This comes in the form of:
* Per listener maximum_qos option, which can be in the range 0-2.
* Changes to mosquitto_publish*() to return MOSQ_ERR_QOS_NOT_SUPPORTED
if attempting to publish with a higher QoS than supported.
* Bridges will downgrade messages to match the maximum QoS.
More tests on the broker side (specifically bridges) are required. This
needs bridge support for MQTT 5 first.
Limiting queued message depth purely based on message count is hard to
control for memory constrained devices. The size of messages can vary
wildly, from a few bytes, to a few kilobytes. Support a new
max_queued_bytes option, and drop packets when the first limit is
reached. Option defaults to 0 (disabled) by default.
Support also a max_inflight_bytes variable, with similar behaviour.
Fixes (partof) https://github.com/eclipse/mosquitto/issues/100
This pulls up some helper routines for calculating whether to allow
inflight or queuing, resolving some inconsistences in connection
resumption.
Signed-off-by: Karl Palsson <karlp@etactica.com>
Instead of simply tracking the count of stored messages, keep track of
the total byte size of stored messages. While only informational at
this point, it provides the basis for byte based limits in the future.
Signed-off-by: Karl Palsson <karlp@etactica.com>
Split message queue in two queues: in-flight and queued to avoid the
need to iterate over all messages.
Signed-off-by: Pierre Fersing <pierre.fersing@bleemeo.com>
This change in behaviour can be justified by considering when the
timeout may have occurred.
* If a connection is unreliable and has dropped, but without one end
noticing, the messages will be retried on reconnection. Sending
additional PUBLISH or PUBREL would not have changed anything.
* If a client is overloaded/unable to respond/has a slow connection then
sending additional PUBLISH or PUBREL would not help the client catch
up. Once the backlog has cleared the client will respond. If it is not
able to catch up, sending additional duplicates would not help either.
Roger A. Light
Tatsuzo Osawa
Karl Palsson
Pierre Fersing