1#include"cache.h" 2#include"lockfile.h" 3#include"refs.h" 4#include"object.h" 5#include"tag.h" 6#include"dir.h" 7#include"string-list.h" 8 9struct ref_lock { 10char*ref_name; 11char*orig_ref_name; 12struct lock_file *lk; 13unsigned char old_sha1[20]; 14int lock_fd; 15}; 16 17/* 18 * How to handle various characters in refnames: 19 * 0: An acceptable character for refs 20 * 1: End-of-component 21 * 2: ., look for a preceding . to reject .. in refs 22 * 3: {, look for a preceding @ to reject @{ in refs 23 * 4: A bad character: ASCII control characters, "~", "^", ":" or SP 24 */ 25static unsigned char refname_disposition[256] = { 261,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 274,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4, 284,0,0,0,0,0,0,0,0,0,4,0,0,0,2,1, 290,0,0,0,0,0,0,0,0,0,4,0,0,0,0,4, 300,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 310,0,0,0,0,0,0,0,0,0,0,4,4,0,4,0, 320,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 330,0,0,0,0,0,0,0,0,0,0,3,0,0,4,4 34}; 35 36/* 37 * Flag passed to lock_ref_sha1_basic() telling it to tolerate broken 38 * refs (i.e., because the reference is about to be deleted anyway). 39 */ 40#define REF_DELETING 0x02 41 42/* 43 * Used as a flag in ref_update::flags when a loose ref is being 44 * pruned. 45 */ 46#define REF_ISPRUNING 0x04 47 48/* 49 * Used as a flag in ref_update::flags when the reference should be 50 * updated to new_sha1. 51 */ 52#define REF_HAVE_NEW 0x08 53 54/* 55 * Used as a flag in ref_update::flags when old_sha1 should be 56 * checked. 57 */ 58#define REF_HAVE_OLD 0x10 59 60/* 61 * Try to read one refname component from the front of refname. 62 * Return the length of the component found, or -1 if the component is 63 * not legal. It is legal if it is something reasonable to have under 64 * ".git/refs/"; We do not like it if: 65 * 66 * - any path component of it begins with ".", or 67 * - it has double dots "..", or 68 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or 69 * - it ends with a "/". 70 * - it ends with ".lock" 71 * - it contains a "\" (backslash) 72 */ 73static intcheck_refname_component(const char*refname,int flags) 74{ 75const char*cp; 76char last ='\0'; 77 78for(cp = refname; ; cp++) { 79int ch = *cp &255; 80unsigned char disp = refname_disposition[ch]; 81switch(disp) { 82case1: 83goto out; 84case2: 85if(last =='.') 86return-1;/* Refname contains "..". */ 87break; 88case3: 89if(last =='@') 90return-1;/* Refname contains "@{". */ 91break; 92case4: 93return-1; 94} 95 last = ch; 96} 97out: 98if(cp == refname) 99return0;/* Component has zero length. */ 100if(refname[0] =='.') 101return-1;/* Component starts with '.'. */ 102if(cp - refname >= LOCK_SUFFIX_LEN && 103!memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN)) 104return-1;/* Refname ends with ".lock". */ 105return cp - refname; 106} 107 108intcheck_refname_format(const char*refname,int flags) 109{ 110int component_len, component_count =0; 111 112if(!strcmp(refname,"@")) 113/* Refname is a single character '@'. */ 114return-1; 115 116while(1) { 117/* We are at the start of a path component. */ 118 component_len =check_refname_component(refname, flags); 119if(component_len <=0) { 120if((flags & REFNAME_REFSPEC_PATTERN) && 121 refname[0] =='*'&& 122(refname[1] =='\0'|| refname[1] =='/')) { 123/* Accept one wildcard as a full refname component. */ 124 flags &= ~REFNAME_REFSPEC_PATTERN; 125 component_len =1; 126}else{ 127return-1; 128} 129} 130 component_count++; 131if(refname[component_len] =='\0') 132break; 133/* Skip to next component. */ 134 refname += component_len +1; 135} 136 137if(refname[component_len -1] =='.') 138return-1;/* Refname ends with '.'. */ 139if(!(flags & REFNAME_ALLOW_ONELEVEL) && component_count <2) 140return-1;/* Refname has only one component. */ 141return0; 142} 143 144struct ref_entry; 145 146/* 147 * Information used (along with the information in ref_entry) to 148 * describe a single cached reference. This data structure only 149 * occurs embedded in a union in struct ref_entry, and only when 150 * (ref_entry->flag & REF_DIR) is zero. 151 */ 152struct ref_value { 153/* 154 * The name of the object to which this reference resolves 155 * (which may be a tag object). If REF_ISBROKEN, this is 156 * null. If REF_ISSYMREF, then this is the name of the object 157 * referred to by the last reference in the symlink chain. 158 */ 159unsigned char sha1[20]; 160 161/* 162 * If REF_KNOWS_PEELED, then this field holds the peeled value 163 * of this reference, or null if the reference is known not to 164 * be peelable. See the documentation for peel_ref() for an 165 * exact definition of "peelable". 166 */ 167unsigned char peeled[20]; 168}; 169 170struct ref_cache; 171 172/* 173 * Information used (along with the information in ref_entry) to 174 * describe a level in the hierarchy of references. This data 175 * structure only occurs embedded in a union in struct ref_entry, and 176 * only when (ref_entry.flag & REF_DIR) is set. In that case, 177 * (ref_entry.flag & REF_INCOMPLETE) determines whether the references 178 * in the directory have already been read: 179 * 180 * (ref_entry.flag & REF_INCOMPLETE) unset -- a directory of loose 181 * or packed references, already read. 182 * 183 * (ref_entry.flag & REF_INCOMPLETE) set -- a directory of loose 184 * references that hasn't been read yet (nor has any of its 185 * subdirectories). 186 * 187 * Entries within a directory are stored within a growable array of 188 * pointers to ref_entries (entries, nr, alloc). Entries 0 <= i < 189 * sorted are sorted by their component name in strcmp() order and the 190 * remaining entries are unsorted. 191 * 192 * Loose references are read lazily, one directory at a time. When a 193 * directory of loose references is read, then all of the references 194 * in that directory are stored, and REF_INCOMPLETE stubs are created 195 * for any subdirectories, but the subdirectories themselves are not 196 * read. The reading is triggered by get_ref_dir(). 197 */ 198struct ref_dir { 199int nr, alloc; 200 201/* 202 * Entries with index 0 <= i < sorted are sorted by name. New 203 * entries are appended to the list unsorted, and are sorted 204 * only when required; thus we avoid the need to sort the list 205 * after the addition of every reference. 206 */ 207int sorted; 208 209/* A pointer to the ref_cache that contains this ref_dir. */ 210struct ref_cache *ref_cache; 211 212struct ref_entry **entries; 213}; 214 215/* 216 * Bit values for ref_entry::flag. REF_ISSYMREF=0x01, 217 * REF_ISPACKED=0x02, REF_ISBROKEN=0x04 and REF_BAD_NAME=0x08 are 218 * public values; see refs.h. 219 */ 220 221/* 222 * The field ref_entry->u.value.peeled of this value entry contains 223 * the correct peeled value for the reference, which might be 224 * null_sha1 if the reference is not a tag or if it is broken. 225 */ 226#define REF_KNOWS_PEELED 0x10 227 228/* ref_entry represents a directory of references */ 229#define REF_DIR 0x20 230 231/* 232 * Entry has not yet been read from disk (used only for REF_DIR 233 * entries representing loose references) 234 */ 235#define REF_INCOMPLETE 0x40 236 237/* 238 * A ref_entry represents either a reference or a "subdirectory" of 239 * references. 240 * 241 * Each directory in the reference namespace is represented by a 242 * ref_entry with (flags & REF_DIR) set and containing a subdir member 243 * that holds the entries in that directory that have been read so 244 * far. If (flags & REF_INCOMPLETE) is set, then the directory and 245 * its subdirectories haven't been read yet. REF_INCOMPLETE is only 246 * used for loose reference directories. 247 * 248 * References are represented by a ref_entry with (flags & REF_DIR) 249 * unset and a value member that describes the reference's value. The 250 * flag member is at the ref_entry level, but it is also needed to 251 * interpret the contents of the value field (in other words, a 252 * ref_value object is not very much use without the enclosing 253 * ref_entry). 254 * 255 * Reference names cannot end with slash and directories' names are 256 * always stored with a trailing slash (except for the top-level 257 * directory, which is always denoted by ""). This has two nice 258 * consequences: (1) when the entries in each subdir are sorted 259 * lexicographically by name (as they usually are), the references in 260 * a whole tree can be generated in lexicographic order by traversing 261 * the tree in left-to-right, depth-first order; (2) the names of 262 * references and subdirectories cannot conflict, and therefore the 263 * presence of an empty subdirectory does not block the creation of a 264 * similarly-named reference. (The fact that reference names with the 265 * same leading components can conflict *with each other* is a 266 * separate issue that is regulated by is_refname_available().) 267 * 268 * Please note that the name field contains the fully-qualified 269 * reference (or subdirectory) name. Space could be saved by only 270 * storing the relative names. But that would require the full names 271 * to be generated on the fly when iterating in do_for_each_ref(), and 272 * would break callback functions, who have always been able to assume 273 * that the name strings that they are passed will not be freed during 274 * the iteration. 275 */ 276struct ref_entry { 277unsigned char flag;/* ISSYMREF? ISPACKED? */ 278union{ 279struct ref_value value;/* if not (flags&REF_DIR) */ 280struct ref_dir subdir;/* if (flags&REF_DIR) */ 281} u; 282/* 283 * The full name of the reference (e.g., "refs/heads/master") 284 * or the full name of the directory with a trailing slash 285 * (e.g., "refs/heads/"): 286 */ 287char name[FLEX_ARRAY]; 288}; 289 290static voidread_loose_refs(const char*dirname,struct ref_dir *dir); 291 292static struct ref_dir *get_ref_dir(struct ref_entry *entry) 293{ 294struct ref_dir *dir; 295assert(entry->flag & REF_DIR); 296 dir = &entry->u.subdir; 297if(entry->flag & REF_INCOMPLETE) { 298read_loose_refs(entry->name, dir); 299 entry->flag &= ~REF_INCOMPLETE; 300} 301return dir; 302} 303 304/* 305 * Check if a refname is safe. 306 * For refs that start with "refs/" we consider it safe as long they do 307 * not try to resolve to outside of refs/. 308 * 309 * For all other refs we only consider them safe iff they only contain 310 * upper case characters and '_' (like "HEAD" AND "MERGE_HEAD", and not like 311 * "config"). 312 */ 313static intrefname_is_safe(const char*refname) 314{ 315if(starts_with(refname,"refs/")) { 316char*buf; 317int result; 318 319 buf =xmalloc(strlen(refname) +1); 320/* 321 * Does the refname try to escape refs/? 322 * For example: refs/foo/../bar is safe but refs/foo/../../bar 323 * is not. 324 */ 325 result = !normalize_path_copy(buf, refname +strlen("refs/")); 326free(buf); 327return result; 328} 329while(*refname) { 330if(!isupper(*refname) && *refname !='_') 331return0; 332 refname++; 333} 334return1; 335} 336 337static struct ref_entry *create_ref_entry(const char*refname, 338const unsigned char*sha1,int flag, 339int check_name) 340{ 341int len; 342struct ref_entry *ref; 343 344if(check_name && 345check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) 346die("Reference has invalid format: '%s'", refname); 347 len =strlen(refname) +1; 348 ref =xmalloc(sizeof(struct ref_entry) + len); 349hashcpy(ref->u.value.sha1, sha1); 350hashclr(ref->u.value.peeled); 351memcpy(ref->name, refname, len); 352 ref->flag = flag; 353return ref; 354} 355 356static voidclear_ref_dir(struct ref_dir *dir); 357 358static voidfree_ref_entry(struct ref_entry *entry) 359{ 360if(entry->flag & REF_DIR) { 361/* 362 * Do not use get_ref_dir() here, as that might 363 * trigger the reading of loose refs. 364 */ 365clear_ref_dir(&entry->u.subdir); 366} 367free(entry); 368} 369 370/* 371 * Add a ref_entry to the end of dir (unsorted). Entry is always 372 * stored directly in dir; no recursion into subdirectories is 373 * done. 374 */ 375static voidadd_entry_to_dir(struct ref_dir *dir,struct ref_entry *entry) 376{ 377ALLOC_GROW(dir->entries, dir->nr +1, dir->alloc); 378 dir->entries[dir->nr++] = entry; 379/* optimize for the case that entries are added in order */ 380if(dir->nr ==1|| 381(dir->nr == dir->sorted +1&& 382strcmp(dir->entries[dir->nr -2]->name, 383 dir->entries[dir->nr -1]->name) <0)) 384 dir->sorted = dir->nr; 385} 386 387/* 388 * Clear and free all entries in dir, recursively. 389 */ 390static voidclear_ref_dir(struct ref_dir *dir) 391{ 392int i; 393for(i =0; i < dir->nr; i++) 394free_ref_entry(dir->entries[i]); 395free(dir->entries); 396 dir->sorted = dir->nr = dir->alloc =0; 397 dir->entries = NULL; 398} 399 400/* 401 * Create a struct ref_entry object for the specified dirname. 402 * dirname is the name of the directory with a trailing slash (e.g., 403 * "refs/heads/") or "" for the top-level directory. 404 */ 405static struct ref_entry *create_dir_entry(struct ref_cache *ref_cache, 406const char*dirname,size_t len, 407int incomplete) 408{ 409struct ref_entry *direntry; 410 direntry =xcalloc(1,sizeof(struct ref_entry) + len +1); 411memcpy(direntry->name, dirname, len); 412 direntry->name[len] ='\0'; 413 direntry->u.subdir.ref_cache = ref_cache; 414 direntry->flag = REF_DIR | (incomplete ? REF_INCOMPLETE :0); 415return direntry; 416} 417 418static intref_entry_cmp(const void*a,const void*b) 419{ 420struct ref_entry *one = *(struct ref_entry **)a; 421struct ref_entry *two = *(struct ref_entry **)b; 422returnstrcmp(one->name, two->name); 423} 424 425static voidsort_ref_dir(struct ref_dir *dir); 426 427struct string_slice { 428size_t len; 429const char*str; 430}; 431 432static intref_entry_cmp_sslice(const void*key_,const void*ent_) 433{ 434const struct string_slice *key = key_; 435const struct ref_entry *ent = *(const struct ref_entry *const*)ent_; 436int cmp =strncmp(key->str, ent->name, key->len); 437if(cmp) 438return cmp; 439return'\0'- (unsigned char)ent->name[key->len]; 440} 441 442/* 443 * Return the index of the entry with the given refname from the 444 * ref_dir (non-recursively), sorting dir if necessary. Return -1 if 445 * no such entry is found. dir must already be complete. 