Java tutorial
/* * Licensed to CRATE Technology GmbH ("Crate") under one or more contributor * license agreements. See the NOTICE file distributed with this work for * additional information regarding copyright ownership. Crate 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. * * However, if you have executed another commercial license agreement * with Crate these terms will supersede the license and you may use the * software solely pursuant to the terms of the relevant commercial agreement. */ package io.crate.executor.task.join; import com.google.common.base.Optional; import com.google.common.util.concurrent.Futures; import com.google.common.util.concurrent.ListenableFuture; import com.google.common.util.concurrent.SettableFuture; import io.crate.breaker.RamAccountingContext; import io.crate.core.concurrent.ForwardingFutureCallback; import io.crate.executor.*; import io.crate.operation.join.NestedLoopOperation; import io.crate.operation.projectors.ProjectionToProjectorVisitor; import io.crate.planner.node.dql.join.NestedLoopNode; import org.elasticsearch.common.breaker.CircuitBreaker; import java.util.Arrays; import java.util.List; import java.util.Locale; import java.util.UUID; public class NestedLoopTask extends JobTask implements PageableTask { private NestedLoopOperation operation; private final SettableFuture<TaskResult> result = SettableFuture.create(); private final List<ListenableFuture<TaskResult>> results = Arrays.<ListenableFuture<TaskResult>>asList(result); public NestedLoopTask(UUID jobId, String nodeId, NestedLoopNode nestedLoopNode, List<Task> outerTasks, List<Task> innerTasks, TaskExecutor executor, ProjectionToProjectorVisitor projectionToProjectorVisitor, CircuitBreaker circuitBreaker) { super(jobId); String ramContextId = String.format(Locale.ENGLISH, "%s: %s", nodeId, jobId.toString()); RamAccountingContext ramAccountingContext = new RamAccountingContext(ramContextId, circuitBreaker); operation = new NestedLoopOperation(nestedLoopNode, outerTasks, innerTasks, executor, projectionToProjectorVisitor, ramAccountingContext); } @Override public void start(PageInfo pageInfo) { Futures.addCallback(operation.execute(Optional.of(pageInfo)), new ForwardingFutureCallback<>(result)); } @Override public void start() { Futures.addCallback(operation.execute(Optional.<PageInfo>absent()), new ForwardingFutureCallback<>(result)); } @Override public List<ListenableFuture<TaskResult>> result() { return results; } @Override public void upstreamResult(List<ListenableFuture<TaskResult>> result) { // ignore } }