[FIXED] Had a perf regression with some fss fixes. (#5632)

We could still use find if we know the status of wildcard.

Signed-off-by: Derek Collison <derek@nats.io>

server/filestore.go

@@ -2323,10 +2323,14 @@ func (mb *msgBlock) firstMatching(filter string, wc bool, start uint64, sm *Stor
 
 	// If we only have 1 subject currently and it matches our filter we can also set isAll.
 	if !isAll && mb.fss.Size() == 1 {
-		// Since mb.fss.Find won't work if filter is a wildcard, need to use Match instead.
-		mb.fss.Match(stringToBytes(filter), func(subject []byte, _ *SimpleState) {
-			isAll = true
-		})
+		if !wc {
+			_, isAll = mb.fss.Find(stringToBytes(filter))
+		} else {
+			// Since mb.fss.Find won't work if filter is a wildcard, need to use Match instead.
+			mb.fss.Match(stringToBytes(filter), func(subject []byte, _ *SimpleState) {
+				isAll = true
+			})
+		}
 	}
 	// Make sure to start at mb.first.seq if fseq < mb.first.seq
 	if seq := atomic.LoadUint64(&mb.first.seq); seq > fseq {
@@ -2982,17 +2986,14 @@ func (fs *fileStore) NumPending(sseq uint64, filter string, lastPerSubject bool)
 	}
 
 	isAll := filter == _EMPTY_ || filter == fwcs
+	if isAll && filter == _EMPTY_ {
+		filter = fwcs
+	}
 	wc := subjectHasWildcard(filter)
 
 	// See if filter was provided but its the only subject.
 	if !isAll && !wc && fs.psim.Size() == 1 {
-		// Since fs.psim.Find won't work if filter is a wildcard, need to use Match instead.
-		fs.psim.Match(stringToBytes(filter), func(subject []byte, _ *psi) {
-			isAll = true
-		})
-	}
-	if isAll && filter == _EMPTY_ {
-		filter = fwcs
+		_, isAll = fs.psim.Find(stringToBytes(filter))
 	}
 	// If we are isAll and have no deleted we can do a simpler calculation.
 	if !lastPerSubject && isAll && (fs.state.LastSeq-fs.state.FirstSeq+1) == fs.state.Msgs {