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Diffstat (limited to '1.1.x/src/couchdb/couch_db_update_notifier_sup.erl')
-rw-r--r-- | 1.1.x/src/couchdb/couch_db_update_notifier_sup.erl | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/1.1.x/src/couchdb/couch_db_update_notifier_sup.erl b/1.1.x/src/couchdb/couch_db_update_notifier_sup.erl new file mode 100644 index 00000000..4d730fc7 --- /dev/null +++ b/1.1.x/src/couchdb/couch_db_update_notifier_sup.erl @@ -0,0 +1,63 @@ +% 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_db_update_notifier_sup). + +-behaviour(supervisor). + +-export([start_link/0,init/1]). + +start_link() -> + supervisor:start_link({local, couch_db_update_notifier_sup}, + couch_db_update_notifier_sup, []). + +init([]) -> + ok = couch_config:register( + fun("update_notification", Key, Value) -> reload_config(Key, Value) end + ), + + UpdateNotifierExes = couch_config:get("update_notification"), + + {ok, + {{one_for_one, 10, 3600}, + lists:map(fun({Name, UpdateNotifierExe}) -> + {Name, + {couch_db_update_notifier, start_link, [UpdateNotifierExe]}, + permanent, + 1000, + supervisor, + [couch_db_update_notifier]} + end, UpdateNotifierExes)}}. + +%% @doc when update_notification configuration changes, terminate the process +%% for that notifier and start a new one with the updated config +reload_config(Id, Exe) -> + ChildSpec = { + Id, + {couch_db_update_notifier, start_link, [Exe]}, + permanent, + 1000, + supervisor, + [couch_db_update_notifier] + }, + supervisor:terminate_child(couch_db_update_notifier_sup, Id), + supervisor:delete_child(couch_db_update_notifier_sup, Id), + supervisor:start_child(couch_db_update_notifier_sup, ChildSpec). + |