Performance extension type

The Performance interface provides access to performance-related information for the current page.

Performance entries are specific to each execution context. You can access performance information for code running in a window via Window.performance, and for code running in a worker via WorkerGlobalScope.performance.

API documentation sourced from MDN Web Docs.

on
Implemented types
Available extensions

Properties

eventCounts → EventCounts
The read-only performance.eventCounts property is an EventCounts map containing the number of events which have been dispatched per event type.
no setter
hashCode → int
The hash code for this object.
no setterinherited
The legacy Performance.navigation read-only property returns a PerformanceNavigation object representing the type of navigation that occurs in the given browsing context, such as the number of redirections needed to fetch the resource.
no setter
onresourcetimingbufferfull ↔ EventHandler?
getter/setter pair
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
timeOrigin → double
The timeOrigin read-only property of the Performance interface returns the high resolution timestamp that is used as the baseline for performance-related timestamps.
no setter
timing → PerformanceTiming
The legacy Performance.timing read-only property returns a PerformanceTiming object containing latency-related performance information.
no setter

Methods

addEventListener(String type, EventListener? callback, [JSAny options]) → void
The addEventListener() method of the EventTarget interface sets up a function that will be called whenever the specified event is delivered to the target.
inherited
clearMarks([String markName]) → void
The clearMarks() method removes all or specific PerformanceMark objects from the browser's performance timeline.
clearMeasures([String measureName]) → void
The clearMeasures() method removes all or specific PerformanceMeasure objects from the browser's performance timeline.
clearResourceTimings() → void
The clearResourceTimings() method removes all performance entries with an PerformanceEntry.entryType of "resource" from the browser's performance timeline and sets the size of the performance resource data buffer to zero.
dispatchEvent(Event event) → bool
The dispatchEvent() method of the EventTarget sends an Event to the object, (synchronously) invoking the affected event listeners in the appropriate order. The normal event processing rules (including the capturing and optional bubbling phase) also apply to events dispatched manually with dispatchEvent().
inherited
getEntries() → PerformanceEntryList
The getEntries() method returns an array of all PerformanceEntry objects currently present in the performance timeline.
getEntriesByName(String name, [String type]) → PerformanceEntryList
The getEntriesByName() method returns an array of PerformanceEntry objects currently present in the performance timeline with the given name and type.
getEntriesByType(String type) → PerformanceEntryList
The getEntriesByType() method returns an array of PerformanceEntry objects currently present in the performance timeline for a given type.
mark(String markName, [PerformanceMarkOptions markOptions]) → PerformanceMark
The mark() method creates a named PerformanceMark object representing a high resolution timestamp marker in the browser's performance timeline.
measure(String measureName, [JSAny startOrMeasureOptions, String endMark]) → PerformanceMeasure
The measure() method creates a named PerformanceMeasure object representing a time measurement between two marks in the browser's performance timeline.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
now() → double
The performance.now() method returns a high resolution timestamp in milliseconds. It represents the time elapsed since Performance.timeOrigin (the time when navigation has started in window contexts, or the time when the worker is run in Worker and ServiceWorker contexts).
removeEventListener(String type, EventListener? callback, [JSAny options]) → void
The removeEventListener() method of the EventTarget interface removes an event listener previously registered with EventTarget.addEventListener from the target. The event listener to be removed is identified using a combination of the event type, the event listener function itself, and various optional options that may affect the matching process; see Matching event listeners for removal.
inherited
setResourceTimingBufferSize(int maxSize) → void
The setResourceTimingBufferSize() method sets the desired size of the browser's resource timing buffer which stores the "resource" performance entries.
toJSON() → JSObject
The toJSON() method of the Performance interface is a ; it returns a JSON representation of the Performance object.
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited