Http2FrameLogger avoid hex dump of the ByteBufs when log disabled

Gordiychuk · normanmaurer · commit fe8ecea36610 · 2017-07-26T21:21:04.000+02:00
Motivation: Currentry logger create hex dump even if log write will not apply. It's unecessary GC overhead. Modifications: Restore optimization from #3492 Result: Fixes #7025
diff --git a/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2FrameLogger.java b/codec-http2/src/main/java/io/netty/handler/codec/http2/Http2FrameLogger.java
@@ -20,6 +20,7 @@
 import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.handler.logging.LogLevel;
+import io.netty.util.internal.StringUtil;
 import io.netty.util.internal.UnstableApi;
 import io.netty.util.internal.logging.InternalLogLevel;
 import io.netty.util.internal.logging.InternalLogger;
@@ -132,6 +133,10 @@ public void logUnknownFrame(Direction direction, ChannelHandlerContext ctx, byte
     }
 
     private String toString(ByteBuf buf) {
+        if (!logger.isEnabled(level)) {
+            return StringUtil.EMPTY_STRING;
+        }
+
         if (level == InternalLogLevel.TRACE || buf.readableBytes() <= BUFFER_LENGTH_THRESHOLD) {
             // Log the entire buffer.
             return ByteBufUtil.hexDump(buf);
