Re: [Libosmscout-development] osmscout-server

[Lukáš K. <luk...@ce...>]

Nice to see such project! It can help to integrate osm scout to tile based 
applications like KDE Marble or GPX Viewer and make it usable offline...
Or it can be used for creating web map service based on osmscout renderer.

But as developer of OSM Scout for Sailfish, I am little bit skeptic for usage 
on mobile device. You know, I am not impartial :-)

I would like to see web based style editor for example. It may be used for 
creating custom map styles withnout installing library locally. 
And all deployed on Raspberry PI, it would be awesome...

Of course, keep doing what is fun for you,
Lukas

Dne pondělí 19. září 2016 17:13:49 CEST rinigus napsal(a):
> Dear libosmscout developers:
> 
> I'd like to introduce a small libosmscout-based server that, in future, can
> be used as a drop-in replacement for tile (and other relevant info) server
> by programs that require such servers.
> 
> Rationale: We are missing a native application for offline navigation and
> map viewing/exploring in Sailfish. At present, there are several
> applications (at least 4) that are in part working to implement the
> functionality. Out of them, some have focused on GUI and getting the best
> support from online provided maps, and some have worked on all aspects
> (backend and frontend, OSM Scout for Sailfish). The amount of developers is
> very limited and through this server I would like to contribute by exposing
> libosmscout backend to the frontends that have been focused on GUI.
> 
> What can it do: At present, the server registers a port and waits for HTTP
> requests on it. So far, it knows how to serve tiles using slippy map
> notation with small extensions. It can accept multiple requests
> simultaneously and process them in parallel. This is done by
> mutex-protecting calls to the database (
> https://github.com/rinigus/osmscout-server/blob/master/src/dbmaster.cpp#L97)
> and
> drawing in parallel. On PC, it can load all CPUs without any problems when
> accessed via modRana. Haven't tested multithreading in Sailfish yet due to
> single-threaded access used in the app that I used for testing (Poor Maps).
> 
> Even when accessed via single thread, the server can feed the tile images
> in PNG fomat with reasonable speed on mobile device. Through the extended
> slippy map URL scheme, I can increase served tile sizes to optimize for
> best performance. By using tile-oriented GUIs, all caching of generated
> images has been taking care of and reducing the load on CPU further.
> 
> At present, the memory footprint was about 220-260MB RSS on mobile device.
> I presume that it would be higher when multiple pixmaps are generated in
> parallel.
> 
> Implementation: Please consider current implementation as a proof of
> concept.
> 
> As an HTTP server API, I used QtWebApp which, as suggested by the lib
> author, is incorporated into the code. This lib was selected since it is
> simple to perform multi-threaded processing and, as majority of Sailfish
> applications, it uses Qt. This choice can be altered if someone would like
> to use some other API that has similar properties.
> 
> To compile, you need libosmscout libraries installed in the system. For
> Sailfish, I made a simple packaging scripts to install libosmscout (qt
> variant) and its development headers. That prevents distribution via
> official store, but allows simpler development. There are other channels
> that can be used for distribution and I intend to use them instead of the
> store.
> 
> Further development: I plan to develop 2 interfaces - CLI and QML. QML
> interface should allow to alter configuration settings (port, bound
> interface, font size, ...) via GUI and simplify starting/stopping the
> server on mobile device. CLI would read settings from configuration file
> and run in terminal. That would allow using it for testing libosmscout on
> PC.
> 
> License: LGPL
> URL: https://github.com/rinigus/osmscout-server
> 
> As usual, everyone are welcome to join. Would be interesting to know
> whether such project is of any interest to this community before I put a
> lot of effort into it.
> 
> Best,
> 
> rinigus