Replace StringBuilderPool with ValueStringBuilder

sebastienros · Dec 7, 2023 · 1a347fd · 1a347fd
1 parent 1c8a9b9
commit 1a347fd
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Showing 15 changed files with 482 additions and 227 deletions.
diff --git a/Jint/Native/Array/ArrayPrototype.cs b/Jint/Native/Array/ArrayPrototype.cs
@@ -1,12 +1,12 @@
 #pragma warning disable CA1859 // Use concrete types when possible for improved performance -- most of prototype methods return JsValue
 
 using System.Linq;
+using System.Text;
 using Jint.Collections;
 using Jint.Native.Iterator;
 using Jint.Native.Number;
 using Jint.Native.Object;
 using Jint.Native.Symbol;
-using Jint.Pooling;
 using Jint.Runtime;
 using Jint.Runtime.Descriptors;
 using Jint.Runtime.Descriptors.Specialized;
@@ -1265,15 +1265,15 @@ static string StringFromJsValue(JsValue value)
                 return s;
             }
 
-            using var sb = StringBuilderPool.Rent();
-            sb.Builder.Append(s);
+            var sb = new ValueStringBuilder(stackalloc char[128]);
+            sb.Append(s);
             for (uint k = 1; k < len; k++)
             {
                 if (sep != "")
                 {
-                    sb.Builder.Append(sep);
+                    sb.Append(sep);
                 }
-                sb.Builder.Append(StringFromJsValue(o.Get(k)));
+                sb.Append(StringFromJsValue(o.Get(k)));
             }
 
             return sb.ToString();

diff --git a/Jint/Native/BigInt/BigIntPrototype.cs b/Jint/Native/BigInt/BigIntPrototype.cs
@@ -1,9 +1,9 @@
 using System.Globalization;
 using System.Numerics;
+using System.Text;
 using Jint.Collections;
 using Jint.Native.Object;
 using Jint.Native.Symbol;
-using Jint.Pooling;
 using Jint.Runtime;
 using Jint.Runtime.Descriptors;
 using Jint.Runtime.Interop;
@@ -114,22 +114,28 @@ private JsValue ToBigIntString(JsValue thisObject, JsValue[] arguments)
             value = -value;
         }
 
-        const string digits = "0123456789abcdefghijklmnopqrstuvwxyz";
+        const string Digits = "0123456789abcdefghijklmnopqrstuvwxyz";
 
-        using var builder = StringBuilderPool.Rent();
-        var sb = builder.Builder;
+        var sb = new ValueStringBuilder(stackalloc char[64]);
 
         for (; value > 0; value /= radixMV)
         {
             var d = (int) (value % radixMV);
-            sb.Append(digits[d]);
+            sb.Append(Digits[d]);
         }
 
+#if NET6_0_OR_GREATER
+        var charArray = sb.Length < 512 ? stackalloc char[sb.Length] : new char[sb.Length];
+        sb.AsSpan().CopyTo(charArray);
+        charArray.Reverse();
+#else
         var charArray = new char[sb.Length];
-        sb.CopyTo(0, charArray, 0, charArray.Length);
+        sb.AsSpan().CopyTo(charArray);
         System.Array.Reverse(charArray);
+#endif
 
-        return (negative ? "-" : "") + new string(charArray);
+        var s = new string(charArray);
+        return negative ? '-' + s : s;
     }
 
     /// <summary>

diff --git a/Jint/Native/Json/JsonParser.cs b/Jint/Native/Json/JsonParser.cs
@@ -5,8 +5,6 @@
 using System.Runtime.InteropServices;
 using System.Text;
 using Esprima;
-using Jint.Native.Object;
-using Jint.Pooling;
 using Jint.Runtime;
 
 namespace Jint.Native.Json
@@ -174,7 +172,7 @@ private string ScanPunctuatorValue(int start, char code)
 
         private Token ScanNumericLiteral(ref State state)
         {
-            var sb = state.TokenBuffer;
+            var sb = new ValueStringBuilder(stackalloc char[128]);
             var start = _index;
             var ch = _source.CharCodeAt(_index);
             var canBeInteger = true;
@@ -249,7 +247,6 @@ private Token ScanNumericLiteral(ref State state)
             }
 
             var number = sb.ToString();
-            sb.Clear();
 
