1#include"cache.h" 2#include"refs.h" 3#include"object.h" 4#include"tag.h" 5#include"dir.h" 6#include"string-list.h" 7 8/* 9 * Make sure "ref" is something reasonable to have under ".git/refs/"; 10 * We do not like it if: 11 * 12 * - any path component of it begins with ".", or 13 * - it has double dots "..", or 14 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 15 * - it ends with a "/". 16 * - it ends with ".lock" 17 * - it contains a "\" (backslash) 18 */ 19 20/* Return true iff ch is not allowed in reference names. */ 21staticinlineintbad_ref_char(int ch) 22{ 23if(((unsigned) ch) <=' '|| ch ==0x7f|| 24 ch =='~'|| ch =='^'|| ch ==':'|| ch =='\\') 25return1; 26/* 2.13 Pattern Matching Notation */ 27if(ch =='*'|| ch =='?'|| ch =='[')/* Unsupported */ 28return1; 29return0; 30} 31 32/* 33 * Try to read one refname component from the front of refname. Return 34 * the length of the component found, or -1 if the component is not 35 * legal. 36 */ 37static intcheck_refname_component(const char*refname,int flags) 38{ 39const char*cp; 40char last ='\0'; 41 42for(cp = refname; ; cp++) { 43char ch = *cp; 44if(ch =='\0'|| ch =='/') 45break; 46if(bad_ref_char(ch)) 47return-1;/* Illegal character in refname. */ 48if(last =='.'&& ch =='.') 49return-1;/* Refname contains "..". */ 50if(last =='@'&& ch =='{') 51return-1;/* Refname contains "@{". */ 52 last = ch; 53} 54if(cp == refname) 55return0;/* Component has zero length. */ 56if(refname[0] =='.') { 57if(!(flags & REFNAME_DOT_COMPONENT)) 58return-1;/* Component starts with '.'. */ 59/* 60 * Even if leading dots are allowed, don't allow "." 61 * as a component (".." is prevented by a rule above). 62 */ 63if(refname[1] =='\0') 64return-1;/* Component equals ".". */ 65} 66if(cp - refname >=5&& !memcmp(cp -5,".lock",5)) 67return-1;/* Refname ends with ".lock". */ 68return cp - refname; 69} 70 71intcheck_refname_format(const char*refname,int flags) 72{ 73int component_len, component_count =0; 74 75if(!strcmp(refname,"@")) 76/* Refname is a single character '@'. */ 77return-1; 78 79while(1) { 80/* We are at the start of a path component. */ 81 component_len =check_refname_component(refname, flags); 82if(component_len <=0) { 83if((flags & REFNAME_REFSPEC_PATTERN) && 84 refname[0] =='*'&& 85(refname[1] =='\0'|| refname[1] =='/')) { 86/* Accept one wildcard as a full refname component. */ 87 flags &= ~REFNAME_REFSPEC_PATTERN; 88 component_len =1; 89}else{ 90return-1; 91} 92} 93 component_count++; 94if(refname[component_len] =='\0') 95break; 96/* Skip to next component. */ 97 refname += component_len +1; 98} 99 100if(refname[component_len -1] =='.') 101return-1;/* Refname ends with '.'. */ 102if(!(flags & REFNAME_ALLOW_ONELEVEL) && component_count <2) 103return-1;/* Refname has only one component. */ 104return0; 105} 106 107struct ref_entry; 108 109/* 110 * Information used (along with the information in ref_entry) to 111 * describe a single cached reference. This data structure only 112 * occurs embedded in a union in struct ref_entry, and only when 113 * (ref_entry->flag & REF_DIR) is zero. 114 */ 115struct ref_value { 116/* 117 * The name of the object to which this reference resolves 118 * (which may be a tag object). If REF_ISBROKEN, this is 119 * null. If REF_ISSYMREF, then this is the name of the object 120 * referred to by the last reference in the symlink chain. 121 */ 122unsigned char sha1[20]; 123 124/* 125 * If REF_KNOWS_PEELED, then this field holds the peeled value 126 * of this reference, or null if the reference is known not to 127 * be peelable. See the documentation for peel_ref() for an 128 * exact definition of "peelable". 129 */ 130unsigned char peeled[20]; 131}; 132 133struct ref_cache; 134 135/* 136 * Information used (along with the information in ref_entry) to 137 * describe a level in the hierarchy of references. This data 138 * structure only occurs embedded in a union in struct ref_entry, and 139 * only when (ref_entry.flag & REF_DIR) is set. In that case, 140 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 141 * in the directory have already been read: 142 * 143 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 144 * or packed references, already read. 145 * 146 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 147 * references that hasn't been read yet (nor has any of its 148 * subdirectories). 149 * 150 * Entries within a directory are stored within a growable array of 151 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 152 * sorted are sorted by their component name in strcmp() order and the 153 * remaining entries are unsorted. 154 * 155 * Loose references are read lazily, one directory at a time. When a 156 * directory of loose references is read, then all of the references 157 * in that directory are stored, and REF_INCOMPLETE stubs are created 158 * for any subdirectories, but the subdirectories themselves are not 159 * read. The reading is triggered by get_ref_dir(). 160 */ 161struct ref_dir { 162int nr, alloc; 163 164/* 165 * Entries with index 0 <= i < sorted are sorted by name. New 166 * entries are appended to the list unsorted, and are sorted 167 * only when required; thus we avoid the need to sort the list 168 * after the addition of every reference. 169 */ 170int sorted; 171 172/* A pointer to the ref_cache that contains this ref_dir. */ 173struct ref_cache *ref_cache; 174 175struct ref_entry **entries; 176}; 177 178/* 179 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 180 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see 181 * refs.h. 182 */ 183 184/* 185 * The field ref_entry->u.value.peeled of this value entry contains 186 * the correct peeled value for the reference, which might be 187 * null_sha1 if the reference is not a tag or if it is broken. 188 */ 189#define REF_KNOWS_PEELED 0x08 190 191/* ref_entry represents a directory of references */ 192#define REF_DIR 0x10 193 194/* 195 * Entry has not yet been read from disk (used only for REF_DIR 196 * entries representing loose references) 197 */ 198#define REF_INCOMPLETE 0x20 199 200/* 201 * A ref_entry represents either a reference or a "subdirectory" of 202 * references. 203 * 204 * Each directory in the reference namespace is represented by a 205 * ref_entry with (flags & REF_DIR) set and containing a subdir member 206 * that holds the entries in that directory that have been read so 207 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 208 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 209 * used for loose reference directories. 210 * 211 * References are represented by a ref_entry with (flags & REF_DIR) 212 * unset and a value member that describes the reference's value. The 213 * flag member is at the ref_entry level, but it is also needed to 214 * interpret the contents of the value field (in other words, a 215 * ref_value object is not very much use without the enclosing 216 * ref_entry). 217 * 218 * Reference names cannot end with slash and directories' names are 219 * always stored with a trailing slash (except for the top-level 220 * directory, which is always denoted by ""). This has two nice 221 * consequences: (1) when the entries in each subdir are sorted 222 * lexicographically by name (as they usually are), the references in 223 * a whole tree can be generated in lexicographic order by traversing 224 * the tree in left-to-right, depth-first order; (2) the names of 225 * references and subdirectories cannot conflict, and therefore the 226 * presence of an empty subdirectory does not block the creation of a 227 * similarly-named reference. (The fact that reference names with the 228 * same leading components can conflict *with each other* is a 229 * separate issue that is regulated by is_refname_available().) 230 * 231 * Please note that the name field contains the fully-qualified 232 * reference (or subdirectory) name. Space could be saved by only 233 * storing the relative names. But that would require the full names 234 * to be generated on the fly when iterating in do_for_each_ref(), and 235 * would break callback functions, who have always been able to assume 236 * that the name strings that they are passed will not be freed during 237 * the iteration. 238 */ 239struct ref_entry { 240unsigned char flag;/* ISSYMREF? ISPACKED? */ 241union{ 242struct ref_value value;/* if not (flags&REF_DIR) */ 243struct ref_dir subdir;/* if (flags&REF_DIR) */ 244} u; 245/* 246 * The full name of the reference (e.g., "refs/heads/master") 247 * or the full name of the directory with a trailing slash 248 * (e.g., "refs/heads/"): 249 */ 250char name[FLEX_ARRAY]; 251}; 252 253static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 254 255static struct ref_dir *get_ref_dir(struct ref_entry *entry) 256{ 257struct ref_dir *dir; 258assert(entry->flag & REF_DIR); 259 dir = &entry->u.subdir; 260if(entry->flag & REF_INCOMPLETE) { 261read_loose_refs(entry->name, dir); 262 entry->flag &= ~REF_INCOMPLETE; 263} 264return dir; 265} 266 267static struct ref_entry *create_ref_entry(const char*refname, 268const unsigned char*sha1,int flag, 269int check_name) 270{ 271int len; 272struct ref_entry *ref; 273 274if(check_name && 275check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) 276die("Reference has invalid format: '%s'", refname); 277 len =strlen(refname) +1; 278 ref =xmalloc(sizeof(struct ref_entry) + len); 279hashcpy(ref->u.value.sha1, sha1); 280hashclr(ref->u.value.peeled); 281memcpy(ref->name, refname, len); 282 ref->flag = flag; 283return ref; 284} 285 286static voidclear_ref_dir(struct ref_dir *dir); 287 288static voidfree_ref_entry(struct ref_entry *entry) 289{ 290if(entry->flag & REF_DIR) { 291/* 292 * Do not use get_ref_dir() here, as that might 293 * trigger the reading of loose refs. 294 */ 295clear_ref_dir(&entry->u.subdir); 296} 297free(entry); 298} 299 300/* 301 * Add a ref_entry to the end of dir (unsorted). Entry is always 302 * stored directly in dir; no recursion into subdirectories is 303 * done. 304 */ 305static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 306{ 307ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 308 dir->entries[dir->nr++] = entry; 309/* optimize for the case that entries are added in order */ 310if(dir->nr ==1|| 311(dir->nr == dir->sorted +1&& 312strcmp(dir->entries[dir->nr -2]->name, 313 dir->entries[dir->nr -1]->name) <0)) 314 dir->sorted = dir->nr; 315} 316 317/* 318 * Clear and free all entries in dir, recursively. 319 */ 320static voidclear_ref_dir(struct ref_dir *dir) 321{ 322int i; 323for(i =0; i < dir->nr; i++) 324free_ref_entry(dir->entries[i]); 325free(dir->entries); 326 dir->sorted = dir->nr = dir->alloc =0; 327 dir->entries = NULL; 328} 329 330/* 331 * Create a struct ref_entry object for the specified dirname. 332 * dirname is the name of the directory with a trailing slash (e.g., 333 * "refs/heads/") or "" for the top-level directory. 334 */ 335static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 336const char*dirname,size_t len, 337int incomplete) 338{ 339struct ref_entry *direntry; 340 direntry =xcalloc(1,sizeof(struct ref_entry) + len +1); 341memcpy(direntry->name, dirname, len); 342 direntry->name[len] ='\0'; 343 direntry->u.subdir.ref_cache = ref_cache; 344 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 345return direntry; 346} 347 348static intref_entry_cmp(const void*a,const void*b) 349{ 350struct ref_entry *one = *(struct ref_entry **)a; 351struct ref_entry *two = *(struct ref_entry **)b; 352returnstrcmp(one->name, two->name); 353} 354 355static voidsort_ref_dir(struct ref_dir *dir); 356 357struct string_slice { 358size_t len; 359const char*str; 360}; 361 362static intref_entry_cmp_sslice(const void*key_,const void*ent_) 363{ 364const struct string_slice *key = key_; 365const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 366int cmp =strncmp(key->str, ent->name, key->len); 367if(cmp) 368return cmp; 369return'\0'- (unsigned char)ent->name[key->len]; 370} 371 372/* 373 * Return the index of the entry with the given refname from the 374 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 375 * no such entry is found. dir must already be complete. 376 */ 377static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 378{ 379struct ref_entry **r; 380struct string_slice key; 381 382if(refname == NULL || !dir->nr) 383return-1; 384 385sort_ref_dir(dir); 386 key.len = len; 387 key.str = refname; 388 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 389 ref_entry_cmp_sslice); 390 391if(r == NULL) 392return-1; 393 394return r - dir->entries; 395} 396 397/* 398 * Search for a directory entry directly within dir (without 399 * recursing). Sort dir if necessary. subdirname must be a directory 400 * name (i.e., end in '/'). If mkdir is set, then create the 401 * directory if it is missing; otherwise, return NULL if the desired 402 * directory cannot be found. dir must already be complete. 