Golang FileSystem.Lstat方法代码示例

// Glob returns the names of all files matching pattern or nil
// if there is no matching file. The syntax of patterns is the same
// as in path.Match. The pattern may describe hierarchical names such as
// /usr/*/bin/ed.
//
// Glob ignores file system errors such as I/O errors reading directories.
// The only possible returned error is ErrBadPattern, when pattern
// is malformed.
func Glob(fs vfs.FileSystem, pattern string) (matches []string, err error) {
	if !hasMeta(pattern) {
		if _, err = fs.Lstat(pattern); err != nil {
			return nil, nil
		}
		return []string{pattern}, nil
	}

	dir, file := path.Split(pattern)
	switch dir {
	case "":
		dir = "."
	case string(separator):
		// nothing
	default:
		dir = dir[0 : len(dir)-1] // chop off trailing separator
	}

	if !hasMeta(dir) {
		return glob(fs, dir, file, nil)
	}

	var m []string
	m, err = Glob(fs, dir)
	if err != nil {
		return
	}
	for _, d := range m {
		matches, err = glob(fs, d, file, matches)
		if err != nil {
			return
		}
	}
	return
}

// Walk walks the filesystem rooted at root, calling walkFn for each file or
// directory in the filesystem, including root. All errors that arise visiting files
// and directories are filtered by walkFn. The files are walked in lexical
// order.
func Walk(fs vfs.FileSystem, root string, walkFn filepath.WalkFunc) error {
	info, err := fs.Lstat(root)
	if err != nil {
		return walkFn(root, nil, err)
	}
	return walk(fs, root, info, walkFn)
}

// ReadCached reads a Tree's configuration from all of its source unit
// definition files (which may either be in a local VFS rooted at a
// .srclib-cache/<COMMITID> dir, or a remote VFS). It does not read
// the Srcfile; the Srcfile's directives are already accounted for in
// the cached source unit definition files.
//
// bdfs should be a VFS obtained from a call to
// (buildstore.RepoBuildStore).Commit.
func ReadCached(bdfs vfs.FileSystem) (*Tree, error) {
	if _, err := bdfs.Lstat("."); os.IsNotExist(err) {
		return nil, fmt.Errorf("build cache dir does not exist (did you run `srclib config` to create it)?")
	} else if err != nil {
		return nil, err
	}

	// Collect all **/*.unit.json files.
	var unitFiles []string
	unitSuffix := buildstore.DataTypeSuffix(unit.SourceUnit{})
	w := fs.WalkFS(".", rwvfs.Walkable(rwvfs.ReadOnly(bdfs)))
	for w.Step() {
		if err := w.Err(); err != nil {
			return nil, err
		}
		if path := w.Path(); strings.HasSuffix(path, unitSuffix) {
			unitFiles = append(unitFiles, path)
		}
	}

	// Parse units
	sort.Strings(unitFiles)
	units := make([]*unit.SourceUnit, len(unitFiles))
	par := parallel.NewRun(runtime.GOMAXPROCS(0))
	for i_, unitFile_ := range unitFiles {
		i, unitFile := i_, unitFile_
		par.Acquire()
		go func() {
			defer par.Release()
			f, err := bdfs.Open(unitFile)
			if err != nil {
				par.Error(err)
				return
			}
			if err := json.NewDecoder(f).Decode(&units[i]); err != nil {
				f.Close()
				par.Error(err)
				return
			}
			if err := f.Close(); err != nil {
				par.Error(err)
				return
			}
		}()
	}
	if err := par.Wait(); err != nil {
		return nil, err
	}
	return &Tree{SourceUnits: units}, nil
}

// GetFileWithOptions gets a file and observes the options specified
// in opt. If fs implements FileGetter, fs.GetFileWithOptions is
// called; otherwise the options are applied on the client side after
// fetching the whole file.
func GetFileWithOptions(fs vfs.FileSystem, path string, opt GetFileOptions) (*FileWithRange, error) {
	if fg, ok := fs.(FileGetter); ok {
		return fg.GetFileWithOptions(path, opt)
	}

	fi, err := fs.Lstat(path)
	if err != nil {
		return nil, err
	}

	e := newTreeEntry(fi)
	fwr := FileWithRange{TreeEntry: e}

	if fi.Mode().IsDir() {
		ee, err := readDir(fs, path, opt.RecurseSingleSubfolder, true)
		if err != nil {
			return nil, err
		}
		sort.Sort(TreeEntriesByTypeByName(ee))
		e.Entries = ee
	} else if fi.Mode().IsRegular() {
		f, err := fs.Open(path)
		if err != nil {
			return nil, err
		}
		defer f.Close()

		contents, err := ioutil.ReadAll(f)
		if err != nil {
			return nil, err
		}

		e.Contents = contents

		if empty := (GetFileOptions{}); opt != empty {
			fr, _, err := ComputeFileRange(contents, opt)
			if err != nil {
				return nil, err
			}

			// Trim to only requested range.
			e.Contents = e.Contents[fr.StartByte:fr.EndByte]
			fwr.FileRange = *fr
		}
	}

	return &fwr, nil
}

// walk recursively descends path, calling walkFn.
func walk(fs vfs.FileSystem, path string, info os.FileInfo, walkFn filepath.WalkFunc) error {
	err := walkFn(path, info, nil)
	if err != nil {
		if info.IsDir() && err == filepath.SkipDir {
			return nil
		}
		return err
	}

	if !info.IsDir() {
		return nil
	}

	names, err := readDirNames(fs, path)
	if err != nil {
		return walkFn(path, info, err)
	}

	for _, name := range names {
		filename := pathpkg.Join(path, name)
		fileInfo, err := fs.Lstat(filename)
		if err != nil {
			if err := walkFn(filename, fileInfo, err); err != nil && err != filepath.SkipDir {
				return err
			}
		} else {
			err = walk(fs, filename, fileInfo, walkFn)
			if err != nil {
				if !fileInfo.IsDir() || err != filepath.SkipDir {
					return err
				}
			}
		}
	}
	return nil
}