Polishing.

Reuse connection-closed exception factory method.

[#492]

Signed-off-by: Mark Paluch <[email protected]>

Author: mp911de

src/main/java/io/r2dbc/postgresql/client/ReactorNettyClient.java

@@ -210,14 +210,22 @@ public Flux<BackendMessage> exchange(Predicate<BackendMessage> takeUntil, Publis
         Assert.requireNonNull(takeUntil, "takeUntil must not be null");
         Assert.requireNonNull(requests, "requests must not be null");
 
-        return this.messageSubscriber.addConversation(takeUntil, requests, it -> this.requestSink.emitNext(it, Sinks.EmitFailureHandler.FAIL_FAST), this::isConnected);
+        if (!isConnected()) {
+            return Flux.error(this.messageSubscriber.createClientClosedException());
+        }
+
+        return this.messageSubscriber.addConversation(takeUntil, requests, this::doSendRequest, this::isConnected);
     }
 
     @Override
     public void send(FrontendMessage message) {
         Assert.requireNonNull(message, "requests must not be null");
 
-        this.requestSink.emitNext(Mono.just(message), Sinks.EmitFailureHandler.FAIL_FAST);
+        doSendRequest(Mono.just(message));
+    }
+
+    private void doSendRequest(Publisher<FrontendMessage> it) {
+        this.requestSink.emitNext(it, Sinks.EmitFailureHandler.FAIL_FAST);
     }
 
     private Mono<Void> resumeError(Throwable throwable) {
@@ -676,7 +684,7 @@ public Flux<BackendMessage> addConversation(Predicate<BackendMessage> takeUntil,
                         sink.onRequest(value -> onRequest(conversation, value));
 
                         if (!isConnected.get()) {
-                            sink.error(new PostgresConnectionClosedException("Cannot exchange messages because the connection is closed"));
+                            sink.error(createClientClosedException());
                             return;
                         }
 
@@ -689,12 +697,15 @@ public Flux<BackendMessage> addConversation(Predicate<BackendMessage> takeUntil,
                         sender.accept(requestMessages);
                     } else {
                         sink.error(new RequestQueueException("Cannot exchange messages because the request queue limit is exceeded"));
-
                     }
                 }
             });
         }
 
+        PostgresConnectionClosedException createClientClosedException() {
+            return new PostgresConnectionClosedException("Cannot exchange messages because the connection is closed");
+        }
+
         /**
          * {@link Subscription#request(long)} callback. Request more for a {@link Conversation}. Potentially, demands also more upstream elements.
          *