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summit/backend/venv/lib/python3.12/site-packages/redis/connection.py

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import copy
import os
import socket
import sys
import threading
import time
import weakref
from abc import ABC, abstractmethod
from itertools import chain
from queue import Empty, Full, LifoQueue
from typing import (
Any,
Callable,
Dict,
Iterable,
List,
Literal,
Optional,
Type,
TypeVar,
Union,
)
from urllib.parse import parse_qs, unquote, urlparse
from redis.cache import (
CacheEntry,
CacheEntryStatus,
CacheFactory,
CacheFactoryInterface,
CacheInterface,
CacheKey,
)
from ._parsers import Encoder, _HiredisParser, _RESP2Parser, _RESP3Parser
from .auth.token import TokenInterface
from .backoff import NoBackoff
from .credentials import CredentialProvider, UsernamePasswordCredentialProvider
from .event import AfterConnectionReleasedEvent, EventDispatcher
from .exceptions import (
AuthenticationError,
AuthenticationWrongNumberOfArgsError,
ChildDeadlockedError,
ConnectionError,
DataError,
MaxConnectionsError,
RedisError,
ResponseError,
TimeoutError,
)
from .maint_notifications import (
MaintenanceState,
MaintNotificationsConfig,
MaintNotificationsConnectionHandler,
MaintNotificationsPoolHandler,
)
from .retry import Retry
from .utils import (
CRYPTOGRAPHY_AVAILABLE,
HIREDIS_AVAILABLE,
SSL_AVAILABLE,
compare_versions,
deprecated_args,
ensure_string,
format_error_message,
get_lib_version,
str_if_bytes,
)
if SSL_AVAILABLE:
import ssl
from ssl import VerifyFlags
else:
ssl = None
VerifyFlags = None
if HIREDIS_AVAILABLE:
import hiredis
SYM_STAR = b"*"
SYM_DOLLAR = b"$"
SYM_CRLF = b"\r\n"
SYM_EMPTY = b""
DEFAULT_RESP_VERSION = 2
SENTINEL = object()
DefaultParser: Type[Union[_RESP2Parser, _RESP3Parser, _HiredisParser]]
if HIREDIS_AVAILABLE:
DefaultParser = _HiredisParser
else:
DefaultParser = _RESP2Parser
class HiredisRespSerializer:
def pack(self, *args: List):
"""Pack a series of arguments into the Redis protocol"""
output = []
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:]
try:
output.append(hiredis.pack_command(args))
except TypeError:
_, value, traceback = sys.exc_info()
raise DataError(value).with_traceback(traceback)
return output
class PythonRespSerializer:
def __init__(self, buffer_cutoff, encode) -> None:
self._buffer_cutoff = buffer_cutoff
self.encode = encode
def pack(self, *args):
"""Pack a series of arguments into the Redis protocol"""
output = []
# the client might have included 1 or more literal arguments in
# the command name, e.g., 'CONFIG GET'. The Redis 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.
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.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
class ConnectionInterface:
@abstractmethod
def repr_pieces(self):
pass
@abstractmethod
def register_connect_callback(self, callback):
pass
@abstractmethod
def deregister_connect_callback(self, callback):
pass
@abstractmethod
def set_parser(self, parser_class):
pass
@abstractmethod
def get_protocol(self):
pass
@abstractmethod
def connect(self):
pass
@abstractmethod
def on_connect(self):
pass
@abstractmethod
def disconnect(self, *args):
pass
@abstractmethod
def check_health(self):
pass
@abstractmethod
def send_packed_command(self, command, check_health=True):
pass
@abstractmethod
def send_command(self, *args, **kwargs):
pass
@abstractmethod
def can_read(self, timeout=0):
pass
@abstractmethod
def read_response(
self,
disable_decoding=False,
*,
disconnect_on_error=True,
push_request=False,
):
pass
@abstractmethod
def pack_command(self, *args):
pass
@abstractmethod
def pack_commands(self, commands):
pass
@property
@abstractmethod
def handshake_metadata(self) -> Union[Dict[bytes, bytes], Dict[str, str]]:
pass
@abstractmethod
def set_re_auth_token(self, token: TokenInterface):
pass
@abstractmethod
def re_auth(self):
pass
@abstractmethod
def mark_for_reconnect(self):
"""
Mark the connection to be reconnected on the next command.
This is useful when a connection is moved to a different node.
"""
pass
@abstractmethod
def should_reconnect(self):
"""
Returns True if the connection should be reconnected.
"""
pass
@abstractmethod
def reset_should_reconnect(self):
"""
Reset the internal flag to False.
"""
pass
class MaintNotificationsAbstractConnection:
"""
Abstract class for handling maintenance notifications logic.
This class is expected to be used as base class together with ConnectionInterface.
This class is intended to be used with multiple inheritance!
All logic related to maintenance notifications is encapsulated in this class.
"""
def __init__(
self,
maint_notifications_config: Optional[MaintNotificationsConfig],
maint_notifications_pool_handler: Optional[
MaintNotificationsPoolHandler
] = None,
maintenance_state: "MaintenanceState" = MaintenanceState.NONE,
maintenance_notification_hash: Optional[int] = None,
orig_host_address: Optional[str] = None,
orig_socket_timeout: Optional[float] = None,
orig_socket_connect_timeout: Optional[float] = None,
parser: Optional[Union[_HiredisParser, _RESP3Parser]] = None,
):
"""
Initialize the maintenance notifications for the connection.
Args:
maint_notifications_config (MaintNotificationsConfig): The configuration for maintenance notifications.
maint_notifications_pool_handler (Optional[MaintNotificationsPoolHandler]): The pool handler for maintenance notifications.
maintenance_state (MaintenanceState): The current maintenance state of the connection.
maintenance_notification_hash (Optional[int]): The current maintenance notification hash of the connection.
orig_host_address (Optional[str]): The original host address of the connection.
orig_socket_timeout (Optional[float]): The original socket timeout of the connection.
orig_socket_connect_timeout (Optional[float]): The original socket connect timeout of the connection.
parser (Optional[Union[_HiredisParser, _RESP3Parser]]): The parser to use for maintenance notifications.
If not provided, the parser from the connection is used.
This is useful when the parser is created after this object.
"""
self.maint_notifications_config = maint_notifications_config
self.maintenance_state = maintenance_state
self.maintenance_notification_hash = maintenance_notification_hash
self._configure_maintenance_notifications(
maint_notifications_pool_handler,
orig_host_address,
orig_socket_timeout,
orig_socket_connect_timeout,
parser,
)
@abstractmethod
def _get_parser(self) -> Union[_HiredisParser, _RESP3Parser]:
pass
@abstractmethod
def _get_socket(self) -> Optional[socket.socket]:
pass
@abstractmethod
def get_protocol(self) -> Union[int, str]:
"""
Returns:
The RESP protocol version, or ``None`` if the protocol is not specified,
in which case the server default will be used.
"""
pass
@property
@abstractmethod
def host(self) -> str:
pass
@host.setter
@abstractmethod
def host(self, value: str):
pass
@property
@abstractmethod
def socket_timeout(self) -> Optional[Union[float, int]]:
pass
@socket_timeout.setter
@abstractmethod
def socket_timeout(self, value: Optional[Union[float, int]]):
pass
@property
@abstractmethod
def socket_connect_timeout(self) -> Optional[Union[float, int]]:
pass
@socket_connect_timeout.setter
@abstractmethod
def socket_connect_timeout(self, value: Optional[Union[float, int]]):
pass
@abstractmethod
def send_command(self, *args, **kwargs):
pass
@abstractmethod
def read_response(
self,
disable_decoding=False,
*,
disconnect_on_error=True,
push_request=False,
):
pass
@abstractmethod
def disconnect(self, *args):
pass
def _configure_maintenance_notifications(
self,
maint_notifications_pool_handler: Optional[
MaintNotificationsPoolHandler
] = None,
orig_host_address=None,
orig_socket_timeout=None,
orig_socket_connect_timeout=None,
parser: Optional[Union[_HiredisParser, _RESP3Parser]] = None,
):
"""
Enable maintenance notifications by setting up
handlers and storing original connection parameters.
Should be used ONLY with parsers that support push notifications.
"""
if (
not self.maint_notifications_config
or not self.maint_notifications_config.enabled
):
self._maint_notifications_pool_handler = None
self._maint_notifications_connection_handler = None
return
if not parser:
raise RedisError(
"To configure maintenance notifications, a parser must be provided!"
)
if not isinstance(parser, _HiredisParser) and not isinstance(
parser, _RESP3Parser
):
raise RedisError(
"Maintenance notifications are only supported with hiredis and RESP3 parsers!"
)
if maint_notifications_pool_handler:
# Extract a reference to a new pool handler that copies all properties
# of the original one and has a different connection reference
# This is needed because when we attach the handler to the parser
# we need to make sure that the handler has a reference to the
# connection that the parser is attached to.
self._maint_notifications_pool_handler = (
maint_notifications_pool_handler.get_handler_for_connection()
)
self._maint_notifications_pool_handler.set_connection(self)
else:
self._maint_notifications_pool_handler = None
self._maint_notifications_connection_handler = (
MaintNotificationsConnectionHandler(self, self.maint_notifications_config)
)
# Set up pool handler if available
if self._maint_notifications_pool_handler:
parser.set_node_moving_push_handler(
self._maint_notifications_pool_handler.handle_notification
)
# Set up connection handler
parser.set_maintenance_push_handler(
self._maint_notifications_connection_handler.handle_notification
)
# Store original connection parameters
self.orig_host_address = orig_host_address if orig_host_address else self.host
self.orig_socket_timeout = (
orig_socket_timeout if orig_socket_timeout else self.socket_timeout
)
self.orig_socket_connect_timeout = (
orig_socket_connect_timeout
if orig_socket_connect_timeout
else self.socket_connect_timeout
)
def set_maint_notifications_pool_handler_for_connection(
self, maint_notifications_pool_handler: MaintNotificationsPoolHandler
):
# Deep copy the pool handler to avoid sharing the same pool handler
# between multiple connections, because otherwise each connection will override
# the connection reference and the pool handler will only hold a reference
# to the last connection that was set.
maint_notifications_pool_handler_copy = (
maint_notifications_pool_handler.get_handler_for_connection()
)
maint_notifications_pool_handler_copy.set_connection(self)
self._get_parser().set_node_moving_push_handler(
maint_notifications_pool_handler_copy.handle_notification
)
self._maint_notifications_pool_handler = maint_notifications_pool_handler_copy
# Update maintenance notification connection handler if it doesn't exist
if not self._maint_notifications_connection_handler:
self._maint_notifications_connection_handler = (
MaintNotificationsConnectionHandler(
self, maint_notifications_pool_handler.config
)
)
self._get_parser().set_maintenance_push_handler(
self._maint_notifications_connection_handler.handle_notification
)
else:
self._maint_notifications_connection_handler.config = (
maint_notifications_pool_handler.config
)
def activate_maint_notifications_handling_if_enabled(self, check_health=True):
# Send maintenance notifications handshake if RESP3 is active
# and maintenance notifications are enabled
# and we have a host to determine the endpoint type from
# When the maint_notifications_config enabled mode is "auto",
# we just log a warning if the handshake fails
# When the mode is enabled=True, we raise an exception in case of failure
if (
self.get_protocol() not in [2, "2"]
and self.maint_notifications_config
and self.maint_notifications_config.enabled
and self._maint_notifications_connection_handler
and hasattr(self, "host")
):
self._enable_maintenance_notifications(
maint_notifications_config=self.maint_notifications_config,
check_health=check_health,
)
def _enable_maintenance_notifications(
self, maint_notifications_config: MaintNotificationsConfig, check_health=True
):
try:
host = getattr(self, "host", None)
if host is None:
raise ValueError(
"Cannot enable maintenance notifications for connection"
" object that doesn't have a host attribute."
)
else:
endpoint_type = maint_notifications_config.get_endpoint_type(host, self)
self.send_command(
"CLIENT",
"MAINT_NOTIFICATIONS",
"ON",
"moving-endpoint-type",
endpoint_type.value,
check_health=check_health,
)
response = self.read_response()
if not response or str_if_bytes(response) != "OK":
raise ResponseError(
"The server doesn't support maintenance notifications"
)
except Exception as e:
if (
isinstance(e, ResponseError)
and maint_notifications_config.enabled == "auto"
):
# Log warning but don't fail the connection
import logging
logger = logging.getLogger(__name__)
logger.debug(f"Failed to enable maintenance notifications: {e}")
else:
raise
def get_resolved_ip(self) -> Optional[str]:
"""
Extract the resolved IP address from an
established connection or resolve it from the host.
First tries to get the actual IP from the socket (most accurate),
then falls back to DNS resolution if needed.
Args:
connection: The connection object to extract the IP from
Returns:
str: The resolved IP address, or None if it cannot be determined
"""
# Method 1: Try to get the actual IP from the established socket connection
# This is most accurate as it shows the exact IP being used
try:
conn_socket = self._get_socket()
if conn_socket is not None:
peer_addr = conn_socket.getpeername()
if peer_addr and len(peer_addr) >= 1:
# For TCP sockets, peer_addr is typically (host, port) tuple
# Return just the host part
return peer_addr[0]
except (AttributeError, OSError):
# Socket might not be connected or getpeername() might fail
pass
# Method 2: Fallback to DNS resolution of the host
# This is less accurate but works when socket is not available
try:
host = getattr(self, "host", "localhost")
port = getattr(self, "port", 6379)
if host:
# Use getaddrinfo to resolve the hostname to IP
# This mimics what the connection would do during _connect()
addr_info = socket.getaddrinfo(
host, port, socket.AF_UNSPEC, socket.SOCK_STREAM
)
if addr_info:
# Return the IP from the first result
# addr_info[0] is (family, socktype, proto, canonname, sockaddr)
# sockaddr[0] is the IP address
return str(addr_info[0][4][0])
except (AttributeError, OSError, socket.gaierror):
# DNS resolution might fail
pass
return None
@property
def maintenance_state(self) -> MaintenanceState:
return self._maintenance_state
@maintenance_state.setter
def maintenance_state(self, state: "MaintenanceState"):
self._maintenance_state = state
def getpeername(self):
"""
Returns the peer name of the connection.
"""
conn_socket = self._get_socket()
if conn_socket:
return conn_socket.getpeername()[0]
return None
def update_current_socket_timeout(self, relaxed_timeout: Optional[float] = None):
conn_socket = self._get_socket()
if conn_socket:
timeout = relaxed_timeout if relaxed_timeout != -1 else self.socket_timeout
conn_socket.settimeout(timeout)
self.update_parser_timeout(timeout)
def update_parser_timeout(self, timeout: Optional[float] = None):
parser = self._get_parser()
if parser and parser._buffer:
if isinstance(parser, _RESP3Parser) and timeout:
parser._buffer.socket_timeout = timeout
elif isinstance(parser, _HiredisParser):
parser._socket_timeout = timeout
def set_tmp_settings(
self,
tmp_host_address: Optional[Union[str, object]] = SENTINEL,
tmp_relaxed_timeout: Optional[float] = None,
):
"""
The value of SENTINEL is used to indicate that the property should not be updated.
"""
if tmp_host_address and tmp_host_address != SENTINEL:
self.host = str(tmp_host_address)
if tmp_relaxed_timeout != -1:
self.socket_timeout = tmp_relaxed_timeout
self.socket_connect_timeout = tmp_relaxed_timeout
def reset_tmp_settings(
self,
reset_host_address: bool = False,
reset_relaxed_timeout: bool = False,
):
if reset_host_address:
self.host = self.orig_host_address
if reset_relaxed_timeout:
self.socket_timeout = self.orig_socket_timeout
self.socket_connect_timeout = self.orig_socket_connect_timeout
class AbstractConnection(MaintNotificationsAbstractConnection, ConnectionInterface):
"Manages communication to and from a Redis server"
def __init__(
self,
db: int = 0,
password: Optional[str] = None,
socket_timeout: Optional[float] = None,
socket_connect_timeout: Optional[float] = None,
retry_on_timeout: bool = False,
retry_on_error: Union[Iterable[Type[Exception]], object] = SENTINEL,
encoding: str = "utf-8",
encoding_errors: str = "strict",
decode_responses: bool = False,
parser_class=DefaultParser,
socket_read_size: int = 65536,
health_check_interval: int = 0,
client_name: Optional[str] = None,
lib_name: Optional[str] = "redis-py",
lib_version: Optional[str] = get_lib_version(),
username: Optional[str] = None,
retry: Union[Any, None] = None,
redis_connect_func: Optional[Callable[[], None]] = None,
credential_provider: Optional[CredentialProvider] = None,
protocol: Optional[int] = 2,
command_packer: Optional[Callable[[], None]] = None,
event_dispatcher: Optional[EventDispatcher] = None,
maint_notifications_config: Optional[MaintNotificationsConfig] = None,
maint_notifications_pool_handler: Optional[
MaintNotificationsPoolHandler
] = None,
maintenance_state: "MaintenanceState" = MaintenanceState.NONE,
maintenance_notification_hash: Optional[int] = None,
orig_host_address: Optional[str] = None,
orig_socket_timeout: Optional[float] = None,
orig_socket_connect_timeout: Optional[float] = None,
):
"""
Initialize a new Connection.
To specify a retry policy for specific errors, first set
`retry_on_error` to a list of the error/s to retry on, then set
`retry` to a valid `Retry` object.
To retry on TimeoutError, `retry_on_timeout` can also be set to `True`.
