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 index of the entry with the given refname from the 371 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 372 * no such entry is found. dir must already be complete. 373 */ 374static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 375{ 376struct ref_entry **r; 377struct string_slice key; 378 379if(refname == NULL || !dir->nr) 380return-1; 381 382sort_ref_dir(dir); 383 key.len = len; 384 key.str = refname; 385 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 386 ref_entry_cmp_sslice); 387 388if(r == NULL) 389return-1; 390 391return r - dir->entries; 392} 393 394/* 395 * Search for a directory entry directly within dir (without 396 * recursing). Sort dir if necessary. subdirname must be a directory 397 * name (i.e., end in '/'). If mkdir is set, then create the 398 * directory if it is missing; otherwise, return NULL if the desired 399 * directory cannot be found. dir must already be complete. 400 */ 401static struct ref_dir *search_for_subdir(struct ref_dir *dir, 402const char*subdirname,size_t len, 403int mkdir) 404{ 405int entry_index =search_ref_dir(dir, subdirname, len); 406struct ref_entry *entry; 407if(entry_index == -1) { 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}else{ 419 entry = dir->entries[entry_index]; 420} 421returnget_ref_dir(entry); 422} 423 424/* 425 * If refname is a reference name, find the ref_dir within the dir 426 * tree that should hold refname. If refname is a directory name 427 * (i.e., ends in '/'), then return that ref_dir itself. dir must 428 * represent the top-level directory and must already be complete. 429 * Sort ref_dirs and recurse into subdirectories as necessary. If 430 * mkdir is set, then create any missing directories; otherwise, 431 * return NULL if the desired directory cannot be found. 432 */ 433static struct ref_dir *find_containing_dir(struct ref_dir *dir, 434const char*refname,int mkdir) 435{ 436const char*slash; 437for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 438size_t dirnamelen = slash - refname +1; 439struct ref_dir *subdir; 440 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 441if(!subdir) { 442 dir = NULL; 443break; 444} 445 dir = subdir; 446} 447 448return dir; 449} 450 451/* 452 * Find the value entry with the given name in dir, sorting ref_dirs 453 * and recursing into subdirectories as necessary. If the name is not 454 * found or it corresponds to a directory entry, return NULL. 455 */ 456static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 457{ 458int entry_index; 459struct ref_entry *entry; 460 dir =find_containing_dir(dir, refname,0); 461if(!dir) 462return NULL; 463 entry_index =search_ref_dir(dir, refname,strlen(refname)); 464if(entry_index == -1) 465return NULL; 466 entry = dir->entries[entry_index]; 467return(entry->flag & REF_DIR) ? NULL : entry; 468} 469 470/* 471 * Remove the entry with the given name from dir, recursing into 472 * subdirectories as necessary. If refname is the name of a directory 473 * (i.e., ends with '/'), then remove the directory and its contents. 474 * If the removal was successful, return the number of entries 475 * remaining in the directory entry that contained the deleted entry. 476 * If the name was not found, return -1. Please note that this 477 * function only deletes the entry from the cache; it does not delete 478 * it from the filesystem or ensure that other cache entries (which 479 * might be symbolic references to the removed entry) are updated. 480 * Nor does it remove any containing dir entries that might be made 481 * empty by the removal. dir must represent the top-level directory 482 * and must already be complete. 483 */ 484static intremove_entry(struct ref_dir *dir,const char*refname) 485{ 486int refname_len =strlen(refname); 487int entry_index; 488struct ref_entry *entry; 489int is_dir = refname[refname_len -1] =='/'; 490if(is_dir) { 491/* 492 * refname represents a reference directory. Remove 493 * the trailing slash; otherwise we will get the 494 * directory *representing* refname rather than the 495 * one *containing* it. 496 */ 497char*dirname =xmemdupz(refname, refname_len -1); 498 dir =find_containing_dir(dir, dirname,0); 499free(dirname); 500}else{ 501 dir =find_containing_dir(dir, refname,0); 502} 503if(!dir) 504return-1; 505 entry_index =search_ref_dir(dir, refname, refname_len); 506if(entry_index == -1) 507return-1; 508 entry = dir->entries[entry_index]; 509 510memmove(&dir->entries[entry_index], 511&dir->entries[entry_index +1], 512(dir->nr - entry_index -1) *sizeof(*dir->entries) 513); 514 dir->nr--; 515if(dir->sorted > entry_index) 516 dir->sorted--; 517free_ref_entry(entry); 518return dir->nr; 519} 520 521/* 522 * Add a ref_entry to the ref_dir (unsorted), recursing into 523 * subdirectories as necessary. dir must represent the top-level 524 * directory. Return 0 on success. 525 */ 526static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 527{ 528 dir =find_containing_dir(dir, ref->name,1); 529if(!dir) 530return-1; 531add_entry_to_dir(dir, ref); 532return0; 533} 534 535/* 536 * Emit a warning and return true iff ref1 and ref2 have the same name 537 * and the same sha1. Die if they have the same name but different 538 * sha1s. 539 */ 540static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 541{ 542if(strcmp(ref1->name, ref2->name)) 543return0; 544 545/* Duplicate name; make sure that they don't conflict: */ 546 547if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 548/* This is impossible by construction */ 549die("Reference directory conflict:%s", ref1->name); 550 551if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 552die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 553 554warning("Duplicated ref:%s", ref1->name); 555return1; 556} 557 558/* 559 * Sort the entries in dir non-recursively (if they are not already 560 * sorted) and remove any duplicate entries. 561 */ 562static voidsort_ref_dir(struct ref_dir *dir) 563{ 564int i, j; 565struct ref_entry *last = NULL; 566 567/* 568 * This check also prevents passing a zero-length array to qsort(), 569 * which is a problem on some platforms. 570 */ 571if(dir->sorted == dir->nr) 572return; 573 574qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 575 576/* Remove any duplicates: */ 577for(i =0, j =0; j < dir->nr; j++) { 578struct ref_entry *entry = dir->entries[j]; 579if(last &&is_dup_ref(last, entry)) 580free_ref_entry(entry); 581else 582 last = dir->entries[i++] = entry; 583} 584 dir->sorted = dir->nr = i; 585} 586 587/* Include broken references in a do_for_each_ref*() iteration: */ 588#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 589 590/* 591 * Return true iff the reference described by entry can be resolved to 592 * an object in the database. Emit a warning if the referred-to 593 * object does not exist. 594 */ 595static intref_resolves_to_object(struct ref_entry *entry) 596{ 597if(entry->flag & REF_ISBROKEN) 598return0; 599if(!has_sha1_file(entry->u.value.sha1)) { 600error("%sdoes not point to a valid object!", entry->name); 601return0; 602} 603return1; 604} 605 606/* 607 * current_ref is a performance hack: when iterating over references 608 * using the for_each_ref*() functions, current_ref is set to the 609 * current reference's entry before calling the callback function. If 610 * the callback function calls peel_ref(), then peel_ref() first 611 * checks whether the reference to be peeled is the current reference 612 * (it usually is) and if so, returns that reference's peeled version 613 * if it is available. This avoids a refname lookup in a common case. 614 */ 615static struct ref_entry *current_ref; 616 617typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 618 619struct ref_entry_cb { 620const char*base; 621int trim; 622int flags; 623 each_ref_fn *fn; 624void*cb_data; 625}; 626 627/* 628 * Handle one reference in a do_for_each_ref*()-style iteration, 629 * calling an each_ref_fn for each entry. 630 */ 631static intdo_one_ref(struct ref_entry *entry,void*cb_data) 632{ 633struct ref_entry_cb *data = cb_data; 634int retval; 635if(prefixcmp(entry->name, data->base)) 636return0; 637 638if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 639!ref_resolves_to_object(entry)) 640return0; 641 642 current_ref = entry; 643 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 644 entry->flag, data->cb_data); 645 current_ref = NULL; 646return retval; 647} 648 649/* 650 * Call fn for each reference in dir that has index in the range 651 * offset <= index < dir->nr. Recurse into subdirectories that are in 652 * that index range, sorting them before iterating. This function 653 * does not sort dir itself; it should be sorted beforehand. fn is 654 * called for all references, including broken ones. 655 */ 656static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 657 each_ref_entry_fn fn,void*cb_data) 658{ 659int i; 660assert(dir->sorted == dir->nr); 661for(i = offset; i < dir->nr; i++) { 662struct ref_entry *entry = dir->entries[i]; 663int retval; 664if(entry->flag & REF_DIR) { 665struct ref_dir *subdir =get_ref_dir(entry); 666sort_ref_dir(subdir); 667 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 668}else{ 669 retval =fn(entry, cb_data); 670} 671if(retval) 672return retval; 673} 674return0; 675} 676 677/* 678 * Call fn for each reference in the union of dir1 and dir2, in order 679 * by refname. Recurse into subdirectories. If a value entry appears 680 * in both dir1 and dir2, then only process the version that is in 681 * dir2. The input dirs must already be sorted, but subdirs will be 682 * sorted as needed. fn is called for all references, including 683 * broken ones. 684 */ 685static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 686struct ref_dir *dir2, 687 each_ref_entry_fn fn,void*cb_data) 688{ 689int retval; 690int i1 =0, i2 =0; 691 692assert(dir1->sorted == dir1->nr); 693assert(dir2->sorted == dir2->nr); 694while(1) { 695struct ref_entry *e1, *e2; 696int cmp; 697if(i1 == dir1->nr) { 698returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 699} 700if(i2 == dir2->nr) { 701returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 702} 703 e1 = dir1->entries[i1]; 704 e2 = dir2->entries[i2]; 705 cmp =strcmp(e1->name, e2->name); 706if(cmp ==0) { 707if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 708/* Both are directories; descend them in parallel. */ 709struct ref_dir *subdir1 =get_ref_dir(e1); 710struct ref_dir *subdir2 =get_ref_dir(e2); 711sort_ref_dir(subdir1); 712sort_ref_dir(subdir2); 713 retval =do_for_each_entry_in_dirs( 714 subdir1, subdir2, fn, cb_data); 715 i1++; 716 i2++; 717}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 718/* Both are references; ignore the one from dir1. */ 719 retval =fn(e2, cb_data); 720 i1++; 721 i2++; 722}else{ 723die("conflict between reference and directory:%s", 724 e1->name); 725} 726}else{ 727struct ref_entry *e; 728if(cmp <0) { 729 e = e1; 730 i1++; 731}else{ 732 e = e2; 733 i2++; 734} 735if(e->flag & REF_DIR) { 736struct ref_dir *subdir =get_ref_dir(e); 737sort_ref_dir(subdir); 738 retval =do_for_each_entry_in_dir( 739 subdir,0, fn, cb_data); 740}else{ 741 retval =fn(e, cb_data); 742} 743} 744if(retval) 745return retval; 746} 747} 748 749/* 750 * Return true iff refname1 and refname2 conflict with each other. 751 * Two reference names conflict if one of them exactly matches the 752 * leading components of the other; e.g., "foo/bar" conflicts with 753 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 754 * "foo/barbados". 755 */ 756static intnames_conflict(const char*refname1,const char*refname2) 757{ 758for(; *refname1 && *refname1 == *refname2; refname1++, refname2++) 759; 760return(*refname1 =='\0'&& *refname2 =='/') 761|| (*refname1 =='/'&& *refname2 =='\0'); 762} 763 764struct name_conflict_cb { 765const char*refname; 766const char*oldrefname; 767const char*conflicting_refname; 768}; 769 770static intname_conflict_fn(struct ref_entry *entry,void*cb_data) 771{ 772struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data; 773if(data->oldrefname && !strcmp(data->oldrefname, entry->name)) 774return0; 775if(names_conflict(data->refname, entry->name)) { 776 data->conflicting_refname = entry->name; 777return1; 778} 779return0; 780} 781 782/* 783 * Return true iff a reference named refname could be created without 784 * conflicting with the name of an existing reference in dir. If 785 * oldrefname is non-NULL, ignore potential conflicts with oldrefname 786 * (e.g., because oldrefname is scheduled for deletion in the same 787 * operation). 788 */ 789static intis_refname_available(const char*refname,const char*oldrefname, 790struct ref_dir *dir) 791{ 792struct name_conflict_cb data; 793 data.refname = refname; 794 data.oldrefname = oldrefname; 795 data.conflicting_refname = NULL; 796 797sort_ref_dir(dir); 798if(do_for_each_entry_in_dir(dir,0, name_conflict_fn, &data)) { 799error("'%s' exists; cannot create '%s'", 800 data.conflicting_refname, refname); 801return0; 802} 803return1; 804} 805 806/* 807 * Future: need to be in "struct repository" 808 * when doing a full libification. 809 */ 810static struct ref_cache { 811struct ref_cache *next; 812struct ref_entry *loose; 813struct ref_entry *packed; 814/* The submodule name, or "" for the main repo. */ 815char name[FLEX_ARRAY]; 816} *ref_cache; 817 818static voidclear_packed_ref_cache(struct ref_cache *refs) 819{ 820if(refs->packed) { 821free_ref_entry(refs->packed); 822 refs->packed = NULL; 823} 824} 825 826static voidclear_loose_ref_cache(struct ref_cache *refs) 827{ 828if(refs->loose) { 829free_ref_entry(refs->loose); 830 refs->loose = NULL; 831} 832} 833 834static struct ref_cache *create_ref_cache(const char*submodule) 835{ 836int len; 837struct ref_cache *refs; 838if(!submodule) 839 submodule =""; 840 len =strlen(submodule) +1; 841 refs =xcalloc(1,sizeof(struct ref_cache) + len); 842memcpy(refs->name, submodule, len); 843return refs; 844} 845 846/* 847 * Return a pointer to a ref_cache for the specified submodule. For 848 * the main repository, use submodule==NULL. The returned structure 849 * will be allocated and initialized but not necessarily populated; it 850 * should not be freed. 851 */ 852static struct ref_cache *get_ref_cache(const char*submodule) 853{ 854struct ref_cache *refs = ref_cache; 855if(!submodule) 856 submodule =""; 857while(refs) { 858if(!strcmp(submodule, refs->name)) 859return refs; 860 refs = refs->next; 861} 862 863 refs =create_ref_cache(submodule); 864 refs->next = ref_cache; 865 ref_cache = refs; 866return refs; 867} 868 869voidinvalidate_ref_cache(const char*submodule) 870{ 871struct ref_cache *refs =get_ref_cache(submodule); 872clear_packed_ref_cache(refs); 873clear_loose_ref_cache(refs); 874} 875 876/* The length of a peeled reference line in packed-refs, including EOL: */ 877#define PEELED_LINE_LENGTH 42 878 879/* 880 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 881 * Return a pointer to the refname within the line (null-terminated), 882 * or NULL if there was a problem. 883 */ 884static const char*parse_ref_line(char*line,unsigned char*sha1) 885{ 886/* 887 * 42: the answer to everything. 888 * 889 * In this case, it happens to be the answer to 890 * 40 (length of sha1 hex representation) 891 * +1 (space in between hex and name) 892 * +1 (newline at the end of the line) 893 */ 894int len =strlen(line) -42; 895 896if(len <=0) 897return NULL; 898if(get_sha1_hex(line, sha1) <0) 899return NULL; 900if(!isspace(line[40])) 901return NULL; 902 line +=41; 903if(isspace(*line)) 904return NULL; 905if(line[len] !='\n') 906return NULL; 907 line[len] =0; 908 909return line; 910} 911 912/* 913 * Read f, which is a packed-refs file, into dir. 914 * 915 * A comment line of the form "# pack-refs with: " may contain zero or 916 * more traits. We interpret the traits as follows: 917 * 918 * No traits: 919 * 920 * Probably no references are peeled. But if the file contains a 921 * peeled value for a reference, we will use it. 922 * 923 * peeled: 924 * 925 * References under "refs/tags/", if they *can* be peeled, *are* 926 * peeled in this file. References outside of "refs/tags/" are 927 * probably not peeled even if they could have been, but if we find 928 * a peeled value for such a reference we will use it. 929 * 930 * fully-peeled: 931 * 932 * All references in the file that can be peeled are peeled. 933 * Inversely (and this is more important), any references in the 934 * file for which no peeled value is recorded is not peelable. This 935 * trait should typically be written alongside "peeled" for 936 * compatibility with older clients, but we do not require it 937 * (i.e., "peeled" is a no-op if "fully-peeled" is set). 