FrameWork内核解析之布局加载与资源系统（三）

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本篇文章将继续从以下两个内容来介绍布局加载与资源系统:

• [ LayoutManager]
• [ Resources 和 AssetManager]

一、LayoutManager

流程

继承RecyclerView.LayoutManager
重写onLayoutChildren来添加子View
重写scrollVerticallyBy来实现竖向滚动
继承RecyclerView.LayoutManager
就一个抽象方法,重写就行了

public class CustomLayoutManager extends RecyclerView.LayoutManager {
    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);
    }
}

onLayoutChildren

相当于ViewGroup的 onLayout.一开始的界面构建就是这个入口

1 在RecyclerView初始化时，会被调用两次。
2 在调用adapter.notifyDataSetChanged()时，会被调用。
3 在调用setAdapter替换Adapter时,会被调用。
4 在RecyclerView执行动画时，它也会被调用。

onLayoutChildren中的流程

报废当前的View
获取对应位置的子view
添加进RecyclerView
测量子View的宽高
根据测量的宽高,给他们排列好位置
注意,这一版本是没考虑缓存,全一股脑添加进RecyclerView的,目的是熟悉代码为后面铺垫
其中的函数

detachAndScrapAttachedViews : 是将当前Recycler中的view全部移除并放到报废缓存里,之后优先重用缓存里的view
getDecoratedMeasuredWidth/getDecoratedMeasuredHeight 获取宽高,这个是加上了DecorateView
的,现在没有 RecyclerView.addItemDecoration();直接理解为宽高就行
layoutDecorated就是用来个子View排位置的
actualHeight记录了目前的高度,为了实现LinearLayoutManager的垂直排序来的
然后看看具体代码吧

@Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() == 0){
            detachAndScrapAttachedViews(recycler);
            return;
        }
        //state.isPreLayout()是支持动画的
        if (getItemCount() == 0 && state.isPreLayout()){
            return;
        }

        detachAndScrapAttachedViews(recycler);

        actualHeight = 0;
        for (int i = 0 ;i < getItemCount() ; i++){
            View scrap = recycler.getViewForPosition(i);
            addView(scrap);
            measureChildWithMargins(scrap,0,0);
            int width = getDecoratedMeasuredWidth(scrap);
            int height = getDecoratedMeasuredHeight(scrap);
            layoutDecorated(scrap,0,actualHeight,width,actualHeight+height);
            actualHeight+=height;
        }
    }

测试的Activity

public class LayoutManagerActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_layout_manager);
        CustomLayoutManager customLayoutManager = new CustomLayoutManager();
        RecyclerView rv = findViewById(R.id.rv);
        rv.setLayoutManager(customLayoutManager);
        rv.setAdapter(new RecyclerView.Adapter<VH>() {
            @NonNull
            @Override
            public VH onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
                View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_custom,viewGroup,false);
                Log.d("LayoutManagerActivity","onCreateViewHolder " + i);
                return new VH(view);
            }

            @Override
            public void onBindViewHolder(@NonNull VH viewHolder, int i) {
                viewHolder.tv.setText(i+"");
                if (i%2 == 0){
                    viewHolder.tv.setBackgroundColor(Color.RED);
                }else {
                    viewHolder.tv.setBackgroundColor(Color.BLUE);
                }
                Log.d("LayoutManagerActivity","onBindViewHolder " + i);
            }

            @Override
            public int getItemCount() {
                return 20;
            }
        });
    }

    private static class VH extends RecyclerView.ViewHolder{

        TextView tv ;
        public VH(@NonNull View itemView) {
            super(itemView);
            tv = itemView.findViewById(R.id.tv);
        }
    }
}

就可以看到布局排列好了.但是

onCreateViewHolder调用了20次,onBindViewHolder也调用了20.不能滑动
滑动
canScrollVertically返回true就是可以垂直滑动
scrollVerticallyBy是滑动具体的逻辑
scrollVerticallyBy的参数要说明下

