Source code for airflow.models.base

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from typing import Any

from sqlalchemy import MetaData, String
from sqlalchemy.ext.declarative import declarative_base

from airflow.configuration import conf

[docs]SQL_ALCHEMY_SCHEMA = conf.get("database", "SQL_ALCHEMY_SCHEMA")

[docs]metadata = (
    None if not SQL_ALCHEMY_SCHEMA or SQL_ALCHEMY_SCHEMA.isspace() else MetaData(schema=SQL_ALCHEMY_SCHEMA)
)
[docs]Base: Any = declarative_base(metadata=metadata)

[docs]ID_LEN = 250


[docs]def get_id_collation_args():
    """Get SQLAlchemy args to use for COLLATION"""
    collation = conf.get('database', 'sql_engine_collation_for_ids', fallback=None)
    if collation:
        return {'collation': collation}
    else:
        # Automatically use utf8mb3_bin collation for mysql
        # This is backwards-compatible. All our IDS are ASCII anyway so even if
        # we migrate from previously installed database with different collation and we end up mixture of
        # COLLATIONS, it's not a problem whatsoever (and we keep it small enough so that our indexes
        # for MYSQL will not exceed the maximum index size.
        #
        # See https://github.com/apache/airflow/pull/17603#issuecomment-901121618.
        #
        # We cannot use session/dialect as at this point we are trying to determine the right connection
        # parameters, so we use the connection
        conn = conf.get('database', 'sql_alchemy_conn', fallback='')
        if conn.startswith('mysql') or conn.startswith("mariadb"):
            return {'collation': 'utf8mb3_bin'}
        return {}


[docs]COLLATION_ARGS = get_id_collation_args()


[docs]def StringID(*, length=ID_LEN, **kwargs) -> String:
    return String(length=length, **kwargs, **COLLATION_ARGS)