs->packed &&1179!stat_validity_check(&refs->packed->validity, packed_refs_file))1180clear_packed_ref_cache(refs);11811182if(!refs->packed) {1183FILE*f;11841185 refs->packed =xcalloc(1,sizeof(*refs->packed));1186acquire_packed_ref_cache(refs->packed);1187 refs->packed->root =create_dir_entry(refs,"",0,0);1188 f =fopen(packed_refs_file,"r");1189if(f) {1190stat_validity_update(&refs->packed->validity,fileno(f));1191read_packed_refs(f,get_ref_dir(refs->packed->root));1192fclose(f);1193}1194}1195return refs->packed;1196}11971198static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1199{1200returnget_ref_dir(packed_ref_cache->root);1201}12021203static struct ref_dir *get_packed_refs(struct files_ref_store *refs)1204{1205returnget_packed_ref_dir(get_packed_ref_cache(refs));1206}12071208/*1209 * Add a reference to the in-memory packed reference cache. This may1210 * only be called while the packed-refs file is locked (see1211 * lock_packed_refs()). To actually write the packed-refs file, call1212 * commit_packed_refs().1213 */1214static voidadd_packed_ref(struct files_ref_store *refs,1215const char*refname,const unsigned char*sha1)1216{1217struct packed_ref_cache *packed_ref_cache =get_packed_ref_cache(refs);12181219if(!packed_ref_cache->lock)1220die("internal error: packed refs not locked");1221add_ref(get_packed_ref_dir(packed_ref_cache),1222create_ref_entry(refname, sha1, REF_ISPACKED,1));1223}12241225/*1226 * Read the loose references from the namespace dirname into dir1227 * (without recursing). dirname must end with '/'. dir must be the1228 * directory entry corresponding to dirname.1229 */1230static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1231{1232struct files_ref_store *refs = dir->ref_store;1233DIR*d;1234struct dirent *de;1235int dirnamelen =strlen(dirname);1236struct strbuf refname;1237struct strbuf path = STRBUF_INIT;1238size_t path_baselen;1239int err =0;12401241if(refs->submodule)1242 err =strbuf_git_path_submodule(&path, refs->submodule,"%s", dirname);1243else1244strbuf_git_path(&path,"%s", dirname);1245 path_baselen = path.len;12461247if(err) {1248strbuf_release(&path);1249return;1250}12511252 d =opendir(path.buf);1253if(!d) {1254strbuf_release(&path);1255return;1256}12571258strbuf_init(&refname, dirnamelen +257);1259strbuf_add(&refname, dirname, dirnamelen);12601261while((de =readdir(d)) != NULL) {1262unsigned char sha1[20];1263struct stat st;1264int flag;12651266if(de->d_name[0] =='.')1267continue;1268if(ends_with(de->d_name,".lock"))1269continue;1270strbuf_addstr(&refname, de->d_name);1271strbuf_addstr(&path, de->d_name);1272if(stat(path.buf, &st) <0) {1273;/* silently ignore */1274}else if(S_ISDIR(st.st_mode)) {1275strbuf_addch(&refname,'/');1276add_entry_to_dir(dir,1277create_dir_entry(refs, refname.buf,1278 refname.len,1));1279}else{1280if(!resolve_ref_recursively(&refs->base,1281 refname.buf,1282 RESOLVE_REF_READING,1283 sha1, &flag)) {1284hashclr(sha1);1285 flag |= REF_ISBROKEN;1286}else if(is_null_sha1(sha1)) {1287/*1288 * It is so astronomically unlikely1289 * that NULL_SHA1 is the SHA-1 of an1290 * actual object that we consider its1291 * appearance in a loose reference1292 * file to be repo corruption1293 * (probably due to a software bug).1294 */1295 flag |= REF_ISBROKEN;1296}12971298if(check_refname_format(refname.buf,1299 REFNAME_ALLOW_ONELEVEL)) {1300if(!refname_is_safe(refname.buf))1301die("loose refname is dangerous:%s", refname.buf);1302hashclr(sha1);1303 flag |= REF_BAD_NAME | REF_ISBROKEN;1304}1305add_entry_to_dir(dir,1306create_ref_entry(refname.buf, sha1, flag,0));1307}1308strbuf_setlen(&refname, dirnamelen);1309strbuf_setlen(&path, path_baselen);1310}1311strbuf_release(&refname);1312strbuf_release(&path);1313closedir(d);1314}13151316static struct ref_dir *get_loose_refs(struct files_ref_store *refs)1317{1318if(!refs->loose) {1319/*1320 * Mark the top-level directory complete because we1321 * are about to read the only subdirectory that can1322 * hold references:1323 */1324 refs->loose =create_dir_entry(refs,"",0,0);1325/*1326 * Create an incomplete entry for "refs/":1327 */1328add_entry_to_dir(get_ref_dir(refs->loose),1329create_dir_entry(refs,"refs/",5,1));1330}1331returnget_ref_dir(refs->loose);1332}13331334/*1335 * Return the ref_entry for the given refname from the packed1336 * references. If it does not exist, return NULL.1337 */1338static struct ref_entry *get_packed_ref(struct files_ref_store *refs,1339const char*refname)1340{1341returnfind_ref(get_packed_refs(refs), refname);1342}13431344/*1345 * A loose ref file doesn't exist; check for a packed ref.1346 */1347static intresolve_packed_ref(struct files_ref_store *refs,1348const char*refname,1349unsigned char*sha1,unsigned int*flags)1350{1351struct ref_entry *entry;13521353/*1354 * The loose reference file does not exist; check for a packed1355 * reference.1356 */1357 entry =get_packed_ref(refs, refname);1358if(entry) {1359hashcpy(sha1, entry->u.value.oid.hash);1360*flags |= REF_ISPACKED;1361return0;1362}1363/* refname is not a packed reference. */1364return-1;1365}13661367static intfiles_read_raw_ref(struct ref_store *ref_store,1368const char*refname,unsigned char*sha1,1369struct strbuf *referent,unsigned int*type)1370{1371struct files_ref_store *refs =1372files_downcast(ref_store,1,"read_raw_ref");1373struct strbuf sb_contents = STRBUF_INIT;1374struct strbuf sb_path = STRBUF_INIT;1375const char*path;1376const char*buf;1377struct stat st;1378int fd;1379int ret = -1;1380int save_errno;1381int remaining_retries =3;13821383*type =0;1384strbuf_reset(&sb_path);13851386if(refs->submodule)1387strbuf_git_path_submodule(&sb_path, refs->submodule,"%s", refname);1388else1389strbuf_git_path(&sb_path,"%s", refname);13901391 path = sb_path.buf;13921393stat_ref:1394/*1395 * We might have to loop back here to avoid a race1396 * condition: first we lstat() the file, then we try1397 * to read it as a link or as a file. But if somebody1398 * changes the type of the file (file <-> directory1399 * <-> symlink) between the lstat() and reading, then1400 * we don't want to report that as an error but rather1401 * try again starting with the lstat().1402 *1403 * We'll keep a count of the retries, though, just to avoid1404 * any confusing situation sending us into an infinite loop.1405 */14061407if(remaining_retries-- <=0)1408goto out;14091410if(lstat(path, &st) <0) {1411if(errno != ENOENT)1412goto out;1413if(resolve_packed_ref(refs, refname, sha1, type)) {1414 errno = ENOENT;1415goto out;1416}1417 ret =0;1418goto out;1419}14201421/* Follow "normalized" - ie "refs/.." symlinks by hand */1422if(S_ISLNK(st.st_mode)) {1423strbuf_reset(&sb_contents);1424if(strbuf_readlink(&sb_contents, path,0) <0) {1425if(errno == ENOENT || errno == EINVAL)1426/* inconsistent with lstat; retry */1427goto stat_ref;1428else1429goto out;1430}1431if(starts_with(sb_contents.buf,"refs/") &&1432!check_refname_format(sb_contents.buf,0)) {1433strbuf_swap(&sb_contents, referent);1434*type |= REF_ISSYMREF;1435 ret =0;1436goto out;1437}1438/*1439 * It doesn't look like a refname; fall through to just1440 * treating it like a non-symlink, and reading whatever it1441 * points to.1442 */1443}14441445/* Is it a directory? */1446if(S_ISDIR(st.st_mode)) {1447/*1448 * Even though there is a directory where the loose1449 * ref is supposed to be, there could still be a1450 * packed ref:1451 */1452if(resolve_packed_ref(refs, refname, sha1, type)) {1453 errno = EISDIR;1454goto out;1455}1456 ret =0;1457goto out;1458}14591460/*1461 * Anything else, just open it and try to use it as1462 * a ref1463 */1464 fd =open(path, O_RDONLY);1465if(fd <0) {1466if(errno == ENOENT && !S_ISLNK(st.st_mode))1467/* inconsistent with lstat; retry */1468goto stat_ref;1469else1470goto out;1471}1472strbuf_reset(&sb_contents);1473if(strbuf_read(&sb_contents, fd,256) <0) {1474int save_errno = errno;1475close(fd);1476 errno = save_errno;1477goto out;1478}1479close(fd);1480strbuf_rtrim(&sb_contents);1481 buf = sb_contents.buf;1482if(starts_with(buf,"ref:")) {1483 buf +=4;1484while(isspace(*buf))1485 buf++;14861487strbuf_reset(referent);1488strbuf_addstr(referent, buf);1489*type |= REF_ISSYMREF;1490 ret =0;1491goto out;1492}14931494/*1495 * Please note that FETCH_HEAD has additional1496 * data after the sha.1497 */1498if(get_sha1_hex(buf, sha1) ||1499(buf[40] !='\0'&& !isspace(buf[40]))) {1500*type |= REF_ISBROKEN;1501 errno = EINVAL;1502goto out;1503}15041505 ret =0;15061507out:1508 save_errno = errno;1509strbuf_release(&sb_path);1510strbuf_release(&sb_contents);1511 errno = save_errno;1512return ret;1513}15141515static voidunlock_ref(struct ref_lock *lock)1516{1517/* Do not free lock->lk -- atexit() still looks at them */1518if(lock->lk)1519rollback_lock_file(lock->lk);1520free(lock->ref_name);1521free(lock);1522}15231524/*1525 * Lock refname, without following symrefs, and set *lock_p to point1526 * at a newly-allocated lock object. Fill in lock->old_oid, referent,1527 * and type similarly to read_raw_ref().1528 *1529 * The caller must verify that refname is a "safe" reference name (in1530 * the sense of refname_is_safe()) before calling this function.1531 *1532 * If the reference doesn't already exist, verify that refname doesn't1533 * have a D/F conflict with any existing references. extras and skip1534 * are passed to verify_refname_available_dir() for this check.1535 *1536 * If mustexist is not set and the reference is not found or is1537 * broken, lock the reference anyway but clear sha1.1538 *1539 * Return 0 on success. On failure, write an error message to err and1540 * return TRANSACTION_NAME_CONFLICT or TRANSACTION_GENERIC_ERROR.1541 *1542 * Implementation note: This function is basically1543 *1544 * lock reference1545 * read_raw_ref()1546 *1547 * but it includes a lot more code to1548 * - Deal with possible races with other processes1549 * - Avoid calling verify_refname_available_dir() when it can be1550 * avoided, namely if we were successfully able to read the ref1551 * - Generate informative error messages in the case of failure1552 */1553static intlock_raw_ref(struct files_ref_store *refs,1554const char*refname,int mustexist,1555const struct string_list *extras,1556const struct string_list *skip,1557struct ref_lock **lock_p,1558struct strbuf *referent,1559unsigned int*type,1560struct strbuf *err)1561{1562struct ref_lock *lock;1563struct strbuf ref_file = STRBUF_INIT;1564int attempts_remaining =3;1565int ret = TRANSACTION_GENERIC_ERROR;15661567assert(err);1568files_assert_main_repository(refs,"lock_raw_ref");15691570*type =0;15711572/* First lock the file so it can't change out from under us. */15731574*lock_p = lock =xcalloc(1,sizeof(*lock));15751576 lock->ref_name =xstrdup(refname);1577strbuf_git_path(&ref_file,"%s", refname);15781579retry:1580switch(safe_create_leading_directories(ref_file.buf)) {1581case SCLD_OK:1582break;/* success */1583case SCLD_EXISTS:1584/*1585 * Suppose refname is "refs/foo/bar". We just failed1586 * to create the containing directory, "refs/foo",1587 * because there was a non-directory in the way. This1588 * indicates a D/F conflict, probably because of1589 * another reference such as "refs/foo". There is no1590 * reason to expect this error to be transitory.1591 */1592if(verify_refname_available(refname, extras, skip, err)) {1593if(mustexist) {1594/*1595 * To the user the relevant error is1596 * that the "mustexist" reference is1597 * missing:1598 */1599strbuf_reset(err);1600strbuf_addf(err,"unable to resolve reference '%s'",1601 refname);1602}else{1603/*1604 * The error message set by1605 * verify_refname_available_dir() is OK.1606 */1607 ret = TRANSACTION_NAME_CONFLICT;1608}1609}else{1610/*1611 * The file that is in the way isn't a loose1612 * reference. Report it as a low-level1613 * failure.1614 */1615strbuf_addf(err,"unable to create lock file%s.lock; "1616"non-directory in the way",1617 ref_file.buf);1618}1619goto error_return;1620case SCLD_VANISHED:1621/* Maybe another process was tidying up. Try again. */1622if(--attempts_remaining >0)1623goto retry;1624/* fall through */1625default:1626strbuf_addf(err,"unable to create directory for%s",1627 ref_file.buf);1628goto error_return;1629}16301631if(!lock->lk)1632 lock->lk =xcalloc(1,sizeof(struct lock_file));16331634if(hold_lock_file_for_update(lock->lk, ref_file.buf, LOCK_NO_DEREF) <0) {1635if(errno == ENOENT && --attempts_remaining >0) {1636/*1637 * Maybe somebody just deleted one of the1638 * directories leading to ref_file. Try1639 * again:1640 */1641goto retry;1642}else{1643unable_to_lock_message(ref_file.buf, errno, err);1644goto error_return;1645}1646}16471648/*1649 * Now we hold the lock and can read the reference without1650 * fear that its value will change.1651 */16521653if(files_read_raw_ref(&refs->base, refname,1654 lock->old_oid.hash, referent, type)) {1655if(errno == ENOENT) {1656if(mustexist) {1657/* Garden variety missing reference. */1658strbuf_addf(err,"unable to resolve reference '%s'",1659 refname);1660goto error_return;1661}else{1662/*1663 * Reference is missing, but that's OK. We1664 * know that there is not a conflict with1665 * another loose reference because1666 * (supposing that we are trying to lock1667 * reference "refs/foo/bar"):1668 *1669 * - We were successfully able to create1670 * the lockfile refs/foo/bar.lock, so we1671 * know there cannot be a loose reference1672 * named "refs/foo".1673 *1674 * - We got ENOENT and not EISDIR, so we1675 * know that there cannot be a loose1676 * reference named "refs/foo/bar/baz".1677 */1678}1679}else if(errno == EISDIR) {1680/*1681 * There is a directory in the way. It might have1682 * contained references that have been deleted. If1683 * we don't require that the reference already1684 * exists, try to remove the directory so that it1685 * doesn't cause trouble when we want to rename the1686 * lockfile into place later.1687 */1688if(mustexist) {1689/* Garden variety missing reference. */1690strbuf_addf(err,"unable to resolve reference '%s'",1691 refname);1692goto error_return;1693}else if(remove_dir_recursively(&ref_file,1694 REMOVE_DIR_EMPTY_ONLY)) {1695if(verify_refname_available_dir(1696 refname, extras, skip,1697get_loose_refs(refs),1698 err)) {1699/*1700 * The error message set by1701 * verify_refname_available() is OK.1702 */1703 ret = TRANSACTION_NAME_CONFLICT;1704goto error_return;1705}else{1706/*1707 * We can't delete the directory,1708 * but we also don't know of any1709 * references that it should1710 * contain.1711 */1712strbuf_addf(err,"there is a non-empty directory '%s' "1713"blocking reference '%s'",1714 ref_file.buf, refname);1715goto error_return;1716}1717}1718}else if(errno == EINVAL && (*type & REF_ISBROKEN)) {1719strbuf_addf(err,"unable to resolve reference '%s': "1720"reference broken", refname);1721goto error_return;1722}else{1723strbuf_addf(err,"unable to resolve reference '%s':%s",1724 refname,strerror(errno));1725goto error_return;1726}17271728/*1729 * If the ref did not exist and we are creating it,1730 * make sure there is no existing packed ref whose1731 * name begins with our refname, nor a packed ref1732 * whose name is a proper prefix of our refname.1733 */1734if(verify_refname_available_dir(1735 refname, extras, skip,1736get_packed_refs(refs),1737 err)) {1738goto error_return;1739}1740}17411742 ret =0;1743goto out;17441745error_return:1746unlock_ref(lock);1747*lock_p = NULL;17481749out:1750strbuf_release(&ref_file);1751return ret;1752}17531754/*1755 * Peel the entry (if possible) and return its new peel_status. If1756 * repeel is true, re-peel the entry even if there is an old peeled1757 * value that is already stored in it.1758 *1759 * It is OK to call this function with a packed reference entry that1760 * might be stale and might even refer to an object that has since1761 * been garbage-collected. In such a case, if the entry has1762 * REF_KNOWS_PEELED then leave the status unchanged and return1763 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1764 */1765static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1766{1767enum peel_status status;17681769if(entry->flag & REF_KNOWS_PEELED) {1770if(repeel) {1771 entry->flag &= ~REF_KNOWS_PEELED;1772oidclr(&entry->u.value.peeled);1773}else{1774returnis_null_oid(&entry->u.value.peeled) ?1775 PEEL_NON_TAG : PEEL_PEELED;1776}1777}1778if(entry->flag & REF_ISBROKEN)1779return PEEL_BROKEN;1780if(entry->flag & REF_ISSYMREF)1781return PEEL_IS_SYMREF;17821783 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1784if(status == PEEL_PEELED || status == PEEL_NON_TAG)1785 entry->flag |= REF_KNOWS_PEELED;1786return status;1787}17881789static intfiles_peel_ref(struct ref_store *ref_store,1790const char*refname,unsigned char*sha1)1791{1792struct files_ref_store *refs =files_downcast(ref_store,0,"peel_ref");1793int flag;1794unsigned char base[20];17951796if(current_ref_iter && current_ref_iter->refname == refname) {1797struct object_id peeled;17981799if(ref_iterator_peel(current_ref_iter, &peeled))1800return-1;1801hashcpy(sha1, peeled.hash);1802return0;1803}18041805if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1806return-1;18071808/*1809 * If the reference is packed, read its ref_entry from the1810 * cache in the hope that we already know its peeled value.1811 * We only try this optimization on packed references because1812 * (a) forcing the filling of the loose reference cache could1813 * be expensive and (b) loose references anyway usually do not1814 * have REF_KNOWS_PEELED.1815 */1816if(flag & REF_ISPACKED) {1817struct ref_entry *r =get_packed_ref(refs, refname);1818if(r) {1819if(peel_entry(r,0))1820return-1;1821hashcpy(sha1, r->u.value.peeled.hash);1822return0;1823}1824}18251826returnpeel_object(base, sha1);1827}18281829struct files_ref_iterator {1830struct ref_iterator base;18311832struct packed_ref_cache *packed_ref_cache;1833struct ref_iterator *iter0;1834unsigned int flags;1835};18361837static intfiles_ref_iterator_advance(struct ref_iterator *ref_iterator)1838{1839struct files_ref_iterator *iter =1840(struct files_ref_iterator *)ref_iterator;1841int ok;18421843while((ok =ref_iterator_advance(iter->iter0)) == ITER_OK) {1844if(iter->flags & DO_FOR_EACH_PER_WORKTREE_ONLY &&1845ref_type(iter->iter0->refname) != REF_TYPE_PER_WORKTREE)1846continue;18471848if(!(iter->flags & DO_FOR_EACH_INCLUDE_BROKEN) &&1849!ref_resolves_to_object(iter->iter0->refname,1850 iter->iter0->oid,1851 iter->iter0->flags))1852continue;18531854 iter->base.refname = iter->iter0->refname;1855 iter->base.oid = iter->iter0->oid;1856 iter->base.flags = iter->iter0->flags;1857return ITER_OK;1858}18591860 iter->iter0 = NULL;1861if(ref_iterator_abort(ref_iterator) != ITER_DONE)1862 ok = ITER_ERROR;18631864return ok;1865}18661867static intfiles_ref_iterator_peel(struct ref_iterator *ref_iterator,1868struct object_id *peeled)1869{1870struct files_ref_iterator *iter =1871(struct files_ref_iterator *)ref_iterator;18721873returnref_iterator_peel(iter->iter0, peeled);1874}18751876static intfiles_ref_iterator_abort(struct ref_iterator *ref_iterator)1877{1878struct files_ref_iterator *iter =1879(struct files_ref_iterator *)ref_iterator;1880int ok = ITER_DONE;18811882if(iter->iter0)1883 ok =ref_iterator_abort(iter->iter0);18841885release_packed_ref_cache(iter->packed_ref_cache);1886base_ref_iterator_free(ref_iterator);1887return ok;1888}18891890static struct ref_iterator_vtable files_ref_iterator_vtable = {1891 files_ref_iterator_advance,1892 files_ref_iterator_peel,1893 files_ref_iterator_abort1894};18951896static struct ref_iterator *files_ref_iterator_begin(1897struct ref_store *ref_store,1898const char*prefix,unsigned int flags)1899{1900struct files_ref_store *refs =1901files_downcast(ref_store,1,"ref_iterator_begin");1902struct ref_dir *loose_dir, *packed_dir;1903struct ref_iterator *loose_iter, *packed_iter;1904struct files_ref_iterator *iter;1905struct ref_iterator *ref_iterator;19061907if(ref_paranoia <0)1908 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1909if(ref_paranoia)1910 flags |= DO_FOR_EACH_INCLUDE_BROKEN;19111912 iter =xcalloc(1,sizeof(*iter));1913 ref_iterator = &iter->base;1914base_ref_iterator_init(ref_iterator, &files_ref_iterator_vtable);19151916/*1917 * We must make sure that all loose refs are read before1918 * accessing the packed-refs file; this avoids a race1919 * condition if loose refs are migrated to the packed-refs1920 * file by a simultaneous process, but our in-memory view is1921 * from before the migration. We ensure this as follows:1922 * First, we call prime_ref_dir(), which pre-reads the loose1923 * references for the subtree into the cache. (If they've1924 * already been read, that's OK; we only need to guarantee1925 * that they're read before the packed refs, not *how much*1926 * before.) After that, we call get_packed_ref_cache(), which1927 * internally checks whether the packed-ref cache is up to1928 * date with what is on disk, and re-reads it if not.1929 */19301931 loose_dir =get_loose_refs(refs);19321933if(prefix && *prefix)1934 loose_dir =find_containing_dir(loose_dir, prefix,0);19351936if(loose_dir) {1937prime_ref_dir(loose_dir);1938 loose_iter =cache_ref_iterator_begin(loose_dir);1939}else{1940/* There's nothing to iterate over. */1941 loose_iter =empty_ref_iterator_begin();1942}19431944 