FileScanner.h

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#ifndef OSMSCOUT_FILESCANNER_H
#define OSMSCOUT_FILESCANNER_H
 
/*
  This source is part of the libosmscout library
  Copyright (C) 2009  Tim Teulings
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  This library 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
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
*/
 
#include <cstdio>
#include <string>
#include <tuple>
#include <vector>
 
#include <osmscout/lib/CoreImportExport.h>
#include <osmscout/lib/CoreFeatures.h>
 
#include <osmscout/GeoCoord.h>
#include <osmscout/ObjectRef.h>
#include <osmscout/Point.h>
#include <osmscout/OSMScoutTypes.h>
 
#include <osmscout/util/Color.h>
#include <osmscout/util/Exception.h>
#include <osmscout/util/GeoBox.h>
#include <osmscout/util/Geometry.h>
 
#if defined(_WIN32)
  #include <windows.h>
  #undef max
  #undef min
#endif
 
namespace osmscout {

  class OSMSCOUT_API FileScanner CLASS_FINAL
  {
  public:
    enum Mode
    {
      Sequential,
      FastRandom,
      LowMemRandom,
      Normal
    };
 
  private:
    std::string  filename;            
    std::FILE    *file=nullptr;       
    mutable bool hasError=true;       
 
    // For mmap usage
    char         *mmap=nullptr;       
    FileOffset   size=0;              
    FileOffset   offset=0;            
 
    // For std::vector<GeoCoord> loading
    uint8_t      *byteBuffer=nullptr; 
    size_t       byteBufferSize=0;    
 
    // For Windows mmap usage
#if defined(__WIN32__) || defined(WIN32)
    HANDLE       mmfHandle=0;
#endif
 
  private:
    void AssureByteBufferSize(size_t size);
    void FreeBuffer();

    char* ReadInternal(size_t bytes);

    GeoCoord CreateCoord(const uint32_t &latDat,
                                const uint32_t &lonDat)
    {
#ifndef NDEBUG
      if (latDat > maxRawCoordValue ||
          lonDat > maxRawCoordValue){
        hasError=true;
        throw IOException(filename,"Cannot read coordinate","Coordinate is not normalised");
      }
#endif
 
      return {latDat/latConversionFactor-90.0,
              lonDat/lonConversionFactor-180.0};
    }

    void SetCoord(const uint32_t &latDat,
                         const uint32_t &lonDat,
                         Point &point)
    {
#ifndef NDEBUG
      if (latDat > maxRawCoordValue ||
          lonDat > maxRawCoordValue){
        hasError=true;
        throw IOException(filename,"Cannot read coordinate","Coordinate is not normalised");
      }
#endif
 
      point.SetCoord(GeoCoord(latDat/latConversionFactor-90.0,
                              lonDat/lonConversionFactor-180.0));
    }

    bool ConvertBool(const char &value)
    {
#ifndef NDEBUG
      if (value != 0 && value != 1){
        hasError=true;
        throw IOException(filename,"Cannot read bool","Bool value is not normalised");
      }
#endif
      return value!=0;
    }
 
  public:
    FileScanner() = default;
    ~FileScanner();
 
    void Open(const std::string& filename,
              Mode mode,
              bool useMmap);
    void Close();
    void CloseFailsafe();
 
    bool IsOpen() const
    {
      return file!=nullptr;
    }
 
    bool IsEOF() const;
 
     bool HasError() const
    {
      return file==nullptr || hasError;
    }
 
    std::string GetFilename() const;
 
    void GotoBegin();
    void SetPos(FileOffset pos);
    FileOffset GetPos() const;
 
    void Read(char* buffer, size_t bytes);
 
    std::string ReadString();
 
    bool ReadBool();
 
    std::byte ReadByte();
 
    int8_t ReadInt8();
    int16_t ReadInt16();
    int32_t ReadInt32();
    int64_t ReadInt64();
 
    uint8_t ReadUInt8();
    uint16_t ReadUInt16();
    uint32_t ReadUInt32();
    uint64_t ReadUInt64();
 
    uint16_t Read(size_t bytes);
    uint32_t ReadUInt32(size_t bytes);
    uint64_t ReadUInt64(size_t bytes);
 
    ObjectFileRef ReadObjectFileRef();
 
    Color ReadColor();
 
    FileOffset ReadFileOffset();
    FileOffset ReadFileOffset(size_t bytes);
 
    int16_t ReadInt16Number();
    int32_t ReadInt32Number();
    int64_t ReadInt64Number();
 
    uint16_t ReadUInt16Number();
    uint32_t ReadUInt32Number();
    uint64_t ReadUInt64Number();
 
    GeoCoord ReadCoord();
    std::tuple<GeoCoord,bool> ReadConditionalCoord();

    void Read(std::vector<Point>& nodes,
              std::vector<SegmentGeoBox> &segments,
              GeoBox &bbox,
              bool readIds);
 
    GeoBox ReadBox();
 
    TypeId ReadTypeId(uint8_t maxBytes);
 
    std::vector<ObjectFileRef> ReadObjectFileRefs(size_t count);
  };

  class OSMSCOUT_API ObjectFileRefStreamReader
  {
  private:
    FileScanner& reader;
    FileOffset   lastFileOffset=0;
 
  public:
    explicit ObjectFileRefStreamReader(FileScanner& reader);
 
    void Reset();
 
    void Read(ObjectFileRef& ref);
  };
 
}
 
#endif