Source code for searx.engines

# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
"""This module implements the engine loader.

Load and initialize the ``engines``, see :py:func:`load_engines` and register
:py:obj:`engine_shortcuts`.

usage::

    load_engines( settings['engines'] )

"""

import sys
import copy
from typing import Dict, List, Optional

from os.path import realpath, dirname
from babel.localedata import locale_identifiers
from searx import logger, settings
from searx.data import ENGINES_LANGUAGES
from searx.network import get
from searx.utils import load_module, match_language, gen_useragent


logger = logger.getChild('engines')
ENGINE_DIR = dirname(realpath(__file__))
BABEL_LANGS = [
    lang_parts[0] + '-' + lang_parts[-1] if len(lang_parts) > 1 else lang_parts[0]
    for lang_parts in (lang_code.split('_') for lang_code in locale_identifiers())
]
ENGINE_DEFAULT_ARGS = {
    "engine_type": "online",
    "inactive": False,
    "disabled": False,
    "timeout": settings["outgoing"]["request_timeout"],
    "shortcut": "-",
    "categories": ["general"],
    "supported_languages": [],
    "language_aliases": {},
    "paging": False,
    "safesearch": False,
    "time_range_support": False,
    "enable_http": False,
    "using_tor_proxy": False,
    "display_error_messages": True,
    "send_accept_language_header": False,
    "tokens": [],
    "about": {},
}
# set automatically when an engine does not have any tab category
OTHER_CATEGORY = 'other'


