fcb8d040e8
Instead of lengthy blurbs, switch to single-line, machine-readable standardized (https://spdx.dev) license identifiers. The Linux kernel switched long ago, so there is strong precedent. Three cases are handled: AGPL-only, Apache-only, and dual licensed. For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0), reasoning that our changes are extensive enough to apply our license. The changes we applied mechanically with a script, except to licenses/README.md. Closes #9937
92 lines
1.8 KiB
C++
92 lines
1.8 KiB
C++
/*
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* Copyright (C) 2018-present ScyllaDB
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*/
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/*
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* SPDX-License-Identifier: AGPL-3.0-or-later
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*/
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#pragma once
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#include <functional>
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#include <limits>
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namespace detail {
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template<typename T, typename Comparator>
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class extremum_tracker {
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T _default_value;
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bool _is_set = false;
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T _value;
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public:
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explicit extremum_tracker(T default_value) {
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_default_value = default_value;
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}
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void update(T value) {
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if (!_is_set) {
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_value = value;
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_is_set = true;
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} else {
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if (Comparator{}(value,_value)) {
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_value = value;
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}
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}
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}
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void update(const extremum_tracker& other) {
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if (other._is_set) {
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update(other._value);
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}
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}
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T get() const {
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if (_is_set) {
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return _value;
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}
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return _default_value;
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}
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};
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} // namespace detail
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template <typename T>
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using min_tracker = detail::extremum_tracker<T, std::less<T>>;
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template <typename T>
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using max_tracker = detail::extremum_tracker<T, std::greater<T>>;
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template <typename T>
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class min_max_tracker {
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min_tracker<T> _min_tracker;
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max_tracker<T> _max_tracker;
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public:
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min_max_tracker()
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: _min_tracker(std::numeric_limits<T>::min())
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, _max_tracker(std::numeric_limits<T>::max())
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{}
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min_max_tracker(T default_min, T default_max)
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: _min_tracker(default_min)
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, _max_tracker(default_max)
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{}
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void update(T value) {
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_min_tracker.update(value);
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_max_tracker.update(value);
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}
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void update(const min_max_tracker<T>& other) {
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_min_tracker.update(other._min_tracker);
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_max_tracker.update(other._max_tracker);
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}
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T min() const {
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return _min_tracker.get();
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}
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T max() const {
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return _max_tracker.get();
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}
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};
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