tripwire-open-source/src/core/serializable.h

126 lines
5.2 KiB
C++

//
// The developer of the original code and/or files is Tripwire, Inc.
// Portions created by Tripwire, Inc. are copyright (C) 2000-2017 Tripwire,
// Inc. Tripwire is a registered trademark of Tripwire, Inc. All rights
// reserved.
//
// This program is free software. The contents of this file are subject
// to the terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2 of the License, or (at your
// option) any later version. You may redistribute it and/or modify it
// only in compliance with the GNU General Public License.
//
// This program is distributed in the hope that it will be useful.
// However, this program is distributed AS-IS WITHOUT ANY
// WARRANTY; INCLUDING THE IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS
// FOR A PARTICULAR PURPOSE. Please see the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
//
// Nothing in the GNU General Public License or any other license to use
// the code or files shall permit you to use Tripwire's trademarks,
// service marks, or other intellectual property without Tripwire's
// prior written consent.
//
// If you have any questions, please contact Tripwire, Inc. at either
// info@tripwire.org or www.tripwire.org.
//
///////////////////////////////////////////////////////////////////////////////
// serializable.h -- the serializable interface
///////////////////////////////////////////////////////////////////////////////
#ifndef __SERIALIZABLE_H
#define __SERIALIZABLE_H
#ifndef __TYPES_H
#include "types.h"
#endif
#ifndef __TYPED_H
#include "typed.h"
#endif
class iSerializer;
// Some version documentation is in order here:
//
// Objects that derive from iSerializable do not need to worry about versions, they
// should just read and write themselves to and from the serializer.
//
// Objects that wish to implement versioning should derive themselves from iTypedSerializerable.
// They should use the IMPLEMENT_TYPEDSERIALIZABLE() macro to declare their major and minor
// version number. Neither major or minor version number can be negative and at least one
// must be greater than zero.
//
// When an object is serialized using iSerializer::WriteObject() a header will be written that
// includes the current version number will be saved in the archive by. Therefore
// iSerializable::Write() implementations do not need to worry about versioning, They need only
// write out the object in current format.
//
// When an object is read back from an archive using iSerializer::ReadObject(),
// the version of the serialized object will be read from the header and is passed to
// iSerializable::Read(). Each implementation of Read() should this passed in version.
// If the version is greater than the current version Read() should throw a eSerializer
// exception. If the version is older than the current implementation, Read() should either
// read the older format or throw an eSerializer exception.
//
// IMPORTANT: If the version is 0 (the default parameter) then Read() it should read
// in the current format of the object. This is important if Read() is called directly.
//
// In some cases it may be desirable to not incur the overhead of the serializer writing
// header information for each serialized object. In this case call iSerializable::Read() and
// iSerializable::Write() directly rather than using ReadObject() and WriteObject().
class iSerializable
{
public:
virtual void Read (iSerializer* pSerializer, int32 version = 0) = 0; // throw (eSerializer, eArchive)
virtual void Write(iSerializer* pSerializer) const = 0; // throw (eSerializer, eArchive)
// objects implement these methods to read and write themselves to a serializer.
virtual ~iSerializable() {}
};
class iTypedSerializable : public iTyped, public iSerializable
{
public:
typedef iTypedSerializable* (*CreateFunc)();
// Pointer to a function that creates an empty version of each typed serializable object
virtual int32 Version() const = 0;
// Return the current version of that this serializable object writes.
// As a convention version number should be (major_version << 16) | minor_version.
static int32 MkVersion(int16 major, int16 minor) { return (int32)(((uint32)major << 16) | (uint32)minor); }
static int16 MajorVersion(int32 version) { return (int16)((uint32)version >> 16); }
static int16 MinorVersion(int32 version) { return (int16)version; }
virtual ~iTypedSerializable() {}
};
//////////////////////////////
// convenience macros
#define DECLARE_TYPEDSERIALIZABLE() \
DECLARE_TYPED() \
public: \
static iTypedSerializable* Create(); \
virtual int32 Version() const;
#define IMPLEMENT_TYPEDSERIALIZABLE(CLASS, TYPEDSTRING, VERSION_MAJOR, VERSION_MINOR) \
IMPLEMENT_TYPED(CLASS, TYPEDSTRING) \
iTypedSerializable* CLASS::Create() \
{ \
return new CLASS; \
} \
int32 CLASS::Version() const \
{ \
return iTypedSerializable::MkVersion(VERSION_MAJOR, VERSION_MINOR); \
}
#endif // __SERIALIZABLE_H