rerere.c

   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
  15 void *RERERE_RESOLVED = &RERERE_RESOLVED;
  16
  17 /* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
  18 static int rerere_enabled = -1;
  19
  20 /* automatically update cleanly resolved paths to the index */
  21 static int rerere_autoupdate;
  22
  23 static char *merge_rr_path;
  24
  25 const char *rerere_path(const char *hex, const char *file)
  26 {
  27         return git_path("rr-cache/%s/%s", hex, file);
  28 }
  29
  30 static int has_rerere_resolution(const char *hex)
  31 {
  32         struct stat st;
  33         return !stat(rerere_path(hex, "postimage"), &st);
  34 }
  35
  36 static void read_rr(struct string_list *rr)
  37 {
  38         unsigned char sha1[20];
  39         char buf[PATH_MAX];
  40         FILE *in = fopen(merge_rr_path, "r");
  41         if (!in)
  42                 return;
  43         while (fread(buf, 40, 1, in) == 1) {
  44                 int i;
  45                 char *name;
  46                 if (get_sha1_hex(buf, sha1))
  47                         die("corrupt MERGE_RR");
  48                 buf[40] = '\0';
  49                 name = xstrdup(buf);
  50                 if (fgetc(in) != '\t')
  51                         die("corrupt MERGE_RR");
  52                 for (i = 0; i < sizeof(buf); i++) {
  53                         int c = fgetc(in);
  54                         if (c < 0)
  55                                 die("corrupt MERGE_RR");
  56                         buf[i] = c;
  57                         if (c == 0)
  58                                  break;
  59                 }
  60                 if (i == sizeof(buf))
  61                         die("filename too long");
  62                 string_list_insert(rr, buf)->util = name;
  63         }
  64         fclose(in);
  65 }
  66
  67 static struct lock_file write_lock;
  68
  69 static int write_rr(struct string_list *rr, int out_fd)
  70 {
  71         int i;
  72         for (i = 0; i < rr->nr; i++) {
  73                 const char *path;
  74                 int length;
  75                 if (!rr->items[i].util)
  76                         continue;
  77                 path = rr->items[i].string;
  78                 length = strlen(path) + 1;
  79                 if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
  80                     write_str_in_full(out_fd, "\t") != 1 ||
  81                     write_in_full(out_fd, path, length) != length)
  82                         die("unable to write rerere record");
  83         }
  84         if (commit_lock_file(&write_lock) != 0)
  85                 die("unable to write rerere record");
  86         return 0;
  87 }
  88
  89 static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
  90 {
  91         if (!count || *err)
  92                 return;
  93         if (fwrite(p, count, 1, fp) != 1)
  94                 *err = errno;
  95 }
  96
  97 static inline void ferr_puts(const char *s, FILE *fp, int *err)
  98 {
  99         ferr_write(s, strlen(s), fp, err);
 100 }
 101
 102 struct rerere_io {
 103         int (*getline)(struct strbuf *, struct rerere_io *);
 104         FILE *output;
 105         int wrerror;
 106         /* some more stuff */
 107 };
 108
 109 static void rerere_io_putstr(const char *str, struct rerere_io *io)
 110 {
 111         if (io->output)
 112                 ferr_puts(str, io->output, &io->wrerror);
 113 }
 114
 115 static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
 116 {
 117         char buf[64];
 118
 119         while (size) {
 120                 if (size < sizeof(buf) - 2) {
 121                         memset(buf, ch, size);
 122                         buf[size] = '\n';
 123                         buf[size + 1] = '\0';
 124                         size = 0;
 125                 } else {
 126                         int sz = sizeof(buf) - 1;
 127                         if (size <= sz)
 128                                 sz -= (sz - size) + 1;
 129                         memset(buf, ch, sz);
 130                         buf[sz] = '\0';
 131                         size -= sz;
 132                 }
 133                 rerere_io_putstr(buf, io);
 134         }
 135 }
 136
 137 static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
 138 {
 139         if (io->output)
 140                 ferr_write(mem, sz, io->output, &io->wrerror);
 141 }
 142
 143 struct rerere_io_file {
 144         struct rerere_io io;
 145         FILE *input;
 146 };
 147
 148 static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
 149 {
 150         struct rerere_io_file *io = (struct rerere_io_file *)io_;
 151         return strbuf_getwholeline(sb, io->input, '\n');
