mapreduce.operations.ndb - helper for Google App Engine MapReduce NDB operations

ndb.py

"""NDB-related operations."""


__all__ = ['Put', 'Delete']


from mapreduce.operation import base

# pylint: disable=protected-access


class Put(base.Operation):
  """Put entity into datastore via mutation_pool.

  See mapreduce.context._MutationPool.
  """

  def __init__(self, entity):
    """Constructor.

    Args:
      entity: an entity to put.
    """
    self.entity = entity

  def __call__(self, context):
    """Perform operation.

    Args:
      context: mapreduce context as context.Context.
    """
    context._mutation_pool.ndb_put(self.entity)


class Delete(base.Operation):
  """Delete entity from datastore via mutation_pool.

  See mapreduce.context._MutationPool.
  """

  def __init__(self, entity):
    """Constructor.

    Args:
      entity: a key or model instance to delete.
    """
    self.entity = entity

  def __call__(self, context):
    """Perform operation.

    Args:
      context: mapreduce context as context.Context.
    """
    context._mutation_pool.ndb_delete(self.entity)