Use a general approach to access custom/static/builtin assets (#24022)

The idea is to use a Layered Asset File-system (modules/assetfs/layered.go)

For example: when there are 2 layers: "custom", "builtin", when access
to asset "my/page.tmpl", the Layered Asset File-system will first try to
use "custom" assets, if not found, then use "builtin" assets.

This approach will hugely simplify a lot of code, make them testable.

Other changes:

* Simplify the AssetsHandlerFunc code
* Simplify the `gitea embedded` sub-command code

---------

Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

29 files changed, 624 insertions, 928 deletions

diff --git a/modules/assetfs/layered.go b/modules/assetfs/layered.go
new file mode 100644
index 0000000000..d032160a6f
--- /dev/null
+++ b/modules/assetfs/layered.go
@@ -0,0 +1,260 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package assetfs
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"io/fs"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sort"
+	"time"
+
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/process"
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/fsnotify/fsnotify"
+)
+
+// Layer represents a layer in a layered asset file-system. It has a name and works like http.FileSystem
+type Layer struct {
+	name      string
+	fs        http.FileSystem
+	localPath string
+}
+
+func (l *Layer) Name() string {
+	return l.name
+}
+
+// Open opens the named file. The caller is responsible for closing the file.
+func (l *Layer) Open(name string) (http.File, error) {
+	return l.fs.Open(name)
+}
+
+// Local returns a new Layer with the given name, it serves files from the given local path.
+func Local(name, base string, sub ...string) *Layer {
+	// TODO: the old behavior (StaticRootPath might not be absolute), not ideal, just keep the same as before
+	// Ideally, the caller should guarantee the base is absolute, guessing a relative path based on the current working directory is unreliable.
+	base, err := filepath.Abs(base)
+	if err != nil {
+		// This should never happen in a real system. If it happens, the user must have already been in trouble: the system is not able to resolve its own paths.
+		panic(fmt.Sprintf("Unable to get absolute path for %q: %v", base, err))
+	}
+	root := util.FilePathJoinAbs(base, sub...)
+	return &Layer{name: name, fs: http.Dir(root), localPath: root}
+}
+
+// Bindata returns a new Layer with the given name, it serves files from the given bindata asset.
+func Bindata(name string, fs http.FileSystem) *Layer {
+	return &Layer{name: name, fs: fs}
+}
+
+// LayeredFS is a layered asset file-system. It works like http.FileSystem, but it can have multiple layers.
+// The first layer is the top layer, and it will be used first.
+// If the file is not found in the top layer, it will be searched in the next layer.
+type LayeredFS struct {
+	layers []*Layer
+}
+
+// Layered returns a new LayeredFS with the given layers. The first layer is the top layer.
+func Layered(layers ...*Layer) *LayeredFS {
+	return &LayeredFS{layers: layers}
+}
+
+// Open opens the named file. The caller is responsible for closing the file.
+func (l *LayeredFS) Open(name string) (http.File, error) {
+	for _, layer := range l.layers {
+		f, err := layer.Open(name)
+		if err == nil || !os.IsNotExist(err) {
+			return f, err
+		}
+	}
+	return nil, fs.ErrNotExist
+}
+
+// ReadFile reads the named file.
+func (l *LayeredFS) ReadFile(elems ...string) ([]byte, error) {
+	bs, _, err := l.ReadLayeredFile(elems...)
+	return bs, err
+}
+
+// ReadLayeredFile reads the named file, and returns the layer name.
+func (l *LayeredFS) ReadLayeredFile(elems ...string) ([]byte, string, error) {
+	name := util.PathJoinRel(elems...)
+	for _, layer := range l.layers {
+		f, err := layer.Open(name)
+		if os.IsNotExist(err) {
+			continue
+		} else if err != nil {
+			return nil, layer.name, err
+		}
+		bs, err := io.ReadAll(f)
+		_ = f.Close()
+		return bs, layer.name, err
+	}
+	return nil, "", fs.ErrNotExist
+}
+
+func shouldInclude(info fs.FileInfo, fileMode ...bool) bool {
+	if util.CommonSkip(info.Name()) {
+		return false
+	}
+	if len(fileMode) == 0 {
+		return true
+	} else if len(fileMode) == 1 {
+		return fileMode[0] == !info.Mode().IsDir()
+	}
+	panic("too many arguments for fileMode in shouldInclude")
+}
+
+func readDir(layer *Layer, name string) ([]fs.FileInfo, error) {
+	f, err := layer.Open(name)
+	if os.IsNotExist(err) {
+		return nil, nil
+	} else if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	return f.Readdir(-1)
+}
+
+// ListFiles lists files/directories in the given directory. The fileMode controls the returned files.
+// * omitted: all files and directories will be returned.
+// * true: only files will be returned.
+// * false: only directories will be returned.
+// The returned files are sorted by name.
+func (l *LayeredFS) ListFiles(name string, fileMode ...bool) ([]string, error) {
+	fileMap := map[string]bool{}
+	for _, layer := range l.layers {
+		infos, err := readDir(layer, name)
+		if err != nil {
+			return nil, err
+		}
+		for _, info := range infos {
+			if shouldInclude(info, fileMode...) {
+				fileMap[info.Name()] = true
+			}
+		}
+	}
+	files := make([]string, 0, len(fileMap))
+	for file := range fileMap {
+		files = append(files, file)
+	}
+	sort.Strings(files)
+	return files, nil
+}
+
+// ListAllFiles returns files/directories in the given directory, including subdirectories, recursively.
+// The fileMode controls the returned files:
+// * omitted: all files and directories will be returned.
+// * true: only files will be returned.
+// * false: only directories will be returned.
+// The returned files are sorted by name.
+func (l *LayeredFS) ListAllFiles(name string, fileMode ...bool) ([]string, error) {
+	return listAllFiles(l.layers, name, fileMode...)
+}
+
+func listAllFiles(layers []*Layer, name string, fileMode ...bool) ([]string, error) {
+	fileMap := map[string]bool{}
+	var list func(dir string) error
+	list = func(dir string) error {
+		for _, layer := range layers {
+			infos, err := readDir(layer, dir)
+			if err != nil {
+				return err
+			}
+			for _, info := range infos {
+				path := util.PathJoinRelX(dir, info.Name())
+				if shouldInclude(info, fileMode...) {
+					fileMap[path] = true
+				}
+				if info.IsDir() {
+					if err = list(path); err != nil {
+						return err
+					}
+				}
+			}
+		}
+		return nil
+	}
+	if err := list(name); err != nil {
+		return nil, err
+	}
+	var files []string
+	for file := range fileMap {
+		files = append(files, file)
+	}
+	sort.Strings(files)
+	return files, nil
+}
+
+// WatchLocalChanges watches local changes in the file-system. It's used to help to reload assets when the local file-system changes.
+func (l *LayeredFS) WatchLocalChanges(ctx context.Context, callback func()) {
+	ctx, _, finished := process.GetManager().AddTypedContext(ctx, "Asset Local FileSystem Watcher", process.SystemProcessType, true)
+	defer finished()
+
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		log.Error("Unable to create watcher for asset local file-system: %v", err)
+		return
+	}
+	defer watcher.Close()
+
+	for _, layer := range l.layers {
+		if layer.localPath == "" {
+			continue
+		}
+		layerDirs, err := listAllFiles([]*Layer{layer}, ".", false)
+		if err != nil {
+			log.Error("Unable to list directories for asset local file-system %q: %v", layer.localPath, err)
+			continue
+		}
+		for _, dir := range layerDirs {
+			if err = watcher.Add(util.FilePathJoinAbs(layer.localPath, dir)); err != nil {
+				log.Error("Unable to watch directory %s: %v", dir, err)
+			}
+		}
+	}
+
+	debounce := util.Debounce(100 * time.Millisecond)
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case event, ok := <-watcher.Events:
+			if !ok {
+				return
+			}
+			log.Trace("Watched asset local file-system had event: %v", event)
+			debounce(callback)
+		case err, ok := <-watcher.Errors:
+			if !ok {
+				return
+			}
+			log.Error("Watched asset local file-system had error: %v", err)
+		}
+	}
+}
+
+// GetFileLayerName returns the name of the first-seen layer that contains the given file.
+func (l *LayeredFS) GetFileLayerName(elems ...string) string {
+	name := util.PathJoinRel(elems...)
+	for _, layer := range l.layers {
+		f, err := layer.Open(name)
+		if os.IsNotExist(err) {
+			continue
+		} else if err != nil {
+			return ""
+		}
+		_ = f.Close()
+		return layer.name
+	}
+	return ""
+}
diff --git a/modules/assetfs/layered_test.go b/modules/assetfs/layered_test.go
new file mode 100644
index 0000000000..b82111e745
--- /dev/null
+++ b/modules/assetfs/layered_test.go
@@ -0,0 +1,109 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package assetfs
+
+import (
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestLayered(t *testing.T) {
+	dir := filepath.Join(t.TempDir(), "assetfs-layers")
+	dir1 := filepath.Join(dir, "l1")
+	dir2 := filepath.Join(dir, "l2")
+
+	mkdir := func(elems ...string) {
+		assert.NoError(t, os.MkdirAll(filepath.Join(elems...), 0o755))
+	}
+	write := func(content string, elems ...string) {
+		assert.NoError(t, os.WriteFile(filepath.Join(elems...), []byte(content), 0o644))
+	}
+
+	// d1 & f1: only in "l1"; d2 & f2: only in "l2"
+	// da & fa: in both "l1" and "l2"
+	mkdir(dir1, "d1")
+	mkdir(dir1, "da")
+	mkdir(dir1, "da/sub1")
+
+	mkdir(dir2, "d2")
+	mkdir(dir2, "da")
+	mkdir(dir2, "da/sub2")
+
+	write("dummy", dir1, ".DS_Store")
+	write("f1", dir1, "f1")
+	write("fa-1", dir1, "fa")
+	write("d1-f", dir1, "d1/f")
+	write("da-f-1", dir1, "da/f")
+
+	write("f2", dir2, "f2")
+	write("fa-2", dir2, "fa")
+	write("d2-f", dir2, "d2/f")
+	write("da-f-2", dir2, "da/f")
+
+	assets := Layered(Local("l1", dir1), Local("l2", dir2))
+
+	f, err := assets.Open("f1")
+	assert.NoError(t, err)
+	bs, err := io.ReadAll(f)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "f1", string(bs))
+	_ = f.Close()
+
+	assertRead := func(expected string, expectedErr error, elems ...string) {
+		bs, err := assets.ReadFile(elems...)
+		if err != nil {
+			assert.ErrorAs(t, err, &expectedErr)
+		} else {
+			assert.NoError(t, err)
+			assert.Equal(t, expected, string(bs))
+		}
+	}
+	assertRead("f1", nil, "f1")
+	assertRead("f2", nil, "f2")
+	assertRead("fa-1", nil, "fa")
+
+	assertRead("d1-f", nil, "d1/f")
+	assertRead("d2-f", nil, "d2/f")
+	assertRead("da-f-1", nil, "da/f")
+
+	assertRead("", fs.ErrNotExist, "no-such")
+
+	files, err := assets.ListFiles(".", true)
+	assert.NoError(t, err)
+	assert.EqualValues(t, []string{"f1", "f2", "fa"}, files)
+
+	files, err = assets.ListFiles(".", false)
+	assert.NoError(t, err)
+	assert.EqualValues(t, []string{"d1", "d2", "da"}, files)
+
+	files, err = assets.ListFiles(".")
+	assert.NoError(t, err)
+	assert.EqualValues(t, []string{"d1", "d2", "da", "f1", "f2", "fa"}, files)
+
+	files, err = assets.ListAllFiles(".", true)
+	assert.NoError(t, err)
+	assert.EqualValues(t, []string{"d1/f", "d2/f", "da/f", "f1", "f2", "fa"}, files)
+
+	files, err = assets.ListAllFiles(".", false)
+	assert.NoError(t, err)
+	assert.EqualValues(t, []string{"d1", "d2", "da", "da/sub1", "da/sub2"}, files)
+
+	files, err = assets.ListAllFiles(".")
+	assert.NoError(t, err)
+	assert.EqualValues(t, []string{
+		"d1", "d1/f",
+		"d2", "d2/f",
+		"da", "da/f", "da/sub1", "da/sub2",
+		"f1", "f2", "fa",
+	}, files)
+
+	assert.Empty(t, assets.GetFileLayerName("no-such"))
+	assert.EqualValues(t, "l1", assets.GetFileLayerName("f1"))
+	assert.EqualValues(t, "l2", assets.GetFileLayerName("f2"))
+}
diff --git a/modules/auth/pam/pam_stub.go b/modules/auth/pam/pam_stub.go
index a48e89860e..3631eeeda7 100644
--- a/modules/auth/pam/pam_stub.go
+++ b/modules/auth/pam/pam_stub.go
@@ -14,5 +14,9 @@ var Supported = false
 
