[Add] Add log engine

vnpy/trader/engine.py

@@ -1,11 +1,15 @@
 """
 """
 
+import logging
+from datetime import datetime
+
 from vnpy.event import EventEngine, Event
 
 from .event import EVENT_LOG
 from .object import LogData, SubscribeRequest, OrderRequest, CancelRequest
-
+from .utility import Singleton, get_temp_path
+from .setting import SETTINGS
 
 class MainEngine:
     """
@@ -23,6 +27,8 @@ class MainEngine:
         self.gateways = {}
         self.apps = {}
 
+        self.log_engine = LogEngine(self, self.event_engine)
+
     def write_log(self, msg: str):
         """
         Put log event with specific message.
@@ -31,7 +37,7 @@ class MainEngine:
         event = Event(EVENT_LOG, log)
         self.event_engine.put(event)
 
-    def get_gateway(gateway_name: str):
+    def get_gateway(self, gateway_name: str):
         """
         Return gateway object by name.
         """
@@ -81,3 +87,71 @@ class MainEngine:
             gateway.close()
 
         self.event_engine.stop()
+
+
+class LogEngine:
+    """
+    Process log event and output with logging module.
+    """
+
+    __metaclass__ = Singleton
+
+    def __init__(self, main_engine: MainEngine, event_engine: EventEngine):
+        """"""
+        self.main_engine = main_engine
+        self.event_engine = event_engine
+
+        if not SETTINGS["log.active"]:
+            return
+
+        self.level = SETTINGS["log.level"]
+        self.logger = logging.getLogger("VN Trader")
+        self.formatter = logging.Formatter("%(asctime)s  %(levelname)s: %(message)s")
+        
+        self.add_null_handler()
+
+        if SETTINGS["log.console"]:
+            self.add_console_handler()
+        
+        if SETTINGS["log.file"]:
+            self.add_file_handler()
+
+        self.register_event()
+
+    def add_null_handler(self):
+        """
+        Add null handler for logger.
+        """
+        null_handler = logging.NullHandler()
+        self.logger.addHandler(null_handler)
+    
+    def add_console_handler(self):
+        """
+        Add console output of log.
+        """
+        console_handler = logging.StreamHandler()
+        console_handler.setLevel(self.level)
+        console_handler.setFormatter(self.formatter)
+        self.logger.addHandler(console_handler)
+    
+    def add_file_handler(self):
+        """
+        Add file output of log. 
+        """
+        today_date = datetime.now().strftime("%Y%m%d")
+        filename = f"vt_{today_date}.log"
+        file_path = get_temp_path(filename)
+
+        file_handler = logging.FileHandler(file_path, mode='w', encoding='utf8')
+        file_handler.setLevel(self.level)
+        file_handler.setFormatter(self.formatter)
+        self.logger.StreamHandler(file_handler)
+
+    def register_event(self):
+        """"""
+        self.event_engine.register(EVENT_LOG, self.process_log_event)
+
+    def process_log_event(self, event: Event):
+        """"""
+        log = event.data
+        self.logger.log(log.level, log.msg)

vnpy/trader/utility.py

@@ -0,0 +1,35 @@
+"""
+General utility functions.
+"""
+
+from pathlib import Path
+
+class Singleton(type):
+    """
+    Singleton metaclass, 
+    
+    class A:
+        __metaclass__ = Singleton
+        
+    """
+    _instances = {}
+
+    def __call__(cls, *args, **kwargs):
+        """"""
+        if cls not in cls._instances:
+            cls._instances[cls] = super(VtSingleton, cls).__call__(*args, **kwargs)
+            
+        return cls._instances[cls]
+
+
+def get_temp_path(filename):
+    """
+    Get path for temp file with filename.
+    """
+    home_path = Path.home()
+    temp_path = home_path.joinpath('.vntrader')
+
+    if not temp_path.exists():
+        temp_path.mkdir()
+        
+    return temp_path.joinpath(filename)