diff options
| -rw-r--r-- | Makefile | 5 | ||||
| -rw-r--r-- | merge-base.c | 57 |
2 files changed, 61 insertions, 1 deletions
@@ -14,7 +14,7 @@ CC=gcc PROG= update-cache show-diff init-db write-tree read-tree commit-tree \ cat-file fsck-cache checkout-cache diff-tree rev-tree show-files \ - check-files ls-tree + check-files ls-tree merge-base all: $(PROG) @@ -64,6 +64,9 @@ check-files: check-files.o read-cache.o ls-tree: ls-tree.o read-cache.o $(CC) $(CFLAGS) -o ls-tree ls-tree.o read-cache.o $(LIBS) +merge-base: merge-base.o read-cache.o + $(CC) $(CFLAGS) -o merge-base merge-base.o read-cache.o $(LIBS) + read-cache.o: cache.h show-diff.o: cache.h diff --git a/merge-base.c b/merge-base.c new file mode 100644 index 0000000..36ac420 --- /dev/null +++ b/merge-base.c @@ -0,0 +1,57 @@ +#include "cache.h" +#include "revision.h" + +/* + * This is stupid. We could have much better heurstics, I bet. + */ +static int better(struct revision *new, struct revision *old) +{ + return new->date > old->date; +} + +static struct revision *common_parent(struct revision *rev1, struct revision *rev2) +{ + int i; + struct revision *best = NULL; + + mark_reachable(rev1, 1); + mark_reachable(rev2, 2); + for (i = 0; i < nr_revs ;i++) { + struct revision *rev = revs[i]; + if ((rev->flags & 3) != 3) + continue; + if (!best) { + best = rev; + continue; + } + if (better(rev, best)) + best = rev; + } + return best; +} + +int main(int argc, char **argv) +{ + unsigned char rev1[20], rev2[20]; + struct revision *common; + + if (argc != 3 || get_sha1_hex(argv[1], rev1) || get_sha1_hex(argv[2], rev2)) + usage("merge-base <commit1> <commit2>"); + + /* + * We will eventually want to include a revision cache file + * that "rev-tree.c" has generated, since this is going to + * otherwise be quite expensive for big trees.. + * + * That's some time off, though, and in the meantime we know + * that we have a solution to the eventual expense. + */ + parse_commit(rev1); + parse_commit(rev2); + + common = common_parent(lookup_rev(rev1), lookup_rev(rev2)); + if (!common) + die("no common parent found"); + printf("%s\n", sha1_to_hex(common->sha1)); + return 0; +} |