"""
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'"
)
if event_dispatcher is None:
self._event_dispatcher = EventDispatcher()
else:
self._event_dispatcher = event_dispatcher
self.pid = os.getpid()
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_errors_list = []
else:
retry_on_errors_list = list(retry_on_error)
if retry_on_timeout:
# Add TimeoutError to the errors list to retry on
retry_on_errors_list.append(TimeoutError)
self.retry_on_error = retry_on_errors_list
if retry or self.retry_on_error:
if retry is None:
self.retry = Retry(NoBackoff(), 1)
else:
# deep-copy the Retry object as it is mutable
self.retry = copy.deepcopy(retry)
if self.retry_on_error:
# Update the retry's supported errors with the specified errors
self.retry.update_supported_errors(self.retry_on_error)
else:
self.retry = Retry(NoBackoff(), 0)
self.health_check_interval = health_check_interval
self.next_health_check = 0
self.redis_connect_func = redis_connect_func
self.encoder = Encoder(encoding, encoding_errors, decode_responses)
self.handshake_metadata = None
self._sock = None
self._socket_read_size = socket_read_size
self._connect_callbacks = []
self._buffer_cutoff = 6000
self._re_auth_token: Optional[TokenInterface] = None
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")
# p = DEFAULT_RESP_VERSION
self.protocol = p
if self.protocol == 3 and parser_class == _RESP2Parser:
# If the protocol is 3 but the parser is RESP2, change it to RESP3
# This is needed because the parser might be set before the protocol
# or might be provided as a kwarg to the constructor
# We need to react on discrepancy only for RESP2 and RESP3
# as hiredis supports both
parser_class = _RESP3Parser
self.set_parser(parser_class)
self._command_packer = self._construct_command_packer(command_packer)
self._should_reconnect = False
# Set up maintenance notifications
MaintNotificationsAbstractConnection.__init__(
self,
maint_notifications_config,
maint_notifications_pool_handler,
maintenance_state,
maintenance_notification_hash,
orig_host_address,
orig_socket_timeout,
orig_socket_connect_timeout,
self._parser,
)
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
def __del__(self):
try:
self.disconnect()
except Exception:
pass
def _construct_command_packer(self, packer):
if packer is not None:
return packer
elif HIREDIS_AVAILABLE:
return HiredisRespSerializer()
else:
return PythonRespSerializer(self._buffer_cutoff, self.encoder.encode)
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):
"""
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)
def _get_parser(self) -> Union[_HiredisParser, _RESP3Parser, _RESP2Parser]:
return self._parser
def connect(self):
"Connects to the Redis server if not already connected"
self.connect_check_health(check_health=True)
def connect_check_health(
self, check_health: bool = True, retry_socket_connect: bool = True
):
if self._sock:
return
try:
if retry_socket_connect:
sock = self.retry.call_with_retry(
lambda: self._connect(), lambda error: self.disconnect(error)
)
else:
sock = self._connect()
except socket.timeout:
raise TimeoutError("Timeout connecting to server")
except OSError as e:
raise ConnectionError(self._error_message(e))
self._sock = sock
try:
if self.redis_connect_func is None:
# Use the default on_connect function
self.on_connect_check_health(check_health=check_health)
else:
# Use the passed function redis_connect_func
self.redis_connect_func(self)
except RedisError:
# clean up after any error in on_connect
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()
if callback:
callback(self)
@abstractmethod
def _connect(self):
pass
@abstractmethod
def _host_error(self):
pass
def _error_message(self, exception):
return format_error_message(self._host_error(), exception)
def on_connect(self):
self.on_connect_check_health(check_health=True)
def on_connect_check_health(self, check_health: bool = True):
"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, _RESP2Parser):
self.set_parser(_RESP3Parser)
# 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]]
# avoid checking health here -- PING will fail if we try
# to check the health prior to the AUTH
self.send_command(
"HELLO", self.protocol, "AUTH", *auth_args, check_health=False
)
self.handshake_metadata = self.read_response()
# if response.get(b"proto") != self.protocol and response.get(
# "proto"
# ) != self.protocol:
# raise ConnectionError("Invalid RESP version")
elif auth_args:
# avoid checking health here -- PING will fail if we try
# to check the health prior to the AUTH
self.send_command("AUTH", *auth_args, check_health=False)
try:
auth_response = self.read_response()
except AuthenticationWrongNumberOfArgsError:
# a username and password were specified but the Redis
# 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
self.send_command("AUTH", auth_args[-1], check_health=False)
auth_response = 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, _RESP2Parser):
self.set_parser(_RESP3Parser)
# update cluster exception classes
self._parser.EXCEPTION_CLASSES = parser.EXCEPTION_CLASSES
self._parser.on_connect(self)
self.send_command("HELLO", self.protocol, check_health=check_health)
self.handshake_metadata = self.read_response()
if (
self.handshake_metadata.get(b"proto") != self.protocol
and self.handshake_metadata.get("proto") != self.protocol
):
raise ConnectionError("Invalid RESP version")
# Activate maintenance notifications for this connection
# if enabled in the configuration
# This is a no-op if maintenance notifications are not enabled
self.activate_maint_notifications_handling_if_enabled(check_health=check_health)
# if a client_name is given, set it
if self.client_name:
self.send_command(
"CLIENT",
"SETNAME",
self.client_name,
check_health=check_health,
)
if str_if_bytes(self.read_response()) != "OK":
raise ConnectionError("Error setting client name")
try:
# set the library name and version
if self.lib_name:
self.send_command(
"CLIENT",
"SETINFO",
"LIB-NAME",
self.lib_name,
check_health=check_health,
)
self.read_response()
except ResponseError:
pass
try:
if self.lib_version:
self.send_command(
"CLIENT",
"SETINFO",
"LIB-VER",
self.lib_version,
check_health=check_health,
)
self.read_response()
except ResponseError:
pass
# if a database is specified, switch to it
if self.db:
self.send_command("SELECT", self.db, check_health=check_health)
if str_if_bytes(self.read_response()) != "OK":
raise ConnectionError("Invalid Database")
def disconnect(self, *args):
"Disconnects from the Redis server"
self._parser.on_disconnect()
conn_sock = self._sock
self._sock = None
# reset the reconnect flag
self.reset_should_reconnect()
if conn_sock is None:
return
if os.getpid() == self.pid:
try:
conn_sock.shutdown(socket.SHUT_RDWR)
except (OSError, TypeError):
pass
try:
conn_sock.close()
except OSError:
pass
def mark_for_reconnect(self):
self._should_reconnect = True
def should_reconnect(self):
return self._should_reconnect
def reset_should_reconnect(self):
self._should_reconnect = False
def _send_ping(self):
"""Send PING, expect PONG in return"""
self.send_command("PING", check_health=False)
if str_if_bytes(self.read_response()) != "PONG":
raise ConnectionError("Bad response from PING health check")
def _ping_failed(self, error):
"""Function to call when PING fails"""
self.disconnect()
def check_health(self):
"""Check the health of the connection with a PING/PONG"""
if self.health_check_interval and time.monotonic() > self.next_health_check:
self.retry.call_with_retry(self._send_ping, self._ping_failed)
def send_packed_command(self, command, check_health=True):
"""Send an already packed command to the Redis server"""
if not self._sock:
self.connect_check_health(check_health=False)
# guard against health check recursion
if check_health:
self.check_health()
try:
if isinstance(command, str):
command = [command]
for item in command:
self._sock.sendall(item)
except socket.timeout:
self.disconnect()
raise TimeoutError("Timeout writing to socket")
except OSError as e:
self.disconnect()
if len(e.args) == 1:
errno, errmsg = "UNKNOWN", e.args[0]
else:
errno = e.args[0]
errmsg = e.args[1]
raise ConnectionError(f"Error {errno} while writing to socket. {errmsg}.")
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.
self.disconnect()
raise
def send_command(self, *args, **kwargs):
"""Pack and send a command to the Redis server"""
self.send_packed_command(
self._command_packer.pack(*args),
check_health=kwargs.get("check_health", True),
)
def can_read(self, timeout=0):
"""Poll the socket to see if there's data that can be read."""
sock = self._sock
if not sock:
self.connect()
host_error = self._host_error()
try:
return self._parser.can_read(timeout)
except OSError as e:
self.disconnect()
raise ConnectionError(f"Error while reading from {host_error}: {e.args}")
def read_response(
self,
disable_decoding=False,
*,
disconnect_on_error=True,
push_request=False,
):
"""Read the response from a previously sent command"""
host_error = self._host_error()
try:
if self.protocol in ["3", 3]:
response = self._parser.read_response(
disable_decoding=disable_decoding, push_request=push_request
)
else:
response = self._parser.read_response(disable_decoding=disable_decoding)
except socket.timeout:
if disconnect_on_error:
self.disconnect()
raise TimeoutError(f"Timeout reading from {host_error}")
except OSError as e:
if disconnect_on_error:
self.disconnect()
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:
self.disconnect()
raise
if self.health_check_interval:
self.next_health_check = time.monotonic() + self.health_check_interval
if isinstance(response, ResponseError):
try:
raise response
finally:
del response # avoid creating ref cycles
return response
def pack_command(self, *args):
"""Pack a series of arguments into the Redis protocol"""
return self._command_packer.pack(*args)
def pack_commands(self, commands):
"""Pack multiple commands into the Redis protocol"""
output = []
pieces = []
buffer_length = 0
buffer_cutoff = self._buffer_cutoff
for cmd in commands:
for chunk in self._command_packer.pack(*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 get_protocol(self) -> Union[int, str]:
