def _get_node_by_hashcode()

in pyignite/client.py [0:0]

• 22 lines of code
• 12 McCabe index (conditional complexity)

    def _get_node_by_hashcode(self, cache_id, hashcode, parts):
        """
        Get node by key hashcode. Calculate partition and return node on that it is primary.
        (algorithm is taken from `RendezvousAffinityFunction.java`)
        """

        # calculate partition for key or affinity key
        # (algorithm is taken from `RendezvousAffinityFunction.java`)
        mask = parts - 1

        if parts & mask == 0:
            part = (hashcode ^ (unsigned(hashcode) >> 16)) & mask
        else:
            part = abs(hashcode // parts)

        assert 0 <= part < parts, 'Partition calculation has failed'

        node_mapping = self._cache_partition_mapping(cache_id).get('node_mapping')
        if not node_mapping:
            return None

        node_uuid, best_conn = None, None
        for u, p in node_mapping.items():
            if part in p:
                node_uuid = u
                break

        if node_uuid:
            for n in self._nodes:
                if n.uuid == node_uuid:
                    best_conn = n
                    break
            if best_conn and best_conn.alive:
                return best_conn