参数:
dy : 是当前滑动的距离,界面向下滚动的时候,dy为正,向上滚动的时候dy为负
返回的值: 如果Math.abs(返回值)小于dy,说明到达边界了,这里简单的处理下,如果到达边界了直接返回0

逻辑
通过totalScrollY来记录已经滑动的总距离
向下滚动的时候,如果总距离超过了子view的总高度-屏幕高度,说明到达下边界了
向上滚动的时候,如果总距离小于等于0,就是到达了上边界
其他就是正常情况了,使用offsetChildrenVertical来滚动界面
具体如下

@Override
    public boolean canScrollVertically() {
        return true;
    }


    @Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {
        //界面向下滚动的时候,dy为正,向上滚动的时候dy为负

        //向下滚动的时候,最下面的值不能超过总值,
        //向上滚动的时候,最上面的值不能小于0
        int willScrollTo = totalScrollY + dy;
        Log.d(TAG,"scrollVerticallyBy " + dy + " totalScrollY " + totalScrollY);
        if (willScrollTo >= actualHeight-getHeight()){
            offsetChildrenVertical(-1*(actualHeight - getHeight() - totalScrollY));
            totalScrollY = actualHeight- getHeight();
            return 0;
        }
        if (willScrollTo <= 0){
            offsetChildrenVertical(totalScrollY);
            totalScrollY = 0;
            return 0;
        }
        offsetChildrenVertical(dy*-1);
        totalScrollY +=dy;

        return dy;
    }

这样就完成了简陋版的LinearLayoutManager.完整代码

/**
 * 只有填充,滑动,没有回收
 */
public class CustomLayoutManager extends RecyclerView.LayoutManager {
    private final String TAG = "feifeifei";

    private int actualHeight = 0;
    private int totalScrollY = 0;
    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);
    }

    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        if (getItemCount() == 0){
            detachAndScrapAttachedViews(recycler);
            return;
        }
        //state.isPreLayout()是支持动画的
        if (getItemCount() == 0 && state.isPreLayout()){
            return;
        }

        detachAndScrapAttachedViews(recycler);

        actualHeight = 0;
        for (int i = 0 ;i < getItemCount() ; i++){
            View scrap = recycler.getViewForPosition(i);
            addView(scrap);
            measureChildWithMargins(scrap,0,0);
            int width = getDecoratedMeasuredWidth(scrap);
            int height = getDecoratedMeasuredHeight(scrap);
            layoutDecorated(scrap,0,actualHeight,width,actualHeight+height);
            actualHeight+=height;
        }
    }

    @Override
    public boolean canScrollVertically() {
        return true;
    }


    @Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {
        //界面向下滚动的时候,dy为正,向上滚动的时候dy为负

        //向下滚动的时候,最下面的值不能超过总值,
        //向上滚动的时候,最上面的值不能小于0
        int willScrollTo = totalScrollY + dy;
        Log.d(TAG,"scrollVerticallyBy " + dy + " totalScrollY " + totalScrollY);
        if (willScrollTo >= actualHeight-getHeight()){
            offsetChildrenVertical(-1*(actualHeight - getHeight() - totalScrollY));
            totalScrollY = actualHeight- getHeight();
            return 0;
        }
        if (willScrollTo <= 0){
            offsetChildrenVertical(totalScrollY);
            totalScrollY = 0;
            return 0;
        }
        offsetChildrenVertical(dy*-1);
        totalScrollY +=dy;

        return dy;
    }
}

加入回收功能

其实就是基于上边的简陋版本进行扩展

onLayoutChildren的时候不添加全部view,只添加可视范围内的View
滑动的时候要更复杂一点
如果向下滚动,先往RecyclerView下面添加即将展示的View
如果往上滚动,就往RecyclerView上面添加即将展示的View
添加完View后就调用offsetChildrenVertical进行滚动
完了后检查是否有子View离开了可视界面,如果不可见了,就是用removeAndRecycleView来移除掉
onLayoutChildren
与之前不同的就是最后几句,如果超过RecyclerView的高度了,就不Add了

