A Redis-inspired key-value database, written in Rust.

In my journey of learning Rust I'm writing small and simple clones of existing products, and this is a simple key-value database.

At the time of writing (19/02/2023 in dd/mm/yy format) I am still new to Rust, and I do not claim that the code is optimal. There are probably lots of improvements to be made.

After running cargo build, preferably with the --release flag, the ssahindb binary (the engine) can be run directly. By default it'll listen on the port 50394, and the address can be specified with the -a/--address flag. If you run the binary executable with the --help flag, it will display a nice dialogue generated by Clap (the command line argument parser this project uses) and show you all the flags.
The flags are listed below, directly copied from the dialogue itself.

Usage: ssahindb [OPTIONS]

Options:
  -a, --address <ADDRESS>  [default: 0.0.0.0:50394]
  -m, --mode <MODE>        [default: m]
  -h, --help               Print help
  -V, --version            Print version

There are 3 modes for the engine, m/memory uses a hashmap to store values in memory, d/disk directly writes values to files named after their respective keys to a db directory in the working directory, and b/both does both. I might look into a more effective method for the disk mode.

After executing the engine executable, it begins to listen on the specified address.

Usage: ssahindb-cli [OPTIONS]

Options:
  -a, --address <ADDRESS>  [default: localhost:50394]
  -h, --help               Print help
  -V, --version            Print version

After executing the cli binary, the user is greeted with a prompt printing the currently connected address just like redis-cli. The user can type commands like set key1 val1 or get key1 or exists key1 and so on.
If the command or its arguments are invalid, the cli will display a warning such as "Invalid command g, with args [\"key1\", \"val1\"]!", and if the argument count is invalid, it'll display "Invalid number of args for command get, with args [\"key1\", \"val1\"]! There should be 1 argument(s)".

• Set: Sets a key's value
• Get: Retrieves a key's value
• Del: Deletes a key
• Exists: Returns true if the key exists, false otherwise

The libraries could be structured better or even as their own repos, maybe? No idea.

Libraries for

• Python
• Rust

are available for use, and their example uses are shown in libraries/langhere/example.langext, or below:

import ssahindb

con = ssahindb.connection("localhost:50394")

print(con.exists("key3"))

print(con.set("key3", "val3"))

print(con.exists("key3"))

print(con.get("key3"))

print(con.delete("key3"))

print(con.exists("key3"))

pub mod ssahindb;

fn main() {
    let client = ssahindb::Client::open("localhost:50394".to_string());
    let con = client.get_connection();

    println!("Key3 exists: {}", con.exists("key3".to_string()));
    con.set("key3".to_string(), "val3".to_string());

    println!("get key3: {}", con.get("key3".to_string()));
    con.del("key3".to_string());

    println!("Key3 exists: {}", con.exists("key3".to_string()));

    println!("get key3: {}", con.get("key3".to_string()));
}

None as far as I know.

No idea at the moment. Implementing other data types found in Redis like Lists, Sets etc. could be done but I currently don't aim to as I plan this project to be very simple.