Skip to content

channeldb: split channel coordination from kv stores#10950

Draft
ziggie1984 wants to merge 125 commits into
lightningnetwork:masterfrom
ziggie1984:chanstate-openchannel-no-db
Draft

channeldb: split channel coordination from kv stores#10950
ziggie1984 wants to merge 125 commits into
lightningnetwork:masterfrom
ziggie1984:chanstate-openchannel-no-db

Conversation

@ziggie1984

Copy link
Copy Markdown
Collaborator

This PR builds on #10812 and separates the remaining cross-domain channel
storage responsibilities.

The main changes are:

  • move link-node persistence behind a new linknode package,
  • introduce channelcoord for operations that must update channel state and
    link-node metadata together,
  • keep channeldb.DB as the KV composition and migration root,
  • narrow consumers away from ChannelStateDB where they only need
    channel-state storage or lifecycle coordination.

This keeps the current KV migration path intact while making the
channel-state, link-node, and coordination boundaries explicit for future SQL
backends.

The PR is intentionally not adding SQL implementations yet. It only prepares
the storage boundaries so SQL can later provide separate channel-state,
link-node, and coordinator implementations without removing the KV migration
root.

Commit story

  • chanstate: finish kv store extraction
  • linknode: move store from channeldb
  • channelcoord: add kv coordinator
  • lnwallet: split channel lifecycle deps
  • contractcourt: split channel lifecycle deps
  • channelnotifier: narrow channel store dep
  • peer: narrow channel state dependency
  • htlcswitch: use split channel stores in tests
  • server: wire explicit channel stores

Validation

  • go test ./channelcoord ./chanstate ./channeldb ./linknode ./lnwallet ./lnwallet/test ./funding ./contractcourt ./channelnotifier ./peer ./htlcswitch . -run '^$'
  • make lint

ziggie1984 added 30 commits July 4, 2026 12:31
Move the small value types referenced by chanstate.Store out of
channeldb. This includes ChannelConfig, ChannelStatus,
ChannelCloseSummary, ChannelShell, ChanCount, and FinalHtlcInfo. Leave
aliases in channeldb so existing callers keep compiling while the
backend still lives there.

Parameterize the Store facets over the channel type and instantiate
current callers with *channeldb.OpenChannel. This removes the chanstate
-> channeldb import edge without moving OpenChannel yet, keeping the
first step reviewable and backend-neutral.
Move ChannelType and its flag helpers into chanstate while leaving
compatibility aliases in channeldb. This is a backend-neutral value
type and does not require moving any KV serialization logic.

Keep the full type documentation with the moved chanstate definition.
The channeldb aliases preserve the existing public surface while later
commits continue moving OpenChannel state out of the KV package.
Move the OpenChannel error definitions into chanstate and leave
channeldb aliases for existing callers. These errors describe channel
state behavior rather than a concrete KV bucket layout.

Keeping the aliases preserves the public channeldb API while later
commits move more OpenChannel state and receiver logic toward
chanstate.
Move the ShutdownInfo state type, constructor, and closer helper into
chanstate. The type describes channel shutdown state and is not tied to
the concrete KV backend.

Keep the TLV encode and decode helpers in channeldb for now, since
those functions describe the current persisted format. The channeldb
constructor remains as a compatibility wrapper.
Add a lifecycle facet to the chanstate Store contract for refresh,
confirmation, open-state, and SCID mutations. Implement the facet on
ChannelStateDB using the existing KV persistence code.

Update the matching OpenChannel receivers to call through the store
methods instead of reaching into the ChannelStateDB backend directly.
Also convert fullSync into a channeldb helper so that KV-specific code
is no longer an OpenChannel receiver.
Add a status facet to the chanstate Store contract for status bit
updates and data-loss commit point handling. Implement the facet on
ChannelStateDB using the existing persistence code.

Update the matching OpenChannel receivers to call through the store
methods. The broadcast path still uses a private channeldb helper until
its closing-transaction facet is introduced in a later commit.
Add shutdown and close-transaction facets to the chanstate Store
contract. These cover persisted shutdown info plus stored unilateral
and cooperative closing transactions.

Implement the facets on ChannelStateDB with the existing KV code and
update OpenChannel receivers to call through the store methods. The
backend-specific key selection remains private to channeldb.
Add pending-channel setup to the chanstate lifecycle store facet. This
covers the path that writes a new pending channel and records the
funding broadcast height.

Move the OpenChannel receiver to call through ChannelStateDB and pass
the backend explicitly into the channeldb sync helper. This keeps the
link-node persistence detail in channeldb while removing another direct
backend reference from OpenChannel.
Move ChannelCommitment and HTLC into chanstate so upcoming store facets
can name commitment state without importing channeldb.

Leave the KV serialization helpers in channeldb and keep aliases for
existing call sites. This preserves the current disk format and keeps
backend-specific persistence code out of chanstate for now.
Move LogUpdate into chanstate so commitment store interfaces can refer
to pending update state without importing channeldb.

Keep the log-update serialization helpers in channeldb. Those helpers
remain part of the existing KV disk format and can move with the KV
backend implementation later.
Add a commitment-focused store facet for updating local channel
commitment state. This lets OpenChannel call through the chanstate
store contract instead of reaching directly into the KV backend.

Keep the existing KV transaction body on ChannelStateDB for now. The
receiver still owns locking and in-memory state updates while the store
method owns persistence.
Move CommitDiff and its forwarding reference types into chanstate. This
lets the next commitment store facet name pending remote commitment
state without importing channeldb.

Keep forwarding package persistence and commit-diff serialization in
channeldb for now. The aliases preserve existing call sites while the
KV backend code remains in place.
Add the remote commitment-chain append method to the chanstate
commitment store facet.

Move the existing KV transaction body onto ChannelStateDB and have the
OpenChannel receiver call through the store. This removes another
direct backend dependency from OpenChannel while keeping KV persistence
code in channeldb.
Add read-side commitment lookup methods to the chanstate commitment
store facet.

Move the existing OpenChannel KV view transaction bodies onto
ChannelStateDB. Leave the OpenChannel receivers as store-call wrappers.
This removes three more direct backend references from the receiver
code without changing the persisted data format.
Add the next-revocation persistence method to the chanstate commitment
store facet.

Move the existing OpenChannel KV update body onto ChannelStateDB. The
OpenChannel receiver keeps the external locking behavior and delegates
persistence through the store interface.
Move FwdState, PkgFilter, and FwdPkg into chanstate with their existing
comments and helper methods.

Leave channeldb aliases for the moved value types and constructors so
current callers keep compiling. The KV forwarding package persistence
code stays in channeldb.
Add the commitment-tail advancement method to the chanstate commitment
store facet.

Move the existing AdvanceCommitChainTail KV transaction body onto
ChannelStateDB. The OpenChannel receiver now keeps locking and restored
channel checks before delegating persistence through the store.
Add a forwarding-package store facet to chanstate.Store.

Move the existing OpenChannel forwarding-package KV transaction bodies
onto ChannelStateDB. The OpenChannel receivers keep their locking
behavior and delegate package loading, acking, filtering, and removal
through the store.
Add commitment-height, latest-commitment, and remote revocation store
lookups to the chanstate commitment store facet.

Move the existing OpenChannel KV view transaction bodies onto
ChannelStateDB. This leaves the receivers as store-call wrappers while
keeping the persisted format and read behavior unchanged.
Move the remaining OpenChannel revocation-log KV reads onto
ChannelStateDB.

This keeps FindPreviousState and the unit-test tail-height helper as
OpenChannel wrappers. It removes direct backend access from the
receiver methods while leaving RevocationLog in channeldb for now.
Move the revocation-log value types and TLV serialization helpers into
chanstate.

Leave channeldb aliases and wrapper functions for the existing KV
persistence code and tests. Bucket keys, errors, and transaction
helpers stay in channeldb, so this commit only moves backend-neutral
state data.
Add FindPreviousState to the chanstate commitment store facet now that
RevocationLog is a chanstate value type.

This extends the store contract without changing runtime behavior. The
existing ChannelStateDB method already satisfies the new method.
Keep the revocation-log tail-height helper on ChannelStateDB instead of
the OpenChannel receiver.

The helper is only used by channeldb tests, so it should not become
part of the backend-independent chanstate store contract. The tests now
call the concrete helper directly.
Change OpenChannel.Db to the composed chanstate Store interface while
keeping the existing field name.

Tests that need raw channeldb access now assert the concrete test
backend explicitly instead of reaching through OpenChannel.Db. This
keeps backend setup out of the store contract.
Convert the KV-only OpenChannel helpers for TLV aux data and
borked-state lookup into package-level channeldb helpers.

This keeps serialization and bucket inspection code tied to the KV
backend while leaving the OpenChannel receiver set closer to the future
chanstate type.
Add transitional OpenChannel accessors for the channel status and
confirmed SCID fields used by KV store code.

These helpers keep the fields private while allowing channeldb backend
code to continue hydrating and serializing channel state after
OpenChannel moves to chanstate.
Remove the KV forwarding packager from OpenChannel and derive a
ChannelPackager inside the channeldb store methods that need one.

This keeps the backend-specific kvdb transaction helper in channeldb,
so the OpenChannel type no longer carries that dependency toward
chanstate.
Move the backend-neutral ChannelSnapshot value type into chanstate and
leave channeldb with a compatibility alias.

This keeps the future OpenChannel Snapshot receiver close to its return
type without changing existing channeldb callers.
Move the backend-neutral taproot shachain and verification nonce
helpers into chanstate with the thaw-height threshold they support.

Leave channeldb aliases for existing callers while OpenChannel and its
receiver methods are moved across the package boundary.
Add a transitional non-locking status predicate for channeldb store
code and use it from KV serialization helpers.

This avoids calling an unexported OpenChannel helper from channeldb
after the type moves into chanstate.
ziggie1984 added 24 commits July 4, 2026 12:32
Move the pending open-channel write into the chanstate KV store
implementation while keeping link-node creation in channeldb. Preserve
the existing transaction boundary used by pending channels and restores.
Fold the channel key and thaw-height helpers into the store files
that own them, instead of keeping separate kv files that do not
represent their own stores.

The open-channel keys and thaw-height helpers now live with
kv_open_channel, closed-channel bucket ownership lives with
kv_close_summary, and commitment/update keys live with kv_commitment.
Move the KV-backed ChannelSetupStore implementation onto the
chanstate KVStore. This includes both channel-opening state and initial
forwarding policy persistence, which together make up the setup store
facet.

Keep the channeldb ChannelStateDB methods as compatibility wrappers so
callers can continue using the old package while the concrete KV store
implementation moves by facet.
Move the KV-backed FinalHTLCStore implementation onto KVStore. The
ChannelStateDB methods keep compatibility wrappers while final HTLC
lookup and on-chain outcome writes now live with the final HTLC KV store
code.

Carry the store-final-resolution option into KVStore so the on-chain
outcome path keeps the existing opt-in behavior.
Move the KV-backed OpenChannelFwdPkgStore implementation onto
KVStore. ChannelStateDB keeps the existing wrapper methods, but now
delegates through the channelstate KV store instead of passing its
backend into package-level helpers.

This keeps forwarding package persistence grouped with the existing
kv_forwarding_package code while removing another direct backend use
from the channeldb compatibility layer.
Move the KV-backed OpenChannelShutdownStore methods onto KVStore.
ChannelStateDB keeps the existing compatibility methods, but shutdown
state now flows through the channelstate KV store rather than backend
helper functions.

The bucket-level shutdown codec helper stays in kv_shutdown because it
is still the local serialization primitive used by the store method.
Move the KV-backed OpenChannelCloseTxStore implementation onto
KVStore. ChannelStateDB keeps compatibility wrappers for marking and
fetching broadcast close transactions while the KV logic now lives in
kv_close_tx.

Keep the generic close transaction fetch helper private to KVStore and
expose only the domain methods required by the channelstate interface.
Move the KV-backed OpenChannelStatusStore implementation onto
KVStore. ChannelStateDB keeps compatibility wrappers while status
updates, data-loss commit point lookup, and borked marking now flow
through the channelstate KV store.

Keep the status write helper private to KVStore so related KV store
facets can share the same status mutation path without passing raw
backends around.
Move the backend-local open channel lifecycle mutations onto KVStore.
ChannelStateDB keeps compatibility wrappers for refreshing channel state
and marking confirmation, open, real scid, and scid-alias negotiation
state.

