+import yaml
from http import HTTPStatus
+from copy import deepcopy
__author__ = "Alfonso Tierno <alfonso.tiernosepulveda@telefonica.com>"
class DbException(Exception):
def __init__(self, message, http_code=HTTPStatus.NOT_FOUND):
+ # TODO change to http.HTTPStatus instead of int that allows .value and .name
self.http_code = http_code
Exception.__init__(self, "database exception " + message)
pass
def get_list(self, table, filter={}):
- pass
+ raise DbException("Method 'get_list' not implemented")
def get_one(self, table, filter={}, fail_on_empty=True, fail_on_more=True):
- pass
+ raise DbException("Method 'get_one' not implemented")
def create(self, table, indata):
- pass
+ raise DbException("Method 'create' not implemented")
def del_list(self, table, filter={}):
- pass
+ raise DbException("Method 'del_list' not implemented")
def del_one(self, table, filter={}, fail_on_empty=True):
- pass
+ raise DbException("Method 'del_one' not implemented")
+
+
+def deep_update(dict_to_change, dict_reference, key_list=None):
+ """
+ Modifies one dictionary with the information of the other following https://tools.ietf.org/html/rfc7396
+ Basically is a recursive python 'dict_to_change.update(dict_reference)', but a value of None is used to delete.
+ It implements an extra feature that allows modifying an array. RFC7396 only allows replacing the entire array.
+ For that, dict_reference should contains a dict with keys starting by "$" with the following meaning:
+ $[index] <index> is an integer for targeting a concrete index from dict_to_change array. If the value is None
+ the element of the array is deleted, otherwise it is edited.
+ $+[index] The value is inserted at this <index>. A value of None has not sense and an exception is raised.
+ $+ The value is appended at the end. A value of None has not sense and an exception is raised.
+ $val It looks for all the items in the array dict_to_change equal to <val>. <val> is evaluated as yaml,
+ that is, numbers are taken as type int, true/false as boolean, etc. Use quotes to force string.
+ Nothing happens if no match is found. If the value is None the matched elements are deleted.
+ $key: val In case a dictionary is passed in yaml format, if looks for all items in the array dict_to_change
+ that are dictionaries and contains this <key> equal to <val>. Several keys can be used by yaml
+ format '{key: val, key: val, ...}'; and all of them mast match. Nothing happens if no match is
+ found. If value is None the matched items are deleted, otherwise they are edited.
+ $+val If no match if found (see '$val'), the value is appended to the array. If any match is found nothing
+ is changed. A value of None has not sense.
+ $+key: val If no match if found (see '$key: val'), the value is appended to the array. If any match is found
+ nothing is changed. A value of None has not sense.
+ If there are several editions, insertions and deletions; editions and deletions are done first in reverse index
+ order; then insertions also in reverse index order; and finally appends in any order. So indexes used at
+ insertions must take into account the deleted items.
+ :param dict_to_change: Target dictionary to be changed.
+ :param dict_reference: Dictionary that contains changes to be applied.
+ :param key_list: This is used internally for recursive calls. Do not fill this parameter.
+ :return: none or raises and exception only at array modification when there is a bad format or conflict.
+ """
+ def _deep_update_array(array_to_change, _dict_reference, _key_list):
+ to_append = {}
+ to_insert_at_index = {}
+ values_to_edit_delete = {}
+ indexes_to_edit_delete = []
+ array_edition = None
+ _key_list.append("")
+ for k in _dict_reference:
+ _key_list[-1] = str(k)
+ if not isinstance(k, str) or not k.startswith("$"):
+ if array_edition is True:
+ raise DbException("Found array edition (keys starting with '$') and pure dictionary edition in the"
+ " same dict at '{}'".format(":".join(_key_list[:-1])))
+ array_edition = False
+ continue
+ else:
+ if array_edition is False:
+ raise DbException("Found array edition (keys starting with '$') and pure dictionary edition in the"
+ " same dict at '{}'".format(":".join(_key_list[:-1])))
+ array_edition = True
+ insert = False
+ indexes = [] # indexes to edit or insert
+ kitem = k[1:]
+ if kitem.startswith('+'):
+ insert = True
+ kitem = kitem[1:]
+ if _dict_reference[k] is None:
+ raise DbException("A value of None has not sense for insertions at '{}'".format(
+ ":".join(_key_list)))
+
+ if kitem.startswith('[') and kitem.endswith(']'):
+ try:
+ index = int(kitem[1:-1])
+ if index < 0:
+ index += len(array_to_change)
+ if index < 0:
+ index = 0 # skip outside index edition
+ indexes.append(index)
+ except Exception:
+ raise DbException("Wrong format at '{}'. Expecting integer index inside quotes".format(
