1#include"../cache.h" 2#include"../refs.h" 3#include"refs-internal.h" 4#include"../lockfile.h" 5#include"../object.h" 6#include"../dir.h" 7 8struct ref_lock { 9char*ref_name; 10char*orig_ref_name; 11struct lock_file *lk; 12struct object_id old_oid; 13}; 14 15struct ref_entry; 16 17/* 18 * Information used (along with the information in ref_entry) to 19 * describe a single cached reference. This data structure only 20 * occurs embedded in a union in struct ref_entry, and only when 21 * (ref_entry->flag & REF_DIR) is zero. 22 */ 23struct ref_value { 24/* 25 * The name of the object to which this reference resolves 26 * (which may be a tag object). If REF_ISBROKEN, this is 27 * null. If REF_ISSYMREF, then this is the name of the object 28 * referred to by the last reference in the symlink chain. 29 */ 30struct object_id oid; 31 32/* 33 * If REF_KNOWS_PEELED, then this field holds the peeled value 34 * of this reference, or null if the reference is known not to 35 * be peelable. See the documentation for peel_ref() for an 36 * exact definition of "peelable". 37 */ 38struct object_id peeled; 39}; 40 41struct ref_cache; 42 43/* 44 * Information used (along with the information in ref_entry) to 45 * describe a level in the hierarchy of references. This data 46 * structure only occurs embedded in a union in struct ref_entry, and 47 * only when (ref_entry.flag & REF_DIR) is set. In that case, 48 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 49 * in the directory have already been read: 50 * 51 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 52 * or packed references, already read. 53 * 54 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 55 * references that hasn't been read yet (nor has any of its 56 * subdirectories). 57 * 58 * Entries within a directory are stored within a growable array of 59 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 60 * sorted are sorted by their component name in strcmp() order and the 61 * remaining entries are unsorted. 62 * 63 * Loose references are read lazily, one directory at a time. When a 64 * directory of loose references is read, then all of the references 65 * in that directory are stored, and REF_INCOMPLETE stubs are created 66 * for any subdirectories, but the subdirectories themselves are not 67 * read. The reading is triggered by get_ref_dir(). 68 */ 69struct ref_dir { 70int nr, alloc; 71 72/* 73 * Entries with index 0 <= i < sorted are sorted by name. New 74 * entries are appended to the list unsorted, and are sorted 75 * only when required; thus we avoid the need to sort the list 76 * after the addition of every reference. 77 */ 78int sorted; 79 80/* A pointer to the ref_cache that contains this ref_dir. */ 81struct ref_cache *ref_cache; 82 83struct ref_entry **entries; 84}; 85 86/* 87 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 88 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 89 * public values; see refs.h. 90 */ 91 92/* 93 * The field ref_entry->u.value.peeled of this value entry contains 94 * the correct peeled value for the reference, which might be 95 * null_sha1 if the reference is not a tag or if it is broken. 96 */ 97#define REF_KNOWS_PEELED 0x10 98 99/* ref_entry represents a directory of references */ 100#define REF_DIR 0x20 101 102/* 103 * Entry has not yet been read from disk (used only for REF_DIR 104 * entries representing loose references) 105 */ 106#define REF_INCOMPLETE 0x40 107 108/* 109 * A ref_entry represents either a reference or a "subdirectory" of 110 * references. 111 * 112 * Each directory in the reference namespace is represented by a 113 * ref_entry with (flags & REF_DIR) set and containing a subdir member 114 * that holds the entries in that directory that have been read so 115 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 116 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 117 * used for loose reference directories. 118 * 119 * References are represented by a ref_entry with (flags & REF_DIR) 120 * unset and a value member that describes the reference's value. The 121 * flag member is at the ref_entry level, but it is also needed to 122 * interpret the contents of the value field (in other words, a 123 * ref_value object is not very much use without the enclosing 124 * ref_entry). 125 * 126 * Reference names cannot end with slash and directories' names are 127 * always stored with a trailing slash (except for the top-level 128 * directory, which is always denoted by ""). This has two nice 129 * consequences: (1) when the entries in each subdir are sorted 130 * lexicographically by name (as they usually are), the references in 131 * a whole tree can be generated in lexicographic order by traversing 132 * the tree in left-to-right, depth-first order; (2) the names of 133 * references and subdirectories cannot conflict, and therefore the 134 * presence of an empty subdirectory does not block the creation of a 135 * similarly-named reference. (The fact that reference names with the 136 * same leading components can conflict *with each other* is a 137 * separate issue that is regulated by verify_refname_available().) 138 * 139 * Please note that the name field contains the fully-qualified 140 * reference (or subdirectory) name. Space could be saved by only 141 * storing the relative names. But that would require the full names 142 * to be generated on the fly when iterating in do_for_each_ref(), and 143 * would break callback functions, who have always been able to assume 144 * that the name strings that they are passed will not be freed during 145 * the iteration. 146 */ 147struct ref_entry { 148unsigned char flag;/* ISSYMREF? ISPACKED? */ 149union{ 150struct ref_value value;/* if not (flags&REF_DIR) */ 151struct ref_dir subdir;/* if (flags&REF_DIR) */ 152} u; 153/* 154 * The full name of the reference (e.g., "refs/heads/master") 155 * or the full name of the directory with a trailing slash 156 * (e.g., "refs/heads/"): 157 */ 158char name[FLEX_ARRAY]; 159}; 160 161static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 162static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len); 163static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 164const char*dirname,size_t len, 165int incomplete); 166static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry); 167 168static struct ref_dir *get_ref_dir(struct ref_entry *entry) 169{ 170struct ref_dir *dir; 171assert(entry->flag & REF_DIR); 172 dir = &entry->u.subdir; 173if(entry->flag & REF_INCOMPLETE) { 174read_loose_refs(entry->name, dir); 175 176/* 177 * Manually add refs/bisect, which, being 178 * per-worktree, might not appear in the directory 179 * listing for refs/ in the main repo. 180 */ 181if(!strcmp(entry->name,"refs/")) { 182int pos =search_ref_dir(dir,"refs/bisect/",12); 183if(pos <0) { 184struct ref_entry *child_entry; 185 child_entry =create_dir_entry(dir->ref_cache, 186"refs/bisect/", 18712,1); 188add_entry_to_dir(dir, child_entry); 189read_loose_refs("refs/bisect", 190&child_entry->u.subdir); 191} 192} 193 entry->flag &= ~REF_INCOMPLETE; 194} 195return dir; 196} 197 198static struct ref_entry *create_ref_entry(const char*refname, 199const unsigned char*sha1,int flag, 200int check_name) 201{ 202struct ref_entry *ref; 203 204if(check_name && 205check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 206die("Reference has invalid format: '%s'", refname); 207FLEX_ALLOC_STR(ref, name, refname); 208hashcpy(ref->u.value.oid.hash, sha1); 209oidclr(&ref->u.value.peeled); 210 ref->flag = flag; 211return ref; 212} 213 214static voidclear_ref_dir(struct ref_dir *dir); 215 216static voidfree_ref_entry(struct ref_entry *entry) 217{ 218if(entry->flag & REF_DIR) { 219/* 220 * Do not use get_ref_dir() here, as that might 221 * trigger the reading of loose refs. 222 */ 223clear_ref_dir(&entry->u.subdir); 224} 225free(entry); 226} 227 228/* 229 * Add a ref_entry to the end of dir (unsorted). Entry is always 230 * stored directly in dir; no recursion into subdirectories is 231 * done. 232 */ 233static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 234{ 235ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 236 dir->entries[dir->nr++] = entry; 237/* optimize for the case that entries are added in order */ 238if(dir->nr ==1|| 239(dir->nr == dir->sorted +1&& 240strcmp(dir->entries[dir->nr -2]->name, 241 dir->entries[dir->nr -1]->name) <0)) 242 dir->sorted = dir->nr; 243} 244 245/* 246 * Clear and free all entries in dir, recursively. 247 */ 248static voidclear_ref_dir(struct ref_dir *dir) 249{ 250int i; 251for(i =0; i < dir->nr; i++) 252free_ref_entry(dir->entries[i]); 253free(dir->entries); 254 dir->sorted = dir->nr = dir->alloc =0; 255 dir->entries = NULL; 256} 257 258/* 259 * Create a struct ref_entry object for the specified dirname. 260 * dirname is the name of the directory with a trailing slash (e.g., 261 * "refs/heads/") or "" for the top-level directory. 262 */ 263static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 264const char*dirname,size_t len, 265int incomplete) 266{ 267struct ref_entry *direntry; 268FLEX_ALLOC_MEM(direntry, name, dirname, len); 269 direntry->u.subdir.ref_cache = ref_cache; 270 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 271return direntry; 272} 273 274static intref_entry_cmp(const void*a,const void*b) 275{ 276struct ref_entry *one = *(struct ref_entry **)a; 277struct ref_entry *two = *(struct ref_entry **)b; 278returnstrcmp(one->name, two->name); 279} 280 281static voidsort_ref_dir(struct ref_dir *dir); 282 283struct string_slice { 284size_t len; 285const char*str; 286}; 287 288static intref_entry_cmp_sslice(const void*key_,const void*ent_) 289{ 290const struct string_slice *key = key_; 291const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 292int cmp =strncmp(key->str, ent->name, key->len); 293if(cmp) 294return cmp; 295return'\0'- (unsigned char)ent->name[key->len]; 296} 297 298/* 299 * Return the index of the entry with the given refname from the 300 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 301 * no such entry is found. dir must already be complete. 302 */ 303static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 304{ 305struct ref_entry **r; 306struct string_slice key; 307 308if(refname == NULL || !dir->nr) 309return-1; 310 311sort_ref_dir(dir); 312 key.len = len; 313 key.str = refname; 314 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 315 ref_entry_cmp_sslice); 316 317if(r == NULL) 318return-1; 319 320return r - dir->entries; 321} 322 323/* 324 * Search for a directory entry directly within dir (without 325 * recursing). Sort dir if necessary. subdirname must be a directory 326 * name (i.e., end in '/'). If mkdir is set, then create the 327 * directory if it is missing; otherwise, return NULL if the desired 328 * directory cannot be found. dir must already be complete. 329 */ 330static struct ref_dir *search_for_subdir(struct ref_dir *dir, 331const char*subdirname,size_t len, 332int mkdir) 333{ 334int entry_index =search_ref_dir(dir, subdirname, len); 335struct ref_entry *entry; 336if(entry_index == -1) { 337if(!mkdir) 338return NULL; 339/* 340 * Since dir is complete, the absence of a subdir 341 * means that the subdir really doesn't exist; 342 * therefore, create an empty record for it but mark 343 * the record complete. 344 */ 345 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 346add_entry_to_dir(dir, entry); 347}else{ 348 entry = dir->entries[entry_index]; 349} 350returnget_ref_dir(entry); 351} 352 353/* 354 * If refname is a reference name, find the ref_dir within the dir 355 * tree that should hold refname. If refname is a directory name 356 * (i.e., ends in '/'), then return that ref_dir itself. dir must 357 * represent the top-level directory and must already be complete. 358 * Sort ref_dirs and recurse into subdirectories as necessary. If 359 * mkdir is set, then create any missing directories; otherwise, 360 * return NULL if the desired directory cannot be found. 