This commit alters the behavior of the router's logic on
startup, ensuring that the chain view is filtered using
the router's latest prune height. Before, the chain was
filtered using the bestHeight variable, which was
uninitialized, benignly forcing a rescan from genesis.
In tracking down this, we realized that we should
actually be using the prune height, as this is
representative of the channel view loaded from disk.
The best height/hash are now only used during
startup to determine if we are out of sync.
In this commit we fix an existing bug within the ChannelRouter. Before
this commit, we would sync our graph prune state, *then* update the
cain filter. This is incorrect as the blocks we manually pruned may
have included channel closing transactions. As a result, we would miss
the pruning of a set of channels, and assume that they were still
active.
In this commit, we fix this by reversing the order: we first update the
chain filter and THEN sync the channel graph.
In this commit we add a new test to the set of unit tests for the
ChannelRouter: TestRouterChansClosedOfflinePruneGraph. This tests that
if channels are closed while the ChannelRouter is down, then upon
restart the channels are properly recognized as being closed.
In this commit, we add a Reset() method to the mockChainView struct.
With this new method tests are able to fully simulate a restart of the
ChannelRouter. This is necessary as the FilteredChainView instances are
assumed to be stateless, and don’t write their state to disk before a
restart.
This commit adds a test for the FilteredChainView interfaces,
making sure they notify about disconnected/connected blocks
in the correct order during a reorg.
This commit makes use of the blockEventQueue within the neutrino
implementation of FilteredChainView to ensure connected and
disconnected blocks are consumed in order by the reader.
It also specifies that neutrino is not to send disconnected blocks
notifications during rescans, making it consistent with the btcd
implementation.
This commit moves btcd view away from using the deprecated
callbacks onBlockConnected/Disconnected, and instead use
onFilteredBlockConnected/disconnected.
This commit also implements the sending of disconnected blocks
over the staleBlocks channel. To send these blocks, the
blockEventQueue is used to ensure the ordering of blocks are
correctly kept.
It also changes the way filter updates are handled. Since we
now load the tx filter to the rpc server itself, we can call
RescanBlocks instead of manually filtering blocks. These
rescanned blocks are also added to the blockEventQueue,
ensuring the ordering is kept.
blockEventQueue is an ordered queue for block events sent from a
FilteredChainView. The two types of possible block events are
connected/new blocks, and disconencted/stale blocks. The
blockEventQueue keeps the order of these events intact, while
still being non-blocking. This is important in order for the
chainView's call to onFilteredBlockConnected/Disconnected to not
get blocked, and for the consumer of the block events to always
get the events in the correct order.
Before this commit, we would expect that structurally we don’t pay any
fee for the first hop, but do for the final hop. After the latest
commit, this is now flipped as when we say fee, we mean the fee that we
need to pay to transit a link. For the final hop, there’s no additional
distance to be traveled, so the fee is nothing.
In this commit we fix an existing miscalculation in the fees that we
prescribe within the onion payloads for multi-hop routes. Before this
commit, if a route had more than 3 hops, then we would erroneously give
the second to last hop zero fees.
In this commit we correct this behavior, and also re-write the fee
calculation code fragment within newRoute for readability and clarity.
There are now only two cases: this is the last hop, and this is any
other hop. In the case of the last hop, simply send the exact amount
with no additional fee. In the case of an intermediate hop, we use the
_prior_ (closer to the destination) hop to calculate the amount of fees
we need, which allows us to compute the incoming flow. Using that
incoming flow, we then can compute the amount that the hop should
forward out.
Partially fixes#391.
In this commit we fix a slight bug within the existing SendPayment loop
which would cause the wrong error to be returned to users. Prior to
this commit, if we received an update identical to what we were already
aware of, then that error would be returned rather than the
ForwardingError that encapsulated this update.
In this commit with remedy this by properly returning the exact error.
Partially fixes#391.
In this commit we restore the in memory ChannelRouter as we’ll no
dynamically set the ChannelRouter’s pointer within he spec path finding
test example.
In this commit, we’ll now optionally allow the user to pass in the CLTV
delta value specified by the recipient a payment. If the value isn’t
specified, then we’ll use the current global default for the payment.
In this commit, we modify the FindRoutes method to pass in the CLTV
expiry for the final hop. If the value isn’t passed in, then we’ll use
the current global default value in place.
In this commit, we correct the fee calculation when converting from a
path to route. Previously we would apply the “no fee” case at the
_first_ hop, rather than the last hop. As a result, we needed to swap
the edges during path finding, otherwise, if the incoming and outgoing
edges had different fee rates, then we would create an invalid onion
payload.
In this commit we now properly switch fee calculation into three cases:
* a single hop route, so there’s no fee
* we’re at the first hop in a multi hop route, and we apply the fee
for the _next_ hop
* we’re at an intermediate hop and the fee calculation proceeds as
normal
In this commit we revert a commit which was added in the past as way to
allow the path -> route conversion code to remain the same, while
properly respecting the necessary time locks and fees. In an upcoming
change, this swap is no longer necessary as we’ll always use: the time
lock of the outgoing node and the fee of the incoming node.
In this commit, rather than reading the final CLTV delta from the
channel graph itself (which would require _both_ edges to be advertised
in order to route over), we now instead have moved to allowing the
receiving node to choose their own final CLTV delta.
In this commit, we’ve removed the selfNode attribute from memory, as
the set of new tests we’ll write, will depend on us being able to
switch the source node dynamically from the database itself.
In this commit, from the PoV of the SendPayment method we now delegate
all path finding+verification to missionControl. This change doesn’t
materially affect anything, it simply expands the abstraction to make
way for future features that more heavily utilize mission control.
In order to maintain the original essence of the test, we need to clear
the state of missionControl with each attempt, essentially advancing
time between each payment attempt.
In this commit we modify the SendPayment loop to optimize for
time-to-first-payment-success-or-failure. The prior logic would first
attempt to find at least 100 routes to the destination, then
iteratively prune them away as errors were encountered. In this commit,
we modify this approach to instead take a lazy approach: we first find
the current “best” path, attempt to send to that, and if an error
occurs we prune a section of the graph by reporting to missionControl,
then continue.
With this new approach, if the first known path has sufficient
capacity, and is available, then the payment speed is greatly improved
from the PoV of users. Additionally, we avoid the excessive computation
of crawling most of the graph in the k-shortest paths loop. With the
decay on missionControl, all routes will now feed information into the
central knowledge hung, allowing all payments to iteratively find out
the inactive portions of the payment graph.
This commit adds a new system within the ChannelRouter: missionControl.
The purpose of this system to is to act as a shared memory of sorts
between payment sending attempts, recording which edges/vertexes word
or didn’t work. Allowing execution attempts to pass on their iterative
knowledge of the graph to later attempts will reduce the number of
failures encountered, and generally lead to a better UX when sending
payments.
The current capabilities of missionControl are rather limited just to
introduce the new abstraction. Later follow up commits will also add
preferential treatment for reliable nodes, knowledge the impact that
target payments have on unbalancing the payment graph, etc.
This commit fixes a bug that could lead to a deadlock inside bolt db
itself. In a recent commit we allowed a db transaction to be passed
directly into findPath, however, the initial call to graph.ForEachNode
instead passed a _nil_ transaction causing the method itself to create
a _new_ transaction, leading to a deadlock.
We fix this issue by instead re-using the transaction pointer.
This commit modifies the path finding logic such that all path finding
is done inside a _single_ database transaction. With this change, we
ensure that we don’t end up possibly creating hundreds of database
transactions slowing down the path finding and payment sending process
all together.
