import asyncio
import copy
import enum
import inspect
import socket
import ssl
import sys
import warnings
import weakref
from abc import abstractmethod
from itertools import chain
from typing import (
Any,
Iterable,
List,
Mapping,
Optional,
Protocol,
Set,
Tuple,
Type,
TypedDict,
TypeVar,
Union,
)
from ..utils import format_error_message
# the functionality is available in 3.11.x but has a major issue before
# 3.11.3. See https://github.com/redis/redis-py/issues/2633
if sys.version_info >= (3, 11, 3):
from asyncio import timeout as async_timeout
else:
from async_timeout import timeout as async_timeout
from valkey.asyncio.retry import Retry
from valkey.backoff import NoBackoff
from valkey.connection import DEFAULT_RESP_VERSION
from valkey.credentials import CredentialProvider, UsernamePasswordCredentialProvider
from valkey.exceptions import (
AuthenticationError,
AuthenticationWrongNumberOfArgsError,
ConnectionError,
DataError,
ResponseError,
TimeoutError,
ValkeyError,
)
from valkey.typing import EncodableT, KeysT, ResponseT
from valkey.utils import LIBVALKEY_AVAILABLE, get_lib_version, str_if_bytes
from .._cache import (
DEFAULT_ALLOW_LIST,
DEFAULT_DENY_LIST,
DEFAULT_EVICTION_POLICY,
AbstractCache,
_LocalCache,
)
from .._parsers import (
BaseParser,
Encoder,
_AsyncLibvalkeyParser,
_AsyncRESP2Parser,
_AsyncRESP3Parser,
)
SYM_STAR = b"*"
SYM_DOLLAR = b"$"
SYM_CRLF = b"\r\n"
SYM_LF = b"\n"
SYM_EMPTY = b""
def parse_url(url: str):
from .._parsers.url_parser import parse_url
return parse_url(url, async_connection=True)
class _Sentinel(enum.Enum):
sentinel = object()
SENTINEL = _Sentinel.sentinel
DefaultParser: Type[Union[_AsyncRESP2Parser, _AsyncRESP3Parser, _AsyncLibvalkeyParser]]
if LIBVALKEY_AVAILABLE:
DefaultParser = _AsyncLibvalkeyParser
else:
DefaultParser = _AsyncRESP2Parser
class ConnectCallbackProtocol(Protocol):
def __call__(self, connection: "AbstractConnection"): ...
class AsyncConnectCallbackProtocol(Protocol):
async def __call__(self, connection: "AbstractConnection"): ...
ConnectCallbackT = Union[ConnectCallbackProtocol, AsyncConnectCallbackProtocol]
class AbstractConnection:
"""Manages communication to and from a Valkey server"""
__slots__ = (
"db",
"username",
"client_name",
"lib_name",
"lib_version",
"credential_provider",
"password",
"socket_timeout",
"socket_connect_timeout",
"valkey_connect_func",
"retry_on_timeout",
"retry_on_error",
"health_check_interval",
"next_health_check",
"last_active_at",
"encoder",
"ssl_context",
"protocol",
"client_cache",
"cache_deny_list",
"cache_allow_list",
"_reader",
"_writer",
"_parser",
"_connect_callbacks",
"_buffer_cutoff",
"_lock",
"_socket_read_size",
"__dict__",
)
def __init__(
self,
*,
db: Union[str, int] = 0,
password: Optional[str] = None,
socket_timeout: Optional[float] = 5,
socket_connect_timeout: Optional[float] = None,
retry_on_timeout: bool = False,
retry_on_error: Union[list, _Sentinel] = SENTINEL,
encoding: str = "utf-8",
encoding_errors: str = "strict",
decode_responses: bool = False,
parser_class: Type[BaseParser] = DefaultParser,
socket_read_size: int = 65536,
health_check_interval: float = 0,
client_name: Optional[str] = None,
lib_name: Optional[str] = "valkey-py",
lib_version: Optional[str] = get_lib_version(),
username: Optional[str] = None,
retry: Optional[Retry] = None,
valkey_connect_func: Optional[ConnectCallbackT] = None,
encoder_class: Type[Encoder] = Encoder,
credential_provider: Optional[CredentialProvider] = None,
protocol: Optional[int] = 2,
cache_enabled: bool = False,
client_cache: Optional[AbstractCache] = None,
cache_max_size: int = 10000,
cache_ttl: int = 0,
cache_policy: str = DEFAULT_EVICTION_POLICY,
cache_deny_list: List[str] = DEFAULT_DENY_LIST,
cache_allow_list: List[str] = DEFAULT_ALLOW_LIST,
):
if (username or password) and credential_provider is not None:
raise DataError(
"'username' and 'password' cannot be passed along with 'credential_"