361 */ 362static struct ref_dir *find_containing_dir(struct ref_dir *dir, 363const char*refname,int mkdir) 364{ 365const char*slash; 366for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 367size_t dirnamelen = slash - refname +1; 368struct ref_dir *subdir; 369 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 370if(!subdir) { 371 dir = NULL; 372break; 373} 374 dir = subdir; 375} 376 377return dir; 378} 379 380/* 381 * Find the value entry with the given name in dir, sorting ref_dirs 382 * and recursing into subdirectories as necessary. If the name is not 383 * found or it corresponds to a directory entry, return NULL. 384 */ 385static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 386{ 387int entry_index; 388struct ref_entry *entry; 389 dir =find_containing_dir(dir, refname,0); 390if(!dir) 391return NULL; 392 entry_index =search_ref_dir(dir, refname,strlen(refname)); 393if(entry_index == -1) 394return NULL; 395 entry = dir->entries[entry_index]; 396return(entry->flag & REF_DIR) ? NULL : entry; 397} 398 399/* 400 * Remove the entry with the given name from dir, recursing into 401 * subdirectories as necessary. If refname is the name of a directory 402 * (i.e., ends with '/'), then remove the directory and its contents. 403 * If the removal was successful, return the number of entries 404 * remaining in the directory entry that contained the deleted entry. 405 * If the name was not found, return -1. Please note that this 406 * function only deletes the entry from the cache; it does not delete 407 * it from the filesystem or ensure that other cache entries (which 408 * might be symbolic references to the removed entry) are updated. 409 * Nor does it remove any containing dir entries that might be made 410 * empty by the removal. dir must represent the top-level directory 411 * and must already be complete. 412 */ 413static intremove_entry(struct ref_dir *dir,const char*refname) 414{ 415int refname_len =strlen(refname); 416int entry_index; 417struct ref_entry *entry; 418int is_dir = refname[refname_len -1] =='/'; 419if(is_dir) { 420/* 421 * refname represents a reference directory. Remove 422 * the trailing slash; otherwise we will get the 423 * directory *representing* refname rather than the 424 * one *containing* it. 425 */ 426char*dirname =xmemdupz(refname, refname_len -1); 427 dir =find_containing_dir(dir, dirname,0); 428free(dirname); 429}else{ 430 dir =find_containing_dir(dir, refname,0); 431} 432if(!dir) 433return-1; 434 entry_index =search_ref_dir(dir, refname, refname_len); 435if(entry_index == -1) 436return-1; 437 entry = dir->entries[entry_index]; 438 439memmove(&dir->entries[entry_index], 440&dir->entries[entry_index +1], 441(dir->nr - entry_index -1) *sizeof(*dir->entries) 442); 443 dir->nr--; 444if(dir->sorted > entry_index) 445 dir->sorted--; 446free_ref_entry(entry); 447return dir->nr; 448} 449 450/* 451 * Add a ref_entry to the ref_dir (unsorted), recursing into 452 * subdirectories as necessary. dir must represent the top-level 453 * directory. Return 0 on success. 454 */ 455static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 456{ 457 dir =find_containing_dir(dir, ref->name,1); 458if(!dir) 459return-1; 460add_entry_to_dir(dir, ref); 461return0; 462} 463 464/* 465 * Emit a warning and return true iff ref1 and ref2 have the same name 466 * and the same sha1. Die if they have the same name but different 467 * sha1s. 468 */ 469static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 470{ 471if(strcmp(ref1->name, ref2->name)) 472return0; 473 474/* Duplicate name; make sure that they don't conflict: */ 475 476if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 477/* This is impossible by construction */ 478die("Reference directory conflict:%s", ref1->name); 479 480if(oidcmp(&ref1->u.value.oid, &ref2->u.value.oid)) 481die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 482 483warning("Duplicated ref:%s", ref1->name); 484return1; 485} 486 487/* 488 * Sort the entries in dir non-recursively (if they are not already 489 * sorted) and remove any duplicate entries. 490 */ 491static voidsort_ref_dir(struct ref_dir *dir) 492{ 493int i, j; 494struct ref_entry *last = NULL; 495 496/* 497 * This check also prevents passing a zero-length array to qsort(), 498 * which is a problem on some platforms. 499 */ 500if(dir->sorted == dir->nr) 501return; 502 503qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 504 505/* Remove any duplicates: */ 506for(i =0, j =0; j < dir->nr; j++) { 507struct ref_entry *entry = dir->entries[j]; 508if(last &&is_dup_ref(last, entry)) 509free_ref_entry(entry); 510else 511 last = dir->entries[i++] = entry; 512} 513 dir->sorted = dir->nr = i; 514} 515 516/* 517 * Return true iff the reference described by entry can be resolved to 518 * an object in the database. Emit a warning if the referred-to 519 * object does not exist. 520 */ 521static intref_resolves_to_object(struct ref_entry *entry) 522{ 523if(entry->flag & REF_ISBROKEN) 524return0; 525if(!has_sha1_file(entry->u.value.oid.hash)) { 526error("%sdoes not point to a valid object!", entry->name); 527return0; 528} 529return1; 530} 531 532/* 533 * current_ref is a performance hack: when iterating over references 534 * using the for_each_ref*() functions, current_ref is set to the 535 * current reference's entry before calling the callback function. If 536 * the callback function calls peel_ref(), then peel_ref() first 537 * checks whether the reference to be peeled is the current reference 538 * (it usually is) and if so, returns that reference's peeled version 539 * if it is available. This avoids a refname lookup in a common case. 540 */ 541static struct ref_entry *current_ref; 542 543typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 544 545struct ref_entry_cb { 546const char*base; 547int trim; 548int flags; 549 each_ref_fn *fn; 550void*cb_data; 551}; 552 553/* 554 * Handle one reference in a do_for_each_ref*()-style iteration, 555 * calling an each_ref_fn for each entry. 556 */ 557static intdo_one_ref(struct ref_entry *entry,void*cb_data) 558{ 559struct ref_entry_cb *data = cb_data; 560struct ref_entry *old_current_ref; 561int retval; 562 563if(!starts_with(entry->name, data->base)) 564return0; 565 566if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 567!ref_resolves_to_object(entry)) 568return0; 569 570/* Store the old value, in case this is a recursive call: */ 571 old_current_ref = current_ref; 572 current_ref = entry; 573 retval = data->fn(entry->name + data->trim, &entry->u.value.oid, 574 entry->flag, data->cb_data); 575 current_ref = old_current_ref; 576return retval; 577} 578 579/* 580 * Call fn for each reference in dir that has index in the range 581 * offset <= index < dir->nr. Recurse into subdirectories that are in 582 * that index range, sorting them before iterating. This function 583 * does not sort dir itself; it should be sorted beforehand. fn is 584 * called for all references, including broken ones. 585 */ 586static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 587 each_ref_entry_fn fn,void*cb_data) 588{ 589int i; 590assert(dir->sorted == dir->nr); 591for(i = offset; i < dir->nr; i++) { 592struct ref_entry *entry = dir->entries[i]; 593int retval; 594if(entry->flag & REF_DIR) { 595struct ref_dir *subdir =get_ref_dir(entry); 596sort_ref_dir(subdir); 597 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 598}else{ 599 retval =fn(entry, cb_data); 600} 601if(retval) 602return retval; 603} 604return0; 605} 606 607/* 608 * Call fn for each reference in the union of dir1 and dir2, in order 609 * by refname. Recurse into subdirectories. If a value entry appears 610 * in both dir1 and dir2, then only process the version that is in 611 * dir2. The input dirs must already be sorted, but subdirs will be 612 * sorted as needed. fn is called for all references, including 613 * broken ones. 614 */ 615static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 616struct ref_dir *dir2, 617 each_ref_entry_fn fn,void*cb_data) 618{ 619int retval; 620int i1 =0, i2 =0; 621 622assert(dir1->sorted == dir1->nr); 623assert(dir2->sorted == dir2->nr); 624while(1) { 625struct ref_entry *e1, *e2; 626int cmp; 627if(i1 == dir1->nr) { 628returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 629} 630if(i2 == dir2->nr) { 631returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 632} 633 e1 = dir1->entries[i1]; 634 e2 = dir2->entries[i2]; 635 cmp =strcmp(e1->name, e2->name); 636if(cmp ==0) { 637if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 638/* Both are directories; descend them in parallel. */ 639struct ref_dir *subdir1 =get_ref_dir(e1); 640struct ref_dir *subdir2 =get_ref_dir(e2); 641sort_ref_dir(subdir1); 642sort_ref_dir(subdir2); 643 retval =do_for_each_entry_in_dirs( 644 subdir1, subdir2, fn, cb_data); 645 i1++; 646 i2++; 647}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 648/* Both are references; ignore the one from dir1. */ 649 retval =fn(e2, cb_data); 650 i1++; 651 i2++; 652}else{ 653die("conflict between reference and directory:%s", 654 e1->name); 655} 656}else{ 657struct ref_entry *e; 658if(cmp <0) { 659 e = e1; 660 i1++; 661}else{ 662 e = e2; 663 i2++; 664} 665if(e->flag & REF_DIR) { 666struct ref_dir *subdir =get_ref_dir(e); 667sort_ref_dir(subdir); 668 retval =do_for_each_entry_in_dir( 669 subdir,0, fn, cb_data); 670}else{ 671 retval =fn(e, cb_data); 672} 673} 674if(retval) 675return retval; 676} 677} 678 679/* 680 * Load all of the refs from the dir into our in-memory cache. The hard work 681 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 682 * through all of the sub-directories. We do not even need to care about 683 * sorting, as traversal order does not matter to us. 684 */ 685static voidprime_ref_dir(struct ref_dir *dir) 686{ 687int i; 688for(i =0; i < dir->nr; i++) { 689struct ref_entry *entry = dir->entries[i]; 690if(entry->flag & REF_DIR) 691prime_ref_dir(get_ref_dir(entry)); 692} 693} 694 695struct nonmatching_ref_data { 696const struct string_list *skip; 697const char*conflicting_refname; 698}; 699 700static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 701{ 702struct nonmatching_ref_data *data = vdata; 703 704if(data->skip &&string_list_has_string(data->skip, entry->name)) 705return0; 706 707 data->conflicting_refname = entry->name; 708return1; 709} 710 711/* 712 * Return 0 if a reference named refname could be created without 713 * conflicting with the name of an existing reference in dir. 714 * See verify_refname_available for more information. 715 */ 716static intverify_refname_available_dir(const char*refname, 717const struct string_list *extras, 718const struct string_list *skip, 719struct ref_dir *dir, 720struct strbuf *err) 721{ 722const char*slash; 723const char*extra_refname; 724int pos; 725struct strbuf dirname = STRBUF_INIT; 726int ret = -1; 727 728/* 729 * For the sake of comments in this function, suppose that 730 * refname is "refs/foo/bar". 731 */ 732 733assert(err); 734 735strbuf_grow(&dirname,strlen(refname) +1); 736for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 737/* Expand dirname to the new prefix, not including the trailing slash: */ 738strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len); 739 740/* 741 * We are still at a leading dir of the refname (e.g., 742 * "refs/foo"; if there is a reference with that name, 743 * it is a conflict, *unless* it is in skip. 744 */ 745if(dir) { 746 pos =search_ref_dir(dir, dirname.buf, dirname.len); 747if(pos >=0&& 748(!skip || !string_list_has_string(skip, dirname.buf))) { 749/* 750 * We found a reference whose name is 751 * a proper prefix of refname; e.g., 752 * "refs/foo", and is not in skip. 753 */ 754strbuf_addf(err,"'%s' exists; cannot create '%s'", 755 dirname.buf, refname); 756goto cleanup; 757} 758} 759 760if(extras &&string_list_has_string(extras, dirname.buf) && 761(!skip || !string_list_has_string(skip, dirname.buf))) { 762strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 763 refname, dirname.buf); 764goto cleanup; 765} 766 767/* 768 * Otherwise, we can try to continue our search with 769 * the next component. So try to look up the 770 * directory, e.g., "refs/foo/". If we come up empty, 771 * we know there is nothing under this whole prefix, 772 * but even in that case we still have to continue the 773 * search for conflicts with extras. 774 */ 775strbuf_addch(&dirname,'/'); 776if(dir) { 777 pos =search_ref_dir(dir, dirname.buf, dirname.len); 778if(pos <0) { 779/* 780 * There was no directory "refs/foo/", 781 * so there is nothing under this 782 * whole prefix. So there is no need 783 * to continue looking for conflicting 784 * references. But we need to continue 785 * looking for conflicting extras. 786 */ 787 dir = NULL; 788}else{ 789 dir =get_ref_dir(dir->entries[pos]); 790} 791} 792} 793 794/* 795 * We are at the leaf of our refname (e.g., "refs/foo/bar"). 