FilterTable.cs

Go to the documentation of this file.

// 
//  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.Collections.Generic;

using Deveel.Data.Index;

namespace Deveel.Data.Sql.Tables {
    class FilterTable : Table {
        private ColumnIndex[] columnIndices;

        public FilterTable(ITable parent) {
            Parent = parent;
        }

        protected ITable Parent { get; private set; }

        public override IEnumerator<Row> GetEnumerator() {
            return Parent.GetEnumerator();
        }

        public override IContext Context {
            get { return Parent.Context; }
        }

        public override TableInfo TableInfo {
            get { return Parent.TableInfo; }
        }

        public override int RowCount {
            get { return Parent.RowCount; }
        }

        public override void Lock() {
            Parent.Lock();
        }

        public override void Release() {
            Parent.Release();
        }

        protected override RawTableInfo GetRawTableInfo(RawTableInfo rootInfo) {
            return Parent.GetRawTableInfo(rootInfo);
        }

        protected override ColumnIndex GetIndex(int column, int originalColumn, ITable table) {
            if (columnIndices == null) {
                columnIndices = new ColumnIndex[Parent.ColumnCount()];
            }

            // Is there a local index available?
            var index = columnIndices[column];
            if (index == null) {
                // If we are asking for the index of this table we must
                // tell the parent we are looking for its index.
                var t = table;
                if (table == this)
                    t = Parent;

                // Index is not cached in this table so ask the parent.
                index = Parent.GetIndex(column, originalColumn, t);
                if (table == this)
                    columnIndices[column] = index;

            } else {
                // If this has a cached scheme and we are in the correct domain then
                // return it.
                if (table == this)
                    return index;

                // Otherwise we must calculate the subset of the scheme
                return index.GetSubset(table, originalColumn);
            }

            return index;
        }

        protected override IEnumerable<int> ResolveRows(int column, IEnumerable<int> rowSet, ITable ancestor) {
            if (ancestor == this || ancestor == Parent)
                return rowSet;

            return Parent.ResolveRows(column, rowSet, ancestor);
        }

        public override DataObject GetValue(long rowNumber, int columnOffset) {
            return Parent.GetValue(rowNumber, columnOffset);
        }

        protected override ObjectName GetResolvedColumnName(int column) {
            return Parent.GetResolvedColumnName(column);
        }
    }
}