Peter M. Groen / FlashMQ

Firefox worked without it. Chrome didn't.

One part is a fix, where the frame was advertised to be bigger than it
was.

The other change is making it possible to send chunks larger than the
initial buffer size, by resizing the buffer (and resetting it later).

We interpret the close frames as closed transport, and therefore set
'error' to 'disconnected'. See code comments.

MQTT-3.8.3-3

MQTT-3.6.1-1

This fixes dpkg errors on removal.

Mandatory normative statement MQTT-3.1.2-6.

[MQTT-2.3.1-1]

When there are many sessions, the copying action can actually take some
time, and memory. A vector is faster and uses (a little) less memory.

This is a theoretical fix, without benchmarks to support it.

The only mutable session data of a client is QoS related, so when we're
copying sessions (for saving them), we need to lock the QoS data,
because that gets modified from active client traffic in worker threads.

Note: not super well tested at this point, nor was I ever able to
trigger actual errors despite long stress testing, so it's a theoretical
fix.

Empty leaves weren't removed, causing increase in memory use.

This method incurs no extra CPU load when messages aren't dropped.

One was confirmed: writing an mqtt packet into a client that
disconnected after checking the weak pointer for validity.

The rest made sense to change as well.

I have no explanation for it, but it happens (with QMQTT, should it
matter).

It was a mistake that it ran inside the timer thread, which came to
light by asserting the thread local authentication pointer (see a few
commits ago).

There were bugs in which authentication object was used when, causing
threadings bugs. Instead of getting from the 'sender', we can just store
a thread local pointer.

Files are simple serialized bytes prefaced by lengths. File is hashed to
verify integrity. This was also a good way preventing unexpected errors
when trying to crash the parser by having it load a different file.

This change includes some refactoring that was necessary:

- It 'fixes' looking at the wrong thread's authentiction. This is still
  wrong though. It will be fixed by a thread local pointer in the next
  commit.
- Deadlocks with yourself are handled in rwlockguard.
- QoSPacketQueue is now a class.
- Probably other tweaks.

It didn't clean up the old ones, causing unpredictable problems.

This fixes side effects when system time changes.