AsciiDecoder.h

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#ifndef Cpl_Text_Frame_AsciiDecoder_h_
#define Cpl_Text_Frame_AsciiDecoder_h_
/*-----------------------------------------------------------------------------
* This file is part of the Colony.Core Project.  The Colony.Core Project is an
* open source project with a BSD type of licensing agreement.  See the license
* agreement (license.txt) in the top/ directory or on the Internet at
* http://integerfox.com/colony.core/license.txt
*
* Copyright (c) 2014-2022  John T. Taylor
*
* Redistributions of the source code must retain the above copyright notice.
*----------------------------------------------------------------------------*/
/** @file */
 
 
#include "Cpl/Text/Frame/StreamDecoder.h"
 
 
///
namespace Cpl {
///
namespace Text {
///
namespace Frame {
 
 
 
/** This concrete template class provide a basic implementation of the
    Frame::Decoder interface that uses Cpl::Io::Input stream as the input
    source.  In addition, this class only accepts ASCII characters within the
    the frame.
 
    Template args:
        BUFSIZE     Size of the internal buffer to use when reading raw
                    characters from the Input stream.
 */
template <int BUFSIZE>
class AsciiDecoder : public StreamDecoder
{
protected:
    /// SOF character
    const char      m_sof;
 
    /// EOF character
    const char      m_eof;
 
    /// Escape character
    const char      m_esc;
 
    /// Remember printable ASCII characters ONLY option
    const bool      m_restricted;
 
    /// Raw input buffer for reading characters in 'chunks' from my Input stream (i.e. minimize the calls to read())
    char            m_buffer[BUFSIZE];
 
 
public:
    /** Constructor.  If 'restrict' is set to true ONLY printable ASCII
        characters (0x20-0x7E) are accepted inside a frame.  If false, then
        all ASCII characters (0x00-0x7F) are accepted inside a frame.  When
        a illegal character is detected, it causes the Decoder's state machine
        to reset and begin searching/looking-for the next start-of-frame
        character.
     */
    AsciiDecoder( char startOfFrame, char endOfFrame, char escapeChar, bool restrict=true, Cpl::Io::Input* inputSource=0, bool blocking = true )
        :StreamDecoder( m_buffer, BUFSIZE, inputSource, blocking )
        , m_sof( startOfFrame )
        , m_eof( endOfFrame )
        , m_esc( escapeChar )
        , m_restricted( restrict )
    {
    }
 
 
protected:
    /// See Cpl::Text::Frame::Decoder_
    bool isStartOfFrame() noexcept { return *m_dataPtr == m_sof; }
 
    /// See Cpl::Text::Frame::Decoder_
    bool isEofOfFrame() noexcept { return *m_dataPtr == m_eof; }
 
    /// See Cpl::Text::Frame::Decoder_
    bool isEscapeChar() noexcept { return *m_dataPtr == m_esc; }
 
    /// See Cpl::Text::Frame::Decoder_
    bool isLegalCharacter() noexcept { return *m_dataPtr < 0x80 && ( !m_restricted || ( *m_dataPtr <= 0x7E && *m_dataPtr >= 0x20 ) ); }
};
 
 
 
 
 
};      // end namespaces
};
};
#endif  // end header latch