add status 200 and method GET to ref set

jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackContext.java

@@ -109,14 +109,14 @@ public class HpackContext
     
     private static final Map<HttpField,Entry> __staticFieldMap = new HashMap<>();
     private static final Trie<Entry> __staticNameMap = new ArrayTernaryTrie<>(true,512);
-
-    private static final Entry[] __staticTable=new Entry[STATIC_TABLE.length];
+    
+    private static final StaticEntry[] __staticTable=new StaticEntry[STATIC_TABLE.length];
     static
     {
         Set<String> added = new HashSet<>();
         for (int i=1;i<STATIC_TABLE.length;i++)
         {
-            Entry entry;
+            StaticEntry entry;
             switch(i)
             {
                 case 2:
@@ -159,6 +159,10 @@ public class HpackContext
             }
         }
     }
+
+    public static final StaticEntry METHOD_GET=__staticTable[2];
+    public static final StaticEntry STATUS_200=__staticTable[8];
+    
     
     private int _maxHeaderTableSizeInBytes;
     private int _headerTableSizeInBytes;

jetty-http2/http2-hpack/src/main/java/org/eclipse/jetty/http2/hpack/HpackEncoder.java

@@ -172,32 +172,46 @@ public class HpackEncoder
             {
                 // TODO Strategy decision to make!
                 // Should we add to reference set or just always send as indexed?
-                // Let's always send as indexed to reduce churn in header table!
-                // BUGGER! Can't do that.  Oh well all the static fields have small values, so
-                // lets send as literal header, indexed name.
-                // We don't need never indexed because the cookie fields are name only and we can
-                // huffman encode the value for the same reason. 
 
-                // Add the token
-                buffer.put((byte)0x00);
-                // Add the name index
-                NBitInteger.encode(buffer,4,_context.index(entry));
-                // Add the value
-                buffer.put(entry.getStaticHuffmanValue());
+                if (entry==HpackContext.METHOD_GET || entry==HpackContext.STATUS_200)
+                {
+                    // :status: 200 and :method: GET are worthwhile putting into ref set.
+                    // as they are likely to be repeated.
+                    int index=_context.index(entry);
+                    buffer.put((byte)0x80);
+                    NBitInteger.encode(buffer,7,index);
+                    entry=_context.add(entry.getHttpField());
+                    if (entry!=null)
+                        _context.addToRefSet(entry);
+                }
+                else
+                {        
+                    // Let's send other statics as indexed to reduce churn in header table!
+                    // BUGGER! Can't do that as we have to copy them into header table.
+                    // Oh well all the static fields have small values, so
+                    // lets send as literal header, indexed name.
+                    // We don't need never indexed because the cookie fields are name only and we can
+                    // huffman encode the value for the same reason. 
+                    
+                    // Add the token
+                    buffer.put((byte)0x00);
+                    // Add the name index
+                    NBitInteger.encode(buffer,4,_context.index(entry));
+                    // Add the value
+                    buffer.put(entry.getStaticHuffmanValue());
 
-                encoding="LiteralStaticIdxNameHuffmanValue";
+                    encoding="LiteralStaticIdxNameHuffmanValue";
+                }
             }
             else
             {
                 encoding="IdxField";
 
-                // So we can add the entry to the reference Set and emit the index;
-                _context.addToRefSet(entry);
+                // So we can emit the index and add the entry to the reference Set
                 int index=_context.index(entry);
-
-                // TODO pregenerate indexes?
                 buffer.put((byte)0x80);
                 NBitInteger.encode(buffer,7,index);
+                _context.addToRefSet(entry);
             }
         }
         else

jetty-http2/http2-server/src/test/java/org/eclipse/jetty/http2/server/Http2Server.java

@@ -118,7 +118,6 @@ public class Http2Server
         protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
         {
             response.setHeader("custom","value");
-            response.sendRedirect("http://www.google.com");
             response.setContentType("text/plain");
             String content = "Hello from Jetty HTTP2\n";
             response.setContentLength(content.length());