Source code for

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint

"""Abstract base classes for engine request processors.


import threading
from abc import abstractmethod, ABC
from timeit import default_timer
from typing import Dict, Union

from searx import settings, logger
from searx.engines import engines
from import get_time_for_thread, get_network
from searx.metrics import histogram_observe, counter_inc, count_exception, count_error
from searx.exceptions import SearxEngineAccessDeniedException, SearxEngineResponseException
from searx.utils import get_engine_from_settings

logger = logger.getChild('')
SUSPENDED_STATUS: Dict[Union[int, str], 'SuspendedStatus'] = {}

[docs] class SuspendedStatus: """Class to handle suspend state.""" __slots__ = 'suspend_end_time', 'suspend_reason', 'continuous_errors', 'lock' def __init__(self): self.lock = threading.Lock() self.continuous_errors = 0 self.suspend_end_time = 0 self.suspend_reason = None @property def is_suspended(self): return self.suspend_end_time >= default_timer() def suspend(self, suspended_time, suspend_reason): with self.lock: # update continuous_errors / suspend_end_time self.continuous_errors += 1 if suspended_time is None: suspended_time = min( settings['search']['max_ban_time_on_fail'], self.continuous_errors * settings['search']['ban_time_on_fail'], ) self.suspend_end_time = default_timer() + suspended_time self.suspend_reason = suspend_reason logger.debug('Suspend for %i seconds', suspended_time) def resume(self): with self.lock: # reset the suspend variables self.continuous_errors = 0 self.suspend_end_time = 0 self.suspend_reason = None
[docs] class EngineProcessor(ABC): """Base classes used for all types of request processors.""" __slots__ = 'engine', 'engine_name', 'lock', 'suspended_status', 'logger' def __init__(self, engine, engine_name: str): self.engine = engine self.engine_name = engine_name self.logger = engines[engine_name].logger key = get_network(self.engine_name) key = id(key) if key else self.engine_name self.suspended_status = SUSPENDED_STATUS.setdefault(key, SuspendedStatus()) def initialize(self): try: self.engine.init(get_engine_from_settings(self.engine_name)) except SearxEngineResponseException as exc: self.logger.warning('Fail to initialize // %s', exc) except Exception: # pylint: disable=broad-except self.logger.exception('Fail to initialize') else: self.logger.debug('Initialized') @property def has_initialize_function(self): return hasattr(self.engine, 'init') def handle_exception(self, result_container, exception_or_message, suspend=False): # update result_container if isinstance(exception_or_message, BaseException): exception_class = exception_or_message.__class__ module_name = getattr(exception_class, '__module__', 'builtins') module_name = '' if module_name == 'builtins' else module_name + '.' error_message = module_name + exception_class.__qualname__ else: error_message = exception_or_message result_container.add_unresponsive_engine(self.engine_name, error_message) # metrics counter_inc('engine', self.engine_name, 'search', 'count', 'error') if isinstance(exception_or_message, BaseException): count_exception(self.engine_name, exception_or_message) else: count_error(self.engine_name, exception_or_message) # suspend the engine ? if suspend: suspended_time = None if isinstance(exception_or_message, SearxEngineAccessDeniedException): suspended_time = exception_or_message.suspended_time self.suspended_status.suspend(suspended_time, error_message) # pylint: disable=no-member def _extend_container_basic(self, result_container, start_time, search_results): # update result_container result_container.extend(self.engine_name, search_results) engine_time = default_timer() - start_time page_load_time = get_time_for_thread() result_container.add_timing(self.engine_name, engine_time, page_load_time) # metrics counter_inc('engine', self.engine_name, 'search', 'count', 'successful') histogram_observe(engine_time, 'engine', self.engine_name, 'time', 'total') if page_load_time is not None: histogram_observe(page_load_time, 'engine', self.engine_name, 'time', 'http') def extend_container(self, result_container, start_time, search_results): if getattr(threading.current_thread(), '_timeout', False): # the main thread is not waiting anymore self.handle_exception(result_container, 'timeout', None) else: # check if the engine accepted the request if search_results is not None: self._extend_container_basic(result_container, start_time, search_results) self.suspended_status.resume() def extend_container_if_suspended(self, result_container): if self.suspended_status.is_suspended: result_container.add_unresponsive_engine( self.engine_name, self.suspended_status.suspend_reason, suspended=True ) return True return False
[docs] def get_params(self, search_query, engine_category): """Returns a set of (see :ref:`request params <engine request arguments>`) or ``None`` if request is not supported. Not supported conditions (``None`` is returned): - A page-number > 1 when engine does not support paging. - A time range when the engine does not support time range. """ # if paging is not supported, skip if search_query.pageno > 1 and not self.engine.paging: return None # if time_range is not supported, skip if search_query.time_range and not self.engine.time_range_support: return None params = {} params['category'] = engine_category params['pageno'] = search_query.pageno params['safesearch'] = search_query.safesearch params['time_range'] = search_query.time_range params['engine_data'] = search_query.engine_data.get(self.engine_name, {}) params['searxng_locale'] = search_query.lang # deprecated / vintage --> use params['searxng_locale'] # # Conditions related to engine's traits are implemented in engine.traits # module. Don't do 'locale' decisions here in the abstract layer of the # search processor, just pass the value from user's choice unchanged to # the engine request. if hasattr(self.engine, 'language') and self.engine.language: params['language'] = self.engine.language else: params['language'] = search_query.lang return params
@abstractmethod def search(self, query, params, result_container, start_time, timeout_limit): pass def get_tests(self): tests = getattr(self.engine, 'tests', None) if tests is None: tests = getattr(self.engine, 'additional_tests', {}) tests.update(self.get_default_tests()) return tests def get_default_tests(self): return {}