mirror of
https://github.com/yt-dlp/yt-dlp
synced 2024-12-30 22:24:28 +01:00
540 lines
21 KiB
Python
540 lines
21 KiB
Python
from collections.abc import MutableMapping
|
|
import json
|
|
import operator
|
|
import re
|
|
|
|
from .utils import (
|
|
ExtractorError,
|
|
remove_quotes,
|
|
)
|
|
|
|
_OPERATORS = [
|
|
('|', operator.or_),
|
|
('^', operator.xor),
|
|
('&', operator.and_),
|
|
('>>', operator.rshift),
|
|
('<<', operator.lshift),
|
|
('-', operator.sub),
|
|
('+', operator.add),
|
|
('%', operator.mod),
|
|
('/', operator.truediv),
|
|
('*', operator.mul),
|
|
]
|
|
_ASSIGN_OPERATORS = [(op + '=', opfunc) for op, opfunc in _OPERATORS]
|
|
_ASSIGN_OPERATORS.append(('=', (lambda cur, right: right)))
|
|
|
|
_NAME_RE = r'[a-zA-Z_$][a-zA-Z_$0-9]*'
|
|
|
|
_MATCHING_PARENS = dict(zip('({[', ')}]'))
|
|
|
|
|
|
class JS_Break(ExtractorError):
|
|
def __init__(self):
|
|
ExtractorError.__init__(self, 'Invalid break')
|
|
|
|
|
|
class JS_Continue(ExtractorError):
|
|
def __init__(self):
|
|
ExtractorError.__init__(self, 'Invalid continue')
|
|
|
|
|
|
class LocalNameSpace(MutableMapping):
|
|
def __init__(self, *stack):
|
|
self.stack = tuple(stack)
|
|
|
|
def __getitem__(self, key):
|
|
for scope in self.stack:
|
|
if key in scope:
|
|
return scope[key]
|
|
raise KeyError(key)
|
|
|
|
def __setitem__(self, key, value):
|
|
for scope in self.stack:
|
|
if key in scope:
|
|
scope[key] = value
|
|
break
|
|
else:
|
|
self.stack[0][key] = value
|
|
return value
|
|
|
|
def __delitem__(self, key):
|
|
raise NotImplementedError('Deleting is not supported')
|
|
|
|
def __iter__(self):
|
|
for scope in self.stack:
|
|
yield from scope
|
|
|
|
def __len__(self, key):
|
|
return len(iter(self))
|
|
|
|
def __repr__(self):
|
|
return f'LocalNameSpace{self.stack}'
|
|
|
|
|
|
class JSInterpreter(object):
|
|
def __init__(self, code, objects=None):
|
|
if objects is None:
|
|
objects = {}
|
|
self.code = code
|
|
self._functions = {}
|
|
self._objects = objects
|
|
self.__named_object_counter = 0
|
|
|
|
def _named_object(self, namespace, obj):
|
|
self.__named_object_counter += 1
|
|
name = f'__yt_dlp_jsinterp_obj{self.__named_object_counter}'
|
|
namespace[name] = obj
|
|
return name
|
|
|
|
@staticmethod
|
|
def _separate(expr, delim=',', max_split=None):
|
|
if not expr:
|
|
return
|
|
counters = {k: 0 for k in _MATCHING_PARENS.values()}
|
|
start, splits, pos, delim_len = 0, 0, 0, len(delim) - 1
|
|
for idx, char in enumerate(expr):
|
|
if char in _MATCHING_PARENS:
|
|
counters[_MATCHING_PARENS[char]] += 1
|
|
elif char in counters:
|
|
counters[char] -= 1
|
|
if char != delim[pos] or any(counters.values()):
|
|
pos = 0
|
|
continue
|
|
elif pos != delim_len:
|
|
pos += 1
|
|
continue
|
|
yield expr[start: idx - delim_len]
|
|
start, pos = idx + 1, 0
|
|
splits += 1
|
|
if max_split and splits >= max_split:
|
|
break
|
|
yield expr[start:]
|
|
|
|
@staticmethod
|
|
def _separate_at_paren(expr, delim):
|
|
separated = list(JSInterpreter._separate(expr, delim, 1))
|
|
if len(separated) < 2:
|
|
raise ExtractorError(f'No terminating paren {delim} in {expr}')
|
|
return separated[0][1:].strip(), separated[1].strip()
|
|
|
|
def interpret_statement(self, stmt, local_vars, allow_recursion=100):
|
|
if allow_recursion < 0:
|
|
raise ExtractorError('Recursion limit reached')
|
|
|
|
sub_statements = list(self._separate(stmt, ';'))
|
|
stmt = (sub_statements or ['']).pop()
|
|
for sub_stmt in sub_statements:
|
|
