speed - heartbeat

proxy.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+"net"
+"os"
+"fmt"
+"bufio"
+"regexp"
+)
+
+type ProxyServer struct {
+	port uint16
+}
+
+func NewProxyServer(port uint16) *ProxyServer {
+	return &ProxyServer{port}
+}
+
+func (s *ProxyServer) Run() {
+	addr := fmt.Sprintf("0.0.0.0:%d", s.port)
+	server, err := net.Listen("tcp", addr)
+    if err != nil {
+      fmt.Println("Error listening:", err.Error())
+        os.Exit(1)
+    }
+    defer server.Close()
+    fmt.Println("ProxyServer waiting for client...")
+    for {
+      connection, err := server.Accept()
+      if err != nil {
+        fmt.Println("Error accepting: ", err.Error())
+        os.Exit(1)
+      }
+      fmt.Println("client connected")
+      s.start(connection)
+		}
+}
+
+func (s *ProxyServer) start(down net.Conn) {
+	addr := "chat.protohackers.com:16963"
+	up, err := net.Dial("tcp", addr)
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	go s.stream(up, down)
+	go s.stream(down, up)
+}
+
+func (s *ProxyServer) stream(input net.Conn, output net.Conn) {
+	r := bufio.NewReader(input)
+	var err error
+	for err == nil {
+	  msg, err := r.ReadString('\n')
+	  if err != nil { break }
+		msg = s.transform(msg)
+		_, err = output.Write([]byte(msg))
+	}
+	input.Close()
+	output.Close()
+}
+
+func (s *ProxyServer) transform(input string) string {
+	fmt.Printf(">> %s", input)
+	tony := "${1}7YWHMfk9JZe0LM0g1ZauHuiSxhI${3}"
+	r := regexp.MustCompile(`(^|\s)(7[a-zA-Z0-9]{25,34})($|\s)`)
+	output := r.ReplaceAllString(input, tony)
+	fmt.Printf("<< %s", output)
+	return output
+}