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superset2/superset/migrations/shared/utils.py

96 lines
3.3 KiB
Python

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
import logging
import os
import time
from typing import Any
from uuid import uuid4
from alembic import op
from sqlalchemy import engine_from_config
from sqlalchemy.dialects.mysql.base import MySQLDialect
from sqlalchemy.dialects.postgresql.base import PGDialect
from sqlalchemy.engine import reflection
from sqlalchemy.exc import NoSuchTableError
from sqlalchemy.orm import Session
logger = logging.getLogger(__name__)
DEFAULT_BATCH_SIZE = int(os.environ.get("BATCH_SIZE", 1000))
def table_has_column(table: str, column: str) -> bool:
"""
Checks if a column exists in a given table.
:param table: A table name
:param column: A column name
:returns: True iff the column exists in the table
"""
config = op.get_context().config
engine = engine_from_config(
config.get_section(config.config_ini_section), prefix="sqlalchemy."
)
insp = reflection.Inspector.from_engine(engine)
try:
return any(col["name"] == column for col in insp.get_columns(table))
except NoSuchTableError:
return False
uuid_by_dialect = {
MySQLDialect: "UNHEX(REPLACE(CONVERT(UUID() using utf8mb4), '-', ''))",
PGDialect: "uuid_in(md5(random()::text || clock_timestamp()::text)::cstring)",
}
def assign_uuids(
model: Any, session: Session, batch_size: int = DEFAULT_BATCH_SIZE
) -> None:
"""Generate new UUIDs for all rows in a table"""
bind = op.get_bind()
table_name = model.__tablename__
count = session.query(model).count()
# silently skip if the table is empty (suitable for db initialization)
if count == 0:
return
start_time = time.time()
print(f"\nAdding uuids for `{table_name}`...")
# Use dialect specific native SQL queries if possible
for dialect, sql in uuid_by_dialect.items():
if isinstance(bind.dialect, dialect):
op.execute(
f"UPDATE {dialect().identifier_preparer.quote(table_name)} SET uuid = {sql}"
)
print(f"Done. Assigned {count} uuids in {time.time() - start_time:.3f}s.\n")
return
# Othwewise Use Python uuid function
start = 0
while start < count:
end = min(start + batch_size, count)
for obj in session.query(model)[start:end]:
obj.uuid = uuid4()
session.merge(obj)
session.commit()
if start + batch_size < count:
print(f" uuid assigned to {end} out of {count}\r", end="")
start += batch_size
print(f"Done. Assigned {count} uuids in {time.time() - start_time:.3f}s.\n")