1#include"cache.h" 2#include"refs.h" 3#include"object.h" 4#include"tag.h" 5#include"dir.h" 6#include"string-list.h" 7 8/* 9 * How to handle various characters in refnames: 10 * This table is used by both the SIMD and non-SIMD code. It has 11 * some cases that are only useful for the SIMD; these are handled 12 * equivalently to the listed disposition in the non-SIMD code. 13 * 0: An acceptable character for refs 14 * 1: @, look for a following { to reject @{ in refs (SIMD or = 0) 15 * 2: \0: End-of-component and string 16 * 3: /: End-of-component (SIMD or = 2) 17 * 4: ., look for a preceding . to reject .. in refs 18 * 5: {, look for a preceding @ to reject @{ in refs 19 * 6: *, usually a bad character except, once as a wildcard (SIMD or = 7) 20 * 7: A bad character except * (see check_refname_component below) 21 */ 22static unsigned char refname_disposition[256] = { 232,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 247,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, 257,0,0,0,0,0,0,0,0,0,6,0,0,0,4,3, 260,0,0,0,0,0,0,0,0,0,7,0,0,0,0,7, 271,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 280,0,0,0,0,0,0,0,0,0,0,7,7,0,7,0, 290,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 300,0,0,0,0,0,0,0,0,0,0,5,0,0,7,7 31}; 32 33/* 34 * Try to read one refname component from the front of refname. 35 * Return the length of the component found, or -1 if the component is 36 * not legal. It is legal if it is something reasonable to have under 37 * ".git/refs/"; We do not like it if: 38 * 39 * - any path component of it begins with ".", or 40 * - it has double dots "..", or 41 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 42 * - it has pattern-matching notation "*", "?", "[", anywhere, or 43 * - it ends with a "/", or 44 * - it ends with ".lock", or 45 * - it contains a "\" (backslash) 46 */ 47static intcheck_refname_component(const char*refname,int flags) 48{ 49const char*cp; 50char last ='\0'; 51 52for(cp = refname; ; cp++) { 53int ch = *cp &255; 54unsigned char disp = refname_disposition[ch]; 55switch(disp) { 56case2:/* fall-through */ 57case3: 58goto out; 59case4: 60if(last =='.') 61return-1;/* Refname contains "..". */ 62break; 63case5: 64if(last =='@') 65return-1;/* Refname contains "@{". */ 66break; 67case6:/* fall-through */ 68case7: 69return-1; 70} 71 last = ch; 72} 73out: 74if(cp == refname) 75return0;/* Component has zero length. */ 76if(refname[0] =='.') { 77if(!(flags & REFNAME_DOT_COMPONENT)) 78return-1;/* Component starts with '.'. */ 79/* 80 * Even if leading dots are allowed, don't allow "." 81 * as a component (".." is prevented by a rule above). 82 */ 83if(refname[1] =='\0') 84return-1;/* Component equals ".". */ 85} 86if(cp - refname >=5&& !memcmp(cp -5,".lock",5)) 87return-1;/* Refname ends with ".lock". */ 88return cp - refname; 89} 90 91static intcheck_refname_format_bytewise(const char*refname,int flags) 92{ 93int component_len, component_count =0; 94 95if(!strcmp(refname,"@")) 96/* Refname is a single character '@'. */ 97return-1; 98 99while(1) { 100/* We are at the start of a path component. */ 101 component_len =check_refname_component(refname, flags); 102if(component_len <=0) { 103if((flags & REFNAME_REFSPEC_PATTERN) && 104 refname[0] =='*'&& 105(refname[1] =='\0'|| refname[1] =='/')) { 106/* Accept one wildcard as a full refname component. */ 107 flags &= ~REFNAME_REFSPEC_PATTERN; 108 component_len =1; 109}else{ 110return-1; 111} 112} 113 component_count++; 114if(refname[component_len] =='\0') 115break; 116/* Skip to next component. */ 117 refname += component_len +1; 118} 119 120if(refname[component_len -1] =='.') 121return-1;/* Refname ends with '.'. */ 122if(!(flags & REFNAME_ALLOW_ONELEVEL) && component_count <2) 123return-1;/* Refname has only one component. */ 124return0; 125} 126 127#if defined(__GNUC__) && defined(__x86_64__) 128#define SSE_VECTOR_BYTES 16 129 130/* Vectorized version of check_refname_format. */ 131intcheck_refname_format(const char*refname,int flags) 132{ 133const char*cp = refname; 134 135const __m128i dot =_mm_set1_epi8('.'); 136const __m128i at =_mm_set1_epi8('@'); 137const __m128i curly =_mm_set1_epi8('{'); 138const __m128i slash =_mm_set1_epi8('/'); 139const __m128i zero =_mm_set1_epi8('\000'); 140const __m128i el =_mm_set1_epi8('l'); 141 142/* below '*', all characters are forbidden or rare */ 143const __m128i star_ub =_mm_set1_epi8('*'+1); 144 145const __m128i colon =_mm_set1_epi8(':'); 146const __m128i question =_mm_set1_epi8('?'); 147 148/* '['..'^' contains 4 characters: 3 forbidden and 1 rare */ 149const __m128i bracket_lb =_mm_set1_epi8('['-1); 150const __m128i caret_ub =_mm_set1_epi8('^'+1); 151 152/* '~' and above are forbidden */ 153const __m128i tilde_lb =_mm_set1_epi8('~'-1); 154 155int component_count =0; 156int orig_flags = flags; 157 158if(refname[0] ==0|| refname[0] =='/') { 159/* entirely empty ref or initial ref component */ 160return-1; 161} 162 163/* 164 * Initial ref component of '.'; below we look for /. so we'll 165 * miss this. 166 */ 167if(refname[0] =='.') { 168if(refname[1] =='/'|| refname[1] =='\0') 169return-1; 170if(!(flags & REFNAME_DOT_COMPONENT)) 171return-1; 172} 173while(1) { 174 __m128i tmp, tmp1, result; 175uint64_t mask; 176 177if((uintptr_t) cp % PAGE_SIZE > PAGE_SIZE - SSE_VECTOR_BYTES -1) 178/* 179 * End-of-page; fall back to slow method for 180 * this entire ref. 181 */ 182returncheck_refname_format_bytewise(refname, orig_flags); 183 184 tmp =_mm_loadu_si128((__m128i *)cp); 185 tmp1 =_mm_loadu_si128((__m128i *)(cp +1)); 186 187/* 188 * This range (note the lt) contains some 189 * permissible-but-rare characters (including all 190 * characters >= 128), which we handle later. It also 191 * includes \000. 192 */ 193 result =_mm_cmplt_epi8(tmp, star_ub); 194 195 result =_mm_or_si128(result,_mm_cmpeq_epi8(tmp, question)); 196 result =_mm_or_si128(result,_mm_cmpeq_epi8(tmp, colon)); 197 198/* This range contains the permissible ] as bycatch */ 199 result =_mm_or_si128(result,_mm_and_si128( 200_mm_cmpgt_epi8(tmp, bracket_lb), 201_mm_cmplt_epi8(tmp, caret_ub))); 202 203 result =_mm_or_si128(result,_mm_cmpgt_epi8(tmp, tilde_lb)); 204 205/* .. */ 206 result =_mm_or_si128(result,_mm_and_si128( 207_mm_cmpeq_epi8(tmp, dot), 208_mm_cmpeq_epi8(tmp1, dot))); 209/* @{ */ 210 result =_mm_or_si128(result,_mm_and_si128( 211_mm_cmpeq_epi8(tmp, at), 212_mm_cmpeq_epi8(tmp1, curly))); 213/* // */ 214 result =_mm_or_si128(result,_mm_and_si128( 215_mm_cmpeq_epi8(tmp, slash), 216_mm_cmpeq_epi8(tmp1, slash))); 217/* trailing / */ 218 result =_mm_or_si128(result,_mm_and_si128( 219_mm_cmpeq_epi8(tmp, slash), 220_mm_cmpeq_epi8(tmp1, zero))); 221/* .l, beginning of .lock */ 222 result =_mm_or_si128(result,_mm_and_si128( 223_mm_cmpeq_epi8(tmp, dot), 224_mm_cmpeq_epi8(tmp1, el))); 225/* 226 * Even though /. is not necessarily an error, we flag 227 * it anyway. If we find it, we'll check if it's valid 228 * and if so we'll advance just past it. 229 */ 230 result =_mm_or_si128(result,_mm_and_si128( 231_mm_cmpeq_epi8(tmp, slash), 232_mm_cmpeq_epi8(tmp1, dot))); 233 234 mask =_mm_movemask_epi8(result); 235if(mask) { 236/* 237 * We've found either end-of-string, or some 238 * probably-bad character or substring. 239 */ 240int i =__builtin_ctz(mask); 241switch(refname_disposition[cp[i] &255]) { 242case0:/* fall-through */ 243case5: 244/* 245 * bycatch: a good character that's in 246 * one of the ranges of mostly-forbidden 247 * characters 248 */ 249 cp += i +1; 250break; 251case1: 252if(cp[i +1] =='{') 253return-1; 254 cp += i +1; 255break; 256case2: 257if(!(flags & REFNAME_ALLOW_ONELEVEL) 258&& !component_count && !strchr(refname,'/')) 259/* Refname has only one component. */ 260return-1; 261return0; 262case3: 263 component_count ++; 264/* 265 * Even if leading dots are allowed, don't 266 * allow "." as a component (".." is 267 * prevented by case 4 below). 268 */ 269if(cp[i +1] =='.') { 270if(cp[i +2] =='\0') 271return-1; 272if(flags & REFNAME_DOT_COMPONENT) { 273/* skip to just after the /. */ 274 cp += i +2; 275break; 276} 277return-1; 278}else if(cp[i +1] =='/'|| cp[i +1] =='\0') 279return-1; 280break; 281case4: 282if(cp[i +1] =='.'|| cp[i +1] =='\0') 283return-1; 284/* .lock as end-of-component or end-of-string */ 285if((!strncmp(cp + i,".lock",5)) 286&& (cp[i +5] =='/'|| cp[i +5] ==0)) 287return-1; 288 cp +=1; 289break; 290case6: 291if(((cp == refname + i) || cp[i -1] =='/') 292&& (cp[i +1] =='/'|| cp[i +1] ==0)) 293if(flags & REFNAME_REFSPEC_PATTERN) { 294 flags &= ~REFNAME_REFSPEC_PATTERN; 295/* restart after the * */ 296 cp += i +1; 297continue; 298} 299/* fall-through */ 300case7: 301return-1; 302} 303}else 304 cp += SSE_VECTOR_BYTES; 305} 306} 307 308#else 309 310intcheck_refname_format(const char*refname,int flags) 311{ 312returncheck_refname_format_bytewise(refname, flags); 313} 314 315#endif 316 317struct ref_entry; 318 319/* 320 * Information used (along with the information in ref_entry) to 321 * describe a single cached reference. This data structure only 322 * occurs embedded in a union in struct ref_entry, and only when 323 * (ref_entry->flag & REF_DIR) is zero. 324 */ 325struct ref_value { 326/* 327 * The name of the object to which this reference resolves 328 * (which may be a tag object). If REF_ISBROKEN, this is 329 * null. If REF_ISSYMREF, then this is the name of the object 330 * referred to by the last reference in the symlink chain. 331 */ 332unsigned char sha1[20]; 333 334/* 335 * If REF_KNOWS_PEELED, then this field holds the peeled value 336 * of this reference, or null if the reference is known not to 337 * be peelable. See the documentation for peel_ref() for an 338 * exact definition of "peelable". 339 */ 340unsigned char peeled[20]; 341}; 342 343struct ref_cache; 344 345/* 346 * Information used (along with the information in ref_entry) to 347 * describe a level in the hierarchy of references. This data 348 * structure only occurs embedded in a union in struct ref_entry, and 349 * only when (ref_entry.flag & REF_DIR) is set. In that case, 350 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 351 * in the directory have already been read: 352 * 353 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 354 * or packed references, already read. 355 * 356 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 357 * references that hasn't been read yet (nor has any of its 358 * subdirectories). 359 * 360 * Entries within a directory are stored within a growable array of 361 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 362 * sorted are sorted by their component name in strcmp() order and the 363 * remaining entries are unsorted. 364 * 365 * Loose references are read lazily, one directory at a time. When a 366 * directory of loose references is read, then all of the references 367 * in that directory are stored, and REF_INCOMPLETE stubs are created 368 * for any subdirectories, but the subdirectories themselves are not 369 * read. The reading is triggered by get_ref_dir(). 370 */ 371struct ref_dir { 372int nr, alloc; 373 374/* 375 * Entries with index 0 <= i < sorted are sorted by name. New 376 * entries are appended to the list unsorted, and are sorted 377 * only when required; thus we avoid the need to sort the list 378 * after the addition of every reference. 379 */ 380int sorted; 381 382/* A pointer to the ref_cache that contains this ref_dir. */ 383struct ref_cache *ref_cache; 384 385struct ref_entry **entries; 386}; 387 388/* 389 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 390 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see 391 * refs.h. 392 */ 393 394/* 395 * The field ref_entry->u.value.peeled of this value entry contains 396 * the correct peeled value for the reference, which might be 397 * null_sha1 if the reference is not a tag or if it is broken. 398 */ 399#define REF_KNOWS_PEELED 0x08 400 401/* ref_entry represents a directory of references */ 402#define REF_DIR 0x10 403 404/* 405 * Entry has not yet been read from disk (used only for REF_DIR 406 * entries representing loose references) 407 */ 408#define REF_INCOMPLETE 0x20 409 410/* 411 * A ref_entry represents either a reference or a "subdirectory" of 412 * references. 413 * 414 * Each directory in the reference namespace is represented by a 415 * ref_entry with (flags & REF_DIR) set and containing a subdir member 416 * that holds the entries in that directory that have been read so 417 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 418 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 419 * used for loose reference directories. 420 * 421 * References are represented by a ref_entry with (flags & REF_DIR) 422 * unset and a value member that describes the reference's value. The 423 * flag member is at the ref_entry level, but it is also needed to 424 * interpret the contents of the value field (in other words, a 425 * ref_value object is not very much use without the enclosing 426 * ref_entry). 427 * 428 * Reference names cannot end with slash and directories' names are 429 * always stored with a trailing slash (except for the top-level 430 * directory, which is always denoted by ""). This has two nice 431 * consequences: (1) when the entries in each subdir are sorted 432 * lexicographically by name (as they usually are), the references in 433 * a whole tree can be generated in lexicographic order by traversing 434 * the tree in left-to-right, depth-first order; (2) the names of 435 * references and subdirectories cannot conflict, and therefore the 436 * presence of an empty subdirectory does not block the creation of a 437 * similarly-named reference. (The fact that reference names with the 438 * same leading components can conflict *with each other* is a 439 * separate issue that is regulated by is_refname_available().) 