1/* 2 * GIT - The information manager from hell 3 * 4 * Copyright (C) Linus Torvalds, 2005 5 */ 6#define NO_THE_INDEX_COMPATIBILITY_MACROS 7#include"cache.h" 8#include"cache-tree.h" 9#include"refs.h" 10#include"dir.h" 11#include"tree.h" 12#include"commit.h" 13#include"blob.h" 14#include"resolve-undo.h" 15 16static struct cache_entry *refresh_cache_entry(struct cache_entry *ce,int really); 17 18/* Index extensions. 19 * 20 * The first letter should be 'A'..'Z' for extensions that are not 21 * necessary for a correct operation (i.e. optimization data). 22 * When new extensions are added that _needs_ to be understood in 23 * order to correctly interpret the index file, pick character that 24 * is outside the range, to cause the reader to abort. 25 */ 26 27#define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) ) 28#define CACHE_EXT_TREE 0x54524545/* "TREE" */ 29#define CACHE_EXT_RESOLVE_UNDO 0x52455543/* "REUC" */ 30 31struct index_state the_index; 32 33static voidset_index_entry(struct index_state *istate,int nr,struct cache_entry *ce) 34{ 35 istate->cache[nr] = ce; 36add_name_hash(istate, ce); 37} 38 39static voidreplace_index_entry(struct index_state *istate,int nr,struct cache_entry *ce) 40{ 41struct cache_entry *old = istate->cache[nr]; 42 43remove_name_hash(old); 44set_index_entry(istate, nr, ce); 45 istate->cache_changed =1; 46} 47 48voidrename_index_entry_at(struct index_state *istate,int nr,const char*new_name) 49{ 50struct cache_entry *old = istate->cache[nr], *new; 51int namelen =strlen(new_name); 52 53new=xmalloc(cache_entry_size(namelen)); 54copy_cache_entry(new, old); 55new->ce_flags &= ~(CE_STATE_MASK | CE_NAMEMASK); 56new->ce_flags |= (namelen >= CE_NAMEMASK ? CE_NAMEMASK : namelen); 57memcpy(new->name, new_name, namelen +1); 58 59cache_tree_invalidate_path(istate->cache_tree, old->name); 60remove_index_entry_at(istate, nr); 61add_index_entry(istate,new, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE); 62} 63 64/* 65 * This only updates the "non-critical" parts of the directory 66 * cache, ie the parts that aren't tracked by GIT, and only used 67 * to validate the cache. 68 */ 69voidfill_stat_cache_info(struct cache_entry *ce,struct stat *st) 70{ 71 ce->ce_ctime.sec = (unsigned int)st->st_ctime; 72 ce->ce_mtime.sec = (unsigned int)st->st_mtime; 73 ce->ce_ctime.nsec =ST_CTIME_NSEC(*st); 74 ce->ce_mtime.nsec =ST_MTIME_NSEC(*st); 75 ce->ce_dev = st->st_dev; 76 ce->ce_ino = st->st_ino; 77 ce->ce_uid = st->st_uid; 78 ce->ce_gid = st->st_gid; 79 ce->ce_size = st->st_size; 80 81if(assume_unchanged) 82 ce->ce_flags |= CE_VALID; 83 84if(S_ISREG(st->st_mode)) 85ce_mark_uptodate(ce); 86} 87 88static intce_compare_data(struct cache_entry *ce,struct stat *st) 89{ 90int match = -1; 91int fd =open(ce->name, O_RDONLY); 92 93if(fd >=0) { 94unsigned char sha1[20]; 95if(!index_fd(sha1, fd, st, OBJ_BLOB, ce->name,0)) 96 match =hashcmp(sha1, ce->sha1); 97/* index_fd() closed the file descriptor already */ 98} 99return match; 100} 101 102static intce_compare_link(struct cache_entry *ce,size_t expected_size) 103{ 104int match = -1; 105void*buffer; 106unsigned long size; 107enum object_type type; 108struct strbuf sb = STRBUF_INIT; 109 110if(strbuf_readlink(&sb, ce->name, expected_size)) 111return-1; 112 113 buffer =read_sha1_file(ce->sha1, &type, &size); 114if(buffer) { 115if(size == sb.len) 116 match =memcmp(buffer, sb.buf, size); 117free(buffer); 118} 119strbuf_release(&sb); 120return match; 121} 122 123static intce_compare_gitlink(struct cache_entry *ce) 124{ 125unsigned char sha1[20]; 126 127/* 128 * We don't actually require that the .git directory 129 * under GITLINK directory be a valid git directory. It 130 * might even be missing (in case nobody populated that 131 * sub-project). 132 * 133 * If so, we consider it always to match. 134 */ 135if(resolve_gitlink_ref(ce->name,"HEAD", sha1) <0) 136return0; 137returnhashcmp(sha1, ce->sha1); 138} 139 140static intce_modified_check_fs(struct cache_entry *ce,struct stat *st) 141{ 142switch(st->st_mode & S_IFMT) { 143case S_IFREG: 144if(ce_compare_data(ce, st)) 145return DATA_CHANGED; 146break; 147case S_IFLNK: 148if(ce_compare_link(ce,xsize_t(st->st_size))) 149return DATA_CHANGED; 150break; 151case S_IFDIR: 152if(S_ISGITLINK(ce->ce_mode)) 153returnce_compare_gitlink(ce) ? DATA_CHANGED :0; 154default: 155return TYPE_CHANGED; 156} 157return0; 158} 159 160static intis_empty_blob_sha1(const unsigned char*sha1) 161{ 162static const unsigned char empty_blob_sha1[20] = { 1630xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b, 1640x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91 165}; 166 167return!hashcmp(sha1, empty_blob_sha1); 168} 169 170static intce_match_stat_basic(struct cache_entry *ce,struct stat *st) 171{ 172unsigned int changed =0; 173 174if(ce->ce_flags & CE_REMOVE) 175return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED; 176 177switch(ce->ce_mode & S_IFMT) { 178case S_IFREG: 179 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED :0; 180/* We consider only the owner x bit to be relevant for 181 * "mode changes" 182 */ 183if(trust_executable_bit && 184(0100& (ce->ce_mode ^ st->st_mode))) 185 changed |= MODE_CHANGED; 186break; 187case S_IFLNK: 188if(!S_ISLNK(st->st_mode) && 189(has_symlinks || !S_ISREG(st->st_mode))) 190 changed |= TYPE_CHANGED; 191break; 192case S_IFGITLINK: 193/* We ignore most of the st_xxx fields for gitlinks */ 194if(!S_ISDIR(st->st_mode)) 195 changed |= TYPE_CHANGED; 196else if(ce_compare_gitlink(ce)) 197 changed |= DATA_CHANGED; 198return changed; 199default: 200die("internal error: ce_mode is%o", ce->ce_mode); 201} 202if(ce->ce_mtime.sec != (unsigned int)st->st_mtime) 203 changed |= MTIME_CHANGED; 204if(trust_ctime && ce->ce_ctime.sec != (unsigned int)st->st_ctime) 205 changed |= CTIME_CHANGED; 206 207#ifdef USE_NSEC 208if(ce->ce_mtime.nsec !=ST_MTIME_NSEC(*st)) 209 changed |= MTIME_CHANGED; 210if(trust_ctime && ce->ce_ctime.nsec !