diff --git a/android/library-encrypt/src/main/jniLibs/arm64-v8a/libmmkv.so b/android/library-encrypt/src/main/jniLibs/arm64-v8a/libmmkv.so
index 858ccbb..9906dd3 100755
Binary files a/android/library-encrypt/src/main/jniLibs/arm64-v8a/libmmkv.so and b/android/library-encrypt/src/main/jniLibs/arm64-v8a/libmmkv.so differ
diff --git a/android/library-encrypt/src/main/jniLibs/armeabi-v7a/libmmkv.so b/android/library-encrypt/src/main/jniLibs/armeabi-v7a/libmmkv.so
index 8a8e75b..ebbc9b3 100755
Binary files a/android/library-encrypt/src/main/jniLibs/armeabi-v7a/libmmkv.so and b/android/library-encrypt/src/main/jniLibs/armeabi-v7a/libmmkv.so differ
diff --git a/android/library-encrypt/src/main/jniLibs/x86_64/libmmkv.so b/android/library-encrypt/src/main/jniLibs/x86_64/libmmkv.so
index 37cb842..1df5b2e 100755
Binary files a/android/library-encrypt/src/main/jniLibs/x86_64/libmmkv.so and b/android/library-encrypt/src/main/jniLibs/x86_64/libmmkv.so differ
diff --git a/android/library/src/main/jniLibs/arm64-v8a/libmmkv.so b/android/library/src/main/jniLibs/arm64-v8a/libmmkv.so
index fe6ed9b..2ac8648 100755
Binary files a/android/library/src/main/jniLibs/arm64-v8a/libmmkv.so and b/android/library/src/main/jniLibs/arm64-v8a/libmmkv.so differ
diff --git a/android/library/src/main/jniLibs/armeabi-v7a/libmmkv.so b/android/library/src/main/jniLibs/armeabi-v7a/libmmkv.so
index 6b4343f..d26ca14 100755
Binary files a/android/library/src/main/jniLibs/armeabi-v7a/libmmkv.so and b/android/library/src/main/jniLibs/armeabi-v7a/libmmkv.so differ
diff --git a/android/library/src/main/jniLibs/x86_64/libmmkv.so b/android/library/src/main/jniLibs/x86_64/libmmkv.so
index c6d400e..faa9992 100755
Binary files a/android/library/src/main/jniLibs/x86_64/libmmkv.so and b/android/library/src/main/jniLibs/x86_64/libmmkv.so differ
diff --git a/ios/MMKV/RustMMKV.xcframework.zip b/ios/MMKV/RustMMKV.xcframework.zip
index a4421ed..cc1356b 100644
Binary files a/ios/MMKV/RustMMKV.xcframework.zip and b/ios/MMKV/RustMMKV.xcframework.zip differ
diff --git a/src/core/iter.rs b/src/core/iter.rs
index 2e71736..328fe98 100644
--- a/src/core/iter.rs
+++ b/src/core/iter.rs
@@ -19,7 +19,7 @@ impl MemoryMap {
         F: Fn(&[u8]) -> crate::Result<DecodeResult>,
     {
         let start = LEN_OFFSET;
-        let end = self.len();
+        let end = self.content_len();
         Iter {
             mm: self,
             start,
diff --git a/src/core/memory_map.rs b/src/core/memory_map.rs
index 5c7c231..dc99270 100644
--- a/src/core/memory_map.rs
+++ b/src/core/memory_map.rs
@@ -75,7 +75,6 @@ impl DerefMut for RawMmap {
 }
 
 unsafe impl Send for RawMmap {}
-unsafe impl Sync for RawMmap {}
 
 #[derive(Debug)]
 pub struct MemoryMap(RawMmap);
@@ -88,7 +87,7 @@ impl MemoryMap {
 
     pub fn append(&mut self, value: Vec<u8>) -> io::Result<()> {
         let data_len = value.len();
-        let start = self.len();
+        let start = self.content_len();
         let content_len = start - LEN_OFFSET;
         let end = data_len + start;
         let new_content_len = data_len + content_len;
@@ -103,10 +102,16 @@ impl MemoryMap {
         self.0.flush(LEN_OFFSET)
     }
 
-    pub fn len(&self) -> usize {
+    /// The content len of current mmap
+    pub fn content_len(&self) -> usize {
         usize::from_be_bytes(self.0[0..LEN_OFFSET].try_into().unwrap()) + LEN_OFFSET
     }
 
