Server service actor (#527)

* actor server_service begin
* __responses in ServerSerice to __init__

analytics/analytics/services/data_service.py

@@ -71,13 +71,13 @@ class DataService:
             'content': content
         }
         message = ServerMessage('FILE_SAVE', message_payload)
-        await self.server_service.send_request(message)
+        await self.server_service.send_request_to_server(message)
 
     async def load_file_content(self, file_descriptor: FileDescriptor) -> str:
         self.__check_lock(file_descriptor)
         message_payload = { 'filename': file_descriptor.filename }
         message = ServerMessage('FILE_LOAD', message_payload)
-        return await self.server_service.send_request(message)
+        return await self.server_service.send_request_to_server(message)
 
     def __check_lock(self, file_descriptor: FileDescriptor):
         filename = file_descriptor.filename

analytics/analytics/services/server_service.py

@@ -7,11 +7,18 @@ import logging
 import json
 import asyncio
 import traceback
+
+import utils.concurrent
+
 from typing import Optional
 
 logger = logging.getLogger('SERVER_SERVICE')
 
 
+PARSE_MESSAGE_OR_SAVE_LOOP_INTERRUPTED = False
+SERVER_SOCKET_RECV_LOOP_INTERRUPTED = False
+
+
 class ServerMessage:
     def __init__(self, method: str, payload: object = None, request_id: int = None):
         self.method = method
@@ -39,61 +46,81 @@ class ServerMessage:
             request_id = json['requestId']
         return ServerMessage(method, payload, request_id)
 
-class ServerService:
+class ServerService(utils.concurrent.AsyncZmqActor):
 
     def __init__(self):
-        logger.info("Binding to %s ..." % config.ZMQ_CONNECTION_STRING)
-        self.context = zmq.asyncio.Context()
-        self.socket = self.context.socket(zmq.PAIR)
-        self.socket.bind(config.ZMQ_CONNECTION_STRING)
-        self.request_next_id = 1
-        self.responses = dict()
-        self._aiter_inited = False
+        super(ServerService, self).__init__()
+        self.__aiter_inited = False
+        self.__request_next_id = 1
+        self.__responses = dict()
+        self.start()
+
+    async def send_message_to_server(self, message: ServerMessage):
+        # Following message will be sent to actor's self._on_message()
+        # We do it cuz we created self.__server_socket in self._run() method,
+        # which runs in the actor's thread, not the thread we created ServerService
+
+        # in theory, we can try to use zmq.proxy:
+        # zmq.proxy(self.__actor_socket, self.__server_socket)
+        # and do here something like:
+        # self.__actor_socket.send_string(json.dumps(message.toJSON()))
+        await self._put_message_to_thread(json.dumps(message.toJSON()))
+
+    async def send_request_to_server(self, message: ServerMessage) -> object:
+        if message.request_id is not None:
+            raise ValueError('Message can`t have request_id before it is scheduled')
+        request_id = message.request_id = self.__request_next_id
+        self.request_next_id = self.__request_next_id + 1
+        asyncio.ensure_future(self.send_message_to_server(message))
+        # you should await self.__responses[request_id] which should be a task, 
+        # which you resolve somewhere else
+        while request_id not in self.__responses:
+            await asyncio.sleep(1)
+        response = self.__responses[request_id]
+        del self.__responses[request_id]
+        return response
 
     def __aiter__(self):
-        if self._aiter_inited:
+        if self.__aiter_inited:
             raise RuntimeError('Can`t iterate twice')
-        _aiter_inited = True
+        __aiter_inited = True
         return self
 
     async def __anext__(self) -> ServerMessage:
-        while True:
-            received_bytes = await self.socket.recv(copy=True)
-            text = received_bytes.decode('utf-8')
-
-            if text == 'PING':
-                asyncio.ensure_future(self.__handle_ping())
+        while not PARSE_MESSAGE_OR_SAVE_LOOP_INTERRUPTED:
+            thread_message = await self._recv_message_from_thread()
+            server_message = self.__parse_message_or_save(thread_message)
+            if server_message is None:
+                continue
             else:
-                message = self.__parse_message_or_save(text)
-                if message is None:
-                    continue
-                else:
-                    return message
+                return server_message
 
-    async def send_message(self, message: ServerMessage):
-        await self.socket.send_string(json.dumps(message.toJSON()))
+    async def _run_thread(self):
+        logger.info("Binding to %s ..." % config.ZMQ_CONNECTION_STRING)
+        self.__server_socket = self._zmq_context.socket(zmq.PAIR)
+        self.__server_socket.bind(config.ZMQ_CONNECTION_STRING)
+        await self.__server_socket_recv_loop()
 
-    async def send_request(self, message: ServerMessage) -> object:
-        if message.request_id is not None:
-            raise ValueError('Message can`t have request_id before it is scheduled')
-        request_id = message.request_id = self.request_next_id
-        self.request_next_id = self.request_next_id + 1
-        asyncio.ensure_future(self.send_message(message))
-        while request_id not in self.responses:
-            await asyncio.sleep(1)
-        response = self.responses[request_id]
-        del self.responses[request_id]
-        return response
+    async def _on_message_to_thread(self, message: str):
+        await self.__server_socket.send_string(message)
+
+    async def __server_socket_recv_loop(self):
+        while not SERVER_SOCKET_RECV_LOOP_INTERRUPTED:
+            received_string = await self.__server_socket.recv_string()
+            if received_string == 'PING':
+                asyncio.ensure_future(self.__handle_ping())
+            else:
+                asyncio.ensure_future(self._send_message_from_thread(received_string))
 
     async def __handle_ping(self):
-        await self.socket.send(b'PONG')
+        await self.__server_socket.send_string('PONG')
 
     def __parse_message_or_save(self, text: str) -> Optional[ServerMessage]:
         try:
             message_object = json.loads(text)
             message = ServerMessage.fromJSON(message_object)
             if message.request_id is not None:
-                self.responses[message_object['requestId']] = message.payload
+                self.__responses[message_object['requestId']] = message.payload
                 return None
             return message
         except Exception:

analytics/bin/server

@@ -52,14 +52,14 @@ async def handle_task(task: object):
 
         if not task_type == 'PUSH':
             message = services.server_service.ServerMessage('TASK_RESULT', task_result_payload)
-            await server_service.send_message(message)
+            await server_service.send_message_to_server(message)
 
         res = await analytic_unit_manager.handle_analytic_task(task)
         res['_id'] = task['_id']
 
         if not task_type == 'PUSH':
             message = services.server_service.ServerMessage('TASK_RESULT', res)
-            await server_service.send_message(message)
+            await server_service.send_message_to_server(message)
 
     except Exception as e:
         error_text = traceback.format_exc()
@@ -71,7 +71,7 @@ async def handle_data(task: object):
     if res['status'] == 'SUCCESS' and res['payload'] is not None:
         res['_id'] = task['_id']
         message = services.server_service.ServerMessage('DETECT', res)
-        await server_service.send_message(message)
+        await server_service.send_message_to_server(message)
 
 async def handle_message(message: services.ServerMessage):
     if message.method == 'TASK':