From f9e30c194f58b2898499f43aa5625b506c9d3dd7 Mon Sep 17 00:00:00 2001
From: Greg Heartsfield <scsibug@imap.cc>
Date: Sat, 20 Nov 2021 20:59:40 -0600
Subject: [PATCH] Demo server (compiles)

---
 Cargo.lock  | 226 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml  |   4 +
 src/main.rs |  55 ++++++++++++-
 3 files changed, 283 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 47448b0..e47473e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,26 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e37cfd5e7657ada45f742d6e99ca5788580b5c529dc78faf11ece6dc702656f"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "atty"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9b39be18770d11421cdb1b9947a45dd3f37e93092cbf377614828a319d5fee8"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.0.1"
@@ -14,6 +34,12 @@ version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
 
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
 [[package]]
 name = "block-buffer"
 version = "0.9.0"
@@ -59,6 +85,19 @@ dependencies = [
  "generic-array",
 ]
 
+[[package]]
+name = "env_logger"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b2cf0344971ee6c64c31be0d530793fba457d322dfec2810c453d0ef228f9c3"
+dependencies = [
+ "atty",
+ "humantime",
+ "log",
+ "regex",
+ "termcolor",
+]
+
 [[package]]
 name = "fnv"
 version = "1.0.7"
@@ -81,6 +120,19 @@ version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "88d1c26957f23603395cd326b0ffe64124b818f4449552f960d815cfba83a53d"
 
+[[package]]
+name = "futures-macro"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18e4a4b95cea4b4ccbcf1c5675ca7c4ee4e9e75eb79944d07defde18068f79bb"
+dependencies = [
+ "autocfg",
+ "proc-macro-hack",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "futures-sink"
 version = "0.3.17"
@@ -101,10 +153,13 @@ checksum = "36568465210a3a6ee45e1f165136d68671471a501e632e9a98d96872222b5481"
 dependencies = [
  "autocfg",
  "futures-core",
+ "futures-macro",
  "futures-sink",
  "futures-task",
  "pin-project-lite",
  "pin-utils",
+ "proc-macro-hack",
+ "proc-macro-nested",
  "slab",
 ]
 
@@ -129,6 +184,15 @@ dependencies = [
  "wasi",
 ]
 
+[[package]]
+name = "hermit-abi"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "http"
 version = "0.2.5"
@@ -146,6 +210,12 @@ version = "1.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "acd94fdbe1d4ff688b67b04eee2e17bd50995534a61539e45adfefb45e5e5503"
 
+[[package]]
+name = "humantime"
+version = "2.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
+
 [[package]]
 name = "idna"
 version = "0.2.3"
@@ -157,6 +227,15 @@ dependencies = [
  "unicode-normalization",
 ]
 
+[[package]]
+name = "instant"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a5bbe824c507c5da5956355e86a746d82e0e1464f65d862cc5e71da70e94b2c"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "itoa"
 version = "0.4.8"
@@ -169,6 +248,15 @@ version = "0.2.108"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8521a1b57e76b1ec69af7599e75e38e7b7fad6610f037db8c79b127201b5d119"
 
+[[package]]
+name = "lock_api"
+version = "0.4.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "712a4d093c9976e24e7dbca41db895dabcbac38eb5f4045393d17a95bdfb1109"
+dependencies = [
+ "scopeguard",
+]
+
 [[package]]
 name = "log"
 version = "0.4.14"
@@ -216,6 +304,10 @@ dependencies = [
 name = "nostr-rs-relay"
 version = "0.1.0"
 dependencies = [
+ "env_logger",
+ "futures-util",
+ "log",
+ "tokio",
  "tokio-tungstenite",
 ]
 
@@ -228,12 +320,53 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "num_cpus"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05499f3756671c15885fee9034446956fff3f243d6077b91e5767df161f766b3"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "692fcb63b64b1758029e0a96ee63e049ce8c5948587f2f7208df04625e5f6b56"
+
 [[package]]
 name = "opaque-debug"
 version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
+[[package]]
+name = "parking_lot"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7d17b78036a60663b797adeaee46f5c9dfebb86948d1255007a1d6be0271ff99"
+dependencies = [
+ "instant",
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d76e8e1493bcac0d2766c42737f34458f1c8c50c0d23bcb24ea953affb273216"
+dependencies = [
+ "cfg-if",
+ "instant",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "winapi",
+]
+
 [[package]]
 name = "percent-encoding"
 version = "2.1.0"
@@ -258,6 +391,18 @@ version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed0cfbc8191465bed66e1718596ee0b0b35d5ee1f41c5df2189d0fe8bde535ba"
 
