1#include"cache.h" 2#include"lockfile.h" 3#include"refs.h" 4#include"object.h" 5#include"tag.h" 6#include"dir.h" 7#include"string-list.h" 8 9struct ref_lock { 10char*ref_name; 11char*orig_ref_name; 12struct lock_file *lk; 13unsigned char old_sha1[20]; 14int lock_fd; 15int force_write; 16}; 17 18/* 19 * How to handle various characters in refnames: 20 * 0: An acceptable character for refs 21 * 1: End-of-component 22 * 2: ., look for a preceding . to reject .. in refs 23 * 3: {, look for a preceding @ to reject @{ in refs 24 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP 25 */ 26static unsigned char refname_disposition[256] = { 271,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 284,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 294,0,0,0,0,0,0,0,0,0,4,0,0,0,2,1, 300,0,0,0,0,0,0,0,0,0,4,0,0,0,0,4, 310,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 320,0,0,0,0,0,0,0,0,0,0,4,4,0,4,0, 330,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 340,0,0,0,0,0,0,0,0,0,0,3,0,0,4,4 35}; 36 37/* 38 * Used as a flag to ref_transaction_delete when a loose ref is being 39 * pruned. 40 */ 41#define REF_ISPRUNING 0x0100 42/* 43 * Try to read one refname component from the front of refname. 44 * Return the length of the component found, or -1 if the component is 45 * not legal. It is legal if it is something reasonable to have under 46 * ".git/refs/"; We do not like it if: 47 * 48 * - any path component of it begins with ".", or 49 * - it has double dots "..", or 50 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 51 * - it ends with a "/". 52 * - it ends with ".lock" 53 * - it contains a "\" (backslash) 54 */ 55static intcheck_refname_component(const char*refname,int flags) 56{ 57const char*cp; 58char last ='\0'; 59 60for(cp = refname; ; cp++) { 61int ch = *cp &255; 62unsigned char disp = refname_disposition[ch]; 63switch(disp) { 64case1: 65goto out; 66case2: 67if(last =='.') 68return-1;/* Refname contains "..". */ 69break; 70case3: 71if(last =='@') 72return-1;/* Refname contains "@{". */ 73break; 74case4: 75return-1; 76} 77 last = ch; 78} 79out: 80if(cp == refname) 81return0;/* Component has zero length. */ 82if(refname[0] =='.') 83return-1;/* Component starts with '.'. */ 84if(cp - refname >= LOCK_SUFFIX_LEN && 85!memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) 86return-1;/* Refname ends with ".lock". */ 87return cp - refname; 88} 89 90intcheck_refname_format(const char*refname,int flags) 91{ 92int component_len, component_count =0; 93 94if(!strcmp(refname,"@")) 95/* Refname is a single character '@'. */ 96return-1; 97 98while(1) { 99/* We are at the start of a path component. */ 100 component_len =check_refname_component(refname, flags); 101if(component_len <=0) { 102if((flags & REFNAME_REFSPEC_PATTERN) && 103 refname[0] =='*'&& 104(refname[1] =='\0'|| refname[1] =='/')) { 105/* Accept one wildcard as a full refname component. */ 106 flags &= ~REFNAME_REFSPEC_PATTERN; 107 component_len =1; 108}else{ 109return-1; 110} 111} 112 component_count++; 113if(refname[component_len] =='\0') 114break; 115/* Skip to next component. */ 116 refname += component_len +1; 117} 118 119if(refname[component_len -1] =='.') 120return-1;/* Refname ends with '.'. */ 121if(!(flags & REFNAME_ALLOW_ONELEVEL) && component_count <2) 122return-1;/* Refname has only one component. */ 123return0; 124} 125 126struct ref_entry; 127 128/* 129 * Information used (along with the information in ref_entry) to 130 * describe a single cached reference. This data structure only 131 * occurs embedded in a union in struct ref_entry, and only when 132 * (ref_entry->flag & REF_DIR) is zero. 133 */ 134struct ref_value { 135/* 136 * The name of the object to which this reference resolves 137 * (which may be a tag object). If REF_ISBROKEN, this is 138 * null. If REF_ISSYMREF, then this is the name of the object 139 * referred to by the last reference in the symlink chain. 140 */ 141unsigned char sha1[20]; 142 143/* 144 * If REF_KNOWS_PEELED, then this field holds the peeled value 145 * of this reference, or null if the reference is known not to 146 * be peelable. See the documentation for peel_ref() for an 147 * exact definition of "peelable". 148 */ 149unsigned char peeled[20]; 150}; 151 152struct ref_cache; 153 154/* 155 * Information used (along with the information in ref_entry) to 156 * describe a level in the hierarchy of references. This data 157 * structure only occurs embedded in a union in struct ref_entry, and 158 * only when (ref_entry.flag & REF_DIR) is set. In that case, 159 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 160 * in the directory have already been read: 161 * 162 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 163 * or packed references, already read. 164 * 165 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 166 * references that hasn't been read yet (nor has any of its 167 * subdirectories). 168 * 169 * Entries within a directory are stored within a growable array of 170 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 171 * sorted are sorted by their component name in strcmp() order and the 172 * remaining entries are unsorted. 173 * 174 * Loose references are read lazily, one directory at a time. When a 175 * directory of loose references is read, then all of the references 176 * in that directory are stored, and REF_INCOMPLETE stubs are created 177 * for any subdirectories, but the subdirectories themselves are not 178 * read. The reading is triggered by get_ref_dir(). 179 */ 180struct ref_dir { 181int nr, alloc; 182 183/* 184 * Entries with index 0 <= i < sorted are sorted by name. New 185 * entries are appended to the list unsorted, and are sorted 186 * only when required; thus we avoid the need to sort the list 187 * after the addition of every reference. 188 */ 189int sorted; 190 191/* A pointer to the ref_cache that contains this ref_dir. */ 192struct ref_cache *ref_cache; 193 194struct ref_entry **entries; 195}; 196 197/* 198 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 199 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 200 * public values; see refs.h. 201 */ 202 203/* 204 * The field ref_entry->u.value.peeled of this value entry contains 205 * the correct peeled value for the reference, which might be 206 * null_sha1 if the reference is not a tag or if it is broken. 207 */ 208#define REF_KNOWS_PEELED 0x10 209 210/* ref_entry represents a directory of references */ 211#define REF_DIR 0x20 212 213/* 214 * Entry has not yet been read from disk (used only for REF_DIR 215 * entries representing loose references) 216 */ 217#define REF_INCOMPLETE 0x40 218 219/* 220 * A ref_entry represents either a reference or a "subdirectory" of 221 * references. 222 * 223 * Each directory in the reference namespace is represented by a 224 * ref_entry with (flags & REF_DIR) set and containing a subdir member 225 * that holds the entries in that directory that have been read so 226 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 227 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 228 * used for loose reference directories. 229 * 230 * References are represented by a ref_entry with (flags & REF_DIR) 231 * unset and a value member that describes the reference's value. The 232 * flag member is at the ref_entry level, but it is also needed to 233 * interpret the contents of the value field (in other words, a 234 * ref_value object is not very much use without the enclosing 235 * ref_entry). 236 * 237 * Reference names cannot end with slash and directories' names are 238 * always stored with a trailing slash (except for the top-level 239 * directory, which is always denoted by ""). This has two nice 240 * consequences: (1) when the entries in each subdir are sorted 241 * lexicographically by name (as they usually are), the references in 242 * a whole tree can be generated in lexicographic order by traversing 243 * the tree in left-to-right, depth-first order; (2) the names of 244 * references and subdirectories cannot conflict, and therefore the 245 * presence of an empty subdirectory does not block the creation of a 246 * similarly-named reference. (The fact that reference names with the 247 * same leading components can conflict *with each other* is a 248 * separate issue that is regulated by is_refname_available().) 249 * 250 * Please note that the name field contains the fully-qualified 251 * reference (or subdirectory) name. Space could be saved by only 252 * storing the relative names. But that would require the full names 253 * to be generated on the fly when iterating in do_for_each_ref(), and 254 * would break callback functions, who have always been able to assume 255 * that the name strings that they are passed will not be freed during 256 * the iteration. 257 */ 258struct ref_entry { 259unsigned char flag;/* ISSYMREF? ISPACKED? */ 260union{ 261struct ref_value value;/* if not (flags&REF_DIR) */ 262struct ref_dir subdir;/* if (flags&REF_DIR) */ 263} u; 264/* 265 * The full name of the reference (e.g., "refs/heads/master") 266 * or the full name of the directory with a trailing slash 267 * (e.g., "refs/heads/"): 268 */ 269char name[FLEX_ARRAY]; 270}; 271 272static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 273 274static struct ref_dir *get_ref_dir(struct ref_entry *entry) 275{ 276struct ref_dir *dir; 277assert(entry->flag & REF_DIR); 278 dir = &entry->u.subdir; 279if(entry->flag & REF_INCOMPLETE) { 280read_loose_refs(entry->name, dir); 281 entry->flag &= ~REF_INCOMPLETE; 282} 283return dir; 284} 285 286/* 287 * Check if a refname is safe. 288 * For refs that start with "refs/" we consider it safe as long they do 289 * not try to resolve to outside of refs/. 290 * 291 * For all other refs we only consider them safe iff they only contain 292 * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like 293 * "config"). 294 */ 295static intrefname_is_safe(const char*refname) 296{ 297if(starts_with(refname,"refs/")) { 298char*buf; 299int result; 300 301 buf =xmalloc(strlen(refname) +1); 302/* 303 * Does the refname try to escape refs/? 304 * For example: refs/foo/../bar is safe but refs/foo/../../bar 305 * is not. 306 */ 307 result = !normalize_path_copy(buf, refname +strlen("refs/")); 308free(buf); 309return result; 310} 311while(*refname) { 312if(!isupper(*refname) && *refname !='_') 313return0; 314 refname++; 315} 316return1; 317} 318 319static struct ref_entry *create_ref_entry(const char*refname, 320const unsigned char*sha1,int flag, 321int check_name) 322{ 323int len; 324struct ref_entry *ref; 325 326if(check_name && 327check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 328die("Reference has invalid format: '%s'", refname); 329if(!check_name && !refname_is_safe(refname)) 330die("Reference has invalid name: '%s'", refname); 331 len =strlen(refname) +1; 332 ref =xmalloc(sizeof(struct ref_entry) + len); 333hashcpy(ref->u.value.sha1, sha1); 334hashclr(ref->u.value.peeled); 335memcpy(ref->name, refname, len); 336 ref->flag = flag; 337return ref; 338} 339 340static voidclear_ref_dir(struct ref_dir *dir); 341 342static voidfree_ref_entry(struct ref_entry *entry) 343{ 344if(entry->flag & REF_DIR) { 345/* 346 * Do not use get_ref_dir() here, as that might 347 * trigger the reading of loose refs. 348 */ 349clear_ref_dir(&entry->u.subdir); 350} 351free(entry); 352} 353 354/* 355 * Add a ref_entry to the end of dir (unsorted). Entry is always 356 * stored directly in dir; no recursion into subdirectories is 357 * done. 358 */ 359static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 360{ 361ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 362 dir->entries[dir->nr++] = entry; 363/* optimize for the case that entries are added in order */ 364if(dir->nr ==1|| 365(dir->nr == dir->sorted +1&& 366strcmp(dir->entries[dir->nr -2]->name, 367 dir->entries[dir->nr -1]->name) <0)) 368 dir->sorted = dir->nr; 369} 370 371/* 372 * Clear and free all entries in dir, recursively. 373 */ 374static voidclear_ref_dir(struct ref_dir *dir) 375{ 376int i; 377for(i =0; i < dir->nr; i++) 378free_ref_entry(dir->entries[i]); 379free(dir->entries); 380 dir->sorted = dir->nr = dir->alloc =0; 381 dir->entries = NULL; 382} 383 384/* 385 * Create a struct ref_entry object for the specified dirname. 386 * dirname is the name of the directory with a trailing slash (e.g., 387 * "refs/heads/") or "" for the top-level directory. 388 */ 389static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 390const char*dirname,size_t len, 391int incomplete) 392{ 393struct ref_entry *direntry; 394 direntry =xcalloc(1,sizeof(struct ref_entry) + len +1); 395memcpy(direntry->name, dirname, len); 396 direntry->name[len] ='\0'; 397 direntry->u.subdir.ref_cache = ref_cache; 398 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 399return direntry; 400} 401 402static intref_entry_cmp(const void*a,const void*b) 403{ 404struct ref_entry *one = *(struct ref_entry **)a; 405struct ref_entry *two = *(struct ref_entry **)b; 406returnstrcmp(one->name, two->name); 407} 408 409static voidsort_ref_dir(struct ref_dir *dir); 410 411struct string_slice { 412size_t len; 413const char*str; 414}; 415 416static intref_entry_cmp_sslice(const void*key_,const void*ent_) 417{ 418const struct string_slice *key = key_; 419const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 420int cmp =strncmp(key->str, ent->name, key->len); 421if(cmp) 422return cmp; 423return'\0'- (unsigned char)ent->name[key->len]; 424} 425 426/* 427 * Return the index of the entry with the given refname from the 428 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 429 * no such entry is found. dir must already be complete. 430 */ 431static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 432{ 433struct ref_entry **r; 434struct string_slice key; 435 436if(refname == NULL || !dir->nr) 437return-1; 438 439sort_ref_dir(dir); 440 key.len = len; 441 key.str = refname; 442 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 443 ref_entry_cmp_sslice); 444 445if(r == NULL) 446return-1; 447 448return r - dir->entries; 449} 450 451/* 452 * Search for a directory entry directly within dir (without 453 * recursing). Sort dir if necessary. subdirname must be a directory 454 * name (i.e., end in '/'). If mkdir is set, then create the 455 * directory if it is missing; otherwise, return NULL if the desired 456 * directory cannot be found. dir must already be complete. 457 */ 458static struct ref_dir *search_for_subdir(struct ref_dir *dir, 459const char*subdirname,size_t len, 460int mkdir) 461{ 462int entry_index =search_ref_dir(dir, subdirname, len); 463struct ref_entry *entry; 464if(entry_index == -1) { 465if(!mkdir) 466return NULL; 467/* 468 * Since dir is complete, the absence of a subdir 469 * means that the subdir really doesn't exist; 470 * therefore, create an empty record for it but mark 471 * the record complete. 472 */ 473 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 474add_entry_to_dir(dir, entry); 475}else{ 476 entry = dir->entries[entry_index]; 477} 478returnget_ref_dir(entry); 479} 480 481/* 482 * If refname is a reference name, find the ref_dir within the dir 483 * tree that should hold refname. If refname is a directory name 484 * (i.e., ends in '/'), then return that ref_dir itself. dir must 485 * represent the top-level directory and must already be complete. 486 * Sort ref_dirs and recurse into subdirectories as necessary. If 487 * mkdir is set, then create any missing directories; otherwise, 488 * return NULL if the desired directory cannot be found. 489 */ 490static struct ref_dir *find_containing_dir(struct ref_dir *dir, 491const char*refname,int mkdir) 492{ 493const char*slash; 494for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 495size_t dirnamelen = slash - refname +1; 496struct ref_dir *subdir; 497 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 498if(!subdir) { 499 dir = NULL; 500break; 501} 502 dir = subdir; 503} 504 505return dir; 506} 507 508/* 509 * Find the value entry with the given name in dir, sorting ref_dirs 510 * and recursing into subdirectories as necessary. If the name is not 511 * found or it corresponds to a directory entry, return NULL. 512 */ 513static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 514{ 515int entry_index; 516struct ref_entry *entry; 517 dir =find_containing_dir(dir, refname,0); 518if(!dir) 519return NULL; 520 entry_index =search_ref_dir(dir, refname,strlen(refname)); 521if(entry_index == -1) 522return NULL; 523 entry = dir->entries[entry_index]; 524return(entry->flag & REF_DIR) ? NULL : entry; 525} 526 527/* 528 * Remove the entry with the given name from dir, recursing into 529 * subdirectories as necessary. If refname is the name of a directory 530 * (i.e., ends with '/'), then remove the directory and its contents. 531 * If the removal was successful, return the number of entries 532 * remaining in the directory entry that contained the deleted entry. 533 * If the name was not found, return -1. Please note that this 534 * function only deletes the entry from the cache; it does not delete 535 * it from the filesystem or ensure that other cache entries (which 536 * might be symbolic references to the removed entry) are updated. 537 * Nor does it remove any containing dir entries that might be made 538 * empty by the removal. dir must represent the top-level directory 539 * and must already be complete. 540 */ 541static intremove_entry(struct ref_dir *dir,const char*refname) 542{ 543int refname_len =strlen(refname); 544int entry_index; 545struct ref_entry *entry; 546int is_dir = refname[refname_len -1] =='/'; 547if(is_dir) { 548/* 549 * refname represents a reference directory. Remove 550 * the trailing slash; otherwise we will get the 551 * directory *representing* refname rather than the 552 * one *containing* it. 553 */ 554char*dirname =xmemdupz(refname, refname_len -1); 555 dir =find_containing_dir(dir, dirname,0); 556free(dirname); 557}else{ 558 dir =find_containing_dir(dir, refname,0); 559} 560if(!dir) 561return-1; 562 entry_index =search_ref_dir(dir, refname, refname_len); 563if(entry_index == -1) 564return-1; 565 entry = dir->entries[entry_index]; 566 567memmove(&dir->entries[entry_index], 568&dir->entries[entry_index +1], 569(dir->nr - entry_index -1) *sizeof(*dir->entries) 570); 571 dir->nr--; 572if(dir->sorted > entry_index) 573 dir->sorted--; 574free_ref_entry(entry); 575return dir->nr; 576} 577 578/* 579 * Add a ref_entry to the ref_dir (unsorted), recursing into 580 * subdirectories as necessary. dir must represent the top-level 581 * directory. Return 0 on success. 582 */ 583static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 584{ 585 dir =find_containing_dir(dir, ref->name,1); 586if(!dir) 587return-1; 588add_entry_to_dir(dir, ref); 589return0; 590} 591 592/* 593 * Emit a warning and return true iff ref1 and ref2 have the same name 594 * and the same sha1. Die if they have the same name but different 595 * sha1s. 596 */ 597static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 598{ 599if(strcmp(ref1->name, ref2->name)) 600return0; 601 602/* Duplicate name; make sure that they don't conflict: */ 603 604if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 605/* This is impossible by construction */ 606die("Reference directory conflict:%s", ref1->name); 607 608if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 609die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 610 611warning("Duplicated ref:%s", ref1->name); 612return1; 613} 614 615/* 616 * Sort the entries in dir non-recursively (if they are not already 617 * sorted) and remove any duplicate entries. 618 */ 619static voidsort_ref_dir(struct ref_dir *dir) 620{ 621int i, j; 622struct ref_entry *last = NULL; 623 624/* 625 * This check also prevents passing a zero-length array to qsort(), 626 * which is a problem on some platforms. 627 */ 628if(dir->sorted == dir->nr) 629return; 630 631qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 632 633/* Remove any duplicates: */ 634for(i =0, j =0; j < dir->nr; j++) { 635struct ref_entry *entry = dir->entries[j]; 636if(last &&is_dup_ref(last, entry)) 637free_ref_entry(entry); 638else 639 last = dir->entries[i++] = entry; 640} 641 dir->sorted = dir->nr = i; 642} 643 644/* Include broken references in a do_for_each_ref*() iteration: */ 645#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 646 647/* 648 * Return true iff the reference described by entry can be resolved to 649 * an object in the database. Emit a warning if the referred-to 650 * object does not exist. 651 */ 652static intref_resolves_to_object(struct ref_entry *entry) 653{ 654if(entry->flag & REF_ISBROKEN) 655return0; 656if(!has_sha1_file(entry->u.value.sha1)) { 657error("%sdoes not point to a valid object!", entry->name); 658return0; 659} 660return1; 661} 662 663/* 664 * current_ref is a performance hack: when iterating over references 665 * using the for_each_ref*() functions, current_ref is set to the 666 * current reference's entry before calling the callback function. If 667 * the callback function calls peel_ref(), then peel_ref() first 668 * checks whether the reference to be peeled is the current reference 669 * (it usually is) and if so, returns that reference's peeled version 670 * if it is available. This avoids a refname lookup in a common case. 671 */ 672static struct ref_entry *current_ref; 673 674typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 675 676struct ref_entry_cb { 677const char*base; 678int trim; 679int flags; 680 each_ref_fn *fn; 681void*cb_data; 682}; 683 684/* 685 * Handle one reference in a do_for_each_ref*()-style iteration, 686 * calling an each_ref_fn for each entry. 687 */ 688static intdo_one_ref(struct ref_entry *entry,void*cb_data) 689{ 690struct ref_entry_cb *data = cb_data; 691struct ref_entry *old_current_ref; 692int retval; 693 694if(!starts_with(entry->name, data->base)) 695return0; 696 697if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 698!ref_resolves_to_object(entry)) 699return0; 700 701/* Store the old value, in case this is a recursive call: */ 702 old_current_ref = current_ref; 703 current_ref = entry; 704 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 705 entry->flag, data->cb_data); 706 current_ref = old_current_ref; 707return retval; 708} 709 710/* 711 * Call fn for each reference in dir that has index in the range 712 * offset <= index < dir->nr. Recurse into subdirectories that are in 713 * that index range, sorting them before iterating. This function 714 * does not sort dir itself; it should be sorted beforehand. fn is 715 * called for all references, including broken ones. 716 */ 717static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 718 each_ref_entry_fn fn,void*cb_data) 719{ 720int i; 721assert(dir->sorted == dir->nr); 722for(i = offset; i < dir->nr; i++) { 723struct ref_entry *entry = dir->entries[i]; 724int retval; 725if(entry->flag & REF_DIR) { 726struct ref_dir *subdir =get_ref_dir(entry); 727sort_ref_dir(subdir); 728 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 729}else{ 730 retval =fn(entry, cb_data); 731} 732if(retval) 733return retval; 734} 735return0; 736} 737 738/* 739 * Call fn for each reference in the union of dir1 and dir2, in order 740 * by refname. Recurse into subdirectories. If a value entry appears 741 * in both dir1 and dir2, then only process the version that is in 742 * dir2. The input dirs must already be sorted, but subdirs will be 743 * sorted as needed. fn is called for all references, including 744 * broken ones. 745 */ 746static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 747struct ref_dir *dir2, 748 each_ref_entry_fn fn,void*cb_data) 749{ 750int retval; 751int i1 =0, i2 =0; 752 753assert(dir1->sorted == dir1->nr); 754assert(dir2->sorted == dir2->nr); 755while(1) { 756struct ref_entry *e1, *e2; 757int cmp; 758if(i1 == dir1->nr) { 759returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 760} 761if(i2 == dir2->nr) { 762returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 763} 764 e1 = dir1->entries[i1]; 765 e2 = dir2->entries[i2]; 766 cmp =strcmp(e1->name, e2->name); 767if(cmp ==0) { 768if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 769/* Both are directories; descend them in parallel. */ 770struct ref_dir *subdir1 =get_ref_dir(e1); 771struct ref_dir *subdir2 =get_ref_dir(e2); 772sort_ref_dir(subdir1); 773sort_ref_dir(subdir2); 774 retval =do_for_each_entry_in_dirs( 775 subdir1, subdir2, fn, cb_data); 776 i1++; 777 i2++; 778}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 779/* Both are references; ignore the one from dir1. */ 780 retval =fn(e2, cb_data); 781 i1++; 782 i2++; 783}else{ 784die("conflict between reference and directory:%s", 785 e1->name); 786} 787}else{ 788struct ref_entry *e; 789if(cmp <0) { 790 e = e1; 791 i1++; 792}else{ 793 e = e2; 794 i2++; 795} 796if(e->flag & REF_DIR) { 797struct ref_dir *subdir =get_ref_dir(e); 798sort_ref_dir(subdir); 799 retval =do_for_each_entry_in_dir( 800 subdir,0, fn, cb_data); 801}else{ 802 retval =fn(e, cb_data); 803} 804} 805if(retval) 806return retval; 807} 808} 809 810/* 811 * Load all of the refs from the dir into our in-memory cache. The hard work 812 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 813 * through all of the sub-directories. We do not even need to care about 814 * sorting, as traversal order does not matter to us. 815 */ 816static voidprime_ref_dir(struct ref_dir *dir) 817{ 818int i; 819for(i =0; i < dir->nr; i++) { 820struct ref_entry *entry = dir->entries[i]; 821if(entry->flag & REF_DIR) 822prime_ref_dir(get_ref_dir(entry)); 823} 824} 825 826static intentry_matches(struct ref_entry *entry,const struct string_list *list) 827{ 828return list &&string_list_has_string(list, entry->name); 829} 830 831struct nonmatching_ref_data { 832const struct string_list *skip; 833struct ref_entry *found; 834}; 835 836static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 837{ 838struct nonmatching_ref_data *data = vdata; 839 840if(entry_matches(entry, data->skip)) 841return0; 842 843 data->found = entry; 844return1; 845} 846 847static voidreport_refname_conflict(struct ref_entry *entry, 848const char*refname) 849{ 850error("'%s' exists; cannot create '%s'", entry->name, refname); 851} 852 853/* 854 * Return true iff a reference named refname could be created without 855 * conflicting with the name of an existing reference in dir. If 856 * skip is non-NULL, ignore potential conflicts with refs in skip 857 * (e.g., because they are scheduled for deletion in the same 858 * operation). 859 * 860 * Two reference names conflict if one of them exactly matches the 861 * leading components of the other; e.g., "foo/bar" conflicts with 862 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 863 * "foo/barbados". 864 * 865 * skip must be sorted. 866 */ 867static intis_refname_available(const char*refname, 868const struct string_list *skip, 869struct ref_dir *dir) 870{ 871const char*slash; 872size_t len; 873int pos; 874char*dirname; 875 876for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 877/* 878 * We are still at a leading dir of the refname; we are 879 * looking for a conflict with a leaf entry. 880 * 881 * If we find one, we still must make sure it is 882 * not in "skip". 883 */ 884 pos =search_ref_dir(dir, refname, slash - refname); 885if(pos >=0) { 886struct ref_entry *entry = dir->entries[pos]; 887if(entry_matches(entry, skip)) 888return1; 889report_refname_conflict(entry, refname); 890return0; 891} 892 893 894/* 895 * Otherwise, we can try to continue our search with 896 * the next component; if we come up empty, we know 897 * there is nothing under this whole prefix. 898 */ 899 pos =search_ref_dir(dir, refname, slash +1- refname); 900if(pos <0) 901return1; 902 903 dir =get_ref_dir(dir->entries[pos]); 904} 905 906/* 907 * We are at the leaf of our refname; we want to 908 * make sure there are no directories which match it. 909 */ 910 len =strlen(refname); 911 dirname =xmallocz(len +1); 912sprintf(dirname,"%s/", refname); 913 pos =search_ref_dir(dir, dirname, len +1); 914free(dirname); 915 916if(pos >=0) { 917/* 918 * We found a directory named "refname". It is a 919 * problem iff it contains any ref that is not 920 * in "skip". 921 */ 922struct ref_entry *entry = dir->entries[pos]; 923struct ref_dir *dir =get_ref_dir(entry); 924struct nonmatching_ref_data data; 925 926 data.skip = skip; 927sort_ref_dir(dir); 928if(!do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) 929return1; 930 931report_refname_conflict(data.found, refname); 932return0; 933} 934 935/* 936 * There is no point in searching for another leaf 937 * node which matches it; such an entry would be the 938 * ref we are looking for, not a conflict. 