/// <summary>
/// Loads the Handler Configuration
/// </summary>
/// <param name="context">HTTP Context</param>
/// <param name="basePath">Base Path for the Server</param>
/// <returns></returns>
protected override BaseSparqlServerConfiguration LoadConfig(HttpContext context, out string basePath)
{
// Check the Configuration File is specified
String configFile = context.Server.MapPath(ConfigurationManager.AppSettings["dotNetRDFConfig"]);
if (configFile == null)
{
throw new DotNetRdfConfigurationException("Unable to load Graph Handler Configuration as the Web.Config file does not specify a 'dotNetRDFConfig' AppSetting to specify the RDF configuration file to use");
}
IGraph g = WebConfigurationLoader.LoadConfigurationGraph(context, configFile);
// Then check there is configuration associated with the expected URI
INode objNode = WebConfigurationLoader.FindObject(g, context.Request.Url, out basePath);
this._cachePath = basePath;
if (objNode == null)
{
throw new DotNetRdfConfigurationException("Unable to load Graph Handler Configuration as the RDF configuration file does not have any configuration associated with the URI <dotnetrdf:" + context.Request.Path + "> as required");
}
// Is our Configuration already cached?
Object temp = context.Cache[basePath];
if (temp != null)
{
if (temp is BaseSparqlServerConfiguration)
{
basePath = basePath.Substring(0, basePath.Length - 1);
return((BaseSparqlServerConfiguration)temp);
}
else
{
context.Cache.Remove(basePath);
}
}
SparqlServerConfiguration config = new SparqlServerConfiguration(new WebContext(context), g, objNode);
// Finally cache the Configuration before returning it
if (config.CacheSliding)
{
context.Cache.Add(basePath, config, new System.Web.Caching.CacheDependency(configFile), System.Web.Caching.Cache.NoAbsoluteExpiration, new TimeSpan(0, config.CacheDuration, 0), System.Web.Caching.CacheItemPriority.Normal, null);
}
else
{
context.Cache.Add(basePath, config, new System.Web.Caching.CacheDependency(configFile), DateTime.Now.AddMinutes(config.CacheDuration), System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.Normal, null);
}
basePath = basePath.Substring(0, basePath.Length - 1);
return(config);
}
/// <summary>
/// Processes a request
/// </summary>
/// <param name="context">Server Context</param>
public void ProcessRequest(HttpServerContext context)
{
//Get the server options
RdfServerOptions options = context.Server.AppSettings[RdfServerOptions.ServerOptionsKey] as RdfServerOptions;
if (options == null)
{
throw new DotNetRdfConfigurationException("rdfServer Options were not found");
}
//Get the configuration graph
IGraph g = context.Server.Context[RdfServerOptions.DotNetRdfConfigKey] as IGraph;
if (g == null)
{
g = options.LoadConfigurationGraph();
if (g == null)
{
throw new DotNetRdfConfigurationException("The HTTP Server does not contain a Configuration Graph in its State Information");
}
context.Server.Context[RdfServerOptions.DotNetRdfConfigKey] = g;
}
//Generate the expected Path and try and load the Configuration using the appropriate Node
String expectedPath;
WebConfigurationLoader.FindObject(g, context.Request.Url, out expectedPath);
INode objNode = g.GetUriNode(new Uri("dotnetrdf:" + expectedPath));
if (objNode == null)
{
throw new DotNetRdfConfigurationException("The Configuration Graph does not contain a URI Node with the expected URI <dotnetrdf:" + expectedPath + ">");
}
this._config = new SparqlServerConfiguration(g, objNode);
//Dispath the request appropriately
String path = context.Request.Url.AbsolutePath;
path = path.Substring(path.LastIndexOf('/') + 1);
switch (path)
{
case "query":
this.ProcessQueryRequest(context);
break;
case "update":
this.ProcessUpdateRequest(context);
break;
case "description":
//TODO: Add Service Description support
context.Response.StatusCode = (int)HttpStatusCode.NotImplemented;
break;
default:
//TODO: Can we easily add Protocol Support or not?
//this.ProcessProtocolRequest(context);
context.Response.StatusCode = (int)HttpStatusCode.NotFound;
break;
}
}
