com.mapr.ojai.store.impl

Class SharedDrillSession

java.lang.Object

com.mapr.ojai.store.impl.SharedDrillSession

All Implemented Interfaces:

java.lang.AutoCloseable

public class SharedDrillSession
extends java.lang.Object
implements java.lang.AutoCloseable

Provides a holder for a Drill session that needs to be shared between multiple objects. This can happen when we need to execute a series of commands to the same session because session options have been set, and we want to execute in the environment that results. This holder can be used by document pipeline processing elements to share the drill session among themselves. Because of the use of reference counting, the class is intolerant of extra close() calls -- there must be exactly as many calls to close() as there were addRef() calls.

Constructor Summary

Constructors

Constructor and Description
SharedDrillSession(OjaiConnection ojaiConnection, java.lang.String clusterName)

Method Summary

Modifier and Type	Method and Description
void	addRef() Add a reference to this shared session.
void	close()
java.lang.String	getClusterName()
org.apache.drill.exec.rpc.user.clusterclient.DrillSession	getSession() Get the shared Drill session.

Methods inherited from class java.lang.Object

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

Constructor Detail

SharedDrillSession

public SharedDrillSession(OjaiConnection ojaiConnection,
                          java.lang.String clusterName)

Method Detail

addRef

public void addRef()

Add a reference to this shared session. Note that because of the use of reference counting to manage the lifetime of the Drill session, there must be exactly as many close() calls as there are addRef() calls.

getSession

public org.apache.drill.exec.rpc.user.clusterclient.DrillSession getSession()

Get the shared Drill session. The Drill session is created lazily, so the first call to this may take longer. Once created, the same drill session will be returned to all future callers. Note that this requires that the reference count be greater than zero.

Returns:

the drill session

close

public void close()

Specified by:

close in interface java.lang.AutoCloseable

getClusterName

public java.lang.String getClusterName()