Add basic implementation for the QpackDecoder.

Signed-off-by: Lachlan Roberts <lachlan@webtide.com>

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/QpackContext.java

@@ -38,11 +38,22 @@ public class QpackContext
 
     QpackContext(int maxDynamicTableSize)
     {
-        _dynamicTable = new DynamicTable(maxDynamicTableSize);
+        _dynamicTable = new DynamicTable();
+        _dynamicTable.setCapacity(maxDynamicTableSize);
         if (LOG.isDebugEnabled())
             LOG.debug(String.format("HdrTbl[%x] created max=%d", hashCode(), maxDynamicTableSize));
     }
 
+    public DynamicTable getDynamicTable()
+    {
+        return _dynamicTable;
+    }
+
+    public StaticTable getStaticTable()
+    {
+        return __staticTable;
+    }
+
     public void resize(int newMaxDynamicTableSize)
     {
         _dynamicTable.setCapacity(newMaxDynamicTableSize);

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/QpackDecoder.java

@@ -14,14 +14,24 @@
 package org.eclipse.jetty.http3.qpack;
 
 import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
 
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpHeader;
-import org.eclipse.jetty.http.HttpTokens;
 import org.eclipse.jetty.http.MetaData;
+import org.eclipse.jetty.http3.qpack.generator.DuplicateInstruction;
+import org.eclipse.jetty.http3.qpack.generator.IndexedNameEntryInstruction;
+import org.eclipse.jetty.http3.qpack.generator.InsertCountIncrementInstruction;
 import org.eclipse.jetty.http3.qpack.generator.Instruction;
+import org.eclipse.jetty.http3.qpack.generator.LiteralNameEntryInstruction;
+import org.eclipse.jetty.http3.qpack.generator.SectionAcknowledgmentInstruction;
+import org.eclipse.jetty.http3.qpack.generator.SetCapacityInstruction;
+import org.eclipse.jetty.http3.qpack.parser.EncodedFieldSection;
+import org.eclipse.jetty.http3.qpack.parser.NBitIntegerParser;
+import org.eclipse.jetty.http3.qpack.table.DynamicTable;
 import org.eclipse.jetty.http3.qpack.table.Entry;
-import org.eclipse.jetty.util.BufferUtil;
+import org.eclipse.jetty.http3.qpack.table.StaticTable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -35,19 +45,22 @@ public class QpackDecoder
     public static final HttpField.LongValueHttpField CONTENT_LENGTH_0 =
         new HttpField.LongValueHttpField(HttpHeader.CONTENT_LENGTH, 0L);
 
+    private final Handler _handler;
     private final QpackContext _context;
     private final MetaDataBuilder _builder;
-    private int _localMaxDynamicTableSize;
+
+    private final List<EncodedFieldSection> _encodedFieldSections = new ArrayList<>();
+    private final NBitIntegerParser _integerDecoder = new NBitIntegerParser();
 
     /**
      * @param localMaxDynamicTableSize The maximum allowed size of the local dynamic header field table.
      * @param maxHeaderSize The maximum allowed size of a headers block, expressed as total of all name and value characters, plus 32 per field
      */
-    public QpackDecoder(int localMaxDynamicTableSize, int maxHeaderSize)
+    public QpackDecoder(Handler handler, int localMaxDynamicTableSize, int maxHeaderSize)
     {
         _context = new QpackContext(localMaxDynamicTableSize);
-        _localMaxDynamicTableSize = localMaxDynamicTableSize;
         _builder = new MetaDataBuilder(maxHeaderSize);
+        _handler = handler;
     }
 
     public QpackContext getQpackContext()
@@ -55,11 +68,6 @@ public class QpackDecoder
         return _context;
     }
 
-    public void setLocalMaxDynamicTableSize(int localMaxdynamciTableSize)
-    {
-        _localMaxDynamicTableSize = localMaxdynamciTableSize;
-    }
-
     public interface Handler
     {
         void onMetadata(MetaData metaData);
@@ -67,7 +75,7 @@ public class QpackDecoder
         void onInstruction(Instruction instruction);
     }
 
-    public MetaData decode(ByteBuffer buffer) throws QpackException.SessionException, QpackException.StreamException
+    public void decode(ByteBuffer buffer) throws QpackException
     {
         if (LOG.isDebugEnabled())
             LOG.debug(String.format("CtxTbl[%x] decoding %d octets", _context.hashCode(), buffer.remaining()));
@@ -76,213 +84,117 @@ public class QpackDecoder
         if (buffer.remaining() > _builder.getMaxSize())
             throw new QpackException.SessionException("431 Request Header Fields too large");
 
-        boolean emitted = false;
+        int encodedInsertCount = _integerDecoder.decode(buffer);
+        if (encodedInsertCount < 0)
+            throw new QpackException.CompressionException("Could not parse Required Insert Count");
 
