Remove name ghosting when referring to receipts

federationapi/queue/destinationqueue.go

@@ -70,7 +70,7 @@ type destinationQueue struct {
 // Send event adds the event to the pending queue for the destination.
 // If the queue is empty then it starts a background goroutine to
 // start sending events to that destination.
-func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, nid *receipt.Receipt) {
+func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, dbReceipt *receipt.Receipt) {
 	if event == nil {
 		logrus.Errorf("attempt to send nil PDU with destination %q", oq.destination)
 		return
@@ -84,8 +84,8 @@ func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, ni
 		oq.pendingMutex.Lock()
 		if len(oq.pendingPDUs) < maxPDUsInMemory {
 			oq.pendingPDUs = append(oq.pendingPDUs, &queuedPDU{
-				pdu:     event,
+				pdu:          event,
-				receipt: nid,
+				eventReceipt: dbReceipt,
 			})
 		} else {
 			oq.overflowed.Store(true)
@@ -101,7 +101,7 @@ func (oq *destinationQueue) sendEvent(event *gomatrixserverlib.HeaderedEvent, ni
 // sendEDU adds the EDU event to the pending queue for the destination.
 // If the queue is empty then it starts a background goroutine to
 // start sending events to that destination.
-func (oq *destinationQueue) sendEDU(event *gomatrixserverlib.EDU, nid *receipt.Receipt) {
+func (oq *destinationQueue) sendEDU(event *gomatrixserverlib.EDU, dbReceipt *receipt.Receipt) {
 	if event == nil {
 		logrus.Errorf("attempt to send nil EDU with destination %q", oq.destination)
 		return
@@ -115,8 +115,8 @@ func (oq *destinationQueue) sendEDU(event *gomatrixserverlib.EDU, nid *receipt.R
 		oq.pendingMutex.Lock()
 		if len(oq.pendingEDUs) < maxEDUsInMemory {
 			oq.pendingEDUs = append(oq.pendingEDUs, &queuedEDU{
-				edu:     event,
+				edu:          event,
-				receipt: nid,
+				eventReceipt: dbReceipt,
 			})
 		} else {
 			oq.overflowed.Store(true)
@@ -210,10 +210,10 @@ func (oq *destinationQueue) getPendingFromDatabase() {
 	gotPDUs := map[string]struct{}{}
 	gotEDUs := map[string]struct{}{}
 	for _, pdu := range oq.pendingPDUs {
-		gotPDUs[pdu.receipt.String()] = struct{}{}
+		gotPDUs[pdu.eventReceipt.String()] = struct{}{}
 	}
 	for _, edu := range oq.pendingEDUs {
-		gotEDUs[edu.receipt.String()] = struct{}{}
+		gotEDUs[edu.eventReceipt.String()] = struct{}{}
 	}
 
 	overflowed := false
@@ -518,7 +518,7 @@ func (oq *destinationQueue) createTransaction(
 		// Append the JSON of the event, since this is a json.RawMessage type in the
 		// gomatrixserverlib.Transaction struct
 		t.PDUs = append(t.PDUs, pdu.pdu.JSON())
-		pduReceipts = append(pduReceipts, pdu.receipt)
+		pduReceipts = append(pduReceipts, pdu.eventReceipt)
 	}
 
 	// Do the same for pending EDUS in the queue.
@@ -528,7 +528,7 @@ func (oq *destinationQueue) createTransaction(
 			continue
 		}
 		t.EDUs = append(t.EDUs, *edu.edu)
-		eduReceipts = append(eduReceipts, edu.receipt)
+		eduReceipts = append(eduReceipts, edu.eventReceipt)
 	}
 
 	return t, pduReceipts, eduReceipts

federationapi/queue/queue.go

@@ -138,13 +138,13 @@ func NewOutgoingQueues(
 }
 
 type queuedPDU struct {
-	receipt *receipt.Receipt
+	dbReceipt *receipt.Receipt
-	pdu     *gomatrixserverlib.HeaderedEvent
+	pdu       *gomatrixserverlib.HeaderedEvent
 }
 
 type queuedEDU struct {
-	receipt *receipt.Receipt
+	dbReceipt *receipt.Receipt
-	edu     *gomatrixserverlib.EDU
+	edu       *gomatrixserverlib.EDU
 }
 
 func (oqs *OutgoingQueues) getQueue(destination gomatrixserverlib.ServerName) *destinationQueue {

federationapi/storage/interface.go

@@ -40,8 +40,8 @@ type Database interface {
 	GetPendingPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (pdus map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent, err error)
 	GetPendingEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, limit int) (edus map[*receipt.Receipt]*gomatrixserverlib.EDU, err error)
 
-	AssociatePDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *receipt.Receipt) error
+	AssociatePDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, dbReceipt *receipt.Receipt) error
-	AssociateEDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, receipt *receipt.Receipt, eduType string, expireEDUTypes map[string]time.Duration) error
+	AssociateEDUWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.ServerName]struct{}, dbReceipt *receipt.Receipt, eduType string, expireEDUTypes map[string]time.Duration) error
 
