FIX: Web service clients regenerate serialization assemblies every time that the application runs (872800)

MORE INFORMATION

Assembly binding

The type of argument that you supply to the XmlSerializerAssemblyAttribute attribute determines the way that the serializer assembly is loaded. If the CodeBase argument is used, the serializer assembly will be loaded by using the LoadFrom method. If the AssemblyName argument is used, the serializer assembly will be loaded by using the LoadWithPartialName method. For more information about assembly loading, visit the following Microsoft Web site: If you want to install your serializer assemblies to the Global Assembly Cache (GAC), you must use the AssemblyName argument, and supply the fully qualified assembly name.

Applications that are deployed by using Smart Client methods

If the assembly that contains the proxy is loaded and is executed from the local computer, it is preferable to use the CodeBase syntax for the XmlSerializerAssemblyAttribute attribute. In this case, the serializer assembly should be deployed to the same folder as the assembly that contains the proxy. If the assembly is loaded by using the LoadFrom method over HTTP in a Smart Client deployment scenario, for example, the serialization assembly will not be correctly loaded by the XmlSerializerAssemblyAttribute attribute. This problem occurs because the proxy assembly exists in the common language runtime loader's LoadFrom context instead of the Load context, and probing does not occur. To work around this problem, use the other AssemblyName syntax that is supported by the attribute with a dummy assembly name.

[System.Xml.Serialization.XmlSerializerAssemblyAttribute(AssemblyName="LoadMySerializerAssemblyNow")]

Your application can then implement a handler for the AppDomain's AssemblyResolve event to intercept the request to load the serializer assembly and load it from the correct location.

private void Form1_Load(object sender, System.EventArgs e)
{
			AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(MyResolveEventHandler);
}
static Assembly MyResolveEventHandler(object sender, ResolveEventArgs args)
 {
			Assembly a = null;
			string serializationAssemblyPartialName = "LoadMySerializerAssemblyNow";
if (args.Name == serializationAssemblyPartialName)
	{string sSerializersDLL = "<Name Of The Serializer DLL>";
string smartDeploymentHostLocation = "<Full path location to the Serializer DLL>";
a = Assembly.LoadFrom(smartDeploymentHostLocation + sSerializersDLL);
}
			return a;
		}

Alternative pregenerator sample

The following is a more sophisticated version of the serializer pregenerator sample application. This version permits creating signed serializer assemblies. Use the following code.

namespace PreGenNS 
{
	using System;
	using System.Collections;
	using System.IO;
	using System.Reflection;
	using System.Xml.Serialization;
	using System.Text;
	using System.Globalization;
	using System.Web.Services.Protocols;
	using System.Threading;
	using System.CodeDom.Compiler;
	using System.Diagnostics;
	using System.Text.RegularExpressions;

	public class Pregen 
	{
		private static bool _verbose = true;

		
		// We use this as the standard suffix on all the serializer DLLs.
		// It must match the short name of the proxy assembly class with 
		const string SerializerSuffix = ".Serializer.dll";

		
		/// Key in the app config file with path of AssemblyInfo file.
		private const string AssemblyInfoAppKey = "AssemblyInfoFile";

		//private const string CSCCmd = "csc.exe";
		// Obtain the full path for the compiler, just in case the path is not set correctly

		private readonly string CSCCmd = System.Runtime.InteropServices.RuntimeEnvironment.RuntimeDirectory() + "csc.exe";

		public static int Main(string[] args) {		
			// Are we in a recursive call?
			//TODO: could really use a single value -- use filesToDelete...
			if (AppDomain.CurrentDomain.GetData(CallingAppDomainKey) == null) {
				return RunSlave(args);
			}

			string dllName = "";
			bool invalidUsage = false;

			if(args.Length == 1)
			{
				dllName = args[0];
			}
			else if(args.Length == 2)
			{
				if(!(args[0] == "/Q" || args[0] == "/q"))
				{
					invalidUsage = true;
				}
				else
				{
					dllName = args[1];
					_verbose = false;
				}
			}
			else 
			{
				invalidUsage = true;
			}

			if (invalidUsage)
			{
				Console.WriteLine("usage: ");
				Console.WriteLine(" pregen [/Q] assembly");
				return 1;
			}
			

