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