qgswkbptr.h

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/***************************************************************************
    qgswkbptr.h
    ---------------------
    begin                : January 2014
    copyright            : (C) 2014 by Juergen E. Fischer
    email                : jef at norbit dot de
 ***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
#ifndef QGSWKBPTR_H
#define QGSWKBPTR_H
 
#include "qgis.h"
#include "qgis_core.h"
#include "qgis_sip.h"
#include "qgsexception.h"
 
#include <qpolygon.h>

#ifndef SIP_RUN
class CORE_EXPORT QgsWkbException : public QgsException
{
  public:
    QgsWkbException( QString const &what )
      : QgsException( what )
    {}
};
#endif
 

class CORE_EXPORT QgsWkbPtr
{
    mutable unsigned char *mP;
    unsigned char *mStart;
    unsigned char *mEnd;
 
    void verifyBound( int size ) const;
 
    template<typename T> void read( T &v ) const
    {
      verifyBound( sizeof v );
      memcpy( &v, mP, sizeof v );
      mP += sizeof v;
    }
 
    template<typename T> void write( T &v ) const
    {
      verifyBound( sizeof v );
      memcpy( mP, &v, sizeof v );
      mP += sizeof v;
    }
 
    void write( const QByteArray &data ) const
    {
      verifyBound( data.length() );
      memcpy( mP, data.constData(), data.length() );
      mP += data.length();
    }
 
  public:
    QgsWkbPtr( QByteArray &wkb ) SIP_SKIP;
 
    QgsWkbPtr( unsigned char *p SIP_ARRAY, int size SIP_ARRAYSIZE );
 
    inline const QgsWkbPtr &operator>>( double &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }
    inline const QgsWkbPtr &operator>>( float &r ) const SIP_SKIP
    {
      double v;
      read( v );
      r = v;
      return *this;
    }

    inline const QgsWkbPtr &operator>>( qint32 &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }

    inline const QgsWkbPtr &operator>>( qint64 &r ) const SIP_SKIP
    {
      quint32 v;
      read( v );
      r = v;
      return *this;
    }

    inline const QgsWkbPtr &operator>>( quint32 &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }

    inline const QgsWkbPtr &operator>>( char &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }

    inline const QgsWkbPtr &operator>>( Qgis::WkbType &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( double v ) SIP_SKIP
    {
      write( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( float r ) SIP_SKIP
    {
      double v = r;
      write( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( qint32 v ) SIP_SKIP
    {
      write( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( qint64 r ) SIP_SKIP
    {
      quint32 v = r;
      write( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( quint32 v ) SIP_SKIP
    {
      write( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( char v ) SIP_SKIP
    {
      write( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( Qgis::WkbType v ) SIP_SKIP
    {
      write( v );
      return *this;
    }

    inline QgsWkbPtr &operator<<( const QByteArray &data ) SIP_SKIP
    {
      write( data );
      return *this;
    }
 
    inline void operator+=( int n ) const SIP_SKIP
    {
      verifyBound( n );
      mP += n;
    }
 
    inline operator unsigned char *() const SIP_SKIP { return mP; }

    inline int size() const SIP_SKIP { return mEnd - mStart; }

    inline int remaining() const SIP_SKIP { return mEnd - mP; }

    inline int writtenSize() const SIP_SKIP { return mP - mStart; }
};

 
class CORE_EXPORT QgsConstWkbPtr
{
  protected:
    mutable unsigned char *mP;
    unsigned char *mEnd;
    mutable bool mEndianSwap;
    mutable Qgis::WkbType mWkbType;

    void verifyBound( int size ) const SIP_SKIP;

    template<typename T> void read( T &v ) const SIP_SKIP
    {
      verifyBound( sizeof v );
      memcpy( &v, mP, sizeof( v ) );
      mP += sizeof( v );
      if ( mEndianSwap )
        endian_swap( v );
    }
 
  public:
    explicit QgsConstWkbPtr( const QByteArray &wkb ) SIP_SKIP;
    QgsConstWkbPtr( const unsigned char *p SIP_ARRAY, int size SIP_ARRAYSIZE );

    Qgis::WkbType readHeader() const SIP_SKIP;
 
    inline const QgsConstWkbPtr &operator>>( double &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }
    inline const QgsConstWkbPtr &operator>>( float &r ) const SIP_SKIP
    {
      double v;
      read( v );
      r = v;
      return *this;
    }
    inline const QgsConstWkbPtr &operator>>( int &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }
    inline const QgsConstWkbPtr &operator>>( unsigned int &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }
    inline const QgsConstWkbPtr &operator>>( char &v ) const SIP_SKIP
    {
      read( v );
      return *this;
    }

    const QgsConstWkbPtr &operator>>( QPointF &point ) const SIP_SKIP;
    const QgsConstWkbPtr &operator>>( QPolygonF &points ) const SIP_SKIP;
 
    // clang-format off
    inline void operator+=( int n ) const SIP_SKIP { verifyBound( n ); mP += n; }
    // clang-format on
    inline void operator-=( int n ) const SIP_SKIP { mP -= n; }
 
    inline operator const unsigned char *() const SIP_SKIP { return mP; }

    inline int remaining() const SIP_SKIP { return mEnd - mP; }
 
  private:
    template<typename T> void endian_swap( T &value ) const SIP_SKIP
    {
      char *data = reinterpret_cast<char *>( &value );
      const std::size_t n = sizeof( value );
      const std::size_t m = n / 2;
      for ( std::size_t i = 0; i < m; ++i )
      {
        std::swap( data[i], data[n - 1 - i] );
      }
    }
};
 
#endif // QGSWKBPTR_H