rev-tree.c

   1 #include "cache.h"
   2 #include "commit.h"
   3
   4 /*
   5  * revision.h leaves the low 16 bits of the "flags" field of the
   6  * revision data structure unused. We use it for a "reachable from
   7  * this commit <N>" bitmask.
   8  */
   9 #define MAX_COMMITS 16
  10 #define REACHABLE (1U << 16)
  11
  12 #define cmit_flags(cmit) ((cmit)->object.flags & ~REACHABLE)
  13
  14 static int show_edges = 0;
  15 static int basemask = 0;
  16
  17 static void read_cache_file(const char *path)
  18 {
  19         die("no revtree cache file yet");
  20 }
  21
  22 /*
  23  * Some revisions are less interesting than others.
  24  *
  25  * For example, if we use a cache-file, that one may contain
  26  * revisions that were never used. They are never interesting.
  27  *
  28  * And sometimes we're only interested in "edge" commits, ie
  29  * places where the marking changes between parent and child.
  30  */
  31 static int interesting(struct commit *rev)
  32 {
  33         unsigned mask = cmit_flags(rev);
  34
  35         if (!mask)
  36                 return 0;
  37         if (show_edges) {
  38                 struct commit_list *p = rev->parents;
  39                 while (p) {
  40                         if (mask != cmit_flags(p->item))
  41                                 return 1;
  42                         p = p->next;
  43                 }
  44                 return 0;
  45         }
  46         if (mask & basemask)
  47                 return 0;
  48
  49         return 1;
  50 }
  51
  52 /*
  53  * Usage: git-rev-tree [--edges] [--cache <cache-file>] <commit-id> [<commit-id2>]
  54  *
  55  * The cache-file can be quite important for big trees. This is an
  56  * expensive operation if you have to walk the whole chain of
  57  * parents in a tree with a long revision history.
  58  */
  59 int main(int argc, char **argv)
  60 {
  61         int i;
  62         int nr = 0;
  63         unsigned char sha1[MAX_COMMITS][20];
  64         struct commit_list *list = NULL;
  65
  66         /*
  67          * First - pick up all the revisions we can (both from
  68          * caches and from commit file chains).
  69          */
  70         for (i = 1; i < argc ; i++) {
  71                 char *arg = argv[i];
  72                 struct commit *commit;
  73
  74                 if (!strcmp(arg, "--cache")) {
  75                         read_cache_file(argv[++i]);
  76                         continue;
  77                 }
  78
  79                 if (!strcmp(arg, "--edges")) {
  80                         show_edges = 1;
  81                         continue;
  82                 }
  83
  84                 if (arg[0] == '^') {
  85                         arg++;
  86                         basemask |= 1<<nr;
  87                 }
  88                 if (nr >= MAX_COMMITS || get_sha1(arg, sha1[nr]))
  89                         usage("git-rev-tree [--edges] [--cache <cache-file>] <commit-id> [<commit-id>]");
  90
  91                 commit = lookup_commit_reference(sha1[nr]);
  92                 if (!commit || parse_commit(commit) < 0)
  93                         die("bad commit object");
  94                 commit_list_insert(commit, &list);
  95                 nr++;
  96         }
  97
  98         /*
  99          * Parse all the commits in date order.
 100          *
 101          * We really should stop once we know enough, but that's a
 102          * decision that isn't trivial to make.
 103          */
 104         while (list)
 105                 pop_most_recent_commit(&list, REACHABLE);
 106
 107         /*
 108          * Now we have the maximal tree. Walk the different sha files back to the root.
 109          */
 110         for (i = 0; i < nr; i++)
 111                 mark_reachable(&lookup_commit_reference(sha1[i])->object, 1 << i);
 112
 113         /*
 114          * Now print out the results..
 115          */
 116         for (i = 0; i < nr_objs; i++) {
 117                 struct object *obj = objs[i];
 118                 struct commit *commit;
 119                 struct commit_list *p;
 120
 121                 if (obj->type != commit_type)
 122                         continue;
 123
 124                 commit = (struct commit *) obj;
 125
 126                 if (!interesting(commit))
 127                         continue;
 128
 129                 printf("%lu %s:%d", commit->date, sha1_to_hex(obj->sha1),
 130                                     cmit_flags(commit));
 131                 p = commit->parents;
 132                 while (p) {
 133                         printf(" %s:%d", sha1_to_hex(p->item->object.sha1),
 134                                cmit_flags(p->item));
 135                         p = p->next;
 136                 }
 137                 printf("\n");
 138         }
 139         return 0;
 140 }