package org.apache.cassandra.db.filter;
/*
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 * 
 */


import java.nio.ByteBuffer;
import java.util.Comparator;
import java.util.Iterator;
import java.util.SortedSet;

import org.apache.cassandra.db.*;
import org.apache.cassandra.db.columniterator.IColumnIterator;
import org.apache.cassandra.db.columniterator.SSTableNamesIterator;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.io.sstable.SSTableReader;
import org.apache.cassandra.io.util.FileDataInput;
import org.apache.cassandra.utils.FBUtilities;

public class NamesQueryFilter implements IFilter
{
    public final SortedSet<ByteBuffer> columns;

    public NamesQueryFilter(SortedSet<ByteBuffer> columns)
    {
        this.columns = columns;
    }

    public NamesQueryFilter(ByteBuffer column)
    {
        this(FBUtilities.singleton(column));
    }

    public IColumnIterator getMemtableColumnIterator(ColumnFamily cf, DecoratedKey key, AbstractType comparator)
    {
        return Memtable.getNamesIterator(key, cf, this);
    }

    public IColumnIterator getSSTableColumnIterator(SSTableReader sstable, DecoratedKey key)
    {
        return new SSTableNamesIterator(sstable, key, columns);
    }
    
    public IColumnIterator getSSTableColumnIterator(SSTableReader sstable, FileDataInput file, DecoratedKey key)
    {
        return new SSTableNamesIterator(sstable, file, key, columns);
    }

    public SuperColumn filterSuperColumn(SuperColumn superColumn, int gcBefore)
    {
        for (IColumn column : superColumn.getSubColumns())
        {
            if (!columns.contains(column.name()) || !QueryFilter.isRelevant(column, superColumn, gcBefore))
            {
                superColumn.remove(column.name());
            }
        }
        return superColumn;
    }

    public void collectReducedColumns(IColumnContainer container, Iterator<IColumn> reducedColumns, int gcBefore)
    {
        while (reducedColumns.hasNext())
        {
            IColumn column = reducedColumns.next();
            if (QueryFilter.isRelevant(column, container, gcBefore))
                container.addColumn(column);
        }
    }

    public Comparator<IColumn> getColumnComparator(AbstractType comparator)
    {
        return comparator.columnComparator;
    }
}