446 */ 447static intsearch_ref_dir(struct ref_dir *dir,const char*refname,size_t len) 448{ 449struct ref_entry **r; 450struct string_slice key; 451 452if(refname == NULL || !dir->nr) 453return-1; 454 455sort_ref_dir(dir); 456 key.len = len; 457 key.str = refname; 458 r =bsearch(&key, dir->entries, dir->nr,sizeof(*dir->entries), 459 ref_entry_cmp_sslice); 460 461if(r == NULL) 462return-1; 463 464return r - dir->entries; 465} 466 467/* 468 * Search for a directory entry directly within dir (without 469 * recursing). Sort dir if necessary. subdirname must be a directory 470 * name (i.e., end in '/'). If mkdir is set, then create the 471 * directory if it is missing; otherwise, return NULL if the desired 472 * directory cannot be found. dir must already be complete. 473 */ 474static struct ref_dir *search_for_subdir(struct ref_dir *dir, 475const char*subdirname,size_t len, 476int mkdir) 477{ 478int entry_index =search_ref_dir(dir, subdirname, len); 479struct ref_entry *entry; 480if(entry_index == -1) { 481if(!mkdir) 482return NULL; 483/* 484 * Since dir is complete, the absence of a subdir 485 * means that the subdir really doesn't exist; 486 * therefore, create an empty record for it but mark 487 * the record complete. 488 */ 489 entry =create_dir_entry(dir->ref_cache, subdirname, len,0); 490add_entry_to_dir(dir, entry); 491}else{ 492 entry = dir->entries[entry_index]; 493} 494returnget_ref_dir(entry); 495} 496 497/* 498 * If refname is a reference name, find the ref_dir within the dir 499 * tree that should hold refname. If refname is a directory name 500 * (i.e., ends in '/'), then return that ref_dir itself. dir must 501 * represent the top-level directory and must already be complete. 502 * Sort ref_dirs and recurse into subdirectories as necessary. If 503 * mkdir is set, then create any missing directories; otherwise, 504 * return NULL if the desired directory cannot be found. 505 */ 506static struct ref_dir *find_containing_dir(struct ref_dir *dir, 507const char*refname,int mkdir) 508{ 509const char*slash; 510for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 511size_t dirnamelen = slash - refname +1; 512struct ref_dir *subdir; 513 subdir =search_for_subdir(dir, refname, dirnamelen, mkdir); 514if(!subdir) { 515 dir = NULL; 516break; 517} 518 dir = subdir; 519} 520 521return dir; 522} 523 524/* 525 * Find the value entry with the given name in dir, sorting ref_dirs 526 * and recursing into subdirectories as necessary. If the name is not 527 * found or it corresponds to a directory entry, return NULL. 528 */ 529static struct ref_entry *find_ref(struct ref_dir *dir,const char*refname) 530{ 531int entry_index; 532struct ref_entry *entry; 533 dir =find_containing_dir(dir, refname,0); 534if(!dir) 535return NULL; 536 entry_index =search_ref_dir(dir, refname,strlen(refname)); 537if(entry_index == -1) 538return NULL; 539 entry = dir->entries[entry_index]; 540return(entry->flag & REF_DIR) ? NULL : entry; 541} 542 543/* 544 * Remove the entry with the given name from dir, recursing into 545 * subdirectories as necessary. If refname is the name of a directory 546 * (i.e., ends with '/'), then remove the directory and its contents. 547 * If the removal was successful, return the number of entries 548 * remaining in the directory entry that contained the deleted entry. 549 * If the name was not found, return -1. Please note that this 550 * function only deletes the entry from the cache; it does not delete 551 * it from the filesystem or ensure that other cache entries (which 552 * might be symbolic references to the removed entry) are updated. 553 * Nor does it remove any containing dir entries that might be made 554 * empty by the removal. dir must represent the top-level directory 555 * and must already be complete. 556 */ 557static intremove_entry(struct ref_dir *dir,const char*refname) 558{ 559int refname_len =strlen(refname); 560int entry_index; 561struct ref_entry *entry; 562int is_dir = refname[refname_len -1] =='/'; 563if(is_dir) { 564/* 565 * refname represents a reference directory. Remove 566 * the trailing slash; otherwise we will get the 567 * directory *representing* refname rather than the 568 * one *containing* it. 569 */ 570char*dirname =xmemdupz(refname, refname_len -1); 571 dir =find_containing_dir(dir, dirname,0); 572free(dirname); 573}else{ 574 dir =find_containing_dir(dir, refname,0); 575} 576if(!dir) 577return-1; 578 entry_index =search_ref_dir(dir, refname, refname_len); 579if(entry_index == -1) 580return-1; 581 entry = dir->entries[entry_index]; 582 583memmove(&dir->entries[entry_index], 584&dir->entries[entry_index +1], 585(dir->nr - entry_index -1) *sizeof(*dir->entries) 586); 587 dir->nr--; 588if(dir->sorted > entry_index) 589 dir->sorted--; 590free_ref_entry(entry); 591return dir->nr; 592} 593 594/* 595 * Add a ref_entry to the ref_dir (unsorted), recursing into 596 * subdirectories as necessary. dir must represent the top-level 597 * directory. Return 0 on success. 598 */ 599static intadd_ref(struct ref_dir *dir,struct ref_entry *ref) 600{ 601 dir =find_containing_dir(dir, ref->name,1); 602if(!dir) 603return-1; 604add_entry_to_dir(dir, ref); 605return0; 606} 607 608/* 609 * Emit a warning and return true iff ref1 and ref2 have the same name 610 * and the same sha1. Die if they have the same name but different 611 * sha1s. 612 */ 613static intis_dup_ref(const struct ref_entry *ref1,const struct ref_entry *ref2) 614{ 615if(strcmp(ref1->name, ref2->name)) 616return0; 617 618/* Duplicate name; make sure that they don't conflict: */ 619 620if((ref1->flag & REF_DIR) || (ref2->flag & REF_DIR)) 621/* This is impossible by construction */ 622die("Reference directory conflict:%s", ref1->name); 623 624if(hashcmp(ref1->u.value.sha1, ref2->u.value.sha1)) 625die("Duplicated ref, and SHA1s don't match:%s", ref1->name); 626 627warning("Duplicated ref:%s", ref1->name); 628return1; 629} 630 631/* 632 * Sort the entries in dir non-recursively (if they are not already 633 * sorted) and remove any duplicate entries. 634 */ 635static voidsort_ref_dir(struct ref_dir *dir) 636{ 637int i, j; 638struct ref_entry *last = NULL; 639 640/* 641 * This check also prevents passing a zero-length array to qsort(), 642 * which is a problem on some platforms. 643 */ 644if(dir->sorted == dir->nr) 645return; 646 647qsort(dir->entries, dir->nr,sizeof(*dir->entries), ref_entry_cmp); 648 649/* Remove any duplicates: */ 650for(i =0, j =0; j < dir->nr; j++) { 651struct ref_entry *entry = dir->entries[j]; 652if(last &&is_dup_ref(last, entry)) 653free_ref_entry(entry); 654else 655 last = dir->entries[i++] = entry; 656} 657 dir->sorted = dir->nr = i; 658} 659 660/* Include broken references in a do_for_each_ref*() iteration: */ 661#define DO_FOR_EACH_INCLUDE_BROKEN 0x01 662 663/* 664 * Return true iff the reference described by entry can be resolved to 665 * an object in the database. Emit a warning if the referred-to 666 * object does not exist. 667 */ 668static intref_resolves_to_object(struct ref_entry *entry) 669{ 670if(entry->flag & REF_ISBROKEN) 671return0; 672if(!has_sha1_file(entry->u.value.sha1)) { 673error("%sdoes not point to a valid object!", entry->name); 674return0; 675} 676return1; 677} 678 679/* 680 * current_ref is a performance hack: when iterating over references 681 * using the for_each_ref*() functions, current_ref is set to the 682 * current reference's entry before calling the callback function. If 683 * the callback function calls peel_ref(), then peel_ref() first 684 * checks whether the reference to be peeled is the current reference 685 * (it usually is) and if so, returns that reference's peeled version 686 * if it is available. This avoids a refname lookup in a common case. 687 */ 688static struct ref_entry *current_ref; 689 690typedefinteach_ref_entry_fn(struct ref_entry *entry,void*cb_data); 691 692struct ref_entry_cb { 693const char*base; 694int trim; 695int flags; 696 each_ref_fn *fn; 697void*cb_data; 698}; 699 700/* 701 * Handle one reference in a do_for_each_ref*()-style iteration, 702 * calling an each_ref_fn for each entry. 703 */ 704static intdo_one_ref(struct ref_entry *entry,void*cb_data) 705{ 706struct ref_entry_cb *data = cb_data; 707struct ref_entry *old_current_ref; 708int retval; 709 710if(!starts_with(entry->name, data->base)) 711return0; 712 713if(!(data->flags & DO_FOR_EACH_INCLUDE_BROKEN) && 714!ref_resolves_to_object(entry)) 715return0; 716 717/* Store the old value, in case this is a recursive call: */ 718 old_current_ref = current_ref; 719 current_ref = entry; 720 retval = data->fn(entry->name + data->trim, entry->u.value.sha1, 721 entry->flag, data->cb_data); 722 current_ref = old_current_ref; 723return retval; 724} 725 726/* 727 * Call fn for each reference in dir that has index in the range 728 * offset <= index < dir->nr. Recurse into subdirectories that are in 729 * that index range, sorting them before iterating. This function 730 * does not sort dir itself; it should be sorted beforehand. fn is 731 * called for all references, including broken ones. 732 */ 733static intdo_for_each_entry_in_dir(struct ref_dir *dir,int offset, 734 each_ref_entry_fn fn,void*cb_data) 735{ 736int i; 737assert(dir->sorted == dir->nr); 738for(i = offset; i < dir->nr; i++) { 739struct ref_entry *entry = dir->entries[i]; 740int retval; 741if(entry->flag & REF_DIR) { 742struct ref_dir *subdir =get_ref_dir(entry); 743sort_ref_dir(subdir); 744 retval =do_for_each_entry_in_dir(subdir,0, fn, cb_data); 745}else{ 746 retval =fn(entry, cb_data); 747} 748if(retval) 749return retval; 750} 751return0; 752} 753 754/* 755 * Call fn for each reference in the union of dir1 and dir2, in order 756 * by refname. Recurse into subdirectories. If a value entry appears 757 * in both dir1 and dir2, then only process the version that is in 758 * dir2. The input dirs must already be sorted, but subdirs will be 759 * sorted as needed. fn is called for all references, including 760 * broken ones. 761 */ 762static intdo_for_each_entry_in_dirs(struct ref_dir *dir1, 763struct ref_dir *dir2, 764 each_ref_entry_fn fn,void*cb_data) 765{ 766int retval; 767int i1 =0, i2 =0; 768 769assert(dir1->sorted == dir1->nr); 770assert(dir2->sorted == dir2->nr); 771while(1) { 772struct ref_entry *e1, *e2; 773int cmp; 774if(i1 == dir1->nr) { 775returndo_for_each_entry_in_dir(dir2, i2, fn, cb_data); 776} 777if(i2 == dir2->nr) { 778returndo_for_each_entry_in_dir(dir1, i1, fn, cb_data); 779} 780 e1 = dir1->entries[i1]; 781 e2 = dir2->entries[i2]; 782 cmp =strcmp(e1->name, e2->name); 783if(cmp ==0) { 784if((e1->flag & REF_DIR) && (e2->flag & REF_DIR)) { 785/* Both are directories; descend them in parallel. */ 786struct ref_dir *subdir1 =get_ref_dir(e1); 787struct ref_dir *subdir2 =get_ref_dir(e2); 788sort_ref_dir(subdir1); 789sort_ref_dir(subdir2); 790 retval =do_for_each_entry_in_dirs( 791 subdir1, subdir2, fn, cb_data); 792 i1++; 793 i2++; 794}else if(!(e1->flag & REF_DIR) && !(e2->flag & REF_DIR)) { 795/* Both are references; ignore the one from dir1. */ 796 retval =fn(e2, cb_data); 797 i1++; 798 i2++; 799}else{ 800die("conflict between reference and directory:%s", 801 e1->name); 802} 803}else{ 804struct ref_entry *e; 805if(cmp <0) { 806 e = e1; 807 i1++; 808}else{ 809 e = e2; 810 i2++; 811} 812if(e->flag & REF_DIR) { 813struct ref_dir *subdir =get_ref_dir(e); 814sort_ref_dir(subdir); 815 retval =do_for_each_entry_in_dir( 816 subdir,0, fn, cb_data); 817}else{ 818 retval =fn(e, cb_data); 819} 820} 821if(retval) 822return retval; 823} 824} 825 826/* 827 * Load all of the refs from the dir into our in-memory cache. The hard work 828 * of loading loose refs is done by get_ref_dir(), so we just need to recurse 829 * through all of the sub-directories. We do not even need to care about 830 * sorting, as traversal order does not matter to us. 831 */ 832static voidprime_ref_dir(struct ref_dir *dir) 833{ 834int i; 835for(i =0; i < dir->nr; i++) { 836struct ref_entry *entry = dir->entries[i]; 837if(entry->flag & REF_DIR) 838prime_ref_dir(get_ref_dir(entry)); 839} 840} 841 842static intentry_matches(struct ref_entry *entry,const struct string_list *list) 843{ 844return list &&string_list_has_string(list, entry->name); 845} 846 847struct nonmatching_ref_data { 848const struct string_list *skip; 849struct ref_entry *found; 850}; 851 852static intnonmatching_ref_fn(struct ref_entry *entry,void*vdata) 853{ 854struct nonmatching_ref_data *data = vdata; 855 856if(entry_matches(entry, data->skip)) 857return0; 858 859 data->found = entry; 860return1; 861} 862 863static voidreport_refname_conflict(struct ref_entry *entry, 864const char*refname) 865{ 866error("'%s' exists; cannot create '%s'", entry->name, refname); 867} 868 869/* 870 * Return true iff a reference named refname could be created without 871 * conflicting with the name of an existing reference in dir. If 872 * skip is non-NULL, ignore potential conflicts with refs in skip 873 * (e.g., because they are scheduled for deletion in the same 874 * operation). 875 * 876 * Two reference names conflict if one of them exactly matches the 877 * leading components of the other; e.g., "foo/bar" conflicts with 878 * both "foo" and with "foo/bar/baz" but not with "foo/bar" or 879 * "foo/barbados". 880 * 881 * skip must be sorted. 882 */ 883static intis_refname_available(const char*refname, 884const struct string_list *skip, 885struct ref_dir *dir) 886{ 887const char*slash; 888size_t len; 889int pos; 890char*dirname; 891 892for(slash =strchr(refname,'/'); slash; slash =strchr(slash +1,'/')) { 893/* 894 * We are still at a leading dir of the refname; we are 895 * looking for a conflict with a leaf entry. 896 * 897 * If we find one, we still must make sure it is 898 * not in "skip". 899 */ 900 pos =search_ref_dir(dir, refname, slash - refname); 901if(pos >=0) { 902struct ref_entry *entry = dir->entries[pos]; 903if(entry_matches(entry, skip)) 904return1; 905report_refname_conflict(entry, refname); 906return0; 907} 908 909 910/* 911 * Otherwise, we can try to continue our search with 912 * the next component; if we come up empty, we know 913 * there is nothing under this whole prefix. 914 */ 915 pos =search_ref_dir(dir, refname, slash +1- refname); 916if(pos <0) 917return1; 918 919 dir =get_ref_dir(dir->entries[pos]); 920} 921 922/* 923 * We are at the leaf of our refname; we want to 924 * make sure there are no directories which match it. 925 */ 926 len =strlen(refname); 927 dirname =xmallocz(len +1); 928sprintf(dirname,"%s/", refname); 929 pos =search_ref_dir(dir, dirname, len +1); 930free(dirname); 931 932if(pos >=0) { 933/* 934 * We found a directory named "refname". It is a 935 * problem iff it contains any ref that is not 936 * in "skip". 