| 12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788 |
- """Manager to read and modify config data in JSON files.
- """
- # Copyright (c) IPython Development Team.
- # Distributed under the terms of the Modified BSD License.
- import errno
- import io
- import json
- import os
- from six import PY3
- from traitlets.config import LoggingConfigurable
- from traitlets.traitlets import Unicode
- def recursive_update(target, new):
- """Recursively update one dictionary using another.
- None values will delete their keys.
- """
- for k, v in new.items():
- if isinstance(v, dict):
- if k not in target:
- target[k] = {}
- recursive_update(target[k], v)
- if not target[k]:
- # Prune empty subdicts
- del target[k]
- elif v is None:
- target.pop(k, None)
- else:
- target[k] = v
- class BaseJSONConfigManager(LoggingConfigurable):
- """General JSON config manager
-
- Deals with persisting/storing config in a json file
- """
- config_dir = Unicode('.')
- def ensure_config_dir_exists(self):
- try:
- os.makedirs(self.config_dir, 0o755)
- except OSError as e:
- if e.errno != errno.EEXIST:
- raise
- def file_name(self, section_name):
- return os.path.join(self.config_dir, section_name+'.json')
- def get(self, section_name):
- """Retrieve the config data for the specified section.
- Returns the data as a dictionary, or an empty dictionary if the file
- doesn't exist.
- """
- filename = self.file_name(section_name)
- if os.path.isfile(filename):
- with io.open(filename, encoding='utf-8') as f:
- return json.load(f)
- else:
- return {}
- def set(self, section_name, data):
- """Store the given config data.
- """
- filename = self.file_name(section_name)
- self.ensure_config_dir_exists()
- if PY3:
- f = io.open(filename, 'w', encoding='utf-8')
- else:
- f = open(filename, 'wb')
- with f:
- json.dump(data, f, indent=2)
- def update(self, section_name, new_data):
- """Modify the config section by recursively updating it with new_data.
- Returns the modified config data as a dictionary.
- """
- data = self.get(section_name)
- recursive_update(data, new_data)
- self.set(section_name, data)
- return data
|
