Andrew's git / gitweb.git / rerere.c
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rerere.con commit Merge branch 'jc/apply-blank-at-eof-fix' into maint (e63f87a)
   1#include "cache.h"
   2#include "string-list.h"
   3#include "rerere.h"
   4#include "xdiff-interface.h"
   5#include "dir.h"
   6#include "resolve-undo.h"
   7#include "ll-merge.h"
   8#include "attr.h"
   9
  10#define RESOLVED 0
  11#define PUNTED 1
  12#define THREE_STAGED 2
  13void *RERERE_RESOLVED = &RERERE_RESOLVED;
  14
  15/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
  16static int rerere_enabled = -1;
  17
  18/* automatically update cleanly resolved paths to the index */
  19static int rerere_autoupdate;
  20
  21static char *merge_rr_path;
  22
  23const char *rerere_path(const char *hex, const char *file)
  24{
  25        return git_path("rr-cache/%s/%s", hex, file);
  26}
  27
  28int has_rerere_resolution(const char *hex)
  29{
  30        struct stat st;
  31        return !stat(rerere_path(hex, "postimage"), &st);
  32}
  33
  34static void read_rr(struct string_list *rr)
  35{
  36        unsigned char sha1[20];
  37        char buf[PATH_MAX];
  38        FILE *in = fopen(merge_rr_path, "r");
  39        if (!in)
  40                return;
  41        while (fread(buf, 40, 1, in) == 1) {
  42                int i;
  43                char *name;
  44                if (get_sha1_hex(buf, sha1))
  45                        die("corrupt MERGE_RR");
  46                buf[40] = '\0';
  47                name = xstrdup(buf);
  48                if (fgetc(in) != '\t')
  49                        die("corrupt MERGE_RR");
  50                for (i = 0; i < sizeof(buf); i++) {
  51                        int c = fgetc(in);
  52                        if (c < 0)
  53                                die("corrupt MERGE_RR");
  54                        buf[i] = c;
  55                        if (c == 0)
  56                                 break;
  57                }
  58                if (i == sizeof(buf))
  59                        die("filename too long");
  60                string_list_insert(rr, buf)->util = name;
  61        }
  62        fclose(in);
  63}
  64
  65static struct lock_file write_lock;
  66
  67static int write_rr(struct string_list *rr, int out_fd)
  68{
  69        int i;
  70        for (i = 0; i < rr->nr; i++) {
  71                const char *path;
  72                int length;
  73                if (!rr->items[i].util)
  74                        continue;
  75                path = rr->items[i].string;
  76                length = strlen(path) + 1;
  77                if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
  78                    write_str_in_full(out_fd, "\t") != 1 ||
  79                    write_in_full(out_fd, path, length) != length)
  80                        die("unable to write rerere record");
  81        }
  82        if (commit_lock_file(&write_lock) != 0)
  83                die("unable to write rerere record");
  84        return 0;
  85}
  86
  87static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
  88{
  89        if (!count || *err)
  90                return;
  91        if (fwrite(p, count, 1, fp) != 1)
  92                *err = errno;
  93}
  94
  95static inline void ferr_puts(const char *s, FILE *fp, int *err)
  96{
  97        ferr_write(s, strlen(s), fp, err);
  98}
  99
 100struct rerere_io {
 101        int (*getline)(struct strbuf *, struct rerere_io *);
 102        FILE *output;
 103        int wrerror;
 104        /* some more stuff */
 105};
 106
 107static void rerere_io_putstr(const char *str, struct rerere_io *io)
 108{
 109        if (io->output)
 110                ferr_puts(str, io->output, &io->wrerror);
 111}
 112
 113static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
 114{
 115        char buf[64];
 116
 117        while (size) {
 118                if (size < sizeof(buf) - 2) {
 119                        memset(buf, ch, size);
 120                        buf[size] = '\n';
 121                        buf[size + 1] = '\0';
 122                        size = 0;
 123                } else {
 124                        int sz = sizeof(buf) - 1;
 125                        if (size <= sz)
 126                                sz -= (sz - size) + 1;
 127                        memset(buf, ch, sz);
 128                        buf[sz] = '\0';
 129                        size -= sz;
 130                }
 131                rerere_io_putstr(buf, io);
 132        }
 133}
 134
 135static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
 136{
 137        if (io->output)
 138                ferr_write(mem, sz, io->output, &io->wrerror);
