roachpb: create IsParallelCommit method on EndTransactionRequest

Release note: None

pkg/roachpb/api.go

@@ -1102,6 +1102,13 @@ func (r *RefreshRangeRequest) flags() int {
 func (*SubsumeRequest) flags() int    { return isRead | isAlone | updatesReadTSCache }
 func (*RangeStatsRequest) flags() int { return isRead }
 
+// IsParallelCommit returns whether the EndTransaction request is attempting to
+// perform a parallel commit. See txn_interceptor_committer.go for a discussion
+// about parallel commits.
+func (etr *EndTransactionRequest) IsParallelCommit() bool {
+	return etr.Commit && len(etr.InFlightWrites) > 0
+}
+
 // Keys returns credentials in an aws.Config.
 func (b *ExportStorage_S3) Keys() *aws.Config {
 	return &aws.Config{

pkg/storage/batcheval/cmd_end_transaction.go

@@ -444,10 +444,7 @@ func canForwardSerializableTimestamp(txn *roachpb.Transaction, noRefreshSpans bo
 // that a transaction move to the STAGING state before committing or
 // not.
 func needsStaging(args *roachpb.EndTransactionRequest) bool {
-	if args.Commit {
-		return len(args.InFlightWrites) > 0
-	}
-	return false
+	return args.IsParallelCommit()
 }
 
 const intentResolutionBatchSize = 500

pkg/storage/replica_write.go

@@ -491,7 +491,7 @@ func maybeStripInFlightWrites(ba roachpb.BatchRequest) (roachpb.BatchRequest, er
 
 	et := args.(*roachpb.EndTransactionRequest)
 	otherReqs := ba.Requests[:len(ba.Requests)-1]
-	if len(et.InFlightWrites) == 0 || !et.Commit || len(otherReqs) == 0 {
+	if !et.IsParallelCommit() || len(otherReqs) == 0 {
 		return ba, nil
 	}