Docserver: refactor the Handler/ServerInstance relationship into a servlet

chrome/common/extensions/docs/server2/preview.py

 #!/usr/bin/env python
 # Copyright (c) 2012 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 helps you preview the apps and extensions docs.
 #
 #    ./preview.py --help
 #
 # There are two modes: server- and render- mode. The default is server, in which
@@ skipping 15 matching lines @@
 #
 # Note: absolute paths into static content (e.g. /static/css/site.css) will be
 # relative paths (e.g. static/css/site.css) for convenient sandboxing.
 
 # NOTE: RUN THIS FIRST. Or all third_party imports will fail.
 import build_server
 # Copy all the files necessary to run the server. These are cleaned up when the
 # server quits.
 build_server.main()
 
+from render_servlet import AlwaysOnline
 from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
 from local_renderer import LocalRenderer
 import logging
 import optparse
 import os
 import sys
 import time
 
 def _GetLocalPath():
   if os.sep in sys.argv[0]:
     return os.path.join(sys.argv[0].rsplit(os.sep, 1)[0], os.pardir, os.pardir)
   return os.path.join(os.pardir, os.pardir)
 
+@AlwaysOnline
 def _Render(base_dir, path):
   renderer = LocalRenderer(base_dir)
-  content, status, headers = renderer.Render(path, always_online=True)
-  while status in [301, 302]:
-    redirect = headers['Location'].lstrip('/')
+  response = renderer.Render(path)
+  while response.status in [301, 302]:
+    redirect = response.headers['Location'].lstrip('/')
     sys.stderr.write('<!-- Redirected %s to %s -->\n' % (path, redirect))
-    content, status, headers = renderer.Render(redirect, always_online=True)
-  return (content, status, headers)
+    response = renderer.Render(redirect)
+  return response
 
 class RequestHandler(BaseHTTPRequestHandler):
   class Factory(object):
     def __init__(self, base_dir):
       self._base_dir = base_dir
 
     def Create(self, *args):
       return RequestHandler(self._base_dir, *args)
 
   def __init__(self, base_dir, *args):
     self._base_dir = base_dir
     BaseHTTPRequestHandler.__init__(self, *args)
 
   """A HTTPRequestHandler that outputs the docs page generated by Handler.
   """
   def do_GET(self):
-    content, status, headers = _Render(self._base_dir, self.path)
-    self.send_response(status)
-    for k, v in headers.iteritems():
+    response = _Render(self._base_dir, self.path)
+    self.send_response(response.status)
+    for k, v in response.headers.iteritems():
       self.send_header(k, v)
     self.end_headers()
-    self.wfile.write(content)
+    self.wfile.write(response.content)
 
 if __name__ == '__main__':
   parser = optparse.OptionParser(
       description='Runs a server to preview the extension documentation.',
       usage='usage: %prog [option]...')
   parser.add_option('-p', '--port', default='8000',
       help='port to run the server on')
   parser.add_option('-d', '--directory', default=_GetLocalPath(),
       help='extensions directory to serve from - '
            'should be chrome/common/extensions within a Chromium checkout')
@@ skipping 18 matching lines @@
     if opts.render.find('#') >= 0:
       (path, iterations) = opts.render.rsplit('#', 1)
       extra_iterations = int(iterations) - 1
     else:
       path = opts.render
       extra_iterations = 0
 
     if opts.time:
       start_time = time.time()
 
-    content, status, headers = _Render(opts.directory, path)
-    if status != 200:
-      print('Error status: %s' % status)
+    response = _Render(opts.directory, path)
+    if response.status != 200:
+      print('Error status: %s' % response.status)
       exit(1)
 
     for _ in range(extra_iterations):
       _Render(opts.directory, path)
 
     if opts.time:
       print('Took %s seconds' % (time.time() - start_time))
     else:
       # Static paths will show up as /stable/static/foo but this only makes
       # sense from a webserver.
@@ skipping 11 matching lines @@
   print('  http://localhost:%s/apps/' % opts.port)
   print('')
 
   logging.getLogger().setLevel(logging.INFO)
   server = HTTPServer(('', int(opts.port)),
                       RequestHandler.Factory(opts.directory).Create)
   try:
     server.serve_forever()
   finally:
     server.socket.close()