Function mdbx_cache_get 

pub unsafe extern "C" fn mdbx_cache_get(
    txn: *const MDBX_txn,
    dbi: MDBX_dbi,
    key: *const MDBX_val,
    data: *mut MDBX_val,
    entry: *mut MDBX_cache_entry_t,
) -> MDBX_cache_result_t