[mod] multithreading only in searx.search.* packages

it prepares the new architecture change,
everything about multithreading in moved in the searx.search.* packages

previously the call to the "init" function of the engines was done in searx.engines:
* the network was not set (request not sent using the defined proxy)
* it requires to monkey patch the code to avoid HTTP requests during the tests

searx/search/processors/__init__.py

@@ -11,9 +11,11 @@ __all__ = [
     'OnlineProcessor',
     'OnlineDictionaryProcessor',
     'OnlineCurrencyProcessor',
-    'processors',
+    'PROCESSORS',
 ]
 
+import threading
+
 from searx import logger
 import searx.engines as engines
 
@@ -24,7 +26,7 @@ from .online_currency import OnlineCurrencyProcessor
 from .abstract import EngineProcessor
 
 logger = logger.getChild('search.processors')
-processors = {}
+PROCESSORS = {}
 """Cache request processores, stored by *engine-name* (:py:func:`initialize`)"""
 
 def get_processor_class(engine_type):
@@ -34,6 +36,7 @@ def get_processor_class(engine_type):
             return c
     return None
 
+
 def get_processor(engine, engine_name):
     """Return processor instance that fits to ``engine.engine.type``)"""
     engine_type = getattr(engine, 'engine_type', 'online')
@@ -42,12 +45,26 @@ def get_processor(engine, engine_name):
         return processor_class(engine, engine_name)
     return None
 
+
+def initialize_processor(processor):
+    """Initialize one processor
+
+    Call the init function of the engine
+    """
+    if processor.has_initialize_function:
+        t = threading.Thread(target=processor.initialize, daemon=True)
+        t.start()
+
+
 def initialize(engine_list):
-    """Initialize all engines and store a processor for each engine in :py:obj:`processors`."""
-    engines.initialize_engines(engine_list)
-    for engine_name, engine in engines.engines.items():
-        processor = get_processor(engine, engine_name)
-        if processor is None:
-            logger.error('Error get processor for engine %s', engine_name)
-        else:
-            processors[engine_name] = processor
+    """Initialize all engines and store a processor for each engine in :py:obj:`PROCESSORS`."""
+    for engine_data in engine_list:
+        engine_name = engine_data['name']
+        engine = engines.engines.get(engine_name)
+        if engine:
+            processor = get_processor(engine, engine_name)
+            initialize_processor(processor)
+            if processor is None:
+                logger.error('Error get processor for engine %s', engine_name)
+            else:
+                PROCESSORS[engine_name] = processor

searx/search/processors/abstract.py

@@ -13,7 +13,8 @@ from searx import logger
 from searx.engines import settings
 from searx.network import get_time_for_thread, get_network
 from searx.metrics import histogram_observe, counter_inc, count_exception, count_error
-from searx.exceptions import SearxEngineAccessDeniedException
+from searx.exceptions import SearxEngineAccessDeniedException, SearxEngineResponseException
+from searx.utils import get_engine_from_settings
 
 logger = logger.getChild('searx.search.processor')
 SUSPENDED_STATUS = {}
@@ -66,6 +67,20 @@ class EngineProcessor(ABC):
         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:
+            logger.warn('%s engine: Fail to initialize // %s', self.engine_name, exc)
+        except Exception:  # pylint: disable=broad-except
+            logger.exception('%s engine: Fail to initialize', self.engine_name)
+        else:
+            logger.debug('%s engine: Initialized', self.engine_name)
+
+    @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):

searx/search/processors/online.py

@@ -5,7 +5,7 @@
 
 """
 
-from time import time
+from timeit import default_timer
 import asyncio
 import httpx
 
@@ -40,6 +40,15 @@ class OnlineProcessor(EngineProcessor):
 
     engine_type = 'online'
 
+    def initialize(self):
+        # set timeout for all HTTP requests
+        searx.network.set_timeout_for_thread(self.engine.timeout, start_time=default_timer())
+        # reset the HTTP total time
+        searx.network.reset_time_for_thread()
+        # set the network
+        searx.network.set_context_network_name(self.engine_name)
+        super().initialize()
+
     def get_params(self, search_query, engine_category):
         params = super().get_params(search_query, engine_category)
         if params is None:
@@ -139,7 +148,7 @@ class OnlineProcessor(EngineProcessor):
             self.handle_exception(result_container, e, suspend=True)
             logger.error("engine {0} : HTTP requests timeout"
                          "(search duration : {1} s, timeout: {2} s) : {3}"
-                         .format(self.engine_name, time() - start_time,
+                         .format(self.engine_name, default_timer() - start_time,
                                  timeout_limit,
                                  e.__class__.__name__))
         except (httpx.HTTPError, httpx.StreamError) as e:
@@ -147,7 +156,7 @@ class OnlineProcessor(EngineProcessor):
             self.handle_exception(result_container, e, suspend=True)
             logger.exception("engine {0} : requests exception"
                              "(search duration : {1} s, timeout: {2} s) : {3}"
-                             .format(self.engine_name, time() - start_time,
+                             .format(self.engine_name, default_timer() - start_time,
                                      timeout_limit,
                                      e))
         except SearxEngineCaptchaException as e: