java - 解码为 Bitmap 和压缩期间内存泄漏

Question

我一直在研究以下代码，它在 android 平板电脑上打开存储的图像，将其解码为位图，然后将其转换为 base64 字符串，以便可以将其存储在 SQLite 数据库中。

据我所知，多达 2MB 的数据从该事务中泄漏，对该函数的多次调用占用越来越多的内存，而这些内存未被正确地垃圾收集。

填充 origin_photo 后，它大约占用 49kb，一旦转换为 base64，它大约占用 65kb。

photo.insert 函数是一个简单的 SQLite base64 插入以及一些小信息。我不认为这是问题的一部分。

此功能完成后，我还在日志 cat 中收到一条消息“跳过 57 帧!应用程序可能在其主线程上做了太多工作”(没有任何断点会减慢代码速度)

我可能弄错了，这是导致泄漏的代码附近运行的不同部分，但这似乎是最有可能的候选者。非常感谢任何帮助。

更新:base64.encodeBytes 函数取自

http://iharder.net/base64

public void savePhoto() 
{
    try
    {
        String[] projection = { MediaStore.Images.Media.DATA };
        //Get last captured image in db
        String capturedImageFilePath = null;
        try
        {
            //NOTE: The warning on activity.managedQuert states you must NOT close the cursor it creates yourself 
            Cursor cursor = activity.managedQuery(mCapturedImageURI, projection, null, null, null); 
            int column_index_data = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA); 
            cursor.moveToFirst(); 
            //Get file path from last stored photo
            capturedImageFilePath = new String(cursor.getString(column_index_data));
            //cursor.close();
        }
        catch(IllegalArgumentException e)
        {
            ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO_GET_IMAGE_FILE_PATH, this.getActivity());
        }
        catch(NullPointerException e)
        {
            ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO_GET_IMAGE_FILE_PATH, this.getActivity());
        }
        catch(Exception e) 
        {
            ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO_GET_IMAGE_FILE_PATH, this.getActivity()); 
        }

        int orientation = -1;
        //Get Exif data from current image and store orientation
        //Note exif data will be stripped when this filepath is turned
        //into a bitmap
        try 
        {
            ExifInterface e = new ExifInterface(capturedImageFilePath);
            orientation = e.getAttributeInt("Orientation", -1);
        }
        catch (IOException ioe) 
        {
            ioe.printStackTrace();
            ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO_EXIF_DATA_IO, this.getActivity());
        }
        catch(Exception e) { ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO_EXIF_DATA_GENERAL, this.getActivity()); }

        //Decode current photo into a Bitmap
        Bitmap b = BitmapFactory.decodeFile(capturedImageFilePath);

        if(b == null)
        {
            Log.d("activitycrossellcalls", "error open " + capturedImageFilePath);
            ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO_NULL_BITMAP, this.getActivity());
        }
        else 
        {
            int width = -1;
            int height = -1;

            width = b.getWidth();
            height = b.getHeight();
            Log.d("activitycrossellcalls", "w: "+width+", h:"+height);
            //Scale down if too big
            int max = (width > height)?width:height;
            float ratio = 1;
            if(max > MAX_IMAGE_SIZE)
                ratio = (float)max/(float)MAX_IMAGE_SIZE;
            width /= ratio;
            height /= ratio;

            b = Photos.getResizedBitmap(b, height, width);

            Log.i("activitycrossellcalls", "new w: " + width + ", h: " + height);

            // Encode
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            b.compress(Bitmap.CompressFormat.JPEG, 70, baos);
            b.recycle();


            byte[] origin_photo = null;

            origin_photo = baos.toByteArray();

            // Insert               
            Photo photo = null;
            try
            {
                photo = new Photo();
                photo.base64 = Base64.encodeBytes(origin_photo);
                photo.call = DailyCallsDetailsActivity.call.id;
                photo.tag_id = TaggingActivity.currentTag.id;
                photo.orientation = orientation;
            }
            catch(Exception e) { ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO_INIT, this.getActivity()); }

            photo.insert();
        }
    }
    catch(Exception e) { ErrorCodes.CreateError(ErrorCodes.DCDF_SAVE_PHOTO, this.getActivity()); }
}        

.

public static Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) 
{
    try
    {
        int width = bm.getWidth();
        int height = bm.getHeight();
        float scaleWidth = ((float) newWidth) / width;
        float scaleHeight = ((float) newHeight) / height;
        // CREATE A MATRIX FOR THE MANIPULATION
        Matrix matrix = new Matrix();
        // RESIZE THE BIT MAP
        matrix.postScale(scaleWidth, scaleHeight);
        // RECREATE THE NEW BITMAP
        Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
        bm.recycle();
        return resizedBitmap;
    }
    catch(Exception e) { ErrorCodes.ReportError(ErrorCodes.PHOTS_GET_RESIZED_BITMAP); return null; }
}

Answer 1

我想我找到了

Bitmap b = BitmapFactory.decodeFile(capturedImageFilePath);
...
b = Photos.getResizedBitmap(b, height, width);

你不是在回收原来的 b。这不应该是永久性泄漏，但肯定会导致 GC 崩溃。

您可能还想考虑使用 LRUCache 来自动循环进出位图。