81 lines
1.7 KiB
C++
81 lines
1.7 KiB
C++
/*
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* Util.h
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef _FLOW_UTIL_H_
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#define _FLOW_UTIL_H_
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#pragma once
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#include <algorithm>
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template <typename C>
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void swapAndPop(C* container, int index) {
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if (index != container->size()-1) {
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using std::swap;
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swap((*container)[index], container->back());
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}
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container->pop_back();
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}
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// Adds n to pCount upon construction, subtracts in upon destruction
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template<typename T>
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struct Hold {
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Hold(T *pCount = nullptr, T n = 1) : pCount(pCount), n(n) {
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if(pCount != nullptr) {
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*pCount += n;
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}
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}
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~Hold() {
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if(pCount != nullptr) {
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*pCount -= n;
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}
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}
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Hold(Hold &&other) {
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pCount = other.pCount;
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other.pCount = nullptr;
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n = other.n;
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}
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Hold & operator=(Hold &&other) {
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if(pCount != nullptr) {
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*pCount -= n;
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}
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pCount = other.pCount;
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other.pCount = nullptr;
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n = other.n;
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return *this;
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};
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void release() {
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if(pCount != nullptr) {
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*pCount -= n;
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pCount = nullptr;
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}
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}
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T *pCount;
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T n;
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void operator=(const Hold &other) = delete;
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};
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#endif // _FLOW_UTIL_H_
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