orcad_stream.h

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright The KiCad Developers, see AUTHORS.txt for contributors.
 *
 * Based on the dsn2kicad reference implementation and on OrCAD file format
 * documentation from the OpenOrCadParser project (MIT licensed).
 *
 * 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 3 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, see <https://www.gnu.org/licenses/>.
 */
 
#ifndef ORCAD_STREAM_H_
#define ORCAD_STREAM_H_
 
#include <cstddef>
#include <cstdint>
#include <string>
#include <vector>
 
#include <wx/string.h>

class ORCAD_STREAM
{
public:
    static constexpr uint8_t PREAMBLE[4] = { 0xFF, 0xE4, 0x5C, 0x39 };

    static constexpr size_t npos = static_cast<size_t>( -1 );
 
    ORCAD_STREAM( const void* aData, size_t aLength );
    explicit ORCAD_STREAM( const std::vector<char>& aData );
 
    // -- scalars (little-endian, bounds-checked, throw IO_ERROR on overrun) -------
 
    uint8_t  ReadU8();
    int8_t   ReadI8();
    uint16_t ReadU16();
    int16_t  ReadI16();
    uint32_t ReadU32();
    int32_t  ReadI32();
 
    // -- strings -------------------------------------------------------------------

    std::string ReadLzt();

    std::string ReadZt();
 
    // -- buffers / cursor ------------------------------------------------------------

    std::vector<uint8_t> ReadBytes( size_t aCount );

    void Skip( size_t aCount );

    void Seek( size_t aOffset ) { m_offset = aOffset; }
 
    size_t GetOffset() const { return m_offset; }
    size_t Size() const { return m_size; }

    size_t Remaining() const { return m_offset >= m_size ? 0 : m_size - m_offset; }
 
    bool AtEnd() const { return m_offset >= m_size; }

    const uint8_t* Data() const { return m_data; }
 
    // -- non-throwing lookahead ------------------------------------------------------

    int PeekU8( size_t aAhead = 0 ) const;

    bool PeekMatches( const uint8_t* aBytes, size_t aCount, size_t aAhead = 0 ) const;

    bool AtPreamble( size_t aAhead = 0 ) const;

    bool HasPreambleAt( size_t aAbsoluteOffset ) const;

    size_t FindPreamble( size_t aFrom ) const;
 
    // -- validated reads ---------------------------------------------------------------

    void Expect( const uint8_t* aBytes, size_t aCount, const wxString& aWhat );

    void ExpectByte( uint8_t aValue, const wxString& aWhat );

    void ExpectPreamble( const wxString& aWhat );

    void SkipOptionalPreambleBlock();
 
private:
    void requireBytes( size_t aCount ) const;
 
    const uint8_t* m_data;
    size_t         m_size;
    size_t         m_offset;
};
 

wxString FromOrcadString( const std::string& aText );
 
#endif // ORCAD_STREAM_H_