226 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			226 lines
		
	
	
		
			7.2 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| # SPDX-License-Identifier: AGPL-3.0-or-later
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| # lint: pylint
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| # pylint: disable=missing-function-docstring
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| """This module implements the engine loader.
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| 
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| Load and initialize the ``engines``, see :py:func:`load_engines` and register
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| :py:obj:`engine_shortcuts`.
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| 
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| usage::
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| 
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|     load_engines( settings['engines'] )
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| 
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| """
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| 
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| import sys
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| import copy
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| 
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| from os.path import realpath, dirname
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| from babel.localedata import locale_identifiers
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| from searx import logger, settings
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| from searx.data import ENGINES_LANGUAGES
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| from searx.network import get
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| from searx.utils import load_module, match_language, gen_useragent
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| 
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| 
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| logger = logger.getChild('engines')
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| ENGINE_DIR = dirname(realpath(__file__))
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| BABEL_LANGS = [
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|     lang_parts[0] + '-' + lang_parts[-1] if len(lang_parts) > 1 else lang_parts[0]
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|     for lang_parts in (lang_code.split('_') for lang_code in locale_identifiers())
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| ]
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| ENGINE_DEFAULT_ARGS = {
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|     "engine_type": "online",
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|     "inactive": False,
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|     "disabled": False,
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|     "timeout": settings["outgoing"]["request_timeout"],
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|     "shortcut": "-",
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|     "categories": ["general"],
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|     "supported_languages": [],
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|     "language_aliases": {},
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|     "paging": False,
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|     "safesearch": False,
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|     "time_range_support": False,
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|     "enable_http": False,
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|     "display_error_messages": True,
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|     "tokens": [],
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| }
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| """Defaults for the namespace of an engine module, see :py:func:`load_engine`"""
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| 
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| categories = {'general': []}
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| engines = {}
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| engine_shortcuts = {}
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| """Simple map of registered *shortcuts* to name of the engine (or ``None``).
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| 
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| ::
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| 
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|     engine_shortcuts[engine.shortcut] = engine.name
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| 
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| """
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| 
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| def load_engine(engine_data):
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|     """Load engine from ``engine_data``.
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| 
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|     :param dict engine_data:  Attributes from YAML ``settings:engines/<engine>``
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|     :return: initialized namespace of the ``<engine>``.
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| 
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|     1. create a namespace and load module of the ``<engine>``
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|     2. update namespace with the defaults from :py:obj:`ENGINE_DEFAULT_ARGS`
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|     3. update namespace with values from ``engine_data``
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| 
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|     If engine *is active*, return namespace of the engine, otherwise return
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|     ``None``.
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| 
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|     This function also returns ``None`` if initialization of the namespace fails
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|     for one of the following reasons:
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| 
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|     - engine name contains underscore
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|     - engine name is not lowercase
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|     - required attribute is not set :py:func:`is_missing_required_attributes`
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| 
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|     """
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| 
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|     engine_name = engine_data['name']
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|     if '_' in engine_name:
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|         logger.error('Engine name contains underscore: "{}"'.format(engine_name))
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|         return None
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| 
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|     if engine_name.lower() != engine_name:
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|         logger.warn('Engine name is not lowercase: "{}", converting to lowercase'.format(engine_name))
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|         engine_name = engine_name.lower()
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|         engine_data['name'] = engine_name
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| 
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|     # load_module
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|     engine_module = engine_data['engine']
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|     try:
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|         engine = load_module(engine_module + '.py', ENGINE_DIR)
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|     except (SyntaxError, KeyboardInterrupt, SystemExit, SystemError, ImportError, RuntimeError):
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|         logger.exception('Fatal exception in engine "{}"'.format(engine_module))
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|         sys.exit(1)
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|     except BaseException:
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|         logger.exception('Cannot load engine "{}"'.format(engine_module))
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|         return None
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| 
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|     update_engine_attributes(engine, engine_data)
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|     set_language_attributes(engine)
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|     update_attributes_for_tor(engine)
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| 
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|     if not is_engine_active(engine):
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|         return None
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| 
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|     if is_missing_required_attributes(engine):
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|         return None
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| 
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|     return engine
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| 
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| 
