org.nustaq.offheap

Class BinaryQueue

java.lang.Object

org.nustaq.offheap.BinaryQueue

public class BinaryQueue
extends Object

an automatically growing byte queue organized as a ringbuffer. poll* methods don't throw excpetions but return incomplete or no result instead if the queue's content is not sufficient. read* methods throw excpetions in case the q contains not enough bytes (need to use available() to ensure data is present). add methods add to the queue. If the adding outperforms reading/polling, the queue is growed automatically.

Constructor Summary

Constructors

Constructor and Description
BinaryQueue()
BinaryQueue(int qsize)

Method Summary

Modifier and Type	Method and Description
void	add(byte b)
void	add(ByteSource source) add bytes to the queue.
void	add(ByteSource source, long sourceoff, long sourcelen) add bytes to the queue.
void	addInt(int written)
long	available()
void	back(int len) 'unread' len bytes
long	capacity()
protected void	grow(long sourcelen)
int	poll()
long	poll(ByteSink destination, long destoff, long destlen) read up to destlen bytes (if available).
byte[]	readByteArray(int len) convenience method to read len byte array.
int	readInt() read an int.
long	remaining()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

BinaryQueue

public BinaryQueue()

BinaryQueue

public BinaryQueue(int qsize)

Method Detail

add

public void add(ByteSource source)

add bytes to the queue. Again by using (reusable) Wrapper classes any kind of memory (offheap, byte arrays, nio bytebuffer, memory mapped) can be added.

Parameters:

source -

add

public void add(ByteSource source,
                long sourceoff,
                long sourcelen)

add bytes to the queue. Again by using (reusable) Wrapper classes any kind of memory (offheap, byte arrays, nio bytebuffer, memory mapped) can be added.

Parameters:

source -

sourceoff -

sourcelen -

addInt

public void addInt(int written)

add

public void add(byte b)

grow

protected void grow(long sourcelen)

remaining

public long remaining()

Returns:

number of bytes free for an add operation

poll

public long poll(ByteSink destination,
                 long destoff,
                 long destlen)

read up to destlen bytes (if available). Note you can use HeapBytez (implements ByteSink) in order to read to a regular byte array. HeapBytez wrapper can be reused to avoid unnecessary allocation. Also possible is ByteBufferBasicBytes to read into a ByteBuffer and MallocBytes or MMFBytes to read into Unsafe alloc'ed off heap memory or persistent mem mapped memory regions.

Parameters:

destination -

destoff -

destlen -

Returns:

readByteArray

public byte[] readByteArray(int len)

convenience method to read len byte array. Throws an excpetion if not enough data is present

Parameters:

len -

Returns:

readInt

public int readInt()

read an int. throws an exception if not enough data is present

Returns:

poll

public int poll()

Returns:

-1 or the next byte unsigned value

back

public void back(int len)

'unread' len bytes

Parameters:

len -

available

public long available()

Returns:

number of readable bytes

capacity

public long capacity()

Returns:

size of underlying ringbuffer

toString

public String toString()

Overrides:

toString in class Object