4e553b692e
Feature lifetime is tied to storage_service lifetime, but features are now managed by gossip. To avoid circular dependency, add a new feature_service service to manage feature lifetime. To work around the problem, the current code re-initializes features after gossip is initialized. This patch does not fix this problem; it only makes it possible to solve it by untyping features from gossip.
62 lines
1.7 KiB
C++
62 lines
1.7 KiB
C++
/*
|
|
* Copyright (C) 2016 ScyllaDB
|
|
*/
|
|
|
|
/*
|
|
* This file is part of Scylla.
|
|
*
|
|
* Scylla is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU Affero General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* Scylla is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <seastar/core/shared_future.hh>
|
|
|
|
namespace gms {
|
|
|
|
class feature_service;
|
|
|
|
/**
|
|
* A gossip feature tracks whether all the nodes the current one is
|
|
* aware of support the specified feature.
|
|
*
|
|
* A feature should only be created once the gossiper is available.
|
|
*/
|
|
class feature final {
|
|
feature_service* _service = nullptr;
|
|
sstring _name;
|
|
bool _enabled = false;
|
|
mutable shared_promise<> _pr;
|
|
friend class gossiper;
|
|
public:
|
|
explicit feature(feature_service& service, sstring name, bool enabled = false);
|
|
feature() = default;
|
|
~feature();
|
|
feature(const feature& other) = delete;
|
|
void enable();
|
|
feature& operator=(feature&& other);
|
|
const sstring& name() const {
|
|
return _name;
|
|
}
|
|
explicit operator bool() const {
|
|
return _enabled;
|
|
}
|
|
friend inline std::ostream& operator<<(std::ostream& os, const feature& f) {
|
|
return os << "{ gossip feature = " << f._name << " }";
|
|
}
|
|
future<> when_enabled() const { return _pr.get_shared_future(); }
|
|
};
|
|
|
|
} // namespace gms
|