builtin-rev-list.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "tag.h"
   4 #include "commit.h"
   5 #include "tree.h"
   6 #include "blob.h"
   7 #include "tree-walk.h"
   8 #include "diff.h"
   9 #include "revision.h"
  10 #include "list-objects.h"
  11 #include "builtin.h"
  12
  13 /* bits #0-15 in revision.h */
  14
  15 #define COUNTED         (1u<<16)
  16
  17 static const char rev_list_usage[] =
  18 "git-rev-list [OPTION] <commit-id>... [ -- paths... ]\n"
  19 "  limiting output:\n"
  20 "    --max-count=nr\n"
  21 "    --max-age=epoch\n"
  22 "    --min-age=epoch\n"
  23 "    --sparse\n"
  24 "    --no-merges\n"
  25 "    --remove-empty\n"
  26 "    --all\n"
  27 "    --stdin\n"
  28 "  ordering output:\n"
  29 "    --topo-order\n"
  30 "    --date-order\n"
  31 "  formatting output:\n"
  32 "    --parents\n"
  33 "    --objects | --objects-edge\n"
  34 "    --unpacked\n"
  35 "    --header | --pretty\n"
  36 "    --abbrev=nr | --no-abbrev\n"
  37 "    --abbrev-commit\n"
  38 "  special purpose:\n"
  39 "    --bisect\n"
  40 "    --bisect-vars"
  41 ;
  42
  43 static struct rev_info revs;
  44
  45 static int bisect_list;
  46 static int show_timestamp;
  47 static int hdr_termination;
  48 static const char *header_prefix;
  49
  50 static void show_commit(struct commit *commit)
  51 {
  52         if (show_timestamp)
  53                 printf("%lu ", commit->date);
  54         if (header_prefix)
  55                 fputs(header_prefix, stdout);
  56         if (commit->object.flags & BOUNDARY)
  57                 putchar('-');
  58         else if (revs.left_right) {
  59                 if (commit->object.flags & SYMMETRIC_LEFT)
  60                         putchar('<');
  61                 else
  62                         putchar('>');
  63         }
  64         if (revs.abbrev_commit && revs.abbrev)
  65                 fputs(find_unique_abbrev(commit->object.sha1, revs.abbrev),
  66                       stdout);
  67         else
  68                 fputs(sha1_to_hex(commit->object.sha1), stdout);
  69         if (revs.parents) {
  70                 struct commit_list *parents = commit->parents;
  71                 while (parents) {
  72                         struct object *o = &(parents->item->object);
  73                         parents = parents->next;
  74                         if (o->flags & TMP_MARK)
  75                                 continue;
  76                         printf(" %s", sha1_to_hex(o->sha1));
  77                         o->flags |= TMP_MARK;
  78                 }
  79                 /* TMP_MARK is a general purpose flag that can
  80                  * be used locally, but the user should clean
  81                  * things up after it is done with them.
  82                  */
  83                 for (parents = commit->parents;
  84                      parents;
  85                      parents = parents->next)
  86                         parents->item->object.flags &= ~TMP_MARK;
  87         }
  88         if (revs.commit_format == CMIT_FMT_ONELINE)
  89                 putchar(' ');
  90         else
  91                 putchar('\n');
  92
  93         if (revs.verbose_header) {
  94                 static char pretty_header[16384];
  95                 pretty_print_commit(revs.commit_format, commit, ~0,
  96                                     pretty_header, sizeof(pretty_header),
  97                                     revs.abbrev, NULL, NULL, revs.relative_date);
  98                 printf("%s%c", pretty_header, hdr_termination);
  99         }
 100         fflush(stdout);
 101         if (commit->parents) {
 102                 free_commit_list(commit->parents);
 103                 commit->parents = NULL;
 104         }
 105         free(commit->buffer);
 106         commit->buffer = NULL;
 107 }
 108
 109 static void show_object(struct object_array_entry *p)
 110 {
 111         /* An object with name "foo\n0000000..." can be used to
 112          * confuse downstream git-pack-objects very badly.
 113          */
 114         const char *ep = strchr(p->name, '\n');
 115         if (ep) {
 116                 printf("%s %.*s\n", sha1_to_hex(p->item->sha1),
 117                        (int) (ep - p->name),
 118                        p->name);
 119         }
 120         else
 121                 printf("%s %s\n", sha1_to_hex(p->item->sha1), p->name);
 122 }
 123
 124 static void show_edge(struct commit *commit)
 125 {
 126         printf("-%s\n", sha1_to_hex(commit->object.sha1));
 127 }
 128
 129 /*
 130  * This is a truly stupid algorithm, but it's only
 131  * used for bisection, and we just don't care enough.
 132  *
 133  * We care just barely enough to avoid recursing for
 134  * non-merge entries.
 135  */
 136 static int count_distance(struct commit_list *entry)
 137 {
 138         int nr = 0;
 139
 140         while (entry) {
 141                 struct commit *commit = entry->item;
 142                 struct commit_list *p;
 143
 144                 if (commit->object.flags & (UNINTERESTING | COUNTED))
 145                         break;
 146                 if (!revs.prune_fn || (commit->object.flags & TREECHANGE))
 147                         nr++;
 148                 commit->object.flags |= COUNTED;
 149                 p = commit->parents;
 150                 entry = p;
 151                 if (p) {
 152                         p = p->next;
 153                         while (p) {
 154                                 nr += count_distance(p);
 155                                 p = p->next;
 156                         }
 157                 }
 158         }
 159
 160         return nr;
 161 }
 162
 163 static void clear_distance(struct commit_list *list)
 164 {
 165         while (list) {
 166                 struct commit *commit = list->item;
 167                 commit->object.flags &= ~COUNTED;
 168                 list = list->next;
 169         }
 170 }
 171
 172 static struct commit_list *find_bisection(struct commit_list *list,
 173                                           int *reaches, int *all)
 174 {
 175         int nr, closest;
 176         struct commit_list *p, *best;
 177
 178         nr = 0;
 179         p = list;
 180         while (p) {
 181                 if (!revs.prune_fn || (p->item->object.flags & TREECHANGE))
 182                         nr++;
 183                 p = p->next;
 184         }
 185         closest = -1;
 186         best = list;
 187         *all = nr;
 188
 189         for (p = list; p; p = p->next) {
 190                 int distance, reach;
 191
 192                 if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
 193                         continue;
 194
 195                 distance = reach = count_distance(p);
 196                 clear_distance(list);
 197                 if (nr - distance < distance)
 198                         distance = nr - distance;
 199                 if (distance > closest) {
 200                         best = p;
 201                         *reaches = reach;
 202                         closest = distance;
 203                 }
 204         }
 205         if (best)
 206                 best->next = NULL;
 207         return best;
 208 }
 209
 210 static inline int commit_interesting(struct commit_list *elem)
 211 {
 212         unsigned flags = elem->item->object.flags;
 213         if (flags & UNINTERESTING)
 214                 return 0;
 215         return (!revs.prune_fn || (flags & TREECHANGE));
 216 }
 217
 218 static inline int weight(struct commit_list *elem)
 219 {
 220         return *((int*)(elem->item->util));
 221 }
 222
 223 static inline void weight_set(struct commit_list *elem, int weight)
 224 {
 225         *((int*)(elem->item->util)) = weight;
 226 }
 227
 228 static int count_interesting_parents(struct commit_list *elem)
 229 {
 230         int cnt = 0;
 231         if (!elem->item->parents)
 232                 return cnt;
 233         for (elem = elem->item->parents; elem; elem = elem->next) {
 234                 if (commit_interesting(elem))
 235                         cnt++;
 236         }
 237         return cnt;
 238 }
 239
 240 static inline int halfway(struct commit_list *p, int distance, int nr)
 241 {
 242         /*
 243          * Don't short-cut something we are not going to return!
 244          */
 245         if (revs.prune_fn && !(p->item->object.flags & TREECHANGE))
 246                 return 0;
 247
 248         /*
 249          * 2 and 3 are halfway of 5.
 250          * 3 is halfway of 6 but 2 and 4 are not.
 251          */
 252         distance *= 2;
 253         switch (distance - nr) {
 254         case -1: case 0: case 1:
 255                 return 1;
 256         default:
 257                 return 0;
 258         }
 259 }
 260
 261 static struct commit_list *find_bisection_2(struct commit_list *list,
 262                                             int *reaches, int *all)
 263 {
 264         int n, nr, counted, distance;
 265         struct commit_list *p, *best;
 266         int *weights;
 267
 268         for (nr = 0, p = list; p; p = p->next) {
 269                 if (commit_interesting(p))
 270                         nr++;
 271         }
 272         *all = nr;
 273         weights = xcalloc(nr, sizeof(int*));
 274         counted = 0;
 275
 276         for (n = 0, p = list; p; p = p->next) {
 277                 if (!commit_interesting(p))
 278                         continue;
 279                 if (commit_interesting(p)) {
 280                         /*
 281                          * positive weight is the number of interesting
 282                          * commits it can reach, including itself.
 283                          * weight = 0 means it has one parent and
 284                          * its distance is unknown.
 285                          * weight < 0 means it has more than one
 286                          * parent and its distance is unknown.
 287                          */
 288                         p->item->util = &weights[n++];
 289                         switch (count_interesting_parents(p)) {
 290                         case 0:
 291                                 weight_set(p, 1);
 292                                 counted++;
 293                                 break;
 294                         case 1:
 295                                 weight_set(p, 0);
 296                                 break;
 297                         default:
 298                                 weight_set(p, -1);
 299                                 break;
 300                         }
 301                 }
 302         }
 303
 304         /*
 305          * If you have only one parent in the resulting set
 306          * then you can reach one commit more than that parent
 307          * can reach.  So we do not have to run the expensive
 308          * count_distance() for single strand of pearls.
 309          *
 310          * However, if you have more than one parents, you cannot
 311          * just add their distance and one for yourself, since
 312          * they usually reach the same ancestor and you would
 313          * end up counting them twice that way.
 314          *
 315          * So we will first count distance of merges the usual
 316          * way, and then fill the blanks using cheaper algorithm.
 317          */
 318         for (p = list; p; p = p->next) {
 319                 if (!commit_interesting(p))
 320                         continue;
 321                 n = weight(p);
 322                 if (0 <= n)
 323                         continue;
 324                 distance = count_distance(p);
 325                 clear_distance(p);
 326                 weight_set(p, distance);
 327
 328                 /* Does it happen to be at exactly half-way? */
 329                 if (halfway(p, distance, nr)) {
 330                         p->next = NULL;
 331                         *reaches = distance;
 332                         free(weights);
 333                         return p;
 334                 }
 335                 counted++;
 336         }
 337
 338         while (counted < nr) {
 339                 for (p = list; p; p = p->next) {
 340                         struct commit_list *q;
 341
 342                         if (!commit_interesting(p) || 0 < weight(p))
 343                                 continue;
 344                         for (q = p->item->parents; q; q = q->next)
 345                                 if (commit_interesting(q) && 0 < weight(q))
 346                                         break;
 347                         if (!q)
 348                                 continue;
 349                         weight_set(p, weight(q)+1);
 350                         counted++;
 351
 352                         /* Does it happen to be at exactly half-way? */
 353                         distance = weight(p);
 354                         if (halfway(p, distance, nr)) {
 355                                 p->next = NULL;
 356                                 *reaches = distance;
 357                                 free(weights);
 358                                 return p;
 359                         }
 360                 }
 361         }
 362
 363         /* Then find the best one */
 364         counted = 0;
 365         best = list;
 366         for (p = list; p; p = p->next) {
 367                 if (!commit_interesting(p))
 368                         continue;
 369                 distance = weight(p);
 370                 if (nr - distance < distance)
 371                         distance = nr - distance;
 372                 if (distance > counted) {
 373                         best = p;
 374                         counted = distance;
 375                         *reaches = weight(p);
 376                 }
 377         }
 378         if (best)
 379                 best->next = NULL;
 380         free(weights);
 381         return best;
 382 }
 383
 384 static void read_revisions_from_stdin(struct rev_info *revs)
 385 {
 386         char line[1000];
 387
 388         while (fgets(line, sizeof(line), stdin) != NULL) {
 389                 int len = strlen(line);
 390                 if (line[len - 1] == '\n')
 391                         line[--len] = 0;
 392                 if (!len)
 393                         break;
 394                 if (line[0] == '-')
 395                         die("options not supported in --stdin mode");
 396                 if (handle_revision_arg(line, revs, 0, 1))
 397                         die("bad revision '%s'", line);
 398         }
 399 }
 400
 401 int cmd_rev_list(int argc, const char **argv, const char *prefix)
 402 {
 403         struct commit_list *list;
 404         int i;
 405         int read_from_stdin = 0;
 406         int bisect_show_vars = 0;
 407
 408         git_config(git_default_config);
 409         init_revisions(&revs, prefix);
 410         revs.abbrev = 0;
 411         revs.commit_format = CMIT_FMT_UNSPECIFIED;
 412         argc = setup_revisions(argc, argv, &revs, NULL);
 413
 414         for (i = 1 ; i < argc; i++) {
 415                 const char *arg = argv[i];
 416
 417                 if (!strcmp(arg, "--header")) {
 418                         revs.verbose_header = 1;
 419                         continue;
 420                 }
 421                 if (!strcmp(arg, "--timestamp")) {
 422                         show_timestamp = 1;
 423                         continue;
 424                 }
 425                 if (!strcmp(arg, "--bisect")) {
 426                         bisect_list = 1;
 427                         continue;
 428                 }
 429                 if (!strcmp(arg, "--bisect-vars")) {
 430                         bisect_list = 1;
 431                         bisect_show_vars = 1;
 432                         continue;
 433                 }
 434                 if (!strcmp(arg, "--stdin")) {
 435                         if (read_from_stdin++)
 436                                 die("--stdin given twice?");
 437                         read_revisions_from_stdin(&revs);
 438                         continue;
 439                 }
 440                 usage(rev_list_usage);
 441
 442         }
 443         if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
 444                 /* The command line has a --pretty  */
 445                 hdr_termination = '\n';
 446                 if (revs.commit_format == CMIT_FMT_ONELINE)
 447                         header_prefix = "";
 448                 else
 449                         header_prefix = "commit ";
 450         }
 451         else if (revs.verbose_header)
 452                 /* Only --header was specified */
 453                 revs.commit_format = CMIT_FMT_RAW;
 454
 455         list = revs.commits;
 456
 457         if ((!list &&
 458              (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
 459               !revs.pending.nr)) ||
 460             revs.diff)
 461                 usage(rev_list_usage);
 462
 463         save_commit_buffer = revs.verbose_header || revs.grep_filter;
 464         track_object_refs = 0;
 465         if (bisect_list)
 466                 revs.limited = 1;
 467
 468         prepare_revision_walk(&revs);
 469         if (revs.tree_objects)
 470                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 471
 472         if (bisect_list) {
 473                 int reaches = reaches, all = all;
 474
 475                 if (!revs.prune_fn)
 476                         revs.commits = find_bisection_2(revs.commits,
 477                                                         &reaches, &all);
 478                 else
 479                         revs.commits = find_bisection(revs.commits,
 480                                                       &reaches, &all);
 481                 if (bisect_show_vars) {
 482                         int cnt;
 483                         if (!revs.commits)
 484                                 return 1;
 485                         /*
 486                          * revs.commits can reach "reaches" commits among
 487                          * "all" commits.  If it is good, then there are
 488                          * (all-reaches) commits left to be bisected.
 489                          * On the other hand, if it is bad, then the set
 490                          * to bisect is "reaches".
 491                          * A bisect set of size N has (N-1) commits further
 492                          * to test, as we already know one bad one.
 493                          */
 494                         cnt = all-reaches;
 495                         if (cnt < reaches)
 496                                 cnt = reaches;
 497                         printf("bisect_rev=%s\n"
 498                                "bisect_nr=%d\n"
 499                                "bisect_good=%d\n"
 500                                "bisect_bad=%d\n"
 501                                "bisect_all=%d\n",
 502                                sha1_to_hex(revs.commits->item->object.sha1),
 503                                cnt - 1,
 504                                all - reaches - 1,
 505                                reaches - 1,
 506                                all);
 507                         return 0;
 508                 }
 509         }
 510
 511         traverse_commit_list(&revs, show_commit, show_object);
 512
 513         return 0;
 514 }