egs/src/egs_app.erl

75 lines
2.3 KiB
Erlang

%% @author Loïc Hoguin <essen@dev-extend.eu>
%% @copyright 2010 Loïc Hoguin.
%% @doc Callbacks for the egs application.
%%
%% This file is part of EGS.
%%
%% EGS is free software: you can redistribute it and/or modify
%% it under the terms of the GNU General Public License as published by
%% the Free Software Foundation, either version 3 of the License, or
%% (at your option) any later version.
%%
%% EGS is distributed in the hope that it will be useful,
%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
%% GNU General Public License for more details.
%%
%% You should have received a copy of the GNU General Public License
%% along with EGS. If not, see <http://www.gnu.org/licenses/>.
-module(egs_app).
-behaviour(application).
-export([start/2, stop/1]).
-include("include/records.hrl").
%% @spec start(_Type, _StartArgs) -> ServerRet
%% @doc application start callback for egs.
start(_Type, _StartArgs) ->
case is_fresh_startup() of
true ->
db_init();
{exists, Tables} ->
ok = mnesia:wait_for_tables(Tables, 20000)
end,
egs_sup:start_link().
%% @spec stop(_State) -> ServerRet
%% @doc application stop callback for egs.
stop(_State) ->
ok.
%% @spec is_fresh_startup() -> true | false
%% @doc Returns true if mnesia has not been initialized with
%% the sherl schema.
%% Thanks to Dale Harvey for this function posted to
%% the erlang questions mailing list.
is_fresh_startup() ->
Node = node(),
case mnesia:system_info(tables) of
[schema] -> true;
Tables ->
case mnesia:table_info(schema, cookie) of
{_, Node} -> {exists, Tables};
_ -> true
end
end.
%% @todo doc
db_init() ->
Nodes = [node()],
case mnesia:system_info(is_running) of
yes ->
error_logger:info_report("stopping mnesia"),
mnesia:stop();
_ -> pass
end,
mnesia:create_schema(Nodes),
error_logger:info_report("mnesia schema created"),
error_logger:info_report("starting mnesia"),
mnesia:start(),
mnesia:create_table(counters, [{attributes, record_info(fields, counters)}]),
mnesia:create_table(psu_object, [{attributes, record_info(fields, psu_object)}]),
mnesia:create_table(egs_user_model, [{attributes, record_info(fields, egs_user_model)}]),
error_logger:info_report("mnesia tables created").