Question

I am uploading a video file using an Async Task. To track the progress I have a notification running in the statusbar. The notification works and updates correctly, but it causes severe performance issues to the extent where the statusbar crashes and the phone needs to be restarted. My code as follows:

    private class UploadMedia extends AsyncTask<Void, Integer, String> {

    private int NOTIFICATION_ID = 1;
    private CharSequence _contentTitle;
    private final NotificationManager _notificationManager = (NotificationManager) getActivity()
            .getApplicationContext()
            .getSystemService(
                    getActivity().getApplicationContext().NOTIFICATION_SERVICE);
    Notification _notification;
    PendingIntent _pendingIntent;

    private long totalSize;
    private int _progress = 0;
    private InputStreamBody isb;
    private File uploadFile;

    protected void onPreExecute() {

        Intent intent = new Intent();
        _pendingIntent = PendingIntent.getActivity(getActivity(), 0,
                intent, 0);

        _contentTitle = "Uploader " + mediaTitle + " til Skoletube";
        CharSequence contentText = _progress + "% complete";

        _notification = new Notification(R.drawable.icon, _contentTitle,
                System.currentTimeMillis());
        _notification.flags = _notification.flags
                | Notification.FLAG_ONGOING_EVENT;
        _notification.contentIntent = _pendingIntent;
        _notification.setLatestEventInfo(getActivity(), _contentTitle,
                contentText, _pendingIntent);

        _notificationManager.notify(NOTIFICATION_ID, _notification);

        Toast.makeText(getActivity(), "Starter upload", Toast.LENGTH_SHORT)
                .show();

        try {
            uploadFile = new File(_mediaFile.getPath());

            // FileInputStream is = new FileInputStream(uploadFile);
            //
            // ByteArrayOutputStream bos = new ByteArrayOutputStream();
            // byte[] b = new byte[1024];
            // int bytesRead;
            // while ((bytesRead = is.read(b)) != -1) {
            // bos.write(b, 0, bytesRead);
            // }
            // byte[] data = bos.toByteArray();
            //
            // isb = new InputStreamBody(new ByteArrayInputStream(data),
            // uploadFile.getName());

        } catch (Exception ex) {
            Log.i(TAG,
                    "Pre execute - oh noes... D: "
                            + ex.getLocalizedMessage());
        }

    }

    @Override
    protected String doInBackground(Void... params) {
        String result = "";
        try {
            // Inititate connectionparts
            HttpClient client = new DefaultHttpClient();
            HttpPost postRequest = new HttpPost(
                    "http://www.skoletube.dk/beta/api_userupload.php");

            CustomMultipartEntity multipartE = new CustomMultipartEntity(
                    HttpMultipartMode.BROWSER_COMPATIBLE,
                    new ProgressListener() {

                        @Override
                        public void transferred(long num) {
                            publishProgress((int) ((num / (float) totalSize) * 100));

                        }
                    });

            // Add the post elements
            String timestamp = String
                    .valueOf(System.currentTimeMillis() / 1000);
            String mode = "xml";
            String hashSum = Utils.md5(ActiveUser.getPartner() + timestamp
                    + ActiveUser.getInstance().getToken()
                    + ActiveUser.getInstance().getSecret()
                    + ActiveUser.getInstance().getUserID()
                    + spnChannel.getSelectedItem().toString()
                    + mediaDescribtion + "KEYWORDLOL"
                    + spnPublic.getSelectedItem().toString() + mediaTitle
                    + ActiveUser.getSharedkey());

            multipartE.addPart("uid", new StringBody(ActiveUser
                    .getInstance().getUserID()));
            multipartE.addPart("token", new StringBody(ActiveUser
                    .getInstance().getToken()));
            multipartE.addPart("token_secret", new StringBody(ActiveUser
                    .getInstance().getSecret()));
            multipartE.addPart("partner",
                    new StringBody(ActiveUser.getPartner()));
            multipartE.addPart("timestamp",
                    new StringBody(timestamp.toString()));
            multipartE.addPart("key", new StringBody(hashSum));
            multipartE.addPart("video_title", new StringBody(mediaTitle));
            multipartE.addPart("video_desc", new StringBody(
                    mediaDescribtion));
            multipartE.addPart("video_keyword",
                    new StringBody("KEYWORDLOL"));
            multipartE.addPart("video_privacy", new StringBody(spnPublic
                    .getSelectedItem().toString()));
            multipartE.addPart("video_channel", new StringBody(spnChannel
                    .getSelectedItem().toString()));
            multipartE.addPart("videoupload", new FileBody(uploadFile));

            postRequest.setEntity(multipartE);

            totalSize = multipartE.getContentLength();


            HttpResponse loginResponse = client.execute(postRequest);
            HttpEntity theEnt = loginResponse.getEntity();
            result = EntityUtils.toString(theEnt);

            Log.i(TAG, "Result: " + result);

        } catch (Exception ex) {
            Log.i(TAG,
                    "Do in background - oh noes... D: "
                            + ex.getLocalizedMessage());

        }
        return result;
    }

    @Override
    protected void onProgressUpdate(Integer... progress) {
        if (_notification == null)
            return;
        _progress = progress[0];
        _contentTitle = "Uploader " + mediaTitle + " til Skoletube";
        CharSequence contentText = _progress + "% complete";
        _notification.setLatestEventInfo(getActivity(), _contentTitle,
                contentText, _pendingIntent);
        _notificationManager.notify(NOTIFICATION_ID, _notification);
    }

    @Override
    protected void onPostExecute(String result) {
        _notificationManager.cancel(NOTIFICATION_ID);
    }

}

I am testing this on a HTC Sensation. The problems occur the instant I press the notification bar, causing it to expand. The phone freezes and its touch and go whether I will actually get to the notification bar or the notification bar will crash. If i do get to the notification bar the performance issues persist, and closing the notification bar again is just as tricky as opening it.
What I’m thinking is maybe the sheer amount of notification updates sent could be causing the problem, but I am not sure.

Appreciate any ideas and suggestions.

Answer 1

Your suspicions are right.
The following instruction

publishProgress((int) ((num / (float) totalSize) * 100));

will be called very frequently, at short intervals.

What I would do in such situation is to store the pourcent avancement I want to display and send it only if it changed since the latest call.

In the doInBackground method, you can declare a variable such as:

int lastPourcent = 0;

Then, in the transferred method:

int currentPoucent = (int) ((num / (float) totalSize) * 100);
if (currentPourcent > lastPourcent) {
    publishProgress(currentPourcent);
    lastPourcent = currentPourcent;
}

It will significantly reduce the number of call to the refresh method of the Notification.