From 81e2bfd0c7edee70274daf5e309d4861c483a6c8 Mon Sep 17 00:00:00 2001
From: Greg Wilkins <gregw@webtide.com>
Date: Wed, 26 Oct 2016 11:19:47 +1100
Subject: [PATCH] Improve HttpField preencoding #1031

---
 .../jetty/http/PreEncodedHttpField.java       | 51 ++++++++++++++-----
 1 file changed, 39 insertions(+), 12 deletions(-)

diff --git a/jetty-http/src/main/java/org/eclipse/jetty/http/PreEncodedHttpField.java b/jetty-http/src/main/java/org/eclipse/jetty/http/PreEncodedHttpField.java
index 6c81a914693..8a49a986660 100644
--- a/jetty-http/src/main/java/org/eclipse/jetty/http/PreEncodedHttpField.java
+++ b/jetty-http/src/main/java/org/eclipse/jetty/http/PreEncodedHttpField.java
@@ -21,6 +21,7 @@ package org.eclipse.jetty.http;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Iterator;
 import java.util.List;
 import java.util.ServiceLoader;
@@ -51,30 +52,56 @@ public class PreEncodedHttpField extends HttpField
         {
             try
             {
-                encoders.add(iter.next());
+                HttpFieldPreEncoder encoder = iter.next();
+                if (index(encoder.getHttpVersion())>=0)
+                    encoders.add(encoder);
             }
             catch(Error|RuntimeException e)
             {
                 LOG.debug(e);
             }
         }
-        // TODO avoid needing this catch all
-        if (encoders.size()==0)
-            encoders.add(new Http1FieldPreEncoder());
         LOG.debug("HttpField encoders loaded: {}",encoders);
-        __encoders = encoders.toArray(new HttpFieldPreEncoder[encoders.size()]);
+        int size=encoders.size();
+        
+        __encoders = new HttpFieldPreEncoder[size==0?1:size];
+        for (HttpFieldPreEncoder e:encoders)
+        {
+            int i = index(e.getHttpVersion());
+            if (__encoders[i]==null)
+                __encoders[i] = e;
+            else
+                LOG.warn("multiple PreEncoders for "+e.getHttpVersion());
+        }
+        
+        // Always support HTTP1
+        if (__encoders[0]==null)
+            __encoders[0] = new Http1FieldPreEncoder();              
     }
     
-    private final byte[][] _encodedField=new byte[2][];
+    private static int index(HttpVersion version)
+    {
+        switch (version)
+        {
+            case HTTP_1_0:
+            case HTTP_1_1:
+                return 0;
+
+            case HTTP_2:
+                return 1;
+
+            default:
+                return -1;
+        }
+    }
+    
+    private final byte[][] _encodedField=new byte[__encoders.length][];
 
     public PreEncodedHttpField(HttpHeader header,String name,String value)
     {
         super(header,name, value);
-        
-        for (HttpFieldPreEncoder e:__encoders)
-        {
-            _encodedField[e.getHttpVersion()==HttpVersion.HTTP_2?1:0]=e.getEncodedField(header,header.asString(),value);
-        }
+        for (int i=0;i<__encoders.length;i++)
+            _encodedField[i]=__encoders[i].getEncodedField(header,header.asString(),value);
     }
     
     public PreEncodedHttpField(HttpHeader header,String value)
@@ -89,6 +116,6 @@ public class PreEncodedHttpField extends HttpField
     
     public void putTo(ByteBuffer bufferInFillMode, HttpVersion version)
     {
-        bufferInFillMode.put(_encodedField[version==HttpVersion.HTTP_2?1:0]);
+        bufferInFillMode.put(_encodedField[index(version)]);
     }
 }
\ No newline at end of file