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