Gossipsub partial messages — mixed-peer interop test + simulator scenario (step 10)#471
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lucassaldanha wants to merge 15 commits into
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Gossipsub partial messages — mixed-peer interop test + simulator scenario (step 10)#471lucassaldanha wants to merge 15 commits into
lucassaldanha wants to merge 15 commits into
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Captures the MVP scope, jvm-libp2p/client responsibility boundary, client-facing API, routing semantics, per-group lifecycle and DoS caps, and the implementation plan for the gossipsub partial-messages extension. Lands ahead of implementation so sub-issues of libp2p#435 can reference a stable design anchor.
Step 1 of the partial-messages extension: plumb SubOpts.requestsPartial / SubOpts.supportsSendingPartial through subscribe announcements in both directions, and track the per-peer-per-topic receive state. - AbstractRouter parses the flags with the spec-mandated coercion (supportsSendingPartial := requestsPartial || supportsSendingPartial) and zeroes them on subscribe=false. - New enqueueSubscribe hook unifies outbound subscribe enqueueing so GossipRouter can attach per-topic flags in a single override. - GossipRouter exposes setTopicPartialFlags(topic, ...) to configure flags advertised for a locally-subscribed topic, and stores inbound flags in a new PartialSubscriptionState (plain HashMap on the pubsub event loop). State is cleaned on peer disconnect, topic unsubscribe, and per-peer unsubscribe. - Outbound unsubscribe MUST NOT carry partial flags; enforced at the SubscriptionPart wire-build site. No routing behaviour changes yet. See docs/partial-messages.md §4.5, §5, §6.1 for context.
…t addSubscription overload
- `PartialSubscriptionWireTest`: route reads of `partialSubscriptionState`
through `submitOnEventThread { ... }.join()`. The state container is
not thread-safe; direct access from the JUnit thread races the event
loop and can surface as `ConcurrentModificationException` or stale
reads. Two helpers (`peerFlagsOnEventLoop`, `snapshotPartialStateOnEventLoop`)
establish the happens-before barrier.
- `RpcPartsQueue`: remove the 2-arg `addSubscription(topic, status)`
default overload. The remaining 4-arg abstract method is the single
source of truth; `addSubscribe` / `addUnsubscribe` remain the
convenience entry points.
- `PartialSubFlags.coerce(requestsPartial, supportsSendingPartial)`: single source of truth for the spec coercion rule `supportsSendingPartial := requestsPartial || supportsSendingPartial`. Used from `GossipRouter.setTopicPartialFlags` for the outbound side. AbstractRouter keeps the inline expression for the receive side to avoid a reverse layering dependency (pubsub -> gossip); a comment notes the rule is applied on both sides. - `PartialSubscriptionState.setPeerFlags`: document that passing `PartialSubFlags.NONE` (or any equivalent all-false flags) is treated as a removal. Makes the set-sometimes-deletes invariant explicit for readers. - `AbstractRouter.handleMessageSubscriptions`: add Kdoc now that the method is `protected open`. Documents the "call super" contract for overrides (GossipRouter relies on this to keep peersTopics and partialSubscriptionState in sync) and the flag-normalisation precondition.
…ure/partial-messages-support
Introduces the public partial-messages API surface and the internal state management layer required before any routing logic lands: Public API (io.libp2p.pubsub.gossip.partialmessages): - PartialMessagesHandler<PeerState> — onIncomingRpc + onEmitGossip; PartialMessagesPeerFeedback passed per-call (resolves open question from design doc §9) - PublishAction<PeerState> / PublishActionsFn<PeerState> - PartialMessagesPeerFeedback interface + FeedbackKind enum Internal state management: - GroupId — content-equality ByteArray wrapper for use as map key - GroupState<PeerState> — per-(topic,groupId) container with mutable TTL and app-opaque peerStates - PartialGroupStateStore<PeerState> — TTL countdown, GC on ttl≤0 or empty peerStates, DoS caps (255/topic, 8/topic/peer, matching go-libp2p defaults), onPeerDisconnected, onTopicUnsubscribed - PartialMessagesAdapter (internal interface) / PartialMessagesAdapterImpl<PeerState> — erases PeerState at the GossipRouter boundary via a single @Suppress("UNCHECKED_CAST") in the builder Wiring: - GossipRouterBuilder: partialMessagesHandler field; build-time error if PARTIAL_MESSAGES extension enabled without a handler - GossipRouter: internal var partialMessages: PartialMessagesAdapter? No routing changes in this step.
Replaces the stub in GossipRouter.processPartialMessageExtension with the full flow: drop RPCs missing topicID or groupID, then delegate to PartialMessagesAdapterImpl which gets-or-creates the GroupState (with DoS cap enforcement) and calls handler.onIncomingRpc with the live peerStates map.
Adds the outbound path for the partial-messages extension: - GossipRpcPartsQueue: addPartialMessage queues a PartialMessagePart; takeMerged caps at 1 per RPC (proto field is optional, not repeated). - PartialMessagesAdapter: publishPartial invokes the client's PublishActionsFn, enforces the spec MUST (omit partialMessage when peer supports but did not request), updates nextPeerState atomically, and calls back via enqueueFn. - GossipRouter: publishPartial looks up PeerHandler by PeerId, routes through GossipRpcPartsQueue (not a direct send), and flushes pending. - Gossip facade: publishPartial submits to the event thread and returns CompletableFuture<Unit>. Tests: PartialMessagesOutboundRpcTest (5 wire-level) and 6 new unit tests in PartialMessagesAdapterImplTest.