 // Auth not supported lack of pam tag
 func Auth(serviceName, userName, passwd string) (string, error) {
-	return "", errors.New("PAM not supported")
+	// bypass the lint on callers: SA4023: this comparison is always true (staticcheck)
+	if !Supported {
+		return "", errors.New("PAM not supported")
+	}
+	return "", nil
 }
diff --git a/modules/context/context.go b/modules/context/context.go
index bd561be0f5..e2e120ba38 100644
--- a/modules/context/context.go
+++ b/modules/context/context.go
@@ -240,19 +240,15 @@ func (ctx *Context) HTML(status int, name base.TplName) {
 				}
 				line, _ := strconv.Atoi(lineStr) // Cannot error out as groups[2] is [1-9][0-9]*
 				pos, _ := strconv.Atoi(posStr)   // Cannot error out as groups[3] is [1-9][0-9]*
-				filename, filenameErr := templates.GetAssetFilename("templates/" + errorTemplateName + ".tmpl")
-				if filenameErr != nil {
-					filename = "(template) " + errorTemplateName
-				}
+				assetLayerName := templates.AssetFS().GetFileLayerName(errorTemplateName + ".tmpl")
+				filename := fmt.Sprintf("(%s) %s", assetLayerName, errorTemplateName)
 				if errorTemplateName != string(name) {
 					filename += " (subtemplate of " + string(name) + ")"
 				}
 				err = fmt.Errorf("failed to render %s, error: %w:\n%s", filename, err, templates.GetLineFromTemplate(errorTemplateName, line, target, pos))
 			} else {
-				filename, filenameErr := templates.GetAssetFilename("templates/" + execErr.Name + ".tmpl")
-				if filenameErr != nil {
-					filename = "(template) " + execErr.Name
-				}
+				assetLayerName := templates.AssetFS().GetFileLayerName(execErr.Name + ".tmpl")
+				filename := fmt.Sprintf("(%s) %s", assetLayerName, execErr.Name)
 				if execErr.Name != string(name) {
 					filename += " (subtemplate of " + string(name) + ")"
 				}
diff --git a/modules/doctor/paths.go b/modules/doctor/paths.go
index 7b1c6ce9ad..d7bf2539e7 100644
--- a/modules/doctor/paths.go
+++ b/modules/doctor/paths.go
@@ -9,7 +9,6 @@ import (
 	"os"
 
 	"code.gitea.io/gitea/modules/log"
-	"code.gitea.io/gitea/modules/options"
 	"code.gitea.io/gitea/modules/setting"
 )
 
@@ -79,7 +78,7 @@ func checkConfigurationFiles(ctx context.Context, logger log.Logger, autofix boo
 		{"Log Root Path", setting.Log.RootPath, true, true, true},
 	}
 
-	if options.IsDynamic() {
+	if !setting.HasBuiltinBindata {
 		configurationFiles = append(configurationFiles, configurationFile{"Static File Root Path", setting.StaticRootPath, true, true, false})
 	}
 
diff --git a/modules/options/base.go b/modules/options/base.go
index 7882ed0081..6c6e3839f4 100644
--- a/modules/options/base.go
+++ b/modules/options/base.go
@@ -4,131 +4,39 @@
 package options
 
 import (
-	"fmt"
-	"io/fs"
-	"os"
-	"path/filepath"
-
-	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/setting"
-	"code.gitea.io/gitea/modules/util"
 )
 
-var directories = make(directorySet)
+func CustomAssets() *assetfs.Layer {
+	return assetfs.Local("custom", setting.CustomPath, "options")
+}
+
+func AssetFS() *assetfs.LayeredFS {
+	return assetfs.Layered(CustomAssets(), BuiltinAssets())
+}
 
 // Locale reads the content of a specific locale from static/bindata or custom path.
 func Locale(name string) ([]byte, error) {
-	return fileFromOptionsDir("locale", name)
+	return AssetFS().ReadFile("locale", name)
 }
 
 // Readme reads the content of a specific readme from static/bindata or custom path.
 func Readme(name string) ([]byte, error) {
-	return fileFromOptionsDir("readme", name)
+	return AssetFS().ReadFile("readme", name)
 }
 
 // Gitignore reads the content of a gitignore locale from static/bindata or custom path.
 func Gitignore(name string) ([]byte, error) {
-	return fileFromOptionsDir("gitignore", name)
+	return AssetFS().ReadFile("gitignore", name)
 }
 
 // License reads the content of a specific license from static/bindata or custom path.
 func License(name string) ([]byte, error) {
-	return fileFromOptionsDir("license", name)
+	return AssetFS().ReadFile("license", name)
 }
 
