Method substrateFunWrapper

pager_lib/pyasn1/codec/ber/decoder.py:2099–2116

Support both 0.4 and 0.5 style APIs. substrateFun API has changed in 0.5 for use with streaming decoders. To stay backwards compatible, we first try if we received a streaming user callback. If that fails,we assume we've received a non-streaming v0.4

(asn1Object, substrate, length, options=None)

            origSubstrateFun = options["substrateFun"]

            def substrateFunWrapper(asn1Object, substrate, length, options=None):
                """Support both 0.4 and 0.5 style APIs.

                substrateFun API has changed in 0.5 for use with streaming decoders. To stay backwards compatible,
                we first try if we received a streaming user callback. If that fails,we assume we've received a
                non-streaming v0.4 user callback and convert it for streaming on the fly
                """
                try:
                    substrate_gen = origSubstrateFun(asn1Object, substrate, length, options)
                except TypeError as _value:
                    if _value.__traceback__.tb_next:
                        # Traceback depth > 1 means TypeError from inside user provided function
                        raise
                    # invariant maintained at Decoder.__call__ entry
                    assert isinstance(substrate, io.BytesIO)  # nosec assert_used
                    substrate_gen = Decoder._callSubstrateFunV4asV5(origSubstrateFun, asn1Object, substrate, length)
                for value in substrate_gen:
                    yield value

            options["substrateFun"] = substrateFunWrapper