/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   Licensed to the Apache Software Foundation (ASF) under one or more

 *   contributor license agreements. See the NOTICE file distributed

 *   with this work for additional information regarding copyright

 *   ownership. The ASF licenses this file to you under the Apache

 *   License, Version 2.0 (the "License"); you may not use this file

 *   except in compliance with the License. You may obtain a copy of

 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .

 */

#pragma once

#include <com/sun/star/uno/Sequence.hxx>

#include <assert.h>

using namespace com::sun::star::uno;

namespace io_stm

{

class MemRingBuffer

{

public:

    MemRingBuffer();

    virtual ~MemRingBuffer();

    /***

    * overwrites data at given position. Size is automatically extended, when

    * data is written beyond end.

    ***/

    /// @throws css::io::BufferSizeExceededException

    void    writeAt( sal_Int32 nPos, const Sequence<sal_Int8> &);

    /// @throws css::io::BufferSizeExceededException

    void    readAt( sal_Int32 nPos, Sequence<sal_Int8> & , sal_Int32 nBytesToRead ) const;

    sal_Int32   getSize() const noexcept;

    /// @throws css::io::BufferSizeExceededException

    void    forgetFromStart(sal_Int32 nBytesToForget);

private:

    /// @throws css::io::BufferSizeExceededException

    void resizeBuffer(sal_Int32 nMinSize);

    void checkInvariants() const {

        assert( m_nBufferLen >= 0 );

        assert( m_nOccupiedBuffer >= 0 );

        assert( m_nOccupiedBuffer <= m_nBufferLen );

        assert( m_nStart >= 0 );

        assert( 0 == m_nStart || m_nStart < m_nBufferLen );

        (void) this; // avoid loplugin:staticmethods

    }

    sal_Int8    *m_p;

    sal_Int32   m_nBufferLen;

    sal_Int32   m_nStart;

    sal_Int32   m_nOccupiedBuffer;

};

class MemFIFO :

    private MemRingBuffer

{

public:

    /// @throws css::io::BufferSizeExceededException

    void          write( const Sequence<sal_Int8> &);

    /// @throws css::io::BufferSizeExceededException

    void          read( Sequence<sal_Int8> & , sal_Int32 nBytesToRead );

    /// @throws css::io::BufferSizeExceededException

    void          skip( sal_Int32 nBytesToSkip );

    sal_Int32     getSize() const noexcept

                  { return MemRingBuffer::getSize(); }

};

}

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