scripts/interactive.py

   1 #!/usr/bin/python2.5
   2 #
   3 # Copyright 2009 the Melange authors.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #   http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 """This module supplies an interactive shell with remote api configured.
  18
  19 Usage is simple:
  20
  21 App Engine interactive console
  22 >>> from soc.models.user import User
  23 >>> gen = lambda: User.all()
  24 >>> it = deepFetch(gen)
  25 >>> result = [i for i in it]
  26 """
  27
  28 __authors__ = [
  29   '"Sverre Rabbelier" <sverre@rabbelier.nl>',
  30 ]
  31
  32
  33
  34 import code
  35 import getpass
  36 import os
  37 import sys
  38
  39
  40 def auth_func():
  41   """Returns a tuple with username and password.
  42   """
  43
  44   return raw_input('Username:'), getpass.getpass('Password:')
  45
  46
  47 def deepFetch(queryGen,key=None,batchSize = 100):
  48   """Iterator that yields an entity in batches.
  49
  50   Args:
  51     queryGen: should return a Query object
  52     key: used to .filter() for __key__
  53     batchSize: how many entities to retrieve in one datastore call
  54
  55   Retrieved from http://tinyurl.com/d887ll (AppEngine cookbook).
  56   """
  57
  58   from google.appengine.ext import db
  59
  60    # AppEngine will not fetch more than 1000 results
  61   batchSize = min(batchSize,1000)
  62
  63   query = None
  64   done = False
  65   count = 0
  66
  67   if key:
  68     key = db.Key(key)
  69
  70   while not done:
  71     print count
  72     query = queryGen()
  73     if key:
  74       query.filter("__key__ > ",key)
  75     results = query.fetch(batchSize)
  76     for result in results:
  77       count += 1
  78       yield result
  79     if batchSize > len(results):
  80       done = True
  81     else:
  82       key = results[-1].key()
  83
  84
  85 def remote(args, context=None):
  86   """Starts a shell with the datastore as remote_api_stub.
  87
  88   Args:
  89     args: arguments from the user
  90     context: locals that should be added to the shell
  91   """
  92
  93   from google.appengine.ext import db
  94   from google.appengine.ext.remote_api import remote_api_stub
  95
  96   if not context:
  97     context = {}
  98
  99   app_id = args[0]
 100
 101   if len(args) > 1:
 102     host = args[1]
 103   else:
 104     host = '%s.appspot.com' % app_id
 105
 106   remote_api_stub.ConfigureRemoteDatastore(app_id, '/remote_api', auth_func, host)
 107
 108   context['deepFetch'] = deepFetch
 109
 110   code.interact('App Engine interactive console for %s' % (app_id,), None, context)
 111
 112
 113 def setup():
 114   """Sets up the sys.path and environment for development.
 115   """
 116
 117   here = os.path.abspath(__file__)
 118   here = os.path.join(os.path.dirname(here), '..')
 119   here = os.path.normpath(here)
 120
 121   appengine_location = os.path.join(here, 'thirdparty', 'google_appengine')
 122
 123   extra_paths = [here,
 124                  os.path.join(appengine_location, 'lib', 'django'),
 125                  os.path.join(appengine_location, 'lib', 'webob'),
 126                  os.path.join(appengine_location, 'lib', 'yaml', 'lib'),
 127                  appengine_location,
 128                  os.path.join(here, 'app'),
 129                 ]
 130
 131   sys.path = extra_paths + sys.path
 132
 133   os.environ['SERVER_SOFTWARE'] = 'Development Interactive Shell'
 134
 135   import main as app_main
 136
 137 def main(args):
 138   """Convenience wrapper that calls setup and remote.
 139   """
 140
 141   setup()
 142   remote(args)
 143
 144
 145 if __name__ == '__main__':
 146   if len(sys.argv) < 2:
 147     print "Usage: %s app_id [host]" % (sys.argv[0],)
 148     sys.exit(1)
 149
 150   main(sys.argv[1:])