-        while (buffer.hasRemaining())
+        boolean signBit = (buffer.get(buffer.position()) & 0x80) != 0;
+        int deltaBase = _integerDecoder.decode(buffer);
+        if (deltaBase < 0)
+            throw new QpackException.CompressionException("Could not parse Delta Base");
+
+        // Decode the Required Insert Count using the DynamicTable state.
+        DynamicTable dynamicTable = _context.getDynamicTable();
+        int insertCount = dynamicTable.getInsertCount();
+        int maxDynamicTableSize = dynamicTable.getMaxSize();
+        int requiredInsertCount = decodeInsertCount(encodedInsertCount, insertCount, maxDynamicTableSize);
+
+        int base = signBit ? requiredInsertCount - deltaBase - 1 : requiredInsertCount + deltaBase;
+        EncodedFieldSection encodedFieldSection = new EncodedFieldSection(requiredInsertCount, base);
+        encodedFieldSection.parse(buffer);
+
+        int streamId = -1;
+
+        if (encodedFieldSection.getRequiredInsertCount() >= insertCount)
         {
-            if (LOG.isDebugEnabled())
+            MetaData metadata = encodedFieldSection.decode(_context, _builder);
-                LOG.debug("decode {}", BufferUtil.toHexString(buffer));
+            _handler.onMetadata(metadata);
-
+            _handler.onInstruction(new SectionAcknowledgmentInstruction(streamId));
-            byte b = buffer.get();
-            if (b < 0)
-            {
-                // 7.1 indexed if the high bit is set
-                int index = NBitInteger.decode(buffer, 7);
-                Entry entry = _context.get(index);
-                if (entry == null)
-                    throw new QpackException.SessionException("Unknown index %d", index);
-
-                if (entry.isStatic())
-                {
-                    if (LOG.isDebugEnabled())
-                        LOG.debug("decode IdxStatic {}", entry);
-                    // emit field
-                    emitted = true;
-                    _builder.emit(entry.getHttpField());
-
-                    // TODO copy and add to reference set if there is room
-                    // _context.add(entry.getHttpField());
         }
         else
         {
-                    if (LOG.isDebugEnabled())
+            _encodedFieldSections.add(encodedFieldSection);
-                        LOG.debug("decode Idx {}", entry);
-                    // emit
-                    emitted = true;
-                    _builder.emit(entry.getHttpField());
         }
     }
+
+    public void onInstruction(Instruction instruction) throws QpackException
+    {
+        StaticTable staticTable = _context.getStaticTable();
+        DynamicTable dynamicTable = _context.getDynamicTable();
+        if (instruction instanceof SetCapacityInstruction)
+        {
+            int capacity = ((SetCapacityInstruction)instruction).getCapacity();
+            dynamicTable.setCapacity(capacity);
+        }
+        else if (instruction instanceof DuplicateInstruction)
+        {
+            DuplicateInstruction duplicate = (DuplicateInstruction)instruction;
+            Entry entry = dynamicTable.get(duplicate.getIndex());
+
+            // Add the new Entry to the DynamicTable.
+            if (dynamicTable.add(entry) == null)
+                throw new QpackException.StreamException("No space in DynamicTable");
+            _handler.onInstruction(new InsertCountIncrementInstruction(1));
+        }
+        else if (instruction instanceof IndexedNameEntryInstruction)
+        {
+            IndexedNameEntryInstruction nameEntryInstruction = (IndexedNameEntryInstruction)instruction;
+            int index = nameEntryInstruction.getIndex();
+            String value = nameEntryInstruction.getValue();
+            Entry referencedEntry = nameEntryInstruction.isDynamic() ? dynamicTable.get(index) : staticTable.get(index);
+
+            // Add the new Entry to the DynamicTable.
+            Entry entry = new Entry(new HttpField(referencedEntry.getHttpField().getHeader(), referencedEntry.getHttpField().getName(), value));
+            if (dynamicTable.add(entry) == null)
+                throw new QpackException.StreamException("No space in DynamicTable");
+            _handler.onInstruction(new InsertCountIncrementInstruction(1));
+        }
+        else if (instruction instanceof LiteralNameEntryInstruction)
+        {
+            LiteralNameEntryInstruction literalEntryInstruction = (LiteralNameEntryInstruction)instruction;
+            String name = literalEntryInstruction.getName();
+            String value = literalEntryInstruction.getValue();
+            Entry entry = new Entry(new HttpField(name, value));
+
+            // Add the new Entry to the DynamicTable.
+            if (dynamicTable.add(entry) == null)
+                throw new QpackException.StreamException("No space in DynamicTable");
+            _handler.onInstruction(new InsertCountIncrementInstruction(1));
+        }
         else
         {
-                // look at the first nibble in detail
+            throw new IllegalStateException("Invalid Encoder Instruction");
-                byte f = (byte)((b & 0xF0) >> 4);
+        }
-                String name;
+    }
-                HttpHeader header;
-                String value;
 
-                boolean indexed;
+    private static int decodeInsertCount(int encInsertCount, int totalNumInserts, int maxTableCapacity) throws QpackException
-                int nameIndex;
-
-                switch (f)
     {
-                    case 2: // 7.3
+        if (encInsertCount == 0)
-                    case 3: // 7.3
+            return 0;
-                        // change table size
-                        int size = NBitInteger.decode(buffer, 5);
-                        if (LOG.isDebugEnabled())
-                            LOG.debug("decode resize={}", size);
-                        if (size > _localMaxDynamicTableSize)
-                            throw new IllegalArgumentException();
-                        if (emitted)
-                            throw new QpackException.CompressionException("Dynamic table resize after fields");
-                        _context.resize(size);
-                        continue;
 
-                    case 0: // 7.2.2
+        int maxEntries = maxTableCapacity / 32;
-                    case 1: // 7.2.3
+        int fullRange = 2 * maxEntries;
-                        indexed = false;
+        if (encInsertCount > fullRange)
-                        nameIndex = NBitInteger.decode(buffer, 4);
+            throw new QpackException.CompressionException("encInsertCount > fullRange");
-                        break;
 
-                    case 4: // 7.2.1
+        // MaxWrapped is the largest possible value of ReqInsertCount that is 0 mod 2 * MaxEntries.
-                    case 5: // 7.2.1
+        int maxValue = totalNumInserts + maxEntries;
-                    case 6: // 7.2.1
+        int maxWrapped = (maxValue / fullRange) * fullRange;
-                    case 7: // 7.2.1
+        int reqInsertCount = maxWrapped + encInsertCount - 1;
-                        indexed = true;
-                        nameIndex = NBitInteger.decode(buffer, 6);
-                        break;
 
-                    default:
+        // If reqInsertCount exceeds maxValue, the Encoder's value must have wrapped one fewer time.
-                        throw new IllegalStateException();
+        if (reqInsertCount > maxValue)
-                }
-
-                boolean huffmanName = false;
-
-                // decode the name
-                if (nameIndex > 0)
         {
-                    Entry nameEntry = _context.get(nameIndex);
+            if (reqInsertCount <= fullRange)
-                    name = nameEntry.getHttpField().getName();
+                throw new QpackException.CompressionException("reqInsertCount <= fullRange");
-                    header = nameEntry.getHttpField().getHeader();
+            reqInsertCount -= fullRange;
-                }
-                else
-                {
-                    huffmanName = (buffer.get() & 0x80) == 0x80;
-                    int length = NBitInteger.decode(buffer, 7);
-                    _builder.checkSize(length, huffmanName);
-                    if (huffmanName)
-                        name = Huffman.decode(buffer, length);
-                    else
-                        name = toASCIIString(buffer, length);
-                    check:
-                    for (int i = name.length(); i-- > 0; )
-                    {
-                        char c = name.charAt(i);
-                        if (c > 0xff)
-                        {
-                            _builder.streamException("Illegal header name %s", name);
-                            break;
-                        }
-                        HttpTokens.Token token = HttpTokens.TOKENS[0xFF & c];
-                        switch (token.getType())
-                        {
-                            case ALPHA:
-                                if (c >= 'A' && c <= 'Z')
-                                {
-                                    _builder.streamException("Uppercase header name %s", name);
-                                    break check;
-                                }
-                                break;
-
-                            case COLON:
-                            case TCHAR:
-                            case DIGIT:
-                                break;
-
-                            default:
-                                _builder.streamException("Illegal header name %s", name);
-                                break check;
-                        }
-                    }
-                    header = HttpHeader.CACHE.get(name);
         }
 
