mirror of
https://github.com/lightningnetwork/lnd.git
synced 2025-04-03 01:18:59 +02:00
98d1482942
After joining the two forked chains, it is necessary to ensure they both agree on the same best hash before proceeding to UnsafeStart the notifier. This is because when the BitcoindClient starts, it retrieves its best known block then calls GetBlockHeaderVerbose on the hash of the retrieved block. This block could be a reorged block if JoinNodes has not completed sync. If it is the case that the best block retrieved has been reorged out of the chain, GetBlockHeaderVerbose errors because bitcoind sets the number of confirmations to -1 on reorged blocks, and the btcd rpc client panics when parsing a block whose number of confirmations is negative. This parsing error is expected to be fixed, and as a more permanent solution chain backends should ensure that the `best block` they retrieve during startup has not been reorged out of the chain.
chainntnfs
The chainntnfs package implements a set of interfaces which allow callers to receive notifications in response to specific on-chain events. The set of notifications available include:
- Notifications for each new block connected to the current best chain.
- Notifications once a
txidhas reached a specified number of confirmations. - Notifications once a target outpoint (
txid:index) has been spent.
These notifications are used within lnd in order to properly handle the
workflows for: channel funding, cooperative channel closures, forced channel
closures, channel contract breaches, sweeping time-locked outputs, and finally
pruning the channel graph.
This package is intentionally general enough to be applicable outside the
specific use cases within lnd outlined above. The current sole concrete
implementation of the ChainNotifier interface depends on btcd.
Installation and Updating
$ go get -u github.com/lightningnetwork/lnd/chainntnfs