ByteBufferIOEngine (Apache HBase 1.2.12 API)

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 in memory using an array of ByteBuffers ByteBufferArray

Field Summary

Fields
Modifier and Type Field and Description

private ByteBufferArray bufferArray

private long capacity

private boolean direct

Fields
Modifier and Type	Field and Description
`private ByteBufferArray`	`bufferArray`
`private long`	`capacity`
`private boolean`	`direct`

Constructor Summary

Constructors
Constructor and Description

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

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

- Field Detail
  - bufferArray
```
private ByteBufferArray bufferArray
```
  - capacity
```
private final long capacity
```
  - direct
```
private final boolean direct
```
- 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

Class ByteBufferIOEngine

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

bufferArray

capacity

direct

Constructor Detail

ByteBufferIOEngine

Method Detail

toString

isPersistent

read

write

sync

shutdown