hooke/playlist.py

   1 # Copyright (C) 2010 W. Trevor King <wking@drexel.edu>
   2 #
   3 # This file is part of Hooke.
   4 #
   5 # Hooke is free software: you can redistribute it and/or modify it
   6 # under the terms of the GNU Lesser General Public License as
   7 # published by the Free Software Foundation, either version 3 of the
   8 # License, or (at your option) any later version.
   9 #
  10 # Hooke is distributed in the hope that it will be useful, but WITHOUT
  11 # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  12 # or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General
  13 # Public License for more details.
  14 #
  15 # You should have received a copy of the GNU Lesser General Public
  16 # License along with Hooke.  If not, see
  17 # <http://www.gnu.org/licenses/>.
  18
  19 """The `playlist` module provides a :class:`Playlist` and its subclass
  20 :class:`FilePlaylist` for manipulating lists of
  21 :class:`hooke.curve.Curve`\s.
  22 """
  23
  24 import copy
  25 import hashlib
  26 import os
  27 import os.path
  28 import types
  29
  30 import yaml
  31 from yaml.representer import RepresenterError
  32
  33 from . import curve as curve
  34 from .util.itertools import reverse_enumerate
  35
  36
  37 class NoteIndexList (list):
  38     """A list that keeps track of a "current" item and additional notes.
  39
  40     :attr:`index` (i.e. "bookmark") is the index of the currently
  41     current curve.  Also keep a :class:`dict` of additional information
  42     (:attr:`info`).
  43     """
  44     def __init__(self, name=None):
  45         super(NoteIndexList, self).__init__()
  46         self.name = name
  47         self.info = {}
  48         self._index = 0
  49         self._set_ignored_attrs()
  50
  51     def __str__(self):
  52         return str(self.__unicode__())
  53
  54     def __unicode__(self):
  55         return u'<%s %s>' % (self.__class__.__name__, self.name)
  56
  57     def __repr__(self):
  58         return self.__str__()
  59
  60     def _set_ignored_attrs(self):
  61         self._ignored_attrs = ['_ignored_attrs', '_default_attrs']
  62         self._default_attrs = {
  63             'info': {},
  64             }
  65
  66     def __getstate__(self):
  67         state = dict(self.__dict__)
  68         for key in self._ignored_attrs:
  69             if key in state:
  70                 del(state[key])
  71         for key,value in self._default_attrs.items():
  72             if key in state and state[key] == value:
  73                 del(state[key])
  74         assert 'items' not in state
  75         state['items'] = []
  76         self._assert_clean_state(self, state)
  77         for item in self:  # save curves and their attributes
  78             item_state = self._item_getstate(item)
  79             self._assert_clean_state(item, item_state)
  80             state['items'].append(item_state)
  81         return state
  82
  83     def __setstate__(self, state):
  84         self._set_ignored_attrs()
  85         for key,value in self._default_attrs.items():
  86             setattr(self, key, value)
  87         for key,value in state.items():
  88             if key == 'items':
  89                 continue
  90             setattr(self, key, value)
  91         for item_state in state['items']:
  92             self.append(self._item_setstate(item_state))
  93
  94     def _item_getstate(self, item):
  95         return item
  96
  97     def _item_setstate(self, state):
  98         return state
  99
 100     def _assert_clean_state(self, owner, state):
 101         return
 102         for k,v in state.items():
 103             try:
 104                 yaml.safe_dump((k,v))
 105             except RepresenterError, e:
 106                 raise NotImplementedError(
 107                     'cannot convert %s.%s = %s (%s) to safe YAML'
 108                     % (owner.__class__.__name__, k, v, type(v)))
 109
 110     def _setup_item(self, item):
 111         """Perform any required initialization before returning an item.
 112         """
 113         pass
 114
 115     def index(self, value=None, *args, **kwargs):
 116         """Extend `list.index`, returning the current index if `value`
 117         is `None`.
 118         """
 119         if value == None:
 120             return self._index
 121         return super(NoteIndexList, self).index(value, *args, **kwargs)
 122
 123     def current(self):
 124         if len(self) == 0:
 125             return None
 126         item = self[self._index]
 127         self._setup_item(item)
 128         return item
 129
 130     def jump(self, index):
 131         if len(self) == 0:
 132             self._index = 0
 133         else:
 134             self._index = index % len(self)
 135
 136     def next(self):
 137         self.jump(self._index + 1)
 138
 139     def previous(self):
 140         self.jump(self._index - 1)
 141
 142     def items(self, reverse=False):
 143         """Iterate through `self` calling `_setup_item` on each item
 144         before yielding.
 145
 146         Notes
 147         -----
 148         Updates :attr:`_index` during the iteration so
 149         :func:`~hooke.plugin.curve.current_curve_callback` works as
 150         expected in :class:`~hooke.command.Command`\s called from
 151         :class:`~hooke.plugin.playlist.ApplyCommand`.  After the
 152         iteration completes, :attr:`_index` is restored to its
 153         original value.
 154         """
 155         index = self._index
 156         items = self
 157         if reverse == True:
 158             items = reverse_enumerate(self)
 159         else:
 160             items = enumerate(self)
 161         for i,item in items:
 162             self._index = i
 163             self._setup_item(item)
 164             yield item
 165         self._index = index
 166
 167     def filter(self, keeper_fn=lambda item:True, load_curves=True,
 168                *args, **kwargs):
 169         c = copy.deepcopy(self)
 170         if load_curves == True:
 171             items = c.items(reverse=True)
 172         else:
 173             items = reversed(c)
 174         for item in items:
 175             if keeper_fn(item, *args, **kwargs) != True:
 176                 c.remove(item)
 177         try: # attempt to maintain the same current item
 178             c._index = c.index(self.current())
 179         except ValueError:
 180             c._index = 0
 181         return c
 182
 183
 184 class Playlist (NoteIndexList):
 185     """A :class:`NoteIndexList` of :class:`hooke.curve.Curve`\s.
 186
 187     Keeps a list of :attr:`drivers` for loading curves.
 188     """
 189     def __init__(self, drivers, name=None):
 190         super(Playlist, self).__init__(name=name)
 191         self.drivers = drivers
 192         self._max_loaded = 100 # curves to hold in memory simultaneously.
 193
 194     def _set_ignored_attrs(self):
 195         super(Playlist, self)._set_ignored_attrs()
 196         self._ignored_attrs.extend([
 197                 '_item_ignored_attrs', '_item_default_attrs',
 198                 '_loaded'])
 199         self._item_ignored_attrs = []
 200         self._item_default_attrs = {
 201             'command_stack': [],
 202             'data': None,
 203             'driver': None,
 204             'info': {},
 205             'name': None,
 206             }
 207         self._loaded = [] # List of loaded curves, see :meth:`._setup_item`.
 208
 209     def _item_getstate(self, item):
 210         assert isinstance(item, curve.Curve), type(item)
 211         state = item.__getstate__()
 212         for key in self._item_ignored_attrs:
 213             if key in state:
 214                 del(state[key])
 215         for key,value in self._item_default_attrs.items():
 216             if key in state and state[key] == value:
 217                 del(state[key])
 218         return state
 219
 220     def _item_setstate(self, state):
 221         for key,value in self._item_default_attrs.items():
 222             if key not in state:
 223                 state[key] = value
 224         item = curve.Curve(path=None)
 225         item.__setstate__(state)
 226         return item
 227
 228     def append_curve_by_path(self, path, info=None, identify=True, hooke=None):
 229         path = os.path.normpath(path)
 230         c = curve.Curve(path, info=info)
 231         c.set_hooke(hooke)
 232         if identify == True:
 233             c.identify(self.drivers)
 234         self.append(c)
 235         return c
 236
 237     def _setup_item(self, curve):
 238         if curve != None and curve not in self._loaded:
 239             if curve not in self:
 240                 self.append(curve)
 241             if curve.driver == None:
 242                 c.identify(self.drivers)
 243             if curve.data == None:
 244                 curve.load()
 245             self._loaded.append(curve)
 246             if len(self._loaded) > self._max_loaded:
 247                 oldest = self._loaded.pop(0)
 248                 oldest.unload()
 249
 250
 251 class FilePlaylist (Playlist):
 252     """A file-backed :class:`Playlist`.
