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AndroidDevMetrics

字数统计: 930阅读时长: 4 min
2019/12/13 Share

AndroidDevMetrics

项目地址 https://github.com/apm29/AndroidDevMetrics

  • Usage

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     public class ExampleApplication extends Application {

    @Override
    public void onCreate() {
    super.onCreate();
    //Use it only in debug builds
    if (BuildConfig.DEBUG) {
    AndroidDevMetrics.initWith(this);
    }
    }
    }

    Activity生命周期方法计时的原理

  • AndroidDevMetrics.java

1.AndroidDevMetrics实例创建,通过Builder模式设置参数
可配置的参数:

  • dagger2WarningLevel1/2/3 三个等级设置 默认是30/50/100ms
  • enableAcitivtyMetrics = true;//是否记录Activity生命周期耗时
  • enableDagger2Metrics = true;//dagger注入耗时
  • showNotification = true;//在通知栏显示
  • autoCancelNotification = false;//是否可以点击后取消
  • intervalMillis = FRAME_DROPS_DEFAULT_INTERVAL_MS;//帧率分析间隔
  • maxFpsForFrameDrop = FRAME_DROPS_FPS_LIMIT;//最大掉帧限制
  • List interceptors;//UI拦截器

2.开始分析的主入口,AndroidDevMetrics实例的方法setupMetrics()

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private void setupMetrics() {
Dagger2GraphAnalyzer.setEnabled(enableDagger2Metrics);
InitManager.getInstance().initializedMetrics.clear();

ActivityLifecycleAnalyzer.setEnabled(true);
if (enableAcitivtyMetrics) {
MethodsTracingManager.getInstance().init(context);
ActivityLaunchMetrics activityLaunchMetrics = ActivityLaunchMetrics.getInstance();
((Application) context.getApplicationContext()).registerActivityLifecycleCallbacks(activityLaunchMetrics);
ChoreographerMetrics.getInstance().setMaxFpsForFrameDrop(maxFpsForFrameDrop);
ChoreographerMetrics.getInstance().setIntervalMillis(intervalMillis);
ChoreographerMetrics.getInstance().start();
}

if (showNotification) {
showNotification();
}
}
  • Dagger2GraphAnalyzer.setEnabled(enableDagger2Metrics);Dagger分析器的,一个带@Aspect注解的类,这个类里有许多@Pointcut @Around 修饰的方法,先略过,AOP相关的可以看看Android基于AOP的非侵入式监控之——AspectJ实战

  • InitManager.getInstance().initializedMetrics.clear();
    InitManager单例维护了几个LinkedHashMap对象和一个Set

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public final Set<OnMetricsDataListener> dataListeners = new HashSet<>();

public final LinkedHashMap<String, InitMetric> initializedMetrics = new LinkedHashMap<>();
public final LinkedHashMap<String, Integer> initCounter = new LinkedHashMap<>();

initializedMetrics应该是比较重要的,其中InitMetric这个类在许多地方都有涉及,类中成员的意义应该很明显了,看命名

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public Class<?> cls; //实例类class
public long initTimeMillis = 0;//初始化时间
public int instanceNo = 0;//实例个数
public String threadName = "";//线程名称?
public Set<InitMetric> args = new HashSet<>(); //初始化这个类需要的其他类的集合? 大概
public StackTraceElement[] traceElements;//堆栈记录

InitManager一上来先把initializedMetrics清空了.

  • 然后是ActivityLifecycleAnalyzer.setEnabled(true);应该和Dagger的分析器一样,是一个带@Aspect注解的类,有许多@Pointcut注解,
    其实是AspectJ的方式对onCreate/onStart/onResume三个生命周期方法进行监听,我们来看看监听的过程(在一个@Around注解的方法中,熟悉AOP的应该都晓得)

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    @Around("onCreateMethod() || onStartMethod() || onResumeMethod()")
    public Object logAndExecute(ProceedingJoinPoint joinPoint) throws Throwable {
    if (!enabled) return joinPoint.proceed();

    MethodSignature signature = (MethodSignature) joinPoint.getSignature();
    String methodName = signature.getMethod().getName();

    final Object result;
    if (METHOD_ON_RESUME.equals(methodName)) {
    ActivityLifecycleMetrics.getInstance().logPreOnResume((Activity) joinPoint.getTarget());
    result = executeWithTracingIfEnabled(joinPoint, methodName);
    ActivityLifecycleMetrics.getInstance().logPostOnResume((Activity) joinPoint.getTarget());
    } else if (METHOD_ON_START.equals(methodName)) {
    ActivityLifecycleMetrics.getInstance().logPreOnStart((Activity) joinPoint.getTarget());
    result = executeWithTracingIfEnabled(joinPoint, methodName);
    ActivityLifecycleMetrics.getInstance().logPostOnStart((Activity) joinPoint.getTarget());
    } else if (METHOD_ON_CREATE.equals(methodName)) {
    ActivityLifecycleMetrics.getInstance().logPreOnCreate((Activity) joinPoint.getTarget());
    result = executeWithTracingIfEnabled(joinPoint, methodName);
    ActivityLifecycleMetrics.getInstance().logPostOnCreate((Activity) joinPoint.getTarget());
    } else {
    result = null;
    }

    return result;
    }

    在启用监听的情况下首先

    • 获取方法的签名来区分是OnResume还是其他什么的
    • 获取了ActivityLifecycleMetrics实例在onResume执行前后分别调用logOreXXX 和 logPostXXX方法,很明显是打log用的
    • ActivityLifecycleMetrics自己维护了一个LinkedhashMap存放已经记录过得ActivityMetric对象,而ActivityMetric对象保存了一个Activity的 1. 状态 2. 各个生命周期耗时 3.是否实现了各个生命周期方法 4.各个状态的timeMillis,logPreXXX logPostXXX方法会把对应的ActivityMetric对象的状态进行对应的改变
  • MethodTrackingManager,应该是追踪Activity中具体方法的一个管理类,有两个Set集合保存ScheduledMethods 和 TrackedMethod ,setupMetrics里只做了一些初始化工作

  • ActivityLaunchMetrics,获取到Application之后为之注册了一个ActivityLifecycle监听,这个ActivityLaunchMetrics里面也在对应的生命周期里调用了ActivityLifecycleMetrics实例的logPostXXX方法,也就是说postXXX在 ActivityLaunchMetrics和ActivityLifecycleAnalyzer都被调用了一次

  • ChoreographerMetrics,应该是帧率帧数统计的管理类,使用Choreographer来统计的帧数这些,可以看看Choreographer的官方文档,了解下原理

CATALOG
  1. 1. AndroidDevMetrics
    1. 1.1. Activity生命周期方法计时的原理