def create_vtgate_cursor(class_, vtgate_conn, tablet_type, is_dml, **cursor_kargs):
cursor_method = functools.partial(db_object.create_cursor_from_params,
vtgate_conn, tablet_type, False)
routing = class_.create_shard_routing(cursor_method, **cursor_kargs)
if is_dml:
if routing.sharding_key is None or db_object._is_iterable_container(routing.sharding_key):
dbexceptions.InternalError(
"Writes require unique sharding_key")
keyspace_ids = None
keyranges = None
if routing.sharding_key is not None:
keyspace_ids = []
if db_object._is_iterable_container(routing.sharding_key):
for sk in routing.sharding_key:
kid = class_.sharding_key_to_keyspace_id(sk)
keyspace_ids.append(pack_keyspace_id(kid))
else:
kid = class_.sharding_key_to_keyspace_id(routing.sharding_key)
keyspace_ids = [pack_keyspace_id(kid),]
elif routing.entity_id_sharding_key_map is not None:
keyspace_ids = []
for sharding_key in routing.entity_id_sharding_key_map.values():
keyspace_ids.append(pack_keyspace_id(class_.sharding_key_to_keyspace_id(sharding_key)))
elif routing.keyrange:
keyranges = [routing.keyrange,]
cursor = vtgate_cursor.VTGateCursor(vtgate_conn,
class_.keyspace,
tablet_type,
keyspace_ids=keyspace_ids,
keyranges=keyranges,
writable=is_dml)
cursor.routing = routing
return cursor
def create_vtgate_cursor(class_, vtgate_conn, tablet_type, is_dml,
**cursor_kargs):
cursor_method = functools.partial(db_object.create_cursor_from_params,
vtgate_conn, tablet_type, False)
routing = class_.create_shard_routing(cursor_method, **cursor_kargs)
if is_dml:
if routing.sharding_key is None or db_object._is_iterable_container(
routing.sharding_key):
dbexceptions.InternalError(
"Writes require unique sharding_key")
keyspace_ids = None
keyranges = None
if routing.sharding_key is not None:
keyspace_ids = []
if db_object._is_iterable_container(routing.sharding_key):
for sk in routing.sharding_key:
kid = class_.sharding_key_to_keyspace_id(sk)
keyspace_ids.append(pack_keyspace_id(kid))
else:
kid = class_.sharding_key_to_keyspace_id(routing.sharding_key)
keyspace_ids = [
pack_keyspace_id(kid),
]
elif routing.entity_id_sharding_key_map is not None:
keyspace_ids = []
for sharding_key in routing.entity_id_sharding_key_map.values():
keyspace_ids.append(
pack_keyspace_id(
class_.sharding_key_to_keyspace_id(sharding_key)))
elif routing.keyrange:
keyranges = [
routing.keyrange,
]
cursor = vtgate_cursor.VTGateCursor(vtgate_conn,
class_.keyspace,
tablet_type,
keyspace_ids=keyspace_ids,
keyranges=keyranges,
writable=is_dml)
cursor.routing = routing
return cursor
def select_by_ids(class_,
cursor,
where_column_value_pairs,
columns_list=None,
order_by=None,
group_by=None,
limit=None,
**kwargs):
"""This method is used to perform in-clause queries.
Such queries can cause vtgate to scatter over multiple shards.
This uses execute_entity_ids method of vtgate cursor and the entity
column and the associated entity_keyspace_id_map is computed based
on the routing used - sharding_key or entity_id_map.
"""
if columns_list is None:
columns_list = class_.columns_list
query, bind_vars = class_.create_select_query(
where_column_value_pairs,
columns_list=columns_list,
order_by=order_by,
group_by=group_by,
limit=limit,
**kwargs)
entity_col_name = None
entity_id_keyspace_id_map = {}
if cursor.routing.sharding_key is not None:
# If the in-clause is based on sharding key
entity_col_name = class_.sharding_key_column_name
if db_object._is_iterable_container(cursor.routing.sharding_key):
for sk in list(cursor.routing.sharding_key):
entity_id_keyspace_id_map[sk] = pack_keyspace_id(
class_.sharding_key_to_keyspace_id(sk))
else:
sk = cursor.routing.sharding_key
entity_id_keyspace_id_map[sk] = pack_keyspace_id(
class_.sharding_key_to_keyspace_id(sk))
elif cursor.routing.entity_id_sharding_key_map is not None:
# If the in-clause is based on entity column
entity_col_name = cursor.routing.entity_column_name
for en_id, sk in cursor.routing.entity_id_sharding_key_map.iteritems(
):
entity_id_keyspace_id_map[en_id] = pack_keyspace_id(
class_.sharding_key_to_keyspace_id(sk))
else:
dbexceptions.ProgrammingError("Invalid routing method used.")
# cursor.routing.entity_column_name is set while creating shard routing.
rowcount = cursor.execute_entity_ids(query, bind_vars,
entity_id_keyspace_id_map,
entity_col_name)
rows = cursor.fetchall()
return [sql_builder.DBRow(columns_list, row) for row in rows]
def select_by_ids(class_, cursor, where_column_value_pairs,
columns_list = None,order_by=None, group_by=None,
limit=None, **kwargs):
"""This method is used to perform in-clause queries.
Such queries can cause vtgate to scatter over multiple shards.
This uses execute_entity_ids method of vtgate cursor and the entity
column and the associated entity_keyspace_id_map is computed based
on the routing used - sharding_key or entity_id_map.
"""
if class_.columns_list is None:
raise dbexceptions.ProgrammingError("DB class should define columns_list")
if columns_list is None:
columns_list = class_.columns_list
query, bind_vars = sql_builder.select_by_columns_query(columns_list,
class_.table_name,
where_column_value_pairs,
order_by=order_by,
group_by=group_by,
limit=limit,
**kwargs)
entity_col_name = None
entity_id_keyspace_id_map = {}
if cursor.routing.sharding_key is not None:
# If the in-clause is based on sharding key
entity_col_name = class_.sharding_key_column_name
if db_object._is_iterable_container(cursor.routing.sharding_key):
for sk in list(cursor.routing.sharding_key):
entity_id_keyspace_id_map[sk] = pack_keyspace_id(class_.sharding_key_to_keyspace_id(sk))
else:
sk = cursor.routing.sharding_key
entity_id_keyspace_id_map[sk] = pack_keyspace_id(class_.sharding_key_to_keyspace_id(sk))
elif cursor.routing.entity_id_sharding_key_map is not None:
# If the in-clause is based on entity column
entity_col_name = cursor.routing.entity_column_name
for en_id, sk in cursor.routing.entity_id_sharding_key_map.iteritems():
entity_id_keyspace_id_map[en_id] = pack_keyspace_id(class_.sharding_key_to_keyspace_id(sk))
else:
dbexceptions.ProgrammingError("Invalid routing method used.")
# cursor.routing.entity_column_name is set while creating shard routing.
rowcount = cursor.execute_entity_ids(query, bind_vars,
entity_id_keyspace_id_map,
entity_col_name)
rows = cursor.fetchall()
return [sql_builder.DBRow(columns_list, row) for row in rows]
