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 9/* 10 * How to handle various characters in refnames: 11 * 0: An acceptable character for refs 12 * 1: End-of-component 13 * 2: ., look for a preceding . to reject .. in refs 14 * 3: {, look for a preceding @ to reject @{ in refs 15 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP 16 */ 17static unsigned char refname_disposition[256] = { 181,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 194,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 204,0,0,0,0,0,0,0,0,0,4,0,0,0,2,1, 210,0,0,0,0,0,0,0,0,0,4,0,0,0,0,4, 220,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 230,0,0,0,0,0,0,0,0,0,0,4,4,0,4,0, 240,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 250,0,0,0,0,0,0,0,0,0,0,3,0,0,4,4 26}; 27 28/* 29 * Used as a flag to ref_transaction_delete when a loose ref is being 30 * pruned. 31 */ 32#define REF_ISPRUNING 0x0100 33/* 34 * Try to read one refname component from the front of refname. 35 * Return the length of the component found, or -1 if the component is 36 * not legal. It is legal if it is something reasonable to have under 37 * ".git/refs/"; We do not like it if: 38 * 39 * - any path component of it begins with ".", or 40 * - it has double dots "..", or 41 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 42 * - it ends with a "/". 43 * - it ends with ".lock" 44 * - it contains a "\" (backslash) 45 */ 46static intcheck_refname_component(const char*refname,int flags) 47{ 48const char*cp; 49char last ='\0'; 50 51for(cp = refname; ; cp++) { 52int ch = *cp &255; 53unsigned char disp = refname_disposition[ch]; 54switch(disp) { 55case1: 56goto out; 57case2: 58if(last =='.') 59return-1;/* Refname contains "..". */ 60break; 61case3: 62if(last =='@') 63return-1;/* Refname contains "@{". */ 64break; 65case4: 66return-1; 67} 68 last = ch; 69} 70out: 71if(cp == refname) 72return0;/* Component has zero length. */ 73if(refname[0] =='.') 74return-1;/* Component starts with '.'. */ 75if(cp - refname >= LOCK_SUFFIX_LEN && 76!memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) 77return-1;/* Refname ends with ".lock". */ 78return cp - refname; 79} 80 81intcheck_refname_format(const char*refname,int flags) 82{ 83int component_len, component_count =0; 84 85if(!strcmp(refname,"@")) 86/* Refname is a single character '@'. */ 87return-1; 88 89while(1) { 90/* We are at the start of a path component. */ 91 component_len =check_refname_component(refname, flags); 92if(component_len <=0) { 93if((flags & REFNAME_REFSPEC_PATTERN) && 94 refname[0] =='*'&& 95(refname[1] =='\0'|| refname[1] =='/')) { 96/* Accept one wildcard as a full refname component. */ 97 flags &= ~REFNAME_REFSPEC_PATTERN; 98 component_len =1; 99}else{ 100return-1; 101} 102} 103 component_count++; 104if(refname[component_len] =='\0') 105break; 106/* Skip to next component. */ 107 refname += component_len +1; 108} 109 110if(refname[component_len -1] =='.') 111return-1;/* Refname ends with '.'. */ 112if(!(flags & REFNAME_ALLOW_ONELEVEL) && component_count <2) 113return-1;/* Refname has only one component. */ 114return0; 115} 116 117struct ref_entry; 118 119/* 120 * Information used (along with the information in ref_entry) to 121 * describe a single cached reference. This data structure only 122 * occurs embedded in a union in struct ref_entry, and only when 123 * (ref_entry->flag & REF_DIR) is zero. 124 */ 125struct ref_value { 126/* 127 * The name of the object to which this reference resolves 128 * (which may be a tag object). If REF_ISBROKEN, this is 129 * null. If REF_ISSYMREF, then this is the name of the object 130 * referred to by the last reference in the symlink chain. 131 */ 132unsigned char sha1[20]; 133 134/* 135 * If REF_KNOWS_PEELED, then this field holds the peeled value 136 * of this reference, or null if the reference is known not to 137 * be peelable. See the documentation for peel_ref() for an 138 * exact definition of "peelable". 139 */ 140unsigned char peeled[20]; 141}; 142 143struct ref_cache; 144 145/* 146 * Information used (along with the information in ref_entry) to 147 * describe a level in the hierarchy of references. This data 148 * structure only occurs embedded in a union in struct ref_entry, and 149 * only when (ref_entry.flag & REF_DIR) is set. In that case, 150 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 151 * in the directory have already been read: 152 * 153 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 154 * or packed references, already read. 155 * 156 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 157 * references that hasn't been read yet (nor has any of its 158 * subdirectories). 159 * 160 * Entries within a directory are stored within a growable array of 161 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 162 * sorted are sorted by their component name in strcmp() order and the 163 * remaining entries are unsorted. 164 * 165 * Loose references are read lazily, one directory at a time. When a 166 * directory of loose references is read, then all of the references 167 * in that directory are stored, and REF_INCOMPLETE stubs are created 168 * for any subdirectories, but the subdirectories themselves are not 169 * read. The reading is triggered by get_ref_dir(). 170 */ 171struct ref_dir { 172int nr, alloc; 173 174/* 175 * Entries with index 0 <= i < sorted are sorted by name. New 176 * entries are appended to the list unsorted, and are sorted 177 * only when required; thus we avoid the need to sort the list 178 * after the addition of every reference. 179 */ 180int sorted; 181 182/* A pointer to the ref_cache that contains this ref_dir. */ 183struct ref_cache *ref_cache; 184 185struct ref_entry **entries; 186}; 187 188/* 189 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 190 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 191 * public values; see refs.h. 192 */ 193 194/* 195 * The field ref_entry->u.value.peeled of this value entry contains 196 * the correct peeled value for the reference, which might be 197 * null_sha1 if the reference is not a tag or if it is broken. 198 */ 199#define REF_KNOWS_PEELED 0x10 200 201/* ref_entry represents a directory of references */ 202#define REF_DIR 0x20 203 204/* 205 * Entry has not yet been read from disk (used only for REF_DIR 206 * entries representing loose references) 207 */ 208#define REF_INCOMPLETE 0x40 209 210/* 211 * A ref_entry represents either a reference or a "subdirectory" of 212 * references. 213 * 214 * Each directory in the reference namespace is represented by a 215 * ref_entry with (flags & REF_DIR) set and containing a subdir member 216 * that holds the entries in that directory that have been read so 217 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 218 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 219 * used for loose reference directories. 220 * 221 * References are represented by a ref_entry with (flags & REF_DIR) 222 * unset and a value member that describes the reference's value. The 223 * flag member is at the ref_entry level, but it is also needed to 224 * interpret the contents of the value field (in other words, a 225 * ref_value object is not very much use without the enclosing 226 * ref_entry). 227 * 228 * Reference names cannot end with slash and directories' names are 229 * always stored with a trailing slash (except for the top-level 230 * directory, which is always denoted by ""). This has two nice 231 * consequences: (1) when the entries in each subdir are sorted 232 * lexicographically by name (as they usually are), the references in 233 * a whole tree can be generated in lexicographic order by traversing 234 * the tree in left-to-right, depth-first order; (2) the names of 235 * references and subdirectories cannot conflict, and therefore the 236 * presence of an empty subdirectory does not block the creation of a 237 * similarly-named reference. (The fact that reference names with the 238 * same leading components can conflict *with each other* is a 239 * separate issue that is regulated by is_refname_available().) 240 * 241 * Please note that the name field contains the fully-qualified 242 * reference (or subdirectory) name. Space could be saved by only 243 * storing the relative names. But that would require the full names 244 * to be generated on the fly when iterating in do_for_each_ref(), and 245 * would break callback functions, who have always been able to assume 246 * that the name strings that they are passed will not be freed during 247 * the iteration. 248 */ 249struct ref_entry { 250unsigned char flag;/* ISSYMREF? ISPACKED? */ 251union{ 252struct ref_value value;/* if not (flags&REF_DIR) */ 253struct ref_dir subdir;/* if (flags&REF_DIR) */ 254} u; 255/* 256 * The full name of the reference (e.g., "refs/heads/master") 257 * or the full name of the directory with a trailing slash 258 * (e.g., "refs/heads/"): 259 */ 260char name[FLEX_ARRAY]; 261}; 262 263static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 264 265static struct ref_dir *get_ref_dir(struct ref_entry *entry) 266{ 267struct ref_dir *dir; 268assert(entry->flag & REF_DIR); 269 dir = &entry->u.subdir; 270if(entry->flag & REF_INCOMPLETE) { 271read_loose_refs(entry->name, dir); 272 entry->flag &= ~REF_INCOMPLETE; 273} 274return dir; 275} 276 277/* 278 * Check if a refname is safe. 279 * For refs that start with "refs/" we consider it safe as long they do 280 * not try to resolve to outside of refs/. 281 * 282 * For all other refs we only consider them safe iff they only contain 283 * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like 284 * "config"). 285 */ 286static intrefname_is_safe(const char*refname) 287{ 288if(starts_with(refname,"refs/")) { 289char*buf; 290int result; 291 292 buf =xmalloc(strlen(refname) +1); 293/* 294 * Does the refname try to escape refs/? 295 * For example: refs/foo/../bar is safe but refs/foo/../../bar 296 * is not. 297 */ 298 result = !normalize_path_copy(buf, refname +strlen("refs/")); 299free(buf); 300return result; 301} 302while(*refname) { 303if(!isupper(*refname) && *refname !='_') 304return0; 305 refname++; 306} 307return1; 308} 309 310static struct ref_entry *create_ref_entry(const char*refname, 311const unsigned char*sha1,int flag, 312int check_name) 313{ 314int len; 315struct ref_entry *ref; 316 317if(check_name && 318check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 319die("Reference has invalid format: '%s'", refname); 320if(!check_name && !refname_is_safe(refname)) 321die("Reference has invalid name: '%s'", refname); 322 len =strlen(refname) +1; 323 ref =xmalloc(sizeof(struct ref_entry) + len); 324hashcpy(ref->u.value.sha1, sha1); 325hashclr(ref->u.value.peeled); 326memcpy(ref->name, refname, len); 327 ref->flag = flag; 328return ref; 329} 330 331static voidclear_ref_dir(struct ref_dir *dir); 332 333static voidfree_ref_entry(struct ref_entry *entry) 334{ 335if(entry->flag & REF_DIR) { 336/* 337 * Do not use get_ref_dir() here, as that might 338 * trigger the reading of loose refs. 339 */ 340clear_ref_dir(&entry->u.subdir); 341} 342free(entry); 343} 344 345/* 346 * Add a ref_entry to the end of dir (unsorted). Entry is always 347 * stored directly in dir; no recursion into subdirectories is 348 * done. 349 */ 350static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 351{ 352ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 353 dir->entries[dir->nr++] = entry; 354/* optimize for the case that entries are added in order */ 355if(dir->nr ==1|| 356(dir->nr == dir->sorted +1&& 357strcmp(dir->entries[dir->nr -2]->name, 358 dir->entries[dir->nr -1]->name) <0)) 359 dir->sorted = dir->nr; 360} 361 362/* 363 * Clear and free all entries in dir, recursively. 364 */ 365static voidclear_ref_dir(struct ref_dir *dir) 366{ 367int i; 368for(i =0; i < dir->nr; i++) 369free_ref_entry(dir->entries[i]); 370free(dir->entries); 371 dir->sorted = dir->nr = dir->alloc =0; 372 dir->entries = NULL; 373} 374 375/* 376 * Create a struct ref_entry object for the specified dirname. 377 * dirname is the name of the directory with a trailing slash (e.g., 378 * "refs/heads/") or "" for the top-level directory. 379 */ 380static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 381const char*dirname,size_t len, 382int incomplete) 383{ 384struct ref_entry *direntry; 385 direntry =xcalloc(1,sizeof(struct ref_entry) + len +1); 386memcpy(direntry->name, dirname, len); 387 direntry->name[len] ='\0'; 388 direntry->u.subdir.ref_cache = ref_cache; 389 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 390return direntry; 391} 392 393static intref_entry_cmp(const void*a,const void*b) 394{ 395struct ref_entry *one = *(struct ref_entry **)a; 396struct ref_entry *two = *(struct ref_entry **)b; 397returnstrcmp(one->name, two->name); 398} 399 400static voidsort_ref_dir(struct ref_dir *dir); 401 402struct string_slice { 403size_t len; 404const char*str; 405}; 406 407static intref_entry_cmp_sslice(const void*key_,const void*ent_) 408{ 409const struct string_slice *key = key_; 410const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 411int cmp =strncmp(key->str, ent->name, key->len); 412if(cmp) 413return cmp; 414return'\0'- (unsigned char)ent->name[key->len]; 415} 416 417/* 418 * Return the index of the entry with the given refname from the 419 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 420 * no such entry is found. dir must already be complete. 421 */ 422static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 423{ 424struct ref_entry **r; 425struct string_slice key; 426 427if(refname == NULL || !dir->nr) 428return-1; 429 430sort_ref_dir(dir); 431 key.len = len; 432 key.str = refname; 433 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 434 ref_entry_cmp_sslice); 435 436if(r == NULL) 437return-1; 438 439return r - dir->entries; 440} 441 442/* 443 * Search for a directory entry directly within dir (without 444 * recursing). Sort dir if necessary. subdirname must be a directory 445 * name (i.e., end in '/'). If mkdir is set, then create the 446 * directory if it is missing; otherwise, return NULL if the desired 447 * directory cannot be found. dir must already be complete. 448 */ 449static struct ref_dir *search_for_subdir(struct ref_dir *dir, 450const char*subdirname,size_t len, 451int mkdir) 452{ 453int entry_index =search_ref_dir(dir, subdirname, len); 454struct ref_entry *entry; 455if(entry_index == -1) { 456if(!mkdir) 457return NULL; 458/* 459 * Since dir is complete, the absence of a subdir 460 * means that the subdir really doesn't exist; 461 * therefore, create an empty record for it but mark 462 * the record complete. 463 */ 464 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 465add_entry_to_dir(dir, entry); 466}else{ 467 entry = dir->entries[entry_index]; 468} 469returnget_ref_dir(entry); 470} 471 472/* 473 * If refname is a reference name, find the ref_dir within the dir 474 * tree that should hold refname. If refname is a directory name 475 * (i.e., ends in '/'), then return that ref_dir itself. dir must 476 * represent the top-level directory and must already be complete. 477 * Sort ref_dirs and recurse into subdirectories as necessary. If 478 * mkdir is set, then create any missing directories; otherwise, 479 * return NULL if the desired directory cannot be found. 480 */ 481static struct ref_dir *find_containing_dir(struct ref_dir *dir, 482const char*refname,int mkdir) 483{ 484const char*slash; 485for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 486size_t dirnamelen = slash - refname +1; 487struct ref_dir *subdir; 488 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 489if(!subdir) { 490 dir = NULL; 491break; 492} 493 dir = subdir; 494} 495 496return dir; 497} 498 499/* 500 * Find the value entry with the given name in dir, sorting ref_dirs 501 * and recursing into subdirectories as necessary. If the name is not 502 * found or it corresponds to a directory entry, return NULL. 503 */ 504static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 505{ 506int entry_index; 507struct ref_entry *entry; 508 dir =find_containing_dir(dir, refname,0); 509if(!dir) 510return NULL; 511 entry_index =search_ref_dir(dir, refname,strlen(refname)); 512if(entry_index == -1) 513return NULL; 514 entry = dir->entries[entry_index]; 515return(entry->flag & REF_DIR) ? NULL : entry; 516} 517 518/* 519 * Remove the entry with the given name from dir, recursing into 520 * subdirectories as necessary. If refname is the name of a directory 521 * (i.e., ends with '/'), then remove the directory and its contents. 522 * If the removal was successful, return the number of entries 523 * remaining in the directory entry that contained the deleted entry. 524 * If the name was not found, return -1. Please note that this 525 * function only deletes the entry from the cache; it does not delete 526 * it from the filesystem or ensure that other cache entries (which 527 * might be symbolic references to the removed entry) are updated. 528 * Nor does it remove any containing dir entries that might be made 529 * empty by the removal. dir must represent the top-level directory 530 * and must already be complete. 531 */ 532static intremove_entry(struct ref_dir *dir,const char*refname) 533{ 534int refname_len =strlen(refname); 535int entry_index; 536struct ref_entry *entry; 537int is_dir = refname[refname_len -1] =='/'; 538if(is_dir) { 539/* 540 * refname represents a reference directory. Remove 541 * the trailing slash; otherwise we will get the 542 * directory *representing* refname rather than the 543 * one *containing* it. 544 */ 545char*dirname =xmemdupz(refname, refname_len -1); 546 dir =find_containing_dir(dir, dirname,0); 547free(dirname); 548}else{ 549 dir =find_containing_dir(dir, refname,0); 550} 551if(!dir) 552return-1; 553 entry_index =search_ref_dir(dir, refname, refname_len); 554if(entry_index == -1) 555return-1; 556 entry = dir->entries[entry_index]; 557 558memmove(&dir->entries[entry_index], 559&dir->entries[entry_index +1], 560(dir->nr - entry_index -1) *sizeof(*dir->entries) 561); 562 dir->nr--; 563if(dir->sorted > entry_index) 564 dir->sorted--; 565free_ref_entry(entry); 566return dir->nr; 567} 568 569/* 570 * Add a ref_entry to the ref_dir (unsorted), recursing into 571 * subdirectories as necessary. dir must represent the top-level 572 * directory. Return 0 on success. 573 */ 574static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 575{ 576 dir =find_containing_dir(dir, ref->name,1); 577if(!dir) 578return-1; 579add_entry_to_dir(dir, ref); 580return0; 581} 582 583/* 584 * Emit a warning and return true iff ref1 and ref2 have the same name 585 * and the same sha1. Die if they have the same name but different 586 * sha1s. 587 */ 588static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 589{ 590if(strcmp(ref1->name, ref2->name)) 591return0; 592 593/* Duplicate name; make sure that they don't conflict: */ 594 595if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 596/* This is impossible by construction */ 597die("Reference directory conflict:%s", ref1->name); 598 599if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 600die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 601 602warning("Duplicated ref:%s", ref1->name); 603return1; 604} 605 606/* 607 * Sort the entries in dir non-recursively (if they are not already 608 * sorted) and remove any duplicate entries. 609 */ 610static voidsort_ref_dir(struct ref_dir *dir) 611{ 612int i, j; 613struct ref_entry *last = NULL; 614 615/* 616 * This check also prevents passing a zero-length array to qsort(), 617 * which is a problem on some platforms. 618 */ 619if(dir->sorted == dir->nr) 620return; 621 622qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 623 624/* Remove any duplicates: */ 625for(i =0, j =0; j < dir->nr; j++) { 626struct ref_entry *entry = dir->entries[j]; 627if(last &&is_dup_ref(last, entry)) 628free_ref_entry(entry); 629else 630 last = dir->entries[i++] = entry; 631} 632 dir->sorted = dir->nr = i; 633} 634 635/* Include broken references in a do_for_each_ref*() iteration: */ 636#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 637 638/* 639 * Return true iff the reference described by entry can be resolved to 640 * an object in the database. Emit a warning if the referred-to 641 * object does not exist. 642 */ 643static intref_resolves_to_object(struct ref_entry *entry) 644{ 645if(entry->flag & REF_ISBROKEN) 646return0; 647if(!has_sha1_file(entry->u.value.sha1)) { 648error("%sdoes not point to a valid object!", entry->name); 649return0; 650} 651return1; 652} 653 654/* 655 * current_ref is a performance hack: when iterating over references 656 * using the for_each_ref*() functions, current_ref is set to the 657 * current reference's entry before calling the callback function. If 658 * the callback function calls peel_ref(), then peel_ref() first 659 * checks whether the reference to be peeled is the current reference 660 * (it usually is) and if so, returns that reference's peeled version 661 * if it is available. This avoids a refname lookup in a common case. 662 */ 663static struct ref_entry *current_ref; 664 665typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 666 667struct ref_entry_cb { 668const char*base; 669int trim; 670int flags; 671 each_ref_fn *fn; 672void*cb_data; 673}; 674 675/* 676 * Handle one reference in a do_for_each_ref*()-style iteration, 677 * calling an each_ref_fn for each entry. 678 */ 679static intdo_one_ref(struct ref_entry *entry,void*cb_data) 680{ 681struct ref_entry_cb *data = cb_data; 682struct ref_entry *old_current_ref; 683int retval; 684 685if(!starts_with(entry->name, data->base)) 686return0; 687 688if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 689!ref_resolves_to_object(entry)) 690return0; 691 692/* Store the old value, in case this is a recursive call: */ 693 old_current_ref = current_ref; 694 current_ref = entry; 695 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 696 entry->flag, data->cb_data); 697 current_ref = old_current_ref; 698return retval; 699} 700 701/* 702 * Call fn for each reference in dir that has index in the range 703 * offset <= index < dir->nr. Recurse into subdirectories that are in 704 * that index range, sorting them before iterating. This function 705 * does not sort dir itself; it should be sorted beforehand. fn is 706 * called for all references, including broken ones. 707 */ 708static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 709 each_ref_entry_fn fn,void*cb_data) 710{ 711int i; 712assert(dir->sorted == dir->nr); 713for(i = offset; i < dir->nr; i++) { 714struct ref_entry *entry = dir->entries[i]; 715int retval; 716if(entry->flag & REF_DIR) { 717struct ref_dir *subdir =get_ref_dir(entry); 718sort_ref_dir(subdir); 719 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 720}else{ 721 retval =fn(entry, cb_data); 722} 723if(retval) 724return retval; 725} 726return0; 727} 728 729/* 730 * Call fn for each reference in the union of dir1 and dir2, in order 731 * by refname. Recurse into subdirectories. If a value entry appears 732 * in both dir1 and dir2, then only process the version that is in 733 * dir2. The input dirs must already be sorted, but subdirs will be 734 * sorted as needed. fn is called for all references, including 735 * broken ones. 736 */ 737static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 738struct ref_dir *dir2, 739 each_ref_entry_fn fn,void*cb_data) 740{ 741int retval; 742int i1 =0, i2 =0; 743 744assert(dir1->sorted == dir1->nr); 745assert(dir2->sorted == dir2->nr); 746while(1) { 747struct ref_entry *e1, *e2; 748int cmp; 749if(i1 == dir1->nr) { 750returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 751} 752if(i2 == dir2->nr) { 753returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 754} 755 e1 = dir1->entries[i1]; 756 e2 = dir2->entries[i2]; 757 cmp =strcmp(e1->name, e2->name); 758if(cmp ==0) { 759if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 760/* Both are directories; descend them in parallel. */ 761struct ref_dir *subdir1 =get_ref_dir(e1); 762struct ref_dir *subdir2 =get_ref_dir(e2); 763sort_ref_dir(subdir1); 764sort_ref_dir(subdir2); 765 retval =do_for_each_entry_in_dirs( 766 subdir1, subdir2, fn, cb_data); 767 i1++; 768 i2++; 769}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 770/* Both are references; ignore the one from dir1. */ 771 retval =fn(e2, cb_data); 772 i1++; 773 i2++; 774}else{ 775die("conflict between reference and directory:%s", 776 e1->name); 777} 778}else{ 779struct ref_entry *e; 780if(cmp <0) { 781 e = e1; 782 i1++; 783}else{ 784 e = e2; 785 i2++; 786} 787if(e->flag & REF_DIR) { 788struct ref_dir *subdir =get_ref_dir(e); 789sort_ref_dir(subdir); 790 retval =do_for_each_entry_in_dir( 791 subdir,0, fn, cb_data); 792}else{ 793 retval =fn(e, cb_data); 794} 795} 796if(retval) 797return retval; 798} 799} 800 801/* 802 * Load all of the refs from the dir into our in-memory cache. The hard work 803 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 804 * through all of the sub-directories. We do not even need to care about 805 * sorting, as traversal order does not matter to us. 806 */ 807static voidprime_ref_dir(struct ref_dir *dir) 808{ 809int i; 810for(i =0; i < dir->nr; i++) { 811struct ref_entry *entry = dir->entries[i]; 812if(entry->flag & REF_DIR) 813prime_ref_dir(get_ref_dir(entry)); 814} 815} 816 817static intentry_matches(struct ref_entry *entry,const struct string_list *list) 818{ 819return list &&string_list_has_string(list, entry->name); 820} 821 822struct nonmatching_ref_data { 823const struct string_list *skip; 824struct ref_entry *found; 825}; 826 827static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 828{ 829struct nonmatching_ref_data *data = vdata; 830 831if(entry_matches(entry, data->skip)) 832return0; 833 834 data->found = entry; 835return1; 836} 837 838static voidreport_refname_conflict(struct ref_entry *entry, 839const char*refname) 840{ 841error("'%s' exists; cannot create '%s'", entry->name, refname); 842} 843 844/* 845 * Return true iff a reference named refname could be created without 846 * conflicting with the name of an existing reference in dir. If 847 * skip is non-NULL, ignore potential conflicts with refs in skip 848 * (e.g., because they are scheduled for deletion in the same 849 * operation). 850 * 851 * Two reference names conflict if one of them exactly matches the 852 * leading components of the other; e.g., "foo/bar" conflicts with 853 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 854 * "foo/barbados". 855 * 856 * skip must be sorted. 857 */ 858static intis_refname_available(const char*refname, 859const struct string_list *skip, 860struct ref_dir *dir) 861{ 862const char*slash; 863size_t len; 864int pos; 865char*dirname; 866 867for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 868/* 869 * We are still at a leading dir of the refname; we are 870 * looking for a conflict with a leaf entry. 871 * 872 * If we find one, we still must make sure it is 873 * not in "skip". 874 */ 875 pos =search_ref_dir(dir, refname, slash - refname); 876if(pos >=0) { 877struct ref_entry *entry = dir->entries[pos]; 878if(entry_matches(entry, skip)) 879return1; 880report_refname_conflict(entry, refname); 881return0; 882} 883 884 885/* 886 * Otherwise, we can try to continue our search with 887 * the next component; if we come up empty, we know 888 * there is nothing under this whole prefix. 889 */ 890 pos =search_ref_dir(dir, refname, slash +1- refname); 891if(pos <0) 892return1; 893 894 dir =get_ref_dir(dir->entries[pos]); 895} 896 897/* 898 * We are at the leaf of our refname; we want to 899 * make sure there are no directories which match it. 900 */ 901 len =strlen(refname); 902 dirname =xmallocz(len +1); 903sprintf(dirname,"%s/", refname); 904 pos =search_ref_dir(dir, dirname, len +1); 905free(dirname); 906 907if(pos >=0) { 908/* 909 * We found a directory named "refname". It is a 910 * problem iff it contains any ref that is not 911 * in "skip". 