1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
|
% 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]
}.
|
