From 45724b63ecfd9d9a01c4490166a866be3184fcfa Mon Sep 17 00:00:00 2001
From: Simone Bordet <simone.bordet@gmail.com>
Date: Mon, 19 Aug 2013 22:11:52 +0200
Subject: [PATCH] Improved masking performance by using ints instead of bytes.

---
 .../jetty/websocket/common/Generator.java     | 29 +++++++++------
 .../common/io/payload/DeMaskProcessor.java    | 37 ++++++++++---------
 .../io/payload/DeMaskProcessorTest.java       |  4 +-
 3 files changed, 39 insertions(+), 31 deletions(-)

diff --git a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/Generator.java b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/Generator.java
index 6e1b7f12a35..10580b2d2e3 100644
--- a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/Generator.java
+++ b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/Generator.java
@@ -282,24 +282,29 @@ public class Generator
         {
             byte[] mask = frame.getMask();
             buffer.put(mask);
+            int maskInt = ByteBuffer.wrap(mask).getInt();
 
             // perform data masking here
-            byte mb;
             ByteBuffer payload = frame.getPayload();
             if ((payload != null) && (payload.remaining() > 0))
             {
-                int pos = payload.position();
-                int limit = payload.limit();
-                for (int i = pos; i < limit; i++)
+                int maskOffset = 0;
+                int start = payload.position();
+                int end = payload.limit();
+                int remaining;
+                while ((remaining = end - start) > 0)
                 {
-                    // get raw byte from buffer.
-                    mb = payload.get(i);
-
-                    // mask, using offset information from frame windowing.
-                    mb ^= mask[(i - pos) % 4];
-
-                    // Mask each byte by its absolute position in the payload bytebuffer
-                    payload.put(i,mb);
+                    if (remaining >= 4)
+                    {
+                        payload.putInt(start, payload.getInt(start) ^ maskInt);
+                        start += 4;
+                    }
+                    else
+                    {
+                        payload.put(start, (byte)(payload.get(start) ^ mask[maskOffset & 3]));
+                        ++start;
+                        ++maskOffset;
+                    }
                 }
             }
         }
diff --git a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessor.java b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessor.java
index ead2bc94ca5..9d6d062f0f6 100644
--- a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessor.java
+++ b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessor.java
@@ -24,39 +24,42 @@ import org.eclipse.jetty.websocket.api.extensions.Frame;
 
 public class DeMaskProcessor implements PayloadProcessor
 {
-    private boolean isMasked;
-    private byte mask[];
-    private int offset;
+    private byte maskBytes[];
+    private int maskOffset;
 
     @Override
     public void process(ByteBuffer payload)
     {
-        if (!isMasked)
+        if (maskBytes == null)
         {
             return;
         }
 
+        int maskInt = ByteBuffer.wrap(maskBytes).getInt();
         int start = payload.position();
         int end = payload.limit();
-        for (int i = start; i < end; i++, offset++)
+        int offset = this.maskOffset;
+        int remaining;
+        while ((remaining = end - start) > 0)
         {
-            payload.put(i,(byte)(payload.get(i) ^ mask[offset % 4]));
+            if (remaining >= 4 && offset == 0)
+            {
+                payload.putInt(start, payload.getInt(start) ^ maskInt);
+                start +=4;
+            }
+            else
+            {
+                payload.put(start, (byte)(payload.get(start) ^ maskBytes[offset & 3]));
+                ++start;
+                ++offset;
+            }
         }
     }
 
     @Override
     public void reset(Frame frame)
     {
-        this.isMasked = frame.isMasked();
-        if (isMasked)
-        {
-            this.mask = frame.getMask();
-        }
-        else
-        {
-            this.mask = null;
-        }
-
-        offset = 0;
+        this.maskBytes = frame.isMasked() ? frame.getMask() : null;
+        this.maskOffset = 0;
     }
 }
diff --git a/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessorTest.java b/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessorTest.java
index b3b9bdb94dd..5f53dbea640 100644
--- a/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessorTest.java
+++ b/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/io/payload/DeMaskProcessorTest.java
@@ -27,7 +27,6 @@ import org.eclipse.jetty.util.log.Logger;
 import org.eclipse.jetty.websocket.common.ByteBufferAssert;
 import org.eclipse.jetty.websocket.common.UnitGenerator;
 import org.eclipse.jetty.websocket.common.WebSocketFrame;
-import org.eclipse.jetty.websocket.common.io.payload.DeMaskProcessor;
 import org.junit.Test;
 
 public class DeMaskProcessorTest
@@ -37,7 +36,8 @@ public class DeMaskProcessorTest
     @Test
     public void testDeMaskText()
     {
-        String message = "0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF";
+        // Use a string that is not multiple of 4 in length to test if/else branches in DeMaskProcessor
+        String message = "0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF0123456789ABCDEF01";
 
         WebSocketFrame frame = WebSocketFrame.text(message);
         frame.setMask(TypeUtil.fromHexString("11223344"));