QueryLogTransformer.java

/*
 * Copyright 2013 Eediom Inc.
 * 
 * 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.
 */
package org.araqne.logdb.logapi;

import java.util.List;
import java.util.Map;

import org.araqne.log.api.Log;
import org.araqne.log.api.LogTransformer;
import org.araqne.log.api.LogTransformerFactory;
import org.araqne.log.api.SimpleLog;
import org.araqne.logdb.QueryCommand;
import org.araqne.logdb.QueryCommandPipe;
import org.araqne.logdb.Row;

/**
 * @since 1.7.8
 * @author xeraph
 * 
 */
public class QueryLogTransformer extends QueryCommand implements LogTransformer {
	private final LogTransformerFactory factory;
	private QueryCommand first;
	private Map<String, Object> last;

	public QueryLogTransformer(LogTransformerFactory factory, List<QueryCommand> commands) {
		this.factory = factory;

		first = commands.get(0);
		commands.add(this);

		for (int i = commands.size() - 2; i >= 0; i--)
			commands.get(i).setOutput(new QueryCommandPipe(commands.get(i + 1)));
	}

	@Override
	public String getName() {
		return "querylogtransformer";
	}

	@Override
	public LogTransformerFactory getTransformerFactory() {
		return factory;
	}

	@Override
	public Log transform(Log log) {
		Map<String, Object> c = Row.clone(log.getParams());
		c.put("_time", log.getDate());

		first.onPush(new Row(c));
		Map<String, Object> m = last;
		last = null;

		return m == null ? null : new SimpleLog(log.getDate(), log.getLoggerName(), m);
	}

	@Override
	public void onPush(Row m) {
		last = m.map();
	}
}