// TortoiseSVN - a Windows shell extension for easy version control

// Copyright (C) 2007-2009, 2020 - TortoiseSVN

// This program is free software; you can redistribute it and/or
// modify it under 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.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  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,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
#pragma once

///////////////////////////////////////////////////////////////
// include base class
///////////////////////////////////////////////////////////////

#include "PackedIntegerOutStream.h"

///////////////////////////////////////////////////////////////
//
// CDiffOutStreamBase
//
//      enhances CPackedIntegerOutStreamBase as well as
//      CPackedDWORDOutStreamBase to store the values
//      differentially, i.e. the difference to the previous
//      value is stored (in packed format). The base value
//      for the first element is 0.
//
//      Make sure that the differences between any two values
//      don't exceed the limits defined by the respective
//      base classes.
//
///////////////////////////////////////////////////////////////

template <class Base, class V>
class CDiffOutStreamBase : public Base
{
private:

    // last value written (i.e. our diff base)

    V lastValue;

protected:

    // add data to the stream

    void Add (V value)
    {
        Base::Add (value - lastValue);
        lastValue = value;
    }

public:

    // construction / destruction: nothing special to do

    CDiffOutStreamBase ( CCacheFileOutBuffer* aBuffer
                       , SUB_STREAM_ID anID)
        : Base (aBuffer, anID)
        , lastValue (0)
    {
    }

    virtual ~CDiffOutStreamBase() {};
};

///////////////////////////////////////////////////////////////
// the two template instances
///////////////////////////////////////////////////////////////

typedef CDiffOutStreamBase< CPackedDWORDOutStreamBase
                          , DWORD> CDiffDWORDOutStreamBase;
typedef CDiffOutStreamBase< CPackedIntegerOutStreamBase
                          , int> CDiffIntegerOutStreamBase;

///////////////////////////////////////////////////////////////
//
// CDiffDWORDOutStream
//
//      instantiable sub-class of CDiffDWORDOutStreamBase.
//
///////////////////////////////////////////////////////////////

class CDiffDWORDOutStream
    : public COutStreamImplBase< CDiffDWORDOutStream
                               , CDiffDWORDOutStreamBase
                               , DIFF_DWORD_STREAM_TYPE_ID>
{
public:

    typedef COutStreamImplBase< CDiffDWORDOutStream
                              , CDiffDWORDOutStreamBase
                              , DIFF_DWORD_STREAM_TYPE_ID> TBase;

    typedef int value_type;

    // construction / destruction: nothing special to do

    CDiffDWORDOutStream ( CCacheFileOutBuffer* aBuffer
                        , SUB_STREAM_ID anID);
    virtual ~CDiffDWORDOutStream() {};

    // public Add() methods

    using TBase::Add;
};

template class COutStreamImplBase< CDiffDWORDOutStream
                                 , CDiffDWORDOutStreamBase
                                 , DIFF_DWORD_STREAM_TYPE_ID>;

///////////////////////////////////////////////////////////////
//
// CDiffIntegerOutStream
//
//      instantiable sub-class of CDiffIntegerOutStreamBase.
//
///////////////////////////////////////////////////////////////

class CDiffIntegerOutStream
    : public COutStreamImplBase< CDiffIntegerOutStream
                               , CDiffIntegerOutStreamBase
                               , DIFF_INTEGER_STREAM_TYPE_ID>
{
public:

    typedef COutStreamImplBase< CDiffIntegerOutStream
                              , CDiffIntegerOutStreamBase
                              , DIFF_INTEGER_STREAM_TYPE_ID> TBase;

    typedef int value_type;

    // construction / destruction: nothing special to do

    CDiffIntegerOutStream ( CCacheFileOutBuffer* aBuffer
                          , SUB_STREAM_ID anID);
    virtual ~CDiffIntegerOutStream() {};

    // public Add() methods

    using TBase::Add;
};

template class COutStreamImplBase< CDiffIntegerOutStream
                                 , CDiffIntegerOutStreamBase
                                 , DIFF_INTEGER_STREAM_TYPE_ID>;