For nodes with many channels this is a tremendous improvement in pay
performance. PR #7611 improves payment performance from 15 seconds to
13.5 seconds on one of our nodes. This commit improves payment
performance from 13.5 seconds to 5.7 seconds.
Changelog-Fixed: Improved pathfinding speed for large nodes.
Changelog-Added: pay: The pay plugin now checks whether we have enough spendable capacity before computing a route, returning a clear error message if we don't
is_local, ie. "is this side of the channel ours?" is not needed since we
can determine that predicate by evaluating
`scidd->dir == node_id_idx(self, peer)`
Add spendable/receivable and is_local fields to the callback function
used in gossmods_from_listpeerchannels. This allows to do more fine
grained use of the listpeerchannels call.
The first use case is renepay, for which we need to ignore the htlc_max
of the local channels only.
It's a u64, we should pass by copy. This is a big sweeping change,
but mainly mechanical (change one, compile, fix breakage, repeat).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Set up a simple line of channel pairs, where one should be preferred
over the other for our various reasons. Make sure this works, both
using a low-level call to Dijkstra and at a higher level as the pay
plugin does.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
