Made testserver communicate to parent process with JSON

net/tools/testserver/testserver.py

 #!/usr/bin/python2.4
 # Copyright (c) 2006-2010 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """This is a simple HTTP server used for testing Chrome.
 
 It supports several test URLs, as specified by the handlers in TestPageHandler.
 By default, it listens on an ephemeral port and sends the port number back to
 the originating process over a pipe. The originating process can specify an
 explicit port if necessary.
 It can use https if you specify the flag --https=CERT where CERT is the path
 to a pem file containing the certificate and private key that should be used.
 """
 
 import base64
 import BaseHTTPServer
 import cgi
 import optparse
 import os
 import re
 import shutil
 import SocketServer
 import sys
 import struct
 import time
 import urlparse
 import warnings
 
+# If we use simplejson always, we get some warnings when we run under
+# 2.6.
+if sys.version_info < (2, 6):
+  import simplejson as json
+else:
+  import json
+
 # Ignore deprecation warnings, they make our output more cluttered.
 warnings.filterwarnings("ignore", category=DeprecationWarning)
 
 import pyftpdlib.ftpserver
 import tlslite
 import tlslite.api
 
 try:
   import hashlib
   _new_md5 = hashlib.md5
@@ skipping 1274 matching lines @@
 
     # Instantiate FTP server class and listen to 127.0.0.1:port
     address = ('127.0.0.1', port)
     server = pyftpdlib.ftpserver.FTPServer(address, ftp_handler)
     listen_port = server.socket.getsockname()[1]
     print 'FTP server started on port %d...' % listen_port
 
   # Notify the parent that we've started. (BaseServer subclasses
   # bind their sockets on construction.)
   if options.startup_pipe is not None:
+    server_data = {
+      'port': listen_port
+    }
+    server_data_json = json.dumps(server_data)
+    debug('sending server_data: %s' % server_data_json)
+    server_data_len = len(server_data_json)
     if sys.platform == 'win32':
       fd = msvcrt.open_osfhandle(options.startup_pipe, 0)
     else:
       fd = options.startup_pipe
     startup_pipe = os.fdopen(fd, "w")
-    # Write the listening port as a 2 byte value. This is _not_ using
-    # network byte ordering since the other end of the pipe is on the same
-    # machine.
-    startup_pipe.write(struct.pack('@H', listen_port))
+    # First write the data length as an unsigned 4-byte value.  This
+    # is _not_ using network byte ordering since the other end of the
+    # pipe is on the same machine.
+    startup_pipe.write(struct.pack('=L', server_data_len))
+    startup_pipe.write(server_data_json)
     startup_pipe.close()
 
   try:
     server.serve_forever()
   except KeyboardInterrupt:
     print 'shutting down server'
     server.stop = True
 
 if __name__ == '__main__':
   option_parser = optparse.OptionParser()
@@ skipping 31 matching lines @@
                            'option may appear multiple times, indicating '
                            'multiple algorithms should be enabled.');
   option_parser.add_option('', '--file-root-url', default='/files/',
                            help='Specify a root URL for files served.')
   option_parser.add_option('', '--startup-pipe', type='int',
                            dest='startup_pipe',
                            help='File handle of pipe to parent process')
   options, args = option_parser.parse_args()
 
   sys.exit(main(options, args))