From 942b746d730566001301f8edc774d571bcbbf175 Mon Sep 17 00:00:00 2001
From: Sun Ning <classicning@gmail.com>
Date: Sat, 5 Nov 2011 22:09:27 +0800
Subject: [PATCH] add an option in LengthFieldBasedFrameDecoder for whether to
 count the length field into frame length.

---
 .../frame/LengthFieldBasedFrameDecoder.java   | 34 +++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/jboss/netty/handler/codec/frame/LengthFieldBasedFrameDecoder.java b/src/main/java/org/jboss/netty/handler/codec/frame/LengthFieldBasedFrameDecoder.java
index 292f24a68e..2733109f29 100644
--- a/src/main/java/org/jboss/netty/handler/codec/frame/LengthFieldBasedFrameDecoder.java
+++ b/src/main/java/org/jboss/netty/handler/codec/frame/LengthFieldBasedFrameDecoder.java
@@ -195,6 +195,7 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
     private final int lengthFieldEndOffset;
     private final int lengthAdjustment;
     private final int initialBytesToStrip;
+    private final boolean lengthFieldIncludedInFrameLength;
     private boolean discardingTooLongFrame;
     private long tooLongFrameLength;
     private long bytesToDiscard;
@@ -215,7 +216,7 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
     public LengthFieldBasedFrameDecoder(
             int maxFrameLength,
             int lengthFieldOffset, int lengthFieldLength) {
-        this(maxFrameLength, lengthFieldOffset, lengthFieldLength, 0, 0);
+        this(maxFrameLength, lengthFieldOffset, lengthFieldLength, 0, 0, false);
     }
 
     /**
@@ -238,6 +239,32 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
             int maxFrameLength,
             int lengthFieldOffset, int lengthFieldLength,
             int lengthAdjustment, int initialBytesToStrip) {
+        this(maxFrameLength, lengthFieldOffset, lengthFieldOffset, lengthAdjustment,
+                initialBytesToStrip, false);
+    }
+
+    /**
+     * Creates a new instance.
+     *
+     * @param maxFrameLength
+     *        the maximum length of the frame.  If the length of the frame is
+     *        greater than this value, {@link TooLongFrameException} will be
+     *        thrown.
+     * @param lengthFieldOffset
+     *        the offset of the length field
+     * @param lengthFieldLength
+     *        the length of the length field
+     * @param lengthAdjustment
+     *        the compensation value to add to the value of the length field
+     * @param initialBytesToStrip
+     *        the number of first bytes to strip out from the decoded frame
+     * @param lengthFieldIncludedInFrameLength
+     *        whether to count length field into frame length
+     */
+    public LengthFieldBasedFrameDecoder(
+            int maxFrameLength,
+            int lengthFieldOffset, int lengthFieldLength,
+            int lengthAdjustment, int initialBytesToStrip, boolean lengthFieldIncludedInFrameLength) {
         if (maxFrameLength <= 0) {
             throw new IllegalArgumentException(
                     "maxFrameLength must be a positive integer: " +
@@ -278,6 +305,7 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
         this.lengthAdjustment = lengthAdjustment;
         lengthFieldEndOffset = lengthFieldOffset + lengthFieldLength;
         this.initialBytesToStrip = initialBytesToStrip;
+        this.lengthFieldIncludedInFrameLength = lengthFieldIncludedInFrameLength;
     }
 
     @Override
@@ -326,7 +354,9 @@ public class LengthFieldBasedFrameDecoder extends FrameDecoder {
                     "negative pre-adjustment length field: " + frameLength);
         }
 
-        frameLength += lengthAdjustment + lengthFieldEndOffset;
+        if (!lengthFieldIncludedInFrameLength) {
+            frameLength += lengthAdjustment + lengthFieldEndOffset;
+        }
         if (frameLength < lengthFieldEndOffset) {
             buffer.skipBytes(lengthFieldEndOffset);
             throw new CorruptedFrameException(