internal MapViewStream(IntPtr baseAddress, long length,
MapProtection protection)
{
m_base = baseAddress;
m_length = length;
m_protection = protection;
m_position = 0;
m_isOpen = (baseAddress.ToInt64() > 0);
}
/// <summary>
/// Constructor used internally by MemoryMappedFile.
/// </summary>
/// <param name="baseAddress">base address where the view starts</param>
/// <param name="length">Length of view, in bytes</param>
/// <param name="protection"></param>
internal MapViewStream(IntPtr baseAddress, long length,
MapProtection protection)
{
_base = baseAddress;
_length = length;
_protection = protection;
_position = 0;
_isOpen = (baseAddress != IntPtr.Zero);
}
//! are we open?
#endregion // variables
/// <summary>
/// Constructor used internally by MemoryMappedFile.
/// </summary>
/// <param name="baseAddress">base address where the view starts</param>
/// <param name="length">Length of view, in bytes</param>
/// <param name="protection"></param>
internal MapViewStream(IntPtr baseAddress, long length,
MapProtection protection)
{
_base = baseAddress;
_length = length;
_protection = protection;
_position = 0;
IsOpen = (baseAddress != IntPtr.Zero);
}
/// <summary>
///
/// </summary>
/// <param name="fileName"></param>
/// <param name="protection"></param>
/// <param name="maxSize"></param>
/// <param name="name"></param>
public void Create(String fileName, MapProtection protection,
long maxSize, String name)
{
// open file first
IntPtr hFile = INVALID_HANDLE_VALUE;
try
{
if (fileName != null)
{
// 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
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,
(int)((maxSize >> 32) & 0xFFFFFFFF),
(int)(maxSize & 0xFFFFFFFF), name
);
}
else
{
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
}
if (m_hMap == NULL_HANDLE)
{
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="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>
/// Constructor used internally by MemoryMappedFile.
/// </summary>
/// <param name="baseAddress">base address where the view starts</param>
/// <param name="length">Length of view, in bytes</param>
/// <param name="protection"></param>
internal MapViewStream(IntPtr baseAddress, long length,
MapProtection protection)
{
_base = baseAddress;
_length = length;
_protection = protection;
_position = 0;
//UnityEngine.Debug.Log("base address " + baseAddress);
//UnityEngine.Debug.Log(baseAddress != IntPtr.Zero);
_isOpen = (baseAddress != IntPtr.Zero);
// _isOpen = true;
//UnityEngine.Debug.Log("_isOpen" + _isOpen);
}
Create(string fileName, MapProtection protection,
long maxSize, String name)
{
MemoryMappedFile map = new MemoryMappedFile();
// open file first
IntPtr hFile = INVALID_HANDLE_VALUE;
if (fileName != null)
{
// 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
hFile = Win32MapApis.CreateFile(
fileName, desiredAccess, 0,
IntPtr.Zero, OPEN_ALWAYS, 0, IntPtr.Zero
);
if (hFile == INVALID_HANDLE_VALUE)
{
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
}
// FIX: Is support neede for zero-length files!?!
}
map._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 != INVALID_HANDLE_VALUE)
{
Win32MapApis.CloseHandle(hFile);
}
if (map._hMap == NULL_HANDLE)
{
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
}
return(map);
}
public static IMemoryMappedFile Create(string fileName, long maxSize, MapProtection mapProtection)
{
#if NETFX_BUILD
// You can either be windows, linux or f****d.
if (Environment.OSVersion.Platform == PlatformID.Win32NT)
return new Win32MemoryMappedFile(fileName, maxSize, mapProtection);
#endif // NETFX_BUILD
#if MONO_BUILD
// Assume we are running in Unix under Mono,
// so we should have Mono.Posix assembly available to us
if (Environment.OSVersion.Platform == PlatformID.Unix)
return new PosixMemoryMappedFile(fileName, maxSize, mapProtection);
#endif // MONO_BUILD
throw new PlatformNotSupportedException("Only Unix and Windows platforms are supported at this time");
}
public override IntPtr MapView(MapProtection protection, long offset, long size, IntPtr desiredAddress)
{
var unixProt = MmapProts.PROT_NONE;
if (protection == MapProtection.PageRead)
unixProt = MmapProts.PROT_READ;
if (protection == MapProtection.PageReadWrite)
unixProt = MmapProts.PROT_READ | MmapProts.PROT_WRITE;
var flags = MmapFlags.MAP_FILE | MmapFlags.MAP_SHARED;
System.Console.WriteLine("Attempting to map fd={0} @ size={1}", _fd, size);
var baseAddress = Syscall.mmap(desiredAddress, (ulong) size, unixProt, flags, _fd, offset);
if (baseAddress.ToInt64() <= 0)
throw new MemoryMapException(String.Format("mmap() failed reason={0}", Mono.Unix.Native.Stdlib.GetLastError()));
_mappings.Add(baseAddress, size);
return baseAddress;
}
Create(MapProtection protection, long maxSize, string name)
{
return Create(null, protection, maxSize, name);
}
Create(string fileName, MapProtection protection,
long maxSize)
{
return(Create(fileName, protection, maxSize, null));
}
Create(string fileName, MapProtection protection)
{
return(Create(fileName, protection, -1, null));
}
Create(MapProtection protection, long maxSize, string name)
{
// Debug.Log("Create mem file " + name + " " + maxSize);
return(Create(null, protection, maxSize, name));
}
/// <summary>
/// Constructor used internally by MemoryMappedFile.
/// </summary>
/// <param name="backingFile">Preconstructed MemoryMappedFile</param>
/// <param name="mapStartIdx">Index in the backingFile at which the view starts</param>
/// <param name="mapSize">Size of the view, in bytes.</param>
/// <param name="isWriteable">True if Read/Write access is desired, False otherwise</param>
/// <param name="viewSize">The desired view size</param>
public MemoryMappedStream(IMemoryMappedFile backingFile, long mapStartIdx, long mapSize, bool isWriteable, long viewSize)
{
if (backingFile == null) {
throw new ArgumentException("backingFile is null");
}
if ((mapStartIdx < 0) || (mapStartIdx > (long)backingFile.MaxSize))
throw new ArgumentException(
String.Format("mapStartIdx is invalid. mapStartIdx=={0}, backingFile.MaxSize=={1}",
mapStartIdx, backingFile.MaxSize));
if ((mapSize < 1) || (((mapStartIdx) + mapSize) > (long)backingFile.MaxSize))
throw new ArgumentException(
String.Format("mapSize is invalid. mapStartIdx=={0}, mapSize=={1}, backingFile.MaxSize=={2}",
mapStartIdx, mapSize, backingFile.MaxSize));
if ((viewSize < MIN_VIEW_SIZE) || (viewSize > MAX_VIEW_SIZE))
throw new ArgumentException(
String.Format("viewSize is invalid. viewSize=={0}", viewSize));
_backingFile = backingFile;
_isWriteable = isWriteable;
_access = isWriteable ? MapProtection.PageReadWrite : MapProtection.PageRead;
_desiredViewSize = viewSize;
_mapStartIdx = mapStartIdx;
_mapSize = (long)mapSize;
_isOpen = true;
// Map the first view
Seek(0, SeekOrigin.Begin);
}
Create(string fileName, MapProtection protection,
long maxSize)
{
return Create(fileName, protection, maxSize, null);
}
/// <summary>
/// Create an named map object with no file backing
/// </summary>
/// <param name="protection">desired access to the
/// mapping object</param>
/// <param name="maxSize">maximum size of filemap object</param>
/// <returns>The memory mapped file instance</returns>
public static MemoryMappedFile Create(MapProtection protection, long maxSize)
{
return Create ( null, protection, maxSize, null );
}
Create(string fileName, MapProtection protection,
long maxSize, String name)
{
MemoryMappedFile map = new MemoryMappedFile();
if (!map.Is64bit && maxSize > uint.MaxValue)
{
throw new ConstraintException("32bit systems support max size of 4gb.");
}
// open file first
IntPtr hFile = INVALID_HANDLE_VALUE;
if (!string.IsNullOrEmpty(fileName))
{
if (!File.Exists(fileName))
{
throw new MMException(string.Format("MemoryMappedFile.Create - \"{0}\" does not exist ==> Unable to map file", fileName));
}
FileInfo backingFileInfo = new FileInfo(fileName);
// Get the file size and store it for later use.
map._fileSize = backingFileInfo.Length;
// Set max size if not set. Otherwise cap it.
