private IntPtr CheckCustomSearchPath(string fileName, string platformName)
{
var baseDirectory = CustomSearchPath;
if (!String.IsNullOrEmpty(baseDirectory))
{
LibraryLoaderTrace.TraceInformation("Checking custom search location '{0}' for '{1}' on platform {2}.", baseDirectory, fileName, platformName);
return(InternalLoadLibrary(baseDirectory, platformName, fileName));
}
else
{
LibraryLoaderTrace.TraceInformation("Custom search path is not defined, skipping.");
return(IntPtr.Zero);
}
}
/// <summary>
/// Special test for web applications.
/// </summary>
/// <remarks>
/// Note that this makes a couple of assumptions these being:
///
/// <list type="bullet">
/// <item>That the current application domain's location for web applications corresponds to the web applications root directory.</item>
/// <item>That the tesseract\leptonica dlls reside in the corresponding x86 or x64 directories in the bin directory under the apps root directory.</item>
/// </list>
/// </remarks>
/// <param name="fileName"></param>
/// <param name="platformName"></param>
/// <returns></returns>
private IntPtr CheckCurrentAppDomainBin(string fileName, string platformName)
{
var baseDirectory = Path.Combine(Path.GetFullPath(AppDomain.CurrentDomain.BaseDirectory), "bin");
if (Directory.Exists(baseDirectory))
{
LibraryLoaderTrace.TraceInformation("Checking current application domain's bin location '{0}' for '{1}' on platform {2}.", baseDirectory, fileName, platformName);
return(InternalLoadLibrary(baseDirectory, platformName, fileName));
}
else
{
LibraryLoaderTrace.TraceInformation("No bin directory exists under the current application domain's location, skipping.");
return(IntPtr.Zero);
}
}
public bool FreeLibrary(string fileName)
{
fileName = FixUpLibraryName(fileName);
lock (syncLock) {
if (!IsLibraryLoaded(fileName))
{
LibraryLoaderTrace.TraceWarning("Failed to free library \"{0}\" because it is not loaded", fileName);
return(false);
}
if (logic.FreeLibrary(loadedAssemblies[fileName]))
{
loadedAssemblies.Remove(fileName);
return(true);
}
return(false);
}
}
public IntPtr LoadLibrary(string fileName, string platformName = null)
{
fileName = FixUpLibraryName(fileName);
lock (syncLock) {
if (!loadedAssemblies.ContainsKey(fileName))
{
if (platformName == null)
{
platformName = SystemManager.GetPlatformName();
}
LibraryLoaderTrace.TraceInformation("Current platform: " + platformName);
IntPtr dllHandle = CheckCustomSearchPath(fileName, platformName);
if (dllHandle == IntPtr.Zero)
{
dllHandle = CheckExecutingAssemblyDomain(fileName, platformName);
}
if (dllHandle == IntPtr.Zero)
{
dllHandle = CheckCurrentAppDomain(fileName, platformName);
}
if (dllHandle == IntPtr.Zero)
{
dllHandle = CheckCurrentAppDomainBin(fileName, platformName);
}
if (dllHandle == IntPtr.Zero)
{
dllHandle = CheckWorkingDirecotry(fileName, platformName);
}
if (dllHandle != IntPtr.Zero)
{
loadedAssemblies[fileName] = dllHandle;
}
else
{
throw new DllNotFoundException(string.Format("Failed to find library \"{0}\" for platform {1}.", fileName, platformName));
}
}
return(loadedAssemblies[fileName]);
}
}
public bool FreeLibrary(IntPtr libraryHandle)
{
try {
LibraryLoaderTrace.TraceInformation("Trying to free native library with handle {0} ...", libraryHandle);
var isSuccess = WindowsFreeLibrary(libraryHandle);
if (isSuccess)
{
LibraryLoaderTrace.TraceInformation("Successfully freed native library with handle {0}.", libraryHandle);
}
else
{
LibraryLoaderTrace.TraceError("Failed to free native library with handle {0}.\r\nCheck windows event log.", libraryHandle);
}
return(isSuccess);
} catch (Exception e) {
var lastError = WindowsGetLastError();
LibraryLoaderTrace.TraceError("Failed to free native library with handle {0}.\r\nLast Error:{1}\r\nCheck inner exception and\\or windows event log.\r\nInner Exception: {2}", libraryHandle, lastError, e.ToString());
return(false);
}
}
public IntPtr LoadLibrary(string fileName)
{
var libraryHandle = IntPtr.Zero;
try {
LibraryLoaderTrace.TraceInformation("Trying to load native library \"{0}\"...", fileName);
libraryHandle = WindowsLoadLibrary(fileName);
if (libraryHandle != IntPtr.Zero)
{
LibraryLoaderTrace.TraceInformation("Successfully loaded native library \"{0}\", handle = {1}.", fileName, libraryHandle);
}
else
{
LibraryLoaderTrace.TraceError("Failed to load native library \"{0}\".\r\nCheck windows event log.", fileName);
}
} catch (Exception e) {
var lastError = WindowsGetLastError();
LibraryLoaderTrace.TraceError("Failed to load native library \"{0}\".\r\nLast Error:{1}\r\nCheck inner exception and\\or windows event log.\r\nInner Exception: {2}", fileName, lastError, e.ToString());
}
return(libraryHandle);
}
public IntPtr GetProcAddress(IntPtr libraryHandle, string functionName)
{
try {
LibraryLoaderTrace.TraceInformation("Trying to load native function \"{0}\" from the library with handle {1}...",
functionName, libraryHandle);
var functionHandle = WindowsGetProcAddress(libraryHandle, functionName);
if (functionHandle != IntPtr.Zero)
{
LibraryLoaderTrace.TraceInformation("Successfully loaded native function \"{0}\", function handle = {1}.",
functionName, functionHandle);
}
else
{
LibraryLoaderTrace.TraceError("Failed to load native function \"{0}\", function handle = {1}",
functionName, functionHandle);
}
return(functionHandle);
} catch (Exception e) {
var lastError = WindowsGetLastError();
LibraryLoaderTrace.TraceError("Failed to free native library with handle {0}.\r\nLast Error:{1}\r\nCheck inner exception and\\or windows event log.\r\nInner Exception: {2}", libraryHandle, lastError, e.ToString());
return(IntPtr.Zero);
}
}
public IntPtr GetProcAddress(IntPtr libraryHandle, string functionName)
{
UnixGetLastError(); // Clearing previous errors
LibraryLoaderTrace.TraceInformation("Trying to load native function \"{0}\" from the library with handle {1}...",
functionName, libraryHandle);
var functionHandle = UnixGetProcAddress(libraryHandle, functionName);
var errorPointer = UnixGetLastError();
if (errorPointer != IntPtr.Zero)
{
throw new Exception("dlsym: " + Marshal.PtrToStringAnsi(errorPointer));
}
if (functionHandle != IntPtr.Zero && errorPointer == IntPtr.Zero)
{
LibraryLoaderTrace.TraceInformation("Successfully loaded native function \"{0}\", function handle = {1}.",
functionName, functionHandle);
}
else
{
LibraryLoaderTrace.TraceError("Failed to load native function \"{0}\", function handle = {1}, error pointer = {2}",
functionName, functionHandle, errorPointer);
}
return(functionHandle);
}
