asterixdb/asterix-runtime/src/main/java/org/apache/asterix/runtime/evaluators/constructors/ADateTimeConstructorWithFormatDescriptor.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.evaluators.constructors;

import org.apache.asterix.om.base.AMutableDateTime;
import org.apache.asterix.om.base.AMutableInt64;
import org.apache.asterix.om.base.temporal.AsterixTemporalTypeParseException;
import org.apache.asterix.om.base.temporal.DateTimeFormatUtils;
import org.apache.asterix.om.functions.BuiltinFunctions;
import org.apache.asterix.om.functions.IFunctionDescriptor;
import org.apache.asterix.om.functions.IFunctionDescriptorFactory;
import org.apache.asterix.om.types.ATypeTag;
import org.apache.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
import org.apache.asterix.runtime.evaluators.functions.PointableHelper;
import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
import org.apache.hyracks.algebricks.runtime.base.IEvaluatorContext;
import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluator;
import org.apache.hyracks.algebricks.runtime.base.IScalarEvaluatorFactory;
import org.apache.hyracks.api.exceptions.HyracksDataException;
import org.apache.hyracks.data.std.api.IPointable;
import org.apache.hyracks.data.std.primitive.UTF8StringPointable;
import org.apache.hyracks.data.std.primitive.VoidPointable;
import org.apache.hyracks.dataflow.common.data.accessors.IFrameTupleReference;

public class ADateTimeConstructorWithFormatDescriptor extends AbstractScalarFunctionDynamicDescriptor {
    private static final long serialVersionUID = 1L;
    public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
        @Override
        public IFunctionDescriptor createFunctionDescriptor() {
            return new ADateTimeConstructorWithFormatDescriptor();
        }
    };

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

            @Override
            public IScalarEvaluator createScalarEvaluator(IEvaluatorContext ctx) throws HyracksDataException {
                return new AbstractDateTimeConstructorEvaluator(ctx, args[0].createScalarEvaluator(ctx), sourceLoc) {

                    private final IScalarEvaluator formatEval = args[1].createScalarEvaluator(ctx);
                    private final IPointable formatArg = new VoidPointable();
                    private final UTF8StringPointable formatTextPtr = new UTF8StringPointable();
                    private final AMutableInt64 aInt64 = new AMutableInt64(0);

                    @Override
                    protected void evaluateInput(IFrameTupleReference tuple) throws HyracksDataException {
                        super.evaluateInput(tuple);
                        formatEval.evaluate(tuple, formatArg);
                    }

                    @Override
                    protected boolean checkAndSetMissingOrNull(IPointable result) throws HyracksDataException {
                        return PointableHelper.checkAndSetMissingOrNull(result, inputArg, formatArg);
                    }

                    @Override
                    protected boolean parseDateTime(UTF8StringPointable textPtr, AMutableDateTime result) {
                        byte[] formatBytes = formatArg.getByteArray();
                        int formatStartOffset = formatArg.getStartOffset();
                        int formatLength = formatArg.getLength();
                        if (formatBytes[formatStartOffset] != ATypeTag.SERIALIZED_STRING_TYPE_TAG) {
                            return false;
                        }
                        formatTextPtr.set(formatBytes, formatStartOffset + 1, formatLength - 1);
                        try {
                            if (DateTimeFormatUtils.getInstance().parseDateTime(aInt64, textPtr.getByteArray(),
                                    textPtr.getCharStartOffset(), textPtr.getUTF8Length(), formatBytes,
                                    formatTextPtr.getCharStartOffset(), formatTextPtr.getUTF8Length(),
                                    DateTimeFormatUtils.DateTimeParseMode.DATETIME, false)) {
                                result.setValue(aInt64.getLongValue());
                                return true;
                            } else {
                                return false;
                            }
                        } catch (AsterixTemporalTypeParseException e) {
                            // shouldn't happen
                            return false;
                        }
                    }

                    @Override
                    protected FunctionIdentifier getIdentifier() {
                        return ADateTimeConstructorWithFormatDescriptor.this.getIdentifier();
                    }
                };
            }
        };
    }

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