"provider'. Please provide only one of the following arguments: \n"
"1. 'password' and (optional) 'username'\n"
"2. 'credential_provider'"
)
self.db = db
self.client_name = client_name
self.lib_name = lib_name
self.lib_version = lib_version
self.credential_provider = credential_provider
self.password = password
self.username = username
self.socket_timeout = socket_timeout
if socket_connect_timeout is None:
socket_connect_timeout = socket_timeout
self.socket_connect_timeout = socket_connect_timeout
self.retry_on_timeout = retry_on_timeout
if retry_on_error is SENTINEL:
retry_on_error = []
if retry_on_timeout:
retry_on_error.append(TimeoutError)
retry_on_error.append(socket.timeout)
retry_on_error.append(asyncio.TimeoutError)
self.retry_on_error = retry_on_error
if retry or retry_on_error:
if not retry:
self.retry = Retry(NoBackoff(), 1)
else:
# deep-copy the Retry object as it is mutable
self.retry = copy.deepcopy(retry)
# Update the retry's supported errors with the specified errors
self.retry.update_supported_errors(retry_on_error)
else:
self.retry = Retry(NoBackoff(), 0)
self.health_check_interval = health_check_interval
self.next_health_check: float = -1
self.encoder = encoder_class(encoding, encoding_errors, decode_responses)
self.valkey_connect_func = valkey_connect_func
self._reader: Optional[asyncio.StreamReader] = None
self._writer: Optional[asyncio.StreamWriter] = None
self._socket_read_size = socket_read_size
self.set_parser(parser_class)
self._connect_callbacks: List[weakref.WeakMethod[ConnectCallbackT]] = []
self._buffer_cutoff = 6000
try:
p = int(protocol)
except TypeError:
p = DEFAULT_RESP_VERSION
except ValueError:
raise ConnectionError("protocol must be an integer")
finally:
if p < 2 or p > 3:
raise ConnectionError("protocol must be either 2 or 3")
self.protocol = protocol
if cache_enabled:
_cache = _LocalCache(cache_max_size, cache_ttl, cache_policy)
else:
_cache = None
self.client_cache = client_cache if client_cache is not None else _cache
if self.client_cache is not None:
if self.protocol not in [3, "3"]:
raise ValkeyError(
"client caching is only supported with protocol version 3 or higher"
)
self.cache_deny_list = cache_deny_list
self.cache_allow_list = cache_allow_list
def __del__(self, _warnings: Any = warnings):
# For some reason, the individual streams don't get properly garbage
# collected and therefore produce no resource warnings. We add one
# here, in the same style as those from the stdlib.
if getattr(self, "_writer", None):
_warnings.warn(
f"unclosed Connection {self!r}", ResourceWarning, source=self
)
self._close()
def _close(self):
"""
Internal method to silently close the connection without waiting
"""
if self._writer:
try:
self._writer.close()
self._writer = self._reader = None
# raised if the event loop is already closed
except RuntimeError: # noqa
pass
def __repr__(self):
repr_args = ",".join((f"{k}={v}" for k, v in self.repr_pieces()))
return f"<{self.__class__.__module__}.{self.__class__.__name__}({repr_args})>"
@abstractmethod
def repr_pieces(self):
pass
@property
def is_connected(self):
return self._reader is not None and self._writer is not None
def register_connect_callback(self, callback):
"""
Register a callback to be called when the connection is established either
initially or reconnected. This allows listeners to issue commands that
are ephemeral to the connection, for example pub/sub subscription or
key tracking. The callback must be a _method_ and will be kept as
a weak reference.
"""
wm = weakref.WeakMethod(callback)
if wm not in self._connect_callbacks:
self._connect_callbacks.append(wm)
def deregister_connect_callback(self, callback):
"""
De-register a previously registered callback. It will no-longer receive
notifications on connection events. Calling this is not required when the
listener goes away, since the callbacks are kept as weak methods.