 139}
 140
 141struct rerere_io_file {
 142        struct rerere_io io;
 143        FILE *input;
 144};
 145
 146static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
 147{
 148        struct rerere_io_file *io = (struct rerere_io_file *)io_;
 149        return strbuf_getwholeline(sb, io->input, '\n');
 150}
 151
 152static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
 153{
 154        while (marker_size--)
 155                if (*buf++ != marker_char)
 156                        return 0;
 157        if (want_sp && *buf != ' ')
 158                return 0;
 159        return isspace(*buf);
 160}
 161
 162static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
 163{
 164        git_SHA_CTX ctx;
 165        int hunk_no = 0;
 166        enum {
 167                RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
 168        } hunk = RR_CONTEXT;
 169        struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
 170        struct strbuf buf = STRBUF_INIT;
 171
 172        if (sha1)
 173                git_SHA1_Init(&ctx);
 174
 175        while (!io->getline(&buf, io)) {
 176                if (is_cmarker(buf.buf, '<', marker_size, 1)) {
 177                        if (hunk != RR_CONTEXT)
 178                                goto bad;
 179                        hunk = RR_SIDE_1;
 180                } else if (is_cmarker(buf.buf, '|', marker_size, 0)) {
 181                        if (hunk != RR_SIDE_1)
 182                                goto bad;
 183                        hunk = RR_ORIGINAL;
 184                } else if (is_cmarker(buf.buf, '=', marker_size, 0)) {
 185                        if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
 186                                goto bad;
 187                        hunk = RR_SIDE_2;
 188                } else if (is_cmarker(buf.buf, '>', marker_size, 1)) {
 189                        if (hunk != RR_SIDE_2)
 190                                goto bad;
 191                        if (strbuf_cmp(&one, &two) > 0)
 192                                strbuf_swap(&one, &two);
 193                        hunk_no++;
 194                        hunk = RR_CONTEXT;
 195                        rerere_io_putconflict('<', marker_size, io);
 196                        rerere_io_putmem(one.buf, one.len, io);
 197                        rerere_io_putconflict('=', marker_size, io);
 198                        rerere_io_putmem(two.buf, two.len, io);
 199                        rerere_io_putconflict('>', marker_size, io);
 200                        if (sha1) {
 201                                git_SHA1_Update(&ctx, one.buf ? one.buf : "",
 202                                            one.len + 1);
 203                                git_SHA1_Update(&ctx, two.buf ? two.buf : "",
 204                                            two.len + 1);
 205                        }
 206                        strbuf_reset(&one);
 207                        strbuf_reset(&two);
 208                } else if (hunk == RR_SIDE_1)
 209                        strbuf_addstr(&one, buf.buf);
 210                else if (hunk == RR_ORIGINAL)
 211                        ; /* discard */
 212                else if (hunk == RR_SIDE_2)
 213                        strbuf_addstr(&two, buf.buf);
 214                else
 215                        rerere_io_putstr(buf.buf, io);
 216                continue;
 217        bad:
 218                hunk = 99; /* force error exit */
 219                break;
 220        }
 221        strbuf_release(&one);
 222        strbuf_release(&two);
 223        strbuf_release(&buf);
 224
 225        if (sha1)
 226                git_SHA1_Final(sha1, &ctx);
 227        if (hunk != RR_CONTEXT)
 228                return -1;
 229        return hunk_no;
 230}
 231
 232static int handle_file(const char *path, unsigned char *sha1, const char *output)
 233{
 234        int hunk_no = 0;
 235        struct rerere_io_file io;
 236        int marker_size = ll_merge_marker_size(path);
 237
 238        memset(&io, 0, sizeof(io));
 239        io.io.getline = rerere_file_getline;
 240        io.input = fopen(path, "r");
 241        io.io.wrerror = 0;
 242        if (!io.input)
 243                return error("Could not open %s", path);
 244
 245        if (output) {
 246                io.io.output = fopen(output, "w");
 247                if (!io.io.output) {
 248                        fclose(io.input);
 249                        return error("Could not write %s", output);
 250                }
 251        }
 252
 253        hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
 254
 255        fclose(io.input);
 256        if (io.io.wrerror)
