org.apache.flink.table.codegen.expr.SumWithRetractAggFunction.scala Maven / Gradle / Ivy
/*
* 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.codegen.expr
import org.apache.flink.table.api.scala._
import org.apache.flink.table.dataformat.Decimal
import org.apache.flink.table.expressions.{IsNull, Literal, _}
import org.apache.flink.table.functions.DeclarativeAggregateFunction
import org.apache.flink.table.types.{DataTypes, DecimalType, InternalType}
/**
* built-in sum with retract aggregate function
*/
abstract class SumWithRetractAggFunction extends DeclarativeAggregateFunction {
override def inputCount: Int = 1
private lazy val sum = UnresolvedAggBufferReference("sum", getResultType)
private lazy val count = UnresolvedAggBufferReference("count", DataTypes.LONG)
override def aggBufferAttributes: Seq[UnresolvedAggBufferReference] = Seq(sum, count)
override def initialValuesExpressions: Seq[Expression] = Seq(
/* sum = */ Null(sum.resultType),
/* count = */ Literal(0L)
)
override def accumulateExpressions: Seq[Expression] = Seq(
/* sum = */ IsNull(operands(0)) ? (sum, IsNull(sum) ? (operands(0), sum + operands(0))),
/* count = */ IsNull(operands(0)) ? (count, count + 1)
)
override def retractExpressions: Seq[Expression] = Seq(
/* sum = */ IsNull(operands(0)) ? (
sum, IsNull(sum) ? (zeroLiteral - operands(0), sum - operands(0))),
/* count = */ IsNull(operands(0)) ? (count, count - 1)
)
override def mergeExpressions: Seq[Expression] = Seq(
/* sum = */ If(IsNull(sum.right), sum.left,
If(IsNull(sum.left), sum.right, sum.left + sum.right)),
/* count = */ count.left + count.right
)
override def getValueExpression: Expression =
EqualTo(count, Literal(0L)) ? (Null(sum.resultType), sum)
def zeroLiteral: Expression
}
/**
* Built-in Int Sum with retract aggregate function
*/
class IntSumWithRetractAggFunction extends SumWithRetractAggFunction {
override def getResultType: InternalType = DataTypes.INT
override def zeroLiteral: Expression = 0
}
/**
* Built-in Byte Sum with retract aggregate function
*/
class ByteSumWithRetractAggFunction extends SumWithRetractAggFunction {
override def getResultType: InternalType = DataTypes.BYTE
override def zeroLiteral: Expression = 0.toByte
}
/**
* Built-in Short Sum with retract aggregate function
*/
class ShortSumWithRetractAggFunction extends SumWithRetractAggFunction {
override def getResultType: InternalType = DataTypes.SHORT
override def zeroLiteral: Expression = 0.toShort
}
/**
* Built-in Long Sum with retract aggregate function
*/
class LongSumWithRetractAggFunction extends SumWithRetractAggFunction {
override def getResultType: InternalType = DataTypes.LONG
override def zeroLiteral: Expression = 0L
}
/**
* Built-in Float Sum with retract aggregate function
*/
class FloatSumWithRetractAggFunction extends SumWithRetractAggFunction {
override def getResultType: InternalType = DataTypes.FLOAT
override def zeroLiteral: Expression = 0.0F
}
/**
* Built-in Double Sum with retract aggregate function
*/
class DoubleSumWithRetractAggFunction extends SumWithRetractAggFunction {
override def getResultType: InternalType = DataTypes.DOUBLE
override def zeroLiteral: Expression = 0.0
}
/**
* Built-in Decimal Sum with retract aggregate function
*/
class DecimalSumWithRetractAggFunction(argType: DecimalType)
extends SumWithRetractAggFunction {
override def getResultType: InternalType =
Decimal.inferAggSumType(argType.precision, argType.scale)
override def zeroLiteral: Expression = 0
}