1

I have a Service which runs in the background when my app starts, and continues to run after the app is closed. It implements a Loader.OnLoadCompleteListener<Cursor> for a registered Uri from a Content Provider. When a new Cursor object is delivered on the callback method onLoadComplete(Loader<Cursor> loader, Cursor data) I then run an AsyncTask using the Cursor to create an ArrayList of custom Objects that implement the Parcelable interface. Once processed, if the app is open it sends back to the App getting marshalled/demarshalled using the IPC framework using a Handler with Messenger,Messages and aBundle. If the App is not open then the ArrayList is ready to be sent back to the App once opened, which calls to the Service when opened.

Problem:

The ArrayList can get relatively large (it doesn't contain Bitmaps, only Primitives and several short String objects) and the sheer amount means it hits the FAILED BINDER TRANSACTION when the ArrayList gets to about 700 objects.

Current Solution (that feels a bit hacky)

I am splitting the ArrayList into chunks and sending several Messages back to the Handler where it is then reconstructed into one ArrayList and then used in the App (updating RecyclerViews etc..).

I use this approach as the performance is significantly improved - only need to do initial query when App/Service is started first time, rather than always querying the Content Provider every time the App is opened.

The reason I say 'hacky' is because this feels like a workaround for a limitation of the Binder Framework rather than a solution.

Any advise on approaching this differently would be welcomed.

Onik
  • 19,396
  • 14
  • 68
  • 91
Mark
  • 9,604
  • 5
  • 36
  • 64

1 Answers1

1

Two alternatives that come in my mind is:

  1. Having a static ArrayList inside your service and sending a broadcast when the cursor received to the Activity to copy the contents of the static Arraylist which is inside the service in the local arraylist inside the activity. With this way Activity only has reference of the static aarraylist only the time it copies the contents.

  2. I would save the contents in sql database asynchronously and then send broadcast to activity to retrieve asyncrhonously again the cursor from the database. On the UI thread then I would call notifydatasetChanged on the adapter.

z3n105
  • 1,935
  • 1
  • 15
  • 14
  • thanks for your response, both ideas very plausible. I did think of using a static ArrayList but try to avoid static variables for reasons of scope and in this case accessing a global variable which other threads to could try to access and modify at the same time. I will probably go with an Sql database, or start again using an entirely different approach. – Mark Mar 23 '16 at 17:27
  • I would go for the second approach as well I agree with your observations. Would be interesting if we could get another answer I'm interested as well. – z3n105 Mar 23 '16 at 17:32
  • I've decided to take a different approach - I shall use a custom AsyncTaskLoader - this should, if implemented correctly, provide the stability I'm after. Using a database in this instance feels like doubling up a process - to query a content provider, then to insert data into my own database feels like doubling up a process, as i'll just have to then query the database again and create custom POJO objects form it anyway. – Mark Mar 25 '16 at 12:01