oshi.util.platform.windows

Class PerfDataUtil

java.lang.Object

oshi.util.platform.windows.PerfDataUtil

public class PerfDataUtil
extends Object

Helper class to centralize the boilerplate portions of PDH counter setup and allow applications to easily add, query, and remove counters.

Author:

widdis[at]gmail[dot]com

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	PerfDataUtil.PerfCounter

Field Summary

Fields

Modifier and Type	Field and Description
static PerfDataUtil	INSTANCE Instance to generate the PerfCounter class.

Method Summary

Modifier and Type	Method and Description
static boolean	addCounterToQuery(PerfDataUtil.PerfCounter counter) Begin monitoring a Performance Data counter
static PerfDataUtil.PerfCounter	createCounter(String object, String instance, String counter) Create a Performance Counter
static long	filetimeToUtcMs(long filetime, boolean local) Convert a long representing filetime (100-ns since 1601 epoch) to ms since 1970 epoch
static long	queryCounter(PerfDataUtil.PerfCounter counter) Query the raw counter value of a Performance Data counter.
static void	removeAllCounters() Stop monitoring all Performance Data counters and release their resources
static void	removeAllCounters(String queryKey) Stop monitoring Performance Data counters for a particular queryKey and release their resources
static boolean	removeCounterFromQuery(PerfDataUtil.PerfCounter counter) Stop monitoring a Performance Data counter
static long	updateQuery(PerfDataUtil.PerfCounter counter) Update a counter, and all other counters on that object
static long	updateQuery(String queryKey) Update all counters on an object

Methods inherited from class java.lang.Object

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

Field Detail

INSTANCE

public static final PerfDataUtil INSTANCE

Instance to generate the PerfCounter class.

Method Detail

createCounter

public static PerfDataUtil.PerfCounter createCounter(String object,
                                                     String instance,
                                                     String counter)

Create a Performance Counter

Parameters:

object - The object/path for the counter

instance - The instance of the counter, or null if no instance

counter - The counter name

Returns:

A PerfCounter object encapsulating the object, instance, and counter

addCounterToQuery

public static boolean addCounterToQuery(PerfDataUtil.PerfCounter counter)

Begin monitoring a Performance Data counter

Parameters:

counter - A PerfCounter object

Returns:

True if the counter was successfully added.

removeCounterFromQuery

public static boolean removeCounterFromQuery(PerfDataUtil.PerfCounter counter)

Stop monitoring a Performance Data counter

Parameters:

counter - A PerfCounter object

Returns:

True if the counter was successfully removed.

updateQuery

public static long updateQuery(PerfDataUtil.PerfCounter counter)

Update a counter, and all other counters on that object

Parameters:

counter - The counter whose object to update counters on

Returns:

The timestamp for the update of all the counters, in milliseconds since the epoch, or 0 if the update failed

updateQuery

public static long updateQuery(String queryKey)

Update all counters on an object

Parameters:

queryKey - The counter object to update counters on

Returns:

The timestamp for the update of all the counters, in milliseconds since the epoch, or 0 if the update failed

queryCounter

public static long queryCounter(PerfDataUtil.PerfCounter counter)

Query the raw counter value of a Performance Data counter. Further mathematical manipulation/conversion is left to the caller.

Parameters:

counter - The counter to query

Returns:

The raw value of the counter

removeAllCounters

public static void removeAllCounters(String queryKey)

Stop monitoring Performance Data counters for a particular queryKey and release their resources

Parameters:

queryKey - The counter object to remove counters from

removeAllCounters

public static void removeAllCounters()

Stop monitoring all Performance Data counters and release their resources

filetimeToUtcMs

public static long filetimeToUtcMs(long filetime,
                                   boolean local)

Convert a long representing filetime (100-ns since 1601 epoch) to ms since 1970 epoch

Parameters:

filetime - A 64-bit value equivalent to FILETIME

local - True if converting from a local filetime (PDH counter); false if already UTC (WMI PerfRawData classes)

Returns:

Equivalent milliseconds since the epoch