938 */ 939static voidread_packed_refs(FILE*f,struct ref_dir *dir) 940{ 941struct ref_entry *last = NULL; 942char refline[PATH_MAX]; 943enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; 944 945while(fgets(refline,sizeof(refline), f)) { 946unsigned char sha1[20]; 947const char*refname; 948static const char header[] ="# pack-refs with:"; 949 950if(!strncmp(refline, header,sizeof(header)-1)) { 951const char*traits = refline +sizeof(header) -1; 952if(strstr(traits," fully-peeled ")) 953 peeled = PEELED_FULLY; 954else if(strstr(traits," peeled ")) 955 peeled = PEELED_TAGS; 956/* perhaps other traits later as well */ 957continue; 958} 959 960 refname =parse_ref_line(refline, sha1); 961if(refname) { 962 last =create_ref_entry(refname, sha1, REF_ISPACKED,1); 963if(peeled == PEELED_FULLY || 964(peeled == PEELED_TAGS && !prefixcmp(refname,"refs/tags/"))) 965 last->flag |= REF_KNOWS_PEELED; 966add_ref(dir, last); 967continue; 968} 969if(last && 970 refline[0] =='^'&& 971strlen(refline) == PEELED_LINE_LENGTH && 972 refline[PEELED_LINE_LENGTH -1] =='\n'&& 973!get_sha1_hex(refline +1, sha1)) { 974hashcpy(last->u.value.peeled, sha1); 975/* 976 * Regardless of what the file header said, 977 * we definitely know the value of *this* 978 * reference: 979 */ 980 last->flag |= REF_KNOWS_PEELED; 981} 982} 983} 984 985static struct ref_dir *get_packed_refs(struct ref_cache *refs) 986{ 987if(!refs->packed) { 988const char*packed_refs_file; 989FILE*f; 990 991 refs->packed =create_dir_entry(refs,"",0,0); 992if(*refs->name) 993 packed_refs_file =git_path_submodule(refs->name,"packed-refs"); 994else 995 packed_refs_file =git_path("packed-refs"); 996 f =fopen(packed_refs_file,"r"); 997if(f) { 998read_packed_refs(f,get_ref_dir(refs->packed)); 999fclose(f);1000}1001}1002returnget_ref_dir(refs->packed);1003}10041005voidadd_packed_ref(const char*refname,const unsigned char*sha1)1006{1007add_ref(get_packed_refs(get_ref_cache(NULL)),1008create_ref_entry(refname, sha1, REF_ISPACKED,1));1009}10101011/*1012 * Read the loose references from the namespace dirname into dir1013 * (without recursing). dirname must end with '/'. dir must be the1014 * directory entry corresponding to dirname.1015 */1016static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1017{1018struct ref_cache *refs = dir->ref_cache;1019DIR*d;1020const char*path;1021struct dirent *de;1022int dirnamelen =strlen(dirname);1023struct strbuf refname;10241025if(*refs->name)1026 path =git_path_submodule(refs->name,"%s", dirname);1027else1028 path =git_path("%s", dirname);10291030 d =opendir(path);1031if(!d)1032return;10331034strbuf_init(&refname, dirnamelen +257);1035strbuf_add(&refname, dirname, dirnamelen);10361037while((de =readdir(d)) != NULL) {1038unsigned char sha1[20];1039struct stat st;1040int flag;1041const char*refdir;10421043if(de->d_name[0] =='.')1044continue;1045if(has_extension(de->d_name,".lock"))1046continue;1047strbuf_addstr(&refname, de->d_name);1048 refdir = *refs->name1049?git_path_submodule(refs->name,"%s", refname.buf)1050:git_path("%s", refname.buf);1051if(stat(refdir, &st) <0) {1052;/* silently ignore */1053}else if(S_ISDIR(st.st_mode)) {1054strbuf_addch(&refname,'/');1055add_entry_to_dir(dir,1056create_dir_entry(refs, refname.buf,1057 refname.len,1));1058}else{1059if(*refs->name) {1060hashclr(sha1);1061 flag =0;1062if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1063hashclr(sha1);1064 flag |= REF_ISBROKEN;1065}1066}else if(read_ref_full(refname.buf, sha1,1, &flag)) {1067hashclr(sha1);1068 flag |= REF_ISBROKEN;1069}1070add_entry_to_dir(dir,1071create_ref_entry(refname.buf, sha1, flag,1));1072}1073strbuf_setlen(&refname, dirnamelen);1074}1075strbuf_release(&refname);1076closedir(d);1077}10781079static struct ref_dir *get_loose_refs(struct ref_cache *refs)1080{1081if(!refs->loose) {1082/*1083 * Mark the top-level directory complete because we1084 * are about to read the only subdirectory that can1085 * hold references:1086 */1087 refs->loose =create_dir_entry(refs,"",0,0);1088/*1089 * Create an incomplete entry for "refs/":1090 */1091add_entry_to_dir(get_ref_dir(refs->loose),1092create_dir_entry(refs,"refs/",5,1));1093}1094returnget_ref_dir(refs->loose);1095}10961097/* We allow "recursive" symbolic refs. Only within reason, though */1098#define MAXDEPTH 51099#define MAXREFLEN (1024)11001101/*1102 * Called by resolve_gitlink_ref_recursive() after it failed to read1103 * from the loose refs in ref_cache refs. Find <refname> in the1104 * packed-refs file for the submodule.1105 */1106static intresolve_gitlink_packed_ref(struct ref_cache *refs,1107const char*refname,unsigned char*sha1)1108{1109struct ref_entry *ref;1110struct ref_dir *dir =get_packed_refs(refs);11111112 ref =find_ref(dir, refname);1113if(ref == NULL)1114return-1;11151116memcpy(sha1, ref->u.value.sha1,20);1117return0;1118}11191120static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1121const char*refname,unsigned char*sha1,1122int recursion)1123{1124int fd, len;1125char buffer[128], *p;1126char*path;11271128if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1129return-1;1130 path = *refs->name1131?git_path_submodule(refs->name,"%s", refname)1132:git_path("%s", refname);1133 fd =open(path, O_RDONLY);1134if(fd <0)1135returnresolve_gitlink_packed_ref(refs, refname, sha1);11361137 len =read(fd, buffer,sizeof(buffer)-1);1138close(fd);1139if(len <0)1140return-1;1141while(len &&isspace(buffer[len-1]))1142 len--;1143 buffer[len] =0;11441145/* Was it a detached head or an old-fashioned symlink? */1146if(!get_sha1_hex(buffer, sha1))1147return0;11481149/* Symref? */1150if(strncmp(buffer,"ref:",4))1151return-1;1152 p = buffer +4;1153while(isspace(*p))1154 p++;11551156returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1157}11581159intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1160{1161int len =strlen(path), retval;1162char*submodule;1163struct ref_cache *refs;11641165while(len && path[len-1] =='/')1166 len--;1167if(!len)1168return-1;1169 submodule =xstrndup(path, len);1170 refs =get_ref_cache(submodule);1171free(submodule);11721173 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1174return retval;1175}11761177/*1178 * Return the ref_entry for the given refname from the packed1179 * references. If it does not exist, return NULL.1180 */1181static struct ref_entry *get_packed_ref(const char*refname)1182{1183returnfind_ref(get_packed_refs(get_ref_cache(NULL)), refname);1184}11851186const char*resolve_ref_unsafe(const char*refname,unsigned char*sha1,int reading,int*flag)1187{1188int depth = MAXDEPTH;1189 ssize_t len;1190char buffer[256];1191static char refname_buffer[256];11921193if(flag)1194*flag =0;11951196if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1197return NULL;11981199for(;;) {1200char path[PATH_MAX];1201struct stat st;1202char*buf;1203int fd;12041205if(--depth <0)1206return NULL;12071208git_snpath(path,sizeof(path),"%s", refname);12091210if(lstat(path, &st) <0) {1211struct ref_entry *entry;12121213if(errno != ENOENT)1214return NULL;1215/*1216 * The loose reference file does not exist;1217 * check for a packed reference.1218 */1219 entry =get_packed_ref(refname);1220if(entry) {1221hashcpy(sha1, entry->u.value.sha1);1222if(flag)1223*flag |= REF_ISPACKED;1224return refname;1225}1226/* The reference is not a packed reference, either. */1227if(reading) {1228return NULL;1229}else{1230hashclr(sha1);1231return refname;1232}1233}12341235/* Follow "normalized" - ie "refs/.." symlinks by hand */1236if(S_ISLNK(st.st_mode)) {1237 len =readlink(path, buffer,sizeof(buffer)-1);1238if(len <0)1239return NULL;1240 buffer[len] =0;1241if(!prefixcmp(buffer,"refs/") &&1242!check_refname_format(buffer,0)) {1243strcpy(refname_buffer, buffer);1244 refname = refname_buffer;1245if(flag)1246*flag |= REF_ISSYMREF;1247continue;1248}1249}12501251/* Is it a directory? */1252if(S_ISDIR(st.st_mode)) {1253 errno = EISDIR;1254return NULL;1255}12561257/*1258 * Anything else, just open it and try to use it as1259 * a ref1260 */1261 fd =open(path, O_RDONLY);1262if(fd <0)1263return NULL;1264 len =read_in_full(fd, buffer,sizeof(buffer)-1);1265close(fd);1266if(len <0)1267return NULL;1268while(len &&isspace(buffer[len-1]))1269 len--;1270 buffer[len] ='\0';12711272/*1273 * Is it a symbolic ref?1274 */1275if(prefixcmp(buffer,"ref:"))1276break;1277if(flag)1278*flag |= REF_ISSYMREF;1279 buf = buffer +4;1280while(isspace(*buf))1281 buf++;1282if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1283if(flag)1284*flag |= REF_ISBROKEN;1285return NULL;1286}1287 refname =strcpy(refname_buffer, buf);1288}1289/* Please note that FETCH_HEAD has a second line containing other data. */1290if(get_sha1_hex(buffer, sha1) || (buffer[40] !