internal static MemoryMappedView CreateView(SafeMemoryMappedFileHandle memMappedFileHandle, MemoryMappedFileAccess access, long offset, long size) { ulong num3; ulong num = (ulong)(offset % ((long)MemoryMappedFile.GetSystemPageAllocationGranularity())); ulong num2 = ((ulong)offset) - num; if (size != 0L) { num3 = ((ulong)size) + num; } else { num3 = 0L; } if ((IntPtr.Size == 4) && (num3 > 0xffffffffL)) { throw new ArgumentOutOfRangeException("size", System.SR.GetString("ArgumentOutOfRange_CapacityLargerThanLogicalAddressSpaceNotAllowed")); } Microsoft.Win32.UnsafeNativeMethods.MEMORYSTATUSEX lpBuffer = new Microsoft.Win32.UnsafeNativeMethods.MEMORYSTATUSEX(); Microsoft.Win32.UnsafeNativeMethods.GlobalMemoryStatusEx(lpBuffer); ulong ullTotalVirtual = lpBuffer.ullTotalVirtual; if (num3 >= ullTotalVirtual) { throw new IOException(System.SR.GetString("IO_NotEnoughMemory")); } uint dwFileOffsetLow = (uint)(num2 & 0xffffffffL); uint dwFileOffsetHigh = (uint)(num2 >> 0x20); SafeMemoryMappedViewHandle address = Microsoft.Win32.UnsafeNativeMethods.MapViewOfFile(memMappedFileHandle, MemoryMappedFile.GetFileMapAccess(access), dwFileOffsetHigh, dwFileOffsetLow, new UIntPtr(num3)); if (address.IsInvalid) { System.IO.__Error.WinIOError(Marshal.GetLastWin32Error(), string.Empty); } Microsoft.Win32.UnsafeNativeMethods.MEMORY_BASIC_INFORMATION buffer = new Microsoft.Win32.UnsafeNativeMethods.MEMORY_BASIC_INFORMATION(); Microsoft.Win32.UnsafeNativeMethods.VirtualQuery(address, ref buffer, (IntPtr)Marshal.SizeOf(buffer)); ulong regionSize = (ulong)buffer.RegionSize; if ((buffer.State & 0x2000) != 0) { Microsoft.Win32.UnsafeNativeMethods.VirtualAlloc(address, (UIntPtr)regionSize, 0x1000, MemoryMappedFile.GetPageAccess(access)); int errorCode = Marshal.GetLastWin32Error(); if (address.IsInvalid) { System.IO.__Error.WinIOError(errorCode, string.Empty); } } if (size == 0L) { size = (long)(regionSize - num); } address.Initialize(((ulong)size) + num); return(new MemoryMappedView(address, (long)num, size, access)); }
internal static MemoryMappedView CreateView(SafeMemoryMappedFileHandle memMappedFileHandle, MemoryMappedFileAccess access, long offset, long size) { ulong num3; ulong num = (ulong) (offset % ((long) MemoryMappedFile.GetSystemPageAllocationGranularity())); ulong num2 = ((ulong) offset) - num; if (size != 0L) { num3 = ((ulong) size) + num; } else { num3 = 0L; } if ((IntPtr.Size == 4) && (num3 > 0xffffffffL)) { throw new ArgumentOutOfRangeException("size", System.SR.GetString("ArgumentOutOfRange_CapacityLargerThanLogicalAddressSpaceNotAllowed")); } Microsoft.Win32.UnsafeNativeMethods.MEMORYSTATUSEX lpBuffer = new Microsoft.Win32.UnsafeNativeMethods.MEMORYSTATUSEX(); Microsoft.Win32.UnsafeNativeMethods.GlobalMemoryStatusEx(lpBuffer); ulong ullTotalVirtual = lpBuffer.ullTotalVirtual; if (num3 >= ullTotalVirtual) { throw new IOException(System.SR.GetString("IO_NotEnoughMemory")); } uint dwFileOffsetLow = (uint) (num2 & 0xffffffffL); uint dwFileOffsetHigh = (uint) (num2 >> 0x20); SafeMemoryMappedViewHandle address = Microsoft.Win32.UnsafeNativeMethods.MapViewOfFile(memMappedFileHandle, MemoryMappedFile.GetFileMapAccess(access), dwFileOffsetHigh, dwFileOffsetLow, new UIntPtr(num3)); if (address.IsInvalid) { System.IO.__Error.WinIOError(Marshal.GetLastWin32Error(), string.Empty); } Microsoft.Win32.UnsafeNativeMethods.MEMORY_BASIC_INFORMATION buffer = new Microsoft.Win32.UnsafeNativeMethods.MEMORY_BASIC_INFORMATION(); Microsoft.Win32.UnsafeNativeMethods.VirtualQuery(address, ref buffer, (IntPtr) Marshal.SizeOf(buffer)); ulong regionSize = (ulong) buffer.RegionSize; if ((buffer.State & 0x2000) != 0) { Microsoft.Win32.UnsafeNativeMethods.VirtualAlloc(address, (UIntPtr) regionSize, 0x1000, MemoryMappedFile.GetPageAccess(access)); int errorCode = Marshal.GetLastWin32Error(); if (address.IsInvalid) { System.IO.__Error.WinIOError(errorCode, string.Empty); } } if (size == 0L) { size = (long) (regionSize - num); } address.Initialize(((ulong) size) + num); return new MemoryMappedView(address, (long) num, size, access); }