This reverts commit d1eb971263f72deae84541d12b3bdd6d5972365a.
4.4 KiB
content-tracing
The content-trace
module is used to collect tracing data generated by the
underlying Chromium content module. 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.
var tracing = require('content-tracing');
tracing.startRecording('*', tracing.DEFAULT_OPTIONS, function() {
console.log('Tracing started');
setTimeout(function() {
tracing.stopRecording('', function(path) {
console.log('Tracing data recorded to ' + path);
});
}, 5000);
});
tracing.getCategories(callback)
callback
Function
Get a set of category groups. The category groups can change as new code paths are reached.
Once all child processes have acked to the getCategories
request, callback
is invoked with an array of category groups.
tracing.startRecording(categoryFilter, options, callback)
categoryFilter
Stringoptions
Integercallback
Function
Start recording on all processes.
Recording begins immediately locally, and asynchronously on child processes
as soon as they receive the EnableRecording request. Once all child processes
have acked to the startRecording
request, callback
will be called back.
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
options
controls what kind of tracing is enabled, it could be a OR-ed
combination of tracing.DEFAULT_OPTIONS
, tracing.ENABLE_SYSTRACE
,
tracing.ENABLE_SAMPLING
and tracing.RECORD_CONTINUOUSLY
.
tracing.stopRecording(resultFilePath, callback)
resultFilePath
Stringcallback
Function
Stop recording on all processes.
Child processes typically are caching trace data and only rarely flush and send trace data back to the main process. That is because it may be an expensive operation to send the trace data over IPC, and we would like to avoid much runtime overhead of tracing. So, to end tracing, we must asynchronously ask all child processes to flush any pending trace data.
Once all child processes have acked to the stopRecording
request, callback
will be called back 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.
tracing.startMonitoring(categoryFilter, options, callback)
categoryFilter
Stringoptions
Integercallback
Function
Start 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 acked to the startMonitoring
request,
callback
will be called back.
tracing.stopMonitoring(callback);
callback
Function
Stop monitoring on all processes.
Once all child processes have acked to the stopMonitoring
request, callback
is called back.
tracing.captureMonitoringSnapshot(resultFilePath, callback)
resultFilePath
Stringcallback
Function
Get the current monitoring traced data.
Child processes typically are caching trace data and only rarely flush and send trace data back to the main process. That is because it may be an expensive operation to send the trace data over IPC, and we would like to avoid unneeded runtime overhead of tracing. So, to end tracing, we must asynchronously ask all child processes to flush any pending trace data.
Once all child processes have acked to the captureMonitoringSnapshot
request,
the callback
will be invoked with a file that contains the traced data.
tracing.getTraceBufferUsage(callback)
callback
Function
Get the maximum across processes of trace buffer percent full state. When the
TraceBufferUsage value is determined, the callback
is called.
tracing.setWatchEvent(categoryName, eventName, callback)
categoryName
StringeventName
Stringcallback
Function
callback
will will be called every time the given event occurs on any
process.
tracing.cancelWatchEvent()
Cancel the watch event. If tracing is enabled, this may race with the watch event callback.