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// Copyright 2014 The Flutter 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.
///
/// This is parsed from "traceEvents" data within [json] and sorted by
/// timestamp. Anything without a valid timestamp is put in the beginning.
///
/// This will be null if there are are no "traceEvents" in the [json].
final List<TimelineEvent>? events;
}
/// A single timeline event.
class TimelineEvent {
/// Creates a timeline event given JSON-encoded event data.
TimelineEvent(this.json)
: name = json['name'] as String?,
category = json['cat'] as String?,
phase = json['ph'] as String?,
processId = json['pid'] as int?,
threadId = json['tid'] as int?,
duration = json['dur'] != null
? Duration(microseconds: json['dur'] as int)
: null,
threadDuration = json['tdur'] != null
? Duration(microseconds: json['tdur'] as int)
: null,
timestampMicros = json['ts'] as int?,
threadTimestampMicros = json['tts'] as int?,
arguments = json['args'] as Map<String, dynamic>?;
/// 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'] as List<dynamic>?;
if (jsonEvents == null) {
return null;
}
final List<TimelineEvent> timelineEvents =
Iterable.castFrom<dynamic, Map<String, dynamic>>(jsonEvents)
.map<TimelineEvent>(
(Map<String, dynamic> eventJson) => TimelineEvent(eventJson))
.toList();
timelineEvents.sort((TimelineEvent e1, TimelineEvent e2) {
final int? ts1 = e1.timestampMicros;
final int? ts2 = e2.timestampMicros;
if (ts1 == null) {
if (ts2 == null) {
return 0;
} else {
return -1;
}
} else if (ts2 == null) {
return 1;
} else {
return ts1.compareTo(ts2);
}
});
return timelineEvents;
}