1#include"cache.h" 2#include"refs.h" 3#include"object.h" 4#include"tag.h" 5#include"dir.h" 6 7/* 8 * Make sure "ref" is something reasonable to have under ".git/refs/"; 9 * We do not like it if: 10 * 11 * - any path component of it begins with ".", or 12 * - it has double dots "..", or 13 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 14 * - it ends with a "/". 15 * - it ends with ".lock" 16 * - it contains a "\" (backslash) 17 */ 18 19/* Return true iff ch is not allowed in reference names. */ 20staticinlineintbad_ref_char(int ch) 21{ 22if(((unsigned) ch) <=' '|| ch ==0x7f|| 23 ch =='~'|| ch =='^'|| ch ==':'|| ch =='\\') 24return1; 25/* 2.13 Pattern Matching Notation */ 26if(ch =='*'|| ch =='?'|| ch =='[')/* Unsupported */ 27return1; 28return0; 29} 30 31/* 32 * Try to read one refname component from the front of refname. Return 33 * the length of the component found, or -1 if the component is not 34 * legal. 35 */ 36static intcheck_refname_component(const char*refname,int flags) 37{ 38const char*cp; 39char last ='\0'; 40 41for(cp = refname; ; cp++) { 42char ch = *cp; 43if(ch =='\0'|| ch =='/') 44break; 45if(bad_ref_char(ch)) 46return-1;/* Illegal character in refname. */ 47if(last =='.'&& ch =='.') 48return-1;/* Refname contains "..". */ 49if(last =='@'&& ch =='{') 50return-1;/* Refname contains "@{". */ 51 last = ch; 52} 53if(cp == refname) 54return0;/* Component has zero length. */ 55if(refname[0] =='.') { 56if(!(flags & REFNAME_DOT_COMPONENT)) 57return-1;/* Component starts with '.'. */ 58/* 59 * Even if leading dots are allowed, don't allow "." 60 * as a component (".." is prevented by a rule above). 61 */ 62if(refname[1] =='\0') 63return-1;/* Component equals ".". */ 64} 65if(cp - refname >=5&& !memcmp(cp -5,".lock",5)) 66return-1;/* Refname ends with ".lock". */ 67return cp - refname; 68} 69 70intcheck_refname_format(const char*refname,int flags) 71{ 72int component_len, component_count =0; 73 74while(1) { 75/* We are at the start of a path component. */ 76 component_len =check_refname_component(refname, flags); 77if(component_len <=0) { 78if((flags & REFNAME_REFSPEC_PATTERN) && 79 refname[0] =='*'&& 80(refname[1] =='\0'|| refname[1] =='/')) { 81/* Accept one wildcard as a full refname component. */ 82 flags &= ~REFNAME_REFSPEC_PATTERN; 83 component_len =1; 84}else{ 85return-1; 86} 87} 88 component_count++; 89if(refname[component_len] =='\0') 90break; 91/* Skip to next component. */ 92 refname += component_len +1; 93} 94 95if(refname[component_len -1] =='.') 96return-1;/* Refname ends with '.'. */ 97if(!(flags & REFNAME_ALLOW_ONELEVEL) && component_count <2) 98return-1;/* Refname has only one component. */ 99return0; 100} 101 102struct ref_entry; 103 104/* 105 * Information used (along with the information in ref_entry) to 106 * describe a single cached reference. This data structure only 107 * occurs embedded in a union in struct ref_entry, and only when 108 * (ref_entry->flag & REF_DIR) is zero. 109 */ 110struct ref_value { 111/* 112 * The name of the object to which this reference resolves 113 * (which may be a tag object). If REF_ISBROKEN, this is 114 * null. If REF_ISSYMREF, then this is the name of the object 115 * referred to by the last reference in the symlink chain. 116 */ 117unsigned char sha1[20]; 118 119/* 120 * If REF_KNOWS_PEELED, then this field holds the peeled value 121 * of this reference, or null if the reference is known not to 122 * be peelable. See the documentation for peel_ref() for an 123 * exact definition of "peelable". 124 */ 125unsigned char peeled[20]; 126}; 127 128struct ref_cache; 129 130/* 131 * Information used (along with the information in ref_entry) to 132 * describe a level in the hierarchy of references. This data 133 * structure only occurs embedded in a union in struct ref_entry, and 134 * only when (ref_entry.flag & REF_DIR) is set. In that case, 135 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 136 * in the directory have already been read: 137 * 138 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 139 * or packed references, already read. 140 * 141 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 142 * references that hasn't been read yet (nor has any of its 143 * subdirectories). 144 * 145 * Entries within a directory are stored within a growable array of 146 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 147 * sorted are sorted by their component name in strcmp() order and the 148 * remaining entries are unsorted. 149 * 150 * Loose references are read lazily, one directory at a time. When a 151 * directory of loose references is read, then all of the references 152 * in that directory are stored, and REF_INCOMPLETE stubs are created 153 * for any subdirectories, but the subdirectories themselves are not 154 * read. The reading is triggered by get_ref_dir(). 155 */ 156struct ref_dir { 157int nr, alloc; 158 159/* 160 * Entries with index 0 <= i < sorted are sorted by name. New 161 * entries are appended to the list unsorted, and are sorted 162 * only when required; thus we avoid the need to sort the list 163 * after the addition of every reference. 164 */ 165int sorted; 166 167/* A pointer to the ref_cache that contains this ref_dir. */ 168struct ref_cache *ref_cache; 169 170struct ref_entry **entries; 171}; 172 173/* 174 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 175 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see 176 * refs.h. 177 */ 178 179/* 180 * The field ref_entry->u.value.peeled of this value entry contains 181 * the correct peeled value for the reference, which might be 182 * null_sha1 if the reference is not a tag or if it is broken. 183 */ 184#define REF_KNOWS_PEELED 0x08 185 186/* ref_entry represents a directory of references */ 187#define REF_DIR 0x10 188 189/* 190 * Entry has not yet been read from disk (used only for REF_DIR 191 * entries representing loose references) 192 */ 193#define REF_INCOMPLETE 0x20 194 195/* 196 * A ref_entry represents either a reference or a "subdirectory" of 197 * references. 198 * 199 * Each directory in the reference namespace is represented by a 200 * ref_entry with (flags & REF_DIR) set and containing a subdir member 201 * that holds the entries in that directory that have been read so 202 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 203 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 204 * used for loose reference directories. 205 * 206 * References are represented by a ref_entry with (flags & REF_DIR) 207 * unset and a value member that describes the reference's value. The 208 * flag member is at the ref_entry level, but it is also needed to 209 * interpret the contents of the value field (in other words, a 210 * ref_value object is not very much use without the enclosing 211 * ref_entry). 212 * 213 * Reference names cannot end with slash and directories' names are 214 * always stored with a trailing slash (except for the top-level 215 * directory, which is always denoted by ""). This has two nice 216 * consequences: (1) when the entries in each subdir are sorted 217 * lexicographically by name (as they usually are), the references in 218 * a whole tree can be generated in lexicographic order by traversing 219 * the tree in left-to-right, depth-first order; (2) the names of 220 * references and subdirectories cannot conflict, and therefore the 221 * presence of an empty subdirectory does not block the creation of a 222 * similarly-named reference. (The fact that reference names with the 223 * same leading components can conflict *with each other* is a 224 * separate issue that is regulated by is_refname_available().) 225 * 226 * Please note that the name field contains the fully-qualified 227 * reference (or subdirectory) name. Space could be saved by only 228 * storing the relative names. But that would require the full names 229 * to be generated on the fly when iterating in do_for_each_ref(), and 230 * would break callback functions, who have always been able to assume 231 * that the name strings that they are passed will not be freed during 232 * the iteration. 233 */ 234struct ref_entry { 235unsigned char flag;/* ISSYMREF? ISPACKED? */ 236union{ 237struct ref_value value;/* if not (flags&REF_DIR) */ 238struct ref_dir subdir;/* if (flags&REF_DIR) */ 239} u; 240/* 241 * The full name of the reference (e.g., "refs/heads/master") 242 * or the full name of the directory with a trailing slash 243 * (e.g., "refs/heads/"): 244 */ 245char name[FLEX_ARRAY]; 246}; 247 248static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 249 250static struct ref_dir *get_ref_dir(struct ref_entry *entry) 251{ 252struct ref_dir *dir; 253assert(entry->flag & REF_DIR); 254 dir = &entry->u.subdir; 255if(entry->flag & REF_INCOMPLETE) { 256read_loose_refs(entry->name, dir); 257 entry->flag &= ~REF_INCOMPLETE; 258} 259return dir; 260} 261 262static struct ref_entry *create_ref_entry(const char*refname, 263const unsigned char*sha1,int flag, 264int check_name) 265{ 266int len; 267struct ref_entry *ref; 268 269if(check_name && 270check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) 271die("Reference has invalid format: '%s'", refname); 272 len =strlen(refname) +1; 273 ref =xmalloc(sizeof(struct ref_entry) + len); 274hashcpy(ref->u.value.sha1, sha1); 275hashclr(ref->u.value.peeled); 276memcpy(ref->name, refname, len); 277 ref->flag = flag; 278return ref; 279} 280 281static voidclear_ref_dir(struct ref_dir *dir); 282 283static voidfree_ref_entry(struct ref_entry *entry) 284{ 285if(entry->flag & REF_DIR) { 286/* 287 * Do not use get_ref_dir() here, as that might 288 * trigger the reading of loose refs. 289 */ 290clear_ref_dir(&entry->u.subdir); 291} 292free(entry); 293} 294 295/* 296 * Add a ref_entry to the end of dir (unsorted). Entry is always 297 * stored directly in dir; no recursion into subdirectories is 298 * done. 299 */ 300static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 301{ 302ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 303 dir->entries[dir->nr++] = entry; 304/* optimize for the case that entries are added in order */ 305if(dir->nr ==1|| 306(dir->nr == dir->sorted +1&& 307strcmp(dir->entries[dir->nr -2]->name, 308 dir->entries[dir->nr -1]->name) <0)) 309 dir->sorted = dir->nr; 310} 311 312/* 313 * Clear and free all entries in dir, recursively. 