Refactor QPACK to use an internal package for non API classes.

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

jetty-http3/http3-qpack/src/main/java/module-info.java

@@ -17,9 +17,6 @@ import org.eclipse.jetty.http3.qpack.QpackFieldPreEncoder;
 module org.eclipse.jetty.http3.qpack
 {
     exports org.eclipse.jetty.http3.qpack;
-    exports org.eclipse.jetty.http3.qpack.table;
-    exports org.eclipse.jetty.http3.qpack.generator;
-    exports org.eclipse.jetty.http3.qpack.parser;
 
     requires transitive org.eclipse.jetty.http;
     requires org.slf4j;

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

@@ -1,108 +0,0 @@
-//
-// ========================================================================
-// 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.nio.ByteBuffer;
-
-import org.eclipse.jetty.util.Utf8StringBuilder;
-
-public class HuffmanDecoder
-{
-    static final char EOS = Huffman.EOS;
-    static final char[] tree = Huffman.tree;
-    static final char[] rowsym = Huffman.rowsym;
-    static final byte[] rowbits = Huffman.rowbits;
-
-    private final Utf8StringBuilder utf8 = new Utf8StringBuilder();
-    private int count = 0;
-    private int node = 0;
-    private int current = 0;
-    private int bits = 0;
-
-    public String decode(ByteBuffer buffer, int length) throws QpackException.CompressionException
-    {
-        for (; count < length; count++)
-        {
-            if (!buffer.hasRemaining())
-                return null;
-
-            int b = buffer.get() & 0xFF;
-            current = (current << 8) | b;
-            bits += 8;
-            while (bits >= 8)
-            {
-                int c = (current >>> (bits - 8)) & 0xFF;
-                node = tree[node * 256 + c];
-                if (rowbits[node] != 0)
-                {
-                    if (rowsym[node] == EOS)
-                    {
-                        reset();
-                        throw new QpackException.CompressionException("EOS in content");
-                    }
-
-                    // terminal node
-                    utf8.append((byte)(0xFF & rowsym[node]));
-                    bits -= rowbits[node];
-                    node = 0;
-                }
-                else
-                {
-                    // non-terminal node
-                    bits -= 8;
-                }
-            }
-        }
-
-        while (bits > 0)
-        {
-            int c = (current << (8 - bits)) & 0xFF;
-            int lastNode = node;
-            node = tree[node * 256 + c];
-
-            if (rowbits[node] == 0 || rowbits[node] > bits)
-            {
-                int requiredPadding = 0;
-                for (int i = 0; i < bits; i++)
-                {
-                    requiredPadding = (requiredPadding << 1) | 1;
-                }
-
-                if ((c >> (8 - bits)) != requiredPadding)
-                    throw new QpackException.CompressionException("Incorrect padding");
-
-                node = lastNode;
-                break;
-            }
-
-            utf8.append((byte)(0xFF & rowsym[node]));
-            bits -= rowbits[node];
-            node = 0;
-        }
-
-        if (node != 0)
-            throw new QpackException.CompressionException("Bad termination");
-
-        return utf8.toString();
-    }
-
-    public void reset()
-    {
-        utf8.reset();
-        count = 0;
-        current = 0;
-        node = 0;
-        bits = 0;
-    }
-}

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

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack;
 
 import org.eclipse.jetty.io.ByteBufferPool;
 

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

@@ -21,15 +21,15 @@ import java.util.List;
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFields;
 import org.eclipse.jetty.http.HttpHeader;
-import org.eclipse.jetty.http3.qpack.generator.InsertCountIncrementInstruction;
+import org.eclipse.jetty.http3.qpack.internal.QpackContext;
-import org.eclipse.jetty.http3.qpack.generator.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.InsertCountIncrementInstruction;
-import org.eclipse.jetty.http3.qpack.generator.SectionAcknowledgmentInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.SectionAcknowledgmentInstruction;
-import org.eclipse.jetty.http3.qpack.parser.DecoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.internal.parser.DecoderInstructionParser;
-import org.eclipse.jetty.http3.qpack.parser.EncodedFieldSection;
+import org.eclipse.jetty.http3.qpack.internal.parser.EncodedFieldSection;
-import org.eclipse.jetty.http3.qpack.parser.NBitIntegerParser;
+import org.eclipse.jetty.http3.qpack.internal.table.DynamicTable;
-import org.eclipse.jetty.http3.qpack.table.DynamicTable;
+import org.eclipse.jetty.http3.qpack.internal.table.Entry;
-import org.eclipse.jetty.http3.qpack.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.table.StaticTable;
-import org.eclipse.jetty.http3.qpack.table.StaticTable;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerParser;
 import org.eclipse.jetty.util.component.Dumpable;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -46,7 +46,6 @@ public class QpackDecoder implements Dumpable
 
     private final Handler _handler;
     private final QpackContext _context;
-    private final MetaDataBuilder _builder;
     private final DecoderInstructionParser _parser;
 
     private final List<EncodedFieldSection> _encodedFieldSections = new ArrayList<>();
@@ -58,12 +57,11 @@ public class QpackDecoder implements Dumpable
     public QpackDecoder(Handler handler, int maxHeaderSize)
     {
         _context = new QpackContext();
-        _builder = new MetaDataBuilder(maxHeaderSize);
         _handler = handler;
         _parser = new DecoderInstructionParser(new DecoderAdapter());
     }
 
-    public QpackContext getQpackContext()
+    QpackContext getQpackContext()
     {
         return _context;
     }
@@ -83,8 +81,8 @@ public class QpackDecoder implements Dumpable
                 LOG.debug(String.format("CtxTbl[%x] decoding %d octets", _context.hashCode(), buffer.remaining()));
 
             // If the buffer is big, don't even think about decoding it
-            if (buffer.remaining() > _builder.getMaxSize())
+            // if (buffer.remaining() > _builder.getMaxSize())
-                throw new QpackException.SessionException("431 Request Header Fields too large");
+                //throw new QpackException.SessionException("431 Request Header Fields too large");
 
             _integerDecoder.setPrefix(8);
             int encodedInsertCount = _integerDecoder.decode(buffer);
@@ -235,6 +233,9 @@ public class QpackDecoder implements Dumpable
         return String.format("QpackDecoder@%x{%s}", hashCode(), _context);
     }
 
+    /**
+     * This delivers notifications from the DecoderInstruction parser directly into the Decoder.
+     */
     class DecoderAdapter implements DecoderInstructionParser.Handler
     {
         @Override

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

@@ -28,14 +28,17 @@ import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpStatus;
 import org.eclipse.jetty.http.PreEncodedHttpField;
-import org.eclipse.jetty.http3.qpack.generator.DuplicateInstruction;
+import org.eclipse.jetty.http3.qpack.internal.EncodableEntry;
-import org.eclipse.jetty.http3.qpack.generator.IndexedNameEntryInstruction;
+import org.eclipse.jetty.http3.qpack.internal.QpackContext;
-import org.eclipse.jetty.http3.qpack.generator.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.StreamInfo;
-import org.eclipse.jetty.http3.qpack.generator.LiteralNameEntryInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.DuplicateInstruction;
-import org.eclipse.jetty.http3.qpack.generator.SetCapacityInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.IndexedNameEntryInstruction;
-import org.eclipse.jetty.http3.qpack.parser.EncoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.internal.instruction.LiteralNameEntryInstruction;
-import org.eclipse.jetty.http3.qpack.table.DynamicTable;
+import org.eclipse.jetty.http3.qpack.internal.instruction.SetCapacityInstruction;
-import org.eclipse.jetty.http3.qpack.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.parser.EncoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.internal.table.DynamicTable;
+import org.eclipse.jetty.http3.qpack.internal.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.io.NullByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
@@ -126,7 +129,7 @@ public class QpackEncoder implements Dumpable
         _parser = new EncoderInstructionParser(new EncoderAdapter());
     }
 