 @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        Log.d(TAG,"onLayoutChildren ");
        if (getItemCount() == 0){
            detachAndScrapAttachedViews(recycler);
            return;
        }
        //state.isPreLayout()是支持动画的
        if (getItemCount() == 0 && state.isPreLayout()){
            return;
        }
        //将当前Recycler中的view全部移除并放到报废缓存里,之后优先重用缓存里的view
        detachAndScrapAttachedViews(recycler);

        int actualHeight = 0;
        for (int i = 0 ;i < getItemCount() ; i++){
            View scrap = recycler.getViewForPosition(i);
            addView(scrap);
            measureChildWithMargins(scrap,0,0);
            int width = getDecoratedMeasuredWidth(scrap);
            int height = getDecoratedMeasuredHeight(scrap);
            layoutDecorated(scrap,0,actualHeight,width,actualHeight+height);
            actualHeight+=height;
            //超出界面的就不画了,也不add了
            if (actualHeight > getHeight()){
                break;
            }
        }
    }

scrollVerticallyBy
之前说了,分为填充,滚动,回收

@Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {
        Log.d("feifeifei","getChildCount() " + getChildCount() + " recycler.getScrapList().size() " + recycler.getScrapList().size());

        //界面向下滚动的时候,dy为正,向上滚动的时候dy为负

        //向下滚动的时候,最下面的值不能超过总值,
        //向上滚动的时候,最上面的值不能小于0
   
        //填充
        fill(dy,recycler,state);
        //滚动
        offsetChildrenVertical(dy*-1);

        //回收已经离开界面的
        recycleOut(dy,recycler,state);


        return dy;
    }

填充

例如向下滚动

通过getChildAt获取最后一个View
再通过getPosition获取这个View的Adapter中的位置,最后一个了,就不要继续填充了,因为没有了,如果有下一个,就继续
这里还没有滑动,但是即将滑动的距离dy传进来了,如果最后一个View滑动dy后小于RecyclerView的高度了说明最后一个View已经全部出现在界面上了,之后就是空白了,需要添加新的子View
那就做获取,测量,添加操作
向上滚动是一样的逻辑

private void fill(int dy, RecyclerView.Recycler recycler, RecyclerView.State state){
        //向下滚动
        if (dy > 0){
            //先在底部填充
            View  lastView = getChildAt(getChildCount() -1);
            int lastPos = getPosition(lastView);
            if (lastPos == getChildCount()-1){
                return;
            }
            Log.d("feifeifei","lastView top" + lastView.getTop() + " bottom " + lastView.getBottom());
            if (lastView.getBottom() -  dy < getHeight()){
                View scrap = recycler.getViewForPosition(lastPos+1);
                addView(scrap);
                measureChildWithMargins(scrap,0,0);
                int width = getDecoratedMeasuredWidth(scrap);
                int height = getDecoratedMeasuredHeight(scrap);
                layoutDecorated(scrap,0,lastView.getBottom(),width,lastView.getBottom()+height);
            }
        }else {
            //向上滚动
            //现在顶部填充
            View  firstView = getChildAt(0);
            Log.d("feifeifei","firstView top" + firstView.getTop() + " bottom " + firstView.getBottom());
            int layoutPostion = getPosition(firstView);
            if (layoutPostion == 0){
                return;
            }
            if (firstView.getTop() >= 0 ){
                View scrap = recycler.getViewForPosition(layoutPostion -1);
                addView(scrap,0);
                measureChildWithMargins(scrap,0,0);
                int width = getDecoratedMeasuredWidth(scrap);
                int height = getDecoratedMeasuredHeight(scrap);
                layoutDecorated(scrap,0,firstView.getTop() - height,width,firstView.getTop());
            }
        }
    }

