KDE PIM/Akonadi

Akonadi TODO

The following list contains the things which need to be done for Akonadi.

Note: The person noted in the "Contact" column is not necessarily the one implementing that feature, but the one who can tell you what to do and how to help, i.e. you can also contribute to those tasks ;-)

Core

4.1

Urgent tasks that need to be finished for the KDE 4.1 release (May 19th):

Status	Item	Description	Contact
DONE	Item streaming in ItemSync/ResourceBase	As discussed in Osnabrueck	<Tom/Volker>
DONE	Payload serialization format versioning	see below [email protected]	<Tobias>
DONE	API for additional item parts	As discussed in Osnabruck	<Volker/Tobias>
DONE	Infrastructure for showing additional dialogs from agents/resources	As discussed in Osnabrueck	<Tom>
DONE	Allow to limit ItemFetchJob to current cache content	Prevents search index feeder agents from downloading all remote data	Volker <[email protected]>
DONE	Fix API for item/collection modifications	See Osnabrueck meeting notes for details	Volker <[email protected]>
DONE	Plugin Versioning	For serializer plugins, also check using Qt plugin stuff instead of the libkdepim plugin framework	Tobias <[email protected]>
DONE	Tray app	small app to control the server and have a something that can report errors	Toma <[email protected]>
DONE	Backup support	Dump & Restore database contents, also useful when upgrading to a newer database version	<[email protected]>

Scheduled for 4.2

That's the stuff we want to have in 4.2, very roughly ordered by priority.

Status	Item	Description	Contact
TO DO	Better error detection	Sane error message when the server is not running or if there is some other problem communicating with it. This is a must-have for 4.2 when planning to migrate the resources.	[mailto: <>]
IN PROGRESS	KResource migration tool	For KABC and KCal resources, setting up Akonadi <-> KResource bridges where needed	<Volker>
IN PROGRESS	KResource bridges	Subresource support still has to be done	<Kevin>
TO DO	Complete iCal resource	error handling, robustness, legacy formats, etc.	[mailto: <>]
TO DO	Complete vCard resource	same as iCal	[mailto: <>]
IN PROGRESS	Item size	Needed by Mailody	<[email protected]>
IN PROGRESS	Finish collection model/view	see below	<[email protected]>
IN PROGRESS	Collection statistics for sub-trees	Provide a CollectionStatus object covering the full sub-tree in the model, allowing accumulated unread counts etc.	<Thomas>
TO DO	Batch jobs for modifying/deleting collections/items	it would be great to have jobs which perform operations on several entities in one sitting (a use-case: mark all as read).	[mailto: <>]
TO DO	Batch job to retrieve a set of items from Akonadi	Those items don't belong to the same collection, rather they are located in different collections	[mailto: <>]
TO DO	CollectionFetchJob/ItemFetchJob should be able to retrieve entities by remote id/mimetype	This is problematic with change notifications, as they have to know about the filtering with the \Seen flag as well. This type of filtering would be possible with full Nepomuk interface though. We don't want yet another query language here. The plan is to fix the nepomuk agent and use that as semi-public interface for now.	[mailto: <>]
TO DO	ResourceBase::collectionsRetrievalDone is missing	I'm working around by calling collectionsRetrievedIncremental() with empty collection lists	[mailto: <>]
IN PROGRESS	LINK/UNLINK commands	Managing item references in virtual collections	Volker <[email protected]>

Post 4.2

This stuff is currently not considered for 4.2 due to lack of resources. Of course it will be added nevertheless if someone implements it. The list is completely unsorted.

