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POMoving from CursorAdapter to an Endless adapter implementation
 

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    <p>I am developing an app for Android Api 15 and above.</p> <p>I have been using a custom <code>CursorAdapter</code> implementation with a <code>ListView</code> for some time now. I was under the impression that even with many thousands of rows (records) the <code>ListView</code> would handle the performance side of things. </p> <p>My phone, a Sony Xperia U, has a hard time scrolling beyond 10 - 20 rows. The first few rows scroll nicely and then I hit a wall of stuttering and the device becoming unresponsive (A total of 70 rows all together). It is running Android 4.0.4. Other phones such as the Samsung S3 and Sony Xperia Z perform much better, but at what point is this going to degrade. These 2 phones are running 4.1. I am getting the <code>CursorWindow</code> warning seen below on the Xperia U.</p> <p>I have implemented all the tricks in the trade, <code>ViewHolder</code> pattern etc, and all images are loaded inside <code>AsyncTask</code>'s.</p> <p>Anyway, the trouble I am having regarding performance does not lie inside the <code>BindView</code>. The <code>BindView</code> method completes quite quickly - within 1-3 milliseconds.</p> <p>The problem I believe lies with the <code>CursorWindow</code>. I really don't even know what this is!</p> <pre><code>08-14 21:01:58.913: W/CursorWindow(7116): Window is full: requested allocation 277981 bytes, free space 148792 bytes, window size 2097152 bytes </code></pre> <p>I also read there is an issue in <code>CursorWindow</code> up to potentially 4.2 but this could be false:</p> <blockquote> <p><a href="http://code.google.com/p/android/issues/detail?can=2&amp;start=0&amp;num=100&amp;q=&amp;colspec=ID%20Type%20Status%20Owner%20Summary%20Stars&amp;groupby=&amp;sort=&amp;id=4993" rel="nofollow">http://code.google.com/p/android/issues/detail?can=2&amp;start=0&amp;num=100&amp;q=&amp;colspec=ID%20Type%20Status%20Owner%20Summary%20Stars&amp;groupby=&amp;sort=&amp;id=4993</a></p> </blockquote> <p>When it comes to the data for each row, I have an <code>SQLite</code> <code>blob</code>:</p> <pre><code>byte[] avatar = cursor.getBlob(cursor.getColumnIndex(Profile.TABLE_COLUMN_AVATAR)); </code></pre> <p>I think this might be one of the issues, but I am uncertain. I probably should switch the image/s to an SD card and store the path in the DB instead. I would like to keep my current setup though.</p> <p>This then suggests that my current approach is not going to be manageable and hence a new approach might be necessary. So this gets me thinking about an Endless Adapter solution which would mean getting the cursor data with a limit/offset and filling up an <code>ArrayAdapter</code> and using a framework like CommonWare's <code>EndlessAdapter</code> (perhaps)?</p> <ol> <li>Does my performance problem lie less with the <code>CursorAdapter</code> and more with the use of <code>Blob</code>s?</li> <li>Should I be using an Endless Adapter approach with potentially large data sets?</li> <li>Is CommonWare's <code>EndlessAdapter</code> still a good solution after 4 years?</li> </ol>
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    1. COIt's very likely something to do with your blob is a major source of your issues. There's an easy way to check. Comment it out (and related relevant code) and try. Keep in mind that either way, your image loading should not be on the main thread and you should be doing it asynchronously.
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    2. CO@kabuko Yes I have read that it might be. I have commented out all the code except a little text (`TextView`). I still get the unresponsive stuttering after 10 - 20 rows especially when scrolling up. The Cursor with the blob is still being created and passed to `bindView` even though I am not using it - could this CursorWindow be the culprit?
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    3. CO@kabuko I will now modify my query to request all fields except the avatar blob field and see if this improves performance.
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