403 */ 404static struct ref_dir *search_for_subdir(struct ref_dir *dir, 405const char*subdirname,size_t len, 406int mkdir) 407{ 408int entry_index =search_ref_dir(dir, subdirname, len); 409struct ref_entry *entry; 410if(entry_index == -1) { 411if(!mkdir) 412return NULL; 413/* 414 * Since dir is complete, the absence of a subdir 415 * means that the subdir really doesn't exist; 416 * therefore, create an empty record for it but mark 417 * the record complete. 418 */ 419 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 420add_entry_to_dir(dir, entry); 421}else{ 422 entry = dir->entries[entry_index]; 423} 424returnget_ref_dir(entry); 425} 426 427/* 428 * If refname is a reference name, find the ref_dir within the dir 429 * tree that should hold refname. If refname is a directory name 430 * (i.e., ends in '/'), then return that ref_dir itself. dir must 431 * represent the top-level directory and must already be complete. 432 * Sort ref_dirs and recurse into subdirectories as necessary. If 433 * mkdir is set, then create any missing directories; otherwise, 434 * return NULL if the desired directory cannot be found. 435 */ 436static struct ref_dir *find_containing_dir(struct ref_dir *dir, 437const char*refname,int mkdir) 438{ 439const char*slash; 440for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 441size_t dirnamelen = slash - refname +1; 442struct ref_dir *subdir; 443 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 444if(!subdir) { 445 dir = NULL; 446break; 447} 448 dir = subdir; 449} 450 451return dir; 452} 453 454/* 455 * Find the value entry with the given name in dir, sorting ref_dirs 456 * and recursing into subdirectories as necessary. If the name is not 457 * found or it corresponds to a directory entry, return NULL. 458 */ 459static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 460{ 461int entry_index; 462struct ref_entry *entry; 463 dir =find_containing_dir(dir, refname,0); 464if(!dir) 465return NULL; 466 entry_index =search_ref_dir(dir, refname,strlen(refname)); 467if(entry_index == -1) 468return NULL; 469 entry = dir->entries[entry_index]; 470return(entry->flag & REF_DIR) ? NULL : entry; 471} 472 473/* 474 * Remove the entry with the given name from dir, recursing into 475 * subdirectories as necessary. If refname is the name of a directory 476 * (i.e., ends with '/'), then remove the directory and its contents. 477 * If the removal was successful, return the number of entries 478 * remaining in the directory entry that contained the deleted entry. 479 * If the name was not found, return -1. Please note that this 480 * function only deletes the entry from the cache; it does not delete 481 * it from the filesystem or ensure that other cache entries (which 482 * might be symbolic references to the removed entry) are updated. 483 * Nor does it remove any containing dir entries that might be made 484 * empty by the removal. dir must represent the top-level directory 485 * and must already be complete. 486 */ 487static intremove_entry(struct ref_dir *dir,const char*refname) 488{ 489int refname_len =strlen(refname); 490int entry_index; 491struct ref_entry *entry; 492int is_dir = refname[refname_len -1] =='/'; 493if(is_dir) { 494/* 495 * refname represents a reference directory. Remove 496 * the trailing slash; otherwise we will get the 497 * directory *representing* refname rather than the 498 * one *containing* it. 499 */ 500char*dirname =xmemdupz(refname, refname_len -1); 501 dir =find_containing_dir(dir, dirname,0); 502free(dirname); 503}else{ 504 dir =find_containing_dir(dir, refname,0); 505} 506if(!dir) 507return-1; 508 entry_index =search_ref_dir(dir, refname, refname_len); 509if(entry_index == -1) 510return-1; 511 entry = dir->entries[entry_index]; 512 513memmove(&dir->entries[entry_index], 514&dir->entries[entry_index +1], 515(dir->nr - entry_index -1) *sizeof(*dir->entries) 516); 517 dir->nr--; 518if(dir->sorted > entry_index) 519 dir->sorted--; 520free_ref_entry(entry); 521return dir->nr; 522} 523 524/* 525 * Add a ref_entry to the ref_dir (unsorted), recursing into 526 * subdirectories as necessary. dir must represent the top-level 527 * directory. Return 0 on success. 528 */ 529static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 530{ 531 dir =find_containing_dir(dir, ref->name,1); 532if(!dir) 533return-1; 534add_entry_to_dir(dir, ref); 535return0; 536} 537 538/* 539 * Emit a warning and return true iff ref1 and ref2 have the same name 540 * and the same sha1. Die if they have the same name but different 541 * sha1s. 542 */ 543static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 544{ 545if(strcmp(ref1->name, ref2->name)) 546return0; 547 548/* Duplicate name; make sure that they don't conflict: */ 549 550if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 551/* This is impossible by construction */ 552die("Reference directory conflict:%s", ref1->name); 553 554if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 555die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 556 557warning("Duplicated ref:%s", ref1->name); 558return1; 559} 560 561/* 562 * Sort the entries in dir non-recursively (if they are not already 563 * sorted) and remove any duplicate entries. 564 */ 565static voidsort_ref_dir(struct ref_dir *dir) 566{ 567int i, j; 568struct ref_entry *last = NULL; 569 570/* 571 * This check also prevents passing a zero-length array to qsort(), 572 * which is a problem on some platforms. 573 */ 574if(dir->sorted == dir->nr) 575return; 576 577qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 578 579/* Remove any duplicates: */ 580for(i =0, j =0; j < dir->nr; j++) { 581struct ref_entry *entry = dir->entries[j]; 582if(last &&is_dup_ref(last, entry)) 583free_ref_entry(entry); 584else 585 last = dir->entries[i++] = entry; 586} 587 dir->sorted = dir->nr = i; 588} 589 590/* Include broken references in a do_for_each_ref*() iteration: */ 591#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 592 593/* 594 * Return true iff the reference described by entry can be resolved to 595 * an object in the database. Emit a warning if the referred-to 596 * object does not exist. 597 */ 598static intref_resolves_to_object(struct ref_entry *entry) 599{ 600if(entry->flag & REF_ISBROKEN) 601return0; 602if(!has_sha1_file(entry->u.value.sha1)) { 603error("%sdoes not point to a valid object!", entry->name); 604return0; 605} 606return1; 607} 608 609/* 610 * current_ref is a performance hack: when iterating over references 611 * using the for_each_ref*() functions, current_ref is set to the 612 * current reference's entry before calling the callback function. If 613 * the callback function calls peel_ref(), then peel_ref() first 614 * checks whether the reference to be peeled is the current reference 615 * (it usually is) and if so, returns that reference's peeled version 616 * if it is available. This avoids a refname lookup in a common case. 617 */ 618static struct ref_entry *current_ref; 619 620typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 621 622struct ref_entry_cb { 623const char*base; 624int trim; 625int flags; 626 each_ref_fn *fn; 627void*cb_data; 628}; 629 630/* 631 * Handle one reference in a do_for_each_ref*()-style iteration, 632 * calling an each_ref_fn for each entry. 633 */ 634static intdo_one_ref(struct ref_entry *entry,void*cb_data) 635{ 636struct ref_entry_cb *data = cb_data; 637struct ref_entry *old_current_ref; 638int retval; 639 640if(!starts_with(entry->name, data->base)) 641return0; 642 643if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 644!ref_resolves_to_object(entry)) 645return0; 646 647/* Store the old value, in case this is a recursive call: */ 648 old_current_ref = current_ref; 649 current_ref = entry; 650 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 651 entry->flag, data->cb_data); 652 current_ref = old_current_ref; 653return retval; 654} 655 656/* 657 * Call fn for each reference in dir that has index in the range 658 * offset <= index < dir->nr. Recurse into subdirectories that are in 659 * that index range, sorting them before iterating. This function 660 * does not sort dir itself; it should be sorted beforehand. fn is 661 * called for all references, including broken ones. 662 */ 663static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 664 each_ref_entry_fn fn,void*cb_data) 665{ 666int i; 667assert(dir->sorted == dir->nr); 668for(i = offset; i < dir->nr; i++) { 669struct ref_entry *entry = dir->entries[i]; 670int retval; 671if(entry->flag & REF_DIR) { 672struct ref_dir *subdir =get_ref_dir(entry); 673sort_ref_dir(subdir); 674 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 675}else{ 676 retval =fn(entry, cb_data); 677} 678if(retval) 679return retval; 680} 681return0; 682} 683 684/* 685 * Call fn for each reference in the union of dir1 and dir2, in order 686 * by refname. Recurse into subdirectories. If a value entry appears 687 * in both dir1 and dir2, then only process the version that is in 688 * dir2. The input dirs must already be sorted, but subdirs will be 689 * sorted as needed. fn is called for all references, including 690 * broken ones. 691 */ 692static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 693struct ref_dir *dir2, 694 each_ref_entry_fn fn,void*cb_data) 695{ 696int retval; 697int i1 =0, i2 =0; 698 699assert(dir1->sorted == dir1->nr); 700assert(dir2->sorted == dir2->nr); 701while(1) { 702struct ref_entry *e1, *e2; 703int cmp; 704if(i1 == dir1->nr) { 705returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 706} 707if(i2 == dir2->nr) { 708returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 709} 710 e1 = dir1->entries[i1]; 711 e2 = dir2->entries[i2]; 712 cmp =strcmp(e1->name, e2->name); 713if(cmp ==0) { 714if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 715/* Both are directories; descend them in parallel. */ 716struct ref_dir *subdir1 =get_ref_dir(e1); 717struct ref_dir *subdir2 =get_ref_dir(e2); 718sort_ref_dir(subdir1); 719sort_ref_dir(subdir2); 720 retval =do_for_each_entry_in_dirs( 721 subdir1, subdir2, fn, cb_data); 722 i1++; 723 i2++; 724}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 725/* Both are references; ignore the one from dir1. */ 726 retval =fn(e2, cb_data); 727 i1++; 728 i2++; 729}else{ 730die("conflict between reference and directory:%s", 731 e1->name); 732} 733}else{ 734struct ref_entry *e; 735if(cmp <0) { 736 e = e1; 737 i1++; 738}else{ 739 e = e2; 740 i2++; 741} 742if(e->flag & REF_DIR) { 743struct ref_dir *subdir =get_ref_dir(e); 744sort_ref_dir(subdir); 745 retval =do_for_each_entry_in_dir( 746 subdir,0, fn, cb_data); 747}else{ 748 retval =fn(e, cb_data); 749} 750} 751if(retval) 752return retval; 753} 754} 755 756/* 757 * Load all of the refs from the dir into our in-memory cache. The hard work 758 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 759 * through all of the sub-directories. We do not even need to care about 760 * sorting, as traversal order does not matter to us. 761 */ 762static voidprime_ref_dir(struct ref_dir *dir) 763{ 764int i; 765for(i =0; i < dir->nr; i++) { 766struct ref_entry *entry = dir->entries[i]; 767if(entry->flag & REF_DIR) 768prime_ref_dir(get_ref_dir(entry)); 769} 770} 771/* 772 * Return true iff refname1 and refname2 conflict with each other. 773 * Two reference names conflict if one of them exactly matches the 774 * leading components of the other; e.g., "foo/bar" conflicts with 775 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 776 * "foo/barbados". 777 */ 778static intnames_conflict(const char*refname1,const char*refname2) 779{ 780for(; *refname1 && *refname1 == *refname2; refname1++, refname2++) 781; 782return(*refname1 =='\0'&& *refname2 =='/') 783|| (*refname1 =='/'&& *refname2 =='\0'); 784} 785 786struct name_conflict_cb { 787const char*refname; 788const char*oldrefname; 789const char*conflicting_refname; 790}; 791 792static intname_conflict_fn(struct ref_entry *entry,void*cb_data) 793{ 794struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data; 795if(data->oldrefname && !strcmp(data->oldrefname, entry->name)) 796return0; 797if(names_conflict(data->refname, entry->name)) { 798 data->conflicting_refname = entry->name; 799return1; 800} 801return0; 802} 803 804/* 805 * Return true iff a reference named refname could be created without 806 * conflicting with the name of an existing reference in dir. If 807 * oldrefname is non-NULL, ignore potential conflicts with oldrefname 808 * (e.g., because oldrefname is scheduled for deletion in the same 809 * operation). 