Add failImmediatelyOnTooLongFrameOption.

src/main/java/org/jboss/netty/handler/codec/frame/DelimiterBasedFrameDecoder.java

@@ -69,6 +69,7 @@ public class DelimiterBasedFrameDecoder extends FrameDecoder {
     private final boolean stripDelimiter;
     private boolean discardingTooLongFrame;
     private int tooLongFrameLength;
+    private boolean failImmediatelyOnTooLongFrame = false;
 
     /**
      * Creates a new instance.
@@ -169,11 +170,11 @@ public class DelimiterBasedFrameDecoder extends FrameDecoder {
                 discardingTooLongFrame = false;
                 buffer.skipBytes(minFrameLength + minDelimLength);
 
-                // TODO Let user choose when the exception should be raised - early or late?
-                //      If early, fail() should be called when discardingTooLongFrame is set to true.
                 int tooLongFrameLength = this.tooLongFrameLength;
                 this.tooLongFrameLength = 0;
-                fail(ctx, tooLongFrameLength);
+                if (!failImmediatelyOnTooLongFrame) {
+                    fail(ctx, tooLongFrameLength);
+                }
                 return null;
             }
 
@@ -199,6 +200,9 @@ public class DelimiterBasedFrameDecoder extends FrameDecoder {
                     tooLongFrameLength = buffer.readableBytes();
                     buffer.skipBytes(buffer.readableBytes());
                     discardingTooLongFrame = true;
+                    if (failImmediatelyOnTooLongFrame) {
+                        fail(ctx, tooLongFrameLength);
+                    }
                 }
             } else {
                 // Still discarding the buffer since a delimiter is not found.
@@ -209,6 +213,23 @@ public class DelimiterBasedFrameDecoder extends FrameDecoder {
         }
     }
 
+    /**
+     * Set the behavior when a frame longer than maxFrameLength is encountered.
+     * 
+     * @param failImmediatelyOnTooLongFrame  If false (the default) a {@link TooLongFrameException}
+     *                                       is thrown if the length of the frame exceeds maxFrameLength,
+     *                                       after the delimiter has been read.
+     *                                       If true a {@link TooLongFrameException} is thrown immediately
+     *                                       when the length of the frame exceeds maxFrameLength,
+     *                                       regardless of whether a delimiter has been found yet.
+     */
+    public DelimiterBasedFrameDecoder setFailImmediatelyOnTooLongFrame(
+            boolean failImmediatelyOnTooLongFrame)
+    {
+      this.failImmediatelyOnTooLongFrame = failImmediatelyOnTooLongFrame;
+      return this;
+    }
+
     private void fail(ChannelHandlerContext ctx, long frameLength) {
         if (frameLength > 0) {
             Channels.fireExceptionCaught(

src/main/java/org/jboss/netty/handler/codec/frame/LengthFieldBasedFrameDecoder.java

@@ -198,6 +198,7 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
     private boolean discardingTooLongFrame;
     private long tooLongFrameLength;
     private long bytesToDiscard;
+    private boolean failImmediatelyOnTooLongFrame = false;
 
     /**
      * Creates a new instance.
@@ -290,7 +291,7 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
             buffer.skipBytes(localBytesToDiscard);
             bytesToDiscard -= localBytesToDiscard;
             this.bytesToDiscard = bytesToDiscard;
-            failIfNecessary(ctx);
+            failIfNecessary(ctx, false);
             return null;
         }
 
@@ -340,7 +341,7 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
             tooLongFrameLength = frameLength;
             bytesToDiscard = frameLength - buffer.readableBytes();
             buffer.skipBytes(buffer.readableBytes());
-            failIfNecessary(ctx);
+            failIfNecessary(ctx, true);
             return null;
         }
 
@@ -366,19 +367,25 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
         return frame;
     }
 
-    private void failIfNecessary(ChannelHandlerContext ctx) {
+    private void failIfNecessary(ChannelHandlerContext ctx, boolean firstDetectionOfTooLongFrame) {
         if (bytesToDiscard == 0) {
             // Reset to the initial state and tell the handlers that
             // the frame was too large.
-            // TODO Let user choose when the exception should be raised - early or late?
-            //      If early, fail() should be called when discardingTooLongFrame is set to true.
             long tooLongFrameLength = this.tooLongFrameLength;
             this.tooLongFrameLength = 0;
             discardingTooLongFrame = false;
-            fail(ctx, tooLongFrameLength);
+            if (!failImmediatelyOnTooLongFrame)
+            {
+                fail(ctx, tooLongFrameLength);
+            }
         } else {
             // Keep discarding.
         }
+
+        if (firstDetectionOfTooLongFrame && failImmediatelyOnTooLongFrame)
+        {
+            fail(ctx, tooLongFrameLength);
+        }
     }
 
