From eb4df5d8e885c7597e92d7579af14145a66ff200 Mon Sep 17 00:00:00 2001
From: mnerv <24420859+mnerv@users.noreply.github.com>
Date: Sun, 16 Jun 2024 23:56:10 +0200
Subject: [PATCH] Initial commit

---
 .editorconfig  | 21 +++++++++++++++
 .gitignore     | 40 ++++++++++++++++++++++++++++
 CMakeLists.txt | 39 +++++++++++++++++++++++++++
 helloalloc.cpp | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 171 insertions(+)
 create mode 100644 .editorconfig
 create mode 100644 .gitignore
 create mode 100644 CMakeLists.txt
 create mode 100644 helloalloc.cpp

diff --git a/.editorconfig b/.editorconfig
new file mode 100644
index 0000000..8dbbd2a
--- /dev/null
+++ b/.editorconfig
@@ -0,0 +1,21 @@
+[*]
+end_of_line  = LF
+charset      = utf-8
+indent_style = space
+indent_size  = 4
+insert_final_newline = true
+
+[*.{ts,js,tsx,jsx,lua,yml,json}]
+charset      = utf-8
+indent_style = space
+indent_size  = 2
+
+[*.go]
+indent_style = tab
+
+[Makefile]
+indent_style = tab
+
+[meson.build]
+indent_size  = 2
+
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..addec9e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,40 @@
+# Binaries
+bin
+obj
+
+# CMake
+build
+cmake-build-*
+meson-build-*
+
+# Xcode
+*.xcworkspace
+*.xcodeproj
+
+# Visual Studio
+*.sln
+*.vcxproj
+*.vcxproj.filters
+*.vcxproj.user
+.vs
+
+# Makefile
+Makefile
+*.make
+
+# nvim
+.ccls
+.ccls-cache
+compile_commands.json
+
+# Visual Studio Code
+.vscode
+
+# IntelliJ
+.idea
+
+# macOS
+.DS_Store
+.AppleDouble
+.LSOverride
+
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..c7a87b9
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,39 @@
+cmake_minimum_required(VERSION 3.12)
+project(helloalloc VERSION 0.0.0)
+set_property(GLOBAL PROPERTY USE_FOLDERS ON)  # Group CMake targets inside a folder
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)         # Generate compile_commands.json for language servers
+
+find_package(fmt CONFIG REQUIRED)
+
+if (NOT MSVC)
+    set(TARGET_OPTIONS
+        "-Wall"
+        "-Wextra"
+        "-Wconversion"
+        "-Wpedantic"
+        "-Wshadow"
+        "-Werror"
+    )
+else()
+    string(JOIN " " TARGET_DEFINTIONS
+        ${TARGET_DEFINTIONS}
+        "_WIN32_WINNT=0x0A00"
+    )
+    set(TARGET_OPTIONS
+        "/W4"
+        "/WX"
+    )
+endif()
+
+# source files and includes
+set(TARGET_NAME helloalloc)
+set(TARGET_SOURCE_FILES
+    "helloalloc.cpp"
+)
+add_executable(${TARGET_NAME} ${TARGET_SOURCE_FILES})
+target_include_directories(${TARGET_NAME} PRIVATE "${PROJECT_SOURCE_DIR}")
+# target_compile_definitions(${TARGET_NAME} PRIVATE ${TARGET_DEFINTIONS})
+target_compile_features(${TARGET_NAME} PRIVATE cxx_std_20)
+target_link_libraries(${TARGET_NAME} PUBLIC fmt::fmt-header-only)
+source_group(TREE "${CMAKE_CURRENT_LIST_DIR}" FILES ${TARGET_SOURCE_FILES})
+
diff --git a/helloalloc.cpp b/helloalloc.cpp
new file mode 100644
index 0000000..964b6b4
--- /dev/null
+++ b/helloalloc.cpp
@@ -0,0 +1,71 @@
+#include <set>
+#include "fmt/format.h"
+
+namespace sky {
+constexpr std::size_t address_size = 3;
+constexpr std::size_t payload_size = 15;
+using address_t = uint8_t[address_size];
+using payload_t = uint8_t[payload_size];
+
+auto mcp_u32_to_address(address_t& dest, std::uint32_t const& addr) -> void {
+    dest[0] = static_cast<std::uint8_t>((addr & 0x000000FF) >>  0);
+    dest[1] = static_cast<std::uint8_t>((addr & 0x0000FF00) >>  8);
+    dest[2] = static_cast<std::uint8_t>((addr & 0x00FF0000) >> 16);
+}
+}
+
+template <typename T, std::size_t N>
+class FixedSizeAllocator {
+public:
+    using value_type   = T;
+    using pointer_type = T*;
+    using size_type    = std::size_t;
+
+    FixedSizeAllocator() : m_used_size(0) {}
+
+    auto operator()(const T& lhs, const T& rhs) const -> bool {
+        return lhs < rhs;
+    }
+
+    auto allocate(size_type n) -> pointer_type {
+        if (m_used_size + n > N) throw std::bad_alloc();
+
+        T* result = std::reinterpret_pointer_cast<value_type>(&m_pool[m_used_size]);
+        m_used_size += n;
+        return result;
+    }
+
+    auto deallocate(pointer_type ptr, size_type n) -> void {
+        if (ptr != &m_pool[m_used_size - n])
+            throw std::logic_error("Deallocating out of order");
+        m_used_size -= n;
+    }
+
+private:
+    std::uint8_t m_pool[N]{};
+    std::size_t  m_used_size;
+};
+
+auto main() -> int {
+    std::set<std::uint32_t, FixedSizeAllocator<std::uint32_t , 1024>> hello{};
+
+    std::uint32_t addr1_u32 = 32;
+    std::uint32_t addr2_u32 = 64;
+    std::uint32_t addr3_u32 = 128;
+    std::uint32_t addr4_u32 = 256;
+
+    hello.insert(addr1_u32);
+    hello.insert(addr2_u32);
+    hello.insert(addr3_u32);
+    hello.insert(addr4_u32);
+    hello.insert(addr1_u32);
+    hello.insert(addr1_u32);
+
+    for (auto const& addr : hello) {
+        sky::address_t buffer;
+        sky::mcp_u32_to_address(buffer, addr);
+        fmt::print("{:#04x}:{:#04x}:{:#04x}\n", buffer[2], buffer[1], buffer[0]);
+    }
+
+    return 0;
+}