Package org.apache.druid.frame.field

Class TransformUtils

java.lang.Object

org.apache.druid.frame.field.TransformUtils

public class TransformUtils
extends Object

Utility methods to map the primitive numeric types into an equi-wide byte representation, such that the given byte sequence preserves the ordering of the original type when done byte comparison. Checkout FrameReaderUtils.compareMemoryToByteArrayUnsigned(org.apache.datasketches.memory.Memory, long, long, byte[], int, int) for how this byte comparison is performed.

Constructor Summary

Constructors

Constructor	Description
TransformUtils()

Method Summary

Modifier and Type	Method	Description
static double	detransformToDouble(long transformedBits, FrameType frameType)	Inverse of transformFromDouble(double, FrameType).
static float	detransformToFloat(int transformedBits, FrameType frameType)	Inverse of transformFromFloat(float, FrameType).
static long	detransformToLong(long bits)	Reverse the transformFromLong(long) function.
static long	transformFromDouble(double n, FrameType frameType)	Transforms a double into a form where it can be compared as unsigned bytes without decoding.
static int	transformFromFloat(float n, FrameType frameType)	Transforms a float into a form where it can be compared as unsigned bytes without decoding.
static long	transformFromLong(long n)	Transforms a long into a form where it can be compared as unsigned bytes without decoding.

Methods inherited from class java.lang.Object

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

Constructor Details

TransformUtils

public TransformUtils()

Method Details

transformFromDouble

public static long transformFromDouble(double n,
 FrameType frameType)

Transforms a double into a form where it can be compared as unsigned bytes without decoding.

Parameters:

n - the number

frameType - the output frame type; required because the floating point serialization format changed from FrameType.ROW_BASED_V1 to FrameType.ROW_BASED_V2.

detransformToDouble

public static double detransformToDouble(long transformedBits,
 FrameType frameType)

Inverse of transformFromDouble(double, FrameType).

transformFromLong

public static long transformFromLong(long n)

Transforms a long into a form where it can be compared as unsigned bytes without decoding.

detransformToLong

public static long detransformToLong(long bits)

Reverse the transformFromLong(long) function.

transformFromFloat

public static int transformFromFloat(float n,
 FrameType frameType)

Transforms a float into a form where it can be compared as unsigned bytes without decoding.

Parameters:

n - the number

frameType - the output frame type; required because the floating point serialization format changed from FrameType.ROW_BASED_V1 to FrameType.ROW_BASED_V2.

detransformToFloat

public static float detransformToFloat(int transformedBits,
 FrameType frameType)

Inverse of transformFromFloat(float, FrameType).