937 */ 938struct ref_entry *entry = dir->entries[pos]; 939struct ref_dir *dir =get_ref_dir(entry); 940struct nonmatching_ref_data data; 941 942 data.skip = skip; 943sort_ref_dir(dir); 944if(!do_for_each_entry_in_dir(dir,0, nonmatching_ref_fn, &data)) 945return1; 946 947report_refname_conflict(data.found, refname); 948return0; 949} 950 951/* 952 * There is no point in searching for another leaf 953 * node which matches it; such an entry would be the 954 * ref we are looking for, not a conflict. 955 */ 956return1; 957} 958 959struct packed_ref_cache { 960struct ref_entry *root; 961 962/* 963 * Count of references to the data structure in this instance, 964 * including the pointer from ref_cache::packed if any. The 965 * data will not be freed as long as the reference count is 966 * nonzero. 967 */ 968unsigned int referrers; 969 970/* 971 * Iff the packed-refs file associated with this instance is 972 * currently locked for writing, this points at the associated 973 * lock (which is owned by somebody else). The referrer count 974 * is also incremented when the file is locked and decremented 975 * when it is unlocked. 976 */ 977struct lock_file *lock; 978 979/* The metadata from when this packed-refs cache was read */ 980struct stat_validity validity; 981}; 982 983/* 984 * Future: need to be in "struct repository" 985 * when doing a full libification. 986 */ 987static struct ref_cache { 988struct ref_cache *next; 989struct ref_entry *loose; 990struct packed_ref_cache *packed; 991/* 992 * The submodule name, or "" for the main repo. We allocate 993 * length 1 rather than FLEX_ARRAY so that the main ref_cache 994 * is initialized correctly. 995 */ 996char name[1]; 997} ref_cache, *submodule_ref_caches; 998 999/* Lock used for the main packed-refs file: */1000static struct lock_file packlock;10011002/*1003 * Increment the reference count of *packed_refs.1004 */1005static voidacquire_packed_ref_cache(struct packed_ref_cache *packed_refs)1006{1007 packed_refs->referrers++;1008}10091010/*1011 * Decrease the reference count of *packed_refs. If it goes to zero,1012 * free *packed_refs and return true; otherwise return false.1013 */1014static intrelease_packed_ref_cache(struct packed_ref_cache *packed_refs)1015{1016if(!--packed_refs->referrers) {1017free_ref_entry(packed_refs->root);1018stat_validity_clear(&packed_refs->validity);1019free(packed_refs);1020return1;1021}else{1022return0;1023}1024}10251026static voidclear_packed_ref_cache(struct ref_cache *refs)1027{1028if(refs->packed) {1029struct packed_ref_cache *packed_refs = refs->packed;10301031if(packed_refs->lock)1032die("internal error: packed-ref cache cleared while locked");1033 refs->packed = NULL;1034release_packed_ref_cache(packed_refs);1035}1036}10371038static voidclear_loose_ref_cache(struct ref_cache *refs)1039{1040if(refs->loose) {1041free_ref_entry(refs->loose);1042 refs->loose = NULL;1043}1044}10451046static struct ref_cache *create_ref_cache(const char*submodule)1047{1048int len;1049struct ref_cache *refs;1050if(!submodule)1051 submodule ="";1052 len =strlen(submodule) +1;1053 refs =xcalloc(1,sizeof(struct ref_cache) + len);1054memcpy(refs->name, submodule, len);1055return refs;1056}10571058/*1059 * Return a pointer to a ref_cache for the specified submodule. For1060 * the main repository, use submodule==NULL. The returned structure1061 * will be allocated and initialized but not necessarily populated; it1062 * should not be freed.1063 */1064static struct ref_cache *get_ref_cache(const char*submodule)1065{1066struct ref_cache *refs;10671068if(!submodule || !*submodule)1069return&ref_cache;10701071for(refs = submodule_ref_caches; refs; refs = refs->next)1072if(!strcmp(submodule, refs->name))1073return refs;10741075 refs =create_ref_cache(submodule);1076 refs->next = submodule_ref_caches;1077 submodule_ref_caches = refs;1078return refs;1079}10801081/* The length of a peeled reference line in packed-refs, including EOL: */1082#define PEELED_LINE_LENGTH 4210831084/*1085 * The packed-refs header line that we write out. Perhaps other1086 * traits will be added later. The trailing space is required.1087 */1088static const char PACKED_REFS_HEADER[] =1089"# pack-refs with: peeled fully-peeled\n";10901091/*1092 * Parse one line from a packed-refs file. Write the SHA1 to sha1.1093 * Return a pointer to the refname within the line (null-terminated),1094 * or NULL if there was a problem.1095 */1096static const char*parse_ref_line(struct strbuf *line,unsigned char*sha1)1097{1098const char*ref;10991100/*1101 * 42: the answer to everything.1102 *1103 * In this case, it happens to be the answer to1104 * 40 (length of sha1 hex representation)1105 * +1 (space in between hex and name)1106 * +1 (newline at the end of the line)1107 */1108if(line->len <=42)1109return NULL;11101111if(get_sha1_hex(line->buf, sha1) <0)1112return NULL;1113if(!isspace(line->buf[40]))1114return NULL;11151116 ref = line->buf +41;1117if(isspace(*ref))1118return NULL;11191120if(line->buf[line->len -1] !='\n')1121return NULL;1122 line->buf[--line->len] =0;11231124return ref;1125}11261127/*1128 * Read f, which is a packed-refs file, into dir.1129 *1130 * A comment line of the form "# pack-refs with: " may contain zero or1131 * more traits. We interpret the traits as follows:1132 *1133 * No traits:1134 *1135 * Probably no references are peeled. But if the file contains a1136 * peeled value for a reference, we will use it.1137 *1138 * peeled:1139 *1140 * References under "refs/tags/", if they *can* be peeled, *are*1141 * peeled in this file. References outside of "refs/tags/" are1142 * probably not peeled even if they could have been, but if we find1143 * a peeled value for such a reference we will use it.1144 *1145 * fully-peeled:1146 *1147 * All references in the file that can be peeled are peeled.1148 * Inversely (and this is more important), any references in the1149 * file for which no peeled value is recorded is not peelable. This1150 * trait should typically be written alongside "peeled" for1151 * compatibility with older clients, but we do not require it1152 * (i.e., "peeled" is a no-op if "fully-peeled" is set).1153 */1154static voidread_packed_refs(FILE*f,struct ref_dir *dir)1155{1156struct ref_entry *last = NULL;1157struct strbuf line = STRBUF_INIT;1158enum{ PEELED_NONE, PEELED_TAGS, PEELED_FULLY } peeled = PEELED_NONE;11591160while(strbuf_getwholeline(&line, f,'\n') != EOF) {1161unsigned char sha1[20];1162const char*refname;1163const char*traits;11641165if(skip_prefix(line.buf,"# pack-refs with:", &traits)) {1166if(strstr(traits," fully-peeled "))1167 peeled = PEELED_FULLY;1168else if(strstr(traits," peeled "))1169 peeled = PEELED_TAGS;1170/* perhaps other traits later as well */1171continue;1172}11731174 refname =parse_ref_line(&line, sha1);1175if(refname) {1176int flag = REF_ISPACKED;11771178if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1179if(!refname_is_safe(refname))1180die("packed refname is dangerous:%s", refname);1181hashclr(sha1);1182 flag |= REF_BAD_NAME | REF_ISBROKEN;1183}1184 last =create_ref_entry(refname, sha1, flag,0);1185if(peeled == PEELED_FULLY ||1186(peeled == PEELED_TAGS &&starts_with(refname,"refs/tags/")))1187 last->flag |= REF_KNOWS_PEELED;1188add_ref(dir, last);1189continue;1190}1191if(last &&1192 line.buf[0] =='^'&&1193 line.len == PEELED_LINE_LENGTH &&1194 line.buf[PEELED_LINE_LENGTH -1] =='\n'&&1195!get_sha1_hex(line.buf +1, sha1)) {1196hashcpy(last->u.value.peeled, sha1);1197/*1198 * Regardless of what the file header said,1199 * we definitely know the value of *this*1200 * reference:1201 */1202 last->flag |= REF_KNOWS_PEELED;1203}1204}12051206strbuf_release(&line);1207}12081209/*1210 * Get the packed_ref_cache for the specified ref_cache, creating it1211 * if necessary.1212 */1213static struct packed_ref_cache *get_packed_ref_cache(struct ref_cache *refs)1214{1215const char*packed_refs_file;12161217if(*refs->name)1218 packed_refs_file =git_path_submodule(refs->name,"packed-refs");1219else1220 packed_refs_file =git_path("packed-refs");12211222if(refs->packed &&1223!stat_validity_check(&refs->packed->validity, packed_refs_file))1224clear_packed_ref_cache(refs);12251226if(!refs->packed) {1227FILE*f;12281229 refs->packed =xcalloc(1,sizeof(*refs->packed));1230acquire_packed_ref_cache(refs->packed);1231 refs->packed->root =create_dir_entry(refs,"",0,0);1232 f =fopen(packed_refs_file,"r");1233if(f) {1234stat_validity_update(&refs->packed->validity,fileno(f));1235read_packed_refs(f,get_ref_dir(refs->packed->root));1236fclose(f);1237}1238}1239return refs->packed;1240}12411242static struct ref_dir *get_packed_ref_dir(struct packed_ref_cache *packed_ref_cache)1243{1244returnget_ref_dir(packed_ref_cache->root);1245}12461247static struct ref_dir *get_packed_refs(struct ref_cache *refs)1248{1249returnget_packed_ref_dir(get_packed_ref_cache(refs));1250}12511252voidadd_packed_ref(const char*refname,const unsigned char*sha1)1253{1254struct packed_ref_cache *packed_ref_cache =1255get_packed_ref_cache(&ref_cache);12561257if(!packed_ref_cache->lock)1258die("internal error: packed refs not locked");1259add_ref(get_packed_ref_dir(packed_ref_cache),1260create_ref_entry(refname, sha1, REF_ISPACKED,1));1261}12621263/*1264 * Read the loose references from the namespace dirname into dir1265 * (without recursing). dirname must end with '/'. dir must be the1266 * directory entry corresponding to dirname.1267 */1268static voidread_loose_refs(const char*dirname,struct ref_dir *dir)1269{1270struct ref_cache *refs = dir->ref_cache;1271DIR*d;1272const char*path;1273struct dirent *de;1274int dirnamelen =strlen(dirname);1275struct strbuf refname;12761277if(*refs->name)1278 path =git_path_submodule(refs->name,"%s", dirname);1279else1280 path =git_path("%s", dirname);12811282 d =opendir(path);1283if(!d)1284return;12851286strbuf_init(&refname, dirnamelen +257);1287strbuf_add(&refname, dirname, dirnamelen);12881289while((de =readdir(d)) != NULL) {1290unsigned char sha1[20];1291struct stat st;1292int flag;1293const char*refdir;12941295if(de->d_name[0] =='.')1296continue;1297if(ends_with(de->d_name,".lock"))1298continue;1299strbuf_addstr(&refname, de->d_name);1300 refdir = *refs->name1301?git_path_submodule(refs->name,"%s", refname.buf)1302:git_path("%s", refname.buf);1303if(stat(refdir, &st) <0) {1304;/* silently ignore */1305}else if(S_ISDIR(st.st_mode)) {1306strbuf_addch(&refname,'/');1307add_entry_to_dir(dir,1308create_dir_entry(refs, refname.buf,1309 refname.len,1));1310}else{1311if(*refs->name) {1312hashclr(sha1);1313 flag =0;1314if(resolve_gitlink_ref(refs->name, refname.buf, sha1) <0) {1315hashclr(sha1);1316 flag |= REF_ISBROKEN;1317}1318}else if(read_ref_full(refname.buf,1319 RESOLVE_REF_READING,1320 sha1, &flag)) {1321hashclr(sha1);1322 flag |= REF_ISBROKEN;1323}1324if(check_refname_format(refname.buf,1325 REFNAME_ALLOW_ONELEVEL)) {1326if(!refname_is_safe(refname.buf))1327die("loose refname is dangerous:%s", refname.buf);1328hashclr(sha1);1329 flag |= REF_BAD_NAME | REF_ISBROKEN;1330}1331add_entry_to_dir(dir,1332create_ref_entry(refname.buf, sha1, flag,0));1333}1334strbuf_setlen(&refname, dirnamelen);1335}1336strbuf_release(&refname);1337closedir(d);1338}13391340static struct ref_dir *get_loose_refs(struct ref_cache *refs)1341{1342if(!refs->loose) {1343/*1344 * Mark the top-level directory complete because we1345 * are about to read the only subdirectory that can1346 * hold references:1347 */1348 refs->loose =create_dir_entry(refs,"",0,0);1349/*1350 * Create an incomplete entry for "refs/":1351 */1352add_entry_to_dir(get_ref_dir(refs->loose),1353create_dir_entry(refs,"refs/",5,1));1354}1355returnget_ref_dir(refs->loose);1356}13571358/* We allow "recursive" symbolic refs. Only within reason, though */1359#define MAXDEPTH 51360#define MAXREFLEN (1024)13611362/*1363 * Called by resolve_gitlink_ref_recursive() after it failed to read1364 * from the loose refs in ref_cache refs. Find <refname> in the1365 * packed-refs file for the submodule.1366 */1367static intresolve_gitlink_packed_ref(struct ref_cache *refs,1368const char*refname,unsigned char*sha1)1369{1370struct ref_entry *ref;1371struct ref_dir *dir =get_packed_refs(refs);13721373 ref =find_ref(dir, refname);1374if(ref == NULL)1375return-1;13761377hashcpy(sha1, ref->u.value.sha1);1378return0;1379}13801381static intresolve_gitlink_ref_recursive(struct ref_cache *refs,1382const char*refname,unsigned char*sha1,1383int recursion)1384{1385int fd, len;1386char buffer[128], *p;1387const char*path;13881389if(recursion > MAXDEPTH ||strlen(refname) > MAXREFLEN)1390return-1;1391 path = *refs->name1392?git_path_submodule(refs->name,"%s", refname)1393:git_path("%s", refname);1394 fd =open(path, O_RDONLY);1395if(fd <0)1396returnresolve_gitlink_packed_ref(refs, refname, sha1);13971398 len =read(fd, buffer,sizeof(buffer)-1);1399close(fd);1400if(len <0)1401return-1;1402while(len &&isspace(buffer[len-1]))1403 len--;1404 buffer[len] =0;14051406/* Was it a detached head or an old-fashioned symlink? */1407if(!get_sha1_hex(buffer, sha1))1408return0;14091410/* Symref? */1411if(strncmp(buffer,"ref:",4))1412return-1;1413 p = buffer +4;1414while(isspace(*p))1415 p++;14161417returnresolve_gitlink_ref_recursive(refs, p, sha1, recursion+1);1418}14191420intresolve_gitlink_ref(const char*path,const char*refname,unsigned char*sha1)1421{1422int len =strlen(path), retval;1423char*submodule;1424struct ref_cache *refs;14251426while(len && path[len-1] =='/')1427 len--;1428if(!len)1429return-1;1430 submodule =xstrndup(path, len);1431 refs =get_ref_cache(submodule);1432free(submodule);14331434 retval =resolve_gitlink_ref_recursive(refs, refname, sha1,0);1435return retval;1436}14371438/*1439 * Return the ref_entry for the given refname from the packed1440 * references. If it does not exist, return NULL.1441 */1442static struct ref_entry *get_packed_ref(const char*refname)1443{1444returnfind_ref(get_packed_refs(&ref_cache), refname);1445}14461447/*1448 * A loose ref file doesn't exist; check for a packed ref. The1449 * options are forwarded from resolve_safe_unsafe().1450 */1451static intresolve_missing_loose_ref(const char*refname,1452int resolve_flags,1453unsigned char*sha1,1454int*flags)1455{1456struct ref_entry *entry;14571458/*1459 * The loose reference file does not exist; check for a packed1460 * reference.1461 */1462 entry =get_packed_ref(refname);1463if(entry) {1464hashcpy(sha1, entry->u.value.sha1);1465if(flags)1466*flags |= REF_ISPACKED;1467return0;1468}1469/* The reference is not a packed reference, either. */1470if(resolve_flags & RESOLVE_REF_READING) {1471 errno = ENOENT;1472return-1;1473}else{1474hashclr(sha1);1475return0;1476}1477}14781479/* This function needs to return a meaningful errno on failure */1480static const char*resolve_ref_unsafe_1(const char*refname,1481int resolve_flags,1482unsigned char*sha1,1483int*flags,1484struct strbuf *sb_path)1485{1486int depth = MAXDEPTH;1487 ssize_t len;1488char buffer[256];1489static char refname_buffer[256];1490int bad_name =0;14911492if(flags)1493*flags =0;14941495if(check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {1496if(flags)1497*flags |= REF_BAD_NAME;14981499if(!