440 * 441 * Please note that the name field contains the fully-qualified 442 * reference (or subdirectory) name. Space could be saved by only 443 * storing the relative names. But that would require the full names 444 * to be generated on the fly when iterating in do_for_each_ref(), and 445 * would break callback functions, who have always been able to assume 446 * that the name strings that they are passed will not be freed during 447 * the iteration. 448 */ 449struct ref_entry { 450unsigned char flag;/* ISSYMREF? ISPACKED? */ 451union{ 452struct ref_value value;/* if not (flags&REF_DIR) */ 453struct ref_dir subdir;/* if (flags&REF_DIR) */ 454} u; 455/* 456 * The full name of the reference (e.g., "refs/heads/master") 457 * or the full name of the directory with a trailing slash 458 * (e.g., "refs/heads/"): 459 */ 460char name[FLEX_ARRAY]; 461}; 462 463static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 464 465static struct ref_dir *get_ref_dir(struct ref_entry *entry) 466{ 467struct ref_dir *dir; 468assert(entry->flag & REF_DIR); 469 dir = &entry->u.subdir; 470if(entry->flag & REF_INCOMPLETE) { 471read_loose_refs(entry->name, dir); 472 entry->flag &= ~REF_INCOMPLETE; 473} 474return dir; 475} 476 477static struct ref_entry *create_ref_entry(const char*refname, 478const unsigned char*sha1,int flag, 479int check_name) 480{ 481int len; 482struct ref_entry *ref; 483 484if(check_name && 485check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) 486die("Reference has invalid format: '%s'", refname); 487 len =strlen(refname) +1; 488 ref =xmalloc(sizeof(struct ref_entry) + len); 489hashcpy(ref->u.value.sha1, sha1); 490hashclr(ref->u.value.peeled); 491memcpy(ref->name, refname, len); 492 ref->flag = flag; 493return ref; 494} 495 496static voidclear_ref_dir(struct ref_dir *dir); 497 498static voidfree_ref_entry(struct ref_entry *entry) 499{ 500if(entry->flag & REF_DIR) { 501/* 502 * Do not use get_ref_dir() here, as that might 503 * trigger the reading of loose refs. 504 */ 505clear_ref_dir(&entry->u.subdir); 506} 507free(entry); 508} 509 510/* 511 * Add a ref_entry to the end of dir (unsorted). Entry is always 512 * stored directly in dir; no recursion into subdirectories is 513 * done. 514 */ 515static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 516{ 517ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 518 dir->entries[dir->nr++] = entry; 519/* optimize for the case that entries are added in order */ 520if(dir->nr ==1|| 521(dir->nr == dir->sorted +1&& 522strcmp(dir->entries[dir->nr -2]->name, 523 dir->entries[dir->nr -1]->name) <0)) 524 dir->sorted = dir->nr; 525} 526 527/* 528 * Clear and free all entries in dir, recursively. 529 */ 530static voidclear_ref_dir(struct ref_dir *dir) 531{ 532int i; 533for(i =0; i < dir->nr; i++) 534free_ref_entry(dir->entries[i]); 535free(dir->entries); 536 dir->sorted = dir->nr = dir->alloc =0; 537 dir->entries = NULL; 538} 539 540/* 541 * Create a struct ref_entry object for the specified dirname. 542 * dirname is the name of the directory with a trailing slash (e.g., 543 * "refs/heads/") or "" for the top-level directory. 544 */ 545static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 546const char*dirname,size_t len, 547int incomplete) 548{ 549struct ref_entry *direntry; 550 direntry =xcalloc(1,sizeof(struct ref_entry) + len +1); 551memcpy(direntry->name, dirname, len); 552 direntry->name[len] ='\0'; 553 direntry->u.subdir.ref_cache = ref_cache; 554 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 555return direntry; 556} 557 558static intref_entry_cmp(const void*a,const void*b) 559{ 560struct ref_entry *one = *(struct ref_entry **)a; 561struct ref_entry *two = *(struct ref_entry **)b; 562returnstrcmp(one->name, two->name); 563} 564 565static voidsort_ref_dir(struct ref_dir *dir); 566 567struct string_slice { 568size_t len; 569const char*str; 570}; 571 572static intref_entry_cmp_sslice(const void*key_,const void*ent_) 573{ 574const struct string_slice *key = key_; 575const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 576int cmp =strncmp(key->str, ent->name, key->len); 577if(cmp) 578return cmp; 579return'\0'- (unsigned char)ent->name[key->len]; 580} 581 582/* 583 * Return the index of the entry with the given refname from the 584 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 585 * no such entry is found. dir must already be complete. 586 */ 587static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 588{ 589struct ref_entry **r; 590struct string_slice key; 591 592if(refname == NULL || !dir->nr) 593return-1; 594 595sort_ref_dir(dir); 596 key.len = len; 597 key.str = refname; 598 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 599 ref_entry_cmp_sslice); 600 601if(r == NULL) 602return-1; 603 604return r - dir->entries; 605} 606 607/* 608 * Search for a directory entry directly within dir (without 609 * recursing). Sort dir if necessary. subdirname must be a directory 610 * name (i.e., end in '/'). If mkdir is set, then create the 611 * directory if it is missing; otherwise, return NULL if the desired 612 * directory cannot be found. dir must already be complete. 613 */ 614static struct ref_dir *search_for_subdir(struct ref_dir *dir, 615const char*subdirname,size_t len, 616int mkdir) 617{ 618int entry_index =search_ref_dir(dir, subdirname, len); 619struct ref_entry *entry; 620if(entry_index == -1) { 621if(!mkdir) 622return NULL; 623/* 624 * Since dir is complete, the absence of a subdir 625 * means that the subdir really doesn't exist; 626 * therefore, create an empty record for it but mark 627 * the record complete. 628 */ 629 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 630add_entry_to_dir(dir, entry); 631}else{ 632 entry = dir->entries[entry_index]; 633} 634returnget_ref_dir(entry); 635} 636 637/* 638 * If refname is a reference name, find the ref_dir within the dir 639 * tree that should hold refname. If refname is a directory name 640 * (i.e., ends in '/'), then return that ref_dir itself. dir must 641 * represent the top-level directory and must already be complete. 642 * Sort ref_dirs and recurse into subdirectories as necessary. If 643 * mkdir is set, then create any missing directories; otherwise, 644 * return NULL if the desired directory cannot be found. 645 */ 646static struct ref_dir *find_containing_dir(struct ref_dir *dir, 647const char*refname,int mkdir) 648{ 649const char*slash; 650for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 651size_t dirnamelen = slash - refname +1; 652struct ref_dir *subdir; 653 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 654if(!subdir) { 655 dir = NULL; 656break; 657} 658 dir = subdir; 659} 660 661return dir; 662} 663 664/* 665 * Find the value entry with the given name in dir, sorting ref_dirs 666 * and recursing into subdirectories as necessary. If the name is not 667 * found or it corresponds to a directory entry, return NULL. 668 */ 669static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 670{ 671int entry_index; 672struct ref_entry *entry; 673 dir =find_containing_dir(dir, refname,0); 674if(!dir) 675return NULL; 676 entry_index =search_ref_dir(dir, refname,strlen(refname)); 677if(entry_index == -1) 678return NULL; 679 entry = dir->entries[entry_index]; 680return(entry->flag & REF_DIR) ? NULL : entry; 681} 682 683/* 684 * Remove the entry with the given name from dir, recursing into 685 * subdirectories as necessary. If refname is the name of a directory 686 * (i.e., ends with '/'), then remove the directory and its contents. 687 * If the removal was successful, return the number of entries 688 * remaining in the directory entry that contained the deleted entry. 689 * If the name was not found, return -1. Please note that this 690 * function only deletes the entry from the cache; it does not delete 691 * it from the filesystem or ensure that other cache entries (which 692 * might be symbolic references to the removed entry) are updated. 693 * Nor does it remove any containing dir entries that might be made 694 * empty by the removal. dir must represent the top-level directory 695 * and must already be complete. 696 */ 697static intremove_entry(struct ref_dir *dir,const char*refname) 698{ 699int refname_len =strlen(refname); 700int entry_index; 701struct ref_entry *entry; 702int is_dir = refname[refname_len -1] =='/'; 703if(is_dir) { 704/* 705 * refname represents a reference directory. Remove 706 * the trailing slash; otherwise we will get the 707 * directory *representing* refname rather than the 708 * one *containing* it. 709 */ 710char*dirname =xmemdupz(refname, refname_len -1); 711 dir =find_containing_dir(dir, dirname,0); 712free(dirname); 713}else{ 714 dir =find_containing_dir(dir, refname,0); 715} 716if(!dir) 717return-1; 718 entry_index =search_ref_dir(dir, refname, refname_len); 719if(entry_index == -1) 720return-1; 721 entry = dir->entries[entry_index]; 722 723memmove(&dir->entries[entry_index], 724&dir->entries[entry_index +1], 725(dir->nr - entry_index -1) *sizeof(*dir->entries) 726); 727 dir->nr--; 728if(dir->sorted > entry_index) 729 dir->sorted--; 730free_ref_entry(entry); 731return dir->nr; 732} 733 734/* 735 * Add a ref_entry to the ref_dir (unsorted), recursing into 736 * subdirectories as necessary. dir must represent the top-level 737 * directory. Return 0 on success. 738 */ 739static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 740{ 741 dir =find_containing_dir(dir, ref->name,1); 742if(!dir) 743return-1; 744add_entry_to_dir(dir, ref); 745return0; 746} 747 748/* 749 * Emit a warning and return true iff ref1 and ref2 have the same name 750 * and the same sha1. Die if they have the same name but different 751 * sha1s. 752 */ 753static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 754{ 755if(strcmp(ref1->name, ref2->name)) 756return0; 757 758/* Duplicate name; make sure that they don't conflict: */ 759 760if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 761/* This is impossible by construction */ 762die("Reference directory conflict:%s", ref1->name); 763 764if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 765die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 766 767warning("Duplicated ref:%s", ref1->name); 768return1; 769} 770 771/* 772 * Sort the entries in dir non-recursively (if they are not already 773 * sorted) and remove any duplicate entries. 774 */ 775static voidsort_ref_dir(struct ref_dir *dir) 776{ 777int i, j; 778struct ref_entry *last = NULL; 779 780/* 781 * This check also prevents passing a zero-length array to qsort(), 782 * which is a problem on some platforms. 783 */ 784if(dir->sorted == dir->nr) 785return; 786 787qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 788 789/* Remove any duplicates: */ 790for(i =0, j =0; j < dir->nr; j++) { 791struct ref_entry *entry = dir->entries[j]; 792if(last &&is_dup_ref(last, entry)) 793free_ref_entry(entry); 794else 795 last = dir->entries[i++] = entry; 796} 797 dir->sorted = dir->nr = i; 798} 799 800/* Include broken references in a do_for_each_ref*() iteration: */ 801#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 802 803/* 804 * Return true iff the reference described by entry can be resolved to 805 * an object in the database. Emit a warning if the referred-to 806 * object does not exist. 807 */ 808static intref_resolves_to_object(struct ref_entry *entry) 809{ 810if(entry->flag & REF_ISBROKEN) 811return0; 812if(!has_sha1_file(entry->u.value.sha1)) { 813error("%sdoes not point to a valid object!", entry->name); 814return0; 815} 816return1; 817} 818 819/* 820 * current_ref is a performance hack: when iterating over references 821 * using the for_each_ref*() functions, current_ref is set to the 822 * current reference's entry before calling the callback function. If 823 * the callback function calls peel_ref(), then peel_ref() first 824 * checks whether the reference to be peeled is the current reference 825 * (it usually is) and if so, returns that reference's peeled version 826 * if it is available. This avoids a refname lookup in a common case. 827 */ 828static struct ref_entry *current_ref; 829 830typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 831 832struct ref_entry_cb { 833const char*base; 834int trim; 835int flags; 836 each_ref_fn *fn; 837void*cb_data; 838}; 839 840/* 841 * Handle one reference in a do_for_each_ref*()-style iteration, 842 * calling an each_ref_fn for each entry. 