/// <summary>
/// 装载动态链接库。
/// </summary>
/// <param name="dllName">装载动态链接库的文件名称。</param>
public virtual void Load(string dllName)
{
if (IsLoaded)
{
throw new InvalidOperationException("Libaray already loaded.");
}
IntPtr dllHandle = WIN32_API.LoadLibrary(dllName);
if (dllHandle == IntPtr.Zero)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
try
{
GetAllProcAddress(dllHandle);
}
catch (Exception)
{
WIN32_API.FreeLibrary(dllHandle);
throw;
}
m_dllName = dllName;
m_dllHandle = dllHandle;
}
/// <summary>
/// 创建文件映射对象，并映射(内存)视图。
/// </summary>
/// <param name="mappingName">文件映射对象的名称，可为null/empty。</param>
/// <param name="pageAccessRights">内存页面访问权限。</param>
/// <param name="mappingAccessRights">文件映射的访问权限。</param>
/// <param name="mappingOffset">文件映射的偏移量(起始位置)。</param>
/// <param name="viewSize">文件映射的视图大小，单位：字节。</param>
protected void InternalCreate(string mappingName, WIN32_API.PageAccess pageAccessRights,
WIN32_API.FileMappingAccess mappingAccessRights, ulong mappingOffset, uint viewSize)
{
SafeFileMappingHandle handle = null;
SafeViewOfFileHandle view = null;
handle = CreateMapping(mappingName, pageAccessRights, mappingAccessRights, mappingOffset, ref viewSize);
view = WIN32_API.MapViewOfFile(handle,
mappingAccessRights,
(uint)(mappingOffset >> 32),
(uint)mappingOffset,
viewSize);
if (view.IsInvalid)
{
handle.Dispose();
handle = null;
throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
}
m_mappingName = mappingName;
m_mappingHandle = handle;
m_mappingView = view;
m_mappingOffset = mappingOffset;
m_viewSize = viewSize;
}
/// <summary>
/// 释放由DllLoader占用的资源。
/// </summary>
/// <param name="disposing">资源释放标志，为True释放所有资源；为False则仅释放非受控资源。</param>
protected virtual void Dispose(bool disposing)
{
if (m_dllHandle != IntPtr.Zero)
{
WIN32_API.FreeLibrary(m_dllHandle);
m_dllHandle = IntPtr.Zero;
}
}
/// <summary>
/// 释放文件映射视图句柄。
/// </summary>
/// <returns>
/// 释放文件映射视图句柄成功与否标志。
/// </returns>
protected override bool ReleaseHandle()
{
if (WIN32_API.UnmapViewOfFile(base.handle) != 0)
{
base.handle = IntPtr.Zero;
return(true);
}
return(false);
}
/// <summary>
/// 按照指定Win32动态链接库句柄和函数名称获取函数指针。
/// </summary>
/// <param name="dllHandle">Win32动态链接库句柄。</param>
/// <param name="procName">函数名称。</param>
/// <param name="isRequired">指定的函数是否必须存在标志。</param>
/// <returns>
/// Win32函数指针。
/// </returns>
protected IntPtr GetProcAddress(IntPtr dllHandle, string procName, bool isRequired)
{
Debug.Assert(dllHandle != IntPtr.Zero);
IntPtr procPtr = WIN32_API.GetProcAddress(dllHandle, procName);
if (procPtr == IntPtr.Zero && isRequired)
{
Win32Exception ex = new Win32Exception(Marshal.GetLastWin32Error());
string message = String.Format("Get {0} proc-address failed, {1}", procName, ex.Message);
throw new Win32Exception(ex.NativeErrorCode, message);
}
return(procPtr);
}
/// <summary>
/// 创建文件映射。
/// </summary>
/// <param name="mappingName">文件映射对象的名称。</param>
/// <param name="pageAccessRights">页面访问权限。</param>
/// <param name="mappingAccessRights">文件映射的访问权限。</param>
/// <param name="mappingOffset">文件映射的偏移量(起始位置)。</param>
/// <param name="viewSize">文件映射的视图大小。</param>
/// <exception cref="System.ComponentModel.Win32Exception">创建文件映射失败时。</exception>
protected virtual SafeFileMappingHandle CreateMapping(string mappingName, WIN32_API.PageAccess pageAccessRights,
