Blockchain's notificationDispatcher sends events to channels and these
channels must be read from. Unfortunately, regular service shutdown procedure
does unsubscription first (outside of the read loop) and only then drains the
channel. While it waits for unsubscription request to be accepted
notificationDispatcher can try pushing more data into the same channel which
will lead to a deadlock. Reading in the same method solves this, any number of
events can be pushed until unsub channel accepts the data.
Unfortunately Go doesn't allow to easily reuse readers in full packages, still
we can have this wrapper with a little overhead (the alternative is to move
specific methods into types of their own, but I'm not sure how it's going to
be accepted user-side).
Notice that int64 types are used for gas per block or registration price
because the price has to fit into the system fee limitation and gas per block
value can't be more than 10 GAS. We use int64 for votes as well in other types
since NEO is limited to 100M.
And test it with the RPC server.
Notice that getters still return int64 instead of *big.Int, that's because
these values are very limited and technically could even fit into an int (but
that seems to be too dangerous to use for long-term compatibility).
See neo-project/neo#2390. Can't see it there? No wonder, that's why we have
this bug for a year and a half. Not critical, we don't care about versions,
but _very_ annoying.
They were first introduced in a058598ecc and
then carefully moved in 648e0bb242, but it looks
like they were never used by any external code. This code can be useful on the
server, but the server has its own params package to deal with
parameters. Clients usually create Parameters and then get results as
stackitem.Items, so they don't use this code either. So there is zero point in
keeping it.
Which allows to enable/disable the service, change nodes, keys and other
settings. Unfortunately, atomic.Value doesn't allow Store(nil), so we have to
store a pointer there that can point to nil interface.
It's not an ideal solution, but at least it solves the problem for
now. Caveats:
* consensus only needs one method, so it's mirrored to Blockchain
* rpcsrv uses core.* definition of the StateRoot (so technically it might as
well not have an internal Ledger), but it uses core already unfortunately
1. It's not good for pkg/core to import anything from pkg/neorpc.
2. The type is closely tied to the state package, even though it's not stored
in the DB
It doesn't add anything useful to regular Go types and actually native types
are always better to use in the Client. Especially given that this type is
not used by any code outside of the Client itself.
