[Startup Tracing] Separate TraceOptions and CategoryFilter

base/trace_event/trace_options.h

+// 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 BASE_TRACE_EVENT_TRACE_OPTIONS_H_
+#define BASE_TRACE_EVENT_TRACE_OPTIONS_H_
+
+#include <string>
+
+#include "base/base_export.h"
+
+namespace base {
+namespace trace_event {
+
+// Options determines how the trace buffer stores data.
+enum TraceRecordMode {
+  // Record until the trace buffer is full.
+  RECORD_UNTIL_FULL,
+
+  // Record until the user ends the trace. The trace buffer is a fixed size
+  // and we use it as a ring buffer during recording.
+  RECORD_CONTINUOUSLY,
+
+  // Echo to console. Events are discarded.
+  ECHO_TO_CONSOLE,
+
+  // Record until the trace buffer is full, but with a huge buffer size.
+  RECORD_AS_MUCH_AS_POSSIBLE
+};
+
+struct BASE_EXPORT TraceOptions {
+  TraceOptions()
+      : record_mode(RECORD_UNTIL_FULL),
+        enable_sampling(false),
+        enable_systrace(false),
+        enable_argument_filter(false) {}
+
+  explicit TraceOptions(TraceRecordMode record_mode)
+      : record_mode(record_mode),
+        enable_sampling(false),
+        enable_systrace(false),
+        enable_argument_filter(false) {}
+
+  // |options_string| is a comma-delimited list of trace options.
+  // Possible options are: "record-until-full", "record-continuously",
+  // "trace-to-console", "enable-sampling" and "enable-systrace".
+  // The first 3 options are trace recoding modes and hence
+  // mutually exclusive. If more than one trace recording modes appear in the
+  // options_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 |options_string| are applied on
+  // it.
+  // If |options_string| is invalid, the final state of trace_options is
+  // undefined.
+  //
+  // Example: trace_options.SetFromString("record-until-full")
+  // Example: trace_options.SetFromString(
+  //              "record-continuously, enable-sampling")
+  // Example: trace_options.SetFromString("record-until-full, trace-to-console")
+  // will set ECHO_TO_CONSOLE as the recording mode.
+  //
+  // Returns true on success.
+  bool SetFromString(const std::string& options_string);
+
+  std::string ToString() const;
+
+  TraceRecordMode record_mode;
+  bool enable_sampling;
+  bool enable_systrace;
+  bool enable_argument_filter;
+};
+
+}  // namespace trace_event
+}  // namespace base
+
+#endif  // BASE_TRACE_EVENT_TRACE_OPTIONS_H_