diff --git a/structs/bitmap/bitmap.go b/structs/bitmap/bitmap.go
index 640bc04..9d64a7f 100644
--- a/structs/bitmap/bitmap.go
+++ b/structs/bitmap/bitmap.go
@@ -45,6 +45,23 @@ func New(maxIndex uint64, opts ...Option) *Bitmap {
 	return bm
 }
 
+func (b *Bitmap) CopyTo(dst *Bitmap) {
+	if !b.lockoff {
+		b.mux.Lock()
+		defer b.mux.Unlock()
+	}
+	if !dst.lockoff {
+		dst.mux.Lock()
+		defer dst.mux.Unlock()
+	}
+
+	dst.data = make([]byte, len(b.data))
+	copy(dst.data, b.data)
+	dst.size = b.size
+	dst.max = b.max
+	dst.lockoff = b.lockoff
+}
+
 func (b *Bitmap) Set(index uint64) {
 	if index > b.max {
 		return
diff --git a/structs/bitmap/bitmap_test.go b/structs/bitmap/bitmap_test.go
index b369cf0..d856dce 100644
--- a/structs/bitmap/bitmap_test.go
+++ b/structs/bitmap/bitmap_test.go
@@ -12,6 +12,21 @@ import (
 	"go.osspkg.com/casecheck"
 )
 
+func TestUnit_Bitmap_CopyTO(t *testing.T) {
+	src := New(65)
+	src.Set(1)
+	src.Set(5)
+	src.Set(60)
+
+	dst := New(100)
+	src.CopyTo(dst)
+
+	casecheck.Equal(t, src.size, dst.size)
+	casecheck.Equal(t, src.data, dst.data)
+	casecheck.Equal(t, src.lockoff, dst.lockoff)
+	casecheck.Equal(t, src.max, dst.max)
+}
+
 func TestUnit_Bitmap_calcBlockIndex(t *testing.T) {
 	bm := New(65)
 
diff --git a/structs/bloom/bloom.go b/structs/bloom/bloom.go
index 9764f2d..69037f1 100644
--- a/structs/bloom/bloom.go
+++ b/structs/bloom/bloom.go
@@ -99,7 +99,27 @@ func New(opts ...Option) (*Bloom, error) {
 	return b, nil
 }
 
+func (b *Bloom) CopyTo(dst *Bloom) {
+	b.mux.Lock()
+	defer b.mux.Unlock()
+
+	dst.mux.Lock()
+	defer dst.mux.Unlock()
+
+	b.bits.CopyTo(dst.bits)
+	dst.size = b.size
+
+	dst.salts = make([][saltSize]byte, len(b.salts))
+	copy(dst.salts, b.salts)
+
+	dst.optSize = b.optSize
+	dst.optRate = b.optRate
+}
+
 func (b *Bloom) Dump(w io.Writer) error {
+	b.mux.RLock()
+	defer b.mux.RUnlock()
+
 	if _, err := w.Write([]byte("OSSPkg:bloom\n")); err != nil {
 		return fmt.Errorf("write header: %w", err)
 	}
@@ -118,9 +138,6 @@ func (b *Bloom) Dump(w io.Writer) error {
 		}
 	}
 
-	b.mux.RLock()
-	defer b.mux.RUnlock()
-
 	if _, err := w.Write(b.bits.Dump()); err != nil {
 		return fmt.Errorf("write bitmap: %w", err)
 	}
@@ -129,6 +146,9 @@ func (b *Bloom) Dump(w io.Writer) error {
 }
 
 func (b *Bloom) Restore(r io.Reader) error {
+	b.mux.Lock()
+	defer b.mux.Unlock()
+
 	reader := bufio.NewReader(r)
 
 	head, err := reader.ReadBytes('\n')
@@ -174,9 +194,6 @@ func (b *Bloom) Restore(r io.Reader) error {
 		return fmt.Errorf("read bitmap: %w", err)
 	}
 
-	b.mux.Lock()
-	defer b.mux.Unlock()
-
 	b.bits.Restore(bm)
 
 	return nil
diff --git a/structs/bloom/bloom_test.go b/structs/bloom/bloom_test.go
index dc208b0..07d9e67 100644
--- a/structs/bloom/bloom_test.go
+++ b/structs/bloom/bloom_test.go
@@ -10,6 +10,7 @@ import (
 	"crypto/md5"
 	"crypto/sha1"
 	"crypto/sha256"
+	"fmt"
 	"hash"
 	"hash/fnv"
 	"reflect"
@@ -20,7 +21,7 @@ import (
 )
 
 func TestUnit_Bloom(t *testing.T) {
-	bf, err := New(Quantity(1000, 0.00001))
+	bf, err := New(Quantity(4, 0.01))
 	casecheck.NoError(t, err)
 
 	bf.Add("hello")
@@ -34,8 +35,16 @@ func TestUnit_Bloom(t *testing.T) {
 
 	buf := bytes.NewBuffer(nil)
 	casecheck.NoError(t, bf.Dump(buf))
-	//fmt.Println(string(buf.Bytes()))
+	b1 := buf.Bytes()
+
+	fmt.Println(string(b1))
+
 	casecheck.NoError(t, bf.Restore(buf))
+	buf = bytes.NewBuffer(nil)
+	casecheck.NoError(t, bf.Dump(buf))
+	b2 := buf.Bytes()
+
+	casecheck.Equal(t, b1, b2)
 
 	casecheck.False(t, bf.Contain("users"))
 	casecheck.True(t, bf.Contain("user"))