org.apache.flink.core.memory

Class HybridMemorySegment

java.lang.Object

org.apache.flink.core.memory.MemorySegment

org.apache.flink.core.memory.HybridMemorySegment

@Internal
public final class HybridMemorySegment
extends MemorySegment

This class represents a piece of memory managed by Flink. The memory can be on-heap or off-heap, this is transparently handled by this class.

This class specialized byte access and byte copy calls for heap memory, while reusing the multi-byte type accesses and cross-segment operations from the MemorySegment.

This class subsumes the functionality of the HeapMemorySegment, but is a bit less efficient for operations on individual bytes.

Note that memory segments should usually not be allocated manually, but rather through the MemorySegmentFactory.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HybridMemorySegment.HybridMemorySegmentFactory Base factory for hybrid memory segments.

Field Summary

Fields

Modifier and Type	Field and Description
static HybridMemorySegment.HybridMemorySegmentFactory	FACTORY

Fields inherited from class org.apache.flink.core.memory.MemorySegment

address, addressLimit, BYTE_ARRAY_BASE_OFFSET, heapMemory, size, UNSAFE

Method Summary

Modifier and Type	Method and Description
void	get(DataOutput out, int offset, int length)
byte	get(int index) Reads the byte at the given position.
void	get(int index, byte[] dst) Bulk get method.
void	get(int index, byte[] dst, int offset, int length) Bulk get method.
void	get(int offset, ByteBuffer target, int numBytes) Bulk get method.
byte[]	getArray()
boolean	getBoolean(int index) Reads one byte at the given position and returns its boolean representation.
ByteBuffer	getOffHeapBuffer() Gets the buffer that owns the memory of this memory segment.
void	put(DataInput in, int offset, int length) Bulk put method.
void	put(int index, byte b) Writes the given byte into this buffer at the given position.
void	put(int index, byte[] src) Bulk put method.
void	put(int index, byte[] src, int offset, int length) Bulk put method.
void	put(int offset, ByteBuffer source, int numBytes) Bulk put method.
void	putBoolean(int index, boolean value) Writes one byte containing the byte value into this buffer at the given position.
ByteBuffer	wrap(int offset, int length) Wraps the chunk of the underlying memory located between offset and length in a NIO ByteBuffer.

Methods inherited from class org.apache.flink.core.memory.MemorySegment

compare, copyTo, free, getChar, getCharBigEndian, getCharLittleEndian, getDouble, getDoubleBigEndian, getDoubleLittleEndian, getFloat, getFloatBigEndian, getFloatLittleEndian, getInt, getIntBigEndian, getIntLittleEndian, getLong, getLongBigEndian, getLongLittleEndian, getOwner, getShort, getShortBigEndian, getShortLittleEndian, isFreed, isOffHeap, putChar, putCharBigEndian, putCharLittleEndian, putDouble, putDoubleBigEndian, putDoubleLittleEndian, putFloat, putFloatBigEndian, putFloatLittleEndian, putInt, putIntBigEndian, putIntLittleEndian, putLong, putLongBigEndian, putLongLittleEndian, putShort, putShortBigEndian, putShortLittleEndian, size, swapBytes

Methods inherited from class java.lang.Object

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

Field Detail

FACTORY

public static final HybridMemorySegment.HybridMemorySegmentFactory FACTORY

Method Detail

getArray

public byte[] getArray()

getOffHeapBuffer

public ByteBuffer getOffHeapBuffer()

Gets the buffer that owns the memory of this memory segment.

Returns:

The byte buffer that owns the memory of this memory segment.

wrap

public ByteBuffer wrap(int offset,
                       int length)

Description copied from class: MemorySegment

Wraps the chunk of the underlying memory located between offset and length in a NIO ByteBuffer.

Specified by:

wrap in class MemorySegment

Parameters:

offset - The offset in the memory segment.

length - The number of bytes to be wrapped as a buffer.

Returns:

A ByteBuffer backed by the specified portion of the memory segment.

get

public byte get(int index)

Description copied from class: MemorySegment

Reads the byte at the given position.

