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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.table.api.DataTypes;
import org.apache.flink.table.expressions.CallExpression;
import org.apache.flink.table.expressions.Expression;
import org.apache.flink.table.expressions.UnresolvedReferenceExpression;
import org.apache.flink.table.types.DataType;
import org.apache.flink.table.types.logical.DecimalType;
import org.apache.flink.table.types.logical.LocalZonedTimestampType;
import org.apache.flink.table.types.logical.TimeType;
import org.apache.flink.table.types.logical.TimestampType;
import java.util.Arrays;
import static org.apache.flink.table.expressions.ApiExpressionUtils.unresolvedRef;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.equalTo;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.greaterThan;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.ifThenElse;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.literal;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.minus;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.nullOf;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.or;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.plus;
import static org.apache.flink.table.planner.expressions.ExpressionBuilder.typeLiteral;
import static org.apache.flink.table.planner.functions.InternalFunctionDefinitions.THROW_EXCEPTION;
/** Base class for built-in single value aggregate function. */
public abstract class SingleValueAggFunction extends DeclarativeAggregateFunction {
private static final long serialVersionUID = 8850662568341069949L;
private static final Expression ZERO = literal(0, DataTypes.INT().notNull());
private static final Expression ONE = literal(1, DataTypes.INT().notNull());
private static final String ERROR_MSG =
"SingleValueAggFunction received more than one element.";
private UnresolvedReferenceExpression value = unresolvedRef("value");
private UnresolvedReferenceExpression count = unresolvedRef("count");
@Override
public int operandCount() {
return 1;
}
@Override
public UnresolvedReferenceExpression[] aggBufferAttributes() {
return new UnresolvedReferenceExpression[] {value, count};
}
@Override
public DataType[] getAggBufferTypes() {
return new DataType[] {getResultType(), DataTypes.INT()};
}
@Override
public Expression[] initialValuesExpressions() {
return new Expression[] {
/* value = */ nullOf(getResultType()), /* count = */ ZERO,
};
}
@Override
public Expression[] accumulateExpressions() {
return new Expression[] {
/* value = count > 0 ? exception : operand(0) */
ifThenElse(
greaterThan(count, ZERO),
throwException(ERROR_MSG, getResultType()),
operand(0)),
/* count = count + 1 */
plus(count, ONE)
};
}
@Override
public Expression[] retractExpressions() {
return new Expression[] {
/* value = count == 1 || count == 0 ? null : exception */
ifThenElse(
or(equalTo(count, ONE), equalTo(count, ZERO)),
nullOf(getResultType()),
throwException(ERROR_MSG, getResultType())),
/* count = count - 1 */
minus(count, ONE)
};
}
@Override
public Expression[] mergeExpressions() {
return new Expression[] {
ifThenElse(
greaterThan(plus(count, mergeOperand(count)), ONE),
throwException(ERROR_MSG, getResultType()),
ifThenElse(
equalTo(plus(count, mergeOperand(count)), ZERO),
ifThenElse(
// both zero or right > 0 means we need to reserve the new value
// here
or(
equalTo(count, ZERO),
greaterThan(mergeOperand(count), ZERO)),
mergeOperand(value),
nullOf(getResultType())),
mergeOperand(value))),
plus(count, mergeOperand(count))
};
}
@Override
public Expression getValueExpression() {
return value;
}
private static Expression throwException(String msg, DataType type) {
// it is the internal function without catalog.
// so it can not be find in any catalog or built-in functions.
return new CallExpression(
THROW_EXCEPTION, Arrays.asList(literal(msg), typeLiteral(type)), type);
}
/** Built-in byte single value aggregate function. */
public static final class ByteSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.TINYINT();
}
}
/** Built-in short single value aggregate function. */
public static final class ShortSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.SMALLINT();
}
}
/** Built-in int single value aggregate function. */
public static final class IntSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.INT();
}
}
/** Built-in long single value aggregate function. */
public static final class LongSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.BIGINT();
}
}
/** Built-in float single value aggregate function. */
public static final class FloatSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.FLOAT();
}
}
/** Built-in double single value aggregate function. */
public static final class DoubleSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.DOUBLE();
}
}
/** Built-in boolean single value aggregate function. */
public static final class BooleanSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.BOOLEAN();
}
}
/** Built-in decimal single value aggregate function. */
public static final class DecimalSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
private final DecimalType type;
public DecimalSingleValueAggFunction(DecimalType type) {
this.type = type;
}
@Override
public DataType getResultType() {
return DataTypes.DECIMAL(type.getPrecision(), type.getScale());
}
}
/** Built-in string single value aggregate function. */
public static final class StringSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.STRING();
}
}
/** Built-in date single value aggregate function. */
public static final class DateSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.DATE();
}
}
/** Built-in time single value aggregate function. */
public static final class TimeSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
@Override
public DataType getResultType() {
return DataTypes.TIME(TimeType.DEFAULT_PRECISION);
}
}
/** Built-in timestamp single value aggregate function. */
public static final class TimestampSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 320495723666949978L;
private final TimestampType type;
public TimestampSingleValueAggFunction(TimestampType type) {
this.type = type;
}
@Override
public DataType getResultType() {
return DataTypes.TIMESTAMP(type.getPrecision());
}
}
/** Built-in timestampLtz single value aggregate function. */
public static final class TimestampLtzSingleValueAggFunction extends SingleValueAggFunction {
private static final long serialVersionUID = 1L;
private final LocalZonedTimestampType type;
public TimestampLtzSingleValueAggFunction(LocalZonedTimestampType type) {
this.type = type;
}
@Override
public DataType getResultType() {
return DataTypes.TIMESTAMP_LTZ(type.getPrecision());
}
}
}