     /**
@@ -402,6 +409,23 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
         return frame;
     }
 
+    /**
+     * Set the behavior when a frame longer than maxFrameLength is encountered.
+     * 
+     * @param failImmediatelyOnTooLongFrame  If false (the default) a {@link TooLongFrameException}
+     *                                       is thrown if the length of the frame exceeds maxFrameLength,
+     *                                       after the delimiter has been read.
+     *                                       If true a {@link TooLongFrameException} is thrown immediately
+     *                                       when the length of the frame exceeds maxFrameLength,
+     *                                       regardless of whether a delimiter has been found yet.
+     */
+    public LengthFieldBasedFrameDecoder setFailImmediatelyOnTooLongFrame(
+            boolean failImmediatelyOnTooLongFrame)
+    {
+      this.failImmediatelyOnTooLongFrame = failImmediatelyOnTooLongFrame;
+      return this;
+    }
+
     private void fail(ChannelHandlerContext ctx, long frameLength) {
         if (frameLength > 0) {
             Channels.fireExceptionCaught(

src/test/java/org/jboss/netty/handler/codec/frame/DelimiterBasedFrameDecoderTest.java

@@ -46,4 +46,25 @@ public class DelimiterBasedFrameDecoderTest {
             Assert.assertEquals("A", buf.toString(CharsetUtil.ISO_8859_1));
         }
     }
+
+    @Test
+    public void testFailImmediatelyTooLongFrameRecovery() throws Exception {
+        DecoderEmbedder<ChannelBuffer> embedder = new DecoderEmbedder<ChannelBuffer>(
+                new DelimiterBasedFrameDecoder(1, Delimiters.nulDelimiter()).
+                        setFailImmediatelyOnTooLongFrame(true));
+
+        for (int i = 0; i < 2; i ++) {
+            try {
+                embedder.offer(ChannelBuffers.wrappedBuffer(new byte[] { 1, 2 }));
+                Assert.fail(CodecEmbedderException.class.getSimpleName() + " must be raised.");
+            } catch (CodecEmbedderException e) {
+                Assert.assertTrue(e.getCause() instanceof TooLongFrameException);
+                // Expected
+            }
+
+            embedder.offer(ChannelBuffers.wrappedBuffer(new byte[] { 0, 'A', 0 }));
+            ChannelBuffer buf = embedder.poll();
+            Assert.assertEquals("A", buf.toString(CharsetUtil.ISO_8859_1));
+        }
+    }
 }

src/test/java/org/jboss/netty/handler/codec/frame/LengthFieldBasedFrameDecoderTest.java

@@ -46,4 +46,25 @@ public class LengthFieldBasedFrameDecoderTest {
             Assert.assertEquals("A", buf.toString(CharsetUtil.ISO_8859_1));
         }
     }
+
+    @Test
+    public void testFailImmediatelyTooLongFrameRecovery() throws Exception {
+        DecoderEmbedder<ChannelBuffer> embedder = new DecoderEmbedder<ChannelBuffer>(
+                new LengthFieldBasedFrameDecoder(5, 0, 4, 0, 4).
+                        setFailImmediatelyOnTooLongFrame(true));
+
+        for (int i = 0; i < 2; i ++) {
+            try {
+                embedder.offer(ChannelBuffers.wrappedBuffer(new byte[] { 0, 0, 0, 2 }));
+                Assert.fail(CodecEmbedderException.class.getSimpleName() + " must be raised.");
+            } catch (CodecEmbedderException e) {
+                Assert.assertTrue(e.getCause() instanceof TooLongFrameException);
+                // Expected
+            }
+
+            embedder.offer(ChannelBuffers.wrappedBuffer(new byte[] { 0, 0, 0, 0, 0, 1, 'A' }));
+            ChannelBuffer buf = embedder.poll();
+            Assert.assertEquals("A", buf.toString(CharsetUtil.ISO_8859_1));
+        }
+    }
 }