From 90246804d0b8e6fbcfddc7f99fb3b137239a8143 Mon Sep 17 00:00:00 2001
From: fallenoak <git@fallenoak.me>
Date: Sun, 1 Jan 2023 20:59:41 -0600
Subject: [PATCH] feat(handle): add handle functions

---
 common/Handle.cpp               | 36 +++++++++++++++++++++++++++++++++
 common/Handle.hpp               | 24 ++++++++++++++++++++++
 common/handle/CHandleObject.hpp | 15 ++++++++++++++
 test/Handle.cpp                 | 15 ++++++++++++++
 4 files changed, 90 insertions(+)
 create mode 100644 common/Handle.cpp
 create mode 100644 common/Handle.hpp
 create mode 100644 common/handle/CHandleObject.hpp
 create mode 100644 test/Handle.cpp

diff --git a/common/Handle.cpp b/common/Handle.cpp
new file mode 100644
index 0000000..f12499b
--- /dev/null
+++ b/common/Handle.cpp
@@ -0,0 +1,36 @@
+#include "common/Handle.hpp"
+#include "common/handle/CHandleObject.hpp"
+#include <storm/Error.hpp>
+
+HOBJECT HandleCreate(CHandleObject* ptr) {
+    STORM_ASSERT(ptr);
+    STORM_VALIDATE(ptr, ERROR_INVALID_PARAMETER, nullptr);
+
+    ptr->m_refcount++;
+    return reinterpret_cast<HOBJECT>(ptr);
+}
+
+void HandleClose(HOBJECT handle) {
+    CHandleObject* ptr = HandleDereference(handle);
+
+    STORM_ASSERT(ptr->m_refcount > 0);
+
+    ptr->m_refcount--;
+
+    if (ptr->m_refcount == 0) {
+        delete ptr;
+    }
+}
+
+CHandleObject* HandleDereference(HOBJECT handle) {
+    return reinterpret_cast<CHandleObject*>(handle);
+}
+
+HOBJECT HandleDuplicate(HOBJECT handle) {
+    if (!handle) {
+        return nullptr;
+    }
+
+    HandleDereference(handle)->m_refcount++;
+    return handle;
+}
diff --git a/common/Handle.hpp b/common/Handle.hpp
new file mode 100644
index 0000000..b3b26ee
--- /dev/null
+++ b/common/Handle.hpp
@@ -0,0 +1,24 @@
+#ifndef COMMON_HANDLE_HPP
+#define COMMON_HANDLE_HPP
+
+#include "common/handle/CHandleObject.hpp"
+#include <cstddef>
+#include <cstdint>
+
+typedef void* HANDLE;
+
+#define DECLARE_HANDLE(name) \
+    struct name##__;         \
+    typedef struct name##__* name
+
+DECLARE_HANDLE(HOBJECT);
+
+HOBJECT HandleCreate(CHandleObject* ptr);
+
+void HandleClose(HOBJECT handle);
+
+CHandleObject* HandleDereference(HOBJECT handle);
+
+HOBJECT HandleDuplicate(HOBJECT handle);
+
+#endif
diff --git a/common/handle/CHandleObject.hpp b/common/handle/CHandleObject.hpp
new file mode 100644
index 0000000..605adae
--- /dev/null
+++ b/common/handle/CHandleObject.hpp
@@ -0,0 +1,15 @@
+#ifndef COMMON_HANDLE_C_HANDLE_OBJECT_HPP
+#define COMMON_HANDLE_C_HANDLE_OBJECT_HPP
+
+#include <cstdint>
+
+class CHandleObject {
+    public:
+    // Member variables
+    int32_t m_refcount = 0;
+
+    // Virtual member functions
+    virtual ~CHandleObject() = default;
+};
+
+#endif
diff --git a/test/Handle.cpp b/test/Handle.cpp
new file mode 100644
index 0000000..11fe70d
--- /dev/null
+++ b/test/Handle.cpp
@@ -0,0 +1,15 @@
+#include "common/Handle.hpp"
+#include "test/Test.hpp"
+
+class TestHandleObject : public CHandleObject {};
+
+TEST_CASE("HandleCreate", "[handle]") {
+    SECTION("returns handle for subclass of CHandleObject") {
+        auto testObject = new TestHandleObject();
+
+        auto handle = HandleCreate(testObject);
+        CHECK(handle);
+
+        HandleClose(handle);
+    }
+}