org.apache.sling.discovery.base.commons

Class BaseDiscoveryService

java.lang.Object

org.apache.sling.discovery.base.commons.BaseDiscoveryService

All Implemented Interfaces:

DiscoveryService

Direct Known Subclasses:

OakDiscoveryService

public abstract class BaseDiscoveryService
extends java.lang.Object
implements DiscoveryService

Abstract base class for DiscoveryService implementations which uses the ClusterViewService plus Topology Connectors to calculate the current TopologyView

Constructor Summary

Constructors

Constructor and Description
BaseDiscoveryService()

Method Summary

Modifier and Type	Method and Description
protected abstract AnnouncementRegistry	getAnnouncementRegistry()
protected abstract ClusterViewService	getClusterViewService()
protected DefaultTopologyView	getOldView()
TopologyView	getTopology() Returns the topology that was last discovered by this service.
protected abstract void	handleIsolatedFromTopology()
protected void	setOldView(DefaultTopologyView view)

Methods inherited from class java.lang.Object

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

Constructor Detail

BaseDiscoveryService

public BaseDiscoveryService()

Method Detail

getClusterViewService

protected abstract ClusterViewService getClusterViewService()

getAnnouncementRegistry

protected abstract AnnouncementRegistry getAnnouncementRegistry()

handleIsolatedFromTopology

protected abstract void handleIsolatedFromTopology()

getOldView

protected DefaultTopologyView getOldView()

setOldView

protected void setOldView(DefaultTopologyView view)

getTopology

public TopologyView getTopology()

Description copied from interface: DiscoveryService

Returns the topology that was last discovered by this service.

If for some reason the service is currently not able to do topology discovery it will return the last valid topology marked with false in the call to . This is also true if the service has noticed a potential change in the topology and is in the process of settling the change in the topology (eg with peers, ie voting).

Note that this call is synchronized with TopologyEventListener.handleTopologyEvent() calls: ie if calls to TopologyEventListener.handleTopologyEvent() are currently ongoing, then the call to this method will block until all TopologyEventListeners have been called. Be careful not to cause deadlock situations.

Specified by:

getTopology in interface DiscoveryService

Returns:

the topology that was last discovered by this service. This will never be null (ie even if a change in the topology is ongoing at the moment or the cluster consists only of the local instance).

See Also:

DiscoveryService.getTopology()