Merge pull request #116 from searxng/minor-refactoring-searx-engines

[mod] searx.engines.__init__: refactoring
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Alexandre Flament 2021-06-01 16:40:38 +02:00 committed by GitHub
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7 changed files with 186 additions and 101 deletions

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@ -13,7 +13,14 @@ project = u'searx'
copyright = u'2015-2020, Adam Tauber, Noémi Ványi'
author = u'Adam Tauber'
release, version = VERSION_STRING, VERSION_STRING
highlight_language = 'none'
# hint: sphinx.ext.viewcode won't highlight when 'highlight_language' [1] is set
# to string 'none' [2]
#
# [1] https://www.sphinx-doc.org/en/master/usage/extensions/viewcode.html
# [2] https://www.sphinx-doc.org/en/master/usage/configuration.html#confval-highlight_language
highlight_language = 'default'
# General --------------------------------------------------------------

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@ -9,7 +9,6 @@ Developer documentation
quickstart
contribution_guide
engine_overview
xpath_engine
search_api
plugins
translation

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@ -35,5 +35,6 @@ anyone, you can set up your own, see :ref:`installation`.
searx_extra/index
utils/index
blog/index
src/index
.. _Searx-instances: https://searx.space

14
docs/src/index.rst Normal file
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@ -0,0 +1,14 @@
===========
Source-Code
===========
This is a partial documentation of our source code. We are not aim to document
every item from the source code, but we will add documentation when requested.
.. toctree::
:maxdepth: 2
:caption: Contents
:glob:
searx.*

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@ -0,0 +1,8 @@
.. _load_engines:
============
Load Engines
============
.. automodule:: searx.engines
:members:

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@ -1,130 +1,153 @@
# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
# pylint: disable=missing-function-docstring
"""This module implements the engine loader.
'''
searx is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Load and initialize the ``engines``, see :py:func:`load_engines` and register
:py:obj:`engine_shortcuts`.
searx is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
usage::
You should have received a copy of the GNU Affero General Public License
along with searx. If not, see < http://www.gnu.org/licenses/ >.
load_engines( settings['engines'] )
(C) 2013- by Adam Tauber, <asciimoo@gmail.com>
'''
"""
import sys
import threading
import copy
from os.path import realpath, dirname
from babel.localedata import locale_identifiers
from urllib.parse import urlparse
from operator import itemgetter
from searx import settings
from searx import logger
from searx import logger, settings
from searx.data import ENGINES_LANGUAGES
from searx.exceptions import SearxEngineResponseException
from searx.network import get, initialize as initialize_network, set_context_network_name
from searx.utils import load_module, match_language, get_engine_from_settings, gen_useragent
from searx.network import get
from searx.utils import load_module, match_language, gen_useragent
logger = logger.getChild('engines')
engine_dir = dirname(realpath(__file__))
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,
"display_error_messages": True,
"tokens": [],
}
"""Defaults for the namespace of an engine module, see :py:func:`load_engine`"""
categories = {'general': []}
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())]
engines = {}
engine_shortcuts = {}
engine_default_args = {'paging': False,
'categories': ['general'],
'supported_languages': [],
'safesearch': False,
'timeout': settings['outgoing']['request_timeout'],
'shortcut': '-',
'disabled': False,
'enable_http': False,
'time_range_support': False,
'engine_type': 'online',
'display_error_messages': True,
'tokens': []}
"""Simple map of registered *shortcuts* to name of the engine (or ``None``).
::
engine_shortcuts[engine.shortcut] = engine.name
"""
def load_engine(engine_data):
"""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))
sys.exit(1)
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)
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:
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
return engine
def update_engine_attributes(engine, engine_data):
# set engine attributes from engine_data
for param_name, param_value in engine_data.items():
if param_name == 'engine':
pass
elif param_name == 'categories':
if param_value == 'none':
engine.categories = []
else:
engine.categories = list(map(str.strip, param_value.split(',')))
else:
if param_name == 'categories':
if isinstance(param_value, str):
param_value = list(map(str.strip, param_value.split(',')))
engine.categories = param_value
elif param_name != 'engine':
setattr(engine, param_name, param_value)
for arg_name, arg_value in engine_default_args.items():
# set default attributes
for arg_name, arg_value in ENGINE_DEFAULT_ARGS.items():
if not hasattr(engine, arg_name):
setattr(engine, arg_name, arg_value)
setattr(engine, arg_name, copy.deepcopy(arg_value))
# checking required variables
for engine_attr in dir(engine):
if engine_attr.startswith('_'):
continue
if engine_attr == 'inactive' and getattr(engine, engine_attr) is True:
return None
if getattr(engine, engine_attr) is None:
logger.error('Missing engine config attribute: "{0}.{1}"'
.format(engine.name, engine_attr))
sys.exit(1)
def set_language_attributes(engine):
# pylint: disable=protected-access
# assign supported languages from json file
if engine_data['name'] in ENGINES_LANGUAGES:
setattr(engine, 'supported_languages', ENGINES_LANGUAGES[engine_data['name']])
if engine.name in ENGINES_LANGUAGES:
engine.supported_languages = ENGINES_LANGUAGES[engine.name]
# find custom aliases for non standard language codes
if hasattr(engine, 'supported_languages'):
if hasattr(engine, 'language_aliases'):
language_aliases = getattr(engine, 'language_aliases')
else:
language_aliases = {}
for engine_lang in getattr(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 getattr(engine, 'supported_languages'):
language_aliases[iso_lang] = engine_lang
setattr(engine, 'language_aliases', language_aliases)
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
setattr(engine, 'language_support', len(getattr(engine, 'supported_languages', [])) > 0)
engine.language_support = len(engine.supported_languages) > 0
# assign language fetching method if auxiliary method exists
if hasattr(engine, '_fetch_supported_languages'):
@ -132,38 +155,71 @@ def load_engine(engine_data):
'User-Agent': gen_useragent(),
'Accept-Language': 'ja-JP,ja;q=0.8,en-US;q=0.5,en;q=0.3', # bing needs a non-English language
}
setattr(engine, 'fetch_supported_languages',
lambda: engine._fetch_supported_languages(get(engine.supported_languages_url, headers=headers)))
engine.fetch_supported_languages = (
lambda: engine._fetch_supported_languages(
get(engine.supported_languages_url, headers=headers))
)
# tor related settings
if settings['outgoing'].get('using_tor_proxy'):
# use onion url if using tor.
if hasattr(engine, 'onion_url'):
engine.search_url = engine.onion_url + getattr(engine, 'search_path', '')
elif 'onions' in engine.categories:
# exclude onion engines if not using tor.
return None
engine.timeout += settings['outgoing']['extra_proxy_timeout']
def update_attributes_for_tor(engine):
if (settings['outgoing'].get('using_tor_proxy')
and hasattr(engine, 'onion_url') ):
engine.search_url = engine.onion_url + getattr(engine, 'search_path', '')
engine.timeout += settings['outgoing'].get('extra_proxy_timeout', 0)
for category_name in engine.categories:
categories.setdefault(category_name, []).append(engine)
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
def is_engine_active(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 settings['outgoing'].get('using_tor_proxy') ):
return False
return True
def register_engine(engine):
if engine.name in engines:
logger.error('Engine config error: ambigious name: {0}'.format(engine.name))
sys.exit(1)
engines[engine.name] = engine
if engine.shortcut in engine_shortcuts:
logger.error('Engine config error: ambigious shortcut: {0}'.format(engine.shortcut))
sys.exit(1)
engine_shortcuts[engine.shortcut] = engine.name
return engine
for category_name in engine.categories:
categories.setdefault(category_name, []).append(engine)
def load_engines(engine_list):
global engines, engine_shortcuts
"""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 is not None:
engines[engine.name] = engine
if engine:
register_engine(engine)
return engines