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From "Arun C Murthy (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HADOOP-538) Implement a nio's 'direct buffer' based wrapper over zlib to improve performance of java.util.zip.{De|In}flater as a 'custom codec'
Date Tue, 26 Sep 2006 04:04:52 GMT
    [ http://issues.apache.org/jira/browse/HADOOP-538?page=comments#action_12437727 ] 
            
Arun C Murthy commented on HADOOP-538:
--------------------------------------

Couple of insights gleaned from a discussion with Owen:

a) The proposed DataCompression{In|Out}putStreams should probably be 'package private' instead
of public, since it is more of an implementation detail; hence it probably shouldn't affect
the public api.

b) The {Com|Decom}pressor interfaces should not have any public apis which expose the 'nio
direct buffer' details - presumably they are implementation details. 

  The public apis should only be:

  public int deflate(byte[] b, int off, int len);   // Compressor
  and 
  public int inflate(byte[] b, int off, int len);   // Decompressor

  We should leave it to the actual zlib/lzo/* (de)compressors to use nio as they see fit.

Thanks Owen!

> Implement a nio's 'direct buffer' based wrapper over zlib to improve performance of java.util.zip.{De|In}flater
as a 'custom codec'
> -----------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: HADOOP-538
>                 URL: http://issues.apache.org/jira/browse/HADOOP-538
>             Project: Hadoop
>          Issue Type: Improvement
>    Affects Versions: 0.6.1
>            Reporter: Arun C Murthy
>         Assigned To: Arun C Murthy
>             Fix For: 0.7.0
>
>
> There has been more than one instance where java.util.zip's {De|In}flater classes perform
unreliably, a simple wrapper over zlib-1.2.3 (latest stable) using java.nio.ByteBuffer (i.e.
direct buffers) should go a long way in alleviating these woes.

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