For bug #167450, optimize leaf node selection by ordering nodes from highest to lowes...

svn path=/main/branches/2.1.2/; revision=6011

diff --git a/bin/emerge b/bin/emerge
index 125d1b7453095b6ca7fc89027e24bf3c771fea08..c5ac0d4d1fea9b2974943cace8a37dcf1a1a994d 100755 (executable)
--- a/bin/emerge
+++ b/bin/emerge
@@ -1967,6 +1967,16 @@ class depgraph:
                                break
                return acceptable
 
+       def _merge_order_bias(self, nodes):
+               """Order nodes from highest to lowest overall reference count for
+               optimal leaf node selection."""
+               node_info = {}
+               for node in self._parent_child_digraph.order:
+                       node_info[node] = len(self.digraph.parent_nodes(node))
+               def cmp_merge_preference(node1, node2):
+                       return node_info[node2] - node_info[node1]
+               nodes.sort(cmp_merge_preference)
+
        def altlist(self, reversed=False):
                if reversed in self._altlist_cache:
                        return self._altlist_cache[reversed][:]
@@ -1976,6 +1986,7 @@ class depgraph:
                        self._altlist_cache[reversed] = retlist[:]
                        return retlist
                mygraph=self.digraph.copy()
+               self._merge_order_bias(mygraph.order)
                myblockers = self.blocker_digraph.copy()
                retlist=[]
                circular_blocks = False