='\0'&& !isspace(buffer[40]))) {1291if(flag)1292*flag |= REF_ISBROKEN;1293return NULL;1294}1295return refname;1296}12971298char*resolve_refdup(const char*ref,unsigned char*sha1,int reading,int*flag)1299{1300const char*ret =resolve_ref_unsafe(ref, sha1, reading, flag);1301return ret ?xstrdup(ret) : NULL;1302}13031304/* The argument to filter_refs */1305struct ref_filter {1306const char*pattern;1307 each_ref_fn *fn;1308void*cb_data;1309};13101311intread_ref_full(const char*refname,unsigned char*sha1,int reading,int*flags)1312{1313if(resolve_ref_unsafe(refname, sha1, reading, flags))1314return0;1315return-1;1316}13171318intread_ref(const char*refname,unsigned char*sha1)1319{1320returnread_ref_full(refname, sha1,1, NULL);1321}13221323intref_exists(const char*refname)1324{1325unsigned char sha1[20];1326return!!resolve_ref_unsafe(refname, sha1,1, NULL);1327}13281329static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1330void*data)1331{1332struct ref_filter *filter = (struct ref_filter *)data;1333if(fnmatch(filter->pattern, refname,0))1334return0;1335return filter->fn(refname, sha1, flags, filter->cb_data);1336}13371338enum peel_status {1339/* object was peeled successfully: */1340 PEEL_PEELED =0,13411342/*1343 * object cannot be peeled because the named object (or an1344 * object referred to by a tag in the peel chain), does not1345 * exist.1346 */1347 PEEL_INVALID = -1,13481349/* object cannot be peeled because it is not a tag: */1350 PEEL_NON_TAG = -2,13511352/* ref_entry contains no peeled value because it is a symref: */1353 PEEL_IS_SYMREF = -3,13541355/*1356 * ref_entry cannot be peeled because it is broken (i.e., the1357 * symbolic reference cannot even be resolved to an object1358 * name):1359 */1360 PEEL_BROKEN = -41361};13621363/*1364 * Peel the named object; i.e., if the object is a tag, resolve the1365 * tag recursively until a non-tag is found. If successful, store the1366 * result to sha1 and return PEEL_PEELED. If the object is not a tag1367 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1368 * and leave sha1 unchanged.1369 */1370static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1371{1372struct object *o =lookup_unknown_object(name);13731374if(o->type == OBJ_NONE) {1375int type =sha1_object_info(name, NULL);1376if(type <0)1377return PEEL_INVALID;1378 o->type = type;1379}13801381if(o->type != OBJ_TAG)1382return PEEL_NON_TAG;13831384 o =deref_tag_noverify(o);1385if(!o)1386return PEEL_INVALID;13871388hashcpy(sha1, o->sha1);1389return PEEL_PEELED;1390}13911392/*1393 * Peel the entry (if possible) and return its new peel_status.1394 */1395static enum peel_status peel_entry(struct ref_entry *entry)1396{1397enum peel_status status;13981399if(entry->flag & REF_KNOWS_PEELED)1400returnis_null_sha1(entry->u.value.peeled) ?1401 PEEL_NON_TAG : PEEL_PEELED;1402if(entry->flag & REF_ISBROKEN)1403return PEEL_BROKEN;1404if(entry->flag & REF_ISSYMREF)1405return PEEL_IS_SYMREF;14061407 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1408if(status == PEEL_PEELED || status == PEEL_NON_TAG)1409 entry->flag |= REF_KNOWS_PEELED;1410return status;1411}14121413intpeel_ref(const char*refname,unsigned char*sha1)1414{1415int flag;1416unsigned char base[20];14171418if(current_ref && (current_ref->name == refname1419|| !strcmp(current_ref->name, refname))) {1420if(peel_entry(current_ref))1421return-1;1422hashcpy(sha1, current_ref->u.value.peeled);1423return0;1424}14251426if(read_ref_full(refname, base,1, &flag))1427return-1;14281429/*1430 * If the reference is packed, read its ref_entry from the1431 * cache in the hope that we already know its peeled value.1432 * We only try this optimization on packed references because1433 * (a) forcing the filling of the loose reference cache could1434 * be expensive and (b) loose references anyway usually do not1435 * have REF_KNOWS_PEELED.1436 */1437if(flag & REF_ISPACKED) {1438struct ref_entry *r =get_packed_ref(refname);1439if(r) {1440if(peel_entry(r))1441return-1;1442hashcpy(sha1, r->u.value.peeled);1443return0;1444}1445}14461447returnpeel_object(base, sha1);1448}14491450struct warn_if_dangling_data {1451FILE*fp;1452const char*refname;1453const char*msg_fmt;1454};14551456static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1457int flags,void*cb_data)1458{1459struct warn_if_dangling_data *d = cb_data;1460const char*resolves_to;1461unsigned char junk[20];14621463if(!(flags & REF_ISSYMREF))1464return0;14651466 resolves_to =resolve_ref_unsafe(refname, junk,0, NULL);1467if(!resolves_to ||strcmp(resolves_to, d->refname))1468return0;14691470fprintf(d->fp, d->msg_fmt, refname);1471fputc('\n', d->fp);1472return0;1473}14741475voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1476{1477struct warn_if_dangling_data data;14781479 data.fp = fp;1480 data.refname = refname;1481 data.msg_fmt = msg_fmt;1482for_each_rawref(warn_if_dangling_symref, &data);1483}14841485/*1486 * Call fn for each reference in the specified submodule, omitting1487 * references not in the containing_dir of base. fn is called for all1488 * references, including broken ones. If fn ever returns a non-zero1489 * value, stop the iteration and return that value; otherwise, return1490 * 0.1491 */1492static intdo_for_each_entry(const char*submodule,const char*base,1493 each_ref_entry_fn fn,void*cb_data)1494{1495struct ref_cache *refs =get_ref_cache(submodule);1496struct ref_dir *packed_dir =get_packed_refs(refs);1497struct ref_dir *loose_dir =get_loose_refs(refs);1498int retval =0;14991500if(base && *base) {1501 packed_dir =find_containing_dir(packed_dir, base,0);1502 loose_dir =find_containing_dir(loose_dir, base,0);1503}15041505if(packed_dir && loose_dir) {1506sort_ref_dir(packed_dir);1507sort_ref_dir(loose_dir);1508 retval =do_for_each_entry_in_dirs(1509 packed_dir, loose_dir, fn, cb_data);1510}else if(packed_dir) {1511sort_ref_dir(packed_dir);1512 retval =do_for_each_entry_in_dir(1513 packed_dir,0, fn, cb_data);1514}else if(loose_dir) {1515sort_ref_dir(loose_dir);1516 retval =do_for_each_entry_in_dir(1517 loose_dir,0, fn, cb_data);1518}15191520return retval;1521}15221523/*1524 * Call fn for each reference in the specified submodule for which the1525 * refname begins with base. If trim is non-zero, then trim that many1526 * characters off the beginning of each refname before passing the1527 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1528 * broken references in the iteration. If fn ever returns a non-zero1529 * value, stop the iteration and return that value; otherwise, return1530 * 0.1531 */1532static intdo_for_each_ref(const char*submodule,const char*base, each_ref_fn fn,1533int trim,int flags,void*cb_data)1534{1535struct ref_entry_cb data;1536 data.base = base;1537 data.trim = trim;1538 data.flags = flags;1539 data.fn = fn;1540 data.cb_data = cb_data;15411542returndo_for_each_entry(submodule, base, do_one_ref, &data);1543}15441545static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1546{1547unsigned char sha1[20];1548int flag;15491550if(submodule) {1551if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1552returnfn("HEAD", sha1,0, cb_data);15531554return0;1555}15561557if(!read_ref_full("HEAD", sha1,1, &flag))1558returnfn("HEAD", sha1, flag, cb_data);15591560return0;1561}15621563inthead_ref(each_ref_fn fn,void*cb_data)1564{1565returndo_head_ref(NULL, fn, cb_data);1566}15671568inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1569{1570returndo_head_ref(submodule, fn, cb_data);1571}15721573intfor_each_ref(each_ref_fn fn,void*cb_data)1574{1575returndo_for_each_ref(NULL,"", fn,0,0, cb_data);1576}15771578intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1579{1580returndo_for_each_ref(submodule,"", fn,0,0, cb_data);1581}15821583intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1584{1585returndo_for_each_ref(NULL, prefix, fn,strlen(prefix),0, cb_data);1586}15871588intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1589 each_ref_fn