STXXL (GIT-copy)

#ifndef BOOSTFD_FILE_H_
#define BOOSTFD_FILE_H_

/***************************************************************************
 *            boostfd_file.h
 *  File implementation based on boost::iostreams::file_decriptor
 *  Thu Oct 19 14:01:00 2006
 *  Copyright  2006  Roman Dementiev
 *  
 ****************************************************************************/

#include "iobase.h"

#ifdef STXXL_BOOST_CONFIG // if boost is available

#include <boost/iostreams/device/file_descriptor.hpp>

__STXXL_BEGIN_NAMESPACE

  //! \addtogroup fileimpl
  //! \{

  class boostfd_request;

  //! \brief Implementation based on boost::iostreams::file_decriptor
  class boostfd_file: public file
  {
  public:
    typedef boost::iostreams::file_descriptor fd_type;
  protected:
    fd_type file_des;
    int mode_;
  private:
    boostfd_file();
  public:
    boostfd_file(const std::string & filename, int mode, int disk = -1);
    fd_type get_file_des() const;
    ~boostfd_file();
    stxxl::int64 size ();
    void set_size(stxxl::int64 newsize);
    request_ptr aread(
        void *buffer, 
        stxxl::int64 pos, 
        size_t bytes,
        completion_handler on_cmpl);
    request_ptr awrite(
        void *buffer, 
        stxxl::int64 pos,
        size_t bytes,
        completion_handler on_cmpl);
  };

  //! \brief Implementation based on boost::iostreams::file_decriptor
  class boostfd_request:public request
  {
    friend class boostfd_file;
  protected:
    // states of request
    enum { OP = 0, DONE = 1, READY2DIE = 2 }; // OP - operating, DONE - request served, 
                                              // READY2DIE - can be destroyed
    
    state _state;
    #ifdef STXXL_BOOST_THREADS
    boost::mutex waiters_mutex;
    #else
    mutex waiters_mutex;
    #endif
    std::set < onoff_switch * > waiters;

    boostfd_request (
        boostfd_file * f, 
        void * buf, 
        stxxl::int64 off,
        size_t b, 
        request_type t,
        completion_handler on_cmpl);

    bool add_waiter (onoff_switch * sw);
    void delete_waiter (onoff_switch * sw);
    int nwaiters (); // returns the number of waiters
    void check_aligning ();
    void serve ();
    
    // Following methods are declared but not implemented 
    // intentionnaly to forbid their usage
    boostfd_request(const boostfd_request &);
    boostfd_request & operator=(const boostfd_request &);
    boostfd_request();
    
  public:
    virtual ~boostfd_request ();
    void wait ();
    bool poll();
    const char *io_type ();
    
  };
  
  //! \}

__STXXL_END_NAMESPACE

#endif // BOOST_VERSION


#endif /*BOOSTFD_FILE_H_*/