tiramisu/config.py

   1 # -*- coding: utf-8 -*-
   2 "pretty small and local configuration management tool"
   3 # Copyright (C) 2012 Team tiramisu (see AUTHORS for all contributors)
   4 #
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 #
  19 # The original `Config` design model is unproudly borrowed from
  20 # the rough pypy's guys: http://codespeak.net/svn/pypy/dist/pypy/config/
  21 # the whole pypy projet is under MIT licence
  22 # ____________________________________________________________
  23 from copy import copy
  24 from tiramisu.error import (PropertiesOptionError, ConfigError, NotFoundError,
  25     AmbigousOptionError, ConflictConfigError, NoMatchingOptionFound,
  26     MandatoryError, MethodCallError)
  27 from tiramisu.option import (OptionDescription, Option, SymLinkOption,
  28     group_types, Multi, apply_requires)
  29 from tiramisu.autolib import carry_out_calculation
  30
  31 # ______________________________________________________________________
  32 # generic owner. 'default' is the general config owner after init time
  33 default_owner = 'user'
  34 # ____________________________________________________________
  35 class Config(object):
  36     _cfgimpl_properties = ['hidden', 'disabled']
  37     _cfgimpl_mandatory = True
  38     _cfgimpl_frozen = True
  39     _cfgimpl_owner = default_owner
  40     _cfgimpl_toplevel = None
  41
  42     def __init__(self, descr, parent=None, **overrides):
  43         self._cfgimpl_descr = descr
  44         self._cfgimpl_value_owners = {}
  45         self._cfgimpl_parent = parent
  46         # `Config()` indeed takes care of the `Option()`'s values
  47         self._cfgimpl_values = {}
  48         self._cfgimpl_previous_values = {}
  49         # XXX warnings are a great idea, let's make up a better use of it
  50         self._cfgimpl_warnings = []
  51         self._cfgimpl_toplevel = self._cfgimpl_get_toplevel()
  52         # `freeze()` allows us to carry out this calculation again if necessary
  53         self._cfgimpl_frozen = self._cfgimpl_toplevel._cfgimpl_frozen
  54         self._cfgimpl_build(overrides)
  55
  56     def _validate_duplicates(self, children):
  57         duplicates = []
  58         for dup in children:
  59             if dup._name not in duplicates:
  60                 duplicates.append(dup._name)
  61             else:
  62                 raise ConflictConfigError('duplicate option name: '
  63                     '{0}'.format(dup._name))
  64
  65     def _cfgimpl_build(self, overrides):
  66         self._validate_duplicates(self._cfgimpl_descr._children)
  67         for child in self._cfgimpl_descr._children:
  68             if isinstance(child, Option):
  69                 if child.is_multi():
  70                     childdef = Multi(copy(child.getdefault()), config=self,
  71                                      child=child)
  72                     self._cfgimpl_values[child._name] = childdef
  73                     self._cfgimpl_previous_values[child._name] = list(childdef)
  74                     self._cfgimpl_value_owners[child._name] = ['default' \
  75                         for i in range(len(child.getdefault() ))]
  76                 else:
  77                     childdef = child.getdefault()
  78                     self._cfgimpl_values[child._name] = childdef
  79                     self._cfgimpl_previous_values[child._name] = childdef
  80                     self._cfgimpl_value_owners[child._name] = 'default'
  81             elif isinstance(child, OptionDescription):
  82                 self._validate_duplicates(child._children)
  83                 self._cfgimpl_values[child._name] = Config(child, parent=self)
  84         self.override(overrides)
  85
  86     def cfgimpl_update(self):
  87         "dynamically adds `Option()` or `OptionDescription()`"
  88         # Nothing is static. Everything evolve.