+    /// The max len of current mmap
+    pub fn len(&self) -> usize {
+        self.0.len
+    }
+
     pub fn read(&self, range: Range<usize>) -> &[u8] {
         self.0[range].as_ref()
     }
@@ -130,21 +135,21 @@ mod tests {
             .unwrap();
         file.set_len(1024).unwrap();
         let mut mm = MemoryMap::new(&file, 1024);
-        assert_eq!(mm.len(), 8);
+        assert_eq!(mm.content_len(), 8);
         mm.append(vec![1, 2, 3]).unwrap();
         mm.append(vec![4]).unwrap();
-        assert_eq!(mm.len(), 12);
+        assert_eq!(mm.content_len(), 12);
 
         let read = mm.read(8..10);
         assert_eq!(read.len(), 2);
         assert_eq!(read[0], 1);
         assert_eq!(read[1], 2);
-        let read = mm.read(mm.len() - 1..mm.len());
+        let read = mm.read(mm.content_len() - 1..mm.content_len());
         assert_eq!(read[0], 4);
 
         mm.reset().unwrap();
         mm.append(vec![5, 4, 3, 2, 1]).unwrap();
-        assert_eq!(mm.len(), 13);
+        assert_eq!(mm.content_len(), 13);
         let read = mm.read(8..9);
         assert_eq!(read[0], 5);
 
diff --git a/src/core/mmkv_impl.rs b/src/core/mmkv_impl.rs
index 91d7fba..2d9361d 100644
--- a/src/core/mmkv_impl.rs
+++ b/src/core/mmkv_impl.rs
@@ -60,14 +60,14 @@ impl IOWriter {
     }
 
     // Flash the data to file, always running in one io thread, so don't need lock here
-    fn write(&mut self, buffer: Buffer, map: HashMap<String, Buffer>, duplicated: bool) {
+    fn write(&mut self, buffer: Buffer, duplicated: bool, snapshot: HashMap<String, Buffer>) {
         let data = self.encoder.encode_to_bytes(&buffer).unwrap();
-        let target_end = data.len() + self.mm.len();
-        let file_size = self.config.file_size();
+        let target_end = data.len() + self.mm.content_len();
+        let max_len = self.mm.len();
         if duplicated {
             self.need_trim = true;
         }
-        if target_end as u64 <= file_size {
+        if target_end <= max_len {
             self.mm.append(data).unwrap();
             return;
         }
@@ -76,15 +76,15 @@ impl IOWriter {
             #[cfg(feature = "encryption")]
             self.encryptor.reset();
             let time_start = Instant::now();
-            info!(LOG_TAG, "start trim, current len {}", self.mm.len());
+            info!(LOG_TAG, "start trim, current len {}", self.mm.content_len());
             let mut count = 0;
             self.mm
                 .reset()
                 .map_err(|e| EncodeFailed(e.to_string()))
                 .unwrap();
-            for buffer in map.values() {
+            for buffer in snapshot.values() {
                 let bytes = self.encoder.encode_to_bytes(buffer).unwrap();
-                if self.mm.len() + bytes.len() > file_size as usize {
+                if self.mm.content_len() + bytes.len() > max_len {
                     self.expand();
                 }
                 self.mm.append(bytes).unwrap();
@@ -95,7 +95,7 @@ impl IOWriter {
                 LOG_TAG,
                 "wrote {} items, new len {}, cost {:?}",
                 count,
-                self.mm.len(),
+                self.mm.content_len(),
                 time_start.elapsed()
             );
         } else {
@@ -145,7 +145,8 @@ impl MmkvImpl {
             #[cfg(feature = "encryption")]
             encryptor,
         );
-        let content_len = io_writer.mm.len();
+        let content_len = io_writer.mm.content_len();
+        let file_len = io_writer.mm.len();
         let mmkv = MmkvImpl {
             kv_map,
             is_valid: true,
@@ -153,9 +154,10 @@ impl MmkvImpl {
         };
         info!(
             LOG_TAG,
-            "instance initialized, read {} items, content len {}, cost {:?}",
+            "instance initialized, read {} items, content len {}, file len {}, cost {:?}",
             mmkv.kv_map.len(),
             content_len,
+            file_len,
             time_start.elapsed()
         );
         mmkv
@@ -167,12 +169,12 @@ impl MmkvImpl {
         }
         let result = self.kv_map.insert(key.to_string(), raw_buffer.clone());
         let duplicated = result.is_some();
-        let map = self.kv_map.clone();
+        let snapshot = self.kv_map.clone();
         self.io_looper.as_ref().unwrap().post(move |callback| {
             callback
                 .downcast_mut::<IOWriter>()
                 .unwrap()
-                .write(raw_buffer, map, duplicated)
+                .write(raw_buffer, duplicated, snapshot)
         })
     }
 
@@ -242,7 +244,10 @@ mod tests {
                 .as_ref()
                 .unwrap()
                 .post(|writer| {
-                    assert_eq!(writer.downcast_ref::<IOWriter>().unwrap().mm.len(), $value);
+                    assert_eq!(
+                        writer.downcast_ref::<IOWriter>().unwrap().mm.content_len(),
+                        $value
+                    );
                 })
                 .expect("");
         };
diff --git a/src/mmkv.rs b/src/mmkv.rs
index 903c399..0c01735 100644
--- a/src/mmkv.rs
+++ b/src/mmkv.rs
@@ -62,7 +62,8 @@ impl MMKV {
     Initialize the MMKV instance with a writeable directory,
     absolute or relative paths are acceptable.
 
-    All API calls before initialization will panic.
+    All API calls(except [set_logger](MMKV::set_logger), [set_log_level](MMKV::set_log_level))
+    before initialization will panic.
 
     Calling [initialize](MMKV::initialize) multiple times is allowed,
     the old instance will be closed (see [close](MMKV::close)), the last call will take over.