=ST_CTIME_NSEC(*st)) 211 changed |= CTIME_CHANGED; 212#endif 213 214if(ce->ce_uid != (unsigned int) st->st_uid || 215 ce->ce_gid != (unsigned int) st->st_gid) 216 changed |= OWNER_CHANGED; 217if(ce->ce_ino != (unsigned int) st->st_ino) 218 changed |= INODE_CHANGED; 219 220#ifdef USE_STDEV 221/* 222 * st_dev breaks on network filesystems where different 223 * clients will have different views of what "device" 224 * the filesystem is on 225 */ 226if(ce->ce_dev != (unsigned int) st->st_dev) 227 changed |= INODE_CHANGED; 228#endif 229 230if(ce->ce_size != (unsigned int) st->st_size) 231 changed |= DATA_CHANGED; 232 233/* Racily smudged entry? */ 234if(!ce->ce_size) { 235if(!is_empty_blob_sha1(ce->sha1)) 236 changed |= DATA_CHANGED; 237} 238 239return changed; 240} 241 242static intis_racy_timestamp(const struct index_state *istate,struct cache_entry *ce) 243{ 244return(!S_ISGITLINK(ce->ce_mode) && 245 istate->timestamp.sec && 246#ifdef USE_NSEC 247/* nanosecond timestamped files can also be racy! */ 248(istate->timestamp.sec < ce->ce_mtime.sec || 249(istate->timestamp.sec == ce->ce_mtime.sec && 250 istate->timestamp.nsec <= ce->ce_mtime.nsec)) 251#else 252 istate->timestamp.sec <= ce->ce_mtime.sec 253#endif 254); 255} 256 257intie_match_stat(const struct index_state *istate, 258struct cache_entry *ce,struct stat *st, 259unsigned int options) 260{ 261unsigned int changed; 262int ignore_valid = options & CE_MATCH_IGNORE_VALID; 263int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE; 264int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY; 265 266/* 267 * If it's marked as always valid in the index, it's 268 * valid whatever the checked-out copy says. 269 * 270 * skip-worktree has the same effect with higher precedence 271 */ 272if(!ignore_skip_worktree &&ce_skip_worktree(ce)) 273return0; 274if(!ignore_valid && (ce->ce_flags & CE_VALID)) 275return0; 276 277/* 278 * Intent-to-add entries have not been added, so the index entry 279 * by definition never matches what is in the work tree until it 280 * actually gets added. 281 */ 282if(ce->ce_flags & CE_INTENT_TO_ADD) 283return DATA_CHANGED | TYPE_CHANGED | MODE_CHANGED; 284 285 changed =ce_match_stat_basic(ce, st); 286 287/* 288 * Within 1 second of this sequence: 289 * echo xyzzy >file && git-update-index --add file 290 * running this command: 291 * echo frotz >file 292 * would give a falsely clean cache entry. The mtime and 293 * length match the cache, and other stat fields do not change. 294 * 295 * We could detect this at update-index time (the cache entry 296 * being registered/updated records the same time as "now") 297 * and delay the return from git-update-index, but that would 298 * effectively mean we can make at most one commit per second, 299 * which is not acceptable. Instead, we check cache entries 300 * whose mtime are the same as the index file timestamp more 301 * carefully than others. 302 */ 303if(!changed &&is_racy_timestamp(istate, ce)) { 304if(assume_racy_is_modified) 305 changed |= DATA_CHANGED; 306else 307 changed |=ce_modified_check_fs(ce, st); 308} 309 310return changed; 311} 312 313intie_modified(const struct index_state *istate, 314struct cache_entry *ce,struct stat *st,unsigned int options) 315{ 316int changed, changed_fs; 317 318 changed =ie_match_stat(istate, ce, st, options); 319if(!changed) 320return0; 321/* 322 * If the mode or type has changed, there's no point in trying 323 * to refresh the entry - it's not going to match 324 */ 325if(changed & (MODE_CHANGED | TYPE_CHANGED)) 326return changed; 327 328/* 329 * Immediately after read-tree or update-index --cacheinfo, 330 * the length field is zero, as we have never even read the 331 * lstat(2) information once, and we cannot trust DATA_CHANGED 332 * returned by ie_match_stat() which in turn was returned by 333 * ce_match_stat_basic() to signal that the filesize of the 334 * blob changed. We have to actually go to the filesystem to 335 * see if the contents match, and if so, should answer "unchanged". 336 * 337 * The logic does not apply to gitlinks, as ce_match_stat_basic() 338 * already has checked the actual HEAD from the filesystem in the 339 * subproject. If ie_match_stat() already said it is different, 340 * then we know it is. 341 */ 342if((changed & DATA_CHANGED) && 343(S_ISGITLINK(ce->ce_mode) || ce->ce_size !=0)) 344return changed; 345 346 changed_fs =ce_modified_check_fs(ce, st); 347if(changed_fs) 348return changed | changed_fs; 349return0; 350} 351 352intbase_name_compare(const char*name1,int len1,int mode1, 353const char*name2,int len2,int mode2) 354{ 355unsigned char c1, c2; 356int len = len1 < len2 ? len1 : len2; 357int cmp; 358 359 cmp =memcmp(name1, name2, len); 360if(cmp) 361return cmp; 362 c1 = name1[len]; 363 c2 = name2[len]; 364if(!c1 &&S_ISDIR(mode1)) 365 c1 ='/'; 366if(!c2 &&S_ISDIR(mode2)) 367 c2 ='/'; 368return(c1 < c2) ? -1: (c1 > c2) ?1:0; 369} 370 371/* 372 * df_name_compare() is identical to base_name_compare(), except it 373 * compares conflicting directory/file entries as equal. Note that 374 * while a directory name compares as equal to a regular file, they 375 * then individually compare _differently_ to a filename that has 376 * a dot after the basename (because '\0' < '.' < '/'). 377 * 378 * This is used by routines that want to traverse the git namespace 379 * but then handle conflicting entries together when possible. 