include/GaudiKernel/SmartRefBase.h

0001 /***********************************************************************************\
0002 * (c) Copyright 1998-2021 CERN for the benefit of the LHCb and ATLAS collaborations *
0003 *                                                                                   *
0004 * This software is distributed under the terms of the Apache version 2 licence,     *
0005 * copied verbatim in the file "LICENSE".                                            *
0006 *                                                                                   *
0007 * In applying this licence, CERN does not waive the privileges and immunities       *
0008 * granted to it by virtue of its status as an Intergovernmental Organization        *
0009 * or submit itself to any jurisdiction.                                             *
0010 \***********************************************************************************/
0011 //  ====================================================================
0012 //  SmartRefBase.h
0013 //  --------------------------------------------------------------------
0014 //
0015 //  Package   : Gaudi/Kernel
0016 //              Base class for SmartReference objects
0017 //
0018 //  Author    : Markus Frank
0019 //
0020 //  ====================================================================
0021 #ifndef KERNEL_SMARTREFBASE_H
0022 #define KERNEL_SMARTREFBASE_H 1
0023
0024 // Framework include files
0025 #include "GaudiKernel/StreamBuffer.h"
0026
0027 class ObjectContainerBase;
0028 class SmartRefBase;
0029 class ContainedObject;
0030 class DataObject;
0031
0032 /** User example objects: SmartRefBase
0033
0034     Description:
0035     Base class of SmartReference objects. The base class handles the
0036     object requests to the data store.
0037     The separation of the SmartReference and the base class is mainly to
0038     avoid code blow up, because if the object is not yet present
0039     serious work must be performed in order to request the object from the
0040     store and invoke object updates to keep pointers in sync.
0041
0042     Base Class: None
0043
0044     Dependencies: None
0045
0046     <P> History    :
0047     <PRE>
0048     +---------+----------------------------------------------+--------+
0049     |    Date |                 Comment                      | Who    |
0050     +---------+----------------------------------------------+--------+
0051     | 21/06/99| Initial version.                             | MF     |
0052     +---------+----------------------------------------------+--------+
0053     </PRE>
0054     Author:  M.Frank
0055     Version: 1.0
0056 */
0057 class GAUDI_API SmartRefBase {
0058 public:
0059   /// Object data: ID of the link hint to the identifiable object
0060   mutable long m_hintID;
0061   /// Object data: ID of the object within the identifiable container (if any)
0062   mutable long m_linkID;
0063   /// Object data: Pointer to the identifiable object the link originates
0064   mutable const DataObject* m_data;
0065   /// Object data: Pointer to the Contained object (if applicable)
0066   mutable const ContainedObject* m_contd;
0067
0068   mutable long m_type;
0069
0070   enum { DATAOBJECT, CONTAINEDOBJECT };
0071
0072   /// Load on demand of ContainedObject like references
0073   const ContainedObject* accessData( const ContainedObject* typ ) const;
0074   /// Load on demand of DataObject like references
0075   const DataObject* accessData( const DataObject* typ ) const;
0076
0077   /// Extended equality check
0078   bool isEqualEx( const DataObject* pObj, const SmartRefBase& c ) const;
0079   /// Extended equality check
0080   bool isEqualEx( const ContainedObject* pObj, const SmartRefBase& c ) const;
0081   /// Equality operator for ContainedObject like references
0082   bool isEqual( const ContainedObject* /* pObj */, const SmartRefBase& c ) const {
0083     return ( m_hintID == c.m_hintID && m_linkID == c.m_linkID && m_data == c.m_data && m_contd == c.m_contd );
0084   }
0085   /// Equality operator for DataObject like references
0086   bool isEqual( const DataObject* /* pObj */, const SmartRefBase& c ) const {
0087     return m_linkID == c.m_linkID && m_data == c.m_data;
0088   }
0089   /// Output streamer for DataObject like references
0090   void writeObject( const DataObject* pObject, StreamBuffer& s ) const { s.addIdentifiedLink( pObject, m_hintID ); }
0091   /// Output streamer for ContainedObject like references
0092   void writeObject( const ContainedObject* pObject, StreamBuffer& s ) const {
0093     s.addContainedLink( pObject, m_hintID, m_linkID );
0094   }
0095   /// Input streamer for DataObject like references
0096   DataObject* readObject( const DataObject* /* pObject */, StreamBuffer& s ) const {
0097     DataObject* pObj = 0;
0098     s.getIdentifiedLink( pObj, m_hintID );
0099     return pObj;
0100   }
0101   /// Output streamer for ContainedObject like references
0102   ContainedObject* readObject( const ContainedObject* /* pObject */, StreamBuffer& s ) const {
0103     ContainedObject* pObj = 0;
0104     s.getContainedLink( pObj, m_hintID, m_linkID );
0105     return pObj;
0106   }
0107   void setObjectType( const ContainedObject* /* pobj */ ) const { m_type = CONTAINEDOBJECT; }
0108   void setObjectType( const DataObject* /* pobj */ ) const { m_type = DATAOBJECT; }
0109
0110   /// Shortcut to access the path to the linked object.
0111   const std::string& path() const;
0112
0113 public:
0114   long objectType() const { return m_type; }
0115   /// Setup smart reference when reading. Must be allowed from external sources.
0116   void set( DataObject* pObj, long hint_id, long link_id );
0117 };
0118 #endif // KERNEL_SMARTREFBASE_H