From be6e770876f5aad290bf5b7109ca1aa306bf02cf Mon Sep 17 00:00:00 2001
From: KingToolbox <kingtoolbox@yandex.com>
Date: Thu, 11 Mar 2021 23:23:21 +0800
Subject: [PATCH] A smart memory pointer.

---
 src/README.md               |   4 ++
 src/Utility/MemoryPointer.h | 140 ++++++++++++++++++++++++++++++++++++
 2 files changed, 144 insertions(+)
 create mode 100644 src/Utility/MemoryPointer.h

diff --git a/src/README.md b/src/README.md
index 35db2ac..5bbb954 100644
--- a/src/README.md
+++ b/src/README.md
@@ -30,6 +30,10 @@ A quick circular buffer template class.
 
 A very safe encryption class using the PBKDF2-algorithm as defined in RFC 8018. WindTerm uses this class together with the user's master password to protect user data, including passwords, private keys and so on.
 
+## Utility/MemoryPointer.h
+
+A smart memory pointer.
+
 ## Utility/ScopeGuard.h
 
 A class of which the sole purpose is to run the function f in its destructor. This is useful for guaranteeing your cleanup code is executed.
diff --git a/src/Utility/MemoryPointer.h b/src/Utility/MemoryPointer.h
new file mode 100644
index 0000000..b5edb07
--- /dev/null
+++ b/src/Utility/MemoryPointer.h
@@ -0,0 +1,140 @@
+#ifndef MEMORYPOINTER_H
+#define MEMORYPOINTER_H
+
+#pragma once
+
+#include <QtGlobal>
+
+template <typename T>
+struct MemoryPointer {
+	typedef decltype(nullptr) nullptr_t;
+
+public:
+	MemoryPointer()
+		: uMemory({ 0 })
+	{}
+
+	MemoryPointer(const MemoryPointer &other) = delete;
+	MemoryPointer &MemoryPointer::operator=(const MemoryPointer &other) = delete;
+
+	MemoryPointer &MemoryPointer::operator=(nullptr_t) noexcept {
+		free();
+
+		uMemory = { 0 };
+		return (*this);
+	}
+
+	MemoryPointer(MemoryPointer &&other) noexcept {
+		uMemory = other.uMemory;
+		other.uMemory = { 0 };
+	}
+
+	MemoryPointer& MemoryPointer::operator=(MemoryPointer &&other) noexcept	{
+		if (this != &other) {
+			free();
+			
+			uMemory = other.uMemory;
+			other.uMemory = { 0 };
+		}
+		return (*this);
+	}
+
+	~MemoryPointer() {
+		free();
+	}
+
+	inline T *data() const {
+		return static_cast<T *>(uMemory.pointer);
+	}
+
+	inline T *operator->() const {
+		return data();
+	}
+
+	inline T &operator*() const {
+		return *data();
+	}
+
+	inline operator T*() const {
+		return data();
+	}
+
+	inline operator bool() const noexcept {
+		return data() != nullptr;
+	}
+
+	inline bool isNull() const {
+		return uMemory.pointer == NULL;
+	}
+
+private:
+	void free() {
+		if (uMemory.alloced) {
+			::free(reinterpret_cast<void *>(uMemory.pointer));
+			uMemory = { 0 };
+		}
+	}
+
+private:
+	union MemoryUnion {
+		quint64 value;
+
+		struct {
+			quint64 alloced : 1;
+			quint64 pointer : 48;
+		};
+	};
+	MemoryUnion uMemory;
+};
+
+template <class T>
+inline bool operator==(const T *o, const MemoryPointer<T> &p) {
+	return o == p.operator->();
+}
+
+template<class T>
+inline bool operator==(const MemoryPointer<T> &p, const T *o) {
+	return p.operator->() == o;
+}
+
+template <class T>
+inline bool operator==(T *o, const MemoryPointer<T> &p) {
+	return o == p.operator->();
+}
+
+template<class T>
+inline bool operator==(const MemoryPointer<T> &p, T *o) {
+	return p.operator->() == o;
+}
+
+template<class T>
+inline bool operator==(const MemoryPointer<T> &lhs, const MemoryPointer<T> &rhs) {
+	return lhs.operator->() == rhs.operator->();
+}
+
+template <class T>
+inline bool operator!=(const T *o, const MemoryPointer<T> &p) {
+	return o != p.operator->();
+}
+
+template<class T>
+inline bool operator!= (const MemoryPointer<T> &p, const T *o) {
+	return p.operator->() != o;
+}
+
+template <class T>
+inline bool operator!=(T *o, const MemoryPointer<T> &p) {
+	return o != p.operator->();
+}
+
+template<class T>
+inline bool operator!= (const MemoryPointer<T> &p, T *o) {
+	return p.operator->() != o;
+}
+
+template<class T>
+inline bool operator!= (const MemoryPointer<T> &lhs, const MemoryPointer<T> &rhs) {
+	return lhs.operator->() != rhs.operator->();
+}
+
+#endif // MEMORYPOINTER_H
\ No newline at end of file