feat(dot/parachain/backing): handle statement message coming from overseer

dot/parachain/availability-store/availability_store.go

@@ -174,12 +174,10 @@ func uint32ToBytes(value uint32) []byte {
 
 // Run runs the availability store subsystem
 func (av *AvailabilityStoreSubsystem) Run(ctx context.Context, OverseerToSubsystem chan any,
-	SubsystemToOverseer chan any) error {
+	SubsystemToOverseer chan any) {
 
 	av.wg.Add(1)
 	go av.processMessages()
-
-	return nil
 }
 
 // Name returns the name of the availability store subsystem
@@ -361,7 +359,7 @@ func (av *AvailabilityStoreSubsystem) handleStoreChunk(msg StoreChunk) error {
 }
 
 func (av *AvailabilityStoreSubsystem) handleStoreAvailableData(msg StoreAvailableData) error {
-	err := av.availabilityStore.storeAvailableData(msg.CandidateHash, msg.AvailableData)
+	err := av.availabilityStore.storeAvailableData(msg.CandidateHash.Value, msg.AvailableData)
 	if err != nil {
 		msg.Sender <- err
 		return fmt.Errorf("store available data: %w", err)

dot/parachain/availability-store/availability_store_test.go

@@ -382,10 +382,12 @@ func TestAvailabilityStore_handleStoreAvailableData(t *testing.T) {
 	asSub := AvailabilityStoreSubsystem{
 		availabilityStore: *as,
 	}
-	msgSenderChan := make(chan any)
+	msgSenderChan := make(chan error)
 	msg := StoreAvailableData{
-		CandidateHash:       common.Hash{0x01},
-		NValidators:         0,
+		CandidateHash: parachaintypes.CandidateHash{
+			Value: common.Hash{0x01},
+		},
+		NumValidators:       0,
 		AvailableData:       AvailableData{},
 		ExpectedErasureRoot: common.Hash{},
 		Sender:              msgSenderChan,

dot/parachain/availability-store/messages.go

@@ -71,13 +71,19 @@ type StoreChunk struct {
 	Sender        chan any
 }
 
-// StoreAvailableData store an `AvailableData` in the AV store
+// StoreAvailableData computes and checks the erasure root of `AvailableData`
+// before storing its chunks in the AV store.
 type StoreAvailableData struct {
-	CandidateHash       common.Hash
-	NValidators         uint32
-	AvailableData       AvailableData
+	// A hash of the candidate this `ASMStoreAvailableData` belongs to.
+	CandidateHash parachaintypes.CandidateHash
+	// The number of validators in the session.
+	NumValidators uint32
+	// The `AvailableData` itself.
+	AvailableData AvailableData
+	// Erasure root we expect to get after chunking.
 	ExpectedErasureRoot common.Hash
-	Sender              chan any
+	// channel to send result to.
+	Sender chan error
 }
 
 // AvailableData is the data we keep available for each candidate included in the relay chain