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