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MessageSender Class

  • Reference

A Message Sender that opens its own exclsuive Link on an existing Session.

Inheritance
builtins.object
MessageSender

Constructor

MessageSender(session, source, target, name=None, send_settle_mode=SenderSettleMode.Unsettled, receive_settle_mode=ReceiverSettleMode.PeekLock, max_message_size=1048576, link_credit=None, properties=None, error_policy=None, debug=False, encoding='UTF-8', desired_capabilities=None)

Parameters

Name Description
session
Required
Session

The underlying Session with which to send.
source
Required
str or bytes

The name of source (i.e. the client).
target
Required
Target

The AMQP endpoint to send to.
name
str or bytes

A unique name for the sender. If not specified a GUID will be used.

Default value: None
send_settle_mode
SenderSettleMode

The mode by which to settle message send operations. If set to Unsettled, the client will wait for a confirmation from the service that the message was successfully sent. If set to 'Settled', the client will not wait for confirmation and assume success.

Default value: SenderSettleMode.Unsettled
receive_settle_mode
ReceiverSettleMode

The mode by which to settle message receive operations. If set to PeekLock, the receiver will lock a message once received until the client accepts or rejects the message. If set to ReceiveAndDelete, the service will assume successful receipt of the message and clear it from the queue. The default is PeekLock.

Default value: ReceiverSettleMode.PeekLock
desired_capabilities
AMQPValue

The extension capabilities desired from the peer endpoint. To create a desired_capabilities object, please do as follows:

    1. Create an array of desired capability symbols: capabilities_symbol_array = [types.AMQPSymbol(string)]
    1. Transform the array to AMQPValue object: utils.data_factory(types.AMQPArray(capabilities_symbol_array))
Default value: None
max_message_size
int

The maximum allowed message size negotiated for the Link.

Default value: 1048576
link_credit
int

The sender Link credit that determines how many messages the Link will attempt to handle per connection iteration.

Default value: None
properties
dict

Metadata to be sent in the Link ATTACH frame.

Default value: None
error_policy
ErrorPolicy

A policy for parsing errors on link, connection and message disposition to determine whether the error should be retryable.

Default value: None
debug
bool

Whether to turn on network trace logs. If True, trace logs will be logged at INFO level. Default is False.

Default value: False
encoding
str

The encoding to use for parameters supplied as strings. Default is 'UTF-8'

Default value: UTF-8

Variables

Name Description
send_settle_mode
SenderSettleMode

The mode by which to settle message send operations. If set to Unsettled, the client will wait for a confirmation from the service that the message was successfully send. If set to 'Settled', the client will not wait for confirmation and assume success.
receive_settle_mode
ReceiverSettleMode

The mode by which to settle message receive operations. If set to PeekLock, the receiver will lock a message once received until the client accepts or rejects the message. If set to ReceiveAndDelete, the service will assume successful receipt of the message and clear it from the queue. The default is PeekLock.
max_message_size
int

The maximum allowed message size negotiated for the Link.

Methods

close

Close the sender, leaving the link intact.
destroy

Close both the Sender and the Link. Clean up any C objects.
get_state

Get the state of the MessageSender and its underlying Link.
on_state_changed

Callback called whenever the underlying Sender undergoes a change of state. This function can be overridden.
open

Open the MessageSender in order to start processing messages.
send

Add a single message to the internal pending queue to be processed by the Connection without waiting for it to be sent.
work

Update the link status.

close

Close the sender, leaving the link intact.

close()

destroy

Close both the Sender and the Link. Clean up any C objects.

destroy()

get_state

Get the state of the MessageSender and its underlying Link.

get_state()

Returns

Type Description
MessageSenderState

on_state_changed

Callback called whenever the underlying Sender undergoes a change of state. This function can be overridden.

on_state_changed(previous_state, new_state)

Parameters

Name Description
previous_state
Required
MessageSenderState

The previous Sender state.
new_state
Required
MessageSenderState

The new Sender state.

open

Open the MessageSender in order to start processing messages.

open()

Exceptions

Type Description
uamqp.errors.AMQPConnectionError if the Sender raisesan error on opening. This can happen if the target URI is invalidor the credentials are rejected.

send

Add a single message to the internal pending queue to be processed by the Connection without waiting for it to be sent.

send(message, callback, timeout=0)

Parameters

Name Description
message
Required
Message

The message to send.
callback
Required
callable[Message, MessageSendResult, MessageException]

The callback to be run once a disposition is received in receipt of the message. The callback must take three arguments, the message, the send result and the optional delivery condition (exception).
timeout

An expiry time for the message added to the queue. If the message is not sent within this timeout it will be discarded with an error state. If set to 0, the message will not expire. The default is 0.

Default value: 0

work

Update the link status.

work()

Attributes

max_message_size

receive_settle_mode

send_settle_mode