 152 }
 153
 154 static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
 155 {
 156         while (marker_size--)
 157                 if (*buf++ != marker_char)
 158                         return 0;
 159         if (want_sp && *buf != ' ')
 160                 return 0;
 161         return isspace(*buf);
 162 }
 163
 164 static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
 165 {
 166         git_SHA_CTX ctx;
 167         int hunk_no = 0;
 168         enum {
 169                 RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
 170         } hunk = RR_CONTEXT;
 171         struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
 172         struct strbuf buf = STRBUF_INIT;
 173
 174         if (sha1)
 175                 git_SHA1_Init(&ctx);
 176
 177         while (!io->getline(&buf, io)) {
 178                 if (is_cmarker(buf.buf, '<', marker_size, 1)) {
 179                         if (hunk != RR_CONTEXT)
 180                                 goto bad;
 181                         hunk = RR_SIDE_1;
 182                 } else if (is_cmarker(buf.buf, '|', marker_size, 0)) {
 183                         if (hunk != RR_SIDE_1)
 184                                 goto bad;
 185                         hunk = RR_ORIGINAL;
 186                 } else if (is_cmarker(buf.buf, '=', marker_size, 0)) {
 187                         if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
 188                                 goto bad;
 189                         hunk = RR_SIDE_2;
 190                 } else if (is_cmarker(buf.buf, '>', marker_size, 1)) {
 191                         if (hunk != RR_SIDE_2)
 192                                 goto bad;
 193                         if (strbuf_cmp(&one, &two) > 0)
 194                                 strbuf_swap(&one, &two);
 195                         hunk_no++;
 196                         hunk = RR_CONTEXT;
 197                         rerere_io_putconflict('<', marker_size, io);
 198                         rerere_io_putmem(one.buf, one.len, io);
 199                         rerere_io_putconflict('=', marker_size, io);
 200                         rerere_io_putmem(two.buf, two.len, io);
 201                         rerere_io_putconflict('>', marker_size, io);
 202                         if (sha1) {
 203                                 git_SHA1_Update(&ctx, one.buf ? one.buf : "",
 204                                             one.len + 1);
 205                                 git_SHA1_Update(&ctx, two.buf ? two.buf : "",
 206                                             two.len + 1);
 207                         }
 208                         strbuf_reset(&one);
 209                         strbuf_reset(&two);
 210                 } else if (hunk == RR_SIDE_1)
 211                         strbuf_addbuf(&one, &buf);
 212                 else if (hunk == RR_ORIGINAL)
 213                         ; /* discard */
 214                 else if (hunk == RR_SIDE_2)
 215                         strbuf_addbuf(&two, &buf);
 216                 else
 217                         rerere_io_putstr(buf.buf, io);
 218                 continue;
 219         bad:
 220                 hunk = 99; /* force error exit */
 221                 break;
 222         }
 223         strbuf_release(&one);
 224         strbuf_release(&two);
 225         strbuf_release(&buf);
 226
 227         if (sha1)
 228                 git_SHA1_Final(sha1, &ctx);
 229         if (hunk != RR_CONTEXT)
 230                 return -1;
 231         return hunk_no;
 232 }
 233
 234 static int handle_file(const char *path, unsigned char *sha1, const char *output)
 235 {
 236         int hunk_no = 0;
 237         struct rerere_io_file io;
 238         int marker_size = ll_merge_marker_size(path);
 239
 240         memset(&io, 0, sizeof(io));
 241         io.io.getline = rerere_file_getline;
 242         io.input = fopen(path, "r");
 243         io.io.wrerror = 0;
 244         if (!io.input)
 245                 return error("Could not open %s", path);
 246
 247         if (output) {
 248                 io.io.output = fopen(output, "w");
 249                 if (!io.io.output) {
 250                         fclose(io.input);
 251                         return error("Could not write %s", output);
 252                 }
 253         }
 254
 255         hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
 256
 257         fclose(io.input);
 258         if (io.io.wrerror)
 259                 error("There were errors while writing %s (%s)",
 260                       path, strerror(io.io.wrerror));
 261         if (io.io.output && fclose(io.io.output))
 262                 io.io.wrerror = error("Failed to flush %s: %s",
