cshuo commented on a change in pull request #15747: URL: https://github.com/apache/flink/pull/15747#discussion_r619785598
########## File path: flink-table/flink-table-planner-blink/src/main/java/org/apache/flink/table/planner/functions/aggfunctions/LagAggFunction.java ########## @@ -0,0 +1,159 @@ +/* + * 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.api.common.typeutils.TypeSerializer; +import org.apache.flink.table.api.DataTypes; +import org.apache.flink.table.api.TableException; +import org.apache.flink.table.functions.AggregateFunction; +import org.apache.flink.table.runtime.functions.aggregate.BuiltInAggregateFunction; +import org.apache.flink.table.runtime.typeutils.InternalSerializers; +import org.apache.flink.table.runtime.typeutils.LinkedListSerializer; +import org.apache.flink.table.types.DataType; +import org.apache.flink.table.types.logical.LogicalType; +import org.apache.flink.table.types.logical.LogicalTypeRoot; +import org.apache.flink.table.types.utils.DataTypeUtils; + +import java.util.Arrays; +import java.util.LinkedList; +import java.util.List; +import java.util.Objects; + +/** Lag {@link AggregateFunction}. */ +public class LagAggFunction<T> extends BuiltInAggregateFunction<T, LagAggFunction.LagAcc<T>> { + + private final transient DataType[] valueDataTypes; + + @SuppressWarnings("unchecked") + public LagAggFunction(LogicalType[] valueTypes) { + this.valueDataTypes = + Arrays.stream(valueTypes) + .map(DataTypeUtils::toInternalDataType) + .toArray(DataType[]::new); + if (valueDataTypes.length == 3 + && valueDataTypes[2].getLogicalType().getTypeRoot() != LogicalTypeRoot.NULL) { + if (valueDataTypes[0].getConversionClass() != valueDataTypes[2].getConversionClass()) { + throw new TableException( + String.format( + "Please explicitly cast default value %s to %s.", + valueDataTypes[2], valueDataTypes[1])); + } + } + } + + // -------------------------------------------------------------------------------------------- + // Planning + // -------------------------------------------------------------------------------------------- + + @Override + public List<DataType> getArgumentDataTypes() { + return Arrays.asList(valueDataTypes); + } + + @Override + public DataType getAccumulatorDataType() { + return DataTypes.STRUCTURED( + LagAcc.class, + DataTypes.FIELD("offset", DataTypes.INT()), + DataTypes.FIELD("defaultValue", valueDataTypes[0]), + DataTypes.FIELD("buffer", getLinkedListType())); + } + + @SuppressWarnings({"unchecked", "rawtypes"}) + private DataType getLinkedListType() { + TypeSerializer<T> serializer = + InternalSerializers.create(getOutputDataType().getLogicalType()); + return DataTypes.RAW( + LinkedList.class, (TypeSerializer) new LinkedListSerializer<>(serializer)); + } + + @Override + public DataType getOutputDataType() { + return valueDataTypes[0]; + } + + // -------------------------------------------------------------------------------------------- + // Runtime + // -------------------------------------------------------------------------------------------- + + public void accumulate(LagAcc<T> acc, T value) throws Exception { + acc.buffer.add(value); + while (acc.buffer.size() > acc.offset + 1) { + acc.buffer.removeFirst(); + } + } + + public void accumulate(LagAcc<T> acc, T value, int offset) throws Exception { + acc.offset = offset; Review comment: better validating offset > -1 and giving some meaningful exception message. ########## File path: flink-table/flink-table-planner-blink/src/main/java/org/apache/flink/table/planner/functions/aggfunctions/LagAggFunction.java ########## @@ -0,0 +1,159 @@ +/* + * 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.api.common.typeutils.TypeSerializer; +import org.apache.flink.table.api.DataTypes; +import org.apache.flink.table.api.TableException; +import org.apache.flink.table.functions.AggregateFunction; +import org.apache.flink.table.runtime.functions.aggregate.BuiltInAggregateFunction; +import org.apache.flink.table.runtime.typeutils.InternalSerializers; +import org.apache.flink.table.runtime.typeutils.LinkedListSerializer; +import org.apache.flink.table.types.DataType; +import org.apache.flink.table.types.logical.LogicalType; +import org.apache.flink.table.types.logical.LogicalTypeRoot; +import org.apache.flink.table.types.utils.DataTypeUtils; + +import java.util.Arrays; +import java.util.LinkedList; +import java.util.List; +import java.util.Objects; + +/** Lag {@link AggregateFunction}. */ +public class LagAggFunction<T> extends BuiltInAggregateFunction<T, LagAggFunction.LagAcc<T>> { + + private final transient DataType[] valueDataTypes; + + @SuppressWarnings("unchecked") + public LagAggFunction(LogicalType[] valueTypes) { + this.valueDataTypes = + Arrays.stream(valueTypes) + .map(DataTypeUtils::toInternalDataType) + .toArray(DataType[]::new); + if (valueDataTypes.length == 3 + && valueDataTypes[2].getLogicalType().getTypeRoot() != LogicalTypeRoot.NULL) { + if (valueDataTypes[0].getConversionClass() != valueDataTypes[2].getConversionClass()) { + throw new TableException( + String.format( + "Please explicitly cast default value %s to %s.", + valueDataTypes[2], valueDataTypes[1])); + } + } + } + + // -------------------------------------------------------------------------------------------- + // Planning + // -------------------------------------------------------------------------------------------- + + @Override + public List<DataType> getArgumentDataTypes() { + return Arrays.asList(valueDataTypes); + } + + @Override + public DataType getAccumulatorDataType() { + return DataTypes.STRUCTURED( + LagAcc.class, + DataTypes.FIELD("offset", DataTypes.INT()), + DataTypes.FIELD("defaultValue", valueDataTypes[0]), + DataTypes.FIELD("buffer", getLinkedListType())); + } + + @SuppressWarnings({"unchecked", "rawtypes"}) + private DataType getLinkedListType() { + TypeSerializer<T> serializer = + InternalSerializers.create(getOutputDataType().getLogicalType()); + return DataTypes.RAW( + LinkedList.class, (TypeSerializer) new LinkedListSerializer<>(serializer)); + } + + @Override + public DataType getOutputDataType() { + return valueDataTypes[0]; + } + + // -------------------------------------------------------------------------------------------- + // Runtime + // -------------------------------------------------------------------------------------------- + + public void accumulate(LagAcc<T> acc, T value) throws Exception { + acc.buffer.add(value); + while (acc.buffer.size() > acc.offset + 1) { + acc.buffer.removeFirst(); + } + } + + public void accumulate(LagAcc<T> acc, T value, int offset) throws Exception { + acc.offset = offset; + accumulate(acc, value); + } + + public void accumulate(LagAcc<T> acc, T value, int offset, T defaultValue) throws Exception { Review comment: ditto ########## File path: flink-table/flink-table-planner-blink/src/main/scala/org/apache/flink/table/planner/plan/utils/AggFunctionFactory.scala ########## @@ -52,7 +52,8 @@ import scala.collection.JavaConversions._ class AggFunctionFactory( Review comment: minor: param in doc is miss matching. -- This is an automated message from the Apache Git Service. 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