			// Update Private path setting in current application domain
			if (updatePrivatePath() != 0)
			{
				return 1;
			}
			
			Pregen pregen = new Pregen();
			int rc = pregen.Run(dllName);
			//Console.Read();
			return rc;
		}


		// Reads private path settings from config file and updates appdomain.  This permits configurable probing that is needed for preserialization.
		static int updatePrivatePath()
		{
			string defaultPrivatePath = System.Configuration.ConfigurationSettings.AppSettings["PregenDefaultPrivatePath"];
			string dynamicPrivatePath = System.Configuration.ConfigurationSettings.AppSettings["PregenDynamicPrivatePath"];
			string env_PREGEN_VALUES = Environment.GetEnvironmentVariable("PREGEN_VALUES");
			string [] replacementBlocks, temp;

			if (_verbose)
				Console.WriteLine("Read PREGEN_VALUES Env Variable, Value = " + env_PREGEN_VALUES);

			//process the dynamic path if the environment variable PREGEN_VALUES is present 
			if (env_PREGEN_VALUES == null || env_PREGEN_VALUES == "")
			{
				if (defaultPrivatePath != null && defaultPrivatePath != "")
				{
					AppDomain.CurrentDomain.AppendPrivatePath(defaultPrivatePath);

					if (_verbose)
						Console.WriteLine("Appended private path with: " + defaultPrivatePath);
				}
			}
			else
			{
				if (dynamicPrivatePath != null && dynamicPrivatePath != "")
				{
					//do substitutions in dynamic path
					replacementBlocks = env_PREGEN_VALUES.ToUpper().Split(";".ToCharArray());
					dynamicPrivatePath = dynamicPrivatePath.ToUpper();

					for(int i = 0; i < replacementBlocks.Length; i++)
					{
						temp = replacementBlocks[i].Split("=".ToCharArray());
						if(temp.Length != 2)
						{
							Console.Error.WriteLine("Invalid Environment Variable format - PREGEN_VALUES");
							return 1;
						}

						dynamicPrivatePath = dynamicPrivatePath.Replace(temp[0],temp[1]);
					}
					
					AppDomain.CurrentDomain.AppendPrivatePath(dynamicPrivatePath);

					if (_verbose )
						Console.WriteLine("Appended private path with: " + dynamicPrivatePath);
				}
			}
			return 0;
		}
		
		int Run(string assemblyName) 
		{

			try 
			{
				GenerateAssembly(assemblyName);
			}
			catch (Exception e) 
			{
				if (e is ThreadAbortException || e is StackOverflowException || e is OutOfMemoryException) 
				{
					throw;
				}
				Error(e, "Error processing " + assemblyName + ": ");
				return 1;
			}
			return 0;
		}



		// Generates the serializer assembly for the proxy assembly specified
		void GenerateAssembly(string assemblyName) 
		{
			Assembly assembly = LoadAssembly(assemblyName, true);
			Type[] types = assembly.GetTypes();
			ArrayList mappings = new ArrayList();
			ArrayList importedTypes = new ArrayList();
			XmlReflectionImporter importer = new XmlReflectionImporter();

			
			//Obtain the imported serializable types
			for (int i = 0; i < types.Length; i++) 
			{
				Type type = types[i];
				if (HttpWebClientProtocol.GenerateXmlMappings(type, mappings)) 
				{
					importedTypes.Add(type);
				}
			}
			if (importedTypes.Count <= 0) {
				Console.Out.WriteLine("Assembly '{0}' does not contain any serializable types.", assembly.Location);
				return;
			}
 
			{
				Type[] serializableTypes = (Type[])importedTypes.ToArray(typeof(Type));
				XmlMapping[] allMappings = (XmlMapping[])mappings.ToArray(typeof(XmlMapping));

				bool wasError = false;
				bool gac = assembly.GlobalAssemblyCache;
				string codePath = gac ? Environment.CurrentDirectory : Path.GetDirectoryName(assembly.Location);