810 */ 811static intis_refname_available(const char*refname,const char*oldrefname, 812struct ref_dir *dir) 813{ 814struct name_conflict_cb data; 815 data.refname = refname; 816 data.oldrefname = oldrefname; 817 data.conflicting_refname = NULL; 818 819sort_ref_dir(dir); 820if(do_for_each_entry_in_dir(dir,0, name_conflict_fn, &data)) { 821error("'%s' exists; cannot create '%s'", 822 data.conflicting_refname, refname); 823return0; 824} 825return1; 826} 827 828struct packed_ref_cache { 829struct ref_entry *root; 830 831/* 832 * Count of references to the data structure in this instance, 833 * including the pointer from ref_cache::packed if any. The 834 * data will not be freed as long as the reference count is 835 * nonzero. 836 */ 837unsigned int referrers; 838 839/* 840 * Iff the packed-refs file associated with this instance is 841 * currently locked for writing, this points at the associated 842 * lock (which is owned by somebody else). The referrer count 843 * is also incremented when the file is locked and decremented 844 * when it is unlocked. 845 */ 846struct lock_file *lock; 847 848/* The metadata from when this packed-refs cache was read */ 849struct stat_validity validity; 850}; 851 852/* 853 * Future: need to be in "struct repository" 854 * when doing a full libification. 855 */ 856static struct ref_cache { 857struct ref_cache *next; 858struct ref_entry *loose; 859struct packed_ref_cache *packed; 860/* 861 * The submodule name, or "" for the main repo. We allocate 862 * length 1 rather than FLEX_ARRAY so that the main ref_cache 863 * is initialized correctly. 864 */ 865char name[1]; 866} ref_cache, *submodule_ref_caches; 867 868/* Lock used for the main packed-refs file: */ 869static struct lock_file packlock; 870 871/* 872 * Increment the reference count of *packed_refs. 873 */ 874static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 875{ 876 packed_refs->referrers++; 877} 878 879/* 880 * Decrease the reference count of *packed_refs. If it goes to zero, 881 * free *packed_refs and return true; otherwise return false. 882 */ 883static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 884{ 885if(!--packed_refs->referrers) { 886free_ref_entry(packed_refs->root); 887stat_validity_clear(&packed_refs->validity); 888free(packed_refs); 889return1; 890}else{ 891return0; 892} 893} 894 895static voidclear_packed_ref_cache(struct ref_cache *refs) 896{ 897if(refs->packed) { 898struct packed_ref_cache *packed_refs = refs->packed; 899 900if(packed_refs->lock) 901die("internal error: packed-ref cache cleared while locked"); 902 refs->packed = NULL; 903release_packed_ref_cache(packed_refs); 904} 905} 906 907static voidclear_loose_ref_cache(struct ref_cache *refs) 908{ 909if(refs->loose) { 910free_ref_entry(refs->loose); 911 refs->loose = NULL; 912} 913} 914 915static struct ref_cache *create_ref_cache(const char*submodule) 916{ 917int len; 918struct ref_cache *refs; 919if(!submodule) 920 submodule =""; 921 len =strlen(submodule) +1; 922 refs =xcalloc(1,sizeof(struct ref_cache) + len); 923memcpy(refs->name, submodule, len); 924return refs; 925} 926 927/* 928 * Return a pointer to a ref_cache for the specified submodule. For 929 * the main repository, use submodule==NULL. The returned structure 930 * will be allocated and initialized but not necessarily populated; it 931 * should not be freed. 932 */ 933static struct ref_cache *get_ref_cache(const char*submodule) 934{ 935struct ref_cache *refs; 936 937if(!submodule || !*submodule) 938return&ref_cache; 939 940for(refs = submodule_ref_caches; refs; refs = refs->next) 941if(!strcmp(submodule, refs->name)) 942return refs; 943 944 refs =create_ref_cache(submodule); 945 refs->next = submodule_ref_caches; 946 submodule_ref_caches = refs; 947return refs; 948} 949 950/* The length of a peeled reference line in packed-refs, including EOL: */ 951#define PEELED_LINE_LENGTH 42 952 953/* 954 * The packed-refs header line that we write out. Perhaps other 955 * traits will be added later. The trailing space is required. 956 */ 957static const char PACKED_REFS_HEADER[] = 958"# pack-refs with: peeled fully-peeled\n"; 959 960/* 961 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 962 * Return a pointer to the refname within the line (null-terminated), 963 * or NULL if there was a problem. 964 */ 965static const char*parse_ref_line(char*line,unsigned char*sha1) 966{ 967/* 968 * 42: the answer to everything. 969 * 970 * In this case, it happens to be the answer to 971 * 40 (length of sha1 hex representation) 972 * +1 (space in between hex and name) 973 * +1 (newline at the end of the line) 974 */ 975int len =strlen(line) -42; 976 977if(len <=0) 978return NULL; 979if(get_sha1_hex(line, sha1) <0) 980return NULL; 981if(!isspace(line[40])) 982return NULL; 983 line +=41; 984if(isspace(*line)) 985return NULL; 986if(line[len] !='\n') 987return NULL; 988 line[len] =0; 989 990return line; 991} 992 993/* 994 * Read f, which is a packed-refs file, into dir. 995 * 996 * A comment line of the form "# pack-refs with: " may contain zero or 997 * more traits. We interpret the traits as follows: 998 * 999 * No traits:1000 *1001 * Probably no references are peeled. But if the file contains a1002 * peeled value for a reference, we will use it.1003 *1004 * peeled:1005 *1006 * References under "refs/tags/", if they *can* be peeled, *are*1007 * peeled in this file. References outside of "refs/tags/" are1008 * probably not peeled even if they could have been, but if we find1009 * a peeled value for such a reference we will use it.1010 *1011 * fully-peeled:1012 *1013 * All references in the file that can be peeled are peeled.1014 * Inversely (and this is more important), any references in the1015 * file for which no peeled value is recorded is not peelable. This1016 * trait should typically be written alongside "peeled" for1017 * compatibility with older clients, but we do not require it1018 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1019 */1020static voidread_packed_refs(FILE*f,struct ref_dir *dir)1021{1022struct ref_entry *last = NULL;1023char refline[PATH_MAX];1024enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;10251026while(fgets(refline,sizeof(refline), f)) {1027unsigned char sha1[20];1028const char*refname;1029static const char header[] ="# pack-refs with:";10301031if(!strncmp(refline, header,sizeof(header)-1)) {1032const char*traits = refline +sizeof(header) -1;1033if(strstr(traits," fully-peeled "))1034 peeled = PEELED_FULLY;1035else if(strstr(traits," peeled "))1036 peeled = PEELED_TAGS;1037/* perhaps other traits later as well */1038continue;1039}10401041 refname =parse_ref_line(refline, sha1);1042if(refname) {1043 last =create_ref_entry(refname, sha1, REF_ISPACKED,1);1044if(peeled == PEELED_FULLY ||1045(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1046 last->flag |= REF_KNOWS_PEELED;1047add_ref(dir, last);1048continue;1049}1050if(last &&1051 refline[0] =='^'&&1052strlen(refline) == PEELED_LINE_LENGTH &&1053 refline[PEELED_LINE_LENGTH -1] =='\n'&&1054!get_sha1_hex(refline +1, sha1)) {1055hashcpy(last->u.value.peeled, sha1);1056/*1057 * Regardless of what the file header said,1058 * we definitely know the value of *this*1059 * reference:1060 */1061 last->flag |= REF_KNOWS_PEELED;1062}1063}1064}10651066/*1067 * Get the packed_ref_cache for the specified ref_cache, creating it1068 * if necessary.1069 */1070static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1071{1072const char*packed_refs_file;10731074if(*refs->name)1075 packed_refs_file =git_path_submodule(refs->name,"packed-refs");1076else1077 packed_refs_file =git_path("packed-refs");10781079if(refs->packed &&1080!stat_validity_check(&refs->packed->validity, packed_refs_file))1081clear_packed_ref_cache(refs);10821083if(!refs->packed) {1084FILE*f;10851086 refs->packed =xcalloc(1,sizeof(*refs->packed));1087acquire_packed_ref_cache(refs->packed);1088 refs->packed->root =create_dir_entry(refs,"",0,0);1089 f =fopen(packed_refs_file,"r");1090if(f) {1091stat_validity_update(&refs->packed->validity,fileno(f));1092read_packed_refs(f,get_ref_dir(refs->packed->root));1093fclose(f);1094}1095}1096return refs->packed;1097}10981099static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1100{1101returnget_ref_dir(packed_ref_cache->root);1102}11031104static struct ref_dir *get_packed_refs(struct ref_cache *refs)1105{1106returnget_packed_ref_dir(get_packed_ref_cache(refs));1107}11081109voidadd_packed_ref(const char*refname,const unsigned char*sha1)1110{1111struct packed_ref_cache *packed_ref_cache =1112get_packed_ref_cache(&ref_cache);11131114if(!packed_ref_cache->lock)1115die("internal error: packed refs not locked");1116add_ref(get_packed_ref_dir(packed_ref_cache),1117create_ref_entry(refname, sha1, REF_ISPACKED,1));1118}11191120/*1121 * Read the loose references from the namespace dirname into dir1122 * (without recursing). dirname must end with '/'. dir must be the1123 * directory entry corresponding to dirname.1124 */1125static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1126{1127struct ref_cache *refs = dir->ref_cache;1128DIR*d;1129const char*path;1130struct dirent *de;1131int dirnamelen =strlen(dirname);1132struct strbuf refname;11331134if(*refs->name)1135 path =git_path_submodule(refs->name,"%s", dirname);1136else1137 path =git_path("%s", dirname);11381139 d =opendir(path);1140if(!d)1141return;11421143strbuf_init(&refname, dirnamelen +257);1144strbuf_add(&refname, dirname, dirnamelen);11451146while((de =readdir(d)) != NULL) {1147unsigned char sha1[20];1148struct stat st;1149int flag;1150const char*refdir;11511152if(de->d_name[0] =='.')1153continue;1154if(has_extension(de->d_name,".lock"))1155continue;1156strbuf_addstr(&refname, de->d_name);1157 refdir = *refs->name1158?git_path_submodule(refs->name,"%s", refname.buf)1159:git_path("%s", refname.buf);1160if(stat(refdir, &st) <0) {1161;/* silently ignore */1162}else if(S_ISDIR(st.st_mode)) {1163strbuf_addch(&refname,'/');1164add_entry_to_dir(dir,1165create_dir_entry(refs, refname.buf,1166 refname.len,1));1167}else{1168if(*refs->name) {1169hashclr(sha1);1170 flag =0;1171if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1172hashclr(sha1);1173 flag |= REF_ISBROKEN;1174}1175}else if(read_ref_full(refname.buf, sha1,1, &flag)) {1176hashclr(sha1);1177 flag |= REF_ISBROKEN;1178}1179add_entry_to_dir(dir,1180create_ref_entry(refname.buf, sha1, flag,1));1181}1182strbuf_setlen(&refname, dirnamelen);1183}1184strbuf_release(&refname);1185closedir(d);1186}11871188static struct ref_dir *get_loose_refs(struct ref_cache *refs)1189{1190if(!refs->loose) {1191/*1192 * Mark the top-level directory complete because we1193 * are about to read the only subdirectory that can1194 * hold references:1195 */1196 refs->loose =create_dir_entry(refs,"",0,0);1197/*1198 * Create an incomplete entry for "refs/":1199 */1200add_entry_to_dir(get_ref_dir(refs->loose),1201create_dir_entry(refs,"refs/",5,1));1202}1203returnget_ref_dir(refs->loose);1204}12051206/* We allow "recursive" symbolic refs. Only within reason, though */1207#define MAXDEPTH 51208#define MAXREFLEN (1024)12091210/*1211 * Called by resolve_gitlink_ref_recursive() after it failed to read1212 * from the loose refs in ref_cache refs. Find <refname> in the1213 * packed-refs file for the submodule.1214 */1215static intresolve_gitlink_packed_ref(struct ref_cache *refs,1216const char*refname,unsigned char*sha1)1217{1218struct ref_entry *ref;1219struct ref_dir *dir =get_packed_refs(refs);12201221 ref =find_ref(dir, refname);1222if(ref == NULL)1223return-1;12241225hashcpy(sha1, ref->u.value.sha1);1226return0;1227}12281229static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1230const char*refname,unsigned char*sha1,1231int recursion)1232{1233int fd, len;1234char buffer[128], *p;1235char*path;12361237if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1238return-1;1239 path = *refs->name1240?git_path_submodule(refs->name,"%s", refname)1241:git_path("%s", refname);1242 fd =open(path, O_RDONLY);1243if(fd <0)1244returnresolve_gitlink_packed_ref(refs, refname, sha1);12451246 len =read(fd, buffer,sizeof(buffer)-1);1247close(fd);1248if(len <0)1249return-1;1250while(len &&isspace(buffer[len-1]))1251 len--;1252 buffer[len] =0;12531254/* Was it a detached head or an old-fashioned symlink? */1255if(!get_sha1_hex(buffer, sha1))1256return0;12571258/* Symref? */1259if(strncmp(buffer,"ref:",4))1260return-1;1261 p = buffer +4;1262while(isspace(*p))1263 p++;12641265returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1266}12671268intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1269{1270int len =strlen(path), retval;1271char*submodule;1272struct ref_cache *refs;12731274while(len && path[len-1] =='/')1275 len--;1276if(!len)1277return-1;1278 submodule =xstrndup(path, len);1279 refs =get_ref_cache(submodule);1280free(submodule);12811282 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1283return retval;1284}12851286/*1287 * Return the ref_entry for the given refname from the packed1288 * references. If it does not exist, return NULL.1289 */1290static struct ref_entry *get_packed_ref(const char*refname)1291{1292returnfind_ref(get_packed_refs(&ref_cache), refname);1293}12941295/*1296 * A loose ref file doesn't exist; check for a packed ref. The1297 * options are forwarded from resolve_safe_unsafe().1298 */1299static const char*handle_missing_loose_ref(const char*refname,1300unsigned char*sha1,1301int reading,1302int*flag)1303{1304struct ref_entry *entry;13051306/*1307 * The loose reference file does not exist; check for a packed1308 * reference.1309 */1310 entry =get_packed_ref(refname);1311if(entry) {1312hashcpy(sha1, entry->u.value.sha1);1313if(flag)1314*flag |= REF_ISPACKED;1315return refname;1316}1317/* The reference is not a packed reference, either. */1318if(reading) {1319return NULL;1320}else{1321hashclr(sha1);1322return refname;1323}1324}13251326const char*resolve_ref_unsafe(const char*refname,unsigned char*sha1,int reading,int*flag)1327{1328int depth = MAXDEPTH;1329 ssize_t len;1330char buffer[256];1331static char refname_buffer[256];13321333if(flag)1334*flag =0;13351336if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1337return NULL;13381339for(;;) {1340char path[PATH_MAX];1341struct stat st;1342char*buf;1343int fd;13441345if(--depth <0)1346return NULL;13471348git_snpath(path,sizeof(path),"%s", refname);13491350/*1351 * We might have to loop back here to avoid a race1352 * condition: first we lstat() the file, then we try1353 * to read it as a link or as a file. But if somebody1354 * changes the type of the file (file <-> directory1355 * <-> symlink) between the lstat() and reading, then1356 * we don't want to report that as an error but rather1357 * try again starting with the lstat().1358 */1359 stat_ref:1360if(lstat(path, &st) <0) {1361if(errno == ENOENT)1362returnhandle_missing_loose_ref(refname, sha1,1363 reading, flag);1364else1365return NULL;1366}13671368/* Follow "normalized" - ie "refs/.." symlinks by hand */1369if(S_ISLNK(st.st_mode)) {1370 len =readlink(path, buffer,sizeof(buffer)-1);1371if(len <0) {1372if(errno == ENOENT || errno == EINVAL)1373/* inconsistent with lstat; retry */1374goto stat_ref;1375else1376return NULL;1377}1378 buffer[len] =0;1379if(starts_with(buffer,"refs/") &&1380!check_refname_format(buffer,0)) {1381strcpy(refname_buffer, buffer);1382 refname = refname_buffer;1383if(flag)1384*flag |= REF_ISSYMREF;1385continue;1386}1387}13881389/* Is it a directory? */1390if(S_ISDIR(st.st_mode)) {1391 errno = EISDIR;1392return NULL;1393}13941395/*1396 * Anything else, just open it and try to use it as1397 * a ref1398 */1399 fd =open(path, O_RDONLY);1400if(fd <0) {1401if(errno == ENOENT)1402/* inconsistent with lstat; retry */1403goto stat_ref;1404else1405return NULL;1406}1407 len =read_in_full(fd, buffer,sizeof(buffer)-1);1408close(fd);1409if(len <0)1410return NULL;1411while(len &&isspace(buffer[len-1]))1412 len--;1413 buffer[len] ='\0';14141415/*1416 * Is it a symbolic ref?1417 */1418if(!starts_with(buffer,"ref:")) {1419/*1420 * Please note that FETCH_HEAD has a second1421 * line containing other data.1422 */1423if(get_sha1_hex(buffer, sha1) ||1424(buffer[40] !='\0'&& !isspace(buffer[40]))) {1425if(flag)1426*flag |= REF_ISBROKEN;1427return NULL;1428}1429return refname;1430}1431if(flag)1432*flag |= REF_ISSYMREF;1433 buf = buffer +4;1434while(isspace(*buf))1435 buf++;1436if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1437if(flag)1438*flag |= REF_ISBROKEN;1439return NULL;1440}1441 refname =strcpy(refname_buffer, buf);1442}1443}14441445char*resolve_refdup(const char*ref,unsigned char*sha1,int reading,int*flag)1446{1447const char*ret =resolve_ref_unsafe(ref, sha1, reading, flag);1448return ret ?xstrdup(ret) : NULL;1449}14501451/* The argument to filter_refs */1452struct ref_filter {1453const char*pattern;1454 each_ref_fn *fn;1455void*cb_data;1456};14571458intread_ref_full(const char*refname,unsigned char*sha1,int reading,int*flags)1459{1460if(resolve_ref_unsafe(refname, sha1, reading, flags))1461return0;1462return-1;1463}14641465intread_ref(const char*refname,unsigned char*sha1)1466{1467returnread_ref_full(refname, sha1,1, NULL);1468}14691470intref_exists(const char*refname)1471{1472unsigned char sha1[20];1473return!!resolve_ref_unsafe(refname, sha1,1, NULL);1474}14751476static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1477void*data)1478{1479struct ref_filter *filter = (struct ref_filter *)data;1480if(wildmatch(filter->pattern, refname,0, NULL))1481return0;1482return filter->fn(refname, sha1, flags, filter->cb_data);1483}14841485enum peel_status {1486/* object was peeled successfully: */1487 PEEL_PEELED =0,14881489/*1490 * object cannot be peeled because the named object (or an1491 * object referred to by a tag in the peel chain), does not1492 * exist.1493 */1494 PEEL_INVALID = -1,14951496/* object cannot be peeled because it is not a tag: */1497 PEEL_NON_TAG = -2,14981499/* ref_entry contains no peeled value because it is a symref: */1500 PEEL_IS_SYMREF = -3,15011502/*1503 * ref_entry cannot be peeled because it is broken (i.e., the1504 * symbolic reference cannot even be resolved to an object1505 * name):1506 */1507 PEEL_BROKEN = -41508};15091510/*1511 * Peel the named object; i.e., if the object is a tag, resolve the1512 * tag recursively until a non-tag is found. If successful, store the1513 * result to sha1 and return PEEL_PEELED. If the object is not a tag1514 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1515 * and leave sha1 unchanged.1516 */1517static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1518{1519struct object *o =lookup_unknown_object(name);15201521if(o->type == OBJ_NONE) {1522int type =sha1_object_info(name, NULL);1523if(type <0)1524return PEEL_INVALID;1525 o->type = type;1526}15271528if(o->type != OBJ_TAG)1529return PEEL_NON_TAG;15301531 o =deref_tag_noverify(o);1532if(!o)1533return PEEL_INVALID;15341535hashcpy(sha1, o->sha1);1536return PEEL_PEELED;1537}15381539/*1540 * Peel the entry (if possible) and return its new peel_status. If1541 * repeel is true, re-peel the entry even if there is an old peeled1542 * value that is already stored in it.1543 *1544 * It is OK to call this function with a packed reference entry that1545 * might be stale and might even refer to an object that has since1546 * been garbage-collected. In such a case, if the entry has1547 * REF_KNOWS_PEELED then leave the status unchanged and return1548 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1549 */1550static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1551{1552enum peel_status status;15531554if(entry->flag & REF_KNOWS_PEELED) {1555if(repeel) {1556 entry->flag &= ~REF_KNOWS_PEELED;1557hashclr(entry->u.value.peeled);1558}else{1559returnis_null_sha1(entry->u.value.peeled) ?1560 PEEL_NON_TAG : PEEL_PEELED;1561}1562}1563if(entry->flag & REF_ISBROKEN)1564return PEEL_BROKEN;1565if(entry->flag & REF_ISSYMREF)1566return PEEL_IS_SYMREF;15671568 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1569if(status == PEEL_PEELED || status == PEEL_NON_TAG)1570 entry->flag |= REF_KNOWS_PEELED;1571return status;1572}15731574intpeel_ref(const char*refname,unsigned char*sha1)1575{1576int flag;1577unsigned char base[20];15781579if(current_ref && (current_ref->name == refname1580|| !strcmp(current_ref->name, refname))) {1581if(peel_entry(current_ref,0))1582return-1;1583hashcpy(sha1, current_ref->u.value.peeled);1584return0;1585}15861587if(read_ref_full(refname, base,1, &flag))1588return-1;15891590/*1591 * If the reference is packed, read its ref_entry from the1592 * cache in the hope that we already know its peeled value.1593 * We only try this optimization on packed references because1594 * (a) forcing the filling of the loose reference cache could1595 * be expensive and (b) loose references anyway usually do not1596 * have REF_KNOWS_PEELED.1597 */1598if(flag & REF_ISPACKED) {1599struct ref_entry *r =get_packed_ref(refname);1600if(r) {1601if(peel_entry(r,0))1602return-1;1603hashcpy(sha1, r->u.value.peeled);1604return0;1605}1606}16071608returnpeel_object(base, sha1);1609}16101611struct warn_if_dangling_data {1612FILE*fp;1613const char*refname;1614const struct string_list *refnames;1615const char*msg_fmt;1616};16171618static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1619int flags,void*cb_data)1620{1621struct warn_if_dangling_data *d = cb_data;1622const char*resolves_to;1623unsigned char junk[20];16241625if(!(flags & REF_ISSYMREF))1626return0;16271628 resolves_to =resolve_ref_unsafe(refname, junk,0, NULL);1629if(!resolves_to1630|| (d->refname1631?strcmp(resolves_to, d->refname)1632: !string_list_has_string(d->refnames, resolves_to))) {1633return0;1634}16351636fprintf(d->fp, d->msg_fmt, refname);1637fputc('\n', d->fp);1638return0;1639}16401641voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1642{1643struct warn_if_dangling_data data;16441645 data.fp = fp;1646 data.refname = refname;1647 data.refnames = NULL;1648 data.msg_fmt = msg_fmt;1649for_each_rawref(warn_if_dangling_symref, &data);1650}16511652voidwarn_dangling_symrefs(FILE*fp,const char*msg_fmt,const struct string_list *refnames)1653{1654struct warn_if_dangling_data data;16551656 data.fp = fp;1657 data.refname = NULL;1658 data.refnames = refnames;1659 data.msg_fmt = msg_fmt;1660for_each_rawref(warn_if_dangling_symref, &data);1661}16621663/*1664 * Call fn for each reference in the specified ref_cache, omitting1665 * references not in the containing_dir of base. fn is called for all1666 * references, including broken ones. If fn ever returns a non-zero1667 * value, stop the iteration and return that value; otherwise, return1668 * 0.1669 */1670static intdo_for_each_entry(struct ref_cache *refs,const char*base,1671 each_ref_entry_fn fn,void*cb_data)1672{1673struct packed_ref_cache *packed_ref_cache;1674struct ref_dir *loose_dir;1675struct ref_dir *packed_dir;1676int retval =0;16771678/*1679 * We must make sure that all loose refs are read before accessing the1680 * packed-refs file; this avoids a race condition in which loose refs1681 * are migrated to the packed-refs file by a simultaneous process, but1682 * our in-memory view is from before the migration. get_packed_ref_cache()1683 * takes care of making sure our view is up to date with what is on1684 * disk.1685 */1686 loose_dir =get_loose_refs(refs);1687if(base && *base) {1688 loose_dir =find_containing_dir(loose_dir, base,0);1689}1690if(loose_dir)1691prime_ref_dir(loose_dir);16921693 packed_ref_cache =get_packed_ref_cache(refs);1694acquire_packed_ref_cache(packed_ref_cache);1695 packed_dir =get_packed_ref_dir(packed_ref_cache);1696if(base && *base) {1697 packed_dir =find_containing_dir(packed_dir, base,0);1698}16991700if(packed_dir && loose_dir) {1701sort_ref_dir(packed_dir);1702sort_ref_dir(loose_dir);1703 retval =do_for_each_entry_in_dirs(1704 packed_dir, loose_dir, fn, cb_data);1705}else if(packed_dir) {1706sort_ref_dir(packed_dir);1707 retval =do_for_each_entry_in_dir(1708 packed_dir,0, fn, cb_data);1709}else if(loose_dir) {1710sort_ref_dir(loose_dir);1711 retval =do_for_each_entry_in_dir(1712 loose_dir,0, fn, cb_data);1713}17141715release_packed_ref_cache(packed_ref_cache);1716return retval;1717}17181719/*1720 * Call fn for each reference in the specified ref_cache for which the1721 * refname begins with base. If trim is non-zero, then trim that many1722 * characters off the beginning of each refname before passing the1723 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1724 * broken references in the iteration. If fn ever returns a non-zero1725 * value, stop the iteration and return that value; otherwise, return1726 * 0.1727 */1728static intdo_for_each_ref(struct ref_cache *refs,const char*base,1729 each_ref_fn fn,int trim,int flags,void*cb_data)1730{1731struct ref_entry_cb data;1732 data.base = base;1733 data.trim = trim;1734 data.flags = flags;1735 data.fn = fn;1736 data.cb_data = cb_data;17371738returndo_for_each_entry(refs, base, do_one_ref, &data);1739}17401741static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1742{1743unsigned char sha1[20];1744int flag;17451746if(submodule) {1747if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1748returnfn("HEAD", sha1,0, cb_data);17491750return0;1751}17521753if(!read_ref_full("HEAD", sha1,1, &flag))1754returnfn("HEAD", sha1, flag, cb_data);17551756return0;1757}17581759inthead_ref(each_ref_fn