asterix-runtime/src/main/java/edu/uci/ics/asterix/runtime/evaluators/functions/NotDescriptor.java

package edu.uci.ics.asterix.runtime.evaluators.functions;

import java.io.DataOutput;

import edu.uci.ics.asterix.dataflow.data.nontagged.serde.ABooleanSerializerDeserializer;
import edu.uci.ics.asterix.formats.nontagged.AqlSerializerDeserializerProvider;
import edu.uci.ics.asterix.om.base.ABoolean;
import edu.uci.ics.asterix.om.base.ANull;
import edu.uci.ics.asterix.om.functions.AsterixBuiltinFunctions;
import edu.uci.ics.asterix.om.functions.IFunctionDescriptor;
import edu.uci.ics.asterix.om.functions.IFunctionDescriptorFactory;
import edu.uci.ics.asterix.om.types.ATypeTag;
import edu.uci.ics.asterix.om.types.BuiltinType;
import edu.uci.ics.asterix.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor;
import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException;
import edu.uci.ics.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator;
import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;
import edu.uci.ics.hyracks.api.dataflow.value.ISerializerDeserializer;
import edu.uci.ics.hyracks.api.exceptions.HyracksDataException;
import edu.uci.ics.hyracks.data.std.api.IDataOutputProvider;
import edu.uci.ics.hyracks.data.std.util.ArrayBackedValueStorage;
import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference;

public class NotDescriptor extends AbstractScalarFunctionDynamicDescriptor {

    private static final long serialVersionUID = 1L;

    private final static byte SER_BOOLEAN_TYPE_TAG = ATypeTag.BOOLEAN.serialize();
    private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize();
    public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() {
        public IFunctionDescriptor createFunctionDescriptor() {
            return new NotDescriptor();
        }
    };

    @Override
    public FunctionIdentifier getIdentifier() {
        return AsterixBuiltinFunctions.NOT;
    }

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

            @Override
            public ICopyEvaluator createEvaluator(IDataOutputProvider output) throws AlgebricksException {
                final DataOutput out = output.getDataOutput();

                return new ICopyEvaluator() {

                    private ArrayBackedValueStorage argOut = new ArrayBackedValueStorage();
                    private ICopyEvaluator eval = args[0].createEvaluator(argOut);

                    private String errorMessage = AsterixBuiltinFunctions.NOT.getName()
                            + ": expects input type BOOLEAN/NULL";
                    @SuppressWarnings("unchecked")
                    private ISerializerDeserializer<ABoolean> booleanSerde = AqlSerializerDeserializerProvider.INSTANCE
                            .getSerializerDeserializer(BuiltinType.ABOOLEAN);
                    @SuppressWarnings("unchecked")
                    private ISerializerDeserializer<ANull> nullSerde = AqlSerializerDeserializerProvider.INSTANCE
                            .getSerializerDeserializer(BuiltinType.ANULL);

                    @Override
                    public void evaluate(IFrameTupleReference tuple) throws AlgebricksException {
                        argOut.reset();
                        eval.evaluate(tuple);
                        try {
                            if (argOut.getByteArray()[0] == SER_BOOLEAN_TYPE_TAG) {
                                boolean argRes = ABooleanSerializerDeserializer.getBoolean(argOut.getByteArray(), 1);
                                ABoolean aResult = argRes ? (ABoolean.FALSE) : (ABoolean.TRUE);
                                booleanSerde.serialize(aResult, out);
                            } else if (argOut.getByteArray()[0] == SER_NULL_TYPE_TAG)
                                nullSerde.serialize(ANull.NULL, out);
                            else
                                throw new AlgebricksException(errorMessage);
                        } catch (HyracksDataException hde) {
                            throw new AlgebricksException(hde);
                        }
                    }
                };
            }
        };
    }

}