HTTP/2 Decompress Flow Control

Motivation:
The current decompression frame listener currently opts-out of application level flow control. The application should still be able to control flow control even if decompression is in use.

Modifications:
- DecompressorFrameListener will maintain how many compressed bytes, decompressed bytes, and processed by the listener bytes.  A ratio will be used to translate these values into application level flow control amount.

Result:
HTTP/2 decompressor delegates the application level flow control to the listener processing the decompressed data.

codec-http2/src/main/java/io/netty/handler/codec/http2/CompressorHttp2ConnectionEncoder.java

@@ -41,7 +41,7 @@ public class CompressorHttp2ConnectionEncoder extends DefaultHttp2ConnectionEnco
     private static final Http2ConnectionAdapter CLEAN_UP_LISTENER = new Http2ConnectionAdapter() {
         @Override
         public void streamRemoved(Http2Stream stream) {
-            final EmbeddedChannel compressor = stream.compressor();
+            final EmbeddedChannel compressor = stream.getProperty(CompressorHttp2ConnectionEncoder.class);
             if (compressor != null) {
                 cleanup(stream, compressor);
             }
@@ -103,19 +103,24 @@ public class CompressorHttp2ConnectionEncoder extends DefaultHttp2ConnectionEnco
     public ChannelFuture writeData(final ChannelHandlerContext ctx, final int streamId, ByteBuf data, int padding,
             final boolean endOfStream, ChannelPromise promise) {
         final Http2Stream stream = connection().stream(streamId);
-        final EmbeddedChannel compressor = stream == null ? null : stream.compressor();
+        final EmbeddedChannel channel = stream == null ? null :
-        if (compressor == null) {
+            (EmbeddedChannel) stream.getProperty(CompressorHttp2ConnectionEncoder.class);
+        if (channel == null) {
             // The compressor may be null if no compatible encoding type was found in this stream's headers
             return super.writeData(ctx, streamId, data, padding, endOfStream, promise);
         }
 
         try {
             // call retain here as it will call release after its written to the channel
-            compressor.writeOutbound(data.retain());
+            channel.writeOutbound(data.retain());
-            ByteBuf buf = nextReadableBuf(compressor);
+            ByteBuf buf = nextReadableBuf(channel);
             if (buf == null) {
                 if (endOfStream) {
-                    return super.writeData(ctx, streamId, Unpooled.EMPTY_BUFFER, padding, endOfStream, promise);
+                    if (channel.finish()) {
+                        buf = nextReadableBuf(channel);
+                    }
+                    return super.writeData(ctx, streamId, buf == null ? Unpooled.EMPTY_BUFFER : buf, padding,
+                            true, promise);
                 }
                 // END_STREAM is not set and the assumption is data is still forthcoming.
                 promise.setSuccess();
@@ -123,23 +128,39 @@ public class CompressorHttp2ConnectionEncoder extends DefaultHttp2ConnectionEnco
             }
 
             ChannelPromiseAggregator aggregator = new ChannelPromiseAggregator(promise);
+            ChannelPromise bufPromise = ctx.newPromise();
+            aggregator.add(bufPromise);
             for (;;) {
-                final ByteBuf nextBuf = nextReadableBuf(compressor);
+                ByteBuf nextBuf = nextReadableBuf(channel);
-                final boolean endOfStreamForBuf = nextBuf == null && endOfStream;
+                boolean compressedEndOfStream = nextBuf == null && endOfStream;
-                ChannelPromise newPromise = ctx.newPromise();
+                if (compressedEndOfStream && channel.finish()) {
-                aggregator.add(newPromise);
+                    nextBuf = nextReadableBuf(channel);
+                    compressedEndOfStream = nextBuf == null;
+                }
 
-                super.writeData(ctx, streamId, buf, padding, endOfStreamForBuf, newPromise);
+                final ChannelPromise nextPromise;
+                if (nextBuf != null) {
+                    // We have to add the nextPromise to the aggregator before doing the current write. This is so
+                    // completing the current write before the next write is done won't complete the aggregate promise
+                    nextPromise = ctx.newPromise();
+                    aggregator.add(nextPromise);
+                } else {
+                    nextPromise = null;
+                }
+
+                super.writeData(ctx, streamId, buf, padding, compressedEndOfStream, bufPromise);
                 if (nextBuf == null) {
                     break;
                 }
 
+                padding = 0; // Padding is only communicated once on the first iteration
                 buf = nextBuf;
+                bufPromise = nextPromise;
             }
             return promise;
         } finally {
             if (endOfStream) {
-                cleanup(stream, compressor);
+                cleanup(stream, channel);
             }
         }
     }
@@ -215,7 +236,7 @@ public class CompressorHttp2ConnectionEncoder extends DefaultHttp2ConnectionEnco
             return;
         }
 
-        EmbeddedChannel compressor = stream.compressor();
+        EmbeddedChannel compressor = stream.getProperty(CompressorHttp2ConnectionEncoder.class);
         if (compressor == null) {
             if (!endOfStream) {
                 AsciiString encoding = headers.get(CONTENT_ENCODING);
@@ -225,6 +246,7 @@ public class CompressorHttp2ConnectionEncoder extends DefaultHttp2ConnectionEnco
                 try {
                     compressor = newContentCompressor(encoding);
                     if (compressor != null) {
+                        stream.setProperty(CompressorHttp2ConnectionEncoder.class, compressor);
                         AsciiString targetContentEncoding = getTargetContentEncoding(encoding);
                         if (IDENTITY.equalsIgnoreCase(targetContentEncoding)) {
                             headers.remove(CONTENT_ENCODING);
@@ -261,10 +283,11 @@ public class CompressorHttp2ConnectionEncoder extends DefaultHttp2ConnectionEnco
                 if (buf == null) {
                     break;
                 }
+
                 buf.release();
             }
         }
-        stream.compressor(null);
+        stream.removeProperty(CompressorHttp2ConnectionEncoder.class);
     }
 
     /**

codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2Connection.java

@@ -29,7 +29,6 @@ import static io.netty.handler.codec.http2.Http2Stream.State.OPEN;
 import static io.netty.handler.codec.http2.Http2Stream.State.RESERVED_LOCAL;
 import static io.netty.handler.codec.http2.Http2Stream.State.RESERVED_REMOTE;
 import static io.netty.util.internal.ObjectUtil.checkNotNull;
-import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.handler.codec.http2.Http2StreamRemovalPolicy.Action;
 import io.netty.util.collection.IntObjectHashMap;
 import io.netty.util.collection.IntObjectMap;
@@ -37,9 +36,11 @@ import io.netty.util.collection.IntObjectMap;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 /**
@@ -217,14 +218,14 @@ public class DefaultHttp2Connection implements Http2Connection {
         private boolean resetReceived;
         private boolean endOfStreamSent;
         private boolean endOfStreamReceived;
-        private Http2InboundFlowState inboundFlow;
+        private Http2FlowState inboundFlow;
         private Http2FlowState outboundFlow;
-        private EmbeddedChannel decompressor;
+        private Http2FlowControlWindowManager garbageCollector;
-        private EmbeddedChannel compressor;
+        private PropertyMap data;
-        private Object data;
 
         DefaultStream(int id) {
             this.id = id;
+            data = new LazyPropertyMap(this);
         }
 
         @Override
@@ -287,49 +288,27 @@ public class DefaultHttp2Connection implements Http2Connection {
         }
 
         @Override
-        public void data(Object data) {
+        public Object setProperty(Object key, Object value) {
-            this.data = data;
+            return data.put(key, value);
-        }
-
-        @SuppressWarnings("unchecked")
-        @Override
-        public <T> T data() {
-            return (T) data;
         }
 
         @Override
-        public void decompressor(EmbeddedChannel decompressor) {
+        public <V> V getProperty(Object key) {
-            if (this.decompressor != null && decompressor != null) {
+            return data.get(key);
-                throw new IllegalStateException("decompressor can not be reassigned");
-            }
-            this.decompressor = decompressor;
         }
 