-    public QpackContext getQpackContext()
+    QpackContext getQpackContext()
     {
         return _context;
     }
@@ -302,8 +305,8 @@ public class QpackEncoder implements Dumpable
 
         // Calculate the size required. TODO: it may be more efficient to just use a buffer of MAX_HEADER_SIZE?
         int spaceRequired = 0;
-        spaceRequired += 1 + NBitInteger.octectsNeeded(8, encodedInsertCount);
+        spaceRequired += 1 + NBitIntegerEncoder.octectsNeeded(8, encodedInsertCount);
-        spaceRequired += 1 + NBitInteger.octectsNeeded(7, deltaBase);
+        spaceRequired += 1 + NBitIntegerEncoder.octectsNeeded(7, deltaBase);
         for (EncodableEntry encodableEntry : encodableEntries)
         {
             spaceRequired += encodableEntry.getRequiredSize(base);
@@ -313,9 +316,9 @@ public class QpackEncoder implements Dumpable
         int pos = BufferUtil.flipToFill(buffer);
 
         // Encode the Field Section Prefix into the ByteBuffer.
-        NBitInteger.encode(buffer, 8, encodedInsertCount);
+        NBitIntegerEncoder.encode(buffer, 8, encodedInsertCount);
         buffer.put(signBit ? (byte)0x80 : (byte)0x00);
-        NBitInteger.encode(buffer, 7, deltaBase);
+        NBitIntegerEncoder.encode(buffer, 7, deltaBase);
 
         // Encode the field lines into the ByteBuffer.
         for (EncodableEntry entry : encodableEntries)

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

@@ -19,8 +19,10 @@ import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFieldPreEncoder;
 import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpVersion;
-import org.eclipse.jetty.http3.qpack.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.EncodableEntry;
-import org.eclipse.jetty.http3.qpack.table.StaticTable;
+import org.eclipse.jetty.http3.qpack.internal.QpackContext;
+import org.eclipse.jetty.http3.qpack.internal.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.table.StaticTable;
 import org.eclipse.jetty.util.BufferUtil;
 
 public class QpackFieldPreEncoder implements HttpFieldPreEncoder

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/EncodableEntry.java

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal;
 
 import java.nio.ByteBuffer;
 import java.util.Objects;
@@ -19,35 +19,37 @@ import java.util.Objects;
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.PreEncodedHttpField;
-import org.eclipse.jetty.http3.qpack.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.util.HuffmanEncoder;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 
-abstract class EncodableEntry
+public abstract class EncodableEntry
 {
-    static EncodableEntry getReferencedEntry(Entry entry)
+    public static EncodableEntry getReferencedEntry(Entry entry)
     {
         return new ReferencedEntry(entry);
     }
 
-    static EncodableEntry getNameReferencedEntry(Entry nameEntry, HttpField field, boolean huffman)
+    public static EncodableEntry getNameReferencedEntry(Entry nameEntry, HttpField field, boolean huffman)
     {
         return new ReferencedNameEntry(nameEntry, field, huffman);
     }
 
-    static EncodableEntry getLiteralEntry(HttpField field, boolean huffman)
+    public static EncodableEntry getLiteralEntry(HttpField field, boolean huffman)
     {
         return new LiteralEntry(field, huffman);
     }
 
-    static EncodableEntry getPreEncodedEntry(PreEncodedHttpField httpField)
+    public static EncodableEntry getPreEncodedEntry(PreEncodedHttpField httpField)
     {
         return new PreEncodedEntry(httpField);
     }
 
-    abstract void encode(ByteBuffer buffer, int base);
+    public abstract void encode(ByteBuffer buffer, int base);
 
-    abstract int getRequiredSize(int base);
+    public abstract int getRequiredSize(int base);
 
-    abstract int getRequiredInsertCount();
+    public abstract int getRequiredInsertCount();
 
     private static class ReferencedEntry extends EncodableEntry
     {
@@ -67,21 +69,21 @@ abstract class EncodableEntry
                 // Indexed Field Line with Static Reference.
                 buffer.put((byte)(0x80 | 0x40));
                 int relativeIndex = _entry.getIndex();
-                NBitInteger.encode(buffer, 6, relativeIndex);
+                NBitIntegerEncoder.encode(buffer, 6, relativeIndex);
             }
             else if (_entry.getIndex() < base)
             {
                 // Indexed Field Line with Dynamic Reference.
                 buffer.put((byte)0x80);
                 int relativeIndex = base - (_entry.getIndex() + 1);
-                NBitInteger.encode(buffer, 6, relativeIndex);
+                NBitIntegerEncoder.encode(buffer, 6, relativeIndex);
             }
             else
             {
                 // Indexed Field Line with Post-Base Index.
                 buffer.put((byte)0x10);
                 int relativeIndex =  _entry.getIndex() - base;
-                NBitInteger.encode(buffer, 4, relativeIndex);
+                NBitIntegerEncoder.encode(buffer, 4, relativeIndex);
             }
         }
 
@@ -93,19 +95,19 @@ abstract class EncodableEntry
             {
                 // Indexed Field Line with Static Reference.
                 int relativeIndex = _entry.getIndex();
-                return 1 + NBitInteger.octectsNeeded(6, relativeIndex);
+                return 1 + NBitIntegerEncoder.octectsNeeded(6, relativeIndex);
             }
             else if (_entry.getIndex() < base)
             {
                 // Indexed Field Line with Dynamic Reference.
                 int relativeIndex =  base - (_entry.getIndex() + 1);
-                return 1 + NBitInteger.octectsNeeded(6, relativeIndex);
+                return 1 + NBitIntegerEncoder.octectsNeeded(6, relativeIndex);
             }
             else
             {
                 // Indexed Field Line with Post-Base Index.
                 int relativeIndex = _entry.getIndex() - base;
-                return 1 + NBitInteger.octectsNeeded(4, relativeIndex);
+                return 1 + NBitIntegerEncoder.octectsNeeded(4, relativeIndex);
             }
         }
 
@@ -143,21 +145,21 @@ abstract class EncodableEntry
                 // Literal Field Line with Static Name Reference.
                 buffer.put((byte)(0x40 | allowIntermediary | 0x10));
                 int relativeIndex =  _nameEntry.getIndex();
-                NBitInteger.encode(buffer, 4, relativeIndex);
+                NBitIntegerEncoder.encode(buffer, 4, relativeIndex);
             }
             else if (_nameEntry.getIndex() < base)
             {
                 // Literal Field Line with Dynamic Name Reference.
                 buffer.put((byte)(0x40 | allowIntermediary));
                 int relativeIndex = base - (_nameEntry.getIndex() + 1);
-                NBitInteger.encode(buffer, 4, relativeIndex);
+                NBitIntegerEncoder.encode(buffer, 4, relativeIndex);
             }
             else
             {
                 // Literal Field Line with Post-Base Name Reference.
                 buffer.put(allowIntermediary);
                 int relativeIndex = _nameEntry.getIndex() - base;
-                NBitInteger.encode(buffer, 3, relativeIndex);
+                NBitIntegerEncoder.encode(buffer, 3, relativeIndex);
             }
 
             // Encode the value.
@@ -165,13 +167,13 @@ abstract class EncodableEntry
             if (_huffman)
             {
                 buffer.put((byte)0x80);
-                NBitInteger.encode(buffer, 7, Huffman.octetsNeeded(value));
+                NBitIntegerEncoder.encode(buffer, 7, HuffmanEncoder.octetsNeeded(value));
-                Huffman.encode(buffer, value);
+                HuffmanEncoder.encode(buffer, value);
             }
             else
             {
                 buffer.put((byte)0x00);
-                NBitInteger.encode(buffer, 7, value.length());
+                NBitIntegerEncoder.encode(buffer, 7, value.length());
                 buffer.put(value.getBytes());
             }
         }
@@ -181,8 +183,8 @@ abstract class EncodableEntry
         {
             String value = getValue();
             int relativeIndex =  _nameEntry.getIndex() - base;
-            int valueLength = _huffman ? Huffman.octetsNeeded(value) : value.length();
+            int valueLength = _huffman ? HuffmanEncoder.octetsNeeded(value) : value.length();
-            return 1 + NBitInteger.octectsNeeded(4, relativeIndex) + 1 + NBitInteger.octectsNeeded(7, valueLength) + valueLength;
+            return 1 + NBitIntegerEncoder.octectsNeeded(4, relativeIndex) + 1 + NBitIntegerEncoder.octectsNeeded(7, valueLength) + valueLength;
         }
 
         @Override
@@ -220,20 +222,20 @@ abstract class EncodableEntry
             if (_huffman)
             {
                 buffer.put((byte)(0x28 | allowIntermediary));
-                NBitInteger.encode(buffer, 3, Huffman.octetsNeeded(name));
+                NBitIntegerEncoder.encode(buffer, 3, HuffmanEncoder.octetsNeeded(name));
-                Huffman.encode(buffer, name);
+                HuffmanEncoder.encode(buffer, name);
                 buffer.put((byte)0x80);
-                NBitInteger.encode(buffer, 7, Huffman.octetsNeeded(value));
+                NBitIntegerEncoder.encode(buffer, 7, HuffmanEncoder.octetsNeeded(value));
-                Huffman.encode(buffer, value);
+                HuffmanEncoder.encode(buffer, value);
             }
             else
             {
                 // TODO: What charset should we be using? (this applies to the instruction generators as well).
                 buffer.put((byte)(0x20 | allowIntermediary));
-                NBitInteger.encode(buffer, 3, name.length());
+                NBitIntegerEncoder.encode(buffer, 3, name.length());
                 buffer.put(name.getBytes());
                 buffer.put((byte)0x00);
-                NBitInteger.encode(buffer, 7, value.length());
+                NBitIntegerEncoder.encode(buffer, 7, value.length());
                 buffer.put(value.getBytes());
             }
         }
@@ -243,9 +245,9 @@ abstract class EncodableEntry
         {
             String name = getName();
             String value = getValue();
-            int nameLength = _huffman ? Huffman.octetsNeeded(name) : name.length();
+            int nameLength = _huffman ? HuffmanEncoder.octetsNeeded(name) : name.length();
-            int valueLength = _huffman ? Huffman.octetsNeeded(value) : value.length();
+            int valueLength = _huffman ? HuffmanEncoder.octetsNeeded(value) : value.length();
-            return 2 + NBitInteger.octectsNeeded(3, nameLength) + nameLength + NBitInteger.octectsNeeded(7, valueLength) + valueLength;
+            return 2 + NBitIntegerEncoder.octectsNeeded(3, nameLength) + nameLength + NBitIntegerEncoder.octectsNeeded(7, valueLength) + valueLength;
         }
 
         @Override
@@ -267,6 +269,7 @@ abstract class EncodableEntry
         }
     }
 
+    // TODO: pass in the HTTP version to avoid hard coding HTTP3?
     private static class PreEncodedEntry extends EncodableEntry
     {
         private final PreEncodedHttpField _httpField;

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

@@ -11,12 +11,12 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal;
 
 import org.eclipse.jetty.http.HttpField;
-import org.eclipse.jetty.http3.qpack.table.DynamicTable;
+import org.eclipse.jetty.http3.qpack.internal.table.DynamicTable;
-import org.eclipse.jetty.http3.qpack.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.table.Entry;
-import org.eclipse.jetty.http3.qpack.table.StaticTable;
+import org.eclipse.jetty.http3.qpack.internal.table.StaticTable;
 import org.eclipse.jetty.util.StringUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/StreamInfo.java

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal;
 
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -19,9 +19,9 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Queue;
 
-import org.eclipse.jetty.http3.qpack.table.Entry;
+import org.eclipse.jetty.http3.qpack.internal.table.Entry;
 
-class StreamInfo implements Iterable<StreamInfo.SectionInfo>
+public class StreamInfo implements Iterable<StreamInfo.SectionInfo>
 {
     private final int _streamId;
     private final Queue<SectionInfo> _sectionInfos = new LinkedList<>();

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

@@ -11,11 +11,12 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack.internal.instruction;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.NBitInteger;
+import org.eclipse.jetty.http3.qpack.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 
@@ -36,10 +37,10 @@ public class DuplicateInstruction implements Instruction
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {
-        int size = NBitInteger.octectsNeeded(5, _index) + 1;
+        int size = NBitIntegerEncoder.octectsNeeded(5, _index) + 1;
         ByteBuffer buffer = lease.acquire(size, false);
         buffer.put((byte)0x00);
-        NBitInteger.encode(buffer, 5, _index);
+        NBitIntegerEncoder.encode(buffer, 5, _index);
         BufferUtil.flipToFlush(buffer, 0);
         lease.append(buffer, true);
     }

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

@@ -11,12 +11,13 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack.internal.instruction;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.Huffman;
+import org.eclipse.jetty.http3.qpack.Instruction;
-import org.eclipse.jetty.http3.qpack.NBitInteger;
+import org.eclipse.jetty.http3.qpack.internal.util.HuffmanEncoder;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 
@@ -53,24 +54,24 @@ public class IndexedNameEntryInstruction implements Instruction
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {
-        int size = NBitInteger.octectsNeeded(6, _index) + (_huffman ? Huffman.octetsNeeded(_value) : _value.length()) + 2;
+        int size = NBitIntegerEncoder.octectsNeeded(6, _index) + (_huffman ? HuffmanEncoder.octetsNeeded(_value) : _value.length()) + 2;
         ByteBuffer buffer = lease.acquire(size, false);
 
         // First bit indicates the instruction, second bit is whether it is a dynamic table reference or not.
         buffer.put((byte)(0x80 | (_dynamic ? 0x00 : 0x40)));
-        NBitInteger.encode(buffer, 6, _index);
+        NBitIntegerEncoder.encode(buffer, 6, _index);
 
         // We will not huffman encode the string.
         if (_huffman)
         {
             buffer.put((byte)(0x80));
-            NBitInteger.encode(buffer, 7, Huffman.octetsNeeded(_value));
+            NBitIntegerEncoder.encode(buffer, 7, HuffmanEncoder.octetsNeeded(_value));
-            Huffman.encode(buffer, _value);
+            HuffmanEncoder.encode(buffer, _value);
         }
         else
         {
             buffer.put((byte)(0x00));
-            NBitInteger.encode(buffer, 7, _value.length());
+            NBitIntegerEncoder.encode(buffer, 7, _value.length());
             buffer.put(_value.getBytes());
         }
 

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

@@ -11,11 +11,12 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack.internal.instruction;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.NBitInteger;
+import org.eclipse.jetty.http3.qpack.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 
@@ -31,10 +32,10 @@ public class InsertCountIncrementInstruction implements Instruction
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {
-        int size = NBitInteger.octectsNeeded(6, _increment) + 1;
+        int size = NBitIntegerEncoder.octectsNeeded(6, _increment) + 1;
         ByteBuffer buffer = lease.acquire(size, false);
         buffer.put((byte)0x00);
-        NBitInteger.encode(buffer, 6, _increment);
+        NBitIntegerEncoder.encode(buffer, 6, _increment);
         BufferUtil.flipToFlush(buffer, 0);
         lease.append(buffer, true);
     }

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

@@ -11,12 +11,13 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack.internal.instruction;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.Huffman;
+import org.eclipse.jetty.http3.qpack.Instruction;
-import org.eclipse.jetty.http3.qpack.NBitInteger;
+import org.eclipse.jetty.http3.qpack.internal.util.HuffmanEncoder;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 
@@ -48,33 +49,33 @@ public class LiteralNameEntryInstruction implements Instruction
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {
-        int size = (_huffmanName ? Huffman.octetsNeeded(_name) : _name.length()) +
+        int size = (_huffmanName ? HuffmanEncoder.octetsNeeded(_name) : _name.length()) +
-            (_huffmanValue ? Huffman.octetsNeeded(_value) : _value.length()) + 2;
+            (_huffmanValue ? HuffmanEncoder.octetsNeeded(_value) : _value.length()) + 2;
         ByteBuffer buffer = lease.acquire(size, false);
 
         if (_huffmanName)
         {
             buffer.put((byte)(0x40 | 0x20));
-            NBitInteger.encode(buffer, 5, Huffman.octetsNeeded(_name));
+            NBitIntegerEncoder.encode(buffer, 5, HuffmanEncoder.octetsNeeded(_name));
-            Huffman.encode(buffer, _name);
+            HuffmanEncoder.encode(buffer, _name);
         }
         else
         {
             buffer.put((byte)(0x40));
-            NBitInteger.encode(buffer, 5, _name.length());
+            NBitIntegerEncoder.encode(buffer, 5, _name.length());
             buffer.put(_name.getBytes());
         }
 
         if (_huffmanValue)
         {
             buffer.put((byte)(0x80));
-            NBitInteger.encode(buffer, 7, Huffman.octetsNeeded(_value));
+            NBitIntegerEncoder.encode(buffer, 7, HuffmanEncoder.octetsNeeded(_value));
-            Huffman.encode(buffer, _value);
+            HuffmanEncoder.encode(buffer, _value);
         }
         else
         {
             buffer.put((byte)(0x00));
-            NBitInteger.encode(buffer, 5, _value.length());
+            NBitIntegerEncoder.encode(buffer, 5, _value.length());
             buffer.put(_value.getBytes());
         }
 

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

@@ -11,11 +11,12 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack.internal.instruction;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.NBitInteger;
+import org.eclipse.jetty.http3.qpack.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 
@@ -31,10 +32,10 @@ public class SectionAcknowledgmentInstruction implements Instruction
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {
-        int size = NBitInteger.octectsNeeded(7, _streamId) + 1;
+        int size = NBitIntegerEncoder.octectsNeeded(7, _streamId) + 1;
         ByteBuffer buffer = lease.acquire(size, false);
         buffer.put((byte)0x80);
-        NBitInteger.encode(buffer, 7, _streamId);
+        NBitIntegerEncoder.encode(buffer, 7, _streamId);
         BufferUtil.flipToFlush(buffer, 0);
         lease.append(buffer, true);
     }

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

@@ -11,11 +11,12 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack.internal.instruction;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.NBitInteger;
+import org.eclipse.jetty.http3.qpack.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 
@@ -36,10 +37,10 @@ public class SetCapacityInstruction implements Instruction
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {
-        int size = NBitInteger.octectsNeeded(5, _capacity) + 1;
+        int size = NBitIntegerEncoder.octectsNeeded(5, _capacity) + 1;
         ByteBuffer buffer = lease.acquire(size, false);
         buffer.put((byte)0x20);
-        NBitInteger.encode(buffer, 5, _capacity);
+        NBitIntegerEncoder.encode(buffer, 5, _capacity);
         BufferUtil.flipToFlush(buffer, 0);
         lease.append(buffer, true);
     }

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

@@ -11,11 +11,12 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.generator;
+package org.eclipse.jetty.http3.qpack.internal.instruction;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.NBitInteger;
+import org.eclipse.jetty.http3.qpack.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;
 
@@ -31,10 +32,10 @@ public class StreamCancellationInstruction implements Instruction
     @Override
     public void encode(ByteBufferPool.Lease lease)
     {
-        int size = NBitInteger.octectsNeeded(6, _streamId) + 1;
+        int size = NBitIntegerEncoder.octectsNeeded(6, _streamId) + 1;
         ByteBuffer buffer = lease.acquire(size, false);
         buffer.put((byte)0x40);
-        NBitInteger.encode(buffer, 6, _streamId);
+        NBitIntegerEncoder.encode(buffer, 6, _streamId);
         BufferUtil.flipToFlush(buffer, 0);
         lease.append(buffer, true);
     }

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

@@ -11,11 +11,13 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.parser;
+package org.eclipse.jetty.http3.qpack.internal.parser;
 
 import java.nio.ByteBuffer;
 
 import org.eclipse.jetty.http3.qpack.QpackException;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerParser;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitStringParser;
 
 /**
  * Parses a stream of unframed instructions for the Decoder. These instructions are sent from the remote Encoder.

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

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.parser;
+package org.eclipse.jetty.http3.qpack.internal.parser;
 
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
@@ -19,8 +19,10 @@ import java.util.List;
 
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFields;
-import org.eclipse.jetty.http3.qpack.QpackContext;
 import org.eclipse.jetty.http3.qpack.QpackException;
+import org.eclipse.jetty.http3.qpack.internal.QpackContext;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerParser;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitStringParser;
 
 public class EncodedFieldSection
 {

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

@@ -11,11 +11,12 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.parser;
+package org.eclipse.jetty.http3.qpack.internal.parser;
 
 import java.nio.ByteBuffer;
 
 import org.eclipse.jetty.http3.qpack.QpackException;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerParser;
 
 /**
  * Parses a stream of unframed instructions for the Encoder. These instructions are sent from the remote Decoder.

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

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.table;
+package org.eclipse.jetty.http3.qpack.internal.table;
 
 import java.io.IOException;
 import java.util.ArrayList;

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

@@ -11,11 +11,14 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.table;
+package org.eclipse.jetty.http3.qpack.internal.table;
 
+import java.nio.ByteBuffer;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import org.eclipse.jetty.http.HttpField;
+import org.eclipse.jetty.http3.qpack.internal.util.HuffmanEncoder;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
 import org.eclipse.jetty.util.StringUtil;
 
 public class Entry
@@ -88,7 +91,7 @@ public class Entry
     @Override
     public String toString()
     {
-        return String.format("%s@%x{index=%d, refs=%d, field=\"%s\"}", getClass().getSimpleName(),  hashCode(),
+        return String.format("%s@%x{index=%d, refs=%d, field=\"%s\"}", getClass().getSimpleName(), hashCode(),
             _absoluteIndex, _referenceCount.get(), _field);
     }
 
@@ -101,4 +104,53 @@ public class Entry
     {
         return 32 + StringUtil.getLength(field.getName()) + StringUtil.getLength(field.getValue());
     }
+
+    public static class StaticEntry extends Entry
+    {
+        private final byte[] _huffmanValue;
+        private final byte _encodedField;
+
+        StaticEntry(int index, HttpField field)
+        {
+            super(index, field);
+            String value = field.getValue();
+            if (value != null && value.length() > 0)
+            {
+                int huffmanLen = HuffmanEncoder.octetsNeeded(value);
+                if (huffmanLen < 0)
+                    throw new IllegalStateException("bad value");
+                int lenLen = NBitIntegerEncoder.octectsNeeded(7, huffmanLen);
+                _huffmanValue = new byte[1 + lenLen + huffmanLen];
+                ByteBuffer buffer = ByteBuffer.wrap(_huffmanValue);
+
+                // Indicate Huffman
+                buffer.put((byte)0x80);
+                // Add huffman length
+                NBitIntegerEncoder.encode(buffer, 7, huffmanLen);
+                // Encode value
+                HuffmanEncoder.encode(buffer, value);
+            }
+            else
+                _huffmanValue = null;
+
+            _encodedField = (byte)(0x80 | index);
+        }
+
+        @Override
+        public boolean isStatic()
+        {
+            return true;
+        }
+
+        @Override
+        public byte[] getStaticHuffmanValue()
+        {
+            return _huffmanValue;
+        }
+
+        public byte getEncodedField()
+        {
+            return _encodedField;
+        }
+    }
 }

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

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.table;
+package org.eclipse.jetty.http3.qpack.internal.table;
 
 import java.util.Arrays;
 import java.util.HashMap;
@@ -24,7 +24,7 @@ import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpHeader;
 import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpScheme;
-import org.eclipse.jetty.http3.qpack.StaticTableHttpField;
+import org.eclipse.jetty.http3.qpack.internal.unused.StaticTableHttpField;
 import org.eclipse.jetty.util.Index;
 
 public class StaticTable implements Iterable<Entry>
@@ -135,17 +135,17 @@ public class StaticTable implements Iterable<Entry>
     public static final int STATIC_SIZE = STATIC_TABLE.length - 1;
 
     private final Map<HttpField, Entry> _staticFieldMap = new HashMap<>();
-    private final Index<StaticEntry> _staticNameMap;
+    private final Index<Entry.StaticEntry> _staticNameMap;
-    private final StaticEntry[] _staticTableByHeader = new StaticEntry[HttpHeader.values().length];
+    private final Entry.StaticEntry[] _staticTableByHeader = new Entry.StaticEntry[HttpHeader.values().length];
-    private final StaticEntry[] _staticTable = new StaticEntry[STATIC_TABLE.length];
+    private final Entry.StaticEntry[] _staticTable = new Entry.StaticEntry[STATIC_TABLE.length];
 
     public StaticTable()
     {
-        Index.Builder<StaticEntry> staticNameMapBuilder = new Index.Builder<StaticEntry>().caseSensitive(false);
+        Index.Builder<Entry.StaticEntry> staticNameMapBuilder = new Index.Builder<Entry.StaticEntry>().caseSensitive(false);
         Set<String> added = new HashSet<>();
         for (int i = 0; i < STATIC_TABLE.length; i++)
         {
-            StaticEntry entry = null;
+            Entry.StaticEntry entry = null;
 
             String name = STATIC_TABLE[i][0];
             String value = STATIC_TABLE[i][1];
@@ -159,7 +159,7 @@ public class StaticTable implements Iterable<Entry>
 
                         HttpMethod method = HttpMethod.CACHE.get(value);
                         if (method != null)
-                            entry = new StaticEntry(i, new StaticTableHttpField(header, name, value, method));
+                            entry = new Entry.StaticEntry(i, new StaticTableHttpField(header, name, value, method));
                         break;
                     }
 
@@ -168,13 +168,13 @@ public class StaticTable implements Iterable<Entry>
 
                         HttpScheme scheme = HttpScheme.CACHE.get(value);
                         if (scheme != null)
-                            entry = new StaticEntry(i, new StaticTableHttpField(header, name, value, scheme));
+                            entry = new Entry.StaticEntry(i, new StaticTableHttpField(header, name, value, scheme));
                         break;
                     }
 
                     case C_STATUS:
                     {
-                        entry = new StaticEntry(i, new StaticTableHttpField(header, name, value, value));
+                        entry = new Entry.StaticEntry(i, new StaticTableHttpField(header, name, value, value));
                         break;
                     }
 
@@ -184,7 +184,7 @@ public class StaticTable implements Iterable<Entry>
             }
 
             if (entry == null)
-                entry = new StaticEntry(i, header == null ? new HttpField(STATIC_TABLE[i][0], value) : new HttpField(header, name, value));
+                entry = new Entry.StaticEntry(i, header == null ? new HttpField(STATIC_TABLE[i][0], value) : new HttpField(header, name, value));
 
             _staticTable[i] = entry;
 
@@ -201,7 +201,7 @@ public class StaticTable implements Iterable<Entry>
 
         for (HttpHeader h : HttpHeader.values())
         {
-            StaticEntry entry = _staticNameMap.get(h.asString());
+            Entry.StaticEntry entry = _staticNameMap.get(h.asString());
             if (entry != null)
                 _staticTableByHeader[h.ordinal()] = entry;
         }

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/unused/AuthorityHttpField.java

@@ -11,11 +11,11 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal.unused;
 
 import org.eclipse.jetty.http.HostPortHttpField;
 import org.eclipse.jetty.http.HttpHeader;
-import org.eclipse.jetty.http3.qpack.table.StaticTable;
+import org.eclipse.jetty.http3.qpack.internal.table.StaticTable;
 
 public class AuthorityHttpField extends HostPortHttpField
 {

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/unused/MetaDataBuilder.java

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal.unused;
 
 import org.eclipse.jetty.http.HostPortHttpField;
 import org.eclipse.jetty.http.HttpField;
@@ -21,6 +21,7 @@ import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpScheme;
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.http.MetaData;
+import org.eclipse.jetty.http3.qpack.QpackException;
 import org.eclipse.jetty.http3.qpack.QpackException.SessionException;
 
 public class MetaDataBuilder

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/unused/StaticTableHttpField.java

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal.unused;
 
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpHeader;

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/util/HuffmanDecoder.java

@@ -0,0 +1,122 @@
+//
+// ========================================================================
+// 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.internal.util;
+
+import java.nio.ByteBuffer;
+
+import org.eclipse.jetty.http3.qpack.QpackException;
+import org.eclipse.jetty.util.Utf8StringBuilder;
+
+public class HuffmanDecoder
+{
+    static final char EOS = HuffmanEncoder.EOS;
+    static final char[] tree = HuffmanEncoder.tree;
+    static final char[] rowsym = HuffmanEncoder.rowsym;
+    static final byte[] rowbits = HuffmanEncoder.rowbits;
+
+    private final Utf8StringBuilder _utf8 = new Utf8StringBuilder();
+    private int _length = 0;
+    private int _count = 0;
+    private int _node = 0;
+    private int _current = 0;
+    private int _bits = 0;
+
+    public void setLength(int length)
+    {
+        if (_count != 0)
+            throw new IllegalStateException();
+        _length = length;
+    }
+
+    public String decode(ByteBuffer buffer) throws QpackException.CompressionException
+    {
+        for (; _count < _length; _count++)
+        {
+            if (!buffer.hasRemaining())
+                return null;
+
+            int b = buffer.get() & 0xFF;
+            _current = (_current << 8) | b;
+            _bits += 8;
+            while (_bits >= 8)
+            {
+                int c = (_current >>> (_bits - 8)) & 0xFF;
+                _node = tree[_node * 256 + c];
+                if (rowbits[_node] != 0)
+                {
+                    if (rowsym[_node] == EOS)
+                    {
+                        reset();
+                        throw new QpackException.CompressionException("EOS in content");
+                    }
+
+                    // terminal node
+                    _utf8.append((byte)(0xFF & rowsym[_node]));
+                    _bits -= rowbits[_node];
+                    _node = 0;
+                }
+                else
+                {
+                    // non-terminal node
+                    _bits -= 8;
+                }
+            }
+        }
+
+        while (_bits > 0)
+        {
+            int c = (_current << (8 - _bits)) & 0xFF;
+            int lastNode = _node;
+            _node = tree[_node * 256 + c];
+
+            if (rowbits[_node] == 0 || rowbits[_node] > _bits)
+            {
+                int requiredPadding = 0;
+                for (int i = 0; i < _bits; i++)
+                {
+                    requiredPadding = (requiredPadding << 1) | 1;
+                }
+
+                if ((c >> (8 - _bits)) != requiredPadding)
+                    throw new QpackException.CompressionException("Incorrect padding");
+
+                _node = lastNode;
+                break;
+            }
+
+            _utf8.append((byte)(0xFF & rowsym[_node]));
+            _bits -= rowbits[_node];
+            _node = 0;
+        }
+
+        if (_node != 0)
+        {
+            reset();
+            throw new QpackException.CompressionException("Bad termination");
+        }
+
+        String value = _utf8.toString();
+        reset();
+        return value;
+    }
+
+    public void reset()
+    {
+        _utf8.reset();
+        _count = 0;
+        _current = 0;
+        _node = 0;
+        _bits = 0;
+    }
+}

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/util/HuffmanEncoder.java

@@ -11,13 +11,11 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal.util;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.util.Utf8StringBuilder;
+public class HuffmanEncoder
-
-public class Huffman
 {
 
     // Appendix C: Huffman Codes
@@ -348,77 +346,6 @@ public class Huffman
         }
     }
 
-    public static String decode(ByteBuffer buffer) throws QpackException.CompressionException
-    {
-        return decode(buffer, buffer.remaining());
-    }
-
-    public static String decode(ByteBuffer buffer, int length) throws QpackException.CompressionException
-    {
-        Utf8StringBuilder utf8 = new Utf8StringBuilder(length * 2);
-        int node = 0;
-        int current = 0;
-        int bits = 0;
-
-        for (int i = 0; i < length; i++)
-        {
-            int b = buffer.get() & 0xFF;
-            current = (current << 8) | b;
-            bits += 8;
-            while (bits >= 8)
-            {
-                int c = (current >>> (bits - 8)) & 0xFF;
-                node = tree[node * 256 + c];
-                if (rowbits[node] != 0)
-                {
-                    if (rowsym[node] == EOS)
-                        throw new QpackException.CompressionException("EOS in content");
-
-                    // terminal node
-                    utf8.append((byte)(0xFF & rowsym[node]));
-                    bits -= rowbits[node];
-                    node = 0;
-                }
-                else
-                {
-                    // non-terminal node
-                    bits -= 8;
-                }
-            }
-        }
-
-        while (bits > 0)
-        {
-            int c = (current << (8 - bits)) & 0xFF;
-            int lastNode = node;
-            node = tree[node * 256 + c];
-
-            if (rowbits[node] == 0 || rowbits[node] > bits)
-            {
-                int requiredPadding = 0;
-                for (int i = 0; i < bits; i++)
-                {
-                    requiredPadding = (requiredPadding << 1) | 1;
-                }
-
-                if ((c >> (8 - bits)) != requiredPadding)
-                    throw new QpackException.CompressionException("Incorrect padding");
-
-                node = lastNode;
-                break;
-            }
-
-            utf8.append((byte)(0xFF & rowsym[node]));
-            bits -= rowbits[node];
-            node = 0;
-        }
-
-        if (node != 0)
-            throw new QpackException.CompressionException("Bad termination");
-
-        return utf8.toString();
-    }
-
     public static int octetsNeeded(String s)
     {
         return octetsNeeded(CODES, s);

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/util/NBitIntegerEncoder.java

@@ -11,11 +11,11 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack;
+package org.eclipse.jetty.http3.qpack.internal.util;
 
 import java.nio.ByteBuffer;
 
-public class NBitInteger
+public class NBitIntegerEncoder
 {
     public static int octectsNeeded(int n, int i)
     {
@@ -101,46 +101,4 @@ public class NBitInteger
             }
         }
     }
-
-    public static int decode(ByteBuffer buffer, int n)
-    {
-        if (n == 8)
-        {
-            int nbits = 0xFF;
-
-            int i = buffer.get() & 0xff;
-
-            if (i == nbits)
-            {
-                int m = 1;
-                int b;
-                do
-                {
-                    b = 0xff & buffer.get();
-                    i = i + (b & 127) * m;
-                    m = m * 128;
-                }
-                while ((b & 128) == 128);
-            }
-            return i;
-        }
-
-        int nbits = 0xFF >>> (8 - n);
-
-        int i = buffer.get(buffer.position() - 1) & nbits;
-
-        if (i == nbits)
-        {
-            int m = 1;
-            int b;
-            do
-            {
-                b = 0xff & buffer.get();
-                i = i + (b & 127) * m;
-                m = m * 128;
-            }
-            while ((b & 128) == 128);
-        }
-        return i;
-    }
 }

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/util/NBitIntegerParser.java

@@ -11,7 +11,7 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.parser;
+package org.eclipse.jetty.http3.qpack.internal.util;
 
 import java.nio.ByteBuffer;
 

jetty-http3/http3-qpack/src/main/java/org/eclipse/jetty/http3/qpack/internal/util/NBitStringParser.java

@@ -11,11 +11,10 @@
 // ========================================================================
 //
 
-package org.eclipse.jetty.http3.qpack.parser;
+package org.eclipse.jetty.http3.qpack.internal.util;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.HuffmanDecoder;
 import org.eclipse.jetty.http3.qpack.QpackException;
 
 public class NBitStringParser
@@ -69,10 +68,11 @@ public class NBitStringParser
                     if (_length < 0)
                         return null;
                     _state = State.VALUE;
+                    _huffmanBuilder.setLength(_length);
                     continue;
 
                 case VALUE:
-                    String value = _huffman ? _huffmanBuilder.decode(buffer, _length) : asciiStringDecode(buffer);
+                    String value = _huffman ? _huffmanBuilder.decode(buffer) : asciiStringDecode(buffer);
                     if (value != null)
                         reset();
                     return value;

