%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2001-2016. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
%%----------------------------------------------------------------------
%% Purpose : Scanner for text encoded Megaco/H.248 messages
%%----------------------------------------------------------------------
-module(megaco_flex_scanner).
-export([is_enabled/0, is_reentrant_enabled/0, is_scanner_port/2]).
-export([start/0, start/1, stop/1, scan/2]).
-define(NUM_SCHED(), erlang:system_info(schedulers)).
-define(SCHED_ID(), erlang:system_info(scheduler_id)).
-define(SMP_SUPPORT_DEFAULT(), erlang:system_info(smp_support)).
is_enabled() ->
(true =:= ?ENABLE_MEGACO_FLEX_SCANNER).
is_reentrant_enabled() ->
(true =:= ?MEGACO_REENTRANT_FLEX_SCANNER).
is_scanner_port(Port, Port) when is_port(Port) ->
true;
is_scanner_port(Port, Ports) when is_tuple(Ports) ->
is_own_port(Port, Ports);
is_scanner_port(_, _) ->
false.
is_own_port(Port, Ports) ->
is_own_port(Port, size(Ports), Ports).
is_own_port(_Port, 0, _Ports) ->
false;
is_own_port(Port, N, Ports) when (N > 0) ->
case element(N, Ports) of
Port ->
true;
_ ->
is_own_port(Port, N-1, Ports)
end.
%%----------------------------------------------------------------------
%% Start the flex scanner
%%----------------------------------------------------------------------
start() ->
start(?SMP_SUPPORT_DEFAULT()).
start(SMP) when ((SMP =:= true) orelse (SMP =:= false)) ->
(catch do_start(is_reentrant_enabled() andalso SMP)).
do_start(SMP) ->
Path = lib_dir(),
erl_ddll:start(),
load_driver(Path),
PortOrPorts = open_drv_port(SMP),
{ok, PortOrPorts}.
lib_dir() ->
case code:priv_dir(megaco) of
{error, Reason} ->
throw({error, {priv_dir, Reason}});
P when is_list(P) ->
P ++ "/lib"
end.
load_driver(Path) ->
case erl_ddll:load_driver(Path, drv_name()) of
ok ->
ok;
{error, Reason} ->
case (catch erl_ddll:format_error(Reason)) of
FormatReason when is_list(FormatReason) ->
throw({error, {load_driver, FormatReason}});
_ ->
throw({error, {load_driver, Reason}})
end
end.
open_drv_port(true) ->
open_drv_ports(?NUM_SCHED(), []);
open_drv_port(_) ->
open_drv_port().
open_drv_ports(0, Acc) ->
list_to_tuple(Acc);
open_drv_ports(N, Acc) when is_integer(N) andalso (N > 0) ->
Port = open_drv_port(),
open_drv_ports(N-1, [Port | Acc]).
open_drv_port() ->
case (catch erlang:open_port({spawn, drv_name()}, [binary])) of
Port when is_port(Port) ->
Port;
{'EXIT', Reason} ->
erl_ddll:unload_driver(drv_name()),
throw({error, {open_port, Reason}})
end.
drv_name() ->
case erlang:system_info(threads) of
true ->
"megaco_flex_scanner_drv_mt";
false ->
"megaco_flex_scanner_drv"
end.
%%----------------------------------------------------------------------
%% Stop the flex scanner
%%----------------------------------------------------------------------
stop(Port) when is_port(Port) ->
erlang:port_close(Port),
erl_ddll:unload_driver(drv_name()),
stopped;
stop(Ports) when is_tuple(Ports) ->
stop(tuple_to_list(Ports));
stop(Ports) when is_list(Ports) ->
lists:foreach(fun(Port) -> erlang:port_close(Port) end, Ports),
erl_ddll:unload_driver(drv_name()),
stopped.
%%----------------------------------------------------------------------
%% Scan a message
%%----------------------------------------------------------------------
scan(Binary, Port) when is_port(Port) ->
do_scan(Binary, Port);
scan(Binary, Ports) when is_tuple(Ports) ->
%% p("scan -> entry with"
%% "~n Ports: ~p", [Ports]),
do_scan(Binary, select_port(Ports)).
do_scan(Binary, Port) ->
%% p("do_scan -> entry with"
%% "~n Port: ~p", [Port]),
case erlang:port_control(Port, $s, Binary) of
[] ->
receive
{tokens, Tokens, LatestLine} ->
%% p("do_scan -> OK with:"
%% "~n length(Tokens): ~p"
%% "~n LatestLine: ~p", [length(Tokens), LatestLine]),
Vsn = version(Tokens),
{ok, Tokens, Vsn, LatestLine}
after 5000 ->
%% p("do_scan -> ERROR", []),
{error, "Driver term send failure", 1}
end;
Reason ->
%% p("do_scan -> port control failed: "
%% "~n Reason: ~p", [Reason]),
{error, Reason, 1}
end.
select_port(Ports) ->
SchedId = ?SCHED_ID(),
%% lists:nth(SchedId, Ports).
element(SchedId, Ports).
version([]) ->
99; % Let the parser deal with this
version([{'SafeChars',_,"!/1"}|_]) ->
1;
version([{'SafeChars',_,"megaco/1"}|_]) ->
1;
version([{'SafeChars',_,"!/2"}|_]) ->
2;
version([{'SafeChars',_,"megaco/2"}|_]) ->
2;
version([{'SafeChars',_,"!/3"}|_]) ->
3;
version([{'SafeChars',_,"megaco/3"}|_]) ->
3;
version([{'SafeChars',_,[$!, $/ | Vstr]}|_]) ->
guess_version(Vstr);
version([{'SafeChars',_,[$m, $e, $g, $a, $c, $o, $/ | Vstr]}|_]) ->
guess_version(Vstr);
version([_|T]) ->
version(T).
guess_version([C]) when (48 =< C) and (C =< 57) ->
C-48;
guess_version(Str) when is_list(Str) ->
case (catch list_to_integer(Str)) of
I when is_integer(I) ->
I;
_ ->
99 % Let the parser deal with this
end;
guess_version(_) ->
99. % Let the parser deal with this
%% p(F, A) ->
%% io:format("~w [~p,~p] " ++ F ++ "~n", [?MODULE, self(), ?SCHED_ID() | A]).