 	CleanPDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*receipt.Receipt) error
 	CleanEDUs(ctx context.Context, serverName gomatrixserverlib.ServerName, receipts []*receipt.Receipt) error

federationapi/storage/shared/receipt/receipt.go

@@ -20,6 +20,11 @@ package receipt
 
 import "fmt"
 
+// Receipt is a wrapper type used to represent a nid that corresponds to a unique row entry
+// in some database table.
+// The internal nid value cannot be modified after a Receipt has been created.
+// This guarantees a receipt will always refer to the same table entry that it was created
+// to represent.
 type Receipt struct {
 	nid int64
 }

federationapi/storage/shared/storage_edus.go

@@ -42,7 +42,7 @@ var defaultExpireEDUTypes = map[string]time.Duration{
 func (d *Database) AssociateEDUWithDestinations(
 	ctx context.Context,
 	destinations map[gomatrixserverlib.ServerName]struct{},
-	receipt *receipt.Receipt,
+	dbReceipt *receipt.Receipt,
 	eduType string,
 	expireEDUTypes map[string]time.Duration,
 ) error {
@@ -63,12 +63,12 @@ func (d *Database) AssociateEDUWithDestinations(
 		var err error
 		for destination := range destinations {
 			err = d.FederationQueueEDUs.InsertQueueEDU(
-				ctx,              // context
+				ctx,                // context
-				txn,              // SQL transaction
+				txn,                // SQL transaction
-				eduType,          // EDU type for coalescing
+				eduType,            // EDU type for coalescing
-				destination,      // destination server name
+				destination,        // destination server name
-				receipt.GetNID(), // NID from the federationapi_queue_json table
+				dbReceipt.GetNID(), // NID from the federationapi_queue_json table
-				expiresAt,        // The timestamp this EDU will expire
+				expiresAt,          // The timestamp this EDU will expire
 			)
 		}
 		return err

federationapi/storage/shared/storage_pdus.go

@@ -31,17 +31,17 @@ import (
 func (d *Database) AssociatePDUWithDestinations(
 	ctx context.Context,
 	destinations map[gomatrixserverlib.ServerName]struct{},
-	receipt *receipt.Receipt,
+	dbReceipt *receipt.Receipt,
 ) error {
 	return d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		var err error
 		for destination := range destinations {
 			err = d.FederationQueuePDUs.InsertQueuePDU(
-				ctx,              // context
+				ctx,                // context
-				txn,              // SQL transaction
+				txn,                // SQL transaction
-				"",               // transaction ID
+				"",                 // transaction ID
-				destination,      // destination server name
+				destination,        // destination server name
-				receipt.GetNID(), // NID from the federationapi_queue_json table
+				dbReceipt.GetNID(), // NID from the federationapi_queue_json table
 			)
 		}
 		return err

relayapi/storage/interface.go

@@ -23,7 +23,7 @@ import (
 
 type Database interface {
 	StoreTransaction(ctx context.Context, txn gomatrixserverlib.Transaction) (*receipt.Receipt, error)
-	AssociateTransactionWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.UserID]struct{}, transactionID gomatrixserverlib.TransactionID, receipt *receipt.Receipt) error
+	AssociateTransactionWithDestinations(ctx context.Context, destinations map[gomatrixserverlib.UserID]struct{}, transactionID gomatrixserverlib.TransactionID, dbReceipt *receipt.Receipt) error
 	CleanTransactions(ctx context.Context, userID gomatrixserverlib.UserID, receipts []*receipt.Receipt) error
 	GetTransaction(ctx context.Context, userID gomatrixserverlib.UserID) (*gomatrixserverlib.Transaction, *receipt.Receipt, error)
 	GetTransactionCount(ctx context.Context, userID gomatrixserverlib.UserID) (int64, error)

relayapi/storage/shared/storage.go

@@ -55,15 +55,15 @@ func (d *Database) StoreTransaction(
 		return nil, fmt.Errorf("d.insertQueueJSON: %w", err)
 	}
 
-	receipt := receipt.NewReceipt(nid)
+	newReceipt := receipt.NewReceipt(nid)
-	return &receipt, nil
+	return &newReceipt, nil
 }
 
 func (d *Database) AssociateTransactionWithDestinations(
 	ctx context.Context,
 	destinations map[gomatrixserverlib.UserID]struct{},
 	transactionID gomatrixserverlib.TransactionID,
-	receipt *receipt.Receipt,
+	dbReceipt *receipt.Receipt,
 ) error {
 	err := d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
 		var lastErr error
@@ -74,7 +74,7 @@ func (d *Database) AssociateTransactionWithDestinations(
 				txn,
 				transactionID,
 				destination.Domain(),
-				receipt.GetNID(),
+				dbReceipt.GetNID(),
 			)
 			if err != nil {
 				lastErr = fmt.Errorf("d.insertQueueEntry: %w", err)
@@ -92,8 +92,8 @@ func (d *Database) CleanTransactions(
 	receipts []*receipt.Receipt,
 ) error {
 	nids := make([]int64, len(receipts))
-	for i, receipt := range receipts {
+	for i, dbReceipt := range receipts {
-		nids[i] = receipt.GetNID()
+		nids[i] = dbReceipt.GetNID()
 	}
 
 	err := d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error {
@@ -145,8 +145,8 @@ func (d *Database) GetTransaction(
 		return nil, nil, fmt.Errorf("Unmarshal transaction: %w", err)
 	}
 