  89         # FIXME this is an update for new options in the schema only
  90         # see the update_child() method of the descr object
  91         for child in self._cfgimpl_descr._children:
  92             if isinstance(child, Option):
  93                 if child._name not in self._cfgimpl_values:
  94                     if child.is_multi():
  95                         self._cfgimpl_values[child._name] = Multi(
  96                                 copy(child.getdefault()), config=self, child=child)
  97                         self._cfgimpl_value_owners[child._name] = ['default' \
  98                                 for i in range(len(child.getdefault() ))]
  99                     else:
 100                         self._cfgimpl_values[child._name] = copy(child.getdefault())
 101                         self._cfgimpl_value_owners[child._name] = 'default'
 102             elif isinstance(child, OptionDescription):
 103                 if child._name not in self._cfgimpl_values:
 104                     self._cfgimpl_values[child._name] = Config(child, parent=self)
 105
 106     def override(self, overrides):
 107         for name, value in overrides.iteritems():
 108             homeconfig, name = self._cfgimpl_get_home_by_path(name)
 109             homeconfig.setoption(name, value, 'default')
 110
 111     def cfgimpl_set_owner(self, owner):
 112         self._cfgimpl_owner = owner
 113         for child in self._cfgimpl_descr._children:
 114             if isinstance(child, OptionDescription):
 115                 self._cfgimpl_values[child._name].cfgimpl_set_owner(owner)
 116     # ____________________________________________________________
 117     def _cfgimpl_has_properties(self):
 118         return bool(len(self._cfgimpl_properties))
 119
 120     def _cfgimpl_has_property(self, propname):
 121         return propname in self._cfgimpl_properties
 122
 123     def cfgimpl_enable_property(self, propname):
 124         if self._cfgimpl_parent != None:
 125             raise MethodCallError("this method root_hide() shall not be"
 126                                            "used with non-root Config() object")
 127         if propname not in self._cfgimpl_properties:
 128             self._cfgimpl_properties.append(propname)
 129
 130     def cfgimpl_disable_property(self, propname):
 131         if self._cfgimpl_parent != None:
 132             raise MethodCallError("this method root_hide() shall not be"
 133                                            "used with non-root Config() object")
 134         if self._cfgimpl_has_property(propname):
 135             self._cfgimpl_properties.remove(propname)
 136
 137     def cfgimpl_non_mandatory(self):
 138         if self._cfgimpl_parent != None:
 139             raise MethodCallError("this method root_mandatory machin() shall not be"
 140                                            "used with non-root Confit() object")
 141         rootconfig = self._cfgimpl_get_toplevel()
 142         rootconfig._cfgimpl_mandatory = False
 143
 144     # ____________________________________________________________
 145     def __setattr__(self, name, value):
 146         if name.startswith('_cfgimpl_'):
 147             self.__dict__[name] = value
 148             return
 149         if '.' in name:
 150             homeconfig, name = self._cfgimpl_get_home_by_path(name)
 151             return setattr(homeconfig, name, value)
 152         if type(getattr(self._cfgimpl_descr, name)) != SymLinkOption:
 153             self._validate(name, getattr(self._cfgimpl_descr, name))
 154         self.setoption(name, value, self._cfgimpl_owner)
 155
 156     def _validate(self, name, opt_or_descr):
 157         apply_requires(opt_or_descr, self)
 158         if not isinstance(opt_or_descr, Option) and \
 159                 not isinstance(opt_or_descr, OptionDescription):
 160             raise TypeError('Unexpected object: {0}'.format(repr(opt_or_descr)))
 161         properties = opt_or_descr.properties
 162         for proper in properties:
 163             if not self._cfgimpl_toplevel._cfgimpl_has_property(proper):
 164                 properties.remove(proper)
 165         if properties != []:
 166             raise PropertiesOptionError("trying to access"
 167                     " to an option named: {0} with properties"
 168                     " {1}".format(name, str(properties)),
 169                     properties)
 170
 171     def _is_empty(self, opt):
 172         if (not opt.is_multi() and self._cfgimpl_values[opt._name] == None) or \
 173             (opt.is_multi() and (self._cfgimpl_values[opt._name] == [] or \
 174                 None in self._cfgimpl_values[opt._name])):
 175             return True
 176         return False
 177
 178     def __getattr__(self, name):
 179         # attribute access by passing a path,
 180         # for instance getattr(self, "creole.general.family.adresse_ip_eth0")
 181         if '.' in name:
 182             homeconfig, name = self._cfgimpl_get_home_by_path(name)
 183             return getattr(homeconfig, name)
 184         opt_or_descr = getattr(self._cfgimpl_descr, name)
 185         # symlink options
 186         if type(opt_or_descr) == SymLinkOption:
 187             return getattr(self, opt_or_descr.path)
 188         if name not in self._cfgimpl_values:
 189             raise AttributeError("%s object has no attribute %s" %
 190                                  (self.__class__, name))
 191         self._validate(name, opt_or_descr)
 192         # special attributes
 193         if name.startswith('_cfgimpl_'):
 194             # if it were in __dict__ it would have been found already
 195             return self.__dict__[name]
 196             raise AttributeError("%s object has no attribute %s" %
 197                                  (self.__class__, name))
 198         if not isinstance(opt_or_descr, OptionDescription):
 199             # options with callbacks (fill or auto)
 200             if opt_or_descr.has_callback():
 201                 value = self._cfgimpl_values[name]
 202                 if (not opt_or_descr.is_frozen() or \
 203                         not opt_or_descr.is_forced_on_freeze()) and value != None:
 204                     if opt_or_descr.is_multi():
 205                         if None not in value:
 206                             return value
