asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/runningaggregates/std/TidRunningAggregateDescriptor.java

/*
 * 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.asterix.runtime.runningaggregates.std;

import org.apache.asterix.formats.nontagged.SerializerDeserializerProvider;
import org.apache.asterix.om.base.AInt64;
import org.apache.asterix.om.base.AMutableInt64;
import org.apache.asterix.om.functions.BuiltinFunctions;
import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
import org.apache.asterix.om.types.BuiltinType;
import org.apache.asterix.runtime.runningaggregates.base.AbstractRunningAggregateFunctionDynamicDescriptor;
import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
import org.apache.hyracks.algebricks.runtime.base.IEvaluatorContext;
import org.apache.hyracks.algebricks.runtime.base.IRunningAggregateEvaluator;
import org.apache.hyracks.algebricks.runtime.base.IRunningAggregateEvaluatorFactory;
import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
import org.apache.hyracks.api.dataflow.value.ISerializerDeserializer;
import org.apache.hyracks.api.exceptions.HyracksDataException;
import org.apache.hyracks.data.std.api.IPointable;
import org.apache.hyracks.data.std.util.ArrayBackedValueStorage;
import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;

public class TidRunningAggregateDescriptor extends AbstractRunningAggregateFunctionDynamicDescriptor {

    private static final long serialVersionUID = 1L;
    public static final IFunctionDescriptorFactory FACTORY = TidRunningAggregateDescriptor::new;

    @Override
    public IRunningAggregateEvaluatorFactory createRunningAggregateEvaluatorFactory(IScalarEvaluatorFactory[] args) {
        return new IRunningAggregateEvaluatorFactory() {
            private static final long serialVersionUID = 1L;

            @SuppressWarnings("unchecked")
            @Override
            public IRunningAggregateEvaluator createRunningAggregateEvaluator(IEvaluatorContext ctx) {

                return new IRunningAggregateEvaluator() {

                    private final ArrayBackedValueStorage resultStorage = new ArrayBackedValueStorage();
                    private final ISerializerDeserializer<AInt64> serde =
                            SerializerDeserializerProvider.INSTANCE.getSerializerDeserializer(BuiltinType.AINT64);
                    private final AMutableInt64 m = new AMutableInt64(0);
                    private long cnt;

                    @Override
                    public void step(IFrameTupleReference tuple, IPointable result) throws HyracksDataException {
                        resultStorage.reset();
                        m.setValue(cnt);
                        serde.serialize(m, resultStorage.getDataOutput());
                        result.set(resultStorage);
                        ++cnt;
                    }

                    @Override
                    public void init() {
                        cnt = 1;
                    }
                };
            }
        };
    }

    @Override
    public FunctionIdentifier getIdentifier() {
        return BuiltinFunctions.TID;
    }

}