Package org.apache.hadoop.ozone.container.common.utils

Class ReferenceCountedDB

java.lang.Object

org.apache.hadoop.ozone.container.common.interfaces.DBHandle

org.apache.hadoop.ozone.container.common.utils.ReferenceCountedDB

All Implemented Interfaces:

AutoCloseable, org.apache.ratis.util.UncheckedAutoCloseable

public class ReferenceCountedDB
extends DBHandle

Class to implement reference counting over instances handed by Container Cache. Enable DEBUG log below will enable us quickly locate the leaked reference from caller stack. When JDK9 StackWalker is available, we can switch to StackWalker instead of new Exception().printStackTrace().

Constructor Summary

Constructors

Constructor	Description
ReferenceCountedDB(DatanodeStore store, String containerDBPath)

Method Summary

Modifier and Type	Method	Description
boolean	cleanup()
void	close()
void	decrementReference()
long	getReferenceCount()
void	incrementReference()
boolean	isClosed()	Returns if the underlying DB is closed.

Methods inherited from class org.apache.hadoop.ozone.container.common.interfaces.DBHandle

getContainerDBPath, getStore

Methods inherited from class java.lang.Object

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

Constructor Details

ReferenceCountedDB

public ReferenceCountedDB(DatanodeStore store,
 String containerDBPath)

Method Details

getReferenceCount

public long getReferenceCount()

incrementReference

public void incrementReference()

decrementReference

public void decrementReference()

cleanup

public boolean cleanup()

Overrides:

cleanup in class DBHandle

close

public void close()

isClosed

public boolean isClosed()

Returns if the underlying DB is closed. This call is threadsafe.

Returns:

true if the DB is closed.