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1500!refname_is_safe(refname)) {1501 errno = EINVAL;1502return NULL;1503}1504/*1505 * dwim_ref() uses REF_ISBROKEN to distinguish between1506 * missing refs and refs that were present but invalid,1507 * to complain about the latter to stderr.1508 *1509 * We don't know whether the ref exists, so don't set1510 * REF_ISBROKEN yet.1511 */1512 bad_name =1;1513}1514for(;;) {1515const char*path;1516struct stat st;1517char*buf;1518int fd;15191520if(--depth <0) {1521 errno = ELOOP;1522return NULL;1523}15241525strbuf_reset(sb_path);1526strbuf_git_path(sb_path,"%s", refname);1527 path = sb_path->buf;15281529/*1530 * We might have to loop back here to avoid a race1531 * condition: first we lstat() the file, then we try1532 * to read it as a link or as a file. But if somebody1533 * changes the type of the file (file <-> directory1534 * <-> symlink) between the lstat() and reading, then1535 * we don't want to report that as an error but rather1536 * try again starting with the lstat().1537 */1538 stat_ref:1539if(lstat(path, &st) <0) {1540if(errno != ENOENT)1541return NULL;1542if(resolve_missing_loose_ref(refname, resolve_flags,1543 sha1, flags))1544return NULL;1545if(bad_name) {1546hashclr(sha1);1547if(flags)1548*flags |= REF_ISBROKEN;1549}1550return refname;1551}15521553/* Follow "normalized" - ie "refs/.." symlinks by hand */1554if(S_ISLNK(st.st_mode)) {1555 len =readlink(path, buffer,sizeof(buffer)-1);1556if(len <0) {1557if(errno == ENOENT || errno == EINVAL)1558/* inconsistent with lstat; retry */1559goto stat_ref;1560else1561return NULL;1562}1563 buffer[len] =0;1564if(starts_with(buffer,"refs/") &&1565!check_refname_format(buffer,0)) {1566strcpy(refname_buffer, buffer);1567 refname = refname_buffer;1568if(flags)1569*flags |= REF_ISSYMREF;1570if(resolve_flags & RESOLVE_REF_NO_RECURSE) {1571hashclr(sha1);1572return refname;1573}1574continue;1575}1576}15771578/* Is it a directory? */1579if(S_ISDIR(st.st_mode)) {1580 errno = EISDIR;1581return NULL;1582}15831584/*1585 * Anything else, just open it and try to use it as1586 * a ref1587 */1588 fd =open(path, O_RDONLY);1589if(fd <0) {1590if(errno == ENOENT)1591/* inconsistent with lstat; retry */1592goto stat_ref;1593else1594return NULL;1595}1596 len =read_in_full(fd, buffer,sizeof(buffer)-1);1597if(len <0) {1598int save_errno = errno;1599close(fd);1600 errno = save_errno;1601return NULL;1602}1603close(fd);1604while(len &&isspace(buffer[len-1]))1605 len--;1606 buffer[len] ='\0';16071608/*1609 * Is it a symbolic ref?1610 */1611if(!starts_with(buffer,"ref:")) {1612/*1613 * Please note that FETCH_HEAD has a second1614 * line containing other data.1615 */1616if(get_sha1_hex(buffer, sha1) ||1617(buffer[40] !='\0'&& !isspace(buffer[40]))) {1618if(flags)1619*flags |= REF_ISBROKEN;1620 errno = EINVAL;1621return NULL;1622}1623if(bad_name) {1624hashclr(sha1);1625if(flags)1626*flags |= REF_ISBROKEN;1627}1628return refname;1629}1630if(flags)1631*flags |= REF_ISSYMREF;1632 buf = buffer +4;1633while(isspace(*buf))1634 buf++;1635 refname =strcpy(refname_buffer, buf);1636if(resolve_flags & RESOLVE_REF_NO_RECURSE) {1637hashclr(sha1);1638return refname;1639}1640if(check_refname_format(buf, REFNAME_ALLOW_ONELEVEL)) {1641if(flags)1642*flags |= REF_ISBROKEN;16431644if(!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||1645!refname_is_safe(buf)) {1646 errno = EINVAL;1647return NULL;1648}1649 bad_name =1;1650}1651}1652}16531654const char*resolve_ref_unsafe(const char*refname,int resolve_flags,1655unsigned char*sha1,int*flags)1656{1657struct strbuf sb_path = STRBUF_INIT;1658const char*ret =resolve_ref_unsafe_1(refname, resolve_flags,1659 sha1, flags, &sb_path);1660strbuf_release(&sb_path);1661return ret;1662}16631664char*resolve_refdup(const char*ref,int resolve_flags,unsigned char*sha1,int*flags)1665{1666returnxstrdup_or_null(resolve_ref_unsafe(ref, resolve_flags, sha1, flags));1667}16681669/* The argument to filter_refs */1670struct ref_filter {1671const char*pattern;1672 each_ref_fn *fn;1673void*cb_data;1674};16751676intread_ref_full(const char*refname,int resolve_flags,unsigned char*sha1,int*flags)1677{1678if(resolve_ref_unsafe(refname, resolve_flags, sha1, flags))1679return0;1680return-1;1681}16821683intread_ref(const char*refname,unsigned char*sha1)1684{1685returnread_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);1686}16871688intref_exists(const char*refname)1689{1690unsigned char sha1[20];1691return!!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);1692}16931694static intfilter_refs(const char*refname,const unsigned char*sha1,int flags,1695void*data)1696{1697struct ref_filter *filter = (struct ref_filter *)data;1698if(wildmatch(filter->pattern, refname,0, NULL))1699return0;1700return filter->fn(refname, sha1, flags, filter->cb_data);1701}17021703enum peel_status {1704/* object was peeled successfully: */1705 PEEL_PEELED =0,17061707/*1708 * object cannot be peeled because the named object (or an1709 * object referred to by a tag in the peel chain), does not1710 * exist.1711 */1712 PEEL_INVALID = -1,17131714/* object cannot be peeled because it is not a tag: */1715 PEEL_NON_TAG = -2,17161717/* ref_entry contains no peeled value because it is a symref: */1718 PEEL_IS_SYMREF = -3,17191720/*1721 * ref_entry cannot be peeled because it is broken (i.e., the1722 * symbolic reference cannot even be resolved to an object1723 * name):1724 */1725 PEEL_BROKEN = -41726};17271728/*1729 * Peel the named object; i.e., if the object is a tag, resolve the1730 * tag recursively until a non-tag is found. If successful, store the1731 * result to sha1 and return PEEL_PEELED. If the object is not a tag1732 * or is not valid, return PEEL_NON_TAG or PEEL_INVALID, respectively,1733 * and leave sha1 unchanged.1734 */1735static enum peel_status peel_object(const unsigned char*name,unsigned char*sha1)1736{1737struct object *o =lookup_unknown_object(name);17381739if(o->type == OBJ_NONE) {1740int type =sha1_object_info(name, NULL);1741if(type <0|| !object_as_type(o, type,0))1742return PEEL_INVALID;1743}17441745if(o->type != OBJ_TAG)1746return PEEL_NON_TAG;17471748 o =deref_tag_noverify(o);1749if(!o)1750return PEEL_INVALID;17511752hashcpy(sha1, o->sha1);1753return PEEL_PEELED;1754}17551756/*1757 * Peel the entry (if possible) and return its new peel_status. If1758 * repeel is true, re-peel the entry even if there is an old peeled1759 * value that is already stored in it.1760 *1761 * It is OK to call this function with a packed reference entry that1762 * might be stale and might even refer to an object that has since1763 * been garbage-collected. In such a case, if the entry has1764 * REF_KNOWS_PEELED then leave the status unchanged and return1765 * PEEL_PEELED or PEEL_NON_TAG; otherwise, return PEEL_INVALID.1766 */1767static enum peel_status peel_entry(struct ref_entry *entry,int repeel)1768{1769enum peel_status status;17701771if(entry->flag & REF_KNOWS_PEELED) {1772if(repeel) {1773 entry->flag &= ~REF_KNOWS_PEELED;1774hashclr(entry->u.value.peeled);1775}else{1776returnis_null_sha1(entry->u.value.peeled) ?1777 PEEL_NON_TAG : PEEL_PEELED;1778}1779}1780if(entry->flag & REF_ISBROKEN)1781return PEEL_BROKEN;1782if(entry->flag & REF_ISSYMREF)1783return PEEL_IS_SYMREF;17841785 status =peel_object(entry->u.value.sha1, entry->u.value.peeled);1786if(status == PEEL_PEELED || status == PEEL_NON_TAG)1787 entry->flag |= REF_KNOWS_PEELED;1788return status;1789}17901791intpeel_ref(const char*refname,unsigned char*sha1)1792{1793int flag;1794unsigned char base[20];17951796if(current_ref && (current_ref->name == refname1797|| !strcmp(current_ref->name, refname))) {1798if(peel_entry(current_ref,0))1799return-1;1800hashcpy(sha1, current_ref->u.value.peeled);1801return0;1802}18031804if(read_ref_full(refname, RESOLVE_REF_READING, base, &flag))1805return-1;18061807/*1808 * If the reference is packed, read its ref_entry from the1809 * cache in the hope that we already know its peeled value.1810 * We only try this optimization on packed references because1811 * (a) forcing the filling of the loose reference cache could1812 * be expensive and (b) loose references anyway usually do not1813 * have REF_KNOWS_PEELED.1814 */1815if(flag & REF_ISPACKED) {1816struct ref_entry *r =get_packed_ref(refname);1817if(r) {1818if(peel_entry(r,0))1819return-1;1820hashcpy(sha1, r->u.value.peeled);1821return0;1822}1823}18241825returnpeel_object(base, sha1);1826}18271828struct warn_if_dangling_data {1829FILE*fp;1830const char*refname;1831const struct string_list *refnames;1832const char*msg_fmt;1833};18341835static intwarn_if_dangling_symref(const char*refname,const unsigned char*sha1,1836int flags,void*cb_data)1837{1838struct warn_if_dangling_data *d = cb_data;1839const char*resolves_to;1840unsigned char junk[20];18411842if(!(flags & REF_ISSYMREF))1843return0;18441845 resolves_to =resolve_ref_unsafe(refname,0, junk, NULL);1846if(!resolves_to1847|| (d->refname1848?strcmp(resolves_to, d->refname)1849: !string_list_has_string(d->refnames, resolves_to))) {1850return0;1851}18521853fprintf(d->fp, d->msg_fmt, refname);1854fputc('\n', d->fp);1855return0;1856}18571858voidwarn_dangling_symref(FILE*fp,const char*msg_fmt,const char*refname)1859{1860struct warn_if_dangling_data data;18611862 data.fp = fp;1863 data.refname = refname;1864 data.refnames = NULL;1865 data.msg_fmt = msg_fmt;1866for_each_rawref(warn_if_dangling_symref, &data);1867}18681869voidwarn_dangling_symrefs(FILE*fp,const char*msg_fmt,const struct string_list *refnames)1870{1871struct warn_if_dangling_data data;18721873 data.fp = fp;1874 data.refname = NULL;1875 data.refnames = refnames;1876 data.msg_fmt = msg_fmt;1877for_each_rawref(warn_if_dangling_symref, &data);1878}18791880/*1881 * Call fn for each reference in the specified ref_cache, omitting1882 * references not in the containing_dir of base. fn is called for all1883 * references, including broken ones. If fn ever returns a non-zero1884 * value, stop the iteration and return that value; otherwise, return1885 * 0.1886 */1887static intdo_for_each_entry(struct ref_cache *refs,const char*base,1888 each_ref_entry_fn fn,void*cb_data)1889{1890struct packed_ref_cache *packed_ref_cache;1891struct ref_dir *loose_dir;1892struct ref_dir *packed_dir;1893int retval =0;18941895/*1896 * We must make sure that all loose refs are read before accessing the1897 * packed-refs file; this avoids a race condition in which loose refs1898 * are migrated to the packed-refs file by a simultaneous process, but1899 * our in-memory view is from before the migration. get_packed_ref_cache()1900 * takes care of making sure our view is up to date with what is on1901 * disk.1902 */1903 loose_dir =get_loose_refs(refs);1904if(base && *base) {1905 loose_dir =find_containing_dir(loose_dir, base,0);1906}1907if(loose_dir)1908prime_ref_dir(loose_dir);19091910 packed_ref_cache =get_packed_ref_cache(refs);1911acquire_packed_ref_cache(packed_ref_cache);1912 packed_dir =get_packed_ref_dir(packed_ref_cache);1913if(base && *base) {1914 packed_dir =find_containing_dir(packed_dir, base,0);1915}19161917if(packed_dir && loose_dir) {1918sort_ref_dir(packed_dir);1919sort_ref_dir(loose_dir);1920 retval =do_for_each_entry_in_dirs(1921 packed_dir, loose_dir, fn, cb_data);1922}else if(packed_dir) {1923sort_ref_dir(packed_dir);1924 retval =do_for_each_entry_in_dir(1925 packed_dir,0, fn, cb_data);1926}else if(loose_dir) {1927sort_ref_dir(loose_dir);1928 retval =do_for_each_entry_in_dir(1929 loose_dir,0, fn, cb_data);1930}19311932release_packed_ref_cache(packed_ref_cache);1933return retval;1934}19351936/*1937 * Call fn for each reference in the specified ref_cache for which the1938 * refname begins with base. If trim is non-zero, then trim that many1939 * characters off the beginning of each refname before passing the1940 * refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to include1941 * broken references in the iteration. If fn ever returns a non-zero1942 * value, stop the iteration and return that value; otherwise, return1943 * 0.1944 */1945static intdo_for_each_ref(struct ref_cache *refs,const char*base,1946 each_ref_fn fn,int trim,int flags,void*cb_data)1947{1948struct ref_entry_cb data;1949 data.base = base;1950 data.trim = trim;1951 data.flags = flags;1952 data.fn = fn;1953 data.cb_data = cb_data;19541955if(ref_paranoia <0)1956 ref_paranoia =git_env_bool("GIT_REF_PARANOIA",0);1957if(ref_paranoia)1958 data.flags |= DO_FOR_EACH_INCLUDE_BROKEN;19591960returndo_for_each_entry(refs, base, do_one_ref, &data);1961}19621963static intdo_head_ref(const char*submodule, each_ref_fn fn,void*cb_data)1964{1965unsigned char sha1[20];1966int flag;19671968if(submodule) {1969if(resolve_gitlink_ref(submodule,"HEAD", sha1) ==0)1970returnfn("HEAD", sha1,0, cb_data);19711972return0;1973}19741975if(!read_ref_full("HEAD", RESOLVE_REF_READING, sha1, &flag))1976returnfn("HEAD", sha1, flag, cb_data);19771978return0;1979}19801981inthead_ref(each_ref_fn fn,void*cb_data)1982{1983returndo_head_ref(NULL, fn, cb_data);1984}19851986inthead_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1987{1988returndo_head_ref(submodule, fn, cb_data);1989}19901991intfor_each_ref(each_ref_fn fn,void*cb_data)1992{1993returndo_for_each_ref(&ref_cache,"", fn,0,0, cb_data);1994}19951996intfor_each_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)1997{1998returndo_for_each_ref(get_ref_cache(submodule),"", fn,0,0, cb_data);1999}20002001intfor_each_ref_in(const char*prefix, each_ref_fn fn,void*cb_data)2002{2003returndo_for_each_ref(&ref_cache, prefix, fn,strlen(prefix),0, cb_data);2004}20052006intfor_each_ref_in_submodule(const char*submodule,const char*prefix,2007 each_ref_fn fn,void*cb_data)2008{2009returndo_for_each_ref(get_ref_cache(submodule), prefix, fn,strlen(prefix),0, cb_data);2010}20112012intfor_each_tag_ref(each_ref_fn fn,void*cb_data)2013{2014returnfor_each_ref_in("refs/tags/", fn, cb_data);2015}20162017intfor_each_tag_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2018{2019returnfor_each_ref_in_submodule(submodule,"refs/tags/", fn, cb_data);2020}20212022intfor_each_branch_ref(each_ref_fn fn,void*cb_data)2023{2024returnfor_each_ref_in("refs/heads/", fn, cb_data);2025}20262027intfor_each_branch_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2028{2029returnfor_each_ref_in_submodule(submodule,"refs/heads/", fn, cb_data);2030}20312032intfor_each_remote_ref(each_ref_fn fn,void*cb_data)2033{2034returnfor_each_ref_in("refs/remotes/", fn, cb_data);2035}20362037intfor_each_remote_ref_submodule(const char*submodule, each_ref_fn fn,void*cb_data)2038{2039returnfor_each_ref_in_submodule(submodule,"refs/remotes/", fn, cb_data);2040}20412042intfor_each_replace_ref(each_ref_fn fn,void*cb_data)2043{2044returndo_for_each_ref(&ref_cache,"refs/replace/", fn,13,0, cb_data);2045}20462047inthead_ref_namespaced(each_ref_fn fn,void*cb_data)2048{2049struct strbuf buf = STRBUF_INIT;2050int ret =0;2051unsigned char sha1[20];2052int flag;20532054strbuf_addf(&buf,"%sHEAD",get_git_namespace());2055if(!read_ref_full(buf.buf, RESOLVE_REF_READING, sha1, &flag))2056 ret =fn(buf.buf, sha1, flag, cb_data);2057strbuf_release(&buf);20582059return ret;2060}20612062intfor_each_namespaced_ref(each_ref_fn fn,void*cb_data)2063{2064struct strbuf buf = STRBUF_INIT;2065int ret;2066strbuf_addf(&buf,"%srefs/",get_git_namespace());2067 ret =do_for_each_ref(&ref_cache, buf.buf, fn,0,0, cb_data);2068strbuf_release(&buf);2069return ret;2070}20712072intfor_each_glob_ref_in(each_ref_fn fn,const char*pattern,2073const char*prefix,void*cb_data)2074{2075struct strbuf real_pattern = STRBUF_INIT;2076struct ref_filter filter;2077int ret;20782079if(!prefix && !starts_with(pattern,"refs/"))2080strbuf_addstr(&real_pattern,"refs/");2081else if(prefix)2082strbuf_addstr(&real_pattern, prefix);2083strbuf_addstr(&real_pattern, pattern);20842085if(!has_glob_specials(pattern)) {2086/* Append implied '/' '*' if not present. */2087if(real_pattern.buf[real_pattern.len -1] !