482f05a3bc
In this commit, we extend the BitcoindNotifier to support registering scripts for spends notifications. Once the script has been detected as spent within the chain, a spend notification will be dispatched through the Spend channel of the SpendEvent returned upon registration. For scripts that have been spent in the past, the rescan logic has been modified to match on the script rather than the outpoint. This is done by re-deriving the script of the output a transaction input is spending and checking whether it matches ours. For scripts that are unspent, a request to the backend will be sent to alert the BitcoindNotifier of when the script was spent by a transaction. To make this request we encode the script as an address, as this is what the backend uses to detect the spend. The transaction will then be proxied through the txUpdates concurrent queue, which will hand it off to the underlying txNotifier and dispatch spend notifications to the relevant clients. Along the way, we also address an issue where we'd miss detecting that an outpoint/script has been spent in the future due to not receiving a historical dispatch request from the underlying txNotifier. To fix this, we ensure that we always request the backend to notify us of the spend once it detects it at tip, regardless of whether a historical rescan was detected or not. |
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|---|---|---|
| .. | ||
| bitcoindnotify | ||
| btcdnotify | ||
| neutrinonotify | ||
| height_hint_cache_test.go | ||
| height_hint_cache.go | ||
| interface_dev.go | ||
| interface_test.go | ||
| interface.go | ||
| log.go | ||
| README.md | ||
| test_utils.go | ||
| txnotifier_test.go | ||
| txnotifier.go | ||
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