Extend server client ResetStatistics() to reset all client statistics not only channel...

[damikun]

Currently the class MqttClientStatus => ResetStatistics() resets only channel related stats (BytesSent and BytesReceived) but object itself contains more statistic values..

The pull request extend behaviour to reset all contained statistic as SentPacketsCount,ReceivedPacketsCount, SentApplicationMessagesCount, ReceivedApplicationMessagesCount

So if you call ResetStatistics(); all stats for particular client gets reseted from its stat object....

Original MqttClientStatus object...

    public sealed class MqttClientStatus
    {
        public MqttClientStatus(MqttClient client);

        public MqttSessionStatus Session { get; set; }
        public long SentPacketsCount { get; }
        public long ReceivedPacketsCount { get; }
        public long SentApplicationMessagesCount { get; }
        public long ReceivedApplicationMessagesCount { get; }
        public DateTime LastNonKeepAlivePacketReceivedTimestamp { get; }
        public long BytesSent { get; }
        public DateTime LastPacketSentTimestamp { get; }
        public DateTime ConnectedTimestamp { get; }
        public MqttProtocolVersion ProtocolVersion { get; }
        public string Endpoint { get; }

        public string Id { get; }
        public DateTime LastPacketReceivedTimestamp { get; }
        public long BytesReceived { get; }

        public Task DisconnectAsync();
        public void ResetStatistics();
    }

[dnfadmin]

All CLA requirements met.

[gfoidl]

Should these be set to 1?
I'm asking because of

MQTTnet/Source/MQTTnet/Server/Internal/MqttClientStatistics.cs

Lines 13 to 17 in e88b280

	// Start with 1 because the CONNACK packet is not counted here.
	long _receivedPacketsCount = 1;
	// Start with 1 because the CONNECT packet is not counted here.
	long _sentPacketsCount = 1;

BTW: there should be a space after the ,.

[chkr1011]

In my opinion 0 is fine because the user wants so to reset the entire statistics. The initial 1 is required to have correct values directly after start.

[damikun]

Yeah as @chkr1011 said this is user reset.. 1 is only on init when client open connection...

[gfoidl]

Personally I'd structure it like done in #1590 with an extra struct to hold the values.
And use Volatile.Read/Write instead of Interlocked.Exchange -- see PR for reason.

[damikun]

Will have a look and update... Inpull i just fit what was used in lib sources...

[chkr1011]

I will merge the pull request because it fixes the bug in the first place. We can then discuss how it is done and how to optimize it in your pull request.

[chkr1011]

Thank you for your contribution. Good work 👍