Add OpProtoHolder

python/paddle/v2/framework/graph.py

 import paddle.v2.framework.core as core
+import paddle.v2.framework.proto.framework_pb2 as framework_pb2
 import collections
 
 __all__ = ['Block', 'Variable', 'Program', 'Operator']
 
 
+def get_all_op_protos():
+    """
+    Get all registered op proto from PaddlePaddle C++ end.
+    :return: A list of registered OpProto.
+    """
+    protostrs = core.get_all_op_protos()
+    ret_values = []
+    for pbstr in protostrs:
+        op_proto = framework_pb2.OpProto.FromString(str(pbstr))
+        ret_values.append(op_proto)
+    return ret_values
+
+
+class OpProtoHolder(object):
+    @classmethod
+    def instance(cls):
+        if not hasattr(cls, '_instance'):
+            cls._instance = cls()
+        return cls._instance
+
+    def __init__(self):
+        assert not hasattr(
+            self.__class__,
+            '_instance'), 'Please use `instance()` to get OpProtoHolder opject!'
+        op_protos = get_all_op_protos()
+        self.op_proto_map = {}
+        for proto in op_protos:
+            sefl.op_proto_map[proto.type] = proto
+
+    def get_op_proto(self, type):
+        assert type in self.op_proto_map, "Operator with type \"%s\" has not been registered." % type
+        return self.op_proto_map[type]
+
+
 class Variable(object):
     def __init__(self, block, name=None, shape=None, dtype=None,
                  lod_level=None):
@@ -46,14 +81,13 @@ class Operator(object):
         self.block = block
         self.proto = proto
         if type is not None:
-            # TODO.
-            pass
+            self.proto.set_type(type)
         if inputs is not None:
-            # TODO
-            pass
+            for k, v in inputs.iteritems():
+                self.proto.set_input(k, v)
         if outputs is not None:
-            # TODO
-            pass
+            for k, v in outputs.iteritems():
+                self.proto.set_output(k, v)
         if attrs is not None:
             # TODO
             pass