/**
* 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.tajo.engine.planner.physical;
import org.apache.tajo.worker.TaskAttemptContext;
import org.apache.tajo.engine.eval.EvalContext;
import org.apache.tajo.engine.eval.EvalNode;
import org.apache.tajo.engine.planner.logical.SelectionNode;
import org.apache.tajo.storage.RowStoreUtil;
import org.apache.tajo.storage.Tuple;
import org.apache.tajo.storage.VTuple;
import java.io.IOException;
public class SelectionExec extends UnaryPhysicalExec {
private final EvalNode qual;
private final EvalContext qualCtx;
private final Tuple outputTuple;
// projection
private int [] targetIds;
public SelectionExec(TaskAttemptContext context,
SelectionNode plan,
PhysicalExec child) {
super(context, plan.getInSchema(), plan.getOutSchema(), child);
this.qual = plan.getQual();
this.qualCtx = this.qual.newContext();
// for projection
if (!inSchema.equals(outSchema)) {
targetIds = RowStoreUtil.getTargetIds(inSchema, outSchema);
}
this.outputTuple = new VTuple(outSchema.getColumnNum());
}
@Override
public Tuple next() throws IOException {
Tuple tuple;
while ((tuple = child.next()) != null) {
qual.eval(qualCtx, inSchema, tuple);
if (qual.terminate(qualCtx).asBool()) {
if (targetIds != null) {
RowStoreUtil.project(tuple, outputTuple, targetIds);
return outputTuple;
} else {
return tuple;
}
}
}
return null;
}
}