Update README

README.md

@@ -38,7 +38,7 @@ app.run()
 
 ### Redis support
 
-via `aioredis` or `trio-redis` (when using [Trio](https://trio.readthedocs.io/en/stable/)).
+via `aioredis`.
 
 ```python3
 app = Quart(__name__)
@@ -60,11 +60,21 @@ async def setup():
     Session(app)
 ```
 
-#### Trio
+By default, Quart-session creates a single connection to Redis, while
+the example above creates a connection pool.
 
-Quart-Session comes with a Redis client for use with the [Trio](https://trio.readthedocs.io/en/stable/) eventloop.
+#### Trio support
 
+Quart-Session comes with [an (experimental) Redis client](quart_session/redis_trio) for use with the [Trio](https://trio.readthedocs.io/en/stable/) eventloop.
 
+```python3
+from quart_trio import QuartTrio
+from quart_session.redis_trio.client import RedisTrio
+
+app = QuartTrio(__name__)
+app.config['SESSION_TYPE'] = 'redis'
+Session(app)
+```
 
 ### Memcached support
 
@@ -85,9 +95,9 @@ for session data, Quart-Session opts for a JSON serializer capable of
 
 JSON as session data allows for greater interoperability with other
 programs/languages that might want to read session data straight
-from a back-end. In addition, it is more secure.
+from a back-end.
 
