Source code for google.appengine.ext.builtins
#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
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"""Repository for all builtin handlers information.
On initialization, this file generates a list of builtin handlers that have
associated app.yaml information. This file can then be called to read that
information and make it available.
"""
import logging
import os
DEFAULT_DIR = os.path.join(os.path.dirname(__file__))
_handler_dir = None
_available_builtins = None
BUILTINS_NOT_AVAIABLE_IN_PYTHON27 = set(['datastore_admin', 'mapreduce'])
INCLUDE_FILENAME_TEMPLATE = 'include-%s.yaml'
DEFAULT_INCLUDE_FILENAME = 'include.yaml'
[docs]class InvalidBuiltinName(Exception):
"""Raised whenever a builtin handler name is specified that is not found."""
[docs]def reset_builtins_dir():
"""Public method for resetting builtins directory to default."""
set_builtins_dir(DEFAULT_DIR)
[docs]def set_builtins_dir(path):
"""Sets the appropriate path for testing and reinitializes the module."""
global _handler_dir, _available_builtins
_handler_dir = path
_available_builtins = []
_initialize_builtins()
def _initialize_builtins():
"""Scan the immediate subdirectories of the builtins module.
Encountered subdirectories with an app.yaml file are added to
AVAILABLE_BUILTINS.
"""
if os.path.isdir(_handler_dir):
for filename in os.listdir(_handler_dir):
if os.path.isfile(_get_yaml_path(filename, '')):
_available_builtins.append(filename)
def _get_yaml_path(builtin_name, runtime):
"""Return expected path to a builtin handler's yaml file without error check.
"""
runtime_specific = os.path.join(_handler_dir, builtin_name,
INCLUDE_FILENAME_TEMPLATE % runtime)
if runtime and os.path.exists(runtime_specific):
return runtime_specific
return os.path.join(_handler_dir, builtin_name, DEFAULT_INCLUDE_FILENAME)
[docs]def get_yaml_path(builtin_name, runtime=''):
"""Returns the full path to a yaml file by giving the builtin module's name.
Args:
builtin_name: single word name of builtin handler
runtime: name of the runtime
Raises:
ValueError: if handler does not exist in expected directory
Returns:
the absolute path to a valid builtin handler include.yaml file
"""
if _handler_dir is None:
set_builtins_dir(DEFAULT_DIR)
available_builtins = set(_available_builtins)
if runtime == 'python27':
available_builtins = available_builtins - BUILTINS_NOT_AVAIABLE_IN_PYTHON27
if builtin_name not in available_builtins:
raise InvalidBuiltinName(
'%s is not the name of a valid builtin.\n'
'Available handlers are: %s' % (
builtin_name, ', '.join(sorted(available_builtins))))
return _get_yaml_path(builtin_name, runtime)
[docs]def get_yaml_basepath():
"""Returns the full path of the directory in which builtins are located."""
if _handler_dir is None:
set_builtins_dir(DEFAULT_DIR)
return _handler_dir