Package org.apache.druid.java.util.common

Class ByteBufferUtils

java.lang.Object

org.apache.druid.java.util.common.ByteBufferUtils

public class ByteBufferUtils
extends Object

Constructor Summary

Constructors

Constructor	Description
ByteBufferUtils()

Method Summary

Modifier and Type	Method	Description
static ResourceHolder<ByteBuffer>	allocateDirect(int size)	Same as ByteBuffer.allocateDirect(int), but returns a closeable ResourceHolder that frees the buffer upon close.
static int	compareUtf8ByteBuffers(ByteBuffer buf1, ByteBuffer buf2)	Compares two ByteBuffers from their positions to their limits using ordering consistent with String.compareTo(String).
static void	free(ByteBuffer buffer)	Releases memory held by the given direct ByteBuffer
static void	unmap(MappedByteBuffer buffer)	Un-maps the given memory mapped file
static Comparator<ByteBuffer>	utf8Comparator()	Comparator that compares two ByteBuffer using ordering consistent with String.compareTo(String).
static ByteBuffer	wrapLE(byte[] array)	Wraps a byte array in a little-endian ByteBuffer.
static ByteBuffer	wrapLE(byte[] array, int offset, int length)	Wraps a portion of a byte array in a little-endian ByteBuffer.

Methods inherited from class java.lang.Object

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

Constructor Details

ByteBufferUtils

public ByteBufferUtils()

Method Details

allocateDirect

public static ResourceHolder<ByteBuffer> allocateDirect(int size)

Same as ByteBuffer.allocateDirect(int), but returns a closeable ResourceHolder that frees the buffer upon close. Direct (off-heap) buffers are an alternative to on-heap buffers that allow memory to be managed outside the purview of the garbage collector. It's most useful when allocating big chunks of memory, like processing buffers. Holders cannot be closed more than once. Attempting to close a holder twice will earn you an IllegalStateException.

free

public static void free(ByteBuffer buffer)

Releases memory held by the given direct ByteBuffer

Parameters:

buffer - buffer to free

unmap

public static void unmap(MappedByteBuffer buffer)

Un-maps the given memory mapped file

Parameters:

buffer - buffer

compareUtf8ByteBuffers

public static int compareUtf8ByteBuffers(@Nullable
 ByteBuffer buf1,
 @Nullable
 ByteBuffer buf2)

Compares two ByteBuffers from their positions to their limits using ordering consistent with String.compareTo(String). Null buffers are accepted, and are ordered earlier than any nonnull buffer. Different from ByteBuffer.compareTo(java.nio.ByteBuffer), which uses signed-bytes ordering.

utf8Comparator

public static Comparator<ByteBuffer> utf8Comparator()

Comparator that compares two ByteBuffer using ordering consistent with String.compareTo(String). Null buffers are accepted, and are ordered earlier than any nonnull buffer.

wrapLE

public static ByteBuffer wrapLE(byte[] array)

Wraps a byte array in a little-endian ByteBuffer.

Parameters:

array - byte array to wrap

Returns:

ByteBuffer wrapping the array with little-endian byte order

wrapLE

public static ByteBuffer wrapLE(byte[] array,
 int offset,
 int length)

Wraps a portion of a byte array in a little-endian ByteBuffer.

Parameters:

array - byte array to wrap

offset - offset within the array

length - length of the region to wrap

Returns:

ByteBuffer wrapping the specified portion with little-endian byte order