DataInfo javadocs + modified slightly the API for helper methods, passing a boolean telling to read or consume the bytes.

spdy-core/src/main/java/org/eclipse/jetty/spdy/api/DataInfo.java

@@ -28,6 +28,16 @@ import java.util.concurrent.atomic.AtomicInteger;
  * type, via {@link Stream#data(DataInfo)}. The last instance must have the
  * {@link #isClose() close flag} set, so that the client knows that no more content is
  * expected.</p>
+ * <p>Receivers of {@link DataInfo} via {@link StreamFrameListener#onData(Stream, DataInfo)}
+ * have two different APIs to read the data content bytes: a {@link #readInto(ByteBuffer) read}
+ * API that does not interact with flow control, and a {@link #drainInto(ByteBuffer) drain}
+ * API that interacts with flow control.</p>
+ * <p>Flow control is defined so that when the sender wants to sends a number of bytes larger
+ * than the {@link Settings.ID#INITIAL_WINDOW_SIZE} value, it will stop sending as soon as it
+ * has sent a number of bytes equal to the window size. The receiver has to <em>consume</em>
+ * the data bytes that it received in order to tell the sender to send more bytes.</p>
+ * <p>Consuming the data bytes can be done only via {@link #drainInto(ByteBuffer)} or by a combination
+ * of {@link #readInto(ByteBuffer)} and {@link #consume(int)} (possibly at different times).</p>
  */
 public abstract class DataInfo
 {
@@ -139,15 +149,23 @@ public abstract class DataInfo
     /**
      * <p>Copies the content bytes of this {@link DataInfo} into the given {@link ByteBuffer}.</p>
      * <p>If the given {@link ByteBuffer} cannot contain the whole content of this {@link DataInfo}
-     * then {@link #available()} will return a positive value, and further content
+     * then after the read {@link #available()} will return a positive value, and further content
-     * may be retrieved by invoking again this method.</p>
+     * may be retrieved by invoking again this method with a new output buffer.</p>
      *
      * @param output the {@link ByteBuffer} to copy to bytes into
      * @return the number of bytes copied
      * @see #available()
+     * @see #drainInto(ByteBuffer)
      */
     public abstract int readInto(ByteBuffer output);
 
+    /**
+     * <p>Reads and consumes the content bytes of this {@link DataInfo} into the given {@link ByteBuffer}.</p>
+     *
+     * @param output the {@link ByteBuffer} to copy to bytes into
+     * @return the number of bytes copied
+     * @see #consume(int)
+     */
     public int drainInto(ByteBuffer output)
     {
         int read = readInto(output);
@@ -155,8 +173,15 @@ public abstract class DataInfo
         return read;
     }
 
+    /**
+     * <p>Consumes the given number of bytes from this {@link DataInfo}.</p>
+     *
+     * @param delta the number of bytes consumed
+     */
     public void consume(int delta)
     {
+        if (delta < 0)
+            throw new IllegalArgumentException();
         int read = length() - available();
         int newConsumed = consumed() + delta;
         if (newConsumed > read)
@@ -164,31 +189,33 @@ public abstract class DataInfo
         consumed.addAndGet(delta);
     }
 
+    /**
+     * @return the number of bytes consumed
+     */
     public int consumed()
     {
         return consumed.get();
     }
 
     /**
+     *
      * @param charset the charset used to convert the bytes
+     * @param consume whether to consume the content
      * @return a String with the content of this {@link DataInfo}
      */
-    public String asString(String charset)
+    public String asString(String charset, boolean consume)
     {
-        ByteBuffer buffer = ByteBuffer.allocate(available());
+        ByteBuffer buffer = asByteBuffer(consume);
-        readInto(buffer);
-        buffer.flip();
         return Charset.forName(charset).decode(buffer).toString();
     }
 
     /**
      * @return a byte array with the content of this {@link DataInfo}
+     * @param consume whether to consume the content
      */
-    public byte[] asBytes()
+    public byte[] asBytes(boolean consume)
     {
-        ByteBuffer buffer = ByteBuffer.allocate(available());
+        ByteBuffer buffer = asByteBuffer(consume);
-        readInto(buffer);
-        buffer.flip();
         byte[] result = new byte[buffer.remaining()];
         buffer.get(result);
         return result;
@@ -196,10 +223,14 @@ public abstract class DataInfo
 
     /**
      * @return a {@link ByteBuffer} with the content of this {@link DataInfo}
+     * @param consume whether to consume the content
      */
-    public ByteBuffer asByteBuffer()
+    public ByteBuffer asByteBuffer(boolean consume)
     {
         ByteBuffer buffer = ByteBuffer.allocate(available());
+        if (consume)
+            drainInto(buffer);
+        else
             readInto(buffer);
         buffer.flip();
         return buffer;

spdy-core/src/test/java/org/eclipse/jetty/spdy/api/ClientUsageTest.java

@@ -130,7 +130,7 @@ public class ClientUsageTest
             public void onData(Stream stream, DataInfo dataInfo)
             {
                 StringBuilder builder = (StringBuilder)stream.getAttribute("builder");
-                builder.append(dataInfo.asString("UTF-8"));
+                builder.append(dataInfo.asString("UTF-8", true));
                 if (dataInfo.isClose())
                 {
                     int receivedLength = builder.toString().getBytes(Charset.forName("UTF-8")).length;

spdy-jetty-http/src/main/java/org/eclipse/jetty/spdy/http/ServerHTTPSPDYAsyncConnectionFactory.java

