View Source nova_pubsub (nova v0.9.23)
Pubsub system for Nova. It uses the pg/pg2 module.
Pubsub subsystem is started with Nova and does not need any additional configuration. It uses the pg/pg2 module depending on the version of OTP. It provides a simple way of distributing messages to a large set of receivers and exposes a simple set of functions for doing that.
A simple example of how to use pubsub in a ping/pong inspired game engine:
-module(test_module). -export([player1/0, player2/0, start_game/0]).
player1() -> spawn(fun() -> nova_pubsub:join(game_of_pong), game_loop(1, "pong", "ping").
player2() -> spawn(fun() -> nova_pubsub:join(game_of_pong), game_loop(2, "ping", "pong").
game_loop(Player, ExpectedMessage, Smash) -> receive ExpectedMessage -> io:format("Player ~d received ~s and returning ~s~n", [Player, ExpectedMessage, Smash]), nova_pubsub:broadcast(game_of_pong, "match1", Smash), game_loop(Player, ExpectedMessage, Smash); _ -> game_loop(Player, ExpectedMessage, Smash) end.Summary
Functions
Broadcasts a message to all members of a channel. Topic is specified to differentiate messages within the same channel.
Works the same way as get_members/1 but returns only members on the same node.
Returns all members for a given channel
Joining a channel with the calling process. Always returns ok
Same as join/1 but with a specified process.
Leaves a channnel. Will return ok on success and not_joined if the calling process were not part of the channel.
Same as leave/1 but with a specified process.
Works in the same way as broadcast/3 but only for members in the same node.
Functions
-spec broadcast(Channel :: atom(), Topic :: list() | binary(), Message :: any()) -> ok.
-spec get_local_members(Channel :: atom()) -> [pid()].
-spec get_members(Channel :: atom()) -> [pid()].
-spec join(Channel :: atom()) -> ok.
-spec join(Channel :: atom(), Pid :: pid()) -> ok.
-spec leave(Channel :: atom()) -> ok | not_joined.
-spec leave(Channel :: atom(), Pid :: pid()) -> ok | not_joined.
-spec local_broadcast(Channel :: atom(), Topic :: list() | binary(), Message :: any()) -> ok.
-spec start() -> ok.