lib/io: separate FileState for updated mode and content

Previously, when content of file being watched is modified, it will
trigger the callback with State set to FileStateModified.  When the
mode of file is modified, it will also trigger the callback with
the same state.

This changes separated those state into two kind: FileStateUpdateMode
for update on file mode, and FileStateUpdateContent for update on
file content.

5 files changed, 24 insertions, 31 deletions

diff --git a/lib/io/dirwatcher.go b/lib/io/dirwatcher.go
index 0b2e15be..b2fd10ae 100644
--- a/lib/io/dirwatcher.go
+++ b/lib/io/dirwatcher.go
@@ -297,7 +297,7 @@ func (dw *DirWatcher) onModified(node *memfs.Node, newDirInfo os.FileInfo) {
 
 	ns := &NodeState{
 		Node:  node,
-		State: FileStateModified,
+		State: FileStateUpdateMode,
 	}
 
 	dw.Callback(ns)
diff --git a/lib/io/dirwatcher_test.go b/lib/io/dirwatcher_test.go
index b5546683..449453b2 100644
--- a/lib/io/dirwatcher_test.go
+++ b/lib/io/dirwatcher_test.go
@@ -39,7 +39,7 @@ func TestDirWatcher(t *testing.T) {
 		state: FileStateCreated,
 		path:  "/",
 	}, {
-		state: FileStateModified,
+		state: FileStateUpdateMode,
 		path:  "/",
 	}, {
 		state: FileStateCreated,
diff --git a/lib/io/filestate.go b/lib/io/filestate.go
index fecb5b93..3c9cdac4 100644
--- a/lib/io/filestate.go
+++ b/lib/io/filestate.go
@@ -5,14 +5,13 @@
 package io
 
 // FileState define the state of file.
-// There are three state of file: created, modified, or deleted.
+// There are four states of file: created, updated on mode, updated on content
+// or deleted.
 type FileState byte
 
 const (
-	// FileStateCreated indicate that the file has been created.
-	FileStateCreated FileState = iota
-	// FileStateModified indicate that the file has been modified.
-	FileStateModified
-	// FileStateDeleted indicate that the file has been deleted.
-	FileStateDeleted
+	FileStateCreated       FileState = iota // New file is created.
+	FileStateUpdateContent                  // The content of file is modified.
+	FileStateUpdateMode                     // The mode of file is modified.
+	FileStateDeleted                        // The file has been deleted.
 )
diff --git a/lib/io/watcher.go b/lib/io/watcher.go
index 88f16546..daa202fe 100644
--- a/lib/io/watcher.go
+++ b/lib/io/watcher.go
@@ -93,58 +93,52 @@ func NewWatcher(path string, d time.Duration, cb WatchCallback) (w *Watcher, err
 }
 
 func (w *Watcher) start() {
+	logp := "Watcher"
 	if debug.Value >= 2 {
-		fmt.Printf("lib/io: Watcher watching %q\n", w.path)
+		fmt.Printf("%s: %s: watching for changes\n", logp, w.path)
 	}
 	for range w.ticker.C {
+		ns := &NodeState{
+			Node: w.node,
+		}
+
 		newInfo, err := os.Stat(w.path)
 		if err != nil {
 			if !os.IsNotExist(err) {
-				log.Println("lib/io: Watcher: " + err.Error())
+				log.Printf("%s: %s", logp, err.Error())
 				continue
 			}
 
 			if debug.Value >= 2 {
-				fmt.Printf("lib/io: Watcher: deleted %q\n", w.node.SysPath)
+				fmt.Printf("%s: %s: deleted\n", logp, w.node.SysPath)
 			}
 
-			ns := &NodeState{
-				Node:  w.node,
-				State: FileStateDeleted,
-			}
+			ns.State = FileStateDeleted
 			w.cb(ns)
 			w.node = nil
 			return
 		}
+
 		if w.node.Mode() != newInfo.Mode() {
 			if debug.Value >= 2 {
-				fmt.Printf("lib/io: Watcher: mode modified %q\n", w.node.SysPath)
+				fmt.Printf("%s: %s: mode modified\n", logp, w.node.SysPath)
 			}
-
+			ns.State = FileStateUpdateMode
 			w.node.SetMode(newInfo.Mode())
-			ns := &NodeState{
-				Node:  w.node,
-				State: FileStateModified,
-			}
 			w.cb(ns)
 			continue
 		}
 		if w.node.ModTime().Equal(newInfo.ModTime()) {
 			continue
 		}
-
 		if debug.Value >= 2 {
-			fmt.Printf("lib/io: Watcher: content modified %q\n", w.node.SysPath)
+			fmt.Printf("%s: %s: content modified\n", logp, w.node.SysPath)
 		}
 
 		w.node.SetModTime(newInfo.ModTime())
 		w.node.SetSize(newInfo.Size())
 
-		ns := &NodeState{
-			Node:  w.node,
-			State: FileStateModified,
-		}
-
+		ns.State = FileStateUpdateContent
 		w.cb(ns)
 	}
 }
diff --git a/lib/io/watcher_test.go b/lib/io/watcher_test.go
index b5c2166b..e158c5a8 100644
--- a/lib/io/watcher_test.go
+++ b/lib/io/watcher_test.go
@@ -28,10 +28,10 @@ func TestWatcher(t *testing.T) {
 		mode  os.FileMode
 		size  int64
 	}{{
-		state: FileStateModified,
+		state: FileStateUpdateMode,
 		mode:  0700,
 	}, {
-		state: FileStateModified,
+		state: FileStateUpdateContent,
 		mode:  0700,
 		size:  13,
 	}, {