Remove copy code of FindTopRunner

clustering/mock_test.go

@@ -217,65 +217,6 @@ func (o *mockOperator) IsSubsetGTID(ctx context.Context, set1, set2 string) (boo
  return len(map1) == 0, nil
 }
 
-// FindTopRunner returns the index of the slice whose `GlobalVariables.ExecutedGtidSet`
-// is most advanced. This may return ErrErrantTransactions for errant transactions
-// or ErrNoTopRunner if there is no such instance.
-func (o *mockOperator) FindTopRunner(ctx context.Context, status []*dbop.MySQLInstanceStatus) (int, error) {
- if o.failing {
- return -1, errors.New("mysqld is down")
- }
-
- latest := -1
- var latestGTID string
-
- for i := 0; i < len(status); i++ {
- if status[i] == nil {
- continue
- }
- repl := status[i].ReplicaStatus
- if repl == nil {
- continue
- }
-
- gtid := repl.RetrievedGtidSet
- if len(gtid) == 0 {
- continue
- }
-
- if len(latestGTID) == 0 {
- latest = i
- latestGTID = gtid
- continue
- }
-
- isSubset, err := o.IsSubsetGTID(ctx, gtid, latestGTID)
- if err != nil {
- return -1, err
- }
- if isSubset {
- continue
- }
-
- isSubset, err = o.IsSubsetGTID(ctx, latestGTID, gtid)
- if err != nil {
- return -1, err
- }
- if isSubset {
- latest = i
- latestGTID = gtid
- continue
- }
-
- return -1, fmt.Errorf("%w: set1=%s, set2=%s", dbop.ErrErrantTransactions, gtid, latestGTID)
- }
-
- if latest == -1 {
- return -1, dbop.ErrNoTopRunner
- }
-
- return latest, nil
-}
-
 // ConfigureReplica configures client-side replication.
 // If `symisync` is true, it enables client-side semi-synchronous replication.
 // In either case, it disables server-side semi-synchronous replication.

clustering/operations.go

@@ -218,7 +218,7 @@ func (p *managerProcess) failover(ctx context.Context, ss *StatusSet) error {
  candidates[i] = newStatus
  }
 
- candidate, err := op.FindTopRunner(ctx, candidates)
+ candidate, err := dbop.FindTopRunner(ctx, op, candidates)
  if err != nil {
  return fmt.Errorf("failed to choose the next primary: %w", err)
  }

pkg/dbop/gtid.go

@@ -5,7 +5,10 @@ import (
  "fmt"
 )
 
-func (o *operator) FindTopRunner(ctx context.Context, status []*MySQLInstanceStatus) (int, error) {
+// FindTopRunner returns the index of the slice whose `GlobalVariables.ExecutedGtidSet`
+// is most advanced. This may return ErrErrantTransactions for errant transactions
+// or ErrNoTopRunner if there is no such instance.
+func FindTopRunner(ctx context.Context, o Operator, status []*MySQLInstanceStatus) (int, error) {
  latest := -1
  var latestGTIDs string
 

pkg/dbop/gtid_test.go

@@ -24,7 +24,7 @@ var _ = Describe("FindTopRunner", func() {
  defer op.Close()
 
  statuses := make([]*MySQLInstanceStatus, 3)
- _, err = op.FindTopRunner(context.Background(), statuses)
+ _, err = FindTopRunner(context.Background(), op, statuses)
  Expect(err).To(MatchError(ErrNoTopRunner))
 
  set0 := `8e349184-bc14-11e3-8d4c-0800272864ba:1-29`
@@ -33,21 +33,21 @@ var _ = Describe("FindTopRunner", func() {
  statuses[0] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set0}}
  statuses[1] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set1}}
  statuses[2] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set2}}
- top, err := op.FindTopRunner(context.Background(), statuses)
+ top, err := FindTopRunner(context.Background(), op, statuses)
  Expect(err).NotTo(HaveOccurred())
  Expect(top).To(Equal(2))
 
  statuses[0] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set2}}
  statuses[1] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set0}}
  statuses[2] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set1}}
- top, err = op.FindTopRunner(context.Background(), statuses)
+ top, err = FindTopRunner(context.Background(), op, statuses)
  Expect(err).NotTo(HaveOccurred())
  Expect(top).To(Equal(0))
 
  statuses[0] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set1}}
  statuses[1] = nil
  statuses[2] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set2}}
- top, err = op.FindTopRunner(context.Background(), statuses)
+ top, err = FindTopRunner(context.Background(), op, statuses)
  Expect(err).NotTo(HaveOccurred())
  Expect(top).To(Equal(2))
 
@@ -59,7 +59,7 @@ var _ = Describe("FindTopRunner", func() {
  statuses[0] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set0}}
  statuses[1] = &MySQLInstanceStatus{ReplicaStatus: &ReplicaStatus{RetrievedGtidSet: set1}}
  statuses[2] = nil
- _, err = op.FindTopRunner(context.Background(), statuses)
+ _, err = FindTopRunner(context.Background(), op, statuses)
  Expect(err).To(MatchError(ErrErrantTransactions))
  })
 })

pkg/dbop/nop.go

@@ -35,10 +35,6 @@ func (o NopOperator) IsSubsetGTID(ctx context.Context, set1, set2 string) (bool,
  return false, ErrNop
 }
 
-func (o NopOperator) FindTopRunner(context.Context, []*MySQLInstanceStatus) (int, error) {
- return 0, ErrNop
-}
-
 func (o NopOperator) ConfigureReplica(ctx context.Context, source AccessInfo, semisync bool) error {
  return ErrNop
 }

pkg/dbop/operator.go

@@ -37,11 +37,6 @@ type Operator interface {
  // IsSubsetGTID returns true if set1 is a subset of set2.
  IsSubsetGTID(ctx context.Context, set1, set2 string) (bool, error)
 
- // FindTopRunner returns the index of the slice whose `GlobalVariables.ExecutedGtidSet`
- // is most advanced. This may return ErrErrantTransactions for errant transactions
- // or ErrNoTopRunner if there is no such instance.
- FindTopRunner(context.Context, []*MySQLInstanceStatus) (int, error)
-
  // ConfigureReplica configures client-side replication.
  // If `symisync` is true, it enables client-side semi-synchronous replication.
  // In either case, it disables server-side semi-synchronous replication.