380 */ 381intdf_name_compare(const char*name1,int len1,int mode1, 382const char*name2,int len2,int mode2) 383{ 384int len = len1 < len2 ? len1 : len2, cmp; 385unsigned char c1, c2; 386 387 cmp =memcmp(name1, name2, len); 388if(cmp) 389return cmp; 390/* Directories and files compare equal (same length, same name) */ 391if(len1 == len2) 392return0; 393 c1 = name1[len]; 394if(!c1 &&S_ISDIR(mode1)) 395 c1 ='/'; 396 c2 = name2[len]; 397if(!c2 &&S_ISDIR(mode2)) 398 c2 ='/'; 399if(c1 =='/'&& !c2) 400return0; 401if(c2 =='/'&& !c1) 402return0; 403return c1 - c2; 404} 405 406intcache_name_compare(const char*name1,int flags1,const char*name2,int flags2) 407{ 408int len1 = flags1 & CE_NAMEMASK; 409int len2 = flags2 & CE_NAMEMASK; 410int len = len1 < len2 ? len1 : len2; 411int cmp; 412 413 cmp =memcmp(name1, name2, len); 414if(cmp) 415return cmp; 416if(len1 < len2) 417return-1; 418if(len1 > len2) 419return1; 420 421/* Compare stages */ 422 flags1 &= CE_STAGEMASK; 423 flags2 &= CE_STAGEMASK; 424 425if(flags1 < flags2) 426return-1; 427if(flags1 > flags2) 428return1; 429return0; 430} 431 432intindex_name_pos(const struct index_state *istate,const char*name,int namelen) 433{ 434int first, last; 435 436 first =0; 437 last = istate->cache_nr; 438while(last > first) { 439int next = (last + first) >>1; 440struct cache_entry *ce = istate->cache[next]; 441int cmp =cache_name_compare(name, namelen, ce->name, ce->ce_flags); 442if(!cmp) 443return next; 444if(cmp <0) { 445 last = next; 446continue; 447} 448 first = next+1; 449} 450return-first-1; 451} 452 453/* Remove entry, return true if there are more entries to go.. */ 454intremove_index_entry_at(struct index_state *istate,int pos) 455{ 456struct cache_entry *ce = istate->cache[pos]; 457 458record_resolve_undo(istate, ce); 459remove_name_hash(ce); 460 istate->cache_changed =1; 461 istate->cache_nr--; 462if(pos >= istate->cache_nr) 463return0; 464memmove(istate->cache + pos, 465 istate->cache + pos +1, 466(istate->cache_nr - pos) *sizeof(struct cache_entry *)); 467return1; 468} 469 470/* 471 * Remove all cache ententries marked for removal, that is where 472 * CE_REMOVE is set in ce_flags. This is much more effective than 473 * calling remove_index_entry_at() for each entry to be removed. 474 */ 475voidremove_marked_cache_entries(struct index_state *istate) 476{ 477struct cache_entry **ce_array = istate->cache; 478unsigned int i, j; 479 480for(i = j =0; i < istate->cache_nr; i++) { 481if(ce_array[i]->ce_flags & CE_REMOVE) 482remove_name_hash(ce_array[i]); 483else 484 ce_array[j++] = ce_array[i]; 485} 486 istate->cache_changed =1; 487 istate->cache_nr = j; 488} 489 490intremove_file_from_index(struct index_state *istate,const char*path) 491{ 492int pos =index_name_pos(istate, path,strlen(path)); 493if(pos <0) 494 pos = -pos-1; 495cache_tree_invalidate_path(istate->cache_tree, path); 496while(pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path)) 497remove_index_entry_at(istate, pos); 498return0; 499} 500 501static intcompare_name(struct cache_entry *ce,const char*path,int namelen) 502{ 503return namelen !=ce_namelen(ce) ||memcmp(path, ce->name, namelen); 504} 505 506static intindex_name_pos_also_unmerged(struct index_state *istate, 507const char*path,int namelen) 508{ 509int pos =index_name_pos(istate, path, namelen); 510struct cache_entry *ce; 511 512if(pos >=0) 513return pos; 514 515/* maybe unmerged? */ 516 pos = -1- pos; 517if(pos >= istate->cache_nr || 518compare_name((ce = istate->cache[pos]), path, namelen)) 519return-1; 520 521/* order of preference: stage 2, 1, 3 */ 522if(ce_stage(ce) ==1&& pos +1< istate->cache_nr && 523ce_stage((ce = istate->cache[pos +1])) ==2&& 524!compare_name(ce, path, namelen)) 525 pos++; 526return pos; 527} 528 529static intdifferent_name(struct cache_entry *ce,struct cache_entry *alias) 530{ 531int len =ce_namelen(ce); 532returnce_namelen(alias) != len ||memcmp(ce->name, alias->name, len); 533} 534 535/* 536 * If we add a filename that aliases in the cache, we will use the 537 * name that we already have - but we don't want to update the same 538 * alias twice, because that implies that there were actually two 539 * different files with aliasing names! 540 * 541 * So we use the CE_ADDED flag to verify that the alias was an old 542 * one before we accept it as 543 */ 544static struct cache_entry *create_alias_ce(struct cache_entry *ce,struct cache_entry *alias) 545{ 546int len; 547struct cache_entry *new; 548 549if(alias->ce_flags & CE_ADDED) 550die("Will not add file alias '%s' ('%s' already exists in index)", ce->name, alias->name); 551 552/* Ok, create the new entry using the name of the existing alias */ 553 len =ce_namelen(alias); 554new=xcalloc(1,cache_entry_size(len)); 555memcpy(new->name, alias->name, len); 556copy_cache_entry(new, ce); 557free(ce); 558return new; 559} 560 561static voidrecord_intent_to_add(struct cache_entry *ce) 562{ 563unsigned char sha1[20]; 564if(write_sha1_file("",0, blob_type, sha1)) 565die("cannot create an empty blob in the object database"); 566hashcpy(ce->sha1, sha1); 567} 568 569intadd_to_index(struct index_state *istate,const char*path,struct stat *st,int flags) 570{ 571int size, namelen, was_same; 572 mode_t st_mode = st->st_mode; 573struct cache_entry *ce, *alias; 574unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_IGNORE_SKIP_WORKTREE|CE_MATCH_RACY_IS_DIRTY; 575int verbose = flags & (ADD_CACHE_VERBOSE | ADD_CACHE_PRETEND); 576int pretend = flags & ADD_CACHE_PRETEND; 577int intent_only = flags & ADD_CACHE_INTENT; 578int add_option = (ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE| 579(intent_only ? ADD_CACHE_NEW_ONLY :0)); 580 581if(!S_ISREG(st_mode) && !S_ISLNK(st_mode) && !S_ISDIR(st_mode)) 582returnerror("%s: can only add regular files, symbolic links or git-directories", path); 583 584 namelen =strlen(path); 585if(S_ISDIR(st_mode)) { 586while(namelen && path[namelen-1] =='/') 587 namelen--; 588} 589 size =cache_entry_size(namelen); 590 ce =xcalloc(1, size); 591memcpy(ce->name, path, namelen); 592 ce->ce_flags = namelen; 593if(!intent_only) 594fill_stat_cache_info(ce, st); 595else 596 ce->ce_flags |= CE_INTENT_TO_ADD; 597 598if(trust_executable_bit && has_symlinks) 599 ce->ce_mode =create_ce_mode(st_mode); 600else{ 601/* If there is an existing entry, pick the mode bits and type 602 * from it, otherwise assume unexecutable regular file. 603 */ 604struct cache_entry *ent; 605int pos =index_name_pos_also_unmerged(istate, path, namelen); 606 607 ent = (0<= pos) ? istate->cache[pos] : NULL; 608 ce->ce_mode =ce_mode_from_stat(ent, st_mode); 609} 610 611/* When core.ignorecase=true, determine if a directory of the same name but differing 612 * case already exists within the Git repository. If it does, ensure the directory 613 * case of the file being added to the repository matches (is folded into) the existing 614 * entry's directory case. 615 */ 616if(ignore_case) { 617const char*startPtr = ce->name; 618const char*ptr = startPtr; 619while(*ptr) { 620while(*ptr && *ptr !='/') 621++ptr; 622if(*ptr =='/') { 623struct cache_entry *foundce; 624++ptr; 625 foundce =index_name_exists(&the_index, ce->name, ptr - ce->name, ignore_case); 626if(foundce) { 627memcpy((void*)startPtr, foundce->name + (startPtr - ce->name), ptr - startPtr); 628 startPtr = ptr; 629} 630} 631} 632} 633 634 alias =index_name_exists(istate, ce->name,ce_namelen(ce), ignore_case); 635if(alias && !ce_stage(alias) && !ie_match_stat(istate, alias, st, ce_option)) { 636/* Nothing changed, really */ 637free(ce); 638if(!S_ISGITLINK(alias->ce_mode)) 639ce_mark_uptodate(alias); 640 alias->ce_flags |= CE_ADDED; 641return0; 642} 643if(!intent_only) { 644if(index_path(ce->sha1, path, st, HASH_WRITE_OBJECT)) 645returnerror("unable to index file%s", path); 646}else 647record_intent_to_add(ce); 648 649if(ignore_case && alias &&different_name(ce, alias)) 650 ce =create_alias_ce(ce, alias); 651 ce->ce_flags |= CE_ADDED; 652 653/* It was suspected to be racily clean, but it turns out to be Ok */ 654 was_same = (alias && 655!ce_stage(alias) && 656!hashcmp(alias->sha1, ce->sha1) && 657 ce->ce_mode == alias->ce_mode); 658 659if(pretend) 660; 661else if(add_index_entry(istate, ce, add_option)) 662returnerror("unable to add%sto index",path); 663if(verbose && !was_same) 664printf("add '%s'\n", path); 665return0; 666} 667 668intadd_file_to_index(struct index_state *istate,const char*path,int flags) 669{ 670struct stat st; 671if(lstat(path, &st)) 672die_errno("unable to stat '%s'", path); 673returnadd_to_index(istate, path, &st, flags); 674} 675 676struct cache_entry *make_cache_entry(unsigned int mode, 677const unsigned char*sha1,const char*path,int stage, 678int refresh) 679{ 680int size, len; 681struct cache_entry *ce; 682 683if(!verify_path(path)) { 684error("Invalid path '%s'", path); 685return NULL; 686} 687 688 len =strlen(path); 689 size =cache_entry_size(len); 690 ce =xcalloc(1, size); 691 692hashcpy(ce->sha1, sha1); 693memcpy(ce->name, path, len); 694 ce->ce_flags =create_ce_flags(len, stage); 695 ce->ce_mode =create_ce_mode(mode); 696 697if(refresh) 698returnrefresh_cache_entry(ce,0); 699 700return ce; 701} 702 703intce_same_name(struct cache_entry *a,struct cache_entry *b) 704{ 705int len =ce_namelen(a); 706returnce_namelen(b) == len && !memcmp(a->name, b->name, len); 707} 708 709intce_path_match(const struct cache_entry *ce,const struct pathspec *pathspec) 710{ 711returnmatch_pathspec_depth(pathspec, ce->name,ce_namelen(ce),0, NULL); 712} 713 714/* 715 * We fundamentally don't like some paths: we don't want 716 * dot or dot-dot anywhere, and for obvious reasons don't 717 * want to recurse into ".git" either. 718 * 719 * Also, we don't want double slashes or slashes at the 720 * end that can make pathnames ambiguous. 721 */ 722static intverify_dotfile(const char*rest) 723{ 724/* 725 * The first character was '.', but that 726 * has already been discarded, we now test 727 * the rest. 728 */ 729 730/* "." is not allowed */ 731if(*rest =='\0'||is_dir_sep(*rest)) 732return0; 733 734switch(*rest) { 735/* 736 * ".git" followed by NUL or slash is bad. This 737 * shares the path end test with the ".." case. 738 */ 739case'g': 740if(rest[1] !='i') 741break; 742if(rest[2] !='t') 743break; 744 rest +=2; 745/* fallthrough */ 746case'.': 747if(rest[1] =='\0'||is_dir_sep(rest[1])) 748return0; 749} 750return1; 751} 752 753intverify_path(const char*path) 754{ 755char c; 756 757if(has_dos_drive_prefix(path)) 758return0; 759 760goto inside; 761for(;;) { 762if(!c) 763return1; 764if(is_dir_sep(c)) { 765inside: 766 c = *path++; 767if((c =='.'&& !verify_dotfile(path)) || 768is_dir_sep(c) || c =='\0') 769return0; 770} 771 c = *path++; 772} 773} 774 775/* 776 * Do we have another file that has the beginning components being a 777 * proper superset of the name we're trying to add? 778 */ 779static inthas_file_name(struct index_state *istate, 780const struct cache_entry *ce,int pos,int ok_to_replace) 781{ 782int retval =0; 783int len =ce_namelen(ce); 784int stage =ce_stage(ce); 785const char*name = ce->name; 786 787while(pos < istate->cache_nr) { 788struct cache_entry *p = istate->cache[pos++]; 789 790if(len >=ce_namelen(p)) 791break; 792if(memcmp(name, p->name, len)) 793break; 794if(ce_stage(p) != stage) 795continue; 796if(p->name[len] !='/') 797continue; 798if(p->ce_flags & CE_REMOVE) 799continue; 800 retval = -1; 801if(!ok_to_replace) 802break; 803remove_index_entry_at(istate, --pos); 804} 805return retval; 806} 807 808/* 809 * Do we have another file with a pathname that is a proper 810 * subset of the name we're trying to add? 811 */ 812static inthas_dir_name(struct index_state *istate, 813const struct cache_entry *ce,int pos,int ok_to_replace) 814{ 815int retval =0; 816int stage =ce_stage(ce); 817const char*name = ce->name; 818const char*slash = name +ce_namelen(ce); 819 820for(;;) { 821int len; 822 823for(;;) { 824if(*--slash =='/') 825break; 826if(slash <= ce->name) 827return retval; 828} 829 len = slash - name; 830 831 pos =index_name_pos(istate, name,create_ce_flags(len, stage)); 832if(pos >=0) { 833/* 834 * Found one, but not so fast. This could 835 * be a marker that says "I was here, but 836 * I am being removed". Such an entry is 837 * not a part of the resulting tree, and 838 * it is Ok to have a directory at the same 839 * path. 840 */ 841if(!(istate->cache[pos]->ce_flags & CE_REMOVE)) { 842 retval = -1; 843if(!ok_to_replace) 844break; 845remove_index_entry_at(istate, pos); 846continue; 847} 848} 849else 850 pos = -pos-1; 851 852/* 853 * Trivial optimization: if we find an entry that 854 * already matches the sub-directory, then we know 855 * we're ok, and we can exit. 856 */ 857while(pos < istate->cache_nr) { 858struct cache_entry *p = istate->cache[pos]; 859if((ce_namelen(p) <= len) || 860(p->name[len] !='/') || 861memcmp(p->name, name, len)) 862break;/* not our subdirectory */ 863if(ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE)) 864/* 865 * p is at the same stage as our entry, and 866 * is a subdirectory of what we are looking 867 * at, so we cannot have conflicts at our 868 * level or anything shorter. 