[HDFS-6885] Fix wrong use of BytesWritable in FSEditLogOp#RenameOp

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: namenode
• Labels: BB2015-05-TBR
• Target Version/s: 2.8.0
• Hadoop Flags: Reviewed
• Assignee: Yi Liu
• Reporter: Yi Liu
• Created: 20/Aug/14 08:42
• Updated: 30/Aug/16 01:41
• Resolved: 23/Nov/15 01:18

Description

After readField using BytesWritable, the data length should be writable.getLength(), instead of writable.getBytes().length which is the buffer length.
This will cause returned Rename[] is longer than expected and may include some incorrect values (Currently they are Rename#NONE, and have not caused problem but code logic is incorrect).

BytesWritable writable = new BytesWritable();
writable.readFields(in);

byte[] bytes = writable.getBytes();
Rename[] options = new Rename[bytes.length];

for (int i = 0; i < bytes.length; i++) {
  options[i] = Rename.valueOf(bytes[i]);
}