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This is an automatically generated e-mail. To reply, visit:
<a href="http://git.reviewboard.kde.org/r/106042/">http://git.reviewboard.kde.org/r/106042/</a>
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<p style="margin-top: 0;">On August 20th, 2012, 10:46 p.m., <b>Matěj Laitl</b> wrote:</p>
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<a href="http://git.reviewboard.kde.org/r/106042/diff/4/?file=79206#file79206line71" style="color: black; font-weight: bold; text-decoration: underline;">src/core-impl/collections/nepomukcollection/NepomukConstructMetaJob.h</a>
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(Diff revision 4)
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<td colspan="2"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "></pre></td>
<td colspan="2"><pre style="font-size: 8pt; line-height: 140%; margin: 0; ">private:</pre></td>
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<td bgcolor="#c5ffc4" width="50%"><pre style="font-size: 8pt; line-height: 140%; margin: 0; "> <span class="n">QHash</span><span class="o"><</span><span class="n">QUrl</span><span class="p">,</span> <span class="n">Meta</span><span class="o">::</span><span class="n">TrackPtr</span><span class="o">></span> <span class="n">m_trackHash</span><span class="p">;</span></pre></td>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">This is an important design issue:
You either need MemoryCollection or all these hashes, but not both. I'm still not convinced that you cannot avoid MemoryCollection at all, but if you use it, don't duplicate MapChanger.</pre>
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<p>On August 22nd, 2012, 9:36 a.m., <b>Edward Hades Toroshchin</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">There are two issues here.
First, it would be much better to have implemented an own QueryMaker that would translate Amarok's queries to Nepomuk's queries.
This would, of course, render MemoryCollection unneeded. However, we did not go that way in this project, and you can ask me (or phalgun) personally, if you want to learn the reasons.
Second, we tried to rely on MemoryCollection, and it didn't go very well. Main reason is that it mostly checks uniqueness by the uniqueness of titles (or title+artist for albums). However, it doesn't do this very reliably (or I didn't understand how to use it correctly), so some quirks did creep out here and there. So, we switched to nepomuk-uid-uniqueness, handled by NepomukCollection.
TL;DR: this is quasi-temporary solution as it is, as we will move to NepomukQueryMaker eventually. So let's leave these hashes where they are.</pre>
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<p>On August 22nd, 2012, 10:05 a.m., <b>Matěj Laitl</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">> First, it would be much better to have implemented an own QueryMaker that would translate Amarok's queries to Nepomuk's queries.
Total agreement.
> Second, we tried to rely on MemoryCollection, and it didn't go very well. Main reason is that it mostly checks uniqueness by the uniqueness of titles (or title+artist for albums).
This is how MemoryCollection works. It is used for "dumb" back-ends that don't know tracks of an album etc.
> However, it doesn't do this very reliably (or I didn't understand how to use it correctly),
Well, it works as it is supposed to work. E.g. you should NOT find existing album (etc.) entities for new tracks you add to MemoryColleciton through MapChanger. You should return new instance every time (see IpodMeta::Track), MapChanger does the matching. Any matching you do yourself is completly unused.
> so some quirks did creep out here and there. So, we switched to nepomuk-uid-uniqueness, handled by NepomukCollection.
Has *no* effect at all, because the world sees the MemoryCollection maps, and it uses name-uniqueness. *No one* (apart from MapChanger for a short while) sees NepomukAlbum etc., and NepomukAlbum::tracks() is *never* called when using MapChanger. NepomukTrack is hidden behind MemoryMeta::Track. Test it!
> TL;DR: this is quasi-temporary solution as it is, as we will move to NepomukQueryMaker eventually. So let's leave these hashes where they are.
Understand that MemoryCollection is rather good temporary solution, but it is used incorrectly. (e.g. there's a lot of completely useless code)</pre>
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<p>On August 22nd, 2012, 10:17 a.m., <b>Edward Hades Toroshchin</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Again: we had used MemoryCollection as you describe and it didn't work well. I didn't want to dig into it (and I don't want to now).