='/')2088strbuf_addch(&real_pattern,'/');2089/* No need to check for '*', there is none. */2090strbuf_addch(&real_pattern,'*');2091}20922093 filter.pattern = real_pattern.buf;2094 filter.fn = fn;2095 filter.cb_data = cb_data;2096 ret =for_each_ref(filter_refs, &filter);20972098strbuf_release(&real_pattern);2099return ret;2100}21012102intfor_each_glob_ref(each_ref_fn fn,const char*pattern,void*cb_data)2103{2104returnfor_each_glob_ref_in(fn, pattern, NULL, cb_data);2105}21062107intfor_each_rawref(each_ref_fn fn,void*cb_data)2108{2109returndo_for_each_ref(&ref_cache,"", fn,0,2110 DO_FOR_EACH_INCLUDE_BROKEN, cb_data);2111}21122113const char*prettify_refname(const char*name)2114{2115return name + (2116starts_with(name,"refs/heads/") ?11:2117starts_with(name,"refs/tags/") ?10:2118starts_with(name,"refs/remotes/") ?13:21190);2120}21212122static const char*ref_rev_parse_rules[] = {2123"%.*s",2124"refs/%.*s",2125"refs/tags/%.*s",2126"refs/heads/%.*s",2127"refs/remotes/%.*s",2128"refs/remotes/%.*s/HEAD",2129 NULL2130};21312132intrefname_match(const char*abbrev_name,const char*full_name)2133{2134const char**p;2135const int abbrev_name_len =strlen(abbrev_name);21362137for(p = ref_rev_parse_rules; *p; p++) {2138if(!strcmp(full_name,mkpath(*p, abbrev_name_len, abbrev_name))) {2139return1;2140}2141}21422143return0;2144}21452146static voidunlock_ref(struct ref_lock *lock)2147{2148/* Do not free lock->lk -- atexit() still looks at them */2149if(lock->lk)2150rollback_lock_file(lock->lk);2151free(lock->ref_name);2152free(lock->orig_ref_name);2153free(lock);2154}21552156/* This function should make sure errno is meaningful on error */2157static struct ref_lock *verify_lock(struct ref_lock *lock,2158const unsigned char*old_sha1,int mustexist)2159{2160if(read_ref_full(lock->ref_name,2161 mustexist ? RESOLVE_REF_READING :0,2162 lock->old_sha1, NULL)) {2163int save_errno = errno;2164error("Can't verify ref%s", lock->ref_name);2165unlock_ref(lock);2166 errno = save_errno;2167return NULL;2168}2169if(hashcmp(lock->old_sha1, old_sha1)) {2170error("Ref%sis at%sbut expected%s", lock->ref_name,2171sha1_to_hex(lock->old_sha1),sha1_to_hex(old_sha1));2172unlock_ref(lock);2173 errno = EBUSY;2174return NULL;2175}2176return lock;2177}21782179static intremove_empty_directories(const char*file)2180{2181/* we want to create a file but there is a directory there;2182 * if that is an empty directory (or a directory that contains2183 * only empty directories), remove them.2184 */2185struct strbuf path;2186int result, save_errno;21872188strbuf_init(&path,20);2189strbuf_addstr(&path, file);21902191 result =remove_dir_recursively(&path, REMOVE_DIR_EMPTY_ONLY);2192 save_errno = errno;21932194strbuf_release(&path);2195 errno = save_errno;21962197return result;2198}21992200/*2201 * *string and *len will only be substituted, and *string returned (for2202 * later free()ing) if the string passed in is a magic short-hand form2203 * to name a branch.2204 */2205static char*substitute_branch_name(const char**string,int*len)2206{2207struct strbuf buf = STRBUF_INIT;2208int ret =interpret_branch_name(*string, *len, &buf);22092210if(ret == *len) {2211size_t size;2212*string =strbuf_detach(&buf, &size);2213*len = size;2214return(char*)*string;2215}22162217return NULL;2218}22192220intdwim_ref(const char*str,int len,unsigned char*sha1,char**ref)2221{2222char*last_branch =substitute_branch_name(&str, &len);2223const char**p, *r;2224int refs_found =0;22252226*ref = NULL;2227for(p = ref_rev_parse_rules; *p; p++) {2228char fullref[PATH_MAX];2229unsigned char sha1_from_ref[20];2230unsigned char*this_result;2231int flag;22322233 this_result = refs_found ? sha1_from_ref : sha1;2234mksnpath(fullref,sizeof(fullref), *p, len, str);2235 r =resolve_ref_unsafe(fullref, RESOLVE_REF_READING,2236 this_result, &flag);2237if(r) {2238if(!refs_found++)2239*ref =xstrdup(r);2240if(!warn_ambiguous_refs)2241break;2242}else if((flag & REF_ISSYMREF) &&strcmp(fullref,"HEAD")) {2243warning("ignoring dangling symref%s.", fullref);2244}else if((flag & REF_ISBROKEN) &&strchr(fullref,'/')) {2245warning("ignoring broken ref%s.", fullref);2246}2247}2248free(last_branch);2249return refs_found;2250}22512252intdwim_log(const char*str,int len,unsigned char*sha1,char**log)2253{2254char*last_branch =substitute_branch_name(&str, &len);2255const char**p;2256int logs_found =0;22572258*log = NULL;2259for(p = ref_rev_parse_rules; *p; p++) {2260unsigned char hash[20];2261char path[PATH_MAX];2262const char*ref, *it;22632264mksnpath(path,sizeof(path), *p, len, str);2265 ref =resolve_ref_unsafe(path, RESOLVE_REF_READING,2266 hash, NULL);2267if(!ref)2268continue;2269if(reflog_exists(path))2270 it = path;2271else if(strcmp(ref, path) &&reflog_exists(ref))2272 it = ref;2273else2274continue;2275if(!logs_found++) {2276*log =xstrdup(it);2277hashcpy(sha1, hash);2278}2279if(!warn_ambiguous_refs)2280break;2281}2282free(last_branch);2283return logs_found;2284}22852286/*2287 * Locks a ref returning the lock on success and NULL on failure.2288 * On failure errno is set to something meaningful.2289 */2290static struct ref_lock *lock_ref_sha1_basic(const char*refname,2291const unsigned char*old_sha1,2292const struct string_list *skip,2293unsigned int flags,int*type_p)2294{2295const char*ref_file;2296const char*orig_refname = refname;2297struct ref_lock *lock;2298int last_errno =0;2299int type, lflags;2300int mustexist = (old_sha1 && !is_null_sha1(old_sha1));2301int resolve_flags =0;2302int attempts_remaining =3;23032304 lock =xcalloc(1,sizeof(struct ref_lock));2305 lock->lock_fd = -1;23062307if(mustexist)2308 resolve_flags |= RESOLVE_REF_READING;2309if(flags & REF_DELETING) {2310 resolve_flags |= RESOLVE_REF_ALLOW_BAD_NAME;2311if(flags & REF_NODEREF)2312 resolve_flags |= RESOLVE_REF_NO_RECURSE;2313}23142315 refname =resolve_ref_unsafe(refname, resolve_flags,2316 lock->old_sha1, &type);2317if(!refname && errno == EISDIR) {2318/* we are trying to lock foo but we used to2319 * have foo/bar which now does not exist;2320 * it is normal for the empty directory 'foo'2321 * to remain.2322 */2323 ref_file =git_path("%s", orig_refname);2324if(remove_empty_directories(ref_file)) {2325 last_errno = errno;2326error("there are still refs under '%s'", orig_refname);2327goto error_return;2328}2329 refname =resolve_ref_unsafe(orig_refname, resolve_flags,2330 lock->old_sha1, &type);2331}2332if(type_p)2333*type_p = type;2334if(!refname) {2335 last_errno = errno;2336error("unable to resolve reference%s:%s",2337 orig_refname,strerror(errno));2338goto error_return;2339}2340/*2341 * If the ref did not exist and we are creating it, make sure2342 * there is no existing packed ref whose name begins with our2343 * refname, nor a packed ref whose name is a proper prefix of2344 * our refname.2345 */2346if(is_null_sha1(lock->old_sha1) &&2347!is_refname_available(refname, skip,get_packed_refs(&ref_cache))) {2348 last_errno = ENOTDIR;2349goto error_return;2350}23512352 lock->lk =xcalloc(1,sizeof(struct lock_file));23532354 lflags =0;2355if(flags & REF_NODEREF) {2356 refname = orig_refname;2357 lflags |= LOCK_NO_DEREF;2358}2359 lock->ref_name =xstrdup(refname);2360 lock->orig_ref_name =xstrdup(orig_refname);2361 ref_file =git_path("%s", refname);23622363 retry:2364switch(safe_create_leading_directories_const(ref_file)) {2365case SCLD_OK:2366break;/* success */2367case SCLD_VANISHED:2368if(--attempts_remaining >0)2369goto retry;2370/* fall through */2371default:2372 last_errno = errno;2373error("unable to create directory for%s", ref_file);2374goto error_return;2375}23762377 lock->lock_fd =hold_lock_file_for_update(lock->lk, ref_file, lflags);2378if(lock->lock_fd <0) {2379 last_errno = errno;2380if(errno == ENOENT && --attempts_remaining >0)2381/*2382 * Maybe somebody just deleted one of the2383 * directories leading to ref_file. Try2384 * again:2385 */2386goto retry;2387else{2388struct strbuf err = STRBUF_INIT;2389unable_to_lock_message(ref_file, errno, &err);2390error("%s", err.buf);2391strbuf_release(&err);2392goto error_return;2393}2394}2395return old_sha1 ?verify_lock(lock, old_sha1, mustexist) : lock;23962397 error_return:2398unlock_ref(lock);2399 errno = last_errno;2400return NULL;2401}24022403/*2404 * Write an entry to the packed-refs file for the specified refname.2405 * If peeled is non-NULL, write it as the entry's peeled value.2406 */2407static voidwrite_packed_entry(FILE*fh,char*refname,unsigned char*sha1,2408unsigned char*peeled)2409{2410fprintf_or_die(fh,"%s %s\n",sha1_to_hex(sha1), refname);2411if(peeled)2412fprintf_or_die(fh,"^%s\n",sha1_to_hex(peeled));2413}24142415/*2416 * An each_ref_entry_fn that writes the entry to a packed-refs file.2417 */2418static intwrite_packed_entry_fn(struct ref_entry *entry,void*cb_data)2419{2420enum peel_status peel_status =peel_entry(entry,0);24212422if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2423error("internal error:%sis not a valid packed reference!",2424 entry->name);2425write_packed_entry(cb_data, entry->name, entry->u.value.sha1,2426 peel_status == PEEL_PEELED ?2427 entry->u.value.peeled : NULL);2428return0;2429}24302431/* This should return a meaningful errno on failure */2432intlock_packed_refs(int flags)2433{2434struct packed_ref_cache *packed_ref_cache;24352436if(hold_lock_file_for_update(&packlock,git_path("packed-refs"), flags) <0)2437return-1;2438/*2439 * Get the current packed-refs while holding the lock. If the2440 * packed-refs file has been modified since we last read it,2441 * this will automatically invalidate the cache and re-read2442 * the packed-refs file.2443 */2444 packed_ref_cache =get_packed_ref_cache(&ref_cache);2445 packed_ref_cache->lock = &packlock;2446/* Increment the reference count to prevent it from being freed: */2447acquire_packed_ref_cache(packed_ref_cache);2448return0;2449}24502451/*2452 * Commit the packed refs changes.2453 * On error we must make sure that errno contains a meaningful value.2454 */2455intcommit_packed_refs(void)2456{2457struct packed_ref_cache *packed_ref_cache =2458get_packed_ref_cache(&ref_cache);2459int error =0;2460int save_errno =0;2461FILE*out;24622463if(!packed_ref_cache->lock)2464die("internal error: packed-refs not locked");24652466 out =fdopen_lock_file(packed_ref_cache->lock,"w");2467if(!out)2468die_errno("unable to fdopen packed-refs descriptor");24692470fprintf_or_die(out,"%s", PACKED_REFS_HEADER);2471do_for_each_entry_in_dir(get_packed_ref_dir(packed_ref_cache),24720, write_packed_entry_fn, out);24732474if(commit_lock_file(packed_ref_cache->lock)) {2475 save_errno = errno;2476 error = -1;2477}2478 packed_ref_cache->lock = NULL;2479release_packed_ref_cache(packed_ref_cache);2480 errno = save_errno;2481return error;2482}24832484voidrollback_packed_refs(void)2485{2486struct packed_ref_cache *packed_ref_cache =2487get_packed_ref_cache(&ref_cache);24882489if(!packed_ref_cache->lock)2490die("internal error: packed-refs not locked");2491rollback_lock_file(packed_ref_cache->lock);2492 packed_ref_cache->lock = NULL;2493release_packed_ref_cache(packed_ref_cache);2494clear_packed_ref_cache(&ref_cache);2495}24962497struct ref_to_prune {2498struct ref_to_prune *next;2499unsigned char sha1[20];2500char name[FLEX_ARRAY];2501};25022503struct pack_refs_cb_data {2504unsigned int flags;2505struct ref_dir *packed_refs;2506struct ref_to_prune *ref_to_prune;2507};25082509/*2510 * An each_ref_entry_fn that is run over loose references only. If2511 * the loose reference can be packed, add an entry in the packed ref2512 * cache. If the reference should be pruned, also add it to2513 * ref_to_prune in the pack_refs_cb_data.2514 */2515static intpack_if_possible_fn(struct ref_entry *entry,void*cb_data)2516{2517struct pack_refs_cb_data *cb = cb_data;2518enum peel_status peel_status;2519struct ref_entry *packed_entry;2520int is_tag_ref =starts_with(entry->name,"refs/tags/");25212522/* ALWAYS pack tags */2523if(!