 207                     else:
 208                         return value
 209                 result = carry_out_calculation(name,
 210                             callback=opt_or_descr.getcallback(),
 211                             callback_params=opt_or_descr.getcallback_params(),
 212                             config=self._cfgimpl_get_toplevel())
 213                 # this result **shall not** be a list
 214                 # for example, [1, 2, 3, None] -> [1, 2, 3, result]
 215                 if isinstance(result, list):
 216                     raise ConfigError('invalid calculated value returned'
 217                         ' for option {0} : shall not be a list'.format(name))
 218                 if result != None and not opt_or_descr._validate(result):
 219                     raise ConfigError('invalid calculated value returned'
 220                         ' for option {0}'.format(name))
 221                 if opt_or_descr.is_multi():
 222                     if value == []:
 223                         _result = Multi([result], value.config, value.child)
 224                     else:
 225                         _result = Multi([], value.config, value.child)
 226                         for val in value:
 227                             if val == None:
 228                                 val = result
 229                             _result.append(val)
 230                 else:
 231                     _result = result
 232                 return _result
 233
 234             # mandatory options
 235             homeconfig = self._cfgimpl_get_toplevel()
 236             mandatory = homeconfig._cfgimpl_mandatory
 237             if opt_or_descr.is_mandatory() and mandatory:
 238                 if self._is_empty(opt_or_descr) and \
 239                         opt_or_descr.is_empty_by_default():
 240                     raise MandatoryError("option: {0} is mandatory "
 241                                           "and shall have a value".format(name))
 242             # frozen and force default
 243             if opt_or_descr.is_forced_on_freeze():
 244                 return opt_or_descr.getdefault()
 245
 246         return self._cfgimpl_values[name]
 247
 248     def __dir__(self):
 249         #from_type = dir(type(self))
 250         from_dict = list(self.__dict__)
 251         extras = list(self._cfgimpl_values)
 252         return sorted(set(extras + from_dict))
 253
 254     def unwrap_from_name(self, name):
 255         # didn't have to stoop so low: `self.get()` must be the proper method
 256         # **and it is slow**: it recursively searches into the namespaces
 257         paths = self.getpaths(allpaths=True)
 258         opts = dict([(path, self.unwrap_from_path(path)) for path in paths])
 259         all_paths = [p.split(".") for p in self.getpaths()]
 260         for pth in all_paths:
 261             if name in pth:
 262                 return opts[".".join(pth)]
 263         raise NotFoundError("name: {0} not found".format(name))
 264
 265     def unwrap_from_path(self, path):
 266         # didn't have to stoop so low, `geattr(self, path)` is much better
 267         # **fast**: finds the option directly in the appropriate namespace
 268         if '.' in path:
 269             homeconfig, path = self._cfgimpl_get_home_by_path(path)
 270             return getattr(homeconfig._cfgimpl_descr, path)
 271         return getattr(self._cfgimpl_descr, path)
 272
 273     def __delattr__(self, name):
 274         # if you use delattr you are responsible for all bad things happening
 275         if name.startswith('_cfgimpl_'):
 276             del self.__dict__[name]
 277             return
 278         self._cfgimpl_value_owners[name] = 'default'
 279         opt = getattr(self._cfgimpl_descr, name)
 280         if isinstance(opt, OptionDescription):
 281             raise AttributeError("can't option subgroup")
 282         self._cfgimpl_values[name] = getattr(opt, 'default', None)
 283
 284     def setoption(self, name, value, who=None):
 285         #who is **not necessarily** a owner, because it cannot be a list
 286         #FIXME : sortir le setoption pour les multi, ca ne devrait pas être la
 287         child = getattr(self._cfgimpl_descr, name)
 288         if who == None:
 289             if child.is_multi():
 290                 newowner = [self._cfgimpl_owner for i in range(len(value))]
 291             else:
 292                 newowner = self._cfgimpl_owner
 293         else:
 294             if type(child) != SymLinkOption:
 295                 if child.is_multi():
 296                     if type(value) != Multi:
 297                         if type(value) == list:
 298                             value = Multi(value, self, child)
 299                         else:
 300                             raise ConfigError("invalid value for option:"
 301                                        " {0} that is set to multi".format(name))
 302                     newowner = [who for i in range(len(value))]
 303                 else:
 304                     newowner = who
 305         if type(child) != SymLinkOption:
 306             if child.has_callback() and who=='default':
 307                 raise TypeError("trying to set a value to an option "
 308                     "wich has a callback: {0}".format(name))
 309             child.setoption(self, value, who)
 310             if (value is None and who != 'default' and not child.is_multi()):
 311                 child.setowner(self, 'default')
 312                 self._cfgimpl_values[name] = copy(child.getdefault())
 313             elif (value == [] and who != 'default' and child.is_multi()):
 314                 child.setowner(self, ['default' for i in range(len(child.getdefault()))])
 315                 self._cfgimpl_values[name] = Multi(copy(child.getdefault()),
 316                             config=self, child=child)
 317             else:
 318                 child.setowner(self, newowner)
 319         else:
 320             homeconfig = self._cfgimpl_get_toplevel()
 321             child.setoption(homeconfig, value, who)
 322
 323     def set(self, **kwargs):
 324         all_paths = [p.split(".") for p in self.getpaths(allpaths=True)]
 325         for key, value in kwargs.iteritems():
 326             key_p = key.split('.')