 253     """
 254     version = '0.2'
 255
 256     def __init__(self, drivers, name=None, path=None):
 257         super(FilePlaylist, self).__init__(drivers, name)
 258         self.path = self._base_path = None
 259         self.set_path(path)
 260         self._relative_curve_paths = True
 261
 262     def _set_ignored_attrs(self):
 263         super(FilePlaylist, self)._set_ignored_attrs()
 264         self._ignored_attrs.append('_digest')
 265         self._digest = None
 266
 267     def __getstate__(self):
 268         state = super(FilePlaylist, self).__getstate__()
 269         assert 'version' not in state, state
 270         state['version'] = self.version
 271         return state
 272
 273     def __setstate__(self, state):
 274         assert('version') in state, state
 275         version = state.pop('version')
 276         assert version == FilePlaylist.version, (
 277             'invalid version %s (%s) != %s (%s)'
 278             % (version, type(version),
 279                FilePlaylist.version, type(FilePlaylist.version)))
 280         super(FilePlaylist, self).__setstate__(state)
 281
 282     def _item_getstate(self, item):
 283         state = super(FilePlaylist, self)._item_getstate(item)
 284         if state.get('path', None) != None:
 285             path = os.path.abspath(os.path.expanduser(state['path']))
 286             if self._relative_curve_paths == True:
 287                 path = os.path.relpath(path, self._base_path)
 288             state['path'] = path
 289         return state
 290
 291     def _item_setstate(self, state):
 292         item = super(FilePlaylist, self)._item_setstate(state)
 293         if 'path' in state:
 294             item.set_path(os.path.join(self._base_path, state['path']))
 295         return item
 296
 297     def set_path(self, path):
 298         if path == None:
 299             if self._base_path == None:
 300                 self._base_path = os.getcwd()
 301         else:
 302             if not path.endswith('.hkp'):
 303                 path += '.hkp'
 304             self.path = path
 305             self._base_path = os.path.dirname(os.path.abspath(
 306                 os.path.expanduser(self.path)))
 307             if self.name == None:
 308                 self.name = os.path.basename(path)
 309
 310     def append_curve_by_path(self, path, *args, **kwargs):
 311         if self._base_path != None:
 312             path = os.path.join(self._base_path, path)
 313         super(FilePlaylist, self).append_curve_by_path(path, *args, **kwargs)
 314
 315     def is_saved(self):
 316         return self.digest() == self._digest
 317
 318     def digest(self):
 319         r"""Compute the sha1 digest of the flattened playlist
 320         representation.
 321
 322         Examples
 323         --------
 324
 325         >>> root_path = os.path.sep + 'path'
 326         >>> p = FilePlaylist(drivers=[],
 327         ...                  path=os.path.join(root_path, 'to','playlist'))
 328         >>> p.info['note'] = 'An example playlist'
 329         >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'one'))
 330         >>> c.info['note'] = 'The first curve'
 331         >>> p.append(c)
 332         >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'two'))
 333         >>> c.info['note'] = 'The second curve'
 334         >>> p.append(c)
 335         >>> p.digest()
 336         '\xa1\x1ax\xb1|\x84uA\xe4\x1d\xbf`\x004|\x82\xc2\xdd\xc1\x9e'
 337         """
 338         string = self.flatten()
 339         return hashlib.sha1(string).digest()
 340
 341     def flatten(self):
 342         """Create a string representation of the playlist.
 343
 344         A playlist is a YAML document with the following minimal syntax::
 345
 346             version: '0.2'
 347             items:
 348             - path: picoforce.000
 349             - path: picoforce.001
 350
 351         Relative paths are interpreted relative to the location of the
 352         playlist file.
 353
 354         Examples
 355         --------
 356
 357         >>> from .engine import CommandMessage
 358
 359         >>> root_path = os.path.sep + 'path'
 360         >>> p = FilePlaylist(drivers=[],
 361         ...                  path=os.path.join(root_path, 'to','playlist'))
 362         >>> p.info['note'] = 'An example playlist'
 363         >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'one'))
 364         >>> c.info['note'] = 'The first curve'
 365         >>> p.append(c)
 366         >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'two'))
 367         >>> c.info['attr with spaces'] = 'The second curve\\nwith endlines'
 368         >>> c.command_stack.extend([
 369         ...         CommandMessage('command A', {'arg 0':0, 'arg 1':'X'}),
 370         ...         CommandMessage('command B', {'arg 0':1, 'arg 1':'Y'}),
 371         ...         ])
 372         >>> p.append(c)
 373         >>> print p.flatten()  # doctest: +REPORT_UDIFF
 374         # Hooke playlist version 0.2
 375         _base_path: /path/to
 376         _index: 0
 377         _max_loaded: 100
 378         _relative_curve_paths: true
 379         drivers: []
 380         info: {note: An example playlist}
 381         items:
 382         - info: {note: The first curve}
 383           name: one
 384           path: curve/one
 385         - command_stack:
 386           - arguments: {arg 0: 0, arg 1: X}
 387             command: command A
 388           - arguments: {arg 0: 1, arg 1: Y}
 389             command: command B
 390           info: {attr with spaces: 'The second curve
 391         <BLANKLINE>
 392               with endlines'}
 393           name: two
 394           path: curve/two
 395         name: playlist.hkp
 396         path: /path/to/playlist.hkp
 397         version: '0.2'
 398         <BLANKLINE>
 399         >>> p._relative_curve_paths = False
 400         >>> print p.flatten()  # doctest: +REPORT_UDIFF
 401         # Hooke playlist version 0.2
 402         _base_path: /path/to
 403         _index: 0
 404         _max_loaded: 100
 405         _relative_curve_paths: false
 406         drivers: []
 407         info: {note: An example playlist}
 408         items:
 409         - info: {note: The first curve}
 410           name: one
 411           path: /path/to/curve/one
 412         - command_stack:
 413           - arguments: {arg 0: 0, arg 1: X}
 414             command: command A
 415           - arguments: {arg 0: 1, arg 1: Y}
 416             command: command B
 417           info: {attr with spaces: 'The second curve
 418         <BLANKLINE>
 419               with endlines'}
 420           name: two
 421           path: /path/to/curve/two
 422         name: playlist.hkp
 423         path: /path/to/playlist.hkp
 424         version: '0.2'
 425         <BLANKLINE>
 426         """
 427         yaml_string = yaml.dump(self.__getstate__(), allow_unicode=True)
 428         return ('# Hooke playlist version %s\n' % self.version) + yaml_string
 429
 430     def from_string(self, string):
 431         u"""Load a playlist from a string.
