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routing: disable FilteredChainView when AssumeChannelValid is active

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In this commit, we disable attempting to determine when a channel has
been closed out on-chain whenever AssumeChannelValid is active. Since
the flag indicates that performing this operation is expensive, we do
this as a temporary optimization until we can include proofs of channels
being closed in the gossip protocol.

With this change, the only way for channels being removed from the graph
will be once they're considered zombies: which can happen when both
edges of a channel have their disabled bits set or when both edges
haven't had an update within the past two weeks.
This commit is contained in:
Wilmer Paulino 2019-04-17 13:25:05 -07:00
parent 7e7b8a1940
commit fd1aa478a9
No known key found for this signature in database
GPG Key ID: 6DF57B9F9514972F
1 changed files with 81 additions and 63 deletions
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144
routing/router.go
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@ -200,8 +200,7 @@ type Config struct {
// AssumeChannelValid toggles whether or not the router will check for
// spentness of channel outpoints. For neutrino, this saves long rescans
// from blocking initial usage of the wallet. This should only be
// enabled on testnet.
// from blocking initial usage of the daemon.
AssumeChannelValid bool
}
@ -381,26 +380,15 @@ func (r *ChannelRouter) Start() error {
log.Tracef("Channel Router starting")
// First, we'll start the chain view instance (if it isn't already
// started).
if err := r.cfg.ChainView.Start(); err != nil {
return err
}
// Once the instance is active, we'll fetch the channel we'll receive
// notifications over.
r.newBlocks = r.cfg.ChainView.FilteredBlocks()
r.staleBlocks = r.cfg.ChainView.DisconnectedBlocks()
bestHash, bestHeight, err := r.cfg.Chain.GetBestBlock()
if err != nil {
return err
}
// If the graph has never been pruned, or hasn't fully been created yet,
// then we don't treat this as an explicit error.
if _, _, err := r.cfg.Graph.PruneTip(); err != nil {
switch {
// If the graph has never been pruned, or hasn't fully been
// created yet, then we don't treat this as an explicit error.
case err == channeldb.ErrGraphNeverPruned:
fallthrough
case err == channeldb.ErrGraphNotFound:
@ -418,37 +406,61 @@ func (r *ChannelRouter) Start() error {
}
}
// Before we perform our manual block pruning, we'll construct and
// apply a fresh chain filter to the active FilteredChainView instance.
// We do this before, as otherwise we may miss on-chain events as the
// filter hasn't properly been applied.
channelView, err := r.cfg.Graph.ChannelView()
if err != nil && err != channeldb.ErrGraphNoEdgesFound {
return err
}
log.Infof("Filtering chain using %v channels active", len(channelView))
if len(channelView) != 0 {
err = r.cfg.ChainView.UpdateFilter(
channelView, uint32(bestHeight),
)
if err != nil {
// If AssumeChannelValid is present, then we won't rely on pruning
// channels from the graph based on their spentness, but whether they
// are considered zombies or not.
if r.cfg.AssumeChannelValid {
if err := r.pruneZombieChans(); err != nil {
return err
}
} else {
// Otherwise, we'll use our filtered chain view to prune
// channels as soon as they are detected as spent on-chain.
if err := r.cfg.ChainView.Start(); err != nil {
return err
}
}
// Before we begin normal operation of the router, we first need to
// synchronize the channel graph to the latest state of the UTXO set.
if err := r.syncGraphWithChain(); err != nil {
return err
}
// Once the instance is active, we'll fetch the channel we'll
// receive notifications over.
r.newBlocks = r.cfg.ChainView.FilteredBlocks()
r.staleBlocks = r.cfg.ChainView.DisconnectedBlocks()
// Finally, before we proceed, we'll prune any unconnected nodes from
// the graph in order to ensure we maintain a tight graph of "useful"
// nodes.
err = r.cfg.Graph.PruneGraphNodes()
if err != nil && err != channeldb.ErrGraphNodesNotFound {
return err
// Before we perform our manual block pruning, we'll construct
// and apply a fresh chain filter to the active
// FilteredChainView instance. We do this before, as otherwise
// we may miss on-chain events as the filter hasn't properly
// been applied.
channelView, err := r.cfg.Graph.ChannelView()
if err != nil && err != channeldb.ErrGraphNoEdgesFound {
return err
}
log.Infof("Filtering chain using %v channels active",
len(channelView))
if len(channelView) != 0 {
err = r.cfg.ChainView.UpdateFilter(
channelView, uint32(bestHeight),
)
if err != nil {
return err
}
}
// Before we begin normal operation of the router, we first need
// to synchronize the channel graph to the latest state of the
// UTXO set.
if err := r.syncGraphWithChain(); err != nil {
return err
}
// Finally, before we proceed, we'll prune any unconnected nodes
// from the graph in order to ensure we maintain a tight graph
// of "useful" nodes.
err = r.cfg.Graph.PruneGraphNodes()
if err != nil && err != channeldb.ErrGraphNodesNotFound {
return err
}
}
r.wg.Add(1)
@ -465,10 +477,14 @@ func (r *ChannelRouter) Stop() error {
return nil
}
log.Infof("Channel Router shutting down")
log.Tracef("Channel Router shutting down")
if err := r.cfg.ChainView.Stop(); err != nil {
return err
// Our filtered chain view could've only been started if
// AssumeChannelValid isn't present.
if !r.cfg.AssumeChannelValid {
if err := r.cfg.ChainView.Stop(); err != nil {
return err
}
}
close(r.quit)
@ -562,9 +578,9 @@ func (r *ChannelRouter) syncGraphWithChain() error {
log.Infof("Syncing channel graph from height=%v (hash=%v) to height=%v "+
"(hash=%v)", pruneHeight, pruneHash, bestHeight, bestHash)
// If we're not yet caught up, then we'll walk forward in the chain in
// the chain pruning the channel graph with each new block in the chain
// that hasn't yet been consumed by the channel graph.
// If we're not yet caught up, then we'll walk forward in the chain
// pruning the channel graph with each new block that hasn't yet been
// consumed by the channel graph.
var numChansClosed uint32
for nextHeight := pruneHeight + 1; nextHeight <= uint32(bestHeight); nextHeight++ {
// Using the next height, request a manual block pruning from
@ -1121,21 +1137,23 @@ func (r *ChannelRouter) processUpdate(msg interface{}) error {
fundingPoint, msg.ChannelID, msg.Capacity)
// As a new edge has been added to the channel graph, we'll
// update the current UTXO filter within our active
// FilteredChainView so we are notified if/when this channel is
// closed.
filterUpdate := []channeldb.EdgePoint{
{
FundingPkScript: fundingPkScript,
OutPoint: *fundingPoint,
},
}
err = r.cfg.ChainView.UpdateFilter(
filterUpdate, atomic.LoadUint32(&r.bestHeight),
)
if err != nil {
return errors.Errorf("unable to update chain "+
"view: %v", err)
// update the current UTXO filter, if AssumeChannelValid is not
// present, within our active FilteredChainView so we are
// notified if/when this channel is closed.
if !r.cfg.AssumeChannelValid {
filterUpdate := []channeldb.EdgePoint{
{
FundingPkScript: fundingPkScript,
OutPoint: *fundingPoint,
},
}
err = r.cfg.ChainView.UpdateFilter(
filterUpdate, atomic.LoadUint32(&r.bestHeight),
)
if err != nil {
return errors.Errorf("unable to update chain "+
"view: %v", err)
}
}
case *channeldb.ChannelEdgePolicy: