diff options
Diffstat (limited to 'dashboard/backend/dovetail/db/utils.py')
| -rwxr-xr-x | dashboard/backend/dovetail/db/utils.py | 478 |
1 files changed, 478 insertions, 0 deletions
diff --git a/dashboard/backend/dovetail/db/utils.py b/dashboard/backend/dovetail/db/utils.py new file mode 100755 index 00000000..5e788a71 --- /dev/null +++ b/dashboard/backend/dovetail/db/utils.py @@ -0,0 +1,478 @@ +############################################################################## +# Copyright (c) 2016 Huawei Technologies Co.,Ltd and others. +# +# All rights reserved. This program and the accompanying materials +# are made available under the terms of the Apache License, Version 2.0 +# which accompanies this distribution, and is available at +# http://www.apache.org/licenses/LICENSE-2.0 +############################################################################## + +"""Utilities for database.""" + + +import functools +import inspect +import logging + +from sqlalchemy import and_ +from sqlalchemy import or_ + +from dovetail.db import exception +from dovetail.db import models + + +def add_db_object(session, table, exception_when_existing=True, + *args, **kwargs): + """Create db object. + + If not exception_when_existing and the db object exists, + Instead of raising exception, updating the existing db object. + """ + if not session: + raise exception.DatabaseException('session param is None') + with session.begin(subtransactions=True): + logging.debug( + 'session %s add object %s atributes %s to table %s', + id(session), args, kwargs, table.__name__) + argspec = inspect.getargspec(table.__init__) + arg_names = argspec.args[1:] + arg_defaults = argspec.defaults + if not arg_defaults: + arg_defaults = [] + if not ( + len(arg_names) - len(arg_defaults) <= len(args) <= len(arg_names) + ): + raise exception.InvalidParameter( + 'arg names %s does not match arg values %s' % ( + arg_names, args) + ) + db_keys = dict(zip(arg_names, args)) + logging.debug('db_keys:%s' % db_keys) + if db_keys: + db_object = session.query(table).filter_by(**db_keys).first() + else: + logging.debug('db object is None') + db_object = None + + new_object = False + if db_object: + logging.debug( + 'got db object %s: %s', db_keys, db_object + ) + if exception_when_existing: + raise exception.DuplicatedRecord( + '%s exists in table %s' % (db_keys, table.__name__) + ) + else: + db_object = table(**db_keys) + new_object = True + + for key, value in kwargs.items(): + setattr(db_object, key, value) + + logging.debug('db_object:%s' % db_object) + if new_object: + session.add(db_object) + session.flush() + db_object.initialize() + db_object.validate() + logging.debug( + 'session %s db object %s added', id(session), db_object + ) + return db_object + + +def list_db_objects(session, table, order_by=[], **filters): + """List db objects. + + If order by given, the db objects should be sorted by the ordered keys. + """ + if not session: + raise exception.DatabaseException('session param is None') + with session.begin(subtransactions=True): + logging.debug( + 'session %s list db objects by filters %s in table %s', + id(session), filters, table.__name__ + ) + db_objects = model_order_by( + model_filter( + model_query(session, table), + table, + **filters + ), + table, + order_by + ).all() + logging.debug( + 'session %s got listed db objects: %s', + id(session), db_objects + ) + return db_objects + + +def get_db_object(session, table, exception_when_missing=True, **kwargs): + """Get db object. + + If not exception_when_missing and the db object can not be found, + return None instead of raising exception. + """ + if not session: + raise exception.DatabaseException('session param is None') + with session.begin(subtransactions=True): + logging.debug( + 'session %s get db object %s from table %s', + id(session), kwargs, table.__name__) + db_object = model_filter( + model_query(session, table), table, **kwargs + ).first() + logging.debug( + 'session %s got db object %s', id(session), db_object + ) + if db_object: + return db_object + + if not exception_when_missing: + return None + + raise exception.RecordNotExists( + 'Cannot find the record in table %s: %s' % ( + table.__name__, kwargs + ) + ) + + +def del_db_objects(session, table, **filters): + """delete db objects.""" + if not session: + raise exception.DatabaseException('session param is None') + with session.begin(subtransactions=True): + logging.debug( + 'session %s delete db objects by filters %s in table %s', + id(session), filters, table.