Add DispatchResult::Once|Stream enum and Dispatcher::dispatch() that branches
on the registered op_type (ADR-049 §6): Query/Mutation → invoke() (unchanged
Once path), Subscription → invoke_streaming() (Stream path). handle_stream
matches on DispatchResult: the Once path writes one call.responded/call.error
frame (no call.completed); the Stream path pumps each ResponseEnvelope to the
wire via pump_stream (ResponseEnvelope.into() → call.responded for Ok,
call.error for Err), then writes call.completed on natural stream end. An Err
envelope is terminal — last_was_error suppresses call.completed after an error.
The streaming branch clears context.deadline to None (subscriptions are
unbounded — ADR-049 §6, call-protocol Timeouts). Abort (ADR-016) needs no new
code: handle_abort removes the pending entry and dropping the pump task
releases handler resources via Drop. dispatch_requested delegates to dispatch
for backward compatibility with existing callers.
Add the foundational types for ADR-049 streaming handlers:
- StreamingHandler, ResponseStream type aliases and HandlerKind enum
(Once | Stream) in registration.rs, with make_streaming_handler() helper
- CallError::invalid_operation_type() in wire.rs (sixth protocol code,
retryable: false)
- HandlerRegistration.handler flipped from Handler to HandlerKind;
HandlerRegistration::new() now takes HandlerKind
- OperationRegistryBuilder absorbs wrapping: with_local/with_leaf/
with_leaf_provenance wrap raw Handler in HandlerKind::Once for
Query/Mutation; new with_local_streaming/with_leaf_streaming take a
StreamingHandler and wrap in HandlerKind::Stream for Subscription.
Builder validates kind matches spec.op_type (mismatch = startup error)
- OperationRegistry::register() returns Result<(), String> with a clear
mismatch message; all call sites updated to handle the Result
- invoke() matches on HandlerKind: Once -> existing path; Stream ->
INVALID_OPERATION_TYPE error envelope (guards against silent
truncation; invoke_streaming() added in a downstream task)
- OverlayOperationEnv::invoke_with_policy matches on HandlerKind:
Once -> dispatch; Stream -> INVALID_OPERATION_TYPE (composition is
request/response-only)
- Migrated every HandlerRegistration::new() construction site (~95)
to wrap raw Handler in HandlerKind::Once(handler); the builder sites
are handled by the builder-absorbs-wrapping change
- Updated two websocket subscription tests that relied on Subscription
ops dispatching via invoke() to expect INVALID_OPERATION_TYPE
- Added unit tests for invoke/register validation and
make_streaming_handler
Make Dispatcher::dispatch_requested pub and extract abort-cascade handling
into a pub handle_abort method so the WebSocket handler can feed deserialized
EventEnvelopes directly to the shared Dispatcher without a QUIC Connection.
CallConnection gains a new_overlay_only(identity) constructor (Option A) that
holds the Layer 2 overlay, PendingRequestMap, and resolved bearer Identity
without a QUIC Connection; identity() reads the stored field for the non-QUIC
case. compose_root_env uses the new identity() accessor for both paths.
The existing QUIC path (CallAdapter, CallClient, run_loop, handle_stream) is
unchanged — outgoing client methods guard on connection().is_none().
The #1 gap in alknet-call: the outbound connection opener. Every downstream
consumer (runner, container service, bilateral exchange, NAPI, agent
cross-node dispatch) is blocked on it.
Shared dispatch loop (ADR-017 §1 — the architectural commitment that keeps
CallClient from becoming a parallel protocol implementation):
- Extracts the accept-path dispatch (sweeper, accept_bi loop, handle_stream,
dispatch_requested, build_root_context, compose_root_env, fail_all on
close) out of CallAdapter into a new protocol/dispatch.rs Dispatcher struct.
Both CallAdapter::handle and CallClient::connect produce a CallConnection
and hand it to Dispatcher::run_loop — the loop is genuinely shared
(refactored, not duplicated).
- CallAdapter keeps its public API and test-facing wrappers (pub(crate),
#[cfg(test)]-gated) that delegate to the Dispatcher.
Peer-scoped default-deny (ADR-028 — the one-way-door security dimension):
- RemoteFilter { trusted_peer: bool } on the Dispatcher. In default-deny
mode (CallClient::new), an incoming call to an op with remote_safe: false
returns NOT_FOUND *before* any capability material reaches the handler —
a remote peer's call must not populate OperationContext.capabilities from
the local registration bundle unless the op is explicitly remote-safe
(ADR-028 Context). Trusted-peer mode (CallClient::trusted_peer, explicit
opt-in) bypasses the filter.
- The accept path (CallAdapter) uses RemoteFilter::trusted() by convention: a
direct QUIC client is not a filtered CallClient peer in the ADR-028 sense.
- OperationRegistry::list_operations_peer_scoped(trusted_peer) +
services_list_handler_peer_scoped for the CallClient's services/list
serving path (ADR-028 Assumption 2: a peer should not see ops it cannot
call, so discovery and dispatch filters agree).
CallClient (src/client/call_client.rs):
- CallClient { registry, identity_provider, trusted_peer: bool }.
- new() default-deny; trusted_peer() explicit opt-in (ADR-028 §3).
- connect(addr, CallCredentials) dials QUIC on ALPN alknet/call (quinn
feature), spawns Dispatcher::run_loop, returns a live CallConnection.
- spawn_dispatch(connection) shared path for connect + tests.
- CallCredentials { tls_identity, auth_token, remote_identity } — all from
Capabilities (ADR-014), never env vars (no-env-vars invariant). v1
connects without client-auth TLS identity (server uses
AcceptAnyCertVerifier); RawKey client-auth is a two-way-door remainder.
- RemoteIdentity { fingerprint } — concrete shape is a two-way door (OQ-25
remainder); the one-way constraint is it comes from Capabilities.
- ClientError { Transport, TlsSetup, ConnectionClosed }.
- CallConnection is now Clone (shares the inner Arcs) so connect can hand
the caller a live clone while the dispatcher task keeps its clone.
Tests (199 lib + 1 integration):
- Unit: default-deny NOT_FOUND for non-remote-safe; remote_safe dispatches;
trusted-peer dispatches all External; default-deny does NOT populate
capabilities (the load-bearing security assertion — verified by a handler
that inspects context.capabilities and the fact that the handler is never
reached for non-remote-safe ops); remote_safe op populates capabilities;
services/list peer-scoped hide/trusted variants; CallClient constructors;
CallCredentials builder; Send+Sync.
- Integration (tests/two_node_call.rs): real QUIC loopback — CallAdapter
server (self-signed cert via rcgen) accepts, CallClient connects,
client.call() round-trips to server/echo. Proves the connect path +
shared dispatch loop work end-to-end.
clippy + fmt + test all green.
Refs: tasks/call/client/call-client.md
Refs: docs/architecture/decisions/017-call-protocol-client-and-adapter-contract.md §1, §2, §7
Refs: docs/architecture/decisions/028-callclient-peer-scoped-registry-filtering.md
Refs: docs/architecture/crates/call/client-and-adapters.md
