/*
* 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 org.apache.tinkerpop.gremlin.server.handler;
import org.apache.tinkerpop.gremlin.driver.message.RequestMessage;
import org.apache.tinkerpop.gremlin.driver.message.ResponseMessage;
import org.apache.tinkerpop.gremlin.driver.message.ResponseStatusCode;
import org.apache.tinkerpop.gremlin.groovy.engine.GremlinExecutor;
import org.apache.tinkerpop.gremlin.server.Context;
import org.apache.tinkerpop.gremlin.server.GraphManager;
import org.apache.tinkerpop.gremlin.server.OpProcessor;
import org.apache.tinkerpop.gremlin.server.Settings;
import org.apache.tinkerpop.gremlin.server.op.OpLoader;
import org.apache.tinkerpop.gremlin.server.op.OpProcessorException;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageDecoder;
import org.javatuples.Pair;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.List;
import java.util.Optional;
import java.util.concurrent.ScheduledExecutorService;
/**
* @author Stephen Mallette (http://stephen.genoprime.com)
*/
@ChannelHandler.Sharable
public class OpSelectorHandler extends MessageToMessageDecoder<RequestMessage> {
private static final Logger logger = LoggerFactory.getLogger(OpSelectorHandler.class);
private final Settings settings;
private final GraphManager graphManager;
private final GremlinExecutor gremlinExecutor;
private final ScheduledExecutorService scheduledExecutorService;
public OpSelectorHandler(final Settings settings, final GraphManager graphManager, final GremlinExecutor gremlinExecutor,
final ScheduledExecutorService scheduledExecutorService) {
this.settings = settings;
this.graphManager = graphManager;
this.gremlinExecutor = gremlinExecutor;
this.scheduledExecutorService = scheduledExecutorService;
}
@Override
protected void decode(final ChannelHandlerContext ctx, final RequestMessage msg,
final List<Object> objects) throws Exception {
final Context gremlinServerContext = new Context(msg, ctx, settings,
graphManager, gremlinExecutor, this.scheduledExecutorService);
try {
// choose a processor to do the work based on the request message.
final Optional<OpProcessor> processor = OpLoader.getProcessor(msg.getProcessor());
if (processor.isPresent())
// the processor is known so use it to evaluate the message
objects.add(Pair.with(msg, processor.get().select(gremlinServerContext)));
else {
// invalid op processor selected so write back an error by way of OpProcessorException.
final String errorMessage = String.format("Invalid OpProcessor requested [%s]", msg.getProcessor());
throw new OpProcessorException(errorMessage, ResponseMessage.build(msg)
.code(ResponseStatusCode.REQUEST_ERROR_INVALID_REQUEST_ARGUMENTS)
.statusMessage(errorMessage).create());
}
} catch (OpProcessorException ope) {
logger.warn(ope.getMessage(), ope);
ctx.writeAndFlush(ope.getResponseMessage());
}
}
}