Fix compression (#2806)

[GUVWAF]

Fixes #2806.

The packet was encoded to protobufs before the decoded part was modified, so in protobufs encoding, still the old payload and portnum was used. Furthermore, while decompressing (which actually didn't happen because the portnum was not TEXT_MESSAGE_COMPRESSED_APP), the payload size wasn't modified.

Not sure if this has ever worked before, since there were no real changes in this part of the code since it was implemented.

[github-actions]

🤖 Pull request artifacts

file	commit
pr2819-firmware-2.2.8.4b522cc.zip	4b522cc

[kokroo]

@GUVWAF Mc-hamster did a great job integrating Unishox 2 but I guess all of us got mislead into thinking that compression is working, especially since Longfast has really short airtime. This bug became apparent only after I used VeryLongSlow.

Big thanks to you and @mc-hamster for working on compression!

I hope you were able to verify that compression actually works now? My long sample message which contained dozens of 'hello's should go across on VeryLongSlow in less than 8 seconds instead of 27 seconds. I'm currently far away from my laptop and civilisation so can't check it out myself unfortunately.

[GUVWAF]

Yes, confirmed on VeryLongSlow:

DEBUG | ??:??:?? 66 [SerialModule] Add packet record (id=0x00453f8b fr=0x00 to=0xff, WantAck=1, HopLim=3 Ch=0x0 Portnum=1)
DEBUG | ??:??:?? 66 [SerialModule] Length - 227, compressed length - 20
DEBUG | ??:??:?? 66 [SerialModule] Original message - Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello H
DEBUG | ??:??:?? 66 [SerialModule] Using compressed message.
DEBUG | ??:??:?? 66 [SerialModule] Expanding short PSK #1
DEBUG | ??:??:?? 66 [SerialModule] Using AES128 key!
DEBUG | ??:??:?? 66 [SerialModule] enqueuing for send (id=0x00453f8b fr=0x39 to=0xff, WantAck=0, HopLim=3 Ch=0x59 encrypted)
DEBUG | ??:??:?? 66 [SerialModule] txGood=2,rxGood=0,rxBad=0
DEBUG | ??:??:?? 66 [RadioIf] Starting low level send (id=0x00453f8b fr=0x39 to=0xff, WantAck=0, HopLim=3 Ch=0x59 encrypted priority=64)
DEBUG | ??:??:?? 66 [RadioIf] (bw=62, sf=12, cr=4/8) packet symLen=65 ms, payloadSize=40, time 6045 ms
DEBUG | ??:??:?? 66 [RadioIf] AirTime - Packet transmitted : 6045ms

[GUVWAF]

@kokroo FYI this has been reverted since it caused a breaking change with previous firmware versions (#2833). It will be added for the 3.0 release. It can be used though if you only use devices on 2.2.8.