ElementLinkCnv_p3.icc

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/*
  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
*/
 
/** @file ElementLinkCnv_p3.icc
 *  @brief This file contains the implementation for the ElementLinkCnv_p3 template methods.
 *  @author Marcin.Nowak@cern.ch
 **/
 
#include <stdexcept>
 
#include "AthLinks/ElementLink.h"
#include "AthenaKernel/ThinningCache.h"
#include "AthenaKernel/ThinningDecisionBase.h"
#include "AthenaKernel/getThinningCache.h"
//#define ELLINK_DEBUG
 
 
template <typename LINK_TYPE>
void ElementLinkCnv_p3<LINK_TYPE>::
transToPers(const Link_t& trans, PersLink_t& pers,
            const SG::ThinningCache* cache,
            [[maybe_unused]] MsgStream& msg ) const
{
   if( !trans.isDefault() ) {
      // Check for thinning.
      if (cache) {
        const SG::ThinningDecisionBase* dec = cache->thinning (trans.key());
        if (dec) {
          // here is the problem: in case the ElementLink was directly created w/
          // only a pointer to the element, _and_ if the the pointed at element 
          // has been thinned away, EL::index() will throw b/c
          // IndexingPolicy::setIndex will fail.
          std::size_t idx = SG::ThinningDecisionBase::RemovedIdx;
          try {
            idx = trans.index();
          } catch ( const SG::maybe_thinning_error& err ) {
            // ok. that's the corner case we talked about above.
#ifdef  ELLINK_DEBUG
            msg << MSG::DEBUG << "caught a maybe_thinning_error: ["
                << err.what() << "]"
                << endmsg
                << "(this is an expected case of the EL-state-phase-space "
                << "when thinning is active)"
                << endmsg;
#endif
          }
 
          // Get the updated index:
          const std::size_t persIdx = dec->index( idx );
          if (SG::ThinningDecisionBase::RemovedIdx == persIdx)
          {
            pers = PersLink_t();
          }
          else {
            Link_t tmp = trans;
            tmp.toPersistent();
            pers.m_SGKeyHash       = tmp.key(); 
            pers.m_elementIndex    = persIdx;
          }
#ifdef  ELLINK_DEBUG
          msg << MSG::INFO << "ElementLinkCnv_p3::transToPer(): SG Container="
              << ", Key Hash=" << pers.m_SGKeyHash
              << ", IDX=" << pers.m_elementIndex << endmsg;
#endif
          return;
        }
      }
 
      // No thinning.
      Link_t tmp = trans;
      tmp.toPersistent();
      pers.m_SGKeyHash        = tmp.key(); 
      pers.m_elementIndex     = tmp.index();
#ifdef  ELLINK_DEBUG
      msg << MSG::INFO << "ElementLinkCnv_p3::transToPer(): SG Container="
          << ", Key Hash=" << pers.m_SGKeyHash
          << ", IDX=" << pers.m_elementIndex << endmsg;
#endif
   }
}
 
 
template <typename LINK_TYPE>
void ElementLinkCnv_p3<LINK_TYPE>::
transToPers(const Link_t& trans, PersLink_t& pers,
            MsgStream& msg ) const
{
  transToPers (trans, pers,
               SG::getThinningCache(),
               msg);
}
 
 
template <typename LINK_TYPE >
void ElementLinkCnv_p3< LINK_TYPE >
::persToTrans(const PersLink_t& pers, Link_t& trans,
              [[maybe_unused]] MsgStream& msg) const
{
   if( pers.m_SGKeyHash != 0 ) {
#ifdef  ELLINK_DEBUG
      msg << MSG::DEBUG << "ElementLinkCnv_p3::PersToTrans(): SGContainer hash="
      << pers.m_SGKeyHash << ", IDX=" << pers.m_elementIndex << endmsg;
#endif
      trans = Link_t( (typename Link_t::sgkey_t)pers.m_SGKeyHash, pers.m_elementIndex);
   }
   else {
#ifdef  ELLINK_DEBUG
      msg << MSG::DEBUG << "ElementLinkCnv_p3::PersToTrans(): reading EL in Default state" << endmsg;
#endif
      // set the transient ELink to the default state.
      trans.reset();
   } 
}
 
 
template <typename LINK_TYPE>
void ElementLinkCnv_p3<LINK_TYPE>::
transToPers(const Link_t* trans, PersLink_t* pers, MsgStream& msg ) const
{
  return transToPers (*trans, *pers, msg);
}
 
 
template <typename LINK_TYPE >
void ElementLinkCnv_p3< LINK_TYPE >
::persToTrans(const PersLink_t* pers, Link_t* trans, MsgStream& msg) const
{
  return persToTrans (*pers, *trans, msg);
}