Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "path-list.h"
   3#include "xdiff/xdiff.h"
   4#include "xdiff-interface.h"
   5
   6#include <time.h>
   7
   8static const char git_rerere_usage[] =
   9"git-rerere [clear | status | diff | gc]";
  10
  11/* these values are days */
  12static int cutoff_noresolve = 15;
  13static int cutoff_resolve = 60;
  14
  15static char *merge_rr_path;
  16
  17static const char *rr_path(const char *name, const char *file)
  18{
  19        return git_path("rr-cache/%s/%s", name, file);
  20}
  21
  22static void read_rr(struct path_list *rr)
  23{
  24        unsigned char sha1[20];
  25        char buf[PATH_MAX];
  26        FILE *in = fopen(merge_rr_path, "r");
  27        if (!in)
  28                return;
  29        while (fread(buf, 40, 1, in) == 1) {
  30                int i;
  31                char *name;
  32                if (get_sha1_hex(buf, sha1))
  33                        die("corrupt MERGE_RR");
  34                buf[40] = '\0';
  35                name = xstrdup(buf);
  36                if (fgetc(in) != '\t')
  37                        die("corrupt MERGE_RR");
  38                for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
  39                        ; /* do nothing */
  40                if (i == sizeof(buf))
  41                        die("filename too long");
  42                path_list_insert(buf, rr)->util = xstrdup(name);
  43        }
  44        fclose(in);
  45}
  46
  47static struct lock_file write_lock;
  48
  49static int write_rr(struct path_list *rr, int out_fd)
  50{
  51        int i;
  52        for (i = 0; i < rr->nr; i++) {
  53                const char *path = rr->items[i].path;
  54                int length = strlen(path) + 1;
  55                if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
  56                    write_in_full(out_fd, "\t", 1) != 1 ||
  57                    write_in_full(out_fd, path, length) != length)
  58                        die("unable to write rerere record");
  59        }
  60        close(out_fd);
  61        return commit_lock_file(&write_lock);
  62}
  63
  64struct buffer {
  65        char *ptr;
  66        int nr, alloc;
  67};
  68
  69static void append_line(struct buffer *buffer, const char *line)
  70{
  71        int len = strlen(line);
  72
  73        if (buffer->nr + len > buffer->alloc) {
  74                buffer->alloc = alloc_nr(buffer->nr + len);
  75                buffer->ptr = xrealloc(buffer->ptr, buffer->alloc);
  76        }
  77        memcpy(buffer->ptr + buffer->nr, line, len);
  78        buffer->nr += len;
  79}
  80
  81static void clear_buffer(struct buffer *buffer)
  82{
  83        free(buffer->ptr);
  84        buffer->ptr = NULL;
  85        buffer->nr = buffer->alloc = 0;
  86}
  87
  88static int handle_file(const char *path,
  89         unsigned char *sha1, const char *output)
  90{
  91        SHA_CTX ctx;
  92        char buf[1024];
  93        int hunk = 0, hunk_no = 0;
  94        struct buffer minus = { NULL, 0, 0 }, plus = { NULL, 0, 0 };
  95        struct buffer *one = &minus, *two = &plus;
  96        FILE *f = fopen(path, "r");
  97        FILE *out;
  98
  99        if (!f)
 100                return error("Could not open %s", path);
 101
 102        if (output) {
 103                out = fopen(output, "w");
 104                if (!out) {
 105                        fclose(f);
 106                        return error("Could not write %s", output);
 107                }
 108        } else
 109                out = NULL;
 110
 111        if (sha1)
 112                SHA1_Init(&ctx);
 113
 114        while (fgets(buf, sizeof(buf), f)) {
 115                if (!prefixcmp(buf, "<<<<<<< "))
 116                        hunk = 1;
 117                else if (!prefixcmp(buf, "======="))
 118                        hunk = 2;
 119                else if (!prefixcmp(buf, ">>>>>>> ")) {
 120                        int one_is_longer = (one->nr > two->nr);
 121                        int common_len = one_is_longer ? two->nr : one->nr;
 122                        int cmp = memcmp(one->ptr, two->ptr, common_len);
 123
 124                        hunk_no++;
 125                        hunk = 0;
 126                        if ((cmp > 0) || ((cmp == 0) && one_is_longer)) {
 127                                struct buffer *swap = one;
 128                                one = two;
 129                                two = swap;
 130                        }
 131                        if (out) {
 132                                fputs("<<<<<<<\n", out);
 133                                fwrite(one->ptr, one->nr, 1, out);
 134                                fputs("=======\n", out);
 135                                fwrite(two->ptr, two->nr, 1, out);
 136                                fputs(">>>>>>>\n", out);
 137                        }
 138                        if (sha1) {
 139                                SHA1_Update(&ctx, one->ptr, one->nr);
 140                                SHA1_Update(&ctx, "\0", 1);
 141                                SHA1_Update(&ctx, two->ptr, two->nr);
 142                                SHA1_Update(&ctx, "\0", 1);
 143                        }
 144                        clear_buffer(one);
 145                        clear_buffer(two);
 146                } else if (hunk == 1)
 147                        append_line(one, buf);
 148                else if (hunk == 2)
 149                        append_line(two, buf);
 150                else if (out)
 151                        fputs(buf, out);
 152        }
 153
 154        fclose(f);
 155        if (out)
 156                fclose(out);
 157        if (sha1)
 158                SHA1_Final(sha1, &ctx);
 159        return hunk_no;
 160}
 161
 162static int find_conflict(struct path_list *conflict)
 163{
 164        int i;
 165        if (read_cache() < 0)
 166                return error("Could not read index");
 167        for (i = 0; i + 2 < active_nr; i++) {
 168                struct cache_entry *e1 = active_cache[i];
 169                struct cache_entry *e2 = active_cache[i+1];
 170                struct cache_entry *e3 = active_cache[i+2];
 171                if (ce_stage(e1) == 1 &&
 172                    ce_stage(e2) == 2 &&
 173                    ce_stage(e3) == 3 &&
 174                    ce_same_name(e1, e2) && ce_same_name(e1, e3) &&
 175                    S_ISREG(ntohl(e1->ce_mode)) &&
 176                    S_ISREG(ntohl(e2->ce_mode)) &&
 177                    S_ISREG(ntohl(e3->ce_mode))) {
 178                        path_list_insert((const char *)e1->name, conflict);
 179                        i += 2;
 180                }
 181        }
 182        return 0;
 183}
 184
 185static int merge(const char *name, const char *path)
 186{
 187        int ret;
 188        mmfile_t cur, base, other;
 189        mmbuffer_t result = {NULL, 0};
 190        xpparam_t xpp = {XDF_NEED_MINIMAL};
 191
 192        if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
 193                return 1;
 194
 195        if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
 196                        read_mmfile(&base, rr_path(name, "preimage")) ||
 197                        read_mmfile(&other, rr_path(name, "postimage")))
 198                return 1;
 199        ret = xdl_merge(&base, &cur, "", &other, "",
 200                        &xpp, XDL_MERGE_ZEALOUS, &result);
 201        if (!ret) {
 202                FILE *f = fopen(path, "w");
 203                if (!f)
 204                        return error("Could not write to %s", path);
 205                fwrite(result.ptr, result.size, 1, f);
 206                fclose(f);
 207        }
 208
 209        free(cur.ptr);
 210        free(base.ptr);
 211        free(other.ptr);
 212        free(result.ptr);
 213
 214        return ret;
 215}
 216
 217static void unlink_rr_item(const char *name)
 218{
 219        unlink(rr_path(name, "thisimage"));
 220        unlink(rr_path(name, "preimage"));
 221        unlink(rr_path(name, "postimage"));
 222        rmdir(git_path("rr-cache/%s", name));
 223}
 224
 225static void garbage_collect(struct path_list *rr)
 226{
 227        struct path_list to_remove = { NULL, 0, 0, 1 };
 228        char buf[1024];
 229        DIR *dir;
 230        struct dirent *e;
 231        int len, i, cutoff;
 232        time_t now = time(NULL), then;
 233
 234        strlcpy(buf, git_path("rr-cache"), sizeof(buf));
 235        len = strlen(buf);
 236        dir = opendir(buf);
 237        strcpy(buf + len++, "/");
 238        while ((e = readdir(dir))) {
 239                const char *name = e->d_name;
 240                struct stat st;
 241                if (name[0] == '.' && (name[1] == '\0' ||
 242                                        (name[1] == '.' && name[2] == '\0')))
 243                        continue;
 244                i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
 245                strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
 246                if (stat(buf, &st))
 247                        continue;
 248                then = st.st_mtime;
 249                strlcpy(buf + len + i, "/postimage", sizeof(buf) - len - i);
 250                cutoff = stat(buf, &st) ? cutoff_noresolve : cutoff_resolve;
 251                if (then < now - cutoff * 86400) {
 252                        buf[len + i] = '\0';
 253                        path_list_insert(xstrdup(name), &to_remove);
 254                }
 255        }
 256        for (i = 0; i < to_remove.nr; i++)
 257                unlink_rr_item(to_remove.items[i].path);
 258        path_list_clear(&to_remove, 0);
 259}
 260
 261static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
 262{
 263        int i;
 264        for (i = 0; i < nbuf; i++)
 265                if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
 266                        return -1;
 267        return 0;
 268}
 269
 270static int diff_two(const char *file1, const char *label1,
 271                const char *file2, const char *label2)
 272{
 273        xpparam_t xpp;
 274        xdemitconf_t xecfg;
 275        xdemitcb_t ecb;
 276        mmfile_t minus, plus;
 277
 278        if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
 279                return 1;
 280
 281        printf("--- a/%s\n+++ b/%s\n", label1, label2);
 282        fflush(stdout);
 283        xpp.flags = XDF_NEED_MINIMAL;
 284        xecfg.ctxlen = 3;
 285        xecfg.flags = 0;
 286        ecb.outf = outf;
 287        xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 288
 289        free(minus.ptr);
 290        free(plus.ptr);
 291        return 0;
 292}
 293
 294static int copy_file(const char *src, const char *dest)
 295{
 296        FILE *in, *out;
 297        char buffer[32768];
 298        int count;
 299
 300        if (!(in = fopen(src, "r")))
 301                return error("Could not open %s", src);
 302        if (!(out = fopen(dest, "w")))
 303                return error("Could not open %s", dest);
 304        while ((count = fread(buffer, 1, sizeof(buffer), in)))
 305                fwrite(buffer, 1, count, out);
 306        fclose(in);
 307        fclose(out);
 308        return 0;
 309}
 310
 311static int do_plain_rerere(struct path_list *rr, int fd)
 312{
 313        struct path_list conflict = { NULL, 0, 0, 1 };
 314        int i;
 315
 316        find_conflict(&conflict);
 317
 318        /*
 319         * MERGE_RR records paths with conflicts immediately after merge
 320         * failed.  Some of the conflicted paths might have been hand resolved
 321         * in the working tree since then, but the initial run would catch all
 322         * and register their preimages.
 323         */
 324
 325        for (i = 0; i < conflict.nr; i++) {
 326                const char *path = conflict.items[i].path;
 327                if (!path_list_has_path(rr, path)) {
 328                        unsigned char sha1[20];
 329                        char *hex;
 330                        int ret;
 331                        ret = handle_file(path, sha1, NULL);
 332                        if (ret < 1)
 333                                continue;
 334                        hex = xstrdup(sha1_to_hex(sha1));
 335                        path_list_insert(path, rr)->util = hex;
 336                        if (mkdir(git_path("rr-cache/%s", hex), 0755))
 337                                continue;;
 338                        handle_file(path, NULL, rr_path(hex, "preimage"));
 339                        fprintf(stderr, "Recorded preimage for '%s'\n", path);
 340                }
 341        }
 342
 343        /*
 344         * Now some of the paths that had conflicts earlier might have been
 345         * hand resolved.  Others may be similar to a conflict already that
 346         * was resolved before.
 347         */
 348
 349        for (i = 0; i < rr->nr; i++) {
 350                struct stat st;
 351                int ret;
 352                const char *path = rr->items[i].path;
 353                const char *name = (const char *)rr->items[i].util;
 354
 355                if (!stat(rr_path(name, "preimage"), &st) &&
 356                                !stat(rr_path(name, "postimage"), &st)) {
 357                        if (!merge(name, path)) {
 358                                fprintf(stderr, "Resolved '%s' using "
 359                                                "previous resolution.\n", path);
 360                                goto tail_optimization;
 361                        }
 362                }
 363
 364                /* Let's see if we have resolved it. */
 365                ret = handle_file(path, NULL, NULL);
 366                if (ret)
 367                        continue;
 368
 369                fprintf(stderr, "Recorded resolution for '%s'.\n", path);
 370                copy_file(path, rr_path(name, "postimage"));
 371tail_optimization:
 372                if (i < rr->nr - 1)
 373                        memmove(rr->items + i,
 374                                rr->items + i + 1,
 375                                sizeof(rr->items[0]) * (rr->nr - i - 1));
 376                rr->nr--;
 377                i--;
 378        }
 379
 380        return write_rr(rr, fd);
 381}
 382
 383static int git_rerere_config(const char *var, const char *value)
 384{
 385        if (!strcmp(var, "gc.rerereresolved"))
 386                cutoff_resolve = git_config_int(var, value);
 387        else if (!strcmp(var, "gc.rerereunresolved"))
 388                cutoff_noresolve = git_config_int(var, value);
 389        else
 390                return git_default_config(var, value);
 391        return 0;
 392}
 393
 394int cmd_rerere(int argc, const char **argv, const char *prefix)
 395{
 396        struct path_list merge_rr = { NULL, 0, 0, 1 };
 397        int i, fd = -1;
 398        struct stat st;
 399
 400        if (stat(git_path("rr-cache"), &st) || !S_ISDIR(st.st_mode))
 401                return 0;
 402
 403        git_config(git_rerere_config);
 404
 405        merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
 406        fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
 407        read_rr(&merge_rr);
 408
 409        if (argc < 2)
 410                return do_plain_rerere(&merge_rr, fd);
 411        else if (!strcmp(argv[1], "clear")) {
 412                for (i = 0; i < merge_rr.nr; i++) {
 413                        const char *name = (const char *)merge_rr.items[i].util;
 414                        if (!stat(git_path("rr-cache/%s", name), &st) &&
 415                                        S_ISDIR(st.st_mode) &&
 416                                        stat(rr_path(name, "postimage"), &st))
 417                                unlink_rr_item(name);
 418                }
 419                unlink(merge_rr_path);
 420        } else if (!strcmp(argv[1], "gc"))
 421                garbage_collect(&merge_rr);
 422        else if (!strcmp(argv[1], "status"))
 423                for (i = 0; i < merge_rr.nr; i++)
 424                        printf("%s\n", merge_rr.items[i].path);
 425        else if (!strcmp(argv[1], "diff"))
 426                for (i = 0; i < merge_rr.nr; i++) {
 427                        const char *path = merge_rr.items[i].path;
 428                        const char *name = (const char *)merge_rr.items[i].util;
 429                        diff_two(rr_path(name, "preimage"), path, path, path);
 430                }
 431        else
 432                usage(git_rerere_usage);
 433
 434        path_list_clear(&merge_rr, 1);
 435        return 0;
 436}