 257                error("There were errors while writing %s (%s)",
 258                      path, strerror(io.io.wrerror));
 259        if (io.io.output && fclose(io.io.output))
 260                io.io.wrerror = error("Failed to flush %s: %s",
 261                                      path, strerror(errno));
 262
 263        if (hunk_no < 0) {
 264                if (output)
 265                        unlink_or_warn(output);
 266                return error("Could not parse conflict hunks in %s", path);
 267        }
 268        if (io.io.wrerror)
 269                return -1;
 270        return hunk_no;
 271}
 272
 273struct rerere_io_mem {
 274        struct rerere_io io;
 275        struct strbuf input;
 276};
 277
 278static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
 279{
 280        struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
 281        char *ep;
 282        size_t len;
 283
 284        strbuf_release(sb);
 285        if (!io->input.len)
 286                return -1;
 287        ep = strchrnul(io->input.buf, '\n');
 288        if (*ep == '\n')
 289                ep++;
 290        len = ep - io->input.buf;
 291        strbuf_add(sb, io->input.buf, len);
 292        strbuf_remove(&io->input, 0, len);
 293        return 0;
 294}
 295
 296static int handle_cache(const char *path, unsigned char *sha1, const char *output)
 297{
 298        mmfile_t mmfile[3];
 299        mmbuffer_t result = {NULL, 0};
 300        struct cache_entry *ce;
 301        int pos, len, i, hunk_no;
 302        struct rerere_io_mem io;
 303        int marker_size = ll_merge_marker_size(path);
 304
 305        /*
 306         * Reproduce the conflicted merge in-core
 307         */
 308        len = strlen(path);
 309        pos = cache_name_pos(path, len);
 310        if (0 <= pos)
 311                return -1;
 312        pos = -pos - 1;
 313
 314        for (i = 0; i < 3; i++) {
 315                enum object_type type;
 316                unsigned long size;
 317
 318                mmfile[i].size = 0;
 319                mmfile[i].ptr = NULL;
 320                if (active_nr <= pos)
 321                        break;
 322                ce = active_cache[pos++];
 323                if (ce_namelen(ce) != len || memcmp(ce->name, path, len)
 324                    || ce_stage(ce) != i + 1)
 325                        break;
 326                mmfile[i].ptr = read_sha1_file(ce->sha1, &type, &size);
 327                mmfile[i].size = size;
 328        }
 329        for (i = 0; i < 3; i++) {
 330                if (!mmfile[i].ptr && !mmfile[i].size)
 331                        mmfile[i].ptr = xstrdup("");
 332        }
 333        /*
 334         * NEEDSWORK: handle conflicts from merges with
 335         * merge.renormalize set, too
 336         */
 337        ll_merge(&result, path, &mmfile[0], NULL,
 338                 &mmfile[1], "ours",
 339                 &mmfile[2], "theirs", NULL);
 340        for (i = 0; i < 3; i++)
 341                free(mmfile[i].ptr);
 342
 343        memset(&io, 0, sizeof(io));
 344        io.io.getline = rerere_mem_getline;
 345        if (output)
 346                io.io.output = fopen(output, "w");
 347        else
 348                io.io.output = NULL;
 349        strbuf_init(&io.input, 0);
 350        strbuf_attach(&io.input, result.ptr, result.size, result.size);
 351
 352        hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
 353        strbuf_release(&io.input);
 354        if (io.io.output)
 355                fclose(io.io.output);
 356        return hunk_no;
 357}
 358
 359static int check_one_conflict(int i, int *type)
 360{
 361        struct cache_entry *e = active_cache[i];
 362
 363        if (!ce_stage(e)) {
 364                *type = RESOLVED;
 365                return i + 1;
 366        }
 367
 368        *type = PUNTED;
 369        if (ce_stage(e) == 1) {
 370                if (active_nr <= ++i)
 371                        return i + 1;
 372        }
 373
 374        /* Only handle regular files with both stages #2 and #3 */
 375        if (i + 1 < active_nr) {
 376                struct cache_entry *e2 = active_cache[i];
 377                struct cache_entry *e3 = active_cache[i + 1];
 378                if (ce_stage(e2) == 2 &&
 379                    ce_stage(e3) == 3 &&
 380                    ce_same_name(e, e3) &&
 381                    S_ISREG(e2->ce_mode) &&
 382                    S_ISREG(e3->ce_mode))
 383                        *type = THREE_STAGED;
 384        }
 385
 386        /* Skip the entries with the same name */
 387        while (i < active_nr && ce_same_name(e, active_cache[i]))
 388                i++;
 389        return i;
 390}
 391
 392static int find_conflict(struct string_list *conflict)
 393{
 394        int i;
 395        if (read_cache() < 0)
 396                return error("Could not read index");
 397
 398        for (i = 0; i < active_nr;) {
 399                int conflict_type;
 400                struct cache_entry *e = active_cache[i];
 401                i = check_one_conflict(i, &conflict_type);
 402                if (conflict_type == THREE_STAGED)
 403                        string_list_insert(conflict, (const char *)e->name);
 404        }
 405        return 0;
 406}
 407
 408int rerere_remaining(struct string_list *merge_rr)
 409{
 410        int i;
 411        if (read_cache() < 0)
 412                return error("Could not read index");
 413
 414        for (i = 0; i < active_nr;) {
 415                int conflict_type;
 416                struct cache_entry *e = active_cache[i];
 417                i = check_one_conflict(i, &conflict_type);
 418                if (conflict_type == PUNTED)
 419                        string_list_insert(merge_rr, (const char *)e->name);
 420                else if (conflict_type == RESOLVED) {
 421                        struct string_list_item *it;
 422                        it = string_list_lookup(merge_rr, (const char *)e->name);
 423                        if (it != NULL) {
 424                                free(it->util);
 425                                it->util = RERERE_RESOLVED;
 426                        }
 427                }
 428        }
 429        return 0;
 430}
 431
 432static int merge(const char *name, const char *path)
 433{
 434        int ret;
 435        mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
 436        mmbuffer_t result = {NULL, 0};
 437
 438        if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
 439                return 1;
 440
 441        if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
 442                        read_mmfile(&base, rerere_path(name, "preimage")) ||
 443                        read_mmfile(&other, rerere_path(name, "postimage"))) {
 444                ret = 1;
 445                goto out;
 446        }
 447        ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
 448        if (!ret) {
 449                FILE *f;
 450
 451                if (utime(rerere_path(name, "postimage"), NULL) < 0)
 452                        warning("failed utime() on %s: %s",
 453                                        rerere_path(name, "postimage"),
 454                                        strerror(errno));
 455                f = fopen(path, "w");
 456                if (!f)
 457                        return error("Could not open %s: %s", path,
 458                                     strerror(errno));
 459                if (fwrite(result.ptr, result.size, 1, f) != 1)
 460                        error("Could not write %s: %s", path, strerror(errno));
 461                if (fclose(f))
 462                        return error("Writing %s failed: %s", path,
 463                                     strerror(errno));
 464        }
 465
 466out:
 467        free(cur.ptr);
 468        free(base.ptr);
 469        free(other.ptr);
 470        free(result.ptr);
 471
 472        return ret;
 473}
 474
 475static struct lock_file index_lock;
 476
 477static int update_paths(struct string_list *update)
 478{
 479        int i;
 480        int fd = hold_locked_index(&index_lock, 0);
 481        int status = 0;
 482
 483        if (fd < 0)
 484                return -1;
 485
 486        for (i = 0; i < update->nr; i++) {
 487                struct string_list_item *item = &update->items[i];
 488                if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS))
 489                        status = -1;
 490        }
 491
 492        if (!status && active_cache_changed) {
 493                if (write_cache(fd, active_cache, active_nr) ||
 494                    commit_locked_index(&index_lock))
 495                        die("Unable to write new index file");
 496        } else if (fd >= 0)
 497                rollback_lock_file(&index_lock);
 498        return status;
 499}
 500
 501static int do_plain_rerere(struct string_list *rr, int fd)
 502{
 503        struct string_list conflict = STRING_LIST_INIT_DUP;
 504        struct string_list update = STRING_LIST_INIT_DUP;
 505        int i;
 506
 507        find_conflict(&conflict);
 508
 509        /*
 510         * MERGE_RR records paths with conflicts immediately after merge
 511         * failed.  Some of the conflicted paths might have been hand resolved
 512         * in the working tree since then, but the initial run would catch all
 513         * and register their preimages.
 514         */
 515
 516        for (i = 0; i < conflict.nr; i++) {
 517                const char *path = conflict.items[i].string;
 518                if (!string_list_has_string(rr, path)) {
 519                        unsigned char sha1[20];
 520                        char *hex;
 521                        int ret;
 522                        ret = handle_file(path, sha1, NULL);
 523                        if (ret < 1)
 524                                continue;
 525                        hex = xstrdup(sha1_to_hex(sha1));
 526                        string_list_insert(rr, path)->util = hex;
 527                        if (mkdir(git_path("rr-cache/%s", hex), 0755))
 528                                continue;
 529                        handle_file(path, NULL, rerere_path(hex, "preimage"));
 530                        fprintf(stderr, "Recorded preimage for '%s'\n", path);
 531                }
 532        }
 533
 534        /*
 535         * Now some of the paths that had conflicts earlier might have been
 536         * hand resolved.  Others may be similar to a conflict already that
 537         * was resolved before.
 538         */
 539
 540        for (i = 0; i < rr->nr; i++) {
 541                int ret;
 542                const char *path = rr->items[i].string;
 543                const char *name = (const char *)rr->items[i].util;
 544
 545                if (has_rerere_resolution(name)) {
 546                        if (!merge(name, path)) {
 547                                if (rerere_autoupdate)
 548                                        string_list_insert(&update, path);
 549                                fprintf(stderr,
 550                                        "%s '%s' using previous resolution.\n",
 551                                        rerere_autoupdate
 552                                        ? "Staged" : "Resolved",
 553                                        path);
 554                                goto mark_resolved;
 555                        }
 556                }
 557
 558                /* Let's see if we have resolved it. */
 559                ret = handle_file(path, NULL, NULL);
 560                if (ret)
 561                        continue;
 562
 563                fprintf(stderr, "Recorded resolution for '%s'.\n", path);
 564                copy_file(rerere_path(name, "postimage"), path, 0666);
 565        mark_resolved:
 566                rr->items[i].util = NULL;
 567        }
 568
 569        if (update.nr)
 570                update_paths(&update);
 571
 572        return write_rr(rr, fd);
 573}
 574
 575static int git_rerere_config(const char *var, const char *value, void *cb)
 576{
 577        if (!strcmp(var, "rerere.enabled"))
 578                rerere_enabled = git_config_bool(var, value);
 579        else if (!strcmp(var, "rerere.autoupdate"))
 580                rerere_autoupdate = git_config_bool(var, value);
 581        else
 582                return git_default_config(var, value, cb);
 583        return 0;
 584}
 585
 586static int is_rerere_enabled(void)
 587{
 588        const char *rr_cache;
 589        int rr_cache_exists;
 590
 591        if (!rerere_enabled)
 592                return 0;
 593
 594        rr_cache = git_path("rr-cache");
 595        rr_cache_exists = is_directory(rr_cache);
 596        if (rerere_enabled < 0)
 597                return rr_cache_exists;
 598
 599        if (!rr_cache_exists && mkdir_in_gitdir(rr_cache))
 600                die("Could not create directory %s", rr_cache);
 601        return 1;
 602}
 603
 604int setup_rerere(struct string_list *merge_rr, int flags)
 605{
 606        int fd;
 607
 608        git_config(git_rerere_config, NULL);
 609        if (!is_rerere_enabled())
 610                return -1;
 611
 612        if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
 613                rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
 614        merge_rr_path = git_pathdup("MERGE_RR");
 615        fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
 616                                       LOCK_DIE_ON_ERROR);
 617        read_rr(merge_rr);
 618        return fd;
 619}
 620
 621int rerere(int flags)
 622{
 623        struct string_list merge_rr = STRING_LIST_INIT_DUP;
 624        int fd;
 625
 626        fd = setup_rerere(&merge_rr, flags);
 627        if (fd < 0)
 628                return 0;
 629        return do_plain_rerere(&merge_rr, fd);
 630}
 631
 632static int rerere_forget_one_path(const char *path, struct string_list *rr)
 633{
 634        const char *filename;
 635        char *hex;
 636        unsigned char sha1[20];
 637        int ret;
 638
 639        ret = handle_cache(path, sha1, NULL);
 640        if (ret < 1)
 641                return error("Could not parse conflict hunks in '%s'", path);
 642        hex = xstrdup(sha1_to_hex(sha1));
 643        filename = rerere_path(hex, "postimage");
 644        if (unlink(filename))
 645                return (errno == ENOENT
 646                        ? error("no remembered resolution for %s", path)
 647                        : error("cannot unlink %s: %s", filename, strerror(errno)));
 648
 649        handle_cache(path, sha1, rerere_path(hex, "preimage"));
 650        fprintf(stderr, "Updated preimage for '%s'\n", path);
 651
 652
 653        string_list_insert(rr, path)->util = hex;
 654        fprintf(stderr, "Forgot resolution for %s\n", path);
 655        return 0;
 656}
 657
 658int rerere_forget(const char **pathspec)
 659{
 660        int i, fd;
 661        struct string_list conflict = STRING_LIST_INIT_DUP;
 662        struct string_list merge_rr = STRING_LIST_INIT_DUP;
 663
 664        if (read_cache() < 0)
 665                return error("Could not read index");
 666
 667        fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
 668
 669        unmerge_cache(pathspec);
 670        find_conflict(&conflict);
 671        for (i = 0; i < conflict.nr; i++) {
 672                struct string_list_item *it = &conflict.items[i];
 673                if (!match_pathspec(pathspec, it->string, strlen(it->string),
 674                                    0, NULL))
 675                        continue;
 676                rerere_forget_one_path(it->string, &merge_rr);
 677        }
 678        return write_rr(&merge_rr, fd);
 679}
 680
 681static time_t rerere_created_at(const char *name)
 682{
 683        struct stat st;
 684        return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
 685}
 686
 687static time_t rerere_last_used_at(const char *name)
 688{
 689        struct stat st;
 690        return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
 691}
 692
 693static void unlink_rr_item(const char *name)
 694{
 695        unlink(rerere_path(name, "thisimage"));
 696        unlink(rerere_path(name, "preimage"));
 697        unlink(rerere_path(name, "postimage"));
 698        rmdir(git_path("rr-cache/%s", name));
 699}
 700
 701struct rerere_gc_config_cb {
 702        int cutoff_noresolve;
 703        int cutoff_resolve;
 704};
 705
 706static int git_rerere_gc_config(const char *var, const char *value, void *cb)
 707{
 708        struct rerere_gc_config_cb *cf = cb;
 709
 710        if (!strcmp(var, "gc.rerereresolved"))
 711                cf->cutoff_resolve = git_config_int(var, value);
 712        else if (!strcmp(var, "gc.rerereunresolved"))
 713                cf->cutoff_noresolve = git_config_int(var, value);
 714        else
 715                return git_default_config(var, value, cb);
 716        return 0;
 717}
 718
 719void rerere_gc(struct string_list *rr)
 720{
 721        struct string_list to_remove = STRING_LIST_INIT_DUP;
 722        DIR *dir;
 723        struct dirent *e;
 724        int i, cutoff;
 725        time_t now = time(NULL), then;
 726        struct rerere_gc_config_cb cf = { 15, 60 };
 727
 728        git_config(git_rerere_gc_config, &cf);
 729        dir = opendir(git_path("rr-cache"));
 730        if (!dir)
 731                die_errno("unable to open rr-cache directory");
 732        while ((e = readdir(dir))) {
 733                if (is_dot_or_dotdot(e->d_name))
 734                        continue;
 735
 736                then = rerere_last_used_at(e->d_name);
 737                if (then) {
 738                        cutoff = cf.cutoff_resolve;
 739                } else {
 740                        then = rerere_created_at(e->d_name);
 741                        if (!then)
 742                                continue;
 743                        cutoff = cf.cutoff_noresolve;
 744                }
 745                if (then < now - cutoff * 86400)
 746                        string_list_append(&to_remove, e->d_name);
 747        }
 748        closedir(dir);
 749        for (i = 0; i < to_remove.nr; i++)
 750                unlink_rr_item(to_remove.items[i].string);
 751        string_list_clear(&to_remove, 0);
 752}
 753
 754void rerere_clear(struct string_list *merge_rr)
 755{
 756        int i;
 757
 758        for (i = 0; i < merge_rr->nr; i++) {
 759                const char *name = (const char *)merge_rr->items[i].util;
 760                if (!has_rerere_resolution(name))
 761                        unlink_rr_item(name);
 762        }
 763        unlink_or_warn(git_path("MERGE_RR"));
 764}