org.apache.flink.table.planner.functions.tablefunctions.ReplicateRows Maven / Gradle / Ivy
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* 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.flink.table.planner.functions.tablefunctions;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.table.functions.TableFunction;
import org.apache.flink.types.Row;
import static org.apache.flink.util.Preconditions.checkArgument;
/**
* Replicate the row N times. N is specified as the first argument to the function. This is an
* internal function solely used by optimizer to rewrite EXCEPT ALL AND INTERSECT ALL queries.
*/
public class ReplicateRows extends TableFunction {
private static final long serialVersionUID = 1L;
private final TypeInformation[] fieldTypes;
private transient Row reuseRow;
public ReplicateRows(TypeInformation[] fieldTypes) {
this.fieldTypes = fieldTypes;
}
public void eval(Object... inputs) {
checkArgument(inputs.length == fieldTypes.length + 1);
long numRows = (long) inputs[0];
if (reuseRow == null) {
reuseRow = new Row(fieldTypes.length);
}
for (int i = 0; i < fieldTypes.length; i++) {
reuseRow.setField(i, inputs[i + 1]);
}
for (int i = 0; i < numRows; i++) {
collect(reuseRow);
}
}
@Override
public TypeInformation getResultType() {
return new RowTypeInfo(fieldTypes);
}
@Override
public TypeInformation[] getParameterTypes(Class[] signature) {
TypeInformation[] paraTypes = new TypeInformation[1 + fieldTypes.length];
paraTypes[0] = Types.LONG;
System.arraycopy(fieldTypes, 0, paraTypes, 1, fieldTypes.length);
return paraTypes;
}
}