 263                                       path, strerror(errno));
 264
 265         if (hunk_no < 0) {
 266                 if (output)
 267                         unlink_or_warn(output);
 268                 return error("Could not parse conflict hunks in %s", path);
 269         }
 270         if (io.io.wrerror)
 271                 return -1;
 272         return hunk_no;
 273 }
 274
 275 struct rerere_io_mem {
 276         struct rerere_io io;
 277         struct strbuf input;
 278 };
 279
 280 static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
 281 {
 282         struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
 283         char *ep;
 284         size_t len;
 285
 286         strbuf_release(sb);
 287         if (!io->input.len)
 288                 return -1;
 289         ep = memchr(io->input.buf, '\n', io->input.len);
 290         if (!ep)
 291                 ep = io->input.buf + io->input.len;
 292         else if (*ep == '\n')
 293                 ep++;
 294         len = ep - io->input.buf;
 295         strbuf_add(sb, io->input.buf, len);
 296         strbuf_remove(&io->input, 0, len);
 297         return 0;
 298 }
 299
 300 static int handle_cache(const char *path, unsigned char *sha1, const char *output)
 301 {
 302         mmfile_t mmfile[3] = {{NULL}};
 303         mmbuffer_t result = {NULL, 0};
 304         const struct cache_entry *ce;
 305         int pos, len, i, hunk_no;
 306         struct rerere_io_mem io;
 307         int marker_size = ll_merge_marker_size(path);
 308
 309         /*
 310          * Reproduce the conflicted merge in-core
 311          */
 312         len = strlen(path);
 313         pos = cache_name_pos(path, len);
 314         if (0 <= pos)
 315                 return -1;
 316         pos = -pos - 1;
 317
 318         for (i = 0; i < 3; i++) {
 319                 enum object_type type;
 320                 unsigned long size;
 321                 int j;
 322
 323                 if (active_nr <= pos)
 324                         break;
 325                 ce = active_cache[pos++];
 326                 if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
 327                         continue;
 328                 j = ce_stage(ce) - 1;
 329                 mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size);
 330                 mmfile[j].size = size;
 331         }
 332         for (i = 0; i < 3; i++) {
 333                 if (!mmfile[i].ptr && !mmfile[i].size)
 334                         mmfile[i].ptr = xstrdup("");
 335         }
 336         /*
 337          * NEEDSWORK: handle conflicts from merges with
 338          * merge.renormalize set, too
 339          */
 340         ll_merge(&result, path, &mmfile[0], NULL,
 341                  &mmfile[1], "ours",
 342                  &mmfile[2], "theirs", NULL);
 343         for (i = 0; i < 3; i++)
 344                 free(mmfile[i].ptr);
 345
 346         memset(&io, 0, sizeof(io));
 347         io.io.getline = rerere_mem_getline;
 348         if (output)
 349                 io.io.output = fopen(output, "w");
 350         else
 351                 io.io.output = NULL;
 352         strbuf_init(&io.input, 0);
 353         strbuf_attach(&io.input, result.ptr, result.size, result.size);
 354
 355         hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
 356         strbuf_release(&io.input);
 357         if (io.io.output)
 358                 fclose(io.io.output);
 359         return hunk_no;
 360 }
 361
 362 static int check_one_conflict(int i, int *type)
 363 {
 364         const struct cache_entry *e = active_cache[i];
 365
 366         if (!ce_stage(e)) {
 367                 *type = RESOLVED;
 368                 return i + 1;
 369         }
 370
 371         *type = PUNTED;
 372         if (ce_stage(e) == 1) {
 373                 if (active_nr <= ++i)
 374                         return i + 1;
 375         }
 376
 377         /* Only handle regular files with both stages #2 and #3 */
 378         if (i + 1 < active_nr) {
 379                 const struct cache_entry *e2 = active_cache[i];
 380                 const struct cache_entry *e3 = active_cache[i + 1];
 381                 if (ce_stage(e2) == 2 &&
 382                     ce_stage(e3) == 3 &&
 383                     ce_same_name(e, e3) &&
 384                     S_ISREG(e2->ce_mode) &&
 385                     S_ISREG(e3->ce_mode))
 386                         *type = THREE_STAGED;
 387         }
 388
 389         /* Skip the entries with the same name */
 390         while (i < active_nr && ce_same_name(e, active_cache[i]))
 391                 i++;
 392         return i;
 393 }
 394
 395 static int find_conflict(struct string_list *conflict)
