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/* 815 * The submodule name, or "" for the main repo. We allocate 816 * length 1 rather than FLEX_ARRAY so that the main ref_cache 817 * is initialized correctly. 818 */ 819char name[1]; 820} ref_cache, *submodule_ref_caches; 821 822static voidclear_packed_ref_cache(struct ref_cache *refs) 823{ 824if(refs->packed) { 825free_ref_entry(refs->packed); 826 refs->packed = NULL; 827} 828} 829 830static voidclear_loose_ref_cache(struct ref_cache *refs) 831{ 832if(refs->loose) { 833free_ref_entry(refs->loose); 834 refs->loose = NULL; 835} 836} 837 838static struct ref_cache *create_ref_cache(const char*submodule) 839{ 840int len; 841struct ref_cache *refs; 842if(!submodule) 843 submodule =""; 844 len =strlen(submodule) +1; 845 refs =xcalloc(1,sizeof(struct ref_cache) + len); 846memcpy(refs->name, submodule, len); 847return refs; 848} 849 850/* 851 * Return a pointer to a ref_cache for the specified submodule. For 852 * the main repository, use submodule==NULL. The returned structure 853 * will be allocated and initialized but not necessarily populated; it 854 * should not be freed. 855 */ 856static struct ref_cache *get_ref_cache(const char*submodule) 857{ 858struct ref_cache *refs; 859 860if(!submodule || !*submodule) 861return&ref_cache; 862 863for(refs = submodule_ref_caches; refs; refs = refs->next) 864if(!strcmp(submodule, refs->name)) 865return refs; 866 867 refs =create_ref_cache(submodule); 868 refs->next = submodule_ref_caches; 869 submodule_ref_caches = refs; 870return refs; 871} 872 873voidinvalidate_ref_cache(const char*submodule) 874{ 875struct ref_cache *refs =get_ref_cache(submodule); 876clear_packed_ref_cache(refs); 877clear_loose_ref_cache(refs); 878} 879 880/* The length of a peeled reference line in packed-refs, including EOL: */ 881#define PEELED_LINE_LENGTH 42 882 883/* 884 * The packed-refs header line that we write out. Perhaps other 885 * traits will be added later. The trailing space is required. 886 */ 887static const char PACKED_REFS_HEADER[] = 888"# pack-refs with: peeled fully-peeled\n"; 889 890/* 891 * Parse one line from a packed-refs file. Write the SHA1 to sha1. 892 * Return a pointer to the refname within the line (null-terminated), 893 * or NULL if there was a problem. 894 */ 895static const char*parse_ref_line(char*line,unsigned char*sha1) 896{ 897/* 898 * 42: the answer to everything. 899 * 900 * In this case, it happens to be the answer to 901 * 40 (length of sha1 hex representation) 902 * +1 (space in between hex and name) 903 * +1 (newline at the end of the line) 904 */ 905int len =strlen(line) -42; 906 907if(len <=0) 908return NULL; 909if(get_sha1_hex(line, sha1) <0) 910return NULL; 911if(!isspace(line[40])) 912return NULL; 913 line +=41; 914if(isspace(*line)) 915return NULL; 916if(line[len] !='\n') 917return NULL; 918 line[len] =0; 919 920return line; 921} 922 923/* 924 * Read f, which is a packed-refs file, into dir. 925 * 926 * A comment line of the form "# pack-refs with: " may contain zero or 927 * more traits. We interpret the traits as follows: 928 * 929 * No traits: 930 * 931 * Probably no references are peeled. But if the file contains a 932 * peeled value for a reference, we will use it. 933 * 934 * peeled: 935 * 936 * References under "refs/tags/", if they *can* be peeled, *are* 937 * peeled in this file. References outside of "refs/tags/" are 938 * probably not peeled even if they could have been, but if we find 939 * a peeled value for such a reference we will use it. 940 * 941 * fully-peeled: 942 * 943 * All references in the file that can be peeled are peeled. 944 * Inversely (and this is more important), any references in the 945 * file for which no peeled value is recorded is not peelable. This 946 * trait should typically be written alongside "peeled" for 947 * compatibility with older clients, but we do not require it 948 * (i.e., "peeled" is a no-op if "fully-peeled" is set). 949 */ 950static voidread_packed_refs(FILE*f,struct ref_dir *dir) 951{ 952struct ref_entry *last = NULL; 953char refline[PATH_MAX]; 954enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE; 955 956while(fgets(refline,sizeof(refline), f)) { 957unsigned char sha1[20]; 958const char*refname; 959static const char header[] ="# pack-refs with:"; 960 961if(!strncmp(refline, header,sizeof(header)-1)) { 962const char*traits = refline +sizeof(header) -1; 963if(strstr(traits," fully-peeled ")) 964 peeled = PEELED_FULLY; 965else if(strstr(traits," peeled ")) 966 peeled = PEELED_TAGS; 967/* perhaps other traits later as well */ 968continue; 969} 970 971 refname =parse_ref_line(refline, sha1); 972if(refname) { 973 last =create_ref_entry(refname, sha1, REF_ISPACKED,1); 974if(peeled == PEELED_FULLY || 975(peeled == PEELED_TAGS && !prefixcmp(refname,"refs/tags/"))) 976 last->flag |= REF_KNOWS_PEELED; 977add_ref(dir, last); 978continue; 979} 980if(last && 981 refline[0] =='^'&& 982strlen(refline) == PEELED_LINE_LENGTH && 983 refline[PEELED_LINE_LENGTH -1] =='\n'&& 984!get_sha1_hex(refline +1, sha1)) { 985hashcpy(last->u.value.peeled, sha1); 986/* 987 * Regardless of what the file header said, 988 * we definitely know the value of *this* 989 * reference: 990 */ 991 last->flag |= REF_KNOWS_PEELED; 992} 993} 994} 995 996static struct ref_dir *get_packed_refs(struct ref_cache *refs) 997{ 998if(!refs->packed) { 999const char*packed_refs_file;1000FILE*f;10011002 refs->packed =create_dir_entry(refs,"",0,0);1003if(*refs->name)1004 packed_refs_file =git_path_submodule(refs->name,"packed-refs");1005else1006 packed_refs_file =git_path("packed-refs");1007 f =fopen(packed_refs_file,"r");1008if(f) {1009read_packed_refs(f,get_ref_dir(refs->packed));1010fclose(f);1011}1012}1013returnget_ref_dir(refs->packed);1014}10151016voidadd_packed_ref(const char*refname,const unsigned char*sha1)1017{1018add_ref(get_packed_refs(&ref_cache),1019create_ref_entry(refname, sha1, REF_ISPACKED,1));1020}10211022/*1023 * Read the loose references from the namespace dirname into dir1024 * (without recursing). dirname must end with '/'. dir must be the1025 * directory entry corresponding to dirname.1026 */1027static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1028{1029struct ref_cache *refs = dir->ref_cache;1030DIR*d;1031const char*path;1032struct dirent *de;1033int dirnamelen =strlen(dirname);1034struct strbuf refname;10351036if(*refs->name)1037 path =git_path_submodule(refs->name,"%s", dirname);1038else1039 path =git_path("%s", dirname);10401041 d =opendir(path);1042if(!d)1043return;10441045strbuf_init(&refname, dirnamelen +257);1046strbuf_add(&refname, dirname, dirnamelen);10471048while((de =readdir(d)) != NULL) {1049unsigned char sha1[20];1050struct stat st;1051int flag;1052const char*refdir;10531054if(de->d_name[0] =='.')1055continue;1056if(has_extension(de->d_name,".lock"))1057continue;1058strbuf_addstr(&refname, de->d_name);1059 refdir = *refs->name1060?git_path_submodule(refs->name,"%s", refname.buf)1061:git_path("%s", refname.buf);1062if(stat(refdir, &st) <0) {1063;/* silently ignore */1064}else if(S_ISDIR(st.st_mode)) {1065strbuf_addch(&refname,'/');1066add_entry_to_dir(dir,1067create_dir_entry(refs, refname.buf,1068 refname.len,1));1069}else{1070if(*refs->name) {1071hashclr(sha1);1072 flag =0;1073if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1074hashclr(sha1);1075 flag |= REF_ISBROKEN;1076}1077}else if(read_ref_full(refname.buf, sha1,1, &flag)) {1078hashclr(sha1);1079 flag |= REF_ISBROKEN;1080}1081add_entry_to_dir(dir,1082create_ref_entry(refname.buf, sha1, flag,1));1083}1084strbuf_setlen(&refname, dirnamelen);1085}1086strbuf_release(&refname);1087closedir(d);1088}10891090static struct ref_dir *get_loose_refs(struct ref_cache *refs)1091{1092if(!refs->loose) {1093/*1094 * Mark the top-level directory complete because we1095 * are about to read the only subdirectory that can1096 * hold references:1097 */1098 refs->loose =create_dir_entry(refs,"",0,0);1099/*1100 * Create an incomplete entry for "refs/":1101 */1102add_entry_to_dir(get_ref_dir(refs->loose),1103create_dir_entry(refs,"refs/",5,1));1104}1105returnget_ref_dir(refs->loose);1106}11071108/* We allow "recursive" symbolic refs. Only within reason, though */1109#define MAXDEPTH 51110#define MAXREFLEN (1024)11111112/*1113 * Called by resolve_gitlink_ref_recursive() after it failed to read1114 * from the loose refs in ref_cache refs. Find <refname> in the1115 * packed-refs file for the submodule.1116 */1117static intresolve_gitlink_packed_ref(struct ref_cache *refs,1118const char*refname,unsigned char*sha1)1119{1120struct ref_entry *ref;1121struct ref_dir *dir =get_packed_refs(refs);11221123 ref =find_ref(dir, refname);1124if(ref == NULL)1125return-1;11261127memcpy(sha1, ref->u.value.sha1,20);1128return0;1129}11301131static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1132const char*refname,unsigned char*sha1,1133int recursion)1134{1135int fd, len;1136char buffer[128], *p;1137char*path;11381139if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1140return-1;1141 path = *refs->name1142?git_path_submodule(refs->name,"%s", refname)1143:git_path("%s", refname);1144 fd =open(path, O_RDONLY);1145if(fd <0)1146returnresolve_gitlink_packed_ref(refs, refname, sha1);11471148 len =read(fd, buffer,sizeof(buffer)-1);1149close(fd);1150if(len <0)1151return-1;1152while(len &&isspace(buffer[len-1]))1153 len--;1154 buffer[len] =0;11551156/* Was it a detached head or an old-fashioned symlink? */1157if(!get_sha1_hex(buffer, sha1))1158return0;11591160/* Symref? */1161if(strncmp(buffer,"ref:",4))1162return-1;1163 p = buffer +4;1164while(isspace(*p))1165 p++;11661167returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1168}11691170intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1171{1172int len =strlen(path), retval;1173char*submodule;1174struct ref_cache *refs;11751176while(len && path[len-1] =='/')1177 len--;1178if(!len)1179return-1;1180 submodule =xstrndup(path, len);1181 refs =get_ref_cache(submodule);1182free(submodule);11831184 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1185return retval;1186}11871188/*1189 * Return the ref_entry for the given refname from the packed1190 * references. If it does not exist, return NULL.1191 */1192static struct ref_entry *get_packed_ref(const char*refname)1193{1194returnfind_ref(get_packed_refs(&ref_cache), refname);1195}11961197const char*resolve_ref_unsafe(const char*refname,unsigned char*sha1,int reading,int*flag)1198{1199int depth = MAXDEPTH;1200 ssize_t len;1201char buffer[256];1202static char refname_buffer[256];12031204if(flag)1205*flag =0;12061207if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1208return NULL;12091210for(;;) {1211char path[PATH_MAX];1212struct stat st;1213char*buf;1214int fd;12151216if(--depth <0)1217return NULL;12181219git_snpath(path,sizeof(path),"%s", refname);12201221if(lstat(path, &st) <0) {1222struct ref_entry *entry;12231224if(errno != ENOENT)1225return NULL;1226/*1227 * The loose reference file does not exist;1228 * check for a packed reference.1229 */1230 entry =get_packed_ref(refname);1231if(entry) {1232hashcpy(sha1, entry->u.value.sha1);1233if(flag)1234*flag |= REF_ISPACKED;1235return refname;1236}1237/* The reference is not a packed reference, either. */1238if(reading) {1239return NULL;1240}else{1241hashclr(sha1);1242return refname;1243}1244}12451246/* Follow "normalized" - ie "refs/.." symlinks by hand */1247if(S_ISLNK(st.st_mode)) {1248 len =readlink(path, buffer,sizeof(buffer)-1);1249if(len <0)1250return NULL;1251 buffer[len] =0;1252if(!prefixcmp(buffer,"refs/") &&1253!check_refname_format(buffer,0)) {1254strcpy(refname_buffer, buffer);1255 refname = refname_buffer;1256if(flag)1257*flag |= REF_ISSYMREF;1258continue;1259}1260}12611262/* Is it a directory? */1263if(S_ISDIR(st.st_mode)) {1264 errno = EISDIR;1265return NULL;1266}12671268/*1269 * Anything else, just open it and try to use it as1270 * a ref1271 */1272 fd =open(path, O_RDONLY);1273if(fd <0)1274return NULL;1275 len =read_in_full(fd, buffer,sizeof(buffer)-1);1276close(fd);1277if(len <0)1278return NULL;1279while(len &&isspace(buffer[len-1]))1280 len--;1281 buffer[len] ='\0';12821283/*1284 * Is it a symbolic ref?1285 */1286if(prefixcmp(buffer,"ref:"))1287break;1288if(flag)1289*flag |= REF_ISSYMREF;1290 buf = buffer +4;1291while(isspace(*buf))1292 buf++;1293if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1294if(flag)1295*flag |= REF_ISBROKEN;1296return NULL;1297}1298 refname =strcpy(refname_buffer, buf);1299}1300/* Please note that FETCH_HEAD has a second line containing other data. */1301if(get_sha1_hex(buffer, sha1) || (buffer[40] !='\0'&& !isspace(buffer[40]))) {1302if(flag)1303*flag |= REF_ISBROKEN;1304return NULL;1305}1306return refname;1307}13081309char*resolve_refdup(const char*ref,unsigned char*sha1,int reading,int*flag)1310{1311const char*ret =resolve_ref_unsafe(ref, sha1, reading, flag);1312return ret ?xstrdup(ret) : NULL;1313}13141315/* The argument to filter_refs */1316struct ref_filter {1317const char*pattern;1318 each_ref_fn *fn;1319void*cb_data;1320};13211322intread_ref_full(const char*refname,unsigned char*sha1,int reading,int*flags)1323{1324if(resolve_ref_unsafe(refname, sha1, reading, flags))1325return0;1326return-1;1327}13281329intread_ref(const char*refname,unsigned char*sha1)1330{1331returnread_ref_full(refname, sha1,1, NULL);1332}13331334intref_exists(const char*refname)1335{1336unsigned char sha1[20];1337return!!resolve_ref_unsafe(refname, sha1,1, NULL);1338}13391340static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1341void*data)1342{1343struct ref_filter *filter = (struct ref_filter *)data;1344if(fnmatch(filter->pattern, refname,0))1345return0;1346return filter->fn(refname, sha1, flags, filter->cb_data);1347}13481349enum peel_status {1350/* object was peeled successfully: */1351 PEEL_PEELED =0,13521353/*1354 * object cannot be peeled because the named object (or an1355 * object referred to by a tag in the peel chain), does not1356 * exist.1357 */1358 PEEL_INVALID = -1,13591360/* object cannot be peeled because it is not a tag: */1361 PEEL_NON_TAG = -2,13621363/* ref_entry contains no peeled value because it is a symref: */1364 PEEL_IS_SYMREF = -3,13651366/*1367 * ref_entry cannot be peeled because it is broken (i.e., the1368 * symbolic reference cannot even be resolved to an object1369 * name):1370 */1371 PEEL_BROKEN = -41372};13731374/*1375 * Peel the named object; i.e., if the object is a tag, resolve the1376 * tag recursively until a non-tag is found. If successful, store the1377 * result