fn,void*cb_data)1760{1761returndo_head_ref(NULL, fn, cb_data);1762}17631764inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1765{1766returndo_head_ref(submodule, fn, cb_data);1767}17681769intfor_each_ref(each_ref_fn fn,void*cb_data)1770{1771returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1772}17731774intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1775{1776returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1777}17781779intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1780{1781returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);1782}17831784intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1785 each_ref_fn fn,void*cb_data)1786{1787returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);1788}17891790intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1791{1792returnfor_each_ref_in("refs/tags/", fn, cb_data);1793}17941795intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1796{1797returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1798}17991800intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1801{1802returnfor_each_ref_in("refs/heads/", fn, cb_data);1803}18041805intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1806{1807returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);1808}18091810intfor_each_remote_ref(each_ref_fn fn,void*cb_data)1811{1812returnfor_each_ref_in("refs/remotes/", fn, cb_data);1813}18141815intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1816{1817returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);1818}18191820intfor_each_replace_ref(each_ref_fn fn,void*cb_data)1821{1822returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);1823}18241825inthead_ref_namespaced(each_ref_fn fn,void*cb_data)1826{1827struct strbuf buf = STRBUF_INIT;1828int ret =0;1829unsigned char sha1[20];1830int flag;18311832strbuf_addf(&buf,"%sHEAD",get_git_namespace());1833if(!read_ref_full(buf.buf, sha1,1, &flag))1834 ret =fn(buf.buf, sha1, flag, cb_data);1835strbuf_release(&buf);18361837return ret;1838}18391840intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)1841{1842struct strbuf buf = STRBUF_INIT;1843int ret;1844strbuf_addf(&buf,"%srefs/",get_git_namespace());1845 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);1846strbuf_release(&buf);1847return ret;1848}18491850intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,1851const char*prefix,void*cb_data)1852{1853struct strbuf real_pattern = STRBUF_INIT;1854struct ref_filter filter;1855int ret;18561857if(!prefix && !starts_with(pattern,"refs/"))1858strbuf_addstr(&real_pattern,"refs/");1859else if(prefix)1860strbuf_addstr(&real_pattern, prefix);1861strbuf_addstr(&real_pattern, pattern);18621863if(!has_glob_specials(pattern)) {1864/* Append implied '/' '*' if not present. */1865if(real_pattern.buf[real_pattern.len -1] !='/')1866strbuf_addch(&real_pattern,'/');1867/* No need to check for '*', there is none. */1868strbuf_addch(&real_pattern,'*');1869}18701871 filter.pattern = real_pattern.buf;1872 filter.fn = fn;1873 filter.cb_data = cb_data;1874 ret =for_each_ref(filter_refs, &filter);18751876strbuf_release(&real_pattern);1877return ret;1878}18791880intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)1881{1882returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);1883}18841885intfor_each_rawref(each_ref_fn fn,void*cb_data)1886{1887returndo_for_each_ref(&ref_cache,"", fn,0,1888 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1889}18901891const char*prettify_refname(const char*name)1892{1893return name + (1894starts_with(name,"refs/heads/") ?11:1895starts_with(name,"refs/tags/") ?10:1896starts_with(name,"refs/remotes/") ?13:18970);1898}18991900static const char*ref_rev_parse_rules[] = {1901"%.*s",1902"refs/%.*s",1903"refs/tags/%.*s",1904"refs/heads/%.*s",1905"refs/remotes/%.*s",1906"refs/remotes/%.*s/HEAD",1907 NULL1908};19091910intrefname_match(const char*abbrev_name,const char*full_name)1911{1912const char**p;1913const int abbrev_name_len =strlen(abbrev_name);19141915for(p = ref_rev_parse_rules; *p; p++) {1916if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {1917return1;1918}1919}19201921return0;1922}19231924static struct ref_lock *verify_lock(struct ref_lock *lock,1925const unsigned char*old_sha1,int mustexist)1926{1927if(read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {1928error("Can't verify ref%s", lock->ref_name);1929unlock_ref(lock);1930return NULL;1931}1932if(hashcmp(lock->old_sha1, old_sha1)) {1933error("Ref%sis at%sbut expected%s", lock->ref_name,1934sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));1935unlock_ref(lock);1936return NULL;1937}1938return lock;1939}19401941static intremove_empty_directories(const char*file)1942{1943/* we want to create a file but there is a directory there;1944 * if that is an empty directory (or a directory that contains1945 * only empty directories), remove them.1946 */1947struct strbuf path;1948int result;19491950strbuf_init(&path,20);1951strbuf_addstr(&path, file);19521953 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);19541955strbuf_release(&path);19561957return result;1958}19591960/*1961 * *string and *len will only be substituted, and *string returned (for1962 * later free()ing) if the string passed in is a magic short-hand form1963 * to name a branch.1964 */1965static char*substitute_branch_name(const char**string,int*len)1966{1967struct strbuf buf = STRBUF_INIT;1968int ret =interpret_branch_name(*string, *len, &buf);19691970if(ret == *len) {1971size_t size;1972*string =strbuf_detach(&buf, &size);1973*len = size;1974return(char*)*string;1975}19761977return NULL;1978}19791980intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)1981{1982char*last_branch =substitute_branch_name(&str, &len);1983const char**p, *r;1984int refs_found =0;19851986*ref = NULL;1987for(p = ref_rev_parse_rules; *p; p++) {1988char fullref[PATH_MAX];1989unsigned char sha1_from_ref[20];1990unsigned char*this_result;1991int flag;19921993 this_result = refs_found ? sha1_from_ref : sha1;1994mksnpath(fullref,sizeof(fullref), *p, len, str);1995 r =resolve_ref_unsafe(fullref, this_result,1, &flag);1996if(r) {1997if(!refs_found++)1998*ref =xstrdup(r);1999if(!warn_ambiguous_refs)2000break;2001}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {2002warning("ignoring dangling symref%s.", fullref);2003}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {2004warning("ignoring broken ref%s.", fullref);2005}2006}2007free(last_branch);2008return refs_found;2009}20102011intdwim_log(const char*str,int len,unsigned char*sha1,char**log)2012{2013char*last_branch =substitute_branch_name(&str, &len);2014const char**p;2015int logs_found =0;20162017*log = NULL;2018for(p = ref_rev_parse_rules; *p; p++) {2019unsigned char hash[20];2020char path[PATH_MAX];2021const char*ref, *it;20222023mksnpath(path,sizeof(path), *p, len, str);2024 ref =resolve_ref_unsafe(path, hash,1, NULL);2025if(!ref)2026continue;2027if(reflog_exists(path))2028 it = path;2029else if(strcmp(ref, path) &&reflog_exists(ref))2030 it = ref;2031else2032continue;2033if(!logs_found++) {2034*log =xstrdup(it);2035hashcpy(sha1, hash);2036}2037if(!warn_ambiguous_refs)2038break;2039}2040free(last_branch);2041return logs_found;2042}20432044static struct ref_lock *lock_ref_sha1_basic(const char*refname,2045const unsigned char*old_sha1,2046int flags,int*type_p)2047{2048char*ref_file;2049const char*orig_refname = refname;2050struct ref_lock *lock;2051int last_errno =0;2052int type, lflags;2053int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2054int missing =0;2055int attempts_remaining =3;20562057 lock =xcalloc(1,sizeof(struct ref_lock));2058 lock->lock_fd = -1;20592060 refname =resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);2061if(!refname && errno == EISDIR) {2062/* we are trying to lock foo but we used to2063 * have foo/bar which now does not exist;2064 * it is normal for the empty directory 'foo'2065 * to remain.2066 */2067 ref_file =git_path("%s", orig_refname);2068if(remove_empty_directories(ref_file)) {2069 last_errno = errno;2070error("there are still refs under '%s'", orig_refname);2071goto error_return;2072}2073 refname =resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);2074}2075if(type_p)2076*type_p = type;2077if(!refname) {2078 last_errno = errno;2079error("unable to resolve reference%s:%s",2080 orig_refname,strerror(errno));2081goto error_return;2082}2083 missing =is_null_sha1(lock->old_sha1);2084/* When the ref did not exist and we are creating it,2085 * make sure there is no existing ref that is packed2086 * whose name begins with our refname, nor a ref whose2087 * name is a proper prefix of our refname.2088 */2089if(missing &&2090!is_refname_available(refname, NULL,get_packed_refs(&ref_cache))) {2091 last_errno = ENOTDIR;2092goto error_return;2093}20942095 lock->lk =xcalloc(1,sizeof(struct lock_file));20962097 lflags =0;2098if(flags & REF_NODEREF) {2099 refname = orig_refname;2100 lflags |= LOCK_NODEREF;2101}2102 lock->ref_name =xstrdup(refname);2103 lock->orig_ref_name =xstrdup(orig_refname);2104 ref_file =git_path("%s", refname);2105if(missing)2106 lock->force_write =1;2107if((flags & REF_NODEREF) && (type & REF_ISSYMREF))2108 lock->force_write =1;21092110 retry:2111switch(safe_create_leading_directories(ref_file)) {2112case SCLD_OK:2113break;/* success */2114case SCLD_VANISHED:2115if(--attempts_remaining >0)2116goto retry;2117/* fall through */2118default:2119 last_errno = errno;2120error("unable to create directory for%s", ref_file);2121goto error_return;2122}21232124 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);2125if(lock->lock_fd <0) {2126if(errno == ENOENT && --attempts_remaining >0)2127/*2128 * Maybe somebody just deleted one of the2129 * directories leading to ref_file. Try2130 * again:2131 */2132goto retry;2133else2134unable_to_lock_index_die(ref_file, errno);2135}2136return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;21372138 error_return:2139unlock_ref(lock);2140 errno = last_errno;2141return NULL;2142}21432144struct ref_lock *lock_ref_sha1(const char*refname,const unsigned char*old_sha1)2145{2146char refpath[PATH_MAX];2147if(check_refname_format(refname,0))2148return NULL;2149strcpy(refpath,mkpath("refs/%s", refname));2150returnlock_ref_sha1_basic(refpath, old_sha1,0, NULL);2151}21522153struct ref_lock *lock_any_ref_for_update(const char*refname,2154const unsigned char*old_sha1,2155int flags,int*type_p)2156{2157if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))2158return NULL;2159returnlock_ref_sha1_basic(refname, old_sha1, flags, type_p);2160}21612162/*2163 * Write an entry to the packed-refs file for the specified refname.2164 * If peeled is non-NULL, write it as the entry's peeled value.2165 */2166static voidwrite_packed_entry(int fd,char*refname,unsigned char*sha1,2167unsigned char*peeled)2168{2169char line[PATH_MAX +100];2170int len;21712172 len =snprintf(line,sizeof(line),"%s %s\n",2173sha1_to_hex(sha1), refname);2174/* this should not happen but just being defensive */2175if(len >sizeof(line))2176die("too long a refname '%s'", refname);2177write_or_die(fd, line, len);21782179if(peeled) {2180if(snprintf(line,sizeof(line),"^%s\n",2181sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)2182die("internal error");2183write_or_die(fd, line, PEELED_LINE_LENGTH);2184}2185}21862187/*2188 * An each_ref_entry_fn that writes the entry to a packed-refs file.2189 */2190static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2191{2192int*fd = cb_data;2193enum peel_status peel_status =peel_entry(entry,0);21942195if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2196error("internal error:%sis not a valid packed reference!",2197 entry->name);2198write_packed_entry(*fd, entry->name, entry->u.value.sha1,2199 peel_status == PEEL_PEELED ?2200 entry->u.value.peeled : NULL);2201return0;2202}22032204intlock_packed_refs(int flags)2205{2206struct packed_ref_cache *packed_ref_cache;22072208if(hold_lock_file_for_update(&packlock,git_path("packed-refs"), flags) <0)2209return-1;2210/*2211 * Get the current packed-refs while holding the lock. If the2212 * packed-refs file has been modified since we last read it,2213 * this will automatically invalidate the cache and re-read2214 * the packed-refs file.2215 */2216 packed_ref_cache =get_packed_ref_cache(&ref_cache);2217 packed_ref_cache->lock = &packlock;2218/* Increment the reference count to prevent it from being freed: */2219acquire_packed_ref_cache(packed_ref_cache);2220return0;2221}22222223intcommit_packed_refs(void)2224{2225struct packed_ref_cache *packed_ref_cache =2226get_packed_ref_cache(&ref_cache);2227int error =0;22282229if(!packed_ref_cache->lock)2230die("internal error: packed-refs not locked");2231write_or_die(packed_ref_cache->lock->fd,2232 