-	receipt := receipt.NewReceipt(firstNID)
+	newReceipt := receipt.NewReceipt(firstNID)
-	return transaction, &receipt, nil
+	return transaction, &newReceipt, nil
 }
 
 func (d *Database) GetTransactionCount(

test/memory_federation_db.go

@@ -97,9 +97,9 @@ func (d *InMemoryFederationDatabase) GetPendingPDUs(
 	pduCount := 0
 	pdus = make(map[*receipt.Receipt]*gomatrixserverlib.HeaderedEvent)
 	if receipts, ok := d.associatedPDUs[serverName]; ok {
-		for nid := range receipts {
+		for dbReceipt := range receipts {
-			if event, ok := d.pendingPDUs[nid]; ok {
+			if event, ok := d.pendingPDUs[dbReceipt]; ok {
-				pdus[nid] = event
+				pdus[dbReceipt] = event
 				pduCount++
 				if pduCount == limit {
 					break
@@ -121,9 +121,9 @@ func (d *InMemoryFederationDatabase) GetPendingEDUs(
 	eduCount := 0
 	edus = make(map[*receipt.Receipt]*gomatrixserverlib.EDU)
 	if receipts, ok := d.associatedEDUs[serverName]; ok {
-		for nid := range receipts {
+		for dbReceipt := range receipts {
-			if event, ok := d.pendingEDUs[nid]; ok {
+			if event, ok := d.pendingEDUs[dbReceipt]; ok {
-				edus[nid] = event
+				edus[dbReceipt] = event
 				eduCount++
 				if eduCount == limit {
 					break
@@ -137,17 +137,17 @@ func (d *InMemoryFederationDatabase) GetPendingEDUs(
 func (d *InMemoryFederationDatabase) AssociatePDUWithDestinations(
 	ctx context.Context,
 	destinations map[gomatrixserverlib.ServerName]struct{},
-	nid *receipt.Receipt,
+	dbReceipt *receipt.Receipt,
 ) error {
 	d.dbMutex.Lock()
 	defer d.dbMutex.Unlock()
 
-	if _, ok := d.pendingPDUs[nid]; ok {
+	if _, ok := d.pendingPDUs[dbReceipt]; ok {
 		for destination := range destinations {
 			if _, ok := d.associatedPDUs[destination]; !ok {
 				d.associatedPDUs[destination] = make(map[*receipt.Receipt]struct{})
 			}
-			d.associatedPDUs[destination][nid] = struct{}{}
+			d.associatedPDUs[destination][dbReceipt] = struct{}{}
 		}
 
 		return nil
@@ -159,19 +159,19 @@ func (d *InMemoryFederationDatabase) AssociatePDUWithDestinations(
 func (d *InMemoryFederationDatabase) AssociateEDUWithDestinations(
 	ctx context.Context,
 	destinations map[gomatrixserverlib.ServerName]struct{},
-	nid *receipt.Receipt,
+	dbReceipt *receipt.Receipt,
 	eduType string,
 	expireEDUTypes map[string]time.Duration,
 ) error {
 	d.dbMutex.Lock()
 	defer d.dbMutex.Unlock()
 
-	if _, ok := d.pendingEDUs[nid]; ok {
+	if _, ok := d.pendingEDUs[dbReceipt]; ok {
 		for destination := range destinations {
 			if _, ok := d.associatedEDUs[destination]; !ok {
 				d.associatedEDUs[destination] = make(map[*receipt.Receipt]struct{})
 			}
-			d.associatedEDUs[destination][nid] = struct{}{}
+			d.associatedEDUs[destination][dbReceipt] = struct{}{}
 		}
 
 		return nil
@@ -189,8 +189,8 @@ func (d *InMemoryFederationDatabase) CleanPDUs(
 	defer d.dbMutex.Unlock()
 
 	if pdus, ok := d.associatedPDUs[serverName]; ok {
-		for _, nid := range receipts {
+		for _, dbReceipt := range receipts {
-			delete(pdus, nid)
+			delete(pdus, dbReceipt)
 		}
 	}
 
@@ -206,8 +206,8 @@ func (d *InMemoryFederationDatabase) CleanEDUs(
 	defer d.dbMutex.Unlock()
 
 	if edus, ok := d.associatedEDUs[serverName]; ok {
-		for _, nid := range receipts {
+		for _, dbReceipt := range receipts {
-			delete(edus, nid)
+			delete(edus, dbReceipt)
 		}
 	}