滚动

滚动就是直接用offsetChildrenVertical(dy*-1);但是需要和简陋版一样,需要搞定边界问题
例如: 到达上边界后,滑动的距离不是dy,而是第一个View还剩下多少距离可以滑动,代码如下

        int canScroll = dy;
        if (dy>0){
            View  lastView = getChildAt(getChildCount() -1);
            int lastPos = getPosition(lastView);
            if (lastPos >= getItemCount()-1){
                if (lastView.getBottom() - dy < getHeight()){
                    canScroll = lastView.getBottom() - getHeight();
                    offsetChildrenVertical(canScroll*-1);
                    return 0;
                }
            }
        }else {
            View  firView = getChildAt(0);
            int firstPos = getPosition(firView);
            if (firstPos <= 0){
                if (firView.getTop() - dy >= 0){
                    canScroll = firView.getTop();
                    offsetChildrenVertical(canScroll*-1);
                    return 0;
                }
            }
        }

回收

通过getChildCount() 获取当前所有的子View
例如向上滚动,name就回收最下面的,最下面的View的top滑动后超出了RecyclerView的高度,说明这个View全部在界面外了,可以回收了,使用removeAndRecycleView移除并回收
向下滚动就判断顶部的Bottom是否小于0

    private void recycleOut(int dy, RecyclerView.Recycler recycler, RecyclerView.State state){
        for (int i = 0 ; i <getChildCount() ;i++){
            View view = getChildAt(i);
            Log.d("feifeifei","recycleOut position "+ i + " top " + view.getTop() + " bottom " + view.getBottom());
            if (dy >0){
                if (view.getBottom()-dy <0){
                    Log.d("feifeifei","recycleOut " + i);
                    removeAndRecycleView(view,recycler);
                }
            }else {
                if (view.getTop()-dy > getHeight()){
                    Log.d("feifeifei","recycleOut " + i);
                    removeAndRecycleView(view,recycler);
                }
            }
        }
    }

这样带回收的LayoutManager也完成了,全部代码如下

/**
 * 填充,滑动,回收
 */
public class CustomLayoutManager2 extends RecyclerView.LayoutManager {
    private final String TAG = CustomLayoutManager2.class.getSimpleName();


    @Override
    public RecyclerView.LayoutParams generateDefaultLayoutParams() {
        return new RecyclerView.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,ViewGroup.LayoutParams.WRAP_CONTENT);
    }

//    1 在RecyclerView初始化时，会被调用两次。
//    2 在调用adapter.notifyDataSetChanged()时，会被调用。
//    3 在调用setAdapter替换Adapter时,会被调用。
//    4 在RecyclerView执行动画时，它也会被调用。
    @Override
    public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
        Log.d(TAG,"onLayoutChildren ");
        if (getItemCount() == 0){
            detachAndScrapAttachedViews(recycler);
            return;
        }
        //state.isPreLayout()是支持动画的
        if (getItemCount() == 0 && state.isPreLayout()){
            return;
        }
        //将当前Recycler中的view全部移除并放到报废缓存里,之后优先重用缓存里的view
        detachAndScrapAttachedViews(recycler);

        int actualHeight = 0;
        for (int i = 0 ;i < getItemCount() ; i++){
            View scrap = recycler.getViewForPosition(i);
            addView(scrap);
            measureChildWithMargins(scrap,0,0);
            int width = getDecoratedMeasuredWidth(scrap);
            int height = getDecoratedMeasuredHeight(scrap);
            layoutDecorated(scrap,0,actualHeight,width,actualHeight+height);
            actualHeight+=height;
            //超出界面的就不画了,也不add了
            if (actualHeight > getHeight()){
                break;
            }
        }
    }

    @Override
    public boolean canScrollVertically() {
        return true;
    }


    @Override
    public int scrollVerticallyBy(int dy, RecyclerView.Recycler recycler, RecyclerView.State state) {
        Log.d("feifeifei","getChildCount() " + getChildCount() + " recycler.getScrapList().size() " + recycler.getScrapList().size());