             JsNumber value;
             if (canBeInteger && long.TryParse(number, NumberStyles.Integer, CultureInfo.InvariantCulture, out var longResult) && longResult != -0)
@@ -312,7 +309,7 @@ private Token ScanStringLiteral(ref State state)
             int start = _index;
             ++_index;
 
-            var sb = state.TokenBuffer;
+            var sb = new ValueStringBuilder(stackalloc char[128]);
             while (_index < _length)
             {
                 char ch = _source[_index++];
@@ -383,7 +380,6 @@ private Token ScanStringLiteral(ref State state)
             }
 
             string value = sb.ToString();
-            sb.Clear();
             return CreateToken(Tokens.String, value, '\"', new JsString(value), new TextRange(start, _index));
         }
 
@@ -704,8 +700,7 @@ public JsValue Parse(string code, ParserOptions? options)
             _length = _source.Length;
             _lookahead = null!;
 
-            using var wrapper = StringBuilderPool.Rent();
-            State state = new State(wrapper.Builder);
+            State state = new State();
 
             Peek(ref state);
             JsValue jsv = ParseJsonValue(ref state);
@@ -719,22 +714,9 @@ public JsValue Parse(string code, ParserOptions? options)
             return jsv;
         }
 
+        [StructLayout(LayoutKind.Auto)]
         private ref struct State
         {
-            public State(StringBuilder tokenBuffer)
-            {
-                TokenBuffer = tokenBuffer;
-                CurrentDepth = 0;
-            }
-
-            /// <summary>
-            /// StringBuilder instance which can be used to collect
-            /// characters into a single string. Must only be used
-            /// when no child-parser gets called. Must be cleared
-            /// after usage.
-            /// </summary>
-            public StringBuilder TokenBuffer { get; }
-
             /// <summary>
             /// The current recursion depth
             /// </summary>

diff --git a/Jint/Native/Json/JsonSerializer.cs b/Jint/Native/Json/JsonSerializer.cs
@@ -9,7 +9,6 @@
 using Jint.Native.Object;
 using Jint.Native.Proxy;
 using Jint.Native.String;
-using Jint.Pooling;
 using Jint.Runtime;
 using Jint.Runtime.Descriptors;
 using Jint.Runtime.Interop;
@@ -54,9 +53,9 @@ public JsValue Serialize(JsValue value, JsValue replacer, JsValue space)
             var wrapper = _engine.Realm.Intrinsics.Object.Construct(Arguments.Empty);
             wrapper.DefineOwnProperty(JsString.Empty, new PropertyDescriptor(value, PropertyFlag.ConfigurableEnumerableWritable));
 
-            using var jsonBuilder = StringBuilderPool.Rent();
+            var jsonBuilder = new StringBuilder();
 
-            var target = new SerializerState(jsonBuilder.Builder);
+            var target = new SerializerState(jsonBuilder);
             if (SerializeJSONProperty(JsString.Empty, wrapper, ref target) == SerializeResult.Undefined)
             {
                 return JsValue.Undefined;
@@ -196,7 +195,10 @@ private SerializeResult SerializeJSONProperty(JsValue key, JsValue holder, ref S
                     }
 
                     target.DtoaBuilder.Reset();
-                    NumberPrototype.NumberToString(doubleValue, target.DtoaBuilder, target.Json);
+                    var sb = new ValueStringBuilder(stackalloc char[128]);
+                    NumberPrototype.NumberToString(doubleValue, target.DtoaBuilder, ref sb);
+                    target.Json.Append(sb.ToString());
+
                     return SerializeResult.NotUndefined;
                 }