1#include"cache.h" 2#include"lockfile.h" 3#include"string-list.h" 4#include"rerere.h" 5#include"xdiff-interface.h" 6#include"dir.h" 7#include"resolve-undo.h" 8#include"ll-merge.h" 9#include"attr.h" 10#include"pathspec.h" 11 12#define RESOLVED 0 13#define PUNTED 1 14#define THREE_STAGED 2 15void*RERERE_RESOLVED = &RERERE_RESOLVED; 16 17/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */ 18static int rerere_enabled = -1; 19 20/* automatically update cleanly resolved paths to the index */ 21static int rerere_autoupdate; 22 23static voidfree_rerere_id(struct string_list_item *item) 24{ 25free(item->util); 26} 27 28static const char*rerere_id_hex(const struct rerere_id *id) 29{ 30return id->hex; 31} 32 33const char*rerere_path(const struct rerere_id *id,const char*file) 34{ 35if(!file) 36returngit_path("rr-cache/%s",rerere_id_hex(id)); 37 38returngit_path("rr-cache/%s/%s",rerere_id_hex(id), file); 39} 40 41static inthas_rerere_resolution(const struct rerere_id *id) 42{ 43struct stat st; 44 45return!stat(rerere_path(id,"postimage"), &st); 46} 47 48static struct rerere_id *new_rerere_id_hex(char*hex) 49{ 50struct rerere_id *id =xmalloc(sizeof(*id)); 51xsnprintf(id->hex,sizeof(id->hex),"%s", hex); 52return id; 53} 54 55static struct rerere_id *new_rerere_id(unsigned char*sha1) 56{ 57returnnew_rerere_id_hex(sha1_to_hex(sha1)); 58} 59 60/* 61 * $GIT_DIR/MERGE_RR file is a collection of records, each of which is 62 * "conflict ID", a HT and pathname, terminated with a NUL, and is 63 * used to keep track of the set of paths that "rerere" may need to 64 * work on (i.e. what is left by the previous invocation of "git 65 * rerere" during the current conflict resolution session). 66 */ 67static voidread_rr(struct string_list *rr) 68{ 69struct strbuf buf = STRBUF_INIT; 70FILE*in =fopen(git_path_merge_rr(),"r"); 71 72if(!in) 73return; 74while(!strbuf_getwholeline(&buf, in,'\0')) { 75char*path; 76unsigned char sha1[20]; 77struct rerere_id *id; 78 79/* There has to be the hash, tab, path and then NUL */ 80if(buf.len <42||get_sha1_hex(buf.buf, sha1)) 81die("corrupt MERGE_RR"); 82 83if(buf.buf[40] !='\t') 84die("corrupt MERGE_RR"); 85 buf.buf[40] ='\0'; 86 path = buf.buf +41; 87 id =new_rerere_id_hex(buf.buf); 88string_list_insert(rr, path)->util = id; 89} 90strbuf_release(&buf); 91fclose(in); 92} 93 94static struct lock_file write_lock; 95 96static intwrite_rr(struct string_list *rr,int out_fd) 97{ 98int i; 99for(i =0; i < rr->nr; i++) { 100struct strbuf buf = STRBUF_INIT; 101struct rerere_id *id; 102 103assert(rr->items[i].util != RERERE_RESOLVED); 104 105 id = rr->items[i].util; 106if(!id) 107continue; 108strbuf_addf(&buf,"%s\t%s%c", 109rerere_id_hex(id), 110 rr->items[i].string,0); 111if(write_in_full(out_fd, buf.buf, buf.len) != buf.len) 112die("unable to write rerere record"); 113 114strbuf_release(&buf); 115} 116if(commit_lock_file(&write_lock) !=0) 117die("unable to write rerere record"); 118return0; 119} 120 121/* 122 * "rerere" interacts with conflicted file contents using this I/O 123 * abstraction. It reads a conflicted contents from one place via 124 * "getline()" method, and optionally can write it out after 125 * normalizing the conflicted hunks to the "output". Subclasses of 126 * rerere_io embed this structure at the beginning of their own 127 * rerere_io object. 