[#2650] Allow to disable http header validation in SpdyHttpDecoder and SpdyHttpCodec

Motivation:

HTTP header validation can be expensive so we should allow to disable it like we do in HttpObjectDecoder.

Modification:

Add constructor argument to disable validation.

Result:
Performance improvement

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpCodec.java

@@ -28,4 +28,11 @@ public final class SpdyHttpCodec
     public SpdyHttpCodec(SpdyVersion version, int maxContentLength) {
         super(new SpdyHttpDecoder(version, maxContentLength), new SpdyHttpEncoder(version));
     }
+
+    /**
+     * Creates a new instance with the specified decoder options.
+     */
+    public SpdyHttpCodec(SpdyVersion version, int maxContentLength, boolean validateHttpHeaders) {
+        super(new SpdyHttpDecoder(version, maxContentLength, validateHttpHeaders), new SpdyHttpEncoder(version));
+    }
 }

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpDecoder.java

@@ -39,6 +39,7 @@ import java.util.Map;
  */
 public class SpdyHttpDecoder extends MessageToMessageDecoder<SpdyFrame> {
 
+    private final boolean validateHeaders;
     private final int spdyVersion;
     private final int maxContentLength;
     private final Map<Integer, FullHttpMessage> messageMap;
@@ -52,7 +53,20 @@ public class SpdyHttpDecoder extends MessageToMessageDecoder<SpdyFrame> {
      *        a {@link TooLongFrameException} will be raised.
      */
     public SpdyHttpDecoder(SpdyVersion version, int maxContentLength) {
-        this(version, maxContentLength, new HashMap<Integer, FullHttpMessage>());
+        this(version, maxContentLength, new HashMap<Integer, FullHttpMessage>(), true);
+    }
+
+    /**
+     * Creates a new instance.
+     *
+     * @param version the protocol version
+     * @param maxContentLength the maximum length of the message content.
+     *        If the length of the message content exceeds this value,
+     *        a {@link TooLongFrameException} will be raised.
+     * @param validateHeaders {@code true} if http headers should be validated
+     */
+    public SpdyHttpDecoder(SpdyVersion version, int maxContentLength, boolean validateHeaders) {
+        this(version, maxContentLength, new HashMap<Integer, FullHttpMessage>(), validateHeaders);
     }
 
     /**
@@ -65,6 +79,21 @@ public class SpdyHttpDecoder extends MessageToMessageDecoder<SpdyFrame> {
      * @param messageMap the {@link Map} used to hold partially received messages.
      */
     protected SpdyHttpDecoder(SpdyVersion version, int maxContentLength, Map<Integer, FullHttpMessage> messageMap) {
+        this(version, maxContentLength, messageMap, true);
+    }
+
+    /**
+     * Creates a new instance with the specified parameters.
+     *
+     * @param version the protocol version
+     * @param maxContentLength the maximum length of the message content.
+     *        If the length of the message content exceeds this value,
+     *        a {@link TooLongFrameException} will be raised.
+     * @param messageMap the {@link Map} used to hold partially received messages.
+     * @param validateHeaders {@code true} if http headers should be validated
+     */
+    protected SpdyHttpDecoder(SpdyVersion version, int maxContentLength, Map<Integer,
+            FullHttpMessage> messageMap, boolean validateHeaders) {
         if (version == null) {
             throw new NullPointerException("version");
         }
@@ -75,6 +104,7 @@ public class SpdyHttpDecoder extends MessageToMessageDecoder<SpdyFrame> {
         spdyVersion = version.getVersion();
         this.maxContentLength = maxContentLength;
         this.messageMap = messageMap;
+        this.validateHeaders = validateHeaders;
     }
 
     protected FullHttpMessage putMessage(int streamId, FullHttpMessage message) {
@@ -133,7 +163,7 @@ public class SpdyHttpDecoder extends MessageToMessageDecoder<SpdyFrame> {
 
                 try {
                     FullHttpResponse httpResponseWithEntity =
-                            createHttpResponse(spdyVersion, spdySynStreamFrame);
+                            createHttpResponse(ctx, spdyVersion, spdySynStreamFrame, validateHeaders);
 
                     // Set the Stream-ID, Associated-To-Stream-ID, Priority, and URL as headers
                     SpdyHttpHeaders.setStreamId(httpResponseWithEntity, streamId);
@@ -208,7 +238,8 @@ public class SpdyHttpDecoder extends MessageToMessageDecoder<SpdyFrame> {
             }
 
             try {
-                FullHttpResponse httpResponseWithEntity = createHttpResponse(spdyVersion, spdySynReplyFrame);
+                FullHttpResponse httpResponseWithEntity =
+                        createHttpResponse(ctx, spdyVersion, spdySynReplyFrame, validateHeaders);
 
                 // Set the Stream-ID as a header
                 SpdyHttpHeaders.setStreamId(httpResponseWithEntity, streamId);
@@ -323,15 +354,17 @@ public class SpdyHttpDecoder extends MessageToMessageDecoder<SpdyFrame> {
         return req;
     }
 
-    private static FullHttpResponse createHttpResponse(int spdyVersion, SpdyHeadersFrame responseFrame)
+    private static FullHttpResponse createHttpResponse(ChannelHandlerContext ctx, int spdyVersion,
-            throws Exception {
+                                                       SpdyHeadersFrame responseFrame,
+                                                       boolean validateHeaders) throws Exception {
+
         // Create the first line of the response from the name/value pairs
         HttpResponseStatus status = SpdyHeaders.getStatus(spdyVersion, responseFrame);
         HttpVersion version = SpdyHeaders.getVersion(spdyVersion, responseFrame);
         SpdyHeaders.removeStatus(spdyVersion, responseFrame);
         SpdyHeaders.removeVersion(spdyVersion, responseFrame);
 
-        FullHttpResponse res = new DefaultFullHttpResponse(version, status);
+        FullHttpResponse res = new DefaultFullHttpResponse(version, status, ctx.alloc().buffer(), validateHeaders);
         for (Map.Entry<String, String> e: responseFrame.headers()) {
             res.headers().add(e.getKey(), e.getValue());
         }