In depgraph.altlist(), measure the bias of circular

RDEPEND <-> PDEPEND relationships and use it to
optimize merge order. (trunk r8593)

svn path=/main/branches/2.1.2/; revision=8594

diff --git a/bin/emerge b/bin/emerge
index bb56f5e5b1256f065ba61fc77e87222498216652..ee5b6426432580a4812f927fca449462a5eeb0d3 100755 (executable)
--- a/bin/emerge
+++ b/bin/emerge
@@ -2394,6 +2394,21 @@ class depgraph:
                        return retlist
                mygraph=self.digraph.copy()
                self._merge_order_bias(mygraph)
+               def cmp_circular_bias(n1, n2):
+                       """
+                       RDEPEND is stronger than PDEPEND and this function
+                       measures such a strength bias within a circular
+                       dependency relationship.
+                       """
+                       n1_n2_medium = n2 in mygraph.child_nodes(n1,
+                               ignore_priority=DepPriority.MEDIUM_SOFT)
+                       n2_n1_medium = n1 in mygraph.child_nodes(n2,
+                               ignore_priority=DepPriority.MEDIUM_SOFT)
+                       if n1_n2_medium == n2_n1_medium:
+                               return 0
+                       elif n1_n2_medium:
+                               return 1
+                       return -1
                myblockers = self.blocker_digraph.copy()
                retlist=[]
                circular_blocks = False
@@ -2559,6 +2574,11 @@ class depgraph:
                                                        continue
                                                asap_nodes.append(child)
 
+                       if selected_nodes and len(selected_nodes) > 1:
+                               if not isinstance(selected_nodes, list):
+                                       selected_nodes = list(selected_nodes)
+                               selected_nodes.sort(cmp_circular_bias)
+
                        if not selected_nodes:
                                if not myblockers.is_empty():
                                        """A blocker couldn't be circumnavigated while keeping all