osm_common/dbmemory.py

   1 # -*- coding: utf-8 -*-
   2
   3 # Copyright 2018 Telefonica S.A.
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #    http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
  14 # implied.
  15 # See the License for the specific language governing permissions and
  16 # limitations under the License.
  17
  18 import logging
  19 from osm_common.dbbase import DbException, DbBase
  20 from osm_common.dbmongo import deep_update
  21 from http import HTTPStatus
  22 from uuid import uuid4
  23 from copy import deepcopy
  24
  25 __author__ = "Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>"
  26
  27
  28 class DbMemory(DbBase):
  29
  30     def __init__(self, logger_name='db', lock=False):
  31         super().__init__(logger_name, lock)
  32         self.db = {}
  33
  34     def db_connect(self, config):
  35         """
  36         Connect to database
  37         :param config: Configuration of database
  38         :return: None or raises DbException on error
  39         """
  40         if "logger_name" in config:
  41             self.logger = logging.getLogger(config["logger_name"])
  42         master_key = config.get("commonkey") or config.get("masterpassword")
  43         if master_key:
  44             self.set_secret_key(master_key)
  45
  46     @staticmethod
  47     def _format_filter(q_filter):
  48         db_filter = {}
  49         # split keys with ANYINDEX in this way:
  50         # {"A.B.ANYINDEX.C.D.ANYINDEX.E": v }  -> {"A.B.ANYINDEX": {"C.D.ANYINDEX": {"E": v}}}
  51         if q_filter:
  52             for k, v in q_filter.items():
  53                 db_v = v
  54                 kleft, _, kright = k.rpartition(".ANYINDEX.")
  55                 while kleft:
  56                     k = kleft + ".ANYINDEX"
  57                     db_v = {kright: db_v}
  58                     kleft, _, kright = k.rpartition(".ANYINDEX.")
  59                 deep_update(db_filter, {k: db_v})
  60
  61         return db_filter
  62
  63     def _find(self, table, q_filter):
  64
  65         def recursive_find(key_list, key_next_index, content, oper, target):
  66             if key_next_index == len(key_list) or content is None:
  67                 try:
  68                     if oper in ("eq", "cont"):
  69                         if isinstance(target, list):
  70                             if isinstance(content, list):
  71                                 return any(content_item in target for content_item in content)
  72                             return content in target
  73                         elif isinstance(content, list):
  74                             return target in content
  75                         else:
  76                             return content == target
  77                     elif oper in ("neq", "ne", "ncont"):
  78                         if isinstance(target, list):
  79                             if isinstance(content, list):
  80                                 return all(content_item not in target for content_item in content)
  81                             return content not in target
  82                         elif isinstance(content, list):
  83                             return target not in content
  84                         else:
  85                             return content != target
  86                     if oper == "gt":
  87                         return content > target
  88                     elif oper == "gte":
  89                         return content >= target
  90                     elif oper == "lt":
  91                         return content < target
  92                     elif oper == "lte":
  93                         return content <= target
  94                     else:
  95                         raise DbException("Unknown filter operator '{}' in key '{}'".
  96                                           format(oper, ".".join(key_list)), http_code=HTTPStatus.BAD_REQUEST)
  97                 except TypeError:
  98                     return False
  99
 100             elif isinstance(content, dict):
 101                 return recursive_find(key_list, key_next_index + 1, content.get(key_list[key_next_index]), oper,
 102                                       target)
 103             elif isinstance(content, list):
 104                 look_for_match = True  # when there is a match return immediately
 105                 if (target is None) != (oper in ("neq", "ne", "ncont")):  # one True and other False (Xor)
 106                     look_for_match = False  # when there is not a match return immediately
 107
 108                 for content_item in content:
 109                     if key_list[key_next_index] == "ANYINDEX" and isinstance(v, dict):
 110                         matches = True
 111                         for k2, v2 in target.items():
 112                             k_new_list = k2.split(".")
 113                             new_operator = "eq"
 114                             if k_new_list[-1] in ("eq", "ne", "gt", "gte", "lt", "lte", "cont", "ncont", "neq"):
 115                                 new_operator = k_new_list.pop()
 116                             if not recursive_find(k_new_list, 0, content_item, new_operator, v2):
 117                                 matches = False
 118                                 break
 119
 120                     else:
 121                         matches = recursive_find(key_list, key_next_index, content_item, oper, target)
 122                     if matches == look_for_match:
 123                         return matches
 124                 if key_list[key_next_index].isdecimal() and int(key_list[key_next_index]) < len(content):
 125                     matches = recursive_find(key_list, key_next_index + 1, content[int(key_list[key_next_index])],
 126                                              oper, target)
 127                     if matches == look_for_match:
 128                         return matches
 129                 return not look_for_match
 130             else:  # content is not dict, nor list neither None, so not found
 131                 if oper in ("neq", "ne", "ncont"):
 132                     return target is not None
 133                 else:
 134                     return target is None
 135
 136         for i, row in enumerate(self.db.get(table, ())):
 137             q_filter = q_filter or {}
 138             for k, v in q_filter.items():
 139                 k_list = k.split(".")
 140                 operator = "eq"
 141                 if k_list[-1] in ("eq", "ne", "gt", "gte", "lt", "lte", "cont", "ncont", "neq"):
 142                     operator = k_list.pop()
 143                 matches = recursive_find(k_list, 0, row, operator, v)
 144                 if not matches:
 145                     break
 146             else:
 147                 # match
 148                 yield i, row
 149
 150     def get_list(self, table, q_filter=None):
 151         """
 152         Obtain a list of entries matching q_filter
 153         :param table: collection or table
 154         :param q_filter: Filter
 155         :return: a list (can be empty) with the found entries. Raises DbException on error
 156         """
 157         try:
 158             result = []
 159             with self.lock:
 160                 for _, row in self._find(table, self._format_filter(q_filter)):
 161                     result.append(deepcopy(row))
 162             return result
 163         except DbException:
 164             raise
 165         except Exception as e:  # TODO refine
 166             raise DbException(str(e))
 167
 168     def count(self, table, q_filter=None):
 169         """
 170         Count the number of entries matching q_filter
 171         :param table: collection or table
 172         :param q_filter: Filter
 173         :return: number of entries found (can be zero)
 174         :raise: DbException on error
 175         """
 176         try:
 177             with self.lock:
 178                 return sum(1 for x in self._find(table, self._format_filter(q_filter)))
 179         except DbException:
 180             raise
 181         except Exception as e:  # TODO refine
 182             raise DbException(str(e))
 183
 184     def get_one(self, table, q_filter=None, fail_on_empty=True, fail_on_more=True):
 185         """
 186         Obtain one entry matching q_filter
 187         :param table: collection or table
 188         :param q_filter: Filter
 189         :param fail_on_empty: If nothing matches filter it returns None unless this flag is set tu True, in which case
 190         it raises a DbException
 191         :param fail_on_more: If more than one matches filter it returns one of then unless this flag is set tu True, so
 192         that it raises a DbException
 193         :return: The requested element, or None
 194         """
 195         try:
 196             result = None
 197             with self.lock:
 198                 for _, row in self._find(table, self._format_filter(q_filter)):
 199                     if not fail_on_more:
 200                         return deepcopy(row)
 201                     if result:
 202                         raise DbException("Found more than one entry with filter='{}'".format(q_filter),
 203                                           HTTPStatus.CONFLICT.value)
 204                     result = row
 205             if not result and fail_on_empty:
 206                 raise DbException("Not found entry with filter='{}'".format(q_filter), HTTPStatus.NOT_FOUND)
 207             return deepcopy(result)
 208         except Exception as e:  # TODO refine
 209             raise DbException(str(e))
 210
 211     def del_list(self, table, q_filter=None):
 212         """
 213         Deletes all entries that match q_filter
 214         :param table: collection or table
 215         :param q_filter: Filter
 216         :return: Dict with the number of entries deleted
 217         """
 218         try:
 219             id_list = []
 220             with self.lock:
 221                 for i, _ in self._find(table, self._format_filter(q_filter)):
 222                     id_list.append(i)
 223             deleted = len(id_list)
 224             for i in reversed(id_list):
 225                 del self.db[table][i]
 226             return {"deleted": deleted}
 227         except DbException:
 228             raise
 229         except Exception as e:  # TODO refine
 230             raise DbException(str(e))
 231
 232     def del_one(self, table, q_filter=None, fail_on_empty=True):
 233         """
 234         Deletes one entry that matches q_filter
 235         :param table: collection or table
 236         :param q_filter: Filter
 237         :param fail_on_empty: If nothing matches filter it returns '0' deleted unless this flag is set tu True, in
 238         which case it raises a DbException
 239         :return: Dict with the number of entries deleted
 240         """
 241         try:
 242             with self.lock:
 243                 for i, _ in self._find(table, self._format_filter(q_filter)):
 244                     break
 245                 else:
 246                     if fail_on_empty:
 247                         raise DbException("Not found entry with filter='{}'".format(q_filter), HTTPStatus.NOT_FOUND)
 248                     return None
 249                 del self.db[table][i]
 250             return {"deleted": 1}
 251         except Exception as e:  # TODO refine
 252             raise DbException(str(e))
 253
 254     def set_one(self, table, q_filter, update_dict, fail_on_empty=True, unset=None, pull=None, push=None):
 255         """
 256         Modifies an entry at database
 257         :param table: collection or table
 258         :param q_filter: Filter
 259         :param update_dict: Plain dictionary with the content to be updated. It is a dot separated keys and a value
 260         :param fail_on_empty: If nothing matches filter it returns None unless this flag is set tu True, in which case
 261         it raises a DbException
 262         :param unset: Plain dictionary with the content to be removed if exist. It is a dot separated keys, value is
 263                       ignored. If not exist, it is ignored
 264         :param pull: Plain dictionary with the content to be removed from an array. It is a dot separated keys and value
 265                      if exist in the array is removed. If not exist, it is ignored
 266         :param push: Plain dictionary with the content to be appended to an array. It is a dot separated keys and value
 267                      is appended to the end of the array
 268         :return: Dict with the number of entries modified. None if no matching is found.
