ceph/src/jaegertracing/thrift/lib/erl/src/thrift_transport_state_test.erl

   1 %%
   2 %% Licensed to the Apache Software Foundation (ASF) under one
   3 %% or more contributor license agreements. See the NOTICE file
   4 %% distributed with this work for additional information
   5 %% regarding copyright ownership. The ASF licenses this file
   6 %% to you under the Apache License, Version 2.0 (the
   7 %% "License"); you may not use this file except in compliance
   8 %% with the License. You may obtain a copy of the License at
   9 %%
  10 %%   http://www.apache.org/licenses/LICENSE-2.0
  11 %%
  12 %% Unless required by applicable law or agreed to in writing,
  13 %% software distributed under the License is distributed on an
  14 %% "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  15 %% KIND, either express or implied. See the License for the
  16 %% specific language governing permissions and limitations
  17 %% under the License.
  18 %%
  19
  20 -module(thrift_transport_state_test).
  21
  22 -behaviour(gen_server).
  23 -behaviour(thrift_transport).
  24
  25 %% API
  26 -export([new/1]).
  27
  28 %% gen_server callbacks
  29 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
  30          terminate/2, code_change/3]).
  31
  32 %% thrift_transport callbacks
  33 -export([write/2, read/2, flush/1, close/1]).
  34
  35 -record(trans, {wrapped, % #thrift_transport{}
  36                 version :: integer(),
  37                 counter :: pid()
  38                }).
  39 -type state() :: #trans{}.
  40 -include("thrift_transport_behaviour.hrl").
  41
  42 -record(state, {cversion :: integer()}).
  43
  44
  45 new(WrappedTransport) ->
  46     case gen_server:start_link(?MODULE, [], []) of
  47         {ok, Pid} ->
  48             Trans = #trans{wrapped = WrappedTransport,
  49                            version = 0,
  50                            counter = Pid},
  51             thrift_transport:new(?MODULE, Trans);
  52         Else ->
  53             Else
  54     end.
  55
  56 %%====================================================================
  57 %% thrift_transport callbacks
  58 %%====================================================================
  59
  60 write(Transport0 = #trans{wrapped = Wrapped0}, Data) ->
  61     Transport1 = check_version(Transport0),
  62     {Wrapped1, Result} = thrift_transport:write(Wrapped0, Data),
  63     Transport2 = Transport1#trans{wrapped = Wrapped1},
  64     {Transport2, Result}.
  65
  66 flush(Transport0 = #trans{wrapped = Wrapped0}) ->
  67     Transport1 = check_version(Transport0),
  68     {Wrapped1, Result} = thrift_transport:flush(Wrapped0),
  69     Transport2 = Transport1#trans{wrapped = Wrapped1},
  70     {Transport2, Result}.
  71
  72 close(Transport0 = #trans{wrapped = Wrapped0}) ->
  73     Transport1 = check_version(Transport0),
  74     shutdown_counter(Transport1),
  75     {Wrapped1, Result} = thrift_transport:close(Wrapped0),
  76     Transport2 = Transport1#trans{wrapped = Wrapped1},
  77     {Transport2, Result}.
  78
  79 read(Transport0 = #trans{wrapped = Wrapped0}, Len) ->
  80     Transport1 = check_version(Transport0),
  81     {Wrapped1, Result} = thrift_transport:read(Wrapped0, Len),
  82     Transport2 = Transport1#trans{wrapped = Wrapped1},
  83     {Transport2, Result}.
  84
  85
  86 %%====================================================================
  87 %% gen_server callbacks
  88 %%====================================================================
  89
  90 init([]) ->
  91     {ok, #state{cversion = 0}}.
  92
  93 handle_call(check_version, _From, State = #state{cversion = Version}) ->
  94     {reply, Version, State#state{cversion = Version+1}}.
  95
  96 handle_cast(shutdown, State) ->
  97     {stop, normal, State}.
  98
  99 handle_info(_Info, State) -> {noreply, State}.
 100 code_change(_OldVsn, State, _Extra) -> {ok, State}.
 101 terminate(_Reason, _State) -> ok.
 102
 103 %%--------------------------------------------------------------------
 104 %% Internal functions
 105 %%--------------------------------------------------------------------
 106
 107 check_version(Transport = #trans{version = Version, counter = Counter}) ->
 108     case gen_server:call(Counter, check_version) of
 109         Version ->
 110             Transport#trans{version = Version+1};
 111         _Else ->
 112             % State wasn't propagated properly.  Die.
 113             erlang:error(state_not_propagated)
 114     end.
 115
 116 shutdown_counter(#trans{counter = Counter}) ->
 117     gen_server:cast(Counter, shutdown).