helper/ccnb-parser/visitors/ccnb-parser-timestamp-visitor.cc

/* -*- Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil -*- */
/*
 * Copyright (c) 2011 University of California, Los Angeles
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
 */

#include "ccnb-parser-timestamp-visitor.h"
#include "ns3/ccnb-parser-blob.h"

#include "ns3/nstime.h"

namespace ns3 {
namespace CcnbParser {

boost::any/*Time*/
TimestampVisitor::visit (Blob &n) 
{
  // Buffer n.m_blob;
  if (n.m_blobSize < 2)
    throw CcnbDecodingException ();

  const char *start = n.m_blob;
  
  intmax_t seconds = 0;
  intmax_t nanoseconds = 0;

  for (uint32_t i=0; i < n.m_blobSize-2; i++)
    {
      seconds = (seconds << 8) | (uint8_t)start[i];
    }
  uint8_t combo = start[n.m_blobSize-2]; // 4 most significant bits hold 4 least significant bits of number of seconds
  seconds = (seconds << 4) | (combo >> 4);

  nanoseconds = combo & 0x0F; /*00001111*/ // 4 least significant bits hold 4 most significant bits of number of
  nanoseconds = (nanoseconds << 8) | start[n.m_blobSize-1];
  nanoseconds = (intmax_t) ((nanoseconds / 4096.0/*2^12*/) * 1000000 /*up-convert useconds*/);

  return boost::any (Time::FromInteger (seconds, Time::S) + Time::FromInteger (nanoseconds, Time::US));
}

boost::any
TimestampVisitor::visit (Udata &n)
{
  // std::string n.m_udata;
  throw CcnbDecodingException ();
}

}
}