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(has_extension(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}15351536const char*resolve_ref_unsafe(const char*refname,unsigned char*sha1,int reading,int*flag)1537{1538int depth = MAXDEPTH;1539 ssize_t len;1540char buffer[256];1541static char refname_buffer[256];15421543if(flag)1544*flag =0;15451546if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1547return NULL;15481549for(;;) {1550char path[PATH_MAX];1551struct stat st;1552char*buf;1553int fd;15541555if(--depth <0)1556return NULL;15571558git_snpath(path,sizeof(path),"%s", refname);15591560/*1561 * We might have to loop back here to avoid a race1562 * condition: first we lstat() the file, then we try1563 * to read it as a link or as a file. But if somebody1564 * changes the type of the file (file <-> directory1565 * <-> symlink) between the lstat() and reading, then1566 * we don't want to report that as an error but rather1567 * try again starting with the lstat().1568 */1569 stat_ref:1570if(lstat(path, &st) <0) {1571if(errno == ENOENT)1572returnhandle_missing_loose_ref(refname, sha1,1573 reading, flag);1574else1575return NULL;1576}15771578/* Follow "normalized" - ie "refs/.." symlinks by hand */1579if(S_ISLNK(st.st_mode)) {1580 len =readlink(path, buffer,sizeof(buffer)-1);1581if(len <0) {1582if(errno == ENOENT || errno == EINVAL)1583/* inconsistent with lstat; retry */1584goto stat_ref;1585else1586return NULL;1587}1588 buffer[len] =0;1589if(starts_with(buffer,"refs/") &&1590!check_refname_format(buffer,0)) {1591strcpy(refname_buffer, buffer);1592 refname = refname_buffer;1593if(flag)1594*flag |= REF_ISSYMREF;1595continue;1596}1597}15981599/* Is it a directory? */1600if(S_ISDIR(st.st_mode)) {1601 errno = EISDIR;1602return NULL;1603}16041605/*1606 * Anything else, just open it and try to use it as1607 * a ref1608 */1609 fd =open(path, O_RDONLY);1610if(fd <0) {1611if(errno == ENOENT)1612/* inconsistent with lstat; retry */1613goto stat_ref;1614else1615return NULL;1616}1617 len =read_in_full(fd, buffer,sizeof(buffer)-1);1618close(fd);1619if(len <0)1620return NULL;1621while(len &&isspace(buffer[len-1]))1622 len--;1623 buffer[len] ='\0';16241625/*1626 * Is it a symbolic ref?1627 */1628if(!starts_with(buffer,"ref:")) {1629/*1630 * Please note that FETCH_HEAD has a second1631 * line containing other data.1632 */1633if(get_sha1_hex(buffer, sha1) ||1634(buffer[40] !='\0'&& !isspace(buffer[40]))) {1635if(flag)1636*flag |= REF_ISBROKEN;1637return NULL;1638}1639return refname;1640}1641if(flag)1642*flag |= REF_ISSYMREF;1643 buf = buffer +4;1644while(isspace(*buf))1645 buf++;1646if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1647if(flag)1648*flag |= REF_ISBROKEN;1649return NULL;1650}1651 refname =strcpy(refname_buffer, buf);1652}1653}16541655char*resolve_refdup(const char*ref,unsigned char*sha1,int reading,int*flag)1656{1657const char*ret =resolve_ref_unsafe(ref, sha1, reading, flag);1658return ret ?xstrdup(ret) : NULL;1659}16601661/* The argument to filter_refs */1662struct ref_filter {1663const char*pattern;1664 each_ref_fn *fn;1665void*cb_data;1666};16671668intread_ref_full(const char*refname,unsigned char*sha1,int reading,int*flags)1669{1670if(resolve_ref_unsafe(refname, sha1, reading, flags))1671return0;1672return-1;1673}16741675intread_ref(const char*refname,unsigned char*sha1)1676{1677returnread_ref_full(refname, sha1,1, NULL);1678}16791680intref_exists(const char*refname)1681{1682unsigned char sha1[20];1683return!!resolve_ref_unsafe(refname, sha1,1, NULL);1684}16851686static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1687void*data)1688{1689struct ref_filter *filter = (struct ref_filter *)data;1690if(wildmatch(filter->pattern, refname,0, NULL))1691return0;1692return filter->fn(refname, sha1, flags, filter->cb_data);1693}16941695enum peel_status {1696/* object was peeled successfully: */1697 PEEL_PEELED =0,16981699/*1700 * object cannot be peeled because the named object (or an1701 * object referred to by a tag in the peel chain), does not1702 * exist.1703 */1704 PEEL_INVALID = -1,17051706/* object cannot be peeled because it is not a tag: */1707 PEEL_NON_TAG = -2,17081709/* ref_entry contains no peeled value because it is a symref: */1710 PEEL_IS_SYMREF = -3,17111712/*1713 * ref_entry cannot be peeled because it is broken (i.e., the1714 * symbolic reference cannot even be resolved to an object1715 * name):1716 */1717 PEEL_BROKEN = -41718};17191720/*1721 * Peel the named object; i.e., if the object is a tag, resolve the1722 * tag recursively until a non-tag is found. If successful, store the1723 * result to sha1 and return PEEL_PEELED. If the object is not a tag1724 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1725 * and leave sha1 unchanged.1726 */1727static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1728{1729struct object *o =lookup_unknown_object(name);17301731if(o->type == OBJ_NONE) {1732int type =sha1_object_info(name, NULL);1733if(type <0)1734return PEEL_INVALID;1735 o->type = type;1736}17371738if(o->type != OBJ_TAG)1739return PEEL_NON_TAG;17401741 o =deref_tag_noverify(o);1742if(!o)1743return PEEL_INVALID;17441745hashcpy(sha1, o->sha1);1746return PEEL_PEELED;1747}17481749/*1750 * Peel the entry (if possible) and return its new peel_status. If1751 * repeel is true, re-peel the entry even if there is an old peeled1752 * value that is already stored in it.1753 *1754 * It is OK to call this function with a packed reference entry that1755 * might be stale and might even refer to an object that has since1756 * been garbage-collected. In such a case, if the entry has1757 * REF_KNOWS_PEELED then leave the status unchanged and return1758 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1759 */1760static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1761{1762enum peel_status status;17631764if(entry->flag & REF_KNOWS_PEELED) {1765if(repeel) {1766 entry->flag &= ~REF_KNOWS_PEELED;1767hashclr(entry->u.value.peeled);1768}else{1769returnis_null_sha1(entry->u.value.peeled) ?1770 PEEL_NON_TAG : PEEL_PEELED;1771}1772}1773if(entry->flag & REF_ISBROKEN)1774return PEEL_BROKEN;1775if(entry->flag & REF_ISSYMREF)1776return PEEL_IS_SYMREF;17771778 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1779if(status == PEEL_PEELED || status == PEEL_NON_TAG)1780 entry->flag |= REF_KNOWS_PEELED;1781return status;1782}17831784intpeel_ref(const char*refname,unsigned char*sha1)1785{1786int flag;1787unsigned char base[20];17881789if(current_ref && (current_ref->name == refname1790|| !strcmp(current_ref->name, refname))) {1791if(peel_entry(current_ref,0))1792return-1;1793hashcpy(sha1, current_ref->u.value.peeled);1794return0;1795}17961797if(read_ref_full(refname, base,1, &flag))1798return-1;17991800/*1801 * If the reference is packed, read its ref_entry from the1802 * cache in the hope that we already know its peeled value.1803 * We only try this optimization on packed references because1804 * (a) forcing the filling of the loose reference cache could1805 * be expensive and (b) loose references anyway usually do not1806 * have REF_KNOWS_PEELED.1807 */1808if(flag & REF_ISPACKED) {1809struct ref_entry *r =get_packed_ref(refname);1810if(r) {1811if(peel_entry(r,0))1812return-1;1813hashcpy(sha1, r->u.value.peeled);1814return0;1815}1816}18171818returnpeel_object(base, sha1);1819}18201821struct warn_if_dangling_data {1822FILE*fp;1823const char*refname;1824const char*msg_fmt;1825};18261827static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1828int flags,void*cb_data)1829{1830struct warn_if_dangling_data *d = cb_data;1831const char*resolves_to;1832unsigned char junk[20];18331834if(!