314 */ 315static voidclear_ref_dir(struct ref_dir *dir) 316{ 317int i; 318for(i =0; i < dir->nr; i++) 319free_ref_entry(dir->entries[i]); 320free(dir->entries); 321 dir->sorted = dir->nr = dir->alloc =0; 322 dir->entries = NULL; 323} 324 325/* 326 * Create a struct ref_entry object for the specified dirname. 327 * dirname is the name of the directory with a trailing slash (e.g., 328 * "refs/heads/") or "" for the top-level directory. 329 */ 330static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 331const char*dirname,size_t len, 332int incomplete) 333{ 334struct ref_entry *direntry; 335 direntry =xcalloc(1,sizeof(struct ref_entry) + len +1); 336memcpy(direntry->name, dirname, len); 337 direntry->name[len] ='\0'; 338 direntry->u.subdir.ref_cache = ref_cache; 339 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 340return direntry; 341} 342 343static intref_entry_cmp(const void*a,const void*b) 344{ 345struct ref_entry *one = *(struct ref_entry **)a; 346struct ref_entry *two = *(struct ref_entry **)b; 347returnstrcmp(one->name, two->name); 348} 349 350static voidsort_ref_dir(struct ref_dir *dir); 351 352struct string_slice { 353size_t len; 354const char*str; 355}; 356 357static intref_entry_cmp_sslice(const void*key_,const void*ent_) 358{ 359struct string_slice *key = (struct string_slice *)key_; 360struct ref_entry *ent = *(struct ref_entry **)ent_; 361int entlen =strlen(ent->name); 362int cmplen = key->len < entlen ? key->len : entlen; 363int cmp =memcmp(key->str, ent->name, cmplen); 364if(cmp) 365return cmp; 366return key->len - entlen; 367} 368 369/* 370 * Return the entry with the given refname from the ref_dir 371 * (non-recursively), sorting dir if necessary. Return NULL if no 372 * such entry is found. dir must already be complete. 373 */ 374static struct ref_entry *search_ref_dir(struct ref_dir *dir, 375const char*refname,size_t len) 376{ 377struct ref_entry **r; 378struct string_slice key; 379 380if(refname == NULL || !dir->nr) 381return NULL; 382 383sort_ref_dir(dir); 384 key.len = len; 385 key.str = refname; 386 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 387 ref_entry_cmp_sslice); 388 389if(r == NULL) 390return NULL; 391 392return*r; 393} 394 395/* 396 * Search for a directory entry directly within dir (without 397 * recursing). Sort dir if necessary. subdirname must be a directory 398 * name (i.e., end in '/'). If mkdir is set, then create the 399 * directory if it is missing; otherwise, return NULL if the desired 400 * directory cannot be found. dir must already be complete. 401 */ 402static struct ref_dir *search_for_subdir(struct ref_dir *dir, 403const char*subdirname,size_t len, 404int mkdir) 405{ 406struct ref_entry *entry =search_ref_dir(dir, subdirname, len); 407if(!entry) { 408if(!mkdir) 409return NULL; 410/* 411 * Since dir is complete, the absence of a subdir 412 * means that the subdir really doesn't exist; 413 * therefore, create an empty record for it but mark 414 * the record complete. 415 */ 416 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 417add_entry_to_dir(dir, entry); 418} 419returnget_ref_dir(entry); 420} 421 422/* 423 * If refname is a reference name, find the ref_dir within the dir 424 * tree that should hold refname. If refname is a directory name 425 * (i.e., ends in '/'), then return that ref_dir itself. dir must 426 * represent the top-level directory and must already be complete. 427 * Sort ref_dirs and recurse into subdirectories as necessary. If 428 * mkdir is set, then create any missing directories; otherwise, 429 * return NULL if the desired directory cannot be found. 430 */ 431static struct ref_dir *find_containing_dir(struct ref_dir *dir, 432const char*refname,int mkdir) 433{ 434const char*slash; 435for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 436size_t dirnamelen = slash - refname +1; 437struct ref_dir *subdir; 438 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 439if(!subdir) { 440 dir = NULL; 441break; 442} 443 dir = subdir; 444} 445 446return dir; 447} 448 449/* 450 * Find the value entry with the given name in dir, sorting ref_dirs 451 * and recursing into subdirectories as necessary. If the name is not 452 * found or it corresponds to a directory entry, return NULL. 453 */ 454static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 455{ 456struct ref_entry *entry; 457 dir =find_containing_dir(dir, refname,0); 458if(!dir) 459return NULL; 460 entry =search_ref_dir(dir, refname,strlen(refname)); 461return(entry && !(entry->flag & REF_DIR)) ? entry : NULL; 462} 463 464/* 465 * Add a ref_entry to the ref_dir (unsorted), recursing into 466 * subdirectories as necessary. dir must represent the top-level 467 * directory. Return 0 on success. 468 */ 469static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 470{ 471 dir =find_containing_dir(dir, ref->name,1); 472if(!dir) 473return-1; 474add_entry_to_dir(dir, ref); 475return0; 476} 477 478/* 479 * Emit a warning and return true iff ref1 and ref2 have the same name 480 * and the same sha1. Die if they have the same name but different 481 * sha1s. 482 */ 483static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 484{ 485if(strcmp(ref1->name, ref2->name)) 486return0; 487 488/* Duplicate name; make sure that they don't conflict: */ 489 490if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 491/* This is impossible by construction */ 492die("Reference directory conflict:%s", ref1->name); 493 494if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 495die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 496 497warning("Duplicated ref:%s", ref1->name); 498return1; 499} 500 501/* 502 * Sort the entries in dir non-recursively (if they are not already 503 * sorted) and remove any duplicate entries. 504 */ 505static voidsort_ref_dir(struct ref_dir *dir) 506{ 507int i, j; 508struct ref_entry *last = NULL; 509 510/* 511 * This check also prevents passing a zero-length array to qsort(), 512 * which is a problem on some platforms. 513 */ 514if(dir->sorted == dir->nr) 515return; 516 517qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 518 519/* Remove any duplicates: */ 520for(i =0, j =0; j < dir->nr; j++) { 521struct ref_entry *entry = dir->entries[j]; 522if(last &&is_dup_ref(last, entry)) 523free_ref_entry(entry); 524else 525 last = dir->entries[i++] = entry; 526} 527 dir->sorted = dir->nr = i; 528} 529 530/* Include broken references in a do_for_each_ref*() iteration: */ 531#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 532 533/* 534 * Return true iff the reference described by entry can be resolved to 535 * an object in the database. Emit a warning if the referred-to 536 * object does not exist. 537 */ 538static intref_resolves_to_object(struct ref_entry *entry) 539{ 540if(entry->flag & REF_ISBROKEN) 541return0; 542if(!has_sha1_file(entry->u.value.sha1)) { 543error("%sdoes not point to a valid object!", entry->name); 544return0; 545} 546return1; 547} 548 549/* 550 * current_ref is a performance hack: when iterating over references 551 * using the for_each_ref*() functions, current_ref is set to the 552 * current reference's entry before calling the callback function. If 553 * the callback function calls peel_ref(), then peel_ref() first 554 * checks whether the reference to be peeled is the current reference 555 * (it usually is) and if so, returns that reference's peeled version 556 * if it is available. This avoids a refname lookup in a common case. 557 */ 558static struct ref_entry *current_ref; 559 560typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 561 562struct ref_entry_cb { 563const char*base; 564int trim; 565int flags; 566 each_ref_fn *fn; 567void*cb_data; 568}; 569 570/* 571 * Handle one reference in a do_for_each_ref*()-style iteration, 572 * calling an each_ref_fn for each entry. 573 */ 574static intdo_one_ref(struct ref_entry *entry,void*cb_data) 575{ 576struct ref_entry_cb *data = cb_data; 577int retval; 578if(prefixcmp(entry->name, data->base)) 579return0; 580 581if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 582!ref_resolves_to_object(entry)) 583return0; 584 585 current_ref = entry; 586 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 587 entry->flag, data->cb_data); 588 current_ref = NULL; 589return retval; 590} 591 592/* 593 * Call fn for each reference in dir that has index in the range 594 * offset <= index < dir->nr. Recurse into subdirectories that are in 595 * that index range, sorting them before iterating. This function 596 * does not sort dir itself; it should be sorted beforehand. fn is 597 * called for all references, including broken ones. 598 */ 599static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 600 each_ref_entry_fn fn,void*cb_data) 601{ 602int i; 603assert(dir->sorted == dir->nr); 604for(i = offset; i < dir->nr; i++) { 605struct ref_entry *entry = dir->entries[i]; 606int retval; 607if(entry->flag & REF_DIR) { 608struct ref_dir *subdir =get_ref_dir(entry); 609sort_ref_dir(subdir); 610 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 611}else{ 612 retval =fn(entry, cb_data); 613} 614if(retval) 615return retval; 616} 617return0; 618} 619 620/* 621 * Call fn for each reference in the union of dir1 and dir2, in order 622 * by refname. Recurse into subdirectories. If a value entry appears 623 * in both dir1 and dir2, then only process the version that is in 624 * dir2. The input dirs must already be sorted, but subdirs will be 625 * sorted as needed. fn is called for all references, including 626 * broken ones. 627 */ 628static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 629struct ref_dir *dir2, 630 each_ref_entry_fn fn,void*cb_data) 631{ 632int retval; 633int i1 =0, i2 =0; 634 635assert(dir1->sorted == dir1->nr); 636assert(dir2->sorted == dir2->nr); 637while(1) { 638struct ref_entry *e1, *e2; 639int cmp; 640if(i1 == dir1->nr) { 641returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 642} 643if(i2 == dir2->nr) { 644returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 645} 646 e1 = dir1->entries[i1]; 647 e2 = dir2->entries[i2]; 648 cmp =strcmp(e1->name, e2->name); 649if(cmp ==0) { 650if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 651/* Both are directories; descend them in parallel. */ 652struct ref_dir *subdir1 =get_ref_dir(e1); 653struct ref_dir *subdir2 =get_ref_dir(e2); 654sort_ref_dir(subdir1); 655sort_ref_dir(subdir2); 656 retval =do_for_each_entry_in_dirs( 657 subdir1, subdir2, fn, cb_data); 658 i1++; 659 i2++; 660}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 661/* Both are references; ignore the one from dir1. */ 662 retval =fn(e2, cb_data); 663 i1++; 664 i2++; 665}else{ 666die("conflict between reference and directory:%s", 667 e1->name); 668} 669}else{ 670struct ref_entry *e; 671if(cmp <0) { 672 e = e1; 673 i1++; 674}else{ 675 e = e2; 676 i2++; 677} 678if(e->flag & REF_DIR) { 679struct ref_dir *subdir =get_ref_dir(e); 680sort_ref_dir(subdir); 681 retval =do_for_each_entry_in_dir( 682 subdir,0, fn, cb_data); 683}else{ 684 retval =fn(e, cb_data); 685} 686} 687if(retval) 688return retval; 689} 690} 691 692/* 693 * Return true iff refname1 and refname2 conflict with each other. 694 * Two reference names conflict if one of them exactly matches the 695 * leading components of the other; e.g., "foo/bar" conflicts with 696 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 697 * "foo/barbados". 698 */ 699static intnames_conflict(const char*refname1,const char*refname2) 700{ 701for(; *refname1 && *refname1 == *refname2; refname1++, refname2++) 702; 703return(*refname1 =='\0'&& *refname2 =='/') 704|| (*refname1 =='/'&& *refname2 =='\0'); 705} 706 707struct name_conflict_cb { 708const char*refname; 709const char*oldrefname; 710const char*conflicting_refname; 711}; 712 713static intname_conflict_fn(struct ref_entry *entry,void*cb_data) 714{ 715struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data; 716if(data->oldrefname && !strcmp(data->oldrefname, entry->name)) 717return0; 718if(names_conflict(data->refname, entry->name)) { 719 data->conflicting_refname = entry->name; 720return1; 721} 722return0; 723} 724 725/* 726 * Return true iff a reference named refname could be created without 727 * conflicting with the name of an existing reference in dir. If 728 * oldrefname is non-NULL, ignore potential conflicts with oldrefname 729 * (e.g., because oldrefname is scheduled for deletion in the same 730 * operation). 731 */ 732static intis_refname_available(const char*refname,const char*oldrefname, 733struct ref_dir *dir) 734{ 735struct name_conflict_cb data; 736 data.refname = refname; 737 data.oldrefname = oldrefname; 738 data.conflicting_refname = NULL; 739 740sort_ref_dir(dir); 741if(do_for_each_entry_in_dir(dir,0, name_conflict_fn, &data)) { 742error("'%s' exists; cannot create '%s'", 743 data.conflicting_refname, refname); 744return0; 745} 746return1; 747} 748 749/* 750 * Future: need to be in "struct repository" 751 * when doing a full libification. 752 */ 753static struct ref_cache { 754struct ref_cache *next; 755struct ref_entry *loose; 756struct ref_entry *packed; 757/* The submodule name, or "" for the main repo. */ 758char name[FLEX_ARRAY]; 759} *ref_cache; 760 761static voidclear_packed_ref_cache(struct ref_cache *refs) 762{ 763if(refs->packed) { 764free_ref_entry(refs->packed); 765 refs->packed = NULL; 766} 767} 768 769static voidclear_loose_ref_cache(struct ref_cache *refs) 770{ 771if(refs->loose) { 772free_ref_entry(refs->loose); 773 refs->loose = NULL; 774} 775} 776 777static struct ref_cache *create_ref_cache(const char*submodule) 778{ 779int len; 780struct ref_cache *refs; 781if(!submodule) 782 submodule =""; 783 len =strlen(submodule) +1; 784 refs =xcalloc(1,sizeof(struct ref_cache) + len); 785memcpy(refs->name, submodule, len); 786return refs; 787} 788 789/* 790 * Return a pointer to a ref_cache for the specified submodule. For 791 * the main repository, use submodule==NULL. The returned structure 792 * will be allocated and initialized but not necessarily populated; it 793 * should not be freed. 794 */ 795static struct ref_cache *get_ref_cache(const char*submodule) 796{ 797struct ref_cache *refs = ref_cache; 798if(!submodule) 799 submodule =""; 800while(refs) { 801if(!strcmp(submodule, refs->name)) 802return refs; 803 refs = refs->next; 804} 805 806 refs =create_ref_cache(submodule); 807 refs->next = ref_cache; 808 ref_cache = refs; 809return refs; 810} 811 812voidinvalidate_ref_cache(const char*submodule) 813{ 814struct ref_cache *refs =get_ref_cache(submodule); 815clear_packed_ref_cache(refs); 816clear_loose_ref_cache(refs); 817} 818 819/* The length of a peeled reference line in packed-refs, including EOL: */ 820#define PEELED_LINE_LENGTH 42 821 822/* 823 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 824 * Return a pointer to the refname within the line (null-terminated), 825 * or NULL if there was a problem. 826 */ 827static const char*parse_ref_line(char*line,unsigned char*sha1) 828{ 829/* 830 * 42: the answer to everything. 831 * 832 * In this case, it happens to be the answer to 833 * 40 (length of sha1 hex representation) 834 * +1 (space in between hex and name) 835 * +1 (newline at the end of the line) 836 */ 837int len =strlen(line) -42; 838 839if(len <=0) 840return NULL; 841if(get_sha1_hex(line, sha1) <0) 842return NULL; 843if(!isspace(line[40])) 844return NULL; 845 line +=41; 846if(isspace(*line)) 847return NULL; 848if(line[len] !='\n') 849return NULL; 850 line[len] =0; 851 852return line; 853} 854 855/* 856 * Read f, which is a packed-refs file, into dir. 857 * 858 * A comment line of the form "# pack-refs with: " may contain zero or 859 * more traits. We interpret the traits as follows: 860 * 861 * No traits: 862 * 863 * Probably no references are peeled. But if the file contains a 864 * peeled value for a reference, we will use it. 865 * 866 * peeled: 867 * 868 * References under "refs/tags/", if they *can* be peeled, *are* 869 * peeled in this file. References outside of "refs/tags/" are 870 * probably not peeled even if they could have been, but if we find 871 * a peeled value for such a reference we will use it. 872 * 873 * fully-peeled: 874 * 875 * All references in the file that can be peeled are peeled. 876 * Inversely (and this is more important), any references in the 877 * file for which no peeled value is recorded is not peelable. This 878 * trait should typically be written alongside "peeled" for 879 * compatibility with older clients, but we do not require it 880 * (i.e., "peeled" is a no-op if "fully-peeled" is set). 881 */ 882static voidread_packed_refs(FILE*f,struct ref_dir *dir) 883{ 884struct ref_entry *last = NULL; 885char refline[PATH_MAX]; 886enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; 887 888while(fgets(refline,sizeof(refline), f)) { 889unsigned char sha1[20]; 890const char*refname; 891static const char header[] ="# pack-refs with:"; 892 893if(!strncmp(refline, header,sizeof(header)-1)) { 894const char*traits = refline +sizeof(header) -1; 895if(strstr(traits," fully-peeled ")) 896 peeled = PEELED_FULLY; 897else if(strstr(traits," peeled ")) 898 peeled = PEELED_TAGS; 899/* perhaps other traits later as well */ 900continue; 901} 902 903 refname =parse_ref_line(refline, sha1); 904if(refname) { 905 last =create_ref_entry(refname, sha1, REF_ISPACKED,1); 906if(peeled == PEELED_FULLY || 907(peeled == PEELED_TAGS && !prefixcmp(refname,"refs/tags/"))) 908 last->flag |= REF_KNOWS_PEELED; 909add_ref(dir, last); 910continue; 911} 912if(last && 913 refline[0] =='^'&& 914strlen(refline) == PEELED_LINE_LENGTH && 915 refline[PEELED_LINE_LENGTH -1] =='\n'&& 916!get_sha1_hex(refline +1, sha1)) { 917hashcpy(last->u.value.peeled, sha1); 918/* 919 * Regardless of what the file header said, 920 * we definitely know the value of *this* 921 * reference: 922 */ 923 last->flag |= REF_KNOWS_PEELED; 924} 925} 926} 927 928static struct ref_dir *get_packed_refs(struct ref_cache *refs) 929{ 930if(!refs->packed) { 931const char*packed_refs_file; 932FILE*f; 933 934 refs->packed =create_dir_entry(refs,"",0,0); 935if(*refs->name) 936 packed_refs_file =git_path_submodule(refs->name,"packed-refs"); 937else 938 packed_refs_file =git_path("packed-refs"); 939 f =fopen(packed_refs_file,"r"); 940if(f) { 941read_packed_refs(f,get_ref_dir(refs->packed)); 942fclose(f); 943} 944} 945returnget_ref_dir(refs->packed); 946} 947 948voidadd_packed_ref(const char*refname,const unsigned char*sha1) 949{ 950add_ref(get_packed_refs(get_ref_cache(NULL)), 951create_ref_entry(refname, sha1, REF_ISPACKED,1)); 952} 953 954/* 955 * Read the loose references from the namespace dirname into dir 956 * (without recursing). dirname must end with '/'. dir must be the 957 * directory entry corresponding to dirname. 