org.apache.hadoop.hbase.io.hfile.bucket

Class ByteBufferIOEngine

java.lang.Object

org.apache.hadoop.hbase.io.hfile.bucket.ByteBufferIOEngine

All Implemented Interfaces:

IOEngine

@InterfaceAudience.Private
public class ByteBufferIOEngine
extends Object
implements IOEngine

IO engine that stores data on the memory using an array of ByteBuffers ByteBufferArray

Constructor Summary

Constructors

Constructor and Description
ByteBufferIOEngine(long capacity, boolean direct) Construct the ByteBufferIOEngine with the given capacity

Method Summary

Methods

Modifier and Type	Method and Description
boolean	isPersistent() Memory IO engine is always unable to support persistent storage for the cache
int	read(ByteBuffer dstBuffer, long offset) Transfers data from the buffer array to the given byte buffer
void	shutdown() No operation for the shutdown in the memory IO engine
void	sync() No operation for the sync in the memory IO engine
String	toString()
void	write(ByteBuffer srcBuffer, long offset) Transfers data from the given byte buffer to the buffer array

Methods inherited from class java.lang.Object

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

Constructor Detail

ByteBufferIOEngine

public ByteBufferIOEngine(long capacity,
                  boolean direct)
                   throws IOException

Construct the ByteBufferIOEngine with the given capacity

Parameters:

capacity -

direct - true if allocate direct buffer

Throws:

IOException

Method Detail

toString

public String toString()

Overrides:

toString in class Object

isPersistent

public boolean isPersistent()

Memory IO engine is always unable to support persistent storage for the cache

Specified by:

isPersistent in interface IOEngine

Returns:

false

read

public int read(ByteBuffer dstBuffer,
       long offset)
         throws IOException

Transfers data from the buffer array to the given byte buffer

Specified by:

read in interface IOEngine

Parameters:

dstBuffer - the given byte buffer into which bytes are to be written

offset - The offset in the ByteBufferArray of the first byte to be read

Returns:

number of bytes read

Throws:

IOException

write

public void write(ByteBuffer srcBuffer,
         long offset)
           throws IOException

Transfers data from the given byte buffer to the buffer array

Specified by:

write in interface IOEngine

Parameters:

srcBuffer - the given byte buffer from which bytes are to be read

offset - The offset in the ByteBufferArray of the first byte to be written

Throws:

IOException

sync

public void sync()

No operation for the sync in the memory IO engine

Specified by:

sync in interface IOEngine

shutdown

public void shutdown()

No operation for the shutdown in the memory IO engine

Specified by:

shutdown in interface IOEngine