return self.protocol
@property
def handshake_metadata(self) -> Union[Dict[bytes, bytes], Dict[str, str]]:
return self._handshake_metadata
@handshake_metadata.setter
def handshake_metadata(self, value: Union[Dict[bytes, bytes], Dict[str, str]]):
self._handshake_metadata = value
def set_re_auth_token(self, token: TokenInterface):
self._re_auth_token = token
def re_auth(self):
if self._re_auth_token is not None:
self.send_command(
"AUTH",
self._re_auth_token.try_get("oid"),
self._re_auth_token.get_value(),
)
self.read_response()
self._re_auth_token = None
def _get_socket(self) -> Optional[socket.socket]:
return self._sock
@property
def socket_timeout(self) -> Optional[Union[float, int]]:
return self._socket_timeout
@socket_timeout.setter
def socket_timeout(self, value: Optional[Union[float, int]]):
self._socket_timeout = value
@property
def socket_connect_timeout(self) -> Optional[Union[float, int]]:
return self._socket_connect_timeout
@socket_connect_timeout.setter
def socket_connect_timeout(self, value: Optional[Union[float, int]]):
self._socket_connect_timeout = value
class Connection(AbstractConnection):
"Manages TCP communication to and from a Redis server"
def __init__(
self,
host="localhost",
port=6379,
socket_keepalive=False,
socket_keepalive_options=None,
socket_type=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 _connect(self):
"Create a TCP socket connection"
# we want to mimic what socket.create_connection does to support
# ipv4/ipv6, but we want to set options prior to calling
# socket.connect()
err = None
for res in socket.getaddrinfo(
self.host, self.port, self.socket_type, socket.SOCK_STREAM
):
family, socktype, proto, canonname, socket_address = res
sock = None
try:
sock = socket.socket(family, socktype, proto)
# TCP_NODELAY
sock.setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
# 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.IPPROTO_TCP, k, v)
# set the socket_connect_timeout before we connect
sock.settimeout(self.socket_connect_timeout)
# connect
sock.connect(socket_address)
# set the socket_timeout now that we're connected
sock.settimeout(self.socket_timeout)
return sock
except OSError as _:
err = _
if sock is not None:
try:
sock.shutdown(socket.SHUT_RDWR) # ensure a clean close
except OSError:
pass
sock.close()
if err is not None:
raise err
raise OSError("socket.getaddrinfo returned an empty list")
def _host_error(self):
return f"{self.host}:{self.port}"
@property
def host(self) -> str:
return self._host
@host.setter
def host(self, value: str):
self._host = value
class CacheProxyConnection(MaintNotificationsAbstractConnection, ConnectionInterface):
DUMMY_CACHE_VALUE = b"foo"
MIN_ALLOWED_VERSION = "7.4.0"
DEFAULT_SERVER_NAME = "redis"
def __init__(
self,
conn: ConnectionInterface,
cache: CacheInterface,
pool_lock: threading.RLock,
):
self.pid = os.getpid()
self._conn = conn
self.retry = self._conn.retry
self.host = self._conn.host
self.port = self._conn.port
self.credential_provider = conn.credential_provider
self._pool_lock = pool_lock
self._cache = cache
self._cache_lock = threading.RLock()
self._current_command_cache_key = None
self._current_options = None
self.register_connect_callback(self._enable_tracking_callback)
if isinstance(self._conn, MaintNotificationsAbstractConnection):
MaintNotificationsAbstractConnection.__init__(
self,
self._conn.maint_notifications_config,
self._conn._maint_notifications_pool_handler,
self._conn.maintenance_state,
self._conn.maintenance_notification_hash,
self._conn.host,
self._conn.socket_timeout,
self._conn.socket_connect_timeout,
self._conn._get_parser(),
)
def repr_pieces(self):
return self._conn.repr_pieces()
def register_connect_callback(self, callback):
self._conn.register_connect_callback(callback)
def deregister_connect_callback(self, callback):
self._conn.deregister_connect_callback(callback)
def set_parser(self, parser_class):
self._conn.set_parser(parser_class)
def set_maint_notifications_pool_handler_for_connection(
self, maint_notifications_pool_handler
):
if isinstance(self._conn, MaintNotificationsAbstractConnection):
self._conn.set_maint_notifications_pool_handler_for_connection(
maint_notifications_pool_handler
)
def get_protocol(self):
return self._conn.get_protocol()
def connect(self):
self._conn.connect()
server_name = self._conn.handshake_metadata.get(b"server", None)
if server_name is None:
server_name = self._conn.handshake_metadata.get("server", None)
server_ver = self._conn.handshake_metadata.get(b"version", None)
if server_ver is None:
server_ver = self._conn.handshake_metadata.get("version", None)
if server_ver is None or server_ver is None:
raise ConnectionError("Cannot retrieve information about server version")
server_ver = ensure_string(server_ver)
server_name = ensure_string(server_name)
if (
server_name != self.DEFAULT_SERVER_NAME
or compare_versions(server_ver, self.MIN_ALLOWED_VERSION) == 1
):
raise ConnectionError(
"To maximize compatibility with all Redis products, client-side caching is supported by Redis 7.4 or later" # noqa: E501
)
def on_connect(self):
self._conn.on_connect()
def disconnect(self, *args):
with self._cache_lock:
self._cache.flush()
self._conn.disconnect(*args)
def check_health(self):
self._conn.check_health()
def send_packed_command(self, command, check_health=True):
# TODO: Investigate if it's possible to unpack command
# or extract keys from packed command
self._conn.send_packed_command(command)
def send_command(self, *args, **kwargs):
self._process_pending_invalidations()
with self._cache_lock:
# Command is write command or not allowed
# to be cached.
if not self._cache.is_cachable(
CacheKey(command=args[0], redis_keys=(), redis_args=())
):
self._current_command_cache_key = None
self._conn.send_command(*args, **kwargs)
return
if kwargs.get("keys") is None:
raise ValueError("Cannot create cache key.")
# Creates cache key.
self._current_command_cache_key = CacheKey(
command=args[0], redis_keys=tuple(kwargs.get("keys")), redis_args=args
)
with self._cache_lock:
# We have to trigger invalidation processing in case if
# it was cached by another connection to avoid
# queueing invalidations in stale connections.
if self._cache.get(self._current_command_cache_key):
entry = self._cache.get(self._current_command_cache_key)
if entry.connection_ref != self._conn:
with self._pool_lock:
while entry.connection_ref.can_read():
entry.connection_ref.read_response(push_request=True)
return
# Set temporary entry value to prevent
# race condition from another connection.
self._cache.set(
CacheEntry(
cache_key=self._current_command_cache_key,
cache_value=self.DUMMY_CACHE_VALUE,
status=CacheEntryStatus.IN_PROGRESS,
connection_ref=self._conn,
)
)
# Send command over socket only if it's allowed
# read-only command that not yet cached.
self._conn.send_command(*args, **kwargs)
def can_read(self, timeout=0):
return self._conn.can_read(timeout)
def read_response(
self, disable_decoding=False, *, disconnect_on_error=True, push_request=False
):
with self._cache_lock:
# Check if command response exists in a cache and it's not in progress.
if (
self._current_command_cache_key is not None
and self._cache.get(self._current_command_cache_key) is not None
and self._cache.get(self._current_command_cache_key).status
!= CacheEntryStatus.IN_PROGRESS
):
res = copy.deepcopy(
self._cache.get(self._current_command_cache_key).cache_value
)
self._current_command_cache_key = None
return res
response = self._conn.read_response(
disable_decoding=disable_decoding,
disconnect_on_error=disconnect_on_error,
push_request=push_request,
)
with self._cache_lock:
# Prevent not-allowed command from caching.
if self._current_command_cache_key is None:
return response
# If response is None prevent from caching.
if response is None:
self._cache.delete_by_cache_keys([self._current_command_cache_key])
return response
cache_entry = self._cache.get(self._current_command_cache_key)
# Cache only responses that still valid
# and wasn't invalidated by another connection in meantime.
if cache_entry is not None:
cache_entry.status = CacheEntryStatus.VALID
cache_entry.cache_value = response
self._cache.set(cache_entry)
self._current_command_cache_key = None
return response
def pack_command(self, *args):
return self._conn.pack_command(*args)
def pack_commands(self, commands):
return self._conn.pack_commands(commands)
@property
def handshake_metadata(self) -> Union[Dict[bytes, bytes], Dict[str, str]]:
return self._conn.handshake_metadata
def set_re_auth_token(self, token: TokenInterface):
self._conn.set_re_auth_token(token)
def re_auth(self):
self._conn.re_auth()
def mark_for_reconnect(self):
self._conn.mark_for_reconnect()
def should_reconnect(self):
return self._conn.should_reconnect()
def reset_should_reconnect(self):
self._conn.reset_should_reconnect()
@property
def host(self) -> str:
return self._conn.host
@host.setter
def host(self, value: str):
self._conn.host = value
@property
def socket_timeout(self) -> Optional[Union[float, int]]:
return self._conn.socket_timeout
@socket_timeout.setter
def socket_timeout(self, value: Optional[Union[float, int]]):
self._conn.socket_timeout = value
@property
def socket_connect_timeout(self) -> Optional[Union[float, int]]:
return self._conn.socket_connect_timeout
@socket_connect_timeout.setter
def socket_connect_timeout(self, value: Optional[Union[float, int]]):
self._conn.socket_connect_timeout = value
def _get_socket(self) -> Optional[socket.socket]:
if isinstance(self._conn, MaintNotificationsAbstractConnection):
return self._conn._get_socket()
else:
raise NotImplementedError(
"Maintenance notifications are not supported by this connection type"
)
def _get_maint_notifications_connection_instance(
self, connection
) -> MaintNotificationsAbstractConnection:
"""
Validate that connection instance supports maintenance notifications.
With this helper method we ensure that we are working
with the correct connection type.
After twe validate that connection instance supports maintenance notifications
we can safely return the connection instance
as MaintNotificationsAbstractConnection.
"""
if not isinstance(connection, MaintNotificationsAbstractConnection):
raise NotImplementedError(
"Maintenance notifications are not supported by this connection type"
)
else:
return connection
@property
def maintenance_state(self) -> MaintenanceState:
con = self._get_maint_notifications_connection_instance(self._conn)
return con.maintenance_state
@maintenance_state.setter
def maintenance_state(self, state: MaintenanceState):
con = self._get_maint_notifications_connection_instance(self._conn)
con.maintenance_state = state
def getpeername(self):
con = self._get_maint_notifications_connection_instance(self._conn)
return con.getpeername()
def get_resolved_ip(self):
con = self._get_maint_notifications_connection_instance(self._conn)
return con.get_resolved_ip()
def update_current_socket_timeout(self, relaxed_timeout: Optional[float] = None):
con = self._get_maint_notifications_connection_instance(self._conn)
con.update_current_socket_timeout(relaxed_timeout)
def set_tmp_settings(
self,
tmp_host_address: Optional[str] = None,
tmp_relaxed_timeout: Optional[float] = None,
):
con = self._get_maint_notifications_connection_instance(self._conn)
con.set_tmp_settings(tmp_host_address, tmp_relaxed_timeout)
def reset_tmp_settings(
self,
reset_host_address: bool = False,
reset_relaxed_timeout: bool = False,
):
con = self._get_maint_notifications_connection_instance(self._conn)
con.reset_tmp_settings(reset_host_address, reset_relaxed_timeout)
def _connect(self):
self._conn._connect()
def _host_error(self):
self._conn._host_error()
def _enable_tracking_callback(self, conn: ConnectionInterface) -> None:
conn.send_command("CLIENT", "TRACKING", "ON")
conn.read_response()
conn._parser.set_invalidation_push_handler(self._on_invalidation_callback)
def _process_pending_invalidations(self):
while self.can_read():
self._conn.read_response(push_request=True)
def _on_invalidation_callback(self, data: List[Union[str, Optional[List[bytes]]]]):
with self._cache_lock:
# Flush cache when DB flushed on server-side
if data[1] is None:
self._cache.flush()
else:
self._cache.delete_by_redis_keys(data[1])
class SSLConnection(Connection):
"""Manages SSL connections to and from the Redis 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)
""" # noqa
def __init__(
self,
ssl_keyfile=None,
ssl_certfile=None,
ssl_cert_reqs="required",
ssl_include_verify_flags: Optional[List["VerifyFlags"]] = None,
ssl_exclude_verify_flags: Optional[List["VerifyFlags"]] = None,
ssl_ca_certs=None,
ssl_ca_data=None,
ssl_check_hostname=True,
ssl_ca_path=None,
ssl_password=None,
ssl_validate_ocsp=False,
ssl_validate_ocsp_stapled=False,
ssl_ocsp_context=None,
ssl_ocsp_expected_cert=None,
ssl_min_version=None,
ssl_ciphers=None,
**kwargs,
):
"""Constructor
Args:
ssl_keyfile: Path to an ssl private key. Defaults to None.
ssl_certfile: Path to an ssl certificate. Defaults to None.
ssl_cert_reqs: The string value for the SSLContext.verify_mode (none, optional, required),
or an ssl.VerifyMode. Defaults to "required".
ssl_include_verify_flags: A list of flags to be included in the SSLContext.verify_flags. Defaults to None.
ssl_exclude_verify_flags: A list of flags to be excluded from the SSLContext.verify_flags. Defaults to None.
ssl_ca_certs: The path to a file of concatenated CA certificates in PEM format. Defaults to None.
ssl_ca_data: Either an ASCII string of one or more PEM-encoded certificates or a bytes-like object of DER-encoded certificates.
ssl_check_hostname: If set, match the hostname during the SSL handshake. Defaults to True.
ssl_ca_path: The path to a directory containing several CA certificates in PEM format. Defaults to None.
ssl_password: Password for unlocking an encrypted private key. Defaults to None.
ssl_validate_ocsp: If set, perform a full ocsp validation (i.e not a stapled verification)
ssl_validate_ocsp_stapled: If set, perform a validation on a stapled ocsp response
ssl_ocsp_context: A fully initialized OpenSSL.SSL.Context object to be used in verifying the ssl_ocsp_expected_cert
ssl_ocsp_expected_cert: A PEM armoured string containing the expected certificate to be returned from the ocsp verification service.
ssl_min_version: The lowest supported SSL version. It affects the supported SSL versions of the SSLContext. None leaves the default provided by ssl module.
ssl_ciphers: A string listing the ciphers that are allowed to be used. Defaults to None, which means that the default ciphers are used. See https://docs.python.org/3/library/ssl.html#ssl.SSLContext.set_ciphers for more information.
Raises:
RedisError
""" # noqa
if not SSL_AVAILABLE:
raise RedisError("Python wasn't built with SSL support")
self.keyfile = ssl_keyfile
self.certfile = ssl_certfile
if ssl_cert_reqs is None:
ssl_cert_reqs = ssl.CERT_NONE
elif isinstance(ssl_cert_reqs, str):
CERT_REQS = { # noqa: N806
"none": ssl.CERT_NONE,
"optional": ssl.CERT_OPTIONAL,
"required": ssl.CERT_REQUIRED,
}
if ssl_cert_reqs not in CERT_REQS:
raise RedisError(
f"Invalid SSL Certificate Requirements Flag: {ssl_cert_reqs}"
)
ssl_cert_reqs = CERT_REQS[ssl_cert_reqs]
self.cert_reqs = ssl_cert_reqs
self.ssl_include_verify_flags = ssl_include_verify_flags
self.ssl_exclude_verify_flags = ssl_exclude_verify_flags
self.ca_certs = ssl_ca_certs
self.ca_data = ssl_ca_data
self.ca_path = ssl_ca_path
self.check_hostname = (
ssl_check_hostname if self.cert_reqs != ssl.CERT_NONE else False
)
self.certificate_password = ssl_password
self.ssl_validate_ocsp = ssl_validate_ocsp
self.ssl_validate_ocsp_stapled = ssl_validate_ocsp_stapled
self.ssl_ocsp_context = ssl_ocsp_context
self.ssl_ocsp_expected_cert = ssl_ocsp_expected_cert
self.ssl_min_version = ssl_min_version
self.ssl_ciphers = ssl_ciphers
super().__init__(**kwargs)
def _connect(self):
"""
Wrap the socket with SSL support, handling potential errors.
"""
sock = super()._connect()
try:
return self._wrap_socket_with_ssl(sock)
except (OSError, RedisError):
sock.close()
raise
def _wrap_socket_with_ssl(self, sock):
"""
Wraps the socket with SSL support.
Args:
sock: The plain socket to wrap with SSL.
Returns:
An SSL wrapped socket.
"""
context = ssl.create_default_context()
context.check_hostname = self.check_hostname
context.verify_mode = self.cert_reqs
if self.ssl_include_verify_flags:
for flag in self.ssl_include_verify_flags:
context.verify_flags |= flag
if self.ssl_exclude_verify_flags:
for flag in self.ssl_exclude_verify_flags:
context.verify_flags &= ~flag
if self.certfile or self.keyfile:
context.load_cert_chain(
certfile=self.certfile,
keyfile=self.keyfile,
password=self.certificate_password,
)
if (
self.ca_certs is not None
or self.ca_path is not None
or self.ca_data is not None
):
context.load_verify_locations(
cafile=self.ca_certs, capath=self.ca_path, cadata=self.ca_data
)
if self.ssl_min_version is not None:
context.minimum_version = self.ssl_min_version
if self.ssl_ciphers:
context.set_ciphers(self.ssl_ciphers)
if self.ssl_validate_ocsp is True and CRYPTOGRAPHY_AVAILABLE is False:
raise RedisError("cryptography is not installed.")
if self.ssl_validate_ocsp_stapled and self.ssl_validate_ocsp:
raise RedisError(
"Either an OCSP staple or pure OCSP connection must be validated "
"- not both."
)
sslsock = context.wrap_socket(sock, server_hostname=self.host)
# validation for the stapled case
if self.ssl_validate_ocsp_stapled:
import OpenSSL
from .ocsp import ocsp_staple_verifier
# if a context is provided use it - otherwise, a basic context
if self.ssl_ocsp_context is None:
staple_ctx = OpenSSL.SSL.Context(OpenSSL.SSL.SSLv23_METHOD)
staple_ctx.use_certificate_file(self.certfile)
staple_ctx.use_privatekey_file(self.keyfile)
else:
staple_ctx = self.ssl_ocsp_context
staple_ctx.set_ocsp_client_callback(
ocsp_staple_verifier, self.ssl_ocsp_expected_cert
)
# need another socket
con = OpenSSL.SSL.Connection(staple_ctx, socket.socket())
con.request_ocsp()
con.connect((self.host, self.port))
con.do_handshake()
con.shutdown()
return sslsock
# pure ocsp validation
if self.ssl_validate_ocsp is True and CRYPTOGRAPHY_AVAILABLE:
from .ocsp import OCSPVerifier
o = OCSPVerifier(sslsock, self.host, self.port, self.ca_certs)
if o.is_valid():
return sslsock
else:
raise ConnectionError("ocsp validation error")
return sslsock
class UnixDomainSocketConnection(AbstractConnection):
"Manages UDS communication to and from a Redis server"
def __init__(self, path="", socket_timeout=None, **kwargs):
super().__init__(**kwargs)
self.path = path
self.socket_timeout = socket_timeout
def repr_pieces(self):
pieces = [("path", self.path), ("db", self.db)]
if self.client_name:
pieces.append(("client_name", self.client_name))
return pieces
def _connect(self):
"Create a Unix domain socket connection"
sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
sock.settimeout(self.socket_connect_timeout)
try:
sock.connect(self.path)
except OSError:
# Prevent ResourceWarnings for unclosed sockets.
try:
sock.shutdown(socket.SHUT_RDWR) # ensure a clean close
except OSError:
pass
sock.close()
raise
sock.settimeout(self.socket_timeout)
return sock
def _host_error(self):
return self.path
FALSE_STRINGS = ("0", "F", "FALSE", "N", "NO")
def to_bool(value):
if value is None or value == "":
return None
if isinstance(value, str) and value.upper() in FALSE_STRINGS:
return False
return bool(value)
def parse_ssl_verify_flags(value):
# flags are passed in as a string representation of a list,
# e.g. VERIFY_X509_STRICT, VERIFY_X509_PARTIAL_CHAIN
verify_flags_str = value.replace("[", "").replace("]", "")
verify_flags = []
for flag in verify_flags_str.split(","):
flag = flag.strip()
if not hasattr(VerifyFlags, flag):
raise ValueError(f"Invalid ssl verify flag: {flag}")
verify_flags.append(getattr(VerifyFlags, flag))
return verify_flags
URL_QUERY_ARGUMENT_PARSERS = {
"db": int,
"socket_timeout": float,
"socket_connect_timeout": float,
"socket_keepalive": to_bool,
"retry_on_timeout": to_bool,
"retry_on_error": list,
"max_connections": int,
"health_check_interval": int,
"ssl_check_hostname": to_bool,
"ssl_include_verify_flags": parse_ssl_verify_flags,
"ssl_exclude_verify_flags": parse_ssl_verify_flags,
"timeout": float,
}
def parse_url(url):
if not (
url.startswith("redis://")
or url.startswith("rediss://")
or url.startswith("unix://")
):
raise ValueError(
"Redis URL must specify one of the following "
"schemes (redis://, rediss://, unix://)"
)
url = urlparse(url)
kwargs = {}
for name, value in parse_qs(url.query).items():
if value and len(value) > 0:
value = unquote(value[0])
parser = URL_QUERY_ARGUMENT_PARSERS.get(name)
if parser:
try:
kwargs[name] = parser(value)
except (TypeError, ValueError):
raise ValueError(f"Invalid value for '{name}' in connection URL.")
else:
kwargs[name] = value
if url.username:
kwargs["username"] = unquote(url.username)
if url.password:
kwargs["password"] = unquote(url.password)
# We only support redis://, rediss:// and unix:// schemes.
if url.scheme == "unix":
if url.path:
kwargs["path"] = unquote(url.path)
kwargs["connection_class"] = UnixDomainSocketConnection
else: # implied: url.scheme in ("redis", "rediss"):
if url.hostname:
kwargs["host"] = unquote(url.hostname)
if url.port:
kwargs["port"] = int(url.port)
# If there's a path argument, use it as the db argument if a
# querystring value wasn't specified
if url.path and "db" not in kwargs:
try:
kwargs["db"] = int(unquote(url.path).replace("/", ""))
except (AttributeError, ValueError):
pass
if url.scheme == "rediss":
kwargs["connection_class"] = SSLConnection
return kwargs
_CP = TypeVar("_CP", bound="ConnectionPool")
class ConnectionPoolInterface(ABC):
@abstractmethod
def get_protocol(self):
pass
@abstractmethod
def reset(self):
pass
@abstractmethod
@deprecated_args(
args_to_warn=["*"],
reason="Use get_connection() without args instead",
version="5.3.0",
)
def get_connection(
self, command_name: Optional[str], *keys, **options
) -> ConnectionInterface:
pass
@abstractmethod
def get_encoder(self):
pass
@abstractmethod
def release(self, connection: ConnectionInterface):
pass
@abstractmethod
def disconnect(self, inuse_connections: bool = True):
pass
@abstractmethod
def close(self):
pass
@abstractmethod
def set_retry(self, retry: Retry):
pass
@abstractmethod
def re_auth_callback(self, token: TokenInterface):
pass
class MaintNotificationsAbstractConnectionPool:
"""
Abstract class for handling maintenance notifications logic.
This class is mixed into the ConnectionPool classes.
This class is not intended to be used directly!
All logic related to maintenance notifications and
connection pool handling is encapsulated in this class.
"""
def __init__(
self,
maint_notifications_config: Optional[MaintNotificationsConfig] = None,
**kwargs,
):
# Initialize maintenance notifications
is_protocol_supported = kwargs.get("protocol") in [3, "3"]
if maint_notifications_config is None and is_protocol_supported:
maint_notifications_config = MaintNotificationsConfig()
if maint_notifications_config and maint_notifications_config.enabled:
if not is_protocol_supported:
raise RedisError(
"Maintenance notifications handlers on connection are only supported with RESP version 3"
)
self._maint_notifications_pool_handler = MaintNotificationsPoolHandler(
self, maint_notifications_config
)
self._update_connection_kwargs_for_maint_notifications(
self._maint_notifications_pool_handler
)
else:
self._maint_notifications_pool_handler = None
@property
@abstractmethod
def connection_kwargs(self) -> Dict[str, Any]:
pass
@connection_kwargs.setter
@abstractmethod
def connection_kwargs(self, value: Dict[str, Any]):
pass
@abstractmethod
def _get_pool_lock(self) -> threading.RLock:
pass
@abstractmethod
def _get_free_connections(self) -> Iterable["MaintNotificationsAbstractConnection"]:
pass
@abstractmethod
def _get_in_use_connections(
self,
) -> Iterable["MaintNotificationsAbstractConnection"]:
pass
def maint_notifications_enabled(self):
"""
Returns:
True if the maintenance notifications are enabled, False otherwise.
The maintenance notifications config is stored in the pool handler.
If the pool handler is not set, the maintenance notifications are not enabled.
"""
maint_notifications_config = (
self._maint_notifications_pool_handler.config
if self._maint_notifications_pool_handler
else None
)
return maint_notifications_config and maint_notifications_config.enabled
def update_maint_notifications_config(
self, maint_notifications_config: MaintNotificationsConfig
):
"""
Updates the maintenance notifications configuration.
This method should be called only if the pool was created
without enabling the maintenance notifications and
in a later point in time maintenance notifications
are requested to be enabled.
"""
if (
self.maint_notifications_enabled()
and not maint_notifications_config.enabled
):
raise ValueError(
"Cannot disable maintenance notifications after enabling them"
)
# first update pool settings
if not self._maint_notifications_pool_handler:
self._maint_notifications_pool_handler = MaintNotificationsPoolHandler(
self, maint_notifications_config
)
else:
self._maint_notifications_pool_handler.config = maint_notifications_config
# then update connection kwargs and existing connections
self._update_connection_kwargs_for_maint_notifications(
self._maint_notifications_pool_handler
)
self._update_maint_notifications_configs_for_connections(
self._maint_notifications_pool_handler
)
def _update_connection_kwargs_for_maint_notifications(
self, maint_notifications_pool_handler: MaintNotificationsPoolHandler
):
"""
Update the connection kwargs for all future connections.
"""
if not self.maint_notifications_enabled():
return
self.connection_kwargs.update(
{
"maint_notifications_pool_handler": maint_notifications_pool_handler,
"maint_notifications_config": maint_notifications_pool_handler.config,
}
)
# Store original connection parameters for maintenance notifications.
if self.connection_kwargs.get("orig_host_address", None) is None:
# If orig_host_address is None it means we haven't
# configured the original values yet
self.connection_kwargs.update(
{
"orig_host_address": self.connection_kwargs.get("host"),
"orig_socket_timeout": self.connection_kwargs.get(
"socket_timeout", None
),
"orig_socket_connect_timeout": self.connection_kwargs.get(
"socket_connect_timeout", None
),
}
)
def _update_maint_notifications_configs_for_connections(
self, maint_notifications_pool_handler: MaintNotificationsPoolHandler
):
"""Update the maintenance notifications config for all connections in the pool."""
with self._get_pool_lock():
for conn in self._get_free_connections():
conn.set_maint_notifications_pool_handler_for_connection(
maint_notifications_pool_handler
)
conn.maint_notifications_config = (
maint_notifications_pool_handler.config
)
conn.disconnect()
for conn in self._get_in_use_connections():
conn.set_maint_notifications_pool_handler_for_connection(
maint_notifications_pool_handler
)
conn.maint_notifications_config = (
maint_notifications_pool_handler.config
)
conn.mark_for_reconnect()
def _should_update_connection(
self,
conn: "MaintNotificationsAbstractConnection",
matching_pattern: Literal[
"connected_address", "configured_address", "notification_hash"
] = "connected_address",
matching_address: Optional[str] = None,
matching_notification_hash: Optional[int] = None,
) -> bool:
"""
Check if the connection should be updated based on the matching criteria.
"""
if matching_pattern == "connected_address":
if matching_address and conn.getpeername() != matching_address:
return False
elif matching_pattern == "configured_address":
if matching_address and conn.host != matching_address:
return False
elif matching_pattern == "notification_hash":
if (
matching_notification_hash
and conn.maintenance_notification_hash != matching_notification_hash
):
return False
return True
def update_connection_settings(
self,
conn: "MaintNotificationsAbstractConnection",
state: Optional["MaintenanceState"] = None,
maintenance_notification_hash: Optional[int] = None,
host_address: Optional[str] = None,
relaxed_timeout: Optional[float] = None,
update_notification_hash: bool = False,
reset_host_address: bool = False,
reset_relaxed_timeout: bool = False,
):
"""
Update the settings for a single connection.
"""
if state:
conn.maintenance_state = state
if update_notification_hash:
# update the notification hash only if requested
conn.maintenance_notification_hash = maintenance_notification_hash
if host_address is not None:
conn.set_tmp_settings(tmp_host_address=host_address)
if relaxed_timeout is not None:
conn.set_tmp_settings(tmp_relaxed_timeout=relaxed_timeout)
if reset_relaxed_timeout or reset_host_address:
conn.reset_tmp_settings(
reset_host_address=reset_host_address,
reset_relaxed_timeout=reset_relaxed_timeout,
)
conn.update_current_socket_timeout(relaxed_timeout)
def update_connections_settings(
self,
state: Optional["MaintenanceState"] = None,
maintenance_notification_hash: Optional[int] = None,
host_address: Optional[str] = None,
relaxed_timeout: Optional[float] = None,
matching_address: Optional[str] = None,
matching_notification_hash: Optional[int] = None,
matching_pattern: Literal[
"connected_address", "configured_address", "notification_hash"
] = "connected_address",
update_notification_hash: bool = False,
reset_host_address: bool = False,
reset_relaxed_timeout: bool = False,
include_free_connections: bool = True,
):
"""
Update the settings for all matching connections in the pool.
This method does not create new connections.
This method does not affect the connection kwargs.
:param state: The maintenance state to set for the connection.
:param maintenance_notification_hash: The hash of the maintenance notification
to set for the connection.
:param host_address: The host address to set for the connection.
:param relaxed_timeout: The relaxed timeout to set for the connection.
:param matching_address: The address to match for the connection.
:param matching_notification_hash: The notification hash to match for the connection.
:param matching_pattern: The pattern to match for the connection.
:param update_notification_hash: Whether to update the notification hash for the connection.
:param reset_host_address: Whether to reset the host address to the original address.
:param reset_relaxed_timeout: Whether to reset the relaxed timeout to the original timeout.
:param include_free_connections: Whether to include free/available connections.
"""
with self._get_pool_lock():
for conn in self._get_in_use_connections():
if self._should_update_connection(
conn,
matching_pattern,
matching_address,
matching_notification_hash,
):
self.update_connection_settings(
conn,
state=state,
maintenance_notification_hash=maintenance_notification_hash,
host_address=host_address,
relaxed_timeout=relaxed_timeout,
update_notification_hash=update_notification_hash,
reset_host_address=reset_host_address,
reset_relaxed_timeout=reset_relaxed_timeout,
)
if include_free_connections:
for conn in self._get_free_connections():
if self._should_update_connection(
conn,
matching_pattern,
matching_address,
matching_notification_hash,
):
self.update_connection_settings(
conn,
state=state,
maintenance_notification_hash=maintenance_notification_hash,
host_address=host_address,
relaxed_timeout=relaxed_timeout,
update_notification_hash=update_notification_hash,
reset_host_address=reset_host_address,
reset_relaxed_timeout=reset_relaxed_timeout,
)
def update_connection_kwargs(
self,
**kwargs,
):
"""
Update the connection kwargs for all future connections.
This method updates the connection kwargs for all future connections created by the pool.
Existing connections are not affected.
"""
self.connection_kwargs.update(kwargs)
def update_active_connections_for_reconnect(
self,
moving_address_src: Optional[str] = None,
):
"""
Mark all active connections for reconnect.
This is used when a cluster node is migrated to a different address.
:param moving_address_src: The address of the node that is being moved.
"""
with self._get_pool_lock():
for conn in self._get_in_use_connections():
if self._should_update_connection(
conn, "connected_address", moving_address_src
):
conn.mark_for_reconnect()
def disconnect_free_connections(
self,
moving_address_src: Optional[str] = None,
):
"""
Disconnect all free/available connections.
This is used when a cluster node is migrated to a different address.
:param moving_address_src: The address of the node that is being moved.
"""
with self._get_pool_lock():
for conn in self._get_free_connections():
if self._should_update_connection(
conn, "connected_address", moving_address_src
):
conn.disconnect()
class ConnectionPool(MaintNotificationsAbstractConnectionPool, ConnectionPoolInterface):
"""
Create a connection pool. ``If max_connections`` is set, then this
object raises :py:class:`~redis.exceptions.ConnectionError` when the pool's
limit is reached.
By default, TCP connections are created unless ``connection_class``
is specified. Use class:`.UnixDomainSocketConnection` for
unix sockets.
:py:class:`~redis.SSLConnection` can be used for SSL enabled connections.
If ``maint_notifications_config`` is provided, the connection pool will support
maintenance notifications.
Maintenance notifications are supported only with RESP3.
If the ``maint_notifications_config`` is not provided but the ``protocol`` is 3,
the maintenance notifications will be enabled by default.
Any additional keyword arguments are passed to the constructor of
``connection_class``.
"""
@classmethod
def from_url(cls: Type[_CP], url: str, **kwargs) -> _CP:
"""
Return a connection pool configured from the given URL.
For example::
redis://[[username]:[password]]@localhost:6379/0
rediss://[[username]:[password]]@localhost:6379/0
unix://[username@]/path/to/socket.sock?db=0[&password=password]
Three URL schemes are supported:
- `redis://` creates a TCP socket connection. See more at:
<https://www.iana.org/assignments/uri-schemes/prov/redis>
- `rediss://` creates a SSL wrapped TCP socket connection. See more at:
<https://www.iana.org/assignments/uri-schemes/prov/rediss>
- ``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. redis://localhost?db=0
2. If using the redis:// or rediss:// schemes, the path argument
of the url, e.g. redis://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)
if "connection_class" in kwargs:
url_options["connection_class"] = kwargs["connection_class"]
kwargs.update(url_options)
return cls(**kwargs)
def __init__(
self,
connection_class=Connection,
max_connections: Optional[int] = None,
cache_factory: Optional[CacheFactoryInterface] = None,
maint_notifications_config: Optional[MaintNotificationsConfig] = 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.cache = None
self._cache_factory = cache_factory
if connection_kwargs.get("cache_config") or connection_kwargs.get("cache"):
if self._connection_kwargs.get("protocol") not in [3, "3"]:
raise RedisError("Client caching is only supported with RESP version 3")
cache = self._connection_kwargs.get("cache")
if cache is not None:
if not isinstance(cache, CacheInterface):
raise ValueError("Cache must implement CacheInterface")
self.cache = cache
else:
if self._cache_factory is not None:
self.cache = self._cache_factory.get_cache()
else:
self.cache = CacheFactory(
self._connection_kwargs.get("cache_config")
).get_cache()
connection_kwargs.pop("cache", None)
connection_kwargs.pop("cache_config", None)
self._event_dispatcher = self._connection_kwargs.get("event_dispatcher", None)
if self._event_dispatcher is None:
self._event_dispatcher = EventDispatcher()
# a lock to protect the critical section in _checkpid().
# this lock is acquired when the process id changes, such as
# after a fork. during this time, multiple threads in the child
# process could attempt to acquire this lock. the first thread
# to acquire the lock will reset the data structures and lock
# object of this pool. subsequent threads acquiring this lock
# will notice the first thread already did the work and simply
# release the lock.
self._fork_lock = threading.RLock()
self._lock = threading.RLock()
MaintNotificationsAbstractConnectionPool.__init__(
self,
maint_notifications_config=maint_notifications_config,
**connection_kwargs,
)
self.reset()
def __repr__(self) -> str:
conn_kwargs = ",".join([f"{k}={v}" for k, v in self.connection_kwargs.items()])
return (
f"<{self.__class__.__module__}.{self.__class__.__name__}"
f"(<{self.connection_class.__module__}.{self.connection_class.__name__}"
f"({conn_kwargs})>)>"
)
@property
def connection_kwargs(self) -> Dict[str, Any]:
return self._connection_kwargs
@connection_kwargs.setter
def connection_kwargs(self, value: Dict[str, Any]):
self._connection_kwargs = value
def get_protocol(self):
"""
Returns:
The RESP protocol version, or ``None`` if the protocol is not specified,
in which case the server default will be used.
"""
return self.connection_kwargs.get("protocol", None)
def reset(self) -> None:
self._created_connections = 0
self._available_connections = []
self._in_use_connections = set()
# this must be the last operation in this method. while reset() is
# called when holding _fork_lock, other threads in this process
# can call _checkpid() which compares self.pid and os.getpid() without
# holding any lock (for performance reasons). keeping this assignment
# as the last operation ensures that those other threads will also
# notice a pid difference and block waiting for the first thread to
# release _fork_lock. when each of these threads eventually acquire
# _fork_lock, they will notice that another thread already called
# reset() and they will immediately release _fork_lock and continue on.
self.pid = os.getpid()
def _checkpid(self) -> None:
# _checkpid() attempts to keep ConnectionPool fork-safe on modern
# systems. this is called by all ConnectionPool methods that
# manipulate the pool's state such as get_connection() and release().
#
# _checkpid() determines whether the process has forked by comparing
# the current process id to the process id saved on the ConnectionPool
# instance. if these values are the same, _checkpid() simply returns.
#
# when the process ids differ, _checkpid() assumes that the process
# has forked and that we're now running in the child process. the child
# process cannot use the parent's file descriptors (e.g., sockets).
# therefore, when _checkpid() sees the process id change, it calls
# reset() in order to reinitialize the child's ConnectionPool. this
# will cause the child to make all new connection objects.
#
# _checkpid() is protected by self._fork_lock to ensure that multiple
# threads in the child process do not call reset() multiple times.
#
# there is an extremely small chance this could fail in the following
# scenario:
# 1. process A calls _checkpid() for the first time and acquires
# self._fork_lock.
# 2. while holding self._fork_lock, process A forks (the fork()
# could happen in a different thread owned by process A)
# 3. process B (the forked child process) inherits the
# ConnectionPool's state from the parent. that state includes
# a locked _fork_lock. process B will not be notified when
# process A releases the _fork_lock and will thus never be
# able to acquire the _fork_lock.
#
# to mitigate this possible deadlock, _checkpid() will only wait 5
# seconds to acquire _fork_lock. if _fork_lock cannot be acquired in
# that time it is assumed that the child is deadlocked and a
# redis.ChildDeadlockedError error is raised.
if self.pid != os.getpid():
acquired = self._fork_lock.acquire(timeout=5)
if not acquired:
raise ChildDeadlockedError
# reset() the instance for the new process if another thread
# hasn't already done so
try:
if self.pid != os.getpid():
self.reset()
finally:
self._fork_lock.release()
@deprecated_args(
args_to_warn=["*"],
reason="Use get_connection() without args instead",
version="5.3.0",
)
def get_connection(self, command_name=None, *keys, **options) -> "Connection":
"Get a connection from the pool"
self._checkpid()
with self._lock:
try:
connection = self._available_connections.pop()
except IndexError:
connection = self.make_connection()
self._in_use_connections.add(connection)
try:
# ensure this connection is connected to Redis
connection.connect()
# 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.
try:
if (
connection.can_read()
and self.cache is None
and not self.maint_notifications_enabled()
):
raise ConnectionError("Connection has data")
except (ConnectionError, TimeoutError, OSError):
connection.disconnect()
connection.connect()
if connection.can_read():
raise ConnectionError("Connection not ready")
except BaseException:
# release the connection back to the pool so that we don't
# leak it
self.release(connection)
raise
return connection
def get_encoder(self) -> Encoder:
"Return an encoder based on encoding settings"
kwargs = self.connection_kwargs
return Encoder(
encoding=kwargs.get("encoding", "utf-8"),
encoding_errors=kwargs.get("encoding_errors", "strict"),
decode_responses=kwargs.get("decode_responses", False),
)
def make_connection(self) -> "ConnectionInterface":
"Create a new connection"
if self._created_connections >= self.max_connections:
raise MaxConnectionsError("Too many connections")
self._created_connections += 1
kwargs = dict(self.connection_kwargs)
if self.cache is not None:
return CacheProxyConnection(
self.connection_class(**kwargs), self.cache, self._lock
)
return self.connection_class(**kwargs)
def release(self, connection: "Connection") -> None:
"Releases the connection back to the pool"
self._checkpid()
with self._lock:
try:
self._in_use_connections.remove(connection)
except KeyError:
# Gracefully fail when a connection is returned to this pool
# that the pool doesn't actually own
return
if self.owns_connection(connection):
if connection.should_reconnect():
connection.disconnect()
self._available_connections.append(connection)
self._event_dispatcher.dispatch(
AfterConnectionReleasedEvent(connection)
)
else:
# Pool doesn't own this connection, do not add it back
# to the pool.
# The created connections count should not be changed,
# because the connection was not created by the pool.
connection.disconnect()
return
def owns_connection(self, connection: "Connection") -> int:
return connection.pid == self.pid
def disconnect(self, inuse_connections: bool = True) -> None:
"""
Disconnects connections in the pool
If ``inuse_connections`` is True, disconnect connections that are
currently in use, potentially by other threads. Otherwise only disconnect
connections that are idle in the pool.
"""
self._checkpid()
with self._lock:
if inuse_connections:
connections = chain(
self._available_connections, self._in_use_connections
)
else:
connections = self._available_connections
for connection in connections:
connection.disconnect()
def close(self) -> None:
"""Close the pool, disconnecting all connections"""
self.disconnect()
def set_retry(self, retry: Retry) -> None:
self.connection_kwargs.update({"retry": retry})
for conn in self._available_connections:
conn.retry = retry
for conn in self._in_use_connections:
conn.retry = retry
def re_auth_callback(self, token: TokenInterface):
with self._lock:
for conn in self._available_connections:
conn.retry.call_with_retry(
lambda: conn.send_command(
"AUTH", token.try_get("oid"), token.get_value()
),
lambda error: self._mock(error),
)
conn.retry.call_with_retry(
lambda: conn.read_response(), lambda error: self._mock(error)
)
for conn in self._in_use_connections:
conn.set_re_auth_token(token)
def _get_pool_lock(self):
return self._lock
def _get_free_connections(self):
with self._lock:
return self._available_connections
def _get_in_use_connections(self):
with self._lock:
return self._in_use_connections
async def _mock(self, error: RedisError):
"""
Dummy functions, needs to be passed as error callback to retry object.
:param error:
:return:
"""
pass
class BlockingConnectionPool(ConnectionPool):
"""
Thread-safe blocking connection pool::
>>> from redis.client import Redis
>>> client = Redis(connection_pool=BlockingConnectionPool())
It performs the same function as the default
:py:class:`~redis.ConnectionPool` implementation, in that,
it maintains a pool of reusable connections that can be shared by
multiple redis clients (safely across threads if required).
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:`~redis.ConnectionError` (as the default
:py:class:`~redis.ConnectionPool` implementation does), it
makes the client wait ("blocks") 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=50,
timeout=20,
connection_class=Connection,
queue_class=LifoQueue,
**connection_kwargs,
):
self.queue_class = queue_class
self.timeout = timeout
self._in_maintenance = False
self._locked = False
super().__init__(
connection_class=connection_class,
max_connections=max_connections,
**connection_kwargs,
)
def reset(self):
# Create and fill up a thread safe queue with ``None`` values.
try:
if self._in_maintenance:
self._lock.acquire()
self._locked = True
self.pool = self.queue_class(self.max_connections)
while True:
try:
self.pool.put_nowait(None)
except Full:
break
# Keep a list of actual connection instances so that we can
# disconnect them later.
self._connections = []
finally:
if self._locked:
try:
self._lock.release()
except Exception:
pass
self._locked = False
# this must be the last operation in this method. while reset() is
# called when holding _fork_lock, other threads in this process
# can call _checkpid() which compares self.pid and os.getpid() without
# holding any lock (for performance reasons). keeping this assignment
# as the last operation ensures that those other threads will also
# notice a pid difference and block waiting for the first thread to
# release _fork_lock. when each of these threads eventually acquire
# _fork_lock, they will notice that another thread already called
# reset() and they will immediately release _fork_lock and continue on.
self.pid = os.getpid()
def make_connection(self):
"Make a fresh connection."
try:
if self._in_maintenance:
self._lock.acquire()
self._locked = True
if self.cache is not None:
connection = CacheProxyConnection(
self.connection_class(**self.connection_kwargs),
self.cache,
self._lock,
)
else:
connection = self.connection_class(**self.connection_kwargs)
self._connections.append(connection)
return connection
finally:
if self._locked:
try:
self._lock.release()
except Exception:
pass
self._locked = False
@deprecated_args(
args_to_warn=["*"],
reason="Use get_connection() without args instead",
version="5.3.0",
)
def get_connection(self, command_name=None, *keys, **options):
"""
Get a connection, blocking for ``self.timeout`` until a connection
is available from the pool.
If the connection returned is ``None`` then creates a new connection.
Because we use a last-in first-out queue, the existing connections
(having been returned to the pool after the initial ``None`` values
were added) will be returned before ``None`` values. This means we only
create new connections when we need to, i.e.: the actual number of
connections will only increase in response to demand.
"""
# Make sure we haven't changed process.
self._checkpid()
# Try and get a connection from the pool. If one isn't available within
# self.timeout then raise a ``ConnectionError``.
connection = None
try:
if self._in_maintenance:
self._lock.acquire()
self._locked = True
try:
connection = self.pool.get(block=True, timeout=self.timeout)
except Empty:
# Note that this is not caught by the redis client and will be
# raised unless handled by application code. If you want never to
raise ConnectionError("No connection available.")
# If the ``connection`` is actually ``None`` then that's a cue to make
# a new connection to add to the pool.
if connection is None:
connection = self.make_connection()
finally:
if self._locked:
try:
self._lock.release()
except Exception:
pass
self._locked = False
try:
# ensure this connection is connected to Redis
connection.connect()
# 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.
try:
if connection.can_read():
raise ConnectionError("Connection has data")
except (ConnectionError, TimeoutError, OSError):
connection.disconnect()
connection.connect()
if connection.can_read():
raise ConnectionError("Connection not ready")
except BaseException:
# release the connection back to the pool so that we don't leak it
self.release(connection)
raise
return connection
def release(self, connection):
"Releases the connection back to the pool."
# Make sure we haven't changed process.
self._checkpid()
try:
if self._in_maintenance:
self._lock.acquire()
self._locked = True
if not self.owns_connection(connection):
# pool doesn't own this connection. do not add it back
# to the pool. instead add a None value which is a placeholder
# that will cause the pool to recreate the connection if
# its needed.
connection.disconnect()
self.pool.put_nowait(None)
return
if connection.should_reconnect():
connection.disconnect()
# Put the connection back into the pool.
try:
self.pool.put_nowait(connection)
except Full:
# perhaps the pool has been reset() after a fork? regardless,
# we don't want this connection
pass
finally:
if self._locked:
try:
self._lock.release()
except Exception:
pass
self._locked = False
def disconnect(self, inuse_connections: bool = True):
"Disconnects either all connections in the pool or just the free connections."
self._checkpid()
try:
if self._in_maintenance:
self._lock.acquire()
self._locked = True
if inuse_connections:
connections = self._connections
else:
connections = self._get_free_connections()
for connection in connections:
connection.disconnect()
finally:
if self._locked:
try:
self._lock.release()
except Exception:
pass
self._locked = False
def _get_free_connections(self):
with self._lock:
return {conn for conn in self.pool.queue if conn}
def _get_in_use_connections(self):
with self._lock:
# free connections
connections_in_queue = {conn for conn in self.pool.queue if conn}
# in self._connections we keep all created connections
# so the ones that are not in the queue are the in use ones
return {
conn for conn in self._connections if conn not in connections_in_queue
}
def set_in_maintenance(self, in_maintenance: bool):
"""
Sets a flag that this Blocking ConnectionPool is in maintenance mode.
This is used to prevent new connections from being created while we are in maintenance mode.
The pool will be in maintenance mode only when we are processing a MOVING notification.
"""
self._in_maintenance = in_maintenance
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