IndexInfo.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;

namespace Deveel.Data.Sql {
    public sealed class IndexInfo {
        public IndexInfo(string indexName, string indexType, string[] columnNames) 
            : this(indexName, indexType, columnNames, false) {
        }

        public IndexInfo(string indexName, string indexType, string[] columnNames, bool isUnique, int offset) {
            if (String.IsNullOrEmpty(indexType))
                throw new ArgumentNullException("indexType");
            if (String.IsNullOrEmpty(indexName))
                throw new ArgumentNullException("indexName");
            if (columnNames == null || columnNames.Length == 0)
                throw new ArgumentNullException("columnNames");

            IndexName = indexName;
            IndexType = indexType;
            ColumnNames = columnNames;
            IsUnique = isUnique;
            Offset = offset;
        }

        public IndexInfo(string indexName, string indexType, string[] columnNames, bool isUnique)
            : this(indexName, indexType, columnNames, isUnique, -1) {
        }

        public string IndexName { get; private set; }

        public string IndexType { get; private set; }

        public string[] ColumnNames { get; private set; }

        public bool IsUnique { get; private set; }

        public int Offset { get; internal set; }

        internal void SerializeTo(Stream stream) {
            var writer = new BinaryWriter(stream, Encoding.Unicode);
            writer.Write(2);        // Version
            writer.Write(IndexType);
            writer.Write(IndexName);
            writer.Write(IsUnique ? (byte) 1 : (byte) 0);
            writer.Write(Offset);

            var colCount = ColumnNames.Length;
            writer.Write(colCount);
            for (int i = 0; i < colCount; i++) {
                var colName = ColumnNames[i];
                writer.Write(colName);
            }
        }

        internal static IndexInfo DeserializeFrom(Stream stream) {
            var reader = new BinaryReader(stream, Encoding.Unicode);

            var version = reader.ReadInt32();
            if (version != 2)
                throw new FormatException("Invalid version number for Index-Info");

            var indexType = reader.ReadString();
            var indexName = reader.ReadString();
            var unique = reader.ReadByte() == 1;
            var offset = reader.ReadInt32();

            var colCount = reader.ReadInt32();

            var columnNames = new string[colCount];
            for (int i = 0; i < colCount; i++) {
                var columnName = reader.ReadString();
                columnNames[i] = columnName;
            }

            return new IndexInfo(indexName, indexType, columnNames, unique, offset);
        }
    }
}