(flags & REF_ISSYMREF))1835return0;18361837 resolves_to =resolve_ref_unsafe(refname, junk,0, NULL);1838if(!resolves_to ||strcmp(resolves_to, d->refname))1839return0;18401841fprintf(d->fp, d->msg_fmt, refname);1842fputc('\n', d->fp);1843return0;1844}18451846voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1847{1848struct warn_if_dangling_data data;18491850 data.fp = fp;1851 data.refname = refname;1852 data.msg_fmt = msg_fmt;1853for_each_rawref(warn_if_dangling_symref, &data);1854}18551856/*1857 * Call fn for each reference in the specified ref_cache, omitting1858 * references not in the containing_dir of base. fn is called for all1859 * references, including broken ones. If fn ever returns a non-zero1860 * value, stop the iteration and return that value; otherwise, return1861 * 0.1862 */1863static intdo_for_each_entry(struct ref_cache *refs,const char*base,1864 each_ref_entry_fn fn,void*cb_data)1865{1866struct packed_ref_cache *packed_ref_cache;1867struct ref_dir *loose_dir;1868struct ref_dir *packed_dir;1869int retval =0;18701871/*1872 * We must make sure that all loose refs are read before accessing the1873 * packed-refs file; this avoids a race condition in which loose refs1874 * are migrated to the packed-refs file by a simultaneous process, but1875 * our in-memory view is from before the migration. get_packed_ref_cache()1876 * takes care of making sure our view is up to date with what is on1877 * disk.1878 */1879 loose_dir =get_loose_refs(refs);1880if(base && *base) {1881 loose_dir =find_containing_dir(loose_dir, base,0);1882}1883if(loose_dir)1884prime_ref_dir(loose_dir);18851886 packed_ref_cache =get_packed_ref_cache(refs);1887acquire_packed_ref_cache(packed_ref_cache);1888 packed_dir =get_packed_ref_dir(packed_ref_cache);1889if(base && *base) {1890 packed_dir =find_containing_dir(packed_dir, base,0);1891}18921893if(packed_dir && loose_dir) {1894sort_ref_dir(packed_dir);1895sort_ref_dir(loose_dir);1896 retval =do_for_each_entry_in_dirs(1897 packed_dir, loose_dir, fn, cb_data);1898}else if(packed_dir) {1899sort_ref_dir(packed_dir);1900 retval =do_for_each_entry_in_dir(1901 packed_dir,0, fn, cb_data);1902}else if(loose_dir) {1903sort_ref_dir(loose_dir);1904 retval =do_for_each_entry_in_dir(1905 loose_dir,0, fn, cb_data);1906}19071908release_packed_ref_cache(packed_ref_cache);1909return retval;1910}19111912/*1913 * Call fn for each reference in the specified ref_cache for which the1914 * refname begins with base. If trim is non-zero, then trim that many1915 * characters off the beginning of each refname before passing the1916 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1917 * broken references in the iteration. If fn ever returns a non-zero1918 * value, stop the iteration and return that value; otherwise, return1919 * 0.1920 */1921static intdo_for_each_ref(struct ref_cache *refs,const char*base,1922 each_ref_fn fn,int trim,int flags,void*cb_data)1923{1924struct ref_entry_cb data;1925 data.base = base;1926 data.trim = trim;1927 data.flags = flags;1928 data.fn = fn;1929 data.cb_data = cb_data;19301931returndo_for_each_entry(refs, base, do_one_ref, &data);1932}19331934static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1935{1936unsigned char sha1[20];1937int flag;19381939if(submodule) {1940if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1941returnfn("HEAD", sha1,0, cb_data);19421943return0;1944}19451946if(!read_ref_full("HEAD", sha1,1, &flag))1947returnfn("HEAD", sha1, flag, cb_data);19481949return0;1950}19511952inthead_ref(each_ref_fn fn,void*cb_data)1953{1954returndo_head_ref(NULL, fn, cb_data);1955}19561957inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1958{1959returndo_head_ref(submodule, fn, cb_data);1960}19611962intfor_each_ref(each_ref_fn fn,void*cb_data)1963{1964returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1965}19661967intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1968{1969returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1970}19711972intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1973{1974returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);1975}19761977intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1978 each_ref_fn fn,void*cb_data)1979{1980returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);1981}19821983intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1984{1985returnfor_each_ref_in("refs/tags/", fn, cb_data);1986}19871988intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1989{1990returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1991}19921993intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1994{1995returnfor_each_ref_in("refs/heads/", fn, cb_data);1996}19971998intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1999{2000returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);2001}20022003intfor_each_remote_ref(each_ref_fn fn,void*cb_data)2004{2005returnfor_each_ref_in("refs/remotes/", fn, cb_data);2006}20072008intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2009{2010returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);2011}20122013intfor_each_replace_ref(each_ref_fn fn,void*cb_data)2014{2015returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);2016}20172018inthead_ref_namespaced(each_ref_fn fn,void*cb_data)2019{2020struct strbuf buf = STRBUF_INIT;2021int ret =0;2022unsigned char sha1[20];2023int flag;20242025strbuf_addf(&buf,"%sHEAD",get_git_namespace());2026if(!read_ref_full(buf.buf, sha1,1, &flag))2027 ret =fn(buf.buf, sha1, flag, cb_data);2028strbuf_release(&buf);20292030return ret;2031}20322033intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)2034{2035struct strbuf buf = STRBUF_INIT;2036int ret;2037strbuf_addf(&buf,"%srefs/",get_git_namespace());2038 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);2039strbuf_release(&buf);2040return ret;2041}20422043intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,2044const char*prefix,void*cb_data)2045{2046struct strbuf real_pattern = STRBUF_INIT;2047struct ref_filter filter;2048int ret;20492050if(!prefix && !starts_with(pattern,"refs/"))2051strbuf_addstr(&real_pattern,"refs/");2052else if(prefix)2053strbuf_addstr(&real_pattern, prefix);2054strbuf_addstr(&real_pattern, pattern);20552056if(!has_glob_specials(pattern)) {2057/* Append implied '/' '*' if not present. */2058if(real_pattern.buf[real_pattern.len -1] !='/')2059strbuf_addch(&real_pattern,'/');2060/* No need to check for '*', there is none. */2061strbuf_addch(&real_pattern,'*');2062}20632064 filter.pattern = real_pattern.buf;2065 filter.fn = fn;2066 filter.cb_data = cb_data;2067 ret =for_each_ref(filter_refs, &filter);20682069strbuf_release(&real_pattern);2070return ret;2071}20722073intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)2074{2075returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);2076}20772078intfor_each_rawref(each_ref_fn fn,void*cb_data)2079{2080returndo_for_each_ref(&ref_cache,"", fn,0,2081 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2082}20832084const char*prettify_refname(const char*name)2085{2086return name + (2087starts_with(name,"refs/heads/") ?11:2088starts_with(name,"refs/tags/") ?10:2089starts_with(name,"refs/remotes/") ?13:20900);2091}20922093static const char*ref_rev_parse_rules[] = {2094"%.*s",2095"refs/%.*s",2096"refs/tags/%.*s",2097"refs/heads/%.*s",2098"refs/remotes/%.*s",2099"refs/remotes/%.