[docs]class Engine: # pylint: disable=too-few-public-methods """This class is currently never initialized and only used for type hinting.""" name: str engine: str shortcut: str categories: List[str] supported_languages: List[str] about: dict inactive: bool disabled: bool language_support: bool paging: bool safesearch: bool time_range_support: bool timeout: float
# Defaults for the namespace of an engine module, see :py:func:`load_engine` categories = {'general': []} engines: Dict[str, Engine] = {} engine_shortcuts = {} """Simple map of registered *shortcuts* to name of the engine (or ``None``). :: engine_shortcuts[engine.shortcut] = engine.name :meta hide-value: """
[docs]def load_engine(engine_data: dict) -> Optional[Engine]: """Load engine from ``engine_data``. :param dict engine_data: Attributes from YAML ``settings:engines/<engine>`` :return: initialized namespace of the ``<engine>``. 1. create a namespace and load module of the ``<engine>`` 2. update namespace with the defaults from :py:obj:`ENGINE_DEFAULT_ARGS` 3. update namespace with values from ``engine_data`` If engine *is active*, return namespace of the engine, otherwise return ``None``. This function also returns ``None`` if initialization of the namespace fails for one of the following reasons: - engine name contains underscore - engine name is not lowercase - required attribute is not set :py:func:`is_missing_required_attributes` """ engine_name = engine_data['name'] if '_' in engine_name: logger.error('Engine name contains underscore: "{}"'.format(engine_name)) return None if engine_name.lower() != engine_name: logger.warn('Engine name is not lowercase: "{}", converting to lowercase'.format(engine_name)) engine_name = engine_name.lower() engine_data['name'] = engine_name # load_module engine_module = engine_data['engine'] try: engine = load_module(engine_module + '.py', ENGINE_DIR) except (SyntaxError, KeyboardInterrupt, SystemExit, SystemError, ImportError, RuntimeError): logger.exception('Fatal exception in engine "{}"'.format(engine_module)) sys.exit(1) except BaseException: logger.exception('Cannot load engine "{}"'.format(engine_module)) return None update_engine_attributes(engine, engine_data) set_language_attributes(engine) update_attributes_for_tor(engine) if not is_engine_active(engine): return None if is_missing_required_attributes(engine): return None set_loggers(engine, engine_name) if not any(cat in settings['categories_as_tabs'] for cat in engine.categories): engine.categories.append(OTHER_CATEGORY) return engine
def set_loggers(engine, engine_name): # set the logger for engine engine.logger = logger.getChild(engine_name) # the engine may have load some other engines # may sure the logger is initialized # use sys.modules.copy() to avoid "RuntimeError: dictionary changed size during iteration" # see https://github.com/python/cpython/issues/89516 # and https://docs.python.org/3.10/library/sys.html#sys.modules modules = sys.modules.copy() for module_name, module in modules.items(): if ( module_name.startswith("searx.engines") and module_name != "searx.engines.__init__" and not hasattr(module, "logger") ): module_engine_name = module_name.split(".")[-1] module.logger = logger.getChild(module_engine_name) def update_engine_attributes(engine: Engine, engine_data): # set engine attributes from engine_data for param_name, param_value in engine_data.items(): if param_name == 'categories': if isinstance(param_value, str): param_value = list(map(str.strip, param_value.split(','))) engine.categories = param_value elif hasattr(engine, 'about') and param_name == 'about': engine.about = {**engine.about, **engine_data['about']} else: setattr(engine, param_name, param_value) # set default attributes for arg_name, arg_value in ENGINE_DEFAULT_ARGS.items(): if not hasattr(engine, arg_name): setattr(engine, arg_name, copy.deepcopy(arg_value)) def set_language_attributes(engine: Engine): # assign supported languages from json file if engine.name in ENGINES_LANGUAGES: engine.supported_languages = ENGINES_LANGUAGES[engine.name] elif engine.engine in ENGINES_LANGUAGES: # The key of the dictionary ENGINES_LANGUAGES is the *engine name* # configured in settings.xml. When multiple engines are configured in # settings.yml to use the same origin engine (python module) these # additional engines can use the languages from the origin engine. # For this use the configured ``engine: ...`` from settings.yml engine.supported_languages = ENGINES_LANGUAGES[engine.engine] if hasattr(engine, 'language'): # For an engine, when there is `language: ...` in the YAML settings, the # engine supports only one language, in this case # engine.supported_languages should contains this value defined in # settings.yml if engine.language not in engine.supported_languages: raise ValueError( "settings.yml - engine: '%s' / language: '%s' not supported" % (engine.name, engine.language) ) if isinstance(engine.supported_languages, dict): engine.supported_languages = {engine.language: engine.supported_languages[engine.language]} else: engine.supported_languages = [engine.language] # find custom aliases for non standard language codes for engine_lang in engine.supported_languages: iso_lang = match_language(engine_lang, BABEL_LANGS, fallback=None) if ( iso_lang and iso_lang != engine_lang and not engine_lang.startswith(iso_lang) and iso_lang not in engine.supported_languages ): engine.language_aliases[iso_lang] = engine_lang # language_support engine.language_support = len(engine.supported_languages) > 0 # assign language fetching method if auxiliary method exists if hasattr(engine, '_fetch_supported_languages'): headers = { 'User-Agent': gen_useragent(), 'Accept-Language': "en-US,en;q=0.5", # bing needs to set the English language } engine.fetch_supported_languages = ( # pylint: disable=protected-access lambda: engine._fetch_supported_languages(get(engine.supported_languages_url, headers=headers)) ) def update_attributes_for_tor(engine: Engine) -> bool: if using_tor_proxy(engine) and hasattr(engine, 'onion_url'): engine.search_url = engine.onion_url + getattr(engine, 'search_path', '') engine.timeout += settings['outgoing'].get('extra_proxy_timeout', 0)
[docs]def is_missing_required_attributes(engine): """An attribute is required when its name doesn't start with ``_`` (underline). Required attributes must not be ``None``. """ missing = False for engine_attr in dir(engine): if not engine_attr.startswith('_') and getattr(engine, engine_attr) is None: logger.error('Missing engine config attribute: "{0}.{1}"'.format(engine.name, engine_attr)) missing = True return missing
[docs]def using_tor_proxy(engine: Engine): """Return True if the engine configuration declares to use Tor.""" return settings['outgoing'].get('using_tor_proxy') or getattr(engine, 'using_tor_proxy', False)
def is_engine_active(engine: Engine): # check if engine is inactive if engine.inactive is True: return False # exclude onion engines if not using tor if 'onions' in engine.categories and not using_tor_proxy(engine): return False return True def register_engine(engine: Engine): if engine.name in engines: logger.error('Engine config error: ambiguous name: {0}'.format(engine.name)) sys.exit(1) engines[engine.name] = engine if engine.shortcut in engine_shortcuts: logger.error('Engine config error: ambiguous shortcut: {0}'.format(engine.shortcut)) sys.exit(1) engine_shortcuts[engine.shortcut] = engine.name for category_name in engine.categories: categories.setdefault(category_name, []).append(engine)
[docs]def load_engines(engine_list): """usage: ``engine_list = settings['engines']``""" engines.clear() engine_shortcuts.clear() categories.clear() categories['general'] = [] for engine_data in engine_list: engine = load_engine(engine_data) if engine: register_engine(engine) return engines