org.apache.hadoop.hbase.io

类 ByteBufferPool

java.lang.Object

org.apache.hadoop.hbase.io.ByteBufferPool

@InterfaceAudience.Private
public class ByteBufferPool
extends Object

Like Hadoops' ByteBufferPool only you do not specify desired size when getting a ByteBuffer. This pool keeps an upper bound on the count of ByteBuffers in the pool and a fixed size of ByteBuffer that it will create. When requested, if a free ByteBuffer is already present, it will return that. And when no free ByteBuffer available and we are below the max count, it will create a new one and return that.

Note: This pool returns off heap ByteBuffers by default. If on heap ByteBuffers to be pooled, pass 'directByteBuffer' as false while construction of the pool.

This class is thread safe.

另请参阅:

ByteBufferListOutputStream

字段概要

字段

限定符和类型	字段和说明
static String	BUFFER_SIZE_KEY
static int	DEFAULT_BUFFER_SIZE
static String	MAX_POOL_SIZE_KEY

构造器概要

构造器

构造器和说明
ByteBufferPool(int bufferSize, int maxPoolSize)
ByteBufferPool(int bufferSize, int maxPoolSize, boolean directByteBuffer)

方法概要

限定符和类型	方法和说明
ByteBuffer	getBuffer()
int	getBufferSize()
int	getQueueSize()
void	putbackBuffer(ByteBuffer buf) Return back a ByteBuffer after its use.

从类继承的方法 java.lang.Object

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

字段详细资料

MAX_POOL_SIZE_KEY

public static final String MAX_POOL_SIZE_KEY

另请参阅:

常量字段值

BUFFER_SIZE_KEY

public static final String BUFFER_SIZE_KEY

另请参阅:

常量字段值

DEFAULT_BUFFER_SIZE

public static final int DEFAULT_BUFFER_SIZE

另请参阅:

常量字段值

构造器详细资料

ByteBufferPool

public ByteBufferPool(int bufferSize,
                      int maxPoolSize)

参数:

bufferSize - Size of each buffer created by this pool.

maxPoolSize - Max number of buffers to keep in this pool.

ByteBufferPool

public ByteBufferPool(int bufferSize,
                      int maxPoolSize,
                      boolean directByteBuffer)

参数:

bufferSize - Size of each buffer created by this pool.

maxPoolSize - Max number of buffers to keep in this pool.

directByteBuffer - Whether to create direct ByteBuffer or on heap ByteBuffer.

方法详细资料

getBuffer

public ByteBuffer getBuffer()

返回:

One free ByteBuffer from the pool. If no free ByteBuffer and we have not reached the maximum pool size, it will create a new one and return. In case of max pool size also reached, will return null. When pool returned a ByteBuffer, make sure to return it back to pool after use.

另请参阅:

putbackBuffer(ByteBuffer)

putbackBuffer

public void putbackBuffer(ByteBuffer buf)

Return back a ByteBuffer after its use. Do not try to return put back a ByteBuffer, not obtained from this pool.

参数:

buf - ByteBuffer to return.

getBufferSize

public int getBufferSize()

getQueueSize

public int getQueueSize()

返回:

Number of free buffers