lib9p

commit 5944c1fe580363b2e373e7ab4fbe420c59e48a02
parent 54b8547e46c57f6a208bf3efd5a40e9cca9df833
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Sat, 16 Dec 2023 09:11:14 +0900

cache gid
assuming that gids are not changed by other program

Diffstat:
M
diskfs/stat_unix.go
 | 
35
++++++++++++++++++++++++++---------

1 file changed, 26 insertions(+), 9 deletions(-)
diff --git a/diskfs/stat_unix.go b/diskfs/stat_unix.go
@@ -52,6 +52,12 @@ func fiStat(pool *QidPool, id fileID, info fs.FileInfo) *lib9p.Stat {
 	}
 }
 
+var gidCache map[fileID]string
+
+func init() {
+	gidCache = make(map[fileID]string)
+}
+
 // Stat is real implementation of File.Stat.
 func (f *File) stat() (*lib9p.FileInfo, error) {
 	ospath := filepath.Join(f.fs.rootPath, f.path)
@@ -69,26 +75,30 @@ func (f *File) stat() (*lib9p.FileInfo, error) {
 			panic(fmt.Errorf("alloc qid: %v", err))
 		}
 	}
+	stat_t := fsfi.Sys().(*syscall.Stat_t)
 	stat.Qid = qid
 	stat.Length = fsfi.Size()
 	stat.Mode = fsfi.Mode()
 	stat.Name = fsfi.Name()
-	// TODO: Unix specific.
-	stat.Atime = uint32(fsfi.Sys().(*syscall.Stat_t).Atim.Sec)
-	stat.Mtime = uint32(fsfi.Sys().(*syscall.Stat_t).Mtim.Sec)
-	uid := fsfi.Sys().(*syscall.Stat_t).Uid
+	stat.Atime = uint32(stat_t.Atim.Sec)
+	stat.Mtime = uint32(stat_t.Mtim.Sec)
+	uid := stat_t.Uid
 	usr, err := user.LookupId(strconv.Itoa(int(uid)))
 	if err != nil {
 		return nil, fmt.Errorf("LookupId(%d): %v", uid, err)
 	}
 	stat.Uid = usr.Username
-	gid := fsfi.Sys().(*syscall.Stat_t).Gid
+	gid := stat_t.Gid
 	// TODO: this call is time consuming.
-	group, err := user.LookupGroupId(strconv.Itoa(int(gid)))
-	if err != nil {
-		return nil, fmt.Errorf("LookupGroupId(%d): %v", gid, err)
+	fileid := fileID{device: stat_t.Dev, inode: stat_t.Ino}
+	if _, ok := gidCache[fileid]; !ok {
+		group, err := user.LookupGroupId(strconv.Itoa(int(gid)))
+		if err != nil {
+			return nil, fmt.Errorf("LookupGroupId(%d): %v", gid, err)
+		}
+		gidCache[fileid] = group.Name
 	}
-	stat.Gid = group.Name
+	stat.Gid = gidCache[fileid]
 	stat.Muid = ""
 	return &lib9p.FileInfo{stat}, nil
 }
@@ -163,6 +173,13 @@ func (f *File) wstat(s *lib9p.Stat) error {
 		if err := file.Chown(u, g); err != nil {
 			return fmt.Errorf("chown: %v", err)
 		}
+		st, err := file.Stat()
+		if err != nil {
+			return fmt.Errorf("stat: %v", err)
+		}
+		stat_t := st.Sys().(*syscall.Stat_t)
+		fileid := fileID{device: stat_t.Dev, inode: stat_t.Ino}
+		gidCache[fileid] = s.Gid
 	}
 	if s.Name != oldStat.Name {
 		// TODO: check neither Names contains "/"