Hi all, I couldn't find a JIRA for compress so I'm posting it here.
We had a bug report against Ant's ZipOutputStream that showed that the class had a way worse performance compared to java.util.zip's cousin when it was used to compress big files. See https://issues.apache.org/bugzilla/show_bug.cgi?id=45396 Attached to this report is a small test class that could easily be adapted to the compress library. It turns out that java.util.Deflater doesn't like to see big arrays passed into its setInput method and the original reporter says OpenJDK's code would split the input into 512 byte chunks. While I didn't verify the OpenJDK code I went looking into zlib and InfoZIP and at least InfoZIP's zipup.c uses smaller chunks (between 2kB and 16kB) as well when compressing files. The change I've committed http://svn.apache.org/viewvc/ant/core/trunk/src/main/org/apache/tools/zip/ZipOutputStream.java?r1=579278&r2=677272&pathrev=677272 sped up the test by a factor of 40 on my machine. It won't have any effect on Ant since <zip> has always split up the file's content before writing it to the archive, but it would affect other direct users of our API - and would probably benefit the compress component for just that reason as well. Stefan --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
