89 lines
2.4 KiB
Erlang
89 lines
2.4 KiB
Erlang
%%% ====================================================================
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%%% ``The contents of this file are subject to the Erlang Public License,
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%%% Version 1.1, (the "License"); you may not use this file except in
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%%% compliance with the License. You should have received a copy of the
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%%% Erlang Public License along with this software. If not, it can be
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%%% retrieved via the world wide web at http://www.erlang.org/.
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%%%
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%%% Software distributed under the License is distributed on an "AS IS"
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%%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
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%%% the License for the specific language governing rights and limitations
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%%% under the License.
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%%%
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%%% The Initial Developer of the Original Code is ProcessOne.
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%%% Portions created by ProcessOne are Copyright 2006-2011, ProcessOne
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%%% All Rights Reserved.''
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%%% This software is copyright 2006-2011, ProcessOne.
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%%%
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%%%
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%%% @copyright 2006-2011 ProcessOne
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%%% @author Christophe Romain <christophe.romain@process-one.net>
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%%% [http://www.process-one.net/]
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%%% @version {@vsn}, {@date} {@time}
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%%% @end
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%%% ====================================================================
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%% important note:
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%% new/1 and free/2 MUST be called inside a transaction bloc
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-module(pubsub_index).
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-author('christophe.romain@process-one.net').
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-include("pubsub.hrl").
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-export([
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init/3,
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new/1,
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free/2
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]).
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-spec(init/3 ::
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(
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Host :: string(),
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ServerHost :: string(),
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Opts :: [{Key::atom(), Value::term()}])
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-> 'ok'
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).
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init(_Host, _ServerHost, _Opts) ->
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mnesia:create_table(pubsub_index,
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[{disc_copies, [node()]},
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{attributes, record_info(fields, pubsub_index)}]).
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-spec(new/1 ::
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(
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Index::atom())
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-> Idx::integer()
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).
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new(Index) ->
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case mnesia:read({pubsub_index, Index}) of
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[#pubsub_index{free = [], last = Last} = PubsubIndex] ->
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Idx = Last + 1,
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mnesia:write(PubsubIndex#pubsub_index{last = Idx}),
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Idx;
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[#pubsub_index{free = [Idx|Free]} = PubsubIndex] ->
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mnesia:write(PubsubIndex#pubsub_index{free = Free}),
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Idx;
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_ ->
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mnesia:write(#pubsub_index{index = Index, last = 1, free = []}),
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1
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end.
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-spec(free/2 ::
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(
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Index :: atom(),
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Idx :: integer())
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-> 'ok'
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).
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free(Index, Idx) ->
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case mnesia:read({pubsub_index, Index}) of
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[#pubsub_index{free = Free} = PubsubIndex] ->
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mnesia:write(PubsubIndex#pubsub_index{free = [Idx|Free]});
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_ -> ok
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end.
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