912 */ 913struct ref_entry *entry = dir->entries[pos]; 914struct ref_dir *dir =get_ref_dir(entry); 915struct nonmatching_ref_data data; 916 917 data.skip = skip; 918sort_ref_dir(dir); 919if(!do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) 920return1; 921 922report_refname_conflict(data.found, refname); 923return0; 924} 925 926/* 927 * There is no point in searching for another leaf 928 * node which matches it; such an entry would be the 929 * ref we are looking for, not a conflict. 930 */ 931return1; 932} 933 934struct packed_ref_cache { 935struct ref_entry *root; 936 937/* 938 * Count of references to the data structure in this instance, 939 * including the pointer from ref_cache::packed if any. The 940 * data will not be freed as long as the reference count is 941 * nonzero. 942 */ 943unsigned int referrers; 944 945/* 946 * Iff the packed-refs file associated with this instance is 947 * currently locked for writing, this points at the associated 948 * lock (which is owned by somebody else). The referrer count 949 * is also incremented when the file is locked and decremented 950 * when it is unlocked. 951 */ 952struct lock_file *lock; 953 954/* The metadata from when this packed-refs cache was read */ 955struct stat_validity validity; 956}; 957 958/* 959 * Future: need to be in "struct repository" 960 * when doing a full libification. 961 */ 962static struct ref_cache { 963struct ref_cache *next; 964struct ref_entry *loose; 965struct packed_ref_cache *packed; 966/* 967 * The submodule name, or "" for the main repo. We allocate 968 * length 1 rather than FLEX_ARRAY so that the main ref_cache 969 * is initialized correctly. 970 */ 971char name[1]; 972} ref_cache, *submodule_ref_caches; 973 974/* Lock used for the main packed-refs file: */ 975static struct lock_file packlock; 976 977/* 978 * Increment the reference count of *packed_refs. 979 */ 980static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs) 981{ 982 packed_refs->referrers++; 983} 984 985/* 986 * Decrease the reference count of *packed_refs. If it goes to zero, 987 * free *packed_refs and return true; otherwise return false. 988 */ 989static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs) 990{ 991if(!--packed_refs->referrers) { 992free_ref_entry(packed_refs->root); 993stat_validity_clear(&packed_refs->validity); 994free(packed_refs); 995return1; 996}else{ 997return0; 998} 999}10001001static voidclear_packed_ref_cache(struct ref_cache *refs)1002{1003if(refs->packed) {1004struct packed_ref_cache *packed_refs = refs->packed;10051006if(packed_refs->lock)1007die("internal error: packed-ref cache cleared while locked");1008 refs->packed = NULL;1009release_packed_ref_cache(packed_refs);1010}1011}10121013static voidclear_loose_ref_cache(struct ref_cache *refs)1014{1015if(refs->loose) {1016free_ref_entry(refs->loose);1017 refs->loose = NULL;1018}1019}10201021static struct ref_cache *create_ref_cache(const char*submodule)1022{1023int len;1024struct ref_cache *refs;1025if(!submodule)1026 submodule ="";1027 len =strlen(submodule) +1;1028 refs =xcalloc(1,sizeof(struct ref_cache) + len);1029memcpy(refs->name, submodule, len);1030return refs;1031}10321033/*1034 * Return a pointer to a ref_cache for the specified submodule. For1035 * the main repository, use submodule==NULL. The returned structure1036 * will be allocated and initialized but not necessarily populated; it1037 * should not be freed.1038 */1039static struct ref_cache *get_ref_cache(const char*submodule)1040{1041struct ref_cache *refs;10421043if(!submodule || !*submodule)1044return&ref_cache;10451046for(refs = submodule_ref_caches; refs; refs = refs->next)1047if(!strcmp(submodule, refs->name))1048return refs;10491050 refs =create_ref_cache(submodule);1051 refs->next = submodule_ref_caches;1052 submodule_ref_caches = refs;1053return refs;1054}10551056/* The length of a peeled reference line in packed-refs, including EOL: */1057#define PEELED_LINE_LENGTH 4210581059/*1060 * The packed-refs header line that we write out. Perhaps other1061 * traits will be added later. The trailing space is required.1062 */1063static const char PACKED_REFS_HEADER[] =1064"# pack-refs with: peeled fully-peeled\n";10651066/*1067 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1068 * Return a pointer to the refname within the line (null-terminated),1069 * or NULL if there was a problem.1070 */1071static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1072{1073const char*ref;10741075/*1076 * 42: the answer to everything.1077 *1078 * In this case, it happens to be the answer to1079 * 40 (length of sha1 hex representation)1080 * +1 (space in between hex and name)1081 * +1 (newline at the end of the line)1082 */1083if(line->len <=42)1084return NULL;10851086if(get_sha1_hex(line->buf, sha1) <0)1087return NULL;1088if(!isspace(line->buf[40]))1089return NULL;10901091 ref = line->buf +41;1092if(isspace(*ref))1093return NULL;10941095if(line->buf[line->len -1] !='\n')1096return NULL;1097 line->buf[--line->len] =0;10981099return ref;1100}11011102/*1103 * Read f, which is a packed-refs file, into dir.1104 *1105 * A comment line of the form "# pack-refs with: " may contain zero or1106 * more traits. We interpret the traits as follows:1107 *1108 * No traits:1109 *1110 * Probably no references are peeled. But if the file contains a1111 * peeled value for a reference, we will use it.1112 *1113 * peeled:1114 *1115 * References under "refs/tags/", if they *can* be peeled, *are*1116 * peeled in this file. References outside of "refs/tags/" are1117 * probably not peeled even if they could have been, but if we find1118 * a peeled value for such a reference we will use it.1119 *1120 * fully-peeled:1121 *1122 * All references in the file that can be peeled are peeled.1123 * Inversely (and this is more important), any references in the1124 * file for which no peeled value is recorded is not peelable. This1125 * trait should typically be written alongside "peeled" for1126 * compatibility with older clients, but we do not require it1127 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1128 */1129static voidread_packed_refs(FILE*f,struct ref_dir *dir)1130{1131struct ref_entry *last = NULL;1132struct strbuf line = STRBUF_INIT;1133enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11341135while(strbuf_getwholeline(&line, f,'\n') != EOF) {1136unsigned char sha1[20];1137const char*refname;1138const char*traits;11391140if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1141if(strstr(traits," fully-peeled "))1142 peeled = PEELED_FULLY;1143else if(strstr(traits," peeled "))1144 peeled = PEELED_TAGS;1145/* perhaps other traits later as well */1146continue;1147}11481149 refname =parse_ref_line(&line, sha1);1150if(refname) {1151int flag = REF_ISPACKED;11521153if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1154hashclr(sha1);1155 flag |= REF_BAD_NAME | REF_ISBROKEN;1156}1157 last =create_ref_entry(refname, sha1, flag,0);1158if(peeled == PEELED_FULLY ||1159(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1160 last->flag |= REF_KNOWS_PEELED;1161add_ref(dir, last);1162continue;1163}1164if(last &&1165 line.buf[0] =='^'&&1166 line.len == PEELED_LINE_LENGTH &&1167 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1168!get_sha1_hex(line.buf +1, sha1)) {1169hashcpy(last->u.value.peeled, sha1);1170/*1171 * Regardless of what the file header said,1172 * we definitely know the value of *this*1173 * reference:1174 */1175 last->flag |= REF_KNOWS_PEELED;1176}1177}11781179strbuf_release(&line);1180}11811182/*1183 * Get the packed_ref_cache for the specified ref_cache, creating it1184 * if necessary.1185 */1186static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1187{1188const char*packed_refs_file;11891190if(*refs->name)1191 packed_refs_file =git_path_submodule(refs->name,"packed-refs");1192else1193 packed_refs_file =git_path("packed-refs");11941195if(refs->packed &&1196!stat_validity_check(&refs->packed->validity, packed_refs_file))1197clear_packed_ref_cache(refs);11981199if(!refs->packed) {1200FILE*f;12011202 refs->packed =xcalloc(1,sizeof(*refs->packed));1203acquire_packed_ref_cache(refs->packed);1204 refs->packed->root =create_dir_entry(refs,"",0,0);1205 f =fopen(packed_refs_file,"r");1206if(f) {1207stat_validity_update(&refs->packed->validity,fileno(f));1208read_packed_refs(f,get_ref_dir(refs->packed->root));1209fclose(f);1210}1211}1212return refs->packed;1213}12141215static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1216{1217returnget_ref_dir(packed_ref_cache->root);1218}12191220static struct ref_dir *get_packed_refs(struct ref_cache *refs)1221{1222returnget_packed_ref_dir(get_packed_ref_cache(refs));1223}12241225voidadd_packed_ref(const char*refname,const unsigned char*sha1)1226{1227struct packed_ref_cache *packed_ref_cache =1228get_packed_ref_cache(&ref_cache);12291230if(!packed_ref_cache->lock)1231die("internal error: packed refs not locked");1232add_ref(get_packed_ref_dir(packed_ref_cache),1233create_ref_entry(refname, sha1, REF_ISPACKED,1));1234}12351236/*1237 * Read the loose references from the namespace dirname into dir1238 * (without recursing). dirname must end with '/'. dir must be the1239 * directory entry corresponding to dirname.1240 */1241static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1242{1243struct ref_cache *refs = dir->ref_cache;1244DIR*d;1245const char*path;1246struct dirent *de;1247int dirnamelen =strlen(dirname);1248struct strbuf refname;12491250if(*refs->name)1251 path =git_path_submodule(refs->name,"%s", dirname);1252else1253 path =git_path("%s", dirname);12541255 d =opendir(path);1256if(!d)1257return;12581259strbuf_init(&refname, dirnamelen +257);1260strbuf_add(&refname, dirname, dirnamelen);12611262while((de =readdir(d)) != NULL) {1263unsigned char sha1[20];1264struct stat st;1265int flag;1266const char*refdir;12671268if(de->d_name[0] =='.')1269continue;1270if(ends_with(de->d_name,".lock"))1271continue;1272strbuf_addstr(&refname, de->d_name);1273 refdir = *refs->name1274?git_path_submodule(refs->name,"%s", refname.buf)1275:git_path("%s", refname.buf);1276if(stat(refdir, &st) <0) {1277;/* silently ignore */1278}else if(S_ISDIR(st.st_mode)) {1279strbuf_addch(&refname,'/');1280add_entry_to_dir(dir,1281create_dir_entry(refs, refname.buf,1282 refname.len,1));1283}else{1284if(*refs->name) {1285hashclr(sha1);1286 flag =0;1287if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1288hashclr(sha1);1289 flag |= REF_ISBROKEN;1290}1291}else if(read_ref_full(refname.buf,1292 RESOLVE_REF_READING,1293 sha1, &flag)) {1294hashclr(sha1);1295 flag |= REF_ISBROKEN;1296}1297if(check_refname_format(refname.buf,1298 REFNAME_ALLOW_ONELEVEL)) {1299hashclr(sha1);1300 flag |= REF_BAD_NAME | REF_ISBROKEN;1301}1302add_entry_to_dir(dir,1303create_ref_entry(refname.buf, sha1, flag,0));1304}1305strbuf_setlen(&refname, dirnamelen);1306}1307strbuf_release(&refname);1308closedir(d);1309}13101311static struct ref_dir *get_loose_refs(struct ref_cache *refs)1312{1313if(!refs->loose) {1314/*1315 * Mark the top-level directory complete because we1316 * are about to read the only subdirectory that can1317 * hold references:1318 */1319 refs->loose =create_dir_entry(refs,"",0,0);1320/*1321 * Create an incomplete entry for "refs/":1322 */1323add_entry_to_dir(get_ref_dir(refs->loose),1324create_dir_entry(refs,"refs/",5,1));1325}1326returnget_ref_dir(refs->loose);1327}13281329/* We allow "recursive" symbolic refs. Only within reason, though */1330#define MAXDEPTH 51331#define MAXREFLEN (1024)13321333/*1334 * Called by resolve_gitlink_ref_recursive() after it failed to read1335 * from the loose refs in ref_cache refs. Find <refname> in the1336 * packed-refs file for the submodule.1337 */1338static intresolve_gitlink_packed_ref(struct ref_cache *refs,1339const char*refname,unsigned char*sha1)1340{1341struct ref_entry *ref;1342struct ref_dir *dir =get_packed_refs(refs);13431344 ref =find_ref(dir, refname);1345if(ref == NULL)1346return-1;13471348hashcpy(sha1, ref->u.value.sha1);1349return0;1350}13511352static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1353const char*refname,unsigned char*sha1,1354int recursion)1355{1356int fd, len;1357char buffer[128], *p;1358char*path;13591360if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1361return-1;1362 path = *refs->name1363?git_path_submodule(refs->name,"%s", refname)1364:git_path("%s", refname);1365 fd =open(path, O_RDONLY);1366if(fd <0)1367returnresolve_gitlink_packed_ref(refs, refname, sha1);13681369 len =read(fd, buffer,sizeof(buffer)-1);1370close(fd);1371if(len <0)1372return-1;1373while(len &&isspace(buffer[len-1]))1374 len--;1375 buffer[len] =0;13761377/* Was it a detached head or an old-fashioned symlink? */1378if(!get_sha1_hex(buffer, sha1))1379return0;13801381/* Symref? */1382if(strncmp(buffer,"ref:",4))1383return-1;1384 p = buffer +4;1385while(isspace(*p))1386 p++;13871388returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1389}13901391intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1392{1393int len =strlen(path), retval;1394char*submodule;1395struct ref_cache *refs;13961397while(len && path[len-1] =='/')1398 len--;1399if(!len)1400return-1;1401 submodule =xstrndup(path, len);1402 refs =get_ref_cache(submodule);1403free(submodule);14041405 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1406return retval;1407}14081409/*1410 * Return the ref_entry for the given refname from the packed1411 * references. If it does not exist, return NULL.1412 */1413static struct ref_entry *get_packed_ref(const char*refname)1414{1415returnfind_ref(get_packed_refs(&ref_cache), refname);1416}14171418/*1419 * A loose ref file doesn't exist; check for a packed ref. The1420 * options are forwarded from resolve_safe_unsafe().1421 */1422static intresolve_missing_loose_ref(const char*refname,1423int resolve_flags,1424unsigned char*sha1,1425int*flags)1426{1427struct ref_entry *entry;14281429/*1430 * The loose reference file does not exist; check for a packed1431 * reference.1432 */1433 entry =get_packed_ref(refname);1434if(entry) {1435hashcpy(sha1, entry->u.value.sha1);1436if(flags)1437*flags |= REF_ISPACKED;1438return0;1439}1440/* The reference is not a packed reference, either. */1441if(resolve_flags & RESOLVE_REF_READING) {1442 errno = ENOENT;1443return-1;1444}else{1445hashclr(sha1);1446return0;1447}1448}14491450/* This function needs to return a meaningful errno on failure */1451const char*resolve_ref_unsafe(const char*refname,int resolve_flags,unsigned char*sha1,int*flags)1452{1453int depth = MAXDEPTH;1454 ssize_t len;1455char buffer[256];1456static char refname_buffer[256];1457int bad_name =0;14581459if(flags)1460*flags =0;14611462if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1463if(flags)1464*flags |= REF_BAD_NAME;14651466if(!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1467!refname_is_safe(refname)) {1468 errno = EINVAL;1469return NULL;1470}1471/*1472 * dwim_ref() uses REF_ISBROKEN to distinguish between1473 * missing refs and refs that were present but invalid,1474 * to complain about the latter to stderr.1475 *1476 * We don't know whether the ref exists, so don't set1477 * REF_ISBROKEN yet.1478 */1479 bad_name =1;1480}1481for(;;) {1482char path[PATH_MAX];1483struct stat st;1484char*buf;1485int fd;14861487if(--depth <0) {1488 errno = ELOOP;1489return NULL;1490}14911492git_snpath(path,sizeof(path),"%s", refname);14931494/*1495 * We might have to loop back here to avoid a race1496 * condition: first we lstat() the file, then we try1497 * to read it as a link or as a file. But if somebody1498 * changes the type of the file (file <-> directory1499 * <-> symlink) between the lstat() and reading, then1500 * we don't want to report that as an error but rather1501 * try again starting with the lstat().1502 */1503 stat_ref:1504if(lstat(path, &st) <0) {1505if(errno != ENOENT)1506return NULL;1507if(resolve_missing_loose_ref(refname, resolve_flags,1508 sha1, flags))1509return NULL;1510if(bad_name) {1511hashclr(sha1);1512if(flags)1513*flags |= REF_ISBROKEN;1514}1515return refname;1516}15171518/* Follow "normalized" - ie "refs/.." symlinks by hand */1519if(S_ISLNK(st.st_mode)) {1520 len =readlink(path, buffer,sizeof(buffer)-1);1521if(len <0) {1522if(errno == ENOENT || errno == EINVAL)1523/* inconsistent with lstat; retry */1524goto stat_ref;1525else1526return NULL;1527}1528 buffer[len] =0;1529if(starts_with(buffer,"refs/") &&1530!check_refname_format(buffer,0)) {1531strcpy(refname_buffer, buffer);1532 refname = refname_buffer;1533if(flags)1534*flags |= REF_ISSYMREF;1535if(resolve_flags & RESOLVE_REF_NO_RECURSE) {1536hashclr(sha1);1537return refname;1538}1539continue;1540}1541}15421543/* Is it a directory? */1544if(S_ISDIR(st.st_mode)) {1545 errno = EISDIR;1546return NULL;1547}15481549/*1550 * Anything else, just open it and try to use it as1551 * a ref1552 */1553 fd =open(path, O_RDONLY);1554if(fd <0) {1555if(errno == ENOENT)1556/* inconsistent with lstat; retry */1557goto stat_ref;1558else1559return NULL;1560}1561 len =read_in_full(fd, buffer,sizeof(buffer)-1);1562if(len <0) {1563int save_errno = errno;1564close(fd);1565 errno = save_errno;1566return NULL;1567}1568close(fd);1569while(len &&isspace(buffer[len-1]))1570 len--;1571 buffer[len] ='\0';15721573/*1574 * Is it a symbolic ref?1575 */1576if(!starts_with(buffer,"ref:")) {1577/*1578 * Please note that FETCH_HEAD has a second1579 * line containing other data.1580 */1581if(get_sha1_hex(buffer, sha1) ||1582(buffer[40] !='\0'&& !isspace(buffer[40]))) {1583if(flags)1584*flags |= REF_ISBROKEN;1585 errno = EINVAL;1586return NULL;1587}1588if(bad_name) {1589hashclr(sha1);1590if(flags)1591*flags |= REF_ISBROKEN;1592}1593return refname;1594}1595if(flags)1596*flags |= REF_ISSYMREF;1597 buf = buffer +4;1598while(isspace(*buf))1599 buf++;1600 refname =strcpy(refname_buffer, buf);1601if(resolve_flags & RESOLVE_REF_NO_RECURSE) {1602hashclr(sha1);1603return refname;1604}1605if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1606if(flags)1607*flags |= REF_ISBROKEN;16081609if(!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1610!refname_is_safe(buf)) {1611 errno = EINVAL;1612return NULL;1613}1614 bad_name =1;1615}1616}1617}16181619char*resolve_refdup(const char*ref,int resolve_flags,unsigned char*sha1,int*flags)1620{1621const char*ret =resolve_ref_unsafe(ref, resolve_flags, sha1, flags);1622return ret ?xstrdup(ret) : NULL;1623}16241625/* The argument to filter_refs */1626struct ref_filter {1627const char*pattern;1628 each_ref_fn *fn;1629void*cb_data;1630};16311632intread_ref_full(const char*refname,int resolve_flags,unsigned char*sha1,int*flags)1633{1634if(resolve_ref_unsafe(refname, resolve_flags, sha1, flags))1635return0;1636return-1;1637}16381639intread_ref(const char*refname,unsigned char*sha1)1640{1641returnread_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);1642}16431644intref_exists(const char*refname)1645{1646unsigned char sha1[20];1647return!!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);1648}16491650static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1651void*data)1652{1653struct ref_filter *filter = (struct ref_filter *)data;1654if(wildmatch(filter->pattern, refname,0, NULL))1655return0;1656return filter->fn(refname, sha1, flags, filter->cb_data);1657}16581659enum peel_status {1660/* object was peeled successfully: */1661 PEEL_PEELED =0,16621663/*1664 * object cannot be peeled because the named object (or an1665 * object referred to by a tag in the peel chain), does not1666 * exist.1667 */1668 PEEL_INVALID = -1,16691670/* object cannot be peeled because it is not a tag: */1671 PEEL_NON_TAG = -2,16721673/* ref_entry contains no peeled value because it is a symref: */1674 PEEL_IS_SYMREF = -3,16751676/*1677 * ref_entry cannot be peeled because it is broken (i.e., the1678 * symbolic reference cannot even be resolved to an object1679 * name):1680 */1681 PEEL_BROKEN = -41682};16831684/*1685 * Peel the named object; i.e., if the object is a tag, resolve the1686 * tag recursively until a non-tag is found. If successful, store the1687 * result to sha1 and return PEEL_PEELED. If the object is not a tag1688 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1689 * and leave sha1 unchanged.1690 */1691static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1692{1693struct object *o =lookup_unknown_object(name);16941695if(o->type == OBJ_NONE) {1696int type =sha1_object_info(name, NULL);1697if(type <0|| !object_as_type(o, type,0))1698return PEEL_INVALID;1699}17001701if(o->type != OBJ_TAG)1702return PEEL_NON_TAG;17031704 o =deref_tag_noverify(o);1705if(!o)1706return PEEL_INVALID;17071708hashcpy(sha1, o->sha1);1709return PEEL_PEELED;1710}17111712/*1713 * Peel the entry (if possible) and return its new peel_status. If1714 * repeel is true, re-peel the entry even if there is an old peeled1715 * value that is already stored in it.1716 *1717 * It is OK to call this function with a packed reference entry that1718 * might be stale and might even refer to an object that has since1719 * been garbage-collected. In such a case, if the entry has1720 * REF_KNOWS_PEELED then leave the status unchanged and return1721 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1722 */1723static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1724{1725enum peel_status status;17261727if(entry->flag & REF_KNOWS_PEELED) {1728if(repeel) {1729 entry->flag &= ~REF_KNOWS_PEELED;1730hashclr(entry->u.value.peeled);1731}else{1732returnis_null_sha1(entry->u.value.peeled) ?1733 PEEL_NON_TAG : PEEL_PEELED;1734}1735}1736if(entry->flag & REF_ISBROKEN)1737return PEEL_BROKEN;1738if(entry->flag & REF_ISSYMREF)1739return PEEL_IS_SYMREF;17401741 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1742if(status == PEEL_PEELED || status == PEEL_NON_TAG)1743 entry->flag |= REF_KNOWS_PEELED;1744return status;1745}17461747intpeel_ref(const char*refname,unsigned char*sha1)1748{1749int flag;1750unsigned char base[20];17511752if(current_ref && (current_ref->name == refname1753|| !strcmp(current_ref->name, refname))) {1754if(peel_entry(current_ref,0))1755return-1;1756hashcpy(sha1, current_ref->u.value.peeled);1757return0;1758}17591760if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1761return-1;17621763/*1764 * If the reference is packed, read its ref_entry from the1765 * cache in the hope that we already know its peeled value.1766 * We only try this optimization on packed references because1767 * (a) forcing the filling of the loose reference cache could1768 * be expensive and (b) loose references anyway usually do not1769 * have REF_KNOWS_PEELED.1770 */1771if(flag & REF_ISPACKED) {1772struct ref_entry *r =get_packed_ref(refname);1773if(r) {1774if(peel_entry(r,0))1775return-1;1776hashcpy(sha1, r->u.value.peeled);1777return0;1778}1779}17801781returnpeel_object(base, sha1);1782}17831784struct warn_if_dangling_data {1785FILE*fp;1786const char*refname;1787const struct string_list *refnames;1788const char*msg_fmt;1789};17901791static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1792int flags,void*cb_data)1793{1794struct warn_if_dangling_data *d = cb_data;1795const char*resolves_to;1796unsigned char junk[20];17971798if(!(flags & REF_ISSYMREF))1799return0;18001801 resolves_to =resolve_ref_unsafe(refname,0, junk, NULL);1802if(!resolves_to1803|| (d->refname1804?strcmp(resolves_to, d->refname)1805: !string_list_has_string(d->refnames, resolves_to))) {1806return0;1807}18081809fprintf(d->fp, d->msg_fmt, refname);1810fputc('\n', d->fp);1811return0;1812}18131814voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1815{1816struct warn_if_dangling_data data;18171818 data.fp = fp;1819 data.refname = refname;1820 data.refnames = NULL;1821 data.msg_fmt = msg_fmt;1822for_each_rawref(warn_if_dangling_symref, &data);1823}18241825voidwarn_dangling_symrefs(FILE*fp,const char*msg_fmt,const struct string_list *refnames)1826{1827struct warn_if_dangling_data data;18281829 data.fp = fp;1830 data.refname = NULL;1831 data.refnames = refnames;1832 data.msg_fmt = msg_fmt;1833for_each_rawref(warn_if_dangling_symref, &data);1834}18351836/*1837 * Call fn for each reference in the specified ref_cache, omitting1838 * references not in the containing_dir of base. fn is called for all1839 * references, including broken ones. If fn ever returns a non-zero1840 * value, stop the iteration and return that value; otherwise, return1841 * 0.1842 */1843static intdo_for_each_entry(struct ref_cache *refs,const char*base,1844 each_ref_entry_fn fn,void*cb_data)1845{1846struct packed_ref_cache *packed_ref_cache;1847struct ref_dir *loose_dir;1848struct ref_dir *packed_dir;1849int retval =0;18501851/*1852 * We must make sure that all loose refs are read before accessing the1853 * packed-refs file; this avoids a race condition in which loose refs1854 * are migrated to the packed-refs file by a simultaneous process, but1855 * our in-memory view is from before the migration. get_packed_ref_cache()1856 * takes care of making sure our view is up to date with what is on1857 * disk.1858 */1859 loose_dir =get_loose_refs(refs);1860if(base && *base) {1861 loose_dir =find_containing_dir(loose_dir, base,0);1862}1863if(loose_dir)1864prime_ref_dir(loose_dir);18651866 packed_ref_cache =get_packed_ref_cache(refs);1867acquire_packed_ref_cache(packed_ref_cache);1868 packed_dir =get_packed_ref_dir(packed_ref_cache);1869if(base && *base) {1870 packed_dir =find_containing_dir(packed_dir, base,0);1871}18721873if(packed_dir && loose_dir) {1874sort_ref_dir(packed_dir);1875sort_ref_dir(loose_dir);1876 retval =do_for_each_entry_in_dirs(1877 packed_dir, loose_dir, fn, cb_data);1878}else if(packed_dir) {1879sort_ref_dir(packed_dir);1880 retval =do_for_each_entry_in_dir(1881 packed_dir,0, fn, cb_data);1882}else if(loose_dir) {1883sort_ref_dir(loose_dir);1884 retval =do_for_each_entry_in_dir(1885 loose_dir,0, fn, cb_data);1886}18871888release_packed_ref_cache(packed_ref_cache);1889return retval;1890}18911892/*1893 * Call fn for each reference in the specified ref_cache for which the1894 * refname begins with base. If trim is non-zero, then trim that many1895 * characters off the beginning of each refname before passing the1896 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1897 * broken references in the iteration. If fn ever returns a non-zero1898 * value, stop the iteration and return that value; otherwise, return1899 * 0.1900 */1901static intdo_for_each_ref(struct ref_cache *refs,const char*base,1902 each_ref_fn fn,int trim,int flags,void*cb_data)1903{1904struct ref_entry_cb data;1905 data.base = base;1906 data.trim = trim;1907 data.flags = flags;1908 data.fn = fn;1909 data.cb_data = cb_data;19101911returndo_for_each_entry(refs, base, do_one_ref, &data);1912}19131914static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1915{1916unsigned char sha1[20];1917int flag;19181919if(submodule) {1920if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1921returnfn("HEAD", sha1,0, cb_data);19221923return0;1924}19251926if(!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))1927returnfn("HEAD", sha1, flag, cb_data);19281929return0;1930}19311932inthead_ref(each_ref_fn fn,void*cb_data)1933{1934returndo_head_ref(NULL, fn, cb_data);1935}19361937inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1938{1939returndo_head_ref(submodule, fn, cb_data);1940}19411942intfor_each_ref(each_ref_fn fn,void*cb_data)1943{1944returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1945}19461947intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1948{1949returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1950}19511952intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)1953{1954returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);1955}19561957intfor_each_ref_in_submodule(const char*submodule,const char*prefix,1958 each_ref_fn fn,void*cb_data)1959{1960returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);1961}19621963intfor_each_tag_ref(each_ref_fn fn,void*cb_data)1964{1965returnfor_each_ref_in("refs/tags/", fn, cb_data);1966}19671968intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1969{1970returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);1971}19721973intfor_each_branch_ref(each_ref_fn fn,void*cb_data)1974{1975returnfor_each_ref_in("refs/heads/", fn, cb_data);1976}19771978intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1979{1980returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);1981}19821983intfor_each_remote_ref(each_ref_fn fn,void*cb_data)1984{1985returnfor_each_ref_in("refs/remotes/", fn, cb_data);1986}19871988intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1989{1990returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);1991}19921993intfor_each_replace_ref(each_ref_fn fn,void*cb_data)1994{1995returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);1996}19971998inthead_ref_namespaced(each_ref_fn fn,void*cb_data)1999{2000struct strbuf buf = STRBUF_INIT;2001int ret =0;2002unsigned char sha1[20];2003int flag;20042005strbuf_addf(&buf,"%sHEAD",get_git_namespace());2006if(!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))2007 ret =fn(buf.buf, sha1, flag, cb_data);2008strbuf_release(&buf);20092010return ret;2011}20122013intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)2014{2015struct strbuf buf = STRBUF_INIT;2016int ret;2017strbuf_addf(&buf,"%srefs/",get_git_namespace());2018 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);2019strbuf_release(&buf);2020return ret;2021}20222023intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,2024const char*prefix,void*cb_data)2025{2026struct strbuf real_pattern = STRBUF_INIT;2027struct ref_filter filter;2028int ret;20292030if(!prefix && !starts_with(pattern,"refs/"))2031strbuf_addstr(&real_pattern,"refs/");2032else if(prefix)2033strbuf_addstr(&real_pattern, prefix);2034strbuf_addstr(&real_pattern, pattern);20352036if(!has_glob_specials(pattern)) {2037/* Append implied '/' '*' if not present. */2038if(real_pattern.buf[real_pattern.len -1] !='/')2039strbuf_addch(&real_pattern,'/');2040/* No need to check for '*', there is none. */2041strbuf_addch(&real_pattern,'*');2042}20432044 filter.pattern = real_pattern.buf;2045 filter.fn = fn;2046 filter.cb_data = cb_data;2047 ret =for_each_ref(filter_refs, &filter);20482049strbuf_release(&real_pattern);2050return ret;2051}20522053intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)2054{2055returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);2056}20572058intfor_each_rawref(each_ref_fn fn,void*cb_data)2059{2060returndo_for_each_ref(&ref_cache,"", fn,0,2061 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2062}20632064const char*prettify_refname(const char*name)2065{2066return name + (2067starts_with(name,"refs/heads/") ?11:2068starts_with(name,"refs/tags/") ?10:2069starts_with(name,"refs/remotes/") ?13:20700);2071}20722073static const char*ref_rev_parse_rules[] = {2074"%.*s",2075"refs/%.*s",2076"refs/tags/%.*s",2077"refs/heads/%.*s",2078"refs/remotes/%.*s",2079"refs/remotes/%.*s/HEAD",2080 NULL2081};20822083intrefname_match(const char*abbrev_name,const char*full_name)2084{2085const char**p;2086const int abbrev_name_len =strlen(abbrev_name);20872088for(p = ref_rev_parse_rules; *p; p++) {2089if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {2090return1;2091}2092}20932094return0;2095}20962097/* This function should make sure errno is meaningful on error */2098static struct ref_lock *verify_lock(struct ref_lock *lock,2099const unsigned char*old_sha1,int mustexist)2100{2101if(read_ref_full(lock->ref_name,2102 mustexist ? RESOLVE_REF_READING :0,2103 lock->old_sha1, NULL)) {2104int save_errno = errno;2105error("Can't verify ref%s", lock->ref_name);2106unlock_ref(lock);2107 errno = save_errno;2108return NULL;2109}2110if(hashcmp(lock->old_sha1, old_sha1)) {2111error("Ref%sis at%sbut expected%s", lock->ref_name,2112sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));2113unlock_ref(lock);2114 errno = EBUSY;2115return NULL;2116}2117return lock;2118}21192120static intremove_empty_directories(const char*file)2121{2122/* we want to create a file but there is a directory there;2123 * if that is an empty directory (or a directory that contains2124 * only empty directories), remove them.2125 */2126struct strbuf path;2127int result, save_errno;21282129strbuf_init(&path,20);2130strbuf_addstr(&path, file);21312132 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);2133 save_errno = errno;21342135strbuf_release(&path);2136 errno = save_errno;21372138return result;2139}21402141/*2142 * *string and *len will only be substituted, and *string returned (for2143 * later free()ing) if the string passed in is a magic short-hand form2144 * to name a branch.2145 */2146static char*substitute_branch_name(const char**string,int*len)2147{2148struct strbuf buf = STRBUF_INIT;2149int ret =interpret_branch_name(*string, *len, &buf);21502151if(ret == *len) {2152size_t size;2153*string =strbuf_detach(&buf, &size);2154*len = size;2155return(char*)*string;2156}21572158return NULL;2159}21602161intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)2162{2163char*last_branch =substitute_branch_name(&str, &len);2164const char**p, *r;2165int refs_found =0;21662167*ref = NULL;2168for(p = ref_rev_parse_rules; *p; p++) {2169char fullref[PATH_MAX];2170unsigned char sha1_from_ref[20];2171unsigned char*this_result;2172int flag;21732174 this_result = refs_found ? sha1_from_ref : sha1;2175mksnpath(fullref,sizeof(fullref), *p, len, str);2176 r =resolve_ref_unsafe(fullref, RESOLVE_REF_READING,2177 this_result, &flag);2178if(r) {2179if(!refs_found++)2180*ref =xstrdup(r);2181if(!warn_ambiguous_refs)2182break;2183}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {2184warning("ignoring dangling symref%s.", fullref);2185}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {2186warning("ignoring broken ref%s.", fullref);2187}2188}2189free(last_branch);2190return refs_found;2191}21922193intdwim_log(const char*str,int len,unsigned char*sha1,char**log)2194{2195char*last_branch =substitute_branch_name(&str, &len);2196const char**p;2197int logs_found =0;21982199*log = NULL;2200for(p = ref_rev_parse_rules; *p; p++) {2201unsigned char hash[20];2202char path[PATH_MAX];2203const char*ref, *it;22042205mksnpath(path,sizeof(path), *p, len, str);2206 ref =resolve_ref_unsafe(path, RESOLVE_REF_READING,2207 hash, NULL);2208if(!ref)2209continue;2210if(reflog_exists(path))2211 it = path;2212else if(strcmp(ref, path) &&reflog_exists(ref))2213 it = ref;2214else2215continue;2216if(!logs_found++) {2217*log =xstrdup(it);2218hashcpy(sha1, hash);2219}2220if(!warn_ambiguous_refs)2221break;2222}2223free(last_branch);2224return logs_found;2225}22262227/*2228 * Locks a ref returning the lock on success and NULL on failure.2229 * On failure errno is set to something meaningful.2230 */2231static struct ref_lock *lock_ref_sha1_basic(const char*refname,2232const unsigned char*old_sha1,2233const struct string_list *skip,2234int flags,int*type_p)2235{2236char*ref_file;2237const char*orig_refname = refname;2238struct ref_lock *lock;2239int last_errno =0;2240int type, lflags;2241int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2242int resolve_flags =0;2243int missing =0;2244int attempts_remaining =3;22452246 lock =xcalloc(1,sizeof(struct ref_lock));2247 lock->lock_fd = -1;22482249if(mustexist)2250 resolve_flags |= RESOLVE_REF_READING;2251if(flags & REF_DELETING) {2252 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;2253if(flags & REF_NODEREF)2254 resolve_flags |= RESOLVE_REF_NO_RECURSE;2255}22562257 refname =resolve_ref_unsafe(refname, resolve_flags,2258 lock->old_sha1, &type);2259if(!refname && errno == EISDIR) {2260/* we are trying to lock foo but we used to2261 * have foo/bar which now does not exist;2262 * it is normal for the empty directory 'foo'2263 * to remain.2264 */2265 ref_file =git_path("%s", orig_refname);2266if(remove_empty_directories(ref_file)) {2267 last_errno = errno;2268error("there are still refs under '%s'", orig_refname);2269goto error_return;2270}2271 refname =resolve_ref_unsafe(orig_refname, resolve_flags,2272 lock->old_sha1, &type);2273}2274if(type_p)2275*type_p = type;2276if(!refname) {2277 last_errno = errno;2278error("unable to resolve reference%s:%s",2279 orig_refname,strerror(errno));2280goto error_return;2281}2282 missing =is_null_sha1(lock->old_sha1);2283/* When the ref did not exist and we are creating it,2284 * make sure there is no existing ref that is packed2285 * whose name begins with our refname, nor a ref whose2286 * name is a proper prefix of our refname.2287 */2288if(missing &&2289!is_refname_available(refname, skip,get_packed_refs(&ref_cache))) {2290 last_errno = ENOTDIR;2291goto error_return;2292}22932294 lock->lk =xcalloc(1,sizeof(struct lock_file));22952296 lflags =0;2297if(flags & REF_NODEREF) {2298 refname = orig_refname;2299 lflags |= LOCK_NO_DEREF;2300}2301 lock->ref_name =xstrdup(refname);2302 lock->orig_ref_name =xstrdup(orig_refname);2303 ref_file =git_path("%s", refname);2304if(missing)2305 lock->force_write =1;2306if((flags & REF_NODEREF) && (type & REF_ISSYMREF))2307 lock->force_write =1;23082309 retry:2310switch(safe_create_leading_directories(ref_file)) {2311case SCLD_OK:2312break;/* success */2313case SCLD_VANISHED:2314if(--attempts_remaining >0)2315goto retry;2316/* fall through */2317default:2318 last_errno = errno;2319error("unable to create directory for%s", ref_file);2320goto error_return;2321}23222323 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);2324if(lock->lock_fd <0) {2325if(errno == ENOENT && --attempts_remaining >0)2326/*2327 * Maybe somebody just deleted one of the2328 * directories leading to ref_file. Try2329 * again:2330 */2331goto retry;2332else2333unable_to_lock_die(ref_file, errno);2334}2335return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;23362337 error_return:2338unlock_ref(lock);2339 errno = last_errno;2340return NULL;2341}23422343struct ref_lock *lock_any_ref_for_update(const char*refname,2344const unsigned char*old_sha1,2345int flags,int*type_p)2346{2347returnlock_ref_sha1_basic(refname, old_sha1, NULL, flags, type_p);2348}23492350/*2351 * Write an entry to the packed-refs file for the specified refname.2352 * If peeled is non-NULL, write it as the entry's peeled value.2353 */2354static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2355unsigned char*peeled)2356{2357fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2358if(peeled)2359fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2360}23612362/*2363 * An each_ref_entry_fn that writes the entry to a packed-refs file.2364 */2365static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2366{2367enum peel_status peel_status =peel_entry(entry,0);23682369if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2370error("internal error:%sis not a valid packed reference!",2371 entry->name);2372write_packed_entry(cb_data, entry->name, entry->u.value.sha1,2373 peel_status == PEEL_PEELED ?2374 entry->u.value.peeled : NULL);2375return0;2376}23772378/* This should return a meaningful errno on failure */2379intlock_packed_refs(int flags)2380{2381struct packed_ref_cache *packed_ref_cache;23822383if(hold_lock_file_for_update(&packlock,git_path("packed-refs"), flags) <0)2384return-1;2385/*2386 * Get the current packed-refs while holding the lock. If the2387 * packed-refs file has been modified since we last read it,2388 * this will automatically invalidate the cache and re-read2389 * the packed-refs file.2390 */2391 packed_ref_cache =get_packed_ref_cache(&ref_cache);2392 packed_ref_cache->lock = &packlock;2393/* Increment the reference count to prevent it from being freed: */2394acquire_packed_ref_cache(packed_ref_cache);2395return0;2396}23972398/*2399 * Commit the packed refs changes.2400 * On error we must make sure that errno contains a meaningful value.2401 */2402intcommit_packed_refs(void)2403{2404struct packed_ref_cache *packed_ref_cache =2405get_packed_ref_cache(&ref_cache);2406int error =0;2407int save_errno =0;2408FILE*out;24092410if(!packed_ref_cache->lock)2411die("internal error: packed-refs not locked");24122413 out =fdopen_lock_file(packed_ref_cache->lock,"w");2414if(!out)2415die_errno("unable to fdopen packed-refs descriptor");24162417fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2418do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),24190, write_packed_entry_fn, out);24202421if(commit_lock_file(packed_ref_cache->lock)) {2422 save_errno = errno;2423 error = -1;2424}2425 packed_ref_cache->lock = NULL;2426release_packed_ref_cache(packed_ref_cache);2427 errno = save_errno;2428return error;2429}24302431voidrollback_packed_refs(void)2432{2433struct packed_ref_cache *packed_ref_cache =2434get_packed_ref_cache(&ref_cache);24352436if(!packed_ref_cache->lock)2437die("internal error: packed-refs not locked");2438rollback_lock_file(packed_ref_cache->lock);2439 packed_ref_cache->lock = NULL;2440release_packed_ref_cache(packed_ref_cache);2441clear_packed_ref_cache(&ref_cache);2442}24432444struct ref_to_prune {2445struct ref_to_prune *next;2446unsigned char sha1[20];2447char name[FLEX_ARRAY];2448};24492450struct pack_refs_cb_data {2451unsigned int flags;2452struct ref_dir *packed_refs;2453struct ref_to_prune *ref_to_prune;2454};24552456/*2457 * An each_ref_entry_fn that is run over loose references only. If2458 * the loose reference can be packed, add an entry in the packed ref2459 * cache. If the reference should be pruned, also add it to2460 * ref_to_prune in the pack_refs_cb_data.2461 */2462static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2463{2464struct pack_refs_cb_data *cb = cb_data;2465enum peel_status peel_status;2466struct ref_entry *packed_entry;2467int is_tag_ref =starts_with(entry->name,"refs/tags/");24682469/* ALWAYS pack tags */2470if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2471return0;24722473/* Do not pack symbolic or broken refs: */2474if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2475return0;24762477/* Add a packed ref cache entry equivalent to the loose entry. */2478 peel_status =peel_entry(entry,1);2479if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2480die("internal error peeling reference%s(%s)",2481 entry->name,sha1_to_hex(entry->u.value.sha1));2482 packed_entry =find_ref(cb->packed_refs, entry->name);2483if(packed_entry) {2484/* Overwrite existing packed entry with info from loose entry */2485 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2486hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2487}else{2488 packed_entry =create_ref_entry(entry->name, entry->u.value.sha1,2489 REF_ISPACKED | REF_KNOWS_PEELED,0);2490add_ref(cb->packed_refs, packed_entry);2491}2492hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);24932494/* Schedule the loose reference for pruning if requested. */2495if((cb->flags & PACK_REFS_PRUNE)) {2496int namelen =strlen(entry->name) +1;2497struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2498hashcpy(n->sha1, entry->u.value.sha1);2499strcpy(n->name, entry->name);2500 n->next = cb->ref_to_prune;2501 cb->ref_to_prune = n;2502}2503return0;2504}25052506/*2507 * Remove empty parents, but spare refs/ and immediate subdirs.2508 * Note: munges *name.2509 */2510static voidtry_remove_empty_parents(char*name)2511{2512char*p, *q;2513int i;2514 p = name;2515for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2516while(*p && *p !