| % 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(couch_stats_gauge). |
| |
| -export([ |
| new/0, |
| update/2, |
| read/1 |
| ]). |
| |
| new() -> |
| counters:new(1, [write_concurrency]). |
| |
| update(Ctx, Val) when is_integer(Val) -> |
| counters:put(Ctx, 1, Val). |
| |
| read(Ctx) -> |
| counters:get(Ctx, 1). |
| |
| -ifdef(TEST). |
| |
| -include_lib("couch/include/couch_eunit.hrl"). |
| |
| counter_test() -> |
| G = new(), |
| |
| ?assertEqual(0, read(G)), |
| |
| update(G, 0), |
| ?assertEqual(0, read(G)), |
| |
| update(G, 1), |
| ?assertEqual(1, read(G)), |
| |
| update(G, 0), |
| ?assertEqual(0, read(G)), |
| |
| update(G, 1 bsl 10), |
| ?assertEqual(1 bsl 10, read(G)), |
| |
| update(G, -1), |
| ?assertEqual(-1, read(G)). |
| |
| -endif. |