843 */ 844static intdo_one_ref(struct ref_entry *entry,void*cb_data) 845{ 846struct ref_entry_cb *data = cb_data; 847struct ref_entry *old_current_ref; 848int retval; 849 850if(!starts_with(entry->name, data->base)) 851return0; 852 853if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 854!ref_resolves_to_object(entry)) 855return0; 856 857/* Store the old value, in case this is a recursive call: */ 858 old_current_ref = current_ref; 859 current_ref = entry; 860 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 861 entry->flag, data->cb_data); 862 current_ref = old_current_ref; 863return retval; 864} 865 866/* 867 * Call fn for each reference in dir that has index in the range 868 * offset <= index < dir->nr. Recurse into subdirectories that are in 869 * that index range, sorting them before iterating. This function 870 * does not sort dir itself; it should be sorted beforehand. fn is 871 * called for all references, including broken ones. 872 */ 873static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 874 each_ref_entry_fn fn,void*cb_data) 875{ 876int i; 877assert(dir->sorted == dir->nr); 878for(i = offset; i < dir->nr; i++) { 879struct ref_entry *entry = dir->entries[i]; 880int retval; 881if(entry->flag & REF_DIR) { 882struct ref_dir *subdir =get_ref_dir(entry); 883sort_ref_dir(subdir); 884 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 885}else{ 886 retval =fn(entry, cb_data); 887} 888if(retval) 889return retval; 890} 891return0; 892} 893 894/* 895 * Call fn for each reference in the union of dir1 and dir2, in order 896 * by refname. Recurse into subdirectories. If a value entry appears 897 * in both dir1 and dir2, then only process the version that is in 898 * dir2. The input dirs must already be sorted, but subdirs will be 899 * sorted as needed. fn is called for all references, including 900 * broken ones. 901 */ 902static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 903struct ref_dir *dir2, 904 each_ref_entry_fn fn,void*cb_data) 905{ 906int retval; 907int i1 =0, i2 =0; 908 909assert(dir1->sorted == dir1->nr); 910assert(dir2->sorted == dir2->nr); 911while(1) { 912struct ref_entry *e1, *e2; 913int cmp; 914if(i1 == dir1->nr) { 915returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 916} 917if(i2 == dir2->nr) { 918returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 919} 920 e1 = dir1->entries[i1]; 921 e2 = dir2->entries[i2]; 922 cmp =strcmp(e1->name, e2->name); 923if(cmp ==0) { 924if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 925/* Both are directories; descend them in parallel. */ 926struct ref_dir *subdir1 =get_ref_dir(e1); 927struct ref_dir *subdir2 =get_ref_dir(e2); 928sort_ref_dir(subdir1); 929sort_ref_dir(subdir2); 930 retval =do_for_each_entry_in_dirs( 931 subdir1, subdir2, fn, cb_data); 932 i1++; 933 i2++; 934}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 935/* Both are references; ignore the one from dir1. */ 936 retval =fn(e2, cb_data); 937 i1++; 938 i2++; 939}else{ 940die("conflict between reference and directory:%s", 941 e1->name); 942} 943}else{ 944struct ref_entry *e; 945if(cmp <0) { 946 e = e1; 947 i1++; 948}else{ 949 e = e2; 950 i2++; 951} 952if(e->flag & REF_DIR) { 953struct ref_dir *subdir =get_ref_dir(e); 954sort_ref_dir(subdir); 955 retval =do_for_each_entry_in_dir( 956 subdir,0, fn, cb_data); 957}else{ 958 retval =fn(e, cb_data); 959} 960} 961if(retval) 962return retval; 963} 964} 965 966/* 967 * Load all of the refs from the dir into our in-memory cache. The hard work 968 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 969 * through all of the sub-directories. We do not even need to care about 970 * sorting, as traversal order does not matter to us. 971 */ 972static voidprime_ref_dir(struct ref_dir *dir) 973{ 974int i; 975for(i =0; i < dir->nr; i++) { 976struct ref_entry *entry = dir->entries[i]; 977if(entry->flag & REF_DIR) 978prime_ref_dir(get_ref_dir(entry)); 979} 980} 981/* 982 * Return true iff refname1 and refname2 conflict with each other. 983 * Two reference names conflict if one of them exactly matches the 984 * leading components of the other; e.g., "foo/bar" conflicts with 985 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 986 * "foo/barbados". 987 */ 988static intnames_conflict(const char*refname1,const char*refname2) 989{ 990for(; *refname1 && *refname1 == *refname2; refname1++, refname2++) 991; 992return(*refname1 =='\0'&& *refname2 =='/') 993|| (*refname1 =='/'&& *refname2 =='\0'); 994} 995 996struct name_conflict_cb { 997const char*refname; 998const char*oldrefname; 999const char*conflicting_refname;1000};10011002static intname_conflict_fn(struct ref_entry *entry,void*cb_data)1003{1004struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;1005if(data->oldrefname && !strcmp(data->oldrefname, entry->name))1006return0;1007if(names_conflict(data->refname, entry->name)) {1008 data->conflicting_refname = entry->name;1009return1;1010}1011return0;1012}10131014/*1015 * Return true iff a reference named refname could be created without1016 * conflicting with the name of an existing reference in dir. If1017 * oldrefname is non-NULL, ignore potential conflicts with oldrefname1018 * (e.g., because oldrefname is scheduled for deletion in the same1019 * operation).1020 */1021static intis_refname_available(const char*refname,const char*oldrefname,1022struct ref_dir *dir)1023{1024struct name_conflict_cb data;1025 data.refname = refname;1026 data.oldrefname = oldrefname;1027 data.conflicting_refname = NULL;10281029sort_ref_dir(dir);1030if(do_for_each_entry_in_dir(dir,0, name_conflict_fn, &data)) {1031error("'%s' exists; cannot create '%s'",1032 data.conflicting_refname, refname);1033return0;1034}1035return1;1036}10371038struct packed_ref_cache {1039struct ref_entry *root;10401041/*1042 * Count of references to the data structure in this instance,1043 * including the pointer from ref_cache::packed if any. The1044 * data will not be freed as long as the reference count is1045 * nonzero.1046 */1047unsigned int referrers;10481049/*1050 * Iff the packed-refs file associated with this instance is1051 * currently locked for writing, this points at the associated1052 * lock (which is owned by somebody else). The referrer count1053 * is also incremented when the file is locked and decremented1054 * when it is unlocked.1055 */1056struct lock_file *lock;10571058/* The metadata from when this packed-refs cache was read */1059struct stat_validity validity;1060};10611062/*1063 * Future: need to be in "struct repository"1064 * when doing a full libification.1065 */1066static struct ref_cache {1067struct ref_cache *next;1068struct ref_entry *loose;1069struct packed_ref_cache *packed;1070/*1071 * The submodule name, or "" for the main repo. We allocate1072 * length 1 rather than FLEX_ARRAY so that the main ref_cache1073 * is initialized correctly.1074 */1075char name[1];1076} ref_cache, *submodule_ref_caches;10771078/* Lock used for the main packed-refs file: */1079static struct lock_file packlock;10801081/*1082 * Increment the reference count of *packed_refs.1083 */1084static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs)1085{1086 packed_refs->referrers++;1087}10881089/*1090 * Decrease the reference count of *packed_refs. If it goes to zero,1091 * free *packed_refs and return true; otherwise return false.1092 */1093static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs)1094{1095if(!--packed_refs->referrers) {1096free_ref_entry(packed_refs->root);1097stat_validity_clear(&packed_refs->validity);1098free(packed_refs);1099return1;1100}else{1101return0;1102}1103}11041105static voidclear_packed_ref_cache(struct ref_cache *refs)1106{1107if(refs->packed) {1108struct packed_ref_cache *packed_refs = refs->packed;11091110if(packed_refs->lock)1111die("internal error: packed-ref cache cleared while locked");1112 refs->packed = NULL;1113release_packed_ref_cache(packed_refs);1114}1115}11161117static voidclear_loose_ref_cache(struct ref_cache *refs)1118{1119if(refs->loose) {1120free_ref_entry(refs->loose);1121 refs->loose = NULL;1122}1123}11241125static struct ref_cache *create_ref_cache(const char*submodule)1126{1127int len;1128struct ref_cache *refs;1129if(!submodule)1130 submodule ="";1131 len =strlen(submodule) +1;1132 refs =xcalloc(1,sizeof(struct ref_cache) + len);1133memcpy(refs->name, submodule, len);1134return refs;1135}11361137/*1138 * Return a pointer to a ref_cache for the specified submodule. For1139 * the main repository, use submodule==NULL. The returned structure1140 * will be allocated and initialized but not necessarily populated; it1141 * should not be freed.1142 */1143static struct ref_cache *get_ref_cache(const char*submodule)1144{1145struct ref_cache *refs;11461147if(!submodule || !*submodule)1148return&ref_cache;11491150for(refs = submodule_ref_caches; refs; refs = refs->next)1151if(!strcmp(submodule, refs->name))1152return refs;11531154 refs =create_ref_cache(submodule);1155 refs->next = submodule_ref_caches;1156 submodule_ref_caches = refs;1157return refs;1158}11591160/* The length of a peeled reference line in packed-refs, including EOL: */1161#define PEELED_LINE_LENGTH 4211621163/*1164 * The packed-refs header line that we write out. Perhaps other1165 * traits will be added later. The trailing space is required.1166 */1167static const char PACKED_REFS_HEADER[] =1168"# pack-refs with: peeled fully-peeled\n";11691170/*1171 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1172 * Return a pointer to the refname within the line (null-terminated),1173 * or NULL if there was a problem.1174 */1175static const char*parse_ref_line(char*line,unsigned char*sha1)1176{1177/*1178 * 42: the answer to everything.1179 *1180 * In this case, it happens to be the answer to1181 * 40 (length of sha1 hex representation)1182 * +1 (space in between hex and name)1183 * +1 (newline at the end of the line)1184 */1185int len =strlen(line) -42;11861187if(len <=0)1188return NULL;1189if(get_sha1_hex(line, sha1) <0)1190return NULL;1191if(!isspace(line[40]))1192return NULL;1193 line +=41;1194if(isspace(*line))1195return NULL;1196if(line[len] !='\n')1197return NULL;1198 line[len] =0;11991200return line;1201}12021203/*1204 * Read f, which is a packed-refs file, into dir.1205 *1206 * A comment line of the form "# pack-refs with: " may contain zero or1207 * more traits. We interpret the traits as follows:1208 *1209 * No traits:1210 *1211 * Probably no references are peeled. But if the file contains a1212 * peeled value for a reference, we will use it.1213 *1214 * peeled:1215 *1216 * References under "refs/tags/", if they *can* be peeled, *are*1217 * peeled in this file. References outside of "refs/tags/" are1218 * probably not peeled even if they could have been, but if we find1219 * a peeled value for such a reference we will use it.1220 *1221 * fully-peeled:1222 *1223 * All references in the file that can be peeled are peeled.1224 * Inversely (and this is more important), any references in the1225 * file for which no peeled value is recorded is not peelable. This1226 * trait should typically be written alongside "peeled" for1227 * compatibility with older clients, but we do not require it1228 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1229 */1230static voidread_packed_refs(FILE*f,struct ref_dir *dir)1231{1232struct ref_entry *last = NULL;1233char refline[PATH_MAX];1234enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;12351236while(fgets(refline,sizeof(refline), f)) {1237unsigned char sha1[20];1238const char*refname;1239static const char header[] ="# pack-refs with:";12401241if(!strncmp(refline, header,sizeof(header)-1)) {1242const char*traits = refline +sizeof(header) -1;1243if(strstr(traits," fully-peeled "))1244 peeled = PEELED_FULLY;1245else if(strstr(traits," peeled "))1246 peeled = PEELED_TAGS;1247/* perhaps other traits later as well */1248continue;1249}12501251 refname =parse_ref_line(refline, sha1);1252if(refname) {1253 last =create_ref_entry(refname, sha1, REF_ISPACKED,1);1254if(peeled == PEELED_FULLY ||1255(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1256 last->flag |= REF_KNOWS_PEELED;1257add_ref(dir, last);1258continue;1259}1260if(last &&1261 refline[0] =='^'&&1262strlen(refline) == PEELED_LINE_LENGTH &&1263 refline[PEELED_LINE_LENGTH -1] =='\n'&&1264!get_sha1_hex(refline +1, sha1)) {1265hashcpy(last->u.value.peeled, sha1);1266/*1267 * Regardless of what the file header said,1268 * we definitely know the value of *this*1269 * reference:1270 */1271 last->flag |= REF_KNOWS_PEELED;1272}1273}1274}12751276/*1277 * Get the packed_ref_cache for the specified ref_cache, creating it1278 * if necessary.1279 */1280static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1281{1282const char*packed_refs_file;12831284if(*refs->name)1285 packed_refs_file =git_path_submodule(refs->name,"packed-refs");1286else1287 packed_refs_file =git_path("packed-refs");12881289if(refs->packed &&1290!stat_validity_check(&refs->packed->validity, packed_refs_file))1291clear_packed_ref_cache(refs);12921293if(!refs->packed) {1294FILE*f;12951296 refs->packed =xcalloc(1,sizeof(*refs->packed));1297acquire_packed_ref_cache(refs->packed);1298 refs->packed->root =create_dir_entry(refs,"",0,0);1299 f =fopen(packed_refs_file,"r");1300if(f) {1301stat_validity_update(&refs->packed->validity,fileno(f));1302read_packed_refs(f,get_ref_dir(refs->packed->root));1303fclose(f);1304}1305}1306return refs->packed;1307}13081309static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1310{1311returnget_ref_dir(packed_ref_cache->root);1312}13131314static struct ref_dir *get_packed_refs(struct ref_cache *refs)1315{1316returnget_packed_ref_dir(get_packed_ref_cache(refs));1317}13181319voidadd_packed_ref(const char*refname,const unsigned char*sha1)1320{1321struct packed_ref_cache *packed_ref_cache =1322get_packed_ref_cache(&ref_cache);13231324if(!packed_ref_cache->lock)1325die("internal error: packed refs not locked");1326add_ref(get_packed_ref_dir(packed_ref_cache),1327create_ref_entry(refname, sha1, REF_ISPACKED,1));1328}13291330/*1331 * Read the loose references from the namespace dirname into dir1332 * (without recursing). dirname must end with '/'. dir must be the1333 * directory entry corresponding to dirname.1334 */1335static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1336{1337struct ref_cache *refs = dir->ref_cache;1338DIR*d;1339const char*path;1340struct dirent *de;1341int dirnamelen =strlen(dirname);1342struct strbuf refname;13431344if(*refs->name)1345 path =git_path_submodule(refs->name,"%s", dirname);1346else1347 path =git_path("%s", dirname);13481349 d =opendir(path);1350if(!d)1351return;13521353strbuf_init(&refname, dirnamelen +257);1354strbuf_add(&refname, dirname, dirnamelen);13551356while((de =readdir(d)) != NULL) {1357unsigned char sha1[20];1358struct stat st;1359int flag;1360const