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// Copyright 2016 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.
/// Timeline data recorded by the Flutter runtime.
class Timeline {
/// Creates a timeline given JSON-encoded timeline data.
///
/// [json] is in the `chrome://tracing` format. It can be saved to a file
/// and loaded in Chrome for visual inspection.
///
/// See https://docs.google.com/document/d/1CvAClvFfyA5R-PhYUmn5OOQtYMH4h6I0nSsKchNAySU/preview
factory Timeline.fromJson(Map<String, dynamic> json) {
return Timeline._(json, _parseEvents(json));
}
Timeline._(this.json, this.events);
/// The original timeline JSON.
final Map<String, dynamic> json;
/// List of all timeline events.
final List<TimelineEvent> events;
}
/// A single timeline event.
class TimelineEvent {
/// Creates a timeline event given JSON-encoded event data.
factory TimelineEvent(Map<String, dynamic> json) {
return TimelineEvent._(
json,
json['name'],
json['cat'],
json['ph'],
json['pid'],
json['tid'],
json['dur'] != null
? Duration(microseconds: json['dur'])
: null,
json['tdur'] != null
? Duration(microseconds: json['tdur'])
: null,
json['ts'],
json['tts'],
json['args'],
);
}
TimelineEvent._(
this.json,
this.name,
this.category,
this.phase,
this.processId,
this.threadId,
this.duration,
this.threadDuration,
this.timestampMicros,
this.threadTimestampMicros,
this.arguments,
);
/// The original event JSON.
final Map<String, dynamic> json;
/// The name of the event.
///
/// Corresponds to the "name" field in the JSON event.
final String name;
/// Event category. Events with different names may share the same category.
///
/// Corresponds to the "cat" field in the JSON event.
final String category;
/// For a given long lasting event, denotes the phase of the event, such as
/// "B" for "event began", and "E" for "event ended".
///
/// Corresponds to the "ph" field in the JSON event.
final String phase;
/// ID of process that emitted the event.
///
/// Corresponds to the "pid" field in the JSON event.
final int processId;
/// ID of thread that issues the event.
///
/// Corresponds to the "tid" field in the JSON event.
final int threadId;
/// The duration of the event.
///
/// Note, some events are reported with duration. Others are reported as a
/// pair of begin/end events.
///
/// Corresponds to the "dur" field in the JSON event.
final Duration duration;
/// The thread duration of the event.
///
/// Note, some events are reported with duration. Others are reported as a
/// pair of begin/end events.
///
/// Corresponds to the "tdur" field in the JSON event.
final Duration threadDuration;
/// Time passed since tracing was enabled, in microseconds.
///
/// Corresponds to the "ts" field in the JSON event.
final int timestampMicros;
/// Thread clock time, in microseconds.
///
/// Corresponds to the "tts" field in the JSON event.
final int threadTimestampMicros;
/// Arbitrary data attached to the event.
///
/// Corresponds to the "args" field in the JSON event.
final Map<String, dynamic> arguments;
}
List<TimelineEvent> _parseEvents(Map<String, dynamic> json) {
final List<dynamic> jsonEvents = json['traceEvents'];
if (jsonEvents == null)
return null;
// TODO(vegorov): use instance method version of castFrom when it is available.
return Iterable.castFrom<dynamic, Map<String, dynamic>>(jsonEvents)
.map<TimelineEvent>((Map<String, dynamic> eventJson) => TimelineEvent(eventJson))
.toList();
}