4.6.5.3 corbaname URL Scheme

The corbaname URL scheme extends the capabilities of the corbaloc scheme to allow URLs to denote entries in a Naming Service. Resolving corbaname URLs does not require a Naming Service implementation in the ORB core. An example of a corbaname URL is:

corbaname:555objs.com#a/string/path/to/obj

This URL specifies that at host 555objs.com, an object of type NamingContext (with an object key of NamingService) can be found, or alternatively, that an agent running at that location will return a reference to a NamingContext. The stringified name a/string/path/to/obj is then used as the argument to the resolve operation on that NamingContext.

A corbaname URL is similar to a corbaloc URL except that a corbaname URL also contains a stringified name that identifies a binding in a naming context. The # character denotes the start of the stringified name.

The BNF syntax for the URL is listed in the following table.

Table 4-10 BNF Syntax for URL

URL Element	Format	Description
<corbaname>	= “corbaname:”<corbaloc_obj>[ “#”<string_name>]	corbaloc_obj is a portion of a corbaname URL that identifies the naming context. The syntax is identical to its use in a corbaloc URL.
<corbaloc_obj>	<obj_addr_list>[“/”<key_string>]	For a description of obj_addr_list, see Table 4-9.
<obj_addr_list>	As defined in a corbaloc URL	For a description of obj_addr_list, see Table 4-9.
<key_string>	As defined in a corbaloc URL	For a description of key_string, see Table 4-9.
<string_name>	Stringified Name | empty string	For a description of string_name, see Table 4-9.

Resolution of a corbaname URL is implemented as a simple extension to corbaloc URL processing. To illustrate the implementation, we will use the following corbaname URL:

corbaname:<corbaloc_obj>[“#”<string_name>]

The resolution process is as follows:

1. Construct a corbaloc URL of the form corbaloc::<corbaloc_obj> from the corbaname URL.
2. Convert the corbaloc URL to a naming context object reference by calling CORBA::ORB::string_to_object to obtain a CosNaming::NamingContext object.
3. Convert <string_name> to a CosNaming::Name.
4. Invoke the resolve operation on the CosNaming::NamingContext, passing the CosNaming::Name constructed.
5. The object reference returned from CosNaming::NamingContext::resolve should be returned to the caller.

By following this resolution process, you eliminate the possibility of returning an object reference for a naming context that does not exist in the Naming Service. One side effect of this approach is that it requires that stubs for the Naming Service be part of the ORB core or that there be an internal mechanism for sending the request for the resolve operation. Because of the complexity, it is recommended that stubs for the Naming Service be embedded within the ORB core.