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; 156 157if(refname[0] ==0|| refname[0] =='/') { 158/* entirely empty ref or initial ref component */ 159return-1; 160} 161 162/* 163 * Initial ref component of '.'; below we look for /. so we'll 164 * miss this. 165 */ 166if(refname[0] =='.') { 167if(refname[1] =='/'|| refname[1] =='\0') 168return-1; 169if(!(flags & REFNAME_DOT_COMPONENT)) 170return-1; 171} 172while(1) { 173 __m128i tmp, tmp1, result; 174uint64_t mask; 175 176if((uintptr_t) cp % PAGE_SIZE > PAGE_SIZE - SSE_VECTOR_BYTES -1) 177/* 178 * End-of-page; fall back to slow method for 179 * this entire ref. 180 */ 181returncheck_refname_format_bytewise(refname, flags); 182 183 tmp =_mm_loadu_si128((__m128i *)cp); 184 tmp1 =_mm_loadu_si128((__m128i *)(cp +1)); 185 186/* 187 * This range (note the lt) contains some 188 * permissible-but-rare characters (including all 189 * characters >= 128), which we handle later. It also 190 * includes \000. 191 */ 192 result =_mm_cmplt_epi8(tmp, star_ub); 193 194 result =_mm_or_si128(result,_mm_cmpeq_epi8(tmp, question)); 195 result =_mm_or_si128(result,_mm_cmpeq_epi8(tmp, colon)); 196 197/* This range contains the permissible ] as bycatch */ 198 result =_mm_or_si128(result,_mm_and_si128( 199_mm_cmpgt_epi8(tmp, bracket_lb), 200_mm_cmplt_epi8(tmp, caret_ub))); 201 202 result =_mm_or_si128(result,_mm_cmpgt_epi8(tmp, tilde_lb)); 203 204/* .. */ 205 result =_mm_or_si128(result,_mm_and_si128( 206_mm_cmpeq_epi8(tmp, dot), 207_mm_cmpeq_epi8(tmp1, dot))); 208/* @{ */ 209 result =_mm_or_si128(result,_mm_and_si128( 210_mm_cmpeq_epi8(tmp, at), 211_mm_cmpeq_epi8(tmp1, curly))); 212/* // */ 213 result =_mm_or_si128(result,_mm_and_si128( 214_mm_cmpeq_epi8(tmp, slash), 215_mm_cmpeq_epi8(tmp1, slash))); 216/* trailing / */ 217 result =_mm_or_si128(result,_mm_and_si128( 218_mm_cmpeq_epi8(tmp, slash), 219_mm_cmpeq_epi8(tmp1, zero))); 220/* .l, beginning of .lock */ 221 result =_mm_or_si128(result,_mm_and_si128( 222_mm_cmpeq_epi8(tmp, dot), 223_mm_cmpeq_epi8(tmp1, el))); 224/* 225 * Even though /. is not necessarily an error, we flag 226 * it anyway. If we find it, we'll check if it's valid 227 * and if so we'll advance just past it. 228 */ 229 result =_mm_or_si128(result,_mm_and_si128( 230_mm_cmpeq_epi8(tmp, slash), 231_mm_cmpeq_epi8(tmp1, dot))); 232 233 mask =_mm_movemask_epi8(result); 234if(mask) { 235/* 236 * We've found either end-of-string, or some 237 * probably-bad character or substring. 238 */ 239int i =__builtin_ctz(mask); 240switch(refname_disposition[cp[i] &255]) { 241case0:/* fall-through */ 242case5: 243/* 244 * bycatch: a good character that's in 245 * one of the ranges of mostly-forbidden 246 * characters 247 */ 248 cp += i +1; 249break; 250case1: 251if(cp[i +1] =='{') 252return-1; 253 cp += i +1; 254break; 255case2: 256if(!(flags & REFNAME_ALLOW_ONELEVEL) 257&& !component_count && !strchr(refname,'/')) 258/* Refname has only one component. */ 259return-1; 260return0; 261case3: 262 component_count ++; 263/* 264 * Even if leading dots are allowed, don't 265 * allow "." as a component (".." is 266 * prevented by case 4 below). 267 */ 268if(cp[i +1] =='.') { 269if(cp[i +2] =='\0') 270return-1; 271if(flags & REFNAME_DOT_COMPONENT) { 272/* skip to just after the /. */ 273 cp += i +2; 274break; 275} 276return-1; 277}else if(cp[i +1] =='/'|| cp[i +1] =='\0') 278return-1; 279break; 280case4: 281if(cp[i +1] =='.'|| cp[i +1] =='\0') 282return-1; 283/* .lock as end-of-component or end-of-string */ 284if((!strncmp(cp + i,".lock",5)) 285&& (cp[i +5] =='/'|| cp[i +5] ==0)) 286return-1; 287 cp +=1; 288break; 289case6: 290if(((cp == refname + i) || cp[i -1] =='/') 291&& (cp[i +1] =='/'|| cp[i +1] ==0)) 292if(flags & REFNAME_REFSPEC_PATTERN) { 293 flags &= ~REFNAME_REFSPEC_PATTERN; 294/* restart after the * */ 295 cp += i +1; 296continue; 297} 298/* fall-through */ 299case7: 300return-1; 301} 302}else 303 cp += SSE_VECTOR_BYTES; 304} 305} 306 307#else 308 309intcheck_refname_format(const char*refname,int flags) 310{ 311returncheck_refname_format_bytewise(refname, flags); 312} 313 314#endif 315 316struct ref_entry; 317 318/* 319 * Information used (along with the information in ref_entry) to 320 * describe a single cached reference. This data structure only 321 * occurs embedded in a union in struct ref_entry, and only when 322 * (ref_entry->flag & REF_DIR) is zero. 323 */ 324struct ref_value { 325/* 326 * The name of the object to which this reference resolves 327 * (which may be a tag object). If REF_ISBROKEN, this is 328 * null. If REF_ISSYMREF, then this is the name of the object 329 * referred to by the last reference in the symlink chain. 330 */ 331unsigned char sha1[20]; 332 333/* 334 * If REF_KNOWS_PEELED, then this field holds the peeled value 335 * of this reference, or null if the reference is known not to 336 * be peelable. See the documentation for peel_ref() for an 337 * exact definition of "peelable". 338 */ 339unsigned char peeled[20]; 340}; 341 342struct ref_cache; 343 344/* 345 * Information used (along with the information in ref_entry) to 346 * describe a level in the hierarchy of references. This data 347 * structure only occurs embedded in a union in struct ref_entry, and 348 * only when (ref_entry.flag & REF_DIR) is set. In that case, 349 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 350 * in the directory have already been read: 351 * 352 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 353 * or packed references, already read. 354 * 355 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 356 * references that hasn't been read yet (nor has any of its 357 * subdirectories). 358 * 359 * Entries within a directory are stored within a growable array of 360 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 361 * sorted are sorted by their component name in strcmp() order and the 362 * remaining entries are unsorted. 363 * 364 * Loose references are read lazily, one directory at a time. When a 365 * directory of loose references is read, then all of the references 366 * in that directory are stored, and REF_INCOMPLETE stubs are created 367 * for any subdirectories, but the subdirectories themselves are not 368 * read. The reading is triggered by get_ref_dir(). 369 */ 370struct ref_dir { 371int nr, alloc; 372 373/* 374 * Entries with index 0 <= i < sorted are sorted by name. New 375 * entries are appended to the list unsorted, and are sorted 376 * only when required; thus we avoid the need to sort the list 377 * after the addition of every reference. 378 */ 379int sorted; 380 381/* A pointer to the ref_cache that contains this ref_dir. */ 382struct ref_cache *ref_cache; 383 384struct ref_entry **entries; 385}; 386 387/* 388 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 389 * REF_ISPACKED=0x02, and REF_ISBROKEN=0x04 are public values; see 390 * refs.h. 391 */ 392 393/* 394 * The field ref_entry->u.value.peeled of this value entry contains 395 * the correct peeled value for the reference, which might be 396 * null_sha1 if the reference is not a tag or if it is broken. 397 */ 398#define REF_KNOWS_PEELED 0x08 399 400/* ref_entry represents a directory of references */ 401#define REF_DIR 0x10 402 403/* 404 * Entry has not yet been read from disk (used only for REF_DIR 405 * entries representing loose references) 406 */ 407#define REF_INCOMPLETE 0x20 408 409/* 410 * A ref_entry represents either a reference or a "subdirectory" of 411 * references. 412 * 413 * Each directory in the reference namespace is represented by a 414 * ref_entry with (flags & REF_DIR) set and containing a subdir member 415 * that holds the entries in that directory that have been read so 416 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 417 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 418 * used for loose reference directories. 419 * 420 * References are represented by a ref_entry with (flags & REF_DIR) 421 * unset and a value member that describes the reference's value. The 422 * flag member is at the ref_entry level, but it is also needed to 423 * interpret the contents of the value field (in other words, a 424 * ref_value object is not very much use without the enclosing 425 * ref_entry). 426 * 427 * Reference names cannot end with slash and directories' names are 428 * always stored with a trailing slash (except for the top-level 429 * directory, which is always denoted by ""). This has two nice 430 * consequences: (1) when the entries in each subdir are sorted 431 * lexicographically by name (as they usually are), the references in 432 * a whole tree can be generated in lexicographic order by traversing 433 * the tree in left-to-right, depth-first order; (2) the names of 434 * references and subdirectories cannot conflict, and therefore the 435 * presence of an empty subdirectory does not block the creation of a 436 * similarly-named reference. (The fact that reference names with the 437 * same leading components can conflict *with each other* is a 438 * separate issue that is regulated by is_refname_available().) 439 * 440 * Please note that the name field contains the fully-qualified 441 * reference (or subdirectory) name. Space could be saved by only 442 * storing the relative names. But that would require the full names 443 * to be generated on the fly when iterating in do_for_each_ref(), and 444 * would break callback functions, who have always been able to assume 445 * that the name strings that they are passed will not be freed during 446 * the iteration. 447 */ 448struct ref_entry { 449unsigned char flag;/* ISSYMREF? ISPACKED? */ 450union{ 451struct ref_value value;/* if not (flags&REF_DIR) */ 452struct ref_dir subdir;/* if (flags&REF_DIR) */ 453} u; 454/* 455 * The full name of the reference (e.g., "refs/heads/master") 456 * or the full name of the directory with a trailing slash 457 * (e.g., "refs/heads/"): 458 */ 459char name[FLEX_ARRAY]; 460}; 461 462static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 463 464static struct ref_dir *get_ref_dir(struct ref_entry *entry) 465{ 466struct ref_dir *dir; 467assert(entry->flag & REF_DIR); 468 dir = &entry->u.subdir; 469if(entry->flag & REF_INCOMPLETE) { 470read_loose_refs(entry->name, dir); 471 entry->flag &= ~REF_INCOMPLETE; 472} 473return dir; 474} 475 476static struct ref_entry *create_ref_entry(const char*refname, 477const unsigned char*sha1,int flag, 478int check_name) 479{ 480int len; 481struct ref_entry *ref; 482 483if(check_name && 484check_refname_format(refname, REFNAME_ALLOW_ONELEVEL|REFNAME_DOT_COMPONENT)) 485die("Reference has invalid format: '%s'", refname); 486 len =strlen(refname) +1; 487 ref =xmalloc(sizeof(struct ref_entry) + len); 488hashcpy(ref->u.value.sha1, sha1); 489hashclr(ref->u.value.peeled); 490memcpy(ref->name, refname, len); 491 ref->flag = flag; 492return ref; 493} 494 495static voidclear_ref_dir(struct ref_dir *dir); 496 497static voidfree_ref_entry(struct ref_entry *entry) 498{ 499if(entry->flag & REF_DIR) { 500/* 501 * Do not use get_ref_dir() here, as that might 502 * trigger the reading of loose refs. 503 */ 504clear_ref_dir(&entry->u.subdir); 505} 506free(entry); 507} 508 509/* 510 * Add a ref_entry to the end of dir (unsorted). Entry is always 511 * stored directly in dir; no recursion into subdirectories is 512 * done. 513 */ 514static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 515{ 516ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 517 dir->entries[dir->nr++] = entry; 518/* optimize for the case that entries are added in order */ 519if(dir->nr ==1|| 520(dir->nr == dir->sorted +1&& 521strcmp(dir->entries[dir->nr -2]->name, 522 dir->entries[dir->nr -1]->name) <0)) 523 dir->sorted = dir->nr; 524} 525 526/* 527 * Clear and free all entries in dir, recursively. 528 */ 529static voidclear_ref_dir(struct ref_dir *dir) 530{ 531int i; 532for(i =0; i < dir->nr; i++) 533free_ref_entry(dir->entries[i]); 534free(dir->entries); 535 dir->sorted = dir->nr = dir->alloc =0; 536 dir->entries = NULL; 537} 538 539/* 540 * Create a struct ref_entry object for the specified dirname. 541 * dirname is the name of the directory with a trailing slash (e.g., 542 * "refs/heads/") or "" for the top-level directory. 543 */ 544static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 545const char*dirname,size_t len, 546int incomplete) 547{ 548struct ref_entry *direntry; 549 direntry =xcalloc(1,sizeof(struct ref_entry) + len +1); 550memcpy(direntry->name, dirname, len); 551 direntry->name[len] ='\0'; 552 direntry->u.subdir.ref_cache = ref_cache; 553 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 554return direntry; 555} 556 557static intref_entry_cmp(const void*a,const void*b) 558{ 559struct ref_entry *one = *(struct ref_entry **)a; 560struct ref_entry *two = *(struct ref_entry **)b; 561returnstrcmp(one->name, two->name); 562} 563 564static voidsort_ref_dir(struct ref_dir *dir); 565 566struct string_slice { 567size_t len; 568const char*str; 569}; 570 571static intref_entry_cmp_sslice(const void*key_,const void*ent_) 572{ 573const struct string_slice *key = key_; 574const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 575int cmp =strncmp(key->str, ent->name, key->len); 576if(cmp) 577return cmp; 578return'\0'- (unsigned char)ent->name[key->len]; 579} 580 581/* 582 * Return the index of the entry with the given refname from the 583 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 584 * no such entry is found. dir must already be complete. 585 */ 586static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 587{ 588struct ref_entry **r; 589struct string_slice key; 590 591if(refname == NULL || !dir->nr) 592return-1; 593 594sort_ref_dir(dir); 595 key.len = len; 596 key.str = refname; 597 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 598 ref_entry_cmp_sslice); 599 600if(r == NULL) 601return-1; 602 603return r - dir->entries; 604} 605 606/* 607 * Search for a directory entry directly within dir (without 608 * recursing). Sort dir if necessary. subdirname must be a directory 609 * name (i.e., end in '/'). If mkdir is set, then create the 610 * directory if it is missing; otherwise, return NULL if the desired 611 * directory cannot be found. dir must already be complete. 612 */ 613static struct ref_dir *search_for_subdir(struct ref_dir *dir, 614const char*subdirname,size_t len, 615int mkdir) 616{ 617int entry_index =search_ref_dir(dir, subdirname, len); 618struct ref_entry *entry; 619if(entry_index == -1) { 620if(!mkdir) 621return NULL; 622/* 623 * Since dir is complete, the absence of a subdir 624 * means that the subdir really doesn't exist; 625 * therefore, create an empty record for it but mark 626 * the record complete. 627 */ 628 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 629add_entry_to_dir(dir, entry); 630}else{ 631 entry = dir->entries[entry_index]; 632} 633returnget_ref_dir(entry); 634} 635 636/* 637 * If refname is a reference name, find the ref_dir within the dir 638 * tree that should hold refname. If refname is a directory name 639 * (i.e., ends in '/'), then return that ref_dir itself. dir must 640 * represent the top-level directory and must already be complete. 641 * Sort ref_dirs and recurse into subdirectories as necessary. If 642 * mkdir is set, then create any missing directories; otherwise, 643 * return NULL if the desired directory cannot be found. 644 */ 645static struct ref_dir *find_containing_dir(struct ref_dir *dir, 646const char*refname,int mkdir) 647{ 648const char*slash; 649for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 650size_t dirnamelen = slash - refname +1; 651struct ref_dir *subdir; 652 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 653if(!subdir) { 654 dir = NULL; 655break; 656} 657 dir = subdir; 658} 659 660return dir; 661} 662 663/* 664 * Find the value entry with the given name in dir, sorting ref_dirs 665 * and recursing into subdirectories as necessary. If the name is not 666 * found or it corresponds to a directory entry, return NULL. 667 */ 668static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 669{ 670int entry_index; 671struct ref_entry *entry; 672 dir =find_containing_dir(dir, refname,0); 673if(!dir) 674return NULL; 675 entry_index =search_ref_dir(dir, refname,strlen(refname)); 676if(entry_index == -1) 677return NULL; 678 entry = dir->entries[entry_index]; 679return(entry->flag & REF_DIR) ? NULL : entry; 680} 681 682/* 683 * Remove the entry with the given name from dir, recursing into 684 * subdirectories as necessary. If refname is the name of a directory 685 * (i.e., ends with '/'), then remove the directory and its contents. 686 * If the removal was successful, return the number of entries 687 * remaining in the directory entry that contained the deleted entry. 688 * If the name was not found, return -1. Please note that this 689 * function only deletes the entry from the cache; it does not delete 690 * it from the filesystem or ensure that other cache entries (which 691 * might be symbolic references to the removed entry) are updated. 692 * Nor does it remove any containing dir entries that might be made 693 * empty by the removal. dir must represent the top-level directory 694 * and must already be complete. 695 */ 696static intremove_entry(struct ref_dir *dir,const char*refname) 697{ 698int refname_len =strlen(refname); 699int entry_index; 700struct ref_entry *entry; 701int is_dir = refname[refname_len -1] =='/'; 702if(is_dir) { 703/* 704 * refname represents a reference directory. Remove 705 * the trailing slash; otherwise we will get the 706 * directory *representing* refname rather than the 707 * one *containing* it. 708 */ 709char*dirname =xmemdupz(refname, refname_len -1); 710 dir =find_containing_dir(dir, dirname,0); 711free(dirname); 712}else{ 713 dir =find_containing_dir(dir, refname,0); 714} 715if(!dir) 716return-1; 717 entry_index =search_ref_dir(dir, refname, refname_len); 718if(entry_index == -1) 719return-1; 720 entry = dir->entries[entry_index]; 721 722memmove(&dir->entries[entry_index], 723&dir->entries[entry_index +1], 724(dir->nr - entry_index -1) *sizeof(*dir->entries) 725); 726 dir->nr--; 727if(dir->sorted > entry_index) 728 dir->sorted--; 729free_ref_entry(entry); 730return dir->nr; 731} 732 733/* 734 * Add a ref_entry to the ref_dir (unsorted), recursing into 735 * subdirectories as necessary. dir must represent the top-level 736 * directory. Return 0 on success. 737 */ 738static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 739{ 740 dir =find_containing_dir(dir, ref->name,1); 741if(!dir) 742return-1; 743add_entry_to_dir(dir, ref); 744return0; 745} 746 747/* 748 * Emit a warning and return true iff ref1 and ref2 have the same name 749 * and the same sha1. Die if they have the same name but different 750 * sha1s. 751 */ 752static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 753{ 754if(strcmp(ref1->name, ref2->name)) 755return0; 756 757/* Duplicate name; make sure that they don't conflict: */ 758 759if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 760/* This is impossible by construction */ 761die("Reference directory conflict:%s", ref1->name); 762 763if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 764die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 765 766warning("Duplicated ref:%s", ref1->name); 767return1; 768} 769 770/* 771 * Sort the entries in dir non-recursively (if they are not already 772 * sorted) and remove any duplicate entries. 773 */ 774static voidsort_ref_dir(struct ref_dir *dir) 775{ 776int i, j; 777struct ref_entry *last = NULL; 778 779/* 780 * This check also prevents passing a zero-length array to qsort(), 781 * which is a problem on some platforms. 782 */ 783if(dir->sorted == dir->nr) 784return; 785 786qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 787 788/* Remove any duplicates: */ 789for(i =0, j =0; j < dir->nr; j++) { 790struct ref_entry *entry = dir->entries[j]; 791if(last &&is_dup_ref(last, entry)) 792free_ref_entry(entry); 793else 794 last = dir->entries[i++] = entry; 795} 796 dir->sorted = dir->nr = i; 797} 798 799/* Include broken references in a do_for_each_ref*() iteration: */ 800#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 801 802/* 803 * Return true iff the reference described by entry can be resolved to 804 * an object in the database. Emit a warning if the referred-to 805 * object does not exist. 806 */ 807static intref_resolves_to_object(struct ref_entry *entry) 808{ 809if(entry->flag & REF_ISBROKEN) 810return0; 811if(!has_sha1_file(entry->u.value.sha1)) { 812error("%sdoes not point to a valid object!", entry->name); 813return0; 814} 815return1; 816} 817 818/* 819 * current_ref is a performance hack: when iterating over references 820 * using the for_each_ref*() functions, current_ref is set to the 821 * current reference's entry before calling the callback function. If 822 * the callback function calls peel_ref(), then peel_ref() first 823 * checks whether the reference to be peeled is the current reference 824 * (it usually is) and if so, returns that reference's peeled version 825 * if it is available. This avoids a refname lookup in a common case. 826 */ 827static struct ref_entry *current_ref; 828 829typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 830 831struct ref_entry_cb { 832const char*base; 833int trim; 834int flags; 835 each_ref_fn *fn; 836void*cb_data; 837}; 838 839/* 840 * Handle one reference in a do_for_each_ref*()-style iteration, 841 * calling an each_ref_fn for each entry. 842 */ 843static intdo_one_ref(struct ref_entry *entry,void*cb_data) 844{ 845struct ref_entry_cb *data = cb_data; 846struct ref_entry *old_current_ref; 847int retval; 848 849if(!starts_with(entry->name, data->base)) 850return0; 851 852if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 853!ref_resolves_to_object(entry)) 854return0; 855 856/* Store the old value, in case this is a recursive call: */ 857 old_current_ref = current_ref; 858 current_ref = entry; 859 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 860 entry->flag, data->cb_data); 861 current_ref = old_current_ref; 862return retval; 863} 864 865/* 866 * Call fn for each reference in dir that has index in the range 867 * offset <= index < dir->nr. Recurse into subdirectories that are in 868 * that index range, sorting them before iterating. This function 869 * does not sort dir itself; it should be sorted beforehand. fn is 870 * called for all references, including broken ones. 871 */ 872static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 873 each_ref_entry_fn fn,void*cb_data) 874{ 875int i; 876assert(dir->sorted == dir->nr); 877for(i = offset; i < dir->nr; i++) { 878struct ref_entry *entry = dir->entries[i]; 879int retval; 880if(entry->flag & REF_DIR) { 881struct ref_dir *subdir =get_ref_dir(entry); 882sort_ref_dir(subdir); 883 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 884}else{ 885 retval =fn(entry, cb_data); 886} 887if(retval) 888return retval; 889} 890return0; 891} 892 893/* 894 * Call fn for each reference in the union of dir1 and dir2, in order 895 * by refname. Recurse into subdirectories. If a value entry appears 896 * in both dir1 and dir2, then only process the version that is in 897 * dir2. The input dirs must already be sorted, but subdirs will be 898 * sorted as needed. fn is called for all references, including 899 * broken ones. 900 */ 901static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 902struct ref_dir *dir2, 903 each_ref_entry_fn fn,void*cb_data) 904{ 905int retval; 906int i1 =0, i2 =0; 907 908assert(dir1->sorted == dir1->nr); 909assert(dir2->sorted == dir2->nr); 910while(1) { 911struct ref_entry *e1, *e2; 912int cmp; 913if(i1 == dir1->nr) { 914returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 915} 916if(i2 == dir2->nr) { 917returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 918} 919 e1 = dir1->entries[i1]; 920 e2 = dir2->entries[i2]; 921 cmp =strcmp(e1->name, e2->name); 922if(cmp ==0) { 923if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 924/* Both are directories; descend them in parallel. */ 925struct ref_dir *subdir1 =get_ref_dir(e1); 926struct ref_dir *subdir2 =get_ref_dir(e2); 927sort_ref_dir(subdir1); 928sort_ref_dir(subdir2); 929 retval =do_for_each_entry_in_dirs( 930 subdir1, subdir2, fn, cb_data); 931 i1++; 932 i2++; 933}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 934/* Both are references; ignore the one from dir1. */ 935 retval =fn(e2, cb_data); 936 i1++; 937 i2++; 938}else{ 939die("conflict between reference and directory:%s", 940 e1->name); 941} 942}else{ 943struct ref_entry *e; 944if(cmp <0) { 945 e = e1; 946 i1++; 947}else{ 948 e = e2; 949 i2++; 950} 951if(e->flag & REF_DIR) { 952struct ref_dir *subdir =get_ref_dir(e); 953sort_ref_dir(subdir); 954 retval =do_for_each_entry_in_dir( 955 subdir,0, fn, cb_data); 956}else{ 957 retval =fn(e, cb_data); 958} 959} 960if(retval) 961return retval; 962} 963} 964 965/* 966 * Load all of the refs from the dir into our in-memory cache. The hard work 967 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 968 * through all of the sub-directories. We do not even need to care about 969 * sorting, as traversal order does not matter to us. 970 */ 971static voidprime_ref_dir(struct ref_dir *dir) 972{ 973int i; 974for(i =0; i < dir->nr; i++) { 975struct ref_entry *entry = dir->entries[i]; 976if(entry->flag & REF_DIR) 977prime_ref_dir(get_ref_dir(entry)); 978} 979} 980/* 981 * Return true iff refname1 and refname2 conflict with each other. 982 * Two reference names conflict if one of them exactly matches the 983 * leading components of the other; e.g., "foo/bar" conflicts with 984 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 985 * "foo/barbados". 