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-rw-r--r--ipalib/plugable.py251
1 files changed, 2 insertions, 249 deletions
diff --git a/ipalib/plugable.py b/ipalib/plugable.py
index 0120f9729..923b72ad6 100644
--- a/ipalib/plugable.py
+++ b/ipalib/plugable.py
@@ -36,104 +36,9 @@ import subprocess
import errors
from errors import check_type, check_isinstance
from config import Env
-from constants import DEFAULT_CONFIG
import util
-
-
-
-class ReadOnly(object):
- """
- Base class for classes with read-only attributes.
-
- Be forewarned that Python does not offer true read-only user defined
- classes. In particular, do not rely upon the read-only-ness of this
- class for security purposes.
-
- The point of this class is not to make it impossible to set or delete
- attributes, but to make it impossible to accidentally do so. The plugins
- are not thread-safe: in the server, they are loaded once and the same
- instances will be used to process many requests. Therefore, it is
- imperative that they not set any instance attributes after they have
- been initialized. This base class enforces that policy.
-
- For example:
-
- >>> ro = ReadOnly() # Initially unlocked, can setattr, delattr
- >>> ro.name = 'John Doe'
- >>> ro.message = 'Hello, world!'
- >>> del ro.message
- >>> ro.__lock__() # Now locked, cannot setattr, delattr
- >>> ro.message = 'How are you?'
- Traceback (most recent call last):
- File "<stdin>", line 1, in <module>
- File ".../ipalib/plugable.py", line 93, in __setattr__
- (self.__class__.__name__, name)
- AttributeError: read-only: cannot set ReadOnly.message
- >>> del ro.name
- Traceback (most recent call last):
- File "<stdin>", line 1, in <module>
- File "/home/jderose/projects/freeipa2/ipalib/plugable.py", line 104, in __delattr__
- (self.__class__.__name__, name)
- AttributeError: read-only: cannot del ReadOnly.name
- """
-
- __locked = False
-
- def __lock__(self):
- """
- Put this instance into a read-only state.
-
- After the instance has been locked, attempting to set or delete an
- attribute will raise AttributeError.
- """
- assert self.__locked is False, '__lock__() can only be called once'
- self.__locked = True
-
- def __islocked__(self):
- """
- Return True if instance is locked, otherwise False.
- """
- return self.__locked
-
- def __setattr__(self, name, value):
- """
- If unlocked, set attribute named ``name`` to ``value``.
-
- If this instance is locked, AttributeError will be raised.
- """
- if self.__locked:
- raise AttributeError('read-only: cannot set %s.%s' %
- (self.__class__.__name__, name)
- )
- return object.__setattr__(self, name, value)
-
- def __delattr__(self, name):
- """
- If unlocked, delete attribute named ``name``.
-
- If this instance is locked, AttributeError will be raised.
- """
- if self.__locked:
- raise AttributeError('read-only: cannot del %s.%s' %
- (self.__class__.__name__, name)
- )
- return object.__delattr__(self, name)
-
-
-def lock(readonly):
- """
- Lock a `ReadOnly` instance.
-
- This is mostly a convenience function to call `ReadOnly.__lock__()`. It
- also verifies that the locking worked using `ReadOnly.__islocked__()`
-
- :param readonly: An instance of the `ReadOnly` class.
- """
- if not isinstance(readonly, ReadOnly):
- raise ValueError('not a ReadOnly instance: %r' % readonly)
- readonly.__lock__()
- assert readonly.__islocked__(), 'Ouch! The locking failed?'
- return readonly
+from base import ReadOnly, NameSpace, lock, islocked, check_name
+from constants import DEFAULT_CONFIG
class SetProxy(ReadOnly):
@@ -512,158 +417,6 @@ class PluginProxy(SetProxy):
)
-def check_name(name):
- """
- Verify that ``name`` is suitable for a `NameSpace` member name.
-
- Raises `errors.NameSpaceError` if ``name`` is not a valid Python
- identifier suitable for use as the name of `NameSpace` member.
-
- :param name: Identifier to test.
- """
- check_type(name, str, 'name')
- regex = r'^[a-z][_a-z0-9]*[a-z0-9]$'
- if re.match(regex, name) is None:
- raise errors.NameSpaceError(name, regex)
- return name
-
-
-class NameSpace(ReadOnly):
- """
- A read-only namespace with handy container behaviours.
-
- Each member of a NameSpace instance must have a ``name`` attribute whose
- value:
-
- 1. Is unique among the members
- 2. Passes the `check_name()` function
-
- Beyond that, no restrictions are placed on the members: they can be
- classes or instances, and of any type.
-
- The members can be accessed as attributes on the NameSpace instance or
- through a dictionary interface. For example:
-
- >>> class obj(object):
- ... name = 'my_obj'
- ...
- >>> namespace = NameSpace([obj])
- >>> obj is getattr(namespace, 'my_obj') # As attribute
- True
- >>> obj is namespace['my_obj'] # As dictionary item
- True
-
- Here is a more detailed example:
-
- >>> class Member(object):
- ... def __init__(self, i):
- ... self.i = i
- ... self.name = 'member_%d' % i
- ... def __repr__(self):
- ... return 'Member(%d)' % self.i
- ...
- >>> namespace = NameSpace(Member(i) for i in xrange(3))
- >>> namespace.member_0 is namespace['member_0']
- True
- >>> len(namespace) # Returns the number of members in namespace
- 3
- >>> list(namespace) # As iterable, iterates through the member names
- ['member_0', 'member_1', 'member_2']
- >>> list(namespace()) # Calling a NameSpace iterates through the members
- [Member(0), Member(1), Member(2)]
- >>> 'member_1' in namespace # Does namespace contain 'member_1'?
- True
- """
-
- def __init__(self, members, sort=True):
- """
- :param members: An iterable providing the members.
- :param sort: Whether to sort the members by member name.
- """
- self.__sort = check_type(sort, bool, 'sort')
- if self.__sort:
- self.__members = tuple(sorted(members, key=lambda m: m.name))
- else:
- self.__members = tuple(members)
- self.__names = tuple(m.name for m in self.__members)
- self.__map = dict()
- for member in self.__members:
- name = check_name(member.name)
- assert name not in self.__map, 'already has key %r' % name
- self.__map[name] = member
- assert not hasattr(self, name), 'already has attribute %r' % name
- setattr(self, name, member)
- lock(self)
-
- def __len__(self):
- """
- Return the number of members.
- """
- return len(self.__members)
-
- def __iter__(self):
- """
- Iterate through the member names.
-
- If this instance was created with ``sort=True``, the names will be in
- alphabetical order; otherwise the names will be in the same order as
- the members were passed to the constructor.
-
- This method is like an ordered version of dict.iterkeys().
- """
- for name in self.__names:
- yield name
-
- def __call__(self):
- """
- Iterate through the members.
-
- If this instance was created with ``sort=True``, the members will be
- in alphabetical order by name; otherwise the members will be in the
- same order as they were passed to the constructor.
-
- This method is like an ordered version of dict.itervalues().
- """
- for member in self.__members:
- yield member
-
- def __contains__(self, name):
- """
- Return True if namespace has a member named ``name``.
- """
- return name in self.__map
-
- def __getitem__(self, spec):
- """
- Return a member by name or index, or returns a slice of members.
-
- :param spec: The name or index of a member, or a slice object.
- """
- if type(spec) is str:
- return self.__map[spec]
- if type(spec) in (int, slice):
- return self.__members[spec]
- raise TypeError(
- 'spec: must be %r, %r, or %r; got %r' % (str, int, slice, spec)
- )
-
- def __repr__(self):
- """
- Return a pseudo-valid expression that could create this instance.
- """
- return '%s(<%d members>, sort=%r)' % (
- self.__class__.__name__,
- len(self),
- self.__sort,
- )
-
- def __todict__(self):
- """
- Return a copy of the private dict mapping name to member.
- """
- return dict(self.__map)
-
-
class Registrar(DictProxy):
"""
Collects plugin classes as they are registered.