char*refdir;13611362if(de->d_name[0] =='.')1363continue;1364if(ends_with(de->d_name,".lock"))1365continue;1366strbuf_addstr(&refname, de->d_name);1367 refdir = *refs->name1368?git_path_submodule(refs->name,"%s", refname.buf)1369:git_path("%s", refname.buf);1370if(stat(refdir, &st) <0) {1371;/* silently ignore */1372}else if(S_ISDIR(st.st_mode)) {1373strbuf_addch(&refname,'/');1374add_entry_to_dir(dir,1375create_dir_entry(refs, refname.buf,1376 refname.len,1));1377}else{1378if(*refs->name) {1379hashclr(sha1);1380 flag =0;1381if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1382hashclr(sha1);1383 flag |= REF_ISBROKEN;1384}1385}else if(read_ref_full(refname.buf, sha1,1, &flag)) {1386hashclr(sha1);1387 flag |= REF_ISBROKEN;1388}1389add_entry_to_dir(dir,1390create_ref_entry(refname.buf, sha1, flag,1));1391}1392strbuf_setlen(&refname, dirnamelen);1393}1394strbuf_release(&refname);1395closedir(d);1396}13971398static struct ref_dir *get_loose_refs(struct ref_cache *refs)1399{1400if(!refs->loose) {1401/*1402 * Mark the top-level directory complete because we1403 * are about to read the only subdirectory that can1404 * hold references:1405 */1406 refs->loose =create_dir_entry(refs,"",0,0);1407/*1408 * Create an incomplete entry for "refs/":1409 */1410add_entry_to_dir(get_ref_dir(refs->loose),1411create_dir_entry(refs,"refs/",5,1));1412}1413returnget_ref_dir(refs->loose);1414}14151416/* We allow "recursive" symbolic refs. Only within reason, though */1417#define MAXDEPTH 51418#define MAXREFLEN (1024)14191420/*1421 * Called by resolve_gitlink_ref_recursive() after it failed to read1422 * from the loose refs in ref_cache refs. Find <refname> in the1423 * packed-refs file for the submodule.1424 */1425static intresolve_gitlink_packed_ref(struct ref_cache *refs,1426const char*refname,unsigned char*sha1)1427{1428struct ref_entry *ref;1429struct ref_dir *dir =get_packed_refs(refs);14301431 ref =find_ref(dir, refname);1432if(ref == NULL)1433return-1;14341435hashcpy(sha1, ref->u.value.sha1);1436return0;1437}14381439static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1440const char*refname,unsigned char*sha1,1441int recursion)1442{1443int fd, len;1444char buffer[128], *p;1445char*path;14461447if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1448return-1;1449 path = *refs->name1450?git_path_submodule(refs->name,"%s", refname)1451:git_path("%s", refname);1452 fd =open(path, O_RDONLY);1453if(fd <0)1454returnresolve_gitlink_packed_ref(refs, refname, sha1);14551456 len =read(fd, buffer,sizeof(buffer)-1);1457close(fd);1458if(len <0)1459return-1;1460while(len &&isspace(buffer[len-1]))1461 len--;1462 buffer[len] =0;14631464/* Was it a detached head or an old-fashioned symlink? */1465if(!get_sha1_hex(buffer, sha1))1466return0;14671468/* Symref? */1469if(strncmp(buffer,"ref:",4))1470return-1;1471 p = buffer +4;1472while(isspace(*p))1473 p++;14741475returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1476}14771478intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1479{1480int len =strlen(path), retval;1481char*submodule;1482struct ref_cache *refs;14831484while(len && path[len-1] =='/')1485 len--;1486if(!len)1487return-1;1488 submodule =xstrndup(path, len);1489 refs =get_ref_cache(submodule);1490free(submodule);14911492 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1493return retval;1494}14951496/*1497 * Return the ref_entry for the given refname from the packed1498 * references. If it does not exist, return NULL.1499 */1500static struct ref_entry *get_packed_ref(const char*refname)1501{1502returnfind_ref(get_packed_refs(&ref_cache), refname);1503}15041505/*1506 * A loose ref file doesn't exist; check for a packed ref. The1507 * options are forwarded from resolve_safe_unsafe().1508 */1509static const char*handle_missing_loose_ref(const char*refname,1510unsigned char*sha1,1511int reading,1512int*flag)1513{1514struct ref_entry *entry;15151516/*1517 * The loose reference file does not exist; check for a packed1518 * reference.1519 */1520 entry =get_packed_ref(refname);1521if(entry) {1522hashcpy(sha1, entry->u.value.sha1);1523if(flag)1524*flag |= REF_ISPACKED;1525return refname;1526}1527/* The reference is not a packed reference, either. */1528if(reading) {1529return NULL;1530}else{1531hashclr(sha1);1532return refname;1533}1534}15351536/* This function needs to return a meaningful errno on failure */1537const char*resolve_ref_unsafe(const char*refname,unsigned char*sha1,int reading,int*flag)1538{1539int depth = MAXDEPTH;1540 ssize_t len;1541char buffer[256];1542static char refname_buffer[256];15431544if(flag)1545*flag =0;15461547if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1548 errno = EINVAL;1549return NULL;1550}15511552for(;;) {1553char path[PATH_MAX];1554struct stat st;1555char*buf;1556int fd;15571558if(--depth <0) {1559 errno = ELOOP;1560return NULL;1561}15621563git_snpath(path,sizeof(path),"%s", refname);15641565/*1566 * We might have to loop back here to avoid a race1567 * condition: first we lstat() the file, then we try1568 * to read it as a link or as a file. But if somebody1569 * changes the type of the file (file <-> directory1570 * <-> symlink) between the lstat() and reading, then1571 * we don't want to report that as an error but rather1572 * try again starting with the lstat().1573 */1574 stat_ref:1575if(lstat(path, &st) <0) {1576if(errno == ENOENT)1577returnhandle_missing_loose_ref(refname, sha1,1578 reading, flag);1579else1580return NULL;1581}15821583/* Follow "normalized" - ie "refs/.." symlinks by hand */1584if(S_ISLNK(st.st_mode)) {1585 len =readlink(path, buffer,sizeof(buffer)-1);1586if(len <0) {1587if(errno == ENOENT || errno == EINVAL)1588/* inconsistent with lstat; retry */1589goto stat_ref;1590else1591return NULL;1592}1593 buffer[len] =0;1594if(starts_with(buffer,"refs/") &&1595!check_refname_format(buffer,0)) {1596strcpy(refname_buffer, buffer);1597 refname = refname_buffer;1598if(flag)1599*flag |= REF_ISSYMREF;1600continue;1601}1602}16031604/* Is it a directory? */1605if(S_ISDIR(st.st_mode)) {1606 errno = EISDIR;1607return NULL;1608}16091610/*1611 * Anything else, just open it and try to use it as1612 * a ref1613 */1614 fd =open(path, O_RDONLY);1615if(fd <0) {1616if(errno == ENOENT)1617/* inconsistent with lstat; retry */1618goto stat_ref;1619else1620return NULL;1621}1622 len =read_in_full(fd, buffer,sizeof(buffer)-1);1623if(len <0) {1624int save_errno = errno;1625close(fd);1626 errno = save_errno;1627return NULL;1628}1629close(fd);1630while(len &&isspace(buffer[len-1]))1631 len--;1632 buffer[len] ='\0';16331634/*1635 * Is it a symbolic ref?1636 */1637if(!starts_with(buffer,"ref:")) {1638/*1639 * Please note that FETCH_HEAD has a second1640 * line containing other data.1641 */1642if(get_sha1_hex(buffer, sha1) ||1643(buffer[40] !='\0'&& !isspace(buffer[40]))) {1644if(flag)1645*flag |= REF_ISBROKEN;1646 errno = EINVAL;1647return NULL;1648}1649return refname;1650}1651if(flag)1652*flag |= REF_ISSYMREF;1653 buf = buffer +4;1654while(isspace(*buf))1655 buf++;1656if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1657if(flag)1658*flag |= REF_ISBROKEN;1659 errno = EINVAL;1660return NULL;1661}1662 refname =strcpy(refname_buffer, buf);1663}1664}16651666char*resolve_refdup(const char*ref,unsigned char*sha1,int reading,int*flag)1667{1668const char*ret =resolve_ref_unsafe(ref, sha1, reading, flag);1669return ret ?xstrdup(ret) : NULL;1670}16711672/* The argument to filter_refs */1673struct ref_filter {1674const char*pattern;1675 each_ref_fn *fn;1676void*cb_data;1677};16781679intread_ref_full(const char*refname,unsigned char*sha1,int reading,int*flags)1680{1681if(resolve_ref_unsafe(refname, sha1, reading, flags))1682return0;1683return-1;1684}16851686intread_ref(const char*refname,unsigned char*sha1)1687{1688returnread_ref_full(refname, sha1,1, NULL);1689}16901691intref_exists(const char*refname)1692{1693unsigned char sha1[20];1694return!!resolve_ref_unsafe(refname, sha1,1, NULL);1695}16961697static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1698void*data)1699{1700struct ref_filter *filter = (struct ref_filter *)data;1701if(wildmatch(filter->pattern, refname,0, NULL))1702return0;1703return filter->fn(refname, sha1, flags, filter->cb_data);1704}17051706enum peel_status {1707/* object was peeled successfully: */1708 PEEL_PEELED =0,17091710/*1711 * object cannot be peeled because the named object (or an1712 * object referred to by a tag in the peel chain), does not1713 * exist.1714 */1715 PEEL_INVALID = -1,17161717/* object cannot be peeled because it is not a tag: */1718 PEEL_NON_TAG = -2,17191720/* ref_entry contains no peeled value because it is a symref: */1721 PEEL_IS_SYMREF = -3,17221723/*1724 * ref_entry cannot be peeled because it is broken (i.e., the1725 * symbolic reference cannot even be resolved to an object1726 * name):1727 */1728 PEEL_BROKEN = -41729};17301731/*1732 * Peel the named object; i.e., if the object is a tag, resolve the1733 * tag recursively until a non-tag is found. If successful, store the1734 * result to sha1 and return PEEL_PEELED. If the object is not a tag1735 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1736 * and leave sha1 unchanged.1737 */1738static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1739{1740struct object *o =lookup_unknown_object(name);17411742if(o->type == OBJ_NONE) {1743int type =sha1_object_info(name, NULL);1744if(type <0)1745return PEEL_INVALID;1746 o->type = type;1747}17481749if(o->type != OBJ_TAG)1750return PEEL_NON_TAG;17511752 o =deref_tag_noverify(o);1753if(!o)1754return PEEL_INVALID;17551756hashcpy(sha1, o->sha1);1757return PEEL_PEELED;1758}17591760/*1761 * Peel the entry (if possible) and return its new peel_status. If1762 * repeel is true, re-peel the entry even if there is an old peeled1763 * value that is already stored in it.1764 *1765 * It is OK to call this function with a packed reference entry that1766 * might be stale and might even refer to an object that has since1767 * been garbage-collected. In such a case, if the entry has1768 * REF_KNOWS_PEELED then leave the status unchanged and return1769 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1770 */1771static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1772{1773enum peel_status status;17741775if(entry->flag & REF_KNOWS_PEELED) {1776if(repeel) {1777 entry->flag &= ~REF_KNOWS_PEELED;1778hashclr(entry->u.value.peeled);1779}else{1780returnis_null_sha1(entry->u.value.peeled) ?1781 PEEL_NON_TAG : PEEL_PEELED;1782}1783}1784if(entry->flag & REF_ISBROKEN)1785return PEEL_BROKEN;1786if(entry->flag & REF_ISSYMREF)1787return PEEL_IS_SYMREF;17881789 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1790if(status == PEEL_PEELED || status == PEEL_NON_TAG)1791 entry->flag |= REF_KNOWS_PEELED;1792return status;1793}17941795intpeel_ref(const char*refname,unsigned char*sha1)1796{1797int flag;1798unsigned char base[20];17991800if(current_ref && (current_ref->name == refname1801|| !strcmp(current_ref->name, refname))) {1802if(peel_entry(current_ref,0))1803return-1;1804hashcpy(sha1, current_ref->u.value.peeled);1805return0;1806}18071808if(read_ref_full(refname, base,1, &flag))1809return-1;18101811/*1812 * If the reference is packed, read its ref_entry from the1813 * cache in the hope that we already know its peeled value.1814 * We only try this optimization on packed references because1815 * (a) forcing the filling of the loose reference cache could1816 * be expensive and (b) loose references anyway usually do not1817 * have REF_KNOWS_PEELED.1818 */1819if(flag & REF_ISPACKED) {1820struct ref_entry *r =get_packed_ref(refname);1821if(r) {1822if(peel_entry(r,0))1823return-1;1824hashcpy(sha1, r->u.value.peeled);1825return0;1826}1827}18281829returnpeel_object(base, sha1);1830}18311832struct warn_if_dangling_data {1833FILE*fp;1834const char*refname;1835const struct string_list *refnames;1836const char*msg_fmt;1837};18381839static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1840int flags,void*cb_data)1841{1842struct warn_if_dangling_data *d = cb_data;1843const char*resolves_to;1844unsigned char junk[20];18451846if(!