feat: multiple search indexes (#2514)

* refactor: abstract search interface

* wip: ~

* fix cycle import

* objs update hook

* wip: ~

* Delete search/none

* auto update index while cache changed

* db searcher

TODO: bleve init issue

cannot open index, metadata missing

* fix size type

why float64??

* fix typo

* fix nil pointer using

* api adapt ui

* bleve: fix clear & change struct

internal/search/update.go

@@ -0,0 +1,73 @@
+package search
+
+import (
+	"context"
+	"path"
+
+	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/alist-org/alist/v3/internal/op"
+	mapset "github.com/deckarep/golang-set/v2"
+	log "github.com/sirupsen/logrus"
+)
+
+func Update(parent string, objs []model.Obj) {
+	if instance != nil && !instance.Config().AutoUpdate {
+		return
+	}
+	ctx := context.Background()
+	// only update when index have built
+	progress, err := Progress(ctx)
+	if err != nil {
+		log.Errorf("update search index error while get progress: %+v", err)
+		return
+	}
+	if !progress.IsDone {
+		return
+	}
+	nodes, err := instance.Get(ctx, parent)
+	if err != nil {
+		log.Errorf("update search index error while get nodes: %+v", err)
+		return
+	}
+	now := mapset.NewSet[string]()
+	for i := range objs {
+		now.Add(objs[i].GetName())
+	}
+	old := mapset.NewSet[string]()
+	for i := range nodes {
+		old.Add(nodes[i].Name)
+	}
+	// delete data that no longer exists
+	toDelete := old.Difference(now)
+	toAdd := now.Difference(old)
+	for i := range nodes {
+		if toDelete.Contains(nodes[i].Name) {
+			err = instance.Del(ctx, path.Join(parent, nodes[i].Name))
+			if err != nil {
+				log.Errorf("update search index error while del old node: %+v", err)
+				return
+			}
+		}
+	}
+	for i := range objs {
+		if toAdd.Contains(objs[i].GetName()) {
+			err = instance.Index(ctx, parent, objs[i])
+			if err != nil {
+				log.Errorf("update search index error while index new node: %+v", err)
+				return
+			}
+			// build index if it's a folder
+			if objs[i].IsDir() {
+				err = BuildIndex(ctx, []string{path.Join(parent, objs[i].GetName())}, nil, -1, false)
+				if err != nil {
+					log.Errorf("update search index error while build index: %+v", err)
+					return
+				}
+			}
+		}
+	}
+}
+
+func init() {
+	op.RegisterObjsUpdateHook(Update)
+}