Add new scanner algorithm, can be enabled with DevNewScanner config option

scanner/flushable_map.go

@@ -0,0 +1,58 @@
+package scanner
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/deluan/navidrome/log"
+)
+
+const (
+	// batchSize used for albums/artists updates
+	batchSize = 5
+)
+
+type refreshCallbackFunc = func(ids ...string) error
+
+type flushableMap struct {
+	ctx       context.Context
+	flushFunc refreshCallbackFunc
+	entity    string
+	m         map[string]struct{}
+}
+
+func newFlushableMap(ctx context.Context, entity string, flushFunc refreshCallbackFunc) *flushableMap {
+	return &flushableMap{
+		ctx:       ctx,
+		flushFunc: flushFunc,
+		entity:    entity,
+		m:         map[string]struct{}{},
+	}
+}
+
+func (f *flushableMap) update(id string) error {
+	f.m[id] = struct{}{}
+	if len(f.m) >= batchSize {
+		err := f.flush()
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (f *flushableMap) flush() error {
+	if len(f.m) == 0 {
+		return nil
+	}
+	var ids []string
+	for id := range f.m {
+		ids = append(ids, id)
+		delete(f.m, id)
+	}
+	if err := f.flushFunc(ids...); err != nil {
+		log.Error(f.ctx, fmt.Sprintf("Error writing %ss to the DB", f.entity), err)
+		return err
+	}
+	return nil
+}