(cb->flags & PACK_REFS_ALL) && !is_tag_ref)2524return0;25252526/* Do not pack symbolic or broken refs: */2527if((entry->flag & REF_ISSYMREF) || !ref_resolves_to_object(entry))2528return0;25292530/* Add a packed ref cache entry equivalent to the loose entry. */2531 peel_status =peel_entry(entry,1);2532if(peel_status != PEEL_PEELED && peel_status != PEEL_NON_TAG)2533die("internal error peeling reference%s(%s)",2534 entry->name,sha1_to_hex(entry->u.value.sha1));2535 packed_entry =find_ref(cb->packed_refs, entry->name);2536if(packed_entry) {2537/* Overwrite existing packed entry with info from loose entry */2538 packed_entry->flag = REF_ISPACKED | REF_KNOWS_PEELED;2539hashcpy(packed_entry->u.value.sha1, entry->u.value.sha1);2540}else{2541 packed_entry =create_ref_entry(entry->name, entry->u.value.sha1,2542 REF_ISPACKED | REF_KNOWS_PEELED,0);2543add_ref(cb->packed_refs, packed_entry);2544}2545hashcpy(packed_entry->u.value.peeled, entry->u.value.peeled);25462547/* Schedule the loose reference for pruning if requested. */2548if((cb->flags & PACK_REFS_PRUNE)) {2549int namelen =strlen(entry->name) +1;2550struct ref_to_prune *n =xcalloc(1,sizeof(*n) + namelen);2551hashcpy(n->sha1, entry->u.value.sha1);2552strcpy(n->name, entry->name);2553 n->next = cb->ref_to_prune;2554 cb->ref_to_prune = n;2555}2556return0;2557}25582559/*2560 * Remove empty parents, but spare refs/ and immediate subdirs.2561 * Note: munges *name.2562 */2563static voidtry_remove_empty_parents(char*name)2564{2565char*p, *q;2566int i;2567 p = name;2568for(i =0; i <2; i++) {/* refs/{heads,tags,...}/ */2569while(*p && *p !='/')2570 p++;2571/* tolerate duplicate slashes; see check_refname_format() */2572while(*p =='/')2573 p++;2574}2575for(q = p; *q; q++)2576;2577while(1) {2578while(q > p && *q !='/')2579 q--;2580while(q > p && *(q-1) =='/')2581 q--;2582if(q == p)2583break;2584*q ='\0';2585if(rmdir(git_path("%s", name)))2586break;2587}2588}25892590/* make sure nobody touched the ref, and unlink */2591static voidprune_ref(struct ref_to_prune *r)2592{2593struct ref_transaction *transaction;2594struct strbuf err = STRBUF_INIT;25952596if(check_refname_format(r->name,0))2597return;25982599 transaction =ref_transaction_begin(&err);2600if(!transaction ||2601ref_transaction_delete(transaction, r->name, r->sha1,2602 REF_ISPRUNING, NULL, &err) ||2603ref_transaction_commit(transaction, &err)) {2604ref_transaction_free(transaction);2605error("%s", err.buf);2606strbuf_release(&err);2607return;2608}2609ref_transaction_free(transaction);2610strbuf_release(&err);2611try_remove_empty_parents(r->name);2612}26132614static voidprune_refs(struct ref_to_prune *r)2615{2616while(r) {2617prune_ref(r);2618 r = r->next;2619}2620}26212622intpack_refs(unsigned int flags)2623{2624struct pack_refs_cb_data cbdata;26252626memset(&cbdata,0,sizeof(cbdata));2627 cbdata.flags = flags;26282629lock_packed_refs(LOCK_DIE_ON_ERROR);2630 cbdata.packed_refs =get_packed_refs(&ref_cache);26312632do_for_each_entry_in_dir(get_loose_refs(&ref_cache),0,2633 pack_if_possible_fn, &cbdata);26342635if(commit_packed_refs())2636die_errno("unable to overwrite old ref-pack file");26372638prune_refs(cbdata.ref_to_prune);2639return0;2640}26412642intrepack_without_refs(struct string_list *refnames,struct strbuf *err)2643{2644struct ref_dir *packed;2645struct string_list_item *refname;2646int ret, needs_repacking =0, removed =0;26472648assert(err);26492650/* Look for a packed ref */2651for_each_string_list_item(refname, refnames) {2652if(get_packed_ref(refname->string)) {2653 needs_repacking =1;2654break;2655}2656}26572658/* Avoid locking if we have nothing to do */2659if(!needs_repacking)2660return0;/* no refname exists in packed refs */26612662if(lock_packed_refs(0)) {2663unable_to_lock_message(git_path("packed-refs"), errno, err);2664return-1;2665}2666 packed =get_packed_refs(&ref_cache);26672668/* Remove refnames from the cache */2669for_each_string_list_item(refname, refnames)2670if(remove_entry(packed, refname->string) != -1)2671 removed =1;2672if(!removed) {2673/*2674 * All packed entries disappeared while we were2675 * acquiring the lock.2676 */2677rollback_packed_refs();2678return0;2679}26802681/* Write what remains */2682 ret =commit_packed_refs();2683if(ret)2684strbuf_addf(err,"unable to overwrite old ref-pack file:%s",2685strerror(errno));2686return ret;2687}26882689static intdelete_ref_loose(struct ref_lock *lock,int flag,struct strbuf *err)2690{2691assert(err);26922693if(!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {2694/*2695 * loose. The loose file name is the same as the2696 * lockfile name, minus ".lock":2697 */2698char*loose_filename =get_locked_file_path(lock->lk);2699int res =unlink_or_msg(loose_filename, err);2700free(loose_filename);2701if(res)2702return1;2703}2704return0;2705}27062707intdelete_ref(const char*refname,const unsigned char*sha1,unsigned int flags)2708{2709struct ref_transaction *transaction;2710struct strbuf err = STRBUF_INIT;27112712 transaction =ref_transaction_begin(&err);2713if(!transaction ||2714ref_transaction_delete(transaction, refname,2715(sha1 && !is_null_sha1(sha1)) ? sha1 : NULL,2716 flags, NULL, &err) ||2717ref_transaction_commit(transaction, &err)) {2718error("%s", err.buf);2719ref_transaction_free(transaction);2720strbuf_release(&err);2721return1;2722}2723ref_transaction_free(transaction);2724strbuf_release(&err);2725return0;2726}27272728/*2729 * People using contrib's git-new-workdir have .git/logs/refs ->2730 * /some/other/path/.git/logs/refs, and that may live on another device.2731 *2732 * IOW, to avoid cross device rename errors, the temporary renamed log must2733 * live into logs/refs.2734 */2735#define TMP_RENAMED_LOG"logs/refs/.tmp-renamed-log"27362737static intrename_tmp_log(const char*newrefname)2738{2739int attempts_remaining =4;27402741 retry:2742switch(safe_create_leading_directories_const(git_path("logs/%s", newrefname))) {2743case SCLD_OK:2744break;/* success */2745case SCLD_VANISHED:2746if(--attempts_remaining >0)2747goto retry;2748/* fall through */2749default:2750error("unable to create directory for%s", newrefname);2751return-1;2752}27532754if(rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", newrefname))) {2755if((errno==EISDIR || errno==ENOTDIR) && --attempts_remaining >0) {2756/*2757 * rename(a, b) when b is an existing2758 * directory ought to result in ISDIR, but2759 * Solaris 5.8 gives ENOTDIR. Sheesh.2760 */2761if(remove_empty_directories(git_path("logs/%s", newrefname))) {2762error("Directory not empty: logs/%s", newrefname);2763return-1;2764}2765goto retry;2766}else if(errno == ENOENT && --attempts_remaining >0) {2767/*2768 * Maybe another process just deleted one of2769 * the directories in the path to newrefname.2770 * Try again from the beginning.2771 */2772goto retry;2773}else{2774error("unable to move logfile "TMP_RENAMED_LOG" to logs/%s:%s",2775 newrefname,strerror(errno));2776return-1;2777}2778}2779return0;2780}27812782static intrename_ref_available(const char*oldname,const char*newname)2783{2784struct string_list skip = STRING_LIST_INIT_NODUP;2785int ret;27862787string_list_insert(&skip, oldname);2788 ret =is_refname_available(newname, &skip,get_packed_refs(&ref_cache))2789&&is_refname_available(newname, &skip,get_loose_refs(&ref_cache));2790string_list_clear(&skip,0);2791return ret;2792}27932794static intwrite_ref_sha1(struct ref_lock *lock,const unsigned char*sha1,2795const char*logmsg);27962797intrename_ref(const char*oldrefname,const char*newrefname,const char*logmsg)2798{2799unsigned char sha1[20], orig_sha1[20];2800int flag =0, logmoved =0;2801struct ref_lock *lock;2802struct stat loginfo;2803int log = !lstat(git_path("logs/%s", oldrefname), &loginfo);2804const char*symref = NULL;28052806if(log &&S_ISLNK(loginfo.st_mode))2807returnerror("reflog for%sis a symlink", oldrefname);28082809 symref =resolve_ref_unsafe(oldrefname, RESOLVE_REF_READING,2810 orig_sha1, &flag);2811if(flag & REF_ISSYMREF)2812returnerror("refname%sis a symbolic ref, renaming it is not supported",2813 oldrefname);2814if(!symref)2815returnerror("refname%snot found", oldrefname);28162817if(!rename_ref_available(oldrefname, newrefname))2818return1;28192820if(log &&rename(git_path("logs/%s", oldrefname),git_path(TMP_RENAMED_LOG)))2821returnerror("unable to move logfile logs/%sto "TMP_RENAMED_LOG":%s",2822 oldrefname,strerror(errno));28232824if(delete_ref(oldrefname, orig_sha1, REF_NODEREF)) {2825error("unable to delete old%s", oldrefname);2826goto rollback;2827}28282829if(!read_ref_full(newrefname, RESOLVE_REF_READING, sha1, NULL) &&2830delete_ref(newrefname, sha1, REF_NODEREF)) {2831if(errno==EISDIR) {2832if(remove_empty_directories(git_path("%s", newrefname))) {2833error("Directory not empty:%s", newrefname);2834goto rollback;2835}2836}else{2837error("unable to delete existing%s", newrefname);2838goto rollback;2839}2840}28412842if(log &&rename_tmp_log(newrefname))2843goto rollback;28442845 logmoved = log;28462847 lock =lock_ref_sha1_basic(newrefname, NULL, NULL,0, NULL);2848if(!lock) {2849error("unable to lock%sfor update", newrefname);2850goto rollback;2851}2852hashcpy(lock->old_sha1, orig_sha1);2853if(write_ref_sha1(lock, orig_sha1, logmsg)) {2854error("unable to write current sha1 into%s", newrefname);2855goto rollback;2856}28572858return0;28592860 rollback:2861 lock =lock_ref_sha1_basic(oldrefname, NULL, NULL,0, NULL);2862if(!lock) {2863error("unable to lock%sfor rollback", oldrefname);2864goto rollbacklog;2865}28662867 flag = log_all_ref_updates;2868 log_all_ref_updates =0;2869if(write_ref_sha1(lock, orig_sha1, NULL))2870error("unable to write current sha1 into%s", oldrefname);2871 log_all_ref_updates = flag;28722873 rollbacklog:2874if(logmoved &&rename(git_path("logs/%s", newrefname),git_path("logs/%s", oldrefname)))2875error("unable to restore logfile%sfrom%s:%s",2876 oldrefname, newrefname,strerror(errno));2877if(!logmoved && log &&2878rename(git_path(TMP_RENAMED_LOG),git_path("logs/%s", oldrefname)))2879error("unable to restore logfile%sfrom "TMP_RENAMED_LOG":%s",2880 oldrefname,strerror(errno));28812882return1;2883}28842885static intclose_ref(struct ref_lock *lock)2886{2887if(close_lock_file(lock->lk))2888return-1;2889 lock->lock_fd = -1;2890return0;2891}28922893static intcommit_ref(struct ref_lock *lock)2894{2895if(commit_lock_file(lock->lk))2896return-1;2897 lock->lock_fd = -1;2898return0;2899}29002901/*2902 * copy the reflog message msg to buf, which has been allocated sufficiently2903 * large, while cleaning up the whitespaces. Especially, convert LF to space,2904 * because reflog file is one line per entry.2905 */2906static intcopy_msg(char*buf,const char*msg)2907{2908char*cp = buf;2909char c;2910int wasspace =1;29112912*cp++ ='\t';2913while((c = *msg++)) {2914if(wasspace &&isspace(c))2915continue;2916 wasspace =isspace(c);2917if(wasspace)2918 c =' ';2919*cp++ = c;2920}2921while(buf < cp &&isspace(cp[-1]))2922 cp--;2923*cp++ ='\n';2924return cp - buf;2925}29262927/* This function must set a meaningful errno on failure */2928intlog_ref_setup(const char*refname,struct strbuf *sb_logfile)2929{2930int logfd, oflags = O_APPEND | O_WRONLY;2931char*logfile;29322933strbuf_git_path(sb_logfile,"logs/%s", refname);2934 logfile = sb_logfile->buf;2935/* make sure the rest of the function can't change "logfile" */2936 sb_logfile = NULL;2937if(log_all_ref_updates &&2938(starts_with(refname,"refs/heads/") ||2939starts_with(refname,"refs/remotes/") ||2940starts_with(refname,"refs/notes/") ||2941!strcmp(refname,"HEAD"))) {2942if(safe_create_leading_directories(logfile) <0) {2943int save_errno = errno;2944error("unable to create directory for%s", logfile);2945 errno = save_errno;2946return-1;2947}2948 oflags |= O_CREAT;2949}29502951 logfd =open(logfile, oflags,0666);2952if(logfd <0) {2953if(!(oflags & O_CREAT) && (errno == ENOENT || errno == EISDIR))2954return0;29552956if(errno == EISDIR) {2957if(remove_empty_directories(logfile)) {2958int save_errno = errno;2959error("There are still logs under '%s'",2960 logfile);2961 errno = save_errno;2962return-1;2963}2964 logfd =open(logfile, oflags,0666);2965}29662967if(logfd <0) {2968int save_errno = errno;2969error("Unable to append to%s:%s", logfile,2970strerror(errno));2971 errno = save_errno;2972return-1;2973}2974}29752976adjust_shared_perm(logfile);2977close(logfd);2978return0;2979}29802981static intlog_ref_write_fd(int fd,const unsigned char*old_sha1,2982const unsigned char*new_sha1,2983const char*committer,const char*msg)2984{2985int msglen, written;2986unsigned maxlen, len;2987char*logrec;29882989 msglen = msg ?strlen(msg) :0;2990 maxlen =strlen(committer) + msglen +100;2991 logrec =xmalloc(maxlen);2992 len =sprintf(logrec,"%s %s %s\n",2993sha1_to_hex(old_sha1),2994sha1_to_hex(new_sha1),2995 committer);2996if(msglen)2997 len +=copy_msg(logrec + len -1, msg) -1;29982999 written = len <= maxlen ?write_in_full(fd, logrec, len) : -1;3000free(logrec);3001if(written != len)3002return-1;30033004return0;3005}30063007static intlog_ref_write_1(const char*refname,const unsigned char*old_sha1,3008const unsigned char*new_sha1,const char*msg,3009struct strbuf *sb_log_file)3010{3011int logfd, result, oflags = O_APPEND | O_WRONLY;3012char*log_file;30133014if(log_all_ref_updates <0)3015 log_all_ref_updates = !is_bare_repository();30163017 result =log_ref_setup(refname, sb_log_file);3018if(result)3019return result;3020 log_file = sb_log_file->buf;3021/* make sure the rest of the function can't change "log_file" */3022 sb_log_file = NULL;30233024 logfd =open(log_file, oflags);3025if(logfd <0)3026return0;3027 result =log_ref_write_fd(logfd, old_sha1, new_sha1,3028git_committer_info(0), msg);3029if(result) {3030int save_errno = errno;3031close(logfd);3032error("Unable to append to%s", log_file);3033 errno = save_errno;3034return-1;3035}3036if(close(logfd)) {3037int save_errno = errno;3038error("Unable to append to%s", log_file);3039 errno = save_errno;3040return-1;3041}3042return0;3043}30443045static intlog_ref_write(const char*refname,const unsigned char*old_sha1,3046const unsigned char*new_sha1,const char*msg)3047{3048struct strbuf sb = STRBUF_INIT;3049int ret =log_ref_write_1(refname, old_sha1, new_sha1, msg, &sb);3050strbuf_release(&sb);3051return ret;3052}30533054intis_branch(const char*refname)3055{3056return!strcmp(refname,"HEAD") ||starts_with(refname,"refs/heads/");3057}30583059/*3060 * Write sha1 into the ref specified by the lock. Make sure that errno3061 * is sane on error.3062 */3063static intwrite_ref_sha1(struct ref_lock *lock,3064const unsigned char*sha1,const char*logmsg)3065{3066static char term ='\n';3067struct object *o;30683069 o =parse_object(sha1);3070if(!o) {3071error("Trying to write ref%swith nonexistent object%s",3072 lock->ref_name,sha1_to_hex(sha1));3073unlock_ref(lock);3074 errno = EINVAL;3075return-1;3076}3077if(o->type != OBJ_COMMIT &&is_branch(lock->ref_name)) {3078error("Trying to write non-commit object%sto branch%s",3079sha1_to_hex(sha1), lock->ref_name);3080unlock_ref(lock);3081 errno = EINVAL;3082return-1;3083}3084if(write_in_full(lock->lock_fd,sha1_to_hex(sha1),40) !=40||3085write_in_full(lock->lock_fd, &term,1) !