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_core.h"
#include "qgswkbtypes.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 { read( v ); return *this; } SIP_SKIP
    inline const QgsWkbPtr &operator>>( float &r ) const { double v; read( v ); r = v; return *this; } SIP_SKIP
    inline const QgsWkbPtr &operator>>( int &v ) const { read( v ); return *this; } SIP_SKIP
    inline const QgsWkbPtr &operator>>( unsigned int &v ) const { read( v ); return *this; } SIP_SKIP
    inline const QgsWkbPtr &operator>>( char &v ) const { read( v ); return *this; } SIP_SKIP
    inline const QgsWkbPtr &operator>>( QgsWkbTypes::Type &v ) const { read( v ); return *this; } SIP_SKIP

    inline QgsWkbPtr &operator<<( double v ) { write( v ); return *this; } SIP_SKIP
    inline QgsWkbPtr &operator<<( float r ) { double v = r; write( v ); return *this; } SIP_SKIP
    inline QgsWkbPtr &operator<<( int v ) { write( v ); return *this; } SIP_SKIP
    inline QgsWkbPtr &operator<<( unsigned int v ) { write( v ); return *this; } SIP_SKIP
    inline QgsWkbPtr &operator<<( char v ) { write( v ); return *this; } SIP_SKIP
    inline QgsWkbPtr &operator<<( QgsWkbTypes::Type v ) { write( v ); return *this; } SIP_SKIP
    inline QgsWkbPtr &operator<<( const QByteArray &data ) { write( data ); return *this; } SIP_SKIP

    inline void operator+=( int n ) { verifyBound( n ); mP += n; } SIP_SKIP

    inline operator unsigned char *() const { return mP; } SIP_SKIP

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

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

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

class CORE_EXPORT QgsConstWkbPtr
{
  protected:
    mutable unsigned char *mP;
    unsigned char *mEnd;
    mutable bool mEndianSwap;
    mutable QgsWkbTypes::Type 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 );

    QgsWkbTypes::Type readHeader() const SIP_SKIP;

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

    virtual const QgsConstWkbPtr &operator>>( QPointF &point ) const; SIP_SKIP
    virtual const QgsConstWkbPtr &operator>>( QPolygonF &points ) const; SIP_SKIP

    inline void operator+=( int n ) { verifyBound( n ); mP += n; } SIP_SKIP
    inline void operator-=( int n ) { mP -= n; } SIP_SKIP

    inline operator const unsigned char *() const { return mP; } SIP_SKIP

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

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

#endif // QGSWKBPTR_H