ColumnInfo.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.Expressions;
using Deveel.Data.Types;

namespace Deveel.Data.Sql.Tables {
    [Serializable]
    public sealed class ColumnInfo : ISerializable {
        public ColumnInfo(string columnName, SqlType columnType) {
            if (String.IsNullOrEmpty(columnName))
                throw new ArgumentNullException("columnName");
            if (columnType == null) 
                throw new ArgumentNullException("columnType");


            ColumnType = columnType;
            ColumnName = columnName;
        }

        private ColumnInfo(ObjectData data) {
            ColumnName = data.GetString("ColumnName");
            ColumnType = data.GetValue<SqlType>("ColumnType");
            IsNotNull = data.GetBoolean("IsNotNull");
            DefaultExpression = data.GetValue<SqlExpression>("Default");
            IndexType = data.GetString("IndexType");
        }

        public TableInfo TableInfo { get; internal set; }

        public string ColumnName { get; private set; }

        public ObjectName FullColumnName {
            get { return TableInfo == null ? new ObjectName(ColumnName) : new ObjectName(TableInfo.TableName, ColumnName); }
        }

        public SqlType ColumnType { get; private set; }

        public int Offset {
            get { return TableInfo == null ? -1 : TableInfo.IndexOfColumn(ColumnName); }
        }

        public bool HasSize {
            get { return ColumnType is ISizeableType; }
        }

        public int Size {
            get {
                var sizeable = ColumnType as ISizeableType;
                return sizeable == null ? -1 : sizeable.Size;
            }
        }

        public bool HasScale {
            get { return ColumnType is NumericType; }
        }

        public int Scale {
            get {
                var numericType = ColumnType as NumericType;
                return numericType == null ? -1 : numericType.Scale;
            }
        }

        public bool IsIndexable {
            get { return ColumnType.IsIndexable; }
        }

        public bool IsNotNull { get; set; }

        public SqlExpression DefaultExpression { get; set; }

        public bool HasDefaultExpression {
            get { return DefaultExpression != null; }
        }

        public string IndexType { get; internal set; }


        void ISerializable.GetData(SerializeData data) {
            data.SetValue("ColumnName", ColumnName);
            data.SetValue("ColumnType", ColumnType);
            data.SetValue("IsNotNull", IsNotNull);
            data.SetValue("Default", DefaultExpression);
            data.SetValue("IndexType", IndexType);
        }


        public static void Serialize(ColumnInfo columnInfo, BinaryWriter writer) {
            writer.Write(3);    // Version
            writer.Write(columnInfo.ColumnName);

            TypeSerializer.SerializeTo(writer, columnInfo.ColumnType);

            writer.Write(columnInfo.IsNotNull ? (byte)1 : (byte)0);

            if (columnInfo.DefaultExpression != null) {
                writer.Write((byte)1);
                SqlExpression.Serialize(columnInfo.DefaultExpression, writer);
            } else {
                writer.Write((byte)0);
            }
        }

        public static void Serialize(ColumnInfo columnInfo, Stream stream, Encoding encoding) {
            var writer = new BinaryWriter(stream, encoding);
            Serialize(columnInfo, writer);
        }

        public static void Serialize(ColumnInfo columnInfo, Stream stream) {
            Serialize(columnInfo, stream, Encoding.Unicode);
        }

        public static ColumnInfo Deserialize(Stream stream, ITypeResolver typeResolver) {
            var reader = new BinaryReader(stream, Encoding.Unicode);
            return Deserialize(reader, typeResolver);
        }

        public static ColumnInfo Deserialize(BinaryReader reader, ITypeResolver typeResolver) {
            var version = reader.ReadInt32();
            if (version != 3)
                throw new FormatException("Invalid version of the Column-Info");

            var columnName = reader.ReadString();
            var columnType = TypeSerializer.Deserialize(reader, typeResolver);

            var notNull = reader.ReadByte() == 1;

            var columnInfo = new ColumnInfo(columnName, columnType);
            columnInfo.IsNotNull = notNull;

            var hasDefault = reader.ReadByte() == 1;
            if (hasDefault)
                columnInfo.DefaultExpression = SqlExpression.Deserialize(reader);

            return columnInfo;
        }
    }
}