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[[!template id=gitbranch branch=smcv/ready/depends-exact author="[[smcv]]"]]

I'm still trying to optimize ikiwiki for a site using [[plugins/contrib/album]], and checking which pages depend on which pages is still taking too long. Here's another go at fixing that, using [[Will]]'s suggestion from [[todo/should_optimise_pagespecs]]:

A hash, by itself, is not optimal because the dependency list holds two things: page names and page specs. The hash would work well for the page names, but you'll still need to iterate through the page specs. I was thinking of keeping a list and a hash. You use the list for pagespecs and the hash for individual page names. To make this work you need to adjust the API so it knows which you're adding. -- [[Will]]

If you have P pages and refresh after changing C of them, where an average page has E dependencies on exact page names and D other dependencies, this branch should drop the complexity of checking dependencies from O(P * (D+E) * C) to O(C + PE + PD*C). Pages that use inline or map have a large value for E (e.g. one per inlined page) and a small value for D (e.g. one per inline).

Benchmarking:

Test 1: a wiki with about 3500 pages and 3500 photos, and a change that touches about 350 pages and 350 photos

Test 2: the docwiki (about 700 objects not excluded by docwiki.setup, mostly pages), docwiki.setup modified to turn off verbose, and a change that touches the 98 pages of plugins/*.mdwn

In both tests I rebuilt the wiki with the target ikiwiki version, then touched the appropriate pages and refreshed.

Results of test 1: without this branch it took around 5:45 to rebuild and around 5:45 again to refresh (so rebuilding 10% of the pages, then deciding that most of the remaining 90% didn't need to change, took about as long as rebuilding everything). With this branch it took 5:47 to rebuild and 1:16 to refresh.

Results of test 2: rebuilding took 14.11s without, 13.96s with; refreshing three times took 7.29/7.40/7.37s without, 6.62/6.56/6.63s with.

(This benchmarking was actually done with my [[plugins/contrib/album]] branch, since that's what the huge wiki needs; that branch doesn't alter core code beyond the ready/depends-exact branch point, so the results should be equally valid.)

--[[smcv]]