Use ByteArray's native for Socket and File.

runtime/lib/byte_array.dart

Index: runtime/lib/byte_array.dart
===================================================================
--- runtime/lib/byte_array.dart	(revision 3621)
+++ runtime/lib/byte_array.dart	(working copy)
@@ -63,6 +63,40 @@
     return _length();
   }
 
+  void setRange(int start, int length, List<int> from, [int startFrom = 0]) {
+    if (length < 0) {
+      throw new IllegalArgumentException("negative length $length");
+    }
+    if (from is ByteArray) {
+      copy(this, start, from, startFrom, length);
+    } else {
+      Arrays.copy(from, startFrom, this, start, length);
+    }
+  }
+
+  
+  List getRange(int start, int length) {
+    if (length == 0) return [];
+    Arrays.rangeCheck(this, start, length);
+    ByteArray list = new ByteArray(length);
+    copy(list, 0, this, start, length);
+    return list;
+  }
+
+  static copy(ByteArray dst, 

[Anders Johnsen, 2012/01/26 19:38:13]

I'm not entirely happy with the placement of this and the name of the native
method. Any comments are welcome!

[cshapiro, 2012/01/27 23:00:04]

I would create a private instance method _setRange which calls a native
ByteArray_setRange.  The term copy seems ambiguous in this context, especially
because it does not return a copy but rather copies into something.

[Anders Johnsen, 2012/01/27 23:42:39]

Thank you, way better! :)

+              int dstStart, 
+              ByteArray src, 
+              int srcStart, 
+              int length) {
+    dst._copyFromByteArray(src, srcStart, dstStart, length);
+  }
+
+  void _copyFromByteArray(ByteArray src,
+                          int srcStart,
+                          int dstStart,
+                          int count)
+      native "ByteArray_copyFromByteArray";
+
   bool every(bool f(int element)) {
     return Collections.every(this, f);
   }