class documentation

A ClientService maintains a single outgoing connection to a client endpoint, reconnecting after a configurable timeout when a connection fails, either before or after connecting.

Present Since
Method __init__ No summary
Method startService Start this ClientService, initiating the connection retry loop.
Method stopService Stop attempting to reconnect and close any existing connections.
Method whenConnected Retrieve the currently-connected Protocol, or the next one to connect.
Class Variable _log Undocumented
Instance Variable _machine Undocumented

Inherited from Service:

Method __getstate__ Undocumented
Method disownServiceParent Use this API to remove an IService from an IServiceCollection.
Method privilegedStartService Do preparation work for starting the service.
Method setName Set the name of the service.
Method setServiceParent Set the parent of the service. This method is responsible for setting the parent attribute on this service (the child service).
Instance Variable name A str which is the name of the service or None.
Instance Variable parent An IServiceCollection which is the parent or None.
Instance Variable running A boolean which indicates whether the service is running.
def __init__(self, endpoint, factory, retryPolicy=None, clock=None, prepareConnection=None): (source)
endpointA stream client endpoint provider which will be used to connect when the service starts.
factoryA protocol factory which will be used to create clients for the endpoint.
retryPolicy:callable taking (the number of failed connection attempts made in a row (int)) and returning the number of seconds to wait before making another attempt.A policy configuring how long ClientService will wait between attempts to connect to endpoint.
clock:IReactorTimeThe clock used to schedule reconnection. It's mainly useful to be parametrized in tests. If the factory is serialized, this attribute will not be serialized, and the default value (the reactor) will be restored when deserialized.

A single argument callable that may return a Deferred. It will be called once with the protocol each time a new connection is made. It may call methods on the protocol to prepare it for use (e.g. authenticate) or validate it (check its health).

The prepareConnection callable may raise an exception or return a Deferred which fails to reject the connection. A rejected connection is not used to fire an Deferred returned by whenConnected. Instead, ClientService handles the failure and continues as if the connection attempt were a failure (incrementing the counter passed to retryPolicy).

Deferreds returned by whenConnected will not fire until any Deferred returned by the prepareConnection callable fire. Otherwise its successful return value is consumed, but ignored.

Present Since Twisted 18.7.0

def startService(self): (source)

Start this ClientService, initiating the connection retry loop.

def stopService(self): (source)

Stop attempting to reconnect and close any existing connections.

a Deferred that fires when all outstanding connections are closed and all in-progress connection attempts halted.
def whenConnected(self, failAfterFailures=None): (source)

Retrieve the currently-connected Protocol, or the next one to connect.

failAfterFailures:int or Nonenumber of connection failures after which the Deferred will deliver a Failure (None means the Deferred will only fail if/when the service is stopped). Set this to 1 to make the very first connection failure signal an error. Use 2 to allow one failure but signal an error if the subsequent retry then fails.

Deferred that may:

a Deferred that fires with a protocol produced by the factory passed to __init__


_machine = (source)