Viewing file:  storage.py (4.06 KB) -rw-r--r--
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"""Plugin storage class."""
import json
import logging
from typing import Any
from typing import Dict
from certbot import errors
from certbot.compat import filesystem
from certbot.compat import os
logger = logging.getLogger(__name__)
class PluginStorage:
"""Class implementing storage functionality for plugins"""
def __init__(self, config, classkey):
"""Initializes PluginStorage object storing required configuration
options.
:param .configuration.NamespaceConfig config: Configuration object
:param str classkey: class name to use as root key in storage file
"""
self._config = config
self._classkey = classkey
self._initialized = False
self._data: Dict
self._storagepath: str
def _initialize_storage(self):
"""Initializes PluginStorage data and reads current state from the disk
if the storage json exists."""
self._storagepath = os.path.join(self._config.config_dir, ".pluginstorage.json")
self._load()
self._initialized = True
def _load(self):
"""Reads PluginStorage content from the disk to a dict structure
:raises .errors.PluginStorageError: when unable to open or read the file
"""
data: Dict[str, Any] = {}
filedata = ""
try:
with open(self._storagepath, 'r') as fh:
filedata = fh.read()
except IOError as e:
errmsg = "Could not read PluginStorage data file: {0} : {1}".format(
self._storagepath, str(e))
if os.path.isfile(self._storagepath):
# Only error out if file exists, but cannot be read
logger.error(errmsg)
raise errors.PluginStorageError(errmsg)
try:
data = json.loads(filedata)
except ValueError:
if not filedata:
logger.debug("Plugin storage file %s was empty, no values loaded",
self._storagepath)
else:
errmsg = "PluginStorage file {0} is corrupted.".format(
self._storagepath)
logger.error(errmsg)
raise errors.PluginStorageError(errmsg)
self._data = data
def save(self):
"""Saves PluginStorage content to disk
:raises .errors.PluginStorageError: when unable to serialize the data
or write it to the filesystem
"""
if not self._initialized:
errmsg = "Unable to save, no values have been added to PluginStorage."
logger.error(errmsg)
raise errors.PluginStorageError(errmsg)
try:
serialized = json.dumps(self._data)
except TypeError as e:
errmsg = "Could not serialize PluginStorage data: {0}".format(
str(e))
logger.error(errmsg)
raise errors.PluginStorageError(errmsg)
try:
with os.fdopen(filesystem.open(
self._storagepath,
os.O_WRONLY | os.O_CREAT | os.O_TRUNC,
0o600), 'w') as fh:
fh.write(serialized)
except IOError as e:
errmsg = "Could not write PluginStorage data to file {0} : {1}".format(
self._storagepath, str(e))
logger.error(errmsg)
raise errors.PluginStorageError(errmsg)
def put(self, key, value):
"""Put configuration value to PluginStorage
:param str key: Key to store the value to
:param value: Data to store
"""
if not self._initialized:
self._initialize_storage()
if self._classkey not in self._data:
self._data[self._classkey] = {}
self._data[self._classkey][key] = value
def fetch(self, key):
"""Get configuration value from PluginStorage
:param str key: Key to get value from the storage
:raises KeyError: If the key doesn't exist in the storage
"""
if not self._initialized:
self._initialize_storage()
return self._data[self._classkey][key]
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