Performance

Performance 接口会给出某个页面的与时间相关的性能信息。

该类型对象可以通过调用只读属性 Window.performance 获得。

属性

Performance 接口不从别的类继承属性。

Performance.navigation 只读 Not available to workers

是一个 PerformanceNavigation 对象代表了页面浏览上下文的导航信息，比如获取资源时的重定向。

Performance.timing 只读 Not available to workers

是一个 PerformanceTiming 对象包含了与延迟相关的性能信息。

事件

Performance.onresourcetimingbufferfull

一个 EventTarget 回调方法，当 resourcetimingbufferfull 事件触发时被调用。

方法

Performance 接口没有从别的类继承来的方法.

Performance.clearMarks()

清除浏览器的performance缓存中已经存在的的标记

Performance.clearMeasures()

Removes the given measure from the browser's performance entry buffer.

Performance.clearResourceTimings()

Removes all performance entries with a entryType of "resource" from the browser's performance data buffer.

Performance.getEntries()

Returns a list of PerformanceEntry objects based on the given filter.

Performance.getEntriesByName()

Returns a list of PerformanceEntry objects based on the given name and entry type.

Performance.getEntriesByType()

Returns a list of PerformanceEntry objects of the given entry type.

Performance.mark()

Creates a timestamp in the browser's performance entry bufferwith the given name.

Performance.measure()

Creates a named timestamp in the browser's performance entry buffer between two specified marks (known as the start mark and end mark, respectively).

Performance.now()

返回一个 DOMHighResTimeStamp 类实例表示距离页面开始请求到现在相差的毫秒数（即 Date.now() - Performance.timing.navigationStart ）。

Performance.setResourceTimingBufferSize()

Sets the browser's resource timing buffer size to the specified number of "resource" type performance entry objects.

Performance.toJSON() Not available to workers

Is a jsonizer returning a json object representing the Performance object.

Specifications

Browser compatibility

[1] Member prefixed with webkit have been removed or deprecated.