mirror of
https://github.com/element-hq/synapse.git
synced 2024-11-28 07:00:51 +03:00
86 lines
3.3 KiB
ReStructuredText
86 lines
3.3 KiB
ReStructuredText
===========
|
|
Terminology
|
|
===========
|
|
|
|
A list of definitions of specific terminology used among these documents.
|
|
These terms were originally taken from the server-server documentation, and may
|
|
not currently match the exact meanings used in other places; though as a
|
|
medium-term goal we should encourage the unification of this terminology.
|
|
|
|
|
|
Terms
|
|
=====
|
|
|
|
Backfilling:
|
|
The process of synchronising historic state from one home server to another,
|
|
to backfill the event storage so that scrollback can be presented to the
|
|
client(s). (Formerly, and confusingly, called 'pagination')
|
|
|
|
Context:
|
|
A single human-level entity of interest (currently, a chat room)
|
|
|
|
EDU (Ephemeral Data Unit):
|
|
A message that relates directly to a given pair of home servers that are
|
|
exchanging it. EDUs are short-lived messages that related only to one single
|
|
pair of servers; they are not persisted for a long time and are not forwarded
|
|
on to other servers. Because of this, they have no internal ID nor previous
|
|
EDUs reference chain.
|
|
|
|
Event:
|
|
A record of activity that records a single thing that happened on to a context
|
|
(currently, a chat room). These are the "chat messages" that Synapse makes
|
|
available.
|
|
[[NOTE(paul): The current server-server implementation calls these simply
|
|
"messages" but the term is too ambiguous here; I've called them Events]]
|
|
|
|
PDU (Persistent Data Unit):
|
|
A message that relates to a single context, irrespective of the server that
|
|
is communicating it. PDUs either encode a single Event, or a single State
|
|
change. A PDU is referred to by its PDU ID; the pair of its origin server
|
|
and local reference from that server.
|
|
|
|
PDU ID:
|
|
The pair of PDU Origin and PDU Reference, that together globally uniquely
|
|
refers to a specific PDU.
|
|
|
|
PDU Origin:
|
|
The name of the origin server that generated a given PDU. This may not be the
|
|
server from which it has been received, due to the way they are copied around
|
|
from server to server. The origin always records the original server that
|
|
created it.
|
|
|
|
PDU Reference:
|
|
A local ID used to refer to a specific PDU from a given origin server. These
|
|
references are opaque at the protocol level, but may optionally have some
|
|
structured meaning within a given origin server or implementation.
|
|
|
|
Presence:
|
|
The concept of whether a user is currently online, how available they declare
|
|
they are, and so on. See also: doc/model/presence
|
|
|
|
Profile:
|
|
A set of metadata about a user, such as a display name, provided for the
|
|
benefit of other users. See also: doc/model/profiles
|
|
|
|
Room ID:
|
|
An opaque string (of as-yet undecided format) that identifies a particular
|
|
room and used in PDUs referring to it.
|
|
|
|
Room Alias:
|
|
A human-readable string of the form #name:some.domain that users can use as a
|
|
pointer to identify a room; a Directory Server will map this to its Room ID
|
|
|
|
State:
|
|
A set of metadata maintained about a Context, which is replicated among the
|
|
servers in addition to the history of Events.
|
|
|
|
User ID:
|
|
A string of the form @localpart:domain.name that identifies a user for
|
|
wire-protocol purposes. The localpart is meaningless outside of a particular
|
|
home server. This takes a human-readable form that end-users can use directly
|
|
if they so wish, avoiding the 3PIDs.
|
|
|
|
Transaction:
|
|
A message which relates to the communication between a given pair of servers.
|
|
A transaction contains possibly-empty lists of PDUs and EDUs.
|
|
|