return dirty pages tracking

memory.go

@@ -378,10 +378,19 @@ func (f *FakeFile) pwrite(b []byte, off int64) (n int, err error) {
 	}
 	n = copy(f.data.buff[off:], b)
 
-	//f.data.dyrtyPages = append(f.data.dyrtyPages, interval{from: off, to: off + int64(n)})
+	f.appendDirtyPage(off, off+int64(n))
 	return n, nil
 }
 
+func (f *FakeFile) appendDirtyPage(from int64, to int64) {
+	if !f.data.fs.trackDirtyPages {
+		return
+	}
+
+	// TODO: want to add some optimization to less allocation (e.g. for situation then we write sequentially)
+	f.data.dyrtyPages = append(f.data.dyrtyPages, interval{from: from, to: to})
+}
+
 func (f *FakeFile) WriteString(s string) (n int, err error) {
 	b := unsafe.Slice(unsafe.StringData(s), len(s))
 	return f.Write(b)

memory_fs.go

@@ -14,8 +14,9 @@ import (
 )
 
 type FakeFS struct {
-	inodes  map[string]*mockData
-	workDir string
+	inodes          map[string]*mockData
+	workDir         string
+	trackDirtyPages bool
 }
 
 var _ FS = &FakeFS{}
@@ -36,6 +37,10 @@ func NewMemoryFs() *FakeFS {
 	return fs
 }
 
+func (f *FakeFS) TrackDirtyPages() {
+	f.trackDirtyPages = true
+}
+
 func (f *FakeFS) Create(path string) (*File, error) {
 	return f.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
 }
@@ -219,7 +224,7 @@ func (f *FakeFS) ReadDir(name string) ([]os.DirEntry, error) {
 	defer fp.Close()
 
 	dirs, err := fp.ReadDir(-1)
-	slices.SortFunc(dirs, func (a os.DirEntry, b os.DirEntry) int { return cmp.Compare(a.Name(), b.Name())})
+	slices.SortFunc(dirs, func(a os.DirEntry, b os.DirEntry) int { return cmp.Compare(a.Name(), b.Name()) })
 	return dirs, err
 }