From: Simon McVittie Date: Fri, 28 Aug 2009 00:13:43 +0000 (+0100) Subject: Explain my depends-exact branch X-Git-Tag: 3.1415926~38^2 X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=545029fe4bc11e828da193745c7555c1e8322768;p=ikiwiki.git Explain my depends-exact branch --- diff --git a/doc/todo/optimize_simple_dependencies.mdwn b/doc/todo/optimize_simple_dependencies.mdwn new file mode 100644 index 000000000..c3ccd5ad0 --- /dev/null +++ b/doc/todo/optimize_simple_dependencies.mdwn @@ -0,0 +1,48 @@ +[[!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 + P*E + P*D*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]]