ThePEG/Persistency/InputDescription.h

0001 // -*- C++ -*-
0002 //
0003 // InputDescription.h is a part of ThePEG - Toolkit for HEP Event Generation
0004 // Copyright (C) 1999-2019 Leif Lonnblad
0005 //
0006 // ThePEG is licenced under version 3 of the GPL, see COPYING for details.
0007 // Please respect the MCnet academic guidelines, see GUIDELINES for details.
0008 //
0009 #ifndef ThePEG_InputDescription_H
0010 #define ThePEG_InputDescription_H
0011 // This is the declaration of the InputDescription class.
0012
0013 #include "ThePEG/Config/ThePEG.h"
0014 #include "ThePEG/Utilities/ClassDescription.h"
0015
0016 namespace ThePEG {
0017
0018 /** @ingroup Persistency
0019  * InputDescription objects are used by the PersistentIStream class to
0020  * keep track of all classes it has read from a stream. It keeps a
0021  * pointer to the corresponding ClassDescription in case the class
0022  * read in was actually present in the current program, a version
0023  * number of the read class which may be different from the class
0024  * present in the current program and a list of base class
0025  * <code>InputDescription</code>s.
0026  *
0027  * @see PersistentIStream
0028  * @see Named
0029  * @see ClassDescription
0030  */
0031 class InputDescription: public Named {
0032
0033 public:
0034
0035   /** A vector of pointers to InputDescription objects. */
0036   typedef vector<const InputDescription *> DescriptionVector;
0037
0038   ThePEG_DECLARE_POINTERS(PersistentBase,BPtr);
0039
0040 public:
0041
0042   /**
0043    * The standard constructor.
0044    * @param newName the name of the class being read.
0045    * @param newVersion the version number of the class when written.
0046    */
0047   InputDescription(string newName, int newVersion)
0048     : Named(newName), theDescription(0), theVersion(newVersion) {}
0049
0050   /**
0051    * Set the ClassDescriptionBase object of the class being read.
0052    */
0053   void setDescription(const ClassDescriptionBase * cd) {
0054     theDescription = cd;
0055   }
0056
0057   /**
0058    * Add a base class description.
0059    */
0060   void addBaseClass(const InputDescription * newBase) {
0061     theBaseClasses.push_back(newBase);
0062   }
0063
0064   /**
0065    * Return the list of base class descriptions.
0066    */
0067   const DescriptionVector & descriptions() const {
0068     return theBaseClasses;
0069   }
0070
0071   /**
0072    * Create an object of the corresponding class.
0073    */
0074   BPtr create() const {
0075     if ( theDescription ) return theDescription->create();
0076     DescriptionVector::const_iterator dit = theBaseClasses.begin();
0077     while ( dit != theBaseClasses.end() ) {
0078       BPtr obj = (*dit++)->create();
0079       if ( obj ) return obj;
0080     }
0081     return BPtr();
0082   }
0083
0084   /**
0085    * Read an object part of the corresponding class from a stream.
0086    * Will only read the part of the object corresponding to the
0087    * members of the class represented by this object.
0088    */
0089   void input(tBPtr b, PersistentIStream & is) const {
0090     if ( theDescription ) theDescription->input(b, is, theVersion);
0091   }
0092
0093 private:
0094
0095   /**
0096    * The list of base class descriptions.
0097    */
0098   DescriptionVector theBaseClasses;
0099
0100   /**
0101    * The description of the corresponding class in the current
0102    * program.
0103    */
0104   const ClassDescriptionBase * theDescription;
0105
0106   /**
0107    * The version of the class to be read.
0108    */
0109   int theVersion;
0110
0111 };
0112
0113 }
0114
0115 #endif /* ThePEG_InputDescription_H */