picasso: Picasso suddenly stops displaying images which previously worked

I commented on #626, but this might be a new issue, so I moved it here.

Not sure if Picasso can do anything about it, but I believe I found a possible issue related to disk caching:

Images that previously loaded fine suddenly stop working. Instead of the image, a black screen is displayed and the error image specified in .error() is NOT loaded. Restarting the app or the device doesn’t clear the problem, but uninstall/reinstall does. After a reinstall images are loaded normally.

Based on this, I figured it must be a disk caching problem, and most probably the cached images are defunct. So I want to tell you what I did and what might have caused this:

I am loading a lot of large images into a scroll view, of which most are outside the viewport. So I played with removing images from imageViews that are currently not visible. I randomly applied the following code found here http://stackoverflow.com/questions/8349958/imageview-automatically-recycle-bitmap-if-imageview-is-not-visible-within-scro - or parts of it:

        if(view instanceof ImageView)
        {
            Drawable drawable = ((ImageView)view).getDrawable();
            if(drawable instanceof BitmapDrawable)
            {
                BitmapDrawable bitmapDrawable = (BitmapDrawable)drawable;
                bitmapDrawable.getBitmap().recycle();
            }
        }

        if (view instanceof ViewGroup) {
            for (int i = 0; i < ((ViewGroup) view).getChildCount(); i++) {
                recycleImagesFromView(((ViewGroup) view).getChildAt(i));
            }
        }

It seems like Picasso still held a reference to the drawable at the same time and recycling the drawable destroyed it in the other thread, which rendered it defunct. But Picasso still believes it has a valid drawable cached and tries to reuse it the next time it is loaded.

Possibly a simple check if a cached image is valid - and reverting to loading from memory or the network in case it is not - would fix the problem.

Here my original post:

I don’t know if this is related, but Picasso suddenly stopped displaying certain images (which were most possibly cached on disk). After uninstall/reinstall it worked normally again.

before:

04-11 08:36:38.900 20448-20448/cc.closeup.android D/Picasso﹕ Main created [R0] Request{https://storage.googleapis.com/closeup0002/7836f5829298440787be11cf53b8fd39.jpeg resize(1280,720) centerCrop} 04-11 08:36:38.910 20448-20740/cc.closeup.android D/Picasso﹕ Dispatcher enqueued [R0]+15ms 04-11 08:36:38.915 20448-20770/cc.closeup.android D/Picasso﹕ Hunter executing [R0]+20ms 04-11 08:36:38.935 20448-20448/cc.closeup.android D/Picasso﹕ Main created [R2] Request{https://storage.googleapis.com/closeup0002/8edb01cc933942439b815c32b62aff39.jpeg resize(1280,720) centerCrop} 04-11 08:36:38.940 20448-20448/cc.closeup.android D/Picasso﹕ Main created [R4] Request{https://storage.googleapis.com/closeup0002/a7c0aeb1914248aaaffc7bcc549ff8db.jpeg resize(1280,720) centerCrop} 04-11 08:36:38.940 20448-20743/cc.closeup.android D/Picasso﹕ Dispatcher enqueued [R2]+7ms 04-11 08:36:38.950 20448-20777/cc.closeup.android D/Picasso﹕ Hunter executing [R4]+11ms 04-11 08:36:38.950 20448-20746/cc.closeup.android D/Picasso﹕ Dispatcher enqueued [R4]+11ms 04-11 08:36:38.950 20448-20776/cc.closeup.android D/Picasso﹕ Hunter executing [R2]+16ms 04-11 08:36:39.500 20448-20746/cc.closeup.android D/Picasso﹕ Dispatcher retrying [R4]+559ms 04-11 08:36:39.500 20448-20784/cc.closeup.android D/Picasso﹕ Hunter executing [R4]+563ms 04-11 08:36:39.505 20448-20740/cc.closeup.android D/Picasso﹕ Dispatcher retrying [R0]+605ms 04-11 08:36:39.505 20448-20743/cc.closeup.android D/Picasso﹕ Dispatcher retrying [R2]+568ms 04-11 08:36:39.505 20448-20786/cc.closeup.android D/Picasso﹕ Hunter executing [R2]+570ms 04-11 08:36:39.505 20448-20787/cc.closeup.android D/Picasso﹕ Hunter executing [R0]+610ms

after:

04-11 08:40:08.380 22348-22348/cc.closeup.android D/Picasso﹕ Main created [R0] Request{https://storage.googleapis.com/closeup0002/7836f5829298440787be11cf53b8fd39.jpeg resize(1280,720) centerCrop} 04-11 08:40:08.385 22348-22348/cc.closeup.android D/Picasso﹕ Main created [R2] Request{https://storage.googleapis.com/closeup0002/8edb01cc933942439b815c32b62aff39.jpeg resize(1280,720) centerCrop} 04-11 08:40:08.390 22348-22348/cc.closeup.android D/Picasso﹕ Main created [R4] Request{https://storage.googleapis.com/closeup0002/a7c0aeb1914248aaaffc7bcc549ff8db.jpeg resize(1280,720) centerCrop} 04-11 08:40:08.395 22348-22764/cc.closeup.android D/Picasso﹕ Dispatcher enqueued [R2]+7ms 04-11 08:40:08.395 22348-22808/cc.closeup.android D/Picasso﹕ Hunter executing [R2]+8ms 04-11 08:40:08.405 22348-22767/cc.closeup.android D/Picasso﹕ Dispatcher enqueued [R4]+14ms 04-11 08:40:08.405 22348-22810/cc.closeup.android D/Picasso﹕ Hunter executing [R4]+16ms 04-11 08:40:08.410 22348-22761/cc.closeup.android D/Picasso﹕ Dispatcher enqueued [R0]+32ms 04-11 08:40:08.415 22348-22812/cc.closeup.android D/Picasso﹕ Hunter executing [R0]+35ms 04-11 08:40:09.150 22348-22812/cc.closeup.android D/Picasso﹕ Hunter decoded [R0]+774ms 04-11 08:40:09.160 22348-22808/cc.closeup.android D/Picasso﹕ Hunter decoded [R2]+771ms 04-11 08:40:09.160 22348-22810/cc.closeup.android D/Picasso﹕ Hunter decoded [R4]+772ms 04-11 08:40:09.320 22348-22812/cc.closeup.android D/Picasso﹕ Hunter transformed [R0]+943ms 04-11 08:40:09.370 22348-22761/cc.closeup.android D/Picasso﹕ Dispatcher batched [R0]+991ms for completion 04-11 08:40:09.415 22348-22808/cc.closeup.android D/Picasso﹕ Hunter transformed [R2]+1027ms 04-11 08:40:09.430 22348-22764/cc.closeup.android D/Picasso﹕ Dispatcher batched [R2]+1044ms for completion 04-11 08:40:09.535 22348-22810/cc.closeup.android D/Picasso﹕ Hunter transformed [R4]+1145ms 04-11 08:40:09.535 22348-22767/cc.closeup.android D/Picasso﹕ Dispatcher batched [R4]+1145ms for completion 04-11 08:40:09.570 22348-22761/cc.closeup.android D/Picasso﹕ Dispatcher delivered [R0]+1193ms 04-11 08:40:09.570 22348-22348/cc.closeup.android D/Picasso﹕ Main completed [R0]+1192ms from NETWORK 04-11 08:40:09.685 22348-22764/cc.closeup.android D/Picasso﹕ Dispatcher delivered [R2]+1246ms 04-11 08:40:09.700 22348-22348/cc.closeup.android D/Picasso﹕ Main completed [R2]+1314ms from NETWORK 04-11 08:40:09.735 22348-22767/cc.closeup.android D/Picasso﹕ Dispatcher delivered [R4]+1346ms 04-11 08:40:09.745 22348-22348/cc.closeup.android D/Picasso﹕ Main completed [R4]+1357ms from NETWORK