-                // decode the value
+        // Value of 0 must be encoded as 0.
-                boolean huffmanValue = (buffer.get() & 0x80) == 0x80;
+        if (reqInsertCount == 0)
-                int length = NBitInteger.decode(buffer, 7);
+            throw new QpackException.CompressionException("reqInsertCount == 0");
-                _builder.checkSize(length, huffmanValue);
-                if (huffmanValue)
-                    value = Huffman.decode(buffer, length);
-                else
-                    value = toASCIIString(buffer, length);
 
-                // Make the new field
+        return reqInsertCount;
-                HttpField field;
-                if (header == null)
-                {
-                    // just make a normal field and bypass header name lookup
-                    field = new HttpField(null, name, value);
-                }
-                else
-                {
-                    // might be worthwhile to create a value HttpField if it is indexed
-                    // and/or of a type that may be looked up multiple times.
-                    switch (header)
-                    {
-                        case C_STATUS:
-                            if (indexed)
-                                field = new HttpField.IntValueHttpField(header, name, value);
-                            else
-                                field = new HttpField(header, name, value);
-                            break;
-
-                        case C_AUTHORITY:
-                            field = new AuthorityHttpField(value);
-                            break;
-
-                        case CONTENT_LENGTH:
-                            if ("0".equals(value))
-                                field = CONTENT_LENGTH_0;
-                            else
-                                field = new HttpField.LongValueHttpField(header, name, value);
-                            break;
-
-                        default:
-                            field = new HttpField(header, name, value);
-                            break;
-                    }
-                }
-
-                if (LOG.isDebugEnabled())
-                {
-                    LOG.debug("decoded '{}' by {}/{}/{}",
-                        field,
-                        nameIndex > 0 ? "IdxName" : (huffmanName ? "HuffName" : "LitName"),
-                        huffmanValue ? "HuffVal" : "LitVal",
-                        indexed ? "Idx" : "");
-                }
-
-                // emit the field
-                emitted = true;
-                _builder.emit(field);
-
-                // if indexed add to dynamic table
-                if (indexed)
-                    _context.add(field);
-            }
-        }
-
-        return _builder.build();
-    }
-
-    public static String toASCIIString(ByteBuffer buffer, int length)
-    {
-        StringBuilder builder = new StringBuilder(length);
-        for (int i = 0; i < length; ++i)
-        {
-            builder.append((char)(0x7F & buffer.get()));
-        }
-        return builder.toString();
     }
 
     @Override

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/QpackException.java

@@ -30,7 +30,7 @@ public abstract class QpackException extends Exception
      */
     public static class StreamException extends QpackException
     {
-        StreamException(String messageFormat, Object... args)
+        public StreamException(String messageFormat, Object... args)
         {
             super(messageFormat, args);
         }
@@ -43,7 +43,7 @@ public abstract class QpackException extends Exception
      */
     public static class SessionException extends QpackException
     {
-        SessionException(String messageFormat, Object... args)
+        public SessionException(String messageFormat, Object... args)
         {
             super(messageFormat, args);
         }

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/DuplicateInstruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import java.nio.ByteBuffer;
@@ -15,6 +28,11 @@ public class DuplicateInstruction implements Instruction
         _index = index;
     }
 
+    public int getIndex()
+    {
+        return _index;
+    }
+
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/IndexedNameEntryInstruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import java.nio.ByteBuffer;
@@ -22,6 +35,21 @@ public class IndexedNameEntryInstruction implements Instruction
         _value = value;
     }
 
+    public boolean isDynamic()
+    {
+        return _dynamic;
+    }
+
+    public int getIndex()
+    {
+        return _index;
+    }
+
+    public String getValue()
+    {
+        return _value;
+    }
+
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/InsertCountIncrementInstruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import java.nio.ByteBuffer;

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/Instruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import org.eclipse.jetty.io.ByteBufferPool;

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/LiteralNameEntryInstruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import java.nio.ByteBuffer;
@@ -22,6 +35,16 @@ public class LiteralNameEntryInstruction implements Instruction
         _value = value;
     }
 
+    public String getName()
+    {
+        return _name;
+    }
+
+    public String getValue()
+    {
+        return _value;
+    }
+
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/SectionAcknowledgmentInstruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import java.nio.ByteBuffer;

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/SetCapacityInstruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import java.nio.ByteBuffer;
@@ -15,6 +28,11 @@ public class SetCapacityInstruction implements Instruction
         _capacity = capacity;
     }
 
+    public int getCapacity()
+    {
+        return _capacity;
+    }
+
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/generator/StreamCancellationInstruction.java

@@ -1,3 +1,16 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
 package org.eclipse.jetty.http3.qpack.generator;
 
 import java.nio.ByteBuffer;

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/parser/EncodedFieldSection.java

