'Re: Review Request 112417: FIX: 283022 - Performance with large feed (6000 items) very poor'

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List:       amarok-devel
Subject:    Re: Review Request 112417: FIX: 283022 - Performance with large feed (6000 items) very poor
From:       "Mark Kretschmann" <kretschmann () kde ! org>
Date:       2013-09-08 9:20:07
Message-ID: 20130908092007.16045.56192 () vidsolbach ! de
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Ship it!

Looks good to me.

- Mark Kretschmann

On Aug. 31, 2013, 7:16 p.m., Frank Meerkoetter wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://git.reviewboard.kde.org/r/112417/
> -----------------------------------------------------------
> 
> (Updated Aug. 31, 2013, 7:16 p.m.)
> 
> 
> Review request for Amarok.
> 
> 
> Description
> -------
> 
> Using callgrind it was very visible that amarok is spending an enormous amount of \
> time to turn podcast episodes into tracks. 
> Initially i noticed that the PlaylistBrowserModel is calling \
> Playlist::tracks().count() while it should be calling Playlist::trackCount(). \
> Constructing a list of tracks is expensive for the case of Podcasts (as internally \
> podcast episodes are converted into tracks which get added to a new list). This \
> change already improved the situation a bit, but the UI was still sluggish. \
> Callgrind was still showing that we are turning episodes into tracks - over and \
> over. 
> To fix that i added a cache to the PodcastChannel. As long as the episodes haven't \
> changed, there is no point in constructing a new list of tracks each time tracks() \
> is called. 
> With that second fix the UI is now pretty useable.
> 
> 
> Diffs
> -----
> 
> src/browsers/playlistbrowser/PlaylistBrowserModel.cpp 281694a 
> src/core-impl/podcasts/sql/SqlPodcastMeta.h 02a18d3 
> src/core-impl/podcasts/sql/SqlPodcastMeta.cpp 20bcaff 
> 
> Diff: http://git.reviewboard.kde.org/r/112417/diff/
> 
> 
> Testing
> -------
> 
> Tested with http://www.justing.com.cn/justpod/justpod_ch.xml
> 
> 
> Thanks,
> 
> Frank Meerkoetter
> 
> 

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      This is an automatically generated e-mail. To reply, visit:
      <a href="http://git.reviewboard.kde.org/r/112417/">http://git.reviewboard.kde.org/r/112417/</a>
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 <p>Ship it!</p>

 <pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: \
-pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Looks good to me.</pre>  \
<br />

<p>- Mark</p>

<br />
<p>On August 31st, 2013, 7:16 p.m. UTC, Frank Meerkoetter wrote:</p>

<table bgcolor="#fefadf" width="100%" cellspacing="0" cellpadding="8" \
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<div>Review request for Amarok.</div>
<div>By Frank Meerkoetter.</div>

<p style="color: grey;"><i>Updated Aug. 31, 2013, 7:16 p.m.</i></p>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
 <table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" \
style="border: 1px solid #b8b5a0">  <tr>
  <td>
   <pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;">Using callgrind it was very visible that amarok is spending an enormous \
amount of time to turn podcast episodes into tracks.

Initially i noticed that the PlaylistBrowserModel is calling \
Playlist::tracks().count() while it should be calling Playlist::trackCount(). \
Constructing a list of tracks is expensive for the case of Podcasts (as internally \
podcast episodes are converted into tracks which get added to a new list). This \
change already improved the situation a bit, but the UI was still sluggish. Callgrind \
was still showing that we are turning episodes into tracks - over and over.

To fix that i added a cache to the PodcastChannel. As long as the episodes \
haven&#39;t changed, there is no point in constructing a new list of tracks each time \
tracks() is called.

With that second fix the UI is now pretty useable.</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
<table width="100%" bgcolor="#ffffff" cellspacing="0" cellpadding="10" style="border: \
1px solid #b8b5a0">  <tr>
  <td>
   <pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: \
-moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: \
break-word;">Tested with http://www.justing.com.cn/justpod/justpod_ch.xml</pre>  \
</td>  </tr>
</table>

<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
<ul style="margin-left: 3em; padding-left: 0;">

 <li>src/browsers/playlistbrowser/PlaylistBrowserModel.cpp <span style="color: \
grey">(281694a)</span></li>

 <li>src/core-impl/podcasts/sql/SqlPodcastMeta.h <span style="color: \
grey">(02a18d3)</span></li>

 <li>src/core-impl/podcasts/sql/SqlPodcastMeta.cpp <span style="color: \
grey">(20bcaff)</span></li>

</ul>

<p><a href="http://git.reviewboard.kde.org/r/112417/diff/" style="margin-left: \
3em;">View Diff</a></p>

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