| package edu.uci.ics.asterix.runtime.evaluators.functions; |
| |
| import java.io.DataOutput; |
| |
| import edu.uci.ics.asterix.dataflow.data.nontagged.serde.AObjectSerializerDeserializer; |
| import edu.uci.ics.asterix.om.base.ABoolean; |
| 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.runtime.evaluators.base.AbstractScalarFunctionDynamicDescriptor; |
| import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import edu.uci.ics.hyracks.algebricks.core.algebra.functions.AlgebricksBuiltinFunctions; |
| 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.exceptions.HyracksDataException; |
| import edu.uci.ics.hyracks.dataflow.common.data.accessors.ArrayBackedValueStorage; |
| import edu.uci.ics.hyracks.dataflow.common.data.accessors.IDataOutputProvider; |
| import edu.uci.ics.hyracks.dataflow.common.data.accessors.IFrameTupleReference; |
| |
| public class IsNullDescriptor extends AbstractScalarFunctionDynamicDescriptor { |
| |
| private static final long serialVersionUID = 1L; |
| |
| public final static FunctionIdentifier FID = new FunctionIdentifier(AlgebricksBuiltinFunctions.ALGEBRICKS_NS, |
| "is-null", 1); |
| private final static byte SER_NULL_TYPE_TAG = ATypeTag.NULL.serialize(); |
| public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() { |
| public IFunctionDescriptor createFunctionDescriptor() { |
| return new IsNullDescriptor(); |
| } |
| }; |
| |
| @Override |
| public ICopyEvaluatorFactory createEvaluatorFactory(final ICopyEvaluatorFactory[] args) throws AlgebricksException { |
| return new ICopyEvaluatorFactory() { |
| |
| private static final long serialVersionUID = 1L; |
| |
| @Override |
| public ICopyEvaluator createEvaluator(final IDataOutputProvider output) throws AlgebricksException { |
| return new ICopyEvaluator() { |
| |
| private DataOutput out = output.getDataOutput(); |
| private ArrayBackedValueStorage argOut = new ArrayBackedValueStorage(); |
| private ICopyEvaluator eval = args[0].createEvaluator(argOut); |
| |
| @Override |
| public void evaluate(IFrameTupleReference tuple) throws AlgebricksException { |
| argOut.reset(); |
| eval.evaluate(tuple); |
| boolean isNull = argOut.getByteArray()[argOut.getStartOffset()] == SER_NULL_TYPE_TAG; |
| ABoolean res = isNull ? ABoolean.TRUE : ABoolean.FALSE; |
| try { |
| AObjectSerializerDeserializer.INSTANCE.serialize(res, out); |
| } catch (HyracksDataException e) { |
| throw new AlgebricksException(e); |
| } |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public FunctionIdentifier getIdentifier() { |
| return FID; |
| } |
| |
| } |