readFrom method
Creates a payload from the specified header stream.
Implementation
@override
void readFrom(MqttByteBuffer payloadStream) {
var payloadBytesRead = 0;
final payloadLength = header!.messageSize - variableHeader!.length;
// Read all the topics and qos subscriptions from the message payload
while (payloadBytesRead < payloadLength) {
final topic = payloadStream.readMqttStringM();
final qos = MqttUtilities.getQosLevel(payloadStream.readByte());
payloadBytesRead +=
topic.length + 3; // +3 = Mqtt string length bytes + qos byte
addSubscription(topic, qos);
}
}