iter->packed_ref_cache =get_packed_ref_cache(refs);1945acquire_packed_ref_cache(iter->packed_ref_cache);1946 packed_dir =get_packed_ref_dir(iter->packed_ref_cache);19471948if(prefix && *prefix)1949 packed_dir =find_containing_dir(packed_dir, prefix,0);19501951if(packed_dir) {1952 packed_iter =cache_ref_iterator_begin(packed_dir);1953}else{1954/* There's nothing to iterate over. */1955 packed_iter =empty_ref_iterator_begin();1956}19571958 iter->iter0 =overlay_ref_iterator_begin(loose_iter, packed_iter);1959 iter->flags = flags;19601961return ref_iterator;1962}19631964/*1965 * Verify that the reference locked by lock has the value old_sha1.1966 * Fail if the reference doesn't exist and mustexist is set. Return 01967 * on success. On error, write an error message to err, set errno, and1968 * return a negative value.1969 */1970static intverify_lock(struct ref_lock *lock,1971const unsigned char*old_sha1,int mustexist,1972struct strbuf *err)1973{1974assert(err);19751976if(read_ref_full(lock->ref_name,1977 mustexist ? RESOLVE_REF_READING :0,1978 lock->old_oid.hash, NULL)) {1979if(old_sha1) {1980int save_errno = errno;1981strbuf_addf(err,"can't verify ref '%s'", lock->ref_name);1982 errno = save_errno;1983return-1;1984}else{1985oidclr(&lock->old_oid);1986return0;1987}1988}1989if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {1990strbuf_addf(err,"ref '%s' is at%sbut expected%s",1991 lock->ref_name,1992oid_to_hex(&lock->old_oid),1993sha1_to_hex(old_sha1));1994 errno = EBUSY;1995return-1;1996}1997return0;1998}19992000static intremove_empty_directories(struct strbuf *path)2001{2002/*2003 * we want to create a file but there is a directory there;2004 * if that is an empty directory (or a directory that contains2005 * only empty directories), remove them.2006 */2007returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);2008}20092010static intcreate_reflock(const char*path,void*cb)2011{2012struct lock_file *lk = cb;20132014returnhold_lock_file_for_update(lk, path, LOCK_NO_DEREF) <0? -1:0;2015}20162017/*2018 * Locks a ref returning the lock on success and NULL on failure.2019 * On failure errno is set to something meaningful.2020 */2021static struct ref_lock *lock_ref_sha1_basic(struct files_ref_store *refs,2022const char*refname,2023const unsigned char*old_sha1,2024const struct string_list *extras,2025const struct string_list *skip,2026unsigned int flags,int*type,2027struct strbuf *err)2028{2029struct strbuf ref_file = STRBUF_INIT;2030struct ref_lock *lock;2031int last_errno =0;2032int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2033int resolve_flags = RESOLVE_REF_NO_RECURSE;2034int resolved;20352036files_assert_main_repository(refs,"lock_ref_sha1_basic");2037assert(err);20382039 lock =xcalloc(1,sizeof(struct ref_lock));20402041if(mustexist)2042 resolve_flags |= RESOLVE_REF_READING;2043if(flags & REF_DELETING)2044 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;20452046strbuf_git_path(&ref_file,"%s", refname);2047 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2048 lock->old_oid.hash, type);2049if(!resolved && errno == EISDIR) {2050/*2051 * we are trying to lock foo but we used to2052 * have foo/bar which now does not exist;2053 * it is normal for the empty directory 'foo'2054 * to remain.2055 */2056if(remove_empty_directories(&ref_file)) {2057 last_errno = errno;2058if(!verify_refname_available_dir(2059 refname, extras, skip,2060get_loose_refs(refs), err))2061strbuf_addf(err,"there are still refs under '%s'",2062 refname);2063goto error_return;2064}2065 resolved = !!resolve_ref_unsafe(refname, resolve_flags,2066 lock->old_oid.hash, type);2067}2068if(!resolved) {2069 last_errno = errno;2070if(last_errno != ENOTDIR ||2071!verify_refname_available_dir(2072 refname, extras, skip,2073get_loose_refs(refs), err))2074strbuf_addf(err,"unable to resolve reference '%s':%s",2075 refname,strerror(last_errno));20762077goto error_return;2078}20792080/*2081 * If the ref did not exist and we are creating it, make sure2082 * there is no existing packed ref whose name begins with our2083 * refname, nor a packed ref whose name is a proper prefix of2084 * our refname.2085 */2086if(is_null_oid(&lock->old_oid) &&2087verify_refname_available_dir(refname, extras, skip,2088get_packed_refs(refs),2089 err)) {2090 last_errno = ENOTDIR;2091goto error_return;2092}20932094 lock->lk =xcalloc(1,sizeof(struct lock_file));20952096 lock->ref_name =xstrdup(refname);20972098if(raceproof_create_file(ref_file.buf, create_reflock, lock->lk)) {2099 last_errno = errno;2100unable_to_lock_message(ref_file.buf, errno, err);2101goto error_return;2102}21032104if(verify_lock(lock, old_sha1, mustexist, err)) {2105 last_errno = errno;2106goto error_return;2107}2108goto out;21092110 error_return:2111unlock_ref(lock);2112 lock = NULL;21132114 out:2115strbuf_release(&ref_file);2116 errno = last_errno;2117return lock;2118}21192120/*2121 * Write an entry to the packed-refs file for the specified refname.2122 * If peeled is non-NULL, write it as the entry's peeled value.2123 */2124static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2125unsigned char*peeled)2126{2127fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2128if(peeled)2129fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2130}21312132/*2133 * An each_ref_entry_fn that writes the entry to a packed-refs file.2134 */2135static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2136{2137enum peel_status peel_status =peel_entry(entry,0);21382139if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2140error("internal error:%sis not a valid packed reference!",2141 entry->name);2142write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,2143 peel_status == PEEL_PEELED ?2144 entry->u.value.peeled.hash : NULL);2145return0;2146}21472148/*2149 * Lock the packed-refs file for writing. Flags is passed to2150 * hold_lock_file_for_update(). Return 0 on success. On errors, set2151 * errno appropriately and return a nonzero value.2152 */2153static intlock_packed_refs(struct files_ref_store *refs,int flags)2154{2155static int timeout_configured =0;2156static int timeout_value =1000;2157struct packed_ref_cache *packed_ref_cache;21582159files_assert_main_repository(refs,"lock_packed_refs");21602161if(!timeout_configured) {2162git_config_get_int("core.packedrefstimeout", &timeout_value);2163 timeout_configured =1;2164}21652166if(hold_lock_file_for_update_timeout(2167&packlock,files_packed_refs_path(refs),2168 flags, timeout_value) <0)2169return-1;2170/*2171 * Get the current packed-refs while holding the lock. If the2172 * packed-refs file has been modified since we last read it,2173 * this will automatically invalidate the cache and re-read2174 * the packed-refs file.2175 */2176 packed_ref_cache =get_packed_ref_cache(refs);2177 packed_ref_cache->lock = &packlock;2178/* Increment the reference count to prevent it from being freed: */2179acquire_packed_ref_cache(packed_ref_cache);2180return0;2181}21822183/*2184 * Write the current version of the packed refs cache from memory to2185 * disk. The packed-refs file must already be locked for writing (see2186 * lock_packed_refs()). Return zero on success. On errors, set errno2187 * and return a nonzero value2188 */2189static intcommit_packed_refs(struct files_ref_store *refs)2190{2191struct packed_ref_cache *packed_ref_cache =2192get_packed_ref_cache(refs);2193int error =0;2194int save_errno =0;2195FILE*out;21962197files_assert_main_repository(refs,"commit_packed_refs");21982199if(!packed_ref_cache->lock)2200die("internal error: packed-refs not locked");22012202 out =fdopen_lock_file(packed_ref_cache->lock,"w");2203if(!out)2204die_errno("unable to fdopen packed-refs descriptor");22052206fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2207do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),22080, write_packed_entry_fn, out);22092210if(commit_lock_file(packed_ref_cache->lock)) {2211 save_errno = errno;2212 error = -1;2213}2214 packed_ref_cache->lock = NULL;2215release_packed_ref_cache(packed_ref_cache);2216 errno = save_errno;2217return error;2218}22192220/*2221 * Rollback the lockfile for the packed-refs file, and discard the2222 * in-memory packed reference cache. (The packed-refs file will be2223 * read anew if it is needed again after this function is called.)2224 */2225static voidrollback_packed_refs(struct files_ref_store *refs)2226{2227struct packed_ref_cache *packed_ref_cache =2228get_packed_ref_cache(refs);22292230files_assert_main_repository(refs,"rollback_packed_refs");22312232if(!packed_ref_cache->lock)2233die("internal error: packed-refs not locked");2234rollback_lock_file(packed_ref_cache->lock);2235 packed_ref_cache->lock = NULL;2236release_packed_ref_cache(packed_ref_cache);2237clear_packed_ref_cache(refs);2238}22392240struct ref_to_prune {2241struct ref_to_prune *next;2242unsigned char sha1[20];2243char name[FLEX_ARRAY];2244};22452246struct pack_refs_cb_data {2247unsigned int flags;2248struct ref_dir *packed_refs;2249struct ref_to_prune *ref_to_prune;2250};22512252/*2253 * An each_ref_entry_fn that is run over loose references only. If2254 * the loose reference can be packed, add an entry in the packed ref2255 * cache. If the reference should be pruned, also add it to2256 * ref_to_prune in the pack_refs_cb_data.2257 */2258static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2259{2260struct pack_refs_cb_data *cb = cb_data;2261enum peel_status peel_status;2262struct ref_entry *packed_entry;2263int is_tag_ref =starts_with(entry->name,"refs/tags/");22642265/* Do not pack per-worktree refs: */2266if(ref_type(entry->name) != REF_TYPE_NORMAL)2267return0;22682269/* ALWAYS pack tags */2270if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2271return0;22722273/* Do not pack symbolic or broken refs: */2274if((entry->flag & REF_ISSYMREF) || !entry_resolves_to_object(entry))2275return0;22762277/* Add a packed ref cache entry equivalent to the loose entry. */2278 peel_status =peel_entry(entry,1);2279if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2280die("internal error peeling reference%s(%s)",2281 entry->name,oid_to_hex(&entry->u.value.oid));2282 packed_entry =find_ref(cb->packed_refs, entry->name);2283if(packed_entry) {2284/* Overwrite existing packed entry with info from loose entry */2285 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2286oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2287}else{2288 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2289 REF_ISPACKED | REF_KNOWS_PEELED,0);2290add_ref(cb->packed_refs, packed_entry);2291}2292oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);22932294/* Schedule the loose reference for pruning if requested. */2295if((cb->flags & PACK_REFS_PRUNE)) {2296struct ref_to_prune *n;2297FLEX_ALLOC_STR(n, name, entry->name);2298hashcpy(n->sha1, entry->u.value.oid.hash);2299 n->next = cb->ref_to_prune;2300 cb->ref_to_prune = n;2301}2302return0;2303}23042305enum{2306 REMOVE_EMPTY_PARENTS_REF =0x01,2307 REMOVE_EMPTY_PARENTS_REFLOG =0x022308};23092310/*2311 * Remove empty parent directories associated with the specified2312 * reference and/or its reflog, but spare [logs/]refs/ and immediate2313 * subdirs. flags is a combination of REMOVE_EMPTY_PARENTS_REF and/or2314 * REMOVE_EMPTY_PARENTS_REFLOG.2315 */2316static voidtry_remove_empty_parents(const char*refname,unsigned int flags)2317{2318struct strbuf buf = STRBUF_INIT;2319char*p, *q;2320int i;23212322strbuf_addstr(&buf, refname);2323 p = buf.buf;2324for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2325while(*p && *p !='/')2326 p++;2327/* tolerate duplicate slashes; see check_refname_format() */2328while(*p =='/')2329 p++;2330}2331 q = buf.buf + buf.len;2332while(flags & (REMOVE_EMPTY_PARENTS_REF | REMOVE_EMPTY_PARENTS_REFLOG)) {2333while(q > p && *q !='/')2334 q--;2335while(q > p && *(q-1) =='/')2336 q--;2337if(q == p)2338break;2339strbuf_setlen(&buf, q - buf.buf);2340if((flags & REMOVE_EMPTY_PARENTS_REF) &&2341rmdir(git_path("%s", buf.buf)))2342 flags &= ~REMOVE_EMPTY_PARENTS_REF;2343if((flags & REMOVE_EMPTY_PARENTS_REFLOG) &&2344rmdir(git_path("logs/%s", buf.buf)))2345 flags &= ~REMOVE_EMPTY_PARENTS_REFLOG;2346}2347strbuf_release(&buf);2348}23492350/* make sure nobody touched the ref, and unlink */2351static voidprune_ref(struct ref_to_prune *r)2352{2353struct ref_transaction *transaction;2354struct strbuf err = STRBUF_INIT;23552356if(check_refname_format(r->name,0))2357return;23582359 transaction =ref_transaction_begin(&err);2360if(!transaction ||2361ref_transaction_delete(transaction, r->name, r->sha1,2362 REF_ISPRUNING | REF_NODEREF, NULL, &err) ||2363ref_transaction_commit(transaction, &err)) {2364ref_transaction_free(transaction);2365error("%s", err.buf);2366strbuf_release(&err);2367return;2368}2369ref_transaction_free(transaction);2370strbuf_release(&err);2371}23722373static voidprune_refs(struct ref_to_prune *r)2374{2375while(r) {2376prune_ref(r);2377 r = r->next;2378}2379}23802381static intfiles_pack_refs(struct ref_store *ref_store,unsigned int flags)2382{2383struct files_ref_store *refs =2384files_downcast(ref_store,0,"pack_refs");2385struct pack_refs_cb_data cbdata;23862387memset(&cbdata,0,sizeof(cbdata));2388 cbdata.flags = flags;23892390lock_packed_refs(refs, LOCK_DIE_ON_ERROR);2391 cbdata.packed_refs =get_packed_refs(refs);23922393do_for_each_entry_in_dir(get_loose_refs(refs),0,2394 pack_if_possible_fn, &cbdata);23952396if(commit_packed_refs(refs))2397die_errno("unable to overwrite old ref-pack file");23982399prune_refs(cbdata.ref_to_prune);2400return0;2401}24022403/*2404 * Rewrite the packed-refs file, omitting any refs listed in2405 * 'refnames'. On error, leave packed-refs unchanged, write an error2406 * message to 'err', and return a nonzero value.2407 *2408 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2409 */2410static intrepack_without_refs(struct files_ref_store *refs,2411struct string_list *refnames,struct strbuf *err)2412{2413struct ref_dir *packed;2414struct string_list_item *refname;2415int ret, needs_repacking =0, removed =0;24162417files_assert_main_repository(refs,"repack_without_refs");2418assert(err);24192420/* Look for a packed ref */2421for_each_string_list_item(refname, refnames) {2422if(get_packed_ref(refs, refname->string)) {2423 needs_repacking =1;2424break;2425}2426}24272428/* Avoid locking if we have nothing to do */2429if(!needs_repacking)2430return0;/* no refname exists in packed refs */24312432if(lock_packed_refs(refs,0)) {2433unable_to_lock_message(files_packed_refs_path(refs), errno, err);2434return-1;2435}2436 packed =get_packed_refs(refs);24372438/* Remove refnames from the cache */2439for_each_string_list_item(refname, refnames)2440if(remove_entry(packed, refname->string) != -1)2441 removed =1;2442if(!removed) {2443/*2444 * All packed entries disappeared while we were2445 * acquiring the lock.2446 */2447rollback_packed_refs(refs);2448return0;2449}24502451/* Write what remains */2452 ret =commit_packed_refs(refs);2453if(ret)2454strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2455strerror(errno));2456return ret;2457}24582459static intfiles_delete_refs(struct ref_store *ref_store,2460struct string_list *refnames,unsigned int flags)2461{2462struct files_ref_store *refs =2463files_downcast(ref_store,0,"delete_refs");2464struct strbuf err = STRBUF_INIT;2465int i, result =0;24662467if(!refnames->nr)2468return0;24692470 result =repack_without_refs(refs, refnames, &err);2471if(result) {2472/*2473 * If we failed to rewrite the packed-refs file, then2474 * it is unsafe to try to remove loose refs, because2475 * doing so might expose an obsolete packed value for2476 * a reference that might even point at an object that2477 * has been garbage collected.2478 */2479if(refnames->nr ==1)2480error(_("could not delete reference%s:%s"),2481 refnames->items[0].string, err.buf);2482else2483error(_("could not delete references:%s"), err.buf);24842485goto out;2486}24872488for(i =0; i < refnames->nr; i++) {2489const char*refname = refnames->items[i].string;24902491if(delete_ref(NULL, refname, NULL, flags))2492 result |=error(_("could not remove reference%s"), refname);2493}24942495out:2496strbuf_release(&err);2497return result;2498}24992500/*2501 * People using contrib's git-new-workdir have .git/logs/refs ->2502 * /some/other/path/.git/logs/refs, and that may live on another device.2503 *2504 * IOW, to avoid cross device rename errors, the temporary renamed log must2505 * live into logs/refs.2506 */2507#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"25082509static intrename_tmp_log_callback(const char*path,void*cb)2510{2511int*true_errno = cb;25122513if(rename(git_path(TMP_RENAMED_LOG), path)) {2514/*2515 * rename(a, b) when b is an existing directory ought2516 * to result in ISDIR, but Solaris 5.8 gives ENOTDIR.2517 * Sheesh. Record the true errno for error reporting,2518 * but report EISDIR to raceproof_create_file() so2519 * that it knows to retry.2520 */2521*true_errno = errno;2522if(errno == ENOTDIR)2523 errno = EISDIR;2524return-1;2525}else{2526return0;2527}2528}25292530static intrename_tmp_log(const char*newrefname)2531{2532char*path =git_pathdup("logs/%s", newrefname);2533int ret, true_errno;25342535 ret =raceproof_create_file(path, rename_tmp_log_callback, &true_errno);2536if(ret) {2537if(errno == EISDIR)2538error("directory not empty:%s", path);2539else2540error("unable to move logfile%sto%s:%s",2541git_path(TMP_RENAMED_LOG), path,2542strerror(true_errno));2543}25442545free(path);2546return ret;2547}25482549static intfiles_verify_refname_available(struct ref_store *ref_store,2550const char*newname,2551const struct string_list *extras,2552const struct string_list *skip,2553struct strbuf *err)2554{2555struct files_ref_store *refs =2556files_downcast(ref_store,1,"verify_refname_available");2557struct ref_dir *packed_refs =get_packed_refs(refs);2558struct ref_dir *loose_refs =get_loose_refs(refs);25592560if(verify_refname_available_dir(newname, extras, skip,2561 packed_refs, err) ||2562verify_refname_available_dir(newname, extras, skip,2563 loose_refs, err))2564return-1;25652566return0;2567}25682569static intwrite_ref_to_lockfile(struct ref_lock *lock,2570const unsigned char*sha1,struct strbuf *err);2571static intcommit_ref_update(struct files_ref_store *refs,2572struct ref_lock *lock,2573const unsigned char*sha1,const char*logmsg,2574struct strbuf *err);25752576static intfiles_rename_ref(struct ref_store *ref_store,2577const char*oldrefname,const char*newrefname,2578const char*logmsg)2579{2580struct files_ref_store *refs =2581files_downcast(ref_store,0,"rename_ref");2582unsigned char sha1[20], orig_sha1[20];2583int flag =0, logmoved =0;2584struct ref_lock *lock;2585struct stat loginfo;2586int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2587struct strbuf err = STRBUF_INIT;2588int ret;25892590if(log &&S_ISLNK(loginfo.st_mode)) {2591 ret =error("reflog for%sis a symlink", oldrefname);2592goto out;2593}25942595if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2596 orig_sha1, &flag)) {2597 ret =error("refname%snot found", oldrefname);2598goto out;2599}26002601if(flag & REF_ISSYMREF) {2602 ret =error("refname%sis a symbolic ref, renaming it is not supported",2603 oldrefname);2604goto out;2605}2606if(!rename_ref_available(oldrefname, newrefname)) {2607 ret =1;2608goto out;2609}26102611if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG))) {2612 ret =error("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2613 oldrefname,strerror(errno));2614goto out;2615}26162617if(delete_ref(logmsg, oldrefname, orig_sha1, REF_NODEREF)) {2618error("unable to delete old%s", oldrefname);2619goto rollback;2620}26212622/*2623 * Since we are doing a shallow lookup, sha1 is not the2624 * correct value to pass to delete_ref as old_sha1. But that2625 * doesn't matter, because an old_sha1 check wouldn't add to2626 * the safety anyway; we want to delete the reference whatever2627 * its current value.2628 */2629if(!read_ref_full(newrefname, RESOLVE_REF_READING | RESOLVE_REF_NO_RECURSE,2630 sha1, NULL) &&2631delete_ref(NULL, newrefname, NULL, REF_NODEREF)) {2632if(errno == EISDIR) {2633struct strbuf path = STRBUF_INIT;2634int result;26352636strbuf_git_path(&path,"%s", newrefname);2637 result =remove_empty_directories(&path);2638strbuf_release(&path);26392640if(result) {2641error("Directory not empty:%s", newrefname);2642goto rollback;2643}2644}else{2645error("unable to delete existing%s", newrefname);2646goto rollback;2647}2648}26492650if(log &&rename_tmp_log(newrefname))2651goto rollback;26522653 logmoved = log;26542655 lock =lock_ref_sha1_basic(refs, newrefname, NULL, NULL, NULL,2656 REF_NODEREF, NULL, &err);2657if(!lock) {2658error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2659strbuf_release(&err);2660goto rollback;2661}2662hashcpy(lock->old_oid.hash, orig_sha1);26632664if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2665commit_ref_update(refs, lock, orig_sha1, logmsg, &err)) {2666error("unable to write current sha1 into%s:%s", newrefname, err.buf);2667strbuf_release(&err);2668goto rollback;2669}26702671 ret =0;2672goto out;26732674 rollback:2675 lock =lock_ref_sha1_basic(refs, oldrefname, NULL, NULL, NULL,2676 