1 # Copyright (C) 2010 W. Trevor King <wking@drexel.edu>
3 # This file is part of Hooke.
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.
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.
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/>.
19 """The `playlist` module provides a :class:`Playlist` and its subclass
20 :class:`FilePlaylist` for manipulating lists of
21 :class:`hooke.curve.Curve`\s.
28 import xml.dom.minidom
30 from . import curve as curve
31 from .compat import minidom as minidom # dynamically patch xml.sax.minidom
34 class NoteIndexList (list):
35 """A list that keeps track of a "current" item and additional notes.
37 :attr:`index` (i.e. "bookmark") is the index of the currently
38 current curve. Also keep a :class:`dict` of additional information
41 def __init__(self, name=None):
42 super(NoteIndexList, self).__init__()
48 return str(self.__unicode__())
50 def __unicode__(self):
51 return u'<%s %s>' % (self.__class__.__name__, self.name)
56 def _setup_item(self, item):
57 """Perform any required initialization before returning an item.
61 def index(self, value=None, *args, **kwargs):
62 """Extend `list.index`, returning the current index if `value`
67 return super(NoteIndexList, self).index(value, *args, **kwargs)
72 item = self[self._index]
73 self._setup_item(item)
76 def jump(self, index):
80 self._index = index % len(self)
83 self.jump(self._index + 1)
86 self.jump(self._index - 1)
88 def items(self, reverse=False):
89 """Iterate through `self` calling `_setup_item` on each item
94 items = reversed(self)
96 self._setup_item(item)
99 def filter(self, keeper_fn=lambda item:True, *args, **kwargs):
100 c = copy.deepcopy(self)
101 for item in c.items(reverse=True):
102 if keeper_fn(item, *args, **kwargs) != True:
104 try: # attempt to maintain the same current item
105 c._index = c.index(self.current())
111 class Playlist (NoteIndexList):
112 """A :class:`NoteIndexList` of :class:`hooke.curve.Curve`\s.
114 Keeps a list of :attr:`drivers` for loading curves.
116 def __init__(self, drivers, name=None):
117 super(Playlist, self).__init__(name=name)
118 self.drivers = drivers
119 self._loaded = [] # List of loaded curves, see :meth:`._setup_item`.
120 self._max_loaded = 100 # curves to hold in memory simultaneously.
122 def append_curve_by_path(self, path, info=None, identify=True, hooke=None):
123 path = os.path.normpath(path)
124 c = curve.Curve(path, info=info)
127 c.identify(self.drivers)
131 def _setup_item(self, curve):
132 if curve != None and curve not in self._loaded:
133 if curve not in self:
135 if curve.driver == None:
136 c.identify(self.drivers)
137 if curve.data == None:
139 self._loaded.append(curve)
140 if len(self._loaded) > self._max_loaded:
141 oldest = self._loaded.pop(0)
145 class FilePlaylist (Playlist):
148 def __init__(self, drivers, name=None, path=None):
149 super(FilePlaylist, self).__init__(drivers, name)
153 self._ignored_keys = [
154 'experiment', # class instance, not very exciting.
157 def set_path(self, path):
159 if not path.endswith('.hkp'):
162 if self.name == None:
163 self.name = os.path.basename(path)
165 def append_curve_by_path(self, path, *args, **kwargs):
166 if self.path != None:
167 path = os.path.join(os.path.dirname(self.path), path)
168 super(FilePlaylist, self).append_curve_by_path(path, *args, **kwargs)
171 return self.digest() == self._digest
174 r"""Compute the sha1 digest of the flattened playlist
180 >>> root_path = os.path.sep + 'path'
181 >>> p = FilePlaylist(drivers=[],
182 ... path=os.path.join(root_path, 'to','playlist'))
183 >>> p.info['note'] = 'An example playlist'
184 >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'one'))
185 >>> c.info['note'] = 'The first curve'
187 >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'two'))
188 >>> c.info['note'] = 'The second curve'
191 '\\\x14\x87\x88*q\xf8\xaa\xa7\x84f\x82\xa1S>\xfd3+\xd0o'
193 string = self.flatten()
194 return hashlib.sha1(string).digest()
196 def _clean_key(self, key):
197 """Replace spaces in keys with \\u00B7 (middle dot).
199 This character is deemed unlikely to occur in keys to our
200 playlist and curve info dictionaries, while many keys have
203 \\u00B7 is allowed in XML 1.0 as of the 5th edition. See
204 the `4th edition errata`_ for details.
206 .. _4th edition errata:
207 http://www.w3.org/XML/xml-V10-4e-errata#E09
209 return key.replace(' ', u'\u00B7')
211 def _restore_key(self, key):
212 """Restore keys encoded with :meth:`_clean_key`.
214 return key.replace(u'\u00B7', ' ')
216 def flatten(self, absolute_paths=False):
217 """Create a string representation of the playlist.
219 A playlist is an XML document with the following syntax::
221 <?xml version="1.0" encoding="utf-8"?>
222 <playlist attribute="value">
223 <curve path="/my/file/path/"/ attribute="value" ...>
227 Relative paths are interpreted relative to the location of the
233 >>> root_path = os.path.sep + 'path'
234 >>> p = FilePlaylist(drivers=[],
235 ... path=os.path.join(root_path, 'to','playlist'))
236 >>> p.info['note'] = 'An example playlist'
237 >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'one'))
238 >>> c.info['note'] = 'The first curve'
240 >>> c = curve.Curve(os.path.join(root_path, 'to', 'curve', 'two'))
241 >>> c.info['attr with spaces'] = 'The second curve\\nwith endlines'
243 >>> def _print(string):
244 ... escaped_string = unicode(string, 'utf-8').encode('unicode escape')
245 ... print escaped_string.replace('\\\\n', '\\n').replace('\\\\t', '\\t'),
246 >>> _print(p.flatten()) # doctest: +NORMALIZE_WHITESPACE +REPORT_UDIFF
247 <?xml version="1.0" encoding="utf-8"?>
248 <playlist index="0" note="An example playlist" version="0.1">
249 <curve note="The first curve" path="curve/one"/>
250 <curve attr\\xb7with\\xb7spaces="The second curve
with endlines" path="curve/two"/>
252 >>> _print(p.flatten(absolute_paths=True)) # doctest: +NORMALIZE_WHITESPACE +REPORT_UDIFF
253 <?xml version="1.0" encoding="utf-8"?>
254 <playlist index="0" note="An example playlist" version="0.1">
255 <curve note="The first curve" path="/path/to/curve/one"/>
256 <curve attr\\xb7with\\xb7spaces="The second curve
with endlines" path="/path/to/curve/two"/>
259 implementation = xml.dom.minidom.getDOMImplementation()
260 # create the document DOM object and the root element
261 doc = implementation.createDocument(None, 'playlist', None)
262 root = doc.documentElement
263 root.setAttribute('version', self.version) # store playlist version
264 root.setAttribute('index', str(self._index))
265 for key,value in self.info.items(): # save info variables
266 if (key in self._ignored_keys
267 or not isinstance(value, types.StringTypes)):
269 root.setAttribute(self._clean_key(key), str(value))
270 for curve in self: # save curves and their attributes
271 curve_element = doc.createElement('curve')
272 root.appendChild(curve_element)
273 path = os.path.abspath(os.path.expanduser(curve.path))
274 if absolute_paths == False:
275 path = os.path.relpath(
279 os.path.expanduser(self.path))))
280 curve_element.setAttribute('path', path)
281 for key,value in curve.info.items():
282 if (key in self._ignored_keys
283 or not isinstance(value, types.StringTypes)):
285 curve_element.setAttribute(self._clean_key(key), str(value))
286 string = doc.toprettyxml(encoding='utf-8')
287 root.unlink() # break circular references for garbage collection
290 def _from_xml_doc(self, doc, identify=True):
291 """Load a playlist from an :class:`xml.dom.minidom.Document`
294 root = doc.documentElement
295 for attribute,value in root.attributes.items():
296 attribute = self._restore_key(attribute)
297 if attribute == 'version':
298 assert value == self.version, \
299 'Cannot read v%s playlist with a v%s reader' \
300 % (value, self.version)
301 elif attribute == 'index':
302 self._index = int(value)
304 self.info[attribute] = value
305 for curve_element in doc.getElementsByTagName('curve'):
306 path = curve_element.getAttribute('path')
307 info = dict([(self._restore_key(key), value)
308 for key,value in curve_element.attributes.items()])
310 self.append_curve_by_path(path, info, identify=identify)
311 self.jump(self._index) # ensure valid index
313 def from_string(self, string, identify=True):
314 u"""Load a playlist from a string.
319 >>> string = '''<?xml version="1.0" encoding="utf-8"?>
320 ... <playlist index="1" note="An example playlist" version="0.1">
321 ... <curve note="The first curve" path="../curve/one"/>
322 ... <curve attr\xb7with\xb7spaces="The second curve
with endlines" path="../curve/two"/>
325 >>> p = FilePlaylist(drivers=[],
326 ... path=os.path.join('path', 'to', 'my', 'playlist'))
327 >>> p.from_string(string, identify=False)
331 {u'note': u'An example playlist'}
336 >>> p[-1].info['attr with spaces']
337 u'The second curve\\nwith endlines'
339 doc = xml.dom.minidom.parseString(string)
340 self._from_xml_doc(doc, identify=identify)
342 def load(self, path=None, identify=True, hooke=None):
343 """Load a playlist from a file.
346 doc = xml.dom.minidom.parse(self.path)
347 self._from_xml_doc(doc, identify=identify)
348 self._digest = self.digest()
350 curve.set_hooke(hooke)
352 def save(self, path=None):
353 """Saves the playlist in a XML file.
356 with open(self.path, 'w') as f:
357 f.write(self.flatten())
358 self._digest = self.digest()