Status	Item	Description	Contact
TO DO	Error reporting	Akonadi::Job basically has only one error code: Unknown	<Tobias>
IN PROGRESS	Akonadi Artwork	Icon for the tray app	Toma <[email protected]>
TO DO	Nepomuk integration	Generic Item tag/rate/comment, etc.	<Tom>
TO DO	Account creation wizard	as discussed in Berlin, see below	[mailto: <>]
TO DO	Sync collection tree after creating setting up a resource	see AgentInstanceCreateJob	[mailto: <>]
TO DO	Support standard commands for QUndo framework		[mailto: <>]
TO DO	Conflict detection in resources	See Osnabrueck meeting notes for details	[mailto: <>]
IN PROGRESS	Action framework	see below	Volker <[email protected]>
TO DO	Solid integration	Switch online/offline state in ResourceBase automatically	[mailto: <>]
TO DO	Make unittests work without destroying the production database		[mailto: <>]
IN PROGRESS	Fix API docs	The libakonadi move as well as the huge API changes following it broke lots of the docs technical and content-wise, see below	<Tobias>
TO DO	Filesystem Backend	Store content data in files instead of the database, transfer filehandles instead of data to the client	[mailto: <>]
TO DO	Migration	Data and settings from pre-Akonadi times, see below	[mailto: <>]
TO DO	Remote Search	Delegating searches to resources, see below	[mailto: <>]
TO DO	Extended notifications	Item change notification do not yet include their source collections (real and virtual)	[mailto: <>]
TO DO	Alternative for Akonadi::ResourceBase	Not using the scheduler to avoid the serialization of operations, see RSS resource. (This will get very complicated. Maybe use a proxy ResourceBase for this, which is thread-pooled?)	[mailto: <>]
TO DO	Collection parameter for Monitor::itemChanged() and Monitor::itemRemoved()	If the item resides in several collections (normal + virtual collections) then emit those signals for each collection. Adding this would mean changing it in many places (Monitor, Observer, ...), this is lots of work but probably the right thing to do. Related to virtual collections, since with them, items can be in multiple collections. Better wait until the Nepomuk stuff is finished?	[mailto: <>]

Supported Types

Overview on the current state of support for various types:

Type	Serializer	Multipart Support	Models	Views	Resources	Notes
Email	yes	partial	MessageModel, MessageCollectionModel, threading proxy model	?	maildir, IMAP	threading agent
News	yes (1)	partial (1)	(1)	(1)	NNTP
Contact	yes	no	ContactModel	-	vCard, facebook, KRes
Events	yes	no	EventModel	-	iCal, KRes
Notes	no	no	-	-	-	not started yet
Feeds	yes	no	Feeds, Items	?	OPML	GSoC in playground/pim
Bookmarks	yes	no	-	-	local bookmarks, del.icio.us

(1) see Email

Mail specific extensions

Status	Item	Description	Contact
TO DO	Extend Message Model	Add all required columns, save/restore layout, flag delegate, configurable columns, etc.	[mailto: <>]
TO DO	Share mail flag code	Standard actions, standard flag enum/constants, Nepomuk interaction	[mailto: <>]
TO DO	Extend ENVELOPE	Add more information to the envelope payload part in the serializer plugin, eg. trheading information is missing	[mailto: <>]
TO DO	Fix/finish threading		[mailto: <>]

Event/Todo/Journal specific extensions

Status	Item	Description	Contact
TO DO	Todo proxy model	See KOrganizers To-Do view	<Bruno?>
IN PROGRESS	Subtype identification	See discussion on kde-pim mailinglist	<Kevin?>
TO DO	Agenda view	KOrganizer agenda view based on Akonadi	<Bruno?>
TO DO	Month view	KOrganizer month view based on Akonadi	<Bruno?>
TO DO	Timeline view	KOrganizer timeline view based on Akonadi	[mailto: <>]

Resources, Agents and others

Status	Item	Description	Contact
IN PROGRESS	KResource Akonadi bridge	for applications using KCal or KABC	Kevin <[email protected]>
IN PROGRESS	Akonadi KResource bridge	for data accessed through KCal or KABC resources	Kevin <[email protected]>
TO DO	Expire Agent		[mailto: <>]
TO DO	MBOX Resource		<Thomas>
TO DO	Extend IMAP Resource		[mailto: <>]
TO DO	POP3 Resource		<Thomas>
IN PROGRESS	RSS Resource	GSoC in playground/pim (Details)	<Dmitry>
TO DO	Filter Agent		[mailto: <>]
TO DO	Search		[mailto: <>]
TO DO	Filter Rule GUI	Used by filters and searches	[mailto: <>]

Resource status overview (this should list all resources existing in KDE3 or already under development for Akonadi):