         @Override
-        public EmbeddedChannel decompressor() {
+        public <V> V removeProperty(Object key) {
-            return decompressor;
+            return data.remove(key);
         }
 
         @Override
-        public void compressor(EmbeddedChannel compressor) {
+        public Http2FlowState inboundFlow() {
-            if (this.compressor != null && compressor != null) {
-                throw new IllegalStateException("compressor can not be reassigned");
-            }
-            this.compressor = compressor;
-        }
-
-        @Override
-        public EmbeddedChannel compressor() {
-            return compressor;
-        }
-
-        @Override
-        public Http2InboundFlowState inboundFlow() {
             return inboundFlow;
         }
 
         @Override
-        public void inboundFlow(Http2InboundFlowState state) {
+        public void inboundFlow(Http2FlowState state) {
             inboundFlow = state;
         }
 
@@ -343,6 +322,16 @@ public class DefaultHttp2Connection implements Http2Connection {
             outboundFlow = state;
         }
 
+        @Override
+        public Http2FlowControlWindowManager garbageCollector() {
+            return garbageCollector;
+        }
+
+        @Override
+        public void garbageCollector(Http2FlowControlWindowManager collector) {
+            garbageCollector = collector;
+        }
+
         @Override
         public final boolean isRoot() {
             return parent == null;
@@ -597,6 +586,75 @@ public class DefaultHttp2Connection implements Http2Connection {
         }
     }
 
+    /**
+     * Allows the data map to be lazily initialized for {@link DefaultStream}.
+     */
+    private interface PropertyMap {
+        Object put(Object key, Object value);
+
+        <V> V get(Object key);
+
+        <V> V remove(Object key);
+    }
+
+    /**
+     * Provides actual {@link HashMap} functionality for {@link DefaultStream}'s application data.
+     */
+    private static final class DefaultProperyMap implements PropertyMap {
+        private final Map<Object, Object> data;
+
+        DefaultProperyMap(int initialSize) {
+            data = new HashMap<Object, Object>(initialSize);
+        }
+
+        @Override
+        public Object put(Object key, Object value) {
+            return data.put(key, value);
+        }
+
+        @SuppressWarnings("unchecked")
+        @Override
+        public <V> V get(Object key) {
+            return (V) data.get(key);
+        }
+
+        @SuppressWarnings("unchecked")
+        @Override
+        public <V> V remove(Object key) {
+            return (V) data.remove(key);
+        }
+    }
+
+    /**
+     * Provides the lazy initialization for the {@link DefaultStream} data map.
+     */
+    private static final class LazyPropertyMap implements PropertyMap {
+        private static final int DEFAULT_INITIAL_SIZE = 4;
+        private final DefaultStream stream;
+
+        LazyPropertyMap(DefaultStream stream) {
+            this.stream = stream;
+        }
+
+        @Override
+        public Object put(Object key, Object value) {
+            stream.data = new DefaultProperyMap(DEFAULT_INITIAL_SIZE);
+            return stream.data.put(key, value);
+        }
+
+        @Override
+        public <V> V get(Object key) {
+            stream.data = new DefaultProperyMap(DEFAULT_INITIAL_SIZE);
+            return stream.data.get(key);
+        }
+
+        @Override
+        public <V> V remove(Object key) {
+            stream.data = new DefaultProperyMap(DEFAULT_INITIAL_SIZE);
+            return stream.data.remove(key);
+        }
+    }
+
     private static IntObjectMap<DefaultStream> newChildMap() {
         return new IntObjectHashMap<DefaultStream>(4);
     }
@@ -604,7 +662,7 @@ public class DefaultHttp2Connection implements Http2Connection {
     /**
      * Allows a correlation to be made between a stream and its old parent before a parent change occurs
      */
-    private final class ParentChangedEvent {
+    private static final class ParentChangedEvent {
         private final Http2Stream stream;
         private final Http2Stream oldParent;
 

codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2ConnectionDecoder.java

@@ -66,6 +66,11 @@ public class DefaultHttp2ConnectionDecoder implements Http2ConnectionDecoder {
             return this;
         }
 
+        @Override
+        public Http2LifecycleManager lifecycleManager() {
+            return lifecycleManager;
+        }
+
         @Override
         public Builder inboundFlow(Http2InboundFlowController inboundFlow) {
             this.inboundFlow = inboundFlow;
@@ -193,7 +198,7 @@ public class DefaultHttp2ConnectionDecoder implements Http2ConnectionDecoder {
     }
 
     private static int unprocessedBytes(Http2Stream stream) {
-        return stream.inboundFlow().unProcessedBytes();
+        return stream.garbageCollector().unProcessedBytes();
     }
 
     /**
@@ -284,7 +289,7 @@ public class DefaultHttp2ConnectionDecoder implements Http2ConnectionDecoder {
             } finally {
                 // If appropriate, returned the processed bytes to the flow controller.
                 if (shouldApplyFlowControl && bytesToReturn > 0) {
-                    stream.inboundFlow().returnProcessedBytes(ctx, bytesToReturn);
+                    stream.garbageCollector().returnProcessedBytes(ctx, bytesToReturn);
                 }
 
                 if (endOfStream) {

codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2ConnectionEncoder.java

@@ -60,6 +60,11 @@ public class DefaultHttp2ConnectionEncoder implements Http2ConnectionEncoder {
             return this;
         }
 
+        @Override
+        public Http2LifecycleManager lifecycleManager() {
+            return lifecycleManager;
+        }
+
         @Override
         public Builder frameWriter(
                 Http2FrameWriter frameWriter) {

codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2InboundFlowController.java

@@ -60,13 +60,18 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
         this.windowUpdateRatio = windowUpdateRatio;
 
         // Add a flow state for the connection.
-        connection.connectionStream().inboundFlow(new FlowState(CONNECTION_STREAM_ID));
+        final Http2Stream connectionStream = connection.connectionStream();
+        final FlowState connectionFlowState = new FlowState(connectionStream);
+        connectionStream.inboundFlow(connectionFlowState);
+        connectionStream.garbageCollector(connectionFlowState);
 
         // Register for notification of new streams.
         connection.addListener(new Http2ConnectionAdapter() {
             @Override
             public void streamAdded(Http2Stream stream) {
-                stream.inboundFlow(new FlowState(stream.id()));
+                final FlowState flowState = new FlowState(stream);
+                stream.inboundFlow(flowState);
+                stream.garbageCollector(flowState);
             }
         });
     }
@@ -141,8 +146,8 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
     /**
      * Flow control window state for an individual stream.
      */
-    private final class FlowState implements Http2InboundFlowState {
+    private final class FlowState implements Http2FlowState, Http2FlowControlWindowManager {
-        private final int streamId;
+        private final Http2Stream stream;
 
         /**
          * The actual flow control window that is decremented as soon as {@code DATA} arrives.
@@ -160,8 +165,8 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
         private int lowerBound;
         private boolean endOfStream;
 
-        FlowState(int streamId) {
+        FlowState(Http2Stream stream) {
-            this.streamId = streamId;
+            this.stream = stream;
             window = initialWindowSize;
             processedWindow = window;
         }
@@ -180,7 +185,7 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
          */
         int initialWindowSize() {
             int maxWindowSize = initialWindowSize;
-            if (streamId == CONNECTION_STREAM_ID) {
+            if (stream.id() == CONNECTION_STREAM_ID) {
                 // Determine the maximum number of streams that we can allow without integer overflow
                 // of maxWindowSize * numStreams. Also take care to avoid division by zero when
                 // maxWindowSize == 0.
@@ -196,7 +201,7 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
 
         @Override
         public void returnProcessedBytes(ChannelHandlerContext ctx, int numBytes) throws Http2Exception {
-            if (streamId == CONNECTION_STREAM_ID) {
+            if (stream.id() == CONNECTION_STREAM_ID) {
                 throw new UnsupportedOperationException("Returning bytes for the connection window is not supported");
             }
             checkNotNull(ctx, "ctx");
@@ -214,6 +219,11 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
             return processedWindow - window;
         }
 
+        @Override
+        public Http2Stream stream() {
+            return stream;
+        }
+
         /**
          * Updates the flow control window for this stream if it is appropriate.
          */
@@ -233,13 +243,12 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
          */
         void returnProcessedBytes(int delta) throws Http2Exception {
             if (processedWindow - delta < window) {
-                if (streamId == CONNECTION_STREAM_ID) {
+                if (stream.id() == CONNECTION_STREAM_ID) {
                     throw new Http2Exception(INTERNAL_ERROR,
                             "Attempting to return too many bytes for connection");
-                } else {
-                    throw new Http2StreamException(streamId, INTERNAL_ERROR,
-                            "Attempting to return too many bytes for stream " + streamId);
                 }
+                throw new Http2StreamException(stream.id(), INTERNAL_ERROR,
+                        "Attempting to return too many bytes for stream " + stream.id());
             }
             processedWindow -= delta;
         }
@@ -264,10 +273,10 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
             // This difference is stored for the connection when writing the SETTINGS frame
             // and is cleared once we send a WINDOW_UPDATE frame.
             if (delta < 0 && window < lowerBound) {
-                if (streamId == CONNECTION_STREAM_ID) {
+                if (stream.id() == CONNECTION_STREAM_ID) {
                     throw protocolError("Connection flow control window exceeded");
                 } else {
-                    throw flowControlError("Flow control window exceeded for stream: %d", streamId);
+                    throw flowControlError("Flow control window exceeded for stream: %d", stream.id());
                 }
             }
 
@@ -286,7 +295,7 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
         void updatedInitialWindowSize(int delta) throws Http2Exception {
             if (delta > 0 && window > Integer.MAX_VALUE - delta) {
                 // Integer overflow.
-                throw flowControlError("Flow control window overflowed for stream: %d", streamId);
+                throw flowControlError("Flow control window overflowed for stream: %d", stream.id());
             }
             window += delta;
             processedWindow += delta;
@@ -314,7 +323,7 @@ public class DefaultHttp2InboundFlowController implements Http2InboundFlowContro
             }
 
             // Send a window update for the stream/connection.
-            frameWriter.writeWindowUpdate(ctx, streamId, deltaWindowSize, ctx.newPromise());
+            frameWriter.writeWindowUpdate(ctx, stream.id(), deltaWindowSize, ctx.newPromise());
             ctx.flush();
         }
     }

codec-http2/src/main/java/io/netty/handler/codec/http2/DelegatingDecompressorFrameListener.java

@@ -29,6 +29,7 @@ import io.netty.handler.codec.AsciiString;
 import io.netty.handler.codec.ByteToMessageDecoder;
 import io.netty.handler.codec.compression.ZlibCodecFactory;
 import io.netty.handler.codec.compression.ZlibWrapper;
+import io.netty.util.CharsetUtil;
 
 /**
  * A HTTP2 frame listener that will decompress data frames according to the {@code content-encoding} header for each
@@ -38,7 +39,7 @@ public class DelegatingDecompressorFrameListener extends Http2FrameListenerDecor
     private static final Http2ConnectionAdapter CLEAN_UP_LISTENER = new Http2ConnectionAdapter() {
         @Override
         public void streamRemoved(Http2Stream stream) {
-            final EmbeddedChannel decompressor = stream.decompressor();
+            final Http2Decompressor decompressor = stream.getProperty(Http2Decompressor.class);
             if (decompressor != null) {
                 cleanup(stream, decompressor);
             }
@@ -63,47 +64,59 @@ public class DelegatingDecompressorFrameListener extends Http2FrameListenerDecor
 
     @Override
     public int onDataRead(ChannelHandlerContext ctx, int streamId, ByteBuf data, int padding, boolean endOfStream)
-                    throws Http2Exception {
+            throws Http2Exception {
         final Http2Stream stream = connection.stream(streamId);
-        final EmbeddedChannel decompressor = stream == null ? null : stream.decompressor();
+        final Http2Decompressor decompressor = stream == null ? null :
+            (Http2Decompressor) stream.getProperty(Http2Decompressor.class);
         if (decompressor == null) {
             // The decompressor may be null if no compatible encoding type was found in this stream's headers
             return listener.onDataRead(ctx, streamId, data, padding, endOfStream);
         }
 
-        // When decompressing, always opt-out of application-level flow control.
+        final EmbeddedChannel channel = decompressor.decompressor();
-        // TODO: investigate how to apply application-level flow control when decompressing.
+        final int compressedBytes = data.readableBytes() + padding;
-        int processedBytes = data.readableBytes() + padding;
+        int processedBytes = 0;
-        try {
+        decompressor.incrementCompressedBytes(compressedBytes);
-            // call retain here as it will call release after its written to the channel
+        // call retain here as it will call release after its written to the channel
-            decompressor.writeInbound(data.retain());
+        channel.writeInbound(data.retain());
-            ByteBuf buf = nextReadableBuf(decompressor);
+        ByteBuf buf = nextReadableBuf(channel);
-            if (buf == null) {
+        if (buf == null && endOfStream && channel.finish()) {
-                if (endOfStream) {
+            buf = nextReadableBuf(channel);
-                    listener.onDataRead(ctx, streamId, Unpooled.EMPTY_BUFFER, padding, true);
+        }
-                }
+        if (buf == null) {
-                // END_STREAM is not set and the data could not be decoded yet.
-                // The assumption has to be there will be more data frames to complete the decode.
-                // We don't have enough information here to know if this is an error.
-            } else {
-                for (;;) {
-                    final ByteBuf nextBuf = nextReadableBuf(decompressor);
-                    final boolean endOfStreamForBuf = nextBuf == null && endOfStream;
-
-                    listener.onDataRead(ctx, streamId, buf, padding, endOfStreamForBuf);
-                    if (nextBuf == null) {
-                        break;
-                    }
-
-                    buf = nextBuf;
-                }
-            }
-            return processedBytes;
-        } finally {
             if (endOfStream) {
-                cleanup(stream, decompressor);
+                listener.onDataRead(ctx, streamId, Unpooled.EMPTY_BUFFER, padding, true);
+            }
+            // No new decompressed data was extracted from the compressed data. This means the application could not be
+            // provided with data and thus could not return how many bytes were processed. We will assume there is more
+            // data coming which will complete the decompression block. To allow for more data we return all bytes to
+            // the flow control window (so the peer can send more data).
+            decompressor.incrementDecompressedByes(compressedBytes);
+            processedBytes = compressedBytes;
+        } else {
+            decompressor.incrementDecompressedByes(padding);
+            for (;;) {
+                ByteBuf nextBuf = nextReadableBuf(channel);
+                boolean decompressedEndOfStream = nextBuf == null && endOfStream;
+                if (decompressedEndOfStream && channel.finish()) {
+                    nextBuf = nextReadableBuf(channel);
+                    decompressedEndOfStream = nextBuf == null;
+                }
+
+                decompressor.incrementDecompressedByes(buf.readableBytes());
+                processedBytes += listener.onDataRead(ctx, streamId, buf, padding, decompressedEndOfStream);
+                if (nextBuf == null) {
+                    break;
+                }
+
+                padding = 0; // Padding is only communicated once on the first iteration
+                buf = nextBuf;
             }
         }
+
+        decompressor.incrementProcessedBytes(processedBytes);
+        // The processed bytes will be translated to pre-decompressed byte amounts by DecompressorGarbageCollector
+        return processedBytes;
     }
 
     @Override
@@ -172,29 +185,27 @@ public class DelegatingDecompressorFrameListener extends Http2FrameListenerDecor
             return;
         }
 
-        EmbeddedChannel decompressor = stream.decompressor();
+        Http2Decompressor decompressor = stream.getProperty(Http2Decompressor.class);
-        if (decompressor == null) {
+        if (decompressor == null && !endOfStream) {
-            if (!endOfStream) {
+            // Determine the content encoding.
-                // Determine the content encoding.
+            AsciiString contentEncoding = headers.get(CONTENT_ENCODING);
-                AsciiString contentEncoding = headers.get(CONTENT_ENCODING);
+            if (contentEncoding == null) {
-                if (contentEncoding == null) {
+                contentEncoding = IDENTITY;
-                    contentEncoding = IDENTITY;
+            }
-                }
+            final EmbeddedChannel channel = newContentDecompressor(contentEncoding);
-                decompressor = newContentDecompressor(contentEncoding);
+            if (channel != null) {
-                if (decompressor != null) {
+                decompressor = new Http2Decompressor(channel);
-                    stream.decompressor(decompressor);
+                stream.setProperty(Http2Decompressor.class, decompressor);
-                    // Decode the content and remove or replace the existing headers
+                stream.garbageCollector(new DecompressorGarbageCollector(stream.garbageCollector()));
-                    // so that the message looks like a decoded message.
+                // Decode the content and remove or replace the existing headers
-                    AsciiString targetContentEncoding = getTargetContentEncoding(contentEncoding);
+                // so that the message looks like a decoded message.
-                    if (IDENTITY.equalsIgnoreCase(targetContentEncoding)) {
+                AsciiString targetContentEncoding = getTargetContentEncoding(contentEncoding);
-                        headers.remove(CONTENT_ENCODING);
+                if (IDENTITY.equalsIgnoreCase(targetContentEncoding)) {
-                    } else {
+                    headers.remove(CONTENT_ENCODING);
-                        headers.set(CONTENT_ENCODING, targetContentEncoding);
+                } else {
-                    }
+                    headers.set(CONTENT_ENCODING, targetContentEncoding);
                 }
             }
-        } else if (endOfStream) {
-            cleanup(stream, decompressor);
         }
 
         if (decompressor != null) {
@@ -212,17 +223,22 @@ public class DelegatingDecompressorFrameListener extends Http2FrameListenerDecor
      * @param stream The stream for which {@code decompressor} is the decompressor for
      * @param decompressor The decompressor for {@code stream}
      */
-    private static void cleanup(Http2Stream stream, EmbeddedChannel decompressor) {
+    private static void cleanup(Http2Stream stream, Http2Decompressor decompressor) {
-        if (decompressor.finish()) {
+        final EmbeddedChannel channel = decompressor.decompressor();
+        if (channel.finish()) {
             for (;;) {
-                final ByteBuf buf = decompressor.readInbound();
+                final ByteBuf buf = channel.readInbound();
                 if (buf == null) {
                     break;
                 }
                 buf.release();
             }
         }
-        stream.decompressor(null);
+        decompressor = stream.removeProperty(Http2Decompressor.class);
+        if (decompressor != null) {
+            DecompressorGarbageCollector gc = (DecompressorGarbageCollector) stream.garbageCollector();
+            stream.garbageCollector(gc.original());
+        }
     }
 
     /**
@@ -245,4 +261,128 @@ public class DelegatingDecompressorFrameListener extends Http2FrameListenerDecor
             return buf;
         }
     }
+
+    /**
+     * Garbage collector which translates post-decompression amounts the application knows about
+     * to pre-decompression amounts that flow control knows about.
+     */
+    private static final class DecompressorGarbageCollector implements Http2FlowControlWindowManager {
+        private final Http2FlowControlWindowManager original;
+
+        DecompressorGarbageCollector(Http2FlowControlWindowManager original) {
+            this.original = original;
+        }
+
+        @Override
+        public void returnProcessedBytes(ChannelHandlerContext ctx, int numBytes) throws Http2Exception {
+            final Http2Stream stream = stream();
+            final Http2Decompressor decompressor = stream.getProperty(Http2Decompressor.class);
+
+            // Make a copy before hand in case any exceptions occur we will roll back the state
+            Http2Decompressor copy = new Http2Decompressor(decompressor);
+            try {
+                original.returnProcessedBytes(ctx, decompressor.consumeProcessedBytes(numBytes));
+            } catch (Http2Exception e) {
+                stream.setProperty(Http2Decompressor.class, copy);
+                throw e;
+            } catch (Throwable t) {
+                stream.setProperty(Http2Decompressor.class, copy);
+                throw new Http2Exception(Http2Error.INTERNAL_ERROR,
+                        "Error while returning bytes to flow control window", t);
+            }
+        }
+
+        Http2FlowControlWindowManager original() {
+            return original;
+        }
+
+        @Override
+        public int unProcessedBytes() {
+            return original.unProcessedBytes();
+        }
+
+        @Override
+        public Http2Stream stream() {
+            return original.stream();
+        }
+    }
+
+    /**
+     * Provides the state for stream {@code DATA} frame decompression.
+     */
+    private static final class Http2Decompressor {
+        private final EmbeddedChannel decompressor;
+        private int processed;
+        private int compressed;
+        private int decompressed;
+
+        Http2Decompressor(Http2Decompressor rhs) {
+            this(rhs.decompressor);
+            processed = rhs.processed;
+            compressed = rhs.compressed;
+            decompressed = rhs.decompressed;
+        }
+
+        Http2Decompressor(EmbeddedChannel decompressor) {
+            this.decompressor = decompressor;
+        }
+
+        /**
+         * Responsible for taking compressed bytes in and producing decompressed bytes.
+         */
+        EmbeddedChannel decompressor() {
+            return decompressor;
+        }
+
+        /**
+         * Increment the number of decompressed bytes processed by the application.
+         */
+        void incrementProcessedBytes(int delta) {
+            if (processed + delta < 0) {
+                throw new IllegalArgumentException("processed bytes cannot be negative");
+            }
+            processed += delta;
+        }
+
+        /**
+         * Increment the number of bytes received prior to doing any decompression.
+         */
+        void incrementCompressedBytes(int delta) {
+            if (compressed + delta < 0) {
+                throw new IllegalArgumentException("compressed bytes cannot be negative");
+            }
+            compressed += delta;
+        }
+
+        /**
+         * Increment the number of bytes after the decompression process. Under normal circumstances this
+         * delta should not exceed {@link Http2Decompressor#processedBytes()}.
+         */
+        void incrementDecompressedByes(int delta) {
+            if (decompressed + delta < 0) {
+                throw new IllegalArgumentException("decompressed bytes cannot be negative");
+            }
+            decompressed += delta;
+        }
+
+        /**
+         * Decrements {@link Http2Decompressor#processedBytes()} by {@code processedBytes} and determines the ratio
+         * between {@code processedBytes} and {@link Http2Decompressor#decompressedBytes()}.
+         * This ratio is used to decrement {@link Http2Decompressor#decompressedBytes()} and
+         * {@link Http2Decompressor#compressedBytes()}.
+         * @param processedBytes The number of post-decompressed bytes that have been processed.
+         * @return The number of pre-decompressed bytes that have been consumed.
+         */
+        int consumeProcessedBytes(int processedBytes) {
+            // Consume the processed bytes first to verify that is is a valid amount
+            incrementProcessedBytes(-processedBytes);
+
+            double consumedRatio = processedBytes / (double) decompressed;
+            int consumedCompressed = Math.min(compressed, (int) Math.ceil(compressed * consumedRatio));
+            incrementDecompressedByes(-Math.min(decompressed, (int) Math.ceil(decompressed * consumedRatio)));
+            incrementCompressedBytes(-consumedCompressed);
+
+            return consumedCompressed;
+        }
+    }
 }

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2ConnectionDecoder.java

@@ -43,6 +43,11 @@ public interface Http2ConnectionDecoder extends Closeable {
          */
         Builder lifecycleManager(Http2LifecycleManager lifecycleManager);
 
