partial 100 continues support in http2

jetty-http2/http2-server/src/main/java/org/eclipse/jetty/http2/server/HTTP2ServerConnectionFactory.java

@@ -100,7 +100,7 @@ public class HTTP2ServerConnectionFactory extends AbstractHTTP2ServerConnectionF
             HttpChannelOverHTTP2 channel = new HttpChannelOverHTTP2(connector, httpConfiguration, endPoint, transport, input, stream);
             stream.setAttribute(CHANNEL_ATTRIBUTE, channel);
 
-            channel.requestHeaders(frame);
+            channel.onHeadersFrame(frame);
 
             return frame.isEndStream() ? null : this;
         }

jetty-http2/http2-server/src/main/java/org/eclipse/jetty/http2/server/HttpChannelOverHTTP2.java

@@ -18,11 +18,14 @@
 
 package org.eclipse.jetty.http2.server;
 
+import java.io.IOException;
 import java.nio.ByteBuffer;
 
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFields;
+import org.eclipse.jetty.http.HttpGenerator;
 import org.eclipse.jetty.http.HttpHeader;
+import org.eclipse.jetty.http.HttpHeaderValue;
 import org.eclipse.jetty.http.MetaData;
 import org.eclipse.jetty.http2.api.Stream;
 import org.eclipse.jetty.http2.frames.DataFrame;
@@ -46,6 +49,7 @@ public class HttpChannelOverHTTP2 extends HttpChannel
     private static final HttpField SERVER_VERSION=new HttpField(HttpHeader.SERVER,HttpConfiguration.SERVER_VERSION);
     private static final HttpField POWERED_BY=new HttpField(HttpHeader.X_POWERED_BY,HttpConfiguration.SERVER_VERSION);
     private final Stream stream; // TODO recycle channel for new Stream?
+    private boolean _expect100Continue = false;
 
     public HttpChannelOverHTTP2(Connector connector, HttpConfiguration configuration, EndPoint endPoint, HttpTransport transport, HttpInput input, Stream stream)
     {
@@ -53,7 +57,13 @@ public class HttpChannelOverHTTP2 extends HttpChannel
         this.stream = stream;
     }
 
-    public void requestHeaders(HeadersFrame frame)
+    @Override
+    public boolean isExpecting100Continue()
+    {
+        return _expect100Continue;
+    }
+    
+    public void onHeadersFrame(HeadersFrame frame)
     {
         MetaData metaData = frame.getMetaData();
         if (!metaData.isRequest())
@@ -63,22 +73,20 @@ public class HttpChannelOverHTTP2 extends HttpChannel
         }
 
         MetaData.Request request = (MetaData.Request)metaData;
-
-        // The specification says user agents MUST support gzip encoding.
-        // Based on that, some browser does not send the header, but it's
-        // important that applications can find it (e.g. GzipFilter).
         HttpFields fields = request.getFields();
-        if (!fields.contains(HttpHeader.ACCEPT_ENCODING, "gzip"))
-            fields.add(ACCEPT_ENCODING_GZIP);
+        
+        _expect100Continue = fields.contains(HttpHeader.EXPECT,HttpHeaderValue.CONTINUE.asString());
 
         // TODO make this a better field for h2 hpack generation
+        HttpFields response=getResponse().getHttpFields();
         if (getHttpConfiguration().getSendServerVersion())
-            getResponse().getHttpFields().add(SERVER_VERSION);
+            response.add(SERVER_VERSION);
         if (getHttpConfiguration().getSendXPoweredBy())
-            getResponse().getHttpFields().add(POWERED_BY);
+            response.add(POWERED_BY);
         
         onRequest(request);
         
+        
         if (frame.isEndStream())
         {
             onRequestComplete();
@@ -127,4 +135,33 @@ public class HttpChannelOverHTTP2 extends HttpChannel
             onRequestComplete();
         }
     }
+
+    /**
+     * If the associated response has the Expect header set to 100 Continue,
+     * then accessing the input stream indicates that the handler/servlet
+     * is ready for the request body and thus a 100 Continue response is sent.
+     *
+     * @throws IOException if the InputStream cannot be created
+     */
+    @Override
+    public void continue100(int available) throws IOException
+    {
+        // If the client is expecting 100 CONTINUE, then send it now.
+        // TODO: consider using an AtomicBoolean ?
+        if (isExpecting100Continue())
+        {
+            _expect100Continue = false;
+
+            // is content missing?
+            if (available == 0)
+            {
+                if (getResponse().isCommitted())
+                    throw new IOException("Committed before 100 Continues");
+
+                boolean committed = sendResponse(HttpGenerator.CONTINUE_100_INFO, null, false);
+                if (!committed)
+                    throw new IOException("Concurrent commit while trying to send 100-Continue");
+            }
+        }
+    }
 }

jetty-server/src/main/java/org/eclipse/jetty/server/HttpChannelOverHttp.java

@@ -199,7 +199,6 @@ class HttpChannelOverHttp extends HttpChannel implements HttpParser.RequestHandl
                 if (getResponse().isCommitted())
                     throw new IOException("Committed before 100 Continues");
 
-                // TODO: break this dependency with HttpGenerator
                 boolean committed = sendResponse(HttpGenerator.CONTINUE_100_INFO, null, false);
                 if (!committed)
                     throw new IOException("Concurrent commit while trying to send 100-Continue");