Module hash4j

Package com.dynatrace.hash4j.hashing

Interface ByteAccess<T>

Type Parameters:

T - the type of the data object

public interface ByteAccess<T>

Strategy to access contiguous bytes of a data object.

It is recommended to override the default implementations of at least getInt(Object, long) and getLong(Object, long) for best performance.

Method Summary

Modifier and Type	Method	Description
default void	copyToByteArray(T data, long idx, byte[] array, int off, int len)	Copies a given number of bytes from the data object into a given byte[] array.
byte	getByte(T data, long idx)	Returns the byte at a certain position from the given data object as byte.
default int	getByteAsUnsignedInt(T data, long idx)	Returns the byte at a certain position from the given data object as non-negative int.
default long	getByteAsUnsignedLong(T data, long idx)	Returns the byte at a certain position from the given data object as non-negative long.
default int	getInt(T data, long idx)	Returns 4 subsequent bytes starting at a certain position from the given data object as int.
default long	getIntAsUnsignedLong(T data, long idx)	Returns 4 subsequent bytes starting at a certain position from the given data object as non-negative long.
default long	getLong(T data, long idx)	Returns 8 subsequent bytes starting at a certain position from the given data object as long.

Method Details

getByte

byte getByte(T data,
 long idx)

Returns the byte at a certain position from the given data object as byte.

Parameters:

data - the data object

idx - the index

Returns:

the byte

getByteAsUnsignedInt

default int getByteAsUnsignedInt(T data,
 long idx)

Returns the byte at a certain position from the given data object as non-negative int.

This is equivalent to getByte(data, idx) & 0xFF.

Parameters:

data - the data object

idx - the index

Returns:

the byte as non-negative long

getByteAsUnsignedLong

default long getByteAsUnsignedLong(T data,
 long idx)

Returns the byte at a certain position from the given data object as non-negative long.

This is equivalent to getByte(data, idx) & 0xFFL.

Parameters:

data - the data object

idx - the index

Returns:

the byte as non-negative long

getInt

default int getInt(T data,
 long idx)

Returns 4 subsequent bytes starting at a certain position from the given data object as int.

This is equivalent to (getByte(data, idx) & 0xFF) | ((getByte(data, idx + 1) & 0xFF) << 8) | ((getByte(data, idx + 2) & 0xFF) << 16) | ((int)getByte(data, idx+3) << 24).

Parameters:

data - the data object

idx - the index of the first byte

Returns:

4 bytes as integer

getIntAsUnsignedLong

default long getIntAsUnsignedLong(T data,
 long idx)

Returns 4 subsequent bytes starting at a certain position from the given data object as non-negative long.

This is equivalent to getInt(data, idx) & 0xFFFFFFFFL.

Parameters:

data - the data object

idx - the index of the first byte

Returns:

4 bytes as non-negative long

getLong

default long getLong(T data,
 long idx)

Returns 8 subsequent bytes starting at a certain position from the given data object as long.

This is equivalent to getIntUnsigned(data, idx) | ((long) getInt(data, idx + 4) << 32).

Parameters:

data - the data object

idx - the index of the first byte

Returns:

8 bytes as long

copyToByteArray

default void copyToByteArray(T data,
 long idx,
 byte[] array,
 int off,
 int len)

Copies a given number of bytes from the data object into a given byte[] array.

This is equivalent to for(int i = 0; i < len; ++i) array[off + i] = getByte(data, idx + i).

Parameters:

data - the data object

idx - the index of the first byte

array - the target byte array

off - the target offset

len - the number of bytes