1 files changed, 91 insertions, 0 deletions
diff --git a/erlbal_n.erl b/erlbal_n.erl
new file mode 100644
index 0000000..fba8621
--- /dev/null
+++ b/erlbal_n.erl
@@ -0,0 +1,91 @@
+-module(erlbal_n).
+-export([make_request/2, start_bal/0, stop_bal/1, start_server/5, stop_server/2, list_servers/1]).
+
+start_server(Balancer, Node, Fun, LoadFun, INITSTATE) when is_function(Fun, 2) andalso is_function(LoadFun, 0) andalso is_list(INITSTATE) ->
+	PID = spawn(Node, fun() -> server_loop(Fun, LoadFun, INITSTATE) end),
+	Balancer ! {add_node, PID}.
+
+stop_server(Balancer, PID) ->
+	Balancer ! {del_node, PID},
+	PID ! die.
+
+list_servers(Balancer) ->
+	Balancer ! {list_nodes, self()},
+	receive Nodes -> Nodes end.
+
+server_loop(Fun, LoadFun, STATE) ->
+	receive
+		{request, From, Serverlist, ARGS} ->
+			{Ret, NEWSTATE} = Fun(ARGS, STATE),
+			From ! Ret,
+			updatestates(Serverlist, self(), NEWSTATE),
+			server_loop(Fun, LoadFun, NEWSTATE);
+		{load, From} ->
+			From ! LoadFun(),
+			server_loop(Fun, LoadFun, STATE);
+		{update, NEWSTATE} ->
+			server_loop(Fun, LoadFun, NEWSTATE);
+		die ->
+			ok
+	end.
+
+updatestates([], _, _) ->
+	ok;
+updatestates([H|T], H, NEWSTATE) ->
+	updatestates(T, H, NEWSTATE);
+updatestates([H|T], P, NEWSTATE) ->
+	H ! {update, NEWSTATE},
+	updatestates(T, P, NEWSTATE).
+
+start_bal() ->
+	spawn(fun() -> bal_loop([]) end).
+
+stop_bal(Balancer) ->
+	Balancer ! die.
+
+bal_loop(Serverlist) ->
+	receive
+		{add_node, PID} ->
+			bal_loop(Serverlist ++ [PID]);
+		{del_node, PID} ->
+			bal_loop(Serverlist -- [PID]);
+		{list_nodes, From} ->
+			From ! Serverlist,
+			bal_loop(Serverlist);
+		{request, From, ARGS} ->
+			if
+				length(Serverlist) > 0 ->
+					PID = bal_worker(Serverlist),
+					PID ! {request, From, Serverlist, ARGS},
+					bal_loop(Serverlist);
+				true ->
+					bal_loop(Serverlist)
+			end;
+		die ->
+			ok
+	end.
+
+bal_worker([H|T]) ->
+	H ! {load, self()},
+	receive
+		N ->
+			bal_worker(T, N, H)
+	end.
+bal_worker([], _, PID) ->
+	PID;
+bal_worker([H|T], Best, PID) ->
+	H ! {load, self()},
+	receive
+		N ->
+			if 
+				N > Best ->
+					bal_worker(T, N, H);
+				true ->
+					bal_worker(T, Best, PID)
+			end
+	end.
+	
+
+make_request(Balancer, ARGS) when is_list(ARGS)->
+	Balancer ! {request, self(), ARGS},
+	receive Ret -> Ret end.