From 7c6189234481cc6be1e6495427f0c9931167812f Mon Sep 17 00:00:00 2001
From: harsh_jain <harshjniitr@gmail.com>
Date: Thu, 11 Oct 2018 16:19:50 +0530
Subject: [PATCH] socket chat in rust

---
 .gitignore       |  1 +
 rust/Cargo.lock  | 14 ++++++++
 rust/Cargo.toml  |  7 ++++
 rust/README.md   | 27 ++++++++++++++++
 rust/src/main.rs | 83 ++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 132 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 rust/Cargo.lock
 create mode 100644 rust/Cargo.toml
 create mode 100644 rust/README.md
 create mode 100644 rust/src/main.rs

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..2a54eab
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+rust/target
diff --git a/rust/Cargo.lock b/rust/Cargo.lock
new file mode 100644
index 0000000..f370060
--- /dev/null
+++ b/rust/Cargo.lock
@@ -0,0 +1,14 @@
+[[package]]
+name = "bufstream"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "socket-server-test"
+version = "0.1.0"
+dependencies = [
+ "bufstream 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[metadata]
+"checksum bufstream 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f2f382711e76b9de6c744cc00d0497baba02fb00a787f088c879f01d09468e32"
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
new file mode 100644
index 0000000..6379dbf
--- /dev/null
+++ b/rust/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "socket-server-test"
+version = "0.1.0"
+authors = ["Clemens Wallrath <dev@nervengiftlabs.de>"]
+
+[dependencies]
+bufstream = "0.1"
diff --git a/rust/README.md b/rust/README.md
new file mode 100644
index 0000000..ce08d29
--- /dev/null
+++ b/rust/README.md
@@ -0,0 +1,27 @@
+# Socket Chat Server in Rust
+
+## Prerequisite
+```
+curl -sSf https://static.rust-lang.org/rustup.sh | sh
+```
+Cargo installation # package manager for rust # https://doc.rust-lang.org/cargo/getting-started/installation.html
+
+## Run
+
+Start server --
+```
+cargo run
+```
+
+Server is running at port 8888.
+
+Connect Client, using swissy-army knife --
+```
+nc localhost 8888
+```
+
+
+## References
+
+- https://nbaksalyar.github.io/2015/07/10/writing-chat-in-rust.html
+- https://gist.github.com/andelf/8668088
diff --git a/rust/src/main.rs b/rust/src/main.rs
new file mode 100644
index 0000000..4617434
--- /dev/null
+++ b/rust/src/main.rs
@@ -0,0 +1,83 @@
+extern crate bufstream;
+
+use std::str::FromStr;
+use std::io::Write;
+use std::net::{TcpListener, TcpStream};
+use std::net::SocketAddr;
+use std::thread::spawn;
+use bufstream::BufStream;
+use std::io::BufRead;
+use std::sync::{Arc,RwLock};
+use std::sync::mpsc;
+use std::sync::mpsc::{Sender, Receiver};
+
+fn handle_connection(stream: &mut BufStream<TcpStream>, chan: Sender<String>, arc: Arc<RwLock<Vec<String>>>) {
+    stream.write(b"Welcome to Simple Chat Server!\n").unwrap();
+    stream.write(b"Plz input yourname: ").unwrap();
+    stream.flush().unwrap();
+    let mut name = String::new();
+    stream.read_line(&mut name).unwrap();
+    let name = name.trim_right();
+    stream.write_fmt(format_args!("Hello, {}!\n", name)).unwrap();
+    stream.flush().unwrap();
+
+    let mut pos = 0;
+    loop {
+        {
+            let lines = arc.read().unwrap();
+            println!("DEBUG arc.read() => {:?}", lines);
+            for i in pos..lines.len() {
+                stream.write_fmt(format_args!("{}", lines[i])).unwrap();
+                pos = lines.len();
+            };
+        }
+        stream.write(b" > ").unwrap();
+        stream.flush().unwrap();
+
+        let mut reads = String::new();
+        stream.read_line(&mut reads).unwrap(); //TODO: non-blocking read
+        if reads.trim().len() != 0 {
+            println!("DEBUG: reads len =>>>>> {}", reads.len());
+            chan.send(format!("[{}] said: {}", name, reads)).unwrap();
+            println!("DEBUG: got '{}' from {}", reads.trim(), name);
+        }
+    }
+}
+
+fn main() {
+    let addr: SocketAddr = SocketAddr::from_str("127.0.0.1:8888").unwrap();
+    let listener = TcpListener::bind(addr).unwrap();
+
+    let (send, recv): (Sender<String>, Receiver<String>) = mpsc::channel();
+    let arc: Arc<RwLock<Vec<String>>> = Arc::new(RwLock::new(Vec::new()));
+
+    let arc_w = arc.clone();
+
+    spawn(move|| {
+        loop {
+            let msg = recv.recv().unwrap();
+            print!("DEBUG: msg {}", msg);
+            {
+                let mut arc_w = arc_w.write().unwrap();
+                arc_w.push(msg);
+            } // write lock is released at the end of this scope
+        }
+    });
+
+    for stream in listener.incoming() {
+        match stream {
+            Err(_) => println!("listen error"),
+            Ok(mut stream) => {
+                println!("connection from {} to {}",
+                         stream.peer_addr().unwrap(),
+                         stream.local_addr().unwrap());
+                let send = send.clone();
+                let arc = arc.clone();
+                spawn(move|| {
+                    let mut stream = BufStream::new(stream);
+                    handle_connection(&mut stream, send, arc);
+                });
+            }
+        }
+    }
+}