add emqttd_time module

src/emqttd_time.erl

@@ -0,0 +1,36 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2012-2016 Feng Lee <feng@emqtt.io>.
+%%
+%% 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(emqttd_time).
+
+-export([seed/0, now_to_secs/0, now_to_secs/1, now_to_ms/0, now_to_ms/1]).
+
+seed() ->
+    case erlang:function_exported(erlang, timestamp, 0) of
+        true  -> random:seed(erlang:timestamp()); %% R18
+        false -> random:seed(os:timestamp()) %% Compress now() deprecated warning...
+    end.
+
+now_to_secs() -> now_to_secs(os:timestamp()).
+
+now_to_secs({MegaSecs, Secs, _MicroSecs}) ->
+    MegaSecs * 1000000 + Secs.
+
+now_to_ms() -> now_to_ms(os:timestamp()).
+
+now_to_ms({MegaSecs, Secs, MicroSecs}) ->
+    (MegaSecs * 1000000 + Secs) * 1000 + round(MicroSecs/1000).
+

test/emqttd_time_tests.erl

@@ -0,0 +1,29 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2016 Feng Lee <feng@emqtt.io>.
+%%
+%% 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(emqttd_time_tests).
+
+-ifdef(TEST).
+
+-include_lib("eunit/include/eunit.hrl").
+
+test_() ->
+    emqttd_time:seed(),
+    emqttd_time:now_to_secs(),
+    emqttd_time:now_to_ms().
+
+-endif.
+