*s/HEAD",2100 NULL2101};21022103intrefname_match(const char*abbrev_name,const char*full_name)2104{2105const char**p;2106const int abbrev_name_len =strlen(abbrev_name);21072108for(p = ref_rev_parse_rules; *p; p++) {2109if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {2110return1;2111}2112}21132114return0;2115}21162117static struct ref_lock *verify_lock(struct ref_lock *lock,2118const unsigned char*old_sha1,int mustexist)2119{2120if(read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {2121error("Can't verify ref%s", lock->ref_name);2122unlock_ref(lock);2123return NULL;2124}2125if(hashcmp(lock->old_sha1, old_sha1)) {2126error("Ref%sis at%sbut expected%s", lock->ref_name,2127sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));2128unlock_ref(lock);2129return NULL;2130}2131return lock;2132}21332134static intremove_empty_directories(const char*file)2135{2136/* we want to create a file but there is a directory there;2137 * if that is an empty directory (or a directory that contains2138 * only empty directories), remove them.2139 */2140struct strbuf path;2141int result;21422143strbuf_init(&path,20);2144strbuf_addstr(&path, file);21452146 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);21472148strbuf_release(&path);21492150return result;2151}21522153/*2154 * *string and *len will only be substituted, and *string returned (for2155 * later free()ing) if the string passed in is a magic short-hand form2156 * to name a branch.2157 */2158static char*substitute_branch_name(const char**string,int*len)2159{2160struct strbuf buf = STRBUF_INIT;2161int ret =interpret_branch_name(*string, *len, &buf);21622163if(ret == *len) {2164size_t size;2165*string =strbuf_detach(&buf, &size);2166*len = size;2167return(char*)*string;2168}21692170return NULL;2171}21722173intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)2174{2175char*last_branch =substitute_branch_name(&str, &len);2176const char**p, *r;2177int refs_found =0;21782179*ref = NULL;2180for(p = ref_rev_parse_rules; *p; p++) {2181char fullref[PATH_MAX];2182unsigned char sha1_from_ref[20];2183unsigned char*this_result;2184int flag;21852186 this_result = refs_found ? sha1_from_ref : sha1;2187mksnpath(fullref,sizeof(fullref), *p, len, str);2188 r =resolve_ref_unsafe(fullref, this_result,1, &flag);2189if(r) {2190if(!refs_found++)2191*ref =xstrdup(r);2192if(!warn_ambiguous_refs)2193break;2194}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {2195warning("ignoring dangling symref%s.", fullref);2196}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {2197warning("ignoring broken ref%s.", fullref);2198}2199}2200free(last_branch);2201return refs_found;2202}22032204intdwim_log(const char*str,int len,unsigned char*sha1,char**log)2205{2206char*last_branch =substitute_branch_name(&str, &len);2207const char**p;2208int logs_found =0;22092210*log = NULL;2211for(p = ref_rev_parse_rules; *p; p++) {2212struct stat st;2213unsigned char hash[20];2214char path[PATH_MAX];2215const char*ref, *it;22162217mksnpath(path,sizeof(path), *p, len, str);2218 ref =resolve_ref_unsafe(path, hash,1, NULL);2219if(!ref)2220continue;2221if(!stat(git_path("logs/%s", path), &st) &&2222S_ISREG(st.st_mode))2223 it = path;2224else if(strcmp(ref, path) &&2225!stat(git_path("logs/%s", ref), &st) &&2226S_ISREG(st.st_mode))2227 it = ref;2228else2229continue;2230if(!logs_found++) {2231*log =xstrdup(it);2232hashcpy(sha1, hash);2233}2234if(!warn_ambiguous_refs)2235break;2236}2237free(last_branch);2238return logs_found;2239}22402241static struct ref_lock *lock_ref_sha1_basic(const char*refname,2242const unsigned char*old_sha1,2243int flags,int*type_p)2244{2245char*ref_file;2246const char*orig_refname = refname;2247struct ref_lock *lock;2248int last_errno =0;2249int type, lflags;2250int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2251int missing =0;2252int attempts_remaining =3;22532254 lock =xcalloc(1,sizeof(struct ref_lock));2255 lock->lock_fd = -1;22562257 refname =resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);2258if(!refname && errno == EISDIR) {2259/* we are trying to lock foo but we used to2260 * have foo/bar which now does not exist;2261 * it is normal for the empty directory 'foo'2262 * to remain.2263 */2264 ref_file =git_path("%s", orig_refname);2265if(remove_empty_directories(ref_file)) {2266 last_errno = errno;2267error("there are still refs under '%s'", orig_refname);2268goto error_return;2269}2270 refname =resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);2271}2272if(type_p)2273*type_p = type;2274if(!refname) {2275 last_errno = errno;2276error("unable to resolve reference%s:%s",2277 orig_refname,strerror(errno));2278goto error_return;2279}2280 missing =is_null_sha1(lock->old_sha1);2281/* When the ref did not exist and we are creating it,2282 * make sure there is no existing ref that is packed2283 * whose name begins with our refname, nor a ref whose2284 * name is a proper prefix of our refname.2285 */2286if(missing &&2287!is_refname_available(refname, NULL,get_packed_refs(&ref_cache))) {2288 last_errno = ENOTDIR;2289goto error_return;2290}22912292 lock->lk =xcalloc(1,sizeof(struct lock_file));22932294 lflags =0;2295if(flags & REF_NODEREF) {2296 refname = orig_refname;2297 lflags |= LOCK_NODEREF;2298}2299 lock->ref_name =xstrdup(refname);2300 lock->orig_ref_name =xstrdup(orig_refname);2301 ref_file =git_path("%s", refname);2302if(missing)2303 lock->force_write =1;2304if((flags & REF_NODEREF) && (type & REF_ISSYMREF))2305 lock->force_write =1;23062307 retry:2308switch(safe_create_leading_directories(ref_file)) {2309case SCLD_OK:2310break;/* success */2311case SCLD_VANISHED:2312if(--attempts_remaining >0)2313goto retry;2314/* fall through */2315default:2316 last_errno = errno;2317error("unable to create directory for%s", ref_file);2318goto error_return;2319}23202321 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);2322if(lock->lock_fd <0) {2323if(errno == ENOENT && --attempts_remaining >0)2324/*2325 * Maybe somebody just deleted one of the2326 * directories leading to ref_file. Try2327 * again:2328 */2329goto retry;2330else2331unable_to_lock_index_die(ref_file, errno);2332}2333return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;23342335 error_return:2336unlock_ref(lock);2337 errno = last_errno;2338return NULL;2339}23402341struct ref_lock *lock_ref_sha1(const char*refname,const unsigned char*old_sha1)2342{2343char refpath[PATH_MAX];2344if(check_refname_format(refname,0))2345return NULL;2346strcpy(refpath,mkpath("refs/%s", refname));2347returnlock_ref_sha1_basic(refpath, old_sha1,0, NULL);2348}23492350struct ref_lock *lock_any_ref_for_update(const char*refname,2351const unsigned char*old_sha1,2352int flags,int*type_p)2353{2354if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))2355return NULL;2356returnlock_ref_sha1_basic(refname, old_sha1, flags, type_p);2357}23582359/*2360 * Write an entry to the packed-refs file for the specified refname.2361 * If peeled is non-NULL, write it as the entry's peeled value.2362 */2363static voidwrite_packed_entry(int fd,char*refname,unsigned char*sha1,2364unsigned char*peeled)2365{2366char line[PATH_MAX +100];2367int len;23682369 len =snprintf(line,sizeof(line),"%s %s\n",2370sha1_to_hex(sha1), refname);2371/* this should not happen but just being defensive */2372if(len >sizeof(line))2373die("too long a refname '%s'", refname);2374write_or_die(fd, line, len);23752376if(peeled) {2377if(snprintf(line,sizeof(line),"^%s\n",2378sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)2379die("internal error");2380write_or_die(fd, line, PEELED_LINE_LENGTH);2381}2382}23832384/*2385 * An each_ref_entry_fn that writes the entry to a packed-refs file.2386 */2387static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2388{2389int*fd = cb_data;2390enum peel_status peel_status =peel_entry(entry,0);23912392if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2393error("internal error:%sis not a valid packed reference!",2394 entry->name);2395write_packed_entry(*fd, entry->name, entry->u.value.sha1,2396 peel_status == PEEL_PEELED ?2397 entry->u.value.peeled : NULL);2398return0;2399}24002401intlock_packed_refs(int flags)2402{2403struct packed_ref_cache *packed_ref_cache;24042405if(hold_lock_file_for_update(&packlock,git_path("packed-refs"), flags) <0)2406return-1;2407/*2408 * Get the current packed-refs while holding the lock. If the2409 * packed-refs file has been modified since we last read it,2410 * this will automatically invalidate the cache and re-read2411 * the packed-refs file.2412 */2413 packed_ref_cache =get_packed_ref_cache(&ref_cache);2414 packed_ref_cache->lock = &packlock;2415/* Increment the reference count to prevent it from being freed: */2416acquire_packed_ref_cache(packed_ref_cache);2417return0;2418}24192420intcommit_packed_refs(void)2421{2422struct packed_ref_cache *packed_ref_cache =2423get_packed_ref_cache(&ref_cache);2424int error =0;24252426if(!packed_ref_cache->lock)2427die("internal error: packed-refs not locked");2428write_or_die(packed_ref_cache->lock->fd,2429 PACKED_REFS_HEADER,strlen(PACKED_REFS_HEADER));24302431do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),24320, write_packed_entry_fn,2433&packed_ref_cache->lock->fd);2434if(commit_lock_file(packed_ref_cache->lock))2435 error = -1;2436 packed_ref_cache->lock = NULL;2437release_packed_ref_cache(packed_ref_cache);2438return error;2439}24402441voidrollback_packed_refs(void)2442{2443struct packed_ref_cache *packed_ref_cache =2444get_packed_ref_cache(&ref_cache);24452446if(!packed_ref_cache->lock)2447die("internal error: packed-refs not locked");2448rollback_lock_file(packed_ref_cache->lock);2449 packed_ref_cache->lock = NULL;2450release_packed_ref_cache(packed_ref_cache);2451clear_packed_ref_cache(&ref_cache);2452}24532454struct ref_to_prune {2455struct ref_to_prune *next;2456unsigned char sha1[20];2457char name[FLEX_ARRAY];2458};24592460struct pack_refs_cb_data {2461unsigned int flags;2462struct ref_dir *packed_refs;2463struct ref_to_prune *ref_to_prune;2464};24652466/*2467 * An each_ref_entry_fn that is run over loose references only. If2468 * the loose reference can be packed, add an entry in the packed ref2469 * cache. If the reference should be pruned, also add it to2470 * ref_to_prune in the pack_refs_cb_data.2471 */2472static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2473{2474struct pack_refs_cb_data *cb = cb_data;2475enum peel_status peel_status;2476struct ref_entry *packed_entry;2477int is_tag_ref =starts_with(entry->name,"refs/tags/");24782479/* ALWAYS pack tags */2480if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2481return0;24822483/* Do not pack symbolic or broken refs: */2484if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2485return0;24862487/* Add a packed ref cache entry equivalent to the loose entry. */2488 peel_status =peel_entry(entry,1);2489if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2490die("internal error peeling reference%s(%s)",2491 entry->name,sha1_to_hex(entry->u.value.sha1));2492 packed_entry =find_ref(cb->packed_refs, entry->name);2493if(packed_entry) {2494/* Overwrite existing packed entry with info from loose entry */2495 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2496hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2497}else{2498 packed_entry =create_ref_entry(entry->name, entry->u.value.sha1,2499 REF_ISPACKED | REF_KNOWS_PEELED,0);2500add_ref(cb->packed_refs, packed_entry);2501}2502hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);25032504/* Schedule the loose reference for pruning if requested. */2505if((cb->flags & PACK_REFS_PRUNE)) {2506int namelen =strlen(entry->name) +1;2507struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2508hashcpy(n->sha1, entry->u.value.sha1);2509strcpy(n->name, entry->name);2510 n->next = cb->ref_to_prune;2511 cb->ref_to_prune = n;2512}2513return0;2514}25152516/*2517 * Remove empty parents, but spare refs/ and immediate subdirs.2518 * Note: munges *name.2519 */2520static voidtry_remove_empty_parents(char*name)2521{2522char*p, *q;2523int i;2524 p = name;2525for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2526while(*p && *p !='/')2527 p++;2528/* tolerate duplicate slashes; see check_refname_format() */2529while(*p =='/')2530 p++;2531}2532for(q = p; *q; q++)2533;2534while(1) {2535while(q > p && *q !='/')2536 q--;2537while(q > p && *(q-1) =='/')2538 q--;2539if(q == p)2540break;2541*q ='\0';2542if(rmdir(git_path("%s", name)))2543break;2544}2545}25462547/* make sure nobody touched the ref, and unlink */2548static voidprune_ref(struct ref_to_prune *r)2549{2550struct ref_lock *lock =lock_ref_sha1(r->name +5, r->sha1);25512552if(lock) {2553unlink_or_warn(git_path("%s", r->name));2554unlock_ref(lock);2555try_remove_empty_parents(r->name);2556}2557}25582559static voidprune_refs(struct ref_to_prune *r)2560{2561while(r) {2562prune_ref(r);2563 r = r->next;2564}2565}25662567intpack_refs(unsigned int flags)2568{2569struct pack_refs_cb_data cbdata;25702571memset(&cbdata,0,sizeof(cbdata));2572 cbdata.flags = flags;25732574lock_packed_refs(LOCK_DIE_ON_ERROR);2575 cbdata.packed_refs =get_packed_refs(&ref_cache);25762577do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2578 pack_if_possible_fn, &cbdata);25792580if(commit_packed_refs())2581die_errno("unable to overwrite old ref-pack file");25822583prune_refs(cbdata.ref_to_prune);2584return0;2585}25862587/*2588 * If entry is no longer needed in packed-refs, add it to the string2589 * list pointed to by cb_data. Reasons for deleting entries:2590 *2591 * - Entry is broken.2592 * - Entry is overridden by a loose ref.2593 * - Entry does not point at a valid object.2594 *2595 * In the first and third cases, also emit an error message because these2596 * are indications of repository corruption.2597 */2598static intcurate_packed_ref_fn(struct ref_entry *entry,void*cb_data)2599{2600struct string_list *refs_to_delete = cb_data;26012602if(entry->flag & REF_ISBROKEN) {2603/* This shouldn't happen to packed refs. */2604error("%sis broken!", entry->name);2605string_list_append(refs_to_delete, entry->name);2606return0;2607}2608if(!has_sha1_file(entry->u.value.sha1)) {2609unsigned char sha1[20];2610int flags;26112612if(read_ref_full(entry->name, sha1,0, &flags))2613/* We should at least have found the packed ref. */2614die("Internal error");2615if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2616/*2617 * This packed reference is overridden by a2618 * loose reference, so it is OK that its value2619 * is no longer valid; for example, it might2620 * refer to an object that has been garbage2621 * collected. For this purpose we don't even2622 * care whether the loose reference itself is2623 * invalid, broken, symbolic, etc. Silently2624 * remove the packed reference.2625 */2626string_list_append(refs_to_delete, entry->name);2627return0;2628}2629/*2630 * There is no overriding loose reference, so the fact2631 * that this reference doesn't refer to a valid object2632 * indicates some kind of repository corruption.2633 * Report the problem, then omit the reference from2634 * the output.2635 */2636error("%sdoes not point to a valid object!", entry->name);2637string_list_append(refs_to_delete, entry->name);2638return0;2639}26402641return0;2642}26432644static intrepack_without_refs(const char**refnames,int n)2645{2646struct ref_dir *packed;2647struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2648struct string_list_item *ref_to_delete;2649int i, removed =0;26502651/* Look for a packed ref */2652for(i =0; i < n; i++)2653if(get_packed_ref(refnames[i]))2654break;26552656/* Avoid locking if we have nothing to do */2657if(i == n)2658return0;/* no refname exists in packed refs */26592660if(lock_packed_refs(0)) {2661unable_to_lock_error(git_path("packed-refs"), errno);2662returnerror("cannot delete '%s' from packed refs", refnames[i]);2663}2664 packed =get_packed_refs(&ref_cache);26652666/* Remove refnames from the cache */2667for(i =0; i < n; i++)2668if(remove_entry(packed, refnames[i]) != -1)2669 