Package org.apache.iotdb.db.mpp.transformation.dag.transformer.unary

Class TransparentTransformer

java.lang.Object

org.apache.iotdb.db.mpp.transformation.dag.transformer.Transformer

org.apache.iotdb.db.mpp.transformation.dag.transformer.unary.UnaryTransformer

org.apache.iotdb.db.mpp.transformation.dag.transformer.unary.TransparentTransformer

All Implemented Interfaces:

LayerPointReader, YieldableReader

public class TransparentTransformer
extends UnaryTransformer

this is a special transformer which outputs data just as input without any modification.

i.e. it's just the function f(x) = x.

It's mainly used for a UDF with aggregation query as its parameters.

Field Summary

Fields inherited from class org.apache.iotdb.db.mpp.transformation.dag.transformer.unary.UnaryTransformer

isLayerPointReaderConstant, layerPointReader, layerPointReaderDataType

Fields inherited from class org.apache.iotdb.db.mpp.transformation.dag.transformer.Transformer

cachedBinary, cachedBoolean, cachedDouble, cachedFloat, cachedInt, cachedLong, cachedTime, currentNull, hasCachedValue

Constructor Summary

Constructors

Constructor	Description
TransparentTransformer(LayerPointReader layerPointReader)

Method Summary

Modifier and Type	Method	Description
org.apache.iotdb.tsfile.file.metadata.enums.TSDataType	getDataType()
protected void	transformAndCache()

Methods inherited from class org.apache.iotdb.db.mpp.transformation.dag.transformer.unary.UnaryTransformer

cacheValue, isConstantPointReader, yieldValue

Methods inherited from class org.apache.iotdb.db.mpp.transformation.dag.transformer.Transformer

currentBinary, currentBoolean, currentDouble, currentFloat, currentInt, currentLong, currentTime, isCurrentNull, next, readyForNext, yield

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TransparentTransformer

public TransparentTransformer(LayerPointReader layerPointReader)

Method Detail

getDataType

public org.apache.iotdb.tsfile.file.metadata.enums.TSDataType getDataType()

transformAndCache

protected void transformAndCache()
                          throws QueryProcessException,
                                 java.io.IOException

Specified by:

transformAndCache in class UnaryTransformer

Throws:

QueryProcessException

java.io.IOException