Prewrite optimization flag

internal/server/aof.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/tidwall/buntdb"
@@ -152,6 +153,7 @@ func (server *Server) writeAOF(args []string, d *commandDetailsT) error {
 	}
 
 	if server.aof != nil {
+		atomic.StoreInt32(&server.aofdirty, 1) // prewrite optimization flag
 		n := len(server.aofbuf)
 		server.aofbuf = redcon.AppendArray(server.aofbuf, len(args))
 		for _, arg := range args {

internal/server/server.go

@@ -94,6 +94,7 @@ type Server struct {
 
 	mu       sync.RWMutex
 	aof      *os.File                        // active aof file
+	aofdirty int32                           // mark the aofbuf as having data
 	aofbuf   []byte                          // prewrite buffer
 	aofsz    int                             // active size of the aof file
 	qdb      *buntdb.DB                      // hook queue log
@@ -473,9 +474,12 @@ func (server *Server) evioServe() error {
 	}
 
 	events.PreWrite = func() {
+		if atomic.LoadInt32(&server.aofdirty) != 0 {
 			server.mu.Lock()
 			defer server.mu.Unlock()
 			server.flushAOF()
+			atomic.StoreInt32(&server.aofdirty, 1)
+		}
 	}
 
 	return evio.Serve(events, fmt.Sprintf("%s:%d", server.host, server.port))