lj_rust/src/redis_ctrl.rs

use redis::{
    Client,
    Connection,
    Commands
};
use ron::de::from_str;

#[repr(u8)]
#[derive(Debug,PartialEq)]
pub enum Order {
    Draw = 0,
    Edh, //homography
    Black,
    Grid,
    Resampler,
    ClientKey,
    Intensity,
    Kpps,
    ColorBalance
}

impl TryFrom<u8> for Order {
    type Error = String;
    
    fn try_from(value: u8) -> Result<Self, Self::Error> {
	use Order::*;

	if value > 8 {
	    return Err("order out of range".to_string());
	}
	
	Ok(match value {
	    0 => Draw,
	    1 => Edh,
	    2 => Black,
	    3 => Grid,
	    4 => Resampler,
	    5 => ClientKey,
	    6 => Intensity,
	    7 => Kpps,
	    8 => ColorBalance,
	    _ => unreachable!()
	})
    }
}  

pub type Line = Vec<(f32,f32,u32)>;

pub struct RedisCtrl {
    pub client: Client,
    pub connection: Connection
}

impl RedisCtrl {

    pub fn new() -> Result<Self, Box<dyn std::error::Error>> {
	let client = Client::open("redis://127.0.0.1/")?;
	let connection = client.get_connection()?;
	Ok(RedisCtrl { client, connection })
    }

    pub fn get(
	&mut self,
	key: &str
    ) -> Result<Line, Box<dyn std::error::Error>> {
	let val : String = self.connection.get(key)?;
	let line : Line = from_str(&val)?;
	Ok(line)
    }
    
    pub fn get_order(
	&mut self,
	id: u8
    ) -> Result<Order, Box<dyn std::error::Error>> {
	let path = format!("/order/{id}");
	let val : u8 = self.connection.get(path.clone())?;
	
	if val == 1 || val >= 4 {
	    self.connection.set(path, 0)?;
	}
	
	Ok(val.try_into()?)
    }

}