to sha1 and return PEEL_PEELED. If the object is not a tag1378 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1379 * and leave sha1 unchanged.1380 */1381static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1382{1383struct object *o =lookup_unknown_object(name);13841385if(o->type == OBJ_NONE) {1386int type =sha1_object_info(name, NULL);1387if(type <0)1388return PEEL_INVALID;1389 o->type = type;1390}13911392if(o->type != OBJ_TAG)1393return PEEL_NON_TAG;13941395 o =deref_tag_noverify(o);1396if(!o)1397return PEEL_INVALID;13981399hashcpy(sha1, o->sha1);1400return PEEL_PEELED;1401}14021403/*1404 * Peel the entry (if possible) and return its new peel_status. If1405 * repeel is true, re-peel the entry even if there is an old peeled1406 * value that is already stored in it.1407 *1408 * It is OK to call this function with a packed reference entry that1409 * might be stale and might even refer to an object that has since1410 * been garbage-collected. In such a case, if the entry has1411 * REF_KNOWS_PEELED then leave the status unchanged and return1412 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1413 */1414static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1415{1416enum peel_status status;14171418if(entry->flag & REF_KNOWS_PEELED) {1419if(repeel) {1420 entry->flag &= ~REF_KNOWS_PEELED;1421hashclr(entry->u.value.peeled);1422}else{1423returnis_null_sha1(entry->u.value.peeled) ?1424 PEEL_NON_TAG : PEEL_PEELED;1425}1426}1427if(entry->flag & REF_ISBROKEN)1428return PEEL_BROKEN;1429if(entry->flag & REF_ISSYMREF)1430return PEEL_IS_SYMREF;14311432 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1433if(status == PEEL_PEELED || status == PEEL_NON_TAG)1434 entry->flag |= REF_KNOWS_PEELED;1435return status;1436}14371438intpeel_ref(const char*refname,unsigned char*sha1)1439{1440int flag;1441unsigned char base[20];14421443if(current_ref && (current_ref->name == refname1444|| !strcmp(current_ref->name, refname))) {1445if(peel_entry(current_ref,0))1446return-1;1447hashcpy(sha1, current_ref->u.value.peeled);1448return0;1449}14501451if(read_ref_full(refname, base,1, &flag))1452return-1;14531454/*1455 * If the reference is packed, read its ref_entry from the1456 * cache in the hope that we already know its peeled value.1457 * We only try this optimization on packed references because1458 * (a) forcing the filling of the loose reference cache could1459 * be expensive and (b) loose references anyway usually do not1460 * have REF_KNOWS_PEELED.1461 */1462if(flag & REF_ISPACKED) {1463struct ref_entry *r =get_packed_ref(refname);1464if(r) {1465if(peel_entry(r,0))1466return-1;1467hashcpy(sha1, r->u.value.peeled);1468return0;1469}1470}14711472returnpeel_object(base, sha1);1473}14741475struct warn_if_dangling_data {1476FILE*fp;1477const char*refname;1478const char*msg_fmt;1479};14801481static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1482int flags,void*cb_data)1483{1484struct warn_if_dangling_data *d = cb_data;1485const char*resolves_to;1486unsigned char junk[20];14871488if(!(flags & REF_ISSYMREF))1489return0;14901491 resolves_to =resolve_ref_unsafe(refname, junk,0, NULL);1492if(!resolves_to ||strcmp(resolves_to, d->refname))1493return0;14941495fprintf(d->fp, d->msg_fmt, refname);1496fputc('\n', d->fp);1497return0;1498}14991500voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1501{1502struct warn_if_dangling_data data;15031504 data.fp = fp;1505 data.refname = refname;1506 data.msg_fmt = msg_fmt;1507for_each_rawref(warn_if_dangling_symref, &data);1508}15091510/*1511 * Call fn for each reference in the specified ref_cache, omitting1512 * references not in the containing_dir of base. fn is called for all1513 * references, including broken ones. If fn ever returns a non-zero1514 * value, stop the iteration and return that value; otherwise, return1515 * 0.1516 */1517static intdo_for_each_entry(struct ref_cache *refs,const char*base,1518 each_ref_entry_fn fn,void*cb_data)1519{1520struct ref_dir *packed_dir =get_packed_refs(refs);1521struct ref_dir *loose_dir =get_loose_refs(refs);1522int retval =0;15231524if(base && *base) {1525 packed_dir =find_containing_dir(packed_dir, base,0);1526 loose_dir =find_containing_dir(loose_dir, base,0);1527}15281529if(packed_dir && loose_dir) {1530sort_ref_dir(packed_dir);1531sort_ref_dir(loose_dir);1532 retval =do_for_each_entry_in_dirs(1533 packed_dir, loose_dir, fn, cb_data);1534}else if(packed_dir) {1535sort_ref_dir(packed_dir);1536 retval =do_for_each_entry_in_dir(1537 packed_dir,0, fn, cb_data);1538}else if(loose_dir) {1539sort_ref_dir(loose_dir);1540 retval =do_for_each_entry_in_dir(1541 loose_dir,0, fn, cb_data);1542}15431544return retval;1545}15461547/*1548 * Call fn for each reference in the specified ref_cache for which the1549 * refname begins with base. If trim is non-zero, then trim that many1550 * characters off the beginning of each refname before passing the1551 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1552 * broken references in the iteration. If fn ever returns a non-zero1553 * value, stop the iteration and return that value; otherwise, return1554 * 0.1555 */1556static intdo_for_each_ref(struct ref_cache *refs,const char*base,1557 each_ref_fn fn,int trim,int flags,void*cb_data)1558{1559struct ref_entry_cb data;1560 data.base = base;1561 data.trim = trim;1562 data.flags = flags;1563 data.fn = fn;1564 data.cb_data = cb_data;15651566returndo_for_each_entry(refs, base, do_one_ref, &data);1567}15681569static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1570{1571unsigned char sha1[20];1572int flag;15731574if(submodule) {1575if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1576returnfn("HEAD", sha1,0, cb_data);15771578return0;1579}15801581if(!read_ref_full("HEAD", sha1,1, &flag))1582returnfn("HEAD", sha1, flag, cb_data);15831584return0;1585}15861587inthead_ref(each_ref_fn fn,void*cb_data)1588{1589returndo_head_ref(NULL, fn, cb_data);1590}15911592inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1593{1594returndo_head_ref(submodule, fn, cb_data);1595}15961597intfor_each_ref(each_ref_fn fn,void*cb_data)1598{1599returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1600}16011602intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1603{1604returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1605}16061607intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1608{1609returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);1610}16111612intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1613 each_ref_fn fn,void*cb_data)1614{1615returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);1616}16171618intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1619{1620returnfor_each_ref_in("refs/tags/", fn, cb_data);1621}16221623intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1624{1625returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1626}16271628intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1629{1630returnfor_each_ref_in("refs/heads/", fn, cb_data);1631}16321633intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1634{1635returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);1636}16371638intfor_each_remote_ref(each_ref_fn