PubSub/PEP API change for major optimization

SVN Revision: 2048

1 files changed, 65 insertions, 0 deletions

diff --git a/src/mod_pubsub/pubsub_index.erl b/src/mod_pubsub/pubsub_index.erl
new file mode 100644
index 000000000..2ba5d4b20
--- /dev/null
+++ b/src/mod_pubsub/pubsub_index.erl
@@ -0,0 +1,65 @@
+%%% ====================================================================
+%%% ``The contents of this file are subject to the Erlang Public License,
+%%% Version 1.1, (the "License"); you may not use this file except in
+%%% compliance with the License. You should have received a copy of the
+%%% Erlang Public License along with this software. If not, it can be
+%%% retrieved via the world wide web at http://www.erlang.org/.
+%%% 
+%%% Software distributed under the License is distributed on an "AS IS"
+%%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%%% the License for the specific language governing rights and limitations
+%%% under the License.
+%%% 
+%%% The Initial Developer of the Original Code is ProcessOne.
+%%% Portions created by ProcessOne are Copyright 2006-2009, ProcessOne
+%%% All Rights Reserved.''
+%%% This software is copyright 2006-2009, ProcessOne.
+%%%
+%%%
+%%% @copyright 2006-2009 ProcessOne
+%%% @author Christophe Romain <christophe.romain@process-one.net>
+%%%   [http://www.process-one.net/]
+%%% @version {@vsn}, {@date} {@time}
+%%% @end
+%%% ====================================================================
+
+%% important note:
+%% new/1 and free/2 MUST be called inside a transaction bloc
+
+-module(pubsub_index).
+-author('christophe.romain@process-one.net').
+
+-include("pubsub.hrl").
+
+-export([init/3, new/1, free/2]).
+
+init(_Host, _ServerHost, _Opts) ->
+    mnesia:create_table(pubsub_index,
+			[{disc_copies, [node()]},
+			 {attributes, record_info(fields, pubsub_index)}]).
+
+new(Index) ->
+    case mnesia:read({pubsub_index, Index}) of
+    [I] ->
+	case I#pubsub_index.free of
+	[] ->
+	    Id = I#pubsub_index.last + 1,
+	    mnesia:write(I#pubsub_index{last = Id}),
+	    Id;
+	[Id|Free] ->
+	    mnesia:write(I#pubsub_index{free = Free}),
+	    Id
+	end;
+    _ ->
+	mnesia:write(#pubsub_index{index = Index, last = 1, free = []}),
+	1
+    end.
+
+free(Index, Id) ->
+    case mnesia:read({pubsub_index, Index}) of
+    [I] ->
+	Free = I#pubsub_index.free,
+	mnesia:write(I#pubsub_index{free = [Id|Free]});
+    _ ->
+	ok
+    end.