=1||3086close_ref(lock) <0) {3087int save_errno = errno;3088error("Couldn't write%s", lock->lk->filename.buf);3089unlock_ref(lock);3090 errno = save_errno;3091return-1;3092}3093clear_loose_ref_cache(&ref_cache);3094if(log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) <0||3095(strcmp(lock->ref_name, lock->orig_ref_name) &&3096log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) <0)) {3097unlock_ref(lock);3098return-1;3099}3100if(strcmp(lock->orig_ref_name,"HEAD") !=0) {3101/*3102 * Special hack: If a branch is updated directly and HEAD3103 * points to it (may happen on the remote side of a push3104 * for example) then logically the HEAD reflog should be3105 * updated too.3106 * A generic solution implies reverse symref information,3107 * but finding all symrefs pointing to the given branch3108 * would be rather costly for this rare event (the direct3109 * update of a branch) to be worth it. So let's cheat and3110 * check with HEAD only which should cover 99% of all usage3111 * scenarios (even 100% of the default ones).3112 */3113unsigned char head_sha1[20];3114int head_flag;3115const char*head_ref;3116 head_ref =resolve_ref_unsafe("HEAD", RESOLVE_REF_READING,3117 head_sha1, &head_flag);3118if(head_ref && (head_flag & REF_ISSYMREF) &&3119!strcmp(head_ref, lock->ref_name))3120log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);3121}3122if(commit_ref(lock)) {3123error("Couldn't set%s", lock->ref_name);3124unlock_ref(lock);3125return-1;3126}3127unlock_ref(lock);3128return0;3129}31303131intcreate_symref(const char*ref_target,const char*refs_heads_master,3132const char*logmsg)3133{3134const char*lockpath;3135char ref[1000];3136int fd, len, written;3137char*git_HEAD =git_pathdup("%s", ref_target);3138unsigned char old_sha1[20], new_sha1[20];31393140if(logmsg &&read_ref(ref_target, old_sha1))3141hashclr(old_sha1);31423143if(safe_create_leading_directories(git_HEAD) <0)3144returnerror("unable to create directory for%s", git_HEAD);31453146#ifndef NO_SYMLINK_HEAD3147if(prefer_symlink_refs) {3148unlink(git_HEAD);3149if(!symlink(refs_heads_master, git_HEAD))3150goto done;3151fprintf(stderr,"no symlink - falling back to symbolic ref\n");3152}3153#endif31543155 len =snprintf(ref,sizeof(ref),"ref:%s\n", refs_heads_master);3156if(sizeof(ref) <= len) {3157error("refname too long:%s", refs_heads_master);3158goto error_free_return;3159}3160 lockpath =mkpath("%s.lock", git_HEAD);3161 fd =open(lockpath, O_CREAT | O_EXCL | O_WRONLY,0666);3162if(fd <0) {3163error("Unable to open%sfor writing", lockpath);3164goto error_free_return;3165}3166 written =write_in_full(fd, ref, len);3167if(close(fd) !=0|| written != len) {3168error("Unable to write to%s", lockpath);3169goto error_unlink_return;3170}3171if(rename(lockpath, git_HEAD) <0) {3172error("Unable to create%s", git_HEAD);3173goto error_unlink_return;3174}3175if(adjust_shared_perm(git_HEAD)) {3176error("Unable to fix permissions on%s", lockpath);3177 error_unlink_return:3178unlink_or_warn(lockpath);3179 error_free_return:3180free(git_HEAD);3181return-1;3182}31833184#ifndef NO_SYMLINK_HEAD3185 done:3186#endif3187if(logmsg && !read_ref(refs_heads_master, new_sha1))3188log_ref_write(ref_target, old_sha1, new_sha1, logmsg);31893190free(git_HEAD);3191return0;3192}31933194struct read_ref_at_cb {3195const char*refname;3196unsigned long at_time;3197int cnt;3198int reccnt;3199unsigned char*sha1;3200int found_it;32013202unsigned char osha1[20];3203unsigned char nsha1[20];3204int tz;3205unsigned long date;3206char**msg;3207unsigned long*cutoff_time;3208int*cutoff_tz;3209int*cutoff_cnt;3210};32113212static intread_ref_at_ent(unsigned char*osha1,unsigned char*nsha1,3213const char*email,unsigned long timestamp,int tz,3214const char*message,void*cb_data)3215{3216struct read_ref_at_cb *cb = cb_data;32173218 cb->reccnt++;3219 cb->tz = tz;3220 cb->date = timestamp;32213222if(timestamp <= cb->at_time || cb->cnt ==0) {3223if(cb->msg)3224*cb->msg =xstrdup(message);3225if(cb->cutoff_time)3226*cb->cutoff_time = timestamp;3227if(cb->cutoff_tz)3228*cb->cutoff_tz = tz;3229if(cb->cutoff_cnt)3230*cb->cutoff_cnt = cb->reccnt -1;3231/*3232 * we have not yet updated cb->[n|o]sha1 so they still3233 * hold the values for the previous record.3234 */3235if(!is_null_sha1(cb->osha1)) {3236hashcpy(cb->sha1, nsha1);3237if(hashcmp(cb->osha1, nsha1))3238warning("Log for ref%shas gap after%s.",3239 cb->refname,show_date(cb->date, cb->tz, DATE_RFC2822));3240}3241else if(cb->date == cb->at_time)3242hashcpy(cb->sha1, nsha1);3243else if(hashcmp(nsha1, cb->sha1))3244warning("Log for ref%sunexpectedly ended on%s.",3245 cb->refname,show_date(cb->date, cb->tz,3246 DATE_RFC2822));3247hashcpy(cb->osha1, osha1);3248hashcpy(cb->nsha1, nsha1);3249 cb->found_it =1;3250return1;3251}3252hashcpy(cb->osha1, osha1);3253hashcpy(cb->nsha1, nsha1);3254if(cb->cnt >0)3255 cb->cnt--;3256return0;3257}32583259static intread_ref_at_ent_oldest(unsigned char*osha1,unsigned char*nsha1,3260const char*email,unsigned long timestamp,3261int tz,const char*message,void*cb_data)3262{3263struct read_ref_at_cb *cb = cb_data;32643265if(cb->msg)3266*cb->msg =xstrdup(message);3267if(cb->cutoff_time)3268*cb->cutoff_time = timestamp;3269if(cb->cutoff_tz)3270*cb->cutoff_tz = tz;3271if(cb->cutoff_cnt)3272*cb->cutoff_cnt = cb->reccnt;3273hashcpy(cb->sha1, osha1);3274if(is_null_sha1(cb->sha1))3275hashcpy(cb->sha1, nsha1);3276/* We just want the first entry */3277return1;3278}32793280intread_ref_at(const char*refname,unsigned int flags,unsigned long at_time,int cnt,3281unsigned char*sha1,char**msg,3282unsigned long*cutoff_time,int*cutoff_tz,int*cutoff_cnt)3283{3284struct read_ref_at_cb cb;32853286memset(&cb,0,sizeof(cb));3287 cb.refname = refname;3288 cb.at_time = at_time;3289 cb.cnt = cnt;3290 cb.msg = msg;3291 cb.cutoff_time = cutoff_time;3292 cb.cutoff_tz = cutoff_tz;3293 cb.cutoff_cnt = cutoff_cnt;3294 cb.sha1 = sha1;32953296for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);32973298if(!cb.reccnt) {3299if(flags & GET_SHA1_QUIETLY)3300exit(128);3301else3302die("Log for%sis empty.", refname);3303}3304if(cb.found_it)3305return0;33063307for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);33083309return1;3310}33113312intreflog_exists(const char*refname)3313{3314struct stat st;33153316return!lstat(git_path("logs/%s", refname), &st) &&3317S_ISREG(st.st_mode);3318}33193320intdelete_reflog(const char*refname)3321{3322returnremove_path(git_path("logs/%s", refname));3323}33243325static intshow_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn,void*cb_data)3326{3327unsigned char osha1[20], nsha1[20];3328char*email_end, *message;3329unsigned long timestamp;3330int tz;33313332/* old SP new SP name <email> SP time TAB msg LF */3333if(sb->len <83|| sb->buf[sb->len -1] !='\n'||3334get_sha1_hex(sb->buf, osha1) || sb->buf[40] !=' '||3335get_sha1_hex(sb->buf +41, nsha1) || sb->buf[81] !=' '||3336!(email_end =strchr(sb->buf +82,'>')) ||3337 email_end[1] !=' '||3338!(timestamp =strtoul(email_end +2, &message,10)) ||3339!message || message[0] !=' '||3340(message[1] !='+'&& message[1] !='-') ||3341!isdigit(message[2]) || !isdigit(message[3]) ||3342!isdigit(message[4]) || !isdigit(message[5]))3343return0;/* corrupt? */3344 email_end[1] ='\0';3345 tz =strtol(message +1, NULL,10);3346if(message[6] !='\t')3347 message +=6;3348else3349 message +=7;3350returnfn(osha1, nsha1, sb->buf +82, timestamp, tz, message, cb_data);3351}33523353static char*find_beginning_of_line(char*bob,char*scan)3354{3355while(bob < scan && *(--scan) !='\n')3356;/* keep scanning backwards */3357/*3358 * Return either beginning of the buffer, or LF at the end of3359 * the previous line.3360 */3361return scan;3362}33633364intfor_each_reflog_ent_reverse(const char*refname, each_reflog_ent_fn fn,void*cb_data)3365{3366struct strbuf sb = STRBUF_INIT;3367FILE*logfp;3368long pos;3369int ret =0, at_tail =1;33703371 logfp =fopen(git_path("logs/%s", refname),"r");3372if(!logfp)3373return-1;33743375/* Jump to the end */3376if(fseek(logfp,0, SEEK_END) <0)3377returnerror("cannot seek back reflog for%s:%s",3378 refname,strerror(errno));3379 pos =ftell(logfp);3380while(!ret &&0< pos) {3381int cnt;3382size_t nread;3383char buf[BUFSIZ];3384char*endp, *scanp;33853386/* Fill next block from the end */3387 cnt = (sizeof(buf) < pos) ?sizeof(buf) : pos;3388if(fseek(logfp, pos - cnt, SEEK_SET))3389returnerror("cannot seek back reflog for%s:%s",3390 refname,strerror(errno));3391 nread =fread(buf, cnt,1, logfp);3392if(nread !=1)3393returnerror("cannot read%dbytes from reflog for%s:%s",3394 cnt, refname,strerror(errno));3395 pos -= cnt;33963397 scanp = endp = buf + cnt;3398if(at_tail && scanp[-1] =='\n')3399/* Looking at the final LF at the end of the file */3400 scanp--;3401 at_tail =0;34023403while(buf < scanp) {3404/*3405 * terminating LF of the previous line, or the beginning3406 * of the buffer.3407 */3408char*bp;34093410 bp =find_beginning_of_line(buf, scanp);34113412if(*bp =='\n') {3413/*3414 * The newline is the end of the previous line,3415 * so we know we have complete line starting3416 * at (bp + 1). Prefix it onto any prior data3417 * we collected for the line and process it.3418 */3419strbuf_splice(&sb,0,0, bp +1, endp - (bp +1));3420 scanp = bp;3421 endp = bp +1;3422 ret =show_one_reflog_ent(&sb, fn, cb_data);3423strbuf_reset(&sb);3424if(ret)3425break;3426}else if(!pos) {3427/*3428 * We are at the start of the buffer, and the3429 * start of the file; there is no previous3430 * line, and we have everything for this one.3431 * Process it, and we can end the loop.3432 */3433strbuf_splice(&sb,0,0, buf, endp - buf);3434 ret =show_one_reflog_ent(&sb, fn, cb_data);3435strbuf_reset(&sb);3436break;3437}34383439if(bp == buf) {3440/*3441 * We are at the start of the buffer, and there3442 * is more file to read backwards. Which means3443 * we are in the middle of a line. Note that we3444 * may get here even if *bp was a newline; that3445 * just means we are at the exact end of the3446 * previous line, rather than some spot in the3447 * middle.3448 *3449 * Save away what we have to be combined with3450 * the data from the next read.3451 */3452strbuf_splice(&sb,0,0, buf, endp - buf);3453break;3454}3455}34563457}3458if(!ret && sb.len)3459die("BUG: reverse reflog parser had leftover data");34603461fclose(logfp);3462strbuf_release(&sb);3463return ret;3464}34653466intfor_each_reflog_ent(const char*refname, each_reflog_ent_fn fn,void*cb_data)3467{3468FILE*logfp;3469struct strbuf sb = STRBUF_INIT;3470int ret =0;34713472 logfp =fopen(git_path("logs/%s", refname),"r");3473if(!logfp)3474return-1;34753476while(!ret && !strbuf_getwholeline(&sb, logfp,'\n'))3477 ret =show_one_reflog_ent(&sb, fn, cb_data);3478fclose(logfp);3479strbuf_release(&sb);3480return ret;3481}3482/*3483 * Call fn for each reflog in the namespace indicated by name. name3484 * must be empty or end with '/'. Name will be used as a scratch3485 * space, but its contents will be restored before return.3486 */3487static intdo_for_each_reflog(struct strbuf *name, each_ref_fn fn,void*cb_data)3488{3489DIR*d =opendir(git_path("logs/%s", name->buf));3490int retval =0;3491struct dirent *de;3492int oldlen = name->len;34933494if(!d)3495return name->len ? errno :0;34963497while((de =readdir(d)) != NULL) {3498struct stat st;34993500if(de->d_name[0] =='.')3501continue;3502if(ends_with(de->d_name,".lock"))3503continue;3504strbuf_addstr(name, de->d_name);3505if(stat(git_path("logs/%s", name->buf), &st) <0) {3506;/* silently ignore */3507}else{3508if(S_ISDIR(st.st_mode)) {3509strbuf_addch(name,'/');3510 retval =do_for_each_reflog(name, fn, cb_data);3511}else{3512unsigned char sha1[20];3513if(read_ref_full(name->buf,0, sha1, NULL))3514 retval =error("bad ref for%s", name->buf);3515else3516 retval =fn(name->buf, sha1,0, cb_data);3517}3518if(retval)3519break;3520}3521strbuf_setlen(name, oldlen);3522}3523closedir(d);3524return retval;3525}35263527intfor_each_reflog(each_ref_fn fn,void*cb_data)3528{3529int retval;3530struct strbuf name;3531strbuf_init(&name, PATH_MAX);3532 retval =do_for_each_reflog(&name, fn, cb_data);3533strbuf_release(&name);3534return retval;3535}35363537/**3538 * Information needed for a single ref update. Set new_sha1 to the new3539 * value or to null_sha1 to delete the ref. To check the old value3540 * while the ref is locked, set (flags & REF_HAVE_OLD) and set3541 * old_sha1 to the old value, or to null_sha1 to ensure the ref does3542 * not exist before update.3543 */3544struct ref_update {3545/*3546 * If (flags & REF_HAVE_NEW), set the reference to this value:3547 */3548unsigned char new_sha1[20];3549/*3550 * If (flags & REF_HAVE_OLD), check that the reference3551 * previously had this value:3552 */3553unsigned char old_sha1[20];3554/*3555 * One or more of REF_HAVE_NEW, REF_HAVE_OLD, REF_NODEREF,3556 * REF_DELETING, and REF_ISPRUNING:3557 */3558unsigned int flags;3559struct ref_lock *lock;3560int type;3561char*msg;3562const char refname[FLEX_ARRAY];3563};35643565/*3566 * Transaction states.3567 * OPEN: The transaction is in a valid state and can accept new updates.3568 * An OPEN transaction can be committed.3569 * CLOSED: A closed transaction is no longer active and no other operations3570 * than free can be used on it in this state.3571 * A transaction can either become closed by successfully committing3572 * an active transaction or if there is a failure while building3573 * the transaction thus rendering it failed/inactive.3574 */3575enum ref_transaction_state {3576 REF_TRANSACTION_OPEN =0,3577 REF_TRANSACTION_CLOSED =13578};35793580/*3581 * Data structure for holding a reference transaction, which can3582 * consist of checks and updates to multiple references, carried out3583 * as atomically as possible. This structure is opaque to callers.3584 */3585struct ref_transaction {3586struct ref_update **updates;3587size_t alloc;3588size_t nr;3589enum ref_transaction_state state;3590};35913592struct ref_transaction *ref_transaction_begin(struct strbuf *err)3593{3594assert(err);35953596returnxcalloc(1,sizeof(struct ref_transaction));3597}35983599voidref_transaction_free(struct ref_transaction *transaction)3600{3601int i;36023603if(!transaction)3604return;36053606for(i =0; i < transaction->nr; i++) {3607free(transaction->updates[i]->msg);3608free(transaction->updates[i]);3609}3610free(transaction->updates);3611free(transaction);3612}36133614static struct ref_update *add_update(struct ref_transaction *transaction,3615const char*refname)3616{3617size_t len =strlen(refname);3618struct ref_update *update =xcalloc(1,sizeof(*update) + len +1);36193620strcpy((char*)update->refname, refname);3621ALLOC_GROW(transaction->updates, transaction->nr +1, transaction->alloc);3622 transaction->updates[transaction->nr++] = update;3623return update;3624}36253626intref_transaction_update(struct ref_transaction *transaction,3627const char*refname,3628const unsigned char*new_sha1,3629const unsigned char*old_sha1,3630unsigned int flags,const char*msg,3631struct strbuf *err)3632{3633struct ref_update *update;36343635assert(err);36363637if(transaction->state != REF_TRANSACTION_OPEN)3638die("BUG: update called for transaction that is not open");36393640if(new_sha1 && !is_null_sha1(new_sha1) &&3641check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {3642strbuf_addf(err,"refusing to update ref with bad name%s",3643 refname);3644return-1;3645}36463647 update =add_update(transaction, refname);3648if(new_sha1) {3649hashcpy(update->new_sha1, new_sha1);3650 flags |= REF_HAVE_NEW;3651}3652if(old_sha1) {3653hashcpy(update->old_sha1, old_sha1);3654 flags |= REF_HAVE_OLD;3655}3656 update->flags = flags;3657if(msg)3658 update->msg =xstrdup(msg);3659return0;3660}36613662intref_transaction_create(struct ref_transaction *transaction,3663const char*refname,3664const unsigned char*new_sha1,3665unsigned int flags,const char*msg,3666struct strbuf *err)3667{3668if(!new_sha1 ||is_null_sha1(new_sha1))3669die("BUG: create called without valid new_sha1");3670returnref_transaction_update(transaction, refname, new_sha1,3671 null_sha1, flags, msg, err);3672}36733674intref_transaction_delete(struct ref_transaction *transaction,3675const char*refname,3676const unsigned char*old_sha1,3677unsigned int flags,const char*msg,3678struct strbuf *err)3679{3680if(old_sha1 &&is_null_sha1(old_sha1))3681die("BUG: delete called with old_sha1 set to zeros");3682returnref_transaction_update(transaction, refname,3683 null_sha1, old_sha1,3684 flags, msg, err);3685}36863687intref_transaction_verify(struct ref_transaction *transaction,3688const char*refname,3689const unsigned char*old_sha1,3690unsigned int flags,3691struct strbuf *err)3692{3693if(!old_sha1)3694die("BUG: verify called with old_sha1 set to NULL");3695returnref_transaction_update(transaction, refname,3696 NULL, old_sha1,3697 flags, NULL, err);3698}36993700intupdate_ref(const char*msg,const char*refname,3701const unsigned char*new_sha1,const unsigned char*old_sha1,3702unsigned int flags,enum action_on_err onerr)3703{3704struct ref_transaction *t;3705struct strbuf err = STRBUF_INIT;37063707 t =ref_transaction_begin(&err);3708if(!t ||3709ref_transaction_update(t, refname, new_sha1, old_sha1,3710 flags, msg, &err) ||3711ref_transaction_commit(t, &err)) {3712const char*str ="update_ref failed for ref '%s':%s";37133714ref_transaction_free(t);3715switch(onerr) {3716case UPDATE_REFS_MSG_ON_ERR:3717error(str, refname, err.buf);3718break;3719case UPDATE_REFS_DIE_ON_ERR:3720die(str, refname, err.buf);3721break;3722case UPDATE_REFS_QUIET_ON_ERR:3723break;3724}3725strbuf_release(&err);3726return1;3727}3728strbuf_release(&err);3729ref_transaction_free(t);3730return0;3731}37323733static intref_update_compare(const void*r1,const void*r2)3734{3735const struct ref_update *const*u1 = r1;3736const struct ref_update *const*u2 = r2;3737returnstrcmp((*u1)->refname, (*u2)->refname);3738}37393740static intref_update_reject_duplicates(struct ref_update **updates,int n,3741struct strbuf *err)3742{3743int i;37443745assert(err);37463747for(i =1; i < n; i++)3748if(!strcmp(updates[i -1]->refname, updates[i]->refname)) {3749strbuf_addf(err,3750"Multiple updates for ref '%s' not allowed.",3751 updates[i]->refname);3752return1;3753}3754return0;3755}37563757intref_transaction_commit(struct ref_transaction *transaction,3758struct strbuf *err)3759{3760int ret =0, i;3761int n = transaction->nr;3762struct ref_update **updates = transaction->updates;3763struct string_list refs_to_delete = STRING_LIST_INIT_NODUP;3764struct string_list_item *ref_to_delete;37653766assert(err);37673768if(transaction->state != REF_TRANSACTION_OPEN)3769die("BUG: commit called for transaction that is not open");37703771if(!n) {3772 transaction->state = REF_TRANSACTION_CLOSED;3773return0;3774}37753776/* Copy, sort, and reject duplicate refs */3777qsort(updates, n,sizeof(*updates), ref_update_compare);3778if(ref_update_reject_duplicates(updates, n, err)) {3779 ret = TRANSACTION_GENERIC_ERROR;3780goto cleanup;3781}37823783/* Acquire all locks while verifying old values */3784for(i =0; i < n; i++) {3785struct ref_update *update = updates[i];3786unsigned int flags = update->flags;37873788if((flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1))3789 flags |= REF_DELETING;3790 update->lock =lock_ref_sha1_basic(3791 update->refname,3792((update->flags & REF_HAVE_OLD) ?3793 update->old_sha1 : NULL),3794 NULL,3795 flags,3796&update->type);3797if(!update->lock) {3798 ret = (errno == ENOTDIR)3799? TRANSACTION_NAME_CONFLICT3800: TRANSACTION_GENERIC_ERROR;3801strbuf_addf(err,"Cannot lock the ref '%s'.",3802 update->refname);3803goto cleanup;3804}3805}38063807/* Perform updates first so live commits remain referenced */3808for(i =0; i < n; i++) {3809struct ref_update *update = updates[i];3810int flags = update->flags;38113812if((flags & REF_HAVE_NEW) && !is_null_sha1(update->new_sha1)) {3813int overwriting_symref = ((update->type & REF_ISSYMREF) &&3814(update->flags & REF_NODEREF));38153816if(!overwriting_symref3817&& !hashcmp(update->lock->old_sha1, update->new_sha1)) {3818/*3819 * The reference already has the desired3820 * value, so we don't need to write it.3821 */3822unlock_ref(update->lock);3823 update->lock = NULL;3824}else if(write_ref_sha1(update->lock, update->new_sha1,3825 update->msg)) {3826 update->lock = NULL;/* freed by write_ref_sha1 */3827strbuf_addf(err,"Cannot update the ref '%s'.",3828 update->refname);3829 ret = TRANSACTION_GENERIC_ERROR;3830goto cleanup;3831}else{3832/* freed by write_ref_sha1(): */3833 update->lock = NULL;3834}3835}3836}38373838/* Perform deletes now that updates are safely completed */3839for(i =0; i < n; i++) {3840struct ref_update *update = updates[i];3841int flags = update->flags;38423843if((flags & REF_HAVE_NEW) &&is_null_sha1(update->new_sha1)) {3844if(delete_ref_loose(update->lock, update->type, err)) {3845 ret = TRANSACTION_GENERIC_ERROR;3846goto cleanup;3847}38483849if(!(flags & REF_ISPRUNING))3850string_list_append(&refs_to_delete,3851 update->lock->ref_name);3852}3853}38543855if(repack_without_refs(&refs_to_delete, err)) {3856 ret = TRANSACTION_GENERIC_ERROR;3857goto cleanup;3858}3859for_each_string_list_item(ref_to_delete, &refs_to_delete)3860unlink_or_warn(git_path("logs/%s", ref_to_delete->string));3861clear_loose_ref_cache(&ref_cache);38623863cleanup:3864 transaction->state = REF_TRANSACTION_CLOSED;38653866for(i =0; i < n; i++)3867if(updates[i]->lock)3868unlock_ref(updates[i]->lock);3869string_list_clear(&refs_to_delete,0);3870return ret;3871}38723873char*shorten_unambiguous_ref(const char*refname,int strict)3874{3875int i;3876static char**scanf_fmts;3877static int nr_rules;3878char*short_name;38793880if(!nr_rules) {3881/*3882 * Pre-generate scanf formats from ref_rev_parse_rules[].3883 * Generate a format suitable for scanf from a3884 * ref_rev_parse_rules rule by interpolating "%s" at the3885 * location of the "%.*s".3886 */3887size_t total_len =0;3888size_t offset =0;38893890/* the rule list is NULL terminated, count them first */3891for(nr_rules =0; ref_rev_parse_rules[nr_rules]; nr_rules++)3892/* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */3893 total_len +=strlen(ref_rev_parse_rules[nr_rules]) -2+1;38943895 scanf_fmts =xmalloc(nr_rules *sizeof(char*) + total_len);38963897 offset =0;3898for(i =0; i < nr_rules; i++) {3899assert(offset < total_len);3900 scanf_fmts[i] = (char*)&scanf_fmts[nr_rules] + offset;3901 offset +=snprintf(scanf_fmts[i], total_len - offset,3902 ref_rev_parse_rules[i],2,"%s") +1;3903}3904}39053906/* bail out if there are no rules */3907if(!nr_rules)3908returnxstrdup(refname);39093910/* buffer for scanf result, at most refname must fit */3911 short_name =xstrdup(refname);39123913/* skip first rule, it will always match */3914for(i = nr_rules -1; i >0; --i) {3915int j;3916int rules_to_fail = i;3917int short_name_len;39183919if(1!=sscanf(refname, scanf_fmts[i], short_name))3920continue;39213922 short_name_len =strlen(short_name);39233924/*3925 * in strict mode, all (except the matched one) rules3926 * must fail to resolve to a valid non-ambiguous ref3927 */3928if(strict)3929 rules_to_fail = nr_rules;39303931/*3932 * check if the short name resolves to a valid ref,3933 * but use only rules prior to the matched one3934 */3935for(j =0; j < rules_to_fail; j++) {3936const char*rule = ref_rev_parse_rules[j];3937char refname[PATH_MAX];39383939/* skip matched rule */3940if(i == j)3941continue;39423943/*3944 * the short name is ambiguous, if it resolves3945 * (with this previous rule) to a valid ref3946 * read_ref() returns 0 on success3947 */3948mksnpath(refname,sizeof(refname),3949 rule, short_name_len, short_name);3950if(ref_exists(refname))3951break;3952}39533954/*3955 * short name is non-ambiguous if all previous rules3956 * haven't resolved to a valid ref3957 */3958if(j == rules_to_fail)3959return short_name;3960}39613962free(short_name);3963returnxstrdup(refname);3964}39653966static struct string_list *hide_refs;39673968intparse_hide_refs_config(const char*var,const char*value,const char*section)3969{3970if(!strcmp("transfer.hiderefs", var) ||3971/* NEEDSWORK: use parse_config_key() once both are merged */3972(starts_with(var, section) && var[strlen(section)] =='.'&&3973!strcmp(var +strlen(section),".hiderefs"))) {3974char*ref;3975int len;39763977if(!value)3978returnconfig_error_nonbool(var);3979 ref =xstrdup(value);3980 len =strlen(ref);3981while(len && ref[len -1] =='/')3982 ref[--len] ='\0';3983if(!hide_refs) {3984 hide_refs =xcalloc(1,sizeof(*hide_refs));3985 hide_refs->strdup_strings =1;3986}3987string_list_append(hide_refs, ref);3988}3989return0;3990}39913992intref_is_hidden(const char*refname)3993{3994struct string_list_item *item;39953996if(!hide_refs)3997return0;3998for_each_string_list_item(item, hide_refs) {3999int len;4000if(!starts_with(refname, item->string))4001continue;4002 len =strlen(item->string);4003if(!refname[len] || refname[len] =='/')4004return1;4005}4006return0;4007}40084009struct expire_reflog_cb {4010unsigned int flags;4011 reflog_expiry_should_prune_fn *should_prune_fn;4012void*policy_cb;4013FILE*newlog;4014unsigned char last_kept_sha1[20];4015};40164017static intexpire_reflog_ent(unsigned char*osha1,unsigned char*nsha1,4018const char*email,unsigned long timestamp,int tz,4019const char*message,void*cb_data)4020{4021struct expire_reflog_cb *cb = cb_data;4022struct expire_reflog_policy_cb *policy_cb = cb->policy_cb;40234024if(cb->flags & EXPIRE_REFLOGS_REWRITE)4025 osha1 = cb->last_kept_sha1;40264027if((*cb->should_prune_fn)(osha1, nsha1, email, timestamp, tz,4028 message, policy_cb)) {4029if(!cb->newlog)4030printf("would prune%s", message);4031else if(cb->flags & EXPIRE_REFLOGS_VERBOSE)4032printf("prune%s", message);4033}else{4034if(cb->newlog) {4035fprintf(cb->newlog,"%s %s %s %lu %+05d\t%s",4036sha1_to_hex(osha1),sha1_to_hex(nsha1),4037 email, timestamp, tz, message);4038hashcpy(cb->last_kept_sha1, nsha1);4039}4040if(cb->flags & EXPIRE_REFLOGS_VERBOSE)4041printf("keep%s", message);4042}4043return0;4044}40454046intreflog_expire(const char*refname,const unsigned char*sha1,4047unsigned int flags,4048 reflog_expiry_prepare_fn prepare_fn,4049 reflog_expiry_should_prune_fn should_prune_fn,4050 reflog_expiry_cleanup_fn cleanup_fn,4051void*policy_cb_data)4052{4053static struct lock_file reflog_lock;4054struct expire_reflog_cb cb;4055struct ref_lock *lock;4056char*log_file;4057int status =0;4058int type;40594060memset(&cb,0,sizeof(cb));4061 cb.flags = flags;4062 cb.policy_cb = policy_cb_data;4063 cb.should_prune_fn = should_prune_fn;40644065/*4066 * The reflog file is locked by holding the lock on the4067 * reference itself, plus we might need to update the4068 * reference if --updateref was specified:4069 */4070 lock =lock_ref_sha1_basic(refname, sha1, NULL,0, &type);4071if(!lock)4072returnerror("cannot lock ref '%s'", refname);4073if(!reflog_exists(refname)) {4074unlock_ref(lock);4075return0;4076}40774078 log_file =git_pathdup("logs/%s", refname);4079if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4080/*4081 * Even though holding $GIT_DIR/logs/$reflog.lock has4082 * no locking implications, we use the lock_file4083 * machinery here anyway because it does a lot of the4084 * work we need, including cleaning up if the program4085 * exits unexpectedly.4086 */4087if(hold_lock_file_for_update(&reflog_lock, log_file,0) <0) {4088struct strbuf err = STRBUF_INIT;4089unable_to_lock_message(log_file, errno, &err);4090error("%s", err.buf);4091strbuf_release(&err);4092goto failure;4093}4094 cb.newlog =fdopen_lock_file(&reflog_lock,"w");4095if(!cb.newlog) {4096error("cannot fdopen%s(%s)",4097 reflog_lock.filename.buf,strerror(errno));4098goto failure;4099}4100}41014102(*prepare_fn)(refname, sha1, cb.policy_cb);4103for_each_reflog_ent(refname, expire_reflog_ent, &cb);4104(*cleanup_fn)(cb.policy_cb);41054106if(!(flags & EXPIRE_REFLOGS_DRY_RUN)) {4107/*4108 * It doesn't make sense to adjust a reference pointed4109 * to by a symbolic ref based on expiring entries in4110 * the symbolic reference's reflog. Nor can we update4111 * a reference if there are no remaining reflog4112 * entries.4113 */4114int update = (flags & EXPIRE_REFLOGS_UPDATE_REF) &&4115!(type & REF_ISSYMREF) &&4116!is_null_sha1(cb.last_kept_sha1);41174118if(close_lock_file(&reflog_lock)) {4119 status |=error("couldn't write%s:%s", log_file,4120strerror(errno));4121}else if(update &&4122(write_in_full(lock->lock_fd,4123sha1_to_hex(cb.last_kept_sha1),40) !=40||4124write_str_in_full(lock->lock_fd,"\n") !=1||4125close_ref(lock) <0)) {4126 status |=error("couldn't write%s",4127 lock->lk->filename.buf);4128rollback_lock_file(&reflog_lock);4129}else if(commit_lock_file(&reflog_lock)) {4130 status |=error("unable to commit reflog '%s' (%s)",4131 log_file,strerror(errno));4132}else if(update &&commit_ref(lock)) {4133 status |=error("couldn't set%s", lock->ref_name);4134}4135}4136free(log_file);4137unlock_ref(lock);4138return status;41394140 failure:4141rollback_lock_file(&reflog_lock);4142free(log_file);4143unlock_ref(lock);4144return-1;4145}