128 */ 129struct rerere_io { 130int(*getline)(struct strbuf *,struct rerere_io *); 131FILE*output; 132int wrerror; 133/* some more stuff */ 134}; 135 136static voidferr_write(const void*p,size_t count,FILE*fp,int*err) 137{ 138if(!count || *err) 139return; 140if(fwrite(p, count,1, fp) !=1) 141*err = errno; 142} 143 144staticinlinevoidferr_puts(const char*s,FILE*fp,int*err) 145{ 146ferr_write(s,strlen(s), fp, err); 147} 148 149static voidrerere_io_putstr(const char*str,struct rerere_io *io) 150{ 151if(io->output) 152ferr_puts(str, io->output, &io->wrerror); 153} 154 155/* 156 * Write a conflict marker to io->output (if defined). 157 */ 158static voidrerere_io_putconflict(int ch,int size,struct rerere_io *io) 159{ 160char buf[64]; 161 162while(size) { 163if(size <=sizeof(buf) -2) { 164memset(buf, ch, size); 165 buf[size] ='\n'; 166 buf[size +1] ='\0'; 167 size =0; 168}else{ 169int sz =sizeof(buf) -1; 170 171/* 172 * Make sure we will not write everything out 173 * in this round by leaving at least 1 byte 174 * for the next round, giving the next round 175 * a chance to add the terminating LF. Yuck. 176 */ 177if(size <= sz) 178 sz -= (sz - size) +1; 179memset(buf, ch, sz); 180 buf[sz] ='\0'; 181 size -= sz; 182} 183rerere_io_putstr(buf, io); 184} 185} 186 187static voidrerere_io_putmem(const char*mem,size_t sz,struct rerere_io *io) 188{ 189if(io->output) 190ferr_write(mem, sz, io->output, &io->wrerror); 191} 192 193/* 194 * Subclass of rerere_io that reads from an on-disk file 195 */ 196struct rerere_io_file { 197struct rerere_io io; 198FILE*input; 199}; 200 201/* 202 * ... and its getline() method implementation 203 */ 204static intrerere_file_getline(struct strbuf *sb,struct rerere_io *io_) 205{ 206struct rerere_io_file *io = (struct rerere_io_file *)io_; 207returnstrbuf_getwholeline(sb, io->input,'\n'); 208} 209 210/* 211 * Require the exact number of conflict marker letters, no more, no 212 * less, followed by SP or any whitespace 213 * (including LF). 214 */ 215static intis_cmarker(char*buf,int marker_char,int marker_size) 216{ 217int want_sp; 218 219/* 220 * The beginning of our version and the end of their version 221 * always are labeled like "<<<<< ours" or ">>>>> theirs", 222 * hence we set want_sp for them. Note that the version from 223 * the common ancestor in diff3-style output is not always 224 * labelled (e.g. "||||| common" is often seen but "|||||" 225 * alone is also valid), so we do not set want_sp. 226 */ 227 want_sp = (marker_char =='<') || (marker_char =='>'); 228 229while(marker_size--) 230if(*buf++ != marker_char) 231return0; 232if(want_sp && *buf !=' ') 233return0; 234returnisspace(*buf); 235} 236 237/* 238 * Read contents a file with conflicts, normalize the conflicts 239 * by (1) discarding the common ancestor version in diff3-style, 240 * (2) reordering our side and their side so that whichever sorts 241 * alphabetically earlier comes before the other one, while 242 * computing the "conflict ID", which is just an SHA-1 hash of 243 * one side of the conflict, NUL, the other side of the conflict, 244 * and NUL concatenated together. 245 * 246 * Return the number of conflict hunks found. 247 * 248 * NEEDSWORK: the logic and theory of operation behind this conflict 249 * normalization may deserve to be documented somewhere, perhaps in 250 * Documentation/technical/rerere.txt. 251 */ 252static inthandle_path(unsigned char*sha1,struct rerere_io *io,int marker_size) 253{ 254 git_SHA_CTX ctx; 255int hunk_no =0; 256enum{ 257 RR_CONTEXT =0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL 258} hunk = RR_CONTEXT; 259struct strbuf one = STRBUF_INIT, two = STRBUF_INIT; 260struct strbuf buf = STRBUF_INIT; 261 262if(sha1) 263git_SHA1_Init(&ctx); 264 265while(!io->getline(&buf, io)) { 266if(is_cmarker(buf.buf,'<', marker_size)) { 267if(hunk != RR_CONTEXT) 268goto bad; 269 hunk = RR_SIDE_1; 270}else if(is_cmarker(buf.buf,'|', marker_size)) { 271if(hunk != RR_SIDE_1) 272goto bad; 273 hunk = RR_ORIGINAL; 274}else if(is_cmarker(buf.buf,'=', marker_size)) { 275if(hunk != RR_SIDE_1 && hunk != RR_ORIGINAL) 276goto bad; 277 hunk = RR_SIDE_2; 278}else if(is_cmarker(buf.buf,'>', marker_size)) { 279if(hunk != RR_SIDE_2) 280goto bad; 281if(strbuf_cmp(&one, &two) >0) 282strbuf_swap(&one, &two); 283 hunk_no++; 284 hunk = RR_CONTEXT; 285rerere_io_putconflict('<', marker_size, io); 286rerere_io_putmem(one.buf, one.len, io); 287rerere_io_putconflict('=', marker_size, io); 288rerere_io_putmem(two.buf, two.len, io); 289rerere_io_putconflict('>', marker_size, io); 290if(sha1) { 291git_SHA1_Update(&ctx, one.buf ? one.buf :"", 292 one.len +1); 293git_SHA1_Update(&ctx, two.buf ? two.buf :"", 294 two.len +1); 295} 296strbuf_reset(&one); 297strbuf_reset(&two); 298}else if(hunk == RR_SIDE_1) 299strbuf_addbuf(&one, &buf); 300else if(hunk == RR_ORIGINAL) 301;/* discard */ 302else if(hunk == RR_SIDE_2) 303strbuf_addbuf(&two, &buf); 304else 305rerere_io_putstr(buf.buf, io); 306continue; 307 bad: 308 hunk =99;/* force error exit */ 309break; 310} 311strbuf_release(&one); 312strbuf_release(&two); 313strbuf_release(&buf); 314 315if(sha1) 316git_SHA1_Final(sha1, &ctx); 317if(hunk != RR_CONTEXT) 318return-1; 319return hunk_no; 320} 321 322/* 323 * Scan the path for conflicts, do the "handle_path()" thing above, and 324 * return the number of conflict hunks found. 325 */ 326static inthandle_file(const char*path,unsigned char*sha1,const char*output) 327{ 328int hunk_no =0; 329struct rerere_io_file io; 330int marker_size =ll_merge_marker_size(path); 331 332memset(&io,0,sizeof(io)); 333 io.io.getline = rerere_file_getline; 334 io.input =fopen(path,"r"); 335 io.io.wrerror =0; 336if(!io.input) 337returnerror("Could not open%s", path); 338 339if(output) { 340 io.io.output =fopen(output,"w"); 341if(!io.io.output) { 342fclose(io.input); 343returnerror("Could not write%s", output); 344} 345} 346 347 hunk_no =handle_path(sha1, (struct rerere_io *)&io, marker_size); 348 349fclose(io.input); 350if(io.io.wrerror) 351error("There were errors while writing%s(%s)", 352 path,strerror(io.io.wrerror)); 353if(io.io.output &&fclose(io.io.output)) 354 io.io.wrerror =error_errno("Failed to flush%s", path); 355 356if(hunk_no <0) { 357if(output) 358unlink_or_warn(output); 359returnerror("Could not parse conflict hunks in%s", path); 360} 361if(io.io.wrerror) 362return-1; 363return hunk_no; 364} 365 366/* 367 * Subclass of rerere_io that reads from an in-core buffer that is a 368 * strbuf 369 */ 370struct rerere_io_mem { 371struct rerere_io io; 372struct strbuf input; 373}; 374 375/* 376 * ... and its getline() method implementation 377 */ 378static intrerere_mem_getline(struct strbuf *sb,struct rerere_io *io_) 379{ 380struct rerere_io_mem *io = (struct rerere_io_mem *)io_; 381char*ep; 382size_t len; 383 384strbuf_release(sb); 385if(!io->input.len) 386return-1; 387 ep =memchr(io->input.buf,'\n', io->input.len); 388if(!ep) 389 ep = io->input.buf + io->input.len; 390else if(*ep =='\n') 391 ep++; 392 len = ep - io->input.buf; 393strbuf_add(sb, io->input.buf, len); 394strbuf_remove(&io->input,0, len); 395return0; 396} 397 398static inthandle_cache(const char*path,unsigned char*sha1,const char*output) 399{ 400 mmfile_t mmfile[3] = {{NULL}}; 401 mmbuffer_t result = {NULL,0}; 402const struct cache_entry *ce; 403int pos, len, i, hunk_no; 404struct rerere_io_mem io; 405int marker_size =ll_merge_marker_size(path); 406 407/* 408 * Reproduce the conflicted merge in-core 409 */ 410 len =strlen(path); 411 pos =cache_name_pos(path, len); 412if(0<= pos) 413return-1; 414 pos = -pos -1; 415 416while(pos < active_nr) { 417enum object_type type; 418unsigned long size; 419 420 ce = active_cache[pos++]; 421if(ce_namelen(ce) != len ||memcmp(ce->name, path, len)) 422break; 423 i =ce_stage(ce) -1; 424if(!mmfile[i].ptr) { 425 mmfile[i].ptr =read_sha1_file(ce->sha1, &type, &size); 426 mmfile[i].size = size; 427} 428} 429for(i =0; i <3; i++) 430if(!mmfile[i].ptr && !mmfile[i].size) 431 mmfile[i].ptr =xstrdup(""); 432 433/* 434 * NEEDSWORK: handle conflicts from merges with 435 * merge.renormalize set, too 436 */ 437ll_merge(&result, path, &mmfile[0], NULL, 438&mmfile[1],"ours", 439&mmfile[2],"theirs", NULL); 440for(i =0; i <3; i++) 441free(mmfile[i].ptr); 442 443memset(&io,0,sizeof(io)); 444 io.io.getline = rerere_mem_getline; 445if(output) 446 io.io.output =fopen(output,"w"); 447else 448 io.io.output = NULL; 449strbuf_init(&io.input,0); 450strbuf_attach(&io.input, result.ptr, result.size, result.size); 451 452/* 453 * Grab the conflict ID and optionally write the original 454 * contents with conflict markers out. 455 */ 456 hunk_no =handle_path(sha1, (struct rerere_io *)&io, marker_size); 457strbuf_release(&io.input); 458if(io.io.output) 459fclose(io.io.output); 460return hunk_no; 461} 462 463/* 464 * Look at a cache entry at "i" and see if it is not conflicting, 465 * conflicting and we are willing to handle, or conflicting and 466 * we are unable to handle, and return the determination in *type. 467 * Return the cache index to be looked at next, by skipping the 468 * stages we have already looked at in this invocation of this 469 * function. 470 */ 471static intcheck_one_conflict(int i,int*type) 472{ 473const struct cache_entry *e = active_cache[i]; 474 475if(!ce_stage(e)) { 476*type = RESOLVED; 477return i +1; 478} 479 480*type = PUNTED; 481while(ce_stage(active_cache[i]) ==1) 482 i++; 483 484/* Only handle regular files with both stages #2 and #3 */ 485if(i +1< active_nr) { 486const struct cache_entry *e2 = active_cache[i]; 487const struct cache_entry *e3 = active_cache[i +1]; 488if(ce_stage(e2) ==2&& 489ce_stage(e3) ==3&& 490ce_same_name(e, e3) && 491S_ISREG(e2->ce_mode) && 492S_ISREG(e3->ce_mode)) 493*type = THREE_STAGED; 494} 495 496/* Skip the entries with the same name */ 497while(i < active_nr &&ce_same_name(e, active_cache[i])) 498 i++; 499return i; 500} 501 502/* 503 * Scan the index and find paths that have conflicts that rerere can 504 * handle, i.e. the ones that has both stages #2 and #3. 505 * 506 * NEEDSWORK: we do not record or replay a previous "resolve by 507 * deletion" for a delete-modify conflict, as that is inherently risky 508 * without knowing what modification is being discarded. The only 509 * safe case, i.e. both side doing the deletion and modification that 510 * are identical to the previous round, might want to be handled, 511 * though. 