@@ -0,0 +1,277 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
+package org.eclipse.jetty.http3.qpack.parser;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.jetty.http.HttpField;
+import org.eclipse.jetty.http.MetaData;
+import org.eclipse.jetty.http3.qpack.MetaDataBuilder;
+import org.eclipse.jetty.http3.qpack.QpackContext;
+import org.eclipse.jetty.http3.qpack.QpackException;
+
+public class EncodedFieldSection
+{
+    private final NBitIntegerParser _integerParser = new NBitIntegerParser();
+    private final NBitStringParser _stringParser = new NBitStringParser();
+    private final List<EncodedField> _encodedFields = new ArrayList<>();
+
+    private final int _requiredInsertCount;
+    private final int _base;
+
+    public EncodedFieldSection(int requiredInsertCount, int base)
+    {
+        _requiredInsertCount = requiredInsertCount;
+        _base = base;
+    }
+
+    public int getRequiredInsertCount()
+    {
+        return _requiredInsertCount;
+    }
+
+    public void parse(ByteBuffer buffer) throws QpackException
+    {
+        while (buffer.hasRemaining())
+        {
+            EncodedField encodedField;
+            byte firstByte = buffer.get(buffer.position());
+            if ((firstByte & 0x80) != 0)
+                encodedField = parseIndexedFieldLine(buffer);
+            else if ((firstByte & 0x40) != 0)
+                encodedField = parseLiteralFieldLineWithNameReference(buffer);
+            else if ((firstByte & 0x20) != 0)
+                encodedField = parseLiteralFieldLineWithLiteralName(buffer);
+            else if ((firstByte & 0x10) != 0)
+                encodedField = parseIndexFieldLineWithPostBaseIndex(buffer);
+            else
+                encodedField = parseLiteralFieldLineWithPostBaseNameReference(buffer);
+
+            _encodedFields.add(encodedField);
+        }
+    }
+
+    public MetaData decode(QpackContext context, MetaDataBuilder builder) throws QpackException
+    {
+        if (context.getDynamicTable().getInsertCount() < _requiredInsertCount)
+            throw new IllegalStateException("Required Insert Count Not Reached");
+
+        for (EncodedField encodedField : _encodedFields)
+        {
+            builder.emit(encodedField.decode(context));
+        }
+
+        return builder.build();
+    }
+
+    private EncodedField parseIndexedFieldLine(ByteBuffer buffer) throws QpackException
+    {
+        byte firstByte = buffer.get(buffer.position());
+        boolean dynamicTable = (firstByte & 0x40) == 0;
+        _integerParser.setPrefix(6);
+        int index = _integerParser.decode(buffer);
+        if (index < 0)
+            throw new QpackException.CompressionException("Invalid Index");
+        return new IndexedField(dynamicTable, index);
+    }
+
+    private EncodedField parseLiteralFieldLineWithNameReference(ByteBuffer buffer) throws QpackException
+    {
+        byte firstByte = buffer.get(buffer.position());
+        boolean allowEncoding = (firstByte & 0x20) != 0;
+        boolean dynamicTable = (firstByte & 0x10) == 0;
+
+        _integerParser.setPrefix(4);
+        int nameIndex = _integerParser.decode(buffer);
+        if (nameIndex < 0)
+            throw new QpackException.CompressionException("Invalid Name Index");
+
+        _stringParser.setPrefix(8);
+        String value = _stringParser.decode(buffer);
+        if (value == null)
+            throw new QpackException.CompressionException("Value");
+
+        return new IndexedNameField(allowEncoding, dynamicTable, nameIndex, value);
+    }
+
+    private EncodedField parseLiteralFieldLineWithLiteralName(ByteBuffer buffer) throws QpackException
+    {
+        byte firstByte = buffer.get(buffer.position());
+        boolean allowEncoding = (firstByte & 0x10) != 0;
+
+        _stringParser.setPrefix(3);
+        String name = _stringParser.decode(buffer);
+        if (name == null)
+            throw new QpackException.CompressionException("Invalid Name");
+
+        _stringParser.setPrefix(8);
+        String value = _stringParser.decode(buffer);
+        if (value == null)
+            throw new QpackException.CompressionException("Invalid Value");
+
+        return new LiteralField(allowEncoding, name, value);
+    }
+
+    private EncodedField parseLiteralFieldLineWithPostBaseNameReference(ByteBuffer buffer) throws QpackException
+    {
+        byte firstByte = buffer.get(buffer.position());
+        boolean allowEncoding = (firstByte & 0x08) != 0;
+
+        _integerParser.setPrefix(3);
+        int nameIndex = _integerParser.decode(buffer);
+        if (nameIndex < 0)
+            throw new QpackException.CompressionException("Invalid Index");
+
+        _stringParser.setPrefix(8);
+        String value = _stringParser.decode(buffer);
+        if (value == null)
+            throw new QpackException.CompressionException("Invalid Value");
+
+        return new PostBaseIndexedNameField(allowEncoding, nameIndex, value);
+    }
+
+    private EncodedField parseIndexFieldLineWithPostBaseIndex(ByteBuffer buffer) throws QpackException
+    {
+        _integerParser.setPrefix(4);
+        int index = _integerParser.decode(buffer);
+        if (index < 0)
+            throw new QpackException.CompressionException("Invalid Index");
+
+        return new PostBaseIndexedField(index);
+    }
+
+    public interface EncodedField
+    {
+        HttpField decode(QpackContext context) throws QpackException;
+    }
+
+    private class LiteralField implements EncodedField
+    {
+        private final boolean _allowEncoding;
+        private final String _name;
+        private final String _value;
+
+        public LiteralField(boolean allowEncoding, String name, String value)
+        {
+            _allowEncoding = allowEncoding;
+            _name = name;
+            _value = value;
+        }
+
+        @Override
+        public HttpField decode(QpackContext context)
+        {
+            return new HttpField(_name, _value);
+        }
+    }
+
+    private class IndexedField implements EncodedField
+    {
+        private final boolean _dynamicTable;
+        private final int _index;
+
+        public IndexedField(boolean dynamicTable, int index)
+        {
+            _dynamicTable = dynamicTable;
+            _index = index;
+        }
+
+        @Override
+        public HttpField decode(QpackContext context) throws QpackException
+        {
+            if (_dynamicTable)
+                return context.getDynamicTable().getAbsolute(_base + _index + 1).getHttpField();
+            else
+                return context.getStaticTable().get(_index).getHttpField();
+        }
+    }
+
+    private class PostBaseIndexedField implements EncodedField
+    {
+        private final int _index;
+
+        public PostBaseIndexedField(int index)
+        {
+            _index = index;
+        }
+
+        @Override
+        public HttpField decode(QpackContext context) throws QpackException
+        {
+            return context.getDynamicTable().getAbsolute(_base - _index).getHttpField();
+        }
+    }
+
+    private class IndexedNameField implements EncodedField
+    {
+        private final boolean _allowEncoding;
+        private final boolean _dynamicTable;
+        private final int _nameIndex;
+        private final String _value;
+
+        public IndexedNameField(boolean allowEncoding, boolean dynamicTable, int nameIndex, String value)
+        {
+            _allowEncoding = allowEncoding;
+            _dynamicTable = dynamicTable;
+            _nameIndex = nameIndex;
+            _value = value;
+        }
+
+        @Override
+        public HttpField decode(QpackContext context) throws QpackException
+        {
+            HttpField field;
+            if (_dynamicTable)
+                field = context.getDynamicTable().getAbsolute(_base + _nameIndex + 1).getHttpField();
+            else
+                field = context.getStaticTable().get(_nameIndex).getHttpField();
+
+            return new HttpField(field.getHeader(), field.getName(), _value);
+        }
+    }
+
+    private class PostBaseIndexedNameField implements EncodedField
+    {
+        private final boolean _allowEncoding;
+        private final int _nameIndex;
+        private final String _value;
+
+        public PostBaseIndexedNameField(boolean allowEncoding, int nameIndex, String value)
+        {
+            _allowEncoding = allowEncoding;
+            _nameIndex = nameIndex;
+            _value = value;
+        }
+
+        @Override
+        public HttpField decode(QpackContext context) throws QpackException
+        {
+            HttpField field = context.getDynamicTable().getAbsolute(_base - _nameIndex).getHttpField();
+            return new HttpField(field.getHeader(), field.getName(), _value);
+        }
+    }
+
+    // TODO: move to QpackEncoder.
+    @SuppressWarnings("unused")
+    public static int encodeInsertCount(int reqInsertCount, int maxTableCapacity)
+    {
+        if (reqInsertCount == 0)
+            return 0;
+
+        int maxEntries = maxTableCapacity / 32;
+        return (reqInsertCount % (2 * maxEntries)) + 1;
+    }
+}

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/table/DynamicTable.java

@@ -13,84 +13,79 @@
 
 package org.eclipse.jetty.http3.qpack.table;
 
-import java.util.Arrays;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http3.qpack.QpackContext;
+import org.eclipse.jetty.http3.qpack.QpackException;
 
 public class DynamicTable
 {
     public static final int FIRST_INDEX = StaticTable.STATIC_SIZE + 1;
-    private int _maxDynamicTableSizeInBytes;
+    private int _maxCapacity;
-    private int _dynamicTableSizeInBytes;
+    private int _capacity;
+    private int _absoluteIndex;
 
     private final Map<HttpField, Entry> _fieldMap = new HashMap<>();
     private final Map<String, Entry> _nameMap = new HashMap<>();
-    private final int _growby;
+    private final List<Entry> _entries = new ArrayList<>();
 
-    private Entry[] _entries;
+    private final Map<Integer, StreamInfo> streamInfoMap = new HashMap<>();
-    private int _numEntries;
-    private int _offset;
 
-    public DynamicTable(int maxSize)
+    public static class StreamInfo
+    {
+        private int streamId;
+        private final List<Integer> referencedEntries = new ArrayList<>();
+        private int potentiallyBlockedStreams = 0;
+    }
+
+    public DynamicTable()
     {
-        _maxDynamicTableSizeInBytes = maxSize;
-        int initCapacity = 10 + maxSize / (32 + 10 + 10);
-        _entries = new Entry[initCapacity];
-        _growby = initCapacity;
     }
 
     public Entry add(Entry entry)
     {
+        evict();
+
         int size = entry.getSize();
-        if (size > _maxDynamicTableSizeInBytes)
+        if (size + _capacity > _maxCapacity)
         {
             if (QpackContext.LOG.isDebugEnabled())
-                QpackContext.LOG.debug(String.format("HdrTbl[%x] !added size %d>%d", hashCode(), size, _maxDynamicTableSizeInBytes));
+                QpackContext.LOG.debug(String.format("HdrTbl[%x] !added size %d>%d", hashCode(), size, _maxCapacity));
-            evictAll();
             return null;
         }
-        _dynamicTableSizeInBytes += size;
+        _capacity += size;
-
-        if (_numEntries == _entries.length)
-        {
-            Entry[] entries = new Entry[_entries.length + _growby];
-            for (int i = 0; i < _numEntries; i++)
-            {
-                int slot = (_offset + i) % _entries.length;
-                entries[i] = _entries[slot];
-                entries[i].setIndex(i);
-            }
-            _entries = entries;
-            _offset = 0;
-        }
-        int slot = (_numEntries++ + _offset) % _entries.length;
-        _entries[slot] = entry;
-        entry.setIndex(slot);
 
+        // Set the Entries absolute index which will never change.
+        entry.setIndex(_absoluteIndex++);
+        _entries.add(0, entry);
         _fieldMap.put(entry.getHttpField(), entry);
         _nameMap.put(entry.getHttpField().getLowerCaseName(), entry);
 
         if (QpackContext.LOG.isDebugEnabled())
             QpackContext.LOG.debug(String.format("HdrTbl[%x] added %s", hashCode(), entry));
-        evict();
         return entry;
     }
 
     public int index(Entry entry)
     {
-        return StaticTable.STATIC_SIZE + _numEntries - (entry.getIndex() - _offset + _entries.length) % _entries.length;
+        // TODO: should we improve efficiency of this by storing in the entry itself.
+        return _entries.indexOf(entry);
+    }
+
+    public Entry getAbsolute(int absoluteIndex) throws QpackException
+    {
+        if (absoluteIndex < 0)
+            throw new QpackException.CompressionException("Invalid Index");
+        return _entries.stream().filter(e -> e.getIndex() == absoluteIndex).findFirst().orElse(null);
     }
 
     public Entry get(int index)
     {
-        int d = index - StaticTable.STATIC_SIZE - 1;
+        return _entries.get(index);
-        if (d < 0 || d >= _numEntries)
-            return null;
-        int slot = (_offset + _numEntries - d - 1) % _entries.length;
-        return _entries[slot];
     }
 
     public Entry get(String name)
@@ -105,66 +100,91 @@ public class DynamicTable
 
     public int getSize()
     {
-        return _dynamicTableSizeInBytes;
+        return _capacity;
     }
 
     public int getMaxSize()
     {
-        return _maxDynamicTableSizeInBytes;
+        return _maxCapacity;
     }
 
     public int getNumEntries()
     {
-        return _numEntries;
+        return _entries.size();
+    }
+
+    public int getInsertCount()
+    {
+        return _absoluteIndex;
     }
 
     public void setCapacity(int capacity)
     {
         if (QpackContext.LOG.isDebugEnabled())
-            QpackContext.LOG.debug(String.format("HdrTbl[%x] resized max=%d->%d", hashCode(), _maxDynamicTableSizeInBytes, capacity));
+            QpackContext.LOG.debug(String.format("HdrTbl[%x] resized max=%d->%d", hashCode(), _maxCapacity, capacity));
-        _maxDynamicTableSizeInBytes = capacity;
+        _maxCapacity = capacity;
         evict();
     }
 
+    private boolean canReference(Entry entry)
+    {
+        int evictionThreshold = getEvictionThreshold();
+        int lowestReferencableIndex = -1;
+        int remainingCapacity = _capacity;
+        for (int i = 0; i < _entries.size(); i++)
+        {
+            if (remainingCapacity <= evictionThreshold)
+            {
+                lowestReferencableIndex = i;
+                break;
+            }
+
+            remainingCapacity -= _entries.get(i).getSize();
+        }
+
+        return index(entry) >= lowestReferencableIndex;
+    }
+
     private void evict()
     {
-        while (_dynamicTableSizeInBytes > _maxDynamicTableSizeInBytes)
+        int evictionThreshold = getEvictionThreshold();
+        for (Entry e : _entries)
         {
-            Entry entry = _entries[_offset];
+            // We only evict when the table is getting full.
-            _entries[_offset] = null;
+            if (_capacity < evictionThreshold)
-            _offset = (_offset + 1) % _entries.length;
+                return;
-            _numEntries--;
+
+            // We can only evict if there are no references outstanding to this entry.
+            if (e.getReferenceCount() != 0)
+                return;
+
+            // Remove this entry.
             if (QpackContext.LOG.isDebugEnabled())
-                QpackContext.LOG.debug(String.format("HdrTbl[%x] evict %s", hashCode(), entry));
+                QpackContext.LOG.debug(String.format("HdrTbl[%x] evict %s", hashCode(), e));
-            _dynamicTableSizeInBytes -= entry.getSize();
+
-            entry.setIndex(-1);
+            Entry removedEntry = _entries.remove(0);
-            _fieldMap.remove(entry.getHttpField());
+            if (removedEntry != e)
-            String lc = entry.getHttpField().getLowerCaseName();
+                throw new IllegalStateException("Corruption in DynamicTable");
-            if (entry == _nameMap.get(lc))
+            _fieldMap.remove(e.getHttpField());
-                _nameMap.remove(lc);
+            String name = e.getHttpField().getLowerCaseName();
-        }
+            if (e == _nameMap.get(name))
-        if (QpackContext.LOG.isDebugEnabled())
+                _nameMap.remove(name);
-            QpackContext.LOG.debug(String.format("HdrTbl[%x] entries=%d, size=%d, max=%d", hashCode(), getNumEntries(), _dynamicTableSizeInBytes, _maxDynamicTableSizeInBytes));
+
+            _capacity -= e.getSize();
         }
 
-    private void evictAll()
-    {
         if (QpackContext.LOG.isDebugEnabled())
-            QpackContext.LOG.debug(String.format("HdrTbl[%x] evictAll", hashCode()));
+            QpackContext.LOG.debug(String.format("HdrTbl[%x] entries=%d, size=%d, max=%d", hashCode(), getNumEntries(), _capacity, _maxCapacity));
-        if (getNumEntries() > 0)
-        {
-            _fieldMap.clear();
-            _nameMap.clear();
-            _offset = 0;
-            _numEntries = 0;
-            _dynamicTableSizeInBytes = 0;
-            Arrays.fill(_entries, null);
     }
+
+    private int getEvictionThreshold()
+    {
+        return _maxCapacity * 3 / 4;
     }
 
     @Override
     public String toString()
     {
-        return String.format("%s@%x{entries=%d,size=%d,max=%d}", getClass().getSimpleName(), hashCode(), getNumEntries(), _dynamicTableSizeInBytes, _maxDynamicTableSizeInBytes);
+        return String.format("%s@%x{entries=%d,size=%d,max=%d}", getClass().getSimpleName(), hashCode(), getNumEntries(), _capacity, _maxCapacity);
     }
 }

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/table/Entry.java

@@ -13,12 +13,15 @@
 
 package org.eclipse.jetty.http3.qpack.table;
 
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.eclipse.jetty.http.HttpField;
 
 public class Entry
 {
-    final HttpField _field;
+    private final HttpField _field;
-    private int _slot; // The index within it's array
+    private int _absoluteIndex;
+    private AtomicInteger _referenceCount = new AtomicInteger(0);
 
     public Entry()
     {
@@ -33,7 +36,7 @@ public class Entry
     public Entry(int index, HttpField field)
     {
         _field = field;
-        _slot = index;
+        _absoluteIndex = index;
     }
 
     public int getSize()
@@ -44,12 +47,12 @@ public class Entry
 
     public void setIndex(int index)
     {
-        _slot = index;
+        _absoluteIndex = index;
     }
 
     public int getIndex()
     {
-        return _slot;
+        return _absoluteIndex;
     }
 
     public HttpField getHttpField()
@@ -57,6 +60,11 @@ public class Entry
         return _field;
     }
 
+    public int getReferenceCount()
+    {
+        return _referenceCount.get();
+    }
+
     public boolean isStatic()
     {
         return false;
@@ -70,6 +78,6 @@ public class Entry
     @Override
     public String toString()
     {
-        return String.format("{%s,%d,%s,%x}", isStatic() ? "S" : "D", _slot, _field, hashCode());
+        return String.format("{%s,%d,%s,%x}", isStatic() ? "S" : "D", _absoluteIndex, _field, hashCode());
     }
 }

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/table/StaticTable.java

@@ -150,13 +150,13 @@ public class StaticTable
 
             _staticTable[i] = entry;
 
-            if (entry._field.getValue() != null)
+            if (entry.getHttpField().getValue() != null)
-                _staticFieldMap.put(entry._field, entry);
+                _staticFieldMap.put(entry.getHttpField(), entry);
 
-            if (!added.contains(entry._field.getName()))
+            if (!added.contains(entry.getHttpField().getName()))
             {
-                added.add(entry._field.getName());
+                added.add(entry.getHttpField().getName());
-                staticNameMapBuilder.with(entry._field.getName(), entry);
+                staticNameMapBuilder.with(entry.getHttpField().getName(), entry);
             }
         }
         _staticNameMap = staticNameMapBuilder.build();

jetty-http3/http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/DecoderTestHandler.java

@@ -0,0 +1,53 @@
+//
+// ========================================================================
+// Copyright (c) 1995-2021 Mort Bay Consulting Pty Ltd and others.
+//
+// This program and the accompanying materials are made available under the
+// terms of the Eclipse Public License v. 2.0 which is available at
+// https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
+// which is available at https://www.apache.org/licenses/LICENSE-2.0.
+//
+// SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
+// ========================================================================
+//
+
+package org.eclipse.jetty.http3.qpack;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+import org.eclipse.jetty.http.MetaData;
+import org.eclipse.jetty.http3.qpack.generator.Instruction;
+
+public class DecoderTestHandler implements QpackDecoder.Handler
+{
+    private final Queue<MetaData> _metadataList = new LinkedList<>();
+    private final Queue<Instruction> _instructionList = new LinkedList<>();
+
+    @Override
+    public void onMetadata(MetaData metaData)
+    {
+        _metadataList.add(metaData);
+    }
+
+    @Override
+    public void onInstruction(Instruction instruction)
+    {
+        _instructionList.add(instruction);
+    }
+
+    public MetaData getMetaData()
+    {
+        return _metadataList.poll();
+    }
+
+    public Instruction getInstruction()
+    {
+        return _instructionList.poll();
+    }
+
+    public boolean isEmpty()
+    {
+        return _metadataList.isEmpty() && _instructionList.isEmpty();
+    }
+}

jetty-http3/http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackDecoderTest.java

