Magpie/Runtime/Utils.h

#pragma once
#include "pch.h"
#include <bcrypt.h>


struct Utils {
	static UINT GetWindowShowCmd(HWND hwnd);

	static bool GetClientScreenRect(HWND hWnd, RECT& rect);

	static bool GetWindowFrameRect(HWND hWnd, RECT& result);

	static bool CheckOverlap(const RECT& r1, const RECT& r2) noexcept {
		return r1.right > r2.left && r1.bottom > r2.top && r1.left < r2.right&& r1.top < r2.bottom;
	}

	static SIZE GetSizeOfRect(const RECT& rect) {
		return { rect.right - rect.left, rect.bottom - rect.top };
	}

	// 单位为微秒
	template<typename Fn>
	static int Measure(const Fn& func) {
		using namespace std::chrono;

		auto t = steady_clock::now();
		func();
		auto dura = duration_cast<microseconds>(steady_clock::now() - t);

		return int(dura.count());
	}

	static bool ReadFile(const wchar_t* fileName, std::vector<BYTE>& result);

	static bool ReadTextFile(const wchar_t* fileName, std::string& result);

	static bool WriteFile(const wchar_t* fileName, const void* buffer, size_t bufferSize);

	static bool FileExists(const wchar_t* fileName) {
		DWORD attrs = GetFileAttributesW(fileName);
		// 排除文件夹
		return (attrs != INVALID_FILE_ATTRIBUTES) && !(attrs & FILE_ATTRIBUTE_DIRECTORY);
	}

	static bool DirExists(const wchar_t* fileName) {
		DWORD attrs = GetFileAttributesW(fileName);
		return (attrs != INVALID_FILE_ATTRIBUTES) && (attrs & FILE_ATTRIBUTE_DIRECTORY);
	}

	static const RTL_OSVERSIONINFOW& GetOSVersion();

	static int CompareVersion(int major1, int minor1, int build1, int major2, int minor2, int build2) {
		if (major1 != major2) {
			return major1 - major2;
		}

		if (minor1 != minor2) {
			return minor1 - minor2;
		} else {
			return build1 - build2;
		}
	}

	static std::string Bin2Hex(std::span<const BYTE> data);

	// CRITICAL_SECTION 的封装，满足基本可锁定要求（BasicLockable）
	// 因此可用于 std::scoped_lock 等
	class CSMutex {
	public:
		CSMutex() {
			InitializeCriticalSectionEx(&_cs, 4000, CRITICAL_SECTION_NO_DEBUG_INFO);
		}

		~CSMutex() {
			DeleteCriticalSection(&_cs);
		}

		void lock() {
			EnterCriticalSection(&_cs);
		}

		void unlock() {
			LeaveCriticalSection(&_cs);
		}

		CRITICAL_SECTION* get() {
			return &_cs;
		}
	private:
		CRITICAL_SECTION _cs{};
	};

	class Hasher {
	public:
		static Hasher& Get() {
			static Hasher instance;
			return instance;
		}

		bool Initialize();

		bool Hash(std::span<const BYTE> data, std::vector<BYTE>& result);

		DWORD GetHashLength() noexcept {
			return _hashLen;
		}
	private:
		~Hasher();

		CSMutex _cs;	// 同步对 Hash() 的访问

		BCRYPT_ALG_HANDLE _hAlg = NULL;
		DWORD _hashObjLen = 0;		// hash 对象的大小
		void* _hashObj = nullptr;	// 存储 hash 对象
		DWORD _hashLen = 0;			// 哈希结果的大小
		BCRYPT_HASH_HANDLE _hHash = NULL;
	};

	template<typename T>
	class ScopeExit {
	public:
		ScopeExit(const ScopeExit&) = delete;
		ScopeExit(ScopeExit&&) = delete;

		explicit ScopeExit(T&& exitScope) : _exitScope(std::forward<T>(exitScope)) {}
		~ScopeExit() { _exitScope(); }

	private:
		T _exitScope;
	};

	struct HandleCloser { void operator()(HANDLE h) noexcept { assert(h != INVALID_HANDLE_VALUE); if (h) CloseHandle(h); } };

	using ScopedHandle = std::unique_ptr<std::remove_pointer<HANDLE>::type, HandleCloser>;

	static HANDLE SafeHandle(HANDLE h) noexcept { return (h == INVALID_HANDLE_VALUE) ? nullptr : h; }

	// 并行执行 times 次 func，并行失败时回退到单线程
	// 执行完毕后返回
	static void RunParallel(std::function<void(UINT)> func, UINT times);

	static bool ZstdCompress(std::span<const BYTE> src, std::vector<BYTE>& dest, int compressionLevel);
	static bool ZstdDecompress(std::span<const BYTE> src, std::vector<BYTE>& dest);
};

namespace std {

// std::hash 的 std::pair 特化
template<typename T1, typename T2>
struct hash<std::pair<T1, T2>> {
	typedef std::pair<T1, T2> argument_type;
	typedef std::size_t result_type;
	result_type operator()(argument_type const& s) const {
		result_type const h1(std::hash<T1>()(s.first));
		result_type const h2(std::hash<T2>{}(s.second));
		return h1 ^ (h2 << 1);
	}
};

}