PACKED_REFS_HEADER,strlen(PACKED_REFS_HEADER));22332234do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),22350, write_packed_entry_fn,2236&packed_ref_cache->lock->fd);2237if(commit_lock_file(packed_ref_cache->lock))2238 error = -1;2239 packed_ref_cache->lock = NULL;2240release_packed_ref_cache(packed_ref_cache);2241return error;2242}22432244voidrollback_packed_refs(void)2245{2246struct packed_ref_cache *packed_ref_cache =2247get_packed_ref_cache(&ref_cache);22482249if(!packed_ref_cache->lock)2250die("internal error: packed-refs not locked");2251rollback_lock_file(packed_ref_cache->lock);2252 packed_ref_cache->lock = NULL;2253release_packed_ref_cache(packed_ref_cache);2254clear_packed_ref_cache(&ref_cache);2255}22562257struct ref_to_prune {2258struct ref_to_prune *next;2259unsigned char sha1[20];2260char name[FLEX_ARRAY];2261};22622263struct pack_refs_cb_data {2264unsigned int flags;2265struct ref_dir *packed_refs;2266struct ref_to_prune *ref_to_prune;2267};22682269/*2270 * An each_ref_entry_fn that is run over loose references only. If2271 * the loose reference can be packed, add an entry in the packed ref2272 * cache. If the reference should be pruned, also add it to2273 * ref_to_prune in the pack_refs_cb_data.2274 */2275static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2276{2277struct pack_refs_cb_data *cb = cb_data;2278enum peel_status peel_status;2279struct ref_entry *packed_entry;2280int is_tag_ref =starts_with(entry->name,"refs/tags/");22812282/* ALWAYS pack tags */2283if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2284return0;22852286/* Do not pack symbolic or broken refs: */2287if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2288return0;22892290/* Add a packed ref cache entry equivalent to the loose entry. */2291 peel_status =peel_entry(entry,1);2292if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2293die("internal error peeling reference%s(%s)",2294 entry->name,sha1_to_hex(entry->u.value.sha1));2295 packed_entry =find_ref(cb->packed_refs, entry->name);2296if(packed_entry) {2297/* Overwrite existing packed entry with info from loose entry */2298 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2299hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2300}else{2301 packed_entry =create_ref_entry(entry->name, entry->u.value.sha1,2302 REF_ISPACKED | REF_KNOWS_PEELED,0);2303add_ref(cb->packed_refs, packed_entry);2304}2305hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);23062307/* Schedule the loose reference for pruning if requested. */2308if((cb->flags & PACK_REFS_PRUNE)) {2309int namelen =strlen(entry->name) +1;2310struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2311hashcpy(n->sha1, entry->u.value.sha1);2312strcpy(n->name, entry->name);2313 n->next = cb->ref_to_prune;2314 cb->ref_to_prune = n;2315}2316return0;2317}23182319/*2320 * Remove empty parents, but spare refs/ and immediate subdirs.2321 * Note: munges *name.2322 */2323static voidtry_remove_empty_parents(char*name)2324{2325char*p, *q;2326int i;2327 p = name;2328for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2329while(*p && *p !='/')2330 p++;2331/* tolerate duplicate slashes; see check_refname_format() */2332while(*p =='/')2333 p++;2334}2335for(q = p; *q; q++)2336;2337while(1) {2338while(q > p && *q !='/')2339 q--;2340while(q > p && *(q-1) =='/')2341 q--;2342if(q == p)2343break;2344*q ='\0';2345if(rmdir(git_path("%s", name)))2346break;2347}2348}23492350/* make sure nobody touched the ref, and unlink */2351static voidprune_ref(struct ref_to_prune *r)2352{2353struct ref_lock *lock =lock_ref_sha1(r->name +5, r->sha1);23542355if(lock) {2356unlink_or_warn(git_path("%s", r->name));2357unlock_ref(lock);2358try_remove_empty_parents(r->name);2359}2360}23612362static voidprune_refs(struct ref_to_prune *r)2363{2364while(r) {2365prune_ref(r);2366 r = r->next;2367}2368}23692370intpack_refs(unsigned int flags)2371{2372struct pack_refs_cb_data cbdata;23732374memset(&cbdata,0,sizeof(cbdata));2375 cbdata.flags = flags;23762377lock_packed_refs(LOCK_DIE_ON_ERROR);2378 cbdata.packed_refs =get_packed_refs(&ref_cache);23792380do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2381 pack_if_possible_fn, &cbdata);23822383if(commit_packed_refs())2384die_errno("unable to overwrite old ref-pack file");23852386prune_refs(cbdata.ref_to_prune);2387return0;2388}23892390/*2391 * If entry is no longer needed in packed-refs, add it to the string2392 * list pointed to by cb_data. Reasons for deleting entries:2393 *2394 * - Entry is broken.2395 * - Entry is overridden by a loose ref.2396 * - Entry does not point at a valid object.2397 *2398 * In the first and third cases, also emit an error message because these2399 * are indications of repository corruption.2400 */2401static intcurate_packed_ref_fn(struct ref_entry *entry,void*cb_data)2402{2403struct string_list *refs_to_delete = cb_data;24042405if(entry->flag & REF_ISBROKEN) {2406/* This shouldn't happen to packed refs. */2407error("%sis broken!", entry->name);2408string_list_append(refs_to_delete, entry->name);2409return0;2410}2411if(!has_sha1_file(entry->u.value.sha1)) {2412unsigned char sha1[20];2413int flags;24142415if(read_ref_full(entry->name, sha1,0, &flags))2416/* We should at least have found the packed ref. */2417die("Internal error");2418if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2419/*2420 * This packed reference is overridden by a2421 * loose reference, so it is OK that its value2422 * is no longer valid; for example, it might2423 * refer to an object that has been garbage2424 * collected. For this purpose we don't even2425 * care whether the loose reference itself is2426 * invalid, broken, symbolic, etc. Silently2427 * remove the packed reference.2428 */2429string_list_append(refs_to_delete, entry->name);2430return0;2431}2432/*2433 * There is no overriding loose reference, so the fact2434 * that this reference doesn't refer to a valid object2435 * indicates some kind of repository corruption.2436 * Report the problem, then omit the reference from2437 * the output.2438 */2439error("%sdoes not point to a valid object!", entry->name);2440string_list_append(refs_to_delete, entry->name);2441return0;2442}24432444return0;2445}24462447intrepack_without_refs(const char**refnames,int n)2448{2449struct ref_dir *packed;2450struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2451struct string_list_item *ref_to_delete;2452int i, removed =0;24532454/* Look for a packed ref */2455for(i =0; i < n; i++)2456if(get_packed_ref(refnames[i]))2457break;24582459/* Avoid locking if we have nothing to do */2460if(i == n)2461return0;/* no refname exists in packed refs */24622463if(lock_packed_refs(0)) {2464unable_to_lock_error(git_path("packed-refs"), errno);2465returnerror("cannot delete '%s' from packed refs", refnames[i]);2466}2467 packed =get_packed_refs(&ref_cache);24682469/* Remove refnames from the cache */2470for(i =0; i < n; i++)2471if(remove_entry(packed, refnames[i]) != -1)2472 removed =1;2473if(!removed) {2474/*2475 * All packed entries disappeared while we were2476 * acquiring the lock.2477 */2478rollback_packed_refs();2479return0;2480}24812482/* Remove any other accumulated cruft */2483do_for_each_entry_in_dir(packed,0, curate_packed_ref_fn, &refs_to_delete);2484for_each_string_list_item(ref_to_delete, &refs_to_delete) {2485if(remove_entry(packed, ref_to_delete->string) == -1)2486die("internal error");2487}24882489/* Write what remains */2490returncommit_packed_refs();2491}24922493static intrepack_without_ref(const char*refname)2494{2495returnrepack_without_refs(&refname,1);2496}24972498static intdelete_ref_loose(struct ref_lock *lock,int flag)2499{2500if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2501/* loose */2502int err, i =strlen(lock->lk->filename) -5;/* .lock */25032504 lock->lk->filename[i] =0;2505 err =unlink_or_warn(lock->lk->filename);2506 lock->lk->filename[i] ='.';2507if(err && errno != ENOENT)2508return1;2509}2510return0;2511}25122513intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2514{2515struct ref_lock *lock;2516int ret =0, flag =0;25172518 lock =lock_ref_sha1_basic(refname, sha1, delopt, &flag);2519if(!lock)2520return1;2521 ret |=delete_ref_loose(lock, flag);25222523/* removing the loose one could have resurrected an earlier2524 * packed one. Also, if it was not loose we need to repack2525 * without it.2526 */2527 ret |=repack_without_ref(lock->ref_name);25282529unlink_or_warn(git_path("logs/%s", lock->ref_name));2530clear_loose_ref_cache(&ref_cache);2531unlock_ref(lock);2532return ret;2533}25342535/*2536 * People using contrib's git-new-workdir have .git/logs/refs ->2537 * /some/other/path/.git/logs/refs, and that may live on another device.2538 *2539 * IOW, to avoid cross device rename errors, the temporary renamed log must2540 * live into logs/refs.2541 */2542#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"25432544static intrename_tmp_log(const char*newrefname)2545{2546int attempts_remaining =4;25472548 retry:2549switch(safe_create_leading_directories(git_path("logs/%s", newrefname))) {2550case SCLD_OK:2551break;/* success */2552case SCLD_VANISHED:2553if(--attempts_remaining >0)2554goto retry;2555/* fall through */2556default:2557error("unable to create directory for%s", newrefname);2558return-1;2559}25602561if(rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2562if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2563/*2564 * rename(a, b) when b is an existing2565 * directory ought to result in ISDIR, but2566 * Solaris 5.8 gives ENOTDIR. Sheesh.2567 */2568if(remove_empty_directories(git_path("logs/%s", newrefname))) {2569error("Directory not empty: logs/%s", newrefname);2570return-1;2571}2572goto retry;2573}else if(errno == ENOENT && --attempts_remaining >0) {2574/*2575 * Maybe another process just deleted one of2576 * the directories in the path to newrefname.2577 * Try again from the beginning.2578 */2579goto retry;2580}else{2581error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2582 newrefname,strerror(errno));2583return-1;2584}2585}2586return0;2587}25882589intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2590{2591unsigned char sha1[20], orig_sha1[20];2592int flag =0, logmoved =0;2593struct ref_lock *lock;2594struct stat loginfo;2595int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2596const char*symref = NULL;25972598if(log &&S_ISLNK(loginfo.st_mode))2599returnerror("reflog for%sis a symlink", oldrefname);26002601 symref =resolve_ref_unsafe(oldrefname, orig_sha1,1, &flag);2602if(flag & REF_ISSYMREF)2603returnerror("refname%sis a symbolic ref, renaming it is not supported",2604 oldrefname);2605if(!symref)2606returnerror("refname%snot found", oldrefname);26072608if(!is_refname_available(newrefname, oldrefname,get_packed_refs(&ref_cache)))2609return1;26102611if(!is_refname_available(newrefname, oldrefname,get_loose_refs(&ref_cache)))2612return1;26132614if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2615returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2616 oldrefname,strerror(errno));26172618if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2619error("unable to delete old%s", oldrefname);2620goto rollback;2621}26222623if(!read_ref_full(newrefname, sha1,1, &flag) &&2624delete_ref(newrefname, sha1, REF_NODEREF)) {2625if(errno==EISDIR) {2626if(remove_empty_directories(git_path("%s", newrefname))) {2627error("Directory not empty:%s", newrefname);2628goto rollback;2629}2630}else{2631error("unable to delete existing%s", newrefname);2632goto rollback;2633}2634}26352636if(log &&rename_tmp_log(newrefname))2637goto rollback;26382639 logmoved = log;26402641 lock =lock_ref_sha1_basic(newrefname, NULL,0, NULL);2642if(!lock) {2643error("unable to lock%sfor update", newrefname);2644goto rollback;2645}2646 lock->force_write =1;2647hashcpy(lock->old_sha1, orig_sha1);2648if(write_ref_sha1(lock, orig_sha1, logmsg)) {2649error("unable to write current sha1 into%s", newrefname);2650goto rollback;2651}26522653return0;26542655 rollback:2656 lock =lock_ref_sha1_basic(oldrefname, NULL,0, NULL);2657if(!lock) {2658error("unable to lock%sfor rollback", oldrefname);2659goto rollbacklog;2660}26612662 lock->force_write =1;2663 flag = log_all_ref_updates;2664 log_all_ref_updates =0;2665if(write_ref_sha1(lock, orig_sha1, NULL))2666error("unable to write current sha1 into%s", oldrefname);2667 log_all_ref_updates = flag;26682669 rollbacklog:2670if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2671error("unable to restore logfile%sfrom%s:%s",2672 oldrefname, newrefname,strerror(errno));2673if(!logmoved && log &&2674rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2675error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2676 oldrefname,strerror(errno));26772678return1;2679}26802681intclose_ref(struct ref_lock *lock)2682{2683if(close_lock_file(lock->lk))2684return-1;2685 lock->lock_fd = -1;2686return0;2687}26882689intcommit_ref(struct ref_lock *lock)2690{2691if(commit_lock_file(lock->lk))2692return-1;2693 lock->lock_fd = -1;2694return0;2695}26962697voidunlock_ref(struct ref_lock *lock)2698{2699/* Do not free lock->lk -- atexit() still looks at them */2700if(lock->lk)2701rollback_lock_file(lock->lk);2702free(lock->ref_name);2703free(lock->orig_ref_name);2704free(lock);2705}27062707/*2708 * copy the reflog message msg to buf, which has been allocated sufficiently2709 * large, while cleaning up the whitespaces. Especially, convert LF to space,2710 * because reflog file is one line per entry.2711 */2712static intcopy_msg(char*buf,const char*msg)2713{2714char*cp = buf;2715char c;2716int wasspace =1;27172718*cp++ ='\t';2719while((c = *msg++)) {2720if(wasspace &&isspace(c))2721continue;2722 wasspace =isspace(c);2723if(wasspace)2724 c =' ';2725*cp++ = c;2726}2727while(buf < cp &&isspace(cp[-1]))2728 cp--;2729*cp++ ='\n';2730return cp - buf;2731}27322733intlog_ref_setup(const char*refname,char*logfile,int bufsize)2734{2735int logfd, oflags = O_APPEND | O_WRONLY;27362737git_snpath(logfile, bufsize,"logs/%s", refname);2738if(log_all_ref_updates &&2739(starts_with(refname,"refs/heads/") ||2740starts_with(refname,"refs/remotes/") ||2741starts_with(refname,"refs/notes/") ||2742!strcmp(refname,"HEAD"))) {2743if(safe_create_leading_directories(logfile) <0)2744returnerror("unable to create directory for%s",2745 logfile);2746 oflags |= O_CREAT;2747}27482749 logfd =open(logfile, oflags,0666);2750if(logfd <0) {2751if(!