/*
* 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.operation.merge;
import com.google.common.util.concurrent.ListenableFuture;
import io.crate.executor.transport.TransportActionProvider;
import io.crate.operation.DownstreamOperation;
import io.crate.operation.ImplementationSymbolVisitor;
import io.crate.operation.projectors.FlatProjectorChain;
import io.crate.operation.projectors.ProjectionToProjectorVisitor;
import io.crate.operation.projectors.Projector;
import io.crate.planner.node.dql.MergeNode;
import org.elasticsearch.cluster.ClusterService;
import org.elasticsearch.common.settings.Settings;
import java.util.concurrent.atomic.AtomicBoolean;
/**
* merge rows - that's it
*/
public class MergeOperation implements DownstreamOperation {
private final int numUpstreams;
private final FlatProjectorChain projectorChain;
private Projector downstream;
private AtomicBoolean wantMore = new AtomicBoolean(true);
public MergeOperation(ClusterService clusterService,
Settings settings,
TransportActionProvider transportActionProvider,
ImplementationSymbolVisitor symbolVisitor, MergeNode mergeNode) {
projectorChain = new FlatProjectorChain(mergeNode.projections(),
new ProjectionToProjectorVisitor(
clusterService,
settings,
transportActionProvider,
symbolVisitor)
);
downstream(projectorChain.firstProjector());
this.numUpstreams = mergeNode.numUpstreams();
projectorChain.startProjections();
}
public boolean addRows(Object[][] rows) throws Exception {
for (int i = 0, length = rows.length; i < length && wantMore.get(); i++) {
// assume that all projectors .setNextRow(...) methods are threadsafe
if (!downstream.setNextRow(rows[i])) {
wantMore.set(false);
}
}
return wantMore.get();
}
@Override
public int numUpstreams() {
return numUpstreams;
}
@Override
public void finished() {
downstream.upstreamFinished();
}
public ListenableFuture<Object[][]> result() {
return projectorChain.result();
}
@Override
public void downstream(Projector downstream) {
downstream.registerUpstream(this);
this.downstream = downstream;
}
@Override
public Projector downstream() {
return downstream;
}
}