taipy/taipy/core/data/pickle.py

# Copyright 2021-2024 Avaiga Private Limited
#
# 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 os
import pickle
from datetime import datetime, timedelta
from typing import Any, List, Optional, Set

from taipy.config.common.scope import Scope

from .._backup._backup import _replace_in_backup_file
from .._entity._reload import _self_reload
from .._version._version_manager_factory import _VersionManagerFactory
from ._abstract_file import _AbstractFileDataNode
from .data_node import DataNode
from .data_node_id import DataNodeId, Edit


class PickleDataNode(DataNode, _AbstractFileDataNode):
    """Data Node stored as a pickle file.

    Attributes:
        config_id (str): Identifier of the data node configuration. It must be a valid Python
            identifier.
        scope (Scope^): The scope of this data node.
        id (str): The unique identifier of this data node.
        owner_id (str): The identifier of the owner (sequence_id, scenario_id, cycle_id) or
            `None`.
        parent_ids (Optional[Set[str]]): The identifiers of the parent tasks or `None`.
        last_edit_date (datetime): The date and time of the last modification.
        edits (List[Edit^]): The ordered list of edits for that job.
        version (str): The string indicates the application version of the data node to instantiate. If not provided,
            the current version is used.
        validity_period (Optional[timedelta]): The duration implemented as a timedelta since the last edit date for
            which the data node can be considered up-to-date. Once the validity period has passed, the data node is
            considered stale and relevant tasks will run even if they are skippable (see the
            [Task management page](../core/entities/task-mgt.md) for more details).
            If _validity_period_ is set to `None`, the data node is always up-to-date.
        edit_in_progress (bool): True if a task computing the data node has been submitted
            and not completed yet. False otherwise.
        editor_id (Optional[str]): The identifier of the user who is currently editing the data node.
        editor_expiration_date (Optional[datetime]): The expiration date of the editor lock.
        properties (dict[str, Any]): A dictionary of additional properties.
            When creating a pickle data node, if the _properties_ dictionary contains a
            _"default_data"_ entry, the data node is automatically written with the corresponding
            _"default_data"_ value.
            If the _properties_ dictionary contains a _"default_path"_ or _"path"_ entry, the data will be stored
            using the corresponding value as the name of the pickle file.
    """

    __STORAGE_TYPE = "pickle"
    __PATH_KEY = "path"
    __DEFAULT_PATH_KEY = "default_path"
    __DEFAULT_DATA_KEY = "default_data"
    __IS_GENERATED_KEY = "is_generated"
    _REQUIRED_PROPERTIES: List[str] = []

    def __init__(
        self,
        config_id: str,
        scope: Scope,
        id: Optional[DataNodeId] = None,
        owner_id: Optional[str] = None,
        parent_ids: Optional[Set[str]] = None,
        last_edit_date: Optional[datetime] = None,
        edits: Optional[List[Edit]] = None,
        version: str = None,
        validity_period: Optional[timedelta] = None,
        edit_in_progress: bool = False,
        editor_id: Optional[str] = None,
        editor_expiration_date: Optional[datetime] = None,
        properties=None,
    ):
        if properties is None:
            properties = {}
        default_value = properties.pop(self.__DEFAULT_DATA_KEY, None)
        self._path = properties.get(self.__PATH_KEY, properties.get(self.__DEFAULT_PATH_KEY))
        if self._path is not None:
            properties[self.__PATH_KEY] = self._path
        self._is_generated = properties.get(self.__IS_GENERATED_KEY, self._path is None)
        properties[self.__IS_GENERATED_KEY] = self._is_generated
        super().__init__(
            config_id,
            scope,
            id,
            owner_id,
            parent_ids,
            last_edit_date,
            edits,
            version or _VersionManagerFactory._build_manager()._get_latest_version(),
            validity_period,
            edit_in_progress,
            editor_id,
            editor_expiration_date,
            **properties,
        )
        if self._path is None:
            self._path = self._build_path(self.storage_type())
        if not self._last_edit_date and os.path.exists(self._path):
            self._last_edit_date = datetime.now()
        if default_value is not None and not os.path.exists(self._path):
            self._write(default_value)
            self._last_edit_date = datetime.now()
            self._edits.append(
                Edit(
                    {
                        "timestamp": self._last_edit_date,
                        "writer_identifier": "TAIPY",
                        "comments": "Default data written.",
                    }
                )
            )

        self._TAIPY_PROPERTIES.update(
            {
                self.__PATH_KEY,
                self.__DEFAULT_PATH_KEY,
                self.__DEFAULT_DATA_KEY,
                self.__IS_GENERATED_KEY,
            }
        )

    @classmethod
    def storage_type(cls) -> str:
        return cls.__STORAGE_TYPE

    @property  # type: ignore
    @_self_reload(DataNode._MANAGER_NAME)
    def path(self) -> Any:
        return self._path

    @path.setter
    def path(self, value):
        tmp_old_path = self._path
        self._path = value
        self.properties[self.__PATH_KEY] = value
        self.properties[self.__IS_GENERATED_KEY] = False
        _replace_in_backup_file(old_file_path=tmp_old_path, new_file_path=self._path)

    @property  # type: ignore
    @_self_reload(DataNode._MANAGER_NAME)
    def is_generated(self) -> bool:
        return self._is_generated

    def _read(self):
        with open(self._path, "rb") as pf:
            return pickle.load(pf)

    def _write(self, data):
        with open(self._path, "wb") as pf:
            pickle.dump(data, pf)