# Copyright (c) 2016-2017,2019 Weitian LI # MIT License # # References: # [1] https://configobj.readthedocs.io/en/latest/configobj.html # [2] https://github.com/pazz/alot/blob/master/alot/settings/manager.py """ Configuration manager. """ import os import sys import logging from logging import FileHandler, StreamHandler import operator from functools import reduce from collections import MutableMapping import pkg_resources import copy import shutil from configobj import ConfigObj, ConfigObjError, flatten_errors from validate import Validator import numpy as np from .checkers import check_configs from ..errors import ConfigError logger = logging.getLogger(__name__) def _flatten_dict(d, sep="/", parent_key=""): """ Recursively flatten a nested dictionary with keys compressed. The dictionary is recursively flattened into a one-level dictionary, i.e., all the leaves are raised to the top level. For each leaf, the value is simply preserved, while its keys list is compressed into a single key by concatenating with a separator. Parameters ---------- d : dict Input nested dictionary. sep : str, optional The separator used to concatenate the keys for each leaf item. parent_key : str, optional The parent key string that will be prepended to the flatten key string when flattening the dictionary. NOTE: This parameter is required for the recursion, so user can simply ignore this.. Returns ------- flatdict : dict The flattened dictionary. Examples -------- - Input nested dictionary: {'a': 1, 'c': {'a': 2, 'b': {'x': 5, 'y': 10}}, 'd': [1, 2, 3]} - Output flatten dictionary: {'a': 1, 'c/a': 2, 'c/b/x': 5, 'c/b/y': 10, 'd': [1, 2, 3]} Credit: http://stackoverflow.com/a/6027615 """ items = [] for k, v in d.items(): new_key = (parent_key + sep + k) if parent_key else k if isinstance(v, MutableMapping): items.extend(_flatten_dict(v, sep=sep, parent_key=new_key).items()) else: items.append((new_key, v)) return dict(items) class ConfigManager: """ Manage the default configurations with specifications, as well as the user configurations. Both the default configurations and user configurations are validated against the bundled specifications. Parameters ---------- userconfig: str, optional Filename/path to the user configuration file. If provided, the user configurations is also loaded, validated, and merged into the configurations data. The user configuration can also be later loaded by ``self.read_userconfig()``. Attributes ---------- _config : `~configobj.ConfigObj` The current effective configurations. _configspec : `~configobj.ConfigObj` The configuration specifications bundled with this package. userconfig : str The filename and path to the user-provided configurations. NOTE: - This attribute has valid value only after loading the user configuration by ``self.read_userconfig()``; - This attribute is used to determine the absolute path of the configs specifying the input templates or data files, therefore allow the use of relative path for those config options. """ # Path to the user provided configuration file, which indicates user # configurations merged if not ``None``. userconfig = None def __init__(self, userconfig=None): """ Load the bundled default configurations and specifications. If the ``userconfig`` provided, the user configurations is also loaded, validated, and merged. """ configspec = pkg_resources.resource_stream(__name__, "config.spec") self._configspec = ConfigObj(configspec, interpolation=False, list_values=False, _inspec=True, encoding="utf-8") configs_default = ConfigObj(interpolation=False, configspec=self._configspec, encoding="utf-8") # Keep a copy of the default configurations self._config_default = self._validate(configs_default) # NOTE: use ``copy.deepcopy``; see also ``self.reset()``. self._config = copy.deepcopy(self._config_default) if userconfig: self.read_userconfig(userconfig) def merge(self, config): """ Simply merge the given configurations without validation. Parameters ---------- config : `~configobj.ConfigObj`, dict, str, or list[str] Supplied configurations to be merged. """ if not isinstance(config, ConfigObj): try: config = ConfigObj(config, interpolation=False, encoding="utf-8") except ConfigObjError as e: logger.exception(e) raise ConfigError(e) self._config.merge(config) def read_config(self, config): """ Read, validate and merge the input config. Parameters ---------- config : str, or list[str] Input config to be validated and merged. This parameter can be the filename of the config file, or a list contains the lines of the configs. """ try: newconfig = ConfigObj(config, interpolation=False, configspec=self._configspec, encoding="utf-8") except ConfigObjError as e: raise ConfigError(e) newconfig = self._validate(newconfig) self.merge(newconfig) logger.info("Loaded additional config") def read_userconfig(self, userconfig, reset=False): """ Read user configuration file, validate, and merge into the default configurations. Parameters ---------- userconfig : str Filename/path to the user configuration file. Generally, an absolute path should be provided. The prefix ``~`` (tilde) is also allowed and will be expanded. reset : bool, optional Whether to reset the loaded configurations before reading in the new user configurations? NOTE: If an user configuration file is already loaded, then it is required to do a reset. Otherwise, an error is raised. Raises ------ ConfigError : An user configuration file is already loaded but ``reset`` is not allowed. """ userconfig = os.path.expanduser(userconfig) try: config = open(userconfig).read().split("\n") except IOError: raise ConfigError("Cannot read config from '%s'" % userconfig) if self.userconfig: if not reset: raise ConfigError("User configurations already loaded " + "from '%s'" % self.userconfig) else: self.reset() self.read_config(config) self.userconfig = os.path.abspath(userconfig) logger.info("Loaded user config: {0}".format(self.userconfig)) def reset(self): """ Reset the current configurations to the copy of defaults from the specification. The ``self.userconfig`` is also cleared. NOTE ---- * ``_config_default.copy()`` only returns a *shallow* copy. * ``ConfigObj(_config_default)`` will lost all comments. """ self._config = copy.deepcopy(self._config_default) self.userconfig = None logger.warning("Reset the configurations to the copy of defaults!") def _validate(self, config): """ Validate the config against the specification using a default validator. The validated config values are returned if success, otherwise, the ``ConfigError`` raised with details. """ validator = Validator() try: # NOTE: # Use the "copy" mode, which will copy both the default values # and all the comments. results = config.validate(validator, preserve_errors=True, copy=True) except ConfigObjError as e: raise ConfigError(e) if results is not True: error_msg = "" for (section_list, key, res) in flatten_errors(config, results): if key is not None: if res is False: msg = 'key "%s" in section "%s" is missing.' msg = msg % (key, ", ".join(section_list)) else: msg = 'key "%s" in section "%s" failed validation: %s' msg = msg % (key, ", ".join(section_list), res) else: msg = 'section "%s" is missing' % ".".join(section_list) error_msg += msg + "\n" raise ConfigError(error_msg) return config def check_all(self, raise_exception=True): """ Further check the whole configurations through a set of custom checker functions, which may check one config option against its context if necessary to determine whether it has a valid value. Parameters ---------- raise_exception : bool, optional Whether raise a ``ConfigError`` exception if there is any invalid config options? Returns ------- result : bool ``True`` if the configurations pass all checker functions. errors : dict An dictionary containing the details about the invalid config options, with the keys identifying the config options and values indicating the error message. If above ``result=True``, then this is an empty dictionary ``{}``. Raises ------ ConfigError If any config option failed to pass any of the checkers, a ``ConfigError`` with details is raised. """ result, errors = check_configs(self, raise_exception=raise_exception) return (result, errors) def get(self, key, fallback=None, from_default=False): """Get config value by key.""" if from_default: config = self._config_default else: config = self._config return config.get(key, fallback) def getn(self, key, from_default=False): """ Get the value of a config option specified by the input key from from the configurations which is a nested dictionary. Parameters ---------- key : str, or list[str] List of keys or a string of keys separated by a the ``/`` character to specify the item in the ``self._config``, which is a nested dictionary. e.g., ``["section1", "key2"]``, ``"section1/key2"`` from_default : bool, optional If True, get the config option value from the *default* configurations, other than the configurations merged with user configurations (default). Raises ------ KeyError : The input key specifies a non-exist config option. References ---------- - Stackoverflow: Checking a Dictionary using a dot notation string https://stackoverflow.com/q/12414821/4856091 https://stackoverflow.com/a/12414913/4856091 """ if isinstance(key, str): key = key.split("/") if from_default: config = self._config_default else: config = self._config try: return reduce(operator.getitem, key, config) except (KeyError, TypeError): raise KeyError("%s: invalid key" % "/".join(key)) def setn(self, key, value): """ Set the value of config option specified by a list of keys or a "/"-separated keys string. The supplied key-value config pair is first used to create a temporary ``ConfigObj`` instance, which is then validated against the configuration specifications. If validated to be *valid*, the input key-value pair is then *merged* into the configurations, otherwise, a ``ConfigError`` raised. NOTE ---- Given a ``ConfigObj`` instance with an option that does NOT exist in the specifications, it will simply *pass* the validation. There seems no way to prevent the ``Validator`` from accepting the config options that does NOT exist in the specification. Therefore, try to get the option value specified by the input key first, if no ``KeyError`` raised, then it is a valid key. Parameters ---------- key : str, or list[str] List of keys or a string of keys separated by a the ``/`` character to specify the item in the ``self._config``, which is a nested dictionary. e.g., ``["section1", "key2"]``, ``"section1/key2"`` value : str, bool, int, float, list The value can be any acceptable type to ``ConfigObj``. Raises ------ KeyError : The input key specifies a non-exist config option. ConfigError : The value fails to pass the validation against specifications. """ # NOTE: # May raise ``KeyError`` if the key does not exists val_old = self.getn(key) if val_old == value: # No need to set this option value return # Create a nested dictionary from the input key-value pair # Credit: # * Stackoverflow: Convert a list into a nested dictionary # https://stackoverflow.com/a/6689604/4856091 if isinstance(key, str): key = key.split("/") d = reduce(lambda x, y: {y: x}, reversed(key), value) # Create the temporary ``ConfigObj`` instance and validate it config_new = ConfigObj(d, interpolation=False, configspec=self._configspec, encoding="utf-8") # NOTE: # May raise ``ConfigError`` if fails to pass the validation config_new = self._validate(config_new) # NOTE: # The validated ``config_new`` is populated with all other options # from the specifications. val_new = reduce(operator.getitem, key, config_new) d2 = reduce(lambda x, y: {y: x}, reversed(key), val_new) self.merge(d2) logger.info("Set config: {key}: {val_old} -> {val_new}".format( key="/".join(key), val_new=val_new, val_old=val_old)) def __getitem__(self, key): return self.getn(key=key) def __setitem__(self, key, value): self.setn(key=key, value=value) def get_path(self, key): """ Return the absolute path of the file/directory specified by the config keys. Parameters ---------- key : str "/"-separated string specifying the config name of the file/directory Returns ------- path : str The absolute path (if user configuration loaded) or relative path specified by the input key, or ``None`` if the specified config has value of ``None`` or an empty string. Raises ------ ValueError: If the value of the specified config is not string. NOTE ---- - The beginning ``~`` (tilde) is expanded to user's home directory. - The relative path (with respect to the user configuration file) is converted to absolute path if ``self.userconfig`` is valid. """ value = self.getn(key) if value is None: logger.warning("Specified config '%s' is None or not exist" % key) return None if value == "": logger.warning("Specified config '%s' is an empty string" % key) return None if not isinstance(value, str): msg = "Specified config '%s' is non-string: %s" % (key, value) logger.error(msg) raise ValueError(msg) path = os.path.expanduser(value) if not os.path.isabs(path): # Got a relative path, try to convert to the absolute path if self.userconfig is not None: # User configuration loaded path = os.path.join(os.path.dirname(self.userconfig), path) else: logger.warning("Cannot convert to absolute path: %s" % path) return os.path.normpath(path) @property def foregrounds(self): """ Get all available and enabled foreground components. Returns ------- enabled : list[str] Enabled foreground components to be simulated available : list[str] All available foreground components """ fg = self.get("foregrounds") avaliable = list(fg.keys()) enabled = [key for key, value in fg.items() if value] return (enabled, avaliable) @property def frequencies(self): """ Get or calculate if ``frequency/type = custom`` the frequencies where to perform the simulations. Returns ------- frequencies : 1D `~numpy.ndarray` List of frequencies where to simulate the foreground. Unit: [MHz] """ if self.getn("frequency/type") == "custom": # The value is validated to be a float list frequencies = np.array(self.getn("frequency/frequencies")) else: # Calculate the frequency values, including the stop frequency start = self.getn("frequency/start") stop = self.getn("frequency/stop") step = self.getn("frequency/step") frequencies = np.arange(start, stop+step/2, step) return frequencies @property def logging(self): """ Get and prepare the logging configurations for ``logging.basicConfig()`` to initialize the logging module. """ conf = self.get("logging") level = conf["level"].upper() if os.environ.get("DEBUG_FG21SIM"): print("DEBUG: Force 'DEBUG' logging level", file=sys.stderr) level = "DEBUG" # logging handlers handlers = [] stream = conf["stream"] if stream: handlers.append(StreamHandler(getattr(sys, stream))) logfile = conf["filename"] if logfile: handlers.append(FileHandler(logfile)) # Explicitly add the formatter to each handler formatter = logging.Formatter(fmt=conf["format"], datefmt=conf["datefmt"]) for handler in handlers: handler.setFormatter(formatter) logconf = { "level": getattr(logging, level), "format": conf["format"], "datefmt": conf["datefmt"], "handlers": handlers, } return logconf @property def cosmology(self): """ Get the cosmological parameters and organize them as an dictionary for ``Cosmology`` initialization. """ conf = self.get("cosmology") cosmoconf = { "H0": conf["H0"], "Om0": conf["OmegaM0"], "Ob0": conf["Omegab0"], "Tcmb0": conf["Tcmb0"], "ns": conf["ns"], "sigma8": conf["sigma8"], } return cosmoconf def dump(self, from_default=False, flatten=False): """ Dump the configurations as a plain Python dictionary. Parameters ---------- from_default : bool, optional If ``True``, dump the default configurations (as specified by the bundled specifications); otherwise, dump the configurations with user-supplied options merged (default). flatten : bool, optional If ``True``, flatten the configurations with is a nested dictionary into an one-level flat dictionary, make it much easier for client's manipulations. NOTE ---- * The original option orders are missing. * The ``self.userconfig`` property is included. """ if from_default: data = self._config_default.dict() else: data = self._config.dict() data["userconfig"] = self.userconfig if flatten: data = _flatten_dict(data) return data def save(self, outfile=None, clobber=False): """ Save the configurations to file. Parameters ---------- outfile : str, optional The path to the output configuration file. If not provided, then use ``self.userconfig``, however, set ``clobber=True`` may be required. NOTE: Must be an *absolute path*. clobber : bool, optional Whether to backup existing output file and overwrite it? Raises ------ ValueError : The given ``outfile`` is not an *absolute path*, or the ``self.userconfig`` is invalid while the ``outfile`` not given. OSError : If the target filename already exists. """ if outfile is None: if self.userconfig is None: raise ValueError("no outfile and self.userconfig is None") else: outfile = self.userconfig logger.warning("outfile not provided, " + "use self.userconfig: {0}".format(outfile)) outfile = os.path.expanduser(outfile) if not os.path.isabs(outfile): raise ValueError("not an absolute path: {0}".format(outfile)) if os.path.exists(outfile): if clobber: backfile = outfile + ".old" shutil.copyfile(outfile, backfile) logger.info("Backed up old configuration file as: " + backfile) else: raise OSError("outfile already exists: {0}".format(outfile)) with open(outfile, "wb") as f: # binary mode required self._config.indent_type = " " self._config.write(f)