512 */ 513static intfind_conflict(struct string_list *conflict) 514{ 515int i; 516if(read_cache() <0) 517returnerror("Could not read index"); 518 519for(i =0; i < active_nr;) { 520int conflict_type; 521const struct cache_entry *e = active_cache[i]; 522 i =check_one_conflict(i, &conflict_type); 523if(conflict_type == THREE_STAGED) 524string_list_insert(conflict, (const char*)e->name); 525} 526return0; 527} 528 529/* 530 * The merge_rr list is meant to hold outstanding conflicted paths 531 * that rerere could handle. Abuse the list by adding other types of 532 * entries to allow the caller to show "rerere remaining". 533 * 534 * - Conflicted paths that rerere does not handle are added 535 * - Conflicted paths that have been resolved are marked as such 536 * by storing RERERE_RESOLVED to .util field (where conflict ID 537 * is expected to be stored). 538 * 539 * Do *not* write MERGE_RR file out after calling this function. 540 * 541 * NEEDSWORK: we may want to fix the caller that implements "rerere 542 * remaining" to do this without abusing merge_rr. 543 */ 544intrerere_remaining(struct string_list *merge_rr) 545{ 546int i; 547if(setup_rerere(merge_rr, RERERE_READONLY)) 548return0; 549if(read_cache() <0) 550returnerror("Could not read index"); 551 552for(i =0; i < active_nr;) { 553int conflict_type; 554const struct cache_entry *e = active_cache[i]; 555 i =check_one_conflict(i, &conflict_type); 556if(conflict_type == PUNTED) 557string_list_insert(merge_rr, (const char*)e->name); 558else if(conflict_type == RESOLVED) { 559struct string_list_item *it; 560 it =string_list_lookup(merge_rr, (const char*)e->name); 561if(it != NULL) { 562free_rerere_id(it); 563 it->util = RERERE_RESOLVED; 564} 565} 566} 567return0; 568} 569 570/* 571 * Find the conflict identified by "id"; the change between its 572 * "preimage" (i.e. a previous contents with conflict markers) and its 573 * "postimage" (i.e. the corresponding contents with conflicts 574 * resolved) may apply cleanly to the contents stored in "path", i.e. 575 * the conflict this time around. 576 * 577 * Returns 0 for successful replay of recorded resolution, or non-zero 578 * for failure. 579 */ 580static intmerge(const struct rerere_id *id,const char*path) 581{ 582FILE*f; 583int ret; 584 mmfile_t cur = {NULL,0}, base = {NULL,0}, other = {NULL,0}; 585 mmbuffer_t result = {NULL,0}; 586 587/* 588 * Normalize the conflicts in path and write it out to 589 * "thisimage" temporary file. 590 */ 591if(handle_file(path, NULL,rerere_path(id,"thisimage")) <0) { 592 ret =1; 593goto out; 594} 595 596if(read_mmfile(&cur,rerere_path(id,"thisimage")) || 597read_mmfile(&base,rerere_path(id,"preimage")) || 598read_mmfile(&other,rerere_path(id,"postimage"))) { 599 ret =1; 600goto out; 601} 602 603/* 604 * A three-way merge. Note that this honors user-customizable 605 * low-level merge driver settings. 606 */ 607 ret =ll_merge(&result, path, &base, NULL, &cur,"", &other,"", NULL); 608if(ret) 609goto out; 610 611/* 612 * A successful replay of recorded resolution. 613 * Mark that "postimage" was used to help gc. 614 */ 615if(utime(rerere_path(id,"postimage"), NULL) <0) 616warning_errno("failed utime() on%s", 617rerere_path(id,"postimage")); 618 619/* Update "path" with the resolution */ 620 f =fopen(path,"w"); 621if(!f) 622returnerror_errno("Could not open%s", path); 623if(fwrite(result.ptr, result.size,1, f) !