✅ TodoAPP – Minimalistic C++20 HTTP Todo Service

---

📌 Project Summary

This is a minimalistic but highly extensible HTTP-based Todo management server written in modern C++20, emphasizing simplicity, testability, and performance.

It follows a practical Hexagonal Architecture without relying on verbose virtual interface hierarchies — making it ideal for both education and small-scale system design.

---

📄 Third-Party Components

This project uses the following external dependencies:

• Boost – Boost 1.88 (json, system, asio, beast)
• jh-toolkit – POD types and memory-safe wrappers (Apache 2.0)

All are statically linked, and no runtime dependencies are required.

---

✨ Features

• ✅ RESTful API with more than 10 routes
• ✅ Dual-indexed in-memory repository (name & timestamp)
• ✅ CSV import/export (bulk insertion & backup)
• ✅ Modern build system with CMake + Ninja + Clang + libc++
• ✅ Docker multi-arch support (amd64/arm64)

---

🚀 How to Build and Run

🛠 Native (macOS/Linux)

mkdir -p build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build .
./TodoAPP

✅ Clang + libc++ only tested (fully supported on macOS and most Linux distributions) ⚠️ GCC is not tested, and may fail due to header lookup or ABI quirks ❌ Windows is unsupported due to POSIX usage (sigaction, timegm, etc.)

---

🐳 Docker (Multi-Arch)

docker buildx build --platform linux/amd64 -t todo-app:amd64 --load .
docker run -p 8080:8080 todo-app:amd64

See build.md for complete Dockerfile and buildx instructions.

---

🔁 API Usage

See urls.md for full list of routes and example curl usage.

---

🧱 Architecture Highlights

✅ Minimal HTTP Layer

• Custom router built over Boost.Beast
• Routes self-register via REGISTER_VIEW(...) macros
• Handlers are regular C++ functions — readable and testable

✅ Practical Hexagonal Design

• No virtual interfaces or DI frameworks
• Application logic is separate from I/O (e.g., CSV / HTTP / persistence)
• Can be extended to SQLite or external databases easily

✅ Fast Lookup: POD Key + Dual Index

• jh::pod::array<char, 64> used as hashmap key — stack-allocated, transparent lookup

• Memory-local and avoids dynamic allocation like std::string

• Dual index:

  • by_name_: O(1) lookup by name
  • by_time_: log(N) range-scan by timestamp

---

🔚 Graceful Shutdown

To shut down the server:

curl -X POST http://localhost:8080/shutdown_server

⚠️ Do not force-close (docker stop) — the server handles cleanup only via this route.

---

💡 Notes

• 📄 API: urls.md
• 🛠 Build: build.md
• 🧠 Design overview: design.md