1089300 - Investigating using Proxies instead of copies for fixArray

Status: RESOLVED WORKSFORME

(MailNews Core :: MIME, defect)

Description

[Joshua Cranmer [:jcranmer]]

Object duplication can be expensive, especially since we're iterating over prototype slots so we can set the prototype. Creating a new Proxy wrapper should be faster, especially because the properties which require more than forwarding the get to the underlying property are likely to be more rarely called.

Comment 1

[Wayne Mery (:wsmwk)]

should we expect fixing this to be less difficult than the work needed to finish bug 1005413, with equal or better performance win?

from bug 1055077 comment 16

"> - recipient+sender+subject (<5sec, 225 hits)

http://people.mozilla.org/~bgirard/cleopatra/
?1414243934911#report=e1dca35ebe3369ff209382fa959f1f96336be903

Over here, I see fixArray is fairly expensive. Considering that I expect toString is rather little called (which is the main point of fixArray), I suspect I can probably make this much cheaper by using proxies for toString instead of resetting prototypes. It's a bit nasty to code, but it should improve performance."

Comment 2

[Magnus Melin [:mkmelin]]

fixArray is long gone.