nsIRDFService Interface

 Get the <i>named data source</i> corresponding to the URI. If a data
 source has been registered via <code>RegisterDataSource()</code>, that
 data source will be returned.

 If no data source is currently
 registered for the specified URI, and a data source <i>constructor</i>
 function has been registered via <code>RegisterDatasourceConstructor()</code>,
 the RDF service will call the constructor to attempt to construct a
 new data source. If construction is successful, the data source will
 be initialized via <code>nsIRDFDataSource::Init()</code>.

nsIRDFDataSource GetDataSource(in string aURI)

 Same as GetDataSource, but if a remote/XML data source needs to be
 constructed, then this method will issue a <b>blocking</b> Refresh
 call on that data source.

nsIRDFDataSource GetDataSourceBlocking(in string aURI)

 Construct an RDF literal from a PRTime.

nsIRDFDate GetDateLiteral(in long long aValue)

 Construct an RDF literal from an int.

nsIRDFInt GetIntLiteral(in long aValue)

 Construct an RDF literal from a Unicode string.

nsIRDFLiteral GetLiteral(in wstring aValue)

 Construct an RDF resource from a single-byte URI. <code>nsIRDFService</code>
 caches resources that are in-use, so multiple calls to <code>GetResource()</code>
 for the same <code>uri</code> will return identical pointers. FindResource
 is used to find out whether there already exists a resource corresponding to that url.

nsIRDFResource GetResource(in AUTF8String aURI)

 Construct an RDF resource from a Unicode URI. This is provided
 as a convenience method, allowing automatic, in-line C++
 conversion from <code>nsString</code> objects. The <code>uri</code> will
 be converted to a single-byte representation internally.

nsIRDFResource GetUnicodeResource(in AString aURI)

 Register a <i>named data source</i>. The RDF service will call
 <code>nsIRDFDataSource::GetURI()</code> to determine the URI under
 which to register the data source.

 @note that the data source will <i>not</i> be refcounted by the
 RDF service! The assumption is that an RDF data source
 registers with the service once it is initialized (via
 <code>nsIRDFDataSource::Init()</code>), and unregisters when the
 last reference to the data source is released.

void RegisterDataSource(in nsIRDFDataSource aDataSource, in boolean aReplace)

 Registers a resource with the RDF system, making it unique w.r.t.
 GetResource.

 An implementation of nsIRDFResource should call this in its
 Init() method if it wishes the resource to be globally unique
 (which is usually the case).

 @note that the resource will <i>not</i> be ref-counted by the
 RDF service: the assumption is that the resource implementation
 will call nsIRDFService::UnregisterResource() when the last
 reference to the resource is released.

 @note that the nsIRDFService implementation may choose to
 maintain a reference to the resource's URI; therefore, the
 resource implementation should ensure that the resource's URI
 (accessible via nsIRDFResource::GetValue(const char* *aURI)) is
 valid before calling RegisterResource(). Furthermore, the
 resource implementation should ensure that this pointer
 <i>remains</i> valid for the lifetime of the resource. (The
 implementation of the resource cache in nsIRDFService uses the
 URI maintained "internally" in the resource as a key into the
 cache rather than copying the resource URI itself.)

void RegisterResource(in nsIRDFResource aResource, in boolean aReplace)

 Unregister a <i>named data source</i>. The RDF service will call
 <code>nsIRDFDataSource::GetURI()</code> to determine the URI under which the
 data source was registered.

void UnregisterDataSource(in nsIRDFDataSource aDataSource)

 Called to notify the resource manager that a resource is no
 longer in use. This method should only be called from the
 destructor of a "custom" resource implementation to notify the
 RDF service that the last reference to the resource has been
 released, so the resource is no longer valid.

 @note As mentioned in nsIRDFResourceFactory::CreateResource(),
 the RDF service will use the result of
 nsIRDFResource::GetValue() as a key into its cache. For this
 reason, you must always un-cache the resource <b>before</b>
 releasing the storage for the <code>const char*</code> URI.

void UnregisterResource(in nsIRDFResource aResource)

 Construct an RDF literal from a data blob

[noscript] nsIRDFBlob getBlobLiteral(in const_octet_ptr aValue, in long aLength)