go: sqle: cluster: Have Controller.waitforHooksToReplicate return []graceTransitionResult.

go/libraries/doltcore/sqle/cluster/controller.go

@@ -798,20 +798,11 @@ func (c *Controller) gracefulTransitionToStandby(saveConnID, minCaughtUpStandbys
 		return nil, errors.New("cluster/controller: failed to transition to standby; the set of replicated databases changed during the transition.")
 	}
 
-	res := make([]graceTransitionResult, len(states))
-	for i := range states {
-		hook := c.commithooks[i]
-		res[i] = graceTransitionResult{
-			caughtUp:  states[i],
-			database:  hook.dbname,
-			remote:    hook.remotename,
-			remoteUrl: hook.remoteurl,
-		}
-	}
+	res := states
 
 	if minCaughtUpStandbys == 0 {
-		for _, caughtUp := range states {
-			if !caughtUp {
+		for _, state := range states {
+			if !state.caughtUp {
 				c.lgr.Warnf("cluster/controller: failed to replicate all databases to all standbys; not transitioning to standby.")
 				return nil, errors.New("cluster/controller: failed to transition from primary to standby gracefully; could not replicate databases to standby in a timely manner.")
 			}
@@ -922,10 +913,15 @@ func (c *Controller) setProviderIsStandby(standby bool) {
 // up as part of this wait, and `false` otherwise.
 //
 // called with c.mu held
-func (c *Controller) waitForHooksToReplicate(timeout time.Duration) ([]bool, error) {
+func (c *Controller) waitForHooksToReplicate(timeout time.Duration) ([]graceTransitionResult, error) {
 	commithooks := make([]*commithook, len(c.commithooks))
 	copy(commithooks, c.commithooks)
-	caughtup := make([]bool, len(commithooks))
+	res := make([]graceTransitionResult, len(commithooks))
+	for i := range res {
+		res[i].database = commithooks[i].dbname
+		res[i].remote = commithooks[i].remotename
+		res[i].remoteUrl = commithooks[i].remoteurl
+	}
 	var wg sync.WaitGroup
 	wg.Add(len(commithooks))
 	for li, lch := range commithooks {
@@ -933,8 +929,8 @@ func (c *Controller) waitForHooksToReplicate(timeout time.Duration) ([]bool, err
 		ch := lch
 		ok := ch.setWaitNotify(func() {
 			// called with ch.mu locked.
-			if !caughtup[i] && ch.isCaughtUp() {
-				caughtup[i] = true
+			if !res[i].caughtUp && ch.isCaughtUp() {
+				res[i].caughtUp = true
 				wg.Done()
 			}
 		})
@@ -964,14 +960,14 @@ func (c *Controller) waitForHooksToReplicate(timeout time.Duration) ([]bool, err
 	// Make certain we don't leak the wg.Wait goroutine in the failure case.
 	// At this point, none of the callbacks will ever be called again and
 	// ch.setWaitNotify grabs a lock and so establishes the happens before.
-	for _, b := range caughtup {
-		if !b {
+	for _, b := range res {
+		if !b.caughtUp {
 			wg.Done()
 		}
 	}
 	<-done
 
-	return caughtup, nil
+	return res, nil
 }
 
 // Within a cluster, if remotesapi is configured with a tls_ca, we take the