--Copyright 2021 The casbin Authors. All Rights Reserved.
--
--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.

local Watcher = {}
Watcher.__index = Watcher

-- setUpdateCallback sets the callback function that the watcher will call
-- when the policy in DB has been changed by other instances.
-- A classic callback is Enforcer:loadPolicy().
function Watcher:setUpdateCallback(func)

end

-- update calls the update callback of other instances to synchronize their policy.
-- It is usually called after changing the policy in DB, like Enforcer:savePolicy(),
-- Enforcer:AddPolicy(), Enforcer:RemovePolicy(), etc.
function Watcher:update()

end

-- close stops and releases the watcher, the callback function will not be called any more.
function Watcher:close()

end

return Watcher