(if you don't take my word for it, or want to dig into it, please checkout some older commits from phalgun's branch).
I understand how MemoryCollection works, and I understand that there is a certain effort duplication, as well as (some) wasted memory.
So, to summarize, there are two options: either accept this uncool temporary solution, or switch it back to a cool temporary solution that works worse. I don't see much sense in the latter, because it's still temporary solution, and (if we believe phalgun) promises to be quite a short-lived one.
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<p>On August 22nd, 2012, 10:26 a.m., <b>Matěj Laitl</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">> So, to summarize, there are two options: either accept this uncool temporary solution, or switch it back to a cool temporary solution that works worse.
The "cool temporary solution" *cannot*, by definition, work worse. Read my above comment again, all that additional code has *no visible effect*. How can I convince you? (do you see that all these hashes are used only for short while when the NepomukConstructMetaJob runs and then they're discarded?)
> I don't see much sense in the latter, because it's still temporary solution, and (if we believe phalgun) promises to be quite a short-lived one.
The "cool temporary solution" would be a couple of hundreds code lines less, witch nearly no effort. Worth it IMO.</pre>
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<p>On August 22nd, 2012, 10:58 a.m., <b>Edward Hades Toroshchin</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">You're talking theory, I'm talking practice. Been there, done it, gone away.
I'm just saying we shouldn't waste our time perfecting a _temporary_ solution. And it will amount to some time wasted, because we already wasted it once, trying to use MemoryCollection as you propose. Of course, we could have done this wrong.
If you still insist on reworking this, go ahead. I suggest you help phalgun on it then :)</pre>
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<p>On August 22nd, 2012, 10:59 a.m., <b>Edward Hades Toroshchin</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Also, you are abusing the term "by definition" :)</pre>
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<p>On August 23rd, 2012, 6:46 a.m., <b>Bart Cerneels</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Good thing there is good news w.r.t. nepomuk query speed: http://vhanda.in/blog/2012/08/faster-nepomuk-queries/
I suspect this was part of the need for MemoryQueryMaker use.
I'm leaning to believe Matej w.r.t. the code duplication. This comes from decent understanding of MemoryCollection (wrote part of it) but without reading NepomukCollection code, at least not the latest version, fully.
Pragmatically I would just merge this code, which is working and move to a full NepomukQueryMaker as soon as possible and if the performance is good enough. If that does not happen soon enough, code quality and maintainability (i.e. less complex code) is more important and regular use of MemoryQueryMaker should at least be attempted.</pre>
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<p>On August 24th, 2012, 4:54 a.m., <b>Phalgun Guduthur</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Though I agree that using an extra hashmap might result in code redundancy, it serves the purpose temporarily.
I would also prefer not restructuring it for now as I'm looking to write my own NepomukQueryMaker which executes queries on the fly instead of storing all the meta objects as it is being done now through MemoryCollection. </pre>
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<p>On August 24th, 2012, 9:20 a.m., <b>Matěj Laitl</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">> Though I agree that using an extra hashmap might result in code redundancy, it serves the purpose temporarily.
Do you guys (apart from Bart) actually read me? It serves no purpose, but if you're already working on NepomukQueryMaker, leave it.
This gives me an idea - why about merging the code into master only when NepomukQueryMaker is ready and MemoryCollection ditched? Reviewing new and ready code is much easier (and we'll spot more things) than reviewing bad -> good code.</pre>
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<p>On August 24th, 2012, 10:47 a.m., <b>Phalgun Guduthur</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">We wanted to maintain separate Nepomuk hashmaps to prevent duplicate Nepomukmeta objects.
But I'm now realizing that my Nepomuk meta objects apart from NepomukTrack, serve no purpose and I could have just as used Meta::Artist, Meta::Album etc with the same functionality. If that is indeed true, then I could remove the HashMaps.
I'll check this again in a few hours (don't have my laptop currently), and I'll change it according to what you said or give you an explanation as to why not.
Thanks again! </pre>
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<pre style="margin-left: 1em; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">> We wanted to maintain separate Nepomuk hashmaps to prevent duplicate Nepomukmeta objects.
