hadoop-common-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Kevin J. Price (JIRA)" <j...@apache.org>
Subject [jira] Created: (HADOOP-6297) Hadoop's support for zlib library lacks support to perform flushes (Z_SYNC_FLUSH and Z_FULL_FLUSH)
Date Tue, 06 Oct 2009 15:01:31 GMT
Hadoop's support for zlib library lacks support to perform flushes (Z_SYNC_FLUSH and Z_FULL_FLUSH)
--------------------------------------------------------------------------------------------------

                 Key: HADOOP-6297
                 URL: https://issues.apache.org/jira/browse/HADOOP-6297
             Project: Hadoop Common
          Issue Type: Improvement
          Components: io
    Affects Versions: 0.21.0
            Reporter: Kevin J. Price
            Priority: Minor


The zlib library supports the ability to perform two types of flushes when deflating data.
It can perform both a Z_SYNC_FLUSH, which forces all input to be written as output and byte-aligned
and resets the Huffman coding, and it also supports a Z_FULL_FLUSH, which does the same thing
but additionally resets the compression dictionary.  The Hadoop wrapper for the zlib library
does not support either of these two methods.

Adding support should be fairly trivial.  An additional deflate method that takes a fourth
"flush" parameter, and a modification to the native c code to accept this fourth parameter
and pass it along to the zlib library.  I can submit a patch for this if desired.

It should be noted that the native SUN Java API is likewise missing this functionality, as
has been noted for over a decade here: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4206909

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message