include/opencascade/StdStorage_Data.hxx

0001 // Copyright (c) 2017 OPEN CASCADE SAS
0002 //
0003 // This file is part of Open CASCADE Technology software library.
0004 //
0005 // This library is free software; you can redistribute it and/or modify it under
0006 // the terms of the GNU Lesser General Public License version 2.1 as published
0007 // by the Free Software Foundation, with special exception defined in the file
0008 // OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
0009 // distribution for complete text of the license and disclaimer of any warranty.
0010 //
0011 // Alternatively, this file may be used under the terms of Open CASCADE
0012 // commercial license or contractual agreement.
0013
0014 #ifndef _StdStorage_Data_HeaderFile
0015 #define _StdStorage_Data_HeaderFile
0016
0017 #include <Standard_Transient.hxx>
0018 #include <Standard_Macro.hxx>
0019 #include <Standard_Handle.hxx>
0020
0021 class StdStorage_HeaderData;
0022 class StdStorage_TypeData;
0023 class StdStorage_RootData;
0024
0025 //! A picture memorizing the stored in a
0026 //! container (for example, in a file).
0027 //! A StdStorage_Data object represents either:
0028 //! -   persistent data to be written into a container,
0029 //! or
0030 //! -   persistent data which are read from a container.
0031 //! A StdStorage_Data object is used in both the
0032 //! storage and retrieval operations:
0033 //! -   Storage mechanism: create an empty
0034 //! StdStorage_Data object, then add successively
0035 //! persistent objects (roots) to be stored using
0036 //! the StdStorage_RootData's function AddRoot. When the set of
0037 //! data is complete, write it to a container using the
0038 //! function Write in your StdStorage algorithm.
0039 //! -   Retrieval mechanism: a StdStorage_Data
0040 //! object is returned by the Read function from
0041 //! your StdStorage algorithm. Use the StdStorage_RootData's
0042 //! functions NumberOfRoots and Roots to find the roots which
0043 //! were stored in the read container.
0044 //! The roots of a StdStorage_Data object may share
0045 //! references on objects. The shared internal
0046 //! references of a StdStorage_Data object are
0047 //! maintained by the storage/retrieval mechanism.
0048 //! Note: References shared by objects which are
0049 //! contained in two distinct StdStorage_Data objects
0050 //! are not maintained by the storage/retrieval
0051 //! mechanism: external references are not
0052 //! supported by Storage_Schema algorithm
0053 class StdStorage_Data : public Standard_Transient
0054 {
0055
0056 public:
0057   //! Creates an empty set of data.
0058   //! You explicitly create a StdStorage_Data object
0059   //! when preparing the set of objects to be stored
0060   //! together in a container (for example, in a file).
0061   //! Then use the function StdStorage_RootData's AddRoot
0062   //! to add persistent objects to the set of data.
0063   //! A StdStorage_Data object is also returned by the
0064   //! Read function of a StdStorage algorithm. Use the
0065   //! StdStorage_RootData's functions NumberOfRoots and
0066   //! Roots to find the roots which were stored in the
0067   //! read container.
0068   Standard_EXPORT StdStorage_Data();
0069
0070   //! Makes the container empty
0071   Standard_EXPORT void Clear();
0072
0073   //! Returns the header data section
0074   Handle(StdStorage_HeaderData) HeaderData() { return myHeaderData; }
0075
0076   //! Returns the type data section
0077   Handle(StdStorage_TypeData) TypeData() { return myTypeData; }
0078
0079   //! Returns the root data section
0080   Handle(StdStorage_RootData) RootData() { return myRootData; }
0081
0082 private:
0083   Handle(StdStorage_HeaderData) myHeaderData;
0084   Handle(StdStorage_TypeData)   myTypeData;
0085   Handle(StdStorage_RootData)   myRootData;
0086 };
0087
0088 #endif // _StdStorage_Data_HeaderFile