986 */ 987static intnames_conflict(const char*refname1,const char*refname2) 988{ 989for(; *refname1 && *refname1 == *refname2; refname1++, refname2++) 990; 991return(*refname1 =='\0'&& *refname2 =='/') 992|| (*refname1 =='/'&& *refname2 =='\0'); 993} 994 995struct name_conflict_cb { 996const char*refname; 997const char*oldrefname; 998const char*conflicting_refname; 999};10001001static intname_conflict_fn(struct ref_entry *entry,void*cb_data)1002{1003struct name_conflict_cb *data = (struct name_conflict_cb *)cb_data;1004if(data->oldrefname && !strcmp(data->oldrefname, entry->name))1005return0;1006if(names_conflict(data->refname, entry->name)) {1007 data->conflicting_refname = entry->name;1008return1;1009}1010return0;1011}10121013/*1014 * Return true iff a reference named refname could be created without1015 * conflicting with the name of an existing reference in dir. If1016 * oldrefname is non-NULL, ignore potential conflicts with oldrefname1017 * (e.g., because oldrefname is scheduled for deletion in the same1018 * operation).1019 */1020static intis_refname_available(const char*refname,const char*oldrefname,1021struct ref_dir *dir)1022{1023struct name_conflict_cb data;1024 data.refname = refname;1025 data.oldrefname = oldrefname;1026 data.conflicting_refname = NULL;10271028sort_ref_dir(dir);1029if(do_for_each_entry_in_dir(dir,0, name_conflict_fn, &data)) {1030error("'%s' exists; cannot create '%s'",1031 data.conflicting_refname, refname);1032return0;1033}1034return1;1035}10361037struct packed_ref_cache {1038struct ref_entry *root;10391040/*1041 * Count of references to the data structure in this instance,1042 * including the pointer from ref_cache::packed if any. The1043 * data will not be freed as long as the reference count is1044 * nonzero.1045 */1046unsigned int referrers;10471048/*1049 * Iff the packed-refs file associated with this instance is1050 * currently locked for writing, this points at the associated1051 * lock (which is owned by somebody else). The referrer count1052 * is also incremented when the file is locked and decremented1053 * when it is unlocked.1054 */1055struct lock_file *lock;10561057/* The metadata from when this packed-refs cache was read */1058struct stat_validity validity;1059};10601061/*1062 * Future: need to be in "struct repository"1063 * when doing a full libification.1064 */1065static struct ref_cache {1066struct ref_cache *next;1067struct ref_entry *loose;1068struct packed_ref_cache *packed;1069/*1070 * The submodule name, or "" for the main repo. We allocate1071 * length 1 rather than FLEX_ARRAY so that the main ref_cache1072 * is initialized correctly.1073 */1074char name[1];1075} ref_cache, *submodule_ref_caches;10761077/* Lock used for the main packed-refs file: */1078static struct lock_file packlock;10791080/*1081 * Increment the reference count of *packed_refs.1082 */1083static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs)1084{1085 packed_refs->referrers++;1086}10871088/*1089 * Decrease the reference count of *packed_refs. If it goes to zero,1090 * free *packed_refs and return true; otherwise return false.1091 */1092static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs)1093{1094if(!--packed_refs->referrers) {1095free_ref_entry(packed_refs->root);1096stat_validity_clear(&packed_refs->validity);1097free(packed_refs);1098return1;1099}else{1100return0;1101}1102}11031104static voidclear_packed_ref_cache(struct ref_cache *refs)1105{1106if(refs->packed) {1107struct packed_ref_cache *packed_refs = refs->packed;11081109if(packed_refs->lock)1110die("internal error: packed-ref cache cleared while locked");1111 refs->packed = NULL;1112release_packed_ref_cache(packed_refs);1113}1114}11151116static voidclear_loose_ref_cache(struct ref_cache *refs)1117{1118if(refs->loose) {1119free_ref_entry(refs->loose);1120 refs->loose = NULL;1121}1122}11231124static struct ref_cache *create_ref_cache(const char*submodule)1125{1126int len;1127struct ref_cache *refs;1128if(!submodule)1129 submodule ="";1130 len =strlen(submodule) +1;1131 refs =xcalloc(1,sizeof(struct ref_cache) + len);1132memcpy(refs->name, submodule, len);1133return refs;1134}11351136/*1137 * Return a pointer to a ref_cache for the specified submodule. For1138 * the main repository, use submodule==NULL. The returned structure1139 * will be allocated and initialized but not necessarily populated; it1140 * should not be freed.1141 */1142static struct ref_cache *get_ref_cache(const char*submodule)1143{1144struct ref_cache *refs;11451146if(!submodule || !*submodule)1147return&ref_cache;11481149for(refs = submodule_ref_caches; refs; refs = refs->next)1150if(!strcmp(submodule, refs->name))1151return refs;11521153 refs =create_ref_cache(submodule);1154 refs->next = submodule_ref_caches;1155 submodule_ref_caches = refs;1156return refs;1157}11581159/* The length of a peeled reference line in packed-refs, including EOL: */1160#define PEELED_LINE_LENGTH 4211611162/*1163 * The packed-refs header line that we write out. Perhaps other1164 * traits will be added later. The trailing space is required.1165 */1166static const char PACKED_REFS_HEADER[] =1167"# pack-refs with: peeled fully-peeled\n";11681169/*1170 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1171 * Return a pointer to the refname within the line (null-terminated),1172 * or NULL if there was a problem.1173 */1174static const char*parse_ref_line(char*line,unsigned char*sha1)1175{1176/*1177 * 42: the answer to everything.1178 *1179 * In this case, it happens to be the answer to1180 * 40 (length of sha1 hex representation)1181 * +1 (space in between hex and name)1182 * +1 (newline at the end of the line)1183 */1184int len =strlen(line) -42;11851186if(len <=0)1187return NULL;1188if(get_sha1_hex(line, sha1) <0)1189return NULL;1190if(!isspace(line[40]))1191return NULL;1192 line +=41;1193if(isspace(*line))1194return NULL;1195if(line[len] !='\n')1196return NULL;1197 line[len] =0;11981199return line;1200}12011202/*1203 * Read f, which is a packed-refs file, into dir.1204 *1205 * A comment line of the form "# pack-refs with: " may contain zero or1206 * more traits. We interpret the traits as follows:1207 *1208 * No traits:1209 *1210 * Probably no references are peeled. But if the file contains a1211 * peeled value for a reference, we will use it.1212 *1213 * peeled:1214 *1215 * References under "refs/tags/", if they *can* be peeled, *are*1216 * peeled in this file. References outside of "refs/tags/" are1217 * probably not peeled even if they could have been, but if we find1218 * a peeled value for such a reference we will use it.1219 *1220 * fully-peeled:1221 *1222 * All references in the file that can be peeled are peeled.1223 * Inversely (and this is more important), any references in the1224 * file for which no peeled value is recorded is not peelable. This1225 * trait should typically be written alongside "peeled" for1226 * compatibility with older clients, but we do not require it1227 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1228 */1229static voidread_packed_refs(FILE*f,struct ref_dir *dir)1230{1231struct ref_entry *last = NULL;1232char refline[PATH_MAX];1233enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;12341235while(fgets(refline,sizeof(refline), f)) {1236unsigned char sha1[20];1237const char*refname;1238static const char header[] ="# pack-refs with:";12391240if(!strncmp(refline, header,sizeof(header)-1)) {1241const char*traits = refline +sizeof(header) -1;1242if(strstr(traits," fully-peeled "))1243 peeled = PEELED_FULLY;1244else if(strstr(traits," peeled "))1245 peeled = PEELED_TAGS;1246/* perhaps other traits later as well */1247continue;1248}12491250 refname =parse_ref_line(refline, sha1);1251if(refname) {1252 last =create_ref_entry(refname, sha1, REF_ISPACKED,1);1253if(peeled == PEELED_FULLY ||1254(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1255 last->flag |= REF_KNOWS_PEELED;1256add_ref(dir, last);1257continue;1258}1259if(last &&1260 refline[0] =='^'&&1261strlen(refline) == PEELED_LINE_LENGTH &&1262 refline[PEELED_LINE_LENGTH -1] =='\n'&&1263!get_sha1_hex(refline +1, sha1)) {1264hashcpy(last->u.value.peeled, sha1);1265/*1266 * Regardless of what the file header said,1267 * we definitely know the value of *this*1268 * reference:1269 */1270 last->flag |= REF_KNOWS_PEELED;1271}1272}1273}12741275/*1276 * Get the packed_ref_cache for the specified ref_cache, creating it1277 * if necessary.1278 */1279static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1280{1281const char*packed_refs_file;12821283if(*refs->name)1284 packed_refs_file =git_path_submodule(refs->name,"packed-refs");1285else1286 packed_refs_file =git_path("packed-refs");12871288if(refs->packed &&1289!stat_validity_check(&refs->packed->validity, packed_refs_file))1290clear_packed_ref_cache(refs);12911292if(!refs->packed) {1293FILE*f;12941295 refs->packed =xcalloc(1,sizeof(*refs->packed));1296acquire_packed_ref_cache(refs->packed);1297 refs->packed->root =create_dir_entry(refs,"",0,0);1298 f =fopen(packed_refs_file,"r");1299if(f) {1300stat_validity_update(&refs->packed->validity,fileno(f));1301read_packed_refs(f,get_ref_dir(refs->packed->root));1302fclose(f);1303}1304}1305return refs->packed;1306}13071308static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1309{1310returnget_ref_dir(packed_ref_cache->root);1311}13121313static struct ref_dir *get_packed_refs(struct ref_cache *refs)1314{1315returnget_packed_ref_dir(get_packed_ref_cache(refs));1316}13171318voidadd_packed_ref(const char*refname,const unsigned char*sha1)1319{1320struct packed_ref_cache *packed_ref_cache =1321get_packed_ref_cache(&ref_cache);13221323if(!packed_ref_cache->lock)1324die("internal error: packed refs not locked");1325add_ref(get_packed_ref_dir(packed_ref_cache),1326create_ref_entry(refname, sha1, REF_ISPACKED,1));1327}13281329/*1330 * Read the loose references from the namespace dirname into dir1331 * (without recursing). dirname must end with '/'. dir must be the1332 * directory entry corresponding to dirname.1333 */1334static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1335{1336struct ref_cache *refs = dir->ref_cache;1337DIR*d;1338const char*path;1339struct dirent *de;1340int dirnamelen =strlen(dirname);1341struct strbuf refname;13421343if(*refs->name)1344 path =git_path_submodule(refs->name,"%s", dirname);1345else1346 path =git_path("%s", dirname);13471348 d =opendir(path);1349if(!d)1350return;13511352strbuf_init(&refname, dirnamelen +257);1353strbuf_add(&refname, dirname, dirnamelen);13541355while((de =readdir(d)) != NULL) {1356unsigned char sha1[20];1357struct stat st;1358int flag;1359const char*refdir;13601361if(de->d_name[0] =='.')1362continue;1363if(has_extension(de->d_name,".lock"))1364continue;1365strbuf_addstr(&refname, de->d_name);1366 refdir = *refs->name1367?git_path_submodule(refs->name,"%s", refname.buf)1368:git_path("%s", refname.buf);1369if(stat(refdir, &st) <0) {1370;/* silently ignore */1371}else if(S_ISDIR(st.st_mode)) {1372strbuf_addch(&refname,'/');1373add_entry_to_dir(dir,1374create_dir_entry(refs, refname.buf,1375 refname.len,1));1376}else{1377if(*refs->name) {1378hashclr(sha1);1379 flag =0;1380if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1381hashclr(sha1);1382 flag |= REF_ISBROKEN;1383}1384}else if(read_ref_full(refname.buf, sha1,1, &flag)) {1385hashclr(sha1);1386 flag |= REF_ISBROKEN;1387}1388add_entry_to_dir(dir,1389create_ref_entry(refname.buf, sha1, flag,1));1390}1391strbuf_setlen(&refname, dirnamelen);1392}1393strbuf_release(&refname);1394closedir(d);1395}13961397static struct ref_dir *get_loose_refs(struct ref_cache *refs)1398{1399if(!refs->loose) {1400/*1401 * Mark the top-level directory complete because we1402 * are about to read the only subdirectory that can1403 * hold references:1404 */1405 refs->loose =create_dir_entry(refs,"",0,0);1406/*1407 * Create an incomplete entry for "refs/":1408 */1409add_entry_to_dir(get_ref_dir(refs->loose),1410create_dir_entry(refs,"refs/",5,1));1411}1412returnget_ref_dir(refs->loose);1413}14141415/* We allow "recursive" symbolic refs. Only within reason, though */1416#define MAXDEPTH 51417#define MAXREFLEN (1024)14181419/*1420 * Called by resolve_gitlink_ref_recursive() after it failed to read1421 * from the loose refs in ref_cache refs. Find <refname> in the1422 * packed-refs file for the submodule.1423 */1424static intresolve_gitlink_packed_ref(struct ref_cache *refs,1425const char*refname,unsigned char*sha1)1426{1427struct ref_entry *ref;1428struct ref_dir *dir =get_packed_refs(refs);14291430 ref =find_ref(dir, refname);1431if(ref == NULL)1432return-1;14331434hashcpy(sha1, ref->u.value.sha1);1435return0;1436}14371438static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1439const char*refname,unsigned char*sha1,1440int