(flags & REF_ISSYMREF))1847return0;18481849 resolves_to =resolve_ref_unsafe(refname, junk,0, NULL);1850if(!resolves_to1851|| (d->refname1852?strcmp(resolves_to, d->refname)1853: !string_list_has_string(d->refnames, resolves_to))) {1854return0;1855}18561857fprintf(d->fp, d->msg_fmt, refname);1858fputc('\n', d->fp);1859return0;1860}18611862voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1863{1864struct warn_if_dangling_data data;18651866 data.fp = fp;1867 data.refname = refname;1868 data.refnames = NULL;1869 data.msg_fmt = msg_fmt;1870for_each_rawref(warn_if_dangling_symref, &data);1871}18721873voidwarn_dangling_symrefs(FILE*fp,const char*msg_fmt,const struct string_list *refnames)1874{1875struct warn_if_dangling_data data;18761877 data.fp = fp;1878 data.refname = NULL;1879 data.refnames = refnames;1880 data.msg_fmt = msg_fmt;1881for_each_rawref(warn_if_dangling_symref, &data);1882}18831884/*1885 * Call fn for each reference in the specified ref_cache, omitting1886 * references not in the containing_dir of base. fn is called for all1887 * references, including broken ones. If fn ever returns a non-zero1888 * value, stop the iteration and return that value; otherwise, return1889 * 0.1890 */1891static intdo_for_each_entry(struct ref_cache *refs,const char*base,1892 each_ref_entry_fn fn,void*cb_data)1893{1894struct packed_ref_cache *packed_ref_cache;1895struct ref_dir *loose_dir;1896struct ref_dir *packed_dir;1897int retval =0;18981899/*1900 * We must make sure that all loose refs are read before accessing the1901 * packed-refs file; this avoids a race condition in which loose refs1902 * are migrated to the packed-refs file by a simultaneous process, but1903 * our in-memory view is from before the migration. get_packed_ref_cache()1904 * takes care of making sure our view is up to date with what is on1905 * disk.1906 */1907 loose_dir =get_loose_refs(refs);1908if(base && *base) {1909 loose_dir =find_containing_dir(loose_dir, base,0);1910}1911if(loose_dir)1912prime_ref_dir(loose_dir);19131914 packed_ref_cache =get_packed_ref_cache(refs);1915acquire_packed_ref_cache(packed_ref_cache);1916 packed_dir =get_packed_ref_dir(packed_ref_cache);1917if(base && *base) {1918 packed_dir =find_containing_dir(packed_dir, base,0);1919}19201921if(packed_dir && loose_dir) {1922sort_ref_dir(packed_dir);1923sort_ref_dir(loose_dir);1924 retval =do_for_each_entry_in_dirs(1925 packed_dir, loose_dir, fn, cb_data);1926}else if(packed_dir) {1927sort_ref_dir(packed_dir);1928 retval =do_for_each_entry_in_dir(1929 packed_dir,0, fn, cb_data);1930}else if(loose_dir) {1931sort_ref_dir(loose_dir);1932 retval =do_for_each_entry_in_dir(1933 loose_dir,0, fn, cb_data);1934}19351936release_packed_ref_cache(packed_ref_cache);1937return retval;1938}19391940/*1941 * Call fn for each reference in the specified ref_cache for which the1942 * refname begins with base. If trim is non-zero, then trim that many1943 * characters off the beginning of each refname before passing the1944 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1945 * broken references in the iteration. If fn ever returns a non-zero1946 * value, stop the iteration and return that value; otherwise, return1947 * 0.1948 */1949static intdo_for_each_ref(struct ref_cache *refs,const char*base,1950 each_ref_fn fn,int trim,int flags,void*cb_data)1951{1952struct ref_entry_cb data;1953 data.base = base;1954 data.trim = trim;1955 data.flags = flags;1956 data.fn = fn;1957 data.cb_data = cb_data;19581959returndo_for_each_entry(refs, base, do_one_ref, &data);1960}19611962static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1963{1964unsigned char sha1[20];1965int flag;19661967if(submodule) {1968if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1969returnfn("HEAD", sha1,0, cb_data);19701971return0;1972}19731974if(!read_ref_full("HEAD", sha1,1, &flag))1975returnfn("HEAD", sha1, flag, cb_data);19761977return0;1978}19791980inthead_ref(each_ref_fn fn,void*cb_data)1981{1982returndo_head_ref(NULL, fn, cb_data);1983}19841985inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1986{1987returndo_head_ref(submodule, fn, cb_data);1988}19891990intfor_each_ref(each_ref_fn fn,void*cb_data)1991{1992returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1993}19941995intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1996{1997returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1998}19992000intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)2001{2002returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);2003}20042005intfor_each_ref_in_submodule(const char*submodule,const char*prefix,2006 each_ref_fn fn,void*cb_data)2007{2008returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);2009}20102011intfor_each_tag_ref(each_ref_fn fn,void*cb_data)2012{2013returnfor_each_ref_in("refs/tags/", fn, cb_data);2014}20152016intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2017{2018returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);2019}20202021intfor_each_branch_ref(each_ref_fn fn,void*cb_data)2022{2023returnfor_each_ref_in("refs/heads/", fn, cb_data);2024}20252026intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2027{2028returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);2029}20302031intfor_each_remote_ref(each_ref_fn fn,void*cb_data)2032{2033returnfor_each_ref_in("refs/remotes/", fn, cb_data);2034}20352036intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2037{2038returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);2039}20402041intfor_each_replace_ref(each_ref_fn fn,void*cb_data)2042{2043returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);2044}20452046inthead_ref_namespaced(each_ref_fn fn,void*cb_data)2047{2048struct strbuf buf = STRBUF_INIT;2049int ret =0;2050unsigned char sha1[20];2051int flag;20522053strbuf_addf(&buf,"%sHEAD",get_git_namespace());2054if(!read_ref_full(buf.buf, sha1,1, &flag))2055 ret =fn(buf.buf, sha1, flag, cb_data);2056strbuf_release(&buf);20572058return ret;2059}20602061intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)2062{2063struct strbuf buf = STRBUF_INIT;2064int ret;2065strbuf_addf(&buf,"%srefs/",get_git_namespace());2066 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);2067strbuf_release(&buf);2068return ret;2069}20702071intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,2072const char*prefix,void*cb_data)2073{2074struct strbuf real_pattern = STRBUF_INIT;2075struct ref_filter filter;2076int ret;20772078if(!prefix && !starts_with(pattern,"refs/"))2079strbuf_addstr(&real_pattern,"refs/");2080else if(prefix)2081strbuf_addstr(&real_pattern, prefix);2082strbuf_addstr(&real_pattern, pattern);20832084if(!has_glob_specials(pattern)) {2085/* Append implied '/' '*' if not present. */2086if(real_pattern.buf[real_pattern.len -1] !='/')2087strbuf_addch(&real_pattern,'/');2088/* No need to check for '*', there is none. */2089strbuf_addch(&real_pattern,'*');2090}20912092 filter.pattern = real_pattern.buf;2093 filter.fn = fn;2094 filter.cb_data = cb_data;2095 ret =for_each_ref(filter_refs, &filter);20962097strbuf_release(&real_pattern);2098return ret;2099}21002101intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)2102{2103returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);2104}21052106intfor_each_rawref(each_ref_fn fn,void*cb_data)2107{2108returndo_for_each_ref(&ref_cache,"", fn,0,2109 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2110}21112112const char*prettify_refname(const char*name)2113{2114return name + (2115starts_with(name,"refs/heads/") ?11:2116starts_with(name,"refs/tags/") ?10:2117starts_with(name,"refs/remotes/") ?13:21180);2119}21202121static const char*ref_rev_parse_rules[] = {2122"%.*s",2123"refs/%.*s",2124"refs/tags/%.*s",2125"refs/heads/%.*s",2126"refs/remotes/%.*s",2127"refs/remotes/%.*s/HEAD",2128 NULL2129};21302131intrefname_match(const char*abbrev_name,const char*full_name)2132{2133const char**p;2134const int abbrev_name_len =strlen(abbrev_name);21352136for(p = ref_rev_parse_rules; *p; p++) {2137if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {2138return1;2139}2140}21412142return0;2143}21442145/* This function should make sure errno is meaningful on error */2146static struct ref_lock *verify_lock(struct ref_lock *lock,2147const unsigned char*old_sha1,int mustexist)2148{2149if(read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {2150int save_errno = errno;2151error("Can't verify ref%s", lock->ref_name);2152unlock_ref(lock);2153 errno = save_errno;2154return NULL;2155}2156if(hashcmp(lock->old_sha1, old_sha1)) {2157error("Ref%sis at%sbut expected%s", lock->ref_name,2158sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));2159unlock_ref(lock);2160 errno = EBUSY;2161return NULL;2162}2163return lock;2164}21652166static intremove_empty_directories(const char*file)2167{2168/* we want to create a file but there is a directory there;2169 * if that is an empty directory (or a directory that contains2170 * only empty directories), remove them.2171 */2172struct strbuf path;2173int result, save_errno;21742175strbuf_init(&path,20);2176strbuf_addstr(&path, file);21772178 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);2179 save_errno = errno;21802181strbuf_release(&path);2182 errno = save_errno;21832184return result;2185}21862187/*2188 * *string and *len will only be substituted, and *string returned (for2189 * later free()ing) if the string passed in is a magic short-hand form2190 * to name a branch.2191 */2192static char*substitute_branch_name(const char**string,int*len)2193{2194struct strbuf buf = STRBUF_INIT;2195int ret =interpret_branch_name(*string, *len, &buf);21962197if(ret == *len) {2198size_t size;2199*string =strbuf_detach(&buf, &size);2200*len = size;2201return(char*)*string;2202}22032204return NULL;2205}22062207intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)2208{2209char*last_branch =substitute_branch_name(&str, &len);2210const char**p, *r;2211int refs_found =0;22122213*ref = NULL;2214for(p = ref_rev_parse_rules; *p; p++) {2215char fullref[PATH_MAX];2216unsigned char sha1_from_ref[20];2217unsigned char*this_result;2218int flag;22192220 this_result = refs_found ? sha1_from_ref : sha1;2221mksnpath(fullref,sizeof(fullref), *p, len, str);2222 r =resolve_ref_unsafe(fullref, this_result,1, &flag);2223if(r) {2224if(!refs_found++)2225*ref =xstrdup(r);2226if(!warn_ambiguous_refs)2227break;2228}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {2229warning("ignoring dangling symref%s.", fullref);2230}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {2231warning("ignoring broken ref%s.", fullref);2232}2233}2234free(last_branch);2235return refs_found;2236}22372238intdwim_log(const char*str,int len,unsigned char*sha1,char**log)2239{2240char*last_branch =substitute_branch_name(&str, &len);2241const char**p;2242int logs_found =0;22432244*log = NULL;2245for(p = ref_rev_parse_rules; *p; p++) {2246unsigned char hash[20];2247char path[PATH_MAX];2248const char*ref, *it;22492250mksnpath(path,sizeof(path), *p, len, str);2251 ref =resolve_ref_unsafe(path, hash,1, NULL);2252if(!ref)2253continue;2254if(reflog_exists(path))2255 it = path;2256else if(strcmp(ref, path) &&reflog_exists(ref))2257 it = ref;2258else2259continue;2260if(!logs_found++) {2261*log =xstrdup(it);2262hashcpy(sha1, hash);2263}2264if(!warn_ambiguous_refs)2265break;2266}2267free(last_branch);2268return logs_found;2269}22702271/* This function should make sure errno is meaningful on error */2272static struct ref_lock *lock_ref_sha1_basic(const char*refname,2273const unsigned char*old_sha1,2274int flags,int*type_p)2275{2276char*ref_file;2277const char*orig_refname = refname;2278struct ref_lock *lock;2279int last_errno =0;2280int type, lflags;2281int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2282int missing =0;2283int attempts_remaining =3;22842285 lock =xcalloc(1,sizeof(struct ref_lock));2286 lock->lock_fd = -1;22872288 refname =resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);2289if(!refname && errno == EISDIR) {2290/* we are trying to lock foo but we used to2291 * have foo/bar which now does not exist;2292 * it is normal for the empty directory 'foo'2293 * to remain.2294 */2295 ref_file =git_path("%s", orig_refname);2296if(remove_empty_directories(ref_file)) {2297 last_errno = errno;2298error("there are still refs under '%s'", orig_refname);2299goto error_return;2300}2301 refname =resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);2302}2303if(type_p)2304*type_p = type;2305if(!refname) {2306 last_errno = errno;2307error("unable to resolve reference%s:%s",2308 orig_refname,strerror(errno));2309goto error_return;2310}2311 missing =is_null_sha1(lock->old_sha1);2312/* When the ref did not exist and we are creating it,2313 * make sure there is no existing ref that is packed2314 * whose name begins with our refname, nor a ref whose2315 * name is a proper prefix of our refname.2316 */2317if(missing &&2318!is_refname_available(refname, NULL,get_packed_refs(&ref_cache))) {2319 last_errno = ENOTDIR;2320goto error_return;2321}23222323 lock->lk =xcalloc(1,sizeof(struct lock_file));23242325 lflags =0;2326if(flags & REF_NODEREF) {2327 refname = orig_refname;2328 lflags |= LOCK_NODEREF;2329}2330 lock->ref_name =xstrdup(refname);2331 lock->orig_ref_name =xstrdup(orig_refname);2332 ref_file =git_path("%s", refname);2333if(missing)2334 lock->force_write =1;2335if((flags & REF_NODEREF) && (type & REF_ISSYMREF))2336 lock->force_write =1;23372338 retry:2339switch(safe_create_leading_directories(ref_file)) {2340case SCLD_OK:2341break;/* success */2342case SCLD_VANISHED:2343if(--attempts_remaining >0)2344goto retry;2345/* fall through */2346default:2347 last_errno = errno;2348error("unable to create directory for%s", ref_file);2349goto error_return;2350}23512352 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);2353if(lock->lock_fd <0) {2354if(errno == ENOENT && --attempts_remaining >0)2355/*2356 * Maybe somebody just deleted one of the2357 * directories leading to ref_file. Try2358 * again:2359 */2360goto retry;2361else2362unable_to_lock_index_die(ref_file, errno);2363}2364return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;23652366 error_return:2367unlock_ref(lock);2368 errno = last_errno;2369return NULL;2370}23712372struct ref_lock *lock_ref_sha1(const char*refname,const unsigned char*old_sha1)2373{2374char refpath[PATH_MAX];2375if(check_refname_format(refname,0))2376return NULL;2377strcpy(refpath,mkpath("refs/%s", refname));2378returnlock_ref_sha1_basic(refpath, old_sha1,0, NULL);2379}23802381struct ref_lock *lock_any_ref_for_update(const char*refname,2382const unsigned char*old_sha1,2383int flags,int*type_p)2384{2385if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))2386return NULL;2387returnlock_ref_sha1_basic(refname, old_sha1, flags, type_p);2388}23892390/*2391 * Write an entry to the packed-refs file for the specified refname.2392 * If peeled is non-NULL, write it as the entry's peeled value.2393 */2394static voidwrite_packed_entry(int fd,char*refname,unsigned char*sha1,2395unsigned char*peeled)2396{2397char line[PATH_MAX +100];2398int len;23992400 len =snprintf(line,sizeof(line),"%s %s\n",2401sha1_to_hex(sha1), refname);2402/* this should not happen but just being defensive */2403if(len >sizeof(line))2404die("too long a refname '%s'", refname);2405write_or_die(fd, line, len);24062407if(peeled) {2408if(snprintf(line,sizeof(line),"^%s\n",2409sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)2410die("internal error");2411write_or_die(fd, line, PEELED_LINE_LENGTH);2412}2413}24142415/*2416 * An each_ref_entry_fn that writes the entry to a packed-refs file.2417 */2418static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2419{2420int*fd = cb_data;2421enum peel_status peel_status =peel_entry(entry,0);24222423if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2424error("internal error:%sis not a valid packed reference!",2425 entry->name);2426write_packed_entry(*fd, entry->name, entry->u.value.sha1,2427 peel_status == PEEL_PEELED ?2428 entry->u.value.peeled : NULL);2429return0;2430}24312432/* This should return a meaningful errno on failure */2433intlock_packed_refs(int flags)2434{2435struct packed_ref_cache *packed_ref_cache;24362437if(hold_lock_file_for_update(&packlock,git_path("packed-refs"), flags) <0)2438return-1;2439/*2440 * Get the current packed-refs while holding the lock. If the2441 * packed-refs file has been modified since we last read it,2442 * this will automatically invalidate the cache and re-read2443 * the packed-refs file.2444 */2445 packed_ref_cache =get_packed_ref_cache(&ref_cache);2446 packed_ref_cache->lock = &packlock;2447/* Increment the reference count to prevent it from being freed: */2448acquire_packed_ref_cache(packed_ref_cache);2449return0;2450}24512452/*2453 * Commit the packed refs changes.2454 * On error we must make sure that errno contains a meaningful value.2455 */2456intcommit_packed_refs(void)2457{2458struct packed_ref_cache *packed_ref_cache =2459get_packed_ref_cache(&ref_cache);2460int error =0;2461int save_errno =0;24622463if(!packed_ref_cache->lock)2464die("internal error: packed-refs not locked");2465write_or_die(packed_ref_cache->lock->fd,2466 PACKED_REFS_HEADER,strlen(PACKED_REFS_HEADER));24672468do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),24690, write_packed_entry_fn,2470&packed_ref_cache->lock->fd);2471if(commit_lock_file(packed_ref_cache->lock)) {2472 save_errno = errno;2473 error = -1;2474}2475 packed_ref_cache->lock = NULL;2476release_packed_ref_cache(packed_ref_cache);2477 errno = save_errno;2478return error;2479}24802481voidrollback_packed_refs(void)2482{2483struct packed_ref_cache *packed_ref_cache =2484get_packed_ref_cache(&ref_cache);24852486if(!packed_ref_cache->lock)2487die("internal error: packed-refs not locked");2488rollback_lock_file(packed_ref_cache->lock);2489 packed_ref_cache->lock = NULL;2490release_packed_ref_cache(packed_ref_cache);2491clear_packed_ref_cache(&ref_cache);2492}24932494struct ref_to_prune {2495struct ref_to_prune *next;2496unsigned char sha1[20];2497char name[FLEX_ARRAY];2498};24992500struct pack_refs_cb_data {2501unsigned int flags;2502struct ref_dir *packed_refs;2503struct ref_to_prune *ref_to_prune;2504};25052506/*2507 * An each_ref_entry_fn that is run over loose references only. If2508 * the loose reference can be packed, add an entry in the packed ref2509 * cache. If the reference should be pruned, also add it to2510 * ref_to_prune in the pack_refs_cb_data.2511 */2512static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2513{2514struct pack_refs_cb_data *cb = cb_data;2515enum peel_status peel_status;2516struct ref_entry *packed_entry;2517int is_tag_ref =starts_with(entry->name,"refs/tags/");25182519/* ALWAYS pack tags */2520if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2521return0;25222523/* Do not pack symbolic or broken refs: */2524if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2525return0;25262527/* Add a packed ref cache entry equivalent to the loose entry. */2528 peel_status =peel_entry(entry,1);2529if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2530die("internal error peeling reference%s(%s)",2531 entry->name,sha1_to_hex(entry->u.value.sha1));2532 packed_entry =find_ref(cb->packed_refs, entry->name);2533if(packed_entry) {2534/* Overwrite existing packed entry with info from loose entry */2535 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2536hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2537}else{2538 packed_entry =create_ref_entry(entry->name, entry->u.value.sha1,2539 REF_ISPACKED | REF_KNOWS_PEELED,0);2540add_ref(cb->packed_refs, packed_entry);2541}2542hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);25432544/* Schedule the loose reference for pruning if requested. */2545if((cb->flags & PACK_REFS_PRUNE)) {2546int namelen =strlen(entry->name) +1;2547struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2548hashcpy(n->sha1, entry->u.value.sha1);2549strcpy(n->name, entry->name);2550 n->next = cb->ref_to_prune;2551 cb->ref_to_prune = n;2552}2553return0;2554}25552556/*2557 * Remove empty parents, but spare refs/ and immediate subdirs.2558 * Note: munges *name.2559 */2560static voidtry_remove_empty_parents(char*name)2561{2562char*p, *q;2563int i;2564 p = name;2565for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2566while(*p && *p !='/')2567 p++;2568/* tolerate duplicate slashes; see check_refname_format() */2569while(*p =='/')2570 p++;2571}2572for(q = p; *q; q++)2573;2574while(1) {2575while(q > p && *q !='/')2576 q--;2577while(q > p && *(q-1) =='/')2578 q--;2579if(q == p)2580break;2581*q ='\0';2582if(rmdir(git_path("%s", name)))2583break;2584}2585}25862587/* make sure nobody touched the ref, and unlink */2588static voidprune_ref(struct ref_to_prune *r)2589{2590struct ref_lock *lock =lock_ref_sha1(r->name +5, r->sha1);25912592if(lock) {2593unlink_or_warn(git_path("%s", r->name));2594unlock_ref(lock);2595try_remove_empty_parents(r->name);2596}2597}25982599static voidprune_refs(struct ref_to_prune *r)2600{2601while(r) {2602prune_ref(r);2603 r = r->next;2604}2605}26062607intpack_refs(unsigned int flags)2608{2609struct pack_refs_cb_data cbdata;26102611memset(&cbdata,0,sizeof(cbdata));2612 cbdata.flags = flags;26132614lock_packed_refs(LOCK_DIE_ON_ERROR);2615 cbdata.packed_refs =get_packed_refs(&ref_cache);26162617do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2618 pack_if_possible_fn, &cbdata);26192620if(commit_packed_refs())2621die_errno("unable to overwrite old ref-pack file");26222623prune_refs(cbdata.ref_to_prune);2624return0;2625}26262627/*2628 * If entry is no longer needed in packed-refs, add it to the string2629 * list pointed to by cb_data. Reasons for deleting entries:2630 *2631 * - Entry is broken.2632 * - Entry is overridden by a loose ref.2633 * - Entry does not point at a valid object.2634 *2635 * In the first and third cases, also emit an error message because these2636 * are indications of repository corruption.2637 */2638static intcurate_packed_ref_fn(struct ref_entry *entry,void*cb_data)2639{2640struct string_list *refs_to_delete = cb_data;26412642if(entry->flag & REF_ISBROKEN) {2643/* This shouldn't happen to packed refs. */2644error("%sis broken!", entry->name);2645string_list_append(refs_to_delete, entry->name);2646return0;2647}2648if(!has_sha1_file(entry->u.value.sha1)) {2649unsigned char sha1[20];2650int flags;26512652if(read_ref_full(entry->name, sha1,0, &flags))2653/* We should at least have found the packed ref. */2654die("Internal error");2655if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2656/*2657 * This packed reference is overridden by a2658 * loose reference, so it is OK that its value2659 * is no longer valid; for example, it might2660 * refer to an object that has been garbage2661 * collected. For this purpose we don't even2662 * care whether the loose reference itself is2663 * invalid, broken, symbolic, etc. Silently2664 * remove the packed reference.2665 */2666string_list_append(refs_to_delete, entry->name);2667return0;2668}2669/*2670 * There is no overriding loose reference, so the fact2671 * that this reference doesn't refer to a valid object2672 * indicates some kind of repository corruption.2673 * Report the problem, then omit the reference from2674 * the output.2675 */2676error("%sdoes not point to a valid object!", entry->name);2677string_list_append(refs_to_delete, entry->name);2678return0;2679}26802681return0;2682}26832684intrepack_without_refs(const char**refnames,int n,struct strbuf *err)2685{2686struct ref_dir *packed;2687struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2688struct string_list_item *ref_to_delete;2689int i, ret, removed =0;26902691/* Look for a packed ref */2692for(i =0; i < n; i++)2693if(get_packed_ref(refnames[i]))2694break;26952696/* Avoid locking if we have nothing to do */2697if(i == n)2698return0;/* no refname exists in packed refs */26992700if(lock_packed_refs(0)) {2701if(err) {2702unable_to_lock_message(git_path("packed-refs"), errno,2703 err);2704return-1;2705}2706unable_to_lock_error(git_path("packed-refs"), errno);2707returnerror("cannot delete '%s' from packed refs", refnames[i]);2708}2709 packed =get_packed_refs(&ref_cache);27102711/* Remove refnames from the cache */2712for(i =0; i < n; i++)2713if(remove_entry(packed, refnames[i]) != -1)2714 removed =1;2715if(!removed) {2716/*2717 * All packed entries disappeared while we were2718 * acquiring the lock.2719 */2720rollback_packed_refs();2721return0;2722}27232724/* Remove any other accumulated cruft */2725do_for_each_entry_in_dir(packed,0, curate_packed_ref_fn, &refs_to_delete);2726for_each_string_list_item(ref_to_delete, &refs_to_delete) {2727if(remove_entry(packed, ref_to_delete->string) == -1)2728die("internal error");2729}27302731/* Write what remains */2732 ret =commit_packed_refs();2733if(ret && err)2734strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2735strerror(errno));2736return ret;2737}27382739static intrepack_without_ref(const char*refname)2740{2741returnrepack_without_refs(&refname,1, NULL);2742}27432744static intdelete_ref_loose(struct ref_lock *lock,int flag)2745{2746if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2747/* loose */2748int err, i =strlen(lock->lk->filename) -5;/* .lock */27492750 lock->lk->filename[i] =0;2751 err =unlink_or_warn(lock->lk->filename);2752 lock->lk->filename[i] ='.';2753if(err && errno != ENOENT)2754return1;2755}2756return0;2757}27582759intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2760{2761struct ref_lock *lock;2762int ret =0, flag =0;27632764 lock =lock_ref_sha1_basic(refname, sha1, delopt, &flag);2765if(!lock)2766return1;2767 ret |=delete_ref_loose(lock, flag);27682769/* removing the loose one could have resurrected an earlier2770 * packed one. Also, if it was not loose we need to repack2771 * without it.2772 */2773 ret |=repack_without_ref(lock->ref_name);27742775unlink_or_warn(git_path("logs/%s", lock->ref_name));2776clear_loose_ref_cache(&ref_cache);2777unlock_ref(lock);2778return ret;2779}27802781/*2782 * People using contrib's git-new-workdir have .git/logs/refs ->2783 * /some/other/path/.git/logs/refs, and that may live on another device.2784 *2785 * IOW, to avoid cross device rename errors, the temporary renamed log must2786 * live into logs/refs.2787 */2788#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"27892790static intrename_tmp_log(const char*newrefname)2791{2792int attempts_remaining =4;27932794 retry:2795switch(safe_create_leading_directories(git_path("logs/%s", newrefname))) {2796case SCLD_OK:2797break;/* success */2798case SCLD_VANISHED:2799if(--attempts_remaining >0)2800goto retry;2801/* fall through */2802default:2803error("unable to create directory for%s", newrefname);2804return-1;2805}28062807if(rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2808if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2809/*2810 * rename(a, b) when b is an existing2811 * directory ought to result in ISDIR, but2812 * Solaris 5.8 gives ENOTDIR. Sheesh.2813 */2814if(remove_empty_directories(git_path("logs/%s", newrefname))) {2815error("Directory not empty: logs/%s", newrefname);2816return-1;2817}2818goto retry;2819}else if(errno == ENOENT && --attempts_remaining >0) {2820/*2821 * Maybe another process just deleted one of2822 * the directories in the path to newrefname.2823 * Try again from the beginning.2824 */2825goto retry;2826}else{2827error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2828 newrefname,strerror(errno));2829return-1;2830}2831}2832return0;2833}28342835intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2836{2837unsigned char sha1[20], orig_sha1[20];2838int flag =0, logmoved =0;2839struct ref_lock *lock;2840struct stat loginfo;2841int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2842const char*symref = NULL;28432844if(log &&S_ISLNK(loginfo.st_mode))2845returnerror("reflog for%sis a symlink", oldrefname);28462847 symref =resolve_ref_unsafe(oldrefname, orig_sha1,1, &flag);2848if(flag & REF_ISSYMREF)2849returnerror("refname%sis a symbolic ref, renaming it is not supported",2850 oldrefname);2851if(!symref)2852returnerror("refname%snot found", oldrefname);28532854if(!is_refname_available(newrefname, oldrefname,get_packed_refs(&ref_cache)))2855return1;28562857if(!is_refname_available(newrefname, oldrefname,get_loose_refs(&ref_cache)))2858return1;28592860if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2861returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2862 oldrefname,strerror(errno));28632864if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2865error("unable to delete old%s", oldrefname);2866goto rollback;2867}28682869if(!read_ref_full(newrefname, sha1,1, &flag) &&2870delete_ref(newrefname, sha1, REF_NODEREF)) {2871if(errno==EISDIR) {2872if(remove_empty_directories(git_path("%s", newrefname))) {2873error("Directory not empty:%s", newrefname);2874goto rollback;2875}2876}else{2877error("unable to delete existing%s", newrefname);2878goto