Resource	Retrieve Collections	Retrieve Items	Change Collections	Change Items	Configuration	Notes
iCal	yes (4)	yes (1) (2)	no	yes (5)	yes	does not yet watch for file changes
vCard	yes (4)	yes (1) (2)	no	?	yes	does not yet watch for file changes
maildir	yes (1) (4)	yes (1) (2)	?	?	yes
mbox	no	no	no	no	no	not started yet, code exists in KMail
IMAP	yes (1) (4)?	yes (1) (2)	no	no	no	code exists in kio_imap4 and Mailody, support for extensions: quota, ACL, annotations missing, what about Kolab and Scalix?
POP3	no	no	no	no	no	not started yet,code exists in kio_pop3
NNTP	yes (4)	yes (2)	n/a	n/a	yes	Needs support for local collection names and collection hierarchy
Local Bookmarks	?	?	?	?	(3)	Code in akonadi/resources
OpenChange	?	?	?	?	?	Code in akonadi/resources
Facebook	?	?	?	?	?	Code in playground/pim
del.icio.us	?	?	?	yes	no	Code in playground/pim
KABC	no	yes	no	yes	yes
KCal	no	yes	no	yes	yes

(1) only full sync supported currently, need optimization (2) does not yet honor cache policy (3) still relies on QSettings for configuration and/or doesn't provide configuration over D-Bus (4) does not yet provide correct access control settings (5) only adding new items, not changing existing ones

Akonadi Braindump

Ideas/notes etc. on various open issues in Akonadi.

Akonadi Standard Actions

Idea: Have something like KStandardAction for Akonadi that not only includes the representation of the action but also its state management and the actual operations. Like libakonadi that should be splitted into a generic, type-independent part and be extensible for type-specific actions. This will enable code sharing among many applications and guarantee consistent actions everywhere.

State management: watch selection models of a collection and/or item model.

Use KXMLGUI for context menus in standard views to allow easy extensibility with custom actions.

Generic actions:

new collection [done]
new virtual collection
delete collection [done for single selection]
copy collection [done]
cut collection
paste collection [done]
synchronize collection [done for single selection]
synchronize resource
synchronize everything
show collection properties dialog [done]
delete item(s) [done]
copy item(s) [done]
cut item(s)
paste item(s) [done]
paste native data
tag item(s)
comment item
rate item(s)
configure resource
add resource? (would need a type parameter, etc.)
delete resource
manage local subscriptions [done]
move to submenu
copy to submenu

The list is definitely long enough to make this worthwhile.

Collection Model / Collection View

Ideas/missing features/bugs of the collection model/view:

Enable/disable status columns
Show status after the name (see KMail)
Size column
Save/restore layout
Custom collection icons (see KMail, also needed for resource defined special folders (eg. Inbox)
Status tooltips (see KMail in 3.5.9)
Quick search
Favorite folder view as proxy model on top of the normal collection model (FlatCollectionProxyModel might be helpful for there)
Accumulated statistics (unread, total, size)
Fix dnd: move/copy/cancel menu always shows up and never has any effect

Compatibility

Notes on how to keep long-term protocol, source and binary compatibility.

~~Detect server version in Akonadi::Session, might be useful in case of protocol extensions/changes~~
What about database server version updates?
~~Versioning or any other kind of serialization format meta data, we'll need that in case of changes in serialization formats (see eg. Robert's compression patch where this is needed)~~
~~We currently use 32 bit ids, probably hard to change later on, is that enough?~~
~~Plugin versioning~~

Resource API issues

Notes/ideas/complaints about the Akonadi::ResourceBase API:

Extremely error prone:
- Scheduler dead-locks when a requested operation is not correctly announced as finished, esp. a problem in error cases.
- Using the result methods multiple times or when not requested asserts
~~Item streaming is missing, requiring all data to be in memory at once~~
Non-incremental updates need to know the results of ItemSync to not have to provide all data, even for already existing/unchanged items.

API / BC issues

Smaller stuff that should be fixed before the ABI freeze and is not yet listed above:

Cleanup the D-Bus format used by NotificationMessage
No mentioning of "IMAP" in the public API, we are not using IMAP
Naming and installed location of libraries, headers and executables (see discussion on kde-pim ML)
~~Payload part labels are QStrings, attribute types are QByteArray~~

