completely rewrite file based property handling

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
This commit is contained in:
Steven Armstrong 2011-10-14 01:15:08 +02:00
parent be02dc5ff1
commit ede35ffd73

View file

@ -98,55 +98,6 @@ class FileList(collections.MutableSequence):
self.__write(lines) self.__write(lines)
class FileListProperty(FileList):
def __init__(self, path):
"""
:param path: string or callable
Usage:
class Foo(object):
parameters = DirectoryDictProperty(lambda obj: os.path.join(obj.absolute_path, 'parameter'))
other_dict = DirectoryDictProperty('/tmp/folder')
def __init__(self):
self.absolute_path = '/tmp/foo'
"""
self.path = None
self.__path = path
def _set_path(self, *args, **kwargs):
if self.path is None:
path = self.__path
if callable(path):
path = path(*args, **kwargs)
if not os.path.isabs(path):
raise AbsolutePathRequiredError(path)
self.path = path
# Descriptor Protocol
def __get__(self, obj, objtype=None):
if obj is None:
return self.__class__
self._set_path(obj)
return self
def __set__(self, obj, value):
self._set_path(obj)
try:
os.unlink(self.path)
except EnvironmentError:
# ignored
pass
for item in value:
self.append(item)
def __delete__(self, obj):
raise AttributeError("can't delete attribute")
class DirectoryDict(collections.MutableMapping): class DirectoryDict(collections.MutableMapping):
"""A dict that stores it's items as files in a directory. """A dict that stores it's items as files in a directory.
@ -178,7 +129,10 @@ class DirectoryDict(collections.MutableMapping):
fd.write(str(value)) fd.write(str(value))
def __delitem__(self, key): def __delitem__(self, key):
os.remove(os.path.join(self.path, key)) try:
os.remove(os.path.join(self.path, key))
except EnvironmentError:
raise KeyError(key)
def __iter__(self): def __iter__(self):
return iter(os.listdir(self.path)) return iter(os.listdir(self.path))
@ -187,95 +141,98 @@ class DirectoryDict(collections.MutableMapping):
return len(os.listdir(self.path)) return len(os.listdir(self.path))
class DirectoryDictProperty(DirectoryDict): class FileBasedProperty(object):
attribute_class = None
def __init__(self, path): def __init__(self, path):
""" """
:param path: string or callable :param path: string or callable
Usage: Abstract super class. Subclass and set the class member attribute_class accordingly.
Usage with a sublcass:
class Foo(object): class Foo(object):
parameters = DirectoryDictProperty(lambda obj: os.path.join(obj.absolute_path, 'parameter')) # note that the actual DirectoryDict is stored as __parameters on the instance
other_dict = DirectoryDictProperty('/tmp/folder') parameters = DirectoryDictProperty(lambda instance: os.path.join(instance.absolute_path, 'parameter'))
# note that the actual DirectoryDict is stored as __other_dict on the instance
other_dict = DirectoryDictProperty('/tmp/other_dict')
def __init__(self): def __init__(self):
self.absolute_path = '/tmp/foo' self.absolute_path = '/tmp/foo'
""" """
self.path = None self.path = path
self.__path = path
def _set_path(self, *args, **kwargs): def _get_path(self, instance):
#print("_set_path: self: %s" % self) path = self.path
print("_set_path: args: %s" % args) if callable(path):
print("_set_path: kwargs: %s" % kwargs) path = path(instance)
print("_set_path: self.path: %s" % self.path) return path
if self.path is None:
path = self.__path
if callable(path):
path = path(*args, **kwargs)
print("_set_path: %s" % path)
if not os.path.isabs(path):
raise AbsolutePathRequiredError(path)
# create directory if it doesn't exist
print("os.path.isdir(%s): %s" % (path, os.path.isdir(path)))
if not os.path.isdir(path):
os.mkdir(path)
self.path = path
# Descriptor Protocol def _get_property_name(self, owner):
def __get__(self, obj, objtype=None): for name, prop in owner.__dict__.items():
if obj is None: if self == prop:
return self.__class__ return name
self._set_path(obj)
return self
def __set__(self, obj, value): def _get_attribute(self, instance, owner):
self._set_path(obj) name = self._get_property_name(owner)
if value is not None: attribute_name = '__%s' % name