 432
 433         Examples
 434         --------
 435
 436         Minimal example.
 437
 438         >>> string = '''# Hooke playlist version 0.2
 439         ... version: '0.2'
 440         ... items:
 441         ... - path: picoforce.000
 442         ... - path: picoforce.001
 443         ... '''
 444         >>> p = FilePlaylist(drivers=[],
 445         ...                 path=os.path.join('/path', 'to', 'my', 'playlist'))
 446         >>> p.from_string(string)
 447         >>> for curve in p:
 448         ...     print curve.path
 449         /path/to/my/picoforce.000
 450         /path/to/my/picoforce.001
 451
 452         More complicated example.
 453
 454         >>> string = '''# Hooke playlist version 0.2
 455         ... _base_path: /path/to
 456         ... _digest: null
 457         ... _index: 1
 458         ... _max_loaded: 100
 459         ... _relative_curve_paths: true
 460         ... info: {note: An example playlist}
 461         ... items:
 462         ... - info: {note: The first curve}
 463         ...   path: curve/one
 464         ... - command_stack:
 465         ...   - arguments: {arg 0: 0, arg 1: X}
 466         ...     command: command A
 467         ...   - arguments: {arg 0: 1, arg 1: Y}
 468         ...     command: command B
 469         ...   info: {attr with spaces: 'The second curve
 470         ...
 471         ...       with endlines'}
 472         ...   name: two
 473         ...   path: curve/two
 474         ... name: playlist.hkp
 475         ... path: /path/to/playlist.hkp
 476         ... version: '0.2'
 477         ... '''
 478         >>> p = FilePlaylist(drivers=[],
 479         ...                  path=os.path.join('path', 'to', 'my', 'playlist'))
 480         >>> p.from_string(string)
 481         >>> p._index
 482         1
 483         >>> p.info
 484         {'note': 'An example playlist'}
 485         >>> for curve in p:
 486         ...     print curve.name, curve.path
 487         one /path/to/curve/one
 488         two /path/to/curve/two
 489         >>> p[-1].info['attr with spaces']
 490         'The second curve\\nwith endlines'
 491         >>> type(p[-1].command_stack)
 492         <class 'hooke.command_stack.CommandStack'>
 493         >>> p[-1].command_stack  # doctest: +NORMALIZE_WHITESPACE
 494         [<CommandMessage command A {arg 0: 0, arg 1: X}>,
 495          <CommandMessage command B {arg 0: 1, arg 1: Y}>]
 496         """
 497         state = yaml.load(string)
 498         self.__setstate__(state)
 499
 500     def save(self, path=None, makedirs=True):
 501         """Saves the playlist to a YAML file.
 502         """
 503         self.set_path(path)
 504         dirname = os.path.dirname(self.path) or '.'
 505         if makedirs == True and not os.path.isdir(dirname):
 506             os.makedirs(dirname)
 507         with open(self.path, 'w') as f:
 508             f.write(self.flatten())
 509             self._digest = self.digest()
 510
 511     def load(self, path=None, identify=True, hooke=None):
 512         """Load a playlist from a file.
 513         """
 514         self.set_path(path)
 515         with open(self.path, 'r') as f:
 516             text = f.read()
 517         self.from_string(text)
 518         self._digest = self.digest()
 519         for curve in self:
 520             curve.set_hooke(hooke)
 521             if identify == True:
 522                 curve.identify(self.drivers)