[PATCH] Switch implementations of merge-base, port to parsing

This switches to my implementation of merge-base, but with the new parsing
library.

Signed-Off-By: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/Makefile b/Makefile
index b04c0d8..0c3ba2e 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -64,8 +64,8 @@ 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)
+merge-base: merge-base.o read-cache.o object.o commit.o tree.o blob.o
+       $(CC) $(CFLAGS) -o merge-base merge-base.o read-cache.o object.o commit.o tree.o blob.o $(LIBS)
 
 read-cache.o: cache.h
 show-diff.o: cache.h

diff --git a/merge-base.c b/merge-base.c
index 36ac420..0b99598 100644 (file)
--- a/merge-base.c
+++ b/merge-base.c
@@ -1,57 +1,95 @@
+#include <stdlib.h>
 #include "cache.h"
-#include "revision.h"
+#include "commit.h"
 
-/*
- * This is stupid. We could have much better heurstics, I bet.
- */
-static int better(struct revision *new, struct revision *old)
+static struct commit *process_list(struct commit_list **list_p, int this_mark,
+                                  int other_mark)
 {
-       return new->date > old->date;
+       struct commit_list *parent, *temp;
+       struct commit_list *posn = *list_p;
+       *list_p = NULL;
+       while (posn) {
+               parse_commit(posn->item);
+               if (posn->item->object.flags & this_mark) {
+                       /*
+                         printf("%d already seen %s %x\n",
+                         this_mark
+                         sha1_to_hex(posn->parent->sha1),
+                         posn->parent->flags);
+                       */
+                       /* do nothing; this indicates that this side
+                        * split and reformed, and we only need to
+                        * mark it once.
+                        */
+               } else if (posn->item->object.flags & other_mark) {
+                       return posn->item;
+               } else {
+                       /*
+                         printf("%d based on %s\n",
+                         this_mark,
+                         sha1_to_hex(posn->parent->sha1));
+                       */
+                       posn->item->object.flags |= this_mark;
+                       
+                       parent = posn->item->parents;
+                       while (parent) {
+                               temp = malloc(sizeof(struct commit_list));
+                               temp->next = *list_p;
+                               temp->item = parent->item;
+                               *list_p = temp;
+                               parent = parent->next;
+                       }
+               }
+               posn = posn->next;
+       }
+       return NULL;
 }
 
-static struct revision *common_parent(struct revision *rev1, struct revision *rev2)
+struct commit *common_ancestor(struct commit *rev1, struct commit *rev2)
 {
-       int i;
-       struct revision *best = NULL;
+       struct commit_list *rev1list = malloc(sizeof(struct commit_list));
+       struct commit_list *rev2list = malloc(sizeof(struct commit_list));
+
+       rev1list->item = rev1;
+       rev1list->next = 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;
+       rev2list->item = rev2;
+       rev2list->next = NULL;
+
+       while (rev1list || rev2list) {
+               struct commit *ret;
+               ret = process_list(&rev1list, 0x1, 0x2);
+               if (ret) {
+                       /* XXXX free lists */
+                       return ret;
+               }
+               ret = process_list(&rev2list, 0x2, 0x1);
+               if (ret) {
+                       /* XXXX free lists */
+                       return ret;
                }
-               if (better(rev, best))
-                       best = rev;
        }
-       return best;
+       return NULL;
 }
 
 int main(int argc, char **argv)
 {
-       unsigned char rev1[20], rev2[20];
-       struct revision *common;
+       struct commit *rev1, *rev2, *ret;
+       unsigned char rev1key[20], rev2key[20];
 
-       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;
+       if (argc != 3 ||
+           get_sha1_hex(argv[1], rev1key) ||
+           get_sha1_hex(argv[2], rev2key)) {
+               usage("merge-base <commit-id> <commit-id>");
+       }
+       rev1 = lookup_commit(rev1key);
+       rev2 = lookup_commit(rev2key);
+       ret = common_ancestor(rev1, rev2);
+       if (ret) {
+               printf("%s\n", sha1_to_hex(ret->object.sha1));
+               return 0;
+       } else {
+               return 1;
+       }
+       
 }