ret, should_abort = self.interpret_statement(sub_stmt, local_vars, allow_recursion - 1)
|
|
if should_abort:
|
|
return ret
|
|
|
|
should_abort = False
|
|
stmt = stmt.lstrip()
|
|
stmt_m = re.match(r'var\s', stmt)
|
|
if stmt_m:
|
|
expr = stmt[len(stmt_m.group(0)):]
|
|
else:
|
|
return_m = re.match(r'return(?:\s+|$)', stmt)
|
|
if return_m:
|
|
expr = stmt[len(return_m.group(0)):]
|
|
should_abort = True
|
|
else:
|
|
# Try interpreting it as an expression
|
|
expr = stmt
|
|
|
|
v = self.interpret_expression(expr, local_vars, allow_recursion)
|
|
return v, should_abort
|
|
|
|
def interpret_expression(self, expr, local_vars, allow_recursion):
|
|
expr = expr.strip()
|
|
if expr == '': # Empty expression
|
|
return None
|
|
|
|
if expr.startswith('{'):
|
|
inner, outer = self._separate_at_paren(expr, '}')
|
|
inner, should_abort = self.interpret_statement(inner, local_vars, allow_recursion - 1)
|
|
if not outer or should_abort:
|
|
return inner
|
|
else:
|
|
expr = json.dumps(inner) + outer
|
|
|
|
if expr.startswith('('):
|
|
inner, outer = self._separate_at_paren(expr, ')')
|
|
inner = self.interpret_expression(inner, local_vars, allow_recursion)
|
|
if not outer:
|
|
return inner
|
|
else:
|
|
expr = json.dumps(inner) + outer
|
|
|
|
if expr.startswith('['):
|
|
inner, outer = self._separate_at_paren(expr, ']')
|
|
name = self._named_object(local_vars, [
|
|
self.interpret_expression(item, local_vars, allow_recursion)
|
|
for item in self._separate(inner)])
|
|
expr = name + outer
|
|
|
|
m = re.match(r'try\s*', expr)
|
|
if m:
|
|
if expr[m.end()] == '{':
|
|
try_expr, expr = self._separate_at_paren(expr[m.end():], '}')
|
|
else:
|
|
try_expr, expr = expr[m.end() - 1:], ''
|
|
ret, should_abort = self.interpret_statement(try_expr, local_vars, allow_recursion - 1)
|
|
if should_abort:
|
|
return ret
|
|
return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
|
|
|
|
m = re.match(r'catch\s*\(', expr)
|
|
if m:
|
|
# We ignore the catch block
|
|
_, expr = self._separate_at_paren(expr, '}')
|
|
return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
|
|
|
|
m = re.match(r'for\s*\(', expr)
|
|
if m:
|
|
constructor, remaining = self._separate_at_paren(expr[m.end() - 1:], ')')
|
|
if remaining.startswith('{'):
|
|
body, expr = self._separate_at_paren(remaining, '}')
|
|
else:
|
|
m = re.match(r'switch\s*\(', remaining) # FIXME
|
|
if m:
|
|
switch_val, remaining = self._separate_at_paren(remaining[m.end() - 1:], ')')
|
|
body, expr = self._separate_at_paren(remaining, '}')
|
|
body = 'switch(%s){%s}' % (switch_val, body)
|
|
else:
|
|
body, expr = remaining, ''
|
|
start, cndn, increment = self._separate(constructor, ';')
|
|
if self.interpret_statement(start, local_vars, allow_recursion - 1)[1]:
|
|
raise ExtractorError(
|
|
f'Premature return in the initialization of a for loop in {constructor!r}')
|
|
while True:
|
|
if not self.interpret_expression(cndn, local_vars, allow_recursion):
|
|
break
|
|
try:
|
|
ret, should_abort = self.interpret_statement(body, local_vars, allow_recursion - 1)
|
|
if should_abort:
|
|
return ret
|
|
except JS_Break:
|
|
break
|
|
except JS_Continue:
|
|
pass
|
|
if self.interpret_statement(increment, local_vars, allow_recursion - 1)[1]:
|
|
raise ExtractorError(
|
|
f'Premature return in the initialization of a for loop in {constructor!r}')
|
|
return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
|
|
|
|
m = re.match(r'switch\s*\(', expr)
|
|
if m:
|
|
switch_val, remaining = self._separate_at_paren(expr[m.end() - 1:], ')')
