org.apache.flink.runtime.memorymanager

Class SimpleMemorySegment

java.lang.Object

org.apache.flink.runtime.memorymanager.SimpleMemorySegment

public class SimpleMemorySegment
extends Object

This class represents a piece of memory allocated from the memory manager. The segment is backed by a byte array and features random put and get methods for the basic types that are stored in a byte-wise fashion in the memory.

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	memory The array in which the data is stored.
protected ByteBuffer	wrapper Wrapper for I/O requests.

Constructor Summary

Constructors

Constructor and Description
SimpleMemorySegment(byte[] memory) Creates a new memory segment of given size with the provided views.

Method Summary

Methods

Modifier and Type	Method and Description
void	get(DataOutput out, int offset, int length)
byte	get(int index)
void	get(int index, byte[] dst)
void	get(int index, byte[] dst, int offset, int length)
byte[]	getBackingArray() Gets the byte array that backs the memory segment and this random access view.
boolean	getBoolean(int index)
char	getChar(int index)
double	getDouble(int index)
float	getFloat(int index)
int	getInt(int index)
int	getIntBigEndian(int index)
int	getIntLittleEndian(int index)
long	getLong(int index)
long	getLongBigEndian(int index)
long	getLongLittleEndian(int index)
short	getShort(int index)
boolean	isFreed() Checks whether this memory segment has already been freed.
void	put(DataInput in, int offset, int length)
void	put(int index, byte b)
void	put(int index, byte[] src)
void	put(int index, byte[] src, int offset, int length)
void	putBoolean(int index, boolean value)
void	putChar(int index, char value)
void	putDouble(int index, double value)
void	putFloat(int index, float value)
void	putInt(int index, int value)
void	putIntBigEndian(int index, int value)
void	putIntLittleEndian(int index, int value)
void	putLong(int index, long value)
void	putLongBigEndian(int index, long value)
void	putLongLittleEndian(int index, long value)
void	putShort(int index, short value)
int	size() Gets the size of the memory segment, in bytes.
int	translateOffset(int offset) Translates the given offset for this view into the offset for the backing array.
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 java.lang.Object

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

Field Detail

memory

protected byte[] memory

The array in which the data is stored.

wrapper

protected ByteBuffer wrapper

Wrapper for I/O requests.

Constructor Detail

SimpleMemorySegment

public SimpleMemorySegment(byte[] memory)

Creates a new memory segment of given size with the provided views.

Method Detail

isFreed

public final boolean isFreed()

Checks whether this memory segment has already been freed. In that case, the segment must not be used any more.

Returns:

True, if the segment has been freed, false otherwise.

size

public final int size()

Gets the size of the memory segment, in bytes. Because segments are backed by arrays, they cannot be larger than two GiBytes.

Returns:

The size in bytes.

getBackingArray

public final byte[] getBackingArray()

Gets the byte array that backs the memory segment and this random access view. Since different regions of the backing array are used by different segments, the logical positions in this view do not correspond to the indexes in the backing array and need to be translated via the translateOffset(int) method.

Returns:

The backing byte array.

translateOffset

public final int translateOffset(int offset)

Translates the given offset for this view into the offset for the backing array.

Parameters:

offset - The offset to be translated.

Returns:

The corresponding position in the backing array.

wrap

public ByteBuffer wrap(int offset,
              int length)

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

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.

Throws:

IndexOutOfBoundsException - Thrown, if offset is negative or larger than the memory segment size, or if the offset plus the length is larger than the segment size.

get

public final byte get(int index)

put

public final void put(int index,
       byte b)

get

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

put

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

get

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

put

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

get

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

Throws:

IOException

put

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

Throws:

IOException

getBoolean

public final boolean getBoolean(int index)

putBoolean

public final void putBoolean(int index,
              boolean value)

getChar

public final char getChar(int index)

putChar

public final void putChar(int index,
           char value)

getShort

public final short getShort(int index)

putShort

public final void putShort(int index,
            short value)

getInt

public final int getInt(int index)

getIntLittleEndian

public final int getIntLittleEndian(int index)

getIntBigEndian

public final int getIntBigEndian(int index)

putInt

public final void putInt(int index,
          int value)

putIntLittleEndian

public final void putIntLittleEndian(int index,
                      int value)

putIntBigEndian

public final void putIntBigEndian(int index,
                   int value)

getLong

public final long getLong(int index)

getLongLittleEndian

public final long getLongLittleEndian(int index)

getLongBigEndian

public final long getLongBigEndian(int index)

putLong

public final void putLong(int index,
           long value)

putLongLittleEndian

public final void putLongLittleEndian(int index,
                       long value)

putLongBigEndian

public final void putLongBigEndian(int index,
                    long value)

getFloat

public final float getFloat(int index)

putFloat

public final void putFloat(int index,
            float value)

getDouble

public final double getDouble(int index)

putDouble

public final void putDouble(int index,
             double value)