WIN32_API.FileMappingAccess mappingAccessRights, ulong mappingOffset, ref uint viewSize)
{
SafeFileMappingHandle result = null;
result = WIN32_API.CreateFileMapping(new SafeFileHandle(WIN32_API.InvalidHandleValue, true),
IntPtr.Zero,
pageAccessRights,
0,
viewSize,
mappingName);
if (result.IsInvalid)
{
throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
}
return(result);
}
/// <summary>
/// 释放文件映射句柄。
/// </summary>
/// <returns>
/// 释放文件映射句柄成功与否标志。
/// </returns>
protected override bool ReleaseHandle()
{
return(WIN32_API.CloseHandle(base.handle) != 0);
}
/// <summary>
/// 创建文件映射。
/// </summary>
/// <param name="mappingName">文件映射对象的名称。</param>
/// <param name="pageAccessRights">页面访问权限。</param>
/// <param name="mappingAccessRights">文件映射的访问权限。</param>
/// <param name="mappingOffset">文件映射的偏移量(起始位置)。</param>
/// <param name="viewSize">[in, out]文件映射的视图大小，等于0时表示按文件实际大小取值。</param>
/// <exception cref="System.ComponentModel.Win32Exception">创建文件映射失败时。</exception>
protected override SafeFileMappingHandle CreateMapping(string mappingName, WIN32_API.PageAccess pageAccessRights,
WIN32_API.FileMappingAccess mappingAccessRights, ulong mappingOffset, ref uint viewSize)
{
SafeFileMappingHandle result = null;
WIN32_API.GenericRight genericRights = 0;
if ((m_accessRights & FileAccess.Read) == FileAccess.Read)
{
genericRights |= WIN32_API.GenericRight.GENERIC_READ;
}
if ((m_accessRights & FileAccess.Write) == FileAccess.Write)
{
genericRights |= WIN32_API.GenericRight.GENERIC_WRITE;
}
SafeFileHandle handle = null;
try
{
Debug.Assert(!String.IsNullOrEmpty(m_filePath));
handle = WIN32_API.CreateFile(m_filePath, genericRights, m_shareMode, IntPtr.Zero, m_creationMode, FileAttributes.Normal, IntPtr.Zero);
if (handle.IsInvalid)
{
throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
}
ulong actualFileSize = 0;
{
uint fileSizeHigh = 0;
uint fileSizeLow = WIN32_API.GetFileSize(handle, out fileSizeHigh);
if (fileSizeLow == uint.MaxValue)
{
throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
}
actualFileSize = (((ulong)fileSizeHigh) << 32) + fileSizeLow;
}
ulong expectedFileSize = 0;
if (viewSize == 0)
{
if (actualFileSize == 0)
{
throw new ArgumentException("The actual file size is zero, Can't set the value of MappingSize.");
}
if (actualFileSize <= mappingOffset)
{
throw new ArgumentOutOfRangeException("MappingOffset is greater than the actual file size, Can't set the value of MappingSize.");
}
if ((actualFileSize - mappingOffset) > uint.MaxValue)
{
throw new ArgumentException("The actual file size is too large to set the value of MappingSize.");
}
viewSize = (uint)(actualFileSize - mappingOffset);
expectedFileSize = actualFileSize;
}
else
{
Debug.Assert(ulong.MaxValue - mappingOffset >= viewSize);
expectedFileSize = mappingOffset + viewSize;
}
// 不需处理，创建FileMapping时，会自动扩大
//if (expectedFileSize < actualFileSize)
//{
// // Resize File
//}
result = WIN32_API.CreateFileMapping(handle,
IntPtr.Zero,
pageAccessRights,
(uint)(expectedFileSize >> 32),
(uint)expectedFileSize,
mappingName);
if (result.IsInvalid)
{
throw new System.ComponentModel.Win32Exception(Marshal.GetLastWin32Error());
}
}
catch (Exception)
{
if (handle != null && !handle.IsInvalid)
{
handle.Dispose();
handle = null;
}
throw;
}
Debug.Assert(m_fileHandle == null);
m_fileHandle = handle;
return(result);
}