From e1229e05aba7554363b2aa9874bd383b5923ee8b Mon Sep 17 00:00:00 2001
From: Steven Le Rouzic <steven.lerouzic@gmail.com>
Date: Mon, 25 Mar 2024 23:28:26 +0100
Subject: Basic console API & API registry implementation

---
 deimos/core/BUILD            |  2 ++
 deimos/core/api_registry.cpp | 18 +++++++++++++++---
 deimos/core/api_registry.h   |  7 +++++++
 deimos/core/base.h           | 10 ++++++++++
 deimos/core/id_name.h        |  5 +++++
 5 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/deimos/core/BUILD b/deimos/core/BUILD
index cb76f90..2f0dc2d 100644
--- a/deimos/core/BUILD
+++ b/deimos/core/BUILD
@@ -6,10 +6,12 @@ cc_library(
         "base.h",
         "hash.h",
         "id_name.h",
+        "os.h",
     ],
     srcs = [
         "allocator.cpp",
         "api_registry.cpp",
+        "os_win32.cpp",
     ],
     visibility = ["//:__subpackages__"],
 )
diff --git a/deimos/core/api_registry.cpp b/deimos/core/api_registry.cpp
index 873d72d..1489484 100644
--- a/deimos/core/api_registry.cpp
+++ b/deimos/core/api_registry.cpp
@@ -7,6 +7,7 @@ namespace deimos
 {
 
 AllocatorApi* BootstrapAllocatorApi();
+void RegisterOsApi(ApiRegistry*);
 
 struct ApiEntry
 {
@@ -22,6 +23,7 @@ struct ApiEntry
 class ApiRegistryImpl: public ApiRegistry
 {
     Allocator* m_allocator;
+    const ApiEntry* m_head{};
 
 public:
     explicit ApiRegistryImpl(Allocator* allocator) :
@@ -30,9 +32,17 @@ public:
 
     void Set(const IdName& name, void* impl) final
     {
-        (void)name;
-        (void)impl;
-        (void)m_allocator;
+        auto* entry = m_allocator->New<ApiEntry>(name, impl);
+        entry->next = std::exchange(m_head, entry);
+    }
+
+    void* Get(const IdName& name) final
+    {
+        for (const ApiEntry* it = m_head; it != nullptr; it = it->next)
+        {
+            if (it->name == name) { return it->impl; }
+        }
+        return nullptr;
     }
 };
 
@@ -45,6 +55,8 @@ ApiRegistry* InitializeGlobalApiRegistry()
 
     api_registry->Set(g_allocator_api);
 
+    RegisterOsApi(api_registry);
+
     return api_registry;
 }
 
diff --git a/deimos/core/api_registry.h b/deimos/core/api_registry.h
index 2624935..f2f850a 100644
--- a/deimos/core/api_registry.h
+++ b/deimos/core/api_registry.h
@@ -15,8 +15,15 @@ public:
 
     virtual ~ApiRegistry() = default;
 
+    virtual void* Get(const IdName&) = 0;
     virtual void Set(const IdName&, void* impl) = 0;
 
+    template<typename Api>
+    Api* Get()
+    {
+        return (Api*)Get(Api::kApiName);
+    }
+
     template<typename Api>
     void Set(Api* impl)
     {
diff --git a/deimos/core/base.h b/deimos/core/base.h
index ea14610..0669f07 100644
--- a/deimos/core/base.h
+++ b/deimos/core/base.h
@@ -46,6 +46,8 @@ struct uint128
 {
     uint64 high;
     uint64 low;
+
+    constexpr bool operator==(const uint128& other) const = default;
 };
 
 struct SourceLocation
@@ -96,5 +98,13 @@ constexpr T&& forward(deimos::RemoveReference<T>&& t) noexcept // NOLINT
     return static_cast<T&&>(t);
 }
 
+template<typename T, typename U = T>
+constexpr T exchange(T& obj, U&& new_value)
+{
+    T old_value = std::move(obj);
+    obj = std::forward<U>(new_value);
+    return old_value;
+}
+
 } // namespace std
 
diff --git a/deimos/core/id_name.h b/deimos/core/id_name.h
index 0fb793b..47e7708 100644
--- a/deimos/core/id_name.h
+++ b/deimos/core/id_name.h
@@ -15,6 +15,11 @@ struct IdName
         hash{MurmurHash3_x64_128(name_)},
         name{name_}
     {}
+
+    constexpr bool operator==(const IdName& other) const
+    {
+        return hash == other.hash;
+    }
 };
 
 } // namespace deimos
-- 
cgit