Speed up rendering by caching images and not context

[nboisteault]

I think rendering could be speeded up by caching generated images and not serialized context files. In extra bonus we could then use better image compression than QGIS which has to compress on the fly.

[rldhont]

Images are cached if it's defined in configuration.

Can you be more explicit in the type of caching you'd like:

• client/web cache
• server side cache

[nboisteault]

I mean server side cache. I see files like : /lizmap-web-client/cache/pnrlg/lizmap_pnr_lg/ABC_Enjeux_Faune/EPSG_3857/lizmap1/lizmap10/lizmap102/lizmap102a/lizmap_102ad/lizmap__4a3856edb956787be5830bf5b4ac779a.cache

It is serialized data files I guess.

[rldhont]

no it's image cache if you add .png or .jpeg at the end of the file you can open it as an image.

What are you waiting for ?

[nboisteault]

When I change to png, I have an invalid file. What I'd like to do is to compress more with pngcrush for example as I think QGIS doesn't compress at maximum level because it has to build image quickly.

[nboisteault]

I've commited https://github.com/3liz/lizmap-web-client/pull/348 to have better compression of png image in cache. To go further with optipng for example we'll need to make script which :

• unserialize .cache file
• write png file on disk
• compress with optipng or any other lossless compressor
• stream_get_contents the file
• serialize them and write .cache file
• delete temp png file

I didn't find a way to use optipng in php directly on the image stream. It seems possible with node.js http://php-hackers.com/p/papandreou/node-optipng