rollback;2879}2880}28812882if(log &&rename_tmp_log(newrefname))2883goto rollback;28842885 logmoved = log;28862887 lock =lock_ref_sha1_basic(newrefname, NULL,0, NULL);2888if(!lock) {2889error("unable to lock%sfor update", newrefname);2890goto rollback;2891}2892 lock->force_write =1;2893hashcpy(lock->old_sha1, orig_sha1);2894if(write_ref_sha1(lock, orig_sha1, logmsg)) {2895error("unable to write current sha1 into%s", newrefname);2896goto rollback;2897}28982899return0;29002901 rollback:2902 lock =lock_ref_sha1_basic(oldrefname, NULL,0, NULL);2903if(!lock) {2904error("unable to lock%sfor rollback", oldrefname);2905goto rollbacklog;2906}29072908 lock->force_write =1;2909 flag = log_all_ref_updates;2910 log_all_ref_updates =0;2911if(write_ref_sha1(lock, orig_sha1, NULL))2912error("unable to write current sha1 into%s", oldrefname);2913 log_all_ref_updates = flag;29142915 rollbacklog:2916if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2917error("unable to restore logfile%sfrom%s:%s",2918 oldrefname, newrefname,strerror(errno));2919if(!logmoved && log &&2920rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2921error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2922 oldrefname,strerror(errno));29232924return1;2925}29262927intclose_ref(struct ref_lock *lock)2928{2929if(close_lock_file(lock->lk))2930return-1;2931 lock->lock_fd = -1;2932return0;2933}29342935intcommit_ref(struct ref_lock *lock)2936{2937if(commit_lock_file(lock->lk))2938return-1;2939 lock->lock_fd = -1;2940return0;2941}29422943voidunlock_ref(struct ref_lock *lock)2944{2945/* Do not free lock->lk -- atexit() still looks at them */2946if(lock->lk)2947rollback_lock_file(lock->lk);2948free(lock->ref_name);2949free(lock->orig_ref_name);2950free(lock);2951}29522953/*2954 * copy the reflog message msg to buf, which has been allocated sufficiently2955 * large, while cleaning up the whitespaces. Especially, convert LF to space,2956 * because reflog file is one line per entry.2957 */2958static intcopy_msg(char*buf,const char*msg)2959{2960char*cp = buf;2961char c;2962int wasspace =1;29632964*cp++ ='\t';2965while((c = *msg++)) {2966if(wasspace &&isspace(c))2967continue;2968 wasspace =isspace(c);2969if(wasspace)2970 c =' ';2971*cp++ = c;2972}2973while(buf < cp &&isspace(cp[-1]))2974 cp--;2975*cp++ ='\n';2976return cp - buf;2977}29782979/* This function must set a meaningful errno on failure */2980intlog_ref_setup(const char*refname,char*logfile,int bufsize)2981{2982int logfd, oflags = O_APPEND | O_WRONLY;29832984git_snpath(logfile, bufsize,"logs/%s", refname);2985if(log_all_ref_updates &&2986(starts_with(refname,"refs/heads/") ||2987starts_with(refname,"refs/remotes/") ||2988starts_with(refname,"refs/notes/") ||2989!strcmp(refname,"HEAD"))) {2990if(safe_create_leading_directories(logfile) <0) {2991int save_errno = errno;2992error("unable to create directory for%s", logfile);2993 errno = save_errno;2994return-1;2995}2996 oflags |= O_CREAT;2997}29982999 logfd =open(logfile, oflags,0666);3000if(logfd <0) {3001if(!(oflags & O_CREAT) && errno == ENOENT)3002return0;30033004if((oflags & O_CREAT) && errno == EISDIR) {3005if(remove_empty_directories(logfile)) {3006int save_errno = errno;3007error("There are still logs under '%s'",3008 logfile);3009 errno = save_errno;3010return-1;3011}3012 logfd =open(logfile, oflags,0666);3013}30143015if(logfd <0) {3016int save_errno = errno;3017error("Unable to append to%s:%s", logfile,3018strerror(errno));3019 errno = save_errno;3020return-1;3021}3022}30233024adjust_shared_perm(logfile);3025close(logfd);3026return0;3027}30283029static intlog_ref_write(const char*refname,const unsigned char*old_sha1,3030const unsigned char*new_sha1,const char*msg)3031{3032int logfd, result, written, oflags = O_APPEND | O_WRONLY;3033unsigned maxlen, len;3034int msglen;3035char log_file[PATH_MAX];3036char*logrec;3037const char*committer;30383039if(log_all_ref_updates <0)3040 log_all_ref_updates = !is_bare_repository();30413042 result =log_ref_setup(refname, log_file,sizeof(log_file));3043if(result)3044return result;30453046 logfd =open(log_file, oflags);3047if(logfd <0)3048return0;3049 msglen = msg ?strlen(msg) :0;3050 committer =git_committer_info(0);3051 maxlen =strlen(committer) + msglen +100;3052 logrec =xmalloc(maxlen);3053 len =sprintf(logrec,"%s %s %s\n",3054sha1_to_hex(old_sha1),3055sha1_to_hex(new_sha1),3056 committer);3057if(msglen)3058 len +=copy_msg(logrec + len -1, msg) -1;3059 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;3060free(logrec);3061if(written != len) {3062int save_errno = errno;3063close(logfd);3064error("Unable to append to%s", log_file);3065 errno = save_errno;3066return-1;3067}3068if(close(logfd)) {3069int save_errno = errno;3070error("Unable to append to%s", log_file);3071 errno = save_errno;3072return-1;3073}3074return0;3075}30763077static intis_branch(const char*refname)3078{3079return!strcmp(refname,"HEAD") ||starts_with(refname,"refs/heads/");3080}30813082/* This function must return a meaningful errno */3083intwrite_ref_sha1(struct ref_lock *lock,3084const unsigned char*sha1,const char*logmsg)3085{3086static char term ='\n';3087struct object *o;30883089if(!lock) {3090 errno = EINVAL;3091return-1;3092}3093if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {3094unlock_ref(lock);3095return0;3096}3097 o =parse_object(sha1);3098if(!o) {3099error("Trying to write ref%swith nonexistent object%s",3100 lock->ref_name,sha1_to_hex(sha1));3101unlock_ref(lock);3102 errno = EINVAL;3103return-1;3104}3105if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {3106error("Trying to write non-commit object%sto branch%s",3107sha1_to_hex(sha1), lock->ref_name);3108unlock_ref(lock);3109 errno = EINVAL;3110return-1;3111}3112if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||3113write_in_full(lock->lock_fd, &term,1) !=1||3114close_ref(lock) <0) {3115int save_errno = errno;3116error("Couldn't write%s", lock->lk->filename);3117unlock_ref(lock);3118 errno = save_errno;3119return-1;3120}3121clear_loose_ref_cache(&ref_cache);3122if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||3123(strcmp(lock->ref_name, lock->orig_ref_name) &&3124log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {3125unlock_ref(lock);3126return-1;3127}3128if(strcmp(lock->orig_ref_name,"HEAD") !=0) {3129/*3130 * Special hack: If a branch is updated directly and HEAD3131 * points to it (may happen on the remote side of a push3132 * for example) then logically the HEAD reflog should be3133 * updated too.3134 * A generic solution implies reverse symref information,3135 * but finding all symrefs pointing to the given branch3136 * would be rather costly for this rare event (the direct3137 * update of a branch) to be worth it. So let's cheat and3138 * check with HEAD only which should cover 99% of all usage3139 * scenarios (even 100% of the default ones).3140 */3141unsigned char head_sha1[20];3142int head_flag;3143const char*head_ref;3144 head_ref =resolve_ref_unsafe("HEAD", head_sha1,1, &head_flag);3145if(head_ref && (head_flag & REF_ISSYMREF) &&3146!strcmp(head_ref, lock->ref_name))3147log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3148}3149if(commit_ref(lock)) {3150error("Couldn't set%s", lock->ref_name);3151unlock_ref(lock);3152return-1;3153}3154unlock_ref(lock);3155return0;3156}31573158intcreate_symref(const char*ref_target,const char*refs_heads_master,3159const char*logmsg)3160{3161const char*lockpath;3162char ref[1000];3163int fd, len, written;3164char*git_HEAD =git_pathdup("%s", ref_target);3165unsigned char old_sha1[20], new_sha1[20];31663167if(logmsg &&read_ref(ref_target, old_sha1))3168hashclr(old_sha1);31693170if(safe_create_leading_directories(git_HEAD) <0)3171returnerror("unable to create directory for%s", git_HEAD);31723173#ifndef NO_SYMLINK_HEAD3174if(prefer_symlink_refs) {3175unlink(git_HEAD);3176if(!symlink(refs_heads_master, git_HEAD))3177goto done;3178fprintf(stderr,"no symlink - falling back to symbolic ref\n");3179}3180#endif31813182 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);3183if(sizeof(ref) <= len) {3184error("refname too long:%s", refs_heads_master);3185goto error_free_return;3186}3187 lockpath =mkpath("%s.lock", git_HEAD);3188 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);3189if(fd <0) {3190error("Unable to open%sfor writing", lockpath);3191goto error_free_return;3192}3193 written =write_in_full(fd, ref, len);3194if(close(fd) !=0|| written != len) {3195error("Unable to write to%s", lockpath);3196goto error_unlink_return;3197}3198if(rename(lockpath, git_HEAD) <0) {3199error("Unable to create%s", git_HEAD);3200goto error_unlink_return;3201}3202if(adjust_shared_perm(git_HEAD)) {3203error("Unable to fix permissions on%s", lockpath);3204 error_unlink_return:3205unlink_or_warn(lockpath);3206 error_free_return:3207free(git_HEAD);3208return-1;3209}32103211#ifndef NO_SYMLINK_HEAD3212 done:3213#endif3214if(logmsg && !read_ref(refs_heads_master, new_sha1))3215log_ref_write(ref_target, old_sha1, new_sha1, logmsg);32163217free(git_HEAD);3218return0;3219}32203221struct read_ref_at_cb {3222const char*refname;3223unsigned long at_time;3224int cnt;3225int reccnt;3226unsigned char*sha1;3227int found_it;32283229unsigned char osha1[20];3230unsigned char nsha1[20];3231int tz;3232unsigned long date;3233char**msg;3234unsigned long*cutoff_time;3235int*cutoff_tz;3236int*cutoff_cnt;3237};32383239static intread_ref_at_ent(unsigned char*osha1,unsigned char*nsha1,3240const char*email,unsigned long timestamp,int tz,3241const char*message,void*cb_data)3242{3243struct read_ref_at_cb *cb = cb_data;32443245 cb->reccnt++;3246 cb->tz = tz;3247 cb->date = timestamp;32483249if(timestamp <= cb->at_time || cb->cnt ==0) {3250if(cb->msg)3251*cb->msg =xstrdup(message);3252if(cb->cutoff_time)3253*cb->cutoff_time = timestamp;3254if(cb->cutoff_tz)3255*cb->cutoff_tz = tz;3256if(cb->cutoff_cnt)3257*cb->cutoff_cnt = cb->reccnt -1;3258/*3259 * we have not yet updated cb->[n|o]sha1 so they still3260 * hold the values for the previous record.3261 */3262if(!is_null_sha1(cb->osha1)) {3263hashcpy(cb->sha1, nsha1);3264if(hashcmp(cb->osha1, nsha1))3265warning("Log for ref%shas gap after%s.",3266 cb->refname,show_date(cb->date, cb->tz, DATE_RFC2822));3267}3268else if(cb->date == cb->at_time)3269hashcpy(cb->sha1, nsha1);3270else if(hashcmp(nsha1, cb->sha1))3271warning("Log for ref%sunexpectedly ended on%s.",3272 cb->refname,show_date(cb->date, cb->tz,3273 DATE_RFC2822));3274hashcpy(cb->osha1, osha1);3275hashcpy(cb->nsha1, nsha1);3276 cb->found_it =1;3277return1;3278}3279hashcpy(cb->osha1, osha1);3280hashcpy(cb->nsha1, nsha1);3281if(cb->cnt >0)3282 cb->cnt--;3283return0;3284}32853286static intread_ref_at_ent_oldest(unsigned char*osha1,unsigned char*nsha1,3287const char*email,unsigned long timestamp,3288int tz,const char*message,void*cb_data)3289{3290struct read_ref_at_cb *cb = cb_data;32913292if(cb->msg)3293*cb->msg =xstrdup(message);3294if(cb->cutoff_time)3295*cb->cutoff_time = timestamp;3296if(cb->cutoff_tz)3297*cb->cutoff_tz = tz;3298if(cb->cutoff_cnt)3299*cb->cutoff_cnt = cb->reccnt;3300hashcpy(cb->sha1, osha1);3301if(is_null_sha1(cb->sha1))3302hashcpy(cb->sha1, nsha1);3303/* We just want the first entry */3304return1;3305}33063307intread_ref_at(const char*refname,unsigned long at_time,int cnt,3308unsigned char*sha1,char**msg,3309unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)3310{3311struct read_ref_at_cb cb;33123313memset(&cb,0,sizeof(cb));3314 cb.refname = refname;3315 cb.at_time = at_time;3316 cb.cnt = cnt;3317 cb.msg = msg;3318 cb.cutoff_time = cutoff_time;3319 cb.cutoff_tz = cutoff_tz;3320 cb.cutoff_cnt = cutoff_cnt;3321 cb.sha1 = sha1;33223323for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);33243325if(!cb.reccnt)3326die("Log for%sis empty.", refname);3327if(cb.found_it)3328return0;33293330for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);33313332return1;3333}33343335intreflog_exists(const char*refname)3336{3337struct stat st;33383339return!lstat(git_path("logs/%s", refname), &st) &&3340S_ISREG(st.st_mode);3341}33423343intdelete_reflog(const char*refname)3344{3345returnremove_path(git_path("logs/%s", refname));3346}33473348static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3349{3350unsigned char osha1[20], nsha1[20];3351char*email_end, *message;3352unsigned long timestamp;3353int tz;33543355/* old SP new SP name <email> SP time TAB msg LF */3356if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3357get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3358get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3359!(email_end =strchr(sb->buf +82,'>')) ||3360 email_end[1] !=' '||3361!(timestamp =strtoul(email_end +2, &message,10)) ||3362!message || message[0] !=' '||3363(message[1] !='+'&& message[1] !='-') ||3364!isdigit(message[2]) || !isdigit(message[3]) ||3365!isdigit(message[4]) || !isdigit(message[5]))3366return0;/* corrupt? */3367 email_end[1] ='\0';3368 tz =strtol(message +1, NULL,10);3369if(message[6] !='\t')3370 message +=6;3371else3372 message +=7;3373returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3374}33753376static char*find_beginning_of_line(char*bob,char*scan)3377{3378while(bob < scan && *(--scan) !='\n')3379;/* keep scanning backwards */3380/*3381 * Return either beginning of the buffer, or LF at the end of3382 * the previous line.3383 */3384return scan;3385}33863387intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3388{3389struct strbuf sb = STRBUF_INIT;3390FILE*logfp;3391long pos;3392int ret =0, at_tail =1;33933394 logfp =fopen(git_path("logs/%s", refname),"r");3395if(!logfp)3396return-1;33973398/* Jump to the end */3399if(fseek(logfp,0, SEEK_END) <0)3400returnerror("cannot seek back reflog for%s:%s",3401 refname,strerror(errno));3402 pos =ftell(logfp);3403while(!ret &&0< pos) {3404int cnt;3405size_t nread;3406char buf[BUFSIZ];3407char*endp, *scanp;34083409/* Fill next block from the end */3410 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3411if(fseek(logfp, pos - cnt, SEEK_SET))3412returnerror("cannot seek back reflog for%s:%s",3413 refname,strerror(errno));3414 nread =fread(buf, cnt,1, logfp);3415if(nread !