recursion)1441{1442int fd, len;1443char buffer[128], *p;1444char*path;14451446if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1447return-1;1448 path = *refs->name1449?git_path_submodule(refs->name,"%s", refname)1450:git_path("%s", refname);1451 fd =open(path, O_RDONLY);1452if(fd <0)1453returnresolve_gitlink_packed_ref(refs, refname, sha1);14541455 len =read(fd, buffer,sizeof(buffer)-1);1456close(fd);1457if(len <0)1458return-1;1459while(len &&isspace(buffer[len-1]))1460 len--;1461 buffer[len] =0;14621463/* Was it a detached head or an old-fashioned symlink? */1464if(!get_sha1_hex(buffer, sha1))1465return0;14661467/* Symref? */1468if(strncmp(buffer,"ref:",4))1469return-1;1470 p = buffer +4;1471while(isspace(*p))1472 p++;14731474returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1475}14761477intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1478{1479int len =strlen(path), retval;1480char*submodule;1481struct ref_cache *refs;14821483while(len && path[len-1] =='/')1484 len--;1485if(!len)1486return-1;1487 submodule =xstrndup(path, len);1488 refs =get_ref_cache(submodule);1489free(submodule);14901491 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1492return retval;1493}14941495/*1496 * Return the ref_entry for the given refname from the packed1497 * references. If it does not exist, return NULL.1498 */1499static struct ref_entry *get_packed_ref(const char*refname)1500{1501returnfind_ref(get_packed_refs(&ref_cache), refname);1502}15031504/*1505 * A loose ref file doesn't exist; check for a packed ref. The1506 * options are forwarded from resolve_safe_unsafe().1507 */1508static const char*handle_missing_loose_ref(const char*refname,1509unsigned char*sha1,1510int reading,1511int*flag)1512{1513struct ref_entry *entry;15141515/*1516 * The loose reference file does not exist; check for a packed1517 * reference.1518 */1519 entry =get_packed_ref(refname);1520if(entry) {1521hashcpy(sha1, entry->u.value.sha1);1522if(flag)1523*flag |= REF_ISPACKED;1524return refname;1525}1526/* The reference is not a packed reference, either. */1527if(reading) {1528return NULL;1529}else{1530hashclr(sha1);1531return refname;1532}1533}15341535const char*resolve_ref_unsafe(const char*refname,unsigned char*sha1,int reading,int*flag)1536{1537int depth = MAXDEPTH;1538 ssize_t len;1539char buffer[256];1540static char refname_buffer[256];15411542if(flag)1543*flag =0;15441545if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))1546return NULL;15471548for(;;) {1549char path[PATH_MAX];1550struct stat st;1551char*buf;1552int fd;15531554if(--depth <0)1555return NULL;15561557git_snpath(path,sizeof(path),"%s", refname);15581559/*1560 * We might have to loop back here to avoid a race1561 * condition: first we lstat() the file, then we try1562 * to read it as a link or as a file. But if somebody1563 * changes the type of the file (file <-> directory1564 * <-> symlink) between the lstat() and reading, then1565 * we don't want to report that as an error but rather1566 * try again starting with the lstat().1567 */1568 stat_ref:1569if(lstat(path, &st) <0) {1570if(errno == ENOENT)1571returnhandle_missing_loose_ref(refname, sha1,1572 reading, flag);1573else1574return NULL;1575}15761577/* Follow "normalized" - ie "refs/.." symlinks by hand */1578if(S_ISLNK(st.st_mode)) {1579 len =readlink(path, buffer,sizeof(buffer)-1);1580if(len <0) {1581if(errno == ENOENT || errno == EINVAL)1582/* inconsistent with lstat; retry */1583goto stat_ref;1584else1585return NULL;1586}1587 buffer[len] =0;1588if(starts_with(buffer,"refs/") &&1589!check_refname_format(buffer,0)) {1590strcpy(refname_buffer, buffer);1591 refname = refname_buffer;1592if(flag)1593*flag |= REF_ISSYMREF;1594continue;1595}1596}15971598/* Is it a directory? */1599if(S_ISDIR(st.st_mode)) {1600 errno = EISDIR;1601return NULL;1602}16031604/*1605 * Anything else, just open it and try to use it as1606 * a ref1607 */1608 fd =open(path, O_RDONLY);1609if(fd <0) {1610if(errno == ENOENT)1611/* inconsistent with lstat; retry */1612goto stat_ref;1613else1614return NULL;1615}1616 len =read_in_full(fd, buffer,sizeof(buffer)-1);1617close(fd);1618if(len <0)1619return NULL;1620while(len &&isspace(buffer[len-1]))1621 len--;1622 buffer[len] ='\0';16231624/*1625 * Is it a symbolic ref?1626 */1627if(!starts_with(buffer,"ref:")) {1628/*1629 * Please note that FETCH_HEAD has a second1630 * line containing other data.1631 */1632if(get_sha1_hex(buffer, sha1) ||1633(buffer[40] !='\0'&& !isspace(buffer[40]))) {1634if(flag)1635*flag |= REF_ISBROKEN;1636return NULL;1637}1638return refname;1639}1640if(flag)1641*flag |= REF_ISSYMREF;1642 buf = buffer +4;1643while(isspace(*buf))1644 buf++;1645if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1646if(flag)1647*flag |= REF_ISBROKEN;1648return NULL;1649}1650 refname =strcpy(refname_buffer, buf);1651}1652}16531654char*resolve_refdup(const char*ref,unsigned char*sha1,int reading,int*flag)1655{1656const char*ret =resolve_ref_unsafe(ref, sha1, reading, flag);1657return ret ?xstrdup(ret) : NULL;1658}16591660/* The argument to filter_refs */1661struct ref_filter {1662const char*pattern;1663 each_ref_fn *fn;1664void*cb_data;1665};16661667intread_ref_full(const char*refname,unsigned char*sha1,int reading,int*flags)1668{1669if(resolve_ref_unsafe(refname, sha1, reading, flags))1670return0;1671return-1;1672}16731674intread_ref(const char*refname,unsigned char*sha1)1675{1676returnread_ref_full(refname, sha1,1, NULL);1677}16781679intref_exists(const char*refname)1680{1681unsigned char sha1[20];1682return!!resolve_ref_unsafe(refname, sha1,1, NULL);1683}16841685static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1686void*data)1687{1688struct ref_filter *filter = (struct ref_filter *)data;1689if(wildmatch(filter->pattern, refname,0, NULL))1690return0;1691return filter->fn(refname, sha1, flags, filter->cb_data);1692}16931694enum peel_status {1695/* object was peeled successfully: */1696 PEEL_PEELED =0,16971698/*1699 * object cannot be peeled because the named object (or an1700 * object referred to by a tag in the peel chain), does not1701 * exist.1702 */1703 PEEL_INVALID = -1,17041705/* object cannot be peeled because it is not a tag: */1706 PEEL_NON_TAG = -2,17071708/* ref_entry contains no peeled value because it is a symref: */1709 PEEL_IS_SYMREF = -3,17101711/*1712 * ref_entry cannot be peeled because it is broken (i.e., the1713 * symbolic reference cannot even be resolved to an object1714 * name):1715 */1716 PEEL_BROKEN = -41717};17181719/*1720 * Peel the named object; i.e., if the object is a tag, resolve the1721 * tag recursively until a non-tag is found. If successful, store the1722 * result to sha1 and return PEEL_PEELED. If the object is not a tag1723 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1724 * and leave sha1 unchanged.1725 */1726static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1727{1728struct object *o =lookup_unknown_object(name);17291730if(o->type == OBJ_NONE) {1731int type =sha1_object_info(name, NULL);1732if(type <0)1733return PEEL_INVALID;1734 o->type = type;1735}17361737if(o->type != OBJ_TAG)1738return PEEL_NON_TAG;17391740 o =deref_tag_noverify(o);1741if(!o)1742return PEEL_INVALID;17431744hashcpy(sha1, o->sha1);1745return PEEL_PEELED;1746}17471748/*1749 * Peel the entry (if possible) and return its new peel_status. If1750 * repeel is true, re-peel the entry even if there is an old peeled1751 * value that is already stored in it.1752 *1753 * It is OK to call this function with a packed reference entry that1754 * might be stale and might even refer to an object that has since1755 * been garbage-collected. In such a case, if the entry has1756 * REF_KNOWS_PEELED then leave the status unchanged and return1757 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1758 */1759static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1760{1761enum peel_status status;17621763if(entry->flag & REF_KNOWS_PEELED) {1764if(repeel) {1765 entry->flag &= ~REF_KNOWS_PEELED;1766hashclr(entry->u.value.peeled);1767}else{1768returnis_null_sha1(entry->u.value.peeled) ?1769 PEEL_NON_TAG : PEEL_PEELED;1770}1771}1772if(entry->flag & REF_ISBROKEN)1773return PEEL_BROKEN;1774if(entry->flag & REF_ISSYMREF)1775return PEEL_IS_SYMREF;17761777 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1778if(status == PEEL_PEELED || status == PEEL_NON_TAG)1779 entry->flag |= REF_KNOWS_PEELED;1780return status;1781}17821783intpeel_ref(const char*refname,unsigned char*sha1)1784{1785int flag;1786unsigned char base[20];17871788if(current_ref && (current_ref->name == refname1789|| !strcmp(current_ref->name, refname))) {1790if(peel_entry(current_ref,0))1791return-1;1792hashcpy(sha1, current_ref->u.value.peeled);1793return0;1794}17951796if(read_ref_full(refname, base,1, &flag))1797return-1;17981799/*1800 * If the reference is packed, read its ref_entry from the1801 * cache in the hope that we already know its peeled value.1802 * We only try this optimization on packed references because1803 * (a) forcing the filling of the loose reference cache could1804 * be expensive and (b) loose references anyway usually do not1805 * have REF_KNOWS_PEELED.1806 */1807if(flag & REF_ISPACKED) {1808struct ref_entry *r =get_packed_ref(refname);1809if(r) {1810if(peel_entry(r,0))1811return-1;1812hashcpy(sha1, r->u.value.peeled);1813return0;1814}1815}18161817returnpeel_object(base, sha1);1818}18191820struct warn_if_dangling_data {1821FILE*fp;1822const char*refname;1823const char*msg_fmt;1824};18251826static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1827int flags,void*cb_data)1828{1829struct warn_if_dangling_data *d = cb_data;1830const char*resolves_to;1831unsigned char junk[20];18321833if(!(flags & REF_ISSYMREF))1834return0;18351836 resolves_to =resolve_ref_unsafe(refname, junk,0, NULL);1837if(!resolves_to ||strcmp(resolves_to, d->refname))1838return0;18391840fprintf(d->fp, d->msg_fmt, refname);1841fputc('\n', d->fp);1842return0;1843}18441845voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1846{1847struct warn_if_dangling_data data;18481849 data.fp = fp;1850 data.refname = refname;1851 data.msg_fmt = msg_fmt;1852for_each_rawref(warn_if_dangling_symref, &data);1853}18541855/*1856 * Call fn for each reference in the specified ref_cache, omitting1857 * references not in the containing_dir of base. fn is called for all1858 * references, including broken ones. If fn ever returns a non-zero1859 * value, stop the iteration and return that value; otherwise, return1860 * 0.1861 */1862static intdo_for_each_entry(struct ref_cache *refs,const char*base,1863 each_ref_entry_fn fn,void*cb_data)1864{1865struct packed_ref_cache *packed_ref_cache;1866struct ref_dir *loose_dir;1867struct ref_dir *packed_dir;1868int retval =0;18691870/*1871 * We must make sure that all loose refs are read before accessing the1872 * packed-refs file; this avoids a race condition in which loose refs1873 * are migrated to the packed-refs file by a simultaneous process, but1874 * our in-memory view is from before the migration. get_packed_ref_cache()1875 * takes care of making sure our view is up to date with what is on1876 * disk.1877 */1878 loose_dir =get_loose_refs(refs);1879if(base && *base) {1880 loose_dir =find_containing_dir(loose_dir, base,0);1881}1882if(loose_dir)1883prime_ref_dir(loose_dir);18841885 packed_ref_cache =get_packed_ref_cache(refs);1886acquire_packed_ref_cache(packed_ref_cache);1887 packed_dir =get_packed_ref_dir(packed_ref_cache);1888if(base && *base) {1889 packed_dir =find_containing_dir(packed_dir, base,0);1890}18911892if(packed_dir && loose_dir) {1893sort_ref_dir(packed_dir);1894sort_ref_dir(loose_dir);1895 retval =do_for_each_entry_in_dirs(1896 packed_dir, loose_dir, fn, cb_data);1897}else if(packed_dir) {1898sort_ref_dir(packed_dir);1899 retval =do_for_each_entry_in_dir(1900 packed_dir,0, fn, cb_data);1901}else if(loose_dir) {1902sort_ref_dir(loose_dir);1903 retval =do_for_each_entry_in_dir(1904 loose_dir,0, fn, cb_data);1905}19061907release_packed_ref_cache(packed_ref_cache);1908return retval;1909}19101911/*1912 * Call fn for each reference in the specified ref_cache for which the1913 * refname begins with base. If trim is non-zero, then trim that many1914 * characters off the beginning of each refname before passing the1915 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1916 * broken references in the iteration. If fn ever returns a non-zero1917 * value, stop the iteration and return that value; otherwise, return1918 * 0.1919 */1920static intdo_for_each_ref(struct ref_cache *refs,const char*base,1921 each_ref_fn fn,int trim,int flags,void*cb_data)1922{1923struct ref_entry_cb data;1924 data.base = base;1925 data.trim = trim;1926 data.flags = flags;1927 data.fn = fn;1928 data.cb_data = cb_data;19291930returndo_for_each_entry(refs, base, do_one_ref, &data);1931}19321933static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1934{1935unsigned char sha1[20];1936int flag;19371938if(submodule) {1939if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1940returnfn("HEAD", sha1,0, cb_data);19411942return0;1943}19441945if(!read_ref_full("HEAD", sha1,1, &flag))1946returnfn("HEAD", sha1, flag, cb_data);19471948return0;1949}19501951inthead_ref(each_ref_fn fn,void*cb_data)1952{1953returndo_head_ref(NULL, fn, cb_data);1954}19551956inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1957{1958returndo_head_ref(submodule, fn, cb_data);1959}19601961intfor_each_ref(each_ref_fn fn,void*cb_data)1962{1963returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1964}19651966intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1967{1968returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1969}19701971intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1972{1973returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);1974}19751976intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1977 each_ref_fn fn,void*cb_data)1978{1979returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);1980}19811982intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1983{1984returnfor_each_ref_in("refs/tags/", fn, cb_data);1985}19861987intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1988{1989returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1990}19911992intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1993{1994returnfor_each_ref_in("refs/heads/", fn, cb_data);1995}19961997intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1998{1999returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);2000}20012002intfor_each_remote_ref(each_ref_fn fn,void*cb_data)2003{2004returnfor_each_ref_in("refs/remotes/", fn, cb_data);2005}20062007intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2008{2009returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);2010}20112012intfor_each_replace_ref(each_ref_fn fn,void*cb_data)2013{2014returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);2015}20162017inthead_ref_namespaced(each_ref_fn fn,void*cb_data)2018{2019struct strbuf buf = STRBUF_INIT;2020int ret =0;2021unsigned char sha1[20];2022int flag;20232024strbuf_addf(&buf,"%sHEAD",get_git_namespace());2025if(!read_ref_full(buf.buf, sha1,1, &flag))2026 ret =fn(buf.buf, sha1, flag, cb_data);2027strbuf_release(&buf);20282029return ret;2030}20312032intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)2033{2034struct strbuf buf = STRBUF_INIT;2035int ret;2036strbuf_addf(&buf,"%srefs/",get_git_namespace());2037 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);2038strbuf_release(&buf);2039return ret;2040}20412042intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,2043const char*prefix,void*cb_data)2044{2045struct strbuf real_pattern = STRBUF_INIT;2046struct ref_filter filter;2047int ret;20482049if(!prefix && !starts_with(pattern,"refs/"))2050strbuf_addstr(&real_pattern,"refs/");2051else if(prefix)2052strbuf_addstr(&real_pattern, prefix);2053strbuf_addstr(&real_pattern, pattern);20542055if(!has_glob_specials(pattern)) {2056/* Append implied '/' '*' if not present. */2057if(real_pattern.buf[real_pattern.len -1] !='/')2058strbuf_addch(&real_pattern,'/');2059/* No need to check for '*', there is none. */2060strbuf_addch(&real_pattern,'*');2061}20622063 filter.pattern = real_pattern.buf;2064 filter.fn = fn;2065 filter.cb_data = cb_data;2066 ret =for_each_ref(filter_refs, &filter);20672068strbuf_release(&real_pattern);2069return ret;2070}20712072intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)2073{2074returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);2075}20762077intfor_each_rawref(each_ref_fn fn,void*cb_data)2078{2079returndo_for_each_ref(&ref_cache,"", fn,0,2080 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2081}20822083const char*prettify_refname(const char*name)2084{2085return name + (2086starts_with(name,"refs/heads/") ?11:2087starts_with(name,"refs/tags/") ?10:2088starts_with(name,"refs/remotes/") ?13:20890);2090}20912092static const char*ref_rev_parse_rules[] = {2093"%.*s",2094"refs/%.*s",2095"refs/tags/%.*s",2096"refs/heads/%.*s",2097"refs/remotes/%.*s",2098"refs/remotes/%.*s/HEAD",2099 NULL2100};21012102intrefname_match(const char*abbrev_name,const char*full_name)2103{2104const char**p;2105const int abbrev_name_len =strlen(abbrev_name);21062107for(p = ref_rev_parse_rules; *p; p++) {2108if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {2109return1;2110}2111}21122113return0;2114}21152116static struct ref_lock *verify_lock(struct ref_lock *lock,2117const unsigned char*old_sha1,int mustexist)2118{2119if(read_ref_full(lock->ref_name, lock->old_sha1, mustexist, NULL)) {2120error("Can't verify ref%s", lock->ref_name);2121unlock_ref(lock);2122return NULL;2123}2124if(hashcmp(lock->old_sha1, old_sha1)) {2125error("Ref%sis at%sbut expected%s", lock->ref_name,2126sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));2127unlock_ref(lock);2128return NULL;2129}2130return lock;2131}21322133static intremove_empty_directories(const char*file)2134{2135/* we want to create a file but there is a directory there;2136 * if that is an empty directory (or a directory that contains2137 * only empty directories), remove them.2138 */2139struct strbuf path;2140int result;21412142strbuf_init(&path,20);2143strbuf_addstr(&path, file);21442145 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);21462147strbuf_release(&path);21482149return result;2150}21512152/*2153 * *string and *len will only be substituted, and *string returned (for2154 * later free()ing) if the string passed in is a magic short-hand form2155 * to name a branch.2156 */2157static char*substitute_branch_name(const char**string,int*len)2158{2159struct strbuf buf = STRBUF_INIT;2160int ret =interpret_branch_name(*string, *len, &buf);21612162if(ret == *len) {2163size_t size;2164*string =strbuf_detach(&buf, &size);2165*len = size;2166return(char*)*string;2167}21682169return NULL;2170}21712172intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)2173{2174char*last_branch =substitute_branch_name(&str, &len);2175const char**p, *r;2176int refs_found =0;21772178*ref = NULL;2179for(p = ref_rev_parse_rules; *p; p++) {2180char fullref[PATH_MAX];2181unsigned char sha1_from_ref[20];2182unsigned char*this_result;2183int flag;21842185 this_result = refs_found ? sha1_from_ref : sha1;2186mksnpath(fullref,sizeof(fullref), *p, len, str);2187 r =resolve_ref_unsafe(fullref, this_result,1, &flag);2188if(r) {2189if(!refs_found++)2190*ref =xstrdup(r);2191if(!warn_ambiguous_refs)2192break;2193}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {2194warning("ignoring dangling symref%s.", fullref);2195}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {2196warning("ignoring broken ref%s.", fullref);2197}2198}2199free(last_branch);2200return refs_found;2201}22022203intdwim_log(const char*str,int len,unsigned char*sha1,char**log)2204{2205char*last_branch =substitute_branch_name(&str, &len);2206const char**p;2207int logs_found =0;22082209*log = NULL;2210for(p = ref_rev_parse_rules; *p; p++) {2211struct stat st;2212unsigned char hash[20];2213char path[PATH_MAX];2214const char*ref, *it;22152216mksnpath(path,sizeof(path), *p, len, str);2217 ref =resolve_ref_unsafe(path, hash,1, NULL);2218if(!ref)2219continue;2220if(!stat(git_path("logs/%s", path), &st) &&2221S_ISREG(st.st_mode))2222 it = path;2223else if(strcmp(ref, path) &&2224!stat(git_path("logs/%s", ref), &st) &&2225S_ISREG(st.st_mode))2226 it = ref;2227else2228continue;2229if(!logs_found++) {2230*log =xstrdup(it);2231hashcpy(sha1, hash);2232}2233if(!warn_ambiguous_refs)2234break;2235}2236free(last_branch);2237return logs_found;2238}22392240static struct ref_lock *lock_ref_sha1_basic(const char*refname,2241const unsigned char*old_sha1,2242int flags,int*type_p)2243{2244char*ref_file;2245const char*orig_refname = refname;2246struct ref_lock *lock;2247int last_errno =0;2248int type, lflags;2249int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2250int missing =0;2251int attempts_remaining =3;22522253 lock =xcalloc(1,sizeof(struct ref_lock));2254 lock->lock_fd = -1;22552256 refname =resolve_ref_unsafe(refname, lock->old_sha1, mustexist, &type);2257if(!refname && errno == EISDIR) {2258/* we are trying to lock foo but we used to2259 * have foo/bar which now does not exist;2260 * it is normal for the empty directory 'foo'2261 * to remain.2262 */2263 ref_file =git_path("%s", orig_refname);2264if(remove_empty_directories(ref_file)) {2265 last_errno = errno;2266error("there are still refs under '%s'", orig_refname);2267goto error_return;2268}2269 refname =resolve_ref_unsafe(orig_refname, lock->old_sha1, mustexist, &type);2270}2271if(type_p)2272*type_p = type;2273if(!refname) {2274 last_errno = errno;2275error("unable to resolve reference%s:%s",2276 orig_refname,strerror(errno));2277goto error_return;2278}2279 missing =is_null_sha1(lock->old_sha1);2280/* When the ref did not exist and we are creating it,2281 * make sure there is no existing ref that is packed2282 * whose name begins with our refname, nor a ref whose2283 * name is a proper prefix of our refname.2284 */2285if(missing &&2286!is_refname_available(refname, NULL,get_packed_refs(&ref_cache))) {2287 last_errno = ENOTDIR;2288goto error_return;2289}22902291 lock->lk =xcalloc(1,sizeof(struct lock_file));22922293 lflags =0;2294if(flags & REF_NODEREF) {2295 refname = orig_refname;2296 lflags |= LOCK_NODEREF;2297}2298 lock->ref_name =xstrdup(refname);2299 lock->orig_ref_name =xstrdup(orig_refname);2300 ref_file =git_path("%s", refname);2301if(missing)2302 lock->force_write =1;2303if((flags & REF_NODEREF) && (type & REF_ISSYMREF))2304 lock->force_write =1;23052306 retry:2307switch(safe_create_leading_directories(ref_file)) {2308case SCLD_OK:2309break;/* success */2310case SCLD_VANISHED:2311if(--attempts_remaining >0)2312goto retry;2313/* fall through */2314default:2315 last_errno = errno;2316error("unable to create directory for%s", ref_file);2317goto error_return;2318}23192320 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);2321if(lock->lock_fd <0) {2322if(errno == ENOENT && --attempts_remaining >0)2323/*2324 * Maybe somebody just deleted one of the2325 * directories leading to ref_file. Try2326 * again:2327 */2328goto retry;2329else2330unable_to_lock_index_die(ref_file, errno);2331}2332return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;23332334 error_return:2335unlock_ref(lock);2336 errno = last_errno;2337return NULL;2338}23392340struct ref_lock *lock_ref_sha1(const char*refname,const unsigned char*old_sha1)2341{2342char refpath[PATH_MAX];2343if(check_refname_format(refname,0))2344return NULL;2345strcpy(refpath,mkpath("refs/%s", refname));2346returnlock_ref_sha1_basic(refpath, old_sha1,0, NULL);2347}23482349struct ref_lock *lock_any_ref_for_update(const char*refname,2350const unsigned char*old_sha1,2351int flags,int*type_p)2352{2353if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL))2354return NULL;2355returnlock_ref_sha1_basic(refname, old_sha1, flags, type_p);2356}23572358/*2359 * Write an entry to the packed-refs file for the specified refname.2360 * If peeled is non-NULL, write it as the entry's peeled value.2361 */2362static voidwrite_packed_entry(int fd,char*refname,unsigned char*sha1,2363unsigned char*peeled)2364{2365char line[PATH_MAX +100];2366int len;23672368 len =snprintf(line,sizeof(line),"%s %s\n",2369sha1_to_hex(sha1), refname);2370/* this should not happen but just being defensive */2371if(len >sizeof(line))2372die("too long a refname '%s'", refname);2373write_or_die(fd, line, len);23742375if(peeled) {2376if(snprintf(line,sizeof(line),"^%s\n",2377sha1_to_hex(peeled)) != PEELED_LINE_LENGTH)2378die("internal error");2379write_or_die(fd, line, PEELED_LINE_LENGTH);2380}2381}23822383/*2384 * An each_ref_entry_fn that writes the entry to a packed-refs file.2385 */2386static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2387{2388int*fd = cb_data;2389enum peel_status peel_status =peel_entry(entry,0);23902391if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2392error("internal error:%sis not a valid packed reference!",2393 entry->name);2394write_packed_entry(*fd, entry->name, entry->u.value.sha1,2395 peel_status == PEEL_PEELED ?2396 entry->u.value.peeled : NULL);2397return0;2398}23992400intlock_packed_refs(int flags)2401{2402struct packed_ref_cache *packed_ref_cache;24032404if(hold_lock_file_for_update(&packlock,git_path("packed-refs"), flags) <0)2405return-1;2406/*2407 * Get the current packed-refs while holding the lock. If the2408 * packed-refs file has been modified since we last read it,2409 * this will automatically invalidate the cache and re-read2410 * the packed-refs file.2411 */2412 packed_ref_cache =get_packed_ref_cache(&ref_cache);2413 