@@ -54,16 +54,19 @@ public class QpackDecoderTest
      +-------------------------------+
      */
 
+    private final DecoderTestHandler handler = new DecoderTestHandler();
+
     @Test
     public void testDecodeD3() throws Exception
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         // First request
         String encoded = "828684410f7777772e6578616d706c652e636f6d";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        MetaData.Request request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData.Request request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTP.asString(), request.getURI().getScheme());
@@ -75,7 +78,8 @@ public class QpackDecoderTest
         encoded = "828684be58086e6f2d6361636865";
         buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTP.asString(), request.getURI().getScheme());
@@ -90,7 +94,8 @@ public class QpackDecoderTest
         encoded = "828785bf400a637573746f6d2d6b65790c637573746f6d2d76616c7565";
         buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTPS.asString(), request.getURI().getScheme());
@@ -105,13 +110,14 @@ public class QpackDecoderTest
     @Test
     public void testDecodeD4() throws Exception
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         // First request
         String encoded = "828684418cf1e3c2e5f23a6ba0ab90f4ff";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        MetaData.Request request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData.Request request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTP.asString(), request.getURI().getScheme());
@@ -123,7 +129,8 @@ public class QpackDecoderTest
         encoded = "828684be5886a8eb10649cbf";
         buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTP.asString(), request.getURI().getScheme());
@@ -140,14 +147,15 @@ public class QpackDecoderTest
     {
         String value = "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==";
 
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
         String encoded = "8682418cF1E3C2E5F23a6bA0Ab90F4Ff841f0822426173696320515778685a475270626a70766347567549484e6c633246745a513d3d";
         byte[] bytes = TypeUtil.fromHexString(encoded);
         byte[] array = new byte[bytes.length + 1];
         System.arraycopy(bytes, 0, array, 1, bytes.length);
         ByteBuffer buffer = ByteBuffer.wrap(array, 1, bytes.length).slice();
 
-        MetaData.Request request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData.Request request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTP.asString(), request.getURI().getScheme());
@@ -162,7 +170,7 @@ public class QpackDecoderTest
     @Test
     public void testDecodeHuffmanWithArrayOffset() throws Exception
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "8286418cf1e3c2e5f23a6ba0ab90f4ff84";
         byte[] bytes = TypeUtil.fromHexString(encoded);
@@ -170,7 +178,8 @@ public class QpackDecoderTest
         System.arraycopy(bytes, 0, array, 1, bytes.length);
         ByteBuffer buffer = ByteBuffer.wrap(array, 1, bytes.length).slice();
 
-        MetaData.Request request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData.Request request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTP.asString(), request.getURI().getScheme());
@@ -186,8 +195,9 @@ public class QpackDecoderTest
         String encoded = "886196C361Be940b6a65B6850400B8A00571972e080a62D1Bf5f87497cA589D34d1f9a0f0d0234327690Aa69D29aFcA954D3A5358980Ae112e0f7c880aE152A9A74a6bF3";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
-        MetaData.Response response = (MetaData.Response)decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData.Response response = (MetaData.Response)handler.getMetaData();
 
         assertThat(response.getStatus(), is(200));
         assertThat(response.getFields().size(), is(6));
@@ -204,8 +214,9 @@ public class QpackDecoderTest
     {
         String encoded = "203f136687A0E41d139d090760881c6490B2Cd39Ba7f";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
-        MetaData metaData = decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData metaData = handler.getMetaData();
         assertThat(metaData.getFields().get(HttpHeader.HOST), is("localhost0"));
         assertThat(metaData.getFields().get(HttpHeader.COOKIE), is("abcdefghij"));
         assertThat(decoder.getQpackContext().getMaxDynamicTableSize(), is(50));
@@ -226,7 +237,7 @@ public class QpackDecoderTest
 
         String encoded = "203f136687A0E41d139d090760881c6490B2Cd39Ba7f20";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
         try
         {
             decoder.decode(buffer);
@@ -244,8 +255,9 @@ public class QpackDecoderTest
         String encoded = "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";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        QpackDecoder decoder = new QpackDecoder(128, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 128, 8192);
-        MetaData metaData = decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData metaData = handler.getMetaData();
 
         assertThat(decoder.getQpackContext().getDynamicTableSize(), is(0));
         assertThat(metaData.getFields().get("host"), Matchers.startsWith("This is a very large field"));
@@ -257,7 +269,7 @@ public class QpackDecoderTest
         String encoded = "BE";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        QpackDecoder decoder = new QpackDecoder(128, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 128, 8192);
 
         try
         {
@@ -442,12 +454,13 @@ public class QpackDecoderTest
     @Test
     public void testHuffmanEncodedStandard() throws Exception
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "82868441" + "83" + "49509F";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
 
-        MetaData.Request request = (MetaData.Request)decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData.Request request = (MetaData.Request)handler.getMetaData();
 
         assertEquals("GET", request.getMethod());
         assertEquals(HttpScheme.HTTP.asString(), request.getURI().getScheme());
@@ -460,7 +473,7 @@ public class QpackDecoderTest
     @Test
     public void testHuffmanEncodedExtraPadding()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "82868441" + "84" + "49509FFF";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
@@ -472,7 +485,7 @@ public class QpackDecoderTest
     @Test
     public void testHuffmanEncodedZeroPadding()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "82868441" + "83" + "495090";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
@@ -485,7 +498,7 @@ public class QpackDecoderTest
     @Test
     public void testHuffmanEncodedWithEOS()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "82868441" + "87" + "497FFFFFFF427F";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
@@ -497,7 +510,7 @@ public class QpackDecoderTest
     @Test
     public void testHuffmanEncodedOneIncompleteOctet()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "82868441" + "81" + "FE";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
@@ -509,7 +522,7 @@ public class QpackDecoderTest
     @Test
     public void testHuffmanEncodedTwoIncompleteOctet()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "82868441" + "82" + "FFFE";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
@@ -521,7 +534,7 @@ public class QpackDecoderTest
     @Test
     public void testZeroLengthName()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "00000130";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
@@ -532,11 +545,12 @@ public class QpackDecoderTest
     @Test
     public void testZeroLengthValue() throws Exception
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "00016800";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
-        MetaData metaData = decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData metaData = handler.getMetaData();
         assertThat(metaData.getFields().size(), is(1));
         assertThat(metaData.getFields().get("h"), is(""));
     }
@@ -544,7 +558,7 @@ public class QpackDecoderTest
     @Test
     public void testUpperCaseName()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "0001480130";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
@@ -555,7 +569,7 @@ public class QpackDecoderTest
     @Test
     public void testWhiteSpaceName()
     {
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
 
