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
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.

"""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'])


[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