%% Copyright (c) 2013, Pedram Nimreezi %% %% Permission to use, copy, modify, and/or distribute this software for any %% purpose with or without fee is hereby granted, provided that the above %% copyright notice and this permission notice appear in all copies. %% %% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES %% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF %% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR %% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES %% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN %% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF %% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. -module(gr_param). -behaviour(gen_server). %% API -export([start_link/1, list/1, insert/2, lookup/2, lookup_element/2, info/1, info_size/1, transform/1]). %% gen_server callbacks -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]). -record(state, {table_id, waiting=[]}). %%%=================================================================== %%% API %%%=================================================================== list(Server) -> case (catch gen_server:call(Server, list)) of {'EXIT', _Reason} -> list(gr_manager:wait_for_pid(Server)); Else -> Else end. info_size(Server) -> case (catch gen_server:call(Server, info_size)) of {'EXIT', _Reason} -> info_size(gr_manager:wait_for_pid(Server)); Else -> Else end. insert(Server, Term) -> case (catch gen_server:call(Server, {insert, Term})) of {'EXIT', _Reason} -> insert(gr_manager:wait_for_pid(Server), Term); Else -> Else end. lookup(Server, Term) -> case (catch gen_server:call(Server, {lookup, Term})) of {'EXIT', _Reason} -> lookup(gr_manager:wait_for_pid(Server), Term); Else -> Else end. lookup_element(Server, Term) -> case (catch gen_server:call(Server, {lookup_element, Term})) of {'EXIT', _Reason} -> lookup_element(gr_manager:wait_for_pid(Server), Term); Else -> Else end. info(Server) -> case (catch gen_server:call(Server, info)) of {'EXIT', _Reason} -> info(gr_manager:wait_for_pid(Server)); Else -> Else end. %% @doc Transform Term -> Key to Key -> Term transform(Server) -> case (catch gen_server:call(Server, transform)) of {'EXIT', _Reason} -> transform(gr_manager:wait_for_pid(Server)); Else -> Else end. %%-------------------------------------------------------------------- %% @doc %% Starts the server %% %% @spec start_link(Name) -> {ok, Pid} | ignore | {error, Error} %% @end %%-------------------------------------------------------------------- start_link(Name) -> gen_server:start_link({local, Name}, ?MODULE, [], []). %%%=================================================================== %%% gen_server callbacks %%%=================================================================== %%-------------------------------------------------------------------- %% @private %% @doc %% Initializes the server %% %% @spec init(Args) -> {ok, State} | %% {ok, State, Timeout} | %% ignore | %% {stop, Reason} %% @end %%-------------------------------------------------------------------- init([]) -> {ok, #state{}}. %%-------------------------------------------------------------------- %% @private %% @doc %% Handling call messages %% %% @spec handle_call(Request, From, State) -> %% {reply, Reply, State} | %% {reply, Reply, State, Timeout} | %% {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, Reply, State} | %% {stop, Reason, State} %% @end %%-------------------------------------------------------------------- handle_call(Call, From, State) when is_atom(Call), Call =:= list; Call =:= info; Call =:= info_size; Call =:= transform -> TableId = State#state.table_id, Waiting = State#state.waiting, case TableId of undefined -> {noreply, State#state{waiting=[{Call, From}|Waiting]}}; _ when Call =:= list -> {reply, handle_list(TableId), State}; _ when Call =:= info -> {reply, handle_info(TableId), State}; _ when Call =:= info_size -> {reply, handle_info_size(TableId), State}; _ when Call =:= transform -> {reply, handle_transform(TableId), State} end; handle_call({Call, Term}, From, State) when is_atom(Call), Call =:= insert; Call =:= lookup; Call =:= lookup_element -> TableId = State#state.table_id, Waiting = State#state.waiting, case TableId of undefined -> {noreply, State#state{waiting=[{{Call, Term}, From}|Waiting]}}; _ when Call =:= insert -> {reply, handle_insert(TableId, Term), State}; _ when Call =:= lookup -> {reply, handle_lookup(TableId, Term), State}; _ when Call =:= lookup_element -> {reply, handle_lookup_element(TableId, Term), State} end; handle_call(_Request, _From, State) -> Reply = {error, unhandled_message}, {reply, Reply, State}. %%-------------------------------------------------------------------- %% @private %% @doc %% Handling cast messages %% %% @spec handle_cast(Msg, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% @end %%-------------------------------------------------------------------- handle_cast(_Msg, State) -> {noreply, State}. %%-------------------------------------------------------------------- %% @private %% @doc %% Handling all non call/cast messages %% %% @spec handle_info(Info, State) -> {noreply, State} | %% {noreply, State, Timeout} | %% {stop, Reason, State} %% @end %%-------------------------------------------------------------------- handle_info({'ETS-TRANSFER', TableId, _Pid, _Data}, State) -> _ = [ gen_server:reply(From, perform_call(TableId, Call)) || {Call, From} <- State#state.waiting ], {noreply, State#state{table_id=TableId, waiting=[]}}; handle_info(_Info, State) -> {noreply, State}. %%-------------------------------------------------------------------- %% @private %% @doc %% This function is called by a gen_server when it is about to %% terminate. It should be the opposite of Module:init/1 and do any %% necessary cleaning up. When it returns, the gen_server terminates %% with Reason. The return value is ignored. %% %% @spec terminate(Reason, State) -> void() %% @end %%-------------------------------------------------------------------- terminate(_Reason, _State) -> ok. %%-------------------------------------------------------------------- %% @private %% @doc %% Convert process state when code is changed %% %% @spec code_change(OldVsn, State, Extra) -> {ok, NewState} %% @end %%-------------------------------------------------------------------- code_change(_OldVsn, State, _Extra) -> {ok, State}. %%%=================================================================== %%% Internal functions %%%=================================================================== perform_call(TableId, Call) -> case Call of list -> handle_list(TableId); info -> handle_info(TableId); info_size -> handle_info_size(TableId); transform -> handle_transform(TableId); {insert, Term} -> handle_insert(TableId, Term); {lookup, Term} -> handle_lookup(TableId, Term); {lookup_element, Term} -> handle_lookup_element(TableId, Term) end. handle_list(TableId) -> ets:tab2list(TableId). handle_info(TableId) -> ets:info(TableId). handle_info_size(TableId) -> ets:info(TableId, size). handle_transform(TableId) -> ParamsList = [{K, V} || {V, K} <- ets:tab2list(TableId)], ets:delete_all_objects(TableId), ets:insert(TableId, ParamsList). handle_insert(TableId, Term) -> ets:insert(TableId, Term). handle_lookup(TableId, Term) -> ets:lookup(TableId, Term). handle_lookup_element(TableId, Term) -> ets:lookup_element(TableId, Term, 2).