=1) 624error_errno("Could not write%s", path); 625if(fclose(f)) 626returnerror_errno("Writing%sfailed", path); 627 628out: 629free(cur.ptr); 630free(base.ptr); 631free(other.ptr); 632free(result.ptr); 633 634return ret; 635} 636 637static struct lock_file index_lock; 638 639static voidupdate_paths(struct string_list *update) 640{ 641int i; 642 643hold_locked_index(&index_lock,1); 644 645for(i =0; i < update->nr; i++) { 646struct string_list_item *item = &update->items[i]; 647if(add_file_to_cache(item->string,0)) 648exit(128); 649fprintf(stderr,"Staged '%s' using previous resolution.\n", 650 item->string); 651} 652 653if(active_cache_changed) { 654if(write_locked_index(&the_index, &index_lock, COMMIT_LOCK)) 655die("Unable to write new index file"); 656}else 657rollback_lock_file(&index_lock); 658} 659 660/* 661 * The path indicated by rr_item may still have conflict for which we 662 * have a recorded resolution, in which case replay it and optionally 663 * update it. Or it may have been resolved by the user and we may 664 * only have the preimage for that conflict, in which case the result 665 * needs to be recorded as a resolution in a postimage file. 666 */ 667static voiddo_rerere_one_path(struct string_list_item *rr_item, 668struct string_list *update) 669{ 670const char*path = rr_item->string; 671const struct rerere_id *id = rr_item->util; 672 673/* Is there a recorded resolution we could attempt to apply? */ 674if(has_rerere_resolution(id)) { 675if(merge(id, path)) 676return;/* failed to replay */ 677 678if(rerere_autoupdate) 679string_list_insert(update, path); 680else 681fprintf(stderr, 682"Resolved '%s' using previous resolution.\n", 683 path); 684}else if(!handle_file(path, NULL, NULL)) { 685/* The user has resolved it. */ 686copy_file(rerere_path(id,"postimage"), path,0666); 687fprintf(stderr,"Recorded resolution for '%s'.\n", path); 688}else{ 689return; 690} 691free_rerere_id(rr_item); 692 rr_item->util = NULL; 693} 694 695static intdo_plain_rerere(struct string_list *rr,int fd) 696{ 697struct string_list conflict = STRING_LIST_INIT_DUP; 698struct string_list update = STRING_LIST_INIT_DUP; 699int i; 700 701find_conflict(&conflict); 702 703/* 704 * MERGE_RR records paths with conflicts immediately after 705 * merge failed. Some of the conflicted paths might have been 706 * hand resolved in the working tree since then, but the 707 * initial run would catch all and register their preimages. 708 */ 709for(i =0; i < conflict.nr; i++) { 710struct rerere_id *id; 711unsigned char sha1[20]; 712const char*path = conflict.items[i].string; 713int ret; 714 715if(string_list_has_string(rr, path)) 716continue; 717 718/* 719 * Ask handle_file() to scan and assign a 720 * conflict ID. No need to write anything out 721 * yet. 722 */ 723 ret =handle_file(path, sha1, NULL); 724if(ret <1) 725continue; 726 727 id =new_rerere_id(sha1); 728string_list_insert(rr, path)->util = id; 729 730/* 731 * If the directory does not exist, create 732 * it. mkdir_in_gitdir() will fail with 733 * EEXIST if there already is one. 734 * 735 * NEEDSWORK: make sure "gc" does not remove 736 * preimage without removing the directory. 