 // Labels reads the content of a specific labels from static/bindata or custom path.
 func Labels(name string) ([]byte, error) {
-	return fileFromOptionsDir("label", name)
-}
-
-// WalkLocales reads the content of a specific locale
-func WalkLocales(callback func(path, name string, d fs.DirEntry, err error) error) error {
-	if IsDynamic() {
-		if err := walkAssetDir(filepath.Join(setting.StaticRootPath, "options", "locale"), callback); err != nil && !os.IsNotExist(err) {
-			return fmt.Errorf("failed to walk locales. Error: %w", err)
-		}
-	}
-
-	if err := walkAssetDir(filepath.Join(setting.CustomPath, "options", "locale"), callback); err != nil && !os.IsNotExist(err) {
-		return fmt.Errorf("failed to walk locales. Error: %w", err)
-	}
-	return nil
-}
-
-func walkAssetDir(root string, callback func(path, name string, d fs.DirEntry, err error) error) error {
-	if err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
-		// name is the path relative to the root
-		name := path[len(root):]
-		if len(name) > 0 && name[0] == '/' {
-			name = name[1:]
-		}
-		if err != nil {
-			if os.IsNotExist(err) {
-				return callback(path, name, d, err)
-			}
-			return err
-		}
-		if util.CommonSkip(d.Name()) {
-			if d.IsDir() {
-				return fs.SkipDir
-			}
-			return nil
-		}
-		return callback(path, name, d, err)
-	}); err != nil && !os.IsNotExist(err) {
-		return fmt.Errorf("unable to get files for assets in %s: %w", root, err)
-	}
-	return nil
-}
-
-// mustLocalPathAbs coverts a path to absolute path
-// FIXME: the old behavior (StaticRootPath might not be absolute), not ideal, just keep the same as before
-func mustLocalPathAbs(s string) string {
-	abs, err := filepath.Abs(s)
-	if err != nil {
-		// This should never happen in a real system. If it happens, the user must have already been in trouble: the system is not able to resolve its own paths.
-		log.Fatal("Unable to get absolute path for %q: %v", s, err)
-	}
-	return abs
-}
-
-func joinLocalPaths(baseDirs []string, subDir string, elems ...string) (paths []string) {
-	abs := make([]string, len(elems)+2)
-	abs[1] = subDir
-	copy(abs[2:], elems)
-	for _, baseDir := range baseDirs {
-		abs[0] = mustLocalPathAbs(baseDir)
-		paths = append(paths, util.FilePathJoinAbs(abs...))
-	}
-	return paths
-}
-
-func listLocalDirIfExist(baseDirs []string, subDir string, elems ...string) (files []string, err error) {
-	for _, localPath := range joinLocalPaths(baseDirs, subDir, elems...) {
-		isDir, err := util.IsDir(localPath)
-		if err != nil {
-			return nil, fmt.Errorf("unable to check if path %q is a directory. %w", localPath, err)
-		} else if !isDir {
-			continue
-		}
-
-		dirFiles, err := util.StatDir(localPath, true)
-		if err != nil {
-			return nil, fmt.Errorf("unable to read directory %q. %w", localPath, err)
-		}
-		files = append(files, dirFiles...)
-	}
-	return files, nil
-}
-
-func readLocalFile(baseDirs []string, subDir string, elems ...string) ([]byte, error) {
-	for _, localPath := range joinLocalPaths(baseDirs, subDir, elems...) {
-		data, err := os.ReadFile(localPath)
-		if err == nil {
-			return data, nil
-		} else if !os.IsNotExist(err) {
-			log.Error("Unable to read file %q. Error: %v", localPath, err)
-		}
-	}
-	return nil, os.ErrNotExist
+	return AssetFS().ReadFile("label", name)
 }
diff --git a/modules/options/dynamic.go b/modules/options/dynamic.go
index 3d6261983f..085492d11c 100644
--- a/modules/options/dynamic.go
+++ b/modules/options/dynamic.go
@@ -6,29 +6,10 @@
 package options
 
 import (
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/setting"
 )
 
-// Dir returns all files from static or custom directory.
-func Dir(name string) ([]string, error) {
-	if directories.Filled(name) {
-		return directories.Get(name), nil
-	}
-
-	result, err := listLocalDirIfExist([]string{setting.CustomPath, setting.StaticRootPath}, "options", name)
-	if err != nil {
-		return nil, err
-	}
-
-	return directories.AddAndGet(name, result), nil
-}
-
-// fileFromOptionsDir is a helper to read files from custom or static path.
-func fileFromOptionsDir(elems ...string) ([]byte, error) {
-	return readLocalFile([]string{setting.CustomPath, setting.StaticRootPath}, "options", elems...)
-}
-
-// IsDynamic will return false when using embedded data (-tags bindata)
-func IsDynamic() bool {
-	return true
+func BuiltinAssets() *assetfs.Layer {
+	return assetfs.Local("builtin(static)", setting.StaticRootPath, "options")
 }
diff --git a/modules/options/options.go b/modules/options/options.go
deleted file mode 100644
index 17a8fa482e..0000000000
--- a/modules/options/options.go
+++ /dev/null
@@ -1,45 +0,0 @@
-// Copyright 2016 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package options
-
-type directorySet map[string][]string
-
-func (s directorySet) Add(key string, value []string) {
-	_, ok := s[key]
-
-	if !ok {
-		s[key] = make([]string, 0, len(value))
-	}
-
-	s[key] = append(s[key], value...)
-}
-
-func (s directorySet) Get(key string) []string {
-	_, ok := s[key]
-
-	if ok {
-		result := []string{}
-		seen := map[string]string{}
-
-		for _, val := range s[key] {
-			if _, ok := seen[val]; !ok {
-				result = append(result, val)
-				seen[val] = val
-			}
-		}
-
-		return result
-	}
-
-	return []string{}
-}
-
-func (s directorySet) AddAndGet(key string, value []string) []string {
-	s.Add(key, value)
-	return s.Get(key)
-}
-
-func (s directorySet) Filled(key string) bool {
-	return len(s[key]) > 0
-}
diff --git a/modules/options/static.go b/modules/options/static.go
index 0482dea681..72b28e990e 100644
--- a/modules/options/static.go
+++ b/modules/options/static.go
@@ -6,98 +6,9 @@
 package options
 
 import (
-	"fmt"
-	"io"
-
-	"code.gitea.io/gitea/modules/setting"
-	"code.gitea.io/gitea/modules/util"
+	"code.gitea.io/gitea/modules/assetfs"
 )
 
-// Dir returns all files from custom directory or bindata.
-func Dir(name string) ([]string, error) {
-	if directories.Filled(name) {
-		return directories.Get(name), nil
-	}
-
-	result, err := listLocalDirIfExist([]string{setting.CustomPath}, "options", name)
-	if err != nil {
-		return nil, err
-	}
-
-	files, err := AssetDir(name)
-	if err != nil {
-		return []string{}, fmt.Errorf("unable to read embedded directory %q. %w", name, err)
-	}
-
-	result = append(result, files...)
-	return directories.AddAndGet(name, result), nil
-}
-
-func AssetDir(dirName string) ([]string, error) {
-	d, err := Assets.Open(dirName)
-	if err != nil {
-		return nil, err
-	}
-	defer d.Close()
-
-	files, err := d.Readdir(-1)
-	if err != nil {
-		return nil, err
-	}
-	results := make([]string, 0, len(files))
-	for _, file := range files {
-		results = append(results, file.Name())
-	}
-	return results, nil
-}
-
-// fileFromOptionsDir is a helper to read files from custom path or bindata.
-func fileFromOptionsDir(elems ...string) ([]byte, error) {
-	// only try custom dir, no static dir
-	if data, err := readLocalFile([]string{setting.CustomPath}, "options", elems...); err == nil {
-		return data, nil
-	}
-
-	f, err := Assets.Open(util.PathJoinRelX(elems...))
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	return io.ReadAll(f)
-}
-
-func Asset(name string) ([]byte, error) {
-	f, err := Assets.Open("/" + name)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	return io.ReadAll(f)
-}
-
-func AssetNames() []string {
-	realFS := Assets.(vfsgen۰FS)
-	results := make([]string, 0, len(realFS))
-	for k := range realFS {
-		results = append(results, k[1:])
-	}
-	return results
-}
-
-func AssetIsDir(name string) (bool, error) {
-	if f, err := Assets.Open("/" + name); err != nil {
-		return false, err
-	} else {
-		defer f.Close()
-		if fi, err := f.Stat(); err != nil {
-			return false, err
-		} else {
-			return fi.IsDir(), nil
-		}
-	}
-}
-
-// IsDynamic will return false when using embedded data (-tags bindata)
-func IsDynamic() bool {
-	return false
+func BuiltinAssets() *assetfs.Layer {
+	return assetfs.Bindata("builtin(bindata)", Assets)
 }
diff --git a/modules/public/public.go b/modules/public/public.go
index 2c96cf9e76..0c0e6dc1cc 100644
--- a/modules/public/public.go
+++ b/modules/public/public.go
@@ -4,11 +4,15 @@
 package public
 
 import (
+	"bytes"
+	"io"
 	"net/http"
 	"os"
-	"path/filepath"
+	"path"
 	"strings"
+	"time"
 
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/container"
 	"code.gitea.io/gitea/modules/httpcache"
 	"code.gitea.io/gitea/modules/log"
@@ -16,55 +20,31 @@ import (
 	"code.gitea.io/gitea/modules/util"
 )
 