Specified by:

get in class MemorySegment

Parameters:

index - The position from which the byte will be read

Returns:

The byte at the given position.

put

public void put(int index,
                byte b)

Description copied from class: MemorySegment

Writes the given byte into this buffer at the given position.

Specified by:

put in class MemorySegment

Parameters:

index - The index at which the byte will be written.

b - The byte value to be written.

get

public void get(int index,
                byte[] dst)

Description copied from class: MemorySegment

Bulk get method. Copies dst.length memory from the specified position to the destination memory.

Specified by:

get in class MemorySegment

Parameters:

index - The position at which the first byte will be read.

dst - The memory into which the memory will be copied.

put

public void put(int index,
                byte[] src)

Description copied from class: MemorySegment

Bulk put method. Copies src.length memory from the source memory into the memory segment beginning at the specified position.

Specified by:

put in class MemorySegment

Parameters:

index - The index in the memory segment array, where the data is put.

src - The source array to copy the data from.

get

public void get(int index,
                byte[] dst,
                int offset,
                int length)

Description copied from class: MemorySegment

Bulk get method. Copies length memory from the specified position to the destination memory, beginning at the given offset

Specified by:

get in class MemorySegment

Parameters:

index - The position at which the first byte will be read.

dst - The memory into which the memory will be copied.

offset - The copying offset in the destination memory.

length - The number of bytes to be copied.

put

public void put(int index,
                byte[] src,
                int offset,
                int length)

Description copied from class: MemorySegment

Bulk put method. Copies length memory starting at position offset from the source memory into the memory segment starting at the specified index.

Specified by:

put in class MemorySegment

Parameters:

index - The position in the memory segment array, where the data is put.

src - The source array to copy the data from.

offset - The offset in the source array where the copying is started.

length - The number of bytes to copy.

getBoolean

public boolean getBoolean(int index)

Description copied from class: MemorySegment

Reads one byte at the given position and returns its boolean representation.

Specified by:

getBoolean in class MemorySegment

Parameters:

index - The position from which the memory will be read.

Returns:

The boolean value at the given position.

putBoolean

public void putBoolean(int index,
                       boolean value)

Description copied from class: MemorySegment

Writes one byte containing the byte value into this buffer at the given position.

Specified by:

putBoolean in class MemorySegment

Parameters:

index - The position at which the memory will be written.

value - The char value to be written.

get

public final void get(DataOutput out,
                      int offset,
                      int length)
               throws IOException

Specified by:

get in class MemorySegment

Throws:

IOException

put

public final void put(DataInput in,
                      int offset,
                      int length)
               throws IOException

Description copied from class: MemorySegment

Bulk put method. Copies length memory from the given DataInput to the memory starting at position offset.

Specified by:

put in class MemorySegment

Parameters:

in - The DataInput to get the data from.

offset - The position in the memory segment to copy the chunk to.

length - The number of bytes to get.

Throws:

IOException - Thrown, if the DataInput encountered a problem upon reading, such as an End-Of-File.

get

public final void get(int offset,
                      ByteBuffer target,
                      int numBytes)

Description copied from class: MemorySegment

Bulk get method. Copies numBytes bytes from this memory segment, starting at position offset to the target ByteBuffer. The bytes will be put into the target buffer starting at the buffer's current position. If this method attempts to write more bytes than the target byte buffer has remaining (with respect to Buffer.remaining()), this method will cause a BufferOverflowException.

Specified by:

get in class MemorySegment

Parameters:

offset - The position where the bytes are started to be read from in this memory segment.

target - The ByteBuffer to copy the bytes to.

numBytes - The number of bytes to copy.

put

public final void put(int offset,
                      ByteBuffer source,
                      int numBytes)

Description copied from class: MemorySegment

Bulk put method. Copies numBytes bytes from the given ByteBuffer, into this memory segment. The bytes will be read from the target buffer starting at the buffer's current position, and will be written to this memory segment starting at offset. If this method attempts to read more bytes than the target byte buffer has remaining (with respect to Buffer.remaining()), this method will cause a BufferUnderflowException.

Specified by:

put in class MemorySegment

Parameters:

offset - The position where the bytes are started to be written to in this memory segment.

source - The ByteBuffer to copy the bytes from.

numBytes - The number of bytes to copy.