/// <summary>
///
/// </summary>
/// <param name="fileName"></param>
/// <param name="protection"></param>
/// <param name="access"></param>
/// <param name="maxSize"></param>
/// <param name="name"></param>
public MemoryMappedFile(String fileName, MapProtection protection, MapAccess access,
long maxSize, String name)
{
//try to open the mmf by name. if failed create the file and mmf.
IntPtr hFile = IntPtr.Zero;
try
{
m_hMap = Win32MapApis.OpenFileMapping((int)access, false, name);
if (m_hMap == NULL_HANDLE)
{
int desiredAccess = GENERIC_READ;
if ((protection == MapProtection.PageReadWrite) ||
(protection == MapProtection.PageWriteCopy))
{
desiredAccess |= GENERIC_WRITE;
}
hFile = Win32MapApis.CreateFile(
GetMMFDir() + fileName, desiredAccess, 0,
IntPtr.Zero, OPEN_ALWAYS, 0, IntPtr.Zero
);
if (hFile != NULL_HANDLE)
{
m_hMap = Win32MapApis.CreateFileMapping(
hFile, IntPtr.Zero, (int)protection,
0,
(int)(maxSize & 0xFFFFFFFF), name
);
if (m_hMap != NULL_HANDLE)
{
m_maxSize = maxSize;
}
else
{
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
}
}
else
{
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
}
}
}
catch (Exception Err)
{
throw Err;
}
finally
{
if (!(hFile == NULL_HANDLE))
{
Win32MapApis.CloseHandle(hFile);
}
}
}
/// <summary>
///
/// </summary>
/// <param name="FileName"></param>
/// <param name="protection"></param>
/// <param name="name"></param>
/// <param name="access"></param>
/// <returns></returns>
public bool OpenEx(string FileName, MapProtection protection, string name, MapAccess access)
{
bool RV = false;
m_hMap = Win32MapApis.OpenFileMapping((int)access, false, name);
if (m_hMap == NULL_HANDLE)
{
if (System.IO.File.Exists(GetMMFDir() + FileName))
{
long maxSize;
System.IO.FileStream stream = System.IO.File.Open(GetMMFDir() + FileName, System.IO.FileMode.Open);
maxSize = stream.Length;
stream.Close();
IntPtr hFile = INVALID_HANDLE_VALUE;
OFSTRUCT ipStruct = new OFSTRUCT();
string MMFName = GetMMFDir() + FileName;
hFile = Win32MapApis.OpenFile(MMFName,
ipStruct
, 2);
// determine file access needed
// we'll always need generic read access
int desiredAccess = GENERIC_READ;
if ((protection == MapProtection.PageReadWrite) ||
(protection == MapProtection.PageWriteCopy))
{
desiredAccess |= GENERIC_WRITE;
}
// open or create the file
// if it doesn't exist, it gets created
m_hMap = Win32MapApis.CreateFileMapping(
hFile, IntPtr.Zero, (int)protection,
(int)((maxSize >> 32) & 0xFFFFFFFF),
(int)(maxSize & 0xFFFFFFFF), name
);
// close file handle, we don't need it
if (!(hFile == NULL_HANDLE))
{
Win32MapApis.CloseHandle(hFile);
}
RV = true;
}
}
else
{
RV = true;
}
return(RV);
}
/// <summary>
///
/// </summary>
/// <param name="access"></param>
/// <param name="name"></param>
public bool Open(MapAccess access, String name)
{
bool RV = true;
try
{
m_hMap = Win32MapApis.OpenFileMapping((int)access, false, name);
if (m_hMap == NULL_HANDLE)
{
RV = false;
}
return(RV);
}
catch
{
return(RV);
}
}