|
|
switch_val = self.interpret_expression(switch_val, local_vars, allow_recursion)
|
|
body, expr = self._separate_at_paren(remaining, '}')
|
|
items = body.replace('default:', 'case default:').split('case ')[1:]
|
|
for default in (False, True):
|
|
matched = False
|
|
for item in items:
|
|
case, stmt = [i.strip() for i in self._separate(item, ':', 1)]
|
|
if default:
|
|
matched = matched or case == 'default'
|
|
elif not matched:
|
|
matched = case != 'default' and switch_val == self.interpret_expression(case, local_vars, allow_recursion)
|
|
if not matched:
|
|
continue
|
|
try:
|
|
ret, should_abort = self.interpret_statement(stmt, local_vars, allow_recursion - 1)
|
|
if should_abort:
|
|
return ret
|
|
except JS_Break:
|
|
break
|
|
if matched:
|
|
break
|
|
return self.interpret_statement(expr, local_vars, allow_recursion - 1)[0]
|
|
|
|
# Comma separated statements
|
|
sub_expressions = list(self._separate(expr))
|
|
expr = sub_expressions.pop().strip() if sub_expressions else ''
|
|
for sub_expr in sub_expressions:
|
|
self.interpret_expression(sub_expr, local_vars, allow_recursion)
|
|
|
|
for m in re.finditer(rf'''(?x)
|
|
(?P<pre_sign>\+\+|--)(?P<var1>{_NAME_RE})|
|
|
(?P<var2>{_NAME_RE})(?P<post_sign>\+\+|--)''', expr):
|
|
var = m.group('var1') or m.group('var2')
|
|
start, end = m.span()
|
|
sign = m.group('pre_sign') or m.group('post_sign')
|
|
ret = local_vars[var]
|
|
local_vars[var] += 1 if sign[0] == '+' else -1
|
|
if m.group('pre_sign'):
|
|
ret = local_vars[var]
|
|
expr = expr[:start] + json.dumps(ret) + expr[end:]
|
|
|
|
for op, opfunc in _ASSIGN_OPERATORS:
|
|
m = re.match(r'''(?x)
|
|
(?P<out>%s)(?:\[(?P<index>[^\]]+?)\])?
|
|
\s*%s
|
|
(?P<expr>.*)$''' % (_NAME_RE, re.escape(op)), expr)
|
|
if not m:
|
|
continue
|
|
right_val = self.interpret_expression(m.group('expr'), local_vars, allow_recursion)
|
|
|
|
if m.groupdict().get('index'):
|
|
lvar = local_vars[m.group('out')]
|
|
idx = self.interpret_expression(m.group('index'), local_vars, allow_recursion)
|
|
if not isinstance(idx, int):
|
|
raise ExtractorError(f'List indices must be integers: {idx}')
|
|
cur = lvar[idx]
|
|
val = opfunc(cur, right_val)
|
|
lvar[idx] = val
|
|
return val
|
|
else:
|
|
cur = local_vars.get(m.group('out'))
|
|
val = opfunc(cur, right_val)
|
|
local_vars[m.group('out')] = val
|
|
return val
|
|
|
|
if expr.isdigit():
|
|
return int(expr)
|
|
|
|
if expr == 'break':
|
|
raise JS_Break()
|
|
elif expr == 'continue':
|
|
raise JS_Continue()
|
|
|
|
var_m = re.match(
|
|
r'(?!if|return|true|false|null)(?P<name>%s)$' % _NAME_RE,
|
|
expr)
|
|
if var_m:
|
|
return local_vars[var_m.group('name')]
|
|
|
|
try:
|
|
return json.loads(expr)
|
|
except ValueError:
|
|
pass
|
|
|
|
m = re.match(
|
|
r'(?P<in>%s)\[(?P<idx>.+)\]$' % _NAME_RE, expr)
|
|
if m:
|
|
val = local_vars[m.group('in')]
|
|
idx = self.interpret_expression(m.group('idx'), local_vars, allow_recursion)
|
|
return val[idx]
|
|
|
|
for op, opfunc in _OPERATORS:
|
|
separated = list(self._separate(expr, op))
|
|
if len(separated) < 2:
|
|
continue
|
|
right_val = separated.pop()
|
|
left_val = op.join(separated)
|
|
left_val, should_abort = self.interpret_statement(
|
|
left_val, local_vars, allow_recursion - 1)
|
|
if should_abort:
|
|
raise ExtractorError(f'Premature left-side return of {op} in {expr!r}')
|
|
right_val, should_abort = self.interpret_statement(
|
|
right_val, local_vars, allow_recursion - 1)
|
|
if should_abort:
|
|
raise ExtractorError(f'Premature right-side return of {op} in {expr!r}')
|
|
return opfunc(left_val or 0, right_val)
|
|
|
|
m = re.match(
|
|
r'(?P<var>%s)(?:\.(?P<member>[^(]+)|\[(?P<member2>[^]]+)\])\s*' % _NAME_RE,
|
|
expr)
|
|
if m:
|
|
variable = m.group('var')
|
|
member = remove_quotes(m.group('member') or m.group('member2'))
|
|
arg_str = expr[m.end():]
|
|
if arg_str.startswith('('):
|
|
arg_str, remaining = self._separate_at_paren(arg_str, ')')
|
|
else:
|
|
arg_str, remaining = None, arg_str
|
|
|
|
def assertion(cndn, msg):
|
|
""" assert, but without risk of getting optimized out """
|
|
if not cndn:
|
|
raise ExtractorError(f'{member} {msg}: {expr}')
|
|
|
|
def eval_method():
|
|
nonlocal member
|
|
if variable == 'String':
|
|
obj = str
|
|
elif variable in local_vars:
|
|
obj = local_vars[variable]
|
|
else:
|
|
if variable not in self._objects:
|
|
self._objects[variable] = self.extract_object(variable)
|
|
obj = self._objects[variable]
|
|
|
|
if arg_str is None:
|
|
# Member access
|
|
if member == 'length':
|
|
return len(obj)
|
|
return obj[member]
|
|
|
|
# Function call
|
|
argvals = [
|
|
self.interpret_expression(v, local_vars, allow_recursion)
|
|
for v in self._separate(arg_str)]
|
|
|
|
if obj == str:
|
|
if member == 'fromCharCode':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
return ''.join(map(chr, argvals))
|
|
raise ExtractorError(f'Unsupported string method {member}')
|
|
|
|
if member == 'split':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
assertion(argvals == [''], 'with arguments is not implemented')
|
|
return list(obj)
|
|
elif member == 'join':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(len(argvals) == 1, 'takes exactly one argument')
|
|
return argvals[0].join(obj)
|
|
elif member == 'reverse':
|
|
assertion(not argvals, 'does not take any arguments')
|
|
obj.reverse()
|
|
return obj
|
|
elif member == 'slice':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(len(argvals) == 1, 'takes exactly one argument')
|
|
return obj[argvals[0]:]
|
|
elif member == 'splice':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(argvals, 'takes one or more arguments')
|
|
index, howMany = map(int, (argvals + [len(obj)])[:2])
|
|
if index < 0:
|
|
index += len(obj)
|
|
add_items = argvals[2:]
|
|
res = []
|
|
for i in range(index, min(index + howMany, len(obj))):
|
|
res.append(obj.pop(index))
|
|
for i, item in enumerate(add_items):
|
|
obj.insert(index + i, item)
|
|
return res
|
|
elif member == 'unshift':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(argvals, 'takes one or more arguments')
|
|
for item in reversed(argvals):
|
|
obj.insert(0, item)
|
|
return obj
|
|
elif member == 'pop':
|
|
assertion(isinstance(obj, list), 'must be applied on a list')
|
|
assertion(not argvals, 'does not take any arguments')
|
|
if not obj:
|
|
return
|
|
return obj.pop()
|
|
elif member == 'push':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
obj.extend(argvals)
|
|
return obj
|
|
elif member == 'forEach':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
assertion(len(argvals) <= 2, 'takes at-most 2 arguments')
|
|
f, this = (argvals + [''])[:2]
|
|
return [f((item, idx, obj), this=this) for idx, item in enumerate(obj)]
|
|
elif member == 'indexOf':
|
|
assertion(argvals, 'takes one or more arguments')
|
|
assertion(len(argvals) <= 2, 'takes at-most 2 arguments')
|
|
idx, start = (argvals + [0])[:2]
|
|
try:
|
|
return obj.index(idx, start)
|
|
except ValueError:
|
|
return -1
