org.apache.gobblin.broker

Interface ResourceEntry<T>

All Superinterfaces:

SharedResourceFactoryResponse<T>

public interface ResourceEntry<T>
extends SharedResourceFactoryResponse<T>

A SharedResourceFactoryResponse containing a instance of a resource.

Method Summary

Modifier and Type	Method and Description
T	getResource()
default T	getResourceIfValid() This method should guarantee that if all callers accessing the resource using this method then the object is returned atomically with respect to any validity state change.
boolean	isValid()
void	onInvalidate() This method will be called when the entry is invalidated.

Method Detail

getResource

T getResource()

Returns:

The instance of the resource.

isValid

boolean isValid()

Returns:

Whether this entry is valid. If the entry is invalid, it will be invalidated from the cache, causing a new call to the SharedResourceFactory.

onInvalidate

void onInvalidate()

This method will be called when the entry is invalidated. It may or may not close the contained resource depending on the semantics the SharedResourceFactory wishes to provide (e.g. whether already acquired objects should be closed). Note that for consistency, the broker runs this method synchronously before a new instance is created for the same key, blocking all requests for that key. As suck, this method should be reasonably fast.

getResourceIfValid

default T getResourceIfValid()

This method should guarantee that if all callers accessing the resource using this method then the object is returned atomically with respect to any validity state change. This is to avoid race conditions in cases where the state is changed when getting the resource. Some examples are resources that can only be used a certain number of times.

Returns:

null if the object is not valid, otherwise the valid object