Leave SyncPendingChannel in channeldb for now because that path still
creates link-node records, and LinkNodeDB ownership remains in channeldb
for this refactor.
Move the KV-backed open channel commitment store methods onto
KVStore. ChannelStateDB keeps compatibility wrappers for commitment
updates, pending commit diffs, revocation queries, and previous-state
lookups.

Carry the no-rev-log-amount-data option into KVStore alongside the
existing final HTLC option so revocation log and final-resolution writes
preserve their previous configuration behavior.
Move the KV-backed revocation log tail helper onto KVStore. This
removes the last direct backend call from the channeldb open channel
compatibility methods while keeping the test-facing helper in place.
Move closed-channel summary reads and CloseChannel onto KVStore.
ChannelStateDB keeps compatibility wrappers, while the KV code for close
summary lookup and close archiving now lives with kv_close_summary.

Carry the tombstone-close option into KVStore so the existing close
strategy selection remains unchanged. Leave MarkChanFullyClosed and
AbandonChannel in channeldb because they still coordinate link-node
pruning and cross-store behavior.
Move historical channel bucket lookup and FetchHistoricalChannel onto
KVStore. The channeldb wrapper still attaches itself to channel.Db so
existing callers continue to receive a compatibility store reference.

Move ErrNoHistoricalBucket into chanstate and keep the channeldb error
as an alias, matching the other channel-state errors that have moved.
Move the KV-backed open channel read and scan methods onto KVStore.
ChannelStateDB keeps compatibility wrappers that attach themselves to
returned OpenChannel values so existing receiver methods still use the
channeldb store.

Leave restore and sync paths in channeldb because they still coordinate
link-node creation and repair while LinkNodeDB ownership remains outside
chanstate.
Move the KV-backed AbandonChannel implementation onto KVStore.
ChannelStateDB keeps a compatibility wrapper while callers still import
channeldb for the channel-state store.

Keep the link-node-coupled close and repair methods in channeldb so
the follow-up LinkNode store can define that boundary explicitly.
Move the remaining channel-state tests and helpers into the chanstate
package so the store owns the KV-specific behavior directly.

This also narrows the channel-state store interface by removing
cross-domain link-node lifecycle methods. Those workflows will be owned
by a separate channel coordinator in the next commits.
Move link-node persistence into its own package while keeping channeldb
aliases and wrappers for existing callers.

This creates an explicit linknode.Store boundary that can be wired
independently from channel-state persistence in later commits.
Add the channel coordination contract and a KV-backed implementation for
workflows that span channel-state and link-node storage.

The channeldb.DB type now constructs and exposes the coordinator while
remaining the legacy KV composition and migration root. ChannelStateDB
keeps compatibility wrappers that delegate to the coordinator.
Pass channel-state persistence and lifecycle coordination into the
wallet separately instead of routing both through ChannelStateDB.

Update the funding manager config and tests with the same split because
the funding flow constructs wallets and uses the same channel-state
surface.
Use channel-state store interfaces for ordinary channel reads and
closed-channel queries in the arbitrators.

Route lifecycle operations that also maintain link-node state through
channelcoord.ChannelLifecycle instead of the ChannelStateDB facade.
Accept only the open and closed channel store methods needed to hydrate
channel notification payloads.

This keeps the notifier on channel-state persistence without depending
on the full store surface.
Rename the peer channel persistence dependency to ChannelStateStore and
describe the exact channel-state surfaces it needs.

Test fixtures now write channels through the coordinator while channel
records keep only the channel-state store.
Update htlcswitch test channels to persist through channelcoord while
keeping channel records bound to chanstate.Store.

The tests retain access to the owning channeldb.DB separately for switch
construction and restart scenarios.
Keep channeldb.DB as the server's legacy KV and migration root, but
store the channel-state, coordinator, and link-node dependencies
separately on server.

Route RPC, restore, autopilot, and subserver setup through those
explicit fields so consumers no longer reach through ChannelStateDB for
mixed responsibilities.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Projects

Status: Backlog

Development

Successfully merging this pull request may close these issues.

2 participants