rewrite examples/echoserver.py using StreamServer class

examples/echoserver.py

 #! /usr/bin/env python
-
-# Copyright (c) 2007, Linden Research, Inc.
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
-
-"""Simple server that listens on port 6000 and echos back every input to
-the client.  To try out the server, start it up by running this file.
+"""Simple server that listens on port 6000 and echos back every input to the client.
 
 Connect to it with:
   telnet localhost 6000
 
-You terminate your connection by terminating telnet (typically Ctrl-]
-and then 'quit')
-
+Terminate the connection by terminating telnet (typically Ctrl-] and then 'quit').
 """
-import gevent
-from gevent import socket
+from gevent.server import StreamServer
+
 
-def handle_socket(fileobj):
+# this handler will be run for each incoming connection in a dedicated greenlet
+def echo(socket, address):
+    print 'New connection from %s:%s' % address
+    # using a makefile because we want to use readline()
+    fileobj = socket.makefile()
+    fileobj.write('Welcome to the echo server! Type quit to exit.\r\n')
+    fileobj.flush()
     while True:
         line = fileobj.readline()
         if not line:
+            print "client disconnected"
+            break
+        if line.strip().lower() == 'quit':
+            print "client quit"
             break
         fileobj.write(line)
         fileobj.flush()
         print "echoed", repr(line)
-    print "client disconnected"
+
 
 if __name__ == '__main__':
-    print "server socket listening on port 6000"
-    server = socket.socket()
-    server.bind(('0.0.0.0', 6000))
-    server.listen(5)
-    while True:
-        try:
-            new_sock, address = server.accept()
-        except KeyboardInterrupt:
-            break
-        # handle every new connection with a new coroutine
-        gevent.spawn(handle_socket, new_sock.makefile())
+    # to make the server use SSL, pass certfile and keyfile arguments to the constructor
+    server = StreamServer(('0.0.0.0', 6000), echo)
+    # to start the server asynchronously, use its start() method;
+    # we use blocking serve_forever() here because we have no other jobs
+    print 'Starting echo server on port 6000'
+    server.serve_forever()