def test_union_with_empty_sub_dict(self):
"""unioning with a dict that has an empty sub-dict"""
d = UnionDict({"title": {}})
e = UnionDict({"title": {"text": "Alignment Position"}})
f = UnionDict(e.copy())
e |= d
self.assertEqual(e, f)
def test_union_value_dict(self):
"""replacing union or of a value with a dict should be dict"""
d = UnionDict({"A": {"B": "Blah"}})
e = UnionDict({"A": "Blah"})
f = UnionDict(d.copy())
f |= e
self.assertNotEqual(d, f)
e |= d
self.assertEqual(d, e)
class ReadOnlyDataStoreBase:
"""a read only data store"""
store_suffix = None
def __init__(self,
source,
suffix=None,
limit=None,
verbose=False,
md5=True):
"""
Parameters
----------
source
path to directory / zip file. Forced to end with store_suffix.
suffix
only members whose name matches the suffix are considered included
limit
the maximum number of members to consider
verbose
displays files that don't match search (applies only to the Zipped
variant)
md5 : bool
record md5 hexadecimal checksum of read data when possible
"""
# assuming delimiter is /
# todo this approach to caching persistent arguments for reconstruction
# is fragile. Need an inspect module based approach
d = locals()
self._persistent = UnionDict(
{k: v
for k, v in d.items() if k != "self"})
source = str(source)
suffix = suffix or ""
if suffix != "*": # wild card search for all
suffix = re.sub(r"^[\s.*]+", "", suffix) # tidy the suffix
source = re.sub(r"/+$", "", source) # tidy the source
self.suffix = suffix
if self.store_suffix and not source.endswith(self.store_suffix):
source = ".".join([source, self.store_suffix])
self.source = str(pathlib.Path(source).expanduser())
self.mode = "r"
self._members = []
self.limit = limit
self._verbose = verbose
self._md5 = md5
self._checksums = {}
def __getstate__(self):
return self._persistent.copy()
def __setstate__(self, data):
new = self.__class__(**data)
self.__dict__.update(new.__dict__)
return self
def __repr__(self):
if len(self) > 3:
sample = str(list(self[:3]))
sample = f"{sample[:-1]}..."
else:
sample = list(self)
num = len(self)
name = self.__class__.__name__
return f"{num}x member {name}(source='{self.source}', members={sample})"
def __str__(self):
return str(list(self))
def head(self, n=5):
"""displays top n members"""
pprint(self[:n])
def tail(self, n=5):
"""displays last n members"""
pprint(self[-n:])
def __iter__(self):
for i, member in enumerate(self.members):
if not isinstance(member, DataStoreMember):
member = DataStoreMember(self.get_absolute_identifier(member),
self)
self.members[i] = member
yield member
def __getitem__(self, index):
return self.members[index]
def __len__(self):
return len(self.members)
def __contains__(self, identifier):
"""whether relative identifier has been stored"""
if isinstance(identifier, DataStoreMember):
return identifier.parent is self
if not identifier.endswith(self.suffix):
suffix = pathlib.Path(identifier).suffix
# possible an "added" file
if self.store_suffix == "zip":
klass = ReadOnlyZippedDataStore
else:
klass = ReadOnlyDirectoryDataStore
new = klass(self.source, suffix=suffix)
return identifier in new
identifier = self.get_relative_identifier(identifier)
result = False
for member in self.members:
if identifier in member:
result = True
break
return result
def get_member(self, identifier):
"""returns DataStoreMember"""
identifier = self.get_relative_identifier(identifier)
for member in self.members:
if identifier in member:
return member
return None
def get_relative_identifier(self, identifier):
"""returns the identifier relative to store root path"""
if isinstance(identifier,
DataStoreMember) and identifier.parent is self:
return identifier
source = self.source
identifier = os.path.basename(identifier)
if source.endswith(".zip"):
# we insert the source path into identifier name
# for zip members to ensure inflation creates a directory
# containing them
source = source.replace(".zip", "")
source = os.path.basename(source)
identifier = f"{source}{os.sep}{identifier}"
else:
identifier = Path(identifier)
identifier = identifier.name
return identifier
def get_absolute_identifier(self, identifier, from_relative=False):
"""returns the identifier relative to the root path"""
if not from_relative:
identifier = self.get_relative_identifier(identifier)
source = self.source.replace(".zip", "")
if isinstance(identifier, DataStoreMember):
identifier = identifier.name
elif not identifier.startswith(source):
identifier = f"{source}{os.sep}{identifier}"
return identifier
def read(self, identifier):
"""reads data corresponding to identifier"""
if isinstance(identifier,
DataStoreMember) and identifier.parent is self:
identifier = identifier.name
source = self.open(identifier)
data = source.read()
if self._md5:
self._checksums[identifier] = get_text_hexdigest(data)
source.close()
return data
@property
def members(self):
raise NotImplementedError # override in subclasses
def open(self, identifier):
raise NotImplementedError
def filtered(self, pattern=None, callback=None):
"""returns list of members for which callback returns True"""
assert any([callback, pattern]), "Must provide a pattern or a callback"
if pattern:
result = [m for m in self if fnmatch(m, pattern)]
else:
result = [m for m in self if callback(m)]
return result
def md5(self, identifier, force=True):
"""
Parameters
----------
identifier
name of data store member
force : bool
forces reading of data if not already done
Returns
-------
md5 checksum for the member, if available, None otherwise
"""
md5_setting = self._md5 # for restoring automatic md5 calc setting
absoluteid = self.get_absolute_identifier(identifier)
if force and absoluteid not in self._checksums:
self._md5 = True
_ = self.read(absoluteid)
result = self._checksums.get(absoluteid, None)
self._md5 = md5_setting
return result
