def _set_session_sql_mode(dbapi_con,
connection_rec,
connection_proxy,
sql_mode=None):
"""
Set the sql_mode session variable.
"""
cursor = dbapi_con.cursor()
if sql_mode is not None:
cursor.execute("SET SESSION sql_mode = %s", [sql_mode])
# Check against the real effective SQL mode. Even when unset by
# our own config, the server may still be operating in a specific
# SQL mode as set by the server configuration
cursor.execute("SHOW VARIABLES LIKE 'sql_mode'")
row = cursor.fetchone()
if row is None:
LOG.warning(_LW('Unable to detect effective SQL mode'))
return
realmode = row[1]
LOG.info(_LI('MySQL server mode set to %s') % realmode)
# 'TRADITIONAL' mode enables several other modes, so
# we need a substring match here
if not ('TRADITIONAL' in realmode.upper()
or 'STRICT_ALL_TABLES' in realmode.upper()):
LOG.warning(
_LW("MySQL SQL mode is '%s', "
"consider enabling TRADITIONAL or STRICT_ALL_TABLES") %
realmode)
def _set_session_sql_mode(dbapi_con, connection_rec,
connection_proxy, sql_mode=None):
"""
Set the sql_mode session variable.
"""
cursor = dbapi_con.cursor()
if sql_mode is not None:
cursor.execute("SET SESSION sql_mode = %s", [sql_mode])
# Check against the real effective SQL mode. Even when unset by
# our own config, the server may still be operating in a specific
# SQL mode as set by the server configuration
cursor.execute("SHOW VARIABLES LIKE 'sql_mode'")
row = cursor.fetchone()
if row is None:
LOG.warning(_LW('Unable to detect effective SQL mode'))
return
realmode = row[1]
LOG.info(_LI('MySQL server mode set to %s') % realmode)
# 'TRADITIONAL' mode enables several other modes, so
# we need a substring match here
if not ('TRADITIONAL' in realmode.upper() or
'STRICT_ALL_TABLES' in realmode.upper()):
LOG.warning(_LW("MySQL SQL mode is '%s', "
"consider enabling TRADITIONAL or STRICT_ALL_TABLES")
% realmode)
def _ping_listener(engine, dbapi_conn, connection_rec, connection_proxy):
"""
Ensures that MySQL and DB2 connections are alive.
"""
cursor = dbapi_conn.cursor()
try:
ping_sql = 'select 1'
if engine.name == 'ibm_db_sa':
# DB2 requires a table expression
ping_sql = 'select 1 from (values (1)) AS t1'
cursor.execute(ping_sql)
except Exception as ex:
if engine.dialect.is_disconnect(ex, dbapi_conn, cursor):
msg = _LW('Database server has gone away: %s') % ex
LOG.warning(msg)
raise sqla_exc.DisconnectionError(msg)
else:
raise
def _ping_listener(engine, dbapi_conn, connection_rec, connection_proxy):
"""
Ensures that MySQL and DB2 connections are alive.
"""
cursor = dbapi_conn.cursor()
try:
ping_sql = 'select 1'
if engine.name == 'ibm_db_sa':
# DB2 requires a table expression
ping_sql = 'select 1 from (values (1)) AS t1'
cursor.execute(ping_sql)
except Exception as ex:
if engine.dialect.is_disconnect(ex, dbapi_conn, cursor):
msg = _LW('Database server has gone away: %s') % ex
LOG.warning(msg)
raise sqla_exc.DisconnectionError(msg)
else:
raise
def create_engine(sql_connection, sqlite_fk=False, mysql_sql_mode=None,
mysql_traditional_mode=False, idle_timeout=3600,
connection_debug=0, max_pool_size=None, max_overflow=None,
pool_timeout=None, sqlite_synchronous=True,
connection_trace=False, max_retries=10, retry_interval=10):
"""Return a new SQLAlchemy engine."""
