A thread-safe, in-memory TCP database - written in Go

Description:

A custom, Redis-style key-value data store built from scratch over raw TCP sockets. Developed as part of my initiative to learn Go by building projects I find interesting, transitioning from writing client-side scripts to building persistent backend servers.

Features:

• Accepts raw TCP connections so users can interact with the database via terminal tools like netcat or telnet.
• Supports a custom command protocol: SET, GET, DEL, and SAVE.
• 100% thread-safe: Uses read/write mutexes so multiple concurrent users can query or modify the database at the exact same time without crashing the server.
• Persistent state: Can dump the entire in-memory map to a local text file and automatically restore it when the server reboots.

Usage:

1. Compile binary: go build -o mini-db

2. Run the database server: ./mini-db

3. Open a second terminal window and connect to the server using netcat: nc localhost 9000

4. You can now issue commands directly to the database:

> Welcome to Andrew's in-memory DB!
> SET language Go
> Value set!
> GET language
> Go
> DEL language
> language Sucesfully deleted!
> GET language
> Key does not exist in DB!
> SET username Admin
> Value set!
> SAVE
> Database dumped in dump.txt succesfully!

What I learned:

• Raw TCP Networking - using the net package to handle long-lived connection lifecycles instead of simple HTTP requests.
• Mutexes & Thread Safety - using sync.RWMutex to lock and unlock memory safely so concurrent goroutines don't cause panic errors.
• Custom Protocol Parsing - reading raw streams of text, cleaning up cross-platform invisible characters (\r\n), and executing logic based on the input.
• File I/O - reading from and writing to disk to persist state across server restarts.

Future Improvements:

Add a SETEX command to implement TTL (Time-To-Live) so keys automatically delete themselves after a certain amount of time. Also, maybe add some basic password authentication so anyone on my local network can't just connect and DEL my entire database!