Load time improvements (fixes #140)

lib/src/codegen/html_codegen.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dev_compiler.src.codegen.html_codegen;
 
 import 'package:html/dom.dart';
 import 'package:html/parser.dart' show parseFragment;
 import 'package:logging/logging.dart' show Logger;
 import 'package:path/path.dart' as path;
@@ skipping 35 matching lines @@
   var resources = [];
   visitInPostOrder(root, (n) {
     if (n is DartSourceNode) libraries.add(n);
     if (n is ResourceSourceNode) resources.add(n);
   }, includeParts: false);
 
   String mainLibraryName;
   var fragment = new DocumentFragment();
   for (var resource in resources) {
     var resourcePath = resourceOutputPath(resource.uri, root.uri);
+    var ext = path.extension(resourcePath);
     if (resource.cachingHash != null) {
       resourcePath = _addHash(resourcePath, resource.cachingHash);
     }
-    var ext = path.extension(resourcePath);
     if (ext == '.css') {
       fragment.nodes.add(_cssInclude(resourcePath));
     } else if (ext == '.js') {
       fragment.nodes.add(_libraryInclude(resourcePath));
     }
   }
   for (var lib in libraries) {
     var info = lib.info;
     if (info == null) continue;
     if (info.isEntry) mainLibraryName = jsLibraryName(info.library);
@@ skipping 21 matching lines @@
   var code = mainLibraryName == null
       ? 'console.error("dev_compiler error: main was not generated");'
       : '$mainLibraryName.main();';
   return parseFragment('<script>$code</script>\n');
 }
 
 /// Convert the outputPath to include the hash in it. This function is the
 /// reverse of what the server does to determine whether a request needs to have
 /// cache headers added to it.
 _addHash(String outPath, String hash) {
-  return path.join('cached', hash, outPath);
+  // (the ____ prefix makes it look better in the web inspector)
+  return '$outPath?____cached=$hash';
 }
 
 final _log = new Logger('dev_compiler.src.codegen.html_codegen');