Add HPack dynamic compression

Author: JamesNK

src/Servers/Kestrel/Core/ref/Microsoft.AspNetCore.Server.Kestrel.Core.netcoreapp.cs

@@ -130,6 +130,7 @@ public KestrelServerOptions() { }
         public bool AllowSynchronousIO { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute] set { } }
         public System.IServiceProvider ApplicationServices { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute] set { } }
         public Microsoft.AspNetCore.Server.Kestrel.KestrelConfigurationLoader ConfigurationLoader { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute] set { } }
+        public bool DisableResponseDynamicHeaderCompression { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute] set { } }
         public bool DisableStringReuse { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute] set { } }
         public bool EnableAltSvc { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } [System.Runtime.CompilerServices.CompilerGeneratedAttribute] set { } }
         public Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerLimits Limits { [System.Runtime.CompilerServices.CompilerGeneratedAttribute] get { throw null; } }

src/Servers/Kestrel/Core/src/CoreStrings.resx

@@ -599,4 +599,7 @@ For more information on configuring HTTPS see https://go.microsoft.com/fwlink/?l
   <data name="TransportNotFound" xml:space="preserve">
     <value>Unable to resolve service for type 'Microsoft.AspNetCore.Connections.IConnectionListenerFactory' while attempting to activate 'Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer'.</value>
   </data>
+  <data name="GreaterThanOrEqualToZeroRequired" xml:space="preserve">
+    <value>A value greater than or equal to zero is required.</value>
+  </data>
 </root>

src/Servers/Kestrel/Core/src/Http2Limits.cs

@@ -39,19 +39,19 @@ public int MaxStreamsPerConnection
         }
 
         /// <summary>
-        /// Limits the size of the header compression table, in octets, the HPACK decoder on the server can use.
+        /// Limits the size of the header compression tables, in octets, the HPACK encoder and decoder on the server can use.
         /// <para>
-        /// Value must be greater than 0, defaults to 4096
+        /// Value must be greater than or equal to 0, defaults to 4096
         /// </para>
         /// </summary>
         public int HeaderTableSize
         {
             get => _headerTableSize;
             set
             {
-                if (value <= 0)
+                if (value < 0)
                 {
-                    throw new ArgumentOutOfRangeException(nameof(value), value, CoreStrings.GreaterThanZeroRequired);
+                    throw new ArgumentOutOfRangeException(nameof(value), value, CoreStrings.GreaterThanOrEqualToZeroRequired);
                 }
 
                 _headerTableSize = value;

src/Servers/Kestrel/Core/src/Internal/Http2/HPack/HPackHeaderEntry.cs

@@ -0,0 +1,74 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics;
+using System.Net.Http.HPack;
+
+namespace Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2.HPack
+{
+    [DebuggerDisplay("Name = {Name} Value = {Value}")]
+    internal class HPackHeaderEntry
+    {
+        // Header name and value
+        public string Name;
+        public string Value;
+
+        // Chained list of headers in the same bucket
+        public HPackHeaderEntry Next;
+        public int Hash;
+
+        // Compute dynamic table index
+        public int Index;
+
+        // Doubly linked list
+        public HPackHeaderEntry Before;
+        public HPackHeaderEntry After;
+
+        /// <summary>
+        /// Initialize header values. An entry will be reinitialized when reused.
+        /// </summary>
+        public void Initialize(int hash, string name, string value, int index, HPackHeaderEntry next)
+        {
+            Debug.Assert(name != null);
+            Debug.Assert(value != null);
+
+            Name = name;
+            Value = value;
+            Index = index;
+            Hash = hash;
+            Next = next;
+        }
+
+        public uint CalculateSize()
+        {
+            return (uint)HeaderField.GetLength(Name.Length, Value.Length);
+        }
+
+        /// <summary>
+        /// Remove entry from the linked list and reset header values.
+        /// </summary>
+        public void Remove()
+        {
+            Before.After = After;
+            After.Before = Before;
+            Before = null;
+            After = null;
+            Next = null;
+            Hash = 0;
+            Name = null;
+            Value = null;
+        }
+
+        /// <summary>
+        /// Add before an entry in the linked list.
+        /// </summary>
+        public void AddBefore(HPackHeaderEntry existingEntry)
+        {
+            After = existingEntry;
+            Before = existingEntry.Before;
+            Before.After = this;
+            After.Before = this;
+        }
+    }
+}