BaseFilterIterator.java

/*
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */
package org.teiid.translator.accumulo;

import java.io.IOException;
import java.util.Arrays;
import java.util.Map;

import org.apache.accumulo.core.data.Key;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.iterators.IteratorEnvironment;
import org.apache.accumulo.core.iterators.SortedKeyValueIterator;
import org.apache.accumulo.core.iterators.conf.ColumnSet;
import org.apache.accumulo.core.iterators.user.RowFilter;

/**
 * Base class for Filters
 */
public abstract class BaseFilterIterator extends RowFilter {
	public static final String NEGATE = "NEGATE"; //$NON-NLS-1$
	protected AccumuloMetadataProcessor.ValueIn valueIn;
	protected ColumnSet columnFilter;
	private boolean negate = false; 

	@Override
	public void init(SortedKeyValueIterator<Key, Value> source,
			Map<String, String> options, IteratorEnvironment env)
			throws IOException {
		super.init(source, options, env);

		String cf = options.get(AccumuloMetadataProcessor.CF);
		String cq = options.get(AccumuloMetadataProcessor.CQ);

		if (options.get(AccumuloMetadataProcessor.VALUE_IN) != null) {
			String value = options.get(AccumuloMetadataProcessor.VALUE_IN);
			this.valueIn = AccumuloMetadataProcessor.ValueIn.valueOf(value.substring(1, value.length()-1));
		} else {
			this.valueIn = AccumuloMetadataProcessor.ValueIn.VALUE;
		}

		if (cq != null) {
			this.columnFilter = new ColumnSet(Arrays.asList(cf + ":" + cq)); //$NON-NLS-1$
		} else {
			this.columnFilter = new ColumnSet(Arrays.asList(cf));
		}

		this.negate = false;
	    if (options.get(NEGATE) != null) {
	      this.negate = Boolean.parseBoolean(options.get(NEGATE));
	    }
	}

	@Override
	public SortedKeyValueIterator<Key, Value> deepCopy(IteratorEnvironment env) {
		BaseFilterIterator instance = (BaseFilterIterator) super.deepCopy(env);
		instance.valueIn = this.valueIn;
		instance.columnFilter = this.columnFilter;
		return instance;
	}

	@Override
	public boolean acceptRow(SortedKeyValueIterator<Key,Value> rowItem) throws IOException {
		if (this.negate) {
			return !accept(rowItem);
		}
		return accept(rowItem);
	}
	
	private boolean accept(SortedKeyValueIterator<Key,Value> rowItem) {
		while(rowItem.hasTop()) {
			Key key = rowItem.getTopKey();
			if (this.columnFilter.contains(key)) {
				byte[] value;
				if (this.valueIn.equals(AccumuloMetadataProcessor.ValueIn.VALUE)) {
					value = rowItem.getTopValue().get();
				}
				else {
					value = key.getColumnQualifier().getBytes();
				}
				return accept(value);
			}
		}
		return true;
	}

	@SuppressWarnings("unused")
	public boolean accept(byte[] value) {
		return true;
	}	
}