 327             candidates = [p for p in all_paths if p[-len(key_p):] == key_p]
 328             if len(candidates) == 1:
 329                 name = '.'.join(candidates[0])
 330                 homeconfig, name = self._cfgimpl_get_home_by_path(name)
 331                 try:
 332                     getattr(homeconfig, name)
 333                 except MandatoryError:
 334                     pass
 335                 except Exception, e:
 336                     raise e # HiddenOptionError or DisabledOptionError
 337                 homeconfig.setoption(name, value, self._cfgimpl_owner)
 338             elif len(candidates) > 1:
 339                 raise AmbigousOptionError(
 340                     'more than one option that ends with %s' % (key, ))
 341             else:
 342                 raise NoMatchingOptionFound(
 343                     'there is no option that matches %s'
 344                     ' or the option is hidden or disabled'% (key, ))
 345
 346     def get(self, name):
 347         paths = self.getpaths(allpaths=True)
 348         pathsvalues = []
 349         for path in paths:
 350             pathname = path.split('.')[-1]
 351             if pathname == name:
 352                 try:
 353                     value = getattr(self, path)
 354                     return value
 355                 except Exception, e:
 356                     raise e
 357         raise NotFoundError("option {0} not found in config".format(name))
 358
 359     def _cfgimpl_get_home_by_path(self, path):
 360         """returns tuple (config, name)"""
 361         path = path.split('.')
 362
 363         for step in path[:-1]:
 364             self = getattr(self, step)
 365         return self, path[-1]
 366
 367     def _cfgimpl_get_toplevel(self):
 368         while self._cfgimpl_parent is not None:
 369             self = self._cfgimpl_parent
 370         return self
 371
 372     def _cfgimpl_get_path(self):
 373         subpath = []
 374         obj = self
 375         while obj._cfgimpl_parent is not None:
 376             subpath.insert(0, obj._cfgimpl_descr._name)
 377             obj = obj._cfgimpl_parent
 378         return ".".join(subpath)
 379
 380
 381     def cfgimpl_previous_value(self, path):
 382         home, name = self._cfgimpl_get_home_by_path(path)
 383         return home._cfgimpl_previous_values[name]
 384
 385     def get_previous_value(self, name):
 386         return self._cfgimpl_previous_values[name]
 387
 388     def add_warning(self, warning):
 389         self._cfgimpl_get_toplevel()._cfgimpl_warnings.append(warning)
 390
 391     def get_warnings(self):
 392         return self._cfgimpl_get_toplevel()._cfgimpl_warnings
 393     # ____________________________________________________________
 394     # freeze and read-write statuses
 395     def cfgimpl_freeze(self):
 396         rootconfig = self._cfgimpl_get_toplevel()
 397         rootconfig._cfgimpl_frozen = True
 398         self._cfgimpl_frozen = True
 399
 400     def cfgimpl_unfreeze(self):
 401         rootconfig = self._cfgimpl_get_toplevel()
 402         rootconfig._cfgimpl_frozen = False
 403         self._cfgimpl_frozen = False
 404
 405     def is_frozen(self):
 406         # it should be the same value as self._cfgimpl_frozen...
