org.apache.flink.table.functions.python.PythonTableFunction 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.functions.python;

import org.apache.flink.annotation.Internal;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.table.catalog.DataTypeFactory;
import org.apache.flink.table.functions.TableFunction;
import org.apache.flink.table.types.DataType;
import org.apache.flink.table.types.inference.TypeInference;
import org.apache.flink.table.types.inference.TypeStrategies;
import org.apache.flink.table.types.utils.TypeConversions;
import org.apache.flink.types.Row;

import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

/** The wrapper of user defined python table function. */
@Internal
public class PythonTableFunction extends TableFunction implements PythonFunction {

    private static final long serialVersionUID = 1L;

    private final String name;
    private final byte[] serializedScalarFunction;
    private final TypeInformation[] inputTypes;
    private final RowTypeInfo resultType;
    private final PythonFunctionKind pythonFunctionKind;
    private final boolean deterministic;
    private final PythonEnv pythonEnv;
    private final boolean takesRowAsInput;

    public PythonTableFunction(
            String name,
            byte[] serializedScalarFunction,
            TypeInformation[] inputTypes,
            RowTypeInfo resultType,
            PythonFunctionKind pythonFunctionKind,
            boolean deterministic,
            boolean takesRowAsInput,
            PythonEnv pythonEnv) {
        this.name = name;
        this.serializedScalarFunction = serializedScalarFunction;
        this.inputTypes = inputTypes;
        this.resultType = resultType;
        this.pythonFunctionKind = pythonFunctionKind;
        this.deterministic = deterministic;
        this.pythonEnv = pythonEnv;
        this.takesRowAsInput = takesRowAsInput;
    }

    public void eval(Object... args) {
        throw new UnsupportedOperationException(
                "This method is a placeholder and should not be called.");
    }

    @Override
    public byte[] getSerializedPythonFunction() {
        return serializedScalarFunction;
    }

    @Override
    public PythonEnv getPythonEnv() {
        return pythonEnv;
    }

    @Override
    public PythonFunctionKind getPythonFunctionKind() {
        return pythonFunctionKind;
    }

    @Override
    public boolean takesRowAsInput() {
        return takesRowAsInput;
    }

    @Override
    public boolean isDeterministic() {
        return deterministic;
    }

    @Override
    public TypeInformation[] getParameterTypes(Class[] signature) {
        if (inputTypes != null) {
            return inputTypes;
        } else {
            return super.getParameterTypes(signature);
        }
    }

    @Override
    public TypeInformation getResultType() {
        return resultType;
    }

    @Override
    public TypeInference getTypeInference(DataTypeFactory typeFactory) {
        TypeInference.Builder builder = TypeInference.newBuilder();
        if (inputTypes != null) {
            final List argumentDataTypes =
                    Stream.of(inputTypes)
                            .map(TypeConversions::fromLegacyInfoToDataType)
                            .collect(Collectors.toList());
            builder.typedArguments(argumentDataTypes);
        }
        return builder.outputTypeStrategy(
                        TypeStrategies.explicit(
                                TypeConversions.fromLegacyInfoToDataType(resultType)))
                .build();
    }

    @Override
    public String toString() {
        return name;
    }
}