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         *all = nr;
 186         closest = 0;
 187         best = list;
 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 struct commit_list *find_bisection_2(struct commit_list *list,
 241                                             int *reaches, int *all)
 242 {
 243         int n, nr, counted, distance;
 244         struct commit_list *p, *best;
 245         int *weights;
 246
 247         for (nr = 0, p = list; p; p = p->next) {
 248                 if (commit_interesting(p))
 249                         nr++;
 250         }
 251         *all = nr;
 252         weights = xcalloc(nr, sizeof(int*));
 253         counted = 0;
 254
 255         for (n = 0, p = list; p; p = p->next) {
 256                 if (!commit_interesting(p))
 257                         continue;
 258                 if (commit_interesting(p)) {
 259                         /*
 260                          * positive weight is the number of interesting
 261                          * commits it can reach, including itself.
 262                          * weight = 0 means it has one parent and
 263                          * its distance is unknown.
 264                          * weight < 0 means it has more than one
 265                          * parent and its distance is unknown.
 266                          */
 267                         p->item->util = &weights[n++];
 268                         switch (count_interesting_parents(p)) {
 269                         case 0:
 270                                 weight_set(p, 1);
 271                                 counted++;
 272                                 break;
 273                         case 1:
 274                                 weight_set(p, 0);
 275                                 break;
 276                         default:
 277                                 weight_set(p, -1);
 278                                 break;
 279                         }
 280                 }
 281         }
 282
 283         /*
 284          * If you have only one parent in the resulting set
 285          * then you can reach one commit more than that parent
 286          * can reach.  So we do not have to run the expensive
 287          * count_distance() for single strand of pearls.
 288          *
 289          * However, if you have more than one parents, you cannot
 290          * just add their distance and one for yourself, since
 291          * they usually reach the same ancestor and you would
 292          * end up counting them twice that way.
 293          *
 294          * So we will first count distance of merges the usual
 295          * way, and then fill the blanks using cheaper algorithm.
 296          */
 297         for (p = list; p; p = p->next) {
 298                 if (!commit_interesting(p))
 299                         continue;
 300                 n = weight(p);
 301                 if (0 <= n)
 302                         continue;
 303                 distance = count_distance(p);
 304                 clear_distance(p);
 305                 weight_set(p, distance);
 306
 307                 /* Does it happen to be at exactly half-way? */
 308                 distance *= 2;
 309                 if (nr == distance || (nr+1) == distance) {
 310                         p->next = NULL;
 311                         *reaches = weight(p);
 312                         free(weights);
 313                         return p;
 314                 }
 315                 counted++;
 316         }
 317
 318         while (counted < nr) {
 319                 for (p = list; p; p = p->next) {
 320                         struct commit_list *q;
 321
 322                         if (!commit_interesting(p) || 0 < weight(p))
 323                                 continue;
 324                         for (q = p->item->parents; q; q = q->next)
 325                                 if (commit_interesting(q) && 0 < weight(q))
 326                                         break;
 327                         if (!q)
 328                                 continue;
 329                         weight_set(p, weight(q)+1);
 330                         counted++;
 331
 332                         /* Does it happen to be at exactly half-way? */
 333                         distance = weight(p) * 2;
 334                         if (nr == distance || (nr+1) == distance) {
 335                                 p->next = NULL;
 336                                 *reaches = weight(p);
 337                                 free(weights);
 338                                 return p;
 339                         }
 340                 }
 341         }
 342
 343         /* Then find the best one */
 344         counted = 0;
 345         best = list;
 346         for (p = list; p; p = p->next) {
 347                 if (!commit_interesting(p))
 348                         continue;
 349                 distance = weight(p);
 350                 if (nr - distance < distance)
 351                         distance = nr - distance;
 352                 if (distance > counted) {
 353                         best = p;
 354                         counted = distance;
 355                         *reaches = weight(p);
 356                 }
 357         }
 358         if (best)
 359                 best->next = NULL;
 360         free(weights);
 361         return best;
 362 }
 363
 364 static void read_revisions_from_stdin(struct rev_info *revs)
 365 {
 366         char line[1000];
 367
 368         while (fgets(line, sizeof(line), stdin) != NULL) {
 369                 int len = strlen(line);
 370                 if (line[len - 1] == '\n')
 371                         line[--len] = 0;
 372                 if (!len)
 373                         break;
 374                 if (line[0] == '-')
 375                         die("options not supported in --stdin mode");
 376                 if (handle_revision_arg(line, revs, 0, 1))
 377                         die("bad revision '%s'", line);
 378         }
 379 }
 380
 381 int cmd_rev_list(int argc, const char **argv, const char *prefix)
 382 {
 383         struct commit_list *list;
 384         int i;
 385         int read_from_stdin = 0;
 386         int bisect_show_vars = 0;
 387
 388         git_config(git_default_config);
 389         init_revisions(&revs, prefix);
 390         revs.abbrev = 0;
 391         revs.commit_format = CMIT_FMT_UNSPECIFIED;
 392         argc = setup_revisions(argc, argv, &revs, NULL);
 393
 394         for (i = 1 ; i < argc; i++) {
 395                 const char *arg = argv[i];
 396
 397                 if (!strcmp(arg, "--header")) {
 398                         revs.verbose_header = 1;
 399                         continue;
 400                 }
 401                 if (!strcmp(arg, "--timestamp")) {
 402                         show_timestamp = 1;
 403                         continue;
 404                 }
 405                 if (!strcmp(arg, "--bisect")) {
 406                         bisect_list = 1;
 407                         continue;
 408                 }
 409                 if (!strcmp(arg, "--bisect-vars")) {
 410                         bisect_list = 1;
 411                         bisect_show_vars = 1;
 412                         continue;
 413                 }
 414                 if (!strcmp(arg, "--stdin")) {
 415                         if (read_from_stdin++)
 416                                 die("--stdin given twice?");
 417                         read_revisions_from_stdin(&revs);
 418                         continue;
 419                 }
 420                 usage(rev_list_usage);
 421
 422         }
 423         if (revs.commit_format != CMIT_FMT_UNSPECIFIED) {
 424                 /* The command line has a --pretty  */
 425                 hdr_termination = '\n';
 426                 if (revs.commit_format == CMIT_FMT_ONELINE)
 427                         header_prefix = "";
 428                 else
 429                         header_prefix = "commit ";
 430         }
 431         else if (revs.verbose_header)
 432                 /* Only --header was specified */
 433                 revs.commit_format = CMIT_FMT_RAW;
 434
 435         list = revs.commits;
 436
 437         if ((!list &&
 438              (!(revs.tag_objects||revs.tree_objects||revs.blob_objects) &&
 439               !revs.pending.nr)) ||
 440             revs.diff)
 441                 usage(rev_list_usage);
 442
 443         save_commit_buffer = revs.verbose_header || revs.grep_filter;
 444         track_object_refs = 0;
 445         if (bisect_list)
 446                 revs.limited = 1;
 447
 448         prepare_revision_walk(&revs);
 449         if (revs.tree_objects)
 450                 mark_edges_uninteresting(revs.commits, &revs, show_edge);
 451
 452         if (bisect_list) {
 453                 int reaches = reaches, all = all;
 454
 455                 if (!revs.prune_fn)
 456                         revs.commits = find_bisection_2(revs.commits,
 457                                                         &reaches, &all);
 458                 else
 459                         revs.commits = find_bisection(revs.commits,
 460                                                       &reaches, &all);
 461                 if (bisect_show_vars) {
 462                         int cnt;
 463                         if (!revs.commits)
 464                                 return 1;
 465                         /*
 466                          * revs.commits can reach "reaches" commits among
 467                          * "all" commits.  If it is good, then there are
 468                          * (all-reaches) commits left to be bisected.
 469                          * On the other hand, if it is bad, then the set
 470                          * to bisect is "reaches".
 471                          * A bisect set of size N has (N-1) commits further
 472                          * to test, as we already know one bad one.
 473                          */
 474                         cnt = all-reaches;
 475                         if (cnt < reaches)
 476                                 cnt = reaches;
 477                         printf("bisect_rev=%s\n"
 478                                "bisect_nr=%d\n"
 479                                "bisect_good=%d\n"
 480                                "bisect_bad=%d\n"
 481                                "bisect_all=%d\n",
 482                                sha1_to_hex(revs.commits->item->object.sha1),
 483                                cnt - 1,
 484                                all - reaches - 1,
 485                                reaches - 1,
 486                                all);
 487                         return 0;
 488                 }
 489         }
 490
 491         traverse_commit_list(&revs, show_commit, show_object);
 492
 493         return 0;
 494 }