fn,void*cb_data)1639{1640returnfor_each_ref_in("refs/remotes/", fn, cb_data);1641}16421643intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1644{1645returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);1646}16471648intfor_each_replace_ref(each_ref_fn fn,void*cb_data)1649{1650returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);1651}16521653inthead_ref_namespaced(each_ref_fn fn,void*cb_data)1654{1655struct strbuf buf = STRBUF_INIT;1656int ret =0;1657unsigned char sha1[20];1658int flag;16591660strbuf_addf(&buf,"%sHEAD",get_git_namespace());1661if(!read_ref_full(buf.buf, sha1,1, &flag))1662 ret =fn(buf.buf, sha1, flag, cb_data);1663strbuf_release(&buf);16641665return ret;1666}16671668intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)1669{1670struct strbuf buf = STRBUF_INIT;1671int ret;1672strbuf_addf(&buf,"%srefs/",get_git_namespace());1673 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);1674strbuf_release(&buf);1675return ret;1676}16771678intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,1679const char*prefix,void*cb_data)1680{1681struct strbuf real_pattern = STRBUF_INIT;1682struct ref_filter filter;1683int ret;16841685if(!prefix &&prefixcmp(pattern,"refs/"))1686strbuf_addstr(&real_pattern,"refs/");1687else if(prefix)1688strbuf_addstr(&real_pattern, prefix);1689strbuf_addstr(&real_pattern, pattern);16901691if(!has_glob_specials(pattern)) {1692/* Append implied '/' '*' if not present. */1693if(real_pattern.buf[real_pattern.len -1] !='/')1694strbuf_addch(&real_pattern,'/');1695/* No need to check for '*', there is none. */1696strbuf_addch(&real_pattern,'*');1697}16981699 filter.pattern = real_pattern.buf;1700 filter.fn = fn;1701 filter.cb_data = cb_data;1702 ret =for_each_ref(filter_refs, &filter);17031704strbuf_release(&real_pattern);1705return ret;1706}17071708intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)1709{1710returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);1711}17121713intfor_each_rawref(each_ref_fn fn,void*cb_data)1714{1715returndo_for_each_ref(&ref_cache,"", fn,0,1716 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);1717}17181719const char*prettify_refname(const char*name)1720{1721return name + (1722!prefixcmp(name,"refs/heads/") ?11:1723!prefixcmp(name,"refs/tags/") ?10:1724!prefixcmp(name,"refs/remotes/") ?13:17250);1726}17271728const char*ref_rev_parse_rules[] = {1729"%.*s",1730"refs/%.*s",1731"refs/tags/%.*s",1732"refs/heads/%.*s",1733"refs/remotes/%.*s",1734"refs/remotes/%.*s/HEAD",1735 NULL1736};17371738intrefname_match(const char*abbrev_name,const char*full_name,const char**rules)1739{1740const char**p;1741const int abbrev_name_len =strlen(abbrev_name);17421743for(p = rules; *p; p++) {1744if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {1745return1;1746}1747}17481749return0;1750}17511752static struct ref_lock *verify_lock(struct ref_lock *lock,1753const unsigned char*old_sha1,int mustexist)1754{1755if(read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {1756error("Can't verify ref%s", lock->ref_name);1757unlock_ref(lock);1758return NULL;1759}1760if(hashcmp(lock->old_sha1, old_sha1)) {1761error("Ref%sis at%sbut expected%s", lock->ref_name,1762sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));1763unlock_ref(lock);1764return NULL;1765}1766return lock;1767}17681769static intremove_empty_directories(const char*file)1770{1771/* we want to create a file but there is a directory there;1772 * if that is an empty directory (or a directory that contains1773 * only empty directories), remove them.1774 */1775struct strbuf path;1776int result;17771778strbuf_init(&path,20);1779strbuf_addstr(&path, file);17801781 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);17821783strbuf_release(&path);17841785return result;1786}17871788/*1789 * *string and *len will only be substituted, and *string returned (for1790 * later free()ing) if the string passed in is a magic short-hand form1791 * to name a branch.1792 */1793static char*substitute_branch_name(const char**string,int*len)1794{1795struct strbuf buf = STRBUF_INIT;1796int ret =interpret_branch_name(*string, &buf);17971798if(ret == *len) {1799size_t size;1800*string =strbuf_detach(&buf, &size);1801*len = size;1802return(char*)*string;1803}18041805return NULL;1806}18071808intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)1809{1810char*last_branch =substitute_branch_name(&str, &len);1811const char**p, *r;1812int refs_found =0;18131814*ref = NULL;1815for(p = ref_rev_parse_rules; *p; p++) {1816char fullref[PATH_MAX];1817unsigned char sha1_from_ref[20];1818unsigned char*this_result;1819int flag;18201821 this_result = refs_found ? sha1_from_ref : sha1;1822mksnpath(fullref,sizeof(fullref), *p, len, str);1823 r =resolve_ref_unsafe(fullref, this_result,1, &flag);1824if(r) {1825if(!refs_found++)1826*ref =xstrdup(r);1827if(!warn_ambiguous_refs)1828break;1829}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {1830warning("ignoring dangling symref%s.", fullref);1831}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {1832warning("ignoring broken ref%s.", fullref);1833}1834}1835free(last_branch);1836return refs_found;1837}18381839intdwim_log(const char*str,int len,unsigned char*sha1,char**log)1840{1841char*last_branch =substitute_branch_name(&str, &len);1842const char**p;1843int logs_found =0;18441845*log = NULL;1846for(p = ref_rev_parse_rules; *p; p++) {1847struct stat st;1848unsigned char hash[20];1849char path[PATH_MAX];1850const char*ref, *it;18511852mksnpath(path,sizeof(path), *p, len, str);1853 ref =resolve_ref_unsafe(path, hash,1, NULL);1854if(!ref)1855continue;1856if(!stat(git_path("logs/%s", path), &st) &&1857S_ISREG(st.st_mode))1858 it = path;1859else if(strcmp(ref, path) &&1860!stat(git_path("logs/%s", ref), &st) &&1861S_ISREG(st.st_mode))1862 it = ref;1863else1864continue;1865if(!logs_found++) {1866*log =xstrdup(it);1867hashcpy(sha1, hash);1868}1869if(!warn_ambiguous_refs)1870break;1871}1872free(last_branch);1873return logs_found;1874}18751876static struct ref_lock *lock_ref_sha1_basic(const char*refname,1877const unsigned char*old_sha1,1878int flags,int*type_p)1879{1880char*ref_file;1881const char*orig_refname = refname;1882struct ref_lock *lock;1883int last_errno =0;1884int type, lflags;1885int mustexist = (old_sha1 && !is_null_sha1(old_sha1));1886int missing =0;18871888 lock =xcalloc(1,sizeof(struct ref_lock));1889 lock->lock_fd = -1;18901891 refname =resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);1892if(!refname && errno == EISDIR) {1893/* we are trying to lock foo but we used to1894 * have foo/bar which now does not exist;1895 * it is normal for the empty directory 'foo'1896 * to remain.1897 */1898 ref_file =git_path("%s", orig_refname);1899if(remove_empty_directories(ref_file)) {1900 last_errno = errno;1901error("there are still refs under '%s'", orig_refname);1902goto error_return;1903}1904 refname =resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);1905}1906if(type_p)1907*type_p = type;1908if(!refname) {1909 last_errno = errno;1910error("unable to resolve reference%s:%s",1911 orig_refname,strerror(errno));1912goto error_return;1913}1914 missing =is_null_sha1(lock->old_sha1);1915/* When the ref did not exist and we are creating it,1916 * make sure there is no existing ref that is packed1917 * whose name begins with our refname, nor a ref whose1918 * name is a proper