// 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.

// This file is copied from

#pragma once

#include <atomic>

#include <cstdint>

#include <string>

#include "common/compiler_util.h"

#include "util/pretty_printer.h"

namespace doris {

/*

 * A counter that keeps track of the current and peak memory usage seen.

 * Relaxed ordering, not accurate in real time.

 *

 * This class is thread-safe.

*/

class MemCounter {

public:

    MemCounter() = default;

    void add(int64_t delta) {

        if (UNLIKELY(delta == 0)) {

            return;

        }

        int64_t value = _current_value.fetch_add(delta, std::memory_order_relaxed) + delta;

        update_peak(value);

    }

    void add_no_update_peak(int64_t delta) { // need extreme fast

        _current_value.fetch_add(delta, std::memory_order_relaxed);

    }

    bool try_add(int64_t delta, int64_t max) {

        if (UNLIKELY(delta == 0)) {

            return true;

        }

        int64_t cur_val = _current_value.load(std::memory_order_relaxed);

        int64_t new_val = 0;

        do {

            new_val = cur_val + delta;

            if (UNLIKELY(new_val > max)) {

                return false;

            }

        } while (UNLIKELY(!_current_value.compare_exchange_weak(cur_val, new_val,

                                                                std::memory_order_relaxed)));

        update_peak(new_val);

        return true;

    }

    void sub(int64_t delta) { _current_value.fetch_sub(delta, std::memory_order_relaxed); }

    void set(int64_t v) {

        _current_value.store(v, std::memory_order_relaxed);

        update_peak(v);

    }

    void update_peak(int64_t value) {

        int64_t pre_value = _peak_value.load(std::memory_order_relaxed);

        while (value > pre_value &&

               !_peak_value.compare_exchange_weak(pre_value, value, std::memory_order_relaxed)) {

        }

    }

    int64_t current_value() const { return _current_value.load(std::memory_order_relaxed); }

    int64_t peak_value() const { return _peak_value.load(std::memory_order_relaxed); }

private:

    std::atomic<int64_t> _current_value {0};

    std::atomic<int64_t> _peak_value {0};

};

} // namespace doris