KDE PIM in Randa

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The first release of KDE PIM based on KDE Frameworks 5 and Qt 5, which will be part of the KDE Applications 15.08 release, is getting closer and closer. Except for porting the entire suite from Qt 4 to Qt 5 the team also managed to fix many bugs, add a few new features and do some pretty big performance and memory optimizations. And we already have some new improvements and optimizations stacked in the development branch which will be released in December!

The biggest performance improvement is thanks to switching to a faster implementation of the communication protocol used by applications to talk to the Akonadi server. We also extended the protocol and we can now use it to send change notifications from the Akonadi server to clients much more effectively than previously. Additionally we started cleaning up API of our libraries and improving it in a way that allows for safer and more effective use. None of this was possible in the KDE 4 version of KDE PIM, where we promised API and ABI compatibility with previous releases. For now we decided not to give any such promises for several more releases, so that we can tune the API and functionality even more.

During Akademy the KDE PIM team had a very long session where we analyzed where the project currently stands and we created a vision of where we want KDE PIM to be in the future. We know what parts we want to focus on more now and which parts are less relevant to us. KDE PIM is a huge and rather complicated project, unfortunately the development team is very small and so we have to make the hard and painful decision to lay off some of the features and functionality in exchange for improvement in reliability and user experience of the core parts of the product.

In order to make these decisions the team is going to meet again in couple weeks in Randa alongside many other KDE contributors and projects and will spend there a whole week. During the sprint we want to take a close look at all the parts and evaluate what to do with them as well as plan how to proceed towards Akonadi Next – the new version of Akonadi, which has some major changes in architecture and overall design (see the Christian’s talk from Akademy about Akonadi Next).

However organizing such sprint is not easy and so we would like to ask for your support by donating to the KDE Sprints Fundraiser. Although the attendees cover some of the costs themselves, there are still expenses like travel and accommodation that need to be covered. This year the Fundraiser has been extended so that the collected money will also be used to support additional KDE sprints throughout the year.

KDE PIM Sprint Report

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The KDE PIM Sprint is over (unfortunately…I could do this every day :-)), so now it’s time for some recap of what has been done. I’ll try to cover the Akonadi side, and leave the rest up to others to cover their projects ;-)

Hacking time! (Photo by Martin Klapetek)

Hacking time! (Photo by Martin Klapetek)

Akonadi Server optimizations

We finished and reviewed Volker’s old branch with a big optimization of the database schema. On my computer it reduces size of the file with the largest table by 30% and it speeds up all queries on that database, because the WHERE condition now has to perform only integer comparision, instead of string.

This however means, that we have to migrate user’s database on start. During the migration it is not  be possible to use any Akonadi-based applications.  We improved the code so that the migration takes about 10 minutes on my computer (used to take 20 and more). I personally think that it’s acceptable “downtime” for a one-time migration, so after I finish testing the migration code on other backends, I’ll merge the branch to master and we’ll ship it with KDE 4.13.

There's always time for a beer!

There’s always time for a beer!

Server-side Search

When using online IMAP, only headers are in Akonadi, the body is downloaded on-demand when the message is opened in KMail. This means that Nepomuk can’t index these emails and thus can’t include them in search results. To fix this case, we want to make use of IMAP’s SEARCH functionality. We simply ask Nepomuk to search it’s database of indexed emails, at the same time we send IMAP server the same search query and then we just merge results and show them to users. Most of the infrastructure in Akonadi Server has been in place for a long time now, so I’ll just undust it, adopt it to our current needs and we should be good to go ;-)

Using Akonadi to store tags

Working on tags!I already mentioned this in a previous report: we want to cache tags in the Akonadi database and write them to storage backends if they support it (for instance as additional flags to emails on IMAP server, as CATEGORIES into events in iCal, etc.). Thanks to it it will be possible to share tags between multiple computers, yay! We just need to modify the Nepomuk libraries, so that when you ask Nepomuk for all data tagged with “Holiday”, Nepomuk can search it’s own database and also query Akonadi. Another benefit will be that filtering emails in KMail by tags will be much much faster, because the relation will be stored locally in Akonadi and we won’t have to talk to Nepomuk, which is very slow (mostly because of Virtuoso).

Storing conversations and threads in Akonadi

In his comment under my last blog, Till Adam said:

[…] KMail has the second best threading in the world, I think, second only to mutt because that is faster. […]

Why can’t KMail just have the very best threading in the world? Because right now it has to fetch the entire folder from Akonadi in order to be able to perform Subject comparision when building threads. That’s both very slow and CPU-intensive operation. So we thought: let’s store information about relations between emails in Akonadi, and when KMail asks for content of a folder, we give back only first few conversations just to fill the screen, and then fetch remaining conversations on demand when user scrolls down. This should make opening even massive folders superfast and should save a lot of memory, too.

Akonadi and KDE Frameworks

Hopefully David's code is more stable than his towers

Hopefully David’s code is more stable than his towers :)

The most-awaited discussion of the entire sprint was about KDE PIM and KDE Frameworks. When should we start? What has to be done? What can we use this opportunity for? From Akonadi point of view I want to do several things: remove deprecated API, change some API so that we use consistent naming and separate UI and non-UI stuff. Volker Krause suggested that we could move the client libraries into Akonadi repository with Akonadi server, so thatwe could share some of the code (protocol parsers for example), which I like, so we’ll go for that, too.

A bit unrelated, but still: the Akonadi server already compiles with Qt 5 for a while, so possibly during this development cycle we might switch to supporting only Qt 5 (and making use of all the C++11 awesomeness). There’s a little library that kdepimlibs link against, so we just build both Qt 4 and Qt 5 versions of it. Akonadi depends only on QtCore and QtDBus, so we only need distros to ship qt5-qtbase, which we believe most of them do by now.

Gmail resource

Vishesh and Àlex (Photo by Lukáš Tinkl)

Vishesh and Àlex (Photo by Lukáš Tinkl)

I’ve been promising this for ages, now I finally discussed this with others, got some input and can start hacking :-) Let’s see if I can do something before Christmas ;-) Gmail resource would store all your mails in one folder and would create virtual folders for each label and just link emails from the “All mails” folder into respective labels. This way the emails will share flags (read/unread), and you will even be able to manage the labels by linking or unlinking emails from label folders in KMail.

Here I’d like to thank everyone for coming to Brno – if was a lot of fun and great pleasure to see all of you again, and also thank Red Hat for letting us use the office. Looking forward to see you all again on FOSDEM, next sprint, Akademy or anywhere else :-)

KDE PIM Sprint Report: Day -2

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The KDE PIM sprint in Brno, Czech republic starts this Friday, but some KDE developers just could not wait and decided to come to Brno already on Monday to work with the Red Hat KDE Team. Some of the stuff we are hacking right now is PIM related, but we also want to use this few days to work on other projects that we are involved in, but that are not strictly related to KDE PIM.

So I’m just sitting right now in the office with Àlex Fiestas, David Edmundson, Vishesh Handa, Martin Klapetek and my colleagues Jan Grulich and Lukáš Tinkl. I’m waiting for Àlex to finish polishing his port of BlueDevil to BlueZ5, so that we can start hacking on KScreen – there are far too many bugs that need our attention and we’ve been neglecting KScreen quite a lot in the past few months. We want to fix the annoying crash in our KDED module, solve a regression that my bold attempt to fix an another crash in KDED caused and discuss the future direction of KScreen – me and Àlex have different opinions on where we should go next with KScreen so this is a great opportunity to find a common path :-)

Vishesh has been relentlessly working  on improving the semantic technologies in KDE and from what I’ve seen, it’s something to really look forward to ;-)

Yesterday, me and Vishesh discussed the possibility of using Akonadi for handling tags of PIM data (emails, contacts, events, …) and I implemented the feature into Akonadi and the Akonadi client libraries – only as a proof of concept though, I have no intention of shipping it at this point – much more work and discussion is needed about this. I also made further progress with implementing the IDLE extension to the Akonadi protocol. It allows the Akonadi server to send notifications about changes to clients using the Akonadi protocol, instead of D-Bus (performance++)

KDE hackers fighting bugs and bringing the awesome to our users

KDE hackers fighting bugs and bringing the awesome to our users

David Edmundson and Martin Klapetek have been working on creating Plasma theme for SDDM (a new display manager that for example Fedora intends to ship instead of KDM), and today they’ve been improving KPeople, the meta-contact library used by KDE Telepathy and that they will also integrate with KDE PIM.

My colleagues Lukáš Tinkl and Jan Grulich are working on plasma-nm, the new Plasma applet for network management in KDE.

More people will arrive to Brno tomorrow and the rest of KDE PIM sprint attendees will arrive during Friday, when the real sprint begins. Stay tuned for more news (not just) from the PIM world ;-)