(oflags & O_CREAT) && errno == ENOENT)2752return0;27532754if((oflags & O_CREAT) && errno == EISDIR) {2755if(remove_empty_directories(logfile)) {2756returnerror("There are still logs under '%s'",2757 logfile);2758}2759 logfd =open(logfile, oflags,0666);2760}27612762if(logfd <0)2763returnerror("Unable to append to%s:%s",2764 logfile,strerror(errno));2765}27662767adjust_shared_perm(logfile);2768close(logfd);2769return0;2770}27712772static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2773const unsigned char*new_sha1,const char*msg)2774{2775int logfd, result, written, oflags = O_APPEND | O_WRONLY;2776unsigned maxlen, len;2777int msglen;2778char log_file[PATH_MAX];2779char*logrec;2780const char*committer;27812782if(log_all_ref_updates <0)2783 log_all_ref_updates = !is_bare_repository();27842785 result =log_ref_setup(refname, log_file,sizeof(log_file));2786if(result)2787return result;27882789 logfd =open(log_file, oflags);2790if(logfd <0)2791return0;2792 msglen = msg ?strlen(msg) :0;2793 committer =git_committer_info(0);2794 maxlen =strlen(committer) + msglen +100;2795 logrec =xmalloc(maxlen);2796 len =sprintf(logrec,"%s %s %s\n",2797sha1_to_hex(old_sha1),2798sha1_to_hex(new_sha1),2799 committer);2800if(msglen)2801 len +=copy_msg(logrec + len -1, msg) -1;2802 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;2803free(logrec);2804if(close(logfd) !=0|| written != len)2805returnerror("Unable to append to%s", log_file);2806return0;2807}28082809static intis_branch(const char*refname)2810{2811return!strcmp(refname,"HEAD") ||starts_with(refname,"refs/heads/");2812}28132814intwrite_ref_sha1(struct ref_lock *lock,2815const unsigned char*sha1,const char*logmsg)2816{2817static char term ='\n';2818struct object *o;28192820if(!lock)2821return-1;2822if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2823unlock_ref(lock);2824return0;2825}2826 o =parse_object(sha1);2827if(!o) {2828error("Trying to write ref%swith nonexistent object%s",2829 lock->ref_name,sha1_to_hex(sha1));2830unlock_ref(lock);2831return-1;2832}2833if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2834error("Trying to write non-commit object%sto branch%s",2835sha1_to_hex(sha1), lock->ref_name);2836unlock_ref(lock);2837return-1;2838}2839if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||2840write_in_full(lock->lock_fd, &term,1) !=12841||close_ref(lock) <0) {2842error("Couldn't write%s", lock->lk->filename);2843unlock_ref(lock);2844return-1;2845}2846clear_loose_ref_cache(&ref_cache);2847if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||2848(strcmp(lock->ref_name, lock->orig_ref_name) &&2849log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {2850unlock_ref(lock);2851return-1;2852}2853if(strcmp(lock->orig_ref_name,"HEAD") !=0) {2854/*2855 * Special hack: If a branch is updated directly and HEAD2856 * points to it (may happen on the remote side of a push2857 * for example) then logically the HEAD reflog should be2858 * updated too.2859 * A generic solution implies reverse symref information,2860 * but finding all symrefs pointing to the given branch2861 * would be rather costly for this rare event (the direct2862 * update of a branch) to be worth it. So let's cheat and2863 * check with HEAD only which should cover 99% of all usage2864 * scenarios (even 100% of the default ones).2865 */2866unsigned char head_sha1[20];2867int head_flag;2868const char*head_ref;2869 head_ref =resolve_ref_unsafe("HEAD", head_sha1,1, &head_flag);2870if(head_ref && (head_flag & REF_ISSYMREF) &&2871!strcmp(head_ref, lock->ref_name))2872log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);2873}2874if(commit_ref(lock)) {2875error("Couldn't set%s", lock->ref_name);2876unlock_ref(lock);2877return-1;2878}2879unlock_ref(lock);2880return0;2881}28822883intcreate_symref(const char*ref_target,const char*refs_heads_master,2884const char*logmsg)2885{2886const char*lockpath;2887char ref[1000];2888int fd, len, written;2889char*git_HEAD =git_pathdup("%s", ref_target);2890unsigned char old_sha1[20], new_sha1[20];28912892if(logmsg &&read_ref(ref_target, old_sha1))2893hashclr(old_sha1);28942895if(safe_create_leading_directories(git_HEAD) <0)2896returnerror("unable to create directory for%s", git_HEAD);28972898#ifndef NO_SYMLINK_HEAD2899if(prefer_symlink_refs) {2900unlink(git_HEAD);2901if(!symlink(refs_heads_master, git_HEAD))2902goto done;2903fprintf(stderr,"no symlink - falling back to symbolic ref\n");2904}2905#endif29062907 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);2908if(sizeof(ref) <= len) {2909error("refname too long:%s", refs_heads_master);2910goto error_free_return;2911}2912 lockpath =mkpath("%s.lock", git_HEAD);2913 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);2914if(fd <0) {2915error("Unable to open%sfor writing", lockpath);2916goto error_free_return;2917}2918 written =write_in_full(fd, ref, len);2919if(close(fd) !=0|| written != len) {2920error("Unable to write to%s", lockpath);2921goto error_unlink_return;2922}2923if(rename(lockpath, git_HEAD) <0) {2924error("Unable to create%s", git_HEAD);2925goto error_unlink_return;2926}2927if(adjust_shared_perm(git_HEAD)) {2928error("Unable to fix permissions on%s", lockpath);2929 error_unlink_return:2930unlink_or_warn(lockpath);2931 error_free_return:2932free(git_HEAD);2933return-1;2934}29352936#ifndef NO_SYMLINK_HEAD2937 done:2938#endif2939if(logmsg && !read_ref(refs_heads_master, new_sha1))2940log_ref_write(ref_target, old_sha1, new_sha1, logmsg);29412942free(git_HEAD);2943return0;2944}29452946struct read_ref_at_cb {2947const char*refname;2948unsigned long at_time;2949int cnt;2950int reccnt;2951unsigned char*sha1;2952int found_it;29532954unsigned char osha1[20];2955unsigned char nsha1[20];2956int tz;2957unsigned long date;2958char**msg;2959unsigned long*cutoff_time;2960int*cutoff_tz;2961int*cutoff_cnt;2962};29632964static intread_ref_at_ent(unsigned char*osha1,unsigned char*nsha1,2965const char*email,unsigned long timestamp,int tz,2966const char*message,void*cb_data)2967{2968struct read_ref_at_cb *cb = cb_data;29692970 cb->reccnt++;2971 cb->tz = tz;2972 cb->date = timestamp;29732974if(timestamp <= cb->at_time || cb->cnt ==0) {2975if(cb->msg)2976*cb->msg =xstrdup(message);2977if(cb->cutoff_time)2978*cb->cutoff_time = timestamp;2979if(cb->cutoff_tz)2980*cb->cutoff_tz = tz;2981if(cb->cutoff_cnt)2982*cb->cutoff_cnt = cb->reccnt -1;2983/*2984 * we have not yet updated cb->[n|o]sha1 so they still2985 * hold the values for the previous record.2986 */2987if(!is_null_sha1(cb->osha1)) {2988hashcpy(cb->sha1, nsha1);2989if(hashcmp(cb->osha1, nsha1))2990warning("Log for ref%shas gap after%s.",2991 cb->refname,show_date(cb->date, cb->tz, DATE_RFC2822));2992}2993else if(cb->date == cb->at_time)2994hashcpy(cb->sha1, nsha1);2995else if(hashcmp(nsha1, cb->sha1))2996warning("Log for ref%sunexpectedly ended on%s.",2997 cb->refname,show_date(cb->date, cb->tz,2998 DATE_RFC2822));2999hashcpy(cb->osha1, osha1);3000hashcpy(cb->nsha1, nsha1);3001 cb->found_it =1;3002return1;3003}3004hashcpy(cb->osha1, osha1);3005hashcpy(cb->nsha1, nsha1);3006if(cb->cnt >0)3007 cb->cnt--;3008return0;3009}30103011static intread_ref_at_ent_oldest(unsigned char*osha1,unsigned char*nsha1,3012const char*email,unsigned long timestamp,3013int tz,const char*message,void*cb_data)3014{3015struct read_ref_at_cb *cb = cb_data;30163017if(cb->msg)3018*cb->msg =xstrdup(message);3019if(cb->cutoff_time)3020*cb->cutoff_time = timestamp;3021if(cb->cutoff_tz)3022*cb->cutoff_tz = tz;3023if(cb->cutoff_cnt)3024*cb->cutoff_cnt = cb->reccnt;3025hashcpy(cb->sha1, osha1);3026if(is_null_sha1(cb->sha1))3027hashcpy(cb->sha1, nsha1);3028/* We just want the first entry */3029return1;3030}30313032intread_ref_at(const char*refname,unsigned long at_time,int cnt,3033unsigned char*sha1,char**msg,3034unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)3035{3036struct read_ref_at_cb cb;30373038memset(&cb,0,sizeof(cb));3039 cb.refname = refname;3040 cb.at_time = at_time;3041 cb.cnt = cnt;3042 cb.msg = msg;3043 cb.cutoff_time = cutoff_time;3044 cb.cutoff_tz = cutoff_tz;3045 cb.cutoff_cnt = cutoff_cnt;3046 cb.sha1 = sha1;30473048for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);30493050if(!cb.reccnt)3051die("Log for%sis empty.", refname);3052if(cb.found_it)3053return0;30543055for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);30563057return1;3058}30593060intreflog_exists(const char*refname)3061{3062struct stat st;30633064return!lstat(git_path("logs/%s", refname), &st) &&3065S_ISREG(st.st_mode);3066}30673068intdelete_reflog(const char*refname)3069{3070returnremove_path(git_path("logs/%s", refname));3071}30723073static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3074{3075unsigned char osha1[20], nsha1[20];3076char*email_end, *message;3077unsigned long timestamp;3078int tz;30793080/* old SP new SP name <email> SP time TAB msg LF */3081if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3082get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3083get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3084!(email_end =strchr(sb->buf +82,'>')) ||3085 email_end[1] !=' '||3086!(timestamp =strtoul(email_end +2, &message,10)) ||3087!message || message[0] !=' '||3088(message[1] !='+'&& message[1] !='-') ||3089!isdigit(message[2]) || !isdigit(message[3]) ||3090!isdigit(message[4]) || !isdigit(message[5]))3091return0;/* corrupt? */3092 email_end[1] ='\0';3093 tz =strtol(message +1, NULL,10);3094if(message[6] !='\t')3095 message +=6;3096else3097 message +=7;3098returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3099}31003101static char*find_beginning_of_line(char*bob,char*scan)3102{3103while(bob < scan && *(--scan) !='\n')3104;/* keep scanning backwards */3105/*3106 * Return either beginning of the buffer, or LF at the end of3107 * the previous line.3108 */3109return scan;3110}31113112intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3113{3114struct strbuf sb = STRBUF_INIT;3115FILE*logfp;3116long pos;3117int ret =0, at_tail =1;31183119 logfp =fopen(git_path("logs/%s", refname),"r");3120if(!logfp)3121return-1;31223123/* Jump to the end */3124if(fseek(logfp,0, SEEK_END) <0)3125returnerror("cannot seek back reflog for%s:%s",3126 refname,strerror(errno));3127 pos =ftell(logfp);3128while(!ret &&0< pos) {3129int cnt;3130size_t nread;3131char buf[BUFSIZ];3132char*endp, *scanp;31333134/* Fill next block from the end */3135 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3136if(fseek(logfp, pos - cnt, SEEK_SET))3137returnerror("cannot seek back reflog for%s:%s",3138 refname,strerror(errno));3139 nread =fread(buf, cnt,1, logfp);3140if(nread !=1)3141returnerror("cannot read%dbytes from reflog for%s:%s",3142 cnt, refname,strerror(errno));3143 pos -= cnt;31443145 scanp = endp = buf + cnt;3146if(at_tail && scanp[-1] =='\n')3147/* Looking at the final LF at the end of the file */3148 scanp--;3149 at_tail =0;31503151while(buf < scanp) {3152/*3153 * terminating LF of the previous line, or the beginning3154 * of the buffer.3155 */3156char*bp;31573158 bp =find_beginning_of_line(buf, scanp);31593160if(*bp !