PISTON-221: only record in ACDc once per call (#6736)

- prevent multiple overlapping recordings if caller re-enters a queue

Author: danielfinke

applications/acdc/src/acdc_agent_listener.erl

@@ -1188,10 +1188,10 @@ maybe_start_recording(Call, 'true', Url) ->
           ,{<<"url">>, Url}
           ]),
     lager:debug("starting recording listener for ~s", [Url]),
-    case acdc_recordings_sup:new(Call, RecordingJObj) of
-        {'ok', _P} ->
-            lager:debug("recording tracked in ~p", [_P]);
-        _E -> lager:debug("failed to start recording: ~p", [_E])
+    try acdc_recordings_map_srv:register(Call, RecordingJObj) of
+        _P -> lager:debug("recording tracked in ~p", [_P])
+    catch
+        'exit':_E -> lager:debug("failed to start recording: ~p", [_E])
     end.
 
 recording_format() ->

applications/acdc/src/acdc_recordings_map_srv.erl

@@ -0,0 +1,122 @@
+%%%-----------------------------------------------------------------------------
+%%% @copyright (C) 2016-2021, 2600Hz
+%%% @doc
+%%% @author Daniel Finke
+%%% @end
+%%%-----------------------------------------------------------------------------
+-module(acdc_recordings_map_srv).
+
+-behaviour(gen_server).
+
+%% API
+-export([start_link/0]).
+-export([register/2]).
+
+%% gen_server callbacks
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+         terminate/2, code_change/3]).
+
+-include("acdc.hrl").
+
+-define(SERVER, ?MODULE).
+
+-record(state, {table_id :: ets:tid()}).
+-type state() :: #state{}.
+
+%%%=============================================================================
+%%% API
+%%%=============================================================================
+
+%%------------------------------------------------------------------------------
+%% @doc Starts the server
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec start_link() -> kz_types:startlink_ret().
+start_link() ->
+    gen_server:start_link({'local', ?SERVER}, ?MODULE, [], []).
+
+-spec register(kapps_call:call(), kz_json:object()) -> pid().
+register(Call, RecordingJObj) ->
+    gen_server:call(?SERVER, {'register', Call, RecordingJObj}).
+
+%%%=============================================================================
+%%% gen_server callbacks
+%%%=============================================================================
+
+%%------------------------------------------------------------------------------
+%% @doc Initializes the server
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec init([]) -> {'ok', state()}.
+init([]) ->
+    process_flag('trap_exit', 'true'),
+    TabId = ets:new('map', []),
+    {'ok', #state{table_id=TabId}}.
+
+%%------------------------------------------------------------------------------
+%% @doc Handling call messages
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec handle_call(any(), kz_term:pid_ref(), state()) -> kz_types:handle_call_ret_state(state()).
+handle_call({'register', Call, RecordingJObj}, _From, #state{table_id=TabId}=State) ->
+    case ets:lookup(TabId, kapps_call:call_id(Call)) of
+        [] ->
+            {'ok', Pid} = acdc_recordings_sup:new(Call, RecordingJObj),
+            link(Pid),
+            ets:insert(TabId, {kapps_call:call_id(Call), Pid}),
+            Pid;
+        [{_, Pid}] -> Pid
+    end,
+    {'reply', Pid, State};
+handle_call(_Request, _From, State) ->
+    Reply = 'ok',
+    {'reply', Reply, State}.
+
+%%------------------------------------------------------------------------------
+%% @doc Handling cast messages
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec handle_cast(any(), state()) -> kz_types:handle_cast_ret_state(state()).
+handle_cast(_Msg, State) ->
+    {'noreply', State}.
+
+%%------------------------------------------------------------------------------
+%% @doc Handling all non call/cast messages
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec handle_info(any(), state()) -> kz_types:handle_info_ret_state(state()).
+handle_info({'EXIT', Pid, _Reason}, #state{table_id=TabId}=State) ->
+    ets:match_delete(TabId, {'$1', Pid}),
+    {'noreply', State};
+handle_info(_Info, State) ->
+    {'noreply', State}.
+
+%%------------------------------------------------------------------------------
+%% @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.
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec terminate(any(), state()) -> 'ok'.
+terminate(_Reason, _State) ->
+    'ok'.
+
+%%------------------------------------------------------------------------------
+%% @doc Convert process state when code is changed
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec code_change(any(), state(), any()) -> {'ok', state()}.
+code_change(_OldVsn, State, _Extra) ->
+    {'ok', State}.
+
+%%%=============================================================================
+%%% Internal functions
+%%%=============================================================================

applications/acdc/src/acdc_recordings_sup.erl

@@ -20,7 +20,7 @@
 
 -define(SERVER, ?MODULE).
 
--define(CHILDREN, [?WORKER_TYPE('kz_media_recording', 'transient')]).
+-define(CHILDREN, [?WORKER_TYPE('kzc_recording', 'transient')]).
 
 %%%=============================================================================
 %%% API functions

applications/acdc/src/acdc_sup.erl

@@ -28,6 +28,7 @@
                   ,?WORKER('acdc_agent_manager')
                   ,?WORKER('acdc_init')
                   ,?WORKER('acdc_listener')
+                  ,?WORKER('acdc_recordings_map_srv')
                   ]).
 
 %%==============================================================================