mod_client_state: Add function specifications

Add function specifications and apply cosmetic changes to
mod_client_state.

src/mod_client_state.erl

@@ -30,9 +30,12 @@
 
 -behavior(gen_mod).
 
--export([start/2, stop/1, add_stream_feature/2,
+%% gen_mod callbacks.
-	 filter_presence/3, filter_chat_states/3, filter_pep/3, filter_other/3,
+-export([start/2, stop/1, mod_opt_type/1]).
-	 flush_queue/2, mod_opt_type/1]).
+
+%% ejabberd_hooks callbacks.
+-export([filter_presence/3, filter_chat_states/3, filter_pep/3, filter_other/3,
+	 flush_queue/2, add_stream_feature/2]).
 
 -include("ejabberd.hrl").
 -include("logger.hrl").
@@ -40,6 +43,17 @@
 
 -define(CSI_QUEUE_MAX, 100).
 
+-type csi_type() :: presence | chatstate | {pep, binary(), binary()}.
+-type csi_key() :: {ljid(), csi_type()}.
+-type csi_stanza() :: {csi_key(), erlang:timestamp(), xmlel()}.
+-type csi_queue() :: [csi_stanza()].
+
+%%--------------------------------------------------------------------
+%% gen_mod callbacks.
+%%--------------------------------------------------------------------
+
+-spec start(binary(), gen_mod:opts()) -> ok.
+
 start(Host, Opts) ->
     QueuePresence =
 	gen_mod:get_opt(queue_presence, Opts,
@@ -78,6 +92,8 @@ start(Host, Opts) ->
        true -> ok
     end.
 
+-spec stop(binary()) -> ok.
+
 stop(Host) ->
     QueuePresence =
 	gen_mod:get_module_opt(Host, ?MODULE, queue_presence,
@@ -116,11 +132,22 @@ stop(Host) ->
        true -> ok
     end.
 
-add_stream_feature(Features, _Host) ->
+-spec mod_opt_type(atom()) -> fun((term()) -> term()) | [atom()].
-    Feature = #xmlel{name = <<"csi">>,
+
-		     attrs = [{<<"xmlns">>, ?NS_CLIENT_STATE}],
+mod_opt_type(queue_presence) ->
-		     children = []},
+    fun(B) when is_boolean(B) -> B end;
-    [Feature | Features].
+mod_opt_type(queue_chat_states) ->
+    fun(B) when is_boolean(B) -> B end;
+mod_opt_type(queue_pep) ->
+    fun(B) when is_boolean(B) -> B end;
+mod_opt_type(_) -> [queue_presence, queue_chat_states, queue_pep].
+
+%%--------------------------------------------------------------------
+%% ejabberd_hooks callbacks.
+%%--------------------------------------------------------------------
+
+-spec filter_presence({term(), [xmlel()]}, binary(), xmlel())
+      -> {term(), [xmlel()]} | {stop, {term(), [xmlel()]}}.
 
 filter_presence({C2SState, _OutStanzas} = Acc, Host,
 		#xmlel{name = <<"presence">>, attrs = Attrs} = Stanza) ->
@@ -133,6 +160,9 @@ filter_presence({C2SState, _OutStanzas} = Acc, Host,
     end;
 filter_presence(Acc, _Host, _Stanza) -> Acc.
 
+-spec filter_chat_states({term(), [xmlel()]}, binary(), xmlel())
+      -> {term(), [xmlel()]} | {stop, {term(), [xmlel()]}}.
+
 filter_chat_states({C2SState, _OutStanzas} = Acc, Host,
 		   #xmlel{name = <<"message">>} = Stanza) ->
     case jlib:is_standalone_chat_state(Stanza) of
@@ -144,6 +174,9 @@ filter_chat_states({C2SState, _OutStanzas} = Acc, Host,
     end;
 filter_chat_states(Acc, _Host, _Stanza) -> Acc.
 
+-spec filter_pep({term(), [xmlel()]}, binary(), xmlel())
+      -> {term(), [xmlel()]} | {stop, {term(), [xmlel()]}}.
+
 filter_pep({C2SState, _OutStanzas} = Acc, Host,
 	   #xmlel{name = <<"message">>} = Stanza) ->
     case find_pep(Stanza) of
@@ -155,51 +188,35 @@ filter_pep({C2SState, _OutStanzas} = Acc, Host,
     end;
 filter_pep(Acc, _Host, _Stanza) -> Acc.
 
+-spec filter_other({term(), [xmlel()]}, binary(), xmlel())
+      -> {stop, {term(), [xmlel()]}}.
+
 filter_other({C2SState, _OutStanzas}, Host, Stanza) ->
     ?DEBUG("Won't add stanza to CSI queue", []),
     queue_take(Stanza, Host, C2SState).
 
+-spec flush_queue({term(), [xmlel()]}, binary()) -> {term(), [xmlel()]}.
+
 flush_queue({C2SState, _OutStanzas}, Host) ->
     ?DEBUG("Going to flush CSI queue", []),
     Queue = get_queue(C2SState),
     NewState = set_queue([], C2SState),
-    {stop, {NewState, get_stanzas(Queue, Host)}}.
+    {NewState, get_stanzas(Queue, Host)}.
 
-find_pep(#xmlel{name = <<"message">>} = Stanza) ->
+-spec add_stream_feature([xmlel()], binary) -> [xmlel()].
-    From = fxml:get_tag_attr_s(<<"from">>, Stanza),
-    case jid:from_string(From) of
-      #jid{luser = <<>>} -> % It's not PEP.
-	  false;
-      _ ->
-	  case fxml:get_subtag_with_xmlns(Stanza, <<"event">>,
-					  ?NS_PUBSUB_EVENT) of
-	    #xmlel{children = Els} ->
-		get_pep_node_and_xmlns(fxml:remove_cdata(Els));
-	    false ->
-		false
-	  end
-    end.
 
-get_pep_node_and_xmlns([#xmlel{name = <<"items">>, attrs = ItemsAttrs,
+add_stream_feature(Features, _Host) ->
-			       children = Item}]) ->
+    Feature = #xmlel{name = <<"csi">>,
-    case {fxml:get_attr(<<"node">>, ItemsAttrs), fxml:remove_cdata(Item)} of
+		     attrs = [{<<"xmlns">>, ?NS_CLIENT_STATE}],
-      {{value, Node}, [#xmlel{name = <<"item">>, children = Payload}]} ->
+		     children = []},
-	  case fxml:remove_cdata(Payload) of
+    [Feature | Features].
-	    [#xmlel{attrs = PayloadAttrs}] ->
+
-		case fxml:get_attr(<<"xmlns">>, PayloadAttrs) of
+%%--------------------------------------------------------------------
-		  {value, XMLNS} ->
+%% Internal functions.
-		      {value, {Node, XMLNS}};
+%%--------------------------------------------------------------------
-		  false ->
+
-		      false
+-spec queue_add(csi_type(), xmlel(), binary(), term())
-		end;
+      -> {stop, {term(), [xmlel()]}}.
-	    _ ->
-		false
-	  end;
-      _ ->
-	  false
-    end;
-get_pep_node_and_xmlns(_) ->
-    false.
 
 queue_add(Type, Stanza, Host, C2SState) ->
     case get_queue(C2SState) of
@@ -217,6 +234,8 @@ queue_add(Type, Stanza, Host, C2SState) ->
 	  {stop, {NewState, []}}
     end.
 
+-spec queue_take(xmlel(), binary(), term()) -> {stop, {term(), [xmlel()]}}.
+
 queue_take(Stanza, Host, C2SState) ->
     From = fxml:get_tag_attr_s(<<"from">>, Stanza),
     {LUser, LServer, _LResource} = jid:tolower(jid:from_string(From)),
@@ -227,9 +246,13 @@ queue_take(Stanza, Host, C2SState) ->
     NewState = set_queue(Rest, C2SState),
     {stop, {NewState, get_stanzas(Selected, Host) ++ [Stanza]}}.
 
+-spec set_queue(csi_queue(), term()) -> term().
+
 set_queue(Queue, C2SState) ->
     ejabberd_c2s:set_aux_field(csi_queue, Queue, C2SState).
 
+-spec get_queue(term()) -> csi_queue().
+
 get_queue(C2SState) ->
     case ejabberd_c2s:get_aux_field(csi_queue, C2SState) of
       {ok, Queue} ->
@@ -238,16 +261,50 @@ get_queue(C2SState) ->
 	      []
     end.
 
+-spec get_stanzas(csi_queue(), binary()) -> [xmlel()].
+
 get_stanzas(Queue, Host) ->
     lists:map(fun({_Key, Time, Stanza}) ->
 		      jlib:add_delay_info(Stanza, Host, Time,
 					  <<"Client Inactive">>)
 	      end, Queue).
 
-mod_opt_type(queue_presence) ->
+-spec find_pep(xmlel()) -> {pep, binary(), binary()} | false.
-    fun(B) when is_boolean(B) -> B end;
+
-mod_opt_type(queue_chat_states) ->
+find_pep(#xmlel{name = <<"message">>} = Stanza) ->
-    fun(B) when is_boolean(B) -> B end;
+    From = fxml:get_tag_attr_s(<<"from">>, Stanza),
-mod_opt_type(queue_pep) ->
+    case jid:from_string(From) of
-    fun(B) when is_boolean(B) -> B end;
+      #jid{luser = <<>>} -> % It's not PEP.
-mod_opt_type(_) -> [queue_presence, queue_chat_states, queue_pep].
+	  false;
+      _ ->
+	  case fxml:get_subtag_with_xmlns(Stanza, <<"event">>,
+					  ?NS_PUBSUB_EVENT) of
+	    #xmlel{children = Els} ->
+		get_pep_node_and_xmlns(fxml:remove_cdata(Els));
+	    false ->
+		false
+	  end
+    end.
+
+-spec get_pep_node_and_xmlns([xmlel()]) -> {pep, binary(), binary()} | false.
+
+get_pep_node_and_xmlns([#xmlel{name = <<"items">>, attrs = ItemsAttrs,
+			       children = Item}]) ->
+    case {fxml:get_attr(<<"node">>, ItemsAttrs), fxml:remove_cdata(Item)} of
+      {{value, Node}, [#xmlel{name = <<"item">>, children = Payload}]} ->
+	  case fxml:remove_cdata(Payload) of
+	    [#xmlel{attrs = PayloadAttrs}] ->
+		case fxml:get_attr(<<"xmlns">>, PayloadAttrs) of
+		  {value, XMLNS} ->
+		      {value, {pep, Node, XMLNS}};
+		  false ->
+		      false
+		end;
+	    _ ->
+		false
+	  end;
+      _ ->
+	  false
+    end;
+get_pep_node_and_xmlns(_) ->
+    false.