def _ReadModifyWriteRowRequestPB(*args, **kw):
from google.cloud.bigtable._generated import (bigtable_pb2 as
messages_v2_pb2)
return messages_v2_pb2.ReadModifyWriteRowRequest(*args, **kw)
def commit(self):
"""Makes a ``ReadModifyWriteRow`` API request.
This commits modifications made by :meth:`append_cell_value` and
:meth:`increment_cell_value`. If no modifications were made, makes
no API request and just returns ``{}``.
Modifies a row atomically, reading the latest existing
timestamp / value from the specified columns and writing a new value by
appending / incrementing. The new cell created uses either the current
server time or the highest timestamp of a cell in that column (if it
exceeds the server time).
After committing the accumulated mutations, resets the local mutations.
.. code:: python
>>> append_row.commit()
{
u'col-fam-id': {
b'col-name1': [
(b'cell-val', datetime.datetime(...)),
(b'cell-val-newer', datetime.datetime(...)),
],
b'col-name2': [
(b'altcol-cell-val', datetime.datetime(...)),
],
},
u'col-fam-id2': {
b'col-name3-but-other-fam': [
(b'foo', datetime.datetime(...)),
],
},
}
:rtype: dict
:returns: The new contents of all modified cells. Returned as a
dictionary of column families, each of which holds a
dictionary of columns. Each column contains a list of cells
modified. Each cell is represented with a two-tuple with the
value (in bytes) and the timestamp for the cell.
:raises: :class:`ValueError <exceptions.ValueError>` if the number of
mutations exceeds the :data:`MAX_MUTATIONS`.
"""
num_mutations = len(self._rule_pb_list)
if num_mutations == 0:
return {}
if num_mutations > MAX_MUTATIONS:
raise ValueError('%d total append mutations exceed the maximum '
'allowable %d.' % (num_mutations, MAX_MUTATIONS))
request_pb = messages_v2_pb2.ReadModifyWriteRowRequest(
table_name=self._table.name,
row_key=self._row_key,
rules=self._rule_pb_list,
)
# We expect a `.data_v2_pb2.Row`
client = self._table._instance._client
row_response = client._data_stub.ReadModifyWriteRow(request_pb)
# Reset modifications after commit-ing request.
self.clear()
# NOTE: We expect row_response.key == self._row_key but don't check.
return _parse_rmw_row_response(row_response)
