Andrew's git / gitweb.git / rerere.c
?
rerere.con commit Merge branch 'fp/submodule-checkout-mode' (1aeb10a)
   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#include "pathspec.h"
  10
  11#define RESOLVED 0
  12#define PUNTED 1
  13#define THREE_STAGED 2
  14void *RERERE_RESOLVED = &RERERE_RESOLVED;
  15
  16/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
  17static int rerere_enabled = -1;
  18
  19/* automatically update cleanly resolved paths to the index */
  20static int rerere_autoupdate;
  21
  22static char *merge_rr_path;
  23
  24const char *rerere_path(const char *hex, const char *file)
  25{
  26        return git_path("rr-cache/%s/%s", hex, file);
  27}
  28
  29static int has_rerere_resolution(const char *hex)
  30{
  31        struct stat st;
  32        return !stat(rerere_path(hex, "postimage"), &st);
  33}
  34
  35static void read_rr(struct string_list *rr)
  36{
  37        unsigned char sha1[20];
  38        char buf[PATH_MAX];
  39        FILE *in = fopen(merge_rr_path, "r");
  40        if (!in)
  41                return;
  42        while (fread(buf, 40, 1, in) == 1) {
  43                int i;
  44                char *name;
  45                if (get_sha1_hex(buf, sha1))
  46                        die("corrupt MERGE_RR");
  47                buf[40] = '\0';
  48                name = xstrdup(buf);
  49                if (fgetc(in) != '\t')
  50                        die("corrupt MERGE_RR");
  51                for (i = 0; i < sizeof(buf); i++) {
  52                        int c = fgetc(in);
  53                        if (c < 0)
  54                                die("corrupt MERGE_RR");
  55                        buf[i] = c;
  56                        if (c == 0)
  57                                 break;
  58                }
  59                if (i == sizeof(buf))
  60                        die("filename too long");
  61                string_list_insert(rr, buf)->util = name;
  62        }
  63        fclose(in);
  64}
  65
  66static struct lock_file write_lock;
  67
  68static int write_rr(struct string_list *rr, int out_fd)
  69{
  70        int i;
  71        for (i = 0; i < rr->nr; i++) {
  72                const char *path;
  73                int length;
  74                if (!rr->items[i].util)
  75                        continue;
  76                path = rr->items[i].string;
  77                length = strlen(path) + 1;
  78                if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
  79                    write_str_in_full(out_fd, "\t") != 1 ||
  80                    write_in_full(out_fd, path, length) != length)
  81                        die("unable to write rerere record");
  82        }
  83        if (commit_lock_file(&write_lock) != 0)
  84                die("unable to write rerere record");
  85        return 0;
  86}
  87
  88static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
  89{
  90        if (!count || *err)
  91                return;
  92        if (fwrite(p, count, 1, fp) != 1)
  93                *err = errno;
  94}
  95
  96static inline void ferr_puts(const char *s, FILE *fp, int *err)
  97{
  98        ferr_write(s, strlen(s), fp, err);
  99}
 100
 101struct rerere_io {
 102        int (*getline)(struct strbuf *, struct rerere_io *);
 103        FILE *output;
 104        int wrerror;
 105        /* some more stuff */
 106};
 107
 108static void rerere_io_putstr(const char *str, struct rerere_io *io)
 109{
 110        if (io->output)
 111                ferr_puts(str, io->output, &io->wrerror);
 112}
 113
 114static void rerere_io_putconflict(int ch, int size, struct rerere_io *io)
 115{
 116        char buf[64];
 117
 118        while (size) {
 119                if (size < sizeof(buf) - 2) {
 120                        memset(buf, ch, size);
 121                        buf[size] = '\n';
 122                        buf[size + 1] = '\0';
 123                        size = 0;
 124                } else {
 125                        int sz = sizeof(buf) - 1;
 126                        if (size <= sz)
 127                                sz -= (sz - size) + 1;
 128                        memset(buf, ch, sz);
 129                        buf[sz] = '\0';
 130                        size -= sz;
 131                }
 132                rerere_io_putstr(buf, io);
 133        }
 134}
 135
 136static void rerere_io_putmem(const char *mem, size_t sz, struct rerere_io *io)
 137{
 138        if (io->output)
 139                ferr_write(mem, sz, io->output, &io->wrerror);
 140}
 141
 142struct rerere_io_file {
 143        struct rerere_io io;
 144        FILE *input;
 145};
 146
 147static int rerere_file_getline(struct strbuf *sb, struct rerere_io *io_)
 148{
 149        struct rerere_io_file *io = (struct rerere_io_file *)io_;
 150        return strbuf_getwholeline(sb, io->input, '\n');
 151}
 152
 153static int is_cmarker(char *buf, int marker_char, int marker_size, int want_sp)
 154{
 155        while (marker_size--)
 156                if (*buf++ != marker_char)
 157                        return 0;
 158        if (want_sp && *buf != ' ')
 159                return 0;
 160        return isspace(*buf);
 161}
 162
 163static int handle_path(unsigned char *sha1, struct rerere_io *io, int marker_size)
 164{
 165        git_SHA_CTX ctx;
 166        int hunk_no = 0;
 167        enum {
 168                RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL
 169        } hunk = RR_CONTEXT;
 170        struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
 171        struct strbuf buf = STRBUF_INIT;
 172
 173        if (sha1)
 174                git_SHA1_Init(&ctx);
 175
 176        while (!io->getline(&buf, io)) {
 177                if (is_cmarker(buf.buf, '<', marker_size, 1)) {
 178                        if (hunk != RR_CONTEXT)
 179                                goto bad;
 180                        hunk = RR_SIDE_1;
 181                } else if (is_cmarker(buf.buf, '|', marker_size, 0)) {
 182                        if (hunk != RR_SIDE_1)
 183                                goto bad;
 184                        hunk = RR_ORIGINAL;
 185                } else if (is_cmarker(buf.buf, '=', marker_size, 0)) {
 186                        if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
 187                                goto bad;
 188                        hunk = RR_SIDE_2;
 189                } else if (is_cmarker(buf.buf, '>', marker_size, 1)) {
 190                        if (hunk != RR_SIDE_2)
 191                                goto bad;
 192                        if (strbuf_cmp(&one, &two) > 0)
 193                                strbuf_swap(&one, &two);
 194                        hunk_no++;
 195                        hunk = RR_CONTEXT;
 196                        rerere_io_putconflict('<', marker_size, io);
 197                        rerere_io_putmem(one.buf, one.len, io);
 198                        rerere_io_putconflict('=', marker_size, io);
 199                        rerere_io_putmem(two.buf, two.len, io);
 200                        rerere_io_putconflict('>', marker_size, io);
 201                        if (sha1) {
 202                                git_SHA1_Update(&ctx, one.buf ? one.buf : "",
 203                                            one.len + 1);
 204                                git_SHA1_Update(&ctx, two.buf ? two.buf : "",
 205                                            two.len + 1);
 206                        }
 207                        strbuf_reset(&one);
 208                        strbuf_reset(&two);
 209                } else if (hunk == RR_SIDE_1)
 210                        strbuf_addstr(&one, buf.buf);
 211                else if (hunk == RR_ORIGINAL)
 212                        ; /* discard */
 213                else if (hunk == RR_SIDE_2)
 214                        strbuf_addstr(&two, buf.buf);
 215                else
 216                        rerere_io_putstr(buf.buf, io);
 217                continue;
 218        bad:
 219                hunk = 99; /* force error exit */
 220                break;
 221        }
 222        strbuf_release(&one);
 223        strbuf_release(&two);
 224        strbuf_release(&buf);
 225
 226        if (sha1)
 227                git_SHA1_Final(sha1, &ctx);
 228        if (hunk != RR_CONTEXT)
 229                return -1;
 230        return hunk_no;
 231}
 232
 233static int handle_file(const char *path, unsigned char *sha1, const char *output)
 234{
 235        int hunk_no = 0;
 236        struct rerere_io_file io;
 237        int marker_size = ll_merge_marker_size(path);
 238
 239        memset(&io, 0, sizeof(io));
 240        io.io.getline = rerere_file_getline;
 241        io.input = fopen(path, "r");
 242        io.io.wrerror = 0;
 243        if (!io.input)
 244                return error("Could not open %s", path);
 245
 246        if (output) {
 247                io.io.output = fopen(output, "w");
 248                if (!io.io.output) {
 249                        fclose(io.input);
 250                        return error("Could not write %s", output);
 251                }
 252        }
 253
 254        hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
 255
 256        fclose(io.input);
 257        if (io.io.wrerror)
 258                error("There were errors while writing %s (%s)",
 259                      path, strerror(io.io.wrerror));
 260        if (io.io.output && fclose(io.io.output))
 261                io.io.wrerror = error("Failed to flush %s: %s",
 262                                      path, strerror(errno));
 263
 264        if (hunk_no < 0) {
 265                if (output)
 266                        unlink_or_warn(output);
 267                return error("Could not parse conflict hunks in %s", path);
 268        }
 269        if (io.io.wrerror)
 270                return -1;
 271        return hunk_no;
 272}
 273
 274struct rerere_io_mem {