prefix of our refname.1919 */1920if(missing &&1921!is_refname_available(refname, NULL,get_packed_refs(&ref_cache))) {1922 last_errno = ENOTDIR;1923goto error_return;1924}19251926 lock->lk =xcalloc(1,sizeof(struct lock_file));19271928 lflags = LOCK_DIE_ON_ERROR;1929if(flags & REF_NODEREF) {1930 refname = orig_refname;1931 lflags |= LOCK_NODEREF;1932}1933 lock->ref_name =xstrdup(refname);1934 lock->orig_ref_name =xstrdup(orig_refname);1935 ref_file =git_path("%s", refname);1936if(missing)1937 lock->force_write =1;1938if((flags & REF_NODEREF) && (type & REF_ISSYMREF))1939 lock->force_write =1;19401941if(safe_create_leading_directories(ref_file)) {1942 last_errno = errno;1943error("unable to create directory for%s", ref_file);1944goto error_return;1945}19461947 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);1948return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;19491950 error_return:1951unlock_ref(lock);1952 errno = last_errno;1953return NULL;1954}19551956struct ref_lock *lock_ref_sha1(const char*refname,const unsigned char*old_sha1)1957{1958char refpath[PATH_MAX];1959if(check_refname_format(refname,0))1960return NULL;1961strcpy(refpath,mkpath("refs/%s", refname));1962returnlock_ref_sha1_basic(refpath, old_sha1,0, NULL);1963}19641965struct ref_lock *lock_any_ref_for_update(const char*refname,1966const unsigned char*old_sha1,int flags)1967{1968if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1969return NULL;1970returnlock_ref_sha1_basic(refname, old_sha1, flags, NULL);1971}19721973/*1974 * Write an entry to the packed-refs file for the specified refname.1975 * If peeled is non-NULL, write it as the entry's peeled value.1976 */1977static voidwrite_packed_entry(int fd,char*refname,unsigned char*sha1,1978unsigned char*peeled)1979{1980char line[PATH_MAX +100];1981int len;19821983 len =snprintf(line,sizeof(line),"%s %s\n",1984sha1_to_hex(sha1), refname);1985/* this should not happen but just being defensive */1986if(len >sizeof(line))1987die("too long a refname '%s'", refname);1988write_or_die(fd, line, len);19891990if(peeled) {1991if(snprintf(line,sizeof(line),"^%s\n",1992sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)1993die("internal error");1994write_or_die(fd, line, PEELED_LINE_LENGTH);1995}1996}19971998struct ref_to_prune {1999struct ref_to_prune *next;2000unsigned char sha1[20];2001char name[FLEX_ARRAY];2002};20032004struct pack_refs_cb_data {2005unsigned int flags;2006struct ref_to_prune *ref_to_prune;2007int fd;2008};20092010static intpack_one_ref(struct ref_entry *entry,void*cb_data)2011{2012struct pack_refs_cb_data *cb = cb_data;2013enum peel_status peel_status;2014int is_tag_ref = !prefixcmp(entry->name,"refs/tags/");20152016/* ALWAYS pack refs that were already packed or are tags */2017if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref &&2018!(entry->flag & REF_ISPACKED))2019return0;20202021/* Do not pack symbolic or broken refs: */2022if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2023return0;20242025 peel_status =peel_entry(entry,1);2026if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2027die("internal error peeling reference%s(%s)",2028 entry->name,sha1_to_hex(entry->u.value.sha1));2029write_packed_entry(cb->fd, entry->name, entry->u.value.sha1,2030 peel_status == PEEL_PEELED ?2031 entry->u.value.peeled : NULL);20322033/* If the ref was already packed, there is no need to prune it. */2034if((cb->flags & PACK_REFS_PRUNE) && !(entry->flag & REF_ISPACKED)) {2035int namelen =strlen(entry->name) +1;2036struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2037hashcpy(n->sha1, entry->u.value.sha1);2038strcpy(n->name, entry->name);2039 n->next = cb->ref_to_prune;2040 cb->ref_to_prune = n;2041}2042return0;2043}20442045/*2046 * Remove empty parents, but spare refs/ and immediate subdirs.2047 * Note: munges *name.2048 */2049static voidtry_remove_empty_parents(char*name)2050{2051char*p, *q;2052int i;2053 p = name;2054for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2055while(*p && *p !='/')2056 p++;2057/* tolerate duplicate slashes; see check_refname_format() */2058while(*p =='/')2059 p++;2060}2061for(q = p; *q; q++)2062;2063while(1) {2064while(q > p && *q !='/')2065 q--;2066while(q > p && *(q-1) =='/')2067 q--;2068if(q == p)2069break;2070*q ='\0';2071if(rmdir(git_path("%s", name)))2072break;2073}2074}20752076/* make sure nobody touched the ref, and unlink */2077static voidprune_ref(struct ref_to_prune *r)2078{2079struct ref_lock *lock =lock_ref_sha1(r->name +5, r->sha1);20802081if(lock) {2082unlink_or_warn(git_path("%s", r->name));2083unlock_ref(lock);2084try_remove_empty_parents(r->name);2085}2086}20872088static voidprune_refs(struct ref_to_prune *r)2089{2090while(r) {2091prune_ref(r);2092 r = r->next;2093}2094}20952096static struct lock_file packlock;20972098intpack_refs(unsigned int flags)2099{2100struct pack_refs_cb_data cbdata;21012102memset(&cbdata,0,sizeof(cbdata));2103 cbdata.flags = flags;21042105 cbdata.fd =hold_lock_file_for_update(&packlock,git_path("packed-refs"),2106 LOCK_DIE_ON_ERROR);21072108write_or_die(cbdata.fd, PACKED_REFS_HEADER,strlen(PACKED_REFS_HEADER));21092110do_for_each_entry(&ref_cache,"", pack_one_ref, &cbdata);2111if(commit_lock_file(&packlock) <0)2112die_errno("unable to overwrite old ref-pack file");2113prune_refs(cbdata.ref_to_prune);2114return0;2115}21162117static intrepack_ref_fn(struct ref_entry *entry,void*cb_data)2118{2119int*fd = cb_data;2120enum peel_status peel_status;21212122if(entry->flag & REF_ISBROKEN) {2123/* This shouldn't happen to packed refs. */2124error("%sis broken!", entry->name);2125return0;2126}2127if(!has_sha1_file(entry->u.value.sha1)) {2128unsigned char sha1[20];2129int flags;21302131if(read_ref_full(entry->name, sha1,0, &flags))2132/* We should at least have found the packed ref. */2133die("Internal error");2134if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED))2135/*2136 * This packed reference is overridden by a2137 * loose reference, so it is OK that its value2138 * is no longer valid; for example, it might2139 * refer to an object that has been garbage2140 * collected. For this purpose we don't even2141 * care whether the loose reference itself is2142 * invalid, broken, symbolic, etc. Silently2143 * omit the packed reference from the output.2144 */2145return0;2146/*2147 * There is no overriding loose reference, so the fact2148 * that this reference doesn't refer to a valid object2149 * indicates some kind of repository corruption.2150 * Report the problem, then omit the reference from2151 * the output.2152 */2153error("%sdoes not point to a valid object!", entry->name);2154return0;2155}21562157 peel_status =peel_entry(entry,0);2158write_packed_entry(*fd, entry->name, entry->u.value.sha1,2159 peel_status == PEEL_PEELED ?2160 entry->u.value.peeled : NULL);21612162return0;2163}21642165static intrepack_without_ref(const char*refname)2166{2167int fd;2168struct ref_dir *packed;21692170if(!get_packed_ref(refname))2171return0;/* refname does not exist in packed refs */21722173 fd =hold_lock_file_for_update(&packlock,git_path("packed-refs"),0);2174if(fd <0) {2175unable_to_lock_error(git_path("packed-refs"), errno);2176returnerror("cannot delete '%s' from packed refs", refname);2177}2178clear_packed_ref_cache(&ref_cache);2179 