removed =1;2670if(!removed) {2671/*2672 * All packed entries disappeared while we were2673 * acquiring the lock.2674 */2675rollback_packed_refs();2676return0;2677}26782679/* Remove any other accumulated cruft */2680do_for_each_entry_in_dir(packed,0, curate_packed_ref_fn, &refs_to_delete);2681for_each_string_list_item(ref_to_delete, &refs_to_delete) {2682if(remove_entry(packed, ref_to_delete->string) == -1)2683die("internal error");2684}26852686/* Write what remains */2687returncommit_packed_refs();2688}26892690static intrepack_without_ref(const char*refname)2691{2692returnrepack_without_refs(&refname,1);2693}26942695static intdelete_ref_loose(struct ref_lock *lock,int flag)2696{2697if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2698/* loose */2699int err, i =strlen(lock->lk->filename) -5;/* .lock */27002701 lock->lk->filename[i] =0;2702 err =unlink_or_warn(lock->lk->filename);2703 lock->lk->filename[i] ='.';2704if(err && errno != ENOENT)2705return1;2706}2707return0;2708}27092710intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2711{2712struct ref_lock *lock;2713int ret =0, flag =0;27142715 lock =lock_ref_sha1_basic(refname, sha1, delopt, &flag);2716if(!lock)2717return1;2718 ret |=delete_ref_loose(lock, flag);27192720/* removing the loose one could have resurrected an earlier2721 * packed one. Also, if it was not loose we need to repack2722 * without it.2723 */2724 ret |=repack_without_ref(lock->ref_name);27252726unlink_or_warn(git_path("logs/%s", lock->ref_name));2727clear_loose_ref_cache(&ref_cache);2728unlock_ref(lock);2729return ret;2730}27312732/*2733 * People using contrib's git-new-workdir have .git/logs/refs ->2734 * /some/other/path/.git/logs/refs, and that may live on another device.2735 *2736 * IOW, to avoid cross device rename errors, the temporary renamed log must2737 * live into logs/refs.2738 */2739#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"27402741static intrename_tmp_log(const char*newrefname)2742{2743int attempts_remaining =4;27442745 retry:2746switch(safe_create_leading_directories(git_path("logs/%s", newrefname))) {2747case SCLD_OK:2748break;/* success */2749case SCLD_VANISHED:2750if(--attempts_remaining >0)2751goto retry;2752/* fall through */2753default:2754error("unable to create directory for%s", newrefname);2755return-1;2756}27572758if(rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2759if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2760/*2761 * rename(a, b) when b is an existing2762 * directory ought to result in ISDIR, but2763 * Solaris 5.8 gives ENOTDIR. Sheesh.2764 */2765if(remove_empty_directories(git_path("logs/%s", newrefname))) {2766error("Directory not empty: logs/%s", newrefname);2767return-1;2768}2769goto retry;2770}else if(errno == ENOENT && --attempts_remaining >0) {2771/*2772 * Maybe another process just deleted one of2773 * the directories in the path to newrefname.2774 * Try again from the beginning.2775 */2776goto retry;2777}else{2778error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2779 newrefname,strerror(errno));2780return-1;2781}2782}2783return0;2784}27852786intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2787{2788unsigned char sha1[20], orig_sha1[20];2789int flag =0, logmoved =0;2790struct ref_lock *lock;2791struct stat loginfo;2792int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2793const char*symref = NULL;27942795if(log &&S_ISLNK(loginfo.st_mode))2796returnerror("reflog for%sis a symlink", oldrefname);27972798 symref =resolve_ref_unsafe(oldrefname, orig_sha1,1, &flag);2799if(flag & REF_ISSYMREF)2800returnerror("refname%sis a symbolic ref, renaming it is not supported",2801 oldrefname);2802if(!symref)2803returnerror("refname%snot found", oldrefname);28042805if(!is_refname_available(newrefname, oldrefname,get_packed_refs(&ref_cache)))2806return1;28072808if(!is_refname_available(newrefname, oldrefname,get_loose_refs(&ref_cache)))2809return1;28102811if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2812returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2813 oldrefname,strerror(errno));28142815if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2816error("unable to delete old%s", oldrefname);2817goto rollback;2818}28192820if(!read_ref_full(newrefname, sha1,1, &flag) &&2821delete_ref(newrefname, sha1, REF_NODEREF)) {2822if(errno==EISDIR) {2823if(remove_empty_directories(git_path("%s", newrefname))) {2824error("Directory not empty:%s", newrefname);2825goto rollback;2826}2827}else{2828error("unable to delete existing%s", newrefname);2829goto rollback;2830}2831}28322833if(log &&rename_tmp_log(newrefname))2834goto rollback;28352836 logmoved = log;28372838 lock =lock_ref_sha1_basic(newrefname, NULL,0, NULL);2839if(!lock) {2840error("unable to lock%sfor update", newrefname);2841goto rollback;2842}2843 lock->force_write =1;2844hashcpy(lock->old_sha1, orig_sha1);2845if(write_ref_sha1(lock, orig_sha1, logmsg)) {2846error("unable to write current sha1 into%s", newrefname);2847goto rollback;2848}28492850return0;28512852 rollback:2853 lock =lock_ref_sha1_basic(oldrefname, NULL,0, NULL);2854if(!lock) {2855error("unable to lock%sfor rollback", oldrefname);2856goto rollbacklog;2857}28582859 lock->force_write =1;2860 flag = log_all_ref_updates;2861 log_all_ref_updates =0;2862if(write_ref_sha1(lock, orig_sha1, NULL))2863error("unable to write current sha1 into%s", oldrefname);2864 log_all_ref_updates = flag;28652866 rollbacklog:2867if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2868error("unable to restore logfile%sfrom%s:%s",2869 oldrefname, newrefname,strerror(errno));2870if(!logmoved && log &&2871rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2872error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2873 oldrefname,strerror(errno));28742875return1;2876}28772878intclose_ref(struct ref_lock *lock)2879{2880if(close_lock_file(lock->lk))2881return-1;2882 lock->lock_fd = -1;2883return0;2884}28852886intcommit_ref(struct ref_lock *lock)2887{2888if(commit_lock_file(lock->lk))2889return-1;2890 lock->lock_fd = -1;2891return0;2892}28932894voidunlock_ref(struct ref_lock *lock)2895{2896/* Do not free lock->lk -- atexit() still looks at them */2897if(lock->lk)2898rollback_lock_file(lock->lk);2899free(lock->ref_name);2900free(lock->orig_ref_name);2901free(lock);2902}29032904/*2905 * copy the reflog message msg to buf, which has been allocated sufficiently2906 * large, while cleaning up the whitespaces. Especially, convert LF to space,2907 * because reflog file is one line per entry.2908 */2909static intcopy_msg(char*buf,const char*msg)2910{2911char*cp = buf;2912char c;2913int wasspace =1;29142915*cp++ ='\t';2916while((c = *msg++)) {2917if(wasspace &&isspace(c))2918continue;2919 wasspace =isspace(c);2920if(wasspace)2921 c =' ';2922*cp++ = c;2923}2924while(buf < cp &&isspace(cp[-1]))2925 cp--;2926*cp++ ='\n';2927return cp - buf;2928}29292930intlog_ref_setup(const char*refname,char*logfile,int bufsize)2931{2932int logfd, oflags = O_APPEND | O_WRONLY;29332934git_snpath(logfile, bufsize,"logs/%s", refname);2935if(log_all_ref_updates &&2936(starts_with(refname,"refs/heads/") ||2937starts_with(refname,"refs/remotes/") ||2938starts_with(refname,"refs/notes/") ||2939!strcmp(refname,"HEAD"))) {2940if(safe_create_leading_directories(logfile) <0)2941returnerror("unable to create directory for%s",2942 logfile);2943 oflags |= O_CREAT;2944}29452946 logfd =open(logfile, oflags,0666);2947if(logfd <0) {2948if(!