-If, for some unholy reason, you prefer `pickle` or your own serializer,
+If ~~for some unholy reason~~ you prefer `pickle` or your own serializer,
 
 ```python3
 app = Quart(__name__)
@@ -181,7 +191,7 @@ straightforward. The distinct changes are specified below:
 - Quart-Session does not `Set-Cookie` on (static) files by default.
 - Quart-Session might not have all the back-end interfaces implemented (yet), such as "filesystem".
 - Quart-Session uses a different serializer: `quart.json.tag.TaggedJSONSerializer` instead of `pickle`.
-- Quart-Session uses asyncio ;-)
+- Quart-Session disallows the client to supply their own made up `sid` cookie value.
 
 ## Help
 

quart_session/__init__.py

@@ -13,11 +13,12 @@
 __version__ = '0.0.1'
 
 import os
+import sniffio
 from typing import Optional
 
 from quart import Quart
 
-from .sessions import RedisSessionInterface, MemcachedSessionInterface, NullSessionInterface
+from .sessions import RedisSessionInterface, RedisTrioSessionInterface, MemcachedSessionInterface, NullSessionInterface
 
 
 class Session(object):
@@ -51,6 +52,7 @@ class Session(object):
     """
 
     def __init__(self, app: Quart = None) -> None:
+        self._current_async_library = "asyncio"
         self.app = app
         if app is not None:
             self.init_app(app)
@@ -60,6 +62,12 @@ class Session(object):
 
         :param app: the Quart app object with proper configuration.
         """
+        try:
+            import quart_trio
+            if isinstance(app, quart_trio.QuartTrio):
+                self._current_async_library = "trio"
+        except ImportError:
+            pass
         app.session_interface = self._get_interface(app)
 
         @app.before_serving
@@ -85,12 +93,29 @@ class Session(object):
         config = {k: v for k, v in config.items() if k.startswith('SESSION_')}
 
         if config['SESSION_TYPE'] == 'redis':
-            session_interface = RedisSessionInterface(
+            options = {
+                "redis": config['SESSION_REDIS'],
+                "key_prefix": config['SESSION_KEY_PREFIX'],
+                "use_signer": config['SESSION_USE_SIGNER'],
+                "permanent": config['SESSION_PERMANENT'],
+                **config
+            }
+
+            if self._current_async_library == "asyncio":
+                session_interface = RedisSessionInterface(**options)
+            elif self._current_async_library == "trio":
+                session_interface = RedisTrioSessionInterface(**options)
+            else:
+                raise NotImplementedError("Unknown eventloop")
+
+        elif config['SESSION_TYPE'] == 'redis+trio':
+            session_interface = RedisTrioSessionInterface(
                 redis=config['SESSION_REDIS'],
                 key_prefix=config['SESSION_KEY_PREFIX'],
                 use_signer=config['SESSION_USE_SIGNER'],
-                permanent=config['SESSION_PERMANENT'],
+                premanent=config['SESSION_PERMANENT'],
-                **config)
+                **config
+            )
         elif config['SESSION_TYPE'] == 'memcached':
             session_interface = MemcachedSessionInterface(
                 memcached=config['SESSION_MEMCACHED'],

quart_session/redis_trio/README.md

@@ -0,0 +1,37 @@
+
+
+Code here is borrowed from [alekseyev/trio-redis](https://github.com/alekseyev/trio-redis), which was originally developed over at [Bogdanp/trio-redis](https://github.com/Bogdanp/trio-redis).
+
+Since it has no active maintainers and no PyPI package - I am including it as-is.
+
+## Usage
+
+```python3
+from quart_session.redis_trio import RedisTrio
+cache = RedisTrio(
+    addr=b"10.0.0.3", port=6379, password=b"foo")
+await cache.connect()
+
+await cache.setex(key="foo", value=42, seconds=300)
+await cache.get("foo")
+```
+
+Or,
+
+```python3
+async with RedisTrio() as cache:
+    await cache.set("foo", 42)
+    await cache.get("foo")
+```
+
+## Future work
+
+If someone makes a Redis+Trio client that supports connection pooling, we can switch to it.
+
+
+```
+:copyright: (c) 2017 by Bogdan Paul Popa.
+:copyright: (c) 2019 by Oleksii Aleksieiev.
+:copyright: (c) 2020 by dsc.
+:license: BSD, see LICENSE for more
+```

quart_session/redis_trio/__init__.py

@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+"""
+    quart_session.redis_trio
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    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 quart_session.redis_trio.client import RedisTrio

quart_session/redis_trio/client.py

@@ -0,0 +1,88 @@
+# -*- coding: utf-8 -*-
+"""
+    quart_session.redis_trio
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    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 typing import Union
+
+from .connection import RedisConnection
+
+
+class RedisTrio:
+    """A simple Redis+Trio client.
+
+    Parameters:
+      addr(str): The IP address the Redis server is listening on.
+      port(int): The port the Redis server is listening on.
+
+    Examples:
+
+      >>> async with RedisTrio() as redis:
+      ...   await redis.set("foo", 42)
+      ...   await redis.get("foo")
+      b'42'
+    """
+
+    def __init__(self, addr: Union[bytes, str] = b"127.0.0.1", port: int = 6379, password: bytes = b""):
+        self.conn = RedisConnection(addr, port)
+        self.password = password
+
+    async def connect(self):