869 */ 870return retval; 871 pos++; 872} 873} 874return retval; 875} 876 877/* We may be in a situation where we already have path/file and path 878 * is being added, or we already have path and path/file is being 879 * added. Either one would result in a nonsense tree that has path 880 * twice when git-write-tree tries to write it out. Prevent it. 881 * 882 * If ok-to-replace is specified, we remove the conflicting entries 883 * from the cache so the caller should recompute the insert position. 884 * When this happens, we return non-zero. 885 */ 886static intcheck_file_directory_conflict(struct index_state *istate, 887const struct cache_entry *ce, 888int pos,int ok_to_replace) 889{ 890int retval; 891 892/* 893 * When ce is an "I am going away" entry, we allow it to be added 894 */ 895if(ce->ce_flags & CE_REMOVE) 896return0; 897 898/* 899 * We check if the path is a sub-path of a subsequent pathname 900 * first, since removing those will not change the position 901 * in the array. 902 */ 903 retval =has_file_name(istate, ce, pos, ok_to_replace); 904 905/* 906 * Then check if the path might have a clashing sub-directory 907 * before it. 908 */ 909return retval +has_dir_name(istate, ce, pos, ok_to_replace); 910} 911 912static intadd_index_entry_with_check(struct index_state *istate,struct cache_entry *ce,int option) 913{ 914int pos; 915int ok_to_add = option & ADD_CACHE_OK_TO_ADD; 916int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE; 917int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK; 918int new_only = option & ADD_CACHE_NEW_ONLY; 919 920cache_tree_invalidate_path(istate->cache_tree, ce->name); 921 pos =index_name_pos(istate, ce->name, ce->ce_flags); 922 923/* existing match? Just replace it. */ 924if(pos >=0) { 925if(!new_only) 926replace_index_entry(istate, pos, ce); 927return0; 928} 929 pos = -pos-1; 930 931/* 932 * Inserting a merged entry ("stage 0") into the index 933 * will always replace all non-merged entries.. 934 */ 935if(pos < istate->cache_nr &&ce_stage(ce) ==0) { 936while(ce_same_name(istate->cache[pos], ce)) { 937 ok_to_add =1; 938if(!remove_index_entry_at(istate, pos)) 939break; 940} 941} 942 943if(!ok_to_add) 944return-1; 945if(!verify_path(ce->name)) 946returnerror("Invalid path '%s'", ce->name); 947 948if(!skip_df_check && 949check_file_directory_conflict(istate, ce, pos, ok_to_replace)) { 950if(!ok_to_replace) 951returnerror("'%s' appears as both a file and as a directory", 952 ce->name); 953 pos =index_name_pos(istate, ce->name, ce->ce_flags); 954 pos = -pos-1; 955} 956return pos +1; 957} 958 959intadd_index_entry(struct index_state *istate,struct cache_entry *ce,int option) 960{ 961int pos; 962 963if(option & ADD_CACHE_JUST_APPEND) 964 pos = istate->cache_nr; 965else{ 966int ret; 967 ret =add_index_entry_with_check(istate, ce, option); 968if(ret <=0) 969return ret; 970 pos = ret -1; 971} 972 973/* Make sure the array is big enough .. */ 974if(istate->cache_nr == istate->cache_alloc) { 975 istate->cache_alloc =alloc_nr(istate->cache_alloc); 976 istate->cache =xrealloc(istate->cache, 977 istate->cache_alloc *sizeof(struct cache_entry *)); 978} 979 980/* Add it in.. */ 981 istate->cache_nr++; 982if(istate->cache_nr > pos +1) 983memmove(istate->cache + pos +1, 984 istate->cache + pos, 985(istate->cache_nr - pos -1) *sizeof(ce)); 986set_index_entry(istate, pos, ce); 987 istate->cache_changed =1; 988return0; 989} 990 991/* 992 * "refresh" does not calculate a new sha1 file or bring the 993 * cache up-to-date for mode/content changes. But what it 994 * _does_ do is to "re-match" the stat information of a file 995 * with the cache, so that you can refresh the cache for a 996 * file that hasn't been changed but where the stat entry is 997 * out of date. 998 * 999 * For example, you'd want to do this after doing a "git-read-tree",1000 * to link up the stat cache details with the proper files.1001 */1002static struct cache_entry *refresh_cache_ent(struct index_state *istate,1003struct cache_entry *ce,1004unsigned int options,int*err)1005{1006struct stat st;1007struct cache_entry *updated;1008int changed, size;1009int ignore_valid = options & CE_MATCH_IGNORE_VALID;1010int ignore_skip_worktree = options & CE_MATCH_IGNORE_SKIP_WORKTREE;10111012if(ce_uptodate(ce))1013return ce;10141015/*1016 * CE_VALID or CE_SKIP_WORKTREE means the user promised us1017 * that the change to the work tree does not matter and told1018 * us not to worry.1019 */1020if(!ignore_skip_worktree &&ce_skip_worktree(ce)) {1021ce_mark_uptodate(ce);1022return ce;1023}1024if(!ignore_valid && (ce->ce_flags & CE_VALID)) {1025ce_mark_uptodate(ce);1026return ce;1027}10281029if(lstat(ce->name, &st) <0) {1030if(err)1031*err = errno;1032return NULL;1033}10341035 changed =ie_match_stat(istate, ce, &st, options);1036if(!changed) {1037/*1038 * The path is unchanged. If we were told to ignore1039 * valid bit, then we did the actual stat check and1040 * found that the entry is unmodified. If the entry1041 * is not marked VALID, this is the place to mark it1042 * valid again, under "assume unchanged" mode.1043 */1044if(ignore_valid && assume_unchanged &&1045!(ce->ce_flags & CE_VALID))1046;/* mark this one VALID again */1047else{1048/*1049 * We do not mark the index itself "modified"1050 * because CE_UPTODATE flag is in-core only;1051 * we are not going to write this change out.1052 */1053if(!S_ISGITLINK(ce->ce_mode))1054ce_mark_uptodate(ce);1055return ce;1056}1057}10581059if(ie_modified(istate, ce, &st, options)) {1060if(err)1061*err = EINVAL;1062return NULL;1063}10641065 size =ce_size(ce);1066 updated =xmalloc(size);1067memcpy(updated, ce, size);1068fill_stat_cache_info(updated, &st);1069/*1070 * If ignore_valid is not set, we should leave CE_VALID bit1071 * alone. Otherwise, paths marked with --no-assume-unchanged1072 * (i.e. things to be edited) will reacquire CE_VALID bit1073 * automatically, which is not really what we want.1074 */1075if(!ignore_valid && assume_unchanged &&1076!(ce->ce_flags & CE_VALID))1077 updated->ce_flags &= ~CE_VALID;10781079return updated;1080}10811082static voidshow_file(const char* fmt,const char* name,int in_porcelain,1083int* first,const char*header_msg)1084{1085if(in_porcelain && *first && header_msg) {1086printf("%s\n", header_msg);1087*first =0;1088}1089printf(fmt, name);1090}10911092intrefresh_index(struct index_state *istate,unsigned int flags,const char**pathspec,1093char*seen,const char*header_msg)1094{1095int i;1096int has_errors =0;1097int really = (flags & REFRESH_REALLY) !=0;1098int allow_unmerged = (flags & REFRESH_UNMERGED) !=0;1099int quiet = (flags & REFRESH_QUIET) !=0;1100int not_new = (flags & REFRESH_IGNORE_MISSING) !=0;1101int ignore_submodules = (flags & REFRESH_IGNORE_SUBMODULES) !=0;1102int first =1;1103int in_porcelain = (flags & REFRESH_IN_PORCELAIN);1104unsigned int options = really ? CE_MATCH_IGNORE_VALID :0;1105const char*needs_update_fmt;1106const char*needs_merge_fmt;11071108 needs_update_fmt = (in_porcelain ?"M\t%s\n":"%s: needs update\n");1109 needs_merge_fmt = (in_porcelain ?"U\t%s\n":"%s: needs merge\n");1110for(i =0; i < istate->cache_nr; i++) {1111struct cache_entry *ce, *new;1112int cache_errno =0;11131114 ce = istate->cache[i];1115if(ignore_submodules &&S_ISGITLINK(ce->ce_mode))1116continue;11171118if(ce_stage(ce)) {1119while((i < istate->cache_nr) &&1120!strcmp(istate->cache[i]->name, ce->name))1121 i++;1122 i--;1123if(allow_unmerged)1124continue;1125show_file(needs_merge_fmt, ce->name, in_porcelain, &first, header_msg);1126 has_errors =1;1127continue;1128}11291130if(pathspec && !match_pathspec(pathspec, ce->name,strlen(ce->name),0, seen))1131continue;11321133new=refresh_cache_ent(istate, ce, options, &cache_errno);1134if(new== ce)1135continue;1136if(!new) {1137if(not_new && cache_errno == ENOENT)1138continue;1139if(really && cache_errno == EINVAL) {1140/* If we are doing --really-refresh that1141 * means the index is not valid anymore.1142 */1143 ce->ce_flags &= ~CE_VALID;1144 istate->cache_changed =1;1145}1146if(quiet)1147continue;1148show_file(needs_update_fmt, ce->name, in_porcelain, &first, header_msg);1149 has_errors =1;1150continue;1151}11521153replace_index_entry(istate, i,new);1154}1155return has_errors;1156}11571158static struct cache_entry *refresh_cache_entry(struct cache_entry *ce,int really)1159{1160returnrefresh_cache_ent(&the_index, ce, really, NULL);1161}11621163static intverify_hdr(struct cache_header *hdr,unsigned long size)1164{1165 git_SHA_CTX c;1166unsigned char sha1[20];11671168if(hdr->hdr_signature !=htonl(CACHE_SIGNATURE))1169returnerror("bad signature");1170if(hdr->hdr_version !=htonl(2) && hdr->hdr_version !=htonl(3))1171returnerror("bad index version");1172git_SHA1_Init(&c);1173git_SHA1_Update(&c, hdr, size -20);1174git_SHA1_Final(sha1, &c);1175if(hashcmp(sha1, (unsigned char*)hdr + size -20))1176returnerror("bad index file sha1 signature");1177return0;1178}11791180static intread_index_extension(struct index_state *istate,1181const char*ext,void*data,unsigned long sz)1182{1183switch(CACHE_EXT(ext)) {1184case CACHE_EXT_TREE:1185 istate->cache_tree =cache_tree_read(data, sz);1186break;1187case CACHE_EXT_RESOLVE_UNDO:1188 istate->resolve_undo =resolve_undo_read(data, sz);1189break;1190default:1191if(*ext <'A'||'Z'< *ext)1192returnerror("index uses %.4s extension, which we do not understand",1193 ext);1194fprintf(stderr,"ignoring %.4s extension\n", ext);1195break;1196}1197return0;1198}11991200intread_index(struct index_state *istate)1201{1202returnread_index_from(istate,get_index_file());1203}12041205static voidconvert_from_disk(struct ondisk_cache_entry *ondisk,struct cache_entry *ce)1206{1207size_t len;1208const char*name;12091210 ce->ce_ctime.sec =ntohl(ondisk->ctime.sec);1211 ce->ce_mtime.sec =ntohl(ondisk->mtime.sec);1212 ce->ce_ctime.nsec =ntohl(ondisk->ctime.nsec);1213 ce->ce_mtime.nsec =ntohl(ondisk->mtime.nsec);1214 ce->ce_dev =ntohl(ondisk->dev);1215 ce->ce_ino =ntohl(ondisk->ino);1216 ce->ce_mode =ntohl(ondisk->mode);1217 ce->ce_uid =ntohl(ondisk->uid);1218 ce->ce_gid =ntohl(ondisk->gid);1219 ce->ce_size =ntohl(ondisk->size);1220/* On-disk flags are just 16 bits */1221 ce->ce_flags =ntohs(ondisk->flags);12221223hashcpy(ce->sha1, ondisk->sha1);12241225 len = ce->ce_flags & CE_NAMEMASK;12261227if(ce->ce_flags & CE_EXTENDED) {1228struct ondisk_cache_entry_extended *ondisk2;1229int extended_flags;1230 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;1231 extended_flags =ntohs(ondisk2->flags2) <<16;1232/* We do not yet understand any bit out of CE_EXTENDED_FLAGS */1233if(extended_flags & ~CE_EXTENDED_FLAGS)1234die("Unknown index entry format%08x", extended_flags);1235 ce->ce_flags |= extended_flags;1236 name = ondisk2->name;1237}1238else1239 name = ondisk->name;12401241if(len == CE_NAMEMASK)1242 len =strlen(name);1243/*1244 * NEEDSWORK: If the original index is crafted, this copy could1245 * go unchecked.1246 */1247memcpy(ce->name, name, len +1);1248}12491250staticinlinesize_testimate_cache_size(size_t ondisk_size,unsigned int entries)1251{1252size_t fix_size_mem =offsetof(struct cache_entry, name);1253size_t fix_size_dsk =offsetof(struct ondisk_cache_entry, name);1254long per_entry = (fix_size_mem - fix_size_dsk +7) & ~7;12551256/*1257 * Alignment can cause differences. This should be "alignof", but1258 * since that's a gcc'ism, just use the size of a pointer.1259 */1260 per_entry +=sizeof(void*);1261return ondisk_size + entries*per_entry;1262}12631264/* remember to discard_cache() before reading a different cache! */1265intread_index_from(struct index_state *istate,const char*path)1266{1267int fd, i;1268struct stat st;1269unsigned long src_offset, dst_offset;1270struct cache_header *hdr;1271void*mmap;1272size_t mmap_size;12731274 errno = EBUSY;1275if(istate->initialized)1276return istate->cache_nr;12771278 errno = ENOENT;1279 istate->timestamp.sec =0;1280 istate->timestamp.nsec =0;1281 fd =open(path, O_RDONLY);1282if(fd <0) {1283if(errno == ENOENT)1284return0;1285die_errno("index file open failed");1286}12871288if(fstat(fd, &st))1289die_errno("cannot stat the open index");12901291 errno = EINVAL;1292 mmap_size =xsize_t(st.st_size);1293if(mmap_size <sizeof(struct cache_header) +20)1294die("index file smaller than expected");12951296 mmap =xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd,0);1297close(fd);1298if(mmap == MAP_FAILED)1299die_errno("unable to map index file");13001301 hdr = mmap;1302if(verify_hdr(hdr, mmap_size) <0)1303goto unmap;13041305 istate->cache_nr =ntohl(hdr->hdr_entries);1306 istate->cache_alloc =alloc_nr(istate->cache_nr);1307 istate->cache =xcalloc(istate->cache_alloc,sizeof(struct cache_entry *));13081309/*1310 * The disk format is actually larger than the in-memory format,1311 * due to space for nsec etc, so even though the in-memory one1312 * has room for a few more flags, we can allocate using the same1313 * index size1314 */1315 istate->alloc =xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));1316 istate->initialized =1;13171318 src_offset =sizeof(*hdr);1319 dst_offset =0;1320for(i =0; i < istate->cache_nr; i++) {1321struct ondisk_cache_entry *disk_ce;1322struct cache_entry *ce;13231324 disk_ce = (struct ondisk_cache_entry *)((char*)mmap + src_offset);1325 ce = (struct cache_entry *)((char*)istate->alloc + dst_offset);1326convert_from_disk(disk_ce, ce);1327set_index_entry(istate, i, ce);13281329 src_offset +=ondisk_ce_size(ce);1330 dst_offset +=ce_size(ce);1331}1332 istate->timestamp.sec = st.st_mtime;1333 istate->timestamp.nsec =ST_MTIME_NSEC(st);13341335while(src_offset <= mmap_size -20-8) {1336/* After an array of active_nr index entries,1337 * there can be arbitrary number of extended1338 * sections, each of which is prefixed with1339 * extension name (4-byte) and section length1340 * in 4-byte network byte order.1341 */1342uint32_t extsize;1343memcpy(&extsize, (char*)mmap + src_offset +4,4);1344 extsize =ntohl(extsize);1345if(read_index_extension(istate,1346(const char*) mmap + src_offset,1347(char*) mmap + src_offset +8,1348 extsize) <0)1349goto unmap;1350 src_offset +=8;1351 src_offset += extsize;1352}1353munmap(mmap, mmap_size);1354return istate->cache_nr;13551356unmap:1357munmap(mmap, mmap_size);1358 errno = EINVAL;1359die("index file corrupt");1360}13611362intis_index_unborn(struct index_state *istate)1363{1364return(!istate->cache_nr && !istate->alloc && !istate->timestamp.sec);1365}13661367intdiscard_index(struct index_state *istate)1368{1369resolve_undo_clear_index(istate);1370 istate->cache_nr =0;1371 istate->cache_changed =0;1372 istate->timestamp.sec =0;1373 istate->timestamp.nsec =0;1374 istate->name_hash_initialized =0;1375free_hash(&istate->name_hash);1376cache_tree_free(&(istate->cache_tree));1377free(istate->alloc);1378 istate->alloc = NULL;1379 istate->initialized =0;13801381/* no need to throw away allocated active_cache */1382return0;1383}13841385intunmerged_index(const struct index_state *istate)1386{1387int i;1388for(i =0; i < istate->cache_nr; i++) {1389if(ce_stage(istate->cache[i]))1390return1;1391}1392return0;1393}13941395#define WRITE_BUFFER_SIZE 81921396static unsigned char write_buffer[WRITE_BUFFER_SIZE];1397static unsigned long write_buffer_len;13981399static intce_write_flush(git_SHA_CTX *context,int fd)1400{1401unsigned int buffered = write_buffer_len;1402if(buffered) {1403git_SHA1_Update(context, write_buffer, buffered);1404if(write_in_full(fd, write_buffer, buffered) != buffered)1405return-1;1406 write_buffer_len =0;1407}1408return0;1409}14101411static intce_write(git_SHA_CTX *context,int fd,void*data,unsigned int len)1412{1413while(len) {1414unsigned int buffered = write_buffer_len;1415unsigned int partial = WRITE_BUFFER_SIZE - buffered;1416if(partial > len)1417 partial = len;1418memcpy(write_buffer + buffered, data, partial);1419 buffered += partial;1420if(buffered == WRITE_BUFFER_SIZE) {1421 write_buffer_len = buffered;1422if(ce_write_flush(context, fd))1423return-1;1424 buffered =0;1425}1426 write_buffer_len = buffered;1427 len -= partial;1428 data = (char*) data + partial;1429}1430return0;1431}14321433static intwrite_index_ext_header(git_SHA_CTX *context,int fd,1434unsigned int ext,unsigned int sz)1435{1436 ext =htonl(ext);1437 sz =htonl(sz);1438return((ce_write(context, fd, &ext,4) <0) ||1439(ce_write(context, fd, &sz,4) <0)) ? -1:0;1440}14411442static intce_flush(git_SHA_CTX *context,int fd)1443{1444unsigned int left = write_buffer_len;14451446if(left) {1447 write_buffer_len =0;1448git_SHA1_Update(context, write_buffer, left);1449}14501451/* Flush first if not enough space for SHA1 signature */1452if(left +20> WRITE_BUFFER_SIZE) {1453if(write_in_full(fd, write_buffer, left) != left)1454return-1;1455 left =0;1456}14571458/* Append the SHA1 signature at the end */1459git_SHA1_Final(write_buffer + left, context);1460 left +=20;1461return(write_in_full(fd, write_buffer, left) != left) ? -1:0;1462}14631464static voidce_smudge_racily_clean_entry(struct cache_entry *ce)1465{1466/*1467 * The only thing we care about in this function is to smudge the1468 * falsely clean entry due to touch-update-touch race, so we leave1469 * everything else as they are. We are called for entries whose1470 * ce_mtime match the index file mtime.1471 *1472 * Note that this actually does not do much for gitlinks, for1473 * which ce_match_stat_basic() always goes to the actual1474 * contents. The caller checks with is_racy_timestamp() which1475 * always says "no" for gitlinks, so we are not called for them ;-)1476 */1477struct stat st;14781479if(lstat(ce->name, &st) <0)1480return;1481if(ce_match_stat_basic(ce, &st))1482return;1483if(ce_modified_check_fs(ce, &st)) {1484/* This is "racily clean"; smudge it. Note that this1485 * is a tricky code. At first glance, it may appear1486 * that it can break with this sequence:1487 *1488 * $ echo xyzzy >frotz1489 * $ git-update-index --add frotz1490 * $ : >frotz1491 * $ sleep 31492 * $ echo filfre >nitfol1493 * $ git-update-index --add nitfol1494 *1495 * but it does not. When the second update-index runs,1496 * it notices that the entry "frotz" has the same timestamp1497 * as index, and if we were to smudge it by resetting its1498 * size to zero here, then the object name recorded1499 * in