939 */ 940return1; 941} 942 943struct packed_ref_cache { 944struct ref_entry *root; 945 946/* 947 * Count of references to the data structure in this instance, 948 * including the pointer from ref_cache::packed if any. The 949 * data will not be freed as long as the reference count is 950 * nonzero. 951 */ 952unsigned int referrers; 953 954/* 955 * Iff the packed-refs file associated with this instance is 956 * currently locked for writing, this points at the associated 957 * lock (which is owned by somebody else). The referrer count 958 * is also incremented when the file is locked and decremented 959 * when it is unlocked. 960 */ 961struct lock_file *lock; 962 963/* The metadata from when this packed-refs cache was read */ 964struct stat_validity validity; 965}; 966 967/* 968 * Future: need to be in "struct repository" 969 * when doing a full libification. 970 */ 971static struct ref_cache { 972struct ref_cache *next; 973struct ref_entry *loose; 974struct packed_ref_cache *packed; 975/* 976 * The submodule name, or "" for the main repo. We allocate 977 * length 1 rather than FLEX_ARRAY so that the main ref_cache 978 * is initialized correctly. 979 */ 980char name[1]; 981} ref_cache, *submodule_ref_caches; 982 983/* Lock used for the main packed-refs file: */ 984static struct lock_file packlock; 985 986/* 987 * Increment the reference count of *packed_refs. 988 */ 989static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 990{ 991 packed_refs->referrers++; 992} 993 994/* 995 * Decrease the reference count of *packed_refs. If it goes to zero, 996 * free *packed_refs and return true; otherwise return false. 997 */ 998static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 999{1000if(!--packed_refs->referrers) {1001free_ref_entry(packed_refs->root);1002stat_validity_clear(&packed_refs->validity);1003free(packed_refs);1004return1;1005}else{1006return0;1007}1008}10091010static voidclear_packed_ref_cache(struct ref_cache *refs)1011{1012if(refs->packed) {1013struct packed_ref_cache *packed_refs = refs->packed;10141015if(packed_refs->lock)1016die("internal error: packed-ref cache cleared while locked");1017 refs->packed = NULL;1018release_packed_ref_cache(packed_refs);1019}1020}10211022static voidclear_loose_ref_cache(struct ref_cache *refs)1023{1024if(refs->loose) {1025free_ref_entry(refs->loose);1026 refs->loose = NULL;1027}1028}10291030static struct ref_cache *create_ref_cache(const char*submodule)1031{1032int len;1033struct ref_cache *refs;1034if(!submodule)1035 submodule ="";1036 len =strlen(submodule) +1;1037 refs =xcalloc(1,sizeof(struct ref_cache) + len);1038memcpy(refs->name, submodule, len);1039return refs;1040}10411042/*1043 * Return a pointer to a ref_cache for the specified submodule. For1044 * the main repository, use submodule==NULL. The returned structure1045 * will be allocated and initialized but not necessarily populated; it1046 * should not be freed.1047 */1048static struct ref_cache *get_ref_cache(const char*submodule)1049{1050struct ref_cache *refs;10511052if(!submodule || !*submodule)1053return&ref_cache;10541055for(refs = submodule_ref_caches; refs; refs = refs->next)1056if(!strcmp(submodule, refs->name))1057return refs;10581059 refs =create_ref_cache(submodule);1060 refs->next = submodule_ref_caches;1061 submodule_ref_caches = refs;1062return refs;1063}10641065/* The length of a peeled reference line in packed-refs, including EOL: */1066#define PEELED_LINE_LENGTH 4210671068/*1069 * The packed-refs header line that we write out. Perhaps other1070 * traits will be added later. The trailing space is required.1071 */1072static const char PACKED_REFS_HEADER[] =1073"# pack-refs with: peeled fully-peeled\n";10741075/*1076 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1077 * Return a pointer to the refname within the line (null-terminated),1078 * or NULL if there was a problem.1079 */1080static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1081{1082const char*ref;10831084/*1085 * 42: the answer to everything.1086 *1087 * In this case, it happens to be the answer to1088 * 40 (length of sha1 hex representation)1089 * +1 (space in between hex and name)1090 * +1 (newline at the end of the line)1091 */1092if(line->len <=42)1093return NULL;10941095if(get_sha1_hex(line->buf, sha1) <0)1096return NULL;1097if(!isspace(line->buf[40]))1098return NULL;10991100 ref = line->buf +41;1101if(isspace(*ref))1102return NULL;11031104if(line->buf[line->len -1] !='\n')1105return NULL;1106 line->buf[--line->len] =0;11071108return ref;1109}11101111/*1112 * Read f, which is a packed-refs file, into dir.1113 *1114 * A comment line of the form "# pack-refs with: " may contain zero or1115 * more traits. We interpret the traits as follows:1116 *1117 * No traits:1118 *1119 * Probably no references are peeled. But if the file contains a1120 * peeled value for a reference, we will use it.1121 *1122 * peeled:1123 *1124 * References under "refs/tags/", if they *can* be peeled, *are*1125 * peeled in this file. References outside of "refs/tags/" are1126 * probably not peeled even if they could have been, but if we find1127 * a peeled value for such a reference we will use it.1128 *1129 * fully-peeled:1130 *1131 * All references in the file that can be peeled are peeled.1132 * Inversely (and this is more important), any references in the1133 * file for which no peeled value is recorded is not peelable. This1134 * trait should typically be written alongside "peeled" for1135 * compatibility with older clients, but we do not require it1136 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1137 */1138static voidread_packed_refs(FILE*f,struct ref_dir *dir)1139{1140struct ref_entry *last = NULL;1141struct strbuf line = STRBUF_INIT;1142enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11431144while(strbuf_getwholeline(&line, f,'\n') != EOF) {1145unsigned char sha1[20];1146const char*refname;1147const char*traits;11481149if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1150if(strstr(traits," fully-peeled "))1151 peeled = PEELED_FULLY;1152else if(strstr(traits," peeled "))1153 peeled = PEELED_TAGS;1154/* perhaps other traits later as well */1155continue;1156}11571158 refname =parse_ref_line(&line, sha1);1159if(refname) {1160int flag = REF_ISPACKED;11611162if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1163hashclr(sha1);1164 flag |= REF_BAD_NAME | REF_ISBROKEN;1165}1166 last =create_ref_entry(refname, sha1, flag,0);1167if(peeled == PEELED_FULLY ||1168(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1169 last->flag |= REF_KNOWS_PEELED;1170add_ref(dir, last);1171continue;1172}1173if(last &&1174 line.buf[0] =='^'&&1175 line.len == PEELED_LINE_LENGTH &&1176 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1177!get_sha1_hex(line.buf +1, sha1)) {1178hashcpy(last->u.value.peeled, sha1);1179/*1180 * Regardless of what the file header said,1181 * we definitely know the value of *this*1182 * reference:1183 */1184 last->flag |= REF_KNOWS_PEELED;1185}1186}11871188strbuf_release(&line);1189}11901191/*1192 * Get the packed_ref_cache for the specified ref_cache, creating it1193 * if necessary.1194 */1195static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1196{1197const char*packed_refs_file;11981199if(*refs->name)1200 packed_refs_file =git_path_submodule(refs->name,"packed-refs");1201else1202 packed_refs_file =git_path("packed-refs");12031204if(refs->packed &&1205!stat_validity_check(&refs->packed->validity, packed_refs_file))1206clear_packed_ref_cache(refs);12071208if(!refs->packed) {1209FILE*f;12101211 refs->packed =xcalloc(1,sizeof(*refs->packed));1212acquire_packed_ref_cache(refs->packed);1213 refs->packed->root =create_dir_entry(refs,"",0,0);1214 f =fopen(packed_refs_file,"r");1215if(f) {1216stat_validity_update(&refs->packed->validity,fileno(f));1217read_packed_refs(f,get_ref_dir(refs->packed->root));1218fclose(f);1219}1220}1221return refs->packed;1222}12231224static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1225{1226returnget_ref_dir(packed_ref_cache->root);1227}12281229static struct ref_dir *get_packed_refs(struct ref_cache *refs)1230{1231returnget_packed_ref_dir(get_packed_ref_cache(refs));1232}12331234voidadd_packed_ref(const char*refname,const unsigned char*sha1)1235{1236struct packed_ref_cache *packed_ref_cache =1237get_packed_ref_cache(&ref_cache);12381239if(!packed_ref_cache->lock)1240die("internal error: packed refs not locked");1241add_ref(get_packed_ref_dir(packed_ref_cache),1242create_ref_entry(refname, sha1, REF_ISPACKED,1));1243}12441245/*1246 * Read the loose references from the namespace dirname into dir1247 * (without recursing). dirname must end with '/'. dir must be the1248 * directory entry corresponding to dirname.1249 */1250static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1251{1252struct ref_cache *refs = dir->ref_cache;1253DIR*d;1254const char*path;1255struct dirent *de;1256int dirnamelen =strlen(dirname);1257struct strbuf refname;12581259if(*refs->name)1260 path =git_path_submodule(refs->name,"%s", dirname);1261else1262 path =git_path("%s", dirname);12631264 d =opendir(path);1265if(!d)1266return;12671268strbuf_init(&refname, dirnamelen +257);1269strbuf_add(&refname, dirname, dirnamelen);12701271while((de =readdir(d)) != NULL) {1272unsigned char sha1[20];1273struct stat st;1274int flag;1275const char*refdir;12761277if(de->d_name[0] =='.')1278continue;1279if(ends_with(de->d_name,".lock"))1280continue;1281strbuf_addstr(&refname, de->d_name);1282 refdir = *refs->name1283?git_path_submodule(refs->name,"%s", refname.buf)1284:git_path("%s", refname.buf);1285if(stat(refdir, &st) <0) {1286;/* silently ignore */1287}else if(S_ISDIR(st.st_mode)) {1288strbuf_addch(&refname,'/');1289add_entry_to_dir(dir,1290create_dir_entry(refs, refname.buf,1291 refname.len,1));1292}else{1293if(*refs->name) {1294hashclr(sha1);1295 flag =0;1296if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1297hashclr(sha1);1298 flag |= REF_ISBROKEN;1299}1300}else if(read_ref_full(refname.buf,1301 RESOLVE_REF_READING,1302 sha1, &flag)) {1303hashclr(sha1);1304 flag |= REF_ISBROKEN;1305}1306if(check_refname_format(refname.buf,1307 REFNAME_ALLOW_ONELEVEL)) {1308hashclr(sha1);1309 flag |= REF_BAD_NAME | REF_ISBROKEN;1310}1311add_entry_to_dir(dir,1312create_ref_entry(refname.buf, sha1, flag,0));1313}1314strbuf_setlen(&refname, dirnamelen);1315}1316strbuf_release(&refname);1317closedir(d);1318}13191320static struct ref_dir *get_loose_refs(struct ref_cache *refs)1321{1322if(!refs->loose) {1323/*1324 * Mark the top-level directory complete because we1325 * are about to read the only subdirectory that can1326 * hold references:1327 */1328 refs->loose =create_dir_entry(refs,"",0,0);1329/*1330 * Create an incomplete entry for "refs/":1331 */1332add_entry_to_dir(get_ref_dir(refs->loose),1333create_dir_entry(refs,"refs/",5,1));1334}1335returnget_ref_dir(refs->loose);1336}13371338/* We allow "recursive" symbolic refs. Only within reason, though */1339#define MAXDEPTH 51340#define MAXREFLEN (1024)13411342/*1343 * Called by resolve_gitlink_ref_recursive() after it failed to read1344 * from the loose refs in ref_cache refs. Find <refname> in the1345 * packed-refs file for the submodule.1346 */1347static intresolve_gitlink_packed_ref(struct ref_cache *refs,1348const char*refname,unsigned char*sha1)1349{1350struct ref_entry *ref;1351struct ref_dir *dir =get_packed_refs(refs);13521353 ref =find_ref(dir, refname);1354if(ref == NULL)1355return-1;13561357hashcpy(sha1, ref->u.value.sha1);1358return0;1359}13601361static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1362const char*refname,unsigned char*sha1,1363int recursion)1364{1365int fd, len;1366char buffer[128], *p;1367char*path;13681369if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1370return-1;1371 path = *refs->name1372?git_path_submodule(refs->name,"%s", refname)1373:git_path("%s", refname);1374 fd =open(path, O_RDONLY);1375if(fd <0)1376returnresolve_gitlink_packed_ref(refs, refname, sha1);13771378 len =read(fd, buffer,sizeof(buffer)-1);1379close(fd);1380if(len <0)1381return-1;1382while(len &&isspace(buffer[len-1]))1383 len--;1384 buffer[len] =0;13851386/* Was it a detached head or an old-fashioned symlink? */1387if(!get_sha1_hex(buffer, sha1))1388return0;13891390/* Symref? */1391if(strncmp(buffer,"ref:",4))1392return-1;1393 p = buffer +4;1394while(isspace(*p))1395 p++;13961397returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1398}13991400intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1401{1402int len =strlen(path), retval;1403char*submodule;1404struct ref_cache *refs;14051406while(len && path[len-1] =='/')1407 len--;1408if(!len)1409return-1;1410 submodule =xstrndup(path, len);1411 refs =get_ref_cache(submodule);1412free(submodule);14131414 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1415return retval;1416}14171418/*1419 * Return the ref_entry for the given refname from the packed1420 * references. If it does not exist, return NULL.1421 */1422static struct ref_entry *get_packed_ref(const char*refname)1423{1424returnfind_ref(get_packed_refs(&ref_cache), refname);1425}14261427/*1428 * A loose ref file doesn't exist; check for a packed ref. The1429 * options are forwarded from resolve_safe_unsafe().1430 */1431static intresolve_missing_loose_ref(const char*refname,1432int resolve_flags,1433unsigned char*sha1,1434int*flags)1435{1436struct ref_entry *entry;14371438/*1439 * The loose reference file does not exist; check for a packed1440 * reference.1441 */1442 entry =get_packed_ref(refname);1443if(entry) {1444hashcpy(sha1, entry->u.value.sha1);1445if(flags)1446*flags |= REF_ISPACKED;1447return0;1448}1449/* The reference is not a packed reference, either. */1450if(resolve_flags & RESOLVE_REF_READING) {1451 errno = ENOENT;1452return-1;1453}else{1454hashclr(sha1);1455return0;1456}1457}14581459/* This function needs to return a meaningful errno on failure */1460const char*resolve_ref_unsafe(const char*refname,int resolve_flags,unsigned char*sha1,int*flags)1461{1462int depth = MAXDEPTH;1463 ssize_t len;1464char buffer[256];1465static char refname_buffer[256];1466int bad_name =0;14671468if(flags)1469*flags =0;14701471if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1472if(flags)1473*flags |= REF_BAD_NAME;14741475if(!