796 * There is no point in searching for a reference with that 797 * name, because a refname isn't considered to conflict with 798 * itself. But we still need to check for references whose 799 * names are in the "refs/foo/bar/" namespace, because they 800 * *do* conflict. 801 */ 802strbuf_addstr(&dirname, refname + dirname.len); 803strbuf_addch(&dirname,'/'); 804 805if(dir) { 806 pos =search_ref_dir(dir, dirname.buf, dirname.len); 807 808if(pos >=0) { 809/* 810 * We found a directory named "$refname/" 811 * (e.g., "refs/foo/bar/"). It is a problem 812 * iff it contains any ref that is not in 813 * "skip". 814 */ 815struct nonmatching_ref_data data; 816 817 data.skip = skip; 818 data.conflicting_refname = NULL; 819 dir =get_ref_dir(dir->entries[pos]); 820sort_ref_dir(dir); 821if(do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) { 822strbuf_addf(err,"'%s' exists; cannot create '%s'", 823 data.conflicting_refname, refname); 824goto cleanup; 825} 826} 827} 828 829 extra_refname =find_descendant_ref(dirname.buf, extras, skip); 830if(extra_refname) 831strbuf_addf(err,"cannot process '%s' and '%s' at the same time", 832 refname, extra_refname); 833else 834 ret =0; 835 836cleanup: 837strbuf_release(&dirname); 838return ret; 839} 840 841struct packed_ref_cache { 842struct ref_entry *root; 843 844/* 845 * Count of references to the data structure in this instance, 846 * including the pointer from ref_cache::packed if any. The 847 * data will not be freed as long as the reference count is 848 * nonzero. 849 */ 850unsigned int referrers; 851 852/* 853 * Iff the packed-refs file associated with this instance is 854 * currently locked for writing, this points at the associated 855 * lock (which is owned by somebody else). The referrer count 856 * is also incremented when the file is locked and decremented 857 * when it is unlocked. 858 */ 859struct lock_file *lock; 860 861/* The metadata from when this packed-refs cache was read */ 862struct stat_validity validity; 863}; 864 865/* 866 * Future: need to be in "struct repository" 867 * when doing a full libification. 868 */ 869static struct ref_cache { 870struct ref_cache *next; 871struct ref_entry *loose; 872struct packed_ref_cache *packed; 873/* 874 * The submodule name, or "" for the main repo. We allocate 875 * length 1 rather than FLEX_ARRAY so that the main ref_cache 876 * is initialized correctly. 877 */ 878char name[1]; 879} ref_cache, *submodule_ref_caches; 880 881/* Lock used for the main packed-refs file: */ 882static struct lock_file packlock; 883 884/* 885 * Increment the reference count of *packed_refs. 886 */ 887static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 888{ 889 packed_refs->referrers++; 890} 891 892/* 893 * Decrease the reference count of *packed_refs. If it goes to zero, 894 * free *packed_refs and return true; otherwise return false. 895 */ 896static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 897{ 898if(!--packed_refs->referrers) { 899free_ref_entry(packed_refs->root); 900stat_validity_clear(&packed_refs->validity); 901free(packed_refs); 902return1; 903}else{ 904return0; 905} 906} 907 908static voidclear_packed_ref_cache(struct ref_cache *refs) 909{ 910if(refs->packed) { 911struct packed_ref_cache *packed_refs = refs->packed; 912 913if(packed_refs->lock) 914die("internal error: packed-ref cache cleared while locked"); 915 refs->packed = NULL; 916release_packed_ref_cache(packed_refs); 917} 918} 919 920static voidclear_loose_ref_cache(struct ref_cache *refs) 921{ 922if(refs->loose) { 923free_ref_entry(refs->loose); 924 refs->loose = NULL; 925} 926} 927 928/* 929 * Create a new submodule ref cache and add it to the internal 930 * set of caches. 931 */ 932static struct ref_cache *create_ref_cache(const char*submodule) 933{ 934struct ref_cache *refs; 935if(!submodule) 936 submodule =""; 937FLEX_ALLOC_STR(refs, name, submodule); 938 refs->next = submodule_ref_caches; 939 submodule_ref_caches = refs; 940return refs; 941} 942 943static struct ref_cache *lookup_ref_cache(const char*submodule) 944{ 945struct ref_cache *refs; 946 947if(!submodule || !*submodule) 948return&ref_cache; 949 950for(refs = submodule_ref_caches; refs; refs = refs->next) 951if(!strcmp(submodule, refs->name)) 952return refs; 953return NULL; 954} 955 956/* 957 * Return a pointer to a ref_cache for the specified submodule. For 958 * the main repository, use submodule==NULL. The returned structure 959 * will be allocated and initialized but not necessarily populated; it 960 * should not be freed. 961 */ 962static struct ref_cache *get_ref_cache(const char*submodule) 963{ 964struct ref_cache *refs =lookup_ref_cache(submodule); 965if(!refs) 966 refs =create_ref_cache(submodule); 967return refs; 968} 969 970/* The length of a peeled reference line in packed-refs, including EOL: */ 971#define PEELED_LINE_LENGTH 42 972 973/* 974 * The packed-refs header line that we write out. Perhaps other 975 * traits will be added later. The trailing space is required. 976 */ 977static const char PACKED_REFS_HEADER[] = 978"# pack-refs with: peeled fully-peeled\n"; 979 980/* 981 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 982 * Return a pointer to the refname within the line (null-terminated), 983 * or NULL if there was a problem. 984 */ 985static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1) 986{ 987const char*ref; 988 989/* 990 * 42: the answer to everything. 991 * 992 * In this case, it happens to be the answer to 993 * 40 (length of sha1 hex representation) 994 * +1 (space in between hex and name) 995 * +1 (newline at the end of the line) 996 */ 997if(line->len <=42) 998return NULL; 9991000if(get_sha1_hex(line->buf, sha1) <0)1001return NULL;1002if(!isspace(line->buf[40]))1003return NULL;10041005 ref = line->buf +41;1006if(isspace(*ref))1007return NULL;10081009if(line->buf[line->len -1] !='\n')1010return NULL;1011 line->buf[--line->len] =0;10121013return ref;1014}10151016/*1017 * Read f, which is a packed-refs file, into dir.1018 *1019 * A comment line of the form "# pack-refs with: " may contain zero or1020 * more traits. We interpret the traits as follows:1021 *1022 * No traits:1023 *1024 * Probably no references are peeled. But if the file contains a1025 * peeled value for a reference, we will use it.1026 *1027 * peeled:1028 *1029 * References under "refs/tags/", if they *can* be peeled, *are*1030 * peeled in this file. References outside of "refs/tags/" are1031 * probably not peeled even if they could have been, but if we find1032 * a peeled value for such a reference we will use it.1033 *1034 * fully-peeled:1035 *1036 * All references in the file that can be peeled are peeled.1037 * Inversely (and this is more important), any references in the1038 * file for which no peeled value is recorded is not peelable. This1039 * trait should typically be written alongside "peeled" for1040 * compatibility with older clients, but we do not require it1041 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1042 */1043static voidread_packed_refs(FILE*f,struct ref_dir *dir)1044{1045struct ref_entry *last = NULL;1046struct strbuf line = STRBUF_INIT;1047enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10481049while(strbuf_getwholeline(&line, f,'\n') != EOF) {1050unsigned char sha1[20];1051const char*refname;1052const char*traits;10531054if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1055if(strstr(traits," fully-peeled "))1056 peeled = PEELED_FULLY;1057else if(strstr(traits," peeled "))1058 peeled = PEELED_TAGS;1059/* perhaps other traits later as well */1060continue;1061}10621063 refname =parse_ref_line(&line, sha1);1064if(refname) {1065int flag = REF_ISPACKED;10661067if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1068if(!refname_is_safe(refname))1069die("packed refname is dangerous:%s", refname);1070hashclr(sha1);1071 flag |= REF_BAD_NAME | REF_ISBROKEN;1072}1073 last =create_ref_entry(refname, sha1, flag,0);1074if(peeled == PEELED_FULLY ||1075(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1076 last->flag |= REF_KNOWS_PEELED;1077add_ref(dir, last);1078continue;1079}1080if(last &&1081 line.buf[0] =='^'&&1082 line.len == PEELED_LINE_LENGTH &&1083 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1084!get_sha1_hex(line.buf +1, sha1)) {1085hashcpy(last->u.value.peeled.hash, sha1);1086/*1087 * Regardless of what the file header said,1088 * we definitely know the value of *this*1089 * reference:1090 */1091 last->flag |= REF_KNOWS_PEELED;1092}1093}10941095strbuf_release(&line);1096}10971098/*1099 * Get the packed_ref_cache for the specified ref_cache, creating it1100 * if necessary.1101 */1102static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1103{1104char*packed_refs_file;11051106if(*refs->name)1107 packed_refs_file =git_pathdup_submodule(refs->name,"packed-refs");1108else1109 packed_refs_file =git_pathdup("packed-refs");11101111if(refs->packed &&1112!stat_validity_check(&refs->packed->validity, packed_refs_file))1113clear_packed_ref_cache(refs);11141115if(!refs->packed) {1116FILE*f;11171118 refs->packed =xcalloc(1,sizeof(*refs->packed));1119acquire_packed_ref_cache(refs->packed);1120 refs->packed->root =create_dir_entry(refs,"",0,0);1121 f =fopen(packed_refs_file,"r");1122if(f) {1123stat_validity_update(&refs->packed->validity,fileno(f));1124read_packed_refs(f,get_ref_dir(refs->packed->root));1125fclose(f);1126}1127}1128free(packed_refs_file);1129return refs->packed;1130}11311132static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1133{1134returnget_ref_dir(packed_ref_cache->root);1135}11361137static struct ref_dir *get_packed_refs(struct ref_cache *refs)1138{1139returnget_packed_ref_dir(get_packed_ref_cache(refs));1140}11411142/*1143 * Add a reference to the in-memory packed reference cache. This may1144 * only be called while the packed-refs file is locked (see1145 * lock_packed_refs()). To actually write the packed-refs file, call1146 * commit_packed_refs().1147 */1148static voidadd_packed_ref(const char*refname,const unsigned char*sha1)1149{1150struct packed_ref_cache *packed_ref_cache =1151get_packed_ref_cache(&ref_cache);11521153if(!packed_ref_cache->lock)1154die("internal error: packed refs not locked");1155add_ref(get_packed_ref_dir(packed_ref_cache),1156create_ref_entry(refname, sha1, REF_ISPACKED,1));1157}11581159/*1160 * Read the loose references from the namespace dirname into dir1161 * (without recursing). dirname must end with '/'. dir must be the1162 * directory entry corresponding to dirname.1163 */1164static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1165{1166struct ref_cache *refs = dir->ref_cache;1167DIR*d;1168struct dirent *de;1169int dirnamelen =strlen(dirname);1170struct strbuf refname;1171struct strbuf path = STRBUF_INIT;1172size_t path_baselen;11731174if(*refs->name)1175strbuf_git_path_submodule(&path, refs->name,"%s", dirname);1176else1177strbuf_git_path(&path,"%s", dirname);1178 path_baselen = path.len;11791180 d =opendir(path.buf);1181if(!d) {1182strbuf_release(&path);1183return;1184}11851186strbuf_init(&refname, dirnamelen +257);1187strbuf_add(&refname, dirname, dirnamelen);11881189while((de =readdir(d)) != NULL) {1190unsigned char sha1[20];1191struct stat st;1192int flag;11931194if(de->d_name[0] =='.')1195continue;1196if(ends_with(de->d_name,".lock"))1197continue;1198strbuf_addstr(&refname, de->d_name);1199strbuf_addstr(&path, de->d_name);1200if(stat(path.buf, &st) <0) {1201;/* silently ignore */1202}else if(S_ISDIR(st.st_mode)) {1203strbuf_addch(&refname,'/');1204add_entry_to_dir(dir,1205create_dir_entry(refs, refname.buf,1206 refname.len,1));1207}else{1208int read_ok;12091210if(*refs->name) {1211hashclr(sha1);1212 flag =0;1213 read_ok = !resolve_gitlink_ref(refs->name,1214 refname.buf, sha1);1215}else{1216 read_ok = !read_ref_full(refname.buf,1217 RESOLVE_REF_READING,1218 sha1, &flag);1219}12201221if(!read_ok) {1222hashclr(sha1);1223 flag |= REF_ISBROKEN;1224}else if(is_null_sha1(sha1)) {1225/*1226 * It is so astronomically unlikely1227 * that NULL_SHA1 is the SHA-1 of an1228 * actual object that we consider its1229 * appearance in a loose reference1230 * file to be repo corruption1231 * (probably due to a software bug).1232 */1233 flag |= REF_ISBROKEN;1234}12351236if(check_refname_format(refname.buf,1237 REFNAME_ALLOW_ONELEVEL)) {1238if(!refname_is_safe(refname.buf))1239die("loose refname is dangerous:%s", refname.buf);1240hashclr(sha1);1241 flag |= REF_BAD_NAME | REF_ISBROKEN;1242}1243add_entry_to_dir(dir,1244create_ref_entry(refname.buf, sha1, flag,0));1245}1246strbuf_setlen(&refname, dirnamelen);1247strbuf_setlen(&path, path_baselen);1248}1249strbuf_release(&refname);1250strbuf_release(&path);1251closedir(d);1252}12531254static struct ref_dir *get_loose_refs(struct ref_cache *refs)1255{1256if(!refs->loose) {1257/*1258 * Mark the top-level directory complete because we1259 * are about to read the only subdirectory that can1260 * hold references:1261 */1262 refs->loose =create_dir_entry(refs,"",0,0);1263/*1264 * Create an incomplete entry for "refs/":1265 */1266add_entry_to_dir(get_ref_dir(refs->loose),1267create_dir_entry(refs,"refs/",5,1));1268}1269returnget_ref_dir(refs->loose);1270}12711272#define MAXREFLEN (1024)12731274/*1275 * Called by resolve_gitlink_ref_recursive() after it failed to read1276 * from the loose refs in ref_cache refs. Find <refname> in the1277 * packed-refs file for the submodule.1278 */1279static intresolve_gitlink_packed_ref(struct ref_cache *refs,1280const char*refname,unsigned char*sha1)1281{1282struct ref_entry *ref;1283struct ref_dir *dir =get_packed_refs(refs);12841285 ref =find_ref(dir, refname);1286if(ref == NULL)1287return-1;12881289hashcpy(sha1, ref->u.value.oid.hash);1290return0;1291}12921293static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1294const char*refname,unsigned char*sha1,1295int recursion)1296{1297int fd, len;1298char buffer[128], *p;1299char*path;13001301if(recursion > SYMREF_MAXDEPTH ||strlen(refname) > MAXREFLEN)1302return-1;1303 path = *refs->name1304?git_pathdup_submodule(refs->name,"%s", refname)1305:git_pathdup("%s", refname);1306 fd =open(path, O_RDONLY);1307free(path);1308if(fd <0)1309returnresolve_gitlink_packed_ref(refs, refname, sha1);13101311 len =read(fd, buffer,sizeof(buffer)-1);1312close(fd);1313if(len <0)1314return-1;1315while(len &&isspace(buffer[len-1]))1316 len--;1317 buffer[len] =0;13181319/* Was it a detached head or an old-fashioned symlink? */1320if(!get_sha1_hex(buffer, sha1))1321return0;13221323/* Symref? */1324if(strncmp(buffer,"ref:",4))1325return-1;1326 p = buffer +4;1327while(isspace(*p))1328 p++;13291330returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1331}13321333intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1334{1335int len =strlen(path), retval;1336struct strbuf submodule = STRBUF_INIT;1337struct ref_cache *refs;13381339while(len && path[len-1] =='/')1340 len--;1341if(!len)1342return-1;13431344strbuf_add(&submodule, path, len);1345 refs =lookup_ref_cache(submodule.buf);1346if(!refs) {1347if(!is_nonbare_repository_dir(&submodule)) {1348strbuf_release(&submodule);1349return-1;1350}1351 refs =create_ref_cache(submodule.buf);1352}1353strbuf_release(&submodule);13541355 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1356return retval;1357}13581359/*1360 * Return the ref_entry for the given refname from the packed1361 * references. If it does not exist, return NULL.1362 */1363static struct ref_entry *get_packed_ref(const char*refname)1364{1365returnfind_ref(get_packed_refs(&ref_cache), refname);1366}13671368/*1369 * A loose ref file doesn't exist; check for a packed ref.1370 */1371static intresolve_missing_loose_ref(const char*refname,1372unsigned char*sha1,1373unsigned int*flags)1374{1375struct ref_entry *entry;13761377/*1378 * The loose reference file does not exist; check for a packed1379 * reference.1380 */1381 entry =get_packed_ref(refname);1382if(entry) {1383hashcpy(sha1, entry->u.value.oid.hash);1384*flags |= REF_ISPACKED;1385return0;1386}1387/* refname is not a packed reference. */1388return-1;1389}13901391/*1392 * Read a raw ref from the filesystem or packed refs file.1393 *1394 * If the ref is a sha1, fill in sha1 and return 0.1395 *1396 * If the ref is symbolic, fill in *symref with the referrent1397 * (e.g. "refs/heads/master") and return 0. The caller is responsible1398 * for validating the referrent. Set REF_ISSYMREF in type.1399 *1400 * If the ref doesn't exist, set errno to ENOENT and return -1.1401 *1402 * If the ref exists but is neither a symbolic ref nor a sha1, it is1403 * broken. Set REF_ISBROKEN in type, set errno to EINVAL, and return1404 * -1.1405 *1406 * If there is another error reading the ref, set errno appropriately and1407 * return -1.1408 *1409 * Backend-specific flags might be set in type as well, regardless of1410 * outcome.1411 *1412 * sb_path is workspace: the caller should allocate and free it.1413 *1414 * It is OK for refname to point into symref. In this case:1415 * - if the function succeeds with REF_ISSYMREF, symref will be1416 * overwritten and the memory pointed to by refname might be changed1417 * or even freed.1418 * - in all other cases, symref will be untouched, and therefore1419 * refname will still be valid and unchanged.1420 */1421intread_raw_ref(const char*refname,unsigned char*sha1,1422struct strbuf *symref,unsigned int*type)1423{1424struct strbuf sb_contents = STRBUF_INIT;1425struct strbuf sb_path = STRBUF_INIT;1426const char*path;1427const char*buf;1428struct stat st;1429int fd;1430int ret = -1;1431int save_errno;14321433*type =0;1434strbuf_reset(&sb_path);1435strbuf_git_path(&sb_path,"%s", refname);1436 path = sb_path.buf;14371438stat_ref:1439/*1440 * We might have to loop back here to avoid a race1441 * condition: first we lstat() the file, then we try1442 * to read it as a link or as a file. But if somebody1443 * changes the type of the file (file <-> directory1444 * <-> symlink) between the lstat() and reading, then1445 * we don't want to report that as an error but rather1446 * try again starting with the lstat().1447 */14481449if(lstat(path, &st) <0) {1450if(errno != ENOENT)1451goto out;1452if(resolve_missing_loose_ref(refname, sha1, type)) {1453 errno = ENOENT;1454goto out;1455}1456 ret =0;1457goto out;1458}14591460/* Follow "normalized" - ie "refs/.." symlinks by hand */1461if(S_ISLNK(st.st_mode)) {1462strbuf_reset(&sb_contents);1463if(strbuf_readlink(&sb_contents, path,0) <0) {1464if(errno == ENOENT || errno == EINVAL)1465/* inconsistent with lstat; retry */1466goto stat_ref;1467else1468goto out;1469}1470if(starts_with(sb_contents.buf,"refs/") &&1471!check_refname_format(sb_contents.buf,0)) {1472strbuf_swap(&sb_contents, symref);1473*type |= REF_ISSYMREF;1474 ret =0;1475goto out;1476}1477}14781479/* Is it a directory? */1480if(S_ISDIR(st.st_mode)) {1481/*1482 * Even though there is a directory where the loose1483 * ref is supposed to be, there could still be a1484 * packed ref:1485 */1486if(resolve_missing_loose_ref(refname, sha1, type)) {1487 errno = EISDIR;1488goto out;1489}1490 ret =0;1491goto out;1492}14931494/*1495 * Anything else, just open it and try to use it as1496 * a ref1497 */1498 fd =open(path, O_RDONLY);1499if(fd <0) {1500if(errno == ENOENT)1501/* inconsistent with lstat; retry */1502goto stat_ref;1503else1504goto out;1505}1506strbuf_reset(&sb_contents);1507if(strbuf_read(&sb_contents, fd,256) <0) {1508int save_errno = errno;1509close(fd);1510 errno = save_errno;1511goto out;1512}1513close(fd);1514strbuf_rtrim(&sb_contents);1515 buf = sb_contents.buf;1516if(starts_with(buf,"ref:")) {1517 buf +=4;1518while(isspace(*buf))1519 buf++;15201521strbuf_reset(symref);1522strbuf_addstr(symref, buf);1523*type |= REF_ISSYMREF;1524 ret =0;1525goto out;1526}15271528/*1529 * Please note that FETCH_HEAD has additional1530 * data after the sha.1531 */1532if(get_sha1_hex(buf, sha1) ||1533(buf[40] !='\0'&& !isspace(buf[40]))) {1534*type |= REF_ISBROKEN;1535 errno = EINVAL;1536goto out;1537}15381539 ret =0;15401541out:1542 save_errno = errno;1543strbuf_release(&sb_path);1544strbuf_release(&sb_contents);1545 errno = save_errno;1546return ret;1547}15481549/*1550 * Peel the entry (if possible) and return its new peel_status. If1551 * repeel is true, re-peel the entry even if there is an old peeled1552 * value that is already stored in it.1553 *1554 * It is OK to call this function with a packed reference entry that1555 * might be stale and might even refer to an object that has since1556 * been garbage-collected. In such a case, if the entry has1557 * REF_KNOWS_PEELED then leave the status unchanged and return1558 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1559 */1560static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1561{1562enum peel_status status;15631564if(entry->flag & REF_KNOWS_PEELED) {1565if(repeel) {1566 entry->flag &= ~REF_KNOWS_PEELED;1567oidclr(&entry->u.value.peeled);1568}else{1569returnis_null_oid(&entry->u.value.peeled) ?1570 PEEL_NON_TAG : PEEL_PEELED;1571}1572}1573if(entry->flag & REF_ISBROKEN)1574return PEEL_BROKEN;1575if(entry->flag & REF_ISSYMREF)1576return PEEL_IS_SYMREF;15771578 status =peel_object(entry->u.value.oid.hash, entry->u.value.peeled.hash);1579if(status == PEEL_PEELED || status == PEEL_NON_TAG)1580 entry->flag |= REF_KNOWS_PEELED;1581return status;1582}15831584intpeel_ref(const char*refname,unsigned char*sha1)1585{1586int flag;1587unsigned char base[20];15881589if(current_ref && (current_ref->name == refname1590|| !strcmp(current_ref->name, refname))) {1591if(peel_entry(current_ref,0))1592return-1;1593hashcpy(sha1, current_ref->u.value.peeled.hash);1594return0;1595}15961597if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1598return-1;15991600/*1601 * If the reference is packed, read its ref_entry from the1602 * cache in the hope that we already know its peeled value.1603 * We only try this optimization on packed references because1604 * (a) forcing the filling of the loose reference cache could1605 * be expensive and (b) loose references anyway usually do not1606 * have REF_KNOWS_PEELED.1607 */1608if(flag & REF_ISPACKED) {1609struct ref_entry *r =get_packed_ref(refname);1610if(r) {1611if(peel_entry(r,0))1612return-1;1613hashcpy(sha1, r->u.value.peeled.hash);1614return0;1615}1616}16171618returnpeel_object(base, sha1);1619}16201621/*1622 * Call fn for each reference in the specified ref_cache, omitting1623 * references not in the containing_dir of base. fn is called for all1624 * references, including broken ones. If fn ever returns a non-zero1625 * value, stop the iteration and return that value; otherwise, return1626 * 0.1627 */1628static intdo_for_each_entry(struct ref_cache *refs,const char*base,1629 each_ref_entry_fn fn,void*cb_data)1630{1631struct packed_ref_cache *packed_ref_cache;1632struct ref_dir *loose_dir;1633struct ref_dir *packed_dir;1634int retval =0;16351636/*1637 * We must make sure that all loose refs are read before accessing the1638 * packed-refs file; this avoids a race condition in which loose refs1639 * are migrated to the packed-refs file by a simultaneous process, but1640 * our in-memory view is from before the migration. get_packed_ref_cache()1641 * takes care of making sure our view is up to date with what is on1642 * disk.1643 */1644 loose_dir =get_loose_refs(refs);1645if(base && *base) {1646 loose_dir =find_containing_dir(loose_dir, base,0);1647}1648if(loose_dir)1649prime_ref_dir(loose_dir);16501651 packed_ref_cache =get_packed_ref_cache(refs);1652acquire_packed_ref_cache(packed_ref_cache);1653 packed_dir =get_packed_ref_dir(packed_ref_cache);1654if(base && *base) {1655 packed_dir =find_containing_dir(packed_dir, base,0);1656}16571658if(packed_dir && loose_dir) {1659sort_ref_dir(packed_dir);1660sort_ref_dir(loose_dir);1661 retval =do_for_each_entry_in_dirs(1662 packed_dir, loose_dir, fn, cb_data);1663}else if(packed_dir) {1664sort_ref_dir(packed_dir);1665 retval =do_for_each_entry_in_dir(1666 packed_dir,0, fn, cb_data);1667}else if(loose_dir) {1668sort_ref_dir(loose_dir);1669 retval =do_for_each_entry_in_dir(1670 loose_dir,0, fn, cb_data);1671}16721673release_packed_ref_cache(packed_ref_cache);1674return retval;1675}16761677/*1678 * Call fn for each reference in the specified ref_cache for which the1679 * refname begins with base. If trim is non-zero, then trim that many1680 * characters off the beginning of each refname before passing the1681 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1682 * broken references in the iteration. If fn ever returns a non-zero1683 * value, stop the iteration and return that value; otherwise, return1684 * 0.1685 */1686intdo_for_each_ref(const char*submodule,const char*base,1687 each_ref_fn fn,int trim,int flags,void*cb_data)1688{1689struct ref_entry_cb data;1690struct ref_cache *refs;16911692 refs =get_ref_cache(submodule);1693 data.base = base;1694 data.trim = trim;1695 data.flags = flags;1696 data.fn = fn;1697 data.cb_data = cb_data;16981699if(ref_paranoia <0)1700 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1701if(ref_paranoia)1702 data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;17031704returndo_for_each_entry(refs, base, do_one_ref, &data);1705}17061707static voidunlock_ref(struct ref_lock *lock)1708{1709/* Do not free lock->lk -- atexit() still looks at them */1710if(lock->lk)1711rollback_lock_file(lock->lk);1712free(lock->ref_name);1713free(lock->orig_ref_name);1714free(lock);1715}17161717/*1718 * Verify that the reference locked by lock has the value old_sha1.1719 * Fail if the reference doesn't exist and mustexist is set. Return 01720 * on success. On error, write an error message to err, set errno, and1721 * return a negative value.1722 */1723static intverify_lock(struct ref_lock *lock,1724const unsigned char*old_sha1,int mustexist,1725struct strbuf *err)1726{1727assert(err);17281729if(read_ref_full(lock->ref_name,1730 mustexist ? RESOLVE_REF_READING :0,1731 lock->old_oid.hash, NULL)) {1732if(old_sha1) {1733int save_errno = errno;1734strbuf_addf(err,"can't verify ref%s", lock->ref_name);1735 errno = save_errno;1736return-1;1737}else{1738hashclr(lock->old_oid.hash);1739return0;1740}1741}1742if(old_sha1 &&hashcmp(lock->old_oid.hash, old_sha1)) {1743strbuf_addf(err,"ref%sis at%sbut expected%s",1744 lock->ref_name,1745sha1_to_hex(lock->old_oid.hash),1746sha1_to_hex(old_sha1));1747 errno = EBUSY;1748return-1;1749}1750return0;1751}17521753static intremove_empty_directories(struct strbuf *path)1754{1755/*1756 * we want to create a file but there is a directory there;1757 * if that is an empty directory (or a directory that contains1758 * only empty directories), remove them.1759 */1760returnremove_dir_recursively(path, REMOVE_DIR_EMPTY_ONLY);1761}17621763/*1764 * Locks a ref returning the lock on success and NULL on failure.1765 * On failure errno is set to something meaningful.1766 */1767static struct ref_lock *lock_ref_sha1_basic(const char*refname,1768const unsigned char*old_sha1,1769const struct string_list *extras,1770const struct string_list *skip,1771unsigned int flags,int*type_p,1772struct strbuf *err)1773{1774struct strbuf ref_file = STRBUF_INIT;1775struct strbuf orig_ref_file = STRBUF_INIT;1776const char*orig_refname = refname;1777struct ref_lock *lock;1778int last_errno =0;1779int type;1780int lflags =0;1781int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1782int resolve_flags =0;1783int attempts_remaining =3;17841785assert(err);17861787 lock =xcalloc(1,sizeof(struct ref_lock));17881789if(mustexist)1790 resolve_flags |= RESOLVE_REF_READING;1791if(flags & REF_DELETING)1792 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;1793if(flags & REF_NODEREF) {1794 resolve_flags |= RESOLVE_REF_NO_RECURSE;1795 lflags |= LOCK_NO_DEREF;1796}17971798 refname =resolve_ref_unsafe(refname, resolve_flags,1799 lock->old_oid.hash, &type);1800if(!refname && errno == EISDIR) {1801/*1802 * we are trying to lock foo but we used to1803 * have foo/bar which now does not exist;1804 * it is normal for the empty directory 'foo'1805 * to remain.1806 */1807strbuf_git_path(&orig_ref_file,"%s", orig_refname);1808if(remove_empty_directories(&orig_ref_file)) {1809 last_errno = errno;1810if(!verify_refname_available_dir(orig_refname, extras, skip,1811get_loose_refs(&ref_cache), err))1812strbuf_addf(err,"there are still refs under '%s'",1813 orig_refname);1814goto error_return;1815}1816 refname =resolve_ref_unsafe(orig_refname, resolve_flags,1817 lock->old_oid.hash, &type);1818}1819if(type_p)1820*type_p = type;1821if(!refname) {1822 last_errno = errno;1823if(last_errno != ENOTDIR ||1824!verify_refname_available_dir(orig_refname, extras, skip,1825get_loose_refs(&ref_cache), err))1826strbuf_addf(err,"unable to resolve reference%s:%s",1827 orig_refname,strerror(last_errno));18281829goto error_return;1830}18311832if(flags & REF_NODEREF)1833 refname = orig_refname;18341835/*1836 * If the ref did not exist and we are creating it, make sure1837 * there is no existing packed ref whose name begins with our1838 * refname, nor a packed ref whose name is a proper prefix of1839 * our refname.1840 */1841if(is_null_oid(&lock->old_oid) &&1842verify_refname_available_dir(refname, extras, skip,1843get_packed_refs(&ref_cache), err)) {1844 last_errno = ENOTDIR;1845goto error_return;1846}18471848 lock->lk =xcalloc(1,sizeof(struct lock_file));18491850 lock->ref_name =xstrdup(refname);1851 lock->orig_ref_name =xstrdup(orig_refname);1852strbuf_git_path(&ref_file,"%s", refname);18531854 retry:1855switch(safe_create_leading_directories_const(ref_file.buf)) {1856case SCLD_OK:1857break;/* success */1858case SCLD_VANISHED:1859if(--attempts_remaining >0)1860goto retry;1861/* fall through */1862default:1863 last_errno = errno;1864strbuf_addf(err,"unable to create directory for%s",1865 ref_file.buf);1866goto error_return;1867}18681869if(hold_lock_file_for_update(lock->lk, ref_file.buf, lflags) <0) {1870 last_errno = errno;1871if(errno == ENOENT && --attempts_remaining >0)1872/*1873 * Maybe somebody just deleted one of the1874 * directories leading to ref_file. Try1875 * again:1876 */1877goto retry;1878else{1879unable_to_lock_message(ref_file.buf, errno, err);1880goto error_return;1881}1882}1883if(verify_lock(lock, old_sha1, mustexist, err)) {1884 last_errno = errno;1885goto error_return;1886}1887goto out;18881889 error_return:1890unlock_ref(lock);1891 lock = NULL;18921893 out:1894strbuf_release(&ref_file);1895strbuf_release(&orig_ref_file);1896 errno = last_errno;1897return lock;1898}18991900/*1901 * Write an entry to the packed-refs file for the specified refname.1902 * If peeled is non-NULL, write it as the entry's peeled value.1903 */1904static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,1905unsigned char*peeled)1906{1907fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);1908if(peeled)1909fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));1910}19111912/*1913 * An each_ref_entry_fn that writes the entry to a packed-refs file.1914 */1915static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)1916{1917enum peel_status peel_status =peel_entry(entry,0);19181919if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)1920error("internal error:%sis not a valid packed reference!",1921 entry->name);1922write_packed_entry(cb_data, entry->name, entry->u.value.oid.hash,1923 peel_status == PEEL_PEELED ?1924 entry->u.value.peeled.hash : NULL);1925return0;1926}19271928/*1929 * Lock the packed-refs file for writing. Flags is passed to1930 * hold_lock_file_for_update(). Return 0 on success. On errors, set1931 * errno appropriately and return a nonzero value.1932 */1933static intlock_packed_refs(int flags)1934{1935static int timeout_configured =0;1936static int timeout_value =1000;19371938struct packed_ref_cache *packed_ref_cache;19391940if(!timeout_configured) {1941git_config_get_int("core.packedrefstimeout", &timeout_value);1942 timeout_configured =1;1943}19441945if(hold_lock_file_for_update_timeout(1946&packlock,git_path("packed-refs"),1947 flags, timeout_value) <0)1948return-1;1949/*1950 * Get the current packed-refs while holding the lock. If the1951 * packed-refs file has been modified since we last read it,1952 * this will automatically invalidate the cache and re-read1953 * the packed-refs file.1954 */1955 packed_ref_cache =get_packed_ref_cache(&ref_cache);1956 packed_ref_cache->lock = &packlock;1957/* Increment the reference count to prevent it from being freed: */1958acquire_packed_ref_cache(packed_ref_cache);1959return0;1960}19611962/*1963 * Write the current version of the packed refs cache from memory to1964 * disk. The packed-refs file must already be locked for writing (see1965 * lock_packed_refs()). Return zero on success. On errors, set errno1966 * and return a nonzero value1967 */1968static intcommit_packed_refs(void)1969{1970struct packed_ref_cache *packed_ref_cache =1971get_packed_ref_cache(&ref_cache);1972int error =0;1973int save_errno =0;1974FILE*out;19751976if(!packed_ref_cache->lock)1977die("internal error: packed-refs not locked");19781979 out =fdopen_lock_file(packed_ref_cache->lock,"w");1980if(!out)1981die_errno("unable to fdopen packed-refs descriptor");19821983fprintf_or_die(out,"%s", PACKED_REFS_HEADER);1984do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),19850, write_packed_entry_fn, out);19861987if(commit_lock_file(packed_ref_cache->lock)) {1988 save_errno = errno;1989 error = -1;1990}1991 packed_ref_cache->lock = NULL;1992release_packed_ref_cache(packed_ref_cache);1993 errno = save_errno;1994return error;1995}19961997/*1998 * Rollback the lockfile for the packed-refs file, and discard the1999 * in-memory packed reference cache. (The packed-refs file will be2000 * read anew if it is needed again after this function is called.)2001 */2002static voidrollback_packed_refs(void)2003{2004struct packed_ref_cache *packed_ref_cache =2005get_packed_ref_cache(&ref_cache);20062007if(!packed_ref_cache->lock)2008die("internal error: packed-refs not locked");2009rollback_lock_file(packed_ref_cache->lock);2010 packed_ref_cache->lock = NULL;2011release_packed_ref_cache(packed_ref_cache);2012clear_packed_ref_cache(&ref_cache);2013}20142015struct ref_to_prune {2016struct ref_to_prune *next;2017unsigned char sha1[20];2018char name[FLEX_ARRAY];2019};20202021struct pack_refs_cb_data {2022unsigned int flags;2023struct ref_dir *packed_refs;2024struct ref_to_prune *ref_to_prune;2025};20262027/*2028 * An each_ref_entry_fn that is run over loose references only. If2029 * the loose reference can be packed, add an entry in the packed ref2030 * cache. If the reference should be pruned, also add it to2031 * ref_to_prune in the pack_refs_cb_data.2032 */2033static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2034{2035struct pack_refs_cb_data *cb = cb_data;2036enum peel_status peel_status;2037struct ref_entry *packed_entry;2038int is_tag_ref =starts_with(entry->name,"refs/tags/");20392040/* Do not pack per-worktree refs: */2041if(ref_type(entry->name) != REF_TYPE_NORMAL)2042return0;20432044/* ALWAYS pack tags */2045if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2046return0;20472048/* Do not pack symbolic or broken refs: */2049if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2050return0;20512052/* Add a packed ref cache entry equivalent to the loose entry. */2053 peel_status =peel_entry(entry,1);2054if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2055die("internal error peeling reference%s(%s)",2056 entry->name,oid_to_hex(&entry->u.value.oid));2057 packed_entry =find_ref(cb->packed_refs, entry->name);2058if(packed_entry) {2059/* Overwrite existing packed entry with info from loose entry */2060 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2061oidcpy(&packed_entry->u.value.oid, &entry->u.value.oid);2062}else{2063 packed_entry =create_ref_entry(entry->name, entry->u.value.oid.hash,2064 REF_ISPACKED | REF_KNOWS_PEELED,0);2065add_ref(cb->packed_refs, packed_entry);2066}2067oidcpy(&packed_entry->u.value.peeled, &entry->u.value.peeled);20682069/* Schedule the loose reference for pruning if requested. */2070if((cb->flags & PACK_REFS_PRUNE)) {2071struct ref_to_prune *n;2072FLEX_ALLOC_STR(n, name, entry->name);2073hashcpy(n->sha1, entry->u.value.oid.hash);2074 n->next = cb->ref_to_prune;2075 cb->ref_to_prune = n;2076}2077return0;2078}20792080/*2081 * Remove empty parents, but spare refs/ and immediate subdirs.2082 * Note: munges *name.2083 */2084static voidtry_remove_empty_parents(char*name)2085{2086char*p, *q;2087int i;2088 p = name;2089for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2090while(*p && *p !='/')2091 p++;2092/* tolerate duplicate slashes; see check_refname_format() */2093while(*p =='/')2094 p++;2095}2096for(q = p; *q; q++)2097;2098while(1) {2099while(q > p && *q !