        //界面向下滚动的时候,dy为正,向上滚动的时候dy为负

        //向下滚动的时候,最下面的值不能超过总值,
        //向上滚动的时候,最上面的值不能小于0
        int canScroll = dy;
        if (dy>0){
            View  lastView = getChildAt(getChildCount() -1);
            int lastPos = getPosition(lastView);
            if (lastPos >= getItemCount()-1){
                if (lastView.getBottom() - dy < getHeight()){
                    canScroll = lastView.getBottom() - getHeight();
                    offsetChildrenVertical(canScroll*-1);
                    return 0;
                }
            }
        }else {
            View  firView = getChildAt(0);
            int firstPos = getPosition(firView);
            if (firstPos <= 0){
                if (firView.getTop() - dy >= 0){
                    canScroll = firView.getTop();
                    offsetChildrenVertical(canScroll*-1);
                    return 0;
                }
            }
        }

        //底部填充
        fill(dy,recycler,state);
        //滚动
        offsetChildrenVertical(dy*-1);

        //回收已经离开界面的
        recycleOut(dy,recycler,state);


        return dy;
    }

    private void fill(int dy, RecyclerView.Recycler recycler, RecyclerView.State state){
        //向下滚动
        if (dy > 0){
            //先在底部填充
            View  lastView = getChildAt(getChildCount() -1);
            int lastPos = getPosition(lastView);
            if (lastPos == getChildCount()-1){
                return;
            }
            Log.d("feifeifei","lastView top" + lastView.getTop() + " bottom " + lastView.getBottom());
            if (lastView.getBottom() -  dy < getHeight()){
                View scrap = recycler.getViewForPosition(lastPos+1);
                addView(scrap);
                measureChildWithMargins(scrap,0,0);
                int width = getDecoratedMeasuredWidth(scrap);
                int height = getDecoratedMeasuredHeight(scrap);
                layoutDecorated(scrap,0,lastView.getBottom(),width,lastView.getBottom()+height);
//                bottomItemPos++;
            }
        }else {
            //向上滚动
            //现在顶部填充
            View  firstView = getChildAt(0);
            Log.d("feifeifei","firstView top" + firstView.getTop() + " bottom " + firstView.getBottom());
            int layoutPostion = getPosition(firstView);
            if (layoutPostion == 0){
                return;
            }
            if (firstView.getTop() >= 0 ){
                View scrap = recycler.getViewForPosition(layoutPostion -1);
                addView(scrap,0);
                measureChildWithMargins(scrap,0,0);
                int width = getDecoratedMeasuredWidth(scrap);
                int height = getDecoratedMeasuredHeight(scrap);
                layoutDecorated(scrap,0,firstView.getTop() - height,width,firstView.getTop());
            }
        }
    }

        private void recycleOut(int dy, RecyclerView.Recycler recycler, RecyclerView.State state){
            for (int i = 0 ; i <getChildCount() ;i++){
                View view = getChildAt(i);

    //            Log.d("feifeifei","recycleOut position "+ i + " getDecoratedTop " + getDecoratedTop(view) + " getDecoratedBottom " + getDecoratedBottom(view));
                Log.d("feifeifei","recycleOut position "+ i + " top " + view.getTop() + " bottom " + view.getBottom());

                if (dy >0){
                    if (view.getBottom()-dy <0){
                        Log.d("feifeifei","recycleOut " + i);
                        removeAndRecycleView(view,recycler);
                    }
                }else {
                    if (view.getTop()-dy > getHeight()){
                        Log.d("feifeifei","recycleOut " + i);
                        removeAndRecycleView(view,recycler);
                    }
                }
            }
        }
}

然后通过adapter打印日志,onCreateViewHolder只打印了7次(我的界面上显示的7个item),然后滚动界面的时候,onBindViewHolder依次打印.看来回收还是成功的.这样一个简单版的带回收的LinearLayoutManager就好了

二、Resources 和 AssetManager

在 Android 开发中我们使用 Resources 来获取 res 目录下的各种与设备相关的资源。而使用 AssetManager 来获取 assets 目录下的资源。

一般来说 Resources 对象通过 Context 获得。
appContext 中的 resources 是在创建之后通过如下代码设置。
context.setResources(packageInfo.getResources());
而 LoadedApk 中则是通过如下代码创建：

            mResources = ResourcesManager.getInstance().getResources(null, mResDir,
                    splitPaths, mOverlayDirs, mApplicationInfo.sharedLibraryFiles,
                    Display.DEFAULT_DISPLAY, null, getCompatibilityInfo(),
                    getClassLoader());

