def read_row(self, row_key, filter_=None):
"""Read a single row from this table.
:type row_key: bytes
:param row_key: The key of the row to read from.
:type filter_: :class:`.RowFilter`
:param filter_: (Optional) The filter to apply to the contents of the
row. If unset, returns the entire row.
:rtype: :class:`.PartialRowData`, :data:`NoneType <types.NoneType>`
:returns: The contents of the row if any chunks were returned in
the response, otherwise :data:`None`.
:raises: :class:`ValueError <exceptions.ValueError>` if a commit row
chunk is never encountered.
"""
request_pb = _create_row_request(self.name,
row_key=row_key,
filter_=filter_)
client = self._cluster._client
response_iterator = client._data_stub.ReadRows(request_pb,
client.timeout_seconds)
# We expect an iterator of `data_messages_pb2.ReadRowsResponse`
result = PartialRowData(row_key)
for read_rows_response in response_iterator:
result.update_from_read_rows(read_rows_response)
# Make sure the result actually contains data.
if not result._chunks_encountered:
return None
# Make sure the result was committed by the back-end.
if not result.committed:
raise ValueError('The row remains partial / is not committed.')
return result
def test_read_rows(self):
row = self._table.row(ROW_KEY)
row_alt = self._table.row(ROW_KEY_ALT)
self.rows_to_delete.extend([row, row_alt])
cell1, cell2, cell3, cell4 = self._write_to_row(row, row_alt,
row, row_alt)
row.commit()
row_alt.commit()
rows_data = self._table.read_rows()
self.assertEqual(rows_data.rows, {})
rows_data.consume_all()
# NOTE: We should refrain from editing protected data on instances.
# Instead we should make the values public or provide factories
# for constructing objects with them.
row_data = PartialRowData(ROW_KEY)
row_data._chunks_encountered = True
row_data._committed = True
row_data._cells = {
COLUMN_FAMILY_ID1: {
COL_NAME1: [cell1],
COL_NAME2: [cell3],
},
}
row_alt_data = PartialRowData(ROW_KEY_ALT)
row_alt_data._chunks_encountered = True
row_alt_data._committed = True
row_alt_data._cells = {
COLUMN_FAMILY_ID1: {
COL_NAME1: [cell2],
},
COLUMN_FAMILY_ID2: {
COL_NAME3: [cell4],
},
}
expected_rows = {
ROW_KEY: row_data,
ROW_KEY_ALT: row_alt_data,
}
self.assertEqual(rows_data.rows, expected_rows)
def _read_row_helper(self, chunks):
from gcloud._testing import _Monkey
from gcloud.bigtable._generated import (
bigtable_service_messages_pb2 as messages_pb2)
from gcloud.bigtable._testing import _FakeStub
from gcloud.bigtable.row_data import PartialRowData
from gcloud.bigtable import table as MUT
project_id = 'project-id'
zone = 'zone'
cluster_id = 'cluster-id'
table_id = 'table-id'
timeout_seconds = 596
client = _Client(timeout_seconds=timeout_seconds)
cluster_name = ('projects/' + project_id + '/zones/' + zone +
'/clusters/' + cluster_id)
cluster = _Cluster(cluster_name, client=client)
table = self._makeOne(table_id, cluster)
# Create request_pb
request_pb = object() # Returned by our mock.
mock_created = []
def mock_create_row_request(table_name, row_key, filter_):
mock_created.append((table_name, row_key, filter_))
return request_pb
# Create response_iterator
row_key = b'row-key'
response_pb = messages_pb2.ReadRowsResponse(row_key=row_key,
chunks=chunks)
response_iterator = [response_pb]
# Patch the stub used by the API method.
client._data_stub = stub = _FakeStub(response_iterator)
# Create expected_result.
if chunks:
expected_result = PartialRowData(row_key)
expected_result._committed = True
expected_result._chunks_encountered = True
else:
expected_result = None
# Perform the method and check the result.
filter_obj = object()
with _Monkey(MUT, _create_row_request=mock_create_row_request):
result = table.read_row(row_key, filter_=filter_obj)
self.assertEqual(result, expected_result)
self.assertEqual(stub.method_calls, [(
'ReadRows',
(request_pb, timeout_seconds),
{},
)])
self.assertEqual(mock_created, [(table.name, row_key, filter_obj)])
def test_consume_next(self):
from gcloud.bigtable._generated import (
bigtable_service_messages_pb2 as messages_pb2)
from gcloud.bigtable.row_data import PartialRowData
row_key = b'row-key'
value_pb = messages_pb2.ReadRowsResponse(row_key=row_key)
response_iterator = _MockCancellableIterator(value_pb)
partial_rows_data = self._makeOne(response_iterator)
self.assertEqual(partial_rows_data.rows, {})
partial_rows_data.consume_next()
expected_rows = {row_key: PartialRowData(row_key)}
self.assertEqual(partial_rows_data.rows, expected_rows)
def test_consume_next_row_exists(self):
from gcloud.bigtable._generated import (
bigtable_service_messages_pb2 as messages_pb2)
from gcloud.bigtable.row_data import PartialRowData
row_key = b'row-key'
chunk = messages_pb2.ReadRowsResponse.Chunk(commit_row=True)
value_pb = messages_pb2.ReadRowsResponse(row_key=row_key,
chunks=[chunk])
response_iterator = _MockCancellableIterator(value_pb)
partial_rows_data = self._makeOne(response_iterator)
existing_values = PartialRowData(row_key)
partial_rows_data._rows[row_key] = existing_values
self.assertFalse(existing_values.committed)
partial_rows_data.consume_next()
self.assertTrue(existing_values.committed)
self.assertEqual(existing_values.cells, {})
def test_read_row_complete(self):
from gcloud.bigtable.row_data import Cell
from gcloud.bigtable.row_data import PartialRowData
chunk = _ReadRowsResponseCellChunkPB(
row_key=self.ROW_KEY,
family_name=self.FAMILY_NAME,
qualifier=self.QUALIFIER,
timestamp_micros=self.TIMESTAMP_MICROS,
value=self.VALUE,
commit_row=True,
)
chunks = [chunk]
expected_result = PartialRowData(row_key=self.ROW_KEY)
family = expected_result._cells.setdefault(self.FAMILY_NAME, {})
column = family.setdefault(self.QUALIFIER, [])
column.append(Cell.from_pb(chunk))
self._read_row_helper(chunks, expected_result)