for name in self.keys(): if not hasattr(instance, attribute_name):
del self[name] path = self._get_path(instance)
self.update(value) attribute_instance = self.attribute_class(path)
setattr(instance, attribute_name, attribute_instance)
return getattr(instance, attribute_name)
def __delete__(self, obj): def __get__(self, instance, owner):
if instance is None:
return self
return self._get_attribute(instance, owner)
def __delete__(self, instance):
raise AttributeError("can't delete attribute") raise AttributeError("can't delete attribute")
class FileBooleanProperty(object): class DirectoryDictProperty(FileBasedProperty):
def __init__(self, path): attribute_class = DirectoryDict
"""
:param path: string or callable
Usage: def __set__(self, instance, value):
attribute_instance = self._get_attribute(instance, instance.__class__)
for name in attribute_instance.keys():
del attribute_instance[name]
attribute_instance.update(value)
class Foo(object):
changed = FileBoolean(lambda obj: os.path.join(obj.absolute_path, 'changed'))
other_boolean = FileBoolean('/tmp/other_boolean')
def __init__(self): class FileListProperty(FileBasedProperty):
self.absolute_path = '/tmp/foo_boolean' attribute_class = FileList
""" def __set__(self, instance, value):
self._path = path path = self._get_path(instance)
try:
os.unlink(path)
except EnvironmentError:
# ignored
pass
attribute_instance = self._get_attribute(instance, instance.__class__)
for item in value:
attribute_instance.append(item)
def _get_path(self, *args, **kwargs):
path = self._path
if callable(path):
return path(*args, **kwargs)
if not os.path.isabs(path):
raise AbsolutePathRequiredError(path)
return path
class FileBooleanProperty(FileBasedProperty):
"""A boolean property which uses a file to represent its value.
File exists -> True
File does not exists -> False
"""
# Descriptor Protocol # Descriptor Protocol
def __get__(self, obj, objtype=None): def __get__(self, instance, owner):
if obj is None: if instance is None:
return self.__class__ return self
path = self._get_path(obj) path = self._get_path(instance)
return os.path.isfile(path) return os.path.isfile(path)
def __set__(self, obj, value): def __set__(self, instance, value):
path = self._get_path(obj) path = self._get_path(instance)
if value: if value:
open(path, "w").close() open(path, "w").close()
else: else:
@ -285,42 +242,15 @@ class FileBooleanProperty(object):
# ignore # ignore
pass pass
def __delete__(self, obj):
raise AttributeError("can't delete attribute")
class FileStringProperty(FileBasedProperty):
class FileStringProperty(object):
"""A string property which stores its value in a file. """A string property which stores its value in a file.
""" """
def __init__(self, path):
"""
:param path: string or callable
Usage:
class Foo(object):
source = FileStringProperty(lambda obj: os.path.join(obj.absolute_path, 'source'))
other = FileStringProperty('/tmp/other')
def __init__(self):
self.absolute_path = '/tmp/foo_boolean'
"""
self._path = path
def _get_path(self, *args, **kwargs):
path = self._path
if callable(path):
return path(*args, **kwargs)
if not os.path.isabs(path):
raise AbsolutePathRequiredError(path)
return path
# Descriptor Protocol # Descriptor Protocol
def __get__(self, obj, objtype=None): def __get__(self, instance, owner):
if obj is None: if instance is None:
return self.__class__ return self
path = self._get_path(obj) path = self._get_path(instance)
value = "" value = ""
try: try:
with open(path, "r") as fd: with open(path, "r") as fd:
@ -329,16 +259,13 @@ class FileStringProperty(object):
pass pass
return value return value
def __set__(self, obj, value): def __set__(self, instance, value):
path = self._get_path(obj) path = self._get_path(instance)
if value: if value:
with open(path, "w") as fd: with open(path, "w") as fd:
fd.write(str(value)) fd.write(str(value))
else: else:
try: try:
os.unlink(path) os.remove(path)
except EnvironmentError: except EnvironmentError:
pass pass
def __delete__(self, obj):
raise AttributeError("Can't delete attribute. Set it's value to an empty string to remove the underlying file.")