Collect tracing data from Chromium's content module for finding performance bottlenecks and slow operations.
Process: Main
This module does not include a web interface so you need to open chrome://tracing/
in a Chrome browser and load the generated file to view the result.
Note: You should not use this module until the ready
event of the app module is emitted.
const {app, contentTracing} = require('electron') app.on('ready', () => { const options = { categoryFilter: '*', traceOptions: 'record-until-full,enable-sampling' } contentTracing.startRecording(options, () => { console.log('Tracing started') setTimeout(() => { contentTracing.stopRecording('', (path) => { console.log('Tracing data recorded to ' + path) }) }, 5000) }) })
The contentTracing
module has the following methods:
contentTracing.getCategories(callback)
callback
Function
categories
String[]Get a set of category groups. The category groups can change as new code paths are reached.
Once all child processes have acknowledged the getCategories
request the callback
is invoked with an array of category groups.
contentTracing.startRecording(options, callback)
options
Object
categoryFilter
StringtraceOptions
Stringcallback
FunctionStart recording on all processes.
Recording begins immediately locally and asynchronously on child processes as soon as they receive the EnableRecording request. The callback
will be called once all child processes have acknowledged the startRecording
request.
categoryFilter
is a filter to control what category groups should be traced. A filter can have an optional -
prefix to exclude category groups that contain a matching category. Having both included and excluded category patterns in the same list is not supported.
Examples:
test_MyTest*
,test_MyTest*,test_OtherStuff
,"-excluded_category1,-excluded_category2
traceOptions
controls what kind of tracing is enabled, it is a comma-delimited list. Possible options are:
record-until-full
record-continuously
trace-to-console
enable-sampling
enable-systrace
The first 3 options are trace recording modes and hence mutually exclusive. If more than one trace recording modes appear in the traceOptions
string, the last one takes precedence. If none of the trace recording modes are specified, recording mode is record-until-full
.
The trace option will first be reset to the default option (record_mode
set to record-until-full
, enable_sampling
and enable_systrace
set to false
) before options parsed from traceOptions
are applied on it.
contentTracing.stopRecording(resultFilePath, callback)
resultFilePath
Stringcallback
Function
resultFilePath
StringStop recording on all processes.
Child processes typically cache trace data and only rarely flush and send trace data back to the main process. This helps to minimize the runtime overhead of tracing since sending trace data over IPC can be an expensive operation. So, to end tracing, we must asynchronously ask all child processes to flush any pending trace data.
Once all child processes have acknowledged the stopRecording
request, callback
will be called with a file that contains the traced data.
Trace data will be written into resultFilePath
if it is not empty or into a temporary file. The actual file path will be passed to callback
if it's not null
.
contentTracing.startMonitoring(options, callback)
options
Object
categoryFilter
StringtraceOptions
Stringcallback
FunctionStart monitoring on all processes.
Monitoring begins immediately locally and asynchronously on child processes as soon as they receive the startMonitoring
request.
Once all child processes have acknowledged the startMonitoring
request the callback
will be called.
contentTracing.stopMonitoring(callback)
callback
FunctionStop monitoring on all processes.
Once all child processes have acknowledged the stopMonitoring
request the callback
is called.
contentTracing.captureMonitoringSnapshot(resultFilePath, callback)
resultFilePath
Stringcallback
Function
resultFilePath
StringGet the current monitoring traced data.
Child processes typically cache trace data and only rarely flush and send trace data back to the main process. This is because it may be an expensive operation to send the trace data over IPC and we would like to avoid unneeded runtime overhead from tracing. So, to end tracing, we must asynchronously ask all child processes to flush any pending trace data.
Once all child processes have acknowledged the captureMonitoringSnapshot
request the callback
will be called with a file that contains the traced data.
contentTracing.getTraceBufferUsage(callback)
callback
Function
value
Numberpercentage
NumberGet the maximum usage across processes of trace buffer as a percentage of the full state. When the TraceBufferUsage value is determined the callback
is called.
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Licensed under the MIT license.
https://electronjs.org/docs/api/content-tracing