contentTracing

Collect tracing data from Chromium to find performance bottlenecks and slow operations.

进程：主进程

This module does not include a web interface. To view recorded traces, use trace viewer, available at chrome://tracing in Chrome.

注意：在应用程序模块的 ready 事件触发之前，您不应该使用此模块。

const { app, contentTracing } = require('electron')
app.whenReady().then(() => {
  (async () => {
    await contentTracing.startRecording({
      include_categories: ['*']
    })
    console.log('Tracing started')
    await new Promise(resolve => setTimeout(resolve, 5000))
    const path = await contentTracing.stopRecording()
    console.log('Tracing data recorded to ' + path)
  })()
})

方法

contentTracing模块包含以下方法：

contentTracing.getCategories()

Returns Promise<String[]> - resolves with an array of category groups once all child processes have acknowledged the getCategories request

Get a set of category groups. The category groups can change as new code paths are reached. See also the list of built-in tracing categories.

NOTE: Electron adds a non-default tracing category called "electron". This category can be used to capture Electron-specific tracing events.

contentTracing.startRecording(options)

• options (TraceConfig | TraceCategoriesAndOptions)

Returns Promise<void> - resolved once all child processes have acknowledged the startRecording request.

在所有进程上开始记录

一旦收到EnableRecording请求，记录立即在本地开始进行，并在子进程上异步执行。

If a recording is already running, the promise will be immediately resolved, as only one trace operation can be in progress at a time.

contentTracing.stopRecording([resultFilePath])

• resultFilePath String (optional)

Returns Promise<String> - resolves with a path to a file that contains the traced data once all child processes have acknowledged the stopRecording request

停止所有进程记录。

子进程通常缓存跟踪数据，并且很少清空和发送跟踪数据回到主进程。 这有助于最小化运行时间开销，因为通过IPC发送跟踪数据可能是一个开销巨大的操作。 So, to end tracing, Chromium asynchronously asks all child processes to flush any pending trace data.

Trace data will be written into resultFilePath. If resultFilePath is empty or not provided, trace data will be written to a temporary file, and the path will be returned in the promise.

contentTracing.getTraceBufferUsage()

Returns Promise<Object> - Resolves with an object containing the value and percentage of trace buffer maximum usage

• value Number
• percentage Number

Get the maximum usage across processes of trace buffer as a percentage of the full state.