 396 {
 397         int i;
 398         if (read_cache() < 0)
 399                 return error("Could not read index");
 400
 401         for (i = 0; i < active_nr;) {
 402                 int conflict_type;
 403                 const struct cache_entry *e = active_cache[i];
 404                 i = check_one_conflict(i, &conflict_type);
 405                 if (conflict_type == THREE_STAGED)
 406                         string_list_insert(conflict, (const char *)e->name);
 407         }
 408         return 0;
 409 }
 410
 411 int rerere_remaining(struct string_list *merge_rr)
 412 {
 413         int i;
 414         if (read_cache() < 0)
 415                 return error("Could not read index");
 416
 417         for (i = 0; i < active_nr;) {
 418                 int conflict_type;
 419                 const struct cache_entry *e = active_cache[i];
 420                 i = check_one_conflict(i, &conflict_type);
 421                 if (conflict_type == PUNTED)
 422                         string_list_insert(merge_rr, (const char *)e->name);
 423                 else if (conflict_type == RESOLVED) {
 424                         struct string_list_item *it;
 425                         it = string_list_lookup(merge_rr, (const char *)e->name);
 426                         if (it != NULL) {
 427                                 free(it->util);
 428                                 it->util = RERERE_RESOLVED;
 429                         }
 430                 }
 431         }
 432         return 0;
 433 }
 434
 435 static int merge(const char *name, const char *path)
 436 {
 437         int ret;
 438         mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
 439         mmbuffer_t result = {NULL, 0};
 440
 441         if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
 442                 return 1;
 443
 444         if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
 445                         read_mmfile(&base, rerere_path(name, "preimage")) ||
 446                         read_mmfile(&other, rerere_path(name, "postimage"))) {
 447                 ret = 1;
 448                 goto out;
 449         }
 450         ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
 451         if (!ret) {
 452                 FILE *f;
 453
 454                 if (utime(rerere_path(name, "postimage"), NULL) < 0)
 455                         warning("failed utime() on %s: %s",
 456                                         rerere_path(name, "postimage"),
 457                                         strerror(errno));
 458                 f = fopen(path, "w");
 459                 if (!f)
 460                         return error("Could not open %s: %s", path,
 461                                      strerror(errno));
 462                 if (fwrite(result.ptr, result.size, 1, f) != 1)
 463                         error("Could not write %s: %s", path, strerror(errno));
 464                 if (fclose(f))
 465                         return error("Writing %s failed: %s", path,
 466                                      strerror(errno));
 467         }
 468
 469 out:
 470         free(cur.ptr);
 471         free(base.ptr);
 472         free(other.ptr);
 473         free(result.ptr);
 474
 475         return ret;
 476 }
 477
 478 static struct lock_file index_lock;
 479
 480 static int update_paths(struct string_list *update)
 481 {
 482         int i;
 483         int fd = hold_locked_index(&index_lock, 0);
 484         int status = 0;
 485
 486         if (fd < 0)
 487                 return -1;
 488
 489         for (i = 0; i < update->nr; i++) {
 490                 struct string_list_item *item = &update->items[i];
 491                 if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS))
 492                         status = -1;
 493         }
 494
 495         if (!status && active_cache_changed) {
 496                 if (write_locked_index(&the_index, &index_lock, COMMIT_LOCK))
 497                         die("Unable to write new index file");
 498         } else if (fd >= 0)
 499                 rollback_lock_file(&index_lock);
 500         return status;
 501 }
 502
 503 static int do_plain_rerere(struct string_list *rr, int fd)
 504 {
 505         struct string_list conflict = STRING_LIST_INIT_DUP;
 506         struct string_list update = STRING_LIST_INIT_DUP;
 507         int i;
 508
 509         find_conflict(&conflict);
 510
 511         /*
 512          * MERGE_RR records paths with conflicts immediately after merge
 513          * failed.  Some of the conflicted paths might have been hand resolved
 514          * in the working tree since then, but the initial run would catch all
 515          * and register their preimages.
 516          */
 517
 518         for (i = 0; i < conflict.nr; i++) {
 519                 const char *path = conflict.items[i].string;
 520                 if (!string_list_has_string(rr, path)) {
 521                         unsigned char sha1[20];
 522                         char *hex;
 523                         int ret;
 524                         ret = handle_file(path, sha1, NULL);
 525                         if (ret < 1)
 526                                 continue;
 527                         hex = xstrdup(sha1_to_hex(sha1));
 528                         string_list_insert(rr, path)->util = hex;
 529                         if (mkdir_in_gitdir(git_path("rr-cache/%s", hex)))
 530                                 continue;
 531                         handle_file(path, NULL, rerere_path(hex, "preimage"));
 532                         fprintf(stderr, "Recorded preimage for '%s'\n", path);
 533                 }
 534         }
 535
 536         /*
 537          * Now some of the paths that had conflicts earlier might have been
 538          * hand resolved.  Others may be similar to a conflict already that
 539          * was resolved before.
 540          */
 541
 542         for (i = 0; i < rr->nr; i++) {
 543                 int ret;
 544                 const char *path = rr->items[i].string;
 545                 const char *name = (const char *)rr->items[i].util;
 546
 547                 if (has_rerere_resolution(name)) {
 548                         if (!merge(name, path)) {
 549                                 const char *msg;
 550                                 if (rerere_autoupdate) {
 551                                         string_list_insert(&update, path);
 552                                         msg = "Staged '%s' using previous resolution.\n";
 553                                 } else
 554                                         msg = "Resolved '%s' using previous resolution.\n";
 555                                 fprintf(stderr, msg, path);
 556                                 goto mark_resolved;
 557                         }
 558                 }
 559
 560                 /* Let's see if we have resolved it. */
 561                 ret = handle_file(path, NULL, NULL);
 562                 if (ret)
 563                         continue;
 564
 565                 fprintf(stderr, "Recorded resolution for '%s'.\n", path);
 566                 copy_file(rerere_path(name, "postimage"), path, 0666);
 567         mark_resolved:
 568                 rr->items[i].util = NULL;
 569         }
 570
 571         if (update.nr)
 572                 update_paths(&update);
 573
 574         return write_rr(rr, fd);
 575 }
 576
 577 static void git_rerere_config(void)
 578 {
 579         git_config_get_bool("rerere.enabled", &rerere_enabled);
 580         git_config_get_bool("rerere.autoupdate", &rerere_autoupdate);
 581         git_config(git_default_config, NULL);
 582 }
 583
 584 static int is_rerere_enabled(void)
 585 {
 586         const char *rr_cache;
 587         int rr_cache_exists;
 588
 589         if (!rerere_enabled)
 590                 return 0;
 591
 592         rr_cache = git_path("rr-cache");
 593         rr_cache_exists = is_directory(rr_cache);
 594         if (rerere_enabled < 0)
 595                 return rr_cache_exists;
 596
 597         if (!rr_cache_exists && mkdir_in_gitdir(rr_cache))
 598                 die("Could not create directory %s", rr_cache);
 599         return 1;
 600 }
 601
 602 int setup_rerere(struct string_list *merge_rr, int flags)
 603 {
 604         int fd;
 605
 606         git_rerere_config();
 607         if (!is_rerere_enabled())
 608                 return -1;
 609
 610         if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
 611                 rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
 612         merge_rr_path = git_pathdup("MERGE_RR");
 613         fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
 614                                        LOCK_DIE_ON_ERROR);
 615         read_rr(merge_rr);
 616         return fd;
 617 }
 618
 619 int rerere(int flags)
 620 {
 621         struct string_list merge_rr = STRING_LIST_INIT_DUP;
 622         int fd;
 623
 624         fd = setup_rerere(&merge_rr, flags);
 625         if (fd < 0)
 626                 return 0;
 627         return do_plain_rerere(&merge_rr, fd);
 628 }
 629
 630 static int rerere_forget_one_path(const char *path, struct string_list *rr)