if (maxSize == 0)
{
maxSize = backingFileInfo.Length;
}
else
{
maxSize = Math.Min(maxSize, backingFileInfo.Length);
}
if (maxSize == 0)
{
throw new MMException(string.Format("Create - \"{0}\" is zero bytes ==> Unable to map file", fileName));
}
int desiredAccess = GENERIC_READ;
int desiredShareMode = FILE_SHARE_READ;
if ((protection == MapProtection.PageReadWrite) ||
(protection == MapProtection.PageWriteCopy))
{
desiredAccess |= GENERIC_WRITE;
desiredShareMode |= FILE_SHARE_WRITE;
}
hFile = Win32MapApis.CreateFile(
fileName, desiredAccess, desiredShareMode,
IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero
);
if (hFile == INVALID_HANDLE_VALUE)
{
throw new MMException(Marshal.GetLastWin32Error());
}
map._fileName = fileName;
}
// Map the file.
map._hMap = Win32MapApis.CreateFileMapping(
hFile, IntPtr.Zero, (int)protection,
(int)((maxSize >> 32) & 0xFFFFFFFF),
(int)(maxSize & 0xFFFFFFFF), name
);
if (hFile != INVALID_HANDLE_VALUE)
{
Win32MapApis.CloseHandle(hFile);
}
if (map._hMap == NULL_HANDLE)
{
throw new MMException(Marshal.GetLastWin32Error());
}
map._protection = protection;
map._maxSize = maxSize;
return(map);
}
public Win32MemoryMappedFile(string fileName, long maxSize, MapProtection mapProtection)
: base(fileName, maxSize)
{
// open file first
var fileHandle = Win32Native.INVALID_HANDLE_VALUE;
FileInfo backingFileInfo = null;
if (!String.IsNullOrEmpty(fileName))
backingFileInfo = new FileInfo(fileName);
// Anonymous file mapping?
_isAnonymous = fileName == null;
if (String.Empty == fileName)
throw new ArgumentException("Filename must be specified");
if (maxSize == 0) {
if (_isAnonymous || !File.Exists(fileName))
throw new ArgumentException(
String.Format("Win32MemoryMappedFile.Create - \"{0}\" does not exist ==> Unable to map entire file",
fileName));
maxSize = backingFileInfo.Length;
if (maxSize == 0)
throw new ArgumentException(
string.Format("Win32MemoryMappedFile.Create - \"{0}\" is zero bytes ==> Unable to map entire file",
fileName));
}
_maxSize = maxSize;
// determine file access needed
// we'll always need generic read access
var desiredAccess = Win32FileAccess.None;
switch (mapProtection) {
case MapProtection.PageRead:
desiredAccess = Win32FileAccess.GenericRead;
break;
case MapProtection.PageReadWrite:
desiredAccess = Win32FileAccess.GenericRead | Win32FileAccess.GenericWrite;
break;
}
//string mapName;
// open or create the file
// if it doesn't exist, it gets created
if (!_isAnonymous)
{
fileHandle = Win32Native.CreateFile(
fileName, (uint)desiredAccess, (uint)(Wind32FileShare.Write | Wind32FileShare.Read),
IntPtr.Zero, (uint)Win32CreationDisposition.OpenAlways, 0, IntPtr.Zero);
if (fileHandle == Win32Native.INVALID_HANDLE_VALUE)
throw new Win32Exception(Marshal.GetLastWin32Error());
//mapName = backingFileInfo.Name;
}
else
;
//mapName = "Anonymous";
// We always create a read-write mapping object
// the individual map obtained through MapView will be able to restrict
// the access
var win32MapProtection = Win32MapProtection.PageReadOnly;
switch (mapProtection) {
case MapProtection.PageRead:
win32MapProtection = Win32MapProtection.PageReadOnly;
break;
case MapProtection.PageReadWrite:
win32MapProtection = Win32MapProtection.PageReadWrite;
break;
case MapProtection.PageWriteCopy:
win32MapProtection = Win32MapProtection.PageWriteCopy;
break;
}
_mapHandle = Win32Native.CreateFileMapping(
fileHandle, IntPtr.Zero, (int) win32MapProtection,
(int) ((maxSize >> 32) & 0xFFFFFFFF),
(int) (maxSize & 0xFFFFFFFF), null);
// close file handle, we don't need it
if (fileHandle != Win32Native.INVALID_HANDLE_VALUE)
Win32Native.CloseHandle(fileHandle);
if (_mapHandle == Win32Native.NULL_HANDLE)
throw new Win32Exception(Marshal.GetLastWin32Error());
}
public override IntPtr MapView(MapProtection protection, long offset, long size, IntPtr desiredAddress)
{
if (!IsOpen)
throw new ObjectDisposedException("Win32MemoryMappedFile already closed!");
var mapSize = new IntPtr(size);
var win32Access = Win32FileMapAccessType.Unspecified;
switch (protection) {
case MapProtection.PageRead:
win32Access = Win32FileMapAccessType.Read;
break;
case MapProtection.PageReadWrite:
win32Access = Win32FileMapAccessType.Write;
break;
case MapProtection.PageWriteCopy:
win32Access = Win32FileMapAccessType.Copy;
break;
}
var baseAddress = Win32Native.MapViewOfFileEx(
_mapHandle, win32Access,
(uint)((offset >> 32) & 0xFFFFFFFF),
(uint)(offset & 0xFFFFFFFF),
new UIntPtr((ulong) mapSize), desiredAddress);
if (baseAddress == IntPtr.Zero)
throw new Win32Exception(Marshal.GetLastWin32Error());
_mappings.Add((ulong) baseAddress, size);
return baseAddress;
}
public abstract IntPtr MapView(MapProtection protection, long offset, long size, IntPtr desiredAddress);
Create(MapProtection protection, long maxSize)
{
return Create(null, protection, maxSize, null);
}
Create(string fileName, MapProtection protection)
{
return Create(fileName, protection, 0, null);
}
/// <summary>
/// Create an unnamed map object
/// </summary>
/// <param name="fileName">name of backing file</param>
/// <param name="protection">desired access to the
/// mapping object</param>
/// <param name="maxSize">maximum size of filemap
/// object, or -1 for size of file</param>
/// <returns>The memory mapped file instance</returns>
public static MemoryMappedFile Create( string fileName, MapProtection protection,
long maxSize)
{
return Create ( fileName, protection, maxSize, null );
}
Create(string fileName, MapProtection protection,
long maxSize, String name)
{
MemoryMappedFile map = new MemoryMappedFile();
if (!map.Is64bit && maxSize > uint.MaxValue)
throw new ConstraintException("32bit systems support max size of 4gb.");
// open file first
IntPtr hFile = INVALID_HANDLE_VALUE;
if (!string.IsNullOrEmpty(fileName))
{
if (maxSize == 0)
{
if (!File.Exists(fileName))
{
throw new Exception(string.Format("Winterdom.IO.FileMap.MemoryMappedFile.Create - \"{0}\" does not exist ==> Unable to map entire file", fileName));
}
FileInfo backingFileInfo = new FileInfo(fileName);
maxSize = backingFileInfo.Length;
if (maxSize == 0)
{
throw new Exception(string.Format("Winterdom.IO.FileMap.MemoryMappedFile.Create - \"{0}\" is zero bytes ==> Unable to map entire file", fileName));
}
}
// 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
hFile = Win32MapApis.CreateFile(
fileName, desiredAccess, 0,
IntPtr.Zero, OPEN_ALWAYS, 0, IntPtr.Zero
);
if (hFile == INVALID_HANDLE_VALUE)
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
//SafeFileHandle handle = new SafeFileHandle(hFile,true);
//NTFS.Sparse.SparseFile.MarkSparse(handle);
map._fileName = fileName;
}
map._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 != INVALID_HANDLE_VALUE) Win32MapApis.CloseHandle(hFile);
if (map._hMap == NULL_HANDLE)
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
map._protection = protection;
map._maxSize = maxSize;
return map;
}
Create(MapProtection protection, long maxSize)
{
return(Create(null, protection, maxSize, null));
}
Create(string fileName, MapProtection protection,
long maxSize, String name)
{
MemoryMappedFile map = new MemoryMappedFile();
if (!map.Is64bit && maxSize > uint.MaxValue)
{
throw new ConstraintException("32bit systems support max size of 4gb.");
}
// open file first
IntPtr hFile = INVALID_HANDLE_VALUE;
if (!string.IsNullOrEmpty(fileName))
{
if (maxSize == 0)
{
if (!File.Exists(fileName))
{
throw new Exception(string.Format("Winterdom.IO.FileMap.MemoryMappedFile.Create - \"{0}\" does not exist ==> Unable to map entire file", fileName));
}
FileInfo backingFileInfo = new FileInfo(fileName);
maxSize = backingFileInfo.Length;
if (maxSize == 0)
{
throw new Exception(string.Format("Winterdom.IO.FileMap.MemoryMappedFile.Create - \"{0}\" is zero bytes ==> Unable to map entire file", fileName));
}
}
// 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
hFile = Win32MapApis.CreateFile(
fileName, desiredAccess, 0,
IntPtr.Zero, OPEN_ALWAYS, 0, IntPtr.Zero
);
if (hFile == INVALID_HANDLE_VALUE)
{
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
}
//SafeFileHandle handle = new SafeFileHandle(hFile,true);
//NTFS.Sparse.SparseFile.MarkSparse(handle);
map._fileName = fileName;
}
map._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 != INVALID_HANDLE_VALUE)
{
Win32MapApis.CloseHandle(hFile);
}
if (map._hMap == NULL_HANDLE)
{
throw new FileMapIOException(Marshal.GetHRForLastWin32Error());
}
map._protection = protection;
map._maxSize = maxSize;
return(map);
}
public static extern SafeFileHandle CreateFileMapping(SafeFileHandle hFile, IntPtr lpAttributes, MapProtection flProtect, int dwMaximumSizeHigh, int dwMaximumSizeLow, string lpName);
/// <summary>
/// Create an unnamed map object with a maximum size
/// equal to that of the file
/// </summary>
/// <param name="fileName">name of backing file</param>
/// <param name="protection">desired access to the
/// mapping object</param>
/// <returns>The memory mapped file instance</returns>
public static MemoryMappedFile Create(string fileName, MapProtection protection)
{
return Create ( fileName, protection, -1, null );
}
Create(MapProtection protection, long maxSize, string name)
{
return(Create(null, protection, maxSize, name));
}
/// <summary>
/// Create a named map object
/// </summary>
/// <param name="fileName">name of backing file, or null
/// for a pagefile-backed map</param>
/// <param name="protection">desired access to the mapping
/// object</param>
/// <param name="maxSize">maximum size of filemap object, or 0
/// for size of file</param>
/// <param name="name">name of file mapping object</param>
/// <returns>The memory mapped file instance</returns>
public static MemoryMappedFile Create( string fileName, MapProtection protection,
long maxSize, String name)
{
MemoryMappedFile map = new MemoryMappedFile();
// open file first
IntPtr hFile = INVALID_HANDLE_VALUE;
if ( fileName != null )
{
// 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
hFile = Win32MapApis.CreateFile (
fileName, desiredAccess, 0,
IntPtr.Zero, OPEN_ALWAYS, 0, IntPtr.Zero
);
if ( hFile == INVALID_HANDLE_VALUE )
throw new FileMapIOException ( Marshal.GetHRForLastWin32Error() );
// FIX: Is support neede for zero-length files!?!
}
map._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 != INVALID_HANDLE_VALUE ) Win32MapApis.CloseHandle(hFile);
if ( map._hMap == NULL_HANDLE )
throw new FileMapIOException ( Marshal.GetHRForLastWin32Error() );
return map;
}
Create(string fileName, MapProtection protection,
long maxSize, String name)
{
MemoryMappedFile map = new MemoryMappedFile();
if (!map.Is64bit && maxSize > uint.MaxValue)
{
throw new ConstraintException("32bit systems support max size of 4gb.");
}
// open file first
IntPtr hFile = INVALID_HANDLE_VALUE;
if (!string.IsNullOrEmpty(fileName))
{
if (maxSize == 0)
{
if (!File.Exists(fileName))
{
throw new MMException(string.Format("MemoryMappedFile.Create - \"{0}\" does not exist ==> Unable to map entire file", fileName));
}
FileInfo backingFileInfo = new FileInfo(fileName);
maxSize = backingFileInfo.Length;
if (maxSize == 0)
{
throw new MMException(string.Format("Create - \"{0}\" is zero bytes ==> Unable to map entire file", fileName));
}
}
int desiredAccess = GENERIC_READ;
if ((protection == MapProtection.PageReadWrite) ||
(protection == MapProtection.PageWriteCopy))
{
desiredAccess |= GENERIC_WRITE;
}
hFile = Win32MapApis.CreateFile(
fileName, desiredAccess, 0,
IntPtr.Zero, OPEN_ALWAYS, 0, IntPtr.Zero
);
if (hFile == INVALID_HANDLE_VALUE)
{
throw new MMException(Marshal.GetHRForLastWin32Error());
}
map._fileName = fileName;
}
map._hMap = Win32MapApis.CreateFileMapping(
hFile, IntPtr.Zero, (int)protection,
(int)((maxSize >> 32) & 0xFFFFFFFF),
(int)(maxSize & 0xFFFFFFFF), name
);
if (hFile != INVALID_HANDLE_VALUE)
{
Win32MapApis.CloseHandle(hFile);
}
if (map._hMap == NULL_HANDLE)
{
throw new MMException(Marshal.GetHRForLastWin32Error());
}
map._protection = protection;
map._maxSize = maxSize;
return(map);
}