|
|
|
|
if isinstance(obj, list):
|
|
member = int(member)
|
|
return obj[member](argvals)
|
|
|
|
if remaining:
|
|
return self.interpret_expression(
|
|
self._named_object(local_vars, eval_method()) + remaining,
|
|
local_vars, allow_recursion)
|
|
else:
|
|
return eval_method()
|
|
|
|
m = re.match(r'^(?P<func>%s)\((?P<args>[a-zA-Z0-9_$,]*)\)$' % _NAME_RE, expr)
|
|
if m:
|
|
fname = m.group('func')
|
|
argvals = tuple([
|
|
int(v) if v.isdigit() else local_vars[v]
|
|
for v in self._separate(m.group('args'))])
|
|
if fname in local_vars:
|
|
return local_vars[fname](argvals)
|
|
elif fname not in self._functions:
|
|
self._functions[fname] = self.extract_function(fname)
|
|
return self._functions[fname](argvals)
|
|
|
|
if expr:
|
|
raise ExtractorError('Unsupported JS expression %r' % expr)
|
|
|
|
def extract_object(self, objname):
|
|
_FUNC_NAME_RE = r'''(?:[a-zA-Z$0-9]+|"[a-zA-Z$0-9]+"|'[a-zA-Z$0-9]+')'''
|
|
obj = {}
|
|
obj_m = re.search(
|
|
r'''(?x)
|
|
(?<!this\.)%s\s*=\s*{\s*
|
|
(?P<fields>(%s\s*:\s*function\s*\(.*?\)\s*{.*?}(?:,\s*)?)*)
|
|
}\s*;
|
|
''' % (re.escape(objname), _FUNC_NAME_RE),
|
|
self.code)
|
|
fields = obj_m.group('fields')
|
|
# Currently, it only supports function definitions
|
|
fields_m = re.finditer(
|
|
r'''(?x)
|
|
(?P<key>%s)\s*:\s*function\s*\((?P<args>[a-z,]+)\){(?P<code>[^}]+)}
|
|
''' % _FUNC_NAME_RE,
|
|
fields)
|
|
for f in fields_m:
|
|
argnames = f.group('args').split(',')
|
|
obj[remove_quotes(f.group('key'))] = self.build_function(argnames, f.group('code'))
|
|
|
|
return obj
|
|
|
|
def extract_function_code(self, funcname):
|
|
""" @returns argnames, code """
|
|
func_m = re.search(
|
|
r'''(?x)
|
|
(?:function\s+%s|[{;,]\s*%s\s*=\s*function|var\s+%s\s*=\s*function)\s*
|
|
\((?P<args>[^)]*)\)\s*
|
|
(?P<code>\{(?:(?!};)[^"]|"([^"]|\\")*")+\})''' % (
|
|
re.escape(funcname), re.escape(funcname), re.escape(funcname)),
|
|
self.code)
|
|
code, _ = self._separate_at_paren(func_m.group('code'), '}') # refine the match
|
|
if func_m is None:
|
|
raise ExtractorError('Could not find JS function %r' % funcname)
|
|
return func_m.group('args').split(','), code
|
|
|
|
def extract_function(self, funcname):
|
|
return self.extract_function_from_code(*self.extract_function_code(funcname))
|
|
|
|
def extract_function_from_code(self, argnames, code, *global_stack):
|
|
local_vars = {}
|
|
while True:
|
|
mobj = re.search(r'function\((?P<args>[^)]*)\)\s*{', code)
|
|
if mobj is None:
|
|
break
|
|
start, body_start = mobj.span()
|
|
body, remaining = self._separate_at_paren(code[body_start - 1:], '}')
|
|
name = self._named_object(
|
|
local_vars,
|
|
self.extract_function_from_code(
|
|
[str.strip(x) for x in mobj.group('args').split(',')],
|
|
body, local_vars, *global_stack))
|
|
code = code[:start] + name + remaining
|
|
return self.build_function(argnames, code, local_vars, *global_stack)
|
|
|
|
def call_function(self, funcname, *args):
|
|
return self.extract_function(funcname)(args)
|
|
|
|
def build_function(self, argnames, code, *global_stack):
|
|
global_stack = list(global_stack) or [{}]
|
|
local_vars = global_stack.pop(0)
|
|
|
|
def resf(args, **kwargs):
|
|
local_vars.update({
|
|
**dict(zip(argnames, args)),
|
|
**kwargs
|
|
})
|
|
var_stack = LocalNameSpace(local_vars, *global_stack)
|
|
for stmt in self._separate(code.replace('\n', ''), ';'):
|
|
ret, should_abort = self.interpret_statement(stmt, var_stack)
|
|
if should_abort:
|
|
break
|
|
return ret
|
|
return resf
|