++

Author: Damir Zainullin

include/ipfixprobe/outputPlugin/outputStorage/referenceCounter.hpp

@@ -0,0 +1,93 @@
+#pragma once
+
+//#include "outputContainer.hpp"
+
+#include <atomic>
+#include <cstddef>
+#include <iostream>
+
+template<typename T>
+class ReferenceCounter {
+public:
+	/*explicit ReferenceCounter(T data) noexcept
+		: m_data(std::move(data))
+	{
+	}*/
+
+	explicit ReferenceCounter() noexcept
+		: m_data()
+	{
+	}
+
+	ReferenceCounter& operator=(const ReferenceCounter&) = delete;
+	ReferenceCounter(const ReferenceCounter&) = delete;
+
+	T& getData() noexcept { return m_data; }
+
+	void incrementUserCount() noexcept { m_refCount++; }
+
+	void decrementUserCount()
+	{
+		if (m_refCount == 0) {
+			throw std::runtime_error(
+				"ReferenceCounterHandler destructor called but user count is already zero.");
+		}
+		const uint8_t refCount = m_refCount--;
+		if (refCount == 0) {
+			m_data.~T();
+		}
+	}
+
+	bool hasUsers() const noexcept { return m_refCount.load() > 0; }
+
+private:
+	T m_data;
+	std::atomic_uint8_t m_refCount {0};
+};
+
+template<typename T>
+class Reference {
+public:
+	explicit Reference(ReferenceCounter<T>& counter) noexcept
+		: m_counter(&counter)
+	{
+		m_counter->incrementUserCount();
+	}
+
+	auto&& getData(this auto&& self) noexcept { return self.m_counter->getData(); }
+
+	Reference(const Reference& other) noexcept
+		: Reference(*other.m_counter)
+	{
+	}
+
+	/*Reference& operator=(const Reference& other) noexcept
+	{
+		if (this != &other) {
+			m_counter->decrementUserCount();
+			m_counter = other.m_counter;
+			m_counter->incrementUserCount();
+		}
+		return *this;
+	}*/
+
+	void assign(const Reference& other, 
+		AllocationBufferBase<ReferenceCounter<T>>& allocationBuffer) noexcept
+	{
+		if (this != &other) {
+			return;	
+		}	
+		const uint8_t userCount = m_counter->decrementUserCount();
+		if (userCount == 0) {
+			allocationBuffer.deallocate(m_counter);
+		}
+		m_counter = other.m_counter;
+		m_counter->incrementUserCount();
+	
+	}
+
+	~Reference() noexcept { m_counter->decrementUserCount(); }
+
+private:
+	ReferenceCounter<T>* m_counter;
+};