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https://issues.apache.org/jira/browse/COMPRESS-388?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15981781#comment-15981781
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Gary Gregory edited comment on COMPRESS-388 at 4/24/17 9:16 PM:
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Great. thank you.
I'll let [~bodewig] apply the patch.
Gary
was (Author: garydgregory):
Great. thank you.
Gary
> Improve concurrent reads from ZipFile
> -------------------------------------
>
> Key: COMPRESS-388
> URL: https://issues.apache.org/jira/browse/COMPRESS-388
> Project: Commons Compress
> Issue Type: Improvement
> Components: Archivers
> Affects Versions: 1.13
> Environment: Any
> Reporter: Zbynek Vyskovsky
> Labels: patch, performance
> Fix For: 1.14
>
> Original Estimate: 2h
> Remaining Estimate: 2h
>
> Concurrent reads on the ZipFile archive is terribly slow on multiprocessor
> systems. On my 4 CPU laptop it shows 26 reads/s vs 2 reads/s on 100MB samples
> for example.
> The cause is the use of synchronized blocks to access the underlying file
> channel. This may be required for generic SeekableByteChannel but most
> commonly there is FileChannel implementation which supports lock-free reading
> from any position (i.e. using pread/pwrite system calls or their equivalent).
> With the fix the performance is about 10 times faster (on 4 CPU system, with
> more processor the difference should grow significantly).
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