Build performance

[zoetrope]

Summary

I'm building a book with a lot of pages with HonKit.
The build time increases exponentially with the number of pages.

• 40 pages -> 2 seconds
• 240 pages -> 60 seconds
• 1500 pages -> 1 hour

Step to reproduce

1. honkit build

I have not installed any plugins.

• HonKit version: 3.6.23

Expected results

I expect the build time increases in proportion to the number of pages.

Additional Information

I got the profile of honkit build with pprof-nodejs.
As a result, the following functions seem to be the bottlenecks.

• location.ts:areIdenticalPaths
• location.ts:flatten
• summaryArticle.ts:isExternal

[azu]

Nice research!

Yes, HonKit looks like do duplicated works in building.
Ideally, HonKit should build pages just one time.
However, current HonKit build a page multiply(encode page etc..)

We need to find suitable building way.

📝 Note
#243 is also related.

[Yilun-Sun]

@azu @zoetrope I will handle it this week, the PR is comming soon!