958 */ 959static voidread_loose_refs(const char*dirname,struct ref_dir *dir) 960{ 961struct ref_cache *refs = dir->ref_cache; 962DIR*d; 963const char*path; 964struct dirent *de; 965int dirnamelen =strlen(dirname); 966struct strbuf refname; 967 968if(*refs->name) 969 path =git_path_submodule(refs->name,"%s", dirname); 970else 971 path =git_path("%s", dirname); 972 973 d =opendir(path); 974if(!d) 975return; 976 977strbuf_init(&refname, dirnamelen +257); 978strbuf_add(&refname, dirname, dirnamelen); 979 980while((de =readdir(d)) != NULL) { 981unsigned char sha1[20]; 982struct stat st; 983int flag; 984const char*refdir; 985 986if(de->d_name[0] =='.') 987continue; 988if(has_extension(de->d_name,".lock")) 989continue; 990strbuf_addstr(&refname, de->d_name); 991 refdir = *refs->name 992?git_path_submodule(refs->name,"%s", refname.buf) 993:git_path("%s", refname.buf); 994if(stat(refdir, &st) <0) { 995;/* silently ignore */ 996}else if(S_ISDIR(st.st_mode)) { 997strbuf_addch(&refname,'/'); 998add_entry_to_dir(dir, 999create_dir_entry(refs, refname.buf,1000 refname.len,1));1001}else{1002if(*refs->name) {1003hashclr(sha1);1004 flag =0;1005if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1006hashclr(sha1);1007 flag |= REF_ISBROKEN;1008}1009}else if(read_ref_full(refname.buf, sha1,1, &flag)) {1010hashclr(sha1);1011 flag |= REF_ISBROKEN;1012}1013add_entry_to_dir(dir,1014create_ref_entry(refname.buf, sha1, flag,1));1015}1016strbuf_setlen(&refname, dirnamelen);1017}1018strbuf_release(&refname);1019closedir(d);1020}10211022static struct ref_dir *get_loose_refs(struct ref_cache *refs)1023{1024if(!refs->loose) {1025/*1026 * Mark the top-level directory complete because we1027 * are about to read the only subdirectory that can1028 * hold references:1029 */1030 refs->loose =create_dir_entry(refs,"",0,0);1031/*1032 * Create an incomplete entry for "refs/":1033 */1034add_entry_to_dir(get_ref_dir(refs->loose),1035create_dir_entry(refs,"refs/",5,1));1036}1037returnget_ref_dir(refs->loose);1038}10391040/* We allow "recursive" symbolic refs. Only within reason, though */1041#define MAXDEPTH 51042#define MAXREFLEN (1024)10431044/*1045 * Called by resolve_gitlink_ref_recursive() after it failed to read1046 * from the loose refs in ref_cache refs. Find <refname> in the1047 * packed-refs file for the submodule.1048 */1049static intresolve_gitlink_packed_ref(struct ref_cache *refs,1050const char*refname,unsigned char*sha1)1051{1052struct ref_entry *ref;1053struct ref_dir *dir =get_packed_refs(refs);10541055 ref =find_ref(dir, refname);1056if(ref == NULL)1057return-1;10581059memcpy(sha1, ref->u.value.sha1,20);1060return0;1061}10621063static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1064const char*refname,unsigned char*sha1,1065int recursion)1066{1067int fd, len;1068char buffer[128], *p;1069char*path;10701071if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1072return-1;1073 path = *refs->name1074?git_path_submodule(refs->name,"%s", refname)1075:git_path("%s", refname);1076 fd =open(path, O_RDONLY);1077if(fd <0)1078returnresolve_gitlink_packed_ref(refs, refname, sha1);10791080 len =read(fd, buffer,sizeof(buffer)-1);1081close(fd);1082if(len <0)1083return-1;1084while(len &&isspace(buffer[len-1]))1085 len--;1086 buffer[len] =0;10871088/* Was it a detached head or an old-fashioned symlink? */1089if(!get_sha1_hex(buffer, sha1))1090return0;10911092/* Symref? */1093if(strncmp(buffer,"ref:",4))1094return-1;1095 p = buffer +4;1096while(isspace(*p))1097 p++;10981099returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1100}11011102intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1103{1104int len =strlen(path), retval;1105char*submodule;1106struct ref_cache *refs;11071108while(len && path[len-1] =='/')1109 len--;1110if(!len)1111return-1;1112 submodule =xstrndup(path, len);1113 refs =get_ref_cache(submodule);1114free(submodule);11151116 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1117return retval;1118}11191120/*1121 * Return the ref_entry for the given refname from the packed1122 * references. If it does not exist, return NULL.1123 */1124static struct ref_entry *get_packed_ref(const char*refname)1125{1126returnfind_ref(get_packed_refs(get_ref_cache(NULL)), refname);1127}11281129const char*resolve_ref_unsafe(const char*refname,unsigned char*sha1,int reading,int*flag)1130{1131int depth = MAXDEPTH;1132 ssize_t len;1133char buffer[256];1134static char refname_buffer[256];11351136if(flag)1137*flag =0;11381139if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1140return NULL;11411142for(;;) {1143char path[PATH_MAX];1144struct stat st;1145char*buf;1146int fd;11471148if(--depth <0)1149return NULL;11501151git_snpath(path,sizeof(path),"%s", refname);11521153if(lstat(path, &st) <0) {1154struct ref_entry *entry;11551156if(errno != ENOENT)1157return NULL;1158/*1159 * The loose reference file does not exist;1160 * check for a packed reference.1161 */1162 entry =get_packed_ref(refname);1163if(entry) {1164hashcpy(sha1, entry->u.value.sha1);1165if(flag)1166*flag |= REF_ISPACKED;1167return refname;1168}1169/* The reference is not a packed reference, either. */1170if(reading) {1171return NULL;1172}else{1173hashclr(sha1);1174return refname;1175}1176}11771178/* Follow "normalized" - ie "refs/.." symlinks by hand */1179if(S_ISLNK(st.st_mode)) {1180 len =readlink(path, buffer,sizeof(buffer)-1);1181if(len <0)1182return NULL;1183 buffer[len] =0;1184if(!prefixcmp(buffer,"refs/") &&1185!check_refname_format(buffer,0)) {1186strcpy(refname_buffer, buffer);1187 refname = refname_buffer;1188if(flag)1189*flag |= REF_ISSYMREF;1190continue;1191}1192}11931194/* Is it a directory? */1195if(S_ISDIR(st.st_mode)) {1196 errno = EISDIR;1197return NULL;1198}11991200/*1201 * Anything else, just open it and try to use it as1202 * a ref1203 */1204 fd =open(path, O_RDONLY);1205if(fd <0)1206return NULL;1207 len =read_in_full(fd, buffer,sizeof(buffer)-1);1208close(fd);1209if(len <0)1210return NULL;1211while(len &&isspace(buffer[len-1]))1212 len--;1213 buffer[len] ='\0';12141215/*1216 * Is it a symbolic ref?1217 */1218if(prefixcmp(buffer,"ref:"))1219break;1220if(flag)1221*flag |= REF_ISSYMREF;1222 buf = buffer +4;1223while(isspace(*buf))1224 buf++;1225if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1226if(flag)1227*flag |= REF_ISBROKEN;1228return NULL;1229}1230 refname =strcpy(refname_buffer, buf);1231}1232/* Please note that FETCH_HEAD has a second line containing other data. */1233if(get_sha1_hex(buffer, sha1) || (buffer[40] !='\0'&& !isspace(buffer[40]))) {1234if(flag)1235*flag |= REF_ISBROKEN;1236return NULL;1237}1238return refname;1239}12401241char*resolve_refdup(const char*ref,unsigned char*sha1,int reading,int*flag)1242{1243const char*ret =resolve_ref_unsafe(ref, sha1, reading, flag);1244return ret ?xstrdup(ret) : NULL;1245}12461247/* The argument to filter_refs */1248struct ref_filter {1249const char*pattern;1250 each_ref_fn *fn;1251void*cb_data;1252};12531254intread_ref_full(const char*refname,unsigned char*sha1,int reading,int*flags)1255{1256if(resolve_ref_unsafe(refname, sha1, reading, flags))1257return0;1258return-1;1259}12601261intread_ref(const char*refname,unsigned char*sha1)1262{1263returnread_ref_full(refname, sha1,1, NULL);1264}12651266intref_exists(const char*refname)1267{1268unsigned char sha1[20];1269return!!resolve_ref_unsafe(refname, sha1,1, NULL);1270}12711272static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1273void*data)1274{1275struct ref_filter *filter = (struct ref_filter *)data;1276if(fnmatch(filter->pattern, refname,0))1277return0;1278return filter->fn(refname, sha1, flags, filter->cb_data);1279}12801281enum peel_status {1282/* object was peeled successfully: */1283 PEEL_PEELED =0,12841285/*1286 * object cannot be peeled because the named object (or an1287 * object referred to by a tag in the peel chain), does not1288 * exist.1289 */1290 PEEL_INVALID = -1,12911292/* object cannot be peeled because it is not a tag: */1293 PEEL_NON_TAG = -2,12941295/* ref_entry contains no peeled value because it is a symref: */1296 PEEL_IS_SYMREF = -3,12971298/*1299 * ref_entry cannot be peeled because it is broken (i.e., the1300 * symbolic reference cannot even be resolved to an object1301 * name):1302 */1303 PEEL_BROKEN = -41304};13051306/*1307 * Peel the named object; i.e., if the object is a tag, resolve the1308 * tag recursively until a non-tag is found. If successful, store the1309 * result to sha1 and return PEEL_PEELED. If the object is not a tag1310 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1311 * and leave sha1 unchanged.1312 */1313static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1314{1315struct object *o =lookup_unknown_object(name);13161317if(o->type == OBJ_NONE) {1318int type =sha1_object_info(name, NULL);1319if(type <0)1320return PEEL_INVALID;1321 o->type = type;1322}13231324if(o->type != OBJ_TAG)1325return