Added SQLAlchemy Code to OpaqueData

Added the ORM code to be able to persist OpaqueData in a database.
This added the code to the base class ManagedObject as well. Unit
tests are added to demonstrate the code is working correctly.

kmip/pie/sqltypes.py

@@ -0,0 +1,121 @@
+# Copyright (c) 2016 The Johns Hopkins University/Applied Physics Laboratory
+# All Rights Reserved.
+#
+# 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 kmip.core import enums
+from sqlalchemy import Column, ForeignKey, Integer, String
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.orm import relationship
+
+import sqlalchemy.types as types
+
+
+Base = declarative_base()
+
+
+def attribute_append_factory(index_attribute):
+    def attribute_append(list_container, list_attribute, initiator):
+        index = getattr(list_container, index_attribute)
+        list_attribute.index = index
+        setattr(list_container, index_attribute, index + 1)
+        return list_attribute
+    return attribute_append
+
+
+class EnumType(types.TypeDecorator):
+    """
+    Converts a Python enum to an integer before storing it in the database.
+    This also does the reverse of converting an integer into an enum object.
+    This allows enums to be stored in a database.
+    """
+
+    impl = types.Integer
+
+    def __init__(self, cls):
+        """
+        Create a new EnumType. This new EnumType requires a class object in the
+        constructor. The class is used to construct new instances of the Enum
+        when the integer value is retrieved from the database.
+
+        Args:
+            cls(class): An Enum class used to create new instances from integer
+                values.
+        """
+        super(EnumType, self).__init__()
+        self._cls = cls
+
+    def process_bind_param(self, value, dialect):
+        """
+        Returns the integer value of the Enum. This value is stored in the
+        database.
+
+        Args:
+            value(Enum): An Enum instance whose integer value is to be stored.
+            dialect(string): SQL dialect
+        """
+        return value.value
+
+    def process_result_value(self, value, dialect):
+        """
+        Returns a new Enum representing the value stored in the database. The
+        Enum class type of the returned object is that of the cls parameter in
+        the __init__ call.
+
+        Args:
+            value(int): The integer value stored in the database that is used
+                to create the Enum
+            dialect(string): SQL dialect
+        """
+        return self._cls(value)
+
+
+class ManagedObjectName(Base):
+
+    __tablename__ = 'managed_object_names'
+    id = Column('id', Integer, primary_key=True)
+    mo_uid = Column('mo_uid', Integer, ForeignKey('managed_objects.uid'))
+    name = Column('name', String)
+    index = Column('name_index', Integer)
+    name_type = Column('name_type', EnumType(enums.NameType))
+
+    mo = relationship('ManagedObject', back_populates='_names')
+
+    def __init__(self, name, index=0,
+                 name_type=enums.NameType.UNINTERPRETED_TEXT_STRING):
+        self.name = name
+        self.index = index
+        self.name_type = name_type
+
+    def __repr__(self):
+        return ("<ManagedObjectName(name='%s', index='%d', type='%s')>" %
+                (self.name, self.index, self.name_type))
+
+    def __eq__(self, other):
+        if isinstance(other, ManagedObjectName):
+            if self.name != other.name:
+                return False
+            elif self.index != other.index:
+                return False
+            elif self.name_type != other.name_type:
+                return False
+            else:
+                return True
+        else:
+            return NotImplemented
+
+    def __ne__(self, other):
+        if isinstance(other, ManagedObjectName):
+            return not (self == other)
+        else:
+            return NotImplemented