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This module bridges Table/SQL API and runtime. It contains
all resources that are required during pre-flight and runtime
phase. The content of this module is work-in-progress. It will
replace flink-table-planner once it is stable. See FLINK-11439
and FLIP-32 for more details.
/*
* 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.aggfunctions;
import org.apache.flink.annotation.Internal;
import org.apache.flink.table.api.DataTypes;
import org.apache.flink.table.data.GenericRowData;
import org.apache.flink.table.data.RowData;
import org.apache.flink.table.data.StringData;
import org.apache.flink.table.data.binary.BinaryStringData;
import org.apache.flink.table.runtime.functions.aggregate.BuiltInAggregateFunction;
import org.apache.flink.table.types.DataType;
import org.apache.flink.table.types.logical.LogicalType;
import java.util.Collections;
import java.util.List;
import static org.apache.flink.table.types.utils.DataTypeUtils.toInternalDataType;
/** Built-in LAST_VALUE aggregate function. */
@Internal
public final class LastValueAggFunction extends BuiltInAggregateFunction {
private transient DataType valueDataType;
public LastValueAggFunction(LogicalType valueType) {
this.valueDataType = toInternalDataType(valueType);
}
// --------------------------------------------------------------------------------------------
// Planning
// --------------------------------------------------------------------------------------------
@Override
public List getArgumentDataTypes() {
return Collections.singletonList(valueDataType);
}
@Override
public DataType getAccumulatorDataType() {
return DataTypes.ROW(
DataTypes.FIELD("lastValue", valueDataType.nullable()),
DataTypes.FIELD("lastOrder", DataTypes.BIGINT()))
.bridgedTo(RowData.class);
}
@Override
public DataType getOutputDataType() {
return valueDataType;
}
@Override
public boolean isDeterministic() {
return false;
}
// --------------------------------------------------------------------------------------------
// Runtime
// --------------------------------------------------------------------------------------------
@Override
public RowData createAccumulator() {
GenericRowData acc = new GenericRowData(2);
acc.setField(0, null);
acc.setField(1, Long.MIN_VALUE);
return acc;
}
public void accumulate(RowData rowData, Object value) {
GenericRowData acc = (GenericRowData) rowData;
if (value != null) {
acc.setField(0, value);
}
}
public void accumulate(RowData rowData, Object value, Long order) {
GenericRowData acc = (GenericRowData) rowData;
if (value != null && acc.getLong(1) < order) {
acc.setField(0, value);
acc.setField(1, order);
}
}
public void accumulate(GenericRowData acc, StringData value) {
if (value != null) {
accumulate(acc, (Object) ((BinaryStringData) value).copy());
}
}
public void accumulate(GenericRowData acc, StringData value, Long order) {
if (value != null) {
accumulate(acc, (Object) ((BinaryStringData) value).copy(), order);
}
}
public void resetAccumulator(RowData rowData) {
GenericRowData acc = (GenericRowData) rowData;
acc.setField(0, null);
acc.setField(1, Long.MIN_VALUE);
}
@SuppressWarnings("unchecked")
@Override
public T getValue(RowData rowData) {
GenericRowData acc = (GenericRowData) rowData;
return (T) acc.getField(0);
}
}