Expose 'serveFile' on VirtualDirectory.

pkg/http_server/lib/src/virtual_directory.dart

 // Copyright (c) 2013, 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.
 
 part of http_server;
 
 /**
  * A [VirtualDirectory] can serve files and directory-listing from a root path,
  * to [HttpRequest]s.
  *
@@ skipping 46 matching lines @@
    * Serve a single [HttpRequest], in this [VirtualDirectory].
    */
   void serveRequest(HttpRequest request) {
     _locateResource('.', request.uri.pathSegments.iterator..moveNext())
         .then((entity) {
           if (entity == null) {
             _serveErrorPage(HttpStatus.NOT_FOUND, request);
             return;
           }
           if (entity is File) {
-            _serveFile(entity, request);
+            serveFile(entity, request);
           } else if (entity is Directory) {
             _serveDirectory(entity, request);
           } else {
             _serveErrorPage(HttpStatus.NOT_FOUND, request);
           }
         });
   }
 
   /**
    * Set the [callback] to override the default directory listing. The
@@ skipping 56 matching lines @@
                       }
                     });
               }
               break;
           }
           // Return `null` on fall-through, to indicate NOT_FOUND.
           return null;
         });
   }
 
-  void _serveFile(File file, HttpRequest request) {
+  /**
+   * Serve the content of [file] to [request].
+   *
+   * This is usefull when e.g. overriding [directoryHandler] to redirect to
+   * some index file.
+   *
+   * In the request contains the [HttpStatus.IF_MODIFIED_SINCE] header,
+   * [serveFile] will send a [HttpStatus.NOT_MODIFIED] response if the file
+   * was not changed.
+   *
+   * Note that if it was unabled to read from [file], the [request]s response
+   * is closed with error-code [HttpStatus.NOT_FOUND].
+   */
+  void serveFile(File file, HttpRequest request) {
     var response = request.response;
     // TODO(ajohnsen): Set up Zone support for these errors.
     file.lastModified().then((lastModified) {
       if (request.headers.ifModifiedSince != null &&
           !lastModified.isAfter(request.headers.ifModifiedSince)) {
         response.statusCode = HttpStatus.NOT_MODIFIED;
         response.close();
         return;
       }
 
@@ skipping 39 matching lines @@
                 .catchError((_) {});
             return;
           }
         }
 
         file.openRead()
             .pipe(new _VirtualDirectoryFileStream(response, file.path))
             .catchError((_) {});
       });
     }).catchError((_) {
+      response.statusCode = HttpStatus.NOT_FOUND;
       response.close();
     });
   }
 
   void _serveDirectory(Directory dir, HttpRequest request) {
     if (_dirCallback != null) {
       _dirCallback(dir, request);
       return;
     }
     var response = request.response;
@@ skipping 149 matching lines @@
 
   Future close() => new Future.value();
 
   void setMimeType(var bytes) {
     var mimeType = lookupMimeType(path, headerBytes: bytes);
     if (mimeType != null) {
       response.headers.contentType = ContentType.parse(mimeType);
     }
   }
 }