Android Camera性能分析 在Camera App或Java Framework添加trace

本讲是Android Camera性能分析专题的第9讲，我们介绍在Camera App或Java Framework添加trace，包括如下内容：

Java Trace类说明

android.os.Trace类	描述
beginSection(String sectionName)	在一个函数中打印Trace开始标记，会显示在某个线程中
endSection()	在一个函数中打印Trace结束标记，会显示在某个线程中
beginAsyncSection(String methodName, int cookie)	打印异步Trace开始标记，cookie用来区分相同methodName不同的异步Trace，会独立成一行Trace显示
endAsyncSection(String methodName, int cookie)	打印异步Trace结束标记，cookie用来区分相同methodName不同的异步Trace，会独立成一行Trace显示
setCounter(String counterName, long counterValue)	以给定计数器的值打印Trace
isEnabled()	判断是否Trace打开了，建议打印Trace前都判断下避免创建一些无用的临时对象

实战:在Camera App中添加Trace

public class GeekCamera2Trace {
    public static final String OPEN_CAMERA = "GC2_openCamera";
    public static final String CREATE_CAPTURE_SESSION = "GC2_createCaptureSession";
    public static final String FRAME_NUMBER = "GC2_FrameNumber";
    public static void beginAsyncSection(String methodName, int cookie) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q && Trace.isEnabled()) {
            Trace.beginAsyncSection(methodName, cookie);
        }
    }
 
    public static void endAsyncSection(String methodName, int cookie) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q && Trace.isEnabled()) {
            Trace.endAsyncSection(methodName, cookie);
        }
    }
 
    public static void beginSection(String sectionName) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q &&Trace.isEnabled()) {
            Trace.beginSection(sectionName);
        }
    }
 
    public static void endSection() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q &&Trace.isEnabled()) {
            Trace.endSection();
        }
    }
 
    public static void setCounter(String counterName, long counterValue) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q &&Trace.isEnabled()) {
            Trace.setCounter(counterName, counterValue);
        }
    }
}

实战:在Camera Java Framework中添加Trace

public void openCameraForUid(@NonNull String cameraId,
        @NonNull final CameraDevice.StateCallback callback, @NonNull Executor executor,
        int clientUid, int oomScoreOffset) throws CameraAccessException {
    Log.i(TAG, "v.deepinout.com openCameraForUid cameraId:" + cameraId);
    Trace.beginSection("GC2_FWK_openCameraForUid");
 
    if (cameraId == null) {
        throw new IllegalArgumentException("cameraId was null");
    } else if (callback == null) {
        throw new IllegalArgumentException("callback was null");
    }
    if (CameraManagerGlobal.sCameraServiceDisabled) {
        throw new IllegalArgumentException("No cameras available on device");
    }
 
    openCameraDeviceUserAsync(cameraId, callback, executor, clientUid, oomScoreOffset);
    Trace.endSection();
}