OSF DCE Application Development Guide--Introduction and Style Guide

Using the DCE Name Service
applications normally access CDS through NSI. Applications can get full access to CDS,
if necessary, by using the XDS interface.
5.4.1 CDSEntries
NSI uses a subset of the many possible kinds of CDS entry in order to accomplish its
tasks. CDS entries are characterized by the CDS attributes they have; each entry can
have one or more such attributes. Each separate attribute defines that entry’s ability to
contain one or more items of a particular kind of simple or complex information.
The name service creates and uses CDS entries that use only the following four
attributes:
binding The entry has a field that can contain one or more sets of binding
information. When the field is read, a binding handle that contains the
necessary information from one of these sets is returned, in no particular
order.
object The entry has a field that can contain one or more object UUIDs. When
the field is read, one of the UUIDs is returned, in no particular order.
group The entry has a field that can contain a pool of one or more references to
other (independently existing) NSI entries; each time the field is read,
one of these entries is returned. Different entries are returned on
successive reads, but the order of return is undefined.
Note that the other NSI entries referred to in the group can themselves be
server or group entries. As a result, the act of reading from a group
attribute can, depending on the actual API routine called, lead to a series
of nested operations. Any nesting is transparent to the client application,
however, which seems to perform a simple read and to receive the
contents of a single entry in return.
profile The entry has a field that can contain one or more prioritized elements,
each of which consists of a reference to another (independently existing)
NSI entry. When the field is read, the elements are read in a specified
order. The entry referred to in the element may itself be a server or a
group or a profile. As a result, any element may in fact, depending on
the actual API routine called, resolve on access to a nested path of
referred-to entries. As with group entries, this is transparent to the client
application.
Although a single entry could contain both group and profile attributes (and for that
matter, binding and object attributes as well), it is not a good idea to mix attributes in this
way because the results of importing (reading) from such an entry are too indeterminate.
The typical name service entries are as follows:
server entry
Contains a binding and an object attribute, making it suitable for
containing the necessary binding information for a single server.
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