ServiceStack.HttpHandlerFactory.GetHandlerForPathInfo C# (CSharp) Method

        public static IHttpHandler GetHandlerForPathInfo(string httpMethod, string pathInfo, string requestPath, string filePath)
        {
            var appHost = HostContext.AppHost;

            var pathParts = pathInfo.TrimStart('/').Split('/');
            if (pathParts.Length == 0) return NotFoundHttpHandler;

            string contentType;
            var restPath = RestHandler.FindMatchingRestPath(httpMethod, pathInfo, out contentType);
            if (restPath != null)
                return new RestHandler { RestPath = restPath, RequestName = restPath.RequestType.GetOperationName(), ResponseContentType = contentType };

            var existingFile = pathParts[0].ToLower();
            if (WebHostRootFileNames.Contains(existingFile))
            {
                var fileExt = System.IO.Path.GetExtension(filePath);
                var isFileRequest = !string.IsNullOrEmpty(fileExt);

                if (!isFileRequest && !HostAutoRedirectsDirs)
                {
                    //If pathInfo is for Directory try again with redirect including '/' suffix
                    if (!pathInfo.EndsWith("/"))
                    {
                        var appFilePath = filePath.Substring(0, filePath.Length - requestPath.Length);
                        var redirect = Host.Handlers.StaticFileHandler.DirectoryExists(filePath, appFilePath);
                        if (redirect)
                        {
                            return new RedirectHttpHandler
                            {
                                RelativeUrl = pathInfo + "/",
                            };
                        }
                    }
                }

                //e.g. CatchAllHandler to Process Markdown files
                var catchAllHandler = GetCatchAllHandlerIfAny(httpMethod, pathInfo, filePath);
                if (catchAllHandler != null) return catchAllHandler;

                if (!isFileRequest)
                {
                    return appHost.VirtualFileSources.DirectoryExists(pathInfo)
                        ? StaticFilesHandler
                        : NotFoundHttpHandler;
                }

                return ShouldAllow(requestPath)
                    ? StaticFilesHandler
                    : ForbiddenHttpHandler;
            }

            var handler = GetCatchAllHandlerIfAny(httpMethod, pathInfo, filePath);
            if (handler != null) return handler;

            if (appHost.Config.FallbackRestPath != null)
            {
                restPath = appHost.Config.FallbackRestPath(httpMethod, pathInfo, filePath);
                if (restPath != null)
                {
                    return new RestHandler { RestPath = restPath, RequestName = restPath.RequestType.GetOperationName(), ResponseContentType = contentType };
                }
            }

            return null;
        }