/*
* 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.
*/
package org.apache.cassandra.db.index.keys;
import java.nio.ByteBuffer;
import java.util.Set;
import org.apache.cassandra.db.ColumnFamily;
import org.apache.cassandra.db.Column;
import org.apache.cassandra.db.index.AbstractSimplePerColumnSecondaryIndex;
import org.apache.cassandra.db.index.SecondaryIndexSearcher;
import org.apache.cassandra.db.marshal.AbstractType;
import org.apache.cassandra.exceptions.ConfigurationException;
/**
* Implements a secondary index for a column family using a second column family.
* The design uses inverted index http://en.wikipedia.org/wiki/Inverted_index.
* The row key is the indexed value. For example, if we're indexing a column named
* city, the index value of city is the row key.
* The column names are the keys of the records. To see a detailed example, please
* refer to wikipedia.
*/
public class KeysIndex extends AbstractSimplePerColumnSecondaryIndex
{
protected ByteBuffer getIndexedValue(ByteBuffer rowKey, Column column)
{
return column.value();
}
protected ByteBuffer makeIndexColumnName(ByteBuffer rowKey, Column column)
{
return rowKey;
}
public SecondaryIndexSearcher createSecondaryIndexSearcher(Set<ByteBuffer> columns)
{
return new KeysSearcher(baseCfs.indexManager, columns);
}
public boolean isIndexEntryStale(ByteBuffer indexedValue, ColumnFamily data, long now)
{
Column liveColumn = data.getColumn(columnDef.name);
if (liveColumn == null || liveColumn.isMarkedForDelete(now))
return true;
ByteBuffer liveValue = liveColumn.value();
return columnDef.getValidator().compare(indexedValue, liveValue) != 0;
}
public void validateOptions() throws ConfigurationException
{
// no options used
}
protected AbstractType getExpressionComparator()
{
return baseCfs.getComparator();
}
}