fix: capi protobuf cstring convension

kclvm/api/src/capi_test.rs

@@ -221,6 +221,15 @@ fn test_c_api_list_options() {
     );
 }
 
+#[test]
+fn test_c_api_parse_file() {
+    test_c_api_without_wrapper::<ParseFileArgs, ParseFileResult>(
+        "KclvmService.ParseFile",
+        "parse-file.json",
+        "parse-file.response.json",
+    );
+}
+
 #[test]
 fn test_c_api_testing() {
     test_c_api::<TestArgs, TestResult, _>(
@@ -259,10 +268,18 @@ where
         CString::from_vec_unchecked(serde_json::from_str::<A>(&input).unwrap().encode_to_vec())
     };
     let call = CString::new(svc_name).unwrap();
-    let result_ptr = kclvm_service_call(serv, call.as_ptr(), args.as_ptr());
-    let result = unsafe { CStr::from_ptr(result_ptr) };
+    let mut result_len: usize = 0;
+    let src_ptr =
+        kclvm_service_call_with_length(serv, call.as_ptr(), args.as_ptr(), &mut result_len);
+
+    let mut dest_data: Vec<u8> = Vec::with_capacity(result_len);
+    unsafe {
+        let dest_ptr: *mut u8 = dest_data.as_mut_ptr();
+        std::ptr::copy_nonoverlapping(src_ptr as *const u8, dest_ptr, result_len);
+        dest_data.set_len(result_len);
+    }
 
-    let mut result = R::decode(result.to_bytes()).unwrap();
+    let mut result = R::decode(dest_data.as_slice()).unwrap();
     let result_json = serde_json::to_string(&result).unwrap();
 
     let except_result_path = Path::new(TEST_DATA_PATH).join(output);
@@ -278,7 +295,7 @@ where
     assert_eq!(result, except_result, "\nresult json is {result_json}");
     unsafe {
         kclvm_service_delete(serv);
-        kclvm_service_free_string(result_ptr as *mut c_char);
+        kclvm_service_free_string(src_ptr as *mut c_char);
     }
 }