第9讲在camera app或java framework添加trace -凯发k8手机登录

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
实战:在camera app中添加trace
实战:在camera java framework中添加trace

资源	描述
在线课程
知识星球	星球名称：深入浅出android camera 星球id: 17296815
wechat	极客笔记圈

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();
}

在camera java framework中添加trace