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/db/init.go

@@ -0,0 +1,16 @@
+package db
+
+import (
+	"github.com/alist-org/alist/v3/internal/search/searcher"
+)
+
+var config = searcher.Config{
+	Name:       "database",
+	AutoUpdate: true,
+}
+
+func init() {
+	searcher.RegisterSearcher(config, func() (searcher.Searcher, error) {
+		return &DB{}, nil
+	})
+}

internal/search/db/search.go

@@ -0,0 +1,46 @@
+package db
+
+import (
+	"context"
+
+	"github.com/alist-org/alist/v3/internal/db"
+	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/alist-org/alist/v3/internal/search/searcher"
+)
+
+type DB struct{}
+
+func (D DB) Config() searcher.Config {
+	return config
+}
+
+func (D DB) Search(ctx context.Context, req model.SearchReq) ([]model.SearchNode, int64, error) {
+	return db.SearchNode(req)
+}
+
+func (D DB) Index(ctx context.Context, parent string, obj model.Obj) error {
+	return db.CreateSearchNode(&model.SearchNode{
+		Parent: parent,
+		Name:   obj.GetName(),
+		IsDir:  obj.IsDir(),
+		Size:   obj.GetSize(),
+	})
+}
+
+func (D DB) Get(ctx context.Context, parent string) ([]model.SearchNode, error) {
+	return db.GetSearchNodesByParent(parent)
+}
+
+func (D DB) Del(ctx context.Context, prefix string) error {
+	return db.DeleteSearchNodesByParent(prefix)
+}
+
+func (D DB) Release(ctx context.Context) error {
+	return nil
+}
+
+func (D DB) Clear(ctx context.Context) error {
+	return db.ClearSearchNodes()
+}
+
+var _ searcher.Searcher = (*DB)(nil)