73 lines
1.5 KiB
Erlang
73 lines
1.5 KiB
Erlang
%% -------------------------------------------------------------------
|
|
%%
|
|
%% Machi: a small village of replicated files
|
|
%%
|
|
%% Copyright (c) 2014 Basho Technologies, Inc. All Rights Reserved.
|
|
%%
|
|
%% This file is provided to you 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(lamport_clock).
|
|
|
|
-export([init/0, reset/0, get/0, update/1, incr/0]).
|
|
|
|
-define(KEY, ?MODULE).
|
|
|
|
-ifdef(TEST).
|
|
|
|
init() ->
|
|
case get(?KEY) of
|
|
undefined ->
|
|
reset();
|
|
N when is_integer(N) ->
|
|
ok
|
|
end.
|
|
|
|
reset() ->
|
|
FakeTOD = 0,
|
|
put(?KEY, FakeTOD + 1).
|
|
|
|
get() ->
|
|
init(),
|
|
get(?KEY).
|
|
|
|
update(Remote) ->
|
|
New = erlang:max(get(?KEY), Remote) + 1,
|
|
put(?KEY, New),
|
|
New.
|
|
|
|
incr() ->
|
|
New = get(?KEY) + 1,
|
|
put(?KEY, New),
|
|
New.
|
|
|
|
-else. % TEST
|
|
|
|
init() ->
|
|
ok.
|
|
|
|
reset() ->
|
|
ok.
|
|
|
|
get() ->
|
|
ok.
|
|
|
|
update(_) ->
|
|
ok.
|
|
|
|
incr() ->
|
|
ok.
|
|
|
|
-endif. % TEST
|