packed =get_packed_refs(&ref_cache);2180/* Remove refname from the cache. */2181if(remove_entry(packed, refname) == -1) {2182/*2183 * The packed entry disappeared while we were2184 * acquiring the lock.2185 */2186rollback_lock_file(&packlock);2187return0;2188}2189write_or_die(fd, PACKED_REFS_HEADER,strlen(PACKED_REFS_HEADER));2190do_for_each_entry_in_dir(packed,0, repack_ref_fn, &fd);2191returncommit_lock_file(&packlock);2192}21932194intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2195{2196struct ref_lock *lock;2197int err, i =0, ret =0, flag =0;21982199 lock =lock_ref_sha1_basic(refname, sha1, delopt, &flag);2200if(!lock)2201return1;2202if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2203/* loose */2204 i =strlen(lock->lk->filename) -5;/* .lock */2205 lock->lk->filename[i] =0;2206 err =unlink_or_warn(lock->lk->filename);2207if(err && errno != ENOENT)2208 ret =1;22092210 lock->lk->filename[i] ='.';2211}2212/* removing the loose one could have resurrected an earlier2213 * packed one. Also, if it was not loose we need to repack2214 * without it.2215 */2216 ret |=repack_without_ref(lock->ref_name);22172218unlink_or_warn(git_path("logs/%s", lock->ref_name));2219clear_loose_ref_cache(&ref_cache);2220unlock_ref(lock);2221return ret;2222}22232224/*2225 * People using contrib's git-new-workdir have .git/logs/refs ->2226 * /some/other/path/.git/logs/refs, and that may live on another device.2227 *2228 * IOW, to avoid cross device rename errors, the temporary renamed log must2229 * live into logs/refs.2230 */2231#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"22322233intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2234{2235unsigned char sha1[20], orig_sha1[20];2236int flag =0, logmoved =0;2237struct ref_lock *lock;2238struct stat loginfo;2239int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2240const char*symref = NULL;22412242if(log &&S_ISLNK(loginfo.st_mode))2243returnerror("reflog for%sis a symlink", oldrefname);22442245 symref =resolve_ref_unsafe(oldrefname, orig_sha1,1, &flag);2246if(flag & REF_ISSYMREF)2247returnerror("refname%sis a symbolic ref, renaming it is not supported",2248 oldrefname);2249if(!symref)2250returnerror("refname%snot found", oldrefname);22512252if(!is_refname_available(newrefname, oldrefname,get_packed_refs(&ref_cache)))2253return1;22542255if(!is_refname_available(newrefname, oldrefname,get_loose_refs(&ref_cache)))2256return1;22572258if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2259returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2260 oldrefname,strerror(errno));22612262if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2263error("unable to delete old%s", oldrefname);2264goto rollback;2265}22662267if(!read_ref_full(newrefname, sha1,1, &flag) &&2268delete_ref(newrefname, sha1, REF_NODEREF)) {2269if(errno==EISDIR) {2270if(remove_empty_directories(git_path("%s", newrefname))) {2271error("Directory not empty:%s", newrefname);2272goto rollback;2273}2274}else{2275error("unable to delete existing%s", newrefname);2276goto rollback;2277}2278}22792280if(log &&safe_create_leading_directories(git_path("logs/%s", newrefname))) {2281error("unable to create directory for%s", newrefname);2282goto rollback;2283}22842285 retry:2286if(log &&rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2287if(errno==EISDIR || errno==ENOTDIR) {2288/*2289 * rename(a, b) when b is an existing2290 * directory ought to result in ISDIR, but2291 * Solaris 5.8 gives ENOTDIR. Sheesh.2292 */2293if(remove_empty_directories(git_path("logs/%s", newrefname))) {2294error("Directory not empty: logs/%s", newrefname);2295goto rollback;2296}2297goto retry;2298}else{2299error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2300 newrefname,strerror(errno));2301goto rollback;2302}2303}2304 logmoved = log;23052306 lock =lock_ref_sha1_basic(newrefname, NULL,0, NULL);2307if(!lock) {2308error("unable to lock%sfor update", newrefname);2309goto rollback;2310}2311 lock->force_write =1;2312hashcpy(lock->old_sha1, orig_sha1);2313if(write_ref_sha1(lock, orig_sha1, logmsg)) {2314error("unable to write current sha1 into%s", newrefname);2315goto rollback;2316}23172318return0;23192320 rollback:2321 lock =lock_ref_sha1_basic(oldrefname, NULL,0, NULL);2322if(!lock) {2323error("unable to lock%sfor rollback", oldrefname);2324goto rollbacklog;2325}23262327 lock->force_write =1;2328 flag = log_all_ref_updates;2329 log_all_ref_updates =0;2330if(write_ref_sha1(lock, orig_sha1, NULL))2331error("unable to write current sha1 into%s", oldrefname);2332 log_all_ref_updates = flag;23332334 rollbacklog:2335if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2336error("unable to restore logfile%sfrom%s:%s",2337 oldrefname, newrefname,strerror(errno));2338if(!logmoved && log &&2339rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2340error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2341 oldrefname,strerror(errno));23422343return1;2344}23452346intclose_ref(struct ref_lock *lock)2347{2348if(close_lock_file(lock->lk))2349return-1;2350 lock->lock_fd = -1;2351return0;2352}23532354intcommit_ref(struct ref_lock *lock)2355{2356if(commit_lock_file(lock->lk))2357return-1;2358 lock->lock_fd = -1;2359return0;2360}23612362voidunlock_ref(struct ref_lock *lock)2363{2364/* Do not free lock->lk -- atexit() still looks at them */2365if(lock->lk)2366rollback_lock_file(lock->lk);2367free(lock->ref_name);2368free(lock->orig_ref_name);2369free(lock);2370}23712372/*2373 * copy the reflog message msg to buf, which has been allocated sufficiently2374 * large, while cleaning up the whitespaces. Especially, convert LF to space,2375 * because reflog file is one line per entry.2376 */2377static intcopy_msg(char*buf,const char*msg)2378{2379char*cp = buf;2380char c;2381int wasspace =1;23822383*cp++ ='\t';2384while((c = *msg++)) {2385if(wasspace &&isspace(c))2386continue;2387 wasspace =isspace(c);2388if(wasspace)2389 c =' ';2390*cp++ = c;2391}2392while(buf < cp &&isspace(cp[-1]))2393 cp--;2394*cp++ ='\n';2395return cp - buf;2396}23972398intlog_ref_setup(const char*refname,char*logfile,int bufsize)2399{2400int logfd, oflags = O_APPEND | O_WRONLY;24012402git_snpath(logfile, bufsize,"logs/%s", refname);2403if(log_all_ref_updates &&2404(!prefixcmp(refname,"refs/heads/") ||2405!prefixcmp(refname,"refs/remotes/") ||2406!prefixcmp(refname,"refs/notes/") ||2407!strcmp(refname,"HEAD"))) {2408if(safe_create_leading_directories(logfile) <0)2409returnerror("unable to create directory for%s",2410 logfile);2411 oflags |= O_CREAT;2412}24132414 logfd =open(logfile, oflags,0666);2415if(logfd <0) {2416if(!