org.das2.qds

Class ReferenceCache.ReferenceCacheEntry

java.lang.Object

org.das2.qds.ReferenceCache.ReferenceCacheEntry

Enclosing class:

ReferenceCache

public static class ReferenceCache.ReferenceCacheEntry
extends java.lang.Object

Keep track of the status of a load. This keeps track of the thread that is actually loading the data and it's

Method Summary

Modifier and Type	Method and Description
void	exception(java.lang.Exception ex) Notify the reference cache that the load resulted in an exception.
void	finished(QDataSet ds) hand the dataset resulting from the completed load off to the reference cache.
QDataSet	park(ProgressMonitor mon) park this thread until the other guy has finished loading.
boolean	shouldILoad(java.lang.Thread t) query this to see if the current thread should load the resource, or just park while the loading thread loads the resource.
java.lang.String	toString()
boolean	wasGarbageCollected() returns true if the entry was loaded, but now has been garbage collected.

Methods inherited from class java.lang.Object

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

Method Detail

shouldILoad

public boolean shouldILoad(java.lang.Thread t)

query this to see if the current thread should load the resource, or just park while the loading thread loads the resource.

Parameters:

t - the current thread (Thread.currentThread())

Returns:

true if the data should be loaded.

park

public QDataSet park(ProgressMonitor mon)
              throws java.lang.Exception

park this thread until the other guy has finished loading.

Parameters:

mon - monitor that will monitor the load status.

Returns:

the dataset

Throws:

java.lang.Exception - when the data cannot be read.

finished

public void finished(QDataSet ds)

hand the dataset resulting from the completed load off to the reference cache. Threads that are parked will continue. If the dataset is mutable, then a copy is made.

Parameters:

ds - the dataset resolved from the URI.

exception

public void exception(java.lang.Exception ex)

Notify the reference cache that the load resulted in an exception. Threads that are parked will continue

Parameters:

ex - the exception that occurred during the load.

wasGarbageCollected

public boolean wasGarbageCollected()

returns true if the entry was loaded, but now has been garbage collected.

Returns:

true if the reference was garbage collected and is no longer available.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object