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1476!refname_is_safe(refname)) {1477 errno = EINVAL;1478return NULL;1479}1480/*1481 * dwim_ref() uses REF_ISBROKEN to distinguish between1482 * missing refs and refs that were present but invalid,1483 * to complain about the latter to stderr.1484 *1485 * We don't know whether the ref exists, so don't set1486 * REF_ISBROKEN yet.1487 */1488 bad_name =1;1489}1490for(;;) {1491char path[PATH_MAX];1492struct stat st;1493char*buf;1494int fd;14951496if(--depth <0) {1497 errno = ELOOP;1498return NULL;1499}15001501git_snpath(path,sizeof(path),"%s", refname);15021503/*1504 * We might have to loop back here to avoid a race1505 * condition: first we lstat() the file, then we try1506 * to read it as a link or as a file. But if somebody1507 * changes the type of the file (file <-> directory1508 * <-> symlink) between the lstat() and reading, then1509 * we don't want to report that as an error but rather1510 * try again starting with the lstat().1511 */1512 stat_ref:1513if(lstat(path, &st) <0) {1514if(errno != ENOENT)1515return NULL;1516if(resolve_missing_loose_ref(refname, resolve_flags,1517 sha1, flags))1518return NULL;1519if(bad_name) {1520hashclr(sha1);1521if(flags)1522*flags |= REF_ISBROKEN;1523}1524return refname;1525}15261527/* Follow "normalized" - ie "refs/.." symlinks by hand */1528if(S_ISLNK(st.st_mode)) {1529 len =readlink(path, buffer,sizeof(buffer)-1);1530if(len <0) {1531if(errno == ENOENT || errno == EINVAL)1532/* inconsistent with lstat; retry */1533goto stat_ref;1534else1535return NULL;1536}1537 buffer[len] =0;1538if(starts_with(buffer,"refs/") &&1539!check_refname_format(buffer,0)) {1540strcpy(refname_buffer, buffer);1541 refname = refname_buffer;1542if(flags)1543*flags |= REF_ISSYMREF;1544if(resolve_flags & RESOLVE_REF_NO_RECURSE) {1545hashclr(sha1);1546return refname;1547}1548continue;1549}1550}15511552/* Is it a directory? */1553if(S_ISDIR(st.st_mode)) {1554 errno = EISDIR;1555return NULL;1556}15571558/*1559 * Anything else, just open it and try to use it as1560 * a ref1561 */1562 fd =open(path, O_RDONLY);1563if(fd <0) {1564if(errno == ENOENT)1565/* inconsistent with lstat; retry */1566goto stat_ref;1567else1568return NULL;1569}1570 len =read_in_full(fd, buffer,sizeof(buffer)-1);1571if(len <0) {1572int save_errno = errno;1573close(fd);1574 errno = save_errno;1575return NULL;1576}1577close(fd);1578while(len &&isspace(buffer[len-1]))1579 len--;1580 buffer[len] ='\0';15811582/*1583 * Is it a symbolic ref?1584 */1585if(!starts_with(buffer,"ref:")) {1586/*1587 * Please note that FETCH_HEAD has a second1588 * line containing other data.1589 */1590if(get_sha1_hex(buffer, sha1) ||1591(buffer[40] !='\0'&& !isspace(buffer[40]))) {1592if(flags)1593*flags |= REF_ISBROKEN;1594 errno = EINVAL;1595return NULL;1596}1597if(bad_name) {1598hashclr(sha1);1599if(flags)1600*flags |= REF_ISBROKEN;1601}1602return refname;1603}1604if(flags)1605*flags |= REF_ISSYMREF;1606 buf = buffer +4;1607while(isspace(*buf))1608 buf++;1609 refname =strcpy(refname_buffer, buf);1610if(resolve_flags & RESOLVE_REF_NO_RECURSE) {1611hashclr(sha1);1612return refname;1613}1614if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1615if(flags)1616*flags |= REF_ISBROKEN;16171618if(!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1619!refname_is_safe(buf)) {1620 errno = EINVAL;1621return NULL;1622}1623 bad_name =1;1624}1625}1626}16271628char*resolve_refdup(const char*ref,int resolve_flags,unsigned char*sha1,int*flags)1629{1630const char*ret =resolve_ref_unsafe(ref, resolve_flags, sha1, flags);1631return ret ?xstrdup(ret) : NULL;1632}16331634/* The argument to filter_refs */1635struct ref_filter {1636const char*pattern;1637 each_ref_fn *fn;1638void*cb_data;1639};16401641intread_ref_full(const char*refname,int resolve_flags,unsigned char*sha1,int*flags)1642{1643if(resolve_ref_unsafe(refname, resolve_flags, sha1, flags))1644return0;1645return-1;1646}16471648intread_ref(const char*refname,unsigned char*sha1)1649{1650returnread_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);1651}16521653intref_exists(const char*refname)1654{1655unsigned char sha1[20];1656return!!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);1657}16581659static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1660void*data)1661{1662struct ref_filter *filter = (struct ref_filter *)data;1663if(wildmatch(filter->pattern, refname,0, NULL))1664return0;1665return filter->fn(refname, sha1, flags, filter->cb_data);1666}16671668enum peel_status {1669/* object was peeled successfully: */1670 PEEL_PEELED =0,16711672/*1673 * object cannot be peeled because the named object (or an1674 * object referred to by a tag in the peel chain), does not1675 * exist.1676 */1677 PEEL_INVALID = -1,16781679/* object cannot be peeled because it is not a tag: */1680 PEEL_NON_TAG = -2,16811682/* ref_entry contains no peeled value because it is a symref: */1683 PEEL_IS_SYMREF = -3,16841685/*1686 * ref_entry cannot be peeled because it is broken (i.e., the1687 * symbolic reference cannot even be resolved to an object1688 * name):1689 */1690 PEEL_BROKEN = -41691};16921693/*1694 * Peel the named object; i.e., if the object is a tag, resolve the1695 * tag recursively until a non-tag is found. If successful, store the1696 * result to sha1 and return PEEL_PEELED. If the object is not a tag1697 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1698 * and leave sha1 unchanged.1699 */1700static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1701{1702struct object *o =lookup_unknown_object(name);17031704if(o->type == OBJ_NONE) {1705int type =sha1_object_info(name, NULL);1706if(type <0|| !object_as_type(o, type,0))1707return PEEL_INVALID;1708}17091710if(o->type != OBJ_TAG)1711return PEEL_NON_TAG;17121713 o =deref_tag_noverify(o);1714if(!o)1715return PEEL_INVALID;17161717hashcpy(sha1, o->sha1);1718return PEEL_PEELED;1719}17201721/*1722 * Peel the entry (if possible) and return its new peel_status. If1723 * repeel is true, re-peel the entry even if there is an old peeled1724 * value that is already stored in it.1725 *1726 * It is OK to call this function with a packed reference entry that1727 * might be stale and might even refer to an object that has since1728 * been garbage-collected. In such a case, if the entry has1729 * REF_KNOWS_PEELED then leave the status unchanged and return1730 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1731 */1732static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1733{1734enum peel_status status;17351736if(entry->flag & REF_KNOWS_PEELED) {1737if(repeel) {1738 entry->flag &= ~REF_KNOWS_PEELED;1739hashclr(entry->u.value.peeled);1740}else{1741returnis_null_sha1(entry->u.value.peeled) ?1742 PEEL_NON_TAG : PEEL_PEELED;1743}1744}1745if(entry->flag & REF_ISBROKEN)1746return PEEL_BROKEN;1747if(entry->flag & REF_ISSYMREF)1748return PEEL_IS_SYMREF;17491750 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1751if(status == PEEL_PEELED || status == PEEL_NON_TAG)1752 entry->flag |= REF_KNOWS_PEELED;1753return status;1754}17551756intpeel_ref(const char*refname,unsigned char*sha1)1757{1758int flag;1759unsigned char base[20];17601761if(current_ref && (current_ref->name == refname1762|| !strcmp(current_ref->name, refname))) {1763if(peel_entry(current_ref,0))1764return-1;1765hashcpy(sha1, current_ref->u.value.peeled);1766return0;1767}17681769if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1770return-1;17711772/*1773 * If the reference is packed, read its ref_entry from the1774 * cache in the hope that we already know its peeled value.1775 * We only try this optimization on packed references because1776 * (a) forcing the filling of the loose reference cache could1777 * be expensive and (b) loose references anyway usually do not1778 * have REF_KNOWS_PEELED.1779 */1780if(flag & REF_ISPACKED) {1781struct ref_entry *r =get_packed_ref(refname);1782if(r) {1783if(peel_entry(r,0))1784return-1;1785hashcpy(sha1, r->u.value.peeled);1786return0;1787}1788}17891790returnpeel_object(base, sha1);1791}17921793struct warn_if_dangling_data {1794FILE*fp;1795const char*refname;1796const struct string_list *refnames;1797const char*msg_fmt;1798};17991800static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1801int flags,void*cb_data)1802{1803struct warn_if_dangling_data *d = cb_data;1804const char*resolves_to;1805unsigned char junk[20];18061807if(!(flags & REF_ISSYMREF))1808return0;18091810 resolves_to =resolve_ref_unsafe(refname,0, junk, NULL);1811if(!resolves_to1812|| (d->refname1813?strcmp(resolves_to, d->refname)1814: !string_list_has_string(d->refnames, resolves_to))) {1815return0;1816}18171818fprintf(d->fp, d->msg_fmt, refname);1819fputc('\n', d->fp);1820return0;1821}18221823voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1824{1825struct warn_if_dangling_data data;18261827 data.fp = fp;1828 data.refname = refname;1829 data.refnames = NULL;1830 data.msg_fmt = msg_fmt;1831for_each_rawref(warn_if_dangling_symref, &data);1832}18331834voidwarn_dangling_symrefs(FILE*fp,const char*msg_fmt,const struct string_list *refnames)1835{1836struct warn_if_dangling_data data;18371838 data.fp = fp;1839 data.refname = NULL;1840 data.refnames = refnames;1841 data.msg_fmt = msg_fmt;1842for_each_rawref(warn_if_dangling_symref, &data);1843}18441845/*1846 * Call fn for each reference in the specified ref_cache, omitting1847 * references not in the containing_dir of base. fn is called for all1848 * references, including broken ones. If fn ever returns a non-zero1849 * value, stop the iteration and return that value; otherwise, return1850 * 0.1851 */1852static intdo_for_each_entry(struct ref_cache *refs,const char*base,1853 each_ref_entry_fn fn,void*cb_data)1854{1855struct packed_ref_cache *packed_ref_cache;1856struct ref_dir *loose_dir;1857struct ref_dir *packed_dir;1858int retval =0;18591860/*1861 * We must make sure that all loose refs are read before accessing the1862 * packed-refs file; this avoids a race condition in which loose refs1863 * are migrated to the packed-refs file by a simultaneous process, but1864 * our in-memory view is from before the migration. get_packed_ref_cache()1865 * takes care of making sure our view is up to date with what is on1866 * disk.1867 */1868 loose_dir =get_loose_refs(refs);1869if(base && *base) {1870 loose_dir =find_containing_dir(loose_dir, base,0);1871}1872if(loose_dir)1873prime_ref_dir(loose_dir);18741875 packed_ref_cache =get_packed_ref_cache(refs);1876acquire_packed_ref_cache(packed_ref_cache);1877 packed_dir =get_packed_ref_dir(packed_ref_cache);1878if(base && *base) {1879 packed_dir =find_containing_dir(packed_dir, base,0);1880}18811882if(packed_dir && loose_dir) {1883sort_ref_dir(packed_dir);1884sort_ref_dir(loose_dir);1885 retval =do_for_each_entry_in_dirs(1886 packed_dir, loose_dir, fn, cb_data);1887}else if(packed_dir) {1888sort_ref_dir(packed_dir);1889 retval =do_for_each_entry_in_dir(1890 packed_dir,0, fn, cb_data);1891}else if(loose_dir) {1892sort_ref_dir(loose_dir);1893 retval =do_for_each_entry_in_dir(1894 loose_dir,0, fn, cb_data);1895}18961897release_packed_ref_cache(packed_ref_cache);1898return retval;1899}19001901/*1902 * Call fn for each reference in the specified ref_cache for which the1903 * refname begins with base. If trim is non-zero, then trim that many1904 * characters off the beginning of each refname before passing the1905 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1906 * broken references in the iteration. If fn ever returns a non-zero1907 * value, stop the iteration and return that value; otherwise, return1908 * 0.1909 */1910static intdo_for_each_ref(struct ref_cache *refs,const char*base,1911 each_ref_fn fn,int trim,int flags,void*cb_data)1912{1913struct ref_entry_cb data;1914 data.base = base;1915 data.trim = trim;1916 data.flags = flags;1917 data.fn = fn;1918 data.cb_data = cb_data;19191920returndo_for_each_entry(refs, base, do_one_ref, &data);1921}19221923static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1924{1925unsigned char sha1[20];1926int flag;19271928if(submodule) {1929if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1930returnfn("HEAD", sha1,0, cb_data);19311932return0;1933}19341935if(!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))1936returnfn("HEAD", sha1, flag, cb_data);19371938return0;1939}19401941inthead_ref(each_ref_fn fn,void*cb_data)1942{1943returndo_head_ref(NULL, fn, cb_data);1944}19451946inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1947{1948returndo_head_ref(submodule, fn, cb_data);1949}19501951intfor_each_ref(each_ref_fn fn,void*cb_data)1952{1953returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1954}19551956intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1957{1958returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1959}19601961intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1962{1963returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);1964}19651966intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1967 each_ref_fn fn,void*cb_data)1968{1969returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);1970}19711972intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1973{1974returnfor_each_ref_in("refs/tags/", fn, cb_data);1975}19761977intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1978{1979returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1980}19811982intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1983{1984returnfor_each_ref_in("refs/heads/", fn, cb_data);1985}19861987intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1988{1989returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);1990}19911992intfor_each_remote_ref(each_ref_fn fn,void*cb_data)1993{1994returnfor_each_ref_in("refs/remotes/", fn, cb_data);1995}19961997intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1998{1999returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);2000}20012002intfor_each_replace_ref(each_ref_fn fn,void*cb_data)2003{2004returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);2005}20062007inthead_ref_namespaced(each_ref_fn fn,void*cb_data)2008{2009struct strbuf buf = STRBUF_INIT;2010int ret =0;2011unsigned char sha1[20];2012int flag;20132014strbuf_addf(&buf,"%sHEAD",get_git_namespace());2015if(!