TransportJRMgmBaseAction.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2012 Red Hat Inc. and/or its affiliates and other contributors
 * as indicated by the @authors tag. All rights reserved.
 */
package org.jboss.elasticsearch.river.remote.mgm;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicReferenceArray;

import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.action.support.nodes.TransportNodesOperationAction;
import org.elasticsearch.cluster.ClusterName;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.inject.Inject;
import org.elasticsearch.common.logging.ESLogger;
import org.elasticsearch.common.logging.Loggers;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.TransportService;
import org.jboss.elasticsearch.river.remote.IRiverMgm;
import org.jboss.elasticsearch.river.remote.RemoteRiver;

/**
 * Base abstract transport action for Remote River management operations.
 * 
 * @author Vlastimil Elias (velias at redhat dot com)
 */
@SuppressWarnings("rawtypes")
public abstract class TransportJRMgmBaseAction<Request extends JRMgmBaseRequest, Response extends JRMgmBaseResponse, NodeRequest extends NodeJRMgmBaseRequest<Request>, NodeResponse extends NodeJRMgmBaseResponse>
		extends TransportNodesOperationAction<Request, Response, NodeRequest, NodeResponse> {

	protected final ESLogger logger;

	@Inject
	public TransportJRMgmBaseAction(Settings settings, String actionName, ClusterName clusterName, ThreadPool threadPool,
			ClusterService clusterService, TransportService transportService, ActionFilters actionFilters) {
		super(settings, actionName, clusterName, threadPool, clusterService, transportService, actionFilters);
		logger = Loggers.getLogger(getClass());
	}

	@Override
	protected String executor() {
		return ThreadPool.Names.MANAGEMENT;
	}

	@SuppressWarnings("unchecked")
	@Override
	protected Response newResponse(Request request, AtomicReferenceArray responses) {
		final List<NodeResponse> nodesInfos = new ArrayList<NodeResponse>();
		for (int i = 0; i < responses.length(); i++) {
			Object resp = responses.get(i);
			if (resp instanceof NodeJRMgmBaseResponse) {
				nodesInfos.add((NodeResponse) resp);
			}
		}
		return newResponse(clusterName, nodesInfos.toArray(newNodeResponseArray(nodesInfos.size())));
	}

	protected abstract NodeResponse[] newNodeResponseArray(int len);

	protected abstract Response newResponse(ClusterName clusterName, NodeResponse[] array);

	@Override
	protected boolean accumulateExceptions() {
		return false;
	}

	@Override
	protected NodeResponse nodeOperation(NodeRequest nodeRequest) throws ElasticsearchException {
		Request req = nodeRequest.getRequest();
		logger.debug("Go to look for river '{}' on this node", req.getRiverName());
		IRiverMgm river = RemoteRiver.getRunningInstance(req.getRiverName());
		if (river == null) {
			logger.debug("River {} not found on this node", req.getRiverName());
			return newNodeResponse();
		} else {
			logger.debug("River {} found on this node, go to call mgm operation on it {}", req.getRiverName(), req);
			try {
				return performOperationOnRiver(river, req, clusterService.localNode());
			} catch (Exception e) {
				throw new ElasticsearchException(e.getMessage(), e);
			}
		}
	}

	/**
	 * Implement in subclass to perform necessary management operation on the river instance. This method is called only
	 * on node where river really runs.
	 * 
	 * @param river instance to perform operation on, never null
	 * @param req request for operation to process
	 * @param node this operation runs on (used to construct response etc.)
	 * @return node response with operation result
	 * @throws Exception if something is wrong
	 */
	protected abstract NodeResponse performOperationOnRiver(IRiverMgm river, Request req, DiscoveryNode node)
			throws Exception;
}