def commit(self):
"""Makes a ``CheckAndMutateRow`` API request.
If no mutations have been created in the row, no request is made.
The mutations will be applied conditionally, based on whether the
filter matches any cells in the :class:`ConditionalRow` or not. (Each
method which adds a mutation has a ``state`` parameter for this
purpose.)
Mutations are applied atomically and in order, meaning that earlier
mutations can be masked / negated by later ones. Cells already present
in the row are left unchanged unless explicitly changed by a mutation.
After committing the accumulated mutations, resets the local
mutations.
:rtype: bool
:returns: Flag indicating if the filter was matched (which also
indicates which set of mutations were applied by the server).
:raises: :class:`ValueError <exceptions.ValueError>` if the number of
mutations exceeds the :data:`MAX_MUTATIONS`.
"""
true_mutations = self._get_mutations(state=True)
false_mutations = self._get_mutations(state=False)
num_true_mutations = len(true_mutations)
num_false_mutations = len(false_mutations)
if num_true_mutations == 0 and num_false_mutations == 0:
return
if (num_true_mutations > MAX_MUTATIONS
or num_false_mutations > MAX_MUTATIONS):
raise ValueError(
'Exceed the maximum allowable mutations (%d). Had %s true '
'mutations and %d false mutations.' %
(MAX_MUTATIONS, num_true_mutations, num_false_mutations))
request_pb = messages_v2_pb2.CheckAndMutateRowRequest(
table_name=self._table.name,
row_key=self._row_key,
predicate_filter=self._filter.to_pb(),
true_mutations=true_mutations,
false_mutations=false_mutations,
)
# We expect a `.messages_v2_pb2.CheckAndMutateRowResponse`
client = self._table._instance._client
resp = client._data_stub.CheckAndMutateRow(request_pb)
self.clear()
return resp.predicate_matched
def _CheckAndMutateRowRequestPB(*args, **kw):
from google.cloud.bigtable._generated import (bigtable_pb2 as
messages_v2_pb2)
return messages_v2_pb2.CheckAndMutateRowRequest(*args, **kw)