packed_ref_cache->lock = &packlock;2414/* Increment the reference count to prevent it from being freed: */2415acquire_packed_ref_cache(packed_ref_cache);2416return0;2417}24182419intcommit_packed_refs(void)2420{2421struct packed_ref_cache *packed_ref_cache =2422get_packed_ref_cache(&ref_cache);2423int error =0;24242425if(!packed_ref_cache->lock)2426die("internal error: packed-refs not locked");2427write_or_die(packed_ref_cache->lock->fd,2428 PACKED_REFS_HEADER,strlen(PACKED_REFS_HEADER));24292430do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),24310, write_packed_entry_fn,2432&packed_ref_cache->lock->fd);2433if(commit_lock_file(packed_ref_cache->lock))2434 error = -1;2435 packed_ref_cache->lock = NULL;2436release_packed_ref_cache(packed_ref_cache);2437return error;2438}24392440voidrollback_packed_refs(void)2441{2442struct packed_ref_cache *packed_ref_cache =2443get_packed_ref_cache(&ref_cache);24442445if(!packed_ref_cache->lock)2446die("internal error: packed-refs not locked");2447rollback_lock_file(packed_ref_cache->lock);2448 packed_ref_cache->lock = NULL;2449release_packed_ref_cache(packed_ref_cache);2450clear_packed_ref_cache(&ref_cache);2451}24522453struct ref_to_prune {2454struct ref_to_prune *next;2455unsigned char sha1[20];2456char name[FLEX_ARRAY];2457};24582459struct pack_refs_cb_data {2460unsigned int flags;2461struct ref_dir *packed_refs;2462struct ref_to_prune *ref_to_prune;2463};24642465/*2466 * An each_ref_entry_fn that is run over loose references only. If2467 * the loose reference can be packed, add an entry in the packed ref2468 * cache. If the reference should be pruned, also add it to2469 * ref_to_prune in the pack_refs_cb_data.2470 */2471static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2472{2473struct pack_refs_cb_data *cb = cb_data;2474enum peel_status peel_status;2475struct ref_entry *packed_entry;2476int is_tag_ref =starts_with(entry->name,"refs/tags/");24772478/* ALWAYS pack tags */2479if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2480return0;24812482/* Do not pack symbolic or broken refs: */2483if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2484return0;24852486/* Add a packed ref cache entry equivalent to the loose entry. */2487 peel_status =peel_entry(entry,1);2488if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2489die("internal error peeling reference%s(%s)",2490 entry->name,sha1_to_hex(entry->u.value.sha1));2491 packed_entry =find_ref(cb->packed_refs, entry->name);2492if(packed_entry) {2493/* Overwrite existing packed entry with info from loose entry */2494 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2495hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2496}else{2497 packed_entry =create_ref_entry(entry->name, entry->u.value.sha1,2498 REF_ISPACKED | REF_KNOWS_PEELED,0);2499add_ref(cb->packed_refs, packed_entry);2500}2501hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);25022503/* Schedule the loose reference for pruning if requested. */2504if((cb->flags & PACK_REFS_PRUNE)) {2505int namelen =strlen(entry->name) +1;2506struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2507hashcpy(n->sha1, entry->u.value.sha1);2508strcpy(n->name, entry->name);2509 n->next = cb->ref_to_prune;2510 cb->ref_to_prune = n;2511}2512return0;2513}25142515/*2516 * Remove empty parents, but spare refs/ and immediate subdirs.2517 * Note: munges *name.2518 */2519static voidtry_remove_empty_parents(char*name)2520{2521char*p, *q;2522int i;2523 p = name;2524for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2525while(*p && *p !='/')2526 p++;2527/* tolerate duplicate slashes; see check_refname_format() */2528while(*p =='/')2529 p++;2530}2531for(q = p; *q; q++)2532;2533while(1) {2534while(q > p && *q !='/')2535 q--;2536while(q > p && *(q-1) =='/')2537 q--;2538if(q == p)2539break;2540*q ='\0';2541if(rmdir(git_path("%s", name)))2542break;2543}2544}25452546/* make sure nobody touched the ref, and unlink */2547static voidprune_ref(struct ref_to_prune *r)2548{2549struct ref_lock *lock =lock_ref_sha1(r->name +5, r->sha1);25502551if(lock) {2552unlink_or_warn(git_path("%s", r->name));2553unlock_ref(lock);2554try_remove_empty_parents(r->name);2555}2556}25572558static voidprune_refs(struct ref_to_prune *r)2559{2560while(r) {2561prune_ref(r);2562 r = r->next;2563}2564}25652566intpack_refs(unsigned int flags)2567{2568struct pack_refs_cb_data cbdata;25692570memset(&cbdata,0,sizeof(cbdata));2571 cbdata.flags = flags;25722573lock_packed_refs(LOCK_DIE_ON_ERROR);2574 cbdata.packed_refs =get_packed_refs(&ref_cache);25752576do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2577 pack_if_possible_fn, &cbdata);25782579if(commit_packed_refs())2580die_errno("unable to overwrite old ref-pack file");25812582prune_refs(cbdata.ref_to_prune);2583return0;2584}25852586/*2587 * If entry is no longer needed in packed-refs, add it to the string2588 * list pointed to by cb_data. Reasons for deleting entries:2589 *2590 * - Entry is broken.2591 * - Entry is overridden by a loose ref.2592 * - Entry does not point at a valid object.2593 *2594 * In the first and third cases, also emit an error message because these2595 * are indications of repository corruption.2596 */2597static intcurate_packed_ref_fn(struct ref_entry *entry,void*cb_data)2598{2599struct string_list *refs_to_delete = cb_data;26002601if(entry->flag & REF_ISBROKEN) {2602/* This shouldn't happen to packed refs. */2603error("%sis broken!", entry->name);2604string_list_append(refs_to_delete, entry->name);2605return0;2606}2607if(!has_sha1_file(entry->u.value.sha1)) {2608unsigned char sha1[20];2609int flags;26102611if(read_ref_full(entry->name, sha1,0, &flags))2612/* We should at least have found the packed ref. */2613die("Internal error");2614if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2615/*2616 * This packed reference is overridden by a2617 * loose reference, so it is OK that its value2618 * is no longer valid; for example, it might2619 * refer to an object that has been garbage2620 * collected. For this purpose we don't even2621 * care whether the loose reference itself is2622 * invalid, broken, symbolic, etc. Silently2623 * remove the packed reference.2624 */2625string_list_append(refs_to_delete, entry->name);2626return0;2627}2628/*2629 * There is no overriding loose reference, so the fact2630 * that this reference doesn't refer to a valid object2631 * indicates some kind of repository corruption.2632 * Report the problem, then omit the reference from2633 * the output.2634 */2635error("%sdoes not point to a valid object!", entry->name);2636string_list_append(refs_to_delete, entry->name);2637return0;2638}26392640return0;2641}26422643static intrepack_without_refs(const char**refnames,int n)2644{2645struct ref_dir *packed;2646struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2647struct string_list_item *ref_to_delete;2648int i, removed =0;26492650/* Look for a packed ref */2651for(i =0; i < n; i++)2652if(get_packed_ref(refnames[i]))2653break;26542655/* Avoid locking if we have nothing to do */2656if(i == n)2657return0;/* no refname exists in packed refs */26582659if(lock_packed_refs(0)) {2660unable_to_lock_error(git_path("packed-refs"), errno);2661returnerror("cannot delete '%s' from packed refs", refnames[i]);2662}2663 packed =get_packed_refs(&ref_cache);26642665/* Remove refnames from the cache */2666for(i =0; i < n; i++)2667if(remove_entry(packed, refnames[i]) != -1)2668 removed =1;2669if(!removed) {2670/*2671 * All packed entries disappeared while we were2672 * acquiring the lock.2673 */2674rollback_packed_refs();2675return0;2676}26772678/* Remove any other accumulated cruft */2679do_for_each_entry_in_dir(packed,0, curate_packed_ref_fn, &refs_to_delete);2680for_each_string_list_item(ref_to_delete, &refs_to_delete) {2681if(remove_entry(packed, ref_to_delete->string) == -1)2682die("internal error");2683}26842685/* Write what remains */2686returncommit_packed_refs();2687}26882689static intrepack_without_ref(const char*refname)2690{2691returnrepack_without_refs(&refname,1);2692}26932694static intdelete_ref_loose(struct ref_lock *lock,int flag)2695{2696if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2697/* loose */2698int err, i =strlen(lock->lk->filename) -5;/* .lock */26992700 lock->lk->filename[i] =0;2701 err =unlink_or_warn(lock->lk->filename);2702 lock->lk->filename[i] ='.';2703if(err && errno != ENOENT)2704return1;2705}2706return0;2707}27082709intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2710{2711struct ref_lock *lock;2712int ret =0, flag =0;27132714 lock =lock_ref_sha1_basic(refname, sha1, delopt, &flag);2715if(!lock)2716return1;2717 ret |=delete_ref_loose(lock, flag);27182719/* removing the loose one could have resurrected an earlier2720 * packed one. Also, if it was not loose we need to repack2721 * without it.2722 */2723 ret |=repack_without_ref(lock->ref_name);27242725unlink_or_warn(git_path("logs/%s", lock->ref_name));2726clear_loose_ref_cache(&ref_cache);2727unlock_ref(lock);2728return ret;2729}27302731/*2732 * People using contrib's git-new-workdir have .git/logs/refs ->2733 * /some/other/path/.git/logs/refs, and that may live on another device.2734 *2735 * IOW, to avoid cross device rename errors, the temporary renamed log must2736 * live into logs/refs.2737 */2738#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"27392740static intrename_tmp_log(const char*newrefname)2741{2742int attempts_remaining =4;27432744 retry:2745switch(safe_create_leading_directories(git_path("logs/%s", newrefname))) {2746case SCLD_OK:2747break;/* success */2748case SCLD_VANISHED:2749if(--attempts_remaining >0)2750goto retry;2751/* fall through */2752default:2753error("unable to create directory for%s", newrefname);2754return-1;2755}27562757if(rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2758if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2759/*2760 * rename(a, b) when b is an existing2761 * directory ought to result in ISDIR, but2762 * Solaris 5.8 gives ENOTDIR. Sheesh.2763 */2764if(remove_empty_directories(git_path("logs/%s", newrefname))) {2765error("Directory not empty: logs/%s", newrefname);2766return-1;2767}2768goto retry;2769}else if(errno == ENOENT && --attempts_remaining >0) {2770/*2771 * Maybe another process just deleted one of2772 * the directories in the path to newrefname.2773 * Try again from the beginning.2774 */2775goto retry;2776}else{2777error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2778 newrefname,strerror(errno));2779return-1;2780}2781}2782return0;2783}27842785intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2786{2787unsigned char sha1[20], orig_sha1[20];2788int flag =0, logmoved =0;2789struct ref_lock *lock;2790struct stat loginfo;2791int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2792const char*symref = NULL;27932794if(log &&S_ISLNK(loginfo.st_mode))2795returnerror("reflog for%sis a symlink", oldrefname);27962797 symref =resolve_ref_unsafe(oldrefname, orig_sha1,1, &flag);2798if(flag & REF_ISSYMREF)2799returnerror("refname%sis a symbolic ref, renaming it is not supported",2800 oldrefname);2801if(!symref)2802returnerror("refname%snot found", oldrefname);28032804if(!is_refname_available(newrefname, oldrefname,get_packed_refs(&ref_cache)))2805return1;28062807if(!is_refname_available(newrefname, oldrefname,get_loose_refs(&ref_cache)))2808return1;28092810if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2811returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2812 oldrefname,strerror(errno));28132814if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2815error("unable to delete old%s", oldrefname);2816goto rollback;2817}28182819if(!read_ref_full(newrefname, sha1,1, &flag) &&2820delete_ref(newrefname, sha1, REF_NODEREF)) {2821if(errno==EISDIR) {2822if(remove_empty_directories(git_path("%s", newrefname))) {2823error("Directory not empty:%s", newrefname);2824goto rollback;2825}2826}else{2827error("unable to delete existing%s", newrefname);2828goto rollback;2829}2830}28312832if(log &&rename_tmp_log(newrefname))2833goto rollback;28342835 logmoved = log;28362837 lock =lock_ref_sha1_basic(newrefname, NULL,0, NULL);2838if(!lock) {2839error("unable to lock%sfor update", newrefname);2840goto rollback;2841}2842 lock->force_write =1;2843hashcpy(lock->old_sha1, orig_sha1);2844if(write_ref_sha1(lock, orig_sha1, logmsg)) {2845error("unable to write current sha1 into%s", newrefname);2846goto rollback;2847}28482849return0;28502851 rollback:2852 lock =lock_ref_sha1_basic(oldrefname, NULL,0, NULL);2853if(!lock) {2854error("unable to lock%sfor rollback", oldrefname);2855goto rollbacklog;2856}28572858 lock->force_write =1;2859 flag = log_all_ref_updates;2860 log_all_ref_updates =0;2861if(write_ref_sha1(lock, orig_sha1, NULL))2862error("unable to write current sha1 into%s", oldrefname);2863 