The round was usable to build the current clock in an accumulated
fashion, relative to the previous round. The end time is the absolute
metric of it, which can be used to calculate the round number (with all
previous end times).
Substrate now builds off the best block, not genesis, using the end time
included in the justification to start its machine in a synchronized
state.
Knowing the end time of a round, or the round in which block was
committed to, is necessary for nodes to sync up with Tendermint.
Encoding it in the commit ensures it's long lasting and makes it readily
available, without the load of an entire transaction.
The machine reset to the end time of the current round. For a delayed
network connection, a machine may move ahead in rounds and only later
realize a prior round succeeded. Despite acknowledging that round's
success, it would maintain its delay when moving to the next block,
bricking it.
Done by tracking the end time for each round as they occur.
Substrate doesn't expect nor officially support children with less work
than their parents. It's a trick used here. Accordingly, ensure the
trick's validity.
By claiming File, they're not sent ovber the P2P network before they
have a justification, as desired. Unfortunately, they never were. This
works around that.
The BasicQueue returned obscures the TendermintImport struct.
Accordingly, a Future scoped with access is returned upwards, which when
awaited will create the machine. This makes creating the machine
optional while maintaining scope boundaries.
Is sufficient to create a 1-node net which produces and finalizes
blocks.
This shouldn't be used as a library AFAIK. While runtime should be, and
arguably should even be published, I have yet to see node in the same
way. Helps tighten API boundaries.
Not possible to be used as the previous consensus could. It will not
produce blocks nor does it currenly even instantiate a machine. This is
just he next step.
Multiple traits exist to verify/handle blocks. I'm unsure exactly when
each will be called in the pipeline, so the easiest solution is to have
every step run every check.
That would be extremely computationally expensive if we ran EVERY check,
yet we rely on Substrate for execution (and according checks), which are
limited to just the actual import function.
Since we're calling this code from many places, it makes sense for it to
be consolidated under TendermintImport.
Unfortunately, this immediately makes Tendermint machine capable of
deployment as crate since it uses a git reference. In the future, a
Cargo.toml patch section for serai/substrate should be investigated.
This is being done regardless as it's the quickest way forward and this
is for Serai.
