This commit modifies the path finding routines to properly use the new
channel edge related API exposed by the database. Additionally, a new
type `ChannelHop` has been introduced which couples an edges routing
policy with the capacity and origin chain of the channel.
This commit alters the return value of PrunedGraph to me a bit more
useful: the function now returns all the channels that were closed when
processing the block (slice of spent outpoints). With this information,
callers gain greater visibility into exactly which channels were
closed. This can be used in higher levels to present detailed summaries
of how blocks affect closed channels.
This commit splits the prior ChannelEdge struct into two distinct
structs: ChannelEdgeInfo and ChannelEdgePolicy. The info structs stores
the _full_ information that was used to advertise the channel, while
the policy struct contains the information that’s needed in order to
use the information for routing purposes.
With this split we can eliminate a number of hacks within the rest of
the codebase that were added as a result of data unavailability if one
or neither edge was present.
Finally a bit of field renaming has taken place (Exipiry ->
TimeLockDelta), etc.
This commit fixes a panic that would arise when the daemon attempts to
query for a channel that doesn’t currently exist. The bug was the
result of a typo which checked for the nil existence of the incorrect
variable.
This commit fixes a prior bug in the graph database due to an invalid
assumption that both channel edges would _always_ be advertised. This
assumption is invalid, as it’s up to a node’s policy if the advertise
their direction of the channel.
The fix for this assumption is straight forward: ErrEdgeNotFound is no
longer a critical error, instead a nil pointer will now be passed into
the passed callback function.
This commit makes a large number of minor changes concerning API usage
within the deamon to match the latest version on the upstream btcsuite
libraries.
The major changes are the switch from wire.ShaHash to chainhash.Hash,
and that wire.NewMsgTx() now takes a paramter indicating the version of
the transaction to be created.
This commit modifies the error propagating behavior within the
HasChannelEdge struct. Rather than exiting the function early when a
single edge isn’t found, we instead continue to also possibly retrieve
the second directional edge.
With this change, we avoid a potential infinite gossiping loop in the
routing package that would result if we’d seen one edge but not the
other. In this case the timestamps returned for *both* edges would
always be zero, causing the daemon to always accept and rebroadcast the
announcement putting all other connected lnd’s into the same loop.
This commit modifies the FetchChannelEdgesByID slightly to use a
read-only transaction rather than a write-only transaction. As a result
we’ll no longer extraneously consume a writer’s slot when we’re only
reading data from the database.
This commit modifies the HasChannelEdge function to _always_ return
true if we know of the channel edge, meaning that it was previously
added on announce.
This change fixes a minor bug present in the code which would result in
extraneous re-transmissions of updates received by the new routing
package.
This commit adds a utility method whcih utilizes the edge index bucket
and allows caller to look up the channel ID of a channel by its funding
outpoint. This can be used to populate RPC’s with additional
information and also to provide users with an additional query
interface to build channel explorers, etc.
This commit fixes a minor bug in the ForEachChannel method of the
ChannelGraph struct. Rather than ErrGraphNoEdgesFound being returned if
either of the edge related buckets hadn’t been created yet,
ErrGraphNodesNotFound was being returned.
To fix this bug, we now properly return ErrGraphNoEdgesFound.
Additionally a mental note to roasbeef has been left as the current
code currently assumes that eventually both directions of the channel
edge will be advertised. However, this may not necessarily be the case
in a live network, since a side chooses to preferentially advertise a
channel or not.
This commit adds to new functions to the ChannelGraph struct which
allow the callers to query for the existence or non-existence of a
vertex (node) or edge (channel) within the graph. In addition to
returning whether the edge exists, the functions will also return the
last time the state has been modified for the edge or vertex. This will
allow callers to ensure that only the most up to date state is
committed to disk.
This commit adds support for channel graph pruning, which is the method
used to keep the channel graph in sync with the current UTXO state. As
the channel graph is essentially simply a subset of the UTXO set, by
evaluating the channel graph with the set of outfits spent within a
block, then we’re able to prune channels that’ve been closed by
spending their funding outpoint. A new method `PruneGraph` has been
provided which implements the described functionality.
Upon start up any upper routing layers should sync forward in the chain
pruning the channel graph with each newly found block. In order to
facilitate such channel graph reconciliation a new method `PruneTip`
has been added which allows callers to query current pruning state of
the channel graph.
This commit modifies the LightningNode.ForEachChannel method to give
the caller the option of re-using an existing database transaction
instead of always creating a new db transaction with each invocation.
Internally boltdb will run into an error/dead-lock if a nested
transaction is attempted.
Such an action might be attempted if one were to use the traversal
functions in a path finding algorithm. Therefore in order to avoid
that after, we now allow the re-use of transactions to facilitate
nested calls to ForEachChannel.
This commit introduces a new capability to the database: storage of an
on-disk directed channel graph. The on-disk representation of the graph
within boltdb is essentially a modified adjacency list which separates
the storage of the edge’s existence and the storage of the edge
information itself.
The new objects provided within he ChannelGraph carry an API which
facilitates easy graph traversal via their ForEach* methods. As a
result, path finding algorithms will be able to be expressed in a
natural way using the range methods as a for-range language extension
within Go.
Additionally caching will likely be added either at this layer or the
layer above (the RoutingManager) in order keep queries and outgoing
payments speedy. In a future commit a new set of RPC’s to query the
state of a particular edge or node will also be added.
