Optimized the generation of C# by not splitting any strings.

Our indention of lines in blocks was inadequate so we used to split strings by new lines, indent each line and put it back together. Creation of new strings is incredibly slow so this bogged our code generation down. I have now fixed indention properly and we no longer need to split already written blocks to indent them.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/Generator/Generators/CLI/CLIMarshal.cs

@@ -775,7 +775,7 @@ namespace CppSharp.Generators.CLI
             var fieldRef = string.Format("{0}.{1}", Context.Parameter.Name,
                                          property.Name);
 
-            var marshalCtx = new MarshalContext(Context.Context)
+            var marshalCtx = new MarshalContext(Context.Context, Context.Indent)
                                  {
                                      ArgName = fieldRef,
                                      ParameterIndex = Context.ParameterIndex++,

src/Generator/Generators/CLI/CLISources.cs

@@ -396,7 +396,7 @@ namespace CppSharp.Generators.CLI
                 else
                     variable = $"((::{@class.QualifiedOriginalName}*)NativePtr)->{decl.OriginalName}";
 
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                 {
                     Parameter = param,
                     ArgName = param.Name,
@@ -408,7 +408,7 @@ namespace CppSharp.Generators.CLI
 
                 if (isIndexer)
                 {
-                    var ctx2 = new MarshalContext(Context)
+                    var ctx2 = new MarshalContext(Context, CurrentIndent)
                     {
                         Parameter = indexParameter,
                         ArgName = indexParameter.Name
@@ -483,7 +483,7 @@ namespace CppSharp.Generators.CLI
                     variable = string.Format("((::{0}*)NativePtr)->{1}",
                                              @class.QualifiedOriginalName, decl.OriginalName);
 
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                     {
                         Declaration = decl,
                         ArgName = decl.Name,
@@ -592,7 +592,7 @@ namespace CppSharp.Generators.CLI
             var returns = new List<string>();
             foreach (var param in @event.Parameters)
             {
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                     {
                         ReturnVarName = param.Name,
                         ReturnType = param.QualifiedType
@@ -686,7 +686,7 @@ namespace CppSharp.Generators.CLI
                 var nativeField = string.Format("{0}{1}",
                                                 nativeVar, property.Field.OriginalName);
 
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                 {
                     ArgName = property.Name,
                     ReturnVarName = nativeField,
@@ -834,7 +834,7 @@ namespace CppSharp.Generators.CLI
             var paramIndex = 0;
             foreach (var param in method.Parameters)
             {
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                               {
                                   Function = method,
                                   Parameter = param,
@@ -870,7 +870,7 @@ namespace CppSharp.Generators.CLI
 
                 var varName = string.Format("_native.{0}", property.Field.OriginalName);
 
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                     {
                         ReturnVarName = varName,
                         ReturnType = property.QualifiedType
@@ -946,7 +946,7 @@ namespace CppSharp.Generators.CLI
                 WriteLine("auto {0} = ::{1}();", valueMarshalName, @class.QualifiedOriginalName);
 
                 var param = new Parameter { Name = "(*this)" , Namespace = function.Namespace };
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                     {
                         MarshalVarPrefix = valueMarshalName,
                         Parameter = param
@@ -1021,7 +1021,7 @@ namespace CppSharp.Generators.CLI
 
                 var nativeVarName = paramInfo.Name;
 
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                     {
                         ArgName = nativeVarName,
                         ReturnVarName = nativeVarName,
@@ -1054,7 +1054,7 @@ namespace CppSharp.Generators.CLI
                         isIntPtr ? "System::IntPtr()" : "nullptr");
                 }
 
-                var ctx = new MarshalContext(Context)
+                var ctx = new MarshalContext(Context, CurrentIndent)
                 {
                     ArgName = returnIdentifier,
                     ReturnVarName = returnIdentifier,
@@ -1167,7 +1167,7 @@ namespace CppSharp.Generators.CLI
                 QualifiedType = new QualifiedType(paramType)
             };
 