(oflags & O_CREAT) && errno == ENOENT)2949return0;29502951if((oflags & O_CREAT) && errno == EISDIR) {2952if(remove_empty_directories(logfile)) {2953returnerror("There are still logs under '%s'",2954 logfile);2955}2956 logfd =open(logfile, oflags,0666);2957}29582959if(logfd <0)2960returnerror("Unable to append to%s:%s",2961 logfile,strerror(errno));2962}29632964adjust_shared_perm(logfile);2965close(logfd);2966return0;2967}29682969static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2970const unsigned char*new_sha1,const char*msg)2971{2972int logfd, result, written, oflags = O_APPEND | O_WRONLY;2973unsigned maxlen, len;2974int msglen;2975char log_file[PATH_MAX];2976char*logrec;2977const char*committer;29782979if(log_all_ref_updates <0)2980 log_all_ref_updates = !is_bare_repository();29812982 result =log_ref_setup(refname, log_file,sizeof(log_file));2983if(result)2984return result;29852986 logfd =open(log_file, oflags);2987if(logfd <0)2988return0;2989 msglen = msg ?strlen(msg) :0;2990 committer =git_committer_info(0);2991 maxlen =strlen(committer) + msglen +100;2992 logrec =xmalloc(maxlen);2993 len =sprintf(logrec,"%s %s %s\n",2994sha1_to_hex(old_sha1),2995sha1_to_hex(new_sha1),2996 committer);2997if(msglen)2998 len +=copy_msg(logrec + len -1, msg) -1;2999 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;3000free(logrec);3001if(close(logfd) !=0|| written != len)3002returnerror("Unable to append to%s", log_file);3003return0;3004}30053006static intis_branch(const char*refname)3007{3008return!strcmp(refname,"HEAD") ||starts_with(refname,"refs/heads/");3009}30103011intwrite_ref_sha1(struct ref_lock *lock,3012const unsigned char*sha1,const char*logmsg)3013{3014static char term ='\n';3015struct object *o;30163017if(!lock)3018return-1;3019if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {3020unlock_ref(lock);3021return0;3022}3023 o =parse_object(sha1);3024if(!o) {3025error("Trying to write ref%swith nonexistent object%s",3026 lock->ref_name,sha1_to_hex(sha1));3027unlock_ref(lock);3028return-1;3029}3030if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {3031error("Trying to write non-commit object%sto branch%s",3032sha1_to_hex(sha1), lock->ref_name);3033unlock_ref(lock);3034return-1;3035}3036if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||3037write_in_full(lock->lock_fd, &term,1) !=13038||close_ref(lock) <0) {3039error("Couldn't write%s", lock->lk->filename);3040unlock_ref(lock);3041return-1;3042}3043clear_loose_ref_cache(&ref_cache);3044if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||3045(strcmp(lock->ref_name, lock->orig_ref_name) &&3046log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {3047unlock_ref(lock);3048return-1;3049}3050if(strcmp(lock->orig_ref_name,"HEAD") !=0) {3051/*3052 * Special hack: If a branch is updated directly and HEAD3053 * points to it (may happen on the remote side of a push3054 * for example) then logically the HEAD reflog should be3055 * updated too.3056 * A generic solution implies reverse symref information,3057 * but finding all symrefs pointing to the given branch3058 * would be rather costly for this rare event (the direct3059 * update of a branch) to be worth it. So let's cheat and3060 * check with HEAD only which should cover 99% of all usage3061 * scenarios (even 100% of the default ones).3062 */3063unsigned char head_sha1[20];3064int head_flag;3065const char*head_ref;3066 head_ref =resolve_ref_unsafe("HEAD", head_sha1,1, &head_flag);3067if(head_ref && (head_flag & REF_ISSYMREF) &&3068!strcmp(head_ref, lock->ref_name))3069log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3070}3071if(commit_ref(lock)) {3072error("Couldn't set%s", lock->ref_name);3073unlock_ref(lock);3074return-1;3075}3076unlock_ref(lock);3077return0;3078}30793080intcreate_symref(const char*ref_target,const char*refs_heads_master,3081const char*logmsg)3082{3083const char*lockpath;3084char ref[1000];3085int fd, len, written;3086char*git_HEAD =git_pathdup("%s", ref_target);3087unsigned char old_sha1[20], new_sha1[20];30883089if(logmsg &&read_ref(ref_target, old_sha1))3090hashclr(old_sha1);30913092if(safe_create_leading_directories(git_HEAD) <0)3093returnerror("unable to create directory for%s", git_HEAD);30943095#ifndef NO_SYMLINK_HEAD3096if(prefer_symlink_refs) {3097unlink(git_HEAD);3098if(!symlink(refs_heads_master, git_HEAD))3099goto done;3100fprintf(stderr,"no symlink - falling back to symbolic ref\n");3101}3102#endif31033104 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);3105if(sizeof(ref) <= len) {3106error("refname too long:%s", refs_heads_master);3107goto error_free_return;3108}3109 lockpath =mkpath("%s.lock", git_HEAD);3110 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);3111if(fd <0) {3112error("Unable to open%sfor writing", lockpath);3113goto error_free_return;3114}3115 written =write_in_full(fd, ref, len);3116if(close(fd) !=0|| written != len) {3117error("Unable to write to%s", lockpath);3118goto error_unlink_return;3119}3120if(rename(lockpath, git_HEAD) <0) {3121error("Unable to create%s", git_HEAD);3122goto error_unlink_return;3123}3124if(adjust_shared_perm(git_HEAD)) {3125error("Unable to fix permissions on%s", lockpath);3126 error_unlink_return:3127unlink_or_warn(lockpath);3128 error_free_return:3129free(git_HEAD);3130return-1;3131}31323133#ifndef NO_SYMLINK_HEAD3134 done:3135#endif3136if(logmsg && !read_ref(refs_heads_master, new_sha1))3137log_ref_write(ref_target, old_sha1, new_sha1, logmsg);31383139free(git_HEAD);3140return0;3141}31423143static char*ref_msg(const char*line,const char*endp)3144{3145const char*ep;3146 line +=82;3147 ep =memchr(line,'\n', endp - line);3148if(!ep)3149 ep = endp;3150returnxmemdupz(line, ep - line);3151}31523153intread_ref_at(const char*refname,unsigned long at_time,int cnt,3154unsigned char*sha1,char**msg,3155unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)3156{3157const char*logfile, *logdata, *logend, *rec, *lastgt, *lastrec;3158char*tz_c;3159int logfd, tz, reccnt =0;3160struct stat st;3161unsigned long date;3162unsigned char logged_sha1[20];3163void*log_mapped;3164size_t mapsz;31653166 logfile =git_path("logs/%s", refname);3167 logfd =open(logfile, O_RDONLY,0);3168if(logfd <0)3169die_errno("Unable to read log '%s'", logfile);3170fstat(logfd, &st);3171if(!st.st_size)3172die("Log%sis empty.", logfile);3173 mapsz =xsize_t(st.st_size);3174 log_mapped =xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd,0);3175 logdata = log_mapped;3176close(logfd);31773178 lastrec = NULL;3179 rec = logend = logdata + st.st_size;3180while(logdata < rec) {3181 reccnt++;3182if(logdata < rec && *(rec-1) =='\n')3183 rec--;3184 lastgt = NULL;3185while(logdata < rec && *(rec-1) !='\n') {3186 rec--;3187if(*rec =='>')3188 lastgt = rec;3189}3190if(!lastgt)3191die("Log%sis corrupt.", logfile);3192 date =strtoul(lastgt +1, &tz_c,10);3193if(date <= at_time || cnt ==0) {3194 tz =strtoul(tz_c, NULL,10);3195if(msg)3196*msg =ref_msg(rec, logend);3197if(cutoff_time)3198*cutoff_time = date;3199if(cutoff_tz)3200*cutoff_tz = tz;3201if(cutoff_cnt)3202*cutoff_cnt = reccnt -1;3203if(lastrec) {3204if(get_sha1_hex(lastrec, logged_sha1))3205die("Log%sis corrupt.", logfile);3206if(get_sha1_hex(rec +41, sha1))3207die("Log%sis corrupt.", logfile);3208if(hashcmp(logged_sha1, sha1)) {3209warning("Log%shas gap after%s.",3210 logfile,show_date(date, tz, DATE_RFC2822));3211}3212}3213else if(date == at_time) {3214if(get_sha1_hex(rec +41, sha1))3215die("Log%sis corrupt.", logfile);3216}3217else{3218if(get_sha1_hex(rec +41, logged_sha1))3219die("Log%sis corrupt.", logfile);3220if(hashcmp(logged_sha1, sha1)) {3221warning("Log%sunexpectedly ended on%s.",3222 logfile,show_date(date, tz, DATE_RFC2822));3223}3224}3225munmap(log_mapped, mapsz);3226return0;3227}3228 lastrec = rec;3229if(cnt >0)3230 cnt--;3231}32323233 rec = logdata;3234while(rec < logend && *rec !='>'&& *rec !