/**
* Copyright (c) 2002-2011 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.smack.pipeline.core;
import org.apache.log4j.Logger;
import org.neo4j.graphdb.GraphDatabaseService;
import org.neo4j.smack.pipeline.core.event.CorePipelineEvent;
import org.neo4j.smack.pipeline.database.DatabaseWorkPipeline;
import org.neo4j.smack.pipeline.database.ThreadTransactionManagement;
import org.neo4j.smack.pipeline.database.TransactionRegistry;
import com.lmax.disruptor.ExceptionHandler;
import com.lmax.disruptor.WorkHandler;
/**
* Takes a prepared RequestEvent, packages it into DatabaseWork, and
* assigns that work to a worker based on the connection ID (same connection
* always goes to the same worker).
*/
public class WorkDivisionHandler implements WorkHandler<CorePipelineEvent> {
private final static Logger logger = Logger.getLogger(WorkDivisionHandler.class);
private static final int NUM_DATABASE_WORK_EXECUTORS = 4;
private final GraphDatabaseService database;
private final DatabaseWorkPipeline[] workers = new DatabaseWorkPipeline[NUM_DATABASE_WORK_EXECUTORS];
private final ExceptionHandler exceptionHandler;
public WorkDivisionHandler(GraphDatabaseService database, ExceptionHandler exceptionHandler) {
this.database = database;
this.exceptionHandler = exceptionHandler;
start();
}
@Override
public void onEvent(CorePipelineEvent event)
{
int workerId = (int) (event.getConnectionId() % NUM_DATABASE_WORK_EXECUTORS);
workers[workerId].addWork(event);
}
public void stop() {
for (DatabaseWorkPipeline worker : workers) {
stopWorker(worker);
}
}
private void start() {
for (int i = 0; i < NUM_DATABASE_WORK_EXECUTORS; i++) {
TransactionRegistry txs = new TransactionRegistry(database);
ThreadTransactionManagement txManage = new ThreadTransactionManagement(txs);
DatabaseWorkPipeline worker = new DatabaseWorkPipeline(database, txs, txManage, exceptionHandler);
workers[i] = worker;
worker.start();
}
}
private void stopWorker(DatabaseWorkPipeline worker) {
try {
if (worker == null) {
logger.warn("Worker is null");
return;
}
worker.stop();
} catch (Exception e) {
logger.error("Error stopping worker", e);
}
}
}