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#![allow(unused_imports)]
use std::{
collections::HashMap,
io::{Read, Write},
net::{TcpListener, TcpStream},
sync::{Arc, Mutex},
thread,
time::{Duration, SystemTime, UNIX_EPOCH},
};
#[macro_use]
mod macros;
mod resp_commands;
mod resp_parser;
use resp_commands::RedisCommands;
use resp_parser::{parse, RespType};
#[derive(Debug, Clone)]
pub struct CacheEntry {
pub value: String,
pub expires_at: Option<u64>, // Unix timestamp in milliseconds
}
impl CacheEntry {
pub fn is_expired(&self) -> bool {
if let Some(expiry) = self.expires_at {
let now = SystemTime::now()
.duration_since(UNIX_EPOCH)
.unwrap()
.as_millis() as u64;
now > expiry
} else {
false
}
}
}
pub type SharedCache = Arc<Mutex<HashMap<String, CacheEntry>>>;
fn spawn_cleanup_thread(cache: SharedCache) {
let cache_clone = cache.clone();
std::thread::spawn(move || {
loop {
std::thread::sleep(Duration::from_secs(10)); // Check every 10 seconds
let mut cache = cache_clone.lock().unwrap();
let now = SystemTime::now()
.duration_since(UNIX_EPOCH)
.unwrap()
.as_millis() as u64;
// Remove expired keys
cache.retain(|_, entry| entry.expires_at.map_or(true, |expiry| now <= expiry));
}
});
}
fn handle_client(mut stream: TcpStream, cache: SharedCache) {
let mut buffer = [0; 512];
loop {
let _ = match stream.read(&mut buffer) {
Ok(0) => return, // connection closed
Ok(n) => n,
Err(_) => return, // error occurred
};
let parsed_resp = parse(&buffer).unwrap();
let response = RedisCommands::from(parsed_resp.0).execute(cache.clone());
// write respose back to the client
stream.write(&response).unwrap();
}
}
fn main() -> std::io::Result<()> {
let listener = TcpListener::bind("127.0.0.1:6379").unwrap();
let cache: SharedCache = Arc::new(Mutex::new(HashMap::new()));
spawn_cleanup_thread(cache.clone());
for stream in listener.incoming() {
match stream {
Ok(stream) => {
let cache_clone = cache.clone();
thread::spawn(|| {
handle_client(stream, cache_clone);
});
}
Err(e) => {
eprintln!("Connection failed: {}", e);
}
}
}
Ok(())
}
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