Files
quart-session/quart_session/redis_trio/serialization.py
T
2020-12-09 15:39:42 +01:00

61 lines
1.3 KiB
Python

# -*- coding: utf-8 -*-
"""
quart_session.redis_trio.serialization
~~~~~~~~~~~~~~~~~~~~~~
A simple Redis Trio client.
:copyright: (c) 2017 by Bogdan Paul Popa.
:copyright: (c) 2019 by Oleksii Aleksieiev.
:copyright: (c) 2020 by dsc.
:license: BSD, see LICENSE for more details.
"""
from collections import namedtuple
#: Wrapper class for values that don't have to be quoted.
atom = namedtuple("atom", ("value",))
#: The set of characters that must be escaped before being sent as
#: Redis strings.
escapes = {
ord(b"\0"): rb"\x00",
ord(b"\n"): rb"\n",
ord(b"\r"): rb"\r",
ord(b"\\"): rb"\\",
ord(b'"'): rb'\"',
}
def serialize(x):
"""Serialize `x` so that it can safely be sent to Redis.
Parameters:
x(object): The value to serialize.
Returns:
bytes: The serialized value.
"""
if isinstance(x, atom):
return x.value
elif isinstance(x, bytes):
return quote(x)
elif isinstance(x, str):
return quote(x.encode("utf-8"))
elif isinstance(x, (float, int)):
return str(x).encode("ascii")
else:
return serialize(str(x))
def quote(bs):
return b'"' + bytes(escape(bs)) + b'"'
def escape(bs):
for c in bs:
if c in escapes:
yield from escapes[c]
else:
yield c