				//adjust compiler params
				CompilerParameters parameters = new CompilerParameters();
				parameters.GenerateInMemory = false;
				parameters.IncludeDebugInformation = false;
				parameters.TempFiles = new TempFileCollection(codePath, true);
				
				//generate the serializer
				Assembly serializer = XmlSerializer.GenerateSerializer(serializableTypes, allMappings, parameters);
				if (serializer == null) {
					Console.Out.WriteLine("Failed pregenerate serializer for '{0}'", assembly.Location);
					wasError = true;
				}
				else 
				{
					serializer = null;
				}

				// Determine whether there is an assemblyInfoFile in the config file.
				string assemblyInfoFile = System.Configuration.ConfigurationSettings.AppSettings[AssemblyInfoAppKey];
				if (assemblyInfoFile != null) { 
					if (! File.Exists(assemblyInfoFile)) {
						Console.WriteLine("ERROR: AssemblyInfo file: {0} does not exist.", assemblyInfoFile);
						wasError = true;
					}
				}

				if (!wasError) {
					// Recompile the Serializer, same options, except to include the assemblyInfo file and
					// adjust the output name.

					// We have to find 
					//		1. a .cs file (the serializer source)
					//		2. a .cmdline file (the compiler options used)
					// among the temp files from the first compile.
					
					string csFile		= null;
					string cmdlineFile	= null;

					foreach (string curFile in parameters.TempFiles ) {
						string fileNameLC = curFile.ToLower();
						if (fileNameLC.EndsWith(".cs") ) {
							csFile = curFile;
						}
						else if (fileNameLC.EndsWith(".cmdline")) {
							cmdlineFile = curFile;
						}
						//Do not care about the other files...
					}
					if (csFile == null || cmdlineFile == null) {
						Console.WriteLine("Error: needed to rebuild, but cannot find either .cs or .cmdline file\n");
						DeleteTempFiles(parameters);
						return;
					}

					// So now we have found the file and the cmdline args.  We only need run the compiled application after 
					// adjusting the parameters to include the AssemblyInfo file and to change the output.
					
					// Typical calling options to csc for this sequence are:
					//		csc /noconfig @xxx.cmdline
					// we'll change this to expand the contents of the cmdline file

					// build the right name for the target serializer.
					//TODO: we should be able to read the attribute from the proxy DLL and match our output
					// to that name.
					string serializerName = Path.GetDirectoryName(assembly.Location) + @"\" 
											+ assembly.GetName().Name + SerializerSuffix;

					string cmdLine = AdjustCmdLine(cmdlineFile, assemblyInfoFile, serializerName);

					ProcessStartInfo ps = new ProcessStartInfo(CSCCmd, cmdLine);
					ps.WindowStyle = ProcessWindowStyle.Hidden;
					Process p = Process.Start(ps);
					p.WaitForExit();
					int rc = p.ExitCode;
					if (rc > 0) {
						//TODO: put useful handling here...
						Console.WriteLine("ERROR: Compiler problem, rc = {0}", rc);
						wasError = true;
					}

					//TODO: Cannot ditch temp assembly because the assembly is now loaded.
					DeleteTempFiles(parameters);

					if (!wasError) {
						Console.Out.WriteLine("Generated Serialization Assembly Name: {0}", serializerName);
					}
					Console.Out.WriteLine("Done");
				}
			}
		}


		// Delete temporary files from a CompilerParameters list.
		private void DeleteTempFiles(CompilerParameters cp) {
			ArrayList unDeletedFiles = new ArrayList(10);
			foreach(string fileName in cp.TempFiles) {
				try {
					File.Delete(fileName);
				}
				catch(Exception) {
					unDeletedFiles.Add(fileName);
					//Console.WriteLine("Warning: Unable to delete temp file: {0}, exception={1}(\"{2}\")",
					//	Path.GetFileName(fileName), e.GetType().FullName, e.Message);
				}
			}
			if (unDeletedFiles.Count > 0) {
				// put the list into the calling appDomain's environment for later deletion
				string[] files = new string[unDeletedFiles.Count];
				unDeletedFiles.CopyTo(files);

				//TODO: should really be concatenating to any existing value -- maybe leave as an ArrayList?
				AppDomain.CurrentDomain.SetData(FilesToDeleteKey, files);
			}
		}


