deepj · April 15, 2020 18:50 · Apr 15, 2020
diff --git a/nats-client.rb b/nats-client.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require 'async/io'
+require 'async/io/stream'
+require 'async/pool/controller'
+require 'async/await'
+
+module Async
+  module NATS
+    def self.local_endpoint
+      Async::IO::Endpoint.tcp('localhost', 4222)
+    end
+
+    class Client
+      include Async::Await
+
+      def initialize(endpoint = NATS.local_endpoint, **options)
+        @endpoint = endpoint
+
+        @pool = connect(**options)
+      end
+
+      def ping
+        call("PING")
+      end
+
+      def call(*arguments)
+        @pool.acquire do |connection|
+          connection.write_lines(arguments)
+          connection.flush
+          return connection.read_response
+        end
+      end
+
+      private
+
+      def connect(**options)
+        Async::Pool::Controller.wrap(**options) do
+          peer = @endpoint.connect
+          peer.setsockopt(Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1)
+
+          stream = IO::Stream.new(peer)
+          @protocol = Async::IO::Protocol::Line.new(stream, CLRF)
+        end
+      end
+    end
+  end
+end
+
+