Remember and reuse derived map for external arrays

src/mirror-debugger.js

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 152 matching lines @@
 const kMaxProtocolStringLength = 80;
 
 // Different kind of properties.
 PropertyKind = {};
 PropertyKind.Named   = 1;
 PropertyKind.Indexed = 2;
 
 
 // A copy of the PropertyType enum from global.h
 PropertyType = {};
-PropertyType.Normal             = 0;
-PropertyType.Field              = 1;
-PropertyType.ConstantFunction   = 2;
-PropertyType.Callbacks          = 3;
-PropertyType.Interceptor        = 4;
-PropertyType.MapTransition      = 5;
-PropertyType.ConstantTransition = 6;
-PropertyType.NullDescriptor     = 7;
+PropertyType.Normal                  = 0;
+PropertyType.Field                   = 1;
+PropertyType.ConstantFunction        = 2;
+PropertyType.Callbacks               = 3;
+PropertyType.Interceptor             = 4;
+PropertyType.MapTransition           = 5;
+PropertyType.ExternalArrayTransition = 6;
+PropertyType.ConstantTransition      = 7;
+PropertyType.NullDescriptor          = 8;
 
 
 // Different attributes for a property.
 PropertyAttribute = {};
 PropertyAttribute.None       = NONE;
 PropertyAttribute.ReadOnly   = READ_ONLY;
 PropertyAttribute.DontEnum   = DONT_ENUM;
 PropertyAttribute.DontDelete = DONT_DELETE;
 
 
@@ skipping 2180 matching lines @@
   }
   if (!NUMBER_IS_FINITE(value)) {
     if (value > 0) {
       return 'Infinity';
     } else {
       return '-Infinity';
     }
   }
   return value;
 }