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

@@ -1,69 +0,0 @@
-//
-// ========================================================================
-// 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.table;
-
-import java.nio.ByteBuffer;
-
-import org.eclipse.jetty.http.HttpField;
-import org.eclipse.jetty.http3.qpack.Huffman;
-import org.eclipse.jetty.http3.qpack.NBitInteger;
-
-public class StaticEntry extends Entry
-{
-    private final byte[] _huffmanValue;
-    private final byte _encodedField;
-
-    StaticEntry(int index, HttpField field)
-    {
-        super(index, field);
-        String value = field.getValue();
-        if (value != null && value.length() > 0)
-        {
-            int huffmanLen = Huffman.octetsNeeded(value);
-            if (huffmanLen < 0)
-                throw new IllegalStateException("bad value");
-            int lenLen = NBitInteger.octectsNeeded(7, huffmanLen);
-            _huffmanValue = new byte[1 + lenLen + huffmanLen];
-            ByteBuffer buffer = ByteBuffer.wrap(_huffmanValue);
-
-            // Indicate Huffman
-            buffer.put((byte)0x80);
-            // Add huffman length
-            NBitInteger.encode(buffer, 7, huffmanLen);
-            // Encode value
-            Huffman.encode(buffer, value);
-        }
-        else
-            _huffmanValue = null;
-
-        _encodedField = (byte)(0x80 | index);
-    }
-
-    @Override
-    public boolean isStatic()
-    {
-        return true;
-    }
-
-    @Override
-    public byte[] getStaticHuffmanValue()
-    {
-        return _huffmanValue;
-    }
-
-    public byte getEncodedField()
-    {
-        return _encodedField;
-    }
-}

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

@@ -17,7 +17,7 @@ import java.nio.ByteBuffer;
 import java.util.LinkedList;
 import java.util.Queue;
 
-import org.eclipse.jetty.http3.qpack.parser.DecoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.internal.parser.DecoderInstructionParser;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.TypeUtil;
 import org.junit.jupiter.api.BeforeEach;

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

@@ -17,14 +17,13 @@ import java.nio.ByteBuffer;
 
 import org.eclipse.jetty.http.HttpField;
 import org.eclipse.jetty.http.HttpFields;
-import org.eclipse.jetty.http3.qpack.generator.IndexedNameEntryInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.IndexedNameEntryInstruction;
-import org.eclipse.jetty.http3.qpack.generator.InsertCountIncrementInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.InsertCountIncrementInstruction;
-import org.eclipse.jetty.http3.qpack.generator.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.LiteralNameEntryInstruction;
-import org.eclipse.jetty.http3.qpack.generator.LiteralNameEntryInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.SectionAcknowledgmentInstruction;
-import org.eclipse.jetty.http3.qpack.generator.SectionAcknowledgmentInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.SetCapacityInstruction;
-import org.eclipse.jetty.http3.qpack.generator.SetCapacityInstruction;
+import org.eclipse.jetty.http3.qpack.internal.parser.DecoderInstructionParser;
-import org.eclipse.jetty.http3.qpack.parser.DecoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.internal.parser.EncoderInstructionParser;
-import org.eclipse.jetty.http3.qpack.parser.EncoderInstructionParser;
 import org.eclipse.jetty.util.BufferUtil;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;

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

@@ -17,7 +17,7 @@ import java.nio.ByteBuffer;
 import java.util.LinkedList;
 import java.util.Queue;
 
-import org.eclipse.jetty.http3.qpack.parser.EncoderInstructionParser;
+import org.eclipse.jetty.http3.qpack.internal.parser.EncoderInstructionParser;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.TypeUtil;
 import org.junit.jupiter.api.Disabled;

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

@@ -18,6 +18,8 @@ import java.nio.ByteBuffer;
 import java.util.Locale;
 import java.util.stream.Stream;
 
+import org.eclipse.jetty.http3.qpack.internal.util.HuffmanDecoder;
+import org.eclipse.jetty.http3.qpack.internal.util.HuffmanEncoder;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.TypeUtil;
 import org.hamcrest.Matchers;
@@ -51,7 +53,9 @@ public class HuffmanTest
     public void testDecode(String specSection, String hex, String expected) throws Exception
     {
         byte[] encoded = TypeUtil.fromHexString(hex);
-        String decoded = Huffman.decode(ByteBuffer.wrap(encoded));
+        HuffmanDecoder huffmanDecoder = new HuffmanDecoder();
+        huffmanDecoder.setLength(encoded.length);
+        String decoded = huffmanDecoder.decode(ByteBuffer.wrap(encoded));
         assertEquals(expected, decoded, specSection);
     }
 
@@ -61,11 +65,11 @@ public class HuffmanTest
     {
         ByteBuffer buf = BufferUtil.allocate(1024);
         int pos = BufferUtil.flipToFill(buf);
-        Huffman.encode(buf, expected);
+        HuffmanEncoder.encode(buf, expected);
         BufferUtil.flipToFlush(buf, pos);
         String encoded = TypeUtil.toHexString(BufferUtil.toArray(buf)).toLowerCase(Locale.ENGLISH);
         assertEquals(hex, encoded, specSection);
-        assertEquals(hex.length() / 2, Huffman.octetsNeeded(expected));
+        assertEquals(hex.length() / 2, HuffmanEncoder.octetsNeeded(expected));
     }
 
     @ParameterizedTest(name = "[{index}]") // don't include unprintable character in test display-name
@@ -74,9 +78,9 @@ public class HuffmanTest
     {
         String s = "bad '" + bad + "'";
 
-        assertThat(Huffman.octetsNeeded(s), Matchers.is(-1));
+        assertThat(HuffmanEncoder.octetsNeeded(s), Matchers.is(-1));
 
         assertThrows(BufferOverflowException.class,
-            () -> Huffman.encode(BufferUtil.allocate(32), s));
+            () -> HuffmanEncoder.encode(BufferUtil.allocate(32), s));
     }
 }

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

@@ -13,9 +13,8 @@
 
 package org.eclipse.jetty.http3.qpack;
 
-import org.eclipse.jetty.http3.qpack.generator.IndexedNameEntryInstruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.IndexedNameEntryInstruction;
-import org.eclipse.jetty.http3.qpack.generator.Instruction;
+import org.eclipse.jetty.http3.qpack.internal.instruction.SectionAcknowledgmentInstruction;
-import org.eclipse.jetty.http3.qpack.generator.SectionAcknowledgmentInstruction;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.io.MappedByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;

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

@@ -15,7 +15,7 @@ package org.eclipse.jetty.http3.qpack;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.parser.NBitIntegerParser;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerParser;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.TypeUtil;
 import org.junit.jupiter.api.Test;

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

@@ -15,6 +15,8 @@ package org.eclipse.jetty.http3.qpack;
 
 import java.nio.ByteBuffer;
 
