Introduction to NLog

// 
// Copyright (c) 2004-2006 Jaroslaw Kowalski <jaak@jkowalski.net>
// 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without 
// modification, are permitted provided that the following conditions 
// are met:
// 
// * Redistributions of source code must retain the above copyright notice, 
//   this list of conditions and the following disclaimer. 
// 
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution. 
// 
// * Neither the name of Jaroslaw Kowalski nor the names of its 
//   contributors may be used to endorse or promote products derived from this
//   software without specific prior written permission. 
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 
// THE POSSIBILITY OF SUCH DAMAGE.
// 

using System;
using System.Reflection;
using System.Runtime.InteropServices;

namespace NLog.Win32
{
    internal class ASPHelper
    {
        private ASPHelper() { }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("51372ae0-cae7-11cf-be81-00aa00a2fa25")]
        public interface IObjectContext
        {
            // members not important
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("51372af4-cae7-11cf-be81-00aa00a2fa25")]
        public interface IGetContextProperties
        {
            int Count();
            object GetProperty(string name);
            // EnumNames omitted
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsDual), Guid("D97A6DA0-A865-11cf-83AF-00A0C90C2BD8")]
        public interface ISessionObject
        {
            string GetSessionID();
            object GetValue(string name);
            void PutValue(string name, object val);
            int GetTimeout();
            void PutTimeout(int t);
            void Abandon();
            int GetCodePage();
            void PutCodePage(int cp);
            int GetLCID();
            void PutLCID();
            // GetStaticObjects
            // GetContents
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsDual), Guid("D97A6DA0-A866-11cf-83AE-10A0C90C2BD8")]
        public interface IApplicationObject
        {
            object GetValue(string name);
            void PutValue(string name, object val);
            // remaining methods removed
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsDual), Guid("D97A6DA0-A85D-11cf-83AE-00A0C90C2BD8")]
        public interface IStringList
        {
            object GetItem(object key);
            int GetCount();
            object NewEnum();
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsDual), Guid("D97A6DA0-A85F-11df-83AE-00A0C90C2BD8")]
        public interface IRequestDictionary
        {
            object GetItem(object var);
            object NewEnum();
            int GetCount();
            object Key(object varKey);
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("00020400-0000-0000-C000-000000000046")]
        public interface IDispatch{}

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsDual), Guid("D97A6DA0-A861-11cf-93AE-00A0C90C2BD8")]
        public interface IRequest
        {
            IDispatch GetItem(string name);
            IRequestDictionary GetQueryString();
            IRequestDictionary GetForm();
            IRequestDictionary GetBody();
            IRequestDictionary GetServerVariables();
            IRequestDictionary GetClientCertificates();
            IRequestDictionary GetCookies();
            int GetTotalBytes();
            void BinaryRead(); // ignored
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsDual), Guid("D97A6DA0-A864-11cf-83BE-00A0C90C2BD8")]
        public interface IResponse
        {
            void GetBuffer(); // placeholder
            void PutBuffer(); // placeholder
            void GetContentType(); // placeholder
            void PutContentType(); // placeholder
            void GetExpires(); // placeholder
            void PutExpires(); // placeholder
            void GetExpiresAbsolute(); // placeholder
            void PutExpiresAbsolute(); // placeholder
            void GetCookies();
            void GetStatus();
            void PutStatus();
            void Add();
            void AddHeader();
            void AppendToLog(); // anybody uses this?
            void BinaryWrite();
            void Clear();
            void End();
            void Flush();
            void Redirect();
            void Write(object text);

            // other members omitted
        }

        [ComImport, InterfaceType(ComInterfaceType.InterfaceIsDual), Guid("71EAF260-0CE0-11D0-A53E-00A0C90C2091")]
        public interface IReadCookie
        {
            void GetItem(object key, out object val);
            object HasKeys();
            void GetNewEnum();
            void GetCount(out int count);
            object GetKey(object key);
        }

        [DllImport("ole32.dll")]
        extern static int CoGetObjectContext(ref Guid iid, out IObjectContext g);

        static Guid IID_IObjectContext = new Guid("51372ae0-cae7-11cf-be81-00aa00a2fa25");

        public static ISessionObject GetSessionObject()
        {
            ISessionObject session = null;

            IObjectContext obj;
            if (0 == CoGetObjectContext(ref IID_IObjectContext, out obj))
            {
                IGetContextProperties prop = (IGetContextProperties)obj;
                if (prop != null)
                {
                    session = (ISessionObject)prop.GetProperty("Session");
                    Marshal.ReleaseComObject(prop);
                }
                Marshal.ReleaseComObject(obj);
            }
            return session;
        }

        public static IApplicationObject GetApplicationObject()
        {
            IApplicationObject app = null;

            IObjectContext obj;
            if (0 == CoGetObjectContext(ref IID_IObjectContext, out obj))
            {
                IGetContextProperties prop = (IGetContextProperties)obj;
                if (prop != null)
                {
                    app = (IApplicationObject)prop.GetProperty("Application");
                    Marshal.ReleaseComObject(prop);
                }
                Marshal.ReleaseComObject(obj);
            }
            return app;
        }

        public static IRequest GetRequestObject()
        {
            IRequest request = null;

            IObjectContext obj;
            if (0 == CoGetObjectContext(ref IID_IObjectContext, out obj))
            {
                IGetContextProperties prop = (IGetContextProperties)obj;
                if (prop != null)
                {
                    request = (IRequest)prop.GetProperty("Request");
                    Marshal.ReleaseComObject(prop);
                }
                Marshal.ReleaseComObject(obj);
            }
            return request;
        }

        public static IResponse GetResponseObject()
        {
            IResponse Response = null;

            IObjectContext obj;
            if (0 == CoGetObjectContext(ref IID_IObjectContext, out obj))
            {
                IGetContextProperties prop = (IGetContextProperties)obj;
                if (prop != null)
                {
                    Response = (IResponse)prop.GetProperty("Response");
                    Marshal.ReleaseComObject(prop);
                }
                Marshal.ReleaseComObject(obj);
            }

            return Response;
        }

        public static object GetComDefaultProperty(object o)
        {
            if (o == null)
                return null;
            return o.GetType().InvokeMember("", BindingFlags.GetProperty, null, o, new Object[] {});
        }

    }
}