StringDecoder.h

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#ifndef Cpl_Text_Frame_StringDecoder_h_
#define Cpl_Text_Frame_StringDecoder_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/Decoder_.h"
#include "Cpl/Text/String.h"
 
 
///
namespace Cpl {
///
namespace Text {
///
namespace Frame {
 
 
 
/** This concrete class defines an interface a Text "Decoder" that
    accepts a null terminated string as its input source. See
    Cpl::Text::Frame::Decoder for details on what is a decoder.
 */
class StringDecoder : public Decoder_
{
protected:
    /// From the last scan: start of the data being scanned
    const char*         m_startPtr;
 
    /// From the last scan: pointer to the next character AFTER the LAST character decoded
    const char*         m_endPtr;
 
    /// Input source
    const char*         m_srcPtr;
 
    /// Input source length
    int                 m_srcLen;
 
    /// SOF character
    const char          m_sof;
 
    /// EOF character
    const char          m_eof;
 
    /// Escape character
    const char          m_esc;
 
 
 
public:
    /** Constructor. The optional 'inputSource' argument points to the raw
        frame data to be decoded.  If 'inputSource' is not set at construction
        time, it MUST be set BEFORE scan() is called or a fatal error will be
        generated.
 
        NOTE: Once scan() has be called the 'inputSouce' is considered to be
              consumed and the Application must make a call to setInput()
              before calling scan() again (if not, the scan() call will fail
              - i.e. return false - with an end-of-input error).
     */
    StringDecoder( char startOfFrame, char endOfFrame, char escapeChar, const char* inputSourceAsNullTerminatedString = 0 );
 
 
 
public:
    /** This method allows the Application/consumer to change/Set the Input
        source.
     */
    virtual void setInput( const char* inputSourceAsNullTerminatedString ) noexcept;
 
    /** This method allows the Application/consumer to change/Set the Input
        source.  Note: 'sizeInBytesOfSource' does NOT include the/a null
        terminator
     */
    virtual void setInput( const char* inputSoruce, int sizeInBytesOfSource ) noexcept;
 
    /** This method return a pointer to the next character AFTER the LAST character
        decoded.  The value returned from this method is ONLY valid after a
        call to scan() and BEFORE a subsequent call to scan(), oobRead(), or 
        setInput().
     */
    virtual const char* getRemainder() const noexcept;
 
 
 
public:
    /// See Cpl::Text::Frame::Decoder
    bool scan( size_t maxSizeOfFrame, char* frame, size_t& frameSize ) noexcept;
 
 
 
protected:
    /// See Cpl::Text::Frame::Decoder_
    bool isStartOfFrame() noexcept;
 
    /// See Cpl::Text::Frame::Decoder_
    bool isEofOfFrame() noexcept;
 
    /// See Cpl::Text::Frame::Decoder_
    bool isEscapeChar() noexcept;
 
    /// See Cpl::Text::Frame::Decoder_
    bool isLegalCharacter() noexcept;
 
 
protected:
    /// See Cpl::Text::Frame::Decoder_
    bool read( void* buffer, int numBytes, int& bytesRead );
 
};
 
 
 
 
};      // end namespaces
};
};
#endif  // end header latch