| """ |
| Recursions are the recipe of |jedi| to conquer Python code. However, someone |
| must stop recursions going mad. Some settings are here to make |jedi| stop at |
| the right time. You can read more about them :ref:`here <settings-recursion>`. |
| |
| Next to the internal ``jedi.inference.cache`` this module also makes |jedi| not |
| thread-safe, because ``execution_recursion_decorator`` uses class variables to |
| count the function calls. |
| |
| .. _settings-recursion: |
| |
| Settings |
| ~~~~~~~~~~ |
| |
| Recursion settings are important if you don't want extremely |
| recursive python code to go absolutely crazy. |
| |
| The default values are based on experiments while completing the |jedi| library |
| itself (inception!). But I don't think there's any other Python library that |
| uses recursion in a similarly extreme way. Completion should also be fast and |
| therefore the quality might not always be maximal. |
| |
| .. autodata:: recursion_limit |
| .. autodata:: total_function_execution_limit |
| .. autodata:: per_function_execution_limit |
| .. autodata:: per_function_recursion_limit |
| """ |
|
|
| from contextlib import contextmanager |
|
|
| from jedi import debug |
| from jedi.inference.base_value import NO_VALUES |
|
|
|
|
| recursion_limit = 15 |
| """ |
| Like :func:`sys.getrecursionlimit()`, just for |jedi|. |
| """ |
| total_function_execution_limit = 200 |
| """ |
| This is a hard limit of how many non-builtin functions can be executed. |
| """ |
| per_function_execution_limit = 6 |
| """ |
| The maximal amount of times a specific function may be executed. |
| """ |
| per_function_recursion_limit = 2 |
| """ |
| A function may not be executed more than this number of times recursively. |
| """ |
|
|
|
|
| class RecursionDetector: |
| def __init__(self): |
| self.pushed_nodes = [] |
|
|
|
|
| @contextmanager |
| def execution_allowed(inference_state, node): |
| """ |
| A decorator to detect recursions in statements. In a recursion a statement |
| at the same place, in the same module may not be executed two times. |
| """ |
| pushed_nodes = inference_state.recursion_detector.pushed_nodes |
|
|
| if node in pushed_nodes: |
| debug.warning('catched stmt recursion: %s @%s', node, |
| getattr(node, 'start_pos', None)) |
| yield False |
| else: |
| try: |
| pushed_nodes.append(node) |
| yield True |
| finally: |
| pushed_nodes.pop() |
|
|
|
|
| def execution_recursion_decorator(default=NO_VALUES): |
| def decorator(func): |
| def wrapper(self, **kwargs): |
| detector = self.inference_state.execution_recursion_detector |
| limit_reached = detector.push_execution(self) |
| try: |
| if limit_reached: |
| result = default |
| else: |
| result = func(self, **kwargs) |
| finally: |
| detector.pop_execution() |
| return result |
| return wrapper |
| return decorator |
|
|
|
|
| class ExecutionRecursionDetector: |
| """ |
| Catches recursions of executions. |
| """ |
| def __init__(self, inference_state): |
| self._inference_state = inference_state |
|
|
| self._recursion_level = 0 |
| self._parent_execution_funcs = [] |
| self._funcdef_execution_counts = {} |
| self._execution_count = 0 |
|
|
| def pop_execution(self): |
| self._parent_execution_funcs.pop() |
| self._recursion_level -= 1 |
|
|
| def push_execution(self, execution): |
| funcdef = execution.tree_node |
|
|
| |
| self._recursion_level += 1 |
| self._parent_execution_funcs.append(funcdef) |
|
|
| module_context = execution.get_root_context() |
|
|
| if module_context.is_builtins_module(): |
| |
| |
| |
| return False |
|
|
| if self._recursion_level > recursion_limit: |
| debug.warning('Recursion limit (%s) reached', recursion_limit) |
| return True |
|
|
| if self._execution_count >= total_function_execution_limit: |
| debug.warning('Function execution limit (%s) reached', total_function_execution_limit) |
| return True |
| self._execution_count += 1 |
|
|
| if self._funcdef_execution_counts.setdefault(funcdef, 0) >= per_function_execution_limit: |
| if module_context.py__name__() == 'typing': |
| return False |
| debug.warning( |
| 'Per function execution limit (%s) reached: %s', |
| per_function_execution_limit, |
| funcdef |
| ) |
| return True |
| self._funcdef_execution_counts[funcdef] += 1 |
|
|
| if self._parent_execution_funcs.count(funcdef) > per_function_recursion_limit: |
| debug.warning( |
| 'Per function recursion limit (%s) reached: %s', |
| per_function_recursion_limit, |
| funcdef |
| ) |
| return True |
| return False |
|
|