PEEL_NON_TAG;13261327 o =deref_tag_noverify(o);1328if(!o)1329return PEEL_INVALID;13301331hashcpy(sha1, o->sha1);1332return PEEL_PEELED;1333}13341335/*1336 * Peel the entry (if possible) and return its new peel_status.1337 */1338static enum peel_status peel_entry(struct ref_entry *entry)1339{1340enum peel_status status;13411342if(entry->flag & REF_KNOWS_PEELED)1343returnis_null_sha1(entry->u.value.peeled) ?1344 PEEL_NON_TAG : PEEL_PEELED;1345if(entry->flag & REF_ISBROKEN)1346return PEEL_BROKEN;1347if(entry->flag & REF_ISSYMREF)1348return PEEL_IS_SYMREF;13491350 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1351if(status == PEEL_PEELED || status == PEEL_NON_TAG)1352 entry->flag |= REF_KNOWS_PEELED;1353return status;1354}13551356intpeel_ref(const char*refname,unsigned char*sha1)1357{1358int flag;1359unsigned char base[20];13601361if(current_ref && (current_ref->name == refname1362|| !strcmp(current_ref->name, refname))) {1363if(peel_entry(current_ref))1364return-1;1365hashcpy(sha1, current_ref->u.value.peeled);1366return0;1367}13681369if(read_ref_full(refname, base,1, &flag))1370return-1;13711372/*1373 * If the reference is packed, read its ref_entry from the1374 * cache in the hope that we already know its peeled value.1375 * We only try this optimization on packed references because1376 * (a) forcing the filling of the loose reference cache could1377 * be expensive and (b) loose references anyway usually do not1378 * have REF_KNOWS_PEELED.1379 */1380if(flag & REF_ISPACKED) {1381struct ref_entry *r =get_packed_ref(refname);1382if(r) {1383if(peel_entry(r))1384return-1;1385hashcpy(sha1, r->u.value.peeled);1386return0;1387}1388}13891390returnpeel_object(base, sha1);1391}13921393struct warn_if_dangling_data {1394FILE*fp;1395const char*refname;1396const char*msg_fmt;1397};13981399static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1400int flags,void*cb_data)1401{1402struct warn_if_dangling_data *d = cb_data;1403const char*resolves_to;1404unsigned char junk[20];14051406if(!(flags & REF_ISSYMREF))1407return0;14081409 resolves_to =resolve_ref_unsafe(refname, junk,0, NULL);1410if(!resolves_to ||strcmp(resolves_to, d->refname))1411return0;14121413fprintf(d->fp, d->msg_fmt, refname);1414fputc('\n', d->fp);1415return0;1416}14171418voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1419{1420struct warn_if_dangling_data data;14211422 data.fp = fp;1423 data.refname = refname;1424 data.msg_fmt = msg_fmt;1425for_each_rawref(warn_if_dangling_symref, &data);1426}14271428/*1429 * Call fn for each reference in the specified submodule, omitting1430 * references not in the containing_dir of base. fn is called for all1431 * references, including broken ones. If fn ever returns a non-zero1432 * value, stop the iteration and return that value; otherwise, return1433 * 0.1434 */1435static intdo_for_each_entry(const char*submodule,const char*base,1436 each_ref_entry_fn fn,void*cb_data)1437{1438struct ref_cache *refs =get_ref_cache(submodule);1439struct ref_dir *packed_dir =get_packed_refs(refs);1440struct ref_dir *loose_dir =get_loose_refs(refs);1441int retval =0;14421443if(base && *base) {1444 packed_dir =find_containing_dir(packed_dir, base,0);1445 loose_dir =find_containing_dir(loose_dir, base,0);1446}14471448if(packed_dir && loose_dir) {1449sort_ref_dir(packed_dir);1450sort_ref_dir(loose_dir);1451 retval =do_for_each_entry_in_dirs(1452 packed_dir, loose_dir, fn, cb_data);1453}else if(packed_dir) {1454sort_ref_dir(packed_dir);1455 retval =do_for_each_entry_in_dir(1456 packed_dir,0, fn, cb_data);1457}else if(loose_dir) {1458sort_ref_dir(loose_dir);1459 retval =do_for_each_entry_in_dir(1460 loose_dir,0, fn, cb_data);1461}14621463return retval;1464}14651466/*1467 * Call fn for each reference in the specified submodule for which the1468 * refname begins with base. If trim is non-zero, then trim that many1469 * characters off the beginning of each refname before passing the1470 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1471 * broken references in the iteration. If fn ever returns a non-zero1472 * value, stop the iteration and return that value; otherwise, return1473 * 0.1474 */1475static intdo_for_each_ref(const char*submodule,const char*base, each_ref_fn fn,1476int trim,int flags,void*cb_data)1477{1478struct ref_entry_cb data;1479 data.base = base;1480 data.trim = trim;1481 data.flags = flags;1482 data.fn = fn;1483 data.cb_data = cb_data;14841485returndo_for_each_entry(submodule, base, do_one_ref, &data);1486}14871488static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1489{1490unsigned char sha1[20];1491int flag;14921493if(submodule) {1494if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1495returnfn("HEAD", sha1,0, cb_data);14961497return0;1498}14991500if(!read_ref_full("HEAD", sha1,1, &flag))1501returnfn("HEAD", sha1, flag, cb_data);15021503return0;1504}15051506inthead_ref(each_ref_fn fn,void*cb_data)1507{1508returndo_head_ref(NULL, fn, cb_data);1509}15101511inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1512{1513returndo_head_ref(submodule, fn, cb_data);1514}15151516intfor_each_ref(each_ref_fn fn,void*cb_data)1517{1518returndo_for_each_ref(NULL,"", fn,0,0, cb_data);1519}15201521intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1522{1523returndo_for_each_ref(submodule,"", fn,0,0, cb_data);1524}15251526intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1527{1528returndo_for_each_ref(NULL, prefix, fn,strlen(prefix),0, cb_data);1529}15301531intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1532 each_ref_fn fn,void*cb_data)1533{1534returndo_for_each_ref(submodule, prefix, fn,strlen(prefix),0, cb_data);1535}15361537intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1538{1539returnfor_each_ref_in("refs/tags/", fn, cb_data);1540}15411542intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1543{1544returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1545}15461547intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1548{1549returnfor_each_ref_in("refs/heads/", fn, cb_data);1550}15511552intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1553{1554returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);1555}15561557intfor_each_remote_ref(each_ref_fn fn,void*cb_data)1558{1559returnfor_each_ref_in("refs/remotes/", fn, cb_data);1560}15611562intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1563{1564returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);1565}15661567intfor_each_replace_ref(each_ref_fn fn,void*cb_data)1568{1569returndo_for_each_ref(NULL,"refs/replace/", fn,13,0, cb_data);1570}15711572inthead_ref_namespaced(each_ref_fn fn,void*cb_data)1573{1574struct strbuf buf = STRBUF_INIT;1575int ret =0;1576unsigned char sha1[20];1577int flag;15781579strbuf_addf(&buf,"%sHEAD",get_git_namespace());1580if(!read_ref_full(buf.buf, sha1,1, &flag))1581 ret =fn(buf.buf, sha1, flag, cb_data);1582strbuf_release(&buf);15831584return ret;1585}15861587intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)1588{1589struct strbuf buf = STRBUF_INIT;1590int ret;1591strbuf_addf(&buf,"%srefs/",get_git_namespace());1592 ret =do_for_each_ref(NULL, buf.buf, fn,0,0, cb_data);1593strbuf_release(&buf);1594return ret;1595}15961597intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,1598const char*prefix,void*cb_data)1599{1600struct strbuf real_pattern = STRBUF_INIT;1601struct ref_filter filter;1602int ret;16031604if(!prefix &&prefixcmp(pattern,"refs/"))1605strbuf_addstr(&real_pattern,"refs/");1606else if(prefix)1607strbuf_addstr(&real_pattern, prefix);1608strbuf_addstr(&real_pattern, pattern);16091610if(!has_glob_specials(pattern)) {1611/* Append implied '/' '*' if not present. */1612if(real_pattern.buf[real_pattern.len -1] !='/')1613strbuf_addch(&real_pattern,'/');1614/* No need to check for '*', there is none. */1615strbuf_addch(&real_pattern,'*');1616}16171618 filter.pattern = real_pattern.buf;1619 filter.fn = fn;1620 filter.cb_data = cb_data;1621 ret =for_each_ref(filter_refs, &filter);16221623strbuf_release(&real_pattern);1624return ret;1625}16261627intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)1628{1629returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);1630}16311632intfor_each_rawref(each_ref_fn fn,void*cb_data)1633{1634returndo_for_each_ref(NULL,"", fn,0,1635 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1636}16371638const char*prettify_refname(const char*name)1639{1640return name + (1641!prefixcmp(name,"refs/heads/") ?11:1642!prefixcmp(name,"refs/tags/") ?10:1643!prefixcmp(name,"refs/remotes/") ?13:16440);1645}16461647const char*ref_rev_parse_rules[] = {1648"%.*s",1649"refs/%.*s",1650"refs/tags/%.*s",1651"refs/heads/%.*s",1652"refs/remotes/%.*s",1653"refs/remotes/%.