d72659088f
Config now supports full hierarchical and overlay-capable usage. A generic tree overlay function is in aux.
94 lines
2.1 KiB
Python
94 lines
2.1 KiB
Python
#! /usr/bin/env python3
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# encoding: utf-8
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import jsmin
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import json
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from . import aux
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def _read_json(path):
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"""
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Reads a data structure from a JSON file pointed to by `path`.
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Removes any C/JS-like comments from it.
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"""
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with open(path) as f:
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return json.loads(jsmin.jsmin(f.read()))
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class Config:
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"""
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A hierarchical key-value container that can be loaded from JSON or a Python dict.
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Any contained dicts are automatically converted to Config instances as well.
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Supports sequential overwriting - so one can load a default config and then
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progressively overlay more on top:
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>>> c = Config.from_file("/usr/lib/app/default.cfg")
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>>> c.update_from_file("/etc/app/config.cfg")
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>>> c.update({"key", value, "subtree": {"key": "value"}})
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"""
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def __init__(self, d=None, readonly=False):
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if d is None:
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d = {}
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assert type(d) == dict
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object.__setattr__(self, "raw", d)
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object.__setattr__(self, "readonly", readonly)
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@classmethod
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def from_file(cls, path, readonly=False):
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return cls(_read_json(path), readonly)
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def update(self, d):
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aux.overlay_tree(self.raw, d)
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def update_from_file(self, path):
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self.update(_read_json(path))
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def keys(self):
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return self.raw.keys()
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def values(self):
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return self.raw.values()
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def items(self):
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return self.raw.items()
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def __getitem__(self, name):
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return self.raw[name]
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def __setitem__(self, name, value):
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if self.readonly:
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raise AttributeError("config is read-only")
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self.raw[name] = value
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def __setattr__(self, name, value):
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if self.readonly:
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raise AttributeError("config is read-only")
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self.raw[name] = value
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def __getattr__(self, name):
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matches = [key for key in self.raw if key.replace("-", "_") == name]
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if matches:
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assert len(matches) == 1
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value = self.raw[matches[0]]
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if type(value) == dict:
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return Config(value)
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else:
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return value
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else:
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raise KeyError(name)
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def __contains__(self, name):
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return name in self.raw
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def __repr__(self):
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return "Config(%s)" %(" ".join("%s=%s" %(k, "…" if type(v) == dict else v) for k, v in self.raw.items()))
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