From: Heesob Park <phasis@...>
Date: 2009-01-10T08:36:56+09:00
Subject: Re: Pure Ruby Zlib::GzipWriter

Hi,

2009/1/10 Daniel Berger <djberg96@gmail.com>:
> Hi,
>
> On Jan 8, 8:23 pm, "Heesob Park" <pha...@gmail.com> wrote:
>> 2009/1/8 Daniel Berger <djber...@gmail.com>:
>>
>> > On Jan 7, 11:08 pm, "Heesob Park" <pha...@gmail.com> wrote:
>> >> Hi,
>>
>> >> 2009/1/8 Charles L. <aquas...@gmail.com>:> Daniel Berger wrote:
>>
>> >> >> Sounds like you're on track. But, you're in a race with Park Heesob. :)
>>
>> >> >> Dan
>>
>> >> > Heh. :) Somehow I think he's got it covered. That reimplementation of
>> >> > zlib in ruby is actually pretty cool. I'm curious Park, as to how much
>> >> > you did by hand and how much you were able to automate it...?
>>
>> >> I dit it all by hand. There is no royal road to translating C to Ruby:)
>>
>> >> > I've put the deflate code i wrote on pastie -http://pastie.org/355367
>>
>> > Excellent, thanks!
>>
>> >> > It's about 600 lines, but needs cleaning up. Will probably be ~500 when
>> >> > I've added in dynamic trees and cleaned it up a bit.
>>
>> >> > Prelim benchmarks show the current bottleneck to be the LZ77
>> >> > implementation which is interesting. I think for it to perform
>> >> > acceptably, a lot more of the code needs to become more idiomatic,
>> >> > higher-level ruby.
>>
>> >> In my test, the deflation is very slow but the inflation is endurable.
>> >> Moreover, for the compatibility of the various Ruby version, It shows
>> >> bad performance in Ruby 1.8.x.
>>
>> > As long as it's usable I'm happy. We can benchmark, profile and
>> > optimize later. :)
>>
>> Finally I translated the whole zlib.c to ruby code.
>> You can download athttp://121.78.227.9/rbzlib/pzlib.rb
>
> Looks very promising but doesn't quite work yet:
>
> C:\>gem install ptools
> ERROR:  While executing gem ... (NoMethodError)
>    undefined method `ZSTREAM_IS_FINISHED' for #<Zlib::GzipReader:
> 0x2f8e8bc>
>
> I think you need some tests. ;)
>
> BTW, I'm assuming this is basically a wholesale replacement of zliby?
> If so, the module should be renamed from PZlib to just Zlib.
> Otherwise, Rubygems will complain about the lack of a Gem::Zlib
> definition.
>
> Keep up the good work!
>
I fixed some typo and renamed PZlib to Zlib and pzlib.rb to zlib.rb
I succeeded "gem install ptools" with zlib.rb

You can download it at http://121.78.227.9/rbzlib/zlib.rb

Regards,

Park Heesob