FSDataOutputStream.write() allocates new byte buffer on each operation

 private DFSPacket createPacket(int packetSize, int chunksPerPkt, long offsetInBlock, long seqno, boolean lastPacketInBlock) throws InterruptedIOException {
     final byte[] buf;
     final int bufferSize = PacketHeader.PKT_MAX_HEADER_LEN +   packetSize;
 
     try {
       buf = byteArrayManager.newByteArray(bufferSize);
     } catch (InterruptedException ie) {
       final InterruptedIOException iioe = new InterruptedIOException(
           "seqno=" + seqno);
       iioe.initCause(ie);
       throw iioe;
     }
 
     return new DFSPacket(buf, chunksPerPkt, offsetInBlock, seqno,
                          getChecksumSize(), lastPacketInBlock);
}