Interface Performance

Provides access to performance-related information for the current page. It's part of the High Resolution Time API, but is enhanced by the Performance Timeline API, the Navigation Timing API, the User Timing API, and the Resource Timing API.

interface Performance {
    eventCounts: EventCounts;
    navigation: PerformanceNavigation;
    onresourcetimingbufferfull: null | ((this: Performance, ev: Event) => any);
    timeOrigin: number;
    timing: PerformanceTiming;
    addEventListener<K>(type: K, listener: ((this: Performance, ev: PerformanceEventMap[K]) => any), options?: boolean | AddEventListenerOptions): void;
    addEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | AddEventListenerOptions): void;
    clearMarks(markName?: string): void;
    clearMeasures(measureName?: string): void;
    clearResourceTimings(): void;
    dispatchEvent(event: Event): boolean;
    getEntries(): PerformanceEntryList;
    getEntriesByName(name: string, type?: string): PerformanceEntryList;
    getEntriesByType(type: string): PerformanceEntryList;
    mark(markName: string, markOptions?: PerformanceMarkOptions): PerformanceMark;
    measure(measureName: string, startOrMeasureOptions?: string | PerformanceMeasureOptions, endMark?: string): PerformanceMeasure;
    now(): number;
    removeEventListener<K>(type: K, listener: ((this: Performance, ev: PerformanceEventMap[K]) => any), options?: boolean | EventListenerOptions): void;
    removeEventListener(type: string, listener: EventListenerOrEventListenerObject, options?: boolean | EventListenerOptions): void;
    setResourceTimingBufferSize(maxSize: number): void;
    toJSON(): any;
}

Hierarchy

  • EventTarget
    • Performance

Properties

eventCounts navigation onresourcetimingbufferfull timeOrigin timing

Methods

addEventListener clearMarks clearMeasures clearResourceTimings dispatchEvent getEntries getEntriesByName getEntriesByType mark measure now removeEventListener setResourceTimingBufferSize toJSON

Properties

ReadonlyeventCounts

eventCounts: EventCounts

Readonlynavigation

navigation: PerformanceNavigation

Deprecated

onresourcetimingbufferfull

onresourcetimingbufferfull: null | ((this: Performance, ev: Event) => any)

ReadonlytimeOrigin

timeOrigin: number

Readonlytiming

timing: PerformanceTiming

Deprecated

Methods

addEventListener

  • addEventListener<K>(type, listener, options?): void

  • Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.

    The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.

    When set to true, options's capture prevents callback from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE. When false (or not present), callback will not be invoked when event's eventPhase attribute value is CAPTURING_PHASE. Either way, callback will be invoked if event's eventPhase attribute value is AT_TARGET.

    When set to true, options's passive indicates that the callback will not cancel the event by invoking preventDefault(). This is used to enable performance optimizations described in § 2.8 Observing event listeners.

    When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.

    If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.

    The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.

    Type Parameters

    • K extends "resourcetimingbufferfull"

    Parameters

    Returns void

  • addEventListener(type, listener, options?): void

  • Appends an event listener for events whose type attribute value is type. The callback argument sets the callback that will be invoked when the event is dispatched.

    The options argument sets listener-specific options. For compatibility this can be a boolean, in which case the method behaves exactly as if the value was specified as options's capture.

    When set to true, options's capture prevents callback from being invoked when the event's eventPhase attribute value is BUBBLING_PHASE. When false (or not present), callback will not be invoked when event's eventPhase attribute value is CAPTURING_PHASE. Either way, callback will be invoked if event's eventPhase attribute value is AT_TARGET.

    When set to true, options's passive indicates that the callback will not cancel the event by invoking preventDefault(). This is used to enable performance optimizations described in § 2.8 Observing event listeners.

    When set to true, options's once indicates that the callback will only be invoked once after which the event listener will be removed.

    If an AbortSignal is passed for options's signal, then the event listener will be removed when signal is aborted.

    The event listener is appended to target's event listener list and is not appended if it has the same type, callback, and capture.

    Parameters

    Returns void

clearMarks

  • clearMarks(markName?): void

  • Parameters

    • OptionalmarkName: string

    Returns void

clearMeasures

  • clearMeasures(measureName?): void

  • Parameters

    • OptionalmeasureName: string

    Returns void

clearResourceTimings

  • clearResourceTimings(): void

  • Returns void

dispatchEvent

  • dispatchEvent(event): boolean

  • Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.

    Parameters

    • event: Event

    Returns boolean

getEntries

getEntriesByName

getEntriesByType

mark

  • mark(markName, markOptions?): PerformanceMark

  • Parameters

    Returns PerformanceMark

measure

  • measure(measureName, startOrMeasureOptions?, endMark?): PerformanceMeasure

  • Parameters

    Returns PerformanceMeasure

now

  • now(): number

  • Returns number

removeEventListener

  • removeEventListener<K>(type, listener, options?): void

  • Removes the event listener in target's event listener list with the same type, callback, and options.

    Type Parameters

    • K extends "resourcetimingbufferfull"

    Parameters

    Returns void

  • removeEventListener(type, listener, options?): void

  • Removes the event listener in target's event listener list with the same type, callback, and options.

    Parameters

    Returns void

setResourceTimingBufferSize

  • setResourceTimingBufferSize(maxSize): void

  • Parameters

    • maxSize: number

    Returns void

toJSON

  • toJSON(): any

  • Returns any

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