-            var ctx = new MarshalContext(Context)
+            var ctx = new MarshalContext(Context, CurrentIndent)
             {
                 Parameter = effectiveParam,
                 ParameterIndex = paramIndex,

src/Generator/Generators/CSharp/CSharpMarshal.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using CppSharp.AST;
@@ -10,11 +11,13 @@ namespace CppSharp.Generators.CSharp
 {
     public class CSharpMarshalContext : MarshalContext
     {
-        public CSharpMarshalContext(BindingContext context)
-            : base(context)
+        public CSharpMarshalContext(BindingContext context, Stack<uint> indent)
+            : base(context, indent)
         {
             ArgumentPrefix = new TextGenerator();
+            indent.PushTo(ArgumentPrefix.CurrentIndent);
             Cleanup = new TextGenerator();
+            indent.PushTo(Cleanup.CurrentIndent);
         }
 
         public TextGenerator ArgumentPrefix { get; private set; }
@@ -335,7 +338,7 @@ namespace CppSharp.Generators.CSharp
             if (parameter.Usage == ParameterUsage.Unknown || parameter.IsIn)
                 return base.VisitParameterDecl(parameter);
 
-            var ctx = new CSharpMarshalContext(Context.Context)
+            var ctx = new CSharpMarshalContext(Context.Context, Context.Indent)
             {
                 ReturnType = Context.ReturnType,
                 ReturnVarName = Context.ReturnVarName

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -820,7 +820,7 @@ namespace CppSharp.Generators.CSharp
                 QualifiedType = var.QualifiedType
             };
 
-            var ctx = new CSharpMarshalContext(Context)
+            var ctx = new CSharpMarshalContext(Context, CurrentIndent)
             {
                 Parameter = param,
                 ArgName = param.Name,
@@ -880,38 +880,40 @@ namespace CppSharp.Generators.CSharp
 
         private void GenerateFieldSetter(Field field, Class @class, QualifiedType fieldType)
         {
+            string returnVar;
+            Type type = field.Type.Desugar();
+            var arrayType = type as ArrayType;
+            if (arrayType != null && @class.IsValueType)
+            {
+                returnVar = HandleValueArray(arrayType, field);
+            }
+            else
+            {
+                var name = @class.Layout.Fields.First(f => f.FieldPtr == field.OriginalPtr).Name;
+                var identifier = SafeIdentifier(name);
+                if (@class.IsValueType)
+                    returnVar = $"{Helpers.InstanceField}.{identifier}";
+                else
+                    returnVar = $"(({TypePrinter.PrintNative(@class)}*){Helpers.InstanceIdentifier})->{identifier}";
+            }
+
             var param = new Parameter
             {
                 Name = "value",
                 QualifiedType = field.QualifiedType
             };
 
-            var ctx = new CSharpMarshalContext(Context)
+            var ctx = new CSharpMarshalContext(Context, CurrentIndent)
             {
                 Parameter = param,
                 ArgName = param.Name,
+                ReturnVarName = returnVar
             };
             ctx.PushMarshalKind(MarshalKind.NativeField);
 
             var marshal = new CSharpMarshalManagedToNativePrinter(ctx);
             ctx.Declaration = field;
 
-            Type type = field.Type.Desugar();
-            var arrayType = type as ArrayType;
-
-            if (arrayType != null && @class.IsValueType)
-            {
-                ctx.ReturnVarName = HandleValueArray(arrayType, field);
-            }
-            else
-            {
-                var name = @class.Layout.Fields.First(f => f.FieldPtr == field.OriginalPtr).Name;
-                var identifier = SafeIdentifier(name);
-                if (@class.IsValueType)
-                    ctx.ReturnVarName = $"{Helpers.InstanceField}.{identifier}";
-                else
-                    ctx.ReturnVarName = $"(({TypePrinter.PrintNative(@class)}*){Helpers.InstanceIdentifier})->{identifier}";
-            }
             param.Visit(marshal);
 
             if (!string.IsNullOrWhiteSpace(marshal.Context.Before))
@@ -987,7 +989,7 @@ namespace CppSharp.Generators.CSharp
             function.OriginalReturnType.Type.IsPointerTo(out type);
 
             var @internal = TypePrinter.PrintNative(function.Namespace);
-            var ctx = new CSharpMarshalContext(Context)
+            var ctx = new CSharpMarshalContext(Context, CurrentIndent)
             {
                 Parameter = new Parameter
                 {
@@ -1108,7 +1110,7 @@ namespace CppSharp.Generators.CSharp
 
