lib/erl/src/transport/tErlAcceptor.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 -module(tErlAcceptor).
   8
   9 -include("oop.hrl").
  10 -include("thrift.hrl").
  11 -include("tApplicationException.hrl").
  12 -include("transport/tTransportException.hrl").
  13 -include("protocol/tProtocolException.hrl").
  14 -include("transport/tServerSocket.hrl").
  15 -include("transport/tErlAcceptor.hrl").
  16
  17 -include_lib("kernel/include/inet.hrl").
  18
  19 -behavior(oop).
  20
  21 -export([attr/4, super/0, inspect/1]).
  22
  23 -export([new/3, accept/4]).
  24
  25 %%%
  26 %%% define attributes
  27 %%% 'super' is required unless ?MODULE is a base class
  28 %%%
  29
  30 ?DEFINE_ATTR(super);
  31 ?DEFINE_ATTR(serverPid);
  32 ?DEFINE_ATTR(transportFactory);
  33 ?DEFINE_ATTR(protocolFactory).
  34
  35 %%%
  36 %%% behavior callbacks
  37 %%%
  38
  39 %%% super() -> SuperModule = atom()
  40 %%%             |  none
  41
  42 super() ->
  43     tServerTransport.
  44
  45 %%% inspect(This) -> string()
  46
  47 inspect(This) ->
  48     ?FORMAT_ATTR(serverPid) ++ ", " ++
  49     ?FORMAT_ATTR(transportFactory) ++ ", " ++
  50     ?FORMAT_ATTR(protocolFactory).
  51
  52 %%%
  53 %%% class methods
  54 %%%
  55
  56 new(ServerPid, TF, PF) ->
  57     Super = (super()):new(),
  58     #?MODULE{super = Super,
  59              serverPid = ServerPid,
  60              transportFactory = TF,
  61              protocolFactory = PF
  62             }.
  63
  64 %%%
  65 %%% instance methods
  66 %%%
  67
  68 accept(This, ListenSocket, GP, Handler) ->
  69     ServerPid = oop:get(This, serverPid),
  70
  71     case catch gen_tcp:accept(ListenSocket) of
  72         {ok, Socket} ->
  73             ?C0(ServerPid, effectful_new_acceptor), % cast to create new acceptor
  74
  75             AddrString = render_addr(Socket),
  76             ?INFO("thrift connection accepted from ~s", [AddrString]),
  77
  78             Client = oop:start_new(tSocket, []),
  79             ?R1(Client, effectful_setHandle, Socket),
  80
  81             %% cpiro: OPAQUE!! Trans = Client
  82             TF      = oop:get(This, transportFactory),
  83             Trans   = ?F1(TF, getTransport, Client),
  84
  85             %% cpiro: OPAQUE!! Prot = start_new(tBinaryProtocol, [Trans])
  86             PF      = oop:get(This, protocolFactory),
  87             Prot    = ?F1(PF, getProtocol, Trans),
  88
  89             %% start_new(, ...)
  90             Processor = oop:start_new(tErlProcessor, [GP, Handler]),
  91
  92             try
  93                 receive_loop(This, Processor, Prot, Prot)
  94             catch
  95                 exit:{timeout, _} ->
  96                     ?INFO("thrift connection timed out from ~s", [AddrString]);
  97
  98                 %% cpiro: i think the extra entry on the stack is always from receive_loop
  99                 %% the below case shouldn't happen then?  if we move this catch inside
 100                 %% we'll probably need this case and not the next one
 101
 102                 %% exit:{thrift_exception, E} ->
 103                 %%     handle_exception(E, AddrString, no2);
 104
 105                 exit:{{thrift_exception, E}, Stack1} ->
 106                     handle_exception(E, AddrString, Stack1);
 107
 108                 Class:Else ->
 109                     ?ERROR("some other error ~p in tErlAcceptor: ~p", [Class, Else])
 110             end,
 111             exit(normal);
 112
 113         Else ->
 114             R = thrift_utils:sformat("accept() failed: ~p", [Else]),
 115             tException:throw(tTransportException, [R])
 116     end.
 117
 118
 119 handle_exception(E, AddrString, Stack1) ->
 120     case tException:read(E) of
 121         none -> % not a tException
 122             ?ERROR("not really a tException: ~p", [exit, E]);
 123
 124         {tProtocolException, ?tProtocolException_BAD_VERSION, _} ->
 125             ?INFO("thrift missing version from ~s", [AddrString]);
 126
 127         {tTransportException, ?tTransportException_NOT_OPEN, _} ->
 128             ?INFO("thrift connection closed from ~s", [AddrString]);
 129
 130         _ ->
 131             Where = "thrift tErlAcceptor caught a tException",
 132             ?ERROR("~s", [tException:inspect_with_backtrace(E, Where, Stack1)])
 133     end.
 134
 135 %% always calls itself ... only way to escape is through an exit
 136 receive_loop(This, Processor, Iprot, Oprot) ->
 137     case ?R2(Processor, process, Iprot, Oprot) of
 138         {error, Reason} ->
 139             case tException:read(Reason) of
 140                 none ->
 141                     ?ERROR("thrift handler returned something weird: {error, ~p}", [Reason]);
 142                 _ ->
 143                     Where = "thrift processor/handler caught a tException",
 144                     ?ERROR("~s", [tException:inspect_with_backtrace(Reason, Where)])
 145             end,
 146             receive_loop(This, Processor, Iprot, Oprot);
 147         Value ->
 148             ?INFO("thrift request: ~p", [Value]),
 149             receive_loop(This, Processor, Iprot, Oprot)
 150     end.
 151
 152 %% helper functions
 153
 154 %% @param Socket the socket in question
 155 %% TODO(cpiro): there probably needs to be a switch for DoLookup somewhere prominent and outside the lib,
 156 %% probably at the "application" level
 157 render_addr(Socket) ->
 158     DoLookup = true,
 159     {ok, {Peer, Port}} = inet:peername(Socket),
 160
 161     case Peer of
 162         _ when DoLookup ->
 163             case catch inet:gethostbyaddr(Peer) of
 164                 {ok, Hostent} ->
 165                     thrift_utils:sformat("~s:~p", [Hostent#hostent.h_name, Port]);
 166                 _ ->
 167                     "??"
 168             end;
 169
 170         {A,B,C,D} when not DoLookup ->
 171             thrift_utils:sformat("~p.~p.~p.~p:~p", [A,B,C,D,Port])
 172     end.