mapfile.hpp

使用Qt4编写的星际译王（stardict）

#ifndef _MAPFILE_HPP_
#define _MAPFILE_HPP_

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#ifdef HAVE_MMAP
#  include <sys/types.h>
#  include <fcntl.h>
#  include <sys/mman.h>
#endif
#ifdef _WIN32
#  include <windows.h>
#endif
#include <glib.h>

class MapFile {
public:
  MapFile(void) : 
		data(NULL),
#ifdef HAVE_MMAP
		mmap_fd(-1)
#elif defined(_WIN32)
		hFile(0),
		hFileMap(0)
#endif
	{
	}
  ~MapFile();
  bool open(const char *file_name, unsigned long file_size);
  inline gchar *begin(void) { return data; }
private:
  char *data;
  unsigned long size;
#ifdef HAVE_MMAP
  int mmap_fd;
#elif defined(_WIN32)
  HANDLE hFile;
  HANDLE hFileMap;
#endif
};

inline bool MapFile::open(const char *file_name, unsigned long file_size)
{
  size=file_size;
#ifdef HAVE_MMAP
  if ((mmap_fd = ::open(file_name, O_RDONLY)) < 0) {
    //g_print("Open file %s failed!\n",fullfilename);
    return false;
  }
  data = (gchar *)mmap( NULL, file_size, PROT_READ, MAP_SHARED, mmap_fd, 0);
  if ((void *)data == (void *)(-1)) {
    //g_print("mmap file %s failed!\n",idxfilename);
    data=NULL;
    return false;
  }
#elif defined( _WIN32)
  hFile = CreateFile(file_name, GENERIC_READ, 0, NULL, OPEN_ALWAYS, 
		     FILE_ATTRIBUTE_NORMAL, 0);
  hFileMap = CreateFileMapping(hFile, NULL, PAGE_READONLY, 0,  
			       file_size, NULL);
  data = (gchar *)MapViewOfFile(hFileMap, FILE_MAP_READ, 0, 0, file_size);
#else
  gsize read_len;
  if (!g_file_get_contents(file_name, &data, &read_len, NULL))
    return false;

  if (read_len!=file_size)
    return false;		
#endif

  return true;
}

inline MapFile::~MapFile()
{
  if (!data)
    return;
#ifdef HAVE_MMAP
  munmap(data, size);
  close(mmap_fd);
#else
#  ifdef _WIN32
  UnmapViewOfFile(data);
  CloseHandle(hFileMap);
  CloseHandle(hFile);
#  else
		g_free(data);
#  endif
#endif			
}

#endif//!_MAPFILE_HPP_