If the node is to start with seeds unavailable it will try connecting to each
of them three times, blacklist them and then sit forever waiting for
something. It's not a good behavior, it should always try connecting to seeds
if nothing else works.
Now we have VerifyTx() and PoolTx() APIs that either verify transaction in
isolation or verify it against the mempool (either the primary one or the one
given) and then add it there. There is no possibility to check against the
mempool, but not add a transaction to it, but I doubt we really need it.
It allows to remove some duplication between old PoolTx and verifyTx where
they both tried to check transaction against mempool (verifying first and then
adding it). It also saves us utility token balance check because it's done by
the mempool anyway and we no longer need to do that explicitly in verifyTx.
It makes AddBlock() and verifyBlock() transaction's checks more correct,
because previously they could miss that even though sender S has enough
balance to pay for A, B or C, he can't pay for all of them.
Caveats:
* consensus is running concurrently to other processes, so things could
change while verifyBlock() is iterating over transactions, this will be
mitigated in subsequent commits
Improves TPS value for single node by at least 11%.
Fixes#667, fixes#668.
GetBlockByIndex handler starts sending blocks right from the start index and
if that index is s.chain.BlockHeight() then we're requesting and receiving a
block we already have.
Turns out, C# node no longer broadcasts an Inv when it's creating a block,
instead it sends a ping and if we're not paying attention to the height
specified there we're technically missing a new block. Of course we'll get it
later after ping timer expiration and regular ping/pong sequence, but that's
delaying it for no good reason.
It no longer depends on blockchain state and there can't ever be an error, in
fact we can always iterate over signers, so copying these hashes doesn't make
much sense at all as well as sorting arrays in verifyTxWitnesses (witnesses
order must match signers order).
It's not needed any more with Go 1.13 as we have wrapping/unwrapping in base
packages. All errors.Wrap calls are replaced with fmt.Errorf, some strings are
improved along the way.
Closes#1192
1. We now have CMDGetBlockByIndex, so there's no need to request headers
first when we can just ask for blocks.
2. We don't ask for headers (i.e. we don't send CMDGetHeaders),
consequently, we shouldn't react on CMDHeaders.
3. But we still keep on reacting on CMDGetHeaders command as
there could be a node which needs headers.