index is the 6-byte file but the cached stat information1500 * becomes zero --- which would then match what we would1501 * obtain from the filesystem next time we stat("frotz").1502 *1503 * However, the second update-index, before calling1504 * this function, notices that the cached size is 61505 * bytes and what is on the filesystem is an empty1506 * file, and never calls us, so the cached size information1507 * for "frotz" stays 6 which does not match the filesystem.1508 */1509 ce->ce_size =0;1510}1511}15121513static intce_write_entry(git_SHA_CTX *c,int fd,struct cache_entry *ce)1514{1515int size =ondisk_ce_size(ce);1516struct ondisk_cache_entry *ondisk =xcalloc(1, size);1517char*name;1518int result;15191520 ondisk->ctime.sec =htonl(ce->ce_ctime.sec);1521 ondisk->mtime.sec =htonl(ce->ce_mtime.sec);1522 ondisk->ctime.nsec =htonl(ce->ce_ctime.nsec);1523 ondisk->mtime.nsec =htonl(ce->ce_mtime.nsec);1524 ondisk->dev =htonl(ce->ce_dev);1525 ondisk->ino =htonl(ce->ce_ino);1526 ondisk->mode =htonl(ce->ce_mode);1527 ondisk->uid =htonl(ce->ce_uid);1528 ondisk->gid =htonl(ce->ce_gid);1529 ondisk->size =htonl(ce->ce_size);1530hashcpy(ondisk->sha1, ce->sha1);1531 ondisk->flags =htons(ce->ce_flags);1532if(ce->ce_flags & CE_EXTENDED) {1533struct ondisk_cache_entry_extended *ondisk2;1534 ondisk2 = (struct ondisk_cache_entry_extended *)ondisk;1535 ondisk2->flags2 =htons((ce->ce_flags & CE_EXTENDED_FLAGS) >>16);1536 name = ondisk2->name;1537}1538else1539 name = ondisk->name;1540memcpy(name, ce->name,ce_namelen(ce));15411542 result =ce_write(c, fd, ondisk, size);1543free(ondisk);1544return result;1545}15461547static inthas_racy_timestamp(struct index_state *istate)1548{1549int entries = istate->cache_nr;1550int i;15511552for(i =0; i < entries; i++) {1553struct cache_entry *ce = istate->cache[i];1554if(is_racy_timestamp(istate, ce))1555return1;1556}1557return0;1558}15591560/*1561 * Opportunisticly update the index but do not complain if we can't1562 */1563voidupdate_index_if_able(struct index_state *istate,struct lock_file *lockfile)1564{1565if((istate->cache_changed ||has_racy_timestamp(istate)) &&1566!write_index(istate, lockfile->fd))1567commit_locked_index(lockfile);1568else1569rollback_lock_file(lockfile);1570}15711572intwrite_index(struct index_state *istate,int newfd)1573{1574 git_SHA_CTX c;1575struct cache_header hdr;1576int i, err, removed, extended;1577struct cache_entry **cache = istate->cache;1578int entries = istate->cache_nr;1579struct stat st;15801581for(i = removed = extended =0; i < entries; i++) {1582if(cache[i]->ce_flags & CE_REMOVE)1583 removed++;15841585/* reduce extended entries if possible */1586 cache[i]->ce_flags &= ~CE_EXTENDED;1587if(cache[i]->ce_flags & CE_EXTENDED_FLAGS) {1588 extended++;1589 cache[i]->ce_flags |= CE_EXTENDED;1590}1591}15921593 hdr.hdr_signature =htonl(CACHE_SIGNATURE);1594/* for extended format, increase version so older git won't try to read it */1595 hdr.hdr_version =htonl(extended ?3:2);1596 hdr.hdr_entries =htonl(entries - removed);15971598git_SHA1_Init(&c);1599if(ce_write(&c, newfd, &hdr,sizeof(hdr)) <0)1600return-1;16011602for(i =0; i < entries; i++) {1603struct cache_entry *ce = cache[i];1604if(ce->ce_flags & CE_REMOVE)1605continue;1606if(!ce_uptodate(ce) &&is_racy_timestamp(istate, ce))1607ce_smudge_racily_clean_entry(ce);1608if(ce_write_entry(&c, newfd, ce) <0)1609return-1;1610}16111612/* Write extension data here */1613if(istate->cache_tree) {1614struct strbuf sb = STRBUF_INIT;16151616cache_tree_write(&sb, istate->cache_tree);1617 err =write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) <01618||ce_write(&c, newfd, sb.buf, sb.len) <0;1619strbuf_release(&sb);1620if(err)1621return-1;1622}1623if(istate->resolve_undo) {1624struct strbuf sb = STRBUF_INIT;16251626resolve_undo_write(&sb, istate->resolve_undo);1627 err =write_index_ext_header(&c, newfd, CACHE_EXT_RESOLVE_UNDO,1628 sb.len) <01629||ce_write(&c, newfd, sb.buf, sb.len) <0;1630strbuf_release(&sb);1631if(err)1632return-1;1633}16341635if(ce_flush(&c, newfd) ||fstat(newfd, &st))1636return-1;1637 istate->timestamp.sec = (unsigned int)st.st_mtime;1638 istate->timestamp.nsec =ST_MTIME_NSEC(st);1639return0;1640}16411642/*1643 * Read the index file that is potentially unmerged into given1644 * index_state, dropping any unmerged entries. Returns true if1645 * the index is unmerged. Callers who want to refuse to work1646 * from an unmerged state can call this and check its return value,1647 * instead of calling read_cache().1648 */1649intread_index_unmerged(struct index_state *istate)1650{1651int i;1652int unmerged =0;16531654read_index(istate);1655for(i =0; i < istate->cache_nr; i++) {1656struct cache_entry *ce = istate->cache[i];1657struct cache_entry *new_ce;1658int size, len;16591660if(!ce_stage(ce))1661continue;1662 unmerged =1;1663 len =strlen(ce->name);1664 size =cache_entry_size(len);1665 new_ce =xcalloc(1, size);1666memcpy(new_ce->name, ce->name, len);1667 new_ce->ce_flags =create_ce_flags(len,0) | CE_CONFLICTED;1668 new_ce->ce_mode = ce->ce_mode;1669if(add_index_entry(istate, new_ce,0))1670returnerror("%s: cannot drop to stage #0",1671 ce->name);1672 i =index_name_pos(istate, new_ce->name, len);1673}1674return unmerged;1675}16761677/*1678 * Returns 1 if the path is an "other" path with respect to1679 * the index; that is, the path is not mentioned in the index at all,1680 * either as a file, a directory with some files in the index,1681 * or as an unmerged entry.1682 *1683 * We helpfully remove a trailing "/" from directories so that1684 * the output of read_directory can be used as-is.1685 */1686intindex_name_is_other(const struct index_state *istate,const char*name,1687int namelen)1688{1689int pos;1690if(namelen && name[namelen -1] =='/')1691 namelen--;1692 pos =index_name_pos(istate, name, namelen);1693if(0<= pos)1694return0;/* exact match */1695 pos = -pos -1;1696if(pos < istate->cache_nr) {1697struct cache_entry *ce = istate->cache[pos];1698if(ce_namelen(ce) == namelen &&1699!memcmp(ce->name, name, namelen))1700return0;/* Yup, this one exists unmerged */1701}1702return1;1703}