		/// Rebuild a commandline for csc, adding assemblyInfoFile to the end of the line and adjusting the 
		/// output file name as specified.
		private string AdjustCmdLine(string cmdlineFile, string assemblyInfoFile, string outputFile) {	
			// Obtain the text from the @ response file that is used by the Framework Serialization builder
			StreamReader file = File.OpenText(cmdlineFile);
			string cmdLine = file.ReadToEnd();
			file.Close();

			// add the assemblyInfo file at the end of the command if it was specified
			if (assemblyInfoFile != null)
				cmdLine = String.Format(@"/noconfig {0} ""{1}""", cmdLine, assemblyInfoFile);

			// replace the /OUT option with our value.
			Regex re = new Regex(@"/OUT:""[^""]+.", RegexOptions.IgnoreCase);
			cmdLine = re.Replace(cmdLine, @"/OUT:""" + outputFile + @"""");

			return cmdLine;
		}

		static Assembly LoadAssembly(string assemblyName, bool throwOnFail) 
		{
			Assembly assembly = null;
			string path = Path.GetFullPath(assemblyName).ToLower(CultureInfo.InvariantCulture);
			if (File.Exists(path)) 
			{
				assembly = Assembly.LoadFrom(path);
			}
			else 
			{
				try 
				{
					assembly = Assembly.Load(assemblyName);
				}
				catch (Exception e) 
				{
					if (e is ThreadAbortException || e is StackOverflowException || e is OutOfMemoryException) 
					{
						throw;
					}
					Error(e, "Error: ");
				}
				if (assembly == null) 
				{
					string justName = Path.GetFileNameWithoutExtension(assemblyName);
					try 
					{
						assembly = Assembly.Load(justName);
					}
					catch (Exception e) 
					{
						if (e is ThreadAbortException || e is StackOverflowException || e is OutOfMemoryException) 
						{
							throw;
						}
						Error(e, "Error: ");
					}
				}
			}
			if (assembly == null) 
			{
				if (throwOnFail)
					throw new InvalidOperationException("Cannot load assembly " + assemblyName);
				return null;
			}
			return assembly;
		}

		static void Error(Exception e, string prefix) 
		{
			Console.Error.WriteLine(prefix + e.Message);
			if (e.InnerException != null) 
			{
				Error(e.InnerException, " - ");
			}
		}

		static void Warning(Exception e) 
		{
			Console.Out.WriteLine(" - " + e.Message);
			if (e.InnerException != null) 
			{
				Warning(e.InnerException);
			}
		}

		private static AppDomain DuplicateAppDomain(AppDomain template, string newName) {
			AppDomain res = AppDomain.CreateDomain(newName, template.Evidence, template.SetupInformation);
			return res;
		}

		// keys in AppDomain properties
		private const string CallingAppDomainKey	= "__Calling_AppDomain__";
		private const string FilesToDeleteKey		= "__Files_To_Delete__";

		// Called from Main to set up and run the second copy of the program.
		// args: command-line arguments for second execution
		private static int RunSlave(string[] args) {

			// Start a copy of this program in another application domain
			AppDomain ad = DuplicateAppDomain(AppDomain.CurrentDomain, "serializerAD");
			Assembly ca = Assembly.GetExecutingAssembly();

			// set a marker so target domain knows that it is the subordinate.
			ad.SetData(CallingAppDomainKey, AppDomain.CurrentDomain.FriendlyName);
			ad.SetData(FilesToDeleteKey, new string[0]);

			int rc = ad.ExecuteAssembly(ca.Location, ca.Evidence, args);

			// Now delete any files
			string[] fileList = (string[])ad.GetData(FilesToDeleteKey);

			AppDomain.Unload(ad);

			if (fileList != null) {
				foreach(string fileName in fileList) {
					try {
						File.Delete(fileName);
					}
					catch(Exception e) {
						Console.WriteLine("Warning: Unable to delete temp file: {0}, exception={1}(\"{2}\")",
							Path.GetFileName(fileName), e.GetType().FullName, e.Message);
					}
				}
			}
			return rc;  
		}

	}
}