Commit ccd154f6 authored by Eric Seidel's avatar Eric Seidel

Merge pull request #738 from eseidelGoogle/profile_startup

Add script for profiling startup using flutter trace on Android
parents 7b518d95 5e70bd13
#!/usr/bin/env dart
// Copyright 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.
import 'dart:io';
import 'dart:async';
import 'dart:convert';
const int ITERATIONS = 3;
String runWithLoggingSync(List<String> cmd, {
bool checked: true,
String workingDirectory
}) {
ProcessResult results =
Process.runSync(cmd[0], cmd.getRange(1, cmd.length).toList(), workingDirectory: workingDirectory);
if (results.exitCode != 0) {
String errorDescription = 'Error code ${results.exitCode} '
'returned when attempting to run command: ${cmd.join(' ')}';
print(errorDescription);
if (results.stderr.length > 0)
print('Errors logged: ${results.stderr.trim()}');
if (checked)
throw errorDescription;
}
if (results.stdout.trim().isNotEmpty)
print(results.stdout.trim());
return results.stdout;
}
double timeToFirstFrame(trace) {
// TODO(eseidel): Sort! Events are not guarenteed to be in timestamp order.
List events = trace['traceEvents'];
int firstTimeStamp = events[0]['ts'].toInt();
var firstSwap = events.firstWhere((e) => e['name'] == 'NativeViewGLSurfaceEGL:RealSwapBuffers');
int swapStart = firstSwap['ts'].toInt();
int swapEnd = swapStart + firstSwap['dur'].toInt();
return (swapEnd - firstTimeStamp) / 1000; // microseconds to milliseconds.
}
Future<double> test(String tracesDir, String projectPath, int runNumber) async {
// If we used package:path we could grab the basename of project_path
// and include that in the trace_name.
String tracePath = "${tracesDir}/trace_$runNumber.json";
runWithLoggingSync([
'flutter',
'start',
'--trace-startup'
], workingDirectory: projectPath);
await new Future.delayed(const Duration(seconds: 2), () => "");
runWithLoggingSync([
'flutter',
'trace',
'--stop',
'--out=${tracePath}'
], workingDirectory: projectPath);
JsonDecoder decoder = new JsonDecoder();
String contents = await new File(tracePath).readAsString();
Map data = await decoder.convert(contents);
return timeToFirstFrame(data);
}
// package:statistics has slightly nicer ones of these.
double mean(List<double> times) {
return times.reduce((a,b) => a + b) / times.length;
}
double median(List<double> times) {
times.sort();
return times[times.length ~/ 2];
}
main(List<String> args) async {
// We could do much more sophisticated things if we used package:args.
if (args.length < 1) {
print("Usage: profile_startup.dart PROJECT_PATH\n");
print("PROJECT_PATH required.");
return 1;
}
String projectPath = args[0];
String traces_dir = '/tmp';
List<double> times = [];
print("$ITERATIONS runs using $projectPath:");
for (var x = 0; x < ITERATIONS; x++) {
int runNumber = x + 1;
double time = await test(traces_dir, projectPath, runNumber);
print(" ${runNumber.toString().padLeft(2)} $time");
times.add(time);
}
print("mean: ${mean(times)}");
print("median: ${median(times)}");
}
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