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Diffstat (limited to 'components/tracing/trace_config_file.h')
| -rw-r--r-- | components/tracing/trace_config_file.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/components/tracing/trace_config_file.h b/components/tracing/trace_config_file.h new file mode 100644 index 0000000..273f9f1 --- /dev/null +++ b/components/tracing/trace_config_file.h @@ -0,0 +1,94 @@ +// Copyright (c) 2015 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef COMPONENTS_TRACING_TRACE_CONFIG_FILE_H_ +#define COMPONENTS_TRACING_TRACE_CONFIG_FILE_H_ + +#include "base/files/file_path.h" +#include "base/macros.h" +#include "base/trace_event/trace_config.h" +#include "components/tracing/tracing_export.h" + +template <typename Type> struct DefaultSingletonTraits; + +namespace tracing { + +// TraceConfigFile is a singleton that contains the configurations of tracing. +// One can create a trace config file and use it to configure startup and/or +// shutdown tracing. +// +// The trace config file should be JSON formated. One example is: +// { +// "trace_config": { +// "record_mode": "record-until-full", +// "included_categories": ["cc", "skia"] +// }, +// "startup_duration": 5, +// "result_file": "chrometrace.log" +// } +// +// trace_config: The configuration of tracing. Please see the details in +// base/trace_event/trace_config.h. +// +// startup_duration: The duration for startup tracing in terms of seconds. +// Tracing will stop automatically after the duration. If this +// value is not specified, the duration is 0 and one needs +// to stop tracing by other ways, e.g., by DevTools, or get +// the result file after shutting the browser down. +// +// result_file: The file that contains the trace log. The default result +// file path is chrometrace.log. Chrome will dump the trace +// log to this file +// 1) after startup_duration if it is specified; +// 2) or after browser shutdown if startup duration is 0. +// One can also stop tracing and get the result by other ways, +// e.g., by DevTools. In that case, the trace log will not be +// saved to this file. +// Notice: This is not supported on Android. The result file +// path will be generated by tracing controller. +// +// The trace config file can be specified by the --trace-config-file flag on +// most platforms except on Android, e.g., --trace-config-file=path/to/file/. +// This flag should not be used with --trace-startup or --trace-shutdown. If +// those two flags are used, --trace-config-file flag will be ignored. If the +// --trace-config-file flag is used without the file path, Chrome will do +// startup tracing with 5 seconds' startup duration. +// +// On Android, Chrome does not read the --trace-config-file flag, because not +// all Chrome based browsers read customized flag, e.g., Android WebView. Chrome +// on Android reads from a fixed file location: +// /data/local/chrome-trace-config.json +// If this file exists, Chrome will start tracing according to the configuration +// specified in the file, otherwise, Chrome will not start tracing. +class TRACING_EXPORT TraceConfigFile { + public: + static TraceConfigFile* GetInstance(); + + bool IsEnabled() const; + base::trace_event::TraceConfig GetTraceConfig() const; + int GetStartupDuration() const; +#if !defined(OS_ANDROID) + base::FilePath GetResultFile() const; +#endif + + private: + // This allows constructor and destructor to be private and usable only + // by the Singleton class. + friend struct DefaultSingletonTraits<TraceConfigFile>; + TraceConfigFile(); + ~TraceConfigFile(); + + bool ParseTraceConfigFileContent(std::string content); + + bool is_enabled_; + base::trace_event::TraceConfig trace_config_; + int startup_duration_; + base::FilePath result_file_; + + DISALLOW_COPY_AND_ASSIGN(TraceConfigFile); +}; + +} // namespace tracing + +#endif // COMPONENTS_TRACING_TRACE_CONFIG_FILE_H_ |