 407         rootconfig = self._cfgimpl_get_toplevel()
 408         return rootconfig._cfgimpl_frozen
 409
 410     def is_mandatory(self):
 411         rootconfig = self._cfgimpl_get_toplevel()
 412         return rootconfig._cfgimpl_mandatory
 413
 414     def cfgimpl_read_only(self):
 415         # hung up on freeze, hidden and disabled concepts
 416         self.cfgimpl_freeze()
 417         rootconfig = self._cfgimpl_get_toplevel()
 418         rootconfig.cfgimpl_disable_property('hidden')
 419         rootconfig.cfgimpl_enable_property('disabled')
 420         rootconfig._cfgimpl_mandatory = True
 421
 422     def cfgimpl_read_write(self):
 423         # hung up on freeze, hidden and disabled concepts
 424         self.cfgimpl_unfreeze()
 425         rootconfig = self._cfgimpl_get_toplevel()
 426         rootconfig.cfgimpl_enable_property('hidden')
 427         rootconfig.cfgimpl_disable_property('disabled')
 428         rootconfig._cfgimpl_mandatory = False
 429     # ____________________________________________________________
 430     def getkey(self):
 431         return self._cfgimpl_descr.getkey(self)
 432
 433     def __hash__(self):
 434         return hash(self.getkey())
 435
 436     def __eq__(self, other):
 437         return self.getkey() == other.getkey()
 438
 439     def __ne__(self, other):
 440         return not self == other
 441
 442     def __iter__(self):
 443         # iteration only on Options (not OptionDescriptions)
 444         for child in self._cfgimpl_descr._children:
 445             if isinstance(child, Option):
 446                 try:
 447                     yield child._name, getattr(self, child._name)
 448                 except:
 449                     pass # option with properties
 450
 451     def iter_groups(self, group_type=None):
 452         "iteration on OptionDescriptions"
 453         if group_type == None:
 454             groups = group_types
 455         else:
 456             if group_type not in group_types:
 457                 raise TypeError("Unknown group_type: {0}".format(group_type))
 458             groups = [group_type]
 459         for child in self._cfgimpl_descr._children:
 460             if isinstance(child, OptionDescription):
 461                     try:
 462                         if child.get_group_type() in groups:
 463                             yield child._name, getattr(self, child._name)
 464                     except:
 465                         pass # hidden, disabled option
 466
 467     def __str__(self, indent=""):
 468         lines = []
 469         children = [(child._name, child)
 470                     for child in self._cfgimpl_descr._children]
 471         children.sort()
 472         for name, child in children:
 473             if self._cfgimpl_value_owners.get(name, None) == 'default':
 474                 continue
 475             value = getattr(self, name)
 476             if isinstance(value, Config):
 477                 substr = value.__str__(indent + "    ")
 478             else:
 479                 substr = "%s    %s = %s" % (indent, name, value)
 480             if substr:
 481                 lines.append(substr)
 482         if indent and not lines:
 483             return ''   # hide subgroups with all default values
 484         lines.insert(0, "%s[%s]" % (indent, self._cfgimpl_descr._name,))
 485         return '\n'.join(lines)
 486
 487     def getpaths(self, include_groups=False, allpaths=False, mandatory=False):
 488         """returns a list of all paths in self, recursively, taking care of
 489         the context of properties (hidden/disabled)
 490         """
 491         paths = []
 492         for path in self._cfgimpl_descr.getpaths(include_groups=include_groups):
 493             try:
 494                 value = getattr(self, path)
 495
 496             except MandatoryError:
 497                 if mandatory or allpaths:
 498                     paths.append(path)
 499             except PropertiesOptionError:
 500                 if allpaths:
 501                     paths.append(path) # hidden or disabled or mandatory option added
 502             else:
 503                  paths.append(path)
 504         return paths
 505
 506 def make_dict(config, flatten=False):
 507     paths = config.getpaths()
 508     pathsvalues = []
 509     for path in paths:
 510         if flatten:
 511             pathname = path.split('.')[-1]
 512         else:
 513             pathname = path
 514         try:
 515             value = getattr(config, path)
 516             pathsvalues.append((pathname, value))
 517         except:
 518             pass # this just a hidden or disabled option
 519     options = dict(pathsvalues)
 520     return options
 521
 522 def mandatory_warnings(config):
 523     mandatory = config._cfgimpl_get_toplevel()._cfgimpl_mandatory
 524     config._cfgimpl_get_toplevel()._cfgimpl_mandatory = True
 525     for path in config._cfgimpl_descr.getpaths(include_groups=True):
 526         try:
 527             value = getattr(config, path)
 528         except MandatoryError:
 529             yield path
 530         except PropertiesOptionError:
 531             pass
 532     config._cfgimpl_get_toplevel()._cfgimpl_mandatory = mandatory