(oflags & O_CREAT) && errno == ENOENT)2417return0;24182419if((oflags & O_CREAT) && errno == EISDIR) {2420if(remove_empty_directories(logfile)) {2421returnerror("There are still logs under '%s'",2422 logfile);2423}2424 logfd =open(logfile, oflags,0666);2425}24262427if(logfd <0)2428returnerror("Unable to append to%s:%s",2429 logfile,strerror(errno));2430}24312432adjust_shared_perm(logfile);2433close(logfd);2434return0;2435}24362437static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2438const unsigned char*new_sha1,const char*msg)2439{2440int logfd, result, written, oflags = O_APPEND | O_WRONLY;2441unsigned maxlen, len;2442int msglen;2443char log_file[PATH_MAX];2444char*logrec;2445const char*committer;24462447if(log_all_ref_updates <0)2448 log_all_ref_updates = !is_bare_repository();24492450 result =log_ref_setup(refname, log_file,sizeof(log_file));2451if(result)2452return result;24532454 logfd =open(log_file, oflags);2455if(logfd <0)2456return0;2457 msglen = msg ?strlen(msg) :0;2458 committer =git_committer_info(0);2459 maxlen =strlen(committer) + msglen +100;2460 logrec =xmalloc(maxlen);2461 len =sprintf(logrec,"%s %s %s\n",2462sha1_to_hex(old_sha1),2463sha1_to_hex(new_sha1),2464 committer);2465if(msglen)2466 len +=copy_msg(logrec + len -1, msg) -1;2467 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;2468free(logrec);2469if(close(logfd) !=0|| written != len)2470returnerror("Unable to append to%s", log_file);2471return0;2472}24732474static intis_branch(const char*refname)2475{2476return!strcmp(refname,"HEAD") || !prefixcmp(refname,"refs/heads/");2477}24782479intwrite_ref_sha1(struct ref_lock *lock,2480const unsigned char*sha1,const char*logmsg)2481{2482static char term ='\n';2483struct object *o;24842485if(!lock)2486return-1;2487if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {2488unlock_ref(lock);2489return0;2490}2491 o =parse_object(sha1);2492if(!o) {2493error("Trying to write ref%swith nonexistent object%s",2494 lock->ref_name,sha1_to_hex(sha1));2495unlock_ref(lock);2496return-1;2497}2498if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {2499error("Trying to write non-commit object%sto branch%s",2500sha1_to_hex(sha1), lock->ref_name);2501unlock_ref(lock);2502return-1;2503}2504if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||2505write_in_full(lock->lock_fd, &term,1) !=12506||close_ref(lock) <0) {2507error("Couldn't write%s", lock->lk->filename);2508unlock_ref(lock);2509return-1;2510}2511clear_loose_ref_cache(&ref_cache);2512if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||2513(strcmp(lock->ref_name, lock->orig_ref_name) &&2514log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {2515unlock_ref(lock);2516return-1;2517}2518if(strcmp(lock->orig_ref_name,"HEAD") !=0) {2519/*2520 * Special hack: If a branch is updated directly and HEAD2521 * points to it (may happen on the remote side of a push2522 * for example) then logically the HEAD reflog should be2523 * updated too.2524 * A generic solution implies reverse symref information,2525 * but finding all symrefs pointing to the given branch2526 * would be rather costly for this rare event (the direct2527 * update of a branch) to be worth it. So let's cheat and2528 * check with HEAD only which should cover 99% of all usage2529 * scenarios (even 100% of the default ones).2530 */2531unsigned char head_sha1[20];2532int head_flag;2533const char*head_ref;2534 head_ref =resolve_ref_unsafe("HEAD", head_sha1,1, &head_flag);2535if(head_ref && (head_flag & REF_ISSYMREF) &&2536!strcmp(head_ref, lock->ref_name))2537log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);2538}2539if(commit_ref(lock)) {2540error("Couldn't set%s", lock->ref_name);2541unlock_ref(lock);2542return-1;2543}2544unlock_ref(lock);2545return0;2546}25472548intcreate_symref(const char*ref_target,const char*refs_heads_master,2549const char*logmsg)2550{2551const char*lockpath;2552char ref[1000];2553int fd, len, written;2554char*git_HEAD =git_pathdup("%s", ref_target);2555unsigned char old_sha1[20], new_sha1[20];25562557if(logmsg &&read_ref(ref_target, old_sha1))2558hashclr(old_sha1);25592560if(safe_create_leading_directories(git_HEAD) <0)2561returnerror("unable to create directory for%s", git_HEAD);25622563#ifndef NO_SYMLINK_HEAD2564if(prefer_symlink_refs) {2565unlink(git_HEAD);2566if(!symlink(refs_heads_master, git_HEAD))2567goto done;2568fprintf(stderr,"no symlink - falling back to symbolic ref\n");2569}2570#endif25712572 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);2573if(sizeof(ref) <= len) {2574error("refname too long:%s", refs_heads_master);2575goto error_free_return;2576}2577 lockpath =mkpath("%s.lock", git_HEAD);2578 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);2579if(fd <0) {2580error("Unable to open%sfor writing", lockpath);2581goto error_free_return;2582}2583 written =write_in_full(fd, ref, len);2584if(close(fd) !=0|| written != len) {2585error("Unable to write to%s", lockpath);2586goto error_unlink_return;2587}2588if(rename(lockpath, git_HEAD) <0) {2589error("Unable to create%s", git_HEAD);2590goto error_unlink_return;2591}2592if(adjust_shared_perm(git_HEAD)) {2593error("Unable to fix permissions on%s", lockpath);2594 error_unlink_return:2595unlink_or_warn(lockpath);2596 error_free_return:2597free(git_HEAD);2598return-1;2599}26002601#ifndef NO_SYMLINK_HEAD2602 done:2603#endif2604if(logmsg && !read_ref(refs_heads_master, new_sha1))2605log_ref_write(ref_target, old_sha1, new_sha1, logmsg);26062607free(git_HEAD);2608return0;2609}26102611static char*ref_msg(const char*line,const char*endp)2612{2613const char*ep;2614 line +=82;2615 ep =memchr(line,'\n', endp - line);2616if(!ep)2617 ep = endp;2618returnxmemdupz(line, ep - line);2619}26202621intread_ref_at(const char*refname,unsigned long at_time,int cnt,2622unsigned char*sha1,char**msg,2623unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)2624{2625const char*logfile, *logdata, *logend, *rec, *lastgt, *lastrec;2626char*tz_c;2627int logfd, tz, reccnt =0;2628struct stat st;2629unsigned long date;2630unsigned char logged_sha1[20];2631void*log_mapped;2632size_t mapsz;26332634 logfile =git_path("logs/%s", refname);2635 logfd =open(logfile, O_RDONLY,0);2636if(logfd <0)2637die_errno("Unable to read log '%s'", logfile);2638fstat(logfd, &st);2639if(!st.st_size)2640die("Log%sis empty.", logfile);2641 mapsz =xsize_t(st.st_size);2642 log_mapped =xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd,0);2643 logdata = log_mapped;2644close(logfd);26452646 lastrec = NULL;2647 rec = logend = logdata + st.st_size;2648while(logdata < rec) {2649 reccnt++;2650if(logdata < rec && *(rec-1) =='\n')2651 rec--;2652 lastgt = NULL;2653while(logdata < rec && *(rec-1) !='\n') {2654 rec--;2655if(*rec =='>')2656 lastgt = rec;2657}2658if(!lastgt)2659die("Log%sis corrupt.", logfile);2660 date =strtoul(lastgt +1, &tz_c,10);2661if(date <= at_time || cnt ==0) {2662 tz =strtoul(tz_c, NULL,10);2663if(msg)2664*msg =ref_msg(rec, logend);2665if(cutoff_time)2666*cutoff_time = date;2667if(cutoff_tz)2668*cutoff_tz = tz;2669if(cutoff_cnt)2670*cutoff_cnt = reccnt -1;2671if(lastrec) {2672if(get_sha1_hex(lastrec, logged_sha1))2673die("Log%sis corrupt.", logfile);2674if(get_sha1_hex(rec +41, sha1))2675die("Log%sis corrupt.", logfile);2676if(hashcmp(logged_sha1, sha1)) {2677warning("Log%shas gap after%s.",2678 logfile,show_date(date, tz, DATE_RFC2822));2679}2680}2681else if(date == at_time) {2682if(get_sha1_hex(rec +41, sha1))2683die("Log%sis corrupt.", logfile);2684}2685else{2686if(get_sha1_hex(rec +41, logged_sha1))2687die("Log%sis corrupt.", logfile);2688if(hashcmp(logged_sha1, sha1)) {2689warning("Log%sunexpectedly ended on%s.",2690 logfile,show_date(date, tz, DATE_RFC2822));2691}2692}2693munmap(log_mapped, mapsz);2694return0;2695}2696 lastrec = rec;2697if(cnt >0)2698 cnt--;2699}27002701 rec = logdata;2702while(rec < logend && *rec !='>'&& *rec !