log_all_ref_updates = flag;28642865 rollbacklog:2866if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2867error("unable to restore logfile%sfrom%s:%s",2868 oldrefname, newrefname,strerror(errno));2869if(!logmoved && log &&2870rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2871error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2872 oldrefname,strerror(errno));28732874return1;2875}28762877intclose_ref(struct ref_lock *lock)2878{2879if(close_lock_file(lock->lk))2880return-1;2881 lock->lock_fd = -1;2882return0;2883}28842885intcommit_ref(struct ref_lock *lock)2886{2887if(commit_lock_file(lock->lk))2888return-1;2889 lock->lock_fd = -1;2890return0;2891}28922893voidunlock_ref(struct ref_lock *lock)2894{2895/* Do not free lock->lk -- atexit() still looks at them */2896if(lock->lk)2897rollback_lock_file(lock->lk);2898free(lock->ref_name);2899free(lock->orig_ref_name);2900free(lock);2901}29022903/*2904 * copy the reflog message msg to buf, which has been allocated sufficiently2905 * large, while cleaning up the whitespaces. Especially, convert LF to space,2906 * because reflog file is one line per entry.2907 */2908static intcopy_msg(char*buf,const char*msg)2909{2910char*cp = buf;2911char c;2912int wasspace =1;29132914*cp++ ='\t';2915while((c = *msg++)) {2916if(wasspace &&isspace(c))2917continue;2918 wasspace =isspace(c);2919if(wasspace)2920 c =' ';2921*cp++ = c;2922}2923while(buf < cp &&isspace(cp[-1]))2924 cp--;2925*cp++ ='\n';2926return cp - buf;2927}29282929intlog_ref_setup(const char*refname,char*logfile,int bufsize)2930{2931int logfd, oflags = O_APPEND | O_WRONLY;29322933git_snpath(logfile, bufsize,"logs/%s", refname);2934if(log_all_ref_updates &&2935(starts_with(refname,"refs/heads/") ||2936starts_with(refname,"refs/remotes/") ||2937starts_with(refname,"refs/notes/") ||2938!strcmp(refname,"HEAD"))) {2939if(safe_create_leading_directories(logfile) <0)2940returnerror("unable to create directory for%s",2941 logfile);2942 oflags |= O_CREAT;2943}29442945 logfd =open(logfile, oflags,0666);2946if(logfd <0) {2947if(!(oflags & O_CREAT) && errno == ENOENT)2948return0;29492950if((oflags & O_CREAT) && errno == EISDIR) {2951if(remove_empty_directories(logfile)) {2952returnerror("There are still logs under '%s'",2953 logfile);2954}2955 logfd =open(logfile, oflags,0666);2956}29572958if(logfd <0)2959returnerror("Unable to append to%s:%s",2960 logfile,strerror(errno));2961}29622963adjust_shared_perm(logfile);2964close(logfd);2965return0;2966}29672968static intlog_ref_write(const char*refname,const unsigned char*old_sha1,2969const unsigned char*new_sha1,const char*msg)2970{2971int logfd, result, written, oflags = O_APPEND | O_WRONLY;2972unsigned maxlen, len;2973int msglen;2974char log_file[PATH_MAX];2975char*logrec;2976const char*committer;29772978if(log_all_ref_updates <0)2979 log_all_ref_updates = !is_bare_repository();29802981 result =log_ref_setup(refname, log_file,sizeof(log_file));2982if(result)2983return result;29842985 logfd =open(log_file, oflags);2986if(logfd <0)2987return0;2988 msglen = msg ?strlen(msg) :0;2989 committer =git_committer_info(0);2990 maxlen =strlen(committer) + msglen +100;2991 logrec =xmalloc(maxlen);2992 len =sprintf(logrec,"%s %s %s\n",2993sha1_to_hex(old_sha1),2994sha1_to_hex(new_sha1),2995 committer);2996if(msglen)2997 len +=copy_msg(logrec + len -1, msg) -1;2998 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;2999free(logrec);3000if(close(logfd) !=0|| written != len)3001returnerror("Unable to append to%s", log_file);3002return0;3003}30043005static intis_branch(const char*refname)3006{3007return!strcmp(refname,"HEAD") ||starts_with(refname,"refs/heads/");3008}30093010intwrite_ref_sha1(struct ref_lock *lock,3011const unsigned char*sha1,const char*logmsg)3012{3013static char term ='\n';3014struct object *o;30153016if(!lock)3017return-1;3018if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {3019unlock_ref(lock);3020return0;3021}3022 o =parse_object(sha1);3023if(!o) {3024error("Trying to write ref%swith nonexistent object%s",3025 lock->ref_name,sha1_to_hex(sha1));3026unlock_ref(lock);3027return-1;3028}3029if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {3030error("Trying to write non-commit object%sto branch%s",3031sha1_to_hex(sha1), lock->ref_name);3032unlock_ref(lock);3033return-1;3034}3035if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||3036write_in_full(lock->lock_fd, &term,1) !=13037||close_ref(lock) <0) {3038error("Couldn't write%s", lock->lk->filename);3039unlock_ref(lock);3040return-1;3041}3042clear_loose_ref_cache(&ref_cache);3043if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||3044(strcmp(lock->ref_name, lock->orig_ref_name) &&3045log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {3046unlock_ref(lock);3047return-1;3048}3049if(strcmp(lock->orig_ref_name,"HEAD") !=0) {3050/*3051 * Special hack: If a branch is updated directly and HEAD3052 * points to it (may happen on the remote side of a push3053 * for example) then logically the HEAD reflog should be3054 * updated too.3055 * A generic solution implies reverse symref information,3056 * but finding all symrefs pointing to the given branch3057 * would be rather costly for this rare event (the direct3058 * update of a branch) to be worth it. So let's cheat and3059 * check with HEAD only which should cover 99% of all usage3060 * scenarios (even 100% of the default ones).3061 */3062unsigned char head_sha1[20];3063int head_flag;3064const char*head_ref;3065 head_ref =resolve_ref_unsafe("HEAD", head_sha1,1, &head_flag);3066if(head_ref && (head_flag & REF_ISSYMREF) &&3067!strcmp(head_ref, lock->ref_name))3068log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3069}3070if(commit_ref(lock)) {3071error("Couldn't set%s", lock->ref_name);3072unlock_ref(lock);3073return-1;3074}3075unlock_ref(lock);3076return0;3077}30783079intcreate_symref(const char*ref_target,const char*refs_heads_master,3080const char*logmsg)3081{3082const char*lockpath;3083char ref[1000];3084int fd, len, written;3085char*git_HEAD =git_pathdup("%s", ref_target);3086unsigned char old_sha1[20], new_sha1[20];30873088if(logmsg &&read_ref(ref_target, old_sha1))3089hashclr(old_sha1);30903091if(safe_create_leading_directories(git_HEAD) <0)3092returnerror("unable to create directory for%s", git_HEAD);30933094#ifndef NO_SYMLINK_HEAD3095if(prefer_symlink_refs) {3096unlink(git_HEAD);3097if(!symlink(refs_heads_master, git_HEAD))3098goto done;3099fprintf(stderr,"no symlink - falling back to symbolic ref\n");3100}3101#endif31023103 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);3104if(sizeof(ref) <= len) {3105error("refname too long:%s", refs_heads_master);3106goto error_free_return;3107}3108 lockpath =mkpath("%s.lock", git_HEAD);3109 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);3110if(fd <0) {3111error("Unable to open%sfor writing", lockpath);3112goto error_free_return;3113}3114 written =write_in_full(fd, ref, len);3115if(close(fd) !=0|| written != len) {3116error("Unable to write to%s", lockpath);3117goto error_unlink_return;3118}3119if(rename(lockpath, git_HEAD) <0) {3120error("Unable to create%s", git_HEAD);3121goto error_unlink_return;3122}3123if(adjust_shared_perm(git_HEAD)) {3124error("Unable to fix permissions on%s", lockpath);3125 error_unlink_return:3126unlink_or_warn(lockpath);3127 error_free_return:3128free(git_HEAD);3129return-1;3130}31313132#ifndef NO_SYMLINK_HEAD3133 done:3134#endif3135if(logmsg && !read_ref(refs_heads_master, new_sha1))3136log_ref_write(ref_target, old_sha1, new_sha1, logmsg);31373138free(git_HEAD);3139return0;3140}31413142static char*ref_msg(const char*line,const char*endp)3143{3144const char*ep;3145 line +=82;3146 ep =memchr(line,'\n', endp - line);3147if(!ep)3148 ep = endp;3149returnxmemdupz(line, ep - line);3150}31513152intread_ref_at(const char*refname,unsigned long at_time,int cnt,3153unsigned char*sha1,char**msg,3154unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)3155{3156const char*logfile, *logdata, *logend, *rec, *lastgt, *lastrec;3157char*tz_c;3158int logfd, tz, reccnt =0;3159struct stat st;3160unsigned long date;3161unsigned char logged_sha1[20];3162void*log_mapped;3163size_t mapsz;31643165 logfile =git_path("logs/%s", refname);3166 logfd =open(logfile, O_RDONLY,0);3167if(logfd <0)3168die_errno("Unable to read log '%s'", logfile);3169fstat(logfd, &st);3170if(!st.st_size)3171die("Log%sis empty.", logfile);3172 mapsz =xsize_t(st.st_size);3173 log_mapped =xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd,0);3174 logdata = log_mapped;3175close(logfd);31763177 lastrec = NULL;3178 rec = logend = logdata + st.st_size;3179while(logdata < rec) {3180 reccnt++;3181if(logdata < rec && *(rec-1) =='\n')3182 rec--;3183 lastgt = NULL;3184while(logdata < rec && *(rec-1) !='\n') {3185 rec--;3186if(*rec =='>')3187 lastgt = rec;3188}3189if(!lastgt)3190die("Log%sis corrupt.", logfile);3191 date =strtoul(lastgt +1, &tz_c,10);3192if(date <= at_time || cnt ==0) {3193 tz =strtoul(tz_c, NULL,10);3194if(msg)3195*msg =ref_msg(rec, logend);3196if(cutoff_time)3197*cutoff_time = date;3198if(cutoff_tz)3199*cutoff_tz = tz;3200if(cutoff_cnt)3201*cutoff_cnt = reccnt -1;3202if(lastrec) {3203if(get_sha1_hex(lastrec, logged_sha1))3204die("Log%sis corrupt.", logfile);3205if(get_sha1_hex(rec +41, sha1))3206die("Log%sis corrupt.", logfile);3207if(hashcmp(logged_sha1, sha1)) {3208warning("Log%shas gap after%s.",3209 logfile,show_date(date, tz, DATE_RFC2822));3210}3211}3212else if(date == at_time) {3213if(get_sha1_hex(rec +41, sha1))3214die("Log%sis corrupt.", logfile);3215}3216else{3217if(get_sha1_hex(rec +41, logged_sha1))3218die("Log%sis corrupt.", logfile);3219if(hashcmp(logged_sha1, sha1)) {3220warning("Log%sunexpectedly ended on%s.",3221 logfile,show_date(date, tz, DATE_RFC2822));3222}3223}3224munmap(log_mapped, mapsz);3225return0;3226}3227 lastrec = rec;3228if(cnt >0)3229 cnt--;3230}32313232 rec = logdata;3233while(rec < logend && *rec !='>'&& *rec !='\n')3234 rec++;3235if(rec == logend || *rec =='\n')3236die("Log%sis corrupt.", logfile);3237 date =strtoul(rec +1, &tz_c,10);3238 tz =strtoul(tz_c, NULL,10);3239if(get_sha1_hex(logdata, sha1))3240die("Log%sis corrupt.", logfile);3241if(is_null_sha1(sha1)) {3242if(get_sha1_hex(logdata +41, sha1))3243die("Log%sis corrupt.", logfile);3244}3245if(msg)3246*msg =ref_msg(logdata, logend);3247munmap(log_mapped, mapsz);32483249if(cutoff_time)3250*cutoff_time = date;3251if(cutoff_tz)3252*cutoff_tz = tz;3253if(cutoff_cnt)3254*cutoff_cnt = reccnt;3255return1;3256}32573258static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3259{3260unsigned char osha1[20], nsha1[20];3261char*email_end, *message;3262unsigned long timestamp;3263int tz;32643265/* old SP new SP name <email> SP time TAB msg LF */3266if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3267get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3268get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3269!(email_end =strchr(sb->buf +82,'>')) ||3270 email_end[1] !=' '||3271!(timestamp =strtoul(email_end +2, &message,10)) ||3272!message || message[0] !=' '||3273(message[1] !='+'&& message[1] !='-') ||3274!isdigit(message[2]) || !isdigit(message[3]) ||3275!isdigit(message[4]) || !isdigit(message[5]))3276return0;/* corrupt? */3277 email_end[1] ='\0';3278 tz =strtol(message +1, NULL,10);3279if(message[6] !='\t')3280 message +=6;3281else3282 message +=7;3283returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3284}32853286static char*find_beginning_of_line(char*bob,char*scan)3287{3288while(bob < scan && *(--scan) !='\n')3289;/* keep scanning backwards */3290/*3291 * Return either beginning of the buffer, or LF at the end of3292 * the previous line.3293 */3294return scan;3295}32963297intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3298{3299struct strbuf sb = STRBUF_INIT;3300FILE*logfp;3301long pos;3302int ret =0, at_tail =1;33033304 logfp =fopen(git_path("logs/%s", refname),"r");3305if(!logfp)3306return-1;33073308/* Jump to the end */3309if(fseek(logfp,0, SEEK_END) <0)3310returnerror("cannot seek back reflog for%s:%s",3311 refname,strerror(errno));3312 pos =ftell(logfp);3313while(!ret &&0< pos) {3314int cnt;3315size_t nread;3316char buf[BUFSIZ];3317char*endp, *scanp;33183319/* Fill next block from the end */3320 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3321if(fseek(logfp, pos - cnt, SEEK_SET))3322returnerror("cannot seek back reflog for%s:%s",3323 refname,strerror(errno));3324 nread =fread(buf, cnt,1, logfp);3325if(nread !=1)3326returnerror("cannot read%dbytes from reflog for%s:%s",3327 cnt, refname,strerror(errno));3328 pos -= cnt;33293330 scanp = endp = buf + cnt;3331if(at_tail && scanp[-1] =='\n')3332/* Looking at the final LF at the end of the file */3333 scanp--;3334 at_tail =0;33353336while(buf < scanp) {3337/*3338 * terminating LF of the previous line, or the beginning3339 * of the buffer.3340 */3341char*bp;33423343 bp =find_beginning_of_line(buf, scanp);33443345if(*bp !