| package edu.uci.ics.asterix.runtime.evaluators.functions; |
| |
| import edu.uci.ics.asterix.common.functions.FunctionConstants; |
| 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.core.algebra.functions.FunctionIdentifier; |
| import edu.uci.ics.hyracks.algebricks.common.exceptions.AlgebricksException; |
| import edu.uci.ics.hyracks.algebricks.common.exceptions.NotImplementedException; |
| import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluator; |
| import edu.uci.ics.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory; |
| import edu.uci.ics.hyracks.data.std.primitive.UTF8StringPointable; |
| 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; |
| import edu.uci.ics.hyracks.dataflow.common.data.marshalling.IntegerSerializerDeserializer; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| |
| public class Substring2Descriptor extends AbstractScalarFunctionDynamicDescriptor { |
| |
| private static final long serialVersionUID = 1L; |
| private final static FunctionIdentifier FID = new FunctionIdentifier(FunctionConstants.ASTERIX_NS, "substring2", 2, |
| true); |
| public static final IFunctionDescriptorFactory FACTORY = new IFunctionDescriptorFactory() { |
| public IFunctionDescriptor createFunctionDescriptor() { |
| return new Substring2Descriptor(); |
| } |
| }; |
| |
| @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 evalString = args[0].createEvaluator(argOut); |
| private ICopyEvaluator evalStart = args[1].createEvaluator(argOut); |
| private final byte stt = ATypeTag.STRING.serialize(); |
| |
| @Override |
| public void evaluate(IFrameTupleReference tuple) throws AlgebricksException { |
| argOut.reset(); |
| evalStart.evaluate(tuple); |
| int start = IntegerSerializerDeserializer.getInt(argOut.getByteArray(), 1) - 1; |
| argOut.reset(); |
| evalString.evaluate(tuple); |
| |
| byte[] bytes = argOut.getByteArray(); |
| int utflen = UTF8StringPointable.getUTFLength(bytes, 1); |
| int sStart = 3; |
| int c = 0; |
| int idxPos1 = 0; |
| // skip to start |
| while (idxPos1 < start && c < utflen) { |
| c += UTF8StringPointable.charSize(bytes, sStart + c); |
| ++idxPos1; |
| } |
| int startSubstr = c; |
| |
| while (c < utflen) { |
| c += UTF8StringPointable.charSize(bytes, sStart + c); |
| } |
| |
| int substrByteLen = c - startSubstr; |
| try { |
| out.writeByte(stt); |
| out.writeByte((byte) ((substrByteLen >>> 8) & 0xFF)); |
| out.writeByte((byte) ((substrByteLen >>> 0) & 0xFF)); |
| out.write(bytes, sStart + startSubstr, substrByteLen); |
| |
| } catch (IOException e) { |
| throw new AlgebricksException(e); |
| } |
| } |
| }; |
| } |
| }; |
| } |
| |
| @Override |
| public FunctionIdentifier getIdentifier() { |
| return FID; |
| } |
| |
| } |