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Hudson commented on HDFS-2834: ------------------------------ Integrated in Hadoop-Mapreduce-trunk-Commit #1920 (See [https://builds.apache.org/job/Hadoop-Mapreduce-trunk-Commit/1920/]) HDFS-2834. Add a ByteBuffer-based read API to DFSInputStream. Contributed by Henry Robinson. (Revision 1303474) Result = ABORTED todd : http://svn.apache.org/viewcvs.cgi/?root=Apache-SVN&view=rev&rev=1303474 Files : * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/BlockReader.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/BlockReaderLocal.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSInputStream.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/RemoteBlockReader.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/RemoteBlockReader2.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/BlockReaderTestUtil.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestBlockReaderLocal.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestParallelRead.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestParallelReadUtil.java * /hadoop/common/trunk/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestShortCircuitLocalRead.java > ByteBuffer-based read API for DFSInputStream > -------------------------------------------- > > Key: HDFS-2834 > URL: https://issues.apache.org/jira/browse/HDFS-2834 > Project: Hadoop HDFS > Issue Type: Improvement > Reporter: Henry Robinson > Assignee: Henry Robinson > Fix For: 0.24.0 > > Attachments: HDFS-2834-no-common.patch, HDFS-2834.10.patch, > HDFS-2834.11.patch, HDFS-2834.3.patch, HDFS-2834.4.patch, HDFS-2834.5.patch, > HDFS-2834.6.patch, HDFS-2834.7.patch, HDFS-2834.8.patch, HDFS-2834.9.patch, > HDFS-2834.patch, HDFS-2834.patch, hdfs-2834-libhdfs-benchmark.png > > > The {{DFSInputStream}} read-path always copies bytes into a JVM-allocated > {{byte[]}}. Although for many clients this is desired behaviour, in certain > situations, such as native-reads through libhdfs, this imposes an extra copy > penalty since the {{byte[]}} needs to be copied out again into a natively > readable memory area. > For these cases, it would be preferable to allow the client to supply its own > buffer, wrapped in a {{ByteBuffer}}, to avoid that final copy overhead. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira