rebaseline_server: extend returned JSON dict to allow for result-editing in coming CL

gm/rebaseline_server/server.py

 #!/usr/bin/python
 
 '''
 Copyright 2013 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 '''
 
 '''
@@ skipping 61 matching lines @@
   """
   def __init__(self,
                actuals_dir=DEFAULT_ACTUALS_DIR,
                expectations_dir=DEFAULT_EXPECTATIONS_DIR,
                port=DEFAULT_PORT, export=False):
     self._actuals_dir = actuals_dir
     self._expectations_dir = expectations_dir
     self._port = port
     self._export = export
 
+  def is_exported(self):
+    """ Returns true iff HTTP clients on other hosts are allowed to access
+    this server. """
+    return self._export
+
   def fetch_results(self):
     """ Create self.results, based on the expectations in
     self._expectations_dir and the latest actuals from skia-autogen.
 
     TODO(epoger): Add a new --browseonly mode setting.  In that mode,
     the gm-actuals and expectations will automatically be updated every few
     minutes.  See discussion in https://codereview.chromium.org/24274003/ .
     """
     print 'Checking out latest actual GM results from %s into %s ...' % (
         ACTUALS_SVN_REPO, self._actuals_dir)
@@ skipping 51 matching lines @@
     dispatcher(remainder)
 
   def do_GET_results(self, result_type):
     """ Handle a GET request for GM results.
     For now, we ignore the remaining path info, because we only know how to
     return all results.
 
     TODO(epoger): Unless we start making use of result_type, remove that
     parameter."""
     print 'do_GET_results: sending results of type "%s"' % result_type
+    # TODO(epoger): Cache response_dict rather than the results object, to save
+    # time on subsequent fetches (no need to regenerate the header, etc.)
     response_dict = _SERVER.results.GetAll()
     if response_dict:
+      response_dict["header"] = {
+        # Hash of testData, which the client must return with any edits--
+        # this ensures that the edits were made to a particular dataset.
+        "data-hash": str(hash(repr(response_dict["testData"]))),
+
+        # Whether the server will accept edits back.
+        # TODO(epoger): Not yet implemented, so hardcoding to False;
+        # once we implement the "browseonly" mode discussed in
+        # https://codereview.chromium.org/24274003/#msg6 , this value will vary.
+        "is-editable": False,
+
+        # Whether the service is accessible from other hosts.
+        "is-exported": _SERVER.is_exported(),
+      }
       self.send_json_dict(response_dict)
     else:
       self.send_error(404)
 
   def do_GET_static(self, path):
     """ Handle a GET request for a file under the 'static' directory.
     Only allow serving of files within the 'static' directory that is a
     filesystem sibling of this script. """
     print 'do_GET_static: sending file "%s"' % path
     static_dir = os.path.realpath(os.path.join(PARENT_DIRECTORY, 'static'))
@@ skipping 63 matching lines @@
                             'defaults to %(default)s'),
                       default=DEFAULT_PORT)
   args = parser.parse_args()
   global _SERVER
   _SERVER = Server(expectations_dir=args.expectations_dir,
                    port=args.port, export=args.export)
   _SERVER.run()
 
 if __name__ == '__main__':
   main()