REF_NODEREF, NULL, &err);2677if(!lock) {2678error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2679strbuf_release(&err);2680goto rollbacklog;2681}26822683 flag = log_all_ref_updates;2684 log_all_ref_updates = LOG_REFS_NONE;2685if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2686commit_ref_update(refs, lock, orig_sha1, NULL, &err)) {2687error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2688strbuf_release(&err);2689}2690 log_all_ref_updates = flag;26912692 rollbacklog:2693if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2694error("unable to restore logfile%sfrom%s:%s",2695 oldrefname, newrefname,strerror(errno));2696if(!logmoved && log &&2697rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2698error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2699 oldrefname,strerror(errno));27002701 ret =1;2702 out:2703return ret;2704}27052706static intclose_ref(struct ref_lock *lock)2707{2708if(close_lock_file(lock->lk))2709return-1;2710return0;2711}27122713static intcommit_ref(struct ref_lock *lock)2714{2715char*path =get_locked_file_path(lock->lk);2716struct stat st;27172718if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2719/*2720 * There is a directory at the path we want to rename2721 * the lockfile to. Hopefully it is empty; try to2722 * delete it.2723 */2724size_t len =strlen(path);2725struct strbuf sb_path = STRBUF_INIT;27262727strbuf_attach(&sb_path, path, len, len);27282729/*2730 * If this fails, commit_lock_file() will also fail2731 * and will report the problem.2732 */2733remove_empty_directories(&sb_path);2734strbuf_release(&sb_path);2735}else{2736free(path);2737}27382739if(commit_lock_file(lock->lk))2740return-1;2741return0;2742}27432744static intopen_or_create_logfile(const char*path,void*cb)2745{2746int*fd = cb;27472748*fd =open(path, O_APPEND | O_WRONLY | O_CREAT,0666);2749return(*fd <0) ? -1:0;2750}27512752/*2753 * Create a reflog for a ref. If force_create = 0, only create the2754 * reflog for certain refs (those for which should_autocreate_reflog2755 * returns non-zero). Otherwise, create it regardless of the reference2756 * name. If the logfile already existed or was created, return 0 and2757 * set *logfd to the file descriptor opened for appending to the file.2758 * If no logfile exists and we decided not to create one, return 0 and2759 * set *logfd to -1. On failure, fill in *err, set *logfd to -1, and2760 * return -1.2761 */2762static intlog_ref_setup(const char*refname,int force_create,2763int*logfd,struct strbuf *err)2764{2765char*logfile =git_pathdup("logs/%s", refname);27662767if(force_create ||should_autocreate_reflog(refname)) {2768if(raceproof_create_file(logfile, open_or_create_logfile, logfd)) {2769if(errno == ENOENT)2770strbuf_addf(err,"unable to create directory for '%s': "2771"%s", logfile,strerror(errno));2772else if(errno == EISDIR)2773strbuf_addf(err,"there are still logs under '%s'",2774 logfile);2775else2776strbuf_addf(err,"unable to append to '%s':%s",2777 logfile,strerror(errno));27782779goto error;2780}2781}else{2782*logfd =open(logfile, O_APPEND | O_WRONLY,0666);2783if(*logfd <0) {2784if(errno == ENOENT || errno == EISDIR) {2785/*2786 * The logfile doesn't already exist,2787 * but that is not an error; it only2788 * means that we won't write log2789 * entries to it.2790 */2791;2792}else{2793strbuf_addf(err,"unable to append to '%s':%s",2794 logfile,strerror(errno));2795goto error;2796}2797}2798}27992800if(*logfd >=0)2801adjust_shared_perm(logfile);28022803free(logfile);2804return0;28052806error:2807free(logfile);2808return-1;2809}28102811static intfiles_create_reflog(struct ref_store *ref_store,2812const char*refname,int force_create,2813struct strbuf *err)2814{2815int fd;28162817/* Check validity (but we don't need the result): */2818files_downcast(ref_store,0,"create_reflog");28192820if(log_ref_setup(refname, force_create, &fd, err))2821return-1;28222823if(fd >=0)2824close(fd);28252826return0;2827}28282829static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2830const unsigned char*new_sha1,2831const char*committer,const char*msg)2832{2833int msglen, written;2834unsigned maxlen, len;2835char*logrec;28362837 msglen = msg ?strlen(msg) :0;2838 maxlen =strlen(committer) + msglen +100;2839 logrec =xmalloc(maxlen);2840 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2841sha1_to_hex(old_sha1),2842sha1_to_hex(new_sha1),2843 committer);2844if(msglen)2845 len +=copy_reflog_msg(logrec + len -1, msg) -1;28462847 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2848free(logrec);2849if(written != len)2850return-1;28512852return0;2853}28542855static intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1,2856const unsigned char*new_sha1,const char*msg,2857int flags,struct strbuf *err)2858{2859int logfd, result;28602861if(log_all_ref_updates == LOG_REFS_UNSET)2862 log_all_ref_updates =is_bare_repository() ? LOG_REFS_NONE : LOG_REFS_NORMAL;28632864 result =log_ref_setup(refname, flags & REF_FORCE_CREATE_REFLOG,2865&logfd, err);28662867if(result)2868return result;28692870if(logfd <0)2871return0;2872 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2873git_committer_info(0), msg);2874if(result) {2875int save_errno = errno;28762877strbuf_addf(err,"unable to append to '%s':%s",2878git_path("logs/%s", refname),strerror(save_errno));2879close(logfd);2880return-1;2881}2882if(close(logfd)) {2883int save_errno = errno;28842885strbuf_addf(err,"unable to append to '%s':%s",2886git_path("logs/%s", refname),strerror(save_errno));2887return-1;2888}2889return0;2890}28912892/*2893 * Write sha1 into the open lockfile, then close the lockfile. On2894 * errors, rollback the lockfile, fill in *err and2895 * return -1.2896 */2897static intwrite_ref_to_lockfile(struct ref_lock *lock,2898const unsigned char*sha1,struct strbuf *err)2899{2900static char term ='\n';2901struct object *o;2902int fd;29032904 o =parse_object(sha1);2905if(!o) {2906strbuf_addf(err,2907"trying to write ref '%s' with nonexistent object%s",2908 lock->ref_name,sha1_to_hex(sha1));2909unlock_ref(lock);2910return-1;2911}2912if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2913strbuf_addf(err,2914"trying to write non-commit object%sto branch '%s'",2915sha1_to_hex(sha1), lock->ref_name);2916unlock_ref(lock);2917return-1;2918}2919 fd =get_lock_file_fd(lock->lk);2920if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2921write_in_full(fd, &term,1) !=1||2922close_ref(lock) <0) {2923strbuf_addf(err,2924"couldn't write '%s'",get_lock_file_path(lock->lk));2925unlock_ref(lock);2926return-1;2927}2928return0;2929}29302931/*2932 * Commit a change to a loose reference that has already been written2933 * to the loose reference lockfile. Also update the reflogs if2934 * necessary, using the specified lockmsg (which can be NULL).2935 */2936static intcommit_ref_update(struct files_ref_store *refs,2937struct ref_lock *lock,2938const unsigned char*sha1,const char*logmsg,2939struct strbuf *err)2940{2941files_assert_main_repository(refs,"commit_ref_update");29422943clear_loose_ref_cache(refs);2944if(files_log_ref_write(lock->ref_name, lock->old_oid.hash, sha1,2945 logmsg,0, err)) {2946char*old_msg =strbuf_detach(err, NULL);2947strbuf_addf(err,"cannot update the ref '%s':%s",2948 lock->ref_name, old_msg);2949free(old_msg);2950unlock_ref(lock);2951return-1;2952}29532954if(strcmp(lock->ref_name,"HEAD") !=0) {2955/*2956 * Special hack: If a branch is updated directly and HEAD2957 * points to it (may happen on the remote side of a push2958 * for example) then logically the HEAD reflog should be2959 * updated too.2960 * A generic solution implies reverse symref information,2961 * but finding all symrefs pointing to the given branch2962 * would be rather costly for this rare event (the direct2963 * update of a branch) to be worth it. So let's cheat and2964 * check with HEAD only which should cover 99% of all usage2965 * scenarios (even 100% of the default ones).2966 */2967unsigned char head_sha1[20];2968int head_flag;2969const char*head_ref;29702971 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2972 head_sha1, &head_flag);2973if(head_ref && (head_flag & REF_ISSYMREF) &&2974!strcmp(head_ref, lock->ref_name)) {2975struct strbuf log_err = STRBUF_INIT;2976if(files_log_ref_write("HEAD", lock->old_oid.hash, sha1,2977 logmsg,0, &log_err)) {2978error("%s", log_err.buf);2979strbuf_release(&log_err);2980}2981}2982}29832984if(commit_ref(lock)) {2985strbuf_addf(err,"couldn't set '%s'", lock->ref_name);2986unlock_ref(lock);2987return-1;2988}29892990unlock_ref(lock);2991return0;2992}29932994static intcreate_ref_symlink(struct ref_lock *lock,const char*target)2995{2996int ret = -1;2997#ifndef NO_SYMLINK_HEAD2998char*ref_path =get_locked_file_path(lock->lk);2999unlink(ref_path);3000 ret =symlink(target, ref_path);3001free(ref_path);30023003if(ret)3004fprintf(stderr,"no symlink - falling back to symbolic ref\n");3005#endif3006return ret;3007}30083009static voidupdate_symref_reflog(struct ref_lock *lock,const char*refname,3010const char*target,const char*logmsg)3011{3012struct strbuf err = STRBUF_INIT;3013unsigned char new_sha1[20];3014if(logmsg && !read_ref(target, new_sha1) &&3015files_log_ref_write(refname, lock->old_oid.hash, new_sha1,3016 logmsg,0, &err)) {3017error("%s", err.buf);3018strbuf_release(&err);3019}3020}30213022static intcreate_symref_locked(struct ref_lock *lock,const char*refname,3023const char*target,const char*logmsg)3024{3025if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {3026update_symref_reflog(lock, refname, target, logmsg);3027return0;3028}30293030if(!fdopen_lock_file(lock->lk,"w"))3031returnerror("unable to fdopen%s:%s",3032 lock->lk->tempfile.filename.buf,strerror(errno));30333034update_symref_reflog(lock, refname, target, logmsg);30353036/* no error check; commit_ref will check ferror */3037fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);3038if(commit_ref(lock) <0)3039returnerror("unable to write symref for%s:%s", refname,3040strerror(errno));3041return0;3042}30433044static intfiles_create_symref(struct ref_store *ref_store,3045const char*refname,const char*target,3046const char*logmsg)3047{3048struct files_ref_store *refs =3049files_downcast(ref_store,0,"create_symref");3050struct strbuf err = STRBUF_INIT;3051struct ref_lock *lock;3052int ret;30533054 lock =lock_ref_sha1_basic(refs, refname, NULL,3055 NULL, NULL, REF_NODEREF, NULL,3056&err);3057if(!lock) {3058error("%s", err.buf);3059strbuf_release(&err);3060return-1;3061}30623063 ret =create_symref_locked(lock, refname, target, logmsg);3064unlock_ref(lock);3065return ret;3066}30673068intset_worktree_head_symref(const char*gitdir,const char*target,const char*logmsg)3069{3070static struct lock_file