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

svn path=/main/trunk/; revision=6010

diff --git a/pym/emerge/__init__.py b/pym/emerge/__init__.py
index 6c10439373e3b2d8c292bda3485ac9f6cae69d69..2ce384d469e2634ecf78fadaf193280943b3ebfc 100644 (file)
--- a/pym/emerge/__init__.py
+++ b/pym/emerge/__init__.py
@@ -1971,6 +1971,16 @@ 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][:]
@@ -1980,6 +1990,7 @@ 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