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| def update_engine_attributes(engine, engine_data):
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|     # set engine attributes from engine_data
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|     for param_name, param_value in engine_data.items():
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|         if param_name == 'categories':
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|             if isinstance(param_value, str):
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|                 param_value = list(map(str.strip, param_value.split(',')))
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|             engine.categories = param_value
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|         elif param_name != 'engine':
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|             setattr(engine, param_name, param_value)
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| 
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|     # set default attributes
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|     for arg_name, arg_value in ENGINE_DEFAULT_ARGS.items():
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|         if not hasattr(engine, arg_name):
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|             setattr(engine, arg_name, copy.deepcopy(arg_value))
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| 
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| 
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| def set_language_attributes(engine):
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|     # pylint: disable=protected-access
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|     # assign supported languages from json file
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|     if engine.name in ENGINES_LANGUAGES:
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|         engine.supported_languages = ENGINES_LANGUAGES[engine.name]
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| 
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|     # find custom aliases for non standard language codes
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|     for engine_lang in engine.supported_languages:
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|         iso_lang = match_language(engine_lang, BABEL_LANGS, fallback=None)
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|         if (iso_lang
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|             and iso_lang != engine_lang
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|             and not engine_lang.startswith(iso_lang)
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|             and iso_lang not in engine.supported_languages
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|         ):
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|             engine.language_aliases[iso_lang] = engine_lang
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| 
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|     # language_support
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|     engine.language_support = len(engine.supported_languages) > 0
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| 
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|     # assign language fetching method if auxiliary method exists
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|     if hasattr(engine, '_fetch_supported_languages'):
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|         headers = {
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|             'User-Agent': gen_useragent(),
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|             'Accept-Language': 'ja-JP,ja;q=0.8,en-US;q=0.5,en;q=0.3',  # bing needs a non-English language
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|         }
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|         engine.fetch_supported_languages = (
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|             lambda: engine._fetch_supported_languages(
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|                 get(engine.supported_languages_url, headers=headers))
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|         )
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| 
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| 
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| def update_attributes_for_tor(engine):
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|     if (settings['outgoing'].get('using_tor_proxy')
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|         and hasattr(engine, 'onion_url') ):
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|         engine.search_url = engine.onion_url + getattr(engine, 'search_path', '')
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|         engine.timeout += settings['outgoing'].get('extra_proxy_timeout', 0)
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| 
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| 
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| def is_missing_required_attributes(engine):
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|     """An attribute is required when its name doesn't start with ``_`` (underline).
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|     Required attributes must not be ``None``.
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| 
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|     """
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|     missing = False
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|     for engine_attr in dir(engine):
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|         if not engine_attr.startswith('_') and getattr(engine, engine_attr) is None:
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|             logger.error(
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|                 'Missing engine config attribute: "{0}.{1}"'
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|                 .format(engine.name, engine_attr))
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|             missing = True
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|     return missing
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| 
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| 
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| def is_engine_active(engine):
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|     # check if engine is inactive
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|     if engine.inactive is True:
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|         return False
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| 
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|     # exclude onion engines if not using tor
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|     if ('onions' in engine.categories
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|         and not settings['outgoing'].get('using_tor_proxy') ):
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|         return False
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| 
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|     return True
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| 
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| 
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| def register_engine(engine):
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|     if engine.name in engines:
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|         logger.error('Engine config error: ambigious name: {0}'.format(engine.name))
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|         sys.exit(1)
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|     engines[engine.name] = engine
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| 
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|     if engine.shortcut in engine_shortcuts:
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|         logger.error('Engine config error: ambigious shortcut: {0}'.format(engine.shortcut))
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|         sys.exit(1)
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|     engine_shortcuts[engine.shortcut] = engine.name
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| 
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|     for category_name in engine.categories:
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|         categories.setdefault(category_name, []).append(engine)
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| 
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| 
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| def load_engines(engine_list):
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|     """usage: ``engine_list = settings['engines']``
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|     """
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|     engines.clear()
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|     engine_shortcuts.clear()
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|     categories.clear()
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|     categories['general'] = []
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|     for engine_data in engine_list:
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|         engine = load_engine(engine_data)
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|         if engine:
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|             register_engine(engine)
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|     return engines
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