datasource.h

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/* This software and supporting documentation are distributed by
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 * This software is governed by the CeCILL-B license under
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 * You can  use, modify and/or redistribute the software under the
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#ifndef SOMAIO_DATASOURCE_DATASOURCE_H
#define SOMAIO_DATASOURCE_DATASOURCE_H
//--- soma-io ----------------------------------------------------------------
#include <soma-io/config/soma_config.h>
//--- cartobase --------------------------------------------------------------
#include <cartobase/smart/rcptr.h>             // declares base class RCObject
//--- system -----------------------------------------------------------------
#include <string>
//----------------------------------------------------------------------------
 
namespace soma
{

  #if defined(__osf__)
    typedef unsigned long offset_t;
  #else
    typedef unsigned long long offset_t;
  #endif

 
  class DataSource : public virtual carto::RCObject
  {
  public:
    enum Mode
      {
        Read = 1, 
        Write = 2,
        ReadWrite = 3,
      };
 
    enum IterateMode
      {
        DirectAccess = 1, 
        SequentialAccess = 2,
      };
 
    DataSource();
    virtual ~DataSource();

    int mode() const;
 
    virtual DataSource* clone() const = 0;
    virtual int iterateMode() const = 0;
    virtual bool isOpen() const = 0;
    virtual bool eof() const;
    virtual bool operator ! () const;
    virtual operator bool () const;
    virtual bool open ( int mode ) = 0;
    virtual void close() = 0;
    virtual void flush();
    virtual offset_t size() const = 0;
    virtual offset_t at() const = 0;
    virtual bool at( offset_t pos ) = 0;
    virtual bool atEnd() const;
    bool reset();
    virtual long readBlock( char * data, unsigned long maxlen ) = 0;
    virtual long writeBlock( const char * data, unsigned long len ) = 0;
    virtual int getch() = 0;
    virtual int putch( int ch ) = 0;
    virtual bool ungetch( int ch ) = 0;
    virtual bool allowsMemoryMapping() const = 0;
    virtual std::string url() const;

    static const carto::rc_ptr<DataSource> none();
  protected:
    int         _mode;
  };
 
}
 
#endif