Mailbox should not constantly deserialize mesages.

[qnikst]

Current implementation of the CQueue and Match performs decoding on each check of the message, this is may be a huge performance hit for messages that are expensive to decentralize. We may implement solution that will memoise deserialization result.

We may use following approach:
Match could return 3 possible cases Matched a | Decoded b | NotMatch, where Matched a stands for match success, Decoded b stands for - fingerprint matches, but not message, in and deserialised value is returned, NotMatch stands for a case when fingerprint was not match or message is already decoded. Then CQueue implementation will alter CQueue and put decoded message instead of encoded.

It's possible to use Either a b instead where instead of NotMatch Left input will be returned, so queue will always be altered if message was not matched. However we need to check what approach will be cheaper.

CC: @dcoutts, @facundominguez.

[facundominguez]

Looks reasonable.

[hyperthunk]

+1 - sounds reasonable to me too.

[hyperthunk]

Looking at this, I want to understand decoded a bit better...

If we get a fingerprint match, we have to unencode (and that's coerce in the local case, don't forget), so that pattern matching or match-if can run. At that point if the match fails, Decoded b means we didn't match but we should update the queue record before continuing to search for a match, yes..?

So why does NoMatch stand for already decoded? That doesn't actually make sense to me...