go: doltdb,sqle/cluster: Some PR feedback. Small cleanups.

go/libraries/doltcore/doltdb/hooksdatabase.go

@@ -42,6 +42,13 @@ type CommitHook interface {
 	ExecuteForWorkingSets() bool
 }
 
+// If a commit hook supports this interface, it can be notified if waiting for
+// replication in the callback returned by |Execute| failed to complete in time
+// or returned an error.
+type NotifyWaitFailedCommitHook interface {
+	NotifyWaitFailed()
+}
+
 func (db hooksDatabase) SetCommitHooks(ctx context.Context, postHooks []CommitHook) hooksDatabase {
 	db.postCommitHooks = make([]CommitHook, len(postHooks))
 	copy(db.postCommitHooks, postHooks)
@@ -88,9 +95,7 @@ func (db hooksDatabase) ExecuteCommitHooks(ctx context.Context, ds datas.Dataset
 				}
 				if rsc != nil {
 					rsc.Wait[i+ioff] = f
-					if nf, ok := hook.(interface {
-						NotifyWaitFailed()
-					}); ok {
+					if nf, ok := hook.(NotifyWaitFailedCommitHook); ok {
 						rsc.NotifyWaitFailed[i+ioff] = nf.NotifyWaitFailed
 					} else {
 						rsc.NotifyWaitFailed[i+ioff] = func() {}

go/libraries/doltcore/sqle/cluster/commithook.go

@@ -32,6 +32,7 @@ import (
 )
 
 var _ doltdb.CommitHook = (*commithook)(nil)
+var _ doltdb.NotifyWaitFailedCommitHook = (*commithook)(nil)
 
 type commithook struct {
 	rootLgr              *logrus.Entry
@@ -56,7 +57,7 @@ type commithook struct {
 	// This is a slice of notification channels maintained by the
 	// commithook. The semantics are:
 	// 1. All accesses to |successChs| must happen with |mu| held.
-	// 2. There maybe be |0| or more channels in the slice.
+	// 2. There may be |0| or more channels in the slice.
 	// 3. As a reader, if |successChs| is non-empty, you should just read a value, for example, |successChs[0]| and use it. All entries will be closed at the same time. If |successChs| is empty when you need a channel, you should add one to it.
 	// 4. If you read a channel out of |successChs|, that channel will be closed on the next successful replication attempt. It will not be closed before then.
 	successChs []chan struct{}
@@ -65,7 +66,7 @@ type commithook struct {
 	// we are not already caught up, instead of blocking on a successCh
 	// actually indicated we are caught up. This is set to by a call to
 	// NotifyWaitFailed(), an optional interface on CommitHook.
-	circuitBreakerOpen bool
+	fastFailReplicationWait bool
 
 	role Role
 
@@ -162,7 +163,7 @@ func (h *commithook) replicate(ctx context.Context) {
 					close(ch)
 				}
 				h.successChs = nil
-				h.circuitBreakerOpen = false
+				h.fastFailReplicationWait = false
 			}
 			h.cond.Wait()
 			lgr.Tracef("cluster/commithook: background thread: woken up.")
@@ -413,7 +414,7 @@ func (h *commithook) Execute(ctx context.Context, ds datas.Dataset, db datas.Dat
 	}
 	var waitF func(context.Context) error
 	if !h.isCaughtUp() {
-		if h.circuitBreakerOpen {
+		if h.fastFailReplicationWait {
 			waitF = func(ctx context.Context) error {
 				return fmt.Errorf("circuit breaker for replication to %s/%s is open. this commit did not necessarily replicate successfully.", h.remotename, h.dbname)
 			}
@@ -438,7 +439,7 @@ func (h *commithook) Execute(ctx context.Context, ds datas.Dataset, db datas.Dat
 func (h *commithook) NotifyWaitFailed() {
 	h.mu.Lock()
 	defer h.mu.Unlock()
-	h.circuitBreakerOpen = true
+	h.fastFailReplicationWait = true
 }
 
 func (h *commithook) HandleError(ctx context.Context, err error) error {