Package org.agrona

Class BufferUtil

java.lang.Object

org.agrona.BufferUtil

public final class BufferUtil
extends Object

Common functions for buffer implementations.

Field Summary

Fields

Modifier and Type	Field	Description
static final long	ARRAY_BASE_OFFSET	Byte array base offset.
static final long	BYTE_BUFFER_ADDRESS_FIELD_OFFSET	Offset of the java.nio.Buffer#address field.
static final long	BYTE_BUFFER_HB_FIELD_OFFSET	Offset of the java.nio.ByteBuffer#hb field.
static final long	BYTE_BUFFER_OFFSET_FIELD_OFFSET	Offset of the java.nio.ByteBuffer#offset field.
static final ByteOrder	NATIVE_BYTE_ORDER	Native byte order.
static final byte[]	NULL_BYTES	UTF-8-encoded byte representation of the "null" string.

Method Summary

Modifier and Type	Method	Description
static long	address(ByteBuffer buffer)	Get the address at which the underlying buffer storage begins.
static ByteBuffer	allocateDirectAligned(int capacity, int alignment)	Allocate a new direct ByteBuffer that is aligned on a given alignment boundary.
static byte[]	array(ByteBuffer buffer)	Get the array from a read-only ByteBuffer similar to ByteBuffer.array().
static int	arrayOffset(ByteBuffer buffer)	Get the array offset from a read-only ByteBuffer similar to ByteBuffer.arrayOffset().
static void	boundsCheck(byte[] buffer, long index, int length)	Bounds check the access range and throw a IndexOutOfBoundsException if exceeded.
static void	boundsCheck(ByteBuffer buffer, long index, int length)	Bounds check the access range and throw a IndexOutOfBoundsException if exceeded.
static void	free(ByteBuffer buffer)	Free direct ByteBuffer by invoking Cleaner on it.
static void	free(DirectBuffer buffer)	Free the underlying direct ByteBuffer by invoking Cleaner on it.

Methods inherited from class java.lang.Object

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

Field Details

NULL_BYTES

public static final byte[] NULL_BYTES

UTF-8-encoded byte representation of the "null" string.

NATIVE_BYTE_ORDER

public static final ByteOrder NATIVE_BYTE_ORDER

Native byte order.

ARRAY_BASE_OFFSET

public static final long ARRAY_BASE_OFFSET

Byte array base offset.

BYTE_BUFFER_HB_FIELD_OFFSET

public static final long BYTE_BUFFER_HB_FIELD_OFFSET

Offset of the java.nio.ByteBuffer#hb field.

BYTE_BUFFER_OFFSET_FIELD_OFFSET

public static final long BYTE_BUFFER_OFFSET_FIELD_OFFSET

Offset of the java.nio.ByteBuffer#offset field.

BYTE_BUFFER_ADDRESS_FIELD_OFFSET

public static final long BYTE_BUFFER_ADDRESS_FIELD_OFFSET

Offset of the java.nio.Buffer#address field.

Method Details

boundsCheck

public static void boundsCheck(byte[] buffer,
 long index,
 int length)

Bounds check the access range and throw a IndexOutOfBoundsException if exceeded.

Parameters:

buffer - to be checked.

index - at which the access will begin.

length - of the range accessed.

boundsCheck

public static void boundsCheck(ByteBuffer buffer,
 long index,
 int length)

Bounds check the access range and throw a IndexOutOfBoundsException if exceeded.

Parameters:

buffer - to be checked.

index - at which the access will begin.

length - of the range accessed.

address

public static long address(ByteBuffer buffer)

Get the address at which the underlying buffer storage begins.

Parameters:

buffer - that wraps the underlying storage.

Returns:

the memory address at which the buffer storage begins.

array

public static byte[] array(ByteBuffer buffer)

Get the array from a read-only ByteBuffer similar to ByteBuffer.array().

Parameters:

buffer - that wraps the underlying array.

Returns:

the underlying array.

arrayOffset

public static int arrayOffset(ByteBuffer buffer)

Get the array offset from a read-only ByteBuffer similar to ByteBuffer.arrayOffset().

Parameters:

buffer - that wraps the underlying array.

Returns:

the underlying array offset at which this ByteBuffer starts.

allocateDirectAligned

public static ByteBuffer allocateDirectAligned(int capacity,
 int alignment)

Allocate a new direct ByteBuffer that is aligned on a given alignment boundary.

Note: Aligned buffers are a ByteBuffer.slice() so cannot be passed to free(ByteBuffer).

Parameters:

capacity - required for the buffer.

alignment - boundary at which the buffer should begin.

Returns:

a new ByteBuffer with the required alignment.

Throws:

IllegalArgumentException - if the alignment is not a power of 2.

free

public static void free(DirectBuffer buffer)

Free the underlying direct ByteBuffer by invoking Cleaner on it. No op if null or if the underlying ByteBuffer non-direct.

Parameters:

buffer - to be freed

See Also:

• ByteBuffer.isDirect()

free

public static void free(ByteBuffer buffer)

Free direct ByteBuffer by invoking Cleaner on it. No op if null or non-direct ByteBuffer.

Parameters:

buffer - to be freed

See Also:

• ByteBuffer.isDirect()