Optimize imports

nemubot/server/abstract.py

@@ -0,0 +1,147 @@
+# -*- coding: utf-8 -*-
+
+# Nemubot is a smart and modulable IM bot.
+# Copyright (C) 2012-2015  Mercier Pierre-Olivier
+#
+# This program 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.
+#
+# This program 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.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import io
+import logging
+import queue
+
+from nemubot.server import _rlist, _wlist, _xlist
+
+# Extends from IOBase in order to be compatible with select function
+class AbstractServer(io.IOBase):
+
+    """An abstract server: handle communication with an IM server"""
+
+    def __init__(self, send_callback=None):
+        """Initialize an abstract server
+
+        Keyword argument:
+        send_callback -- Callback when developper want to send a message
+        """
+
+        if not hasattr(self, "id"):
+            raise Exception("No id defined for this server. Please set one!")
+
+        self.logger = logging.getLogger("nemubot.server." + self.id)
+        self._sending_queue = queue.Queue()
+        if send_callback is not None:
+            self._send_callback = send_callback
+        else:
+            self._send_callback = self._write_select
+
+
+    # Open/close
+
+    def __enter__(self):
+        self.open()
+        return self
+
+
+    def __exit__(self, type, value, traceback):
+        self.close()
+
+
+    def open(self):
+        """Generic open function that register the server un _rlist in case
+        of successful _open"""
+        self.logger.info("Opening connection to %s", self.id)
+        if not hasattr(self, "_open") or self._open():
+            _rlist.append(self)
+            _xlist.append(self)
+            return True
+        return False
+
+
+    def close(self):
+        """Generic close function that register the server un _{r,w,x}list in
+        case of successful _close"""
+        self.logger.info("Closing connection to %s", self.id)
+        if not hasattr(self, "_close") or self._close():
+            if self in _rlist:
+                _rlist.remove(self)
+            if self in _wlist:
+                _wlist.remove(self)
+            if self in _xlist:
+                _xlist.remove(self)
+            return True
+        return False
+
+
+    # Writes
+
+    def write(self, message):
+        """Asynchronymously send a message to the server using send_callback
+
+        Argument:
+        message -- message to send
+        """
+
+        self._send_callback(message)
+
+
+    def write_select(self):
+        """Internal function used by the select function"""
+        try:
+            _wlist.remove(self)
+            while not self._sending_queue.empty():
+                self._write(self._sending_queue.get_nowait())
+                self._sending_queue.task_done()
+
+        except queue.Empty:
+            pass
+
+
+    def _write_select(self, message):
+        """Send a message to the server safely through select
+
+        Argument:
+        message -- message to send
+        """
+
+        self._sending_queue.put(self.format(message))
+        self.logger.debug("Message '%s' appended to Queue", message)
+        if self not in _wlist:
+            _wlist.append(self)
+
+
+    def send_response(self, response):
+        """Send a formated Message class
+
+        Argument:
+        response -- message to send
+        """
+
+        if response is None:
+            return
+
+        elif isinstance(response, list):
+            for r in response:
+                self.send_response(r)
+
+        else:
+            vprnt = self.printer()
+            response.accept(vprnt)
+            self.write(vprnt.pp)
+
+
+    # Exceptions
+
+    def exception(self):
+        """Exception occurs in fd"""
+        self.logger.warning("Unhandle file descriptor exception on server %s",
+                            self.id)