connection_dict = sqlalchemy.engine.url.make_url(sql_connection)
engine_args = {
"pool_recycle": idle_timeout,
'convert_unicode': True,
}
logger = logging.getLogger('sqlalchemy.engine')
# Map SQL debug level to Python log level
if connection_debug >= 100:
logger.setLevel(logging.DEBUG)
elif connection_debug >= 50:
logger.setLevel(logging.INFO)
else:
logger.setLevel(logging.WARNING)
if "sqlite" in connection_dict.drivername:
if sqlite_fk:
engine_args["listeners"] = [SqliteForeignKeysListener()]
engine_args["poolclass"] = NullPool
if sql_connection == "sqlite://":
engine_args["poolclass"] = StaticPool
engine_args["connect_args"] = {'check_same_thread': False}
else:
if max_pool_size is not None:
engine_args['pool_size'] = max_pool_size
if max_overflow is not None:
engine_args['max_overflow'] = max_overflow
if pool_timeout is not None:
engine_args['pool_timeout'] = pool_timeout
engine = sqlalchemy.create_engine(sql_connection, **engine_args)
sqlalchemy.event.listen(engine, 'checkin', _thread_yield)
if engine.name in ['mysql', 'ibm_db_sa']:
ping_callback = functools.partial(_ping_listener, engine)
sqlalchemy.event.listen(engine, 'checkout', ping_callback)
if engine.name == 'mysql':
if mysql_traditional_mode:
mysql_sql_mode = 'TRADITIONAL'
if mysql_sql_mode:
mode_callback = functools.partial(_set_session_sql_mode,
sql_mode=mysql_sql_mode)
sqlalchemy.event.listen(engine, 'checkout', mode_callback)
elif 'sqlite' in connection_dict.drivername:
if not sqlite_synchronous:
sqlalchemy.event.listen(engine, 'connect',
_synchronous_switch_listener)
sqlalchemy.event.listen(engine, 'connect', _add_regexp_listener)
if connection_trace and engine.dialect.dbapi.__name__ == 'MySQLdb':
_patch_mysqldb_with_stacktrace_comments()
try:
engine.connect()
except sqla_exc.OperationalError as e:
if not _is_db_connection_error(e.args[0]):
raise
remaining = max_retries
if remaining == -1:
remaining = 'infinite'
while True:
msg = _LW('SQL connection failed. %s attempts left.')
LOG.warning(msg % remaining)
if remaining != 'infinite':
remaining -= 1
time.sleep(retry_interval)
try:
engine.connect()
break
except sqla_exc.OperationalError as e:
if (remaining != 'infinite' and remaining == 0) or \
not _is_db_connection_error(e.args[0]):
raise
return engine
def paginate_query(query,
model,
limit,
sort_keys,
marker=None,
sort_dir=None,
sort_dirs=None):
"""
Returns a query with sorting / pagination criteria added.
"""
if 'id' not in sort_keys:
# TODO(justinsb): If this ever gives a false-positive, check
# the actual primary key, rather than assuming its id
LOG.warning(_LW('Id not in sort_keys; is sort_keys unique?'))
assert (not (sort_dir and sort_dirs))
# Default the sort direction to ascending
if sort_dirs is None and sort_dir is None:
sort_dir = 'asc'
# Ensure a per-column sort direction
if sort_dirs is None:
sort_dirs = [sort_dir for _sort_key in sort_keys]
assert (len(sort_dirs) == len(sort_keys))
# Add sorting
for current_sort_key, current_sort_dir in zip(sort_keys, sort_dirs):
try:
sort_dir_func = {
'asc': sqlalchemy.asc,
'desc': sqlalchemy.desc,
}[current_sort_dir]
except KeyError:
raise ValueError(
_("Unknown sort direction, "
"must be 'desc' or 'asc'"))
try:
sort_key_attr = getattr(model, current_sort_key)
except AttributeError:
raise InvalidSortKey()
query = query.order_by(sort_dir_func(sort_key_attr))
# Add pagination
if marker is not None:
marker_values = []
for sort_key in sort_keys:
v = getattr(marker, sort_key)
marker_values.append(v)
# Build up an array of sort criteria as in the docstring
criteria_list = []
for i in range(len(sort_keys)):
crit_attrs = []
for j in range(i):
model_attr = getattr(model, sort_keys[j])
crit_attrs.append((model_attr == marker_values[j]))
model_attr = getattr(model, sort_keys[i])
if sort_dirs[i] == 'desc':
crit_attrs.append((model_attr < marker_values[i]))
else:
crit_attrs.append((model_attr > marker_values[i]))
criteria = sqlalchemy.sql.and_(*crit_attrs)
criteria_list.append(criteria)
f = sqlalchemy.sql.or_(*criteria_list)
query = query.filter(f)
if limit is not None:
query = query.limit(limit)
return query
def create_engine(sql_connection,
sqlite_fk=False,
mysql_sql_mode=None,
mysql_traditional_mode=False,
idle_timeout=3600,
connection_debug=0,
max_pool_size=None,
max_overflow=None,
pool_timeout=None,
sqlite_synchronous=True,
connection_trace=False,
max_retries=10,
retry_interval=10):
"""Return a new SQLAlchemy engine."""
connection_dict = sqlalchemy.engine.url.make_url(sql_connection)
engine_args = {
"pool_recycle": idle_timeout,
'convert_unicode': True,
}
logger = logging.getLogger('sqlalchemy.engine')
# Map SQL debug level to Python log level
if connection_debug >= 100:
logger.setLevel(logging.DEBUG)
elif connection_debug >= 50:
logger.setLevel(logging.INFO)
else:
logger.setLevel(logging.WARNING)
if "sqlite" in connection_dict.drivername:
if sqlite_fk:
engine_args["listeners"] = [SqliteForeignKeysListener()]
engine_args["poolclass"] = NullPool
if sql_connection == "sqlite://":
engine_args["poolclass"] = StaticPool
engine_args["connect_args"] = {'check_same_thread': False}
else:
if max_pool_size is not None:
engine_args['pool_size'] = max_pool_size
if max_overflow is not None:
engine_args['max_overflow'] = max_overflow
if pool_timeout is not None:
engine_args['pool_timeout'] = pool_timeout
engine = sqlalchemy.create_engine(sql_connection, **engine_args)
sqlalchemy.event.listen(engine, 'checkin', _thread_yield)
if engine.name in ['mysql', 'ibm_db_sa']:
ping_callback = functools.partial(_ping_listener, engine)
sqlalchemy.event.listen(engine, 'checkout', ping_callback)
if engine.name == 'mysql':
if mysql_traditional_mode:
mysql_sql_mode = 'TRADITIONAL'
if mysql_sql_mode:
mode_callback = functools.partial(_set_session_sql_mode,
sql_mode=mysql_sql_mode)
sqlalchemy.event.listen(engine, 'checkout', mode_callback)
elif 'sqlite' in connection_dict.drivername:
if not sqlite_synchronous:
sqlalchemy.event.listen(engine, 'connect',
_synchronous_switch_listener)
sqlalchemy.event.listen(engine, 'connect', _add_regexp_listener)
if connection_trace and engine.dialect.dbapi.__name__ == 'MySQLdb':
_patch_mysqldb_with_stacktrace_comments()
try:
engine.connect()
except sqla_exc.OperationalError as e:
if not _is_db_connection_error(e.args[0]):
raise
remaining = max_retries
if remaining == -1:
remaining = 'infinite'
while True:
msg = _LW('SQL connection failed. %s attempts left.')
LOG.warning(msg % remaining)
if remaining != 'infinite':
remaining -= 1
time.sleep(retry_interval)
try:
engine.connect()
break
except sqla_exc.OperationalError as e:
if (remaining != 'infinite' and remaining == 0) or \
not _is_db_connection_error(e.args[0]):
raise
return engine
def paginate_query(query, model, limit, sort_keys, marker=None,
sort_dir=None, sort_dirs=None):
"""
Returns a query with sorting / pagination criteria added.
"""
if 'id' not in sort_keys:
# TODO(justinsb): If this ever gives a false-positive, check
# the actual primary key, rather than assuming its id
LOG.warning(_LW('Id not in sort_keys; is sort_keys unique?'))
assert(not (sort_dir and sort_dirs))
# Default the sort direction to ascending
if sort_dirs is None and sort_dir is None:
sort_dir = 'asc'
# Ensure a per-column sort direction
if sort_dirs is None:
sort_dirs = [sort_dir for _sort_key in sort_keys]
assert(len(sort_dirs) == len(sort_keys))
# Add sorting
for current_sort_key, current_sort_dir in zip(sort_keys, sort_dirs):
try:
sort_dir_func = {
'asc': sqlalchemy.asc,
'desc': sqlalchemy.desc,
}[current_sort_dir]
except KeyError:
raise ValueError(_("Unknown sort direction, "
"must be 'desc' or 'asc'"))
try:
sort_key_attr = getattr(model, current_sort_key)
except AttributeError:
raise InvalidSortKey()
query = query.order_by(sort_dir_func(sort_key_attr))
# Add pagination
if marker is not None:
marker_values = []
for sort_key in sort_keys:
v = getattr(marker, sort_key)
marker_values.append(v)
# Build up an array of sort criteria as in the docstring
criteria_list = []
for i in range(len(sort_keys)):
crit_attrs = []
for j in range(i):
model_attr = getattr(model, sort_keys[j])
crit_attrs.append((model_attr == marker_values[j]))
model_attr = getattr(model, sort_keys[i])
if sort_dirs[i] == 'desc':
crit_attrs.append((model_attr < marker_values[i]))
else:
crit_attrs.append((model_attr > marker_values[i]))
criteria = sqlalchemy.sql.and_(*crit_attrs)
criteria_list.append(criteria)
f = sqlalchemy.sql.or_(*criteria_list)
query = query.filter(f)
if limit is not None:
query = query.limit(limit)
return query