737 */ 738if(mkdir_in_gitdir(rerere_path(id, NULL))) 739continue; 740 741/* 742 * We are the first to encounter this 743 * conflict. Ask handle_file() to write the 744 * normalized contents to the "preimage" file. 745 */ 746handle_file(path, NULL,rerere_path(id,"preimage")); 747fprintf(stderr,"Recorded preimage for '%s'\n", path); 748} 749 750for(i =0; i < rr->nr; i++) 751do_rerere_one_path(&rr->items[i], &update); 752 753if(update.nr) 754update_paths(&update); 755 756returnwrite_rr(rr, fd); 757} 758 759static voidgit_rerere_config(void) 760{ 761git_config_get_bool("rerere.enabled", &rerere_enabled); 762git_config_get_bool("rerere.autoupdate", &rerere_autoupdate); 763git_config(git_default_config, NULL); 764} 765 766staticGIT_PATH_FUNC(git_path_rr_cache,"rr-cache") 767 768static intis_rerere_enabled(void) 769{ 770int rr_cache_exists; 771 772if(!rerere_enabled) 773return0; 774 775 rr_cache_exists =is_directory(git_path_rr_cache()); 776if(rerere_enabled <0) 777return rr_cache_exists; 778 779if(!rr_cache_exists &&mkdir_in_gitdir(git_path_rr_cache())) 780die("Could not create directory%s",git_path_rr_cache()); 781return1; 782} 783 784intsetup_rerere(struct string_list *merge_rr,int flags) 785{ 786int fd; 787 788git_rerere_config(); 789if(!is_rerere_enabled()) 790return-1; 791 792if(flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE)) 793 rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE); 794if(flags & RERERE_READONLY) 795 fd =0; 796else 797 fd =hold_lock_file_for_update(&write_lock,git_path_merge_rr(), 798 LOCK_DIE_ON_ERROR); 799read_rr(merge_rr); 800return fd; 801} 802 803/* 804 * The main entry point that is called internally from codepaths that 805 * perform mergy operations, possibly leaving conflicted index entries 806 * and working tree files. 807 */ 808intrerere(int flags) 809{ 810struct string_list merge_rr = STRING_LIST_INIT_DUP; 811int fd; 812 813 fd =setup_rerere(&merge_rr, flags); 814if(fd <0) 815return0; 816returndo_plain_rerere(&merge_rr, fd); 817} 818 819static intrerere_forget_one_path(const char*path,struct string_list *rr) 820{ 821const char*filename; 822struct rerere_id *id; 823unsigned char sha1[20]; 824int ret; 825struct string_list_item *item; 826 827/* 828 * Recreate the original conflict from the stages in the 829 * index and compute the conflict ID 830 */ 831 ret =handle_cache(path, sha1, NULL); 832if(ret <1) 833returnerror("Could not parse conflict hunks in '%s'", path); 834 835/* Nuke the recorded resolution for the conflict */ 836 id =new_rerere_id(sha1); 837 filename =rerere_path(id,"postimage"); 838if(unlink(filename)) 839return(errno == ENOENT 840?error("no remembered resolution for%s", path) 841:error_errno("cannot unlink%s", filename)); 842 843/* 844 * Update the preimage so that the user can resolve the 845 * conflict in the working tree, run us again to record 846 * the postimage. 847 */ 848handle_cache(path, sha1,rerere_path(id,"preimage")); 849fprintf(stderr,"Updated preimage for '%s'\n", path); 850 851/* 852 * And remember that we can record resolution for this 853 * conflict when the user is done. 854 */ 855 item =string_list_insert(rr, path); 856free_rerere_id(item); 857 item->util = id; 858fprintf(stderr,"Forgot resolution for%s\n", path); 859return0; 860} 861 862intrerere_forget(struct pathspec *pathspec) 863{ 864int i, fd; 865struct string_list conflict = STRING_LIST_INIT_DUP; 866struct string_list merge_rr = STRING_LIST_INIT_DUP; 867 868if(read_cache() <0) 869returnerror("Could not read index"); 870 871 fd =setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE); 872if(fd <0) 873return0; 874 875/* 876 * The paths may have been resolved (incorrectly); 877 * recover the original conflicted state and then 878 * find the conflicted paths. 