MQTT C Client Libraries Internals
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MQTTAsync_createOptions Struct Reference

Options for the MQTTAsync_createWithOptions call. More...

#include <MQTTAsync.h>

Data Fields

char struct_id [4]
 The eyecatcher for this structure.
 
int struct_version
 The version number of this structure.
 
int sendWhileDisconnected
 Whether to allow messages to be sent when the client library is not connected.
 
int maxBufferedMessages
 The maximum number of messages allowed to be buffered.
 
int MQTTVersion
 Whether the MQTT version is 3.1, 3.1.1, or 5.
 
int allowDisconnectedSendAtAnyTime
 Allow sending of messages while disconnected before a first successful connect.
 
int deleteOldestMessages
 
int restoreMessages
 
int persistQoS0
 

Detailed Description

Options for the MQTTAsync_createWithOptions call.

Field Documentation

◆ maxBufferedMessages

int MQTTAsync_createOptions::maxBufferedMessages

The maximum number of messages allowed to be buffered.

This is intended to be used to limit the number of messages queued while the client is not connected. It also applies when the client is connected, however, so has to be greater than 0.

◆ MQTTVersion

int MQTTAsync_createOptions::MQTTVersion

Whether the MQTT version is 3.1, 3.1.1, or 5.

To use V5, this must be set. MQTT V5 has to be chosen here, because during the create call the message persistence is initialized, and we want to know whether the format of any persisted messages is appropriate for the MQTT version we are going to connect with. Selecting 3.1 or 3.1.1 and attempting to read 5.0 persisted messages will result in an error on create.

◆ struct_id

char MQTTAsync_createOptions::struct_id[4]

The eyecatcher for this structure.

must be MQCO.

◆ struct_version

int MQTTAsync_createOptions::struct_version

The version number of this structure.

Must be 0, 1, 2 or 3 0 means no MQTTVersion 1 means no allowDisconnectedSendAtAnyTime, deleteOldestMessages, restoreMessages 2 means no persistQoS0


The documentation for this struct was generated from the following file: