co.cask.cdap.data.stream

Class AbstractStreamCoordinatorClient

java.lang.Object

com.google.common.util.concurrent.AbstractIdleService

co.cask.cdap.data.stream.AbstractStreamCoordinatorClient

All Implemented Interfaces:

StreamCoordinatorClient, com.google.common.util.concurrent.Service

Direct Known Subclasses:

DistributedStreamCoordinatorClient, InMemoryStreamCoordinatorClient

public abstract class AbstractStreamCoordinatorClient
extends com.google.common.util.concurrent.AbstractIdleService
implements StreamCoordinatorClient

Base implementation for StreamCoordinatorClient.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service

com.google.common.util.concurrent.Service.Listener, com.google.common.util.concurrent.Service.State

Constructor Summary

Constructors

Constructor and Description
AbstractStreamCoordinatorClient()

Method Summary

Methods

Modifier and Type	Method and Description
Cancellable	addListener(Id.Stream streamId, StreamPropertyListener listener) Receives event for changes in stream properties.
protected abstract <T> PropertyStore<T>	createPropertyStore(Codec<T> codec) Creates a PropertyStore.
StreamConfig	createStream(Id.Stream streamId, Callable<StreamConfig> action) Creates a stream by performing the given action.
void	deleteStream(Id.Stream streamId, Runnable action) Deletes a stream by performing the given action.
protected abstract void	doShutDown() Stops the service.
protected abstract void	doStartUp() Starts the service.
<T> T	exclusiveAction(Id.Stream streamId, Callable<T> action) Performs an action on a stream while holding the lock for the stream.
protected abstract Lock	getLock(Id.Stream streamId) Returns a Lock for performing exclusive operation for the given stream.
protected void	shutDown()
protected void	startUp()
protected abstract void	streamCreated(Id.Stream streamId) Gets invoked when a stream of the given name is created.
protected abstract void	streamDeleted(Id.Stream streamId) Gets invoked when a stream is deleted.
void	updateProperties(Id.Stream streamId, Callable<CoordinatorStreamProperties> action) Updates the stream properties by performing the given action.

Methods inherited from class com.google.common.util.concurrent.AbstractIdleService

addListener, executor, isRunning, start, startAndWait, state, stop, stopAndWait, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.google.common.util.concurrent.Service

addListener, isRunning, start, startAndWait, state, stop, stopAndWait

Constructor Detail

AbstractStreamCoordinatorClient

public AbstractStreamCoordinatorClient()

Method Detail

doStartUp

protected abstract void doStartUp()
                           throws Exception

Starts the service.

Throws:

Exception - when starting of the service failed

doShutDown

protected abstract void doShutDown()
                            throws Exception

Stops the service.

Throws:

Exception - when stopping the service could not be performed

createPropertyStore

protected abstract <T> PropertyStore<T> createPropertyStore(Codec<T> codec)

Creates a PropertyStore.

Type Parameters:

T - Type of the property

Parameters:

codec - Codec for the property stored in the property store

Returns:

A new PropertyStore.

getLock

protected abstract Lock getLock(Id.Stream streamId)

Returns a Lock for performing exclusive operation for the given stream.

streamCreated

protected abstract void streamCreated(Id.Stream streamId)

Gets invoked when a stream of the given name is created.

streamDeleted

protected abstract void streamDeleted(Id.Stream streamId)

Gets invoked when a stream is deleted.

createStream

public StreamConfig createStream(Id.Stream streamId,
                        Callable<StreamConfig> action)
                          throws Exception

Description copied from interface: StreamCoordinatorClient

Creates a stream by performing the given action. The execution of the action is protected by a lock so that it is guaranteed that there is only one thread executing the given action for the given stream across the whole system.

Specified by:

createStream in interface StreamCoordinatorClient

Parameters:

streamId - name of the stream

action - action to perform. If a new stream is created, it should returns a StreamConfig representing the configuration of the new stream; otherwise null should be returned.

Returns:

The StreamConfig as returned by the action

Throws:

Exception - if the action throws Exception

updateProperties

public void updateProperties(Id.Stream streamId,
                    Callable<CoordinatorStreamProperties> action)
                      throws Exception

Description copied from interface: StreamCoordinatorClient

Updates the stream properties by performing the given action. The execution of the action is protected by a lock so that it is guaranteed that there is only one thread executing the given action for the given stream across the whole system.

Specified by:

updateProperties in interface StreamCoordinatorClient

Parameters:

streamId - name of the stream

action - action to perform. It should returns a CoordinatorStreamProperties containing information about the update properties.

Throws:

Exception - if failed to update properties

deleteStream

public void deleteStream(Id.Stream streamId,
                Runnable action)
                  throws Exception

Description copied from interface: StreamCoordinatorClient

Deletes a stream by performing the given action. The execution of the action is protected by a lock so that it is guaranteed that there is only only thread executing the given action for the given stream across the whole system.

Specified by:

deleteStream in interface StreamCoordinatorClient

Parameters:

streamId - name of the stream

action - action to perform.

Throws:

Exception - if the action throws Exception

exclusiveAction

public <T> T exclusiveAction(Id.Stream streamId,
                    Callable<T> action)
                  throws Exception

Description copied from interface: StreamCoordinatorClient

Performs an action on a stream while holding the lock for the stream.

Specified by:

exclusiveAction in interface StreamCoordinatorClient

Parameters:

streamId - name of the stream

action - action to perform.

Throws:

Exception - if the action throws Exception

addListener

public Cancellable addListener(Id.Stream streamId,
                      StreamPropertyListener listener)

Description copied from interface: StreamCoordinatorClient

Receives event for changes in stream properties.

Specified by:

addListener in interface StreamCoordinatorClient

Parameters:

streamId - name of the stream

listener - listener to get called when there is change in stream properties.

Returns:

A Cancellable to cancel the watch

startUp

protected final void startUp()
                      throws Exception

Specified by:

startUp in class com.google.common.util.concurrent.AbstractIdleService

Throws:

Exception

shutDown

protected final void shutDown()
                       throws Exception

Specified by:

shutDown in class com.google.common.util.concurrent.AbstractIdleService

Throws:

Exception