879 */ 880unmerge_cache(pathspec); 881find_conflict(&conflict); 882for(i =0; i < conflict.nr; i++) { 883struct string_list_item *it = &conflict.items[i]; 884if(!match_pathspec(pathspec, it->string, 885strlen(it->string),0, NULL,0)) 886continue; 887rerere_forget_one_path(it->string, &merge_rr); 888} 889returnwrite_rr(&merge_rr, fd); 890} 891 892/* 893 * Garbage collection support 894 */ 895 896/* 897 * Note that this is not reentrant but is used only one-at-a-time 898 * so it does not matter right now. 899 */ 900static struct rerere_id *dirname_to_id(const char*name) 901{ 902static struct rerere_id id; 903xsnprintf(id.hex,sizeof(id.hex),"%s", name); 904return&id; 905} 906 907static time_trerere_created_at(const char*dir_name) 908{ 909struct stat st; 910struct rerere_id *id =dirname_to_id(dir_name); 911 912returnstat(rerere_path(id,"preimage"), &st) ? (time_t)0: st.st_mtime; 913} 914 915static time_trerere_last_used_at(const char*dir_name) 916{ 917struct stat st; 918struct rerere_id *id =dirname_to_id(dir_name); 919 920returnstat(rerere_path(id,"postimage"), &st) ? (time_t)0: st.st_mtime; 921} 922 923/* 924 * Remove the recorded resolution for a given conflict ID 925 */ 926static voidunlink_rr_item(struct rerere_id *id) 927{ 928unlink(rerere_path(id,"thisimage")); 929unlink(rerere_path(id,"preimage")); 930unlink(rerere_path(id,"postimage")); 931/* 932 * NEEDSWORK: what if this rmdir() fails? Wouldn't we then 933 * assume that we already have preimage recorded in 934 * do_plain_rerere()? 935 */ 936rmdir(rerere_path(id, NULL)); 937} 938 939voidrerere_gc(struct string_list *rr) 940{ 941struct string_list to_remove = STRING_LIST_INIT_DUP; 942DIR*dir; 943struct dirent *e; 944int i, cutoff; 945time_t now =time(NULL), then; 946int cutoff_noresolve =15; 947int cutoff_resolve =60; 948 949if(setup_rerere(rr,0) <0) 950return; 951 952git_config_get_int("gc.rerereresolved", &cutoff_resolve); 953git_config_get_int("gc.rerereunresolved", &cutoff_noresolve); 954git_config(git_default_config, NULL); 955 dir =opendir(git_path("rr-cache")); 956if(!dir) 957die_errno("unable to open rr-cache directory"); 958/* Collect stale conflict IDs ... */ 959while((e =readdir(dir))) { 960if(is_dot_or_dotdot(e->d_name)) 961continue; 962 963 then =rerere_last_used_at(e->d_name); 964if(then) { 965 cutoff = cutoff_resolve; 966}else{ 967 then =rerere_created_at(e->d_name); 968if(!then) 969continue; 970 cutoff = cutoff_noresolve; 971} 972if(then < now - cutoff *86400) 973string_list_append(&to_remove, e->d_name); 974} 975closedir(dir); 976/* ... and then remove them one-by-one */ 977for(i =0; i < to_remove.nr; i++) 978unlink_rr_item(dirname_to_id(to_remove.items[i].string)); 979string_list_clear(&to_remove,0); 980rollback_lock_file(&write_lock); 981} 982 983/* 984 * During a conflict resolution, after "rerere" recorded the 985 * preimages, abandon them if the user did not resolve them or 986 * record their resolutions. And drop $GIT_DIR/MERGE_RR. 987 * 988 * NEEDSWORK: shouldn't we be calling this from "reset --hard"? 989 */ 990voidrerere_clear(struct string_list *merge_rr) 991{ 992int i; 993 994if(setup_rerere(merge_rr,0) <0) 995return; 996 997for(i =0; i < merge_rr->nr; i++) { 998struct rerere_id *id = merge_rr->items[i].util; 999if(!has_rerere_resolution(id))1000unlink_rr_item(id);1001}1002unlink_or_warn(git_path_merge_rr());1003rollback_lock_file(&write_lock);1004}