='\n') {3161strbuf_splice(&sb,0,0, buf, endp - buf);3162if(pos)3163break;/* need to fill another block */3164 scanp = buf -1;/* leave loop */3165}else{3166/*3167 * (bp + 1) thru endp is the beginning of the3168 * current line we have in sb3169 */3170strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3171 scanp = bp;3172 endp = bp +1;3173}3174 ret =show_one_reflog_ent(&sb, fn, cb_data);3175strbuf_reset(&sb);3176if(ret)3177break;3178}31793180}3181if(!ret && sb.len)3182 ret =show_one_reflog_ent(&sb, fn, cb_data);31833184fclose(logfp);3185strbuf_release(&sb);3186return ret;3187}31883189intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3190{3191FILE*logfp;3192struct strbuf sb = STRBUF_INIT;3193int ret =0;31943195 logfp =fopen(git_path("logs/%s", refname),"r");3196if(!logfp)3197return-1;31983199while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3200 ret =show_one_reflog_ent(&sb, fn, cb_data);3201fclose(logfp);3202strbuf_release(&sb);3203return ret;3204}3205/*3206 * Call fn for each reflog in the namespace indicated by name. name3207 * must be empty or end with '/'. Name will be used as a scratch3208 * space, but its contents will be restored before return.3209 */3210static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3211{3212DIR*d =opendir(git_path("logs/%s", name->buf));3213int retval =0;3214struct dirent *de;3215int oldlen = name->len;32163217if(!d)3218return name->len ? errno :0;32193220while((de =readdir(d)) != NULL) {3221struct stat st;32223223if(de->d_name[0] =='.')3224continue;3225if(has_extension(de->d_name,".lock"))3226continue;3227strbuf_addstr(name, de->d_name);3228if(stat(git_path("logs/%s", name->buf), &st) <0) {3229;/* silently ignore */3230}else{3231if(S_ISDIR(st.st_mode)) {3232strbuf_addch(name,'/');3233 retval =do_for_each_reflog(name, fn, cb_data);3234}else{3235unsigned char sha1[20];3236if(read_ref_full(name->buf, sha1,0, NULL))3237 retval =error("bad ref for%s", name->buf);3238else3239 retval =fn(name->buf, sha1,0, cb_data);3240}3241if(retval)3242break;3243}3244strbuf_setlen(name, oldlen);3245}3246closedir(d);3247return retval;3248}32493250intfor_each_reflog(each_ref_fn fn,void*cb_data)3251{3252int retval;3253struct strbuf name;3254strbuf_init(&name, PATH_MAX);3255 retval =do_for_each_reflog(&name, fn, cb_data);3256strbuf_release(&name);3257return retval;3258}32593260static struct ref_lock *update_ref_lock(const char*refname,3261const unsigned char*oldval,3262int flags,int*type_p,3263enum action_on_err onerr)3264{3265struct ref_lock *lock;3266 lock =lock_any_ref_for_update(refname, oldval, flags, type_p);3267if(!lock) {3268const char*str ="Cannot lock the ref '%s'.";3269switch(onerr) {3270case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3271case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3272case UPDATE_REFS_QUIET_ON_ERR:break;3273}3274}3275return lock;3276}32773278static intupdate_ref_write(const char*action,const char*refname,3279const unsigned char*sha1,struct ref_lock *lock,3280enum action_on_err onerr)3281{3282if(write_ref_sha1(lock, sha1, action) <0) {3283const char*str ="Cannot update the ref '%s'.";3284switch(onerr) {3285case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3286case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3287case UPDATE_REFS_QUIET_ON_ERR:break;3288}3289return1;3290}3291return0;3292}32933294/**3295 * Information needed for a single ref update. Set new_sha1 to the3296 * new value or to zero to delete the ref. To check the old value3297 * while locking the ref, set have_old to 1 and set old_sha1 to the3298 * value or to zero to ensure the ref does not exist before update.3299 */3300struct ref_update {3301unsigned char new_sha1[20];3302unsigned char old_sha1[20];3303int flags;/* REF_NODEREF? */3304int have_old;/* 1 if old_sha1 is valid, 0 otherwise */3305struct ref_lock *lock;3306int type;3307const char refname[FLEX_ARRAY];3308};33093310/*3311 * Data structure for holding a reference transaction, which can3312 * consist of checks and updates to multiple references, carried out3313 * as atomically as possible. This structure is opaque to callers.3314 */3315struct ref_transaction {3316struct ref_update **updates;3317size_t alloc;3318size_t nr;3319};33203321struct ref_transaction *ref_transaction_begin(void)3322{3323returnxcalloc(1,sizeof(struct ref_transaction));3324}33253326static voidref_transaction_free(struct ref_transaction *transaction)3327{3328int i;33293330for(i =0; i < transaction->nr; i++)3331free(transaction->updates[i]);33323333free(transaction->updates);3334free(transaction);3335}33363337voidref_transaction_rollback(struct ref_transaction *transaction)3338{3339ref_transaction_free(transaction);3340}33413342static struct ref_update *add_update(struct ref_transaction *transaction,3343const char*refname)3344{3345size_t len =strlen(refname);3346struct ref_update *update =xcalloc(1,sizeof(*update) + len +1);33473348strcpy((char*)update->refname, refname);3349ALLOC_GROW(transaction->updates, transaction->nr +1, transaction->alloc);3350 transaction->updates[transaction->nr++] = update;3351return update;3352}33533354voidref_transaction_update(struct ref_transaction *transaction,3355const char*refname,3356unsigned char*new_sha1,unsigned char*old_sha1,3357int flags,int have_old)3358{3359struct ref_update *update =add_update(transaction, refname);33603361hashcpy(update->new_sha1, new_sha1);3362 update->flags = flags;3363 update->have_old = have_old;3364if(have_old)3365hashcpy(update->old_sha1, old_sha1);3366}33673368voidref_transaction_create(struct ref_transaction *transaction,3369const char*refname,3370unsigned char*new_sha1,3371int flags)3372{3373struct ref_update *update =add_update(transaction, refname);33743375assert(!is_null_sha1(new_sha1));3376hashcpy(update->new_sha1, new_sha1);3377hashclr(update->old_sha1);3378 update->flags = flags;3379 update->have_old =1;3380}33813382voidref_transaction_delete(struct ref_transaction *transaction,3383const char*refname,3384unsigned char*old_sha1,3385int flags,int have_old)3386{3387struct ref_update *update =add_update(transaction, refname);33883389 update->flags = flags;3390 update->have_old = have_old;3391if(have_old) {3392assert(!is_null_sha1(old_sha1));3393hashcpy(update->old_sha1, old_sha1);3394}3395}33963397intupdate_ref(const char*action,const char*refname,3398const unsigned char*sha1,const unsigned char*oldval,3399int flags,enum action_on_err onerr)3400{3401struct ref_lock *lock;3402 lock =update_ref_lock(refname, oldval, flags, NULL, onerr);3403if(!lock)3404return1;3405returnupdate_ref_write(action, refname, sha1, lock, onerr);3406}34073408static intref_update_compare(const void*r1,const void*r2)3409{3410const struct ref_update *const*u1 = r1;3411const struct ref_update *const*u2 = r2;3412returnstrcmp((*u1)->refname, (*u2)->refname);3413}34143415static intref_update_reject_duplicates(struct ref_update **updates,int n,3416enum action_on_err onerr)3417{3418int i;3419for(i =1; i < n; i++)3420if(!strcmp(updates[i -1]->refname, updates[i]->refname)) {3421const char*str =3422"Multiple updates for ref '%s' not allowed.";3423switch(onerr) {3424case UPDATE_REFS_MSG_ON_ERR:3425error(str, updates[i]->refname);break;3426case UPDATE_REFS_DIE_ON_ERR:3427die(str, updates[i]->refname);break;3428case UPDATE_REFS_QUIET_ON_ERR:3429break;3430}3431return1;3432}3433return0;3434}34353436intref_transaction_commit(struct ref_transaction *transaction,3437const char*msg,enum action_on_err onerr)3438{3439int ret =0, delnum =0, i;3440const char**delnames;3441int n = transaction->nr;3442struct ref_update **updates = transaction->updates;34433444if(!n)3445return0;34463447/* Allocate work space */3448 delnames =xmalloc(sizeof(*delnames) * n);34493450/* Copy, sort, and reject duplicate refs */3451qsort(updates, n,sizeof(*updates), ref_update_compare);3452 ret =ref_update_reject_duplicates(updates, n, onerr);3453if(ret)3454goto cleanup;34553456/* Acquire all locks while verifying old values */3457for(i =0; i < n; i++) {3458struct ref_update *update = updates[i];34593460 update->lock =update_ref_lock(update->refname,3461(update->have_old ?3462 update->old_sha1 : NULL),3463 update->flags,3464&update->type, onerr);3465if(!update->lock) {3466 ret =1;3467goto cleanup;3468}3469}34703471/* Perform updates first so live commits remain referenced */3472for(i =0; i < n; i++) {3473struct ref_update *update = updates[i];34743475if(!is_null_sha1(update->new_sha1)) {3476 ret =update_ref_write(msg,3477 update->refname,3478 update->new_sha1,3479 update->lock, onerr);3480 update->lock = NULL;/* freed by update_ref_write */3481if(ret)3482goto cleanup;3483}3484}34853486/* Perform deletes now that updates are safely completed */3487for(i =0; i < n; i++) {3488struct ref_update *update = updates[i];34893490if(update->lock) {3491 delnames[delnum++] = update->lock->ref_name;3492 ret |=delete_ref_loose(update->lock, update->type);3493}3494}34953496 ret |=repack_without_refs(delnames, delnum);3497for(i =0; i < delnum; i++)3498unlink_or_warn(git_path("logs/%s", delnames[i]));3499clear_loose_ref_cache(&ref_cache);35003501cleanup:3502for(i =0; i < n; i++)3503if(updates[i]->lock)3504unlock_ref(updates[i]->lock);3505free(delnames);3506ref_transaction_free(transaction);3507return ret;3508}35093510char*shorten_unambiguous_ref(const char*refname,int strict)3511{3512int i;3513static char**scanf_fmts;3514static int nr_rules;3515char*short_name;35163517if(!nr_rules) {3518/*3519 * Pre-generate scanf formats from ref_rev_parse_rules[].3520 * Generate a format suitable for scanf from a3521 * ref_rev_parse_rules rule by interpolating "%s" at the3522 * location of the "%.*s".3523 */3524size_t total_len =0;3525size_t offset =0;35263527/* the rule list is NULL terminated, count them first */3528for(nr_rules =0; ref_rev_parse_rules[nr_rules]; nr_rules++)3529/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3530 total_len +=strlen(ref_rev_parse_rules[nr_rules]) -2+1;35313532 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);35333534 offset =0;3535for(i =0; i < nr_rules; i++) {3536assert(offset < total_len);3537 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules] + offset;3538 offset +=snprintf(scanf_fmts[i], total_len - offset,3539 ref_rev_parse_rules[i],2,"%s") +1;3540}3541}35423543/* bail out if there are no rules */3544if(!nr_rules)3545returnxstrdup(refname);35463547/* buffer for scanf result, at most refname must fit */3548 short_name =xstrdup(refname);35493550/* skip first rule, it will always match */3551for(i = nr_rules -1; i >0; --i) {3552int j;3553int rules_to_fail = i;3554int short_name_len;35553556if(1!=sscanf(refname, scanf_fmts[i], short_name))3557continue;35583559 short_name_len =strlen(short_name);35603561/*3562 * in strict mode, all (except the matched one) rules3563 * must fail to resolve to a valid non-ambiguous ref3564 */3565if(strict)3566 rules_to_fail = nr_rules;35673568/*3569 * check if the short name resolves to a valid ref,3570 * but use only rules prior to the matched one3571 */3572for(j =0; j < rules_to_fail; j++) {3573const char*rule = ref_rev_parse_rules[j];3574char refname[PATH_MAX];35753576/* skip matched rule */3577if(i == j)3578continue;35793580/*3581 * the short name is ambiguous, if it resolves3582 * (with this previous rule) to a valid ref3583 * read_ref() returns 0 on success3584 */3585mksnpath(refname,sizeof(refname),3586 rule, short_name_len, short_name);3587if(ref_exists(refname))3588break;3589}35903591/*3592 * short name is non-ambiguous if all previous rules3593 * haven't resolved to a valid ref3594 */3595if(j == rules_to_fail)3596return short_name;3597}35983599free(short_name);3600returnxstrdup(refname);3601}36023603static struct string_list *hide_refs;36043605intparse_hide_refs_config(const char*var,const char*value,const char*section)3606{3607if(!strcmp("transfer.hiderefs", var) ||3608/* NEEDSWORK: use parse_config_key() once both are merged */3609(starts_with(var, section) && var[strlen(section)] =='.'&&3610!strcmp(var +strlen(section),".hiderefs"))) {3611char*ref;3612int len;36133614if(!value)3615returnconfig_error_nonbool(var);3616 ref =xstrdup(value);3617 len =strlen(ref);3618while(len && ref[len -1] =='/')3619 ref[--len] ='\0';3620if(!hide_refs) {3621 hide_refs =xcalloc(1,sizeof(*hide_refs));3622 hide_refs->strdup_strings =1;3623}3624string_list_append(hide_refs, ref);3625}3626return0;3627}36283629intref_is_hidden(const char*refname)3630{3631struct string_list_item *item;36323633if(!hide_refs)3634return0;3635for_each_string_list_item(item, hide_refs) {3636int len;3637if(!starts_with(refname, item->string))3638continue;3639 len =strlen(item->string);3640if(!refname[len] || refname[len] =='/')3641return1;3642}3643return0;3644}