+        /**
+         * Gets the {@link Http2LifecycleManager} to be used when building the decoder.
+         */
+        Http2LifecycleManager lifecycleManager();
+
         /**
          * Sets the {@link Http2InboundFlowController} to be used when building the decoder.
          */

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2ConnectionEncoder.java

@@ -40,6 +40,11 @@ public interface Http2ConnectionEncoder extends Http2FrameWriter, Http2OutboundF
          */
         Builder lifecycleManager(Http2LifecycleManager lifecycleManager);
 
+        /**
+         * Gets the {@link Http2LifecycleManager} to be used when building the encoder.
+         */
+        Http2LifecycleManager lifecycleManager();
+
         /**
          * Sets the {@link Http2FrameWriter} to be used when building the encoder.
          */

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2ConnectionHandler.java

@@ -79,13 +79,18 @@ public class Http2ConnectionHandler extends ByteToMessageDecoder implements Http
         checkNotNull(decoderBuilder, "decoderBuilder");
         checkNotNull(encoderBuilder, "encoderBuilder");
 
+        if (encoderBuilder.lifecycleManager() != decoderBuilder.lifecycleManager()) {
+            throw new IllegalArgumentException("Encoder and Decoder must share a lifecycle manager");
+        } else if (encoderBuilder.lifecycleManager() == null) {
+            encoderBuilder.lifecycleManager(this);
+            decoderBuilder.lifecycleManager(this);
+        }
+
         // Build the encoder.
-        encoderBuilder.lifecycleManager(this);
         encoder = checkNotNull(encoderBuilder.build(), "encoder");
 
         // Build the decoder.
         decoderBuilder.encoder(encoder);
-        decoderBuilder.lifecycleManager(this);
         decoder = checkNotNull(decoderBuilder.build(), "decoder");
 
         // Verify that the encoder and decoder use the same connection.
@@ -146,8 +151,7 @@ public class Http2ConnectionHandler extends ByteToMessageDecoder implements Http
 
     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
-        // The channel just became active - send the connection preface to the remote
+        // The channel just became active - send the connection preface to the remote endpoint.
-        // endpoint.
         sendPreface(ctx);
         super.channelActive(ctx);
     }
@@ -166,7 +170,7 @@ public class Http2ConnectionHandler extends ByteToMessageDecoder implements Http
 
     @Override
     public void close(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception {
-     // Avoid NotYetConnectedException
+        // Avoid NotYetConnectedException
         if (!ctx.channel().isActive()) {
             ctx.close(promise);
             return;

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2FlowControlWindowManager.java

@@ -17,11 +17,9 @@ package io.netty.handler.codec.http2;
 import io.netty.channel.ChannelHandlerContext;
 
 /**
- * The inbound flow control state for a stream. This object is created and managed by the
+ * Allows data to be returned to the flow control window.
- * {@link Http2InboundFlowController}.
  */
-public interface Http2InboundFlowState extends Http2FlowState {
+public interface Http2FlowControlWindowManager {
-
     /**
      * Used by applications that participate in application-level inbound flow control. Allows the
      * application to return a number of bytes that has been processed and thereby enabling the
@@ -38,4 +36,9 @@ public interface Http2InboundFlowState extends Http2FlowState {
      * The number of bytes that are outstanding and have not yet been returned to the flow controller.
      */
     int unProcessedBytes();
+
+    /**
+     * Get the stream that is being managed
+     */
+    Http2Stream stream();
 }

codec-http2/src/main/java/io/netty/handler/codec/http2/Http2Stream.java

@@ -15,8 +15,6 @@
 
 package io.netty.handler.codec.http2;
 
-import io.netty.channel.embedded.EmbeddedChannel;
-
 import java.util.Collection;
 
 /**
@@ -135,43 +133,29 @@ public interface Http2Stream {
 
     /**
      * Associates the application-defined data with this stream.
+     * @return The value that was previously associated with {@code key}, or {@code null} if there was none.
      */
-    void data(Object data);
+    Object setProperty(Object key, Object value);
 
     /**
      * Returns application-defined data if any was associated with this stream.
      */
-    <T> T data();
+    <V> V getProperty(Object key);
 
     /**
-     * Associate an object responsible for decompressing data frames for this stream
+     * Returns and removes application-defined data if any was associated with this stream.
      */
-    void decompressor(EmbeddedChannel decompressor);
+    <V> V removeProperty(Object key);
-
-    /**
-     * Get the object capable of decompressing data frames for this stream
-     */
-    EmbeddedChannel decompressor();
-
-    /**
-     * Associate an object responsible for compressing data frames for this stream
-     */
-    void compressor(EmbeddedChannel decompressor);
-
-    /**
-     * Get the object capable of compressing data frames for this stream
-     */
-    EmbeddedChannel compressor();
 
     /**
      * Gets the in-bound flow control state for this stream.
      */
-    Http2InboundFlowState inboundFlow();
+    Http2FlowState inboundFlow();
 
     /**
      * Sets the in-bound flow control state for this stream.
      */
-    void inboundFlow(Http2InboundFlowState state);
+    void inboundFlow(Http2FlowState state);
 
     /**
      * Gets the out-bound flow control window for this stream.
@@ -183,6 +167,16 @@ public interface Http2Stream {
      */
     void outboundFlow(Http2FlowState state);
 
+    /**
+     * Gets the interface which allows bytes to be returned to the flow controller
+     */
+    Http2FlowControlWindowManager garbageCollector();
+
+    /**
+     * Sets the interface which allows bytes to be returned to the flow controller
+     */
+    void garbageCollector(Http2FlowControlWindowManager collector);
+
     /**
      * Updates an priority for this stream. Calling this method may affect the straucture of the
      * priority tree.

codec-http2/src/test/java/io/netty/handler/codec/http2/DataCompressionHttp2Test.java

@@ -19,47 +19,50 @@ import static io.netty.handler.codec.http2.Http2TestUtil.as;
 import static io.netty.handler.codec.http2.Http2TestUtil.runInChannel;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyBoolean;
+import static org.mockito.Matchers.anyInt;
 import static org.mockito.Matchers.eq;
-import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.verify;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.bootstrap.ServerBootstrap;
 import io.netty.buffer.ByteBuf;
-import io.netty.buffer.ByteBufAllocator;
 import io.netty.buffer.Unpooled;
-import io.netty.buffer.UnpooledByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.ChannelPromise;
-import io.netty.channel.embedded.EmbeddedChannel;
 import io.netty.channel.nio.NioEventLoopGroup;
 import io.netty.channel.socket.nio.NioServerSocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.codec.AsciiString;
-import io.netty.handler.codec.compression.ZlibCodecFactory;
-import io.netty.handler.codec.compression.ZlibWrapper;
 import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaderValues;
 import io.netty.handler.codec.http2.Http2TestUtil.FrameAdapter;
+import io.netty.handler.codec.http2.Http2TestUtil.FrameCountDown;
 import io.netty.handler.codec.http2.Http2TestUtil.Http2Runnable;
+import io.netty.util.CharsetUtil;
 import io.netty.util.NetUtil;
 import io.netty.util.concurrent.Future;
 
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
 import java.net.InetSocketAddress;
-import java.util.List;
+import java.util.Random;
 import java.util.concurrent.CountDownLatch;
 
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.mockito.ArgumentCaptor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
 
 /**
  * Test for data decompression in the HTTP/2 codec.
@@ -68,18 +71,12 @@ public class DataCompressionHttp2Test {
     private static final AsciiString GET = as("GET");
     private static final AsciiString POST = as("POST");
     private static final AsciiString PATH = as("/some/path");
-    private List<ByteBuf> dataCapture;
 
     @Mock
     private Http2FrameListener serverListener;
     @Mock
     private Http2FrameListener clientListener;
-    @Mock
-    private Http2LifecycleManager serverLifeCycleManager;
-    @Mock
-    private Http2LifecycleManager clientLifeCycleManager;
 
