Andrew's git - gitweb.git/blob

0eec1f937321024187c185226764c39f6534017a
   1#include "builtin.h"
   2#include "cache.h"
   3#include "path-list.h"
   4#include "xdiff/xdiff.h"
   5#include "xdiff-interface.h"
   6
   7#include <time.h>
   8
   9static const char git_rerere_usage[] =
  10"git-rerere [clear | status | diff | gc]";
  11
  12/* these values are days */
  13static int cutoff_noresolve = 15;
  14static int cutoff_resolve = 60;
  15
  16/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
  17static int rerere_enabled = -1;
  18
  19static char *merge_rr_path;
  20
  21static const char *rr_path(const char *name, const char *file)
  22{
  23        return git_path("rr-cache/%s/%s", name, file);
  24}
  25
  26static time_t rerere_created_at(const char *name)
  27{
  28        struct stat st;
  29        return stat(rr_path(name, "preimage"), &st) ? (time_t) 0 : st.st_mtime;
  30}
  31
  32static int has_resolution(const char *name)
  33{
  34        struct stat st;
  35        return !stat(rr_path(name, "postimage"), &st);
  36}
  37
  38static void read_rr(struct path_list *rr)
  39{
  40        unsigned char sha1[20];
  41        char buf[PATH_MAX];
  42        FILE *in = fopen(merge_rr_path, "r");
  43        if (!in)
  44                return;
  45        while (fread(buf, 40, 1, in) == 1) {
  46                int i;
  47                char *name;
  48                if (get_sha1_hex(buf, sha1))
  49                        die("corrupt MERGE_RR");
  50                buf[40] = '\0';
  51                name = xstrdup(buf);
  52                if (fgetc(in) != '\t')
  53                        die("corrupt MERGE_RR");
  54                for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
  55                        ; /* do nothing */
  56                if (i == sizeof(buf))
  57                        die("filename too long");
  58                path_list_insert(buf, rr)->util = name;
  59        }
  60        fclose(in);
  61}
  62
  63static struct lock_file write_lock;
  64
  65static int write_rr(struct path_list *rr, int out_fd)
  66{
  67        int i;
  68        for (i = 0; i < rr->nr; i++) {
  69                const char *path;
  70                int length;
  71                if (!rr->items[i].util)
  72                        continue;
  73                path = rr->items[i].path;
  74                length = strlen(path) + 1;
  75                if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
  76                    write_in_full(out_fd, "\t", 1) != 1 ||
  77                    write_in_full(out_fd, path, length) != length)
  78                        die("unable to write rerere record");
  79        }
  80        if (commit_lock_file(&write_lock) != 0)
  81                die("unable to write rerere record");
  82        return 0;
  83}
  84
  85static int handle_file(const char *path,
  86         unsigned char *sha1, const char *output)
  87{
  88        SHA_CTX ctx;
  89        char buf[1024];
  90        int hunk = 0, hunk_no = 0;
  91        struct strbuf one, two;
  92        FILE *f = fopen(path, "r");
  93        FILE *out = NULL;
  94
  95        if (!f)
  96                return error("Could not open %s", path);
  97
  98        if (output) {
  99                out = fopen(output, "w");
 100                if (!out) {
 101                        fclose(f);
 102                        return error("Could not write %s", output);
 103                }
 104        }
 105
 106        if (sha1)
 107                SHA1_Init(&ctx);
 108
 109        strbuf_init(&one, 0);
 110        strbuf_init(&two,  0);
 111        while (fgets(buf, sizeof(buf), f)) {
 112                if (!prefixcmp(buf, "<<<<<<< "))
 113                        hunk = 1;
 114                else if (!prefixcmp(buf, "======="))
 115                        hunk = 2;
 116                else if (!prefixcmp(buf, ">>>>>>> ")) {
 117                        if (strbuf_cmp(&one, &two) > 0)
 118                                strbuf_swap(&one, &two);
 119                        hunk_no++;
 120                        hunk = 0;
 121                        if (out) {
 122                                fputs("<<<<<<<\n", out);
 123                                fwrite(one.buf, one.len, 1, out);
 124                                fputs("=======\n", out);
 125                                fwrite(two.buf, two.len, 1, out);
 126                                fputs(">>>>>>>\n", out);
 127                        }
 128                        if (sha1) {
 129                                SHA1_Update(&ctx, one.buf ? one.buf : "",
 130                                            one.len + 1);
 131                                SHA1_Update(&ctx, two.buf ? two.buf : "",
 132                                            two.len + 1);
 133                        }
 134                        strbuf_reset(&one);
 135                        strbuf_reset(&two);
 136                } else if (hunk == 1)
 137                        strbuf_addstr(&one, buf);
 138                else if (hunk == 2)
 139                        strbuf_addstr(&two, buf);
 140                else if (out)
 141                        fputs(buf, out);
 142        }
 143        strbuf_release(&one);
 144        strbuf_release(&two);
 145
 146        fclose(f);
 147        if (out)
 148                fclose(out);
 149        if (sha1)
 150                SHA1_Final(sha1, &ctx);
 151        if (hunk) {
 152                if (output)
 153                        unlink(output);
 154                return error("Could not parse conflict hunks in %s", path);
 155        }
 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+1 < active_nr; i++) {
 165                struct cache_entry *e2 = active_cache[i];
 166                struct cache_entry *e3 = active_cache[i+1];
 167                if (ce_stage(e2) == 2 &&
 168                    ce_stage(e3) == 3 &&
 169                    ce_same_name(e2, e3) &&
 170                    S_ISREG(e2->ce_mode) &&
 171                    S_ISREG(e3->ce_mode)) {
 172                        path_list_insert((const char *)e2->name, conflict);
 173                        i++; /* skip over both #2 and #3 */
 174                }
 175        }
 176        return 0;
 177}
 178
 179static int merge(const char *name, const char *path)
 180{
 181        int ret;
 182        mmfile_t cur, base, other;
 183        mmbuffer_t result = {NULL, 0};
 184        xpparam_t xpp = {XDF_NEED_MINIMAL};
 185
 186        if (handle_file(path, NULL, rr_path(name, "thisimage")) < 0)
 187                return 1;
 188
 189        if (read_mmfile(&cur, rr_path(name, "thisimage")) ||
 190                        read_mmfile(&base, rr_path(name, "preimage")) ||
 191                        read_mmfile(&other, rr_path(name, "postimage")))
 192                return 1;
 193        ret = xdl_merge(&base, &cur, "", &other, "",
 194                        &xpp, XDL_MERGE_ZEALOUS, &result);
 195        if (!ret) {
 196                FILE *f = fopen(path, "w");
 197                if (!f)
 198                        return error("Could not write to %s", path);
 199                fwrite(result.ptr, result.size, 1, f);
 200                fclose(f);
 201        }
 202
 203        free(cur.ptr);
 204        free(base.ptr);
 205        free(other.ptr);
 206        free(result.ptr);
 207
 208        return ret;
 209}
 210
 211static void unlink_rr_item(const char *name)
 212{
 213        unlink(rr_path(name, "thisimage"));
 214        unlink(rr_path(name, "preimage"));
 215        unlink(rr_path(name, "postimage"));
 216        rmdir(git_path("rr-cache/%s", name));
 217}
 218
 219static void garbage_collect(struct path_list *rr)
 220{
 221        struct path_list to_remove = { NULL, 0, 0, 1 };
 222        DIR *dir;
 223        struct dirent *e;
 224        int i, cutoff;
 225        time_t now = time(NULL), then;
 226
 227        dir = opendir(git_path("rr-cache"));
 228        while ((e = readdir(dir))) {
 229                const char *name = e->d_name;
 230                if (name[0] == '.' &&
 231                    (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')))
 232                        continue;
 233                then = rerere_created_at(name);
 234                if (!then)
 235                        continue;
 236                cutoff = (has_resolution(name)
 237                          ? cutoff_resolve : cutoff_noresolve);
 238                if (then < now - cutoff * 86400)
 239                        path_list_append(name, &to_remove);
 240        }
 241        for (i = 0; i < to_remove.nr; i++)
 242                unlink_rr_item(to_remove.items[i].path);
 243        path_list_clear(&to_remove, 0);
 244}
 245
 246static int outf(void *dummy, mmbuffer_t *ptr, int nbuf)
 247{
 248        int i;
 249        for (i = 0; i < nbuf; i++)
 250                if (write_in_full(1, ptr[i].ptr, ptr[i].size) != ptr[i].size)
 251                        return -1;
 252        return 0;
 253}
 254
 255static int diff_two(const char *file1, const char *label1,
 256                const char *file2, const char *label2)
 257{
 258        xpparam_t xpp;
 259        xdemitconf_t xecfg;
 260        xdemitcb_t ecb;
 261        mmfile_t minus, plus;
 262
 263        if (read_mmfile(&minus, file1) || read_mmfile(&plus, file2))
 264                return 1;
 265
 266        printf("--- a/%s\n+++ b/%s\n", label1, label2);
 267        fflush(stdout);
 268        xpp.flags = XDF_NEED_MINIMAL;
 269        memset(&xecfg, 0, sizeof(xecfg));
 270        xecfg.ctxlen = 3;
 271        ecb.outf = outf;
 272        xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 273
 274        free(minus.ptr);
 275        free(plus.ptr);
 276        return 0;
 277}
 278
 279static int do_plain_rerere(struct path_list *rr, int fd)
 280{
 281        struct path_list conflict = { NULL, 0, 0, 1 };
 282        int i;
 283
 284        find_conflict(&conflict);
 285
 286        /*
 287         * MERGE_RR records paths with conflicts immediately after merge
 288         * failed.  Some of the conflicted paths might have been hand resolved
 289         * in the working tree since then, but the initial run would catch all
 290         * and register their preimages.
 291         */
 292
 293        for (i = 0; i < conflict.nr; i++) {
 294                const char *path = conflict.items[i].path;
 295                if (!path_list_has_path(rr, path)) {
 296                        unsigned char sha1[20];
 297                        char *hex;
 298                        int ret;
 299                        ret = handle_file(path, sha1, NULL);
 300                        if (ret < 1)
 301                                continue;
 302                        hex = xstrdup(sha1_to_hex(sha1));
 303                        path_list_insert(path, rr)->util = hex;
 304                        if (mkdir(git_path("rr-cache/%s", hex), 0755))
 305                                continue;;
 306                        handle_file(path, NULL, rr_path(hex, "preimage"));
 307                        fprintf(stderr, "Recorded preimage for '%s'\n", path);
 308                }
 309        }
 310
 311        /*
 312         * Now some of the paths that had conflicts earlier might have been
 313         * hand resolved.  Others may be similar to a conflict already that
 314         * was resolved before.
 315         */
 316
 317        for (i = 0; i < rr->nr; i++) {
 318                int ret;
 319                const char *path = rr->items[i].path;
 320                const char *name = (const char *)rr->items[i].util;
 321
 322                if (has_resolution(name)) {
 323                        if (!merge(name, path)) {
 324                                fprintf(stderr, "Resolved '%s' using "
 325                                                "previous resolution.\n", path);
 326                                goto mark_resolved;
 327                        }
 328                }
 329
 330                /* Let's see if we have resolved it. */
 331                ret = handle_file(path, NULL, NULL);
 332                if (ret)
 333                        continue;
 334
 335                fprintf(stderr, "Recorded resolution for '%s'.\n", path);
 336                copy_file(rr_path(name, "postimage"), path, 0666);
 337        mark_resolved:
 338                rr->items[i].util = NULL;
 339        }
 340
 341        return write_rr(rr, fd);
 342}
 343
 344static int git_rerere_config(const char *var, const char *value, void *cb)
 345{
 346        if (!strcmp(var, "gc.rerereresolved"))
 347                cutoff_resolve = git_config_int(var, value);
 348        else if (!strcmp(var, "gc.rerereunresolved"))
 349                cutoff_noresolve = git_config_int(var, value);
 350        else if (!strcmp(var, "rerere.enabled"))
 351                rerere_enabled = git_config_bool(var, value);
 352        else
 353                return git_default_config(var, value, cb);
 354        return 0;
 355}
 356
 357static int is_rerere_enabled(void)
 358{
 359        struct stat st;
 360        const char *rr_cache;
 361        int rr_cache_exists;
 362
 363        if (!rerere_enabled)
 364                return 0;
 365
 366        rr_cache = git_path("rr-cache");
 367        rr_cache_exists = !stat(rr_cache, &st) && S_ISDIR(st.st_mode);
 368        if (rerere_enabled < 0)
 369                return rr_cache_exists;
 370
 371        if (!rr_cache_exists &&
 372            (mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
 373                die("Could not create directory %s", rr_cache);
 374        return 1;
 375}
 376
 377static int setup_rerere(struct path_list *merge_rr)
 378{
 379        int fd;
 380
 381        git_config(git_rerere_config, NULL);
 382        if (!is_rerere_enabled())
 383                return -1;
 384
 385        merge_rr_path = xstrdup(git_path("rr-cache/MERGE_RR"));
 386        fd = hold_lock_file_for_update(&write_lock, merge_rr_path, 1);
 387        read_rr(merge_rr);
 388        return fd;
 389}
 390
 391int rerere(void)
 392{
 393        struct path_list merge_rr = { NULL, 0, 0, 1 };
 394        int fd;
 395
 396        fd = setup_rerere(&merge_rr);
 397        if (fd < 0)
 398                return 0;
 399        return do_plain_rerere(&merge_rr, fd);
 400}
 401
 402int cmd_rerere(int argc, const char **argv, const char *prefix)
 403{
 404        struct path_list merge_rr = { NULL, 0, 0, 1 };
 405        int i, fd;
 406
 407        fd = setup_rerere(&merge_rr);
 408        if (fd < 0)
 409                return 0;
 410
 411        if (argc < 2)
 412                return do_plain_rerere(&merge_rr, fd);
 413        else if (!strcmp(argv[1], "clear")) {
 414                for (i = 0; i < merge_rr.nr; i++) {
 415                        const char *name = (const char *)merge_rr.items[i].util;
 416                        if (!has_resolution(name))
 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}