=1)3416returnerror("cannot read%dbytes from reflog for%s:%s",3417 cnt, refname,strerror(errno));3418 pos -= cnt;34193420 scanp = endp = buf + cnt;3421if(at_tail && scanp[-1] =='\n')3422/* Looking at the final LF at the end of the file */3423 scanp--;3424 at_tail =0;34253426while(buf < scanp) {3427/*3428 * terminating LF of the previous line, or the beginning3429 * of the buffer.3430 */3431char*bp;34323433 bp =find_beginning_of_line(buf, scanp);34343435if(*bp !='\n') {3436strbuf_splice(&sb,0,0, buf, endp - buf);3437if(pos)3438break;/* need to fill another block */3439 scanp = buf -1;/* leave loop */3440}else{3441/*3442 * (bp + 1) thru endp is the beginning of the3443 * current line we have in sb3444 */3445strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3446 scanp = bp;3447 endp = bp +1;3448}3449 ret =show_one_reflog_ent(&sb, fn, cb_data);3450strbuf_reset(&sb);3451if(ret)3452break;3453}34543455}3456if(!ret && sb.len)3457 ret =show_one_reflog_ent(&sb, fn, cb_data);34583459fclose(logfp);3460strbuf_release(&sb);3461return ret;3462}34633464intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3465{3466FILE*logfp;3467struct strbuf sb = STRBUF_INIT;3468int ret =0;34693470 logfp =fopen(git_path("logs/%s", refname),"r");3471if(!logfp)3472return-1;34733474while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3475 ret =show_one_reflog_ent(&sb, fn, cb_data);3476fclose(logfp);3477strbuf_release(&sb);3478return ret;3479}3480/*3481 * Call fn for each reflog in the namespace indicated by name. name3482 * must be empty or end with '/'. Name will be used as a scratch3483 * space, but its contents will be restored before return.3484 */3485static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3486{3487DIR*d =opendir(git_path("logs/%s", name->buf));3488int retval =0;3489struct dirent *de;3490int oldlen = name->len;34913492if(!d)3493return name->len ? errno :0;34943495while((de =readdir(d)) != NULL) {3496struct stat st;34973498if(de->d_name[0] =='.')3499continue;3500if(ends_with(de->d_name,".lock"))3501continue;3502strbuf_addstr(name, de->d_name);3503if(stat(git_path("logs/%s", name->buf), &st) <0) {3504;/* silently ignore */3505}else{3506if(S_ISDIR(st.st_mode)) {3507strbuf_addch(name,'/');3508 retval =do_for_each_reflog(name, fn, cb_data);3509}else{3510unsigned char sha1[20];3511if(read_ref_full(name->buf, sha1,0, NULL))3512 retval =error("bad ref for%s", name->buf);3513else3514 retval =fn(name->buf, sha1,0, cb_data);3515}3516if(retval)3517break;3518}3519strbuf_setlen(name, oldlen);3520}3521closedir(d);3522return retval;3523}35243525intfor_each_reflog(each_ref_fn fn,void*cb_data)3526{3527int retval;3528struct strbuf name;3529strbuf_init(&name, PATH_MAX);3530 retval =do_for_each_reflog(&name, fn, cb_data);3531strbuf_release(&name);3532return retval;3533}35343535static struct ref_lock *update_ref_lock(const char*refname,3536const unsigned char*oldval,3537int flags,int*type_p,3538enum action_on_err onerr)3539{3540struct ref_lock *lock;3541 lock =lock_any_ref_for_update(refname, oldval, flags, type_p);3542if(!lock) {3543const char*str ="Cannot lock the ref '%s'.";3544switch(onerr) {3545case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3546case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3547case UPDATE_REFS_QUIET_ON_ERR:break;3548}3549}3550return lock;3551}35523553static intupdate_ref_write(const char*action,const char*refname,3554const unsigned char*sha1,struct ref_lock *lock,3555struct strbuf *err,enum action_on_err onerr)3556{3557if(write_ref_sha1(lock, sha1, action) <0) {3558const char*str ="Cannot update the ref '%s'.";3559if(err)3560strbuf_addf(err, str, refname);35613562switch(onerr) {3563case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3564case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3565case UPDATE_REFS_QUIET_ON_ERR:break;3566}3567return1;3568}3569return0;3570}35713572/**3573 * Information needed for a single ref update. Set new_sha1 to the3574 * new value or to zero to delete the ref. To check the old value3575 * while locking the ref, set have_old to 1 and set old_sha1 to the3576 * value or to zero to ensure the ref does not exist before update.3577 */3578struct ref_update {3579unsigned char new_sha1[20];3580unsigned char old_sha1[20];3581int flags;/* REF_NODEREF? */3582int have_old;/* 1 if old_sha1 is valid, 0 otherwise */3583struct ref_lock *lock;3584int type;3585const char refname[FLEX_ARRAY];3586};35873588/*3589 * Data structure for holding a reference transaction, which can3590 * consist of checks and updates to multiple references, carried out3591 * as atomically as possible. This structure is opaque to callers.3592 */3593struct ref_transaction {3594struct ref_update **updates;3595size_t alloc;3596size_t nr;3597};35983599struct ref_transaction *ref_transaction_begin(void)3600{3601returnxcalloc(1,sizeof(struct ref_transaction));3602}36033604voidref_transaction_free(struct ref_transaction *transaction)3605{3606int i;36073608if(!transaction)3609return;36103611for(i =0; i < transaction->nr; i++)3612free(transaction->updates[i]);36133614free(transaction->updates);3615free(transaction);3616}36173618static struct ref_update *add_update(struct ref_transaction *transaction,3619const char*refname)3620{3621size_t len =strlen(refname);3622struct ref_update *update =xcalloc(1,sizeof(*update) + len +1);36233624strcpy((char*)update->refname, refname);3625ALLOC_GROW(transaction->updates, transaction->nr +1, transaction->alloc);3626 transaction->updates[transaction->nr++] = update;3627return update;3628}36293630intref_transaction_update(struct ref_transaction *transaction,3631const char*refname,3632const unsigned char*new_sha1,3633const unsigned char*old_sha1,3634int flags,int have_old,3635struct strbuf *err)3636{3637struct ref_update *update;36383639if(have_old && !old_sha1)3640die("BUG: have_old is true but old_sha1 is NULL");36413642 update =add_update(transaction, refname);3643hashcpy(update->new_sha1, new_sha1);3644 update->flags = flags;3645 update->have_old = have_old;3646if(have_old)3647hashcpy(update->old_sha1, old_sha1);3648return0;3649}36503651voidref_transaction_create(struct ref_transaction *transaction,3652const char*refname,3653const unsigned char*new_sha1,3654int flags)3655{3656struct ref_update *update =add_update(transaction, refname);36573658assert(!is_null_sha1(new_sha1));3659hashcpy(update->new_sha1, new_sha1);3660hashclr(update->old_sha1);3661 update->flags = flags;3662 update->have_old =1;3663}36643665voidref_transaction_delete(struct ref_transaction *transaction,3666const char*refname,3667const unsigned char*old_sha1,3668int flags,int have_old)3669{3670struct ref_update *update =add_update(transaction, refname);36713672 update->flags = flags;3673 update->have_old = have_old;3674if(have_old) {3675assert(!is_null_sha1(old_sha1));3676hashcpy(update->old_sha1, old_sha1);3677}3678}36793680intupdate_ref(const char*action,const char*refname,3681const unsigned char*sha1,const unsigned char*oldval,3682int flags,enum action_on_err onerr)3683{3684struct ref_lock *lock;3685 lock =update_ref_lock(refname, oldval, flags, NULL, onerr);3686if(!lock)3687return1;3688returnupdate_ref_write(action, refname, sha1, lock, NULL, onerr);3689}36903691static intref_update_compare(const void*r1,const void*r2)3692{3693const struct ref_update *const*u1 = r1;3694const struct ref_update *const*u2 = r2;3695returnstrcmp((*u1)->refname, (*u2)->refname);3696}36973698static intref_update_reject_duplicates(struct ref_update **updates,int n,3699struct strbuf *err)3700{3701int i;3702for(i =1; i < n; i++)3703if(!strcmp(updates[i -1]->refname, updates[i]->refname)) {3704const char*str =3705"Multiple updates for ref '%s' not allowed.";3706if(err)3707strbuf_addf(err, str, updates[i]->refname);37083709return1;3710}3711return0;3712}37133714intref_transaction_commit(struct ref_transaction *transaction,3715const char*msg,struct strbuf *err)3716{3717int ret =0, delnum =0, i;3718const char**delnames;3719int n = transaction->nr;3720struct ref_update **updates = transaction->updates;37213722if(!n)3723return0;37243725/* Allocate work space */3726 delnames =xmalloc(sizeof(*delnames) * n);37273728/* Copy, sort, and reject duplicate refs */3729qsort(updates, n,sizeof(*updates), ref_update_compare);3730 ret =ref_update_reject_duplicates(updates, n, err);3731if(ret)3732goto cleanup;37333734/* Acquire all locks while verifying old values */3735for(i =0; i < n; i++) {3736struct ref_update *update = updates[i];37373738 update->lock =update_ref_lock(update->refname,3739(update->have_old ?3740 update->old_sha1 : NULL),3741 update->flags,3742&update->type,3743 UPDATE_REFS_QUIET_ON_ERR);3744if(!update->lock) {3745if(err)3746strbuf_addf(err,"Cannot lock the ref '%s'.",3747 update->refname);3748 ret =1;3749goto cleanup;3750}3751}37523753/* Perform updates first so live commits remain referenced */3754for(i =0; i < n; i++) {3755struct ref_update *update = updates[i];37563757if(!is_null_sha1(update->new_sha1)) {3758 ret =update_ref_write(msg,3759 update->refname,3760 update->new_sha1,3761 update->lock, err,3762 UPDATE_REFS_QUIET_ON_ERR);3763 update->lock = NULL;/* freed by update_ref_write */3764if(ret)3765goto cleanup;3766}3767}37683769/* Perform deletes now that updates are safely completed */3770for(i =0; i < n; i++) {3771struct ref_update *update = updates[i];37723773if(update->lock) {3774 delnames[delnum++] = update->lock->ref_name;3775 ret |=delete_ref_loose(update->lock, update->type);3776}3777}37783779 ret |=repack_without_refs(delnames, delnum, err);3780for(i =0; i < delnum; i++)3781unlink_or_warn(git_path("logs/%s", delnames[i]));3782clear_loose_ref_cache(&ref_cache);37833784cleanup:3785for(i =0; i < n; i++)3786if(updates[i]->lock)3787unlock_ref(updates[i]->lock);3788free(delnames);3789return ret;3790}37913792char*shorten_unambiguous_ref(const char*refname,int strict)3793{3794int i;3795static char**scanf_fmts;3796static int nr_rules;3797char*short_name;37983799if(!nr_rules) {3800/*3801 * Pre-generate scanf formats from ref_rev_parse_rules[].3802 * Generate a format suitable for scanf from a3803 * ref_rev_parse_rules rule by interpolating "%s" at the3804 * location of the "%.*s".3805 */3806size_t total_len =0;3807size_t offset =0;38083809/* the rule list is NULL terminated, count them first */3810for(nr_rules =0; ref_rev_parse_rules[nr_rules]; nr_rules++)3811/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3812 total_len +=strlen(ref_rev_parse_rules[nr_rules]) -2+1;38133814 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);38153816 offset =0;3817for(i =0; i < nr_rules; i++) {3818assert(offset < total_len);3819 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules] + offset;3820 offset +=snprintf(scanf_fmts[i], total_len - offset,3821 ref_rev_parse_rules[i],2,"%s") +1;3822}3823}38243825/* bail out if there are no rules */3826if(!nr_rules)3827returnxstrdup(refname);38283829/* buffer for scanf result, at most refname must fit */3830 short_name =xstrdup(refname);38313832/* skip first rule, it will always match */3833for(i = nr_rules -1; i >0; --i) {3834int j;3835int rules_to_fail = i;3836int short_name_len;38373838if(1!=sscanf(refname, scanf_fmts[i], short_name))3839continue;38403841 short_name_len =strlen(short_name);38423843/*3844 * in strict mode, all (except the matched one) rules3845 * must fail to resolve to a valid non-ambiguous ref3846 */3847if(strict)3848 rules_to_fail = nr_rules;38493850/*3851 * check if the short name resolves to a valid ref,3852 * but use only rules prior to the matched one3853 */3854for(j =0; j < rules_to_fail; j++) {3855const char*rule = ref_rev_parse_rules[j];3856char refname[PATH_MAX];38573858/* skip matched rule */3859if(i == j)3860continue;38613862/*3863 * the short name is ambiguous, if it resolves3864 * (with this previous rule) to a valid ref3865 * read_ref() returns 0 on success3866 */3867mksnpath(refname,sizeof(refname),3868 rule, short_name_len, short_name);3869if(ref_exists(refname))3870break;3871}38723873/*3874 * short name is non-ambiguous if all previous rules3875 * haven't resolved to a valid ref3876 */3877if(j == rules_to_fail)3878return short_name;3879}38803881free(short_name);3882returnxstrdup(refname);3883}38843885static struct string_list *hide_refs;38863887intparse_hide_refs_config(const char*var,const char*value,const char*section)3888{3889if(!strcmp("transfer.hiderefs", var) ||3890/* NEEDSWORK: use parse_config_key() once both are merged */3891(starts_with(var, section) && var[strlen(section)] =='.'&&3892!strcmp(var +strlen(section),".hiderefs"))) {3893char*ref;3894int len;38953896if(!value)3897returnconfig_error_nonbool(var);3898 ref =xstrdup(value);3899 len =strlen(ref);3900while(len && ref[len -1] =='/')3901 ref[--len] ='\0';3902if(!hide_refs) {3903 hide_refs =xcalloc(1,sizeof(*hide_refs));3904 hide_refs->strdup_strings =1;3905}3906string_list_append(hide_refs, ref);3907}3908return0;3909}39103911intref_is_hidden(const char*refname)3912{3913struct string_list_item *item;39143915if(!hide_refs)3916return0;3917for_each_string_list_item(item, hide_refs) {3918int len;3919if(!starts_with(refname, item->string))3920continue;3921 len =strlen(item->string);3922if(!refname[len] || refname[len] =='/')3923return1;3924}3925return0;3926}