[Parser] Implemented own seekable stream reader.

ICSharpCode.NRefactory.CSharp/ICSharpCode.NRefactory.CSharp.csproj

@@ -400,6 +400,7 @@
     <Compile Include="Refactoring\CodeActions\ExtractFieldAction.cs" />
     <Compile Include="Completion\ICompletionContextProvider.cs" />
     <Compile Include="Refactoring\CodeActions\ExtractMethod\VariableUsageAnalyzation.cs" />
+    <Compile Include="Parser\SeekableStreamReader.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\ICSharpCode.NRefactory\ICSharpCode.NRefactory.csproj">

ICSharpCode.NRefactory.CSharp/Parser/CSharpParser.cs

@@ -3709,25 +3709,9 @@ namespace ICSharpCode.NRefactory.CSharp
 			get { return errorReportPrinter.Errors; }
 		}
 		
-		public SyntaxTree Parse (ITextSource textSource, string fileName, int lineModifier = 0)
-		{
-			return Parse (textSource.CreateReader (), fileName, lineModifier);
-		}
-		
 		public SyntaxTree Parse (TextReader reader, string fileName, int lineModifier = 0)
 		{
-			// TODO: can we optimize this to avoid the text->stream->text roundtrip?
-			using (MemoryStream stream = new MemoryStream ()) {
-				StreamWriter w = new StreamWriter (stream, Encoding.UTF8);
-				char[] buffer = new char[2048];
-				int read;
-				while ((read = reader.ReadBlock(buffer, 0, buffer.Length)) > 0)
-					w.Write (buffer, 0, read);
-				w.Flush (); // we can't close the StreamWriter because that would also close the MemoryStream
-				stream.Position = 0;
-				
-				return Parse (stream, fileName, lineModifier);
-			}
+			return Parse(new StringTextSource (reader.ReadToEnd ()), fileName, lineModifier);
 		}
 
 		public SyntaxTree Parse(CompilerCompilationUnit top, string fileName, int lineModifier = 0)
@@ -3771,18 +3755,23 @@ namespace ICSharpCode.NRefactory.CSharp
 		
 		public SyntaxTree Parse (string program, string fileName)
 		{
-			return Parse (new StringReader (program), fileName);
+			return Parse (new StringTextSource (program), fileName);
 		}
 		
 		internal static object parseLock = new object ();
+
+		public SyntaxTree Parse (Stream stream, string fileName, int lineModifier = 0)
+		{
+			return Parse (new StreamReader (stream), fileName, lineModifier);
+		}
 		
-		public SyntaxTree Parse(Stream stream, string fileName, int lineModifier = 0)
+		public SyntaxTree Parse(ITextSource src, string fileName, int lineModifier = 0)
 		{
 			lock (parseLock) {
 				errorReportPrinter = new ErrorReportPrinter ("");
 				var ctx = new CompilerContext (compilerSettings.ToMono(), errorReportPrinter);
 				ctx.Settings.TabSize = 1;
-				var reader = new SeekableStreamReader (stream, Encoding.UTF8);
+				var reader = new SeekableStreamReader (src);
 				var file = new SourceFile (fileName, fileName, 0);
 				Location.Initialize (new List<SourceFile> (new [] { file }));
 				var module = new ModuleContainer (ctx);
@@ -3885,8 +3874,7 @@ namespace ICSharpCode.NRefactory.CSharp
 				errorReportPrinter = new ErrorReportPrinter("");
 				var ctx = new CompilerContext(compilerSettings.ToMono(), errorReportPrinter);
 				ctx.Settings.TabSize = 1;
-				var stream = new MemoryStream(Encoding.Unicode.GetBytes(cref));
-				var reader = new SeekableStreamReader(stream, Encoding.Unicode);
+				var reader = new SeekableStreamReader(new StringTextSource (cref));
 				var file = new SourceFile("", "", 0);
 				Location.Initialize(new List<SourceFile> (new [] { file }));
 				var module = new ModuleContainer(ctx);

ICSharpCode.NRefactory.CSharp/Parser/SeekableStreamReader.cs

@@ -0,0 +1,98 @@
+//
+// SeekableStreamReader.cs
+//
+// Author:
+//       Mike Krüger <mkrueger@xamarin.com>
+//
+// Copyright (c) 2012 Xamarin Inc. (http://xamarin.com)
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+using System;
+using ICSharpCode.NRefactory.Editor;
+using System.IO;
+using System.Text;
+
+namespace Mono.CSharp
+{
+	public class SeekableStreamReader : IDisposable
+	{
+		public const int DefaultReadAheadSize = 2048;
+
+		readonly ITextSource textSource;
+
+		int pos;
+
+		public SeekableStreamReader (Stream stream, Encoding encoding, char[] sharedBuffer = null)
+		{
+			throw new NotImplementedException ();
+		}
+
+		public SeekableStreamReader (ITextSource source)
+		{
+			this.textSource = source;
+		}
+
+
+		public void Dispose ()
+		{
+		}
+		
+		/// <remarks>
+		///   This value corresponds to the current position in a stream of characters.
+		///   The StreamReader hides its manipulation of the underlying byte stream and all
+		///   character set/decoding issues.  Thus, we cannot use this position to guess at
+		///   the corresponding position in the underlying byte stream even though there is
+		///   a correlation between them.
+		/// </remarks>
+		public int Position {
+			get {
+				return pos;
+			}
+			
+			set {
+				pos = value;
+			}
+		}
+
+		public char GetChar (int position)
+		{
+			return textSource.GetCharAt (position);
+		}
+		
+		public char[] ReadChars (int fromPosition, int toPosition)
+		{
+			return textSource.GetText (fromPosition, toPosition - fromPosition).ToCharArray ();
+		}
+		
+		public int Peek ()
+		{
+			if (pos >= textSource.TextLength)
+				return -1;
+			return textSource.GetCharAt (pos);
+		}
+		
+		public int Read ()
+		{
+			if (pos >= textSource.TextLength)
+				return -1;
+			return textSource.GetCharAt (pos++);
+		}
+	}
+}
+

ICSharpCode.NRefactory.CSharp/Parser/mcs/support.cs

@@ -127,7 +127,7 @@ namespace Mono.CSharp {
 			return true;
 		}
 	}
-
+	#if !FULL_AST
 	/// <summary>
 	///   This is an arbitrarily seekable StreamReader wrapper.
 	///
@@ -276,7 +276,7 @@ namespace Mono.CSharp {
 			return buffer [pos++];
 		}
 	}
-
+#endif
 	public class UnixUtils {
 		[System.Runtime.InteropServices.DllImport ("libc", EntryPoint="isatty")]
 		extern static int _isatty (int fd);