chore: refactored UniqueNameBuilder for improved performance (#493)

riok · Jun 13, 2023 · 85347e4 · 85347e4
1 parent 230dffc
commit 85347e4
Show file tree

Hide file tree

Showing 2 changed files with 21 additions and 5 deletions.
diff --git a/src/Riok.Mapperly/Descriptors/Enumerables/EnsureCapacity/EnsureCapacityNonEnumerated.cs b/src/Riok.Mapperly/Descriptors/Enumerables/EnsureCapacity/EnsureCapacityNonEnumerated.cs
@@ -20,6 +20,7 @@ namespace Riok.Mapperly.Descriptors.Enumerables.EnsureCapacity;
 /// </remarks>
 public class EnsureCapacityNonEnumerated : EnsureCapacity
 {
+    private const string SourceCountVariableName = "sourceCount";
     private readonly string _targetAccessor;
     private readonly IMethodSymbol _getNonEnumeratedMethod;
 
@@ -33,7 +34,7 @@ public override StatementSyntax Build(TypeMappingBuildContext ctx, ExpressionSyn
     {
         var targetCount = MemberAccess(target, _targetAccessor);
 
-        var countIdentifier = Identifier(ctx.NameBuilder.New("sourceCount"));
+        var countIdentifier = Identifier(ctx.NameBuilder.New(SourceCountVariableName));
         var countIdentifierName = IdentifierName(countIdentifier);
 
         var enumerableArgument = Argument(ctx.Source);

diff --git a/src/Riok.Mapperly/Helpers/UniqueNameBuilder.cs b/src/Riok.Mapperly/Helpers/UniqueNameBuilder.cs
@@ -3,31 +3,46 @@ namespace Riok.Mapperly.Helpers;
 public class UniqueNameBuilder
 {
     private readonly HashSet<string> _usedNames;
+    private readonly UniqueNameBuilder? _parentScope;
 
     public UniqueNameBuilder()
     {
         _usedNames = new HashSet<string>();
     }
 
-    private UniqueNameBuilder(IEnumerable<string> usedNames)
+    private UniqueNameBuilder(UniqueNameBuilder parentScope)
     {
-        _usedNames = new HashSet<string>(usedNames);
+        _usedNames = new HashSet<string>();
+        _parentScope = parentScope;
     }
 
     public void Reserve(string name) => _usedNames.Add(name);
 
-    public UniqueNameBuilder NewScope() => new(_usedNames);
+    public UniqueNameBuilder NewScope() => new(this);
 
     public string New(string name)
     {
         var i = 0;
         var uniqueName = name;
-        while (!_usedNames.Add(uniqueName))
+        while (Contains(uniqueName))
         {
             i++;
             uniqueName = name + i;
         }
 
+        _usedNames.Add(uniqueName);
+
         return uniqueName;
     }
+
+    private bool Contains(string name)
+    {
+        if (_usedNames.Contains(name))
+            return true;
+
+        if (_parentScope != null)
+            return _parentScope.Contains(name);
+
+        return false;
+    }
 }