-    private ByteBufAllocator alloc;
     private Http2ConnectionEncoder serverEncoder;
     private Http2ConnectionEncoder clientEncoder;
     private ServerBootstrap sb;
@@ -89,23 +86,22 @@ public class DataCompressionHttp2Test {
     private Channel clientChannel;
     private volatile CountDownLatch serverLatch;
     private volatile CountDownLatch clientLatch;
-    private FrameAdapter serverAdapter;
-    private FrameAdapter clientAdapter;
     private Http2Connection serverConnection;
+    private Http2Connection clientConnection;
+    private ByteArrayOutputStream serverOut;
 
     @Before
     public void setup() throws InterruptedException {
         MockitoAnnotations.initMocks(this);
     }
 
+    @After
+    public void cleaup() throws IOException {
+        serverOut.close();
+    }
+
     @After
     public void teardown() throws InterruptedException {
-        if (dataCapture != null) {
-            for (int i = 0; i < dataCapture.size(); ++i) {
-                dataCapture.get(i).release();
-            }
-            dataCapture = null;
-        }
         serverChannel.close().sync();
         Future<?> serverGroup = sb.group().shutdownGracefully(0, 0, MILLISECONDS);
         Future<?> serverChildGroup = sb.childGroup().shutdownGracefully(0, 0, MILLISECONDS);
@@ -113,19 +109,18 @@ public class DataCompressionHttp2Test {
         serverGroup.sync();
         serverChildGroup.sync();
         clientGroup.sync();
-        serverAdapter = null;
-        clientAdapter = null;
-        serverConnection = null;
     }
 
     @Test
     public void justHeadersNoData() throws Exception {
-        bootstrapEnv(1, 1);
+        bootstrapEnv(1, 0, 1);
         final Http2Headers headers = new DefaultHttp2Headers().method(GET).path(PATH)
                 .set(HttpHeaderNames.CONTENT_ENCODING, HttpHeaderValues.GZIP);
+
         // Required because the decompressor intercepts the onXXXRead events before
         // our {@link Http2TestUtil$FrameAdapter} does.
         FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+        FrameAdapter.getOrCreateStream(clientConnection, 3, false);
         runInChannel(clientChannel, new Http2Runnable() {
             @Override
             public void run() {
@@ -140,131 +135,109 @@ public class DataCompressionHttp2Test {
 
     @Test
     public void gzipEncodingSingleEmptyMessage() throws Exception {
-        bootstrapEnv(2, 1);
         final String text = "";
         final ByteBuf data = Unpooled.copiedBuffer(text.getBytes());
-        final EmbeddedChannel encoder = new EmbeddedChannel(ZlibCodecFactory.newZlibEncoder(ZlibWrapper.GZIP));
+        bootstrapEnv(1, data.readableBytes(), 1);
         try {
-            final ByteBuf encodedData = encodeData(data, encoder);
             final Http2Headers headers = new DefaultHttp2Headers().method(POST).path(PATH)
                     .set(HttpHeaderNames.CONTENT_ENCODING, HttpHeaderValues.GZIP);
+
             // Required because the decompressor intercepts the onXXXRead events before
             // our {@link Http2TestUtil$FrameAdapter} does.
-            FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            Http2Stream stream = FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            FrameAdapter.getOrCreateStream(clientConnection, 3, false);
             runInChannel(clientChannel, new Http2Runnable() {
                 @Override
                 public void run() {
                     clientEncoder.writeHeaders(ctxClient(), 3, headers, 0, false, newPromiseClient());
-                    clientEncoder.writeData(ctxClient(), 3, encodedData, 0, true, newPromiseClient());
+                    clientEncoder.writeData(ctxClient(), 3, data, 0, true, newPromiseClient());
                     ctxClient().flush();
                 }
             });
             awaitServer();
-            data.resetReaderIndex();
+            assertEquals(0, stream.garbageCollector().unProcessedBytes());
-            ArgumentCaptor<ByteBuf> dataCaptor = ArgumentCaptor.forClass(ByteBuf.class);
+            assertEquals(text, serverOut.toString(CharsetUtil.UTF_8.name()));
-            verify(serverListener).onDataRead(any(ChannelHandlerContext.class), eq(3), dataCaptor.capture(), eq(0),
-                    eq(true));
-            dataCapture = dataCaptor.getAllValues();
-            assertEquals(data, dataCapture.get(0));
         } finally {
             data.release();
-            cleanupEncoder(encoder);
         }
     }
 
     @Test
     public void gzipEncodingSingleMessage() throws Exception {
-        bootstrapEnv(2, 1);
         final String text = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbbbbbbbbbbbbbbbbbbbbbbbccccccccccccccccccccccc";
         final ByteBuf data = Unpooled.copiedBuffer(text.getBytes());
-        final EmbeddedChannel encoder = new EmbeddedChannel(ZlibCodecFactory.newZlibEncoder(ZlibWrapper.GZIP));
+        bootstrapEnv(1, data.readableBytes(), 1);
         try {
-            final ByteBuf encodedData = encodeData(data, encoder);
             final Http2Headers headers = new DefaultHttp2Headers().method(POST).path(PATH)
                     .set(HttpHeaderNames.CONTENT_ENCODING, HttpHeaderValues.GZIP);
+
             // Required because the decompressor intercepts the onXXXRead events before
             // our {@link Http2TestUtil$FrameAdapter} does.
-            FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            Http2Stream stream = FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            FrameAdapter.getOrCreateStream(clientConnection, 3, false);
             runInChannel(clientChannel, new Http2Runnable() {
                 @Override
                 public void run() {
                     clientEncoder.writeHeaders(ctxClient(), 3, headers, 0, false, newPromiseClient());
-                    clientEncoder.writeData(ctxClient(), 3, encodedData, 0, true, newPromiseClient());
+                    clientEncoder.writeData(ctxClient(), 3, data, 0, true, newPromiseClient());
                     ctxClient().flush();
                 }
             });
             awaitServer();
-            data.resetReaderIndex();
+            assertEquals(0, stream.garbageCollector().unProcessedBytes());
-            ArgumentCaptor<ByteBuf> dataCaptor = ArgumentCaptor.forClass(ByteBuf.class);
+            assertEquals(text, serverOut.toString(CharsetUtil.UTF_8.name()));
-            verify(serverListener).onDataRead(any(ChannelHandlerContext.class), eq(3), dataCaptor.capture(), eq(0),
-                    eq(true));
-            dataCapture = dataCaptor.getAllValues();
-            assertEquals(data, dataCapture.get(0));
         } finally {
             data.release();
-            cleanupEncoder(encoder);
         }
     }
 
     @Test
     public void gzipEncodingMultipleMessages() throws Exception {
-        bootstrapEnv(3, 1);
         final String text1 = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbbbbbbbbbbbbbbbbbbbbbbbbbbbbccccccccccccccccccccccc";
         final String text2 = "dddddddddddddddddddeeeeeeeeeeeeeeeeeeeffffffffffffffffffff";
         final ByteBuf data1 = Unpooled.copiedBuffer(text1.getBytes());
         final ByteBuf data2 = Unpooled.copiedBuffer(text2.getBytes());
-        final EmbeddedChannel encoder = new EmbeddedChannel(ZlibCodecFactory.newZlibEncoder(ZlibWrapper.GZIP));
+        bootstrapEnv(1, data1.readableBytes() + data2.readableBytes(), 1);
         try {
-            final ByteBuf encodedData1 = encodeData(data1, encoder);
-            final ByteBuf encodedData2 = encodeData(data2, encoder);
             final Http2Headers headers = new DefaultHttp2Headers().method(POST).path(PATH)
                     .set(HttpHeaderNames.CONTENT_ENCODING, HttpHeaderValues.GZIP);
+
             // Required because the decompressor intercepts the onXXXRead events before
             // our {@link Http2TestUtil$FrameAdapter} does.
-            FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            Http2Stream stream = FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            FrameAdapter.getOrCreateStream(clientConnection, 3, false);
             runInChannel(clientChannel, new Http2Runnable() {
                 @Override
                 public void run() {
                     clientEncoder.writeHeaders(ctxClient(), 3, headers, 0, false, newPromiseClient());
-                    clientEncoder.writeData(ctxClient(), 3, encodedData1, 0, false, newPromiseClient());
+                    clientEncoder.writeData(ctxClient(), 3, data1, 0, false, newPromiseClient());
-                    clientEncoder.writeData(ctxClient(), 3, encodedData2, 0, true, newPromiseClient());
+                    clientEncoder.writeData(ctxClient(), 3, data2, 0, true, newPromiseClient());
                     ctxClient().flush();
                 }
             });
             awaitServer();
-            data1.resetReaderIndex();
+            assertEquals(0, stream.garbageCollector().unProcessedBytes());
-            data2.resetReaderIndex();
+            assertEquals(new StringBuilder(text1).append(text2).toString(),
-            ArgumentCaptor<ByteBuf> dataCaptor = ArgumentCaptor.forClass(ByteBuf.class);
+                    serverOut.toString(CharsetUtil.UTF_8.name()));
-            ArgumentCaptor<Boolean> endStreamCaptor = ArgumentCaptor.forClass(Boolean.class);
-            verify(serverListener, times(2)).onDataRead(any(ChannelHandlerContext.class), eq(3), dataCaptor.capture(),
-                    eq(0), endStreamCaptor.capture());
-            dataCapture = dataCaptor.getAllValues();
-            assertEquals(data1, dataCapture.get(0));
-            assertEquals(data2, dataCapture.get(1));
-            List<Boolean> endStreamCapture = endStreamCaptor.getAllValues();
-            assertFalse(endStreamCapture.get(0));
-            assertTrue(endStreamCapture.get(1));
         } finally {
             data1.release();
             data2.release();
-            cleanupEncoder(encoder);
         }
     }
 
     @Test
     public void deflateEncodingSingleLargeMessageReducedWindow() throws Exception {
-        bootstrapEnv(3, 1);
         final int BUFFER_SIZE = 1 << 16;
+        bootstrapEnv(1, BUFFER_SIZE, 1);
         final ByteBuf data = Unpooled.buffer(BUFFER_SIZE);
-        final EmbeddedChannel encoder = new EmbeddedChannel(ZlibCodecFactory.newZlibEncoder(ZlibWrapper.ZLIB));
         try {
             for (int i = 0; i < data.capacity(); ++i) {
                 data.writeByte((byte) 'a');
             }
-            final ByteBuf encodedData = encodeData(data, encoder);
             final Http2Headers headers = new DefaultHttp2Headers().method(POST).path(PATH)
                     .set(HttpHeaderNames.CONTENT_ENCODING, HttpHeaderValues.DEFLATE);
             final Http2Settings settings = new Http2Settings();
+
             // Assume the compression operation will reduce the size by at least 10 bytes
             settings.initialWindowSize(BUFFER_SIZE - 10);
             runInChannel(serverConnectedChannel, new Http2Runnable() {
@@ -278,86 +251,123 @@ public class DataCompressionHttp2Test {
 
             // Required because the decompressor intercepts the onXXXRead events before
             // our {@link Http2TestUtil$FrameAdapter} does.
-            FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            Http2Stream stream = FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            FrameAdapter.getOrCreateStream(clientConnection, 3, false);
             runInChannel(clientChannel, new Http2Runnable() {
                 @Override
                 public void run() {
                     clientEncoder.writeSettings(ctxClient(), settings, newPromiseClient());
                     clientEncoder.writeHeaders(ctxClient(), 3, headers, 0, false, newPromiseClient());
-                    clientEncoder.writeData(ctxClient(), 3, encodedData, 0, true, newPromiseClient());
+                    clientEncoder.writeData(ctxClient(), 3, data, 0, true, newPromiseClient());
                     ctxClient().flush();
                 }
             });
             awaitServer();
-            data.resetReaderIndex();
+            assertEquals(0, stream.garbageCollector().unProcessedBytes());
-            ArgumentCaptor<ByteBuf> dataCaptor = ArgumentCaptor.forClass(ByteBuf.class);
+            assertEquals(data.resetReaderIndex().toString(CharsetUtil.UTF_8),
-            verify(serverListener).onDataRead(any(ChannelHandlerContext.class), eq(3), dataCaptor.capture(), eq(0),
+                    serverOut.toString(CharsetUtil.UTF_8.name()));
-                    eq(true));
-            dataCapture = dataCaptor.getAllValues();
-            assertEquals(data, dataCapture.get(0));
         } finally {
             data.release();
-            cleanupEncoder(encoder);
         }
     }
 
-    private ByteBuf encodeData(ByteBuf data, EmbeddedChannel encoder) {
+    @Test
-        ByteBuf encoded = alloc.buffer(data.readableBytes());
+    public void deflateEncodingMultipleWriteLargeMessageReducedWindow() throws Exception {
-        encoder.writeOutbound(data.retain());
+        final int BUFFER_SIZE = 1 << 12;
-        for (;;) {
+        final byte[] bytes = new byte[BUFFER_SIZE];
-            final ByteBuf buf = encoder.readOutbound();
+        new Random().nextBytes(bytes);
-            if (buf == null) {
+        bootstrapEnv(1, BUFFER_SIZE, 1);
-                break;
+        final ByteBuf data = Unpooled.wrappedBuffer(bytes);
-            }
+        try {
-            if (!buf.isReadable()) {
+            final Http2Headers headers = new DefaultHttp2Headers().method(POST).path(PATH)
-                buf.release();
+                    .set(HttpHeaderNames.CONTENT_ENCODING, HttpHeaderValues.DEFLATE);
-                continue;
+            final Http2Settings settings = new Http2Settings();
-            }
-            encoded.writeBytes(buf);
-            buf.release();
-        }
-        return encoded;
-    }
 
-    private static void cleanupEncoder(EmbeddedChannel encoder) {
+            settings.initialWindowSize(BUFFER_SIZE / 2);
-        if (encoder.finish()) {
+            runInChannel(serverConnectedChannel, new Http2Runnable() {
-            for (;;) {
+                @Override
-                final ByteBuf buf = encoder.readOutbound();
+                public void run() {
-                if (buf == null) {
+                    serverEncoder.writeSettings(ctxServer(), settings, newPromiseServer());
-                    break;
+                    ctxServer().flush();
                 }
-                buf.release();
+            });
-            }
+            awaitClient();
+
+            // Required because the decompressor intercepts the onXXXRead events before
+            // our {@link Http2TestUtil$FrameAdapter} does.
+            Http2Stream stream = FrameAdapter.getOrCreateStream(serverConnection, 3, false);
+            FrameAdapter.getOrCreateStream(clientConnection, 3, false);
+            runInChannel(clientChannel, new Http2Runnable() {
+                @Override
+                public void run() {
+                    clientEncoder.writeSettings(ctxClient(), settings, newPromiseClient());
+                    clientEncoder.writeHeaders(ctxClient(), 3, headers, 0, false, newPromiseClient());
+                    clientEncoder.writeData(ctxClient(), 3, data, 0, true, newPromiseClient());
+                    ctxClient().flush();
+                }
+            });
+            awaitServer();
+            assertEquals(0, stream.garbageCollector().unProcessedBytes());
+            assertEquals(data.resetReaderIndex().toString(CharsetUtil.UTF_8),
+                    serverOut.toString(CharsetUtil.UTF_8.name()));
+        } finally {
+            data.release();
         }
     }
 