='/')2100 q--;2101while(q > p && *(q-1) =='/')2102 q--;2103if(q == p)2104break;2105*q ='\0';2106if(rmdir(git_path("%s", name)))2107break;2108}2109}21102111/* make sure nobody touched the ref, and unlink */2112static voidprune_ref(struct ref_to_prune *r)2113{2114struct ref_transaction *transaction;2115struct strbuf err = STRBUF_INIT;21162117if(check_refname_format(r->name,0))2118return;21192120 transaction =ref_transaction_begin(&err);2121if(!transaction ||2122ref_transaction_delete(transaction, r->name, r->sha1,2123 REF_ISPRUNING, NULL, &err) ||2124ref_transaction_commit(transaction, &err)) {2125ref_transaction_free(transaction);2126error("%s", err.buf);2127strbuf_release(&err);2128return;2129}2130ref_transaction_free(transaction);2131strbuf_release(&err);2132try_remove_empty_parents(r->name);2133}21342135static voidprune_refs(struct ref_to_prune *r)2136{2137while(r) {2138prune_ref(r);2139 r = r->next;2140}2141}21422143intpack_refs(unsigned int flags)2144{2145struct pack_refs_cb_data cbdata;21462147memset(&cbdata,0,sizeof(cbdata));2148 cbdata.flags = flags;21492150lock_packed_refs(LOCK_DIE_ON_ERROR);2151 cbdata.packed_refs =get_packed_refs(&ref_cache);21522153do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2154 pack_if_possible_fn, &cbdata);21552156if(commit_packed_refs())2157die_errno("unable to overwrite old ref-pack file");21582159prune_refs(cbdata.ref_to_prune);2160return0;2161}21622163/*2164 * Rewrite the packed-refs file, omitting any refs listed in2165 * 'refnames'. On error, leave packed-refs unchanged, write an error2166 * message to 'err', and return a nonzero value.2167 *2168 * The refs in 'refnames' needn't be sorted. `err` must not be NULL.2169 */2170static intrepack_without_refs(struct string_list *refnames,struct strbuf *err)2171{2172struct ref_dir *packed;2173struct string_list_item *refname;2174int ret, needs_repacking =0, removed =0;21752176assert(err);21772178/* Look for a packed ref */2179for_each_string_list_item(refname, refnames) {2180if(get_packed_ref(refname->string)) {2181 needs_repacking =1;2182break;2183}2184}21852186/* Avoid locking if we have nothing to do */2187if(!needs_repacking)2188return0;/* no refname exists in packed refs */21892190if(lock_packed_refs(0)) {2191unable_to_lock_message(git_path("packed-refs"), errno, err);2192return-1;2193}2194 packed =get_packed_refs(&ref_cache);21952196/* Remove refnames from the cache */2197for_each_string_list_item(refname, refnames)2198if(remove_entry(packed, refname->string) != -1)2199 removed =1;2200if(!removed) {2201/*2202 * All packed entries disappeared while we were2203 * acquiring the lock.2204 */2205rollback_packed_refs();2206return0;2207}22082209/* Write what remains */2210 ret =commit_packed_refs();2211if(ret)2212strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2213strerror(errno));2214return ret;2215}22162217static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2218{2219assert(err);22202221if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2222/*2223 * loose. The loose file name is the same as the2224 * lockfile name, minus ".lock":2225 */2226char*loose_filename =get_locked_file_path(lock->lk);2227int res =unlink_or_msg(loose_filename, err);2228free(loose_filename);2229if(res)2230return1;2231}2232return0;2233}22342235intdelete_refs(struct string_list *refnames)2236{2237struct strbuf err = STRBUF_INIT;2238int i, result =0;22392240if(!refnames->nr)2241return0;22422243 result =repack_without_refs(refnames, &err);2244if(result) {2245/*2246 * If we failed to rewrite the packed-refs file, then2247 * it is unsafe to try to remove loose refs, because2248 * doing so might expose an obsolete packed value for2249 * a reference that might even point at an object that2250 * has been garbage collected.2251 */2252if(refnames->nr ==1)2253error(_("could not delete reference%s:%s"),2254 refnames->items[0].string, err.buf);2255else2256error(_("could not delete references:%s"), err.buf);22572258goto out;2259}22602261for(i =0; i < refnames->nr; i++) {2262const char*refname = refnames->items[i].string;22632264if(delete_ref(refname, NULL,0))2265 result |=error(_("could not remove reference%s"), refname);2266}22672268out:2269strbuf_release(&err);2270return result;2271}22722273/*2274 * People using contrib's git-new-workdir have .git/logs/refs ->2275 * /some/other/path/.git/logs/refs, and that may live on another device.2276 *2277 * IOW, to avoid cross device rename errors, the temporary renamed log must2278 * live into logs/refs.2279 */2280#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"22812282static intrename_tmp_log(const char*newrefname)2283{2284int attempts_remaining =4;2285struct strbuf path = STRBUF_INIT;2286int ret = -1;22872288 retry:2289strbuf_reset(&path);2290strbuf_git_path(&path,"logs/%s", newrefname);2291switch(safe_create_leading_directories_const(path.buf)) {2292case SCLD_OK:2293break;/* success */2294case SCLD_VANISHED:2295if(--attempts_remaining >0)2296goto retry;2297/* fall through */2298default:2299error("unable to create directory for%s", newrefname);2300goto out;2301}23022303if(rename(git_path(TMP_RENAMED_LOG), path.buf)) {2304if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2305/*2306 * rename(a, b) when b is an existing2307 * directory ought to result in ISDIR, but2308 * Solaris 5.8 gives ENOTDIR. Sheesh.2309 */2310if(remove_empty_directories(&path)) {2311error("Directory not empty: logs/%s", newrefname);2312goto out;2313}2314goto retry;2315}else if(errno == ENOENT && --attempts_remaining >0) {2316/*2317 * Maybe another process just deleted one of2318 * the directories in the path to newrefname.2319 * Try again from the beginning.2320 */2321goto retry;2322}else{2323error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2324 newrefname,strerror(errno));2325goto out;2326}2327}2328 ret =0;2329out:2330strbuf_release(&path);2331return ret;2332}23332334intverify_refname_available(const char*newname,2335struct string_list *extras,2336struct string_list *skip,2337struct strbuf *err)2338{2339struct ref_dir *packed_refs =get_packed_refs(&ref_cache);2340struct ref_dir *loose_refs =get_loose_refs(&ref_cache);23412342if(verify_refname_available_dir(newname, extras, skip,2343 packed_refs, err) ||2344verify_refname_available_dir(newname, extras, skip,2345 loose_refs, err))2346return-1;23472348return0;2349}23502351static intwrite_ref_to_lockfile(struct ref_lock *lock,2352const unsigned char*sha1,struct strbuf *err);2353static intcommit_ref_update(struct ref_lock *lock,2354const unsigned char*sha1,const char*logmsg,2355int flags,struct strbuf *err);23562357intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2358{2359unsigned char sha1[20], orig_sha1[20];2360int flag =0, logmoved =0;2361struct ref_lock *lock;2362struct stat loginfo;2363int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2364struct strbuf err = STRBUF_INIT;23652366if(log &&S_ISLNK(loginfo.st_mode))2367returnerror("reflog for%sis a symlink", oldrefname);23682369if(!resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING, orig_sha1, &flag))2370returnerror("refname%snot found", oldrefname);23712372if(flag & REF_ISSYMREF)2373returnerror("refname%sis a symbolic ref, renaming it is not supported",2374 oldrefname);2375if(!rename_ref_available(oldrefname, newrefname))2376return1;23772378if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2379returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2380 oldrefname,strerror(errno));23812382if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2383error("unable to delete old%s", oldrefname);2384goto rollback;2385}23862387if(!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2388delete_ref(newrefname, sha1, REF_NODEREF)) {2389if(errno==EISDIR) {2390struct strbuf path = STRBUF_INIT;2391int result;23922393strbuf_git_path(&path,"%s", newrefname);2394 result =remove_empty_directories(&path);2395strbuf_release(&path);23962397if(result) {2398error("Directory not empty:%s", newrefname);2399goto rollback;2400}2401}else{2402error("unable to delete existing%s", newrefname);2403goto rollback;2404}2405}24062407if(log &&rename_tmp_log(newrefname))2408goto rollback;24092410 logmoved = log;24112412 lock =lock_ref_sha1_basic(newrefname, NULL, NULL, NULL,0, NULL, &err);2413if(!lock) {2414error("unable to rename '%s' to '%s':%s", oldrefname, newrefname, err.buf);2415strbuf_release(&err);2416goto rollback;2417}2418hashcpy(lock->old_oid.hash, orig_sha1);24192420if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2421commit_ref_update(lock, orig_sha1, logmsg,0, &err)) {2422error("unable to write current sha1 into%s:%s", newrefname, err.buf);2423strbuf_release(&err);2424goto rollback;2425}24262427return0;24282429 rollback:2430 lock =lock_ref_sha1_basic(oldrefname, NULL, NULL, NULL,0, NULL, &err);2431if(!lock) {2432error("unable to lock%sfor rollback:%s", oldrefname, err.buf);2433strbuf_release(&err);2434goto rollbacklog;2435}24362437 flag = log_all_ref_updates;2438 log_all_ref_updates =0;2439if(write_ref_to_lockfile(lock, orig_sha1, &err) ||2440commit_ref_update(lock, orig_sha1, NULL,0, &err)) {2441error("unable to write current sha1 into%s:%s", oldrefname, err.buf);2442strbuf_release(&err);2443}2444 log_all_ref_updates = flag;24452446 rollbacklog:2447if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2448error("unable to restore logfile%sfrom%s:%s",2449 oldrefname, newrefname,strerror(errno));2450if(!logmoved && log &&2451rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2452error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2453 oldrefname,strerror(errno));24542455return1;2456}24572458static intclose_ref(struct ref_lock *lock)2459{2460if(close_lock_file(lock->lk))2461return-1;2462return0;2463}24642465static intcommit_ref(struct ref_lock *lock)2466{2467char*path =get_locked_file_path(lock->lk);2468struct stat st;24692470if(!lstat(path, &st) &&S_ISDIR(st.st_mode)) {2471/*2472 * There is a directory at the path we want to rename2473 * the lockfile to. Hopefully it is empty; try to2474 * delete it.2475 */2476size_t len =strlen(path);2477struct strbuf sb_path = STRBUF_INIT;24782479strbuf_attach(&sb_path, path, len, len);24802481/*2482 * If this fails, commit_lock_file() will also fail2483 * and will report the problem.2484 */2485remove_empty_directories(&sb_path);2486strbuf_release(&sb_path);2487}else{2488free(path);2489}24902491if(commit_lock_file(lock->lk))2492return-1;2493return0;2494}24952496/*2497 * Create a reflog for a ref. If force_create = 0, the reflog will2498 * only be created for certain refs (those for which2499 * should_autocreate_reflog returns non-zero. Otherwise, create it2500 * regardless of the ref name. Fill in *err and return -1 on failure.2501 */2502static intlog_ref_setup(const char*refname,struct strbuf *logfile,struct strbuf *err,int force_create)2503{2504int logfd, oflags = O_APPEND | O_WRONLY;25052506strbuf_git_path(logfile,"logs/%s", refname);2507if(force_create ||should_autocreate_reflog(refname)) {2508if(safe_create_leading_directories(logfile->buf) <0) {2509strbuf_addf(err,"unable to create directory for%s: "2510"%s", logfile->buf,strerror(errno));2511return-1;2512}2513 oflags |= O_CREAT;2514}25152516 logfd =open(logfile->buf, oflags,0666);2517if(logfd <0) {2518if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2519return0;25202521if(errno == EISDIR) {2522if(remove_empty_directories(logfile)) {2523strbuf_addf(err,"There are still logs under "2524"'%s'", logfile->buf);2525return-1;2526}2527 logfd =open(logfile->buf, oflags,0666);2528}25292530if(logfd <0) {2531strbuf_addf(err,"unable to append to%s:%s",2532 logfile->buf,strerror(errno));2533return-1;2534}2535}25362537adjust_shared_perm(logfile->buf);2538close(logfd);2539return0;2540}254125422543intsafe_create_reflog(const char*refname,int force_create,struct strbuf *err)2544{2545int ret;2546struct strbuf sb = STRBUF_INIT;25472548 ret =log_ref_setup(refname, &sb, err, force_create);2549strbuf_release(&sb);2550return ret;2551}25522553static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2554const unsigned char*new_sha1,2555const char*committer,const char*msg)2556{2557int msglen, written;2558unsigned maxlen, len;2559char*logrec;25602561 msglen = msg ?strlen(msg) :0;2562 maxlen =strlen(committer) + msglen +100;2563 logrec =xmalloc(maxlen);2564 len =xsnprintf(logrec, maxlen,"%s %s %s\n",2565sha1_to_hex(old_sha1),2566sha1_to_hex(new_sha1),2567 committer);2568if(msglen)2569 len +=copy_reflog_msg(logrec + len -1, msg) -1;25702571 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;2572free(logrec);2573if(written != len)2574return-1;25752576return0;2577}25782579static intlog_ref_write_1(const char*refname,const unsigned char*old_sha1,2580const unsigned char*new_sha1,const char*msg,2581struct strbuf *logfile,int flags,2582struct strbuf *err)2583{2584int logfd, result, oflags = O_APPEND | O_WRONLY;25852586if(log_all_ref_updates <0)2587 log_all_ref_updates = !is_bare_repository();25882589 result =log_ref_setup(refname, logfile, err, flags & REF_FORCE_CREATE_REFLOG);25902591if(result)2592return result;25932594 logfd =open(logfile->buf, oflags);2595if(logfd <0)2596return0;2597 result =log_ref_write_fd(logfd, old_sha1, new_sha1,2598git_committer_info(0), msg);2599if(result) {2600strbuf_addf(err,"unable to append to%s:%s", logfile->buf,2601strerror(errno));2602close(logfd);2603return-1;2604}2605if(close(logfd)) {2606strbuf_addf(err,"unable to append to%s:%s", logfile->buf,2607strerror(errno));2608return-1;2609}2610return0;2611}26122613static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2614const unsigned char*new_sha1,const char*msg,2615int flags,struct strbuf *err)2616{2617returnfiles_log_ref_write(refname, old_sha1, new_sha1, msg, flags,2618 err);2619}26202621intfiles_log_ref_write(const char*refname,const unsigned char*old_sha1,2622const unsigned char*new_sha1,const char*msg,2623int flags,struct strbuf *err)2624{2625struct strbuf sb = STRBUF_INIT;2626int ret =log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb, flags,2627 err);2628strbuf_release(&sb);2629return ret;2630}26312632/*2633 * Write sha1 into the open lockfile, then close the lockfile. On2634 * errors, rollback the lockfile, fill in *err and2635 * return -1.2636 */2637static intwrite_ref_to_lockfile(struct ref_lock *lock,2638const unsigned char*sha1,struct strbuf *err)2639{2640static char term ='\n';2641struct object *o;2642int fd;26432644 o =parse_object(sha1);2645if(!o) {2646strbuf_addf(err,2647"Trying to write ref%swith nonexistent object%s",2648 lock->ref_name,sha1_to_hex(sha1));2649unlock_ref(lock);2650return-1;2651}2652if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2653strbuf_addf(err,2654"Trying to write non-commit object%sto branch%s",2655sha1_to_hex(sha1), lock->ref_name);2656unlock_ref(lock);2657return-1;2658}2659 fd =get_lock_file_fd(lock->lk);2660if(write_in_full(fd,sha1_to_hex(sha1),40) !