109 lines
2.7 KiB
C++
109 lines
2.7 KiB
C++
/*
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* ReferenceCounted.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 FDB_REFERENCE_COUNTED_H
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#define FDB_REFERENCE_COUNTED_H
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#pragma once
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#include <stdlib.h>
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template <class T>
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struct ReferenceCounted {
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void addref() { ++referenceCount; }
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void delref() { if (--referenceCount == 0) { delete (T*)this; } }
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ReferenceCounted() : referenceCount(1) {}
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private:
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ReferenceCounted(const ReferenceCounted&) = delete;
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void operator=(const ReferenceCounted&) = delete;
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int32_t referenceCount;
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};
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template <class P>
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void addref(P* ptr) { ptr->addref(); }
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template <class P>
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void delref(P* ptr) { ptr->delref(); }
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template <class P>
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struct Reference {
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Reference() : ptr(NULL) {}
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explicit Reference( P* ptr ) : ptr(ptr) {}
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static Reference<P> addRef( P* ptr ) { ptr->addref(); return Reference(ptr); }
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Reference(const Reference& r) : ptr(r.getPtr()) { if (ptr) addref(ptr); }
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Reference(Reference && r) : ptr(r.getPtr()) { r.ptr = NULL; }
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template <class Q>
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Reference(const Reference<Q>& r) : ptr(r.getPtr()) { if (ptr) addref(ptr); }
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template <class Q>
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Reference(Reference<Q> && r) : ptr(r.getPtr()) { r.setPtrUnsafe(NULL); }
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~Reference() { if (ptr) delref(ptr); }
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Reference& operator=(const Reference& r) {
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P* oldPtr = ptr;
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P* newPtr = r.ptr;
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if (oldPtr != newPtr) {
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if (newPtr) addref(newPtr);
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ptr = newPtr;
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if (oldPtr) delref(oldPtr);
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}
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return *this;
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}
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Reference& operator=(Reference&& r) {
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P* oldPtr = ptr;
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P* newPtr = r.ptr;
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if (oldPtr != newPtr) {
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r.ptr = NULL;
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ptr = newPtr;
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if (oldPtr) delref(oldPtr);
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}
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return *this;
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}
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void clear() {
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P* oldPtr = ptr;
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if (oldPtr) {
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ptr = NULL;
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delref(oldPtr);
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}
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}
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P* operator->() const { return ptr; }
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P& operator*() const { return *ptr; }
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P* getPtr() const { return ptr; }
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void setPtrUnsafe( P* p ) { ptr = p; }
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P* extractPtr() { auto *p = ptr; ptr = NULL; return p; }
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bool boolean_test() const { return ptr != 0; }
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private:
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P *ptr;
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};
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template <class P>
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bool operator==( const Reference<P>& lhs, const Reference<P>& rhs ) {
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return lhs.getPtr() == rhs.getPtr();
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}
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#endif /* FDB_REFERENCE_COUNTED_H */
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