From: "nobu (Nobuyoshi Nakada)" <nobu@...>
Date: 2013-06-27T17:26:30+09:00
Subject: [ruby-core:55669] [ruby-trunk - Feature #6183] Enumerator::Lazy performance issue


Issue #6183 has been updated by nobu (Nobuyoshi Nakada).


Your patch seems
* reverting inspect_enumerator()
* containing dead code

I pushed a branch which split and merged a few functions, and used function pointer tables.
https://github.com/nobu/ruby/tree/lazy_enum
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Feature #6183: Enumerator::Lazy performance issue
https://bugs.ruby-lang.org/issues/6183#change-40174

Author: gregolsen (Innokenty Mikhailov)
Status: Assigned
Priority: Low
Assignee: zzak (Zachary Scott)
Category: 
Target version: 


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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