='/')2517 p++;2518/* tolerate duplicate slashes; see check_refname_format() */2519while(*p =='/')2520 p++;2521}2522for(q = p; *q; q++)2523;2524while(1) {2525while(q > p && *q !='/')2526 q--;2527while(q > p && *(q-1) =='/')2528 q--;2529if(q == p)2530break;2531*q ='\0';2532if(rmdir(git_path("%s", name)))2533break;2534}2535}25362537/* make sure nobody touched the ref, and unlink */2538static voidprune_ref(struct ref_to_prune *r)2539{2540struct ref_transaction *transaction;2541struct strbuf err = STRBUF_INIT;25422543if(check_refname_format(r->name,0))2544return;25452546 transaction =ref_transaction_begin(&err);2547if(!transaction ||2548ref_transaction_delete(transaction, r->name, r->sha1,2549 REF_ISPRUNING,1, NULL, &err) ||2550ref_transaction_commit(transaction, &err)) {2551ref_transaction_free(transaction);2552error("%s", err.buf);2553strbuf_release(&err);2554return;2555}2556ref_transaction_free(transaction);2557strbuf_release(&err);2558try_remove_empty_parents(r->name);2559}25602561static voidprune_refs(struct ref_to_prune *r)2562{2563while(r) {2564prune_ref(r);2565 r = r->next;2566}2567}25682569intpack_refs(unsigned int flags)2570{2571struct pack_refs_cb_data cbdata;25722573memset(&cbdata,0,sizeof(cbdata));2574 cbdata.flags = flags;25752576lock_packed_refs(LOCK_DIE_ON_ERROR);2577 cbdata.packed_refs =get_packed_refs(&ref_cache);25782579do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2580 pack_if_possible_fn, &cbdata);25812582if(commit_packed_refs())2583die_errno("unable to overwrite old ref-pack file");25842585prune_refs(cbdata.ref_to_prune);2586return0;2587}25882589/*2590 * If entry is no longer needed in packed-refs, add it to the string2591 * list pointed to by cb_data. Reasons for deleting entries:2592 *2593 * - Entry is broken.2594 * - Entry is overridden by a loose ref.2595 * - Entry does not point at a valid object.2596 *2597 * In the first and third cases, also emit an error message because these2598 * are indications of repository corruption.2599 */2600static intcurate_packed_ref_fn(struct ref_entry *entry,void*cb_data)2601{2602struct string_list *refs_to_delete = cb_data;26032604if(entry->flag & REF_ISBROKEN) {2605/* This shouldn't happen to packed refs. */2606error("%sis broken!", entry->name);2607string_list_append(refs_to_delete, entry->name);2608return0;2609}2610if(!has_sha1_file(entry->u.value.sha1)) {2611unsigned char sha1[20];2612int flags;26132614if(read_ref_full(entry->name,0, sha1, &flags))2615/* We should at least have found the packed ref. */2616die("Internal error");2617if((flags & REF_ISSYMREF) || !(flags & REF_ISPACKED)) {2618/*2619 * This packed reference is overridden by a2620 * loose reference, so it is OK that its value2621 * is no longer valid; for example, it might2622 * refer to an object that has been garbage2623 * collected. For this purpose we don't even2624 * care whether the loose reference itself is2625 * invalid, broken, symbolic, etc. Silently2626 * remove the packed reference.2627 */2628string_list_append(refs_to_delete, entry->name);2629return0;2630}2631/*2632 * There is no overriding loose reference, so the fact2633 * that this reference doesn't refer to a valid object2634 * indicates some kind of repository corruption.2635 * Report the problem, then omit the reference from2636 * the output.2637 */2638error("%sdoes not point to a valid object!", entry->name);2639string_list_append(refs_to_delete, entry->name);2640return0;2641}26422643return0;2644}26452646intrepack_without_refs(const char**refnames,int n,struct strbuf *err)2647{2648struct ref_dir *packed;2649struct string_list refs_to_delete = STRING_LIST_INIT_DUP;2650struct string_list_item *ref_to_delete;2651int i, ret, removed =0;26522653assert(err);26542655/* Look for a packed ref */2656for(i =0; i < n; i++)2657if(get_packed_ref(refnames[i]))2658break;26592660/* Avoid locking if we have nothing to do */2661if(i == n)2662return0;/* no refname exists in packed refs */26632664if(lock_packed_refs(0)) {2665unable_to_lock_message(git_path("packed-refs"), errno, err);2666return-1;2667}2668 packed =get_packed_refs(&ref_cache);26692670/* Remove refnames from the cache */2671for(i =0; i < n; i++)2672if(remove_entry(packed, refnames[i]) != -1)2673 removed =1;2674if(!removed) {2675/*2676 * All packed entries disappeared while we were2677 * acquiring the lock.2678 */2679rollback_packed_refs();2680return0;2681}26822683/* Remove any other accumulated cruft */2684do_for_each_entry_in_dir(packed,0, curate_packed_ref_fn, &refs_to_delete);2685for_each_string_list_item(ref_to_delete, &refs_to_delete) {2686if(remove_entry(packed, ref_to_delete->string) == -1)2687die("internal error");2688}26892690/* Write what remains */2691 ret =commit_packed_refs();2692if(ret)2693strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2694strerror(errno));2695return ret;2696}26972698static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2699{2700assert(err);27012702if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2703/*2704 * loose. The loose file name is the same as the2705 * lockfile name, minus ".lock":2706 */2707char*loose_filename =get_locked_file_path(lock->lk);2708int res =unlink_or_msg(loose_filename, err);2709free(loose_filename);2710if(res)2711return1;2712}2713return0;2714}27152716intdelete_ref(const char*refname,const unsigned char*sha1,int delopt)2717{2718struct ref_transaction *transaction;2719struct strbuf err = STRBUF_INIT;27202721 transaction =ref_transaction_begin(&err);2722if(!transaction ||2723ref_transaction_delete(transaction, refname, sha1, delopt,2724 sha1 && !is_null_sha1(sha1), NULL, &err) ||2725ref_transaction_commit(transaction, &err)) {2726error("%s", err.buf);2727ref_transaction_free(transaction);2728strbuf_release(&err);2729return1;2730}2731ref_transaction_free(transaction);2732strbuf_release(&err);2733return0;2734}27352736/*2737 * People using contrib's git-new-workdir have .git/logs/refs ->2738 * /some/other/path/.git/logs/refs, and that may live on another device.2739 *2740 * IOW, to avoid cross device rename errors, the temporary renamed log must2741 * live into logs/refs.2742 */2743#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"27442745static intrename_tmp_log(const char*newrefname)2746{2747int attempts_remaining =4;27482749 retry:2750switch(safe_create_leading_directories(git_path("logs/%s", newrefname))) {2751case SCLD_OK:2752break;/* success */2753case SCLD_VANISHED:2754if(--attempts_remaining >0)2755goto retry;2756/* fall through */2757default:2758error("unable to create directory for%s", newrefname);2759return-1;2760}27612762if(rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2763if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2764/*2765 * rename(a, b) when b is an existing2766 * directory ought to result in ISDIR, but2767 * Solaris 5.8 gives ENOTDIR. Sheesh.2768 */2769if(remove_empty_directories(git_path("logs/%s", newrefname))) {2770error("Directory not empty: logs/%s", newrefname);2771return-1;2772}2773goto retry;2774}else if(errno == ENOENT && --attempts_remaining >0) {2775/*2776 * Maybe another process just deleted one of2777 * the directories in the path to newrefname.2778 * Try again from the beginning.2779 */2780goto retry;2781}else{2782error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2783 newrefname,strerror(errno));2784return-1;2785}2786}2787return0;2788}27892790static intrename_ref_available(const char*oldname,const char*newname)2791{2792struct string_list skip = STRING_LIST_INIT_NODUP;2793int ret;27942795string_list_insert(&skip, oldname);2796 ret =is_refname_available(newname, &skip,get_packed_refs(&ref_cache))2797&&is_refname_available(newname, &skip,get_loose_refs(&ref_cache));2798string_list_clear(&skip,0);2799return ret;2800}28012802static intwrite_ref_to_lockfile(struct ref_lock *lock,const unsigned char*sha1);2803static intcommit_ref_update(struct ref_lock *lock,2804const unsigned char*sha1,const char*logmsg);28052806intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2807{2808unsigned char sha1[20], orig_sha1[20];2809int flag =0, logmoved =0;2810struct ref_lock *lock;2811struct stat loginfo;2812int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2813const char*symref = NULL;28142815if(log &&S_ISLNK(loginfo.st_mode))2816returnerror("reflog for%sis a symlink", oldrefname);28172818 symref =resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,2819 orig_sha1, &flag);2820if(flag & REF_ISSYMREF)2821returnerror("refname%sis a symbolic ref, renaming it is not supported",2822 oldrefname);2823if(!symref)2824returnerror("refname%snot found", oldrefname);28252826if(!rename_ref_available(oldrefname, newrefname))2827return1;28282829if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2830returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2831 oldrefname,strerror(errno));28322833if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2834error("unable to delete old%s", oldrefname);2835goto rollback;2836}28372838if(!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2839delete_ref(newrefname, sha1, REF_NODEREF)) {2840if(errno==EISDIR) {2841if(remove_empty_directories(git_path("%s", newrefname))) {2842error("Directory not empty:%s", newrefname);2843goto rollback;2844}2845}else{2846error("unable to delete existing%s", newrefname);2847goto rollback;2848}2849}28502851if(log &&rename_tmp_log(newrefname))2852goto rollback;28532854 logmoved = log;28552856 lock =lock_ref_sha1_basic(newrefname, NULL, NULL,0, NULL);2857if(!lock) {2858error("unable to lock%sfor update", newrefname);2859goto rollback;2860}2861 lock->force_write =1;2862hashcpy(lock->old_sha1, orig_sha1);28632864if(write_ref_to_lockfile(lock, orig_sha1) ||2865commit_ref_update(lock, orig_sha1, logmsg)) {2866error("unable to write current sha1 into%s", newrefname);2867goto rollback;2868}28692870return0;28712872 rollback:2873 lock =lock_ref_sha1_basic(oldrefname, NULL, NULL,0, NULL);2874if(!lock) {2875error("unable to lock%sfor rollback", oldrefname);2876goto rollbacklog;2877}28782879 lock->force_write =1;2880 flag = log_all_ref_updates;2881 log_all_ref_updates =0;2882if(write_ref_to_lockfile(lock, orig_sha1) ||2883commit_ref_update(lock, orig_sha1, NULL))2884error("unable to write current sha1 into%s", oldrefname);2885 log_all_ref_updates = flag;28862887 rollbacklog:2888if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2889error("unable to restore logfile%sfrom%s:%s",2890 oldrefname, newrefname,strerror(errno));2891if(!logmoved && log &&2892rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2893error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2894 oldrefname,strerror(errno));28952896return1;2897}28982899intclose_ref(struct ref_lock *lock)2900{2901if(close_lock_file(lock->lk))2902return-1;2903 lock->lock_fd = -1;2904return0;2905}29062907intcommit_ref(struct ref_lock *lock)2908{2909if(commit_lock_file(lock->lk))2910return-1;2911 lock->lock_fd = -1;2912return0;2913}29142915voidunlock_ref(struct ref_lock *lock)2916{2917/* Do not free lock->lk -- atexit() still looks at them */2918if(lock->lk)2919rollback_lock_file(lock->lk);2920free(lock->ref_name);2921free(lock->orig_ref_name);2922free(lock);2923}29242925/*2926 * copy the reflog message msg to buf, which has been allocated sufficiently2927 * large, while cleaning up the whitespaces. Especially, convert LF to space,2928 * because reflog file is one line per entry.2929 */2930static intcopy_msg(char*buf,const char*msg)2931{2932char*cp = buf;2933char c;2934int wasspace =1;29352936*cp++ ='\t';2937while((c = *msg++)) {2938if(wasspace &&isspace(c))2939continue;2940 wasspace =isspace(c);2941if(wasspace)2942 c =' ';2943*cp++ = c;2944}2945while(buf < cp &&isspace(cp[-1]))2946 cp--;2947*cp++ ='\n';2948return cp - buf;2949}29502951/* This function must set a meaningful errno on failure */2952intlog_ref_setup(const char*refname,char*logfile,int bufsize)2953{2954int logfd, oflags = O_APPEND | O_WRONLY;29552956git_snpath(logfile, bufsize,"logs/%s", refname);2957if(log_all_ref_updates &&2958(starts_with(refname,"refs/heads/") ||2959starts_with(refname,"refs/remotes/") ||2960starts_with(refname,"refs/notes/") ||2961!strcmp(refname,"HEAD"))) {2962if(safe_create_leading_directories(logfile) <0) {2963int save_errno = errno;2964error("unable to create directory