From 30c3c32863c4b870f55170d0437ef82a9d75f3fe Mon Sep 17 00:00:00 2001
From: Bohdan Lisovskyi <www.lbohdan@gmail.com>
Date: Wed, 22 Jan 2020 16:25:31 +0200
Subject: [PATCH] add chown method

---
 afero.go         |  3 +++
 basepath.go      |  7 +++++++
 cacheOnReadFs.go | 21 +++++++++++++++++++++
 copyOnWriteFs.go | 13 +++++++++++++
 mem/file.go      | 14 ++++++++++++++
 memmap.go        | 15 +++++++++++++++
 os.go            |  4 ++++
 readonlyfs.go    |  4 ++++
 regexpfs.go      |  7 +++++++
 sftpfs/sftp.go   |  4 ++++
 10 files changed, 92 insertions(+)

diff --git a/afero.go b/afero.go
index f5b5e12..5702d89 100644
--- a/afero.go
+++ b/afero.go
@@ -96,6 +96,9 @@ type Fs interface {
 
 	//Chtimes changes the access and modification times of the named file
 	Chtimes(name string, atime time.Time, mtime time.Time) error
+
+	// Chown changes uid and gid of the named file.
+	Chown(name string, uid, gid int) error
 }
 
 var (
diff --git a/basepath.go b/basepath.go
index 616ff8f..404188e 100644
--- a/basepath.go
+++ b/basepath.go
@@ -177,4 +177,11 @@ func (b *BasePathFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
 	return fi, false, err
 }
 
+
+func (b *BasePathFs) Chown(name string, uid, gid int) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "chown", Path: name, Err: err}
+	}
+	return b.source.Chown(name, uid, gid)
+}
 // vim: ts=4 sw=4 noexpandtab nolist syn=go
diff --git a/cacheOnReadFs.go b/cacheOnReadFs.go
index 29a26c6..d0db6c5 100644
--- a/cacheOnReadFs.go
+++ b/cacheOnReadFs.go
@@ -288,3 +288,24 @@ func (u *CacheOnReadFs) Create(name string) (File, error) {
 	}
 	return &UnionFile{Base: bfh, Layer: lfh}, nil
 }
+
+func (u *CacheOnReadFs) Chown(name string, uid, gid int) error {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit:
+		err = u.base.Chown(name, uid, gid)
+	case cacheStale, cacheMiss:
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+		err = u.base.Chown(name, uid, gid)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.Chown(name, uid, gid)
+}
diff --git a/copyOnWriteFs.go b/copyOnWriteFs.go
index e8108a8..3b76268 100644
--- a/copyOnWriteFs.go
+++ b/copyOnWriteFs.go
@@ -291,3 +291,16 @@ func (u *CopyOnWriteFs) MkdirAll(name string, perm os.FileMode) error {
 func (u *CopyOnWriteFs) Create(name string) (File, error) {
 	return u.OpenFile(name, os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0666)
 }
+
+func (u *CopyOnWriteFs) Chown(name string, uid, gid int) error {
+	b, err := u.isBaseFile(name)
+	if err != nil {
+		return err
+	}
+	if b {
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+	}
+	return u.layer.Chown(name, uid, gid)
+}
diff --git a/mem/file.go b/mem/file.go
index 7af2fb5..c0acbd7 100644
--- a/mem/file.go
+++ b/mem/file.go
@@ -57,6 +57,8 @@ type FileData struct {
 	dir     bool
 	mode    os.FileMode
 	modtime time.Time
+	uid     int
+	gid     int
 }
 
 func (d *FileData) Name() string {
@@ -95,6 +97,18 @@ func setModTime(f *FileData, mtime time.Time) {
 	f.modtime = mtime
 }
 
+func SetUID(f *FileData, uid int) {
+	f.Lock()
+	f.uid = uid
+	f.Unlock()
+}
+
+func SetGID(f *FileData, gid int) {
+	f.Lock()
+	f.uid = gid
+	f.Unlock()
+}
+
 func GetFileInfo(f *FileData) *FileInfo {
 	return &FileInfo{f}
 }
diff --git a/memmap.go b/memmap.go
index 09498e7..7f57436 100644
--- a/memmap.go
+++ b/memmap.go
@@ -358,6 +358,21 @@ func (m *MemMapFs) List() {
 	}
 }
 
+func (m *MemMapFs) Chown(name string, uid, gid int) error {
+	name = normalizePath(name)
+
+	m.mu.RLock()
+	f, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if !ok {
+		return &os.PathError{Op: "chown", Path: name, Err: ErrFileNotFound}
+	}
+
+	mem.SetUID(f, uid)
+	mem.SetGID(f, gid)
+
+	return nil
+}
 // func debugMemMapList(fs Fs) {
 // 	if x, ok := fs.(*MemMapFs); ok {
 // 		x.List()
diff --git a/os.go b/os.go
index 13cc1b8..916ad38 100644
--- a/os.go
+++ b/os.go
@@ -99,3 +99,7 @@ func (OsFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
 	fi, err := os.Lstat(name)
 	return fi, true, err
 }
+
+func (OsFs) Chown(name string, uid, gid int) error {
+	return os.Chown(name, uid, gid)
+}
diff --git a/readonlyfs.go b/readonlyfs.go
index c6376ec..7783386 100644
--- a/readonlyfs.go
+++ b/readonlyfs.go
@@ -78,3 +78,7 @@ func (r *ReadOnlyFs) MkdirAll(n string, p os.FileMode) error {
 func (r *ReadOnlyFs) Create(n string) (File, error) {
 	return nil, syscall.EPERM
 }
+
+func (r *ReadOnlyFs) Chown(n string, uid, gid int) error {
+	return syscall.EPERM
+}
diff --git a/regexpfs.go b/regexpfs.go
index 9d92dbc..44e50c5 100644
--- a/regexpfs.go
+++ b/regexpfs.go
@@ -212,3 +212,10 @@ func (f *RegexpFile) Truncate(s int64) error {
 func (f *RegexpFile) WriteString(s string) (int, error) {
 	return f.f.WriteString(s)
 }
+
+func (r *RegexpFs) Chown(name string, uid, gid int) error {
+	if err := r.dirOrMatches(name); err != nil {
+		return err
+	}
+	return r.source.Chown(name, uid, gid)
+}
diff --git a/sftpfs/sftp.go b/sftpfs/sftp.go
index 28721da..6ad0287 100644
--- a/sftpfs/sftp.go
+++ b/sftpfs/sftp.go
@@ -127,3 +127,7 @@ func (s Fs) Chmod(name string, mode os.FileMode) error {
 func (s Fs) Chtimes(name string, atime time.Time, mtime time.Time) error {
 	return s.client.Chtimes(name, atime, mtime)
 }
+
+func (s Fs) Chown(name string, uid, gid int) error {
+	return s.client.Chown(name, uid, gid)
+}