.. _glossary: ========== Glossary ========== .. glossary:: event See :ref:`event`. event payload Domain object (programming language dependent) that is associated with an event. Example(C++,protocol buffers,spread): an object of type ``IplImage*`` data type the type (programming language dependent) of event payload. Example(C++,protocol buffers,spread): ``IplImage*`` for the example above wire type Container type (programming language dependent?) of serialized representation of event payload (specific for a port type) Examples * C++,protocol buffers,spread: unsigned char* * Java,xmpp: XMPP message as DOM tree wire schema Layout/structure of serialized representation of event payload Example(C++,protocol buffers,spread): specified by ``ImageMessage`` protocol buffer descriptor domain->wire converter Mechanism that transforms event payloads into data of the wire type that has an interpretation w.r.t. the wire schema. Uniquely identified by the triple 1. domain type 2. wire type 3. wire schema Example(C++,protocol buffers,spread): ``AbstractConverter?`` See :ref:`type` s for a list of well-known wire schema <-> data type mappings. local server A kind of :term:`participant` which provides methods that can be called by other :term:`participant` s. See also :term:`remote server`. wire->domain converter Similar notification :term:`transport` -specific message that contains * event meta-data * wire schema * (wire type, wire schema) representation of payload Note: does not contain domain type of event payload participant Any entity that communicates via the bus is called a participant. Typical participants are :term:`listener` s which receive :term:`event` s and :term:`informer` s which publish :term:`event` s. listener A kind of :term:`participant` which (asynchronously) receives :term:`event` s. reader A kind of :term:`participant` which *synchronously* receives :term:`event` s. See also :term:`listener`. remote server A kind of :term:`participant` which is able to call methods provided by :term:`local server` s. See also :term:`local server`. informer A kind of :term:`participant` which publishes :term:`event` s. scope Descriptor for a channel of the unified bus. The channel is itself hierarchical, hence the scope also reflects this structure. There is a string-based notation for scopes: ``/parent/sub/subsubscope/``. A scope is valid if it matches the given regular expression: ``/([a-zA-Z0-9]+/)*`` channel A communication domain participants of which exchange events in a broadcast communication style. Channels form a tree with respect to set-inclusion relations of their respective sets of participants. Channels are designated by scopes. transport TODO Spread The `Spread`_ group communication framework is one the :term:`transport` s |project| can use. Spread daemon A network server used by :term:`Spread` to coordinate communication of clients and exchange data. Usually installed under the name :samp:`{PREFIX}/sbin/spread`.