             TypePrinter.PopContext();
 
-            var ctx = new CSharpMarshalContext(Context)
+            var ctx = new CSharpMarshalContext(Context, CurrentIndent)
             {
                 ArgName = var.Name,
                 ReturnType = new QualifiedType(var.Type)
@@ -1171,12 +1173,18 @@ namespace CppSharp.Generators.CSharp
         private void GenerateFieldGetter(Field field, Class @class, QualifiedType returnType)
         {
             var name = @class.Layout.Fields.First(f => f.FieldPtr == field.OriginalPtr).Name;
-            String returnVar;
+            string returnVar;
+            var arrayType = field.Type.Desugar() as ArrayType;
             if (@class.IsValueType)
-                returnVar = $@"{Helpers.InstanceField}.{SafeIdentifier(name)}";
+            {
+                if (arrayType != null)
+                    returnVar = HandleValueArray(arrayType, field);
+                else
+                    returnVar = $"{Helpers.InstanceField}.{SafeIdentifier(name)}";
+            }
             else
             {
-                returnVar = $@"(({TypePrinter.PrintNative(@class)}*) {Helpers.InstanceIdentifier})->{SafeIdentifier(name)}";
+                returnVar = $"(({TypePrinter.PrintNative(@class)}*) {Helpers.InstanceIdentifier})->{SafeIdentifier(name)}";
                 // Class field getter should return a reference object instead of a copy. Wrapping `returnVar` in
                 // IntPtr ensures that non-copying object constructor is invoked.
                 Class typeClass;
@@ -1185,7 +1193,7 @@ namespace CppSharp.Generators.CSharp
                     returnVar = $"new {CSharpTypePrinter.IntPtrType}(&{returnVar})";
             }
 
-            var ctx = new CSharpMarshalContext(Context)
+            var ctx = new CSharpMarshalContext(Context, CurrentIndent)
             {
                 ArgName = field.Name,
                 Declaration = field,
@@ -1194,11 +1202,6 @@ namespace CppSharp.Generators.CSharp
             };
             ctx.PushMarshalKind(MarshalKind.NativeField);
 
-            var arrayType = field.Type.Desugar() as ArrayType;
-
-            if (arrayType != null && @class.IsValueType)
-                ctx.ReturnVarName = HandleValueArray(arrayType, field);
-
             var marshal = new CSharpMarshalNativeToManagedPrinter(ctx);
             field.QualifiedType.Visit(marshal);
 
@@ -1666,7 +1669,7 @@ namespace CppSharp.Generators.CSharp
                 if (param.Kind == ParameterKind.IndirectReturnType)
                     continue;
 
-                var ctx = new CSharpMarshalContext(Context)
+                var ctx = new CSharpMarshalContext(Context, CurrentIndent)
                 {
                     ReturnType = param.QualifiedType,
                     ReturnVarName = param.Name,
@@ -1723,7 +1726,7 @@ namespace CppSharp.Generators.CSharp
                 };
 
