diff options
| -rw-r--r-- | youtube_dl/jsinterp.py | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/youtube_dl/jsinterp.py b/youtube_dl/jsinterp.py index bb406647a..f837865c4 100644 --- a/youtube_dl/jsinterp.py +++ b/youtube_dl/jsinterp.py @@ -502,8 +502,15 @@ class JSInterpreter(object): expr = self._dump(inner, local_vars) + outer if expr.startswith('('): - inner, outer = self._separate_at_paren(expr) - inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion) + + m = re.match(r'\((?P<d>[a-z])%(?P<e>[a-z])\.length\+(?P=e)\.length\)%(?P=e)\.length', expr) + if m: + # short-cut eval of frequently used `(d%e.length+e.length)%e.length`, worth ~6% on `pytest -k test_nsig` + outer = None + inner, should_abort = self._offset_e_by_d(m.group('d'), m.group('e'), local_vars) + else: + inner, outer = self._separate_at_paren(expr) + inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion) if not outer or should_abort: return inner, should_abort or should_return else: @@ -957,6 +964,17 @@ class JSInterpreter(object): return obj + @staticmethod + def _offset_e_by_d(d, e, local_vars): + """ Short-cut eval: (d%e.length+e.length)%e.length """ + try: + d = local_vars[d] + e = local_vars[e] + e = len(e) + return _js_mod(_js_mod(d, e) + e, e), False + except Exception: + return None, True + def extract_function_code(self, funcname): """ @returns argnames, code """ func_m = re.search( |