*s/HEAD",1654 NULL1655};16561657intrefname_match(const char*abbrev_name,const char*full_name,const char**rules)1658{1659const char**p;1660const int abbrev_name_len =strlen(abbrev_name);16611662for(p = rules; *p; p++) {1663if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {1664return1;1665}1666}16671668return0;1669}16701671static struct ref_lock *verify_lock(struct ref_lock *lock,1672const unsigned char*old_sha1,int mustexist)1673{1674if(read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {1675error("Can't verify ref%s", lock->ref_name);1676unlock_ref(lock);1677return NULL;1678}1679if(hashcmp(lock->old_sha1, old_sha1)) {1680error("Ref%sis at%sbut expected%s", lock->ref_name,1681sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));1682unlock_ref(lock);1683return NULL;1684}1685return lock;1686}16871688static intremove_empty_directories(const char*file)1689{1690/* we want to create a file but there is a directory there;1691 * if that is an empty directory (or a directory that contains1692 * only empty directories), remove them.1693 */1694struct strbuf path;1695int result;16961697strbuf_init(&path,20);1698strbuf_addstr(&path, file);16991700 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);17011702strbuf_release(&path);17031704return result;1705}17061707/*1708 * *string and *len will only be substituted, and *string returned (for1709 * later free()ing) if the string passed in is a magic short-hand form1710 * to name a branch.1711 */1712static char*substitute_branch_name(const char**string,int*len)1713{1714struct strbuf buf = STRBUF_INIT;1715int ret =interpret_branch_name(*string, &buf);17161717if(ret == *len) {1718size_t size;1719*string =strbuf_detach(&buf, &size);1720*len = size;1721return(char*)*string;1722}17231724return NULL;1725}17261727intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)1728{1729char*last_branch =substitute_branch_name(&str, &len);1730const char**p, *r;1731int refs_found =0;17321733*ref = NULL;1734for(p = ref_rev_parse_rules; *p; p++) {1735char fullref[PATH_MAX];1736unsigned char sha1_from_ref[20];1737unsigned char*this_result;1738int flag;17391740 this_result = refs_found ? sha1_from_ref : sha1;1741mksnpath(fullref,sizeof(fullref), *p, len, str);1742 r =resolve_ref_unsafe(fullref, this_result,1, &flag);1743if(r) {1744if(!refs_found++)1745*ref =xstrdup(r);1746if(!warn_ambiguous_refs)1747break;1748}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {1749warning("ignoring dangling symref%s.", fullref);1750}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {1751warning("ignoring broken ref%s.", fullref);1752}1753}1754free(last_branch);1755return refs_found;1756}17571758intdwim_log(const char*str,int len,unsigned char*sha1,char**log)1759{1760char*last_branch =substitute_branch_name(&str, &len);1761const char**p;1762int logs_found =0;17631764*log = NULL;1765for(p = ref_rev_parse_rules; *p; p++) {1766struct stat st;1767unsigned char hash[20];1768char path[PATH_MAX];1769const char*ref, *it;17701771mksnpath(path,sizeof(path), *p, len, str);1772 ref =resolve_ref_unsafe(path, hash,1, NULL);1773if(!ref)1774continue;1775if(!stat(git_path("logs/%s", path), &st) &&1776S_ISREG(st.st_mode))1777 it = path;1778else if(strcmp(ref, path) &&1779!stat(git_path("logs/%s", ref), &st) &&1780S_ISREG(st.st_mode))1781 it = ref;1782else1783continue;1784if(!logs_found++) {1785*log =xstrdup(it);1786hashcpy(sha1, hash);1787}1788if(!warn_ambiguous_refs)1789break;1790}1791free(last_branch);1792return logs_found;1793}17941795static struct ref_lock *lock_ref_sha1_basic(const char*refname,1796const unsigned char*old_sha1,1797int flags,int*type_p)1798{1799char*ref_file;1800const char*orig_refname = refname;1801struct ref_lock *lock;1802int last_errno =0;1803int type, lflags;1804int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1805int missing =0;18061807 lock =xcalloc(1,sizeof(struct ref_lock));1808 lock->lock_fd = -1;18091810 refname =resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);1811if(!refname && errno == EISDIR) {1812/* we are trying to lock foo but we used to1813 * have foo/bar which now does not exist;1814 * it is normal for the empty directory 'foo'1815 * to remain.1816 */1817 ref_file =git_path("%s", orig_refname);1818if(remove_empty_directories(ref_file)) {1819 last_errno = errno;1820error("there are still refs under '%s'", orig_refname);1821goto error_return;1822}1823 refname =resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);1824}1825if(type_p)1826*type_p = type;1827if(!refname) {1828 last_errno = errno;1829error("unable to resolve reference%s:%s",1830 orig_refname,strerror(errno));1831goto error_return;1832}1833 missing =is_null_sha1(lock->old_sha1);1834/* When the ref did not exist and we are creating it,1835 * make sure there is no existing ref that is packed1836 * whose name begins with our refname, nor a ref whose1837 * name is a proper prefix of our refname.1838 */1839if(missing &&1840!is_refname_available(refname, NULL,get_packed_refs(get_ref_cache(NULL)))) {1841 last_errno = ENOTDIR;1842goto error_return;1843}18441845 lock->lk =xcalloc(1,sizeof(struct lock_file));18461847 lflags = LOCK_DIE_ON_ERROR;1848if(flags & REF_NODEREF) {1849 refname = orig_refname;1850 lflags |= LOCK_NODEREF;1851}1852 lock->ref_name =xstrdup(refname);1853 lock->orig_ref_name =xstrdup(orig_refname);1854 ref_file =git_path("%s", refname);1855if(missing)1856 lock->force_write =1;1857if((flags & REF_NODEREF) && (type & REF_ISSYMREF))1858 lock->force_write =1;18591860if(safe_create_leading_directories(ref_file)) {1861 last_errno = errno;1862error("unable to create directory for%s", ref_file);1863goto error_return;1864}18651866 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);1867return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;18681869 error_return:1870unlock_ref(lock);1871 errno = last_errno;1872return NULL;1873}18741875struct ref_lock *lock_ref_sha1(const char*refname,const unsigned char*old_sha1)1876{1877char refpath[PATH_MAX];1878if(check_refname_format(refname,0))1879return NULL;1880strcpy(refpath,mkpath("refs/%s", refname));1881returnlock_ref_sha1_basic(refpath, old_sha1,0, NULL);1882}18831884struct ref_lock *lock_any_ref_for_update(const char*refname,1885const unsigned char*old_sha1,int flags)1886{1887if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1888return NULL;1889returnlock_ref_sha1_basic(refname, old_sha1, flags, NULL);1890}18911892struct repack_without_ref_sb {1893const char*refname;1894int fd;1895};18961897static intrepack_without_ref_fn(struct ref_entry *entry,void*cb_data)1898{1899struct repack_without_ref_sb *data = cb_data;1900char line[PATH_MAX +100];1901int len;19021903if(!strcmp(data->refname, entry->name))1904return0;1905if(!ref_resolves_to_object(entry))1906return0;/* Skip broken refs */1907 len =snprintf(line,sizeof(line),"%s %s\n",1908sha1_to_hex(entry->u.value.sha1), entry->name);1909/* this should not happen but just being defensive */1910if(len >sizeof(line))1911die("too long a refname '%s'", entry->name);1912write_or_die(data->fd, line, len);1913return0;1914}19151916static struct lock_file packlock;19171918static intrepack_without_ref(const char*refname)1919{1920struct repack_without_ref_sb data;1921struct ref_cache *refs =get_ref_cache(NULL);1922struct ref_dir *packed;19231924if(!get_packed_ref(refname))1925return0;/* refname does not exist in packed refs */19261927 data.refname = refname;1928 data.fd =hold_lock_file_for_update(&packlock,git_path("packed-refs"),0);1929if(data.fd <0) {1930unable_to_lock_error(git_path("packed-refs"), errno);1931returnerror("cannot delete '%s' from packed refs", refname);1932}1933clear_packed_ref_cache(refs);1934 packed =get_packed_refs(refs);1935do_for_each_entry_in_dir(packed,0, repack_without_ref_fn, &data);1936returncommit_lock_file(&packlock);1937}19381939intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)1940{1941struct ref_lock *lock;1942int err, i =0, ret =0, flag =0;19431944 lock =lock_ref_sha1_basic(refname, sha1, delopt, &flag);1945if(!lock)1946return1;1947if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {1948/* loose */1949 i =strlen(lock->lk->filename) -5;/* .lock */1950 lock->lk->filename[i] =0;1951 err =unlink_or_warn(lock->lk->filename);1952if(err && errno != ENOENT)1953 ret =1;19541955 lock->lk->filename[i] ='.';1956}1957/* removing the loose one could have resurrected an earlier1958 * packed one. Also, if it was not loose we need to repack1959 * without it.1960 */1961 ret |=repack_without_ref(lock->ref_name);19621963unlink_or_warn(git_path("logs/%s", lock->ref_name));1964invalidate_ref_cache(NULL);1965unlock_ref(lock);1966return ret;1967}19681969/*1970 * People using contrib's git-new-workdir have .git/logs/refs ->1971 * /some/other/path/.git/logs/refs, and that may live on another device.1972 *1973 * IOW, to avoid cross device rename errors, the temporary renamed log must1974 * live into logs/refs.1975 */1976#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"19771978intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)1979{1980unsigned char sha1[20], orig_sha1[20];1981int flag =0, logmoved =0;1982struct ref_lock *lock;1983struct stat loginfo;1984int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);1985const char*symref = NULL;1986struct ref_cache *refs =get_ref_cache(NULL);19871988if(log &&S_ISLNK(loginfo.st_mode))1989returnerror("reflog for%sis a symlink", oldrefname);19901991 symref =resolve_ref_unsafe(oldrefname, orig_sha1,1, &flag);1992if(flag & REF_ISSYMREF)1993returnerror("refname%sis a symbolic ref, renaming it is not supported",1994 oldrefname);1995if(!symref)1996returnerror("refname%snot found", oldrefname);19971998if(!is_refname_available(newrefname, oldrefname,get_packed_refs(refs)))1999return1;20002001if(!is_refname_available(newrefname, oldrefname,get_loose_refs(refs)))2002return1;20032004if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2005returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2006 oldrefname,strerror(errno));20072008if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2009error("unable to delete old%s", oldrefname);2010goto rollback;2011}20122013if(!read_ref_full(newrefname, sha1,1, &flag) &&2014delete_ref(newrefname, sha1, REF_NODEREF)) {2015if(errno==EISDIR) {2016if(remove_empty_directories(git_path("%s", newrefname))) {2017error("Directory