-// Options represents the available options to configure the handler.
-type Options struct {
-	Directory   string
-	Prefix      string
-	CorsHandler func(http.Handler) http.Handler
+func CustomAssets() *assetfs.Layer {
+	return assetfs.Local("custom", setting.CustomPath, "public")
 }
 
-// AssetsURLPathPrefix is the path prefix for static asset files
-const AssetsURLPathPrefix = "/assets/"
+func AssetFS() *assetfs.LayeredFS {
+	return assetfs.Layered(CustomAssets(), BuiltinAssets())
+}
 
 // AssetsHandlerFunc implements the static handler for serving custom or original assets.
-func AssetsHandlerFunc(opts *Options) http.HandlerFunc {
-	custPath := filepath.Join(setting.CustomPath, "public")
-	if !filepath.IsAbs(custPath) {
-		custPath = filepath.Join(setting.AppWorkPath, custPath)
-	}
-	if !filepath.IsAbs(opts.Directory) {
-		opts.Directory = filepath.Join(setting.AppWorkPath, opts.Directory)
-	}
-	if !strings.HasSuffix(opts.Prefix, "/") {
-		opts.Prefix += "/"
-	}
-
+func AssetsHandlerFunc(prefix string) http.HandlerFunc {
+	assetFS := AssetFS()
+	prefix = strings.TrimSuffix(prefix, "/") + "/"
 	return func(resp http.ResponseWriter, req *http.Request) {
-		if req.Method != "GET" && req.Method != "HEAD" {
-			resp.WriteHeader(http.StatusNotFound)
+		subPath := req.URL.Path
+		if !strings.HasPrefix(subPath, prefix) {
 			return
 		}
+		subPath = strings.TrimPrefix(subPath, prefix)
 
-		if opts.CorsHandler != nil {
-			var corsSent bool
-			opts.CorsHandler(http.HandlerFunc(func(http.ResponseWriter, *http.Request) {
-				corsSent = true
-			})).ServeHTTP(resp, req)
-			// If CORS is not sent, the response must have been written by other handlers
-			if !corsSent {
-				return
-			}
-		}
-
-		file := req.URL.Path[len(opts.Prefix):]
-
-		// custom files
-		if opts.handle(resp, req, http.Dir(custPath), file) {
+		if req.Method != "GET" && req.Method != "HEAD" {
+			resp.WriteHeader(http.StatusNotFound)
 			return
 		}
 
-		// internal files
-		if opts.handle(resp, req, fileSystem(opts.Directory), file) {
+		if handleRequest(resp, req, assetFS, subPath) {
 			return
 		}
 
@@ -85,13 +65,13 @@ func parseAcceptEncoding(val string) container.Set[string] {
 // setWellKnownContentType will set the Content-Type if the file is a well-known type.
 // See the comments of detectWellKnownMimeType
 func setWellKnownContentType(w http.ResponseWriter, file string) {
-	mimeType := detectWellKnownMimeType(filepath.Ext(file))
+	mimeType := detectWellKnownMimeType(path.Ext(file))
 	if mimeType != "" {
 		w.Header().Set("Content-Type", mimeType)
 	}
 }
 
-func (opts *Options) handle(w http.ResponseWriter, req *http.Request, fs http.FileSystem, file string) bool {
+func handleRequest(w http.ResponseWriter, req *http.Request, fs http.FileSystem, file string) bool {
 	// actually, fs (http.FileSystem) is designed to be a safe interface, relative paths won't bypass its parent directory, it's also fine to do a clean here
 	f, err := fs.Open(util.PathJoinRelX(file))
 	if err != nil {
@@ -121,8 +101,34 @@ func (opts *Options) handle(w http.ResponseWriter, req *http.Request, fs http.Fi
 		return true
 	}
 
-	setWellKnownContentType(w, file)
-
 	serveContent(w, req, fi, fi.ModTime(), f)
 	return true
 }
+
+type GzipBytesProvider interface {
+	GzipBytes() []byte
+}
+
+// serveContent serve http content
+func serveContent(w http.ResponseWriter, req *http.Request, fi os.FileInfo, modtime time.Time, content io.ReadSeeker) {
+	setWellKnownContentType(w, fi.Name())
+
+	encodings := parseAcceptEncoding(req.Header.Get("Accept-Encoding"))
+	if encodings.Contains("gzip") {
+		// try to provide gzip content directly from bindata (provided by vfsgen۰CompressedFileInfo)
+		if compressed, ok := fi.(GzipBytesProvider); ok {
+			rdGzip := bytes.NewReader(compressed.GzipBytes())
+			// all gzipped static files (from bindata) are managed by Gitea, so we can make sure every file has the correct ext name
+			// then we can get the correct Content-Type, we do not need to do http.DetectContentType on the decompressed data
+			if w.Header().Get("Content-Type") == "" {
+				w.Header().Set("Content-Type", "application/octet-stream")
+			}
+			w.Header().Set("Content-Encoding", "gzip")
+			http.ServeContent(w, req, fi.Name(), modtime, rdGzip)
+			return
+		}
+	}
+
+	http.ServeContent(w, req, fi.Name(), modtime, content)
+	return
+}
diff --git a/modules/public/serve_dynamic.go b/modules/public/serve_dynamic.go
index cd74ee5743..a668b17c34 100644
--- a/modules/public/serve_dynamic.go
+++ b/modules/public/serve_dynamic.go
@@ -6,17 +6,10 @@
 package public
 
 import (
-	"io"
-	"net/http"
-	"os"
-	"time"
+	"code.gitea.io/gitea/modules/assetfs"
+	"code.gitea.io/gitea/modules/setting"
 )
 
-func fileSystem(dir string) http.FileSystem {
-	return http.Dir(dir)
-}
-
-// serveContent serve http content
-func serveContent(w http.ResponseWriter, req *http.Request, fi os.FileInfo, modtime time.Time, content io.ReadSeeker) {
-	http.ServeContent(w, req, fi.Name(), modtime, content)
+func BuiltinAssets() *assetfs.Layer {
+	return assetfs.Local("builtin(static)", setting.StaticRootPath, "public")
 }
diff --git a/modules/public/serve_static.go b/modules/public/serve_static.go
index e85ca79253..e79085021e 100644
--- a/modules/public/serve_static.go
+++ b/modules/public/serve_static.go
@@ -6,75 +6,19 @@
 package public
 
 import (
-	"bytes"
-	"io"
-	"net/http"
-	"os"
-	"path/filepath"
 	"time"
 
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/timeutil"
 )
 
+var _ GzipBytesProvider = (*vfsgen۰CompressedFileInfo)(nil)
+
 // GlobalModTime provide a global mod time for embedded asset files
 func GlobalModTime(filename string) time.Time {
 	return timeutil.GetExecutableModTime()
 }
 
