_ Git - youtube-dl/blob - devscripts/make_lazy_extractors.py

   1 from __future__ import unicode_literals, print_function
   2
   3 from inspect import getsource
   4 import os
   5 from os.path import dirname as dirn
   6 import sys
   7
   8 print('WARNING: Lazy loading extractors is an experimental feature that may not always work', file=sys.stderr)
   9
  10 sys.path.insert(0, dirn(dirn((os.path.abspath(__file__)))))
  11
  12 lazy_extractors_filename = sys.argv[1]
  13 if os.path.exists(lazy_extractors_filename):
  14     os.remove(lazy_extractors_filename)
  15
  16 from youtube_dl.extractor import _ALL_CLASSES
  17 from youtube_dl.extractor.common import InfoExtractor, SearchInfoExtractor
  18
  19 with open('devscripts/lazy_load_template.py', 'rt') as f:
  20     module_template = f.read()
  21
  22 module_contents = [
  23     module_template + '\n' + getsource(InfoExtractor.suitable) + '\n',
  24     'class LazyLoadSearchExtractor(LazyLoadExtractor):\n    pass\n']
  25
  26 ie_template = '''
  27 class {name}({bases}):
  28     _VALID_URL = {valid_url!r}
  29     _module = '{module}'
  30 '''
  31
  32 make_valid_template = '''
  33     @classmethod
  34     def _make_valid_url(cls):
  35         return {valid_url!r}
  36 '''
  37
  38
  39 def get_base_name(base):
  40     if base is InfoExtractor:
  41         return 'LazyLoadExtractor'
  42     elif base is SearchInfoExtractor:
  43         return 'LazyLoadSearchExtractor'
  44     else:
  45         return base.__name__
  46
  47
  48 def build_lazy_ie(ie, name):
  49     valid_url = getattr(ie, '_VALID_URL', None)
  50     s = ie_template.format(
  51         name=name,
  52         bases=', '.join(map(get_base_name, ie.__bases__)),
  53         valid_url=valid_url,
  54         module=ie.__module__)
  55     if ie.suitable.__func__ is not InfoExtractor.suitable.__func__:
  56         s += '\n' + getsource(ie.suitable)
  57     if hasattr(ie, '_make_valid_url'):
  58         # search extractors
  59         s += make_valid_template.format(valid_url=ie._make_valid_url())
  60     return s
  61
  62 # find the correct sorting and add the required base classes so that sublcasses
  63 # can be correctly created
  64 classes = _ALL_CLASSES[:-1]
  65 ordered_cls = []
  66 while classes:
  67     for c in classes[:]:
  68         bases = set(c.__bases__) - set((object, InfoExtractor, SearchInfoExtractor))
  69         stop = False
  70         for b in bases:
  71             if b not in classes and b not in ordered_cls:
  72                 if b.__name__ == 'GenericIE':
  73                     exit()
  74                 classes.insert(0, b)
  75                 stop = True
  76         if stop:
  77             break
  78         if all(b in ordered_cls for b in bases):
  79             ordered_cls.append(c)
  80             classes.remove(c)
  81             break
  82 ordered_cls.append(_ALL_CLASSES[-1])
  83
  84 names = []
  85 for ie in ordered_cls:
  86     name = ie.__name__
  87     src = build_lazy_ie(ie, name)
  88     module_contents.append(src)
  89     if ie in _ALL_CLASSES:
  90         names.append(name)
  91
  92 module_contents.append(
  93     '_ALL_CLASSES = [{0}]'.format(', '.join(names)))
  94
  95 module_src = '\n'.join(module_contents) + '\n'
  96
  97 with open(lazy_extractors_filename, 'wt') as f:
  98     f.write(module_src)