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Diffstat (limited to 'src/pubsub_index.erl')
| -rw-r--r-- | src/pubsub_index.erl | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/src/pubsub_index.erl b/src/pubsub_index.erl new file mode 100644 index 000000000..1ff5a1e45 --- /dev/null +++ b/src/pubsub_index.erl @@ -0,0 +1,67 @@ +%%% ==================================================================== +%%% ``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 2006-2013, ProcessOne +%%% All Rights Reserved.'' +%%% This software is copyright 2006-2013, ProcessOne. +%%% +%%% +%%% @copyright 2006-2013 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. |