='\n')2703 rec++;2704if(rec == logend || *rec =='\n')2705die("Log%sis corrupt.", logfile);2706 date =strtoul(rec +1, &tz_c,10);2707 tz =strtoul(tz_c, NULL,10);2708if(get_sha1_hex(logdata, sha1))2709die("Log%sis corrupt.", logfile);2710if(is_null_sha1(sha1)) {2711if(get_sha1_hex(logdata +41, sha1))2712die("Log%sis corrupt.", logfile);2713}2714if(msg)2715*msg =ref_msg(logdata, logend);2716munmap(log_mapped, mapsz);27172718if(cutoff_time)2719*cutoff_time = date;2720if(cutoff_tz)2721*cutoff_tz = tz;2722if(cutoff_cnt)2723*cutoff_cnt = reccnt;2724return1;2725}27262727intfor_each_recent_reflog_ent(const char*refname, each_reflog_ent_fn fn,long ofs,void*cb_data)2728{2729const char*logfile;2730FILE*logfp;2731struct strbuf sb = STRBUF_INIT;2732int ret =0;27332734 logfile =git_path("logs/%s", refname);2735 logfp =fopen(logfile,"r");2736if(!logfp)2737return-1;27382739if(ofs) {2740struct stat statbuf;2741if(fstat(fileno(logfp), &statbuf) ||2742 statbuf.st_size < ofs ||2743fseek(logfp, -ofs, SEEK_END) ||2744strbuf_getwholeline(&sb, logfp,'\n')) {2745fclose(logfp);2746strbuf_release(&sb);2747return-1;2748}2749}27502751while(!strbuf_getwholeline(&sb, logfp,'\n')) {2752unsigned char osha1[20], nsha1[20];2753char*email_end, *message;2754unsigned long timestamp;2755int tz;27562757/* old SP new SP name <email> SP time TAB msg LF */2758if(sb.len <83|| sb.buf[sb.len -1] !='\n'||2759get_sha1_hex(sb.buf, osha1) || sb.buf[40] !=' '||2760get_sha1_hex(sb.buf +41, nsha1) || sb.buf[81] !=' '||2761!(email_end =strchr(sb.buf +82,'>')) ||2762 email_end[1] !=' '||2763!(timestamp =strtoul(email_end +2, &message,10)) ||2764!message || message[0] !=' '||2765(message[1] !='+'&& message[1] !='-') ||2766!isdigit(message[2]) || !isdigit(message[3]) ||2767!isdigit(message[4]) || !isdigit(message[5]))2768continue;/* corrupt? */2769 email_end[1] ='\0';2770 tz =strtol(message +1, NULL,10);2771if(message[6] !='\t')2772 message +=6;2773else2774 message +=7;2775 ret =fn(osha1, nsha1, sb.buf +82, timestamp, tz, message,2776 cb_data);2777if(ret)2778break;2779}2780fclose(logfp);2781strbuf_release(&sb);2782return ret;2783}27842785intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)2786{2787returnfor_each_recent_reflog_ent(refname, fn,0, cb_data);2788}27892790/*2791 * Call fn for each reflog in the namespace indicated by name. name2792 * must be empty or end with '/'. Name will be used as a scratch2793 * space, but its contents will be restored before return.2794 */2795static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)2796{2797DIR*d =opendir(git_path("logs/%s", name->buf));2798int retval =0;2799struct dirent *de;2800int oldlen = name->len;28012802if(!d)2803return name->len ? errno :0;28042805while((de =readdir(d)) != NULL) {2806struct stat st;28072808if(de->d_name[0] =='.')2809continue;2810if(has_extension(de->d_name,".lock"))2811continue;2812strbuf_addstr(name, de->d_name);2813if(stat(git_path("logs/%s", name->buf), &st) <0) {2814;/* silently ignore */2815}else{2816if(S_ISDIR(st.st_mode)) {2817strbuf_addch(name,'/');2818 retval =do_for_each_reflog(name, fn, cb_data);2819}else{2820unsigned char sha1[20];2821if(read_ref_full(name->buf, sha1,0, NULL))2822 retval =error("bad ref for%s", name->buf);2823else2824 retval =fn(name->buf, sha1,0, cb_data);2825}2826if(retval)2827break;2828}2829strbuf_setlen(name, oldlen);2830}2831closedir(d);2832return retval;2833}28342835intfor_each_reflog(each_ref_fn fn,void*cb_data)2836{2837int retval;2838struct strbuf name;2839strbuf_init(&name, PATH_MAX);2840 retval =do_for_each_reflog(&name, fn, cb_data);2841strbuf_release(&name);2842return retval;2843}28442845intupdate_ref(const char*action,const char*refname,2846const unsigned char*sha1,const unsigned char*oldval,2847int flags,enum action_on_err onerr)2848{2849static struct ref_lock *lock;2850 lock =lock_any_ref_for_update(refname, oldval, flags);2851if(!lock) {2852const char*str ="Cannot lock the ref '%s'.";2853switch(onerr) {2854case MSG_ON_ERR:error(str, refname);break;2855case DIE_ON_ERR:die(str, refname);break;2856case QUIET_ON_ERR:break;2857}2858return1;2859}2860if(write_ref_sha1(lock, sha1, action) <0) {2861const char*str ="Cannot update the ref '%s'.";2862switch(onerr) {2863case MSG_ON_ERR:error(str, refname);break;2864case DIE_ON_ERR:die(str, refname);break;2865case QUIET_ON_ERR:break;2866}2867return1;2868}2869return0;2870}28712872struct ref *find_ref_by_name(const struct ref *list,const char*name)2873{2874for( ; list; list = list->next)2875if(!strcmp(list->name, name))2876return(struct ref *)list;2877return NULL;2878}28792880/*2881 * generate a format suitable for scanf from a ref_rev_parse_rules2882 * rule, that is replace the "%.*s" spec with a "%s" spec2883 */2884static voidgen_scanf_fmt(char*scanf_fmt,const char*rule)2885{2886char*spec;28872888 spec =strstr(rule,"%.*s");2889if(!spec ||strstr(spec +4,"%.*s"))2890die("invalid rule in ref_rev_parse_rules:%s", rule);28912892/* copy all until spec */2893strncpy(scanf_fmt, rule, spec - rule);2894 scanf_fmt[spec - rule] ='\0';2895/* copy new spec */2896strcat(scanf_fmt,"%s");2897/* copy remaining rule */2898strcat(scanf_fmt, spec +4);28992900return;2901}29022903char*shorten_unambiguous_ref(const char*refname,int strict)2904{2905int i;2906static char**scanf_fmts;2907static int nr_rules;2908char*short_name;29092910/* pre generate scanf formats from ref_rev_parse_rules[] */2911if(!nr_rules) {2912size_t total_len =0;29132914/* the rule list is NULL terminated, count them first */2915for(; ref_rev_parse_rules[nr_rules]; nr_rules++)2916/* no +1 because strlen("%s") < strlen("%.*s") */2917 total_len +=strlen(ref_rev_parse_rules[nr_rules]);29182919 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);29202921 total_len =0;2922for(i =0; i < nr_rules; i++) {2923 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules]2924+ total_len;2925gen_scanf_fmt(scanf_fmts[i], ref_rev_parse_rules[i]);2926 total_len +=strlen(ref_rev_parse_rules[i]);2927}2928}29292930/* bail out if there are no rules */2931if(!nr_rules)2932returnxstrdup(refname);29332934/* buffer for scanf result, at most refname must fit */2935 short_name =xstrdup(refname);29362937/* skip first rule, it will always match */2938for(i = nr_rules -1; i >0; --i) {2939int j;2940int rules_to_fail = i;2941int short_name_len;29422943if(1!=sscanf(refname, scanf_fmts[i], short_name))2944continue;29452946 short_name_len =strlen(short_name);29472948/*2949 * in strict mode, all (except the matched one) rules2950 * must fail to resolve to a valid non-ambiguous ref2951 */2952if(strict)2953 rules_to_fail = nr_rules;29542955/*2956 * check if the short name resolves to a valid ref,2957 * but use only rules prior to the matched one2958 */2959for(j =0; j < rules_to_fail; j++) {2960const char*rule = ref_rev_parse_rules[j];2961char refname[PATH_MAX];29622963/* skip matched rule */2964if(i == j)2965continue;29662967/*2968 * the short name is ambiguous, if it resolves2969 * (with this previous rule) to a valid ref2970 * read_ref() returns 0 on success2971 */2972mksnpath(refname,sizeof(refname),2973 rule, short_name_len, short_name);2974if(ref_exists(refname))2975break;2976}29772978/*2979 * short name is non-ambiguous if all previous rules2980 * haven't resolved to a valid ref2981 */2982if(j == rules_to_fail)2983return short_name;2984}29852986free(short_name);2987returnxstrdup(refname);2988}