From: "gregolsen (Innokenty Mikhailov)" <anotheroneman@...>
Date: 2012-12-03T22:28:04+09:00
Subject: [ruby-core:50523] [ruby-trunk - Bug #6183] Enumerator::Lazy performance issue


Issue #6183 has been updated by gregolsen (Innokenty Mikhailov).

File December_3.diff added

I've merged the patch with latest trunk (see latest diff attached), specifically with Enumerator lazy size feature.
Also I've removed the ugly case switch: proc entry stores pointer to a function that is executed when iterating over the elements.
So now it even resembles the current implementation a bit.

Please, let me know your thoughts about all this.
Thanks in advance.
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Bug #6183: Enumerator::Lazy performance issue
https://bugs.ruby-lang.org/issues/6183#change-34361

Author: gregolsen (Innokenty Mikhailov)
Status: Assigned
Priority: Low
Assignee: mame (Yusuke Endoh)
Category: 
Target version: 
ruby -v: ruby 2.0.0dev (2012-03-17 trunk 35075) [x86_64-linux]


I benchmarked Enumerator::Lazy and that's what I got:
                 user     system      total        real
Lazy:        0.690000   0.010000   0.700000 (  0.733160)
Normal:      0.160000   0.010000   0.170000 (  0.186695)

It seems like even with 4 chain links and 3000 elements in initial array, Lazy enumerator is almost 4(!) times slower than the normal case.

Instead of performance benefit we've got 4 times performance drawback.

See test file attached.


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