decoder.py 文件源码

def valueDecoder(self, substrate, asn1Spec,
                     tagSet=None, length=None, state=None,
                     decodeFun=None, substrateFun=None,
                     **options):
        if asn1Spec is None or asn1Spec is not None and tagSet != asn1Spec.tagSet:
            fullSubstrate = options['fullSubstrate']

            # untagged Any container, recover inner header substrate
            length += len(fullSubstrate) - len(substrate)
            substrate = fullSubstrate

        if substrateFun:
            return substrateFun(self._createComponent(asn1Spec, tagSet),
                                substrate, length)

        head, tail = substrate[:length], substrate[length:]

        return self._createComponent(asn1Spec, tagSet, value=head), tail