Android Fresco调优实践

private void updatePaint() {   
     if (mLastBitmap == null || mLastBitmap.get() != mBitmap) {            
           mLastBitmap = new WeakReference<>(mBitmap);  
           mPaint.setShader(new BitmapShader(mBitmap, Shader.TileMode.CLAMP,   
           Shader.TileMode.CLAMP));     
              mIsShaderTransformDirty = true;   
           }   
    if (mIsShaderTransformDirty) {        
          mPaint.getShader().setLocalMatrix(mTransform);        
         mIsShaderTransformDirty = false;  
      }  
     mPaint.setFilterBitmap(getPaintFilterBitmap());
 }

//设置path的核心代码
if (mIsCircle) {  
    mPath.addCircle( mRootBounds.centerX(), mRootBounds.centerY(),      
     Math.min(mRootBounds.width(), mRootBounds.height()) / 2,      
     Path.Direction.CW);
} else if (mScaleDownInsideBorders) { 
 if (mInsideBorderRadii == null) {   
   mInsideBorderRadii = new float[8];  
  } 
   for (int i = 0; i < mBorderRadii.length; i++) {  
     mInsideBorderRadii[i] = mCornerRadii[i] - mBorderWidth; 
      }  
      mPath.addRoundRect(mRootBounds,mInsideBorderRadii,Path.Direction.CW);} 
   else {
      mPath.addRoundRect(mRootBounds,mCornerRadii,Path.Direction.CW);
}

//设置RootBounds的核心代码
if (mTransformCallback != null) {  mTransformCallback.getTransform(mParentTransform);  mTransformCallback.getRootBounds(mRootBounds);} else {  mParentTransform.reset();  mRootBounds.set(getBounds());
}

@JvmStatic fun loadNinePatchBackground(image: ImageView, url: String) {    //获取.9图的cdn下载文件  
  loadImageAsFile(url, {        
  //通过BitmapFactory进行解码 获取bitmap  
        val bitmap=BitmapFactory.decodeFile(it.path)?:return@loadImageAsFile   
        val chunk = bitmap.ninePatchChunk  
               //将bitmap数据封装到NinePatchDrawable中         
              image.resources?.apply {    
                 val defaultDrawable = if(NinePatch.isNinePatchChunk(chunk))       
            {           
             NinePatchDrawable(this, bitmap, chunk, Rect(), null)       
            } else {            
              BitmapDrawable(this, bitmap)   
            }      
              //设置核心图片背景     
              image.background = defaultDrawable      
            }  
            })
          }

/***
 * @param density 对应本地图的匹配density,默认为0，不进行inDensity配置。对于部分可变分辨率手机，可能会存在.9拉伸的问题，需要指定输入输出density。
 * * 参数说明:
 * * mdpi--> DisplayMetrics.DENSITY_MEDIUM
 * *hdpi --> DisplayMetrics.DENSITY_HIGH
 * * xhdpi  -->DisplayMetrics.DENSITY_XHIGH
 * * xxhdpi  -->DisplayMetrics.DENSITY_XXHIGH
 * * xxxhdpi  -->DisplayMetrics.DENSITY_XXXHIGH
 */
@JvmStatic fun loadNinePatchBackgroundForView(view: View, url: String, density: Int = 0) {  
    loadImageAsFile(url, {   
        var options: BitmapFactory.Options? = null     
        options = BitmapFactory.Options()     
        options.inDensity = density      
        options.inTargetDensity = DisplayMetrics.DENSITY_DEVICE_STABLE   
        BitmapFactory.decodeFile(it.path)    
        val bitmap = BitmapFactory.decodeFile(it.path, options) ?: return@loadImageAsFile 
        val chunk = bitmap.ninePatchChunk  
        view.resources?.apply {  
            val defaultDrawable = if (NinePatch.isNinePatchChunk(chunk)) {  
                val rect = if (DuImageGlobalConfig.enableNewNinePatchLoad) {  
                    Rect(chunk[12].toInt(), chunk[20].toInt(), chunk[16].toInt(), chunk[24].toInt())    
                }            
                NinePatchDrawable(this, bitmap, chunk, rect, null)      
            } else {
                BitmapDrawable(this, bitmap)     
            }          
            view.background = defaultDrawable     
        }    
    })}

//重写测量宽高的实现
 @Override public int getIntrinsicHeight() {   
     Bitmap bitmap = this.mBitmap;   
    if (bitmap != null) {     
        return bitmap.getHeight();    
    }    
    return super.getIntrinsicHeight();
 }
 
 @Override public int getIntrinsicWidth() {
    Bitmap bitmap = this.mBitmap; 
    if (bitmap != null) {
        return bitmap.getWidth(); 
    }  
    return super.getIntrinsicWidth();
}

//cursor 获取具体的pathName
final String pathname = cursor.getString(cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA));if (pathname != null) {
 try {
//通过ExifInterface获取图片的旋转角度
ExifInterface exif = new ExifInterface(pathname);
    orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
    rotationAngle = JfifUtil.getAutoRotateAngleFromOrientation(orientation);    
    } catch (IOException ioe) {
        FLog.e(PRODUCER_NAME, ioe, "Unable to retrieve thumbnail rotation for %s", pathname);    }
}..... //此处省略部分代码实现
//构造CloseableStaticBitmap时，传入旋转的角度与方向CloseableStatic
Bitmap closeableStaticBitmap =new CloseableStaticBitmap(
loadThumbnail,
SimpleBitmapReleaser.getInstance(),
ImmutableQualityInfo.FULL_QUALITY,
rotationAngle, orientation)

try {   
    loadThumbnail = mContentResolver.loadThumbnail(imageRequest.getSourceUri(),
        new Size(imageRequest.getPreferredWidth(), imageRequest.getPreferredHeight()), cancellationSignal);
} catch (IOException exception) {   
    if (exception.getMessage() != null && exception.getMessage().contains("Failed to create thumbnail")) {    
        if (imageRequest.getMimeType() != null && HEIF_MIME_TYPE.contains(imageRequest.getMimeType())) {     
            String path = getRealPathFromUri(mContentResolver
        }, imageRequest.getSourceUri());       
        if (path != null) {          
            File file = new File(path)
        };             
        FileInputStream fileInputStream = new FileInputStream(file);    
        //读取头文件 做实际的判断           
        String type = ImageFormatChecker.getInstance().determineImageFormat(fileInputStream).getFileExtension();       
        //暂时只判断heif, avif格式的误判 暂时没做头文件 format检测      
        if (type != null && !type.equals(HEIF_FORMAT_EXTENSION)) {         
            loadThumbnail = createImageThumbnail(file, new Size(imageRequest.getPreferredWidth(), imageRequest.getPreferredHeight())
        }, cancellationSignal);
            if (loadThumbnail != null) {
            }
        }                 
//补充异常兜底事件抛到业务层          
producerContext.getProducerListener().onProducerEvent(producerContext, PRODUCER_NAME, THUMBNAIL_FALL_BACK_EVENT);     
}             
}        
}      
} else {    
    //此处抛出异常 会被onProducerFailed 处理 上层能监控到    
throw exception;      
}  
}}
}

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
    loadThumbnail = mContentResolver.loadThumbnail(
        imageRequest.getSourceUri(),
        new Size (imageRequest.getPreferredWidth(),
        imageRequest.getPreferredHeight()
    ), null);
} else {
    long videoId = - 1; try {
        videoId = ContentUris.parseId(imageRequest.getSourceUri()); } catch (Exception e) {
        FLog.w(
            PRODUCER_NAME,
            imageRequest.getSourceUri().toString() + " find exception " + e.getLocalizedMessage()
        ); }    if (videoId > 0) {
        loadThumbnail = MediaStore.Video.Thumbnails.getThumbnail(
            mContentResolver,
            videoId,
            calculateKind(imageRequest),
            null
        ); }
}

if (imageRequest.isResizingThumbnail() && imageRequest.getResizeOptions() != null) {
    if (bitmap.getHeight() <= 0 || bitmap.getWidth() <= 0) return
};
ResizeOptions resizeOptions = imageRequest.getResizeOptions();
int resizeWidth = resizeOptions.width;
int resizeHeight = resizeOptions.height;
if (resizeWidth <= 0 || resizeHeight <= 0 ) return;
//计算缩略图的宽高比   
float radio = (float) bitmap.getWidth() / bitmap.getHeight();
float tempWidth = resizeWidth;
float tempHeight = resizeHeight;
// 如果 resize的宽高比 大于 实际原图的话,那就需要对图片做调整  
if (tempWidth / tempHeight > radio) {
    resizeHeight = (int)(tempWidth / radio);
} else {
    resizeWidth = (int)(tempHeight * radio);
}
bitmap = Bitmap.createScaledBitmap(bitmap, resizeWidth, resizeHeight, true);
}

private void prepareFrame(final int frameNumber) {
// 先从缓存中取  
    BitmapFrameCache mBitmapFrameCache = mAnimationBackend . mBitmapFrameCache;
    CloseableReference<Bitmap> bitmapReference = mBitmapFrameCache . getCachedFrame (frameNumber);
    if (bitmapReference == null || !bitmapReference.isValid()) {
        // 缓存中没有，new Bitmap并保存    
        try {
            bitmapReference = mAnimationBackend.mPlatformBitmapFactory.createBitmap(
                mAnimationBackend.getIntrinsicWidth(),
                mAnimationBackend.getIntrinsicHeight(),
                Bitmap.Config.ARGB_8888
            )
        };
    } catch (OutOfMemoryError e) {
        //埋点上报逻辑       
    }
// 新建出来的对象也不可用  丢弃当前帧     
    if (bitmapReference == null || !bitmapReference.isValid()) {
        return;
    }
    Bitmap bitmap = bitmapReference . get ();
    if (bitmap.isRecycled()) {
        return; }
    mAnimationBackend.mAnimatedImageCompositor.renderFrame(frameNumber, bitmap);
// 动图不再写入内存缓存    
    mBitmapFrameCache.onFrameRendered(
        frameNumber,
        bitmapReference,
        BitmapAnimationBackend.FRAME_TYPE_CACHED
    );
}
mAnimationBackend.mCurrentFrame.put(frameNumber, bitmapReference);}
}
}

@Override public boolean equals(Object obj) {
    if (this == obj) {
        return true;
    }
}
if (obj == null || getClass() != obj.getClass()) {
    return false;
}
AnimationFrameCacheKey that = (AnimationFrameCacheKey) obj;
//equals 仅对比mAnimationUriString  
return mAnimationUriString.equals(that.mAnimationUriString);
}
@Overridepublic int hashCode() {
    //hashCode 仅对比mAnimationUriString的hashCode 即 anim:// + 图片URI hashcode 
    return mAnimationUriString.hashCode();
}
}

private BitmapFrameCache createBitmapFrameCache(AnimatedImageResult animatedImageResult) {
    int cacheKeyHash;
    if (DuImageGlobalConfig.isEnableAnimatedCompareOnlyUri() && animatedImageResult.getSourceUri() != null && !animatedImageResult.getSourceUri()
            .isEmpty()
    ) {
        //动图cacheKeyHash 仅采用SourceUri      
        cacheKeyHash = animatedImageResult.getSourceUri().hashCode();
    } else {        //原有逻辑       
        cacheKeyHash = animatedImageResult.hashCode();
    }
    return new FrescoFrameCache (new AnimatedFrameCache (new AnimationFrameCacheKey (cacheKeyHash, DuImageGlobalConfig.isEnableNewAnimatedCache()), mBackingCache), DuImageGlobalConfig.isEnableNewAnimatedCache());
}
}

// 先从内存缓存中取 
BitmapFrameCache mBitmapFrameCache = mAnimationBackend.mBitmapFrameCache;
CloseableReference<Bitmap> bitmapReference = mBitmapFrameCache.getCachedFrame(frameNumber);
if (DuImageGlobalConfig.isEnableNewAnimatedCache() && (bitmapReference == null || !bitmapReference.isValid())) {
//从无引用的缓存中在尝试取一次   
    bitmapReference = mBitmapFrameCache.getBitmapToReuseForFrame(
        frameNumber,
        mAnimationBackend.getIntrinsicWidth(),
        mAnimationBackend.getIntrinsicHeight()
    );
//获取到后重新写入内存缓存   
    mBitmapFrameCache.onFramePrepared(
        frameNumber,
        bitmapReference,
        BitmapAnimationBackend.FRAME_TYPE_CACHED
    );
}
}

//当前view的tag 与 加载url不相等
if(view.tag != image.url){ 
    view.loadwith(image.url).apply{
        view . tag = image . url
    } 
}