='\n')3235 rec++;3236if(rec == logend || *rec =='\n')3237die("Log%sis corrupt.", logfile);3238 date =strtoul(rec +1, &tz_c,10);3239 tz =strtoul(tz_c, NULL,10);3240if(get_sha1_hex(logdata, sha1))3241die("Log%sis corrupt.", logfile);3242if(is_null_sha1(sha1)) {3243if(get_sha1_hex(logdata +41, sha1))3244die("Log%sis corrupt.", logfile);3245}3246if(msg)3247*msg =ref_msg(logdata, logend);3248munmap(log_mapped, mapsz);32493250if(cutoff_time)3251*cutoff_time = date;3252if(cutoff_tz)3253*cutoff_tz = tz;3254if(cutoff_cnt)3255*cutoff_cnt = reccnt;3256return1;3257}32583259static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3260{3261unsigned char osha1[20], nsha1[20];3262char*email_end, *message;3263unsigned long timestamp;3264int tz;32653266/* old SP new SP name <email> SP time TAB msg LF */3267if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3268get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3269get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3270!(email_end =strchr(sb->buf +82,'>')) ||3271 email_end[1] !=' '||3272!(timestamp =strtoul(email_end +2, &message,10)) ||3273!message || message[0] !=' '||3274(message[1] !='+'&& message[1] !='-') ||3275!isdigit(message[2]) || !isdigit(message[3]) ||3276!isdigit(message[4]) || !isdigit(message[5]))3277return0;/* corrupt? */3278 email_end[1] ='\0';3279 tz =strtol(message +1, NULL,10);3280if(message[6] !='\t')3281 message +=6;3282else3283 message +=7;3284returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3285}32863287static char*find_beginning_of_line(char*bob,char*scan)3288{3289while(bob < scan && *(--scan) !='\n')3290;/* keep scanning backwards */3291/*3292 * Return either beginning of the buffer, or LF at the end of3293 * the previous line.3294 */3295return scan;3296}32973298intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3299{3300struct strbuf sb = STRBUF_INIT;3301FILE*logfp;3302long pos;3303int ret =0, at_tail =1;33043305 logfp =fopen(git_path("logs/%s", refname),"r");3306if(!logfp)3307return-1;33083309/* Jump to the end */3310if(fseek(logfp,0, SEEK_END) <0)3311returnerror("cannot seek back reflog for%s:%s",3312 refname,strerror(errno));3313 pos =ftell(logfp);3314while(!ret &&0< pos) {3315int cnt;3316size_t nread;3317char buf[BUFSIZ];3318char*endp, *scanp;33193320/* Fill next block from the end */3321 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3322if(fseek(logfp, pos - cnt, SEEK_SET))3323returnerror("cannot seek back reflog for%s:%s",3324 refname,strerror(errno));3325 nread =fread(buf, cnt,1, logfp);3326if(nread !=1)3327returnerror("cannot read%dbytes from reflog for%s:%s",3328 cnt, refname,strerror(errno));3329 pos -= cnt;33303331 scanp = endp = buf + cnt;3332if(at_tail && scanp[-1] =='\n')3333/* Looking at the final LF at the end of the file */3334 scanp--;3335 at_tail =0;33363337while(buf < scanp) {3338/*3339 * terminating LF of the previous line, or the beginning3340 * of the buffer.3341 */3342char*bp;33433344 bp =find_beginning_of_line(buf, scanp);33453346if(*bp !='\n') {3347strbuf_splice(&sb,0,0, buf, endp - buf);3348if(pos)3349break;/* need to fill another block */3350 scanp = buf -1;/* leave loop */3351}else{3352/*3353 * (bp + 1) thru endp is the beginning of the3354 * current line we have in sb3355 */3356strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3357 scanp = bp;3358 endp = bp +1;3359}3360 ret =show_one_reflog_ent(&sb, fn, cb_data);3361strbuf_reset(&sb);3362if(ret)3363break;3364}33653366}3367if(!ret && sb.len)3368 ret =show_one_reflog_ent(&sb, fn, cb_data);33693370fclose(logfp);3371strbuf_release(&sb);3372return ret;3373}33743375intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3376{3377FILE*logfp;3378struct strbuf sb = STRBUF_INIT;3379int ret =0;33803381 logfp =fopen(git_path("logs/%s", refname),"r");3382if(!logfp)3383return-1;33843385while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3386 ret =show_one_reflog_ent(&sb, fn, cb_data);3387fclose(logfp);3388strbuf_release(&sb);3389return ret;3390}3391/*3392 * Call fn for each reflog in the namespace indicated by name. name3393 * must be empty or end with '/'. Name will be used as a scratch3394 * space, but its contents will be restored before return.3395 */3396static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3397{3398DIR*d =opendir(git_path("logs/%s", name->buf));3399int retval =0;3400struct dirent *de;3401int oldlen = name->len;34023403if(!d)3404return name->len ? errno :0;34053406while((de =readdir(d)) != NULL) {3407struct stat st;34083409if(de->d_name[0] =='.')3410continue;3411if(has_extension(de->d_name,".lock"))3412continue;3413strbuf_addstr(name, de->d_name);3414if(stat(git_path("logs/%s", name->buf), &st) <0) {3415;/* silently ignore */3416}else{3417if(S_ISDIR(st.st_mode)) {3418strbuf_addch(name,'/');3419 retval =do_for_each_reflog(name, fn, cb_data);3420}else{3421unsigned char sha1[20];3422if(read_ref_full(name->buf, sha1,0, NULL))3423 retval =error("bad ref for%s", name->buf);3424else3425 retval =fn(name->buf, sha1,0, cb_data);3426}3427if(retval)3428break;3429}3430strbuf_setlen(name, oldlen);3431}3432closedir(d);3433return retval;3434}34353436intfor_each_reflog(each_ref_fn fn,void*cb_data)3437{3438int retval;3439struct strbuf name;3440strbuf_init(&name, PATH_MAX);3441 retval =do_for_each_reflog(&name, fn, cb_data);3442strbuf_release(&name);3443return retval;3444}34453446static struct ref_lock *update_ref_lock(const char*refname,3447const unsigned char*oldval,3448int flags,int*type_p,3449enum action_on_err onerr)3450{3451struct ref_lock *lock;3452 lock =lock_any_ref_for_update(refname, oldval, flags, type_p);3453if(!lock) {3454const char*str ="Cannot lock the ref '%s'.";3455switch(onerr) {3456case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3457case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3458case UPDATE_REFS_QUIET_ON_ERR:break;3459}3460}3461return lock;3462}34633464static intupdate_ref_write(const char*action,const char*refname,3465const unsigned char*sha1,struct ref_lock *lock,3466enum action_on_err onerr)3467{3468if(write_ref_sha1(lock, sha1, action) <0) {3469const char*str ="Cannot update the ref '%s'.";3470switch(onerr) {3471case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3472case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3473case UPDATE_REFS_QUIET_ON_ERR:break;3474}3475return1;3476}3477return0;3478}34793480/**3481 * Information needed for a single ref update. Set new_sha1 to the3482 * new value or to zero to delete the ref. To check the old value3483 * while locking the ref, set have_old to 1 and set old_sha1 to the3484 * value or to zero to ensure the ref does not exist before update.3485 */3486struct ref_update {3487unsigned char new_sha1[20];3488unsigned char old_sha1[20];3489int flags;/* REF_NODEREF? */3490int have_old;/* 1 if old_sha1 is valid, 0 otherwise */3491struct ref_lock *lock;3492int type;3493const char refname[FLEX_ARRAY];3494};34953496/*3497 * Data structure for holding a reference transaction, which can3498 * consist of checks and updates to multiple references, carried out3499 * as atomically as possible. This structure is opaque to callers.3500 */3501struct ref_transaction {3502struct ref_update **updates;3503size_t alloc;3504size_t nr;3505};35063507struct ref_transaction *ref_transaction_begin(void)3508{3509returnxcalloc(1,sizeof(struct ref_transaction));3510}35113512static voidref_transaction_free(struct ref_transaction *transaction)3513{3514int i;35153516for(i =0; i < transaction->nr; i++)3517free(transaction->updates[i]);35183519free(transaction->updates);3520free(transaction);3521}35223523voidref_transaction_rollback(struct ref_transaction *transaction)3524{3525ref_transaction_free(transaction);3526}35273528static struct ref_update *add_update(struct ref_transaction *transaction,3529const char*refname)3530{3531size_t len =strlen(refname);3532struct ref_update *update =xcalloc(1,sizeof(*update) + len +1);35333534strcpy((char*)update->refname, refname);3535ALLOC_GROW(transaction->updates, transaction->nr +1, transaction->alloc);3536 transaction->updates[transaction->nr++] = update;3537return update;3538}35393540voidref_transaction_update(struct ref_transaction *transaction,3541const char*refname,3542unsigned char*new_sha1,unsigned char*old_sha1,3543int flags,int have_old)3544{3545struct ref_update *update =add_update(transaction, refname);35463547hashcpy(update->new_sha1, new_sha1);3548 update->flags = flags;3549 update->have_old = have_old;3550if(have_old)3551hashcpy(update->old_sha1, old_sha1);3552}35533554voidref_transaction_create(struct ref_transaction *transaction,3555const char*refname,3556unsigned char*new_sha1,3557int flags)3558{3559struct ref_update *update =add_update(transaction, refname);35603561assert(!is_null_sha1(new_sha1));3562hashcpy(update->new_sha1, new_sha1);3563hashclr(update->old_sha1);3564 update->flags = flags;3565 update->have_old =1;3566}35673568voidref_transaction_delete(struct ref_transaction *transaction,3569const char*refname,3570unsigned char*old_sha1,3571int flags,int have_old)3572{3573struct ref_update *update =add_update(transaction, refname);35743575 update->flags = flags;3576 update->have_old = have_old;3577if(have_old) {3578assert(!is_null_sha1(old_sha1));3579hashcpy(update->old_sha1, old_sha1);3580}3581}35823583intupdate_ref(const char*action,const char*refname,3584const unsigned char*sha1,const unsigned char*oldval,3585int flags,enum action_on_err onerr)3586{3587struct ref_lock *lock;3588 lock =update_ref_lock(refname, oldval, flags, NULL, onerr);3589if(!lock)3590return1;3591returnupdate_ref_write(action, refname, sha1, lock, onerr);3592}35933594static intref_update_compare(const void*r1,const void*r2)3595{3596const struct ref_update *const*u1 = r1;3597const struct ref_update *const*u2 = r2;3598returnstrcmp((*u1)->refname, (*u2)->refname);3599}36003601static intref_update_reject_duplicates(struct ref_update **updates,int n,3602enum action_on_err onerr)3603{3604int i;3605for(i =1; i < n; i++)3606if(!strcmp(updates[i -1]->refname, updates[i]->refname)) {3607const char*str =3608"Multiple updates for ref '%s' not allowed.";3609switch(onerr) {3610case UPDATE_REFS_MSG_ON_ERR:3611error(str, updates[i]->refname);break;3612case UPDATE_REFS_DIE_ON_ERR:3613die(str, updates[i]->refname);break;3614case UPDATE_REFS_QUIET_ON_ERR:3615break;3616}3617return1;3618}3619return0;3620}36213622intref_transaction_commit(struct ref_transaction *transaction,3623const char*msg,enum action_on_err onerr)3624{3625int ret =0, delnum =0, i;3626const char**delnames;3627int n = transaction->nr;3628struct ref_update **updates = transaction->updates;36293630if(!n)3631return0;36323633/* Allocate work space */3634 delnames =xmalloc(sizeof(*delnames) * n);36353636/* Copy, sort, and reject duplicate refs */3637qsort(updates, n,sizeof(*updates), ref_update_compare);3638 ret =ref_update_reject_duplicates(updates, n, onerr);3639if(ret)3640goto cleanup;36413642/* Acquire all locks while verifying old values */3643for(i =0; i < n; i++) {3644struct ref_update *update = updates[i];36453646 update->lock =update_ref_lock(update->refname,3647(update->have_old ?3648 update->old_sha1 : NULL),3649 update->flags,3650&update->type, onerr);3651if(!update->lock) {3652 ret =1;3653goto cleanup;3654}3655}36563657/* Perform updates first so live commits remain referenced */3658for(i =0; i < n; i++) {3659struct ref_update *update = updates[i];36603661if(!is_null_sha1(update->new_sha1)) {3662 ret =update_ref_write(msg,3663 update->refname,3664 update->new_sha1,3665 update->lock, onerr);3666 update->lock = NULL;/* freed by update_ref_write */3667if(ret)3668goto cleanup;3669}3670}36713672/* Perform deletes now that updates are safely completed */3673for(i =0; i < n; i++) {3674struct ref_update *update = updates[i];36753676if(update->lock) {3677 delnames[delnum++] = update->lock->ref_name;3678 ret |=delete_ref_loose(update->lock, update->type);3679}3680}36813682 ret |=repack_without_refs(delnames, delnum);3683for(i =0; i < delnum; i++)3684unlink_or_warn(git_path("logs/%s", delnames[i]));3685clear_loose_ref_cache(&ref_cache);36863687cleanup:3688for(i =0; i < n; i++)3689if(updates[i]->lock)3690unlock_ref(updates[i]->lock);3691free(delnames);3692ref_transaction_free(transaction);3693return ret;3694}36953696char*shorten_unambiguous_ref(const char*refname,int strict)3697{3698int i;3699static char**scanf_fmts;3700static int nr_rules;3701char*short_name;37023703if(!nr_rules) {3704/*3705 * Pre-generate scanf formats from ref_rev_parse_rules[].3706 * Generate a format suitable for scanf from a3707 * ref_rev_parse_rules rule by interpolating "%s" at the3708 * location of the "%.*s".3709 */3710size_t total_len =0;3711size_t offset =0;37123713/* the rule list is NULL terminated, count them first */3714for(nr_rules =0; ref_rev_parse_rules[nr_rules]; nr_rules++)3715/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3716 total_len +=strlen(ref_rev_parse_rules[nr_rules]) -2+1;37173718 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);37193720 offset =0;3721for(i =0; i < nr_rules; i++) {3722assert(offset < total_len);3723 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules] + offset;3724 offset +=snprintf(scanf_fmts[i], total_len - offset,3725 ref_rev_parse_rules[i],2,"%s") +1;3726}3727}37283729/* bail out if there are no rules */3730if(!nr_rules)3731returnxstrdup(refname);37323733/* buffer for scanf result, at most refname must fit */3734 short_name =xstrdup(refname);37353736/* skip first rule, it will always match */3737for(i = nr_rules -1; i >0; --i) {3738int j;3739int rules_to_fail = i;3740int short_name_len;37413742if(1!=sscanf(refname, scanf_fmts[i], short_name))3743continue;37443745 short_name_len =strlen(short_name);37463747/*3748 * in strict mode, all (except the matched one) rules3749 * must fail to resolve to a valid non-ambiguous ref3750 */3751if(strict)3752 rules_to_fail = nr_rules;37533754/*3755 * check if the short name resolves to a valid ref,3756 * but use only rules prior to the matched one3757 */3758for(j =0; j < rules_to_fail; j++) {3759const char*rule = ref_rev_parse_rules[j];3760char refname[PATH_MAX];37613762/* skip matched rule */3763if(i == j)3764continue;37653766/*3767 * the short name is ambiguous, if it resolves3768 * (with this previous rule) to a valid ref3769 * read_ref() returns 0 on success3770 */3771mksnpath(refname,sizeof(refname),3772 rule, short_name_len, short_name);3773if(ref_exists(refname))3774break;3775}37763777/*3778 * short name is non-ambiguous if all previous rules3779 * haven't resolved to a valid ref3780 */3781if(j == rules_to_fail)3782return short_name;3783}37843785free(short_name);3786returnxstrdup(refname);3787}37883789static struct string_list *hide_refs;37903791intparse_hide_refs_config(const char*var,const char*value,const char*section)3792{3793if(!strcmp("transfer.hiderefs", var) ||3794/* NEEDSWORK: use parse_config_key() once both are merged */3795(starts_with(var, section) && var[strlen(section)] =='.'&&3796!strcmp(var +strlen(section),".hiderefs"))) {3797char*ref;3798int len;37993800if(!value)3801returnconfig_error_nonbool(var);3802 ref =xstrdup(value);3803 len =strlen(ref);3804while(len && ref[len -1] =='/')3805 ref[--len] ='\0';3806if(!hide_refs) {3807 hide_refs =xcalloc(1,sizeof(*hide_refs));3808 hide_refs->strdup_strings =1;3809}3810string_list_append(hide_refs, ref);3811}3812return0;3813}38143815intref_is_hidden(const char*refname)3816{3817struct string_list_item *item;38183819if(!hide_refs)3820return0;3821for_each_string_list_item(item, hide_refs) {3822int len;3823if(!starts_with(refname, item->string))3824continue;3825 len =strlen(item->string);3826if(!refname[len] || refname[len] =='/')3827return1;3828}3829return0;3830}