Sequencer.cc

// Copyright 2008 Michael Marsh, University of Maryland.
//
// This file is part of pydtn.
//
// pydtn is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// pydtn 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 pydtn.  If not, see <http://www.gnu.org/licenses/>.
//
// The views and conclusions contained in the software and documentation
// are those of the authors and should not be interpreted as representing
// official policies, either expressed or implied, of the University
// of Maryland.
//
// pydtn extends and embeds the Python interpreter, which is
// Copyright 2001-2006 Python Software Foundation, All Rights Reserved,
// and is released under the PSF License Agreement.
//
// RANLUX random number generation uses the Boost library,
// Copyright 1994-2006 by various authors (details in individual files),
// which is released under the Boost Software License, Version 1.0.

#include "Sequencer.h"

Sequencer::Sequencer() :
   m_seenAny( false ),
   m_stragglers( 0 )
{
}

Sequencer::Sequencer( const Sequencer& seq ) :
   m_seenAny( seq.m_seenAny ),
   m_first( seq.m_first ),
   m_through( seq.m_through ),
   m_stragglers( seq.m_stragglers )
{
}

Sequencer::~Sequencer()
{
   if ( 0 != m_stragglers )
   {
      delete m_stragglers;
   }
}

bool
Sequencer::add( uint32_t s )
{
   if ( ! m_seenAny )
   {
      m_seenAny = true;
      m_first = s;
      m_through = s;
      return true;
   }
   if ( s < m_first )
   {
      if ( s == (m_first - 1) )
      {
         m_first = s;
         return true;
      }
      Sequencer* temp = new Sequencer( *this );
      m_first = s;
      m_through = s;
      m_stragglers = temp;
      return true;
   }
   if ( s <= m_through )
   {
      return false;
   }
   if ( s == (m_through + 1) )
   {
      m_through = s;

      // grab the front of stragglers if appropriate
      if ( 0 != m_stragglers )
      {
         if ( m_stragglers->m_first == (m_through+1) )
         {
            m_through = m_stragglers->m_through;
            Sequencer* temp = m_stragglers;
            m_stragglers = temp->m_stragglers;
            temp->m_stragglers = 0;
            delete temp;
         }
      }

      return true;
   }
   if ( 0 == m_stragglers )
   {
      m_stragglers = new Sequencer();
   }
   return m_stragglers->add(s);
}

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