From: Eric Wong <normalperson@...>
Date: 2014-05-21T01:27:03+00:00
Subject: [ruby-core:62700] Re: [PREVIEW] enc: convert some case fold tables to ihash

Nobuyoshi Nakada <nobu@ruby-lang.org> wrote:
> (2014/05/21 7:03), Eric Wong wrote:
> > Not a serious patch, yet, but this saves over 100K as measured with:
> Rather I'd like to convert these tables to perfect hashes.

OK, I'll have to look more into that.

> > Download: http://80x24.org/casefold-ihash.patch
http://80x24.org/casefold-ihash.patch
> 
> Why removed `const`s?

I embed the rb_ihash_node struct into the original Case*Type structs.
rb_ihash_add_direct writes directly to the rb_ihash_node struct
to avoid per-entry allocation.  We avoid (1357 + 1207) mallocs
for st_table_entry this way.

Also, I'm looking at ccan[1] htable instead of ihash.  It is currently
LGPL, but based on ccan commit d4941bf8047d16007f19a3b5b2211e1e7571f068,
relicensing to BSD/CC0 is a possiblility.

[1] git://git.ozlabs.org/~ccan/ccan