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 (!strncmp("<<<<<<< ", buf, 8))
 116                        hunk = 1;
 117                else if (!strncmp("=======", buf, 7))
 118                        hunk = 2;
 119                else if (!strncmp(">>>>>>> ", buf, 8)) {
 120                        hunk_no++;
 121                        hunk = 0;
 122                        if (memcmp(one->ptr, two->ptr, one->nr < two->nr ?
 123                                                one->nr : two->nr) > 0) {
 124                                struct buffer *swap = one;
 125                                one = two;
 126                                two = swap;
 127                        }
 128                        if (out) {
 129                                fputs("<<<<<<<\n", out);
 130                                fwrite(one->ptr, one->nr, 1, out);
 131                                fputs("=======\n", out);
 132                                fwrite(two->ptr, two->nr, 1, out);
 133                                fputs(">>>>>>>\n", out);
 134                        }
 135                        if (sha1) {
 136                                SHA1_Update(&ctx, one->ptr, one->nr);
 137                                SHA1_Update(&ctx, "\0", 1);
 138                                SHA1_Update(&ctx, two->ptr, two->nr);
 139                                SHA1_Update(&ctx, "\0", 1);
 140                        }
 141                        clear_buffer(one);
 142                        clear_buffer(two);
 143                } else if (hunk == 1)
 144                        append_line(one, buf);
 145                else if (hunk == 2)
 146                        append_line(two, buf);
 147                else if (out)
 148                        fputs(buf, out);
 149        }
 150
 151        fclose(f);
 152        if (out)
 153                fclose(out);
 154        if (sha1)
 155                SHA1_Final(sha1, &ctx);
 156        return hunk_no;
 157}
 158
 159static int find_conflict(struct path_list *conflict)
 160{
 161        int i;
 162        if (read_cache() < 0)
 163                return error("Could not read index");
 164        for (i = 0; i + 2 < active_nr; i++) {
 165                struct cache_entry *e1 = active_cache[i];
 166                struct cache_entry *e2 = active_cache[i+1];
 167                struct cache_entry *e3 = active_cache[i+2];
 168                if (ce_stage(e1) == 1 &&
 169                    ce_stage(e2) == 2 &&
 170                    ce_stage(e3) == 3 &&
 171                    ce_same_name(e1, e2) && ce_same_name(e1, e3) &&
 172                    S_ISREG(ntohl(e1->ce_mode)) &&
 173                    S_ISREG(ntohl(e2->ce_mode)) &&
 174                    S_ISREG(ntohl(e3->ce_mode))) {
 175                        path_list_insert((const char *)e1->name, conflict);
 176                        i += 2;
 177                }
 178        }
 179        return 0;
 180}
 181
 182static int merge(const char *name, const char *path)
 183{
 184        int ret;
 185        mmfile_t cur, base, other;
 186        mmbuffer_t result = {NULL, 0};
 187        xpparam_t xpp = {XDF_NEED_MINIMAL};
 188
 189        if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
 190                return 1;
 191
 192        if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
 193                        read_mmfile(&base, rr_path(name, "preimage")) ||
 194                        read_mmfile(&other, rr_path(name, "postimage")))
 195                return 1;
 196        ret = xdl_merge(&base, &cur, "", &other, "",
 197                        &xpp, XDL_MERGE_ZEALOUS, &result);
 198        if (!ret) {
 199                FILE *f = fopen(path, "w");
 200                if (!f)
 201                        return error("Could not write to %s", path);
 202                fwrite(result.ptr, result.size, 1, f);
 203                fclose(f);
 204        }
 205
 206        free(cur.ptr);
 207        free(base.ptr);
 208        free(other.ptr);
 209        free(result.ptr);
 210
 211        return ret;
 212}
 213
 214static void unlink_rr_item(const char *name)
 215{
 216        unlink(rr_path(name, "thisimage"));
 217        unlink(rr_path(name, "preimage"));
 218        unlink(rr_path(name, "postimage"));
 219        rmdir(git_path("rr-cache/%s", name));
 220}
 221
 222static void garbage_collect(struct path_list *rr)
 223{
 224        struct path_list to_remove = { NULL, 0, 0, 1 };
 225        char buf[1024];
 226        DIR *dir;
 227        struct dirent *e;
 228        int len, i, cutoff;
 229        time_t now = time(NULL), then;
 230
 231        strlcpy(buf, git_path("rr-cache"), sizeof(buf));
 232        len = strlen(buf);
 233        dir = opendir(buf);
 234        strcpy(buf + len++, "/");
 235        while ((e = readdir(dir))) {
 236                const char *name = e->d_name;
 237                struct stat st;
 238                if (name[0] == '.' && (name[1] == '\0' ||
 239                                        (name[1] == '.' && name[2] == '\0')))
 240                        continue;
 241                i = snprintf(buf + len, sizeof(buf) - len, "%s", name);
 242                strlcpy(buf + len + i, "/preimage", sizeof(buf) - len - i);
 243                if (stat(buf, &st))
 244                        continue;
 245                then = st.st_mtime;
 246                strlcpy(buf + len + i, "/postimage", sizeof(buf) - len - i);
 247                cutoff = stat(buf, &st) ? cutoff_noresolve : cutoff_resolve;
 248                if (then < now - cutoff * 86400) {
 249                        buf[len + i] = '\0';
 250                        path_list_insert(xstrdup(name), &to_remove);
 251                }
 252        }
 253        for (i = 0; i < to_remove.nr; i++)
 254                unlink_rr_item(to_remove.items[i].path);
 255        path_list_clear(&to_remove, 0);
 256}
 257
 258static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
 259{
 260        int i;
 261        for (i = 0; i < nbuf; i++)
 262                if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
 263                        return -1;
 264        return 0;
 265}
 266
 267static int diff_two(const char *file1, const char *label1,
 268                const char *file2, const char *label2)
 269{
 270        xpparam_t xpp;
 271        xdemitconf_t xecfg;
 272        xdemitcb_t ecb;
 273        mmfile_t minus, plus;
 274
 275        if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
 276                return 1;
 277
 278        printf("--- a/%s\n+++ b/%s\n", label1, label2);
 279        fflush(stdout);
 280        xpp.flags = XDF_NEED_MINIMAL;
 281        xecfg.ctxlen = 3;
 282        xecfg.flags = 0;
 283        ecb.outf = outf;
 284        xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 285
 286        free(minus.ptr);
 287        free(plus.ptr);
 288        return 0;
 289}
 290
 291static int copy_file(const char *src, const char *dest)
 292{
 293        FILE *in, *out;
 294        char buffer[32768];
 295        int count;
 296
 297        if (!(in = fopen(src, "r")))
 298                return error("Could not open %s", src);
 299        if (!(out = fopen(dest, "w")))
 300                return error("Could not open %s", dest);
 301        while ((count = fread(buffer, 1, sizeof(buffer), in)))
 302                fwrite(buffer, 1, count, out);
 303        fclose(in);
 304        fclose(out);
 305        return 0;
 306}
 307
 308static int do_plain_rerere(struct path_list *rr, int fd)
 309{
 310        struct path_list conflict = { NULL, 0, 0, 1 };
 311        int i;
 312
 313        find_conflict(&conflict);
 314
 315        /*
 316         * MERGE_RR records paths with conflicts immediately after merge
 317         * failed.  Some of the conflicted paths might have been hand resolved
 318         * in the working tree since then, but the initial run would catch all
 319         * and register their preimages.
 320         */
 321
 322        for (i = 0; i < conflict.nr; i++) {
 323                const char *path = conflict.items[i].path;
 324                if (!path_list_has_path(rr, path)) {
 325                        unsigned char sha1[20];
 326                        char *hex;
 327                        int ret;
 328                        ret = handle_file(path, sha1, NULL);
 329                        if (ret < 1)
 330                                continue;
 331                        hex = xstrdup(sha1_to_hex(sha1));
 332                        path_list_insert(path, rr)->util = hex;
 333                        if (mkdir(git_path("rr-cache/%s", hex), 0755))
 334                                continue;;
 335                        handle_file(path, NULL, rr_path(hex, "preimage"));
 336                        fprintf(stderr, "Recorded preimage for '%s'\n", path);
 337                }
 338        }
 339
 340        /*
 341         * Now some of the paths that had conflicts earlier might have been
 342         * hand resolved.  Others may be similar to a conflict already that
 343         * was resolved before.
 344         */
 345
 346        for (i = 0; i < rr->nr; i++) {
 347                struct stat st;
 348                int ret;
 349                const char *path = rr->items[i].path;
 350                const char *name = (const char *)rr->items[i].util;
 351
 352                if (!stat(rr_path(name, "preimage"), &st) &&
 353                                !stat(rr_path(name, "postimage"), &st)) {
 354                        if (!merge(name, path)) {
 355                                fprintf(stderr, "Resolved '%s' using "
 356                                                "previous resolution.\n", path);
 357                                goto tail_optimization;
 358                        }
 359                }
 360
 361                /* Let's see if we have resolved it. */
 362                ret = handle_file(path, NULL, NULL);
 363                if (ret)
 364                        continue;
 365
 366                fprintf(stderr, "Recorded resolution for '%s'.\n", path);
 367                copy_file(path, rr_path(name, "postimage"));
 368tail_optimization:
 369                if (i < rr->nr - 1)
 370                        memmove(rr->items + i,
 371                                rr->items + i + 1,
 372                                sizeof(rr->items[0]) * (rr->nr - i - 1));
 373                rr->nr--;
 374                i--;
 375        }
 376
 377        return write_rr(rr, fd);
 378}
 379
 380static int git_rerere_config(const char *var, const char *value)
 381{
 382        if (!strcmp(var, "gc.rerereresolved"))
 383                cutoff_resolve = git_config_int(var, value);
 384        else if (!strcmp(var, "gc.rerereunresolved"))
 385                cutoff_noresolve = git_config_int(var, value);
 386        else
 387                return git_default_config(var, value);
 388        return 0;
 389}
 390
 391int cmd_rerere(int argc, const char **argv, const char *prefix)
 392{
 393        struct path_list merge_rr = { NULL, 0, 0, 1 };
 394        int i, fd = -1;
 395        struct stat st;
 396
 397        if (stat(git_path("rr-cache"), &st) || !S_ISDIR(st.st_mode))
 398                return 0;
 399
 400        git_config(git_rerere_config);
 401
 402        merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
 403        fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
 404        read_rr(&merge_rr);
 405
 406        if (argc < 2)
 407                return do_plain_rerere(&merge_rr, fd);
 408        else if (!strcmp(argv[1], "clear")) {
 409                for (i = 0; i < merge_rr.nr; i++) {
 410                        const char *name = (const char *)merge_rr.items[i].util;
 411                        if (!stat(git_path("rr-cache/%s", name), &st) &&
 412                                        S_ISDIR(st.st_mode) &&
 413                                        stat(rr_path(name, "postimage"), &st))
 414                                unlink_rr_item(name);
 415                }
 416                unlink(merge_rr_path);
 417        } else if (!strcmp(argv[1], "gc"))
 418                garbage_collect(&merge_rr);
 419        else if (!strcmp(argv[1], "status"))
 420                for (i = 0; i < merge_rr.nr; i++)
 421                        printf("%s\n", merge_rr.items[i].path);
 422        else if (!strcmp(argv[1], "diff"))
 423                for (i = 0; i < merge_rr.nr; i++) {
 424                        const char *path = merge_rr.items[i].path;
 425                        const char *name = (const char *)merge_rr.items[i].util;
 426                        diff_two(rr_path(name, "preimage"), path, path, path);
 427                }
 428        else
 429                usage(git_rerere_usage);
 430
 431        path_list_clear(&merge_rr, 1);
 432        return 0;
 433}
 434