In this commit, we correct our size estimates for to-local scripts,
which are used on the commitment transaction and the htlc
success/timeout transactions. There have been observed cases of
transactions getting stuck because our estimates were too low, and cause
the transactions to not be relayed.
Our previous estimate for the commitment to-local script was derived
from an older version of the script. Though the estimate is greater than
the actual size, this has been updated with the current estimate of 79
bytes.
This estimates makes the assumption that CSV delays will be at most
4 bytes when serialized. Since this value is expressed in relative block
heights, this should be more than sufficient for our needs, even though
the maximum possible size for the little-endian int64 is 9 bytes (plus
an OP_DATA).
The other correction is to use the ToLocalScriptSize as our estimate for
htlc timeout/success scripts, as they are the same script. Previously,
our estimate was derived from the proper script, though we were 6 bytes
shy of the new to-local estimate, since we counted the csv_delay as 1
byte, and missed some other OP_DATAs.
All derived estimates have been updating depending on the new and
improved ToLocalScriptSize estimate, and fix some estimates that did not
include the witness length in the estimate.
Finally, we correct some weight miscalculations in:
- AcceptedHtlcTimeoutWitnessSize: missing data push lengths
- OfferedHtlcSuccessWitnessSize: extra 73 byte sig, missing data push lengths
- OfferedHtlcPenaltyWitnessSize: missing 33 byte pubkey
In this commit, we fix a slight race condition that can occur when we go
to add a shell node for a node announcement, but then right afterwards,
a new block arrives that causes us to prune an unconnected node. To
ensure this doesn't happen, we now add shell nodes within the same db
transaction as AddChannelEdge. This ensures that the state is fully
consistent and shell nodes will be added atomically along with the new
channel edge.
As a result of this change, we no longer need to add shell nodes within
the ChannelRouter, as the database will take care of this operation as
it should.
In this commit, we fix an existing bug in the pruneGraphNodes method.
Before this commit, if a node was involved in a channel, but only one of
the edges was advertised, then either it, or the other node would be
erroneously pruned from the graph. They shouldn't be pruned as there's
still an edge connecting the, although only 1/2 of the edge is actually
advertised.
In order to fix this, we'll now do two passes: the first pass will
populate a ref count map of all known nodes in the graph, the second
pass will increment the ref count each time a node is found in the
graph. With this two pass method, we ensure that nodes are only deleted
if there are absolutely no edges pointing to them within the graph.
In this commit, we extend the TestPruneGraphNodes test to also test the
case of when a node is involved in a channel, but only a single edge for
that channel has been advertised. In order to test this, we add an
additional node to the graph, and also a new channel. However, this
channel will only have a single edge advertised. As result, when we
prune the set of edges, the only node remaining should be the node that
didn't have any edges at all.
callbacks
The FindPeer and SendToPeer callbacks are no longer needed within the
fundingManager due to the previous commit allowing us to send messages
to peers directly.
In this commit, we modify the existing message sending functionality
within the fundingmanager. Due to each mesage send requiring to hold the
server's lock to retrieve the peer, we might run into a case where the
lock is held for a larger than usual amount of time and would therefore
block on sending the message within the fundingmanager. We remedy this
by taking a similar approach to some recent changes within the gossiper.
We now keep track of each peer within the internal fundingmanager
messages and send messages directly to them.
