1 

     2 local ipairs, pairs, setmetatable, type = 

     3         ipairs, pairs, setmetatable, type;

     4 

     5 module "pubsub"

     6 

     7 local pubsub_node_mt = { __index = _M };

     8 

     9 function new_node(name)

    10 	return setmetatable({ name = name, subscribers = {} }, pubsub_node_mt);

    11 end

    12 

    13 function set_subscribers(node, subscribers_list, list_type)

    14 	local subscribers = node.subscribers;

    15 	

    16 	if list_type == "array" then

    17 		for _, jid in ipairs(subscribers_list) do

    18 			if not subscribers[jid] then

    19 				node:add_subscriber(jid);

    20 			end

    21 		end

    22 	elseif (not list_type) or list_type == "set" then

    23 		for jid in pairs(subscribers_list) do

    24 			if type(jid) == "string" then

    25 				node:add_subscriber(jid);

    26 			end

    27 		end

    28 	end

    29 end

    30 

    31 function get_subscribers(node)

    32 	return node.subscribers;

    33 end

    34 

    35 function publish(node, item, dispatcher, data)

    36 	local subscribers = node.subscribers;

    37 	for i = 1,#subscribers do

    38 		item.attr.to = subscribers[i];

    39 		dispatcher(data, item);

    40 	end

    41 end

    42 

    43 function add_subscriber(node, jid)

    44 	local subscribers = node.subscribers;

    45 	if not subscribers[jid] then

    46 		local space = #subscribers;

    47 		subscribers[space] = jid;

    48 		subscribers[jid] = space;

    49 	end

    50 end

    51 

    52 function remove_subscriber(node, subscriber)

    53 	local subscribers = node.subscribers;

    54 	if subscribers[jid] then

    55 		subscribers[subscribers[jid]] = nil;

    56 		subscribers[jid] = nil;

    57 	end

    58 end

    59 

    60 return _M;