=40||2661write_in_full(fd, &term,1) !=1||2662close_ref(lock) <0) {2663strbuf_addf(err,2664"Couldn't write%s",get_lock_file_path(lock->lk));2665unlock_ref(lock);2666return-1;2667}2668return0;2669}26702671/*2672 * Commit a change to a loose reference that has already been written2673 * to the loose reference lockfile. Also update the reflogs if2674 * necessary, using the specified lockmsg (which can be NULL).2675 */2676static intcommit_ref_update(struct ref_lock *lock,2677const unsigned char*sha1,const char*logmsg,2678int flags,struct strbuf *err)2679{2680clear_loose_ref_cache(&ref_cache);2681if(log_ref_write(lock->ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) <0||2682(strcmp(lock->ref_name, lock->orig_ref_name) &&2683log_ref_write(lock->orig_ref_name, lock->old_oid.hash, sha1, logmsg, flags, err) <0)) {2684char*old_msg =strbuf_detach(err, NULL);2685strbuf_addf(err,"Cannot update the ref '%s':%s",2686 lock->ref_name, old_msg);2687free(old_msg);2688unlock_ref(lock);2689return-1;2690}2691if(strcmp(lock->orig_ref_name,"HEAD") !=0) {2692/*2693 * Special hack: If a branch is updated directly and HEAD2694 * points to it (may happen on the remote side of a push2695 * for example) then logically the HEAD reflog should be2696 * updated too.2697 * A generic solution implies reverse symref information,2698 * but finding all symrefs pointing to the given branch2699 * would be rather costly for this rare event (the direct2700 * update of a branch) to be worth it. So let's cheat and2701 * check with HEAD only which should cover 99% of all usage2702 * scenarios (even 100% of the default ones).2703 */2704unsigned char head_sha1[20];2705int head_flag;2706const char*head_ref;2707 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,2708 head_sha1, &head_flag);2709if(head_ref && (head_flag & REF_ISSYMREF) &&2710!strcmp(head_ref, lock->ref_name)) {2711struct strbuf log_err = STRBUF_INIT;2712if(log_ref_write("HEAD", lock->old_oid.hash, sha1,2713 logmsg,0, &log_err)) {2714error("%s", log_err.buf);2715strbuf_release(&log_err);2716}2717}2718}2719if(commit_ref(lock)) {2720strbuf_addf(err,"Couldn't set%s", lock->ref_name);2721unlock_ref(lock);2722return-1;2723}27242725unlock_ref(lock);2726return0;2727}27282729static intcreate_ref_symlink(struct ref_lock *lock,const char*target)2730{2731int ret = -1;2732#ifndef NO_SYMLINK_HEAD2733char*ref_path =get_locked_file_path(lock->lk);2734unlink(ref_path);2735 ret =symlink(target, ref_path);2736free(ref_path);27372738if(ret)2739fprintf(stderr,"no symlink - falling back to symbolic ref\n");2740#endif2741return ret;2742}27432744static voidupdate_symref_reflog(struct ref_lock *lock,const char*refname,2745const char*target,const char*logmsg)2746{2747struct strbuf err = STRBUF_INIT;2748unsigned char new_sha1[20];2749if(logmsg && !read_ref(target, new_sha1) &&2750log_ref_write(refname, lock->old_oid.hash, new_sha1, logmsg,0, &err)) {2751error("%s", err.buf);2752strbuf_release(&err);2753}2754}27552756static intcreate_symref_locked(struct ref_lock *lock,const char*refname,2757const char*target,const char*logmsg)2758{2759if(prefer_symlink_refs && !create_ref_symlink(lock, target)) {2760update_symref_reflog(lock, refname, target, logmsg);2761return0;2762}27632764if(!fdopen_lock_file(lock->lk,"w"))2765returnerror("unable to fdopen%s:%s",2766 lock->lk->tempfile.filename.buf,strerror(errno));27672768update_symref_reflog(lock, refname, target, logmsg);27692770/* no error check; commit_ref will check ferror */2771fprintf(lock->lk->tempfile.fp,"ref:%s\n", target);2772if(commit_ref(lock) <0)2773returnerror("unable to write symref for%s:%s", refname,2774strerror(errno));2775return0;2776}27772778intcreate_symref(const char*refname,const char*target,const char*logmsg)2779{2780struct strbuf err = STRBUF_INIT;2781struct ref_lock *lock;2782int ret;27832784 lock =lock_ref_sha1_basic(refname, NULL, NULL, NULL, REF_NODEREF, NULL,2785&err);2786if(!lock) {2787error("%s", err.buf);2788strbuf_release(&err);2789return-1;2790}27912792 ret =create_symref_locked(lock, refname, target, logmsg);2793unlock_ref(lock);2794return ret;2795}27962797intset_worktree_head_symref(const char*gitdir,const char*target)2798{2799static struct lock_file head_lock;2800struct ref_lock *lock;2801struct strbuf head_path = STRBUF_INIT;2802const char*head_rel;2803int ret;28042805strbuf_addf(&head_path,"%s/HEAD",absolute_path(gitdir));2806if(hold_lock_file_for_update(&head_lock, head_path.buf,2807 LOCK_NO_DEREF) <0) {2808struct strbuf err = STRBUF_INIT;2809unable_to_lock_message(head_path.buf, errno, &err);2810error("%s", err.buf);2811strbuf_release(&err);2812strbuf_release(&head_path);2813return-1;2814}28152816/* head_rel will be "HEAD" for the main tree, "worktrees/wt/HEAD" for2817 linked trees */2818 head_rel =remove_leading_path(head_path.buf,2819absolute_path(get_git_common_dir()));2820/* to make use of create_symref_locked(), initialize ref_lock */2821 lock =xcalloc(1,sizeof(struct ref_lock));2822 lock->lk = &head_lock;2823 lock->ref_name =xstrdup(head_rel);2824 lock->orig_ref_name =xstrdup(head_rel);28252826 ret =create_symref_locked(lock, head_rel, target, NULL);28272828unlock_ref(lock);/* will free lock */2829strbuf_release(&head_path);2830return ret;2831}28322833intreflog_exists(const char*refname)2834{2835struct stat st;28362837return!lstat(git_path("logs/%s", refname), &st) &&2838S_ISREG(st.st_mode);2839}28402841intdelete_reflog(const char*refname)2842{2843returnremove_path(git_path("logs/%s", refname));2844}28452846static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)2847{2848unsigned char osha1[20], nsha1[20];2849char*email_end, *message;2850unsigned long timestamp;2851int tz;28522853/* old SP new SP name <email> SP time TAB msg LF */2854if(sb->len <83|| sb->buf[sb->len -1] !='\n'||2855get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||2856get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||2857!(email_end =strchr(sb->buf +82,'>')) ||2858 email_end[1] !=' '||2859!(timestamp =strtoul(email_end +2, &message,10)) ||2860!message || message[0] !=' '||2861(message[1] !='+'&& message[1] !='-') ||2862!isdigit(message[2]) || !isdigit(message[3]) ||2863!isdigit(message[4]) || !isdigit(message[5]))2864return0;/* corrupt? */2865 email_end[1] ='\0';2866 tz =strtol(message +1, NULL,10);2867if(message[6] !='\t')2868 message +=6;2869else2870 message +=7;2871returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);2872}28732874static char*find_beginning_of_line(char*bob,char*scan)2875{2876while(bob < scan && *(--scan) !='\n')2877;/* keep scanning backwards */2878/*2879 * Return either beginning of the buffer, or LF at the end of2880 * the previous line.2881 */2882return scan;2883}28842885intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)2886{2887struct strbuf sb = STRBUF_INIT;2888FILE*logfp;2889long pos;2890int ret =0, at_tail =1;28912892 logfp =fopen(git_path("logs/%s", refname),"r");2893if(!logfp)2894return-1;28952896/* Jump to the end */2897if(fseek(logfp,0, SEEK_END) <0)2898returnerror("cannot seek back reflog for%s:%s",2899 refname,strerror(errno));2900 pos =ftell(logfp);2901while(!ret &&0< pos) {2902int cnt;2903size_t nread;2904char buf[BUFSIZ];2905char*endp, *scanp;29062907/* Fill next block from the end */2908 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;2909if(fseek(logfp, pos - cnt, SEEK_SET))2910returnerror("cannot seek back reflog for%s:%s",2911 refname,strerror(errno));2912 nread =fread(buf, cnt,1, logfp);2913if(nread !=1)2914returnerror("cannot read%dbytes from reflog for%s:%s",2915 cnt, refname,strerror(errno));2916 pos -= cnt;29172918 scanp = endp = buf + cnt;2919if(at_tail && scanp[-1] =='\n')2920/* Looking at the final LF at the end of the file */2921 scanp--;2922 at_tail =0;29232924while(buf < scanp) {2925/*2926 * terminating LF of the previous line, or the beginning2927 * of the buffer.2928 */2929char*bp;29302931 bp =find_beginning_of_line(buf, scanp);29322933if(*bp =='\n') {2934/*2935 * The newline is the end of the previous line,2936 * so we know we have complete line starting2937 * at (bp + 1). Prefix it onto any prior data2938 * we collected for the line and process it.2939 */2940strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));2941 scanp = bp;2942 endp = bp +1;2943 ret =show_one_reflog_ent(&sb, fn, cb_data);2944strbuf_reset(&sb);2945if(ret)2946break;2947}else if(!pos) {2948/*2949 * We are at the start of the buffer, and the2950 * start of the file; there is no previous2951 * line, and we have everything for this one.2952 * Process it, and we can end the loop.2953 */2954strbuf_splice(&sb,0,0, buf, endp - buf);2955 ret =show_one_reflog_ent(&sb, fn, cb_data);2956strbuf_reset(&sb);2957break;2958}29592960if(bp == buf) {2961/*2962 * We are at the start of the buffer, and there2963 * is more file to read backwards. Which means2964 * we are in the middle of a line. Note that we2965 * may get here even if *bp was a newline; that2966 * just means we are at the exact end of the2967 * previous line, rather than some spot in the2968 * middle.2969 *2970 * Save away what we have to be combined with2971 * the data from the next read.2972 */2973strbuf_splice(&sb,0,0, buf, endp - buf);2974break;2975}2976}29772978}2979if(!ret && sb.len)2980die("BUG: reverse reflog parser had leftover data");29812982fclose(logfp);2983strbuf_release(&sb);2984return ret;2985}29862987intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)2988{2989FILE*logfp;2990struct strbuf sb = STRBUF_INIT;2991int ret =0;29922993 logfp =fopen(git_path("logs/%s", refname),"r");2994if(!logfp)2995return-1;29962997while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))2998 ret =show_one_reflog_ent(&sb, fn, cb_data);2999fclose(logfp);3000strbuf_release(&sb);3001return ret;3002}3003/*3004 * Call fn for each reflog in the namespace indicated by name. name3005 * must be empty or end with '/'. Name will be used as a scratch3006 * space, but its contents will be restored before return.3007 */3008static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3009{3010DIR*d =opendir(git_path("logs/%s", name->buf));3011int retval =0;3012struct dirent *de;3013int oldlen = name->len;30143015if(!d)3016return name->len ? errno :0;30173018while((de =readdir(d)) != NULL) {3019struct stat st;30203021if(de->d_name[0] =='.')3022continue;3023if(ends_with(de->d_name,".lock"))3024continue;3025strbuf_addstr(name, de->d_name);3026if(stat(git_path("logs/%s", name->buf), &st) <0) {3027;/* silently ignore */3028}else{3029if(S_ISDIR(st.st_mode)) {3030strbuf_addch(name,'/');3031 retval =do_for_each_reflog(name, fn, cb_data);3032}else{3033struct object_id