='\n') {3346strbuf_splice(&sb,0,0, buf, endp - buf);3347if(pos)3348break;/* need to fill another block */3349 scanp = buf -1;/* leave loop */3350}else{3351/*3352 * (bp + 1) thru endp is the beginning of the3353 * current line we have in sb3354 */3355strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3356 scanp = bp;3357 endp = bp +1;3358}3359 ret =show_one_reflog_ent(&sb, fn, cb_data);3360strbuf_reset(&sb);3361if(ret)3362break;3363}33643365}3366if(!ret && sb.len)3367 ret =show_one_reflog_ent(&sb, fn, cb_data);33683369fclose(logfp);3370strbuf_release(&sb);3371return ret;3372}33733374intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3375{3376FILE*logfp;3377struct strbuf sb = STRBUF_INIT;3378int ret =0;33793380 logfp =fopen(git_path("logs/%s", refname),"r");3381if(!logfp)3382return-1;33833384while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3385 ret =show_one_reflog_ent(&sb, fn, cb_data);3386fclose(logfp);3387strbuf_release(&sb);3388return ret;3389}3390/*3391 * Call fn for each reflog in the namespace indicated by name. name3392 * must be empty or end with '/'. Name will be used as a scratch3393 * space, but its contents will be restored before return.3394 */3395static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3396{3397DIR*d =opendir(git_path("logs/%s", name->buf));3398int retval =0;3399struct dirent *de;3400int oldlen = name->len;34013402if(!d)3403return name->len ? errno :0;34043405while((de =readdir(d)) != NULL) {3406struct stat st;34073408if(de->d_name[0] =='.')3409continue;3410if(has_extension(de->d_name,".lock"))3411continue;3412strbuf_addstr(name, de->d_name);3413if(stat(git_path("logs/%s", name->buf), &st) <0) {3414;/* silently ignore */3415}else{3416if(S_ISDIR(st.st_mode)) {3417strbuf_addch(name,'/');3418 retval =do_for_each_reflog(name, fn, cb_data);3419}else{3420unsigned char sha1[20];3421if(read_ref_full(name->buf, sha1,0, NULL))3422 retval =error("bad ref for%s", name->buf);3423else3424 retval =fn(name->buf, sha1,0, cb_data);3425}3426if(retval)3427break;3428}3429strbuf_setlen(name, oldlen);3430}3431closedir(d);3432return retval;3433}34343435intfor_each_reflog(each_ref_fn fn,void*cb_data)3436{3437int retval;3438struct strbuf name;3439strbuf_init(&name, PATH_MAX);3440 retval =do_for_each_reflog(&name, fn, cb_data);3441strbuf_release(&name);3442return retval;3443}34443445static struct ref_lock *update_ref_lock(const char*refname,3446const unsigned char*oldval,3447int flags,int*type_p,3448enum action_on_err onerr)3449{3450struct ref_lock *lock;3451 lock =lock_any_ref_for_update(refname, oldval, flags, type_p);3452if(!lock) {3453const char*str ="Cannot lock the ref '%s'.";3454switch(onerr) {3455case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3456case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3457case UPDATE_REFS_QUIET_ON_ERR:break;3458}3459}3460return lock;3461}34623463static intupdate_ref_write(const char*action,const char*refname,3464const unsigned char*sha1,struct ref_lock *lock,3465enum action_on_err onerr)3466{3467if(write_ref_sha1(lock, sha1, action) <0) {3468const char*str ="Cannot update the ref '%s'.";3469switch(onerr) {3470case UPDATE_REFS_MSG_ON_ERR:error(str, refname);break;3471case UPDATE_REFS_DIE_ON_ERR:die(str, refname);break;3472case UPDATE_REFS_QUIET_ON_ERR:break;3473}3474return1;3475}3476return0;3477}34783479/**3480 * Information needed for a single ref update. Set new_sha1 to the3481 * new value or to zero to delete the ref. To check the old value3482 * while locking the ref, set have_old to 1 and set old_sha1 to the3483 * value or to zero to ensure the ref does not exist before update.3484 */3485struct ref_update {3486unsigned char new_sha1[20];3487unsigned char old_sha1[20];3488int flags;/* REF_NODEREF? */3489int have_old;/* 1 if old_sha1 is valid, 0 otherwise */3490struct ref_lock *lock;3491int type;3492const char refname[FLEX_ARRAY];3493};34943495/*3496 * Data structure for holding a reference transaction, which can3497 * consist of checks and updates to multiple references, carried out3498 * as atomically as possible. This structure is opaque to callers.3499 */3500struct ref_transaction {3501struct ref_update **updates;3502size_t alloc;3503size_t nr;3504};35053506struct ref_transaction *ref_transaction_begin(void)3507{3508returnxcalloc(1,sizeof(struct ref_transaction));3509}35103511static voidref_transaction_free(struct ref_transaction *transaction)3512{3513int i;35143515for(i =0; i < transaction->nr; i++)3516free(transaction->updates[i]);35173518free(transaction->updates);3519free(transaction);3520}35213522voidref_transaction_rollback(struct ref_transaction *transaction)3523{3524ref_transaction_free(transaction);3525}35263527static struct ref_update *add_update(struct ref_transaction *transaction,3528const char*refname)3529{3530size_t len =strlen(refname);3531struct ref_update *update =xcalloc(1,sizeof(*update) + len +1);35323533strcpy((char*)update->refname, refname);3534ALLOC_GROW(transaction->updates, transaction->nr +1, transaction->alloc);3535 transaction->updates[transaction->nr++] = update;3536return update;3537}35383539voidref_transaction_update(struct ref_transaction *transaction,3540const char*refname,3541unsigned char*new_sha1,unsigned char*old_sha1,3542int flags,int have_old)3543{3544struct ref_update *update =add_update(transaction, refname);35453546hashcpy(update->new_sha1, new_sha1);3547 update->flags = flags;3548 update->have_old = have_old;3549if(have_old)3550hashcpy(update->old_sha1, old_sha1);3551}35523553voidref_transaction_create(struct ref_transaction *transaction,3554const char*refname,3555unsigned char*new_sha1,3556int flags)3557{3558struct ref_update *update =add_update(transaction, refname);35593560assert(!is_null_sha1(new_sha1));3561hashcpy(update->new_sha1, new_sha1);3562hashclr(update->old_sha1);3563 update->flags = flags;3564 update->have_old =1;3565}35663567voidref_transaction_delete(struct ref_transaction *transaction,3568const char*refname,3569unsigned char*old_sha1,3570int flags,int have_old)3571{3572struct ref_update *update =add_update(transaction, refname);35733574 update->flags = flags;3575 update->have_old = have_old;3576if(have_old) {3577assert(!is_null_sha1(old_sha1));3578hashcpy(update->old_sha1, old_sha1);3579}3580}35813582intupdate_ref(const char*action,const char*refname,3583const unsigned char*sha1,const unsigned char*oldval,3584int flags,enum action_on_err onerr)3585{3586struct ref_lock *lock;3587 lock =update_ref_lock(refname, oldval, flags, NULL, onerr);3588if(!lock)3589return1;3590returnupdate_ref_write(action, refname, sha1, lock, onerr);3591}35923593static intref_update_compare(const void*r1,const void*r2)3594{3595const struct ref_update *const*u1 = r1;3596const struct ref_update *const*u2 = r2;3597returnstrcmp((*u1)->refname, (*u2)->refname);3598}35993600static intref_update_reject_duplicates(struct ref_update **updates,int n,3601enum action_on_err onerr)3602{3603int i;3604for(i =1; i < n; i++)3605if(!strcmp(updates[i -1]->refname, updates[i]->refname)) {3606const char*str =3607"Multiple updates for ref '%s' not allowed.";3608switch(onerr) {3609case UPDATE_REFS_MSG_ON_ERR:3610error(str, updates[i]->refname);break;3611case UPDATE_REFS_DIE_ON_ERR:3612die(str, updates[i]->refname);break;3613case UPDATE_REFS_QUIET_ON_ERR:3614break;3615}3616return1;3617}3618return0;3619}36203621intref_transaction_commit(struct ref_transaction *transaction,3622const char*msg,enum action_on_err onerr)3623{3624int ret =0, delnum =0, i;3625const char**delnames;3626int n = transaction->nr;3627struct ref_update **updates = transaction->updates;36283629if(!n)3630return0;36313632/* Allocate work space */3633 delnames =xmalloc(sizeof(*delnames) * n);36343635/* Copy, sort, and reject duplicate refs */3636qsort(updates, n,sizeof(*updates), ref_update_compare);3637 ret =ref_update_reject_duplicates(updates, n, onerr);3638if(ret)3639goto cleanup;36403641/* Acquire all locks while verifying old values */3642for(i =0; i < n; i++) {3643struct ref_update *update = updates[i];36443645 update->lock =update_ref_lock(update->refname,3646(update->have_old ?3647 update->old_sha1 : NULL),3648 update->flags,3649&update->type, onerr);3650if(!update->lock) {3651 ret =1;3652goto cleanup;3653}3654}36553656/* Perform updates first so live commits remain referenced */3657for(i =0; i < n; i++) {3658struct ref_update *update = updates[i];36593660if(!is_null_sha1(update->new_sha1)) {3661 ret =update_ref_write(msg,3662 update->refname,3663 update->new_sha1,3664 update->lock, onerr);3665 update->lock = NULL;/* freed by update_ref_write */3666if(ret)3667goto cleanup;3668}3669}36703671/* Perform deletes now that updates are safely completed */3672for(i =0; i < n; i++) {3673struct ref_update *update = updates[i];36743675if(update->lock) {3676 delnames[delnum++] = update->lock->ref_name;3677 ret |=delete_ref_loose(update->lock, update->type);3678}3679}36803681 ret |=repack_without_refs(delnames, delnum);3682for(i =0; i < delnum; i++)3683unlink_or_warn(git_path("logs/%s", delnames[i]));3684clear_loose_ref_cache(&ref_cache);36853686cleanup:3687for(i =0; i < n; i++)3688if(updates[i]->lock)3689unlock_ref(updates[i]->lock);3690free(delnames);3691ref_transaction_free(transaction);3692return ret;3693}36943695char*shorten_unambiguous_ref(const char*refname,int strict)3696{3697int i;3698static char**scanf_fmts;3699static int nr_rules;3700char*short_name;37013702if(!nr_rules) {3703/*3704 * Pre-generate scanf formats from ref_rev_parse_rules[].3705 * Generate a format suitable for scanf from a3706 * ref_rev_parse_rules rule by interpolating "%s" at the3707 * location of the "%.*s".3708 */3709size_t total_len =0;3710size_t offset =0;37113712/* the rule list is NULL terminated, count them first */3713for(nr_rules =0; ref_rev_parse_rules[nr_rules]; nr_rules++)3714/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3715 total_len +=strlen(ref_rev_parse_rules[nr_rules]) -2+1;37163717 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);37183719 offset =0;3720for(i =0; i < nr_rules; i++) {3721assert(offset < total_len);3722 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules] + offset;3723 offset +=snprintf(scanf_fmts[i], total_len - offset,3724 ref_rev_parse_rules[i],2,"%s") +1;3725}3726}37273728/* bail out if there are no rules */3729if(!nr_rules)3730returnxstrdup(refname);37313732/* buffer for scanf result, at most refname must fit */3733 short_name =xstrdup(refname);37343735/* skip first rule, it will always match */3736for(i = nr_rules -1; i >0; --i) {3737int j;3738int rules_to_fail = i;3739int short_name_len;37403741if(1!=sscanf(refname, scanf_fmts[i], short_name))3742continue;37433744 short_name_len =strlen(short_name);37453746/*3747 * in strict mode, all (except the matched one) rules3748 * must fail to resolve to a valid non-ambiguous ref3749 */3750if(strict)3751 rules_to_fail = nr_rules;37523753/*3754 * check if the short name resolves to a valid ref,3755 * but use only rules prior to the matched one3756 */3757for(j =0; j < rules_to_fail; j++) {3758const char*rule = ref_rev_parse_rules[j];3759char refname[PATH_MAX];37603761/* skip matched rule */3762if(i == j)3763continue;37643765/*3766 * the short name is ambiguous, if it resolves3767 * (with this previous rule) to a valid ref3768 * read_ref() returns 0 on success3769 */3770mksnpath(refname,sizeof(refname),3771 rule, short_name_len, short_name);3772if(ref_exists(refname))3773break;3774}37753776/*3777 * short name is non-ambiguous if all previous rules3778 * haven't resolved to a valid ref3779 */3780if(j == rules_to_fail)3781return short_name;3782}37833784free(short_name);3785returnxstrdup(refname);3786}37873788static struct string_list *hide_refs;37893790intparse_hide_refs_config(const char*var,const char*value,const char*section)3791{3792if(!strcmp("transfer.hiderefs", var) ||3793/* NEEDSWORK: use parse_config_key() once both are merged */3794(starts_with(var, section) && var[strlen(section)] =='.'&&3795!strcmp(var +strlen(section),".hiderefs"))) {3796char*ref;3797int len;37983799if(!value)3800returnconfig_error_nonbool(var);3801 ref =xstrdup(value);3802 len =strlen(ref);3803while(len && ref[len -1] =='/')3804 ref[--len] ='\0';3805if(!hide_refs) {3806 hide_refs =xcalloc(1,sizeof(*hide_refs));3807 hide_refs->strdup_strings =1;3808}3809string_list_append(hide_refs, ref);3810}3811return0;3812}38133814intref_is_hidden(const char*refname)3815{3816struct string_list_item *item;38173818if(!hide_refs)3819return0;3820for_each_string_list_item(item, hide_refs) {3821int len;3822if(!starts_with(refname, item->string))3823continue;3824 len =strlen(item->string);3825if(!refname[len] || refname[len] =='/')3826return1;3827}3828return0;3829}