+ ":".join(_key_list)))
+ elif kitem:
+ # match_found_skip = False
+ try:
+ filter_in = yaml.safe_load(kitem)
+ except Exception:
+ raise DbException("Wrong format at '{}'. Expecting '$<yaml-format>'".format(":".join(_key_list)))
+ if isinstance(filter_in, dict):
+ for index, item in enumerate(array_to_change):
+ for filter_k, filter_v in filter_in.items():
+ if not isinstance(item, dict) or filter_k not in item or item[filter_k] != filter_v:
+ break
+ else: # match found
+ if insert:
+ # match_found_skip = True
+ insert = False
+ break
+ else:
+ indexes.append(index)
+ else:
+ index = 0
+ try:
+ while True: # if not match a ValueError exception will be raise
+ index = array_to_change.index(filter_in, index)
+ if insert:
+ # match_found_skip = True
+ insert = False
+ break
+ indexes.append(index)
+ index += 1
+ except ValueError:
+ pass
+
+ # if match_found_skip:
+ # continue
+ elif not insert:
+ raise DbException("Wrong format at '{}'. Expecting '$+', '$[<index]' or '$[<filter>]'".format(
+ ":".join(_key_list)))
+ for index in indexes:
+ if insert:
+ if index in to_insert_at_index and to_insert_at_index[index] != _dict_reference[k]:
+ # Several different insertions on the same item of the array
+ raise DbException("Conflict at '{}'. Several insertions on same array index {}".format(
+ ":".join(_key_list), index))
+ to_insert_at_index[index] = _dict_reference[k]
+ else:
+ if index in indexes_to_edit_delete and values_to_edit_delete[index] != _dict_reference[k]:
+ # Several different editions on the same item of the array
+ raise DbException("Conflict at '{}'. Several editions on array index {}".format(
+ ":".join(_key_list), index))
+ indexes_to_edit_delete.append(index)
+ values_to_edit_delete[index] = _dict_reference[k]
+ if not indexes:
+ if insert:
+ to_append[k] = _dict_reference[k]
+ # elif _dict_reference[k] is not None:
+ # raise DbException("Not found any match to edit in the array, or wrong format at '{}'".format(
+ # ":".join(_key_list)))
+
+ # edition/deletion is done before insertion
+ indexes_to_edit_delete.sort(reverse=True)
+ for index in indexes_to_edit_delete:
+ _key_list[-1] = str(index)
+ try:
+ if values_to_edit_delete[index] is None: # None->Anything
+ try:
+ del (array_to_change[index])
+ except IndexError:
+ pass # it is not consider an error if this index does not exist
+ elif not isinstance(values_to_edit_delete[index], dict): # NotDict->Anything
+ array_to_change[index] = deepcopy(values_to_edit_delete[index])
+ elif isinstance(array_to_change[index], dict): # Dict->Dict
+ deep_update(array_to_change[index], values_to_edit_delete[index], _key_list)
+ else: # Dict->NotDict
+ if isinstance(array_to_change[index], list): # Dict->List. Check extra array edition
+ if _deep_update_array(array_to_change[index], values_to_edit_delete[index], _key_list):
+ continue
+ array_to_change[index] = deepcopy(values_to_edit_delete[index])
+ # calling deep_update to delete the None values
+ deep_update(array_to_change[index], values_to_edit_delete[index], _key_list)
+ except IndexError:
+ raise DbException("Array edition index out of range at '{}'".format(":".join(_key_list)))
+
+ # insertion with indexes
+ to_insert_indexes = list(to_insert_at_index.keys())
+ to_insert_indexes.sort(reverse=True)
+ for index in to_insert_indexes:
+ array_to_change.insert(index, to_insert_at_index[index])
+
+ # append
+ for k, insert_value in to_append.items():
+ _key_list[-1] = str(k)
+ insert_value_copy = deepcopy(insert_value)
+ if isinstance(insert_value_copy, dict):
+ # calling deep_update to delete the None values
+ deep_update(insert_value_copy, insert_value, _key_list)
+ array_to_change.append(insert_value_copy)
+
+ _key_list.pop()
+ if array_edition:
+ return True
+ return False
+
+ if key_list is None:
+ key_list = []
+ key_list.append("")
+ for k in dict_reference:
+ key_list[-1] = str(k)
+ if dict_reference[k] is None: # None->Anything
+ if k in dict_to_change:
+ del dict_to_change[k]
+ elif not isinstance(dict_reference[k], dict): # NotDict->Anything
+ dict_to_change[k] = deepcopy(dict_reference[k])
+ elif k not in dict_to_change: # Dict->Empty
+ dict_to_change[k] = deepcopy(dict_reference[k])
+ # calling deep_update to delete the None values
+ deep_update(dict_to_change[k], dict_reference[k], key_list)
+ elif isinstance(dict_to_change[k], dict): # Dict->Dict
+ deep_update(dict_to_change[k], dict_reference[k], key_list)
+ else: # Dict->NotDict
+ if isinstance(dict_to_change[k], list): # Dict->List. Check extra array edition
+ if _deep_update_array(dict_to_change[k], dict_reference[k], key_list):
+ continue
+ dict_to_change[k] = deepcopy(dict_reference[k])
+ # calling deep_update to delete the None values
+ deep_update(dict_to_change[k], dict_reference[k], key_list)
+ key_list.pop()
projects / osm / common.git / blobdiff