Start tracking ChannelMonitors by channel ID in ChainMonitor and ChannelManager #3554
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
wpaulino
force-pushed
the
channel-monitor-by-channel-id
branch
2 times, most recently
from
40aeb66 to
1c7a0a1
Compare
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #3554 +/- ##
==========================================
- Coverage 88.54% 88.49% -0.05%
==========================================
Files 149 149
Lines 114459 114709 +250
Branches 114459 114709 +250
==========================================
+ Hits 101345 101517 +172
- Misses 10618 10691 +73
- Partials 2496 2501 +5 ☔ View full report in Codecov by Sentry. |
wpaulino
force-pushed
the
channel-monitor-by-channel-id
branch
from
1c7a0a1 to
850ec1b
Compare
jkczyz
reviewed
Jan 23, 2025
wpaulino
force-pushed
the
channel-monitor-by-channel-id
branch
from
850ec1b to
a24d821
Compare
TheBlueMatt
reviewed
Jan 24, 2025
wpaulino
force-pushed
the
channel-monitor-by-channel-id
branch
from
a24d821 to
5bcca97
Compare
|
Rebased due to conflicts and removed the last commit |
wpaulino
force-pushed
the
channel-monitor-by-channel-id
branch
from
5bcca97 to
c680c0f
Compare
jkczyz
previously approved these changes
Jan 29, 2025
TheBlueMatt
reviewed
Jan 31, 2025
Once dual funding/splicing is supported, channels will no longer maintain their original funding outpoint. Ideally, we identify `ChannelMonitor`s with a stable identifier, such as the channel ID, which is fixed throughout the channel's lifetime. This commit replaces the use of funding outpoints as the key to the monitor index with the channel ID. Note that this is strictly done to the in-memory state; it does not change how we track monitors within their persisted state, they are still keyed by their funding outpoint there. Addressing that is left for follow-up work.
As motivated by the previous commit, we do some of the same work here at the `ChannelManager` level instead. Unfortunately, we still need to track the funding outpoint to support downgrades by writing the in flight monitor updates as two separate TLVs, one using the channel IDs, and the other using the funding outpoints. Once we are willing to stop supporting downgrades past this version, we can fully drop it.
It's not needed except for one place where we can just access the field directly, so we can avoid the allocation on each call. For API consumers, they may still access the funding script via `ChannelMonitor::get_funding_script`.
wpaulino
force-pushed
the
channel-monitor-by-channel-id
branch
from
c680c0f to
717db82
Compare
TheBlueMatt
approved these changes
Jan 31, 2025
jkczyz
approved these changes
Jan 31, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Once dual funding/splicing is supported, channels will no longer maintain their original funding outpoint. Ideally, we identify
ChannelMonitors with a stable identifier, such as the channel ID, which is fixed throughout the channel's lifetime.In the
ChainMonitor, we replace the use of funding outpoints as the key to the monitor index with the channel ID. Note that this is strictly done to the in-memory state; it does not change how we track monitors within their persisted state, they are still keyed by their funding outpoint there. Addressing that is left for follow-up work.In the
ChannelManager, in-flight monitor updates are persisted, so we still need to track the funding outpoint to support downgrades by writing the in them as two separate TLVs, one using the channel IDs, and the other using the funding outpoints. Once we are willing to stop supporting downgrades past this version, we can fully drop the old TLV.Looking to get concept ACKs on whether we want to go down this path. The first two commits can be considered today, but the last one will have to wait a few releases due to the backwards compatibility concern. Note that this PR does not represent all of the work to achieve our goal, there's still a good bit of refactoring/cleanup to follow.