 269         """
 270         try:
 271             with self.lock:
 272                 for i, db_item in self._find(table, self._format_filter(q_filter)):
 273                     break
 274                 else:
 275                     if fail_on_empty:
 276                         raise DbException("Not found entry with _id='{}'".format(q_filter), HTTPStatus.NOT_FOUND)
 277                     return None
 278                 for k, v in update_dict.items():
 279                     db_nested = db_item
 280                     k_list = k.split(".")
 281                     k_item_prev = k_list[0]
 282                     for k_item in k_list[1:]:
 283                         if isinstance(db_nested[k_item_prev], dict):
 284                             if k_item not in db_nested[k_item_prev]:
 285                                 db_nested[k_item_prev][k_item] = None
 286                         elif isinstance(db_nested[k_item_prev], list) and k_item.isdigit():
 287                             # extend list with Nones if index greater than list
 288                             k_item = int(k_item)
 289                             if k_item >= len(db_nested[k_item_prev]):
 290                                 db_nested[k_item_prev] += [None] * (k_item - len(db_nested[k_item_prev]) + 1)
 291                         elif db_nested[k_item_prev] is None:
 292                             db_nested[k_item_prev] = {k_item: None}
 293                         else:  # number, string, boolean, ... or list but with not integer key
 294                             raise DbException("Cannot set '{}' on existing '{}={}'".format(k, k_item_prev,
 295                                                                                            db_nested[k_item_prev]))
 296
 297                         db_nested = db_nested[k_item_prev]
 298                         k_item_prev = k_item
 299
 300                     db_nested[k_item_prev] = v
 301                 return {"updated": 1}
 302         except DbException:
 303             raise
 304         except Exception as e:  # TODO refine
 305             raise DbException(str(e))
 306
 307     def replace(self, table, _id, indata, fail_on_empty=True):
 308         """
 309         Replace the content of an entry
 310         :param table: collection or table
 311         :param _id: internal database id
 312         :param indata: content to replace
 313         :param fail_on_empty: If nothing matches filter it returns None unless this flag is set tu True, in which case
 314         it raises a DbException
 315         :return: Dict with the number of entries replaced
 316         """
 317         try:
 318             with self.lock:
 319                 for i, _ in self._find(table, self._format_filter({"_id": _id})):
 320                     break
 321                 else:
 322                     if fail_on_empty:
 323                         raise DbException("Not found entry with _id='{}'".format(_id), HTTPStatus.NOT_FOUND)
 324                     return None
 325                 self.db[table][i] = deepcopy(indata)
 326             return {"updated": 1}
 327         except DbException:
 328             raise
 329         except Exception as e:  # TODO refine
 330             raise DbException(str(e))
 331
 332     def create(self, table, indata):
 333         """
 334         Add a new entry at database
 335         :param table: collection or table
 336         :param indata: content to be added
 337         :return: database id of the inserted element. Raises a DbException on error
 338         """
 339         try:
 340             id = indata.get("_id")
 341             if not id:
 342                 id = str(uuid4())
 343                 indata["_id"] = id
 344             with self.lock:
 345                 if table not in self.db:
 346                     self.db[table] = []
 347                 self.db[table].append(deepcopy(indata))
 348             return id
 349         except Exception as e:  # TODO refine
 350             raise DbException(str(e))
 351
 352     def create_list(self, table, indata_list):
 353         """
 354         Add a new entry at database
 355         :param table: collection or table
 356         :param indata_list: list content to be added
 357         :return: database ids of the inserted element. Raises a DbException on error
 358         """
 359         try:
 360             _ids = []
 361             with self.lock:
 362                 for indata in indata_list:
 363                     _id = indata.get("_id")
 364                     if not _id:
 365                         _id = str(uuid4())
 366                         indata["_id"] = _id
 367                     with self.lock:
 368                         if table not in self.db:
 369                             self.db[table] = []
 370                         self.db[table].append(deepcopy(indata))
 371                     _ids.append(_id)
 372             return _ids
 373         except Exception as e:  # TODO refine
 374             raise DbException(str(e))
 375
 376
 377 if __name__ == '__main__':
 378     # some test code
 379     db = DbMemory()
 380     db.create("test", {"_id": 1, "data": 1})
 381     db.create("test", {"_id": 2, "data": 2})
 382     db.create("test", {"_id": 3, "data": 3})
 383     print("must be 3 items:", db.get_list("test"))
 384     print("must return item 2:", db.get_list("test", {"_id": 2}))
 385     db.del_one("test", {"_id": 2})
 386     print("must be emtpy:", db.get_list("test", {"_id": 2}))