Add transport-level logging

[#201]

Author: mp911de

CHANGELOG

@@ -3,6 +3,8 @@ R2DBC PostgreSQL Changelog
 
 0.8.0.RELEASE
 -----------------------------------------
+* Add query logger #201
+* Drop SLF4J in favor of Reactor's Logger utilities #200
 * Fix instant handling #196
 * Add an auth-config for local connections in testing #195
 * Invalid listen example in README #192

README.md

@@ -369,8 +369,11 @@ If SL4J is on the classpath, it will be used. Otherwise, there are two possible
 
 Logging facilities:
 
-* Driver Logging: `io.r2dbc.postgresql`.                                                                                                                                                                                            
-* Query Logging: `io.r2dbc.postgresql.QUERY` on `DEBUG` level.                                                                                                                                                                                            
+* Driver Logging (`io.r2dbc.postgresql`)
+* Query Logging (`io.r2dbc.postgresql.QUERY` on `DEBUG` level)
+* Transport Logging (`io.r2dbc.postgresql.client`)
+    * `DEBUG` enables `Message` exchange logging
+    * `TRACE` enables traffic logging
 
 ## License
 This project is released under version 2.0 of the [Apache License][l].

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

@@ -21,12 +21,17 @@
 import io.netty.channel.ChannelDuplexHandler;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelOption;
+import io.netty.channel.ChannelPipeline;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.ServerChannel;
 import io.netty.channel.epoll.Epoll;
 import io.netty.channel.socket.DatagramChannel;
 import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
+import io.netty.handler.logging.LogLevel;
+import io.netty.handler.logging.LoggingHandler;
 import io.netty.util.ReferenceCountUtil;
+import io.netty.util.internal.logging.InternalLogger;
+import io.netty.util.internal.logging.InternalLoggerFactory;
 import io.r2dbc.postgresql.message.backend.BackendKeyData;
 import io.r2dbc.postgresql.message.backend.BackendMessage;
 import io.r2dbc.postgresql.message.backend.BackendMessageDecoder;
@@ -303,7 +308,18 @@ public static Mono<ReactorNettyClient> connect(ConnectionProvider connectionProv
             tcpClient = tcpClient.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, Math.toIntExact(connectTimeout.toMillis()));
         }
 
-        return tcpClient.connect().flatMap(it -> registerSslHandler(sslConfig, it).thenReturn(new ReactorNettyClient(it)));
+        return tcpClient.connect().flatMap(it -> {
+
+            ChannelPipeline pipeline = it.channel().pipeline();
+
+            InternalLogger logger = InternalLoggerFactory.getInstance(ReactorNettyClient.class);
+            if (logger.isTraceEnabled()) {
+                pipeline.addFirst(LoggingHandler.class.getSimpleName(),
+                    new LoggingHandler(ReactorNettyClient.class, LogLevel.TRACE));
+            }
+
+            return registerSslHandler(sslConfig, it).thenReturn(new ReactorNettyClient(it));
+        });
     }
 
     private static Mono<? extends Void> registerSslHandler(SSLConfig sslConfig, Connection it) {

src/test/java/io/r2dbc/postgresql/client/ExtendedQueryMessageFlowTest.java

@@ -97,7 +97,7 @@ void executeNoPortalNameSupplier() {
     @Test
     void executeNoStatement() {
         assertThatIllegalArgumentException().isThrownBy(() -> ExtendedQueryMessageFlow.execute(Flux.empty(), NO_OP, () -> "", null, "", false))
-            .withMessage("statement must not be null");
+            .withMessage("statementName must not be null");
     }
 
     @Test