"""
try:
self._connect_callbacks.remove(weakref.WeakMethod(callback))
except ValueError:
pass
def set_parser(self, parser_class: Type[BaseParser]) -> None:
"""
Creates a new instance of parser_class with socket size:
_socket_read_size and assigns it to the parser for the connection
:param parser_class: The required parser class
"""
self._parser = parser_class(socket_read_size=self._socket_read_size)
async def connect(self):
"""Connects to the Valkey server if not already connected"""
if self.is_connected:
return
try:
await self.retry.call_with_retry(
lambda: self._connect(), lambda error: self.disconnect()
)
except asyncio.CancelledError:
raise # in 3.7 and earlier, this is an Exception, not BaseException
except (socket.timeout, asyncio.TimeoutError):
raise TimeoutError("Timeout connecting to server")
except OSError as e:
raise ConnectionError(self._error_message(e))
except Exception as exc:
raise ConnectionError(exc) from exc
try:
if not self.valkey_connect_func:
# Use the default on_connect function
await self.on_connect()
else:
# Use the passed function valkey_connect_func
(
await self.valkey_connect_func(self)
if asyncio.iscoroutinefunction(self.valkey_connect_func)
else self.valkey_connect_func(self)
)
except ValkeyError:
# clean up after any error in on_connect
await self.disconnect()
raise
# run any user callbacks. right now the only internal callback
# is for pubsub channel/pattern resubscription
# first, remove any dead weakrefs
self._connect_callbacks = [ref for ref in self._connect_callbacks if ref()]
for ref in self._connect_callbacks:
callback = ref()
task = callback(self)
if task and inspect.isawaitable(task):
await task
@abstractmethod
async def _connect(self):
pass
@abstractmethod
def _host_error(self) -> str:
pass
def _error_message(self, exception: BaseException) -> str:
return format_error_message(self._host_error(), exception)
async def on_connect(self) -> None:
"""Initialize the connection, authenticate and select a database"""
self._parser.on_connect(self)
parser = self._parser
auth_args = None
# if credential provider or username and/or password are set, authenticate
if self.credential_provider or (self.username or self.password):
cred_provider = (
self.credential_provider
or UsernamePasswordCredentialProvider(self.username, self.password)
)
auth_args = cred_provider.get_credentials()
# if resp version is specified and we have auth args,
# we need to send them via HELLO
if auth_args and self.protocol not in [2, "2"]:
if isinstance(self._parser, _AsyncRESP2Parser):
self.set_parser(_AsyncRESP3Parser)
# update cluster exception classes
self._parser.EXCEPTION_CLASSES = parser.EXCEPTION_CLASSES
self._parser.on_connect(self)
if len(auth_args) == 1:
auth_args = ["default", auth_args[0]]
await self.send_command("HELLO", self.protocol, "AUTH", *auth_args)
response = await self.read_response()
if response.get(b"proto") != int(self.protocol) and response.get(
"proto"
) != int(self.protocol):
raise ConnectionError("Invalid RESP version")
# avoid checking health here -- PING will fail if we try
# to check the health prior to the AUTH
elif auth_args:
await self.send_command("AUTH", *auth_args, check_health=False)
try:
auth_response = await self.read_response()
except AuthenticationWrongNumberOfArgsError:
# a username and password were specified but the server seems
# to be < 6.0.0 which expects a single password arg.
# retry auth with just the password.
# https://github.com/andymccurdy/redis-py/issues/1274
await self.send_command("AUTH", auth_args[-1], check_health=False)
auth_response = await self.read_response()
if str_if_bytes(auth_response) != "OK":
raise AuthenticationError("Invalid Username or Password")
# if resp version is specified, switch to it
elif self.protocol not in [2, "2"]:
if isinstance(self._parser, _AsyncRESP2Parser):
self.set_parser(_AsyncRESP3Parser)
# update cluster exception classes
self._parser.EXCEPTION_CLASSES = parser.EXCEPTION_CLASSES
self._parser.on_connect(self)
await self.send_command("HELLO", self.protocol)
response = await self.read_response()
# if response.get(b"proto") != self.protocol and response.get(
# "proto"
# ) != self.protocol:
# raise ConnectionError("Invalid RESP version")
# if a client_name is given, set it
if self.client_name:
await self.send_command("CLIENT", "SETNAME", self.client_name)
if str_if_bytes(await self.read_response()) != "OK":
raise ConnectionError("Error setting client name")
# set the library name and version, pipeline for lower startup latency
if self.lib_name:
await self.send_command("CLIENT", "SETINFO", "LIB-NAME", self.lib_name)
if self.lib_version:
await self.send_command("CLIENT", "SETINFO", "LIB-VER", self.lib_version)
# if a database is specified, switch to it. Also pipeline this
if self.db:
await self.send_command("SELECT", self.db)
# if client caching is enabled, start tracking
if self.client_cache:
await self.send_command("CLIENT", "TRACKING", "ON")
await self.read_response()
self._parser.set_invalidation_push_handler(self._cache_invalidation_process)
# read responses from pipeline
for _ in (sent for sent in (self.lib_name, self.lib_version) if sent):
try:
await self.read_response()
except ResponseError:
pass
if self.db:
if str_if_bytes(await self.read_response()) != "OK":
raise ConnectionError("Invalid Database")
async def disconnect(self, nowait: bool = False) -> None:
"""Disconnects from the Valkey server"""
try:
async with async_timeout(self.socket_connect_timeout):
self._parser.on_disconnect()
if not self.is_connected:
return
try:
self._writer.close() # type: ignore[union-attr]
# wait for close to finish, except when handling errors and
# forcefully disconnecting.
if not nowait:
await self._writer.wait_closed() # type: ignore[union-attr]
except OSError:
pass
finally:
self._reader = None
self._writer = None
except asyncio.TimeoutError:
raise TimeoutError(
f"Timed out closing connection after {self.socket_connect_timeout}"
) from None
finally:
if self.client_cache:
self.client_cache.flush()
async def _send_ping(self):
"""Send PING, expect PONG in return"""
await self.send_command("PING", check_health=False)
if str_if_bytes(await self.read_response()) != "PONG":
raise ConnectionError("Bad response from PING health check")
async def _ping_failed(self, error):
"""Function to call when PING fails"""
await self.disconnect()
async def check_health(self):
"""Check the health of the connection with a PING/PONG"""
if (
self.health_check_interval
and asyncio.get_running_loop().time() > self.next_health_check
):
await self.retry.call_with_retry(self._send_ping, self._ping_failed)
async def _send_packed_command(self, command: Iterable[bytes]) -> None:
self._writer.writelines(command)
await self._writer.drain()
async def send_packed_command(
self, command: Union[bytes, str, Iterable[bytes]], check_health: bool = True
) -> None:
if not self.is_connected:
await self.connect()
elif check_health:
await self.check_health()
try:
if isinstance(command, str):
command = command.encode()
if isinstance(command, bytes):
command = [command]
if self.socket_timeout:
await asyncio.wait_for(
self._send_packed_command(command), self.socket_timeout
)
else:
self._writer.writelines(command)
await self._writer.drain()
except asyncio.TimeoutError:
await self.disconnect(nowait=True)
raise TimeoutError("Timeout writing to socket") from None
except OSError as e:
await self.disconnect(nowait=True)
if len(e.args) == 1:
err_no, errmsg = "UNKNOWN", e.args[0]
else:
err_no = e.args[0]
errmsg = e.args[1]
raise ConnectionError(
f"Error {err_no} while writing to socket. {errmsg}."
) from e
except BaseException:
# BaseExceptions can be raised when a socket send operation is not
# finished, e.g. due to a timeout. Ideally, a caller could then re-try
# to send un-sent data. However, the send_packed_command() API
# does not support it so there is no point in keeping the connection open.
await self.disconnect(nowait=True)
raise
async def send_command(self, *args: Any, **kwargs: Any) -> None:
"""Pack and send a command to the Valkey server"""
await self.send_packed_command(
self.pack_command(*args), check_health=kwargs.get("check_health", True)
)
async def can_read_destructive(self):
"""Poll the socket to see if there's data that can be read."""
try:
return await self._parser.can_read_destructive()
except OSError as e:
await self.disconnect(nowait=True)
host_error = self._host_error()
raise ConnectionError(f"Error while reading from {host_error}: {e.args}")
async def read_response(
self,
disable_decoding: bool = False,
timeout: Optional[float] = None,
*,
disconnect_on_error: bool = True,
push_request: Optional[bool] = False,
):
"""Read the response from a previously sent command"""
read_timeout = timeout if timeout is not None else self.socket_timeout
host_error = self._host_error()
try:
if (
read_timeout is not None
and self.protocol in ["3", 3]
and not LIBVALKEY_AVAILABLE
):
async with async_timeout(read_timeout):
response = await self._parser.read_response(
disable_decoding=disable_decoding, push_request=push_request
)
elif read_timeout is not None:
async with async_timeout(read_timeout):
response = await self._parser.read_response(
disable_decoding=disable_decoding
)
elif self.protocol in ["3", 3] and not LIBVALKEY_AVAILABLE:
response = await self._parser.read_response(
disable_decoding=disable_decoding, push_request=push_request
)
else:
response = await self._parser.read_response(
disable_decoding=disable_decoding
)
except asyncio.TimeoutError:
if timeout is not None:
# user requested timeout, return None. Operation can be retried
return None
# it was a self.socket_timeout error.
if disconnect_on_error:
await self.disconnect(nowait=True)
raise TimeoutError(f"Timeout reading from {host_error}")
except OSError as e:
if disconnect_on_error:
await self.disconnect(nowait=True)
raise ConnectionError(f"Error while reading from {host_error} : {e.args}")
except BaseException:
# Also by default close in case of BaseException. A lot of code
# relies on this behaviour when doing Command/Response pairs.
# See #1128.
if disconnect_on_error:
await self.disconnect(nowait=True)
raise
if self.health_check_interval:
next_time = asyncio.get_running_loop().time() + self.health_check_interval
self.next_health_check = next_time
if isinstance(response, ResponseError):
raise response from None
return response
def pack_command(self, *args: EncodableT) -> List[bytes]:
"""Pack a series of arguments into the Valkey protocol"""
output = []
# the client might have included 1 or more literal arguments in
# the command name, e.g., 'CONFIG GET'. The Valkey server expects these
# arguments to be sent separately, so split the first argument
# manually. These arguments should be bytestrings so that they are
# not encoded.
assert not isinstance(args[0], float)
if isinstance(args[0], str):
args = tuple(args[0].encode().split()) + args[1:]
elif b" " in args[0]:
args = tuple(args[0].split()) + args[1:]
buff = SYM_EMPTY.join((SYM_STAR, str(len(args)).encode(), SYM_CRLF))
buffer_cutoff = self._buffer_cutoff
for arg in map(self.encoder.encode, args):
# to avoid large string mallocs, chunk the command into the
# output list if we're sending large values or memoryviews
arg_length = len(arg)
if (
len(buff) > buffer_cutoff
or arg_length > buffer_cutoff
or isinstance(arg, memoryview)
):
buff = SYM_EMPTY.join(
(buff, SYM_DOLLAR, str(arg_length).encode(), SYM_CRLF)
)
output.append(buff)
output.append(arg)
buff = SYM_CRLF
else:
buff = SYM_EMPTY.join(
(
buff,
SYM_DOLLAR,
str(arg_length).encode(),
SYM_CRLF,
arg,
SYM_CRLF,
)
)
output.append(buff)
return output
def pack_commands(self, commands: Iterable[Iterable[EncodableT]]) -> List[bytes]:
"""Pack multiple commands into the Valkey protocol"""
output: List[bytes] = []
pieces: List[bytes] = []
buffer_length = 0
buffer_cutoff = self._buffer_cutoff
for cmd in commands:
for chunk in self.pack_command(*cmd):
chunklen = len(chunk)
if (
buffer_length > buffer_cutoff
or chunklen > buffer_cutoff
or isinstance(chunk, memoryview)
):
if pieces:
output.append(SYM_EMPTY.join(pieces))
buffer_length = 0
pieces = []
if chunklen > buffer_cutoff or isinstance(chunk, memoryview):
output.append(chunk)
else:
pieces.append(chunk)
buffer_length += chunklen
if pieces:
output.append(SYM_EMPTY.join(pieces))
return output
def _socket_is_empty(self):
"""Check if the socket is empty"""
return len(self._reader._buffer) == 0
def _cache_invalidation_process(
self, data: List[Union[str, Optional[List[str]]]]
) -> None:
"""
Invalidate (delete) all valkey commands associated with a specific key.
`data` is a list of strings, where the first string is the invalidation message
and the second string is the list of keys to invalidate.
(if the list of keys is None, then all keys are invalidated)
"""
if data[1] is None:
self.client_cache.flush()
else:
for key in data[1]:
self.client_cache.invalidate_key(str_if_bytes(key))
async def _get_from_local_cache(self, command: str):
"""
If the command is in the local cache, return the response
"""
if (
self.client_cache is None
or command[0] in self.cache_deny_list
or command[0] not in self.cache_allow_list
):
return None
while not self._socket_is_empty():
await self.read_response(push_request=True)
return self.client_cache.get(command)
def _add_to_local_cache(
self, command: Tuple[str], response: ResponseT, keys: List[KeysT]
):
"""
Add the command and response to the local cache if the command
is allowed to be cached
"""
if (
self.client_cache is not None
and (self.cache_deny_list == [] or command[0] not in self.cache_deny_list)
and (self.cache_allow_list == [] or command[0] in self.cache_allow_list)
):
self.client_cache.set(command, response, keys)
def flush_cache(self):
if self.client_cache:
self.client_cache.flush()
def delete_command_from_cache(self, command):
if self.client_cache:
self.client_cache.delete_command(command)
def invalidate_key_from_cache(self, key):
if self.client_cache:
self.client_cache.invalidate_key(key)
[docs]
class Connection(AbstractConnection):
"Manages TCP communication to and from a Valkey server"
def __init__(
self,
*,
host: str = "localhost",
port: Union[str, int] = 6379,
socket_keepalive: bool = False,
socket_keepalive_options: Optional[Mapping[int, Union[int, bytes]]] = None,
socket_type: int = 0,
**kwargs,
):
self.host = host
self.port = int(port)
self.socket_keepalive = socket_keepalive
self.socket_keepalive_options = socket_keepalive_options or {}
self.socket_type = socket_type
super().__init__(**kwargs)
def repr_pieces(self):
pieces = [("host", self.host), ("port", self.port), ("db", self.db)]
if self.client_name:
pieces.append(("client_name", self.client_name))
return pieces
def _connection_arguments(self) -> Mapping:
return {"host": self.host, "port": self.port}
async def _connect(self):
"""Create a TCP socket connection"""
async with async_timeout(self.socket_connect_timeout):
reader, writer = await asyncio.open_connection(
**self._connection_arguments()
)
self._reader = reader
self._writer = writer
sock = writer.transport.get_extra_info("socket")
if sock:
sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
try:
# TCP_KEEPALIVE
if self.socket_keepalive:
sock.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1)
for k, v in self.socket_keepalive_options.items():
sock.setsockopt(socket.SOL_TCP, k, v)
except (OSError, TypeError):
# `socket_keepalive_options` might contain invalid options
# causing an error. Do not leave the connection open.
writer.close()
raise
def _host_error(self) -> str:
return f"{self.host}:{self.port}"
class SSLConnection(Connection):
"""Manages SSL connections to and from the Valkey server(s).
This class extends the Connection class, adding SSL functionality, and making
use of ssl.SSLContext (https://docs.python.org/3/library/ssl.html#ssl.SSLContext)
"""
def __init__(
self,
ssl_keyfile: Optional[str] = None,
ssl_certfile: Optional[str] = None,
ssl_cert_reqs: str = "required",
ssl_ca_certs: Optional[str] = None,
ssl_ca_data: Optional[str] = None,
ssl_check_hostname: bool = False,
ssl_min_version: Optional[ssl.TLSVersion] = None,
ssl_ciphers: Optional[str] = None,
**kwargs,
):
self.ssl_context: ValkeySSLContext = ValkeySSLContext(
keyfile=ssl_keyfile,
certfile=ssl_certfile,
cert_reqs=ssl_cert_reqs,
ca_certs=ssl_ca_certs,
ca_data=ssl_ca_data,
check_hostname=ssl_check_hostname,
min_version=ssl_min_version,
ciphers=ssl_ciphers,
)
super().__init__(**kwargs)
def _connection_arguments(self) -> Mapping:
kwargs = super()._connection_arguments()
kwargs["ssl"] = self.ssl_context.get()
return kwargs
@property
def keyfile(self):
return self.ssl_context.keyfile
@property
def certfile(self):
return self.ssl_context.certfile
@property
def cert_reqs(self):
return self.ssl_context.cert_reqs
@property
def ca_certs(self):
return self.ssl_context.ca_certs
@property
def ca_data(self):
return self.ssl_context.ca_data
@property
def check_hostname(self):
return self.ssl_context.check_hostname
@property
def min_version(self):
return self.ssl_context.min_version
class ValkeySSLContext:
__slots__ = (
"keyfile",
"certfile",
"cert_reqs",
"ca_certs",
"ca_data",
"context",
"check_hostname",
"min_version",
"ciphers",
)
def __init__(
self,
keyfile: Optional[str] = None,
certfile: Optional[str] = None,
cert_reqs: Optional[str] = None,
ca_certs: Optional[str] = None,
ca_data: Optional[str] = None,
check_hostname: bool = False,
min_version: Optional[ssl.TLSVersion] = None,
ciphers: Optional[str] = None,
):
self.keyfile = keyfile
self.certfile = certfile
if cert_reqs is None:
self.cert_reqs = ssl.CERT_NONE
elif isinstance(cert_reqs, str):
CERT_REQS = {
"none": ssl.CERT_NONE,
"optional": ssl.CERT_OPTIONAL,
"required": ssl.CERT_REQUIRED,
}
if cert_reqs not in CERT_REQS:
raise ValkeyError(
f"Invalid SSL Certificate Requirements Flag: {cert_reqs}"
)
self.cert_reqs = CERT_REQS[cert_reqs]
self.ca_certs = ca_certs
self.ca_data = ca_data
self.check_hostname = check_hostname
self.min_version = min_version
self.ciphers = ciphers
self.context: Optional[ssl.SSLContext] = None
def get(self) -> ssl.SSLContext:
if not self.context:
context = ssl.create_default_context()
context.check_hostname = self.check_hostname
context.verify_mode = self.cert_reqs
if self.certfile and self.keyfile:
context.load_cert_chain(certfile=self.certfile, keyfile=self.keyfile)
if self.ca_certs or self.ca_data:
context.load_verify_locations(cafile=self.ca_certs, cadata=self.ca_data)
if self.min_version is not None:
context.minimum_version = self.min_version
if self.ciphers is not None:
context.set_ciphers(self.ciphers)
self.context = context
return self.context
class UnixDomainSocketConnection(AbstractConnection):
"Manages UDS communication to and from a Valkey server"
def __init__(self, *, path: str = "", **kwargs):
self.path = path
super().__init__(**kwargs)
def repr_pieces(self) -> Iterable[Tuple[str, Union[str, int]]]:
pieces = [("path", self.path), ("db", self.db)]
if self.client_name:
pieces.append(("client_name", self.client_name))
return pieces
async def _connect(self):
async with async_timeout(self.socket_connect_timeout):
reader, writer = await asyncio.open_unix_connection(path=self.path)
self._reader = reader
self._writer = writer
await self.on_connect()
def _host_error(self) -> str:
return self.path
class ConnectKwargs(TypedDict, total=False):
username: str
password: str
connection_class: Type[AbstractConnection]
host: str
port: int
db: int
path: str
_CP = TypeVar("_CP", bound="ConnectionPool")
[docs]
class ConnectionPool:
"""
Create a connection pool. ``If max_connections`` is set, then this
object raises :py:class:`~valkey.ConnectionError` when the pool's
limit is reached.
By default, TCP connections are created unless ``connection_class``
is specified. Use :py:class:`~valkey.UnixDomainSocketConnection` for
unix sockets.
Any additional keyword arguments are passed to the constructor of
``connection_class``.
"""
[docs]
@classmethod
def from_url(cls: Type[_CP], url: str, **kwargs) -> _CP:
"""
Return a connection pool configured from the given URL.
For example::
valkey://[[username]:[password]]@localhost:6379/0
valkeys://[[username]:[password]]@localhost:6379/0
unix://[username@]/path/to/socket.sock?db=0[&password=password]
Three URL schemes are supported:
- `valkey://` creates a TCP socket connection.
- `valkeys://` creates a SSL wrapped TCP socket connection.
- ``unix://``: creates a Unix Domain Socket connection.
The username, password, hostname, path and all querystring values
are passed through urllib.parse.unquote in order to replace any
percent-encoded values with their corresponding characters.
There are several ways to specify a database number. The first value
found will be used:
1. A ``db`` querystring option, e.g. valkey://localhost?db=0
2. If using the valkey:// or valkeys:// schemes, the path argument
of the url, e.g. valkey://localhost/0
3. A ``db`` keyword argument to this function.
If none of these options are specified, the default db=0 is used.
All querystring options are cast to their appropriate Python types.
Boolean arguments can be specified with string values "True"/"False"
or "Yes"/"No". Values that cannot be properly cast cause a
``ValueError`` to be raised. Once parsed, the querystring arguments
and keyword arguments are passed to the ``ConnectionPool``'s
class initializer. In the case of conflicting arguments, querystring
arguments always win.
"""
url_options = parse_url(url)
kwargs.update(url_options)
return cls(**kwargs)
def __init__(
self,
connection_class: Type[AbstractConnection] = Connection,
max_connections: Optional[int] = None,
**connection_kwargs,
):
max_connections = max_connections or 2**31
if not isinstance(max_connections, int) or max_connections < 0:
raise ValueError('"max_connections" must be a positive integer')
self.connection_class = connection_class
self.connection_kwargs = connection_kwargs
self.max_connections = max_connections
self._available_connections: List[AbstractConnection] = []
self._in_use_connections: Set[AbstractConnection] = set()
self.encoder_class = self.connection_kwargs.get("encoder_class", Encoder)
def __repr__(self):
return (
f"<{self.__class__.__module__}.{self.__class__.__name__}"
f"({self.connection_class(**self.connection_kwargs)!r})>"
)
def reset(self):
self._available_connections = []
self._in_use_connections = weakref.WeakSet()
[docs]
def can_get_connection(self) -> bool:
"""Return True if a connection can be retrieved from the pool."""
return (
self._available_connections
or len(self._in_use_connections) < self.max_connections
)
[docs]
async def get_connection(self, command_name, *keys, **options):
"""Get a connected connection from the pool"""
connection = self.get_available_connection()
try:
await self.ensure_connection(connection)
except BaseException:
await self.release(connection)
raise
return connection
[docs]
def get_available_connection(self):
"""Get a connection from the pool, without making sure it is connected"""
try:
connection = self._available_connections.pop()
except IndexError:
if len(self._in_use_connections) >= self.max_connections:
raise ConnectionError("Too many connections") from None
connection = self.make_connection()
self._in_use_connections.add(connection)
return connection
[docs]
def get_encoder(self):
"""Return an encoder based on encoding settings"""
kwargs = self.connection_kwargs
return self.encoder_class(
encoding=kwargs.get("encoding", "utf-8"),
encoding_errors=kwargs.get("encoding_errors", "strict"),
decode_responses=kwargs.get("decode_responses", False),
)
[docs]
def make_connection(self):
"""Create a new connection. Can be overridden by child classes."""
return self.connection_class(**self.connection_kwargs)
[docs]
async def ensure_connection(self, connection: AbstractConnection):
"""Ensure that the connection object is connected and valid"""
await connection.connect()
# if client caching is not enabled connections that the pool
# provides should be ready to send a command.
# if not, the connection was either returned to the
# pool before all data has been read or the socket has been
# closed. either way, reconnect and verify everything is good.
# (if caching enabled the connection will not always be ready
# to send a command because it may contain invalidation messages)
try:
if (
await connection.can_read_destructive()
and connection.client_cache is None
):
raise ConnectionError("Connection has data") from None
except (ConnectionError, OSError):
await connection.disconnect()
await connection.connect()
if await connection.can_read_destructive():
raise ConnectionError("Connection not ready") from None
[docs]
async def release(self, connection: AbstractConnection):
"""Releases the connection back to the pool"""
# Connections should always be returned to the correct pool,
# not doing so is an error that will cause an exception here.
self._in_use_connections.remove(connection)
self._available_connections.append(connection)
[docs]
async def disconnect(self, inuse_connections: bool = True):
"""
Disconnects connections in the pool
If ``inuse_connections`` is True, disconnect connections that are
current in use, potentially by other tasks. Otherwise only disconnect
connections that are idle in the pool.
"""
if inuse_connections:
connections: Iterable[AbstractConnection] = chain(
self._available_connections, self._in_use_connections
)
else:
connections = self._available_connections
resp = await asyncio.gather(
*(connection.disconnect() for connection in connections),
return_exceptions=True,
)
exc = next((r for r in resp if isinstance(r, BaseException)), None)
if exc:
raise exc
[docs]
async def aclose(self) -> None:
"""Close the pool, disconnecting all connections"""
await self.disconnect()
def set_retry(self, retry: "Retry") -> None:
for conn in self._available_connections:
conn.retry = retry
for conn in self._in_use_connections:
conn.retry = retry
def flush_cache(self):
connections = chain(self._available_connections, self._in_use_connections)
for connection in connections:
connection.flush_cache()
def delete_command_from_cache(self, command: str):
connections = chain(self._available_connections, self._in_use_connections)
for connection in connections:
connection.delete_command_from_cache(command)
def invalidate_key_from_cache(self, key: str):
connections = chain(self._available_connections, self._in_use_connections)
for connection in connections:
connection.invalidate_key_from_cache(key)
class BlockingConnectionPool(ConnectionPool):
"""
A blocking connection pool::
>>> from valkey.asyncio import Valkey, BlockingConnectionPool
>>> client = Valkey.from_pool(BlockingConnectionPool())
It performs the same function as the default
:py:class:`~valkey.asyncio.ConnectionPool` implementation, in that,
it maintains a pool of reusable connections that can be shared by
multiple async valkey clients.
The difference is that, in the event that a client tries to get a
connection from the pool when all of connections are in use, rather than
raising a :py:class:`~valkey.ConnectionError` (as the default
:py:class:`~valkey.asyncio.ConnectionPool` implementation does), it
blocks the current `Task` for a specified number of seconds until
a connection becomes available.
Use ``max_connections`` to increase / decrease the pool size::
>>> pool = BlockingConnectionPool(max_connections=10)
Use ``timeout`` to tell it either how many seconds to wait for a connection
to become available, or to block forever:
>>> # Block forever.
>>> pool = BlockingConnectionPool(timeout=None)
>>> # Raise a ``ConnectionError`` after five seconds if a connection is
>>> # not available.
>>> pool = BlockingConnectionPool(timeout=5)
"""
def __init__(
self,
max_connections: int = 50,
timeout: Optional[int] = 20,
connection_class: Type[AbstractConnection] = Connection,
queue_class: Type[asyncio.Queue] = asyncio.LifoQueue, # deprecated
**connection_kwargs,
):
super().__init__(
connection_class=connection_class,
max_connections=max_connections,
**connection_kwargs,
)
self._condition = asyncio.Condition()
self.timeout = timeout
async def get_connection(self, command_name, *keys, **options):
"""Gets a connection from the pool, blocking until one is available"""
try:
async with self._condition:
async with async_timeout(self.timeout):
await self._condition.wait_for(self.can_get_connection)
connection = super().get_available_connection()
except asyncio.TimeoutError as err:
raise ConnectionError("No connection available.") from err
# We now perform the connection check outside of the lock.
try:
await self.ensure_connection(connection)
return connection
except BaseException:
await self.release(connection)
raise
async def release(self, connection: AbstractConnection):
"""Releases the connection back to the pool."""
async with self._condition:
await super().release(connection)
self._condition.notify()