diff options
Diffstat (limited to 'youtube_dl/jsinterp.py')
| -rw-r--r-- | youtube_dl/jsinterp.py | 85 |
1 files changed, 68 insertions, 17 deletions
diff --git a/youtube_dl/jsinterp.py b/youtube_dl/jsinterp.py index 86d902248..02adf6678 100644 --- a/youtube_dl/jsinterp.py +++ b/youtube_dl/jsinterp.py @@ -14,6 +14,7 @@ from .utils import ( remove_quotes, unified_timestamp, variadic, + write_string, ) from .compat import ( compat_basestring, @@ -53,15 +54,16 @@ def wraps_op(op): # NB In principle NaN cannot be checked by membership. # Here all NaN values are actually this one, so _NaN is _NaN, -# although _NaN != _NaN. +# although _NaN != _NaN. Ditto Infinity. _NaN = float('nan') +_Infinity = float('inf') def _js_bit_op(op): def zeroise(x): - return 0 if x in (None, JS_Undefined, _NaN) else x + return 0 if x in (None, JS_Undefined, _NaN, _Infinity) else x @wraps_op(op) def wrapped(a, b): @@ -84,7 +86,7 @@ def _js_arith_op(op): def _js_div(a, b): if JS_Undefined in (a, b) or not (a or b): return _NaN - return operator.truediv(a or 0, b) if b else float('inf') + return operator.truediv(a or 0, b) if b else _Infinity def _js_mod(a, b): @@ -220,6 +222,42 @@ class LocalNameSpace(ChainMap): return 'LocalNameSpace%s' % (self.maps, ) +class Debugger(object): + ENABLED = False + + @staticmethod + def write(*args, **kwargs): + level = kwargs.get('level', 100) + + def truncate_string(s, left, right=0): + if s is None or len(s) <= left + right: + return s + return '...'.join((s[:left - 3], s[-right:] if right else '')) + + write_string('[debug] JS: {0}{1}\n'.format( + ' ' * (100 - level), + ' '.join(truncate_string(compat_str(x), 50, 50) for x in args))) + + @classmethod + def wrap_interpreter(cls, f): + def interpret_statement(self, stmt, local_vars, allow_recursion, *args, **kwargs): + if cls.ENABLED and stmt.strip(): + cls.write(stmt, level=allow_recursion) + try: + ret, should_ret = f(self, stmt, local_vars, allow_recursion, *args, **kwargs) + except Exception as e: + if cls.ENABLED: + if isinstance(e, ExtractorError): + e = e.orig_msg + cls.write('=> Raises:', e, '<-|', stmt, level=allow_recursion) + raise + if cls.ENABLED and stmt.strip(): + if should_ret or not repr(ret) == stmt: + cls.write(['->', '=>'][should_ret], repr(ret), '<-|', stmt, level=allow_recursion) + return ret, should_ret + return interpret_statement + + class JSInterpreter(object): __named_object_counter = 0 @@ -307,8 +345,7 @@ class JSInterpreter(object): def __op_chars(cls): op_chars = set(';,[') for op in cls._all_operators(): - for c in op[0]: - op_chars.add(c) + op_chars.update(op[0]) return op_chars def _named_object(self, namespace, obj): @@ -326,9 +363,8 @@ class JSInterpreter(object): # collections.Counter() is ~10% slower in both 2.7 and 3.9 counters = dict((k, 0) for k in _MATCHING_PARENS.values()) start, splits, pos, delim_len = 0, 0, 0, len(delim) - 1 - in_quote, escaping, skipping = None, False, 0 - after_op, in_regex_char_group = True, False - + in_quote, escaping, after_op, in_regex_char_group = None, False, True, False + skipping = 0 for idx, char in enumerate(expr): paren_delta = 0 if not in_quote: @@ -382,10 +418,12 @@ class JSInterpreter(object): return separated[0][1:].strip(), separated[1].strip() @staticmethod - def _all_operators(): - return itertools.chain( - # Ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence - _SC_OPERATORS, _LOG_OPERATORS, _COMP_OPERATORS, _OPERATORS) + def _all_operators(_cached=[]): + if not _cached: + _cached.extend(itertools.chain( + # Ref: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence + _SC_OPERATORS, _LOG_OPERATORS, _COMP_OPERATORS, _OPERATORS)) + return _cached def _operator(self, op, left_val, right_expr, expr, local_vars, allow_recursion): if op in ('||', '&&'): @@ -416,7 +454,7 @@ class JSInterpreter(object): except Exception as e: if allow_undefined: return JS_Undefined - raise self.Exception('Cannot get index {idx:.100}'.format(**locals()), expr=repr(obj), cause=e) + raise self.Exception('Cannot get index {idx!r:.100}'.format(**locals()), expr=repr(obj), cause=e) def _dump(self, obj, namespace): try: @@ -438,6 +476,7 @@ class JSInterpreter(object): _FINALLY_RE = re.compile(r'finally\s*\{') _SWITCH_RE = re.compile(r'switch\s*\(') + @Debugger.wrap_interpreter def interpret_statement(self, stmt, local_vars, allow_recursion=100): if allow_recursion < 0: raise self.Exception('Recursion limit reached') @@ -511,7 +550,6 @@ class JSInterpreter(object): expr = self._dump(inner, local_vars) + outer if expr.startswith('('): - 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` @@ -693,7 +731,7 @@ class JSInterpreter(object): (?P<op>{_OPERATOR_RE})? =(?!=)(?P<expr>.*)$ )|(?P<return> - (?!if|return|true|false|null|undefined)(?P<name>{_NAME_RE})$ + (?!if|return|true|false|null|undefined|NaN|Infinity)(?P<name>{_NAME_RE})$ )|(?P<indexing> (?P<in>{_NAME_RE})\[(?P<idx>.+)\]$ )|(?P<attribute> @@ -727,11 +765,12 @@ class JSInterpreter(object): raise JS_Break() elif expr == 'continue': raise JS_Continue() - elif expr == 'undefined': return JS_Undefined, should_return elif expr == 'NaN': return _NaN, should_return + elif expr == 'Infinity': + return _Infinity, should_return elif md.get('return'): return local_vars[m.group('name')], should_return @@ -760,18 +799,28 @@ class JSInterpreter(object): right_expr = separated.pop() # handle operators that are both unary and binary, minimal BODMAS if op in ('+', '-'): + # simplify/adjust consecutive instances of these operators undone = 0 while len(separated) > 1 and not separated[-1].strip(): undone += 1 separated.pop() if op == '-' and undone % 2 != 0: right_expr = op + right_expr + elif op == '+': + while len(separated) > 1 and separated[-1].strip() in self.OP_CHARS: + right_expr = separated.pop() + right_expr + # hanging op at end of left => unary + (strip) or - (push right) left_val = separated[-1] for dm_op in ('*', '%', '/', '**'): bodmas = tuple(self._separate(left_val, dm_op, skip_delims=skip_delim)) if len(bodmas) > 1 and not bodmas[-1].strip(): expr = op.join(separated) + op + right_expr - right_expr = None + if len(separated) > 1: + separated.pop() + right_expr = op.join((left_val, right_expr)) + else: + separated = [op.join((left_val, right_expr))] + right_expr = None break if right_expr is None: continue @@ -797,6 +846,8 @@ class JSInterpreter(object): def eval_method(): if (variable, member) == ('console', 'debug'): + if Debugger.ENABLED: + Debugger.write(self.interpret_expression('[{}]'.format(arg_str), local_vars, allow_recursion)) return types = { 'String': compat_str, |