org.apache.sling.discovery.commons.providers.spi.base

Class ClusterSyncServiceChain

java.lang.Object

org.apache.sling.discovery.commons.providers.spi.base.ClusterSyncServiceChain

All Implemented Interfaces:

ClusterSyncService

public class ClusterSyncServiceChain
extends java.lang.Object
implements ClusterSyncService

Allows chaining of ClusterSyncService, itself implementing the ClusterSyncService interface

Field Summary

Fields

Modifier and Type	Field and Description
protected org.slf4j.Logger	logger

Constructor Summary

Constructors

Constructor and Description
ClusterSyncServiceChain(ClusterSyncService... chain) Creates a new chain of ClusterSyncService that calls a cascaded sync with the provided ClusterSyncService.

Method Summary

Modifier and Type	Method and Description
void	cancelSync()
void	sync(BaseTopologyView view, java.lang.Runnable callback) Starts the synchronization process and calls the provided callback upon completion.

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected final org.slf4j.Logger logger

Constructor Detail

ClusterSyncServiceChain

public ClusterSyncServiceChain(ClusterSyncService... chain)

Creates a new chain of ClusterSyncService that calls a cascaded sync with the provided ClusterSyncService.

Method Detail

sync

public void sync(BaseTopologyView view,
                 java.lang.Runnable callback)

Description copied from interface: ClusterSyncService

Starts the synchronization process and calls the provided callback upon completion.

sync() is not thread-safe and should not be invoked concurrently.

If sync() gets called before a previous invocation finished, that previous invocation will be discarded, ie the callback of the previous invocation will no longer be called.

The synchronization process consists of making sure that the repository has processed any potential backlog of instances that are no longer part of the provided, new view. Plus it writes a 'sync-token' to a well-defined location, with all peers doing the same, and upon seeing all other sync-tokens declares successful completion - at which point it calls the callback.run().

Specified by:

sync in interface ClusterSyncService

Parameters:

view - the view which all instances in the local cluster should agree on having seen

callback - the runnable which should be called after successful syncing

cancelSync

public void cancelSync()

Specified by:

cancelSync in interface ClusterSyncService