Parallelization

[jamiebuilds]

I'm going to break down my current understanding of how CSS blocks works (I think as long as I'm close enough it will work for explanation purposes)

• Find all the CSS Blocks files (recursively)
• Parse out all the selectors for the CSS Blocks files
• Create interfaces for every CSS Blocks file
• Transform CSS Blocks files(?)
• Find all the JS/HBS files that use CSS Blocks
• Parse out all the usages of CSS Blocks
• Replace them with the appropriate selectors
• Continue transforming JS/HBS files by whatever tool CSS Blocks is running inside

The problem with this design is that in expects to happen in a very specific order and to have all the information it needs before continuing. This means that you cannot parallelize the transformation of CSS Blocks files and JS/HBS files that use CSS Blocks.

In a large app where every component uses CSS Blocks, this will have a really noticeable performance impact, you'll be blocking the transformation of hundreds if not thousands of files on an effectively synchronous process.

So I would like to revisit the design of CSS Blocks to see if there are things that we can do so that JS/HBS files and CSS files can be transformed in parallel, even if it means we have to revisit JS/HBS files after the CSS is done.

• Transform CSS Blocks/JS/HBS in parallel
  • CSS Blocks
  • Parse out selectors
  • Create interfaces
  • Transform(?)
  • JS/HBS
  • Replace usages of CSS Blocks with "references" that can be optimized out later
  • Transform
• Optimizations after everything has been transformed
  • Validate CSS Blocks interfaces in JS/HBS
  • Optimize away references in JS/HBS with appropriate selectors

These references could be just strings that CSS Blocks is able to identify:

"css-blocks-ref:path/to/button.css:size(small)"

Or maybe something more complex than that. The point is that you could come back later on and map it to something that was calculated in parallel elsewhere.

/cc @devongovett

[milandimun]

@jamiebuilds is it still open? I could work on this.