 275        struct rerere_io io;
 276        struct strbuf input;
 277};
 278
 279static int rerere_mem_getline(struct strbuf *sb, struct rerere_io *io_)
 280{
 281        struct rerere_io_mem *io = (struct rerere_io_mem *)io_;
 282        char *ep;
 283        size_t len;
 284
 285        strbuf_release(sb);
 286        if (!io->input.len)
 287                return -1;
 288        ep = memchr(io->input.buf, '\n', io->input.len);
 289        if (!ep)
 290                ep = io->input.buf + io->input.len;
 291        else if (*ep == '\n')
 292                ep++;
 293        len = ep - io->input.buf;
 294        strbuf_add(sb, io->input.buf, len);
 295        strbuf_remove(&io->input, 0, len);
 296        return 0;
 297}
 298
 299static int handle_cache(const char *path, unsigned char *sha1, const char *output)
 300{
 301        mmfile_t mmfile[3] = {{NULL}};
 302        mmbuffer_t result = {NULL, 0};
 303        const struct cache_entry *ce;
 304        int pos, len, i, hunk_no;
 305        struct rerere_io_mem io;
 306        int marker_size = ll_merge_marker_size(path);
 307
 308        /*
 309         * Reproduce the conflicted merge in-core
 310         */
 311        len = strlen(path);
 312        pos = cache_name_pos(path, len);
 313        if (0 <= pos)
 314                return -1;
 315        pos = -pos - 1;
 316
 317        for (i = 0; i < 3; i++) {
 318                enum object_type type;
 319                unsigned long size;
 320                int j;
 321
 322                if (active_nr <= pos)
 323                        break;
 324                ce = active_cache[pos++];
 325                if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
 326                        continue;
 327                j = ce_stage(ce) - 1;
 328                mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size);
 329                mmfile[j].size = size;
 330        }
 331        for (i = 0; i < 3; i++) {
 332                if (!mmfile[i].ptr && !mmfile[i].size)
 333                        mmfile[i].ptr = xstrdup("");
 334        }
 335        /*
 336         * NEEDSWORK: handle conflicts from merges with
 337         * merge.renormalize set, too
 338         */
 339        ll_merge(&result, path, &mmfile[0], NULL,
 340                 &mmfile[1], "ours",
 341                 &mmfile[2], "theirs", NULL);
 342        for (i = 0; i < 3; i++)
 343                free(mmfile[i].ptr);
 344
 345        memset(&io, 0, sizeof(io));
 346        io.io.getline = rerere_mem_getline;
 347        if (output)
 348                io.io.output = fopen(output, "w");
 349        else
 350                io.io.output = NULL;
 351        strbuf_init(&io.input, 0);
 352        strbuf_attach(&io.input, result.ptr, result.size, result.size);
 353
 354        hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
 355        strbuf_release(&io.input);
 356        if (io.io.output)
 357                fclose(io.io.output);
 358        return hunk_no;
 359}
 360
 361static int check_one_conflict(int i, int *type)
 362{
 363        const struct cache_entry *e = active_cache[i];
 364
 365        if (!ce_stage(e)) {
 366                *type = RESOLVED;
 367                return i + 1;
 368        }
 369
 370        *type = PUNTED;
 371        if (ce_stage(e) == 1) {
 372                if (active_nr <= ++i)
 373                        return i + 1;
 374        }
 375
 376        /* Only handle regular files with both stages #2 and #3 */
 377        if (i + 1 < active_nr) {
 378                const struct cache_entry *e2 = active_cache[i];
 379                const struct cache_entry *e3 = active_cache[i + 1];
 380                if (ce_stage(e2) == 2 &&
 381                    ce_stage(e3) == 3 &&
 382                    ce_same_name(e, e3) &&
 383                    S_ISREG(e2->ce_mode) &&
 384                    S_ISREG(e3->ce_mode))
 385                        *type = THREE_STAGED;
 386        }
 387
 388        /* Skip the entries with the same name */
 389        while (i < active_nr && ce_same_name(e, active_cache[i]))
 390                i++;
 391        return i;
 392}
 393
 394static int find_conflict(struct string_list *conflict)
 395{
 396        int i;
 397        if (read_cache() < 0)
 398                return error("Could not read index");
 399
 400        for (i = 0; i < active_nr;) {
 401                int conflict_type;
 402                const struct cache_entry *e = active_cache[i];
 403                i = check_one_conflict(i, &conflict_type);
 404                if (conflict_type == THREE_STAGED)
 405                        string_list_insert(conflict, (const char *)e->name);
 406        }
 407        return 0;
 408}
 409
 410int rerere_remaining(struct string_list *merge_rr)
 411{
 412        int i;
 413        if (read_cache() < 0)
 414                return error("Could not read index");
 415
 416        for (i = 0; i < active_nr;) {
 417                int conflict_type;
 418                const struct cache_entry *e = active_cache[i];
 419                i = check_one_conflict(i, &conflict_type);
 420                if (conflict_type == PUNTED)
 421                        string_list_insert(merge_rr, (const char *)e->name);
 422                else if (conflict_type == RESOLVED) {
 423                        struct string_list_item *it;
 424                        it = string_list_lookup(merge_rr, (const char *)e->name);
 425                        if (it != NULL) {
 426                                free(it->util);
 427                                it->util = RERERE_RESOLVED;
 428                        }
 429                }
 430        }
 431        return 0;
 432}
 433
 434static int merge(const char *name, const char *path)
 435{
 436        int ret;
 437        mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
 438        mmbuffer_t result = {NULL, 0};
 439
 440        if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
 441                return 1;
 442
 443        if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
 444                        read_mmfile(&base, rerere_path(name, "preimage")) ||
 445                        read_mmfile(&other, rerere_path(name, "postimage"))) {
 446                ret = 1;
 447                goto out;
 448        }
 449        ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
 450        if (!ret) {
 451                FILE *f;
 452
 453                if (utime(rerere_path(name, "postimage"), NULL) < 0)
 454                        warning("failed utime() on %s: %s",
 455                                        rerere_path(name, "postimage"),
 456                                        strerror(errno));
 457                f = fopen(path, "w");
 458                if (!f)
 459                        return error("Could not open %s: %s", path,
 460                                     strerror(errno));
 461                if (fwrite(result.ptr, result.size, 1, f) != 1)
 462                        error("Could not write %s: %s", path, strerror(errno));
 463                if (fclose(f))
 464                        return error("Writing %s failed: %s", path,
 465                                     strerror(errno));
 466        }
 467
 468out:
 469        free(cur.ptr);
 470        free(base.ptr);
 471        free(other.ptr);
 472        free(result.ptr);
 473
 474        return ret;
 475}
 476
 477static struct lock_file index_lock;
 478
 479static int update_paths(struct string_list *update)
 480{
 481        int i;
 482        int fd = hold_locked_index(&index_lock, 0);
 483        int status = 0;
 484
 485        if (fd < 0)
 486                return -1;
 487
 488        for (i = 0; i < update->nr; i++) {
 489                struct string_list_item *item = &update->items[i];
 490                if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS))
 491                        status = -1;
 492        }
 493
 494        if (!status && active_cache_changed) {
 495                if (write_cache(fd, active_cache, active_nr) ||
 496                    commit_locked_index(&index_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
 503static 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
 577static int git_rerere_config(const char *var, const char *value, void *cb)
 578{
 579        if (!strcmp(var, "rerere.enabled"))
 580                rerere_enabled = git_config_bool(var, value);
 581        else if (!strcmp(var, "rerere.autoupdate"))
 582                rerere_autoupdate = git_config_bool(var, value);
 583        else
 584                return git_default_config(var, value, cb);
 585        return 0;
 586}
 587
 588static int is_rerere_enabled(void)
 589{
 590        const char *rr_cache;
 591        int rr_cache_exists;
 592
 593        if (!rerere_enabled)
 594                return 0;
 595
 596        rr_cache = git_path("rr-cache");
 597        rr_cache_exists = is_directory(rr_cache);
 598        if (rerere_enabled < 0)
 599                return rr_cache_exists;
 600
 601        if (!rr_cache_exists && mkdir_in_gitdir(rr_cache))
 602                die("Could not create directory %s", rr_cache);
 603        return 1;
 604}
 605
 606int setup_rerere(struct string_list *merge_rr, int flags)
 607{
 608        int fd;
 609
 610        git_config(git_rerere_config, NULL);
 611        if (!is_rerere_enabled())
 612                return -1;
 613
 614        if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
 615                rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
 616        merge_rr_path = git_pathdup("MERGE_RR");
 617        fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
 618                                       LOCK_DIE_ON_ERROR);
 619        read_rr(merge_rr);
 620        return fd;
 621}
 622
 623int rerere(int flags)
 624{
 625        struct string_list merge_rr = STRING_LIST_INIT_DUP;
 626        int fd;
 627
 628        fd = setup_rerere(&merge_rr, flags);
 629        if (fd < 0)
 630                return 0;
 631        return do_plain_rerere(&merge_rr, fd);
 632}
 633
 634static int rerere_forget_one_path(const char *path, struct string_list *rr)
 635{
 636        const char *filename;
 637        char *hex;
 638        unsigned char sha1[20];
 639        int ret;
 640
 641        ret = handle_cache(path, sha1, NULL);
 642        if (ret < 1)
 643                return error("Could not parse conflict hunks in '%s'", path);
 644        hex = xstrdup(sha1_to_hex(sha1));
 645        filename = rerere_path(hex, "postimage");
 646        if (unlink(filename))
 647                return (errno == ENOENT
 648                        ? error("no remembered resolution for %s", path)
 649                        : error("cannot unlink %s: %s", filename, strerror(errno)));
 650
 651        handle_cache(path, sha1, rerere_path(hex, "preimage"));
 652        fprintf(stderr, "Updated preimage for '%s'\n", path);
 653
 654
 655        string_list_insert(rr, path)->util = hex;
 656        fprintf(stderr, "Forgot resolution for %s\n", path);
 657        return 0;
 658}
 659
 660int rerere_forget(struct pathspec *pathspec)
 661{
 662        int i, fd;
 663        struct string_list conflict = STRING_LIST_INIT_DUP;
 664        struct string_list merge_rr = STRING_LIST_INIT_DUP;
 665
 666        if (read_cache() < 0)
 667                return error("Could not read index");
 668
 669        fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
 670
 671        unmerge_cache(pathspec);
 672        find_conflict(&conflict);
 673        for (i = 0; i < conflict.nr; i++) {
 674                struct string_list_item *it = &conflict.items[i];
 675                if (!match_pathspec_depth(pathspec, it->string, strlen(it->string),
 676                                          0, NULL))
 677                        continue;
 678                rerere_forget_one_path(it->string, &merge_rr);
 679        }
 680        return write_rr(&merge_rr, fd);
 681}
 682
 683static time_t rerere_created_at(const char *name)
 684{
 685        struct stat st;
 686        return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
 687}
 688
 689static time_t rerere_last_used_at(const char *name)
 690{
 691        struct stat st;
 692        return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
 693}
 694
 695static void unlink_rr_item(const char *name)
 696{
 697        unlink(rerere_path(name, "thisimage"));
 698        unlink(rerere_path(name, "preimage"));
 699        unlink(rerere_path(name, "postimage"));
 700        rmdir(git_path("rr-cache/%s", name));
 701}
 702
 703struct rerere_gc_config_cb {
 704        int cutoff_noresolve;
 705        int cutoff_resolve;
 706};
 707
 708static int git_rerere_gc_config(const char *var, const char *value, void *cb)
 709{
 710        struct rerere_gc_config_cb *cf = cb;
 711
 712        if (!strcmp(var, "gc.rerereresolved"))
 713                cf->cutoff_resolve = git_config_int(var, value);
 714        else if (!strcmp(var, "gc.rerereunresolved"))
 715                cf->cutoff_noresolve = git_config_int(var, value);
 716        else
 717                return git_default_config(var, value, cb);
 718        return 0;
 719}
 720
 721void rerere_gc(struct string_list *rr)
 722{
 723        struct string_list to_remove = STRING_LIST_INIT_DUP;
 724        DIR *dir;
 725        struct dirent *e;
 726        int i, cutoff;
 727        time_t now = time(NULL), then;
 728        struct rerere_gc_config_cb cf = { 15, 60 };
 729
 730        git_config(git_rerere_gc_config, &cf);
 731        dir = opendir(git_path("rr-cache"));
 732        if (!dir)
 733                die_errno("unable to open rr-cache directory");
 734        while ((e = readdir(dir))) {
 735                if (is_dot_or_dotdot(e->d_name))
 736                        continue;
 737
 738                then = rerere_last_used_at(e->d_name);
 739                if (then) {
 740                        cutoff = cf.cutoff_resolve;
 741                } else {
 742                        then = rerere_created_at(e->d_name);
 743                        if (!then)
 744                                continue;
 745                        cutoff = cf.cutoff_noresolve;
 746                }
 747                if (then < now - cutoff * 86400)
 748                        string_list_append(&to_remove, e->d_name);
 749        }
 750        closedir(dir);
 751        for (i = 0; i < to_remove.nr; i++)
 752                unlink_rr_item(to_remove.items[i].string);
 753        string_list_clear(&to_remove, 0);
 754}
 755
 756void rerere_clear(struct string_list *merge_rr)
 757{
 758        int i;
 759
 760        for (i = 0; i < merge_rr->nr; i++) {
 761                const char *name = (const char *)merge_rr->items[i].util;
 762                if (!has_rerere_resolution(name))
 763                        unlink_rr_item(name);
 764        }
 765        unlink_or_warn(git_path("MERGE_RR"));
 766}