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))2016 ret =fn(buf.buf, sha1, flag, cb_data);2017strbuf_release(&buf);20182019return ret;2020}20212022intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)2023{2024struct strbuf buf = STRBUF_INIT;2025int ret;2026strbuf_addf(&buf,"%srefs/",get_git_namespace());2027 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);2028strbuf_release(&buf);2029return ret;2030}20312032intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,2033const char*prefix,void*cb_data)2034{2035struct strbuf real_pattern = STRBUF_INIT;2036struct ref_filter filter;2037int ret;20382039if(!prefix && !starts_with(pattern,"refs/"))2040strbuf_addstr(&real_pattern,"refs/");2041else if(prefix)2042strbuf_addstr(&real_pattern, prefix);2043strbuf_addstr(&real_pattern, pattern);20442045if(!has_glob_specials(pattern)) {2046/* Append implied '/' '*' if not present. */2047if(real_pattern.buf[real_pattern.len -1] !='/')2048strbuf_addch(&real_pattern,'/');2049/* No need to check for '*', there is none. */2050strbuf_addch(&real_pattern,'*');2051}20522053 filter.pattern = real_pattern.buf;2054 filter.fn = fn;2055 filter.cb_data = cb_data;2056 ret =for_each_ref(filter_refs, &filter);20572058strbuf_release(&real_pattern);2059return ret;2060}20612062intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)2063{2064returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);2065}20662067intfor_each_rawref(each_ref_fn fn,void*cb_data)2068{2069returndo_for_each_ref(&ref_cache,"", fn,0,2070 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2071}20722073const char*prettify_refname(const char*name)2074{2075return name + (2076starts_with(name,"refs/heads/") ?11:2077starts_with(name,"refs/tags/") ?10:2078starts_with(name,"refs/remotes/") ?13:20790);2080}20812082static const char*ref_rev_parse_rules[] = {2083"%.*s",2084"refs/%.*s",2085"refs/tags/%.*s",2086"refs/heads/%.*s",2087"refs/remotes/%.*s",2088"refs/remotes/%.*s/HEAD",2089 NULL2090};20912092intrefname_match(const char*abbrev_name,const char*full_name)2093{2094const char**p;2095const int abbrev_name_len =strlen(abbrev_name);20962097for(p = ref_rev_parse_rules; *p; p++) {2098if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {2099return1;2100}2101}21022103return0;2104}21052106static voidunlock_ref(struct ref_lock *lock)2107{2108/* Do not free lock->lk -- atexit() still looks at them */2109if(lock->lk)2110rollback_lock_file(lock->lk);2111free(lock->ref_name);2112free(lock->orig_ref_name);2113free(lock);2114}21152116/* This function should make sure errno is meaningful on error */2117static struct ref_lock *verify_lock(struct ref_lock *lock,2118const unsigned char*old_sha1,int mustexist)2119{2120if(read_ref_full(lock->ref_name,2121 mustexist ? RESOLVE_REF_READING :0,2122 lock->old_sha1, NULL)) {2123int save_errno = errno;2124error("Can't verify ref%s", lock->ref_name);2125unlock_ref(lock);2126 errno = save_errno;2127return NULL;2128}2129if(hashcmp(lock->old_sha1, old_sha1)) {2130error("Ref%sis at%sbut expected%s", lock->ref_name,2131sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));2132unlock_ref(lock);2133 errno = EBUSY;2134return NULL;2135}2136return lock;2137}21382139static intremove_empty_directories(const char*file)2140{2141/* we want to create a file but there is a directory there;2142 * if that is an empty directory (or a directory that contains2143 * only empty directories), remove them.2144 */2145struct strbuf path;2146int result, save_errno;21472148strbuf_init(&path,20);2149strbuf_addstr(&path, file);21502151 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);2152 save_errno = errno;21532154strbuf_release(&path);2155 errno = save_errno;21562157return result;2158}21592160/*2161 * *string and *len will only be substituted, and *string returned (for2162 * later free()ing) if the string passed in is a magic short-hand form2163 * to name a branch.2164 */2165static char*substitute_branch_name(const char**string,int*len)2166{2167struct strbuf buf = STRBUF_INIT;2168int ret =interpret_branch_name(*string, *len, &buf);21692170if(ret == *len) {2171size_t size;2172*string =strbuf_detach(&buf, &size);2173*len = size;2174return(char*)*string;2175}21762177return NULL;2178}21792180intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)2181{2182char*last_branch =substitute_branch_name(&str, &len);2183const char**p, *r;2184int refs_found =0;21852186*ref = NULL;2187for(p = ref_rev_parse_rules; *p; p++) {2188char fullref[PATH_MAX];2189unsigned char sha1_from_ref[20];2190unsigned char*this_result;2191int flag;21922193 this_result = refs_found ? sha1_from_ref : sha1;2194mksnpath(fullref,sizeof(fullref), *p, len, str);2195 r =resolve_ref_unsafe(fullref, RESOLVE_REF_READING,2196 this_result, &flag);2197if(r) {2198if(!refs_found++)2199*ref =xstrdup(r);2200if(!warn_ambiguous_refs)2201break;2202}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {2203warning("ignoring dangling symref%s.", fullref);2204}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {2205warning("ignoring broken ref%s.", fullref);2206}2207}2208free(last_branch);2209return refs_found;2210}22112212intdwim_log(const char*str,int len,unsigned char*sha1,char**log)2213{2214char*last_branch =substitute_branch_name(&str, &len);2215const char**p;2216int logs_found =0;22172218*log = NULL;2219for(p = ref_rev_parse_rules; *p; p++) {2220unsigned char hash[20];2221char path[PATH_MAX];2222const char*ref, *it;22232224mksnpath(path,sizeof(path), *p, len, str);2225 ref =resolve_ref_unsafe(path, RESOLVE_REF_READING,2226 hash, NULL);2227if(!ref)2228continue;2229if(reflog_exists(path))2230 it = path;2231else if(strcmp(ref, path) &&reflog_exists(ref))2232 it = ref;2233else2234continue;2235if(!logs_found++) {2236*log =xstrdup(it);2237hashcpy(sha1, hash);2238}2239if(!warn_ambiguous_refs)2240break;2241}2242free(last_branch);2243return logs_found;2244}22452246/*2247 * Locks a ref returning the lock on success and NULL on failure.2248 * On failure errno is set to something meaningful.2249 */2250static struct ref_lock *lock_ref_sha1_basic(const char*refname,2251const unsigned char*old_sha1,2252const struct string_list *skip,2253int flags,int*type_p)2254{2255char*ref_file;2256const char*orig_refname = refname;2257struct ref_lock *lock;2258int last_errno =0;2259int type, lflags;2260int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2261int resolve_flags =0;2262int missing =0;2263int attempts_remaining =3;22642265 lock =xcalloc(1,sizeof(struct ref_lock));2266 lock->lock_fd = -1;22672268if(mustexist)2269 resolve_flags |= RESOLVE_REF_READING;2270if(flags & REF_DELETING) {2271 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;2272if(flags & REF_NODEREF)2273 resolve_flags |= RESOLVE_REF_NO_RECURSE;2274}22752276 refname =resolve_ref_unsafe(refname, resolve_flags,2277 lock->old_sha1, &type);2278if(!refname && errno == EISDIR) {2279/* we are trying to lock foo but we used to2280 * have foo/bar which now does not exist;2281 * it is normal for the empty directory 'foo'2282 * to remain.2283 */2284 ref_file =git_path("%s", orig_refname);2285if(remove_empty_directories(ref_file)) {2286 last_errno = errno;2287error("there are still refs under '%s'", orig_refname);2288goto error_return;2289}2290 refname =resolve_ref_unsafe(orig_refname, resolve_flags,2291 lock->old_sha1, &type);2292}2293if(type_p)2294*type_p = type;2295if(!refname) {2296 last_errno = errno;2297error("unable to resolve reference%s:%s",2298 orig_refname,strerror(errno));2299goto error_return;2300}2301 missing =is_null_sha1(lock->old_sha1);2302/* When the ref did not exist and we are creating it,2303 * make sure there is no existing ref that is packed2304 * whose name begins with our refname, nor a ref whose2305 * name is a proper prefix of our refname.2306 */2307if(missing &&2308!is_refname_available(refname, skip,get_packed_refs(&ref_cache))) {2309 last_errno = ENOTDIR;2310goto error_return;2311}23122313 lock->lk =xcalloc(1,sizeof(struct lock_file));23142315 lflags =0;2316if(flags & REF_NODEREF) {2317 refname = orig_refname;2318 lflags |= LOCK_NO_DEREF;2319}2320 lock->ref_name =xstrdup(refname);2321 lock->orig_ref_name =xstrdup(orig_refname);2322 ref_file =git_path("%s", refname);2323if(missing)2324 lock->force_write =1;2325if((flags & REF_NODEREF) && (type & REF_ISSYMREF))2326 lock->force_write =1;23272328 retry:2329switch(safe_create_leading_directories(ref_file)) {2330case SCLD_OK:2331break;/* success */2332case SCLD_VANISHED:2333if(--attempts_remaining >0)2334goto retry;2335/* fall through */2336default:2337 last_errno = errno;2338error("unable to create directory for%s", ref_file);2339goto error_return;2340}23412342 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);2343if(lock->lock_fd <0) {2344 last_errno = errno;2345if(errno == ENOENT && --attempts_remaining >0)2346/*2347 * Maybe somebody just deleted one of the2348 * directories leading to ref_file. Try2349 * again:2350 */2351goto retry;2352else{2353struct strbuf err = STRBUF_INIT;2354unable_to_lock_message(ref_file, errno, &err);2355error("%s", err.buf);2356strbuf_release(&err);2357goto error_return;2358}2359}2360return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;23612362 error_return:2363unlock_ref(lock);2364 errno = last_errno;2365return NULL;2366}23672368/*2369 * Write an entry to the packed-refs file for the specified refname.2370 * If peeled is non-NULL, write it as the entry's peeled value.2371 */2372static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2373unsigned char*peeled)2374{2375fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2376if(peeled)2377fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2378}23792380/*2381 * An each_ref_entry_fn that writes the entry to a packed-refs file.2382 */2383static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2384{2385enum peel_status peel_status =peel_entry(entry,0);23862387if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2388error("internal error:%sis not a valid packed reference!",2389 entry->name);2390write_packed_entry(cb_data, entry->name, entry->u.value.sha1,2391 peel_status == PEEL_PEELED ?2392 entry->u.value.peeled : NULL);2393return0;2394}23952396/* This should return a meaningful errno on failure */2397intlock_packed_refs(int flags)2398{2399struct packed_ref_cache *packed_ref_cache;24002401if(hold_lock_file_for_update(&packlock,git_path("packed-refs"), flags) <0)2402return-1;2403/*2404 * Get the current packed-refs while holding the lock. If the2405 * packed-refs file has been modified since we last read it,2406 * this will automatically invalidate the cache and re-read2407 * the packed-refs file.2408 */2409 packed_ref_cache =get_packed_ref_cache(&ref_cache);2410 packed_ref_cache->lock = &packlock;2411/* Increment the reference count to prevent it from being freed: */2412acquire_packed_ref_cache(packed_ref_cache);2413return0;2414}24152416/*2417 * Commit the packed refs changes.2418 * On error we must make sure that errno contains a meaningful value.2419 */2420intcommit_packed_refs(void)2421{2422struct packed_ref_cache *packed_ref_cache =2423get_packed_ref_cache(&ref_cache);2424int error =0;2425int save_errno =0;2426FILE*out;24272428if(!packed_ref_cache->lock)2429die("internal error: packed-refs not locked");24302431 out =fdopen_lock_file(packed_ref_cache->lock,"w");2432if(!out)2433die_errno("unable to fdopen packed-refs descriptor");24342435fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2436do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),24370, write_packed_entry_fn, out);24382439if(commit_lock_file(packed_ref_cache->lock)) {2440 save_errno = errno;2441 error = -1;2442}2443 packed_ref_cache->lock = NULL;2444release_packed_ref_cache(packed_ref_cache);2445 errno = save_errno;2446return error;2447}24482449voidrollback_packed_refs(void)2450{2451struct packed_ref_cache *packed_ref_cache =2452get_packed_ref_cache(&ref_cache);24532454if(!packed_ref_cache->lock)2455die("internal error: packed-refs not locked");2456rollback_lock_file(packed_ref_cache->lock);2457 packed_ref_cache->lock = NULL;2458release_packed_ref_cache(packed_ref_cache);2459clear_packed_ref_cache(&ref_cache);2460}24612462struct ref_to_prune {2463struct ref_to_prune *next;2464unsigned char sha1[20];2465char name[FLEX_ARRAY];2466};24672468struct pack_refs_cb_data {2469unsigned int flags;2470struct ref_dir *packed_refs;2471struct ref_to_prune *ref_to_prune;2472};24732474/*2475 * An each_ref_entry_fn that is run over loose references only. If2476 * the loose reference can be packed, add an entry in the packed ref2477 * cache. If the reference should be pruned, also add it to2478 * ref_to_prune in the pack_refs_cb_data.2479 */2480static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2481{2482struct pack_refs_cb_data *cb = cb_data;2483enum peel_status peel_status;2484struct ref_entry *packed_entry;2485int is_tag_ref =starts_with(entry->name,"refs/tags/");24862487/* ALWAYS pack tags */2488if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2489return0;24902491/* Do not pack symbolic or broken refs: */2492if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2493return0;24942495/* Add a packed ref cache entry equivalent to the loose entry. */2496 peel_status =peel_entry(entry,1);2497if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2498die("internal error peeling reference%s(%s)",2499 entry->name,sha1_to_hex(entry->u.value.sha1));2500 packed_entry =find_ref(cb->packed_refs, entry->name);2501if(packed_entry) {2502/* Overwrite existing packed entry with info from loose entry */2503 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2504hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2505}else{2506 packed_entry =create_ref_entry(entry->name, entry->u.value.sha1,2507 REF_ISPACKED | REF_KNOWS_PEELED,0);2508add_ref(cb->packed_refs, packed_entry);2509}2510hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);25112512/* Schedule the loose reference for pruning if requested. */2513if((cb->flags & PACK_REFS_PRUNE)) {2514int namelen =strlen(entry->name) +1;2515struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2516hashcpy(n->sha1, entry->u.value.sha1);2517strcpy(n->name, entry->name);2518 n->next = cb->ref_to_prune;2519 cb->ref_to_prune = n;2520}2521return0;2522}25232524/*2525 * Remove empty parents, but spare refs/ and immediate subdirs.2526 * Note: munges *name.2527 */2528static voidtry_remove_empty_parents(char*name)2529{2530char*p, *q;2531int i;2532 p = name;2533for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2534while(*p && *p !