org.apache.hadoop.hbase.regionserver

类 Chunk

java.lang.Object

org.apache.hadoop.hbase.regionserver.Chunk

直接已知子类:

OffheapChunk, OnheapChunk

@InterfaceAudience.Private
public abstract class Chunk
extends Object

A chunk of memory out of which allocations are sliced.

字段概要

字段

限定符和类型	字段和说明
protected AtomicInteger	allocCount Total number of allocations satisfied from this buffer
protected ByteBuffer	data Actual underlying data
protected AtomicInteger	nextFreeOffset Offset for the next allocation, or the sentinel value -1 which implies that the chunk is still uninitialized.
protected static int	OOM
protected int	size Size of chunk in bytes
protected static int	UNINITIALIZED

构造器概要

构造器

构造器和说明
Chunk(int size, int id) Create an uninitialized chunk.
Chunk(int size, int id, boolean fromPool) Create an uninitialized chunk.

方法概要

限定符和类型	方法和说明
int	alloc(int size) Try to allocate size bytes from the chunk.
void	init() Actually claim the memory for this chunk.
String	toString()

从类继承的方法 java.lang.Object

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

字段详细资料

data

protected ByteBuffer data

Actual underlying data

UNINITIALIZED

protected static final int UNINITIALIZED

另请参阅:

常量字段值

OOM

protected static final int OOM

另请参阅:

常量字段值

nextFreeOffset

protected AtomicInteger nextFreeOffset

Offset for the next allocation, or the sentinel value -1 which implies that the chunk is still uninitialized.

allocCount

protected AtomicInteger allocCount

Total number of allocations satisfied from this buffer

size

protected final int size

Size of chunk in bytes

构造器详细资料

Chunk

public Chunk(int size,
             int id)

Create an uninitialized chunk. Note that memory is not allocated yet, so this is cheap.

参数:

size - in bytes

id - the chunk id

Chunk

public Chunk(int size,
             int id,
             boolean fromPool)

Create an uninitialized chunk. Note that memory is not allocated yet, so this is cheap.

参数:

size - in bytes

id - the chunk id

fromPool - if the chunk is formed by pool

方法详细资料

init

public void init()

Actually claim the memory for this chunk. This should only be called from the thread that constructed the chunk. It is thread-safe against other threads calling alloc(), who will block until the allocation is complete.

alloc

public int alloc(int size)

Try to allocate size bytes from the chunk. If a chunk is tried to get allocated before init() call, the thread doing the allocation will be in busy-wait state as it will keep looping till the nextFreeOffset is set.

返回:

the offset of the successful allocation, or -1 to indicate not-enough-space

toString

public String toString()

覆盖:

toString 在类中 Object