Deployment issues

Multiple access: Should multiple Akonadi instances' mysqlds access a single set of data files the mysql will likely corrupt the data. This can happen in any NFS+YP installation where users can log onto any machine and access shared homes. MySQL relies on filesystem locking to prevent multiple access. MySQL multiple instance docu.
InnoDB tables should not be used on NFS.
NFS speed: MySQL documentation recommends against locating its data files on network shares.
AppArmor: Distros' AppArmor profiles prevent MySQL from writing outside its defined data directory (usually /var/lib/mysql). This is a problem at least with *buntu and openSUSE. These will need to be adapted. It is possible to daisy-chain profiles so that MySQL started by Akonadi receives a different profile to MySQL running standalone. An empty profile has all rights. Another possibility is to adapt the general MySQL profile so it can write to ${XDG_DATA_HOME}/akonadi(usually ${HOME/}.local/share/akonadi). Both support for profile chaining and ${HOME} may depend on the version of AppArmor installed. What about SELinux?
Backup: MySQL data files should not be backed up without telling the mysqld process, otherwise a corrupt backup will be made. LOCK TABLES and FLUSH TABLES at the least. A dump can be made or mysqlhotbackup may be used in some circumstances. We should consider sysadmins' backup techniques when planning/promoting Akonadi, as a simple rsync cronjob with running Akonadi will not work. MySQL backup advice.

Account Creation Wizard

Notes on the resource configuration wizard discussion.

WizardBase class
Wizard discovery via .desktop files
A wizard can configure multiple resources (eg. IMAP + LDAP for Kolab) and non-resources (mailtransport)
Optionally hide resources completely covered by wizards in the Add Account dialog
List wizards in the Add Account dialog
Store Account -> Resources information to offer deletion of depending resources

PostgreSQL datastore support

First review of the akonadi code reveals PGSQL Qt driver is already supported, but the code is not totally ready for it. Some first reading comments about where to patch for supporting PostgreSQL too:

akonadi/server/src/storage/dbinitializer.cpp

line 201..., ALTER TABLE ADD [UNIQUE] INDEX syntax is MySQL only, better use the common one CREATE [UNIQUE] INDEX ... one [done with revision 789899]
line 303, QString DbInitializer::sqlType(const QString & type), LONGBLOB is the MySQL type, PostgreSQL will use BYTEA.
line 362, qFatal("Implement index support for your database!");

 mysql: SHOW INDEXES FROM %1
 pgsql: SELECT c2.relname, i.indisprimary, i.indisunique, i.indisclustered, i.indisvalid, pg_catalog.pg_get_indexdef(i.indexrelid, 0, true), c2.reltablespace
 FROM pg_catalog.pg_class c, pg_catalog.pg_class c2, pg_catalog.pg_index i
 WHERE c.oid = '16713' AND c.oid = i.indrelid AND i.indexrelid = c2.oid
 ORDER BY i.indisprimary DESC, i.indisunique DESC, c2.relname
 
    relname    | indisprimary | indisunique | indisclustered | indisvalid |                       pg_get_indexdef                        | reltablespace
 --------------+--------------+-------------+----------------+------------+--------------------------------------------------------------+---------------
  foo_pkey     | t            | t           | f              | t          | CREATE UNIQUE INDEX foo_pkey ON foo USING btree (id)         |             0
  foo_time_key | f            | t           | f              | t          | CREATE UNIQUE INDEX foo_time_key ON foo USING btree ("time") |             0
 (2 lignes)

akonadi/server/src/storage/datastore.cpp

line 700, qint64 DataStore::highestPimItemId() const, seems wrong for a concurrent program (SELECT MAX(col) FROM table; is not reliable if another thread is inserting at the same time) : check the callers
line 794, qint64 DataStore::lastInsertId( const QSqlQuery & query ), PostgreSQL doesn't provide concurrent-bogus last_insert_id, but from 8.2 accepts the syntax INSERT INTO ... RETURNING col1, col2, ...;
line 806, QString DataStore::dateTimeFromQDateTime( const QDateTime & dateTime ), use PostgreSQL to_char() formatting function for date rather than having Qt do it

Documentation

Avoid examples using KJob::exec() due to its problematic side-effects.
Examples in the ItemCreateJob docs (and maybe others) operate on items in the root collection which does not work at all
Resurrect the server API docs

Migration of pre-Akonadi data and settings

KCal/KABC
- switch KRes resources to Akonadi KRes compat resources, use KRes Akonadi compat resource, basically injecting Akonadi inbetween
- Replace Akonadi KRes compat resources with their ported equivalent
- Application side does not need migration code, "only" port to Akonadi
KMail
- Should migrate to one resource per account + one for previous local folders
- Problem: local folders are mixed mbox/maildir
  - Dedicated KMail compat resource?
  - Convert everything to maildir first?
- Flags are stored in proprietary binary format
KNode
- Migrate every account to NNTP resource
- Local flags should be preserved, stored in proprietary binary format
- Local subscription state should be preserved (where is that stored?)
- Local folders using MBOX format + proprietary binary index
Akregator

Search

Delegation to resources still completely missing
- Requires query transformation
- Requires management for live searches
- Requires the ability to report search results (needs protocol extension)
Query language still undecided, current options: XESAM, SPARQL
Backend still undecided, current options: XESAM, Nepomuk

KMail Breakdown Plan

The current plan is to put some parts of KMail into a stand-alone library, independent of KMail. This increases code reuse (for example, the message composer could be shared with Mailody) and makes the code a lot easier to maintain and to port to Akonadi.

