Reworked devserver so that update images generated are cached in directories named after

devserver.py

 #!/usr/bin/python
 
 # Copyright (c) 2009-2010 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """A CherryPy-based webserver to host images and build packages."""
 
 import cherrypy
 import optparse
 import os
 import sys
 
 import autoupdate
 
+CACHED_ENTRIES=12
+
 # Sets up global to share between classes.
 global updater
 updater = None
 
 def _GetConfig(options):
   """Returns the configuration for the devserver."""
   base_config = { 'global':
                   { 'server.log_request_headers': True,
                     'server.protocol_version': 'HTTP/1.1',
                     'server.socket_host': '0.0.0.0',
@@ skipping 80 matching lines @@
   index.exposed = True
 
 
 if __name__ == '__main__':
   usage = 'usage: %prog [options]'
   parser = optparse.OptionParser(usage)
   parser.add_option('--archive_dir', dest='archive_dir',
                     help='serve archived builds only.')
   parser.add_option('--board', dest='board',
                     help='When pre-generating update, board for latest image.')
+  parser.add_option('--clear_cache', action="store_true", default=False,
+                    help='Clear out all cached udpates and exit')
   parser.add_option('--client_prefix', dest='client_prefix',
                     help='Required prefix for client software version.',
                     default='MementoSoftwareUpdate')
   parser.add_option('--factory_config', dest='factory_config',
                     help='Config file for serving images from factory floor.')
   parser.add_option('--for_vm', dest='vm', default=False, action='store_true',
                     help='Update is for a vm image.')
   parser.add_option('--image', dest='image',
                     help='Force update using this image.')
   parser.add_option('-p', '--pregenerate_update', action='store_true',
                     default=False, help='Pre-generate update payload.')
   parser.add_option('--port', default=8080,
                     help='Port for the dev server to use.')
   parser.add_option('--src_image', default='',
                     help='Image on remote machine for generating delta update.')
   parser.add_option('-t', action='store_true', dest='test_image')
   parser.add_option('-u', '--urlbase', dest='urlbase',
                     help='base URL, other than devserver, for update images.')
-  parser.add_option('--use_cached', action="store_true", default=False,
-                    help='Prefer cached image regardless of timestamps.')
   parser.add_option('--validate_factory_config', action="store_true",
                     dest='validate_factory_config',
                     help='Validate factory config file, then exit.')
   parser.set_usage(parser.format_help())
   (options, _) = parser.parse_args()
 
   devserver_dir = os.path.dirname(os.path.abspath(sys.argv[0]))
   root_dir = os.path.realpath('%s/../..' % devserver_dir)
   serve_only = False
 
   if options.archive_dir:
     static_dir = os.path.realpath(options.archive_dir)
     _PrepareToServeUpdatesOnly(static_dir)
     serve_only = True
   else:
     static_dir = os.path.realpath('%s/static' % devserver_dir)
     os.system('mkdir -p %s' % static_dir)
 
+  cache_dir = os.path.join(static_dir, 'cache')
+  cherrypy.log('Using cache directory %s' % cache_dir, 'DEVSERVER')
+
+  if options.clear_cache:
+    # Clear the cache and exit
+    sys.exit(os.system('sudo rm -rf %s' % cache_dir))
+
+  if os.path.exists(cache_dir):
+    # Clear all but the last N cached updates
+    cmd = ('cd %s; ls -1tr | head --lines=-%d | xargs rm -rf' %
+           (cache_dir, CACHED_ENTRIES))
+    if os.system(cmd) != 0:
+      cherrypy.log('Failed to clean up old delta cache files with %s' % cmd,
+                   'DEVSERVER')
+      sys.exit(1)
+
   cherrypy.log('Source root is %s' % root_dir, 'DEVSERVER')
   cherrypy.log('Serving from %s' % static_dir, 'DEVSERVER')
 
   updater = autoupdate.Autoupdate(
       root_dir=root_dir,
       static_dir=static_dir,
       serve_only=serve_only,
       urlbase=options.urlbase,
       test_image=options.test_image,
       factory_config_path=options.factory_config,
       client_prefix=options.client_prefix,
       forced_image=options.image,
-      use_cached=options.use_cached,
       port=options.port,
       src_image=options.src_image,
       vm=options.vm,
       board=options.board)
 
   # Sanity-check for use of validate_factory_config.
   if not options.factory_config and options.validate_factory_config:
     parser.error('You need a factory_config to validate.')
 
   if options.factory_config:
     updater.ImportFactoryConfigFile(options.factory_config,
                                      options.validate_factory_config)
     # We don't run the dev server with this option.
     if options.validate_factory_config:
       sys.exit(0)
   elif options.pregenerate_update:
     if not updater.PreGenerateUpdate():
       sys.exit(1)
 
   cherrypy.quickstart(DevServerRoot(), config=_GetConfig(options))