fn,void*cb_data)1590{1591returndo_for_each_ref(submodule, prefix, fn,strlen(prefix),0, cb_data);1592}15931594intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1595{1596returnfor_each_ref_in("refs/tags/", fn, cb_data);1597}15981599intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1600{1601returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1602}16031604intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1605{1606returnfor_each_ref_in("refs/heads/", fn, cb_data);1607}16081609intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1610{1611returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);1612}16131614intfor_each_remote_ref(each_ref_fn fn,void*cb_data)1615{1616returnfor_each_ref_in("refs/remotes/", fn, cb_data);1617}16181619intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1620{1621returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);1622}16231624intfor_each_replace_ref(each_ref_fn fn,void*cb_data)1625{1626returndo_for_each_ref(NULL,"refs/replace/", fn,13,0, cb_data);1627}16281629inthead_ref_namespaced(each_ref_fn fn,void*cb_data)1630{1631struct strbuf buf = STRBUF_INIT;1632int ret =0;1633unsigned char sha1[20];1634int flag;16351636strbuf_addf(&buf,"%sHEAD",get_git_namespace());1637if(!read_ref_full(buf.buf, sha1,1, &flag))1638 ret =fn(buf.buf, sha1, flag, cb_data);1639strbuf_release(&buf);16401641return ret;1642}16431644intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)1645{1646struct strbuf buf = STRBUF_INIT;1647int ret;1648strbuf_addf(&buf,"%srefs/",get_git_namespace());1649 ret =do_for_each_ref(NULL, buf.buf, fn,0,0, cb_data);1650strbuf_release(&buf);1651return ret;1652}16531654intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,1655const char*prefix,void*cb_data)1656{1657struct strbuf real_pattern = STRBUF_INIT;1658struct ref_filter filter;1659int ret;16601661if(!prefix &&prefixcmp(pattern,"refs/"))1662strbuf_addstr(&real_pattern,"refs/");1663else if(prefix)1664strbuf_addstr(&real_pattern, prefix);1665strbuf_addstr(&real_pattern, pattern);16661667if(!has_glob_specials(pattern)) {1668/* Append implied '/' '*' if not present. */1669if(real_pattern.buf[real_pattern.len -1] !='/')1670strbuf_addch(&real_pattern,'/');1671/* No need to check for '*', there is none. */1672strbuf_addch(&real_pattern,'*');1673}16741675 filter.pattern = real_pattern.buf;1676 filter.fn = fn;1677 filter.cb_data = cb_data;1678 ret =for_each_ref(filter_refs, &filter);16791680strbuf_release(&real_pattern);1681return ret;1682}16831684intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)1685{1686returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);1687}16881689intfor_each_rawref(each_ref_fn fn,void*cb_data)1690{1691returndo_for_each_ref(NULL,"", fn,0,1692 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1693}16941695const char*prettify_refname(const char*name)1696{1697return name + (1698!prefixcmp(name,"refs/heads/") ?11:1699!prefixcmp(name,"refs/tags/") ?10:1700!prefixcmp(name,"refs/remotes/") ?13:17010);1702}17031704const char*ref_rev_parse_rules[] = {1705"%.*s",1706"refs/%.*s",1707"refs/tags/%.*s",1708"refs/heads/%.*s",1709"refs/remotes/%.*s",1710"refs/remotes/%.*s/HEAD",1711 NULL1712};17131714intrefname_match(const char*abbrev_name,const char*full_name,const char**rules)1715{1716const char**p;1717const int abbrev_name_len =strlen(abbrev_name);17181719for(p = rules; *p; p++) {1720if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {1721return1;1722}1723}17241725return0;1726}17271728static struct ref_lock *verify_lock(struct ref_lock *lock,1729const unsigned char*old_sha1,int mustexist)1730{1731if(read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {1732error("Can't verify ref%s", lock->ref_name);1733unlock_ref(lock);1734return NULL;1735}1736if(hashcmp(lock->old_sha1, old_sha1)) {1737error("Ref%sis at%sbut expected%s", lock->ref_name,1738sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));1739unlock_ref(lock);1740return NULL;1741}1742return lock;1743}17441745static intremove_empty_directories(const char*file)1746{1747/* we want to create a file but there is a directory there;1748 * if that is an empty directory (or a directory that contains1749 * only empty directories), remove them.1750 */1751struct strbuf path;1752int result;17531754strbuf_init(&path,20);1755strbuf_addstr(&path, file);17561757 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);17581759strbuf_release(&path);17601761return result;1762}17631764/*1765 * *string and *len will only be substituted, and *string returned (for1766 * later free()ing) if the string passed in is a magic short-hand form1767 * to name a branch.1768 */1769static char*substitute_branch_name(const char**string,int*len)1770{1771struct strbuf buf = STRBUF_INIT;1772int ret =interpret_branch_name(*string, &buf);17731774if(ret == *len) {1775size_t size;1776*string =strbuf_detach(&buf, &size);1777*len = size;1778return(char*)*string;1779}17801781return NULL;1782}17831784intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)1785{1786char*last_branch =substitute_branch_name(&str, &len);1787const char**p, *r;1788int refs_found =0;17891790*ref = NULL;1791for(p = ref_rev_parse_rules; *p; p++) {1792char fullref[PATH_MAX];1793unsigned char sha1_from_ref[20];1794unsigned char*this_result;1795int flag;17961797 this_result = refs_found ? sha1_from_ref : sha1;1798mksnpath(fullref,sizeof(fullref), *p, len, str);1799 r =resolve_ref_unsafe(fullref, this_result,1, &flag);1800if(r) {1801if(!refs_found++)1802*ref =xstrdup(r);1803if(!warn_ambiguous_refs)1804break;1805}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {1806warning("ignoring dangling symref%s.", fullref);1807}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {1808warning("ignoring broken ref%s.", fullref);1809}1810}1811free(last_branch);1812return refs_found;1813}18141815intdwim_log(const char*str,int len,unsigned char*sha1,char**log)1816{1817char*last_branch =substitute_branch_name(&str, &len);1818const char**p;1819int logs_found =0;18201821*log = NULL;1822for(p = ref_rev_parse_rules; *p; p++) {1823struct stat st;1824unsigned char hash[20];1825char path[PATH_MAX];1826const char*ref, *it;18271828mksnpath(path,sizeof(path), *p, len, str);1829 ref =resolve_ref_unsafe(path, hash,1, NULL);1830if(!ref)1831continue;1832if(!stat(git_path("logs/%s", path), &st) &&1833S_ISREG(st.st_mode))1834 it = path;1835else if(strcmp(ref, path) &&1836!stat(git_path("logs/%s", ref), &st) &&1837S_ISREG(st.st_mode))1838 it = ref;1839else1840continue;1841if(!logs_found++) {1842*log =xstrdup(it);1843hashcpy(sha1, hash);1844}1845if(!warn_ambiguous_refs)1846break;1847}1848free(last_branch);1849return logs_found;1850}18511852static struct ref_lock *lock_ref_sha1_basic(const char*refname,1853const unsigned char*old_sha1,1854int flags,int*type_p)1855{1856char*ref_file;1857const char*orig_refname = refname;1858struct ref_lock *lock;1859int last_errno =0;1860int type, lflags;1861int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1862int missing =0;18631864 lock =xcalloc(1,sizeof(struct ref_lock));1865 lock->lock_fd = -1;18661867 refname =resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);1868if(!refname && errno == EISDIR) {1869/* we are trying to lock foo but we used to1870 * have foo/bar which now does not exist;1871 * it is normal for the empty directory 'foo'1872 * to remain.1873 */1874 ref_file =git_path("%s", orig_refname);1875if(remove_empty_directories(ref_file)) {1876 last_errno = errno;1877error("there are still refs under '%s'", orig_refname);1878goto error_return;1879}1880 refname =resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);1881}1882if(type_p)1883*type_p = type;1884if(!refname) {1885 last_errno = errno;1886error("unable to resolve reference%s:%s",1887 orig_refname,strerror(errno));1888goto error_return;1889}1890 missing =is_null_sha1(lock->old_sha1);1891/* When the ref did not exist and we are creating it,1892 * make sure there is no existing ref that is packed1893 * whose name begins with our refname, nor a ref whose1894 * name is a proper prefix of our refname.1895 */1896if(missing &&1897!is_refname_available(refname, NULL,get_packed_refs(get_ref_cache(NULL)))) {1898 last_errno = ENOTDIR;1899goto error_return;1900}19011902 lock->lk =xcalloc(1,sizeof(struct lock_file));19031904 lflags = LOCK_DIE_ON_ERROR;1905if(flags & REF_NODEREF) {1906 refname = orig_refname;1907 lflags |= LOCK_NODEREF;1908}1909 lock->ref_name =xstrdup(refname);1910 lock->orig_ref_name =xstrdup(orig_refname);1911 ref_file =git_path("%s", refname);1912if(missing)1913 lock->force_write =1;1914if((flags & REF_NODEREF) && (type & REF_ISSYMREF))1915 lock->force_write =1;19161917if(safe_create_leading_directories(ref_file)) {1918 last_errno = errno;1919error("unable to create directory for%s", ref_file);1920goto error_return;1921}19221923 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);1924return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;19251926 error_return:1927unlock_ref(lock);1928 errno = last_errno;1929return NULL;1930}19311932struct ref_lock *lock_ref_sha1(const char*refname,const unsigned char*old_sha1)1933{1934char refpath[PATH_MAX];1935if(check_refname_format(refname,0))1936return NULL;1937strcpy(refpath,mkpath("refs/%s", refname));1938returnlock_ref_sha1_basic(refpath, old_sha1,0, NULL);1939}19401941struct ref_lock *lock_any_ref_for_update(const char*refname,1942const unsigned char*old_sha1,int flags)1943{1944if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1945return NULL;1946returnlock_ref_sha1_basic(refname, old_sha1, flags, NULL);1947}19481949static intrepack_ref_fn(struct ref_entry *entry,void*cb_data)1950{1951int*fd = cb_data;1952char line[PATH_MAX +100];1953int len;19541955if(entry->flag & REF_ISBROKEN) {1956/* This shouldn't happen to packed refs. */1957error("%sis broken!", entry->name);1958return0;1959}1960if(!has_sha1_file(entry->u.value.sha1)) {1961unsigned char sha1[20];1962int flags;19631964if(read_ref_full(entry->name, sha1,0, &flags))1965/* We should at least have found the packed ref. */1966die("Internal error");1967if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))1968/*1969 * This packed reference is overridden by a1970 * loose reference, so it is OK that its value1971 * is no longer valid; for example, it might1972 * refer to an object that has been garbage1973 * collected. For this purpose we don't even1974 * care whether the loose reference itself is1975 * invalid, broken, symbolic, etc. Silently1976 * omit the packed reference from the output.1977 */1978return0;1979/*1980 * There is no overriding loose reference, so the fact1981 * that this reference doesn't refer to a valid object1982 * indicates some kind of repository corruption.1983 * Report the problem, then omit the reference from1984 * the output.1985 */1986error("%sdoes not point to a valid object!", entry->name);1987return0;1988}19891990 len =snprintf(line,sizeof(line),"%s %s\n",1991sha1_to_hex(entry->u.value.sha1), entry->name);1992/* this should not happen but just being defensive */1993if(len >sizeof(line))1994die("too long a refname '%s'", entry->name);1995write_or_die(*fd, line, len);1996return0;1997}19981999static struct lock_file packlock;20002001static intrepack_without_ref(const char*refname)2002{2003int fd;2004struct ref_cache *refs =get_ref_cache(NULL);2005struct ref_dir *packed;20062007if(!get_packed_ref(refname))2008return0;/* refname does not exist in packed refs */20092010 fd =hold_lock_file_for_update(&packlock,git_path("packed-refs"),0);2011if(fd <0) {2012unable_to_lock_error(git_path("packed-refs"), errno);2013returnerror("cannot delete '%s' from packed refs", refname);2014}2015clear_packed_ref_cache(refs);2016 packed =get_packed_refs(refs);2017/* Remove refname from the cache. */2018if(remove_entry(packed, refname) == -1) {2019/*2020 * The packed entry disappeared while we were2021 * acquiring the lock.2022 */2023rollback_lock_file(&packlock);2024return0;2025}2026do_for_each_entry_in_dir(packed,0, repack_ref_fn, &fd);2027returncommit_lock_file(&packlock);2028}20292030intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2031{2032struct ref_lock *lock;2033int err, i =0, ret =0, flag =0;20342035 lock =lock_ref_sha1_basic(refname, sha1, delopt, &flag);2036if(!lock)2037return1;2038if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2039/* loose */2040 i =strlen(lock->lk->filename) -5;/* .lock */2041 lock->lk->filename[i] =0;2042 err =unlink_or_warn(lock->lk->filename);2043if(err && errno != ENOENT)2044 ret =1;20452046 lock->lk->filename[i] ='.';2047}2048/* removing the loose one could have resurrected an earlier2049 * packed one. Also, if it was not loose we need to repack2050 * without it.2051 */2052 ret |=repack_without_ref(lock->ref_name);20532054unlink_or_warn(git_path("logs/%s", lock->ref_name));2055clear_loose_ref_cache(get_ref_cache(NULL));2056unlock_ref(lock);2057return ret;2058}20592060/*2061 * People using contrib's git-new-workdir have .git/logs/refs ->2062 * /some/other/path/.git/logs/refs, and that may live on another device.2063 *2064 * IOW, to avoid cross device rename errors, the temporary renamed log must2065 * live into logs/refs.2066 */2067#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"20682069intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2070{2071unsigned char sha1[20], orig_sha1[20];2072int flag =0, logmoved =0;2073struct ref_lock *lock;2074struct stat loginfo;2075int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2076const char*symref = NULL;2077struct ref_cache *refs =get_ref_cache(NULL);20782079if(log &&S_ISLNK(loginfo.st_mode))2080returnerror("reflog for%sis a symlink", oldrefname);20812082 symref =resolve_ref_unsafe(oldrefname, orig_sha1,1, &flag);2083if(flag & REF_ISSYMREF)2084returnerror("refname%sis a symbolic ref, renaming it is not supported",2085 oldrefname);2086if(!symref)2087returnerror("refname%snot found", oldrefname);20882089if(!is_refname_available(newrefname, oldrefname,get_packed_refs(refs)))2090return1;20912092if(!is_refname_available(newrefname, oldrefname,get_loose_refs(refs)))2093return1;20942095if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2096returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2097 oldrefname,strerror(errno));20982099if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2100error("unable to delete old%s", oldrefname);2101goto rollback;2102}21032104if(!read_ref_full(newrefname, sha1,1, &flag) &&2105delete_ref(newrefname, sha1, REF_NODEREF)) {2106if(errno==EISDIR) {2107if(remove_empty_directories(git_path("%s", newrefname))) {2108error("Directory not empty:%s", newrefname);2109goto rollback;2110}2111}else{2112error("unable to delete existing%s", newrefname);2113goto rollback;2114}2115}21162117if(log &&safe_create_leading_directories(git_path("logs/%s", newrefname))) {2118error("unable to create directory for%s", newrefname);2119goto rollback;2120}21212122 retry:2123if(log &&rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2124if(errno==EISDIR || errno==ENOTDIR) {2125/*2126 * rename(a, b) when b is an existing2127 * directory ought to result in ISDIR, but2128 * Solaris 5.8 gives ENOTDIR. Sheesh.2129 */2130if(remove_empty_directories(git_path("logs/%s", newrefname))) {2131error("Directory not empty: logs/%s", newrefname);2132goto rollback;2133}2134goto retry;2135}else{2136error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2137 newrefname,strerror(errno));2138goto rollback;2139}2140}2141 logmoved = log;21422143 lock =lock_ref_sha1_basic(newrefname, NULL,0, NULL);2144if(!lock) {2145error("unable to lock%sfor update", newrefname);2146goto rollback;2147}2148 lock->force_write =1;2149hashcpy(lock->old_sha1, orig_sha1);2150if(write_ref_sha1(lock, orig_sha1, logmsg)) {2151error("unable to write current sha1 into%s", newrefname);2152goto rollback;2153}21542155return0;21562157 rollback:2158 lock =lock_ref_sha1_basic(oldrefname, NULL,0, NULL);2159if(!lock) {2160error("unable to lock%sfor rollback", oldrefname);2161goto rollbacklog;2162}21632164 lock->force_write =1;2165 flag = log_all_ref_updates;2166 log_all_ref_updates =0;2167if(write_ref_sha1(lock, orig_sha1, NULL))2168error("unable to write current sha1 into%s", oldrefname);2169 log_all_ref_updates = flag;21702171 rollbacklog:2172if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2173error("unable to restore logfile%sfrom%s:%s",2174 oldrefname, newrefname,strerror(errno));2175if(!logmoved && log &&2176rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2177error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2178 oldrefname,strerror(errno));21792180return1;2181}21822183intclose_ref(struct ref_lock *lock)2184{2185if(close_lock_file(lock->lk))2186return-1;2187 lock->lock_fd = -1;2188return0;2189}21902191intcommit_ref(struct ref_lock *lock)2192{2193if(commit_lock_file(lock->lk))2194return-1;2195 lock->lock_fd = -1;2196return0;2197}21982199voidunlock_ref(struct ref_lock *lock)2200{2201/* Do not free lock->lk -- atexit() still looks at them */2202if(lock->lk)2203rollback_lock_file(lock->lk);2204free(lock->ref_name);2205free(lock->orig_ref_name);2206free(lock);2207}22082209/*2210 * copy the reflog message msg to buf, which has been allocated sufficiently2211 * large, while cleaning up the whitespaces. Especially, convert LF to space,2212 * because reflog file is one line per entry.2213 */2214static intcopy_msg(char*buf,const char*msg)2215{2216char*cp = buf;2217char c;2218int wasspace =1;22192220*cp++ ='\t';2221while((c = *msg++)) {2222if(wasspace &&isspace(c))2223continue;2224 wasspace =isspace(c);2225if(wasspace)2226 c =' ';2227*cp++ = c;2228}2229while(buf < cp &&isspace(cp[-1]))2230 cp--;2231*cp++ ='\n';2232return cp - buf;2233}22342235intlog_ref_setup(const char*refname,char*logfile,int bufsize)2236{2237int logfd, oflags = O_APPEND | O_WRONLY;22382239git_snpath(logfile, bufsize,"logs/%s", refname);2240if(log_all_ref_updates &&2241(!prefixcmp(refname,"refs/heads/") ||2242!prefixcmp(refname,"refs/remotes/") ||2243!prefixcmp(refname,"refs/notes/") ||2244!strcmp(refname,"HEAD"))) {2245if(safe_create_leading_directories(logfile) <0)2246returnerror("unable to create directory for%s",2247 logfile);2248 oflags |= O_CREAT;2249}22502251 logfd =open(logfile, oflags,0666);2252if(logfd <0) {2253if(!(oflags & O_CREAT) && errno == ENOENT)2254return0;22552256if((oflags & O_CREAT) && errno == EISDIR) {2257if(remove_empty_directories(logfile)) {2258returnerror("There are still logs under '%s'",2259 logfile);2260}2261 logfd =open(logfile, oflags,0666);2262}22632264if(logfd <0)2265returnerror("Unable to append to%s:%s",2266 logfile,strerror(errno));2267}22682269adjust_shared_perm(logfile);2270close(logfd);2271return0;2272}22732274static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2275const unsigned char*new_sha1,const char*msg)2276{2277int logfd, result, written, oflags = O_APPEND | O_WRONLY;2278unsigned maxlen, len;2279int msglen;2280char log_file[PATH_MAX];2281char*logrec;2282const char*committer;22832284if(log_all_ref_updates <0)2285 log_all_ref_updates = !is_bare_repository();22862287 result =log_ref_setup(refname, log_file,sizeof(log_file));2288if(result)2289return result;22902291 logfd =open(log_file, oflags);2292if(logfd <0)2293return0;2294 msglen = msg ?strlen(msg) :0;2295 committer =git_committer_info(0);2296 maxlen =strlen(committer) + msglen +100;2297 logrec =xmalloc(maxlen);2298 len =sprintf(logrec,"%s %s %s\n",2299sha1_to_hex(old_sha1),2300sha1_to_hex(new_sha1),2301 committer);2302if(msglen)2303 len +=copy_msg(logrec + len -1, msg) -1;2304 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;2305free(logrec);2306if(close(logfd) !=0|| written != len)2307returnerror("Unable to append to%s", log_file);2308return0;2309}23102311static intis_branch(const char*refname)2312{2313return!strcmp(refname,"HEAD") || !prefixcmp(refname,"refs/heads/");2314}23152316intwrite_ref_sha1(struct ref_lock *lock,2317const unsigned char*sha1,const char*logmsg)2318{2319static char term ='\n';2320struct object *o;23212322if(!lock)2323return-1;2324if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2325unlock_ref(lock);2326return0;2327}2328 o =parse_object(sha1);2329if(!o) {2330error("Trying to write ref%swith nonexistent object%s",2331 lock->ref_name,sha1_to_hex(sha1));2332unlock_ref(lock);2333return-1;2334}2335if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2336error("Trying to write non-commit object%sto branch%s",2337sha1_to_hex(sha1), lock->ref_name);2338unlock_ref(lock);2339return-1;2340}2341if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||2342write_in_full(lock->lock_fd, &term,1) !=12343||close_ref(lock) <0) {2344error("Couldn't write%s", lock->lk->filename);2345unlock_ref(lock);2346return-1;2347}2348clear_loose_ref_cache(get_ref_cache(NULL));2349if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||2350(strcmp(lock->ref_name, lock->orig_ref_name) &&2351log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {2352unlock_ref(lock);2353return-1;2354}2355if(strcmp(lock->orig_ref_name,"HEAD") !=0) {2356/*2357 * Special hack: If a branch is updated directly and HEAD2358 * points to it (may happen on the remote side of a push2359 * for example) then logically the HEAD reflog should be2360 * updated too.2361 * A generic solution implies reverse symref information,2362 * but finding all symrefs pointing to the given branch2363 * would be rather costly for this rare event (the direct2364 * update of a branch) to be worth it. So let's cheat and2365 * check with HEAD only which should cover 99% of all usage2366 * scenarios (even 100% of the default ones).2367 */2368unsigned char head_sha1[20];2369int head_flag;2370const char*head_ref;2371 head_ref =resolve_ref_unsafe("HEAD", head_sha1,1, &head_flag);2372if(head_ref && (head_flag & REF_ISSYMREF) &&2373!strcmp(head_ref, lock->ref_name))2374log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);2375}2376if(commit_ref(lock)) {2377error("Couldn't set%s", lock->ref_name);2378unlock_ref(lock);2379return-1;2380}2381unlock_ref(lock);2382return0;2383}23842385intcreate_symref(const char*ref_target,const char*refs_heads_master,2386const char*logmsg)2387{2388const char*lockpath;2389char ref[1000];2390int fd, len, written;2391char*git_HEAD =git_pathdup("%s", ref_target);2392unsigned char old_sha1[20], new_sha1[20];23932394if(logmsg &&read_ref(ref_target, old_sha1))2395hashclr(old_sha1);23962397if(safe_create_leading_directories(git_HEAD) <0)2398returnerror("unable to create directory for%s", git_HEAD);23992400#ifndef NO_SYMLINK_HEAD2401if(prefer_symlink_refs) {2402unlink(git_HEAD);2403if(!symlink(refs_heads_master, git_HEAD))2404goto done;2405fprintf(stderr,"no symlink - falling back to symbolic ref\n");2406}2407#endif24082409 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);2410if(sizeof(ref) <= len) {2411error("refname too long:%s", refs_heads_master);2412goto error_free_return;2413}2414 lockpath =mkpath("%s.lock", git_HEAD);2415 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);2416if(fd <0) {2417error("Unable to open%sfor writing", lockpath);2418goto error_free_return;2419}2420 written =write_in_full(fd, ref, len);2421if(close(fd) !=0|| written != len) {2422error("Unable to write to%s", lockpath);2423goto error_unlink_return;2424}2425if(rename(lockpath, git_HEAD) <0) {2426error("Unable to create%s", git_HEAD);2427goto error_unlink_return;2428}2429if(adjust_shared_perm(git_HEAD)) {2430error("Unable to fix permissions on%s", lockpath);2431 error_unlink_return:2432unlink_or_warn(lockpath);2433 error_free_return:2434free(git_HEAD);2435return-1;2436}24372438#ifndef NO_SYMLINK_HEAD2439 done:2440#endif2441if(logmsg && !read_ref(refs_heads_master, new_sha1))2442log_ref_write(ref_target, old_sha1, new_sha1, logmsg);24432444free(git_HEAD);2445return0;2446}24472448static char*ref_msg(const char*line,const char*endp)2449{2450const char*ep;2451 line +=82;2452 ep =memchr(line,'\n', endp - line);2453if(!ep)2454 ep = endp;2455returnxmemdupz(line, ep - line);2456}24572458intread_ref_at(const char*refname,unsigned long at_time,int cnt,2459unsigned char*sha1,char**msg,2460unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)2461{2462const char*logfile, *logdata, *logend, *rec, *lastgt, *lastrec;2463char*tz_c;2464int logfd, tz, reccnt =0;2465struct stat st;2466unsigned long date;2467unsigned char logged_sha1[20];2468void*log_mapped;2469size_t mapsz;24702471 logfile =git_path("logs/%s", refname);2472 logfd =open(logfile, O_RDONLY,0);2473if(logfd <0)2474die_errno("Unable to read log '%s'", logfile);2475fstat(logfd, &st);2476if(!st.st_size)2477die("Log%sis empty.", logfile);2478 mapsz =xsize_t(st.st_size);2479 log_mapped =xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd,0);2480 logdata = log_mapped;2481close(logfd);24822483 lastrec = NULL;2484 rec = logend = logdata + st.st_size;2485while(logdata < rec) {2486 reccnt++;2487if(logdata < rec && *(rec-1) =='\n')2488 rec--;2489 lastgt = NULL;2490while(logdata < rec && *(rec-1) !