// $Id: AllocatorPool.cpp,v 1.3 2007/05/24 14:39:11 hmd Exp $ 
// ============================================================================
// CVS tag $Name:  $, version $Revision: 1.3 $
// ============================================================================
/** @file
 *  Implementation file for the class GaudiUtils::AllocatorPool.h
 *  This file is copied form Geant4 project
 *  @date 2006-02-10
 */
// ============================================================================
//
// ********************************************************************
// * DISCLAIMER                                                       *
// *                                                                  *
// * The following disclaimer summarizes all the specific disclaimers *
// * of contributors to this software. The specific disclaimers,which *
// * govern, are listed with their locations in:                      *
// *   http://cern.ch/geant4/license                                  *
// *                                                                  *
// * Neither the authors of this software system, nor their employing *
// * institutes,nor the agencies providing financial support for this *
// * work  make  any representation or  warranty, express or implied, *
// * regarding  this  software system or assume any liability for its *
// * use.                                                             *
// *                                                                  *
// * This  code  implementation is the  intellectual property  of the *
// * GEANT4 collaboration.                                            *
// * By copying,  distributing  or modifying the Program (or any work *
// * based  on  the Program)  you indicate  your  acceptance of  this *
// * statement, and all its terms.                                    *
// ********************************************************************
//
// ----------------------------------------------------------------------
// G4AllocatorPool
//
// Implementation file
//
// Author: G.Cosmo, November 2000
//
// ============================================================================
// Include files 
// ============================================================================
// GaudiKernel
// ============================================================================
#include "GaudiKernel/AllocatorPool.h"
// ============================================================================

// ************************************************************
// G4AllocatorPool constructor
// ************************************************************
//
GaudiUtils::AllocatorPool::AllocatorPool
( unsigned int sz )
  : esize(sz<sizeof(PoolLink) ? sizeof(PoolLink) : sz),
    csize(sz<1024/2-16 ? 1024-16 : sz*10-16),
    chunks(0), head(0), nchunks(0)
{}

// ************************************************************
// G4AllocatorPool copy constructor
// ************************************************************
//
GaudiUtils::AllocatorPool::AllocatorPool(const AllocatorPool& right)
  : esize(right.esize), csize(right.csize)
{
  *this = right;
} 

// ************************************************************
// G4AllocatorPool operator=
// ************************************************************
//
GaudiUtils::AllocatorPool&
GaudiUtils::AllocatorPool::operator= 
(const GaudiUtils::AllocatorPool& right)
{
  if (&right == this) { return *this; }
  chunks  = right.chunks;
  head    = right.head;
  nchunks = right.nchunks;
  return *this;
}

// ************************************************************
// G4AllocatorPool destructor
// ************************************************************
//
GaudiUtils::AllocatorPool::~AllocatorPool()
{
  Reset();
}

// ************************************************************
// Reset
// ************************************************************
//
void GaudiUtils::AllocatorPool::Reset()
{
  // Free all chunks
  //
  PoolChunk* n = chunks;
  PoolChunk* p = 0;
  while (n)
  {
    p = n;
    n = n->next;
    delete p;
  }
  head = 0;
  chunks = 0;
  nchunks = 0;
}

// ************************************************************
// Grow
// ************************************************************
//
void GaudiUtils::AllocatorPool::Grow()
{
  // Allocate new chunk, organize it as a linked list of
  // elements of size 'esize'
  //
  PoolChunk* n = new PoolChunk(csize);
  n->next = chunks;
  chunks = n;
  nchunks++;
  
  const int nelem = csize/esize;
  char* start = n->mem;
  char* last = &start[(nelem-1)*esize];
  for (char* p=start; p<last; p+=esize)
  {
    reinterpret_cast<PoolLink*>(p)->next
      = reinterpret_cast<PoolLink*>(p+esize);
  }
  reinterpret_cast<PoolLink*>(last)->next = 0;
  head = reinterpret_cast<PoolLink*>(start);
}


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// The END 
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