%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2015-2015. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%

%% This module is created to be able to execute on ERTS versions both
%% earlier and later than 7.0.

-module(inets_time_compat).

%% We don't want warnings about the use of erlang:now/0 in
%% this module.
-compile(nowarn_deprecated_function).

-export([monotonic_time/0,
         timestamp/0,
         unique_integer/0,
         unique_integer/1]).

monotonic_time() ->
    try
	erlang:monotonic_time()
    catch
	error:undef ->
	    %% Use Erlang system time as monotonic time
	    erlang_system_time_fallback()
    end.

timestamp() ->
    try
	erlang:timestamp()
    catch
	error:undef ->
	    erlang:now()
    end.

unique_integer() ->
    try
	erlang:unique_integer()
    catch
	error:undef ->
            erlang_system_time_fallback()
    end.

unique_integer(Modifiers) ->
    try
	erlang:unique_integer(Modifiers)
    catch
	error:badarg ->
	    erlang:error(badarg, [Modifiers]);
	error:undef ->
            erlang_system_time_fallback()
    end.

erlang_system_time_fallback() ->
    {MS, S, US} = erlang:now(),
    (MS*1000000+S)*1000000+US.