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