for%s", logfile);2965 errno = save_errno;2966return-1;2967}2968 oflags |= O_CREAT;2969}29702971 logfd =open(logfile, oflags,0666);2972if(logfd <0) {2973if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2974return0;29752976if(errno == EISDIR) {2977if(remove_empty_directories(logfile)) {2978int save_errno = errno;2979error("There are still logs under '%s'",2980 logfile);2981 errno = save_errno;2982return-1;2983}2984 logfd =open(logfile, oflags,0666);2985}29862987if(logfd <0) {2988int save_errno = errno;2989error("Unable to append to%s:%s", logfile,2990strerror(errno));2991 errno = save_errno;2992return-1;2993}2994}29952996adjust_shared_perm(logfile);2997close(logfd);2998return0;2999}30003001static intlog_ref_write(const char*refname,const unsigned char*old_sha1,3002const unsigned char*new_sha1,const char*msg)3003{3004int logfd, result, written, oflags = O_APPEND | O_WRONLY;3005unsigned maxlen, len;3006int msglen;3007char log_file[PATH_MAX];3008char*logrec;3009const char*committer;30103011if(log_all_ref_updates <0)3012 log_all_ref_updates = !is_bare_repository();30133014 result =log_ref_setup(refname, log_file,sizeof(log_file));3015if(result)3016return result;30173018 logfd =open(log_file, oflags);3019if(logfd <0)3020return0;3021 msglen = msg ?strlen(msg) :0;3022 committer =git_committer_info(0);3023 maxlen =strlen(committer) + msglen +100;3024 logrec =xmalloc(maxlen);3025 len =sprintf(logrec,"%s %s %s\n",3026sha1_to_hex(old_sha1),3027sha1_to_hex(new_sha1),3028 committer);3029if(msglen)3030 len +=copy_msg(logrec + len -1, msg) -1;3031 written = len <= maxlen ?write_in_full(logfd, logrec, len) : -1;3032free(logrec);3033if(written != len) {3034int save_errno = errno;3035close(logfd);3036error("Unable to append to%s", log_file);3037 errno = save_errno;3038return-1;3039}3040if(close(logfd)) {3041int save_errno = errno;3042error("Unable to append to%s", log_file);3043 errno = save_errno;3044return-1;3045}3046return0;3047}30483049intis_branch(const char*refname)3050{3051return!strcmp(refname,"HEAD") ||starts_with(refname,"refs/heads/");3052}30533054/*3055 * Write sha1 into the open lockfile, then close the lockfile. On3056 * errors, rollback the lockfile and set errno to reflect the problem.3057 */3058static intwrite_ref_to_lockfile(struct ref_lock *lock,3059const unsigned char*sha1)3060{3061static char term ='\n';3062struct object *o;30633064 o =parse_object(sha1);3065if(!o) {3066error("Trying to write ref%swith nonexistent object%s",3067 lock->ref_name,sha1_to_hex(sha1));3068unlock_ref(lock);3069 errno = EINVAL;3070return-1;3071}3072if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {3073error("Trying to write non-commit object%sto branch%s",3074sha1_to_hex(sha1), lock->ref_name);3075unlock_ref(lock);3076 errno = EINVAL;3077return-1;3078}3079if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||3080write_in_full(lock->lock_fd, &term,1) !=1||3081close_ref(lock) <0) {3082int save_errno = errno;3083error("Couldn't write%s", lock->lk->filename.buf);3084unlock_ref(lock);3085 errno = save_errno;3086return-1;3087}3088return0;3089}30903091/*3092 * Commit a change to a loose reference that has already been written3093 * to the loose reference lockfile. Also update the reflogs if3094 * necessary, using the specified lockmsg (which can be NULL).3095 */3096static intcommit_ref_update(struct ref_lock *lock,3097const unsigned char*sha1,const char*logmsg)3098{3099clear_loose_ref_cache(&ref_cache);3100if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||3101(strcmp(lock->ref_name, lock->orig_ref_name) &&3102log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {3103unlock_ref(lock);3104return-1;3105}3106if(strcmp(lock->orig_ref_name,"HEAD") !=0) {3107/*3108 * Special hack: If a branch is updated directly and HEAD3109 * points to it (may happen on the remote side of a push3110 * for example) then logically the HEAD reflog should be3111 * updated too.3112 * A generic solution implies reverse symref information,3113 * but finding all symrefs pointing to the given branch3114 * would be rather costly for this rare event (the direct3115 * update of a branch) to be worth it. So let's cheat and3116 * check with HEAD only which should cover 99% of all usage3117 * scenarios (even 100% of the default ones).3118 */3119unsigned char head_sha1[20];3120int head_flag;3121const char*head_ref;3122 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3123 head_sha1, &head_flag);3124if(head_ref && (head_flag & REF_ISSYMREF) &&3125!strcmp(head_ref, lock->ref_name))3126log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3127}3128if(commit_ref(lock)) {3129error("Couldn't set%s", lock->ref_name);3130unlock_ref(lock);3131return-1;3132}3133unlock_ref(lock);3134return0;3135}31363137intcreate_symref(const char*ref_target,const char*refs_heads_master,3138const char*logmsg)3139{3140const char*lockpath;3141char ref[1000];3142int fd, len, written;3143char*git_HEAD =git_pathdup("%s", ref_target);3144unsigned char old_sha1[20], new_sha1[20];31453146if(logmsg &&read_ref(ref_target, old_sha1))3147hashclr(old_sha1);31483149if(safe_create_leading_directories(git_HEAD) <0)3150returnerror("unable to create directory for%s", git_HEAD);31513152#ifndef NO_SYMLINK_HEAD3153if(prefer_symlink_refs) {3154unlink(git_HEAD);3155if(!symlink(refs_heads_master, git_HEAD))3156goto done;3157fprintf(stderr,"no symlink - falling back to symbolic ref\n");3158}3159#endif31603161 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);3162if(sizeof(ref) <= len) {3163error("refname too long:%s", refs_heads_master);3164goto error_free_return;3165}3166 lockpath =mkpath("%s.lock", git_HEAD);3167 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);3168if(fd <0) {3169error("Unable to open%sfor writing", lockpath);3170goto error_free_return;3171}3172 written =write_in_full(fd, ref, len);3173if(close(fd) !=0|| written != len) {3174error("Unable to write to%s", lockpath);3175goto error_unlink_return;3176}3177if(rename(lockpath, git_HEAD) <0) {3178error("Unable to create%s", git_HEAD);3179goto error_unlink_return;3180}3181if(adjust_shared_perm(git_HEAD)) {3182error("Unable to fix permissions on%s", lockpath);3183 error_unlink_return:3184unlink_or_warn(lockpath);3185 error_free_return:3186free(git_HEAD);3187return-1;3188}31893190#ifndef NO_SYMLINK_HEAD3191 done:3192#endif3193if(logmsg && !read_ref(refs_heads_master, new_sha1))3194log_ref_write(ref_target, old_sha1, new_sha1, logmsg);31953196free(git_HEAD);3197return0;3198}31993200struct read_ref_at_cb {3201const char*refname;3202unsigned long at_time;3203int cnt;3204int reccnt;3205unsigned char*sha1;3206int found_it;32073208unsigned char osha1[20];3209unsigned char nsha1[20];3210int tz;3211unsigned long date;3212char**msg;3213unsigned long*cutoff_time;3214int*cutoff_tz;3215int*cutoff_cnt;3216};32173218static intread_ref_at_ent(unsigned char*osha1,unsigned char*nsha1,3219const char*email,unsigned long timestamp,int tz,3220const char*message,void*cb_data)3221{3222struct read_ref_at_cb *cb = cb_data;32233224 cb->reccnt++;3225 cb->tz = tz;3226 cb->date = timestamp;32273228if(timestamp <= cb->at_time || cb->cnt ==0) {3229if(cb->msg)3230*cb->msg =xstrdup(message);3231if(cb->cutoff_time)3232*cb->cutoff_time = timestamp;3233if(cb->cutoff_tz)3234*cb->cutoff_tz = tz;3235if(cb->cutoff_cnt)3236*cb->cutoff_cnt = cb->reccnt -1;3237/*3238 * we have not yet updated cb->[n|o]sha1 so they still3239 * hold the values for the previous record.3240 */3241if(!is_null_sha1(cb->osha1)) {3242hashcpy(cb->sha1, nsha1);3243if(hashcmp(cb->osha1, nsha1))3244warning("Log for ref%shas gap after%s.",3245 cb->refname,show_date(cb->date, cb->tz, DATE_RFC2822));3246}3247else if(cb->date == cb->at_time)3248hashcpy(cb->sha1, nsha1);3249else if(hashcmp(nsha1, cb->sha1))3250warning("Log for ref%sunexpectedly ended on%s.",3251 cb->refname,show_date(cb->date, cb->tz,3252 DATE_RFC2822));3253hashcpy(cb->osha1, osha1);3254hashcpy(cb->nsha1, nsha1);3255 cb->found_it =1;3256return1;3257}3258hashcpy(cb->osha1, osha1);3259hashcpy(cb->nsha1, nsha1);3260if(cb->cnt >0)3261 cb->cnt--;3262return0;3263}32643265static intread_ref_at_ent_oldest(unsigned char*osha1,unsigned char*nsha1,3266const char*email,unsigned long timestamp,3267int tz,const char*message,void*cb_data)3268{3269struct read_ref_at_cb *cb = cb_data;32703271if(cb->msg)3272*cb->msg =xstrdup(message);3273if(cb->cutoff_time)3274*cb->cutoff_time = timestamp;3275if(cb->cutoff_tz)3276*cb->cutoff_tz = tz;3277if(cb->cutoff_cnt)3278*cb->cutoff_cnt = cb->reccnt;3279hashcpy(cb->sha1, osha1);3280if(is_null_sha1(cb->sha1))3281hashcpy(cb->sha1, nsha1);3282/* We just want the first entry */3283return1;3284}32853286intread_ref_at(const char*refname,unsigned int flags,unsigned long at_time,int cnt,3287unsigned char*sha1,char**msg,3288unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)3289{3290struct read_ref_at_cb cb;32913292memset(&cb,0,sizeof(cb));3293 cb.refname = refname;3294 cb.at_time = at_time;3295 cb.cnt = cnt;3296 cb.msg = msg;3297 cb.cutoff_time = cutoff_time;3298 cb.cutoff_tz = cutoff_tz;3299 cb.cutoff_cnt = cutoff_cnt;3300 cb.sha1 = sha1;33013302for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);33033304if(!cb.reccnt) {3305if(flags & GET_SHA1_QUIETLY)3306exit(128);3307else3308die("Log for%sis empty.", refname);3309}3310if(cb.found_it)3311return0;33123313for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);33143315return1;3316}33173318intreflog_exists(const char*refname)3319{3320struct stat st;33213322return!lstat(git_path("logs/%s", refname), &st) &&3323S_ISREG(st.st_mode);3324}33253326intdelete_reflog(const char*refname)3327{3328returnremove_path(git_path("logs/%s", refname));3329}33303331static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3332{3333unsigned char osha1[20], nsha1[20];3334char*email_end, *message;3335unsigned long timestamp;3336int tz;33373338/* old SP new SP name <email> SP time TAB msg LF */3339if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3340get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3341get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3342!(email_end =strchr(sb->buf +82,'>')) ||3343 email_end[1] !=' '||3344!(timestamp =strtoul(email_end +2, &message,10)) ||3345!message || message[0] !=' '||3346(message[1] !='+'&& message[1] !='-') ||3347!isdigit(message[2]) || !isdigit(message[3]) ||3348!isdigit(message[4]) || !isdigit(message[5]))3349return0;/* corrupt? */3350 email_end[1] ='\0';3351 tz =strtol(message +1, NULL,10);3352if(message[6] !='\t')3353 message +=6;3354else3355 message +=7;3356returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3357}33583359static char*find_beginning_of_line(char*bob,char*scan)3360{3361while(bob < scan && *(--scan) !='\n')3362;/* keep scanning backwards */3363/*3364 * Return either beginning of the buffer, or LF at the end of3365 * the previous line.3366 */3367return scan;3368}33693370intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3371{3372struct strbuf sb = STRBUF_INIT;3373FILE*logfp;3374long pos;3375int ret =0, at_tail =1;33763377 logfp =fopen(git_path("logs/%s", refname),"r");3378if(!logfp)3379return-1;33803381/* Jump to the end */3382if(fseek(logfp,0, SEEK_END) <0)3383returnerror("cannot seek back reflog for%s:%s",3384 refname,strerror(errno));3385 pos =ftell(logfp);3386while(!ret &&0< pos) {3387int cnt;3388size_t nread;3389char buf[BUFSIZ];3390char*endp, *scanp;33913392/* Fill next block from the end */3393 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3394if(fseek(logfp, pos - cnt, SEEK_SET))3395returnerror("cannot seek back reflog for%s:%s",3396 refname,strerror(errno));3397 nread =fread(buf, cnt,1, logfp);3398if(nread !=1)3399returnerror("cannot read%dbytes from reflog for%s:%s",3400 cnt, refname,strerror(errno));3401 pos -= cnt;34023403 scanp = endp = buf + cnt;3404if(at_tail && scanp[-1] =='\n')3405/* Looking at the final LF at the end of the file */3406 scanp--;3407 at_tail =0;34083409while(buf < scanp) {3410/*3411 * terminating LF of the previous line, or the beginning3412 * of the buffer.3413 */3414char*bp;34153416 bp =find_beginning_of_line(buf, scanp);34173418if(*bp =='\n') {3419/*3420 * The newline is the end of the previous line,3421 * so we know we have complete line starting3422 * at (bp + 1). Prefix it onto any prior data3423 * we collected for the line and process it.3424 */3425strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3426 scanp = bp;3427 endp = bp +1;3428 ret =show_one_reflog_ent(&sb, fn, cb_data);3429strbuf_reset(&sb);3430if(ret)3431break;3432}else if(!pos) {3433/*3434 * We are at the start of the buffer, and the3435 * start of the file; there is no previous3436 * line, and we have everything for this one.3437 * Process it, and we can end the loop.3438 */3439strbuf_splice(&sb,0,0, buf, endp - buf);3440 ret =show_one_reflog_ent(&sb, fn, cb_data);3441strbuf_reset(&sb);3442break;3443}34443445if(bp == buf) {3446/*3447 * We are at the start of the buffer, and there3448 * is more file to read backwards. Which means3449 * we are in the middle of a line. Note that we3450 * may get here even if *bp was a newline; that3451 * just means we are at the exact end of the3452 * previous line, rather than some spot in the3453 * middle.3454 *3455 * Save away what we have to be combined with3456 * the data from the next read.3457 */3458strbuf_splice(&sb,0,0, buf, endp - buf);3459break;3460}3461}34623463}3464if(!ret && sb.len)3465die("BUG: reverse reflog parser had leftover data");34663467fclose(logfp);3468strbuf_release(&sb);3469return ret;3470}34713472intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3473{3474FILE*logfp;3475struct strbuf sb = STRBUF_INIT;3476int ret =0;34773478 logfp =fopen(git_path("logs/%s", refname),"r");3479if(!logfp)3480return-1;34813482while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3483 ret =show_one_reflog_ent(&sb, fn, cb_data);3484fclose(logfp);3485strbuf_release(&sb);3486return ret;3487}3488/*3489 * Call fn for each reflog in the namespace indicated by name. name3490 * must be empty or end with '/'. Name will be used as a scratch3491 * space, but its contents will be restored before return.3492 */3493static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3494{3495DIR*d =opendir(git_path("logs/%s", name->buf));3496int retval =0;3497struct dirent *de;3498int oldlen = name->len;34993500if(!d)3501return name->len ? errno :0;35023503while((de =readdir(d)) != NULL) {3504struct stat st;35053506if(de->d_name[0] =='.')3507continue;3508if(ends_with(de->d_name,".lock"))3509continue;3510strbuf_addstr(name, de->d_name);3511if(stat(git_path("logs/%s", name->buf), &st) <0) {3512;/* silently ignore */3513}else{3514if(S_ISDIR(st.st_mode)) {3515strbuf_addch(name,'/');3516 retval =do_for_each_reflog(name, fn, cb_data);3517}else{3518unsigned char sha1[20];3519if(read_ref_full(name->buf,0, sha1, NULL))3520 retval =error("bad ref for%s", name->buf);3521else3522 retval =fn(name->buf, sha1,0, cb_data);3523}3524if(retval)3525break;3526}3527strbuf_setlen(name, oldlen);3528}3529closedir(d);3530return retval;3531}35323533intfor_each_reflog(each_ref_fn fn,void*cb_data)3534{3535int retval;3536struct strbuf name;3537strbuf_init(&name, PATH_MAX);3538 retval =do_for_each_reflog(&name, fn, cb_data);3539strbuf_release(&name);3540return retval;3541}35423543/**3544 * Information needed for a single ref update. Set new_sha1 to the3545 * new value or to zero to delete the ref. To check the old value3546 * while locking the ref, set have_old to 1 and set old_sha1 to the3547 * value or to zero to ensure the ref does not exist before update.3548 */3549struct ref_update {3550unsigned char new_sha1[20];3551unsigned char old_sha1[20];3552int flags;/* REF_NODEREF? */3553int have_old;/* 1 if old_sha1 is valid, 0 otherwise */3554struct ref_lock *lock;3555int type;3556char*msg;3557const char refname[FLEX_ARRAY];3558};35593560/*3561 * Transaction states.3562 * OPEN: The transaction is in a valid state and can accept new updates.3563 * An OPEN transaction can be committed.3564 * CLOSED: A closed transaction is no longer active and no other operations3565 * than free can be used on it in this state.3566 * A transaction can either become closed by successfully committing3567 * an active transaction or if there is a failure while building3568 * the transaction thus rendering it failed/inactive.3569 */3570enum ref_transaction_state {3571 REF_TRANSACTION_OPEN =0,3572 REF_TRANSACTION_CLOSED =13573};35743575/*3576 * Data structure for holding a reference transaction, which can3577 * consist of checks and updates to multiple references, carried out3578 * as atomically as possible. This structure is opaque to callers.3579 */3580struct ref_transaction {3581struct ref_update **updates;3582size_t alloc;3583size_t nr;3584enum ref_transaction_state state;3585};35863587struct ref_transaction *ref_transaction_begin(struct strbuf *err)3588{3589assert(err);35903591returnxcalloc(1,sizeof(struct ref_transaction));3592}35933594voidref_transaction_free(struct ref_transaction *transaction)3595{3596int i;35973598if(!transaction)3599return;36003601for(i =0; i < transaction->nr; i++) {3602free(transaction->updates[i]->msg);3603free(transaction->updates[i]);3604}3605free(transaction->updates);3606free(transaction);3607}36083609static struct ref_update *add_update(struct ref_transaction *transaction,3610const char*refname)3611{3612size_t len =strlen(refname);3613struct ref_update *update =xcalloc(1,sizeof(*update) + len +1);36143615strcpy((char*)update->refname, refname);3616ALLOC_GROW(transaction->updates, transaction->nr +1, transaction->alloc);3617 transaction->updates[transaction->nr++] = update;3618return update;3619}36203621intref_transaction_update(struct ref_transaction *transaction,3622const char*refname,3623const unsigned char*new_sha1,3624const unsigned char*old_sha1,3625int flags,int have_old,const char*msg,3626struct strbuf *err)3627{3628struct ref_update *update;36293630assert(err);36313632if(transaction->state != REF_TRANSACTION_OPEN)3633die("BUG: update called for transaction that is not open");36343635if(have_old && !old_sha1)3636die("BUG: have_old is true but old_sha1 is NULL");36373638if(!is_null_sha1(new_sha1) &&3639check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3640strbuf_addf(err,"refusing to update ref with bad name%s",3641 refname);3642return-1;3643}36443645 update =add_update(transaction, refname);3646hashcpy(update->new_sha1, new_sha1);3647 update->flags = flags;3648 update->have_old = have_old;3649if(have_old)3650hashcpy(update->old_sha1, old_sha1);3651if(msg)3652 update->msg =xstrdup(msg);3653return0;3654}36553656intref_transaction_create(struct ref_transaction *transaction,3657const char*refname,3658const unsigned char*new_sha1,3659int flags,const char*msg,3660struct strbuf *err)3661{3662struct ref_update *update;36633664assert(err);36653666if(transaction->state != REF_TRANSACTION_OPEN)3667die("BUG: create called for transaction that is not open");36683669if(!new_sha1 ||is_null_sha1(new_sha1))3670die("BUG: create ref with null new_sha1");36713672if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3673strbuf_addf(err,"refusing to create ref with bad name%s",3674 refname);3675return-1;3676}36773678 update =add_update(transaction, refname);36793680hashcpy(update->new_sha1, new_sha1);3681hashclr(update->old_sha1);3682 update->flags = flags;3683 update->have_old =1;3684if(msg)3685 update->msg =xstrdup(msg);3686return0;3687}36883689intref_transaction_delete(struct ref_transaction *transaction,3690const char*refname,3691const unsigned char*old_sha1,3692int flags,int have_old,const char*msg,3693struct strbuf *err)3694{3695struct ref_update *update;36963697assert(err);36983699if(transaction->state != REF_TRANSACTION_OPEN)3700die("BUG: delete called for transaction that is not open");37013702if(have_old && !old_sha1)3703die("BUG: have_old is true but old_sha1 is NULL");37043705 update =add_update(transaction, refname);3706 update->flags = flags;3707 update->have_old = have_old;3708if(have_old) {3709assert(!is_null_sha1(old_sha1));3710hashcpy(update->old_sha1, old_sha1);3711}3712if(msg)3713 update->msg =xstrdup(msg);3714return0;3715}37163717intupdate_ref(const char*action,const char*refname,3718const unsigned char*sha1,const unsigned char*oldval,3719int flags,enum action_on_err onerr)3720{3721struct ref_transaction *t;3722struct strbuf err = STRBUF_INIT;37233724 t =ref_transaction_begin(&err);3725if(!t ||3726ref_transaction_update(t, refname, sha1, oldval, flags,3727!!oldval, action, &err) ||3728ref_transaction_commit(t, &err)) {3729const char*str ="update_ref failed for ref '%s':%s";37303731ref_transaction_free(t);3732switch(onerr) {3733case UPDATE_REFS_MSG_ON_ERR:3734error(str, refname, err.buf);3735break;3736case UPDATE_REFS_DIE_ON_ERR:3737die(str, refname, err.buf);3738break;3739case UPDATE_REFS_QUIET_ON_ERR:3740break;3741}3742strbuf_release(&err);3743return1;3744}3745strbuf_release(&err);3746ref_transaction_free(t);3747return0;3748}37493750static intref_update_compare(const void*r1,const void*r2)3751{3752const struct ref_update *const*u1 = r1;3753const struct ref_update *const*u2 = r2;3754returnstrcmp((*u1)->refname, (*u2)->refname);3755}37563757static intref_update_reject_duplicates(struct ref_update **updates,int n,3758struct strbuf *err)3759{3760int i;37613762assert(err);37633764for(i =1; i < n; i++)3765if(!strcmp(updates[i -1]->refname, updates[i]->refname)) {3766strbuf_addf(err,3767"Multiple updates for ref '%s' not allowed.",3768 updates[i]->refname);3769return1;3770}3771return0;3772}37733774intref_transaction_commit(struct ref_transaction *transaction,3775struct strbuf *err)3776{3777int ret =0, delnum =0, i;3778const char**delnames;3779int n = transaction->nr;3780struct ref_update **updates = transaction->updates;37813782assert(err);37833784if(transaction->state != REF_TRANSACTION_OPEN)3785die("BUG: commit called for transaction that is not open");37863787if(!n) {3788 transaction->state = REF_TRANSACTION_CLOSED;3789return0;3790}37913792/* Allocate work space */3793 delnames =xmalloc(sizeof(*delnames) * n);37943795/* Copy, sort, and reject duplicate refs */3796qsort(updates, n,sizeof(*updates), ref_update_compare);3797if(ref_update_reject_duplicates(updates, n, err)) {3798 ret = TRANSACTION_GENERIC_ERROR;3799goto cleanup;3800}38013802/* Acquire all locks while verifying old values */3803for(i =0; i < n; i++) {3804struct ref_update *update = updates[i];38053806if(is_null_sha1(update->new_sha1))3807 update->flags |= REF_DELETING;3808 update->lock =lock_ref_sha1_basic(update->refname,3809(update->have_old ?3810 update->old_sha1 :3811 NULL),3812 NULL,3813 update->flags,3814&update->type);3815if(!update->lock) {3816 ret = (errno == ENOTDIR)3817? TRANSACTION_NAME_CONFLICT3818: TRANSACTION_GENERIC_ERROR;3819strbuf_addf(err,"Cannot lock the ref '%s'.",3820 update->refname);3821goto cleanup;3822}3823}38243825/* Perform updates first so live commits remain referenced */3826for(i =0; i < n; i++) {3827struct ref_update *update = updates[i];38283829if(!(update->flags & REF_DELETING)) {3830if(!update->lock->force_write &&3831!hashcmp(update->lock->old_sha1, update->new_sha1)) {3832unlock_ref(update->lock);3833 update->lock = NULL;3834}else if(write_ref_to_lockfile(update->lock, update->new_sha1) ||3835commit_ref_update(update->lock, update->new_sha1, update->msg)) {3836 update->lock = NULL;/* freed by the above calls */3837strbuf_addf(err,"Cannot update the ref '%s'.",3838 update->refname);3839 ret = TRANSACTION_GENERIC_ERROR;3840goto cleanup;3841}else{3842/* freed by the above calls: */3843 update->lock = NULL;3844}3845}3846}38473848/* Perform deletes now that updates are safely completed */3849for(i =0; i < n; i++) {3850struct ref_update *update = updates[i];38513852if(update->lock) {3853if(delete_ref_loose(update->lock, update->type, err)) {3854 ret = TRANSACTION_GENERIC_ERROR;3855goto cleanup;3856}38573858if(!(update->flags & REF_ISPRUNING))3859 delnames[delnum++] = update->lock->ref_name;3860}3861}38623863if(repack_without_refs(delnames, delnum, err)) {3864 ret = TRANSACTION_GENERIC_ERROR;3865goto cleanup;3866}3867for(i =0; i < delnum; i++)3868unlink_or_warn(git_path("logs/%s", delnames[i]));3869clear_loose_ref_cache(&ref_cache);38703871cleanup:3872 transaction->state = REF_TRANSACTION_CLOSED;38733874for(i =0; i < n; i++)3875if(updates[i]->lock)3876unlock_ref(updates[i]->lock);3877free(delnames);3878return ret;3879}38803881char*shorten_unambiguous_ref(const char*refname,int strict)3882{3883int i;3884static char**scanf_fmts;3885static int nr_rules;3886char*short_name;38873888if(!nr_rules) {3889/*3890 * Pre-generate scanf formats from ref_rev_parse_rules[].3891 * Generate a format suitable for scanf from a3892 * ref_rev_parse_rules rule by interpolating "%s" at the3893 * location of the "%.*s".3894 */3895size_t total_len =0;3896size_t offset =0;38973898/* the rule list is NULL terminated, count them first */3899for(nr_rules =0; ref_rev_parse_rules[nr_rules]; nr_rules++)3900/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3901 total_len +=strlen(ref_rev_parse_rules[nr_rules]) -2+1;39023903 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);39043905 offset =0;3906for(i =0; i < nr_rules; i++) {3907assert(offset < total_len);3908 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules] + offset;3909 offset +=snprintf(scanf_fmts[i], total_len - offset,3910 ref_rev_parse_rules[i],2,"%s") +1;3911}3912}39133914/* bail out if there are no rules */3915if(!nr_rules)3916returnxstrdup(refname);39173918/* buffer for scanf result, at most refname must fit */3919 short_name =xstrdup(refname);39203921/* skip first rule, it will always match */3922for(i = nr_rules -1; i >0; --i) {3923int j;3924int rules_to_fail = i;3925int short_name_len;39263927if(1!=sscanf(refname, scanf_fmts[i], short_name))3928continue;39293930 short_name_len =strlen(short_name);39313932/*3933 * in strict mode, all (except the matched one) rules3934 * must fail to resolve to a valid non-ambiguous ref3935 */3936if(strict)3937 rules_to_fail = nr_rules;39383939/*3940 * check if the short name resolves to a valid ref,3941 * but use only rules prior to the matched one3942 */3943for(j =0; j < rules_to_fail; j++) {3944const char*rule = ref_rev_parse_rules[j];3945char refname[PATH_MAX];39463947/* skip matched rule */3948if(i == j)3949continue;39503951/*3952 * the short name is ambiguous, if it resolves3953 * (with this previous rule) to a valid ref3954 * read_ref() returns 0 on success3955 */3956mksnpath(refname,sizeof(refname),3957 rule, short_name_len, short_name);3958if(ref_exists(refname))3959break;3960}39613962/*3963 * short name is non-ambiguous if all previous rules3964 * haven't resolved to a valid ref3965 */3966if(j == rules_to_fail)3967return short_name;3968}39693970free(short_name);3971returnxstrdup(refname);3972}39733974static struct string_list *hide_refs;39753976intparse_hide_refs_config(const char*var,const char*value,const char*section)3977{3978if(!strcmp("transfer.hiderefs", var) ||3979/* NEEDSWORK: use parse_config_key() once both are merged */3980(starts_with(var, section) && var[strlen(section)] =='.'&&3981!strcmp(var +strlen(section),".hiderefs"))) {3982char*ref;3983int len;39843985if(!value)3986returnconfig_error_nonbool(var);3987 ref =xstrdup(value);3988 len =strlen(ref);3989while(len && ref[len -1] =='/')3990 ref[--len] ='\0';3991if(!hide_refs) {3992 hide_refs =xcalloc(1,sizeof(*hide_refs));3993 hide_refs->strdup_strings =1;3994}3995string_list_append(hide_refs, ref);3996}3997return0;3998}39994000intref_is_hidden(const char*refname)4001{4002struct string_list_item *item;40034004if(!hide_refs)4005return0;4006for_each_string_list_item(item, hide_refs) {4007int len;4008if(!starts_with(refname, item->string))4009continue;4010 len =strlen(item->string);4011if(!refname[len] || refname[len] =='/')4012return1;4013}4014return0;4015}