org.apache.arrow.memory.util

Class ByteFunctionHelpers

java.lang.Object

org.apache.arrow.memory.util.ByteFunctionHelpers

public class ByteFunctionHelpers
extends Object

Utility methods for memory comparison at a byte level.

Method Summary

Modifier and Type	Method and Description
static int	combineHash(int currentHash, int newHash) Generate a new hashCode with the given current hashCode and new hashCode.
static int	compare(ArrowBuf left, int lStart, int lEnd, byte[] right, int rStart, int rEnd) Helper function to compare a set of bytes in ArrowBuf to a ByteArray.
static int	compare(ArrowBuf left, long lStart, long lEnd, ArrowBuf right, long rStart, long rEnd) Helper function to compare a set of bytes in two ArrowBufs.
static int	equal(ArrowBuf left, long lStart, long lEnd, ArrowBuf right, long rStart, long rEnd) Helper function to check for equality of bytes in two ArrowBufs.
static int	hash(ArrowBufHasher hasher, ArrowBuf buf, long start, long end) Compute hashCode with the given ArrowBufHasher, ArrowBuf and start/end index.
static int	hash(ArrowBuf buf, long start, long end) Compute hashCode with the given ArrowBuf and start/end index.
static int	unsignedIntCompare(int a, int b)
static int	unsignedLongCompare(long a, long b) Compares the two specified long values, treating them as unsigned values between 0 and 2^64 - 1 inclusive.

Methods inherited from class java.lang.Object

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

Method Detail

equal

public static int equal(ArrowBuf left,
                        long lStart,
                        long lEnd,
                        ArrowBuf right,
                        long rStart,
                        long rEnd)

Helper function to check for equality of bytes in two ArrowBufs.

Parameters:

left - Left ArrowBuf for comparison

lStart - start offset in the buffer

lEnd - end offset in the buffer

right - Right ArrowBuf for comparison

rStart - start offset in the buffer

rEnd - end offset in the buffer

Returns:

1 if equals, 0 otherwise

compare

public static int compare(ArrowBuf left,
                          long lStart,
                          long lEnd,
                          ArrowBuf right,
                          long rStart,
                          long rEnd)

Helper function to compare a set of bytes in two ArrowBufs.

Function will check data before completing in the case that

Parameters:

left - Left ArrowBuf to compare

lStart - start offset in the buffer

lEnd - end offset in the buffer

right - Right ArrowBuf to compare

rStart - start offset in the buffer

rEnd - end offset in the buffer

Returns:

1 if left input is greater, -1 if left input is smaller, 0 otherwise

compare

public static int compare(ArrowBuf left,
                          int lStart,
                          int lEnd,
                          byte[] right,
                          int rStart,
                          int rEnd)

Helper function to compare a set of bytes in ArrowBuf to a ByteArray.

Parameters:

left - Left ArrowBuf for comparison purposes

lStart - start offset in the buffer

lEnd - end offset in the buffer

right - second input to be compared

rStart - start offset in the byte array

rEnd - end offset in the byte array

Returns:

1 if left input is greater, -1 if left input is smaller, 0 otherwise

unsignedLongCompare

public static int unsignedLongCompare(long a,
                                      long b)

Compares the two specified long values, treating them as unsigned values between 0 and 2^64 - 1 inclusive.

Parameters:

a - the first unsigned long to compare

b - the second unsigned long to compare

Returns:

a negative value if a is less than b; a positive value if a is greater than b; or zero if they are equal

unsignedIntCompare

public static int unsignedIntCompare(int a,
                                     int b)

hash

public static int hash(ArrowBuf buf,
                       long start,
                       long end)

Compute hashCode with the given ArrowBuf and start/end index.

hash

public static final int hash(ArrowBufHasher hasher,
                             ArrowBuf buf,
                             long start,
                             long end)

Compute hashCode with the given ArrowBufHasher, ArrowBuf and start/end index.

combineHash

public static int combineHash(int currentHash,
                              int newHash)

Generate a new hashCode with the given current hashCode and new hashCode.