enhanced authBackend to support authReadTx

server/storage/schema/auth.go

@@ -60,15 +60,25 @@ func (abe *authBackend) ForceCommit() {
 	abe.be.ForceCommit()
 }
 
+func (abe *authBackend) ReadTx() auth.AuthReadTx {
+	return &authReadTx{tx: abe.be.ReadTx(), lg: abe.lg}
+}
+
 func (abe *authBackend) BatchTx() auth.AuthBatchTx {
 	return &authBatchTx{tx: abe.be.BatchTx(), lg: abe.lg}
 }
 
+type authReadTx struct {
+	tx backend.ReadTx
+	lg *zap.Logger
+}
+
 type authBatchTx struct {
 	tx backend.BatchTx
 	lg *zap.Logger
 }
 
+var _ auth.AuthReadTx = (*authReadTx)(nil)
 var _ auth.AuthBatchTx = (*authBatchTx)(nil)
 
 func (atx *authBatchTx) UnsafeSaveAuthEnabled(enabled bool) {
@@ -86,22 +96,13 @@ func (atx *authBatchTx) UnsafeSaveAuthRevision(rev uint64) {
 }
 
 func (atx *authBatchTx) UnsafeReadAuthEnabled() bool {
-	_, vs := atx.tx.UnsafeRange(Auth, AuthEnabledKeyName, nil, 0)
-	if len(vs) == 1 {
-		if bytes.Equal(vs[0], authEnabled) {
-			return true
-		}
-	}
-	return false
+	arx := &authReadTx{tx: atx.tx, lg: atx.lg}
+	return arx.UnsafeReadAuthEnabled()
 }
 
 func (atx *authBatchTx) UnsafeReadAuthRevision() uint64 {
-	_, vs := atx.tx.UnsafeRange(Auth, AuthRevisionKeyName, nil, 0)
-	if len(vs) != 1 {
-		// this can happen in the initialization phase
-		return 0
-	}
-	return binary.BigEndian.Uint64(vs[0])
+	arx := &authReadTx{tx: atx.tx, lg: atx.lg}
+	return arx.UnsafeReadAuthRevision()
 }
 
 func (atx *authBatchTx) Lock() {
@@ -111,3 +112,30 @@ func (atx *authBatchTx) Lock() {
 func (atx *authBatchTx) Unlock() {
 	atx.tx.Unlock()
 }
+
+func (atx *authReadTx) UnsafeReadAuthEnabled() bool {
+	_, vs := atx.tx.UnsafeRange(Auth, AuthEnabledKeyName, nil, 0)
+	if len(vs) == 1 {
+		if bytes.Equal(vs[0], authEnabled) {
+			return true
+		}
+	}
+	return false
+}
+
+func (atx *authReadTx) UnsafeReadAuthRevision() uint64 {
+	_, vs := atx.tx.UnsafeRange(Auth, AuthRevisionKeyName, nil, 0)
+	if len(vs) != 1 {
+		// this can happen in the initialization phase
+		return 0
+	}
+	return binary.BigEndian.Uint64(vs[0])
+}
+
+func (atx *authReadTx) Lock() {
+	atx.tx.RLock()
+}
+
+func (atx *authReadTx) Unlock() {
+	atx.tx.RUnlock()
+}