// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you 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.

#pragma once

#include <mutex>

#include "storage/olap_common.h"

namespace doris {

class PendingRowsetSet;

class [[nodiscard]] PendingRowsetGuard {

public:

    PendingRowsetGuard() = default;

    // Remove guarded rowset id from `PendingRowsetSet` if it's initialized

    ~PendingRowsetGuard();

    PendingRowsetGuard(const PendingRowsetGuard&) = delete;

    PendingRowsetGuard& operator=(const PendingRowsetGuard&) = delete;

    PendingRowsetGuard(PendingRowsetGuard&& other) noexcept;

    PendingRowsetGuard& operator=(PendingRowsetGuard&& other) noexcept;

    // Remove guarded rowset id from `PendingRowsetSet` if it's initialized and reset the guard to

    // uninitialized state. This be used to manually release the pending rowset, ensure that the

    // guarded rowset is indeed no longer in use.

    void drop();

private:

    friend class PendingRowsetSet;

    explicit PendingRowsetGuard(const RowsetId& rowset_id, PendingRowsetSet* set);

    RowsetId _rowset_id;

    PendingRowsetSet* _pending_rowset_set = nullptr;

};

// Pending rowsets refer to those rowsets that are under construction, and have not been added to

// the tablet. BE storage engine will skip these pending rowsets during garbage collection.

class PendingRowsetSet {

public:

    bool contains(const RowsetId& rowset_id);

    // Developers MUST add the rowset id to `PendingRowsetSet` before writing first row data to a

    // local rowset, and hold returned `PendingRowsetGuard` during rowset construction before

    // adding the rowset to tablet. rowset id will be removed from `PendingRowsetSet` eventually

    // when `PendingRowsetGuard` is destroyed.

    PendingRowsetGuard add(const RowsetId& rowset_id);

private:

    friend class PendingRowsetGuard;

    void remove(const RowsetId& rowset_id);

    // TODO(plat1ko): Use high concurrency data structure

    std::mutex _mtx;

    RowsetIdUnorderedSet _set;

};

} // namespace doris