='/')2535 p++;2536/* tolerate duplicate slashes; see check_refname_format() */2537while(*p =='/')2538 p++;2539}2540for(q = p; *q; q++)2541;2542while(1) {2543while(q > p && *q !='/')2544 q--;2545while(q > p && *(q-1) =='/')2546 q--;2547if(q == p)2548break;2549*q ='\0';2550if(rmdir(git_path("%s", name)))2551break;2552}2553}25542555/* make sure nobody touched the ref, and unlink */2556static voidprune_ref(struct ref_to_prune *r)2557{2558struct ref_transaction *transaction;2559struct strbuf err = STRBUF_INIT;25602561if(check_refname_format(r->name,0))2562return;25632564 transaction =ref_transaction_begin(&err);2565if(!transaction ||2566ref_transaction_delete(transaction, r->name, r->sha1,2567 REF_ISPRUNING,1, NULL, &err) ||2568ref_transaction_commit(transaction, &err)) {2569ref_transaction_free(transaction);2570error("%s", err.buf);2571strbuf_release(&err);2572return;2573}2574ref_transaction_free(transaction);2575strbuf_release(&err);2576try_remove_empty_parents(r->name);2577}25782579static voidprune_refs(struct ref_to_prune *r)2580{2581while(r) {2582prune_ref(r);2583 r = r->next;2584}2585}25862587intpack_refs(unsigned int flags)2588{2589struct pack_refs_cb_data cbdata;25902591memset(&cbdata,0,sizeof(cbdata));2592 cbdata.flags = flags;25932594lock_packed_refs(LOCK_DIE_ON_ERROR);2595 cbdata.packed_refs =get_packed_refs(&ref_cache);25962597do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2598 pack_if_possible_fn, &cbdata);25992600if(commit_packed_refs())2601die_errno("unable to overwrite old ref-pack file");26022603prune_refs(cbdata.ref_to_prune);2604return0;2605}26062607/*2608 * If entry is no longer needed in packed-refs, add it to the string2609 * list pointed to by cb_data. Reasons for deleting entries:2610 *2611 * - Entry is broken.2612 * - Entry is overridden by a loose ref.2613 * - Entry does not point at a valid object.2614 *2615 * In the first and third cases, also emit an error message because these2616 * are indications of repository corruption.2617 */2618static intcurate_packed_ref_fn(struct ref_entry *entry,void*cb_data)2619{2620struct string_list *refs_to_delete = cb_data;26212622if(entry->flag & REF_ISBROKEN) {2623/* This shouldn't happen to packed refs. */2624error("%sis broken!", entry->name);2625string_list_append(refs_to_delete, entry->name);2626return0;2627}2628if(!has_sha1_file(entry->u.value.sha1)) {2629unsigned char sha1[20];2630int flags;26312632if(read_ref_full(entry->name,0, sha1, &flags))2633/* We should at least have found the packed ref. */2634die("Internal error");2635if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2636/*2637 * This packed reference is overridden by a2638 * loose reference, so it is OK that its value2639 * is no longer valid; for example, it might2640 * refer to an object that has been garbage2641 * collected. For this purpose we don't even2642 * care whether the loose reference itself is2643 * invalid, broken, symbolic, etc. Silently2644 * remove the packed reference.2645 */2646string_list_append(refs_to_delete, entry->name);2647return0;2648}2649/*2650 * There is no overriding loose reference, so the fact2651 * that this reference doesn't refer to a valid object2652 * indicates some kind of repository corruption.2653 * Report the problem, then omit the reference from2654 * the output.2655 */2656error("%sdoes not point to a valid object!", entry->name);2657string_list_append(refs_to_delete, entry->name);2658return0;2659}26602661return0;2662}26632664intrepack_without_refs(struct string_list *refnames,struct strbuf *err)2665{2666struct ref_dir *packed;2667struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2668struct string_list_item *refname, *ref_to_delete;2669int ret, needs_repacking =0, removed =0;26702671assert(err);26722673/* Look for a packed ref */2674for_each_string_list_item(refname, refnames) {2675if(get_packed_ref(refname->string)) {2676 needs_repacking =1;2677break;2678}2679}26802681/* Avoid locking if we have nothing to do */2682if(!needs_repacking)2683return0;/* no refname exists in packed refs */26842685if(lock_packed_refs(0)) {2686unable_to_lock_message(git_path("packed-refs"), errno, err);2687return-1;2688}2689 packed =get_packed_refs(&ref_cache);26902691/* Remove refnames from the cache */2692for_each_string_list_item(refname, refnames)2693if(remove_entry(packed, refname->string) != -1)2694 removed =1;2695if(!removed) {2696/*2697 * All packed entries disappeared while we were2698 * acquiring the lock.2699 */2700rollback_packed_refs();2701return0;2702}27032704/* Remove any other accumulated cruft */2705do_for_each_entry_in_dir(packed,0, curate_packed_ref_fn, &refs_to_delete);2706for_each_string_list_item(ref_to_delete, &refs_to_delete) {2707if(remove_entry(packed, ref_to_delete->string) == -1)2708die("internal error");2709}27102711/* Write what remains */2712 ret =commit_packed_refs();2713if(ret)2714strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2715strerror(errno));2716return ret;2717}27182719static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2720{2721assert(err);27222723if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2724/*2725 * loose. The loose file name is the same as the2726 * lockfile name, minus ".lock":2727 */2728char*loose_filename =get_locked_file_path(lock->lk);2729int res =unlink_or_msg(loose_filename, err);2730free(loose_filename);2731if(res)2732return1;2733}2734return0;2735}27362737intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2738{2739struct ref_transaction *transaction;2740struct strbuf err = STRBUF_INIT;27412742 transaction =ref_transaction_begin(&err);2743if(!transaction ||2744ref_transaction_delete(transaction, refname, sha1, delopt,2745 sha1 && !is_null_sha1(sha1), NULL, &err) ||2746ref_transaction_commit(transaction, &err)) {2747error("%s", err.buf);2748ref_transaction_free(transaction);2749strbuf_release(&err);2750return1;2751}2752ref_transaction_free(transaction);2753strbuf_release(&err);2754return0;2755}27562757/*2758 * People using contrib's git-new-workdir have .git/logs/refs ->2759 * /some/other/path/.git/logs/refs, and that may live on another device.2760 *2761 * IOW, to avoid cross device rename errors, the temporary renamed log must2762 * live into logs/refs.2763 */2764#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"27652766static intrename_tmp_log(const char*newrefname)2767{2768int attempts_remaining =4;27692770 retry:2771switch(safe_create_leading_directories(git_path("logs/%s", newrefname))) {2772case SCLD_OK:2773break;/* success */2774case SCLD_VANISHED:2775if(--attempts_remaining >0)2776goto retry;2777/* fall through */2778default:2779error("unable to create directory for%s", newrefname);2780return-1;2781}27822783if(rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2784if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2785/*2786 * rename(a, b) when b is an existing2787 * directory ought to result in ISDIR, but2788 * Solaris 5.8 gives ENOTDIR. Sheesh.2789 */2790if(remove_empty_directories(git_path("logs/%s", newrefname))) {2791error("Directory not empty: logs/%s", newrefname);2792return-1;2793}2794goto retry;2795}else if(errno == ENOENT && --attempts_remaining >0) {2796/*2797 * Maybe another process just deleted one of2798 * the directories in the path to newrefname.2799 * Try again from the beginning.2800 */2801goto retry;2802}else{2803error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2804 newrefname,strerror(errno));2805return-1;2806}2807}2808return0;2809}28102811static intrename_ref_available(const char*oldname,const char*newname)2812{2813struct string_list skip = STRING_LIST_INIT_NODUP;2814int ret;28152816string_list_insert(&skip, oldname);2817 ret =is_refname_available(newname, &skip,get_packed_refs(&ref_cache))2818&&is_refname_available(newname, &skip,get_loose_refs(&ref_cache));2819string_list_clear(&skip,0);2820return ret;2821}28222823static intwrite_ref_sha1(struct ref_lock *lock,const unsigned char*sha1,2824const char*logmsg);28252826intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2827{2828unsigned char sha1[20], orig_sha1[20];2829int flag =0, logmoved =0;2830struct ref_lock *lock;2831struct stat loginfo;2832int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2833const char*symref = NULL;28342835if(log &&S_ISLNK(loginfo.st_mode))2836returnerror("reflog for%sis a symlink", oldrefname);28372838 symref =resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,2839 orig_sha1, &flag);2840if(flag & REF_ISSYMREF)2841returnerror("refname%sis a symbolic ref, renaming it is not supported",2842 oldrefname);2843if(!symref)2844returnerror("refname%snot found", oldrefname);28452846if(!rename_ref_available(oldrefname, newrefname))2847return1;28482849if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2850returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2851 oldrefname,strerror(errno));28522853if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2854error("unable to delete old%s", oldrefname);2855goto rollback;2856}28572858if(!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2859delete_ref(newrefname, sha1, REF_NODEREF)) {2860if(errno==EISDIR) {2861if(remove_empty_directories(git_path("%s", newrefname))) {2862error("Directory not empty:%s", newrefname);2863goto rollback;2864}2865}else{2866error("unable to delete existing%s", newrefname);2867goto rollback;2868}2869}28702871if(log &&rename_tmp_log(newrefname))2872goto rollback;28732874 logmoved = log;28752876 lock =lock_ref_sha1_basic(newrefname, NULL, NULL,0, NULL);2877if(!lock) {2878error("unable to lock%sfor update", newrefname);2879goto rollback;2880}2881 lock->force_write =1;2882hashcpy(lock->old_sha1, orig_sha1);2883if(write_ref_sha1(lock, orig_sha1, logmsg)) {2884error("unable to write current sha1 into%s", newrefname);2885goto rollback;2886}28872888return0;28892890 rollback:2891 lock =lock_ref_sha1_basic(oldrefname, NULL, NULL,0, NULL);2892if(!lock) {2893error("unable to lock%sfor rollback", oldrefname);2894goto rollbacklog;2895}28962897 lock->force_write =1;2898 flag = log_all_ref_updates;2899 log_all_ref_updates =0;2900if(write_ref_sha1(lock, orig_sha1, NULL))2901error("unable to write current sha1 into%s", oldrefname);2902 log_all_ref_updates = flag;29032904 rollbacklog:2905if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2906error("unable to restore logfile%sfrom%s:%s",2907 oldrefname, newrefname,strerror(errno));2908if(!logmoved && log &&2909rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2910error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2911 oldrefname,strerror(errno));29122913return1;2914}29152916static intclose_ref(struct ref_lock *lock)2917{2918if(close_lock_file(lock->lk))2919return-1;2920 lock->lock_fd = -1;2921return0;2922}29232924static intcommit_ref(struct ref_lock *lock)2925{2926if(commit_lock_file(lock->lk))2927return-1;2928 lock->lock_fd = -1;2929return0;2930}29312932/*2933 * copy the reflog message msg to buf, which has been allocated sufficiently2934 * large, while cleaning up the whitespaces. Especially, convert LF to space,2935 * because reflog file is one line per entry.2936 */2937static intcopy_msg(char*buf,const char*msg)2938{2939char*cp = buf;2940char c;2941int wasspace =1;29422943*cp++ ='\t';2944while((c = *msg++)) {2945if(wasspace &&isspace(c))2946continue;2947 wasspace =isspace(c);2948if(wasspace)2949 c =' ';2950*cp++ = c;2951}2952while(buf < cp &&isspace(cp[-1]))2953 cp--;2954*cp++ ='\n';2955return cp - buf;2956}29572958/* This function must set a meaningful errno on failure */2959intlog_ref_setup(const char*refname,char*logfile,int bufsize)2960{2961int logfd, oflags = O_APPEND | O_WRONLY;29622963git_snpath(logfile, bufsize,"logs/%s", refname);2964if(log_all_ref_updates &&2965(starts_with(refname,"refs/heads/") ||2966starts_with(refname,"refs/remotes/") ||2967starts_with(refname,"refs/notes/") ||2968!strcmp(refname,"HEAD"))) {2969if(safe_create_leading_directories(logfile) <0) {2970int save_errno = errno;2971error("unable to create directory for%s", logfile);2972 errno = save_errno;2973return-1;2974}2975 oflags |= O_CREAT;2976}29772978 logfd =open(logfile, oflags,0666);2979if(logfd <0) {2980if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2981return0;29822983if(errno == EISDIR) {2984if(remove_empty_directories(logfile)) {2985int save_errno = errno;2986error("There are still logs under '%s'",2987 logfile);2988 errno = save_errno;2989return-1;2990}2991 logfd =open(logfile, oflags,0666);2992}29932994if(logfd <0) {2995int save_errno = errno;2996error("Unable to append to%s:%s", logfile,2997strerror(errno));2998 errno = save_errno;2999return-1;3000}3001}30023003adjust_shared_perm(logfile);3004close(logfd);3005return0;3006}30073008static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,3009const unsigned char*new_sha1,3010const char*committer,const char*msg)3011{3012int msglen, written;3013unsigned maxlen, len;3014char*logrec;30153016 msglen = msg ?strlen(msg) :0;3017 maxlen =strlen(committer) + msglen +100;3018 logrec =xmalloc(maxlen);3019 len =sprintf(logrec,"%s %s %s\n",3020sha1_to_hex(old_sha1),3021sha1_to_hex(new_sha1),3022 committer);3023if(msglen)3024 len +=copy_msg(logrec + len -1, msg) -1;30253026 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;3027free(logrec);3028if(written != len)3029return-1;30303031return0;3032}30333034static intlog_ref_write(const char*refname,const unsigned char*old_sha1,3035const unsigned char*new_sha1,const char*msg)3036{3037int logfd, result, oflags = O_APPEND | O_WRONLY;3038char log_file[PATH_MAX];30393040if(log_all_ref_updates <0)3041 log_all_ref_updates = !is_bare_repository();30423043 result =log_ref_setup(refname, log_file,sizeof(log_file));3044if(result)3045return result;30463047 logfd =open(log_file, oflags);3048if(logfd <0)3049return0;3050 result =log_ref_write_fd(logfd, old_sha1, new_sha1,3051git_committer_info(0), msg);3052if(result) {3053int save_errno = errno;3054close(logfd);3055error("Unable to append to%s", log_file);3056 errno = save_errno;3057return-1;3058}3059if(close(logfd)) {3060int save_errno = errno;3061error("Unable to append to%s", log_file);3062 errno = save_errno;3063return-1;3064}3065return0;3066}30673068intis_branch(const char*refname)3069{3070return!strcmp(refname,"HEAD") ||starts_with(refname,"refs/heads/");3071}30723073/*3074 * Write sha1 into the ref specified by the lock. Make sure that errno3075 * is sane on error.3076 */3077static intwrite_ref_sha1(struct ref_lock *lock,3078const unsigned char*sha1,const char*logmsg)3079{3080static char term ='\n';3081struct object *o;30823083if(!lock) {3084 errno = EINVAL;3085return-1;3086}3087if(!