lessc execution speed very slow

[westonruter]

I am attempting to compile a simple LESS file that @imports two additional simple CSS files. This is taking over 4 seconds! It seems that it should compile almost instantaneously. See also the following thread: "Lessc execution quite slow" http://groups.google.com/group/lesscss/browse_thread/thread/b9c0e10fe0278656/3301d1a420703fad

[cloudhead]

hmm, that's not normal — it takes 4 seconds to compile a 4000 sloc file on my machine. could you try running rake benchmark from the less folder? It shouldn't take more than 5-6 seconds.

[miracle2k]

We are using less in a Python website, have about 12 less files, and recompiling them all whenever there is a change takes up to 25 seconds. Not very nice to develop with.

I've hacked together a quick daemon mode which lets lessc take requests via a socket and send the compiled file back, so it needs to be run only once - this brings us down to 4 seconds.

The code is here: http://github.com/miracle2k/less It's not in any way something ready to be merged, but something along those lines could be considered for mainline.

[cloudhead]

There is definitely room for a lot of optimizations in the grammar. It's something I'd like to look into at some point. Treetop isn't the fastest parser (being a PEG parser written in ruby) — but I think, by carefully optimizing the grammar, I should be able to get it 2-3x faster.

[jankrcal]

For me, this is quite an issue as well, in our project we have a lot of source less files. Whenever there's a change in any of there files, we glue them together into one huge less file, which takes about 20 seconds to compile on a local machine and about 10 seconds on the server. Is there any other (significant) room for improvements apart from optimizing the grammar?

[cloudhead]

Well, if you're using the more plugin, it has built in caching now, so it won't recompile files which haven't changed. This is a huge performance boost in dev. If you have a different infrastructure, maybe you can implement something similar, where files are compiled only if they have changed.