---

dsMmap.h

Go to the documentation of this file.

/*
 *  $Id: dsMmap.h,v 1.9 2004/04/06 13:39:33 dsamersoff Exp $
 */ 

#ifndef dsMmap_h 
#define dsMmap_h 

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#ifdef Win32
# include <windows.h>
# include <sys/locking.h>
#else
# include <sys/file.h>
# include <sys/mman.h>
#endif

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#ifdef HAVE_IO_H
# include <io.h>
#endif


#ifdef FreeBSD
# define MAP_ANONYMOUS  MAP_ANON
#endif


#ifndef MADV_NORMAL
# define MADV_NORMAL 0
#endif

#ifndef MAP_FAILED
# define MAP_FAILED  -1
#endif

#ifndef S_IWUSR
#  define S_IWUSR 0200
#endif

#include <dsSmartException.h>
#include <dsutil.h>

DECLARE_EXCEPTION(dsMmap);

#ifdef Win32
typedef  unsigned int mode_t;
#endif


class dsMmap 
{
protected:
    int     _fd;            
    char    *_filename;
    mode_t  _mode;
    size_t  _pagesize;  // Page size as reported by system
    size_t  _pages;     // Allocated pages, need for writing

    char    *_ptr;          // Memory pointer
    size_t  _size;      // filesize in bytes
    int     _advize;    // Flags fo madvise call
    bool    _close_fd;      //Does fd need to be closed by destructor  

#ifdef Win32
    HANDLE _mhandle;
#endif

           int getPageSize();

   virtual void mapCreate(const int fd, const size_t size, const mode_t openmode = 0444, const int advize = MADV_NORMAL);
   virtual void mapDestroy(bool close_fd = false);
   virtual void mapResize(size_t new_size);
   virtual void fileResize(size_t new_size);

    
public:

    dsMmap(const char *fname, const mode_t openmode = 0444, const int advize = MADV_NORMAL);
    dsMmap(const int fd, const size_t size, const mode_t openmode = 0444, const int advize = MADV_NORMAL);
    dsMmap();
    virtual ~dsMmap();

    int fd();

    char operator[](int i){ return _ptr[i]; }
    void operator+=(int i){ mapResize(i); }
         
    operator char *(){ return _ptr; }      
    operator size_t(){ return _size;}      

    char  *ptr() { return _ptr; }      
    size_t size(){ return _size;}      

   friend class dsMmapStreambuf;
};

inline int dsMmap::fd()
{ return _fd;
}  


class dsMmapAnon: public dsMmap
{
public:
    dsMmapAnon();
    dsMmapAnon(const size_t size, const int advize = MADV_NORMAL);

    ~dsMmapAnon();


    void mapCreate(const size_t size, const int advize = MADV_NORMAL);
    void mapResize(size_t newsize);
};

#endif

---