com.continuent.tungsten.replicator.thl
Class THLParallelReadTask

java.lang.Object
  com.continuent.tungsten.replicator.thl.THLParallelReadTask

All Implemented Interfaces:

java.lang.Runnable

public class THLParallelReadTask
extends java.lang.Object
implements java.lang.Runnable

Performs coordinated reads on the THL on behalf of a particular client (a task thread) and buffers log records up to a local limit.

Version:

1.0

Author:

Robert Hodges

Constructor Summary

THLParallelReadTask(int taskId, THL thl, Partitioner partitioner, AtomicCounter headSeqnoCounter, AtomicIntervalGuard<?> intervalGuard, int maxSize, int maxControlEvents, int syncInterval, com.continuent.tungsten.fsm.event.EventDispatcher dispatcher)
Instantiate a read task.

Method Summary

void	addWatchSyncPredicate(WatchPredicate<ReplDBMSHeader> predicate) Adds a watch predicate.
ReplEvent	get() Removes and returns next event from the queue, blocking if empty.
ReplEvent	peek() Returns but does not remove next event from the queue if it exists or returns null if queue is empty.
void	prepare(PluginContext context) Connect to THL and seek start sequence number.
void	putControlEvent(ReplControlEvent controlEvent) Inserts a control event.
void	release() Terminate reader task and free all resources.
void	run() Implements read loop on the log to feed event queue.
void	setRestartHeader(ReplDBMSHeader header) Set the starting header.
int	size() Returns the current queue size.
void	start() Start the task thread.
void	stop() Cancel the thread.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

THLParallelReadTask

public THLParallelReadTask(int taskId,
                           THL thl,
                           Partitioner partitioner,
                           AtomicCounter headSeqnoCounter,
                           AtomicIntervalGuard<?> intervalGuard,
                           int maxSize,
                           int maxControlEvents,
                           int syncInterval,
                           com.continuent.tungsten.fsm.event.EventDispatcher dispatcher)

Instantiate a read task.

Method Detail

setRestartHeader

public void setRestartHeader(ReplDBMSHeader header)

Set the starting header. This must be called before prepare().

prepare

public void prepare(PluginContext context)
             throws ReplicatorException,
                    java.lang.InterruptedException

Connect to THL and seek start sequence number. Must be called before run().

Throws:

ReplicatorException

java.lang.InterruptedException

start

public void start()

Start the task thread. This must be called after prepare.

stop

public void stop()

Cancel the thread. This must be called prior to release.

release

public void release()

Terminate reader task and free all resources. Must be called following run().

run

public void run()

Implements read loop on the log to feed event queue.

Specified by:

run in interface java.lang.Runnable

size

public int size()

Returns the current queue size.

get

public ReplEvent get()
              throws java.lang.InterruptedException,
                     ReplicatorException

Removes and returns next event from the queue, blocking if empty. This call blocks if no event is available. Internally it polls so that we correctly detect if the thread has failed.

Returns:

The next event in the queue

Throws:

java.lang.InterruptedException - Thrown if method is interrupted

ReplicatorException - Thrown if the reader thread has failed

peek

public ReplEvent peek()
               throws java.lang.InterruptedException

Returns but does not remove next event from the queue if it exists or returns null if queue is empty.

Throws:

java.lang.InterruptedException

putControlEvent

public void putControlEvent(ReplControlEvent controlEvent)
                     throws java.lang.InterruptedException

Inserts a control event.

Throws:

java.lang.InterruptedException

addWatchSyncPredicate

public void addWatchSyncPredicate(WatchPredicate<ReplDBMSHeader> predicate)
                           throws java.lang.InterruptedException

Adds a watch predicate.

Throws:

java.lang.InterruptedException

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()