='\n') {2491 rec--;2492if(*rec =='>')2493 lastgt = rec;2494}2495if(!lastgt)2496die("Log%sis corrupt.", logfile);2497 date =strtoul(lastgt +1, &tz_c,10);2498if(date <= at_time || cnt ==0) {2499 tz =strtoul(tz_c, NULL,10);2500if(msg)2501*msg =ref_msg(rec, logend);2502if(cutoff_time)2503*cutoff_time = date;2504if(cutoff_tz)2505*cutoff_tz = tz;2506if(cutoff_cnt)2507*cutoff_cnt = reccnt -1;2508if(lastrec) {2509if(get_sha1_hex(lastrec, logged_sha1))2510die("Log%sis corrupt.", logfile);2511if(get_sha1_hex(rec +41, sha1))2512die("Log%sis corrupt.", logfile);2513if(hashcmp(logged_sha1, sha1)) {2514warning("Log%shas gap after%s.",2515 logfile,show_date(date, tz, DATE_RFC2822));2516}2517}2518else if(date == at_time) {2519if(get_sha1_hex(rec +41, sha1))2520die("Log%sis corrupt.", logfile);2521}2522else{2523if(get_sha1_hex(rec +41, logged_sha1))2524die("Log%sis corrupt.", logfile);2525if(hashcmp(logged_sha1, sha1)) {2526warning("Log%sunexpectedly ended on%s.",2527 logfile,show_date(date, tz, DATE_RFC2822));2528}2529}2530munmap(log_mapped, mapsz);2531return0;2532}2533 lastrec = rec;2534if(cnt >0)2535 cnt--;2536}25372538 rec = logdata;2539while(rec < logend && *rec !='>'&& *rec !='\n')2540 rec++;2541if(rec == logend || *rec =='\n')2542die("Log%sis corrupt.", logfile);2543 date =strtoul(rec +1, &tz_c,10);2544 tz =strtoul(tz_c, NULL,10);2545if(get_sha1_hex(logdata, sha1))2546die("Log%sis corrupt.", logfile);2547if(is_null_sha1(sha1)) {2548if(get_sha1_hex(logdata +41, sha1))2549die("Log%sis corrupt.", logfile);2550}2551if(msg)2552*msg =ref_msg(logdata, logend);2553munmap(log_mapped, mapsz);25542555if(cutoff_time)2556*cutoff_time = date;2557if(cutoff_tz)2558*cutoff_tz = tz;2559if(cutoff_cnt)2560*cutoff_cnt = reccnt;2561return1;2562}25632564intfor_each_recent_reflog_ent(const char*refname, each_reflog_ent_fn fn,long ofs,void*cb_data)2565{2566const char*logfile;2567FILE*logfp;2568struct strbuf sb = STRBUF_INIT;2569int ret =0;25702571 logfile =git_path("logs/%s", refname);2572 logfp =fopen(logfile,"r");2573if(!logfp)2574return-1;25752576if(ofs) {2577struct stat statbuf;2578if(fstat(fileno(logfp), &statbuf) ||2579 statbuf.st_size < ofs ||2580fseek(logfp, -ofs, SEEK_END) ||2581strbuf_getwholeline(&sb, logfp,'\n')) {2582fclose(logfp);2583strbuf_release(&sb);2584return-1;2585}2586}25872588while(!strbuf_getwholeline(&sb, logfp,'\n')) {2589unsigned char osha1[20], nsha1[20];2590char*email_end, *message;2591unsigned long timestamp;2592int tz;25932594/* old SP new SP name <email> SP time TAB msg LF */2595if(sb.len <83|| sb.buf[sb.len -1] !='\n'||2596get_sha1_hex(sb.buf, osha1) || sb.buf[40] !=' '||2597get_sha1_hex(sb.buf +41, nsha1) || sb.buf[81] !=' '||2598!(email_end =strchr(sb.buf +82,'>')) ||2599 email_end[1] !=' '||2600!(timestamp =strtoul(email_end +2, &message,10)) ||2601!message || message[0] !=' '||2602(message[1] !='+'&& message[1] !='-') ||2603!isdigit(message[2]) || !isdigit(message[3]) ||2604!isdigit(message[4]) || !isdigit(message[5]))2605continue;/* corrupt? */2606 email_end[1] ='\0';2607 tz =strtol(message +1, NULL,10);2608if(message[6] !='\t')2609 message +=6;2610else2611 message +=7;2612 ret =fn(osha1, nsha1, sb.buf +82, timestamp, tz, message,2613 cb_data);2614if(ret)2615break;2616}2617fclose(logfp);2618strbuf_release(&sb);2619return ret;2620}26212622intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)2623{2624returnfor_each_recent_reflog_ent(refname, fn,0, cb_data);2625}26262627/*2628 * Call fn for each reflog in the namespace indicated by name. name2629 * must be empty or end with '/'. Name will be used as a scratch2630 * space, but its contents will be restored before return.2631 */2632static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)2633{2634DIR*d =opendir(git_path("logs/%s", name->buf));2635int retval =0;2636struct dirent *de;2637int oldlen = name->len;26382639if(!d)2640return name->len ? errno :0;26412642while((de =readdir(d)) != NULL) {2643struct stat st;26442645if(de->d_name[0] =='.')2646continue;2647if(has_extension(de->d_name,".lock"))2648continue;2649strbuf_addstr(name, de->d_name);2650if(stat(git_path("logs/%s", name->buf), &st) <0) {2651;/* silently ignore */2652}else{2653if(S_ISDIR(st.st_mode)) {2654strbuf_addch(name,'/');2655 retval =do_for_each_reflog(name, fn, cb_data);2656}else{2657unsigned char sha1[20];2658if(read_ref_full(name->buf, sha1,0, NULL))2659 retval =error("bad ref for%s", name->buf);2660else2661 retval =fn(name->buf, sha1,0, cb_data);2662}2663if(retval)2664break;2665}2666strbuf_setlen(name, oldlen);2667}2668closedir(d);2669return retval;2670}26712672intfor_each_reflog(each_ref_fn fn,void*cb_data)2673{2674int retval;2675struct strbuf name;2676strbuf_init(&name, PATH_MAX);2677 retval =do_for_each_reflog(&name, fn, cb_data);2678strbuf_release(&name);2679return retval;2680}26812682intupdate_ref(const char*action,const char*refname,2683const unsigned char*sha1,const unsigned char*oldval,2684int flags,enum action_on_err onerr)2685{2686static struct ref_lock *lock;2687 lock =lock_any_ref_for_update(refname, oldval, flags);2688if(!lock) {2689const char*str ="Cannot lock the ref '%s'.";2690switch(onerr) {2691case MSG_ON_ERR:error(str, refname);break;2692case DIE_ON_ERR:die(str, refname);break;2693case QUIET_ON_ERR:break;2694}2695return1;2696}2697if(write_ref_sha1(lock, sha1, action) <0) {2698const char*str ="Cannot update the ref '%s'.";2699switch(onerr) {2700case MSG_ON_ERR:error(str, refname);break;2701case DIE_ON_ERR:die(str, refname);break;2702case QUIET_ON_ERR:break;2703}2704return1;2705}2706return0;2707}27082709struct ref *find_ref_by_name(const struct ref *list,const char*name)2710{2711for( ; list; list = list->next)2712if(!strcmp(list->name, name))2713return(struct ref *)list;2714return NULL;2715}27162717/*2718 * generate a format suitable for scanf from a ref_rev_parse_rules2719 * rule, that is replace the "%.*s" spec with a "%s" spec2720 */2721static voidgen_scanf_fmt(char*scanf_fmt,const char*rule)2722{2723char*spec;27242725 spec =strstr(rule,"%.*s");2726if(!spec ||strstr(spec +4,"%.*s"))2727die("invalid rule in ref_rev_parse_rules:%s", rule);27282729/* copy all until spec */2730strncpy(scanf_fmt, rule, spec - rule);2731 scanf_fmt[spec - rule] ='\0';2732/* copy new spec */2733strcat(scanf_fmt,"%s");2734/* copy remaining rule */2735strcat(scanf_fmt, spec +4);27362737return;2738}27392740char*shorten_unambiguous_ref(const char*refname,int strict)2741{2742int i;2743static char**scanf_fmts;2744static int nr_rules;2745char*short_name;27462747/* pre generate scanf formats from ref_rev_parse_rules[] */2748if(!nr_rules) {2749size_t total_len =0;27502751/* the rule list is NULL terminated, count them first */2752for(; ref_rev_parse_rules[nr_rules]; nr_rules++)2753/* no +1 because strlen("%s") < strlen("%.*s") */2754 total_len +=strlen(ref_rev_parse_rules[nr_rules]);27552756 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);27572758 total_len =0;2759for(i =0; i < nr_rules; i++) {2760 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules]2761+ total_len;2762gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);2763 total_len +=strlen(ref_rev_parse_rules[i]);2764}2765}27662767/* bail out if there are no rules */2768if(!nr_rules)2769returnxstrdup(refname);27702771/* buffer for scanf result, at most refname must fit */2772 short_name =xstrdup(refname);27732774/* skip first rule, it will always match */2775for(i = nr_rules -1; i >0; --i) {2776int j;2777int rules_to_fail = i;2778int short_name_len;27792780if(1!=sscanf(refname, scanf_fmts[i], short_name))2781continue;27822783 short_name_len =strlen(short_name);27842785/*2786 * in strict mode, all (except the matched one) rules2787 * must fail to resolve to a valid non-ambiguous ref2788 */2789if(strict)2790 rules_to_fail = nr_rules;27912792/*2793 * check if the short name resolves to a valid ref,2794 * but use only rules prior to the matched one2795 */2796for(j =0; j < rules_to_fail; j++) {2797const char*rule = ref_rev_parse_rules[j];2798char refname[PATH_MAX];27992800/* skip matched rule */2801if(i == j)2802continue;28032804/*2805 * the short name is ambiguous, if it resolves2806 * (with this previous rule) to a valid ref2807 * read_ref() returns 0 on success2808 */2809mksnpath(refname,sizeof(refname),2810 rule, short_name_len, short_name);2811if(ref_exists(refname))2812break;2813}28142815/*2816 * short name is non-ambiguous if all previous rules2817 * haven't resolved to a valid ref2818 */2819if(j == rules_to_fail)2820return short_name;2821}28222823free(short_name);2824returnxstrdup(refname);2825}