oid;30343035if(read_ref_full(name->buf,0, oid.hash, NULL))3036 retval =error("bad ref for%s", name->buf);3037else3038 retval =fn(name->buf, &oid,0, cb_data);3039}3040if(retval)3041break;3042}3043strbuf_setlen(name, oldlen);3044}3045closedir(d);3046return retval;3047}30483049intfor_each_reflog(each_ref_fn fn,void*cb_data)3050{3051int retval;3052struct strbuf name;3053strbuf_init(&name, PATH_MAX);3054 retval =do_for_each_reflog(&name, fn, cb_data);3055strbuf_release(&name);3056return retval;3057}30583059static intref_update_reject_duplicates(struct string_list *refnames,3060struct strbuf *err)3061{3062int i, n = refnames->nr;30633064assert(err);30653066for(i =1; i < n; i++)3067if(!strcmp(refnames->items[i -1].string, refnames->items[i].string)) {3068strbuf_addf(err,3069"Multiple updates for ref '%s' not allowed.",3070 refnames->items[i].string);3071return1;3072}3073return0;3074}30753076intref_transaction_commit(struct ref_transaction *transaction,3077struct strbuf *err)3078{3079int ret =0, i;3080struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3081struct string_list_item *ref_to_delete;3082struct string_list affected_refnames = STRING_LIST_INIT_NODUP;30833084assert(err);30853086if(transaction->state != REF_TRANSACTION_OPEN)3087die("BUG: commit called for transaction that is not open");30883089if(!transaction->nr) {3090 transaction->state = REF_TRANSACTION_CLOSED;3091return0;3092}30933094/* Fail if a refname appears more than once in the transaction: */3095for(i =0; i < transaction->nr; i++)3096string_list_append(&affected_refnames,3097 transaction->updates[i]->refname);3098string_list_sort(&affected_refnames);3099if(ref_update_reject_duplicates(&affected_refnames, err)) {3100 ret = TRANSACTION_GENERIC_ERROR;3101goto cleanup;3102}31033104/*3105 * Acquire all locks, verify old values if provided, check3106 * that new values are valid, and write new values to the3107 * lockfiles, ready to be activated. Only keep one lockfile3108 * open at a time to avoid running out of file descriptors.3109 */3110for(i =0; i < transaction->nr; i++) {3111struct ref_update *update = transaction->updates[i];31123113if((update->flags & REF_HAVE_NEW) &&3114is_null_sha1(update->new_sha1))3115 update->flags |= REF_DELETING;3116 update->lock =lock_ref_sha1_basic(3117 update->refname,3118((update->flags & REF_HAVE_OLD) ?3119 update->old_sha1 : NULL),3120&affected_refnames, NULL,3121 update->flags,3122&update->type,3123 err);3124if(!update->lock) {3125char*reason;31263127 ret = (errno == ENOTDIR)3128? TRANSACTION_NAME_CONFLICT3129: TRANSACTION_GENERIC_ERROR;3130 reason =strbuf_detach(err, NULL);3131strbuf_addf(err,"cannot lock ref '%s':%s",3132 update->refname, reason);3133free(reason);3134goto cleanup;3135}3136if((update->flags & REF_HAVE_NEW) &&3137!(update->flags & REF_DELETING)) {3138int overwriting_symref = ((update->type & REF_ISSYMREF) &&3139(update->flags & REF_NODEREF));31403141if(!overwriting_symref &&3142!hashcmp(update->lock->old_oid.hash, update->new_sha1)) {3143/*3144 * The reference already has the desired3145 * value, so we don't need to write it.3146 */3147}else if(write_ref_to_lockfile(update->lock,3148 update->new_sha1,3149 err)) {3150char*write_err =strbuf_detach(err, NULL);31513152/*3153 * The lock was freed upon failure of3154 * write_ref_to_lockfile():3155 */3156 update->lock = NULL;3157strbuf_addf(err,3158"cannot update the ref '%s':%s",3159 update->refname, write_err);3160free(write_err);3161 ret = TRANSACTION_GENERIC_ERROR;3162goto cleanup;3163}else{3164 update->flags |= REF_NEEDS_COMMIT;3165}3166}3167if(!(update->flags & REF_NEEDS_COMMIT)) {3168/*3169 * We didn't have to write anything to the lockfile.3170 * Close it to free up the file descriptor:3171 */3172if(close_ref(update->lock)) {3173strbuf_addf(err,"Couldn't close%s.lock",3174 update->refname);3175goto cleanup;3176}3177}3178}31793180/* Perform updates first so live commits remain referenced */3181for(i =0; i < transaction->nr; i++) {3182struct ref_update *update = transaction->updates[i];31833184if(update->flags & REF_NEEDS_COMMIT) {3185if(commit_ref_update(update->lock,3186 update->new_sha1, update->msg,3187 update->flags, err)) {3188/* freed by commit_ref_update(): */3189 update->lock = NULL;3190 ret = TRANSACTION_GENERIC_ERROR;3191goto cleanup;3192}else{3193/* freed by commit_ref_update(): */3194 update->lock = NULL;3195}3196}3197}31983199/* Perform deletes now that updates are safely completed */3200for(i =0; i < transaction->nr; i++) {3201struct ref_update *update = transaction->updates[i];32023203if(update->flags & REF_DELETING) {3204if(delete_ref_loose(update->lock, update->type, err)) {3205 ret = TRANSACTION_GENERIC_ERROR;3206goto cleanup;3207}32083209if(!(update->flags & REF_ISPRUNING))3210string_list_append(&refs_to_delete,3211 update->lock->ref_name);3212}3213}32143215if(repack_without_refs(&refs_to_delete, err)) {3216 ret = TRANSACTION_GENERIC_ERROR;3217goto cleanup;3218}3219for_each_string_list_item(ref_to_delete, &refs_to_delete)3220unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3221clear_loose_ref_cache(&ref_cache);32223223cleanup:3224 transaction->state = REF_TRANSACTION_CLOSED;32253226for(i =0; i < transaction->nr; i++)3227if(transaction->updates[i]->lock)3228unlock_ref(transaction->updates[i]->lock);3229string_list_clear(&refs_to_delete,0);3230string_list_clear(&affected_refnames,0);3231return ret;3232}32333234static intref_present(const char*refname,3235const struct object_id *oid,int flags,void*cb_data)3236{3237struct string_list *affected_refnames = cb_data;32383239returnstring_list_has_string(affected_refnames, refname);3240}32413242intinitial_ref_transaction_commit(struct ref_transaction *transaction,3243struct strbuf *err)3244{3245int ret =0, i;3246struct string_list affected_refnames = STRING_LIST_INIT_NODUP;32473248assert(err);32493250if(transaction->state != REF_TRANSACTION_OPEN)3251die("BUG: commit called for transaction that is not open");32523253/* Fail if a refname appears more than once in the transaction: */3254for(i =0; i < transaction->nr; i++)3255string_list_append(&affected_refnames,3256 transaction->updates[i]->refname);3257string_list_sort(&affected_refnames);3258if(ref_update_reject_duplicates(&affected_refnames, err)) {3259 ret = TRANSACTION_GENERIC_ERROR;3260goto cleanup;3261}32623263/*3264 * It's really undefined to call this function in an active3265 * repository or when there are existing references: we are3266 * only locking and changing packed-refs, so (1) any3267 * simultaneous processes might try to change a reference at3268 * the same time we do, and (2) any existing loose versions of3269 * the references that we are setting would have precedence3270 * over our values. But some remote helpers create the remote3271 * "HEAD" and "master" branches before calling this function,3272 * so here we really only check that none of the references3273 * that we are creating already exists.3274 */3275if(for_each_rawref(ref_present, &affected_refnames))3276die("BUG: initial ref transaction called with existing refs");32773278for(i =0; i < transaction->nr; i++) {3279struct ref_update *update = transaction->updates[i];32803281if((update->flags & REF_HAVE_OLD) &&3282!is_null_sha1(update->old_sha1))3283die("BUG: initial ref transaction with old_sha1 set");3284if(verify_refname_available(update->refname,3285&affected_refnames, NULL,3286 err)) {3287 ret = TRANSACTION_NAME_CONFLICT;3288goto cleanup;3289}3290}32913292if(lock_packed_refs(0)) {3293strbuf_addf(err,"unable to lock packed-refs file:%s",3294strerror(errno));3295 ret = TRANSACTION_GENERIC_ERROR;3296goto cleanup;3297}32983299for(i =0; i < transaction->nr; i++) {3300struct ref_update *update = transaction->updates[i];33013302if((update->flags & REF_HAVE_NEW) &&3303!is_null_sha1(update->new_sha1))3304add_packed_ref(update->refname, update->new_sha1);3305}33063307if(commit_packed_refs()) {3308strbuf_addf(err,"unable to commit packed-refs file:%s",3309strerror(errno));3310 ret = TRANSACTION_GENERIC_ERROR;3311goto cleanup;3312}33133314cleanup:3315 transaction->state = REF_TRANSACTION_CLOSED;3316string_list_clear(&affected_refnames,0);3317return ret;3318}33193320struct expire_reflog_cb {3321unsigned int flags;3322 reflog_expiry_should_prune_fn *should_prune_fn;3323void*policy_cb;3324FILE*newlog;3325unsigned char last_kept_sha1[20];3326};33273328static intexpire_reflog_ent(unsigned char*osha1,unsigned char*nsha1,3329const char*email,unsigned long timestamp,int tz,3330const char*message,void*cb_data)3331{3332struct expire_reflog_cb *cb = cb_data;3333struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;33343335if(cb->flags & EXPIRE_REFLOGS_REWRITE)3336 osha1 = cb->last_kept_sha1;33373338if((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,3339 message, policy_cb)) {3340if(!cb->newlog)3341printf("would prune%s", message);3342else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3343printf("prune%s", message);3344}else{3345if(cb->newlog) {3346fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",3347sha1_to_hex(osha1),sha1_to_hex(nsha1),3348 email, timestamp, tz, message);3349hashcpy(cb->last_kept_sha1, nsha1);3350}3351if(cb->flags & EXPIRE_REFLOGS_VERBOSE)3352printf("keep%s", message);3353}3354return0;3355}33563357intreflog_expire(const char*refname,const unsigned char*sha1,3358unsigned int flags,3359 reflog_expiry_prepare_fn prepare_fn,3360 reflog_expiry_should_prune_fn should_prune_fn,3361 reflog_expiry_cleanup_fn cleanup_fn,3362void*policy_cb_data)3363{3364static struct lock_file reflog_lock;3365struct expire_reflog_cb cb;3366struct ref_lock *lock;3367char*log_file;3368int status =0;3369int type;3370struct strbuf err = STRBUF_INIT;33713372memset(&cb,0,sizeof(cb));3373 cb.flags = flags;3374 cb.policy_cb = policy_cb_data;3375 cb.should_prune_fn = should_prune_fn;33763377/*3378 * The reflog file is locked by holding the lock on the3379 * reference itself, plus we might need to update the3380 * reference if --updateref was specified:3381 */3382 lock =lock_ref_sha1_basic(refname, sha1, NULL, NULL, REF_NODEREF,3383&type, &err);3384if(!lock) {3385error("cannot lock ref '%s':%s", refname, err.buf);3386strbuf_release(&err);3387return-1;3388}3389if(!reflog_exists(refname)) {3390unlock_ref(lock);3391return0;3392}33933394 log_file =git_pathdup("logs/%s", refname);3395if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3396/*3397 * Even though holding $GIT_DIR/logs/$reflog.lock has3398 * no locking implications, we use the lock_file3399 * machinery here anyway because it does a lot of the3400 * work we need, including cleaning up if the program3401 * exits unexpectedly.3402 */3403if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {3404struct strbuf err = STRBUF_INIT;3405unable_to_lock_message(log_file, errno, &err);3406error("%s", err.buf);3407strbuf_release(&err);3408goto failure;3409}3410 cb.newlog =fdopen_lock_file(&reflog_lock,"w");3411if(!cb.newlog) {3412error("cannot fdopen%s(%s)",3413get_lock_file_path(&reflog_lock),strerror(errno));3414goto failure;3415}3416}34173418(*prepare_fn)(refname, sha1, cb.policy_cb);3419for_each_reflog_ent(refname, expire_reflog_ent, &cb);3420(*cleanup_fn)(cb.policy_cb);34213422if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {3423/*3424 * It doesn't make sense to adjust a reference pointed3425 * to by a symbolic ref based on expiring entries in3426 * the symbolic reference's reflog. Nor can we update3427 * a reference if there are no remaining reflog3428 * entries.3429 */3430int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&3431!(type & REF_ISSYMREF) &&3432!is_null_sha1(cb.last_kept_sha1);34333434if(close_lock_file(&reflog_lock)) {3435 status |=error("couldn't write%s:%s", log_file,3436strerror(errno));3437}else if(update &&3438(write_in_full(get_lock_file_fd(lock->lk),3439sha1_to_hex(cb.last_kept_sha1),40) !=40||3440write_str_in_full(get_lock_file_fd(lock->lk),"\n") !=1||3441close_ref(lock) <0)) {3442 status |=error("couldn't write%s",3443get_lock_file_path(lock->lk));3444rollback_lock_file(&reflog_lock);3445}else if(commit_lock_file(&reflog_lock)) {3446 status |=error("unable to write reflog '%s' (%s)",3447 log_file,strerror(errno));3448}else if(update &&commit_ref(lock)) {3449 status |=error("couldn't set%s", lock->ref_name);3450}3451}3452free(log_file);3453unlock_ref(lock);3454return status;34553456 failure:3457rollback_lock_file(&reflog_lock);3458free(log_file);3459unlock_ref(lock);3460return-1;3461}