Only create one code reader

4 files changed, 23 insertions, 10 deletions

diff --git a/Mono.Cecil.Cil/CodeReader.cs b/Mono.Cecil.Cil/CodeReader.cs
index f102d68..b65e98a 100644
--- a/Mono.Cecil.Cil/CodeReader.cs
+++ b/Mono.Cecil.Cil/CodeReader.cs
@@ -30,23 +30,29 @@ namespace Mono.Cecil.Cil {
 			get { return Position - start; }
 		}
 
-		public CodeReader (MethodDefinition method, MetadataReader reader)
+		public CodeReader (MetadataReader reader)
 			: base (reader.image.Stream)
 		{
 			this.reader = reader;
+		}
+
+		public void MoveTo (MethodDefinition method)
+		{
+			this.method = method;
 			this.reader.context = method;
 			this.Position = (int) reader.image.ResolveVirtualAddress ((uint) method.RVA);
 		}
 
-		public static MethodBody ReadMethodBody (MethodDefinition method, MetadataReader metadata)
+		public MethodBody ReadMethodBody (MethodDefinition method)
 		{
-			var reader = new CodeReader (method, metadata);
-			reader.method = method;
-			reader.body = new MethodBody (method);
+			MoveTo (method);
+			this.body = new MethodBody (method);
 
-			reader.ReadMethodBody ();
+			ReadMethodBody ();
 
-			return reader.body;
+			this.reader.context = null;
+
+			return this.body;
 		}
 
 		void ReadMethodBody ()
@@ -435,6 +441,8 @@ namespace Mono.Cecil.Cil {
 
 		public ByteBuffer PatchRawMethodBody (MethodDefinition method, CodeWriter writer, out int code_size, out MetadataToken local_var_token)
 		{
+			MoveTo (method);
+
 			var buffer = new ByteBuffer ();
 
 			var flags = ReadByte ();
@@ -454,6 +462,8 @@ namespace Mono.Cecil.Cil {
 				throw new NotSupportedException ();
 			}
 
+			reader.context = null;
+
 			return buffer;
 		}
 
diff --git a/Mono.Cecil.Cil/CodeWriter.cs b/Mono.Cecil.Cil/CodeWriter.cs
index 6659a10..58c9277 100644
--- a/Mono.Cecil.Cil/CodeWriter.cs
+++ b/Mono.Cecil.Cil/CodeWriter.cs
@@ -75,7 +75,7 @@ namespace Mono.Cecil.Cil {
 
 		void WriteUnresolvedMethodBody (MethodDefinition method)
 		{
-			var code_reader = metadata.module.Read (method, (m, reader) => new CodeReader (m, reader));
+			var code_reader = metadata.module.Read (method, (_, reader) => reader.code);
 
 			int code_size;
 			MetadataToken local_var_token;
diff --git a/Mono.Cecil/AssemblyReader.cs b/Mono.Cecil/AssemblyReader.cs
index 91d6dae..8211a10 100644
--- a/Mono.Cecil/AssemblyReader.cs
+++ b/Mono.Cecil/AssemblyReader.cs
@@ -443,6 +443,7 @@ namespace Mono.Cecil {
 		readonly internal ModuleDefinition module;
 		readonly internal MetadataSystem metadata;
 
+		internal CodeReader code;
 		internal IGenericContext context;
 
 		readonly MetadataReader metadata_reader;
@@ -458,6 +459,7 @@ namespace Mono.Cecil {
 			this.image = module.Image;
 			this.module = module;
 			this.metadata = module.MetadataSystem;
+			this.code = new CodeReader (this);
 		}
 
 		public MetadataReader (Image image, ModuleDefinition module, MetadataReader metadata_reader)
@@ -2140,7 +2142,7 @@ namespace Mono.Cecil {
 
 		public MethodBody ReadMethodBody (MethodDefinition method)
 		{
-			return CodeReader.ReadMethodBody (method, this);
+			return code.ReadMethodBody (method);
 		}
 
 		public CallSite ReadCallSite (MetadataToken token)
diff --git a/rocks/Mono.Cecil.Rocks/ILParser.cs b/rocks/Mono.Cecil.Rocks/ILParser.cs
index a6b9383..8d119eb 100644
--- a/rocks/Mono.Cecil.Rocks/ILParser.cs
+++ b/rocks/Mono.Cecil.Rocks/ILParser.cs
@@ -79,7 +79,8 @@ namespace Mono.Cecil.Rocks {
 
 		static ParseContext CreateContext (MethodDefinition method, IILVisitor visitor)
 		{
-			var code = method.Module.Read (method, (m, reader) => new CodeReader (method, reader));
+			var code = method.Module.Read (method, (_, reader) => reader.code);
+			code.MoveTo (method);
 
 			return new ParseContext {
 				Code = code,