+        """Open a connection to the Redis server.
+
+        Returns:
+          RedisTrio: This instance.
+        """
+        await self.conn.connect()
+        if self.password:
+            await self.auth(self.password)
+        return self
+
+    async def close(self):
+        """Close the connection to the Redis server.
+        """
+        await self.quit()
+        self.conn.close()
+
+    async def auth(self, password):
+        return await self.conn.process_command_ok(b"AUTH", password)
+
+    async def delete(self, *keys):
+        return await self.conn.process_command(b"DEL", *keys)
+
+    async def echo(self, message):
+        return await self.conn.process_command(b"ECHO", message)
+
+    async def flushall(self):
+        return await self.conn.process_command_ok(b"FLUSHALL")
+
+    async def get(self, key) -> bytes:
+        return await self.conn.process_command(b"GET", key)
+
+    async def quit(self):
+        return await self.conn.process_command(b"QUIT")
+
+    async def set(self, key, value):
+        return await self.conn.process_command_ok(b"SET", key, value)
+
+    async def setex(self, key: str, value: str, seconds: int):
+        """Set the value and expiration of a key.
+        :raises TypeError: if seconds is not int
+        """
+        if not isinstance(seconds, int):
+            raise TypeError("milliseconds argument must be int")
+
+        return await self.conn.process_command_ok(b"SETEX", key, seconds, value)
+
+    async def __aenter__(self):
+        return await self.connect()
+
+    async def __aexit__(self, exc_type, exc_value, traceback):
+        self.close()

quart_session/redis_trio/connection.py

@@ -0,0 +1,136 @@
+# -*- coding: utf-8 -*-
+"""
+    quart_session.redis_trio.connection
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    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 typing import Union
+
+import trio
+
+from .serialization import atom, serialize
+from .errors import ProtocolError, ResponseError, ResponseTypeError
+
+
+SP = ord("+")
+EP = ord("-")
+IP = ord(":")
+BP = ord("$")
+AP = ord("*")
+
+#: The set of known Redis response prefixes.
+known_prefixes = {SP, EP, IP, BP, AP}
+
+
+class ReadMore(Exception):
+    """Raised by parse to signal that it needs more data.
+    """
+
+
+class RedisConnection:
+    """This class facilitates all communication with Redis via a trio socket.
+    Warning:
+      The interface of this class may change at any time, without
+      notice, due to the experimental nature of Trio.
+    """
+
+    def __init__(self, addr: Union[bytes, str], port: int, bufsize: int = 16384):
+        self.addr = (addr, port)
+        self.sock = trio.socket.socket()
+        self.bufsize = bufsize
+
+    async def connect(self):
+        await self.sock.connect(self.addr)
+
+    def close(self):
+        self.sock.close()
+
+    async def send_command(self, command, *args):
+        command_and_args = (serialize(arg) for arg in (atom(command),) + args)
+        data = b" ".join(command_and_args) + b"\r\n"
+        await self.sock.send(data)
+
+    async def process_command(self, *command_and_args):
+        await self.send_command(*command_and_args)
+        return await self.process_response()
+
+    async def process_command_ok(self, *command_and_args):
+        await self.send_command(*command_and_args)
+        return await self.process_response() == b"OK"
+
+    async def process_response(self):
+        data = await self.sock.recv(self.bufsize)
+        while True:
+            try:
+                item, _ = await self.parse(data)
+                return item
+            except ReadMore:
+                data += await self.sock.recv(self.bufsize)
+
+    async def parse(self, data):
+        try:
+            index = data.index(b"\r\n")
+        except ValueError:
+            raise ReadMore()
+
+        if data[0] not in known_prefixes:
+            raise ProtocolError(f"Unexpected data in response: {data!r}.")
+
+        elif data[0] == SP:
+            return data[1:index], data[index + 2:]
+
+        elif data[0] == EP:
+            error = data[1:index].decode("ascii")
+            if error.startswith("WRONGTYPE"):
+                raise ResponseTypeError(error[len("WRONGTYPE "):])
+
+            elif error.startswith("ERR"):
+                raise ResponseError(error[len("ERR "):])
+
+            else:
+                raise ResponseError(error)
+
+        elif data[0] == IP:
+            return int(data[1:index]), data[index + 2:]
+
+        elif data[0] == BP:
+            length, data = int(data[1:index]), data[index + 2:]
+            if length == -1:
+                return None, data
+
+            elif len(data) < length + 2:
+                raise ReadMore()
+
+            return data[:length], data[length + 2:]
+
+        elif data[0] == AP:
+            length, data = int(data[1:index]), data[index + 2:]
+            if length == -1:
+                return None, data
+
+            return await self.parse_array(length, data)
+
+        else:  # pragma: no cover
+            assert False, "unreachable"
+
+    async def parse_array(self, length, data):
+        items = []
+        while len(items) < length:
+            if not data:
+                data += await self.sock.recv(self.bufsize)
+                continue
+
+            try:
+                item, data = await self.parse(data)
+                items.append(item)
+            except ReadMore:
+                data += await self.sock.recv(self.bufsize)
+
+        return items, data

quart_session/redis_trio/errors.py

@@ -0,0 +1,33 @@
+# -*- coding: utf-8 -*-
+"""
+    quart_session.redis_trio.errors
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    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.
+"""
+
+
+class RedisError(Exception):
+    """Base class for all Redis-related errors.
+    """
+
+
+class ProtocolError(RedisError):
+    """Raised when Redis responds with something that doesn't conform
+    to the protocol.
+    """
+
+
+class ResponseError(RedisError):
+    """Raised when Redis returns an error response.
+    """
+
+
+class ResponseTypeError(ResponseError):
+    """Raised when Redis returns an error response with a `WRONGTYPE` prefix.
+    """

quart_session/redis_trio/serialization.py

@@ -0,0 +1,60 @@
+# -*- 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

quart_session/sessions.py

@@ -100,7 +100,9 @@ class SessionInterface(QuartSessionInterface):
         self._config = kwargs
 
     async def open_session(
-            self, app: Quart, request: BaseRequestWebsocket
+            self,
+            app: Quart,
+            request: BaseRequestWebsocket
     ) -> Optional[SecureCookieSession]:
         sid = request.cookies.get(app.session_cookie_name)
         addr = request.headers.get('X-Forwarded-For', request.remote_addr) if \
@@ -137,10 +139,7 @@ class SessionInterface(QuartSessionInterface):
             return self.session_class(**options)
 
         prevent_hijack = self._config['SESSION_HIJACK_PROTECTION']
-        if prevent_hijack is False:
+        if prevent_hijack is True:
-            pass
-        elif isinstance(prevent_hijack, bool) and \
-                prevent_hijack is True:
             if self._config['SESSION_HIJACK_REVERSE_PROXY'] is True:
                 addr = request.headers.get('X-Forwarded-For', request.remote_addr)
             else:
@@ -160,12 +159,12 @@ class SessionInterface(QuartSessionInterface):
         response: Response
     ) -> None:
         # prevent set-cookie
-        # motivation: https://github.com/fengsp/flask-session/pull/70
         if self._config['SESSION_EXPLICIT'] is True and \
                 not session._dirty:
             return
 
         # prevent set-cookie on (static) file responses
+        # https://github.com/fengsp/flask-session/pull/70
         if self._config['SESSION_STATIC_FILE'] is False and \
                 isinstance(response.response, FileBody):
             return
@@ -226,15 +225,18 @@ class RedisSessionInterface(SessionInterface):
 
     session_class = RedisSession
 
-    def __init__(
+    def __init__(self, redis, **kwargs):
-            self, redis, key_prefix: str, use_signer: bool = False,
+        super(RedisSessionInterface, self).__init__(**kwargs)
-            permanent: bool = True, **kwargs):
-        super(RedisSessionInterface, self).__init__(
-            key_prefix=key_prefix, use_signer=use_signer,
-            permanent=permanent, **kwargs)
         self.redis = redis
 
     async def create(self, app: Quart) -> None:
+        """Creates ``aioredis.Redis`` instance.
+
+        .. note::
+
+            Creates a single Redis connection, you might prefer
+            pooling instead (see ``aioredis.Redis.create_redis_pool``)
+        """
         if self.redis is None:
             import aioredis
             self.redis = await aioredis.create_redis("redis://localhost")
@@ -251,6 +253,49 @@ class RedisSessionInterface(SessionInterface):
         return await self.redis.delete(key)
 
 
+class RedisTrioSessionInterface(SessionInterface):
+    """Uses the Redis+Trio key-value store as a session backend.
+
+    :param redis: ``quart_session.redis_trio.RedisTrio`` instance.
+    :param key_prefix: A prefix that is added to all Redis store keys.
+    :param use_signer: Whether to sign the session id cookie or not.
+    :param permanent: Whether to use permanent session or not.
+    :param kwargs: Quart-session config, used internally.
+    """
+
+    session_class = RedisSession
+
+    def __init__(self, redis, **kwargs):
+        super(RedisTrioSessionInterface, self).__init__(**kwargs)
+        self.redis_trio = redis
+
+    async def create(self, app: Quart) -> None:
+        """Creates ``aioredis.Redis`` instance.
+
+        .. note::
+
+            Creates a single Redis connection. Pooling not
+            supported yet for ``RedisTrio``.
+        """
+        if self.redis_trio is None:
+            from quart_session.redis_trio import RedisTrio
+            self.redis_trio = RedisTrio()
+            await self.redis_trio.connect()
+
+    async def _backend_get(self, app: Quart, key: str):
+        data = await self.redis_trio.get(key)
+        if data:
+            return data.decode()
+
+    async def _backend_set(self, app: Quart, key: str, value):
+        return await self.redis_trio.setex(
+            key=key, value=value,
+            seconds=total_seconds(app.permanent_session_lifetime))
+
+    async def _backend_delete(self, app: Quart, key: str):
+        return await self.redis_trio.delete(key)
+
+
 class MemcachedSessionInterface(SessionInterface):
     """Uses the Memcached key-value store as a session backend.