__name__ + ) + query = model_filter( + model_query(session, table), table, **filters + ) + db_objects = query.all() + query.delete(synchronize_session=False) + logging.debug( + 'session %s db objects %s deleted', id(session), db_objects + ) + return db_objects + + +def model_order_by(query, model, order_by): + """append order by into sql query model.""" + if not order_by: + return query + order_by_cols = [] + for key in order_by: + if isinstance(key, tuple): + key, is_desc = key + else: + is_desc = False + if isinstance(key, basestring): + if hasattr(model, key): + col_attr = getattr(model, key) + else: + continue + else: + col_attr = key + if is_desc: + order_by_cols.append(col_attr.desc()) + else: + order_by_cols.append(col_attr) + return query.order_by(*order_by_cols) + + +def _model_condition(col_attr, value): + """Generate condition for one column. + + Example for col_attr is name: + value is 'a': name == 'a' + value is ['a']: name == 'a' + value is ['a', 'b']: name == 'a' or name == 'b' + value is {'eq': 'a'}: name == 'a' + value is {'lt': 'a'}: name < 'a' + value is {'le': 'a'}: name <= 'a' + value is {'gt': 'a'}: name > 'a' + value is {'ge': 'a'}: name >= 'a' + value is {'ne': 'a'}: name != 'a' + value is {'in': ['a', 'b']}: name in ['a', 'b'] + value is {'notin': ['a', 'b']}: name not in ['a', 'b'] + value is {'startswith': 'abc'}: name like 'abc%' + value is {'endswith': 'abc'}: name like '%abc' + value is {'like': 'abc'}: name like '%abc%' + value is {'between': ('a', 'c')}: name >= 'a' and name <= 'c' + value is [{'lt': 'a'}]: name < 'a' + value is [{'lt': 'a'}, {'gt': c'}]: name < 'a' or name > 'c' + value is {'lt': 'c', 'gt': 'a'}: name > 'a' and name < 'c' + + If value is a list, the condition is the or relationship among + conditions of each item. + If value is dict and there are multi keys in the dict, the relationship + is and conditions of each key. + Otherwise the condition is to compare the column with the value. + """ + if isinstance(value, list): + basetype_values = [] + composite_values = [] + for item in value: + if isinstance(item, (list, dict)): + composite_values.append(item) + else: + basetype_values.append(item) + conditions = [] + if basetype_values: + if len(basetype_values) == 1: + condition = (col_attr == basetype_values[0]) + else: + condition = col_attr.in_(basetype_values) + conditions.append(condition) + for composite_value in composite_values: + condition = _model_condition(col_attr, composite_value) + if condition is not None: + conditions.append(condition) + if not conditions: + return None + if len(conditions) == 1: + return conditions[0] + return or_(*conditions) + elif isinstance(value, dict): + conditions = [] + if 'eq' in value: + conditions.append(_model_condition_func( + col_attr, value['eq'], + lambda attr, data: attr == data, + lambda attr, data, item_condition_func: attr.in_(data) + )) + if 'lt' in value: + conditions.append(_model_condition_func( + col_attr, value['lt'], + lambda attr, data: attr < data, + _one_item_list_condition_func + )) + if 'gt' in value: + conditions.append(_model_condition_func( + col_attr, value['gt'], + lambda attr, data: attr > data, + _one_item_list_condition_func + )) + if 'le' in value: + conditions.append(_model_condition_func( + col_attr, value['le'], + lambda attr, data: attr <= data, + _one_item_list_condition_func + )) + if 'ge' in value: + conditions.append(_model_condition_func( + col_attr, value['ge'], + lambda attr, data: attr >= data, + _one_item_list_condition_func + )) + if 'ne' in value: + conditions.append(_model_condition_func( + col_attr, value['ne'], + lambda attr, data: attr != data, + lambda attr, data, item_condition_func: attr.notin_(data) + )) + if 'in' in value: + conditions.append(col_attr.in_(value['in'])) + if 'notin' in value: + conditions.append(col_attr.notin_(value['notin'])) + if 'startswith' in value: + conditions.append(_model_condition_func( + col_attr, value['startswith'], + lambda attr, data: attr.like('%s%%' % data) + )) + if 'endswith' in value: + conditions.append(_model_condition_func( + col_attr, value['endswith'], + lambda attr, data: attr.like('%%%s' % data) + )) + if 'like' in value: + conditions.append(_model_condition_func( + col_attr, value['like'], + lambda attr, data: attr.like('%%%s%%' % data) + )) + conditions = [ + condition + for condition in conditions + if condition is not None + ] + if not conditions: + return None + if len(conditions) == 