refactor(com): move com utils to shared/

cxx-shared/shared/com.hpp

@@ -0,0 +1,121 @@
+#pragma once
+#include <Windows.h>
+
+#include "shared/strings.hpp"
+
+#include <cstdint>
+#include <format>
+#include <print>
+#include <source_location>
+#include <stdexcept>
+
+namespace com {
+    inline HRESULT checked(HRESULT result, const std::source_location loc = std::source_location::current()) {
+        if (result == 0) {
+            return result;
+        }
+
+        auto msg = std::format("Got HRESULT={:#x} at\n{}:{}", static_cast<std::uint32_t>(result) & 0xFFFFFFFF, loc.function_name(), loc.line());
+        throw std::runtime_error(msg);
+    }
+
+    template <typename Callable>
+    inline HRESULT retry_while_pending(Callable&& fn) {
+        bool delayed = false;
+        HRESULT status = 0;
+        do {
+            if (status != 0) {
+                delayed = true;
+                std::println("delaying for com retry...");
+                std::this_thread::sleep_for(std::chrono::milliseconds(500));
+            }
+
+            status = fn();
+        } while (status == E_PENDING);
+
+        return status;
+    }
+
+    /// A very basic implementation, a lot of stuff is missing
+    template <typename Ty>
+    class Ptr {
+    public:
+        Ptr() = default;
+        explicit Ptr(Ty* ptr): ptr_(ptr) { }
+
+        ~Ptr() {
+            release();
+        }
+
+        /// No copying
+        Ptr(const Ptr&) = delete;
+        Ptr& operator=(const Ptr&) = delete;
+
+        /// Move
+        Ptr(Ptr&& other) noexcept: ptr_(other.ptr_) {
+            other.ptr_ = nullptr;
+        }
+        Ptr& operator=(Ptr&& other) noexcept {
+            if (this != &other) {
+                release();
+                ptr_ = other.ptr_;
+                other.ptr_ = nullptr;
+            }
+            return *this;
+        }
+
+    public:
+        [[nodiscard]] Ty* get() const {
+            return ptr_;
+        }
+
+        [[nodiscard]] Ty* operator->() const {
+            return ptr_;
+        }
+
+        [[nodiscard]] Ty** ref_to_ptr() {
+            return &ptr_;
+        }
+
+    private:
+        void release() {
+            if (ptr_ != nullptr) {
+                ptr_->Release();
+            }
+        }
+
+        Ty* ptr_ = nullptr;
+    };
+
+    template <GUID ClsId, GUID IID>
+    class IBaseObject {
+    public:
+        static constexpr GUID kClsId = ClsId;
+        static constexpr GUID kIID = IID;
+
+    private:
+        virtual HRESULT QueryInterface() = 0;
+        virtual std::uint32_t AddRef() = 0;
+
+    public:
+        virtual std::uint32_t Release() = 0;
+    };
+
+    template <typename Ty>
+    concept ComObject = requires {
+        Ty::kClsId;
+        Ty::kIID;
+    };
+
+    template <ComObject Ty>
+    [[nodiscard]] Ptr<Ty> query() {
+        Ptr<Ty> result;
+        const auto status = CoCreateInstance(Ty::kClsId, 0, 1, Ty::kIID, reinterpret_cast<LPVOID*>(result.ref_to_ptr()));
+        if (status == REGDB_E_CLASSNOTREG) {
+            throw std::runtime_error(strings::wsc_unavailable_error().data());
+        }
+
+        checked(status);
+        return result;
+    }
+} // namespace com