         String encoded = "0001200130";
         ByteBuffer buffer = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));

jetty-http3/http3-qpack/src/test/java/org/eclipse/jetty/http3/qpack/QpackTest.java

@@ -41,11 +41,13 @@ public class QpackTest
     static final HttpField XPowerJetty = new PreEncodedHttpField(HttpHeader.X_POWERED_BY, "jetty");
     static final HttpField Date = new PreEncodedHttpField(HttpHeader.DATE, DateGenerator.formatDate(TimeUnit.NANOSECONDS.toMillis(System.nanoTime())));
 
+    private final DecoderTestHandler handler = new DecoderTestHandler();
+
     @Test
     public void encodeDecodeResponseTest() throws Exception
     {
         QpackEncoder encoder = new QpackEncoder();
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
         ByteBuffer buffer = BufferUtil.allocateDirect(16 * 1024);
 
         HttpFields.Mutable fields0 = HttpFields.build()
@@ -62,7 +64,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, original0);
         BufferUtil.flipToFlush(buffer, 0);
-        Response decoded0 = (Response)decoder.decode(buffer);
+        decoder.decode(buffer);
+        Response decoded0 = (Response)handler.getMetaData();
 
         Response nullToEmpty = new MetaData.Response(HttpVersion.HTTP_2, 200,
             fields0.put(new HttpField(HttpHeader.CONTENT_ENCODING, "")));
@@ -72,7 +75,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, original0);
         BufferUtil.flipToFlush(buffer, 0);
-        Response decoded0b = (Response)decoder.decode(buffer);
+        decoder.decode(buffer);
+        Response decoded0b = (Response)handler.getMetaData();
 
         assertMetaDataResponseSame(nullToEmpty, decoded0b);
 
@@ -90,7 +94,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, original1);
         BufferUtil.flipToFlush(buffer, 0);
-        Response decoded1 = (Response)decoder.decode(buffer);
+        decoder.decode(buffer);
+        Response decoded1 = (Response)handler.getMetaData();
 
         assertMetaDataResponseSame(original1, decoded1);
         assertEquals("custom-key", decoded1.getFields().getField("Custom-Key").getName());
@@ -100,7 +105,7 @@ public class QpackTest
     public void encodeDecodeTooLargeTest() throws Exception
     {
         QpackEncoder encoder = new QpackEncoder();
-        QpackDecoder decoder = new QpackDecoder(4096, 164);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 164);
         ByteBuffer buffer = BufferUtil.allocateDirect(16 * 1024);
 
         HttpFields fields0 = HttpFields.build()
@@ -111,7 +116,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, original0);
         BufferUtil.flipToFlush(buffer, 0);
-        MetaData decoded0 = decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData decoded0 = handler.getMetaData();
 
         assertMetaDataSame(original0, decoded0);
 
@@ -139,7 +145,7 @@ public class QpackTest
     public void encodeDecodeNonAscii() throws Exception
     {
         QpackEncoder encoder = new QpackEncoder();
-        QpackDecoder decoder = new QpackDecoder(4096, 8192);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 8192);
         ByteBuffer buffer = BufferUtil.allocate(16 * 1024);
 
         HttpFields fields0 = HttpFields.build()
@@ -151,7 +157,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, original0);
         BufferUtil.flipToFlush(buffer, 0);
-        Response decoded0 = (Response)decoder.decode(buffer);
+        decoder.decode(buffer);
+        Response decoded0 = (Response)handler.getMetaData();
 
         assertMetaDataSame(original0, decoded0);
     }
@@ -160,7 +167,7 @@ public class QpackTest
     public void evictReferencedFieldTest() throws Exception
     {
         QpackEncoder encoder = new QpackEncoder(200, 200);
-        QpackDecoder decoder = new QpackDecoder(200, 1024);
+        QpackDecoder decoder = new QpackDecoder(handler, 200, 1024);
         ByteBuffer buffer = BufferUtil.allocateDirect(16 * 1024);
 
         String longEnoughToBeEvicted = "012345678901234567890123456789012345678901234567890";
@@ -173,7 +180,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, original0);
         BufferUtil.flipToFlush(buffer, 0);
-        MetaData decoded0 = decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData decoded0 = handler.getMetaData();
 
         assertEquals(2, encoder.getQpackContext().getNumEntries());
         assertEquals(2, decoder.getQpackContext().getNumEntries());
@@ -190,7 +198,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, original1);
         BufferUtil.flipToFlush(buffer, 0);
-        MetaData decoded1 = decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData decoded1 = handler.getMetaData();
         assertMetaDataSame(original1, decoded1);
 
         assertEquals(2, encoder.getQpackContext().getNumEntries());
@@ -203,7 +212,7 @@ public class QpackTest
     public void testHopHeadersAreRemoved() throws Exception
     {
         QpackEncoder encoder = new QpackEncoder();
-        QpackDecoder decoder = new QpackDecoder(4096, 16384);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 16384);
 
         HttpFields input = HttpFields.build()
             .add(HttpHeader.ACCEPT, "*")
@@ -219,7 +228,8 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, new MetaData(HttpVersion.HTTP_2, input));
         BufferUtil.flipToFlush(buffer, 0);
-        MetaData metaData = decoder.decode(buffer);
+        decoder.decode(buffer);
+        MetaData metaData = handler.getMetaData();
         HttpFields output = metaData.getFields();
 
         assertEquals(1, output.size());
@@ -230,7 +240,7 @@ public class QpackTest
     public void testTETrailers() throws Exception
     {
         QpackEncoder encoder = new QpackEncoder();
-        QpackDecoder decoder = new QpackDecoder(4096, 16384);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 16384);
 
         String teValue = "trailers";
         String trailerValue = "Custom";
@@ -243,7 +253,7 @@ public class QpackTest
         BufferUtil.clearToFill(buffer);
         encoder.encode(buffer, new MetaData(HttpVersion.HTTP_2, input));
         BufferUtil.flipToFlush(buffer, 0);
-        MetaData metaData = decoder.decode(buffer);
+        MetaData metaData = handler.getMetaData();
         HttpFields output = metaData.getFields();
 
         assertEquals(2, output.size());
@@ -255,7 +265,7 @@ public class QpackTest
     public void testColonHeaders() throws Exception
     {
         QpackEncoder encoder = new QpackEncoder();
-        QpackDecoder decoder = new QpackDecoder(4096, 16384);
+        QpackDecoder decoder = new QpackDecoder(handler, 4096, 16384);
 
         HttpFields input = HttpFields.build()
             .add(":status", "200")