Inflater/Deflater improvements

Ulf Zibis Ulf.Zibis at
Tue May 19 00:15:17 UTC 2009

But remember, the my interest in this discussion is not class loading 
speed, it's resource file loading speed. ;-)


Am 18.05.2009 22:21, Xueming Shen schrieb:
> Performance of Inflater/Deflater does not change the class loading 
> performance from
> jar files bundled with JDK/JRE, they have been "uncompressed" after 
> installation...
> Sherman
> Ulf Zibis wrote:
>> Am 04.05.2009 23:38, Martin Buchholz schrieb:
>>> I think many people will be interested in performance improvements
>>> in Inflater/Deflater.  I may have time to help review.
>> Yes, there is also interest from charset de/encoding side. See:
>> Current charset mapping tables are hosted as huge String constants 
>> inside charset classes. Hosting them as resource data files would 
>> would avoid ~50 % disk-footprint wastage of the charsets.jar. 
>> Additionally sharing of overlapping charset mapping data would become 
>> manageable. Currently we only have ClassLoader#getResouceAsStream() 
>> to load such data files, but we can't use it, because the underlying 
>> buffered stream is too slow in respect of JVM startup time. We need 
>> fast nio direct buffer access via java.nio.channels.Channel to load 
>> the data from charsets.jar.
>> So improving performance of jar/zip file access would be much 
>> appreciated. :-)
>> -Ulf

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