co.cask.cdap.data.stream

Interface StreamCoordinatorClient

All Superinterfaces:

com.google.common.util.concurrent.Service

All Known Implementing Classes:

AbstractStreamCoordinatorClient, DistributedStreamCoordinatorClient, InMemoryStreamCoordinatorClient

public interface StreamCoordinatorClient
extends com.google.common.util.concurrent.Service

This class responsible for process coordination needed between stream writers and consumers.

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

Method Summary

Methods

Modifier and Type	Method and Description
Cancellable	addListener(Id.Stream streamId, StreamPropertyListener listener) Receives event for changes in stream properties.
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.
<T> T	exclusiveAction(Id.Stream streamId, Callable<T> action) Performs an action on a stream while holding the lock for the stream.
void	updateProperties(Id.Stream streamId, Callable<CoordinatorStreamProperties> action) Updates the stream properties by performing the given action.

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

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

Method Detail

addListener

Cancellable addListener(Id.Stream streamId,
                      StreamPropertyListener listener)

Receives event for changes in stream properties.

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

createStream

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

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.

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

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

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.

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

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

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.

Parameters:

streamId - name of the stream

action - action to perform.

Throws:

Exception - if the action throws Exception

exclusiveAction

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

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

Parameters:

streamId - name of the stream

action - action to perform.

Throws:

Exception - if the action throws Exception