speeding up the build of variants

[FAMILIAR-project]

FAMILIAR-project/varylatex#7

there are some discussions here and there: https://tex.stackexchange.com/questions/273997/incremental-build-of-large-document
https://tex.stackexchange.com/questions/8791/speeding-up-latex-compilation
the "draft" trick or "includeonly" is quite interesting

[c-a-m-o]

Performance improved in commit fe19e7d
It may be difficult to use \includeonly in the example because the included files are added using \input (the difference seems to be that \input is the only one that does not add a page break) instead of \include.
The improvement that could be made is adding the -interaction=batchmodeoption to pdflatex. It prevents interruptions thus making the compilation faster.
The downside of this is that we can no longer use latexmk but another upside of this is that we only have to generate the bibliography once for all the compilations.
For the example document, we got from about 1.2s to 0.29s on average for each pdf generation.

[FAMILIAR-project]

wow impressive! thanks.

maybe we should think about providing some options to varylatex for customizing the latex command(s) to use...
but by default I like to have a batchmode to speed up everything ;)

another downside of batchmode is that maybe some variants of the LaTeX don't compile and we won't detect them...
but we can trade safety for performance ;)

can you measure the time it takes to compile and store the value in the CSV for each variant #3? It can be interesting at some points.

there is also the package "draft" that does not depict figures in the PDF... can save some time as well.
I have also read discussions about compressing the quality of images just to speed up the compilation. It seem specific to some cases (like big PhD manuscripts), but why not having such a preprocess (as an option of varylatex) if it's worth.

In general, we should assess our speed improvements on various cases, beyond FSE one, but it's definitely future work.
At the end we will provide a default "mode" of varylatex that is the best for most of the cases.

[FAMILIAR-project]

https://www.systutorials.com/docs/linux/man/1-rubber/
not sure it's the most up-to-date system

anyway, there is a --cache option (maybe interesting)
and a --only option: we can envision to compile what's "common" once and for all, and then the variable part...
it's much more advanced use case/idea, will see if we address it in the future

edit: https://github.com/petrhosek/rubber