Implement a shared state between tasks

Cargo.toml

@@ -19,6 +19,7 @@ path = "Source/Server.rs"
 [dependencies]
 tokio = { version = "1.0.2", features = ["full"] }
 mini-redis = "0.4"
+bytes = "1.0.1"
 
 [[example]]
 name="Hello"

Examples/Hello.rs

@@ -1,3 +1,5 @@
+#![allow(non_snake_case)]
+
 use mini_redis::{client, Result};
 
 #[tokio::main]

Source/Client.rs

@@ -1 +1,3 @@
+#![allow(non_snake_case)]
+
 fn main() {}

Source/Server.rs

@@ -1,29 +1,41 @@
+#![allow(non_snake_case)]
+
+use bytes::Bytes;
 use mini_redis::{Connection, Frame};
+use std::collections::HashMap;
+use std::sync::{Arc, Mutex};
 use tokio::net::{TcpListener, TcpStream};
 
+type DataBase = Arc<Mutex<HashMap<String, Bytes>>>;
+
 #[tokio::main]
 async fn main() {
     // Bind the listener to the address
     let listener = TcpListener::bind("127.0.0.1:6379").await.unwrap();
 
+    println!("Listen {}", 6379);
+
+    let db = Arc::new(Mutex::new(HashMap::new()));
+
     loop {
         // The second item contains the IP and port of the new connection.
         let (socket, _) = listener.accept().await.unwrap();
 
+        // Clone the handle to the hash map.
+        let db = db.clone();
+
+        println!("Fetched");
+
         // A new task is spawned for each inbound socket. The socket is
         // moved to the new task and processed there.
         tokio::spawn(async move {
-            process(socket).await;
+            process(socket, db).await;
         });
     }
 }
 
-async fn process(socket: TcpStream) {
+async fn process(socket: TcpStream, db: DataBase) {
     use mini_redis::Command::{self, Get, Set};
-    use std::collections::HashMap;
-
-    // A hashmap is used to store data
-    let mut db = HashMap::new();
 
     // Connection, provided by `mini-redis`, handles parsing frames from
     // the socket
@@ -33,16 +45,14 @@ async fn process(socket: TcpStream) {
     while let Some(frame) = connection.read_frame().await.unwrap() {
         let response = match Command::from_frame(frame).unwrap() {
             Set(cmd) => {
-                // The value is stored as `Vec<u8>`
-                db.insert(cmd.key().to_string(), cmd.value().to_vec());
+                let mut db = db.lock().unwrap();
+                db.insert(cmd.key().to_string(), cmd.value().clone());
                 Frame::Simple("OK".to_string())
             }
             Get(cmd) => {
+                let db = db.lock().unwrap();
                 if let Some(value) = db.get(cmd.key()) {
-                    // `Frame::Bulk` expects data to be of type `Bytes`. This
-                    // type will be covered later in the tutorial. For now,
-                    // `&Vec<u8>` is converted to `Bytes` using `into()`.
-                    Frame::Bulk(value.clone().into())
+                    Frame::Bulk(value.clone())
                 } else {
                     Frame::Null
                 }