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerEncoder;
+import org.eclipse.jetty.http3.qpack.internal.util.NBitIntegerParser;
 import org.eclipse.jetty.util.BufferUtil;
 import org.eclipse.jetty.util.TypeUtil;
 import org.junit.jupiter.api.Test;
@@ -24,21 +26,22 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 @SuppressWarnings("PointlessArithmeticExpression")
 public class NBitIntegerTest
 {
+    private final NBitIntegerParser _parser = new NBitIntegerParser();
 
     @Test
     public void testOctetsNeeded()
     {
-        assertEquals(0, NBitInteger.octectsNeeded(5, 10));
+        assertEquals(0, NBitIntegerEncoder.octectsNeeded(5, 10));
-        assertEquals(2, NBitInteger.octectsNeeded(5, 1337));
+        assertEquals(2, NBitIntegerEncoder.octectsNeeded(5, 1337));
-        assertEquals(1, NBitInteger.octectsNeeded(8, 42));
+        assertEquals(1, NBitIntegerEncoder.octectsNeeded(8, 42));
-        assertEquals(3, NBitInteger.octectsNeeded(8, 1337));
+        assertEquals(3, NBitIntegerEncoder.octectsNeeded(8, 1337));
 
-        assertEquals(0, NBitInteger.octectsNeeded(6, 62));
+        assertEquals(0, NBitIntegerEncoder.octectsNeeded(6, 62));
-        assertEquals(1, NBitInteger.octectsNeeded(6, 63));
+        assertEquals(1, NBitIntegerEncoder.octectsNeeded(6, 63));
-        assertEquals(1, NBitInteger.octectsNeeded(6, 64));
+        assertEquals(1, NBitIntegerEncoder.octectsNeeded(6, 64));
-        assertEquals(2, NBitInteger.octectsNeeded(6, 63 + 0x00 + 0x80 * 0x01));
+        assertEquals(2, NBitIntegerEncoder.octectsNeeded(6, 63 + 0x00 + 0x80 * 0x01));
-        assertEquals(3, NBitInteger.octectsNeeded(6, 63 + 0x00 + 0x80 * 0x80));
+        assertEquals(3, NBitIntegerEncoder.octectsNeeded(6, 63 + 0x00 + 0x80 * 0x80));
-        assertEquals(4, NBitInteger.octectsNeeded(6, 63 + 0x00 + 0x80 * 0x80 * 0x80));
+        assertEquals(4, NBitIntegerEncoder.octectsNeeded(6, 63 + 0x00 + 0x80 * 0x80 * 0x80));
     }
 
     @Test
@@ -79,12 +82,12 @@ public class NBitIntegerTest
         int p = BufferUtil.flipToFill(buf);
         if (n < 8)
             buf.put((byte)0x00);
-        NBitInteger.encode(buf, n, i);
+        NBitIntegerEncoder.encode(buf, n, i);
         BufferUtil.flipToFlush(buf, p);
         String r = TypeUtil.toHexString(BufferUtil.toArray(buf));
         assertEquals(expected, r);
 
-        assertEquals(expected.length() / 2, (n < 8 ? 1 : 0) + NBitInteger.octectsNeeded(n, i));
+        assertEquals(expected.length() / 2, (n < 8 ? 1 : 0) + NBitIntegerEncoder.octectsNeeded(n, i));
     }
 
     @Test
@@ -122,8 +125,8 @@ public class NBitIntegerTest
     public void testDecode(int n, int expected, String encoded)
     {
         ByteBuffer buf = ByteBuffer.wrap(TypeUtil.fromHexString(encoded));
-        buf.position(n == 8 ? 0 : 1);
+        _parser.setPrefix(n);
-        assertEquals(expected, NBitInteger.decode(buf, n));
+        assertEquals(expected, _parser.decode(buf));
     }
 
     @Test
@@ -133,7 +136,7 @@ public class NBitIntegerTest
         int p = BufferUtil.flipToFill(buf);
         buf.put((byte)0x77);
         buf.put((byte)0xFF);
-        NBitInteger.encode(buf, 5, 10);
+        NBitIntegerEncoder.encode(buf, 5, 10);
         BufferUtil.flipToFlush(buf, p);
 
         String r = TypeUtil.toHexString(BufferUtil.toArray(buf));
@@ -145,9 +148,9 @@ public class NBitIntegerTest
     public void testDecodeExampleD11()
     {
         ByteBuffer buf = ByteBuffer.wrap(TypeUtil.fromHexString("77EaFF"));
-        buf.position(2);
+        buf.position(1);
-
+        _parser.setPrefix(5);
-        assertEquals(10, NBitInteger.decode(buf, 5));
+        assertEquals(10, _parser.decode(buf));
     }
 
     @Test
@@ -157,7 +160,7 @@ public class NBitIntegerTest
         int p = BufferUtil.flipToFill(buf);
         buf.put((byte)0x88);
         buf.put((byte)0x00);
-        NBitInteger.encode(buf, 5, 1337);
+        NBitIntegerEncoder.encode(buf, 5, 1337);
         BufferUtil.flipToFlush(buf, p);
 
         String r = TypeUtil.toHexString(BufferUtil.toArray(buf));
@@ -169,9 +172,9 @@ public class NBitIntegerTest
     public void testDecodeExampleD12()
     {
         ByteBuffer buf = ByteBuffer.wrap(TypeUtil.fromHexString("881f9a0aff"));
-        buf.position(2);
+        buf.position(1);
-
+        _parser.setPrefix(5);
-        assertEquals(1337, NBitInteger.decode(buf, 5));
+        assertEquals(1337, _parser.decode(buf));
     }
 
     @Test
@@ -181,7 +184,7 @@ public class NBitIntegerTest
         int p = BufferUtil.flipToFill(buf);
         buf.put((byte)0x88);
         buf.put((byte)0xFF);
-        NBitInteger.encode(buf, 8, 42);
+        NBitIntegerEncoder.encode(buf, 8, 42);
         BufferUtil.flipToFlush(buf, p);
 
         String r = TypeUtil.toHexString(BufferUtil.toArray(buf));
@@ -194,7 +197,7 @@ public class NBitIntegerTest
     {
         ByteBuffer buf = ByteBuffer.wrap(TypeUtil.fromHexString("882aFf"));
         buf.position(1);
-
+        _parser.setPrefix(8);
-        assertEquals(42, NBitInteger.decode(buf, 8));
+        assertEquals(42, _parser.decode(buf));
     }
 }

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

@@ -15,7 +15,6 @@ package org.eclipse.jetty.http3.qpack;
 
 import java.nio.ByteBuffer;
 
-import org.eclipse.jetty.http3.qpack.generator.Instruction;
 import org.eclipse.jetty.io.ByteBufferPool;
 import org.eclipse.jetty.io.NullByteBufferPool;
 import org.eclipse.jetty.util.BufferUtil;

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

@@ -17,7 +17,6 @@ import java.util.LinkedList;
 import java.util.Queue;
 
 import org.eclipse.jetty.http.HttpFields;
-import org.eclipse.jetty.http3.qpack.generator.Instruction;
 
 public class TestDecoderHandler implements QpackDecoder.Handler
 {

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

@@ -16,8 +16,6 @@ package org.eclipse.jetty.http3.qpack;
 import java.util.LinkedList;
 import java.util.Queue;
 
-import org.eclipse.jetty.http3.qpack.generator.Instruction;
-
 public class TestEncoderHandler implements QpackEncoder.Handler
 {
     private final Queue<Instruction> _instructionList = new LinkedList<>();