head_lock;3071struct ref_lock *lock;3072struct strbuf head_path = STRBUF_INIT;3073const char*head_rel;3074int ret;30753076strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));3077if(hold_lock_file_for_update(&head_lock, head_path.buf,3078 LOCK_NO_DEREF) <0) {3079struct strbuf err = STRBUF_INIT;3080unable_to_lock_message(head_path.buf, errno, &err);3081error("%s", err.buf);3082strbuf_release(&err);3083strbuf_release(&head_path);3084return-1;3085}30863087/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for3088 linked trees */3089 head_rel =remove_leading_path(head_path.buf,3090absolute_path(get_git_common_dir()));3091/* to make use of create_symref_locked(), initialize ref_lock */3092 lock =xcalloc(1,sizeof(struct ref_lock));3093 lock->lk = &head_lock;3094 lock->ref_name =xstrdup(head_rel);30953096 ret =create_symref_locked(lock, head_rel, target, logmsg);30973098unlock_ref(lock);/* will free lock */3099strbuf_release(&head_path);3100return ret;3101}31023103static intfiles_reflog_exists(struct ref_store *ref_store,3104const char*refname)3105{3106struct stat st;31073108/* Check validity (but we don't need the result): */3109files_downcast(ref_store,0,"reflog_exists");31103111return!lstat(git_path("logs/%s", refname), &st) &&3112S_ISREG(st.st_mode);3113}31143115static intfiles_delete_reflog(struct ref_store *ref_store,3116const char*refname)3117{3118/* Check validity (but we don't need the result): */3119files_downcast(ref_store,0,"delete_reflog");31203121returnremove_path(git_path("logs/%s", refname));3122}31233124static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3125{3126struct object_id ooid, noid;3127char*email_end, *message;3128unsigned long timestamp;3129int tz;3130const char*p = sb->buf;31313132/* old SP new SP name <email> SP time TAB msg LF */3133if(!sb->len || sb->buf[sb->len -1] !='\n'||3134parse_oid_hex(p, &ooid, &p) || *p++ !=' '||3135parse_oid_hex(p, &noid, &p) || *p++ !=' '||3136!(email_end =strchr(p,'>')) ||3137 email_end[1] !=' '||3138!(timestamp =strtoul(email_end +2, &message,10)) ||3139!message || message[0] !=' '||3140(message[1] !='+'&& message[1] !='-') ||3141!isdigit(message[2]) || !isdigit(message[3]) ||3142!isdigit(message[4]) || !isdigit(message[5]))3143return0;/* corrupt? */3144 email_end[1] ='\0';3145 tz =strtol(message +1, NULL,10);3146if(message[6] !='\t')3147 message +=6;3148else3149 message +=7;3150returnfn(&ooid, &noid, p, timestamp, tz, message, cb_data);3151}31523153static char*find_beginning_of_line(char*bob,char*scan)3154{3155while(bob < scan && *(--scan) !='\n')3156;/* keep scanning backwards */3157/*3158 * Return either beginning of the buffer, or LF at the end of3159 * the previous line.3160 */3161return scan;3162}31633164static intfiles_for_each_reflog_ent_reverse(struct ref_store *ref_store,3165const char*refname,3166 each_reflog_ent_fn fn,3167void*cb_data)3168{3169struct strbuf sb = STRBUF_INIT;3170FILE*logfp;3171long pos;3172int ret =0, at_tail =1;31733174/* Check validity (but we don't need the result): */3175files_downcast(ref_store,0,"for_each_reflog_ent_reverse");31763177 logfp =fopen(git_path("logs/%s", refname),"r");3178if(!logfp)3179return-1;31803181/* Jump to the end */3182if(fseek(logfp,0, SEEK_END) <0)3183returnerror("cannot seek back reflog for%s:%s",3184 refname,strerror(errno));3185 pos =ftell(logfp);3186while(!ret &&0< pos) {3187int cnt;3188size_t nread;3189char buf[BUFSIZ];3190char*endp, *scanp;31913192/* Fill next block from the end */3193 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3194if(fseek(logfp, pos - cnt, SEEK_SET))3195returnerror("cannot seek back reflog for%s:%s",3196 refname,strerror(errno));3197 nread =fread(buf, cnt,1, logfp);3198if(nread !=1)3199returnerror("cannot read%dbytes from reflog for%s:%s",3200 cnt, refname,strerror(errno));3201 pos -= cnt;32023203 scanp = endp = buf + cnt;3204if(at_tail && scanp[-1] =='\n')3205/* Looking at the final LF at the end of the file */3206 scanp--;3207 at_tail =0;32083209while(buf < scanp) {3210/*3211 * terminating LF of the previous line, or the beginning3212 * of the buffer.3213 */3214char*bp;32153216 bp =find_beginning_of_line(buf, scanp);32173218if(*bp =='\n') {3219/*3220 * The newline is the end of the previous line,3221 * so we know we have complete line starting3222 * at (bp + 1). Prefix it onto any prior data3223 * we collected for the line and process it.3224 */3225strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3226 scanp = bp;3227 endp = bp +1;3228 ret =show_one_reflog_ent(&sb, fn, cb_data);3229strbuf_reset(&sb);3230if(ret)3231break;3232}else if(!pos) {3233/*3234 * We are at the start of the buffer, and the3235 * start of the file; there is no previous3236 * line, and we have everything for this one.3237 * Process it, and we can end the loop.3238 */3239strbuf_splice(&sb,0,0, buf, endp - buf);3240 ret =show_one_reflog_ent(&sb, fn, cb_data);3241strbuf_reset(&sb);3242break;3243}32443245if(bp == buf) {3246/*3247 * We are at the start of the buffer, and there3248 * is more file to read backwards. Which means3249 * we are in the middle of a line. Note that we3250 * may get here even if *bp was a newline; that3251 * just means we are at the exact end of the3252 * previous line, rather than some spot in the3253 * middle.3254 *3255 * Save away what we have to be combined with3256 * the data from the next read.3257 */3258strbuf_splice(&sb,0,0, buf, endp - buf);3259break;3260}3261}32623263}3264if(!ret && sb.len)3265die("BUG: reverse reflog parser had leftover data");32663267fclose(logfp);3268strbuf_release(&sb);3269return ret;3270}32713272static intfiles_for_each_reflog_ent(struct ref_store *ref_store,3273const char*refname,3274 each_reflog_ent_fn fn,void*cb_data)3275{3276FILE*logfp;3277struct strbuf sb = STRBUF_INIT;3278int ret =0;32793280/* Check validity (but we don't need the result): */3281files_downcast(ref_store,0,"for_each_reflog_ent");32823283 logfp =fopen(git_path("logs/%s", refname),"r");3284if(!logfp)3285return-1;32863287while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3288 ret =show_one_reflog_ent(&sb, fn, cb_data);3289fclose(logfp);3290strbuf_release(&sb);3291return ret;3292}32933294struct files_reflog_iterator {3295struct ref_iterator base;32963297struct dir_iterator *dir_iterator;3298struct object_id oid;3299};33003301static intfiles_reflog_iterator_advance(struct ref_iterator *ref_iterator)3302{3303struct files_reflog_iterator *iter =3304(struct files_reflog_iterator *)ref_iterator;3305struct dir_iterator *diter = iter->dir_iterator;3306int ok;33073308while((ok =dir_iterator_advance(diter)) == ITER_OK) {3309int flags;33103311if(!S_ISREG(diter->st.st_mode))3312continue;3313if(diter->basename[0] =='.')3314continue;3315if(ends_with(diter->basename,".lock"))3316continue;33173318if(read_ref_full(diter->relative_path,0,3319 iter->oid.hash, &flags)) {3320error("bad ref for%s", diter->path.buf);3321continue;3322}33233324 iter->base.refname = diter->relative_path;3325 iter->base.oid = &iter->oid;3326 iter->base.flags = flags;3327return ITER_OK;3328}33293330 iter->dir_iterator = NULL;3331if(ref_iterator_abort(ref_iterator) == ITER_ERROR)3332 ok = ITER_ERROR;3333return ok;3334}33353336static intfiles_reflog_iterator_peel(struct ref_iterator *ref_iterator,3337struct object_id *peeled)3338{3339die("BUG: ref_iterator_peel() called for reflog_iterator");3340}33413342static intfiles_reflog_iterator_abort(struct ref_iterator *ref_iterator)3343{3344struct files_reflog_iterator *iter =3345(struct files_reflog_iterator *)ref_iterator;3346int ok = ITER_DONE;33473348if(iter->dir_iterator)3349 ok =dir_iterator_abort(iter->dir_iterator);33503351base_ref_iterator_free(ref_iterator);3352return ok;3353}33543355static struct ref_iterator_vtable files_reflog_iterator_vtable = {3356 files_reflog_iterator_advance,3357 files_reflog_iterator_peel,3358 files_reflog_iterator_abort3359};33603361static struct ref_iterator *files_reflog_iterator_begin(struct ref_store *ref_store)3362{3363struct files_reflog_iterator *iter =xcalloc(1,sizeof(*iter));3364struct ref_iterator *ref_iterator = &iter->base;33653366/* Check validity (but we don't need the result): */3367files_downcast(ref_store,0,"reflog_iterator_begin");33683369base_ref_iterator_init(ref_iterator, &files_reflog_iterator_vtable);3370 iter->dir_iterator =dir_iterator_begin(git_path("logs"));3371return ref_iterator;3372}33733374static intref_update_reject_duplicates(struct string_list *refnames,3375struct strbuf *err)3376{3377int i, n = refnames->nr;33783379assert(err);33803381for(i =1; i < n; i++)3382if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3383strbuf_addf(err,3384"multiple updates for ref '%s' not allowed.",3385 refnames->items[i].string);3386return1;3387}3388return0;3389}33903391/*3392 * If update is a direct update of head_ref (the reference pointed to3393 * by HEAD), then add an extra REF_LOG_ONLY update for HEAD.3394 */3395static intsplit_head_update(struct ref_update *update,3396struct ref_transaction *transaction,3397const char*head_ref,3398struct string_list *affected_refnames,3399struct strbuf *err)3400{3401struct string_list_item *item;3402struct ref_update *new_update;34033404if((update->flags & REF_LOG_ONLY) ||3405(update->flags & REF_ISPRUNING) ||3406(update->flags & REF_UPDATE_VIA_HEAD))3407return0;34083409if(strcmp(update->refname, head_ref))3410return0;34113412/*3413 * First make sure that HEAD is not already in the3414 * transaction. This insertion is O(N) in the transaction3415 * size, but it happens at most once per transaction.3416 */3417 item =string_list_insert(affected_refnames,"HEAD");3418if(item->util) {3419/* An entry already existed */3420strbuf_addf(err,3421"multiple updates for 'HEAD' (including one "3422"via its referent '%s') are not allowed",3423 update->refname);3424return TRANSACTION_NAME_CONFLICT;3425}34263427 new_update =ref_transaction_add_update(3428 transaction,"HEAD",3429 update->flags | REF_LOG_ONLY | REF_NODEREF,3430 update->new_sha1, update->old_sha1,3431 update->msg);34323433 item->util = new_update;34343435return0;3436}34373438/*3439 * update is for a symref that points at referent and doesn't have3440 * REF_NODEREF set. Split it into two updates:3441 * - The original update, but with REF_LOG_ONLY and REF_NODEREF set3442 * - A new, separate update for the referent reference3443 * Note that the new update will itself be subject to splitting when3444 * the iteration gets to it.3445 */3446static intsplit_symref_update(struct files_ref_store *refs,3447struct ref_update *update,3448const char*referent,3449struct ref_transaction *transaction,3450struct string_list *affected_refnames,3451struct strbuf *err)3452{3453struct string_list_item *item;3454struct ref_update *new_update;3455unsigned int new_flags;34563457/*3458 * First make sure that referent is not already in the3459 * transaction. This insertion is O(N) in the transaction3460 * size, but it happens at most once per symref in a3461 * transaction.3462 */3463 item =string_list_insert(affected_refnames, referent);3464if(item->util) {3465/* An entry already existed */3466strbuf_addf(err,3467"multiple updates for '%s' (including one "3468"via symref '%s') are not allowed",3469 referent, update->refname);3470return TRANSACTION_NAME_CONFLICT;3471}34723473 new_flags = update->flags;3474if(!strcmp(update->refname,"HEAD")) {3475/*3476 * Record that the new update came via HEAD, so that3477 * when we process it, split_head_update() doesn't try3478 * to add another reflog update for HEAD. Note that3479 * this bit will be propagated if the new_update3480 * itself needs to be split.3481 */3482 new_flags |= REF_UPDATE_VIA_HEAD;3483}34843485 new_update =ref_transaction_add_update(3486 transaction, referent, new_flags,3487 update->new_sha1, update->old_sha1,3488 update->msg);34893490 new_update->parent_update = update;34913492/*3493 * Change the symbolic ref update to log only. Also, it3494 * doesn't need to check its old SHA-1 value, as that will be3495 * done when new_update is processed.3496 */3497 update->flags |= REF_LOG_ONLY | REF_NODEREF;3498 update->flags &= ~REF_HAVE_OLD;34993500 item->util = new_update;35013502return0;3503}35043505/*3506 * Return the refname under which update was originally requested.3507 */3508static const char*original_update_refname(struct ref_update *update)3509{3510while(update->parent_update)3511 update = update->parent_update;35123513return update->refname;3514}35153516/*3517 * Check whether the REF_HAVE_OLD and old_oid values stored in update3518 * are consistent with oid, which is the reference's current value. If3519 * everything is OK, return 0; otherwise, write an error message to3520 * err and return -1.3521 */3522static intcheck_old_oid(struct ref_update *update,struct object_id *oid,3523struct strbuf *err)3524{3525if(!(update->flags & REF_HAVE_OLD) ||3526!hashcmp(oid->hash, update->old_sha1))3527return0;35283529if(is_null_sha1(update->old_sha1))3530strbuf_addf(err,"cannot lock ref '%s': "3531"reference already exists",3532original_update_refname(update));3533else if(is_null_oid(oid))3534strbuf_addf(err,"cannot lock ref '%s': "3535"reference is missing but expected%s",3536original_update_refname(update),3537sha1_to_hex(update->old_sha1));3538else3539strbuf_addf(err,"cannot lock ref '%s': "3540"is at%sbut expected%s",3541original_update_refname(update),3542oid_to_hex(oid),3543sha1_to_hex(update->old_sha1));35443545return-1;3546}35473548/*3549 * Prepare for carrying out update:3550 * - Lock the reference referred to by update.3551 * - Read the reference under lock.3552 * - Check that its old SHA-1 value (if specified) is correct, and in3553 * any case record it in update->lock->old_oid for later use when3554 * writing the reflog.3555 * - If it is a symref update without REF_NODEREF, split it up into a3556 * REF_LOG_ONLY update of the symref and add a separate update for3557 * the referent to transaction.3558 * - If it is an update of head_ref, add a corresponding REF_LOG_ONLY3559 * update of HEAD.3560 */3561static intlock_ref_for_update(struct files_ref_store *refs,3562struct ref_update *update,3563struct ref_transaction *transaction,3564const char*head_ref,3565struct string_list *affected_refnames,3566struct strbuf *err)3567{3568struct strbuf referent = STRBUF_INIT;3569int mustexist = (update->flags & REF_HAVE_OLD) &&3570!is_null_sha1(update->old_sha1);3571int ret;3572struct ref_lock *lock;35733574files_assert_main_repository(refs,"lock_ref_for_update");35753576if((update->flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3577 update->flags |= REF_DELETING;35783579if(head_ref) {3580 ret =split_head_update(update, transaction, head_ref,3581 affected_refnames, err);3582if(ret)3583return ret;3584}35853586 ret =lock_raw_ref(refs, update->refname, mustexist,3587 affected_refnames, NULL,3588&lock, &referent,3589&update->type, err);3590if(ret) {3591char*reason;35923593 reason =strbuf_detach(err, NULL);3594strbuf_addf(err,"cannot lock ref '%s':%s",3595original_update_refname(update), reason);3596free(reason);3597return ret;3598}35993600 update->backend_data = lock;36013602if(update->type & REF_ISSYMREF) {3603if(update->flags & REF_NODEREF) {3604/*3605 * We won't be reading the referent as part of3606 * the transaction, so we have to read it here3607 * to record and possibly check old_sha1:3608 */3609if(read_ref_full(referent.buf,0,3610 lock->old_oid.hash, NULL)) {3611if(update->flags & REF_HAVE_OLD) {3612strbuf_addf(err,"cannot lock ref '%s': "3613"error reading reference",3614original_update_refname(update));3615return-1;3616}3617}else if(check_old_oid(update, &lock->old_oid, err)) {3618return TRANSACTION_GENERIC_ERROR;3619}3620}else{3621/*3622 * Create a new update for the reference this3623 * symref is pointing at. Also, we will record3624 * and verify old_sha1 for this update as part3625 * of processing the split-off update, so we3626 * don't have to do it here.3627 */3628 ret =split_symref_update(refs, update,3629 referent.buf, transaction,3630 affected_refnames, err);3631if(ret)3632return ret;3633}3634}else{3635struct ref_update *parent_update;36363637if(check_old_oid(update, &lock->old_oid, err))3638return TRANSACTION_GENERIC_ERROR;36393640/*3641 * If this update is happening indirectly because of a3642 * symref update, record the old SHA-1 in the parent3643 * update:3644 */3645for(parent_update = update->parent_update;3646 parent_update;3647 parent_update = parent_update->parent_update) {3648struct ref_lock *parent_lock = parent_update->backend_data;3649oidcpy(&parent_lock->old_oid, &lock->old_oid);3650}3651}36523653if((update->flags & REF_HAVE_NEW) &&3654!(update->flags & REF_DELETING) &&3655!(update->flags & REF_LOG_ONLY)) {3656if(!(update->type & REF_ISSYMREF) &&3657!hashcmp(lock->old_oid.hash, update->new_sha1)) {3658/*3659 * The reference already has the desired3660 * value, so we don't need to write it.3661 */3662}else if(write_ref_to_lockfile(lock, update->new_sha1,3663 err)) {3664char*write_err =strbuf_detach(err, NULL);36653666/*3667 * The lock was freed upon failure of3668 * write_ref_to_lockfile():3669 */3670 update->backend_data = NULL;3671strbuf_addf(err,3672"cannot update ref '%s':%s",3673 update->refname, write_err);3674free(write_err);3675return TRANSACTION_GENERIC_ERROR;3676}else{3677 update->flags |= REF_NEEDS_COMMIT;3678}3679}3680if(!(update->flags & REF_NEEDS_COMMIT)) {3681/*3682 * We didn't call write_ref_to_lockfile(), so3683 * the lockfile is still open. Close it to3684 * free up the file descriptor:3685 */3686if(close_ref(lock)) {3687strbuf_addf(err,"couldn't close '%s.lock'",3688 update->refname);3689return TRANSACTION_GENERIC_ERROR;3690}3691}3692return0;3693}36943695static intfiles_transaction_commit(struct ref_store *ref_store,3696struct ref_transaction *transaction,3697struct strbuf *err)3698{3699struct files_ref_store *refs =3700files_downcast(ref_store,0,"ref_transaction_commit");3701int ret =0, i;3702struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3703struct string_list_item *ref_to_delete;3704struct string_list affected_refnames = STRING_LIST_INIT_NODUP;3705char*head_ref = NULL;3706int head_type;3707struct object_id head_oid;37083709assert(err);37103711if(transaction->state != REF_TRANSACTION_OPEN)3712die("BUG: commit called for transaction that is not open");37133714if(!transaction->nr) {3715 transaction->state = REF_TRANSACTION_CLOSED;3716return0;3717}37183719/*3720 * Fail if a refname appears more than once in the3721 * transaction. (If we end up splitting up any updates using3722 * split_symref_update() or split_head_update(), those3723 * functions will check that the new updates don't have the3724 * same refname as any existing ones.)3725 */3726for(i =0; i < transaction->nr; i++) {3727struct ref_update *update = transaction->updates[i];3728struct string_list_item *item =3729string_list_append(&affected_refnames, update->refname);37303731/*3732 * We store a pointer to update in item->util, but at3733 * the moment we never use the value of this field3734 * except to check whether it is non-NULL.3735 */3736 item->util = update;3737}3738string_list_sort(&affected_refnames);3739if(ref_update_reject_duplicates(&affected_refnames, err)) {3740 ret = TRANSACTION_GENERIC_ERROR;3741goto cleanup;3742}37433744/*3745 * Special hack: If a branch is updated directly and HEAD3746 * points to it (may happen on the remote side of a push3747 * for example) then logically the HEAD reflog should be3748 * updated too.3749 *3750 * A generic solution would require reverse symref lookups,3751 * but finding all symrefs pointing to a given branch would be3752 * rather costly for this rare event (the direct update of a3753 * branch) to be worth it. So let's cheat and check with HEAD3754 * only, which should cover 99% of all usage scenarios (even3755 * 100% of the default ones).3756 *3757 * So if HEAD is a symbolic reference, then record the name of3758 * the reference that it points to. If we see an update of3759 * head_ref within the transaction, then split_head_update()3760 * arranges for the reflog of HEAD to be updated, too.3761 */3762 head_ref =resolve_refdup("HEAD", RESOLVE_REF_NO_RECURSE,3763 head_oid.hash, &head_type);37643765if(head_ref && !(head_type & REF_ISSYMREF)) {3766free(head_ref);3767 head_ref = NULL;3768}37693770/*3771 * Acquire all locks, verify old values if provided, check3772 * that new values are valid, and write new values to the3773 * lockfiles, ready to be activated. Only keep one lockfile3774 * open at a time to avoid running out of file descriptors.3775 */3776for(i =0; i < transaction->nr; i++) {3777struct ref_update *update = transaction->updates[i];37783779 ret =lock_ref_for_update(refs, update, transaction,3780 head_ref, &affected_refnames, err);3781if(ret)3782goto cleanup;3783}37843785/* Perform updates first so live commits remain referenced */3786for(i =0; i < transaction->nr; i++) {3787struct ref_update *update = transaction->updates[i];3788struct ref_lock *lock = update->backend_data;37893790if(update->flags & REF_NEEDS_COMMIT ||3791 update->flags & REF_LOG_ONLY) {3792if(files_log_ref_write(lock->ref_name,3793 lock->old_oid.hash,3794 update->new_sha1,3795 update->msg, update->flags,3796 err)) {3797char*old_msg =strbuf_detach(err, NULL);37983799strbuf_addf(err,"cannot update the ref '%s':%s",3800 lock->ref_name, old_msg);3801free(old_msg);3802unlock_ref(lock);3803 update->backend_data = NULL;3804 ret = TRANSACTION_GENERIC_ERROR;3805goto cleanup;3806}3807}3808if(update->flags & REF_NEEDS_COMMIT) {3809clear_loose_ref_cache(refs);3810if(commit_ref(lock)) {3811strbuf_addf(err,"couldn't set '%s'", lock->ref_name);3812unlock_ref(lock);3813 update->backend_data = NULL;3814 ret = TRANSACTION_GENERIC_ERROR;3815goto cleanup;3816}3817}3818}3819/* Perform deletes now that updates are safely completed */3820for(i =0; i < transaction->nr; i++) {3821struct ref_update *update = transaction->updates[i];3822struct ref_lock *lock = update->backend_data;38233824if(update->flags & REF_DELETING &&3825!