revert capacity related changes

sebastienros · Aug 10, 2023 · 5ac06b5 · 5ac06b5
1 parent e82b68d
commit 5ac06b5
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Showing 4 changed files with 48 additions and 20 deletions.
diff --git a/src/Esprima/ArrayList.cs b/src/Esprima/ArrayList.cs
@@ -124,12 +124,27 @@ public int Capacity
         {
             AssertUnchanged();
 
-            if (value < (_items?.Length ?? 0))
+            if (value < _count)
             {
                 ThrowArgumentOutOfRangeException(nameof(value), value, null);
             }
-
-            EnsureCapacity(value);
+            else if (value == (_items?.Length ?? 0))
+            {
+                return;
+            }
+            else if (value > 0)
+            {
+                T[] array = new T[value];
+                if (_count > 0)
+                {
+                    Array.Copy(_items, 0, array, 0, _count);
+                }
+                _items = array;
+            }
+            else
+            {
+                _items = null;
+            }
 
             OnChanged();
         }
@@ -213,7 +228,10 @@ public void AddRange(ReadOnlySpan<T> items)
         var oldCount = _count;
         var newCount = oldCount + itemCount;
 
-        EnsureCapacity(newCount);
+        if (Capacity < newCount)
+        {
+            Array.Resize(ref _items, Math.Max(newCount, MinAllocatedCount));
+        }
 
         Debug.Assert(_items is not null);
         items.CopyTo(_items.AsSpan(oldCount, itemCount));
@@ -231,7 +249,12 @@ public void Add(T item)
     {
         AssertUnchanged();
 
-        EnsureCapacity(_count + 1);
+        var capacity = Capacity;
+
+        if (_count == capacity)
+        {
+            Array.Resize(ref _items, Math.Max(capacity * 2, MinAllocatedCount));
+        }
 
         Debug.Assert(_items is not null);
         _items![_count] = item;
@@ -262,7 +285,12 @@ public void Insert(int index, T item)
             ThrowIndexOutOfRangeException<T>();
         }
 
-        EnsureCapacity(_count + 1);
+        var capacity = Capacity;
+
+        if (_count == capacity)
+        {
+            Array.Resize(ref _items, Math.Max(capacity * 2, MinAllocatedCount));
+        }
 
         Debug.Assert(_items is not null);
         Array.Copy(_items, index, _items, index + 1, Count - index);
@@ -327,6 +355,16 @@ public void Yield(out T[]? items, out int count)
         this = default;
     }
 
+    public void TrimExcess(int threshold = MinAllocatedCount)
+    {
+        AssertUnchanged();
+
+        if (Capacity - _count > threshold)
+        {
+            Capacity = _count;
+        }
+    }
+
     /// <remarks>
     /// Items should not be added or removed from the <see cref="ArrayList{T}"/> while the returned <see cref="Span{T}"/> is in use!
     /// </remarks>
@@ -367,18 +405,6 @@ IEnumerator IEnumerable.GetEnumerator()
         return GetEnumerator();
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private void EnsureCapacity(int capacity)
-    {
-        var temp = _items;
-        if (temp is null || temp.Length < capacity)
-        {
-            var minAllocatedCount = temp is null || temp.Length < MinAllocatedCount ? MinAllocatedCount : temp.Length * 2;
-            var newSize = Math.Max(capacity, minAllocatedCount);
-            Array.Resize(ref _items, newSize);
-        }
-    }
-
     /// <remarks>
     /// This implementation does not detect changes to the list
     /// during iteration and therefore the behaviour is undefined

diff --git a/src/Esprima/JavascriptParser.cs b/src/Esprima/JavascriptParser.cs
@@ -50,7 +50,7 @@ public void ReleaseLargeBuffers()
             Decorators.Clear();
             if (Decorators.Capacity > 64)
             {
-                Decorators = new ArrayList<Decorator>(64);
+                Decorators.Capacity = 64;
             }
 
             if (LabelSet.Count > 64)

diff --git a/src/Esprima/Scanner.RegExpParser.cs b/src/Esprima/Scanner.RegExpParser.cs
@@ -185,6 +185,7 @@ public RegExpParseResult Parse()
             }
 
             Debug.Assert(conversionError is null);
+            capturingGroups.TrimExcess();
 
             var options = FlagsToOptions(_flags, compiled: _scanner._regExpParseMode == RegExpParseMode.AdaptToCompiled);
             var matchTimeout = _scanner._regexTimeout;

diff --git a/src/Esprima/Scanner.cs b/src/Esprima/Scanner.cs
@@ -144,7 +144,7 @@ internal void ReleaseLargeBuffers()
         _curlyStack.Clear();
         if (_curlyStack.Capacity > 16)
         {
-            _curlyStack = new ArrayList<string>(16);
+            _curlyStack.Capacity = 16;
         }
 
         _sb.Clear();
@@ -517,6 +517,7 @@ internal ArrayList<Comment> ScanCommentsInternal()
     public ReadOnlySpan<Comment> ScanComments()
     {
         var comments = ScanCommentsInternal();
+        comments.TrimExcess();
         return comments.AsSpan();
     }