de.ruedigermoeller.heapoff

Class FSTOffheapQueue

java.lang.Object

de.ruedigermoeller.heapoff.FSTOffheapQueue

public class FSTOffheapQueue
extends Object

UNRELEASED UNTESTED ! a queue based on off heap memory. The advantage is, that objects are serialized at the time you add them to the queue. This has several advantages (Client/Server related) - the size of the queue is defined in memory size, not number of objects (no risk to get OOM) - queues do not suck CPU indirectly by being subject to garbage collection - if a message is added to multiple queues, you actually serialize this message once, then copy the resulting bytes - its easier to control network message size, as you already know the size of a serialized object - recovery in case you use memory mapped files (additional work requrired) - concurrent encoding/decoding to make use of multicore cpus Once a message is sent to a client, a bunch of bytes is taken from the queue.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	FSTOffheapQueue.ByteBufferResult
class	FSTOffheapQueue.ConcurrentReadContext
class	FSTOffheapQueue.ConcurrentWriteContext

Constructor Summary

Constructors

Constructor and Description
FSTOffheapQueue(ByteBuffer buffer)
FSTOffheapQueue(ByteBuffer buffer, int numThreads)
FSTOffheapQueue(int sizeMB)
FSTOffheapQueue(int sizeMB, int numThreads)

Method Summary

Modifier and Type	Method and Description
boolean	add(Object o)
boolean	addBytes(byte[] b)
void	addConcurrent(Object o) perform multi threaded encoding.
FSTOffheapQueue.ConcurrentReadContext	createConcurrentReader()
FSTOffheapQueue.ConcurrentWriteContext	createConcurrentWriter()
boolean	takeBytes(FSTOffheapQueue.ByteBufferResult res)
Object	takeObject(int[] sizeResult)
Object	takeObjectConcurrent()
void	waitForFinish()

Methods inherited from class java.lang.Object

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

Constructor Detail

FSTOffheapQueue

public FSTOffheapQueue(int sizeMB)
                throws IOException

Throws:

IOException

FSTOffheapQueue

public FSTOffheapQueue(int sizeMB,
                       int numThreads)
                throws IOException

Throws:

IOException

FSTOffheapQueue

public FSTOffheapQueue(ByteBuffer buffer)
                throws IOException

Throws:

IOException

FSTOffheapQueue

public FSTOffheapQueue(ByteBuffer buffer,
                       int numThreads)
                throws IOException

Throws:

IOException

Method Detail

addBytes

public boolean addBytes(byte[] b)
                 throws IOException

Throws:

IOException

add

public boolean add(Object o)
            throws IOException

Throws:

IOException

addConcurrent

public void addConcurrent(Object o)
                   throws IOException,
                          ExecutionException,
                          InterruptedException

perform multi threaded encoding. Note that depending on object size, you need up to 4 threads in order to break even. If complex objects are added to the queue you'll need fewer threads to break even. Scales well with multicore/hyperthreaded intel cpu's. The order of add's is kept (fifo), only encoding is done concurrent. It has been tested, that with 8 threads on multicore servers a speed up of > 400% is possible.

Parameters:

o -

Throws:

IOException

ExecutionException

InterruptedException

waitForFinish

public void waitForFinish()
                   throws InterruptedException

Throws:

InterruptedException

createConcurrentWriter

public FSTOffheapQueue.ConcurrentWriteContext createConcurrentWriter()

createConcurrentReader

public FSTOffheapQueue.ConcurrentReadContext createConcurrentReader()
                                                             throws IOException

Throws:

IOException

takeObject

public Object takeObject(int[] sizeResult)
                  throws ClassNotFoundException,
                         InstantiationException,
                         IllegalAccessException,
                         IOException

Throws:

ClassNotFoundException

InstantiationException

IllegalAccessException

IOException

takeObjectConcurrent

public Object takeObjectConcurrent()
                            throws InterruptedException

Throws:

InterruptedException

takeBytes

public boolean takeBytes(FSTOffheapQueue.ByteBufferResult res)
                  throws ClassNotFoundException,
                         InstantiationException,
                         IllegalAccessException,
                         IOException

Throws:

ClassNotFoundException

InstantiationException

IllegalAccessException

IOException