not empty:%s", newrefname);2018goto rollback;2019}2020}else{2021error("unable to delete existing%s", newrefname);2022goto rollback;2023}2024}20252026if(log &&safe_create_leading_directories(git_path("logs/%s", newrefname))) {2027error("unable to create directory for%s", newrefname);2028goto rollback;2029}20302031 retry:2032if(log &&rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2033if(errno==EISDIR || errno==ENOTDIR) {2034/*2035 * rename(a, b) when b is an existing2036 * directory ought to result in ISDIR, but2037 * Solaris 5.8 gives ENOTDIR. Sheesh.2038 */2039if(remove_empty_directories(git_path("logs/%s", newrefname))) {2040error("Directory not empty: logs/%s", newrefname);2041goto rollback;2042}2043goto retry;2044}else{2045error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2046 newrefname,strerror(errno));2047goto rollback;2048}2049}2050 logmoved = log;20512052 lock =lock_ref_sha1_basic(newrefname, NULL,0, NULL);2053if(!lock) {2054error("unable to lock%sfor update", newrefname);2055goto rollback;2056}2057 lock->force_write =1;2058hashcpy(lock->old_sha1, orig_sha1);2059if(write_ref_sha1(lock, orig_sha1, logmsg)) {2060error("unable to write current sha1 into%s", newrefname);2061goto rollback;2062}20632064return0;20652066 rollback:2067 lock =lock_ref_sha1_basic(oldrefname, NULL,0, NULL);2068if(!lock) {2069error("unable to lock%sfor rollback", oldrefname);2070goto rollbacklog;2071}20722073 lock->force_write =1;2074 flag = log_all_ref_updates;2075 log_all_ref_updates =0;2076if(write_ref_sha1(lock, orig_sha1, NULL))2077error("unable to write current sha1 into%s", oldrefname);2078 log_all_ref_updates = flag;20792080 rollbacklog:2081if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2082error("unable to restore logfile%sfrom%s:%s",2083 oldrefname, newrefname,strerror(errno));2084if(!logmoved && log &&2085rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2086error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2087 oldrefname,strerror(errno));20882089return1;2090}20912092intclose_ref(struct ref_lock *lock)2093{2094if(close_lock_file(lock->lk))2095return-1;2096 lock->lock_fd = -1;2097return0;2098}20992100intcommit_ref(struct ref_lock *lock)2101{2102if(commit_lock_file(lock->lk))2103return-1;2104 lock->lock_fd = -1;2105return0;2106}21072108voidunlock_ref(struct ref_lock *lock)2109{2110/* Do not free lock->lk -- atexit() still looks at them */2111if(lock->lk)2112rollback_lock_file(lock->lk);2113free(lock->ref_name);2114free(lock->orig_ref_name);2115free(lock);2116}21172118/*2119 * copy the reflog message msg to buf, which has been allocated sufficiently2120 * large, while cleaning up the whitespaces. Especially, convert LF to space,2121 * because reflog file is one line per entry.2122 */2123static intcopy_msg(char*buf,const char*msg)2124{2125char*cp = buf;2126char c;2127int wasspace =1;21282129*cp++ ='\t';2130while((c = *msg++)) {2131if(wasspace &&isspace(c))2132continue;2133 wasspace =isspace(c);2134if(wasspace)2135 c =' ';2136*cp++ = c;2137}2138while(buf < cp &&isspace(cp[-1]))2139 cp--;2140*cp++ ='\n';2141return cp - buf;2142}21432144intlog_ref_setup(const char*refname,char*logfile,int bufsize)2145{2146int logfd, oflags = O_APPEND | O_WRONLY;21472148git_snpath(logfile, bufsize,"logs/%s", refname);2149if(log_all_ref_updates &&2150(!prefixcmp(refname,"refs/heads/") ||2151!prefixcmp(refname,"refs/remotes/") ||2152!prefixcmp(refname,"refs/notes/") ||2153!strcmp(refname,"HEAD"))) {2154if(safe_create_leading_directories(logfile) <0)2155returnerror("unable to create directory for%s",2156 logfile);2157 oflags |= O_CREAT;2158}21592160 logfd =open(logfile, oflags,0666);2161if(logfd <0) {2162if(!(oflags & O_CREAT) && errno == ENOENT)2163return0;21642165if((oflags & O_CREAT) && errno == EISDIR) {2166if(remove_empty_directories(logfile)) {2167returnerror("There are still logs under '%s'",2168 logfile);2169}2170 logfd =open(logfile, oflags,0666);2171}21722173if(logfd <0)2174returnerror("Unable to append to%s:%s",2175 logfile,strerror(errno));2176}21772178adjust_shared_perm(logfile);2179close(logfd);2180return0;2181}21822183static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2184const unsigned char*new_sha1,const char*msg)2185{2186int logfd, result, written, oflags = O_APPEND | O_WRONLY;2187unsigned maxlen, len;2188int msglen;2189char log_file[PATH_MAX];2190char*logrec;2191const char*committer;21922193if(log_all_ref_updates <0)2194 log_all_ref_updates = !is_bare_repository();21952196 result =log_ref_setup(refname, log_file,sizeof(log_file));2197if(result)2198return result;21992200 logfd =open(log_file, oflags);2201if(logfd <0)2202return0;2203 msglen = msg ?strlen(msg) :0;2204 committer =git_committer_info(0);2205 maxlen =strlen(committer) + msglen +100;2206 logrec =xmalloc(maxlen);2207 len =sprintf(logrec,"%s %s %s\n",2208sha1_to_hex(old_sha1),2209sha1_to_hex(new_sha1),2210 committer);2211if(msglen)2212 len +=copy_msg(logrec + len -1, msg) -1;2213 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;2214free(logrec);2215if(close(logfd) !=0|| written != len)2216returnerror("Unable to append to%s", log_file);2217return0;2218}22192220static intis_branch(const char*refname)2221{2222return!strcmp(refname,"HEAD") || !prefixcmp(refname,"refs/heads/");2223}22242225intwrite_ref_sha1(struct ref_lock *lock,2226const unsigned char*sha1,const char*logmsg)2227{2228static char term ='\n';2229struct object *o;22302231if(!lock)2232return-1;2233if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2234unlock_ref(lock);2235return0;2236}2237 o =parse_object(sha1);2238if(!o) {2239error("Trying to write ref%swith nonexistent object%s",2240 lock->ref_name,sha1_to_hex(sha1));2241unlock_ref(lock);2242return-1;2243}2244if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2245error("Trying to write non-commit object%sto branch%s",2246sha1_to_hex(sha1), lock->ref_name);2247unlock_ref(lock);2248return-1;2249}2250if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||2251write_in_full(lock->lock_fd, &term,1) !=12252||close_ref(lock) <0) {2253error("Couldn't write%s", lock->lk->filename);2254unlock_ref(lock);2255return-1;2256}2257clear_loose_ref_cache(get_ref_cache(NULL));2258if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||2259(strcmp(lock->ref_name, lock->orig_ref_name) &&2260log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {2261unlock_ref(lock);2262return-1;2263}2264if(strcmp(lock->orig_ref_name,"HEAD") !=0) {2265/*2266 * Special hack: If a branch is updated directly and HEAD2267 * points to it (may happen on the remote side of a push2268 * for example) then logically the HEAD reflog should be2269 * updated too.2270 * A generic solution implies reverse symref information,2271 * but finding all symrefs pointing to the given branch2272 * would be rather costly for this rare event (the direct2273 * update of a branch) to be worth it. So let's cheat and2274 * check with HEAD only which should cover 99% of all usage2275 * scenarios (even 100% of the default ones).2276 */2277unsigned char head_sha1[20];2278int head_flag;2279const char*head_ref;2280 head_ref =resolve_ref_unsafe("HEAD", head_sha1,1, &head_flag);2281if(head_ref && (head_flag & REF_ISSYMREF) &&2282!strcmp(head_ref, lock->ref_name))2283log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);2284}2285if(commit_ref(lock)) {2286error("Couldn't set%s", lock->ref_name);2287unlock_ref(lock);2288return-1;2289}2290unlock_ref(lock);2291return0;2292}22932294intcreate_symref(const char*ref_target,const char*refs_heads_master,2295const char*logmsg)2296{2297const char*lockpath;2298char ref[1000];2299int fd, len, written;2300char*git_HEAD =git_pathdup("%s", ref_target);2301unsigned char old_sha1[20], new_sha1[20];23022303if(logmsg &&read_ref(ref_target, old_sha1))2304hashclr(old_sha1);23052306if(safe_create_leading_directories(git_HEAD) <0)2307returnerror("unable to create directory for%s", git_HEAD);23082309#ifndef NO_SYMLINK_HEAD2310if(prefer_symlink_refs) {2311unlink(git_HEAD);2312if(!symlink(refs_heads_master, git_HEAD))2313goto done;2314fprintf(stderr,"no symlink - falling back to symbolic ref\n");2315}2316#endif23172318 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);2319if(sizeof(ref) <= len) {2320error("refname too long:%s", refs_heads_master);2321goto error_free_return;2322}2323 lockpath =mkpath("%s.lock", git_HEAD);2324 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);2325if(fd <0) {2326error("Unable to open%sfor writing", lockpath);2327goto error_free_return;2328}2329 written =write_in_full(fd, ref, len);2330if(close(fd) !