[WIP] Update index format

Author: grendello

src/Xamarin.Android.Build.Tasks/Utilities/TypeMapGenerator.cs

@@ -214,11 +214,30 @@ public bool Generate (DirectoryAssemblyResolver resolver, IEnumerable<string> as
 			return true;
 		}
 
+		// Binary index file format, all data is little-endian:
+		//
+		//  [Magic string]             # XATI
+		//  [Format version]           # 32-bit integer, 4 bytes
+		//  [Entry count]              # 32-bit integer, 4 bytes
+		//  [Module file name width]   # 32-bit integer, 4 bytes
+		//  [Index entries]            # Format described below, [Entry count] entries
+		//
+		// Index entry format:
+		//
+		//  [Module UUID][File name]<NUL>
+		//
+		// Where:
+		//
+		//   [Module UUID] is 16 bytes long
+		//   [File name] is right-padded with <NUL> characters to the [Module file name width] boundary.
+		//
 		void OutputModules (string outputDirectory, IDictionary<byte[], ModuleData> modules, BinaryWriter indexWriter, int moduleFileNameWidth)
 		{
 			var moduleCounter = new Dictionary <AssemblyDefinition, int> ();
 
 			indexWriter.Write (typemapIndexMagicString);
+			indexWriter.Write (TypeMapFormatVersion);
+			indexWriter.Write (modules.Count);
 			indexWriter.Write (moduleFileNameWidth);
 
 			foreach (var kvp in modules) {

src/monodroid/jni/xamarin-app.hh

@@ -22,6 +22,14 @@ struct BinaryTypeMapHeader
 	uint8_t  assembly_name[];
 };
 
+struct TypeMapIndexHeader
+{
+	uint32_t magic;
+	uint32_t version;
+	uint32_t entry_count;
+	uint32_t module_file_name_width;
+};
+
 struct TypeMapModuleEntry
 {
 	int32_t        type_token_id;