+[[package]]
+name = "proc-macro-hack"
+version = "0.5.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
+
+[[package]]
+name = "proc-macro-nested"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc881b2c22681370c6a780e47af9840ef841837bc98118431d4e1868bd0c1086"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.32"
@@ -316,6 +461,38 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "redox_syscall"
+version = "0.2.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8383f39639269cde97d255a32bdb68c047337295414940c68bdd30c2e13203ff"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "regex"
+version = "1.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
+
+[[package]]
+name = "scopeguard"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
+
 [[package]]
 name = "sha-1"
 version = "0.9.8"
@@ -329,12 +506,27 @@ dependencies = [
  "opaque-debug",
 ]
 
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e51e73328dc4ac0c7ccbda3a494dfa03df1de2f46018127f60c693f2648455b0"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "slab"
 version = "0.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9def91fd1e018fe007022791f865d0ccc9b3a0d5001e01aabb8b40e46000afb5"
 
+[[package]]
+name = "smallvec"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ecab6c735a6bb4139c0caafd0cc3635748bbb3acf4550e8138122099251f309"
+
 [[package]]
 name = "syn"
 version = "1.0.81"
@@ -346,6 +538,15 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "termcolor"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2dfed899f0eb03f32ee8c6a0aabdb8a7949659e3466561fc0adf54e26d88c5f4"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "thiserror"
 version = "1.0.30"
@@ -392,10 +593,26 @@ dependencies = [
  "libc",
  "memchr",
  "mio",
+ "num_cpus",
+ "once_cell",
+ "parking_lot",
  "pin-project-lite",
+ "signal-hook-registry",
+ "tokio-macros",
  "winapi",
 ]
 
+[[package]]
+name = "tokio-macros"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9efc1aba077437943f7515666aa2b882dfabfbfdf89c819ea75a8d6e9eaba5e"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "tokio-tungstenite"
 version = "0.16.0"
@@ -500,6 +717,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
diff --git a/Cargo.toml b/Cargo.toml
index 7fb658f..b53c3fb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,4 +6,8 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+log = "0.4.14"
+env_logger = "0.9.0"
+tokio = { version = "1.14.0", features = ["full"] }
+futures-util = "0.3.17"
 tokio-tungstenite = "0.16.0"
diff --git a/src/main.rs b/src/main.rs
index e7a11a9..77abb89 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,54 @@
-fn main() {
-    println!("Hello, world!");
+//! A simple echo server.
+//!
+//! You can test this out by running:
+//!
+//!     cargo run --example server 127.0.0.1:12345
+//!
+//! And then in another window run:
+//!
+//!     cargo run --example client ws://127.0.0.1:12345/
+
+use std::{env, io::Error};
+
+use futures_util::{future, StreamExt, TryStreamExt};
+use log::info;
+use tokio::net::{TcpListener, TcpStream};
+
+#[tokio::main]
+async fn main() -> Result<(), Error> {
+    let _ = env_logger::try_init();
+    let addr = env::args()
+        .nth(1)
+        .unwrap_or_else(|| "127.0.0.1:8080".to_string());
+
+    // Create the event loop and TCP listener we'll accept connections on.
+    let try_socket = TcpListener::bind(&addr).await;
+    let listener = try_socket.expect("Failed to bind");
+    info!("Listening on: {}", addr);
+
+    while let Ok((stream, _)) = listener.accept().await {
+        tokio::spawn(accept_connection(stream));
+    }
+
+    Ok(())
+}
+
+async fn accept_connection(stream: TcpStream) {
+    let addr = stream
+        .peer_addr()
+        .expect("connected streams should have a peer address");
+    info!("Peer address: {}", addr);
+
+    let ws_stream = tokio_tungstenite::accept_async(stream)
+        .await
+        .expect("Error during the websocket handshake occurred");
+
+    info!("New WebSocket connection: {}", addr);
+
+    let (write, read) = ws_stream.split();
+    // We should not forward messages other than text or binary.
+    read.try_filter(|msg| future::ready(msg.is_text() || msg.is_binary()))
+        .forward(write)
+        .await
+        .expect("Failed to forward messages")
 }