Function obj_doc_upsert 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn obj_doc_upsert(
    txn: *mut obj_write_txn_t,
    collection: *const c_char,
    id: u64,
    payload: *const u8,
    payload_len: usize,
) -> obj_error_t

Insert-or-replace the document at id in collection with payload. The collection is lazy-created if absent.

Safety

As obj_doc_insert.