-func fileSystem(dir string) http.FileSystem {
-	return Assets
-}
-
-func Asset(name string) ([]byte, error) {
-	f, err := Assets.Open("/" + name)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	return io.ReadAll(f)
-}
-
-func AssetNames() []string {
-	realFS := Assets.(vfsgen۰FS)
-	results := make([]string, 0, len(realFS))
-	for k := range realFS {
-		results = append(results, k[1:])
-	}
-	return results
-}
-
-func AssetIsDir(name string) (bool, error) {
-	if f, err := Assets.Open("/" + name); err != nil {
-		return false, err
-	} else {
-		defer f.Close()
-		if fi, err := f.Stat(); err != nil {
-			return false, err
-		} else {
-			return fi.IsDir(), nil
-		}
-	}
-}
-
-// serveContent serve http content
-func serveContent(w http.ResponseWriter, req *http.Request, fi os.FileInfo, modtime time.Time, content io.ReadSeeker) {
-	encodings := parseAcceptEncoding(req.Header.Get("Accept-Encoding"))
-	if encodings.Contains("gzip") {
-		if cf, ok := fi.(*vfsgen۰CompressedFileInfo); ok {
-			rdGzip := bytes.NewReader(cf.GzipBytes())
-			// all static files are managed by Gitea, so we can make sure every file has the correct ext name
-			// then we can get the correct Content-Type, we do not need to do http.DetectContentType on the decompressed data
-			mimeType := detectWellKnownMimeType(filepath.Ext(fi.Name()))
-			if mimeType == "" {
-				mimeType = "application/octet-stream"
-			}
-			w.Header().Set("Content-Type", mimeType)
-			w.Header().Set("Content-Encoding", "gzip")
-			http.ServeContent(w, req, fi.Name(), modtime, rdGzip)
-			return
-		}
-	}
-
-	http.ServeContent(w, req, fi.Name(), modtime, content)
-	return
+func BuiltinAssets() *assetfs.Layer {
+	return assetfs.Bindata("builtin(bindata)", Assets)
 }
diff --git a/modules/repository/init.go b/modules/repository/init.go
index 38dd8a0c4f..cb353f2496 100644
--- a/modules/repository/init.go
+++ b/modules/repository/init.go
@@ -79,7 +79,7 @@ func LoadRepoConfig() error {
 	typeFiles := make([]optionFileList, len(types))
 	for i, t := range types {
 		var err error
-		if typeFiles[i].all, err = options.Dir(t); err != nil {
+		if typeFiles[i].all, err = options.AssetFS().ListFiles(t, true); err != nil {
 			return fmt.Errorf("failed to list %s files: %w", t, err)
 		}
 		sort.Strings(typeFiles[i].all)
diff --git a/modules/setting/asset_dynamic.go b/modules/setting/asset_dynamic.go
new file mode 100644
index 0000000000..2eb2883373
--- /dev/null
+++ b/modules/setting/asset_dynamic.go
@@ -0,0 +1,8 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build !bindata
+
+package setting
+
+const HasBuiltinBindata = false
diff --git a/modules/setting/asset_static.go b/modules/setting/asset_static.go
new file mode 100644
index 0000000000..889fca9342
--- /dev/null
+++ b/modules/setting/asset_static.go
@@ -0,0 +1,8 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+//go:build bindata
+
+package setting
+
+const HasBuiltinBindata = true
diff --git a/modules/svg/discover_bindata.go b/modules/svg/discover_bindata.go
deleted file mode 100644
index b6abd294f1..0000000000
--- a/modules/svg/discover_bindata.go
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2020 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-//go:build bindata
-
-package svg
-
-import (
-	"path/filepath"
-
-	"code.gitea.io/gitea/modules/public"
-)
-
-// Discover returns a map of discovered SVG icons in bindata
-func Discover() map[string]string {
-	svgs := make(map[string]string)
-
-	for _, file := range public.AssetNames() {
-		matched, _ := filepath.Match("img/svg/*.svg", file)
-		if matched {
-			content, err := public.Asset(file)
-			if err == nil {
-				filename := filepath.Base(file)
-				svgs[filename[:len(filename)-4]] = string(content)
-			}
-		}
-	}
-
-	return svgs
-}
diff --git a/modules/svg/discover_nobindata.go b/modules/svg/discover_nobindata.go
deleted file mode 100644
index da7ab7b98f..0000000000
--- a/modules/svg/discover_nobindata.go
+++ /dev/null
@@ -1,29 +0,0 @@
-// Copyright 2020 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-//go:build !bindata
-
-package svg
-
-import (
-	"os"
-	"path/filepath"
-
-	"code.gitea.io/gitea/modules/setting"
-)
-
-// Discover returns a map of discovered SVG icons in the file system
-func Discover() map[string]string {
-	svgs := make(map[string]string)
-
-	files, _ := filepath.Glob(filepath.Join(setting.StaticRootPath, "public", "img", "svg", "*.svg"))
-	for _, file := range files {
-		content, err := os.ReadFile(file)
-		if err == nil {
-			filename := filepath.Base(file)
-			svgs[filename[:len(filename)-4]] = string(content)
-		}
-	}
-
-	return svgs
-}
diff --git a/modules/svg/svg.go b/modules/svg/svg.go
index b74ee35358..071340764e 100644
--- a/modules/svg/svg.go
+++ b/modules/svg/svg.go
@@ -6,15 +6,18 @@ package svg
 import (
 	"fmt"
 	"html/template"
+	"path"
 	"regexp"
 	"strings"
 
 	"code.gitea.io/gitea/modules/html"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/public"
 )
 
 var (
 	// SVGs contains discovered SVGs
-	SVGs map[string]string
+	SVGs = map[string]string{}
 
 	widthRe  = regexp.MustCompile(`width="[0-9]+?"`)
 	heightRe = regexp.MustCompile(`height="[0-9]+?"`)
@@ -23,17 +26,29 @@ var (
 const defaultSize = 16
 
 // Init discovers SVGs and populates the `SVGs` variable
-func Init() {
-	SVGs = Discover()
+func Init() error {
+	files, err := public.AssetFS().ListFiles("img/svg")
+	if err != nil {
+		return err
+	}
 
 	// Remove `xmlns` because inline SVG does not need it
-	r := regexp.MustCompile(`(<svg\b[^>]*?)\s+xmlns="[^"]*"`)
-	for name, svg := range SVGs {
-		SVGs[name] = r.ReplaceAllString(svg, "$1")
+	reXmlns := regexp.MustCompile(`(<svg\b[^>]*?)\s+xmlns="[^"]*"`)
+	for _, file := range files {
+		if path.Ext(file) != ".svg" {
+			continue
+		}
+		bs, err := public.AssetFS().ReadFile("img/svg", file)
+		if err != nil {
+			log.Error("Failed to read SVG file %s: %v", file, err)
+		} else {
+			SVGs[file[:len(file)-4]] = reXmlns.ReplaceAllString(string(bs), "$1")
+		}
 	}
+	return nil
 }
 
-// Render render icons - arguments icon name (string), size (int), class (string)
+// RenderHTML renders icons - arguments icon name (string), size (int), class (string)
 func RenderHTML(icon string, others ...interface{}) template.HTML {
 	size, class := html.ParseSizeAndClass(defaultSize, "", others...)
 
diff --git a/modules/templates/base.go b/modules/templates/base.go
index e0f8350afb..e95ce31cfc 100644
--- a/modules/templates/base.go
+++ b/modules/templates/base.go
@@ -4,14 +4,10 @@
 package templates
 
 import (
-	"fmt"
-	"io/fs"
-	"os"
-	"path/filepath"
 	"strings"
 	"time"
 
-	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
 )
@@ -47,81 +43,30 @@ func BaseVars() Vars {
 	}
 }
 
-func getDirTemplateAssetNames(dir string) []string {
-	return getDirAssetNames(dir, false)
+func AssetFS() *assetfs.LayeredFS {
+	return assetfs.Layered(CustomAssets(), BuiltinAssets())
 }
 
-func getDirAssetNames(dir string, mailer bool) []string {
-	var tmpls []string
-
-	if mailer {
-		dir += filepath.Join(dir, "mail")
-	}
-	f, err := os.Stat(dir)
-	if err != nil {
-		if os.IsNotExist(err) {
-			return tmpls
-		}
-		log.Warn("Unable to check if templates dir %s is a directory. Error: %v", dir, err)
-		return tmpls
-	}
-	if !f.IsDir() {
-		log.Warn("Templates dir %s is a not directory.", dir)
-		return tmpls
-	}
+func CustomAssets() *assetfs.Layer {
+	return assetfs.Local("custom", setting.CustomPath, "templates")
+}
 
-	files, err := util.StatDir(dir)
+func ListWebTemplateAssetNames(assets *assetfs.LayeredFS) ([]string, error) {
+	files, err := assets.ListAllFiles(".", true)
 	if err != nil {
-		log.Warn("Failed to read %s templates dir. %v", dir, err)
-		return tmpls
+		return nil, err
 	}
-
-	prefix := "templates/"
-	if mailer {
-		prefix += "mail/"
-	}
-	for _, filePath := range files {
-		if !mailer && strings.HasPrefix(filePath, "mail/") {
-			continue
-		}
-
-		if !strings.HasSuffix(filePath, ".tmpl") {
-			continue
-		}
-
-		tmpls = append(tmpls, prefix+filePath)
-	}
-	return tmpls
+	return util.SliceRemoveAllFunc(files, func(file string) bool {
+		return strings.HasPrefix(file, "mail/") || !strings.HasSuffix(file, ".tmpl")
+	}), nil
 }
 
-func walkAssetDir(root string, skipMail bool, callback func(path, name string, d fs.DirEntry, err error) error) error {
-	mailRoot := filepath.Join(root, "mail")
-	if err := filepath.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
-		name := path[len(root):]
-		if len(name) > 0 && name[0] == '/' {
-			name = name[1:]
-		}
-		if err != nil {
-			if os.IsNotExist(err) {
-				return callback(path, name, d, err)
-			}
-			return err
-		}
-		if skipMail && path == mailRoot && d.IsDir() {
-			return fs.SkipDir
-		}
-		if util.CommonSkip(d.Name()) {
-			if d.IsDir() {
-				return fs.SkipDir
-			}
-			return nil
-		}
-		if strings.HasSuffix(d.Name(), ".tmpl") || d.IsDir() {
-			return callback(path, name, d, err)
-		}
-		return nil
-	}); err != nil && !os.IsNotExist(err) {
-		return fmt.Errorf("unable to get files for template assets in %s: %w", root, err)
+func ListMailTemplateAssetNames(assets *assetfs.LayeredFS) ([]string, error) {
+	files, err := assets.ListAllFiles(".", true)
+	if err != nil {
+		return nil, err
 	}
-	return nil
+	return util.SliceRemoveAllFunc(files, func(file string) bool {
+		return !strings.HasPrefix(file, "mail/") || !strings.HasSuffix(file, ".tmpl")
+	}), nil
 }
diff --git a/modules/templates/dynamic.go b/modules/templates/dynamic.go
index 2f4f542e72..e1babd83c9 100644
--- a/modules/templates/dynamic.go
+++ b/modules/templates/dynamic.go
@@ -6,76 +6,10 @@
 package templates
 
 import (
-	"io/fs"
-	"os"
-	"path/filepath"
-
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/setting"
 )
 
-// GetAsset returns asset content via name
-func GetAsset(name string) ([]byte, error) {
-	bs, err := os.ReadFile(filepath.Join(setting.CustomPath, name))
-	if err != nil && !os.IsNotExist(err) {
-		return nil, err
-	} else if err == nil {
-		return bs, nil
-	}
-
-	return os.ReadFile(filepath.Join(setting.StaticRootPath, name))
-}
-
-// GetAssetFilename returns the filename of the provided asset
-func GetAssetFilename(name string) (string, error) {
-	filename := filepath.Join(setting.CustomPath, name)
-	_, err := os.Stat(filename)
-	if err != nil && !os.IsNotExist(err) {
-		return filename, err
-	} else if err == nil {
-		return filename, nil
-	}
-
-	filename = filepath.Join(setting.StaticRootPath, name)
-	_, err = os.Stat(filename)
-	return filename, err
-}
-
-// walkTemplateFiles calls a callback for each template asset
-func walkTemplateFiles(callback func(path, name string, d fs.DirEntry, err error) error) error {
-	if err := walkAssetDir(filepath.Join(setting.CustomPath, "templates"), true, callback); err != nil && !os.IsNotExist(err) {
-		return err
-	}
-	if err := walkAssetDir(filepath.Join(setting.StaticRootPath, "templates"), true, callback); err != nil && !os.IsNotExist(err) {
-		return err
-	}
-	return nil
-}
-
-// GetTemplateAssetNames returns list of template names
-func GetTemplateAssetNames() []string {
-	tmpls := getDirTemplateAssetNames(filepath.Join(setting.CustomPath, "templates"))
-	tmpls2 := getDirTemplateAssetNames(filepath.Join(setting.StaticRootPath, "templates"))
-	return append(tmpls, tmpls2...)
-}
-
-func walkMailerTemplates(callback func(path, name string, d fs.DirEntry, err error) error) error {
-	if err := walkAssetDir(filepath.Join(setting.StaticRootPath, "templates", "mail"), false, callback); err != nil && !os.IsNotExist(err) {
-		return err
-	}
-	if err := walkAssetDir(filepath.Join(setting.CustomPath, "templates", "mail"), false, callback); err != nil && !os.IsNotExist(err) {
-		return err
-	}
-	return nil
-}
-
-// BuiltinAsset will read the provided asset from the embedded assets
-// (This always returns os.ErrNotExist)
-func BuiltinAsset(name string) ([]byte, error) {
-	return nil, os.ErrNotExist
-}
-
-// BuiltinAssetNames returns the names of the embedded assets
-// (This always returns nil)
-func BuiltinAssetNames() []string {
-	return nil
+func BuiltinAssets() *assetfs.Layer {
+	return assetfs.Local("builtin(static)", setting.StaticRootPath, "templates")
 }
diff --git a/modules/templates/htmlrenderer.go b/modules/templates/htmlrenderer.go
index 4e7b09a9ec..26dd365e4c 100644
--- a/modules/templates/htmlrenderer.go
+++ b/modules/templates/htmlrenderer.go
@@ -21,7 +21,6 @@ import (
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/util"
-	"code.gitea.io/gitea/modules/watcher"
 )
 
 var (
@@ -66,20 +65,23 @@ func (h *HTMLRender) TemplateLookup(name string) (*template.Template, error) {
 }
 
 func (h *HTMLRender) CompileTemplates() error {
-	dirPrefix := "templates/"
 	extSuffix := ".tmpl"
 	tmpls := template.New("")
-	for _, path := range GetTemplateAssetNames() {
-		if !strings.HasSuffix(path, extSuffix) {
+	assets := AssetFS()
+	files, err := ListWebTemplateAssetNames(assets)
+	if err != nil {
+		return nil
+	}
+	for _, file := range files {
+		if !strings.HasSuffix(file, extSuffix) {
 			continue
 		}
-		name := strings.TrimPrefix(path, dirPrefix)
-		name = strings.TrimSuffix(name, extSuffix)
+		name := strings.TrimSuffix(file, extSuffix)
 		tmpl := tmpls.New(filepath.ToSlash(name))
 		for _, fm := range NewFuncMap() {
 			tmpl.Funcs(fm)
 		}
-		buf, err := GetAsset(path)
+		buf, err := assets.ReadFile(file)
 		if err != nil {
 			return err
 		}
@@ -112,13 +114,10 @@ func HTMLRenderer(ctx context.Context) (context.Context, *HTMLRender) {
 		log.Fatal("HTMLRenderer error: %v", err)
 	}
 	if !setting.IsProd {
-		watcher.CreateWatcher(ctx, "HTML Templates", &watcher.CreateWatcherOpts{
-			PathsCallback: walkTemplateFiles,
-			BetweenCallback: func() {
-				if err := renderer.CompileTemplates(); err != nil {
-					log.Error("Template error: %v\n%s", err, log.Stack(2))
-				}
-			},
+		go AssetFS().WatchLocalChanges(ctx, func() {
+			if err := renderer.CompileTemplates(); err != nil {
+				log.Error("Template error: %v\n%s", err, log.Stack(2))
+			}
 		})
 	}
 	return context.WithValue(ctx, rendererKey, renderer), renderer
@@ -138,14 +137,8 @@ func handleGenericTemplateError(err error) (string, []interface{}) {
 	}
 
 	templateName, lineNumberStr, message := groups[1], groups[2], groups[3]
-
-	filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
-	if assetErr != nil {
-		return "", nil
-	}
-
+	filename := fmt.Sprintf("%s (provided by %s)", templateName, AssetFS().GetFileLayerName(templateName+".tmpl"))
 	lineNumber, _ := strconv.Atoi(lineNumberStr)
-
 	line := GetLineFromTemplate(templateName, lineNumber, "", -1)
 
 	return "PANIC: Unable to compile templates!\n%s in template file %s at line %d:\n\n%s\nStacktrace:\n\n%s", []interface{}{message, filename, lineNumber, log.NewColoredValue(line, log.Reset), log.Stack(2)}
@@ -158,16 +151,9 @@ func handleNotDefinedPanicError(err error) (string, []interface{}) {
 	}
 
 	templateName, lineNumberStr, functionName := groups[1], groups[2], groups[3]
-
 	functionName, _ = strconv.Unquote(`"` + functionName + `"`)
-
-	filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
-	if assetErr != nil {
-		return "", nil
-	}
-
+	filename := fmt.Sprintf("%s (provided by %s)", templateName, AssetFS().GetFileLayerName(templateName+".tmpl"))
 	lineNumber, _ := strconv.Atoi(lineNumberStr)
-
 	line := GetLineFromTemplate(templateName, lineNumber, functionName, -1)
 
 	return "PANIC: Unable to compile templates!\nUndefined function %q in template file %s at line %d:\n\n%s", []interface{}{functionName, filename, lineNumber, log.NewColoredValue(line, log.Reset)}
@@ -181,14 +167,8 @@ func handleUnexpected(err error) (string, []interface{}) {
 
 	templateName, lineNumberStr, unexpected := groups[1], groups[2], groups[3]
 	unexpected, _ = strconv.Unquote(`"` + unexpected + `"`)
-
-	filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
-	if assetErr != nil {
-		return "", nil
-	}
-
+	filename := fmt.Sprintf("%s (provided by %s)", templateName, AssetFS().GetFileLayerName(templateName+".tmpl"))
 	lineNumber, _ := strconv.Atoi(lineNumberStr)
-
 	line := GetLineFromTemplate(templateName, lineNumber, unexpected, -1)
 
 	return "PANIC: Unable to compile templates!\nUnexpected %q in template file %s at line %d:\n\n%s", []interface{}{unexpected, filename, lineNumber, log.NewColoredValue(line, log.Reset)}
@@ -201,14 +181,8 @@ func handleExpectedEnd(err error) (string, []interface{}) {
 	}
 
 	templateName, lineNumberStr, unexpected := groups[1], groups[2], groups[3]
-
-	filename, assetErr := GetAssetFilename("templates/" + templateName + ".tmpl")
-	if assetErr != nil {
-		return "", nil
-	}
-
+	filename := fmt.Sprintf("%s (provided by %s)", templateName, AssetFS().GetFileLayerName(templateName+".tmpl"))
 	lineNumber, _ := strconv.Atoi(lineNumberStr)
-
 	line := GetLineFromTemplate(templateName, lineNumber, unexpected, -1)
 
 	return "PANIC: Unable to compile templates!\nMissing end with unexpected %q in template file %s at line %d:\n\n%s", []interface{}{unexpected, filename, lineNumber, log.NewColoredValue(line, log.Reset)}
@@ -218,7 +192,7 @@ const dashSeparator = "---------------------------------------------------------
 
 // GetLineFromTemplate returns a line from a template with some context
 func GetLineFromTemplate(templateName string, targetLineNum int, target string, position int) string {
-	bs, err := GetAsset("templates/" + templateName + ".tmpl")
+	bs, err := AssetFS().ReadFile(templateName + ".tmpl")
 	if err != nil {
 		return fmt.Sprintf("(unable to read template file: %v)", err)
 	}
diff --git a/modules/templates/mailer.go b/modules/templates/mailer.go
index d0c49e1025..280ac0e587 100644
--- a/modules/templates/mailer.go
+++ b/modules/templates/mailer.go
@@ -6,15 +6,12 @@ package templates
 import (
 	"context"
 	"html/template"
-	"io/fs"
-	"os"
 	"strings"
 	texttmpl "text/template"
 
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/log"
 	"code.gitea.io/gitea/modules/setting"
-	"code.gitea.io/gitea/modules/watcher"
 )
 
 // mailSubjectTextFuncMap returns functions for injecting to text templates, it's only used for mail subject
@@ -62,54 +59,23 @@ func Mailer(ctx context.Context) (*texttmpl.Template, *template.Template) {
 		bodyTemplates.Funcs(funcs)
 	}
 
+	assetFS := AssetFS()
 	refreshTemplates := func() {
-		for _, assetPath := range BuiltinAssetNames() {
-			if !strings.HasPrefix(assetPath, "mail/") {
-				continue
-			}
-
-			if !strings.HasSuffix(assetPath, ".tmpl") {
-				continue
-			}
-
-			content, err := BuiltinAsset(assetPath)
-			if err != nil {
-				log.Warn("Failed to read embedded %s template. %v", assetPath, err)
-				continue
-			}
-
-			assetName := strings.TrimPrefix(strings.TrimSuffix(assetPath, ".tmpl"), "mail/")
-
-			log.Trace("Adding built-in mailer template for %s", assetName)
-			buildSubjectBodyTemplate(subjectTemplates,
-				bodyTemplates,
-				assetName,
-				content)
+		assetPaths, err := ListMailTemplateAssetNames(assetFS)
+		if err != nil {
+			log.Error("Failed to list mail templates: %v", err)
+			return
 		}
 
-		if err := walkMailerTemplates(func(path, name string, d fs.DirEntry, err error) error {
-			if err != nil {
-				return err
-			}
-			if d.IsDir() {
-				return nil
-			}
-
-			content, err := os.ReadFile(path)
+		for _, assetPath := range assetPaths {
+			content, layerName, err := assetFS.ReadLayeredFile(assetPath)
 			if err != nil {
-				log.Warn("Failed to read custom %s template. %v", path, err)
-				return nil
+				log.Warn("Failed to read mail template %s by %s: %v", assetPath, layerName, err)
+				continue
 			}
-
-			assetName := strings.TrimSuffix(name, ".tmpl")
-			log.Trace("Adding mailer template for %s from %q", assetName, path)
-			buildSubjectBodyTemplate(subjectTemplates,
-				bodyTemplates,
-				assetName,
-				content)
-			return nil
-		}); err != nil && !os.IsNotExist(err) {
-			log.Warn("Error whilst walking mailer templates directories. %v", err)
+			tmplName := strings.TrimPrefix(strings.TrimSuffix(assetPath, ".tmpl"), "mail/")
+			log.Trace("Adding mail template %s: %s by %s", tmplName, assetPath, layerName)
+			buildSubjectBodyTemplate(subjectTemplates, bodyTemplates, tmplName, content)
 		}
 	}
 
@@ -118,10 +84,7 @@ func Mailer(ctx context.Context) (*texttmpl.Template, *template.Template) {
 	if !setting.IsProd {
 		// Now subjectTemplates and bodyTemplates are both synchronized
 		// thus it is safe to call refresh from a different goroutine
-		watcher.CreateWatcher(ctx, "Mailer Templates", &watcher.CreateWatcherOpts{
-			PathsCallback:   walkMailerTemplates,
-			BetweenCallback: refreshTemplates,
-		})
+		go assetFS.WatchLocalChanges(ctx, refreshTemplates)
 	}
 
 	return subjectTemplates, bodyTemplates
diff --git a/modules/templates/static.go b/modules/templates/static.go
index 7ebb327ae6..b5a7e561ec 100644
--- a/modules/templates/static.go
+++ b/modules/templates/static.go
@@ -6,114 +6,17 @@
 package templates
 
 import (
-	"html/template"
-	"io"
-	"io/fs"
-	"os"
-	"path"
-	"path/filepath"
-	"strings"
-	texttmpl "text/template"
 	"time"
 
-	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/assetfs"
 	"code.gitea.io/gitea/modules/timeutil"
 )
 
-var (
-	subjectTemplates = texttmpl.New("")
-	bodyTemplates    = template.New("")
-)
-
 // GlobalModTime provide a global mod time for embedded asset files
 func GlobalModTime(filename string) time.Time {
 	return timeutil.GetExecutableModTime()
 }
 
-// GetAssetFilename returns the filename of the provided asset
-func GetAssetFilename(name string) (string, error) {
-	filename := filepath.Join(setting.CustomPath, name)
-	_, err := os.Stat(filename)
-	if err != nil && !os.IsNotExist(err) {
-		return name, err
-	} else if err == nil {
-		return filename, nil
-	}
-	return "(builtin) " + name, nil
-}
-
-// GetAsset get a special asset, only for chi
-func GetAsset(name string) ([]byte, error) {
-	bs, err := os.ReadFile(filepath.Join(setting.CustomPath, name))
-	if err != nil && !os.IsNotExist(err) {
-		return nil, err
-	} else if err == nil {
-		return bs, nil
-	}
-	return BuiltinAsset(strings.TrimPrefix(name, "templates/"))
-}
-
-// GetFiles calls a callback for each template asset
-func walkTemplateFiles(callback func(path, name string, d fs.DirEntry, err error) error) error {
-	if err := walkAssetDir(filepath.Join(setting.CustomPath, "templates"), true, callback); err != nil && !os.IsNotExist(err) {
-		return err
-	}
-	return nil
-}
-
-// GetTemplateAssetNames only for chi
-func GetTemplateAssetNames() []string {
-	realFS := Assets.(vfsgen۰FS)
-	tmpls := make([]string, 0, len(realFS))
-	for k := range realFS {
-		if strings.HasPrefix(k, "/mail/") {
-			continue
-		}
-		tmpls = append(tmpls, "templates/"+k[1:])
-	}
-
-	customDir := path.Join(setting.CustomPath, "templates")
-	customTmpls := getDirTemplateAssetNames(customDir)
-	return append(tmpls, customTmpls...)
-}
-
-func walkMailerTemplates(callback func(path, name string, d fs.DirEntry, err error) error) error {
-	if err := walkAssetDir(filepath.Join(setting.CustomPath, "templates", "mail"), false, callback); err != nil && !os.IsNotExist(err) {
-		return err
-	}
-	return nil
-}
-
-// BuiltinAsset reads the provided asset from the builtin embedded assets
-func BuiltinAsset(name string) ([]byte, error) {
-	f, err := Assets.Open("/" + name)
-	if err != nil {
-		return nil, err
-	}
-	defer f.Close()
-	return io.ReadAll(f)
-}
-
-// BuiltinAssetNames returns the names of the built-in embedded assets
-func BuiltinAssetNames() []string {
-	realFS := Assets.(vfsgen۰FS)
-	results := make([]string, 0, len(realFS))
-	for k := range realFS {
-		results = append(results, k[1:])
-	}
-	return results
-}
-
-// BuiltinAssetIsDir returns if a provided asset is a directory
-func BuiltinAssetIsDir(name string) (bool, error) {
-	if f, err := Assets.Open("/" + name); err != nil {
-		return false, err
-	} else {
-		defer f.Close()
-		if fi, err := f.Stat(); err != nil {
-			return false, err
-		} else {
-			return fi.IsDir(), nil
-		}
-	}
+func BuiltinAssets() *assetfs.Layer {
+	return assetfs.Bindata("builtin(bindata)", Assets)
 }
diff --git a/modules/translation/translation.go b/modules/translation/translation.go
index 3165390c32..331da0f965 100644
--- a/modules/translation/translation.go
+++ b/modules/translation/translation.go
@@ -13,7 +13,6 @@ import (
 	"code.gitea.io/gitea/modules/options"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/translation/i18n"
-	"code.gitea.io/gitea/modules/watcher"
 
 	"golang.org/x/text/language"
 )
@@ -58,7 +57,7 @@ func InitLocales(ctx context.Context) {
 
 	refreshLocales := func() {
 		i18n.ResetDefaultLocales()
-		localeNames, err := options.Dir("locale")
+		localeNames, err := options.AssetFS().ListFiles("locale", true)
 		if err != nil {
 			log.Fatal("Failed to list locale files: %v", err)
 		}
@@ -118,13 +117,10 @@ func InitLocales(ctx context.Context) {
 	})
 
 	if !setting.IsProd {
-		watcher.CreateWatcher(ctx, "Locales", &watcher.CreateWatcherOpts{
-			PathsCallback: options.WalkLocales,
-			BetweenCallback: func() {
-				lock.Lock()
-				defer lock.Unlock()
-				refreshLocales()
-			},
+		go options.AssetFS().WatchLocalChanges(ctx, func() {
+			lock.Lock()
+			defer lock.Unlock()
+			refreshLocales()
 		})
 	}
 }
diff --git a/modules/util/path.go b/modules/util/path.go
index 37d06e9813..1a68bc7488 100644
--- a/modules/util/path.go
+++ b/modules/util/path.go
@@ -74,29 +74,28 @@ const pathSeparator = string(os.PathSeparator)
 //
 //	{`/foo`, ``, `bar`} => `/foo/bar`
 //	{`/foo`, `..`, `bar`} => `/foo/bar`
-func FilePathJoinAbs(elem ...string) string {
-	elems := make([]string, len(elem))
+func FilePathJoinAbs(base string, sub ...string) string {
+	elems := make([]string, 1, len(sub)+1)
 