其中 mResDir 对应 ApplicationInfo.sourceDir 字段

    /**
     * Full path to the base APK for this application.
     */
    public String sourceDir;

ResourcesManager.getInstance().getResources 的主要逻辑如下：

 final ResourcesKey key = new ResourcesKey(
                    resDir,
                    splitResDirs,
                    overlayDirs,
                    libDirs,
                    displayId,
                    overrideConfig != null ? new Configuration(overrideConfig) : null, // Copy
                    compatInfo);
            classLoader = classLoader != null ? classLoader : ClassLoader.getSystemClassLoader();
            return getOrCreateResources(activityToken, key, classLoader);

getOrCreateResources 主要逻辑如下：

 // 1) 先创建 ResourcesImpl
 ResourcesImpl resourcesImpl = createResourcesImpl(key);
// 2) 再创建 Resources
 resources = getOrCreateResourcesLocked(classLoader, resourcesImpl, key.mCompatInfo);
createResourcewImpl 主要逻辑如下：

  final AssetManager assets = createAssetManager(key);
        if (assets == null) {
            return null;
        }

        final DisplayMetrics dm = getDisplayMetrics(key.mDisplayId, daj);
        final Configuration config = generateConfig(key, dm);
        final ResourcesImpl impl = new ResourcesImpl(assets, dm, config, daj);

        return impl;

其中 createAssetManager(key) 的主要逻辑如下：

// 1） 创建 assets 对象实例。
  AssetManager assets = new AssetManager();
// 2) 添加各资源目录。
assets.addAssetPath(key.mResDir)
assets.addAssetPath(splitResDir) 
assets.addOverlayPath(idmapPath);
assets.addAssetPathAsSharedLibrary(libDir) 

最终 Resources 的创建逻辑如下：

// getOrCreateResourcesLocked
        Resources resources = compatInfo.needsCompatResources() ? new CompatResources(classLoader)
                : new Resources(classLoader);
        resources.setImpl(impl);

以 Resouces.getString 来查看资源的读取流程

1）调用 getText

 public String getString(@StringRes int id) throws NotFoundException {
        return getText(id).toString();
    }

2）通过 resourcesImpl 调用 AssetsManager 的 getResourceText

    @NonNull public CharSequence getText(@StringRes int id) throws NotFoundException {
        CharSequence res = mResourcesImpl.getAssets().getResourceText(id);
        if (res != null) {
            return res;
        }
        throw new NotFoundException("String resource ID #0x"
                + Integer.toHexString(id));
    }

3）getResourceText

@Nullable
 final CharSequence getResourceText(@StringRes int resId) {
     synchronized (this) {
         final TypedValue outValue = mValue;
         if (getResourceValue(resId, 0, outValue, true)) {
             return outValue.coerceToString();
         }
         return null;
     }
 }

4）getResourceValue

    final boolean getResourceValue(@AnyRes int resId, int densityDpi, @NonNull TypedValue outValue,
            boolean resolveRefs) {
        synchronized (this) {
            final int block = loadResourceValue(resId, (short) densityDpi, outValue, resolveRefs);
            if (block < 0) {
                return false;
            }

            // Convert the changing configurations flags populated by native code.
            outValue.changingConfigurations = ActivityInfo.activityInfoConfigNativeToJava(
                    outValue.changingConfigurations);

            if (outValue.type == TypedValue.TYPE_STRING) {
                outValue.string = mStringBlocks[block].get(outValue.data);
            }
            return true;
        }
    }

5）最后通过 loadResourceValue 这一原生方法读取。

   /** Returns true if the resource was found, filling in mRetStringBlock and
     *  mRetData. */
    private native final int loadResourceValue(int ident, short density, TypedValue outValue,
            boolean resolve);

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参考 https://www.jianshu.com/p/f775cfcae2f6
https://www.jianshu.com/p/1799e16c80f9