From 800965a957ccaa3832edd36c5b277b1d9ecc9d80 Mon Sep 17 00:00:00 2001
From: Christophe Romain <christophe.romain@process-one.net>
Date: Thu, 29 Jun 2017 15:24:18 +0200
Subject: [PATCH] Avoid useless calls on simples subscriptions (#1313)

---
 src/mod_pubsub.erl | 107 +++++++++++++++++++++++----------------------
 1 file changed, 54 insertions(+), 53 deletions(-)

diff --git a/src/mod_pubsub.erl b/src/mod_pubsub.erl
index 91d2f928a..1a620cb6b 100644
--- a/src/mod_pubsub.erl
+++ b/src/mod_pubsub.erl
@@ -3009,60 +3009,61 @@ c2s_handle_info(C2SState, _) ->
 
 subscribed_nodes_by_jid(NotifyType, SubsByDepth) ->
     NodesToDeliver = fun (Depth, Node, Subs, Acc) ->
-	    NodeName = case Node#pubsub_node.nodeid of
-		{_, N} -> N;
-		Other -> Other
-	    end,
-	    NodeOptions = Node#pubsub_node.options,
-	    lists:foldl(fun({LJID, SubID, SubOptions}, {JIDs, Recipients}) ->
-			case is_to_deliver(LJID, NotifyType, Depth, NodeOptions, SubOptions) of
-			    true ->
-				case state_can_deliver(LJID, SubOptions) of
-				    [] -> {JIDs, Recipients};
-				    JIDsToDeliver ->
-					lists:foldl(
-					    fun(JIDToDeliver, {JIDsAcc, RecipientsAcc}) ->
-						    case lists:member(JIDToDeliver, JIDs) of
-							%% check if the JIDs co-accumulator contains the Subscription Jid,
-							false ->
-							    %%  - if not,
-							    %%  - add the Jid to JIDs list co-accumulator ;
-							    %%  - create a tuple of the Jid, Nidx, and SubID (as list),
-							    %%    and add the tuple to the Recipients list co-accumulator
-							    {[JIDToDeliver | JIDsAcc],
-								[{JIDToDeliver, NodeName, [SubID]}
-								    | RecipientsAcc]};
-							true ->
-							    %% - if the JIDs co-accumulator contains the Jid
-							    %%   get the tuple containing the Jid from the Recipient list co-accumulator
-							    {_, {JIDToDeliver, NodeName1, SubIDs}} =
-								lists:keysearch(JIDToDeliver, 1, RecipientsAcc),
-							    %%   delete the tuple from the Recipients list
-							    % v1 : Recipients1 = lists:keydelete(LJID, 1, Recipients),
-							    % v2 : Recipients1 = lists:keyreplace(LJID, 1, Recipients, {LJID, Nidx1, [SubID | SubIDs]}),
-							    %%   add the SubID to the SubIDs list in the tuple,
-							    %%   and add the tuple back to the Recipients list co-accumulator
-							    % v1.1 : {JIDs, lists:append(Recipients1, [{LJID, Nidx1, lists:append(SubIDs, [SubID])}])}
-							    % v1.2 : {JIDs, [{LJID, Nidx1, [SubID | SubIDs]} | Recipients1]}
-							    % v2: {JIDs, Recipients1}
-							    {JIDsAcc,
-								lists:keyreplace(JIDToDeliver, 1,
-								    RecipientsAcc,
-								    {JIDToDeliver, NodeName1,
-									[SubID | SubIDs]})}
-						    end
-					    end, {JIDs, Recipients}, JIDsToDeliver)
-				end;
-			    false ->
-				{JIDs, Recipients}
-			end
-		end, Acc, Subs)
-    end,
+	NodeName = case Node#pubsub_node.nodeid of
+		       {_, N} -> N;
+		       Other -> Other
+		   end,
+	NodeOptions = Node#pubsub_node.options,
+	lists:foldl(fun({LJID, SubID, SubOptions}, {JIDs, Recipients}) ->
+	    case is_to_deliver(LJID, NotifyType, Depth, NodeOptions, SubOptions) of
+		true ->
+		    case state_can_deliver(LJID, SubOptions) of
+			[] -> {JIDs, Recipients};
+			[LJID] -> {JIDs, [{LJID, NodeName, [SubID]} | Recipients]};
+			JIDsToDeliver ->
+			    lists:foldl(
+				fun(JIDToDeliver, {JIDsAcc, RecipientsAcc}) ->
+					case lists:member(JIDToDeliver, JIDs) of
+					    %% check if the JIDs co-accumulator contains the Subscription Jid,
+					    false ->
+						%%  - if not,
+						%%  - add the Jid to JIDs list co-accumulator ;
+						%%  - create a tuple of the Jid, Nidx, and SubID (as list),
+						%%    and add the tuple to the Recipients list co-accumulator
+						{[JIDToDeliver | JIDsAcc],
+						    [{JIDToDeliver, NodeName, [SubID]}
+							| RecipientsAcc]};
+					    true ->
+						%% - if the JIDs co-accumulator contains the Jid
+						%%   get the tuple containing the Jid from the Recipient list co-accumulator
+						{_, {JIDToDeliver, NodeName1, SubIDs}} =
+						    lists:keysearch(JIDToDeliver, 1, RecipientsAcc),
+						%%   delete the tuple from the Recipients list
+						% v1 : Recipients1 = lists:keydelete(LJID, 1, Recipients),
+						% v2 : Recipients1 = lists:keyreplace(LJID, 1, Recipients, {LJID, Nidx1, [SubID | SubIDs]}),
+						%%   add the SubID to the SubIDs list in the tuple,
+						%%   and add the tuple back to the Recipients list co-accumulator
+						% v1.1 : {JIDs, lists:append(Recipients1, [{LJID, Nidx1, lists:append(SubIDs, [SubID])}])}
+						% v1.2 : {JIDs, [{LJID, Nidx1, [SubID | SubIDs]} | Recipients1]}
+						% v2: {JIDs, Recipients1}
+						{JIDsAcc,
+						    lists:keyreplace(JIDToDeliver, 1,
+							RecipientsAcc,
+							{JIDToDeliver, NodeName1,
+							    [SubID | SubIDs]})}
+					end
+				end, {JIDs, Recipients}, JIDsToDeliver)
+		    end;
+		false ->
+		    {JIDs, Recipients}
+	    end
+	end, Acc, Subs)
+	end,
     DepthsToDeliver = fun({Depth, SubsByNode}, Acc1) ->
-	    lists:foldl(fun({Node, Subs}, Acc2) ->
-			NodesToDeliver(Depth, Node, Subs, Acc2)
-		end, Acc1, SubsByNode)
-    end,
+	lists:foldl(fun({Node, Subs}, Acc2) ->
+			    NodesToDeliver(Depth, Node, Subs, Acc2)
+		    end, Acc1, SubsByNode)
+	end,
     {_, JIDSubs} = lists:foldl(DepthsToDeliver, {[], []}, SubsByDepth),
     JIDSubs.