Use lazy_static! to avoid expensive regex compiles in loop

Cargo.lock

@@ -224,6 +224,7 @@ name = "hexland-server"
 version = "0.1.0"
 dependencies = [
  "futures",
+ "lazy_static",
  "rand",
  "regex",
  "sha2",
@@ -264,6 +265,12 @@ version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c8af84674fe1f223a982c933a0ee1086ac4d4052aa0fb8060c12c6ad838e754"
 
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.133"

Cargo.toml

@@ -11,4 +11,5 @@ rand = "0.8.5"
 regex = "1.6.0"
 tokio = { version = "1.21.2", features = ["full"] }
 tokio-tungstenite = "0.17.2"
-futures = "0.3.24"
+futures = "0.3.24"
+lazy_static = "1.4.0"

src/message.rs

@@ -6,6 +6,7 @@ use tokio_tungstenite::{
     tungstenite::Message as WsMessage,
 };
 use futures::{StreamExt, SinkExt};
+use lazy_static::lazy_static;
 
 #[derive(PartialEq, Debug)]
 pub struct Message {
@@ -25,8 +26,10 @@ pub enum Error {
 
 impl Message {
     pub fn parse(text: String) -> Result<Message> {
-	let re = regex::Regex::new(r"^([A-Z_]+):\s*(.*)").unwrap();
-	match re.captures(text.as_str()) {
+        lazy_static! {
+            static ref RE: regex::Regex = regex::Regex::new(r"^([A-Z_]+):\s*(.*)").unwrap();
+        }
+	match RE.captures(text.as_str()) {
             Some(captures) => {
 		if captures.len() < 3 {
 		    Err(Error::BadParse)