emqx/src/emqx_mountpoint.erl

65 lines
2.1 KiB
Erlang

%% Copyright (c) 2013-2019 EMQ Technologies Co., Ltd. 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.
-module(emqx_mountpoint).
-include("emqx.hrl").
-include("logger.hrl").
-export([ mount/2
, unmount/2
]).
-export([replvar/2]).
-type(mountpoint() :: binary()).
-export_type([mountpoint/0]).
%%------------------------------------------------------------------------------
%% APIs
%%------------------------------------------------------------------------------
mount(undefined, Any) ->
Any;
mount(MountPoint, Msg = #message{topic = Topic}) ->
Msg#message{topic = <<MountPoint/binary, Topic/binary>>};
mount(MountPoint, TopicFilters) when is_list(TopicFilters) ->
[{<<MountPoint/binary, Topic/binary>>, SubOpts} || {Topic, SubOpts} <- TopicFilters].
unmount(undefined, Msg) ->
Msg;
unmount(MountPoint, Msg = #message{topic = Topic}) ->
try split_binary(Topic, byte_size(MountPoint)) of
{MountPoint, Topic1} -> Msg#message{topic = Topic1}
catch
_Error:Reason ->
?LOG(error, "[Mountpoint] Unmount error : ~p", [Reason]),
Msg
end.
replvar(undefined, _Vars) ->
undefined;
replvar(MountPoint, #{client_id := ClientId, username := Username}) ->
lists:foldl(fun feed_var/2, MountPoint, [{<<"%c">>, ClientId}, {<<"%u">>, Username}]).
feed_var({<<"%c">>, ClientId}, MountPoint) ->
emqx_topic:feed_var(<<"%c">>, ClientId, MountPoint);
feed_var({<<"%u">>, undefined}, MountPoint) ->
MountPoint;
feed_var({<<"%u">>, Username}, MountPoint) ->
emqx_topic:feed_var(<<"%u">>, Username, MountPoint).