| % 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. |
| |
| |
| % This causes an OS process to spawned and it is notified every time a database |
| % is updated. |
| % |
| % The notifications are in the form of a the database name sent as a line of |
| % text to the OS processes stdout. |
| |
| |
| -module(couch_event_os_sup). |
| -behaviour(supervisor). |
| -behaviour(config_listener). |
| |
| -vsn(2). |
| |
| -export([ |
| start_link/0, |
| init/1 |
| ]). |
| |
| -export([ |
| handle_config_change/5, |
| handle_config_terminate/3 |
| ]). |
| |
| |
| start_link() -> |
| supervisor:start_link({local, ?MODULE}, ?MODULE, []). |
| |
| |
| init([]) -> |
| UpdateNotifierExes = config:get("update_notification"), |
| Children = [ |
| { |
| config_listener_mon, |
| {config_listener_mon, start_link, [?MODULE, nil]}, |
| permanent, |
| 5000, |
| worker, |
| [config_listener_mon] |
| } |
| | [child(Id, Exe) || {Id, Exe} <- UpdateNotifierExes]], |
| |
| {ok, { |
| {one_for_one, 10, 3600}, |
| Children |
| }}. |
| |
| |
| handle_config_change("update_notification", Id, deleted, _, _) -> |
| supervisor:terminate_child(?MODULE, Id), |
| supervisor:delete_child(?MODULE, Id), |
| {ok, nil}; |
| handle_config_change("update_notification", Id, Exe, _, _) when is_list(Exe) -> |
| supervisor:start_child(?MODULE, child(Id, Exe)), |
| {ok, nil}; |
| handle_config_change(_, _, _, _, _) -> |
| {ok, nil}. |
| |
| handle_config_terminate(_Server, _Reason, _State) -> |
| ok. |
| |
| child(Id, Arg) -> |
| { |
| Id, |
| {couch_event_os_listener, start_link, [Arg]}, |
| permanent, |
| 1000, |
| supervisor, |
| [couch_event_os_listener] |
| }. |