def create_index_psql(conn: Connection) -> None:
conn.rollback()
# postgres insists on autocommit for the index
conn.set_session(autocommit=True) # type: ignore
try:
c = conn.cursor()
# If a previous attempt to create the index was interrupted,
# we may already have a half-built index. Let's just drop it
# before trying to create it again.
sql = "DROP INDEX IF EXISTS %s" % (index_name,)
logger.debug("[SQL] %s", sql)
c.execute(sql)
sql = (
"CREATE %(unique)s INDEX CONCURRENTLY %(name)s"
" ON %(table)s"
" (%(columns)s) %(where_clause)s"
) % {
"unique": "UNIQUE" if unique else "",
"name": index_name,
"table": table,
"columns": ", ".join(columns),
"where_clause": "WHERE " + where_clause if where_clause else "",
}
logger.debug("[SQL] %s", sql)
c.execute(sql)
finally:
conn.set_session(autocommit=False) # type: ignore
def prepare_database(
db_conn: Connection,
database_engine: BaseDatabaseEngine,
config: Optional[HomeServerConfig],
databases: Collection[str] = ["main", "state"],
):
"""Prepares a physical database for usage. Will either create all necessary tables
or upgrade from an older schema version.
If `config` is None then prepare_database will assert that no upgrade is
necessary, *or* will create a fresh database if the database is empty.
Args:
db_conn:
database_engine:
config :
application config, or None if we are connecting to an existing
database which we expect to be configured already
databases: The name of the databases that will be used
with this physical database. Defaults to all databases.
"""
try:
cur = db_conn.cursor()
# sqlite does not automatically start transactions for DDL / SELECT statements,
# so we start one before running anything. This ensures that any upgrades
# are either applied completely, or not at all.
#
# (psycopg2 automatically starts a transaction as soon as we run any statements
# at all, so this is redundant but harmless there.)
cur.execute("BEGIN TRANSACTION")
logger.info("%r: Checking existing schema version", databases)
version_info = _get_or_create_schema_state(cur, database_engine)
if version_info:
user_version, delta_files, upgraded = version_info
logger.info(
"%r: Existing schema is %i (+%i deltas)",
databases,
user_version,
len(delta_files),
)
# config should only be None when we are preparing an in-memory SQLite db,
# which should be empty.
if config is None:
raise ValueError(
"config==None in prepare_database, but databse is not empty"
)
# if it's a worker app, refuse to upgrade the database, to avoid multiple
# workers doing it at once.
if config.worker_app is not None and user_version != SCHEMA_VERSION:
raise UpgradeDatabaseException(
OUTDATED_SCHEMA_ON_WORKER_ERROR % (SCHEMA_VERSION, user_version)
)
_upgrade_existing_database(
cur,
user_version,
delta_files,
upgraded,
database_engine,
config,
databases=databases,
)
else:
logger.info("%r: Initialising new database", databases)
# if it's a worker app, refuse to upgrade the database, to avoid multiple
# workers doing it at once.
if config and config.worker_app is not None:
raise UpgradeDatabaseException(EMPTY_DATABASE_ON_WORKER_ERROR)
_setup_new_database(cur, database_engine, databases=databases)
# check if any of our configured dynamic modules want a database
if config is not None:
_apply_module_schemas(cur, database_engine, config)
cur.close()
db_conn.commit()
except Exception:
db_conn.rollback()
raise