Package org.apache.hadoop.fs.statistics.impl

Class IOStatisticsContextIntegration

java.lang.Object

org.apache.hadoop.fs.statistics.impl.IOStatisticsContextIntegration

public final class IOStatisticsContextIntegration
extends java.lang.Object

A Utility class for IOStatisticsContext, which helps in creating and getting the current active context. Static methods in this class allows to get the current context to start aggregating the IOStatistics. Static initializer is used to work out if the feature to collect thread-level IOStatistics is enabled or not and the corresponding implementation class is called for it. Weak Reference thread map to be used to keep track of different context's to avoid long-lived memory leakages as these references would be cleaned up at GC.

Field Summary

Fields

Modifier and Type	Field	Description
static java.util.concurrent.atomic.AtomicLong	INSTANCE_ID	ID for next instance to create.

Method Summary

Modifier and Type	Method	Description
static void	enableIOStatisticsContext()	A method to enable IOStatisticsContext to override if set otherwise in the configurations for tests.
static IOStatisticsContext	getCurrentIOStatisticsContext()	Get the current thread's IOStatisticsContext instance.
static IOStatisticsContext	getThreadSpecificIOStatisticsContext(long testThreadId)	Get thread ID specific IOStatistics values if statistics are enabled and the thread ID is in the map.
static boolean	isIOStatisticsThreadLevelEnabled()	Static probe to check if the thread-level IO statistics enabled.
static void	setThreadIOStatisticsContext(IOStatisticsContext statisticsContext)	Set the IOStatisticsContext for the current thread.

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE_ID

public static final java.util.concurrent.atomic.AtomicLong INSTANCE_ID

ID for next instance to create.

Method Detail

isIOStatisticsThreadLevelEnabled

public static boolean isIOStatisticsThreadLevelEnabled()

Static probe to check if the thread-level IO statistics enabled.

Returns:

if the thread-level IO statistics enabled.

getCurrentIOStatisticsContext

public static IOStatisticsContext getCurrentIOStatisticsContext()

Get the current thread's IOStatisticsContext instance. If no instance is present for this thread ID, create one using the factory.

Returns:

instance of IOStatisticsContext.

setThreadIOStatisticsContext

public static void setThreadIOStatisticsContext(IOStatisticsContext statisticsContext)

Set the IOStatisticsContext for the current thread.

Parameters:

statisticsContext - IOStatistics context instance for the current thread. If null, the context is reset.

getThreadSpecificIOStatisticsContext

@VisibleForTesting
public static IOStatisticsContext getThreadSpecificIOStatisticsContext(long testThreadId)

Get thread ID specific IOStatistics values if statistics are enabled and the thread ID is in the map.

Parameters:

testThreadId - thread ID.

Returns:

IOStatisticsContext if found in the map.

enableIOStatisticsContext

@VisibleForTesting
public static void enableIOStatisticsContext()

A method to enable IOStatisticsContext to override if set otherwise in the configurations for tests.