ManaPlus/docs/clientupdates.txt

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CLIENT AUTO-UPDATING
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UPDATING CLIENT DATA

For future clients we need to develop a way in which they can automatically
update to new data like for example new images, maps or item, being and skill
definitions. Here is described the sequence of actions that could implement
this functionality:

 1. Client loads initial core data for login screen (always included with
    release)
 2. Client logs on
 3. Server sends client list of required packages (maybe with versions)
 4. Client notices he doesn't have a certain package yet or is out of date
 5. Client requests from server .torrent files (or maybe at first just URL)
    from where to get the the missing packages
 6. Client downloads them and puts them in "data" directory (~/.mana/data on
    Linux, cause that's writable)
 7. Client loads the list of files server mentioned in VirtFS virtual
    filesystem
 8. Client tells server that it is up to date
 9. Client could load some common data like item definitions here
10. Server sends client player position and so on, game starts, client loads
    and unloads additional data like maps, tilesets, sprites, etc. on demand.


UPDATING THE CLIENT BINARY

Updates to the actual client binary are also being considered, especially on
the Windows operating system. While the plan is to move any specific game data
outside of the binary, sometimes an update to the binary will be required for
being able to play the game. Also especially Windows users are used to
automatic update checks for many applications (possibly because of the lack of
such a feature system-wide).

On Linux this would require either installing a statically linked binary
(which could still have some issues) or automatically compiling/installing
from source. Neither are very attractive options, and I (Hammerbear) would
prefer not to deal with automatic binary updates on Linux.

On Windows a binary can't be replaced while it is running, so probably a
separate update tool would need to be written that is run before the client
to check for updates to the client and possibly replaces the client before
running it.