Improved usability of PingFrame.

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/frames/PingFrame.java

@@ -18,15 +18,49 @@
 
 package org.eclipse.jetty.http2.frames;
 
+import java.util.Objects;
+
 public class PingFrame extends Frame
 {
+    public static final int PING_LENGTH = 8;
+    private static final byte[] EMPTY_PAYLOAD = new byte[8];
+
     private final byte[] payload;
     private final boolean reply;
 
+    /**
+     * Creates a PING frame with an empty payload.
+     *
+     * @param reply whether this PING frame is a reply
+     */
+    public PingFrame(boolean reply)
+    {
+        this(EMPTY_PAYLOAD, reply);
+    }
+
+    /**
+     * Creates a PING frame with the given {@code long} {@code value} as payload.
+     *
+     * @param value the value to use as a payload for this PING frame
+     * @param reply whether this PING frame is a reply
+     */
+    public PingFrame(long value, boolean reply)
+    {
+        this(toBytes(value), reply);
+    }
+
+    /**
+     * Creates a PING frame with the given {@code payload}.
+     *
+     * @param payload the payload for this PING frame
+     * @param reply whether this PING frame is a reply
+     */
     public PingFrame(byte[] payload, boolean reply)
     {
         super(FrameType.PING);
-        this.payload = payload;
+        this.payload = Objects.requireNonNull(payload);
+        if (payload.length != PING_LENGTH)
+            throw new IllegalArgumentException("PING payload must be 8 bytes");
         this.reply = reply;
     }
 
@@ -35,8 +69,35 @@ public class PingFrame extends Frame
         return payload;
     }
 
+    public long getPayloadAsLong()
+    {
+        return toLong(payload);
+    }
+
     public boolean isReply()
     {
         return reply;
     }
+
+    private static byte[] toBytes(long value)
+    {
+        byte[] result = new byte[8];
+        for (int i = result.length - 1; i >= 0; --i)
+        {
+            result[i] = (byte)(value & 0xFF);
+            value >>= 8;
+        }
+        return result;
+    }
+
+    private static long toLong(byte[] payload)
+    {
+        long result = 0;
+        for (int i = 0; i < 8; ++i)
+        {
+            result <<= 8;
+            result |= (payload[i] & 0xFF);
+        }
+        return result;
+    }
 }

jetty-http2/http2-common/src/main/java/org/eclipse/jetty/http2/generator/PingGenerator.java

@@ -43,10 +43,10 @@ public class PingGenerator extends FrameGenerator
 
     public void generatePing(ByteBufferPool.Lease lease, byte[] payload, boolean reply)
     {
-        if (payload.length != 8)
+        if (payload.length != PingFrame.PING_LENGTH)
             throw new IllegalArgumentException("Invalid payload length: " + payload.length);
 
-        ByteBuffer header = generateHeader(lease, FrameType.PING, 8, reply ? Flags.ACK : Flags.NONE, 0);
+        ByteBuffer header = generateHeader(lease, FrameType.PING, PingFrame.PING_LENGTH, reply ? Flags.ACK : Flags.NONE, 0);
 
         header.put(payload);
 

jetty-http2/http2-common/src/test/java/org/eclipse/jetty/http2/frames/PingGenerateParseTest.java

@@ -109,4 +109,37 @@ public class PingGenerateParseTest
         Assert.assertArrayEquals(payload, frame.getPayload());
         Assert.assertTrue(frame.isReply());
     }
+
+    @Test
+    public void testPayloadAsLong() throws Exception
+    {
+        PingGenerator generator = new PingGenerator(new HeaderGenerator());
+
+        final List<PingFrame> frames = new ArrayList<>();
+        Parser parser = new Parser(byteBufferPool, new Parser.Listener.Adapter()
+        {
+            @Override
+            public void onPing(PingFrame frame)
+            {
+                frames.add(frame);
+            }
+        }, 4096, 8192);
+
+        ByteBufferPool.Lease lease = new ByteBufferPool.Lease(byteBufferPool);
+        PingFrame ping = new PingFrame(System.nanoTime(), true);
+        generator.generate(lease, ping);
+
+        for (ByteBuffer buffer : lease.getByteBuffers())
+        {
+            while (buffer.hasRemaining())
+            {
+                parser.parse(buffer);
+            }
+        }
+
+        Assert.assertEquals(1, frames.size());
+        PingFrame pong = frames.get(0);
+        Assert.assertEquals(ping.getPayloadAsLong(), pong.getPayloadAsLong());
+        Assert.assertTrue(pong.isReply());
+    }
 }