=0|| written != len) {2331error("Unable to write to%s", lockpath);2332goto error_unlink_return;2333}2334if(rename(lockpath, git_HEAD) <0) {2335error("Unable to create%s", git_HEAD);2336goto error_unlink_return;2337}2338if(adjust_shared_perm(git_HEAD)) {2339error("Unable to fix permissions on%s", lockpath);2340 error_unlink_return:2341unlink_or_warn(lockpath);2342 error_free_return:2343free(git_HEAD);2344return-1;2345}23462347#ifndef NO_SYMLINK_HEAD2348 done:2349#endif2350if(logmsg && !read_ref(refs_heads_master, new_sha1))2351log_ref_write(ref_target, old_sha1, new_sha1, logmsg);23522353free(git_HEAD);2354return0;2355}23562357static char*ref_msg(const char*line,const char*endp)2358{2359const char*ep;2360 line +=82;2361 ep =memchr(line,'\n', endp - line);2362if(!ep)2363 ep = endp;2364returnxmemdupz(line, ep - line);2365}23662367intread_ref_at(const char*refname,unsigned long at_time,int cnt,2368unsigned char*sha1,char**msg,2369unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)2370{2371const char*logfile, *logdata, *logend, *rec, *lastgt, *lastrec;2372char*tz_c;2373int logfd, tz, reccnt =0;2374struct stat st;2375unsigned long date;2376unsigned char logged_sha1[20];2377void*log_mapped;2378size_t mapsz;23792380 logfile =git_path("logs/%s", refname);2381 logfd =open(logfile, O_RDONLY,0);2382if(logfd <0)2383die_errno("Unable to read log '%s'", logfile);2384fstat(logfd, &st);2385if(!st.st_size)2386die("Log%sis empty.", logfile);2387 mapsz =xsize_t(st.st_size);2388 log_mapped =xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd,0);2389 logdata = log_mapped;2390close(logfd);23912392 lastrec = NULL;2393 rec = logend = logdata + st.st_size;2394while(logdata < rec) {2395 reccnt++;2396if(logdata < rec && *(rec-1) =='\n')2397 rec--;2398 lastgt = NULL;2399while(logdata < rec && *(rec-1) !='\n') {2400 rec--;2401if(*rec =='>')2402 lastgt = rec;2403}2404if(!lastgt)2405die("Log%sis corrupt.", logfile);2406 date =strtoul(lastgt +1, &tz_c,10);2407if(date <= at_time || cnt ==0) {2408 tz =strtoul(tz_c, NULL,10);2409if(msg)2410*msg =ref_msg(rec, logend);2411if(cutoff_time)2412*cutoff_time = date;2413if(cutoff_tz)2414*cutoff_tz = tz;2415if(cutoff_cnt)2416*cutoff_cnt = reccnt -1;2417if(lastrec) {2418if(get_sha1_hex(lastrec, logged_sha1))2419die("Log%sis corrupt.", logfile);2420if(get_sha1_hex(rec +41, sha1))2421die("Log%sis corrupt.", logfile);2422if(hashcmp(logged_sha1, sha1)) {2423warning("Log%shas gap after%s.",2424 logfile,show_date(date, tz, DATE_RFC2822));2425}2426}2427else if(date == at_time) {2428if(get_sha1_hex(rec +41, sha1))2429die("Log%sis corrupt.", logfile);2430}2431else{2432if(get_sha1_hex(rec +41, logged_sha1))2433die("Log%sis corrupt.", logfile);2434if(hashcmp(logged_sha1, sha1)) {2435warning("Log%sunexpectedly ended on%s.",2436 logfile,show_date(date, tz, DATE_RFC2822));2437}2438}2439munmap(log_mapped, mapsz);2440return0;2441}2442 lastrec = rec;2443if(cnt >0)2444 cnt--;2445}24462447 rec = logdata;2448while(rec < logend && *rec !='>'&& *rec !='\n')2449 rec++;2450if(rec == logend || *rec =='\n')2451die("Log%sis corrupt.", logfile);2452 date =strtoul(rec +1, &tz_c,10);2453 tz =strtoul(tz_c, NULL,10);2454if(get_sha1_hex(logdata, sha1))2455die("Log%sis corrupt.", logfile);2456if(is_null_sha1(sha1)) {2457if(get_sha1_hex(logdata +41, sha1))2458die("Log%sis corrupt.", logfile);2459}2460if(msg)2461*msg =ref_msg(logdata, logend);2462munmap(log_mapped, mapsz);24632464if(cutoff_time)2465*cutoff_time = date;2466if(cutoff_tz)2467*cutoff_tz = tz;2468if(cutoff_cnt)2469*cutoff_cnt = reccnt;2470return1;2471}24722473intfor_each_recent_reflog_ent(const char*refname, each_reflog_ent_fn fn,long ofs,void*cb_data)2474{2475const char*logfile;2476FILE*logfp;2477struct strbuf sb = STRBUF_INIT;2478int ret =0;24792480 logfile =git_path("logs/%s", refname);2481 logfp =fopen(logfile,"r");2482if(!logfp)2483return-1;24842485if(ofs) {2486struct stat statbuf;2487if(fstat(fileno(logfp), &statbuf) ||2488 statbuf.st_size < ofs ||2489fseek(logfp, -ofs, SEEK_END) ||2490strbuf_getwholeline(&sb, logfp,'\n')) {2491fclose(logfp);2492strbuf_release(&sb);2493return-1;2494}2495}24962497while(!strbuf_getwholeline(&sb, logfp,'\n')) {2498unsigned char osha1[20], nsha1[20];2499char*email_end, *message;2500unsigned long timestamp;2501int tz;25022503/* old SP new SP name <email> SP time TAB msg LF */2504if(sb.len <83|| sb.buf[sb.len -1] !='\n'||2505get_sha1_hex(sb.buf, osha1) || sb.buf[40] !=' '||2506get_sha1_hex(sb.buf +41, nsha1) || sb.buf[81] !=' '||2507!(email_end =strchr(sb.buf +82,'>')) ||2508 email_end[1] !=' '||2509!(timestamp =strtoul(email_end +2, &message,10)) ||2510!message || message[0] !=' '||2511(message[1] !='+'&& message[1] !='-') ||2512!isdigit(message[2]) || !isdigit(message[3]) ||2513!isdigit(message[4]) || !isdigit(message[5]))2514continue;/* corrupt? */2515 email_end[1] ='\0';2516 tz =strtol(message +1, NULL,10);2517if(message[6] !='\t')2518 message +=6;2519else2520 message +=7;2521 ret =fn(osha1, nsha1, sb.buf +82, timestamp, tz, message,2522 cb_data);2523if(ret)2524break;2525}2526fclose(logfp);2527strbuf_release(&sb);2528return ret;2529}25302531intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)2532{2533returnfor_each_recent_reflog_ent(refname, fn,0, cb_data);2534}25352536/*2537 * Call fn for each reflog in the namespace indicated by name. name2538 * must be empty or end with '/'. Name will be used as a scratch2539 * space, but its contents will be restored before return.2540 */2541static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)2542{2543DIR*d =opendir(git_path("logs/%s", name->buf));2544int retval =0;2545struct dirent *de;2546int oldlen = name->len;25472548if(!d)2549return name->len ? errno :0;25502551while((de =readdir(d)) != NULL) {2552struct stat st;25532554if(de->d_name[0] =='.')2555continue;2556if(has_extension(de->d_name,".lock"))2557continue;2558strbuf_addstr(name, de->d_name);2559if(stat(git_path("logs/%s", name->buf), &st) <0) {2560;/* silently ignore */2561}else{2562if(S_ISDIR(st.st_mode)) {2563strbuf_addch(name,'/');2564 retval =do_for_each_reflog(name, fn, cb_data);2565}else{2566unsigned char sha1[20];2567if(read_ref_full(name->buf, sha1,0, NULL))2568 retval =error("bad ref for%s", name->buf);2569else2570 retval =fn(name->buf, sha1,0, cb_data);2571}2572if(retval)2573break;2574}2575strbuf_setlen(name, oldlen);2576}2577closedir(d);2578return retval;2579}25802581intfor_each_reflog(each_ref_fn fn,void*cb_data)2582{2583int retval;2584struct strbuf name;2585strbuf_init(&name, PATH_MAX);2586 retval =do_for_each_reflog(&name, fn, cb_data);2587strbuf_release(&name);2588return retval;2589}25902591intupdate_ref(const char*action,const char*refname,2592const unsigned char*sha1,const unsigned char*oldval,2593int flags,enum action_on_err onerr)2594{2595static struct ref_lock *lock;2596 lock =lock_any_ref_for_update(refname, oldval, flags);2597if(!lock) {2598const char*str ="Cannot lock the ref '%s'.";2599switch(onerr) {2600case MSG_ON_ERR:error(str, refname);break;2601case DIE_ON_ERR:die(str, refname);break;2602case QUIET_ON_ERR:break;2603}2604return1;2605}2606if(write_ref_sha1(lock, sha1, action) <0) {2607const char*str ="Cannot update the ref '%s'.";2608switch(onerr) {2609case MSG_ON_ERR:error(str, refname);break;2610case DIE_ON_ERR:die(str, refname);break;2611case QUIET_ON_ERR:break;2612}2613return1;2614}2615return0;2616}26172618struct ref *find_ref_by_name(const struct ref *list,const char*name)2619{2620for( ; list; list = list->next)2621if(!strcmp(list->name, name))2622return(struct ref *)list;2623return NULL;2624}26252626/*2627 * generate a format suitable for scanf from a ref_rev_parse_rules2628 * rule, that is replace the "%.*s" spec with a "%s" spec2629 */2630static voidgen_scanf_fmt(char*scanf_fmt,const char*rule)2631{2632char*spec;26332634 spec =strstr(rule,"%.*s");2635if(!spec ||strstr(spec +4,"%.*s"))2636die("invalid rule in ref_rev_parse_rules:%s", rule);26372638/* copy all until spec */2639strncpy(scanf_fmt, rule, spec - rule);2640 scanf_fmt[spec - rule] ='\0';2641/* copy new spec */2642strcat(scanf_fmt,"%s");2643/* copy remaining rule */2644strcat(scanf_fmt, spec +4);26452646return;2647}26482649char*shorten_unambiguous_ref(const char*refname,int strict)2650{2651int i;2652static char**scanf_fmts;2653static int nr_rules;2654char*short_name;26552656/* pre generate scanf formats from ref_rev_parse_rules[] */2657if(!nr_rules) {2658size_t total_len =0;26592660/* the rule list is NULL terminated, count them first */2661for(; ref_rev_parse_rules[nr_rules]; nr_rules++)2662/* no +1 because strlen("%s") < strlen("%.*s") */2663 total_len +=strlen(ref_rev_parse_rules[nr_rules]);26642665 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);26662667 total_len =0;2668for(i =0; i < nr_rules; i++) {2669 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules]2670+ total_len;2671gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);2672 total_len +=strlen(ref_rev_parse_rules[i]);2673}2674}26752676/* bail out if there are no rules */2677if(!nr_rules)2678returnxstrdup(refname);26792680/* buffer for scanf result, at most refname must fit */2681 short_name =xstrdup(refname);26822683/* skip first rule, it will always match */2684for(i = nr_rules -1; i >0; --i) {2685int j;2686int rules_to_fail = i;2687int short_name_len;26882689if(1!=sscanf(refname, scanf_fmts[i], short_name))2690continue;26912692 short_name_len =strlen(short_name);26932694/*2695 * in strict mode, all (except the matched one) rules2696 * must fail to resolve to a valid non-ambiguous ref2697 */2698if(strict)2699 rules_to_fail = nr_rules;27002701/*2702 * check if the short name resolves to a valid ref,2703 * but use only rules prior to the matched one2704 */2705for(j =0; j < rules_to_fail; j++) {2706const char*rule = ref_rev_parse_rules[j];2707char refname[PATH_MAX];27082709/* skip matched rule */2710if(i == j)2711continue;27122713/*2714 * the short name is ambiguous, if it resolves2715 * (with this previous rule) to a valid ref2716 * read_ref() returns 0 on success2717 */2718mksnpath(refname,sizeof(refname),2719 rule, short_name_len, short_name);2720if(ref_exists(refname))2721break;2722}27232724/*2725 * short name is non-ambiguous if all previous rules2726 * haven't resolved to a valid ref2727 */2728if(j == rules_to_fail)2729return short_name;2730}27312732free(short_name);2733returnxstrdup(refname);2734}