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {3088unlock_ref(lock);3089return0;3090}3091 o =parse_object(sha1);3092if(!o) {3093error("Trying to write ref%swith nonexistent object%s",3094 lock->ref_name,sha1_to_hex(sha1));3095unlock_ref(lock);3096 errno = EINVAL;3097return-1;3098}3099if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {3100error("Trying to write non-commit object%sto branch%s",3101sha1_to_hex(sha1), lock->ref_name);3102unlock_ref(lock);3103 errno = EINVAL;3104return-1;3105}3106if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||3107write_in_full(lock->lock_fd, &term,1) !=1||3108close_ref(lock) <0) {3109int save_errno = errno;3110error("Couldn't write%s", lock->lk->filename.buf);3111unlock_ref(lock);3112 errno = save_errno;3113return-1;3114}3115clear_loose_ref_cache(&ref_cache);3116if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||3117(strcmp(lock->ref_name, lock->orig_ref_name) &&3118log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {3119unlock_ref(lock);3120return-1;3121}3122if(strcmp(lock->orig_ref_name,"HEAD") !=0) {3123/*3124 * Special hack: If a branch is updated directly and HEAD3125 * points to it (may happen on the remote side of a push3126 * for example) then logically the HEAD reflog should be3127 * updated too.3128 * A generic solution implies reverse symref information,3129 * but finding all symrefs pointing to the given branch3130 * would be rather costly for this rare event (the direct3131 * update of a branch) to be worth it. So let's cheat and3132 * check with HEAD only which should cover 99% of all usage3133 * scenarios (even 100% of the default ones).3134 */3135unsigned char head_sha1[20];3136int head_flag;3137const char*head_ref;3138 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3139 head_sha1, &head_flag);3140if(head_ref && (head_flag & REF_ISSYMREF) &&3141!strcmp(head_ref, lock->ref_name))3142log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3143}3144if(commit_ref(lock)) {3145error("Couldn't set%s", lock->ref_name);3146unlock_ref(lock);3147return-1;3148}3149unlock_ref(lock);3150return0;3151}31523153intcreate_symref(const char*ref_target,const char*refs_heads_master,3154const char*logmsg)3155{3156const char*lockpath;3157char ref[1000];3158int fd, len, written;3159char*git_HEAD =git_pathdup("%s", ref_target);3160unsigned char old_sha1[20], new_sha1[20];31613162if(logmsg &&read_ref(ref_target, old_sha1))3163hashclr(old_sha1);31643165if(safe_create_leading_directories(git_HEAD) <0)3166returnerror("unable to create directory for%s", git_HEAD);31673168#ifndef NO_SYMLINK_HEAD3169if(prefer_symlink_refs) {3170unlink(git_HEAD);3171if(!symlink(refs_heads_master, git_HEAD))3172goto done;3173fprintf(stderr,"no symlink - falling back to symbolic ref\n");3174}3175#endif31763177 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);3178if(sizeof(ref) <= len) {3179error("refname too long:%s", refs_heads_master);3180goto error_free_return;3181}3182 lockpath =mkpath("%s.lock", git_HEAD);3183 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);3184if(fd <0) {3185error("Unable to open%sfor writing", lockpath);3186goto error_free_return;3187}3188 written =write_in_full(fd, ref, len);3189if(close(fd) !=0|| written != len) {3190error("Unable to write to%s", lockpath);3191goto error_unlink_return;3192}3193if(rename(lockpath, git_HEAD) <0) {3194error("Unable to create%s", git_HEAD);3195goto error_unlink_return;3196}3197if(adjust_shared_perm(git_HEAD)) {3198error("Unable to fix permissions on%s", lockpath);3199 error_unlink_return:3200unlink_or_warn(lockpath);3201 error_free_return:3202free(git_HEAD);3203return-1;3204}32053206#ifndef NO_SYMLINK_HEAD3207 done:3208#endif3209if(logmsg && !read_ref(refs_heads_master, new_sha1))3210log_ref_write(ref_target, old_sha1, new_sha1, logmsg);32113212free(git_HEAD);3213return0;3214}32153216struct read_ref_at_cb {3217const char*refname;3218unsigned long at_time;3219int cnt;3220int reccnt;3221unsigned char*sha1;3222int found_it;32233224unsigned char osha1[20];3225unsigned char nsha1[20];3226int tz;3227unsigned long date;3228char**msg;3229unsigned long*cutoff_time;3230int*cutoff_tz;3231int*cutoff_cnt;3232};32333234static intread_ref_at_ent(unsigned char*osha1,unsigned char*nsha1,3235const char*email,unsigned long timestamp,int tz,3236const char*message,void*cb_data)3237{3238struct read_ref_at_cb *cb = cb_data;32393240 cb->reccnt++;3241 cb->tz = tz;3242 cb->date = timestamp;32433244if(timestamp <= cb->at_time || cb->cnt ==0) {3245if(cb->msg)3246*cb->msg =xstrdup(message);3247if(cb->cutoff_time)3248*cb->cutoff_time = timestamp;3249if(cb->cutoff_tz)3250*cb->cutoff_tz = tz;3251if(cb->cutoff_cnt)3252*cb->cutoff_cnt = cb->reccnt -1;3253/*3254 * we have not yet updated cb->[n|o]sha1 so they still3255 * hold the values for the previous record.3256 */3257if(!is_null_sha1(cb->osha1)) {3258hashcpy(cb->sha1, nsha1);3259if(hashcmp(cb->osha1, nsha1))3260warning("Log for ref%shas gap after%s.",3261 cb->refname,show_date(cb->date, cb->tz, DATE_RFC2822));3262}3263else if(cb->date == cb->at_time)3264hashcpy(cb->sha1, nsha1);3265else if(hashcmp(nsha1, cb->sha1))3266warning("Log for ref%sunexpectedly ended on%s.",3267 cb->refname,show_date(cb->date, cb->tz,3268 DATE_RFC2822));3269hashcpy(cb->osha1, osha1);3270hashcpy(cb->nsha1, nsha1);3271 cb->found_it =1;3272return1;3273}3274hashcpy(cb->osha1, osha1);3275hashcpy(cb->nsha1, nsha1);3276if(cb->cnt >0)3277 cb->cnt--;3278return0;3279}32803281static intread_ref_at_ent_oldest(unsigned char*osha1,unsigned char*nsha1,3282const char*email,unsigned long timestamp,3283int tz,const char*message,void*cb_data)3284{3285struct read_ref_at_cb *cb = cb_data;32863287if(cb->msg)3288*cb->msg =xstrdup(message);3289if(cb->cutoff_time)3290*cb->cutoff_time = timestamp;3291if(cb->cutoff_tz)3292*cb->cutoff_tz = tz;3293if(cb->cutoff_cnt)3294*cb->cutoff_cnt = cb->reccnt;3295hashcpy(cb->sha1, osha1);3296if(is_null_sha1(cb->sha1))3297hashcpy(cb->sha1, nsha1);3298/* We just want the first entry */3299return1;3300}33013302intread_ref_at(const char*refname,unsigned int flags,unsigned long at_time,int cnt,3303unsigned char*sha1,char**msg,3304unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)3305{3306struct read_ref_at_cb cb;33073308memset(&cb,0,sizeof(cb));3309 cb.refname = refname;3310 cb.at_time = at_time;3311 cb.cnt = cnt;3312 cb.msg = msg;3313 cb.cutoff_time = cutoff_time;3314 cb.cutoff_tz = cutoff_tz;3315 cb.cutoff_cnt = cutoff_cnt;3316 cb.sha1 = sha1;33173318for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);33193320if(!cb.reccnt) {3321if(flags & GET_SHA1_QUIETLY)3322exit(128);3323else3324die("Log for%sis empty.", refname);3325}3326if(cb.found_it)3327return0;33283329for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);33303331return1;3332}33333334intreflog_exists(const char*refname)3335{3336struct stat st;33373338return!lstat(git_path("logs/%s", refname), &st) &&3339S_ISREG(st.st_mode);3340}33413342intdelete_reflog(const char*refname)3343{3344returnremove_path(git_path("logs/%s", refname));3345}33463347static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3348{3349unsigned char osha1[20], nsha1[20];3350char*email_end, *message;3351unsigned long timestamp;3352int tz;33533354/* old SP new SP name <email> SP time TAB msg LF */3355if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3356get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3357get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3358!(email_end =strchr(sb->buf +82,'>')) ||3359 email_end[1] !=' '||3360!(timestamp =strtoul(email_end +2, &message,10)) ||3361!message || message[0] !=' '||3362(message[1] !='+'&& message[1] !='-') ||3363!isdigit(message[2]) || !isdigit(message[3]) ||3364!isdigit(message[4]) || !isdigit(message[5]))3365return0;/* corrupt? */3366 email_end[1] ='\0';3367 tz =strtol(message +1, NULL,10);3368if(message[6] !='\t')3369 message +=6;3370else3371 message +=7;3372returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3373}33743375static char*find_beginning_of_line(char*bob,char*scan)3376{3377while(bob < scan && *(--scan) !='\n')3378;/* keep scanning backwards */3379/*3380 * Return either beginning of the buffer, or LF at the end of3381 * the previous line.3382 */3383return scan;3384}33853386intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3387{3388struct strbuf sb = STRBUF_INIT;3389FILE*logfp;3390long pos;3391int ret =0, at_tail =1;33923393 logfp =fopen(git_path("logs/%s", refname),"r");3394if(!logfp)3395return-1;33963397/* Jump to the end */3398if(fseek(logfp,0, SEEK_END) <0)3399returnerror("cannot seek back reflog for%s:%s",3400 refname,strerror(errno));3401 pos =ftell(logfp);3402while(!ret &&0< pos) {3403int cnt;3404size_t nread;3405char buf[BUFSIZ];3406char*endp, *scanp;34073408/* Fill next block from the end */3409 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3410if(fseek(logfp, pos - cnt, SEEK_SET))3411returnerror("cannot seek back reflog for%s:%s",3412 refname,strerror(errno));3413 nread =fread(buf, cnt,1, logfp);3414if(nread !=1)3415returnerror("cannot read%dbytes from reflog for%s:%s",3416 cnt, refname,strerror(errno));3417 pos -= cnt;34183419 scanp = endp = buf + cnt;3420if(at_tail && scanp[-1] =='\n')3421/* Looking at the final LF at the end of the file */3422 scanp--;3423 at_tail =0;34243425while(buf < scanp) {3426/*3427 * terminating LF of the previous line, or the beginning3428 * of the buffer.3429 */3430char*bp;34313432 bp =find_beginning_of_line(buf, scanp);34333434if(*bp =='\n') {3435/*3436 * The newline is the end of the previous line,3437 * so we know we have complete line starting3438 * at (bp + 1). Prefix it onto any prior data3439 * we collected for the line and process it.3440 */3441strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3442 scanp = bp;3443 endp = bp +1;3444 ret =show_one_reflog_ent(&sb, fn, cb_data);3445strbuf_reset(&sb);3446if(ret)3447break;3448}else if(!pos) {3449/*3450 * We are at the start of the buffer, and the3451 * start of the file; there is no previous3452 * line, and we have everything for this one.3453 * Process it, and we can end the loop.3454 */3455strbuf_splice(&sb,0,0, buf, endp - buf);3456 ret =show_one_reflog_ent(&sb, fn, cb_data);3457strbuf_reset(&sb);3458break;3459}34603461if(bp == buf) {3462/*3463 * We are at the start of the buffer, and there3464 * is more file to read backwards. Which means3465 * we are in the middle of a line. Note that we3466 * may get here even if *bp was a newline; that3467 * just means we are at the exact end of the3468 * previous line, rather than some spot in the3469 * middle.3470 *3471 * Save away what we have to be combined with3472 * the data from the next read.3473 */3474strbuf_splice(&sb,0,0, buf, endp - buf);3475break;3476}3477}34783479}3480if(!ret && sb.len)3481die("BUG: reverse reflog parser had leftover data");34823483fclose(logfp);3484strbuf_release(&sb);3485return ret;3486}34873488intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3489{3490FILE*logfp;3491struct strbuf sb = STRBUF_INIT;3492int ret =0;34933494 logfp =fopen(git_path("logs/%s", refname),"r");3495if(!logfp)3496return-1;34973498while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3499 ret =show_one_reflog_ent(&sb, fn, cb_data);3500fclose(logfp);3501strbuf_release(&sb);3502return ret;3503}3504/*3505 * Call fn for each reflog in the namespace indicated by name. name3506 * must be empty or end with '/'. Name will be used as a scratch3507 * space, but its contents will be restored before return.3508 */3509static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3510{3511DIR*d =opendir(git_path("logs/%s", name->buf));3512int retval =0;3513struct dirent *de;3514int oldlen = name->len;35153516if(!d)3517return name->len ? errno :0;35183519while((de =readdir(d)) != NULL) {3520struct stat st;35213522if(de->d_name[0] =='.')3523continue;3524if(ends_with(de->d_name,".lock"))3525continue;3526strbuf_addstr(name, de->d_name);3527if(stat(git_path("logs/%s", name->buf), &st) <0) {3528;/* silently ignore */3529}else{3530if(S_ISDIR(st.st_mode)) {3531strbuf_addch(name,'/');3532 retval =do_for_each_reflog(name, fn, cb_data);3533}else{3534unsigned char sha1[20];3535if(read_ref_full(name->buf,0, sha1, NULL))3536 retval =error("bad ref for%s", name->buf);3537else3538 retval =fn(name->buf, sha1,0, cb_data);3539}3540if(retval)3541break;3542}3543strbuf_setlen(name, oldlen);3544}3545closedir(d);3546return retval;3547}35483549intfor_each_reflog(each_ref_fn fn,void*cb_data)3550{3551int retval;3552struct strbuf name;3553strbuf_init(&name, PATH_MAX);3554 retval =do_for_each_reflog(&name, fn, cb_data);3555strbuf_release(&name);3556return retval;3557}35583559/**3560 * Information needed for a single ref update. Set new_sha1 to the3561 * new value or to zero to delete the ref. To check the old value3562 * while locking the ref, set have_old to 1 and set old_sha1 to the3563 * value or to zero to ensure the ref does not exist before update.3564 */3565struct ref_update {3566unsigned char new_sha1[20];3567unsigned char old_sha1[20];3568int flags;/* REF_NODEREF? */3569int have_old;/* 1 if old_sha1 is valid, 0 otherwise */3570struct ref_lock *lock;3571int type;3572char*msg;3573const char refname[FLEX_ARRAY];3574};35753576/*3577 * Transaction states.3578 * OPEN: The transaction is in a valid state and can accept new updates.3579 * An OPEN transaction can be committed.3580 * CLOSED: A closed transaction is no longer active and no other operations3581 * than free can be used on it in this state.3582 * A transaction can either become closed by successfully committing3583 * an active transaction or if there is a failure while building3584 * the