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Diffstat (limited to '')
| -rw-r--r-- | modules/assetfs/layered.go | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/modules/assetfs/layered.go b/modules/assetfs/layered.go new file mode 100644 index 0000000..9678d23 --- /dev/null +++ b/modules/assetfs/layered.go @@ -0,0 +1,256 @@ +// 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/container" + "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) { + fileSet := make(container.Set[string]) + for _, layer := range l.layers { + infos, err := readDir(layer, name) + if err != nil { + return nil, err + } + for _, info := range infos { + if shouldInclude(info, fileMode...) { + fileSet.Add(info.Name()) + } + } + } + files := fileSet.Values() + 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) { + fileSet := make(container.Set[string]) + 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...) { + fileSet.Add(path) + } + if info.IsDir() { + if err = list(path); err != nil { + return err + } + } + } + } + return nil + } + if err := list(name); err != nil { + return nil, err + } + files := fileSet.Values() + 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 + } + layerDirs = append(layerDirs, ".") + for _, dir := range layerDirs { + if err = watcher.Add(util.FilePathJoinAbs(layer.localPath, dir)); err != nil && !os.IsNotExist(err) { + 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 "" +} |