Allow to turn off Utf8FrameValidator creation for websocket with Bina… (#9417)

…ryWebSocketFrames

Motivation:

`Utf8FrameValidator` is always created and added to the pipeline in `WebSocketServerProtocolHandler.handlerAdded` method. However, for websocket connection with only `BinaryWebSocketFrame`'s UTF8 validator is unnecessary overhead. Adding of `Utf8FrameValidator` could be easily avoided by extending of `WebSocketDecoderConfig` with additional property.

Specification requires UTF-8 validation only for `TextWebSocketFrame`.

Modification:

Added `boolean WebSocketDecoderConfig.withUTF8Validator` that allows to avoid adding of `Utf8FrameValidator` during pipeline initialization.

Result:

Less overhead when using only `BinaryWebSocketFrame`within web socket.

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketDecoderConfig.java

@@ -27,6 +27,7 @@ public final class WebSocketDecoderConfig {
     private final boolean allowMaskMismatch;
     private final boolean allowExtensions;
     private final boolean closeOnProtocolViolation;
+    private final boolean withUTF8Validator;
 
     /**
      * Constructor
@@ -44,14 +45,20 @@ public final class WebSocketDecoderConfig {
      *            Flag to allow reserved extension bits to be used or not
      * @param closeOnProtocolViolation
      *            Flag to send close frame immediately on any protocol violation.ion.
+     * @param withUTF8Validator
+     *            Allows you to avoid adding of Utf8FrameValidator to the pipeline on the
+     *            WebSocketServerProtocolHandler creation. This is useful (less overhead)
+     *            when you use only BinaryWebSocketFrame within your web socket connection.
      */
     private WebSocketDecoderConfig(int maxFramePayloadLength, boolean expectMaskedFrames, boolean allowMaskMismatch,
-                                  boolean allowExtensions, boolean closeOnProtocolViolation) {
+                                  boolean allowExtensions, boolean closeOnProtocolViolation,
+                                  boolean withUTF8Validator) {
         this.maxFramePayloadLength = maxFramePayloadLength;
         this.expectMaskedFrames = expectMaskedFrames;
         this.allowMaskMismatch = allowMaskMismatch;
         this.allowExtensions = allowExtensions;
         this.closeOnProtocolViolation = closeOnProtocolViolation;
+        this.withUTF8Validator = withUTF8Validator;
     }
 
     public int maxFramePayloadLength() {
@@ -74,6 +81,10 @@ public final class WebSocketDecoderConfig {
         return closeOnProtocolViolation;
     }
 
+    public boolean withUTF8Validator() {
+        return withUTF8Validator;
+    }
+
     @Override
     public String toString() {
         return "WebSocketDecoderConfig" +
@@ -82,6 +93,7 @@ public final class WebSocketDecoderConfig {
             ", allowMaskMismatch=" + allowMaskMismatch +
             ", allowExtensions=" + allowExtensions +
             ", closeOnProtocolViolation=" + closeOnProtocolViolation +
+            ", withUTF8Validator=" + withUTF8Validator +
             "]";
     }
 
@@ -99,6 +111,7 @@ public final class WebSocketDecoderConfig {
         private boolean allowMaskMismatch;
         private boolean allowExtensions;
         private boolean closeOnProtocolViolation = true;
+        private boolean withUTF8Validator = true;
 
         private Builder() {
             /* No-op */
@@ -111,6 +124,7 @@ public final class WebSocketDecoderConfig {
             allowMaskMismatch = decoderConfig.allowMaskMismatch();
             allowExtensions = decoderConfig.allowExtensions();
             closeOnProtocolViolation = decoderConfig.closeOnProtocolViolation();
+            withUTF8Validator = decoderConfig.withUTF8Validator();
         }
 
         public Builder maxFramePayloadLength(int maxFramePayloadLength) {
@@ -138,10 +152,15 @@ public final class WebSocketDecoderConfig {
             return this;
         }
 
+        public Builder withUTF8Validator(boolean withUTF8Validator) {
+            this.withUTF8Validator = withUTF8Validator;
+            return this;
+        }
+
         public WebSocketDecoderConfig build() {
             return new WebSocketDecoderConfig(
                     maxFramePayloadLength, expectMaskedFrames, allowMaskMismatch,
-                allowExtensions, closeOnProtocolViolation);
+                    allowExtensions, closeOnProtocolViolation, withUTF8Validator);
         }
     }
 }

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketServerProtocolHandler.java

@@ -216,7 +216,7 @@ public class WebSocketServerProtocolHandler extends WebSocketProtocolHandler {
                     new WebSocketServerProtocolHandshakeHandler(
                         websocketPath, subprotocols, checkStartsWith, handshakeTimeoutMillis, decoderConfig));
         }
-        if (cp.get(Utf8FrameValidator.class) == null) {
+        if (decoderConfig.withUTF8Validator() && cp.get(Utf8FrameValidator.class) == null) {
             // Add the UFT8 checking before this one.
             cp.addBefore(ctx.name(), Utf8FrameValidator.class.getName(),
                     new Utf8FrameValidator());

codec-http/src/test/java/io/netty/handler/codec/http/websocketx/WebSocketServerProtocolHandlerTest.java

@@ -120,6 +120,46 @@ public class WebSocketServerProtocolHandlerTest {
         assertFalse(ch.finish());
     }
 
+    @Test
+    public void testCreateUTF8Validator() {
+        WebSocketDecoderConfig config = WebSocketDecoderConfig.newBuilder()
+                .withUTF8Validator(true)
+                .build();
+
+        EmbeddedChannel ch = new EmbeddedChannel(
+                new WebSocketServerProtocolHandler("/test", null, false, false, 1000L, config),
+                new HttpRequestDecoder(),
+                new HttpResponseEncoder(),
+                new MockOutboundHandler());
+        writeUpgradeRequest(ch);
+
+        FullHttpResponse response = responses.remove();
+        assertEquals(SWITCHING_PROTOCOLS, response.status());
+        response.release();
+
+        assertNotNull(ch.pipeline().get(Utf8FrameValidator.class));
+    }
+
+    @Test
+    public void testDoNotCreateUTF8Validator() {
+        WebSocketDecoderConfig config = WebSocketDecoderConfig.newBuilder()
+                .withUTF8Validator(false)
+                .build();
+
+        EmbeddedChannel ch = new EmbeddedChannel(
+                new WebSocketServerProtocolHandler("/test", null, false, false, 1000L, config),
+                new HttpRequestDecoder(),
+                new HttpResponseEncoder(),
+                new MockOutboundHandler());
+        writeUpgradeRequest(ch);
+
+        FullHttpResponse response = responses.remove();
+        assertEquals(SWITCHING_PROTOCOLS, response.status());
+        response.release();
+
+        assertNull(ch.pipeline().get(Utf8FrameValidator.class));
+    }
+
     @Test
     public void testHandleTextFrame() {
         CustomTextFrameHandler customTextFrameHandler = new CustomTextFrameHandler();