1: + return conditions[0] + return and_(conditions) + else: + condition = (col_attr == value) + return condition + + +def _default_list_condition_func(col_attr, value, condition_func): + """The default condition func for a list of data. + + Given the condition func for single item of data, this function + wrap the condition_func and return another condition func using + or_ to merge the conditions of each single item to deal with a + list of data item. + + Args: + col_attr: the colomn name + value: the column value need to be compared. + condition_func: the sqlalchemy condition object like == + + Examples: + col_attr is name, value is ['a', 'b', 'c'] and + condition_func is ==, the returned condition is + name == 'a' or name == 'b' or name == 'c' + """ + conditions = [] + for sub_value in value: + condition = condition_func(col_attr, sub_value) + if condition is not None: + conditions.append(condition) + if conditions: + return or_(*conditions) + else: + return None + + +def _one_item_list_condition_func(col_attr, value, condition_func): + """The wrapper condition func to deal with one item data list. + + For simplification, it is used to reduce generating too complex + sql conditions. + """ + if value: + return condition_func(col_attr, value[0]) + else: + return None + + +def _model_condition_func( + col_attr, value, + item_condition_func, + list_condition_func=_default_list_condition_func +): + """Return sql condition based on value type.""" + if isinstance(value, list): + if not value: + return None + if len(value) == 1: + return item_condition_func(col_attr, value) + return list_condition_func( + col_attr, value, item_condition_func + ) + else: + return item_condition_func(col_attr, value) + + +def model_filter(query, model, **filters): + """Append conditons to query for each possible column.""" + for key, value in filters.items(): + if isinstance(key, basestring): + if hasattr(model, key): + col_attr = getattr(model, key) + else: + continue + else: + col_attr = key + + condition = _model_condition(col_attr, value) + if condition is not None: + query = query.filter(condition) + return query + + +def model_query(session, model): + """model query. + + Return sqlalchemy query object. + """ + if not issubclass(model, models.BASE): + raise exception.DatabaseException("model should be sublass of BASE!") + + return session.query(model) + + +def wrap_to_dict(support_keys=[], **filters): + """Decrator to convert returned object to dict. + + The details is decribed in _wrapper_dict. + """ + def decorator(func): + @functools.wraps(func) + def wrapper(*args, **kwargs): + return _wrapper_dict( + func(*args, **kwargs), support_keys, **filters + ) + return wrapper + return decorator + + +def _wrapper_dict(data, support_keys, **filters): + """Helper for warpping db object into dictionary. + + If data is list, convert it to a list of dict + If data is Base model, convert it to dict + for the data as a dict, filter it with the supported keys. + For each filter_key, filter_value in filters, also filter + data[filter_key] by filter_value recursively if it exists. + + Example: + data is models.Switch, it will be converted to + { + 'id': 1, 'ip': '10.0.0.1', 'ip_int': 123456, + 'credentials': {'version': 2, 'password': 'abc'} + } + Then if support_keys are ['id', 'ip', 'credentials'], + it will be filtered to { + 'id': 1, 'ip': '10.0.0.1', + 'credentials': {'version': 2, 'password': 'abc'} + } + Then if filters is {'credentials': ['version']}, + it will be filtered to { + 'id': 1, 'ip': '10.0.0.1', + 'credentials': {'version': 2} + } + """ + logging.debug( + 'wrap dict %s by support_keys=%s filters=%s', + data, support_keys, filters + ) + if isinstance(data, list): + return [ + _wrapper_dict(item, support_keys, **filters) + for item in data + ] + if isinstance(data, models.ModelHandler): + data = data.to_dict() + if not isinstance(data, dict): + raise exception.InvalidResponse( + 'response %s type is not dict' % data + ) + info = {} + try: + if len(support_keys) == 0: + support_keys = data.keys() + for key in support_keys: + if key in data and data[key] is not None: + if key in filters: + filter_keys = filters[key] + if isinstance(filter_keys, dict): + info[key] = _wrapper_dict( + data[key], filter_keys.keys(), + **filter_keys + ) + else: + info[key] = _wrapper_dict( + data[key], filter_keys + ) + else: + info[key] = data[key] + return info + except Exception as error: + logging.exception(error) + raise error |