Status	Item	Description	Contact
TO DO	Bodypart formatters		[mailto: <>]
TO DO	Reader Window		[mailto: <>]
TO DO	Composer: Editor		[mailto: <>]
TO DO	Composer: Message Composer		[mailto: <>]
TO DO	Composer: GUI Window		[mailto: <>]
TO DO	Queue Manager for mailtransport		[mailto: <>]
TO DO	Templates: Core		[mailto: <>]
TO DO	Templates: GUI		[mailto: <>]
TO DO	Port KMCommands		[mailto: <>]
TO DO	Port away from KMMessage and KMFolder* everywhere it is left	An idea might be: wrap KMMsgBase/KMMessage inside a reference counted Message class. Insulate everything else from it by wrapper functions. KMFolder should be easier...	[mailto: <>]
TO DO	Migration application for index and other config		[mailto: <>]
TO DO	Port MDNs		[mailto: <>]

The Road to World Domination

Sort of related so the stuff above but with a scope for all of KDE PIM and beyond.

Status	Item	Description	Contact
TO DO	Share identity config GUI parts	eg. the signature configuration widget	[mailto: <>]
TO DO	Mailtransport Agent	Global shared outbox, central mail sending instance	[mailto: <>]
TO DO	Recently sent to support in mailtransport	related to above, based on Akonadi/Nepomuk	[mailto: <>]
TO DO	Composer engine	Shared stuff for KMail/KNode/Mailody: Crypto, editor, editor actions, attachment model, message assembly, etc.	[mailto: <>]

Akonadi FAQ

Where do I find the Akonadi config files?

~/.config/akonadi/

Where does Akonadi store my data?

~/.local/share/akonadi/

Which DBMS does Akonadi use?

So far only MySQL. There is some work on PostgreSQL support going on though. Basically, every database that is supported by QtSQL can be used, requiring minimal changes in the code at most. However, not all of them provide the features needed by Akonadi (see next two questions).

Why not use sqlite?

We tried. Really. It can't handle the concurrent access very well, in the best case this means very slow operations, but we've also seen deadlocks and failing transactions. Once that's fixed in sqlite, adjusting Akonadi to use it again instead of MySQL is no problem.

Why not use MySQL/Embedded?

We tried that as well, there are two reasons for not using it: No support for the InnoDB engine (which we need for transaction support) and poor availability (only OpenSUSE provided usable packages, needed a patched QSQL driver).

Do I need a running MySQL server?

No. Akonadi starts its own local MySQL server (unless configured otherwise, see next question). All you need is having the 'mysqld' binary installed at runtime (usually found in the mysql-server package of your distribution).

Can Akonadi use a normal MySQL server running on my system?

Yes, it can. You find the corresponding settings in ~/.config/akonadi/akonadiserverrc.

I don't like a database server because of backups/running on NFS/etc.

See section "Deployment Issues" above, we are aware of that and working on it. Some of these, like backup/restore are already implemented. But please be aware that most of this issues also existed before (eg. with KMail's custom binary indexes).

Can a single Akonadi instance be used by multiple users?

No. There has to be one Akonadi server instance per user. However, it is possible to use a shared database server.

Can I access the Akonadi server on a remote machine?

No. Akonadi is not a groupware server. It's a local cache only.

I have an unknown error 255 when running akonadictl

Distributions using Apparmor require you to run aa-complain mysqld with root privileges then reload apparmor.

I get a "DB error: 'Could not open required defaults file: /home/$username/.local/share/akonadi//mysql.conf"

Although you probably don't have an apparmor in your processlist, you are still using it, run aa-complain mysqld and try again.

What's the difference to EDS?

EDS is limited to contacts and calendar data, Akonadi is type-independent. Especially, Akonadi is designed to also handle high-volume data such as email. Akonadi and EDS also differ largely in their access protocol on the technical level (Corba/D-Bus vs. local socket with IMAP-like protocol/D-Bus) as well as one the protocol level (type specific vs. generic).