lib/erl/src/thrift_oop_server.erl

   1 %%% Copyright (c) 2007- Facebook
   2 %%% Distributed under the Thrift Software License
   3 %%%
   4 %%% See accompanying file LICENSE or visit the Thrift site at:
   5 %%% http://developers.facebook.com/thrift/
   6
   7 %%%-------------------------------------------------------------------
   8 %%% @doc
   9 %%% @end
  10 %%%-------------------------------------------------------------------
  11 -module(thrift_oop_server).
  12
  13 -behaviour(gen_server).
  14 %%--------------------------------------------------------------------
  15 %% Include files
  16 %%--------------------------------------------------------------------
  17 -include("oop.hrl").
  18
  19 -include("thrift.hrl").
  20
  21 %%--------------------------------------------------------------------
  22 %% External exports
  23 %%--------------------------------------------------------------------
  24 -export([
  25          start_link/0,
  26          stop/0
  27          ]).
  28
  29 %%--------------------------------------------------------------------
  30 %% gen_server callbacks
  31 %%--------------------------------------------------------------------
  32 -export([init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3]).
  33
  34 %%--------------------------------------------------------------------
  35 %% record definitions
  36 %%--------------------------------------------------------------------
  37
  38 %%--------------------------------------------------------------------
  39 %% macro definitions
  40 %%--------------------------------------------------------------------
  41 -define(SERVER, ?MODULE).
  42
  43 %%====================================================================
  44 %% External functions
  45 %%====================================================================
  46 %%--------------------------------------------------------------------
  47 %% @doc Starts the server.
  48 %% @spec start_link() -> {ok, pid()} | {error, Reason}
  49 %% @end
  50 %%--------------------------------------------------------------------
  51 start_link() ->
  52     gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
  53
  54 %%--------------------------------------------------------------------
  55 %% @doc Stops the server.
  56 %% @spec stop() -> ok
  57 %% @end
  58 %%--------------------------------------------------------------------
  59 stop() ->
  60     gen_server:cast(?SERVER, stop).
  61
  62 %%====================================================================
  63 %% Server functions
  64 %%====================================================================
  65
  66 %%--------------------------------------------------------------------
  67 %% Function: init/1
  68 %% Description: Initiates the server
  69 %% Returns: {ok, State}          |
  70 %%          {ok, State, Timeout} |
  71 %%          ignore               |
  72 %%          {stop, Reason}
  73 %%--------------------------------------------------------------------
  74
  75 init({Class, Args}) ->
  76     process_flag(trap_exit, true),
  77     try
  78         State = apply(Class, new, Args),
  79         ?INFO("thrift ~p:new(~s) = ~s", [Class, thrift_utils:unbrack(Args), oop:inspect(State)]),
  80         {ok, State}
  81     catch
  82         E -> {stop, {new_failed, E}}
  83     end;
  84
  85 init(_) ->
  86     {stop, invalid_params}.
  87
  88 %%--------------------------------------------------------------------
  89 %% Function: handle_call/3
  90 %% Description: Handling call messages
  91 %% Returns: {reply, Reply, State}          |
  92 %%          {reply, Reply, State, Timeout} |
  93 %%          {noreply, State}               |
  94 %%          {noreply, State, Timeout}      |
  95 %%          {stop, Reason, Reply, State}   | (terminate/2 is called)
  96 %%          {stop, Reason, State}            (terminate/2 is called)
  97 %%--------------------------------------------------------------------
  98
  99 handle_call(Request, From, State) ->
 100     handle_either(call, Request, From, State).
 101
 102 %%--------------------------------------------------------------------
 103 %% Function: handle_cast/2
 104 %% Description: Handling cast messages
 105 %% Returns: {noreply, State}          |
 106 %%          {noreply, State, Timeout} |
 107 %%          {stop, Reason, State}            (terminate/2 is called)
 108 %%--------------------------------------------------------------------
 109
 110 handle_cast(stop, State) ->
 111     {stop, normal, State};
 112
 113 handle_cast({Method, Args}, State) ->
 114     handle_either(cast, {Method, Args}, undefined, State).
 115
 116 -define(REPLY(Value, State),
 117         case Type of
 118             call -> {reply, Value, State};
 119             cast -> {noreply, State}
 120         end
 121 ).
 122
 123 handle_either(Type, Request, From, State) ->
 124     %% error_logger:info_msg("~p: ~p", [?SERVER, oop:inspect(State)]),
 125     %% error_logger:info_msg("handle_call(Request=~p, From=~p, State)", [Request, From]),
 126
 127     case Request of
 128         {get, [Field]} ->
 129             Value = oop:get(State, Field),
 130             ?REPLY(Value, State);
 131
 132         {set, [Field, Value]} ->
 133             State1 = oop:set(State, Field, Value),
 134             ?REPLY(Value, State1);
 135
 136         {class, []} ->
 137             ?REPLY(?CLASS(State), State);
 138
 139         {Method, Args} ->
 140             handle_method(Type, State, Method, Args);
 141
 142         _ ->
 143             error_logger:format("no match for Request = ~p", [Request]),
 144             %% {stop, server_error, State}
 145             {reply, server_error, State}
 146     end.
 147
 148 handle_method(Type, State, Method, Args) ->
 149     %% is an effectful call?
 150     Is_effectful = lists:prefix("effectful_", atom_to_list(Method)),
 151     Call         = oop:call(State, Method, Args),
 152
 153     %% TODO(cpiro): maybe add error handling here? = catch oop:call?
 154
 155     case {Is_effectful, Call} of
 156         {true, {Retval, State1}} ->
 157             ?REPLY(Retval, State1);
 158
 159         {true, _MalformedReturn} ->
 160             %% TODO(cpiro): bad match -- remove when we're done converting
 161             error_logger:format("oop:call(effectful_*,..,..) malformed return value ~p",
 162                                 [_MalformedReturn]),
 163             %% {stop, server_error, State}
 164             {noreply, State};
 165
 166         {false, Retval} ->
 167             ?REPLY(Retval, State)
 168     end.
 169
 170 %%--------------------------------------------------------------------
 171 %% Function: handle_info/2
 172 %% Description: Handling all non call/cast messages
 173 %% Returns: {noreply, State}          |
 174 %%          {noreply, State, Timeout} |
 175 %%          {stop, Reason, State}            (terminate/2 is called)
 176 %%--------------------------------------------------------------------
 177 handle_info({'EXIT', Pid, Except} = All, State) ->
 178     Result = try
 179         oop:call(State, catches, [Pid, Except])
 180     catch
 181         exit:{missing_method, _} ->
 182             unhandled
 183     end,
 184
 185     case Result of
 186         unhandled ->
 187             error_logger:format("unhandled exit ~p", [All]),
 188             {stop, All, State};
 189         _WasHandled ->
 190             {noreply, State}
 191     end;
 192
 193 handle_info(Info, State) ->
 194     error_logger:info_msg("~p", [Info]),
 195     {noreply, State}.
 196
 197 %%--------------------------------------------------------------------
 198 %% Function: terminate/2
 199 %% Description: Shutdown the server
 200 %% Returns: any (ignored by gen_server)
 201 %%--------------------------------------------------------------------
 202 terminate(Reason, State) ->
 203     %%error_logger:format("~p terminated!: ~p", [self(), Reason]),
 204     ok.
 205
 206 %%--------------------------------------------------------------------
 207 %% Func: code_change/3
 208 %% Purpose: Convert process state when code is changed
 209 %% Returns: {ok, NewState}
 210  %%--------------------------------------------------------------------
 211 code_change(OldVsn, State, Extra) ->
 212     {ok, State}.
 213
 214 %%====================================================================
 215 %%% Internal functions
 216 %%====================================================================