                 // Marshal the managed result to native
-                var ctx = new CSharpMarshalContext(Context)
+                var ctx = new CSharpMarshalContext(Context, CurrentIndent)
                 {
                     ArgName = Helpers.ReturnIdentifier,
                     Parameter = param,
@@ -1901,7 +1904,7 @@ namespace CppSharp.Generators.CSharp
             var returns = new List<string>();
             foreach (var param in @event.Parameters)
             {
-                var ctx = new CSharpMarshalContext(Context)
+                var ctx = new CSharpMarshalContext(Context, CurrentIndent)
                 {
                     ReturnVarName = param.Name,
                     ReturnType = param.QualifiedType
@@ -2853,7 +2856,7 @@ namespace CppSharp.Generators.CSharp
 
             if (needsReturn)
             {
-                var ctx = new CSharpMarshalContext(Context)
+                var ctx = new CSharpMarshalContext(Context, CurrentIndent)
                 {
                     ArgName = Helpers.ReturnIdentifier,
                     ReturnVarName = Helpers.ReturnIdentifier,
@@ -2944,7 +2947,7 @@ namespace CppSharp.Generators.CSharp
 
                 var nativeVarName = paramInfo.Name;
 
-                var ctx = new CSharpMarshalContext(Context)
+                var ctx = new CSharpMarshalContext(Context, CurrentIndent)
                 {
                     Parameter = param,
                     ArgName = nativeVarName,
@@ -3012,7 +3015,7 @@ namespace CppSharp.Generators.CSharp
                 }
             }
 
-            var ctx = new CSharpMarshalContext(Context)
+            var ctx = new CSharpMarshalContext(Context, CurrentIndent)
             {
                 Parameter = param,
                 ParameterIndex = paramIndex,

src/Generator/Generators/Marshal.cs

@@ -1,23 +1,27 @@
 using CppSharp.AST;
+using System.Collections.Generic;
 
 namespace CppSharp.Generators
 {
     public class MarshalContext : TypePrinter
     {
-        public MarshalContext(BindingContext context)
+        public MarshalContext(BindingContext context, Stack<uint> indent)
         {
             Context = context;
             Before = new TextGenerator();
+            indent.PushTo(Before.CurrentIndent);
             Return = new TextGenerator();
+            indent.PushTo(Return.CurrentIndent);
             MarshalVarPrefix = string.Empty;
+            this.Indent = indent;
         }
 
-        public BindingContext Context { get; private set; }
+        public BindingContext Context { get; }
 
         public MarshalPrinter<MarshalContext> MarshalToNative;
 
-        public TextGenerator Before { get; private set; }
-        public TextGenerator Return { get; private set; }
+        public TextGenerator Before { get; }
+        public TextGenerator Return { get; }
 
         public string ReturnVarName { get; set; }
         public QualifiedType ReturnType { get; set; }
@@ -27,11 +31,12 @@ namespace CppSharp.Generators
         public Function Function { get; set; }
 
         public string MarshalVarPrefix { get; set; }
+        public Stack<uint> Indent { get; }
     }
 
     public abstract class MarshalPrinter<T> : AstVisitor where T : MarshalContext
     {
-        public T Context { get; private set; }
+        public T Context { get; }
 
         protected MarshalPrinter(T ctx)
         {

src/Generator/Types/Std/Stdlib.cs

@@ -235,7 +235,7 @@ namespace CppSharp.Types.Std
                     QualifiedType = type
                 };
 
-                var elementCtx = new MarshalContext(ctx.Context)
+                var elementCtx = new MarshalContext(ctx.Context, ctx.Indent)
                                      {
                                          Parameter = param,
                                          ArgName = param.Name,
@@ -280,7 +280,7 @@ namespace CppSharp.Types.Std
                 ctx.ReturnVarName);
             ctx.Before.WriteStartBraceIndent();
             {
-                var elementCtx = new MarshalContext(ctx.Context)
+                var elementCtx = new MarshalContext(ctx.Context, ctx.Indent)
                                      {
                                          ReturnVarName = "_element",
                                          ReturnType = type

src/Generator/Utils/BlockGenerator.cs

@@ -176,8 +176,6 @@ namespace CppSharp
 
         #region ITextGenerator implementation
 
-        public uint Indent { get { return Text.Indent; } }
-
         public void Write(string msg, params object[] args)
         {
             Text.Write(msg, args);
@@ -240,8 +238,9 @@ namespace CppSharp
 