@@ -159,7 +159,7 @@ public class ServerHTTPSPDYAsyncConnectionFactory extends ServerSPDYAsyncConnect
             logger.debug("Received {} on {}", dataInfo, stream);
 
             final ServerHTTPSPDYAsyncConnection connection = (ServerHTTPSPDYAsyncConnection)stream.getAttribute("connection");
-            final ByteBuffer buffer = dataInfo.asByteBuffer();
+            final ByteBuffer buffer = dataInfo.asByteBuffer(true);
             final boolean isClose = dataInfo.isClose();
 
             connection.post(new Runnable()

spdy-jetty-http/src/test/java/org/eclipse/jetty/spdy/http/ServerHTTPSPDYTest.java

@@ -349,7 +349,7 @@ public class ServerHTTPSPDYTest extends AbstractHTTPSPDYTest
             public void onData(Stream stream, DataInfo dataInfo)
             {
                 Assert.assertTrue(dataInfo.isClose());
-                Assert.assertEquals(data, dataInfo.asString("UTF-8"));
+                Assert.assertEquals(data, dataInfo.asString("UTF-8", true));
                 dataLatch.countDown();
             }
         });
@@ -399,7 +399,7 @@ public class ServerHTTPSPDYTest extends AbstractHTTPSPDYTest
             public void onData(Stream stream, DataInfo dataInfo)
             {
                 Assert.assertTrue(dataInfo.isClose());
-                byte[] bytes = dataInfo.asBytes();
+                byte[] bytes = dataInfo.asBytes(true);
                 Assert.assertEquals(1, bytes.length);
                 Assert.assertEquals(data, bytes[0]);
                 dataLatch.countDown();
@@ -460,9 +460,9 @@ public class ServerHTTPSPDYTest extends AbstractHTTPSPDYTest
                 int data = dataFrames.incrementAndGet();
                 Assert.assertTrue(data >= 1 && data <= 2);
                 if (data == 1)
-                    Assert.assertEquals(data1, dataInfo.asString("UTF8"));
+                    Assert.assertEquals(data1, dataInfo.asString("UTF8", true));
                 else
-                    Assert.assertEquals(data2, dataInfo.asString("UTF8"));
+                    Assert.assertEquals(data2, dataInfo.asString("UTF8", true));
                 dataLatch.countDown();
             }
         });
@@ -628,7 +628,7 @@ public class ServerHTTPSPDYTest extends AbstractHTTPSPDYTest
             @Override
             public void onData(Stream stream, DataInfo dataInfo)
             {
-                ByteBuffer byteBuffer = dataInfo.asByteBuffer();
+                ByteBuffer byteBuffer = dataInfo.asByteBuffer(true);
                 while (byteBuffer.hasRemaining())
                     buffer.write(byteBuffer.get());
                 if (dataInfo.isClose())
@@ -690,7 +690,7 @@ public class ServerHTTPSPDYTest extends AbstractHTTPSPDYTest
             @Override
             public void onData(Stream stream, DataInfo dataInfo)
             {
-                ByteBuffer byteBuffer = dataInfo.asByteBuffer();
+                ByteBuffer byteBuffer = dataInfo.asByteBuffer(true);
                 while (byteBuffer.hasRemaining())
                     buffer.write(byteBuffer.get());
                 if (dataInfo.isClose())
@@ -887,12 +887,12 @@ public class ServerHTTPSPDYTest extends AbstractHTTPSPDYTest
                 if (count == 1)
                 {
                     Assert.assertFalse(dataInfo.isClose());
-                    Assert.assertEquals(pangram1, dataInfo.asString("UTF-8"));
+                    Assert.assertEquals(pangram1, dataInfo.asString("UTF-8", true));
                 }
                 else if (count == 2)
                 {
                     Assert.assertTrue(dataInfo.isClose());
-                    Assert.assertEquals(pangram2, dataInfo.asString("UTF-8"));
+                    Assert.assertEquals(pangram2, dataInfo.asString("UTF-8", true));
                 }
                 dataLatch.countDown();
             }
@@ -949,7 +949,7 @@ public class ServerHTTPSPDYTest extends AbstractHTTPSPDYTest
             {
                 Assert.assertEquals(1, dataFrames.incrementAndGet());
                 Assert.assertTrue(dataInfo.isClose());
-                Assert.assertArrayEquals(data, dataInfo.asBytes());
+                Assert.assertArrayEquals(data, dataInfo.asBytes(true));
                 dataLatch.countDown();
             }
         });

spdy-jetty/src/test/java/org/eclipse/jetty/spdy/SynReplyTest.java

@@ -232,13 +232,13 @@ public class SynReplyTest extends AbstractTest
                 int dataCount = this.dataCount.incrementAndGet();
                 if (dataCount == 1)
                 {
-                    String chunk1 = dataInfo.asString("UTF-8");
+                    String chunk1 = dataInfo.asString("UTF-8", true);
                     Assert.assertEquals(data1, chunk1);
                     dataLatch1.countDown();
                 }
                 else if (dataCount == 2)
                 {
-                    String chunk2 = dataInfo.asString("UTF-8");
+                    String chunk2 = dataInfo.asString("UTF-8", true);
                     Assert.assertEquals(data2, chunk2);
                     dataLatch2.countDown();
                 }
@@ -274,7 +274,7 @@ public class SynReplyTest extends AbstractTest
                     @Override
                     public void onData(Stream stream, DataInfo dataInfo)
                     {
-                        String data = dataInfo.asString("UTF-8");
+                        String data = dataInfo.asString("UTF-8", true);
                         Assert.assertEquals(clientData, data);
                         clientDataLatch.countDown();
                     }
@@ -393,7 +393,7 @@ public class SynReplyTest extends AbstractTest
             @Override
             public void onData(Stream stream, DataInfo dataInfo)
             {
-                String chunk = dataInfo.asString("UTF-8");
+                String chunk = dataInfo.asString("UTF-8", true);
                 Assert.assertEquals(data, chunk);
                 dataLatch.countDown();
             }