PPTC & Pool Enhancements. (#1968)

* PPTC & Pool Enhancements.

* Avoid buffer allocations in CodeGenContext.GetCode(). Avoid stream allocations in PTC.PtcInfo.

Refactoring/nits.

* Use XXHash128, for Ptc.Load & Ptc.Save, x10 faster than Md5.

* Why not a nice Span.

* Added a simple PtcFormatter library for deserialization/serialization, which does not require reflection, in use at PtcJumpTable and PtcProfiler; improves maintainability and simplicity/readability of affected code.

* Nits.

* Revert #1987.

* Revert "Revert #1987."

This reverts commit 998be765cf7f7da5ff0c1c08de704c9012b0f49c.

ARMeilleure/Translation/PTC/PtcFormatter.cs

@@ -0,0 +1,121 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace ARMeilleure.Translation.PTC
+{
+    public class PtcFormatter
+    {
+        #region "Deserialize"
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static Dictionary<TKey, TValue> DeserializeDictionary<TKey, TValue>(Stream stream, Func<Stream, TValue> valueFunc) where TKey : unmanaged
+        {
+            Dictionary<TKey, TValue> dictionary = new();
+
+            int count = DeserializeStructure<int>(stream);
+
+            for (int i = 0; i < count; i++)
+            {
+                TKey key = DeserializeStructure<TKey>(stream);
+                TValue value = valueFunc(stream);
+
+                dictionary.Add(key, value);
+            }
+
+            return dictionary;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static List<T> DeserializeList<T>(Stream stream) where T : unmanaged
+        {
+            List<T> list = new();
+
+            int count = DeserializeStructure<int>(stream);
+
+            for (int i = 0; i < count; i++)
+            {
+                T item = DeserializeStructure<T>(stream);
+
+                list.Add(item);
+            }
+
+            return list;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T DeserializeStructure<T>(Stream stream) where T : unmanaged
+        {
+            T structure = default(T);
+
+            Span<T> spanT = MemoryMarshal.CreateSpan(ref structure, 1);
+            stream.Read(MemoryMarshal.AsBytes(spanT));
+
+            return structure;
+        }
+        #endregion
+
+        #region "GetSerializeSize"
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetSerializeSizeDictionary<TKey, TValue>(Dictionary<TKey, TValue> dictionary, Func<TValue, int> valueFunc) where TKey : unmanaged
+        {
+            int size = 0;
+
+            size += Unsafe.SizeOf<int>();
+
+            foreach ((_, TValue value) in dictionary)
+            {
+                size += Unsafe.SizeOf<TKey>();
+                size += valueFunc(value);
+            }
+
+            return size;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int GetSerializeSizeList<T>(List<T> list) where T : unmanaged
+        {
+            int size = 0;
+
+            size += Unsafe.SizeOf<int>();
+
+            size += list.Count * Unsafe.SizeOf<T>();
+
+            return size;
+        }
+        #endregion
+
+        #region "Serialize"
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void SerializeDictionary<TKey, TValue>(Stream stream, Dictionary<TKey, TValue> dictionary, Action<Stream, TValue> valueAction) where TKey : unmanaged
+        {
+            SerializeStructure<int>(stream, dictionary.Count);
+
+            foreach ((TKey key, TValue value) in dictionary)
+            {
+                SerializeStructure<TKey>(stream, key);
+                valueAction(stream, value);
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void SerializeList<T>(Stream stream, List<T> list) where T : unmanaged
+        {
+            SerializeStructure<int>(stream, list.Count);
+
+            foreach (T item in list)
+            {
+                SerializeStructure<T>(stream, item);
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static void SerializeStructure<T>(Stream stream, T structure) where T : unmanaged
+        {
+            Span<T> spanT = MemoryMarshal.CreateSpan(ref structure, 1);
+            stream.Write(MemoryMarshal.AsBytes(spanT));
+        }
+        #endregion
+    }
+}