Generate log messages in advance

reactor-netty-core/src/main/java/reactor/netty/resources/PooledConnectionProvider.java

@@ -55,6 +55,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.StringJoiner;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.TimeUnit;
@@ -364,17 +365,31 @@ protected static void logPoolState(Channel channel, InstrumentedPool<? extends C
 	}
 
 	protected static void logPoolState(Channel channel, InstrumentedPool<? extends Connection> pool, String msg, @Nullable Throwable t) {
-		InstrumentedPool.PoolMetrics metrics = pool.metrics();
+		String logMsg = msg + ", " + stringifyPoolMetrics(pool);
+		if (t == null) {
+			log.debug(format(channel, logMsg));
+			return;
+		}
+
 		log.debug(
-				format(channel, "{}, now: {} active connections, {} inactive connections and {} pending acquire requests."),
-				msg,
-				metrics.acquiredSize(),
-				metrics.idleSize(),
-				metrics.pendingAcquireSize(),
+				format(channel, logMsg),
 				t
 		);
 	}
 
+	private static String stringifyPoolMetrics(InstrumentedPool<? extends Connection> pool) {
+		InstrumentedPool.PoolMetrics metrics = pool.metrics();
+		return new StringJoiner(" ")
+				.add("now:")
+				.add(String.valueOf(metrics.acquiredSize()))
+				.add("active connections,")
+				.add(String.valueOf(metrics.idleSize()))
+				.add("inactive connections")
+				.add(String.valueOf(metrics.pendingAcquireSize()))
+				.add("pending acquire requests.")
+				.toString();
+	}
+
 	final void scheduleInactivePoolsDisposal() {
 		if (!inactivePoolDisposeInterval.isZero()) {
 			Schedulers.parallel()