move ifupdown2/* .

ifupdown2 code was one level deeper because ifupdown2 initially
had ifupdown2 and ifupdown2-addons as two separate packages.
Since they were combined into one package, it makes sense to
move all combined code under the top level directory

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>

ifupdown/graph.py

@@ -0,0 +1,89 @@
+#!/usr/bin/python
+#
+# Copyright 2014 Cumulus Networks, Inc. All rights reserved.
+# Author: Roopa Prabhu, roopa@cumulusnetworks.com
+#
+# graph --
+#    graph helper module for ifupdown
+#
+
+import logging
+import copy
+from collections import deque
+try:
+    from gvgen import *
+except ImportError as e:
+    pass
+
+class graph():
+    """ graph functions to sort and print interface graph """
+
+    def __init__(self):
+        self.logger = logging.getLogger('ifupdown.' +
+                    self.__class__.__name__)
+
+    @classmethod
+    def topological_sort_graphs_all(cls, dependency_graphs, indegrees_arg):
+        """ runs topological sort on interface list passed as dependency graph
+
+        Args:
+            **dependency_graphs** (dict): dependency graph with dependency
+                                          lists for interfaces 
+
+            **indegrees_arg** (dict): indegrees array for all interfaces
+        """
+        S = []
+        Q = deque()
+
+        indegrees = copy.deepcopy(indegrees_arg)
+        for ifname,indegree in indegrees.items():
+            if indegree == 0:
+                Q.append(ifname)
+
+        while len(Q):
+            # initialize queue
+            x = Q.popleft()
+
+            # Get dependents of x
+            dlist = dependency_graphs.get(x)
+            if not dlist:
+                S.append(x)
+                continue
+
+            for y in dlist:
+                indegrees[y] = indegrees.get(y) - 1
+                if indegrees.get(y) == 0:
+                    Q.append(y)
+
+            S.append(x)
+
+        for ifname,indegree in indegrees.items():
+            if indegree != 0:
+                raise Exception('cycle found involving iface %s' %ifname +
+                                ' (indegree %d)' %indegree)
+
+        return S
+
+    @classmethod
+    def generate_dots(cls, dependency_graph, indegrees):
+        """ spits out interface dependency graph in dot format
+
+        Args:
+            **dependency_graphs** (dict): dependency graph with dependency
+                                          lists for interfaces 
+
+            **indegrees_arg** (dict): indegrees array for all interfaces
+        """
+
+        gvgraph = GvGen()
+        graphnodes = {}
+        for v in dependency_graph.keys():
+            graphnodes[v] = gvgraph.newItem(v)
+
+        for i, v in graphnodes.items():
+            dlist = dependency_graph.get(i, [])
+            if not dlist:
+                continue
+            for d in dlist:
+                gvgraph.newLink(v, graphnodes.get(d))
+        gvgraph.dot()