From: "matz (Yukihiro Matsumoto)" <matz@...>
Date: 2012-04-03T17:47:28+09:00
Subject: [ruby-core:44102] [ruby-trunk - Bug #6183][Assigned] Enumerator::Lazy performance issue


Issue #6183 has been updated by matz (Yukihiro Matsumoto).

Status changed from Rejected to Assigned
Assignee set to nobu (Nobuyoshi Nakada)
Priority changed from Normal to Low

Nobu, could you review the patch?  And if you don't see any problem, check it in?

Matz.

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Bug #6183: Enumerator::Lazy performance issue
https://bugs.ruby-lang.org/issues/6183#change-25631

Author: gregolsen (Innokenty Mikhailov)
Status: Assigned
Priority: Low
Assignee: nobu (Nobuyoshi Nakada)
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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