transaction thus rendering it failed/inactive.3585 */3586enum ref_transaction_state {3587 REF_TRANSACTION_OPEN =0,3588 REF_TRANSACTION_CLOSED =13589};35903591/*3592 * Data structure for holding a reference transaction, which can3593 * consist of checks and updates to multiple references, carried out3594 * as atomically as possible. This structure is opaque to callers.3595 */3596struct ref_transaction {3597struct ref_update **updates;3598size_t alloc;3599size_t nr;3600enum ref_transaction_state state;3601};36023603struct ref_transaction *ref_transaction_begin(struct strbuf *err)3604{3605assert(err);36063607returnxcalloc(1,sizeof(struct ref_transaction));3608}36093610voidref_transaction_free(struct ref_transaction *transaction)3611{3612int i;36133614if(!transaction)3615return;36163617for(i =0; i < transaction->nr; i++) {3618free(transaction->updates[i]->msg);3619free(transaction->updates[i]);3620}3621free(transaction->updates);3622free(transaction);3623}36243625static struct ref_update *add_update(struct ref_transaction *transaction,3626const char*refname)3627{3628size_t len =strlen(refname);3629struct ref_update *update =xcalloc(1,sizeof(*update) + len +1);36303631strcpy((char*)update->refname, refname);3632ALLOC_GROW(transaction->updates, transaction->nr +1, transaction->alloc);3633 transaction->updates[transaction->nr++] = update;3634return update;3635}36363637intref_transaction_update(struct ref_transaction *transaction,3638const char*refname,3639const unsigned char*new_sha1,3640const unsigned char*old_sha1,3641int flags,int have_old,const char*msg,3642struct strbuf *err)3643{3644struct ref_update *update;36453646assert(err);36473648if(transaction->state != REF_TRANSACTION_OPEN)3649die("BUG: update called for transaction that is not open");36503651if(have_old && !old_sha1)3652die("BUG: have_old is true but old_sha1 is NULL");36533654if(!is_null_sha1(new_sha1) &&3655check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3656strbuf_addf(err,"refusing to update ref with bad name%s",3657 refname);3658return-1;3659}36603661 update =add_update(transaction, refname);3662hashcpy(update->new_sha1, new_sha1);3663 update->flags = flags;3664 update->have_old = have_old;3665if(have_old)3666hashcpy(update->old_sha1, old_sha1);3667if(msg)3668 update->msg =xstrdup(msg);3669return0;3670}36713672intref_transaction_create(struct ref_transaction *transaction,3673const char*refname,3674const unsigned char*new_sha1,3675int flags,const char*msg,3676struct strbuf *err)3677{3678returnref_transaction_update(transaction, refname, new_sha1,3679 null_sha1, flags,1, msg, err);3680}36813682intref_transaction_delete(struct ref_transaction *transaction,3683const char*refname,3684const unsigned char*old_sha1,3685int flags,int have_old,const char*msg,3686struct strbuf *err)3687{3688returnref_transaction_update(transaction, refname, null_sha1,3689 old_sha1, flags, have_old, msg, err);3690}36913692intupdate_ref(const char*action,const char*refname,3693const unsigned char*sha1,const unsigned char*oldval,3694int flags,enum action_on_err onerr)3695{3696struct ref_transaction *t;3697struct strbuf err = STRBUF_INIT;36983699 t =ref_transaction_begin(&err);3700if(!t ||3701ref_transaction_update(t, refname, sha1, oldval, flags,3702!!oldval, action, &err) ||3703ref_transaction_commit(t, &err)) {3704const char*str ="update_ref failed for ref '%s':%s";37053706ref_transaction_free(t);3707switch(onerr) {3708case UPDATE_REFS_MSG_ON_ERR:3709error(str, refname, err.buf);3710break;3711case UPDATE_REFS_DIE_ON_ERR:3712die(str, refname, err.buf);3713break;3714case UPDATE_REFS_QUIET_ON_ERR:3715break;3716}3717strbuf_release(&err);3718return1;3719}3720strbuf_release(&err);3721ref_transaction_free(t);3722return0;3723}37243725static intref_update_compare(const void*r1,const void*r2)3726{3727const struct ref_update *const*u1 = r1;3728const struct ref_update *const*u2 = r2;3729returnstrcmp((*u1)->refname, (*u2)->refname);3730}37313732static intref_update_reject_duplicates(struct ref_update **updates,int n,3733struct strbuf *err)3734{3735int i;37363737assert(err);37383739for(i =1; i < n; i++)3740if(!strcmp(updates[i -1]->refname, updates[i]->refname)) {3741strbuf_addf(err,3742"Multiple updates for ref '%s' not allowed.",3743 updates[i]->refname);3744return1;3745}3746return0;3747}37483749intref_transaction_commit(struct ref_transaction *transaction,3750struct strbuf *err)3751{3752int ret =0, i;3753int n = transaction->nr;3754struct ref_update **updates = transaction->updates;3755struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3756struct string_list_item *ref_to_delete;37573758assert(err);37593760if(transaction->state != REF_TRANSACTION_OPEN)3761die("BUG: commit called for transaction that is not open");37623763if(!n) {3764 transaction->state = REF_TRANSACTION_CLOSED;3765return0;3766}37673768/* Copy, sort, and reject duplicate refs */3769qsort(updates, n,sizeof(*updates), ref_update_compare);3770if(ref_update_reject_duplicates(updates, n, err)) {3771 ret = TRANSACTION_GENERIC_ERROR;3772goto cleanup;3773}37743775/* Acquire all locks while verifying old values */3776for(i =0; i < n; i++) {3777struct ref_update *update = updates[i];3778int flags = update->flags;37793780if(is_null_sha1(update->new_sha1))3781 flags |= REF_DELETING;3782 update->lock =lock_ref_sha1_basic(update->refname,3783(update->have_old ?3784 update->old_sha1 :3785 NULL),3786 NULL,3787 flags,3788&update->type);3789if(!update->lock) {3790 ret = (errno == ENOTDIR)3791? TRANSACTION_NAME_CONFLICT3792: TRANSACTION_GENERIC_ERROR;3793strbuf_addf(err,"Cannot lock the ref '%s'.",3794 update->refname);3795goto cleanup;3796}3797}37983799/* Perform updates first so live commits remain referenced */3800for(i =0; i < n; i++) {3801struct ref_update *update = updates[i];38023803if(!is_null_sha1(update->new_sha1)) {3804if(write_ref_sha1(update->lock, update->new_sha1,3805 update->msg)) {3806 update->lock = NULL;/* freed by write_ref_sha1 */3807strbuf_addf(err,"Cannot update the ref '%s'.",3808 update->refname);3809 ret = TRANSACTION_GENERIC_ERROR;3810goto cleanup;3811}3812 update->lock = NULL;/* freed by write_ref_sha1 */3813}3814}38153816/* Perform deletes now that updates are safely completed */3817for(i =0; i < n; i++) {3818struct ref_update *update = updates[i];38193820if(update->lock) {3821if(delete_ref_loose(update->lock, update->type, err)) {3822 ret = TRANSACTION_GENERIC_ERROR;3823goto cleanup;3824}38253826if(!(update->flags & REF_ISPRUNING))3827string_list_append(&refs_to_delete,3828 update->lock->ref_name);3829}3830}38313832if(repack_without_refs(&refs_to_delete, err)) {3833 ret = TRANSACTION_GENERIC_ERROR;3834goto cleanup;3835}3836for_each_string_list_item(ref_to_delete, &refs_to_delete)3837unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3838clear_loose_ref_cache(&ref_cache);38393840cleanup:3841 transaction->state = REF_TRANSACTION_CLOSED;38423843for(i =0; i < n; i++)3844if(updates[i]->lock)3845unlock_ref(updates[i]->lock);3846string_list_clear(&refs_to_delete,0);3847return ret;3848}38493850char*shorten_unambiguous_ref(const char*refname,int strict)3851{3852int i;3853static char**scanf_fmts;3854static int nr_rules;3855char*short_name;38563857if(!nr_rules) {3858/*3859 * Pre-generate scanf formats from ref_rev_parse_rules[].3860 * Generate a format suitable for scanf from a3861 * ref_rev_parse_rules rule by interpolating "%s" at the3862 * location of the "%.*s".3863 */3864size_t total_len =0;3865size_t offset =0;38663867/* the rule list is NULL terminated, count them first */3868for(nr_rules =0; ref_rev_parse_rules[nr_rules]; nr_rules++)3869/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3870 total_len +=strlen(ref_rev_parse_rules[nr_rules]) -2+1;38713872 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);38733874 offset =0;3875for(i =0; i < nr_rules; i++) {3876assert(offset < total_len);3877 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules] + offset;3878 offset +=snprintf(scanf_fmts[i], total_len - offset,3879 ref_rev_parse_rules[i],2,"%s") +1;3880}3881}38823883/* bail out if there are no rules */3884if(!nr_rules)3885returnxstrdup(refname);38863887/* buffer for scanf result, at most refname must fit */3888 short_name =xstrdup(refname);38893890/* skip first rule, it will always match */3891for(i = nr_rules -1; i >0; --i) {3892int j;3893int rules_to_fail = i;3894int short_name_len;38953896if(1!=sscanf(refname, scanf_fmts[i], short_name))3897continue;38983899 short_name_len =strlen(short_name);39003901/*3902 * in strict mode, all (except the matched one) rules3903 * must fail to resolve to a valid non-ambiguous ref3904 */3905if(strict)3906 rules_to_fail = nr_rules;39073908/*3909 * check if the short name resolves to a valid ref,3910 * but use only rules prior to the matched one3911 */3912for(j =0; j < rules_to_fail; j++) {3913const char*rule = ref_rev_parse_rules[j];3914char refname[PATH_MAX];39153916/* skip matched rule */3917if(i == j)3918continue;39193920/*3921 * the short name is ambiguous, if it resolves3922 * (with this previous rule) to a valid ref3923 * read_ref() returns 0 on success3924 */3925mksnpath(refname,sizeof(refname),3926 rule, short_name_len, short_name);3927if(ref_exists(refname))3928break;3929}39303931/*3932 * short name is non-ambiguous if all previous rules3933 * haven't resolved to a valid ref3934 */3935if(j == rules_to_fail)3936return short_name;3937}39383939free(short_name);3940returnxstrdup(refname);3941}39423943static struct string_list *hide_refs;39443945intparse_hide_refs_config(const char*var,const char*value,const char*section)3946{3947if(!strcmp("transfer.hiderefs", var) ||3948/* NEEDSWORK: use parse_config_key() once both are merged */3949(starts_with(var, section) && var[strlen(section)] =='.'&&3950!strcmp(var +strlen(section),".hiderefs"))) {3951char*ref;3952int len;39533954if(!value)3955returnconfig_error_nonbool(var);3956 ref =xstrdup(value);3957 len =strlen(ref);3958while(len && ref[len -1] =='/')3959 ref[--len] ='\0';3960if(!hide_refs) {3961 hide_refs =xcalloc(1,sizeof(*hide_refs));3962 hide_refs->strdup_strings =1;3963}3964string_list_append(hide_refs, ref);3965}3966return0;3967}39683969intref_is_hidden(const char*refname)3970{3971struct string_list_item *item;39723973if(!hide_refs)3974return0;3975for_each_string_list_item(item, hide_refs) {3976int len;3977if(!starts_with(refname, item->string))3978continue;3979 len =strlen(item->string);3980if(!refname[len] || refname[len] =='/')3981return1;3982}3983return0;3984}39853986struct expire_reflog_cb {3987unsigned int flags;3988 reflog_expiry_should_prune_fn *should_prune_fn;3989void*policy_cb;3990FILE*newlog;3991unsigned char last_kept_sha1[20];3992};39933994static intexpire_reflog_ent(unsigned char*osha1,unsigned char*nsha1,3995const char*email,unsigned long timestamp,int tz,3996const char*message,void*cb_data)3997{3998struct expire_reflog_cb *cb = cb_data;3999struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;40004001if(cb->flags & EXPIRE_REFLOGS_REWRITE)4002 osha1 = cb->last_kept_sha1;40034004if((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,4005 message, policy_cb)) {4006if(!cb->newlog)4007printf("would prune%s", message);4008else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)4009printf("prune%s", message);4010}else{4011if(cb->newlog) {4012fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",4013sha1_to_hex(osha1),sha1_to_hex(nsha1),4014 email, timestamp, tz, message);4015hashcpy(cb->last_kept_sha1, nsha1);4016}4017if(cb->flags & EXPIRE_REFLOGS_VERBOSE)4018printf("keep%s", message);4019}4020return0;4021}40224023intreflog_expire(const char*refname,const unsigned char*sha1,4024unsigned int flags,4025 reflog_expiry_prepare_fn prepare_fn,4026 reflog_expiry_should_prune_fn should_prune_fn,4027 reflog_expiry_cleanup_fn cleanup_fn,4028void*policy_cb_data)4029{4030static struct lock_file reflog_lock;4031struct expire_reflog_cb cb;4032struct ref_lock *lock;4033char*log_file;4034int status =0;40354036memset(&cb,0,sizeof(cb));4037 cb.flags = flags;4038 cb.policy_cb = policy_cb_data;4039 cb.should_prune_fn = should_prune_fn;40404041/*4042 * The reflog file is locked by holding the lock on the4043 * reference itself, plus we might need to update the4044 * reference if --updateref was specified:4045 */4046 lock =lock_ref_sha1_basic(refname, sha1, NULL,0, NULL);4047if(!lock)4048returnerror("cannot lock ref '%s'", refname);4049if(!reflog_exists(refname)) {4050unlock_ref(lock);4051return0;4052}40534054 log_file =git_pathdup("logs/%s", refname);4055if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4056/*4057 * Even though holding $GIT_DIR/logs/$reflog.lock has4058 * no locking implications, we use the lock_file4059 * machinery here anyway because it does a lot of the4060 * work we need, including cleaning up if the program4061 * exits unexpectedly.4062 */4063if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4064struct strbuf err = STRBUF_INIT;4065unable_to_lock_message(log_file, errno, &err);4066error("%s", err.buf);4067strbuf_release(&err);4068goto failure;4069}4070 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4071if(!cb.newlog) {4072error("cannot fdopen%s(%s)",4073 reflog_lock.filename.buf,strerror(errno));4074goto failure;4075}4076}40774078(*prepare_fn)(refname, sha1, cb.policy_cb);4079for_each_reflog_ent(refname, expire_reflog_ent, &cb);4080(*cleanup_fn)(cb.policy_cb);40814082if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4083if(close_lock_file(&reflog_lock)) {4084 status |=error("couldn't write%s:%s", log_file,4085strerror(errno));4086}else if((flags & EXPIRE_REFLOGS_UPDATE_REF) &&4087(write_in_full(lock->lock_fd,4088sha1_to_hex(cb.last_kept_sha1),40) !=40||4089write_str_in_full(lock->lock_fd,"\n") !=1||4090close_ref(lock) <0)) {4091 status |=error("couldn't write%s",4092 lock->lk->filename.buf);4093rollback_lock_file(&reflog_lock);4094}else if(commit_lock_file(&reflog_lock)) {4095 status |=error("unable to commit reflog '%s' (%s)",4096 log_file,strerror(errno));4097}else if((flags & EXPIRE_REFLOGS_UPDATE_REF) &&commit_ref(lock)) {4098 status |=error("couldn't set%s", lock->ref_name);4099}4100}4101free(log_file);4102unlock_ref(lock);4103return status;41044105 failure:4106rollback_lock_file(&reflog_lock);4107free(log_file);4108unlock_ref(lock);4109return-1;4110}