Exercises the full stack built in steps 1-4 — SubOpts flag plumbing, ControlExtensions handshake, inbound handler dispatch, group-state tracking, and outbound publishPartial — over real TCP/Noise/Mplex using a trivial ByteArray bitmap as PeerState. Four tests: - Unidirectional partial RPC (payload + metadata delivered to handler) - Bidirectional round-trip between two hosts - nextPeerState persisted and visible to subsequent decide() calls - Spec MUST: partialMessage omitted when peer supports but did not request Both hosts bind to port 0 to avoid conflicts with other tests.
Per §5.2 of the partial-messages spec: when we have requested partial messages for a topic T and a peer supports sending partial for T, skip IDONTWANT to that peer. Sending IDONTWANT is redundant — the peer is expected to deliver partial RPCs instead of full messages. Also extends PubsubProtocol.supportsIDontWant() to include Gossip_V_1_3, since v1.3 is a superset of v1.2 and both IDONTWANT and the Extensions control message must coexist for partial-message sessions.
Three one-line additions to GossipRouter that call the already-implemented PartialMessagesAdapter hooks at the right lifecycle points: - heartbeat() → partialMessages?.onHeartbeat() Decrements TTL on all live groups each heartbeat and garbage-collects groups whose TTL has reached zero or whose peerStates map is empty. - onPeerDisconnected() → partialMessages?.onPeerDisconnected(peer.peerId) Removes the disconnected peer from every group's peerStates; GCs groups that become empty as a result. - unsubscribe() → partialMessages?.onTopicUnsubscribed(topic) Drops all group state for the topic when we leave it. TTL is already reset on every publishPartial call via getOrCreateLocalGroup.
…rs (step 9) §5.3 of the partial-messages spec: during the gossipsub heartbeat lazy-push, peers where we support sending partial AND they requested partial are excluded from IHAVE targets. Instead, handler.onEmitGossip is invoked once per locally-initiated (topic, groupId) group with the collected partial peers so the client can drive per-part delivery via publishPartial. - Add onEmitGossip(topic, partialPeers) to PartialMessagesAdapter and implement it in PartialMessagesAdapterImpl: iterates locally-initiated groups for the topic and calls handler.onEmitGossip for each. - Modify GossipRouter.emitGossip: when the adapter is set and we advertise supportsSendingPartial for the topic, partition the selected gossip targets into fullPeers (IHAVE) and partialPeers (onEmitGossip). Only fullPeers receive IHAVE. - Add PartialMessagesEmitGossipTest covering: IHAVE suppression for partial peers, onEmitGossip invocation for locally-initiated groups, no call for peer-initiated groups, and fallback to normal IHAVE when extension is off or flags unset.
…es (step 10) Wire partial-messages support through SimGossipRouter/Builder so the simulator can create networks with both partial-capable and non-partial peers. New tests: - PartialMessagesMixedPeerTest: 3-node E2E test (A partial, B partial, C full-only) verifying full-message suppression for partial peers, partial RPC delivery, and that non-partial senders still reach partial-capable peers unconditionally. - PartialMessagesSimTest: simulator scenario with a 4-peer star topology confirming full-message suppression and non-partial propagation in the gossip mesh. Refactoring: - GossipRouterBuilder: move router.partialMessages assignment from createGossipRouter() to build() so subclasses inherit the wiring without duplicating it; expose buildGossipExtensionsConfig() as protected. - SimGossipRouter: accept gossipExtensionsConfig as constructor parameter (defaults to GossipExtensionsConfig() for backward compatibility). - SimGossipRouterBuilder: pass buildGossipExtensionsConfig() to SimGossipRouter.
lucassaldanha
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Summary
Implements Step 10 of the partial-messages implementation plan
(
docs/partial-messages.md§8): a mixed-peer interop test and a simulatorscenario for networks that include both partial-capable and non-partial nodes on
the same topic.
Changes
Simulator wiring (prerequisite for the simulator scenario):
GossipRouterBuilder: moverouter.partialMessagesassignment fromcreateGossipRouter()intobuild()so subclasses (SimGossipRouterBuilder)inherit the partial-messages adapter wiring automatically; expose
buildGossipExtensionsConfig()asprotected.SimGossipRouter: acceptgossipExtensionsConfigas a constructor parameter(defaults to
GossipExtensionsConfig()— backward compatible).SimGossipRouterBuilder: thread the config through toSimGossipRouter.New tests:
PartialMessagesMixedPeerTest— three real libp2p hosts (A partial, B partial,C full-only) over TCP/Noise/Mplex:
PartialMessagesSimTest— four-peer star simulator with peers 0–1 partial and2–3 non-partial, exercising:
suppressed
is suppressed by the hub's
broadcastInboundTest plan
./gradlew :libp2p:test --tests "io.libp2p.pubsub.gossip.extensions.*"— all pass./gradlew :tools:simulator:test --tests "io.libp2p.simulate.gossip.*"— all pass./gradlew spotlessApply— no formatting changes needed