pyignite/cluster.py

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"""
This module contains `Cluster` that lets you get info and change state of the
whole cluster.
"""
from pyignite.api.cluster import cluster_get_state, cluster_set_state
from pyignite.exceptions import ClusterError
from pyignite.utils import status_to_exception
from pyignite.datatypes import ClusterState


class Cluster:
    """
    Ignite cluster abstraction. Users should never use this class directly,
    but construct its instances with
    :py:meth:`~pyignite.client.Client.get_cluster` method instead.
    """

    def __init__(self, client: 'Client'):
        """
        :param client: :py:class:`~pyignite.client.Client` instance.
        """
        self._client = client

    @status_to_exception(ClusterError)
    def get_state(self) -> 'ClusterState':
        """
        Gets current cluster state.

        :return: Current cluster state. This is one of
         :py:attr:`~pyignite.datatypes.cluster_state.ClusterState.INACTIVE`,
         :py:attr:`~pyignite.datatypes.cluster_state.ClusterState.ACTIVE`,
         :py:attr:`~pyignite.datatypes.cluster_state.ClusterState.ACTIVE_READ_ONLY`.
        """
        return cluster_get_state(self._client.random_node)

    @status_to_exception(ClusterError)
    def set_state(self, state: 'ClusterState'):
        """
        Changes current cluster state to the given.

        Note: Deactivation clears in-memory caches (without persistence)
         including the system caches.

        :param state: New cluster state. This is one of
         :py:attr:`~pyignite.datatypes.cluster_state.ClusterState.INACTIVE`,
         :py:attr:`~pyignite.datatypes.cluster_state.ClusterState.ACTIVE`,
         :py:attr:`~pyignite.datatypes.cluster_state.ClusterState.ACTIVE_READ_ONLY`.
        """
        return cluster_set_state(self._client.random_node, state)