ovsdbapp/ovsdbapp/backend/ovs_idl/__init__.py

232 lines
8.5 KiB
Python

# Licensed 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 uuid
from ovsdbapp.backend.ovs_idl import command as cmd
from ovsdbapp.backend.ovs_idl import idlutils
from ovsdbapp.backend.ovs_idl import transaction
from ovsdbapp import exceptions
LOG = logging.getLogger(__name__)
_NO_DEFAULT = object()
class Backend(object):
lookup_table = {}
_ovsdb_connection = None
def __init__(self, connection, start=True, auto_index=True, **kwargs):
super().__init__(**kwargs)
self.ovsdb_connection = connection
if auto_index:
if connection.is_running:
LOG.debug("Connection already started, not creating indices")
else:
self.autocreate_indices()
if start:
self.start_connection(connection)
@property
def ovsdb_connection(self):
return self.__class__._ovsdb_connection
@ovsdb_connection.setter
def ovsdb_connection(self, connection):
if self.__class__._ovsdb_connection is None:
self.__class__._ovsdb_connection = connection
def create_index(self, table, *columns):
"""Create a multi-column index on a table
:param table: The table on which to create an index
:type table: string
:param columns: The columns in the index
:type columns: string
"""
index_name = idlutils.index_name(*columns)
idx = self.tables[table].rows.index_create(index_name)
idx.add_columns(*columns)
def autocreate_indices(self):
"""Create simple one-column indexes
This creates indexes for all lookup_table entries and for all defined
indexes columns in the OVSDB schema, as long as they are simple
one-column indexes (e.g. 'name') fields.
"""
tables = set(self.idl.tables.keys())
# lookup table indices
for table, (lt, col, uuid_col) in self.lookup_table.items():
if table != lt or not col or uuid_col or table not in tables:
# Just handle simple cases where we are looking up a single
# column on a single table
continue
index_name = idlutils.index_name(col)
try:
idx = self.idl.tables[table].rows.index_create(index_name)
except ValueError:
LOG.debug("lookup_table index %s.%s already exists", table,
index_name)
else:
idx.add_column(col)
LOG.debug("Created lookup_table index %s.%s", table,
index_name)
tables.remove(table)
# Simple ovsdb-schema indices
for table in self.idl.tables.values():
if table.name not in tables:
continue
col = idlutils.get_index_column(table)
if not col:
continue
index_name = idlutils.index_name(col)
try:
idx = table.rows.index_create(index_name)
except ValueError:
LOG.debug("schema index %s.%s already exists", table,
index_name)
else:
idx.add_column(col)
LOG.debug("Created schema index %s.%s", table.name, index_name)
tables.remove(table.name)
def start_connection(self, connection):
try:
self.ovsdb_connection.start()
except Exception as e:
connection_exception = exceptions.OvsdbConnectionUnavailable(
db_schema=self.schema, error=e)
LOG.exception(connection_exception)
raise connection_exception from e
def restart_connection(self):
self.ovsdb_connection.stop()
self.ovsdb_connection.start()
@property
def idl(self):
return self.ovsdb_connection.idl
@property
def tables(self):
return self.idl.tables
_tables = tables
def create_transaction(self, check_error=False, log_errors=True, **kwargs):
return transaction.Transaction(
self, self.ovsdb_connection,
self.ovsdb_connection.timeout,
check_error, log_errors)
def db_create(self, table, **col_values):
return cmd.DbCreateCommand(self, table, **col_values)
def db_create_row(self, table, **col_values):
return cmd.DbCreateCommand(self, table, _as_row=True, **col_values)
def db_destroy(self, table, record):
return cmd.DbDestroyCommand(self, table, record)
def db_set(self, table, record, *col_values):
return cmd.DbSetCommand(self, table, record, *col_values)
def db_add(self, table, record, column, *values):
return cmd.DbAddCommand(self, table, record, column, *values)
def db_clear(self, table, record, column):
return cmd.DbClearCommand(self, table, record, column)
def db_get(self, table, record, column):
return cmd.DbGetCommand(self, table, record, column)
def db_list(self, table, records=None, columns=None, if_exists=False):
return cmd.DbListCommand(self, table, records, columns, if_exists)
def db_list_rows(self, table, records=None, if_exists=False):
return cmd.DbListCommand(self, table, records, columns=None, row=True,
if_exists=if_exists)
def db_find(self, table, *conditions, **kwargs):
return cmd.DbFindCommand(self, table, *conditions, **kwargs)
def db_find_rows(self, table, *conditions, **kwargs):
return cmd.DbFindCommand(self, table, *conditions, row=True, **kwargs)
def db_remove(self, table, record, column, *values, **keyvalues):
return cmd.DbRemoveCommand(self, table, record, column,
*values, **keyvalues)
def lookup(self, table, record, default=_NO_DEFAULT):
try:
with self.ovsdb_connection.lock:
return self._lookup(table, record)
except idlutils.RowNotFound:
if default is not _NO_DEFAULT:
return default
raise
def _lookup(self, table, record):
if record == "":
raise TypeError("Cannot look up record by empty string")
# Handle commands by simply returning its result
if isinstance(record, cmd.BaseCommand):
return record.result
t = self.tables[table]
if isinstance(record, uuid.UUID):
try:
return t.rows[record]
except KeyError:
raise idlutils.RowNotFound(table=table, col='uuid',
match=record) from None
try:
uuid_ = uuid.UUID(record)
return t.rows[uuid_]
except ValueError:
# Not a UUID string, continue lookup by other means
pass
except KeyError:
# If record isn't found by UUID , go ahead and look up by the table
pass
if not self.lookup_table:
raise idlutils.RowNotFound(table=table, col='record',
match=record)
# NOTE (twilson) This is an approximation of the db-ctl implementation
# that allows a partial table, assuming that if a table has a single
# index, that we should be able to do a lookup by it.
rl = self.lookup_table.get(
table,
idlutils.RowLookup(table, idlutils.get_index_column(t), None))
# no table means uuid only, no column means lookup table has one row
if rl.table is None:
raise idlutils.RowNotFound(table=table, col='uuid', match=record)
if rl.column is None:
if t.max_rows == 1:
return next(iter(t.rows.values()))
raise idlutils.RowNotFound(table=table, col='uuid', match=record)
row = idlutils.row_by_value(self, rl.table, rl.column, record)
if rl.uuid_column:
rows = getattr(row, rl.uuid_column)
if len(rows) != 1:
raise idlutils.RowNotFound(table=table, col='record',
match=record)
row = rows[0]
return row