/*
* 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;
import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import io.crate.executor.QueryResult;
import io.crate.executor.Task;
import io.crate.executor.TaskResult;
import io.crate.operation.collect.CollectOperation;
import io.crate.planner.node.dql.CollectNode;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.ArrayList;
import java.util.List;
/**
* A collect task which returns one future and runs a collectOperation locally and synchronous
*/
public class LocalCollectTask implements Task<QueryResult> {
private final CollectNode collectNode;
private final CollectOperation collectOperation;
private final List<ListenableFuture<QueryResult>> resultList;
private final SettableFuture<QueryResult> result;
public LocalCollectTask(CollectOperation<Object[][]> collectOperation, CollectNode collectNode) {
this.collectNode = collectNode;
this.collectOperation = collectOperation;
this.resultList = new ArrayList<>(1);
this.result = SettableFuture.create();
resultList.add(result);
}
@Override
public void start() {
Futures.addCallback(collectOperation.collect(collectNode), new FutureCallback<Object[][]>() {
@Override
public void onSuccess(@Nullable Object[][] rows) {
result.set(new QueryResult(rows));
}
@Override
public void onFailure(@Nonnull Throwable t) {
result.setException(t);
}
});
}
@Override
public List<ListenableFuture<QueryResult>> result() {
return resultList;
}
@Override
public void upstreamResult(List<ListenableFuture<TaskResult>> result) {
// ignored, comes always first
}
}