reorganize couch .erl and driver code into rebar layout

1 files changed, 63 insertions, 0 deletions

diff --git a/apps/couch/src/couch_db_update_notifier_sup.erl b/apps/couch/src/couch_db_update_notifier_sup.erl
new file mode 100644
index 00000000..4d730fc7
--- /dev/null
+++ b/apps/couch/src/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).
+