Package org.eclipse.core.runtime

Class PerformanceStats

  • public class PerformanceStats
extends Object
    PerformanceStats collects and aggregates timing data about events such as a builder running, an editor opening, etc. This data is collected for the purpose of performance analysis, and is not intended to be used as a generic event tracking and notification system.

    Each performance event can have an associated maximum acceptable duration that is specified in the platform debug options file (.options). Events that take longer than this maximum are logged as errors. Along with option file entries for each debug event, there are some global debug options for enabling or disabling performance event gathering and reporting. See the "org.eclipse.core.runtime/perf*" debug options in the .options file for the org.eclipse.core.runtime plugin for more details.

    A performance event can optionally have additional context information (getContext()). This information is only stored in the case of a performance failure, and can be used to provide further diagnostic information that can help track down the cause of the failure.

    Performance events and performance failures are batched up and periodically sent to interested performance event listeners.

    This class is not intended to be subclassed or instantiated by clients.

    Since:
    3.1

    • Field Detail

      • ENABLED

        public static final boolean ENABLED
        Constant indicating whether or not tracing is enabled

    • Method Detail

      • clear

        public static void clear()
        Discards all known performance event statistics.

      • getAllStats

        public static PerformanceStats[] getAllStats()
        Returns all performance event statistics.
        Returns:
        An array of known performance event statistics. The array will be empty if there are no recorded statistics.

      • getStats

        public static PerformanceStats getStats​(String eventName,
                                        Object blameObject)
        Returns the stats object corresponding to the given parameters. A stats object is created and added to the global list of events if it did not already exist.
        Parameters:
        eventName - A symbolic event name. This is usually the name of the debug option for this event. An example event name from the org.eclipse.core.resources plugin describing a build event might look like: "org.eclipse.core.resources/perf/building""
        blameObject - The blame for the event. This is typically the object whose code was running when the event occurred. If a blame object cannot be obtained, a String describing the event should be supplied

      • isEnabled

        public static boolean isEnabled​(String eventName)
        Returns whether monitoring of a given performance event is enabled.

        For frequent performance events, the result of this method call should be cached by the caller to minimize overhead when performance monitoring is turned off. It is not possible for enablement to change during the life of this invocation of the platform.

        Parameters:
        eventName - The name of the event to determine enablement for
        Returns:
        trueIf the performance event with the given name is enabled, and false otherwise.

      • printStats

        public static void printStats()
        Prints all statistics to the standard output.

      • printStats

        public static void printStats​(PrintWriter out)
        Writes all statistics using the provided writer
        Parameters:
        out - The writer to print stats to.

      • removeStats

        public static void removeStats​(String eventName,
                               Object blameObject)
        Removes statistics for a given event and blame
        Parameters:
        eventName - The name of the event to remove
        blameObject - The blame for the event to remove

      • addRun

        public void addRun​(long elapsed,
                   String contextName)
        Adds an occurrence of this event to the cumulative counters. This method can be used as an alternative to startRun and endRun for clients that want to track the context and execution time separately.
        Parameters:
        elapsed - The elapsed time of the new occurrence in milliseconds
        contextName - The context for the event to return, or null. The context optionally provides extra information about an event, such as the name of a project being built, or the input of an editor being opened.

      • endRun

        public void endRun()
        Stops timing the occurrence of this event that was started by the previous call to startRun. The event is automatically added to the cumulative counters for this event and listeners are notified.

        Note that this facility guards itself against runs that start but fail to stop, so it is not necessary to call this method from a finally block. Tracking performance of failure cases is generally not of interest.

        See Also:
        startRun()

      • getBlame

        public Object getBlame()
        Returns an object that can be used to figure out who caused the event, or a string describing the cause of the event.
        Returns:
        The blame for this event

      • getBlameString

        public String getBlameString()
        Returns a string describing the blame for this event.
        Returns:
        A string describing the blame.

      • getContext

        public String getContext()
        Returns the optional event context, such as the input of an editor, or the target project of a build event.
        Returns:
        The context, or null if there is none

      • getEvent

        public String getEvent()
        Returns the symbolic name of the event that occurred.
        Returns:
        The name of the event.

      • getRunCount

        public int getRunCount()
        Returns the total number of times this event has occurred.
        Returns:
        The number of occurrences of this event.

      • getRunningTime

        public long getRunningTime()
        Returns the total execution time in milliseconds for all occurrences of this event.
        Returns:
        The total running time in milliseconds.

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object

      • isFailure

        public boolean isFailure()
        Returns whether this performance event represents a performance failure.
        Returns:
        true if this is a performance failure, and false otherwise.

      • reset

        public void reset()
        Resets count and running time for this particular stats event.

      • startRun

        public void startRun()
        Starts timing an occurrence of this event. This is a convenience method, fully equivalent to startRun(null).

      • startRun

        public void startRun​(String contextName)
        Starts timing an occurrence of this event. The event should be stopped by a subsequent call to endRun.
        Parameters:
        contextName - The context for the event to return, or null. The context optionally provides extra information about an event, such as the name of a project being built, or the input of an editor being opened.
        See Also:
        endRun()

      • toString

        public String toString()
        For debugging purposes only.
        Overrides:
        toString in class Object