Andrew's git / gitweb.git / rerere.c
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rerere.con commit Merge branch 'da/darwin' (9a7eaad)
   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
  28static int 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 = memchr(io->input.buf, '\n', io->input.len);
 288        if (!ep)
 289                ep = io->input.buf + io->input.len;
 290        else if (*ep == '\n')
 291                ep++;
 292        len = ep - io->input.buf;
 293        strbuf_add(sb, io->input.buf, len);
 294        strbuf_remove(&io->input, 0, len);
 295        return 0;
 296}
 297
 298static int handle_cache(const char *path, unsigned char *sha1, const char *output)
 299{
 300        mmfile_t mmfile[3] = {{NULL}};
 301        mmbuffer_t result = {NULL, 0};
 302        const struct cache_entry *ce;
 303        int pos, len, i, hunk_no;
 304        struct rerere_io_mem io;
 305        int marker_size = ll_merge_marker_size(path);
 306
 307        /*
 308         * Reproduce the conflicted merge in-core
 309         */
 310        len = strlen(path);
 311        pos = cache_name_pos(path, len);
 312        if (0 <= pos)
 313                return -1;
 314        pos = -pos - 1;
 315
 316        for (i = 0; i < 3; i++) {
 317                enum object_type type;
 318                unsigned long size;
 319                int j;
 320
 321                if (active_nr <= pos)
 322                        break;
 323                ce = active_cache[pos++];
 324                if (ce_namelen(ce) != len || memcmp(ce->name, path, len))
 325                        continue;
 326                j = ce_stage(ce) - 1;
 327                mmfile[j].ptr = read_sha1_file(ce->sha1, &type, &size);
 328                mmfile[j].size = size;
 329        }
 330        for (i = 0; i < 3; i++) {
 331                if (!mmfile[i].ptr && !mmfile[i].size)
 332                        mmfile[i].ptr = xstrdup("");
 333        }
 334        /*
 335         * NEEDSWORK: handle conflicts from merges with
 336         * merge.renormalize set, too
 337         */
 338        ll_merge(&result, path, &mmfile[0], NULL,
 339                 &mmfile[1], "ours",
 340                 &mmfile[2], "theirs", NULL);
 341        for (i = 0; i < 3; i++)
 342                free(mmfile[i].ptr);
 343
 344        memset(&io, 0, sizeof(io));
 345        io.io.getline = rerere_mem_getline;
 346        if (output)
 347                io.io.output = fopen(output, "w");
 348        else
 349                io.io.output = NULL;
 350        strbuf_init(&io.input, 0);
 351        strbuf_attach(&io.input, result.ptr, result.size, result.size);
 352
 353        hunk_no = handle_path(sha1, (struct rerere_io *)&io, marker_size);
 354        strbuf_release(&io.input);
 355        if (io.io.output)
 356                fclose(io.io.output);
 357        return hunk_no;
 358}
 359
 360static int check_one_conflict(int i, int *type)
 361{
 362        const struct cache_entry *e = active_cache[i];
 363
 364        if (!ce_stage(e)) {
 365                *type = RESOLVED;
 366                return i + 1;
 367        }
 368
 369        *type = PUNTED;
 370        if (ce_stage(e) == 1) {
 371                if (active_nr <= ++i)
 372                        return i + 1;
 373        }
 374
 375        /* Only handle regular files with both stages #2 and #3 */
 376        if (i + 1 < active_nr) {
 377                const struct cache_entry *e2 = active_cache[i];
 378                const struct cache_entry *e3 = active_cache[i + 1];
 379                if (ce_stage(e2) == 2 &&
 380                    ce_stage(e3) == 3 &&
 381                    ce_same_name(e, e3) &&
 382                    S_ISREG(e2->ce_mode) &&
 383                    S_ISREG(e3->ce_mode))
 384                        *type = THREE_STAGED;
 385        }
 386
 387        /* Skip the entries with the same name */
 388        while (i < active_nr && ce_same_name(e, active_cache[i]))
 389                i++;
 390        return i;
 391}
 392
 393static int find_conflict(struct string_list *conflict)
 394{
 395        int i;
 396        if (read_cache() < 0)
 397                return error("Could not read index");
 398
 399        for (i = 0; i < active_nr;) {
 400                int conflict_type;
 401                const struct cache_entry *e = active_cache[i];
 402                i = check_one_conflict(i, &conflict_type);
 403                if (conflict_type == THREE_STAGED)
 404                        string_list_insert(conflict, (const char *)e->name);
 405        }
 406        return 0;
 407}
 408
 409int rerere_remaining(struct string_list *merge_rr)
 410{
 411        int i;
 412        if (read_cache() < 0)
 413                return error("Could not read index");
 414
 415        for (i = 0; i < active_nr;) {
 416                int conflict_type;
 417                const struct cache_entry *e = active_cache[i];
 418                i = check_one_conflict(i, &conflict_type);
 419                if (conflict_type == PUNTED)
 420                        string_list_insert(merge_rr, (const char *)e->name);
 421                else if (conflict_type == RESOLVED) {
 422                        struct string_list_item *it;
 423                        it = string_list_lookup(merge_rr, (const char *)e->name);
 424                        if (it != NULL) {
 425                                free(it->util);
 426                                it->util = RERERE_RESOLVED;
 427                        }
 428                }
 429        }
 430        return 0;
 431}
 432
 433static int merge(const char *name, const char *path)
 434{
 435        int ret;
 436        mmfile_t cur = {NULL, 0}, base = {NULL, 0}, other = {NULL, 0};
 437        mmbuffer_t result = {NULL, 0};
 438
 439        if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
 440                return 1;
 441
 442        if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
 443                        read_mmfile(&base, rerere_path(name, "preimage")) ||
 444                        read_mmfile(&other, rerere_path(name, "postimage"))) {
 445                ret = 1;
 446                goto out;
 447        }
 448        ret = ll_merge(&result, path, &base, NULL, &cur, "", &other, "", NULL);
 449        if (!ret) {
 450                FILE *f;
 451
 452                if (utime(rerere_path(name, "postimage"), NULL) < 0)
 453                        warning("failed utime() on %s: %s",
 454                                        rerere_path(name, "postimage"),
 455                                        strerror(errno));
 456                f = fopen(path, "w");
 457                if (!f)
 458                        return error("Could not open %s: %s", path,
 459                                     strerror(errno));
 460                if (fwrite(result.ptr, result.size, 1, f) != 1)
 461                        error("Could not write %s: %s", path, strerror(errno));
 462                if (fclose(f))
 463                        return error("Writing %s failed: %s", path,
 464                                     strerror(errno));
 465        }
 466
 467out:
 468        free(cur.ptr);
 469        free(base.ptr);
 470        free(other.ptr);
 471        free(result.ptr);
 472
 473        return ret;
 474}
 475
 476static struct lock_file index_lock;
 477
 478static int update_paths(struct string_list *update)
 479{
 480        int i;
 481        int fd = hold_locked_index(&index_lock, 0);
 482        int status = 0;
 483
 484        if (fd < 0)
 485                return -1;
 486
 487        for (i = 0; i < update->nr; i++) {
 488                struct string_list_item *item = &update->items[i];
 489                if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS))
 490                        status = -1;
 491        }
 492
 493        if (!status && active_cache_changed) {
 494                if (write_cache(fd, active_cache, active_nr) ||
 495                    commit_locked_index(&index_lock))
 496                        die("Unable to write new index file");
 497        } else if (fd >= 0)
 498                rollback_lock_file(&index_lock);
 499        return status;
 500}
 501
 502static int do_plain_rerere(struct string_list *rr, int fd)
 503{
 504        struct string_list conflict = STRING_LIST_INIT_DUP;
 505        struct string_list update = STRING_LIST_INIT_DUP;
 506        int i;
 507
 508        find_conflict(&conflict);
 509
 510        /*
 511         * MERGE_RR records paths with conflicts immediately after merge
 512         * failed.  Some of the conflicted paths might have been hand resolved
 513         * in the working tree since then, but the initial run would catch all
 514         * and register their preimages.
 515         */
 516
 517        for (i = 0; i < conflict.nr; i++) {
 518                const char *path = conflict.items[i].string;
 519                if (!string_list_has_string(rr, path)) {
 520                        unsigned char sha1[20];
 521                        char *hex;
 522                        int ret;
 523                        ret = handle_file(path, sha1, NULL);
 524                        if (ret < 1)
 525                                continue;
 526                        hex = xstrdup(sha1_to_hex(sha1));
 527                        string_list_insert(rr, path)->util = hex;
 528                        if (mkdir_in_gitdir(git_path("rr-cache/%s", hex)))
 529                                continue;
 530                        handle_file(path, NULL, rerere_path(hex, "preimage"));
 531                        fprintf(stderr, "Recorded preimage for '%s'\n", path);
 532                }
 533        }
 534
 535        /*
 536         * Now some of the paths that had conflicts earlier might have been
 537         * hand resolved.  Others may be similar to a conflict already that
 538         * was resolved before.
 539         */
 540
 541        for (i = 0; i < rr->nr; i++) {
 542                int ret;
 543                const char *path = rr->items[i].string;
 544                const char *name = (const char *)rr->items[i].util;
 545
 546                if (has_rerere_resolution(name)) {
 547                        if (!merge(name, path)) {
 548                                const char *msg;
 549                                if (rerere_autoupdate) {
 550                                        string_list_insert(&update, path);
 551                                        msg = "Staged '%s' using previous resolution.\n";
 552                                } else
 553                                        msg = "Resolved '%s' using previous resolution.\n";
 554                                fprintf(stderr, msg, path);
 555                                goto mark_resolved;
 556                        }
 557                }
 558
 559                /* Let's see if we have resolved it. */
 560                ret = handle_file(path, NULL, NULL);
 561                if (ret)
 562                        continue;
 563
 564                fprintf(stderr, "Recorded resolution for '%s'.\n", path);
 565                copy_file(rerere_path(name, "postimage"), path, 0666);
 566        mark_resolved:
 567                rr->items[i].util = NULL;
 568        }
 569
 570        if (update.nr)
 571                update_paths(&update);
 572
 573        return write_rr(rr, fd);
 574}
 575
 576static int git_rerere_config(const char *var, const char *value, void *cb)
 577{
 578        if (!strcmp(var, "rerere.enabled"))
 579                rerere_enabled = git_config_bool(var, value);
 580        else if (!strcmp(var, "rerere.autoupdate"))
 581                rerere_autoupdate = git_config_bool(var, value);
 582        else
 583                return git_default_config(var, value, cb);
 584        return 0;
 585}
 586
 587static int is_rerere_enabled(void)
 588{
 589        const char *rr_cache;
 590        int rr_cache_exists;
 591
 592        if (!rerere_enabled)
 593                return 0;
 594
 595        rr_cache = git_path("rr-cache");
 596        rr_cache_exists = is_directory(rr_cache);
 597        if (rerere_enabled < 0)
 598                return rr_cache_exists;
 599
 600        if (!rr_cache_exists && mkdir_in_gitdir(rr_cache))
 601                die("Could not create directory %s", rr_cache);
 602        return 1;
 603}
 604
 605int setup_rerere(struct string_list *merge_rr, int flags)
 606{
 607        int fd;
 608
 609        git_config(git_rerere_config, NULL);
 610        if (!is_rerere_enabled())
 611                return -1;
 612
 613        if (flags & (RERERE_AUTOUPDATE|RERERE_NOAUTOUPDATE))
 614                rerere_autoupdate = !!(flags & RERERE_AUTOUPDATE);
 615        merge_rr_path = git_pathdup("MERGE_RR");
 616        fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
 617                                       LOCK_DIE_ON_ERROR);
 618        read_rr(merge_rr);
 619        return fd;
 620}
 621
 622int rerere(int flags)
 623{
 624        struct string_list merge_rr = STRING_LIST_INIT_DUP;
 625        int fd;
 626
 627        fd = setup_rerere(&merge_rr, flags);
 628        if (fd < 0)
 629                return 0;
 630        return do_plain_rerere(&merge_rr, fd);
 631}
 632
 633static int rerere_forget_one_path(const char *path, struct string_list *rr)
 634{
 635        const char *filename;
 636        char *hex;
 637        unsigned char sha1[20];
 638        int ret;
 639
 640        ret = handle_cache(path, sha1, NULL);
 641        if (ret < 1)
 642                return error("Could not parse conflict hunks in '%s'", path);
 643        hex = xstrdup(sha1_to_hex(sha1));
 644        filename = rerere_path(hex, "postimage");
 645        if (unlink(filename))
 646                return (errno == ENOENT
 647                        ? error("no remembered resolution for %s", path)
 648                        : error("cannot unlink %s: %s", filename, strerror(errno)));
 649
 650        handle_cache(path, sha1, rerere_path(hex, "preimage"));
 651        fprintf(stderr, "Updated preimage for '%s'\n", path);
 652
 653
 654        string_list_insert(rr, path)->util = hex;
 655        fprintf(stderr, "Forgot resolution for %s\n", path);
 656        return 0;
 657}
 658
 659int rerere_forget(const char **pathspec)
 660{
 661        int i, fd;
 662        struct string_list conflict = STRING_LIST_INIT_DUP;
 663        struct string_list merge_rr = STRING_LIST_INIT_DUP;
 664
 665        if (read_cache() < 0)
 666                return error("Could not read index");
 667
 668        fd = setup_rerere(&merge_rr, RERERE_NOAUTOUPDATE);
 669
 670        unmerge_cache(pathspec);
 671        find_conflict(&conflict);
 672        for (i = 0; i < conflict.nr; i++) {
 673                struct string_list_item *it = &conflict.items[i];
 674                if (!match_pathspec(pathspec, it->string, strlen(it->string),
 675                                    0, NULL))
 676                        continue;
 677                rerere_forget_one_path(it->string, &merge_rr);
 678        }
 679        return write_rr(&merge_rr, fd);
 680}
 681
 682static time_t rerere_created_at(const char *name)
 683{
 684        struct stat st;
 685        return stat(rerere_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
 686}
 687
 688static time_t rerere_last_used_at(const char *name)
 689{
 690        struct stat st;
 691        return stat(rerere_path(name, "postimage"), &st) ? (time_t) 0 : st.st_mtime;
 692}
 693
 694static void unlink_rr_item(const char *name)
 695{
 696        unlink(rerere_path(name, "thisimage"));
 697        unlink(rerere_path(name, "preimage"));
 698        unlink(rerere_path(name, "postimage"));
 699        rmdir(git_path("rr-cache/%s", name));
 700}
 701
 702struct rerere_gc_config_cb {
 703        int cutoff_noresolve;
 704        int cutoff_resolve;
 705};
 706
 707static int git_rerere_gc_config(const char *var, const char *value, void *cb)
 708{
 709        struct rerere_gc_config_cb *cf = cb;
 710
 711        if (!strcmp(var, "gc.rerereresolved"))
 712                cf->cutoff_resolve = git_config_int(var, value);
 713        else if (!strcmp(var, "gc.rerereunresolved"))
 714                cf->cutoff_noresolve = git_config_int(var, value);
 715        else
 716                return git_default_config(var, value, cb);
 717        return 0;
 718}
 719
 720void rerere_gc(struct string_list *rr)
 721{
 722        struct string_list to_remove = STRING_LIST_INIT_DUP;
 723        DIR *dir;
 724        struct dirent *e;
 725        int i, cutoff;
 726        time_t now = time(NULL), then;
 727        struct rerere_gc_config_cb cf = { 15, 60 };
 728
 729        git_config(git_rerere_gc_config, &cf);
 730        dir = opendir(git_path("rr-cache"));
 731        if (!dir)
 732                die_errno("unable to open rr-cache directory");
 733        while ((e = readdir(dir))) {
 734                if (is_dot_or_dotdot(e->d_name))
 735                        continue;
 736
 737                then = rerere_last_used_at(e->d_name);
 738                if (then) {
 739                        cutoff = cf.cutoff_resolve;
 740                } else {
 741                        then = rerere_created_at(e->d_name);
 742                        if (!then)
 743                                continue;
 744                        cutoff = cf.cutoff_noresolve;
 745                }
 746                if (then < now - cutoff * 86400)
 747                        string_list_append(&to_remove, e->d_name);
 748        }
 749        closedir(dir);
 750        for (i = 0; i < to_remove.nr; i++)
 751                unlink_rr_item(to_remove.items[i].string);
 752        string_list_clear(&to_remove, 0);
 753}
 754
 755void rerere_clear(struct string_list *merge_rr)
 756{
 757        int i;
 758
 759        for (i = 0; i < merge_rr->nr; i++) {
 760                const char *name = (const char *)merge_rr->items[i].util;
 761                if (!has_rerere_resolution(name))
 762                        unlink_rr_item(name);
 763        }
 764        unlink_or_warn(git_path("MERGE_RR"));
 765}