Rename fs package to filesys

pkg/filesys/fsinmemory.go

@@ -0,0 +1,223 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package filesys
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+var _ FileSystem = &fsInMemory{}
+
+// fsInMemory implements FileSystem using a in-memory filesystem
+// primarily for use in tests.
+type fsInMemory struct {
+	m map[string]*fileInMemory
+}
+
+// MakeFsInMemory returns an instance of fsInMemory with no files in it.
+func MakeFsInMemory() FileSystem {
+	result := &fsInMemory{m: map[string]*fileInMemory{}}
+	result.Mkdir(separator)
+	return result
+}
+
+const (
+	separator = string(filepath.Separator)
+	doubleSep = separator + separator
+)
+
+// Create assures a fake file appears in the in-memory file system.
+func (fs *fsInMemory) Create(name string) (File, error) {
+	f := &fileInMemory{}
+	f.open = true
+	fs.m[name] = f
+	return fs.m[name], nil
+}
+
+// Mkdir assures a fake directory appears in the in-memory file system.
+func (fs *fsInMemory) Mkdir(name string) error {
+	fs.m[name] = makeDir(name)
+	return nil
+}
+
+// MkdirAll delegates to Mkdir
+func (fs *fsInMemory) MkdirAll(name string) error {
+	return fs.Mkdir(name)
+}
+
+// RemoveAll presumably does rm -r on a path.
+// There's no error.
+func (fs *fsInMemory) RemoveAll(name string) error {
+	var toRemove []string
+	for k := range fs.m {
+		if strings.HasPrefix(k, name) {
+			toRemove = append(toRemove, k)
+		}
+	}
+	for _, k := range toRemove {
+		delete(fs.m, k)
+	}
+	return nil
+}
+
+// Open returns a fake file in the open state.
+func (fs *fsInMemory) Open(name string) (File, error) {
+	if _, found := fs.m[name]; !found {
+		return nil, fmt.Errorf("file %q cannot be opened", name)
+	}
+	return fs.m[name], nil
+}
+
+// CleanedAbs cannot fail.
+func (fs *fsInMemory) CleanedAbs(path string) (ConfirmedDir, string, error) {
+	if fs.IsDir(path) {
+		return ConfirmedDir(path), "", nil
+	}
+	d := filepath.Dir(path)
+	if d == path {
+		return ConfirmedDir(d), "", nil
+	}
+	return ConfirmedDir(d), filepath.Base(path), nil
+}
+
+// Exists returns true if file is known.
+func (fs *fsInMemory) Exists(name string) bool {
+	_, found := fs.m[name]
+	return found
+}
+
+// Glob returns the list of matching files
+func (fs *fsInMemory) Glob(pattern string) ([]string, error) {
+	var result []string
+	for p := range fs.m {
+		if fs.pathMatch(p, pattern) {
+			result = append(result, p)
+		}
+	}
+	sort.Strings(result)
+	return result, nil
+}
+
+// IsDir returns true if the file exists and is a directory.
+func (fs *fsInMemory) IsDir(name string) bool {
+	f, found := fs.m[name]
+	if found && f.dir {
+		return true
+	}
+	if !strings.HasSuffix(name, separator) {
+		name = name + separator
+	}
+	for k := range fs.m {
+		if strings.HasPrefix(k, name) {
+			return true
+		}
+	}
+	return false
+}
+
+// ReadFile always returns an empty bytes and error depending on content of m.
+func (fs *fsInMemory) ReadFile(name string) ([]byte, error) {
+	if ff, found := fs.m[name]; found {
+		return ff.content, nil
+	}
+	return nil, fmt.Errorf("cannot read file %q", name)
+}
+
+// WriteFile always succeeds and does nothing.
+func (fs *fsInMemory) WriteFile(name string, c []byte) error {
+	ff := &fileInMemory{}
+	ff.Write(c)
+	fs.m[name] = ff
+	return nil
+}
+
+// Walk implements filepath.Walk using the fake filesystem.
+func (fs *fsInMemory) Walk(path string, walkFn filepath.WalkFunc) error {
+	info, err := fs.lstat(path)
+	if err != nil {
+		err = walkFn(path, info, err)
+	} else {
+		err = fs.walk(path, info, walkFn)
+	}
+	if err == filepath.SkipDir {
+		return nil
+	}
+	return err
+}
+
+func (fs *fsInMemory) pathMatch(path, pattern string) bool {
+	match, _ := filepath.Match(pattern, path)
+	return match
+}
+
+func (fs *fsInMemory) lstat(path string) (*fileInfo, error) {
+	f, found := fs.m[path]
+	if !found {
+		return nil, os.ErrNotExist
+	}
+	return &fileInfo{f}, nil
+}
+
+func (fs *fsInMemory) join(elem ...string) string {
+	for i, e := range elem {
+		if e != "" {
+			return strings.Replace(
+				strings.Join(elem[i:], separator), doubleSep, separator, -1)
+		}
+	}
+	return ""
+}
+
+func (fs *fsInMemory) readDirNames(path string) []string {
+	var names []string
+	if !strings.HasSuffix(path, separator) {
+		path += separator
+	}
+	pathSegments := strings.Count(path, separator)
+	for name := range fs.m {
+		if name == path {
+			continue
+		}
+		if strings.Count(name, separator) > pathSegments {
+			continue
+		}
+		if strings.HasPrefix(name, path) {
+			names = append(names, filepath.Base(name))
+		}
+	}
+	sort.Strings(names)
+	return names
+}
+
+func (fs *fsInMemory) walk(path string, info os.FileInfo, walkFn filepath.WalkFunc) error {
+	if !info.IsDir() {
+		return walkFn(path, info, nil)
+	}
+
+	names := fs.readDirNames(path)
+	if err := walkFn(path, info, nil); err != nil {
+		return err
+	}
+	for _, name := range names {
+		filename := fs.join(path, name)
+		fileInfo, err := fs.lstat(filename)
+		if err != nil {
+			if err := walkFn(filename, fileInfo, os.ErrNotExist); err != nil && err != filepath.SkipDir {
+				return err
+			}
+		} else {
+			err = fs.walk(filename, fileInfo, walkFn)
+			if err != nil {
+				if !fileInfo.IsDir() || err != filepath.SkipDir {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}