1 files changed, 74 insertions, 0 deletions
diff --git a/catalog/pub/utils/toscaparser/graph.py b/catalog/pub/utils/toscaparser/graph.py
new file mode 100644
index 0000000..0af2a14
--- /dev/null
+++ b/catalog/pub/utils/toscaparser/graph.py
@@ -0,0 +1,74 @@
+# Copyright 2018 ZTE Corporation.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from collections import deque
+from collections import OrderedDict
+
+
+class Graph(object):
+
+    def __init__(self, graph_dict=None):
+        self.graph = OrderedDict()
+        if graph_dict:
+            for node, dep_nodes in list(graph_dict.items()):
+                self.add_node(node, dep_nodes)
+
+    def add_node(self, node, dep_nodes):
+        if node not in self.graph:
+            self.graph[node] = set()
+        if isinstance(dep_nodes, list):
+            for dep_node in dep_nodes:
+                if dep_node not in self.graph:
+                    self.graph[dep_node] = set()
+                if dep_node not in self.graph[node]:
+                    self.graph[node].add(dep_node)
+
+    def get_pre_nodes(self, node):
+        return [k for k in self.graph if node in self.graph[k]]
+
+    def topo_sort(self):
+        degree = {}
+        for node in self.graph:
+            degree[node] = 0
+
+        for node in self.graph:
+            for dependent in self.graph[node]:
+                degree[dependent] += 1
+
+        queue = deque()
+        for node in degree:
+            if degree[node] == 0:
+                queue.appendleft(node)
+
+        sort_list = []
+        while queue:
+            node = queue.pop()
+            sort_list.append(node)
+            for dependent in self.graph[node]:
+                degree[dependent] -= 1
+                if degree[dependent] == 0:
+                    queue.appendleft(dependent)
+
+        if len(sort_list) == len(self.graph):
+            return sort_list
+        else:
+            return None
+
+    def to_dict(self):
+        dict = {}
+        for node, dependents in self.graph.items():
+            dict[node] = []
+            for dep in dependents:
+                dict[node].append(dep)
+        return dict