QueryType.cs

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// 
//  Copyright 2010-2015 Deveel
// 
//    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.
//

using System;
using System.IO;
using System.Text;

using Deveel.Data.Serialization;
using Deveel.Data.Sql.Objects;
using Deveel.Data.Sql.Query;

namespace Deveel.Data.Types {
    [Serializable]
    public sealed class QueryType : SqlType {
        public QueryType()
            : base("QUERY", SqlTypeCode.QueryPlan) {
        }

        private QueryType(ObjectData data)
            : base(data) {
        }

        public override bool IsIndexable {
            get { return false; }
        }

        public override bool IsStorable {
            get { return false; }
        }

        public override ISqlObject DeserializeObject(Stream stream) {
            var reader = new BinaryReader(stream, Encoding.Unicode);
            var isNull = reader.ReadByte() == 0;
            if (isNull)
                return SqlQueryObject.Null;

            var nodeTypeString = reader.ReadString();
            var nodeType = Type.GetType(nodeTypeString, true);
            var queryPlan = DeserializePlan(nodeType, reader);

            return new SqlQueryObject(queryPlan);
        }

        private static IQueryPlanNode DeserializePlan(Type nodeType, BinaryReader reader) {
            var serializer = new BinarySerializer();
            return (IQueryPlanNode) serializer.Deserialize(reader, nodeType);
        }

        public override void SerializeObject(Stream stream, ISqlObject obj) {
            var writer = new BinaryWriter(stream, Encoding.Unicode);

            var queryPlanObj = (SqlQueryObject) obj;
            if (queryPlanObj.IsNull) {
                writer.Write((byte) 0);
            } else {
                writer.Write((byte)1);
                var nodeTypeString = queryPlanObj.QueryPlan.GetType().AssemblyQualifiedName;
                if (String.IsNullOrEmpty(nodeTypeString))
                    throw new InvalidOperationException();

                writer.Write(nodeTypeString);
                SerializePlan(queryPlanObj.QueryPlan, writer);
            }
        }

        private static void SerializePlan(IQueryPlanNode queryPlan, BinaryWriter writer) {
            var serializer = new BinarySerializer();
            serializer.Serialize(writer, queryPlan);
        }
    }
}