 631 {
 632         const char *filename;
 633         char *hex;
 634         unsigned char sha1[20];
 635         int ret;
 636
 637         ret = handle_cache(path, sha1, NULL);
 638         if (ret < 1)
 639                 return error("Could not parse conflict hunks in '%s'", path);
 640         hex = xstrdup(sha1_to_hex(sha1));
 641         filename = rerere_path(hex, "postimage");
 642         if (unlink(filename))
 643                 return (errno == ENOENT
 644                         ? error("no remembered resolution for %s", path)
 645                         : error("cannot unlink %s: %s", filename, strerror(errno)));
 646
 647         handle_cache(path, sha1, rerere_path(hex, "preimage"));
 648         fprintf(stderr, "Updated preimage for '%s'\n", path);
 649
 650
 651         string_list_insert(rr, path)->util = hex;
 652         fprintf(stderr, "Forgot resolution for %s\n", path);
 653         return 0;
 654 }
 655
 656 int rerere_forget(struct pathspec *pathspec)
 657 {
 658         int i, fd;
 659         struct string_list conflict = STRING_LIST_INIT_DUP;
 660         struct string_list merge_rr = STRING_LIST_INIT_DUP;
 661
 662         if (read_cache() < 0)
 663                 return error("Could not read index");
 664
 665         fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
 666
 667         unmerge_cache(pathspec);
 668         find_conflict(&conflict);
 669         for (i = 0; i < conflict.nr; i++) {
 670                 struct string_list_item *it = &conflict.items[i];
 671                 if (!match_pathspec(pathspec, it->string,
 672                                     strlen(it->string), 0, NULL, 0))
 673                         continue;
 674                 rerere_forget_one_path(it->string, &merge_rr);
 675         }
 676         return write_rr(&merge_rr, fd);
 677 }
 678
 679 static time_t rerere_created_at(const char *name)
 680 {
 681         struct stat st;
 682         return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
 683 }
 684
 685 static time_t rerere_last_used_at(const char *name)
 686 {
 687         struct stat st;
 688         return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
 689 }
 690
 691 static void unlink_rr_item(const char *name)
 692 {
 693         unlink(rerere_path(name, "thisimage"));
 694         unlink(rerere_path(name, "preimage"));
 695         unlink(rerere_path(name, "postimage"));
 696         rmdir(git_path("rr-cache/%s", name));
 697 }
 698
 699 void rerere_gc(struct string_list *rr)
 700 {
 701         struct string_list to_remove = STRING_LIST_INIT_DUP;
 702         DIR *dir;
 703         struct dirent *e;
 704         int i, cutoff;
 705         time_t now = time(NULL), then;
 706         int cutoff_noresolve = 15;
 707         int cutoff_resolve = 60;
 708
 709         git_config_get_int("gc.rerereresolved", &cutoff_resolve);
 710         git_config_get_int("gc.rerereunresolved", &cutoff_noresolve);
 711         git_config(git_default_config, NULL);
 712         dir = opendir(git_path("rr-cache"));
 713         if (!dir)
 714                 die_errno("unable to open rr-cache directory");
 715         while ((e = readdir(dir))) {
 716                 if (is_dot_or_dotdot(e->d_name))
 717                         continue;
 718
 719                 then = rerere_last_used_at(e->d_name);
 720                 if (then) {
 721                         cutoff = cutoff_resolve;
 722                 } else {
 723                         then = rerere_created_at(e->d_name);
 724                         if (!then)
 725                                 continue;
 726                         cutoff = cutoff_noresolve;
 727                 }
 728                 if (then < now - cutoff * 86400)
 729                         string_list_append(&to_remove, e->d_name);
 730         }
 731         closedir(dir);
 732         for (i = 0; i < to_remove.nr; i++)
 733                 unlink_rr_item(to_remove.items[i].string);
 734         string_list_clear(&to_remove, 0);
 735 }
 736
 737 void rerere_clear(struct string_list *merge_rr)
 738 {
 739         int i;
 740
 741         for (i = 0; i < merge_rr->nr; i++) {
 742                 const char *name = (const char *)merge_rr->items[i].util;
 743                 if (!has_rerere_resolution(name))
 744                         unlink_rr_item(name);
 745         }
 746         unlink_or_warn(git_path("MERGE_RR"));
 747 }