Add timezone server basics with some tests

src/qdate_srv.erl

@@ -0,0 +1,114 @@
+-module(qdate_srv).
+-behaviour(gen_server).
+
+-define(SRV, ?MODULE).
+
+-export([
+	start_link/0,
+	init/1,
+	handle_call/3,
+	handle_cast/2,
+	handle_info/2,
+	code_change/3,
+	terminate/2
+]).
+
+-export([
+	set_timezone/1,
+	set_timezone/2,
+
+	get_timezone/0,
+	get_timezone/1,
+
+	clear_timezone/0,
+	clear_timezone/1
+
+%%	register_parser/1,
+%%	register_parser/2,
+%%	
+%%	deregister_parsers/0,
+%%	deregister_parsers/1,
+%%
+%%	register_format/1,
+%%	register_format/2,
+%%
+%%	deregister_format/0,
+%%	deregister_format/1
+]).
+
+%% PUBLIC API FUNCTIONS
+
+start_link() ->
+	gen_server:start_link({local, ?SRV}, ?MODULE, [], []).
+
+set_timezone(TZ) ->
+	set_timezone(self(),TZ).
+
+set_timezone(Key,TZ) ->
+	gen_server:call(?SRV,{set_timezone,Key,TZ}).
+
+get_timezone() ->
+	get_timezone(self()).
+
+get_timezone(Key) ->
+	gen_server:call(?SRV,{get_timezone,Key}).
+
+clear_timezone() ->
+	clear_timezone(self()).
+
+clear_timezone(Key) ->
+	gen_server:call(?SRV, {clear_timezone, Key}).
+
+%% SERVER FUNCTIONS
+
+-record(state, {tz, parsers, formats}).
+
+init(_) ->
+	State = #state{tz=dict:new(),parsers=dict:new(),formats=dict:new()},
+	{ok, State}.
+
+handle_cast(_,State) ->
+	{noreply, State}.
+
+handle_info({'DOWN', MonitorRef, process, Pid, _Reason}, State) ->
+	erlang:demonitor(MonitorRef),
+	NewTZ = dict:erase(Pid, State#state.tz),
+	NewParsers = dict:erase(Pid, State#state.parsers),
+	NewFormats = dict:erase(Pid, State#state.formats),
+	NewState = State#state{tz=NewTZ, parsers=NewParsers, formats=NewFormats},	
+	{noreply, NewState };
+handle_info(_, State) ->
+	{noreply, State}.
+
+handle_call({set_timezone,Key,TZ}, _From, State) ->
+	monitor_if_pid(Key),
+	NewTZ = dict:store(Key, TZ, State#state.tz),
+	NewState = State#state{tz=NewTZ},
+	{reply, ok, NewState};
+handle_call({clear_timezone,Key},_From, State) ->
+	NewTZ = dict:erase(Key, State#state.tz),
+	NewState = State#state{tz=NewTZ},
+	{reply, ok, NewState};
+handle_call({get_timezone,Key},_From, State) ->
+	Reply = case dict:find(Key, State#state.tz) of
+		error -> undefined;
+		{ok, Value} -> Value
+	end,
+	{reply, Reply, State}.
+%% handle_call({register_parser,Key,Parser}) ->
+%% handle_call({deregister_parsers,Key}) ->
+%% handle_call({register_format,Key,Format}) ->
+%% handle_call({deregister_formats,Key}) ->
+
+terminate(_Reason, _State) ->
+	ok.
+
+code_change(_OldVersion, State, _Extra) ->
+	{ok, State}.
+
+%% PRIVATE TOOLS
+
+monitor_if_pid(Key) when is_pid(Key) ->
+	erlang:monitor(process,Key);
+monitor_if_pid(_) ->
+	do_nothing.