>
> But I'm now realizing that my Nepomuk meta objects apart from NepomukTrack, serve no purpose and I could have just as used Meta::Artist, Meta::Album etc with the same functionality. If that is indeed true, then I could remove the HashMaps.
It is. However Meta::Artist is abstract, so you'll have to implement own subclass, but that can be very dumb, you may even copy large portions on IpodMeta::Artist etc. (IpodMeta::Album has some code dealing with cover images, you probably don't need it, just store album name, and album artist)
> I'll check this again in a few hours (don't have my laptop currently), and I'll change it according to what you said or give you an explanation as to why not.
>
> Thanks again!
Good then, you're welcome.</pre>
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<p>- Matěj</p>
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<p>On August 20th, 2012, 11:17 a.m., Phalgun Guduthur wrote:</p>
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<div>Review request for Amarok, Edward Hades Toroshchin, Vishesh Handa, and Matěj Laitl.</div>
<div>By Phalgun Guduthur.</div>
<p style="color: grey;"><i>Updated Aug. 20, 2012, 11:17 a.m.</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<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;">Nepomuk plugin for Amarok.
Almost all of the code changes can be found in src/core-impl/collections/nepomukcollection/*
And a minor change in src/core-impl/collections/support/MemoryMeta.cpp
Code builds and after Nepomuk plugin is activated in the "Settings" dialog, Nepomuk Plugin comes into play and queries all the tracks in your machine. The query is not 'that' fast and might take several seconds depending on the number of tracks in your box.
IMPORTANT : Make sure Nepomuk is enabled if you want to give the plugin a spin. </pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Testing </h1>
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<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;">Minimal. Plan to spend the remaining time on testing the plugin. </pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>src/core-impl/collections/CMakeLists.txt <span style="color: grey">(c78b920)</span></li>
<li>src/core-impl/collections/nepomukcollection/CMakeLists.txt <span style="color: grey">(7cfd4b0)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukAlbum.h <span style="color: grey">(185c25a)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukAlbum.cpp <span style="color: grey">(6a09a1b)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukArtist.h <span style="color: grey">(6fcedf3)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukArtist.cpp <span style="color: grey">(13ddf01)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukCollection.h <span style="color: grey">(928b145)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukCollection.cpp <span style="color: grey">(cb185e8)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukCollectionFactory.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukCollectionFactory.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukComposer.h <span style="color: grey">(1b11325)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukComposer.cpp <span style="color: grey">(f21251e)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukConstructMetaJob.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukConstructMetaJob.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukGenre.h <span style="color: grey">(ce0e3b7)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukGenre.cpp <span style="color: grey">(945074c)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukQueryMaker.h <span style="color: grey">(50067de)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukQueryMaker.cpp <span style="color: grey">(33163ea)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukRegistry.h <span style="color: grey">(a21347e)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukRegistry.cpp <span style="color: grey">(8afa199)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukTrack.h <span style="color: grey">(77dd8c7)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukTrack.cpp <span style="color: grey">(7db01cf)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukYear.h <span style="color: grey">(504cbe2)</span></li>
<li>src/core-impl/collections/nepomukcollection/NepomukYear.cpp <span style="color: grey">(1f13de0)</span></li>
<li>src/core-impl/collections/nepomukcollection/amarok_collection-nepomukcollection.desktop <span style="color: grey">(1ac9f02)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukAlbum.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukAlbum.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukArtist.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukArtist.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukComposer.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukComposer.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukGenre.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukGenre.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukLabel.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukLabel.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukTrack.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukTrack.cpp <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukYear.h <span style="color: grey">(PRE-CREATION)</span></li>
<li>src/core-impl/collections/nepomukcollection/meta/NepomukYear.cpp <span style="color: grey">(PRE-CREATION)</span></li>
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<p><a href="http://git.reviewboard.kde.org/r/106042/diff/" style="margin-left: 3em;">View Diff</a></p>
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