(update->flags & REF_LOG_ONLY)) {3826if(!(update->type & REF_ISPACKED) ||3827 update->type & REF_ISSYMREF) {3828/* It is a loose reference. */3829if(unlink_or_msg(git_path("%s", lock->ref_name), err)) {3830 ret = TRANSACTION_GENERIC_ERROR;3831goto cleanup;3832}3833 update->flags |= REF_DELETED_LOOSE;3834}38353836if(!(update->flags & REF_ISPRUNING))3837string_list_append(&refs_to_delete,3838 lock->ref_name);3839}3840}38413842if(repack_without_refs(refs, &refs_to_delete, err)) {3843 ret = TRANSACTION_GENERIC_ERROR;3844goto cleanup;3845}38463847/* Delete the reflogs of any references that were deleted: */3848for_each_string_list_item(ref_to_delete, &refs_to_delete) {3849if(!unlink_or_warn(git_path("logs/%s", ref_to_delete->string)))3850try_remove_empty_parents(ref_to_delete->string,3851 REMOVE_EMPTY_PARENTS_REFLOG);3852}38533854clear_loose_ref_cache(refs);38553856cleanup:3857 transaction->state = REF_TRANSACTION_CLOSED;38583859for(i =0; i < transaction->nr; i++) {3860struct ref_update *update = transaction->updates[i];3861struct ref_lock *lock = update->backend_data;38623863if(lock)3864unlock_ref(lock);38653866if(update->flags & REF_DELETED_LOOSE) {3867/*3868 * The loose reference was deleted. Delete any3869 * empty parent directories. (Note that this3870 * can only work because we have already3871 * removed the lockfile.)3872 */3873try_remove_empty_parents(update->refname,3874 REMOVE_EMPTY_PARENTS_REF);3875}3876}38773878string_list_clear(&refs_to_delete,0);3879free(head_ref);3880string_list_clear(&affected_refnames,0);38813882return ret;3883}38843885static intref_present(const char*refname,3886const struct object_id *oid,int flags,void*cb_data)3887{3888struct string_list *affected_refnames = cb_data;38893890returnstring_list_has_string(affected_refnames, refname);3891}38923893static intfiles_initial_transaction_commit(struct ref_store *ref_store,3894struct ref_transaction *transaction,3895struct strbuf *err)3896{3897struct files_ref_store *refs =3898files_downcast(ref_store,0,"initial_ref_transaction_commit");3899int ret =0, i;3900struct string_list affected_refnames = STRING_LIST_INIT_NODUP;39013902assert(err);39033904if(transaction->state != REF_TRANSACTION_OPEN)3905die("BUG: commit called for transaction that is not open");39063907/* Fail if a refname appears more than once in the transaction: */3908for(i =0; i < transaction->nr; i++)3909string_list_append(&affected_refnames,3910 transaction->updates[i]->refname);3911string_list_sort(&affected_refnames);3912if(ref_update_reject_duplicates(&affected_refnames, err)) {3913 ret = TRANSACTION_GENERIC_ERROR;3914goto cleanup;3915}39163917/*3918 * It's really undefined to call this function in an active3919 * repository or when there are existing references: we are3920 * only locking and changing packed-refs, so (1) any3921 * simultaneous processes might try to change a reference at3922 * the same time we do, and (2) any existing loose versions of3923 * the references that we are setting would have precedence3924 * over our values. But some remote helpers create the remote3925 * "HEAD" and "master" branches before calling this function,3926 * so here we really only check that none of the references3927 * that we are creating already exists.3928 */3929if(for_each_rawref(ref_present, &affected_refnames))3930die("BUG: initial ref transaction called with existing refs");39313932for(i =0; i < transaction->nr; i++) {3933struct ref_update *update = transaction->updates[i];39343935if((update->flags & REF_HAVE_OLD) &&3936!is_null_sha1(update->old_sha1))3937die("BUG: initial ref transaction with old_sha1 set");3938if(verify_refname_available(update->refname,3939&affected_refnames, NULL,3940 err)) {3941 ret = TRANSACTION_NAME_CONFLICT;3942goto cleanup;3943}3944}39453946if(lock_packed_refs(refs,0)) {3947strbuf_addf(err,"unable to lock packed-refs file:%s",3948strerror(errno));3949 ret = TRANSACTION_GENERIC_ERROR;3950goto cleanup;3951}39523953for(i =0; i < transaction->nr; i++) {3954struct ref_update *update = transaction->updates[i];39553956if((update->flags & REF_HAVE_NEW) &&3957!is_null_sha1(update->new_sha1))3958add_packed_ref(refs, update->refname, update->new_sha1);3959}39603961if(commit_packed_refs(refs)) {3962strbuf_addf(err,"unable to commit packed-refs file:%s",3963strerror(errno));3964 ret = TRANSACTION_GENERIC_ERROR;3965goto cleanup;3966}39673968cleanup:3969 transaction->state = REF_TRANSACTION_CLOSED;3970string_list_clear(&affected_refnames,0);3971return ret;3972}39733974struct expire_reflog_cb {3975unsigned int flags;3976 reflog_expiry_should_prune_fn *should_prune_fn;3977void*policy_cb;3978FILE*newlog;3979struct object_id last_kept_oid;3980};39813982static intexpire_reflog_ent(struct object_id *ooid,struct object_id *noid,3983const char*email,unsigned long timestamp,int tz,3984const char*message,void*cb_data)3985{3986struct expire_reflog_cb *cb = cb_data;3987struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;39883989if(cb->flags & EXPIRE_REFLOGS_REWRITE)3990 ooid = &cb->last_kept_oid;39913992if((*cb->should_prune_fn)(ooid->hash, noid->hash, email, timestamp, tz,3993 message, policy_cb)) {3994if(!cb->newlog)3995printf("would prune%s", message);3996else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3997printf("prune%s", message);3998}else{3999if(cb->newlog) {4000fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",4001oid_to_hex(ooid),oid_to_hex(noid),4002 email, timestamp, tz, message);4003oidcpy(&cb->last_kept_oid, noid);4004}4005if(cb->flags & EXPIRE_REFLOGS_VERBOSE)4006printf("keep%s", message);4007}4008return0;4009}40104011static intfiles_reflog_expire(struct ref_store *ref_store,4012const char*refname,const unsigned char*sha1,4013unsigned int flags,4014 reflog_expiry_prepare_fn prepare_fn,4015 reflog_expiry_should_prune_fn should_prune_fn,4016 reflog_expiry_cleanup_fn cleanup_fn,4017void*policy_cb_data)4018{4019struct files_ref_store *refs =4020files_downcast(ref_store,0,"reflog_expire");4021static struct lock_file reflog_lock;4022struct expire_reflog_cb cb;4023struct ref_lock *lock;4024char*log_file;4025int status =0;4026int type;4027struct strbuf err = STRBUF_INIT;40284029memset(&cb,0,sizeof(cb));4030 cb.flags = flags;4031 cb.policy_cb = policy_cb_data;4032 cb.should_prune_fn = should_prune_fn;40334034/*4035 * The reflog file is locked by holding the lock on the4036 * reference itself, plus we might need to update the4037 * reference if --updateref was specified:4038 */4039 lock =lock_ref_sha1_basic(refs, refname, sha1,4040 NULL, NULL, REF_NODEREF,4041&type, &err);4042if(!lock) {4043error("cannot lock ref '%s':%s", refname, err.buf);4044strbuf_release(&err);4045return-1;4046}4047if(!reflog_exists(refname)) {4048unlock_ref(lock);4049return0;4050}40514052 log_file =git_pathdup("logs/%s", refname);4053if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4054/*4055 * Even though holding $GIT_DIR/logs/$reflog.lock has4056 * no locking implications, we use the lock_file4057 * machinery here anyway because it does a lot of the4058 * work we need, including cleaning up if the program4059 * exits unexpectedly.4060 */4061if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4062struct strbuf err = STRBUF_INIT;4063unable_to_lock_message(log_file, errno, &err);4064error("%s", err.buf);4065strbuf_release(&err);4066goto failure;4067}4068 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4069if(!cb.newlog) {4070error("cannot fdopen%s(%s)",4071get_lock_file_path(&reflog_lock),strerror(errno));4072goto failure;4073}4074}40754076(*prepare_fn)(refname, sha1, cb.policy_cb);4077for_each_reflog_ent(refname, expire_reflog_ent, &cb);4078(*cleanup_fn)(cb.policy_cb);40794080if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4081/*4082 * It doesn't make sense to adjust a reference pointed4083 * to by a symbolic ref based on expiring entries in4084 * the symbolic reference's reflog. Nor can we update4085 * a reference if there are no remaining reflog4086 * entries.4087 */4088int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4089!(type & REF_ISSYMREF) &&4090!is_null_oid(&cb.last_kept_oid);40914092if(close_lock_file(&reflog_lock)) {4093 status |=error("couldn't write%s:%s", log_file,4094strerror(errno));4095}else if(update &&4096(write_in_full(get_lock_file_fd(lock->lk),4097oid_to_hex(&cb.last_kept_oid), GIT_SHA1_HEXSZ) != GIT_SHA1_HEXSZ ||4098write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||4099close_ref(lock) <0)) {4100 status |=error("couldn't write%s",4101get_lock_file_path(lock->lk));4102rollback_lock_file(&reflog_lock);4103}else if(commit_lock_file(&reflog_lock)) {4104 status |=error("unable to write reflog '%s' (%s)",4105 log_file,strerror(errno));4106}else if(update &&commit_ref(lock)) {4107 status |=error("couldn't set%s", lock->ref_name);4108}4109}4110free(log_file);4111unlock_ref(lock);4112return status;41134114 failure:4115rollback_lock_file(&reflog_lock);4116free(log_file);4117unlock_ref(lock);4118return-1;4119}41204121static intfiles_init_db(struct ref_store *ref_store,struct strbuf *err)4122{4123/* Check validity (but we don't need the result): */4124files_downcast(ref_store,0,"init_db");41254126/*4127 * Create .git/refs/{heads,tags}4128 */4129safe_create_dir(git_path("refs/heads"),1);4130safe_create_dir(git_path("refs/tags"),1);4131return0;4132}41334134struct ref_storage_be refs_be_files = {4135 NULL,4136"files",4137 files_ref_store_create,4138 files_init_db,4139 files_transaction_commit,4140 files_initial_transaction_commit,41414142 files_pack_refs,4143 files_peel_ref,4144 files_create_symref,4145 files_delete_refs,4146 files_rename_ref,41474148 files_ref_iterator_begin,4149 files_read_raw_ref,4150 files_verify_refname_available,41514152 files_reflog_iterator_begin,4153 files_for_each_reflog_ent,4154 files_for_each_reflog_ent_reverse,4155 files_reflog_exists,4156 files_create_reflog,4157 files_delete_reflog,4158 files_reflog_expire4159};