bit-deserializer.cc

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/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2020 Universita' di Firenze, Italy
 *
 * 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: Tommaso Pecorella <tommaso.pecorella@unifi.it>
 */

#include <iostream>
#include "bit-deserializer.h"
#include "ns3/log.h"
#include "ns3/abort.h"

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("BitDeserializer");

BitDeserializer::BitDeserializer ()
{
  NS_LOG_FUNCTION (this);
  m_deserializing = false;
}

void BitDeserializer::PushBytes (std::vector<uint8_t> bytes)
{
  NS_LOG_FUNCTION (this << bytes);
  NS_ABORT_MSG_IF (m_deserializing, "Can't add bytes after deserialization started");
  m_bytesBlob.insert (m_bytesBlob.end (), bytes.begin (), bytes.end ());
}

void BitDeserializer::PushBytes (uint8_t* bytes, uint32_t size)
{
  NS_LOG_FUNCTION (this << bytes << size);
  NS_ABORT_MSG_IF (m_deserializing, "Can't add bytes after deserialization started");
  for (uint32_t index = 0; index < size; index++)
    {
      m_bytesBlob.push_back (bytes[index]);
    }
}

void BitDeserializer::PushByte (uint8_t byte)
{
  NS_LOG_FUNCTION (this << +byte);
  NS_ABORT_MSG_IF (m_deserializing, "Can't add bytes after deserialization started");
  m_bytesBlob.push_back (byte);
}

uint64_t BitDeserializer::GetBits (uint8_t size)
{
  NS_LOG_FUNCTION (this << +size);
  uint8_t result = 0;
  PrepareDeserialization ();

  NS_ABORT_MSG_IF (size > 64, "Number of requested bits exceeds 64");
  NS_ABORT_MSG_IF (size > m_blob.size (), "Number of requested bits exceeds blob size");

  for (uint8_t i = 0; i < size; i++)
    {
      result <<= 1;
      result |= m_blob.front ();
      m_blob.pop_front ();
    }
  return result;
}

void BitDeserializer::PrepareDeserialization ()
{
  NS_LOG_FUNCTION (this);
  if (m_deserializing == false)
    {
      m_deserializing = true;
      for (auto index = m_bytesBlob.begin (); index != m_bytesBlob.end (); index++)
        {
          m_blob.push_back (*index & 0x80);
          m_blob.push_back (*index & 0x40);
          m_blob.push_back (*index & 0x20);
          m_blob.push_back (*index & 0x10);
          m_blob.push_back (*index & 0x8);
          m_blob.push_back (*index & 0x4);
          m_blob.push_back (*index & 0x2);
          m_blob.push_back (*index & 0x1);
        }
    }
}

} // namespace ns3