avoid closing closed channel

weed/query/engine/hybrid_message_scanner.go

@@ -8,6 +8,8 @@ import (
 	"io"
 	"strconv"
 	"strings"
+	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/parquet-go/parquet-go"
@@ -1365,6 +1367,8 @@ type StreamingFlushedDataSource struct {
 	doneChan     chan struct{}
 	started      bool
 	finished     bool
+	closed       int32 // atomic flag to prevent double close
+	mu           sync.RWMutex
 }
 
 func NewStreamingFlushedDataSource(hms *HybridMessageScanner, partition topic.Partition, options HybridScanOptions) *StreamingFlushedDataSource {
@@ -1390,9 +1394,14 @@ func (s *StreamingFlushedDataSource) startStreaming() {
 	s.started = true
 
 	go func() {
-		defer close(s.resultChan)
-		defer close(s.errorChan)
-		defer close(s.doneChan)
+		defer func() {
+			// Use atomic flag to ensure channels are only closed once
+			if atomic.CompareAndSwapInt32(&s.closed, 0, 1) {
+				close(s.resultChan)
+				close(s.errorChan)
+				close(s.doneChan)
+			}
+		}()
 
 		// Set up time range for scanning
 		startTime := time.Unix(0, s.options.StartTimeNs)
@@ -1497,8 +1506,11 @@ func (s *StreamingFlushedDataSource) HasMore() bool {
 }
 
 func (s *StreamingFlushedDataSource) Close() error {
-	if !s.finished {
+	// Use atomic flag to ensure channels are only closed once
+	if atomic.CompareAndSwapInt32(&s.closed, 0, 1) {
 		close(s.doneChan)
+		close(s.resultChan)
+		close(s.errorChan)
 	}
 	return nil
 }