-	// POISX filesystem can have `\` in file names. Windows: `\` and `/` are both used for path separators
+	// POSIX filesystem can have `\` in file names. Windows: `\` and `/` are both used for path separators
 	// to keep the behavior consistent, we do not allow `\` in file names, replace all `\` with `/`
 	if isOSWindows() {
-		elems[0] = filepath.Clean(elem[0])
+		elems[0] = filepath.Clean(base)
 	} else {
-		elems[0] = filepath.Clean(strings.ReplaceAll(elem[0], "\\", pathSeparator))
+		elems[0] = filepath.Clean(strings.ReplaceAll(base, "\\", pathSeparator))
 	}
 	if !filepath.IsAbs(elems[0]) {
 		// This shouldn't happen. If there is really necessary to pass in relative path, return the full path with filepath.Abs() instead
 		panic(fmt.Sprintf("FilePathJoinAbs: %q (for path %v) is not absolute, do not guess a relative path based on current working directory", elems[0], elems))
 	}
-
-	for i := 1; i < len(elem); i++ {
-		if elem[i] == "" {
+	for _, s := range sub {
+		if s == "" {
 			continue
 		}
 		if isOSWindows() {
-			elems[i] = filepath.Clean(pathSeparator + elem[i])
+			elems = append(elems, filepath.Clean(pathSeparator+s))
 		} else {
-			elems[i] = filepath.Clean(pathSeparator + strings.ReplaceAll(elem[i], "\\", pathSeparator))
+			elems = append(elems, filepath.Clean(pathSeparator+strings.ReplaceAll(s, "\\", pathSeparator)))
 		}
 	}
 	// the elems[0] must be an absolute path, just join them together
diff --git a/modules/util/path_test.go b/modules/util/path_test.go
index 1d27c9bf0c..6a38bf4ace 100644
--- a/modules/util/path_test.go
+++ b/modules/util/path_test.go
@@ -207,6 +207,6 @@ func TestCleanPath(t *testing.T) {
 		}
 	}
 	for _, c := range cases {
-		assert.Equal(t, c.expected, FilePathJoinAbs(c.elems...), "case: %v", c.elems)
+		assert.Equal(t, c.expected, FilePathJoinAbs(c.elems[0], c.elems[1:]...), "case: %v", c.elems)
 	}
 }
diff --git a/modules/util/timer.go b/modules/util/timer.go
index daf96bda7e..d598fde73a 100644
--- a/modules/util/timer.go
+++ b/modules/util/timer.go
@@ -4,6 +4,7 @@
 package util
 
 import (
+	"sync"
 	"time"
 )
 
@@ -18,3 +19,30 @@ func StopTimer(t *time.Timer) bool {
 	}
 	return stopped
 }
+
+func Debounce(d time.Duration) func(f func()) {
+	type debouncer struct {
+		mu sync.Mutex
+		t  *time.Timer
+	}
+	db := &debouncer{}
+
+	return func(f func()) {
+		db.mu.Lock()
+		defer db.mu.Unlock()
+
+		if db.t != nil {
+			db.t.Stop()
+		}
+		var trigger *time.Timer
+		trigger = time.AfterFunc(d, func() {
+			db.mu.Lock()
+			defer db.mu.Unlock()
+			if trigger == db.t {
+				f()
+				db.t = nil
+			}
+		})
+		db.t = trigger
+	}
+}
diff --git a/modules/util/timer_test.go b/modules/util/timer_test.go
new file mode 100644
index 0000000000..602800c248
--- /dev/null
+++ b/modules/util/timer_test.go
@@ -0,0 +1,30 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package util
+
+import (
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDebounce(t *testing.T) {
+	var c int64
+	d := Debounce(50 * time.Millisecond)
+	d(func() { atomic.AddInt64(&c, 1) })
+	assert.EqualValues(t, 0, atomic.LoadInt64(&c))
+	d(func() { atomic.AddInt64(&c, 1) })
+	d(func() { atomic.AddInt64(&c, 1) })
+	time.Sleep(100 * time.Millisecond)
+	assert.EqualValues(t, 1, atomic.LoadInt64(&c))
+	d(func() { atomic.AddInt64(&c, 1) })
+	assert.EqualValues(t, 1, atomic.LoadInt64(&c))
+	d(func() { atomic.AddInt64(&c, 1) })
+	d(func() { atomic.AddInt64(&c, 1) })
+	d(func() { atomic.AddInt64(&c, 1) })
+	time.Sleep(100 * time.Millisecond)
+	assert.EqualValues(t, 2, atomic.LoadInt64(&c))
+}
diff --git a/modules/watcher/watcher.go b/modules/watcher/watcher.go
deleted file mode 100644
index 75d062d7aa..0000000000
--- a/modules/watcher/watcher.go
+++ /dev/null
@@ -1,114 +0,0 @@
-// Copyright 2022 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-package watcher
-
-import (
-	"context"
-	"io/fs"
-	"os"
-
-	"code.gitea.io/gitea/modules/log"
-	"code.gitea.io/gitea/modules/process"
-
-	"github.com/fsnotify/fsnotify"
-)
-
-// CreateWatcherOpts are options to configure the watcher
-type CreateWatcherOpts struct {
-	// PathsCallback is used to set the required paths to watch
-	PathsCallback func(func(path, name string, d fs.DirEntry, err error) error) error
-
-	// BeforeCallback is called before any files are watched
-	BeforeCallback func()
-
-	// Between Callback is called between after a watched event has occurred
-	BetweenCallback func()
-
-	// AfterCallback is called as this watcher ends
-	AfterCallback func()
-}
-
-// CreateWatcher creates a watcher labelled with the provided description and running with the provided options.
-// The created watcher will create a subcontext from the provided ctx and register it with the process manager.
-func CreateWatcher(ctx context.Context, desc string, opts *CreateWatcherOpts) {
-	go run(ctx, desc, opts)
-}
-
-func run(ctx context.Context, desc string, opts *CreateWatcherOpts) {
-	if opts.BeforeCallback != nil {
-		opts.BeforeCallback()
-	}
-	if opts.AfterCallback != nil {
-		defer opts.AfterCallback()
-	}
-	ctx, _, finished := process.GetManager().AddTypedContext(ctx, "Watcher: "+desc, process.SystemProcessType, true)
-	defer finished()
-
-	log.Trace("Watcher loop starting for %s", desc)
-	defer log.Trace("Watcher loop ended for %s", desc)
-
-	watcher, err := fsnotify.NewWatcher()
-	if err != nil {
-		log.Error("Unable to create watcher for %s: %v", desc, err)
-		return
-	}
-	if err := opts.PathsCallback(func(path, _ string, d fs.DirEntry, err error) error {
-		if err != nil && !os.IsNotExist(err) {
-			return err
-		}
-		log.Trace("Watcher: %s watching %q", desc, path)
-		_ = watcher.Add(path)
-		return nil
-	}); err != nil {
-		log.Error("Unable to create watcher for %s: %v", desc, err)
-		_ = watcher.Close()
-		return
-	}
-
-	// Note we don't call the BetweenCallback here
-
-	for {
-		select {
-		case event, ok := <-watcher.Events:
-			if !ok {
-				_ = watcher.Close()
-				return
-			}
-			log.Debug("Watched file for %s had event: %v", desc, event)
-		case err, ok := <-watcher.Errors:
-			if !ok {
-				_ = watcher.Close()
-				return
-			}
-			log.Error("Error whilst watching files for %s: %v", desc, err)
-		case <-ctx.Done():
-			_ = watcher.Close()
-			return
-		}
-
-		// Recreate the watcher - only call the BetweenCallback after the new watcher is set-up
-		_ = watcher.Close()
-		watcher, err = fsnotify.NewWatcher()
-		if err != nil {
-			log.Error("Unable to create watcher for %s: %v", desc, err)
-			return
-		}
-		if err := opts.PathsCallback(func(path, _ string, _ fs.DirEntry, err error) error {
-			if err != nil {
-				return err
-			}
-			_ = watcher.Add(path)
-			return nil
-		}); err != nil {
-			log.Error("Unable to create watcher for %s: %v", desc, err)
-			_ = watcher.Close()
-			return
-		}
-
-		// Inform our BetweenCallback that there has been an event
-		if opts.BetweenCallback != nil {
-			opts.BetweenCallback()
-		}
-	}
-}