Merge pull request #2418 from deepak1556/content_tracing_api_patch

tracing: fix api and docs

atom/browser/api/atom_api_content_tracing.cc

@@ -7,6 +7,7 @@
 
 #include "atom/common/native_mate_converters/file_path_converter.h"
 #include "base/bind.h"
+#include "base/files/file_util.h"
 #include "content/public/browser/tracing_controller.h"
 #include "native_mate/callback.h"
 #include "native_mate/dictionary.h"
@@ -46,6 +47,31 @@ struct Converter<base::trace_event::TraceOptions> {
 
 namespace {
 
+using CompletionCallback = base::Callback<void(const base::FilePath&)>;
+
+scoped_refptr<TracingController::TraceDataSink> GetTraceDataSink(
+    const base::FilePath& path, const CompletionCallback& callback) {
+  base::FilePath result_file_path = path;
+  if (result_file_path.empty() && !base::CreateTemporaryFile(&result_file_path))
+    LOG(ERROR) << "Creating temporary file failed";
+
+  return TracingController::CreateFileSink(result_file_path,
+                                           base::Bind(callback,
+                                                      result_file_path));
+}
+
+void StopRecording(const base::FilePath& path,
+                   const CompletionCallback& callback) {
+  TracingController::GetInstance()->DisableRecording(
+      GetTraceDataSink(path, callback));
+}
+
+void CaptureMonitoringSnapshot(const base::FilePath& path,
+                               const CompletionCallback& callback) {
+  TracingController::GetInstance()->CaptureMonitoringSnapshot(
+      GetTraceDataSink(path, callback));
+}
+
 void Initialize(v8::Local<v8::Object> exports, v8::Local<v8::Value> unused,
                 v8::Local<v8::Context> context, void* priv) {
   auto controller = base::Unretained(TracingController::GetInstance());
@@ -54,14 +80,12 @@ void Initialize(v8::Local<v8::Object> exports, v8::Local<v8::Value> unused,
       &TracingController::GetCategories, controller));
   dict.SetMethod("startRecording", base::Bind(
       &TracingController::EnableRecording, controller));
-  dict.SetMethod("stopRecording", base::Bind(
-      &TracingController::DisableRecording, controller, nullptr));
+  dict.SetMethod("stopRecording", &StopRecording);
   dict.SetMethod("startMonitoring", base::Bind(
       &TracingController::EnableMonitoring, controller));
   dict.SetMethod("stopMonitoring", base::Bind(
       &TracingController::DisableMonitoring, controller));
-  dict.SetMethod("captureMonitoringSnapshot", base::Bind(
-      &TracingController::CaptureMonitoringSnapshot, controller, nullptr));
+  dict.SetMethod("captureMonitoringSnapshot", &CaptureMonitoringSnapshot);
   dict.SetMethod("getTraceBufferUsage", base::Bind(
       &TracingController::GetTraceBufferUsage, controller));
   dict.SetMethod("setWatchEvent", base::Bind(

atom/browser/api/lib/content-tracing.coffee

@@ -1,7 +1 @@
 module.exports = process.atomBinding 'content_tracing'
-
-# Mirrored from content::TracingController::Options
-module.exports.DEFAULT_OPTIONS = 0
-module.exports.ENABLE_SYSTRACE = 1 << 0
-module.exports.ENABLE_SAMPLING = 1 << 1
-module.exports.RECORD_CONTINUOUSLY = 1 << 2

docs/api/content-tracing.md

@@ -28,10 +28,10 @@ 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)
+## tracing.startRecording(categoryFilter, traceOptions, callback)
 
 * `categoryFilter` String
-* `options` Integer
+* `traceOptions` String
 * `callback` Function
 
 Start recording on all processes.
@@ -51,9 +51,23 @@ Examples:
 * `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`.
+`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 recoding 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 mode is 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.
 
 ## tracing.stopRecording(resultFilePath, callback)
 
@@ -75,10 +89,10 @@ 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)
+## tracing.startMonitoring(categoryFilter, traceOptions, callback)
 
 * `categoryFilter` String
-* `options` Integer
+* `traceOptions` String
 * `callback` Function
 
 Start monitoring on all processes.