WhileMatchFilter.java

/*
 * Copyright 2009 The Apache Software Foundation
 *
 * 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 meetup.beeno.filter;

import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.filter.Filter;

import java.io.DataOutput;
import java.io.IOException;
import java.io.DataInput;

/**
 * A wrapper filter that filters everything after the first filtered row.
 */
public class WhileMatchFilter implements Filter {
	private boolean filterAllRemaining = false;
	private Filter filter;

	public WhileMatchFilter() {
		super();
	}

	public WhileMatchFilter( Filter filter ) {
		this.filter = filter;
	}

	public void reset() {
		// no state.
	}

	private void changeFAR( boolean value ) {
		filterAllRemaining = filterAllRemaining || value;
	}

	public boolean filterRowKey( byte[] buffer, int offset, int length ) {
		changeFAR(filter.filterRowKey(buffer, offset, length));
		return filterAllRemaining();
	}

	public boolean filterAllRemaining() {
		return this.filterAllRemaining || this.filter.filterAllRemaining();
	}

	public ReturnCode filterKeyValue( KeyValue v ) {
		return filter.filterKeyValue(v);
	}

	public boolean filterRow() {
		changeFAR(filter.filterRow());
		return filterAllRemaining();
	}

	public void write( DataOutput out ) throws IOException {
		out.writeUTF(this.filter.getClass().getName());
		this.filter.write(out);
	}

	public void readFields( DataInput in ) throws IOException {
		String className = in.readUTF();
		try {
			this.filter = (Filter) (Class.forName(className).newInstance());
			this.filter.readFields(in);
		}
		catch (InstantiationException e) {
			throw new RuntimeException("Failed deserialize.", e);
		}
		catch (IllegalAccessException e) {
			throw new RuntimeException("Failed deserialize.", e);
		}
		catch (ClassNotFoundException e) {
			throw new RuntimeException("Failed deserialize.", e);
		}
	}
}