Bootstrap server binding read-message in a single read_exact

[Ben-PH]

This allows the bootstrap server to perform a complete read in one go, without incremental consumption of the stream (...internally, read_exact is an incremental read, but sorting that out is another issue. This statement assumes read_exact functions non-incrementally)

This allows state-changes in the server to be complete: The server consumes a message completely, or not at all.

• document all added functions
• try in sandbox /simulation/labnet
• unit tests on the added/changed features
  • make tests compile
  • make tests pass
• add logs allowing easy debugging in case the changes caused problems
• if the API has changed, update the API specification

[AurelienFT]

I don't really understand why you changed one read_exact with a peek and not the others to read bigger after. Even with the comment this change is unclear to me

EDIT: Ok I see, it's to say atomic on the read

[Ben-PH]

EDIT: Ok I see, it's to say atomic on the read

That's the idea. If for whatever reason, the attempt to get the next message fails halfway through (in the case of this change, after the stream is peeked, but before the read_exact occurs), the stream is unchanged.

In an ideal world, the state of the data in the stream only changes if the state of the server changes, and that state change is a before/after. No "during".