feat: refactor doc write in native (#14272)

packages/common/native/src/doc_parser/doc_loader.rs

@@ -0,0 +1,39 @@
+use y_octo::{Doc, DocOptions};
+
+use super::ParseError;
+
+pub(super) fn is_empty_doc(binary: &[u8]) -> bool {
+  binary.is_empty() || binary == [0, 0]
+}
+
+pub(super) fn load_doc(binary: &[u8], doc_id: Option<&str>) -> Result<Doc, ParseError> {
+  if is_empty_doc(binary) {
+    return Err(ParseError::InvalidBinary);
+  }
+
+  let mut doc = build_doc(doc_id);
+  doc
+    .apply_update_from_binary_v1(binary)
+    .map_err(|_| ParseError::InvalidBinary)?;
+  Ok(doc)
+}
+
+pub(super) fn load_doc_or_new(binary: &[u8]) -> Result<Doc, ParseError> {
+  if is_empty_doc(binary) {
+    return Ok(DocOptions::new().build());
+  }
+
+  let mut doc = DocOptions::new().build();
+  doc
+    .apply_update_from_binary_v1(binary)
+    .map_err(|_| ParseError::InvalidBinary)?;
+  Ok(doc)
+}
+
+fn build_doc(doc_id: Option<&str>) -> Doc {
+  let options = DocOptions::new();
+  match doc_id {
+    Some(doc_id) => options.with_guid(doc_id.to_string()).build(),
+    None => options.build(),
+  }
+}