     public abstract class BlockGenerator : ITextGenerator
     {
-        public Block RootBlock { get; private set; }
+        public Block RootBlock { get; }
         public Block ActiveBlock { get; private set; }
+        public Stack<uint> CurrentIndent => ActiveBlock.Text.CurrentIndent;
 
         protected BlockGenerator()
         {
@@ -264,12 +263,7 @@ namespace CppSharp
         public void PushBlock(BlockKind kind = BlockKind.Unknown, object obj = null)
         {
             var block = new Block { Kind = kind, Object = obj };
-            var array = new uint[ActiveBlock.Text.CurrentIndent.Count];
-            ActiveBlock.Text.CurrentIndent.CopyTo(array, 0);
-            foreach (var indent in array.Reverse())
-            {
-                block.Text.CurrentIndent.Push(indent);
-            }
+            CurrentIndent.PushTo(block.Text.CurrentIndent);
             block.Text.IsStartOfLine = ActiveBlock.Text.IsStartOfLine;
             block.Text.NeedsNewLine = ActiveBlock.Text.NeedsNewLine;
             PushBlock(block);
@@ -306,8 +300,6 @@ namespace CppSharp
 
         #region ITextGenerator implementation
 
-        public uint Indent { get { return ActiveBlock.Indent; } }
-
         public void Write(string msg, params object[] args)
         {
             ActiveBlock.Write(msg, args);

src/Generator/Utils/TextGenerator.cs

@@ -7,7 +7,6 @@ namespace CppSharp
 {
     public interface ITextGenerator
     {
-        uint Indent { get; }
         void Write(string msg, params object[] args);
         void WriteLine(string msg, params object[] args);
         void WriteLineIndent(string msg, params object[] args);
@@ -30,11 +29,6 @@ namespace CppSharp
         public bool NeedsNewLine { get; set; }
         public Stack<uint> CurrentIndent { get; } = new Stack<uint>();
 
-        public uint Indent
-        {
-            get { return (uint)CurrentIndent.Sum(u => (int)u); }
-        }
-
         public TextGenerator()
         {
         }
@@ -60,16 +54,13 @@ namespace CppSharp
             if (args.Length > 0)
                 msg = string.Format(msg, args);
 
-            foreach(var line in msg.SplitAndKeep(Environment.NewLine))
-            {
-                if (IsStartOfLine && !string.IsNullOrWhiteSpace(line))
-                    StringBuilder.Append(new string(' ', (int) CurrentIndent.Sum(u => u)));
+            if (IsStartOfLine && !string.IsNullOrWhiteSpace(msg))
+                StringBuilder.Append(new string(' ', (int) CurrentIndent.Sum(u => u)));
 
-                if (line.Length > 0)
-                    IsStartOfLine = line.EndsWith(Environment.NewLine);
+            if (msg.Length > 0)
+                IsStartOfLine = msg.EndsWith(Environment.NewLine);
 
-                StringBuilder.Append(line);
-            }
+            StringBuilder.Append(msg);
         }
 
         public void WriteLine(string msg, params object[] args)

src/Generator/Utils/Utils.cs

@@ -49,13 +49,6 @@ namespace CppSharp
             return str.Trim().Split();
         }
 
-        public static IEnumerable<string> SplitAndKeep(this string s, string seperator)
-        {
-            string[] obj = s.Split(new[] { seperator }, StringSplitOptions.None);
-
-            return obj.Select((t, i) => i == obj.Length - 1 ? t : t + seperator);
-        }
-
         public static string Capitalize(string s)
         {
             // Check for empty string.
@@ -134,6 +127,18 @@ namespace CppSharp
 
             return uri1.MakeRelativeUri(uri2).ToString();
         }
-        
+    }
+
+    public static class CollectionExtensions
+    {
+        public static void PushTo<T>(this Stack<T> source, Stack<T> destination)
+        {
+            var array = new T[source.Count];
+            source.CopyTo(array, 0);
+            foreach (var indent in array.Reverse())
+            {
+                destination.Push(indent);
+            }
+        }
     }
 }