[HTTPS-Everywhere] Startup time measurements in Chrome and Firefox

[Peter Eckersley]

On Fri, Jan 17, 2014 at 05:51:13PM -0800, Jacob Hoffman-Andrews wrote:
> 
> > On the other hand, the SQLite solution should be let us scale not just
> > to ~10K rulesets but if we're lucky to more like ~100K.
> 
> 
> This is one of the things I like about it. Also it reduces memory use,
> which is
> especially valuable on mobile.

That's probably true, although for optimal performance we may hope that
the whole .sqlite file is in the OS'es page cache; it looks like it
takes up about 20MB.  Perhaps on any OS where we think we aren't RAM
constrained we should just cat the file to /dev/null (or whatever the
local equivalent operation is) in the background.

Another downside is that the .sqlite file format roughly doubles the
size of our .xpi file from ~1MB to ~2MB (in the current master branch).
I guess we can live with that.  We should warn EFF's ops team though :).

On balance that cost seems outweighed by the startup time benefits, so
I think we should merge the pull request.

After that I'm wondering whether we should port in Nick Semenkovich's
fancier LRU caching layer (which is the chrome version of the extension
only right now) in place of the one you used; that has a few benefits:
(1) prevents us from needing to keep all of the targets table in RAM;
(2) optimises away all the expensive string manipulations in
potentiallyApplicableRulesets; (3) it's safe against having the negative
cache bloat indefinitely if the user never restarts their browser and
meets Lots and Lots of domains.

-- 
Peter Eckersley                            pde at eff.org
Technology Projects Director      Tel  +1 415 436 9333 x131
Electronic Frontier Foundation    Fax  +1 415 436 9993