-    private void bootstrapEnv(int serverCountDown, int clientCountDown) throws Exception {
+    private void bootstrapEnv(int serverHalfClosedCount, int serverOutSize, int clientCount) throws Exception {
-        alloc = UnpooledByteBufAllocator.DEFAULT;
+        serverOut = new ByteArrayOutputStream(serverOutSize);
+        serverLatch = new CountDownLatch(serverHalfClosedCount);
+        clientLatch = new CountDownLatch(clientCount);
         sb = new ServerBootstrap();
         cb = new Bootstrap();
 
-        serverLatch = new CountDownLatch(serverCountDown);
+        // Streams are created before the normal flow for this test, so these connection must be initialized up front.
-        clientLatch = new CountDownLatch(clientCountDown);
         serverConnection = new DefaultHttp2Connection(true);
+        clientConnection = new DefaultHttp2Connection(false);
 
-        final CountDownLatch latch = new CountDownLatch(1);
+        serverConnection.addListener(new Http2ConnectionAdapter() {
+            @Override
+            public void streamHalfClosed(Http2Stream stream) {
+                serverLatch.countDown();
+            }
+        });
+
+        doAnswer(new Answer<Integer>() {
+            @Override
+            public Integer answer(InvocationOnMock in) throws Throwable {
+                ByteBuf buf = (ByteBuf) in.getArguments()[2];
+                int padding = (Integer) in.getArguments()[3];
+                int processedBytes = buf.readableBytes() + padding;
+
+                buf.readBytes(serverOut, buf.readableBytes());
+                buf.release();
+                return processedBytes;
+            }
+        }).when(serverListener).onDataRead(any(ChannelHandlerContext.class), anyInt(),
+                any(ByteBuf.class), anyInt(), anyBoolean());
+
+        final CountDownLatch serverChannelLatch = new CountDownLatch(1);
         sb.group(new NioEventLoopGroup(), new NioEventLoopGroup());
         sb.channel(NioServerSocketChannel.class);
         sb.childHandler(new ChannelInitializer<Channel>() {
             @Override
             protected void initChannel(Channel ch) throws Exception {
                 ChannelPipeline p = ch.pipeline();
-                CompressorHttp2ConnectionEncoder.Builder builder = new CompressorHttp2ConnectionEncoder.Builder();
                 Http2FrameWriter writer = new DefaultHttp2FrameWriter();
-                serverEncoder = builder.connection(serverConnection).frameWriter(writer)
+                Http2ConnectionHandler connectionHandler = new Http2ConnectionHandler(
-                        .outboundFlow(new DefaultHttp2OutboundFlowController(serverConnection, writer))
+                        new DefaultHttp2ConnectionDecoder.Builder()
-                        .lifecycleManager(serverLifeCycleManager).build();
+                            .connection(serverConnection)
-                serverAdapter = new FrameAdapter(serverConnection, new DelegatingDecompressorFrameListener(
+                            .frameReader(new DefaultHttp2FrameReader())
-                        serverConnection, serverListener), serverLatch);
+                            .inboundFlow(new DefaultHttp2InboundFlowController(serverConnection, writer))
-                p.addLast("reader", serverAdapter);
+                            .listener(new DelegatingDecompressorFrameListener(serverConnection, serverListener)),
-                p.addLast(Http2CodecUtil.ignoreSettingsHandler());
+                        new CompressorHttp2ConnectionEncoder.Builder().connection(serverConnection).frameWriter(writer)
+                                .outboundFlow(new DefaultHttp2OutboundFlowController(serverConnection, writer)));
+                serverEncoder = connectionHandler.encoder();
                 serverConnectedChannel = ch;
-                latch.countDown();
+                p.addLast(connectionHandler);
+                p.addLast(Http2CodecUtil.ignoreSettingsHandler());
+                serverChannelLatch.countDown();
             }
         });
 
@@ -367,14 +377,18 @@ public class DataCompressionHttp2Test {
             @Override
             protected void initChannel(Channel ch) throws Exception {
                 ChannelPipeline p = ch.pipeline();
-                Http2Connection connection = new DefaultHttp2Connection(false);
+                FrameCountDown clientFrameCountDown = new FrameCountDown(clientListener, clientLatch);
                 Http2FrameWriter writer = new DefaultHttp2FrameWriter();
-                CompressorHttp2ConnectionEncoder.Builder builder = new CompressorHttp2ConnectionEncoder.Builder();
+                Http2ConnectionHandler connectionHandler = new Http2ConnectionHandler(
-                clientEncoder = builder.connection(connection).frameWriter(writer)
+                        new DefaultHttp2ConnectionDecoder.Builder()
-                        .outboundFlow(new DefaultHttp2OutboundFlowController(connection, writer))
+                            .connection(clientConnection)
-                        .lifecycleManager(clientLifeCycleManager).build();
+                            .frameReader(new DefaultHttp2FrameReader())
-                clientAdapter = new FrameAdapter(connection, clientListener, clientLatch);
+                            .inboundFlow(new DefaultHttp2InboundFlowController(clientConnection, writer))
-                p.addLast("reader", clientAdapter);
+                            .listener(new DelegatingDecompressorFrameListener(clientConnection, clientFrameCountDown)),
+                        new CompressorHttp2ConnectionEncoder.Builder().connection(clientConnection).frameWriter(writer)
+                                .outboundFlow(new DefaultHttp2OutboundFlowController(clientConnection, writer)));
+                clientEncoder = connectionHandler.encoder();
+                p.addLast(connectionHandler);
                 p.addLast(Http2CodecUtil.ignoreSettingsHandler());
             }
         });
@@ -385,16 +399,16 @@ public class DataCompressionHttp2Test {
         ChannelFuture ccf = cb.connect(new InetSocketAddress(NetUtil.LOCALHOST, port));
         assertTrue(ccf.awaitUninterruptibly().isSuccess());
         clientChannel = ccf.channel();
-
+        assertTrue(serverChannelLatch.await(5, SECONDS));
-        assertTrue(latch.await(5, SECONDS));
     }
 
     private void awaitClient() throws Exception {
-        clientLatch.await(5, SECONDS);
+        assertTrue(clientLatch.await(5, SECONDS));
     }
 
     private void awaitServer() throws Exception {
-        serverLatch.await(5, SECONDS);
+        assertTrue(serverLatch.await(5, SECONDS));
+        serverOut.flush();
     }
 
     private ChannelHandlerContext ctxClient() {

codec-http2/src/test/java/io/netty/handler/codec/http2/DefaultHttp2ConnectionDecoderTest.java

@@ -105,7 +105,7 @@ public class DefaultHttp2ConnectionDecoderTest {
     private Http2ConnectionEncoder encoder;
 
     @Mock
-    private Http2InboundFlowState inFlowState;
+    private Http2FlowControlWindowManager inFlowState;
 
     @Mock
     private Http2LifecycleManager lifecycleManager;
@@ -119,7 +119,7 @@ public class DefaultHttp2ConnectionDecoderTest {
         when(channel.isActive()).thenReturn(true);
         when(stream.id()).thenReturn(STREAM_ID);
         when(stream.state()).thenReturn(OPEN);
-        when(stream.inboundFlow()).thenReturn(inFlowState);
+        when(stream.garbageCollector()).thenReturn(inFlowState);
         when(pushStream.id()).thenReturn(PUSH_STREAM_ID);
         when(connection.activeStreams()).thenReturn(Collections.singletonList(stream));
         when(connection.stream(STREAM_ID)).thenReturn(stream);

codec-http2/src/test/java/io/netty/handler/codec/http2/DefaultHttp2InboundFlowControllerTest.java

@@ -219,7 +219,7 @@ public class DefaultHttp2InboundFlowControllerTest {
     }
 
     private void returnProcessedBytes(int streamId, int processedBytes) throws Http2Exception {
-        connection.requireStream(streamId).inboundFlow().returnProcessedBytes(ctx, processedBytes);
+        connection.requireStream(streamId).garbageCollector().returnProcessedBytes(ctx, processedBytes);
     }
 
     private void verifyWindowUpdateSent(int streamId, int windowSizeIncrement) throws Http2Exception {