diff options
Diffstat (limited to 'youtube_dl/jsinterp.py')
| -rw-r--r-- | youtube_dl/jsinterp.py | 262 |
1 files changed, 0 insertions, 262 deletions
diff --git a/youtube_dl/jsinterp.py b/youtube_dl/jsinterp.py deleted file mode 100644 index 7bda596..0000000 --- a/youtube_dl/jsinterp.py +++ /dev/null @@ -1,262 +0,0 @@ -from __future__ import unicode_literals - -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_$0-9]*' - - -class JSInterpreter(object): - def __init__(self, code, objects=None): - if objects is None: - objects = {} - self.code = code - self._functions = {} - self._objects = objects - - def interpret_statement(self, stmt, local_vars, allow_recursion=100): - if allow_recursion < 0: - raise ExtractorError('Recursion limit reached') - - should_abort = False - stmt = stmt.lstrip() - stmt_m = re.match(r'var\s', stmt) - if stmt_m: - expr = stmt[len(stmt_m.group(0)):] - else: - return_m = re.match(r'return(?:\s+|$)', 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('('): - parens_count = 0 - for m in re.finditer(r'[()]', expr): - if m.group(0) == '(': - parens_count += 1 - else: - parens_count -= 1 - if parens_count == 0: - sub_expr = expr[1:m.start()] - sub_result = self.interpret_expression( - sub_expr, local_vars, allow_recursion) - remaining_expr = expr[m.end():].strip() - if not remaining_expr: - return sub_result - else: - expr = json.dumps(sub_result) + remaining_expr - break - else: - raise ExtractorError('Premature end of parens in %r' % expr) - - for op, opfunc in _ASSIGN_OPERATORS: - m = re.match(r'''(?x) - (?P<out>%s)(?:\[(?P<index>[^\]]+?)\])? - \s*%s - (?P<expr>.*)$''' % (_NAME_RE, re.escape(op)), expr) - if not m: - continue - right_val = self.interpret_expression( - m.group('expr'), local_vars, allow_recursion - 1) - - if m.groupdict().get('index'): - lvar = local_vars[m.group('out')] - idx = self.interpret_expression( - m.group('index'), local_vars, allow_recursion) - assert isinstance(idx, int) - cur = lvar[idx] - val = opfunc(cur, right_val) - lvar[idx] = val - return val - else: - cur = local_vars.get(m.group('out')) - val = opfunc(cur, right_val) - local_vars[m.group('out')] = val - return val - - if expr.isdigit(): - return int(expr) - - var_m = re.match( - r'(?!if|return|true|false)(?P<name>%s)$' % _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 - 1) - return val[idx] - - m = re.match( - r'(?P<var>%s)(?:\.(?P<member>[^(]+)|\[(?P<member2>[^]]+)\])\s*(?:\(+(?P<args>[^()]*)\))?$' % _NAME_RE, - expr) - if m: - variable = m.group('var') - member = remove_quotes(m.group('member') or m.group('member2')) - arg_str = m.group('args') - - if 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] - - assert expr.endswith(')') - # Function call - if arg_str == '': - argvals = tuple() - else: - argvals = tuple([ - self.interpret_expression(v, local_vars, allow_recursion) - for v in arg_str.split(',')]) - - if member == 'split': - assert argvals == ('',) - return list(obj) - if member == 'join': - assert len(argvals) == 1 - return argvals[0].join(obj) - if member == 'reverse': - assert len(argvals) == 0 - obj.reverse() - return obj - if member == 'slice': - assert len(argvals) == 1 - return obj[argvals[0]:] - if member == 'splice': - assert isinstance(obj, list) - index, howMany = argvals - res = [] - for i in range(index, min(index + howMany, len(obj))): - res.append(obj.pop(index)) - return res - - return obj[member](argvals) - - for op, opfunc in _OPERATORS: - m = re.match(r'(?P<x>.+?)%s(?P<y>.+)' % re.escape(op), expr) - if not m: - continue - x, abort = self.interpret_statement( - m.group('x'), local_vars, allow_recursion - 1) - if abort: - raise ExtractorError( - 'Premature left-side return of %s in %r' % (op, expr)) - y, abort = self.interpret_statement( - m.group('y'), local_vars, allow_recursion - 1) - if abort: - raise ExtractorError( - 'Premature right-side return of %s in %r' % (op, expr)) - return opfunc(x, y) - - 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 m.group('args').split(',')]) if len(m.group('args')) > 0 else tuple() - if fname not in self._functions: - self._functions[fname] = self.extract_function(fname) - return self._functions[fname](argvals) - - 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(self, funcname): - 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) - if func_m is None: - raise ExtractorError('Could not find JS function %r' % funcname) - argnames = func_m.group('args').split(',') - - return self.build_function(argnames, func_m.group('code')) - - def call_function(self, funcname, *args): - f = self.extract_function(funcname) - return f(args) - - def build_function(self, argnames, code): - def resf(args): - local_vars = dict(zip(argnames, args)) - for stmt in code.split(';'): - res, abort = self.interpret_statement(stmt, local_vars) - if abort: - break - return res - return resf |