def _create_index_name(self, model, column_names, suffix=""):
"""
Generates a unique name for an index/unique constraint.
"""
# If there is just one column in the index, use a default algorithm from Django
if len(column_names) == 1 and not suffix:
return truncate_name(
'%s_%s' %
(model._meta.db_table, self._digest(column_names[0])),
self.connection.ops.max_name_length())
# Else generate the name for the index using a different algorithm
table_name = model._meta.db_table.replace('"', '').replace('.', '_')
index_unique_name = '_%s' % self._digest(table_name, *column_names)
max_length = self.connection.ops.max_name_length() or 200
# If the index name is too long, truncate it
index_name = ('%s_%s%s%s' % (
table_name,
column_names[0],
index_unique_name,
suffix,
)).replace('"', '').replace('.', '_')
if len(index_name) > max_length:
part = ('_%s%s%s' % (column_names[0], index_unique_name, suffix))
index_name = '%s%s' % (table_name[:(max_length - len(part))], part)
# It shouldn't start with an underscore (Oracle hates this)
if index_name[0] == "_":
index_name = index_name[1:]
# If it's STILL too long, just hash it down
if len(index_name) > max_length:
index_name = hashlib.md5(
force_bytes(index_name)).hexdigest()[:max_length]
# It can't start with a number on Oracle, so prepend D if we need to
if index_name[0].isdigit():
index_name = "D%s" % index_name[:-1]
return index_name
def get(self, key, default=None, version=None):
key = self.make_key(key, version=version)
self.validate_key(key)
db = router.db_for_read(self.cache_model_class)
connection = connections[db]
table = connection.ops.quote_name(self._table)
with connection.cursor() as cursor:
cursor.execute(
"SELECT cache_key, value, expires FROM %s "
"WHERE cache_key = %%s" % table, [key])
row = cursor.fetchone()
if row is None:
return default
expires = row[2]
expression = models.Expression(output_field=models.DateTimeField())
for converter in (connection.ops.get_db_converters(expression) +
expression.get_db_converters(connection)):
expires = converter(expires, expression, connection, {})
if expires < timezone.now():
db = router.db_for_write(self.cache_model_class)
connection = connections[db]
with connection.cursor() as cursor:
cursor.execute(
"DELETE FROM %s "
"WHERE cache_key = %%s" % table, [key])
return default
value = connection.ops.process_clob(row[1])
return pickle.loads(base64.b64decode(force_bytes(value)))
def truncate_name(name, length=None, hash_len=4):
"""Shortens a string to a repeatable mangled version with the given length.
"""
if length is None or len(name) <= length:
return name
hsh = hashlib.md5(force_bytes(name)).hexdigest()[:hash_len]
return '%s%s' % (name[:length - hash_len], hsh)
def __init__(self, content, name=None):
if six.PY3:
stream_class = StringIO if isinstance(content,
six.text_type) else BytesIO
else:
stream_class = BytesIO
content = force_bytes(content)
super(ContentFile, self).__init__(stream_class(content), name=name)
self.size = len(content)
def _digest(cls, *args):
"""
Generates a 32-bit digest of a set of arguments that can be used to
shorten identifying names.
"""
h = hashlib.md5()
for arg in args:
h.update(force_bytes(arg))
return h.hexdigest()[:8]
def urlsafe_base64_decode(s):
"""
Decodes a base64 encoded string, adding back any trailing equal signs that
might have been stripped.
"""
s = force_bytes(s)
try:
return base64.urlsafe_b64decode(s.ljust(len(s) + len(s) % 4, b'='))
except (LookupError, BinasciiError) as e:
raise ValueError(e)
def _key_to_file(self, key, version=None):
"""
Convert a key into a cache file path. Basically this is the
root cache path joined with the md5sum of the key and a suffix.
"""
key = self.make_key(key, version=version)
self.validate_key(key)
return os.path.join(
self._dir, ''.join(
[hashlib.md5(force_bytes(key)).hexdigest(),
self.cache_suffix]))
def __init__(self, param, cursor, strings_only=False):
# With raw SQL queries, datetimes can reach this function
# without being converted by DateTimeField.get_db_prep_value.
if settings.USE_TZ and (isinstance(param, datetime.datetime) and
not isinstance(param, Oracle_datetime)):
if timezone.is_aware(param):
warnings.warn(
"The Oracle database adapter received an aware datetime (%s), "
"probably from cursor.execute(). Update your code to pass a "
"naive datetime in the database connection's time zone (UTC by "
"default).", RemovedInDjango20Warning)
param = param.astimezone(timezone.utc).replace(tzinfo=None)
param = Oracle_datetime.from_datetime(param)
if isinstance(param, datetime.timedelta):
param = duration_string(param)
if ' ' not in param:
param = '0 ' + param
string_size = 0
# Oracle doesn't recognize True and False correctly in Python 3.
# The conversion done below works both in 2 and 3.
if param is True:
param = 1
elif param is False:
param = 0
if hasattr(param, 'bind_parameter'):
self.force_bytes = param.bind_parameter(cursor)
elif isinstance(param, Database.Binary):
self.force_bytes = param
else:
# To transmit to the database, we need Unicode if supported
# To get size right, we must consider bytes.
self.force_bytes = convert_unicode(param, cursor.charset, strings_only)
if isinstance(self.force_bytes, six.string_types):
# We could optimize by only converting up to 4000 bytes here
string_size = len(force_bytes(param, cursor.charset, strings_only))
if hasattr(param, 'input_size'):
# If parameter has `input_size` attribute, use that.
self.input_size = param.input_size
elif string_size > 4000:
# Mark any string param greater than 4000 characters as a CLOB.
self.input_size = Database.CLOB
else:
self.input_size = None
def make_template_fragment_key(fragment_name, vary_on=None):
if vary_on is None:
vary_on = ()
key = ':'.join(urlquote(var) for var in vary_on)
args = hashlib.md5(force_bytes(key))
return TEMPLATE_FRAGMENT_KEY_TEMPLATE % (fragment_name, args.hexdigest())
def convert_binaryfield_value(self, value, expression, connection, context):
if isinstance(value, Database.LOB):
value = force_bytes(value.read())
return value