<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _raw_object_cache_getbuffer(self, data):
 """ Low-level getbuffer hook. """

        if self._object_cache_getbuffer is None:
            return
        module_ptr = data.contents.module_ptr
        module = self._find_module_ptr(module_ptr)
        if module is None:
            # The LLVM EE should only give notifications for modules
            # known by us.
            raise RuntimeError("object compilation notification "
                               "for unknown module %s" % (module_ptr,))

        buf = self._object_cache_getbuffer(module)
        if buf is not None:
            # Create a copy, which will be freed by the caller
            data[0].buf_ptr = ffi.lib.LLVMPY_CreateByteString(buf, len(buf))
            data[0].buf_len = len(buf)